Biomedical subjects

G Tassinari

Publications and source records attributed to G Tassinari.

7 recordsLinked to original sources

PubMed1992

[Phyllodes tumor of the breast].

The diagnosis of benign, malignant or borderline phylloides tumor of the breast is based on a combination of clinical and histological features but the biological behavior of this neoplasm is not often predictable: the most important indicators of malignant behavior are underscored. Only a few patients with malignant or borderline lesions develop distant metastasis; local recurrences do not appear to effect survival: as a consequence, wide resection should to be primary treatment and axillary dissection is not worthwhile.

Aged↗

PubMed1992

Central changes of beta-endorphin-like immunoreactivity during rat tonic pain differ from those of purified beta-endorphin.

Several studies have described changes in beta-endorphin-like immunoreactivity (beta-ELI) in the rat brain in response to pain and stress stimuli. In order to ascertain the components of beta-ELI, brain samples of rats experiencing acute prolonged (tonic) pain were evaluated for their beta-ELI and later submitted to a chromatographic purification allowing the measurement of beta-endorphin (beta-EP) and acetyl beta-EP. The chromatographic analysis of both ventromedial hypothalamus (VMH) and periaqueductal grey (PAG) homogenates indicates that beta-ELI is distributed in several fractions including shortened forms of beta-EP and their respective acetylated compounds. Quantitatively, while beta-ELI in formalin-injected animals was increased by 48% in VMH and 45% in PAG in respect to controls, the net increase of purified beta-EP was 1100% and 470%, respectively, for VMH and PAG. Moreover, the maximal increase of beta-ELI was evident at 120 min, in both tissues. In contrast, the beta-EP peak was reached at 30 min in VMH and at 60 min in PAG. Acetyl beta-EP was unchanged by treatment in both central areas. No correlation of beta-ELI and beta-EP was found in VMH. These data demonstrate that the evaluation of beta-ELI gives a poor estimate of beta-EP changes, due to several components of the endorphin family.

Animals↗

PubMed1991

Position of axons in the cat's optic tract in relation to their retinal origin and chiasmatic pathway.

The positions of the crossed and uncrossed optic axons of distinct diameter classes has been examined in the optic tract of the adult cat. In addition, the retinal origin of axons occupying different positions within the tract has been studied. Since the position of a fibre within the optic tract reflects its time of arrival during development, we have used axonal position as an indicator of age and have related this to the chiasmatic pathway choice of the axons. Cats were either monocularly enucleated, to reveal the position and diameter of surviving crossed and uncrossed optic axons in semithin and thin sections, or implants of horseradish peroxidase (HRP) were placed so as to retrogradely label the ganglion cells giving rise to axons within the deep (early arriving), or superficial (later arriving) parts of the tract selectively. This was accomplished by either 1) surgically implanting HRP into the superficial portion of the optic tract, via a transbuccal approach, or 2) making such a transbuccal transection of the superficial fibres, followed by intracerebral injections of HRP to retrogradely label the surviving, deeper, optic axons from their target nuclei. The deep parts of the optic tract contain fine and medium, crossed and uncrossed axons arising from mainly medium sized cells in the contralateral nasal and the ipsilateral temporal retina; there is a clear line of decussation. In contrast, the superficial parts of the tract contain mainly fine diameter axons arising from small cells in the whole contralateral retina, and a small proportion of large diameter axons arising from large, alpha cells in the whole contralateral retina and in the ipsilateral temporal retina. The likelihood that axons from the temporal retina will project contralaterally therefore increases as development proceeds, since these axons are found in the superficial parts of the tract only. This suggests that a time-dependent signal that weakens with age is responsible for directing early arriving optic axons from the temporal retina to take an exclusively uncrossed course.

Animals↗

PubMed1991

Central beta-endorphin system involvement in the reaction to acute tonic pain.

The involvement of the beta-endorphin (B-EP) system during acute prolonged (tonic) pain was investigated by biochemical and behavioral approaches in freely-moving rats after subcutaneous injection of a small amount of a dilute formaldehyde solution (0.08 ml, 5%) in a forepaw. Beta-endorphin-like immunoreactivity levels were increased over the respective control groups in rats killed 30, 60 and 120 min after injection in discrete regions of the rat brain, namely ventro-medial hypothalamus, ventro-basal thalamus and periaqueductal gray matter, and at 30 and 60 min in postero-medial thalamus. In a separate group of experiments a small amount of anti-B-EP or normal rabbit serum was injected in the lateral ventricle; 6 h later rats received formalin injection as in previous groups and their behavior was scored over the following 2 h. A significant hyperalgesia (as expressed by an increase in the amount of time rats spent licking or chewing the injected paw) was observed 10-50 min and 70-80 min after formalin in the anti-B-EP icv-injected group. Other behavioral parameters such as general motor activity, grooming and limb flexion were not different in the two groups, nor was animal behavior prior to formalin injection. Altogether these data suggest that the central beta-endorphin system is triggered by prolonged noxious stimulation in freely-moving animals, and in turn plays a physiological role in the modulation of the reaction to, or perception of, tonic pain.

Acute Disease↗

PubMed1979

Iconic storage in the two hemispheres.

Three experiments have tested for the existence of laterality effects in iconic storage by employing a Sperling partial-report paradigm and lateralized presentations of alphabetical or pattern material. Even though an overall laterality effect was found in favor of the right visual field for the alphabetical material and in favor of the left visual field for the pattern material, the amount and time decay of partial-report advantage was similar in the two visual fields. These results indicate that hemispheric asymmetries occur beyond the iconic stage of visual information processing.

Discrimination Learning↗

PubMed1978

[Some human mycoses].

The increase in cases of mycosis, especially those due to "opportunistic fungi", is examined. Reference is made to some rare cases of infection that appear to show that some fungi not usually regarded as pathogenic, but merely as parasites of animals and plants, now tend to result in human infection. Various clinical and epidemiological features of "deep mycosis" caused by fungi with dimorphism are also discussed.

Aspergillosis↗

PubMed1977

Influence of spatial stimulus-response compatibility on reaction time of ipsilateral and contralateral hand to lateralized light stimuli.

In a simple reaction time task, key-pressing responses to unpatterned light stimuli presented in the right and left visual fields were faster for the hand ipsilateral to the visual stimulus than for the hand contralateral to the stimulus. The superiority of the ipsilateral reactions was seen also when responses were made with the hands crossed, so that such a superiority cannot be attributed to spatial compatibility between the side of the stimulus and the position of the response device. Similar results were obtained in a reaction time task of the Donders's c-type. It is argued that these laterality effects in visuomotor reaction time tasks are best explained by the anatomical relationships between the visual fields, the cerebral hemispheres, and the hands. The possible interaction between these effects and the effects of spatial compatibility between side of stimulus and side of response device are discussed in relation to reaction time tasks of the Donder's b-type.

Adult↗