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Biomedical subjects

A Oliet

Publications and source records attributed to A Oliet.

35 records · Page 2Linked to original sources

Effects of angiotensin converting enzyme inhibitors on the progression of renal failure and proteinuria in humans.

We studied the long-term effect of an angiotensin converting enzyme (ACE) inhibitor, captopril, on the progression of chronic renal failure and on the rate of urinary protein excretion. When compared with standard triple therapy, captopril slowed the progression of renal failure. Captopril was also able to reduce the proteinuria of non-diabetic glomerular origin. This reduction was not dependent on the presence or absence of arterial hypertension but was limited by the presence of low serum albumin levels, and only occurred in patients with proteinuria in excess of 3 g/24 h.

Adult↗

Effects of nisoldipine on renal function in normal volunteers and essential hypertensive patients.

To evaluate the renal effects of nisoldipine (N), a dihydropyridine derivative, we have evaluated the variations of blood pressure (BP), heart rate, glomerular filtration rate (GFR), renal plasma flow (RPF), 24-h natriuresis, and renal capacity to excrete an i.v. sodium load (2,000 ml isotonic saline in 4-h) in response to a 4-day course of therapy with placebo (P) and N in six normotensive volunteers and six mild-to-moderate essential hypertensive patients. Both volunteers and patients were studied on two constant diets (20 and 150 mEq of sodium daily). No parameters changed after P. On the contrary, N induced a significant fall of BP (p less than 0.01) in the group of patients but not in volunteers. In both groups RPF and GFR increased significantly (p less than 0.05-0.01) while on a low sodium intake but remained constant when sodium intake was high. In the two groups studied, nisoldipine exhibited natriuretic properties manifested by an increase in the 24-h output of sodium as well as by an increased renal capacity to excrete the i.v. sodium load. These natriuretic properties were present in both situations of sodium load and could be facilitated by the change in renal hemodynamics observed when the intake of sodium was low.

Adult↗

[Clinical characteristics of arterial hypertension in the elderly].

The clinical characteristics of systolic and diastolic hypertension in 75 and of systolic hypertension in 50 elderly patients have been studied and the results have been compared to those obtained in 23 normotense elderly controls and 500 young patients with essential hypertension. A greater incidence in cardiovascular and neurologic morbility was observed in the hypertense elderly, existing also a greater incidence of electrocardiographic abnormalities and impairment in renal function. The changes in blood pressure with postural changes and isometric and physical exercise were evaluated in a subgroup of these patients, finding that the elderly with hypertension, specially those with systolic hypertension, showed orthostatic hypotension, and an increase in blood pressure with exercise, reaching levels that could potentially cause the clinical complications.

Aged↗

Periglomerular granulomatosis. A limited form of Wegener's granulomatosis with exclusive renal involvement?

Three episodes of acute renal failure, all of them requiring hemodialysis, were observed in two patients. The renal biopsy specimens showed a massive periglomerular granulomatosis with crescentic glomerulonephritis. With cyclophosphamide therapy, a dramatic improvement in renal function was observed in both patients. Although the histologic findings and the response to cyclophosphamide therapy were characteristic of Wegener's granulomatosis, there was no evidence of respiratory involvement or extrarenal manifestations throughout the patients' clinical course. We think that these cases could represent limited forms of Wegener's granulomatosis with exclusive renal involvement.

Acute Kidney Injury↗

Control of hypertension with the angiotensin converting enzyme inhibitor captopril reduces glomerular proteinuria.

Recent experimental and clinical data have suggested that angiotension converting enzyme (ACE) inhibitors may decrease glomerular proteinuria by specific effects on the glomerulus. We studied a group of 15 adult patients with chronic renal failure and proteinuria due to various glomerulopathies. These patients had mild to moderate hypertension which was effectively controlled with conventional antihypertensive therapy. We then treated the patients with captopril, maintaining a similar dietary protein and salt intake. After 6 months of study, proteinuria was reduced significantly without reduction in inulin or para-aminohippurate clearance. This supports the concept that captopril may have salutary effects on the glomerulus, independently of its effect on systemic blood pressure.

Blood Pressure↗

Persistence of the natriuretic effect of calcium entry blockers.

In order to elucidate whether or not the natriuretic properties of calcium entry blockers persist during the long-term administration of the drug, we have investigated the renal capacity to excrete an intravenous sodium load (2,000 ml of isotonic saline in 4 h) in a group of eight mild to moderate essential hypertensive patients, before and after 1, 8, and 24 weeks of treatment with nitrendipine. The following parameters were measured before and hourly during saline infusion: blood pressure, and plasma and urine sodium and potassium. For 5 days prior to the performance of the test, the patients received a diet containing 120 mEq of sodium daily. Nitrendipine induced a significant fall of both systolic and diastolic blood pressure (p less than 0.05-0.01) that was maintained throughout the study. A significant increase of the cumulative renal sodium output (microEq/min/h) was observed after 1, 8, and 24 weeks (p less than 0.05-0.001) of therapy with the calcium entry blocker. Meanwhile, plasma sodium and potassium and the kaliuresis did not change significantly. These results indicate that the natriuretic effect of calcium entry blockers is still present after long-term treatment.

Adult↗

Fractional excretion of sodium represents an index of cyclosporine nephrotoxicity in the early post-transplant period.

We reviewed the evolution of FENa in the EPP (first 4 weeks) in a group of CyA-treated patients as well as Aza-treated patients who did not present with acute rejection during this period of time. The CyA-treated patients showed lower values of FENa than did Aza-treated patients. Values of FENa below 1% were found in 51% of CyA- and 0% Aza-treated patients (P less than .01) before RFR. The finding of low FENa values was accompanied by more prolonged oliguric and RFR phases. Furthermore, the lower the level of FENa, the higher the prolongation of renal failure. We concluded that FENa values could probably be an index of CyA nephrotoxicity in the EPP.

Azathioprine↗

Peritoneal sodium mass removal in continuous ambulatory peritoneal dialysis and automated peritoneal dialysis: influence on blood pressure control.

BACKGROUND/AIM: Sodium and water retention is common in peritoneal dialysis patients and contributes to cardiovascular disease. As peritoneal sodium removal depends partly on dwell time, and automated peritoneal dialysis (APD) often uses short dwell time exchanges, the aim of this study was to compare the 24-hour peritoneal sodium removal in APD and standard continuous ambulatory peritoneal dialysis (CAPD) patients and to analyze its possible influence on blood pressure control. METHODS: A total of 53 sodium balance studies (30 in APD and 23 in CAPD) were performed in 36 stable peritoneal dialysis patients. The 24-hour net removal of sodium was calculated as follows: M = ViCi - VdCd, where Vd is the 24-hour drained volume, Cd is the solute sodium concentration in Vd, Vi is the amount of solution used during a 24-hour period, and Ci is the sodium concentration in Vi. Peritoneal sodium removal was compared between APD and CAPD patients. Residual renal function, serum sodium concentration, daily urinary sodium losses, weekly peritoneal Kt/V and creatinine clearance, 4-hour dialysate/plasma creatinine ratio, proportion of hypertonic solutions, net ultrafiltration, systolic and diastolic blood pressures, and need for antihypertensive therapy were also compared between the groups. RESULTS: Peritoneal sodium removal was higher (p < 0.001) in CAPD than in APD patients. There were no significant differences in residual renal function, serum sodium concentration, urinary sodium losses, peritoneal urea or creatinine clearances, 4-hour dialysate/plasma creatinine ratio, or proportion of hypertonic solutions between groups. The net ultrafiltration was higher in CAPD patients and correlated strongly (r = 0.82; p < 0.001) with peritoneal sodium removal. In APD patients, peritoneal sodium removal increased significantly only in those patients with a second daytime exchange. The systolic blood pressure was higher (p < 0.05) in APD patients, and the proportion of patients with antihypertensive therapy was also higher in APD patients, although no significant relationship between blood pressure values and amount of peritoneal sodium removal was found. CONCLUSIONS: The 24-hour sodium removal is higher in CAPD than in APD patients, and there is a trend towards better hypertension control in CAPD patients. As hypertension control and volume status are important indices of peritoneal dialysis adequacy, our results have to be considered in the choice of the peritoneal dialysis modality.

Adult↗

[Influencing factors in the control of phosphorus in peritoneal dialysis. Therapeutic options].

UNLABELLED: Impaired phosphate excretion resulting in hyperphosphatemia is one of the earliest consequences of chronic renal failure. To control serum phosphate levels, we can use the following therapies: 1) Restriction of dietary phosphate (but on CAPD, obligatory protein losses via peritoneal fluid makes impractical any reduction of phosphate diet. 2) Reduction of phosphate absorption, using phosphate binders. 3) Peritoneal phosphate removal. OBJECTIVE: 1) To evaluate the factors affecting peritoneal phosphate removal such as plasma phosphate, peritoneal membrane transport type, peritoneal dialysis modality prescription (CAPD or APD) and daily dialysate volume. 2) To test the best calcium concentration in the peritoneal dialysis fluid (5, 6 or 7 mg/dl) in order to permit the use of calcium carbonate or acetate without the risk of hypercalcemia or hyperparathyroidism. METHOD: Phosphate was measured in seventy 24-hour dialysate collections, 33 from patients on CAPD and 37 from patients on APD. 24-hour peritoneal phosphate removal (mg/24 hours) and weekly peritoneal phosphate clearance was calculated (L/week). The peritoneal membrane was studied by the peritoneal equilibrium test (PET), using a 2.27% glucose. We calculated also the peritoneal calcium balance in 25 daily peritoneal fluid collections from patients using a calcium dialysate concentration of 5, 6 or 7 mg/dl each one. IPTH levels and doses of vitamin D were compared at 6 months in patients using a calcium concentration of 5, 6 or 7 mg/dl from the beginning of peritoneal dialysis (5 patients of each calcium dialysate concentration). RESULTS: Weekly peritoneal phosphate clearance (WPC) were higher or APD than on CAPD (51 +/- 21 vs 41 +/- 14, p < 0.005). Daily dialysate volume was also higher on APD (14 +/- 4 vs 7.8 +/- 1.8 L/day, p < 0.001). WPC was higher on APD when a mild-day exchange was done (61 +/- 23 vs 45 +/- 15, p < 0.005), instead an equal total daily volume of the dialysate. Peritoneal calcium balance was significantly more negative in patients using a calcium in the dialysis fluid of 5 than 6 or 7 mg/dl (-125 +/- 7 vs -18 +/- 41 vs -11 +/- 49, p < 0.001). At 6 months, patients using a calcium fluid concentration of 5 mg/dl increased iPTH levels (from 160 +/- 101 to 332 +/- 153, p < 0.001) and vitamin D needs (from 0 to 1.87 +/- 0.37 mcg/week, p < 0.001). In summary, peritoneal phosphate clearance depends on plasma phosphate levels, daily volume of dialysate prescribed and peritoneal membrane transport characteristics. It can be improved by increasing the total peritoneal fluid. On APD, a mild-day exchange may improve phosphate clearance, without total volume increase. The risk of secondary hyperparathyroidism can be decreased with a calcium fluid concentration of 6 mg/dl, which was shown to be better than 5 mg/dl when calcium phosphate binders are not correctly taken.

Calcium↗