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Biomedical subjects

G Tedeschi

Publications and source records attributed to G Tedeschi.

At least 127 records · Page 7Linked to original sources

Effect of amphetamine on saccadic and smooth pursuit eye movements.

Healthy volunteers received single oral or intravenous doses of d-amphetamine sulphate (15 mg) and placebo in a double blind randomized design. Peak velocity of horizontal saccadic eye movements, saccade duration, saccade reaction time and smooth pursuit velocity were measured at intervals up to 1 h (IV) and 6 h (oral) after drug administration. Amphetamine produced no significant effect on saccadic and smooth-pursuit eye movements after oral administration. However, intravenous amphetamine abolished the effect of fatigue on saccadic movements and significantly (P less than 0.01) shortened saccadic reaction time.

Administration, Oral↗

Rate of entrance of benzodiazepines into the brain determined by eye movement recording.

1 Peak saccadic velocity of horizontal eye movements, saccade duration at 30 degrees of amplitude and saccade reaction time were measured in six drug free male subjects. 2 In two separate experiments, intravenous doses of diazepam (5 mg), lorazepam (2 mg), chlordiazepoxide (25 mg) and placebo were given, and eye movement recordings were made before and at frequent intervals after drug administration. 3 All the benzodiazepines produced a significant impairment of peak saccadic velocity and saccade duration. Only lorazepam significantly affected saccade reaction time. 4 Time to achieve maximum effect was 10 min after diazepam, 29 min after lorazepam and 42 min after chlordiazepoxide.

Adult↗

Prolactin secretion in man: a useful tool to evaluate the activity of drugs on central 5-hydroxytryptaminergic neurones. Studies with fenfluramine.

Acute oral administration of various doses of fenfluramine, a 5-HT releaser, induced a dose-related increase of PRL secretion in nine healthy volunteers. Fenfluramine reached the maximum effect on PRL secretion at 4 h after its administration. This effect was already significant at 2 h and lasted till 8 h. Metergoline, a 5-HT receptor blocker, when administered alone, decreased serum PRL levels in six healthy subjects. The pretreatment with this drug significantly antagonized the PRL-releasing action of fenfluramine (60 mg) suggesting that the effect of fenfluramine on PRL release may be mediated through a 5-HT mechanism in the brain. These findings suggest the possibility that serum PRL levels in humans may represent a useful tool to evaluate, in vivo, the activity of drugs possessing putative 5-hydroxytryptaminergic properties.

Adult↗

[Supratentorial arachnoidal cysts].

The AA., after having examined the various hypothesis reported in literature about the etiopathogenesis and the contrasting anatomical and pathological data concerning the arachnoid supratentorial cysts, point out the remarkable frequency of they malformative and above-all post-traumatic genesis. On the formation mechanism of this last type, they agree upon the supposition expressed by Taveras and Ransohoff in 1953. The AA., therefore, after having analysed the principal morphological and topographical aspects, pay attention to the present diagnostic possibilities, above all in radiological range, where the TAC represents, by this time, the examination of election compared with traditional assurances with means of contrast. It follows the analysis of the personal casuistry, consisting in 6 arachnoid supratentorial cysts, two of which clearly post-traumatic and two, very probably, of malformative genesis (for the coexistence of data in favour of both suppositions). The AA. draw these conclusions: the CT Scan is the only diagnostic means which permits an exact pre-operating diagnosis on the nature of the lesion; the surgical and, above all, anatomo-pathological reports assume an essential rule for an exact etiopathogenetic interpretation of the lesion examined.

Adolescent↗

A case of pan-medullary astrocytoma in a child.

The authors report a case of a Grade 2 astrocytoma with pan-medullary extension, from C1 to L2, in a little girl aged 12. It was successfully operated on. The clinical picture showed an initial acute paraplegia which suddenly turned into tetraplegia with respiratory insufficiency and second degree coma. Besides the rarity of the case, some atypical aspects are pointed out, such as the patient's youth and the partially aggressive character of the neoplasm. The surgical implications of such pan-medullary tumours are discussed, the authors emphasize the aspects that in their opinion indicate exploratory surgery and, when possible, total removal of the tumours.

Acute Disease↗

Intracerebral haemorrhage: an attempt at statistical assessment for operability.

A series of 88 patients, who underwent operation for intracranial haemorrhage, is reported. The outcomes are assessed in order to evaluate the operability in relation to the patient's age, the type of onset, the site of haemorrhage, the conscious level, the interval between accident and operation, cardiovascular disease and the dysmetabolic values. A numerical value has been assigned to each factor considered; than the correspondence between these values and the importance of each factor in relation to the clinical state has been analysed. The authors finally point out that their study, although it has a merely indicative significance, agrees sufficiently with the clinical results, as to give a useful pattern for a statistical approach to the question of intracerebral haemorrhage, offering in the meantime hopeful aids to diagnosis.

Age Factors↗

Effect of midbrain raphe lesion or 5,7-dihydroxytryptamine treatment on the prolactin-releasing action of quipazine and D-fenfluramine in rats.

The role of brain serotonin in regulating prolactin (PRL) secretion has been investigated by studying the effect of quipazine and D-fenfluramine, two serotonin-like drugs, on plasma PRL levels under various experimental conditions. Quipazine (5, 10 and 20 mg/kg i.p.) and D-fenfluramine (5, 7.5 and 10 mg/kg i.p.) induced dose-related increases in plasma PRL levels in male rats. Intraventricular injection of 5,7-dihydroxytryptamine (5,7-DHT) or electrolytic lesion of the nucleus raphe medianus (MR), which caused a marked and selective depletion of hypothalamic serotonin levels, significantly reduced the PRL-releasing effect of both quipazine and D-fenfluramine. These results suggest that the effect of these drugs on PRL release is mediated through a serotonergic mechanism in the brain.

5,7-Dihydroxytryptamine↗

[The behavior of the a and the t indices and the systolic times in myocardial infarct].

A study of the behaviour of the a and telediastolic indices and systolic times in patients presenting the sequelae of myocardial infarction is reported. It is pointed out that the earliness of a and t index variations with respect to those of systolic times is an indication of the sensitivity of the investigation which offers invaluable pointers to subsequent treatment. It is also stressed that previous hypertension and/or coronaropathy are more important than the infarction itself in creating dyskinetic zones of the myocardium and, consequently, the haemodynamic changes observed with phonomechanocardiography.

Coronary Disease↗