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Rafael Santamaría

Publications and source records attributed to Rafael Santamaría.

5 recordsLinked to original sources
PubMed2005

Cytometric bead array (CBA) for the measurement of cytokines in urine and plasma of patients undergoing renal rejection.

Renal rejection is associated with an active immune response regulated by cytokines and in which immunocompetent cells are involved. Previous studies have measured high levels of cytokines in the urine and plasma in various renal dysfunction states. However, some methods used to measured cytokines hinder their use as a diagnostic tool in renal rejection. In this report, cytokine levels were determined in the plasma and urine of kidney transplant patients, with renal rejection and without it, using a cytometric bead array (CBA) technique. Concentrations of six human cytokines (IL-2, IL-4, IL-5, IL-10, TNF-alpha and INF-gamma) were established. Results show that patients who develop renal rejection presented high levels of IL-10 and IFN-gamma cytokines in plasma and urine compared to patients without renal rejection. The CBA technique displayed greater sensitivity in the determination of cytokines in urine than the conventional ELISA technique. Finally, when standard cytokines in plasma and in urine were compared, it was observed that, in plasma, levels of IL-4, IL-5, IL-10, TNF-alpha and IFN-gamma were detected, whereas in urine the levels detected were of IL-4, IL-5, IL-10 and IFN-gamma. These results indicate that the CBA assay is a sensitive method to measure cytokines in urine. In kidney transplant patients undergoing acute renal rejection, the presence of cytokines in urine reflects renal damage and could be a useful method in the diagnosis of renal rejection.

Adult↗
PubMed2005

Calcium-sensing receptor expression and parathyroid hormone secretion in hyperplastic parathyroid glands from humans.

In uremic patients, severe parathyroid hyperplasia is associated with reduced parathyroid calcium-sensing receptor (CaR) expression. Thus, in these patients, a high serum Ca concentration may be required to inhibit parathyroid hormone (PTH) secretion. This study compares the magnitude of reduction in CaR expression and the degree of the abnormality in Ca-regulated PTH release in vitro. A total of 50 glands from 23 hemodialysis patients with refractory hyperparathyroidism were studied. Tissue slices were incubated in vitro to evaluate (1) the PTH secretory output in a normal Ca concentration (1.25 mM) and (2) the PTH secretory response to high (1.5 mM) and low (0.6 mM) Ca concentration. Tissue aliquots were processed for determination of CaRmRNA expression. The results showed that, corrected for DNA, parathyroid tissue with lowest CaR expression secreted more PTH than that with relatively high CaR expression (146 +/- 23 versus 60 +/- 2 pg/microg DNA; P < 0.01). Furthermore, glands with low CaR expression demonstrated a blunted PTH secretory response to both the inhibitory effect of high Ca and the stimulatory effect of low Ca. The study also showed that the larger the gland, the lower the CaRmRNA expression. Thus, large parathyroid glands produce a large amount of PTH not only as a result of the increased gland size but also because the parathyroid tissue secretory output is increased. These abnormalities in PTH regulation are related to low CaR expression.

Female↗
PubMed2005

Necrotizing glomerulonephritis and pulmonary hemorrhage associated with carbimazole therapy.

Methimazole, carbimazole, and propylthiouracil (PTU) are the mainstays of antithyroid drug therapy. Adverse effects of these drugs have been documented in less than 15% of patients undergoing treatment for hyperthyroidism. Common problems include fever, skin rash, urticaria, arthralgias, and arthritis. Vasculitis associated with antineutrophil anticytoplasmic antibodies (ANCA) has been reported on several occasions following treatment with PTU. However, vasculitis rarely appears to be associated with carbimazole. We report the clinical history of a woman with a necrotizing glomerulonephritis and pulmonary hemorrhage associated with carbimazole therapy.

Antithyroid Agents↗
PubMed2005

Replicative senescence in patients with chronic kidney failure.

BACKGROUND: Chronic activation of immunocompetent cells may lead to stress-induced premature senescence (SIPS); these senescent cells are characterized by a decrease in telomere length. The present study evaluates SIPS in circulating immunocompetent cells from predialysis patients, patients on hemodialysis, and in renal transplant patients with normal renal function. METHODS: Determination of telomere length by flow-fluorescence in situ hybridization (FISH), expression of surface molecules, and evaluation of apoptosis was performed by flow cytometry. RESULTS: In uremic predialysis patients, we observed a subpopulation of lymphocytes with short telomeres. However, in this population of patients we did not observe SIPS mononuclear cells. In hemodialysis patients, we found a subpopulation of SIPS mononuclear cells that also showed phenotypic changes of proinflammatory activity. Finally, transplant patients with normal renal function also exhibited a subpopulation of SIPS lymphocytes, which can be attributed to chronic lymphocyte activation induced by the major histocompatibility complex. CONCLUSION: In chronic kidney disease patients, immunocompetent cells undergo SIPS, a process associated with chronic cell activation and induced by numerous stimuli including uremia, hemodialysis membranes, and bacterial products. Because SIPS immunocompetent cells are activated cells with proinflammatory features and live longer in peripheral blood, it is likely that SIPS cells contribute significantly to the chronic inflammatory state of patients with advanced renal failure.

Apoptosis↗