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Biomedical subjects

A Antonini

Publications and source records attributed to A Antonini.

At least 145 records · Page 8Linked to original sources
PubMed1968

[Thyroid osteosis].

Explore the source record for details and available documents.

Alkaline Phosphatase↗
PubMedDate not supplied

Immediate postoperative retention of visual discriminations following selective cortical lesions in the cat.

Cats were trained preoperatively for brightness discrimination, and 7 pattern and form discriminations, and then retested for preoperative retention on each discrimination. Cortical lesions were then placed in areas 17 and 18 in one group (4 cats), in areas 17, 18 and 19 in another group (3 cats), and in suprasylvian cortex (areas 7, 21, and parts of 19, 5 and the lateral suprasylvian cortex) in a third group (4 cats). Results are also reported for a fourth group with extensive suprasylvian lesions, to which was added an unintended undercutting of areas 17 and 18 (4 cats). While during original preoperative learning the training continued until a fixed, stringent criterion of performance was attained, both preoperative and postoperative retention was tested in short sessions, involving a limited number of trials and a less stringent statistical criterion (significant run). After extensive removal of areas 17 and 18, all cats behaved as though following the cortical lesion they could immediately recognize the discriminative stimuli as efficiently as before, with no need for retraining. On the contrary, the group with areas 17, 18 and 19 lesions showed a substantial postoperative loss of all discriminations, and especially for the more difficult form discriminations, the reattainment of a significant level of performance was hard or impossible within the allotted number of trials. Also in the group with limited suprasylvian lesions, postoperative retention was generally impaired, but the reacquisition of efficient performance was superior to that of the previous group. Finally, large suprasylvian lesions encroaching on the white matter under areas 17, 18 and 19 proved disruptive for all discriminative capacities, both in retention and in relearning. The excellent retention of all discriminations following areas 17 and 18 lesions once again shows that these areas are by no means essential for complex vision in the cat. In addition, the results strongly indicate that the high-level visual capacities of destriate cats are not due to reorganization of readaptation processes occurring in extrastriate areas after a 17/18 removal. The clear-cut retention deficits which were present in cats with cortical lesions more extensive than areas 17 and 18 or outside of the latter areas prove the essential participation of extrastriate cortical areas in visual discrimination including form. However, the distribution of functions among the various visual cortical areas in visual discrimination remains poorly understood.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMedDate not supplied

Epilepsia partialis continua studied by PET.

We report an [18F]fluordeoxyglucose (FDG)-PET study performed in an 11-year-old girl with a 5-month history of epilepsia partialis continua (epc). Visual inspection of PET images showed a hypermetabolic focus in the right central cortex and in the ipsilateral thalamus, which was confirmed by the absolute values of regional cerebral glucose metabolism (rCMRGlu). The thalamic hypermetabolism provides evidence for an involvement of thalamic nuclei in this ictally epileptic process. The scalp EEG revealed a theta-delta and sharp wave focus in the right Rolandic cortex at the same location as the hypermetabolic zone seen in PET. Simultaneously recorded EMG of the left tibialis anterior muscle showed regular jerks, time-locked to the sharp waves at the right central region, and myoclonic 'storms' during focal motor seizures. The results of the brain biopsy and the child's clinical course led us to a diagnosis of 'chronic encephalitis' of Rasmussen.

Brain↗
PubMedDate not supplied

Effect of sensory disuse on geniculate afferents to cat visual cortex.

In the kitten, as little as a week of monocular lid suture during early life causes a remarkable remodeling of the geniculocortical projections serving the deprived eye (Antonini & Stryker, 1993a, 1996). While the physiological effects of monocular deprivation have been shown to be due to competitive interactions between the projections serving the two eyes, it is not known whether these morphological changes are due to competitive interactions or to sensory disuse. We addressed this question by analyzing the morphology of geniculocortical arbors in kittens deprived of patterned vision by binocular lid suture for 1 week or 2 weeks ending at 6 weeks of age. Such deprivation would be expected to affect the afferents serving the two eyes equally, giving neither eye a competitive advantage. The arbors were anterogradely filled with Phaseolus lectin iontophoretically injected into lamina A of the lateral geniculate nucleus. The lectin was visualized immunohistochemically, and single geniculocortical arbors were serially reconstructed in three dimensions. Arbors reconstructed in binocularly deprived animals were compared with arbors serving the deprived and nondeprived eye in animals monocularly deprived by lid suture of one eye for a week and with arbors obtained in age-matched normal controls. Geniculocortical arbors in binocularly deprived animals did not suffer the drastic remodeling of the deprived arbors in monocularly deprived animals. Indeed, arbors in binocularly deprived animals were indistinguishable from arbors in normal kittens or nondeprived arbors in short-term monocularly deprived animals. These results support the notion that competitive mechanisms rather than sensory disuse are responsible for gross morphological remodeling of geniculocortical arbors.

Animals↗
PubMedDate not supplied

Modification of dopamine D2 receptor activity by pergolide in Parkinson's disease: an in vivo study by PET.

It is well known that chronic administration of pergolide and other dopamine agonists may induce a downregulation of dopamine D2 receptors in the rat model of Parkinson's disease (PD). To our knowledge, this effect has not been demonstrated in vivo in patients with PD. At present, the status of striatal dopamine D2 receptors can be studied with use of positron emission tomographic (PET) technology. Five patients with PD chronically treated with levodopa were studied with use of PET and [11C]-raclopride before and after 6 months of pergolide treatment (dose range = 4.5-7.5 mg/d). We found a slight reduction in the specific striatal [11C]-raclopride uptake index (mean reduction 14% in putamen and 9% in caudate) after pergolide treatment. This reduction appears to be related to downregulation of the receptor, although competitive binding of pergolide at the D2 receptor cannot be excluded.

Antiparkinson Agents↗
PubMedDate not supplied

[The HACCP method for personnel education].

In order to guarantee an alimentary safety it is necessary to estimate the real meant sanitary risk as probability of insurgence of microbiological pathologies and to develop the concepts of the HACCP therefore as indicated from D.lgs. 155/97. In six scholastic catering services, some which three had applied system HACCP and three not, have been conduct microbiological analyses on the superficial ones, the staff and the alimony. It has been estimated the effectiveness of the system HACCP observing the modifications been necessary during the trend temporal, through 5 series of samples, carried out in three years 2000-2002. The not optimal situation emerged from the search confirms that the use of the handbook of CPI and the self-control based on method HACCP needs of time and professional contributions for one they corrected management.

Consumer Product Safety↗
PubMedDate not supplied

[Statistical evaluation of the "measure of concordance" between Angle classifications and the ANB angle].

In a sample of 177 subjects 6 to 15 years of age, with various types and degrees of malocclusions, the A.A. measured, with statistical methods, the agreement between Angle and Ballard classifications. The result was a disagreement between the two classifications for Class I and Class II malocclusion and some agreement between the two classifications for Class III malocclusion. The applied discriminant function was not able to classify observations in a better way.

Adolescent↗
PubMedDate not supplied

[Cephalometric study of the results of orthodontic treatment of Class III malocclusion].

It's carried out a research on 60 children, 32 boys and 28 girls, taken from 5-12 of age, affected by Class III malocclusion. All of cases was subdivided in four groups on the ground of the age of orthodontic treatment beginning. Two teleradiographs of each patient were examined, one at the beginning and one at the conclusion of the treatment. About the results reported on the boards, were expressed some considerations on the effects of Class III malocclusions treatment as they result at the cephalometric analysis, in comparison with the starting situation of lack of balance. In every case is pointed out the significance of interception and a more favourable behaviour of cephalometric data in the groups with a earlier beginning of treatment.

Cephalometry↗
PubMedDate not supplied

[Use of vecuronium bromide administered at a constant rate during renal transplantation].

The authors describe a technique of vecuronium bromide perfusion at constant flow used to obtain curarisation during 50 renal transplantations. The muscular effects of the drug were monitored through an electromyographical recorder, so as to adjust the perfusion rate. The dose of vecuronium bromide was 47.7 +/- 0.74 micrograms X kg-1 X h-1 (mean +/- SEM), this being lower than the dose recommended by D'Hollander (60 micrograms X kg-1 X h-1) for patients with normal renal function. Furthermore, no recurarisation was observed. Therefore, vecuronium can be considered as a satisfactory muscle relaxant in patients with renal failure, but neuromuscular monitoring appears to be a most important safety factor.

Adult↗
PubMedDate not supplied

[Induced normovolemic hemodilution. Calculation of the amount of blood to be withdrawn].

The authors study the variation of the hematocrit during a provoked normovolemic hemodilution. To get a predetermined hematocrit rate they use a simple and original biophysical model which gives the exact blood volume to be extracted. Then they use the same method to evaluate the hematocrit of the extracted blood after its conditionnement in packs.

Hematocrit↗