Search

Ensuring the security of picture data on a network presents considerable difficulties because of the requirement for conventional embedding systems, which ultimately leads to subpar performance. It poses a risk of unauthorized data acquisition and misuse. Moreover, the previous image security-based techniques faced several challenges, including high execution times. As a result, a novel framework called Graph Convolutional-Based Twofish Security (GCbTS) was introduced to secure the images used in healthcare. The medical data are gathered from the Kaggle site and included in the proposed architecture. Preprocessing is performed on the data inserted to remove noise, and the hash 1 value is computed. Using the generated key, these separated images are put through the encryption process to encrypt what they contain. Additionally, to verify the user's identity, the encrypted data calculates the hash 2 values contrasted alongside the hash 1 value. Following completion of the verification procedure, the data are restored to their original condition and made accessible to authorized individuals by decrypting them with the collective key. Additionally, to determine the effectiveness, the calculated results of the suggested model are connected to the operational copy, which depends on picture privacy.

Progress made by the medical community in increasing lifespans comes with the costs of increasing the incidence and prevalence of age-related diseases, neurodegenerative ones included. Aging is associated with a series of morphological changes at the tissue and cellular levels in the brain, as well as impairments in signaling pathways and gene transcription, which lead to synaptic dysfunction and cognitive decline. Although we are not able to pinpoint the exact differences between healthy aging and neurodegeneration, research increasingly highlights the involvement of neuroinflammation and chronic systemic inflammation (inflammaging) in the development of age-associated impairments via a series of pathogenic cascades, triggered by dysfunctions of the circadian clock, gut dysbiosis, immunosenescence, or impaired cholinergic signaling. In addition, gender differences in the susceptibility and course of neurodegeneration that appear to be mediated by glial cells emphasize the need for future research in this area and an individualized therapeutic approach. Although rejuvenation research is still in its very early infancy, accumulated knowledge on the various signaling pathways involved in promoting cellular senescence opens the perspective of interfering with these pathways and preventing or delaying senescence.

Creutzfeldt-Jakob disease is a rare neurodegenerative and invariably fatal disease with a fulminant course once the first clinical symptoms emerge. Its incidence appears to be rising, although the increasing figures may be related to the improved diagnostic tools. Due to the highly variable clinical picture at onset, many specialty physicians should be aware of this disease and refer the patient to a neurologist for complete evaluation. The diagnostic criteria have been changed based on the considerable progress made in research on the pathogenesis and on the identification of reliable biomarkers. Moreover, accumulated knowledge on pathogenesis led to the identification of a series of possible therapeutic targets, although, given the low incidence and very rapid course, the evaluation of safety and efficacy of these therapeutic strategies is challenging.

Graphitic carbon nitride (g-C 3 N 4 ) as a novel heterogeneous catalyst is employed for the visible light-mediated synthesis of the imidazo[1,5- a ]pyridines via the oxidative amination of C-H bond at room temperature without the need for any additional solvent. Extensive characterization of the catalyst was performed using techniques such as FT-IR, PXRD, TGA, SEM and EDX analysis. The optimized conditions enabled the successful and expeditious conversion of a wide range of substrates to imidazo[1,5- a ]pyridines in good yields; a notable advantage of this catalyst being recyclability, as it can be reused for up to five cycles without significant loss of activity. This feature makes it suitable for gram-scale synthesis of imidazo[1,5- a ]pyridines. Additionally, this approach offers several benefits from a green chemistry perspective as affirmed by its favorable green chemistry metrics (GCM), including low process mass intensity (PMI), low E-factor, high atom economy (AE), and good reaction mass efficiency (RME) relative to existing protocols. In addition, chemical yield (CY), mass intensity (MI), mass productivity (MP) and optimum efficiency were also calculated. This environmentally friendly method offers multiple advantages and represents a significant advancement in the synthesis of imidazo[1,5- a ]pyridines.

Deaths from lung cancer are mostly caused by smoking. Cough, dyspnea, fatigue, weight loss, and Horner's syndrome are among the symptoms. Non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) are the two categories into which lung cancer may be divided. Because of its effectiveness and lower death rates, lobectomy is the primary line of therapy for benign and early-stage lung illnesses. Pulmonary rehabilitation is a routine treatment for thoracic surgery individuals who are at a high risk to improve functional ability, avoid postoperative deterioration, avoid postoperative deterioration, and reduce complications and even hospital stays. Pulmonary rehabilitation is a multifaceted continuum of services intended to help individuals with pulmonary disease and their families reach and sustain their highest possible degree of independence and community functioning, typically provided by an interdisciplinary team of specialists.  The objective of this research was to gather preliminary information and assess the effects of pre-rehabilitation on those suffering from lung cancer and having lobectomy. The pre-rehabilitation program's outcomes include increased lung functional capacity, enhanced quality of life, patient independence in daily living activities, and a shorter hospital stay. Gradually increasing walking distance over time can build endurance, requiring consistency, pacing, proper hydration, nutrition, and regular breaks. This review analyzed the effect of pre-rehabilitation in lung cancer patients undergoing lobectomy. Pre-rehabilitation program for individuals with lung cancer improves both preoperative and postoperative health through various exercises. Pulmonary rehabilitation is a multidisciplinary approach that encourages physical activity, learning about disease, treatment options, and coping mechanisms. Instead of curing the illness, its goal is to lessen its symptoms and limitations. Patients with pulmonary diseases or undergoing thoracic surgery prefer pre-rehabilitation programs due to their non-traumatic nature and fewer resources required. Elastic resistance band exercises are beneficial for lung cancer patients' pre-rehabilitation by strengthening and stretching muscle groups, improving exercise capacity, and supporting white blood cell counts. These exercises can be customized to individual needs, making them a safe and effective addition to a patient's exercise routine. They have to be carried out at least three days a week. Pulmonary exercise, including the use of a tri-ball pulmonary exerciser or three-ball spirometer, can improve lung function, respiratory muscle strength, and exercise capacity in lung cancer patients. It involves breathing techniques, cough exercises, and inflating a balloon. Pulmonary rehabilitation has a positive impact on patient health. Improved lung vital capacity, shorter hospital stays, and fewer problems following surgery are all achieved with pulmonary rehabilitation. The pre-rehabilitation plan allows the patient to resume their daily routines., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Sharma et al.)

Background and Aims: Intra-articular steroids provide significant pain relief in sacroiliac joint pain (SIJP), but their action is short-lived. Cryoneurolysis is reported to produce prolonged pain relief in various pain conditions. However, its efficacy has not been evaluated in patients with SIJP. Thus, we compared the efficacy of cryoneurolysis with steroid injections in adult patients with SIJP., Methods: This retrospective healthcare records review-based study involved 83 patients with SIJP. Patients were divided into two groups: cases (sacroiliac joint [SIJ] cryoneurolysis, n = 39) and controls (SIJ steroid injection, n = 44). An 11-point numeric pain rating scale (NPRS) was used to assess the pain severity at baseline and immediately, 1, 3 and 6 months post-intervention. A reduction of ≥50% in NPRS score immediately following SIJ cryoneurolysis and steroid injection was considered a successful outcome. The difference between the treatment groups was assessed with a Chi-square test, and P < 0.05 was considered statistically significant., Results: Both cases and controls showed significantly decreased NPRS scores from baseline to immediately, 1 month, 3 months and 6 months postintervention ( P < 0.001). However, compared to controls, cases had significantly lower NPRS scores at all time points (all P < 0.001). Moreover, a significantly greater proportion of cases had ≥50% decrease in NPRS score from baseline, that is, 1 month (97.44% vs. 75%, P = 0.004), 3 months (100% vs. 47.73%, P < 0.001) and 6 months (69.23% vs. 27.27%, P < 0.001)., Conclusion: Although both cryoneurolysis and intra-articular steroid injections provide significant pain relief immediately, 1, 3 and 6 months postintervention, cryoneurolysis resulted in significantly greater pain relief., Competing Interests: There are no conflicts of interest., (Copyright: © 2023 Indian Journal of Anaesthesia.)

Diabetic kidney disease (DKD) can lead to end-stage kidney disease (ESKD) and mortality; however, few mechanistic biomarkers are available for high-risk patients, especially those without macroalbuminuria. Urine from participants with diabetes from the Chronic Renal Insufficiency Cohort (CRIC) study, the Singapore Study of Macro-angiopathy and Micro-vascular Reactivity in Type 2 Diabetes (SMART2D), and the American Indian Study determined whether urine adenine/creatinine ratio (UAdCR) could be a mechanistic biomarker for ESKD. ESKD and mortality were associated with the highest UAdCR tertile in the CRIC study and SMART2D. ESKD was associated with the highest UAdCR tertile in patients without macroalbuminuria in the CRIC study, SMART2D, and the American Indian study. Empagliflozin lowered UAdCR in nonmacroalbuminuric participants. Spatial metabolomics localized adenine to kidney pathology, and single-cell transcriptomics identified ribonucleoprotein biogenesis as a top pathway in proximal tubules of patients without macroalbuminuria, implicating mTOR. Adenine stimulated matrix in tubular cells via mTOR and stimulated mTOR in mouse kidneys. A specific inhibitor of adenine production was found to reduce kidney hypertrophy and kidney injury in diabetic mice. We propose that endogenous adenine may be a causative factor in DKD.

The newly symmetrical liquid crystalline compounds (CPB 1 -CPB 4 ) based on calix[4]pyrrole as central rigid core are synthesized via esterification reaction. All the four functionalized compounds exhibit columnar hexagonal phase (Col h ) over a higher mesophase temperature range and further stabilized mesophase upto room temperature. The thermal behavior and optical texture are identified by using differential scanning calorimetry (DSC), Polarizing optical microscopy (POM) while the molecular organization of compound in mesogenic state by X-ray diffraction technique. The molecular system based on calix[4]pyrrole core with symmetrical nature exhibited columnar type self-assembly at room temperature. All these four supramolecules with different side spacer show higher thermal stability. Based upon the optimization, compound CPB 2 has been further tested to implicate as optical window layer in thin films solar cell devices. The calix[4]pyrrole functionalized supramolecular liquid crystalline compound based thin films showed suitable transmittance, optical energy band gap together with absorbance and extinction coefficient. The linear dependence of current on the voltage demonstrated Ohmic behavior of the CPB 2 films. The surface morphology to the developed samples designated nearly uniform deposition of the CPB 2 thin films together with grain growth. The findings warrant suitability of the films to implicate these as an eco-friendly optical window layer in thin films based solar cells., (© 2023 Wiley-VCH GmbH.)

Four new azo-based supramolecular materials containing thiacalixarene core substituted by variable alkoxy groups (TFA 1 -TFA 4 ) have been designed and synthesized for the mesomorphic and photoswitching properties. The liquid crystalline behavior were accomplished by using DSC, POM, and XRD studies. All azo-based thiacalixarene based materials with short and higher chain length display columnar hexagonal mesophase with broad temperature range. The thermal behavior of all the materials was investigated by DSC and TGA study. The structural and conformational study of the lower rim functionalized materials was confirmed by using different techniques. These thiacalixarene moulded liquid crystalline compounds shows columnar self-assembly type behavior and higher thermal stability. The introduction of bi-substituted azo-ester network towards the lower rim of thiacalixarene core has impact on the electron delocalization and liquid crystalline properties. The photoswitching properties suggested cis and trans azo-isomerization under radiation of UV light and higher thermal back relaxation time. The mesogenic behaviour of compound TFA 2 and TFA 4 were demolished by the influence of cis and trans isomerization. The structure-property correlation is studied to understand the variation in mesogenic properties with the substitution of variable alkoxy side chain., (© 2023 Wiley-VCH GmbH.)

In the present work, an attempt has been made to study the influence of process parameters of the wire electric discharge machining (WEDM) process on the machining characteristics. The commercially pure titanium is machined by WEDM using brass wire as an electrode. The input parameters in this work were pulse on-time (A on ), pulse off-time (A off ), servo voltage (SV) and wire tension (WT). On the other hand, dimensional accuracy (DA), average surface roughness (R a ) and maximum surface roughness (R z ) were chosen as the response parameters. The empirical relations developed for response characteristics were solved collectively using Evaluation Based on Distance from Average Solution (EDAS) and Particle Swarm Optimization (PSO). The optimized setting for minimizing the surface irregularities while machining titanium alloy on WEDM is predicted as A on : 8 μs; A off : 13 μs; SV: 45 V; and WT: 8 N. Moreover, the predicted solution at the optimized parametric settings came out as DA: 95%; Ra: 3.163 μm; Rz: 22.99 μm; WL: 0.0182 g; and DR: 0.1277 mm. The validation experiments at the optimized setting showed the close agreement between predicted and experimental values. The morphological study by scanning electron microscopy (SEM) at the optimized setting revealed a significant reduction in surface defects such as micro cracks, micro cavities, globules and sub-surfaces, etc. In a nutshell, the study justified the effectiveness of EDAS-PSO in efficiently predicting the results for machining of pure titanium (Grade 2) using the WEDM process.

Liquid crystals are considered to be the fourth state of matter with an intermediate order and fluidity in comparison to solids and liquids. Calixarenes are among one of the most versatile families of building blocks for supramolecular chemistry due to their unique vaselike structure that can be chemically engineered to have different shapes and sizes. During the last few decades, calixarenes have drawn much attention in the field of supramolecular chemistry due to their diverse applications in the fields of ion and molecular recognition, ion-selective electrodes for catalysis, drug delivery, gelation, organic electronics and sensors, etc. Imbuing liquid crystallinity to the calixarene framework leads to functionalized calixarene derivatives with fluidity and order. Columnar self-assembly of such derivatives in particular enhance the charge migration along the column due to the 1D stacking due to the enhanced π-π overlap. Considering limited reports and reviews on this new class of calixarene based liquid crystals, a comprehensive account of the synthesis of calixarene liquid crystals along with their mesomorphic behavior and potential applications are presented in this review., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

A reliable and robust bioanalytical method was developed to quantify neratinib, a tyrosine kinase inhibitor in human plasma, using UPLC-MS/MS. The extraction of neratinib and its deuterated internal standard, neratinib-d6, was successfully performed on hybrid solid-phase extraction ultra-cartridges to remove the interference of phospholipids and proteins. Chromatographic analysis was performed on a UPLC BEH C18 (50 × 2.1 mm, 1.7 μm) column using 0.1% formic acid and acetonitrile under gradient conditions. The total analysis time was 1.5 min. Neratinib was quantified using electrospray ionization source operated in the positive-ion multiple reaction monitoring mode. The mass transitions of neratinib and neratinib-d6 were m/z 557.3/112.1 and m/z 563.1/118.2, respectively. The linear concentration range for neratinib was 0.5-500 ng/mL, which adequately covers concentration levels expected in real subject samples. The assay was extensively validated for various validation parameters following standard guidelines for a bioanalytical assay. The intra- and inter-batch precision was ≤4.6%, and neratinib was found to be stable under various stability conditions. The mean internal standard-normalized matrix factor and recovery were 0.997 and 95.4%, respectively. The validated method was successfully applied to a pharmacokinetic study in healthy subjects with different doses., (© 2022 John Wiley & Sons Ltd.)

In molecular biology, it is a general assumption that the ensemble of expressed molecules, their activities and interactions determine biological function, cellular states and phenotypes. Stable protein complexes-or macromolecular machines-are, in turn, the key functional entities mediating and modulating most biological processes. Although identifying protein complexes and their subunit composition can now be done inexpensively and at scale, determining their function remains challenging and labor intensive. This study describes Protein Complex Function predictor (PCfun), the first computational framework for the systematic annotation of protein complex functions using Gene Ontology (GO) terms. PCfun is built upon a word embedding using natural language processing techniques based on 1 million open access PubMed Central articles. Specifically, PCfun leverages two approaches for accurately identifying protein complex function, including: (i) an unsupervised approach that obtains the nearest neighbor (NN) GO term word vectors for a protein complex query vector and (ii) a supervised approach using Random Forest (RF) models trained specifically for recovering the GO terms of protein complex queries described in the CORUM protein complex database. PCfun consolidates both approaches by performing a hypergeometric statistical test to enrich the top NN GO terms within the child terms of the GO terms predicted by the RF models. The documentation and implementation of the PCfun package are available at https://github.com/sharmavaruns/PCfun. We anticipate that PCfun will serve as a useful tool and novel paradigm for the large-scale characterization of protein complex function., (© The Author(s) 2022. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Advancements in mass spectrometry-based proteomics have enabled experiments encompassing hundreds of samples. While these large sample sets deliver much-needed statistical power, handling them introduces technical variability known as batch effects. Here, we present a step-by-step protocol for the assessment, normalization, and batch correction of proteomic data. We review established methodologies from related fields and describe solutions specific to proteomic challenges, such as ion intensity drift and missing values in quantitative feature matrices. Finally, we compile a set of techniques that enable control of batch effect adjustment quality. We provide an R package, "proBatch", containing functions required for each step of the protocol. We demonstrate the utility of this methodology on five proteomic datasets each encompassing hundreds of samples and consisting of multiple experimental designs. In conclusion, we provide guidelines and tools to make the extraction of true biological signal from large proteomic studies more robust and transparent, ultimately facilitating reliable and reproducible research in clinical proteomics and systems biology., (© 2021 The Authors. Published under the terms of the CC BY 4.0 license.)

Previous studies have described the clinical, serological and pathological features of patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and antibodies directed against the paranodal proteins neurofascin-155, contactin-1 (CNTN1), contactin-associated protein-1 (Caspr1), or nodal forms of neurofascin. Such antibodies are useful for diagnosis and potentially treatment selection. However, antibodies targeting Caspr1 only or the Caspr1/CNTN1 complex have been reported in few patients with CIDP. Moreover, it is unclear if these patients belong to the same pathophysiological subgroup. Using cell-based assays in routine clinical testing, we identified sera from patients with CIDP showing strong membrane reactivity when both CNTN1 and Caspr1 were co-transfected (but not when CNTN1 was transfected alone). Fifteen patients (10 male; aged between 40 and 75) with antibodies targeting Caspr1/CNTN1 co-transfected cells were enrolled for characterization. The prevalence of anti-Caspr1/CNTN1 antibodies was 1.9% (1/52) in the Sant Pau CIDP cohort, and 4.3% (1/23) in a German cohort of acute-onset CIDP. All patients fulfilled European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) definite diagnostic criteria for CIDP. Seven (47%) were initially diagnosed with Guillain-Barré syndrome due to an acute-subacute onset. Six (40%) patients had cranial nerve involvement, eight (53%) reported neuropathic pain and 12 (80%) ataxia. Axonal involvement and acute denervation were frequent in electrophysiological studies. Complete response to intravenous immunoglobulin was not observed, while most (90%) responded well to rituximab. Enzyme-linked immunosorbent assay (ELISA) and teased nerve fibre immunohistochemistry confirmed reactivity against the paranodal Caspr1/CNTN1 complex. Weaker reactivity against Caspr1 transfected alone was also detected in 10/15 (67%). Sera from 13 of these patients were available for testing by ELISA. All 13 samples reacted against Caspr1 by ELISA and this reactivity was enhanced when CNTN1 was added to the Caspr1 ELISA. IgG subclasses were also investigated by ELISA. IgG4 was the predominant subclass in 10 patients, while IgG3 was predominant in other three patients. In conclusion, patients with antibodies to the Caspr1/CNTN1 complex display similar serological and clinical features and constitute a single subgroup within the CIDP syndrome. These antibodies likely target Caspr1 primarily and are detected with Caspr1-only ELISA, but reactivity is optimal when CNTN1 is added to Caspr1 in cell-based assays and ELISA., (© The Author(s) (2021). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Being one of the most important staple crops of the world, rice has played a vital role in slaking the calorie requirements of the masses in all the inhabitable continents of our planet. Regardless of this fact, there are many environmental concerns related to the rice production systems across the globe. One of the major worries is the emission of lethal greenhouse gases as a result of the different steps and procedures concerned with rice production and their contribution towards global warming. This study presents the status quo of the rice straw burning practice across the globe. It focuses on the greenhouse gas emissions as a result of the open field burning of rice residues and its direct effect on the environment, eventually contributing towards climate change. The study evidently shortlists the most profound regions contributing towards the open burning dilemma and the socio-political reasons associated with it. The study additionally discusses the different alternatives to straw burning with a clear-cut motive of throwing light on the opportunities that lie in the efficacious and sustainable utilization of homogeneous agricultural wastes. Different in-field straw management techniques related to the farmers and off-field methods related to the industry have been discussed. Predicated upon a survey of the life cycle assessment (LCA) studies across the globe, it is concluded that soil incorporation and electricity generation are the most environment friendly alternatives with an enormous scope of improvement in the coming future.

Background: The study aims at identifying features predictive of early onset of dementia in Parkinson's disease (PD)., Methods: 103 non-demented PD patients were evaluated on various scales at baseline and 89 patients at 3-year follow-up., Results: By the end of the study 43.8% of patients developed dementia. The development of dementia was linked to the baseline Mini Mental State Examination score (Pearson coefficient r = .404, p = 0.013), the presence of autonomic dysfunctions (r = -.621, p < 0.001) and insomnia (r = -.526, p = 0.001). A binary logistic regression analysis showed that the development of dementia was correlated strongly with the presence of autonomic dysfunctions (95% CI 2.60 to 52.83, p < 0.001), and insomnia (95% CI 0.60 to 0.95, p = 0.017)., Conclusion: Patients with signs of autonomic dysfunction and insomnia are at higher risk for developing dementia and deserve closer monitoring of cognitive symptoms.

Background: Determining a suitable dose of intravenous colistimethate is challenging because of complicated pharmacokinetics, confusing terminology, and the potential for renal toxicity. Only recently have reliable pharmacokinetic/pharmacodynamic data and dosing recommendations for intravenous colistimethate become available., Objective: The aim of this work was to develop a clinician-friendly, easy-to-use mobile app incorporating up-to-date dosing recommendations for intravenous colistimethate in critically ill adult patients., Methods: Swift programming language and common libraries were used for the development of an app, ColistinDose, on the iPhone operating system (iOS; Apple Inc). The compatibility among different iOS versions and mobile devices was validated. Dosing calculations were based on equations developed in our recent population pharmacokinetic study. Recommended doses generated by the app were validated by comparison against doses calculated manually using the appropriate equations., Results: ColistinDose provides 3 major functionalities, namely (1) calculation of a loading dose, (2) calculation of a daily dose based on the renal function of the patient (including differing types of renal replacement therapies), and (3) retrieval of historical calculation results. It is freely available at the Apple App Store for iOS (version 9 and above). Calculated doses accurately reflected doses recommended in patients with varying degrees of renal function based on the published equations. ColistinDose performs calculations on a local mobile device (iPhone or iPad) without the need for an internet connection., Conclusions: With its user-friendly interface, ColistinDose provides an accurate and easy-to-use tool for clinicians to calculate dosage regimens of intravenous colistimethate in critically ill patients with varying degrees of renal function. It has significant potential to avoid the prescribing errors and patient safety issues that currently confound the clinical use of colistimethate, thereby optimizing patient treatment., (©Xueliang Hua, Chen Li, Jason M Pogue, Varun S Sharma, Ilias Karaiskos, Keith S Kaye, Brian T Tsuji, Phillip J Bergen, Yan Zhu, Jiangning Song, Jian Li. Originally published in JMIR mHealth and uHealth (http://mhealth.jmir.org), 16.12.2020.)

A practical, sensitive, and robust UPLC-MS/MS method was developed and validated to quantify lacosamide in human plasma. A simple one-step protein precipitation was used to extract lacosamide and labeled lacosamide-13C, D3 as an internal standard (IS) from 150-μL plasma. The extracts were analyzed on an Eclipse Plus C18 column (50 × 2.1 mm, 1.8 μm) using 0.1% formic acid in water and methanol:acetonitrile (50:50, v/v) under gradient conditions. The extracts were quantified on LCMS-8040 using electrospray ionization source operated in positive ionization and multiple reaction monitoring modes. The method showed good linearity from 0.02 to 20 μg/mL, which was adequate to cover lacosamide concentration assayed in formulations with different strengths. The bioanalytical assay was fully validated as per current regulatory guidelines. The intra-batch and inter-batch precision values of lacosamide were less than 4.6%. Lacosamide was found to be stable at different storage conditions. The extraction recoveries and IS-normalized matrix factors for lacosamide ranged from 97.17 to 99.68% and from 0.973 to 1.012, respectively. The validated method was successfully applied to a pharmacokinetic study with three lacosamide formulations (50, 100, and 200 mg) in 36 healthy subjects. The assay reliability was determined by reanalysis of 81 subject samples., (© 2020 John Wiley & Sons, Ltd.)

The poor fatigue strength of Ti-6Al-4V ELI is a main cause of failure in structural implants. In this work, Ti-6Al-4V ELI was subjected to β-solution treatment to obtain martensite microstructure and further subjected to -196 °C for 24 h. Significant improvement in high cycle fatigue performance of martensite Ti-6Al-4V ELI was observed on exposure to cryogenic cycle. Resistance to fatigue crack growth of alloy was augmented in martensite structure as compared with mill annealed sample and the same was retained even after exposure to cryogenic treatment. The variation observed in fatigue behavior due to cryogenic treatment was correlated with fractography and metallurgical investigations. Improvement in high cycle fatigue performance can be attributed to a combined effect of a decrease in the size of prior β grain, formation of massive α patch and its subsequent transformation into ultra-fine α and β during the soaking period at -196 °C., Competing Interests: The authors declare no conflict of interest.

A rapid, simple and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method has been developed to quantify fenoprofen, a nonsteroidal anti-inflammatory drug in human plasma for a pharmacokinetic study in healthy subjects. Owing to high levels of protein binding, protein precipitation followed by solid-phase extraction was employed for the extraction of fenoprofen and fenoprofen-d3 (used as internal standard) from 200 μL human plasma. Separation was performed on a BEH C 18 (50 × 2.1 mm, 1.7 μm) column using methanol-0.2% acetic acid in water (75:25, v/v) under isocratic elution. Electrospray ionization was operated in the negative mode for sample ionization. Ion transitions used for quantification in the selected reaction monitoring mode were m/z 241/197 and m/z 244/200 for fenoprofen and fenoprofen-d3, respectively. Under the optimized conditions, fenoprofen showed excellent linearity in the concentration range 0.02-20 μg/mL (r 2  ≥ 0.9996), adequate sensitivity, favorable accuracy (96.4-103.7%) and precision (percentage coefficient of variation ≤4.3) with negligible matrix effect. The validated method was successfully applied to a pharmacokinetic study of fenoprofen in healthy subjects. The significant features of the method include higher sensitivity, small plasma volume for processing and a short analysis time., (© 2019 John Wiley & Sons, Ltd.)

Background: S-sulphenylation is a ubiquitous protein post-translational modification (PTM) where an S-hydroxyl (-SOH) bond is formed via the reversible oxidation on the Sulfhydryl group of cysteine (C). Recent experimental studies have revealed that S-sulphenylation plays critical roles in many biological functions, such as protein regulation and cell signaling. State-of-the-art bioinformatic advances have facilitated high-throughput in silico screening of protein S-sulphenylation sites, thereby significantly reducing the time and labour costs traditionally required for the experimental investigation of S-sulphenylation., Results: In this study, we have proposed a novel hybrid computational framework, termed SIMLIN, for accurate prediction of protein S-sulphenylation sites using a multi-stage neural-network based ensemble-learning model integrating both protein sequence derived and protein structural features. Benchmarking experiments against the current state-of-the-art predictors for S-sulphenylation demonstrated that SIMLIN delivered competitive prediction performance. The empirical studies on the independent testing dataset demonstrated that SIMLIN achieved 88.0% prediction accuracy and an AUC score of 0.82, which outperforms currently existing methods., Conclusions: In summary, SIMLIN predicts human S-sulphenylation sites with high accuracy thereby facilitating biological hypothesis generation and experimental validation. The web server, datasets, and online instructions are freely available at http://simlin.erc.monash.edu/ for academic purposes.

A new class of blue light-emitting bowl-shaped mesogens with the thiacalix[4]arene core appended with 1,3,4-thiadiazole derivatives having peripheral alkoxy side chains have been synthesized and well characterized. The liquid crystalline behavior of present synthesized derivatives was examined by optical polarizing microscopy, differential scanning calorimetry, and X-ray diffraction studies. It was observed that these thiacalix[4]arene derivatives were capable of stabilizing the observed Col h phase with a higher temperature range. The cone-shaped thiacalix[4]arene-based liquid crystals with peripheral alkoxy side chains able to pack into the columns with enriched intermolecular interactions and thermal behavior. All derivatives showed blue luminescence in solution, solid thin-film, and gelation state. The hexagonal columnar phase and emissive nature of thiadiazole-based thiacalixarene compounds having xerogel behavior make them favorable in the application of emissive electronic display devices. The electrochemical properties of these thiacalixarene-based compounds demonstrate the effect of alkyl side chain on the highest occupied molecular orbital-lowest unoccupied molecular orbital energy levels and also exhibited lower electron band gaps. The electroluminescence behavior of the compound 10c was examined as emissive layers in the fabrication of organic light-emitting diodes., Competing Interests: The authors declare no competing financial interest., (Copyright © 2019 American Chemical Society.)

Context: Migraine is the second most common headache disorder. However, prophylactic therapy remains underutilized., Aims: The objective of the study was to compare the efficacy and safety of low-dose sodium valproate and low-dose propranolol sustained release (SR) in the prophylaxis of common migraine headache., Settings and Design: The study was conducted in a tertiary care teaching institute. It was a randomized, prospective, parallel, open-label, clinical study., Subjects and Methods: The study included 60 patients with common migraine headaches (≥2 attacks/month) treated for 12 weeks. The patients were randomly divided into two treatment groups treated by sodium valproate 500 mg/day and propranolol SR 40 mg/day, respectively. The primary outcome measures were the percentage of responders (i.e., >50% decrease in mean headache frequency) at the end of 12 weeks and decrease in mean headache frequency (per 4 weeks) at the end of 12 weeks. The patients were assessed at 0, 4, 8, and 12 weeks of the study., Statistical Analysis Used: Intention-to-treat analysis was used for all the statistical analysis., Results: Fifty-five patients completed the study. At the end of the treatment, both sodium valproate and propranolol caused a significant ( P < 0.0001) reduction in frequency, severity, and duration of migraine headache. Propranolol caused significantly greater reduction in the severity of headache ( P = 0.0410) than sodium valproate. The percentage of responders was 60% in sodium valproate group and 70% in propranolol group. Drowsiness was the most common adverse effect noted in both the groups., Conclusion: Both sodium valproate and propranolol significantly reduced frequency, severity, and duration of migraine headache, but propranolol caused significantly greater reduction in the severity of headache compared to sodium valproate. Both the medications were well tolerated and did not result in discontinuation., Competing Interests: There are no conflicts of interest., (Copyright: © 2019 Indian Journal of Pharmacology.)

Environmental protection is the major concern of any form of manufacturing industry today. As focus has shifted towards sustainable cooling strategies, minimum quantity lubrication (MQL) has proven its usefulness. The current survey intends to make the MQL strategy more effective while improving its performance. A Ranque⁻Hilsch vortex tube (RHVT) was implemented into the MQL process in order to enhance the performance of the manufacturing process. The RHVT is a device that allows for separating the hot and cold air within the compressed air flows that come tangentially into the vortex chamber through the inlet nozzles. Turning tests with a unique combination of cooling technique were performed on titanium (Grade 2), where the effectiveness of the RHVT was evaluated. The surface quality measurements, forces values, and tool wear were carefully investigated. A combination of analysis of variance (ANOVA) and evolutionary techniques (particle swarm optimization (PSO), bacteria foraging optimization (BFO), and teaching learning-based optimization (TLBO)) was brought into use in order to analyze the influence of the process parameters. In the end, an appropriate correlation between PSO, BFO, and TLBO was investigated. It was shown that RHVT improved the results by nearly 15% for all of the responses, while the TLBO technique was found to be the best optimization technique, with an average time of 1.09 s and a success rate of 90%., Competing Interests: The authors declare no conflict of interest.

Objective: To develop a microwell suspension platform for the adaption of attached stem cell differentiation protocols into mixed suspension culture., Results: We adapted an adherent protocol for the retinal differentiation of human induced pluripotent stem cells (hiPSCs) using a two-step protocol. Establishing the optimum embryoid body (EB) starting size and shaking speed resulted in the translation of the original adherent process into suspension culture. Embryoid bodies expanded in size as the culture progressed resulting in the expression of characteristic markers of early (Rx, Six and Otx2) and late (Crx, Nrl and Rhodopsin) retinal differentiation. The new process also eliminated the use of matrigel, an animal-derived extracellular matrix coating., Conclusions: Shaking microwells offer a fast and cost-effective method for proof-of-concept studies to establish whether pluripotent stem cell differentiation processes can be translated into mixed suspension culture.

Background: Current literature suggests that preserving the lobular branch of the great auricular nerve has greater impact on sensory function of the auricle than preservation of the posterior branch during rhytidectomy. However, no methodology exists to efficiently and accurately determine the topographic location of the lobular branch. This study describes the branching characteristics of the lobular branch and algorithmic surface markings to assist surgeons in preservation of the great auricular nerve during rhytidectomy flap elevation., Methods: The lobular branch was dissected in 50 cadaveric necks. Measurements were taken from the lobular branch to conchal cartilage, tragus, and antitragus. The anterior branch was measured to its superficial musculoaponeurotic system insertion, and the posterior branch was measured to the mastoid process. The McKinney point was marked and the great auricular nerve diameter was recorded. Branching pattern and location of branches within the Ozturk 30-degree angle were documented. Basic statistics were performed., Results: The lobular branch was present in all specimens and distributed to three regions. In 85 percent of specimens, the lobular branch resided directly inferior to the antitragus; in the remaining specimens, it was located directly inferior to the tragus. Preoperative markings consisting of two vertical lines from the tragus and antitragus to the McKinney point can be used to outline the predicted location of the lobular branch., Conclusions: This study delineates the location of the lobular branch of the great auricular nerve. The authors translate these findings into a quick and simple intraoperative marking, which can assist surgeons in avoiding lobular branch injury during rhytidectomy dissection.

Giant cell tumour (GCT) is an uncommon primary bone tumour, and its multicentric presentation is exceedingly rare. We report a case of a 45-year-old female who presented to us with GCT of left distal radius. On the skeletal survey, osteolytic lesion was noted in her right sacral ala. Biopsy confirmed both lesions as GCT. Pulmonary metastasis was also present. Resection-reconstruction arthroplasty for distal radius and thorough curettage and bone grafting of the sacral lesion were done. Multicentric GCT involving distal radius and sacrum with primary sacral involvement is not reported so far to our knowledge.

Ind1, a mitochondrial P-loop NTPase is essential for assembly of respiratory complex-I. Respiratory complex-I (NADH: ubiquinone oxidoreductase), a large (mitochondrial inner membrane) enzyme, is made of 45 subunits and 8 iron-sulfur clusters. Ind1, an iron-sulfur cluster protein involved in the maturation of respiratory complex and binds an Fe/S cluster via a conserved CXXC motif in a labile way. Ind1 has been proposed as a specialized biogenesis factor involved in delivering the Fe/S clusters to the apo complex-I subunits. The IND1 gene is conserved in eukaryotes and is present in genomes of the species that retain functional respiratory complex-I. Depletion of human Ind1 causes ultra-structural changes in depleted mitochondria, including the loss of cristae membranes, massive remodeling of respiratory super complexes, and increased lactate production. Ind1 sequence bears known nucleotide binding domain motifs and was first classified as Nucleotide Binding Protein-Like (NUBPL). Despite the obvious importance of Ind1, very little is known about this protein; in particular its structure as well as its Fe/S cluster binding properties. In the present work we show that the expression of native huInd1 in Escherichia coli stimulates over-expression of the beta-lactamase TEM-1 from E. coli. The homology modeling of huInd1 shows hallmark of Rossmann fold, where a central beta sheet is covered by helices on either side. In the light of the modeled structure of huInd1, we hypothesize that huInd1 binds to the untranslated region (UTR) of the TEM-1 mRNA at 3' site and thereby reducing the possibility of its endonucleolytic cleavage, resulting in over-expression of TEM-1., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Objective: To compare plain soap, alcohol hand rub and iodophors as hand hygiene measures in a neonatal intensive care unit (NICU)., Design: Randomized, crossover, three-armed, controlled trial with blinded outcome measurement., Setting: Level III NICU., Participants: 35 NICU nurses., Intervention: Participants were assigned to plain soap hand washing, alcohol hand rub and povidone-iodine hand scrub by a random cross-over design. Interventions were preceded by 14-day neutral periods. Cultures from hands were taken before and after each hand-hygiene use, prior to 5 patient-care activities., Main Outcome Measure: The primary outcome was mean post-hygiene colony forming unit count (CFU-C)., Results: There were differences between soap, alcohol and povidone groups vis a vis posthygiene CFUC [median: 60, 8 and 10.5, respectively (P<0.001)], absolute reduction in CFU-C [median: 15, 100 and 40, respectively (P<0.001)], percent reduction in CFUC [median: 33.3, 92 and 87, respectively (P<0.001)] and proportion with low CFU-C [47%, 71% and 72%, respectively (P<0.001)]. Alcohol [Adjusted OR 3.2 (95% CI 1.9, 5.3)], povidone-iodine [AOR 3.1 (95% CI 1.8, 5.3)] and high prehygiene CFU-C (>300) [AOR 0.18 (95% CI 0.1, 0.3)] were independently associated with low CFU-C., Conclusion: After a 2 minute hand wash at entry into NICU, alcohol hand rub and povidone-iodine scrub are superior to plain soap hand wash for subsequent decontamination of hands of nurses working in NICU.

Study Objective: Exposure to cyanide in fires and industrial exposures and intentional cyanide poisoning by terrorists leading to mass casualties is an ongoing threat. Current treatments for cyanide poisoning must be administered intravenously, and no rapid treatment methods are available for mass casualty cyanide exposures. Cobinamide is a cobalamin (vitamin B(12)) analog with an extraordinarily high affinity for cyanide that is more water-soluble than cobalamin. We investigate the use of intramuscular cobinamide sulfite to reverse cyanide toxicity-induced physiologic changes in a sublethal cyanide exposure animal model and determine the ability of an intramuscular cobinamide sulfite injection to rapidly reverse the physiologic effects of cyanide toxicity., Methods: New Zealand white rabbits were given 10 mg sodium cyanide intravenously over 60 minutes. Quantitative diffuse optical spectroscopy and continuous-wave near-infrared spectroscopy monitoring of tissue oxyhemoglobin and deoxyhemoglobin concentrations were performed concurrently with blood cyanide level measurements and cobinamide levels. Immediately after completion of the cyanide infusion, the rabbits were injected intramuscularly with cobinamide sulfite (n=6) or inactive vehicle (controls, n=5)., Results: Intramuscular administration led to rapid mobilization of cobinamide and was extremely effective at reversing the physiologic effects of cyanide on oxyhemoglobin and within deoxyhemoglobin extraction. Recovery time to 63% of their baseline values in the central nervous system occurred within a mean of 1,032 minutes in the control group and 9 minutes in the cobinamide group, with a difference of 1,023 minutes (95% confidence interval 116 to 1,874 minutes). In muscle tissue, recovery times were 76 and 24 minutes, with a difference of 52 minutes (95% confidence interval 7 to 98 minutes). RBC cyanide levels returned toward normal significantly faster in cobinamide sulfite-treated animals than in control animals., Conclusion: Intramuscular cobinamide sulfite rapidly and effectively reverses the physiologic effects of cyanide poisoning, suggesting that a compact cyanide antidote kit can be developed for mass casualty cyanide exposures., (Copyright (c) 2009 American College of Emergency Physicians. Published by Mosby, Inc. All rights reserved.)

Our purpose is to compare cobinamide to hydroxocobalamin in reversing cyanide (CN)-induced physiologic effects in an animal model using diffuse optical spectroscopy (DOS). Cyanide poisoning is a major threat worldwide. Cobinamide is a novel molecule that can bind two molecules of cyanide, has a much higher binding affinity than hydroxocobalamin, and is more water soluble. We investigated the ability of equimolar doses of cobinamide and hydroxocobalamin to reverse the effects of cyanide exposure in an animal model monitored continuously by DOS. Cyanide toxicity was induced in 16 New Zealand white rabbits by intravenous infusion. Animals were divided into three groups: controls (n=5) received saline following cyanide, hydroxocobalamin (N=6) following cyanide, and cobinamide (N=5) following cyanide. Cobinamide caused significantly faster and more complete recovery of oxy- and deoxyhemoglobin concentrations in cyanide-exposed animals than hydroxocobalamin- or saline-treated animals, with a recovery time constant of 13.8+/-7.1 min compared to 75.4+/-25.1 and 76.4+/-42.7 min, for hydroxocobalamin- and saline-treated animals, respectively (p<0.0001). This study indicates that cobinamide more rapidly and completely reverses the physiologic effects of cyanide than equimolar doses of cobalamin at the dose used in this study, and CN effects and response can be followed noninvasively using DOS.

Some Pseudomonas aeruginosa strains are cyanogenic, and cyanide may contribute to the bacterium's virulence. Using human isolates of P. aeruginosa, we have shown that Drosophila melanogaster suspended above cyanogenic strains become motionless and develop bradycardia and that flies injected with cyanogenic bacterial strains die more rapidly than those injected with noncyanogenic strains. Flies exposed to cyanogenic strains had high cyanide and low adenosine triphosphate (ATP) concentrations in body extracts, and treatment with a cyanide antidote equalized survival of flies injected with cyanogenic and noncyanogenic strains. P. aeruginosa PAO1 strain with a mutation in the hydrogen cyanide synthase gene cluster was much less toxic to flies than the parental cyanogenic strain or 2 knock-in strains. Transgenic flies overexpressing rhodanese, which detoxifies cyanide by converting it to thiocyanate, were resistant to cyanide and the increased virulence of cyanogenic strains. We conclude that D. melanogaster is a good model for studying cyanide produced by P. aeruginosa.

There is a lack of community-based studies that have examined level and context of homosexual activity in India among male youth. As part of a larger study on sexual behavior and gender attitudes of rural youth in Northern India, this study identified a subgroup of young men who reported homosexual experiences, even though they did not identify themselves as homosexual. This article attempts to examine the levels and range of sexual practices and attitudes of the homosexually active male youth by comparing them with their peers who reported heterosexual experiences. Study findings indicate that about one-fifth of sexually active male youth reported homosexual experiences. These young men begin their sexual careers early; engage with a higher number of sexual partners, both male and female; and are more likely to report inconsistent condom use, as compared to their heterosexually active peers. With high levels of partner mixing and inconsistent condom, use it appears that, for this subgroup of young men with high risk behaviors, homosexual experiences are only one part of their sexual lives and not the main factor that would contribute to their HIV vulnerability. Interventions need to be mindful of these issues, rather than rushing into labelling youth as homosexual or heterosexual for programmatic purposes. At the same time, as high-risk behaviors are largely unexplored among a general population of rural male youth, there is need for more in-depth ethnographic and culturally specific sexuality research to explore if there is a subculture that may promote sexual practices including same-sex activities that influences HIV vulnerability.

A limited number of nitric oxide (NO)-generating drugs are available for clinical use for acute and chronic conditions. Most of these agents are organic nitrates, which do not directly release NO; tolerance to the drugs develops, in part, as a consequence of their conversion to NO. We synthesized nitrosyl-cobinamide (NO-Cbi) from cobinamide, a structural analog of cobalamin (vitamin B12). NO-Cbi is a direct NO-releasing agent that we found was stable in water, but under physiologic conditions, it released NO with a half-life of 30 mins to 1 h. We show in five different biological systems that NO-Cbi is an effective NO-releasing drug. First, in cultured rat vascular smooth muscle cells, NO-Cbi induced phosphorylation of vasodilator-stimulated phosphoprotein, a downstream target of cGMP and cGMP-dependent protein kinase. Second, in isolated Drosophila melanogaster Malpighian tubules, NO-Cbi-stimulated fluid secretion was similar to that stimulated by Deta-NONOate and a cGMP analog. Third, in isolated mouse hearts, NO-Cbi increased coronary flow much more potently than nitroglycerin. Fourth, in contracted mouse aortic rings, NO-Cbi induced relaxation, albeit to a lesser extent than sodium nitroprusside. Fifth, in intact mice, a single NO-Cbi injection rapidly reduced blood pressure, and blood pressure returned to normal after 45 mins; repeated NO-Cbi injections induced the expected fall in blood pressure. These studies indicate that NO-Cbi is a useful NO donor that can be used experimentally in the laboratory; moreover, it could be developed into a vasodilating drug for treating hypertension and potentially other diseases such as angina and congestive heart failure.

Sodium nitroprusside is used to treat hypertensive emergencies and acute heart failure. It acts by releasing nitric oxide (NO), a highly potent vasodilator, but unfortunately, for each NO molecule released, five cyanide ions are released. Thus, nitroprusside therapy is limited by cyanide toxicity. Therefore, a cyanide scavenger could be beneficial when administering nitroprusside. Hydroxocobalamin, which has a relatively high binding affinity for cyanide, has been shown to reduce cyanide levels in nitroprusside-treated patients. Cobinamide, the penultimate precursor in hydroxocobalamin biosynthesis, has a much greater affinity for cyanide than cobalamin, and binds two cyanide ions. We now show that cobinamide is highly effective in neutralizing cyanide ions released by nitroprusside in cultured mammalian cells, Drosophila melanogaster, and mice. Cobinamide also binds NO, but at molar concentrations 2.5-5 times that of nitroprusside, it did not decrease NO concentrations or the physiological effectiveness of nitroprusside. We conclude that cobinamide could be a valuable adjunct to nitroprusside therapy.

A trained health service workforce is critical to ensuring good quality service delivery to people with HIV. There is only limited documented information on the challenges and constraints facing health care providers in meeting the sexual and reproductive health needs of HIV positive women and men. This paper reviews information on providers' attitudes, motivation and level of preparedness in addressing the sexual and reproductive health needs of people living with HIV in the context of the human resources crisis and emerging treatment and prevention strategies. There is a need for significant investment in improving the health infrastructure and providers' ability to take universal precautions against infection in health care settings. Additionally, there is need for comprehensive and appropriate training for health care providers to build their capacity to meet the requirements and expectations of different sub-populations of HIV positive people. This includes not only physicians but also nurses and midwives, who are the primary caregivers for most of the population in many resource-poor settings. Supportive and knowledgeable providers are crucial for helping HIV positive people seek and adhere to treatment, prevent sexually transmitted infections, unintended pregnancies and vertical transmission of HIV and support positive living free from stigma and discrimination. Providers, some of whom may themselves be HIV positive, can make an important difference, especially if they are supported in their working conditions, are knowledgeable about HIV and sexual and reproductive health and have the skills to provide good quality care.

Septic shock has an extremely high mortality rate, with approximately 200,000 people dying from sepsis annually in the U.S. The high mortality results in part from severe hypotension secondary to high serum NO concentrations. Reducing NO levels should be beneficial in sepsis, but NOS inhibitors have had a checkered history in animal models, and one such agent increased mortality in a clinical trial. An alternative approach to reduce NO levels in sepsis is to use an NO scavenger, which should leave sufficient free NO for normal physiological functions. Using a well-established model of bacterial sepsis in Drosophila melanogaster, we found that cobinamide, a B(12) analog and an effective NO scavenger in vitro, dramatically improved fly survival. Cobinamide augmented the effect of an antibiotic and was beneficial even in immune-deficient flies. Cobinamide's mechanism of action appeared to be from reducing NO levels and improving cardiac function.

Cyanide is a highly toxic agent that inhibits mitochondrial cytochrome-c oxidase, thereby depleting cellular ATP. It contributes to smoke inhalation deaths in fires and could be used as a weapon of mass destruction. Cobalamin (vitamin B12) binds cyanide with a relatively high affinity and is used in Europe to treat smoke inhalation victims. Cobinamide, the penultimate compound in cobalamin biosynthesis, binds cyanide with about 10(10) greater affinity than cobalamin, and we found it was several-fold more effective than cobalamin in (i) reversing cyanide inhibition of oxidative phosphorylation in mammalian cells; (ii) rescuing mammalian cells and Drosophila melanogaster from cyanide toxicity; and (iii) reducing cyanide inhibition of Drosophila Malpighian tubule secretion. Cobinamide could be delivered by oral ingestion, inhalation, or injection to Drosophila, and it was as effective when administered up to 5 mins post-cyanide exposure as when given pre-exposure. We conclude that cobinamide is an effective cyanide detoxifying agent that has potential use as a cyanide antidote, both in smoke inhalation victims and in persons exposed to cyanide used as a weapon of mass destruction.

Methylmalonyl-CoA mutase is a key enzyme in intermediary metabolism, and children deficient in enzyme activity have severe metabolic acidosis. We found that nitric oxide (NO) inhibits methylmalonyl-CoA mutase activity in rodent cell extracts. The inhibition of enzyme activity occurred within minutes and was not prevented by thiols, suggesting that enzyme inhibition was not occurring via NO reaction with cysteine residues to form nitrosothiol groups. Enzyme inhibition was dependent on the presence of substrate, implying that NO was reacting with cobalamin(II) (Cbl(II)) and/or the deoxyadenosyl radical (.CH(2)-Ado), both of which are generated from the co-factor of the enzyme, 5'-deoxyadenosyl-cobalamin (AdoCbl), on substrate binding. Consistent with this hypothesis was the finding that high micromolar concentrations (> or =600 microm) of oxygen also inhibited enzyme activity. To study the mechanism of NO reaction with AdoCbl, we simulated the enzymatic reaction by photolyzing AdoCbl, and found that even at low NO concentrations, NO reacted with both the generated Cbl(II) and .CH(2)-Ado indicating that NO could effectively compete with the back formation of AdoCbl. Thus, NO inhibition of methylmalonyl-CoA mutase appeared to be from the reaction of NO with both AdoCbl intermediates (Cbl(II) and .CH(2)-Ado) generated during the enzymatic reaction. The inhibition of methylmalonyl-CoA mutase by NO was likely of physiological relevance because a NO donor inhibited enzyme activity in intact cells, and scavenging NO from cells or inhibiting cellular NO synthesis increased methylmalonyl-CoA mutase activity when measured subsequently in cell extracts.