Optimization of primary human eccrine sweet glands' isolation in vitro / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To optimize the methods of isolating human eccrine sweat gland cells in vitro so as to get efficiently primary human sweat glands.</p><p><b>METHODS</b>The fresh and normal skin tissue was cut into pieces of microskin about 1mm3 and the following 3 group digestion buffer was applied to isolated gland cells. The digestion buffer of group A was the equivoluminal mixture of Trypsin-Ethylene Diamine Tetraacetic Acid (EDTA) and collagenase-II (2 mg/ml). The digestion buffer of group B was collagenase-II (2 mg/ml) traditionally and group C was Trypsin-EDTA. These three groups were placed into an incubator simultaneously and the emerging time of dissociated sweat glands was calculated. Sweat glands were sorted out and then placed in culture dish. The adherence and the growth of cells were observed. The proliferation index was detected by flow cytometry. The identification of cultured cells was performed by immunocytochemical staining.</p><p><b>RESULTS</b>After digesting 30 min in group A and C, a very few of dissociated sweat glands were emerging. But after digesting for 2 h, there were lots of dissociated sweat glands emerging in group A rather than in group C. The emergence of dissociated sweat glands in group B would require at least 6 hours. After seeded in culture dishes, the sweat glands in group C couldn't adhere to the wall of dish, but the sweat glands in group A and B adhered very well and even grew like paving stones after 9 days. In addition, the proliferation index were (18 ± 4) % and (17 ± 6) % respectively, there was no statistical difference. The results of immunocytochemical staining showed that the cells expressed carcino-embryonic antigen (CEA) and cytokeratin 7(CK7) in group A and B.</p><p><b>CONCLUSION</b>Trypsin-EDTA combined with collagenase-II can shorten the time of isolating sweat gland cells and have no effect on cell activity and proliferation.</p>

Effect of 5-aza-2'-deoxycytidine on growth and methylation of RUNX3 gene in human pancreatic cancer cell line MiaPaca2 / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the effect of demethylating agent 5-aza-2'-deoxycytidine (5-Aza-CdR) on the growth of human pancreatic cancer cell line MiaPaca2 and the expression and methylation of tumor suppressor gene RUNX3.</p><p><b>METHODS</b>Human pancreatic cancer cell line MiaPaca2 cells were treated with different concentrations of 5-Aza-CdR. Morphological changes of MiaPaca2 cells were observed by light microscopy. The activity of cell proliferation was analyzed by MTT assay. The changes of RUNX3 mRNA expression were detected by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). Changes of RUNX3 gene methylation was detected by methylation-specific polymerase chain reaction.</p><p><b>RESULTS</b>MiaPaca2 cells were treated with 2.5, 5, 10 and 20 µmo1/L 5-Aza-CdR, respectively. The inhibition rates of MiaPaca2 cells treated for 24 h were (9.17 ± 2.15)%, (10.75 ± 2.04)%, (12.57 ± 1.64)% and (18.70 ± 1.51)%, respectively. The inhibition rates were (14.94 ± 1.68)%, (18.60 ± 1.57)%, (22.84 ± 1.58)% and (33.24 ± 1.53)%, respectively, after 48 h treatment; (21.46 ± 1.60)%, (28.62 ± 1.72)%, (35.14 ± 1.64)% and (45.06 ± 1.47)%, respectively, after 72 h treatment; and (26.35 ± 1.71)%, (34.48 ± 1.69)%, (40.05 ± 1.60)% and (49.99 ± 1.61)%, respectively, after 96 h treatment. The differences between inhibition rates of each experimental and control groups (0.00 ± 0.00)% were statistically significant (P < 0.05). At the same time, the inhibition rates of different concentration groups showed significant differences (P < 0.05). At 48 h, 72 h and 96 h, the inhibition rates of each pair concentration groups showed significant differences (P < 0.05). 5-Aza- CdR inhibited the growth of MiaPaca2 cells, and the higher the concentration, the stronger the inhibition after 24 h. 5-Aza-CdR also reversed the methylation status of RUNX3 gene, and restored the expression of RUNX3 mRNA with a dose-effect relationship.</p><p><b>CONCLUSIONS</b>The methylation of RUNX3 gene is significantly related with the occurrence and development of pancreatic cancer, and abnormal methylation of RUNX3 gene may contribute to the loss of RUNX3 mRNA expression. 5-Aza-CdR may effectively cause reversion of RUNX3 methylation, and treatment with 5-Aza-CdR can reactivate the gene expression and inhibit the cell growth. This may provide a new way for diagnosis and treatment of pancreatic cancer.</p>

Application of transanal ileus tube followed by laparoscopic surgery for malignant colorectal obstruction / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the safety and efficacy of transanal drainage tube followed by laparoscopic surgery in management of malignant colorectal obstruction.</p><p><b>METHODS</b>From March 2007 to October 2010, 37 patients with colorectal cancer manifesting acute complete mechanical obstruction were treated by ileus tube drainage. After irrigation and drainage ranging from 4 to 10 days, the radical operations and anastomosis were performed by laparoscopy.</p><p><b>RESULTS</b>The drainage tubes were successfully implanted in 34 patients. The decompression time of patients was (5.8 ± 1.6) d, ranging from 4 to 10 d. The abdominal pain and bloating symptoms were faded away after (3.8 ± 1.3) d (1 to 7 d) drainage. And comparing to that of patients when admission, abdominal circumference significantly reduced from (92 ± 7) cm to (84 ± 6) cm (P = 0.013) before surgery. Thirty-one cases were performed radical resection and anastomosis by laparoscopy after decompression. Postoperative recovery was smooth, and there was no serious complication.</p><p><b>CONCLUSIONS</b>Laparoscopic surgery followed decompression by transanal ileus tube is effective and safe for acute lower colorectal obstruction. Emergency surgery may be converted to limit surgery by this method. After appropriate bowel preparation, laparoscopic radical surgery and anastomosis is feasible.</p>

Selection of sentinel sites for death surveillance,using cluster or unequal probability sampling / 中华流行病学杂志

To compare the sampling errors from cluster or unequal probability sampling designs and to adopt the unequal probability sampling method to be used for death surveillance.Taking 107 areas from the county level in Shaanxi province as the sampling frame,a set of samples are drawn by equal probability cluster sampling and unequal probability designs methodologies.Sampling error and effect of each design are estimated according to their complex sample plans.Both the sampling errors depend on the sampling plan and the errors of equal probability in stratified cluster sampling appeares to be less than simple cluster sampling.The design effects of unequal probability stratified cluster sampling,such as πPS design,are slightly lower than those of equal probability stratified cluster sampling,but the unequal probability stratified cluster sampling can cover a wider scope of monitoring population.Conclusions:Results from the analysis of sampling data can not be conducted without consideration of the sampling plan when the sampling frame is finite and a given sampling plan and parameters,such as sampling proportion and population weights,are assigned in advance.Unequal probability cluster sampling designs seems to be more appropriate in selecting the national death surveillance sites since more available monitoring data can be obtained and having more weight in estimating the mortality for the whole province or the municipality to be selected.

Transfer of paralytic shellfish toxins via marine food chains: a simulated experiment / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To study the transfer of paralytic shellfish toxins (PST) using four simulated marine food chains: dinoflagellate Alexandrium tamarense --> Artemia Artemia salina --> Mysid shrimp Neomysis awatschensis; A. tamarense --> N. awatschensis; A. tamarense --> A. salina --> Perch Lateolabrax japonicus; and A. tamarense --> L. japonicus.</p><p><b>METHODS</b>The ingestion of A. tamarense, a producer of PST, by L. japonicus, N. awatschensis, and A. salina was first confirmed by microscopic observation of A. tamarense cells in the intestine samples of the three different organisms, and by the analysis of Chl.a levels in the samples. Toxin accumulation in L. japonicus and N. awatschensis directly from the feeding on A. tamarense or indirectly through the vector of A. salina was then studied. The toxicity of samples was measured using the AOAC mouse bioassay method, and the toxin content and profile of A. tamarense were analyzed by the HPLC method.</p><p><b>RESULTS</b>Both A. salina and N. awatschensis could ingest A. tamarense cells. However, the ingestion capability of A. salina exceeded that of N. awatschensis. After the exposure to the culture of A. tamarense (2000 cells x mL(-1)) for 70 minutes, the content of Chl.a in A. salina and N. awatschensis reached 0.87 and 0.024 microg x mg(-1), respectively. Besides, A. tamarense cells existed in the intestines of L. japonicus, N. awatschensis and A. salina by microscopic observation. Therefore, the three organisms could ingest A. tamarense cells directly. A. salina could accumulate high content of PST, and the toxicity of A. salina in samples collected on days 1, 4, and 5 of the experiment was 2.18, 2.6, and 2.1 MU x g(-1), respectively. All extracts from the samples could lead to death of tested mice within 7 minutes, and the toxin content in artemia sample collected on the 1st day was estimated to be 1.65 x 10(-5) microg STX equal/individual. Toxin accumulation in L. japonicus and N. awatschensis directly from the feeding on A. tamarense or indirectly from the vector of A. salina was also studied. The mice injected with extracts from L. japonicus and N. awatschensis samples that accumulated PST either directly or indirectly showed PST intoxication symptoms, indicating that low levels of PST existed in these samples.</p><p><b>CONCLUSION</b>Paralytic shellfish toxins can be transferred to L. japonicus, N. awatschensis, and A. salina from A. tamarense directly or indirectly via the food chains.</p>