12 research outputs found
Increased Na, K, Cl cotransporter and Na, K-ATPase activity of vascular tissue in two-kidney Goldblatt hypertension
The properties of the Na/K pump and Na, K, Cl cotransporter were studied in vascular tissue of two-kidney Goldblatt hypertensive rats. These transport systems were measured as ouabain-sensitive and bumetanide-sensitive 86Rb/K uptake in aortic rings, left ventricular muscle and soleus skeletal muscle fibers of control and hypertensive Sprague-Dawley rats. A dramatic increment in Na/K pump activity was observed in intact aortic rings from the hypertensive group. The same was true for the Na, K, Cl cotransporter. The transport parameters related to the left ventricular muscle and soleus skeletal muscle were not significantly altered in the hypertensive rats. Measurements of the catalytic isoforms of the Na+, K+-ATPase in the aortic rings indicated that both isoforms (α1 and α2) were elevated in the same proportion in the hypertensive rats. The results also indicate that the endothelium plays an important role in both transport systems: in the absence of endothelium, a much lower 86Rb/K u
Effect of Chronic Renal Failure on NaK-ATPase A1 and a2 mRNA Transcription in Rat Skeletal Muscle
Artículo de publicación ISIPrevious studies have suggested that an alteration in the expression
of the NaK-ATPase of muscle may be an important
determinant of enhanced insulin sensitivity in chronic renal failure.
Therefore, in the present studies we have examined the
effect of uremia on the NaK-ATPase a isoforms in skeletal
muscle, at the level of mRNA expression and enzymatic activity.
The activity of the sodium pump, as measured ouabain-sensitive
'Rb/K uptake in soleus muscle, revealed a reduction in
the activity in uremia, related to the increment in plasma creatinine
values. The decrement in 86Rb uptake by the rat soleus
muscle of experimental animals was associated with changes
on NaK-ATPase gene product. Northern analysis of mRNA
revealed isoform-specific regulation of Na,K-ATPase by uremia
in skeletal muscle: a decrease of - 50% in al subunit
Na,K-ATPase mRNA, as compared to controls. The decrement
in al mRNA correlates with the decreased activity of the
Na,K-ATPase in uremia, under basal conditions and with the
almost complete inhibition of the Na,K-ATPase, of uremic tissue
by a concentration of 10-' M ouabain. Although the activity
of the a2 isoform pump was not modified by uremia, the 3.4-kb
message for this enzyme was increased 2.2-fold; this discrepancy
is discussed. Altogether these findings demonstrate that
the defective extrarenal potassium handling in uremia is at
least dependent in the expression of a1 subunit of the
Na,K-ATPase
LPS regulates the expression of glucocorticoid receptor alpha and beta isoforms and induces a selective glucocorticoid resistance in vitro
Background: This study was aimed to evaluate the effect of LPS in glucocorticoid receptor (GR) isoforms expression on different cell lines and PBMC from healthy donors in vitro and glucocorticoid sensitivity of PBMC in vitro.
Methods: U-2 OS cell lines expressing GR isoforms, different cell lines (CEM, RAJI, K562 and HeLa) or PBMC from healthy donors, were cultured or not with LPS. The expression of GR alpha and GR beta was evaluated by Western blot. Glucocorticoid sensitivity was evaluated in PBMC treated with LPS, testing genes which are transactivated or transrepressed by glucocorticoid. For transactivated genes (MKP1, FKBP5) PBMC were treated with Dexamethasone 100 nM for 6 h. The mRNA expression was measured by RT-PCR. For transrepressed genes (IL-8, GM-CSF), PBMC were cultured in Dexamethasone 100 nM and LPS 10 mu g/ml for 6 h and protein expression was measure by ELISA.
Results: GR isoforms were induced in U-2 OS cells with a greater effect on GR alpha expression. Both isoforms were also induced in CEM cells with a tendency to a greater effect on GR beta. LPS induced only the expression of GR alpha in Raji and HeLa cells, and in PBMC, with no effect in K562 cells. LPS induced a loss of glucocorticoid inhibitory effect only on the secretion of GM-CSF.
Conclusion: LPS in vitro differentially modulates the expression of GR isoforms in a cell specific manner. In PBMC from healthy donors LPS induces an approximately two times increase in the expression of GR alpha and a loss of the glucocorticoid inhibitory effect on the secretion of GM-CSF, without affecting other glucocorticoid responses evaluated.FONDECYT
108-052
Increased expression of the glucocorticoid receptor β in infants with RSV bronchiolitis
OBJECTIVES: The majority of studies on glucocorticoid treatment in respiratory syncytial virus (RSV) bronchiolitis concluded that there are no beneficial effects. We hypothesized that RSV-infected patients may have an increased glucocorticoid receptor (GR) β expression, the isoform that is unable to bind cortisol and exert an antiinflammatory action. METHODS: By using real-time polymerase chain reaction, we studied the expression of α and β GR in the peripheral blood mononuclear cells obtained from 49 RSV-infected infants (<1 year of age) with severe (n = 29) and mild to moderate (n = 20) illness. In plasma, we analyzed the level of cortisol by radioimmunoassay and inflammatory cytokines interleukin (IL)-10, IL-6, tumor necrosis factor-α, IL-1β, IL-8, IL-12p70, IL-2, IL-4, IL-5, interferon-g, and IL-17 by cytometric beads assay. Statistical analysis was performed by nonparametric analysis of variance. RESULTS: We found a significant increase of β GR expression in patients with severe
Earlier immunomodulatory treatment is associated with better visual outcomes in a subset of patients with Vogt-Koyanagi-Harada disease
Artículo de publicación ISIPurpose: To evaluate clinical outcomes of first-line immunomodulatory therapy (IMT) and prednisone alone or late IMT in Vogt-Koyanagi-Harada disease.
Methods: Retrospective cohort study of 152 patients with Vogt-Koyanagi-Harada disease evaluated in a referral uveitis clinic in Chile from 1985 to 2011. Medical records of these patients were reviewed. Demographic data, clinical evaluation, type of treatment, functional outcomes, glucocorticoid (GC) dose and complications were recorded. Multivariate logistic regression was used to identify prognostic factors of poor response to GC.
Results: There were no significant differences between first-line IMT group and prednisone alone/late IMT group in terms of visual acuity (VA) improvement, complications and GC sparing effect. There was a trend for a higher frequency of systemic adverse effects leading to discontinuation of treatment in patients receiving IMT than in those receiving prednisone (14.6% and 6.5%, respectively). The subgroup of patients with poor response to GC who showed functional improvement had a significantly earlier time to IMT initiation than the patients who had no improvement. We identified following prognostic factors of poor response to GC: VA <= 20/200, fundus depigmentation, chronic disease and tinnitus at diagnosis. Patients with a prognostic factor (excluding tinnitus) and VA improvement had an earlier IMT initiation than those who had worse functional outcome.
Conclusion: There were no differences in outcomes between first-line IMT and prednisone alone/late IMT in the entire VKH group. However, in a subset of patients, there was a significant better functional outcome with earlier IMT initiation
A consensus of the chilean nephrology and rheumatology societies on renal involvement in systemic lupus erythematosus Recomendaciones sobre el manejo del compromiso renal del lupus eritematoso sistémico. documento de consenso de las sociedades chilenas de
© 2015, Sociedad Medica de Santiago. All rights reserved. Renal involvement affects over one half of patients with Systemic Lupus Erythematosus increasing their mortality and morbidity, including chronic renal disease and the need of renal replacement therapies. Aiming to achieve a consensus in the most relevant topics on diagnosis, therapy and follow-up of patients with lupus renal disease, the Chilean Societies of Nephrology and Rheumatology constituted a workgroup that, based on a critical review of the available literature and their experience, raised and answered by consensus a set of relevant questions. This document includes aspects related to the clinical diagnosis, the importance of a suitable histological classification, therapeutic alternatives to induce and maintain disease remission, strategies for follow-up, additional therapies and ginecological-obstetric issues
Tofacitinib, un inhibidor oral de la quinasa Janus, para el tratamiento de artritis reumatoide en pacientes de Latinoamérica: eficacia y seguridad de estudios fase 3 y de extensión a largo plazo
Objective: Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA). We assessed tofacitinib efficacy and safety in the Latin American (LA) subpopulation of global Phase 3 and long-term extension (LTE) studies.
Materials and methods: Data from LA patients with RA and inadequate response to disease modifying antirheumatic drugs (DMARDs) were pooled across five Phase 3 studies. Phase 3 patients received tofacitinib 5 or 10 mg twice daily (BID), adalimumab or placebo; patients in the single LTE study received tofacitinib 5 or 10 mg BID; treatments were administered alone or with conventional synthetic DMARDs. Efficacy was reported up to 12 months (Phase 3) and 36 months (LTE) by American College of Rheumatology (ACR) 20/50/70 response rates, Disease Activity Score (DAS)28-4(erythrocyte sedimentation rate [ESR]) and Health Assessment Questionnaire-Disability Index (HAQ-DI). Incidence rates (IRs; patients with event/100 patient-years) of adverse events (AEs) of special interest were reported.
Results: The Phase 3 studies randomized 496 LA patients; the LTE study enrolled 756 LA patients from Phase 2 and Phase 3. In the Phase 3 studies, patients who received tofacitinib 5 and 10 mg BID showed improvements vs placebo at Month 3 in ACR20 (68.9% and 75.7% vs 35.6%), ACR50 (45.8% and 49.7% vs 20.7%) and ACR70 (17.5% and 23.1% vs 6.9%) responses, mean change from baseline in HAQ-DI (-0.6 and -0.8 vs -0.3) and DAS28-4(ESR) score (-2.3 and -2.4 vs -1.4). The improvements were sustained up to Month 36 in the LTE study. In the Phase 3 studies, IRs with tofacitinib 5 and 10 mg BID and placebo were 7.99, 6.57 and 9.84, respectively, for SAES, and 3.87, 5.28 and 3.26 for discontinuation due to AEs. IRs of AEs of special interest in tofacitinib-treated LA patients were similar to the global population.
Conclusion: In Phase 3 and LTE studies in LA patients with RA, tofacitinib demonstrated efficacy up to 36 months with a manageable safety profile up to 60 months, consistent with the overall tofacitinib study population.Objetivo: Tofacitinib es un inhibidor oral de la quinasa Janus para el tratamiento de la artritis reumatoide
(AR). Este análisis evaluó la eficacia y la seguridad de tofacitinib en la subpoblación Latinoamericana (LA)
de los estudios fase 3 y de extensión a largo plazo (ELP).
Materiales y métodos: Se agruparon datos de pacientes de Latinoamérica con AR y una respuesta inadecuada
a agentes modificadores de la enfermedad (DMARD) de 5 estudios fase 3. Los pacientes en estos
estudios recibieron tofacitinib 5 o 10 mg/2 veces al día (bid), adalimumab o placebo; los pacientes en el
estudio de seguridad recibieron tofacitinib 5 o 10 mg/bid; los tratamientos se administraron en monoterapia
o con DMARD sintéticos convencionales. La eficacia se reporta hasta 12 (fase 3) y 36 meses (ELP)
mediante las tasas de respuesta del Colegio Americano de Reumatología (ACR) 20/50/70, el índice de
actividad de la enfermedad (DAS)28-4 ESR (tasa de sedimentación globular [ESR]) y el índice de discapacidad
del cuestionario de evaluación de la salud (HAQ-DI). Se reportan las tasas de incidencia (IR:
pacientes con evento/100 pacientes/a˜no) de eventos adversos (EA) de interés especial.
Resultados: Los estudios fase 3, incluyeron 496 pacientes de LA, el ELP reclutó 756 pacientes de fase 2 y
fase 3. En los estudios de fase 3, los pacientes que recibieron tofacitinib 5 y 10 mg/bid presentaron mejorías
vs placebo al mes 3 en las respuestas ACR20 (68,9% y 75,7% vs 35,6%), ACR50 (45,8% y 49,7% vs 20,7%) y
ACR70 (17,5% y 23,1% vs 6,9%), en cambio, desde el valor basal en el escore HAQ-DI (−0,6 y
−0,8 vs
−0,3) y
en el escore DAS28-4(ESR) (−2,3 y
−2,4 vs
−1,4); estas mejorías fueron sostenidas hasta el mes 36, último
mes de evaluación en el estudio de ELP. En los pacientes con tofacitinib 5 o 10 mg/bid y placebo, las tasas
de incidencia de SAE fueron de 7,99, 6,57 y 9,84, mientras que la incidencia de descontinuaciones por EA
fueron de 3,87, 5,28 y 3,26, respectivamente. Las IR de EA de interés especial en pacientes de LA fueron
similares a la población global.
Conclusión: En los pacientes de LA con AR de estudios fase 3 y ELP, tofacitinib demostró eficacia hasta por
36 meses con un perfil de seguridad manejable hasta por 60 meses, en los pacientes de LA con AR, datos
consistentes con el de la población global de los estudios de tofacitinib.Pfizer Inc