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Biomedical subjects

G Marano

Publications and source records attributed to G Marano.

17 recordsLinked to original sources
PubMed1994

Spinal cord stimulation and cerebral blood flow: an experimental study.

Spinal cord stimulation (SCS) affects peripheral, coronary and cerebral blood flow (CBF) in humans. In 1986 Meglio et al. [Appl Neurophysiol 1986;49:139-146] advocated a functional reversible sympathectomy as one of the mechanisms of SCS in man. An experimental animal model was developed to study SCS effects on CBF and to investigate the possible mechanisms. Twenty-one white New Zealand rabbits were anesthetized with Fluothane; spontaneous ventilation was permitted. A steady hemodynamic and metabolic state was maintained. A small cervical laminectomy was performed and an electrode (Medtronic Sigma 3483) was placed in the epidural space over the posterior spinal cord. Both common carotid arteries were exposed and external carotid arteries were ligated. In 3 animals, the cervical symapthetic trunk (CST) was exposed and wrapped with bipolar hook-stimulating electrodes. SCS was performed for 20 min with electrical square waves of 210 microseconds duration, 80 cycles/s, at 2/3 motor threshold intensity. CST stimulation was delivered for 1 min with the following parameters: 10 V, 10 cycles/s, 0.5 ms duration. CBF velocities of both internal carotid arteries were measured by using a CW Doppler (in all the animals) and electromagnetic flowmeter (in 2 animals), at rest, during sympathetic trunk stimulation, during SCS, during simultaneous SCS and CST stimulation. During SCS, an increase of CBF was detected in 11 rabbits (52.4%); a decrease was observed in two cases (9.5%). No change was detected in the remaining 8 animals (38%). CST stimulation induced a decrease of CBF in all animals. Electromagnetic flowmetry confirmed velocitometric findings in the 2 cases studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Serum selenium and precursors of cardiovascular risk factors in adolescents.

The aim of this study was to determine, in a population of Italian adolescents, the association of serum selenium levels with precursors of biochemical and anthropometric variables known as being among the major risk factors for cardiovascular diseases in the adult population. The following measurements were taken in a school sample of 627 adolescents (aged 12-13 years); serum selenium, total cholesterol, high density lipoprotein cholesterol, non-HDL cholesterol, height, weight, body mass index, systolic blood pressure and diastolic blood pressure. The serum selenium levels were slightly higher in males (83.1 +/- 10.1 micrograms/l) than in females (81.7 +/- 11.0 micrograms/l), but the difference was not statistically significant. Serum selenium was positively correlated with total cholesterol, diastolic blood pressure and HDL cholesterol in both sexes; moreover it was positively correlated with non-HDL cholesterol and negatively correlated with height in males only.

Adolescent↗
PubMed1991

Changes of serum selenium and serum cholesterol in children during sexual maturation.

We investigated the relationship of the degree of sexual maturation to serum selenium and serum cholesterol fractions in a population of Italian children. The following measurements were taken in 109 immature and 108 mature children of both sexes (aged 12 and 13a): serum selenium, total cholesterol, high density lipoprotein cholesterol, height, weight and degree of sexual maturation. Considerable differences were found in the two sexes at the end of maturation, with boys showing a significant decrease in serum selenium, HDL and non-HDL serum cholesterol levels. All variables, except height and weight, remained relatively constant in girls. These data indicate significant changes of serum selenium and serum cholesterol patterns during puberty, at least in boys, suggesting an involvement of sexual hormones in regulating serum selenium levels.

Adolescent↗
PubMed1990

Enhancement of pharmacologically induced bronchoconstriction by Ro 5-4864.

Pretreatment with Ro 5-4864 enhanced the bronchoconstrictor responses to histamine or carbachol in the anaesthetized artificially ventilated guinea pig. This suggests the involvement of a peripheral-type benzodiazepine receptor as also indicated by the lack of effect of clonazepam. PK 11195 did not antagonize the Ro 5-4864-induced enhancement, but itself enhanced the bronchoconstrictor responses to histamine or carbachol. The data indicate that Ro 5-4864 and PK 11195 behave as metactoid sensitizers of histamine or carbachol.

Animals↗
PubMed1990

Increased serum selenium levels in patients under corticosteroid treatment.

The normal serum and tissue levels of many micronutrients are remarkably affected by the therapeutical administration of several substances. In the present study, we have evaluated the modifications of serum selenium levels in different groups of patients under corticosteroid treatment. Such therapy was significantly associated with increased serum selenium levels, with a dose-dependent relationship in subjects treated with methylprednisolone. The reasons for this association are unknown. However, a reduced renal excretion of selenium, due to the mineralcorticoid activity of the corticosteroids, can be inferred.

Adult↗
PubMed1989

Age and sex specific reference serum selenium levels estimated for the Italian population.

The association between the concentration of selenium in serum and the risk of degenerative processes of the cardiovascular apparatus or of neoplastic disease remains still uncertain. An inaccurate selection of the study populations, and above all the lack of age, sex and area of residence specific reference values could have contributed to create confusion on the biological relevance of selenium in human diseases. In our present work the serum selenium levels for the Italian population have been studied, adopting standardized methods. The study population (4201 adult subjects and 1217 children) was derived from samples of populations previously enrolled in epidemiological preventive programs. The mean observed values for the various adult populations examined varied between 87 and 93 micrograms/l and resulted approximately 5 micrograms/l higher than the mean observed values in ten European countries. The mean observed values for the paediatric population (less than 15 years of age) were slightly lower (78-83 micrograms/l). A decreasing trend of the values with age, above 60 years, especially in males, has been observed. No significant difference has been observed for sex and geographic area of residence. A preliminary study of the variations of the serum selenium levels during certain diseases has shown a sharp reduction in children with phenylketonuria and undergoing dietary restrictions, in subject with active systemic Lupus erythematosus, and in certain neoplasias.

Adolescent↗
PubMed1986

[Clinico-developmental aspects of juvenile rheumatoid arthritis].

The first part of the report confirms the nosographic autonomy of juvenile rheumatoid arthritis (JRA) in the light of recent international discoveries. The second part identifies the particular clinical and evolutive aspects of the disease that are now universally accepted but still the subject of further research.

Arthritis, Juvenile↗
PubMed1986

[Psoriatic arthritis. Practical clinical and therapeutic aspects].

The first part of the paper describes the major clinical aspects of psoriatic arthritis. The second part examines the complex problem of therapy on the basis of personal experience in order to give the practical clinician guidance in the treatment and control of the condition.

Adult↗
PubMed1986

Serum proteins in human chorionic villi in the first trimester of pregnancy. An immunohistochemical study on normal tissue and tissue obtained from spontaneous abortions.

The presence of various proteins (mostly serum proteins) has been investigated in the chorionic villi of human placentas in the first term of gestation. The peroxidase-antiperoxidase method was employed. In normal chorionic tissue, i.e. obtained from therapeutic abortions, a positive staining for alpha 1-antitrypsin (A1AT), alpha 1-antichymotrypsin (A1AC), albumin and IgG was observed in syncytiotrophoblast but not in cytotrophoblast. Staining for other proteins, including fibrinogen, antithrombin III (AT III), lysozyme, ferritin, orosomucoid, carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), IgA, IgM and alpha 2-macroglobulin (A2M), was always negative in the trophoblast. Similar results were obtained in only a few cases of tissue obtained from spontaneous abortions which occurred during the first term of pregnancy. In the majority of spontaneous abortions a different immunohistochemical pattern was observed. The syncytiotrophoblast was immunonegative in the majority of cases, especially for albumin, whereas the cytotrophoblast showed a positive (although variable) reaction to A1AT, A1AC, albumin, IgG and orosomucoid antibodies. There is no evidence to indicate whether these differences are the cause or the secondary result of the spontaneous abortions, but we can hypothesize that they reflect an alteration of pinocytic functions of the trophoblast during the spontaneous abortions.

Abortion, Induced↗
PubMed1984

Silver-stained phenotyping of alpha 1-antitrypsin in dried blood and serum specimens.

In this technique for determining the electrophoretic phenotype of alpha 1-antitrypsin in dried blood or serum specimens, the adsorbed material is eluted with a concentrated solution of dithiothreitol, focused on polyacrylamide thin-layer gel, and made visible with silver stain. With this staining technique all normal and pathological alpha 1-antitrypsin phenotypes can be detected. The procedure is relatively simple, inexpensive, and suitable for use in large-scale screening for alpha 1-antitrypsin deficiency in selected populations.

Electrophoresis, Polyacrylamide Gel↗
PubMed1981

[MDA formation by platelets and plasmatic BTG levels in patients suffering from acute myocardial infarction (author's transl)].

Platelets are thought to be involved in the initiation and propagation of arterial and venous thrombi. A new formation of platelet thrombus in a coronary artery has been implicated in the genesis and extension of myocardial infarction. Experimental evidence suggests that platelet aggregates may be responsible for occlusion of small coronary arteries and subsequent ischemia. Whether the thrombotic component of myocardial infarction is primary or secondary in a given patient, platelet function alterations can influence many mechanisms - operating at the microenvironment level from which depends if the thrombotic lesion grows or sends platelet emboli to the smaller myocardial vessels. Although myocardial infarction is usually associated with arteriographic evidence of atherosclerotic coronary obstruction, examples of infarction in the absence of coronary artery disease have been reported. ARterial thrombosis, small vessel coronary disease and arterial spasm are several possibilities that have been described. Recently in some cases of myocardial infarction, coronary artery spasm has been demonstrated angiographically; thromboxanes, vasoconstrictive and platelet aggregating substances, are released by platelets; thromboxanes, vasoconstrictive and platelet aggregating substances, are released by platelets during myocardial ischemia as an increase of prostaglandin synthesis, like prostacyclin, is stimulated by ischemia and hypoxia. The local release of these substance may modify the myocardial cell viability and regional blood flow. The aim of the present study was to investigate some changes in platelet function in relation to the time stimulated with thrombin. The tests showed, in the first three days, an augmented release of BTG levels with a platelet "exhaustion", demonstrated by a reduced formation of MDA by platelets changing to a state of hyperactivity, with a maximal production of MDA in 10th-15th day.

Adult↗
PubMed1979

Transient ischemic attacks due to increased platelet aggregation and adhesiveness. Ultrastructural and functional correlation.

The authors report 22 cases of transient ischemic attacks (TIA's) manifested by amaurosis fugax or hemiparesis or paresthesia of less than 24 hours' duration. None of the patients demonstrated 1) evidence of atherosclerotic cerebral vascular disease on angiography, 2) evidence of intracranial lesion on brain scan, 3) cardiac source of emboli, 4) arteritis or collagen disease, or 5) history of migraine. The only abnormalities found to explain the TIA's were abnormally increased platelet adhesiveness and/or aggregation. All of these patients were followed from 1 to 5 years, and had repeated coagulation studies. Treatment with antiplatelet drugs showed an excellent clinical response with associated decrease in platelet adhesiveness and aggregation. Discontinuance of the antiplatelet drug resulted in a recurrence of the TIA's which coincided with an increase in aggregation and adhesiveness. In two cases the platelet morphology was studied by transmission and scanning electron microscopy. It appears that there is a specific group of patients with TIA's in whom the sole cause of the attack is an abnormality of platelet function. For these people there is a specific therapy and a method monitoring the treatment.

Adolescent↗