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1.
Clin Exp Allergy ; 48(2): 186-195, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29121432

RESUMEN

BACKGROUND: Alpine climate treatment has historically been used in Europe to treat atopic dermatitis (AD), but no randomized trials have been conducted to provide evidence for its effectiveness. OBJECTIVE: To investigate the long-term effectiveness of alpine climate treatment for children with difficult to treat AD. MATERIALS & METHODS: A pragmatic, open, randomized controlled trial was conducted. Children diagnosed with AD that was considered difficult to treat, aged between 8 and 18 years and willing to be treated in Switzerland were randomized to a six-week personalized integrative multidisciplinary treatment period in a clinical setting in the alpine climate (Switzerland) or an outpatient setting in moderate maritime climate (Netherlands). Study assessments were conducted at the Wilhelmina Children's Hospital; an electronic portal was used for the collection of questionnaire data. Primary outcomes were disease activity (SAEASI), quality of life (CDLQI) and catastrophizing thoughts (JUCKKI/JU) 6 months after intervention. Other assessments were immediately and 6 weeks after intervention. Subgroup analyses concerned asthma-related outcomes. Children were randomly assigned to either the intervention or control group using a covariate adaptive randomization method, taking age and asthma diagnosis into account. Children, parents and healthcare professionals involved in treatment were not blinded to group assignment. Data were analysed according to intention-to-treat with linear mixed-effects models for continuous outcomes. The trial is registered at Current Controlled Trials ISCRTN88136485. RESULTS: Between 14 September 2010 and 30 September 2014, 88 children were enrolled in the trial, 84 children were randomized (41 assigned to intervention, 43 to control) of whom 77 completed the intervention (38 of 41 (93%) intervention, 39 of 43 (91%) control) and 74 completed follow-up (38 of 41 (93%) intervention, 36 of 43 (84%) control). Six months after intervention there were no significant differences between the groups on disease activity (SAEASI mean difference -3.4 (95%CI -8.5 to 1.7)), quality of life (CDLQI mean difference -0.3 (95%CI -2.0 to 1.4)) and catastrophizing thoughts (JUCCKI/JU subscale mean difference -0.7 (95%CI -1.4 to -0.0)). Immediately and 6 weeks after intervention, disease activity and quality of life were significantly different in favour of alpine climate treatment. Mean differences on SAEASI were -10.1 (95%CI -14.5 to -5.8) and -8.4 (95%CI -12.2 to -4.6) and on CDLQI -1.9 (95%CI -3.3 to -0.5) and -1.5 (95%CI -2.8 to -0.3) immediately and 6 weeks after the intervention, respectively. There were no long-term differences on asthma-related outcomes. Five serious adverse events occurred during the study period, which were not thought to be related to the treatment. CONCLUSIONS & CLINICAL RELEVANCE: For children with difficult to treat AD, there was no additional long-term benefit of alpine climate treatment, in contrast to the short-term, compared to an outpatient treatment programme in moderate maritime climate, using a personalized integrative multidisciplinary treatment approach.


Asunto(s)
Clima , Climatoterapia , Dermatitis Atópica/terapia , Adolescente , Altitud , Antiasmáticos/farmacología , Antiasmáticos/uso terapéutico , Niño , Dermatitis Atópica/diagnóstico , Dermatitis Atópica/epidemiología , Resistencia a Medicamentos , Humanos , Calidad de Vida , Encuestas y Cuestionarios , Suiza , Resultado del Tratamiento
2.
Org Biomol Chem ; 16(1): 62-69, 2017 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-29098212

RESUMEN

3,7-Dihydroxytropolones (3,7-dHTs) are highly oxygenated troponoids that have been identified as lead compounds for several human diseases. To date, structure-function studies on these molecules have been limited due to a scarcity of synthetic methods for their preparation. New synthetic strategies towards structurally novel 3,7-dHTs would be valuable in further studying their therapeutic potential. Here we describe the successful adaptation of a [5 + 2] oxidopyrilium cycloaddition/ring-opening for 3,7-dHT synthesis, which we apply in the synthesis of a plausible biosynthetic intermediate to the natural products puberulic and puberulonic acid. We have also tested these new compounds in several biological assays related to human immunodeficiency virus (HIV), hepatitis B virus (HBV) and herpes simplex virus (HSV) in order to gain insight into structure-functional analysis related to antiviral troponoid development.


Asunto(s)
Antivirales/farmacología , VIH/efectos de los fármacos , Virus de la Hepatitis B/efectos de los fármacos , Simplexvirus/efectos de los fármacos , Tropolona/análogos & derivados , Antivirales/síntesis química , Antivirales/química , Relación Dosis-Respuesta a Droga , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Relación Estructura-Actividad , Tropolona/síntesis química , Tropolona/química , Tropolona/farmacología
3.
Anaesthesist ; 64(6): 451-5, 2015 Jun.
Artículo en Alemán | MEDLINE | ID: mdl-26031561

RESUMEN

Sudden cardiac death (SCD) in young athletes during physical stress is a rare event with an incidence of 1-3 deaths per 100,000 athletes per year. A coronary anomaly is the second most common cause of death following hypertrophic cardiomyopathy. Symptomatic prodromes occur in 20% of cases prior to the SCD event. This case report describes a 35-year-old male who collapsed near the finishing line of a half marathon run. Despite immediate resuscitation attempts and initial return of spontaneous circulation (ROSC), a pulseless electrical activity (PEA) followed and the patient died 1 h after arrival in the resuscitation unit. The autopsy revealed an anomalous left coronary artery (ALCA), which can lead to ischemia of the respective heart muscles under severe stress.


Asunto(s)
Anomalías de los Vasos Coronarios/complicaciones , Muerte Súbita Cardíaca/patología , Carrera , Adulto , Autopsia , Reanimación Cardiopulmonar , Anomalías de los Vasos Coronarios/patología , Vasos Coronarios/patología , Muerte Súbita Cardíaca/etiología , Electrocardiografía , Humanos , Masculino , Miocardio/patología , Resistencia Física
4.
Anal Biochem ; 437(2): 138-43, 2013 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-23481912

RESUMEN

Cannabinoid (CB) receptors are being targeted therapeutically for the treatment of anxiety, obesity, movement disorders, glaucoma, and pain. More recently, cannabinoid agonists have displayed antiproliferative activity against breast cancer and prostate cancer in animal models. To study cannabinoid receptor ligands, we have developed a novel plate-based assay that measures internalization of CB1/CB2 receptors by determining the change in the intracellular levels of the radiolabeled agonists: [(3)H]Win55-212-2 for CB1 and [(3)H]CP55-940 for CB2. The developed plate-based assay was validated by determining IC50 values for known antagonists: AM251, AM281, AM630, and AM6545. The data obtained were consistent with previously reported values, thereby confirming that the assay can be used to determine the functional binding activities (IC50) of antagonists for the CB1 and CB2 receptors. In addition, we demonstrated that the plate-based assay may be used for screening against complex matrices. Specifically, we demonstrated that the plate-based assay was able to identify which extracts of several species of the genus Zanthoxylum had activity at the CB1/CB2 receptors.


Asunto(s)
Antagonistas de Receptores de Cannabinoides/farmacología , Receptor Cannabinoide CB1/metabolismo , Receptor Cannabinoide CB2/metabolismo , Animales , Células CHO , Cricetinae , Cricetulus , Humanos , Concentración 50 Inhibidora , Ligandos , Estructura Molecular , Extractos Vegetales/química , Extractos Vegetales/farmacología , Reproducibilidad de los Resultados , Zanthoxylum/química
5.
Neth J Med ; 78(4): 191-195, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32641558

RESUMEN

Monoclonal gammopathy of undetermined significance (MGUS) is considered an asymptomatic precursor of malignant lymphoid disorders. This case series and literature review shows that these monoclonal gammopathies can cause significant morbidity. We describe a patient with angioedema due to acquired C1-esterase inhibitor deficiency, a patient with cryoglobulinemia type II causing skin vasculitis and glomerulonephritis, and a patient with glomerulonephritis and nephrotic syndrome - all caused by a monoclonal gammopathy that can be classified as MGUS. Clinicians should be familiar with these consequences of monoclonal gammopathies. The term MGUS should only be used in patients without organ damage caused by monoclonal gammopathies.


Asunto(s)
Angioedemas Hereditarios/etiología , Crioglobulinemia/etiología , Enfermedades Renales/etiología , Paraproteinemias/complicaciones , Paraproteinemias/patología , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino
6.
Ned Tijdschr Geneeskd ; 150(23): 1303-6, 2006 Jun 10.
Artículo en Holandés | MEDLINE | ID: mdl-16821456

RESUMEN

A 12-year-old girl and a 57-year-old woman were admitted with fever, general malaise, abdominal pain, nausea and vomiting. Both patients had acute renal insufficiency based on tubulointerstitial nephritis caused by the genus Hantavirus, which was confirmed by blood tests. Both patients recovered spontaneously. The neighbouring countries of France, Germany and Belgium have recently reported 2- to 7-fold increases in the number of Hantavirus infections. Hantavirus is a zoonotic viral disease that is transmitted by mice and is found in humans worldwide. Infection with Hantavirus is associated with severe renal impairment and thrombocytopenia, which usually resolves spontaneously. Recognition of the clinical signs and targeted serological testing can lead to adequate management of the disease. Diagnosing patients with Hantavirus infections will also help to prevent infections in The Netherlands and track epidemiological changes.


Asunto(s)
Infecciones por Hantavirus/epidemiología , Dolor Abdominal/virología , Bélgica/epidemiología , Niño , Femenino , Francia/epidemiología , Alemania/epidemiología , Infecciones por Hantavirus/diagnóstico , Infecciones por Hantavirus/transmisión , Humanos , Incidencia , Persona de Mediana Edad , Países Bajos/epidemiología , Insuficiencia Renal/virología
7.
Diabetes Care ; 24(2): 323-7, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11213886

RESUMEN

OBJECTIVE: Cellular fibronectin is an endothelium-derived protein involved in subendothelial matrix assembly. Elevated plasma levels of cellular fibronectin therefore reflect loss of endothelial cell polarization or injury to blood vessels. Consequently, elevated plasma levels of circulating cellular fibronectin have been described in clinical syndromes with vascular damage, although not in diabetes or atherosclerosis. RESEARCH DESIGN AND METHODS: We determined fibronectin levels in 52 patients with type 1 diabetes, 50 patients with type 2 diabetes, 54 patients with a history of ischemic stroke, 23 patients with renal artery stenosis, and 64 healthy subjects. RESULTS: Circulating cellular fibronectin was significantly elevated in patients with diabetes (4.3 +/- 2.8 microg/ml) compared with patients with ischemic stroke (2.0 +/- 0.9 microg/ml), patients with renovascular hypertension (1.7 +/- 1.1 microg/ml), and healthy subjects (1.4 +/- 0.6 microg/ml). Patients with diabetes and at least one cardiovascular risk factor had an almost 2.5-fold increase in cellular fibronectin compared with diabetic subjects without such a risk factor. In multivariate regression analysis, higher triglycerides, current or past cigarette smoking, and higher urinary albumin excretion were independently associated with an increase in circulating cellular fibronectin in diabetes. CONCLUSIONS: These results suggest that circulating cellular fibronectin may be a marker protein for endothelial cell activation, especially in diabetes. Prospective studies are needed to explore this possibility


Asunto(s)
Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 2/sangre , Fibronectinas/sangre , Adulto , Anciano , Albuminuria/sangre , Enfermedades Cardiovasculares/sangre , Endotelio Vascular/metabolismo , Femenino , Humanos , Hipertensión Renovascular/sangre , Masculino , Persona de Mediana Edad , Análisis de Regresión , Factores de Riesgo , Fumar , Accidente Cerebrovascular/sangre , Triglicéridos/sangre
8.
Cardiovasc Res ; 40(2): 402-9, 1998 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9893735

RESUMEN

OBJECTIVE: Nitric oxide is a vasodilating and blood pressure lowering substance. To investigate whether calcium antagonists or angiotensin-converting enzyme (ACE) inhibitors increase vascular nitric oxide activity, we assessed systemic and renal vascular sensitivity to nitric oxide synthase inhibition in hypertensives on and off medication. METHODS: Ten essential hypertensive patients, aged 22-51 years, were studied 3 times: > or = 4 weeks off medication, after 3 weeks treatment with enalapril 20 mg twice a day and after 3 weeks nifedipine 60 mg/day. Each time, 24-h blood pressure registration was performed, followed by a clearance study to obtain a 3-h dose-response curve for intravenously infused NG-monomethyl-L-arginine (L-NMMA, respectively 0.75, 1.5 and 3.0 mg/kg/h). RESULTS: L-NMMA dose-dependently increased mean arterial pressure with 5 +/- 2 mmHg and systemic vascular resistance with 24 +/- 5% at maximum dose, whereas cardiac output decreased (all P < 0.001). Enalapril and nifedipine treatment decreased blood pressure, while the L-NMMA-induced increase in systemic vascular resistance was potentiated (enalapril: 45 +/- 7% and nifedipine: 46 +/- 8%; both P < 0.01). L-NMMA also dose-dependently decreased renal blood flow by 58 +/- 8% at maximum dose (P < 0.001), but neither drug potentiated these effects. CONCLUSION: These results indicate that, in essential hypertensives, antihypertensive therapy with enalapril or nifedipine increases nitric oxide dependency of systemic vascular tone, which may play a role in the blood pressure lowering effect of these drugs. However, this phenomenon cannot be observed in the renal circulation, suggesting a different regulation of endothelium-dependent vasomotion in the hypertensive kidney.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Bloqueadores de los Canales de Calcio/uso terapéutico , Enalapril/uso terapéutico , Hipertensión/sangre , Nifedipino/uso terapéutico , Óxido Nítrico/metabolismo , Adulto , Gasto Cardíaco/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Hipertensión/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Óxido Nítrico Sintasa/antagonistas & inhibidores , Circulación Renal/efectos de los fármacos , Resistencia Vascular/efectos de los fármacos , omega-N-Metilarginina/farmacología
9.
FEBS Lett ; 431(1): 85-90, 1998 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-9684871

RESUMEN

Aqueous extracts of the New Zealand sponge Adocia sp. (Haplosclerida) displayed potent anticytopathic activity in CEM-SS cells infected with HIV-1. Protein fractions of the extract bound both to the viral coat protein gp120 and to the cellular receptor CD4, but not to other tested proteins. The purified active protein, named adociavirin, was characterized by isoelectric focusing, amino acid analysis, MALDI-TOF mass spectrometry and N-terminal sequencing. Adociavirin, a disulfide-linked homodimer with a native molecular weight of 37 kDa, was active against diverse strains and isolates of HIV-1, as well as HIV-2, with EC50 values ranging from 0.4 nM to > 400 nM. The anti-HIV potency of adociavirin appears dependent on host cell type, with macrophage cultures being the most sensitive and peripheral blood lymphocytes the most resistant.


Asunto(s)
Fármacos Anti-VIH/aislamiento & purificación , VIH-1/efectos de los fármacos , Poríferos/química , Proteínas/aislamiento & purificación , Secuencia de Aminoácidos , Animales , Fármacos Anti-VIH/metabolismo , Fármacos Anti-VIH/farmacología , Antígenos CD4/metabolismo , Fusión Celular/efectos de los fármacos , Línea Celular , Efecto Citopatogénico Viral , Proteína gp120 de Envoltorio del VIH/metabolismo , Datos de Secuencia Molecular , Proteínas/metabolismo , Proteínas/fisiología
10.
J Hypertens ; 16(1): 45-50, 1998 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9533416

RESUMEN

OBJECTIVE: To assess whether increased shedding of adhesion molecules in plasma provides an index for endothelial damage in hypertension. DESIGN AND METHODS: Three groups of hypertensive patients with increasing severity of vascular damage were studied: 20 essential hypertensives, 21 atherosclerotic, renovascular hypertensives and four malignant hypertensives. Twenty healthy subjects were included as a control group. Levels of P-selectin, E-selectin, intracellular adhesion molecule 1, vascular cell adhesion molecule and von Willebrand factor in venous blood were measured, using sandwich-type enzyme-linked immunosorbent assay. RESULTS: For essential hypertensives a trend for increased P-selectin and E-selectin values compared with those in controls was observed (159+/-44 versus 132+/-40 ng/ml, P = 0.062 and 40+/-13 versus 34+/-17 ng/ml, P = 0.055, respectively). P-selectin (210+/-84 ng/ml, P = 0.0021) and E-selectin (42+/-12 ng/ml, P = 0.012) levels in renovascular hypertensives were significantly higher than those in healthy controls. There were no significant increases in circulating levels of intracellular adhesion molecule 1, vascular cell adhesion molecule and von Willebrand factor either in essential hypertensives or in renovascular hypertensives. Marked increases in circulating levels of adhesion molecules and von Willebrand factor relative to those in controls were observed in malignant hypertensives (P-selectin 634+/-332 versus 132+/-40 ng/ml, P = 0.0004; vascular cell adhesion molecule 968+/-187 versus 493+/-139 ng/ml, P = 0.0004; and von Willebrand factor 259+/-75 versus 130+/-72 U/dl, P = 0.016). CONCLUSIONS: Progression of vascular damage in essential, renovascular and malignant hypertension is associated with a rise in circulating levels of P-selectins and, to a lesser extent, E-selectins, whereas levels of intracellular adhesion molecule 1, vascular cell adhesion molecule and von Willebrand factor are elevated only in diseases associated with acute severe vascular damage, including malignant hypertension. Our data suggest that selectins may be useful as indicators of vascular damage in hypertension.


Asunto(s)
Endotelio Vascular/patología , Hipertensión/sangre , Hipertensión/patología , Selectina-P/sangre , Adulto , Anciano , Arteriosclerosis/sangre , Biomarcadores/sangre , Estudios de Casos y Controles , Selectina E/sangre , Endotelio Vascular/fisiopatología , Femenino , Humanos , Hipertensión/fisiopatología , Hipertensión Maligna/sangre , Hipertensión Renovascular/sangre , Molécula 1 de Adhesión Intercelular/sangre , Masculino , Persona de Mediana Edad , Molécula 1 de Adhesión Celular Vascular/sangre , Factor de von Willebrand/metabolismo
11.
J Med Chem ; 41(13): 2333-8, 1998 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-9632366

RESUMEN

A series of 79 flavones related to centaureidin (3,6,4'-trimethoxy-5, 7,3'-trihydroxyflavone, 1) was screened for cytotoxicity in the NCI in vitro 60-cell line human tumor screen. The resulting cytotoxicity profiles of these flavones were compared for degree of similarity to the profile of 1. Selected compounds were further evaluated with in vitro assays of tubulin polymerization and [3H]colchicine binding to tubulin. Maximum potencies for tubulin interaction and production of differential cytotoxicity profiles characteristic of 1 were observed only with compounds containing hydroxyl substituents at C-3' and C-5 and methoxyl groups at C-3 and C-4'.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Flavonoides/farmacología , Tubulina (Proteína)/metabolismo , Biopolímeros , Supervivencia Celular/efectos de los fármacos , Colchicina/metabolismo , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Unión Proteica/efectos de los fármacos , Relación Estructura-Actividad , Tubulina (Proteína)/química , Células Tumorales Cultivadas
12.
J Med Chem ; 35(11): 1978-86, 1992 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-1597853

RESUMEN

Extracts of Homalanthus nutans, a plant used in Samoan herbal medicine, exhibited potent activity in an in vitro, tetrazolium-based assay which detects the inhibition of the cytopathic effects of human immunodeficiency virus (HIV-1). The active constituent was identified as prostratin, a relatively polar 12-deoxyphorbol ester. Noncytotoxic concentrations of prostratin from greater than or equal to 0.1 to greater than 25 microM protected T-lymphoblastoid CEM-SS and C-8166 cells from the killing effects of HIV-1. Cytoprotective concentrations of prostratin greater than or equal to 1 microM essentially stopped virus reproduction in these cell lines, as well as in the human monocytic cell line U937 and in freshly isolated human monocyte/macrophage cultures. Prostratin bound to and activated protein kinase C in vitro in CEM-SS cells and elicited other biochemical effects typical of phorbol esters in C3H10T1/2 cells; however, the compound does not appear to be a tumor promoter. In skin of CD-1 mice, high doses of prostratin induced ornithine decarboxylase only to 25-30% of the levels induced by typical phorbol esters at doses 1/30 or less than that used for prostratin, produced kinetics of edema formation characteristic of the nonpromoting 12-deoxyphorbol 13-phenylacetate, and failed to induce the acute or chronic hyperplasias typically caused by tumor-promoting phorbols at doses of 1/100 or less than that used for prostratin.


Asunto(s)
VIH-1/efectos de los fármacos , Ésteres del Forbol/aislamiento & purificación , Plantas Medicinales/química , Animales , Línea Celular , Supervivencia Celular/efectos de los fármacos , Efecto Citopatogénico Viral/efectos de los fármacos , Edema/inducido químicamente , Humanos , Hiperplasia , Estado Independiente de Samoa , Espectroscopía de Resonancia Magnética , Ratones , Monocitos/efectos de los fármacos , Monocitos/microbiología , Ornitina Descarboxilasa/biosíntesis , Ésteres del Forbol/química , Ésteres del Forbol/farmacología , Proteína Quinasa C/metabolismo , Piel/efectos de los fármacos , Piel/enzimología , Piel/patología , Linfocitos T/efectos de los fármacos , Linfocitos T/microbiología , Replicación Viral/efectos de los fármacos
13.
J Nucl Med ; 41(8): 1337-42, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10945524

RESUMEN

UNLABELLED: Preliminary data suggest that aspirin renography is more sensitive than captopril renography for indicating renal artery stenosis (RAS). Considering that aspirin, compared with captopril, reduces renal blood flow and, thus, tubular tracer delivery in poststenotic kidneys, aspirin renography is expected to be more useful, particularly if tubular tracers are used. METHODS: We prospectively compared aspirin renography (20 mg/kg orally) and captopril renography (25 mg orally) with 99mTc-mercaptoacetyltriglycine in 75 consecutive patients suspected of having RAS. RESULTS: RAS, diagnosed as stenosis of more than 50% on angiography, was found unilaterally in 34 patients and bilaterally in 17 patients. RAS was absent in 24 patients. The sensitivities for unilateral RAS or bilateral RAS (i.e., stenosis that was at least unilateral) were, respectively, 88% and 88% for captopril renography and 82% and 94% for aspirin renography (not significant). The overall specificity was 75% for captopril renography and 83% for aspirin renography (not significant). Tracer uptake ratios, time to peak activity, and percentage of 20-min tracer retention were also not significantly different for captopril and aspirin renography. Subgroup analysis of modest (50-75%) and severe (> or =75%) RAS, or of plasma creatinine greater than 120 micromol/L, also showed no difference between captopril and aspirin renography. CONCLUSION: We conclude that for identification of RAS, the usefulness of aspirin renography equals, but does not surpass, that of captopril renography.


Asunto(s)
Aspirina , Captopril , Renografía por Radioisótopo/métodos , Radiofármacos , Obstrucción de la Arteria Renal/diagnóstico por imagen , Tecnecio Tc 99m Mertiatida , Anciano , Inhibidores de la Enzima Convertidora de Angiotensina , Femenino , Humanos , Masculino , Persona de Mediana Edad , Inhibidores de Agregación Plaquetaria , Radiofármacos/farmacocinética , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Tecnecio Tc 99m Mertiatida/farmacocinética
14.
J Biomol Screen ; 5(3): 169-76, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10894760

RESUMEN

The unique, high-affinity binding of cyanovirin-N (CV-N), a potent anti-human immunodeficiency virus (HIV) protein, to the HIV envelope glycoprotein gp120, was exploited to develop an HTS assay in an attempt to discover small-molecule mimetics of CV-N. A competition binding assay was developed using CV-N labeled with europium (Eu(3+)). The labeling protocol did not significantly alter the gp120 binding properties or the antiviral activity of CV-N. This report describes the assay development, validation, and results of screening a large library of aqueous and organic natural product extracts. The extracts were incubated with immobilized recombinant gp120 in 96-well plates prior to the addition of Eu(3+)-labeled CV-N. Following a wash step, bound CV-N was measured by dissociation-enhanced time-resolved fluorometry of Eu(3+). The assay proved to be robust, rapid, and reproducible, and was used to screen over 50,000 natural product extracts, and has resulted in the identification of several aqueous natural product extracts that inhibited CV-N-gp120 binding and also had anti-HIV activity.


Asunto(s)
Fármacos Anti-VIH/metabolismo , Proteínas Bacterianas , Factores Biológicos/metabolismo , Proteínas Portadoras/metabolismo , Proteína gp120 de Envoltorio del VIH/metabolismo , VIH-1/metabolismo , Espectrometría de Fluorescencia/métodos , Unión Competitiva , Línea Celular , Ensayo de Inmunoadsorción Enzimática , Humanos , Unión Proteica , Proteínas Recombinantes/metabolismo
15.
Brain Res ; 330(1): 135-40, 1985 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-2985189

RESUMEN

Experiments were undertaken to determine the site of action of securinine and related convulsant indolizidines. All of these compounds induced tonic seizures in mice, with CD50 values ranging from 11 to 87 mg/kg. The CD50 for bicuculline was found to be 8 mg/kg. Equilibrium binding assays revealed that securinine and dihydrosecurinine inhibit [3H]GABA binding to rat brain membranes with an IC50 of approximately 50 microM, which is some 7 times less potent than bicuculline. Allosecurinine and virosecurinine have IC50 values greater than 1 mM. Both dihydrosecurinine and securinine inhibited GABA-stimulated benzodiazepine binding in rat brain membranes, though they were somewhat weaker than bicuculline in this respect. Other binding assays revealed that securinine and its analogs were inactive as inhibitors of bicuculline-insensitive GABA binding, benzodiazepine, cholinergic muscarinic, and beta-adrenergic receptor binding. In addition, while thiocyanate ion increased the apparent binding potency of bicuculline 10-fold, it had little effect on that of securinine. Extracellular electrophysiological studies on neurons in the cat spinal cord indicated that securinine and dihydrosecurinine blocked the inhibitory action of GABA while having no effect on that of glycine. Allo- and virosecurinine were much less active as GABA receptor antagonists in this test. These results suggest that, like bicuculline, securinine and dihydrosecurinine are selective antagonists of GABA recognition sites on mammalian central neurons.


Asunto(s)
Alcaloides/farmacología , Azepinas , Sistema Nervioso Central/efectos de los fármacos , Convulsivantes , Lactonas , Piperidinas , Receptores de GABA-A/efectos de los fármacos , Animales , Bicuculina/farmacología , Gatos , Femenino , Compuestos Heterocíclicos de 4 o más Anillos , Compuestos Heterocíclicos de Anillo en Puente , Ratones , Ratones Endogámicos ICR , Convulsiones/inducido químicamente , Estimulación Química
16.
Phytochemistry ; 55(3): 233-6, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11142848

RESUMEN

Three cytotoxic clerodane diterpene esters, corymbulosins A-C, were isolated from an organic extract of the fruit of Laetia corymbulosa (Flacourtiaceae) from Peru. The structures were determined by spectroscopic methods as clerodane diterpenes unsaturated at C-3, C-13(16) and C-14. Corymbulosin A was esterified at C-2 with a decadienoate moiety, while corymbulosins B and C were C-2 epimers esterified at C-6 with a decanoate moiety.


Asunto(s)
Antineoplásicos Fitogénicos/química , Diterpenos/química , Ésteres/química , Rosales/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Antineoplásicos Fitogénicos/farmacología , Diterpenos/aislamiento & purificación , Diterpenos/farmacología , Ésteres/aislamiento & purificación , Ésteres/farmacología , Humanos , Células Tumorales Cultivadas
17.
Clin Chim Acta ; 199(2): 195-204, 1991 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-1873917

RESUMEN

Angiotensin has an intrarenal action which may not parallel its action in the general circulation. We investigated whether the urinary excretion rates of angiotensin I and II (UV-AI, UV-AII) can be used as a marker of renal production. We therefore measured UV-AI, UV-AII, plasma angiotensin I and II (PAI, PAII), and plasma renin activity (PRA) in healthy subjects under conditions influencing the renin-angiotensin system: captopril injection (n = 7), enalapril treatment (n = 9), furosemide infusion on high and low sodium intake (n = 6), indomethacin treatment (n = 8), and head-out water immersion (three sodium intakes). After captopril (acute) and enalapril (chronic), PAI and PRA increased, PAII decreased, but neither UV-AI nor UV-AII changed. During furosemide infusion, PAI, PAII, PRA, as well as UV-AI and UV-AII increased. During indomethacin treatment, PAI, PAII, and PRA decreased, whereas UV-AI and UV-AII did not change consistently. Sodium restriction increased PAI, PAII, and PRA, but did not alter UV-AI and UV-AII. Head-out immersion decreased PAI, PAII, and PRA, but did not change UV-AI and UV-AII. The relative constancy of the urinary AI and AII excretion rates makes it doubtful whether urinary angiotensins reflect changes of renal angiotensin production.


Asunto(s)
Angiotensina II/orina , Angiotensina I/orina , Sistema Renina-Angiotensina/fisiología , Adulto , Angiotensina I/sangre , Angiotensina II/sangre , Captopril/farmacología , Enalapril/farmacología , Femenino , Furosemida/farmacología , Humanos , Inmersión/fisiopatología , Indometacina/farmacología , Masculino , Renina/sangre , Sistema Renina-Angiotensina/efectos de los fármacos , Sodio en la Dieta/administración & dosificación
18.
J Nephrol ; 16(6): 807-12, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-14736007

RESUMEN

BACKGROUND: Atherosclerotic renal artery stenosis (ARAS) is associated with progressive loss of renal function and is one of the most important causes of renal failure in the elderly. Current treatment includes restoration of the renal arterial lumen by endovascular stent placement. However, this treatment only affects damage caused by ARAS due to the stenosis and ensuing post-stenotic ischemia. ARAS patients have severe general vascular disease. Atherosclerosis and hypertension can also damage the kidney parenchyma causing renal failure. Medical treatment focuses on the latter. Lipid-lowering drugs (statins) could reduce renal failure progression and could reduce the overall high cardiovascular risk. The additional effect on preserving renal function of stent placement as compared to medical therapy alone is unknown. Therefore, the STAR-study aims to compare the effects of renal artery stent placement together with medication vs. medication alone on renal function in ARAS patients. METHOD: Patients with an ARAS of > or = 50% and renal failure (creatinine (Cr) clearance < 80 mL/min/1.73 m2) are randomly assigned to stent placement with medication or to medication alone. Medication consists of statins, anti-hypertensive drugs and antiplatelet therapy. Patients are followed for 2 yrs with extended follow-up to 5 yrs. The primary outcome of this study is a reduction in Cr clearance > 20% compared to baseline. This trial will include 140 patients.


Asunto(s)
Antihipertensivos/uso terapéutico , Arteriosclerosis/terapia , Ácidos Heptanoicos/uso terapéutico , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Pirroles/uso terapéutico , Obstrucción de la Arteria Renal/terapia , Arteria Renal , Stents , Angioplastia de Balón , Arteriosclerosis/complicaciones , Arteriosclerosis/fisiopatología , Atorvastatina , Terapia Combinada , Progresión de la Enfermedad , Humanos , Riñón/fisiopatología , Obstrucción de la Arteria Renal/etiología , Obstrucción de la Arteria Renal/fisiopatología , Proyectos de Investigación
19.
Nucl Med Commun ; 22(9): 971-4, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11505205

RESUMEN

BACKGROUND: Captopril renography (CR) has been shown to improve the effectiveness of renal scintigraphy in renovascular hypertension, by inhibiting angiotensin-converting enzyme. CR is particularly sensitive and specific in unilateral renal artery stenosis (RAS), but results in patients with bilateral RAS are less favourable. The aim of this study was to investigate the meaning of abnormal but identical renographic curves in the diagnosis of RAS. PATIENTS AND METHODS: One hundred and fifty-eight patients clinically suspected for renovascular hypertension underwent CR, using 50 MBq (99)Tc(m)-mercaptoacetyltriglycine ((99)Tc(m)-MAG(3)), prior to performing renal angiography. CR was performed 1 h after captopril administration. Renograms were analysed according to the consensus criteria. All patients underwent angiography, considered as the "gold standard" in the detection of the presence of RAS (stenosis >50% was defined as significant). All kidneys were categorized into three groups, scintigraphically as well as angiographically: no stenosis, unilateral stenosis and bilateral stenosis. RESULTS: Out of 158 patients 100 (63%) showed a RAS on angiography (58 (37%) unilateral, 42 (26%) bilateral). The sensitivity and specificity of CR evaluated by patient was 83% and 75%, respectively. Thirty patients with completely identical curves were identified, 21 patients with normal curves and nine patients with abnormal identical curves. All but one patient showed no RAS on the angiogram. In this single patient a unilateral stenosis was found. CONCLUSION: Identical curves on the renogram generally suggest no RAS and are probably due to intrinsic parenchymal disease.


Asunto(s)
Captopril , Renografía por Radioisótopo , Obstrucción de la Arteria Renal/diagnóstico por imagen , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad
20.
J Forensic Sci ; 24(4): 808-13, 1979 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-541644

RESUMEN

Pyrolysis gas chromatography coupled with infrared identification of eluted peaks confirms that paraquat is pyrolyzed into chloromethane and 4,4'-dipyridyl at smoking temperatures and above. This reaction occurs at 610 degrees C to completion in small amounts in an inert atmosphere. The toxicity of 4,4'-dipyridyl remains to be determined. Pyrolysis of contaminated marijuana also produces the same two products, although detection at low limits is difficult with this procedure.


Asunto(s)
Cannabis/análisis , Paraquat/análisis , 2,2'-Dipiridil/análisis , Cromatografía de Gases , Calor , Análisis Espectral
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