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C Remy

Publications and source records attributed to C Remy.

At least 19 recordsLinked to original sources
PubMed1991

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↗
PubMed1990

[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↗
PubMed1990

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↗
PubMed1989

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↗
PubMed1989

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↗
PubMed1989

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↗
PubMed1987

[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↗
PubMed1976

Serum digoxin levels in patients of a general practice in Germany.

Serum digoxin levels were determined in 33 outpatients of a general practice in the countryside, on three occasions at intervals of 8 weeks. All the patients were on long term digoxin treatment, about 2 years on average. About 14 days after the first and the second visits the results of the measurements were sent to the patients, with a comment about their reliability in taking treatment according to the serum digoxin level. At the first visit half of the serum digoxin level were lower than 0.5 ng/ml; the mean serum concentration was 0.52 ng/ml. There was no correlation between serum concentration and age, dose or creatinine level; but there was with replies to the question about regularity of drug intake. The mean serum level at the second and the third visits was 0.88 ng/ml and 0.89 ng/ml, respectively. A correlation was found between the dose and the serum digoxin level. From these results it seems that compliance by the patient plays a major role in producing steady state levels of drugs.

Aged↗
PubMedDate not supplied

Two-dimensional 1H spectroscopic imaging for evaluating the local metabolic response to focal ischemia in the conscious rat.

Two-dimensional 1H spectroscopic imaging and magnetic resonance imaging were used to study focal ischemia induced by middle cerebral artery occlusion in rats. A water suppressing spin-echo sequence was used at 4.7 T. Phase encoding during the spin-echo delay (TE = 272 ms) yielded an 8 x 8 array of 35 microL voxels. The injured area of the brain had a higher lactate level and markedly lower N-acetyl aspartate, creatine and choline levels than did the non-ischemic regions. The spectroscopic imaging data clearly showed the localization of the infarct, which agreed well with both magnetic resonance imaging and the histological data obtained post-mortem. This study demonstrates the potential usefulness of combining magnetic resonance imaging and 1H spectroscopic imaging for studying animal models of stroke, and indicates the suitability of the technique for further pharmacological approaches.

Animals↗
PubMedDate not supplied

Intrarectal diazepam in epileptic adults.

Intrarectally (i.r.) administered diazepam (DZP) solution at doses of 20 and 30 mg in the treatment of serial seizures was studied in 39 adult patients with refractory partial epilepsy. Patients were randomly distributed into two groups (20 mg, n = 21; 30 mg, n = 18). Plasma levels of DZP were assessed over 24 h following i.r. injection. The efficacy of i.r. DZP in the treatment of serial seizures in adults was confirmed; onset of effect was noted approximately 10 min after the injection, and the effective dose was 0.50 mg/kg. Tolerance and acceptability were good. Intrarectal injection of DZP can be performed even by unskilled personnel and may be recommended in patients with serial seizures in the hope of preventing development of status epilepticus.

Administration, Rectal↗