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Biomedical subjects

Yi Tian

Publications and source records attributed to Yi Tian.

20 records · Page 2Linked to original sources

[Relation between helicobacter pylori L-form infection and tumor angiogenesis in human esophageal carcinoma].

OBJECTIVE: To investigate the correlation between helicobacter pylori L-form (Hp-L) infection in human esophageal carcinoma (EC) and tumor angiogenesis, and study the effect of Hp-L on the malignant biological behaviors of EC. METHODS: Hp-L was examined in 98 patients with EC and 30 controls by Gram stain, electronmicroscopic technique and immunohistochemical stain (ABC method). VEGF, p53 protein and microvessel density (MVD) were examined by immunohistochemical stain (SP method) with their relationship with the clinicopathologic factors analyzed. RESULTS: The positive rate of Hp-L was 60.2% in EC group. Two types of Hp-L were detected in the tissue of EC by electronmicroscopic technique, which lay in the outer or inner carcinoma cells. The positive rates of Hp-L, MVD, VEGF and p53 in the cancer group were significantly higher than those in control group (P < 0.005-0.001). The positive rates of MVD, VEGF and p53 in the Hp-L positive group of EC were significantly higher than those in Hp-L negative group (P < 0.005-0.001). The positive rate of Hp-L was correlated with MVD (r = 0.46, P < 0.01) and the expression of VEGF and p53 (r = 0.31, P < 0.01). The positive rate of Hp-L in the EC group was correlated with vessel invasion, depth of invasion, metastasis to the para-esophageal and distant lymph nodes except tumor size. CONCLUSION: Hp-L infection in EC is closely related with tumor angiogenesis and may be an important promoting factor in esophageal carcinoma growth, invasion and metastasis.

Adult↗

Comparison of three doses of enalapril in preventing left ventricular remodeling after acute myocardial infarction in the rat.

OBJECTIVE: To compare the effects of high, middle and low doses of enalapril in preventing left ventricular remodeling (LVRM) after acute myocardial infarction (AMI) in rats, especially evaluating the efficacy of low dose enalapril. METHODS: AMI was induced by ligating the left coronary artery in 149 female SD rats. 48 hours after the procedure, the 97 surviving rats were randomized to one of the following four groups: (1) AMI controls (n = 24), (2) high-dose (10 mg x kg(-1) x d(-1), n = 25), (3) middle-dose (1 mg x kg(-1) x d(-1), n = 23), and (4) low-dose (0.1 mg x kg(-1) x d(-1), n = 25) enalapril groups. In addition, sham-operated (n = 13) and normal rats (n = 10) were randomly selected to serve as non-infarction controls. Enalapril was delivered by direct gastric gavage. After 4 weeks of therapy, hemodynamic studies were performed, then the rat hearts were fixed with 10% formalin and pathology analysis was performed. Exclusive of the dead rats and those with MI size < 35% or > 55%, complete experimental data were obtained from 67 rats, which were comprised of (1) AMI controls (n = 13), (2) high-dose enalapril (n = 13), (3) middle-dose enalapril (n = 12), (4) low-dose enalapril (n = 12), (5) sham-operated (n = 8) and (6) normal (n = 9) groups. RESULTS: There were no significant differences among the four AMI groups in infarction size (all P > 0.05). Compared with the sham-operated group, the left ventricular (LV) end diastolic pressure (LVEDP), volume (LVV), absolute and relative weight (LVAW, LVRW) in AMI group were all significantly increased (all P < 0.001), while maximum LV pressure rising and dropping rates (+/- dp/dt) and their corrected values by LV systolic pressure (+/- dp/dt/LVSP) were all significantly reduced in the AMI control group (P < 0.01 - 0.001), indicating LVRM occurred and LV systolic and diastolic functions were impaired. Compared with the AMI group, LVEDP, LVV, LVAW and LVRW were all significantly decreased in the three enalapril groups (control P < 0.001), with the reduction of LVEDP, LVV and LVAW being more significant in high-dose than in low-dose enalapril groups (all P < 0.05), and the +/- dp/dt/LVSP were significantly increased only in the high and middle-dose enalapril groups (P < 0.01). CONCLUSIONS: High, middle and low doses of enalapril were all effective in preventing LVRM after AMI in the rat, with low dose enalapril being effective and high dose superior. As for LV functional improvement, only high and middle-dose enalapril were effective.

Angiotensin-Converting Enzyme Inhibitors↗