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Biomedical subjects

C Meloni

Publications and source records attributed to C Meloni.

At least 55 records · Page 3Linked to original sources
PubMed1988

Patellofemoral dysplasia in infantile cerebral palsy.

The authors have studied the biomechanical basis of functional alterations in the extensor apparatus of the knee in cases of infantile cerebral palsy. Several interesting aspects of the problem, some of which are controversial, have emerged from this study and from a review of patients with flexion contracture of the knee treated surgically: 1. The neurological pathology of the motor system leads to problems of posture and dysplastic conditions of the hip (coxa valgus, etc.) which favour the development of patellofemoral pathology. 2. By contrast, the early clinical manifestations of this pathology are relatively insignificant and completely overshadowed by the major problems of adaptation and compensation imposed by the more serious overall disabilities which face the patient in order to stand and walk. The knee plays a prevalently static role at this stage and is not particularly stressed during joint movement. 3. The clinical manifestations of patellofemoral pathology are thus paradoxically brought into focus by surgery on the flexor apparatus to deal with contracture. Although on the one hand this improves function, on the other it brings to light the more complex functional mechanisms of the knee, thus emphasizing any deficit in the extensor apparatus.

Biomechanical Phenomena↗
PubMed1987

NMR spin-lattice relaxation times of intracellular Na-23 on rat livers and related lipid peroxidation following CCl4 intoxication.

Liver tissues were isolated from rats acutely intoxicated with carbon tetrachloride, and Na-23 NMR signals were analyzed to investigate the T1 relaxation times of intracellular sodium ions under pathological conditions in presence of the paramagnetic shift reagent (dysprosium tripolyphosphate). We studied the significant increase of T1 found in CCl4 treated rats with respect to controls, which was elsewhere demonstrated as being independent of cell necrosis. Evidence is given that neither fat accumulation nor proliferative processes affect the observed T1 lengthening. When T1 relaxation times were measured in the liver of vitamin E treated rats subsequently intoxicated with carbon tetrachloride, a significative shortening of T1 with respect to CCl4-intoxicated rats was observed. These results were discussed in terms of the antioxidant action exerted by vitamin E, taking into account that peroxidation of microsomal lipids is the key factor in the process of carbon tetrachloride induced liver injury. Furthermore, the observed T1 changes were discussed in terms of the interactions of Na+ with cell membranes and/or the occurrence of viscosity changes.

Carbon Tetrachloride Poisoning↗
PubMed1987

Risk of iron overload and 'hemochromatosis allele(s)' in patients on maintenance hemodialysis.

In the present study, we have evaluated the relationship between serum ferritin (SF) levels, 'hemochromatosis allele(s)', blood transfusions and iron parenteral administration in 69 hemodialysis patients. We demonstrated significantly higher SF levels in patients with hemochromatosis allele(s) (HA+) than in patients without hemochromatosis alleles (HA-). In addition, HA+ patients who had received blood transfusions up to 15 months prior to the study had SF levels even higher than those without blood transfusions. On the other hand, HA- patients had normal levels of SF, independent of blood transfusions. After intravenous administration of 1 g iron saccharate, SF levels were significantly higher only in HA+ transfused patients. In conclusion, our study demonstrated that HA+ patients are at a higher risk of iron overload and therefore the use of transfusional and/or parenteral iron should be strictly limited.

Adolescent↗
PubMed1987

Red blood cell lipid peroxidation in predialysis chronic renal failure.

In hemodialysis patients the pentose-phosphate shunt activity is deficient. As a consequence, the lipid peroxidation of the erythrocyte membranes is increased as shown by the increase in malonyldialdehyde concentrations and is accompanied by a decrease of the level of vitamin E in RBC. In the present study we have found that increased lipid peroxidation of the erythrocyte membranes is present also in chronic renal failure patients in the predialysis state, provided that the serum creatinine levels are higher than 5 mg/dl.

Erythrocyte Membrane↗
PubMed1986

Correction of uremic acid-base imbalance in biofiltration: standardization of the amount of bicarbonate infused.

Beneficial effects of biofiltration on acid-base balance have been described, especially in patients showing poor tolerance to standard hemodialysis. This study was designed to standardize the amounts of bicarbonate to be infused for optimal control of the acid-base balance, without the adverse reactions of symptomatic metabolic alkalosis. In three adult patients (body weight greater than 55 kg) a 300 mEq. bicarbonate infusion achieved normal pre- and post-dialysis plasma levels of bicarbonate and normal pre- dialysis pH. Conversely, in three adolescent patients (body weight less than 40 kg) pre- dialysis plasma bicarbonate levels and pre- dialysis pH could not be adequately corrected in spite of increasingly high doses of bicarbonate infused up to a maximum of 240 mEq per treatment. Larger amounts brought on symptoms of metabolic alkalosis.

Acid-Base Imbalance↗
PubMed1986

Clinical evaluation of biofiltration in uremic patients undergoing chronic hemodialysis.

The clinical efficiency of biofiltration (BF) was evaluated in six hemodialysis patients with poor clinical tolerance for standard hemodialysis. Three were adults (mean age 34 years, mean body weight 67 kg) and three adolescents (mean age 17 years, mean body weight 38 kg). Mean maintenance hemodialysis time was 90.5 months (range 49-132). BF treatments lasted three hours in all cases, for a total of nine hours weekly, with AN69 S membranes and infusion of 3 liters of HCO3 solution (100 mEq/l for the adults, 80 mEq/l for the adolescents). We recorded intra- and inter-dialytic symptoms daily, hematological values and acid-base status monthly. Multimodality evoked potentials were recorded after 3 and 9 months. Biochemical values reached a steady state 9 months from the beginning of the study, metabolic acidosis was corrected more efficiently in both groups at the end of dialysis, but only in the adult patients, were pre-dialysis plasma bicarbonates within normal limits. A clear drop in the number of episodes of intradialytic hypotension was noticed in both groups, but the adolescent patients' tolerance for dialysis did not improve. In conclusion our data show that in adult patients with poor tolerance BF offers a dependable alternative to standard hemodialysis, and the length of treatment can be reduced.

Acid-Base Equilibrium↗
PubMed1985

Pentose-phosphate shunt activity and red blood cell malonyldialdehyde levels in haemodialysis and in CAPD patients.

The baseline concentrations of MDA in the RBC membranes and the MDA production in the erythrocytes following stimulation with ascorbate and cyanide are compared in a group of uraemic patients on chronic haemodialysis and in one treated with CAPD. Lower baseline concentrations and smaller production of MDA following in vitro stimulation, point to a better function of the pentose-phosphate shunt in CAPD patients than in haemodialysis.

Adolescent↗
PubMed1985

Red blood cell membrane lipid peroxidation and chronic haemolysis in haemodialysis patients.

Pre dialysis concentrations of malonyldialdehyde (MDA) in the red blood cell membranes and pre and post dialysis percent variation of plasma haemoglobin levels are studied in a group of uraemic patients on maintenance haemodialysis both before and after a therapeutic trial with vitamin E. The findings show a significant correlation between MDA levels and percent variation of plasma haemoglobin during dialysis, thus indicating that reducing the amount of lipid peroxidation can help to reduce intradialytic chronic haemolysis.

Adolescent↗
PubMed1985

Use of a thymic factor in the prevention of postoperative infections.

A controlled study was carried out on 60 patients undergoing laparotomy to assess the role of a thymic factor (TP-1 Serono) in the prevention of postoperative infections. All patients entering the study were preoperatively shown to be at risk of sepsis on the basis of the response to skin multitest system for assay of delayed hypersensitivity (Multitest C.M.I. System). The patients were also postoperatively monitored with the same system. The lower incidence of infections in patients treated with the thymic factor with respect to untreated patients (p less than 0.05) and the postoperative response to skin tests have confirmed the efficacy of the thymic factor under study in the prevention of postoperative infections.

Adjuvants, Immunologic↗
PubMed1983

Transfused and pharmacological iron: relationship of overload to HLA antigens.

Forty-eight haemodialysis patients were divided in two groups according to presence or absence of haemochromatosis alleles (HA). Serum ferritin concentrations were determined and analysed according to blood transfusion history. Furthermore 20 patients were given iron saccarate and post treatment ferritin concentrations were determined at 15 and 30 days. Following blood transfusion, only HA+ patients increased ferritin concentrations, while intravenous iron administration produced increased ferritin both in HA+ and HA- patients. Therefore it is advisable to minimise transfusions in HA+ patients, while intravenous iron administration should be avoided regardless of HA status.

Adolescent↗
PubMed1982

Evaluation of acid-base balance and pO2 with acetate dialysis in non-uremic patients.

The aim of our work was to evaluate the immediate effects of acetate-dialysis in patients with normal renal and respiratory function. For this purpose pH, pO2, pCO2 and HCO3- were monitored in arterial blood before dialysis, after 60, 120, 180 mns and at the end of each treatment in two groups of patients on chronic hemodialysis, a first group of schizophrenic patients and a second group of uremic patients. In the first group of patients the predialytic values were in the normal range. After hemodialysis HCO3- and pCO2 significantly decreased, both these changes were associated with a stable pH. The pO2 significantly decreased after 60 mns of dialysis. At the end of dialysis the pO2 increased without significant variation compared to predialytic values. In conclusion in non-uremic hemodialysis patients metabolic acidosis due to the loss of bicarbonate through the membrane is compensated by respiratory alkalosis. This respiratory alkalosis is not due to hypoventilation secondary to respiratory centre inhibition, but is mainly due to the pCO2 loss through the dialysis membranes.

Acetates↗