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Biomedical subjects

G Maschio

Publications and source records attributed to G Maschio.

At least 55 records · Page 3Linked to original sources

Nutrition and the kidney: how to manage patients with renal failure.

Nutrition is believed to play a key role in the management of chronic and acute renal failure. Considerable evidence suggests that unrestricted protein diets accelerate the progression of chronic renal failure. As a result, recommendations have evolved limiting the quantity and quality of nitrogen intake with the goal of slowing the progression to dialysis dependency. Acute renal failure offers different challenges in view of its common association with hypermetabolic states. With respect to nitrogen substrate administration, the use of mixed formulations of essential plus nonessential amino acids seems to be as effective as essential amino acids alone.

Dietary Proteins↗

ACE inhibition reduces proteinuria in normotensive patients with IgA nephropathy: a multicentre, randomized, placebo-controlled study.

A multicentre, randomized, placebo-controlled study was performed in 39 adult patients with biopsy-proven IgA nephropathy with the aim of comparing the effects of the ACE inhibitor fosinopril and placebo on proteinuria. All patients had normal blood pressure and normal renal function. Proteinuria ranged from 1.0 to 2.5 g/24 h. After a 3-month run-in period, fosinopril and placebo were randomly administered in two 4-month sequences separated from cross-over treatment by a 1-month interval. The mean values of creatinine clearance did not change during either the placebo or the treatment sequences. The mean values of mean arterial pressure (MAP) were significantly lower during the fosinopril sequence (90.4 +/- 9.0 mmHg) than in basal conditions (92.8 +/- 9.1 mmHg) (P = 0.034). The mean basal values of proteinuria were 1.74 +/- 0.84 g/24 h. They were unchanged during the placebo sequence (1.79 +/- 1.20) and fell to 1.37 +/- 0.98 g/24 h after 4 months of fosinopril treatment. Using a multivariate statistical analysis, the treatment effect by time on proteinuria was significantly evident only in the fosinopril sequence (Wilks test, P = 0.033). Changes in protein excretion were not correlated with changes in MAP, baseline plasma renin activity, and urinary sodium excretion. This controlled study shows that fosinopril can significantly reduce proteinuria even in normotensive patients with IgA nephropathy. Obviously, the results of treatment with ACE inhibitors on long-term renal prognosis remain to be elucidated.

Adolescent↗

Molecular genetic diagnosis of autosomal dominant polycystic kidney disease in a newborn with bilateral cystic kidneys detected prenatally and multiple skeletal malformations.

We report a case of an unusual prenatal presentation of polycystic kidneys associated with multiple skeletal limb defects, including polydactyly, syndactyly, bilateral agenesis of the tibia, and club foot. The ultrasonographic picture was consistent with a diagnosis of polycystic kidney disease, either the adult onset autosomal dominant type (ADPKD) or the early onset autosomal recessive form (ARPKD). However, there was a positive family history for ADPKD. Linkage analysis was performed in 10 family members, of whom four were affected, using six flanking DNA markers tightly linked to the PKD1 locus on chromosome 16p, and one marker linked to the putative PKD2 locus on chromosome 2p. Lod score determinations indicated that the affected gene in the family is most likely PKD1. The patient inherited the disease linked haplotype from his affected mother.

Adult↗

Hyperparathyroidism: cause or consequence of recurrent calcium nephrolithiasis?

Primary hyperparathyroidism (PHP) might be characterized by either prevailing bone or renal stone patterns with different metabolic features. To explore the possibility of different hormonal patterns we studied 129 patients with PHP: 95 stone formers (SF) and 34 nonstone formers (NSF). Females prevailed over males in both groups. Severe and specific bone lesions were more evident in NSF than SF. Parathyroid gland histology displayed a prevalence of adenoma in NSF, whereas isolated hyperplasia prevailed in SF. SF had lower levels of serum Ca, urinary Ca, ALP and serum PTH than NSF. As expected serum 1,25-dihydroxyvitamin D [1,25(OH)2 D] levels were greater in both groups of patients than in controls but we found no difference between the two groups. 25-Hydroxyvitamin D was neither increased with respect to controls nor different between groups. We conclude that patients with PHP may represent well separated metabolic and clinical entities, but we cannot confirm that serum 1,25(OH)2D levels play a key role in discriminating the different clinical features. In addition, the findings of predominant parathyroid hyperplasia in SF and the clinical evidence of recurrent hyperparathyroidism only in these patients suggest the possibility that the endocrine disorder might be the consequence over time rather than the cause of nephrolithiasis.

Adult↗

Linkage analysis for the diagnosis of autosomal dominant polycystic kidney disease, and for the determination of genetic heterogeneity in Italian families.

Sixty-eight individuals from six Italian families in which autosomal dominant polycystic kidney disease (ADPKD) is segregating, were typed in DNA polymorphisms linked to the PKD1 locus on chromosome 16. A total of ten probes were used: 3' HVR, HMJ1, EKMDA, GGG1, 26-6, VK5B, 218EP6, 24.1, CRI090, and 41.1. Zmax was 4.502 at theta = 0.082 between ADPKD and 3'HVR, and 4.382, 1.947, and 1.576 between ADPKD and GGG1, 26.6, and 218EP6, respectively, at theta = 0.0. No clear evidence of genetic heterogeneity was found. Multipoint analyses were consistent with linkage to PKD1. Twenty-nine diagnoses and 16 exclusions made by ultrasonography were confirmed by genotype determinations; in two clinically uncertain cases, DNA analysis predicted one individual as being affected and the other unaffected.

Adult↗

Is there a "point of no return" in progressive renal disease?

The pathogenesis of progressive renal damage is most probably multifactorial. Whatever the mechanisms involved in renal disease progression, the existence of a "point of no return" has been hypothesized, that is, a stage of structural and functional damage beyond which progression of renal disease occurs independently of dietary measures and/or pharmacological treatment. In experimental animals, dietary protein and phosphate restriction is not fully successful in ameliorating the progression of functional deterioration if administered when renal injury is severe and long standing. Similarly, late treatment with various pharmacological agents (mainly antihypertensive drugs) is less effective than early administration of the same substances. A serum creatinine of 176 mumol/L seems a critical point discriminating the results of either dietary protein and phosphate restriction or antihypertensive treatment in patients with chronic renal disease. The protective effects of both dietary and nondietary intervention seem to be most effective when at least 50% of the residual renal mass is still functioning. The extent to which glomerular sclerosis, vascular hyalinosis, and interstitial fibrosis have already developed can probably blunt or avert the expected results of treatment. Some clinical tests may identify those patients who would benefit from measures such as the reduction in glomerular hemodynamic stress, the long-term inhibition of the renin-angiotensin system, and the aggressive treatment of systemic hypertension. The continuous search for a rational preventive treatment before the disease process has reached the "point of no return" will undoubtedly constitute a formidable task for the modern nephrologist.

Animals↗

Systemic hemodynamic pattern in primary hyperparathyroidism and its changes after parathyroidectomy.

Twelve patients (7 men and 5 women) with an average age of 53 years (range 37-69) were hospitalized for renal stones and found to have primary hyperparathyroidism. Five were hypertensive and 7 normotensive. The systemic hemodynamics, plasma renin activity and glomerular filtration rate were evaluated before and at least 6 months after removal of a parathyroid adenoma. After surgery the mean intra-arterial blood pressure fell in almost all patients, due to some reduction in the peripheral vascular resistance index with no change in the cardiac index. However, the hemodynamic variations were not uniform in all patients. No change was seen in plasma renin activity and glomerular filtration rate. A positive correlation between the percent change in mean arterial pressure and percent decrease in total serum calcium was found. The results obtained indicate that it is likely that hypercalcemia plays some role both in patients with high and those with normal blood pressure. The systemic hemodynamic changes after parathyroidectomy indicate that the fall in peripheral vascular resistance could have a certain influence.

Adult↗

Effect of dietary proteins and lipids in patients with membranous nephropathy and nephrotic syndrome.

Twenty-four patients with idiopathic membranous nephropathy, long-lasting nephrotic syndrome and serum creatinine less than 2 mg/dl ate sequentially, in a randomized cross-over design, a normal protein diet containing 1.1 +/- 0.3 g/kg/day of proteins and a low protein diet containing 0.7 +/- 0.1 g/kg/day of protein, each diet for a period of 3 months. Both diets were low in fat (less than 30% of total calories) and cholesterol (less than 200 mg/day) content and rich in polyunsaturated fatty acids and in linoleic acid (10% of energy). Random assignment to one of the two 3 month diet periods was done after a RUN-IN period of at least one month on the hypolipidic normal protein diet. Glomerular filtration rate (inulin clearance), 24 hour urinary protein loss and serum albumin concentration did not significantly differ at the end of the two diet periods, indicating that long-term restriction of protein intake does not modify GFR or urinary protein loss in nephrotic patients. Serum total and LDL-cholesterol and daily proteinuria were significantly lower at the end of both diet periods than at the beginning and at the end of the RUN-IN period. We suggest that these changes were a consequence of the manipulation of dietary fat intake.

Adult↗

Effect of dietary manipulation on the lipid abnormalities in patients with chronic renal failure.

Disorders of lipid metabolism could play an important role in mediating the progression of chronic renal disease toward uremia. The hypothesis of the nephrotoxicity of lipids has been considered in a large population of patients on long-term dietary protein restriction. In our experience, there is no evidence that lipid disorders may accelerate the progression of renal disease. Hypercholesterolemia and/or hypertriglyceridemia are probably only some of the many factors affecting the prognosis of renal disease. Dietary protein restriction seems to be effective in maintaining normal or only slightly elevated serum lipids in patients with early renal failure, even after years of dietary treatment, despite the natural progression of renal functional deterioration. Moreover, this dietary regimen has a favorable effect on lipid composition of erythrocyte membrane when compared with those of patients on a free diet.

Humans↗

Effects of ACE inhibition in normotensive patients with chronic glomerular disease and normal renal function.

A double-blind, placebo-controlled study was carried out to assess the effects of a three-month treatment with a new ACE inhibitor, Benazepril (BNZ), on systemic and renal hemodynamics, and urine protein excretion, in 20 patients with chronic glomerulonephritis, normal blood pressure (130/83 +/- 16/10 mm Hg), and normal renal function (creatine clearance 106 +/- 25 ml/min). Treatments with placebo or BNZ were assigned randomly. A wide range of proteinuria lowering effect was observed in overall population (from 1 to 84%, average 34%). Following the arbitrary level of a 30% reduction, two well-matched subgroups (10 patients for each one) were obtained: "good responders" (average decrease 51%), and "poor responders" (average decrease 17%). The main distinctive feature between the two groups was a higher plasma renin activity level in good than in poor responders. A positive correlation between the fall in proteinuria and blood pressure was found. Although the decrease in blood pressure seems to represent the major factor in determining the reduction in proteinuria, a multiple correlation analysis showed that the most prominent role (71%) was attributable to the combined decrease in blood pressure and filtration fraction, and then also to the efferent arteriole dilatation. Our conclusion is that ACE inhibitors are capable of also reducing proteinuria in patients with renal disease with normal blood pressure, the effect being more pronounced in those exhibiting humoral, systemic and renal hemodynamic patterns, indicating a greater activity of circulating and renal renin angiotensin system.

Adult↗