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Biomedical subjects

G Zanetti

Publications and source records attributed to G Zanetti.

At least 199 records · Page 11Linked to original sources
PubMed1977

Molecular heterogeneity of ferredoxin-NADP+ reductase from spinach leaves.

Ferredoxin-NADP+ reductase (NADPH: ferredoxin oxidoreductase, EC 1.6.7.1) from spinach leaves has been purified according to a new procedure. The enzyme shows the presence of five molecular forms as identified by isoelectric focusing, namely a, b, c, d and e with pI values of 6.0, 5.5, 5.2, 5.0 and 4.8, respectively. All the bands are catalytically active and are clearly identifiable after the first steps of the purification procedure. The basic pattern of the ferredoxin-NADP+ reductase forms is the same whether extracted from one or many spinach plants and is not affected by the different purification procedures used. Two distinct classes of molecular weight have been found for the isolated forms b, c and d as measured by sodium dodecyl sulphate electrophoresis, with values of 33 000-34 000 for the first and 36 000-38 000 for the later two forms. Gel electrophoresis in non-denaturing media at different gel concentrations gives the same order of molecular weight values, thus ruling out the possibility that the native enzyme is a dimer, as has been reported by Schneeman, R. and Krogmann, D.W. ((1975) J. Biol. Chem. 250, 4965-4971). No significant kinetic differences were detectable for the isolated forms of ferredoxin-NADP+ reductase.

Amino Acids↗
PubMed1977

[Evaluation split renal function and compensatory hypertrophy using a radio-isotopic technique].

Using a new method for the determination of split renal function with a radio-isotopic technique (FG Hipaque I131 and PRP Hippuran I131) we sought to determine residual renal function with pre-operative studies, especially in preparation for nephrectomy, and secondly with postoperative studies of compensatory renal hypertrophy after total or partial nephrectomy and the restoration of function in the kidneys following surgery of the urinary tract. A total of 20 cases was studied. We noted marked compensatory hypertrophy after total and partial nephrectomy and the prompt return of function after procedures involving the urinary tract, on condition that any acute infection be prevented.

Adult↗
PubMed1976

A lysyl residue at the NADP binding site of ferredoxin-NADP reductase.

Dansyl chloride, at low molar ratio, inactivates ferredoxin-NADP reductase (NADPH:ferredoxin oxidoreductase, EC 1.6.7.1). The complete protection afforded either by NADP or NADPH suggests a direct involvement of the active site. Experiments with [Me-14C] dansyl chloride showed that about 1.5 residues per flavin were dansylated: by differential labelling experiments using NADP, it has been proved that enzyme inactivation is due to dansylation of one residue. The group modified has been identified as the epsilon-amino group of a lysine. The pH-inactivation profile indicates that this essential group has an apparent pKa of 8.7. The dansylated flavoprotein seems to maintain its native conformation; it shows a fluorescent chromophore with a peak at 335 nm. The modified enzyme has lost the capacity to form a complex with NADP, nevertheless it interacts normally with ferredoxin. It is concluded that the loss of catalytic activity which parallels the dansylation of a lysyl residue occurs because this residue is essential for the binding of the pyridine nucleotide substrate. Protection experiments with a series of coenzyme analogs further indicate that this lysyl residue interacts, most likely, with the 2'-phosphate moiety of NADP(H).

Adenosine Monophosphate↗
PubMedDate not supplied

Serum lipids and apoprotein composition (%) of the very low density lipoprotein (VLDL) fraction in two groups of diabetic patients: effects of oral as compared to insulin therapy.

Forty-one diabetic patients (21 males and 20 females) were divided into two groups according to treatment. One group (n = 22) was treated with insulin and the other with oral therapy (tolbutamide) (n = 19). The two groups of patients were in a good metabolic control in that the glucose loss in the urine was less than 10 g/24 h. In these two groups we have evaluated total serum cholesterol (TC), triglycerides (TG), VLDL TC/TG ratio and prevalence of 'double pre-beta lipoproteinemia'. For these parameters no significant differences have been found between the two groups. The results of our study suggest that, provided metabolic control is good, the VLDL metabolism does not seem to be affected by the type of treatment.

Adult↗
PubMedDate not supplied

Cardiac dysrhythmias induced by extracorporeal shockwave lithotripsy.

PATIENTS AND METHODS: We evaluated in 269 consecutive patients the incidence and gravity of dysrhythmic complications during nonsynchronized extracorporeal shockwave lithotripsy (SWL) using an electromagnetic lithotripter. RESULTS: Dysrhythmia occurred during treatment in 22 patients (8.8%) with no previous cardiac dysrhythmia. Ventricular extrasystoles occurred in 14 patients, atrial extrasystoles in 7 patients, and sinus bradycardia in 1 patient. It was not necessary to terminate treatment because of the occurrence of dysrhythmia in any of the patients. For 13 of the 22 patients (59%), it was sufficient to interrupt the treatment momentarily to obtain resumption of the normal rhythm. For 8 patients (36%), treatment was continued after triggering the release of the shockwaves with the refractory phase of the heart cycle. For one case of bradycardia (42 beats/min), it was possible to continue with the treatment after intravenous administration of atropine 0.5 mg. Pretreatment dysrhythmias were revealed by the electrocardiographic examination in 16 of the patients studied (6.3%). CONCLUSIONS: Extracorporeal shockwave lithotripsy without ECG triggering has been found to be fast and efficient and not correlated with the occurrence of dysrhythmic episodes of any particular clinical significance. No significant correlation was found between the occurrence of dysrhythmia, the side treated, the number and strength of the shockwaves, or the administration of analgesics. It was found, however, that dysrhythmia occurred almost exclusively in treatments involving the kidneys. The ECG-triggering option was indispensable in some patients in order to complete the lithotripsy without complications.

Adolescent↗
PubMedDate not supplied

Use of immunoglobulins in prevention and treatment of infection in critically ill patients: review and critique.

The study of the use of standard intravenous immunoglobulin (IVIG) preparations as adjunctive therapy for seriously ill patients is motivated by the need to restore immunoglobulin G depleted because of trauma or surgery and/or by the need to provide patients with specific antibodies to various microorganisms. Whereas no clinical studies have shown that standard IVIG has therapeutic efficacy, some data suggest that its prophylactic use is beneficial. Antisera or IVIG prepared from individuals who are hyperimmunized with the biologically active, highly conserved core portion of the endotoxin of gram-negative bacteria confer variable degrees of protection in animal models and clinical trials. Two clinical trials with use of monoclonal antibodies to core lipopolysaccharide have been completed. Only subsets of patients with gram-negative sepsis were protected by the monoclonal antibodies, but the results of the studies were discrepant in regard to the specific characteristics of patients who benefited from the administration of these antibodies. Further studies will be necessary to establish whether this therapy can be recommended for critically ill patients.

Antibodies, Monoclonal↗