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Biomedical subjects

Xin Zhou

Publications and source records attributed to Xin Zhou.

135 records · Page 8Linked to original sources
PubMed2002

NF-kappaB inhibition enhances peroxynitrite-induced enterocyte apoptosis.

BACKGROUND: Sustained overproduction of nitric oxide and peroxynitrite (ONOO(-)) in conditions such as necrotizing enterocolitis and inflammatory bowel disease may promote gut barrier failure by inducing enterocyte apoptosis. NF-kappaB is upregulated in the gut during inflammation and, in addition to its proinflammatory effects, may upregulate protective or antiapoptotic factors such as inhibitor of apoptosis proteins (IAPs). We have previously demonstrated that NF-kappaB inhibition increases cytokine-induced enterocyte apoptosis; however, the effect of NF-kappaB on ONOO(-)-induced enterocyte apoptosis is unknown. MATERIALS AND METHODS: Rat intestinal epithelial cells (IEC-6) were transfected with the adenoviral vector AdIkappaB or AdlacZ. AdIkappaB contains a mutated form of IkappaB which functions as a superrepressor of NF-kappaB. Cells were then treated with 50 microM ONOO(-) or decomposed ONOO(-). Apoptosis was then determined by flow cytometry with annexin V-FITC and propidium iodide staining. Caspase activation and IAP, Bcl-2, Bad, and Bax expression were examined using Western blot analysis, and NF-kappaB activation was determined via electrophoretic mobility shift assay (EMSA). RESULTS: Inhibition of NF-kappaB with AdIkappaB significantly enhanced ONOO(-)-induced apoptosis in IEC-6 cells. ONOO(-) treatment did not activate NF-kappaB in IEC-6 cells as determined by EMSA. There was no difference in IAP, Bcl-2, Bad, and Bax expression between nontransfected, AdlacZ-transfected, and AdIkappaB-transfected cells. Baseline procaspase 3 activation was increased in AdIkappaB-transfected cells. CONCLUSIONS: NF-kappaB inhibition enhances ONOO(-)-induced enterocyte apoptosis, suggesting that NF-kappaB upregulates a protective factor. This protective factor does not appear to be an IAP or Bcl-2 family member and may be expressed constitutively, since ONOO(-) did not activate NF-kappaB over baseline levels of activation.

Adenoviridae↗
PubMed2002

Telomerase activity and its correlation with the proliferative potential of bone marrow in aplastic anemia in children.

OBJECTIVE: To explore telomerase activity and its association with the proliferative potential of hematopoietic stem cells in bone marrow (BM) in patients with aplastic anemia (AA). METHODS: Telomerase activity of mononuclear cells separated from BM was determined with the TRAPeze kit. BM specimens from 22 cases with AA and 7 normal controls were included. SPSS10.0 was applied to analyze data derived from telomerase activity and colony-forming unit-granulocyte and monocyte. RESULTS: The median telomerase activity level of BM in AA was 2-fold higher than that in normal controls. There was an inverse correlation in AA between telomerase activity and colony-forming unit (r = 0.78, p < 0.05). BM of chronic AA expressed higher telomerase than that of acute AA. CONCLUSIONS: Telomerase activity in AA was increased and may be the result of the negative feedback of hematopoietic potential. Telomerase activity varied between the subtypes of AA. Telomerase activity was conversely correlated with the proliferative potential of BM in AA.

Adolescent↗
PubMed2002

Alu-repeat polymorphism in the gene coding for tissue-type plasminogen activator and the risk of hypertension in a Chinese Han population.

Accumulating data support an association between hypertension and impaired fibrinolytic potential abnormalities in endogenous fibrinolysis. The present study examined whether there was an association between essential hypertension and either a polymorphism in the gene coding for t-PA or the plasma concentration of t-PA antigen. Chinese hypertensive subjects (n = 126) and normotensive controls (n = 102; sex- and age-matched with hypertensives) were recruited from among the outpatients of FuWai Hospital. The distributions of the II, ID, and DD genotypes of the t-PA gene in hypertensive patients (0.15, 0.49, 0.36) were similar to those in control subjects (0.11, 0.51, 0.38; p = 0.626). No significant difference in overall allele frequencies was found between the hypertension and control groups (p = 0.656). The allelic frequencies were in Hardy-Weinberg equilibrium. There was no evidence of an association between the level of t-PA antigen and risk of hypertension. Thus, in this case control study, neither the presence of the insertion allele of the Alu-repeat polymorphism of the t-PA nor the level of t-PA antigen were associated with the risk of essential hypertension.

Aged↗
PubMed2002

[A preliminary study of pentanucleotide repeat polymorphism of apolipoprotein(a) gene in coronary atherosclerotic heart disease].

OBJECTIVE: This study inquired into the relationship between a pentanucleotide repeats(PNR) polymorphism of the apolipoprotein(a)[apo(a)] gene and coronary atherosclerotic heart disease(CHD) in Chinese Han nationality. METHODS: PNR polymorphism of the apo(a) gene from 165 cases of CHD and 153 normal individuals were analyzed by polymerase chain reaction(PCR)-denature polyacrylamide gel electrophoresis-silver stain. RESULTS: The frequencies of (TTTTA)(5/8) genotype (0.188) and (TTTTA)(5) allele (0.115) in CHD group were remarkably higher than those in control group (0.039, 0.026)(P<0.01, P<0.05). CONCLUSION: These findings indicate that the PNR polymorphism of apo(a) is associated with the susceptibility to CHD, which may be involved in the development of CHD.

Aged↗
PubMed2002

[The relationship between GSTM1, GSTT1 gene polymorphisms and susceptibility to sporadic colorectal adenocarcinoma].

OBJECTIVE: To analyse the association genetic polymorphisms of glutathione S-transferase (GST) M1 and T1 with genetic susceptibility to sporadic colorectal adenocarcinoma (SCRAC). METHODS: All subjects are unrelated the Han people in Hubei province of China. Using multiple PCR, we studied the genetic polymorphisms of the GSTM1, GSTT1 genes of 101 healthy controls and 104 SCRAC patients. RESULTS: (1) All the differences of the frequency of GSTM1 null genotype between SCRACs and the controls, between proximal and distal SCRACs and between the elder and the younger SCRACs did not reach statistical significance. (2) The differences of the frequency of GSTT1 null genotype between SCRACs and the controls did not reach statistical significance too; But the null genotype for GSTT1 was significantly more common among distal SCRACs when compared with the proximals (66.2%:44.4%, chi(2) = 3.97, P < 0.05) and more common among the elder SCRACs when compared with younger SCRACs (70.9%:49.0%, chi(2) = 5.21, P < 0.05). (3) Subjects carring both of the null genotypes for GSTM1 and GSTT1 had more than 4.33-fold risk for developing SCRACs compared with the subjects caring both of the nonull genotypes for GSTM1 and GSTT1 (OR = 4.33, 95% confidence interval, 1.56 - 12.04). CONCLUSIONS: (1) There was no association the susceptibility to SCRAC with GSTM1 or GSTT1 null genotype alone, but the date suggests GSTT1 null genotype may influence the distal SCRAC, especially the elder; (2) The individual with both of the null genotypes of GSTM1 and GSTT1 increases markedly the risk of SCRAC, and this genotype is the susceptibility gene to SCRAC.

Adenocarcinoma↗
PubMed2002

[The relationship between apoptosis of the cardiac myocytes and myocardial dysfunction in severely scalded rats].

OBJECTIVE: To investigate relationship between apoptosis of the cardiac myocytes and myocardial dysfunction in severely scalded rats. METHODS: Wistar rats inflicted by 40% TBSA III degree scalding were employed as the model. The myocardial tissue was obtained from the left ventricle at different postburn time points. Apoptosis was determined by the determination of myocardial tissue Caspase-3 activity and TUNEL staining (terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling). The LVSP (left ventricular systolic pressure), LVEDP (left ventricular end-diastolic pressure) and +dp/dtmax (the rate of the rise of left ventricular pressure) and -dp/dtmax (the rate of the fall of left ventricular pressure) were all monitored by four-channel physiological recorder. In addition, myocardial activities of MPO and SOD were detected. RESULTS: The TUNEL staining of rat myocardial cells was positive at 6 postburn hour (PBH) and reached top level at 12 PBH. The change in Caspase-3 activity was earlier than that of apoptotic morphology and reached peak values at 3 and 6 PBHs. The left ventricular function (systolic and diastolic function) was significantly impaired after the scalding and dropped to the lowest levels at 12 PBHs. The increase in myocardial tissue MPO activity was accompanied by the decrease in SOD activity. CONCLUSION: Myocardial cellular apoptosis was one of the reasons of postburn myocardial injury in scalded rats. Caspase protease cascade pathway might be involved in the process of apoptosis, which suggested that the initiation of apoptosis was closely related to the infiltration of neutrophils and to the release of large amounts of oxygen free radicals in myocardial tissue.

Animals↗
PubMed2002

[Study on the chemical constituents of the volatile oil from Lysimachia trientaloides Hemsl].

The volatile oil from Lysimachia trientaloides Hemsl. was obtained by steam distillation. The chemical constituents were separated and identified by gas chromatography-mass spectrometry (GC-MS). The relative contents in the volatile oil were determined by peak area normalization. The yield of oil by steam distillation was 0.11%, and 40 chemical constituents were separated and identified. Terpenic series and their oxo-derivatives are major chemical constituents in the oil. The main compounds were patchouli alcohol(22.54%), L-bornyl acetate(16.17%), gamma-gurjunene(3.27%), delta-guaiene(2.62%), nerolidol(2.02%), linalool(1.99%) and palmitic acid(1.96%).

Camphanes↗