EV71 vaccination impact on the incidence of encephalitis in patients with hand, foot and mouth disease.

In order to analyze the effect of EV71 vaccination on the incidence of encephalitis in patients with HFMD, 292 cases were vaccinated, and 2,486 cases were not vaccinated which were collected in 2018 and 2019. It shows that the incidence rate of encephalitis in vaccinated patients was significantly lower than that in non-vaccinated (P = .028), which suggests that EV71 vaccine has a protective effect on the occurrence of encephalitis. But some EV71 vaccinated patients still developed into encephalitis showed that they had not produced protection or protection was weak against EV71-related encephalitis; the reasons require further investigation.

Geographical distribution and seasonal variation in paralytic shellfish toxins in the coastal water of the South China Sea.

Paralytic shellfish toxins (PSTs) are a group of the most harmful neurotoxins distributed worldwide. Marine organism samples, including mollusks, crustaceans and fish, collected from 11 sites around the coastal water of the South China Sea, were analyzed in terms of the PST and toxicity via high-performance liquid chromatography. The PST geographical distribution, detectable rate for PST and toxin content all increased slightly from 2006 to 2008 to 2015. High PST content with more than 2 nmol g-1 appeared in Shantou (ST), Shanwei (SW), Zhanjiang (ZJ), Beihai (BH), Xuwen (XW), Haikou (HK), Dongfang (DF), Wanning (WN) and Sanya (SY). Low PST content with less than 2 nmol g-1 appeared in Shenzhen (SZ) and Yangjiang (YJ). High PST toxicity over the safety limit 800 µg STXeq/kg appeared in ST, SW, ZJ, BH, DF, SY and XW. PST has significant seasonal characteristics and was mostly detected in spring, early summer (March-June) and autumn (September-November) in the coastal water of the South China Sea. PST was usually detected in some specific species of scallop, mussel, bloody clam, hard clam, razor clam, oyster, crab, shrimp and fish. Toxin profile variation of marine organism samples was influenced greatly by species, sampling time and site.

Seasonal variability of Protoceratium reticulatum and yessotoxins in Japanese scallop Patinopecten yessoensis in northern Yellow Sea of China.

This paper reports a toxic strain of Protoceratium reticulatum, its morphology, phylogeny, yessotoxins (YTXs) production and abundance in northern Yellow Sea of China from 2011 to 2015 was investigated. YTXs in hepatopancreas and edible parts of bottom sowing cultured Japanese scallop Patinopecten yessoensis in this sea area were determined weekly for 5 years. Other potential producers of YTXs, Gonyaulax spinifera and Lingulodinium polyedrum, were also investigated. Results revealed that Protoceratium reticulatum strain from the northern Yellow Sea belongs to a geographically widely distributed species. Motile cells of Protoceratium reticulatum contribute to YTXs in Japanese scallop, and G. spinifera may also be a potential contributor. Resting cysts of Protoceratium reticulatum, G. spinifera, and L. polyedrum in sediments were possibly important origins of YTXs in scallop cultured at sea bottom. YTXs in scallop decreased from 2011 to 2015, most toxins were concentrated in hepatopancreas, while a small portion in edible parts which was safe for consumption the whole year around.

Impact of IL-8-251A/T gene polymorphism on severity of disease caused by enterovirus 71 infection.

The study was performed in EV71-infected patients, with 97 mild cases and 80 severe cases. IL-8251A/T genotypes were determined by the polymerase chain reaction restriction fragment length polymorphism technique. Severe cases had a significantly higher frequency of the IL8-251 AT and TT genotypes than mild cases (52.5 % vs. 49.5 % and 42.5 % vs. 30.9 %, respectively; p = 0.024). The frequency of IL-8-251T alleles among the severe cases was also significantly higher than that of mild cases (68.7 % vs. 55.7 %, OR = 1.8, 95 % CI = 1.1-2.7, p = 0.012). There were significant differences in gender, age, fever days, WBC, CRP and BG concentration, and IL-8 levels among genotypes of IL-8251A/T in EV71-infected patients, but there were no significant differences in ALT, AST, CK-MB and EV71 loads. These findings suggested that the IL-8-251T allele is associated with susceptibility to severe disease in Chinese patients infected with EV71.

Association of Enterovirus 71 encephalitis with the interleukin-8 gene region in Chinese children.

The study was performed in 36 Chinese patients with Enterovirus 71 (EV71) encephalitis and 141 patients with EV71-related hand, foot and mouth disease (HFMD) without encephalitis. Genotyping was determined by polymerase chain reaction- restriction fragment length polymorphism. Patients with EV71 encephalitis had a significantly higher frequency of interleukin-8 (IL-8)-251TT genotype than patients with EV71-related HFMD without encephalitis (55.6% vs 31.2%, p = 0.023). The frequency of IL-8-251T alleles was significantly higher among patients with EV71 encephalitis than in patients with EV71-related HFMD without encephalitis (72.2% vs 58.9%, odds ratio 1.8, 95% confidence interval 1.0-3.2, p = 0.038). There were significant differences in gender, age, fever days, white blood cell count, C-reactive protein and blood glucose concentration and IL-8 levels among genotypes of IL-8-251A/T in EV71-infected patients, but no significant differences in alanine or aspartate aminotransferase, creatine kinase-myocardial isozyme and cerebrospinal fluid in patients with EV71 encephalitis. These findings suggest that the IL-8-251T allele is associated with susceptibility to EV71 encephalitis in Chinese patients.

First report on the detection of pectenotoxin groups in Chinese shellfish by LC-MS/MS.

Chinese shellfish samples were harvested from different locations along the Chinese coast. These shellfish were analyzed by liquid chromatography in combination with mass spectrometry to detect the following toxins: okadaic acid (OA), dinophysistoxins (DTXs), petenotoxins (PTXs), azaspiracids (AZAs), yessotoxins (YTXs), spirlides (SPXs) and gymnodimines (GYM). The results revealed the lipophilic toxin profiles varied with shellfish sampling locations. In addition to OA, GYM and YTX derivatives, PTX-2 and its derivatives were found for the first time in the following Chinese shellfish: Crassostrea gigas, Mactra chinensis and Mytilus galloprovincialis. The presence of GYM, YTXs, OA and PTXs in Chinese shellfish collected from regions where no previous record of DSP-neutral toxic compounds was reported. Serious efforts should therefore be made to conduct a phycotoxin monitoring program to detect the presence of lipophilic toxins in biological materials of marine origin, which may ensure that Chinese seafood products do not present a health risk. With respect to suspected carcinogenicity, further research on the distribution and concentrations of toxic compounds are needed, in order to carry out long-term risk assessments, particularly sub-acute and chronic toxicity tests associated with of lower doses.

[A indirect competitive ELISA to detect domoic acid in seawater and shellfish].

OBJECTIVE: A competitive enzyme-linked immunosorbent assay (ELISA) was developed for measurent domoic acid (DA) in seawater and shellfish. METHODS: DA was coupled to bovine serum albumin (BSA) and ovalbumin (OVA) by carbodiimide reaction. DA-BSA as immunogen was injected in BALB/c mice. Titres of the antisera against DA were determinated using DA-OVA as coating ligand by ELISA method. After female BALB/c mice were immunized six times, the polyclonal antibodies anti-DA was obtained. The competitive indirect ELISA for domoic acid in shellfish and seawater was established. RESULTS: Under optimal condition, the detection limit of DA was 10.0 ng/ml (equal 4 microg/g shellfish meat). The recovery of domoic acid added in seawater was 83.2% - 124.7% with a coefficient of variation of 4.7% - 5.9%, the recovery of domoic acid added in shellfish was 85.9% - 99.9% with a coefficient of variation of 2.4% - 7.1%.

[Preparation and application of the monoclonal antibody against okadaic acid].

An competitive indirect enzyme-linked immunosorbent assay was developed for measurement of okadaic acid (OA), a marine biotoxin associated with red tide. OA was coupled to BSA and OVA by carbodiimide reaction. OA-BSA as immunogen were injected in BALB/c mice. Titres of the antisera against OA were determinated using OA-OVA as coating ligand by ELISA method. The spleen cells of immunized mice were fused with Sp2/O cells. After cloning, four hybridoma cell strains stably produced anti-OA monoclonal antibody were obtained. The monoclonal antibody were produced by the mouse ascites method. The competitive indirect ELISA for okadaic acid in shellfish was established. Under optimal condition, the detection limit of OA was 31.2 ng/ml and the recovery was 87%-112%, with a mean coefficient of variation of 8.1.

[Biotoxicity of zinc in the marine sediment to amphipod Grandidierella japonica].

The utility of simultaneously extracted metals/acid-volatile sulfide (SEM-AVS) differences was investigated to explain the biological toxicity of zinc in the sediments to benthic organisms exposed in the laboratory to sediments. Amphipod Grandidierella japonica was selected to 10-day acute toxicity test for this purpose. The investigation results showed that when the molar difference between SEMZn and AVS (i.e., SEMZn-AVS) was < 0 mumol/g, the concentration of zinc in the sediment interstitial water was low and few toxic effects were observed. Conversely, when SEMZn-AVS exceeded 0 mumol/g, a dose-dependent increase in the relative concentration of zinc in the pore water was detected and apparent organisms toxic effects were observed. Together, the chemical data from this study compare with observations made in short-term exposures and thus support the use of AVS as a normalization phase for predicting toxicity in metal-contaminated sediments.