AIM: To clarify the role of nitric oxide(NO) in ischemic preconditioning(IP) and its effects on apoptosis. METHODS: Seventy-two male Wistar rats were divided into the following six groups:ischemia/reperfusion (IR) group,IP group,IR+L-arg group,IP+L-arg group,IR+L-NAME group and IP+L-NAME group,The following changes were measured:cardiac hemodynamic parameters,infarct size,PMNs counting myocardial MPO activity and TUNEL staining.RESULTS: ①L-arg significantly attenuated ischemia/reperfusion-induced heart injury,reduced PMNs infiltration and cardiomyocyte apoptosis.②L-NAME also significantly reduced infarct size,PMNs infiltration and cardiomyocyte apoptosis compared with IR group,however,L-NAME aggravated ischemia/reperfusions-induced cardiac functional injury.③L-arg or L-NAME did not significantly alter the protective effect of ischemic preconditioning. CONCLUSION: Increased production of endogenous NO before prolonged ischemic period can protect hearts and inhibit apoptosis.L-NAME can inhibit iNOS activity and ONOO- production in reperfusion period to protect heart.

110 cases of infantile diarrhoea were admitted to this institute in a period from Aug. 30 to Dec. 22 of 1982.The patients were randomly divided into two groups, the TDP group and the control group. The general condition and the age distribution of the patients of both groups were similar. The patients of the TDP group received only TDP radiation instead of antibiotics and those of the control group received antibiotics therapy but no TDP. Other treatments such as fluid replacement, dietary regulation, etc, were the same in two groups. Stool samples were sent for routine examination and bacterial culture and blood samples for the determinations of the electrolyte levels, CO2CP, and immunity function for all the patients right after admission as well as just before discharge. The cure rate and course of the disease were similar in two groups. However the pathogenic organisms could still be revealed in the stool of the patients of the TDP group after recovery. But the rate of lymphocyte transformation was significantly higher in the patients of TDP group.It is concluded that TDP radiation is a simple, safe and effective treatment for infantile diarrhoea but its therapeutic mechanism remains obscure.

Objective To isolate and identify the cells from the cerebral cortex,cerebellar cortex,hippocampus,sub-ventricle region,brain stem and the spinal cord of neonatal rats and observe their growth morphology in vitro.Methods The cells were incubated from different regions of the CNS of neonatal rats by using DMEM/F12 media added with 10% bovine serum,and their growth morphology was observed by using inverted phase contrast microscope;then in the 10th day after incubation cells were fixed and immunocytochemical method was used to detect specific NSE antigen of the neurons and specific GFAP antigen of the astrocytes.Results Both neurons and astrocytes were studied in each region and they bloomed in the 10th day after incubation.Neurons had big triangular or ellipsoidal cell bodies surrounded with a halo and had robust nervous process which interlaced each other around cell bodies.The astrocytes had an ellipsoidal nucleus located at one side of the cell body and they had abundant processes branching profusely.Conclusion A method of culturing cells from different regions of the CNS of neonatal rats was described.A comparative morphology study of their growth was made and neurons and astrocytes of all the regions studied were identified.

Aim To clone and express the 1.2kb cDNA fragment (1/753-2 934bp) of human integrin α 4 subunit. Methods The 1.2 kb cDNA fragment of human integrin α 4 subunit was amplified from HL-60 total RNA by RT-PCR, then it was subcloned into expression vector pGEX-3X and induced with IPTG. Results The 1.2 kb cDNA fragment of human integrin α 4 subunit was cloned. The sequencing indicated that there was only one missense mutation (Arg→ Gln) among the fragment, and this mutation won't affect antigenicity after analysed by GOLDKEY. Then the 1.2 kb cDNA was subcloned into expression vector pGEX-3X. The α 4 fragment was highexpressed in E.coli after induced with IPTG. Conclusion The 1.2kb cDNA fragment of α 4 subunit was obtained, and it was highexpressed in E.coli, it might be important for study on the function of α 4 integrins.

The present study aims to isolate neural stem cells from neonatal rat hippocampus and induce them to differentiate into cholinergic neurons. A multipotent cell line derived from the hippocampi of neonatal rats which had the ability to form clones was incubated in serum-free DMEM/F12 medium added with 20ng/ml basic fibroblast growth factor (bFGF) and B27. After differentiation of the neural stem cells, immunocytochemistry was used to detect nestin, the antigen of the cell clone, and β-tubulin (Tuj 1 ), glial fibrillary acidic protein (GFAP) and galactocerebroside (Galc), the markers specific for neurons, astrocytes and oligodendrocytes, respectively. Embryonic chick skeletal muscle extract was used to induce the differentiation of the neural stem cells into cholinergic neurons. The results showed that the cell line isolated from the hippocampi of neonatal rats expressed nestin and had the potential to form clones and differentiate into neurons, astrocytes and oligodendrocytes. Embryonic chick skeletal muscle extract can induce 9.6% of the isolated cell line to differentiate into cholinergic neurons compared with 3.9% in controls. These findings suggested that the cell line, which expressed nestin antigen, was a multipotent cell line capable of self-renewing, and was believed to contain stem cells of the CNS. These neural stem cells can be induced to differentiate into cholinergic neurons by using embryonic chick skeletal muscle extract.