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1.
Mol Med Rep ; 27(2)2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36524356

RESUMO

Placental insufficiency is a common cause of intrauterine growth restriction (IUGR). It affects ~10% of pregnancies and increases fetal and neonatal morbidity and mortality. Although Wnt and Hh pathways are crucial for embryonic development and placentation, their role in the pathology of IUGR is still not sufficiently explored. The present study analyzed the expression of positive regulators of the Wnt pathway, WNT5A and ß­catenin, and the expression of the Hh pathway negative regulator suppressor of fused (SUFU). Immunohistochemical and reverse transcription­quantitative PCR (RT­qPCR) assays were performed on 34 IUGR and 18 placental tissue samples from physiologic singleton­term pregnancies. Epigenetic mechanisms of SUFU gene regulation were also investigated by methylation­specific PCR analysis of its promoter and RT­qPCR analysis of miR­214­3p and miR­378a­5p expression. WNT5A protein expression was higher in endothelial cells of placental villi from IUGR compared with control tissues. That was also the case for ß­catenin protein expression in trophoblasts and endothelial cells and SUFU protein expression in trophoblasts from IUGR placentas. The SUFU gene promoter remained unmethylated in all tissue samples, while miR­214­3p and miR­378a­5p were downregulated in IUGR. The present results suggested altered Wnt and Hh signaling in IUGR. DNA methylation did not appear to be a mechanism of SUFU regulation in the pathogenesis of IUGR, but its expression could be regulated by miRNA targeting.


Assuntos
Retardo do Crescimento Fetal , MicroRNAs , Proteína Wnt-5a , beta Catenina , Feminino , Humanos , Recém-Nascido , Gravidez , beta Catenina/genética , beta Catenina/metabolismo , Células Endoteliais/metabolismo , Retardo do Crescimento Fetal/genética , Retardo do Crescimento Fetal/patologia , MicroRNAs/genética , MicroRNAs/metabolismo , Placenta/metabolismo , Placenta/patologia , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Proteína Wnt-5a/genética , Proteína Wnt-5a/metabolismo
2.
Bosn J Basic Med Sci ; 22(5): 673-682, 2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-35465855

RESUMO

Melanoma is a highly aggressive cancer originating from melanocytes. Its etiopathogenesis is strongly related to genetic, epigenetic, and environmental factors. Melanomas encountered in clinical practice are predominantly sporadic, whereas hereditary melanomas account for approximately 10% of the cases. Hereditary melanomas mainly develop due to mutations in the CDKN2A gene, which encodes two tumor suppressor proteins involved in the cell cycle regulation. CDKN2A, along with CDK4, TERT, and POT1 genes, is a high-risk gene for melanoma. Among the genes that carry a moderate risk are MC1R and MITF, whose protein products are involved in melanin synthesis. The environment also contributes to the development of melanoma. Patients at risk of melanoma should be offered genetic counseling to discuss genetic testing options and the importance of skin UV protection, avoidance of sun exposure, and regular preventive dermatological examinations. Although cancer screening cannot prevent the development of the disease, it allows for early diagnosis when the survival rate is the highest.


Assuntos
Melanoma , Neoplasias Cutâneas , Aconselhamento Genético , Predisposição Genética para Doença , Humanos , Melaninas/genética , Melanoma/etiologia , Melanoma/genética , Fatores de Risco , Neoplasias Cutâneas/genética , Proteínas Supressoras de Tumor/genética , Melanoma Maligno Cutâneo
3.
J Comput Neurosci ; 23(1): 1-19, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17200885

RESUMO

In this paper we prove that both diffusion and the leaky integrators cascade based transport mechanisms have as their inherent property the effect of temporal multi-scaling. The two transport mechanisms are modeled not as convolution based algorithms but as causal physical processes. This implies that propagation of information through a neural map may act as a mechanism for achieving temporal multi-scale analysis in the auditory system. Specifically, we are interested in the effects of such a transport process on the formation and the dynamics of auditory sensory memory. Two temporal models of information propagation are discussed and compared in terms of their ability to model auditory sensory memory effects and the biological plausibility of their structure: the causal diffusion based operator (CD) and the leaky integrator cascade based operator (LINC). We show that temporal multi-scale representations achieved by both models exhibit the effects similar to those of auditory sensory memory (filtering, time delay and binding of information). As regards higher-level functions of auditory sensory memory such as change detection, the LINC operator seems to be a biologically more plausible solution for modeling temporal cortical processing.


Assuntos
Percepção Auditiva/fisiologia , Memória/fisiologia , Processos Mentais/fisiologia , Modelos Neurológicos , Algoritmos , Humanos
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