Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
1.
Nat Commun ; 15(1): 3734, 2024 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-38702312

RESUMEN

Mutations in DNA damage response (DDR) factors are associated with human infertility, which affects up to 15% of the population. The DDR is required during germ cell development and meiosis. One pathway implicated in human fertility is DNA translesion synthesis (TLS), which allows replication impediments to be bypassed. We find that TLS is essential for pre-meiotic germ cell development in the embryo. Loss of the central TLS component, REV1, significantly inhibits the induction of human PGC-like cells (hPGCLCs). This is recapitulated in mice, where deficiencies in TLS initiation (Rev1-/- or PcnaK164R/K164R) or extension (Rev7 -/-) result in a > 150-fold reduction in the number of primordial germ cells (PGCs) and complete sterility. In contrast, the absence of TLS does not impact the growth, function, or homeostasis of somatic tissues. Surprisingly, we find a complete failure in both activation of the germ cell transcriptional program and in DNA demethylation, a critical step in germline epigenetic reprogramming. Our findings show that for normal fertility, DNA repair is required not only for meiotic recombination but for progression through the earliest stages of germ cell development in mammals.


Asunto(s)
Desmetilación del ADN , Reparación del ADN , ADN Polimerasa Dirigida por ADN , Células Germinativas , Animales , Femenino , Humanos , Masculino , Ratones , Daño del ADN , ADN Polimerasa Dirigida por ADN/metabolismo , ADN Polimerasa Dirigida por ADN/genética , Epigénesis Genética , Células Germinativas/metabolismo , Meiosis/genética , Ratones Noqueados , Nucleotidiltransferasas/metabolismo , Nucleotidiltransferasas/genética , Antígeno Nuclear de Célula en Proliferación/metabolismo , Síntesis Translesional de ADN
2.
Patterns (N Y) ; 5(3): 100932, 2024 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-38487806

RESUMEN

Along with propagating the input toward making a prediction, Bayesian neural networks also propagate uncertainty. This has the potential to guide the training process by rejecting predictions of low confidence, and recent variational Bayesian methods can do so without Monte Carlo sampling of weights. Here, we apply sample-free methods for wildlife call detection on recordings made via passive acoustic monitoring equipment in the animals' natural habitats. We further propose uncertainty-aware label smoothing, where the smoothing probability is dependent on sample-free predictive uncertainty, in order to downweigh data samples that should contribute less to the loss value. We introduce a bioacoustic dataset recorded in Malaysian Borneo, containing overlapping calls from 30 species. On that dataset, our proposed method achieves an absolute percentage improvement of around 1.5 points on area under the receiver operating characteristic (AU-ROC), 13 points in F1, and 19.5 points in expected calibration error (ECE) compared to the point-estimate network baseline averaged across all target classes.

3.
Genomics ; 114(4): 110399, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35680011

RESUMEN

Different human races across the globe responded in a different way to the SARS-CoV-2 infection leading to different disease severity. Therefore, it is anticipated that host genetic factors have a straight association with the COVID-19. We identified a total 6, 7, and 6 genomic loci for deceased-recovered, asymptomatic-recovered, and deceased-asymptomatic group comparison, respectively. Unfavourable alleles of the markers nearby the genes which are associated with lung and heart diseases such as Tumor necrosis factor superfamily (TNFSF4&18), showed noteworthy association with the disease severity and outcome for the COVID-19 patients in the western Indian population. The markers found with significant association with disease prognosis or recovery are of value in determining the individual's response to SARS-CoV-2 infection and can be used for the risk prediction in COVID-19. Besides, GWAS study in other populations from India may help to strengthen the outcome of this study.


Asunto(s)
COVID-19 , Estudio de Asociación del Genoma Completo , Alelos , Pueblo Asiatico , COVID-19/diagnóstico , COVID-19/genética , Humanos , India , Ligando OX40/genética , SARS-CoV-2 , Factores de Necrosis Tumoral/genética
4.
J Minim Access Surg ; 10(1): 27-33, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24501506

RESUMEN

OBJECTIVES: To assess the feasibility of laparoscopic surgery in cases of moderate-severe endometriosis. MATERIALS AND METHODS: A prospective study was carried out in a tertiary centre over a period of 2 years. Moderate to severe endometriosis was defined by revised American fertility society (rAFS) classification (41 patients). Various procedures were done to provide symptomatic relief. Feasibility of laparoscopic surgery and various patient parameters were analysed. RESULTS: Various procedures like adhesiolysis in POD, excision of endometriomas, resection of endometriotic nodules in the recto-vaginal septum, ureterolysis and total laparoscopic hysterectomy with/ without oophorectomy were done. Majority of patients underwent cystectomy for endometriomas (53.6%) or adhesiolysis with excision of endometriotic nodule (36.5%). Total laparoscopic hysterectomy with or without ooperectomy was done in 31.7% patients. Of the total 9 patients with primary infertility and moderate-severe endometriosis, 5 patients (55.5%) conceived after surgery. CONCLUSION: There is good evidence that in experienced hands laparoscopic surgery helps in long-term symptomatic relief, improves pregnancy rates and reduces recurrence of disease with largely avoiding complications.

5.
Bioorg Med Chem Lett ; 23(3): 834-8, 2013 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-23265878

RESUMEN

We report our attempts at improving the oral efficacy of low-nanomolar inhibitors of xanthine oxidase from isocytosine series through chemical modifications. Our lead compound had earlier shown good in vivo efficacy when administered intraperitoneally but not orally. Several modifications are reported here which achieved more than twofold improvement in exposure. A compound with significant improvement in oral efficacy was also obtained.


Asunto(s)
Citosina/análogos & derivados , Inhibidores Enzimáticos/química , Xantina Oxidasa/antagonistas & inhibidores , Administración Oral , Animales , Dominio Catalítico , Citosina/administración & dosificación , Citosina/química , Citosina/farmacología , Activación Enzimática/efectos de los fármacos , Inhibidores Enzimáticos/administración & dosificación , Inhibidores Enzimáticos/farmacología , Concentración 50 Inhibidora , Modelos Animales , Modelos Moleculares , Estructura Molecular , Ratas
6.
Bioorg Med Chem Lett ; 22(24): 7543-6, 2012 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-23122864

RESUMEN

Structure-activity relationship studies were carried out for lead generation following structure-guided design approach from an isocytosine scaffold identified earlier for xanthine oxidase inhibition. A 470-fold improvement in in vitro IC(50) was obtained in the process. Five most potent compounds with nanomolar IC(50) values were selected for pharmacokinetics and in vivo experiments. The best compound showed good in vivo activity when administered intraperitoneally but was not active by oral route. The results suggest that improvement in oral exposure could improve the in vivo efficacy of this series.


Asunto(s)
Citosina/análogos & derivados , Modelos Animales de Enfermedad , Diseño de Fármacos , Inhibidores Enzimáticos/farmacología , Hiperuricemia/tratamiento farmacológico , Xantina Oxidasa/antagonistas & inhibidores , Administración Oral , Animales , Citosina/administración & dosificación , Citosina/síntesis química , Citosina/farmacología , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/administración & dosificación , Inhibidores Enzimáticos/síntesis química , Hiperuricemia/enzimología , Hiperuricemia/metabolismo , Modelos Moleculares , Estructura Molecular , Ratas , Ratas Sprague-Dawley , Ratas Wistar , Relación Estructura-Actividad , Factores de Tiempo , Xantina Oxidasa/metabolismo
7.
J Assoc Physicians India ; 60: 72-4, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23029752

RESUMEN

Peripartum cardiomyopathy as a diagnosis needs to be considered in antenatal and immediate postpartum women with clinical features of cardiac failure. As more and more women at increasing age go for assisted reproduction, screening for risk factors needs to be done. Treatment involves coordination between cardiologist and obstetrician as both the patient's cardiac status and well being of the baby needs to be considered. In this case report we present an elderly Primigravida, conceived with in-vitro fertilization (donor oocytes) who developed unexplained cardiac failure post LSCS.


Asunto(s)
Cardiomiopatías/fisiopatología , Complicaciones Cardiovasculares del Embarazo/fisiopatología , Trastornos Puerperales/fisiopatología , Adulto , Cardiomiopatías/tratamiento farmacológico , Cesárea , Femenino , Fertilización In Vitro , Humanos , Embarazo , Complicaciones Cardiovasculares del Embarazo/tratamiento farmacológico , Disfunción Ventricular Izquierda/tratamiento farmacológico , Disfunción Ventricular Izquierda/fisiopatología
8.
Bioorg Med Chem ; 20(9): 2930-9, 2012 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-22483591

RESUMEN

In recent years, xanthine oxidase has emerged as an important target not only for gout but also for cardiovascular and metabolic disorders involving hyperuricemia. Contrary to popular belief, recent clinical trials with uricosurics have demonstrated that enhanced excretion of uric acid is, by itself, not adequate to treat hyperuricemia; simultaneous inhibition of production of uric acid by inhibition of xanthine oxidase is also important. Virtual screening of in-house synthetic library followed by in vitro and in vivo testing led to the identification of a novel scaffold for xanthine oxidase inhibition. In vitro activity results corroborated the results from molecular docking studies of the virtual screening hits. The isocytosine scaffold maintains key hydrogen bonding and pi-stacking interactions in the deep end of the xanthine-binding pocket, which anchors it in an appropriate pose to inhibit binding of xanthine and shows promise for further lead optimization using structure-based drug design approach.


Asunto(s)
Simulación por Computador , Citosina/análogos & derivados , Inhibidores Enzimáticos/química , Xantina Oxidasa/antagonistas & inhibidores , Animales , Citosina/síntesis química , Citosina/química , Citosina/farmacología , Activación Enzimática/efectos de los fármacos , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Hiperuricemia/inducido químicamente , Hiperuricemia/tratamiento farmacológico , Masculino , Ácido Oxónico/farmacología , Ácido Oxónico/toxicidad , Ratas , Ratas Sprague-Dawley , Relación Estructura-Actividad , Xantina Oxidasa/metabolismo
9.
Am J Clin Pathol ; 128(4): 585-9, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17875509

RESUMEN

The present study aimed to retrospectively evaluate the usefulness of cell counter-based parameters and formulas in beta-thalassemia trait (BTT) detection. The study included 170 BTT cases (hemoglobin [Hb]A(2) >4.0% [0.04]) and 30 non-BTT cases (HbA(2), 2.3%-3.5% [0.02-0.04]). Depending on the hemoglobin level and iron deficiency, the BTT group was further classified into classic BTT (n = 112) and BTT with iron deficiency anemia (n = 58). The RBC count, MCH, MCV, RDW, and Shine and Lal, Mentzler, Srivastava, England and Fraser, Ricerca, and Green indexes were applied. For the first time in the population of India, these 10 cell counter parameters and manual formulas were compared with high-performance liquid chromatography-derived HbA2 levels for deriving a cost-effective alternative method; and receiver operating characteristic curves were applied. We found that the Shine and Lal, Srivastava, and Mentzler indexes, MCV, and MCH have better discriminative function than the RBC count and red cell distribution width and their related formulas.


Asunto(s)
Anemia Ferropénica/diagnóstico , Recuento de Células Sanguíneas/métodos , Hemoglobina A2/análisis , Talasemia beta/diagnóstico , Anemia Ferropénica/epidemiología , Anemia Ferropénica/genética , Recuento de Células Sanguíneas/instrumentación , Comorbilidad , Hemoglobina A2/genética , Humanos , India , Valor Predictivo de las Pruebas , Prevalencia , Estudios Retrospectivos , Sensibilidad y Especificidad , Talasemia beta/epidemiología , Talasemia beta/genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA