[Determination of electron density in atmospheric pressure radio frequency dielectric barrier discharges by Stark broadening].

The use of high frequency power to generate plasma at atmospheric pressure is a relatively new development. An apparatus of atmospheric pressure radio frequency dielectric barrier discharge was constructed. Plasma emission based measurement of electron density in discharge columns from Stark broadening Ar is discribed. The spacial profile of electron density was studied. In the middle of the discharge column, as the input power increases from 138 to 248 W, the electron density rises from 4.038 x 10(21) m(-3) to 4.75 x 10(21) m(-3).

The manual Polybrene test has limited sensitivities for detecting the Kidd blood group system.

BACKGROUND AND OBJECTIVES: The Kidd system antibodies, if undetected, can cause immediate or delayed hemolytic transfusion reactions as well as hemolytic disease of the newborn. There have been anecdotal reports about the inefficiency of the manual Polybrene test in detecting these antibodies. Here, we sought to determine the sensitivity of the manual Polybrene test in detecting anti-Jk(a) and anti-Jk(b) antibodies and Jk(a) and Jk(b) antigens. MATERIALS AND METHODS: Ten archived anti-Jk(a)/Jk(b) antibody positive human sera were examined by both the manual Polybrene test and the indirect antiglobulin test using polyspecific antibodies, monospecific anti-IgG antibodies and anti-C3 antibodies. Furthermore, 40 randomly selected donor blood samples were collected and phenotyped for the frequencies of Jk(a) and Jk(b) antigens using the manual Polybrene test and the indirect antiglobulin test. The results from these tests were further confirmed by saline tube tests. RESULTS: The manual Polybrene test displayed an overall sensitivity of 60% in detecting anti-Jk(a) and anti-Jk(b) antibody. Specifically, it had a sensitivity of 57.14% for anti-Jk(a) antibody and a sensitivity of 66.7% for anti-Jk(b) antibody. Furthermore, the manual Polybrene test exhibited a sensitivity of 46.15% for Jk(a) antigen and a sensitivity of 77.42% for Jk(b) antigen. CONCLUSION: The manual Polybrene test has a very low sensitivity in detecting anti-Jk(a) and anti-Jk(b) antibody, especially anti-Jk(a) antibody. It is also a very insensitive test for detecting Jk(a) antigen.

Genetic Susceptibility to Norovirus GII.4 Sydney Strain Infections in Taiwanese Children.

BACKGROUND: A comprehensive evaluation of associations between the susceptibility to norovirus infections and histo-blood group antigens is not available in the Taiwanese population, in which the nonsecretor phenotype is absent. METHODS: A 1:1 matched case-control study was conducted in northern Taiwan from February 2013 to December 2014 when an epidemic of norovirus infection occurred. Cases were children <18 years old who were hospitalized because of diarrhea and were found to have laboratory-confirmed norovirus infections. Controls were healthy children matched to the cases by age and gender. The norovirus genotype was determined by polymerase chain reaction sequencing of the VP1 gene. The secretor status, Lewis antigen and ABO type were determined by characterization of genetic polymorphisms in the FUT2, FUT3 and ABO genes, respectively. RESULTS: A total of 147 case-control pairs were included. GII.4 Sydney strain was the major genotype and identified in 78.3% of the cases. The weak-secretor and Lewis-positive genotypes were less commonly identified in cases than in controls (5.4% vs. 23.1% and 79.6% vs. 89.8%, respectively). Multivariate analysis revealed that the secretor and Lewis-negative genotypes were both independent factors associated with increased risk of norovirus infections [matched odds ratio: 6.766, 95% confidence interval (CI): 2.649-17.285, P < 0.0001 and matched odds ratio: 3.071, 95% confidence interval [CI]: 1.322-7.084, P = 0.0085, respectively]. The ABO types were not significantly related to norovirus infections (P > 0.05). CONCLUSION: The weak-secretor genotype and the Lewis antigen-positive genotype were both protective factors against severe norovirus gastroenteritis during the GII.4 Sydney strain epidemic in Taiwan.

[Analysis of DC-SIGN and DC-SIGNR genetic polymorphism in Chinese Han population].

OBJECTIVE: To understand the genetic polymorphism of DC-SIGN's and DC-SIGNR's neck regions in normal Chinese Han population, and to obtain the genetic data of the two loci in Chinese Han population. METHODS: The genotypes and alleles of repeat sequences of DC-SIGN and DC-SIGNR neck region were typed by PCR, agarose gel electrophoresis and sequencing. Polymorphism information content (PIC) of DC-SIGNR was calculated. RESULTS: DC-SIGN genetic polymorphism was rare. Allele 7 was most and its frequency was 0.9808. 4-, 5-, 6- and 8- alleles were also found, although their frequencies were very low. Caucasians had only 6- and 8- allele mutants; DC-SIGNR genetic polymorphism was high, its PIC was 0.5312, 4-,5-,6-,7-,8-,9- alleles and 16 genotypes were found in normal Chinese Han population. The differences of 6/5,7/4,7/5,7/6,7/7,9/5,9/7,9/9 genotypes distribution and 5-,6-,7-,9- alleles frequency between normal Chinese Han population and Caucasian population were all extremely distinct (P<0.01). The inserted mutation seemed more in Chinese Hans than Caucasian population. CONCLUSION: DC-SIGN and DC-SIGNR genotypes and alleles distribution in Chinese Han population are significantly different from Caucasian population and with Chinese own population genetic characteristics, compared with Caucasians.

Annexin A2, up-regulated by IL-6, promotes the ossification of ligament fibroblasts from ankylosing spondylitis patients.

BACKGROUND: Annexin A2, a calcium-dependent phospholipid binding protein, is involved in osteogenesis. The objective of the present study was to explore the expression of Annexin A2 in spinal ligament tissues (LT) of ankylosing spondylitis (AS) patients and determine its pathological functions. METHODS: mRNA and protein expression of Annexin A2 was detected by real-time PCR and Western blotting, respectively. Interleukin-6 (IL-6) concentration in serum was assessed by enzyme linked immunosorbent assay. Alkaline phosphatase (ALP) activity was measured with ALP activity kit on a microplate reader. RESULTS: mRNA and protein expression of Annexin A2 in LT, and IL-6 concentration in serum were significantly increased in AS patients. Moreover, exogenous IL-6 treatment significantly up-regulated Annexin A2 expression and ALP activity. Silencing of Annexin A2 expression significantly ameliorated IL-6-induced ossification of fibroblasts from AS patients, as indicated by ALP activity, expression of proteins associated with osteogenic differentiation, including bone morphogenetic protein-2, osteocalcin and osterix, and the ratio of osteoprotegerin to receptor activator of NF-κB ligand. Further MEK inhibitor experiments suggested that Annexin A2 may exert its function through extracellular signal-related kinase pathway. CONCLUSIONS: Annexin A2, up-regulated by IL-6, may promote ligament ossification of AS patients.

[Evaluation of the effect for ffh gene silencing on the aciduricity of fluoride resistant Streptococcus mutans].

PURPOSE: To analyze the effect of ffh gene silencing on the aciduricity of fluoride resistant Streptococcus mutans in vitro. METHODS: By using electroporation, UA159-FR was transformed and combined with targeted site of ffh gene sequence, and the best piece of siRNA for fluoride resistant Streptococcus mutans was screened. In different values of pH of BHI, they were cultured for 24 hours with UA159-FR respectively, and then centrifugated to determine the pH and OD600. SPSS17.0 software package was used to analyze the data. RESULTS: The aciduricity of UA159-FR had significant differences compared with ffh gene silencing for UA159-FR in δpH (P<0.05), and the former was higher than the latter. At pH=3.5-5.0, P<0.01; at pH=5.5-7.5, P<0.05. Significant differences were noted in OD600 and their growth tendency were similar. CONCLUSIONS: The aciduricity of fluoride resistant Streptococcus mutans has significant effect when the ffh gene is silenced.

[Serological survys on anti-H1N1 IgG of blood donors in Dongguan].

OBJECTIVE: To access the sustained immune effect in influenza A H1N1 vaccine vaccinated-blood donors as well as the level of anti-H1N1 IgG in unvaccinated-blood donors in order to provide reference for preventing and treating influenza A H1N1. METHODS: Anti-H1N1 IgG was detected in 1166 vaccinated-blood donors as well as 1265 unvaccinated-blood donors by ELISA method in Dongguan from January 2010 to June 2010. RESULTS: The mean positive rate and high-titer rate of anti-H1N1 IgG were 78.82% and 46.57% respectively, both of which were sustained at relatively high level after reaching their peak at vaccination time of 71-90 d. The mean positive rate of anti-H1N1 IgG in unvaccinated-blood donors was 26.01%. No difference was found in the positive rate of anti-H1N1 IgG among different gender or age groups (P > 0.05). CONCLUSION: The influenza A H1N1 vaccine, with good sustained immune effect, plays an important role in preventing and treating influenza A H1N1. The positive rate of anti-H1N1 IgG in influenza A HIN1 vaccine unvaccinated-blood donors is low. Vaccination should be strengthened.

Transplantation of human umbilical cord blood mesenchymal stem cells improves survival rates in a rat model of acute hepatic necrosis.

INTRODUCTION: Stem cell-based therapies are emerging as important and promising methods in the treatment of end-stage liver disease. This study is aimed to evaluate the effects of human umbilical cord blood mesenchymal stem cell (HUCBMSC) transplantation in acute hepatic necrosis (AHN). METHODS: Green fluorescent protein (GFP)-labeled HUCBMSCs were injected into the liver of rats in which AHN was induced by carbon tetrachloride, and the migration of these cells in liver slices was evaluated from 48 hours to 4 weeks post-transplantation. The transdifferentiation status of the HUCBMSCs was evaluated using immunohistochemistry and real-time reverse transcription-polymerase chain reaction, and survival rates were statistically analyzed. RESULTS: Dispersed GFP fluorescence was observed along the portal area 48 hours after transplantation. One week post-transplantation, GFP-positive cells were found in necrotic liver areas, and GFP-positive cells persisted after 4 weeks. Immunohistochemistry and real-time polymerase chain reaction analysis showed that transplanted HUCBMSCs expressed several human liver tissue-specific markers in rats with AHN. Statistical analysis revealed that rats with AHN that were transplanted with HUCBMSCs had significantly lower death rates after 48 hours than those receiving no HUCBMSCs. CONCLUSION: HUCBMSC transplantation can significantly improve the survival of rats with AHN. The underlying mechanisms involved may include the transdifferentiation of HUCBMSCs into hepatocyte-like cells and targeted migration of these cells to liver lesion sites.

[Source and air-sea fluxes of heavy metals in the atmospheric particles of East China Sea].

From 2006 to 2007, four surveys for marine atmosphere in East China Sea were carried out included different seasons (spring, summer, autumn and winter). Based on the survey data of heavy metals in marine atmospheric particles, analyzed the source of heavy metals by the calculation of Enrichment Factors, calculated the air-sea fluxes via dry deposition. The results showed, comparing with the crustal and seawater, the heavy metals including Cu, Pb, Cd and Zn were highly concentrated, mainly from the pollutants of human activities. The fluxes of heavy metals via dry deposition were Zn [10.92 mg/(m2 x a)] > Pb [2.299 mg/(m2 x a)] > Cu [1.611 mg/(m2 x a)] > Cd [0.017 mg/(m2 x a)]. The fluxes of heavy metals in winter were highest,the summer and autumn were lower. The input of Cu, Pb, Zn and Cd from atmosphere to sea via dry deposition was 2 376 t, nearly 13% compared with the input of The Changjiang River (Yangtze River).

[Study about seroconversion of HBV NAT screening-positive crowd from blood donors].

OBJECTIVE: To investigate the characteristics of seroconversion of HBV NAT screening-positive crowd from blood donors in Dongguan city and provide reference for the safety of blood transfusion and disease prevention. METHODS: With retrospective survey, Nucleic acid testing (NAT) was used to analyze 28800 HBsAg-negative samples by ELISA from blood donors in Dongguan city from August, 2006 to August, 2007 with Roche Cobas AmpliScreen systems; and follow-up research including NAT for HBV-DNA, ELISA for HBsAg and multiple factors analysis for HBV infection was carried out on HBV NAT screening-positive crowd. RESULTS: 10 positive pooling were screened from 28800 samples; after further detection, 2 of these positive pooling were HBV-DNA negative and 8 HBV-DNA positive samples were found.The 10-week follow-up research on these 8 blood donors showed that 6 were HBV-DNA positive and HBsAg-negative at 2 weeks, 4 weeks, 6 weeks, 8 weeks, 10 weeks respectively, 1 was not HBsAg positive until 2 weeks and was positive on follow-up, and considered in "window period", 1 was HBV-DNA negative, HBsAg-negative on follow-up. Of these 8,7 were not only migrant laborers with poor condition of work, life and health but also in high risk of secondary infection for HBV, in addition they had little idea of therapy or prevention measures of HBV infection and the other 1 was HBV-DNA negative, HBsAg-negative on follow-up, who was in better condition than the above 7 donors. CONCLUSION: NAT is more sensitive than ELISA in screening HBV, but the probability of being false positive of NAT can not be ignored at the same time. On the hand, only screening HBsAg for HBV is relative limitation in high infection region of China. Some factors would have effect on the serum conversion of blood donors including the quality of work and life, therapy or prevention measures.

[Comparison of homemade and imported HbsAg ELISA kits on screening blood samples].

BACKGROUND: To evaluate homemade and imported HbsAg ELISA kits on screening blood donors. METHODS: Samples for evaluation included 120 HbsAg serum plates for the golden criteria and 400 sets of serum from blood donors in Dongguan. The samples underwent blind screening with homemade and imported ELISA kits respectively. RESULTS: The sensitivity of homemade (Xinchuang) and imported (Diasorin) HbsAg ELISA kit were 85.71% (72/84) and 100% (84/84), respectively. Their specificity was 100% (436/436) and 96.55% (421/436) respectively. The consistency of two ELISA kits was 100%. CONCLUSION: The imported ELISA kit had the highest sensitivity, but its specificity was not as good as that of homemade ELISA kit. The two kinds of ELISA kits had good repetition. The combination of the two reagents may ensure the safety of blood transfusion.