PubMed Health⌕ Search

Biomedical subjects

E Lusvarghi

Publications and source records attributed to E Lusvarghi.

At least 37 records · Page 2Linked to original sources

Very late activation-3 integrin is the dominant beta 1-integrin on the glomerular capillary wall: an immunofluorescence study in nephrotic syndrome.

The expression of alpha 2; alpha 3; alpha 5; alpha 6-subunits of the beta 1 [very late activation (VLA)] integrin family was studied in kidney specimens using an immunofluorescent technique. 6 specimens from normal kidney were compared with 10 specimens from patients affected by various glomerulopathies [minimal change nephropathy (MCN), membranous nephropathy (MN) and systemic lupus erythematosus nephritis (SLEN)]. On normal glomeruli, alpha 3 was the dominant integrin, being mainly present on podocytes and showing a linear fluorescent pattern codistributed with laminin. In MCN and SLEN, alpha 3 presented a normal pattern. In MN, alpha 3 revealed a trabecular picture on thickened glomerular basement membranes. Moreover, in stage-III MN, a segmental loss of alpha 3-integrin was detected. In our opinion, VLA-3 may offer an interesting approach to the study of the relationships between podocytes and their substrate.

Adolescent↗

Improved biocompatibility by modified cellulosic membranes: the case of hemophan.

The rising problem of biocompatibility is encouraging the development of new dialysis membranes, but the high cost of synthetic ones precludes their wide use. The authors compared the biocompatibility of cuprophan (CU), cellulose acetate (CA), and hemophan (HE), evaluating both in vitro and in vivo polymorphonuclear leukocyte (PMN) oxidative metabolism activation by resting chemiluminescence and complement activation by C3a; in vivo PMN counts during dialysis were also performed. The lowest increase in in vitro PMN resting chemiluminescence using HE was + 71.3% with CA, +49.3% with CU, and + 21.4% with HE (p less than 0.001 versus CA and CU); furthermore, HE did not significantly stimulate PMN resting chemiluminescence during in vivo hemodialysis: + 56.6% with CA, + 38.8% with CU, and + 3.7% with HE (p less than 0.01 versus CU and p less than 0.001 versus CA). C3a concentration increased with all membranes both in vitro and in vivo, but HE (in both experimental conditions) showed the lowest increase at any time (p less than 0.001 versus CA and CU). After 15 min of dialysis, PMN count dropped to 20.3% of basal values with CU, to 49.8% with CA, and to 76.5% with HE (p less than 0.001 versus CU and CA). Among cellulosic membranes, HE is the most biocompatible and appears to be an important step in preventing blood-membrane interactions and related complications.

Biocompatible Materials↗

Polymorphonuclear oxygen free radical production and complement activation induced by dialysis membranes as assayed in an experimental model.

Activation of polymorphonuclear leukocytes with subsequent production of reactive oxygen metabolites has been reported to occur during hemodialysis related to a membrane bioincompatibility. We used an experimental dialysis model to evaluate, by chemiluminescence, the production of reactive oxygen metabolites and, by C3a, complement activation induced by cuprophan, cellulose acetate, hemophan, polysulfone, polyacrylonitrile, polymethylmethacrylate or polyvinyl chloride blood lines alone. No differences were obtained in the system, at time 30 min compared to initial values, as far as zymosan-activated chemiluminescence is concerned; resting chemiluminescence increased markedly with cellulose acetate (+71%), cuprophan (+49%), polymethylmethacrylate (+22%), hemophan (+21%) but had no variation with polysulfone, polyacrylonitrile and blood line. The time course of C3a levels up to 120 min showed a marked rise with cuprophan and cellulose acetate, a moderate increase with hemophan, polysulfone and blood line, and a decrease with polymethylmethacrylate and polyacrylonitrile. The results obtained documented a different behavior of the production of reactive oxygen metabolites compared to complement activation and support the hypothesis that the production of reactive oxygen metabolites by polymorphonuclear leukocytes is stimulated not only by complement activation but also by a direct dialysis membrane interaction.

Biocompatible Materials↗

Oxidative metabolism of polymorphonuclear leukocytes and serum opsonic activity in chronic renal failure.

Luminol-amplified chemiluminescence was used to study the oxidative metabolism of polymorphonuclear leukocytes (PMN), in resting state and in response to opsonized zymosan, in 65 patients with different degrees of chronic renal failure (CRF) or on regular dialysis treatment (RDT). Every patient was compared on the same day with a normal subject. Furthermore, the serum opsonic activity was evaluated, cross-matching zymosan opsonized by serum from CRF-RDT patients and normals with PMN from CRF-RDT patients and normals. PMN resting chemiluminescence showed a progressive increase inversely related to the glomerular filtration rate, and it remained high in patients on RDT. Zymosan-activated chemiluminescence indicated a deficit in phagocytosis for PMN of patients with a glomerular filtration rate lower than 10 ml/min, persisting in RDT patients. The serum opsonic activity was always significantly lower in CRF and in RDT patients than in the control group; this defect was already present in patients with mild renal impairment. Our findings suggest that PMN from CRF or RDT patients have an increased reactive oxygen metabolite production in the resting state that may cause cell and tissue damage; the opsonization impairment and the decreased PMN phagocytic activity contribute to increased vulnerability to infection in these patients.

Humans↗

Acid-base balance during biofiltration (BF).

Acid base balance during biofiltration (BF): Six patients on standard acetate hemodialysis (HD) were switched to BF with 1 m2 AN69-S membrane, 12 hours weekly (BF-4h) and, later on, to a stage with 1.2 m2 AN69-S, 9 hours weekly (BF-3h). During BF, in order not to exceed 25 mEq/l in intradialytic arterial HCO3, arterial acid-base was examined hourly and a mean of 178 and 199 mEq of HCO3 respectively were infused in BF-4h and BF-3h. We obtained a better control of acidosis with a reduction of the intradialytic pCO2 decrease and hypoxemia. The amount of HCO3 infused was related to the patients deficit in HCO3 total pool and therefore it can be predicted, to avoid postdialytic alkalosis.

Acetates↗

[Increased muscular irritability syndrome: treatment with nifedipine. Report of a case].

In 1980 Alberca et al. described a patient with a syndrome of increased muscle irritability, who presented ondulating muscle rolling movements and electrically silent cramps, myoedema and muscle reactions to mechanical stimulation similar to myotonic response, suggesting a disfunction at myofibrillar level. We saw a similar case, of a male patient, 21 years of age, who complained of cramps of severe intensity for the past four years. These cramps were painful in the upper and lower limbs and impaired his locomotion; they were electrically silent. At percussion the patient showed severe idiomuscular contraction, with a period of increased relaxation, similar to a myotonic reaction and also, prolonged myoedema and rolling muscle contractions. Electromyography was normal, as were histochemical and electron microscopy studies. We carried out a therapeutic trial with niphedipine (a calcium antagonist), on the assumption that the patient showed a disturbance of the myofibrillar function--even though physiopathogenesis of the hyperirritability muscle syndrome was not yet clearly defined--and with a basis on the importance of the intracytoplasmatic level of Ca++ free in the muscle contraction mechanism, not only as the initiating factor of the contractile process, but also as a quantitative controller of the mechanic tension development through regulation of the amount of ATP metabolized during muscle activity. Administration of the drug in a dose of 40 mg daily, per os, brought a remission of the symptoms after two weeks, and the patient could walk normally again. On the introduction of a placebo, on two different opportunities, there occurred a recrudescence of the symptoms after about one week's time.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Transcutaneous renal needle-biopsy guided with ultrasonics].

Authors performed percutaneous renal biopsy guided by ultrasounds in 10 patients in whom urography was dangerous or did not provided good renal images. The advantages of this method are in the directional and dimensional accuracy of ultrasound scanning, so that the exact topography of the kidney can be established. The use of ultrasonically guided renal biopsy is mainly recommended in iodine medium idiosyncrasy, in myelomas and renal failure. This method can be preferred in order to establish the exact topography of kidney, in acute anuric renal failure, in chronic failure (when high doses of iodate contrast are needed), and in the presence of cyst.

Adult↗

Long-term use of a "stable" bicarbonate containing dialysate.

We present an original method for the preparation of "stable" dialysate containing 35 mEq/l of bicarbonate. The dialysate was utilized with 4 patients for periods ranging from 4 months to 1 year according to a short-term recirculated dialysis schedule in closed circuit (20-40L) (2-2 1/2 hrs) on alternate days. Preliminary results are reported here with respect to the tollerance of the dialytic run and correction of the acid-base balance equilibrium. The clinical tollerance is excellent despite high dehydration rates even in patients particularly sensitive to ultrafiltration. The acidosis correction would seem to be much better with bicarbonate than with traditional dialysis. The difference is even higher if we consider the brevity of the dialysis. During the bicarbonate dialysis we do not observe any fall of the PCO2 or significant difference in PO2 in the patient's blood. The correction of acidosis probably causes the normalization of pre-dialytic potassiemia in spite the "net" removal of K with short dialysis is considerably less.

Acidosis↗