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Biomedical subjects

C Remy

Publications and source records attributed to C Remy.

At least 37 records · Page 2Linked to original sources

[Self concept and need for social approval in bulimia patients].

The present work concerns the relation between the need for social approval (assessed as social desirability) and bulimia with respect to gender-differences. Since bulimia is mainly a female issue, a relationship was predicted between the development of bulimia and the internalization of a socially desired feminine sex-stereotype with respect to the self-concept. The need for approval was assessed for male subjects, female subjects not suffering from eating-disorders, and female bulimic subjects. The results show that bulimic women have significant higher self-ratings concerning the need for approval. Without neglecting multicausal explications, the results suggest that social desirability as an expression of social approval should receive more attention as a facilitating factor in the development of bulimia.

Adult↗

[Nocturnal hypoglycemia in insulin-dependent diabetics].

OBJECTIVES: Repeated hypoglycaemia has been reported to impair recognition of subsequent hypoglycaemia with a high risk of severe hypoglycaemia. This intensified insulin therapy may be dangerous in insulin-dependent diabetes mellitus (IDDM) patients with unawareness of hypoglycaemia. METHODS: We assessed the incidence of nocturnal hypoglycaemia and the benefit of an additional bedtime snack in IDDM patients treated by 2 or 3 daily injections. Capillary blood glucose was measured by finger strip at 10 p.m. and plasma venous glycaemia was determined at 0, 2, 4 and 8 a.m. RESULTS: The study was composed of two phases. In the first phase, patients (n = 93) did not receive any snack at bedtime. Blood glucose fell to 2.75 mmol/l or less in 33%. Among the 40 patients with a 10 p.m. glycaemia of 9 mmol/l or less, 57.5% experienced nocturnal hypoglycaemia vs 15% of the 53 others. The second phase concerned 106 IDD patients. An additional bedtime snack was given when 10 p.m. blood glucose was 9 mmol/l or less. The incidence of hypoglycaemia fell to 32% (14 of 44 IDDM) i.e. a significant benefit of 44% (p < 0.01). However patients who received this additional bedtime snack had a slightly higher 8 a.m. glycaemia than those with 10 p.m. glycaemia at 9 mmol/l or less during the first phase (9.61 +/- 5.67 mmol/l vs 7.75 +/- 4.30 mmol/l) but this result is not significant. CONCLUSION: Prevention of nocturnal hypoglycaemia may be achieved in IDDM patients by bedtime glucose determination and an additional snack when glycaemia is 9 mmol/l or less.

Adult↗

Prolactin and growth hormone mRNA and protein characterization in SMtTW rat pituitary tumours.

We have combined different techniques to analyse passages of five different rat spontaneous pituitary tumours (SMtTW) that were transplanted under the kidney capsule. These tumours were secreting prolactin (PRL), GH or both hormones. RIA, immunocytochemistry (ICC) and Western blot analysis were applied to characterize the hormone(s) stored (ICC and Western blot) and secreted (RIA). mRNA content was analysed by PCR, Northern blot analysis and in situ hybridization. The data point not only to the reliability of the techniques used at both protein and RNA levels for each tumour studied but also to the complementarity of some techniques. For example, whereas Northern blot analysis demonstrates the presence and size of hormone mRNA, in situ hybridization indicates the percentage of cells expressing a given hormone mRNA and allows the presence of one population (or more) of cells in a given tumour to be identified. Moreover, the tumours were compared with normal rat pituitary. Although the PRL and GH mRNAs were identical in size, the amount of mRNA was lower in the tumours. At the protein level, the PRL and GH variants exhibited a different pattern of expression in tumours compared with the normal rat pituitary. The biological significance of these differences is discussed.

Animals↗

Clobazam in the treatment of epilepsy: a review of the literature.

The literature was reviewed to define the role of clobazam (CLB) in the treatment of epilepsy. CLB is an effective antiepileptic drug (AED) in most varieties of seizures and epilepsies for both short-term and long-term treatment. Tolerability of CLB is satisfactory, better than for conventional benzodiazepines. CLB has no significant interaction with other drugs. Tolerance may develop, but this aspect may have been overemphasized: a long-term benefit figure of 28% can be expected without tolerance. When CLB maintains efficacy, patients continue to benefit for years without drug dependence or unwanted side effects. CLB appears to be a useful treatment for epilepsy as intermittent or short-term add-on therapy; but it should also be tried as long-term therapy in some situations, especially as add-on therapy for patients with refractory epilepsy, as add-on or monotherapy for patients with anxiety, or in some women in association with oral contraceptives.

Anti-Anxiety Agents↗

Development of an enzyme immunoassay for arginine-vasopressin (AVP)-like insect diuretic hormone.

1. The AVP-like insect diuretic hormone is a biologically active antiparallel dimer present, along with its non-active monomeric form (Cys-Leu-Ile-Thr-Asn-Cys-Pro-Arg-GlyNH2), in the African locust. 2. It exhibits diuretic activity by increasing fluid excretion at the level of the Malpighian tubules. 3. To date, both monomer and dimer have been assayed using a radioimmunoassay originally prepared for mammalian AVP. 4. We have developed here an original enzyme immunoassay based on the use of antibodies to insect AVP-like raised in rabbits against synthetic monomers and dimers, using acetylcholinesterase conjugate as an enzymatic tracer. 5. This enzyme immunoassay enables measurement of the dimer to be made with adequate sensitivity (0.3 nmol/l, i.e. 21 pg/well) and reproducibility while sensitivity of the monomer is somewhat lower (14 nmol/l, i.e. 480 pg/well). 6. The assay was validated by assaying native dimer and monomer throughout the different steps of purification (from a crude extract to reversed-phase liquid chromatographic fractions). 7. A good correlation was observed between radioimmunoassays and enzyme immunoassays. 8. The enzyme immunoassay was also used to measure the level of AVP-like peptides in several insect tissues not explored to date.

Amino Acid Sequence↗

Proton spectroscopic imaging: a tool for studying intracerebral tumor models in rat.

Water-suppressed 2D 1H spectroscopic imaging was used with surface coils to study in vivo the cerebral metabolism changes in rat brain induced by a glial tumor growing in situ. To achieve slice selection without a chemical-shift artifact, we exploited the depth pulse properties of a spin-echo sequence. In order to give a spectral response which is independent of the position, the water suppression was achieved by using a spin-locking excitation and a binomial refocusing pulse. Spectroscopic images were obtained with an in-plane resolution of 1.1 X 1.1 mm and a slice thickness of roughly 3 mm. The growing of the tumor induced dramatic modifications in the proton spectra, including a nearly complete loss of N-acetyl aspartate, an increase of the 1.3-ppm peak, an increase in choline, and a decrease in creatine. The results demonstrate the potential of spectroscopic imaging in the study of intracranial tumor models in rats.

Animals↗

[Comparative open trial of carbamazepine and slow-release carbamazepine in epilepsy in adults].

A multicentre open therapeutic trial comparing carbamazepine with slow-release carbamazepine was conducted in 114 epileptic patients older than 12 years. The patients received the two products successively during two periods of 1 month each. With slow-release carbamazepine the number of doses could be reduced to 2 per day without decrease in effectiveness and with less side-effects. The twice-a-day dosage should result in better compliance and consequently in a better quality of treatment in the long term.

Adolescent↗

Failure to detect viral genomic sequences of three viruses (herpes simplex, simian virus 40 and adenovirus) in human and rat brain tumors.

Little is known about oncogenesis in brain tumors. Viruses are thought to be involved in some neurological diseases, the presence of subfractions of viral DNA has been reported in various circumstances and the oncogenicity of some viruses has been demonstrated in animal experiments. The discovery of homologies between retroviral oncogenes and normal cellular genes (proto-oncogenes) has stimulated once again the search for viral responsibility in oncogenesis. Having a large bank of tumor material available, we systematically examined 39 brain tumors using Southern blot hybridization with DNAs of three viruses, known to be involved in neurological diseases: herpes simplex virus (HSV), simian virus 40 (SV40) and adenovirus type 2 (Ad2). We detected no homology between the DNAs of the examined material and the viral DNA probes. We compare these negative results with those of other published studies and discuss the experimental conditions, with special reference to the possibility of non-specific hybridization, which could account for the positive results reported. The present negative results could be interpreted either as absence of involvement of the three investigated viruses in brain tumor oncogenesis, or an indirect involvement through a hit-and-run mechanism or a highly dispersed state of the viral sequences among the host genome, which would prevent hybridization with the probe, as it has been supposed to be the case during the latency phase of herpes virus.

Adenoviridae↗

In vivo 1H NMR spectroscopy of an intracerebral glioma in the rat.

High-resolution 1H surface coil NMR spectroscopy (MRS) was used to evaluate in vivo the cerebral metabolism changes in rat brain induced by a glial tumor growing in situ. Tumor cells (C6 glioma cells) were stereotaxically placed in the right hemisphere superficially. 1H MRS was performed using 5-mm surface coils implanted over the right hemisphere and the water was suppressed using a binomial sequence. As the intracerebral tumor size increased, there was a marked decrease in the N-acetyl aspartate level and an increase in the 1.3 ppm peak. Edition of this peak showed that lactate increased but lipids increased much more than lactate. Moreover the ratio between the choline-phosphocholine and creatine-phosphocreatine peaks changed. This study demonstrates that high-resolution surface coil 1H MRS can be used to monitor changes in metabolism associated with growth of an experimentally induced rat brain tumor in situ.

Animals↗

High-flux signals and spatial localization in high-resolution 1H spectroscopy with surface coils.

To perform in vivo localized proton spectroscopy with water suppression, spin-echo sequences, made of binomial pulses, are commonly used with surface coils. The frequency selective response to such a sequence is also-spatially dependent, that is dependent on the sample shape and on the pulse angle adjustment. It is consequently pointed out in this paper that quantitative analysis for relative peak intensities may be strongly affected by the contribution of the high-flux regions. In vivo proton spectroscopy of rat brain exemplifies this difficulty. It is shown that the use of selective prepulses to suppress high-flux signals may be of poor efficiency depending on chemical shift, while the use of hard nonselective prepulses works for any chemical shift.

Animals↗

Limits of tumour treatment follow up by surface coil 31P magnetic resonance spectroscopy. The case of sarcosinamide-CNU treated ependymoblastoma.

Ependymoblastoma tumour bearing mice were treated with sarcosinamide-CNU and compared with untreated mice with regard to tumour growth, pathological examinations and levels of phosphorylated metabolites measured by in vivo nuclear magnetic resonance spectroscopy. The response to the drug was demonstrated by its effect on tumour growth and with pathological examinations. Spectra evolution was different from controls for only four treated tumours out of eight.

Animals↗

Efficacy and safety of vigabatrin in the long-term treatment of refractory epilepsy.

1. The long term safety and efficacy of vigabatrin has been studied in 254 patients with refractory epilepsy (82% with partial seizures) in 23 different clinics in eight European countries. 2. This was an open multicentre study in which patients who had experienced a significant benefit from vigabatrin and had continued to take the drug for 1 year or longer were eligible for evaluation. The mean duration of therapy in the 254 patients was 22.7 months; 72 patients received vigabatrin for more than 2 years. 3. Patients were severely affected by epilepsy with a median monthly seizure frequency of 15.7 despite taking an average of 2.2 antiepileptic drugs. On vigabatrin, the median seizure frequency was about 35% of baseline, remaining stable over time despite a 10% reduction in the number of concurrent medications. 4. The lack of tachyphylaxis to the antiepileptic effect of vigabatrin is shown by the small number of patients who discontinued for insufficient efficacy (11%), two thirds of them during the first 6 months of follow-up. Maintenance of efficacy is also clearly demonstrated by analysis of 2 year and 3 year cohorts of patients. 5. Clinical and biological tolerability was excellent. There was a very low rate of drop out for adverse events (1.6%). Adverse events, mainly sedation, irritation and weight gain were mostly mild and transient. 75% of patients reported no adverse event at all. 6. Safety evaluation included serial neurological, ophthalmological and general examinations: no new abnormal clinical feature or adverse event emerged with long term therapy.

Adolescent↗

In vivo 31P nuclear magnetic resonance studies of T1 and T2 relaxation times in rat brain and in rat brain tumors implanted to nude mice.

31P NMR spin-lattice (T1) and spin-spin (T2) relaxation times of phosphocreatine, ATP, inorganic phosphate, and phosphomonoesters have been measured in vivo at 4.7 T in rat brain and rat brain tumors implanted on nude mice. The relaxation data were acquired using a phase-cycled saturation-recovery spin-echo sequence. The problems associated with the phase modulation of the ATP lines by the homonuclear coupling constants were overcome by using selective refocusing pulses for the T2 measurements. In all the metabolites, large differences (1 to 2 orders of magnitude) are observed between the two relaxation times. T1 values in rat brain tumors are 30 to 90% longer than their counterparts in normal rat brain. T2 values follow the same trend with smaller variations except for phosphocreatine values which seem much less sensitive to the metabolic state of the tissues.

Animals↗

[Multiple correlative studies of stereotaxic biopsies of brain tumors].

The opportunity of having several samples at the same site which could be spatially localized allows an intensive exploitation of stereotactic biopsies of brain tumors: the pathological data may be correlated to other measures, performed at the same site (electrical impedance X ray absorption coefficient) or on other samples (NMR relaxation times, water content, nucleic acids). These samples are available for oncology experiments in cellular biology (cell cultures, grafts on nude mice) or in molecular biology (DNA and RNA hybridization with specific nucleic acid probes). We were therefore able: 1) to study the diagnostic homologies between pathology and histology examinations; 2) to show that T1 and T2 NMR relaxation times are 2 times longer in tumor tissues than in normal brain; 3) to show that the electrical impedance is decreased by a factor 2 in brain tumors; 4) to show the absence of integrated viral genomic sequences and the existence of oncogenes association patterns in brain tumors by hybridization of specific sequences; 5) to establish permanent cell lines, the tumorigenicity of which is assayed by grafting on nude mice. Therefore, stereotactic biopsies appear to be, provided they are intensively and rationally exploited, a major research tool in an area which remains unsensitive to the various therapeutic approaches.

Animals↗

31P nuclear magnetic resonance in vivo spectroscopy of the metabolic changes induced in the awake rat brain during KCN intoxication and its reversal by hydroxocobalamine.

Radiofrequency surface coils were chronically implanted in rats, which were subsequently subjected to 31P nuclear magnetic resonance (NMR) investigations at 4.7 T. The implanted coil allowed study of the animals without need for anesthesia, which is a prerequisite for studies of normal brain metabolism. The animals may be kept in the NMR probe for several hours. During subsequent experiments, they may be placed in the same position, therefore allowing follow-up studies for periods as long as 2 months. This method has been used in the study of sublethal KCN intoxication. KCN, a cytochrome c oxidase inhibitor, induces a blockade of cell respiratory processes, which is reflected, in a dose-dependent manner, by a decrease in phosphocreatine content and pH and an increase in inorganic phosphate content, whereas ATP levels remain constant until high doses of KCN (6 mg/kg i.p.) are reached. 31P NMR allows the time course of these metabolic changes to be followed. For high KCN doses, a new peak, termed X, is observed, which is interpreted as being due to a pool of inorganic phosphate at very low pH (5.65), corresponding to a subset of cells that did not survive KCN injury. Hydroxocobalamine, a specific antidote of KCN, suppresses the metabolic changes due to 6 mg/kg of KCN.

Animals↗