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1.
Plant Mol Biol ; 108(6): 565-583, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35106703

RESUMO

KEY MESSAGE: Transcriptome landscape during early inflorescence developmental stages identified candidate flowering time regulators including Early Flowering 3a. Further genomics approaches validated the role of this gene in flowering time regulation. The early stages of inflorescence development in plants are as crucial as the later floral developmental stages. Several traits, such as inflorescence architecture and flower developmental timings, are determined during those early stages. In chickpea, diverse forms of inflorescence architectures regarding meristem determinacy and the number of flowers per node are observed within the germplasm. Transcriptome analysis in four desi chickpea accessions with such unique inflorescence characteristics identifies the underlying shared regulatory events leading to inflorescence development. The vegetative to reproductive stage transition brings about major changes in the transcriptome landscape. The inflorescence development progression associated genes identified through co-expression network analysis includes both protein-coding genes and long non-coding RNAs (lncRNAs). Few lncRNAs identified in our study positively regulate flowering-related mRNA stability by acting competitively with miRNAs. Bulk segregrant analysis and association mapping narrowed down an InDel marker regulating flowering time in chickpea. Deletion of 11 bp in first exon of a negative flowering time regulator, Early Flowering 3a gene, leads to early flowering phenotype in chickpea. Understanding the key players involved in vegetative to reproductive stage transition and floral meristem development will be useful in manipulating flowering time and inflorescence architecture in chickpea and other legumes.


Assuntos
Cicer , Cicer/genética , Flores/fisiologia , Regulação da Expressão Gênica de Plantas , Inflorescência/genética , Meristema/genética , Fenótipo , Transcriptoma
2.
Public Health ; 198: 273-279, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34492508

RESUMO

OBJECTIVES: The role of overcrowded and multigenerational households as a risk factor for COVID-19 remains unmeasured. The objective of this study is to examine and quantify the association between overcrowded and multigenerational households and COVID-19 in New York City (NYC). STUDY DESIGN: Cohort study. METHODS: We conducted a Bayesian ecological time series analysis at the ZIP Code Tabulation Area (ZCTA) level in NYC to assess whether ZCTAs with higher proportions of overcrowded (defined as the proportion of the estimated number of housing units with more than one occupant per room) and multigenerational households (defined as the estimated percentage of residences occupied by a grandparent and a grandchild less than 18 years of age) were independently associated with higher suspected COVID-19 case rates (from NYC Department of Health Syndromic Surveillance data for March 1 to 30, 2020). Our main measure was an adjusted incidence rate ratio (IRR) of suspected COVID-19 cases per 10,000 population. Our final model controlled for ZCTA-level sociodemographic factors (median income, poverty status, White race, essential workers), the prevalence of clinical conditions related to COVID-19 severity (obesity, hypertension, coronary heart disease, diabetes, asthma, smoking status, and chronic obstructive pulmonary disease), and spatial clustering. RESULTS: 39,923 suspected COVID-19 cases were presented to emergency departments across 173 ZCTAs in NYC. Adjusted COVID-19 case rates increased by 67% (IRR 1.67, 95% CI = 1.12, 2.52) in ZCTAs in quartile four (versus one) for percent overcrowdedness and increased by 77% (IRR 1.77, 95% CI = 1.11, 2.79) in quartile four (versus one) for percent living in multigenerational housing. Interaction between both exposures was not significant (ßinteraction = 0.99, 95% CI: 0.99-1.00). CONCLUSIONS: Overcrowdedness and multigenerational housing are independent risk factors for suspected COVID-19. In the early phase of the surge in COVID cases, social distancing measures that increase house-bound populations may inadvertently but temporarily increase SARS-CoV-2 transmission risk and COVID-19 disease in these populations.


Assuntos
COVID-19 , Teorema de Bayes , Estudos de Coortes , Humanos , SARS-CoV-2 , Fatores Socioeconômicos
3.
Plant J ; 98(5): 864-883, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30758092

RESUMO

Plant height (PH) and plant width (PW), two of the major plant architectural traits determining the yield and productivity of a crop, are defined by diverse morphometric characteristics of the shoot apical meristem (SAM). The identification of potential molecular tags from a single gene that simultaneously modulates these plant/SAM architectural traits is therefore prerequisite to achieve enhanced yield and productivity in crop plants, including chickpea. Large-scale multienvironment phenotyping of the association panel and mapping population have ascertained the efficacy of three vital SAM morphometric trait parameters, SAM width, SAM height and SAM area, as key indicators to unravel the genetic basis of the wide PW and PH trait variations observed in desi chickpea. This study integrated a genome-wide association study (GWAS); quantitative trait locus (QTL)/fine-mapping and map-based cloning with molecular haplotyping; transcript profiling; and protein-DNA interaction assays for the dissection of plant architectural traits in chickpea. These exertions delineated natural alleles and superior haplotypes from a CabHLH121 transcription factor (TF) gene within the major QTL governing PW, PH and SAM morphometric traits. A genome-wide protein-DNA interaction assay assured the direct binding of a known stem cell master regulator, CaWUS, to the WOX-homeodomain TF binding sites of a CabHLH121 gene and its constituted haplotypes. The differential expression of CaWUS and transcriptional regulation of its target CabHLH121 gene/haplotypes were apparent, suggesting their collective role in altering SAM morphometric characteristics and plant architectural traits in the contrasting near isogenic lines (NILs). The NILs introgressed with a superior haplotype of a CabHLH121 exhibited optimal PW and desirable PH as well as enhanced yield and productivity without compromising any component of agronomic performance. These molecular signatures of the CabHLH121 TF gene have the potential to regulate both PW and PH traits through the modulation of proliferation, differentiation and maintenance of the meristematic stem cell population in the SAM; therefore, these signatures will be useful in the translational genomic study of chickpea genetic enhancement. The restructured cultivars with desirable PH (semidwarf) and PW will ensure maximal planting density in a specified cultivable field area, thereby enhancing the overall yield and productivity of chickpea. This can essentially facilitate the achievement of better remunerative outputs by farmers with rational land use, therefore ensuring global food security in the present scenario of an increasing population density and shrinking per capita land area.


Assuntos
Biomassa , Cicer/genética , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas , Meristema/genética , Brotos de Planta/genética , Alelos , Mapeamento Cromossômico , Cicer/anatomia & histologia , Cicer/metabolismo , Genes de Plantas/genética , Genoma de Planta/genética , Genômica/métodos , Genótipo , Haplótipos , Meristema/anatomia & histologia , Meristema/metabolismo , Brotos de Planta/anatomia & histologia , Brotos de Planta/metabolismo , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas/genética
4.
Indian J Radiol Imaging ; 33(4): 567-570, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37811183

RESUMO

Intracranial granulomas are a major cause of seizures in India, the most common etiologies being neurocysticercosis and tuberculosis. However, other pathologies including rare low-grade tumors may mimic these granulomas on imaging. In this article, we presented the case of a young woman patient with drug-resistant epilepsy. On imaging, there was a small calcified lesion in the brain parenchyma. In view of concordant electroclinical and imaging data on presurgical evaluation, the lesion was excised and the patient was seizure free. On histopathological evaluation, it was found to be a polymorphous low-grade neuroepithelial tumor of the young (PLNTY) - a rare, recently reported entity that can mimic an intracranial granuloma on imaging.

5.
Sci Rep ; 11(1): 8746, 2021 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-33888741

RESUMO

Genome sequencing projects unearth sequences of all the protein sequences encoded in a genome. As the first step, homology detection is employed to obtain clues to structure and function of these proteins. However, high evolutionary divergence between homologous proteins challenges our ability to detect distant relationships. In the past, an approach involving multiple Position Specific Scoring Matrices (PSSMs) was found to be more effective than traditional single PSSMs. Cascaded search is another successful approach where hits of a search are queried to detect more homologues. We propose a protocol, 'Master Blaster', which combines the principles adopted in these two approaches to enhance our ability to detect remote homologues even further. Assessment of the approach was performed using known relationships available in the SCOP70 database, and the results were compared against that of PSI-BLAST and HHblits, a hidden Markov model-based method. Compared to PSI-BLAST, Master Blaster resulted in 10% improvement with respect to detection of cross superfamily connections, nearly 35% improvement in cross family and more than 80% improvement in intra family connections. From the results it was observed that HHblits is more sensitive in detecting remote homologues compared to Master Blaster. However, there are true hits from 46-folds for which Master Blaster reported homologs that are not reported by HHblits even using the optimal parameters indicating that for detecting remote homologues, use of multiple methods employing a combination of different approaches can be more effective in detecting remote homologs. Master Blaster stand-alone code is available for download in the supplementary archive.


Assuntos
Proteínas/química , Análise de Sequência de Proteína/métodos , Algoritmos , Bases de Dados de Proteínas , Matrizes de Pontuação de Posição Específica
6.
Acta Psychiatr Scand ; 122(3): 226-34, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20085556

RESUMO

OBJECTIVE: To evaluate psychometric properties and comparability ability of the Montgomery-Asberg Depression Rating Scale (MADRS) vs. the Quick Inventory of Depressive Symptomatology-Clinician-rated (QIDS-C(16)) and Self-report (QIDS-SR(16)) scales to detect a current major depressive episode in the elderly. METHOD: Community and clinic subjects (age >or=60 years) were administered the Mini-International Neuropsychiatric Interview (MINI) for DSM-IV and three depression scales randomly. Statistics included classical test and Samejima item response theories, factor analyzes, and receiver operating characteristic methods. RESULTS: In 229 elderly patients (mean age = 73 years, 39% male, 54% current depression), all three scales were unidimensional and with nearly equal Cronbach alpha reliability (0.85-0.89). Each scale discriminated persons with major depression from the non-depressed, but the QIDS-C(16) was slightly more accurate. CONCLUSION: All three tests are valid for detecting geriatric major depression with the QIDS-C(16) being slightly better. Self-rated QIDS-SR(16) is recommended as a screening tool as it is least expensive and least time consuming.


Assuntos
Transtorno Depressivo Maior/diagnóstico , Determinação da Personalidade/estatística & dados numéricos , Inventário de Personalidade/estatística & dados numéricos , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Transtorno Depressivo Maior/psicologia , Feminino , Humanos , Masculino , Programas de Rastreamento/estatística & dados numéricos , Pessoa de Meia-Idade , Psicometria/estatística & dados numéricos , Curva ROC , Reprodutibilidade dos Testes
7.
J Obstet Gynaecol ; 30(1): 41-5, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20121503

RESUMO

The present study was done to show the incidence of polycystic ovarian syndrome (PCOS) in rural young women with menstrual irregularities and the correlation with different variables. During the study period, 19,339 women had attended as a gynaecological outpatient unit. A total of 9,096 (47%) of them were of 15-34 years age, of whom 1,182 (13%) had menstrual disturbances. Out of the 1,182 young women, 216 were the study subjects as per inclusion-exclusion criteria, but only 200 could be studied. After complete clinical, ultrasonographic and biochemical evaluation, it was revealed that PCOS is common in rural young women of low socioeconomic class. Such women presenting with menstrual irregularities need to be investigated for the presence of other endocrine disorders which may be present with or without PCOS. PCOS was diagnosed in 100 (50%) women. Of the 100 without PCOS, five had thyroid disorders and of the other 95, 49 (51%) had polycystic ovaries on sonography. Significantly more study objects had a family history of hypertension, diabetes and menstrual irregularities in their mothers. A state of hyperinsulinaemia indicated by a low fasting glucose to insulin ratio was present, even in non-obese women with PCOS.


Assuntos
Distúrbios Menstruais/epidemiologia , Síndrome do Ovário Policístico/epidemiologia , Adolescente , Adulto , Feminino , Humanos , Incidência , Índia/epidemiologia , Distúrbios Menstruais/diagnóstico por imagem , Síndrome do Ovário Policístico/diagnóstico por imagem , População Rural/estatística & dados numéricos , Fatores Socioeconômicos , Ultrassonografia , Adulto Jovem
8.
J Fluoresc ; 19(3): 479-85, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19002573

RESUMO

A new bi-luminophore system for optical sensing of temperature is described. The coating was fabricated by embedding europium thenoyltrifluoroacetonate (EuTTA) and perylene in polystyrene (PS) matrix. The luminescence emission of EuTTA was sensitive to temperature whereas perylene emission was temperature-insensitive and was used as a reference. Both luminophores were excited in the UV region of about 330 to 380 nm. The fluorescence emission of perylene and EuTTA occured at 474 nm and 615 nm respectively. The temperature sensitivities of both luminophores were influenced by (i) the type of polymer, and (ii) the concentration of luminophore in the matrix. Combining EuTTA and perylene in polystyrene matrix, a new bi-luminophore temperature sensing coating was developed. The temperature sensitivity of this coating was -1.80%/ degrees C in the temperature range of 5 degrees C to 50 degrees C. The emission characteristics of this temperature sensitive coating displayed a fully reversible response to temperature.

10.
Saudi Med J ; 30(3): 433-5, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19271078

RESUMO

Esophageal foreign body (EFB) ingestion is of ubiquitous occurrence in pediatric population. Diagnosis and precise localization of non-radio opaque FB poses considerable challenge. Delayed presentation, poor history, and inconclusive esophagoscopic findings often lead to diagnostic delay. Multidetector computed tomography (MDCT) could be a great option in these situations. We present a case of EFB in a child who presented with failure to thrive, had negative fibreoptic endoscopy, ultimately diagnosed conclusively on MDCT examination.


Assuntos
Esôfago/diagnóstico por imagem , Esôfago/lesões , Corpos Estranhos/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Diagnóstico Diferencial , Esofagoscopia , Esôfago/cirurgia , Feminino , Corpos Estranhos/cirurgia , Humanos , Lactente
11.
J Clin Diagn Res ; 10(3): TD12-3, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27134968

RESUMO

Functional information regarding fluid movement within the body can be derived by magnetic resonance methods. Some of the observations were overlooked in early days of magnetic resonance imaging (MRI) application. This presentation illustrates an unique, intra-hepatic haemodynamic phenomenon, demonstrated by magnetic resonance imaging, in a case of infra-cardiac Total Anomalous Pulmonary Venous Connection (TAPVC) Demonstration of such phenomena is unreported even after widespread use of cardiac MRI, although patho-physiology of such a phenomenon is expected in TAPVC. Brief explanation and possible basis of such observation in the context of current knowledge is discussed.

12.
Eur J Pharm Biopharm ; 108: 156-167, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27615995

RESUMO

The anti-vascular endothelial growth factor (VEGF) agents such as ranibizumab (Lucentis®) and aflibercept (EyLea®) are currently used as monthly or bimonthly intravitreal injections to treat potentially retinal diseases such as wet age-related macular degeneration (AMD) or diabetic macular edema (DME). Because of the complications associated with repeated intra-vitreal injections, there is considerable interest in developing a sustained delivery system. The purpose of this study was to examine the stability of both therapeutic proteins under physiological conditions as well as when incorporated into drug delivery systems (DDS). First, thermotropic properties in physiological conditions and at different pH values were evaluated by differential scanning calorimetry (DSC) to determine the protein denaturation temperature. Second, the effects of pH and incubation time on conformational changes and aggregation were evaluated by circular dichroism (CD), steady-state tryptophan fluorescence spectroscopy, and size-exclusion chromatography (SEC). Also, the ability of both proteins to bind to VEGF was tested in the aforementioned experimental conditions for up to 30 days. Finally, we investigated the stability of both proteins after a rapid screening method that simulates the first homogenizing step during the protein microencapsulation process. This method allowed the development of stable ranibizumab and aflibercept formulations that may be useful to entrap these proteins into microparticles selecting the most convenient organic solvent and protein stabilizers.


Assuntos
Estabilidade de Medicamentos , Ranibizumab/química , Receptores de Fatores de Crescimento do Endotélio Vascular/química , Proteínas Recombinantes de Fusão/química , Varredura Diferencial de Calorimetria , Cromatografia , Dicroísmo Circular , Emulsões , Ensaio de Imunoadsorção Enzimática , Temperatura Alta , Humanos , Concentração de Íons de Hidrogênio , Edema Macular/tratamento farmacológico , Nanopartículas/química , Estrutura Secundária de Proteína , Solventes/química , Temperatura , Raios Ultravioleta , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fator A de Crescimento do Endotélio Vascular/química , Degeneração Macular Exsudativa/tratamento farmacológico
13.
J Clin Diagn Res ; 9(6): TD05-6, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26266188

RESUMO

Spontaneous extension of air from the pleural space to the chest wall, also referred to as pneumothorax necessitans (PN), is a rare occurrence. Few of such cases have been reported in the literature, some appear to have a pattern of extension from pleural cavity to chest wall. Clinical conditions known to predispose to this complication are pneumothorax, empyema thoracis and tuberculosis of the pleural space or rib. We report a case of PN arising as complication of postpneumonectomy empyema (PPE) secondary to broncho-pleural fistula. Imaging features are highlighted emphasizing the likely pattern of spread.

14.
Curr Med Chem Anticancer Agents ; 2(2): 187-207, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12678743

RESUMO

The utility of light as a therapeutic agent can be traced back over thousands of years when it was used in Ancient Egypt, India and China to treat a variety of skin diseases like psoriasis, vitiligo, rickets, cancer and psychosis. The isolation of porphyrins and their inherent tumor localizing properties coupled with its ability to generate reactive singlet oxygen when activated by light of particular wavelength which in turn results in cytotoxicity led to the emergence of a new modality namely, photodynamic therapy (PDT) as a therapeutic tool. The higher degree of selectivity offered by this modality and fewer side effects when compared to chemotherapy and radiotherapy has prompted the researchers around the globe to generate new photosensitizers. Porphyrins and expanded porphyrins are one class of molecules under intense investigation due to their photosensitizing ability for PDT application. Expanded porphyrins result from the expansion of the phi electron conjugation by increasing the number of heterocyclic rings or bridging carbons of the existing porphyrin framework. These chromophores show strong absorptions in the red region (650-800 nm) compared to that of normal 18phi porphyrins. The strong absorption of light by a water soluble nontoxic photosensitizing molecule in the therapeutic window resulting in maximum penetration of light into the tissues coupled with high singlet oxygen production will conceptualize an ideal photosensitizer. This review highlights various porphyrinoid sensitizers reported till date and their photosensitizing ability both in vitro and in vivo studies. Furthermore, the urgent need for developing ideal photosensitizer for PDT will also be highlighted.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias/tratamento farmacológico , Fotoquimioterapia , Fármacos Fotossensibilizantes/uso terapêutico , Porfirinas/uso terapêutico , Animais , Antineoplásicos/farmacologia , Humanos , Fármacos Fotossensibilizantes/farmacologia , Porfirinas/farmacologia
15.
J Med Chem ; 37(23): 3939-46, 1994 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-7966155

RESUMO

The ability of quisqualic acid (1) to sensitize neurons to depolarization by omega-phosphono alpha-amino acid analogues of excitatory amino acids is a highly specific phenomenon and is termed the QUIS effect. In an attempt to elucidate the structure-activity relationships for this sensitization, analogues 2-6 of quisqualic acid have been synthesized. Compounds 4, 5, and 6 showed no quisqualate sensitization with respect to L-2-amino-6-phosphonohexanoic acid (L-AP6), while compounds 2 and 3 were 1/10 and 1/1000, respectively, as active as quisqualic acid in sensitizing neurons toward L-AP6.


Assuntos
Hipocampo/efeitos dos fármacos , Oxidiazóis/química , Ácido Quisquálico/análogos & derivados , Animais , Hipocampo/metabolismo , Técnicas In Vitro , Masculino , Ácido Quisquálico/síntese química , Ácido Quisquálico/farmacologia , Ratos , Ratos Sprague-Dawley , Relação Estrutura-Atividade
16.
J Med Chem ; 42(9): 1639-47, 1999 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-10229632

RESUMO

The conformationally constrained cyclobutane analogues of quisqualic acid (Z)- and (E)-1-amino-3-[2'-(3',5'-dioxo-1',2', 4'-oxadiazolidinyl)]cyclobutane-1-carboxylic acid, compounds 2 and 3, respectively, were synthesized. Both 2 and 3 stimulated phosphoinositide (PI) hydrolysis in the hippocampus with EC50 values of 18 +/- 6 and 53 +/- 19 microM, respectively. Neither analogue stimulated PI hydrolysis in the cerebellum. The effects of 2 and 3 were also examined in BHK cells which expressed either mGluR1a or mGluR5a receptors. Compounds 2 and 3 stimulated PI hydrolysis in cells expressing mGluR5a but not in those cells expressing mGluR1a. The EC50 value for 2 was 11 +/- 4 microM, while that for 3 was 49 +/- 25 microM. Both 2 and 3 did not show any significant effect on cells expressing the mGluR2 and mGluR4a receptors. In addition, neither compound blocked [3H]glutamic acid uptake into synaptosomal membranes, and neither compound was able to produce the QUIS effect as does quisqualic acid. This pharmacological profile indicates that 2 and 3 are selective ligands for the mGluR5a metabotropic glutamic acid receptor.


Assuntos
Ácido Quisquálico/análogos & derivados , Ácido Quisquálico/síntese química , Receptores de Glutamato Metabotrópico/metabolismo , Animais , Animais Recém-Nascidos , Linhagem Celular , Cerebelo/efeitos dos fármacos , Cerebelo/metabolismo , Cristalografia por Raios X , AMP Cíclico/biossíntese , Hipocampo/citologia , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Hidrólise , Técnicas In Vitro , Ligantes , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Fosfatidilinositóis/metabolismo , Ácido Quisquálico/química , Ácido Quisquálico/farmacologia , Ratos , Receptor de Glutamato Metabotrópico 5 , Receptores de AMPA/efeitos dos fármacos , Receptores de AMPA/fisiologia , Estereoisomerismo
17.
J Med Chem ; 42(8): 1441-7, 1999 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-10212130

RESUMO

In the present study, L-prolyl-L-leucyl-glycinamide (1) peptidomimetics 3a-3d and 4a-4d were synthesized utilizing alpha, alpha-disubstituted amino acids. These analogues were designed to explore the conformational effects of constraints at the phi3 and psi3 torsion angles. Constrained conformations were verified by the use of X-ray crystallography and circular dichroism. The effects of Pro-Leu-Gly-NH2 analogues 3a-3d and 4a-4d on enhancing rotational behavior induced by apomorphine in the 6-hydroxydopamine-lesioned animal models of Parkinson's disease were studied. The ability of these peptidomimetics to increase the binding of agonist N-propylnorapomorphine (NPA) to the dopamine D2 receptor was also examined. Extended analogue Pro-Leu-Deg-NH2 was the most active compound of this series. It was 10 times more potent and almost 2 times more effective than 1 in increasing apomorphine-induced rotations (56 +/- 15% at 1.0 mg/kg ip) and in enhancing [3H]NPA specific binding (40%).


Assuntos
Hormônio Inibidor da Liberação de MSH/análogos & derivados , Hormônio Inibidor da Liberação de MSH/síntese química , Peptídeos/química , Receptores Dopaminérgicos/efeitos dos fármacos , Animais , Dicroísmo Circular , Cristalografia por Raios X , Hormônio Inibidor da Liberação de MSH/química , Hormônio Inibidor da Liberação de MSH/farmacologia , Mimetismo Molecular , Atividade Motora/efeitos dos fármacos , Oxidopamina/toxicidade , Estrutura Secundária de Proteína , Ratos , Substância Negra/efeitos dos fármacos
18.
J Med Chem ; 41(14): 2579-87, 1998 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-9651162

RESUMO

Human rhinovirus, the chief cause of the common cold, contains a positive-sense strand of RNA which is translated into a large polyprotein in infected cells. Cleavage of the latter to produce the mature viral proteins required for replication is catalyzed in large part by a virally encoded cysteine proteinase (3Cpro) which is highly selective for -Q approximately GP- cleavage sites. We synthesized peptidyl derivatives of vinylogous glutamine or methionine sulfone esters (e.g., Boc-Val-Leu-Phe-vGln-OR: R = Me, 1; R = Et, 2) and evaluated them as inhibitors of HRV-14 3C protease (3Cpro). Compounds 1 and 2 and several related tetra- and pentapeptide analogues rapidly inactivated 3Cpro with submicromolar IC50 values. Electrospray mass spectrometry confirmed the expected 1:1 stoichiometry of 3Cpro inactivation by 1, 2, and several other analogues. Compound 2 also proved to be useful for active site titration of 3Cpro, which has not been possible heretofore because of the lack of a suitable reagent. In contrast to 1, 2, and congeners, peptidyl Michael acceptors lacking a P4 residue have greatly reduced or negligible activity against 3Cpro, consistent with previously established structure-activity relationships for 3Cpro substrates. Hydrolysis of the P1 vinylogous glutamine ester to a carboxylic acid also decreased inhibitory activity considerably, consistent with the decreased reactivity of acrylic acids vs acrylic esters as Michael acceptors. Incorporating a vinylogous methionine sulfone ester in place of the corresponding glutamine derivative in 1 also reduced activity substantially. Compounds 1 and 2 and several of their analogues inhibited HRV replication in cell culture by 50% at low micromolar concentrations while showing little or no evidence of cytotoxicity at 10-fold higher concentrations. Peptidyl Michael acceptors and their analogues may prove useful as therapeutic agents for pathologies involving cysteine proteinase enzymes.


Assuntos
Antivirais/síntese química , Cisteína Endopeptidases/metabolismo , Inibidores de Cisteína Proteinase/síntese química , Glutamina/síntese química , Peptídeos/síntese química , Rhinovirus/efeitos dos fármacos , Proteínas Virais , Replicação Viral/efeitos dos fármacos , Proteases Virais 3C , Antivirais/química , Antivirais/farmacologia , Linhagem Celular Transformada , Sobrevivência Celular/efeitos dos fármacos , Inibidores de Cisteína Proteinase/química , Inibidores de Cisteína Proteinase/farmacologia , Desenho de Fármacos , Glutamina/análogos & derivados , Glutamina/química , Glutamina/farmacologia , Células HeLa , Humanos , Peptídeos/química , Peptídeos/farmacologia , Rhinovirus/enzimologia , Rhinovirus/fisiologia , Relação Estrutura-Atividade
19.
Biomaterials ; 19(13): 1119-36, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9720896

RESUMO

The use of pressure-sensitive adhesives (PSAs) for skin-contact applications is discussed. The requirements of such adhesives in various applications are examined in detail. Commercially available classes of PSAs used for skin-contact applications are the acrylics, the polyisobutylenes, and the silicones. The main application examined in this review is transdermal drug delivery. The roles played by the PSA in two types of transdermal designs are described. Correlations between in vivo and ex vivo measurements of adhesion are discussed. Also, the reported human studies of various commercially available transdermals are examined critically, with a view to assessing the relative performance capabilities of each type of transdermal design. Finally, a comprehensive listing of currently commercialized transdermals is given.


Assuntos
Sistemas de Liberação de Medicamentos , Pele , Adesivos Teciduais/normas , Acrilatos/normas , Administração Cutânea , Fenômenos Biomecânicos , Humanos , Polienos/normas , Polímeros/normas , Pressão , Vigilância de Produtos Comercializados , Silicones/normas , Propriedades de Superfície , Adesivos Teciduais/efeitos adversos
20.
Org Lett ; 5(19): 3531-3, 2003 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-12967317

RESUMO

[reaction: see text] Synthesis and structural characterization of aromatic core-modified 26 pi hexaphyrin analogues are reported.

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