Biomedical subjects

M Maurelli

Publications and source records attributed to M Maurelli.

62 records · Page 4Linked to original sources

PubMedDate not supplied

Centrally administered N-terminal fragments of ACTH (1-10, 4-10, 4-9) display convulsant properties in rabbits.

Electroencephalographic and behavioral effects of the following ACTH fragments: 1-4, 4-9, 4-11, 1-10, 4-10, 1-13, 1-17 and 1-24 were studied in rabbits. Sequences 4-9, 1-10 and 4-10 displayed some epileptic properties, i.e., they induced epileptic seizures (only electrographic or also behavioral) or increased hippocampal spiking. The 4-9 sequence seemed to be the common sequence responsible for these proconvulsant effects. The possible involvement of the enkephalinergic system is discussed.

Adrenocorticotropic Hormone↗

PubMedDate not supplied

Relationship between prothrombin activation fragment F1 + 2 and serum cholesterol.

Plasma levels of fibrinogen, factor VIIc and prothrombin fragment F1 + 2, a marker of thrombin generation in vivo, were studied in 68 subjects with serum total cholesterol (TC) levels between 135 and 349 mg/dl but without clinical evidence of cardiovascular disease and other atherosclerotic risk factors. F1 + 2 plasma levels were directly correlated with TC (p < 0.0004), low-density lipoprotein cholesterol (LDL-C; p < 0.0018) and factor VIIc (p < 0.024). Thirty-five subjects with TC greater than 249 mg/dl (median value of the whole group) showed higher levels of F1 + 2 (p < 0.0001) and fibrinogen (p < 0.0015) than those with TC lower than 249 mg/dl. In subjects with TC > 249 mg/dl and F1 + 2 > 1.2 nM (median value of the whole group), a cholesterol-lowering drug (simvastatin) was able to reduce F1 + 2 (p < 0.009) as well as TC and LDL-C. This study shows a relationship between serum cholesterol and the rate of thrombin generation supporting the hypothesis that a hypercoagulable state may occur in hypercholesterolemic subjects before the onset of clinical evidence of atherosclerotic cardiovascular disease.

Adult↗

PubMedDate not supplied

[Single lung transplantation retrospective analysis of intraoperative cardiovascular problems].

BACKGROUND: Analysis of haemodynamic problems during single-lung transplantation and of methodologies employed for their treatment. METHODS DESIGN OF THE STUDY: clinical retrospective study. SETTING: General University Hospital. PATIENTS: patients with irreversible lung disease, either parenchymal or vascular, undergoing single lung transplantation. INTERVENTIONS: recording of circulatory failure episodes and treatment with pharmacologic support or cardiopulmonary bypass. Modifications occurring during the study period with respect to drugs administered. Evaluation of the consequences of cardiopulmonary bypass on the postoperative outcome, namely on the duration of mechanical ventilation and length of stay in the intensive care unit. RESULTS: During the last 9 years 69 single-lung transplantations have been performed. In 50% of cases a pharmacologic support has been employed; the drug association dobutamine/nitroprusside has been gradually replaced by the association norepinephrine/nitric oxide for the treatment of right ventricular failure. Twenty patients required cardiopulmonary bypass and this caused a significant increase of the duration of mechanical ventilation and length of stay in the intensive care unit. CONCLUSIONS: Hemodynamic changes during lung transplantation are complex and often severe, leading to a clinical status of right ventricular failure, that sometime requires a mechanical circulatory support. The introduction of nitric oxide in clinical practice significantly contributed to the optimization of intraoperative cardiocirculatory profile of patients, leading to a reduction in the use of vasoactive drugs and cardiopulmonary bypass.

Adolescent↗

PubMedDate not supplied

[The neuroendocrine aspects of chronic alcoholism: the effect of alcohol intake and its withdrawal].

Neuroendocrine dysfunctions, in part similar to those found in depression, are present in chronic alcoholism. The aim of this investigation was to evaluate the effects of chronic alcohol intake on cortisol secretion in basal conditions, after dexamethasone (DXT) suppression or corticotropin (ACTH) stimulation in 10 alcoholic men, during active drinking and after two weeks of alcohol withdrawal. The 24-hour, day- and night-time urinary cortisol and melatonin levels, and the effects of thyrotropin releasing hormone (TRH) on thyrotropin (TSH) and prolactin (PRL) secretions were studied in the same subjects. The data were correlated to the scores obtained by the Hamilton Rating Scale for depression and compared to those found in healthy subjects. Increased cortisol levels and the lack of DXT suppression of cortisol secretion are considered to be alcohol-dependent inasmuch as they disappear in most patients after alcohol withdrawal. The cortisol response to ACTH 1-24 infusion measured before and after alcohol withdrawal was similar in the patients we studied; moreover no significant difference was found between patients and controls. The increment of urine free cortisol levels in active alcoholics was not statistically significant. Urine cortisol levels became similar to those of the control subjects after alcohol withdrawal. The increased diurnal values of urine melatonin and the inversion of the physiological ratio between nocturnal and diurnal levels observed during alcohol intake became normal upon alcohol withdrawal. The TSH and PRL responses after the administration of 50 or 200 micrograms TRH were higher in alcoholics than in controls, while a blunted response is known to occur in depression.

Adult↗

PubMedDate not supplied

Alcohol interactions with typical and atypical antidepressants.

Selected parameters of central nervous system function have been examined in rabbits and mice given ethyl alcohol (ET) in combination with antidepressant drugs with different pharmacological profiles. A significant prolongation of the ET-induced loss of righting reflex was observed in mice treated with amitriptyline, 3 mg/kg, or trazodone, 8 mg/kg, injected intraperitoneally. The same drugs failed to cause narcosis when given alone to mice at doses up to 40 (amitriptyline) and 100 (trazodone) mg/kg. Rabbits given single 5 mg/kg IV doses of amitriptyline or trazodone exhibited a synchronous EEG pattern with an increase in spectrum total power that became more pronounced after IV injection of a low dose of ET (0.2 g/kg). The increase in the spectrum total power after ET was significantly greater in rabbits given trazodone than in those given amitriptyline. No significant interactive effects were observed in animals receiving combinations of ET with viloxazine, bupropion or fluvoxamine.

Animals↗

PubMedDate not supplied

[EEG and autonomic effects of centrally administered galanin in the rabbit].

The effects of centrally administered galanin (10 and 20 mcg) on the EEG, somatic behaviour and some autonomic parameters have been studied in unanesthetized rabbits. In this species the peptide induced a dose related increase in electrocortical power spectrum density and behavioural sedation. Autonomic changes, consisting in moderate hyperthermia and bradypnea, were seen only after the highest dose of the peptide. These data support a central action of the peptide and suggest a role for galanin as sedative neuropeptide.

Animals↗

PubMedDate not supplied

[Effects of the inhibition by catecholaminergic and opiatergic pathways of the electroencephalographic and vegetative pattern induced by corticotropin-releasing factor (CRF) in the rabbit].

The effects of catecholaminergic and opiatergic transmission inhibitors on CRF induced neurophysiological and autonomic patterns were tested. No interactions resulted between naloxone and CRF. Both DDC and MPT significantly reduced electrocortical and vegetative actions of CRF. Only the bradycardia was unmodified after premedications. Therefore our data confirmed the interactions between CRF and catecholaminergic pathways. The bradycardic effect seemed independent from the "stress-like" syndrome induced by CRF.

Animals↗

PubMedDate not supplied

Platelet composition and function in patients undergoing cardiopulmonary bypass for heart surgery.

BACKGROUND: Previous studies showed severe biochemical and functional damage to platelets in patients undergoing cardiopulmonary bypass for cardiac surgery, and suggested that this derived from the proteolytic action of plasmin on the platelet surface. METHODS: A double-blind study was carried out to compare platelet function and composition in patients randomized to receive the protease inhibitor aprotinin or placebo during reoperation for valvular prosthesis replacement or coronary artery bypass grafting. RESULTS: Flow cytometry with specific monoclonal antibodies and polyacrylamide gel electrophoresis did not show any significant proteolysis of platelet glycoprotein Ib and IIb-IIIa either in the placebo or the aprotinin group. Functional studies were consistent with these results, since ristocetin-induced platelet agglutination was unchanged and platelet aggregation and ATP release induced by collagen and ADP were only slightly reduced by cardiopulmonary bypass. These mild defects in platelet function were partially prevented by aprotinin infusion. CONCLUSIONS: On the basis of our data and those from literature, we suggest that platelets may be affected very little or severely damaged during cardiopulmonary bypass for cardiac surgery, probably depending on some aspects of the technical procedure which remain to be identified. Aprotinin infusion significantly protects platelets in the latter condition, while its role is obviously slight in the former.

Aprotinin↗