Objective To know the cause for contamination of drinking water in a hotel. Methods Samples were taken from the reservoir 1 h, 14 h, 22 h and 33 h after contamination and the perceptible character, chemical and bacteriological test were done by using the methods in Analytical Methods for Water and Sanitary Standard for Drinking Water Quality(2001). Results The turbidity increased at 14 h after contamination and the highest level reached 3.82 NTU. The residual chlorine in tap water from the reservoir was less than 0.05 mg/L, the total count of bacteria was 940 cfu/ml, the total coliform bacteria was more than 1 600 MPN/100 ml and fecal coliforms was 130 MPN/100 ml. Conclusion The contamination of drinking water in the investigated hotel is caused by drinking water reservoir leakage, so more attention must be paid to the contamination of drinking water reservoir.

Objective To characterize the dimerization and the antigenicity of the ORF2 polypep-tide of hepatitis E virus (HEV, genotype 4). Methods HEV ORF2 gene was cloned from the serum of a patient with hepatitis E. The genotype was determined by sequencing. Three ORF2 polypeptides differing in size and other polypeptides with point mutations were produced in E. coli. The recombinant polypeptides were purified and analyzed by SDS-PAGE and Western blot. Results The ORF2 polypeptide containing 459-607 amino acid formed homedimer even in 8 mol/L urea. The truncated polypeptides containing amino acid 472-607 or 459-594 formed monomer only. The mutations at amino acid 562 or 595 disrupted the ho-modimer, whereas the mutations at amino acid 476 or 580 did not. Anti-HEV from hepatitis E patients only reacted with the homodimer form of the polypeptide 459-607 and did not react with monomer or tnmcated pol-ypeptides. Conclusion The amino acid 459-607 of HEV ORF2 is essential for dimerization of the ORF2 polypeptide. Residues at amino acid 562 and 595 are critical for the dimerization. The antigenicity of the polypeptide 459-607 mainly depends on its homodimer form.

To study the potential molecular mechanism of tumor angiogenesis in its microenvironment, we investigated the effects of HepG2 conditioned medium on the proliferation of vascular endothelial cell and vascular angiogenesis in our laboratory. Human umbilical vein endothelial EA. hy926 cells were co-cultured with HepG2 conditioned medium in vitro. The proliferation and the tubulogenesis of EA. hy926 cells were detected by teramethylazo salt azole (MTT) and tube formation assay, respectively. The results showed that the survival rate of the EA. hy926 cells was significantly increased under the co-culture condition. HepG2 conditioned medium also enhanced the angiogenesis ability of EA. hy926 cells. In addition, the expressions of intracellular VEGF and extracellular VEGFR (Flk-1) were regulated upward in a time-dependent manner. In conclusion, the proliferation of vascular endothelial cells and Vascula angiogenesis were improved under the condition of indirect co-culture.
Carcinoma, Hepatocellular ; pathology ; Cell Proliferation ; Coculture Techniques ; Culture Media, Conditioned ; Endothelial Cells ; cytology ; Hep G2 Cells ; Human Umbilical Vein Endothelial Cells ; Humans ; Liver Neoplasms ; pathology ; Neovascularization, Pathologic ; Tumor Microenvironment ; Vascular Endothelial Growth Factor A ; metabolism ; Vascular Endothelial Growth Factor Receptor-2 ; metabolism

Objective:To explore the HIV-1 drug resistance in patients with HIV/AIDS in Guilin city following the failure of antiretroviral treatment (ART).Methods:Plasma samples were collected from patients in Guilin who had received ART for more than 1 year and had a HIV viral load greater than or equal to 1 000 copies/ml from January 2019 to December 2023, and demographic information was also collected for HIV-1 genotype subtype analysis and drug resistance testing to determine the resistance mutation loci and the susceptibility of the strains to drugs.Results:A total of 766 patient samples with failed ART collection and successful amplification were collected, of which 536 (69.97%, 536/766) were male, with an average age of 53 years; a total of 8 HIV-1 subtypes were detected, with CRF01_AE (80.55%, 617/766), CRF07_BC (11.10%, 85/766) and CRF08_BC (6.92%, 53/766) predominated. The drug resistance analysis showed that the HIV-1 drug resistance rate was 34.86% (267/766), including nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitor (PI), with dual resistance to NRTIs/NNRTIs (48.31%, 129/267) and NNRTIs resistance (43.07%, 115/267) predominantly. A total of 37 resistance mutation sites were detected, 14 NRTIs-associated mutation sites mainly included M184V/I (47.57%, 127/267), K65R (18.73%, 50/267), K70E/N/T/G/R (13.11%, 35/267), etc., and 18 NNRTIs-associated mutation sites mainly included K103 N/R (56.93%, 152/267), V179 D/E/T (21.72%, 58/267), G190C/S/Q (17.23%, 46/267), and V106I/M (16.85%, 45/267), etc.; and 5 PIs-associated mutation sites was the highest with L10V/I mutation rate (3.00%, 8/267).Conclusions:HIV/AIDS patients in Guilin have shown favorable outcomes in antiviral therapy, with a relatively low overall incidence of drug resistance. However, it is essential to enhance surveillance to reduce the spread of drug-resistant strains in the future.

OBJECTIVETo understand the molecular characteristics of a dengue virus outbreak in China-Myanmar border region, Yunnan province, 2015 and provide etiological evidence for the disease control and prevention.

METHODSSemi-nested RTPCR was conducted to detect the capsid premembrane (CprM) gene of RNA of dengue virus by using dengue virus NS1 positive serum samples collected in Mengdin township, Gengma county, Yunnan province in July, 2015. Some positive samples were then detected by using PCR with specific primers to amplify the full E gene. The positive PCR products were directly sequenced. Then sequences generated in this study were BLAST in NCBI website and aligned in Megalign in DNAstar program. Multiple sequence alignments were carried out by using Mega 5.05 software based on the sequences generated in this study and sequences downloaded from GenBank, including the representative strains from different countries and regions. Phylogenetic trees were constructed by using Neighbor-Joining tree methods with Mega 5.05 software.

RESULTSTwenty one of 25 local cases and 10 of 14 imported cases from Myanmar were positive for DENV-1. Eight serum samples were negative for dengue virus. A total of 13 strains with E gene (1485 bp), including 8 local strains and 5 imported strains, were sequenced, which shared 100% nucleotide sequence identities. Twelve strains with CprM gene (406 bp) from 9 local cases and 3 imported cases shared 100% nucleotide sequence identities. Phylogenetic analyses based on E gene showed that the new 13 strains clustered in genotype I of dengue virus and formed a distinct lineage.

CONCLUSIONSThis outbreak was caused by genotype I of DENV-1, which had the closest phylogenetic relationships with dengue virus from neighboring Burma area. Comprehensive measures of prevention and control of dengue fever should be strengthened to prevent the spread of dengue virus.

Capsid Proteins ; China ; epidemiology ; DNA Primers ; Databases, Nucleic Acid ; Dengue ; epidemiology ; virology ; Dengue Virus ; genetics ; Disease Outbreaks ; Genotype ; Humans ; Myanmar ; epidemiology ; Phylogeny ; Polymerase Chain Reaction ; Sequence Alignment ; Software