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1.
J Med Educ Curric Dev ; 10: 23821205231175034, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37187918

RESUMO

OBJECTIVES: To improve 4 skills (communication, history-taking, past history-taking, and documentation) in medical students, we designed and pilot-tested a curriculum to teach a sample of Year 4 (Y4) students these skills and compared the clinical performance of these students with students not receiving the intervention. METHODS: The study focused on the new curriculum's effectiveness in enhancing students' performance of these skills. To minimize exposure across groups, participants were divided into intervention and control groups at random and placed in various classrooms. We evaluated each group's clinical competency 3 times: prior to the intervention, 9 weeks afterward, and 2 years later. RESULTS: There was no difference at baseline between the 2 groups. Immediately following the intervention, the mean score of the intervention group's skills was significantly higher than before and higher than the control group in each clinical skill. The performance difference between the 2 groups was maintained for 2 years following the intervention. CONCLUSIONS: Following a 9-week curriculum, evaluators rated students' performance higher than their counterparts who learned these skills through standard informal exposure in the clinical setting. The fact that this performance advantage was maintained for 2 years following the intervention is a testament to the durability of the intervention and the value of dedicated training in these critical areas at an early point in students' clinical careers.

2.
Antimicrob Agents Chemother ; 67(5): e0138622, 2023 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-37071019

RESUMO

Human immunodeficiency virus (HIV) treatment with antiretroviral regimens containing integrase strand transfer inhibitors such as dolutegravir (DTG) and bictegravir (BIC) offers high levels of protection against the development of drug resistance mutations. Despite this, resistance to DTG and BIC can occur through the development of the R263K integrase substitution. Failure with DTG has also been associated with the emergence of the G118R substitution. G118R and R263K are usually found separately but have been reported together in highly treatment-experienced persons who experienced treatment failure with DTG. We used cell-free strand transfer and DNA binding assays and cell-based infectivity, replicative capacity, and resistance assays to characterize the G118R plus R263K combination of integrase mutations. R263K reduced DTG and BIC susceptibility ~2-fold, in agreement with our previous work. Single-cycle infectivity assays showed that G118R and G118R plus R263K conferred ~10-fold resistance to DTG. G118R alone conferred low levels of resistance to BIC (3.9-fold). However, the G118R plus R263K combination conferred high levels of resistance to BIC (33.7-fold), likely precluding the use of BIC after DTG failure with the G118R plus R263K combination. DNA binding, viral infectivity, and replicative capacity of the double mutant were further impaired, compared to single mutants. We propose that impaired fitness helps to explain the scarcity of the G118R plus R263K combination of integrase substitutions in clinical settings and that immunodeficiency likely contributes to its development.


Assuntos
Infecções por HIV , Inibidores de Integrase de HIV , Integrase de HIV , HIV-1 , Humanos , Inibidores de Integrase de HIV/farmacologia , Inibidores de Integrase de HIV/uso terapêutico , HIV-1/genética , HIV-1/metabolismo , Substituição de Aminoácidos , Integrase de HIV/genética , Integrase de HIV/metabolismo , Mutação , Compostos Heterocíclicos com 3 Anéis/farmacologia , Compostos Heterocíclicos com 3 Anéis/uso terapêutico , Piridonas/farmacologia , DNA/farmacologia , DNA/uso terapêutico , Farmacorresistência Viral/genética , Infecções por HIV/tratamento farmacológico
3.
Sci Total Environ ; 857(Pt 2): 159490, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36257413

RESUMO

The water environment of a river network can self-clean to a certain extent; however, when the wastewater discharge load exceeds a certain threshold, the balance of nature is disrupted, leading to water pollution. This emphasises the urgent need to evaluate river water environmental capacity (RWEC) as a necessary parameter for sustainable development. However, to quantify the RWEC, it is important to estimate the hydrological and hydrodynamic factors in the basin, leading to the linking of these models. The present investigation aims to propose an integrated framework, named RWEC, consisting of hydrological and hydrodynamic models, a database system, and GIS to evaluate the water environmental carrying capacity of the selected river network. The rain - runoff (RR), hydrodynamic (HD), ecological (ECO), and RWEC models were used. Groups of data, including meteorology, hydrology, and the environment, combined with topographic data and waste sources, were applied. Groups of models and data were integrated into a seven-step framework to calculate the RWEC. The case study is a basin in Binh Duong Province, Vietnam and four pollutants were selected: NH4+, BOD5, NO3-, PO43-. The flow and water quality factors in the river basin in the study area were measured based on hydraulic models, and the water quality was calibrated. The role of hydrological, hydraulic, and water quality models in the RWEC calculation was clarified. According to the baseline and forecast scenarios, the calculation of the RWEC for the scenarios was performed. In the baseline scenario, RWECNH4+ is in the range (-283, -22) kg/day, RWECBOD5 ranges from (143, 3126) kg/day, RWECNO3- is in the range (-778, 2166) kg/day, and RWECPO43- is in the range (-31, 46) kg/day. The dependence of RWEC on environmental factors, self-cleaning factors, and the difference between the baseline and forecast scenarios were clarified.


Assuntos
Hidrologia , Qualidade da Água , Rios , Chuva , Modelos Teóricos , Monitoramento Ambiental
4.
J Glob Antimicrob Resist ; 31: 323-327, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36347497

RESUMO

OBJECTIVES: We report a case of incomplete HIV-1 suppression on a dolutegravir, lamivudine, and abacavir single-tablet regimen with the emergence of the H51Y and G118R integrase resistance mutations. METHODS: Integrase sequencing was performed retrospectively by Sanger and next-generation sequencing. Rates of emergence and decline of resistance mutations were calculated using next-generation sequencing data. Dolutegravir plasma concentrations were measured by ultra-performance liquid chromatography-tandem mass spectrometry. The effects of H51Y and G118R on infectivity, fitness, and susceptibility to dolutegravir were quantified using cell-based assays. RESULTS: During periods of non-adherence to treatment, mutations were retrospectively documented only by next-generation sequencing. Misdiagnosis by Sanger sequencing was caused by the rapid decline of mutant strains within the retroviral population. This observation was also true for a M184V lamivudine-resistant reverse transcriptase mutation found in association with integrase mutations on single HIV genomes. Resistance rebound upon treatment re-initiation was swift (>8000 copies per day). Next-generation sequencing indicated cumulative adherence to treatment. Compared to WT HIV-1, relative infectivity was 73%, 38%, and 43%; relative fitness was 100%, 35%, and 10% for H51Y, G118R, and H51Y+G118R viruses, respectively. H51Y did not change the susceptibility to dolutegravir, but G188R and H51Y+G118R conferred 7- and 28-fold resistance, respectively. CONCLUSION: This case illustrates how poorly-fit drug-resistant viruses wax and wane alongside erratic treatment adherence and are easily misdiagnosed by Sanger sequencing. We recommend next-generation sequencing to improve the clinical management of incomplete virological suppression with dolutegravir.


Assuntos
Integrase de HIV , HIV-1 , Humanos , HIV-1/genética , Integrase de HIV/genética , Lamivudina/farmacologia , Lamivudina/uso terapêutico , Farmacorresistência Viral/genética , Estudos Retrospectivos , Cooperação e Adesão ao Tratamento
5.
Diagnostics (Basel) ; 10(7)2020 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-32708399

RESUMO

We investigated Nucleos(t)ide-analogue (NA)-resistance mutations (mt) in 142 treatment-naive children with Chronic Hepatitis B (CHB), using a sensitive co-amplification at lower denaturation temperature (COLD)-PCR with Sanger DNA sequencing. An NA resistance-associated mt in the hepatitis B virus (HBV) reverse transcriptase (RT) was found in 66.2% of the patients, with nonclassical mt contributing the most (64.8%). Significantly higher frequencies of Lamivudine (LMV) and Adefovir dipivoxil (ADF) resistance-associated mt were found in genotypes B and C, respectively (ORLMV/ADF: 1495.000; 95% CI: 89.800-24,889.032; p < 0.001). Single-point mt associated to LMV and ADF resistance were detected in 59.9% of the tested children with rtV207M (38.0%) and rtN238T (9.9%) being the most frequent. Multiple-point mt were found only in 8 cases (5.6%): 6 children carried double mt (rtV207M + rtL229V; rtV207M + rtI233V; rtV207I + rtV207M × 2 cases; rtV207M + rtS213T; rtN238A + rtS256G) relating to LMV or/and ADF resistance and 3 children carried triple mt (rtL180M + rtM204I + rtN238T; rtV207M + rtS213T + rtS256G) or quadruple mt (rtL180M + rtM204V + rtV207I/M) for LMV-ADF resistance and Entecavir-reduced susceptibility. Our data indicate that significantly higher frequencies of LMV and ADF-associated mutations were found in treatment-naïve children infected with HBV genotypes B and C, respectively. The developed COLD-PCR method and obtained data may contribute to the development of suitable treatments for children with CHB.

6.
Artigo em Inglês | MEDLINE | ID: mdl-32180823

RESUMO

As part of a combined antiretroviral regimen, doravirine is safe and effective at suppressing viral replication in both treatment-naive and treatment-experienced adults living with human immunodeficiency virus (HIV)-1 who have no history of drug resistance against doravirine. In virologically suppressed individuals switching to a combination of doravirine, lamivudine, and tenofovir disoproxil fumarate, no resistance was found after 48 weeks. In treatment-naive individuals, rare cases (<2%) of emergent drug resistance have been reported, often involving the development of substitutions at position V106. From these few clinical cases, it is inferred that cross-resistance with other non-nucleoside reverse transcriptase inhibitors (NNRTIs) should be limited. In contrast, the use of doravirine as a second NNRTI should be evaluated on a case-by-case basis in the presence of pre-existing resistance. Importantly, doravirine remains active against K103N viruses in vitro, and limited clinical evidence suggests this to be the case in patients as well. Since K103N is by far the most prevalent (<70%) NNRTI substitution found in clinical practice, resistance against doravirine-based antiretroviral therapies is expected to be rare, even for treatment-experienced individuals. This review summarizes chemical, pharmacological, and clinical information about doravirine with an emphasis on drug resistance. The efficacy results from an early phase clinical trial evaluating doravirine in combination with islatravir are also provided.

7.
Expert Opin Investig Drugs ; 29(3): 273-283, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31994943

RESUMO

Introduction: HIV infection is manageable through the use of antiretroviral drugs. However, HIV reservoirs that are constituted early during infection are resistant to treatment. HIV persistence under treatment necessitates life-long treatment and is associated with various co-morbidities. Two significant research avenues are explored through the development of either new antiretroviral drugs or interventions aimed at stimulating the immune system to eradicate HIV reservoirs.Areas covered: This report provides a review of investigational drugs and cell-based interventions against HIV infection that are currently under Phase I or Phase II clinical trials. We report on new antiretroviral drugs, antibodies directed against viral or host targets, reactivating agents, immune modulators and immune checkpoint inhibitors, and cell-based interventions. These new therapies are often tested in combination, including with current antiretroviral drugs.Expert opinion: Islatravir and GS-6207 are promising antiretroviral drugs that are expected to perform well in phase III trials. Whether the host immune system can be activated sufficiently to reduce HIV reservoirs remains unknown. Additional research is needed to identify surrogate markers of success for curative interventions. Given the current safety and efficacy of antiretroviral treatment, risk-benefits should be carefully evaluated before interventions that risk triggering high levels of immune stimulation.


Assuntos
Fármacos Anti-HIV/administração & dosagem , Infecções por HIV/tratamento farmacológico , HIV-1/efeitos dos fármacos , Fármacos Anti-HIV/farmacologia , Ensaios Clínicos Fase I como Assunto , Ensaios Clínicos Fase II como Assunto , Desenvolvimento de Medicamentos , Farmacorresistência Viral , Quimioterapia Combinada , Drogas em Investigação/administração & dosagem , Drogas em Investigação/farmacologia , Infecções por HIV/virologia , HIV-1/isolamento & purificação , Humanos
8.
Cerebrovasc Dis Extra ; 9(2): 77-89, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31408859

RESUMO

BACKGROUND: Intraventricular haemorrhage (IVH) patients with acute obstructive hydrocephalus (AOH) who require external ventricular drainage (EVD) are at high risk for poor outcomes. Intraventricular fibrinolysis (IVF) with low-dose recombinant tissue plasminogen activator (rtPA) can be used to improve patient outcomes. Here, we evaluated the impact of IVF on the risk of death and the functional outcomes in IVH patients with AOH. METHODS: This prospective cohort study included IVH patients with hypertensive intracranial haemorrhage complicated by AOH who required EVD. We evaluated the risk of death and the functional outcomes at 1 and 3 months, with a specific focus on the impact of combined EVD with IVF by low-dose rtPA. RESULTS: Between November 30, 2011 and December 30, 2014, 80 patients were included. Forty-five patients were treated with EVD alone (EVD group) and 35 received IVF (EVD+IVF group). The 30- and 90-day mortality rates were lower in the EVD+IVF group than in the EVD group (42.2 vs. 11.4%, p = 0.003, and 62.2 vs. 20%, p < 0.001, respectively). The Graeb scores were significantly lower in the EVD+IVF group than in the EVD group (p ≤ 0.001) during the first 3 days and on day 7 after assignment. The 30-day good functional outcome (modified Rankin Scale [mRS] score 0-3) was also higher in the EVD+IVF group than in the EVD group (6.7 vs. 28.6%, p = 0.008). However, the 90-day good functional outcome (mRS score 0-3) did not significantly increase in the EVD+IVF group (30.8% in the EVD group vs. 51.6% in the EVD+IVF group, p = 0.112). CONCLUSIONS: In our prospective observational study, EVD+IVF was associated with a lower risk of death in IVH patients. EVD+IVF improved the chance of having a good functional outcome at 1 month; however, this result was no longer observed at 3 months.


Assuntos
Hemorragia Cerebral Intraventricular/terapia , Drenagem/métodos , Fibrinolíticos/administração & dosagem , Hidrocefalia/terapia , Terapia Trombolítica/métodos , Ativador de Plasminogênio Tecidual/administração & dosagem , Doença Aguda , Adulto , Idoso , Hemorragia Cerebral Intraventricular/diagnóstico por imagem , Hemorragia Cerebral Intraventricular/mortalidade , Hemorragia Cerebral Intraventricular/fisiopatologia , Terapia Combinada , Drenagem/efeitos adversos , Drenagem/mortalidade , Feminino , Fibrinolíticos/efeitos adversos , Humanos , Hidrocefalia/diagnóstico por imagem , Hidrocefalia/mortalidade , Hidrocefalia/fisiopatologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Recuperação de Função Fisiológica , Medição de Risco , Fatores de Risco , Terapia Trombolítica/efeitos adversos , Terapia Trombolítica/mortalidade , Fatores de Tempo , Ativador de Plasminogênio Tecidual/efeitos adversos , Resultado do Tratamento
10.
Expert Opin Pharmacother ; 20(4): 385-397, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30698467

RESUMO

INTRODUCTION: Current antiretroviral therapy is more effective and simpler than in previous times due to the development of new drugs with improved pharmacokinetic and pharmacodynamic profiles and the advent of single pill regimens with low toxicity that facilitate long-term adherence. The recent approval of the novel potent integrase strand-transfer inhibitor bictegravir (BIC) co-formulated with emtricitabine (FTC) and tenofovir alafenamide (TAF) in a fixed daily dose pill, B/F/TAF, adds to the list of single-tablet regimens available to treat HIV infection. Areas covered: This review provides an overview of the pharmacological and clinical information obtained from MEDLINE/PubMed publications and the latest international conferences. Expert opinion: BIC is a potent antiretroviral with an improved resistance profile over previous integrase inhibitors. Its combination with the new tenofovir prodrug TAF and FTC creates an effective regimen B/F/TAF for treatment-naïve patients and for those switching from another successful combination. B/F/TAF's favorable pharmacokinetic profile, simple dose, low pill burden, and few drug-drug interactions or treatment-related adverse events, will make it one of the preferred regimens in the future.


Assuntos
Fármacos Anti-HIV/administração & dosagem , Infecções por HIV/tratamento farmacológico , Adenina/administração & dosagem , Adenina/análogos & derivados , Alanina , Amidas , Animais , Fármacos Anti-HIV/uso terapêutico , Combinação de Medicamentos , Interações Medicamentosas , Emtricitabina/administração & dosagem , Emtricitabina/uso terapêutico , Compostos Heterocíclicos com 3 Anéis , Compostos Heterocíclicos de 4 ou mais Anéis/administração & dosagem , Humanos , Piperazinas , Piridonas , Comprimidos , Tenofovir/análogos & derivados
11.
J Virol ; 93(2)2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30381490

RESUMO

Drug resistance remains a major concern for human immunodeficiency virus (HIV) treatment. To date, very few resistance mutations have emerged in first-line combination therapy that includes the integrase strand transfer inhibitor (INSTI) dolutegravir (DTG). In vitro, DTG selects for several primary mutations that induce low-level DTG resistance; secondary mutations, while increasing the level of resistance, however, further impair replication fitness, which raised the idea that DTG monotherapy may be feasible. The simian immunodeficiency virus (SIV) rhesus macaque model of HIV infection can be useful to explore this concept. Nine macaques were infected with virulent SIVmac251 and started on DTG monotherapy during either acute (n = 2) or chronic infection (n = 7). Within 4 weeks of treatment, all animals demonstrated a reduction in viremia of 0.8 to 3.5 log RNA copies/ml plasma. Continued treatment led to overall sustained benefits, but the outcome after 10 to 50 weeks of treatment was highly variable and ranged from viral rebound to near pretreatment levels to sustained suppression, with viremia being 0.5 to 5 logs lower than expected based on pretreatment viremia. A variety of mutations previously described to confer low-level resistance of HIV-1 to DTG or other INSTI were detected, and these were sometimes followed by mutations believed to be compensatory. Some mutations, such as G118R, previously shown to severely impair the replication capacity in vitro, were associated with more sustained virological and immunological benefits of continued DTG therapy, while other mutations, such as E92Q and G140A/Q148K, were associated with more variable outcomes. The observed variability of the outcomes in macaques warrants avoidance of DTG monotherapy in HIV-infected people.IMPORTANCE A growing number of anti-HIV drug combinations are effective in suppressing virus replication in HIV-infected persons. However, to reduce their cost and risk for toxicity, there is considerable interest in simplifying drug regimens. A major concern with single-drug regimens is the emergence of drug-resistant viral mutants. It has been speculated that DTG monotherapy may be a feasible option, because DTG may have a higher genetic barrier for the development of drug resistance than other commonly used antiretrovirals. To explore treatment initiation with DTG monotherapy, we started SIV-infected macaques on DTG during either acute or chronic infection. Although DTG initially reduced virus replication, continued treatment led to the emergence of a variety of viral mutations previously described to confer low-level resistance of HIV-1 to DTG, and this was associated with variable clinical outcomes. This unpredictability of mutational pathways and outcomes warns against using DTG monotherapy as initial treatment for HIV-infected people.


Assuntos
Inibidores de Integrase de HIV/administração & dosagem , Compostos Heterocíclicos com 3 Anéis/administração & dosagem , Síndrome de Imunodeficiência Adquirida dos Símios/tratamento farmacológico , Vírus da Imunodeficiência Símia/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Farmacorresistência Viral , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , Inibidores de Integrase de HIV/farmacologia , Compostos Heterocíclicos com 3 Anéis/farmacologia , Humanos , Macaca mulatta , Mutação , Oxazinas , Piperazinas , Piridonas , RNA Viral/sangue , RNA Viral/efeitos dos fármacos , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/patogenicidade , Resultado do Tratamento
14.
Drugs Context ; 7: 212522, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29497452

RESUMO

Human immunodeficiency virus type 1 (HIV-1) infection remains a major health issue worldwide. In developed countries, antiretroviral therapy has extended its reach from treatment of people living with HIV-1 to post-exposure prophylaxis, treatment as prevention, and, more recently, pre-exposure prophylaxis. These healthcare strategies offer the epidemiological tools to curve the epidemic in rich settings and will be concomitantly implemented in developing countries. One of the remaining challenges is to identify an efficacious curative strategy. This review manuscript will focus on some of the current curative strategies aiming at providing a sterilizing or functional cure to HIV-1-positive individuals. These include the following: early treatment initiation in post-treatment controllers as a long-term HIV-1 remission strategy, latency reversal, gene editing with or without stem cell transplantation, and antibodies against either the viral envelope protein or the host integrin α4ß7.

15.
mBio ; 8(2)2017 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-28377526

RESUMO

Human immunodeficiency virus (HIV) infection persists despite decades of active antiretroviral therapy (ART), effectively preventing viral eradication. Treatment decreases plasma viral RNA, but viral DNA persists, mostly integrated within the genome of nucleated blood cells. Viral DNA blood levels correlate with comorbidities and the rapidity of viral rebound following treatment interruption. To date, no intervention aiming at decreasing HIV DNA levels below those attained through ART has been successful. This includes use of some integrase inhibitors either as part of ART or in treatment intensification studies. We have argued that using the integrase inhibitor dolutegravir (DTG) in similar studies may yield better results, but this remains to be studied. In treatment-experienced individuals, the most frequent substitution associated with failure with dolutegravir is R263K in integrase. R263K decreases integration both in cell-free and tissue culture assays. We investigated here how integrated DNA levels evolve over time during prolonged infections with R263K viruses. To investigate a potential defect in reverse transcription with R263K, the levels of reverse transcripts were measured by quantitative PCR. We measured HIV type 1 (HIV-1) integration in Jurkat cells over the course of 4-week infections using Alu-mediated quantitative PCR. The results show that R263K did not decrease reverse transcription. Prolonged infections with R263K mutant viruses led to less HIV-1 integrated DNA over time compared to wild-type viruses. These tissue culture results help to explain the absence of the R263K substitution in most individuals experiencing failure with DTG and support studies aiming at longitudinally measuring the levels of integrated DNA in individuals treated with this drug.IMPORTANCE Antiretroviral treatment decreases plasma viral RNA, but HIV DNA persists for decades within infected cells. Studies of nonhuman primates have suggested that reducing retroviral DNA levels might represent a path to eradication. The integrase inhibitor dolutegravir is less susceptible than any other anti-HIV drug to the emergence of resistance in treatment-naive individuals. In treatment-experienced individuals, in contrast, rare cases of treatment failure were commonly associated with emergence of an R263K integrase substitution that confers low-level resistance to dolutegravir. It is unclear why this substitution is not more common in individuals experiencing failure with dolutegravir. We report here that R263K progressively diminishes the levels of integrated HIV-1 DNA in tissue culture over multiple cycles of infection. Our results help to explain aspects of the clinical efficacy of dolutegravir and suggest that this drug may be able to reduce HIV DNA levels within infected individuals compared to other drugs.


Assuntos
Farmacorresistência Viral , Inibidores de Integrase de HIV/farmacologia , Integrase de HIV/metabolismo , HIV-1/fisiologia , Compostos Heterocíclicos com 3 Anéis/farmacologia , Mutação de Sentido Incorreto , Integração Viral , DNA Viral/análise , Células HEK293 , Integrase de HIV/genética , HIV-1/enzimologia , Humanos , Células Jurkat , Oxazinas , Piperazinas , Piridonas , Reação em Cadeia da Polimerase em Tempo Real
16.
AIDS ; 30(15): 2267-73, 2016 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-27367488

RESUMO

OBJECTIVE: Recommended treatments for newly diagnosed HIV-positive individuals now focus on the integrase strand transfer inhibitors, raltegravir (RAL), elvitegravir (EVG) and dolutegravir (DTG). In treatment-naive individuals, cases of RAL-based and EVG-based virological failure, although rare, are associated with the occurrence of resistance mutations in integrase and/or reverse transcriptase coding sequences. In such cases, common resistance substitutions in reverse transcriptase that were associated with nucleos(t)ide reverse transcriptase inhibitors included M184I/V and K65R and these occurred together with various mutations in integrase. In some instances, these mutations in reverse transcriptase preceded the emergence of mutations in integrase. In contrast, no resistance substitutions in either integrase or reverse transcriptase have been observed to date in viruses isolated from treatment-naive individuals who experienced treatment failure with DTG-based regimens. DESIGN: The objective of this study was to determine the effects of the M184I/V and K65R substitutions in reverse transcriptase on the ability of HIV-1 to become resistant against RAL, EVG or DTG. METHODS: We performed tissue culture selection experiments using reverse transcriptase inhibitor-resistant viruses containing resistance substitutions at positions K65R, M184I or M184V in the presence of increasing concentrations of RAL, EVG or DTG and monitored changes in integrase sequences by genotyping. RESULTS: Selections using EVG and RAL led to the emergence of resistance mutations in integrase. In contrast, only the wild-type virus was able to acquire resistance mutations for DTG. CONCLUSION: Resistance mutations against nucleos(t)ide reverse transcriptase inhibitors antagonized the development of HIV-1 resistance against DTG but not RAL or EVG.


Assuntos
Farmacorresistência Viral , Inibidores de Integrase de HIV/farmacologia , Integrase de HIV/genética , Transcriptase Reversa do HIV/genética , HIV-1/efeitos dos fármacos , Compostos Heterocíclicos com 3 Anéis/farmacologia , Mutação de Sentido Incorreto , Técnicas de Genotipagem , HIV-1/enzimologia , HIV-1/genética , Humanos , Oxazinas , Piperazinas , Piridonas , Seleção Genética , Cultura de Vírus
17.
Int J Plant Genomics ; 2015: 892716, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26167172

RESUMO

Cotton exhibits moderately high vegetative tolerance to water-deficit stress but lint production is restricted by the available rainfed and irrigation capacity. We have described the impact of water-deficit stress on the genetic and metabolic control of fiber quality and production. Here we examine the association of tentative consensus sequences (TCs) derived from various cotton tissues under irrigated and water-limited conditions with stress-responsive QTLs. Three thousand sixteen mapped sequence-tagged-sites were used as anchored targets to examine sequence homology with 15,784 TCs to test the hypothesis that putative stress-responsive genes will map within QTLs associated with stress-related phenotypic variation more frequently than with other genomic regions not associated with these QTLs. Approximately 1,906 of 15,784 TCs were mapped to the consensus map. About 35% of the annotated TCs that mapped within QTL regions were genes involved in an abiotic stress response. By comparison, only 14.5% of the annotated TCs mapped outside these QTLs were classified as abiotic stress genes. A simple binomial probability calculation of this degree of bias being observed if QTL and non-QTL regions are equally likely to contain stress genes was P (x ≥ 85) = 7.99 × 10(-15). These results suggest that the QTL regions have a higher propensity to contain stress genes.

18.
J Virol ; 85(19): 10069-78, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21775445

RESUMO

The Acheta domesticus densovirus (AdDNV), isolated from crickets, has been endemic in Europe for at least 35 years. Severe epizootics have also been observed in American commercial rearings since 2009 and 2010. The AdDNV genome was cloned and sequenced for this study. The transcription map showed that splicing occurred in both the nonstructural (NS) and capsid protein (VP) multicistronic RNAs. The splicing pattern of NS mRNA predicted 3 nonstructural proteins (NS1 [576 codons], NS2 [286 codons], and NS3 [213 codons]). The VP gene cassette contained two VP open reading frames (ORFs), of 597 (ORF-A) and 268 (ORF-B) codons. The VP2 sequence was shown by N-terminal Edman degradation and mass spectrometry to correspond with ORF-A. Mass spectrometry, sequencing, and Western blotting of baculovirus-expressed VPs versus native structural proteins demonstrated that the VP1 structural protein was generated by joining ORF-A and -B via splicing (splice II), eliminating the N terminus of VP2. This splice resulted in a nested set of VP1 (816 codons), VP3 (467 codons), and VP4 (429 codons) structural proteins. In contrast, the two splices within ORF-B (Ia and Ib) removed the donor site of intron II and resulted in VP2, VP3, and VP4 expression. ORF-B may also code for several nonstructural proteins, of 268, 233, and 158 codons. The small ORF-B contains the coding sequence for a phospholipase A2 motif found in VP1, which was shown previously to be critical for cellular uptake of the virus. These splicing features are unique among parvoviruses and define a new genus of ambisense densoviruses.


Assuntos
Densovirus/genética , Densovirus/isolamento & purificação , Regulação Viral da Expressão Gênica , Genoma Viral , Gryllidae/virologia , Animais , Baculoviridae , Western Blotting , Clonagem Molecular , DNA Viral/química , DNA Viral/genética , Europa (Continente) , Perfilação da Expressão Gênica , Vetores Genéticos , Espectrometria de Massas , Dados de Sequência Molecular , Splicing de RNA , Análise de Sequência de DNA , Proteínas Virais/genética
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