BACKGROUND: Hemorrhagic stroke (HS) is associated with significant disability and mortality. However, the relationship between meteorological factors and hemorrhagic stroke, as well as the potential moderating role of these factors, remains unclear. METHODS: Daily data on HS, air pollution, and meteorological conditions were collected from January 2015 to December 2021 in Ganzhou to analyze the relationship between meteorological factors and HS admissions. This analysis employed a time-stratified case-crossover design in conjunction with a distributional lag nonlinear model. Additionally, a bivariate response surface modelling was utilized to further investigate the interaction between meteorological factors and particulate matter. The study also stratified the analyses by gender and age. To investigate the potential impact of extreme weather conditions on HS, this study defined the 97.5th percentile as representing extremely high weather conditions, while the 2.5th percentile was classified as extremely low. RESULTS: In single-day lags, the risk of admissions for HS was significantly associated with extremely low temperature (lag 1-2 and lag 13-14), extremely low humidity (lag 1 and lag 9-12), and extremely high precipitation (lag 2-7). Females exhibited greater susceptibility to extremely low temperature than males within the single-day lag pattern in the subcomponent layer, with a maximum relative risk (RR) that was 7% higher. In the cumulative lag analysis, the risk of HS admissions was significantly associated with extremely high temperature (lag 0-8∼lag 0-14), extremely low humidity (lag 0-2∼lag 0-14), and extremely high precipitation (lag 0-4∼lag 0-14). Within the cumulative lag day structure of the subcomponent layer, both extremely low and extremely high temperature had a more pronounced effect on females and aged ≥65 years. The risk of HS admissions was positively associated with extremely high barometric pressure in the female subgroups (lag 0-1 and lag 0-2). The highest number of HS admissions occurred when high PM_2.5 concentrations coexisted with low precipitation. CONCLUSIONS Meteorological factors were significantly associated with the risk of hospital admissions for HS. Individuals who were female and aged ≥65 years were found to be more susceptible to these meteorological influences. Additionally, an interaction was observed between airborne particulate matter and meteorological factors. These findings contributed new evidence to the association between meteorological factors and HS.
China/epidemiology* ; Humans ; Female ; Male ; Aged ; Middle Aged ; Cross-Over Studies ; Hospitalization/statistics & numerical data* ; Adult ; Hemorrhagic Stroke/etiology* ; Meteorological Concepts ; Weather ; Particulate Matter/analysis* ; Air Pollution/adverse effects* ; Environmental Exposure/adverse effects* ; Aged, 80 and over ; Young Adult

Objective To investigate the effect of rhynchophylline on mRNA expression of excitatory amino acid transporter 2 (EAAT2 ) and N-methyl-D-aspartic acid receptor 2B (NR2B) after astrocyte oxygen-glucose deprivation. Methods The subcultured third generation astrocytes from the hippocampus were inoculated into 6-well plates, and they were divided into blank control group, hypoxia-ischemia group,low-dose rhynchophylline group (0. 02 mg/ml) and high-dose rhynchophylline group (0. 2 mg/ml) after the cells were attached to the wall and grew out protrusion. The total RNAs in each group were extracted.Real-time fluorescence quantitative polymerase chain reaction was used to detect the expression levels of EAAT2 and NR2B mRNA in astrocytes of each group. Results Compared with the blank control group, the expression levels of NR2B and EAAT2 mRNA in astrocytes of the ischemia-hypoxia group were significantly higher (all P < 0. 05 ). The expression levels of NR2B and EAAT2 mRNA in the low-dose rhynchophylline group were lower than those in ischemia-hypoxia group, but there was no significant difference. The expression levels of NR2B and EAAT2 mRNA in the high-dose rhynchophylline group were significantly lower than the ischemia-hypoxia group and the low-dose rhynchophylline group (all P < 0. 05).Conclusion The expression of EAAT2 and NR2B mRNA in astrocytes of hippocampus cultured in vitro was significantly increased after ischemia and hypoxia, and rhynchophylline intervention could significantly reduce its expression in a concentration dependent manner.

Objective To investigate the effects of Yangxueqingnao Granule on the proliferation and differentiation of endogenous neural stem cells and their neuroprotective mechanism after brain ischemia. Methods Cerebral ischemia was induced in rats by temporary middle cerebral artery occlusion. Ischemic animals received Yangxue Qingnao Granule at high and low doses at days 3,7, 14,and 21 after MCAO. Neurological score and TTC staining were used to assess the neurological deficits and the volume of cerebral infarction, respectively. Immunohistochemistry was used to detect Brdu and Nestin expression in the subventricular zone(SVZ)and hippocampal dentate gyrus subgranular zone(SGZ)region. Results The rats in MCAO control group, low dose group and high dose group showed varying degrees of neurological def-icits and the volume of cerebral infarctions. The neurological defect scores and volume of cerebral infarction were signifi-cantly different at different time points in each group ( P<0.01). 2. The mean fluorescence intensity values of Brdu posi-tive cells or the Nestin positive cells in SVZ and SGZ regions were significantly different ( P< 0.01) at different time points after treatment for 3,7,14 or 21 days. The mean fluorescence intensity values of Brdu positive cells or the Nestin positive cells in SVZ and SGZ regions were significant different among low dose group, high dose group and MCAO con-trol group. The mean fluorescence intensity values of Brdu positive cells or the Nestin positive cells in SVZ and SGZ re-gions were significantly different among low dose group, High dose group and control group. High dose group significantly increased the mean fluorescence intensity values of Brdu positive cells or the Nestin positive cells in SVZ and SGZ re-gions. Conculsions Yangxue Qingnao Granule is able to promote the functional recovery and reduce the volume of cere-bral infarction in ischemic rats. Yangxue Qingnao Granule can enhance the proliferation and differentiation of endoge-nous neural stem cells in ischemic rats.

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