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Biomedical subjects

G Maschio

Publications and source records attributed to G Maschio.

At least 73 records · Page 4Linked to original sources
PubMed1990

Renal functional reserve in patients with essential hypertension: effect of inhibition of the renin--angiotensin system.

1. Urinary albumin excretion and the effect of an acute oral protein load (a meat meal) on glomerular filtration rate ('renal functional reserve') were evaluated in 15 essential hypertensive patients with preserved renal function and compared with 12 normal subjects. 2. Seven patients had microalbuminuria (greater than 30 mg/day) that was not correlated with blood pressure values. 3. After an oral protein load, an average increase of 20% in glomerular filtration rate (from 91 +/- 19 to 110 +/- 27 ml min-1 1.73 m-2 was found in the hypertensive patients. This change was not statistically different from that observed in normal controls (from 102 +/- 7 to 124 +/- 9 ml min-1 1.73 m-2). The glomerular response in hypertensive patients was independent of age, duration of hypertension, blood pressure, plasma renin activity, urinary albumin excretion and retinal vascular alterations. 4. All patients were re-evaluated after 6 weeks treatment with a new orally active angiotensin-converting enzyme inhibitor, benazepril. Systolic, diastolic and mean blood pressures were lowered in all the patients, but the drug did not affect the glomerular response to acute protein ingestion or the magnitude of urinary albumin excretion. 5. The findings of a normal 'renal functional reserve' and a lack of change in both urinary albumin excretion and the glomerular response after angiotensin-converting enzyme inhibition cast doubt on the existence of increased intraglomerular pressure in hypertensive patients.

Adult↗
PubMed1990

The protein catabolic rate as a measure of protein intake in dialysis patients: usefulness and limits.

To test the validity of the determination of protein catabolic rate (PCR) as a measure of protein intake in dialysis patients, we studied a selected population of 27 well-dialysed patients, free of catabolic illnesses, and in apparent clinical stability. Daily protein intake, obtained by controlled dietary records, and protein catabolic rate, measured by urea kinetic modeling, were 1.02 +/- 0.26 and 0.99 +/- 0.16 g/kg respectively. Although there was a good correspondence between protein intake and protein catabolic rate in many of our patients, in the six cases with dietary protein content less than 0.8 g/kg, protein catabolic rate was regularly greater than 0.8 g/kg; on the contrary, in four patients ingesting more than 1.2 g/kg of protein, protein catabolic rate values were significantly less than protein intake. Our results demonstrate that some degree of nitrogen imbalance may be present in about 25% of clinically stable dialysis patients, and suggest that current concepts of clinical stability do not imply a stable metabolic state in a substantial portion of dialysis patients. Therefore, protein catabolic rate determination does not provide a reliable index of protein intake in many dialysis patients.

Adult↗
PubMed1990

Systemic and renal effects of a new angiotensin converting enzyme inhibitor, benazepril, in essential hypertension.

Seventeen essential hypertensive patients with normal renal function were treated with a new non-sulphydryl orally active angiotensin converting enzyme (ACE) inhibitor, benazepril, 10 mg given once or twice daily, according to diastolic blood pressure levels, for 6 weeks. In all patients, changes in blood pressure, systemic and renal hemodynamics, plasma renin activity and urinary aldosterone and albumin excretions were assessed at the end of a 2-week placebo run-in period and at the end of the study. Benazepril monotherapy controlled blood pressure well. No changes in cardiac output, heart rate or stroke volume were observed, while peripheral vascular resistance was significantly decreased (-11%, P less than 0.05). Plasma volume was unaltered. The glomerular filtration rate was stable, but effective renal plasma flow was increased because of the marked reduction in renal vascular resistance (-35%) and, therefore, the filtration fraction was decreased. Urinary albumin excretion remained unchanged. A significant increase in plasma renin activity (P less than 0.001) and a decrease in urinary aldosterone excretion were seen. No side effects were observed during the treatment period. In conclusion, our results suggest that benazepril alone is an effective antihypertensive agent in patients with essential hypertension. The blood pressure lowering effect is due mainly to systemic vasodilation and is observed up to 24 h after administration of the drug. The vasodilation appears to be more consistent in the renal than in the systemic circulation.

Adult↗
PubMed1990

Cell membrane lipid composition in CAPD patients.

We analyzed the erythrocyte membrane lipid composition in 11 non-diabetic CAPD patients on treatment for 3-78 months and in a control group of 12 subjects. The mean total values of both saturated fatty acids and unsaturated fatty acids were not statistically different in CAPD patients and in controls but the composition of fatty acids of in cell membranes was altered. In fact, CAPD patients had a higher percentage of monounsaturated fatty acids and a lower percentage of polyunsaturated fatty acids than controls. This increase MUFA/PUFA ratio might reflect either a preferential cell membrane uptake of MUFA or a relative PUFA deficiency due to an increased lipid peroxidation.

Aged↗
PubMed1990

Modification of serum and membrane lipid composition induced by diet in patients with chronic renal failure.

Disorders of lipid metabolism during chronic renal failure (CRF) play a crucial role in the pathogenesis of early cardiovascular complication of this syndrome. In addition, some experimental evidence suggests that hyperlipidemia may accelerate progression of renal disease. We have studied 65 patients with CRF (S-creatinine 1.5-9.0 mg/dl), 52.3% of whom were hypertensive. Patients were divided in 2 groups matched for age, sex and degree of renal failure: group 1 was kept for 36 +/- 8 months on a free diet; group 2 was kept for 39 +/- 6 months on a low-protein diet with an elevated polyunsaturated/saturated fatty acid (PUFA/SFA) ratio. We found significantly higher levels of triglycerides (TG) and lower levels of esterified cholesterol in high density lipoprotein (HDL-C) in group 1 than in group 2. Patients on the diet had a lower percentage of membrane SFA and a higher percentage of PUFA than patients on free diet. Only in group 1 a direct correlation between cholesterol/phospholipid (Chol/P) ratio and age was observed; in group 2, a negative correlation between levels of PUFA and TG and between linoleic/oleic (Lin/Ol) ratio and serum Chol was shown. S-creatinine levels were directly correlated with Chol/P ratio in group 1 and indirectly with Lin/Ol ratio and PUFA in group 2. These data show that a low-protein diet, containing an elevated PUFA/SFA ratio, is able to counteract lipid abnormalities in patients with CRF and the normalization of this pattern is associated with significant improvement of membrane lipid composition and, presumably, of "functional" activity of cell membranes with a better control of supposed "renal lipoprotein toxicity".

Adult↗
PubMed1990

Effects of ketanserin administration on lipid metabolism and platelet aggregation in hypertensive patients.

Lowering blood pressure is not totally effective in preventing the atherosclerotic complications of systemic hypertension. In hypertensive patients both platelet hyperaggregation and dyslipidemia have been suggested as important risk factors. The effect of 8 weeks' treatment with ketanserin on blood pressure, serum lipid parameters (cholesterol, triglycerides, LDL, HDL-C, apolipoprotein A1 and B) and platelet aggregation, induced by collagen, ADP, arachidonic acid, was evaluated in 10 patients with essential hypertension. Ketanserin was effective in lowering blood pressure in all patients, 6 of whom became normotensive. Both CHOL and TG levels and APO B were significantly reduced, whereas HDL-C and APO A1 were significantly increased after treatment. These results might be attributed to the antagonistic activity of ketanserin on alpha-1 adrenoceptors with a consequent inhibition of phosphodiesterase. Platelet aggregation, after stimulation with collagen and arachidonic acid, was significantly reduced secondary to the inhibition of intraplatelet serotonin synthesis and release. These results suggest that keranserin is effective in reducing blood pressure and in achieving normal serum lipid pattern and platelet aggregation. Therefore, this drug might be helpful in controlling the main risk factors for cardiovascular damage.

Adult↗
PubMed1990

Antihypertensive therapy with ketanserin: effects on central and renal hemodynamics, and microalbuminuria.

Ten patients with essential hypertension and normal renal function were treated with ketanserin (20-40 mg twice a day), administered for 8 weeks. In all patients, the changes in systemic and renal hemodynamics, and in urine albumin excretion, were assessed. Ketanserin monotherapy effectively lowered blood pressure in all patients. No change in cardiac output, pulse rate and stroke volume was observed; peripheral vascular resistance was significantly decreased. Plasma volume was unaltered. Renal plasma flow, glomerular filtration rate and filtration fraction were stable, with a slight but not significant reduction in renal vascular resistance. Urine albumin excretion remained unchanged. No relevant side effects were observed during the treatment period. In conclusion, our results confirm that ketanserin alone is an effective antihypertensive agent in patients with uncomplicated essential hypertension. The blood pressure lowering effect is mainly due to the systemic vasodilatation; renal hemodynamics and function are well preserved.

Adult↗
PubMed1989

Different protein diets in renal failure: a self-controlled study.

The progression of renal failure on 2 different protein and phosphate diets was evaluated in 7 patients with chronic renal failure. We decided on three study periods for each patient: period A (low-protein diet: 0.6 g/kg of protein, 600 mg of phosphate) averaged 12 months; period B (normal protein diet: 0.9 g/kg of protein, 800 mg of phosphate) lasted 9 months; period C (low-protein diet as for period A) averaged 9 months. The slopes of 1/Scr were 0.003 (period A), -0.016 (period B) and 0.009 dl/mg/month (period C). The GFR (125I-iothalamate clearance) changed from 42.6 to 45.6 ml/min/1.73 m2 in period A, from 51.9 to 40.7 in period B and from 40.5 to 44.6 in period C. The results show changes in renal function when dietary protein and phosphate intakes exceeding 0.6 g/kg and 600 mg/day, respectively, are administered to patients with GFRs ranging from 24 to 66 ml/min.

Adult↗
PubMed1989

Effects of a protein load in patients with early chronic renal failure before and after angiotensin II blockade.

We studied the effects of mid-term enalapril administration on protein-load-induced renal responses in 10 patients with early chronic renal failure (serum creatinine 2.70 +/- 1.0 mg/dl). The oral protein load was performed twice, before and after a 10-day therapy with enalapril. Glomerular filtration rate (125I-iothalamate clearance) rose from 22.5 +/- 10.6 to 60.1 +/- 32.8 ml/min after the protein load before enalapril; it did not change after the protein load during enalapril therapy. Percent fractional excretion of sodium, urinary osmolality and free water clearance were significantly affected only by the protein load before enalapril. Enalapril blunts the protein-load-induced changes in glomerular filtration rate and in tubular function; these effects might be mediated by angiotensin II blockade.

Adult↗
PubMed1989

Serum lipids in patients with chronic renal failure on long-term, protein-restricted diets.

Disordered lipid metabolism is believed to play an important role in accelerating the progression of chronic renal disease toward uremia. We examine this hypothetic role of lipids in a large population of patients on long-term dietary protein restriction. In our experience, there is no conclusive evidence that lipids may accelerate the progression of functional deterioration in patients with reduced renal function. Hyperlipidemia seems to be only one among the many factors affecting the prognosis of primary renal disease. Dietary protein restriction is effective in maintaining normal or only slightly elevated serum lipid levels in patients with early renal failure. Moreover, patients with renal failure maintained on this diet, which provides an elevated ratio of polyunsaturated to saturated fatty acids, have a more favorable lipid composition of erythrocyte membrane (low percentage of saturated fatty acids and high percentage of polyunsaturated fatty acids) when compared with patients on an unrestricted diet.

Dietary Fats, Unsaturated↗