Optimising gene therapy of hypoparathyroidism with hematopoietic stem cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The treatment of hypoparathyroidism (HPT) is still a difficult clinical problem, which necessitates a new therapy. Gene therapy of HPT has been valuable, but how to improve the gene transfer efficiency and expression stability is a problem. This study was designed to optimize the gene therapy of HPT with hematopoietic stem cells (HSCs) recombined with the parathyroid hormone (PTH) gene.</p><p><b>METHODS</b>The human PTH gene was amplified by polymerase chain reaction (PCR) from pcDNA3.1-PTH vectors and inserted into murine stem cell virus (MSCV) vectors with double enzyme digestion (EcoRI and XhoI). The recombinant vectors were transfected into PA317 packaging cell lines by the lipofectin method and screened by G418 selective medium. The condensed recombinant retroviruses were extracted and used to infect HSCs, which were injected into mice suffering from HPT. The change of symptoms and serum levels of PTH and calcium in each group of mice were investigated.</p><p><b>RESULTS</b>The human PTH gene was inserted into MSCV vectors successfully and the titres were up to 2 x 10(7) colony forming unit (CFU)/ml in condensed retroviral solution. The secretion of PTH reached 15 ng.10(-6).cell(-1) per 48 hours. The wild type viruses were not detected via PCR amplification, so they were safe for use. The mice suffering from HPT recovered quickly and the serum levels of calcium and PTH remained normal for about three months after the HSCs recombined with PTH were injected into them. The therapeutic effect of this method was better than simple recombinant retroviruses injection.</p><p><b>CONCLUSIONS</b>The recombinant retroviral vectors MSCV-PTH and the high-titre condensed retroviral solution recombined with the PTH gene are obtained. The recombinant retroviral solution could infect HSCs at a high rate of efficiency. The infected HSCs could cure HPT in mice. This method has provided theoretical evidence for the clinical gene therapy of HPT.</p>

Experimental study on islet cells in rats under condition of three-dimensional microgravity / 中华外科杂志

<p><b>OBJECTIVE</b>To study the survival rate and secretory function of islet cells in rats under condition of three-dimensional microgravity.</p><p><b>METHODS</b>Isolated islet cells were assigned to flask-cultured or bioreactor-cultured. Survival rate of islets cultured for days 3, 7, 14 in stationary flasks or microgravity bioreactors was measured by AO-PI double-staining. Cultured islets were identified by dithizone (DTZ) staining, and insulin contents of different culture liquids were measured by radioimmunoassay.</p><p><b>RESULTS</b>Pancreatic islets stained nacarat with DTZ were easily visualized. When islet cells were cultured for 7 days and 14 days, survival rate of bioreactor-cultured islets was (0.9000 +/- 0.0107)% and 0.8038% +/- 0.0092% and higher than flask-cultured islets (P < 0.01). Insulin level of bioreactor-cultured islets is (70.875 +/- 0.31) m micro /L on the cultured 7 days while flask-cultured islets is (41.246 +/- 0.35) m micro /L. There was statistically significant difference of insulin production between the two groups (P < 0.01). Bioreactor-cultured islet contents were higher than flask-cultured on the cultured 14, 21 and 30 days (P < 0.01).</p><p><b>CONCLUSIONS</b>Islet cells survival rate and secretory function revealed that bioreactor-cultured islets functioned better compared with flask-cultured islets.</p>

Significance of serum level of NO and IL-8 in Helicobacter pylori associated gastric diseases / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the relation between serum level of interleukin-8 (IL-8), nitrogen monoxide (NO) and Helicobacter pylori (HP) infection, as well as the possible molecular mechanism of HP infection causing the imbalance of apoptosis and proliferation in gastric epithelial cells, which may lead to oncogenesis in stomach.</p><p><b>METHODS</b>Serum IL-8 level was detected with enzyme-linked immunosorbent assay (ELISA). Serum NO was detected with chrome reduction method using plated copper.</p><p><b>RESULTS</b>Serum level of IL-8 were 22.50 +/- 1.87 pg/ml in the normal tissue, 34.99 +/- 7.89 pg/ml in superficial gastritis, 65.27 +/- 10.60 pg/ml in atrophic gastritis and 94.84 +/- 11.09 pg/ml in gastric cancer (P < 0.01). Serum level of NO in the atrophic gastritis group (39.93 +/- 5.43 micromol/L) was significantly higher than that in the gastric cancer group (37.02 +/- 4.13 micromol/L) (P < 0.05). The differences in the other groups were not significant. IL-8 and NO levels in the HP(+) group were significantly higher than those in the HP(-) group (77.30 +/- 20.92 pg/ml vs 39.16 +/- 14.40 pg/ml, P < 0.01; 39.77 +/- 5.57 micromol/L vs 35.35 +/- 5.24 micromol/L, P < 0.01). Serum levels of IL-8 and NO in the cytotoxin-associated gene A protein (CagA)(+)HP group were significantly higher than those in the CagA(-)HP group (83.45 +/- 16.92 pg/ml vs 66.24 +/- 23.21 pg/ml, P < 0.01; 40.97 +/- 4.59 micromol/L vs 37.62 +/- 6.58 micromol/L, P < 0.05). Serum levels of IL-8 and NO showed positive correlation between superficial gastritis and atrophic gastritis groups (r = 0.881, r = 0.995), whereas no correlation was found in the normal or gastric cancer groups.</p><p><b>CONCLUSION</b>Serum levels of IL-8 and NO are correlated with CagA(+)HP strain infection. Combined detection of serum level of IL-8, NO and HP-CagA will contribute to the early diagnosis of precancerous lesion in the stomach.</p>