Relationship between thyroid-stimulating hormone and blood pressure in the middle-aged and elderly population

<p><b>INTRODUCTION</b>Hypothyroidism and subclinical hypothyroidism may be associated with hypertension and metabolic syndrome. The aim of this study was to investigate the relationship between thyroid-stimulating hormone (TSH) and blood pressure, as well as the relationship between thyroid function and insulin resistance in middle-aged and elderly Chinese.</p><p><b>METHODS</b>This was a cross-sectional, community-based study. Serum TSH, fasting glucose and insulin were measured in 2,988 subjects aged 35-80 years. Logistic regression analysis was used to identify the risk factors for hypertension. Analysis of variance and multiple linear regression analysis were performed to characterise the relationship among TSH, insulin resistance and blood pressure.</p><p><b>RESULTS</b>Higher serum TSH concentration was found to be an independent risk factor for hypertension in females (odds ratio 1.4, 95% confidence interval 1.02-1.93; p-value = 0.039). The female group with subclinical hypothyroidism and high normal TSH (2.5-4.8 mIU/L) were more susceptible to high blood pressure than those with low normal TSH (0.3-2.5 mIU/L) (p-value < 0.05). After adjustment for waist-hip ratio and body mass index, neither the correlation between blood pressure and homeostasis model assessment of insulin resistance (HOMA-IR) nor the correlation between TSH and HOMA-IR were found to be significant in this study.</p><p><b>CONCLUSION</b>This study provides evidence that both subclinical hypothyroidism and high normal TSH are independent risk factors for hypertension in middle-aged and elderly Chinese women.</p>

Construction and expression of human PDX-1 eukaryotic expression vector / 上海第二医科大学学报

Objective To construct eukaryotic expression vector of human pancreatic duodenal homeobox 1(PDX-1) gene,and to detect its expression in NIH3T3 cell lines. Methods The whole coding sequence of PDX-1 gene was amplified by polymerase chain reaction(PCR) from human pancreatic-cell tumors cDNA.The fragment was inserted into eukaryotic expression vector pcDNA3.1 plasmid.The recombinant plasmid was verified by double digestion and DNA sequencing.The expression of PDX-1 gene in NIH3T3 cells was assayed by Western blot. Results The length of specific fragment amplified by PCR was 852 bp,and the recombinant plasmid pcDNA3.1-PDX-1 showed two bands of 5.5 kb and 852 bp by digestion using respective restriction enzymes BamHⅠand EcoRⅠ.The sequence of PDX-1 gene was approved or confirmed by blasting to GenBank.It was suggested that PDX-1 gene had been cloned into pcDNA3.1 vector correctly.Western blot showed that PDX-1 gene was expressed,which was detected 24 h after pcDNA3.1-PDX-1 plasmid was transfected into NIH3T3 cells. Conclusion The recombinant eukaryotic expression vector pcDNA3.1-PDX-1 was successfully constructed and expressed in NIH3T3 cell lines.

Expression of human BTC with biological activity / 上海第二医科大学学报

Objective To obtain abundant human betacellulin(BTC) with biological activity. Methods The whole mature protein coding sequence of BTC gene was amplified by polymerase chain reaction(PCR) method applied to human pancreatic ?-cell tumors cDNA.The fragment was cloned into prokaryotic expression vector pET32a(+) plasmid.The recombinant plasmid was transformed into E.coli BL21 and the fusion protein was expressed under isopropyl-beta-D-thiogalactopyranoside(IPTG).The fusion protein was purified by Ni2+ affinity chromatography.SDS-PAGE and Western blot were employed to determine the expression and purification of the expected protein.BTC was added to culture NIH3T3 cells for 5 days,and cell proliferation was detected by MTT. Results Lots of fusion protein were produced,and the purified protein can stimulate the proliferation of NIH3T3 cells. Conclusion The human BTC can be successfully obtained from the pET32a(+) system with the biological activity of stimulating the proliferation of NIH3T3 cells.