ABSTRACT
<p><b>OBJECTIVE</b>This article was to explore the impact of temperature on hepatitis B virus infectivity.</p><p><b>METHODS</b>HBV positive serum with a HBV DNA titer of 1.33 × 10(8) copies/ml was aliquots into 23 Ep tubes with 1.5 ml, 100 µl in one tube.15 tubes were incubated at 37, 56 and 65°C for 0, 30, 60, 120 and 600 minutes, respectively. The other 8 tubes were incubated at 98°C for 0, 5, 10 and 30 minutes, respectively. Post-treated serum at all time points were selected to infect HepG-2 cell. When 18 hours after infection, these cells were extensively washed with phosphate buffered saline. Cells were harvested after the addition of fresh culture medium to culture cells for 48 hours. HBV DNA was detected by FQ-PCR.</p><p><b>RESULTS</b>HBV DNA was detected in cells that were infected by serum at 37°C and 56°C for 30, 60, 120 and 600 minutes, respectively. The titers for the cells incubated at 37°C were (4.85 ± 1.71) × 10(5), (3.85 ± 1.76) × 10(5), (1.67 ± 0.67) × 10(5), (7.86 ± 1.03) × 10(4) copies/ml, and those for the cells incubated at 56°C were (4.01 ± 0.16) × 10(5), (9.77 ± 0.97) × 10(4), (6.36 ± 0.65) × 10(4), (5.05 ± 0.24) × 10(3) copies/ml at different incubation time points. For the cells incubated at 65°C for 60 and 120 minutes, HBV DNAs were (5.15 ± 7.28) × 10(3) and (7.56 ± 10.60) × 10(2) copies/ml, respectively, which were much lower than those in the controls cells ((6.79 ± 1.48) × 10(5) copies/ml). The results of HBV DNA were different (F = 104.4, P < 0.001) in groups treated with different temperature, and results of HBV DNA were also different (F = 144.0, P < 0.001) in groups processed for different period of time. Temperature and processing time had interaction (F = 23.6, P < 0.001). After heating at 98°C for 10 minutes and boiling for 5 minutes, the HBV DNA copy number ((3.02 ± 4.26) × 10(2), (4.31 ± 6.09) × 10(2) copies/ml) in infected cells decreased by about 10 folds than that in the control group ((6.79 ± 1.48) × 10(5) copies/ml). HBV DNAs were not detected in cells that were infected by serum which was heated at 98°C for 30 minutes and boiled for 10 minutes.</p><p><b>CONCLUSION</b>The infectivity of HBV serum in vitro was relatively stable at low temperature, and it would lose its infectivity in short period of time at high temperature.</p>
Subject(s)
Humans , Hep G2 Cells , Hepatitis B virus , Virulence , Physiology , Hot Temperature , Serum , VirologyABSTRACT
<p><b>OBJECTIVE</b>To study the association between cholesteryl ester transfer protein (CETP) gene polymorphism and insulin resistance in type 2 diabetes.</p><p><b>METHODS</b>CETP-TaqIB gene was genotyped with polymerase chain reaction-restriction enzyme fragment polymorphism analysis in 108 patients with type 2 diabetes and in 60 normal controls. Plasma lipids, fasting insulin, insulin sensitivity index and insulin resistance index were determined in 108 patients with type 2 diabetes.</p><p><b>RESULTS</b>The distribution of CETP-TaqIB genotypes and B1B2 allele frequency in the patients with type 2 diabetes were similar to that in general population. High density lipoprotein cholesterol (HDL-C), apolipoprotein A1(apoA1) and insulin sensitivity index (ISI) levels were significantly higher in B2B2 genotype than in B1B1 genotype. Fasting insulin (FINS) and Homeostasis model assessment-insulin resistance (HOMA-IR) levels were significantly lower in B2B2 genotype than in B1B1 genotype. No significant differences in triglyceride (TG), total cholesterol(TC),low density lipoprotein cholesterol (LDL-C), apolipoprotein B (apoB) levels were observed among different CETP-TaqIB genotype groups. By multivariate analysis, the determinants of ISI and HOMA-IR were body mass index (BMI), TC, HDL-C and CETP-TaqIB genotype.</p><p><b>CONCLUSION</b>The CETP-TaqIB genotype is independently associated with insulin resistance and lipid metabolism. It may be an important risk factor of insulin resistance in type 2 diabetes.</p>