[Genetic variation of gag gene in HIV-1 subtype B infections from Henan and Shanxi provinces of China].

The 109 whole blood samples were collected from HIV-1 infected former blood donors in Henan and Shanxi. The RNA templates were extracted from plasma and used for the full gag gene amplification and sequencing. The sequences were divided into 3 groups according to sampling year. The Entropy software was used to identify the amino acids with composition difference among different groups of amino acid sequences. The results showed that there existed 8 and 13 amino acid sites with the statistical significance difference, respectively, in sequences in year 2004 and 2005, compared to those in 2002. Among them, there existed 5 amino acid sites in two groups. Of 16 amino acid sites, the increasing polymorphism and the decreasing polymorphism along the sampling year were observed in 10 and 6 amino acid sites respectively. Of 10 sites with increased polymorphism, 8 sites were located in the CTL epitopes recognized and presented by the main HLA alleles existed in Chinese population. The 6 sites with decreasing polymorphism all existed in main domains of Gag proteins.

The impacts of current antiretroviral therapy regimens on Chinese AIDS patients and their implications for HIV-1 drug resistance mutation.

This study sought to investigate the impacts of the antiretroviral (ARV) therapy regimens currently used in Chinese HIV-1-infected individuals. Seven hundred eighteen ARV-treated and treatment-naive HIV-1-infected individuals living in seven provinces were enrolled in 2005 by a multistage sampling approach according to a national cross-sectional survey program on HIV-1 drug resistance. All patients were investigated clinically, and CD4+ T cell counts and HIV-1 viral loads were measured while genotyping for drug resistance was determined by a home brew nested PCR. Viral inhibition in ARV-treated individuals was higher than that in ARV treatment-naive individuals. The overall prevalence of drug-resistant mutations was 37.8%. Higher frequencies of mutations in ARV-treated and drug withdrawal groups were found than in the ARV treatment-naive group (P<0.01). Of the four regimens currently used, the D4T/3TC/NVP regimen showed a higher-level viral inhibition. No statistical significance was found among the four regimens in drug-resistant mutations. The rate of resistance-associated mutations to non-nucleotide reverse transcriptase inhibitors (NNRTIs) was higher than that to nucleotide reverse transcriptase inhibitors (NRTIs) (P<0.01). The most common mutations conferring resistance to NNRTIs were K103N, Y181C and G190A, representing 56.5, 30.4 and 14.5%, respectively. Furthermore, higher viral inhibition and a lower rate of drug-resistant mutations were achieved in the good compliance group. This study revealed an efficient viral inhibition achieved with the current first-line regimens in China. Most of these regimens could rapidly result in emergence of drug-resistant mutations, suggesting that a second-line ARV therapy is urgently needed and that the compliance with treatment must be emphasized during long-term treatment.

Development and optimization of a method for analysis of the products from the transesterification of dimethyl carbonate and phenol.

A high-purity sample of methyl phenyl carbonate (MPC) was obtained by developing a novel reaction route followed by a series of separation and purification procedures. Identification and quantification of the MPC sample (98.32%) was performed by a gas chromatography-mass spectrometry and Karl Fisher titration. The laboratory-prepared MPC was then used as a standard to optimize quantitative analysis of the products synthesized by transesterification of dimethyl carbonate and phenol. The advantage of the improved method was that MPC can be quantified directly rather than being calculated by subtracting the yield of diphenyl carbonate (DPC) and by-product anisole from the conversion of dimethyl carbonate (DMC). The resulting method was validated for linearity, precision, accuracy, detection limit, and quantification limit. With the improved method, simultaneous accurate quantification of DMC, MPC, DPC, phenol, and anisole in the transesterification products can be achieved. This enables evaluation of the activity and selectivity of different catalysts and control of the reaction processes.

[Detection of hantaan virus from gamasid mite and chigger mite by molecular biological methods].

OBJECTIVE: To study the proliferation and location of hantaan virus (HV) in gamasid mites and chigger mites. METHODS: HV RNA in gamasid mites and chigger mites were detected by reverse transcription, polymerase chain reaction (RT- PCR) and in situ hybridization. RESULTS: The smallest quantity of mite from which HV RNA could be detected was 5 mites group. The titers of -and proliferated in mites HV RNA could be found in ovary cells and dug cells of gamasid mites and chigger mites by in situ hybridization. CONCLUSIONS: The results showed that HV could be trans-stadially transmitted and proliferated in mites, and HV always located in ovary and dug organs of mites. These results provide direct evidence at molecular level for the role of gamasid mites and chigger mites as vectors in transmission of HV.