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1.
HIV Med ; 22(1): 28-36, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32964664

RESUMEN

OBJECTIVES: We aimed to compare the effectiveness of antiretroviral therapy (ART) classes for achieving HIV RNA suppression to < 50 HIV-1 RNA copies/mL within 6 months of initiation with high viral loads (VLs). Secondary objectives were to compare viral suppression (VS) at 12 weeks and 12 months, partial HIV RNA suppression to < 200 copies/mL, time to VS, time to rebound, and change in CD4 cell count. METHODS: This was a multicentre, retrospective, observational study. Adult patients were included if they initiated ART between January 2005 and December 2016 with a VL ≥ 100 000 copies/mL. RESULTS: There were 220 patients included in the study. The median VL was 252 919 [interquartile range (IQR) 149 472-500 000] copies/mL. Nonnucleoside reverse transcriptase inhibitor (NNRTI) recipients were more likely to achieve VS by 6 months compared to those initiating ART containing protease inhibitors (PIs) [75.4% vs. 44.1%, respectively; odds ratio (OR) 3.34; 95% confidence interval (CI) 1.62-6.90] or integrase strand transfer inhibitors (INSTIs) (75.4% vs. 55.8%, respectively; OR 2.40; 95% CI 1.03-5.58). VS at 12 weeks was more frequent with INSTI-containing regimens than with PIs (28.9% vs. 9.0%, respectively; OR 4.10; 95% CI 1.69-9.92). VS at 12 months did not significantly differ between treatment regimens. Median time to complete VS for INSTI, PI and NNRTI recipients was 22.3 (95% CI 13.4-33), 30.1 (95% CI 25-36) and 19.9 (95% CI 16-22.3) weeks, respectively. There were no significant differences in time to viral rebound or change in CD4 cell counts. CONCLUSIONS: Patients with high VLs initiated on NNRTIs were more likely to achieve VS by 6 months on ART compared to INSTI and PI recipients.


Asunto(s)
Infecciones por VIH/tratamiento farmacológico , Inhibidores de Integrasa VIH/uso terapéutico , Inhibidores de la Transcriptasa Inversa/uso terapéutico , Carga Viral/efectos de los fármacos , Adulto , Terapia Antirretroviral Altamente Activa , Femenino , Infecciones por VIH/virología , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Carga Viral/estadística & datos numéricos
2.
Front Digit Health ; 6: 1435693, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39253055

RESUMEN

Introduction: Digital health technologies (DHTs) have the potential to alleviate challenges experienced in clinical trials through more objective, naturalistic, and frequent assessments of functioning. However, implementation of DHTs come with their own challenges, including acceptability and ease of use for study participants. In addition to acceptability, it is also important to understand device proficiency in the general population and within patient populations who may be asked to use DHTs for extended periods of time. We thus aimed to provide an overview of participant feedback on acceptability of DHTs, including body-worn sensors used in the clinic and a mobile application used at-home, used throughout the duration of the Wearable Assessments in the Clinic and at Home in Parkinson's Disease (WATCH-PD) study, an observational, longitudinal study looking at disease progression in early Parkinson's Disease (PD). Methods: 82 participants with PD and 50 control participants were enrolled at 17 sites throughout the United States and followed for 12 months. We assessed participants' general device proficiency at baseline, using the Mobile Device Proficiency Questionnaire (MDPQ). The mean MDPQ score at Baseline did not significantly differ between PD patients and healthy controls (20.6 [2.91] vs 21.5 [2.94], p = .10). Results: Questionnaire results demonstrated that participants had generally positive views on the comfort and use of the digital technologies throughout the duration of the study, regardless of group. Discussion: This is the first study to evaluate patient feedback and impressions of using technology in a longitudinal observational study in early Parkinson's Disease. Results demonstrate device proficiency and acceptability of various DHTs in people with Parkinson's does not differ from that of neurologically healthy older adults, and, overall, participants had a favorable view of the DHTs deployed in the WATCH-PD study.

3.
HIV Med ; 14(7): 401-9, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23433482

RESUMEN

OBJECTIVES: The pharmacokinetics (PK) of antiretrovirals (ARVs) in older HIV-infected patients are poorly described. Here, the steady-state PK of two common ARV regimens [tenofovir (TFV)/emtricitabine (FTC)/efavirenz (EFV) and TFV/FTC/atazanavir (ATV)/ritonavir (RTV)] in older nonfrail HIV-infected patients are presented. METHODS: HIV-infected subjects ≥ 55 years old not demonstrating the frailty phenotype were enrolled in an unblinded, intensive-sampling PK study. Blood plasma (for TFV, FTC, EFV, ATV and RTV concentrations) and peripheral blood mononuclear cells [PBMCs; for tenofovir diphosphate (TFV-DP) and emtricitabine triphosphate (FTC-TP) concentrations] were collected at 11 time-points over a 24-hour dosing interval. Drug concentrations were analysed using validated liquid chromatography-ultraviolet detection (LC-UV) or liquid chromatography tandem mass spectrometry (LC-MS/MS) methods. Noncompartmental pharmacokinetic analysis was used to estimate PK parameters [area under the concentration-time curve over 24 h (AUC0-24h ) and maximal concentration (Cmax )]. These parameters were compared with historical values from the general HIV-infected population. RESULTS: Six subjects on each regimen completed the study. Compared with the general population, these elderly subjects had 8-13% decreased TFV AUC0-24h and Cmax , and 19-78% increased FTC and RTV AUC0-24h and Cmax . Decreased ATV AUC0-24h (12%) and increased Cmax (9%) were noted, while EFV exposure was unchanged (5%) with a 16% decrease in Cmax . Intracellular nucleoside/tide metabolite concentrations and AUC are also reported for these subjects. CONCLUSIONS: This study demonstrates that the PK of these ARVs are altered by 5-78% in an older HIV-infected population. Implications of PK differences for clinical outcomes, particularly with the active nucleoside metabolites, remain to be explored. This study forms the basis for further study of ARV PK, efficacy, and toxicity in older HIV-infected patients.


Asunto(s)
Adenina/análogos & derivados , Fármacos Anti-VIH/farmacocinética , Benzoxazinas/farmacocinética , Desoxicitidina/análogos & derivados , Infecciones por VIH/tratamiento farmacológico , Oligopéptidos/farmacocinética , Organofosfonatos/farmacocinética , Piridinas/farmacocinética , Ritonavir/farmacocinética , Adenina/administración & dosificación , Adenina/farmacocinética , Adenina/uso terapéutico , Negro o Afroamericano/etnología , Anciano , Alquinos , Fármacos Anti-VIH/administración & dosificación , Fármacos Anti-VIH/uso terapéutico , Sulfato de Atazanavir , Benzoxazinas/administración & dosificación , Benzoxazinas/uso terapéutico , Ciclopropanos , Interpretación Estadística de Datos , Desoxicitidina/administración & dosificación , Desoxicitidina/farmacocinética , Desoxicitidina/uso terapéutico , Emtricitabina , Femenino , Anciano Frágil , VIH/efectos de los fármacos , VIH/patogenicidad , Infecciones por VIH/virología , Humanos , Masculino , Persona de Mediana Edad , Oligopéptidos/administración & dosificación , Oligopéptidos/uso terapéutico , Organofosfonatos/administración & dosificación , Organofosfonatos/uso terapéutico , Proyectos Piloto , Piridinas/administración & dosificación , Piridinas/uso terapéutico , Ritonavir/administración & dosificación , Ritonavir/uso terapéutico , Tenofovir , Población Blanca/etnología
4.
Osteoporos Int ; 24(4): 1195-206, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23100119

RESUMEN

UNLABELLED: We examined the association between osteoporosis treatment change and adherence, incident fractures, and healthcare costs among Medicare Advantage Prescription Drug (MAPD) plan members. Treatment change was associated with a small but significant increase in adherence, but was not associated with incident fracture or total healthcare costs. Overall adherence remained low. INTRODUCTION: We examined the association between osteoporosis treatment change and adherence, incident fractures, and healthcare costs among MAPD plan members in a large US health plan. METHODS: We conducted a retrospective cohort study of MAPD plan members aged≥50 years newly initiated on an osteoporosis medication between 1 January 2006 and 31 December 2008. Members were identified as having or not having an osteoporosis treatment change within 12 months after initiating osteoporosis medication. Logistic regression analyses and difference-in-difference (DID) generalized linear models were used to investigate the association between osteoporosis treatment change and (1) adherence to treatment, (2) incident fracture, and (3) healthcare costs at 12 and 24 months follow-up. RESULTS: Of the 33,823 members newly initiated on osteoporosis treatment, 3,573 (10.6%) changed osteoporosis treatment within 12 months. After controlling for covariates, osteoporosis treatment change was associated with significantly higher odds of being adherent (medication possession ratio [MPR]≥0.8) at 12 months (odds ratio [OR]=1.18) and 24 months (OR=1.13) follow-up. However, overall adherence remained low (MPR=0.59 and 0.51 for the change cohort and MPR=0.51 and 0.44 for the no-change cohort at 12 and 24 months, respectively). Osteoporosis treatment change was not significantly associated with incident fracture (OR=1.00 at 12 months and OR=0.98 at 24 months) or total direct healthcare costs (p>0.4) in the DID analysis, but was associated with higher pharmacy costs (p<0.004). CONCLUSIONS: Osteoporosis treatment change was associated with a small but significant increase in adherence, but was not associated with incident fracture or total healthcare costs in the MAPD plan population. Overall adherence to therapy remained low.


Asunto(s)
Conservadores de la Densidad Ósea/uso terapéutico , Costos de la Atención en Salud/estadística & datos numéricos , Cumplimiento de la Medicación/estadística & datos numéricos , Osteoporosis/tratamiento farmacológico , Fracturas Osteoporóticas/prevención & control , Anciano , Anciano de 80 o más Años , Conservadores de la Densidad Ósea/economía , Costos de los Medicamentos/estadística & datos numéricos , Sustitución de Medicamentos/economía , Sustitución de Medicamentos/estadística & datos numéricos , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Masculino , Medicare Part C/economía , Persona de Mediana Edad , Osteoporosis/economía , Osteoporosis/epidemiología , Fracturas Osteoporóticas/economía , Fracturas Osteoporóticas/epidemiología , Estados Unidos/epidemiología
5.
Comput Graph Forum ; 42(3): 423-435, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38505301

RESUMEN

Generative text-to-image models (as exemplified by DALL-E, MidJourney, and Stable Diffusion) have recently made enormous technological leaps, demonstrating impressive results in many graphical domains-from logo design to digital painting to photographic composition. However, the quality of these results has led to existential crises in some fields of art, leading to questions about the role of human agency in the production of meaning in a graphical context. Such issues are central to visualization, and while these generative models have yet to be widely applied in visualization, it seems only a matter of time until their integration is manifest. Seeking to circumvent similar ponderous dilemmas, we attempt to understand the roles that generative models might play across visualization. We do so by constructing a framework that characterizes what these technologies offer at various stages of the visualization workflow, augmented and analyzed through semi-structured interviews with 21 experts from related domains. Through this work, we map the space of opportunities and risks that might arise in this intersection, identifying doomsday prophecies and delicious low-hanging fruits that are ripe for research.

6.
Structure ; 6(9): 1117-28, 1998 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-9753691

RESUMEN

BACKGROUND: The mitogen-activated protein (MAP) kinases are important signaling molecules that participate in diverse cellular events and are potential targets for intervention in inflammation, cancer, and other diseases. The MAP kinase p38 is responsive to environmental stresses and is involved in the production of cytokines during inflammation. In contrast, the activation of the MAP kinase ERK2 (extracellular-signal-regulated kinase 2) leads to cellular differentiation or proliferation. The anti-inflammatory agent pyridinylimidazole and its analogs (SB [SmithKline Beecham] compounds) are highly potent and selective inhibitors of p38, but not of the closely-related ERK2, or other serine/threonine kinases. Although these compounds are known to bind to the ATP-binding site, the origin of the inhibitory specificity toward p38 is not clear. RESULTS: We report the structural basis for the exceptional selectivity of these SB compounds for p38 over ERK2, as determined by comparative crystallography. In addition, structural data on the origin of olomoucine (a better inhibitor of ERK2) selectivity are presented. The crystal structures of four SB compounds in complex with p38 and of one SB compound and olomoucine in complex with ERK2 are presented here. The SB inhibitors bind in an extended pocket in the active site and are complementary to the open domain structure of the low-activity form of p38. The relatively closed domain structure of ERK2 is able to accommodate the smaller olomoucine. CONCLUSIONS: The unique kinase-inhibitor interactions observed in these complexes originate from amino-acid replacements in the active site and replacements distant from the active site that affect the size of the domain interface. This structural information should facilitate the design of better MAP-kinase inhibitors for the treatment of inflammation and other diseases.


Asunto(s)
Proteínas Quinasas Dependientes de Calcio-Calmodulina/antagonistas & inhibidores , Inhibidores Enzimáticos/química , Proteína Quinasa 1 Activada por Mitógenos/antagonistas & inhibidores , Proteínas Quinasas Activadas por Mitógenos , Adenosina Trifosfato/metabolismo , Dominio Catalítico/efectos de los fármacos , Diferenciación Celular , División Celular , Cristalografía por Rayos X , Inhibidores Enzimáticos/farmacología , Humanos , Imidazoles/química , Imidazoles/farmacología , Cinetina , Modelos Químicos , Modelos Moleculares , Conformación Proteica , Purinas/química , Purinas/farmacología , Piridinas/química , Piridinas/farmacología , Pirimidinas/farmacología , Relación Estructura-Actividad , Proteínas Quinasas p38 Activadas por Mitógenos
7.
Sci Total Environ ; 572: 1636-1644, 2016 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-26996523

RESUMEN

To predict ecosystem responses to anthropogenic change it is important to understand how and where plant productivity is limited by macronutrient availability. Nitrogen (N) is required in large quantities for plant growth, and is readily lost through leaching or gas fluxes, but reactive nitrogen can be obtained through dinitrogen fixation, and phosphorus (P) is often considered a more fundamental long-term constraint to growth and carbon sequestration in terrestrial ecosystems. Phosphorus limitation may be becoming more prevalent due to widespread pollution by atmospheric N. Assessments of the effects of macronutrient availability on productivity in natural ecosystems are however scarce. We measured standing biomass of bracken Pteridium aquilinum as a proxy for productivity across sites with similar climate but varied geology. Total above-ground biomass varied from 404 to 1947gm-2, yet despite 12-fold to 281-fold variation in soil macronutrient stocks these were remarkably poor at explaining variation in productivity. Soil total nitrogen, organic phosphorus, calcium, magnesium and zinc had no relationship with productivity, whether expressed as concentrations, stocks or element/C ratios, and nor did foliar N/P. Soil potassium (K) and molybdenum stocks both showed weak relationships with productivity. The stock of K in bracken biomass was considerably greater as a proportion of soil stock than for other nutrient elements, suggesting that this nutrient element can be important in determining productivity. Moisture availability, as indicated by environmental trait scores for plant species present, explained considerably more of the variation in productivity than did K stock, with less production in wetter sites. Soil N/C ratio and organic P stock were relatively unimportant in determining productivity across these bracken sites. It is possible that more-direct measures of N and P availability would explain variation in productivity, but the study shows the importance of considering other essential elements and other environmental factors when predicting productivity.


Asunto(s)
Carbono/metabolismo , Nitrógeno/metabolismo , Fósforo/metabolismo , Pteridium/crecimiento & desarrollo , Suelo/química , Biomasa , Secuestro de Carbono , Pteridium/metabolismo
8.
Circulation ; 104(11): 1292-8, 2001 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-11551882

RESUMEN

BACKGROUND: Numerous pathological mediators of cardiac hypertrophy (eg, neurohormones, cytokines, and stretch) have been shown to activate p38 MAPK. The purpose of the present study was to examine p38 MAPK activation and the effects of its long-term inhibition in a model of hypertensive cardiac hypertrophy/dysfunction and end-organ damage. METHODS AND RESULTS: In spontaneously hypertensive stroke-prone (SP) rats receiving a high-salt/high-fat diet (SFD), myocardial p38 MAPK was activated persistently during the development of cardiac hypertrophy and inactivated during decompensation. Long-term oral treatment of SFD-SP rats with a selective p38 MAPK inhibitor (SB239063) significantly enhanced survival over an 18-week period compared with the untreated group (100% versus 50%). Periodic echocardiographic analysis revealed a significant reduction in LV hypertrophy and dysfunction in the SB239063-treatment groups. Little or no difference in blood pressure was noted in the treatment or vehicle groups. Basal and stimulated (lipopolysaccharide) plasma tumor necrosis factor-alpha concentrations were reduced in the SB239063-treatment groups. In vitro vasoreactivity studies demonstrated a significant preservation of endothelium-dependent relaxation in animals treated with the p38 MAPK inhibitor without effects on contraction or NO-mediated vasorelaxation. Proteinuria and the incidence of stroke (53% versus 7%) were also reduced significantly in the SB239063-treated groups. CONCLUSIONS: These results demonstrate a crucial role for p38 MAPK in hypertensive cardiac hypertrophy and end-organ damage. Interrupting its function with a specific p38 MAPK inhibitor halts clinical deterioration.


Asunto(s)
Cardiomegalia/fisiopatología , Hipertensión/fisiopatología , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Animales , Cardiomegalia/enzimología , Cardiomegalia/mortalidad , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Ecocardiografía , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/fisiopatología , Activación Enzimática , Corazón/efectos de los fármacos , Corazón/fisiopatología , Hemodinámica/efectos de los fármacos , Imidazoles/farmacología , Riñón/efectos de los fármacos , Riñón/fisiopatología , Lipopolisacáridos/farmacología , Masculino , Proteínas Quinasas Activadas por Mitógenos/antagonistas & inhibidores , Miocardio/metabolismo , Miocardio/patología , Fosforilación , Proteinuria/prevención & control , Proteinuria/orina , Pirimidinas/farmacología , Ratas , Ratas Endogámicas SHR , Ratas Endogámicas WKY , Accidente Cerebrovascular/patología , Accidente Cerebrovascular/prevención & control , Tasa de Supervivencia , Factores de Tiempo , Factor de Necrosis Tumoral alfa/efectos de los fármacos , Factor de Necrosis Tumoral alfa/metabolismo , Vasodilatación/efectos de los fármacos , Proteínas Quinasas p38 Activadas por Mitógenos
9.
J Clin Oncol ; 19(1): 105-10, 2001 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-11134202

RESUMEN

PURPOSE: To summarize evidence on the costs of treating patients in clinical trials and to describe the Cost of Cancer Treatment Study, an ongoing effort to produce generalizable estimates of the incremental costs of government-sponsored cancer trials. METHODS: A retrospective study of costs will be conducted with 1,500 cancer patients recruited from a randomly selected sample of institutions in the United States. Patients accrued to either phase II or phase III National Cancer Institute-sponsored clinical trials during a 15-month period will be asked to participate in a study of their health care utilization (n = 750). Costs will be measured approximately 1 year after their trial enrollment from a combination of billing records, medical records, and an in-person survey questionnaire. Similar data will be collected for a comparable group of cancer patients not in trials (n = 750) to provide an estimate of the incremental cost. RESULTS: Evidence suggests insurers limit access to trials because of cost concerns. Public and private efforts are underway to change these policies, but their permanent status is unclear. Previous studies found that treatment costs in clinical trials are similar to costs of standard therapy. However, it is difficult to generalize from these studies because of the unique practice settings, insufficient sample sizes, and the exclusion of potentially important costs. CONCLUSION: Denials of coverage for treatment in a clinical trial limit patient access to trials and could impede clinical research. Preliminary estimates suggest changes to these policies would not be expensive, but these results are not generalizable. The Cost of Cancer Treatment Study is an ongoing effort to provide generalizable estimates of the incremental treatment cost of phase II and phase III cancer trials. The results should be of great interest to insurers and the research community as they consider permanent ways to finance cancer trials.


Asunto(s)
Ensayos Clínicos como Asunto/economía , Costos de la Atención en Salud , Planificación en Salud , Cobertura del Seguro , Seguro de Salud , Neoplasias/economía , Ensayos Clínicos Fase II como Asunto/economía , Ensayos Clínicos Fase III como Asunto/economía , Accesibilidad a los Servicios de Salud , Humanos , Proyectos de Investigación , Estudios Retrospectivos , Estados Unidos
10.
Pharmacol Ther ; 82(2-3): 389-97, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10454214

RESUMEN

The pyridinylimidazole compounds, exemplified by SB 203580, originally were prepared as inflammatory cytokine synthesis inhibitors. Subsequently, the compounds were found to be selective inhibitors for p38 mitogen-activated protein kinase (MAPK), a member of the MAPK family. SB 203580 inhibits the catalytic activity of p38 MAPK by competitive binding in the ATP pocket. Four homologues of p38 MAPK have been identified to date, and interestingly, their biochemical properties and their respective sensitivities to the inhibitors are distinct. X-ray crystallographic analysis of p38-inhibitor complexes reinforces the observations made from site-directed mutagenesis studies, thereby providing a molecular basis for understanding the kinase selectivity of these inhibitors. The p38 MAPK inhibitors are efficacious in several disease models, including inflammation, arthritis and other joint diseases, septic shock, and myocardial injury.


Asunto(s)
Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/uso terapéutico , Quinasas de Proteína Quinasa Activadas por Mitógenos/antagonistas & inhibidores , Mitógenos/fisiología , Compuestos de Piridinio/farmacología , Quimiocinas/fisiología , Predicción , Imidazoles/farmacología , Inflamación/tratamiento farmacológico , Estructura Molecular , Unión Proteica , Piridinas/farmacología , Homología de Secuencia de Aminoácido
11.
Curr Opin Biotechnol ; 6(6): 657-61, 1995 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8527836

RESUMEN

Several serine/threonine kinase inhibitors have been described recently that are sufficiently selective, and therefore useful as biochemical probes, for studying the role of kinases in signaling pathways. In addition, these newer classes of kinase inhibitor may well provide an impetus for the development of drugs to attenuate certain cellular responses in the treatment of diseases. Importantly, within the past year, specific and potent inhibitiors have been reported for both the new mitogen-activated protein (MAP) kinase homolog CSBP and MAP kinase kinase-1.


Asunto(s)
Inhibidores Enzimáticos/farmacología , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Secuencia de Aminoácidos , Animales , Biotecnología , Proteínas Quinasas Dependientes de Calcio-Calmodulina/antagonistas & inhibidores , Proteínas Quinasas Dependientes de Calcio-Calmodulina/genética , Proteínas Quinasas Dependientes de AMP Cíclico/antagonistas & inhibidores , Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Diseño de Fármacos , Inhibidores Enzimáticos/química , Humanos , Técnicas In Vitro , Datos de Secuencia Molecular , Estructura Molecular , Proteína Quinasa C/antagonistas & inhibidores , Proteínas Serina-Treonina Quinasas/genética
12.
J Leukoc Biol ; 48(6): 549-56, 1990 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-2230600

RESUMEN

In this study, we demonstrate that freshly adherent bovine monocytes release tumor necrosis factor-alpha (TNF-alpha) in response to stimulation with bacterial lipopolysaccharide (LPS). TNF-alpha was detected using actinomycin D-treated WEHI-164 murine fibrosarcoma cells as targets in an 18 hr cytotoxicity assay. Doses of LPS from 20 ng/ml to 20 micrograms/ml were capable of inducing bovine TNF-alpha. The kinetics of TNF-alpha release from bovine monocytes demonstrated peak levels of cytotoxic activity at 1-3 hr post-LPS treatment, with a subsequent decline to background levels by 18 hr post-LPS treatment. A monoclonal antibody that neutralizes recombinant human TNF-alpha (rHuTNF-alpha) significantly reduced the cytotoxicity of LPS-stimulated bovine monocyte culture supernatants. Size exclusion high-performance liquid chromatography (HPLC) analysis of LPS-stimulated monocyte and alveolar macrophage culture supernatants resulted in a molecular weight elution profile similar to that of recombinant human TNF-alpha. These elution profiles are consistent with the presence of multimers of TNF-alpha. This is believed to be the first report of the in vitro production of bovine TNF-alpha.


Asunto(s)
Lipopolisacáridos/farmacología , Macrófagos/efectos de los fármacos , Monocitos/efectos de los fármacos , Factor de Necrosis Tumoral alfa/metabolismo , Animales , Bovinos , Línea Celular , Cromatografía Líquida de Alta Presión , Relación Dosis-Respuesta a Droga , Técnicas In Vitro , Macrófagos/metabolismo , Ratones , Ratones Endogámicos BALB C , Monocitos/metabolismo , Alveolos Pulmonares/efectos de los fármacos , Alveolos Pulmonares/metabolismo , Factor de Necrosis Tumoral alfa/inmunología
13.
J Leukoc Biol ; 55(6): 719-22, 1994 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8195697

RESUMEN

The purpose of this study was to determine the influence of endogenous interleukin-1 (IL-1) on resistance to paratuberculosis infection in experimentally infected gnotobiotic mice. Following a 6-month treatment with prednisolone to facilitate bacillary multiplication, control mice substantially reduced the numbers of M. paratuberculosis in the liver and ileum. In contrast, mice injected with a monoclonal antibody against the type I IL-1 receptor failed to reduce the numbers of M. paratuberculosis in the liver and ileum and exhibited more liver granulomas, which contained numerous acid-fast bacilli. These results indicate a significant role for endogenous IL-1 in host defense against experimental M. paratuberculosis infection in mice.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Íleon/microbiología , Hígado/microbiología , Mycobacterium avium subsp. paratuberculosis/crecimiento & desarrollo , Paratuberculosis/inmunología , Receptores de Interleucina-1/inmunología , Animales , Granuloma/fisiopatología , Granuloma/prevención & control , Ratones , Ratones Endogámicos BALB C , Mycobacterium avium subsp. paratuberculosis/efectos de los fármacos , Mycobacterium avium subsp. paratuberculosis/aislamiento & purificación , Paratuberculosis/prevención & control , Prednisolona/farmacología
14.
Curr Opin Drug Discov Devel ; 2(2): 96-109, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19649935

RESUMEN

Protein serine/threonine kinases figure prominently among the molecular targets currently being pursued by the pharmaceutical industry. Given the conserved tertiary structure and catalytic mechanism of the mammalian kinase superfamily, it is not surprising that the discovery of selective inhibitors has proven to be difficult. However, in the last two years, progress has accelerated and approaches that target the ATP binding site and antisense RNA have matured to the point of advancing compounds into clinical trials. The development of a structural basis for understanding the selectivity of the pyridinylimidazole class of p38 MAP kinase inhibitors has been a major advance in this area.

15.
J Med Chem ; 31(7): 1355-9, 1988 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2898532

RESUMEN

A series of cis- and trans-4-carboxy-3,4,5,6-tetrahydropyrimidin-2(1H)-ones possessing either a carboxy, hydroxymethyl, or mercaptomethyl substituent at C-6 were prepared and tested for their ability to inhibit mammalian dihydroorotase. Of these compounds, only the cis-6-mercaptomethyl compound, cis-1, was found to be a potent competitive inhibitor of the enzyme (Ki = 140 nM at pH 7.4 and 8.5) when assayed in the direction of dihydro-L-orotate hydrolysis. These results suggest that the inhibition arises from the ligation of the thiolate to the zinc atom which is thought to be located in the enzyme's active site. Although analysis of cis-1 with 2,2'-dithiobis(5-nitrobenzoic acid) revealed significant loss of the free thiol group under enzymatic assay conditions, the addition of the reducing agent, dithiothreitol, to the enzymatic reaction mixtures afforded cis-1 complete protection against this chemical decomposition, as evidenced by lowering of the inhibition constant in the presence of dithiothreitol. Compound cis-1 had no significant antiproliferative activity against B16 melanoma cells in tissue culture, possibly due to the rapid decomposition of the compound or poor permeability into cells.


Asunto(s)
Amidohidrolasas/antagonistas & inhibidores , Dihidroorotasa/antagonistas & inhibidores , Pirimidinonas/farmacología , Animales , Unión Competitiva , División Celular/efectos de los fármacos , Línea Celular Transformada , Fenómenos Químicos , Química , Cricetinae , Ditiotreitol/farmacología , Melanoma/patología , Ratones , Pirimidinonas/síntesis química , Relación Estructura-Actividad , Compuestos de Sulfhidrilo , Células Tumorales Cultivadas
16.
J Med Chem ; 35(1): 100-6, 1992 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-1732516

RESUMEN

A series of side chain modified analogues of cholesterol and lanosterol (1-10) have been synthesized and evaluated as inhibitors of the Candida albicans delta 24-sterol methyltransferase. Two sterol substrate analogues 1 and 2 which contained a 24-thia substituent were relatively modest inhibitors of the enzyme (Ki = 1.5-72 microM). Compounds which mimic the carbocation intermediates proposed for the methyltransferase reaction, including sulfonium salts 4-6, amidines 7 and 8, and imidazoles 9 and 10 were substantially more potent inhibitors (Ki = 5-500 nM). All of the sterol analogues examined displayed less than 10-fold selectivity for inhibition of the methyltransferase versus the rat liver delta 24-sterol reductase. The sterol analogues were tested for in vitro antifungal activity against C. albicans, Candida tropicalis, and Torulopsis glabrata. The minimum inhibitory concentrations versus C. albicans correlated well with the Ki values for methyltransferase inhibition, and the potency of several compounds approached that of amphotericin B, although only modest fungicidal activity was observed.


Asunto(s)
Antifúngicos/síntesis química , Colesterol/análogos & derivados , Lanosterol/análogos & derivados , Metiltransferasas/antagonistas & inhibidores , Antifúngicos/farmacología , Candida albicans/efectos de los fármacos , Candida albicans/enzimología , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Pruebas de Sensibilidad Microbiana , Relación Estructura-Actividad
17.
J Med Chem ; 39(26): 5035-46, 1996 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-8978834

RESUMEN

A series of N-hydroxyurea derivatives have been prepared and examined as inhibitors of 5-lipoxygenase. Oral activity was established by examining the inhibition of LTB4 biosynthesis in an ex vivo assay in the mouse. The pharmacodynamic performance in the mouse of selected compounds was assessed using an ex vivo LTB4 assay and an adoptive peritoneal anaphylaxis assay at extended pretreat times. Compounds with an extended duration of action were re-examined as the individual enantiomers in the ex vivo assay, and the (S) enantiomer of N-hydroxy-N-[2,3-dihydro-6-(phenylmethoxy)-3-benzofuranyl]urea, (+)-1a (SB 202235), was selected as the compound with the best overall profile. Higher plasma concentrations and longer plasma half-lives were found for (+)-1a relative to its enantiomer in the mouse, monkey, and dog. In vitro metabolic studies in mouse liver microsomes established enantiospecific glucuronidation as a likely mechanism for the observed differences between the enantiomers of 1a. Enantioselective glucuronidation favoring (-)-1a was also found in human liver microsomes.


Asunto(s)
Benzofuranos/farmacología , Inhibidores de la Lipooxigenasa , Inhibidores de la Lipooxigenasa/farmacología , Urea/análogos & derivados , Animales , Benzofuranos/química , Benzofuranos/farmacocinética , Cromatografía Líquida de Alta Presión , Perros , Humanos , Inhibidores de la Lipooxigenasa/química , Inhibidores de la Lipooxigenasa/farmacocinética , Macaca fascicularis , Espectroscopía de Resonancia Magnética , Masculino , Ratones , Estereoisomerismo , Urea/química , Urea/farmacocinética , Urea/farmacología
18.
J Med Chem ; 44(12): 2015-26, 2001 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-11384246

RESUMEN

5-Dialkylaminosulfonylisatins have been identified as potent, nonpeptide inhibitors of caspases 3 and 7. The most active compound within this series (34) inhibited caspases 3 and 7 in the 2-6 nM range and exhibited approximately 1000-fold selectivity for caspases 3 and 7 versus a panel of five other caspases (1, 2, 4, 6, and 8) and was at least 20-fold more selective versus caspase 9. Sequence alignments of the active site residues of the caspases strongly suggest that the basis of this selectivity is due to binding in the S2 subsite comprised of residues Tyr204, Trp206, and Phe256 which are unique to caspases 3 and 7. These compounds inhibit apoptosis in three cell-based models: human Jurkat T cells, human chondrocytes, and mouse bone marrow neutrophils.


Asunto(s)
Inhibidores de Caspasas , Inhibidores de Cisteína Proteinasa/síntesis química , Isatina/análogos & derivados , Isatina/síntesis química , Sulfonamidas/síntesis química , Animales , Antineoplásicos/síntesis química , Antineoplásicos/química , Antineoplásicos/toxicidad , Apoptosis/efectos de los fármacos , Caspasa 3 , Caspasa 7 , Línea Celular , Supervivencia Celular/efectos de los fármacos , Condrocitos/citología , Condrocitos/efectos de los fármacos , Inhibidores de Cisteína Proteinasa/química , Inhibidores de Cisteína Proteinasa/farmacología , Diseño de Fármacos , Humanos , Isatina/química , Isatina/farmacología , Células Jurkat , Cinética , Ratones , Modelos Moleculares , Conformación Molecular , Neutrófilos/citología , Neutrófilos/efectos de los fármacos , Neutrófilos/fisiología , Proteínas Recombinantes/antagonistas & inhibidores , Relación Estructura-Actividad , Sulfonamidas/química , Sulfonamidas/farmacología
19.
J Med Chem ; 39(20): 3929-37, 1996 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-8831759

RESUMEN

A series of 1-alkyl- or -aryl-4-aryl-5-pyridinylimidazoles (A) were prepared and tested for their ability to bind to a recently discovered protein kinase termed CSBP and to inhibit lipopolysaccharide (LPS)-stimulated TNF production in mice. The kinase, CSBP, appears to be involved in a signaling cascade initiated by a number of inflammatory stimuli and leading to the biosynthesis of the inflammatory cytokines IL-1 and TNF. Two related imidazole classes (B and C) had previously been reported to bind to CSBP and to inhibit LPS-stimulated human monocyte IL-1 and TNF production. The members of the earlier series exhibited varying degrees of potency as inhibitors of the enzymes of arachidonic acid metabolism, PGHS-1 and 5-LO. Several of the more potent CSBP ligands and TNF biosynthesis inhibitors among the present series of N-1-alkylated imidazoles (A) were tested as inhibitors of PGHS-1 and 5-LO and were found to be weak to inactive as inhibitors of these enzymes. One of the compounds, 9 (SB 210313) which lacked measureable activity as an inhibitor of the enzymes of arachidonate metabolism, and had good potency in the binding and in vivo TNF inhibition assays, was tested for antiarthritic activity in the AA rat model of arthritis. Compound 9 significantly reduced edema and increased bone mineral density in this model.


Asunto(s)
Antiinflamatorios no Esteroideos/síntesis química , Inhibidores de la Ciclooxigenasa , Citocinas/antagonistas & inhibidores , Imidazoles/síntesis química , Inhibidores de la Lipooxigenasa , Morfolinas/síntesis química , Animales , Araquidonato 5-Lipooxigenasa/metabolismo , Ácido Araquidónico/metabolismo , Artritis/tratamiento farmacológico , Densidad Ósea/efectos de los fármacos , Imidazoles/metabolismo , Imidazoles/farmacología , Ratones , Ratones Endogámicos BALB C , Estructura Molecular , Morfolinas/metabolismo , Morfolinas/farmacología , Prostaglandina-Endoperóxido Sintasas/metabolismo , Proteínas Quinasas/metabolismo , Ratas , Relación Estructura-Actividad , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Factor de Necrosis Tumoral alfa/biosíntesis
20.
Invest Ophthalmol Vis Sci ; 33(12): 3292-301, 1992 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1428704

RESUMEN

The effects of recombinant basic fibroblast growth factor (FGF), epidermal growth factor (EGF), and transforming growth factor-beta (TGF-beta) on migration of human and bovine corneal cells were determined using checkerboard analysis in Boyden chambers. EGF, FGF, and TGF-beta each stimulated high levels of chemotactic migration. Each growth factor, however, induced a different dose-response pattern. Migration stimulated by FGF reached a plateau at a concentration between 100 and 200 ng/ml for endothelial, epithelial, and stromal fibroblasts. By contrast, chemotactic responses to EGF peaked between 10 and 50 ng/ml, then decreased at higher concentrations. TGF-beta also stimulated a peak in migration in all three corneal cells, but the peak of migration occurred at an approximately 1000-fold lower concentration (1 pg/ml) than for EGF. Checkerboard analysis demonstrated that FGF and EGF, but not TGF-beta, stimulated chemokinesis of bovine, stromal, and endothelial cells. These results demonstrate that FGF, EGF, and TGF-beta induce migration in pure populations of bovine and human corneal cells and support the concept that these growth factors may play key roles in corneal wound healing by regulating migration of corneal cells.


Asunto(s)
Quimiotaxis/efectos de los fármacos , Córnea/citología , Factor de Crecimiento Epidérmico/farmacología , Factores de Crecimiento de Fibroblastos/farmacología , Factor de Crecimiento Transformador beta/farmacología , Animales , Bovinos , Movimiento Celular/efectos de los fármacos , Células Cultivadas , Córnea/efectos de los fármacos , Sustancia Propia/citología , Sustancia Propia/efectos de los fármacos , Endotelio Corneal/citología , Endotelio Corneal/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Humanos , Cicatrización de Heridas/efectos de los fármacos
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