Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 415
Filtrar
Más filtros

Base de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Am J Physiol Cell Physiol ; 303(3): C236-43, 2012 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-22538238

RESUMEN

Ca(2+) signals are commonly measured using fluorescent Ca(2+) indicators and microscopy techniques, but manual analysis of Ca(2+) measurements is time consuming and subject to bias. Automated region of interest (ROI) detection algorithms have been employed for identification of Ca(2+) signals in one-dimensional line scan images, but currently there is no process to integrate acquisition and analysis of ROIs within two-dimensional time lapse image sequences. Therefore we devised a novel algorithm for rapid ROI identification and measurement based on the analysis of best-fit ellipses assigned to signals within noise-filtered image sequences. This algorithm was implemented as a plugin for ImageJ software (National Institutes of Health, Bethesda, MD). We evaluated the ability of our algorithm to detect synthetic Gaussian signal pulses embedded in background noise. The algorithm placed ROIs very near to the center of a range of signal pulses, resulting in mean signal amplitude measurements of 99.06 ± 4.11% of true amplitude values. As a practical application, we evaluated both agonist-induced Ca(2+) responses in cultured endothelial cell monolayers, and subtle basal endothelial Ca(2+) dynamics in opened artery preparations. Our algorithm enabled comprehensive measurement of individual and localized cellular responses within cultured cell monolayers. It also accurately identified characteristic Ca(2+) transients, or Ca(2+) pulsars, within the endothelium of intact mouse mesenteric arteries and revealed the distribution of this basal Ca(2+) signal modality to be non-Gaussian with respect to amplitude, duration, and spatial spread. We propose that large-scale statistical evaluations made possible by our algorithm will lead to a more efficient and complete characterization of physiologic Ca(2+)-dependent signaling.


Asunto(s)
Señalización del Calcio , Procesamiento de Imagen Asistido por Computador/métodos , Algoritmos , Animales , Células Cultivadas , Endotelio Vascular/metabolismo , Arterias Mesentéricas/metabolismo , Ratones , Programas Informáticos
2.
Rheumatology (Oxford) ; 47(7): 976-9, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18499715

RESUMEN

OBJECTIVES: To evaluate the analytical performance of an ELISA for the detection of anti-RNA polymerase III antibody (ARA) and to assess IIF as a method for identifying this antibody. METHODS: A commercially available ELISA was used to assess the presence of ARA in sera from 1018 SSc patients. The sera had been divided into sub-populations based on the presence of specific autoantibodies, ANA pattern or the absence of both. Patients with ARA (n = 209) had been identified by characteristic ANA pattern by IIF on HEp-2 cell substrate [and additionally by radio-immunoprecipitation (IP) in 157/209 cases]. The remaining 809 SSc patients acted as a control group. RESULTS: Of 157 patients in whom ARA had been confirmed by IP, 150 were positive by ELISA providing a sensitivity of 96%. In the group where ARA had only been assessed by IIF, 100% (52/52) were ELISA positive. The ANA patterns indicating the presence of ARA were a fine-speckled nucleoplasmic stain with additional occasional bright dots, with or without concurrent punctate nucleolar staining. In the SSc control group, the ELISA attained a specificity of 98%, ARA being detected in 17/809 patients. CONCLUSIONS: We report the outcome of a study on a large population of SSc patients that shows the ARA ELISA to be of high analytical sensitivity and specificity. We confirm that there is minimal overlap between ARA and other SSc-specific autoantibodies. Additionally, it is demonstrated that the presence of ARA correlates with identifiable patterns by IIF on HEp-2 cell substrate.


Asunto(s)
Anticuerpos Antinucleares/sangre , ARN Polimerasa III/inmunología , Esclerodermia Sistémica/inmunología , Ensayo de Inmunoadsorción Enzimática/métodos , Técnica del Anticuerpo Fluorescente Indirecta/métodos , Humanos , Sensibilidad y Especificidad
3.
Toxicology ; 245(1-2): 130-40, 2008 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-18243465

RESUMEN

Chloral hydrate (CH) is a short-lived intermediate in the metabolism of trichloroethylene (TRI). TRI, CH, and two common metabolites, trichloroacetic acid (TCA) and dichloroacetic acid (DCA) have been shown to be hepatocarcinogenic in mice. To better understand the pharmacokinetics of these metabolites of TRI in humans, eight male volunteers, aged 24-39, were administered single doses of 500 or 1,500 mg or a series of three doses of 500 mg given at 48 h intervals, in three separate experiments. Blood and urine were collected over a 7-day period and CH, DCA, TCA, free trichloroethanol (f-TCE), and total trichloroethanol (T-TCE=trichloroethanol and trichloroethanol-glucuronide [TCE-G]) were measured. DCA was detected in blood and urine only in trace quantities (<2 microM). TCA, on the other hand, had the highest plasma concentration and the largest AUC of any metabolite. The TCA elimination curve displayed an unusual concentration-time profile that contained three distinct compartments within the 7-day follow-up period. Previous work in rats has shown that the complex elimination curve for TCA results largely from the enterohepatic circulation of TCE-G and its subsequent conversion to TCA. As a result TCA had a very long residence time and this, in turn, led to a substantial enhancement of peak concentrations following the third dose in the multiple dose experiment. Approximately 59% of the AUC of plasma TCA following CH administration is produced via the enterohepatic circulation of TCE-G. The AUC for f-TCE was found to be positively correlated with serum bilirubin concentrations. This effect was greatest in one subject that was found to have serum bilirubin concentrations at the upper limit of the normal range in all three experiments. The AUC of f-TCE in the plasma of this individual was consistently about twice that of the other seven subjects. The kinetics of the other metabolites of CH was not significantly modified in this individual. These data indicate that individuals with a more impaired capacity for glucuronidation may be very sensitive to the central nervous system depressant effects of high doses of CH, which are commonly attributed to plasma levels of f-TCE.


Asunto(s)
Hidrato de Cloral/metabolismo , Hidrato de Cloral/farmacocinética , Hígado/metabolismo , Adulto , Hidrato de Cloral/sangre , Hidrato de Cloral/orina , Ácido Dicloroacético/sangre , Ácido Dicloroacético/metabolismo , Ácido Dicloroacético/orina , Etilenclorhidrina/análogos & derivados , Etilenclorhidrina/sangre , Etilenclorhidrina/metabolismo , Etilenclorhidrina/orina , Glucuronatos/sangre , Glucuronatos/metabolismo , Glucuronatos/orina , Humanos , Masculino , Persona de Mediana Edad , Factores de Tiempo , Ácido Tricloroacético/sangre , Ácido Tricloroacético/metabolismo , Ácido Tricloroacético/orina
4.
Bioorg Med Chem Lett ; 17(24): 6707-13, 2007 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-17977724

RESUMEN

The cis-3-amino-4-(2-cyanopyrrolidide)-pyrrolidine template has been shown to afford low nanomolar inhibitors of human DPP-IV that exhibit a robust PK/PD profile. An X-ray co-crystal structure of 5 confirmed the proposed mode of binding. The potent single digit DPP-IV inhibitor 53 exhibited a preferred PK/PD profile in preclinical animal models and was selected for additional profiling.


Asunto(s)
Benceno/química , Cianuros/química , Inhibidores de la Dipeptidil-Peptidasa IV , Inhibidores de Proteasas/síntesis química , Inhibidores de Proteasas/farmacología , Pirroles/química , Pirroles/farmacología , Aminación , Animales , Dipeptidil Peptidasa 4/química , Dipeptidil Peptidasa 4/metabolismo , Perros , Diseño de Fármacos , Humanos , Concentración 50 Inhibidora , Modelos Moleculares , Estructura Molecular , Inhibidores de Proteasas/química , Ratas , Estereoisomerismo , Relación Estructura-Actividad
5.
J Endocrinol ; 191(1): 93-100, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17065392

RESUMEN

Glucose-dependent insulinotrophic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are important enteroendocrine hormones that are rapidly degraded by an ubiquitous enzyme dipeptidyl peptidase IV to yield truncated metabolites GIP(3-42) and GLP-1(9-36)amide. In this study, we investigated the effects of sub-chronic exposure to these major circulating forms of GIP and GLP-1 on blood glucose control and endocrine pancreatic function in obese diabetic (ob/ob) mice. A once daily injection of either peptide for 14 days had no effect on body weight, food intake or pancreatic insulin content or islet morphology. GLP-1(9-36)amide also had no effect on plasma glucose homeostasis or insulin secretion. Mice receiving GIP(3-42) exhibited small but significant improvements in non-fasting plasma glucose, glucose tolerance and glycaemic response to feeding. Accordingly, plasma insulin responses were unchanged suggesting that the observed enhancement of insulin sensitivity was responsible for the improvement in glycaemic control. These data indicate that sub-chronic exposure to GIP and GLP-1 metabolites does not result in physiological impairment of insulin secretion or blood glucose control. GIP(3-42) might exert an overall beneficial effect by improving insulin sensitivity through extrapancreatic action.


Asunto(s)
Glucemia/metabolismo , Diabetes Mellitus/metabolismo , Polipéptido Inhibidor Gástrico/farmacología , Péptido 1 Similar al Glucagón/análogos & derivados , Insulina/metabolismo , Obesidad/metabolismo , Fragmentos de Péptidos/farmacología , Péptidos/farmacología , Receptores de la Hormona Gastrointestinal/antagonistas & inhibidores , Animales , Diabetes Mellitus/fisiopatología , Ingestión de Alimentos , Péptido 1 Similar al Glucagón/farmacología , Prueba de Tolerancia a la Glucosa , Homeostasis , Inmunohistoquímica/métodos , Insulina/análisis , Insulina/sangre , Resistencia a la Insulina , Secreción de Insulina , Células Secretoras de Insulina/química , Células Secretoras de Insulina/metabolismo , Islotes Pancreáticos/efectos de los fármacos , Islotes Pancreáticos/metabolismo , Islotes Pancreáticos/patología , Ratones , Ratones Obesos , Obesidad/fisiopatología , Tamaño de los Órganos/efectos de los fármacos
6.
Clin Neuropathol ; 25(4): 180-4, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16866299

RESUMEN

Central core disease (CCD) is mainly a disease of infancy and childhood and represents a member of a group of muscular disorders known as "congenital, benign (non-progressive) myopathies". It is an uncommon disease of infancy and early childhood, and presentation is rare in adulthood. The disease is mainly familial with an autosomal-dominant pattern of inheritance, yet sporadic cases can occur. The diagnosis is based on a muscle biopsy, which documents unique morphological abnormalities of focal loss of oxidative enzyme in type I muscular fibers. The basis for this loss of such activities is represented by a near-total absence of mitochondria and sarcoplasmic reticulum in the cores. We describe a 58-year-old man diagnosed with CCD, who is one of the oldest individuals reported with CCD diagnosed by a muscle biopsy. The clinical, pathological and genetic features of this rare entity are discussed herein.


Asunto(s)
Fibras Musculares Esqueléticas/patología , Músculo Esquelético/patología , Miopatía del Núcleo Central/patología , Adenosina Trifosfatasas/metabolismo , Edad de Inicio , Complejo IV de Transporte de Electrones/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Fibras Musculares Esqueléticas/enzimología , Fibras Musculares Esqueléticas/ultraestructura , Músculo Esquelético/enzimología , Músculo Esquelético/ultraestructura , Miopatía del Núcleo Central/genética , NAD/metabolismo , Canal Liberador de Calcio Receptor de Rianodina/genética , Succinato Deshidrogenasa/metabolismo
7.
J Appl Physiol (1985) ; 97(6): 2190-9, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15531572

RESUMEN

To determine the influence of experimental model and strain differences on the relationship of vascular permeability to inflammatory cytokine production after high peak inflation pressure (PIP) ventilation, we used isolated perfused mouse lung and intact mouse preparations of Balb/c and B6/129 mice ventilated at high and low PIP. Filtration coefficients in isolated lungs and bronchoalveolar lavage (BAL) albumin in intact mice increased within 20-30 min after initiation of high PIP in isolated Balb/c lungs and intact Balb/c, B6/129 wild-type, and p55 and p75 tumor necrosis factor (TNF) dual-receptor null mice. In contrast, the cytokine response was delayed and variable compared with the permeability response. In isolated Balb/c lungs ventilated with 25-27 cmH(2)O PIP, TNF-alpha, interleukin (IL)-1 beta, IL-1 alpha, macrophage inflammatory protein (MIP)-2, and IL-6 concentrations in perfusate were markedly increased in perfusate at 2 and 4 h, but only MIP-2 was detectable in intact Balb/c mice using the same PIP. In intact wild-type and TNF dual-receptor null mice with ventilation at 45 cmH(2)O PIP, the MIP-2 and IL-6 levels in BAL were significantly increased after 2 h in both groups, but there were no differences between groups in the BAL albumin and cytokine concentrations or in lung wet-to-dry weight ratios. TNF-alpha was not be detected in BAL fluids in any group of intact mice. These results suggest that the alveolar hyperpermeability induced by high PIP ventilation occurs very rapidly and is initially independent of TNF-alpha participation and unlikely to depend on MIP-2 or IL-6.


Asunto(s)
Citocinas/metabolismo , Alveolos Pulmonares/fisiopatología , Respiración Artificial/efectos adversos , Síndrome de Dificultad Respiratoria/fisiopatología , Enfermedad Aguda , Albúminas/metabolismo , Animales , Dióxido de Carbono/sangre , Quimiocina CXCL2 , Quimiocinas/metabolismo , Interleucina-1/metabolismo , Interleucina-6/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Microcirculación/fisiología , Microscopía Electrónica , Oxígeno/sangre , Alveolos Pulmonares/metabolismo , Alveolos Pulmonares/ultraestructura , Circulación Pulmonar/fisiología , Edema Pulmonar/etiología , Edema Pulmonar/metabolismo , Edema Pulmonar/fisiopatología , Receptores del Factor de Necrosis Tumoral/genética , Síndrome de Dificultad Respiratoria/etiología , Síndrome de Dificultad Respiratoria/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo
8.
J Endocrinol ; 175(2): 525-33, 2002 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-12429050

RESUMEN

The incretin hormone glucose-dependent insulinotropic polypeptide (GIP) is rapidly degraded in the circulation by dipeptidyl peptidase IV forming the N-terminally truncated peptide GIP(3-42). The present study examined the biological activity of this abundant circulating fragment peptide to establish its possible role in GIP action. Human GIP and GIP(3-42) were synthesised by Fmoc solid-phase peptide synthesis, purified by HPLC and characterised by electrospray ionisation-mass spectrometry. In GIP receptor-transfected Chinese hamster lung fibroblasts, GIP(3-42) dose dependently inhibited GIP-stimulated (10(-7) M) cAMP production (up to 75.4+/-5.4%; P<0.001). In BRIN-BD11 cells, GIP(3-42) was significantly less potent at stimulating insulin secretion (1.9- to 3.2-fold; P<0.001), compared with native GIP and significantly inhibited GIP-stimulated (10(-7) M) insulin secretion with maximal inhibition (48.8+/-6.2%; P<0.001) observed at 10(-7) M. In (ob/ob) mice, administration of GIP(3-42) significantly inhibited GIP-stimulated insulin release (2.1-fold decrease; P<0.001) and exaggerated the glycaemic excursion (1.4-fold; P<0.001) induced by a conjoint glucose load. These data indicate that the N-terminally truncated GIP(3-42) fragment acts as a GIP receptor antagonist, moderating the insulin secreting and metabolic actions of GIP in vivo.


Asunto(s)
Polipéptido Inhibidor Gástrico/metabolismo , Receptores de la Hormona Gastrointestinal/antagonistas & inhibidores , Animales , Glucemia/metabolismo , Células Cultivadas , Cricetinae , Cricetulus , Fibroblastos/metabolismo , Humanos , Insulina/metabolismo , Peso Molecular , Receptores de la Hormona Gastrointestinal/metabolismo , Transfección
9.
Am J Physiol Lung Cell Mol Physiol ; 283(6): L1203-9, 2002 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12388351

RESUMEN

The response of segmental filtration coefficients (Kf) to high peak inflation pressure (PIP) injury was determined in isolated perfused rat lungs. Total (K f,t ), arterial (K f,a ), and venous (K f,v ) filtration coefficients were measured under baseline conditions and after ventilation with 40-45 cmH(2)O PIP. K f,a and K f,v were measured under zone I conditions by increasing airway pressure to 25-27 cmH(2)O. The microvascular segment K f (K f,mv ) was then calculated by: K f,mv = K f,t - K f,a - K f,v. The baseline K f,t was 0.090 +/- 0.022 ml. min(-1). cm H2O(-1). 100 g(-1) and segmentally distributed 18% arterial, 41% venous, and 41% microvascular. After high PIP injury, K f,t increased by 680%, whereas K f,a, K f,v, and K f,mv increased by 398, 589, and 975%, respectively. Pretreatment with 50 microM gadolinium chloride prevented the high PIP-induced increase in K f in all vascular segments. These data imply a lower hydraulic conductance for microvascular endothelium due to its large surface area and a gadolinium-sensitive high-PIP injury, produced in both alveolar and extra-alveolar vessel segments.


Asunto(s)
Presión del Aire , Permeabilidad Capilar/fisiología , Pulmón/fisiología , Respiración Artificial , Animales , Hemodinámica , Técnicas In Vitro , Pulmón/anatomía & histología , Masculino , Tamaño de los Órganos , Circulación Pulmonar , Ratas , Ratas Endogámicas
10.
Diabetologia ; 45(9): 1281-91, 2002 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12242461

RESUMEN

AIMS/HYPOTHESIS: This study examined the plasma stability, biological activity and antidiabetic potential of two novel N-terminally modified analogues of gastric inhibitory polypeptide (GIP). METHODS: Degradation studies were carried out on GIP, N-acetyl-GIP (Ac-GIP) and N-pyroglutamyl-GIP (pGlu-GIP) in vitro following incubation with either dipeptidylpeptidase IV or human plasma. Cyclic adenosine 3'5' monophosphate (cAMP) production was assessed in Chinese hamster lung fibroblast cells transfected with the human GIP receptor. Insulin-releasing ability was assessed in vitro in BRIN-BD11 cells and in obese diabetic ( ob/ ob) mice. RESULTS: GIP was rapidly degraded by dipeptidylpeptidase IV and plasma (t(1/2) 2.3 and 6.2 h, respectively) whereas Ac-GIP and pGlu-GIP remained intact even after 24 h. Both Ac-GIP and pGlu-GIP were extremely potent ( p<0.001) at stimulating cAMP production (EC(50) values 1.9 and 2.7 nmol/l, respectively), almost a tenfold increase compared to native GIP (18.2 nmol/l). Both Ac-GIP and pGlu-GIP (10(-13)-10(-8) mmol/l) were more potent at stimulating insulin release compared to the native GIP ( p<0.001), with 1.3-fold and 1.2-fold increases observed at 10(-8) mol/l, respectively. Administration of GIP analogues (25 nmol/kg body weight, i.p.) together with glucose (18 mmol/kg) in ( ob/ ob) mice lowered ( p<0.001) individual glucose values at 60 min together with the areas under the curve for glucose compared to native GIP. This antihyperglycaemic effect was coupled to a raised ( p<0.001) and more prolonged insulin response after administration of Ac-GIP and pGlu-GIP (AUC, 644+/-54 and 576+/-51 ng.ml(-1) x min, respectively) compared with native GIP (AUC, 257+/-29 ng.ml(-1) x min). CONCLUSION/INTERPRETATION: Ac-GIP and pGlu-GIP, show resistance to plasma dipeptidylpeptidase IV degradation, resulting in enhanced biological activity and improved antidiabetic potential in vivo, raising the possibility of their use in therapy of Type II (non-insulin-dependent) diabetes mellitus.


Asunto(s)
Diabetes Mellitus Tipo 2/tratamiento farmacológico , Polipéptido Inhibidor Gástrico/farmacología , Hipoglucemiantes/farmacología , Insulina/metabolismo , Acetilación , Animales , Área Bajo la Curva , Biotransformación , Glucemia/efectos de los fármacos , Glucemia/metabolismo , Línea Celular , Cricetinae , Cricetulus , AMP Cíclico/metabolismo , Fibroblastos , Polipéptido Inhibidor Gástrico/síntesis química , Polipéptido Inhibidor Gástrico/química , Polipéptido Inhibidor Gástrico/farmacocinética , Ácido Glutámico , Humanos , Hipoglucemiantes/farmacocinética , Insulina/sangre , Secreción de Insulina , Pulmón , Ratones , Ratones Obesos , Receptores de la Hormona Gastrointestinal/genética , Receptores de la Hormona Gastrointestinal/fisiología , Proteínas Recombinantes/metabolismo , Relación Estructura-Actividad , Transfección
12.
Pharmacol Rev ; 53(2): 177-208, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11356983

RESUMEN

Metabolism of perchloroethylene (Perc) occurs by cytochrome P450-dependent oxidation and glutathione (GSH) conjugation. The cytochrome P450 pathway generates tri- and dichloroacetate as metabolites of Perc, and these are associated with hepatic toxicity and carcinogenicity. The GSH conjugation pathway is associated with generation of reactive metabolites selectively in the kidneys and with Perc-induced renal toxicity and carcinogenicity. Physiologically based pharmacokinetic models have been developed for Perc in rodents and in humans. We propose the addition of a submodel that incorporates the GSH conjugation pathway and the kidneys as a target organ. Long-term bioassays of Perc exposure in laboratory animals have identified liver tumors in male and female mice, kidney tumors in male rats, and mononuclear cell leukemia in male and female rats. Increases in incidence of non-Hodgkin's lymphoma and of cervical, esophageal, and urinary bladder cancer have been observed for workers exposed to Perc. Limited, and not always consistent, evidence is available concerning the kidneys as a target organ for Perc in humans. Three potential modes of action for Perc-induced liver tumorigenesis are: 1) modification of signaling pathways; 2) cytotoxicity, cell death, and reparative hyperplasia; and 3) direct DNA damage. Four potential modes of action for Perc-induced renal tumorigenesis are: 1) peroxisome proliferation, 2) alpha-2u-globulin nephropathy, 3) genotoxicity leading to somatic mutation, and 4) acute cytotoxicity and necrosis leading to cell proliferation. Finally, the epidemiological and experimental data are assessed and use of toxicity information in the development of a reference dose and a reference concentration for human Perc exposure are presented.


Asunto(s)
Riñón/efectos de los fármacos , Hígado/efectos de los fármacos , Solventes , Tetracloroetileno , Animales , Sistema Enzimático del Citocromo P-450/metabolismo , Femenino , Humanos , Masculino , Exposición Profesional , Solventes/metabolismo , Solventes/farmacocinética , Solventes/toxicidad , Tetracloroetileno/metabolismo , Tetracloroetileno/farmacocinética , Tetracloroetileno/toxicidad
13.
Arthritis Rheum ; 45(2): 122-8, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11324774

RESUMEN

OBJECTIVE: To examine the effects of stress management training on pain behavior exhibited by persons with rheumatoid arthritis (RA) and the relationship of change in pain behavior with certain patient characteristics as well as change in self-reported levels of pain. METHODS: Patients with RA (n = 131) were randomly assigned to 1 of 3 groups: a stress management group, an attention control group, or a standard care control group. The stress management and attention control groups received a 10-week intervention followed by a 15-month maintenance phase. RESULTS: The 3 groups did not differ significantly in the change in pain behavior at any of the assessment periods. However, persons with RA who had less disease activity tended to exhibit positive changes in pain behavior over time. Changes in self-reported pain were not significantly related to changes in pain behavior. CONCLUSION: The results indicate that stress management interventions do not reduce total pain behaviors exhibited by persons with RA. Changes in pain behaviors appear to be related to disease activity, age, and disease duration, but not to changes in self-reported measures of pain.


Asunto(s)
Artritis Reumatoide/terapia , Manejo del Dolor , Estrés Psicológico/prevención & control , Artritis Reumatoide/complicaciones , Artritis Reumatoide/fisiopatología , Artritis Reumatoide/psicología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dolor/fisiopatología , Dolor/psicología , Dimensión del Dolor , Índice de Severidad de la Enfermedad , Estrés Psicológico/etiología , Encuestas y Cuestionarios , Resultado del Tratamiento
14.
J Pharmacol Exp Ther ; 297(1): 155-64, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11259540

RESUMEN

Acute cytotoxicity (lactate dehydrogenase release) of trichloroethylene (TRI), S-(1,2-dichlorovinyl)glutathione (DCVG), and S-(1,2-dichlorovinyl)-L-cysteine (DCVC) in freshly isolated renal cortical cells and hepatocytes from male and female rats was evaluated to test the hypothesis that the assay provides a valid indicator of sex- and tissue-dependent differences in sensitivity to TRI and its metabolites. We then determined mitochondrial toxicity (inhibition of state-3 and/or stimulation of state-4 respiration) in renal cortical and hepatic mitochondria from male and female rats and mice to assess sex-, tissue-, and species-dependent susceptibility. TRI was moderately cytotoxic in renal cells from male rats but was nontoxic in renal cells from female rats or hepatocytes from male or female rats. Acute cytotoxicity of both DCVG and DCVC was greater in renal cells from male rats than in renal cells from female rats. Although DCVC does not target the liver in vivo, it was a very potent hepatotoxicant in vitro. Mitochondrial toxicity in kidney and liver showed similar patterns, with mitochondria from male rats being more sensitive than mitochondria from female rats; order of potency was DCVC > DCVG >> TRI. State-3 respiration in mitochondria from mice was also inhibited, but the patterns and relative sensitivities differed from those in mitochondria from rats. Renal and hepatic mitochondria from mice were less sensitive than corresponding mitochondria from rats and renal mitochondria from female mice were significantly more sensitive than renal mitochondria from male mice. Thus, many of the species-, sex-, and tissue-dependent differences in toxicity observed in vivo are also observed in vitro.


Asunto(s)
Glutatión/metabolismo , Riñón/efectos de los fármacos , Hígado/efectos de los fármacos , Tricloroetileno/toxicidad , Animales , Relación Dosis-Respuesta a Droga , Femenino , Riñón/metabolismo , Riñón/patología , L-Lactato Deshidrogenasa/metabolismo , Hígado/metabolismo , Hígado/patología , Masculino , Ratones , Mitocondrias/efectos de los fármacos , Especificidad de Órganos , Ratas , Ratas Endogámicas F344 , Factores Sexuales , Especificidad de la Especie , Tricloroetileno/metabolismo
15.
Neurosci Lett ; 302(1): 37-40, 2001 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-11278106

RESUMEN

Hypoxic-ischemic (HI) cerebral injury frequently follows resuscitation and is a recognized cause of permanent long-term neurologic disability in children. Complement activation has been shown to participate in post-ischemic injury to a variety of tissues and organs. To test the hypothesis that complement activation participates in post-HI cerebral injury in immature rats, 21-day-old rats were subjected to right common carotid artery ligation and 8% O(2). This combination of ischemia and hypoxia resulted in the development of significant neuronal loss, edema, and atrophy in the right cerebral hemisphere. However, intraperitoneal administration of the complement inhibitors soluble complement receptor type 1 or cobra venom factor did not reduce the neuronal loss, edema, or atrophy. Therefore, complement activation did not contribute significantly to the cerebral injury observed in this immature rat model.


Asunto(s)
Edema Encefálico/tratamiento farmacológico , Proteínas Inactivadoras de Complemento/uso terapéutico , Venenos Elapídicos/uso terapéutico , Hipoxia-Isquemia Encefálica/tratamiento farmacológico , Neuronas/efectos de los fármacos , Receptores de Complemento/uso terapéutico , Animales , Atrofia/tratamiento farmacológico , Atrofia/etiología , Edema Encefálico/etiología , Corteza Cerebral/patología , Hipoxia-Isquemia Encefálica/complicaciones , Ratas , Ratas Sprague-Dawley
16.
Toxicol Sci ; 60(1): 11-9, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11222868

RESUMEN

The metabolism of trichloroethylene (Tri) by cytochrome P450 (P450) was studied in microsomes from liver and kidney homogenates and from isolated renal proximal tubular (PT) and distal tubular (DT) cells from male Fischer 344 rats. Chloral hydrate (CH) was the only metabolite consistently detected and was used as a measurement of P450-dependent metabolism of Tri. Pretreatment of rats with pyridine increased CH formation in both liver and kidney microsomes, whereas pretreatment of rats with clofibrate increased CH formation only in kidney microsomes. Pyridine increased CYP2E1 expression in both liver and kidney microsomes, whereas clofibrate had no effect on hepatic but increased renal CYP2E1 and CYP2C11 protein levels. These results suggest a role for CYP2E1 in both the hepatic and renal metabolism of Tri and a role for CYP2C11 in the renal metabolism of Tri. Studies with the general P450 inhibitor SKF-525A and the CYP2E1 competitive substrate chlorzoxazone provided additional support for the role of CYP2E1 in both tissues. CH formation was higher in PT cells than in DT cells and was time and reduced nicotinamide adenine dinucleotide phosphate (NADPH) dependent. However, pretreatment of rats with either pyridine or clofibrate had no effect on CYP2E1 or CYP2C11 protein levels or on CH formation in isolated cells. These data show for the first time that Tri can be metabolized to at least one of its P450 metabolites in the kidneys and quantitate the effect of P450 induction on Tri metabolism in the rat kidney.


Asunto(s)
Sistema Enzimático del Citocromo P-450/biosíntesis , Túbulos Renales Distales/enzimología , Túbulos Renales Proximales/enzimología , Tricloroetileno/metabolismo , Animales , Western Blotting , Hidrato de Cloral/metabolismo , Clorzoxazona/farmacología , Clofibrato/farmacología , Inducción Enzimática , Técnicas In Vitro , Túbulos Renales Distales/efectos de los fármacos , Túbulos Renales Proximales/efectos de los fármacos , Masculino , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/enzimología , Proadifeno/farmacología , Piridinas/farmacología , Ratas , Ratas Endogámicas F344
17.
Diabetes ; 49(12): 2079-86, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11118010

RESUMEN

Peptidic glucagon antagonists have been shown to lower blood glucose levels in diabetic models (1-3), but attempts to identify small molecular weight glucagon receptor-binding antagonists have met with little success. Skyrin, a fungal bisanthroquinone, exhibits functional glucagon antagonism by uncoupling the glucagon receptor from adenylate cyclase activation in rat liver membranes (1). We have examined the effects of skyrin on cells transfected with the human glucagon receptor and on isolated rat and human hepatocytes. The skyrin used was isolated from Talaromyces wortmanni American Type Culture Collection 10517. In rat hepatocytes, skyrin (30 micromol/l) inhibited glucagon-stimulated cAMP production (53%) and glucose output (IC50 56 micromol/l). There was no detectable effect on epinephrine or glucagon-like peptide 1 (GLP-1) stimulation of these parameters, which demonstrates skyrin's selective activity. Skyrin was also evaluated in primary cultures of human hepatocytes. Unlike cell lines, which are largely unresponsive to glucagon, primary human hepatocytes exhibited glucagon-dependent cAMP production for 14 days in culture (EC50 10 nmol/l). Skyrin (10 micromol/l) markedly reduced glucagon-stimulated cAMP production (55%) and glycogenolysis (27%) in human hepatocytes. The inhibition of glucagon stimulation was a specific property displayed by skyrin and oxyskyrin but not shared by other bisanthroquinones. Skyrin is the first small molecular weight nonpeptidic agent demonstrated to interfere with the coupling of glucagon to adenylate cyclase independent of binding to the glucagon receptor. The data presented in this study indicate that functional uncoupling of the human glucagon receptor from cAMP production results in metabolic effects that could reduce hepatocyte glucose production and hence alleviate diabetic hyperglycemia.


Asunto(s)
Antraquinonas/farmacología , Glucagón/antagonistas & inhibidores , Hepatocitos/efectos de los fármacos , Animales , Células CHO , Células Cultivadas , Cricetinae , AMP Cíclico/antagonistas & inhibidores , AMP Cíclico/biosíntesis , Epinefrina/farmacología , Glucagón/farmacología , Péptido 1 Similar al Glucagón , Glucosa/metabolismo , Glucógeno/metabolismo , Humanos , Masculino , Fragmentos de Péptidos/farmacología , Precursores de Proteínas/farmacología , Ratas , Ratas Sprague-Dawley , Receptores de Glucagón/genética , Transfección
18.
J Appl Physiol (1985) ; 89(6): 2241-8, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11090574

RESUMEN

Alveolar overdistension due to high peak inflation pressures (PIP) is associated with an increased capillary filtration coefficient (K(fc)). To determine which signal pathways contribute to this injury, we perfused isolated rat lungs with 5% bovine albumin in Krebs solution and measured K(fc) after successive 30-min periods of ventilation with peak inflation pressures (PIP) of 7, 20, 30, and 35 cmH(2)O. In a high-PIP control group, K(fc) increased significantly after ventilation with 30 and 35 cmH(2)O PIP, but significant increases were prevented by treatment with 100 microM trifluoperazine, an inhibitor of Ca(2+)/calmodulin, 500 nM ML-7, an inhibitor of myosin light chain kinase (MLCK), a combination of isoproterenol (20 microM) and rolipram (10 microM) to enhance intracellular cAMP levels, and a dose of KT-5720 (2 microM), which inhibits MLCK and protein kinase C. These studies suggest that the Ca(2+)/calmodulin-MLCK pathway augments capillary fluid leak after a modest high-PIP injury and that this is attenuated by kinase inhibition and increased intracellular cAMP.


Asunto(s)
Inhibidores Enzimáticos/farmacología , Enfermedades Pulmonares/etiología , Enfermedades Pulmonares/fisiopatología , Quinasa de Cadena Ligera de Miosina/antagonistas & inhibidores , Inhibidores de Fosfodiesterasa/farmacología , Respiración Artificial/efectos adversos , Animales , Bloqueadores de los Canales de Calcio/farmacología , Calmodulina/antagonistas & inhibidores , Permeabilidad Capilar/efectos de los fármacos , AMP Cíclico/antagonistas & inhibidores , AMP Cíclico/metabolismo , Combinación de Medicamentos , Técnicas In Vitro , Isoproterenol/farmacología , Pulmón/patología , Masculino , Tamaño de los Órganos/efectos de los fármacos , Proteína Quinasa C/antagonistas & inhibidores , Circulación Pulmonar/efectos de los fármacos , Ratas , Ratas Endogámicas , Rolipram/farmacología , Trifluoperazina/farmacología
19.
Arthritis Care Res ; 13(1): 23-32, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11094923

RESUMEN

OBJECTIVE: To examine depressive disorders and health status in patients with rheumatoid arthritis (RA), controlling for potential confounds. METHOD: Subjects (n = 426) completed measures of depressive symptoms (Center for Epidemiological Studies Depression Scale [CES-D]) and health status (Arthritis Impact Measurement Scales 2 [AIMS2]), via cross-sectional survey. Subjects (n = 299) with few depressive symptoms (CES-D < or = 10) were not evaluated further. Subjects with CES-D > or = 11 were interviewed using the Primary Care Evaluation of Mental Disorders to diagnose major depressive disorder (MDD; n = 46), dysthymic disorder (DD; n = 21), or minor depressive disorder (MND; n = 18). RESULTS: Regression analyses examined differences between the depressive disorders on AIMS2 subscales. Health status scores were similar between the depressive disorder subcategories; significant differences were found between MDD and MND on AIMS2 Physical scores and MDD and DD on AIMS2 Symptom scores. CONCLUSION: Regarding health status, presence of depression itself seems to overshadow differences between depression subtypes; antidepressant treatments/referrals for persons with concomitant RA and any depressive disorder subtype appear warranted.


Asunto(s)
Artritis Reumatoide/complicaciones , Depresión/diagnóstico , Depresión/etiología , Trastorno Depresivo/diagnóstico , Trastorno Depresivo/etiología , Estado de Salud , Artritis Reumatoide/psicología , Sesgo , Factores de Confusión Epidemiológicos , Estudios Transversales , Depresión/clasificación , Trastorno Depresivo/clasificación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis de Regresión
20.
Lupus ; 9(7): 527-33, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11035419

RESUMEN

We tested mood states in patients with systemic lupus erythematosus (SLE) treated with the prolactin-lowering drug, bromocriptine. Bromocriptine was given to seven patients in an open-label study to test its effects on active SLE. Two independent measures of SLE activity, the SLE Activity Measure (SLAM) and the SLE Disease Activity Index (SLEDAI), were scored and the Symptom Questionnaire (SQ) mood survey was administered at entry and at 6 monthly follow-up visits. The SLAM and SLEDAI scores improved significantly during treatment. Two of the four mood scales in the SQ (Anxiety Scale and Anger-Hostility Scale) showed significant improvement compared to the entry value at least once during treatment. Significant improvement was also observed in the Total Distress Score, which is the sum of the four scales and is a more sensitive measure of distress than the score of an individual scale. Depression, anxiety, somatic complaints, and total distress correlated positively with SLAM and/or SLEDAI scores. The Anxiety Scale and the Total Distress Score improved with treatment and did correlate positively with SLE activity. In contrast, the Anger-Hostility Scale improved with treatment but did not correlate with SLE activity.


Asunto(s)
Afecto , Bromocriptina/uso terapéutico , Antagonistas de Hormonas/uso terapéutico , Lupus Eritematoso Sistémico/tratamiento farmacológico , Lupus Eritematoso Sistémico/psicología , Ira , Ansiedad , Depresión , Femenino , Estado de Salud , Humanos , Lupus Eritematoso Sistémico/fisiopatología , Masculino , Examen Físico , Prolactina/antagonistas & inhibidores , Prolactina/sangre , Escalas de Valoración Psiquiátrica , Encuestas y Cuestionarios
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA