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Biomedical subjects

C Billard

Publications and source records attributed to C Billard.

At least 109 records · Page 6Linked to original sources
PubMed1984

[Accidental epileptic seizures in children].

The authors report a series of 71 children admitted to a general pediatric hospital for a first non febrile, non symptomatic seizure and observed for an average of 6 years and 5 months. Among these patients, 19 cases corresponded to an isolated unexplained seizure without paroxysmal E.E.G. abnormalities, which did not reappear without treatment in a mean follow-up period fo 5 years and 3 months. The typical features of these "accidental seizures" are compared with other types of epilepsy. Finally, these "accidental seizures" can be classified into 2 groups: atonic seizures in the young child (1-4 years) and partial seizures in older children. A statistical analysis was undertaken to define the risk factors for recurrence after the first epileptic attack. A low recurrence risk is expected for children between 1 to 4 years with atonic type of seizures without paroxysmal E.E.G. abnormalities while there is a high recurrence risk for children under 1 year with generalized seizures and paroxysmal E.E.G. intercritical abnormalities.

Adolescent↗
PubMed1983

Effects of differentiation inducers on diphenylhexatriene fluorescence polarization in intracytoplasmic and plasma membranes from Friend erythroleukemia cells.

Treatment of Friend leukemia cells with dimethylsulfoxide or hexamethylenbisacetamide, which induced erythroid differentiation, resulted in enhancement of fluorescence polarization of diphenylhexatriene in not only plasma membranes, but also in intracellular membranes. In a cell variant resistant to induction, the polarization values of intracellular membranes were not affected by the inducing agents, whereas plasma membranes had the same enhancement of polarization values as in sensitive cells. Therefore, Friend cell differentiation can be associated with the effect of the inducers on intracellular membranes, but not with the effect on plasma membranes.

Acetamides↗
PubMed1983

Membrane dynamics in human leukemia and lymphoma cells. pH dependency of diphenylhexatriene fluorescence polarization.

Membrane dynamics of human leukemia and lymphoma cell lines were analyzed by investigating the effect of pH on fluorescence polarization (P) of the lipophilic probe diphenylhexatriene (DPH). The degree of P varied as a function of pH, depending on the cell lines. These variations were not detected in phospholipid vesicles. In addition, they were prevented by treatments with glutaraldehyde, sodium azide or phenylmethylsulfanyl fluoride, a specific protease inhibitor. Therefore, these P value changes might be influenced by protein modification.

Cell Division↗
PubMed1983

Analysis of ribosomal RNA in human fibroblasts continuously treated with hydrocortisone.

The prolongation of the limited lifespan of human embryonic lung fibroblasts by hydrocortisone was previously associated with increased uridine incorporation into ribosomal RNA (rRNA). Using polyacrylamide gel electrophoresis, we show here that the continuous treatment with 12 microM hydrocortisone results in increased uridine incorporation into rRNA precursors in cells stimulated to grow by serum, but not in resting cells, suggesting that the hormone does not directly activate rRNA transcription. Chase experiments indicate that the stability of 28S and 18S rRNA is enhanced by hydrocortisone in quiescent cells but not after serum refeeding. Similar results were also observed for transfer RNA (tRNA). Therefore, these effects of hydrocortisone seem to be indirect consequences of pleiotropic actions of glucocorticoid, such as stimulation of processes involved in cell proliferation and inhibition of lysosomal enzymes.

Blood↗
PubMed1983

Serum-controlled membrane dynamic changes in growing human leukemia and lymphoma cells.

The relationship between membrane dynamics and cell growth in human leukemia-lymphoma cell lines of B, T or nonB-nonT phenotype was studied by fluorescence polarization (P) with the probe diphenylhexatriene. Cyclic variations in the degree of P were found as a function of time after subculture. The P value decreases within three hours, until a minimal value obtained before the phase of logarithmic growth. Then, P increases up to its presubculture value. The extent of these variations is not correlated to the differentiation phenotype of the cell lines, nor to their pathologic origin. Experiments with dialyzed or not depleted medium, show that these changes are seen only in the presence of fresh serum. Moreover, the P values vary with the ratio of serum concentration to cell number. These P value modulations are related to subsequent variations in proliferation rate, except in the immature non B-non T REH cells, which grow independently on the serum to cell ratio. It is concluded that changes in the dynamic organization of membrane components are specific for each cell line and are controlled by serum factors.

Animals↗
PubMed1983

[Electroclinical and developmental aspects of epilepsy in the aphasia-epilepsy syndrome].

76 children are studied--66 from the literature and 10 from a personal series--who developed epileptic seizures, paroxysmal EEG abnormalities and language deterioration after a period of normal development of language. The clinical features of the fits, the age at which the seizures appear and disappear, the age of the EEG normalization and the normal clinical and radiological examinations were reminiscent of partial benign epilepsies of childhood. Shortly after the language deteriorates, the awake EEG exhibits slow spikes that are diffuse or predominate in the temporal areas, sometimes asymmetrically. During sleep, the paroxysmal abnormalities are clearly bilateral and continuous or subcontinuous. Spontaneously or under medications, the intensity of the paroxysmal abnormalities decreases before clinical improvement occurs. In comparison with the mutism resulting from acquired hearing loss, it is suggested that the language disturbances in these children result from a functional disorganization of the language centers due to the important intercritical EEG abnormalities. In some children, these functional disturbances could result from a benign epilepsy. This view leads to discuss the prognosis and the therapeutic possibilities.

Anticonvulsants↗
PubMed1982

[Ischemic cerebral softening in newborn infants. Possible etiology of neonatal convulsive states].

The authors report on 8 cases of full term neonates presenting, between the 8th and 72nd hours of life, with several often subintrant partial seizures, always in the same area for a given child. Pregnancy, delivery and the first hours of life had been normal. The first CT scan (performed a few hours to 3 days after the first fits) showed a triangular hypodensity with internal vertex, still observed at the second examination, with reduced dimensions and fuzziness of the edges. The features and localization, always in an elective arterial area, suggested an arterial infarction. The date of occurrence, the probably embolic nature and the etiology of such an arterial ischemia are discussed. The clinical, electric and CT-scan homogeneity of the picture is emphasized, as it makes diagnosis easy. Prognosis is relatively favorable among neonatal seizures states, except for possible intellectual and epileptic sequellae.

Anticonvulsants↗
PubMed1982

[Bacteriologic monitoring of external ventricular drainage in children].

The authors report 27 cases of external ventricular drainage employed in children. The usage of this technique caused neither infection nor surinfection in any of the cases. It is difficult to interpret the analysis of the cerebrospinal fluid thus obtained. Decisive criteria for recovery or non infection can be derived by studying the isozymatic profile of the L.D.H. (lactic dehydrogenase).

Adolescent↗
PubMed1981

[Acquired aphasia in epileptic children--four cases with electrical infraclinic status epilepticus during sleep (author's transl)].

Four cases of acquired aphasia in epileptic children, associated with sub-continuous bitemporal paroxysmal activities (PA) during sleep, are described. Clinical improvement always followed the decrease or the unilateralization of PA. Persistence or aggravation of aphasia was observed when PA again became bitemporal and sub-continuous. Electroencephalographic characteristics of PA during sleep stages are described. Relationships of these cases with the 'sub-clinical electrical status epilepticus induced by sleep' and the physiopathology of aphasia are discussed.

Aphasia↗
PubMed1981

Effect of pH on fluorescence polarization of DMSO induced Friend leukemic cells.

The effect of DMSO on Friend leukemic cell membranes was investigated in an inducible cell line (FLC) and in cell variant resistant to DMSO induction (RFLC). Fluorescence polarization (P) studies carried out at 37 degrees C with diphenyl hexatriene (DPH) have shown that P values change according to the pH, being maximum in alkaline buffer. These changes were altered when cells were grown in the presence of DMSO. Changes in P values according to the pH were abolished by glutaraldehyde and by sodium azide. Fluorescence polarization analysis of FLC cell line carried out at 4 degrees C have shown higher P values which also changed according to the pH. In DMSO induced FLC or in RFLC grown with or without DMSO, these changes were not seen. It is therefore concluded that P value changes related to pH reflect changes in the lipid-protein interactions of cell surface membrane. It is also suggested that these interactions are altered by DMSO.

Animals↗
PubMed1980

Effect of low dose rate irradiation on the division potential of cells in vitro. VII. Human fibroblasts from young and adult donors.

Lung and skin fibroblasts from young and adult donors were irradiated with low dose rate ionizing radiation. Experiments show that in fibroblastlike cells from human adult donors there are three main types of response: irradiation can decrease only the total number of cells produced, it can also decrease the number of subcultures, and in some instances it can prolong the growth potential. Previous experiments suggested that these responses are genetically determined. They may have implications concerning the donor's proneness to cancer.

Adult↗
PubMed1980

Membrane dynamics of Friend leukaemic cells. I. Changes associated with cell growth.

The relationship between membrane dynamics and cellular growth of Friend leukaemic cells (FLC) was studied by fluorescence polarization (P) using diphenyl hexatriene (DPH). The P-value changes as a function of the state of the cells being maximum in the growing state. The P-value is also influenced by serum concentration and this effect appears to be a passive process.

Animals↗
PubMed1980

Membrane dynamics of Friend leukaemic cells. II. Changes associated with cell differentiation.

In a previous study, using fluorescence polarization (P) with diphenyl hexatriene (DPH), it was shown that growing and resting cells have different P-values. This property has now been used to investigate the membrane action of dimethylsulfoxide (DMSO) and hexamethylene bisacetamide (HMBA), two inducers of Friend leukaemic cell (FLC) differentiation. Both an inducible cell line (FLC) and a resistant variant cell line (RFLC), had the same characteristics regarding P-values. During the differentiation process in the FLC cell line, further changes in P-values were observed. In the resistant cell line, these changes in P-value were not seen. This suggests that these inducers of differentiation are acting at the cell membrane.

Acetamides↗
PubMed1979

[Acute polyradiculoneuritis in children. Clinical and developmental aspects. Prognostic factors apropos of 100 cases].

The main clinical features of acute infectious polyneuritis are described from a study of 100 cases. The distinction between Guillain-Barré syndrome and the atypical forms of the condition is arbitrary. In particular, the atypical features (pleocytosis, normal C.S.F. protein, relapses) had no influence on the final prognosis. In contrast, the severity of the distal neurological deficit, the duration of the acute illness, a late dissociation between the cells and proteins C.S.F., the age and sex were all statistically significant prognostic factors.

Acute Disease↗
PubMed1978

Growth characteristics in vitro of hybrids between normal and transformed cell lines.

Sensitivity to the inhibition of division during cell crowding in vitro was determined for hybrids between normal and tumor cell populations of human and mouse origin. Interspecies hybrids were more sensitive to cell crowding than intraspecies hybrids. The results suggest that the inhibition of cell division due to crowding was more dependent upon the species of origin rather than on the normal or transformed character of the parental cell lines of the hybrid cell populations.

Animals↗