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Biomedical subjects

L Revert

Publications and source records attributed to L Revert.

At least 19 recordsLinked to original sources
PubMed1996

Linkage, clinical features, and prognosis of autosomal dominant polycystic kidney disease types 1 and 2.

Linkage analysis was performed on 49 Catalan families with autosomal dominant polycystic kidney disease obtained via the Nephrology Department and related nephrology centers. A total of 336 subjects, 267 at risk for the disease, were investigated using three microsatellites linked to polycystic kidney disease Type 1 (PKD1) and three microsatellites linked to PKD2. All of the subjects underwent physical and sonographic examination. The results demonstrate locus heterogeneity, with 0.85 as the maximum likelihood for the proportion of families linked to PKD1. All of the remaining families were found to be linked to PKD2. Analysis of clinical data in the PKD1 group (N = 146) versus the PKD2 group (N = 20) showed a milder form of the disease in the latter, with a later age at diagnosis (27.4 versus 41.4 yr, P = 0.0002), later age of onset of ESRD (53.4 versus 72.7 yr, P < 0.0001), later age of diagnosis of hypertension (34.8 versus 49.7 yr, P = 0.001) and lower prevalence of hypertension at younger ages. Sonographic findings did not differ significantly between both groups. Although anticipation was observed in both groups, it did not affect the majority of families. No signs of imprinting were found in this study, and the only gender effect was an earlier age of onset of ESRD in men than in women (49.5 versus 53.1 yr in PKD1, P < 0.01 and 70.57 versus 73.6 yr in PKD2, P = 0.1). Molecular analysis of autosomal-dominant polycystic kidney disease allows presymptomatic diagnosis in individuals younger than age 30, and helps in establishing prognosis.

Adult↗
PubMed1995

Effect of antihypertensive treatment on the increased beta 2-adrenoceptor density in patients with essential hypertension.

The effect of different antihypertensive drugs on the increased surface beta 2-adrenoceptor density in essential hypertension was evaluated to elucidate whether the possible effect of the treatment on these receptors was secondary to blood pressure decreases or a specific effect of the drugs. Thirty-nine untreated essential hypertensive patients and 28 normotensive control subjects were studied in basal conditions. Hypertensive patients were randomly assigned to three treatment groups: bisoprolol (10 mg/day, n = 15), enalapril (20 mg/day, n = 12), and verapamil SR (240 mg/day, n = 12), and were studied before and after 1 month of treatment. Plasma catecholamines were determined by a radioenzymatic assay. Surface beta 2-adrenoceptors were measured in intact lymphocytes by radioligand binding assay using the hydrophilic ligand [3H]-CGP12177. beta 2-adrenoceptor density was increased in hypertensive patients (P < .01). After treatment, mean blood pressure decreased similarly in the three groups, while plasma catecholamines showed no significant changes in any group. beta 2-adrenoceptor number decreased only in bisoprolol-treated patients (P < .05). Mean blood pressure decreases correlated with beta 2-adrenoceptor decrements only in bisoprolol-treated patients (r = 0.65, P < .05). beta 2-adrenoceptor density correlated with plasma epinephrine levels in the control group (r = -0.50, P < .01), but not in hypertensive patients before treatment. This correlation was also observed in hypertensive patients treated with bisoprolol (r = -0.52, P < .05), but not in those treated with verapamil or enalapril. Our results suggest that bisoprolol treatment reduces the increased surface beta 2-adrenoceptor density and restores its regulation by epinephrine in essential hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Uraemic medium causes endothelial cell dysfunction characterized by an alteration of the properties of its subendothelial matrix.

Uraemic patients suffer from haemorrhagic disorders and accelerated atherosclerosis. To evaluate the possible role of the vessel wall in these haemostatic alterations associated with uraemia, we investigated the effect of a uraemic milieu on human endothelial cell (EC) cultures and the reactivity of the extracellular matrices (ECM) generated by these cells towards platelets. EC cultures were exposed to a pool of sera (20% in the culture medium) obtained either from uraemic patients or from normal donors, and the following parameters were evaluated: (1) EC viability (trypan blue exclusion test); (2) von Willebrand factor (vWF) levels in supernatants and associated with ECM; (3) the reactivity of EC and EC-derived ECM towards platelets, measured 'ex vivo' under flow conditions (5 min, wall shear rate 800 s-1); and (4) ultrastructure of the ECM. The viability of EC cultured in the presence of uraemic sera was similar to controls. Platelet interaction with ECM generated by EC exposed to uraemic sera was significantly reduced (P < 0.05). This decrease was mainly related to a reduction in platelet adhesion (9.8 +/- 1.9% vs 16.7 +/- 1.8% in controls, P < 0.02). VWF levels in supernatants and associated with ECM were similar to controls. Ultrastructural analysis of the ECM generated by EC exposed to uraemic sera revealed a deficient matrix. An increased removal of EC was observed in experiments in which EC cultured in the presence of uraemic sera were perfused with citrated blood. These results indicate that a uraemic milieu induces quantitative and qualitative changes in the vascular subendothelium, characterized by a less intrincate network of fibrils, as well as a decreased attachment of EC and reduced thrombogenicity to the ECM. These changes may represent another mechanism which contributes to the haemostatic dysfunction observed in uraemic patients.

Blood Platelets↗
PubMed1995

Patients with multiple myeloma requiring long-term dialysis: presenting features, response to therapy, and outcome in a series of 20 cases.

From January 1982 to December 1993, 30 patients with multiple myeloma (MM) required haemodialysis (HD) at our institution. The subgroup of 20 patients who survived more than 2 months on HD is the subject of this study. Four patients were already on HD, due to previous nephropathy, when MM was diagnosed. 13 patients presented with acute renal failure and were on dialysis from the time of diagnosis. The remaining three cases developed renal failure later in the course of the disease. The objective response rate was 40% (8/20). Only two patients could discontinue HD (one had a late partial recovery and one received a kidney graft). Mean hospitalization per year was 19.3 d. The subgroup of patients who survived < 1 year spent a mean of 38.3 d in hospital. Whereas in the subgroup with a survival > 1 year mean hospitalization days was 9.6 (P < 0.001). The median survival was 20 months and six patients survived for > 3 years. In summary, patients with MM and severe renal failure who survive the first 2 months on dialysis have an objective response rate to chemotherapy of 40% and a median survival of almost 2 years, with 30% long-term survivors.

Acute Kidney Injury↗
PubMed1995

Increased plasma endothelin concentration in atherosclerotic renovascular hypertension.

The aim was to investigate circulating levels of immunoreactive endothelin (ir-ET) in atherosclerotic renovascular hypertension (RVH), and to assess the role of the kidneys in its overall plasma concentration. We studied 16 hypertensive patients with renal artery stenosis evidenced by angiography and admitted to hospital for the diagnostic evaluation of RVH by renal vein plasma renin activity (PRA) determinations. The right femoral vein was catheterized to simultaneously measure PRA and ir-ET in both renal veins and inferior vena cava below the origin of the renal veins. RVH was present in 9 patients as indicated by diagnostic PRA renal vein ratios and the remaining 7 patients were considered to have essential hypertension (EH). Patients with RVH showed a marked increase in systemic plasma ir-ET concentration (10.3 +/- 0.9 pg/ml). Despite a significant increase of PRA in the vein of the ischemic (IK) versus the contralateral (CK) kidney in patients with RVH, no significant differences in ir-ET concentration were observed between both kidneys. These results indicate that patients with RVH have increased circulating levels of ir-ET. However, the higher systemic plasma ir-ET do not arise from the renal circulation, since plasma ir-ET is significantly higher in systemic circulation than in renal veins.

Creatinine↗
PubMed1995

Reversible decrease of surface beta 2-adrenoceptor number and response in lymphocytes of patients with pheochromocytoma.

To study the effect of chronic exposure to elevated plasma catecholamines on surface beta 2-adrenoceptor density, we measured these receptors in the lymphocytes of 9 patients with pheochromocytoma as well as in 27 healthy control subjects. Binding experiments were performed on intact lymphocytes using the hydrophilic ligand [3H]-CGP12177. Lymphocyte beta 2-adrenergic response was also measured in three patients. beta 2-adrenoceptor density (p < 0.01), and isoproterenol-stimulated increase in cAMP were reduced in patients with pheochromocytoma. Both parameters normalized (p < 0.05) when patients were reevaluated 4 weeks after tumor removal, coinciding with normalization of plasma epinephrine (r = -0.95, p < 0.01) and to log of plasma norepinephrine (r = -0.58, p < 0.05) in patients. We conclude that chronic catecholamine excess induces a decrease of lymphocyte beta 2-adrenoceptor surface number and response that is reversible upon normalization of plasma catecholamine levels. This regulation is mainly dependent on plasma levels of the hormone epinephrine, but norepinephrine may also play a regulatory role at supraphysiological levels.

Adrenal Gland Neoplasms↗
PubMed1995

Long-term evolution of patients with isolated C3 mesangial glomerulonephritis.

Isolated mesangial C3 proliferative glomerulonephritis is a nephropathy poorly defined among glomerular diseases. Clinical picture is characterized by episodes of gross hematuria and/or persistent or recurrent microhematuria and/or proteinuria. Short-term prognosis (less than 3 years) is considered to be benign, although not much information is available in reference to long-term follow-up. We reviewed all renal biopsies performed in our center between 1978 and 1992 (n = 2,200) in order to study clinical course of these patients. Isolated mesangial C3 deposition was found in 11 cases (0.5%). Isolated proteinuria (> 0.5 g/d) was present in 3 patients and nephrotic syndrome in 2. Hematuria with proteinuria was detected in 5 patients. In one patient hematuria was the only clinical finding. Arterial hypertension was observed in 4 cases. At the time of renal biopsy, renal function was accurately normal in all but one patient. In our series, renal function showed no changes during the first 3 years, accordingly to data referred to in the literature. After 7 years of follow-up, however, renal function was declining in 4 of 5 patients who developed terminal renal failure up to requiring hemodialysis. Therefore, initial benign prognosis ascribed to this glomerulonephritis would not be confirmed in a long-term follow-up.

Adolescent↗
PubMed1995

Fibrillary glomerulonephritis and pulmonary hemorrhage in a patient with renal transplantation.

Fibrillary glomerulonephritis is an unusual kidney disease characterized by the deposition of immunoglobulins in a fibrillar pattern. Until recently it has been considered to involve the kidneys alone. We describe a patient who underwent renal transplantation and developed fibrillary glomerulonephritis with rapidly progressive renal failure and severe pulmonary hemorrhage two years and a half after transplantation. Nephropathy prior to transplantation was thought to be focal and segmental glomerulosclerosis. Diagnosis of fibrillary glomerulonephritis in renal allograft was confirmed by postmortem examination. 50% of the glomeruli with extracapillary crescents were observed on light microscopy. By immunofluorescence main deposition of IgA was detected in the glomerular capillar walls and the mesangium. Electron microscopy showed fibrillo-reticular deposits in the same place. Lung histology showed both old and recent areas of alveolar hemorrhage. Granular staining for IgA was observed in the alveolar walls by immunofluorescence. Ultrastructural analysis of the lung made evident fibrillo-reticulary deposits in the interstitium, similar than those observed in the glomeruli. The presence of these deposits in both renal and pulmonary tissues indicates the possibility of systemic involvement in fibrillary glomerulonephritis. In our case it could be related to the recurrence of this glomerulopathy in renal allograft.

Fatal Outcome↗
PubMed1995

Parathyroid hormone and platelet cytosolic calcium concentration in essential hypertension.

To investigate the possible relationships between blood pressure, parathyroid hormone (PTH) and platelet cytosolic Ca2+ concentration ([Ca2+]i) in patients with essential hypertension, we studied 17 patients with this disease aged 48 +/- 2 years and 17 normotensive controls aged 44 +/- 3 years. Platelet [Ca2+]i was measured by spectrofluorimetry using the dye Fura-2 acetoxymethylester. Patients with essential hypertension displayed lower levels of serum ionized Ca2+ (0.99 +/- 0.03 versus 1.1 +/- 0.01 mmol/l, P < 0.05) and higher serum intact PTH levels (37 +/- 3 versus 26 +/- pg/ml, (P < 0.01) than the normotensive controls. Although serum levels of intact PTH were significantly correlated with mean arterial pressure (MAP) in the combined group of subjects (r = 0.42, P < 0.05), there was no correlation when each group was considered separately. Resting platelet [Ca2+]i was also higher in patients than in controls (57 +/- 3 versus 48 +/- 2 nmol/l, P < 0.005). When platelets were stimulated in vitro with thrombin, the increment in [Ca2+]i was also greater in patients than in controls in the presence of extracellular Ca2+ (264 +/- 24 versus 194 +/- 19 nmol/l, P < 0.05) but not in its absence (123 +/- 12 versus 112 +/- 10 nmol/l). The thrombin-induced increment in [Ca2+]i was correlated with MAP in the hypertensive patients (r = 0.64, P < 0.01) and in the combined group of subjects (r = 0.42, P < 0.05). There was no relationship between resting or thrombin-induced [Ca2+]i and serum PTH in either group of patients or in the combined group of subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Neutrophil anticytoplasmic antibodies: their diagnostic utility in vasculitis and glomerulonephritis].

BACKGROUND: The prevalence and diagnostic usefulness of antineutrophil cytoplasmic antibodies (ANCA) were analyzed in a series of patients with different types of vasculitis, connective tissue diseases, nephropathies and lung diseases. METHODS: Six hundred seventy-six consecutive patients with systemic vasculitis, connective tissue diseases, nephropathies and different lung disturbances were included in the study. The ANCA were determined by indirect immunofluorescence (IIF) on neutrophils fixed in ethanol. For the detection of antimyeloperoxidase (MPO) antibodies (Ab) a new technique was developed consisting in the performance of IIF on neutrophils with a deficiency in MPO. The serologic samples were also analyzed by enzyme-linked immunosorbent assays with MPO and purified proteinase 3 (PR3). RESULTS: ANCA were demonstrated in 95 patients. A cytoplasmic pattern (c-ANCA) was detected in 25 cases (26%) and in 70 (74%) a perinuclear pattern (p-ANCA) was observed. Twenty-one of the 25 cases (84%) of c-ANCA corresponded to anti-PR3 Ab and 61 of the 70 (87%) of p-ANCA corresponded to anti-MPO Ab. The anti-PR3 Ab identified Wegener's granulomatosis, with a sensitivity and specificity for the generalized and clinically active forms being 65 and 88%, respectively. The anti-MPO Ab were principally detected in patients with rapidly progressive glomerulonephritis (RPGN) and hemorrhagic alveolar capillaritis. The sensitivity and specificity of the anti-MPO Ab for the RPGN and alveolar capillaritis were 75% and 98%. CONCLUSIONS: Two principal subtypes of ANCA may be detected, which also recognize two fundamental clinicopathologic entities. The high diagnostic sensitivity and specificity of these antibodies for each of the processes to which they are associated can justify the adoption of therapeutic measures in determined cases.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1994

Intracellular calcium concentration and activation of the Na+/H+ exchanger in essential hypertension.

To investigate the relationship between changes in intracellular calcium concentration ([Ca2+]i) and agonist-induced activation of the Na+/H+ exchanger in essential hypertension (EH), platelet [Ca2+]i and pHi were measured in 24 patients with EH (14 males) aged 48 +/- 2 years and 23 matched normotensive controls (NT) (12 males) aged 45 +/- 3 years. Measurements were done with spectrofluorimetry using the dyes Fura-2 for [Ca2+]i and BCECF for pHi. [Ca2+]i and pHi were measured in the resting condition and after stimulation in vitro with 0.1 U/ml human thrombin. The thrombin-induced rise in pHi was Na+ dependent and amiloride sensitive, indicating that it was mediated by the Na+/H+ exchanger. Unstimulated [Ca2+]i was higher in patients with EH than in NT (60 +/- 3 vs. 48 +/- 1 nmol/liter, P < 0.005), but there were no differences in resting pHi between both groups (7.16 +/- 0.01 vs. 7.16 +/- 0.008). In the presence of 1 mmol/liter external calcium (Ca2+o), thrombin-induced increment in [Ca2+]i was significantly greater in patients with EH than in NT (281 +/- 21 vs. 206 +/- 19; P < 0.05) as was the pHi increment (EH: 0.137 +/- 0.01; NT: 0.095 +/- 0.01; P < 0.05). Both agonist-induced increments in [Ca2+]i and in pHi were correlated with mean arterial pressure (MAP) only in the EH group (r = 0.58, P < 0.005 and r = 0.59, P < 0.005, respectively). The agonist-induced rise in pHi was positively correlated with the rise in [Ca2+]i both in the EH group (r = 0.65, P < 0.001) and in the NT (r = 0.55, P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Platelets↗
PubMed1994

Effect of antihypertensive treatment on intracellular calcium concentration and intracellular pH in essential hypertension.

The platelet intracellular calcium concentration ([Ca2+]i) and intracellular pH (pHi) were measured by spectrofluorimetry with the dyes Fura-2 and BCECF, respectively, in 19 patients with essential hypertension (10 males), aged 48 +/- 2 years, before and after 12 weeks of antihypertensive treatment and in 19 normotensive controls (11 males), aged 46 +/- 3 years. [Ca2+]i and pHi were measured in the resting state and after stimulation in vitro with 0.1 U/ml human thrombin. In patients with essential hypertension, both resting [Ca2+]i (61 +/- 4 nmol/l) and thrombin-induced maximal increase in [Ca2]i (291 +/- 26 nmol/l) were significantly (P < 0.01) greater than in the normotensive controls (resting 49 +/- 2 nmol/l and thrombin-induced 199 +/- 21 nmol/l). With respect to pHi, no difference in resting pHi between both groups was found (7.16 +/- 0.01 vs. 7.16 +/- 0.01). However, pHi increment at 300 seconds in response to thrombin was higher in the patients with essential hypertension than in the controls (0.131 +/- 0.02 vs. 0.083 +/- 0.01 pH units, P < 0.05). The increment in pHi was blunted by the amiloride derivative EIPA, indicating that it was mediated by the Na+/H+ exchanger. After antihypertensive therapy in the essential hypertensive patients, basal [Ca2+]i was significantly reduced (52 +/- 2 nmol/l, P < 0.01) and was not statistically different to the value found in the normotensive controls. Resting pHi suffered no significant modification after treatment (7.17 +/- 0.01, P = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗