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Biomedical subjects

A Marini

Publications and source records attributed to A Marini.

At least 127 records · Page 7Linked to original sources
PubMed1985

Trials of high frequency jet ventilation in preterm infants with severe respiratory disease.

Nine preterm newborn infants were maintained on conventional mechanical ventilation for respiratory diseases were given high frequency jet ventilation in the same inspired FiO2 for short periods (10-120 min). Lower mean airway pressures were used in high frequency jet ventilation (0.70 +/- 0.2 kPa versus 0.96 +/- 0.2 kPa in intermittent positive pressure ventilation), and peak inspiratory pressures were reduced from 2.06 +/- 0.4 to 1.38 +/- 0.24 kPa. Respiratory and haemodynamic data were compared with those obtained in intermittent positive pressure ventilation, PaO2 and PCO2 were similar, while an increase in pH and reduction of central venous pressure were observed during high frequency jet ventilation. This preliminary study indicates that high frequency jet ventilation provides good ventilatory support, at least for short periods, with reduced airway pressures, and could be a promising technique for prevention of acute and chronic pulmonary barotrauma.

Hemodynamics↗
PubMed1985

Modifications in the phagocytosis of human neutrophils induced by vinblastine and cytochalasin B: the effects of lithium.

The effects of lithium on the microtubular and microfilament systems of neutrophil granulocytes is described. The phagocytic capacity of human neutrophils was reduced or inhibited by using vinblastine or cytochalasin B. Lithium at concentrations ranging from 0.5 to 2.0 mEq/l proved to be capable of antagonising the action of vinblastine, whereas the action of cytochalasin B was found to be unaffected by lithium. Based on the antagonising effect of lithium on vinblastine-induced inhibition of phagocytosis, it is suggested that lithium acts--at therapeutically achievable levels--on the microtubular system of neutrophils, possibly through modulation of cyclic AMP levels.

Cytochalasin B↗
PubMed1984

Effects of lithium carbonate on leukocyte functions in chronic benign neutropenia.

The effects of lithium carbonate on leukocyte functions in a case of chronic benign neutropenia are presented. Lithium was able to induce leukocytosis and to bring about increases in chemotaxis, marrow granulocyte reserve test and phagocytosis. After lithium interruption, leukocyte functions returned to initial values. Some hypotheses are advanced to account for lithium action.

Adult↗
PubMed1983

Angiotensin II: a releaser of PGI2 from fetal and newborn rabbit lungs.

Angiotensin II (AII) induces generation of prostacyclin (PGI2) in rabbit lung in vitro at different ages, i.e., fetus, newborn and adult. Particularly, neonatal rabbit lungs display a pattern of sensitivity to AII in producing PGI2, measured as 6-oxo-PGF1 alpha, which seems to be higher than that observed in fetal lungs. The PGI2 release appears to be specific for AII stimulation since the vasoconstriction induced by noradrenaline and ergotamine was not associated with generation of this lipidic material. The inability of PGI2 to relax the extralobar pulmonary artery in the newborn suggests that the lung microcirculation is the most likely site where the vasodilating and antiaggregatory functions of PGI2 may have a physiological role.

6-Ketoprostaglandin F1 alpha↗
PubMed1983

EEG sleep patterns and endogenous opioids in infants of narcotic-addicted mothers.

The early symptoms of brain dysfunction in infants born to heroin-addicted mothers were studied during the first month of life by a multimethod approach. Neurological examination and polygraphic EEG studies of sleep patterns were performed; concomitantly plasma levels of beta-endorphin and met-enkephalin were measured. Whenever possible, these parameters were correlated with each other and with the severity of the withdrawal syndrome. While the neurological examination of addicted newborns was almost negative, altered sleep cycles with a decrease in active sleep and an increase in quiet sleep were noted together with a marked increase in the plasma concentration of the endogenous opioid peptides. Furthermore, instead of reverting to the adult values (as for normal babies), the peptides remained at high levels up to the 40th day of life.

Brain↗
PubMed1983

Plasma beta-endorphin, beta-lipotropin, and met-enkephalin concentrations during pregnancy in normal and drug-addicted women and their newborn.

Most studies of plasma beta-endorphin concentrations in pregnant women show that these are highly elevated. This might indicate a role for opiate peptides during pregnancy and in the fetus-mother relationship. We measured plasma beta-endorphin, beta-lipotropin, and met-enkephalin concentrations in normal and drug-addicted women during pregnancy, labor, and delivery, and in their newborn infants. Peptides were measured by RIA after extraction and concentration on silica columns and separation by high pressure liquid chromatography. In both normal and drug-addicted mothers we found an increase in plasma beta-endorphin during pregnancy, without a concomitant increase in plasma beta-lipotropin or metenkephalin. Only beta-lipotropin increased dramatically in both groups at delivery, whereas beta-endorphin and met-enkephalin remained unchanged. Peptide concentrations in umbilical plasma were similar to those in peripheral plasma of the mothers. On day 1 of life plasma beta-endorphin, beta-lipotropin, and met-enkephalin concentrations in the newborn from normal mothers were higher than in nonpregnant adult subjects and gradually decreased toward normal adult values by day 5 of life. Plasma beta-endorphin, beta-lipotropin, and met-enkephalin concentrations of newborn infants of drug-addicted mothers increased dramatically on day 2 and 3 of life, up to 1000-fold the concentrations of normal adults, and remained elevated up to 40 days after birth. In conclusion, beta-endorphin, beta-lipotropin, and met-enkephalin concentrations during pregnancy are not affected by drug addiction, whereas in the newborn of drug addicted mothers concentrations of these compounds are markedly increased.

Adult↗
PubMed1982

Gastric inhibitory polypeptide release after oral glucose: relationship to glucose intolerance, diabetes mellitus, and obesity.

Hypersecretion of immunoreactive gastric inhibitory polypeptide (IRGIP) has been reported previously in patients with diabetes mellitus (DM) and obesity. To ascertain the relative contribution of glucose intolerance and obesity to the abnormalities of IRGIP secretion, 114 subjects were studied during a standard oral glucose (75 g) tolerance test; responses of glucose, insulin, C-peptide, IRGIP, and glucagon were evaluated. The subjects were divided into six subgroups according to body weight and the degree of glucose intolerance. In normal weight subjects, the IRGIP response to oral glucose was significantly higher in the patients with impaired glucose tolerance (IGT) and DM than in the healthy control subjects (P less than 0.05). In the obese subjects, no significant differences in mean IRGIP responses could be detected among control, IGT, and DM subjects. In spite of similar IRGIP responses, the obese IGT patients did release more insulin than the obese control subjects, suggesting that incretin factors other than GIP may be operative in this condition. When obese and nonobese patients were compared, the obese subjects with normal glucose tolerance released a greater amount of IRGIP and insulin than the normal weight controls, whereas no significant difference between obese and nonobese could be found within the IGT and DM groups. We conclude that in the absence of obesity, glucose intolerance may induce IRGIP hypersecretion. On the other hand, obesity is associated with IRGIP hypersecretion, and glucose intolerance has no further effect, indicating a different pathogenetic mechanism for the IRGIP abnormalities. In both the obese and nonobese diabetic groups, IRGIP hypersecretion was associated with a failure of plasma glucagon levels to fall after oral glucose; this effect might be related to the glucagonotropic action of this peptide.

Adult↗
PubMed1981

Prostacyclin (PGI2) generation in lungs of fetal and newborn rabbit.

Perfused lungs from fetal (26-28 days of gestation) and newborn rabbits preferentially transform arachidonic acid into a substance which mimics PGI2 activity on different isolated tissues in cascase. These data support the hypothesis that antiplatelet and vasodilating vasodilating activity of PGI2 generated in the lungs may contribute to the characteristics of the fetal circulation.

Animals↗
PubMed1980

Plasma catecholamines and plasma renin activity at birth and during the first days of life.

1. Plasma noradrenaline and adrenaline concentrations and plasma renin activity were measured in 21 mothers at delivery and in their babies at birth (umbilical cord blood) and on days 1 and 5 of extrauterine life. 2. At birth plasma renin activity was significantly higher in the newborn than in mothers. Plasma renin activity increased further, but not significantly, on day 1 of life and significantly decreased on day 5. On day 5, 10 min head-up tilting caused no change in plasma renin activity. 3. Plasma noradrenaline in the newborn was higher than in mothers at birth and significantly decreased thereafter. Plasma adrenaline levels at birth were similar in the newborn and their mothers and significantly lower in the newborn in subsequent days. Tilting caused no increase in either plasma adrenaline or noradrenaline levels. 4. No correlation was found between plasma noradrenaline and adrenaline levels and plasma renin activity, or between noradrenaline, adrenaline or plasma renin activity and blood pressure.

Blood Pressure↗
PubMed1980

Multiexponential elimination of gentamicin. A kinetic study during development.

The long-term disposition of gentamicin (up to 100-240 h) was studied in 13 premature newborns (33 weeks mean gestational age) and in 7 infants and children (1 month to 8 years). The data fitted bi- or triexponential curves with terminal half-lives averaging 51 and 37 h. Newborns showed lower values of body clearance, central compartment and steady state volumes of distribution than infants and children (respectively, 12.8 vs. 50.4 ml/min/1.73 m2, 9.03 vs. 17.5 liters/1.73 m2, and 15.7 vs. 35.5 liters/1.73 m2). The ratio between the amount of gentamicin predicted at steady state in the tissue compartment and in the total body was also significantly lower in newborns than in the older group (0.4 vs. 0.52). These data provide pharmacokinetic demonstration of an age dependence in gentamicin tissue distribution and excretion during the early stages of human development.

Adult↗