15,152 results on '"PROTON magnetic resonance spectroscopy"'
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2. Deconvolution and Analysis of the 1H NMR Spectra of Crude Reaction Mixtures
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Venetos, Maxwell C, Elkin, Masha, Delaney, Connor, Hartwig, John F, and Persson, Kristin A
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Analytical Chemistry ,Organic Chemistry ,Chemical Sciences ,Proton Magnetic Resonance Spectroscopy ,Monte Carlo Method ,Markov Chains ,Density Functional Theory ,Medicinal and Biomolecular Chemistry ,Theoretical and Computational Chemistry ,Computation Theory and Mathematics ,Medicinal & Biomolecular Chemistry ,Medicinal and biomolecular chemistry ,Theoretical and computational chemistry - Abstract
Nuclear magnetic resonance (NMR) spectroscopy is an important analytical technique in synthetic organic chemistry, but its integration into high-throughput experimentation workflows has been limited by the necessity of manually analyzing the NMR spectra of new chemical entities. Current efforts to automate the analysis of NMR spectra rely on comparisons to databases of reported spectra for known compounds and, therefore, are incompatible with the exploration of new chemical space. By reframing the NMR spectrum of a reaction mixture as a joint probability distribution, we have used Hamiltonian Monte Carlo Markov Chain and density functional theory to fit the predicted NMR spectra to those of crude reaction mixtures. This approach enables the deconvolution and analysis of the spectra of mixtures of compounds without relying on reported spectra. The utility of our approach to analyze crude reaction mixtures is demonstrated with the experimental spectra of reactions that generate a mixture of isomers, such as Wittig olefination and C-H functionalization reactions. The correct identification of compounds in a reaction mixture and their relative concentrations is achieved with a mean absolute error as low as 1%.
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- 2024
3. Diffuse white matter pathology in multiple sclerosis during treatment with dimethyl fumarate—An observational study of changes in normal-appearing white matter using proton magnetic resonance spectroscopy.
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Tisell, Anders, Söderberg, Kristina, Link, Yumin, Lundberg, Peter, and Mellergård, Johan
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PROTON magnetic resonance spectroscopy , *DEMYELINATION , *DIMETHYL fumarate , *WHITE matter (Nerve tissue) , *DISEASE duration , *INTERFERON beta 1b , *NATALIZUMAB - Abstract
Background: Multiple sclerosis (MS) is an inflammatory demyelinating disease with neurodegenerative features causing risk for neurologic irreversible disability over time. Examination of normal-appearing white matter (NAWM) changes in MS by proton magnetic resonance spectroscopy (1H-MRS), may detect diffuse white matter pathology that is associated with neurodegeneration. Methods: In this observational study of in total twenty-six patients with MS, starting treatment with dimethyl fumarate (DMF), we measured the absolute concentration of metabolites in periventricular NAWM using 1H-MRS at baseline and after one and three years of treatment. Metabolite concentrations were analyzed both cross-sectionally, in relation to 10 controls and longitudinally in relation to disease activity. Results: Patients with MS had higher concentrations of myo-inositol (mIns) in NAWM at baseline compared with controls (mean 5.98 ± 1.37 (SD) and 4.32 ± 1.16 (SD), p<0.01, independent samples t-test). The disease duration was inversely correlated with concentrations of total N-acetylaspartate and N-acetylaspartylglutamate (tNA) (r = -0.62, p<0.01) in NAWM as well as positively to the ratio of mIns and tNA (r = 0.51, p = 0.03). Metabolite concentrations during one-year (n = 19) and three-years (n = 11) follow-up were generally stable. The dropouts were caused by treatment switch after one year, mainly due to new MRI activity. Cross-sectional analyses showed that there was an inverse correlation between concentrations of tNA and mIns at both baseline and at 1 and 3-years follow-up (r = -0.44 to -0.65, p = 0.04 to 0.004). Metabolite concentrations were stable during 1-year follow-up independently of disease activity. Conclusions: Higher concentrations of the astrogliosis marker mIns in MS compared to controls, the inverse relation between MS disease duration and the neuroaxonal integrity marker tNA, as well as the consistent inverse relation between these two metabolites during follow-up, showed that non-lesional white matter pathology is present in this cohort of MS patients in early disease stages. However, metabolite concentrations during follow-up were generally stable and did not reflect differences in disease activity among patients. [ABSTRACT FROM AUTHOR]
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- 2024
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4. Cardiac Metabolic Stress During Ischemia and Reperfusion in Patients Undergoing Coronary Artery Bypass Surgery Using Either Calafiore or Modified Del Nido Cardioplegic Solutions.
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Massa, Abd Alhade, Izzat, Ahmad Walid, Saadoun, Rakan, Izzat, Mohammad Bashar, and Mazur, Piotr
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CORONARY artery surgery , *CORONARY artery bypass , *ARTIFICIAL blood circulation , *GLUTAMIC acid , *TROPONIN I , *MYOCARDIAL reperfusion , *PROTON magnetic resonance spectroscopy - Abstract
Objective: Calafiore and modified del Nido cardioplegic solutions are currently being used during coronary artery bypass surgery. This study aims to compare myocardial ischemic stress associated with both solutions by studying the changes in cardiac metabolites during cardioplegic ischemic arrest and early reperfusion. Methods: Biopsy specimens were taken from the left ventricles of 20 patients undergoing routine coronary artery bypass grafting using Calafiore or modified del Nido cardioplegic solutions. Biopsies were taken immediately after the beginning of extracorporeal circulation (basal biopsy), 30 min after application of the aortic cross‐clamp (ischemic biopsy), and 20 min following the removal of aortic cross‐clamp (reperfusion biopsy) and were analyzed for their amino acid and lactic acid contents using amino acid analyzer and appropriate kits. Peripheral blood samples were also collected for the determination of blood concentrations of cardiac proteins (CK‐MB and troponin I) using an immunofluorescence scanner. Results: Both CK‐MB and troponin I increased significantly 12 h postoperatively and were associated with an increase in myocardial lactic acid, but there were no significant differences in markers of myocardial injury between the two groups. Comparison of amino acid concentrations between the two groups according to sampling time showed that glutamic acid concentrations were significantly lower in the Calafiore cardioplegia group compared to the del Nido cardioplegia group, but there were no other significant differences in markers of metabolic stress (taurine and alanine/glutamate ratio) between the two groups. Moreover, there were no significant differences in changes in amino acid concentrations regardless of the type of cardioplegic solution used. Conclusions: Cardioplegic ischemic arrest and early reperfusion are associated with a rise in myocardial metabolic stress. Both Calafiore and modified del Nido cardioplegic solutions are effective in attenuating myocardial substrate derangements and confer equal myocardial protection during routine coronary artery bypass surgery. Trial Registration: ClinicalTrials.gov identifier: NCT06287372 [ABSTRACT FROM AUTHOR]
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- 2024
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5. Cycling of labile and recalcitrant carboxyl-rich alicyclic molecules and carbohydrates in Baffin Bay.
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McKee, Kayla, Abdulla, Hussain, O'Reilly, Lauren, and Walker, Brett D.
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ORGANIC compound content of seawater ,PROTON magnetic resonance spectroscopy ,NUCLEAR magnetic resonance ,SOLID phase extraction ,CHEMICAL structure ,NUCLEAR magnetic resonance spectroscopy - Abstract
Marine dissolved organic matter (DOM) is an important, actively cycling carbon reservoir (662 GtC). However, the chemical structure and cycling of DOM within rapidly warming, polar environments remains largely unconstrained. Previous studies have shown rapid surface cycling of carbohydrates as biologically-labile DOM (LDOM). Conversely, carboxyl-rich alicyclic molecules (CRAM) are often used as examples of biologically-recalcitrant DOM (RDOM). Traditional DOM isolation methods (e.g., ultrafiltration (10–30% of DOM) and solid-phase extraction (40–60% of DOM) induce chemical-, size- and compositional-bias – complicating inferences to total DOM cycling. Here, we use a total DOM proton (
1 H) nuclear magnetic resonance (NMR) spectroscopy method to show carbohydrates and CRAM have high concentrations in the surface ocean and low concentrations at depth in Baffin Bay. Between 21–43% of surface CRAM is removed at depth. These results suggest both CRAM and carbohydrates are major LDOM constituents – contradicting the existing CRAM cycling paradigm and further constraining the long-term persistence of deep ocean DOM. A study using total dissolved organic matter (DOM) proton nuclear magnetic resonance spectroscopy found rapid removal of surface-derived carbohydrates and carboxyl-rich alicyclic molecules at depth, challenging our notions of deep ocean DOM storage. [ABSTRACT FROM AUTHOR]- Published
- 2024
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6. Validity and specificity of BOLD effects and their correction in ¹H-fMRS.
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Just, Nathalie
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PROTON magnetic resonance spectroscopy ,PROTON magnetic resonance ,NUCLEAR magnetic resonance spectroscopy ,SOMATOSENSORY cortex ,OXYGEN in the blood - Abstract
Purpose: This study aimed to characterize blood oxygen level-dependent (BOLD) effects in proton magnetic resonance (1H-MR) spectra obtained during optogenetic activation of the rat forelimb cortex to correct and estimate the accurate changes in metabolite concentration. Methods: For a more comprehensive understanding of BOLD effects detected with functional magnetic resonance spectroscopy (fMRS) and to optimize the correction method, a 1Hz line-narrowing effect was simulated. Then, proton functional magnetic resonance spectroscopy (1H-fMRS) data acquired using stimulated echo acquisition mode (STEAM) at 9.4T in rats (n = 8) upon optogenetic stimulation of the primary somatosensory cortex were utilized. The data were analyzed using MATLAB routines and LCModel. Uncorrected and corrected 1H-MR spectra from the simulated and in vivo data were quantified and compared. BOLD-corrected difference spectra were also calculated and analyzed. Additionally, the effects of stimulated and non-stimulated water on the quantification of metabolite concentration swere investigated. Results: Significant mean increases in water and N-acetylaspartate (NAA) peak heights (+1.1% and +4.5%, respectively) were found to be accompanied by decreased linewidths (-0.5Hz and -2.8%) upon optogenetic stimulation. These estimates were used for further defining an accurate line-broadening (lb) factor. The usage of a non-data-driven lb introduced false-positive errors in the metabolite concentration change estimates, thereby altering the specificity of the findings. The water andmetabolite BOLD contributions were separated using different water scalings within LCModel. Conclusion: The linewidth-matching procedure using a precise lb factor remains the most effective approach for accurately quantifying small (±0.3 µmol/g) metabolic changes in 1H-fMRS studies. A simple and preliminary compartmentation of BOLD effects was proposed, but it will require validation. [ABSTRACT FROM AUTHOR]
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- 2024
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7. Dose-dependent effects of transcranial photobiomodulation on brain temperature in patients with major depressive disorder: a spectroscopy study.
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Weerasekera, Akila, Coelho, David Richer Araujo, Ratai, Eva-Maria, Collins, Katherine Anne, Puerto, Aura Maria Hurtado, De Taboada, Luis, Gersten, Maia Beth, Clancy, Julie A, Hoptman, Matthew J, Irvin, Molly Kennedy, Sparpana, Allison Mary, Sullivan, Elizabeth F, Song, Xiaotong, Adib, Arwa, Cassano, Paolo, and Iosifescu, Dan Vlad
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PROTON magnetic resonance spectroscopy , *MAGNETIC resonance imaging , *MENTAL depression , *NEAR infrared radiation , *TEMPERATURE effect - Abstract
This study aimed to evaluate the dose-dependent brain temperature effects of transcranial photobiomodulation (t-PBM). Thirty adult subjects with major depressive disorder were randomized to three t-PBM sessions with different doses (low: 50 mW/cm2, medium: 300 mW/cm2, high: 850 mW/cm2) and a sham treatment. The low and medium doses were administered in continuous wave mode, while the high dose was administered in pulsed wave mode. A 3T MRI scanner was used to perform proton magnetic resonance spectroscopy (1H-MRS). A voxel with a volume of 30 × 30 × 15 mm3 was placed on the left prefrontal region. Brain temperature (°C) was derived by analyzing 1H-MRS spectrum chemical shift differences between the water (~ 4.7 ppm) and N-acetyl aspartate (NAA) (~ 2.01 ppm) peaks. After quality control of the data, the following group numbers were available for both pre- and post-temperature estimations: sham (n = 10), low (n = 11), medium (n = 10), and high (n = 8). We did not detect significant temperature differences for any t-PBM-active or sham groups post-irradiation (p-value range = 0.105 and 0.781). We also tested for potential differences in the pre-post variability of brain temperature in each group. As for t-PBM active groups, the lowest fluctuation (variance) was observed for the medium dose (σ2 = 0.29), followed by the low dose (σ2 = 0.47), and the highest fluctuation was for the high dose (σ2 = 0.67). t-PBM sham condition showed the overall lowest fluctuation (σ2 = 0.11). Our 1H-MRS thermometry results showed no significant brain temperature elevations during t-PBM administration. [ABSTRACT FROM AUTHOR]
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- 2024
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8. SYNTHESIS, CHARACTERIZATION, AND STUDY OF THE CRYSTALLINE PROPERTIES OF ASTERISM COMPOUNDS.
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Ibrahim, Dardaa A. and Salih, Hanaa K.
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PROTON magnetic resonance spectroscopy , *NUCLEAR magnetic resonance spectroscopy , *LIQUID crystal states , *ESTERS , *POLARIZING microscopes , *BENZENE derivatives - Abstract
This study involves the synthesis of asterism compounds (D1-D6) through the reaction of 1 mole of benzene 1,3,5-triol with 3 moles of prepared pentacyclic ring ester derivatives, dissolved in absolute ethanol. The validity of the compound structures was confirmed using physical and spectroscopic methods such as infrared spectroscopy, and proton nuclear magnetic resonance spectroscopy. Additionally, melting points and purity were determined, and reaction progress was monitored by Thin-Layer Chromatography (TLC). The liquid crystal phases of certain prepared compounds were examined using a polarizing optical microscope (POM). [ABSTRACT FROM AUTHOR]
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- 2024
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9. Neuropathic phenotypes of type 1 diabetes are related to different signatures of magnetic resonance spectroscopy-assessed brain metabolites.
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Hansen, Tine M., Croosu, Suganthiya S., Røikjer, Johan, Mørch, Carsten D., Ejskjaer, Niels, and Frøkjær, Jens B.
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TYPE 1 diabetes , *PROTON magnetic resonance spectroscopy , *PERIPHERAL nervous system , *NUCLEAR magnetic resonance spectroscopy , *DIABETIC neuropathies - Abstract
• Brain alterations have been described in type 1 diabetes and diabetic neuropathy. • Metabolic profiles of neuropathic phenotypes using relevant brain regions were explored. • Specific metabolic brain profiles were linked to phenotypes of diabetes, neuropathy, and neuropathic pain. • Metabolic brain profiles could be relevant for detailed understanding of central neuropathy. The study aimed to investigate brain metabolites in type 1 diabetes and the associations with disease characteristics. We explored the metabolic profiles predicting different neuropathic phenotypes using multiple linear regression analyses. We compared brain metabolites in 55 adults with type 1 diabetes (including painful diabetic peripheral neuropathy (DPN), painless DPN, without DPN) with 20 healthy controls. Proton magnetic resonance spectroscopy measurements (N-acetylaspartate (NAA), glutamate (glu), myo-inositol (mI), and glycerophosphocholine (GPC) were obtained in ratios to creatine (cre)) from the parietal region, anterior cingulate cortex and thalamus. The overall diabetes group revealed decreased parietal NAA/cre compared to healthy controls (1.41 ± 0.12 vs. 1.55 ± 0.13,p < 0.001) and increased mI/cre (parietal: 0.62 ± 0.08 vs. 0.57 ± 0.07,p = 0.025, cingulate: 0.65 ± 0.08 vs. 0.60 ± 0.08,p = 0.033). Reduced NAA/cre was associated with more severe DPN (all p ≤ 0.04) whereas increased mI/cre was associated with higher hemoglobin A 1c (HbA 1c) (p = 0.02). Diabetes was predicted from decreased parietal NAA/cre, increased parietal ml/cre, and decreased thalamic glu/cre. DPN was predicted from decreased parietal NAA/cre and increased GPC/cre. Painful DPN was predicted from increased parietal GPC/cre and thalamic glu/cre. Specific metabolic brain profiles were linked to the different phenotypes of diabetes, DPN and painful DPN. Assessment of metabolic profiles could be relevant for detailed understanding of central neuropathy in diabetes. [ABSTRACT FROM AUTHOR]
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- 2024
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10. Diffusion‐weighted MR spectroscopy of the prostate.
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Stamatelatou, Angeliki, Rizzo, Rudy, Simsek, Kadir, van Asten, Jack J A, Heerschap, Arend, Scheenen, Tom, and Kreis, Roland
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PROTON magnetic resonance spectroscopy ,PROSTATE ,SPECTROMETRY ,STROMAL cells ,DIFFUSION coefficients ,PROTEIN binding - Abstract
Purpose: Prostate tissue has a complex microstructure, mainly composed of epithelial and stromal cells, and of extracellular (acinar‐luminal) spaces. Diffusion‐weighted MR spectroscopy (DW‐MRS) is ideally suited to explore complex microstructure in vivo with metabolites selectively distributed in different subspaces. To date, this technique has been applied to brain and muscle. This study presents the development and pioneering utilization of 1H‐DW‐MRS in the prostate, accompanied by in vitro studies to support interpretations of in vivo findings. Methods: Nine healthy volunteers underwent a prostate MR examination (mean age, 56 years; range, 31–66). Metabolic complexation was studied in vitro using solutions with major compounds found in prostatic fluid of the lumen. DW‐MRS was performed at 3 T with a non–water‐suppressed single‐voxel sequence with metabolite‐cycling to concurrently measure metabolite and water signals. The water signal was used in postprocessing as a reference in a motion‐compensation scheme. The spectra were fitted simultaneously in the spectral and diffusion‐weighting dimensions. Apparent diffusion coefficients (ADCs) were derived by fitting signal decays that were assumed to be mono‐exponential for metabolites and biexponential for water. Results: DW‐MRS of the prostate revealed relatively low ADCs for Cho and Cr compounds, aligning with their intracellular location and higher ADCs for citrate and spermine supporting their luminal origin. In vitro assessments of the ADCs of citrate and spermine demonstrated their complex formation and protein binding. Tissue concentrations of MRS‐detectable metabolites were as expected for the voxel location. Conclusions: This work successfully demonstrates the feasibility of 1H‐DW‐MRS of the prostate and its potential for providing valuable microstructural information. [ABSTRACT FROM AUTHOR]
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- 2024
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11. 1H-MRS reveals abnormal energy metabolism and excitatory-inhibitory imbalance in a chronic migraine-like state induced by nitroglycerin in mice.
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Gao, Jinggui, Wang, Da, Zhu, Chenlu, Wang, Jian, Wang, Tianxiao, Xu, Yunhao, Ren, Xiao, Zhang, Kaibo, Peng, Cheng, Guan, Jisong, and Wang, Yonggang
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BIOLOGICAL models , *SOMATOSENSORY evoked potentials , *RESEARCH funding , *NEURAL pathways , *NITROGLYCERIN , *HYPOTHALAMUS , *TRIGEMINAL nerve , *CELLULAR signal transduction , *NOCICEPTIVE pain , *ENERGY metabolism , *MICE , *THALAMUS , *METABOLITES , *ANIMAL experimentation , *RESEARCH , *HIPPOCAMPUS (Brain) , *MIGRAINE , *NEUROTRANSMITTERS , *PROTON magnetic resonance spectroscopy , *GABA , *CHEMICAL inhibitors ,BRAIN metabolism - Abstract
Background: Chronic migraine is closely related to the dysregulation of neurochemical substances in the brain, with metabolic imbalance being one of the proposed causes of chronic migraine. This study aims to evaluate the metabolic changes between energy metabolism and excitatory and inhibitory neurotransmitters in key brain regions of mice with chronic migraine-like state and to uncover the dysfunctional pathways of migraine. Methods: A chronic migraine-like state mouse model was established by repeated administration of nitroglycerin (NTG). We used von Frey filaments to assess the mechanical thresholds of the hind paw and periorbital in wild-type and familial hemiplegic migraine type 2 mice. After the experiments, tissue was collected from five brain regions: the somatosensory cortex (SSP), hippocampus, thalamus (TH), hypothalamus, and the spinal trigeminal nucleus caudalis (TNC). Proton magnetic resonance spectroscopy (1H-MRS) was employed to study the changes in brain metabolites associated with migraine, aiming to explore the mechanisms underlying metabolic imbalance in chronic migraine-like state. Results: In NTG-induced chronic migraine-like state model, we observed a significant reduction in energy metabolism during central sensitization, an increase in excitatory neurotransmitters such as glutamate, and a tendency for inhibitory neurotransmitters like GABA to decrease. The TNC and thalamus were the most affected regions. Furthermore, the consistency of N-acetylaspartate levels highlighted the importance of the TNC-TH-SSP pathway in the ascending nociceptive transmission of migraine. Conclusion: Abnormal energy metabolism and neurotransmitter imbalance in the brain region of NTG-induced chronic migraine-like state model are crucial mechanisms contributing to the chronicity of migraine. [ABSTRACT FROM AUTHOR]
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- 2024
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12. Understanding Proton Magnetic Resonance Spectroscopy Neurochemical Changes Using Alzheimer's Disease Biofluid, PET, Postmortem Pathology Biomarkers, and APOE Genotype.
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Kara, Firat and Kantarci, Kejal
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PROTON magnetic resonance spectroscopy , *NUCLEAR magnetic resonance spectroscopy , *ALZHEIMER'S disease , *POSITRON emission tomography , *APOLIPOPROTEIN E - Abstract
In vivo proton (1H) magnetic resonance spectroscopy (MRS) is a powerful non-invasive method that can measure Alzheimer's disease (AD)-related neuropathological alterations at the molecular level. AD biomarkers include amyloid-beta (Aβ) plaques and hyperphosphorylated tau neurofibrillary tangles. These biomarkers can be detected via postmortem analysis but also in living individuals through positron emission tomography (PET) or biofluid biomarkers of Aβ and tau. This review offers an overview of biochemical abnormalities detected by 1H MRS within the biologically defined AD spectrum. It includes a summary of earlier studies that explored the association of 1H MRS metabolites with biofluid, PET, and postmortem AD biomarkers and examined how apolipoprotein e4 allele carrier status influences brain biochemistry. Studying these associations is crucial for understanding how AD pathology affects brain homeostasis throughout the AD continuum and may eventually facilitate the development of potential novel therapeutic approaches. [ABSTRACT FROM AUTHOR]
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- 2024
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13. Production and characterization of biodiesel fuel produced from third-generation feedstock.
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Verma, Suraj, Sahu, Deepak, and Almutairi, Bader O.
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FATTY acid methyl esters ,ETHYL esters ,NUCLEAR magnetic resonance spectroscopy ,ALTERNATIVE fuels ,PROTON magnetic resonance spectroscopy ,BIODIESEL fuels ,METHYL formate - Abstract
Biodiesel is an eco-friendly, renewable alternative fuel, and it can be obtained from soybean oil, vegetable oils, animal fat, or microalgae. This study presents a comprehensive investigation into the production and characterization of microalgae biodiesel utilizing multiple analytical techniques, including CHNSO analysis, Fourier-transform infrared spectroscopy (FTIR), gas chromatography--mass spectrometry (GC--MS), and proton nuclear magnetic resonance spectroscopy (¹H NMR). The CHNSO analysis revealed the elemental composition of biodiesel blends, highlighting the effects of TiO
2 nanoparticle concentrations on carbon, nitrogen, sulfur, and oxygen content. With increasing TiO2 concentration, a steady increase in the carbon content and a gradual decrease in the nitrogen content were observed. According to the CHNSO analysis, the sulfur content of blended biodiesel was found to be lower than that of fossil diesel, with an empirical formula of CH2.26 N0.000584 S0.000993 O0.0517 . FTIR and 1H NMR spectroscopy confirmed the synthesis of biodiesel. Fouriertransform infrared resonance confirmed the presence of ester groups at 1732 cm-1 , and a prominent peak at 1,455 cm-1 indicated a higher carbon content in the blended biodiesel. GC--MS analysis identified compounds of fatty acid methyl esters (FAMEs) and hydrocarbons. The major components of FAMEs were 9-octadecenoic acid methyl ester (C19H36O2), linoleic acid ethyl ester (C20 H36 O2 ), and hexadecanoic acid methyl ester (C17 H34 O2 ), with compositions 20.65%, 9.67%, and 6.26%, respectively. The presence of methyl ester in the blended fuel suggests its potential as an alternative fuel source. [ABSTRACT FROM AUTHOR]- Published
- 2024
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14. The Neuroprotective and Anxiolytic Effects of Magnesium Sulfate on Retinal Dopaminergic Neurons in 6-OHDA-Induced Parkinsonian Rats: A Pilot Study.
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Huang, Leyi, Lin, Renxi, Zhang, Chunying, Zheng, Shaoqing, Wang, Yiyang, Wu, Zeyu, Chen, Sihao, Shen, Yihan, Zhang, Guoheng, Qi, Yuanlin, and Lin, Ling
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VISION , *MAGNESIUM sulfate , *PARKINSON'S disease , *DOPAMINERGIC neurons , *MAGNESIUM ions , *PROTON magnetic resonance spectroscopy - Abstract
This study investigates the protective effects of magnesium sulfate on dopamine neurons in the retinas of rats with 6-hydroxydopamine (6-OHDA)-induced Parkinson's disease (PD). Rapidly progressing cognitive decline often precedes or coincides with the motor symptoms associated with PD. PD patients also frequently exhibit visual function abnormalities. However, the specific mechanisms underlying visual dysfunction in PD patients are not yet fully understood. Therefore, this study aims to investigate whether magnesium homeostasis affects dopaminergic neurons in the retina of PD rats. Thirty-six rats were divided into four groups: (1) control, (2) control with magnesium sulfate (control/MgSO4), (3) Parkinson's disease (PD), and (4) Parkinson's disease with magnesium sulfate (PD/MgSO4). The apomorphine-induced (APO) rotation test assessed the success of the PD models. The open-field experiment measured the rats' anxiety levels. Tyrosine hydroxylase (TH) and glutamate levels, indicators of dopamine neuron survival, were detected using immunofluorescence staining. Protein levels of solute carrier family 41 A1 (SCL41A1), magnesium transporter 1 (MagT1), and cyclin M2 (CNNM2) in the retina were analyzed using Western blot. Results showed that, compared to the PD group, rats in the PD/MgSO4 group had improved psychological states and motor performance at two and four weeks post-surgery. The PD/MgSO4 group also exhibited significantly higher TH fluorescence intensity in the left retinas and lower glutamate fluorescence intensity than the PD group. Additional experiments indicated that the protein levels of SLC41A1, MagT1, and CNNM2 were generally higher in the retinas of the PD/MgSO4 group, along with an increase in retinal magnesium ion content. This suggests that magnesium sulfate may reduce glutamate levels and protect dopamine neurons in the retina. Thus, magnesium sulfate might have therapeutic potential for visual functional impairments in PD patients. [ABSTRACT FROM AUTHOR]
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- 2024
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15. Changes in the medial prefrontal cortex metabolites after 6 months of medication therapy for patients with bipolar disorder: A 1H‐MRS study.
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Li, Haijin, Gao, Ju, Song, Huihui, Yang, Xuna, Li, Cai, Zhang, Yue, Wang, Jiahui, Liu, Yitong, Wang, Dong, and Li, Hong
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PROTON magnetic resonance spectroscopy , *PREFRONTAL cortex , *BIPOLAR disorder , *PATIENTS' attitudes , *GLUTAMINE - Abstract
Aims: The study aimed to assess brain metabolite differences in the medial prefrontal cortex (mPFC) between acute and euthymic episodes of bipolar disorder (BD) with both mania and depression over a 6‐month medication treatment period. Methods: We utilized 1H‐MRS technology to assess the metabolite levels in 53 individuals with BD (32 in depressive phase, 21 in manic phase) and 34 healthy controls (HCs) at baseline. After 6 months of medication treatment, 40 subjects underwent a follow‐up scan in euthymic state. Metabolite levels, including N‐acetyl aspartate (NAA), glutamate (Glu), and Glutamine (Gln), were measured in the mPFC. Results: Patients experiencing depressive and manic episodes exhibited a notable reduction in NAA/Cr + PCr ratios at baseline compared to healthy controls (p = 0.004; p = 0.006) in baseline, compared with HCs. Over the 6‐month follow‐up period, the manic group displayed a significant decrease in Gln/Cr + PCr compared to the initial acute phase (p = 0.03). No significant alterations were found in depressed group between baseline and follow‐up. Conclusion: This study suggests that NAA/Cr + PCr ratios and Gln/Cr + PCr ratios in the mPFC may be associated with manic and depressive episodes, implicating that Gln and NAA might be useful biomarkers for distinguishing mood phases in BD and elucidating its mechanisms. [ABSTRACT FROM AUTHOR]
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- 2024
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16. Pro-atherogenic medical conditions are associated with widespread regional brain metabolite abnormalities in those with alcohol use disorder.
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Durazzo, Timothy C, Kraybill, Eric P, Stephens, Lauren H, May, April C, and Meyerhoff, Dieter J
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RESEARCH funding , *CELL membranes , *BRAIN , *DESCRIPTIVE statistics , *METABOLITES , *GRAY matter (Nerve tissue) , *CREATINE , *WHITE matter (Nerve tissue) , *ALCOHOLISM , *COMPARATIVE studies , *COMORBIDITY , *PROTON magnetic resonance spectroscopy ,BRAIN metabolism - Abstract
Aims Widespread brain metabolite abnormalities in those with alcohol use disorder (AUD) were reported in numerous studies, but the effects of the pro-atherogenic conditions of hypertension, type 2 diabetes mellitus, hepatitis C seropositivity, and hyperlipidemia on metabolite levels were not considered. These conditions were associated with brain metabolite abnormalities in those without AUD. We predicted treatment-seeking individuals with AUD and pro-atherogenic conditions (Atherogenic+) demonstrate lower regional metabolite markers of neuronal viability [N-acetylaspartate (NAA)] and cell membrane turnover/synthesis [choline-containing compounds (Cho)], compared with those with AUD without pro-atherogenic conditions (Atherogenic−) and healthy controls (CON). Methods Atherogenic+ (n = 59) and Atherogenic− (n = 51) and CON (n = 49) completed a 1.5 T proton magnetic resonance spectroscopic imaging study. Groups were compared on NAA, Cho, total creatine, and myoinositol in cortical gray matter (GM), white matter (WM), and select subcortical regions. Results Atherogenic+ had lower frontal GM and temporal WM NAA than CON. Atherogenic+ showed lower parietal GM, frontal, parietal and occipital WM and lenticular nuclei NAA level than Atherogenic− and CON. Atherogenic− showed lower frontal GM and WM NAA than CON. Atherogenic+ had lower Cho level than CON in the frontal GM, parietal WM, and thalamus. Atherogenic+ showed lower frontal WM and cerebellar vermis Cho than Atherogenic− and CON. Conclusions Findings suggest proatherogenic conditions in those with AUD were associated with increased compromise of neuronal integrity and cell membrane turnover/synthesis. The greater metabolite abnormalities observed in Atherogenic+ may relate to increased oxidative stress-related compromise of neuronal and glial cell structure and/or impaired arterial vasoreactivity/lumen viability. [ABSTRACT FROM AUTHOR]
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- 2024
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17. Synthesis and Self-assembly of a Simple CO2-responsive Diblock Polymer.
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Zhang, Pengfei, Jing, Xianwu, Zhou, Lang, Liu, Qiang, and Zhang, Yadong
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PROTON magnetic resonance spectroscopy , *NUCLEAR magnetic resonance spectroscopy , *TERTIARY structure , *PROTON transfer reactions , *HYDROGEN atom - Abstract
Methoxypolyethylene glycol 1900 and α-bromoisobutanoyl bromide were utilized for alcoholysis reaction to obtain a macromolecular initiator. Then, a simple amphiphilic diblockpolymer (mPEG-PDMAEMA) based on the initiator and dimethylaminoethyl methacrylate was synthesized through the atomic transfer radical polymerization (ATRP) method. The structures of the initiator and diblock polymer were accurately characterized using infrared spectrum and proton nuclear magnetic resonance spectroscopy (1H NMR). Cryo-transmission electron microscopy revealed the self-assembly of mPEG-PDMAEMA into vesicle-like structures in water. Upon injection of CO2 into the solution, the tertiary amine structure within PDMAEMA underwent protonation, resulting in the mPEG-PDMAEMA adopting a hydrophilic structure. Consequently, the vesicles dissociated and dispersed, forming a network-like structure in water. The protonation phenomenon was confirmed by 1H NMR, as evidenced by the shifting of alkyl hydrogen atoms near nitrogen atoms toward downfield positions. [ABSTRACT FROM AUTHOR]
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- 2024
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18. The association of tobacco smoking and metabolite levels in the anterior cingulate cortex of first-episode psychosis patients: A case-control and 6-month follow-up 1H-MRS study.
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Koster, Merel, van der Pluijm, Marieke, van de Giessen, Elsmarieke, Schrantee, Anouk, van Hooijdonk, Carmen F.M., Selten, Jean-Paul, Booij, Jan, de Haan, Lieuwe, Ziermans, Tim, and Vermeulen, Jentien
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PROTON magnetic resonance spectroscopy , *SMOKING , *CHOLINERGIC receptors , *CINGULATE cortex , *CELL proliferation - Abstract
Tobacco smoking is highly prevalent among patients with psychosis and associated with worse clinical outcomes. Neurometabolites, such as glutamate and choline, are both implicated in psychosis and tobacco smoking. However, the specific associations between smoking and neurometabolites have yet to be investigated in patients with psychosis. The current study examines associations of chronic smoking and neurometabolite levels in the anterior cingulate cortex (ACC) in first-episode psychosis (FEP) patients and controls. Proton magnetic resonance spectroscopy (1H MRS) data of 59 FEP patients and 35 controls were analysed. Associations between smoking status (i.e., smoker yes/no) or cigarettes per day and Glx (glutamate + glutamine, as proxy for glutamate) and total choline (tCh) levels were assessed at baseline in both groups separately. For patients, six months follow-up data were acquired for multi-cross-sectional analysis using linear mixed models. No significant differences in ACC Glx levels were found between smoking (n = 28) and non-smoking (n = 31) FEP patients. Smoking patients showed lower tCh levels compared to non-smoking patients at baseline, although not surving multiple comparisons correction, and in multi-cross-sectional analysis (p FDR = 0.08 and p FDR = 0.044, respectively). Negative associations were observed between cigarettes smoked per day, and ACC Glx (p FDR = 0.02) and tCh levels (p FDR = 0.02) in controls. Differences between patients and controls regarding Glx might be explained by pre-existing disease-related glutamate deficits or alterations at nicotine acetylcholine receptor level, resulting in differences in tobacco-related associations with neurometabolites. Additionally, observed alterations in tCh levels, suggesting reduced cellular proliferation processes, might result from exposure to the neurotoxic effects of smoking. [ABSTRACT FROM AUTHOR]
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- 2024
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19. Greater hepatic lipid saturation is associated with impaired glycaemic regulation in men with metabolic dysfunction‐associated steatotic liver disease but is not altered by 6 weeks of exercise training.
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Willis, Scott A., Malaikah, Sundus, Bawden, Stephen J., Sherry, Aron P., Sargeant, Jack A., Coull, Nicole A., Bradley, Christopher R., Rowlands, Alex, Naim, Iyad, Ennequin, Gaël, Yates, Thomas, Waheed, Ghazala, Gowland, Penny, Stensel, David J., Webb, David R., Davies, Melanie J., Aithal, Guruprasad P., and King, James A.
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PROTON magnetic resonance spectroscopy , *FATTY liver , *EXERCISE therapy , *GLYCEMIC control , *BLOOD sugar , *EXERCISE intensity - Abstract
Aims: To examine the impact of impaired glycaemic regulation (IGR) and exercise training on hepatic lipid composition in men with metabolic dysfunction‐associated steatotic liver disease (MASLD). Materials and Methods: In Part A (cross‐sectional design), 40 men with MASLD (liver proton density fat fraction [PDFF] ≥5.56%) were recruited to one of two groups: (1) normal glycaemic regulation (NGR) group (glycated haemoglobin [HbA1c] < 42 mmol∙mol−1 [<6.0%]; n = 14) or (2) IGR group (HbA1c ≥ 42 mmol∙mol−1 [≥6.0%]; n = 26). In Part B (randomized controlled trial design), participants in the IGR group were randomized to one of two 6‐week interventions: (1) exercise training (EX; 70%–75% maximum heart rate; four sessions/week; n = 13) or (2) non‐exercise control (CON; n = 13). Saturated (SI; primary outcome), unsaturated (UI) and polyunsaturated (PUI) hepatic lipid indices were determined using proton magnetic resonance spectroscopy. Additional secondary outcomes included liver PDFF, HbA1c, fasting plasma glucose (FPG), homeostatic model assessment of insulin resistance (HOMA‐IR), peak oxygen uptake (VO2 peak), and plasma cytokeratin‐18 (CK18) M65, among others. Results: In Part A, hepatic SI was higher and hepatic UI was lower in the IGR versus the NGR group (p = 0.038), and this hepatic lipid profile was associated with higher HbA1c levels, FPG levels, HOMA‐IR and plasma CK18 M65 levels (rs ≥0.320). In Part B, hepatic lipid composition and liver PDFF were unchanged after EX versus CON (p ≥ 0.257), while FPG was reduced and VO2 peak was increased (p ≤ 0.030). ΔVO2 peak was inversely associated with Δhepatic SI (r = −0.433) and positively associated with Δhepatic UI and Δhepatic PUI (r ≥ 0.433). Conclusions: Impaired glycaemic regulation in MASLD is characterized by greater hepatic lipid saturation; however, this composition is not altered by 6 weeks of moderate‐intensity exercise training. [ABSTRACT FROM AUTHOR]
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- 2024
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20. Gender-related alterations of serum trace elements and neurometabolism in the anterior cingulate cortex of patients with major depressive disorder.
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Zhong, Qilin, Lai, Shunkai, He, Jiali, Zhong, Shuming, Song, Xiaodong, Wang, Ying, Zhang, Yiliang, Chen, Guanmao, Yan, Shuya, and Jia, Yanbin
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MENTAL depression , *CINGULATE cortex , *TRACE elements , *PROTON magnetic resonance spectroscopy , *SEX factors in disease , *SERUM , *METHYL aspartate receptors - Abstract
It is widely known that sex differences have a significant impact on patients with major depressive disorder (MDD). This study aims to evaluate the sex-related connection between serum trace elements and changes in neurometabolism in the anterior cingulate cortex (ACC) of MDD patients. 109 untreated MDD patients and 59 healthy controls underwent proton magnetic resonance spectroscopy (1H-MRS) under resting conditions. We measured metabolic ratios in the ACC from both sides. Additionally, venous blood samples were taken from all participants to detect calcium (Ca), phosphorus, magnesium (Mg), copper (Cu), ceruloplasmin (CER), zinc (Zn), and iron (Fe) levels. We performed association and interaction analyses to explore the connections between the disease and gender. In individuals with MDD, the Cu/Zn ratio increased, while the levels of Mg, CER, Zn and Fe decreased. Male MDD patients had lower Cu levels, while female patients had an increased Cu/Zn ratio. We observed significant gender differences in Cu, CER and the Cu/Zn ratio in MDD. Male patients showed a reduced N -acetyl aspartate (NAA)/phosphocreatine + creatine (PCr + Cr) ratio in the left ACC. The NAA/PCr + Cr ratio decreased in the right ACC in patients with MDD. In the left ACC of male MDD patients, the Cu/Zn ratio was inversely related to the NAA/PCr + Cr ratio, and Fe levels were negatively associated with the GPC + PC/PCr + Cr ratio. Our findings highlight gender-specific changes in Cu homeostasis among male MDD patients. The Cu/Zn ratio and Fe levels in male MDD patients were significantly linked to neurometabolic alterations in the ACC. • Serum levels of Cu and CER decreased in men with MDD, while the Cu/Zn ratio increased in women with MDD. • In males with MDD, a gender-specific decrease in the NAA/PCr + Cr ratio was noted in the left ACC. • The Cu/Zn ratio and Fe levels in male MDD patients are associated with changes in neurometabolism in the ACC. [ABSTRACT FROM AUTHOR]
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- 2024
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21. Alterations in metabolites in the anterior cingulate cortex and thalamus and their associations with pain and empathy in patients with chronic mild pain: a preliminary study.
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Shigemura, Tomonori, Osone, Fumio, Hara, Akira, Miyano, Kanako, Okada, Akihiro, Yokokawa, Tokuzou, and Shirayama, Yukihiko
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PROTON magnetic resonance spectroscopy , *CHRONIC pain , *MCGILL Pain Questionnaire , *CINGULATE cortex , *THALAMUS - Abstract
Proton magnetic resonance spectroscopy (1H-MRS) has shown inconsistent alterations in the brain metabolites of individuals with chronic pain. We used 3T 1H-MRS to investigate the brain metabolites in the anterior cingulate cortex and thalamus of 22 patients with chronic mild pain and no gait disturbance and 22 healthy controls. The chronic-pain group included patients with chronic low back pain and/or osteoarthritis but none suffering from hypersensitivity. There were no significant between group-differences in glutamate, glutamate plus glutamine (Glx), N-acetylaspartate, glycerophosphorylcholine (GPC), glutamine, creatine plus phosphocreatine, or myo-inositol in the anterior cingulate cortex, but the patients showed a significant decrease in GPC, but not other metabolites, in the thalamus compared to the controls. The GPC values in the patients' thalamus were significantly correlated with pain components on the Short-Form McGill Pain Questionnaire (SF-MPQ-2) and affective empathy components on the Questionnaire of Cognitive and Affective Empathy (QCAE). The GPC in the patients' anterior cingulate cortex showed significant correlations with cognitive empathy components on the QCAE. Myo-inositol in the controls' anterior cingulate cortex and Glx in the patients' thalamus each showed significant relationships with peripheral responsivity on the QCAE. These significances were not significant after Bonferroni corrections. These preliminary findings indicate important roles of GPC, myo-inositol, and Glx in the brain of patients with chronic mild pain. [ABSTRACT FROM AUTHOR]
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- 2024
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22. Identification and characterization of phytochemicals in methanolic extract of roots of Datura fastuosa using various techniques.
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Melese, Girma Mengesha, Aychiluhim, Tewodros Brihanu, Yessuf, Abdurrahman Mengesha, and Eshete, Matthewos
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NUCLEAR magnetic resonance spectroscopy , *PLANT extracts , *PROTON magnetic resonance spectroscopy , *CHEMICAL formulas , *CARBON compounds - Abstract
Background: Plant extracts have attracted significant interest among researchers due to their potential bioactivity and crucial contribution to the production of pharmaceutical compounds. In this study, the primary objective was to extract, analyze and characterize the bioactive compounds found in the methanol root extract of Datura fastuosa (D. fastuosa). This was achieved using various analytical techniques such as gas chromatography/mass spectrometry (GC–MS), ultra-violet visible spectrophotometry, Fourier-transform infrared (FT-IR), nuclear magnetic radiation spectrometry (NMR) and DPPH free radical scavenging activity assay. Results: GC–MS analysis of the methanol root crude extract identified 49 compounds. Three compounds were isolated via column chromatography; one was pure, with a sharp melting point and clean IR spectrum, while the other two showed broad melting points and IR interferences. Comprehensive investigation of the pure extract revealed a UV profile with two distinct bands (300–800 nm) and confirmed functional groups (alcohol, alkanes, alkenes, carbonyl, methylene, and methyl) through FT-IR analysis. The 1HNMR (proton nuclear magnetic resonance spectroscopy) signal confirmed the presence of forty-nine non-equivalent protons, 13CNMR (Carbon-13 nuclear magnetic resonance spectroscopy) signal confirmed the presence of 32 non-equivalent carbons and DEPT-135 (distortionless enhancement by polarization transfer-135) signal confirmed the presence of 24 carbons (17 for odd and 7 for even) which are protons containing carbons in the compound. Combining the above mentioned analyses with data obtained from the GC/MS analysis of National Institute of Standards and Technology (NIST) library, the isolated pure compound exhibited a structural similarity to 1-(7-(3-hydroxyphenyl)-1,1,4a,5,6,9,10a,10b-octamethyl-1,2,3,4,4a,4b,6a,7,8,9,10,10a,10b,11,12,12a-hexadecahydrochrysen-2-yl)propan-1-one, with a chemical formula of C35H50O2. Conclusions: The presence of various notable compounds, including phenolics, flavonoids, alkaloids, steroids etc., within the methanol root extract of D. fastuosa signifies its pharmacological potential. The methanol crude extract demonstrated antioxidant potential compared to standard ascorbic acid, exhibiting DPPH scavenging activity. Previous research has demonstrated the bioactivity of some of these compounds, further elucidating the plant's medicinal properties. These findings not only suggest opportunities for developing synthetic drugs but also underscore its direct therapeutic potential in addressing diverse ailments. [ABSTRACT FROM AUTHOR]
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- 2024
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23. Bioactive molecules isolated from Cymbopogon flexuosus and Monarda citriodora essential oils: Chemical profiling, antimycotic potential, and molecular docking studies against green and blue molds of Kinnow.
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Rashmi, Tandon, Ritu, Kalia, Anu, Raju, Baddipadige, and Silakari, Om
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FOURIER transform infrared spectroscopy techniques , *PROTON magnetic resonance spectroscopy , *CHITIN synthase , *MICROSCOPY , *ANTIFUNGAL agents , *THYMOL , *CHITIN - Abstract
Among the most alarming postharvest fungal pathogens affecting the shelf life of citrus fruits are green (Penicillium digitatum) and blue (Penicillium italicum) molds. This in vitro study was aimed to evaluate the essential oils (EOs) of Cymbopogon flexuosus (CF) and Monarda citriodora (MC) and their principal components against these fungal pathogens. The composition of selected EOs was analyzed using Gas Chromatography- Mass Spectrometry (GC-MS) and Gas Chromatography-Flame Ionization Detector (GC-FID). Citral (83.81%) and thymol (62.51%) were identified as major components and were isolated by column chromatography from CF and MC EO respectively followed by characterization using spectral techniques such as Fourier Transform Infrared Spectroscopy (FTIR), Proton Nuclear Magnetic Resonance Spectroscopy (1H-NMR) and Carbon Nuclear Magnetic Resonance Spectroscopy (13C-NMR). Among EOs and their major components, thymol displayed promising potential against both Penicillium species with MIC values of 50 and 80 mg L-1 respectively. Molecular docking studies also confirmed the stable binding interaction of both components, particularly thymol with the active sites of target proteins i.e. 14-α-demethylase and chitin synthase of P. digitatum and P. italicum with the docking scores of -5.07, -5.41 kcal/mol and -5.78, -5.23 kcal/mol respectively. Optical microscopy studies revealed hyphal thinning and fragmentation at frequent sites with contraction of cytoplasmic content indicating incipient plasmolysis. The tested principal components, citral and thymol were predicted to exhibit similar mechanism of action to that of synthetic recommended molecules as revealed by molecular docking. Therefore, these findings provide empirical support to explore thymol as a promising eco-friendly antifungal agent for postharvest application in Kinnow. [ABSTRACT FROM AUTHOR]
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- 2024
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24. The Utility of Multiparametric Magnetic Resonance Imaging in Reducing Diagnostic Uncertainty for Primary Central Nervous System Lymphoma.
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Goel, Aimee, Flintham, Robert, Pohl, Ute, Nagaraju, Santhosh, Meade, Sara, Sanghera, Paul, Benghiat, Helen, Ughratdar, Ismail, Wykes, Victoria, and Sawlani, Vijay
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MAGNETIC resonance imaging , *CENTRAL nervous system , *DIFFUSE large B-cell lymphomas , *PROTON magnetic resonance spectroscopy , *DIFFUSION magnetic resonance imaging - Abstract
A key limitation in treatment initiation in primary central nervous system lymphoma (PCNSL) is the diagnostic delay caused by lack of recognition of a lesion as a possible lymphoma, steroid initiation, and lesion involution, often resulting in an inconclusive biopsy result. We highlight the importance of multiparametric magnetic resonance imaging (MRI), which incorporates diffusion-weighted imaging, dynamic susceptibility contrast-enhanced perfusion-weighted imaging, and proton magnetic resonance spectroscopy in addition to standard MRI sequences in resolving diagnostic uncertainty for PCNSL. At our center, a consecutive series of 10 patients with histology-proven PCNSL (specifically, diffuse large B-cell lymphoma of the central nervous system) underwent multiparametric MRI. We retrospectively analyzed qualitative and semiquantitative parameters and assessed their radiological concordance for this diagnosis. We noted overall low apparent diffusion coefficient on diffusion-weighted imaging (mean minimum apparent diffusion coefficient of 0.74), high percentage signal recovery on perfusion-weighted imaging (mean 170%), a high choline-to-creatine ratio, and a high-grade lipid peak on proton magnetic resonance spectroscopy giving an appearance of twin towers. Of 10 patients, 9 had MRI findings concordant for PCNSL, defined as at least 3 of 4 parameters being consistent for PCNSL. Concordance between these imaging multiparametric modalities could be used as a radiological predictor of PCNSL, reducing diagnostic delays, providing a more accurate biopsy target, and resulting in quicker treatment initiation. [ABSTRACT FROM AUTHOR]
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- 2024
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25. Synthesis and properties of bio-based polyesters from a 2,4-dihydroxyacetophenone derivative.
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Yang, Yingao, Cheng, Zhengzai, Wandji Djouonkep, Lesly Dasilva, and Gauthier, Mario
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PROTON magnetic resonance spectroscopy , *NUCLEAR magnetic resonance spectroscopy , *GEL permeation chromatography , *GLASS transition temperature , *POLYESTERS , *CARBON offsetting - Abstract
A novel diphenyl monomer, dimethyl 2,2'-(((ethane-1,2-diylbis(oxy))bis(4-acetyl-3,1-phenylene))bis(oxy))diacetate (EDPD), was synthesized from methyl 2-(4-acetyl-3-hydroxyphenoxy)acetate (MAHA), a 2,4-dihydroxyacetophenonederivative, and combined with 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol or p-phenylenedimethanolto afford a series of biodegradable polyesters via melt polymerization. The polyesters were characterized by Fourier transform infrared and proton nuclear magnetic resonance spectroscopy, gel permeation chromatography, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The weight-average molecular weight (Mw) of the polyesters varied from 3.2–4.4 × 104 g/mol, the glass transition temperature (Tg) from 52 to 80 °C, and the 5% decomposition temperature (Td,5%) was in the 334–362 °C range. All the samples exhibited high yield strength (53–68 MPa) and elongation at break (230–330%) values, comparable with poly(ethylene terephthalate) (PET), owing to their aromatic character. Degradability testing of the polyesters in soil yielded mass losses reaching up to 7% after 32 weeks. In ecotoxicity testing, earthworms had a survival rate of more than 80% after 14 d of incubation, indicating relatively low toxicity. Overall, the good thermal and mechanical properties, biodegradability and low ecotoxicity of the polyesters make them promising materials for packaging applications, in replacement for PET, thereby promoting carbon neutrality and sustainable development. [ABSTRACT FROM AUTHOR]
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- 2024
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26. Clozapine treatment and astrocyte activity in treatment resistant schizophrenia: A proton magnetic resonance spectroscopy study.
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Torres-Carmona, Edgardo, Nakajima, Shinichiro, Iwata, Yusuke, Ueno, Fumihiko, Stefan, Cristiana, Song, Jianmeng, Abdolizadeh, Ali, Koizumi, Michel Teruki, Kambari, Yasaman, Amaev, Aron, Agarwal, Sri Mahavir, Mar, Wanna, de Luca, Vincenzo, Remington, Gary, Gerretsen, Philip, and Graff-Guerrero, Ariel
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PROTON magnetic resonance spectroscopy , *MINI-Mental State Examination , *CLOZAPINE , *ANTIPSYCHOTIC agents , *SCHIZOPHRENIA - Abstract
Clozapine is the only antipsychotic approved for treating treatment-resistant schizophrenia (TRS), characterized by persistent positive symptoms despite adequate antipsychotic treatment. Unfortunately, clozapine demonstrates clinical efficacy in only ~30–60 % of patients with TRS (clozapine-responders; ClzR+), while the remaining ~40–70 % are left with no pharmacological recourse for improvement (clozapine-resistant; ClzR−). Mechanism(s) underlying clozapine's superior efficacy remain unclear. However, in vitro evidence suggests clozapine may mitigate glutamatergic dysregulations observed in TRS, by modulating astrocyte activity in ClzR+, but not ClzR−. A factor that if proven correct, may help the assessment of treatment response and development of more effective antipsychotics. To explore the presence of clozapine-astrocyte interaction and clinical improvement, we used 3 T proton-magnetic resonance spectroscopy to quantify levels of myo-Inositol, surrogate biomarker of astrocyte activity, in regions related to schizophrenia neurobiology: Dorsal-anterior-cingulate-cortex (dACC), left-dorsolateral-prefrontal-cortex (left-DLPFC), and left-striatum (left-striatum) of 157 participants (ClzR− = 30; ClzR+ = 37; responders = 38; controls = 52). Clozapine treatment was assessed using clozapine to norclozapine plasma levels, 11–12 h after last clozapine dose. Measures for symptom severity (i.e., Positive and Negative Symptoms Scale) and cognition (i.e., Mini-Mental State Examination) were also recorded. Higher levels of myo-Inositol were observed in TRS groups versus responders and controls (dACC (p < 0.001); left-striatum (p = 0.036); left-DLPFC (p = 0.023)). In ClzR+, but not ClzR−, clozapine to norclozapine ratios were positively associated with myo-Inositol levels (dACC (p = 0.004); left-DLPFC (p < 0.001)), and lower positive symptom severity (p < 0.001). Our results support growing in vitro evidence of clozapine-astrocyte interaction in clozapine-responders. Further research may determine the viability of clozapine-astrocyte interactions as an early marker of clozapine response. [ABSTRACT FROM AUTHOR]
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- 2024
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27. Association of insulin resistance with the accumulation of saturated intramyocellular lipid: A comparison with other fat stores.
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Azhar, Mueed, Watson, Laura P. E., De Lucia Rolfe, Emanuella, Ferraro, Michele, Carr, Katherine, Worsley, Jieniean, Boesch, Chris, Hodson, Leanne, Chatterjee, Krishna K., Kemp, Graham J., Savage, David B., and Sleigh, Alison
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INSULIN resistance ,PROTON magnetic resonance spectroscopy ,INSULIN sensitivity ,ECTOPIC tissue ,FAT - Abstract
It has been shown using proton magnetic resonance spectroscopy (1H MRS) that, in a group of females, whole‐body insulin resistance was more closely related to accumulation of saturated intramyocellular lipid (IMCL) than to IMCL concentration alone. This has not been investigated in males. We investigated whether age‐ and body mass index‐matched healthy males differ from the previously reported females in IMCL composition (measured as CH2:CH3) and IMCL concentration (measured as CH3), and in their associations with insulin resistance. We ask whether saturated IMCL accumulation is more strongly associated with insulin resistance than other ectopic and adipose tissue lipid pools and remains a significant predictor when these other pools are taken into account. In this group of males, who had similar overall insulin sensitivity to the females, IMCL was similar between sexes. The males demonstrated similar and even stronger associations of IMCL with insulin resistance, supporting the idea that a marker reflecting the accumulation of saturated IMCL is more strongly associated with whole‐body insulin resistance than IMCL concentration alone. However, this marker ceased to be a significant predictor of whole‐body insulin resistance after consideration of other lipid pools, which implies that this measure carries no more information in practice than the other predictors we found, such as intrahepatic lipid and visceral adipose tissue. As the marker of saturated IMCL accumulation appears to be related to these two predictors and has a much smaller dynamic range, this finding does not rule out a role for it in the pathogenesis of insulin resistance. [ABSTRACT FROM AUTHOR]
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- 2024
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28. Investigating the Link between Intermediate Metabolism, Sexual Dimorphism, and Cardiac Autonomic Dysfunction in Patients with Type 1 Diabetes.
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Insenser, María Rosa, Nattero-Chávez, Lía, Luque-Ramírez, Manuel, Quiñones, Sara de Lope, Quintero-Tobar, Alejandra, Samino, Sara, Amigó, Núria, Dorado Avendaño, Beatriz, Fiers, Tom, and Escobar-Morreale, Héctor F.
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PROTON magnetic resonance spectroscopy ,NUCLEAR magnetic resonance spectroscopy ,AUTONOMIC nervous system ,TYPE 1 diabetes ,SEXUAL dimorphism - Abstract
Sexual dimorphism influences cardiovascular outcomes in type 1 diabetes (T1D), with women facing a higher relative risk of macrovascular events compared to men, especially after menopause. This study hypothesizes that abnormalities in intermediate metabolism may be associated with cardiac autonomic neuropathy (CAN) in T1D. We aim to assess low molecular weight metabolites (LMWM) as markers of CAN in T1D, considering the effects of sexual dimorphism and age. In this cross-sectional study, we included 323 subjects with T1D (147 women and 176 men), with a mean age of 41 ± 13 years. A total of 44 women and 41 men were over 50 years old. CAN was assessed using Ewing's tests, and serum metabolites were analyzed by proton nuclear magnetic resonance spectroscopy (
1 H-NMR). Patients with CAN had lower levels of valine, isoleucine, and threonine, and higher levels of lactate, compared to those without CAN. These differences persisted after adjusting for BMI and estimated glucose disposal rate (eGDR). In a logistic regression model (R² = 0.178, p < 0.001), the main determinants of CAN included isoleucine [Exp(β) = 0.972 (95% CI 0.952; 0.003)], age [Exp(β) = 1.031 (95% CI 1.010; 1.053)], A1c [Exp(β) = 1.361 (95% CI 1.058; 1.752)], and microangiopathy [Exp(β) = 2.560 (95% CI 1.372; 4.778)]. Sex influenced LMWM profiles, with over half of the metabolites differing between men and women. However, no interactions were found between CAN and sex, or between sex, age, and CAN, on metabolomics profiles. Our findings suggest an association between CAN and LMWM levels in T1D. The sexual dimorphism observed in amino acid metabolites was unaffected by the presence of CAN. [ABSTRACT FROM AUTHOR]- Published
- 2024
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29. The Abnormal N-Acetylaspartate to Creatine Ratio of the Right Putamen is Linked to Wakefulness in Patients with Insomnia Disorder
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Huang Q, Shi C, Sonkusare S, Li C, Voon V, and Pan J
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insomnia disorder ,wakefulness ,putamen ,proton magnetic resonance spectroscopy ,naa/cr ratio ,polysomnography ,Psychiatry ,RC435-571 ,Neurophysiology and neuropsychology ,QP351-495 - Abstract
Qiaoting Huang,1 Changzheng Shi,2 Saurabh Sonkusare,3 Congrui Li,1 Valerie Voon,3 Jiyang Pan1 1Department of Psychiatry, The First Affiliated Hospital of Jinan University, Guangzhou, People’s Republic of China; 2Medical Imaging Center, The First Affiliated Hospital of Jinan University, Guangzhou, People’s Republic of China; 3Department of Psychiatry, University of Cambridge, Cambridge, UKCorrespondence: Jiyang Pan, Department of Psychiatry, The First Affiliated Hospital of Jinan University, 613 West Huangpu Avenue, Guangzhou, 510630, People’s Republic of China, Tel +86 20 38688651, Email jiypan@163.com Valerie Voon, Department of Psychiatry, University of Cambridge, Box 189, Level E4, Addenbrooke’s Hospital, Cambridge, CB2 0QQ, UK, Tel +44 1223 765088, Email vv247@cam.ac.ukPurpose: Converging evidence implicates the putamen in sleep-wake regulation. However, its role remains unclear. We hypothesized that metabolic abnormalities in the putamen are linked to insomnia disorder, which has not been previously addressed, and investigated putaminal N-acetylaspartate (NAA), choline (Cho), and creatine (Cr) in patients with insomnia disorder compared to healthy controls.Participants and Methods: In the present study, the concentrations of NAA, Cho, and Cr in the putamen of 23 patients with insomnia disorder and 18 healthy controls were determined using proton magnetic resonance spectroscopy. Sociodemographic, psychometric, and polysomnography data were obtained from all participants.Results: We found that the mean NAA/Cr ratio of the right putamen was significantly greater in the insomnia group compared to the control group and also greater than the left putamen within the insomnia group. The NAA/Cr ratio of the right putamen distinguished insomnia disorder from normal sleep with 78.3% sensitivity and 61.1% specificity. Furthermore, this ratio positively correlated with both objective and subjective insomnia severity and sleep quality.Conclusion: Our findings provide critical evidence for the dysfunctional putaminal metabolism of NAA/Cr in insomnia disorder, suggesting that the abnormal NAA/Cr ratio of the right putamen is linked to wakefulness in patients with insomnia disorder and may serve as a potential biomarker of insomnia disorder.Keywords: insomnia disorder, wakefulness, putamen, proton magnetic resonance spectroscopy, NAA/Cr ratio, polysomnography
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- 2024
30. Glutamate dynamics and BOLD response during OCD symptom provocation in the lateral occipital cortex: A 7 Tesla fMRI-fMRS study.
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de Joode, Niels T., van den Heuvel, Odile A., Koster, Merel, Clarke, William T., van Balkom, Anton J.L.M., Schrantee, Anouk, and Vriend, Chris
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PROTON magnetic resonance spectroscopy , *FUNCTIONAL magnetic resonance imaging , *OBSESSIVE-compulsive disorder , *MENTAL illness , *GLUTAMIC acid - Abstract
Obsessive-compulsive disorder (OCD) is linked with dysfunction in frontal-striatal, fronto-limbic, and visual brain regions. Research using proton magnetic resonance spectroscopy (1H-MRS) suggests that altered neurometabolite levels, like glutamate, may contribute to this dysfunction. However, static neurometabolite levels in OCD patients have shown inconsistent results, likely due to previous studies' limited focus on neurometabolite dynamics. We employ functional MRS (fMRS) and functional magnetic resonance imaging (fMRI) to explore these dynamics and brain activation during OCD symptom provocation. We utilized a combined 7-tesla fMRI-fMRS setup to examine task-related BOLD response and glutamate changes in the lateral occipital cortex (LOC) of 30 OCD participants and 34 matched controls during an OCD-specific symptom provocation task. The study examined main effects and between-group differences in brain activation and glutamate levels during the task. A whole sample task-effects analysis on data meeting predefined quality criteria showed significant glutamate increases (n = 41 (22 OCD, 19 controls), mean change: 3.2 %, z = 3.75, p <.001) and task activation (n = 54 (26 OCD, 28 controls), p <.001) in the LOC during OCD blocks compared to neutral blocks. However, no differences in task-induced glutamate dynamics or activation between groups were found, nor a correlation between glutamate levels and task activation. We were able to measure task-induced increases in glutamate and BOLD levels, emphasizing its feasibility for OCD research. The absence of group differences highlights the need for further exploration to discern to what extent neurometabolite dynamics differ between OCD patients and controls. Once established, future studies can use pre-post intervention fMRS-fMRI to probe the effects of therapies modulating glutamate pathways in OCD. • We used 7 T fMRI-fMRS to assess neurometabolite dynamics and brain activation in OCD. • Revealed significant glutamate increases during symptom provocation without group differences • We found a negative correlation between LOC BOLD response and HAM-A scores in OCD. • We highlighted the potential of fMRS-fMRI for understanding psychiatric disorders. [ABSTRACT FROM AUTHOR]
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- 2024
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31. One-step synthesis of poly(methyl methacrylate-b-ε-caprolactone) block copolymer by simultaneous ATRP and ROP.
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Öztürk, Temel and Demir, Gözde Şenay
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PROTON magnetic resonance spectroscopy , *NUCLEAR magnetic resonance spectroscopy , *METHYL methacrylate , *FOURIER transform infrared spectroscopy , *RING-opening polymerization , *BLOCK copolymers - Abstract
In this study, the simultaneous synthesis of poly(methyl methacrylate-b-ε-caprolactone) block copolymer was fulfilled by atom transfer radical polymerization of methyl methacrylate and ring-opening polymerization of ε-caprolactone. The synthesis of poly(methyl methacrylate-b-ε-caprolactone) block copolymer was carried out by varying the amount of ε-caprolactone monomer, the amount of methyl methacrylate monomer, the amount of 2-(2-chloroethoxy) ethanol initiator, the amount of toluene solvent, and the polymerization time. The effects of these parameters on the reaction conditions were investigated. Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and static light scattering methods were used for the characterization of the synthesized block copolymer. The surface images of the block copolymer were photographed with a scanning electron microscope instrument. In addition, thermal analysis of the synthesized block copolymer was performed using a thermogravimetric analyzer. These analyses prove the formation of the block copolymer structure. The simultaneous synthesis of poly(methyl methacrylate-b-ε-caprolactone) block copolymer was fulfilled by the atom transfer radical polymerization of methyl methacrylate and ring-opening polymerization of ε-caprolactone. The effects of the parameters on the polymerization reaction conditions were investigated. Thermal and spectroscopic measurements prove the formation of the block copolymer structure. [ABSTRACT FROM AUTHOR]
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- 2024
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32. The Rising Importance of Proton Magnetic Resonance Spectroscopy in the Diagnosis of Selected Neurodegenerative Diseases of the Brain.
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Szmyt, Katarzyna, Superson, Maciej, Wilk-Trytko, Klaudia, Szymańska, Katarzyna, Walczak, Kamil, Samojedny, Sylwia, Mika, Wiktoria, Krasnoborska, Julia, and Zarębska, Julia
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PROTON magnetic resonance spectroscopy ,NEURODEGENERATION ,BRAIN diseases ,MAGNETIC resonance imaging ,OLDER people - Abstract
Introduction: Neurodegenerative diseases pose a significant diagnostic challenge due to the increasing elderly population and the rising prevalence of these conditions. State of Knowledge: Differential diagnosis among these diseases is particularly challenging; thus, numerous clinical trials have been conducted to identify markers that could facilitate accurate disease diagnosis. Among various diagnostic approaches, imaging techniques play a crucial role, especially magnetic resonance imaging (MRI), which includes advanced modalities such as proton magnetic resonance spectroscopy (¹H-MRS). ¹H-MRS offers a noninvasive assessment of neurometabolite profiles, providing critical information that aids in precise diagnosis. Conclusions: With ongoing clinical trials, the importance of ¹H-MRS in diagnosing neurodegenerative diseases continues to grow. This paper reviews the results of recent and relevant clinical trials examining changes in ¹H-MRS in the most prevalent neurodegenerative diseases. [ABSTRACT FROM AUTHOR]
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- 2024
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33. Glutamatergic neurotransmission in schizophrenia: A systematic review and quantitative synthesis of proton magnetic resonance spectroscopy studies across schizophrenia spectrum disorders.
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Lopes, Jamie J, Carruthers, Sean P, Meyer, Denny, Dean, Brian, and Rossell, Susan L
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GLUTAMIC acid metabolism , *GLUTAMINE , *BRAIN , *PREFRONTAL cortex , *EXCITATORY amino acid agents , *NEURAL transmission , *SCHIZOPHRENIA , *BASAL ganglia , *AFFECTIVE disorders , *SYSTEMATIC reviews , *METABOLITES , *MEDLINE , *PSYCHOSES , *ONLINE information services , *PROTON magnetic resonance spectroscopy - Abstract
Objective: Studies using proton magnetic resonance spectroscopy reveal substantial inconsistencies in the levels of brain glutamate, glutamine and glutamate + glutamine across schizophrenia spectrum disorders. This systematic review employs qualitative and quantitative methods to analyse the patterns and relationships between glutamatergic metabolites, schizophrenia spectrum disorders and brain regions. Methods: A literature search was conducted using various databases with keywords including glutamate, glutamine, schizophrenia, psychosis and proton magnetic resonance spectroscopy. Inclusion criteria were limited to case-control studies that reported glutamatergic metabolite levels in adult patients with a schizophrenia spectrum disorder diagnosis – i.e. first-episode psychosis, schizophrenia, treatment-resistant schizophrenia and/or ultra-treatment-resistant schizophrenia – using proton magnetic resonance spectroscopy at 3 T or above. Pooled study data were synthesized and analysed. Results: A total of 92 studies met the inclusion criteria, including 2721 healthy controls and 2822 schizophrenia spectrum disorder participants. Glu levels were higher in the basal ganglia, frontal cortex and medial prefrontal of first-episode psychosis participants, contrasting overall lower levels in schizophrenia participants. For Gln, strong differences in metabolite levels were evident in the basal ganglia, dorsolateral prefrontal cortex and frontal cortex, with first-episode psychosis showing significantly higher levels in the basal ganglia. In glutamate + glutamine, higher metabolite levels were found across schizophrenia spectrum disorder groups, particularly in the basal ganglia and dorsolateral prefrontal cortex of treatment-resistant schizophrenia participants. Significant relationships were found between metabolite levels and medication status, clinical measures and methodological variables. Conclusion: The review highlights abnormal glutamatergic metabolite levels throughout schizophrenia spectrum disorders and in specific brain regions. The review underscores the importance of standardized future research assessing glutamatergic metabolites using proton magnetic resonance spectroscopy due to considerable literature heterogeneity. [ABSTRACT FROM AUTHOR]
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- 2024
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34. Association Between Low Sex Hormone–Binding Globulin and Increased Risk of Type 2 Diabetes Is Mediated by Increased Visceral and Liver Fat: Results From Observational and Mendelian Randomization Analyses.
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Stangl, Theresa A., Wiepjes, Chantal M., Smit, Roelof A.J., van Hylckama Vlieg, Astrid, Lamb, Hildo J., van der Velde, Jeroen H.P.M., Winters-van Eekelen, Esther, Boone, Sebastiaan C., Brouwers, Martijn C.G.J., Rosendaal, Frits R., den Heijer, Martin, Heijboer, Annemieke C., and de Mutsert, Renée
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PROTON magnetic resonance spectroscopy , *TYPE 2 diabetes , *ADIPOSE tissues , *FAT , *LIVER - Abstract
The aim of this study was to investigate the associations among sex hormone–binding globulin (SHBG), visceral adipose tissue (VAT), liver fat content, and risk of type 2 diabetes (T2D). In the Netherlands Epidemiology of Obesity study, 5,690 women (53%) and men (47%) without preexisting diabetes were included and followed for incident T2D. SHBG concentrations were measured in all participants, VAT was measured using MRI, and liver fat content was measured using proton magnetic resonance spectroscopy in a random subset of 1,822 participants. We examined associations between SHBG and liver fat using linear regression and bidirectional Mendelian randomization analyses and between SHBG and T2D using Cox regression adjusted for confounding and additionally for VAT and liver fat to examine mediation. Mean age was 56 (SD 6) years, mean BMI was 30 (SD 4) kg/m2, median SHBG was 47 (interquartile range [IQR] 34–65) nmol/L in women and 34 (26–43) nmol/L in men, and median liver fat was 3.4% (IQR 1.6–8.2%) in women and 6.0% (2.9–13.5%) in men. Compared with the highest SHBG quartile, liver fat was 2.9-fold (95% CI 2.4, 3.4) increased in women and 1.6-fold (95% CI 1.3, 1.8) increased in men, and the hazard ratio of T2D was 4.9 (95% CI 2.4, 9.9) in women and 1.8 (1.1, 2.9) in men. Genetically predicted SHBG was associated with liver fat content (women: SD −0.45 [95% CI −0.55, −0.35]; men: natural logarithm, −0.25 [95% CI −0.34, −0.16]). VAT and liver fat together mediated 43% (women) and 60% (men) of the SHBG-T2D association. To conclude, in a middle-aged population with overweight, the association between low SHBG and increased risk of T2D was, for a large part, mediated by increased VAT and liver fat. Article Highlights: The objective of this study was to unravel the associations between sex hormone–binding globulin (SHBG) and type 2 diabetes (T2D). The extent to which the association between low SHBG and increased risk of T2D was mediated by visceral adipose tissue (VAT) and liver fat was examined. VAT and liver fat were found to mediate a large part of the association between SHBG and T2D. Both lifestyle and medical interventions that increase SHBG may reduce VAT, liver fat, and the risk of T2D. [ABSTRACT FROM AUTHOR]
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- 2024
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35. Metabolic Profile of Cerebellum in Posterior Fossa Tumor Survivors: Correlation With Memory Impairment.
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Tensaouti, F., Courbière, N., Cabarrou, B., Pollidoro, L., Roques, M., Sévely, A., Péran, P., Baudou, E., and Laprie, A.
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STATISTICAL correlation , *THREE-dimensional imaging , *INFRATENTORIAL brain tumors , *CANCER patients , *DESCRIPTIVE statistics , *LONGITUDINAL method , *CANCER chemotherapy , *CHOLINE , *RESEARCH , *CREATINE , *LACTATES , *CEREBELLUM , *COMPARATIVE studies , *MEMORY disorders , *PROTON magnetic resonance spectroscopy , *BIOMARKERS - Abstract
The cerebellum is a key structure in working and procedural memory. The aim of the present prospective exploratory study was to investigate, the metabolic characteristics of the cerebellum in posterior fossa tumor (PFT) survivors using 3D proton magnetic resonance spectroscopy imaging (3D MRSI), to determine whether metabolites could be useful biomarkers of memory impairment. Sixty participants were included in the IMPALA study, divided into three groups: 22 irradiated PFT, 17 nonirradiated PFT, and 21 healthy controls matched with irradiated PFT for age, sex, and handedness. PFT survivors were treated at least 5 years ago, either by surgery or a combination of surgery, chemotherapy, and radiotherapy. All participants underwent working and procedural memory tests and multimodal MRI including a 3D MRSI sequence. N-acetylaspartate (NAA), choline (Cho), creatine (Cr), and lactate (Lac) metabolite values were extracted from the cerebellum for comparisons between groups, correlations with neurocognitive test scores, and radiotherapy doses. Median (range) age at neurocognitive tests was 18 (7–26) years. Median Cho, Cr, NAA, and Lac values, and the ratio of NAA to the sum of metabolites were significantly lower for PFT survivors than for healthy controls (p < 0.05). Scores on working and procedural memory tests were significantly lower for PFT survivors (p < 0.004) and correlated with median and maximum Cho and NAA values (0.28 < r < 0.49, p < 0.04). Except for creatine, the other metabolites were not significantly different between irradiated and nonirradiated survivors. MRSI values in the cerebellum were not correlated with either total dose or doses received by this structure. Results revealed changes in cerebellar metabolic values in PFT survivors that were closely correlated with memory deficits, suggesting that some metabolites could be used as markers of cognitive decline, but this will require validation on a larger sample size. • 3D MRSI was used to assess metabolic profile of cerebellum in posterior fossa tumor (PFT) survivors. • Cerebellar metabolic values were lower in PFT survivors. • Metabolite values were closely correlated with memory deficits. • Some metabolites could be used as markers of memory impairment. [ABSTRACT FROM AUTHOR]
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- 2024
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36. Considerations for event‐related gamma‐aminobutyric acid functional magnetic resonance spectroscopy.
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Mullins, Paul G.
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PROTON magnetic resonance spectroscopy ,NUCLEAR magnetic resonance spectroscopy ,GABA ,BLOCK designs ,RESEARCH personnel - Abstract
The use of sequential proton magnetic resonance spectroscopy (MRS) to follow glutamate and gamma‐aminobutyric acid (GABA) changes during functional task‐based paradigms, functional MRS (fMRS), has increased. This technique has been used to investigate GABA dynamics during both sensory and behavioural tasks, usually with long 'block design' paradigms. Recently, there has been an increase in interest in the use of short stimuli and 'event‐related' tasks. While changes in glutamate can be readily followed by collecting multiple individual transients (or shots), measurement of GABA, especially at 3 T, is usually performed using editing techniques like Mescher–Garwood point‐resolved spectroscopy (MEGA‐PRESS), which by its nature is a dual shot approach. This poses problems when considering an event‐related experiment, where it is unclear when GABA may change, or how this may affect the individual subspectra of the MEGA‐PRESS acquisition. To address this issue, MEGA‐PRESS data were simulated to reflect the effect of a transient change in GABA concentration due to a short event‐related stimulus. The change in GABA was simulated for both the ON and OFF subspectra, and the effect of three different conditions (increase only during ON acquisition, increase during OFF acquisition and increase across both) on the corresponding edited GABA spectrum was modelled. Results show that a transient increase in GABA that only occurs during the ON subspectral acquisition, while not changing the results much from when GABA is changed across both conditions, will give a much larger change in the edited GABA spectrum than a transient increase that occurs only during the OFF subspectral acquisition. These results suggest that researchers should think carefully about the design of any event‐related fMRS studies using MEGA‐PRESS, as well as the analysis of other functional paradigms where transient changes in GABA may be expected. Experimental design considerations are therefore discussed, and suggestions are made. [ABSTRACT FROM AUTHOR]
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- 2024
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37. Quantitative US fat fraction for noninvasive assessment of hepatic steatosis in suspected metabolic-associated fatty liver disease
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Haohao Yin, Yunling Fan, Jifeng Yu, Bing Xiong, Boyang Zhou, Yikang Sun, Lifan Wang, Yuli Zhu, and Huixiong Xu
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Metabolic-associated fatty liver disease ,Ultrasonography ,Proton magnetic resonance spectroscopy ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 - Abstract
Abstract Objectives To evaluate the agreement between quantitative ultrasound system fat fraction (USFF) and proton magnetic resonance spectroscopy (1H-MRS) and the diagnostic value of USFF in assessing metabolic-associated fatty liver disease (MAFLD). Methods The participants with or suspected of MAFLD were prospectively recruited and underwent 1H-MRS, USFF, and controlled attenuation parameter (CAP) measurements. The correlation between USFF and 1H-MRS was assessed using Pearson correlation coefficients. The USFF diagnostic performance for different grades of steatosis was evaluated using receiver operating characteristic curve analysis (ROC) and was compared with CAP, visual hepatic steatosis grade (VHSG). Results A total of 113 participants (mean age 44.79 years ± 13.56 (SD); 71 males) were enrolled, of whom 98 (86.73%) had hepatic steatosis (1H-MRS ≥ 5.56%). USFF showed a good correlation (Pearson r = 0.76) with 1H-MRS and showed a linear relationship, which was superior to the correlation between CAP and 1H-MRS (Pearson r = 0.61). The USFF provided high diagnostic performance for different grades of hepatic steatosis, with ROC from 0.84 to 0.98, and the diagnostic performance was better than that of the CAP and the VHSG. The cut-off values of the USFF were different for various grades of steatosis, and the cut-off values for S1, S2, and S3 were 12.01%, 19.98%, and 22.22%, respectively. Conclusions There was a good correlation between USFF and 1H-MRS. Meanwhile, USFF had good diagnostic performance for hepatic steatosis and was superior to CAP and VHSG. USFF represents a superior method for noninvasive quantitative assessment of MAFLD. Critical relevance statement Quantitative ultrasound system fat fraction (USFF) accurately assesses liver fat content and has a good correlation with magnetic resonance spectroscopy (1H-MRS) for the assessment of metabolic-associated fatty liver disease (MAFLD), as well as for providing an accurate quantitative assessment of hepatic steatosis. Key Points Current diagnostic and monitoring modalities for metabolic-associated fatty liver disease have limitations. USFF correlated well with 1H-MRS and was superior to the CAP. USFF has good diagnostic performance for steatosis, superior to CAP and VHSG. Graphical Abstract
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- 2024
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38. Valorization of Sugarcane Bagasse for Co-Production of Poly(3-hydroxybutyrate) and Bacteriocin Using Bacillus cereus Strain S356.
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Khamberk, Sunisa, Thammasittirong, Sutticha Na-Ranong, and Thammasittirong, Anon
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PROTON magnetic resonance spectroscopy , *FOURIER transform infrared spectroscopy , *NUCLEAR magnetic resonance spectroscopy , *BACILLUS cereus , *RENEWABLE natural resources , *BIODEGRADABLE plastics - Abstract
Poly(3-hydroxybutyrate) (P(3HB)) is an attractive biodegradable plastic alternative to petroleum-based plastic. However, the cost of microbial-based bioplastic production mainly lies in the cultivation medium. In this study, we screened the isolates capable of synthesizing P(3HB) using sugarcane bagasse (SCB) waste as a carbon source from 79 Bacillus isolates that had previously shown P(3HB) production using a commercial medium. The results revealed that isolate S356, identified as Bacillus cereus using 16S rDNA and gyrB gene analysis, had the highest P(3HB) accumulation. The highest P(3HB) yield (5.16 g/L, 85.3% of dry cell weight) was achieved by cultivating B. cereus S356 in an optimal medium with 1.5% total reducing sugar with SCB hydrolysate as the carbon source and 0.25% yeast extract as the nitrogen source. Transmission electron microscopy analysis showed the accumulation of approximately 3–5 P(3HB) granules in each B. cereus S356 cell. Proton nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy analyses confirmed that the polymer extracted from B. cereus S356 was P(3HB). Notably, during cultivation for P(3HB) plastic production, B. cereus S356 also secreted bacteriocin, which had high antibacterial activity against the same species (Bacillus cereus). Overall, this work demonstrated the possibility of co-producing eco-friendly biodegradable plastic P(3HB) and bacteriocin from renewable resources using the potential of B. cereus S356. [ABSTRACT FROM AUTHOR]
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- 2024
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39. Recycling of polyester bottle waste to generate functional acid dye in situ on wool.
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Singh, Ankit and Sheikh, Javed
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NATURAL dyes & dyeing ,FOURIER transform infrared spectroscopy techniques ,PROTON magnetic resonance spectroscopy ,NUCLEAR magnetic resonance spectroscopy ,BEVERAGE container recycling ,POLYESTERS ,WOOL - Abstract
Nowadays, waste management is gaining popularity to reduce the environmental impact made by human beings. There is a dire need to decrease the pollution caused by plastic materials. A gradual rise in the demand for polyester bottles has generated a need to recycle these materials. In the present work, an aromatic amine (4,4′‐(1,4‐phenylenebis(1,3,4‐oxadiazole‐5,2‐diyl)) dianiline) was prepared from the polyester bottle waste. The successful synthesis and chemical structure of the amine was confirmed by various characterization techniques such as Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy (1H NMR), and 13C NMR. The amine was diazotized and coupled with H‐acid (4‐amino‐5‐hydroxy‐2,7‐naphthalene disulfonic acid)‐treated wool fabric to generate acid dye in situ on the fabric. The coloration (L*, a*, b*, and K/S) and fastness properties of dyed wool were evaluated, and the samples were further analyzed for antibacterial and UV‐protective properties. The dyed wool was also characterized by FTIR to confirm the presence of the aromatic group of the dye. The introduction of dye structure on the wool increased the thermal stability of the fabric, which was confirmed through thermogravimetric analysis analysis. Antibacterial activity (>70%) and excellent UV protection were retained by dyed wool after 20 washes. Furthermore, the dyed wool was found nontoxic under the cytotoxicity evaluation test. [ABSTRACT FROM AUTHOR]
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- 2024
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40. Reduction of myocardial lipid content assessed by H1 magnetic resonance spectroscopy in dyslipidemic patients after statins.
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Elmenyawy, Eslam Elsayed Mohamed, Fadl, Hend Gamal Abu-El, Waly, Hesham Mohammed Fathy, Maaty, Abdul Razek Abdul Lateef, and Abdelaziz, Hanaa Mahmoud Mohammad
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HEART metabolism ,LIPID metabolism ,LIPID analysis ,HYPERLIPIDEMIA ,ACADEMIC medical centers ,T-test (Statistics) ,DATA analysis ,FISHER exact test ,TREATMENT effectiveness ,DESCRIPTIVE statistics ,MANN Whitney U Test ,CHI-squared test ,LONGITUDINAL method ,CLINICAL pathology ,STATINS (Cardiovascular agents) ,CASE-control method ,RESEARCH methodology ,STATISTICS ,COMPARATIVE studies ,DATA analysis software ,PROTON magnetic resonance spectroscopy ,PHARMACODYNAMICS ,EVALUATION - Abstract
Background: Dyslipidemia is one of the main modifiable risk factors for cardiovascular diseases, which accounts for one third of total deaths worldwide. Statin is considered the cornerstone therapy for treating dyslipidemic patients. H1 Cardiac magnetic resonance spectroscopy (MRS) is a special non-invasive, non-irradiating method for assessing myocardial lipid content in vivo in both health and disease. Aim: To compare dyslipidemic patients and healthy individuals, and to detect the efficacy of statin on the myocardial lipid content in dyslipidemic patients to detect if there will be changes 6 months after starting statin therapy. Methods: Laboratory lipid profile and myocardial lipid content had been measured by H1 MRS in thirty dyslipidemic patients and fifteen healthy matched age and sex individuals as a control group, then dyslipidemic patients were followed up 6 months after statin therapy at Cardiovascular Medicine and Radiology departments; Mansoura University Hospitals, Dakahlia Governorate, Egypt, during the period from January 2020 to October 2022. Results: A total of thirty dyslipidemic patients were screened for lipid profile, myocardial lipid content by H1 MRS; 56.67% were male, with a mean age of 49 ± 9.19 years, and compared with fifteen healthy matched age and sex individuals as a control group. Laboratory lipid profile, and triglyceride lipid concentration by MRS were significantly higher in dyslipidemic group before initiating statin therapy compared to control group (p value, 0.001, 0.019 respectively). Median LDL levels were 161.10 ± 30.28 mg/dl before the start of statin therapy and were 114.27 ± 48.33 mg/dl after statin therapy (p < 0.001). There was a statistically significant reduction in triglyceride lipid concentration in dyslipidemic patients after 6 months of statin therapy: from 0.011 (0.001–0.55 (mmol/l), to 0.0025 (0.001–0.04 mmol/l) with a p value < 0.001. Conclusions: Increased myocardial lipid content as measured by magnetic resonance spectroscopy was demonstrated in dyslipidemic patients in our study that decreased after 6 months of statin therapy. [ABSTRACT FROM AUTHOR]
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- 2024
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41. Short-cut route validated for monitoring fentanyl and its metabolite in urine using LC–MS/MS, in a wide concentration range.
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Cavus Yonar, Fatma, Anılanmert, Beril, and Acikkol, Munevver
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FENTANYL , *LIQUID chromatography-mass spectrometry , *DRUG monitoring , *PROTON magnetic resonance spectroscopy , *URINE , *TRANSDERMAL medication - Abstract
Background: Fentanyl is a highly potent analgesic, used in surgery, frequently abused or used in drug-facilitated crimes (DFC) and in military activities. It is also increasingly used in the treatment of chronic pain (especially in cancer patients). The improper use of transdermal patch forms can cause toxicity and deaths, related to overdose or combined use with other drug substances. Methods are needed for fast, reliable and inexpensive fentanyl detection and we aimed to develop such a method in urine using LC–MS/MS, especially for toxic and fatal concentrations which lack in the literature. Results: An LC–MS/MS method has been presented for the co-determination of fentanyl and its main metabolite, norfentanyl in urine. The recoveries of the extraction method were 95(± 6)% and 70(± 9)% for fentanyl and norfentanyl, respectively. LOD and LOQ values are 1.7 and 14.0 ng/mL for fentanyl, while they were 20.6 ng/mL and 42.0 ng/mL for norfentanyl. Conclusion: A rapid, sensitive, very practical, inexpensive and a high-recovery analysis method is developed and validated. This is the only fentanyl monitoring LC–MS/MS method in urine having a linearity over a wide range up to 500.0 ng/mL and its success is demonstrated on real samples in the therapeutic drug monitoring of fentanyl and is expected to contribute to clarify intoxications/deaths related to its use. [ABSTRACT FROM AUTHOR]
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- 2024
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42. Endocannabinoid levels in plasma and neurotransmitters in the brain: a preliminary report on patients with a psychotic disorder and healthy individuals.
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van Hooijdonk, Carmen F. M., Balvers, Michiel G. J., van der Pluijm, Marieke, Smith, Charlotte L. C., de Haan, Lieuwe, Schrantee, Anouk, Yaqub, Maqsood, Witkamp, Renger F., van de Giessen, Elsmarieke, van Amelsvoort, Therese A. M. J., Booij, Jan, and Selten, Jean-Paul
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BRAIN physiology , *AUTISM risk factors , *SCHIZOPHRENIA risk factors , *DOPAMINE analysis , *RISK assessment , *T-test (Statistics) , *MULTIPLE regression analysis , *POSITRON emission tomography , *DESCRIPTIVE statistics , *MANN Whitney U Test , *GLUTAMIC acid , *AMINOBUTYRIC acid , *DRUGS , *PSYCHOSES , *ASPERGER'S syndrome , *NEUROTRANSMITTERS , *PROTON magnetic resonance spectroscopy - Abstract
Background: Interactions between the endocannabinoid system (ECS) and neurotransmitter systems might mediate the risk of developing a schizophrenia spectrum disorder (SSD). Consequently, we investigated in patients with SSD and healthy controls (HC) the relations between (1) plasma concentrations of two prototypical endocannabinoids (N-arachidonoylethanolamine [anandamide] and 2-arachidonoylglycerol [2-AG]) and (2) striatal dopamine synthesis capacity (DSC), and glutamate and y-aminobutyric acid (GABA) levels in the anterior cingulate cortex (ACC). As anandamide and 2-AG might reduce the activity of these neurotransmitters, we hypothesized negative correlations between their plasma levels and the abovementioned neurotransmitters in both groups. Methods: Blood samples were obtained from 18 patients and 16 HC to measure anandamide and 2-AG plasma concentrations. For all subjects, we acquired proton magnetic resonance spectroscopy scans to assess Glx (i.e. glutamate plus glutamine) and GABA + (i.e. GABA plus macromolecules) concentrations in the ACC. Ten patients and 14 HC also underwent [18F]F-DOPA positron emission tomography for assessment of striatal DSC. Multiple linear regression analyses were used to investigate the relations between the outcome measures. Results: A negative association between 2-AG plasma concentration and ACC Glx concentration was found in patients (p = 0.008). We found no evidence of other significant relationships between 2-AG or anandamide plasma concentrations and dopaminergic, glutamatergic, or GABAergic measures in either group. Conclusions: Our preliminary results suggest an association between peripheral 2-AG and ACC Glx levels in patients. [ABSTRACT FROM AUTHOR]
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- 2024
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43. Functional and structural neuroimaging in premenstrual dysphoric disorder: A systematic review.
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Monteiro, Dennison Carreiro, Ramos, Clarence da Silva, Alves, Luís Eduardo Nogueira Nóbrega, Cantilino, Amaury, and Sougey, Everton Botelho
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DIFFUSION magnetic resonance imaging , *FUNCTIONAL magnetic resonance imaging , *MAGNETIC resonance imaging , *PROTON magnetic resonance spectroscopy , *PREMENSTRUAL syndrome - Abstract
This systematic review aimed to summarize the most recent data on changes in brain structure and function in premenstrual dysphoric disorder (PMDD) as well as elucidate the possible correlations between these findings and symptom severity. Articles published in PubMed, EMBASE, ScienceDirect, PsycInfo, Web of Science, and Scopus from inception until April 2023 were systematically reviewed according to the PICO framework: population (women with PMDD), intervention (neuroimaging study), control (healthy subjects), and outcome (neuroimaging changes). In total, 1026 individuals were included from controlled (n = 22) and non-controlled (n = 2) trials. Among them, 608 had PMDD, and 418 were healthy controls. Different neuroimaging methods were addressed, such as task-based functional magnetic resonance imaging (MRI), resting-state functional MRI, proton magnetic resonance spectroscopy, diffusion tensor imaging, proton emission tomography, and structural MRI. Despite the absence of consensual results, several brain structures have been implicated in PMDD, including the prefrontal cortex, amygdala, hippocampus, insula, basal ganglia, and cerebellum. In addition, some brain changes are related to the intensity of symptoms and phases of the menstrual cycle, such as the correlation between depressive symptoms and increased serotonin transporter binding potential in the midbrain during the luteal phase. • Current findings suggest an impairment in the functioning of top-down emotional control in patients with PMDD. • Patient with PMDD demonstrates structural impairment of corticolimbic connections. • PMDD exhibited corticocortical hypoconnectivity and subcortical hyperconnectivity. • From the periovulatory to the premenstrual phase, patients with PMDD increased availability of the serotonin transporter. • Patients with PMDD have altered gray matter volume in the amygdala, hippocampus, striatum, and cerebellum. [ABSTRACT FROM AUTHOR]
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- 2024
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44. Clinical value of magnetic resonance spectroscopy in assessment of early curing impact of concurrent chemoradiotherapy after highgrade glioma surgery.
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Yu Gao, Wen-Ming Yan, Hong-Wei Wang, Xin-Hong Li, Ru-Tao Zhang, Yu-Bo Dong, Wei-Han Zhang, and Qi-Wei Guo
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PROTON magnetic resonance spectroscopy , *NUCLEAR magnetic resonance spectroscopy , *CHEMORADIOTHERAPY , *NERVOUS system tumors , *GLIOMAS , *TUMOR treatment - Abstract
Background/Aim. High-grade glioma (HGG) is an interstitial cell-derived primary tumor of the nervous system. The current guidelines for the diagnosis and treatment of glioma recommend the maximum safe range of tumor resection for treatment methods. Adjuvant concurrent chemoradiotherapy is recommended after surgery, followed by six cycles of single-drug chemotherapy, temozolomide. Evaluation of the early efficacy of concurrent chemoradiotherapy after HGG surgery, especially for patients with a high risk of recurrence, is a crucial step in enhancing the treatment efficiency for patients diagnosed with HGG. In this study, we investigated the clinical utility of magnetic resonance (MR) spectroscopy (MRS) in assessing the early curing impact of concurrent chemoradiotherapy following HGG surgery. Methods. A total of 50 patients with incomplete resection or suspected residual postoperative HGG, treated in the radiotherapy department of our hospital between January 2016 and June 2021, were selected for routine concurrent chemoradiotherapy. Conventional MR imaging and MRS were performed one week prior to treatment and one month after treatment to assess changes in specific brain metabolites. All 50 patients were followed up for 6 to 12 months. Based on the follow-up results, the patients were divided into two groups: the tumor recurrence group and the tumor suppression group. One month after the end of the treatment, the differences in levels of brain metabolites between the two groups were analyzed using MRS. Results. The levels of N-acetylaspartate (NAA) and creatine (Cr) increased after radiotherapy, while choline (Cho) peak value, and Cho/Cr, NAA/Cr, and Cho/NAA ratios decreased compared to pre-treatment levels. There were statistically significant differences in the NAA peak value, and Cho/Cr, and Cho/NAA ratios in the tumor enhancement area before and after treatment (p < 0.05). There were also statistically significant differences in Cho/Cr ratio in the peritumoral edema area before and after treatment (p < 0.05). Conclusion. After concurrent chemoradiotherapy, MRS can be used to detect early metabolic changes in the tumor enhancement and peritumoral edema areas of HGG. [ABSTRACT FROM AUTHOR]
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- 2024
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45. Retrospective Research of Clinical and Hematological Changes Occurred by del Nido Cardioplegia in the Perioperative Period of Patients who Underwent Open-Heart Surgery.
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Özer, Abdullah, Koçak, Başak, Arslan, Mustafa, Şimşek, Elif, Özdemirkan, Aycan, Ünal, Yusuf, İriz, Erkan, Zor, Hakan, and Oktar, Levent
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CARDIAC surgery , *INDUCED cardiac arrest , *PREOPERATIVE period , *MEDICAL research , *ASPARTATE aminotransferase , *PROTON magnetic resonance spectroscopy , *CARDIOPULMONARY bypass - Abstract
Objective: Aortic cross-clamping and postischemic myocardial dysfunction are fundamentally related to myocardial protection during open-heart surgery. Various cardioplegia solutions have been developed because of this issue. del Nido cardioplegia (DNC) solution is one of these solutions and has a vital impact on metabolic markers and cardiac protection in individuals of all ages. This study aimed to examine the effects of DNC on the perioperative follow-up period after cardiac surgery. Methods: Preoperative and postoperative variations in selected biochemical and hematological variables of 71 patients who underwent open-heart surgery in our medical faculty between 2018 and 2020 were retrospectively examined and compared with normal values. SPSS 20.0 statistical software was used, and a statistically significant difference was defined as p<0.05. Results: Hemoglobin, platelet, albumin, and uric acid levels were significantly lower at the end of cardiopulmonary bypass and the postoperative 24th hour than in the preoperative period. At the end of the cardiopulmonary bypass and the postoperative 24th hour, aspartate aminotransferase and lactate dehydrogenase levels were significantly greater than those in the preoperative period. Remarkable increases in hemoglobin, albumin, urea, and platelets in the postoperative 24th hour compared with the end of cardiopulmonary bypass were noted. We also reported substantial differences in glucose, lactate, creatine kinase-MB, and troponin levels. Conclusion: We found significant changes in different parameters critical for the perioperative period of open-heart surgery. Although our study found DNC to be a safer option, additional research into clinical usage is required. [ABSTRACT FROM AUTHOR]
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- 2024
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46. In vivo brain MRS at a 1.5T clinical scanner: Optimized derivative fast Fourier transform for high-resolution spectra from time signals encoded with and without water suppression.
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Belkić, Dževad and Belkić, Karen
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FAST Fourier transforms , *PROTON magnetic resonance spectroscopy , *SIGNAL-to-noise ratio , *WHITE matter (Nerve tissue) , *MAGNETIC fields - Abstract
We study single-voxel in vivo proton magnetic resonance spectroscopy (MRS) of white matter in the brain of a 25 year old healthy male volunteer. The free induction decay (FID) data of short length (0.5KB) are encoded at a long echo time (272 ms) with and without water suppression at a clinical scanner of a weak magnetic field (1.5T). For these FIDs, the fast Fourier transform (FFT) gives sparse, rough and metabolically uninformative spectra. In such spectra, resolution and signal to noise ratio (SNR) are poor. Exponential or Gaussian filters applied to the FIDs can improve SNR in the FFT spectra, but only at the expense of the worsened resolution. This impacts adversely on in vivo MRS for which both resolution and SNR of spectra need to be very good or excellent, without necessarily resorting to stronger magnetic fields. Such a long sought goal is at last within reach by means of the optimized derivative fast Fourier transform (dFFT), which dramatically outperforms the FFT in every facet of signal estimations. The optimized dFFT simultaneously improves resolution and SNR in derivative spectra. They are presently shown to be of comparably high quality irrespective of whether water is suppressed or not in the course of FID encodings. The ensuing benefits of utmost relevance in the clinic include a substantial shortening of the patient examination time. The implied significantly better cost-effectiveness should make in vivo MRS at low-field clinical scanners (1.5T) more affordable to ever larger circles of hospitals worldwide. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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- View/download PDF
47. The Glutamatergic Effects of Clinical Repetitive Transcranial Magnetic Stimulation in Depressed Populations: A Preliminary Meta-Analysis of Proton Magnetic Resonance Spectroscopy Studies.
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Pecsok, Maggie K., Mordy, Arianna, Cristancho, Mario A., Oathes, Desmond, and Roalf, David R.
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PROTON magnetic resonance spectroscopy , *TRANSCRANIAL magnetic stimulation , *MENTAL depression , *NEUROPLASTICITY , *GABA - Abstract
Introduction: Repetitive transcranial magnetic stimulation (rTMS) alleviates symptoms of major depressive disorder, but its neurobiological mechanisms remain to be fully understood. Growing evidence from proton magnetic resonance spectroscopy (1HMRS) studies suggests that rTMS alters excitatory and inhibitory neurometabolites. This preliminary meta-analysis aims to quantify current trends in the literature and identify future directions for the field. Methods: Ten eligible studies that quantified Glutamate (Glu), Glu+Glutamine (Glx), or GABA before and after an rTMS intervention in depressed samples were sourced from PubMed, MEDLINE, PsychInfo, Google Scholar, and primary literature following PRISMA guidelines. Data were pooled using a random-effects model, Cohen's d effect sizes were calculated, and moderators, such as neurometabolite and 1HMRS sequence, were assessed. It was hypothesized that rTMS would increase cortical neurometabolites. Results: Within-subjects data from 224 cases encompassing 31 neurometabolite effects (k) were analyzed. Active rTMS in clinical responders (n = 128; k = 22) nominally increased glutamatergic neurometabolites (d = 0.15 [95% CI: −0.01, 0.30], p = 0.06). No change was found in clinical nonresponders (p = 0.8) or sham rTMS participants (p = 0.4). A significant increase was identified in Glx (p = 0.01), but not Glu (p = 0.6). Importantly, effect size across conditions were associated with the number of rTMS pulses patients received (p = 0.05), suggesting dose dependence. Conclusions: Clinical rTMS is associated with a nominal, dose-dependent increase in glutamatergic neurometabolites, suggesting rTMS may induce Glu-dependent neuroplasticity and upregulate neurometabolism. More, larger scale studies adhering to established acquisition and reporting standards are needed to further elucidate the neurometabolic mechanisms of rTMS. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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48. Impact of lifetime stressor exposure on neuroenergetics in schizophrenia spectrum disorders.
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Chiappelli, Joshua, Savransky, Anya, Ma, Yizhou, Gao, Si, Kvarta, Mark D., Kochunov, Peter, Slavich, George M., and Hong, L. Elliot
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SCHIZOPHRENIA , *PROTON magnetic resonance spectroscopy , *CINGULATE cortex , *CEREBRAL cortex , *MENTAL illness - Abstract
N -acetylasparate and lactate are two prominent brain metabolites closely related to mitochondrial functioning. Prior research revealing lower levels of NAA and higher levels of lactate in the cerebral cortex of patients with schizophrenia suggest possible abnormalities in the energy supply pathway necessary for brain function. Given that stress and adversity are a strong risk factor for a variety of mental health problems, including psychotic disorders, we investigated the hypothesis that stress contributes to abnormal neuroenergetics in patients with schizophrenia. To test this hypothesis, we used the Stress and Adversity Inventory (STRAIN) to comprehensively assess the lifetime stressor exposure profiles of 35 patients with schizophrenia spectrum disorders and 33 healthy controls who were also assessed with proton magnetic resonance spectroscopy at the anterior cingulate cortex using 3 Tesla scanner. Consistent with the hypothesis, greater lifetime stressor exposure was significantly associated with lower levels of N -acetylasparate (β = −0.36, p =.005) and higher levels of lactate (β = 0.43, p =.001). Moreover, these results were driven by patients, as these associations were significant for the patient but not control group. Though preliminary, these findings suggest a possible role for stress processes in the pathophysiology of abnormal neuroenergetics in schizophrenia. [ABSTRACT FROM AUTHOR]
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- 2024
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49. Impact of the serum creatinine and cystatin C ratio for prediction of sarcopenia and prognosis in biliary tract cancer.
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Fukushima, Ryosuke, Harimoto, Norifumi, Okuyama, Takayuki, Seki, Takaomi, Hoshino, Kouki, Hagiwara, Kei, Kawai, Shunsuke, Ishii, Norihiro, Tsukagoshi, Mariko, Igarashi, Takamichi, Araki, Kenichiro, and Shirabe, Ken
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CYSTATIN C , *SARCOPENIA , *PROTON magnetic resonance spectroscopy , *CANCER prognosis , *PROGNOSIS , *GALLBLADDER cancer ,BILIARY tract cancer - Abstract
Background: Sarcopenia is a poor prognostic factor in cancer patients. In recent years, there have been reports that serum creatinine and cystatin C (Cr/CysC) ratio is associated with sarcopenia. However, the prognostic value of the Cr/CysC ratio in biliary tract cancer is unclear. We evaluated the impact of the Cr/CysC ratio on sarcopenia and prognosis in biliary tract cancer. Methods: We retrospectively reviewed the records of 190 patients with biliary tract cancer who had undergone surgical resection from January 2017 to March 2023. Frozen serum samples collected at the time of surgery were used to measure CysC. We calculated the Cr/CysC ratio and investigated the relationship with sarcopenia and the prognostic significance. Results: We calculated the cutoff value of the Cr/CysC ratio for low skeletal muscle index (SMI) (< 42 cm2/m2 for males and < 38 cm2/m2 for females). The optimal cutoff value of the Cr/CysC ratio was 0.848. The low Cr/CysC ratio group was significantly associated with higher preoperative CRP and lower albumin, lower SMI, lower handgrip strength, and higher intramuscular adipose tissue content. In multivariate analysis, patients with a low Cr/CysC ratio showed poorer overall survival (hazard ratio 2.60, 95% confidence interval 1.07–6.29, p = 0.033), which was significantly worse than in those with a high Cr/CysC ratio. Conclusions: In patients with biliary tract cancer, the Cr/CysC ratio showed weak correlation with sarcopenic indicators. However, the Cr/CysC ratio could be strong prognostic factor in biliary tract cancer. [ABSTRACT FROM AUTHOR]
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- 2024
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50. Lauryl alcohol functionalized citric acid-based dendrimers as the drug carrier for in vitro evaluation.
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Motamedi, Sanaz, Pooresmaeil, Malihe, and Namazi, Hassan
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DRUG carriers , *DODECANOL , *NUCLEAR magnetic resonance spectroscopy , *DENDRIMERS , *PROTON magnetic resonance spectroscopy , *FOURIER transform infrared spectroscopy - Abstract
Today, depression is a usual mental disorder that is associated with a depressed mood and loss of interest. Therefore, considering these problems, the main goal of the present research work was to develop a new multifunctional cost-effective citric acid-based dendritic structure (CAD) with the capability of antidepressant drug delivery. For this, at first, three different generations of citric acid dendrimer (CAD G1, CAD G2, and CAD G3) were synthesized through divergent methods. Afterward, each of the synthesized dendrimers was functionalized with lauryl alcohol (LAU), and CAD Gn-LAU was obtained. The fabricated samples were characterized for acute synthesis employing the Fourier transform infrared spectroscopy and proton nuclear magnetic resonance (1H NMR). The ratio of the PEG protons to LAU protons specified the percentage of LAU grafting on the dendrimer surface. The outcome displayed that the CAD G1, CAD G2, and CAD G3 were functionalized with LAU groups respectively at about 60, 60, and 33%. All CAD Gn (1–3) were able to encapsulate the fluoxetine (FXN) in its pristine or LAU functionalized form via high-affinity interactions. The highest FXN loading percentage was observed for CAD G3-LAU, at about 52%. The FXN release study approved the pH sensitivity of the prepared systems, which is the main criterion in a specific therapy. All in all, the findings met the aim and can suggest that the synthesized CAD Gn-LAU dendrimers are efficient carriers for FXN delivery in the desired way. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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