Objective To study the relationship between the DNA content of chondrocytes in the costal cartilage and postmortem interval in putrefactive rat cadavers.Methods Nuclear DNA wag visualized by modified Feulgen's staining method.DNA content of ehondrocytes in the costal cartilage was semi-quantita tively determined by a computerized image analysis system in rats within 35d postmortem.Results Staining intensity of the nuclei was gradually reduced within from 1d to 28d postmortem.The nuclej could not be detected at 35d.The DNA content of chondrocytes decreased time-dependently within 28 days after death as determined semi-quantitatively,which revealed a linear relationship between DNA content and postmortem interval.Conclusion DNA content of chondrocytes in the costal cartilage reduces time-dependently with the extension of postmortem interval.

AIM: To construct recombinant adenovirus vector containing brain derived neurotrophic factor, (BDNF) gene using bacterial homogenous recombination, and investigate the expression in expanded rat mesenchymal stem cells (rMSC) in vitro. METHODS: BDNF gene and proBDNF gene were subcloned into adenovirus shuttle plasmid pAdTrack-CMV containing enhanced green fluorescent protein gene (EGFP) expression cassette, forming shuttle vector of pAdTrack-BDNF, and pAdTrack-proBDNF, and co-transformed into BJ5183 bacterial cells with adenovirus backbone vector pAdEasy-1 using chemical transformation. After the recombinant adenovirus vector was obtained, the identified recombinant adenovirus plasmid DNA was digested with Pac I and transfected to 293 cells to package recombinant adenovirus particles. rMSC were infected by recombinant adenovirus and EGFP expression was detected using fluorescent microscope. Infection efficiency was assessed by flow cytometrics. Western blotting identified expression of Ad -proBDNF and Ad-BDNF in rMSC. rMSC infected with Ad -proBDNF and Ad-BDNF were induced to differentiate into neuron-like cells. rMSC infected with Ad -proBDNF and Ad-BDNF were injected into nude mice and assessd in vivo. RESULTS: We successfully constructed the recombinant adenovirus Ad -proBDNF and Ad-BDNF that expressed in expanded rMSC in vitro.CONCLUSION: Recombinant adenovirus high-effectively mediates Ad -proBDNF and Ad-BDNF expression in expanded rMSC in vitro and in vivo.

Objective To study the influence of rosemary essential oil inhalation on the memory of mice experiencing sleep deprivation and to delineate the possible mechanisms involved.Methods C57BL/6J mice were randomly divided into four experimental groups in this study:a control group(Con),a control group with rosemary essential oil inhalation(Con+REO),a sleep deprivation group(SD)and a sleep deprivation group with rosemary essential oil inhalation(SD+REO).A 72-hour sleep deprivation model was induced using the multiple platform water environment method,with the Con+REO and SD+REO groups exposed to rosemary essential oil inhalation.Cognitive function was evaluated through Y-maze and novel object recognition tests.The hippocampal tissue was analyzed for superoxide dismutase(SOD)activity and the concentrations of malondialdehyde(MDA)and glutathione(GSH).ELISA was used to determine the levels of norepinephrine(NE),dopamine(DA),and serotonin 5-hydroxytryptamine(5-HT)in the hippocampus.The expression levels of postsynaptic density 95(PSD95)and brain-derived neurotrophic factor(BDNF)in the hippocampus were determined using immunoblotting techniques.Results Compared with the Con and Con+REO groups,the SD group demonstrated a significant reduction in the spontaneous alternation percentage in the Y-maze as well as the novel object recognition index.Additionally,there was a pronounced decrease in hippocampal SOD activity and GSH content,a substantial elevation in MDA levels,and a decrease in the levels of DA,NE,and 5-HT.The expressions of PSD95 and BDNF proteins also decreased.In comparison with the SD group,the SD+REO group exhibited a significant increase in the spontaneous alternation percentage in the Y-maze and the novel object recognition index.There was also a marked increase in hippocampal SOD activity and GSH content,a reduction in MDA levels and elevated levels of NE and DA.Moreover,the expressions of PSD95 and BDNF proteins were upregulated.Conclusion The inhalation of rosemary essential oil enhances the memory of sleep-deprived mice,and the underlying mechanism may involve the mitigation of oxidative stress within the hippocampal tissue,the modulation of neurotransmitter levels,and the facilitation of synaptic plasticity.