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Patient-derived xenografts (PDX) are high-fidelity cancer models typically credentialled by genomics, transcriptomics and proteomics. Characterization of metabolic reprogramming, a hallmark of cancer, is less frequent. Dysregulated metabolism is a key feature of clear cell renal cell carcinoma (ccRCC) and authentic preclinical models are needed to evaluate novel imaging and therapeutic approaches targeting metabolism. We characterized 5 PDX from high-grade or metastatic ccRCC by multiparametric magnetic resonance imaging (MRI) and steady state metabolic profiling and flux analysis. Similar to MRI of clinical ccRCC, T2-weighted images of orthotopic tumors of most PDX were homogeneous. The increased hyperintense (cystic) areas observed in one PDX mimicked the cystic phenotype typical of some RCC. The negligible hypointense (necrotic) areas of PDX grown under the highly vascularized renal capsule are beneficial for preclinical studies. Mean apparent diffusion coefficient (ADC) values were equivalent to those of ccRCC in human patients. Hyperpolarized (HP) [1-13C]pyruvate MRI of PDX showed high glycolytic activity typical of high-grade primary and metastatic ccRCC with considerable intra- and inter-tumoral variability, as has been observed in clinical HP MRI of ccRCC. Comparison of steady state metabolite concentrations and metabolic flux in [U-13C]glucose-labeled tumors highlighted the distinctive phenotypes of two PDX with elevated levels of numerous metabolites and increased fractional enrichment of lactate and/or glutamate, capturing the metabolic heterogeneity of glycolysis and the TCA cycle in clinical ccRCC. Culturing PDX cells and reimplanting to generate xenografts (XEN), or passaging PDX in vivo, altered some imaging and metabolic characteristics while transcription remained like that of the original PDX. These findings show that PDX are realistic models of ccRCC for imaging and metabolic studies but that the plasticity of metabolism must be considered when manipulating PDX for preclinical studies.

Currently, no clinical methods reliably predict the development of castration-resistant prostate cancer (CRPC) that occurs almost universally in men undergoing androgen deprivation therapy. Hyperpolarized (HP) 13C magnetic resonance imaging (MRI) could potentially detect the incipient emergence of CRPC based on early metabolic changes. To characterize metabolic shifts occurring upon the transition from androgen-dependent to castration-resistant prostate cancer (PCa), the metabolism of [U-13C]glucose and [U-13C]glutamine was analyzed by nuclear magnetic resonance spectroscopy. Comparison of steady-state metabolite concentrations and fractional enrichment in androgen-dependent LNCaP cells and transgenic adenocarcinoma of the murine prostate (TRAMP) murine tumors versus castration-resistant PC-3 cells and treatment-driven CRPC TRAMP tumors demonstrated that CRPC was associated with upregulation of glycolysis, tricarboxylic acid metabolism of pyruvate; and glutamine, glutaminolysis, and glutathione synthesis. These findings were supported by 13C isotopomer modeling showing increased flux through pyruvate dehydrogenase (PDH) and anaplerosis; enzymatic assays showing increased lactate dehydrogenase, PDH and glutaminase activity; and oxygen consumption measurements demonstrating increased dependence on anaplerotic fuel sources for mitochondrial respiration in CRPC. Consistent with ex vivo metabolomic studies, HP [1-13C]pyruvate distinguished androgen-dependent PCa from CRPC in cell and tumor models based on significantly increased HP [1-13C]lactate.

The diagnosis of pediatric tuberculosis (TB) remains a major challenge, hence the evaluation of new tools for improved diagnostics is urgently required. We investigated the serum metabolic profile of children with culture‐confirmed intra‐thoracic TB (ITTB) (n = 23) and compared it with those of non‐TB controls (NTCs) (n = 13) using proton NMR spectroscopy‐based targeted and untargeted metabolomics approaches. In targeted metabolic profiling, five metabolites (histidine, glycerophosphocholine, creatine/phosphocreatine, acetate, and choline) differentiated TB children from NTCs. Additionally, seven discriminatory metabolites (N‐α‐acetyl‐lysine, polyunsaturated fatty acids, phenylalanine, lysine, lipids, glutamate + glutamine, and dimethylglycine) were identified in untargeted metabolic profiling. The pathway analysis revealed alterations in six metabolic pathways. The altered metabolites were associated with impaired protein synthesis, hindered anti‐inflammatory and cytoprotective mechanisms, abnormalities in energy generation processes and membrane metabolism, and deregulated fatty acid and lipid metabolisms in children with ITTB. The diagnostic significance of the classification models obtained from significantly distinguishing metabolites showed sensitivity, specificity, and area under the curve of 78.2%, 84.6%, and 0.86, respectively, in the targeted profiling and 92.3%, 100%, and 0.99, respectively, in the untargeted profiling. Our findings highlight detectable metabolic changes in childhood ITTB; however, further validation is warranted in a large cohort of the pediatric population. [ABSTRACT FROM AUTHOR]

In ischemic stroke, reperfusion after thrombolysis is associated with secondary brain damage. Dihydromyricetin (DHM), a flavonoid, has shown neuroprotective effects through anti-oxidant, anti-inflammatory and anti-apoptotic properties. This study investigates the potential of DHM, given postreperfusion in middle cerebral artery occlusion (MCAo) model of stroke in rats. MCAo surgery was performed in male Wistar rats. Reperfusion was performed after 90 min of ischemia. DHM (50 and 100 mg/kg) was administered 10–15 min and 2 h postreperfusion followed by daily dosing for 2 more days. Neurobehavioral parameters and infarct size (TTC staining) were assessed after 72 h. The effective dose (100 mg/kg) was then used to study reduction in infarct size (measured by MRI) and effect on apoptosis (evaluated by protein expression of Bax, Bcl-2 and cleaved caspase-3 and TUNEL assay) in peri-infarct cortex. Furthermore, effects of DHM on neuronal damage and activation of astrocytes were studied by immunofluorescence. Poststroke DHM (100 mg/kg) administered for 3 days showed significant improvements in motor-coordination and infarct damage (TTC staining and MRI). MCAo-induced altered apoptotic proteins were normalized to a significant extent in peri-infarct cortex with DHM treatment. Data from TUNEL assay were complementary to the effects on apoptotic proteins. Additionally, DHM caused a significant reduction in the number of reactive astrocytes when compared with the MCAo group. This study demonstrated the efficacy of subacute DHM treatment in ischemia/reperfusion injury by modulating apoptosis and astrogliosis in the peri-infarct cortex. This suggests the potential of DHM in attenuating disease progression. [ABSTRACT FROM AUTHOR]

PURPOSE The aim of the study was to radiolabel, characterize, and perform in vitro and in vivo assessment of Technetium-99m (Tc-99m) tamoxifen for screening ER expressing lesions in breast cancer patients. METHODS In this study, tamoxifen has been radiolabeled with Tc-99m via Tc-99m-tricarbonyl core. The characterization and quality control tests of Tc-99m-tamoxifen were performed. In vitro recep- tor binding and blocking studies were performed in both positive control (MCF-7) and negative control cell lines (MDA-MB-231). Normal biodistribution studies were performed in female Wistar albino rats. The pilot clinical studies were performed in 4 ER-expressing breast cancer patients. Of the 4 patients, 1 was on tamoxifen therapy. All 4 patients had also undergone Fluorine-18 fluorodeoxyglucose (F-18-FDG) positron emission tomography/computed tomography. RESULTS Tamoxifen was radiolabeled with Tc-99m via Tc-99m-tricarbonyl core with more than 95% radio- chemical yield. Mass spectra showed a peak corresponding to the molecular weight of Tc-99m- tricarbonyl and Tc-99m-tamoxifen. The site of binding of Tc-99m-tricarbonyl with tamoxifen was determined by proton nuclear magnetic resonance. The Tc-99m-tamoxifen showed 30% binding with MCF-7 and only 1%-2% receptor binding with MDA-MB-231 cell lines. Also, the percentage of receptor binding was drastically reduced (up to 72%) when ER was saturated with 50 times the excess molar ratio of unlabeled tamoxifen. In a pilot patient study, Tc-99m-tamoxifen uptake was observed in primary and metastatic lesions. However, no uptake was observed in a patient who was on tamoxifen therapy. The uptake of F-18-FDG was noted in all the patients. CONCLUSION Tamoxifen was radiolabeled with an in-house-synthesized Tc-99m-tricarbonyl core. The radio- labeled complex has been characterized and evaluated for receptor specificity in in vitro and in vivo studies. Also, this is the first clinical study using Tc-99m-tamoxifen for imaging ER. More patients need to be evaluated to further explore the role of Tc-99m-tamoxifen in ER-expressing lesions. [ABSTRACT FROM AUTHOR]

Metabonomics study provides a comprehensive metabolic profile of biological samples using techniques like mass spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. The metabolites identified are later analysed using multivariate statistical methods. Metabonomics has the potential to provide putative biomarker/s for disease diagnosis and for monitoring the disease progression and can be used in patient management. Recently, a few metabonomics studies have been reported on blood sera, urine and intestinal mucosal biopsies of celiac disease (CeD) patients using proton NMR. Significantly decreased levels of amino acids, methylamine, lactate, lipids, pyruvate, creatinine, choline and glycoprotein and increased levels of glucose and ß-hydroxybutyrate have been reported in blood sera of CeD patients. In intestinal mucosal biopsies of CeD patients, a higher concentration of isoleucine, leucine, aspartate, succinate and pyruvate and lower concentration of glycerophosphocholine was seen as compared to controls. These studies indicates that the metabonomics study of CeD using in-vitro NMR spectroscopy helps in the determination of metabolic signature/s of the disease. It also provides an insight into the biochemistry of the disease and also helps in the identification of metabolites that could serve as putative biomarker/s for the diagnosis of CeD. This review focuses on the application of NMR based metabonomics in CeD and highlights the potential of NMR based metabonomics in the identification of biomarker/s for diagnosis and prognosis. [ABSTRACT FROM AUTHOR]

Background: Ninety-nine toothbrushes with hundreds of the most sought-after designs portrayed in full color. Both past and presently available toothbrushes with different bristle design claim to have a beneficial effect in the prevention of dental plaque. What role does the bristle design have in reducing plaque, which is considered to be a direct marker for the cariogenic activity, is attempted. Aims and Objective: An attempt to * Compare the plaque reduction by four different manual toothbrushes bristle designs. * Explore the mechanics of toothbrush bristle designing. Materials and Methods: The study was examiner blind cross-over design assessing the plaque removal efficacy of all four brushes on a single occasion. Forty subjects aged 18-25 years participated in the study. On day 1 of each test period, the subjects were rendered plaque free and were asked to suspend oral hygiene practices for 24 hours. On day 2, the subjects were scored for plaque prior to brushing using the Turesky-Gilmore modification of Quigley-Hein plaque index. The subjects then brushed with the allocated toothbrush for 2 minutes and the post-brushing plaque scores were assessed. Statistical Analysis: Paired t-test, ANOVA and Unpaired t-test. Results: All the brushes showed a significant reduction in the post-brushing plaque scores (P < 0.001) and mean reduction in the plaque scores for all the brushes was around 71%. Conclusion: The data derived from the study supports the contention of many researchers that there is no single superior design of manual toothbrush. [ABSTRACT FROM AUTHOR]