Surveillance of pathogens causing gastroenteritis and characterization of norovirus and sapovirus strains in Shenzhen, China, during 2011.

Viral gastroenteritis is one of the most common diseases in humans, and it is primarily caused by rotaviruses (RVs), astroviruses (AstVs), adenoviruses (AdVs), noroviruses (NoVs), and sapoviruses (SaVs). In this study, we determined the distribution of viral gastroenteritis and human calicivirus (HuCVs) in acute gastroenteritis patients in Shenzhen, China, during 2011. Real-time RT-PCR was used to detect norovirus (NoV), group A rotavirus (RV), adenovirus (AdV), and astrovirus (AstV). From a total of 983 fecal samples, NoV was detected in 210 (21.4 %); RoV in 173 (17.6 %); AstV in 10 (1.0 %); and AdV in 15 (1.5 %). Mixed infections involving two NoVs were found in 21 of the 387 pathogen-positive stool specimens. NoV and SaV genotypes were further tested using RT-PCRs and molecular typing and phylogenetic analysis were then performed based on the ORF1-ORF2 region for NoV and a conserved nucleotide sequence in the capsid gene for SaV. Of the 68 typed strains that were sequenced and genotyped, five were NoV G1 (7.5 %) and 63 were NoV GII (96.6 %). GII strains were clustered into five genotypes, including GII.4 (65.1 %; 36 GII.4 2006b and five GII.4 New Orleans), GII.3 (28.6 %), GII.2 (3.2 %), GII.6 (1.6 %), and GII.1 (1.6 %). While all fecal specimens were tested for SaVs, 15 (1.5 %) were positive, and of these, 12 isolates belonged to G1.2, and the remaining three SaV strains belonged to the SaV GII genogroup. Although various HuCVs were detected in acute gastroenteritis patients, NoV GII.4 2006b was more prevalent than the other HuCVs.

Molecular identification and analysis of human enteroviruses isolated from healthy children in Shenzhen, China from 2010 to 2011.

OBJECTIVE: To determine the prevalence and distribution of human enteroviruses (HEVs) among healthy children in Shenzhen, China. METHOD: Clinical specimens were obtained from 320 healthy children under 5 years old in Shenzhen, China from 2010 to 2011. The specimens were evaluated using real-time PCR and cell cultures. The positive specimens were further tested using reverse transcription-seminested PCR (RT-snPCR). Molecular typing and phylogenetic analysis were based on the sequence determined. RESULTS: Among the 320 samples, 34 were tested positive for HEVs (10.6%) and 22 different serotypes were identified using RT-snPCR. PV1 and PV2 were also detected. The predominant serotype observed was EV71 (17.6%), followed by CV-B4 (14.7%). HEV-B was detected most frequently, with an overall prevalence of 47.1%. HEV-A and HEV-C were found in 32.3% and 20.6% of the samples, respectively. No HEV-D was identified. Molecular phylogeny indicated that all EV71 strains were of C4 genotype. CONCLUSION: Although a variety of HEVs was detected in healthy children, HEV-B was relatively more prevalent than other HEV species. Considering HEV-A is more prevalent than HEV-B among patients with hand-foot-mouth disease, additional long-term surveillance of HEV is warranted in both asymptomatic and symptomatic populations.

[Analysis of characteristics of renin, aldosterone and aldosterone/renin ratio in patients with aldosterone-producing adenoma].

OBJECTIVE: To characterize the plasma renin activity (PRA) and plasma aldosterone concentration (PAC) and aldosterone/renin ratio (ARR) in patients with aldosterone-producing adenoma (APA). METHODS: We retrospectively analysed the data of PRA, PAC and ARR from 80 patients with APA, 70 patients with essential hypertension (EH) and 26 individuals with normal blood pressure (NBP). Patients with hypertension were further divided into taking anti-hypertensive drug group (D) and non drug treatment group (ND). All participants received at least one following tests:ARR screening test, supine-upright position test and saline load test.Receiver-operating characteristic (ROC) analysis was used for exploring the best cut-off value of ARR and low PRA. RESULTS: The median and percentages of PRA (ng×ml(-1)×h(-1), 1 ng×ml(-1)×h(-1) = 1 µg×L(-1)×h(-1)), PAC (ng/dl, 1 ng/dl = 27.7 pmol/L) and ARR (ng×dl(-1)/ng×ml(-1)×h(-1)) between NBP and EH (ND) groups showed no differences.Over 90% supine PRA ≥ 0.52 and 100% upright PRA ≥ 0.52 in the above two groups. On the contrary, 90% APA (ND) patients upright PRA <0.52. The lowest supine and upright ARR in APA (ND) patients was ≥ 24.2 and ≥ 37.5 respectively. ROC analysis suggested that the best screening cut-off values for APA were supine ARR ≥ 26.0, upright ARR ≥ 37.0; and low PRA cut-off value for APA were supine PRA <0.50 and upright PRA < 0.63 respectively. The sensitivity and specificity for APA diagnosis were about 88.2% and 61.5% when PAC ≥ 10.0 after saline load test. CONCLUSIONS: The distinguishing features of PRA, PAC and ARR can be used as a diagnostic indexs for the exclusive diagnosis of APA in various clinical tests. And low PRA cut-off values exist in APA patients.

[The genotype of norovirus in Shenzhen, 2010].

To describe epidemiologic characteristics of norovirus infection and its genotype in Shenzhen area of 2010. Stool specimens were collected from four monitoring point and detected by reverse transcription polymerase chain reaction (PT-PCR). Positive PCR products were purified and sequenced, and the sequences were performed by Clustal W and MEGA 4.0 programs, then genotype was identified and phylogenetic tree was constructed. Nucleotide sequence analysis revealed that 79 strains of NV belonged to norovirus genogroup II and 6 belonged to genogroup 1 of all 85 positive products. While 55 strains belonged to G II/4(2006b), 16 strains belonged to G II/4(2008 variant), 2 strains belonged to G II /1, 4 strains belonged to G II/5, 2 strains belonged to G II/11, 1 strain belonged to GII/4, 2 strains belonged to GII/5, 3 strains belonged to GI/6. The main genogroups of norovirus in Shenzhen ware GI and G II. G II /4 was one of the most major genotype of norovirus , while G II /4(2006b) variant was identified as the predominant strain in Shenzhen area.

Melatonin arrests peroxynitrite-induced tau hyperphosphorylation and the overactivation of protein kinases in rat brain.

The purpose of this study was to examine the in vivo effect of melatonin (MEL) on peroxynitrite-induced tau hyperphosphorylation and the involvement of glycogen synthase kinase-3beta (GSK-3beta) and mitogen-activated protein kinase (MAPK) families. Melatonin was injected into the right cerebroventricle of the rats 1 hr before the bilateral hippocampal injection of 3-morpholino-sydnonimine chloride (SIN-1), the recognized donor of peroxynitrite. Thereafter, the phosphorylation level of tau and the activity of the kinases were analyzed. The injection of SIN-1 induced hyperphosphorylation of tau at pS396 epitope with a concomitant activation of GSK-3beta and selective MAPK isoforms including p38alpha, p38beta, and p38delta but not p38gamma. The effect of peroxynitrite was confirmed using uric acid, a recognized scavenger of peroxynitrite. Preinjection of MEL significantly arrested the peroxynitrite-induced hyperphosphorylation of tau and the activation of GSK-3beta and MAPKs. Melatonin also ameliorated peroxynitrite-induced oxidative stress. We conclude that MEL can efficiently arrest peroxynitrite-induced tau hyperphosphorylation, and the underlying mechanism may involve scavenging the reactive species and suppressing the activated GSK-3beta and p38 MAPK family.

[Effects of sodium selenite on telomerase activity and telomere length].

To study the biological basis of selenium in resisting senescence through its effects on cellular telomerase activity and telomere length. In the experiments, the cell line of hepatocytes L-02 was divided into three groups supplemented with sodium selenite at final concentrations of 0, 0.5 and 2.5 micromol/L, respectively. Cellular telomerase activity was measured by telomeric repeat amplification protocol and enzymatic luminometric inorganic pyrophosphate detection assay. RT-PCR was used to semi-quantitatively detect human telomerase reverse transcriptase (hTERT) gene expression. The change of telomere length was assayed through flow cytometry and fluorescence in situ hybridization. Results showed that L-02 cells had low telomerase activity and hTERT gene expression level when cultured in the normal way. The cells grew well after 3-week-cultivation in the media supplemented with 0.5 or 2.5 micromol/L sodium selenite. Besides, sodium selenite significantly increased cellular telomerase activity and hTERT gene expression level. The telomere length of L-02 cells was also extended after 4-week-cultivation with sodium selenite. Thus, sodium selenite at nutritional doses could prolong the life span of hepatocytes L-02 through increasing telomerase activity and telomere length. This result provides a possible mechanism for explaining the anti-senescence function of selenium.