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Biomedical subjects

G Savettieri

Publications and source records attributed to G Savettieri.

At least 73 records · Page 4Linked to original sources
PubMed1987

Cellular mechanism of action of thyroid hormones.

It has emerged in the last decade that the molecular mechanism of action of thyroid hormones resembles that of steroids; thyroid hormones indeed exert their effects mainly by directly regulating gene expression, on association with specific chromatin-bound receptors. Of the two thyroid hormones, thyroxine (T4) appears to be a sort of prohormone, whereas triiodothyronine (T3) seems to be the active form; in this respect, T4-deiodination, which occurs at the level of the target tissues, may be crucial in the local homeostasis of T3. Moreover, many cellular compartments, other than the nucleus, can bind thyroid hormone, and at least some of these further sites might play some role in modulating T3 supply to the nucleus. The binding of the T3-receptor complex to chromatin is likely to regulate the structural organization of specific genes and, in some instances, of the chromatin as a whole.

Animals↗
PubMed1987

Triiodothyronine-induced shortening of chromatin repeat length in neurons cultured in a chemically defined medium.

At the time of terminal differentiation, mammalian cortical neurons undergo a dramatic change in the structural organization of their chromatin: the nucleosomal repeat length shortens from approximately 200 base pairs in fetuses to a value of 165 base pairs after birth. These events occur several days after the end of neuronal proliferation. Previously, we reported that rat cortical neurons cultured in a very selective synthetic medium were not yet programmed to these events at the end of mitotic cycles. Herein, we report that addition of triiodothyronine to neuronal cultures induces a shortening of the chromatin repeat length comparable to the natural one.

Animals↗
PubMed1987

Inhibition of glial proliferation in vitro by serum from patients with multiple sclerosis.

Primary cell cultures from fetal rat CNS have been employed to evaluate the effects caused by the addition of serum from patients affected by multiple sclerosis (MS). MS-serum supplemented media caused a decrease in [3H]-thymidine incorporation into the cultures, thus indicating an inhibitory effect on proliferating glial cells. Sera from patients in remission stage of the disease showed an inhibitory effect not significatively lower than those from patients in acute stage. These results suggest that glial cells may be a target of circulating factors present in MS.

Adult↗
PubMed1987

HLA associations with multiple sclerosis in Sicily and Malta.

The islands of Sicily and Malta have very different prevalence rates for multiple sclerosis (MS): at least 44 per 100,000 in Sicily and only 4 per 100,000 in Malta. In Northern Europe, MS is associated with HLA-DR2/Dw2. The other components of the commonest DR2-containing haplotype of this region, HLA-A3-B7-DR2-Dw2, also tend to be present at higher frequency in MS patients. HLA Class I and II antigen frequencies and associations in controls and MS patients from Sicily and Malta were studied to discover whether they might account for the difference in MS prevalence. In Sicilian MS patients, DR2 is increased in frequency compared with controls and four out of five DR2-positive patients also type as Dw2. In the Maltese population, DR2 is present at high frequency but approximately half of the DR2 positive individuals do not type as Dw2 so that DR2 is probably most commonly present as part of Class II haplotypes other than those commonly associated with MS. Additional differences in HLA profile of the Sicilian and Maltese populations were found when HLA-A, -B, and B-DR antigen associations were examined. Therefore, some of the difference in MS prevalence might be explained by genetic factors.

Cross-Sectional Studies↗
PubMed1986

Peripheral nerve involvement in chronic liver disease. Clinical and electrophysiological study.

A clinical and electrophysiological study was carried out on 19 selected patients with chronic liver disease. Clinical signs of peripheral nerve involvement were found in 4 patients (21%); while electrophysiological impairment was present in 11 patients (57.8%). These abnormalities were mostly limited to the sensory and motor fibers of the tibialis posterior nerve. Our data confirm the presence of peripheral nerve involvement in chronic liver disease, and that it may be evidenced by careful electrophysiological examination.

Adult↗
PubMed1986

Rat CNS neurons are not yet programmed to shorten their chromatin repeat length at the end of fetal neurogenesis.

Neurons from rat fetal cerebral hemispheres were grown in a synthetic medium (Maat medium), as previously described, for different periods of time. The repeat length of their chromatin was determined by micrococcal nuclease digestion and compared with that of neurons isolated from postnatal rat brain of corresponding ages. In contrast to the in vivo situation, we found that neurons, dissociated at the 16th gestational day and cultured in vitro, did not undergo the shortening of their chromatin repeat, thus indicating that, at the end of their mitotic cycles, they are not yet programmed to this event.

Aging↗
PubMed1986

A further study on the prevalence of multiple sclerosis in Sicily: Caltanissetta city.

The prevalence of probable multiple sclerosis (MS) in Caltanissetta city, Sicily, is at least 51 per 100,000. If possible multiple sclerosis patients are included, it is 54 per 100,000. This value is similar to that found in other cities in Sicily: Enna, Monreale and Agrigento. The high prevalence of multiple sclerosis in Caltanissetta confirms the previous data on Sicily and emphasises the importance of small population studies in the epidemiology of MS.

Adolescent↗
PubMed1985

Formulation of a novel synthetic medium for selectively culturing rat CNS neurons.

Dissociated cells from rat fetal cerebral hemispheres were grown in surface adhering culture using a novel synthetic medium (Maat medium) and compared with those grown either in the presence of serum or in the chemically defined medium described by Bottenstein and Sato. The addition of various compound combinations allowed us to lower insulin concentration to almost physiological levels. Maat medium improved the purity and longevity of neuronal cultures. The purity of neuronal cultures grown in different media was checked both by immunofluorescence and by the analysis of [3H]thymidine incorporation.

Animals↗
PubMed1984

Rat CNS cell culture. Enhancement of neuronal survival and delay of glial proliferation by serum from patients with multiple sclerosis. A morphological study.

The addition of serum from multiple sclerosis (MS) patients to the culture medium of dissociated cells from cerebral hemispheres of rat embryos caused a delay in glial proliferation and an enhancement of neuronal survival. Sera from normal individuals and patients with other neurological diseases failed to show this effect. These morphological observations are interpreted as the outcome of inhibition of in vitro gliogenesis.

Animals↗
PubMed1983

Selective culture of rat CNS neurons in a synthetic medium.

A Chemically Defined Medium is described which facilitates the survival of neurons in primary cultures of rat cerebral hemispheres. More than 90% of all cells were identified as neurons using neurofilament as a marker in an immunocytochemical assay. In contrast, serum-supplemented medium, by stimulating nonneuronal cell proliferation, hinders the survival of neurons in culture.

Animals↗