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Biomedical subjects

C Tozzo

Publications and source records attributed to C Tozzo.

28 records · Page 2Linked to original sources

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↗

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↗

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↗

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↗

[Prevention of tetanus in emergency and first aid services. Technical and organizational criteria].

The Authors emphasize the measures to be taken for tetanus prevention in an individually wounded patient. They have to be decided on the basis of: 1) A knowledge and understanding of the pathological process of tetanus; 2) The mode of action and limitations of the various preventive measures available; 3) The nature of the patient's wound; 4) The patient's history of tetanus immunization. The recommendations should therefore be regarded not as a set of hard and fast rules but as guidelines since, as with any scheme of general guidance on medical practice, they will not invariably cover the circumstances of all individual patients. In tetanus prevention it is of basic importance to establish and maintain active immunity by means of combined vaccines. Nevertheless, with availability of human tetanus immunoglobulins severe immunological reactions as anaphylactic shock are extremely unlike to occur. So that their use can be recommended in patients with tetanus prone wounds, who have not previously been given tetanus toxoid.

Emergency Medical Services↗

[Long-term clinical experience in post-dilution HFR].

PURPOSE: Hemodiafiltration reinfusion (HFR) is characterized by the use of regenerated ultrafiltrate as replacement fluid. We devised a new technique, post-dilution HFR, aimed at increasing the purification efficiency, treatment tolerability and at reducing inflammatory state. METHODS: We performed post-dilution HFR in six uremic patients during 18 months. Dialytic efficacy, filter blood rest and cytokine behavior were evaluated. RESULTS: Neither pyrogenic reactions nor other adverse phenomena were recorded. The tolerance to the treatment was excellent. We observed a high rate of urea extraction and optimal Kt/V values, a high extraction of beta2 microglobulin (beta2-m) and a reduction in blood rest; in addition, interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) significantly decreased. CONCLUSIONS. The inversion of the standard HFR configuration allowed us to improve the removal of both urea and beta2-m, and the blood rest, with an optimal tolerability. Moreover, the reduction in cytokine levels could attenuate the uremic microinflammatory state.

Adult↗

[Comparison between two different on-line dialytic techniques: Standard HFR vs post-dilutional HFR].

PURPOSE: Among hemodiafiltration (HFD) techniques, hemodiafiltration reinfusion (HFR) seems unable to achieve an optimal depurative efficacy. This study aimed to evaluate whether the HFR technique as suggested in its original configuration could be improved by devising a new technique (post-dilution HFR (PDHFR)) inverting the purification sequence to increase the purification efficiency of the entire system. METHODS: We performed standard HFR in six uremic patients during 6 months and, subsequently, during a further 6 months, PDHFR was performed. The dialytic efficacy of the two techniques and the filter blood rest were evaluated. In addition, we studied the behavior of cytokines during the inverted HFR sessions. RESULTS: We observed a significant increase in urea extraction and in Kt/V. An equally significant improvement was observed with regard to beta2-microglobulin (beta2-m) extraction and blood rest. Furthermore, interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) significantly decreased after inverted HFR treatment. CONCLUSIONS: The inversion of the original configuration allowed us to improve the depurative efficacy of standard HFR, increasing the removal of both urea and beta2-m, and reducing the blood rest. Finally, it was notable that the reduction in cytokine levels could attenuate the uremic microinflammatory state.

Adult↗

[Resistant hypertension and paradox effect in patient with hemodialysis treatment].

This is a case study of a 65-year-old female, on regular haemodialysis treatment, with resistant hypertension and paradoxical blood pressure (BP) elevation during dialysis. This phenomenon occurs in a small number of patients, since in most patients an acceptable BP is usually reached by adequate control of fluid and volume status with dialysis, sometimes associated with pharmacologic intervention. Since in our patient hypertension persisted despite apparent achievement of dry weight and maintenance of antihypertensive medications, we did some extensive investigations to disclose any secondary causes of hypertension (other than ESRD); we also evaluated whether the optimal dry weight was really achieved and maintained, and if the pharmacokinetics of the antihypertensive drugs was influenced by dialysis. We found no secondary cause of hypertension; by contrast, we detected the presence of a mild cardiac dilatation, and realized that some antihypertensive drugs, taken by our patient, were removed by dialysis. Since both these are known to precipitate the paradoxical BP rise during dialysis, we successfully modified once again our dialysis strategy and changed the antihypertensive therapy, adding a calcium antagonist to both losartan and low-dose minoxidil.

Aged↗