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Biomedical subjects

M Bianchi

Publications and source records attributed to M Bianchi.

At least 325 records · Page 18Linked to original sources
PubMed1982

Evaluation of radiation-induced chromosomal aberrations in human peripheral blood lymphocytes in vitro: result of an IAEA-coordinated programme.

The results of an IAEA coordinated programme on radiation induced chromosomal aberrations in human peripheral blood lymphocytes in vitro are presented. In a master experiment, a whole blood sample from one donor was irradiated with 200 R of X-rays. Different fixation times from 46 to 82 h were used. The progression of cells into mitosis was monitored by BrdUrd incorporation. 14 investigators took part in the scoring of chromosomal aberrations. The main conclusions of this study are: (1) The mean frequencies of aberrations changed with fixation time. (2) The number of cells scored as aberrant by different laboratories was very similar, but there was variability in the number of aberrations scored per aberrant cell. (3) The differences in the frequencies of aberrations between laboratories were minimal when the scoring was restricted to the first major peak of mitotic activity and sufficient cells were scored. It is concluded that using controlled experimentals conditions, human peripheral blood lymphocytes can effectively be used as a reliable biological dosimeter for absorbed radiation dose.

Argentina↗
PubMed1982

Cell death (apoptosis) in the mouse small intestine after low doses: effects of dose-rate, 14.7 MeV neutrons, and 600 MeV (maximum energy) neutrons.

The production of dead (apoptotic) cells by low doses of gamma-rays was independent of dose-rate between 0.27 and 450 cGy per min. The r.b.e. for doses of 14.7 MeV neutrons between 1 and 15 cGy was about 4, and for neutrons generated by bombarding a beryllium target with 600 MeV protons the r.b.e. was about 2.7. The dose-incidence curves for all three radiation types reached a plateau at about 3-4 dead cells per crypt section, and this occurred at about 20-40 cGy of gamma-rays. These curves are compatible with exponential survival of the cell population at risk (D0 of 24 cGy for gamma-rays, 6 cGy for 14.7 MeV neutrons and 9 cGy for 600 MeV neutrons). Since the dose-response is exponential there is no indication of much higher r.b.e. values at very low doses, a point of concern in radiation protection. The spatial distribution of dead cells in the crypt was similar after doses of gamma-rays or neutrons, indicating that the same population of target cells was affected in both cases.

Animals↗
PubMed1982

Erythrocyte superoxide dismutase, catalase and glutathione peroxidase in glucose-6-phosphate dehydrogenase deficiency.

Glucose-6-phosphate dehydrogenase (G-6-PD) deficient erythrocytes are particularly sensitive to oxidant stress. In order to evaluate if these cells are protected against oxidant damage, we assayed the antioxidant enzymes superoxide dismutase (SOD), catalase and glutathione peroxidase (GSH-Px) in erythrocytes of G-6-PD deficient (hemizygous and heterozygous) subjects. Normal levels of antioxidant enzymes were found in all subjects examined both with positive and negative histories of haemolytic crisis after fava bean or drug ingestion. In contrast, high levels of catalase and GSH-Px were found in a small group of G-6-PD deficient subjects (hemizygous and heterozygous) with beta-thalassaemia trait, probably by reason of the chronically enhanced oxidant stress which is present in beta-thalassaemia.

Adolescent↗
PubMed1982

Propranolol, atenolol, and trifluoperazine reduce the spontaneous occurrence of meiotic diploid products in Saccharomyces cerevisiae.

The effect of atenolol, propranolol, trifluoperazine, and caffeine on the occurrence of meiotic diploid and disomic products in Saccharomyces cerevisiae was investigated. We demonstrated that atenolol, propranolol, and trifluoperazine reduce the occurrence of meiotic diploid products and that propranolol also slightly decreases the spontaneous frequency of disomics. On the other hand, caffeine appears to be a powerful inducer of diploid meiotic products, but also shows a lesser effect on disomic induction. Since spontaneous or caffeine-induced diploids arise from a failure of the second meiotic division, it appears that the target of these drugs is at the beginning of the second meiotic division. The only common effect of trifluoperazine and propranolol, mainly investigated in mammals, was an inhibition of calmodulin activity via direct interaction. We tend, therefore, to believe that calmodulin activity must be a crucial point for the second meiotic division to begin. The increased induction of diploids, due to caffeine, may be interpreted as a consequence of an increased cyclic AMP level.

Atenolol↗
PubMed1982

[Surgical indications in treatment of chronic bronchial suppurations].

The Authors report their experience (22 operations) concerning chronic bronchial suppurations of surgical interest. During the period considered (1964 - April 1982), among many pathological processes capable of conditioning a chronic bronchial suppuration, it has been observed a progressive decrease of "primitive" bronchiectasis and a percentage increase of "secondary" ones. Surgical treatment, unquestionably required in cases of cystic malformation or secondary obstruction, is now restricted to "primitive" cases with well-limited bronchiectasis or with complications (hemoptysis). Surgical therapy performed in these cases appears to grant good results both immediately (O% surgical mortality) and in the future.

Adolescent↗
PubMed1981

[Methemoglobinemia; a description of a case of NADH methemoglobulin reductase deficiency].

A case of NADH-methaemoglobin-reductase deficiency in a 64 year old man with marked cyanosis and without evidence of cardiac or pulmonary diseases is reported. The level of methaemoglobin was 36% and reached 25% after treatment with ascorbic acid. Erythrocyte NADH-methaemoglobin-reductase activity was only 5% of normal value. Some erythrocyte biochemical and enzymatic characteristics have been evaluated. A family study has also been carried out. Our patient has been considered homozygous for NADH-methaemoglobin-reductase deficiency.

Cytochrome-B(5) Reductase↗
PubMed1981

[Investigations on the individual-region distribution of adipocyte diameters by means of advanced statistical methods].

The dimensional distributions of the adipocytes in Equus caballus in many subjects and in many regions have been studied: such distributions turn out to be in good approximation galtonian ones. Furthermore, all the logarithm populations of the cell diameters have significantly the same variance. The used statistical methods (ANOVA two way with replications, and TUKEY -test) indicate an extremely significant different among the various regions (the smallest cells are in the supra-orbital fossa, the greatest ones are in the abdominal subserous floor).

Adipose Tissue↗
PubMed1981

GLC-mass fragmentographic determination of saccharin in biological fluids.

A specific and sensitive method is described for the determination of saccharin in biological fluids. The compound is extracted as its methyl derivative following a salt-solvent pair procedure and assayed by GLC with either flame-ionization or mass fragmentographic detection using ethylated or trideuteromethylated saccharin, respectively, as the internal standard for quantitation. Detector response was linear over concentrations of 50 mg/ml--10 micrograms/ml with multiple-ion detection mass fragmentography and from 2 micrograms/ml up to milligram levels with flame-ionization detection. Interference from endogenous substrates was never observed. Plasma kinetics and urinary elimination of saccharin in healthy human volunteers given the sweetener orally, acutely (50 mg/60 kg of body weight) or for 5 days (130 mg/60 kg of body weight/day divided over the three main meals), also are reported.

Body Fluids↗
PubMed1981

Body fluid volumes in the spontaneously hypertensive rat.

1. Plasma volume, packed cell volume (PCV), blood pressure, extracellular fluid volume (ECFV) and evans blue disappearance rate were measured in conscious spontaneously hypertensive rats and in weight-matched Wistar normotensive rats. 2. Over the weight range studied (250-350 g), plasma and blood volumes were significantly lower in the spontaneously hypertensive rat. Extracellular fluid volumes were similar in the two groups. PCV and Evans blue disappearance rates were significantly higher in the spontaneously hypertensive rat. 3. Negative correlations were obtained between plasma volume and mean arterial pressure and between the plasma/interstitial fluid volume ratio and mean arterial pressure. 4. The normal extracellular fluid volume and the lack of correlation with mean arterial pressure excludes volume expansion as a pressor mechanism during the established phase of hypertension in the spontaneously hypertensive rat.

Animals↗