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Biomedical subjects

M Trabucchi

Publications and source records attributed to M Trabucchi.

At least 451 records · Page 25Linked to original sources

Effect of common carotid occlusion on beta-adrenergic receptor function in cerebral microvessels.

beta-adrenergic receptors were measured in cerebral microvessels of gerbils and rats after ligature of the right or left common carotid artery. The results indicate a decrease in the number of beta-adrenergic receptors in brain microvessels of both ipsilateral and contralateral hemispheres. This event may reflect altered patterns of the neuronal regulation of brain microvasculature and may be related to cerebrovascular alterations which are concomitant with ischemia. Furthermore, the results show that the decrease in beta-receptor density is more pronounced in the left hemisphere, independently on the side of carotid occlusion. This finding suggests that microvessel function in the left side of the brain is more vulnerable to hypoxia effects.

Animals↗

Time-related asymmetric changes of brain microvessel beta-adrenergic receptors in the two hemispheres after carotid occlusion.

The effect of short term and long term ischemia induced by right carotid occlusion was studied on beta-adrenergic receptor function in rat cerebral microvessels. The results show a different time-dependent responsiveness of the two hemispheres to ischemia, with a pronounced and more persistent decrease in the number of capillary beta-receptors in the left side of the brain. The data suggest the existence of asymmetries in the control of brain microvasculature which may mediate the different time-course of beta-receptor changes in response to ischemia.

Animals↗

Altered vessel signalling molecules in subjects with Downs syndrome.

Downs syndrome (DS) is the most frequent human chromosomal abnormality and is associated with mental retardation. Some evidence indicates that certain inflammatory molecules may be increased in DS. Proinflammatory and vasoactive molecules in the blood of non demented subjects with DS were measured in the present investigation. Plasma levels of interleukin-6 (IL-6), vascular endothelial growth factor (VEGF), monocyte chemoattractant protein-1 (MCP-1) and C reactive protein (CRP) were measured in child (2-14 years), adult (20-50 yrs) and elderly (> 60 yrs) DS subjects. Increased plasma levels of IL-6 and MCP-1 were present in DS. Plasma levels of VEGF were increased only in DS adults. Positive linear correlation between IL-6 and MCP-1 levels was present. However, no subclinical inflammation was apparent in DS, since neopterin and CRP levels were within the normal range. An altered regulation of these molecules might interfere with some processes involved in cognitive performances of DS subjects.

Adolescent↗

Clinical characteristics and risk factors of delirium in demented and not demented elderly medical inpatients.

OBJECTIVES: to evaluate the differences in clinical characteristics and risk factors of delirium in elderly medical inpatients according to the presence or not of dementia. DESIGN: cross-sectional, observational study. SETTING: acute medical care unit (ACU) of a general hospital. PARTICIPANTS: 330 patients aged 65 and older consecutively admitted on a 24-week period. MEASUREMENTS: Functional status, cognitive abilities, severity of acute illness (Acute Physiology, Age and Chronic Health Evaluation (APACHE II) score), Confusion Assessment Method (CAM), Delirium Rating Scale (DRS) and One Day Fluctuation Scale (ODFS). RESULTS: patients with delirium represent 19.1% of the sample, 41.0% of which had also dementia. Hyperactive form of delirium was 41.0%; hypoactive 11.0% and mixed 48.0%. In non demented patients, the delirious patients showed higher APACHE II score, more severe functional decline, poorer cognitive status respect to not delirious. In demented patients no differences were found in APACHE II score and cognitive status among delirious and not delirious subjects. In this group, functional decline (p = .012), acute infection (p = .007), psychotropic drugs use (p = .028) and severe hypoalbuminemia (p = .036) represented risk factors for the onset of delirium. Demented patients had higher perceptual disturbances (p = .040) and less severe delusions (p = .001), while total DRS score do not differs in the two groups. According to ODFS, delirium episode was more fluctuating in patients with dementia. CONCLUSION: clinical characteristics and risk factors of delirium are different in demented and not demented elderly inpatients. Patients with dementia are vulnerable to delirium at lower levels of medical acuity than non-demented patients.

APACHE↗

[The use of 1,1,1-trichloroethane (methylchloroform) in industrial operations: the neurotoxicity risk].

1,1,1-Trichloroethane (1,1,1-TE) is a widely used organic solvent which is thought to be relatively safe. The present review is mainly focused on the neurotoxic effects of 1,1,1-TE. Concentrations above 350 ppm are considered capable of negatively conditioning the performance of the exposed person, in particular reaction time and manual abilities. Peripheral neuropathies have also been described. More recently the potential neurotoxicity of 1,1,1-TE has been underscored by animal studies investigating the effects of this substance in neurobehavioral tests and on neurochemical parameters. 1,1,1-TE alters the motor activity in small laboratory rodents. In fixed interval responding in mice, the effects of 1,1,1-TE are qualitatively similar to those of other volatile (ethanol) and non volatile (benzodiazepines and barbiturates) CNS depressants. In addition, in drug discrimination procedures 1,1,1-TE shares discriminative stimulus properties with barbiturates, toluene, halotane, and oxazepam indicating that this solvent has behavioral effects in common with central nervous system depressant drugs. From a neurochemical point of view long-term exposure to 1,1,1-TE induces astrogliosis in the cerebral cortex of gerbils as indicated by an increased concentration of glial fibrillary acidic protein. In addition low dose inhalation of 1,1,1-TE for 3 months decreases DNA concentrations in several brain regions of the gerbil. 1,1,1-TE affects also brain concentrations of cAMP and cGMP as well as calcium ion control, possibly through an action on voltage-dependent calcium channels. It has been also suggested that intermediate metabolites of 1,1,1-TE may give origin to condensation products with dopamine, ultimately impairing dopaminergic transmission. Some of the neurochemical effects of 1,1,1-TE are shared by other chlorinated organic solvents as well as by CNS depressants. The literature analyzed indicates that 1,1,1-TE may exert significant neurotoxic effects suggesting that more caution in its use is needed and that attention should be paid to the possibility of an additive effect of 1,1,1-TE and CNS depressants (ethanol, barbiturates, benzodiazepines and other volatile solvents) giving origin to severe neurotoxicity.

Animals↗

Plasma prolactin concentrations in lead exposed workers.

Plasma Prolactin (Prl) Zinc protoporphyrin (Zpp) and blood lead concentrations (PbB) were measured in 76 exposed male workers. All of them were employed in small (not more than 30 persons) pewter factories and were randomly selected from those regularly controlled by the National Health Service, Occupational Health Unit of Brescia (USSL 41). Although all plasma Prl values were within the normal range, the mean value of the subgroup having Zpp and PbB higher than 40 micrograms/dl was significantly higher (+47%) than that observed in the group of workers having Zpp and PbB less than 40 micrograms/dl. The data indicate the possibility of a lead-induced Prl secretion dysfunction, probably mediated by a decrease in dopaminergic inhibitory control.

Adult↗

[Toxicologic hazards at the endocrine level of heavy metals].

The effects of heavy metals (in particular Pb, Cd, Cr, Mn and Hg) on pituitary, thyroid, adrenal gland, pancreas and gonads are reviewed. The effect of these metals on the CNS centers regulating endocrine function is emphasized. On this time, the reviewed data stress the importance of studying the mechanisms of preclinical damage and the biological markers of it.

Adrenal Gland Diseases↗

Acute ethanol administration during pregnancy: effects on central dopaminergic transmission in rat offspring.

The present study investigated the effect of ethanol ingestion during pregnancy on central dopaminergic function in the nervous system of the offspring. Marked changes in striatum of both binding of 3H-spiperone and the concentrations of DOPAC were found in offspring particularly when an acute dose of ethanol was administered to pregnant dams on the fourth day of pregnancy, whereas changes in the binding of 3H-5HT in cortex were not seen. Interestingly, administration of ethanol from the fourth day to the end of gestation, or only on the 13th day, caused different effects or no effect, respectively. These data suggest that alterations of dopaminergic function may be markers of teratogenic effects of ethanol, and may be related to some of the clinical symptoms appearing in children affected by Fetal Alcohol Syndrome.

3,4-Dihydroxyphenylacetic Acid↗