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R Alcázar

Publications and source records attributed to R Alcázar.

30 records · Page 2Linked to original sources
PubMed1997

Prospective analysis of the factors influencing the antibody response to hepatitis B vaccine in hemodialysis patients.

Hepatitis B vaccine is effective in producing protection against hepatitis B virus (HBV) infection in hemodialysis (HD) patients, but the antibody response is variable. To identify those factors implicated in the vaccine response, in a prospective study over a 24-month period, we vaccinated 80 seronegative patients on HD (group A) and monitored clinical, biochemical, and immunologic parameters. The protective immunity acquired by vaccination was compared with that developed through HBV infection in 22 age-matched HD patients (group B). The anti-HBs antibody-seronegative patients followed a four-dose vaccination schedule (0, 1, 2, and 6 months) with 40 microg DNA-recombinant hepatitis B vaccine. One month after vaccination, 77.5% of the patients had seroconverted, and 72.5% achieved high antibody response, whereas 22.5% were nonresponders. Patients aged younger than 40 years seroconverted 100%; those aged 40 to 60 years, 75% (P < 0.01); and patients older than 60 years, 74% (P < 0.001). No differences between responders and nonresponders concerning sex, time on HD, HD dose, nutritional status, hemoglobin level, HD membrane, iPTH level, calcitriol treatment, or number of transfusions during vaccination were found. The presence of other factors, such as recombinant human erythropoietin (rHuEPO) therapy or hepatitis C virus (HCV) infection, did not significantly influence antibody responses to hepatitis B immunization. A greater frequency of DR3 (53.8% v 25.7%, P < 0.05), DR7 (53.8% v 18.6%, P < 0.01), and DQ2 (76.9% v 44.1%, P < 0.05), and a lesser frequency of A2 (7.7% v 37.2%, P < 0.05) were found in nonresponders compared with responders. Eighteen months after vaccination, the analysis showed similar antibody titers but lower seroconversion rates in group A as compared with group B. In conclusion, unresponsiveness to hepatitis B vaccine in HD patients was related to factors such as older age, the presence of DR3, DR7, and DQ2, and the absence of A2 alleles. Although the seroprotection produced by the vaccine was less than that achieved through natural HBV infection, our protocol of vaccination was sufficiently immunogenic and provided lasting protection.

Adult↗
PubMed1995

Involvement of tumor necrosis factor-alpha in the pathogenesis of experimental and human glomerulonephritis.

The evidence supporting a role for TNF-alpha in glomerular diseases can be summarized with the following: TNF-alpha can be secreted in the kidney by intrinsic renal cells and infiltrating phagocytes, as has been shown in vitro and in vivo during glomerular injury. TNF-alpha has proinflammatory actions which include cell death, chemotactic properties, and modulation of secretion of other inflammatory mediators, and extracellular matrix (Fig 5). Administration of exogenous TNF-alpha or agents that induce release of endogenous TNF alpha, such as endotoxin, increase the severity of experimental glomerular injury. Furthermore, the blockade of TNF-alpha action with specific antibodies, soluble receptors, or inhibitors improves the outcome of glomerulonephritis. Finally, several of the agents currently in use for the therapy of glomerular injury, such as corticosteroids and cyclosporine, are known to modulate the production of TNF-alpha. Specific TNF-alpha antagonists or inhibitors may have a role in the management of glomerulonephritis in the future.

Animals↗
PubMed1995

[The reversibility of pulmonary hypertension associated with autoimmune hyperthyroidism].

We report the case of a 28-year-old woman in a chronic hemodialysis program, who developed moderate pulmonary hypertension (eco-Doppler assumed pulmonary systolic pressure of 62 mmHg), with right ventricular dilatation (49 mm) in coincidence with a fully symptomatic autoimmune hyperthyroidism. The improvement of thyroid function resulted in a significant regression of pulmonary hypertension (45 mmHg) and normalization of right ventricular size (35 mm). The appearance and reversibility of pulmonary hypertension associated to autoimmune hyperthyroidism have not been described before and, in our patient, it is probably facilitated by other coincident factors that increase cardiac output and, subsequently, pulmonary flow, i.e. anemia and the arteriovenous fístula for hemodialysis.

Adult↗
PubMed1994

Choice of dialysis membrane does not influence the outcome of residual renal function in haemodialysis patients.

It has been recently proposed that haemodialysis membrane choice may influence the maintenance of residual renal function. The aim of the present study was to prospectively analyse the effect of membrane choice on the outcome of renal function in patients entering a chronic haemodialysis programme. Twenty-two patients from four hospitals have been randomly assigned to be dialysed with either polysulphone (PSF)/polyacrylonitrile (PAN) (group A; n = 9), or cuprophane membranes (group B; n = 13). Basal and monthly serum biochemistry, residual creatinine clearance (Ccr) and urine volume (Vu), pharmacological and dialytic treatment, diet, and haemodialysis-related complications were recorded. A significant decrease was observed in the two most relevant variables, i.e. remnant Ccr and Vu, within 3 months of starting haemodialysis, with stabilization during the further follow-up. Such decrease was similar (P NS) for both groups A and B throughout the 9-month observation period. In conclusion, our results suggest that the choice of haemodialysis membrane does not influence the outcome of the residual renal function. Renal function decreased significantly within 3 months on haemodialysis, independently of the type of dialyser membrane.

Acrylic Resins↗
PubMed1994

Involvement of angiotensin II and endothelin in matrix protein production and renal sclerosis.

PURPOSE: To review the evidence that links angiotensin II and endothelin as growth factors and as modifiers of extracellular matrix synthesis in renal cells, with particular reference to the effects of angiotensin converting enzyme (ACE) inhibition in models of renal injury. IN VITRO STUDIES: In cultured mesangial cells, both angiotensin II and endothelin promote contraction, proliferation/hypertrophy, signal transduction pathways, the activation of early growth genes, and the generation of inflammatory mediators, cytokines and growth factors. Both hormones have been shown to promote the synthesis of fibronectin and collagen in a dose-dependent manner. ACE inhibition attenuates the effect of endothelin-1, one of three isoforms of endothelin. ANIMAL STUDIES: In experimental models of renal injury, chiefly in those characterized by increased intraglomerular pressure, ACE inhibition has reduced proteinuria and glomerular and interstitial sclerosis. HUMAN STUDIES: ACE inhibition has been shown to have major beneficial effects in patients with diabetic nephropathy, even in those with normal blood pressure. CONCLUSIONS: Although the renal-protective effects of ACE inhibitors in experimental and human renal injury may reflect systemic and/or local hemodynamic effects of these drugs, their modulatory actions on extracellular matrix synthesis and proteinuria may contribute to the benefit of ACE-inhibitor therapy.

Angiotensin II↗
PubMed1993

[Calciphylaxis in chronic renal failure].

Three cases of calciphylaxis in patients with terminal renal insufficiency are discussed. The existence of metastatic calcifications, mainly vascular, in patients with chronic renal insufficiency is frequent. However calciphylaxis is a process which is rarely found in these patients. This entity is characterized by the obliteration of small vessels with ischemia and necrosis. The exceptionality of the disease, its difficult treatment and poor evolution make calciphylaxis a bad prognostic complication which should be considered in the differential diagnosis of cutaneous lesions in patients with chronic renal insufficiency.

Aged↗
PubMedDate not supplied

[Non-Hodgkin lymphoma, IgA nephropathy and renal cell carcinoma].

Glomerular diseases could complicate lymphoid malignancies. We identified a patient with non-Hodgkin's lymphoma showing elevated levels of serum IgA1 paraprotein, renal infiltration by B cells, IgA nephropathy and renal cell carcinoma. It seems that there is a possible pathogenic relationship between these entities.

Aged↗