An epidemiological investigation on a food-born outbreak of noroviru caused by Sydney 2012 G II.4 strain / 中华流行病学杂志

<p><b>OBJECTIVE</b>To identify the source of infection, route of transmission and risk factors related to a cluster of acute gastroenteritis cases in a university of Guangzhou.</p><p><b>METHODS</b>Cases were identified according to the definition. Descriptive epidemiological approaches and case-control study designs were employed in the analysis. All the samples were tested for norovirus by RT-PCR. Positive samples were subjected to both nucleotide sequence and homology analysis.</p><p><b>RESULTS</b>A total of 141 cases related to norovirus gastroenteritis were identified in January 8 to 21, 2013, with the attack rate as 8.5 per thousand (141/16,600). The peak in morbidity was seen on January 8 to 9. No clustering was found in different classes or dormitories. Results from the case-control study revealed that early cases were infected in Restaurant A (OR = 3.46, 95% CI: 1.07-11.16) and the cold shredded chicken set meal (OR = 17.82, 95% CI: 4.46-78.17) served at lunch (OR = 4.34, 95% CI: 1.18 -17.37) on January 7 was under suspicion. A total of 266 samples, including rectal swabs from the patients and kitchen wokers, leftover food and environmental swabs, were collected. Twenty-one samples (collected from 17 persons) were positive for norovirus by RT-PCR. About 29.6% (8/27) of the kitchen workers in the Restaurant A were tested positive for the virus. The pathogen was identified as the new norovirus genotype II.4 variant, termed Sydney 2012. The virus strains isolated from the patients among student and staff and the kitchen workers were 100% identical in their nucleotide sequence.</p><p><b>CONCLUSION</b>This was the first reported acute gastroenteritis outbreak caused by the new norovirus genotype II.4 variant, Sydney 2012, which showed that the food was contaminated by the asymptomatic kitchen workers who carried the virus.</p>

Expression and relationship between matrix metalloproteinase-7 and E-cadherin in gastric cancer / 肿瘤研究与临床

Objective To evaluate the expressions of MMP-7, E-cadherin in gastric carcinoma, and their relationship with tumor cell invasion and metastasis. Methods The MMP-7 mRNA and E-CD mRNA were detected by hybridization in situ in 78 gastric cancer tissues. Then analyze the relationship between the expression of MMP-7, E-CD and clinicopathological features. Results The expressions of MMP-7 and Ecadherin were significantly related with the invasion and metastasis of gastric cancer cell. The E-CD mRNA expression rate in MMP-7 mRNA positive gastric carcinoma tissue was much lower than that in negative carcinoma tissue (9.09 % vs 66.70 %). Conclusion Expression of MMP-7 mRNA and E-CD mRNA is associated with invasion, metastasis. Detection of MMP-7 mRNA and E-CD mRNA in bioptic specimens may be helpful in predicting tumor metastatic and recurrent potential and prognosis for patients with gastric carcinoma.

Effects of p27mt gene transfection mediated by replication deficient adenovirus on the proliferation and apoptosis of human hepatocellular carcinoma cells / 肿瘤研究与临床

Objective To assess the effects of p27mt gene transfection on the proliferation and apoptosis of human hepatocellular carcinoma cell (HCC) lines SMMC-7721. Methods A replication deficient adenovirus vector encoding p27mt (Ad-p27mt) was used and p27mt cDNA was transfected into human SMMC-7721 cell lines in vitro. The synthesis of DNA in SMMC-7721 cells was determined by using 3H-thymidine incorporation; the cell apoptosis was determined by flow cytometry, TUNEL method and DNA fragmentation analysis. Results The virus titer was 7.95?1012 cfu/ml, the transduction efficiency was 100 % when multiplicity of infection ≥50, FCM analysis revealed a sub-G1 cell peak in Ad-p27mt transduced hepatocellular carcinoma cell lines. Agarose electrophoresis showed marked ladder .The difference of apoptotic index between the Ad-p27mt group and the control group was statistically significant (58.6?4.3, vs 4.5?1.6, P