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Aim To explore the effect of resveratrol (RSV) on necrotizing enterocolitis (NEC) mouse pyroptosis and its regulatory mechanism. Methods Five-day-old C57BL/6 newborn mice were selected and divided into control group (Control), NEC model group, and RSV treatment group (RSV). The mice in the control group were given normal breastfeeding, while those in the NEC group were given hypoxia stimulation and artificial feeding accompanied by lipopolysaccharide intervention, and the mice in the RSV treatment group were given RSV gavage (1 mg · kg
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Aim To investigate changes in expression of steroid receptor coactivator-1 ( SRC-1) gene during the differentiation of mouse Neural Stem Cells (NSCs) in vitro. Methods Primary NSCs were obtained from cerebral cortex of neonatal mouse aged 1 ~ 3 days mechanically and enzymatically. The neurospheres were cultured in vkro, The neurosphere cells were induced to differentiate into neurons and astrocytes by serum after primary and passage culture. The cultured NSCs were identified by neurospheric morphology and Nestin immunofluorescence assay; Neurons and astrocytes were recognized respectively by specific antibodies to detect the cell types on days 3 and 9 of differentiation; The expression of SRC-1 gene mRNA and protein were detected by RT-qPCR and Western blotting on days 0, 3 and 9 of differentiation. Results Nestin-positive NSCs were observed in cultured neurospheres derived from cerebral cortex of neonatal mouse in vitro. During the process of differentiation, neurons were the main cells on day 3 and astrocytes were the, main ones on day 9. Compared with day 0, SRC-1 expression increased on day 3 and decreased on day 9 significantly. Conclusion NSCs could be isolated from cerebral cortex of neonatal mouse and cultured well in vilro. During the differentiation of NSCs, thdre were significant changes in SRC-1 expression, which was the highest in neurons, followed by NSCs and astrocytes.
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Abstract Background and objectives: Developing brain is more vulnerable to environmental risk than is the developed brain. We evaluated the effects of repeated exposure to different concentrations of sevoflurane on the neonatal mouse hippocampus using stereological methods. Methods: Eighteen neonatal male mice were randomly divided into three groups. Group A, inhaled sevoflurane at a concentration of 1.5%; Group B, inhaled sevoflurane at a concentration of 3%; and Group C (control group), inhaled only 100% oxygen. Treatments were applied for 30 min a day for 7 consecutive days. The hippocampal volume, dendrite length, number of neurons, and number of glial cells were evaluated in each group using stereological estimations. Results: We identified a ∼2% reduction in the volume of the hippocampus in Group A compared to Group C. Mean hippocampal volume was ∼11% smaller in Group B than it was in Group C. However, these differences in hippocampal volume between the groups were not statistically significant (p > 0.05 for all). As for the number of neurons, we found significantly fewer neurons in Group A (∼29% less) and Group B (∼43% less) than we did in Group C (p < 0.05 for both). The dendrite length was ∼8% shorter in Group A and ∼11% shorter in Group B than it was in Group C. Conclusions: Repeated exposure to sevoflurane, regardless of the concentration, reduced the volume of the neonatal mouse hippocampus, as well as the number of neurons and dendrite length.
Resumo Justificativa e objetivos: O cérebro em desenvolvimento é mais vulnerável ao risco ambiental do que o cérebro já desenvolvido. Avaliamos os efeitos da exposição repetida a diferentes concentrações de sevoflurano sobre o hipocampo de ratos neonatos com o uso de métodos estereológicos. Métodos: Dezoito ratos neonatos foram divididos aleatoriamente em três grupos. O Grupo A foi submetido à inalação de sevoflurano a uma concentração de 1,5%; o Grupo B foi submetido à inalação de sevoflurano a uma concentração de 3%; o Grupo C (controle) foi submetido à inalação de apenas oxigênio a 100%. Os tratamentos foram aplicados durante 30 minutos por dia, durante sete dias consecutivos. Volume do hipocampo, comprimento do dendrito, número de neurônios e número de células gliais foram avaliados em cada grupo com o uso de estimativas estereológicas. Resultados: Identificamos uma redução de ∼2% no volume do hipocampo no Grupo A em comparação com o Grupo C. O volume médio do hipocampo foi ∼11% menor no Grupo B do que no Grupo C. Entretanto, essas diferenças no volume do hipocampo entre os grupos não foram estatisticamente significativas (p > 0,05 para todos). Quanto ao número de neurônios, encontramos um número significativamente menor de neurônios no Grupo A (∼29% menos) e no Grupo B (∼43% menos) do que no Grupo C (p < 0,05 para ambos). O comprimento do dendrito foi ∼8% menor no Grupo A e ∼1% menor no Grupo B que no Grupo C. Conclusões: A exposição repetida ao sevoflurano, independentemente da concentração, reduziu o volume do hipocampo neonatal de camundongos, bem como o número de neurônios e o comprimento dos dendritos.
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Animals , Male , Anesthetics, Inhalation/administration & dosage , Sevoflurane/administration & dosage , Hippocampus/drug effects , Random Allocation , Dose-Response Relationship, Drug , Animals, Newborn , MiceABSTRACT
OBJECTIVE: To investigate the effect of γ-secretase inhibitor DAPT in inflammation-induced brain white matter injury in neonatal mice. METHODS: Sixty C57BL/10J neonatal mice are randomly divided into control group, control+DAPT (10 mg•kg-1) group, inflammation (LPS) group, LPS+DAPT group (inflammation exposure after 10 mg•kg-1 DAPT treatment). All neonatal mice were killed and brain was removed to the following observation and detection:at P5, the mRNA expression variation of IL-1β, IL-8,TNF-α,Hes1 and NICD by Real-time PCR methods. Oligodendrocytes were identified by immunofluorescence staining. Myelin basic protein (MBP) protein expression was detected by Western blot assay. RESULTS: LPS group showed brain injury characterized by inhibition of brain development. There were significant differences in mRNA expression of IL-1β, IL-8, TNF-α, Hes1 and NICD between LPS+DAPT group and LPS group (P<0.05), and the mRNA expression of IL-1β, IL-8,TNF-α,Hes1 and NICD in inflammation-treated were significantly increased than control group (P<0.05). The results showed more expression of MBP in LPS+DAPT group compared with LPS group (P<0.05). Compared with the blank control group, which was obviously decreased after 48 h of inflammation (P<0.05).CONCLUSION: Inflammation leads to abnormal of notch signal expression in neonatal mice, and which is shows inflammation involved in brain damage.Its mechanism is probably associated with the maturation of oligodendrocytes.
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Objective To improve the classic Vannucci method for establishing a model of hypoxic-ischemic brain damage in the neonatal mice. Methods Postnatal day 11 KM mice were randomly assigned into normal control group ( N group, n=20) and hypoxic-ischemic brain damage group (HIBD group, n=160). For the HIBD group, the left common carotid artery of mice was ligated and exposed to hypoxia according to different conditions in the groups C1-C8, then com-pared the mortality and the success rates of all groups. TTC staining and relative infarct volume was measured to select the most stable conditions of modeling. In all groups, the growth and development of mice were evaluated by body weight growth curve at different time points after modeling. Longa test, grip test and hanging test were porformed to assess the neu-romotor function. HE staining was used to detect cerebral neuronal pathological changes. Results Neonatal mouse models of hypoxic-ischemic brain damage were established by the left common carotid artery ligation and hypoxia for 45 min under conditions of 8% O2 and 35℃, which resulted a low mortality rate (8. 3%) and high success rate (47. 92%). Compared with the normal group, mice of the HIBD group grew slowly in body weight and showed severe motor dysfunction. The liga-tion side of cerebral artery showed infarction area which accounted for 7. 76 ± 0. 70% of the total brain. The cortex and hip-pocampus of ligated brain tissue showed neuron degeneration and necrosis. Conclusions The neonatal mouse model of hy-poxic-ischemic brain damage is successfully established by our modified method , i. e. to ligate the left common carotid ar-tery and to expose the mice to hypoxia at 8% O2 and 35℃ for 45 min. This model provides a liable and stable experimental animal model for research of neonatal hypoxic-ischemic brain damage.
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Objective To improve the classic Vannucci method for establishing a model of hypoxic-ischemic brain damage in the neonatal mice. Methods Postnatal day 11 KM mice were randomly assigned into normal control group ( N group, n=20) and hypoxic-ischemic brain damage group (HIBD group, n=160). For the HIBD group, the left common carotid artery of mice was ligated and exposed to hypoxia according to different conditions in the groups C1-C8, then com-pared the mortality and the success rates of all groups. TTC staining and relative infarct volume was measured to select the most stable conditions of modeling. In all groups, the growth and development of mice were evaluated by body weight growth curve at different time points after modeling. Longa test, grip test and hanging test were porformed to assess the neu-romotor function. HE staining was used to detect cerebral neuronal pathological changes. Results Neonatal mouse models of hypoxic-ischemic brain damage were established by the left common carotid artery ligation and hypoxia for 45 min under conditions of 8% O2 and 35℃, which resulted a low mortality rate (8. 3%) and high success rate (47. 92%). Compared with the normal group, mice of the HIBD group grew slowly in body weight and showed severe motor dysfunction. The liga-tion side of cerebral artery showed infarction area which accounted for 7. 76 ± 0. 70% of the total brain. The cortex and hip-pocampus of ligated brain tissue showed neuron degeneration and necrosis. Conclusions The neonatal mouse model of hy-poxic-ischemic brain damage is successfully established by our modified method , i. e. to ligate the left common carotid ar-tery and to expose the mice to hypoxia at 8% O2 and 35℃ for 45 min. This model provides a liable and stable experimental animal model for research of neonatal hypoxic-ischemic brain damage.
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Objective To observe the effects of propofol on the hippocampal astrocytes and microglia in the nenotal mice . Methods 15 healthy mice from the same litters on postnatal 7 d were randomized into 3 groups:high dose propofol group ,low dose propofol group and 10% intralipid control group .All mice were treated with drugs on postnatal 7 d by intraperitoneal injection and were sacrificed at 24 h after drugs treatment .The high dose group was injected with propofol 60mg · kg -1 ;the low dose group was injected with propofol 30mg · kg -1 ;the control group was injected with the equal volume of 10% intralipid .The immunohistochem‐istry assay was used to detect the expression of glial fibrillary acidic protein (GFAP) and ionized calcium binding adapter molecular 1 (Iba1) for observing the effect of propofol on the astrocytes (AST ) and microglia in the hippocampus .Results Compared with the control group ,the number of GFAP‐labeled AST in the dentate gyms (DG) molecular layer of hippocampus in P7 mice of the high dose propofol group was significantly reduced (P<0 .01) ,while no obvious effect of the low‐dose propofol on the number of AST was observed ;high dose and low dose propofol all significantly decreased the number of Iba1‐labeled microglia .Conclusion Propofol can inhibit the growth of the hippocampal AST and microglia in a dose‐dependent manner .
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Objective To evaluate the effects of sevoflurane on learning and memory of neonatal mice .Methods 122 neonatalmice (7 days postnatal) were included in this study .72 of them were exposed to sevoflurane (1 .0 or 0 .5MAC ,minimum alveolar concentration) or 40% O2 for 2 h(hours) .Morris water maze was performed 4 and 12 weeks after anesthesia .Latency and swimming speed during training ,time on island and times across island during the research were recorded .The rest 50 mice was used in artery blood analysis during sevoflurane (1 .0 or 0 .5 MAC ,0 ,1 ,2 h) .Results pH ,PaO2 ,PaCO2 ,SaO2 were stable during anesthesia .Latency in control group were significantly shorter than the two anesthesia groups 4 weeks after anes-thesia and 3 days after the training .During the last 2 training days ,the latency in 1 .0 MAC sevoflurane-exposed mice were sig-nificantly longer than that of the 0 .5 MAC group .12 weeks after anesthesia ,the latency was still significantly longer in 1 .0 MAC sevoflurane-exposed mice on the last training day .The time on island and/or times across island were significantly decreased in anesthesia groupsduring theresearch performed 4 weeks and 12 weeks after anesthesia .Conclusion Early exposure to sevoflurane leads to a concentration and time-depended persistent learning and memory deficits to neonatal mice .
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Objective The aim of this study was to observe the growth difference and expression of cytochrome C of skin hair follicles in neonatal mice .Methods The morphology of different skin hair follicles of neonatal mice ( postnatal day 1-9)were observed by HE staining histology and cytochrome C was detected by immunohistochemistry .Results The skin hair follicles in different parts of neonatal mice showed differences not only in morphology but also in developmental pe -riods.Hair follicle growth in the back and tail skin had a nonlinear and growing period .After the nonlinear and growing pe-riod they began to grow rapidly .The tail development was slightly slower than that on the back .The hair follicles of vibris-sae were very special , and started to develop without a stable period .Conclusions The results of morphological observa-tion and cytochrome C immunohistochemistry demonstrate that differences exist in the hair follicle morphology and develop -mental times in the skin of different parts of the body in neonatal mice .
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Objective To investigate the potential effect of Lactobacillus acidophilus (L. acidophilus) on prevention and treatment of neonatal mice infected with human rotavirus (HRV). Methods Sixty 4-day-old kunming mice were randomly divided into control group. HRV infected group, L. acidophilus pretreated group (treated before HRV infection ) and L. acidophilus treated group(treated after HRV infection). The manifestation and pathological changes in small intestine of neonatal mice were observed. The HRV antigen in the feces and intestines were measured by ELISA and fluorescent-focus assay, respectively. Results The severity and duration of diarrhea as well as mortality in L. acidophilus pretreated group and treated group were lower than those in HRV infected group. The duration of HRV-antigens shedding following infection was considerably prolonged in HRV infected group compared to that in L. acidophilus pretreated group and treated group. Furthermore, decreased expression of HRV antigen and little pathological changes in intestinal mucosa were found in L. acidophilus pretreated group and treated group when compared with HRV infected group. Conclusion L. acidophilus may be used as an alternative approach for the prevention and treatment of neonatal mice infected with HRV.
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With light and electron microscope, we studied the morphology of the thymus of the neonatal mouse. The results showed: 1.the lobules of the thymus had not well developed and there was no distinct demarcation between the cortex and medulla; 2.a cyst composed of epithelial cells with microvilli or cilia might be frequently seen in the medulla; 3.occasionally small lymphocytes with some glycogen particles in their cytoplasm were observed; 4.only a few small-sized thymic corpusles existed in the medulla, The article also described the ultrastructure of the lymphocytes, epithelial reticular cells, macrophage, interdigitating cell and blood-thymus barrier in the thymus of the neonatal mouse.