RESUMO
BACKGROUND: Inefficient clinical workflows can have downstream effects of increased costs, poor resource utilization, and worse patient outcomes. The surgical consultation process can be complex with unclear communication, potentially delaying care for patients requiring time-sensitive intervention in an acute setting. A novel electronic health records (EHR)-based workflow was implemented to improve the consultation process. After implementation, we assessed the impact of this initiative in patients requiring vascular surgery consultation. METHODS: An EHR-driven consultation workflow was implemented at a single institution, standardizing the process across all consulting services. This order-initiated workflow automated notification to clinicians of consult requests, communication of patient data, patient addition to consultants' lists, and tracking consult completion. Preimplementation (1/1/2020-1/31/2022) and postimplementation (2/1/2022-12/4/2022) vascular surgery consultation cohorts were compared to evaluate the impact of this initiative on timeliness of care. RESULTS: There were 554 inpatient vascular surgery consultations (255 preimplementation and 299 postimplementation); 45 and 76 consults required surgery before and after implementation, respectively. The novel workflow resulted in placement of a consult note 32 min faster than preimplementation (preimplementation: 462 min, postimplementation: 430 min, P = 0.001) for all vascular surgery consults. Furthermore, vascular surgery patients with ASA class III or IV status requiring an urgent or emergent operation were transported to the operating room 63.3% faster after implementation of the workflow (preimplementation: 284 min, postimplementation: 180 min, P = 0.02). There were no differences in procedure duration, postoperative disposition, or intraoperative complication rates. CONCLUSIONS: We implemented a novel workflow utilizing the EHR to standardize and automate the consultation process in the acute inpatient setting. This institutional initiative significantly improved timeliness of care for vascular surgery patients, including decreased time to operation. Innovations such as this can be further disseminated across shared EHR platforms across institutions, representing a powerful tool to increase the value of care in vascular surgery and healthcare overall.
Assuntos
Registros Eletrônicos de Saúde , Salas Cirúrgicas , Humanos , Fluxo de Trabalho , Resultado do Tratamento , Encaminhamento e Consulta , Procedimentos Cirúrgicos Vasculares/efeitos adversosRESUMO
Lung transplantation survival estimates are traditionally reported as fixed 1-, 5-, and 10-year mortality rates. Alternatively, this study aims to demonstrate how conditional survival models can provide useful prognostic information tailored to the time a recipient has already survived from the date of transplantation. Recipient data was obtained from the Organ Procurement and Transplantation Network database. Data from 24,820 adult recipients over age 18 who received a lung transplant between 2002 and 2017 were included in the study. Five-year observed conditional survival estimates were calculated by recipient age, sex, race, transplant indication, transplant type ( i.e. , single or double), and renal function at the time of transplantation. Significant variability exists in conditional survival following lung transplantation. Each specific recipient characteristic significantly impacted conditional survival during at least one time point in the first 5 years. Younger age and double lung transplantation were the two most positive predictors of improved conditional survival consistently throughout the 5-year study period. Conditional survival in lung transplantation recipients changes over time and across recipient characteristics. Hazards of mortality are not fixed and need to be dynamically evaluated as a function of time. Conditional survival calculations can provide more accurate prognostic predictions than unconditional survival estimates.
Assuntos
Transplante de Coração , Transplante de Pulmão , Obtenção de Tecidos e Órgãos , Adulto , Humanos , Adolescente , Sobrevivência de Enxerto , Transplante de Pulmão/efeitos adversos , Transplantados , Taxa de Sobrevida , Estudos Retrospectivos , Doadores de TecidosRESUMO
BACKGROUND: Lung transplantation is the mainstay of treatment for patients with end-stage respiratory failure. This study sought to evaluate survival following transplantation compared to the general population and quantify standardized mortality ratios (SMRs) using a nested case-control study design. METHODS: Control subjects were nonhospitalized inhabitants of the United States identified through the National Longitudinal Mortality Study. Case subjects were adults who underwent lung transplantation between 1990 and 2007 and identified through the Organ Procurement and Transplantation Network. Propensity-matching (5:1, nearest neighbor, caliper = 0.1) was utilized to identify suitable control subjects based on age, sex, race, and location of residency. The primary study endpoint was 10-year survival. RESULTS: About 14,977 lung transplant recipients were matched to 74,885 nonhospitalized US residents. The 10-year survival rate of lung transplant recipients was 28% (95% confidence interval [CI] = 27%-29%). The population expected mortality rate was 19 deaths/100 person-years while the observed ratio was 104 deaths/100 person-years (SMR = 5.39, 95% CI = 5.35-5.43). The largest discrepancies between observed and expected mortality rates were in females (SMR = 5.97), Hispanic (SMR = 10.70), and single lung recipients (SMR = 5.92). SMRs declined over time (1990-1995 = 5.79, 1996-2000 = 5.64, and 2001-2007 = 5.10). Standardized mortality peaks in the first year after transplant and decreases steadily over time. CONCLUSIONS: Lung transplant recipients experience a fivefold higher SMR compared to the nonhospitalized population. Long-term mortality rates have experienced consistent decline over time.
Assuntos
Transplante de Pulmão , Obtenção de Tecidos e Órgãos , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Taxa de Sobrevida , Transplantados , Estados Unidos/epidemiologiaRESUMO
BACKGROUND: the incidence of organ donation after circulatory death (DCD) is increasing; however, heart use has lagged behind other solid organs. Ex vivo perfusion devices are under United States Food and Drug Administration review for use in DCD heart recovery. This study sought to measure the potential increase in the donor pool if DCD heart donation becomes widely adopted. METHODS: DCD donor data were obtained from Organ Procurement and Transplantation Network database. Selection criteria included donor age 18 to 49 years, donors meeting Maastricht III criteria, warm ischemia time ≤30 minutes, and donation between 2015 and 2020. Exclusion criteria were coronary disease, prior myocardial infarction, ejection fraction <0.50, significant valve disease, bacteremia, pulmonary capillary wedge pressure >15 mm Hg, and history of HIV/hepatitis C virus infections. RESULTS: There were 12 813 DCD donors during this period, of which 3528 met study criteria, and 70 hearts (2%) were transplanted. The use of DCD hearts would represent an additional 48 heart transplants per month, which corresponds to a 21% (3458 of 16 521) increase across the country. Median warm ischemia was 23 minutes, with no difference between hearts that were or were not transplanted (23 vs 22.5 minutes, P = .97). The frequency with which other organs were successfully transplanted was kidney, 92%; liver, 44%; lung, 7%; intestine, 0%; and pancreas, 2%. CONCLUSIONS: Wide adoption of DCD heart transplantation could yield a substantial increase in the donor pool size, with approximately 580 additional organs being available each year across the United States. This would represent the largest increase in the donor pool in the modern era of heart transplantation.
Assuntos
Transplante de Coração , Obtenção de Tecidos e Órgãos , Adolescente , Adulto , Morte , Coração , Humanos , Pessoa de Meia-Idade , Doadores de Tecidos , Isquemia Quente , Adulto JovemRESUMO
BACKGROUND: The COVID-19 pandemic has uniquely affected the United States. We hypothesize that transplantation would be uniquely affected. METHODS: In this population-based cohort study, adult transplantation data were examined as time series data. Autoregressive-integrated-moving-average models of transplantation rates were developed using data from 1990 to 2019 to forecast the 2020 expected rates in a theoretical scenario if the pandemic did not occur to generate observed-to-expected (O/E) ratios. RESULTS: 32,594 transplants were expected in 2020, and only 30,566 occurred (O/E 0.94, CI 0.88-0.99). 58,152 waitlist registrations were expected and 50,241 occurred (O/E 0.86, CI 0.80-0.94). O/E ratios of transplants were kidney 0.92 (0.86-0.98), liver 0.96 (0.89-1.04), heart 1.05 (0.91-1.23), and lung 0.92 (0.82-1.04). O/E ratios of registrations were kidney 0.84 (0.77-0.93), liver 0.95 (0.86-1.06), heart 0.99 (0.85-1.18), and lung 0.80 (0.70-0.94). CONCLUSIONS: The COVID-19 pandemic was associated with a significant deficit in transplantation. The impact was strongest in kidney transplantation and waitlist registration.
Assuntos
COVID-19 , Transplante de Órgãos , Adulto , COVID-19/epidemiologia , Estudos de Coortes , Humanos , Pandemias , Estados Unidos/epidemiologia , Listas de EsperaRESUMO
Here, we describe a novel pathogenic entity, the activated PMN (polymorphonuclear leukocyte, i.e., neutrophil)-derived exosome. These CD63+/CD66b+ nanovesicles acquire surface-bound neutrophil elastase (NE) during PMN degranulation, NE being oriented in a configuration resistant to α1-antitrypsin (α1AT). These exosomes bind and degrade extracellular matrix (ECM) via the integrin Mac-1 and NE, respectively, causing the hallmarks of chronic obstructive pulmonary disease (COPD). Due to both ECM targeting and α1AT resistance, exosomal NE is far more potent than free NE. Importantly, such PMN-derived exosomes exist in clinical specimens from subjects with COPD but not healthy controls and are capable of transferring a COPD-like phenotype from humans to mice in an NE-driven manner. Similar findings were observed for another neutrophil-driven disease of ECM remodeling (bronchopulmonary dysplasia [BPD]). These findings reveal an unappreciated role for exosomes in the pathogenesis of disorders of ECM homeostasis such as COPD and BPD, providing a critical mechanism for proteolytic damage.
Assuntos
Exossomos/fisiologia , Neutrófilos/metabolismo , Animais , Líquido da Lavagem Broncoalveolar/citologia , Células Cultivadas , Matriz Extracelular/metabolismo , Feminino , Humanos , Inflamação , Integrinas , Elastase de Leucócito/metabolismo , Pulmão/metabolismo , Pulmão/fisiopatologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neutrófilos/fisiologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , alfa 1-Antitripsina/metabolismoRESUMO
Acute respiratory distress syndrome (ARDS) is characterized by unrelenting polymorphonuclear neutrophil (PMN) inflammation and vascular permeability. The matrikine proline-glycine-proline (PGP) and acetylated PGP (Ac-PGP) have been shown to induce PMN inflammation and endothelial permeability in vitro and in vivo. In this study, we investigated the presence and role of airway PGP peptides in acute lung injury (ALI)/ARDS. Pseudomonas aeruginosa-derived lipopolysaccharide (LPS) was instilled intratracheally in mice to induce ALI, and increased Ac-PGP with neutrophil inflammation was noted. The PGP inhibitory peptide, arginine-threonine-arginine (RTR), was administered (it) 30 min before or 6 h after LPS injection. Lung injury was evaluated by detecting neutrophil infiltration and permeability changes in the lung. Pre- and posttreatment with RTR significantly inhibited LPS-induced ALI by attenuating lung neutrophil infiltration, pulmonary permeability, and parenchymal inflammation. To evaluate the role of PGP levels in ARDS, minibronchoalveolar lavage was collected from nine ARDS, four cardiogenic edema, and five nonlung disease ventilated patients. PGP levels were measured and correlated with Acute Physiology and Chronic Health Evaluation (APACHE) score, PaO2 to FIO2 (P/F), and ventilator days. PGP levels in subjects with ARDS were significantly higher than cardiogenic edema and nonlung disease ventilated patients. Preliminary examination in both ARDS and non-ARDS populations demonstrated PGP levels significantly correlated with P/F ratio, APACHE score, and duration on ventilator. These results demonstrate an increased burden of PGP peptides in ARDS and suggest the need for future studies in ARDS cohorts to examine correlation with key clinical parameters.
Assuntos
Inflamação/etiologia , Lesão Pulmonar/etiologia , Infiltração de Neutrófilos/imunologia , Neutrófilos/imunologia , Oligopeptídeos/metabolismo , Prolina/análogos & derivados , Síndrome do Desconforto Respiratório/etiologia , Adulto , Animais , Permeabilidade Capilar , Estudos de Casos e Controles , Feminino , Humanos , Inflamação/metabolismo , Inflamação/patologia , Lesão Pulmonar/metabolismo , Lesão Pulmonar/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Neutrófilos/metabolismo , Neutrófilos/patologia , Prolina/metabolismo , Síndrome do Desconforto Respiratório/metabolismo , Síndrome do Desconforto Respiratório/patologiaRESUMO
BACKGROUND: Our objective was to compare the clinical to the pathologic stage in patients with non-small cell lung cancer (NSCLC). METHODS: A prospective database from 1 surgeon was reviewed. Patients had NSCLC, chest tomography (CT), and most had positron emission tomography (PET). Those with suggested N1, N2, central tumors, or tumors larger than 5 cm underwent mediastinoscopy or endobronchial ultrasound, or both, and if N2 negative, underwent resection with complete thoracic lymphadenectomy. RESULTS: Between January 2006 and December 2016, there were 1,444 consecutive patients. The sensitivity and specificity for CT was 76% and 79% for pathologic stage I, 48% and 89% for stage II, and 58% and 88% for stage III. The sensitivity and specificity for PET was 77% and 70% for pathologic stage I, 43% and 88% for stage II, and 46% and 93% for stage III. Pathologic N1 disease was proven in 7% of patients and missed in 4% by CT, 5% by PET, and 3% by both. Pathologic N2 disease was proven in 20% of patients and missed in 9% by CT, 10% by PET, and 8% by both. Occult N2 disease was present in 10% of clinically stage I patients and in 21% of clinically stage II patients. Independent predictors of occult N1 disease included high maximum standardized uptake value (p = 0.034) and predictors of N2 disease included African American race (p = 0.020) and large tumor size (p = 0.047). CONCLUSIONS: Despite advancements in CT, PET, and minimally invasive nodal biopsy, there remains significant NSCLC misstaging, especially for N2 disease. Improved, targeted N2 lymph node biopsy may improve preresection staging.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Mediastinoscopia/métodos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia por Agulha , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Estudos de Coortes , Bases de Dados Factuais , Erros de Diagnóstico , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Imuno-Histoquímica , Neoplasias Pulmonares/mortalidade , Excisão de Linfonodo/métodos , Linfonodos/patologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Invasividade Neoplásica/patologia , Estudos Retrospectivos , Medição de Risco , Sensibilidade e Especificidade , Análise de SobrevidaRESUMO
The backbone of effective highly active antiretroviral therapy regimens for the treatment of HIV infections currently contains at least two nucleosides. Among the features that influence the potency of each component of a regimen and the overall efficacy of the combination are the cellular uptake and bioconversion of nucleoside analogues to their active triphosphate form, and the extent of possible interactions in these steps that might occur when more than one nucleoside is used in a regimen. D-d4FC (Reverset), a new cytidine analogue with the ability to inhibit many nucleoside-resistant viral variants, was examined for these parameters. In phytohemaglutinin-stimulated human peripheral blood mononuclear cells, D-d4FC was taken up in a rapid (8 h to 50% maximal value), saturable (plateau above 10 microM parent nucleoside concentration) process, resulting in levels of D-d4FC triphosphate that should provide potent antiviral activity against a variety of virus genotypes. Based on measurement of antiviral effects in cell culture, additive and in some cases, synergistic interactions were observed with protease inhibitors, non-nucleoside reverse transcriptase inhibitors or other nucleosides, including cytidine analogues.
Assuntos
Fármacos Anti-HIV/farmacologia , Citidina Trifosfato/farmacologia , Farmacorresistência Viral , HIV-1/efeitos dos fármacos , Leucócitos Mononucleares/efeitos dos fármacos , Inibidores da Transcriptase Reversa/farmacologia , Células Cultivadas , Citidina Trifosfato/análogos & derivados , Citidina Trifosfato/metabolismo , Interações Medicamentosas , Inibidores da Protease de HIV/farmacologia , Transcriptase Reversa do HIV/antagonistas & inibidores , HIV-1/fisiologia , Humanos , Membranas Intracelulares/metabolismo , Leucócitos Mononucleares/metabolismo , Nucleosídeos/química , Nucleosídeos/farmacologia , Fosforilação/efeitos dos fármacos , Fito-Hemaglutininas , Zalcitabina/análogos & derivadosRESUMO
Amyloid precursor protein (APP) cleaving enzyme (BACE) is the enzyme responsible for beta-site cleavage of APP, leading to the formation of the amyloid-beta peptide that is thought to be pathogenic in Alzheimer's disease (AD). Hence, BACE is an attractive pharmacological target, and numerous research groups have begun searching for potent and selective inhibitors of this enzyme as a potential mechanism for therapeutic intervention in AD. The mature enzyme is composed of a globular catalytic domain that is N-linked glycosylated in mammalian cells, a single transmembrane helix that anchors the enzyme to an intracellular membrane, and a short C-terminal domain that extends outside the phospholipid bilayer of the membrane. Here we have compared the substrate and active site-directed inhibitor binding properties of several recombinant constructs of human BACE. The constructs studied here address the importance of catalytic domain glycosylation state, inclusion of domains other than the catalytic domain, and incorporation into a membrane bilayer on the interactions of the enzyme active site with peptidic ligands. We find no significant differences in ligand binding properties among these various constructs. These data demonstrate that the nonglycosylated, soluble catalytic domain of BACE faithfully reflects the ligand binding properties of the full-length mature enzyme in its natural membrane environment. Thus, the use of the nonglycosylated, soluble catalytic domain of BACE is appropriate for studies aimed at understanding the determinants of ligand recognition by the enzyme active site.
Assuntos
Ácido Aspártico Endopeptidases/química , Proteínas Recombinantes/química , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide , Animais , Ácido Aspártico Endopeptidases/metabolismo , Sítios de Ligação , Células CHO , Catálise , Domínio Catalítico , Linhagem Celular , Membrana Celular/metabolismo , Cromatografia Líquida de Alta Pressão , Cricetinae , Relação Dose-Resposta a Droga , Drosophila , Endopeptidases , Escherichia coli/metabolismo , Glicosilação , Humanos , Concentração Inibidora 50 , Cinética , Ligantes , Luz , Bicamadas Lipídicas/metabolismo , Peptídeos/química , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas Recombinantes/metabolismo , Espalhamento de Radiação , Fatores de TempoRESUMO
Efavirenz and a series of related quinazolinone nonnucleoside inhibitors of the human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) were evaluated in a series of two-drug combinations with several nucleoside RT inhibitors (NRTIs), nonnucleoside RT inhibitors (NNRTIs), and protease inhibitors (PIs). These combinations were tested in an established HIV-1 RT enzyme assay and a cell-based yield reduction assay with HIV-1 (replicative form [RF])-infected MT-2 cells. Synergy, additivity, and antagonism were determined in the two different assay systems by the method of Chou and Talalay (T.-C. Chou and P. Talalay, Adv. Enzyme Reg. 22:27-55, 1984). Efavirenz, DPC082, DPC083, DPC961, and DPC963 used in combination with the NRTIs zidovudine and lamivudine acted synergistically to inhibit RT activity in the HIV-1 RT enzyme assay and additively to slightly synergistically to inhibit HIV-1 (RF) replication in the yield reduction assay. The five NNRTIs in combination with the PI nelfinavir acted additively in the yield reduction assay to inhibit HIV-1 replication. Interestingly, efavirenz in combination with a second NNRTI acted additively to inhibit HIV-1 RT function in the enzyme assay, while it acted antagonistically to inhibit HIV-1 (RF) replication in the yield reduction assay. These data suggest that antiretroviral combination regimens containing multiple NNTRIs should be given thorough consideration before being used.
Assuntos
Inibidores da Protease de HIV/farmacologia , HIV-1/efeitos dos fármacos , Inibidores da Transcriptase Reversa/farmacologia , Alcinos , Benzoxazinas , Células Cultivadas , Ciclopropanos , Combinação de Medicamentos , Interações Medicamentosas , Transcriptase Reversa do HIV/biossíntese , HIV-1/enzimologia , Humanos , Nevirapina/farmacologia , Nucleosídeos/farmacologia , Oxazinas/farmacologia , Replicação Viral/efeitos dos fármacosRESUMO
The inability of hepatitis C virus (HCV) to replicate in cell culture has hindered the discovery of antiviral agents against this virus. One of the biggest challenges has been to find a model that allows one to easily and accurately quantify the level of HCV RNA replication that is occurring inside the cell. In an attempt to solve this problem, we have created a plasmid pMJ050 that encodes a chimeric 'HCV-like' RNA that can act as a reporter for HCV RNA replication. This RNA consists of an antisense copy of the firefly luciferase sequence flanked by the 5' and 3' untranslated regions of the negative strand of the HCV RNA. If, in cells that contain functional HCV proteins, the chimeric RNA is recognized as a substrate for the viral RNA-dependent RNA polymerase, the chimeric RNA will be transcribed into the complementary strand. This RNA has a 5' HCV internal ribosome entry site and the luciferase sequence in the coding orientation, allowing translation of the RNA into biologically active luciferase. When pMJ050 was transfected into a cell line that is stably transfected with a cDNA copy of the HCV 1b genome, luciferase was produced in a manner that was dependent upon the presence of at least a functional HCV RNA-dependent RNA polymerase. In addition, we constructed a cell line, 293B4alpha that constitutively produced luciferase in response to the presence of functional HCV proteins. This system permits the accurate determination of the level of HCV RNA replication by the quantification of luciferase.
Assuntos
Hepacivirus/fisiologia , Modelos Genéticos , RNA Viral/genética , Replicação Viral/fisiologia , Linhagem Celular , Genes Reporter , Células HeLa/virologia , Hepacivirus/genética , Hepatócitos/virologia , Humanos , Rim , Luciferases/biossíntese , Luciferases/genética , Plasmídeos/genética , RNA Helicases/metabolismo , RNA Antissenso/genética , RNA Viral/biossíntese , RNA Polimerase Dependente de RNA/metabolismo , Proteínas Recombinantes de Fusão/biossíntese , Sequências Reguladoras de Ácido Nucleico , Replicon , Moldes Genéticos , Transfecção , Proteínas não Estruturais Virais/metabolismo , Replicação Viral/genéticaRESUMO
The development of low molecular weight inhibitors of hepatitis C virus (HCV) replication has been hindered by the lack of a good cell-based system that models the entire HCV replication cycle. To date the only two therapies approved for the treatment of HCV infection are interferon (IFN)-alpha and the nucleoside analogue, ribavirin. We have created a cell-based system that allows for the accurate quantification of the replication of an HCV-like RNA template by proteins that are encoded for by the HCV genome. The system consists of a cell line that constitutively produces luciferase in response to the production of functional HCV replicative proteins. The 293B4alpha cell line has been formatted into a semi-high throughput, cell-based screen for inhibitors of HCV replication. When these cells were treated with either IFN-alpha or -beta, luciferase production decreased in a dose-responsive manner. Counterscreening these molecules in another cell line, 293SVLuc, in which luciferase production in not dependent the presence of functional HCV proteins, showed that the inhibition of luciferase in the 293B4alpha cell line was due to inhibition of the replication of the HCV-like RNA template and not anti-cellular or -luciferase activity. Moreover, when the 293B4alpha cell line was treated with the ribonucleoside analogue, 3'-deoxycytidine, luciferase decreased in a dose-responsive manner. 3'-deoxyguanosine and 3'-deoxyuridine did not inhibit luciferase production and 3'-deoxyadenosine was too cytotoxic to determine if it had any anti-HCV activity.
Assuntos
Antivirais/farmacologia , Desoxicitidina/farmacologia , Hepacivirus/efeitos dos fármacos , Interferon-alfa/farmacologia , Interferon beta/farmacologia , RNA Viral/biossíntese , Replicação Viral/efeitos dos fármacos , Linhagem Celular/virologia , Desoxiadenosinas/farmacologia , Desoxicitidina/análogos & derivados , Desoxiguanosina/análogos & derivados , Desoxiguanosina/farmacologia , Desoxiuridina/análogos & derivados , Desoxiuridina/farmacologia , Relação Dose-Resposta a Droga , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Genes Reporter , Células HeLa/virologia , Hepacivirus/genética , Hepacivirus/fisiologia , Hepatócitos/virologia , Humanos , Rim , Luciferases/biossíntese , Luciferases/genética , RNA Viral/genética , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética , Ribavirina/farmacologia , Moldes GenéticosRESUMO
By passing wild type bovine viral diarrhoea virus (BVDV) in increasing concentrations of DPC-A69280-29, a thiazole urea class compound that inhibits BVDV replication, we were able to select several variants of BVDV that exhibited decreased susceptibility to this compound. When the non-structural genes of these variants were sequenced and compared with wild type, only one change was common to all the variants that also exhibited resistance to DPC-A69280-29 (>10-fold increase in IC50). This change was a T-to-A transversion at position 11198 of the BVDV genome, which would cause a predicted substitution of isoleucine for phenylalanine at amino acid 78 of the RNA-dependent RNA polymerase (RdRp). This substitution would occur in a region of the BVDV RdRp which has been proposed to be important for the formation of the RdRp homodimer that is essential for the activity of the enzyme. However, since DPC-69280-29 inhibits BVDV replication by interfering with the initiation of viral RNA synthesis, we discuss the possibility that this region of the BVDV RdRp also may play a role in the initiation process. Furthermore, since this region is located fairly close to the template RNA, we also propose that the role it plays may involve either template selection, stabilization or processivity.
Assuntos
Antivirais/farmacologia , Vírus da Diarreia Viral Bovina/efeitos dos fármacos , Vírus da Diarreia Viral Bovina/genética , Farmacorresistência Viral/genética , RNA Polimerase Dependente de RNA/genética , Seleção Genética , Tiazóis/farmacologia , Ureia/farmacologia , Animais , Antivirais/química , Linhagem Celular , Vírus da Diarreia Viral Bovina/enzimologia , Vírus da Diarreia Viral Bovina/fisiologia , Concentração Inibidora 50 , Estrutura Molecular , RNA Viral/biossíntese , RNA Viral/genética , Tiazóis/química , Ureia/análogos & derivados , Ureia/química , Replicação Viral/efeitos dos fármacosRESUMO
This meeting was attended by several hundred delegates and covered, in lecture and poster presentations, recent developments in basic, applied and clinical research as they concern antiviral drug development for hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. Below are summaries of presentations that are relevant to the development of antiviral drug resistance. Copyright 2000 Harcourt Publishers Ltd.