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1.
Cell Rep ; 43(6): 114291, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38823017

RESUMO

Atoh7 is transiently expressed in retinal progenitor cells (RPCs) and is required for retinal ganglion cell (RGC) differentiation. In humans, a deletion in a distal non-coding regulatory region upstream of ATOH7 is associated with optic nerve atrophy and blindness. Here, we functionally interrogate the significance of the Atoh7 regulatory landscape to retinogenesis in mice. Deletion of the Atoh7 enhancer structure leads to RGC deficiency, optic nerve hypoplasia, and retinal blood vascular abnormalities, phenocopying inactivation of Atoh7. Further, loss of the Atoh7 remote enhancer impacts ipsilaterally projecting RGCs and disrupts proper axonal projections to the visual thalamus. Deletion of the Atoh7 remote enhancer is also associated with the dysregulation of axonogenesis genes, including the derepression of the axon repulsive cue Robo3. Our data provide insights into how Atoh7 enhancer elements function to promote RGC development and optic nerve formation and highlight a key role of Atoh7 in the transcriptional control of axon guidance molecules.


Assuntos
Axônios , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Elementos Facilitadores Genéticos , Células Ganglionares da Retina , Animais , Células Ganglionares da Retina/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Camundongos , Axônios/metabolismo , Elementos Facilitadores Genéticos/genética , Neurogênese/genética , Proteínas do Tecido Nervoso/metabolismo , Proteínas do Tecido Nervoso/genética , Receptores Imunológicos/metabolismo , Receptores Imunológicos/genética , Nervo Óptico/metabolismo , Diferenciação Celular , Regulação da Expressão Gênica no Desenvolvimento , Retina/metabolismo , Camundongos Endogâmicos C57BL , Proteínas Roundabout , Receptores de Superfície Celular
2.
Mol Aspects Med ; 94: 101219, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37839232

RESUMO

Glaucoma is a neurodegenerative eye disease that causes permanent vision impairment. The main pathological characteristics of glaucoma are retinal ganglion cell (RGC) loss and optic nerve degeneration. Glaucoma can be caused by elevated intraocular pressure (IOP), although some cases are congenital or occur in patients with normal IOP. Current glaucoma treatments rely on medicine and surgery to lower IOP, which only delays disease progression. First-line glaucoma medicines are supported by pharmacotherapy advancements such as Rho kinase inhibitors and innovative drug delivery systems. Glaucoma surgery has shifted to safer minimally invasive (or microinvasive) glaucoma surgery, but further trials are needed to validate long-term efficacy. Further, growing evidence shows that adeno-associated virus gene transduction and stem cell-based RGC replacement therapy hold potential to treat optic nerve fiber degeneration and glaucoma. However, better understanding of the regulatory mechanisms of RGC development is needed to provide insight into RGC differentiation from stem cells and help choose target genes for viral therapy. In this review, we overview current progress in RGC development research, optic nerve fiber regeneration, and human stem cell-derived RGC differentiation and transplantation. We also provide an outlook on perspectives and challenges in the field.


Assuntos
Glaucoma , Doenças Neurodegenerativas , Doenças do Nervo Óptico , Humanos , Animais , Glaucoma/tratamento farmacológico , Glaucoma/patologia , Células Ganglionares da Retina/patologia , Doenças do Nervo Óptico/terapia , Doenças do Nervo Óptico/patologia , Progressão da Doença , Doenças Neurodegenerativas/patologia , Modelos Animais de Doenças
3.
J Healthc Eng ; 2022: 6462657, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35047155

RESUMO

BACKGROUND: Even in today's environment, when there is a plethora of information accessible, it may be difficult to make appropriate choices for one's well-being. Data mining, machine learning, and computational statistics are among the most popular arenas of training today, and they are all aimed at secondary empowered person in making good decisions that will maximize the outcome of whatever working area they are involved with. Because the degree of rise in the number of patient roles is directly related to the rate of people growth and lifestyle variations, the healthcare sector has a significant need for data processing services. When it comes to cancer, the prognosis is an expression that relates to the possibility of the patient surviving in general, but it may also be used to describe the severity of the sickness as it will present itself in the patient's future timeline. Methodology. The proposed technique consists of three stages: input data acquisition, preprocessing, and classification. Data acquisition consists of input raw data which is followed by preprocessing to eliminate the missed data and the classification is carried out using ensemble classifier to analyze the stages of cancer. This study explored the combined influence of the prominent labels in conjunction with one another utilizing the multilabel classifier approach, which is successful. Finally, an ensemble classifier model has been constructed and experimentally validated to increase the accuracy of the classifier model, which has been previously shown. The entire performance of the recommended and tested models demonstrates a steady development of 2% to 6% over the baseline presentation on the baseline performance. RESULTS: Providing a good contribution to the general health welfare of noncommercial potential workers in the healthcare sector is an opportunity provided by this recommended job outcome. It is anticipated that alternative solutions to these constraints, as well as automation of the whole process flow of all five phases, will be the key focus of the work to be carried out shortly. Predicting health status of employee in industry or information trends is made easier by these data patterns. The proposed classifier achieves the accuracy rate of 93.265%.


Assuntos
Algoritmos , Mineração de Dados , Atenção à Saúde , Humanos , Inteligência , Aprendizado de Máquina
4.
Psychopharmacology (Berl) ; 239(2): 573-587, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35072759

RESUMO

Global cerebral ischemia/reperfusion (I-R) injury often results in an irreparable brain damage like behavioral impairment and neuronal death. This neurological complication involves diverse intricate pathological mechanisms like oxidative stress, inflammation, and apoptosis. Recently, the therapeutic value of plant-based polyphenols has gained researcher's attention. The present study focused on the putative neuroprotective role of negundoside on behavioral and oxidative stress status in an experimental model of global cerebral ischemia and reperfusion-induced brain injury. Negundoside was isolated from the leaves of Vitex negundo Linn. by chromatography for investigating its possible neurobehavioral and neuropharmacological implications. Healthy Balb/C mice of either sex were subjected to 10 min of global cerebral ischemia (GCI) followed by 24-h reperfusion. Mice were pre-treated intraperitoneally with negundoside at varying doses (1, 3, 5, 10, and 15 mg/kg) 60 min before the induction of GCI. Mice were later subjected to a battery of behavioral tests for evaluating memory-related and motor abilities. Elevated plus maze (EPM) was used to determine the anxiety levels and short-term memory whereas motor abilities were evaluated by inclined beam-walking test, rotarod, and lateral push test. TBARS and reduced glutathione (GSH) content in brains were analyzed spectrophotometrically as oxidative stress markers. Behavioral study revealed enhanced anxiety-related responses and motor deficits in I-R injured mice. Additionally, GSH and TBARS levels were found to be altered following I-R-induced neuronal injury. Contrastingly, negundoside administration was able to alleviate the behavioral and biochemical alterations to the normal levels. Together, our findings provide preliminary evidence of neuroprotective role of negundoside against global cerebral ischemia and reperfusion-induced behavioral dysfunction and oxidative damage in mice brain.


Assuntos
Isquemia Encefálica , Fármacos Neuroprotetores , Traumatismo por Reperfusão , Vitex , Animais , Isquemia Encefálica/tratamento farmacológico , Camundongos , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo , Traumatismo por Reperfusão/tratamento farmacológico
5.
Psychopharmacology (Berl) ; 238(9): 2485-2502, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34050381

RESUMO

BACKGROUND: Chronic inorganic arsenic (iAs) exposure induces deleterious effects on CNS including oxidative stress, cognitive deficits and altered brain neurochemistry. Little is known about the association between iAs and estrogen receptor expression in brain regions. AIMS AND OBJECTIVES: Owing to the neuroprotective and estrogenic activities of resveratrol (RES), we examined the combined effects of arsenic trioxide (As2O3) and RES on neurobehavioural functions, estrogen signalling and associated neurochemical changes in mouse hippocampus. MATERIALS AND METHODS: As2O3 alone (2 and 4 mg/kg bw) or along with RES (40 mg/kg bw) was administered orally for 45 days to adult female mice. From days 33 to 45, open field, elevated plus maze and Morris water maze tests were conducted to evaluate locomotion, anxiety and learning and memory. On day 46, animals were euthanized and brain tissue and hippocampi obtained therefrom were processed for atomic absorption spectrophotometry and western blotting respectively. RESULTS: As2O3 alone exposure resulted in enhanced anxiety levels, reduced locomotion and impaired learning and memory. As2O3-induced behavioural deficits were accompanied by downregulation of estrogen receptor (ERα) expression with a concomitant reduction of BDNF and NMDAR 2B levels in the hippocampus. However, the behavioural alterations and expression of these markers were restored in RES-supplemented mice. Moreover, a dose-dependent iAs accumulation was observed in serum and brain tissues of mice receiving As2O3 alone whereas simultaneous administration of As2O3 with RES facilitated iAs efflux. CONCLUSIONS: These results suggest that reduced ERα expression with associated downregulation of BDNF and NMDAR 2B levels could be a mechanism by which iAs induces cognitive impairment; hence, the modulation of estrogen-NMDAR-BDNF pathway by RES represents a potential avenue to recover behavioural deficits induced by this neurotoxin.


Assuntos
Arsênio , Disfunção Cognitiva , Animais , Fator Neurotrófico Derivado do Encéfalo , Cognição , Disfunção Cognitiva/induzido quimicamente , Estrogênios , Feminino , Hipocampo , Aprendizagem em Labirinto , Camundongos , Resveratrol/farmacologia
6.
Anat Cell Biol ; 53(3): 355-365, 2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-32929054

RESUMO

Since, oxidative stress has been suggested as one of the mechanisms underlying arsenic-induced toxicity, the present study focused on the role of antioxidant (curcumin) supplementation on behavioral, biochemical, and morphological alterations with context to mice hippocampus (CA1) following arsenic trioxide (As2O3) administration. Healthy male Swiss albino mice were divided into control and experimental groups. As2O3 (2 mg/kg bw) alone or along with curcumin (100 mg/kg bw) was administered to experimental groups by oral route for 45 days whereas the control groups received either no treatment or vehicle for curcumin. Animals were subjected to behavioral study towards the end of the experimental period (day 33-45). On day 46, the brain samples were obtained and subjected either to immersion fixation (for morphometric observations) or used afresh for biochemical test. Behavioral tests (open field, elevated plus maze, and Morris water maze) revealed enhanced anxiety levels and impairment of cognitive functions in As2O3 alone treated groups whereas a trend of recovery was evident in mice simultaneously treated with As2O3 and curcumin. Morphological observations showed noticeable reduction in stratum pyramidale thickness (CA1), along with decrease in density and size of pyramidal neurons in As2O3 alone exposed group as compared to As2O3+Cu co-treated group. Hippocampal glutathione levels were found to be downregulated in animals receiving As2O3 as against the levels of controls and curcumin supplemented animals, thereby, suggestive of beneficial role of curcumin on As2O3 induced adverse effects.

7.
Sultan Qaboos Univ Med J ; 17(1): e106-e108, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28417038

RESUMO

The brachial plexus innervates the upper extremities. While variations in the formation of the brachial plexus and its terminal branches are quite common, it is uncommon for the median nerve to innervate the muscles of the arm. During the dissection of an elderly male cadaver at the Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India, in 2016, the coracobrachialis muscle was found to be supplied by a direct branch from the lateral root of the median nerve and the musculocutaneous nerve was absent. The branches of the median nerve supplied the biceps brachii and brachialis muscles and the last branch continued as the lateral cutaneous nerve of the forearm. These variations may present atypically in cases of arm flexor paralysis or sensory loss on the lateral forearm. Knowledge of these variations is important in surgeries and during the administration of regional anaesthesia near the shoulder joint and upper arm.


Assuntos
Nervo Mediano/anormalidades , Músculo Esquelético/inervação , Nervo Musculocutâneo/anormalidades , Idoso , Plexo Braquial/anatomia & histologia , Cadáver , Dissecação , Antebraço/inervação , Humanos , Masculino
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