ABSTRACT
Objective To investigate G protein-coupled estrogen receptor(GPER)mediated neuroprotective effect and mechanism in an ischemic stroke model. Methods Bilateral ovariectomy (OVX)was used to establish a castrated model of adult SPF grade female SD rats. Enzyme-linked immunosorbent assay was used to detect serum estrogen level at 4 weeks after procedure.Middle cerebral artery occlusion(MCAO)was use to prepare a stroke model.The rats were randomly divided into sham operation(n=6),MCAO(n=7),MCAO+estrogen(MCAO+E2,n=8),MCAO+agonist(MCAO+G1,n=8)and MCAO +antagonist G15(MCAO +G15,n =7)groups. The neurological severity score (NSS),2,3,5-triphenyltetrazolium chloride(TTC)staining were used to measure the volume of cerebral infarction in order to assess the effects of different interventions.Western blot was used to detect the protein expression of hypoxia inducible factor-1α(HIF-1α),c-Jun N-terminal kinase(JNK),and Caspase-3 in the ischemic penumbra. Results (1)Estrogen level:after OVX,The level of serum estrogen in rats was significantly lower than that before castration(20 ± 9 ng/L vs. 73 ± 21 ng/L,P <0. 01).(2)NSS score:the NSS score of MCAO in each group was significant higher than that in the sham operation group (P<0.01);The NSS score of the MCAO+G1 group was significantly lower than that of the MCAO group and the MCAO+G15 group(6.0 ±1.8 vs.11.9 ±2.0 and 10.0 ±2.1).The difference was statistically significant (all P<0.05).(3)Cerebral infarct volume:there was significant difference in infarcted volume between the sham operation group and all other groups(all P<0.01);Compared with the MCAO group and the MCAO+G15 group,the infarct volume of the MCAO+E2 group and MCAO+G1 group was significantly reduced(19.8 ± 4.0%,14.0 ± 2.9%)vs.29.7 ± 5.8% and 27.6 ± 3.6%).The difference was statistically significant (all P<0.05).(4)Results of Western blot:the relative optical density values of HIF-1α,JNK,and Caspase-3 of the MCAO group were higher than those of the MCAO + G1 group(all P <0.01). Conclusions GPER mediates the neuroprotective effect of estrogen in the ischemic stroke model.This protective effect is associated with the regulation of the expression levels of HIF-1α,JNK,and Caspase-3.
ABSTRACT
This study evaluated the correlation between DNA degradation of the splenic lymphocytes and the early time of death, examined the early time of death by computerized image analysis technique (CIAT) and identified the best parameter that quantitatively reflects the DNA degradation.The spleen tissues from 34 SD rats were collected, subjected to cell smearing every 2 h within the first 36 h after death, stained by Feulgen-Van's staining, three indices reflecting DNA content in splenic lymphocytes, including integral optical density (IOD), average optical density (AOD), average gray scale (AG) were measured by the image analysis. Our results showed that IOD and AOD decreased and AG increased over time within the first 36 h. A stepwise linear regression analysis showed that only AG was fitted. A correlation between the postmortem interval (PMI) and AG was identified and the corresponding regression equation was obtained. Our study suggests that CIAT is a useful and promising tool for the estimation of early PMI with good objectivity and reproducibility,and AG is a more effective and better quantitative indicator for the estimation of PMI within the first 36 h after death in rats.
ABSTRACT
To determining the postmortem interval (PMI) through quantitative analysis of the DNA degradation of cell nucleus in human brain and spleen by using image analysis technique (IAT). The brain and spleen tissues from 32 cadavers with known PMI were collected, subjected to cell smear every 1 h within the first 5-36 h after death, stained by Feulgen-Van's staining, Three indices reflecting DNA in brain cells (astrocytes) and splenic lymphocytes, including integral optical density (IOD), average optical density (AOD), average gray (AG) were measured by employing the mage analysis instrument. The results showed that IOD and AOD declined and AG increased with the prolongation of dead time within 5-36 h. A correlation between the PMI and gray parameters (IOD,AOD and AG) was identified and the corresponding regression equation was obtained. The parameters (IOD,AOD and AG) were proved to be effective quantitative indicators for accurate estimation of PMI within 5-36 h after death.
ABSTRACT
To determining the postmortem interval (PMI) through quantitative analysis of the DNA degradation of cell nucleus in human brain and spleen by using image analysis technique (IAT). The brain and spleen tissues from 32 cadavers with known PMI were collected, subjected to cell smear every 1 h within the first 5-36 h after death, stained by Feulgen-Van's staining, Three indices reflecting DNA in brain cells (astrocytes) and splenic lymphocytes, including integral optical density (IOD), average optical density (AOD), average gray (AG) were measured by employing the mage analysis instrument. The results showed that IOD and AOD declined and AG increased with the prolongation of dead time within 5-36 h. A correlation between the PMI and gray parameters (IOD, AOD and AG) was identified and the corresponding regression equation was obtained. The parameters (IOD, AOD and AG) were proved to be effective quantitative indicators for accurate estimation of PMI within 5-36 h after death.
Subject(s)
Cell Nucleus/pathology , DNA Degradation, Necrotic , Forensic Pathology , Liver/pathology , Postmortem Changes , Spleen/pathology , Time FactorsABSTRACT
Objective To study changes of DNA content in human spleen nuclei and seek an experimental method for estimation of the postmortem interval(PMI)using computerized image-analysis technique(CIAT).Methods Smear sections from spleen sampled were collected in 36 cadavers with known the accurate PMI respectively every hour within the first 36 hours after death,which were then fixed with cold Carony fixation.The smeared sections were stained by Feulgen-van's staining method.3 indices for spleen nucleic DNA including integral optical density(IOD),average optical density(AOD)and average gray(AG)were measured using the CIAT.Results IOD and AOD in the spleen nuclei declined regularly,whereas AG increased with the extension of PMIs in 36 hours.Conclusion There are definite relationships between the PMI and gray parameters(IOD、AOD and AG)representing the DAN content of nucleic DNA in the spleen in 36 hours after death,which may be used for estimation of PMI.