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Biomedical subjects

A Salvadeo

Publications and source records attributed to A Salvadeo.

At least 19 recordsLinked to original sources
PubMed1998

Dialysis hypersensitivity: a fading problem?

Allergic-type reactions experienced by patients on chronic hemodialysis are frequently reported in the literature, often related to compounds released during the hemodialysis sessions, in particular ethylene oxide (ETO). In these studies, dialysis patients seem to have higher values of IgE than those observed in a reference population. The aim of our work was to investigate IgE-related parameters of 126 dialysis patients in comparison with two control groups composed of healthy subjects and predialysis patients. IgE values were not significantly different in nonallergic dialysis patients, with a geometric mean (X) of 27.5 kU/l, when compared to healthy controls (X = 38 kU/l) and predialysis subjects (X = 40.7 kU/l). Higher values of IgE (X = 74.1 kU/l) were detected in allergic dialysis patients. However, only 3 patients, all without detectable antibodies against ETO, complained of anaphylactic symptoms during dialysis sessions in a 4-year surveillance period. At variance, 6 symptom-free patients carried IgE antibodies against ETO (range 0.7-15 kU/l), usually with high total IgE. Our results suggest a reduced frequency of hypersensitivity reactions during dialysis sessions. Furthermore, uremia does not alter IgE reactivity in the predialysis period or after long-term maintenance dialysis treatment.

Adult↗
PubMed1998

Levels of sustainable aerobic workload in dialysis patients.

The aerobic performance of a heterogeneous group of 89 ambulatory medically stable patients on chronic hemodialysis was studied to define individual levels of the most acceptable metabolic workload. The patients performed a step test protocol (3 steps) with a cycle ergometer. Each step (25 Watt) lasted 6 min. Heart rate (HR), oxygen consumption (VO2), ventilation (VE), respiratory exchange ratio (RER), blood pressure (BP) and subjective ratings of dyspnea (CRd) and fatigue (CRf) levels were monitored throughout the test. The test was continued to exhaustion or to values of systolic arterial blood pressure (SABP) >240 mmHg, heart rate (HR) > or = 85% max, or ST changes in ECG. In eleven patients (12.5% of the whole group) the test was interrupted within the first two minutes of exercise. In the remaining 78 patients, the maximum workload sustained for at least 3 min (MSW) was 25 Watts for 43 (48.5%), 50 Watts for 27 (30%), and 75 Watts for 8 (9%) patients. Performance was affected in a statistically significant manner by the subjects' anagraphic age, but not by their dialytic age, hemoglobin (Hb) level or weight. Individual levels of tolerable workload were estimated for 60% of the group from the stability of physiological variables during 3 min, and from subjective ratings at a "moderate" level. This level corresponded to an average of 3.5+/-0.9 METs, at 60% of the HRmax, with a mean BP of 167+/-21/98+/-14 mmHg. This could become a safe starting point for a program of physical retraining.

Adult↗
PubMed1997

Altered muscle energy metabolism in post-absorptive patients with chronic renal failure.

Skeletal muscle biopsies were performed on 12 healthy sedentary subjects and on 22 non-dyalized chronic renal failure patients (CRF) on a free diet and after overnight fasting. Parathormone, glucagon and insulin were determined at the same time of biopsies. CRF patients showed significantly low ATP and creatine phosphate levels. Regarding enzyme activities, a high hexokinase Vmax was found, while the pyruvate kinase activity was lower than in the control group. For the tricarboxylic acid cycle, citrate synthase, succinate dehydrogenase and malate dehydrogenase activities were higher; total NADH cytochrome c reductase activity was also high, while cytochrome oxidase activity was slightly lower. Both alanine aminotransferase and aspartate aminotransferase activities were considerably high in comparison with the control group. In conclusion, our study revealed a hypermetabolic TCA cycle, but impaired oxidative phosphorylation, which partly explained the reduced ATP concentration. Excessive protein intake and hormonal derangements may play a role in these metabolic changes.

Adenosine Triphosphate↗
PubMed1995

Uraemic pruritus is not related to plasma histamine concentrations.

Pruritus is a common symptom in uraemic patients and its aetiology is poorly understood, although several factors have been implicated, including high histamine plasma levels. The aim of the study was to evaluate plasma levels of histamine in patients on maintenance haemodialysis in relation to the presence of itching (35 pruritic patients = group A; 50 non-pruritic patients = group B). Furthermore, we compared the values obtained with those of a healthy control group (64 subjects). We observed increased plasma histamine levels in uraemic patients compared with healthy controls. However, no relationship was found between plasma histamine values and itching because groups A and B showed overlapping values and there was no correlation between the intensity of pruritus and plasma histamine concentrations in group A patients. In conclusion, we suggest that there is no evidence for plasma histamine playing a significant part in uraemic pruritus.

Adolescent↗
PubMed1993

Variations in erythropoiesis and serum ferritin during erythropoietin therapy for anaemia of end-stage renal disease.

In order to study the relationship between erythropoiesis and serum ferritin (SF) during erythropoietin (rHuEPO) therapy in the anaemia of end-stage renal disease (ESRD), 19 patients were followed without iron supplementation and at a fixed dose of the drug (40 U/kg). Twelve patients failed to attain the target haemoglobin (Hb) value, 7 of whom due to the appearance of iron deficiency. Erythropoiesis, as measured by the serum transferrin receptor concentration, increased from 12 to 120% of the basal value. This increment was not constantly associated with a proportional rise of Hb or reticulocyte count. SF decreased exponentially from a median value of 221 micrograms/dl (range 42-470) to a median value of 54 micrograms/dl (range 20-172). Halving of the basal SF value (SF-T50) was reached at the 18th-95th day of therapy (median = 43), representing a iron shift of 3.4-11.6 mg/day (median = 5.4). SF-T50 was not correlated with the Hb increase, but with that of erythropoiesis (r = 0.78; p = 0.003). The minimum SF (MSF) value attained was not correlated with the appearance of iron deficiency. The conclusion is that the rate of SF decrease during rHuEPO in ESRD is a reliable measure of iron mobilisation for erythropoiesis, but not for haematologic response. The MSF value reached during therapy is not representative of available iron for erythropoiesis.

Adolescent↗
PubMed1992

Pharmacokinetics of nicorandil in patients with normal and impaired renal function.

The pharmacokinetics of oral nicorandil 20 mg 12 hourly for 9 doses was evaluated in 21 hospitalized patients with angina pectoris due to coronary heart disease and with normal and impaired renal function. Patients were divided into 3 groups based on creatinine clearance (CLCr): GROUP I (n = 6) greater than 80 ml/min, GROUP II (n = 8) 20-80 ml/min, and GROUP III (n = 7) less than 20 ml/min. After the first dose, the total clearance of nicorandil (CL) value did not change with increasing renal failure and so was not dependent on creatine clearance. After the last dose CL was 51 l.h-1 in Group I, 44 l.h-1 in Group II and 56 l.h-1 in Group III, and it was not related to creatinine clearance. The percentage of the dose excreted in the urine was 0.4%. No significant difference was noted in any of the other pharmacokinetic parameters examined in the three groups, not even on comparing values obtained on the first and last days of treatment. The findings suggest that there is no need to change the dose of nicorandil in subjects with different degrees of renal failure.

Administration, Oral↗
PubMed1992

Recombinant human erythropoietin reduces free erythrocyte protoporphyrin levels in patients on chronic dialysis.

We studied the significance of free erythrocyte protoporphyrin (FEP) in relation to iron status, aluminum levels and anemia in uremic patients on chronic dialysis. All but 1 patient showed high FEP values closely related to the degree of anemia. Increased FEP levels are due to a defective heme synthesis, not related to iron deficiency or aluminum overload. Treatment of anemia with recombinant human erythropoietin reduced FEP values. We therefore hypothesize that recombinant human erythropoietin ameliorates an enzymatic defect in heme synthesis.

Aluminum↗
PubMed1992

High prevalence of antibodies to hepatitis C virus in hemodialysis units using a second generation assay.

We studied the prevalence and significance of antibodies to hepatitis C virus (HCV) in patients and staff from 3 dialysis units, using a 2nd generation assay (2nd g.a.; Ortho HCV). Of 277 patients, 151 (55%) were positive by 2nd and 85 (31%) by 1st g.a. Significant associations with the anti-HCV carrier status were: blood transfusions, retrospective finding of elevated ALT and duration of dialysis treatment, independently of transfusions. Of the 74 staff members, 5 were positive by 2nd and 3 by 1st g.a. Our data suggest that the 2nd g.a. is more sensitive in detecting HCV exposure in dialysis units and that duration of dialysis is a significant factor in acquiring HCV infection.

Ambulatory Care Facilities↗