1,721,190 research outputs found
Neurorestorative role of stem cells in Alzheimer's disease: astrocyte involvement
No full textNeurogenesis is maintained in both neonatal and adult brain, although it is dramatically reduced in aged neurogenic brain region such as the subgranular layer and subventricular zone of the dentate gyrus (DG). Astrocytes play important roles for survival and maintenance of neurons as well as maintenance of neurogenic niche in quiescent state. Aβ can induce astrocyte activation which give rise to produce reactive oxygen species (ROS) and cytotoxic cytokines and chemokines, and subsequently induce neuronal death. Unfortunately, the current therapeutic medicines have been limited to reduce the symptoms and delay the pathogenesis of Alzheimer’s disease (AD), but not to cure it. Stem cells enhance neurogenesis and Aβ clearing as well as improved cognitive impairment. Neurotrophins and growth factors which are produced from both stem cells and astrocytes also have neuroprotective effects via neurogenesis. Secreted factors from both astrocytes and neural stem cells also are influenced in neurogenesis and neuron survival in neurodegenerative diseases. Transplanted stem cells overexpressing neurogenic factors may be an effective and therapeutic tool to enhance neurogenesis for AD.open
Effects of fenvalerate on apoptosis level and GFAP expression in the brain tissue of the pale chub
No full textWe evaluated the level of toxicity by LC50 and investigated the mechanism of brain impairment and GFAP expression
by light and fluorescence microscopes in the pale chub, Zacco platypus, treated with fenvalerate. Survival rate was
decreased according to the rise of fenvalerate concentration, and LC50 concentration was 27.79 μg/L. Apoptosis was
increased according to the rise of fenvalerate concentration by TUNEL assay which determine apoptotic cell death population.
Also, GFAP expression was increased in the periventricular zone. These results suggest that apoptosis might be a
major mechanism to brain impairment of the pale chub by fenvalrerate. Increased GFAP expression in the periventricular
zone would be an index of brain impairment. Taken together, this study might contribute to reveal the pathological
mechanism of fish brain impairment by insecticide of pyrethroid, and to be an useful basic data for preservation of aquatic
ecosystem.open
Immuno-specificity of egg yolk antibodies against bovine rotavirus and bovine coronavirus causing calf diarrhea
No full textThis study was performed to produce specific egg yolk antibodies against bovine rotavirus (BRV) and bovine coronavirus (BCV) that are major pathogens causing diarrhea in calves. Chickens were immunized with BRV and BCV intramuscularly in the breast muscle by injection 5 times at two weeks interval. At 6 weeks after the first immunization of BRV or BCV, cross reactivity of each serum derived from BRV- or BCV-immunized hens was tested. Each serum antibody against BRV or BCV was reacted with only specific BRV or BCV antigens. Serum and egg yolk-antibody titers of hens against BRV or BCVwere highest at 8~12 weeks after first immunization. Specific serum and egg yolk-antibody titers against BRV were about 104,000 and 107,000, respectively, and those against BCV were about 145,000 and 155,000, respectively. Hemagglutination inhibition titers in the immunized egg yolk antibodies against BRV and BCV were 5,120 and 1,280, respectively, and were greater-than or equal to 8 times higher than that in non-immunized control. These results suggested that the immunized egg yolk antibodies could effectively neutralize BRV and BCV.open
Alzheimer's disease and stem cell therapy
No full textThe loss of neuronal cells in the central nervous system may occur in many neurodegenerative diseases. Alzheimer's disease is a common senile disease in people over 65 years, and it causes impairment characterized by the decline of mental function, including memory loss and cognitive impairment, and affects the quality of life of patients. However, the current therapeutic strategies against AD are only to relieve symptoms, but not to cure it. Because there are only a few therapeutic strategies against Alzheimer's disease, we need to understand the pathogenesis of this disease. Cell therapy may be a powerful tool for the treatment of Alzheimer's disease. This review will discuss the characteristics of Alzheimer's disease and various available therapeutic strategies.open
Stem cell therapy in bladder dysfunction: where are we? and where do we have to go?
Full text linkTo date, stem cell therapy for the bladder has been conducted mainly on an experimental basis in the areas of bladder dysfunction. The therapeutic efficacy of stem cells was originally thought to be derived from their ability to differentiate into various cell types. Studies about stem cell therapy for bladder dysfunction have been limited to an experimental basis and have been less focused than bladder regeneration. Bladder dysfunction was listed in MESH as "urinary bladder neck obstruction", "urinary bladder, overactive", and "urinary bladder, neurogenic". Using those keywords, several articles were searched and studied. The bladder dysfunction model includes bladder outlet obstruction, cryoinjured, diabetes, ischemia, and spinal cord injury. Adipose derived stem cells (ADSCs), bone marrow stem cells (BMSCs), and skeletal muscle derived stem cells (SkMSCs) are used for transplantation to treat bladder dysfunction. The main mechanisms of stem cells to reconstitute or restore bladder dysfunction are migration, differentiation, and paracrine effects. The aim of this study is to review the stem cell therapy for bladder dysfunction and to provide the status of stem cell therapy for bladder dysfunction.open
Iron overload-induced calcium signals modulate mitochondrial fragmentation in HT-22 hippocampal neuron cells
No full textIron is necessary for neuronal functions; however, excessive iron accumulation caused by impairment of iron balance could damage neurons. Neuronal iron accumulation has been observed in several neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease. Nevertheless, the precise mechanisms underlying iron toxicity in neuron cells are not fully understood. In this study, we investigated the mechanism underlying iron overload-induced mitochondrial fragmentation in HT-22 hippocampal neuron cells that were incubated with ferric ammonium citrate (FAC). Mitochondrial fragmentation via dephosphorylation of Drp1 (Ser637) and increased apoptotic neuronal death were observed in FAC-stimulated HT-22 cells. Furthermore, the levels of intracellular calcium (Ca2+) were increased by iron overload. Notably, chelation of intracellular Ca2+ rescued mitochondrial fragmentation and neuronal cell death. In addition, iron overload activated calcineurin through the Ca2+/calmodulin and Ca2+/calpain pathways. Pretreatment with the calmodulin inhibitor W13 and the calpain inhibitor ALLN attenuated iron overload-induced mitochondrial fragmentation and neuronal cell death. Therefore, these findings suggest that Ca2+-mediated calcineurin signals are a key player in iron-induced neurotoxicity by regulating mitochondrial dynamics. We believe that our results may contribute to the development of novel therapies for iron toxicity related neurodegenerative disordersopen
Effects of Dietary Supplementation of Illite on Humoral Immunity against Salmonella typhimurium Flagella Antigen in Laying Hens
No full textThis study was carried out to investigate dietary effects of illite on humoral immune response against Salmonella
typhimurium flagella in Hyline Brown laying hens. Total of twenty eight 36-week-old hens were divided into two groups; The first
was fed commercial diet as control and the other was fed diet containing 2 % illite. Each group was divided into 2 sub-groups
and then performed immunization of Salmonella flagella with different adjuvants which were Freund’s adjuvant and croton oil. The
rates of egg-production in all groups were normal range but no difference was found between illite-treated and untreated groups.
The serum antibody titers of Freund’s adjuvant-used subgroup in illite fed groups were significantly increased, especially from 6-
to 9-week after 1st immunization compared to those of control groups (p<0.05). And the antibody titers of croton oil-used subgroup
in illite-fed groups were also significantly increased, especially at 4-, 6- and 7-week (p<0.05). The results demonstrated that the
feeding illite stimulated the immune response against S. typhimurium flagella antigen in laying hens and suggest that the
supplementation of illite to the poultry diets may support protective effects against bacterial infections such as Salmonellosis.open
Comparison of surgical methods of transient middle cerebral artery occlusion between rats and mice
No full textRodent models of focal cerebral ischemia that do not require craniotomy have been developed by intraluminal suture middle cerebral artery occlusion (MCAo). Mouse MCAo models have been widely used and extended to genetic studies of cell death or recovery mechanisms. Therefore, we compared surgery-related parameters and techniques between such rats and mice. In rodent MCAo models, has to be considered body temperature during the operative period, as well as the need for the use of a standardized tip in terms of the outer diameter of probes. Induction of focal cerebral ischemia was measured by neurological dysfunction parameters. Our methods could induce stable moderate-severity ischemic brain injury models and histological alteration at 24 hr after MCAo surgery. Moreover approximately 80% (rats) and 85% (mice) survival ratios were shown indicating with model engineering success. Finally, we described and compared major parameters between rats and mice, including probe size, thread insert length, operation and occlusion periods, and differences in the procedures.open
Autophagy contributes to retardation of cardiac growth in diabetic rats
No full textDiabetes mellitus is a major predictor of heart failure, although the mechanisms by which the disease
causes cardiomyopathy are not well understood. The purpose of this study was to determine whether
prolonged exposure of cardiomyocytes to high glucose concentrations induces autophagy and contributes
to cardiomyopathy. Interestingly, there were no differences in the autophagic activation produced by
different glucose concentrations. However, cell viability was decreased by high glucose. In the diabetic
rats, we found a higher level of microtubule-associated protein light chain 3 (LC3) expression and a
reduction in the size of the left ventricle (LV) (P<0.05) caused by growth retardation, suggesting activated
autophagy. Our in vitro findings indicate that hyperglycemic oxidative stress induces autophagy, and our
in vivo studies reveal that autophagy is involved in the progression of pathophysiological remodeling of
the heart. Taken together, the studies suggest that autophagy may play a role in the pathogenesis of
juvenile diabetic cardiomyopathy.open
Morphological changes of bones and joints with rheumatoid arthritis and osteoarthritis
No full textArthritis is a common disease in aged people, and is clinically divided into rheumatoid arthritis (RA) and osteoarthritis (OA). Although common symptoms such as pain are present, the underlying pathological mechanisms are slightly different. Therefore, the objectives of the present study were to compare joint damage induced by RA and OA by analyzing the major morphological and molecular differences, and to propose a suitable therapeutic intervention based on the pathophysiological conditions of bones and joints. For the RA animal model, 8-week-old DBA1/J mice were immunized with bovine type Ⅱ collagen emulsified in complete Freund's adjuvant (CFA). Normal C57BL/6 mice (over 2 years of age) were used for OA. The clinical arthritis score was calculated using a subjective scoring system, and paw thicknesses were measured using calipers. The serum TNF α level was analyzed using an ELISA kit. Micro-CT was used to identify pathological characteristics and morphological changes. In collagen-induced RA mice, there were increased ankle joint volumes and clinical scores (p less than 0.01). The concentration of TNF α was significantly increased from 3 to 7 weeks after immunization. Micro-CT images showed trabecular bone destruction, pannus formation, and subchondral region destruction in RA mice. OA among aged mice showed narrowed joint spaces and breakdown of articular cartilage. This study suggests that a careful therapeutic intervention between RA and OA is requiropen
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