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Biomedical subjects

G Rosati

Publications and source records attributed to G Rosati.

At least 91 records · Page 5Linked to original sources
PubMed1989

Modulation of flexor carpi radialis H reflex by lateral tilts in man.

Static vestibular influences on upper limb flexor tone were studied in man by analyzing the changes in flexor carpi radialis H reflex area with lateral tilting of the longitudinal body axis. Ten healthy volunteers and 2 labyrinthine defective patients were tested in an experimental situation designed to minimize all afferent inputs except vestibular ones. Each subject was seated on a chair which could be tilted laterally to the left or the right from the vertical. Head and trunk were fixed upright, upper and lower limbs in half-flexed position and forearm in an intermediate position between supination and pronation. Lateral tilting was applied at random from the vertical (0 degrees control position) to left and right (4 degrees, 8 degrees, 12 degrees, 16 degrees, 20 degrees test positions). Each test position was followed by a return to 0 degrees and in each control and test position 20 consecutive H reflexes were recorded. The data observed in the normal subjects showed flexor tone inhibition in the arm which was tilted downwards and facilitation in the contralateral arm. These findings suggest that in man, like in animals, labyrinth reflexes act asymmetrically and in the opposite direction to neck reflexes.

Adult↗
PubMed1989

Epidemiological study of myasthenia gravis in Sardinia, Italy (1958-1986).

From 1.1.1958 to 31.12.1986, 110 cases of MG were observed in Sardinia, with a mean annual incidence of 2.5 x 1,000,000 inhabitants and prevalence rates of 7.5, 17.6, 31.4 and 45.0 x 1,000,000 inhabitants respectively (prevalence days: 15.10.1961, 24.10.1971, 25.10.1981 and 31.12.1986). The disease was found to be more frequent in women. There were no differences in the distribution of MG in various areas of the island. The muscle group more frequently involved at onset was the ocular. In 6.4% of patients an association with thyroid disorders was observed. The mortality of MG patients was significantly higher than expected. Removal of the thymus, carried out in 58 patients, was shown to be useful in the treatment of the disease, particularly in patients without thymomas. No familial cases were observed.

Adult↗
PubMed1989

Inhalation of adenosine 5'-monophosphate increases methacholine airway responsiveness.

Airway hyperresponsiveness is a characteristic feature in asthmatic subjects, but the mechanism of the hyperresponsiveness is not known. The purpose of this study was to investigate whether methacholine airway responsiveness was increased 24 h after inhalation of adenosine 5'-monophosphate (AMP). Ten atopic asthmatic subjects and six atopic normal subjects were studied on 4 study days. On the 1st day, a methacholine inhalation test was performed, followed within 48 h by an AMP inhalation test. Seven days later the second AMP test was performed, and 24 h later the methacholine inhalation test was repeated. Response was measured using partial flow-volume curves, and the concentration required to cause a 40% fall in the partial flow-volume curve (PC40) was calculated. The geometric mean methacholine PC40 fell from 1.36 mg/ml on day 1 (before AMP inhalation) to 0.71 mg/ml on day 4 (24 h after AMP inhalation, P less than 0.01). There was no change in the mean PC40 for adenosine on the 2 study days (5.82 and 7.06 mg/ml, P greater than 0.1). These findings suggest that adenosine release may contribute to the increase in airway responsiveness after allergen challenge.

Adenosine Monophosphate↗
PubMed1988

Tonic neck reflexes on upper limb flexor tone in man.

The asymmetric tonic neck reflexes on upper limbs in man have been studied by analyzing the changes in flexor carpi radialis H-reflex amplitude following body rotation around the longitudinal axis with a stationary head. In eight normal subjects 15 consecutive H-reflexes were recorded from the right flexor carpi radialis muscle at each test position. The tested body rotation angles were 4, 8, 12, 16, and 20 degrees both to the right side and to the left side. Before and after each test position 15 H-reflexes were recorded at 0 degrees. The linear correlation coefficient r, computed by plotting the H-reflex amplitudes against the relevant body rotation angles, was significant in all the subjects. The FCR H-reflex amplitude increased with contralateral body rotation (i.e., ipsilateral head rotation) and decreased with ipsilateral body rotation (i.e., contralateral head rotation). It has been suggested that these findings, which are opposite to those observed in animal experiments, are the consequence of the acquired antigravity function of upper limb flexor muscles in man.

Adult↗
PubMed1988

Phenobarbital-induced buccolingual dyskinesia in oral apraxia.

A young woman with oral apraxia and a well-defined brain lesion on CT scan developed buccolingual dyskinesia lasting 40 days after low phenobarbital (PB) doses. Disruption of the corticostriatal glutamatergic pathway from areas 6 and 4 may have been important both in causing oral apraxia and in lowering the threshold for PB-induced buccolingual dyskinesia.

Adult↗
PubMed1988

Eating seizures and distraction-arousal functions. A case study.

Reports of epileptic seizures evoked by eating are very scarce in the literature. A review of the reported cases suggests that various mechanisms may act as triggering factors in this form of reflex epilepsy. We studied a 17-year-old boy in whom the seizures precipitated by eating had been prevented by giving him some alerting stimuli during the meal. The attention-arousal coupling sustained by the meal seems to play a role in triggering the attacks.

Adolescent↗
PubMed1988

Incidence of multiple sclerosis in the town of Sassari, Sardinia, 1965 to 1985: evidence for increasing occurrence of the disease.

Prevalence studies carried out in Sardinia from 1975 suggest an increasing occurrence of MS. However, it is questionable whether this increase represents a real change in MS incidence or simply reflects longer survival. Data from 79 patients indicated the average annual incidence for the period 1965 through 1985 was 3.4 per 100,000. On December 31, 1985, the prevalence rate was 69 per 100,000. Evaluation of MS temporal trends showed a significant increase in MS incidence during the study period: values ranged around two per 100,000 in the triennial periods 1965-1967, 1968-1970, and 1971-1973, and around five in each triennium from 1977 onward.

Adolescent↗
PubMed1987

Sardinia, a high-risk area for multiple sclerosis: a prevalence and incidence study in the district of Alghero.

Findings from small descriptive studies carried out in the last few years in Sardinia suggest that this region is now of high rather than medium risk for multiple sclerosis. It is uncertain whether this high prevalence reflects a different approach in case finding over time or a true change in disease occurrence. We report the results of a prevalence and incidence survey conducted in the district of Alghero, a community of 78,000 people in northwest Sardinia. Based on data from 31 patients, the average annual incidence for the period 1971 through 1980 was 4.1 per 100,000. On December 31, 1980, the prevalence rate was 59 per 100,000. The results support the view that Sardinia is now a high-risk area for multiple sclerosis, and further suggest a rise in the occurrence of the disease in recent years.

Adolescent↗
PubMed1987

Influences of neck receptors on soleus motoneuron excitability in man.

We studied the influence of the asymmetric tonic neck reflexes on the excitability of the human soleus motoneuronal pool by mapping the H amplitude as a function of rotation of the body relative to the fixed head. Eight normal adult volunteers were tested. On each subject 15 consecutive H reflexes were recorded from the right soleus muscle, for each of the following test position, 4 degrees, 8 degrees, 12 degrees, 16 degrees, as well as at the control position (0 degrees), both before and after each change in body position. Our results showed that the H reflex amplitude was progressively facilitated for contralateral rotation in respect to the recording side and conversely inhibited for ipsilateral rotation. The results indicate that neck receptors of one side enhance the excitability of the contralateral soleus motoneurons and depress the ipsilateral ones.

Adult↗
PubMed1987

Distribution of diphenylhydantoin in the brain during experimental status epilepticus of the cat.

The distribution of diphenylhydantoin (PHT) (40 mg/kg i.p.) in the brain was investigated in cats with convulsive generalized (group 1) and focal penicillin-induced status epilepticus (group 2), and in controls. A significant increase in the amount of PHT entering the brain during the convulsive status was found, with peak brain levels at 45 min (12 +/- 3.2 micrograms/g vs. 6.0 +/- 0.8 in normal cats, P less than 0.05). In the focal status brain concentrations of PHT reached levels intermediate between controls and group 1 cats. At 15 min, elevated blood levels of the drug were paralleled by increased concentrations in the brain, whereas at 30 and 45 min other factors, such as changes in cerebral blood flow, cerebral pH, vascular resistance, metabolic derangement and blood-brain barrier disruption were presumably responsible for the altered brain PHT uptake. The relevance of these data to clinical practice is discussed, in relation to the treatment of human status epilepticus and the potentially neurotoxic effects of the drug.

Animals↗
PubMed1987

Diabetic polyneuropathy and insulin secretion in type II diabetic patients.

Electrophysiological examination was performed on 50 type II diabetic patients to verify whether insulin secretory reserve is a factor influencing the susceptibility to develop polyneuropathy. The results showed that less significant metabolic derangement related to high insulin secretory reserve, and not the high insulin secretory reserve by itself, may prevent the development of neuropathic disorders. These data are consistent with the current opinion that diabetic polyneuropathy is the consequence of the metabolic derangement caused by chronic hyperglycemia.

Adult↗
PubMed1986

Incidence of multiple sclerosis in Macomer, Sardinia, 1912-1981: onset of the disease after 1950.

Intensive search of all cases of MS occurring in the Sardinian commune of Macomer since 1912 indicated that MS was absent up to the early 1950s. All 13 ascertained cases had clinical onset in the years 1952-1981. During this period, the average annual incidence was 4.8 per 100,000; the highest incidence was found in the period 1957-1961, slowly decreasing up to 1981. MS was probably introduced after 1945, when the centuries-old isolation of Macomer ended and the native population came into contact with individuals from high- and medium-risk areas.

Adult↗