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Biomedical subjects

C Barbieri

Publications and source records attributed to C Barbieri.

At least 55 records · Page 3Linked to original sources

Space exploration with and without the aid of vision in hemisphere-damaged patients.

Space exploration carried out under visual control and in its absence (blindfolded condition) was investigated in 20 RBD patients, 10 LBD patients and 20 normal controls with a modified version of Chedru's test (pressing the keys of a keyboard). Conventional tests for visual hemi-inattention permitted to classify RBD patients in a group with visual neglect (RBD VN+) and a group without visual neglect (RBD VN-). On the visual version of the test both RBD groups showed a preference for pressing the keys ipsilateral to the lesion side, but this tendency was more marked in the RBD VN+ group than in any other brain-damaged group. On the tactile version of the test only RBD VN+ patients showed a gradient favouring the pressing of the ipsilateral half of the keyboard. This ipsilateral preference was, however, significantly less marked than that found when the performance was assisted by vision. No relation between neglect in the blindfolded condition and tactile extinction was found. The nature of space exploration in the absence of vision is discussed and the existence of tactile neglect is questioned.

Attention↗

Attentional shift towards the rightmost stimuli in patients with left visual neglect.

In a search task where four letters were displayed to the right of a central fixation point, right brain-damaged patients with visual neglect showed the fastest response when the target was at the rightmost position and progressively slower responses as it moved towards the center of the display. This finding confirms Kinsbourne's claim that in visual neglect an important role is played by the magnetic attraction that the extreme end of the right structured space exerts on the patient's attention.

Adult↗

Auditory neglect.

Auditory neglect was investigated in normal controls and in patients with a recent unilateral hemispheric lesion, by requiring them to detect the interruptions that occurred in one ear in a sound delivered through earphones either mono-aurally or binaurally. Control patients accurately detected interruptions. One left brain damaged (LBD) patient missed only once in the ipsilateral ear while seven of the 30 right brain damaged (RBD) patients missed more than one signal in the monoaural test and nine patients did the same in the binaural test. Omissions were always more marked in the left ear and in the binaural test with a significant ear by test interaction. The lesion of these patients was in the parietal lobe (five patients) and the thalamus (four patients). The relation of auditory neglect to auditory extinction was investigated and found to be equivocal, in that there were seven RBD patients who showed extinction, but not neglect and, more importantly, two patients who exhibited the opposite pattern, thus challenging the view that extinction is a minor form of neglect. Also visual and auditory neglect were not consistently correlated, the former being present in nine RBD patients without auditory neglect and the latter in two RBD patients without visual neglect. The finding that in some RBD patients with auditory neglect omissions also occurred, though with less frequency, in the right ear, points to a right hemisphere participation in the deployment of attention not only to the contralateral, but also to the ipsilateral space.

Auditory Perceptual Disorders↗

Laser radiation and motility patterns of human sperm.

Human sperm were exposed in vitro to laser radiation. An increase in progressive sperm motility was associated with a faster rate of sperm ATP consumption. Computer-assisted analysis of sperm motility confirmed the positive effect of laser irradiation on velocity and linearity of sperm.

Adenosine Triphosphate↗

The executive and ideational components of apraxia.

Fifty six left brain-damaged (LBD) patients and 38 right brain-damaged (RBD) patients were requested to perform two measures of praxis using the hand ipsilateral to the side of lesion. One task required the accurate imitation of actions made by the examiner and taxed executive abilities; the other task required the patient to pantomime the use of objects that were shown, but not handed, and it also involved an ideational component, i.e., the evocation of gestures. The cut-off point discriminating a normal from a pathological performance was set at the level of the poorest score found in 60 control patients. On both tests apraxia was found to be associated primarily with left brain-damage. However, while on the use of objects test practically only LBD patients failed, on the imitation test there was also a sizeable proportion of RBD patients who showed a mild apraxia. When the performance on the two tests was contrasted, there were as many LBD patients as RBD patients who scored remarkably lower on movement imitation than on pantomiming the use of objects, whereas the opposite dissociation was found almost exclusively in LBD patients. We infer from these data that the left hemisphere dominance for praxis is more marked at the ideational stage and that there is also a minor right hemisphere participation in the control of the executive stage of gesture.

Apraxias↗

Immunological studies in patients with central nervous system tumors.

Impairment of cell-mediated immunity in patients with primary central nervous system (CNS) tumors has repeatedly been reported but data to demonstrate the underlying immunological defect are not univocal. This report concerns a series of 31 patients harboring a glioma in which we studied: peripheral blood T-lymphocyte subpopulations by monoclonal antibody analysis; cellular responsiveness to mitogens; serum immunoglobulin values. The same parameters were also evaluated in 7 cases of intracranial meningioma and in 8 patients affected by non-proliferative, non-inflammatory CNS diseases. Thirty age-matched healthy volunteers formed the control group. Neither impairment of T-cells as regard to number, responsiveness and subsets, nor abnormal Ig values were found in these groups. However two patients, harboring respectively a third ventricle low grade astrocytoma and an anterior callosal glioblastoma, presented a striking T-cells impairment. These findings might suggest a correlation between hypothalamus and immune system, as already postulated by several previous experimental and clinical studies.

Adolescent↗

Effects of FCE20700, a new PGE2 derivative, on gastric acid secretion and cytoprotective processes in man.

The pharmacodynamic effects of FCE20700, a new PGE2 derivative, have been investigated in 6 healthy volunteers given single intragastric (i.g.) and intraduodenal (i.d.) doses of 1 and 2 mg and placebo, according to a double-blind, within-subjects design. For 30-270 min following i.g. administration the effect of FCE20700 on peptone-stimulated gastric acid secretion (AS) was assessed by i.g. titration, and serum gastrin (G) levels were also determined. For the same period after i.d. dosing the effect of the compound on pentagastrin-stimulated AS and on mucoproteins and bicarbonate content in the gastric juice was measured. Blood pressure (BP), heart rate and possible side-effects were monitored. Following i.g. administration there was a moderate, dose-related, significant inhibition of AS; significant inhibition of G levels was observed only after the highest dose. After i.d. administration there was a very modest though dose-related and significant inhibition of AS; a brief maximal increase in mucoproteins and in bicarbonate levels was apparent after the 1 mg dose. After i.d. but not after i.g. administration of 2 mg there was a modest but significant decrease in BP. No side-effects of clinical relevance were reported. The results appear to suggest a major activity of FCE20700 on cytoprotection rather than in inhibiting gastric acid secretion. The observed change in BP may indicate that after i.d. administration there will be some systemic effects of FCE20700.

Adult↗

Effects of kallikrein on the male reproductive system and its use in the treatment of idiopathic oligozoospermia with impaired motility.

A single-blind study on the effects of kallikrein in idiopathic oligozoospermia was carried out. 8 of the 16 patients admitted to the trial were treated with kallikrein 100 K.U. t.i.d., the remaining patients received vitamin E 100 mg t.i.d. Treatment lasted 120 days in both groups. Kallikrein led to an increase in sperm concentration, total sperm count and sperm penetration capacity. Patients receiving vitamin E failed to show any improvement. It is postulated that the increase in sperm concentration could be explained by the positive action of kallikrein on spermatogenesis, due to a stimulatory effect of the drug directly on the Sertoli cell function and on the circulation in the vascular system of the testis.

Animals↗

Primary gastric lymphoma: a review of 45 cases.

Primary gastric lymphoma accounts for about 2% of gastric neoplasms. The prognosis of patients affected with non-Hodgkin's gastric lymphoma appears better than for other lymphatic sites. In a retrospective study, the authors have analyzed 45 patients, by evaluating the histopathologic characteristics and relative prognostic factors. The main factors significantly influencing 5-yr survival are: serosal penetration (31.17% vs. 71.2%, P less than 0.05), regional lymph node involvement (53.07% vs. 68%), and clinical stage of disease (IE: 85.6%, IVE:10%, P less than 0.001). The histologic characteristics, the high or low grade of malignancy, and patient age can also be considered important prognostic factors, but not statistically significant in our series of cases. Comparison between overall survival and disease-free survival of patients in stages IE and IIE who underwent surgery alone, with those who had chemotherapy and/or radiotherapy after surgery shows a higher survival (85.6%) of the group who had combined treatments, even though this difference is not statistically significant.

Adult↗

Long-lasting prolactin-lowering effect of cabergoline, a new dopamine agonist, in hyperprolactinemic patients.

The new long-acting ergoline derivative cabergoline was given orally in a single dose of 300 micrograms to 15 hyperprolactinemic patients (including 4 acromegalic patients, 2 of whom were dopamine responsive). Serum PRL and GH levels were determined before and 3, 4, and 6 h and 1, 2, 3, 4, 5, 6, and 7 days after treatment. A control test with a single oral dose of 2.5 mg bromocriptine was also performed; serum PRL and GH levels were measured at the same time intervals for 2 days. Cabergoline induced a marked fall in serum PRL which began within 3 h and continued for 7 days. The maximal decrease ranged between -49.2% and -55.2% and occurred after 2-5 days. This maximal effect was only slightly less than that 6 h after bromocriptine treatment (-63.8%). After cabergoline treatment, serum GH levels did not change significantly in either nonacromegalic or acromegalic patients, whereas the two dopamine-responsive acromegalic patients had a marked GH fall after bromocriptine. A moderate blood pressure decrease, more evident in the standing position, occurred after both cabergoline and bromocriptine treatments. The only symptomatic side-effect was orthostatic hypotension after cabergoline in an elderly woman. These data indicate that cabergoline has potent and prolonged dopaminergic activity and may prove suitable for once weekly treatment of hyperprolactinemic patients.

Adult↗

Lack of effect of deflazacort, a novel glucocorticoid, on basal and TRH-stimulated prolactin and thyrotropin levels in healthy subjects.

The possible relationship between cortisol inhibition induced by deflazacort, a new glucocorticoid, and impairment of prolactin (PRL) and thyrotropin (TSH) secretion in healthy volunteers has been investigated. In 8 healthy subjects deflazacort pretreatment partly inhibited cortisol secretion but did not affect basal or TRH-stimulated secretion of PRL and TSH in comparison to placebo. After dexamethasone, there was the anticipated complete suppression of cortisol secretion, no change in PRL secretion, either in basal conditions or after TRH, and significant inhibition of the TSH response to TRH. No significant change in GH, aldosterone or renin secretion was observed after deflazacort or dexamethasone.

Adult↗

Effect of nifedipine on gastric acid secretion and gastrin release in healthy man.

Nifedipine, a calcium-channel antagonist widely used in cardiovascular disease, has recently been reported to be effective in the treatment of oesophageal motor disorders. The effect of a single therapeutic dose of nifedipine (20 mg p.o.) has been evaluated on basal and submaximal pentagastrin-stimulated gastric secretion and meal-stimulated gastrin release in healthy man. In comparison with placebo, nifedipine significantly decreased both basal and stimulated gastric acidity and juice volume, whereas only a slight but insignificant reduction in meal-stimulated gastrin levels was observed after drug administration. The results are in agreement with previous reports that calcium is involved in stimulus-secretion coupling in the human parietal cell. They do not confirm the effect of calcium on G-cells, although it is likely that doses of nifedipine higher than those commonly used might be effective in the reduction of gastrin secretion.

Adult↗

Effect of L-dopa with and without inhibition of extra cerebral dopa decarboxylase on gastric acid secretion and gastrin release in man.

The present study was undertaken to investigate the possibility that central nervous system monoaminergic pathways may play a role in the control of gastric acid and gastrin secretion in man. Submaximal pentagastrin stimulated (0.25 micrograms/kg/h) gastric acid secretion, as well as basal gastrin concentrations were studied in two groups of subjects. The first group received oral administration of placebo and the catecholamine precursor L-dopa (500 mg); the second group was treated with placebo and the association of L-dopa (100 mg) plus carbidopa (35 mg) after pretreatment with carbidopa (50 mg every six hours for four doses), a schedule which is known to increase brain catecholamine concentrations. In comparison with placebo, stimulated gastric acid secretion was reduced by L-dopa alone, whereas was not modified by L-dopa plus carbidopa. Basal gastrin concentrations were increased after L-dopa and after L-dopa plus carbidopa. These data show that basal gastrin concentration is raised by central catecholamine augmentation; but gastric acid secretion seems to be influenced by changes of peripheral catecholamine concentrations. It is suggested that dopamine and perhaps noradrenaline, but not adrenaline, are important in these effects.

Adult↗

Relationships among pleasure, anxiety and physiological response patterns during the sexual sequence in normal and dispermic subjects.

We examined the reported subjective level of pleasure and anxiety usually perceived during the four phases of the sexual sequence by 18 dispermic patients and 18 normal subjects. Relevant differences exist between the two groups in their perception of both emotions. The role of pleasure and anxiety in modulating some reflexive biological responses of the sexual sequence is discussed.

Adult↗

Lack of effect of cimetidine on the renin-angiotensin-aldosterone system in man.

It is widely accepted that angiotensin II, ACTH and potassium are the major factors controlling the release of aldosterone. Conflicting results have been reported about the role of serotonin, dopamine and histamine. To evaluate the possible involvement of H2-histaminergic receptors, the effect of intravenous injection of 400 mg cimetidine on the renin-angiotensin-aldosterone system has been evaluated in 10 healthy volunteers. The administration of cimetidine did not induce a significant change in plasma aldosterone level or in its major controlling factors.

Adult↗

Effects of acute administration of zetidoline, a new antidopaminergic drug, on plasma prolactin and aldosterone levels in man.

The neuroendocrinological effects of acute oral administration of 20 mg zetidoline, a new antipsychotic drug with antidopaminergic properties, were evaluated in 8 healthy volunteers, by a double-blind, crossover comparison with placebo. Zetidoline significantly increased serum prolactin (p less than 0.01 at 1-3 h; p less than 0.05 at 4-6 h). No significant change was observed in blood levels of aldosterone, renin, cortisol, growth hormone and electrolyte, or in blood pressure and heart rate. The data suggest that the drug increases prolactin through blockade of dopaminergic receptors. The lack of change in the aldosterone levels may be evidence against the hypothesis of dopaminergic control of aldosterone secretion.

Adult↗