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Biomedical subjects

M Ferrante

Publications and source records attributed to M Ferrante.

31 records · Page 2Linked to original sources
PubMed1981

Subtypes of beta-adrenergic receptors in rat cerebral microvessels.

The 125I-labeled iodohydroxybenzylpindolol (IHYP) binding to beta-receptors on brain micro-vessels is inhibited by isoproterenol, epinephrine and norepinephrine, with Ki values of 2 X 10(-7) M, 2.5 X 10(-6) M and 1.2 X 10(-5) M, respectively. A modified Scatchard analysis of the inhibitory effects of practolol, metroprolol and zinterol on IHYP binding has shown that the proportion of beta 2-receptors in our preparation is about 80% of the total beta-adrenergic receptor population. Our data indicate that the beta-adrenergic receptors located on cerebral microvessels are of both beta 1 and beta 2 types, with a predominance of the beta 2 type.

Animals↗
PubMedDate not supplied

Reporting, filing, and retrieval of coronary angiographic findings: a new personal computer-based system.

A software system for semiautomatic reporting and automatic filing of coronary angiographies has been developed and is suitable for an IBM Personal Computer (PC) with graphic tablet and printer. Coronary angiographic findings referring to the native anatomy, pathology, and post-surgical status can be easily recorded. The data is automatically coded and filed according to category of information. This system can analyze previously filed data and perform searches under one or more angiographic findings. This allows for a comparison of different series of patients.

Algorithms↗
PubMedDate not supplied

Dendritic Ih selectively blocks temporal summation of unsynchronized distal inputs in CA1 pyramidal neurons.

The active dendritic conductances shape the input-output properties of many principal neurons in different brain regions, and the various ways in which they regulate neuronal excitability need to be investigated to better understand their functional consequences. Using a realistic model of a hippocampal CA1 pyramidal neuron, we show a major role for the hyperpolarization-activated current, Ih, in regulating the spike probability of a neuron when independent synaptic inputs are activated with different degrees of synchronization and at different distances from the soma. The results allowed us to make the experimentally testable prediction that the Ih in these neurons is needed to reduce neuronal excitability selectively for distal unsynchronized, but not for synchronized, inputs.

Animals↗
PubMedDate not supplied

Decreased lipid fluidity of the erythrocyte membrane in dogs with leishmaniasis-associated anaemia.

In both man and the dog, anaemia resulting from natural leishmaniasis is often severe and mainly associated with a shortened life span of erythrocytes. Lipid fluidity of erythrocyte membranes from 17 dogs with anaemia caused by visceral leishmaniasis was investigated by means of fluorescence polarization. Results were compared with those from three groups of control animals (10 healthy dogs, seven dogs with visceral leishmaniasis but no anaemia, and 10 dogs with anaemia unrelated to leishmaniasis). Fluorescence polarization values recorded for animals with leishmaniasis-associated anaemia were elevated-indicating reduced erythrocyte membrane fluidity-and significantly higher than in the control groups. Mechanical sequestration by the spleen due to increased cell rigidity, or alterations in receptor/ligand erythrocyte cytoadherence mechanisms, or both, may result from decreased membrane fluidity and hence contribute to the anaemia of Leishmania -infected dogs.

Anemia↗
PubMedDate not supplied

Cyclic GMP phosphodiesterase activity role in normal and inflamed human dental pulp.

Cyclic GMP phosphodiesterase (cGMP PDE) plays an important role in pulp tissues. High levels of cGMP PDE are found in dental pulp cells. In the present study cGMP PDE activity was analyzed in normal healthy human dental pulps, in reversible pulpitis and in irreversible pulpitis. Enzymatic cGMP PDE control values for normal healthy pulps were 4.74+/-0.32 nmol/mg of proteins. In reversible pulpitis the cGMP PDE activity increased almost 3 times. In irreversible pulpitis specimens the values increased 4.5 times compared with the normal healthy pulps activity. The differences between the groups (control vs. reversible pulpitis and vs. irreversible pulpitis) were statistically significant. These results point to a role of cGMP PDE in the initial pulp response after injury.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMedDate not supplied

Lymphocyte subpopulations in pediatric age. Definition of reference values by flow cytometry.

In the present paper we have analyzed the age-related changes in the distribution and numbers per cubic millimeter of the circulating lymphocyte subpopulations. Lymphocyte subsets have been examined by monoclonal antibodies specific for surface antigens (namely CD2, CD3, CD4, CD8, CD16, CD20 and CD57) and flow cytometry in lysed peripheral blood of normal neonates (1-3 days old), 1-6 month, 7-12 month, 1-2 year old babies and 3-5 year, 6-10 year old children and young people up to 17 years of age. The results confirm the lymphocytosis at birth and at later stages of life and indicate that major changes in the distribution of lymphocyte subsets occur during the first two years of life; namely we have observed sharp increase of circulating B lymphocytes and prevalence of CD4+ T lymphocytes with high CD4/CD8 ratios in babies up to two years of age, compared to the values observed in normal adults. Very few CD8+ CD57+ lymphocytes were present at birth; cells bearing this phenotype appeared later in life. Lymphocytes expressing the CD16 antigen were already present in newborns. The authors discuss the functional meanings of the age-related changes observed in the distribution and in the numbers of circulating lymphocytes. The presented data represent valuable normal ranges of lymphocyte subsets to compare with values observed in sick babies or children.

Adolescent↗
PubMedDate not supplied

Direct measurement of pulmonary and systemic flow during assisted circulation.

During biventricular assistance as a bridge to cardiac transplantation, the flow data provided by the pumping systems were compared with flow data obtained with the Fick method. There was a difference between the data sets only in the first 20 hr of observation, with the Fick method giving higher values. During the same period, analysis of the arterial and pulmonary pressure traces showed pulsatile activity to be related with the electrocardiogram's T waves. In the long run, the flow data provided by both methods were no different and the T wave-related pulsatile activity disappeared. The authors concluded that the Fick method represents a useful tool when measuring total flow during biventricular support.

Assisted Circulation↗
PubMedDate not supplied

[Hemodynamic effects of propofol in patients undergoing pulmonary excision and in patients undergoing closed heart mitral valve surgery].

The effects of propofol on cardiovascular dynamics were studied, by means of SO2 Swan-Ganz catheter, in 12 patients scheduled for elective pulmonary resection and in 10 patients undergoing closed heart mitral valve commissurotomy. Myocardial contractility was also investigated in 10 patients (5 pulmonary and 5 mitral valve patients) by means of transthoracic echocardiography. The patients were premedicated with morphine (0.1 mg/kg i.m.), scopolamine (0.005 mg/kg i.m.) and diazepam (0.1 mg/kg p.o.). Anaesthesia was induced with propofol (2 mg/kg i.v.) and fentanyl (0.005 mg/kg i.v.) and maintained with propofol (6 mg/kg/h) plus fentanyl (0.005 mg/kg/h) infusion. Muscle relaxation was assured by pancuronium bromide (0.1 mg/kg). Ventilation (O2-N2O 50%) was controlled to maintain ETCO2 between 30 and 40 mmHg. All the patients undergoing pulmonary resection were intubated with double lumen endotracheal tube. Measurements were performed with the patients awake, after induction, during steady state anaesthesia, before and after thoracotomy. Propofol together with fentanyl significantly decreased arterial pressure (more than 35%) and cardiac index (more than 40%) in both groups of patients; heart rate showed no significant changes even after intubation. Right atrial pressure didn't change meanwhile wedge pressure showed a reduction, with statistical significance only in pulmonary patients. Total systemic resistances didn't show any variation in both groups of patients. The echocardiographic data revealed an important impairment of myocardial contractility after bolus of propofol, mainly in cardiac patients, as evidenced by decrease of ejection fraction values (20%) and by increase of left ventricle end systolic volume index (10%) from baseline. SVO2 and DO2/VO2 ratio values were stable, according with deep anaesthesia level and adequate metabolic balance. In pulmonary patients, during one lung ventilation, the intrapulmonary shunt values did not differed either during or without propofol infusion, thus suggesting that propofol doesn't interfere with pulmonary hypoxic vasoconstrictor response. In conclusion an aware use of propofol and a careful haemodynamic monitoring would be advisable primarily in patients with a well known or supposed cardiovascular disease.

Adult↗