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Biomedical subjects

G Marano

Publications and source records attributed to G Marano.

At least 19 recordsLinked to original sources
PubMed2006

The Body Uneasiness Test (BUT): development and validation of a new body image assessment scale.

OBJECTIVE: To investigate the psychometric properties of the Body Uneasiness Test (BUT), a 71-item self-report questionnaire that consists of two parts: BUT*A which measures weight phobia, body image concerns, avoidance, compulsive self-monitoring, detachment and estrangement feelings towards one's own body (depersonalization); and BUT*B which looks at specific worries about particular body parts or functions. METHODS: We recruited a clinical sample of 531 subjects (491 females) suffering from eating disorders and a general population sample of 3273 subjects (2016 females) with BMI <25 and Eating Attitudes Test-26 scores under the cut-off 20. RESULTS: The exploratory and confirmatory analyses confirmed a structural five-factor model for BUT*A and an eight-factor model for BUT*B. Internal consistency was satisfactory. The test-retest correlation coefficients were highly significant. Concurrent validity with other tests (Eating Disorder Inventory, EDI-2; Eating Attitudes Test, EAT-26; Symptom Check List, SCL-90R and Coopersmith Self-Esteem Inventory, SEI) was evaluated. Normative values for BUT scores in non-clinical samples of normal-weight non eating disordered subjects, from adolescence to old age, males and females, were calculated. The differences between males and females were highly significant, above all in the 18-39-age range. As for the comparison between women with eating disorders and controls, the results demonstrated a good predictive validity for anorexia nervosa and bulimia nervosa. CONCLUSIONS: The BUT is psychometrically sound. It can be a valuable tool for the screening and the clinical assessment of abnormal body image attitudes and eating disorders.

Adolescent↗
PubMed2005

Acaricidal properties of the essential oil of Melaleuca alternifolia Cheel (tea tree oil) against nymphs of Ixodes ricinus.

The aim of the study was to examine the acaricidal effect of essential oil of Melaleuca alternifolia (tea tree oil, TTO) at different doses (4, 6, 8 and 10 microl) and for different exposure times (30, 60, 90 and 120 min) on nymphs of Ixodes ricinus. A dose of 8 microl TTO was lethal for more than 70% of ticks when inhaled and this effect was enhanced when the dose was increased to 10 microl (> 80%). The effect was correlated with the duration of exposure of ticks to TTO, with a significant effect being observed after 90 min exposure. The findings show that TTO has acaricidal properties and could be extremely useful in controlling ticks that are efficient vectors of pathogens.

Animals↗
PubMed2005

Focal nodular hyperplasia after busulfan treatment.

The case of a 48-year-old woman in whom focal nodular hyperplasia of the liver developed after busulfan therapy was administered for essential thrombocytosis is described. Focal nodular hyperplasia is a reactive disorder related to a circulation disorder. The close temporal relation between the haematological disease, busulfan treatment and the appearance of hyperplastic diseases of the liver in our patient supports the possibility that the association of the events might not be casual.

Busulfan↗
PubMed2005

Gingival overgrowth with calcium-channel blockers. Treatment options.

Gingival overgrowth induced by calcium channel blockers can cause significant disfigurement and functional difficulty since it interferes with eating and speech, prevents effective plaque control, and disturbs occlusal relationships. It occurs more in young and male patients. The aim of this paper is to study the physiopathology of gingival overgrowth induced by calcium channel blockers and propose different choices of treatment.

Algorithms↗
PubMed1999

Endothelin and mechanical properties of the carotid artery in Wistar-Kyoto and spontaneously hypertensive rats.

The aim of this study is to evaluate the role of endothelin in the control of the static mechanical properties of in vitro carotid arteries from 14-week-old Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). An in vitro preparation in which the artery was allowed to longitudinally elongate similarly to the in situ carotid artery was employed. The diameter of in vitro carotid arteries subjected to static pressures (from 25 to 200 mmHg in 25 mmHg steps) was determined by videomicroscopy and computer-assisted image analysis, the cross-sectional compliance- and distensibility-pressure curves being then derived. The role of endothelin was assessed by incubating carotid arteries with the selective ETA and ETB endothelin receptor antagonists BQ123 and BQ788, respectively. These effects were compared with those observed under control conditions, as well as with those following complete abolition of vascular smooth muscle tone by potassium cyanide (KCN). Carotid diameter was significantly larger, and compliance and distensibility significantly smaller, in SHR compared to WKY rats. Local incubation with BQ123 was associated with significant dilations as well as significant increases in cross-sectional compliance and distensibility in both strains. This was even more pronounced with KCN, while BQ788 had no effect. The results of the present study suggest that: (i) endothelin exerts a tonic stiffening effect on the in vitro common carotid artery; (ii) this effect is mediated via the ETA endothelin receptor, and (iii) the stiffening effect of endothelin is exerted to a similar extent in the carotid arteries of normotensive WKY and SHR rats.

Animals↗
PubMed1999

Sympathectomy inhibits the vasoactive effects of nicotine in conscious rats.

OBJECTIVE: The mechanisms underlying the pressor response to nicotine are incompletely understood. Although sympatho-adrenergic activation plays a major role, the relative contribution of adrenal vs. neurally released catecholamines and the possible role of non-adrenergic factors (e.g. vasopressin release) is not established. METHODS: We examined the cardiovascular responses to graded i.v. injections of nicotine (1 to 100 micrograms kg-1) in conscious Wistar-Kyoto rats under control conditions and (i) after chemical sympathectomy by 6-hydroxydopamine, which destroys sympathetic endings but spares the adrenal medulla; (ii) after an alpha-adrenergic blockade by phenoxybenzamine; (iii) after a V1 vasopressin receptor blockade by a specific antagonist. RESULTS: In control rats, nicotine caused a dose-dependent tachycardiac and pressor response. Both responses were abolished by sympathectomy, whereas the alpha-blockade left the tachycardiac response unaffected but inhibited the pressor response: the V1 vasopressin receptor blockade had no effect on either the tachycardiac or pressor response. CONCLUSIONS: We conclude that in the conscious rat; (1) the pressor response to nicotine mainly depends on peripheral alpha-adrenergically-mediated vasoconstriction; (2) the vasomotor effect is caused by neural rather than adrenomedullary catecholamine release; (3) the nicotine-induced increase in heart rate (and presumably cardiac output) is per se unable to raise blood pressure, and (4) the nicotine-induced release of vasopressin plays no significant role in the pressor response.

Adrenergic alpha-Antagonists↗
PubMed1999

Protection by shear stress from collar-induced intimal thickening: role of nitric oxide.

Nitric oxide (NO) has potent relaxant and antiproliferative effects on vascular smooth muscle cells, which may represent an important antiatherosclerotic mechanism. Since one of the major stimuli for NO release is flow-related shear stress, we have investigated (1) the effect of increased shear stress on neointimal formation induced in the rabbit carotid artery by enclosing the vessel in a nonconstrictive silicone soft collar and (2) the role of NO in the antiproliferative effect of increased shear stress. Forty-three New Zealand White rabbits were used. High shear stress in the left common carotid artery (CCA) was induced by ligature of the contralateral right internal carotid artery; intimal thickening was produced by the positioning a nonconstrictive silicone soft collar around the left CCA. To evaluate the role of NO, N(G)-nitro-L-arginine methyl ester (L-NAME) was orally administered at a subpressor dose. In all rabbits, arterial blood pressure, heart rate, arterial diameters, and blood flow velocities of both CCAs were determined at days 0, 3, 7, and 14. At the end of the study, all rabbits were euthanized, and histological analyses were performed on both CCAs of each animal. The presence of the collar was associated with a marked degree of intimal hyperplasia (intimal/medial area ratio 29+/-3.0% in collared arteries compared with 3+/-0.7% in sham control [noncollared] arteries, P<0.001). The increase in blood flow almost completely inhibited neointimal formation and induced an increase in arterial diameter of approximately 30%. The effects of increased blood flow were reversed by the administration of L-NAME. In conclusion, we demonstrate that in collar-induced intimal thickening, a chronic increase in shear stress (1) almost completely inhibits intimal thickening, and (2) this protective effect is mediated by NO production.

Animals↗
PubMed1998

ET(A)/ET(B) receptor antagonist bosentan inhibits neointimal development in collared carotid arteries of rabbits.

The contribution of endothelin to the genesis of neointimal development in collared rabbit carotid arteries, a widely accepted model of atherosclerosis, was investigated. Three sets of rabbits were studied. In the first group, a non-occlusive, biologically inert silastic collar was positioned around the right carotid artery of the rabbit. In another group, the application of the collar was accompanied by endothelial denudation via a Fogarty arterial balloon catheter, while the third group of animals underwent only endothelial denudation. After two weeks, intimal hyperplasia of a similar degree was observed in all groups. The administration of the nonselective ET(A)/ET(B) receptor antagonist Bosentan, significantly reduced both the neointimal area and the intima/media area ratio in all groups. However, the beneficial effects of Bosentan were less pronounced in balloon injured vessels than in collared ones. The results of the present study indicate that i) endothelin has a key role in the development of intimal hyperplasia following arterial collaring, ii) the contribution of endothelin to intimal hyperplasia is greater in collared arteries that in balloon injured ones, and iii) the nonselective ET(A)/ET(B) receptor antagonists are potential tools for the prevention of intimal hyperplasia.

Animals↗
PubMed1997

Effects of angiotensin II on myocardial contractility during short-term pressor responses to angiotensin II.

BACKGROUND: Cardiac angiotensin AT1 receptors have been found in several animal species. In-vitro studies performed on cardiac preparations have shown that angiotensin II (ANG II) exerts a positive inotropic effect; however, in-vivo results have allowed no definitive conclusion to be drawn. The reasons behind these controversial results remain unknown, and could originate both from different experimental conditions and from the techniques used to assess myocardial contractility. OBJECTIVE: To investigate, by means of echocardiographic measurements, whether ANG II, administered to intact and to sinoaortic denervated isoflurane-anesthetized rabbits, was able to directly increase myocardial contractility. METHODS: The effect of ANG II on cardiac contractility was assessed with the use of simultaneous pressure measurements and Doppler-echocardiographic recordings. Specifically, we used both the relationship between the left ventricular end-systolic wall stress and the velocity of heart-rate-corrected circumferential fiber shortening (VCFC) and the maximum rate of rise of the ventricular pressure as indices of changes in myocardial contractility. Cardiac contractility was evaluated both in intact and in chronically sinoaortic denervated isoflurane-anesthetized rabbits under basal conditions and after ANG II infusion (50 ng/kg per min). RESULTS: After ANG II infusion, increases in mean arterial blood pressure, left ventricular end-diastolic diameter and pressure were observed both in intact and in chronically sinoaortic denervated rabbits. The left ventricular end-systolic wall stress (a function of the mean arterial pressure and chamber size) and the maximum rate of rise of the ventricular pressure rose markedly in rabbits of both groups, whereas the VCFC decreased significantly. However, when compared the VCFC under ANG II infusion with that calculated at the same level of left ventricular afterload under basal conditions, we observed that ANG II infusion induced no significant change in VCFC either in intact of in chronically sinoaortic denervated rabbits. CONCLUSION: Our results indicate that administration of ANG II to isoflurane-anesthetized rabbits induces a marked rise in ventricular pre- and after-loads and exerts no significant effect on the cardiac contractility. In light of this, it is reasonable to assume that the short-term increase in arterial blood pressure can be ascribed mainly to the increase in peripheral arterial resistance.

Angiotensin II↗
PubMed1997

Effects of isoflurane versus halothane on myocardial contractility in rabbits: assessment with transthoracic two-dimensional echocardiography.

The effects of isoflurane versus halothane on cardiac contractility were evaluated by two-dimensional (2D) transthoracic echocardiography in rabbits. The relationship between the left ventricular end-systolic wall stress (LVESWS) and the velocity of heart rate corrected circumferential fibre shortening (Vcfc) was used. Arterial blood pressure, heart rate, left ventricular pressure and transthoracic 2D echocardiogrphic data were determined at 1 MAC (minimum alveolar concentration) of halothane or isoflurane, both with 50% nitrous oxide. Drug-induced changes in pre- and afterload were performed in all study animals to assess the left ventricular contractile response over a wide range. LVESWS and Vcfc were calculated on videotape recorded M-mode tracings. Mean heart rate and arterial blood pressure were not significantly different between the two groups. Myocardial contractility under isoflurane/nitrous oxide anaesthesia was significantly higher than under halothane/nitrous oxide anaesthesia at 1 MAC. The results of the present study confirm data obtained from humans and other animal species and suggest that, in rabbits, myocardial contractility is best preserved by inhalation of isoflurane. Isoflurane should therefore be preferred over halothane, especially in cases of prolonged anaesthetic procedures.

Anesthetics, Inhalation↗
PubMed1996

Effects of isoflurane on cardiovascular system and sympathovagal balance in New Zealand white rabbits.

We investigated the effects of isoflurane on the rabbit cardiovascular system at several end-tidal concentrations. Furthermore, because isoflurane has been reported to produce tachycardia while reducing sympathetic nervous activity and baroreflex function, we evaluated whether the chronotropic effects of isoflurane could be due to a vagal withdrawal. ECG, mean arterial pressure (MAP), and heart rate (HR) were obtained in rabbits the conscious, unsedated state and during isoflurane anesthesia by telemetric device. Measurements of pH, oxygen, carbon dioxide, plasma catecholamines, baroreflex sensitivity, and spectral analysis of HR variability were made in nonanesthetized and anesthetized animals. Isoflurane caused an increase in HR at 0.5, 1, and 1.5 minimum alveolar concentration (MAC) and a decrease in systolic and diastolic blood pressure (SBP, DBP) and MAP at 1 and 1.5 MAC. Biochemical analysis showed that isoflurane-mediated cardiovascular effects were not accompanied by any significant changes in plasma norepinephrine (NE) and epinephrine (Epi) levels. Neither were any significant differences in plasma catecholamine levels noted between anesthetized and awake animals. The analysis of spectral components of HR variability and baroreflex function indicated that isoflurane induced a marked reduction in the low- and high-frequency spectral power of HR variability and in baroreflex sensitivity. Tachycardia under isoflurane was suppressed dose dependently by the administration of clonidine or atenolol and was not influenced by bilateral vagotomy. Collectively, our results indicate that cardiovascular effects induced by isoflurane in smaller animals such as rabbits are similar to those observed in humans and other animal species. We showed that isoflurane-induced tachycardia is mainly the result of vagal withdrawal rather than a baroreflex response, even though a marginal role of baroreflex in heart response to higher concentrations of isoflurane cannot be excluded.

Anesthetics, Inhalation↗
PubMed1994

Postjunctional regulation by angiotensin II of alpha 1-adrenoceptor-mediated pressor responses in the rat.

The effects of angiotensin II on the vasopressor responses to the selective alpha 1-adrenoceptor agonist, phenylephrine, in intact and sympathectomized rats were investigated. Infusion of angiotensin II at subpressor doses significantly enhanced the pressor effects of phenylephrine in intact rats. We also found that in the chemically sympathectomized rat, where prejunctional sympathetic function is impaired, the effects of angiotensin II infusion on the pressor effects of phenylephrine were similar to those obtained in intact rats. Furthermore, pretreatment with valsartan ((S)-N-valeryl-N-([2'-(1H-tetrazol-5-yl)biphenyl-4-yl]-methyl)-val ine), a new selective angiotensin AT1 receptor antagonist, antagonized the effects of angiotensin II on phenylephrine-mediated pressor responses, whereas the administration of the selective angiotensin AT2 receptor antagonist, PD 123319 (1-[[4-(dimethylamino)-3-methylphenyl]-methyl]-5-(diphenylacetyl)- 4,5,6,7-tetrahydro-1H-imidazo[4,5-c]-pyridine-6-carboxylic acid, ditriflouroacetate, monohydrate), injected in bolus doses of 100 micrograms/kg, did not antagonize the enhancing effect of angiotensin II. Collectively, these data suggest that angiotensin II modulates the response to phenylephrine primarily at a postjunctional level through the activation of angiotensin AT1 receptors and that the suggested prejunctional facilitation mediated by angiotensin receptors is quantitatively much less important in the intact animal.

Angiotensin II↗
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↗
PubMed1994

Airflow measurements in small animals.

Monitoring respiratory airflow is extremely important in pharmacological studies of the respiratory system. However, in mechanically ventilated small animals (e.g. rats and guinea pigs) the use of a commercial pneumotachometer, attached directly to the tracheal cannula, substantially increases the equipment dead space (the volume shared by inspired and expired gases). Since apparatus dead space must be added to the tidal volume (determined on the basis of ventilatory rate and animal body weight) necessary to meet the respiratory needs of the animal, the resulting stroke volume is greatly increased, specially in very small animals. This results in an increase in intrathoracic pressure which is potentially associated with a decrease in venous return, cardiac output, and arterial pressure. The author investigated the possibility of avoiding the potential problems of the added instrumental dead space by software-summing the separate flows measured on the inflation and deflation limbs of the breathing circuit. This study shows that the summation of the flow signals obtained from separate pneumotachometers on the inspiratory and expiratory arms of the breathing circuit is not dissimilar to the total flow as measured by a pneumotachometer directly attached to the tracheal cannula and that the method here described can be an advantageous alternative to the employment of a single pneumotachometer.

Airway Resistance↗
PubMed1993

Reduced antinociceptive response to beta-endorphin in adult mice after chronic neonatal handling.

Male CD-1 mice were daily exposed to handling stress from second to the nineteenth days of life. Eleven and 16 days after the interruption of stress, handled (HA) and control nonhandled (UHA) animals were tested to measure the baseline threshold for the perception of thermal nociceptive stimulation by the tail-flick test (TFT) and to assess the presence of the Straub tail response (STR). On day 50 of life, the antinociceptive response induced by intracerebroventricular B-endorphin (BE) was also studied. The results indicated that animals chronically handled during the neonatal period, at the age of 5 weeks, showed a strong activation of the endogenous opioid system as demonstrated by the higher response latency to the TFT, as well as by the presence of a marked STR. Then, at the age of 50 days, there was no longer a difference in the TFT latencies between UHA and HA groups, but a significantly reduced response to the antinociceptive effect of BE was present in HA mice.

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↗