[Comparison of three HIV antibody confirmatory assay kits in confirming early HIV infection].

OBJECTIVE: This study was to compare the performance of three HIV antibody confirmatory assay kits in confirming early HIV infection. METHODS: Five HIV antibody-positive plasma specimens were ten-fold serially diluted and then detected by ELISA. The above diluted specimens were detected with the following three HIV antibody confirmatory assay kits to analyze their sensitivity, including Wantai-RIBA (Recombinant immunoblot assay, Beijing Wantai Biological Pharmacy, China), MP-WB (HIV Blot 2.2 WB, MP Biomedicals Asia Pacific Pte. Ltd., Singapore) and INNO-LIA (INNO-LIA(TM) HIV I/II Score, Innogenetics N.V., Belgium), respectively. These kits were further used to detect 48 ELISA-reactive specimens from 11 sets of HIV seroconversion specimens (a total of 48 samples) which were previously detected as HIV antibody-positive by ELISA. RESULTS: When 5 samples were diluted to 100 fold, Wantai-RIBA still can detect them positive. Among the 48 HIV antibody-positive specimens detected with ELISA, the confirmation positive rate for Wantai-RIBA, MP-WB and INNO-LIA were 97.92% (47/48), 81.25% (39/48) and 91.67% (44/48), respectively. There was statistically significant difference between the confirmatory results of Wantai-RIBA and MP-WB (χ(2) = 6.13, P < 0.05), as well as between those of INNO-LIA and MP-WB (χ(2) = 5.48, P < 0.05); however, there was no statistically significant difference between those of Wantai-RIBA and INNO-LIA (χ(2) = 1.33, P > 0.05). For other six HIV seroconversion panels containing indeterminate specimens, the average seroconversion period of time for Wantai-RIBA, MP-WB and INNO-LIA were 0.7, 13.3 and 3.7 days, respectively. CONCLUSION: Compared with MP-WB, Wantai-RIBA and INNO-LIA could reduce the window period to confirm early HIV infection.

Estimation of HIV-1 incidence among five focal populations in Dehong, Yunnan: a hard hit area along a major drug trafficking route.

BACKGROUND: Since 1989 when the first 146 HIV positives in China were identified, Dehong Prefecture had been one of the areas hardest-hit by HIV in China. The local and national governments have put substantial financial resources into tackling the HIV epidemic in Dehong from 2004. The objective of this study was to track dynamic changes in HIV-1 prevalence and incidence among five focal populations in Dehong and to assess the impact of HIV prevention and control efforts. METHODS: Consecutive cross-sectional surveys conducted in five focal populations between 2004 and 2008. Specimens seropositive for HIV were tested with the BED IgG capture enzyme immunoassay to identify recent seroconversions (median, 155 days) using normalized optical density of 0.8 and adjustments. RESULTS: From 2004 to 2008, estimated annual HIV incidence among injecting drug users (IDUs) decreased significantly [from 15.0% (95% CI = 11.4%-18.5%) in 2004 to 4.3% (95% CI = 2.4%-6.2%) in 2008; trend test P < 0.0001]. The incidence among other focal populations, such as HIV discordant couples (varying from 5.5% to 4.7%), female sex workers (varying from 1.4% to 1.3%), pregnant women (0.1%), and pre-marital couples (0.2 to 0.1%) remained stable. Overall, the proportion of recent HIV-1 infections was higher among females than males (P < 0.0001). CONCLUSIONS: The HIV epidemic in Dehong continued to expand during a five-year period but at a slowing rate among IDUs, and HIV incidence remains high among IDUs and discordant couples. Intensive prevention measures should target sub-groups at highest risk to further slow the epidemic and control the migration of HIV to other areas of China, and multivariate analysis is needed to explore which measures are more effective for different populations.

[Evaluation of BED-CEIA assay with dried blood spot specimens in China].

UNLABELLED: OBJECTIVE; To study the feasibility of using dried blood spot (DBS) specimens in BED-CEIA assay and to estimate the HIV-1 incidence with DBS in China. METHODS: 10 313 participants from 27 voluntary counseling and testing (VCT) sites were enrolled in this study. Both plasma and DBS specimens were collected. 349 eligible pairs of HIV-1 positive specimens confirmed by Western Blot were available for BED-CEIA and the results compared. Negative control, low positive control, high positive control and calibrator in DBS were used to evaluate the stability and repeatability of the detection results of DBS specimens. RESULTS: Of the total HIV positives, 294 and 53 participants were tested as long-term or recent HIV infections by both DBS and plasma specimens. Two participants showed different results from DBS and plasma specimens, but their final An values were close to the cutoff value of BED-CEIA assay. The concordance rate between the two types of specimens was 99.43% and the R2 linear of the stability and repeatability results of DBS specimens reached 0.9551 and 0.95, respectively. CONCLUSION: Although some individual specimens showed different results, the incidence rates calculated from both types of specimen were equivalent. DBS specimens were suitable for estimating the HIV incidence and could be popularized in China. However, further studies regarding window period and adjustment coefficients of BED-CEIA assay are needed.

[The preparation and characterization of sol-gel derived zinc modified carbonated hydroxyapatite].

OBJECTIVE: To prepare zinc-modified carbonated hydroxyapatite (Zn-CHA) coating material via sol-gel method and explore the influence of zinc substitution on physical and chemical properties of biomaterial samples. METHODS: Two kinds of samples with different zinc content and Ca/P molar ratio were prepared. One was fabricated with 4% zinc and the Ca/P molar ratio was 1.67. Another was prepared with 8% zinc and the (Ca+Zn)/P molar ratio was 1.67. The coating samples were characterized by X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM). Furthermore, the zinc ions releasing ability of the coating samples were investigated by atomic absorption spectroscopy (AAS). RESULTS: XRD results revealed that the coating samples contained hydroxyapatite phase. After determination by FTIR, the biomaterial samples were found to contain carbonate and resemble biological apatites. High homogeneous and porous surfaces of coating samples were observed in SEM micrographs. According to the results of dissolution test, zinc was incorporated into hydroxyapatite lattice structure or surface absorbed when calcium was insufficient or sufficient respectively. CONCLUSION: The results demonstrate that phase-pure zinc-modified carbonated hydroxyapatite might be prepared through simple sol-gel method and have favorable antibacterial effect.

[The experimental study on biodegradable gel membrane applied to prevention of postoperative adhesion of abdominal cavity surgery].

OBJECTIVE: To develop a new type of anti-adhesion gel membrane and explore its applying technique. METHODS: 24 adult New Zealand white rabbits were used for the experiment research project, the animals were divided into two groups: the experiment group (18 adult New Zealand white rabbits) and the control group (6 adult New Zealand white rabbits). The animal models were established via the abdominal cavity. The biodegradable gel membrane was covered to the surface of the operating region in experimental animal group, while the 0.9% NaCL was directly rinsing the operating region in the controlled group. The specimens were collected at postoperatively week 2, 4 or 8 respectively. The samples were evaluated by global and histological observation. RESULTS: In the experiment group, a few adhed zones were observed in 2 and 4 weeks after operation, but in 8 weeks after operation, the adhesion zone was disappeared. In the control group, a few adheol zones were founded in 2 weeks after operation. In 4 weeks after operation, the adhed zone become conspicuously emerged. In 8 weeks after operation, the cicatri band was occurred. CONCLUSION: The biodegradable gel membrane usd into the postoperative abdominal cavity is effective and easy to manipulate, and it could be used as a high-effect, cheap drug of anti-adhesion in operation for surgeons.