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Biomedical subjects

A Albertazzi

Publications and source records attributed to A Albertazzi.

At least 73 records · Page 4Linked to original sources

Polycentric 384-month study of biofiltration (BF) with AN69s.

Polycentric 384-month study of biofiltration (BF) with AN69s. Since January 1984, 39 uremic dialyzed patients have been included in a randomized prospective study, to evaluate the clinical utility of BF. The trial lasted 9.85 months/pt (384.15 months of total observations) and patients admitted had some not well controlled clinical signs: major acidosis, intradialytic cardiovascular instability, intolerance to acetate dialysis, hypercatabolism, neuropathy, etc. We obtained some positive effects: the incidence of intradialytic hypotension decreased 26.6%; interdialytic body weight gain fell from 3.1 to 2.7 kg (p less than 0.05) and the dialytic time per week was reduced from 12.3 to 10.0 hours (p less than 0.01). At the same time dry body weight increased from 62.4 to 64.6 kg with worthwhile improvement of the acid-base status (ABS) in all patients. This controlled trial showed that BF is particularly useful for patients suffering from severe acidosis and/or cardiovascular instability.

Acidosis↗

Effects of chronic biofiltration with PAN membranes on acid-base status: polycentric study.

Effects of chronic biofiltration (BF) with PAN membranes on acid-base status (ABS): polycentric study. From the 39 cases in a polycentric study we selected 13 patients with metabolic acidosis (pH 7.23 +/- 0.03), marked reduction of plasma bicarbonate (15.4 +/- 2.2 mEq/l) and hyperkalemia (6.2 +/- 0.6 mEq/l). BF was performed with a continuous post-dilutional supply of HCO3 (85 mmol/h), and attained rapid normalisation of blood bicarbonates and serum potassium during the treatment. After 6 months of BF treatment the pre-dialytic ABS showed remarkable improvement, and values were normal after one year. The remaining 26 patients in the polycentric study, treated by chronic BF without severe acidosis, showed good dialytic tolerance. In 15 of them the supply of bicarbonate was too high (because of moderate post-BF alkalosis) and we had to reduce the buffer inflow to about 50 mmol/h.

Acid-Base Equilibrium↗

Nucleotide deficit and functional platelet alterations in patients on regular dialysis treatment (RDT).

In RDT patients hemocoagulative changes are repeatedly found; of these the most important are platelets' functional defects. Biochemical and biophysical modifications responsible for this pathology have not been completely clarified. In 20 non-thrombocytopenic patients, dialyzed 3 times weekly for over 1 year, we evaluated, using standard methodology, platelet adhesivity and aggregation induced by collagen and ADP at varying dosages. All blood samples were collected after the longest interdialytic period and just before dialysis. At the same time we evaluated the basic metabolic pool and, after collagen stimulation, the intraplatelet functional storage pool of ATP and ADP. The dosages were obtained using simple, reproducible and modern bioluminescence technique, which utilises microorganism light emission (bioluminescence) due to the oxidation of the bacterial substrate by catalyzing enzyme (luciferase) (1251 Luminometer LKB). We compared this data with that obtained from 40 healthy subjects. In the patients examined, adhesivity and aggregation result altered. The intraplatelet content of all nucleotides in both pools is significantly reduced if compared to the control group. The ATP and ADP concentration of both metabolic and functional pools cannot be correlated to the following: serum creatinine, BUN, calcemia, PTH, Hb. On the contrary we found that basal metabolic ATP values are inversely related (p less than 0.01) to serum phosphate levels. An analysis of results of this preliminary study leads us to hypothesize that hyperphosphatemia could interfere with intraplatelet glycolysis inducing a reduction of intracellular ATP. As all platelet functions are ATP and ADP dependent, we could consider the nucleotide deficit a cause of "uraemic platelet" disfunction, not modifiable with RDT but perhaps only through an appropriate control of phosphate levels.

Adenosine Diphosphate↗

Intraocular pressure (IOP) changes induced by regular dialysis treatment (RDT).

It has been long known that uremia and RDT could alter the optical fibers of the Central Nervous System: we also previously demonstrated the persistence of a delayed P100 wave evoked by Visual Potentials (VEPs) in RDT patients. Our present study evaluates changes in IOP during RDT and possible correlations between electrophysiological and tonometrical modifications. In twenty patients undergoing RDT (12 hrs/weekly, mean age 42.05 +/- 10.80 yrs) we performed, just before and immediately after the dialytic session the tonographic recordings and serum osmolality. The pre-dialysis IOP of all 20 patients ranged from 9.00 to 27.19 mmHg with a mean of 16.40 +/- 7.20. Serum osmolality predialysis was 326.10 +/- 5.72 mOsm/l and post-dialysis 290.33 +/- 2.95 mOsm/l. Our studies suggest a correlation between decrease in plasma osmolality and increase in IOP during dialysis. The effect of RDT on IOP depends on the balance between the rise in IOP with the reduction of the concentrations of "waste products" and the extracellular volume reduction associated with ultrafiltration. The elevation of IOP may be due to a decrease in post-dialysis outflow facility inducing an osmotic influx of water into the eye because of hyperosmolality of intraocular fluids. These continuous modifications may be partially responsible for the defective propagation and the delayed transmission documented by VEPs.

Adult↗

Evoked potentials in uremia: basal and follow-up data.

Various EPs have been employed to disclose even early-stage central and peripheral nervous system damage in uremia. This approach also gives the possibility to follow up alterations of many sensory functions during the sequential stages of uremia. Fifty-three subjects (35 male and 18 female, mean age 42.20 +/- 5.50 yrs, conventionally low nitrogen diet treated, on dialysis or transplanted) were followed-up by recording the EPs every year for seven years. The P100 wave latency and amplitude of VEPs were recorded and found abnormal in about 70% of the examined visual systems. The auditory EPs were abnormal in 53% of the cases for the peak latencies, interpeak times and peak ratios. The somatosensory EPs showed in 75% of the cases an altered latency and morphology of the waves registered in the lumbar, cervical and cranial loci. There is evidence suggesting that evoked cerebral biorhythms may provide sensitive and objective indexes of cerebral function in uremia. The persistence of abnormalities disclosed by EPs follow-up confirm the reliability of this technique in evaluating neuro-pathologic uremic situations and in supplying optimal uremia therapies.

Adult↗

Present status of hemoperfusion/hemodialysis in Italy.

The use of charcoal hemoperfusion in the treatment of chronic renal failure has been proposed and applied by several authors. The availability of coating membranes of increased biocompatibility currently allows a safer and wider use of this purifying technique. It has been recently demonstrated that long-term treatment with combined hemodialysis/hemoperfusion yields an improvement of certain dialysis-resistant uremic signs in patients on regular dialysis treatment, while in selected patients it affords a marked reduction (up to one-third) in the overall time of treatment per week. The tolerance of long-term treatment is good. In line with these findings, a multicenter study has been carried out in Italy with two main aims: (1) to see whether long-term treatment with charcoal hemoperfusion is really safe and substantially free from side effects; (2) to verify in a larger and more varied population of patients whether such long-term treatment actually improves certain uremic signs persisting despite adequate dialysis treatment. A third phase of the multicentric study (reducing the weekly time of treatment) is currently being worked on. Five nephrology and dialysis departments took part in the study: in Bologna, Rome, Chieti, Ancona, and Lecce.

Clinical Trials as Topic↗

Endocrine-metabolic effects of l-carnitine in patients on regular dialysis treatment.

Twenty-three patients on regular dialysis treatment (RDT) were given 1-carnitine orally or in dialysate for six months. All patients remained in a stable biochemical state; hyperlipidaemia was reduced with an increase in HDL-cholesterol. Hormonal pattern was unmodified. Serum and muscle carnitine and acetylcarnitine constantly increased. L-carnitine in RDT, by restoring tissue reserves, improves metabolic alterations without any side-effects.

Acetylcarnitine↗

Multicentric experience with combined hemodialysis/hemoperfusion in chronic uremia.

A multicentric study was carried out to investigate the safety and effectiveness of long-term treatment of chronic uremic patients by a regular combination of hemodialysis and charcoal hemoperfusion. 39 RDT patients from five dialysis centers were treated for up to 12 months. The combined treatment proved to be safe, well tolerated and effective in improving certain dialysis-resistant uremic signs, mainly severe peripheral neuropathy, asthenia, anorexia, nausea, lack of well-being and relapsing pericarditis. There was also a marked decrease, after several weeks of combined treatment, in plasma values of urea, uric acid and creatinine.

Adult↗

New electrophysiological assessments for the early diagnosis of encephalopathy and peripheral neuropathy in chronic uraemia.

The clinical manifestations of neuropathy in chronic uraemia are late in occurring. However, at an early stage it is possible to detect damage to either the central or peripheral nervous system by means of modern electrophysiological investigation methods. We examined 29 patients with CRF (plasma creatinine 7.0 +/- 4.0 mg%) on conservative diet. The following electrophysiological tests were carried out at least once: Electroencephalogram (EEG), Electromyogram (EMG), Motor Nerve Conduction Velocity (MNCV), Sensory Nerve Conduction Velocity (SNCV), Visual Evoked Potentials (VEPs) using the pattern reversal transient stimulation method. At the same time the following blood tests were performed: BUN, creatinine, uric acid, glucose, cholesterol, triglycerides, lipid electrophoresis, total protein (electrophoretic method), Na, K, Ca, P, red cells blood count and PTH. MNCV, SNCV and VEPs appeared to slow down early, sometimes even where there were no clinical symptoms. In addition, there is a direct correlation with decreasing renal function. MNCV and SNCV were correlated directly, reciprocally although the compromise of SNCV appeared an earlier phenomenon. The significant direct correlation between MNCV, SNCV and serum PTH suggests that the latter has an important peripheral neurotoxic role. VEP recording permits detection of early abnormalities in the central nervous system with residual renal function values around 40%.

Adult↗

EMG changes in chronically dialyzed uraemic subjects undergoing d, 1-Carnitine treatment.

The deficiency of muscle Carnitine secondary to chronic dialysis frequently induces lipid storage in striated muscles associated with progressive myocardial involvement. Serial EMG recordings disclose the presence of several motor unit potential families in tibialis anterior muscle related to damage of peripheral nervous fibres and muscular districts due to the storage of lipid vacuoles. The administration of d,1-Carnitine to twenty chronically dialyzed uraemic patients significantly improved distal latency of the M response of the external peroneal nerve at the EDB muscle and the MUP properties suggesting a Carnitine-dependent amelioration of fatty acid oxidative processes both in muscle and Schwann cells. The main side effects following d,1-Carnitine oral administration (3 g/daily) is a myasthenia-like symptom complex that is promptly reversed on drug interruption.

Action Potentials↗