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D Del Principe

Publications and source records attributed to D Del Principe.

At least 55 records · Page 3Linked to original sources
PubMed1981

[Blood platelet oxygen consumption in pituitary dwarfs (author's transl)].

Oxygen consumption in blood platelets of 14 pituitary dwarfs aged from 2 to 8 years was investigated before and after a 2 months' treatment with growth hormone (GH). No significant difference was found between dwarfs and control subjects in respect of basal platelet oxygen uptake (4.0 +/- 3.8 mmol O2/10(9) platelets/min in dwarfs as against 6.4 +/- 4.1 in controls), but the abrupt increase in oxygen consumption induced by thrombin was significantly reduced in dwarfs (4.3 +/- 4.1) as compared with controls (12.3 +/- 7.6; p less than 0.01). During GH treatment, however, the dwarfs' response to thrombin stimulation was similar to that of controls. Since dwarfs had normal platelet malonyldialdehyde production, it is likely that the mitochondrial component of thrombin-induced high oxygen consumption was deficient. These results suggest that blood platelets may contribute to the protective effect of GH deficiency against atherosclerosis.

Blood Platelets↗
PubMed1981

The in vitro inhibitory effect on thrombin by 2,3-diphosphoglycerate.

Thrombin incubated with 2,3-diphosphoglycerate (150 nmol 2,3-DPG/1 NIH thrombin unit) lost up to 70% of its clotting activity, whereas the esterase activity remained unchanged. No fibrinopeptide release by thrombin was observed in the presence of 2,3-DPG. The fibrin polymerization was normal. By chromatography on Amberlite IRC-50, alpha-thrombin was eluted at pH 8.0. In presence of 2,3-DPG, alpha-thrombin was not eluted. Likely, 2,3-DPG can interfere with thrombin.

Animals↗
PubMed1980

Labelling of blood platelets with stable tracers.

Half-time values of platelets labelled with stable rubidium are compared to those of platelets labelled with Cr51. Platelets labelled with stable rubidium are assayed by a very simple version of the X-Ray fluorescence equipment. The mean quantity of rubidium incorporated by the cells is of about some microgram Rb per ml blood. The in vitro half-time of human Rb labelled platelets stored at 22 degrees C is 41.2 +/- 3h compared with the value 44.8 +/- 3h for platelets labelled with Cr51, as deduced by six experiments. The in vivo half-time of rabbit platelets labelled with stable rubidium is 22 +/- 3h compared with the value 18 +/- 3h of platelets labelled with Cr51; ten experiments were carried out.

Animals↗
PubMed1979

Malonyldialdehyde formation, oxygen consumption, fatty acid composition in newborn platelets stimulated by thrombin.

The release reaction, the formation of malonyldialdehyde (MDA), the pattern of oxygen consumption, and the variation in fatty acid composition after addition of thrombin (1.67 U/ml) have been investigated in newborn platelets, comparing the obtained data with analogous values showed by adult platelets assumed as normal controls. Newborn platelets showed a release reaction 20% lower than that of controls. MDA formation, even in the presence of NEM and the burst in oxygen consumption, resulted to be similar in newborn and adult platelets (p greater than 0.3); the burst was also similar after the addition of thrombin (10 U/ml) in the presence of antimycin and aspirin. The ratio between formed MDA and oxygen consumption was 1:10 in adult platelets while it was 1:15 in those of newborns. The study of fatty acid composition demonstrated that in newborn platelets at rest, arachidonic acid is significantly in a higher concentration than in controls and that it decreases after stimulation with thrombin. It is concluded that the pathway of prostaglandins is normally stimulated by thrombin in newborn platelets.

Adult↗
PubMed1979

In vitro effect of levamisole on oxygen consumption and survival of platelets.

Levamisole at a concentration of 10(-3)M inhibits the oxygen consumption of resting platelets, the thrombin induced burst and the platelet aggregation induced by ADP. At the concentration of 10(-7)M it exerts still an inhibitory activity of the thrombin induced burst, but it does not inhibit neither the basal oxygen consumption nor the platelet aggregation. At every tested concentration platelet survival in the presence of levamisole is comparable to that of controls. Levamisole moreover, together with theophylline and glucagon, shows a synergistic inhibiting influence toward the burst of oxygen consumption. Our data suggest that levamisole may act by producing an enzymatic block of cyclo-oxygenase.

Adenosine Diphosphate↗
PubMed1978

In vitro labeling of platelets with stable rubidium compounds.

It is a common practice in diagnostic hematology to mark blood cells with radioactive tracers, such as 51Cr, 55Fe, 75Fe, etc., to determine their life-span and study their metabolism. A program has been started to verify the possibility of marking blood cells with stable indicators, assayed by radioisotope-induced X-ray fluorescence analysis. All elements may be considered as indicators aggregating to blood cells, and for in vivo measurements, which are not toxic in the quantities injected, calculated on the basis of the limit of detection of the technique. In this study platelets were marked with a very small quantity of stable compounds of rubidium, a potassium analog. Measurements were carried out in vitro on platelets of normal subjects and in vivo on platelets of rats and rabbits. Several survival curves were deduced and life-span values obtained in accord with previously reported values.

Animals↗
PubMed1977

Cyanide insensitive oxidase in platelets of newborn infant.

The authors studied the behaviour of neonate platelet O2 consumption after the addition of pyridine nucleotide compared to adult controls. O2 consumption of neonate platelets after NADH addition was 103,2 millimicronmol O2/10(9)/hr (SE = 24,74) and in adult controls 188,8 millimicronmol O2/10(9)/hr (SE = 36,46). After the addition of NADPH O2 consumption was, respectively, 233,5 millimicronmol (SE = 46,29) and 218,3 millimicronmol (SE = 30,01).

Blood Platelets↗
PubMed1977

The effect of 2,3-diphosphoglycerate on oxygen consumption burst in thrombin-stimulated platelets.

2,3-Diphosphoglycerate (2,3-DPG) modifies platelet function; it diminishes aggregation and the release reaction. The hypothesis that this occurs through a modification of the intracellular level of cyclic AMP or through an alteration in the synthesis of prostaglandins has been proposed. Since the release reaction occurs simultaneously with a burst in the consumption of oxygen, the authors have studied the effect of 2,3-DPG on oxygen consumption after the addition of thrombin with or without the addition of substances which modify platelet metabolism (aspirin, theophylline, glucagon, etc.). It was observed that 2,3-DPG diminishes oxygen consumption induced by thrombin. This mechanism alters the platelet membrane function.

Adult↗
PubMed1977

Disseminated arthritis and osteitis by Candida albicans in a two month old infant receiving parenteral nutrition.

The case of a two-month -old female infant, who after a severe diarrhoea treated with prolonged intravenous infusion in peripheral veins alternated with total parenteral feeding, developed a Candida albicans septicemia (accompanied by disseminated intravascular coagulation syndrome) is reported. The course of her disease was also complicated by multiple foci of osteoarthritis in both knees, in the left hip and in several long-bones. Radiographically the foci of Candida osteitis appeared as fine erosion of the cortex and minute round areas of osteolysis in the spongiosa, surrounded by a rim of perifocal sclerosis. During the acute stage of Candida sepsis a transitory cellular immunodeficiency was present. Treatment of Candida infection by 5-fluorocytosine was followed by complete recovery.

Arthritis, Infectious↗
PubMed1976

Oxygen consumption in platelets of newborn infants before and after stimulation by thrombin.

The authors compared the oxygen consumption in platelets from the umbilical cord blood of 36 healthy newborn infants with that of 27 adult subjects, before and after thrombin addition (1.67 U/ml). Oxygen consumption at rest was 6 mumol/10(9)/min in adult control platelets and 5.26 in newborn infants. The burst in oxygen consumption after thrombin addition was 26.30 mumol/10(9)/min in adults and 24.90 in infants. Dinitrophenol did not inhibit the burst of O2 consumption in platelets in 8 out of 10 newborn infants, while the same concentration caused a decrease in 9 out of 10 adult subjects. Deoxyglucose inhibited the burst in O2 consumption in newborn infant and adult platelets by about 50%. KCN at the concentration of 10(-4) M completely inhibited basal oxygen consumption but did not completely inhibit the burst after thrombin. At the concentration of 10(-3) M, it inhibited both basal O2 consumption and the burst in infants and adult subjects.

Blood Platelets↗