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The regulations governing the discharge of marine aquaculture wastewater are becoming increasingly stringent, and the problems of nitrogen and phosphorus pollution and antibiotic residues in wastewater are serious. Microalgae-based treatment with the dual benefits of wastewater purification and microalgae resource recycling was regarded as the most promising technology in aquaculture wastewater treatment. Isochrysis galbana and Chlorella sp. were chosen to investigate antibiotic and nutrient removal mechanisms from aquaculture wastewater. FLO addition stimulated microalgae growth at low FLO concentrations (0.1 and 1 mg/L) but inhibited growth at 10 mg/L. The removal efficiency of DIN by Chlorella sp. and I. galbana after 7 days of cultivation was 66.4% and 25.8%, respectively. Linear curves were obtained between DIN concentration and cultivation duration, remove constant (k) increased as FLO concentration increased from 0 to 10 mg/L, and the highest value of k was obtained in both the Chlorella sp. and I. galbana groups at 10 mg/L. DIP concentrations in FLO-contained simulated aquaculture wastewater decreased sharply with the cultivation of Chlorella sp. and I. galbana, and DIP removal rate increased as FLO concentration increased. When the initial concentration of FLO was 0.1 mg/L, biodegradation by I. galbana accounted for 86.67% of FLO removal. In contrast, FLO removal with biodegradation and biosorption by Chlorella sp. was 89.74% and 3.72%, respectively. Furthermore, Chlorella sp. grown in MPBR demonstrated superior capability for antibiotic-containing marine aquaculture wastewater purification, with average removal rates of DIN and DIP of 81.2% and 100%, respectively. The high removal rate is related to membranes which can improve microalgae performance by decoupling SRT and HRT. For microalgae-based aquaculture wastewater, ammonia was the most crucial nitrogen source, followed by nitrate. These findings serve as a theoretical foundation for developing microalgae-based aquaculture wastewater treatment technology and eliminating antibiotics in aquaculture.
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Chlorella , Microalgas , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Aquicultura , Biomassa , Chlorella/metabolismo , Microalgas/metabolismo , Nitrogênio/análise , Nutrientes , Tianfenicol/análogos & derivados , Águas Residuárias/químicaRESUMO
OBJECTIVE@#To compare the clinical effects of three different methods of binding multi-fold rib graft, iliac bone graft and titanium mesh graft in tuberculosis of thoracic vertebra by approach of transverse rib process.@*METHODS@#A hundred and seven patients with tuberculosis of thoracic vertebra received surgical treatment from January 2010 to December 2016 were retrospectively analyzed. The patients were divided into three groups according different methods of bone graft. The surgical approach of the transverse rib process was used in all 107 patients, after thoroughly remove the necrotic tissue of tuberculosis, three different bone grafts were used respectively including iliac bone graft (36 cases, group A), binding multi-fold rib graft (35 cases, group B), titanium mesh bone graft (36 cases, group C). Perioperative indexes, the time required for bone graft during operation, intraoperation blood loss, the loss rate of the anterior edge of the lesion, Cobb angle, postoperative bone graft fusion time, spinal nerve recovery and Oswestry Disability Index were compared among three groups.@*RESULTS@#All the patients were followed up for 13 to 24 months, and the operation time required for bone graft was (23.2±4.1) min in group A, (23.8± 4.4)min in group B, and (25.5±4.2) min in group C, with no statistically significant difference among three groups (@*CONCLUSION@#The approach of transverse rib process for debridement of lesions can effectively treat tuberculosis of thoracic vertebra by binding multi-fold rib graft, iliac bone graft and titanium mesh graft, but binding multi-fold rib graft can effectively avoid iliac bone donor complications, and is an effective alternative to iliac bone graft, which is worth popularizing.
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Humanos , Transplante Ósseo , Vértebras Lombares , Estudos Retrospectivos , Costelas/cirurgia , Fusão Vertebral , Telas Cirúrgicas , Vértebras Torácicas/cirurgia , Titânio , Resultado do Tratamento , Tuberculose da Coluna Vertebral/cirurgiaRESUMO
Objective Using substituted benzyl piperazine as the raw material to design and synthesize new piperazine deriva-tives with protein tyrosine kinase(PTK)inhibitory activity. Methods Benzoic acid was used as starting compound to synthesize a key intermediate,2-chloroethyl benzoate,and the target compounds were synthesized by further reaction of the key intermediate with different substituted benzyl piperazine derivatives.Enzyme-linked immunosorbent assay(ELISA)was used to test the PTK inhibitory activity of the compounds.Results Fifteen new compounds were synthesized and their structures were verified by IR,1H NMR,MS, and elemental analysis.The PTK inhibitory activity of 3h and 3o was stronger than that of the other compounds.Conclusion The syn-thetic method is simple,and the raw materials are cheap and readily available.Compounds 3h and 3o showed relatively higher PTK in-hibitory activities.
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Objective Few studies are reported on the factors influencing the selection of the surgical access for adenocarci-noma of the esophagogastric junction (AEG). This study aimed to investigate the factors influencing the selection of the surgical access for CT type-ⅡAEG. Methods We retrospectively analyzed 118 cases of CT type-ⅡAEG surgically treated in the Second Affiliated Hospital of Zhengzhou University and Henan Tumor Hospital from January 2015 to January 2017,92 via the abdominal access and the other 26 via the thoracoabdominal access. We performed univariate and multivariate logistic regression analyses on the factors that might influence the surgical approaches,such as gender,body mass index (BMI),degrees of the epigastric angle,pathological classifica-tion,and clinical stages. Results Logistic regression analysis showed that the degree of the epigastric angle was an independent fac-tor influencing the selection of the access of AEG (OR=0.250,95% CI: 0.098-0.639) (P<0.05). Conclusion In the surgical treatment of CT type-ⅡAEG,the abdominal access is preferable for patients with the epigastric angle> 90 degrees and the thoracoab-dominal access is recommended for those with the epigastric angle≤90 degrees.
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<p><b>OBJECTIVE</b>To express and purify the mouse endothelial cell-targeted recombinant Notch ligand protein mD1R, and to investigate its effect on hematopoiesis after carbon tetrachloride damage.</p><p><b>METHODS</b>PCR was performed to clone and construct the expression vector pET22b(+)-mD1R. The mD1R successfully transformed into E. coli was induced by IPTG, and purified with Ni-beads affinity chromatography. The target protein was detected by SDS-PAGE. The fluorescence-activated cell sorting analysis (FACS), cell adhesion test, immunofluorescence staining and quantitative real-time PCR were employed to detect the endothelial cell-targeted and Notch signaling-activated biological characteristics of mD1R. The carbon tetrachloride mouse model was established to observe the effects of mD1R on the hematopoietic stem cell (HSC), myeloid cells and lymphoid cells by flow cytometry. The LinScal-1c-Kit cells were sorted by magnetic bead, FACS was performed to analyze the cell cycle, and RT-PCR was employed to observe the expression of interleukin (IL)-10.</p><p><b>RESULTS</b>The prokaryotic expression vector was successfully cloned and constructed. The purity and the activity were confirmed in mD1R recombinant protein. The purified mD1R activated the Notch signaling pathway of hematopoietic stem cells in carbon tetrachloride damaged mouse, and internally elevated the number of HSC and long-term HSC to 2.96-fold and 6.18-fold. In addition, mD1R improved the amplification of the myeloid progenitor cells and the myeloid-derived suppressor cells, particularly the granulocyte/monocyte into blood. Mechanistically, the further analyses suggested that Notch pathway could increase the proliferation of HSC and enhance expression of IL-10 after stress injury.</p><p><b>CONCLUSIONS</b>A new and activated recombinant Notch ligand protein has been obtained successfully to communicate hematopoietic stem cells and hematopoietic microenvironment. The Notch- mediated intrinsic hematopoiesis has been regulated by the anti-inflammatory factor after stress injury.</p>
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Animais , Camundongos , Tetracloreto de Carbono , Escherichia coli , Hematopoese , Células-Tronco Hematopoéticas , Ligantes , Receptores Notch , Transdução de SinaisRESUMO
The long- and short-term outcomes in 21 patients with right colon cancer after right hemicolectomy and multivisceral resection surgery were investigated. Short-term therapeutic effects and long-term survival rate were retrospectively analyzed in patients with right colon cancer. These individuals underwent right hemicolectomy in combination with multivisceral resections including pancreatic head, duodenum, kidney, liver, gallbladder, and abdominal wall at the Department of General Surgery in the Henan Tumor Hospital between January 2003 and August 2014. The patients had an average age of 58.9 years (range: 39-78). Three patients had metastatic invasion only to the duodenum; meanwhile 18 patients had invasion to the duodenum and other adjacent organs. The median survival time was 41 months (95% CI: 6.972-75.028) with one death in the perioperative period. No patients lost follow-up. One-, 3-, and 5-year survival rate was 75%, 56%, and 43%, respectively. It was concluded that indications for surgery should be tightly controlled. Favorable clinical outcomes of right hemicolectomy and multivisceral resection surgery were demonstrated for patients with right colon cancer at the T4 stage.
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Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias do Colo , Cirurgia Geral , Procedimentos Cirúrgicos do Sistema Digestório , MétodosRESUMO
The long- and short-term outcomes in 21 patients with right colon cancer after right hemicolectomy and multivisceral resection surgery were investigated. Short-term therapeutic effects and long-term survival rate were retrospectively analyzed in patients with right colon cancer. These individuals underwent right hemicolectomy in combination with multivisceral resections including pancreatic head, duodenum, kidney, liver, gallbladder, and abdominal wall at the Department of General Surgery in the Henan Tumor Hospital between January 2003 and August 2014. The patients had an average age of 58.9 years (range: 39-78). Three patients had metastatic invasion only to the duodenum; meanwhile 18 patients had invasion to the duodenum and other adjacent organs. The median survival time was 41 months (95% CI: 6.972-75.028) with one death in the perioperative period. No patients lost follow-up. One-, 3-, and 5-year survival rate was 75%, 56%, and 43%, respectively. It was concluded that indications for surgery should be tightly controlled. Favorable clinical outcomes of right hemicolectomy and multivisceral resection surgery were demonstrated for patients with right colon cancer at the T4 stage.
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<p><b>OBJECTIVE</b>To evaluate the amplification rate and the lowestlower detection limit of an in-house HIV-1 Drug resistant (HIVDR) genotyping test.</p><p><b>METHODS</b>A total of 30 plasma samples were selected, which covered all major HIV-1 subtypes predominating prevailing in China (B', CRF07_BC, CRF01 _AE). The viral loads of the 30 selected samples were detected in triplicate by Easy Q method and the average values were taken as the viral loads of the samples. Each sample was diluted to the concentration of > 1000 copies/ml, 401-1000 copies/ml, 101-400 copies/ml, 50-100 copies/ml and < 50 copies/ml with HIV-negative plasma. After extraction of nucleic acids, RT-PCR and nested PCR amplification were performed, the efficiency of amplification of each subtype and the minimum detection limit were determined statistically based on the PCR results.</p><p><b>RESULTS</b>The viral loads of the selected samples ranged from 2.03 x 10(2)-5.92 x 10(4) copies/ml. The sample of 50-1000 copies/ml have a high amplification rate (86%).</p><p><b>CONCLUSION</b>The In-house method for HIV-1 drug resistance genotyping has a high sensitivity with a high successful amplification rate, especially in the samples with low viral load. This method can be used to the detection of drug-resistant virus and to provide scientific data to treatment options for patients.</p>
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China , Farmacorresistência Viral , Genótipo , HIV-1 , Classificação , Genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Carga ViralRESUMO
<p><b>OBJECTIVE</b>Conflicting data have been generated from previous studies to determine which kind of relationship exists between HIV-1 specific CD8 Tcell responses and HIV-1 viral load or CD4 count over the course of infection. In this study, 153 HIV-1 infected LTNPs were enrolled to investigate the role of HIV-1 specific CD8 T-cell responses in chronic HIV-1 infection among HIV-1 infected former blood donors.</p><p><b>METHODS</b>The patients were stratified into three groups according to CD4 count: CD4≥500 cells/μL; 350 cells/μL≤CD4<500 cells/μL; CD4<350 cells/μL. PBMCs were isolated from the patients' anticoagulated blood samples. IL-2 and IFN-γ secretions of CD 8 T cells against 17 HIV-1 consensus B full peptide pools were analyzed by using ICS assay.</p><p><b>RESULTS</b>An overall inverse correlation were observed between CD4 count and plasma viral load. Although no significant difference was observed during the comparisons of frequency/breadth of HIV-1 specific CD8 T cell responses, CD4 count stratification analysis showed that different correlation pattern existed in three strata: as for patients whose CD4 counts were less than 350 cells/μL, no significant correlations were identified between frequency/breadth of HIV-1 specific CD8 T cell responses and CD4 count/viral load; as for patients whose CD4 counts ranged from 350 cells/μL to 500 cells/μL, significant correlation was only observed between the response breadth of IL-2+IFN-γ+ CD8 T cells and CD4 count; however, as for patients whose CD4 counts were more than 500 cells/μL, direct correlations were identified between IL-2+IFN-γ+/IL-2+/IFN-γ+ CD8 T cells and viral load or CD4 count.</p><p><b>CONCLUSIONS</b>Universal consistent inverse correlation was only indentified between CD4 count and viral load. The relationship between HIV-1 specific CD8 T cell responses and CD4 count/viral load varied in different CD4 strata, which showed that better preserved CD4 T cells were correlated with better CD8 T cell functions.</p>
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Adulto , Feminino , Humanos , Masculino , Antígenos Virais , Alergia e Imunologia , Doadores de Sangue , Contagem de Linfócito CD4 , Linfócitos T CD4-Positivos , Biologia Celular , Linfócitos T CD8-Positivos , Biologia Celular , Alergia e Imunologia , China , Epidemiologia , Doença Crônica , Estudos de Coortes , Progressão da Doença , Citometria de Fluxo , Infecções por HIV , Sangue , Epidemiologia , Alergia e Imunologia , Virologia , HIV-1 , Genética , Alergia e Imunologia , Interferon gama , Alergia e Imunologia , Interleucina-2 , Alergia e Imunologia , Ativação Linfocitária , Alergia e Imunologia , Reação em Cadeia da Polimerase , Carga Viral , ViremiaRESUMO
<p><b>OBJECTIVE</b>This study aimed at exploring the feasibility of using dried blood spots (DBS) to detect HIV drug resistance genotyping in China by comparing the results of drug resistance from DBS, plasma and whole blood samples.</p><p><b>METHODS</b>Blood samples were collected from 39 AIDS patients from Anhui (10), Yunnan (13), Hunan (6) and Xinjiang (10) provinces and autonomous regions. The HIV strains that infected these patients covered all the major HIV-1 subtypes prevailing in China (B, CRF01_AE, CRF07_BC). HIV drug resistance genotyping assay was performed on DBS as well as on the whole blood and plasma samples from the same patients simultaneously by using an in-house nest RT-PCR method. Drug resistance levels were determined based on Stanford University HIV drug resistance database, and the results from these three types of samples were compared.</p><p><b>RESULTS</b>The percentages of successful amplification of protease and reverse transcriptase regions in the pol gene were 95% (37/39) from DBS, 92% (36/39) from whole blood and 100% (39/39) from plasma samples. The sequences from the three types of samples showed more than 99% identity.86% (31/36) of the DBS samples had the same set of drug resistance mutations as those which were detected from plasma samples. The differences probably resulted from mixed bases.</p><p><b>CONCLUSIONS</b>There was no major difference in detecting HIV drug resistance genotyping among DBS, plasma and whole blood samples. Therefore, DBS is useful for detection of HIV drug resistance genotyping and is particularly valuable in developing countries like China, especially in remote rural regions.</p>
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Humanos , Teste em Amostras de Sangue Seco , Farmacorresistência Viral , Genética , Estudos de Viabilidade , Genótipo , Infecções por HIV , Sangue , Genética , Virologia , Soropositividade para HIV , Sangue , Genética , Virologia , HIV-1 , Genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Carga ViralRESUMO
<p><b>OBJECTIVE</b>To determine the complementary determining region 3 (CDR3) length diversity of T cell receptor Vbeta repertoires of CD8+ T lymphocytes and to explore its association with viral load in individuals with HIV-1 infection.</p><p><b>METHODS</b>Separation of CD8+ T cells from peripheral blood mononuclear cells (PBMCs) was carried out by using immunomagnetic beads coated with anti-CD8 antibody. Total RNAs from the purified CD8+ T lymphocytes were isolated and used to perform polymerase chain reaction (PCR) amplifications in CDR3 of 22 T cell receptor (TCR) gene families. CDR3 diversity and its association with viral load in individuals with HIV-1 infection were analyzed.</p><p><b>RESULTS</b>An average diversity for all CDR3 profiles in CD8+ T cells from 9 HIV-infected individuals was significantly different as compared to 7 age-matched healthy donors (P<0.05) with the HIV-infected individuals losing diversity in the CDR3 profiles. There was positive correlation between changes in TCR CDR3 diversity and viral load (r=0.771, P<0.05). The changes in CDR3 length diversity of Vbeta families in HIV-infected individuals, particular in Vbeta2, Vbeta4, Vbeta5, Vbeta17, Vbeta20, Vbeta21, Vbeta23, Vbeta24, were statistically different from the healthy controls.</p><p><b>CONCLUSION</b>HIV-1 infection might induce the loss of TCR Vbeta repertoire diversity and disrupt the CDR3 distributions within CD8+ T cells. There should be positive correlation between changes in TCR CDR3 diversity and the viral load in HIV-1 infected patients.</p>
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Humanos , Linfócitos T CD8-Positivos , Alergia e Imunologia , Infecções por HIV , Genética , Virologia , HIV-1 , Alergia e Imunologia , Polimorfismo Genético , Receptores de Antígenos de Linfócitos T , Genética , Carga ViralRESUMO
To investigate the prevalence of drug-resistance mutations, resistance to antiretroviral drugs, and the subsequent virological response to therapy in treatment-naive and antiretroviral-treated patients infected with HIV/AIDS in Henan, China, a total of 431 plasma samples were collected in Queshan county between 2003 and 2004, from patients undergoing the antiretroviral regimen Zidovudine + Didanosine + Nevirapine (Azt+Ddi+Nvp). Personal information was collected by face to face interview. Viral load and genotypic drug resistance were tested. Drug resistance mutation data were obtained by analyzing patient-derived sequences through the HIVdb Program (http://hivdb.stanford.edu). Overall, 38.5% of treatment-naive patients had undetectable plasma viral load (VL), the rate significantly increased to 61.9% in 0 to 6 months treatment patients (mean 3 months) (P<0.005) but again significantly decrease to 38.6% in 6 to 12 months treatment patients (mean 9 months) (P<0.001) and 40.0% in patients receiving more than 12 months treatment (mean 16 months) (P<0.005). The prevalence of drug resistance in patients who had a detectable VL and available sequences were 7.0%, 48.6%, 70.8%, 72.3% in treatment-na(1)ve, 0 to 6 months treatment, 6 to 12 months treatment, and treatment for greater than 12 months patients, respectively. No mutation associated with resistance to Protease inhibitor (PI) was detected in this study. Nucleoside RT inhibitor (NRTI) mutations always emerged after non-nucleoside RT inhibitor (NNRTI) mutations, and were only found in patients treated for more than 6 months, with a frequency less than 5%, with the exception of mutation T215Y (12.8%, 6/47) which occurred in patients treated for more than 12 months. NNRTI mutations emerged quickly after therapy begun, and increased significantly in patients treated for more than 6 months (P<0.005), and the most frequent mutations were K103N, V106A, Y181C, G190A. There had been optimal viral suppression in patients undergoing treatment for less than 6 months in Queshan,Henan. The drug resistance strains were highly prevalent in antiretroviral-treated patients, and increased with the continuation of therapy, with many patients encountering virological failure after 6 months therapy.
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<p><b>OBJECTIVE</b>To investigate subtype and genetic analysis of human immunodeficiency virus type-1 (HIV-1).</p><p><b>METHODS</b>DNA sequences were amplified by nested-PCR from uncultured peripheral blood mononuclear cells (PBMC) obtained from 100 HIV-1 patients from Guangdong Province. The C2 to V3 region of the envelope glycoprotein gp120 of HIV-1 was sequenced directly. The analysis of the gene-based phylogenetic tree and variation of amino acid were carried out by using Wisconsin software package or genetics computer group (GCG).</p><p><b>RESULTS</b>DNA fragments were amplified from 75 PBMC samples by using nested polymerase chain reaction (PCR). Sequence analysis showed that there were 3 HIV-1 subtypes or circulating recombinant forms (CRF): CRF01-AE (n = 44), CRF-BC (n = 27) and B' (n = 4).</p><p><b>CONCLUSIONS</b>Three HIV-1 subtypes or circulating recombinant forms: CRF01-AE, CRF-BC and B' might be circulating in Guangdong Province. Findings from this study suggested that several subtypes might exist in Guangdong Province and the epidemic situation of AIDS be serious. It should be a challenge for Guangdong Province in treating patients, preventing and controlling AIDS in the future.</p>
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Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Síndrome da Imunodeficiência Adquirida , Sangue , Epidemiologia , Virologia , Sequência de Bases , China , Epidemiologia , DNA Viral , HIV-1 , Classificação , Genética , Isoformas de ProteínasRESUMO
<p><b>OBJECTIVE</b>To characterize CRF01_AE strains of recombinant human immunodeficiency virus type-1 (HIV-1) found in the Second National Molecular Epidemiology Study on HIV in China and to analyze its sequence variation in the env V3-C3 region during the First National Molecular Epidemiology Study (NMES1, 1996 - 1998) to the Second National Molecular Epidemiology Study (NMES2, 2001 - 2002).</p><p><b>METHODS</b>DNA was extracted from peripheal blood mononuclear cells of the subjects with HIV infection. The env C2-V4 region of HIV-1 was amplified with nested polymerase chain reaction (n-PCR). PCR products were directly sequenced using ABI 377 DNA sequencer, then the gene-based phylogenetic tree was constructed and its variation of amino acids was analyzed with GCG software.</p><p><b>RESULTS</b>Totally, 169 strains of recombinant HIV-1 CRF01_AE were identified from blood samples collected from different high risk groups in 17 of 31 provinces, municipalities and autonomous regions all over China by the end of 2002. Although sexual transmission still dominated during NMES1 (62.2%, 23/37) and NMES2 (55.3%, 73/132), prevalence of HIV-1 CRF01_AE in intravenous drug users (IDUs) increased to 41.6% (57/137) during NMES2 from 27% (10/37) during NMES1. Phylogenetic tree analysis showed that HIV-1 CRF01_AE strains prevalent in IDUs during NMES2 did not cluster with those prevalent in the subjects infected by sexual transmission during NMES2 and those in IDUs during NMES1. The amino acid residues of V3 region of HIV-1 CRF01_AE in IDUs were relatively conservative, but the sixth, eighth, ninth, tenth, twelfth, fifteenth, sixteenth amino acid residues of C3 region displayed regular changes.</p><p><b>CONCLUSIONS</b>HIV-1 CRF01_AE strain has been introduced into inland provinces from southeastern coast areas and southwestern border areas, with an increasing prevalence in IDUs. The sequence of env V3-C3 region of recombinant HIV-1 CRF01_AE strains prevalent in IDUs during NMES2 was obviously different from that during NMES1, suggesting that HIV-1 CRF01_AE strains prevalent in IDUs during NMES2 might come from a new source and have a potential to spread.</p>
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Humanos , Sequência de Aminoácidos , China , Epidemiologia , Genes env , Genética , Variação Genética , Genoma Viral , Infecções por HIV , Epidemiologia , Genética , Virologia , HIV-1 , Classificação , Genética , Epidemiologia Molecular , Dados de Sequência Molecular , Filogenia , RNA Viral , Genética , Recombinação Genética , Homologia de Sequência de Aminoácidos , Abuso de Substâncias por Via Intravenosa , VirologiaRESUMO
<p><b>OBJECTIVE</b>To collect background information on drug-resistant HIV-1 strains in various regions before the start of nation-wide antiretroviral therapy in China.</p><p><b>METHODS</b>Twenty percent of the 2,000 blood samples from antiretroviral therapy naive patients collected for the 2nd national HIV molecular epidemiology survey (NHMES) in 2002 were randomly sampled for this study. The entire protease gene and 20-230 amino acids of the reverse transcriptase gene were amplified by PCR from provirus DNA and sequenced. The results were analyzed with HIV db-Drug Resistance Algorithm and genotypic resistance mutations were determined to particular anti-HIV drugs.</p><p><b>RESULTS</b>Totally 164 protease gene sequences and 138 reverse transcriptase gene sequences were obtained from patients; 0.61% of 164 sequences displayed primary resistance mutations in the protease gene, whereas 99.39% carried 1 or more secondary mutations. Genotypic resistance to at least one nucleoside reverse transcriptase inhibitors (NRTI) was present in 5.80%,and resistance to at least one non-nucleo side reverse transcriptase inhibitors (NNRTI) was present in 1.45% of samples.</p><p><b>CONCLUSION</b>The prevalence of genotypic drug resistance is very low in drug-naive HIV infected patients from 21 provinces of China tested in this study. Laboratories participated in the NHMES have organized a network to provide drug resistance monitoring service in the current nation-wide antiviral treatment program in China.</p>