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Biomedical subjects

G Coppola

Publications and source records attributed to G Coppola.

At least 91 records · Page 5Linked to original sources
PubMed1985

Role of retinoids in differentiation and growth of embryonal carcinoma cells.

To study how retinoids promote differentiation and inhibit proliferation of embryonal carcinoma (EC) cells, we have followed their intracellular fate. Retinoic acid (RA) is effectively metabolized to more polar compounds by many EC lines. Unlike RA, retinol is slowly metabolized. Our inability to detect conversion of retinol to RA might indicate that the two retinoids elicit their effects on EC cells in different ways. Retinol added to cultures quickly appears in the nuclear fraction; the proportion associated with nuclei after detergent extraction is initially very low but increases with time. Retinol and RA might be translocated to nuclei by their respective binding proteins [cellular retinol-binding protein (CRBP) and cellular retinoic acid-binding protein (CRABP)]: isolated EC nuclei have specific, independent binding sites for both holoproteins but not their ligands. CRABP cannot be detected in the nucleoplasm of untreated EC cells, but activity is measurable after cells are exposed to RA. Interestingly, incubation with retinol promotes movement of both CRBP and CRABP into the nucleoplasmic fraction. Finally, we have demonstrated that brief exposure to RA dramatically reduces the cloning efficiency of EC cells. Since some cells are unaffected even by lengthy exposures to RA whereas the growth of their progeny is inhibited, we suggest that EC cells can become epigenetically refractory to RA.

Animals↗
PubMed1983

Discriminatory inhibition of protein synthesis in cell-free systems by vaccinia virus transcripts.

The effect of vaccinia virus early transcripts on cellular (globin, HeLa, Chinese hamster ovary) and viral (vaccinia, encephalomyocarditis) mRNA function was studied in reticulocyte and wheat germ cell-free protein-synthesizing systems. Vaccinia virus transcripts of two size classes (8-10 S and 4-7 S), generated in vitro by viral cores, inhibited function of cellular and encephalomyocarditis virus mRNA but not that of vaccinia virus in reticulocyte lysate systems. Mild alkaline hydrolysis or micrococcal nuclease treatment of vaccinia virus in vitro transcripts resulted in a loss of their ability to inhibit protein synthesis directed by HeLa cell RNA. Vaccinia virus in vitro transcripts also selectively inhibited HeLa cell protein synthesis in wheat germ systems, suggesting that double-stranded RNA is not involved in this inhibition of protein synthesis. The addition, to the reticulocyte translating system, of cytoplasmic RNA obtained from infected cells in conjunction with cellular mRNA (globin, HeLa) resulted in the inhibition of synthesis of the globin or HeLa polypeptides with little or no effect on the translation of the vaccinia virus proteins. RNA extracted from vaccinia virions inhibited cellular but not vaccinia virus mRNA function when added to the reticulocyte lysate systems with uninfected or infected HeLa cell cytoplasmic RNA.

Animals↗
PubMedDate not supplied

Double-blind, placebo-controlled, cross-over trial of allopurinol as add-on therapy in childhood refractory epilepsy.

We report the results of a double-blind, placebo-controlled cross-over trial with allopurinol as add-on therapy in childhood refractory epilepsy. Seventeen patients received allopurinol and matched placebo for 12 weeks in 2 doses (10 mg/kg/day during the first week and 15 mg/kg/day thereafter with a washout period of 2 weeks between treatment phases. The total number of seizures was reduced by 50-98% in 4 patients (23.5%) and by 25-49% in another 4 (23.5%). However, the number of seizures remained unchanged in 5 patients (29.4%) and worsened in 4 (23.5%). Adverse side effects (17.6%) were generally mild and transient, suggesting that allopurinol is well-tolerated. A mean follow-up of 10 months of the responders did not show any relevant efficacy of allopurinol as an adjuvant therapy for refractory epilepsy, even at high doses.

Adolescent↗
PubMedDate not supplied

Neonatal hyperekplexia: a case report.

We report the case of a baby with transient generalized stiffness noticeable from the first days of life, hyperreflexia, massive jerks in response to sudden tactile and acoustic stimuli, and long-lasting myoclonic jerks closely resembling epileptic seizures. The father and paternal grandfather both had hyperekplexia. At age 3 years, the child had normal psychomotor development and persistent abnormal startle response to unexpected sounds or touch.

Cerebral Cortex↗
PubMedDate not supplied

A multicentre trial to evaluate the efficacy and tolerability of alpha-glycerylphosphorylcholine versus cytosine diphosphocholine in patients with vascular dementia.

An open clinical trial was carried out to compare the efficacy and the tolerability of 1 g/day alpha-glycerylphosphorylcholine (alpha-GPC) with 1 g/day cytosine diphosphocholine (CDP) both given intramuscularly for 90 days in 120 patients with mild to moderate vascular dementia. The clinical evaluation, carried out at the start as well as halfway through (45 days) and at the end of treatment (90 days), was expressed by psychometric tests (modified Parkside behaviour rating scale, Sandoz clinical assessment geriatric scale, word fluency test, Hamilton's rating scale of depression, narration subtest of Wechsler memory scale). Both treatments produced a definite symptomatic improvement and showed a very good tolerability. The results suggest that in most tests alpha-GPC possessed a statistical higher efficacy and an overall more satisfactory activity assessed by both patients and investigators compared with CDP.

Aged↗
PubMedDate not supplied

Impaired neural conduction in crossed visual pathways in patients with ocular hypertension.

PURPOSE: To evaluate the neural conduction along crossed and uncrossed visual pathways in patients with ocular hypertension (OHT). METHODS: Fifteen patients (mean age 59.1+/-6.8 years) with OHT (IOP>22 mmHg, Humphrey 24-2 with mean deviation [MD]>-2 dB) were enrolled. They were compared to 15 age-matched controls. In OHT patients and control subjects, visual evoked potentials (VEPs) were recorded using full-field checkerboard patterns (the check subtended 15' of visual arc; contrast 80%) reversed at 2 Hz. VEP responses were simultaneously recorded in the homolateral visual cortex (HC) and in the contralateral visual cortex (CC), with respect to the stimulated eye. RESULTS: In OHT patients, VEP P100 implicit times observed in HC and CC were both significantly delayed (analysis of variance, p<0.01) when compared to those of controls, and, in particular, longer in CC than in HC. The interhemispheric differences (ID: P100 implicit time in HC - P100 implicit time in CC) were significantly higher in OHT patients than controls (-3.16+/-1.80 msec and 1.16+/-1.04 msec, respectively, p=0.001). In OHT patients we observed an MD hemifield difference (difference between nasal and temporal MD values) higher than in controls (-0.82+/-0.80 dB and 0.04+/-1.03 dB, respectively, p<0.01) and significantly correlated with the ID (r: 0.836, p<0.001). CONCLUSIONS: The observed asymmetry in the bioelectrical cortical responses and in the visual hemifield parameters suggests that crossed visual pathways could be impaired earlier than uncrossed visual pathways in OHT patients.

Aged↗
PubMedDate not supplied

[Comparison of plasma concentrations of amoxicillin administered by oral and venous routes in neonatal bacterial colonizations].

The amoxicillin is a drug that for the incomplete capacity of intestinal absorption in newborn is give for intravenous way. The use of this way and the duration of treatment impose the separation of the newborn from mother and a proportionate preparation of the nurses for the execution of this therapy. We have compared, in newborn infants, with clinical and laboratory diagnosis of neonatal infection, the amoxicillin's plasmatic concentration after intravenous giving and oral giving, in relation to minimum inhibiting concentration the bacteria cause of neonatal infections. In our study (duration 10 months) the newborn infants were perfectly comparable for gestational age, Apgar's score, birthweight, breastfeeding. The newborn infants, at random, were divided in two groups; the first group (18 newborns) received drug for oral way, the second group (14 newborns) for intravenous way. The dosage was 40 mg/Kg/dose of amoxicillin. The duration of treatment was 4 days. Remarkable was the great individual variability of plasmatic concentration of amoxicillin independently from way of giving. The plasmatic concentrations were nearly similar except for the first half hour (plasmatic concentrations after oral giving was lower). The use of oral way is, therefore, favourable for the facility of giving and effective as the intravenous way in the control of neonatal infections.

Administration, Oral↗
PubMedDate not supplied

Effect of continuous high hydrostatic pressure on the morphology and cytoskeleton of normal and osteoarthritic human chondrocytes cultivated in alginate gels.

OBJECTIVE: To investigate the effect of continuous high hydrostatic pressure on the cell ultrastructure and cytoskeleton of cultivated normal and osteoarthritic (OA) human chondrocytes. METHODS: The effects of continuous hydrostatic pressure (24 MPa) for 3 hrs on normal and OA chondrocytes were assessed by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and immunofluorescence microscopy (IF). RESULTS: Structural differences at the nuclear, cytoplasmic and cytoskeletal levels were observed between normal and OA chondrocytes. Continuous high hydrostatic pressure severely altered normal chondrocytes that became similar in structural organization to OA chondrocytes and further reduced the number of cell organelles involved in the synthesis of collagen and proteoglycans. IF showed major changes in the distribution of actin and tubulin after pressurization in normal and OA chondrocytes. CONCLUSIONS: The results confirm the major role of pressure on chondrocyte ultrastructure. Continuous high hydrostatic pressure caused structural alterations in normal chondrocytes, which obtained similar, if not identical, characteristics to those typical of osteoarthritic chondrocytes.

Aged↗
PubMedDate not supplied

[Epileptic crisis at the onset of SSPE (subacute sclerosing panencephalitis): considerations apropos of a case].

A case of SSPE is reported and discussed; in all the evolution of this history, epileptic seizures were precocious (a long time before the onset of characteristic features of the disease) and dominant. The Authors, also on the basis of the literature (a definite pattern of evolution of epilepsy within SSPE is not reported), emphasize that this disease must be however considered among the possible aetiologies of an epileptic syndrome with onset in childhood.

Adolescent↗