[Serological screening and analysis of clinical characteristics for celiac disease in susceptible population in Southern China].

Objective: To determine the seroprevalence of celiac disease in susceptible population, and to analyze the relationship between demographic characteristics, dietary habits, lifestyle and serological positivity so as to provide guidance for the prevention and treatment of celiac disease in Southern China. Methods: A total of 1 273 individuals who participated in Guangdong Province Health Screening Program in 2015, were selected as serologically positive subjects of celiac disease, including people with irritable bowel syndrome, colitis, diarrhea, anemia, low BMI, short stature, type 1 diabetes mellitus (T1DM), rheumatoid arthritis (RA), ankylosing spondylitis, psoriasis and bristol grade=6 or 7. All subjects were tested for serum IgA anti-tissue transglutaminase antibodies (TTGA), IgA antibodies against deamidated gliadin peptides(DGPA) and IgG against deamidated gliadin peptides (DGPG). Dietary habits, lifestyle and demographic characteristics were compared in subgroups. Results: The seroprevalence of celiac disease in susceptible population was 0.94% (95%CI 0.54%-1.64%) including 0.08% (1/1 273) for TTGA, 0.47% (6/1 273) for DGPA, and 0.39% (5/1 273) for DGPG. The seropositive rate was 3.6% (1/28) in patients with psoriasis, 2.1% (2/95) in the low BMI group, 1.9% (1/53) in T1DM group, 1.8% (3/169) in diarrhea group and 1.1% (5/463) in RA group. No significant difference was found in age, gender, high carbohydrate diet or lifestyle between the negative and the positive subjects. Conclusions: In Southern China, the seropositive rate of celiac disease is 0.94% in susceptible population, which prompts an urgent need of serological screening for early diagnosis.

[Qualitative research on factors of HIV testing among men who have sex with men in China based on Blued].

Objective: To understand the cognition and attitudes of men who have sex with men (MSM) towards HIV testing and explore in-depth reasons preventing them from testing. Methods: The function of "opinion" in Blued, a gay geo-social networking application (GSN), was adopted to collect qualitative data of ideas and attitudes towards HIV testing of the users between December 2017 and January 2018. The data was analyzed based on grounded theory approach. Results: 28 269 Blued users participated in the activity and 1 977 posted comments. Four key themes were identified, i.e. no/low risk of contracting HIV, stigmatization of HIV testing, long-term relationship and conventional impediments of HIV testing. Conclusion: The cognition and attitudes of the target population derived from the analysis of "opinion" function in Blued, such as the stigmatization of the behavior of HIV testing influencing the attitude of HIV testing, could help researchers build a more accurate detection and promotion strategy instead of a very general intervention on the public.

Association between TXNRD1 polymorphisms and anti-tuberculosis drug-induced hepatotoxicity in a prospective study.

Anti-tuberculosis drug-induced hepatotoxicity (ATDH) is a serious adverse reaction to anti-tuberculosis (TB) treatment. Thioredoxin reductase 1 (TXNRD1), encoded by the TXNRD1 gene, is an important enzyme involved in oxidant challenge. TXNRD1 plays a key role in regulating cell growth and transformation, and protects cells against oxidative damage. We investigated the association between TXNRD1 polymorphisms and ATDH susceptibility. In this prospective study, 280 newly diagnosed TB patients were followed-up for 3 months after beginning anti-TB therapy. Tag single-nucleotide polymorphisms (tag-SNPs) of TXNRD1 were selected using Haploview 4.2 based on the HapMap database of the Chinese Han in Beijing (CHB) panel. Genotyping was performed using the MassARRAY platform. Of the 280 patients enrolled in this study, 33 were lost to follow-up, 24 had ATDH, and 223 were free from ATDH. After adjusting for sex, age, smoking status, and body mass index, there were no significant differences in the allele and genotype frequency distributions of TXNRD1 SNPs between the ATDH and non-ATDH groups (all P > 0.05). The haplotype analysis showed that haplotype TCAGCC was associated with an increased risk of ATDH susceptibility [P = 0.024, OR (95%CI) = 6.273 (1.023-38.485)]. Further stratified analyses showed that the haplotype TCAGCC was associated with ATDH susceptibility in female subjects [P = 0.036, OR (95%CI) = 5.711 (0.917-35.560)] and non-smokers [P = 0.029, OR (95%CI) = 6.008 (0.971-37.158)]. Our results suggest that TXNRD1 variants may favor ATDH susceptibility in females and non-smokers. Further studies are required to verify this association.

[Prevalence and trend of overweight and obesity in children and adolescents in Guangdong province, 2002-2012].

Objective: To investigate the prevalence and trend of overweight and obesity in children and adolescents aged 6-17 years between 2002 and 2012 in Guangdong province. Methods: A total of 7 075 children and adolescents aged 6-17 years were selected in Guangdong for nutritional survey in 2002 and a total of 2 319 children and adolescents aged 6-17 years were selected in nine counties/districts of Guangdong for nutritional survey during 2009-2012 through multi-stage random cluster sampling. The body height and weight of all the children and adolescents were measured. Results: The result of 2009-2012 survey indicated the average prevalence of overweight and obesity in the children and adolescents surveyed were 7.3% and 4.5%, respectively. The prevalence of overweight and obesity were higher in boys (8.9% and 6.5%) than in girls (5.3% and 2.2%), in rural area (9.3% and 5.6%) than in urban area (4.7% and 3.2%). Children and adolescents aged 9-11 years had a higher overweight and obesity rates compared with other age groups. Compared with 2002, except for obesity rate in urban girls, the prevalence of overweight and obesity in children and adolescents obviously increased. The increase rate was higher in rural area than urban area and in boys than in girls. Conclusions: Compared with 2002, the prevalence of overweight and obesity in children and adolescents in Guangdong obviously increased. The prevalence was much higher in boys, those living in rural area and those aged 9-11 years, thus more attention should be paid to them.

[Cardiac arrhythmias in pilots under positive (+Gz) acceleration].

OBJECTIVE: To study the relationship between cardiac arrhythmias and autonomic nervous regulation in pilots under +Gz acceleration. METHOD: Dynamic ECG during +Gz exposures in 36 orthostatic intolerance pilots and 62 healthy pilots were analysed and compared. RESULT: The orthostatic intolerance pilots had obviously lower +Gz tolerance and more cardiac arrhythmias. The cardiac arrhythmias could affect +Gz tolerance. CONCLUSION: The cardiac arrhythmias under +Gz acceleration could be taken as an index of evaluating cardiovascular compensatory function and warning against acceleration (+Gz) induced loss of consciousness (G-LOC).

[Experimental studies of the protective effects of basic fibroblast growth factor and Radix Salviae Miltiorrhizae on brain injury in rats caused by repeated exposures to +Gz].

Objective. To investigate the preventive and theralseutive (therapeutic) effects of basic fibroblast growth factor (bFGF) and Radix Salviae Miltiorrhizae (RSM) on brain injury caused by repeated +Gz exposures. Method. bFGF and RSM were injected intraperitoneally into SD rats before and after repeated +Gz exposures. The contents of excitatory amino acids (EAAs), nitric oxide (NO) and the number of cell apoptosis in the brain were measured, and were compared to those of the control group and normal saline (NS) group. Result. The contents of EAAs, NO and the number of cell apoptosis were significantly higher in repeated +Gz exposures group than those in control group. The values were markedly lower in bFGF and RSM group than those in repeated +Gz exposures group and NS group. Conclusion. bFGF and RSM showed distinct preventive and therapeutic effect on the brain injury induced by repeated +Gz exposures.

[Changes of mRNA expression of IL-1beta and TNF-alpha in rat brains after repeated exposures to +Gz].

Objective. To study changes of mRNA expression of IL-1beta and TNF-alpha in rat brains after repeated exposures to +Gz. Method. Twenty conscious SD rats served as the subjects. They were randomly divided into 5 groups. Using an animal centrifuge, control rats (n = 4) were exposed to +1 Gz and experimental rats (n = 16) were exposed to +14 Gz three times, each for 45 s with 30 min interval in between. The rat brains were taken 30 min, 6 h, 24 h and 48 h after the last centrifuge run and total RNA was isolated. mRNA expression levels of IL-1beta and TNF-alpha in rat brain were measured by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). Result. mRNA expression levels of IL-1beta and TNF-alpha in rat brains taken 30 min, 6 h and 24 h after repeated +Gz exposures were significantly higher than those in control rats, but returned to normal after 48 h. Conclusion. It suggested that mRNA expressions of IL-1beta and TNF-alpha in rat brains can be stimulated by repeated +Gz exposures and the increased expression of IL-1beta and TNF-alpha may play a role in the pathologic course of brain damage induced by +Gz exposures, but the damage is reversible.

Expression of HSP70 gene in rat brain after exposures to repeated +Gz.

OBJECTIVE: To study the changes of mRNA expression of heat shock protein 70 (HSP70) in the rat brain exposed to repeated +Gz. METHOD: The mRNA expression levels of HSP70 in rat brain were measured by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). RESULT: The HSP70 mRNA expression levels in rat brains taken 30 min and 6 h after repeated +Gz exposures were significantly higher than those in control group, while the difference between the levels of control group and those of experimental rat brains taken 24 h after +Gz exposure was not significant. CONCLUSION: It is suggested that HSP70 mRNA expression in rat brain can be induced by repeated +Gz exposures and the increased HSP70 mRNA expression may play an important role in self-protection against brain damage induced by +Gz exposures.

Cell-free mercury volatilization activity from three marine caulobacter strains.

Three mercury-resistant marine Caulobacter strains showed an inducible mercury volatilization activity. Cell-free mercury volatilization (mercuric reductase) from these three marine Caulobacter strains was characterized and compared with enzyme activities determined by plasmids of Escherichia coli and Staphylococcus aureus. The temperature sensitivity of the Caulobacter mercuric reductase was greater than that of mercuric reductase from other gram-negative sources. Cell-free enzyme activity required NADH or NADPH, with NADPH functioning much better at lower concentrations than NADH. The Km for the Caulobacter enzyme was 4 microM Hg2+. Ag+ was a competitive inhibitor of Caulobacter mercuric reductase (Ki = 0.2 microM Ag+), as with previously studied enzymes. Arsenite was a noncompetitive inhibitor of the Caulobacter enzyme with a Ki of 75 microM AsO2-.

Constitutive synthesis of a transport function encoded by the Thiobacillus ferrooxidans merC gene cloned in Escherichia coli.

Mercuric reductase activity determined by the Thiobacillus ferrooxidans merA gene (cloned and expressed constitutively in Escherichia coli) was measured by volatilization of 203Hg2+. (The absence of a merR regulatory gene in the cloned Thiobacillus mer determinant provides a basis for the constitutive synthesis of this system.) In the absence of the Thiobacillus merC transport gene, the mercury volatilization activity was cryptic and was not seen with whole cells but only with sonication-disrupted cells. The Thiobacillus merC transport function was compared with transport via the merT-merP system of plasmid pDU1358. Both systems, cloned and expressed in E. coli, governed enhanced uptake of 203Hg2+ in a temperature- and concentration-dependent fashion. Uptake via MerT-MerP was greater and conferred greater hypersensitivity to Hg2+ than did uptake with MerC. Mercury uptake was inhibited by N-ethylmaleimide but not by EDTA. Ag+ salts inhibited mercury uptake by the MerT-MerP system but did not inhibit uptake via MerC. Radioactive mercury accumulated by the MerT-MerP and by the MerC systems was exchangeable with nonradioactive Hg2+.

Serial propagation of mammalian cells on gelatin-coated microcarriers.

The ability to serially propagate mammalian cells in microcarrier cultures is essential for large-scale operation. The success of such serial propagation depends on viable dissociation of cells from microcarriers and the normal growth and product formation after subsequent reinoculation. The high pH treatment developed for dissociating cells from DEAE-derivatized microcarriers was not as effective for a number of cell strains cultivated on gelatin-coated microcarriers. By prewashing the cell-laden microcarriers with buffer containing a chelating agent, bovine kidney cells, BK, human embryonic foreskin fibroblasts, FS-4, and continuous human kidney cells, TCL-598 which produces prourokinase, were viably dissociated from commercially available gelatin-coated microcarriers, Cytodex-3. Cells dissociated from microcarriers reattached and grew on micro-carriers subsequent to inoculation into subcultures. However, after subculturing, cells may attach at different rates to newly added beads and to conditioned microcarriers which cells had previously grown. It resulted in an uneven cell distribution on microcarriers and inferior growth kinetics. This effect was more profound for BK and FS-4 cells which are propagated with a low multiplication ratio. Specifically, BK cells attach to conditioned beads at a faster rate than to new beads, while FS-4 cells attach to new beads faster than to conditioned beads. Thus, for these two cell strains, a separator was used to separate the microcarriers from the suspension of dissociated cells before subsequent inoculation. For TCL-598 cells, which are propagated at a high multiplication ratio, this dissociation technique can be applied directly without the separation of dissociated cells and conditioned microcarriers. All the three cell lines tested exhibit normal growth kinetics in serial propagation on microcarriers. Furthermore, the production of prourokinase by TCL598 cells serially propagated on microcarriers was comparable to that inoculated from roller bottles.