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Biomedical subjects

D Scorza

Publications and source records attributed to D Scorza.

16 recordsLinked to original sources
PubMed1995

Reduced blood levels of coagulation inhibitors in chronic hemodialysis compared with CAPD.

The aim of this study was to measure the coagulation inhibitors in two groups of uremic patients treated with hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) to evaluate the differences in anticoagulant activity. In 20 patients on HD and 20 on CAPD, mean age 66 +/- 8 and 58 +/- 14 years, respectively, the following parameters were determined between dialysis exchanges: protein C (PC), protein S (PS), antithrombin III (AT III), electrophoresis, prothrombin activation fragment (F1+2), alpha 1 antitripsin (alpha 1 AT), prothrombin time (PT), and activated partial thromboplastin time (PTT). The mean values of PC, PS, and AT III were respectively, 95.7 +/- 16 on HD and 92 +/- 23 on CAPD; 82.2 +/- 13.6 on HD and 90.5 +/- 13.6 on CAPD; the mean value F1+2 was 1.2 +/- 0.5 on HD and 1.04 +/- 0.5 on CAPD (p < 0.05). A good correlation between PS and AT III% functional activity (p < 0.03, r = 0.5) in both groups was found. More-over, PS functional activity was inversely correlated with duration of dialysis (p < 0.05, r = -0.3). HD patients showed a reduction of coagulation inhibitors compared with CAPD patients. Such a phenomenon could justify the increased thrombotic risk in HD patients. Since 80% of those on HD and only 20% of those on CAPD received erythropoietin (EPO), the prothrombotic state in HD could be due to reduced PS activity secondary to EPO treatment.

Aged↗
PubMed1992

Prevalence of hepatitis C virus antibodies in hemodialysis patients in the area of Milan.

We studied the seroprevalence of antibodies to hepatitis C virus (HCV Ab) in a cohort of 229 chronic hemodialysis patients followed by 6 Dialysis Units in the Milan area. HCV Ab was present in 51 (22.3%) of 229 examined patients. Previous blood transfusions and surgery did not clearly influence HCV seroconversion, whereas duration of dialysis treatment seems to be strictly related to HCV Ab positivity.

Adult↗
PubMed1990

HIV-associated nephropathy: a new entity. A study of 12 cases.

The existence of an HIV-related nephropathy as a distinct disease entity is controversial. Twelve patients affected by HIV infection (eight drug-abusers, three homosexuals and one black heterosexual) who showed nephrotic syndrome (five patients) or urinary abnormalities (seven patients), four with renal insufficiency, were submitted to renal biopsy. Six patients were in pre-AIDS, six had AIDS. Light microscopy, performed in all cases, showed focal segmental glomerular sclerosis in nine patients, a moderate hypercellularity in six, vacuolisation of visceral epithelium in ten, focal collapsed tuft in seven, and tubular microcystic dilatation with large dense protein casts in lumina in seven. Immunofluorescence, available in 11 patients, showed small deposits in mesangium or mesangial and subendothelial spaces. IgG, IgM, and C3 were more frequently found, while three cases were negative. Electron-microscopy (five patients), besides confirming light-microscopy changes, showed several tubuloreticular inclusions (four patients), nuclear bodies (mainly complex) in nuclei of tubular cells (three patients), and nuclear granulofibrillary transformation of tubular cells. Various histological aspects and clinical data confirm the hypothesis that HIV nephropathy can be considered as a separate entity, different from heroin nephropathy and idiopathic focal glomerulosclerosis.

Adult↗
PubMed1989

Cardiac output with CO2 rebreathing method in CAPD patients.

The aim of this study is to evaluate cardiac output (CO) with CO2 rebreathing method (RCO2) in patients (pts) on CAPD. We have studied 15 pts on CAPD from at least 6 months, the mean (+/- SD) age was 55 +/- 4 years, mean (+/- SD) hemoglobin was 10 +/- 2 gr/dl. The respiratory tests excluded obstructive or restrictive broncopneumopathies. Electrocardiograms and B-mode echocardiograms were normal. RCO2 was evaluated using the FICK formula: CO = VCO2/CvCO2 - CaCO2 where VCO2 is CO2 production; CvCO2 is the CO2 content in venous mixed blood; CACO2 is arterial CO2. VCO2 was obtained by collecting expired air into a Douglas bag during respiration at rest for 4 minutes. CvCO2 was obtained after 10-15 seconds of respiration in a mixture of 7% CO2 in O2. CaCO2 was obtained at CO2 end-tidal capnogram. RCO2 was performed in CAPD with full and empty abdomen. The mean (+/- SD) CO was 2.3 +/- 1.04 l/min with both full and empty abdomen, values below those theoretically calculated, taking into account the age and body surface (4.7 +/- 0.6 l/min P less than 0.0005). The reduction of CO is not induced by left ventricular insufficiency, but such phenomenon could be attributed to a redistribution of body fluid between intra and extracellular, in favour of the intracellular compartment. Therefore the increase in hematocrit and total plasma proteins can be fictitious.

Aged↗
PubMed1986

Clearances and solutes extraction in biofiltration and hemodialysis with the AN 69 S.

Clearances and solutes extraction were assessed in biofiltration (BF) and in hemodialysis (HD) with the new polyacrylonitrile AN 69 S membrane. Three patients treated for three months by acetate dialysis (4 hours X 3) and subsequently by BF (3 hours X 3) were studied after achievement of steady state. Total intradepurative clearances (diffusive and convective) and solutes extraction of urea, creatinine, uric acid and phosphate were determined. Clearance of small molecular weight solutes was better in BF than in HD especially for uric acid and phosphate. This confirms the high depurative efficiency of the AN 69 S. BF gave better total clearances than HD, but the extraction of lower molecular weight solutes (due to the one-hour reduction of dialysis time) suggests that adequate treatment time is needed with this technique.

Acrylic Resins↗
PubMed1985

Haemofiltration without substitution fluid.

Haemofiltration at its best is able to give excellent clearances of solutes in a wide molecular weight range, but the need of large amounts of reliable substitution fluid makes this technique too expensive for more widespread application. In order to give an 'adequate' treatment by a safe, well tolerated, effective and comparatively cheaper method, haemofiltration without substitution fluid (HWSF) has been carried out. This method, consisting of the regeneration of appropriate amounts of pure convected plasma water by highly permeable, high surface area dialysis membranes, has been utilised for several months in four patients, with encouraging clinical results.

Adult↗
PubMed1984

Evidence for a role of a serum factor stimulated by metoclopramide in regulating aldosterone secretion.

The stimulatory effect of metoclopramide upon aldosterone secretion is independent of the known aldosterone-regulating mechanisms (renin, potassium, adrenocorticotropic hormone), is unrelated to its effect on prolactin and is absent when metoclopramide is directly added to isolated adrenal zona glomerulosa cells. To examine the possibility of a "humoral" mediation of aldosterone stimulation by metoclopramide, we evaluated the effect of serum of 10 normal subjects injected with metoclopramide (10 mg i.v.) on aldosterone production by collagenase-dispersed calf adrenal zona glomerulosa cells. Whereas no effect was observed with serum collected before the injection, serum collected from 5 to 30 min after the injection stimulated aldosterone production. The effect was seen 2.5 min after the injection, was significant at 5 min (P 0.05), 10, 15, 20 and 30 min (P 0.01). The effect disappeared 40 min after the injection, when plasma aldosterone in subjects was still elevated (P 0.01). The biological half-life of the factor (t1/2) is about 12.5 min. A significant correlation was found between the maximal aldosterone response to metoclopramide in vivo and the maximal effect of serum in vitro (r2=0.69;P 0.01). We suggest that metoclopramide stimulates aldosterone production in vivo by the increase in serum of a factor which, in turn, stimulates aldosterone and whose physiological significance remains to be evaluated.

Adrenal Glands↗
PubMed1984

Effects of potassium supplementation on insulin binding and insulin action in human obesity: protein-modified fast and refeeding.

To investigate the role of potassium deficiency in the development of glucose intolerance during caloric deprivation, potassium balance was maintained within normality with oral potassium supplementation in a group of obese subjects who underwent protein-modified fast and the results of the study of carbohydrate metabolism (oral glucose test, insulin receptors on monocytes and peripheral glucose utilization as assessed by euglycaemic clamp) were compared with those obtained in a group of obese subjects admitted to protein-modified fast without potassium supplementation. Caloric deprivation without oral potassium supplementation was followed by a negative potassium balance and a decrease of serum potassium levels; a decrease of the peripheral levels of insulin along with an increase in insulin receptors and a striking reduction of peripheral glucose utilization were also observed. The maintenance of normal potassium balance and normal serum potassium levels with oral potassium-chloride supplementation was associated with higher peripheral levels of insulin (P less than 0.01) and improvement of peripheral glucose utilization (P less than 0.01) whereas the binding of insulin to monocytes was unchanged. The data suggest that potassium depletion during protein-modified fast causes a decrease of the peripheral levels of insulin and a resistance to insulin action at the postreceptors sites which is reversed by potassium supply.

Adult↗
PubMed1984

Serotonergic regulation of cortisol secretion in dogs.

The role of serotonin (5-HT) in the control of serum cortisol secretion was studied in 50 conscious beagle dogs. A significant rise in corticosteroids was observed after 1.5 and 3 mg/kg (P less than 0.01) iv fenfluramine, an indirect serotonergic agonist, as well as after 2 (P less than 0.05) and 3 mg/kg (P less than 0.01) iv quipazine, a direct agonist of 5-HT receptors. Both drugs exhibited a dose-related effect. A lower dose of fenfluramine, 0.5 mg/kg, was ineffective when administered iv, but raised serum cortisol (P less than 0.05) after direct injection into a lateral cerebral ventricle, through a chronically implanted brain cannula. The marked increases in corticosteroid concentration produced by the highest fenfluramine and quipazine doses were completely abolished by pretreatment with ketanserin, an antagonist of 5-HT2 receptors, which did not affect cortisol secretion when administered alone. These data suggest that brain serotonergic system plays a role in the control of cortisol secretion in conscious dogs.

Animals↗
PubMedDate not supplied

In vitro steroidogenic properties of FK 33 824, a stable analog of methionine-enkephalin. Opiate-dopamine interaction in the control of aldosterone production.

The steroidogenic properties of a stable analog of the endogenous opioid methionine-enkephalin, FK 33 824, were studied with calf adrenal glomerulosa cells and its effects were compared to those of angiotensin II (A II) and metoclopramide. Metoclopramide, A II, and FK 33 824 induced dose-related increases in aldosterone production. The order of potency in stimulating aldosterone was A II, FK 33 824, metoclopramide. Metoclopramide and FK 33 824 did not increase cortisol production. The response to A II but not to FK 33 824 was inhibited by equimolar concentrations of (Sar1 Ala8) antagonist analog of AII (saralasin acetate). By contrast in the presence of equimolar concentrations of naloxone, an opioid receptor antagonist, FK 33 824-induced aldosterone production was markedly inhibited while the response to A II was unchanged. Increases in cAMP accompanied the steroidogenic response to ACTH but not to A II or FK 33 824. Dopamine at physiological concentrations (10(-10) M) inhibited FK 33 824-induced aldosterone production. These results suggest that FK 33 824 is an aldosterone secretagogue and that it initiates steroidogenesis by mechanisms similar to those of A II. However the inability to block its effect with a specific antagonist of A II provides evidence for its action on a separate site.

Adrenal Glands↗
PubMedDate not supplied

HIV infection in dialysis centers in Italy: a nationwide multicenter study.

The prevalence of HIV infection in dialysis populations varies according to different countries and geographic areas. We performed a nationwide epidemiological study by means of a questionnaire in the period from January 1990 to December 1995. Questions were about whether and which HIV tests were performed and which preventive measures were adopted. A separate survey evaluated the data the HIV-positive patients. Only 62% of the centers responded to the questionnaire, corresponding to 21,500 dialysis patients in 1990 and 27,000 in 1995. The prevalence of HIV-positive subjects was 0,13% for 1995. A total of 48 patients with HIV infection were identified: risk factors were drug abuse in 16 cases, homosexuality in 9, heterosexual contact in 8, transfusion in 7, renal transplant in 3 and unknown cause in 5. Forty-five patients were on hemodialysis, and 3 were receiving peritoneal dialysis. At follow-up, 19 patients died: infection and malnutrition were the most frequent causes of death. The death rate of patients who were already HIV positive when dialysis was started (group 1, 29 cases) was 19.36 deaths/1,000 patient/month. The correlations, performed only for group 1, showed a significantly worse prognosis for patients with CD4 < 200/mm3 and for those with AIDS. In conclusion, in Italy the prevalence of HIV infection in the dialysis population is low, and the outcome of HIV-positive patients in dialysis was found to be better than earlier literature reports. The use of chronic dialysis for HIV patients with uremia should not be discouraged.

AIDS Serodiagnosis↗