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Biomedical subjects

A Vercellone

Publications and source records attributed to A Vercellone.

At least 55 records · Page 3Linked to original sources
PubMed1989

The production of platelet-activating factor during hemodialysis.

Regenerated cellulosic membranes (CU) induced the aggregation of plasma-free human neutrophils when recirculated in a dynamic model of dialysis without the patient on the circuit. Neutrophil aggregation was linked to the production of PAF by these cells. In the absence of detectable PAF production, no neutrophil aggregation occurred, as observed during recirculation with polymethylmethacrylate (PMMA) membranes. With polycarbonate (PC), PAF production and aggregation of neutrophils were both almost half the values with CU. PAF production was studied in ten hemodialysis (HD) patients tested twice with CU and once with PC and PMMA membranes. PAF was extracted in the venous blood during filling of the dialyser for 9/20 of patients with CU (3.1 +/- 2.9 ng/ml, mean +/- 1 S.D.) a membrane that induced marked leukopenia (greater than 50% of basal values at 15 min), C3a des Arg generation (greater than 500% at 5 min), and plasma levels of the elastase-alpha 1-proteinase inhibitor complex (greater than 500% at the end of HD). Membranes such as PC and PMMA showing intermediate or low potential to induce leukopenia and C3a des Arg generation, respectively, did not trigger the production and release of PAF in detectable amounts at any interval. However, with PMMA, plasma neutrophil elastase was significantly higher than baseline at the end of dialysis. These levels were not significantly different (p less than 0.05) from those observed with CU and PC membranes.

Cell Aggregation↗
PubMed1989

Pregnancy-related acute renal failure.

From 1958 to 1987, 81 cases of pregnancy-related acute renal failure (PR-ARF) were observed (9% of the total number of acute renal failure [ARF] needing dialysis). In the three successive ten-year periods (1958-67, 1968-77, 1978-87) the incidence of PR-ARF fell from 43% to 2.8% with respect to the total number of ARF, and from 1/3,000 to 1/15,000 with respect to the total number of pregnancies. Maternal mortality was high (32%), with 5 cases of death in the last ten years. Irreversible renal damage was recorded in 11.6% of PR-ARF, and, in particular, in 26.3% of cases in preeclampsia-eclampsia (PE-E). Worse maternal and renal prognosis occurred in PE-E complicated by abruptio placentae. Neither disseminated intravascular coagulation (DIC), microangiopathic hemolytic anemia nor prostacyclin imbalance were significantly related to the severity of renal damage. Heparin therapy did not modify DIC evolution and renal outcome and was aggravated by severe hemorrhagic complications. In conclusion, PR-ARF has become a rare, but still critical occurrence, and the most effective measures would be a program of careful prevention.

Acute Kidney Injury↗
PubMed1988

Particular matrix for fast atom bombardment mass spectrometric analysis of phenolic glycolipid antigens isolated from pathogen mycobacteria.

Phenolic glycolipids play a key role as an antigenic probe for serodiagnosis of some human pathogen mycobacterial infections. The lipidic part which corresponds to a phenolphthiocerol dimycocerosate molecule, and the presence of partial O-methylated sugars, confer a high hydrophobicity to this kind of molecule. Fast atom bombardment (FAB) mass spectrometric analysis with standard matrices such as glycerol or thioglycerol was unsuccessful. Using a new matrix--monobutyltriethylene glycol--FAB analysis allows molecular weight determination and partial structural elucidation of the saccharidic and the lipidic part of those compounds.

Antigens, Bacterial↗
PubMed1988

Ultrafiltration in the treatment of refractory congestive heart failure.

Artificial subtraction of fluids and solutes was evaluated in the course of acute and chronic heart failure when it became refractory to standard intensive medical treatment. A group of 19 patients (mean age 57 years), 9 with ischemic, 2 amyloidotic, 4 valvular, and 4 idiopathic cardiomyopathy, were treated. In 17 patients extracorporeal ultrafiltration (UF) by means of a polysulfonate ultrafilter was adopted along 125 sessions (105 assisted by a roller pump and 20 as a slow continuous ultrafiltrate). In two patients continuous peritoneal dialysis was adopted. In every case UF was well tolerated. Ultrafiltrate volumes ranged from 1680 to 3500 ml for every session with corresponding Na losses ranging from 194 to 434 mEq/session. Improved clinical and functional status with reduction of edema was observed in 17 of 19 patients. In 12 patients UF could be discontinued due to restored response to diuretics; 5 of these patients could subsequently undergo heart surgery (1 transplant, 3 valve replacement, 1 coronary bypass). The remaining 7 patients survived on medical therapy alone for an average of 228 days. In 7 of 19 cases, UF could not be discontinued, and these patients died after an average of 23 days of treatment. In conclusion, UF proved to be effective in eliminating salt-fluid overload and restoring response to medical treatment. Patients who are potential surgical candidates seem to be the most suitable for UF.

Adult↗
PubMed1988

The role of intravascular coagulation in pregnancy related acute renal failure.

Pregnancy-related acute renal failure (ARF) can include reversible tubular necrosis as well as irreversible cortical necrosis. Though pathogenetic mechanism are not fully understood, disseminated intravascular coagulation (DIC) probably plays a primary role. We report 25 cases of pregnancy-related ARF: 13 were associated with preeclampsia or eclampsia and 12 with obstetric complications. The following parameters were studied: partial thromboplastin, prothrombin and thrombin time, fibrinogen, anti-thrombin III and FDP levels, platelet count, whole blood clot lysis time and area, fragmented red cells (schistocytes) in the blood smear, hemoglobin, aptoglobin and LDH concentrations. DIC was scored in arbitrary units ranging from 12 to 36 and related to the clinical picture, renal outcome and the treatment employed. Five patients had irreversible renal damage, while 19 recovered fully; one patient died and no renal histology was available. The DIC score did not seem to have a significant relation to the severity of renal damage.

Acute Kidney Injury↗
PubMed1988

The case for oxygen free radicals in the pathogenesis of ischemic acute renal failure.

One of the more glaring paradoxes of ischemic acute renal failure is that such injury appears to be worse in the kidney as opposed to other organs, even though the kidney is the best oxygenated. An answer can be deduced from the anatomical and physiological background, together with a reappraisal of the role of medullary vascular damage and recent evidence of the importance of the postischemic component of ischemic injury, which is mediated by oxygen free radicals. As far as oxygenation is concerned, the kidney's Achilles heel is the tubules of the outer strip of the outer medulla, which are also those that have the most metabolic activity. It is here that ischemic injury begins, and is maintained and exacerbated in the postischemic stage by the free radicals. These are produced by the kidney in large quantities, since it has all the necessary chemical ingredients available. It is therefore readily understandable why the kidney, being the best oxygenated organ, is so sensitive to an ischemic insult, since the damage caused in the postischemic stage is increased the greater the amount of oxygen brought in by reperfusion.

Acute Kidney Injury↗
PubMed1988

Long-term results of CAPD in Italy: a report from the Italian CAPD Study Group.

Begun in 1979, the Italian CAPD Study Group monitored prospectively six years of CAPD experience (1980-1985) in 24 centers with 1107 end-stage renal disease (ESRD) patients (age 56.4 +/- 13.7 years). Compiled yearly, the clinical and therapeutical data were processed on a PDP 11-32 computer, according to UCLA BMPD-1L procedure. The survival rate was conditioned by age (more than 70) and by major clinical risk factors, with a large fraction of the deaths due to cardiovascular causes (40.6%) and cachexia (17.8%). The progressive reduction of peritonitis incidence (1/18.5 episodes/patient-month globally reached at the end of 1985) was due mainly to the wide spread adoption of the "Y" connection set (76% for 1985) and contributed to a decrease in drop-outs to 7.5% of 676 patients on CAPD during 1985.

Female↗
PubMed1987

Oxygen free radicals in nephrology.

For living creatures with an aerobic metabolism, the univalent reduction of oxygen can lead to formation within the cell of intermediate products with marked chemical instability and strong potential toxicity. These are the free radicals (FR) superoxide and hydroxyl, hydrogen peroxide and the singlet 1O2. Their toxicity is primarily expressed through the peroxidation of membrane lipids, resulting in mitochondrial, lysosomal and parietal damage. It is enhanced by the presence of metals in trace amounts. Imbalance between the production of FR and the availability of FR scavengers (superoxide dismutase, catalase, glutathione peroxidase, etc.) may underlie different human pathologies. FR have been thought to play a part in inflammation, the aging process, carcinomatous transformations, damage due to recirculation and autoimmune diseases. As far as the kidney is concerned, the intervention of FR has been demonstrated or can be postulated in various contexts in the light of what has been observed in other pathologies: immunological nephritis, toxic nephropathies, microthrombotic and microangiopathic processes, damage caused by post-ischemic reflow, and problems in the preservation and rejection of transplants. FR have also been incriminated in lung lesions following intradialytic leukostasis and some aspects of toxicity ascribable to uremia. Subject to the precautions imposed by the need for theoretical, experimental and clinical verification, FR biochemistry offers new keys to the interpretation of a variety of kidney pathologies and opens up new prospects for treatment, both through a better understanding of the mechanism of action of drugs already known and employed, and with regard to the practical possibility of using alternative or combined forms of therapy.

Animals↗
PubMed1987

In vitro complement-independent activation of human neutrophils by hemodialysis membranes: role of the net electric charge.

Polymethylmethacrylate (PMMA) membranes with different net electric charges and percentage water contents (anionic 71%, neutral 70%, cationic 75%) were evaluated for their ability to stimulate plasma-free human polymorphonuclear neutrophils (PMN), and compared for potency to cuprophan (Cu), already described as being a potent trigger of PMN. The release of lysozyme, beta-glucuronidase, lactic dehydrogenase (LDH), and the generation of a platelet aggregating activity were studied in the supernatants from plasma-free human PMN incubated with different membranes. The PMN intracellular content of neutrophil cationic proteins (NCP), elastase, and cathepsin G were also studied by immunofluorescence using specific antisera on smears of PMN before and after incubation with each membrane. Only cationic, but not anionic or neutral PMMA induced a marked release of lysozyme (range 20-25% of the sonicated control, assumed as 100%), and beta-glucuronidase (40-43%), and marked depletion of the intracellular content of NCP, elastase, and cathepsin G, suggesting a degranulation process. Platelet aggregating activity was generated and referred to the release of platelet activating factor (PAF) only in the supernatants from PMN incubated with cationic, but not with anionic, or neutral PMMA membranes. These results indicate that modification of the net electric charge can per se turn PMMA, commonly recognized as inert, into a material with marked PMN activating effects, comparable to those of Cu, a highly reactive polymer.

Cations↗
PubMed1986

Postpartum acute renal failure in a drug addict.

Renal diseases occur in intravenous drug abusers, especially heroin addicts, in the form of interstitial nephritis, nephrotic syndrome or acute renal failure due to rhabdomyolysis. We report a case of acute renal failure not ascribable to rhabdomyolysis nor to the main pathogenetic mechanisms of pregnancy-related acute renal failure in a pregnant heroin addict woman after vaginal delivery following uncomplicated pregnancy. Drug-related immunological abnormalities and microcirculatory distress may be involved.

Acute Kidney Injury↗