Drug resistance is a major problem in the treatment of AIDS, due to the very high mutation rate of human immunodeficiency virus (HIV) and subsequent rapid development of resistance to new drugs. Identification of mutations associated with drug resistance is critical for both individualized treatment selection and new drug design. We have performed an automated mutation analysis of HIV Type 1 (HIV-1) protease and reverse transcriptase (RT) from approximately 40,000 AIDS patient plasma samples sequenced by Specialty Laboratories Inc. from 1999 to mid-2002. This data set provides a nearly complete mutagenesis of HIV protease and enables the calculation of statistically significant K a /K s values for each individual amino acid mutation in protease and RT. Positive selection (i.e., a K a /K s ratio of >1, indicating increased reproductive fitness) detected 19 of 23 known drug-resistant mutation positions in protease and 20 of 34 such positions in RT. We also discovered 163 new amino acid mutations in HIV protease and RT that are strong candidates for drug resistance or fitness. Our results match available independent data on protease mutations associated with specific drug treatments and mutations with positive reproductive fitness, with high statistical significance (the P values for the observed matches to occur by random chance are 10 ؊5.2 and 10 ؊16.6 , respectively). Our mutation analysis provides a valuable resource for AIDS research and will be available to academic researchers upon publication at http://www.bioinformatics.ucla.edu/HIV. Our data indicate that positive selection mapping is an analysis that can yield powerful insights from high-throughput sequencing of rapidly mutating pathogens.The emergence of drug-resistant mutants of human immunodeficiency virus type 1 (HIV-1) protease and reverse transcriptase (RT) genes is an ongoing problem in the fight against AIDS. HIV's mutation rate is high, approximately 4 ϫ 10 Ϫ5 mutations per base per replication cycle, or about one mutation every three generations, yielding at least 10 14 mutations per day worldwide, based on available replication rates and AIDS population estimates (2,12,15). This can lead to the rapid development of resistance to new drug treatments. Researchers and clinicians have made enormous efforts to identify drug-resistant mutations in HIV protease and reverse transcriptase (RT), the molecular targets of the 18 antiretroviral drugs currently approved by the Food and Drug Administration. The discovery of a new drug-resistant mutation typically requires a combination of clinical data (e.g., AIDS patients displaying drug resistance), sequencing, and basic science (e.g., obtaining viral samples and performing phenotypic assays). Fast, automatic methods for identifying drug-resistant mutations could be of great value for researchers studying HIV and other pathogens.Fortunately, the rapid evolution of HIV itself may provide a powerful tool for gaining understanding of its function in general and drug resistance in particular. HIV's high mutati...

Objectives: To investigate fluconazole susceptibility of Candida albicans from non-AIDS patients and to analyse the relationship between mutations in the ERG11 gene of these isolates and fluconazole resistance.Methods: Four hundred and twenty-six clinical isolates of Candida species were collected. Fluconazole susceptibility was tested in vitro using microdilution and disc diffusion assays. The ERG11 genes of 23 isolates of C. albicans (8 susceptible and 15 resistant) and 6 type strains (4 susceptible and 2 resistant) were amplified in three overlapping regions of the gene and sequenced.Results: Of the 426 isolates collected, 68.6% were C. albicans; however, only 5.1% were resistant to fluconazole. Eighteen silent mutations and 19 missense mutations were detected. There were six missense mutations only in resistant isolates or resistant type strains: (i) G487T (A114S) and T916C (Y257H) appeared simultaneously in 14 fluconazole-resistant isolates without any other mutation; these may be associated with resistance; (ii) T541C (Y132H) and T1559C (I471T) are known to contribute to fluconazole resistance; and (iii) C1567A (Q474K) or a novel mutation T1493A (F449Y) was identified but correlations with resistance have not been studied. Conclusions:In this survey, C. albicans is the major cause of candidiasis in non-AIDS patients, and some isolates that are resistant to fluconazole have G487T and T916C mutations in ERG11 that are associated with fluconazole resistance.

The dominant ESBL genotype in Hunan Province was bla(CTX-M). The high prevalence (17.4%) of bla(CTX-M-15) has not previously been reported from China. Our results identify that an epidemic of bla(CTX-M) in Changsha, Hunan Province, has evolved with the appearance and spread of bla(CTX-M-15) against the dominant genotypes bla(CTX-M-14) and bla(CTX-M-3.) The worldwide dominance of bla(CTX-M-15) could be poised to spread to China, displacing the current prevailing genotypes.

A continuous electrospinning technique was applied to fabricate double layer tubular tissue engineering vascular graft (TEVG) scaffold. The luminal layer was made from poly(ɛ-caprolac-tone)(PCL) ultrafine fibers via common single axial electrospinning followed by the outer layer of core-shell structured nanofibers via coaxial electrospinning. For preparing the outer layernano-fibers, the PCL was electrospun into the shell and both bovine serum albumin (BSA) and tetrapeptide val-gal-pro-gly (VAPG) were encapsulated into the core. The core-shell structure in the outer layer fibers was observed by transmission electron microscope (TEM). The in vitro release tests exhibited the sustainable release behavior of BSA and VAPG so that they provided a better cell growth environment in the interior of tubular scaffold wall. The in vitro culture of smooth muscle cells (SMCs) demonstrated their potential to penetrate into the scaffold wall for the 3D cell culture. Subsequently, 3D cell coculture was conducted. First, SMCs were seeded on the luminal surface of the scaffold and cultured for 5 days, and then endothelial cells (ECs) were also seeded on the luminal surface and cocultured with SMCs for another 2 days. After stained with antibodies, 3D cell distribution on the scaffold was revealed by confocal laser scanning microscopy (CLSM) where ECs were mainly located on the luminal surface whereas SMCs penetrated into the surface and distributed inside the scaffold wall. This double layer tubular scaffold with 3D cell distribution showed the promise to develop it into a novel TEVG for clinical trials in the near future.

Abstract. the present study aimed to investigate the potential role of the long non-coding rna (lncrna) Pvt1 oncogene (non-protein coding) (PVt1) in the progression and metastasis of malignant melanoma, and to reveal its possible molecular mechanisms. the expression of lncrna PVt1 in melanoma tissues and adjacent normal skin from patients with melanoma, and in the melanoma a-375 and sk-mel-5 cell lines, was analyzed using reverse transcription-quantitative polymerase chain reaction and western blot analyses. the effects of PVt1 expression on cell proliferation, the cell cycle, cell migration and cell invasion were analyzed using MTT assay, flow cytometry, Transwell and scratch assays, respectively. the interaction between PVt1 and enhancer of zeste homolog 2 (eZH2) in melanoma cells was analyzed using rna immunoprecipitation (riP) assay. the effect of PVt1 on microrna-200c (mir-200c) expression was analyzed by chromatin immunoprecipitation (chiP) assay. PVt1 was highly expressed in the melanoma tissues and cells. Silencing of PVT1 significantly inhibited cell proliferation, migration and invasion, and arrested the cell cycle at the G0/G1 stage. Additionally, PVT1 silencing significantly decreased the cyclin d1 expression in the melanoma cells. The expression of E-cadherin was significantly increased and the expression of N-cadherin and vimentin was significantly decreased in the PVt1-silenced group. the riP assay found that endogenous PVt1 was highly enriched by eZH2 riP compared with that of the negative control. the chiP assay revealed that the expression of miR-200c was decreased significantly in the PVt1-silenced group compared with the controls.overall, the present study demonstrated that the lncrna PVt1 may contribute to the tumorigenesis and metastasis of melanoma through binding to eZH2 and regulating the expression of mir-200c. lncrna PVt1 may serve as a potential target for the therapy of melanoma.