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Biomedical subjects

F Rossi

Publications and source records attributed to F Rossi.

At least 667 records · Page 37Linked to original sources
PubMed1984

[Remission induced at the early stage of insulin-dependent diabetes: do predictive factors exist?].

The induction of a remission has been attempted in 28 patients with insulin-dependent diabetes of less than 3 months' duration by strictly normalizing glycemia either with a period of external artificial pancreas followed by continuous subcutaneous insulin infusion (22 patients) or with continuous subcutaneous insulin infusion alone (6 patients). HLA A, B and DR antigens were determined in every patient. Residual beta-cell function was evaluated by measuring C peptide and the ratio of C peptide to glycemia, and by testing the response to a glucagon stimulation before initiating and after withdrawing insulin treatment. Oral treatment with 15 mg glibenclamide and 840 mg metformin daily was administered when insulin had been stopped. A remission was obtained in 17 of the 28 cases. The likelihood of a remission was greater if: (1) the patient was older (mean age was 25.6 years in case of success and 16.6 Years in case of failure); (2) initial daily needs for insulin were smaller (0.88 v. 1.23 U/kg); and (3) stimulated secretion of C peptide was larger (0.22 v. 0.11 mmol/l).

Adolescent↗
PubMed1984

Rheumatological manifestations of infective endocarditis.

A retrospective study showed musculoskeletal manifestations in 32 of 108 patients treated for infective endocarditis in several departments at the Poitiers CHU. Such manifestations included articular pain or aseptic arthritis, typically involving the major joints, as well as vertebral osteomyelitis, low back pain (inflammatory or non-inflammatory), and myalgia. Patients showing such signs were generally younger than those without musculoskeletal involvement, diagnosis was made later, and prognosis was worse; streptococcus D was more often involved, and microscopic haematuria was more common. With the exception of vertebral osteomyelitis, the pathogenesis was not clear.

Antigen-Antibody Complex↗
PubMed1984

Systemic and ocular effects of alpha 2-adrenergic stimulating and beta 2-blocking agents.

The effects of alpha 2-adrenergic stimulating agents (clonidine and guanabenz) and beta-adrenolytic agents (atenolol and propranolol) on the systemic arterial pressure, heart-rate, blood glucose level and intraocular pressure, as well as on the concentrations of glucose, Na+, K+ and Ca++ in the lens and aqueous and vitreous humours, are evaluated in the rabbit. alpha 2-adrenergic stimulating agents cause a significant increase of the glucose concentration in the blood, lens, aqueous and vitreous humours; whereas the beta-adrenolytic agents cause insignificant effects. Neither of the two drugs alters the concentration of Na+, K+ and Ca++ in the lens and aqueous and vitreous humours.

Adrenergic alpha-Agonists↗
PubMed1984

[Determination of the optimal dose of captopril in the treatment of severe cardiac failure by hourly hemodynamic monitoring].

The optimal dose of Captopril was evaluated by hourly haemodynamic monitoring in 10 patients with chronic congestive cardiac failure (Stage IV of the NYHA Classification) after administration of 25 mg, 50 mg, and 100 mg of Captopril. A similar improvement was observed in all the parameters considered with all three dosages. At its peak effect (90 minutes) 25 mg of Captopril caused a fall in pulmonary capillary, and mean pulmonary artery pressures, and a fall in systemic resistance of 40%, 20% and 30% respectively; with 50 mg of Captopril, the effect was a fall of 36%, 24% and 35% respectively. The cardiac index rose by 17% with 25 mg of Captopril, 28% with 50 mg and 12% with 100 mg of Captopril. Although the fall in pulmonary capillary pressure remained significant up to the 6th hour, the improvement in cardiac index was not significant after the 3rd hour. After 8 days' treatment, plasma renin activity increased from 7.01 +/- 4.68 to 23.6 +/- 18.3 ng/ml/hour (p less than 0.02) and serum aldosterone fell from 1.175 +/- 386 p. moles/l to 497 +/- 277 p. moles/l (p less than 0.001). There was no correlation between basal plasma renin activity and pre- or post-therapeutic systemic resistances. The clinical and haemodynamic improvement was sustained after 2 months' treatment in 5 of these patients without side effects. Increasing the dosage of Captopril does not reinforce or prolong its action; moderate doses (25 mg) are as effective as high doses (100 mg). Captopril, which acts by inhibiting the renin- angiotensin-aldosterone system is the current treatment of choice in severe refractory cardiac failure.

Aged↗
PubMed1984

Cardiovascular effects of putrescine in dogs after systemic, intra-arterial vertebral and intraventricular injection.

Putrescine produced in anesthetized dogs significant cardiovascular changes at higher doses than other transmitters. The hypotensive response observed after intravenous injection is due to histamine release. Tachycardic effects seem to be due both to release of histamine and to a reflex stimulation of carotid-sinus baroreceptors. The hypotensive and bradycardic effects observed after microinjection of putrescine into the III cerebral ventricle or into the vertebral artery are due to an increase in parasympathetic output.

Animals↗
PubMed1984

Anorectal manometry in the diagnosis of Hirschsprung's disease--comparison with clinical and radiological criteria.

In 34 consecutive patients in whom the diagnosis of Hirschsprung's disease (HD) was suspected, the reliability of clinical symptoms, radiological parameters, and anorectal manometry was retrospectively and blindly evaluated by three independent investigators. In 19 patients the diagnosis of HD was histologically proved, while in the remaining 15 cases the diagnosis of idiopathic constipation was justified by persistent success of medical treatment at regular follow-up. Anorectal manometry was correctly diagnostic in all the patients who were examined. The recto and inhibitory reflex, recorded in all the patients with idiopathic constipation was absent in patients suffering from HD. Moreover, other manometric parameters, peculiar to HD were found: a significant lower anal resting pressure and pain threshold, as well as a decreased frequency of spontaneous rhythmic oscillations. The reliability of radiological and clinical data for these diagnoses appeared to be inadequate. Therefore, the diagnosis of HD can be confidently stated only on the basis of manometric investigations.

Adolescent↗
PubMed1983

[Functional electric stimulation. Our experience].

The use of F.E.S. in motor rehabilitation should be reserved for cases of central neurological lesions. F.E.S. tends to improve gait, reduce spasticity and improve the transfer of cortical information from the peripheral system. The treatment exploits the possibilities of reprogramming movement by developing new motor circuits and where possible restoring lost movements.

Electric Stimulation Therapy↗
PubMed1983

Relationship between the binding of N-formylmethionylleucylphenylalanine and the respiratory response in human neutrophils.

The results presented in this paper demonstrate that the chemotactic peptide N-formylmethionylleucylphenylalanine (f-Met-Leu-Phe) is rapidly inactivated by the products of the respiration of human neutrophils stimulated by the peptide itself. The process of inactivation is impeded by the addition of inhibitors of myeloperoxidase (KCN, NaN3), of catalase, of methionine but not by the addition of superoxide dismutase, indicating that the mechanism of inactivation is the oxidation of methionine residue by myeloperoxidase-H2O2-halide system. The oxidation of the peptide causes the rapid cessation of the respiratory burst, since the sulfoxide derivative loses its ability to bind the specific receptors of neutrophil surface and, hence, its biological activity. The comparison between the time course of the binding of f-Met-Leu-[3H]Phe to the specific receptors and the rate of the respiratory response of neutrophils in the presence and in the absence of the process of peptide oxidation was used to investigate the mechanism of the activation of the respiratory burst by the peptide-receptor complexes. In conditions where the inactivation of the stimulatory agent takes place the stimulated respiration slows down and resumes the resting state shortly after the cessation of the binding, although a substantial amount of the peptide remains bound to the specific receptors. In conditions where the degradation of the peptide does not occur the binding of the peptide and the respiratory burst continue for a longer period of time, but the rate of the respiration, calculated in terms of the instantaneous velocity (Vist), is not correlated to the amount of the ligand bound to the membrane receptors measured at various times, indicating that a summation of the effects of the ligand-receptor complexes does not occur as they form. These findings demonstrate, as far as the respiratory response is concerned, that the biological activity of the peptide-receptor complexes is short-lived and that continuous de-novo receptor occupancy is necessary for the maintenance of the activated respiration.

Chemotactic Factors↗
PubMed1983

The cytochrome b and flavin content and properties of the O2- -forming NADPH oxidase solubilized from activated neutrophils.

NADPH-dependent O2- -generating activity was extracted and partially purified from guinea pig polymorphonuclear leukocytes. The most active preparation generated 202.8 nmol O2- min/min per mg protein. This activity was 30-fold higher than that of extracts from resting cells, indicating that the activated state of the oxidase was retained after solubilization. The solubilization and purification of the enzyme activity were followed by a parallel solubilization and purification of cytochrome b. Spectroscopic studies showed that solubilized cytochrome b has an Em of -245 mV and binds CO to about 30%. Cytochrome b was reduced by NADPH in anaerobiosis at a low rate and was rapidly reoxidized by air. A correlation was found between the inhibition of O2- formation caused by the SH reagent p-chloromercuribenzoate and the alterations induced by this compound on the Em of cytochrome b. These observations strongly support the participation of cytochrome b in the catalytic activity of the solubilized NADPH oxidase. The enzyme preparations contained FAD, which was found to be associated both with NADPH oxidase and with diaphorase activities. The fraction with the highest O2- forming activity contained FAD and cytochrome b in a ratio of about 0.5:1. The participation of FAD in the electron transport from NADPH to O2 is supported also by the inhibitory effect exerted by quinacrine on O2- formation.

Animals↗
PubMed1983

[Effects of parenteral nutrition on gastric secretion in patients in cerebral coma].

Total parenteral feeding reduced gastric secretions, but patients sometimes complain of pyrosis and acidity. The gastric secretion, gastrinaemia and insulinaemia of 96 patients subjected to TPN were measured. Results showed a nonpathological increase in gastrinaemia and acidity which might be related to the high levels of insulinaemia.

Coma↗
PubMed1983

[Enzymatic reaction of the follicular cell population in the human appendix].

Histochemical techniques were employed to determine acid phosphatase and alpha-naphthylesterase activities in follicular cells from the mucosa of surgically removed human appendixes. These very reactive cells are found in two areas: in the middle of the light centre and in the surroundings of this centre. The former are globose, arranged with a certain degree of order, and have a reticular anchorage that does not appear to be particularly affected by the physiological and pathological events that occur in the appendix, whereas those of the border vary in number or may even be absent. They have an elongated shape and are also anchored in a reticulum that in this case is more consistent. The result is that in certain forms of appendiceal disease the pale centre of the follicle is closed in a kind of shell formed of very reactive cells. The identification and significance of these two groups of cells of the light centre are discussed.

Acid Phosphatase↗
PubMed1983

The position of the motor endplate during growth.

The preliminary results of a study of the position of motor endplates with respect to the length of the soleus and long palmar muscles in the 17-day-foetus and throughout postnatal growth in Wistar albino rats are presented. The position adopted by the plate at the time of its formation is retained throughout growth in both muscles, namely at the centre of the fibres in the soleus, and nearer the proximal head in the long palmar. A difference in AChE activity in the distal and proximal head of the long palmar was observed by autoradiography with 3H-DFP.

Animals↗
PubMed1983

Metabolic properties of freshly isolated bovine endothelial cells.

Studies on endothelial cells metabolism have been limited by the lack of availability of a procedure for obtaining such cells in quantities adequate for direct in vitro analysis. Viable and well-dispersed endothelial cells in high yield have been obtained from the cavernous bodies of bovine penis. A preliminary characterization of the metabolic properties of the isolated cells has concerned the respiratory activity and some aspects of the carbohydrate metabolism. This study points out the following metabolic characteristics of endothelial cells: (1) a low respiration that is inhibited by high glucose concentrations (Crabtree effect); (2) a very high glycolytic activity in aerobic conditions, with a low Pasteur effect; (3) a very high potential activity of the hexose monophosphate shunt relative to the actual flux in the pathway. The biological relevance of these observations is discussed.

Animals↗
PubMed1983

Studies on stimulus-response coupling in human neutrophils. II. Relationships between the effects of changes of external ionic composition on the properties of N-formylmethionylleucylphenylalanine receptors and on the respiratory and secretory responses.

Studies were carried out on the mechanism responsible for the enhancement of the respiratory and secretory responses to N-formylmethionylleucylphenylalanine (fMet-Leu-Phe) exhibited by human neutrophils suspended in Na+-free, high-K+ buffered solution. The results demonstrate that: (a) the variation of Na+ concentration in the suspending solution induces in human neutrophils a marked modification of the recognition apparatus for the chemotactic peptide fMet-Leu-Phe, the lack of or low concentration of this ion increasing the number of the receptors and their specific affinity for the ligand; (b) the greater respiratory burst and secretion induced by fMet-Leu-Phe in human neutrophils suspended in Na+-free, high-K+ medium are due to the increased formation of receptor-ligand complexes at the cell membrane; (c) the greater respiratory response is partially due also to a higher efficiency of these receptor-ligand complexes. The molecular mechanism by which Na+ exerts a regulative role on the properties of the recognition apparatus for the chemotactic peptide and its possible significance are discussed.

Cations, Monovalent↗
PubMed1983

Isolation of metabolically active endothelial cells in high yield from bovine cavernous bodies. A model for functional studies on freshly isolated microvascular endothelial cells.

Work on endothelial cells has been limited by the availability of procedures for obtaining such cells in quantities adequate for direct in vitro analysis. The present paper describes a method for the isolation of endothelial cells from bovine cavernous bodies. A number of cells ranging from 2.5 to 4 X 10(8) per animal has been obtained. The cells were identified as follows 1) presence of the "Weibel and Palade" bodies in the isolated cells, 2) "cobblestone" appearance of cell cultures, and 3) presence of factor VIII, as demonstrated by immunofluorescence assays. The cell viability at the end of the purification procedure was tested 1) by dye-exclusion tests and 2) by metabolic assays. Features of this preparation are 1) the very high yield of viable endothelial cells, 2) the absence of contamination by fibroblasts and smooth muscle cells and a very low contamination by erythrocytes and 3) the fine dispersion of the isolated cells. These properties allow functional and subcellular fractionation studies on freshly isolated endothelial cells of microvascular origin.

Animals↗