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Biomedical subjects

F Bruno

Publications and source records attributed to F Bruno.

At least 91 records · Page 5Linked to original sources
PubMed1977

A convenient preparation of beta-N-acetylhexosaminidase from commercial bovine serum albumin.

A simple procedure for the preparation of beta-N-acetylhexosaminidase (EC 3.2.1.52), free from other glycosidases, from commercial bovine serum albumin is described. It has been fractionated into three peaks on a DEAE-cellulose column. The Km and V values for 4-methylumbelliferyl-beta-D-N-acetylglucosaminide (4MU-gluNAc), 4-methvlumbelliferyl-beta-D-N-acetylgalactosaminide (4MU-galNAc), p-nitrophenyl-beta-D-N-acetylglucosaminide, and p-nitrophenyl-beta-D-N-acetylgalactosaminide for each was established. The inhibition by several structural analogues on 4MU-gluNAc and 4MU-galNAc hydrolysis by the enzyme present in peak 1 was investigated.

Acetylgalactosamine↗
PubMed1977

alpha-Fetoprotein production and erythropoiesis in cell cultures of human fetal liver.

alpha-Fetoprotein and the synthesis of heme associated with hemoglobin were measured simultaneously in short-term cultures of human fetal liver cells to correlate the relationship of alpha-fetoprotein to erythroid cell function. Both synthetic processes decreased exponentially during the first 5 days of culture. The use of media supplemented with different batches of fetal calf serum and porcine portal vein serum indicated that the optimal conditions for the production of alpha-fetoprotein were different from those required for the synthesis of heme associated with hemoglobin. Moreover, the alpha-fetoprotein-producing cells could be separated from erythroid cells after velocity sedimentation in Ficoll gradients. Although it is well known that erythropoiesis and alpha-fetoprotein production occur simultaneously during ontogenesis, alpha-fetoprotein itself (0.01-100 micron g/ml) did not stimulate heme synthesis in liver erythroid cells. Erythropoietin did not stimulate alpha-fetoprotein production. It is concluded that there is no cause-effect relationship between alpha-fetoprotein production and erythroid cell fuction in human fetal liver cells and that the two processes occur independently in different cell types.

Cells, Cultured↗
PubMed1977

Effects of testosterone and estradiol on ratios of adult to fetal hemoglobin in cell cultures of human fetal liver.

The effects of testosterone and 17beta-estradiol on the synthesis of fetal and adult hemoglobins have been studied using a short-term primary cell culture system of human fetal liver at midgestation. There was a significant 23% increase in incorporation of 59Fe into adult hemoglobin relative to the total after the addition of 5 X 10(-8)M testosterone. 17beta-Estradiol (10(-6)M) lowered the incorporation of 59Fe by 21%. beta-Globin chain synthesis, measured as 3H- or 14C-leucine incorporation into globin chains, was identical in control and testosterone-treated cells and only slightly lower when 17beta-estradiol was added. For this reason the observed changes in adult hemoglobin resulting from the action of testosterone and 17beta-estradiol are caused by an indirect effect either in the final hemoglobin assembly or by small changes in the gamma/alpha-chain ratio which may be undetected by the methodology used.

Cells, Cultured↗
PubMedDate not supplied

Atherosclerosis and thrombosis. Old and new drugs.

Thanks to the increasing knowledge of the pathogenesis of atherosclerosis, much effort has been made in the last years to develop new drugs aimed at controlling risk factors correlated with the disease as well as to investigate more deeply their mechanism of action. In particular, this brief review will describe some new aspects of the mechanism of action of drugs widely used in the control of risk factors like hyperlipemia, hypertension and blood viscosity. Among drugs active on plasma lipid profile, HMG-CoA reductase inhibitor are, at present, under study for their promising activity in the modulation of the interaction between the cells of the arterial wall and circulating blood elements. Indeed, these compounds have been found to control the proliferation of smooth muscle cells and other events related to the formation of atheroma. As far as antithrombotic drugs are concerned, the efficacy of low doses of aspirin has emerged by recent clinical trials. The successful use of low doses of aspirin has been possible following the comprehension of the mechanism by which this compound inhibits TXA-dependent platelet function, thus allowing a dose-dependent dissociation of the antithrombotic activity from other undesirable effects. Also for calcium antagonist an antiatherogenic effect which deserves further investigations has been recently clarified. Indeed it has been demonstrated that calcium antagonists have a protective effect against vascular lesions because they inhibit smooth muscle cell proliferation, lipid uptake by macrophages and the production of collagen and elastin. Another class of drugs which represents a new approach in the control of some risk factors is represented by n-3 fatty acids. Besides their activity on triglycerides, these compounds exert a positive effect on hemostatic and thromboembolic event, by reducing platelet aggregation and blood viscosity. Also for those molecules which appear to exert promising antiatherosclerotic and antithrombotic action, further studies will define their exact mechanism of action.

Journal Article↗
PubMedDate not supplied

[Exogenous surfactant treatment for severe acute viral bronchiolitis: case report]

OBJECTIVE: To describe the possible clinical and laboratory effects of exogenous surfactant instillation into the tracheal tube of a child with severe acute bronchiolitis undergoing mechanical ventilation. CASE REPORT: a 2-month-old girl with clinical diagnosis of acute viral bronchiolitis underwent mechanical ventilation. She required high positive inspiratory peak pressure (35 to 45 cmH(2)O) and high inspiratory fraction of oxygen (FiO(2) = 0.9), but showed no clinical response or improvement in the arterial blood gas analysis. An exogenous surfactant (Exosurf(R), Glaxo - 50 mg/kg) was used to facilitate the use of a less aggressive ventilatory strategy. RESULTS: Four hours after surfactant administration, it was possible to reduce the positive peak inspiratory pressure (PIP) from 35 to 30 cmH(2)O, and FiO(2) from 0.9 to 0.6; and to increase the positive end-expiratory pressure (PEEP) from 6 to 9 cmH(2)O. During this period the paO(2)/FiO(2) ratio increased from 120 to 266. At the end of 24 hours, FiO(2) could be reduced to 0.4. DISCUSSION: Surfactant inactivation may be a decisive factor in the unfavorable evolution of some severe cases of acute bronchiolitis. The tracheal instillation of exogenous surfactant, in these cases, allows us to adopt less aggressive ventilatory strategies, and promotes rapid clinical responses.

Journal Article↗
PubMedDate not supplied

[Short-term effects of prone positioning on the oxygenation of pediatric patients submitted to mechanical ventilation]

OBJECTIVE: To analyze the short-term effects of prone positioning on the oxygenation of mechanically-ventilated children suffering from severe hypoxemia. MATERIALS AND METHODS: A prospective, nonrandomized trial (each patient as his/her own control) was conducted between July 1998 and July 1999. Mechanically-ventilated children with peak inspiratory pressure greater than or equal to 30 cm H(2)O, FiO(2) greater than or equal to 0.5, and PaO(2)/FiO(2) ratio less than or equal to 200 were included in the study. Each patient was kept in the prone position for two hours, returning to the supine position after this period. Oxygenation was assessed by means of PaO(2)/FiO(2) in the supine position (one hour before prone positioning), one hour after prone positioning, and one hour after returning to the supine position. Patients who presented an increase of at least 20 in PaO(2)/FiO(2) were considered responsive. The results were compared by Student t-test, Friedman test, chi-square test, Fishers exact test, and confidence interval. RESULTS: Eighteen children (10 males), whose mean age was 11.5 -/+11.5 months, with initial PaO(2)/FiO(2) of 96.06 -/+ 41.78, participated in the study. After one hour in the prone position, 27.7% of the patients (5/18) improved their PaO(2)/FiO(2) ratio (P=0.045). Six of these patients presented reduced lung compliance (four of them had acute respiratory distress syndrome); and twelve patients showed increased airway resistance (six of them presented bronchiolitis). No significant difference was observed between these two groups (reduced lung compliance x increased airway resistance) in terms of age, sex, duration of ventilation prior to change in position, peak inspiratory pressure, FiO(2), severity of hypoxemia, and outcome. CONCLUSION: Prone positioning during mechanical ventilation of children with severe hypoxemia may improve the PaO(2)/FiO(2) ratio in the first hour.

Journal Article↗
PubMedDate not supplied

Liquid chromatographic/mass spectrometric determination of desmedipham and phenmedipham and their metabolites in soil.

A simple method is described for the simultaneous determination of residues of 2 carbamate herbicides (phenmedipham and desmedipham) and related metabolites (m-aminophenol, aniline, and m-toluidine) in soil. The analytes are extracted from spiked soils with methanol. The solvent/soil suspension is centrifuged, and the supernatant is directly injected, without any further cleanup, into a reversed-phase liquid chromatography/mass spectrometry apparatus equipped with a TurbolonSpray interface. The method was tested on 5 soils having different physicochemical properties. Recoveries from the soil types, spiked over the range of 50-200 ppb, were essentially quantitative for each analyte. The detection limits of the method are < or = 25 ng/g.

Carbamates↗
PubMedDate not supplied

[Total and partial O2 and CO2 ductances in workers exposed to inhalation of cement-asbestos].

The aim of the study was to assess the efficiency of the respiratory system in ensuring the correct dynamics of respiratory gases in subjects chronically exposed to the inhalation of asbestos-cement dust but not yet suffering from parenchymal asbestosis, via measurement of total and partial O2 and CO2 ductance coefficients (Du). Two groups of male workers of working age were selected, the first consisting of 22 workers employed on the manufacture of asbestos-cement products, the second consisting of 26 workers who had never been exposed to the inhalation of significant concentrations of occupational respiratory irritants. The two groups were comparable for age, smoking, and normal spirometric parameters for FVC, FEV1 and PEF, and were free of any type on interstitial lung disease according to ILO standards. In the exposed group, all O2 and CO2 ductance coefficients were significantly lower than in the non-exposed, except DuBCO2 (alveolar-capillary ductance for CO2). Measurement of O2 and CO2 lung ductances at rest thus revealed an impairment of the diffusion and of the interpulmonary exchange of blood and air in subjects chronically exposed to the inhalation of asbestos-cement dust. In the sample under study, such impairment preceded lung damage detectable by spirometric and radiological tests and was an obstacle not only to oxygen intake but also to the elimination of carbon dioxide.

Adult↗