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Biomedical subjects

G Clementi

Publications and source records attributed to G Clementi.

71 records · Page 4Linked to original sources
PubMed1981

Possible role of prolactin in the modification of medial basal hypothalamic glutamic acid decarboxylase activity.

The effects of acute and chronic injections of haloperidol, sulpiride and apomorphine on serum prolactin (PRL) levels and medial basal hypothalamus (MBH) glutamic acid decarboxylase (GAD) activity were investigated in male rats. Parallel changes in PRL and GAD activity were observed in acutely treated animals. Conversely, a return to normal of the GAD activity associated with high plasma PRL levels was induced by chronic haloperidol and sulpiride treatment. Results are discussed in the light of the possible existence of a hypothetical PRL-gamma-aminobutyric acid (GABA) subsidiary feedback loop.

Animals↗
PubMed1981

In vivo and in vitro interference of phosphatidylserine liposomes on prolactin secretion in the rat.

The effect of sonicated suspensions of phosphatidylserine (PS), an acidic phospholipid, was investigated on prolactin secretion utilizing in vivo and in vitro approaches. Acute and chronic administration of PS reduced plasma prolactin levels during different phases of circadian rhythms. The phospholipid was able to inhibit the plasma prolactin surge, which occurs in cycling female rats on the afternoon of proestrus. The time course of PS on prolactin secretion was characterized by a short latency (15 min) and a long duration of action (6 h). In rats with hypothalamic deafferentation PS partially reduced the increase of circulating prolactin induced by pretreatment with alpha-methyltyrosine. An inhibition of prolactin release was observed if anterior pituitary glands were incubated in presence of PS. This effect was prevented by the addition of the dopamine antagonist sulpiride to the medium. In conclusion, PS decreases prolactin secretion both in vivo and in vitro. The inhibition of the hormone secretion appears to be due to the action of PS at the level of the pituitary; however, a concomitant stimulatory action on the turnover of the tuberoinfundibular neurons cannot be ruled out.

Animals↗
PubMed1981

[Radical surgical correction of tetralogy of Fallot: comparison between the effects of isoproterenol in IPPV and spontaneous-ventilation after surgical treatment (author's transl)].

The AA. studied 7 patients affected by Tetralogy of Fallot; their ages were between 4 and 20 years. At the end of the radical surgical correction we studied their haemodynamics. From the analysis of the data we found that using beta-agonist drugs (Isuprel 0.05 mcg x Kg x min) there were no change in the haemodynamic data when the patients were kept under positive pressure ventilation. In spontaneous ventilation we observed that the same data can raise the cardiac index of 22%, lower the total peripheral resistances (20%) and the pulmonary vascular resistances (8%) and the intrapulmonary shunt (8%).

Adolescent↗
PubMed1978

Cardiovascular monitoring with special emphasis on mixed venous oxygen measurements.

With the advent of complicated surgical procedures the need for invasive hemodynamic monitoring has taken a prominent place in the management of patients. This has resulted in improved morbidity and mortality in overall patient care. Along with conventional monitoring of heart rate, arterial pressure and central venous pressure, the information about the function of the left heart is essential. This paper describes the usefulness of Swan-Ganz catheter (SG catheter) during intensive care. The purposes of the study is to determine the relationship between mixed venous oxygen saturation measurement, peripheral skin temperature and volume replacement in the immediate postoperative period, as well as the need for prolonged mechanical ventilation in shocked patients.

Blood Pressure↗
PubMedDate not supplied

Parathyroid hormone fragment 1-34 and anti-inflammatory effect.

We have studied the possible activity of the rat parathyroid hormone fragment 1-34, peripherally or centrally injected, on the vascular permeability induced by local administration of croton oil. Our study considered also the possible interference of parathyroid hormone fragment 1-34 on the release of histamine by mast cells and on the content of histamine in paw tissue. Parathyroid hormone fragment 1-34 significantly reduced the increase in vascular permeability produced in mice by local croton oil injection, as well as the serotonin-induced paw edema in the rat. These effects of parathyroid hormone fragment 1-34 were present only after peripheral administration. At the dose of 3.3 micrograms/kg, it decreased the histamine content in paw tissue. Peripheral administration of a calcium antagonist, such as nimodipine, at the dose of 50 micrograms/kg, or a metal-chelating agent, such as ethylene-diaminetetraacetic acid, at the dose of 10 micrograms/kg, antagonized the anti-inflammatory effect of parathyroid hormone fragment 1-34. Moreover, at 10-100 microliters/ml it significantly decreased the histamine release by mast cells.

Anaphylaxis↗
PubMedDate not supplied

The effects of acetyl-l-carnitine on experimental models of learning and memory deficits in the old rat.

Experimental models of learning and memory deficits in aged rats can be studied by means of behavioural tests that provide an important tool for evaluating the effect of drugs on these parameters. Active and passive avoidance tests showed a clear impairment of learning and memory capacity of old rats. These tests were also used to study the behavioural effect of acetyl-l-carnitine in aged rats. The subchronic treatment with this drug was followed by a significant improvement of acquisition and retention of avoidance responses, indicating a facilitation of learning and memory capacity of aged rats.

Acetylcarnitine↗
PubMedDate not supplied

Cardiorespiratory effects of protamine sulphate in man: intra-aortic vs intra-right atrial rapid administration after cardiopulmonary bypass.

The effects of protamine sulphate on several cardiorespiratory variables were studied under clinical situations in twenty patients following cardiopulmonary bypass. Because recent reports suggest that there may be advantages of intra-aortic versus intra-venous administration we prospectively evaluated cardiorespiratory features 1 and 10 minutes after rapid administering of protamine sulphate either into the aortic arch (through a catheter percutaneously inserted via the radial artery for monitoring purposes) or into the right atrium. Significant variations in some parameters were found in the patients receiving the drug via the aorta, such as a drop of systemic vascular resistances (p less than 0.05), of coronary perfusion pressure (p less than 0.05), of aortic systolic pressure (p less than 0.01), of diastolic (p less than 0.01) and mean blood pressure (p less than 0.05) and a rise in the respiratory quotient (p less than 0.05). It is concluded that the results do not confirm the superior safety of intra-aortic administration of protamine particularly when replenishment of intravascular volume is not provided.

Analysis of Variance↗
PubMedDate not supplied

Effects of flunarizine on experimentally-induced convulsions in animals.

D,L-allylglycine-induced seizures in rats were antagonized by flunarizine and other antiepileptic drugs. In this respect, the spectrum of flunarizine appears to be similar to that of diphenylhydantoin. A behavioral analysis of the effects of various drugs on amygdaloid kindled rats showed that flunarizine exerts anticonvulsive effects in this model with an ED50 of 42.8 mg/kg. Furthermore, flunarizine (1, 5, 25 and 50 mg/kg i.p.) reduced seizure parameters in rats injected with strychnine or pentetrazol. In this case, flunarizine reduced seizure intensity and increased the percentage of survival. In another study on genetically epileptic beagles, flunarizine significantly affected the REM and deep slow-wave sleep latencies.

Allylglycine↗
PubMedDate not supplied

[Propofol in coronary diseases. Haemodynamic evaluation of some anesthetic regimes].

The haemodynamic effect of two regimens of propofol-fentanyl anaesthesia versus a standard isoflurane-fentanyl anaesthesia were compared perioperatively in 30 patients with good left ventricular function undergoing coronary artery bypass grafting. Anaesthesia was induced in all patients with fentanyl 14 micrograms/kg, pancuronium 0.1 mg/kg, and thiopental 1 mg/kg. Anaesthesia was maintained: in 10 patients with a constant propofol infusion of 200 micrograms/kg/min during the pre-bypass period and fentanyl boluses of 1 mg when required (PH Group); in 10 patients with a variable propofol infusion (from 43.09 to 22.42 micrograms/kg/min) during the pre-bypass period and a fixed infusion of 10.47 micrograms/kg/min during the post-bypass period (PL group) in 10 patients with a 1% isoflurane administration throughout the intraoperative period (F Group). The analgesia in the PL and F Groups was obtained with a fentanyl infusion of 0.3 microgram/kg/min during the prebypass period, 0.11 microgram/kg/min during the postbypass period. PL Group patients received 0.06 microgram/kg/min of fentanyl during the first three hours of the intensive care unit (TI) stay. The PL Group showed a significant better haemodynamic control of oxygen consumption indexes; PH Group patients had a major myocardial depression, routinely requiring the use of cardiokinetic agents in the post-bypass period. Intraoperative opioid consumption was similar in all Groups whereas the F Group showed a significantly higher fentanyl requirement during the TI period.

Anesthetics, General↗