Objective To investigate the involvement of Bcl-2 and Bax mRNA expressions in mitochondrial toxin 3-nitropropionic acid(3-NPA)induced ischemic tolerance to focal cerebral ischemia in rats.Methods Rats were administrated 3-NPA intraperitoneally at dose of 20 mg/kg 3 days prior to a 2 h middle cerebral artery occlusion followed by 1 h,6 h,12 h,24 h and 48 h of reperfusion.The Bcl-2 and Bax mRNA expressions were measured by reverse transcriptase polymerase chain reaction and compared to the sham operation group and ischemic reperfusion group.Results Compared to the sham operation group,the ischemic reperfusion and 3-NPA pretreated groups exhibited an increase in Bcl-2 and Bax mRNA after reperfusion every time point of focal cerebral ischemia(all(P

BACKGROUND:Currently,there is not a standard method for in vitro culture and large scale amplification of umbilical cord blood mesenchymal stem cells(UCB-MSCs).OBJECTIVE:To investigate the isolation,purification and culture of UCB-MSCs in vitro,and to detect its surface marker variation.METHODS:The monocytes were harvested from UCB using 1.077 g/cm3 lymphocytes separating solution and density gradient centrifugation,followed by incubation in an incubator containing 5%CO2 at 37℃.The cell morphological changes were observed at different time points and the expression of surface marker was detected using flow cytometry.RESULTS AND CONCLUSION:The monocytes isolated from the UCB grew initially into numerous hematopoietic cell clones,most of which were granulocyte/macrophage colony-forming units and burst forming unit-erithroid,increasing by(37.1±2.3)and (10.4±1.7),respectively.Switzerland staining showed most of them were granulocyte clones(80,1±85.2)%,next was erythroid clones(14.2±1.8)%.At 7 days after culture,some shuttle fibroblast-like cells and fiat osteogenic-like cell spread the whole plastic well.At 14 days after culture,flow cytometry showed CD38+ cells accounted for 1.64%,and CD34+/CD38+ cells accounted for 1,71%,and CD34+/CD38- were 0.55%.PI+ and Annexin-V+ cells accounted for 0.05% and 0.18% respectively.At 21 days after culture,CD38+,CD34+/CD38+ and CD34+/CD38- cells were 74.32%,1.61%,and 0.24%.The results reveled that UCB-MSCs can be isolated and cultured in vitro.

In order to investigate the protective effect of hypoxic preconditioning on the cerebral ischemia-reperfusion injury, the expression of Bcl-2 and Bax was detected by using immunohistochemical staining after 3 h cerebral ischemia followed by 1, 6, 12, 24 and 48 h reperfusion respectively in rats treated with or without hypoxic preconditioning before cerebral ischemia. In addition,the apoptosis of neural cells and the behavioral scores for neurological functions recovery were evaluated by TUNEL staining and "crawvling method", respectively. Compared with control group (cerebral ischemia-reperfusion without hypoxic preconditioning), the expression of Bcl-2 was significantly increased, but that of Bax decreased in the hypoxic preconditioning group (cerebral ischemiareperfusion with hypoxic preconditioning), both P＜0. 05. The pre-treatment with hypoxic preconditioning could reduce the apoptosis of neural cells and promote the neurological function recovery as compared to control group. It was suggested that hypoxic preconditioning may have protective effects on the cerebral ischemia-reperfusion injury by inhibiting the apoptosis of neural cells, increase the expression of Bcl-2 and decrease the expression of Bax.

Objective Mitochondrial DNA depletion syndrome is a rare autosomal recessive disorder characterized by complex genetic and clinical manifestations.This study aimed to investigate the clinical and laboratory features of a boy with mitochondrial encephalomyopathy caused by SUCLG1 mutation.Methods The clinical data and genetic test of a patient with mitochondrial DNA depletion syndrome were retrospectively analyzed.Result The proband presented with limb weakness at the 4th month after birth,and presented dystrophic appearance,muscular hypotonia,psychomotor retardation,failure to thrive,hearing impairment,scoliosis,thoracocyllosis and facial features at 9 months old.Laboratory tests showed blood lactic acid and pymvate increased,liver damage and abnormal myocardial enzymes.Plasma camitine ester profiling showed that amino acids decreased and C4-dicarboxylic-carnitine increased.Urinary organic acid analysis showed increased concentration of methylmalonic acid and its metabolites indicating methyl malonic aciduria.MRI showed bilateral T2 hyperintensities in bilateral caudate nuelei and lenticular and brain atrophy-like changes.Brainstem auditory evoked potential showed severe hearing loss.His development quotient was 35.Genetic sequencing of MUT,,MMAA,MMAB and other classic mitochondrial disease related genes of the proband revealed no mutation.Two heterozygous mutations,c.961C＞G and c.713T＞C,inherited from the phenotype of normal parents were detected in his SUCLG1 gene.The copy number of mitochondrial DNA was 244/cell in peripheral blood leukocytes,equivalent to 68.4％ of that in normal control.Conclusion In this study,an infant with muscular hypotonia,psychomotor retardation,deafness and slightly increased urine methyl malonic acid was diagnosed by genetic test.For patients with unexplained hypotonia,mental retardation,abnormal movements,hearing disorder together with increased blood pyruvic acid and lactic acid,mild methylmalonic acidemia and abnormal acylcarnitine,mitochondrial DNA depletion syndrome should be considered.Gene analysis is important for diagnosis and prenatal diagnosis of the next pregnancy.