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1.
Malays J Pathol ; 45(3): 425-440, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38155384

RESUMEN

The onset of obstetric antiphospholipid syndrome (APS) occurs when antiphospholipid antibodies act upon the placenta. During pregnancy, APS exhibits traits such as vascular thrombosis, inflammation, and hindered trophoblast implantation. The involvement of microRNA expression has been proposed as a genetic factor contributing to the syndrome's development. MicroRNAs play a role in regulating gene expression in various cellular processes, including the formation of placental tissue. Therefore, additional research is needed to explore the control of placental miRNA in APS. In this study, we aimed to profile miRNA expressions from placenta tissue of patients with APS. Differentially expressed miRNAs were determined for its targeted genes and pathways. Agilent microarray platform was used to measure placental microRNA expressions between normal placental tissue and those obtained from patients with APS. Differentially expressed miRNAs were detected using GeneSpring GX software 14.2 and sequences were mapped using TargetScan software to generate the predicted target genes. Pathway analysis for the genes was then performed on PANTHER and REACTOME software. Selected miRNAs and their associated genes of interest were validated using qPCR. Microarray findings revealed, 9 downregulated and 21 upregulated miRNAs expressed in placenta of patients with APS. Quantitative expressions of 3 selected miRNAs were in agreement with the microarray findings, however only miR-525-5p expression was statistically significant. Pathway analysis revealed that the targeted genes of differentially expressed miRNAs were involved in several hypothesised signalling pathways such as the vascular endothelial (VE) growth factor (VEGF) and inflammatory pathways. VE-cadherin, ras homolog member A (RHOA) and tyrosine kinase receptor (KIT) showed significant downregulation while Retinoblastoma gene (RET), Dual specificity protein phosphatase 10 (DUSP10) and B-lymphocyte kinase (BLK) genes were significantly upregulated. These preliminary findings suggest the involvement of miRNAs and identified novel associated genes involvement in the mechanism of obstetric APS, particularly through the alteration of vascular-associated regulators and the inflammatory signalling cascade.


Asunto(s)
Síndrome Antifosfolípido , MicroARNs , Humanos , Femenino , Embarazo , Síndrome Antifosfolípido/genética , Placenta/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Transducción de Señal , Fosfatasas de Especificidad Dual/metabolismo , Fosfatasas de la Proteína Quinasa Activada por Mitógenos/metabolismo
2.
Trop Biomed ; 37(2): 333-356, 2020 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33612803

RESUMEN

In addition to the scarcity of forensic entomology baseline data on oviposition of necrophagous insects and completion of their life cycles in the Borneo region, similar data derived from caves remain unreported. Since entomological baseline data can differ from one biogeoclimatic region to another, the lack of such data would limit the practical values of applying entomological evidence in estimating minimum postmortem interval (mPMI). Therefore, this present research that investigated oviposition and completion of life cycles of necrophagous flies infesting rabbit carcasses decomposing in Mount Kapur Cave and its surrounding forest habitat in Kuching, Sarawak merits forensic consideration. In general, 13 taxa of necrophagous flies were identified viz. Hypopygiopsis violacea, Hypopygiopsis fumipennis, Hemipyrellia ligurriens, Hemipyrellia tagaliana, Chrysomya megacephala, Chrysomya villeneuvi, Chrysomya rufifacies, Chrysomya chani, Chrysomya pinguis, Chrysomya nigripes, Ophyra spinigera and Ophyra chalcogaster, as well as unidentified Sarcophagidae. In addition, Hyp. violacea and Hyp. fumipennis were the two earlier necrophagous flies that oviposited in all rabbit carcasses decomposing in both habitats. While all these necrophagous flies were observed infesting carcasses in Mount Kapur Cave, Hem. ligurriens and Hem. tagaliana were not found infesting carcasses in the surrounding forest habitat. Complete life cycles for six and five different necrophagous fly species were successfully observed in Mount Kapur Cave and its surrounding forest habitat, respectively. Significant delay in oviposition, as well as longer durations for completing the life cycles in several necrophagous fly species were observed in Mount Kapur Cave when compared with those of surrounding forest habitat (p < 0.05). These findings deserve consideration as the first ever forensic empirical baseline data on oviposition and completion of life cycles for necrophagous flies in Sarawak as well as in a cave habitat, in view of its practical values for estimating mPMI for forensic practical caseworks.


Asunto(s)
Cuevas , Dípteros/clasificación , Entomología Forense , Animales , Cadáver , Femenino , Larva , Malasia , Oviposición , Conejos
3.
Tropical Biomedicine ; : 333-356, 2020.
Artículo en Inglés | WPRIM (Pacífico Occidental) | ID: wpr-823189

RESUMEN

@#In addition to the scarcity of forensic entomology baseline data on oviposition of necrophagous insects and completion of their life cycles in the Borneo region, similar data derived from caves remain unreported. Since entomological baseline data can differ from one biogeoclimatic region to another, the lack of such data would limit the practical values of applying entomological evidence in estimating minimum postmortem interval (mPMI). Therefore, this present research that investigated oviposition and completion of life cycles of necrophagous flies infesting rabbit carcasses decomposing in Mount Kapur Cave and its surrounding forest habitat in Kuching, Sarawak merits forensic consideration. In general, 13 taxa of necrophagous flies were identified viz. Hypopygiopsis violacea, Hypopygiopsis fumipennis, Hemipyrellia ligurriens, Hemipyrellia tagaliana, Chrysomya megacephala, Chrysomya villeneuvi, Chrysomya rufifacies, Chrysomya chani, Chrysomya pinguis, Chrysomya nigripes, Ophyra spinigera and Ophyra chalcogaster, as well as unidentified Sarcophagidae. In addition, Hyp. violacea and Hyp. fumipennis were the two earlier necrophagous flies that oviposited in all rabbit carcasses decomposing in both habitats. While all these necrophagous flies were observed infesting carcasses in Mount Kapur Cave, Hem. ligurriens and Hem. tagaliana were not found infesting carcasses in the surrounding forest habitat. Complete life cycles for six and five different necrophagous fly species were successfully observed in Mount Kapur Cave and its surrounding forest habitat, respectively. Significant delay in oviposition, as well as longer durations for completing the life cycles in several necrophagous fly species were observed in Mount Kapur Cave when compared with those of surrounding forest habitat (p < 0.05). These findings deserve consideration as the first ever forensic empirical baseline data on oviposition and completion of life cycles for necrophagous flies in Sarawak as well as in a cave habitat, in view of its practical values for estimating mPMI for forensic practical caseworks.

4.
Trop Biomed ; 35(1): 1-9, 2018 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33601771

RESUMEN

The lifestyles of the indigenous people (Orang Asli) of Peninsular Malaysia who traditionally live close to the forest, put them at higher risk of exposure to zoonotic diseases. Leptospirosis has recently emerged as one of the most important diseases of public health concern. Here, we aimed to obtain a baseline data on the level of Leptospira exposure among the 107 Orang Asli volunteers using a recombinant antigen-based ELISA, previously shown to have sensitivity of ~90.0% in comparison to the microscopic agglutination test (MAT). Among the Orang Asli volunteers in this study, 60.7% had IgM against Leptospira and 57.9% were antiLeptospira IgG positive. Of these seropositive individuals, 29.9% had both anti-Leptospira IgM and IgG antibodies. Age was found to be a significant predictor for exposure to Leptospira (P < 0.05) with the younger Orang Asli population more likely to be tested positive for antiLeptospira IgM. The finding of high Leptospira exposure among the Orang Asli volunteers could be due to their socio-economic practices and dependency on the forest for their livelihood. The rapid and sensitive recombinant antigen-based ELISA used in the study, could possibly complement MAT for the epidemiological surveillance of leptospirosis, especially among the underserved populations.

5.
Med J Malaysia ; 63 Suppl A: 71-2, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19024989

RESUMEN

Stress-induced premature senescence (SIPS) model is in vitro model of cellular aging. In this study, apoptosis was evaluated in SIPS model and in replicative senescent fibroblasts. We also compared the activity of senescence-associated beta-galactosidase (SA-beta gal) as a biomarker of cellular aging. Our results suggested that SIPS model and senescent fibroblasts might share similar mechanism of aging and apoptosis pathway.


Asunto(s)
Envejecimiento/fisiología , Apoptosis/efectos de los fármacos , Senescencia Celular/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Fenómenos Fisiológicos de la Piel/efectos de los fármacos , Piel/efectos de los fármacos , beta-Galactosidasa/biosíntesis , Envejecimiento/efectos de los fármacos , Anexinas , Biomarcadores , Circuncisión Masculina , Prepucio/fisiología , Humanos , Peróxido de Hidrógeno , Técnicas In Vitro , Masculino , Modelos Teóricos , beta-Galactosidasa/efectos de los fármacos
6.
Med J Malaysia ; 63 Suppl A: 73-4, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19024990

RESUMEN

Validation of housekeeping gene is important for accurate quantitation of RNA in real time RT-PCR technique. The purpose of this study was to determine the validity of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) as a housekeeping gene for quantitative real time RT-PCR assessment in human skin fibroblast senescent model. The cells were divided into different treatment groups; young (passage 4), senescent (passage 30), treatment with H2O2 and treatment with A-tocotrienol prior to H2O2 treatment. Our results showed that the expression level of GAPDH was constant with different treatment groups. Therefore, we concluded that GAPDH was suitable to be used as housekeeping gene in human skin fibroblast senescent model.


Asunto(s)
Antioxidantes/metabolismo , Senescencia Celular/fisiología , Fibroblastos/fisiología , Gliceraldehído-3-Fosfato Deshidrogenasas/metabolismo , Fenómenos Fisiológicos de la Piel , Piel/enzimología , Tocotrienoles/metabolismo , Fibroblastos/enzimología , Gliceraldehído-3-Fosfato Deshidrogenasas/fisiología , Humanos , Peróxido de Hidrógeno , Técnicas In Vitro , Modelos Teóricos
7.
Singapore Med J ; 49(7): e178-82, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18695852

RESUMEN

A majority of the clinical use of positron emission tomography (PET)-computed tomography (CT) is related to cancer management. Its application in evaluating inflammatory diseases and pyrexia of unknown origin is becoming popular. We reviewed the fluorine-18-fluorodeoxyglucose PET-CT findings of an 80-year-old woman with nonspecific clinical presentation consisting of generalised malaise, moderately high fever and weight loss. Prior CT and magnetic resonance imaging were not helpful in providing a clinical diagnosis. The diagnosis was Horton's arteritis, and the patient responded well to high-dose steroids.


Asunto(s)
Arteritis/diagnóstico , Fluorodesoxiglucosa F18 , Tomografía de Emisión de Positrones/métodos , Anciano de 80 o más Años , Diagnóstico por Imagen/métodos , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Inflamación , Tomografía de Emisión de Positrones/instrumentación , Esteroides/uso terapéutico , Tomografía Computarizada por Rayos X/métodos , Resultado del Tratamiento
8.
Artículo en Ml | WPRIM (Pacífico Occidental) | ID: wpr-629983

RESUMEN

Stress-induced premature senescence (SIPS) model is in vitro model of cellular aging. In this study, apoptosis was evaluated in SIPS model and in replicative senescent fibroblasts. We also compared the activity of senescence-associated beta-galactosidase (SA-beta gal) as a biomarker of cellular aging. Our results suggested that SIPS model and senescent fibroblasts might share similar mechanism of aging and apoptosis pathway.

9.
Acta Biomater ; 1(3): 281-93, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-16701807

RESUMEN

Living cells respond to mechanical stimulation in a variety of ways that affect nearly every aspect of their function. Such responses can range from changes in cell morphology to activation of signaling cascades and changes in cell phenotype. Although the biochemical signaling pathways activated by mechanical stimulus have been extensively studied, little is known of the basic mechanisms by which mechanical force is transduced into a biochemical signal, or how the cell changes its behavior or properties in response to external or internal stresses. One hypothesis is that forces transmitted via individual proteins either at the site of cell adhesion to its surroundings or within the stress-bearing members of the cytoskeleton cause conformational changes that alter their binding affinity to other intracellular molecules. This altered equilibrium state can subsequently either initiate a biochemical signaling cascade or produce more immediate and local structural changes. To understand the phenomena related to mechanotransduction, the mechanics and chemistry of single molecules that form the signal transduction pathways must be examined. This paper presents a range of case studies that seek to explore the molecular basis of mechanical signal sensation and transduction, with particular attention to their macroscopic manifestation in the cell properties, e.g. in focal adhesion remodeling due to local application of force or changes in cytoskeletal rheology and remodeling due to cellular deformation.


Asunto(s)
Citoesqueleto , Mecanotransducción Celular , Transducción de Señal , Animales , Bovinos , Adhesión Celular , Células Cultivadas , Endotelio Vascular/citología
10.
Mech Chem Biosyst ; 1(4): 253-65, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-16783922

RESUMEN

Membrane-bound integrin receptors are linked to intracellular signaling pathways through focal adhesion kinase (FAK). FAK tends to colocalize with integrin receptors at focal adhesions through its C-terminal focal adhesion targeting (FAT) domain. Through recruitment and binding of intracellular proteins, FAs transduce signals between the intracellular and extracellular regions that regulate a variety of cellular processes including cell migration, proliferation, apoptosis and detachment from the ECM. The mechanism of signaling through the cell is of interest, especially the transmission of mechanical forces and subsequent transduction into biological signals. One hypothesis relates mechanotransduction to conformational changes in intracellular proteins in the force transmission pathway, connecting the extracellular matrix with the cytoskeleton through FAs. To assess this hypothesis, we performed steered molecular dynamics simulations to mechanically unfold FAT and monitor how force-induced changes in the molecular conformation of FAT affect its binding to paxillin.


Asunto(s)
Proteína-Tirosina Quinasas de Adhesión Focal/química , Modelos Químicos , Modelos Moleculares , Paxillin/química , Sitios de Unión , Simulación por Computador , Movimiento (Física) , Unión Proteica , Conformación Proteica , Desnaturalización Proteica , Pliegue de Proteína , Estructura Terciaria de Proteína , Estrés Mecánico
11.
Bull World Health Organ ; 63(4): 705-9, 1985.
Artículo en Inglés | MEDLINE | ID: mdl-3878740

RESUMEN

Picornavirus particles and serotype-specific neutralizing antibody were demonstrated in tears collected during early onset of acute haemorrhagic conjunctivitis. Virus particles deposited from tears by airfuge ultracentrifugation and stained with potassium phosphotungstate were easily recognized by electron microscopy. Tear neutralizing antibody in the ultracentrifuged supernatant was detected by the neutralization test in monolayer HeLa cells grown in microtitration plates. The presence of virus particles and specific neutralizing antibody in tear specimens correlated with the serological findings.


Asunto(s)
Conjuntivitis Hemorrágica Aguda/microbiología , Lágrimas/microbiología , Humanos , Métodos , Factores de Tiempo
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