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1.
Chem Res Toxicol ; 37(4): 540-544, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38530825

RESUMO

The human hepatocyte suspension model has been a valuable tool to study covalent binding (CVB) for compounds that form reactive metabolites. However, accurately measuring CVB values with the suspension model becomes challenging for metabolically low turnover compounds. In this study, we evaluated the HµREL human hepatocyte coculture model relative to existing literature using human hepatocyte suspension for drugs of known drug-induced liver injury category. Our results indicate that this coculture model provides ample metabolic turnover to reproducibly measure CVB. It is sufficiently robust to apply a predefined 1 mg/day CVB body burden threshold for risk assessment to guide our discovery programs, allowing for expanded coverage to include metabolically low turnover compounds.


Assuntos
Hepatócitos , Humanos , Técnicas de Cocultura , Células Cultivadas , Carga Corporal (Radioterapia) , Hepatócitos/metabolismo , Medição de Risco
2.
Brief Bioinform ; 22(2): 1106-1121, 2021 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-33725111

RESUMO

Whole genome analysis of SARS-CoV-2 is important to identify its genetic diversity. Moreover, accurate detection of SARS-CoV-2 is required for its correct diagnosis. To address these, first we have analysed publicly available 10 664 complete or near-complete SARS-CoV-2 genomes of 73 countries globally to find mutation points in the coding regions as substitution, deletion, insertion and single nucleotide polymorphism (SNP) globally and country wise. In this regard, multiple sequence alignment is performed in the presence of reference sequence from NCBI. Once the alignment is done, a consensus sequence is build to analyse each genomic sequence to identify the unique mutation points as substitutions, deletions, insertions and SNPs globally, thereby resulting in 7209, 11700, 119 and 53 such mutation points respectively. Second, in such categories, unique mutations for individual countries are determined with respect to other 72 countries. In case of India, unique 385, 867, 1 and 11 substitutions, deletions, insertions and SNPs are present in 566 SARS-CoV-2 genomes while 458, 1343, 8 and 52 mutation points in such categories are common with other countries. In majority (above 10%) of virus population, the most frequent and common mutation points between global excluding India and India are L37F, P323L, F506L, S507G, D614G and Q57H in NSP6, RdRp, Exon, Spike and ORF3a respectively. While for India, the other most frequent mutation points are T1198K, A97V, T315N and P13L in NSP3, RdRp, Spike and ORF8 respectively. These mutations are further visualised in protein structures and phylogenetic analysis has been done to show the diversity in virus genomes. Third, a web application is provided for searching mutation points globally and country wise. Finally, we have identified the potential conserved region as target that belongs to the coding region of ORF1ab, specifically to the NSP6 gene. Subsequently, we have provided the primers and probes using that conserved region so that it can be used for detecting SARS-CoV-2. Contact:indrajit@nitttrkol.ac.inSupplementary information: Supplementary data are available at http://www.nitttrkol.ac.in/indrajit/projects/COVID-Mutation-10K.


Assuntos
Proteínas do Nucleocapsídeo de Coronavírus/metabolismo , Genoma Viral , SARS-CoV-2/genética , Proteínas do Nucleocapsídeo de Coronavírus/genética , Humanos , Índia , Mutação , Fases de Leitura Aberta , Polimorfismo de Nucleotídeo Único , Alinhamento de Sequência , Sequenciamento Completo do Genoma
3.
Chem Res Toxicol ; 36(7): 1129-1139, 2023 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-37294641

RESUMO

Drug-induced liver injury (DILI), believed to be a multifactorial toxicity, has been a leading cause of attrition of small molecules during discovery, clinical development, and postmarketing. Identification of DILI risk early reduces the costs and cycle times associated with drug development. In recent years, several groups have reported predictive models that use physicochemical properties or in vitro and in vivo assay endpoints; however, these approaches have not accounted for liver-expressed proteins and drug molecules. To address this gap, we have developed an integrated artificial intelligence/machine learning (AI/ML) model to predict DILI severity for small molecules using a combination of physicochemical properties and off-target interactions predicted in silico. We compiled a data set of 603 diverse compounds from public databases. Among them, 164 were categorized as Most DILI (M-DILI), 245 as Less DILI (L-DILI), and 194 as No DILI (N-DILI) by the FDA. Six machine learning methods were used to create a consensus model for predicting the DILI potential. These methods include k-nearest neighbor (k-NN), support vector machine (SVM), random forest (RF), Naïve Bayes (NB), artificial neural network (ANN), logistic regression (LR), weighted average ensemble learning (WA) and penalized logistic regression (PLR). Among the analyzed ML methods, SVM, RF, LR, WA, and PLR identified M-DILI and N-DILI compounds, achieving a receiver operating characteristic area under the curve of 0.88, sensitivity of 0.73, and specificity of 0.9. Approximately 43 off-targets, along with physicochemical properties (fsp3, log S, basicity, reactive functional groups, and predicted metabolites), were identified as significant factors in distinguishing between M-DILI and N-DILI compounds. The key off-targets that we identified include: PTGS1, PTGS2, SLC22A12, PPARγ, RXRA, CYP2C9, AKR1C3, MGLL, RET, AR, and ABCC4. The present AI/ML computational approach therefore demonstrates that the integration of physicochemical properties and predicted on- and off-target biological interactions can significantly improve DILI predictivity compared to chemical properties alone.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Transportadores de Ânions Orgânicos , Humanos , Inteligência Artificial , Teorema de Bayes , Aprendizado de Máquina , Bases de Dados Factuais , Proteínas de Transporte de Cátions Orgânicos
4.
Chem Res Toxicol ; 35(10): 1777-1788, 2022 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-36200746

RESUMO

Glucuronidation and CoA (coenzyme A) conjugation are common pathways for the elimination of carboxylic acid-containing drug molecules. In some instances, these biotransformations have been associated with toxicity (such as idiosyncratic hepatic injury, renal impairment, hemolytic anemia, gastrointestinal inflammation, and bladder cancer) attributed to, in part, the propensity of acyl glucuronides and acyl CoA thioesters to covalently modify biological macromolecules such as proteins and DNA. It is to be noted that, while acyl glucuronidation and CoA conjugation are indeed implicated in adverse effects, there are many safe drugs in the market that are cleared by these reactive pathways. It is therefore important that new molecular entities with carboxylic acid groups are evaluated for toxicity in a manner that is not unreasonably risk-averse. In the absence of truly predictable methods, therefore, the general approach is to apply a set of end points to generate a weight-of-evidence evaluation. In practice, the focus is to identify structural liabilities and provide structure-activity recommendations early in the program, at a stage where an attempt to improve reactive metabolism does not deoptimize other critical drug-quality criteria. This review will present a high-level overview of the chemistry of glucuronidation and CoA conjugation and provide a discussion of the possible mechanisms of adverse effects that have been associated with these pathways, as well as how such potential hazards are addressed while delivering a new chemical entity for clinical evaluation.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Glucuronídeos , Acil Coenzima A/química , Acil Coenzima A/metabolismo , Ácidos Carboxílicos/química , Coenzima A , Glucuronídeos/metabolismo , Humanos , Proteínas/metabolismo
5.
Chem Res Toxicol ; 35(3): 459-474, 2022 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-35156375

RESUMO

Acyl glucuronide (AG) metabolites of carboxylic acid-containing drugs and products of their transformations have long been implicated in drug-induced liver injury (DILI). To inform on the DILI risk arising from AG reactive intermediates, a comprehensive mechanistic study of enzyme-independent AG rearrangements using nuclear magnetic resonance (NMR) and density functional theory (DFT) was undertaken. NMR spectroscopy was utilized for structure elucidation and kinetics measurements of nine rearrangement and hydrolysis products of 1ß-O-acyl glucuronide of ibufenac. To extract rate constants of rearrangement, mutarotation, and hydrolysis from kinetic data, 11 different kinetic models were examined. Model selection and estimated rate constant verification were supported by measurements of H/D kinetic isotope effects. DFT calculations of ground and transition states supported the proposed kinetic mechanisms and helped to explain the unusually fast intramolecular transacylation rates found for some of the intermediates. The findings of the current study reinforce the notion that the short half-life of parent AG and slow hydrolysis rates of AG rearrangement products are the two key factors that can influence the in vivo toxicity of AGs.


Assuntos
Glucuronídeos , Acilação , Glucuronídeos/metabolismo , Cinética , Espectroscopia de Ressonância Magnética/métodos , Modelos Moleculares
6.
J Opt Soc Am A Opt Image Sci Vis ; 39(10): 1903-1912, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-36215563

RESUMO

Lensless cameras are ultra-thin imaging systems that replace the lens with a thin passive optical mask and computation. Passive mask-based lensless cameras encode depth information in their measurements for a certain depth range. Early works have shown that this encoded depth can be used to perform 3D reconstruction of close-range scenes. However, these approaches for 3D reconstructions are typically optimization based and require strong hand-crafted priors and hundreds of iterations to reconstruct. Moreover, the reconstructions suffer from low resolution, noise, and artifacts. In this work, we propose FlatNet3D-a feed-forward deep network that can estimate both depth and intensity from a single lensless capture. FlatNet3D is an end-to-end trainable deep network that directly reconstructs depth and intensity from a lensless measurement using an efficient physics-based 3D mapping stage and a fully convolutional network. Our algorithm is fast and produces high-quality results, which we validate using both simulated and real scenes captured using PhlatCam.

7.
Bioorg Med Chem Lett ; 32: 127668, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33161125

RESUMO

Cholesteryl ester transfer protein (CETP) inhibitors reduce the transfer of cholesteryl esters from the high-density lipoprotein (HDL-C) to apolipoprotein such as VLDL/LDL, with exchange of triglycerides. Thus, this inhibition increases the HDL-C levels, which is believed to lower the risk for heart disease and stroke. We report here a series of CETP inhibitors based on the cyclic, bicyclic urea and sulfamide cores. These CETP inhibitors exemplified by 15, 31, and 45 demonstrated in vitro potency in inhibiting the CETP transfer activity, and 15, 31 showing in vivo efficacy to increase HDL-C levels in cynomolgus-CETP transgenic mice. The synthesis and biological evaluations of these CETP inhibitors are described.


Assuntos
Anticolesterolemiantes/síntese química , Compostos Bicíclicos com Pontes/química , Proteínas de Transferência de Ésteres de Colesterol/antagonistas & inibidores , Sulfonamidas/química , Ureia/análogos & derivados , Animais , Anticolesterolemiantes/metabolismo , Anticolesterolemiantes/uso terapêutico , Proteínas de Transferência de Ésteres de Colesterol/metabolismo , HDL-Colesterol/sangue , Ciclização , Dislipidemias/tratamento farmacológico , Dislipidemias/patologia , Humanos , Camundongos , Camundongos Transgênicos , Relação Estrutura-Atividade , Sulfonamidas/metabolismo , Sulfonamidas/uso terapêutico , Ureia/metabolismo , Ureia/uso terapêutico
8.
Drug Metab Rev ; 52(3): 333-365, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32645275

RESUMO

Biotransformation is one of the main mechanisms used by the body to eliminate drugs. As drug molecules become more complicated, the involvement of drug metabolizing enzymes increases beyond those that are typically studied, such as the cytochrome P450 enzymes. In this review, we try to capture the many outstanding articles that were published in the past year in the field of biotransformation (see Table 1). We have divided the articles into two categories of (1) metabolites and drug metabolizing enzymes, and (2) bioactivation and safety. This annual review is the fifth of its kind since 2016 (Baillie et al. 2016; Khojasteh et al. 2017, 2018, 2019). This effort in itself also continues to evolve. We have followed the same format we used in previous years in terms of the selection of articles and the authoring of each section. I am pleased of the continued support of Rietjens, Miller, Zhang, Driscoll and Mitra to this review. We would like to welcome Klarissa D. Jackson as a new author for this year's issue. We strive to maintain a balance of authors from academic and industry settings. We would be pleased to hear your opinions of our commentary, and we extend an invitation to anyone who would like to contribute to a future edition of this review. Cyrus Khojasteh, on behalf of the authors.


Assuntos
Biotransformação , Preparações Farmacêuticas/metabolismo , Animais , Sistema Enzimático do Citocromo P-450/metabolismo , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Humanos
9.
Chem Res Toxicol ; 33(1): 191-201, 2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-31566356

RESUMO

MK-8666, a selective GPR40 agonist developed for the treatment of type 2 diabetes mellitus, was discontinued in phase I clinical trials due to liver safety concerns. To address whether chemically reactive metabolites played a causative role in the observed drug induced liver injury (DILI), we characterized the metabolism, covalent binding to proteins, and amino acid targets of MK-8666 in rat and human hepatocytes or cofactor-fortified liver microsomes. MK-8666 was primarily metabolized to an acyl glucuronide in hepatocytes of both species and a taurine conjugate in rat hepatocytes. Similar levels of covalent binding to proteins were observed in rat and human hepatocytes following incubation with [3H]MK-8666. After protease digestion of hepatocyte pellets, amino acid adducts A1, A2, and A3 were identified as transacylated products with lysine, serine, and cysteine residues, respectively. Amino acid adducts A4a-c were identified as glycation adducts resulting from rearrangement of MK-8666-1-O-ß-acyl glucuronide to ring-opened aldehydes which further condensed with lysine residues of proteins into imine adducts. Adducts A1-A3 and A4a-c were detected in rat and human liver microsomes fortified with UDPGA. Adducts A1-A3 were detected in rat and human liver microsomes fortified with CoA and ATP. Additionally, a trace amount of CoA thioester metabolite of MK-8666 and its transacylated GSH adduct were detected in human liver microsomes fortified with CoA, ATP, and GSH. Higher levels of covalent binding to protein were observed when [3H]MK-8666 was incubated in liver microsomes supplemented with CoA and ATP compared to UDPGA. Addition of GSH attenuated levels of CoA thioester-mediated covalent binding by 41-45%. Collectively, these studies indicated that metabolism of the -COOH moiety of MK-8666 can form a reactive acyl glucuronide and an acyl CoA thioester, which covalently modifies proteins and may represent one causative mechanism of the observed DILI.


Assuntos
Hepatócitos/metabolismo , Hipoglicemiantes/farmacologia , Microssomos Hepáticos/metabolismo , Receptores Acoplados a Proteínas G/agonistas , Acilação , Aminoácidos/metabolismo , Animais , Ésteres/metabolismo , Glucuronídeos/metabolismo , Humanos , Ligação Proteica , Ratos
10.
Biotechnol Bioeng ; 117(11): 3368-3378, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32706388

RESUMO

Levels of host cell proteins (HCPs) in purification intermediates and drug substances (DS) of monoclonal antibodies (mAbs) must be carefully monitored for the production of safe and efficacious biotherapeutics. During the development of mAb1, an immunoglobulin G1 product, unexpected results generated with HCP Enzyme-Linked Immunosorbent Assay (ELISA) kit triggered an investigation which led to the identification of a copurifying HCP called N-(4)-(ß-acetylglucosaminyl)-l-asparaginase (AGA, EC3.5.1.26) by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The risk assessment performed indicated a low immunogenicity risk for the copurifying HCP and an ad hoc stability study demonstrated no mAb glycan cleavage and thus no impact on product quality. Fractionation studies performed on polishing steps revealed that AGA was coeluted with the mAb. Very interestingly, the native digestion protocol implemented to go deeper in the MS-HCP profiling was found to be incompatible with correct AGA detection in last purification intermediate and DS, further suggesting a hitchhiking behavior of AGA. In silico surface characterization of AGA also supports this hypothesis. Finally, the combined support of HCP ELISA results and MS allowed process optimization and removal of this copurifying HCP.


Assuntos
Asparaginase/química , Cromatografia Líquida/métodos , Ensaio de Imunoadsorção Enzimática/métodos , Glucosamina/química , Espectrometria de Massas em Tandem/métodos , Anticorpos Monoclonais/metabolismo , Proteínas/análise , Proteínas/química , Proteínas/isolamento & purificação , Proteínas Recombinantes/metabolismo
11.
Drug Metab Rev ; 51(2): 121-161, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31170851

RESUMO

In the past three decades, ADME sciences have become an integral component of the drug discovery and development process. At the same time, the field has continued to evolve, thus, requiring ADME scientists to be knowledgeable of and engage with diverse aspects of drug assessment: from pharmacology to toxicology, and from in silico modeling to in vitro models and finally in vivo models. Progress in this field requires deliberate exposure to different aspects of ADME; however, this task can seem daunting in the current age of mass information. We hope this review provides a focused and brief summary of a wide array of critical advances over the past year and explains the relevance of this research ( Table 1 ). We divided the articles into categories of (1) drug optimization, (2) metabolites and drug metabolizing enzymes, and (3) bioactivation. This annual review is the fourth of its kind (Baillie et al. 2016 ; Khojasteh et al. 2017 , 2018 ). We have followed the same format we used in previous years in terms of the selection of articles and the authoring of each section. This effort in itself also continues to evolve. I am pleased that Rietjens, Miller, and Mitra have again contributed to this annual review. We would like to welcome Namandjé N. Bumpus, James P. Driscoll, and Donglu Zhang as authors for this year's issue. We strive to maintain a balance of authors from academic and industry settings. We would be pleased to hear your opinions of our commentary, and we extend an invitation to anyone who would like to contribute to a future edition of this review. Cyrus Khojasteh, on behalf of the authors.


Assuntos
Ativação Metabólica , Biotransformação , Animais , Humanos
12.
Chem Res Toxicol ; 32(8): 1528-1544, 2019 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-31271030

RESUMO

Human hepatocellular carcinoma cells, HepG2, are often used for drug mediated mitochondrial toxicity assessments. Glucose in HepG2 culture media is replaced by galactose to reveal drug-induced mitochondrial toxicity as a marked shift of drug IC50 values for the reduction of cellular ATP. It has been postulated that galactose sensitizes HepG2 mitochondria by the additional ATP consumption demand in the Leloir pathway. However, our NMR metabolomics analysis of HepG2 cells and culture media showed very limited galactose metabolism. To clarify the role of galactose in HepG2 cellular metabolism, U-13C6-galactose or U-13C6-glucose was added to HepG2 culture media to help specifically track the metabolism of those two sugars. Conversion to U-13C3-lactate was hardly detected when HepG2 cells were incubated with U-13C6-galactose, while an abundance of U-13C3-lactate was produced when HepG2 cells were incubated with U-13C6-glucose. In the absence of glucose, HepG2 cells increased glutamine consumption as a bioenergetics source. The requirement of additional glutamine almost matched the amount of glucose needed to maintain a similar level of cellular ATP in HepG2 cells. This improved understanding of galactose and glutamine metabolism in HepG2 cells helped optimize the ATP-based mitochondrial toxicity assay. The modified assay showed 96% sensitivity and 97% specificity in correctly discriminating compounds known to cause mitochondrial toxicity from those with prior evidence of not being mitochondrial toxicants. The greatest significance of the modified assay was its improved sensitivity in detecting the inhibition of mitochondrial fatty acid ß-oxidation (FAO) when glutamine was withheld. Use of this improved assay for an empirical prediction of the likely contribution of mitochondrial toxicity to human DILI (drug induced liver injury) was attempted. According to testing of 65 DILI positive compounds representing numerous mechanisms of DILI together with 55 DILI negative compounds, the overall prediction of mitochondrial mechanism-related DILI showed 25% sensitivity and 95% specificity.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Galactose/metabolismo , Glucose/metabolismo , Mitocôndrias Hepáticas/metabolismo , Amiodarona/farmacologia , Benzobromarona/farmacologia , Células Hep G2 , Humanos , Metabolômica , Mitocôndrias Hepáticas/efeitos dos fármacos , Piperazinas/farmacologia , Triazóis/farmacologia , Troglitazona/farmacologia , Células Tumorais Cultivadas
13.
Drug Metab Rev ; 50(3): 221-255, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29954222

RESUMO

This annual review is the third one to highlight recent advances in the study and assessment of biotransformations and bioactivations ( Table 1 ). We followed the same format as the previous years with selection and authoring each section (see Baillie et al. 2016 ; Khojasteh et al. 2017 ). We acknowledge that many universities no longer train students in mechanistic biotransformation studies reflecting a decline in the investment for those efforts by public funded granting institutions. We hope this work serves as a resource to appreciate the knowledge gained each year to understand and hopefully anticipate toxicological outcomes dependent on biotransformations and bioactivations. This effort itself also continues to evolve. I am pleased that Drs. Rietjens and Miller have again contributed to this annual review. We would like to welcome Kaushik Mitra as an author for this year's issue, and we thank Deepak Dalvie for his contributions to last year's edition. We have intentionally maintained a balance of authors such that two come from an academic setting and two come from industry. As always, please drop us a note if you find this review helpful. We would be pleased to hear your opinions of our commentary, and we extend an invitation to anyone who would like to contribute to a future edition of this review.


Assuntos
Preparações Farmacêuticas/metabolismo , Ativação Metabólica , Animais , Biotransformação , Humanos
14.
J Assoc Physicians India ; 66(5): 22-5, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-30477057

RESUMO

Background and Aims: Scrub typhus is the commonest of the rickettsial diseases in India and is difficult to diagnose. Untreated cases have fatality rates of 30-45%. Eschar is present in 7-97% cases. Pneumonia and acute respiratory distress syndrome (ARDS) are frequent complications. Serum immunoglobulin M capture ELISA is the most sensitive test. Doxycycline is the drug of choice. Our objectives were to study the socio-demographic and clinic-epidemiological profiles of scrub typhus cases in two tertiary care hospitals in Kolkata, India. This was the first study of scrub typhus in Southern West Bengal and its neighboring areas. . Methods: Study was conducted over 16 months and all fever cases of Tropical Medicine / Medicine outpatients' clinics were evaluated. Results: Fourteen cases were diagnosed. 78.6% were from rural areas and 35.7% were farmers. Headache and fever were the commonest presenting complaints while eschar was found in only 21.4%. Serum IgM scrub typhus antibody was positive in all cases . Conclusion: Scrub typhus should be a differential diagnosis in acute febrile illness cases, as early diagnosis and therapy prevents complications.


Assuntos
Orientia tsutsugamushi , Tifo por Ácaros , Demografia , Humanos , Índia , Tifo por Ácaros/epidemiologia , Centros de Atenção Terciária
15.
Bioorg Med Chem Lett ; 27(9): 2069-2073, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28284804

RESUMO

Glucokinase (GK, hexokinase IV) is a unique hexokinase that plays a central role in mammalian glucose homeostasis. Glucose phosphorylation by GK in the pancreatic ß-cell is the rate-limiting step that controls glucose-stimulated insulin secretion. Similarly, GK-mediated glucose phosphorylation in hepatocytes plays a major role in increasing hepatic glucose uptake and metabolism and possibly lowering hepatic glucose output. Small molecule GK activators (GKAs) have been identified that increase enzyme activity by binding to an allosteric site. GKAs offer a novel approach for the treatment of Type 2 Diabetes Mellitus (T2DM) and as such have garnered much attention. We now report the design, synthesis, and biological evaluation of a novel series of 2,5,6-trisubstituted indole derivatives that act as highly potent GKAs. Among them, Compound 1 was found to possess high in vitro potency, excellent physicochemical properties, and good pharmacokinetic profile in rodents. Oral administration of Compound 1 at doses as low as 0.03mg/kg led to robust blood glucose lowering efficacy in 3week high fat diet-fed mice.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Ativadores de Enzimas/química , Ativadores de Enzimas/uso terapêutico , Glucoquinase/metabolismo , Hipoglicemiantes/química , Hipoglicemiantes/uso terapêutico , Indóis/química , Indóis/uso terapêutico , Regulação Alostérica/efeitos dos fármacos , Animais , Glicemia/análise , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/metabolismo , Desenho de Fármacos , Ativação Enzimática/efeitos dos fármacos , Ativadores de Enzimas/farmacocinética , Ativadores de Enzimas/farmacologia , Humanos , Hipoglicemiantes/farmacocinética , Hipoglicemiantes/farmacologia , Indóis/farmacocinética , Indóis/farmacologia , Insulina/sangue , Insulina/metabolismo , Camundongos , Camundongos Endogâmicos C57BL
16.
Bioorg Med Chem Lett ; 27(9): 2063-2068, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28284809

RESUMO

Systemically acting glucokinase activators (GKA) have been demonstrated in clinical trials to effectively lower blood glucose in patients with type II diabetes. However, mechanism-based hypoglycemia is a major adverse effect that limits the therapeutic potential of these agents. We hypothesized that the predominant mechanism leading to hypoglycemia is GKA-induced excessive insulin secretion from pancreatic ß-cells at (sub-)euglycemic levels. We further hypothesized that restricting GK activation to hepatocytes would maintain glucose-lowering efficacy while significantly reducing hypoglycemic risk. Here we report the discovery of a novel series of carboxylic acid substituted GKAs based on pyridine-2-carboxamide. These GKAs exhibit preferential distribution to the liver versus the pancreas in mice. SAR studies led to the identification of a potent and orally active hepatoselective GKA, compound 6. GKA 6 demonstrated robust glucose lowering efficacy in high fat diet-fed mice at doses ⩾10mpk, with ⩾70-fold liver:pancreas distribution, minimal effects on plasma insulin levels, and significantly reduced risk of hypoglycemia.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Ativadores de Enzimas/farmacologia , Glucoquinase/metabolismo , Hipoglicemiantes/farmacologia , Piridinas/farmacologia , Animais , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/metabolismo , Descoberta de Drogas , Ativadores de Enzimas/química , Ativadores de Enzimas/farmacocinética , Ativadores de Enzimas/uso terapêutico , Humanos , Hipoglicemiantes/química , Hipoglicemiantes/farmacocinética , Hipoglicemiantes/uso terapêutico , Insulina/sangue , Fígado/efeitos dos fármacos , Fígado/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Pâncreas/efeitos dos fármacos , Pâncreas/metabolismo , Piridinas/química , Piridinas/farmacocinética , Piridinas/uso terapêutico
17.
Indian J Public Health ; 61(1): 55-57, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28218165

RESUMO

Recently, there is a growing concern about stress during undergraduate medical training. The objectives of our study were to assess perceived stress among undergraduate medical students and to find out academic factors as determinants. A cross-sectional, questionnaire-based survey was carried out among undergraduate medical students of R. G. Kar Medical College, India, during July 2011-June 2012. Perceived stress was assessed using the Perceived Stress Scale-14. A 10-item questionnaire was used to assess academic sources of stress and their severity. The overall mean perceived stress score was 29.58 (standard deviation [SD] = 6.60), and 46.3% of the participants were in the group of more stressed (perceived stress score ≥28). The academic stressor factors predicted 78% of variability of perceived stress. A higher level of perceived stress was reported by the students. The students should be taught different stress management techniques to improve their ability to cope with a demanding professional course.


Assuntos
Estresse Psicológico/etiologia , Estudantes de Medicina/psicologia , Estudos Transversais , Educação de Graduação em Medicina , Feminino , Humanos , Índia , Masculino , Inquéritos e Questionários , Adulto Jovem
18.
Drug Metab Dispos ; 44(3): 428-34, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26712818

RESUMO

The cholesteryl ester transfer protein (CETP) inhibitor anacetrapib exhibits a long terminal half-life (t½) in humans; however, the dispositional mechanisms that lead to this long t½ are still being elucidated. As it is hypothesized that disposition into adipose tissue and binding to CETP might play a role, we sought to delineate the relative importance of these factors using a preclinical animal model. A multiple-dose pharmacokinetic study was conducted in C57BL6 wild-type (WT) lean, WT diet-induced obese (DIO), natural flanking region (NFR) CETP-transgenic lean, and NFR-DIO mice. Mice were dosed orally with 10 mg/kg anacetrapib daily for 42 days. Drug concentrations in blood, brown and white adipose tissue, liver, and brain were measured up to 35 weeks postdose. During dosing, a 3- to 9-fold accumulation in 72-hour postdose blood concentrations of anacetrapib was observed. Drug concentrations in white adipose tissue accumulated ∼20- to 40-fold, whereas 10- to 17-fold accumulation occurred in brown adipose and approximately 4-fold in liver. Brain levels were very low (<0.1 µM), and a trend of accumulation was not seen. The presence of CETP as well as adiposity seems to play a role in determining the blood concentrations of anacetrapib. The highest blood concentrations were observed in NFR DIO mice, whereas the lowest concentrations were seen in WT lean mice. In adipose and liver tissue, higher concentrations were seen in DIO mice, irrespective of the presence of CETP. This finding suggests that white adipose tissue serves as a potential depot and that disposition into adipose tissue governs the long-term kinetics of anacetrapib in vivo.


Assuntos
Tecido Adiposo/metabolismo , Proteínas de Transferência de Ésteres de Colesterol/antagonistas & inibidores , Proteínas de Transferência de Ésteres de Colesterol/metabolismo , Oxazolidinonas/metabolismo , Animais , Dieta , Cinética , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/metabolismo
19.
J Immunol ; 193(8): 3947-58, 2014 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-25210119

RESUMO

Biologic drugs, including enzyme-replacement therapies, can elicit anti-drug Abs (ADA) that may interfere with drug efficacy and impact patient safety. In an effort to control ADA, we focused on identifying regimens of immune tolerance induction that may be readily available for clinical use. Data generated in both wild-type mice and a Pompe disease mouse model demonstrate that single-cycle, low-dose methotrexate can be as effective as three cycles of methotrexate in providing a long-lived reduction in alglucosidase alfa-specific ADA. In addition, we show that methotrexate induces Ag-specific tolerance as mice generate similar Ab responses to an irrelevant Ag regardless of prior methotrexate treatment. Methotrexate-induced immune tolerance does not seem to involve cell depletion, but rather a specific expansion of IL-10- and TGF-ß-secreting B cells that express Foxp3, suggesting an induction of regulatory B cells. The mechanism of immune tolerance induction appears to be IL-10 dependent, as methotrexate does not induce immune tolerance in IL-10 knockout mice. Splenic B cells from animals that have been tolerized to alglucosidase alfa with methotrexate can transfer tolerance to naive hosts. We hypothesize that methotrexate induction treatment concomitant with initial exposure to the biotherapeutic can induce Ag-specific immune tolerance in mice through a mechanism that appears to involve the induction of regulatory B cells.


Assuntos
Linfócitos B Reguladores/imunologia , Antagonistas do Ácido Fólico/farmacologia , Tolerância Imunológica/efeitos dos fármacos , Metotrexato/farmacologia , alfa-Glucosidases/imunologia , Transferência Adotiva , Animais , Antígenos CD1d/imunologia , Antimetabólitos Antineoplásicos/farmacologia , Linfócitos B Reguladores/efeitos dos fármacos , Linfócitos B Reguladores/transplante , Antígenos CD5/imunologia , Linfócitos T CD8-Positivos/imunologia , Fatores de Transcrição Forkhead/biossíntese , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Interleucina-10/genética , Interleucina-10/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Linfócitos T Reguladores/imunologia , Fator de Crescimento Transformador beta/metabolismo
20.
Bioanalysis ; 15(24): 1461-1468, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38044848

RESUMO

While using the cloud environment for various functions has become commonplace, relatively little attention has been given to considerations for the use of third-party cloud services for regulated bioanalytical workflow and data management. Little guidance has been provided as to how to utilize the cloud to support bioanalytical activities. It can be intimidating when considering how to go about using cloud services for data acquisition, but there are some general ideas to keep in mind when evaluating ways to accommodate regulated bioanalysis online. Determining how to incorporate the use of cloud storage with data that are generated from regulated bioanalytical analysis is an important step in maintaining the security of the data.


Assuntos
Computação em Nuvem
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