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Biomedical subjects

J M Dupont

Publications and source records attributed to J M Dupont.

28 records · Page 2Linked to original sources
PubMedDate not supplied

Neuropharmacological study of aged MAM-treated rats.

After evaluation of activity in an open field, norepinephrine (NE), serotonin (5HT), 5-hydroxyindolacetic acid (5HIAA), homovanillic acid (HVA), and choline acetyltransferase (CAT) were investigated in cortex of 26-month-old rats poisoned with methylazoxymethanol (MAM) as compared to control rats of the same age. NE and 5HT concentrations showed a marked increase, but levels were normal when expressed as total content, just as in MAM-exposed young adults. Concentrations of 5HIAA were also increased but to a lesser extent than 5 HT. Aged MAM rats did not show any modification of spontaneous activity although hyperactivity is characteristic of young adults exposed to MAM. Together with this behavioral observation, a significant decrease in total HVA content was measured. Because HVA levels seem correlated with activity in MAM-exposed rats, we speculate that the behavioral abnormality recovers in old age. Total CAT activity was also reduced. These results indicate that the neurochemical pattern of young adult MAM-poisoned rats is conserved in aged rats except for some changes in the dopaminergic and cholinergic systems.

Aging↗
PubMedDate not supplied

Heteromorphism 18ph+ : with or without reproductive consequences?

Heteromorphism or chromosomal variants are usually attributed to structural variations in constitutive heterochromatin. In the case of chromosome 18, 25 cases of 18ph+ have been reported to date. Using the Primed In Situ Labelling technique (PRINS) to study 2 new cases of 18ph+, we have been able to confirm their molecular nature and assuming a mechanism of formation. Although such chromosomal variants are usually thought to have no adverse clinical consequence, a review of the literature shows that many cases were diagnosed because of recurrent abortion, malformed or mentally retarded children suggesting the possible relationship between 18ph+ and such clinical outcomes.

Amniotic Fluid↗
PubMedDate not supplied

French multi-centric study of 2000 amniotic fluid interphase FISH analyses from high-risk pregnancies and review of the literature.

This prospective and multi-centric study confirms the accuracy and the limitations of interphase FISH and shows that any cytogenetics laboratory can perform this technique. With regard to the technical approach, we think that slides must be examined by two investigators, because the scoring may be subjective. The main problem with the AneuVysion kit concerns the alpha satellite probes, and especially the chromosome 18 probe, which is sometimes very difficult to interpret because of the high variability of the size of the spots, and this may lead to false negative and uninformative cases. The best solution would be to replace these probes by locus-specific probes. Concerning clinical management, we offer interphase FISH only in very high-risk pregnancies or/and at late gestational age because of the cost of the test. We think that an aberrant FISH result can be used for a clinical decision when it is associated with a corresponding abnormal ultrasound scan. In other cases, most of the time, we prefer to wait for the standard karyotype.

Adult↗
PubMedDate not supplied

Mosaic isochromosome 20q and normal outcome: a new case ascertained by fluorescence in situ hybridization and a review of the literature.

We describe a new case of mosaic isochromosome 20q revealed by amniocentesis. A 46,XX/46,XX,i(20q) chromosomic complement was indirectly confirmed by fluorescent in situ hybridization. Since control chromosome analysis performed on cord blood showed a normal karyotype, pregnancy was continued and resulted in the birth of a normal female infant.

Adult↗
PubMedDate not supplied

Experimental evidence of a potentiation by alpha,beta magnesium L-aspartate of the anxiolytic effect of diazepam. Four-plate test in mice and qEEG study in primates.

The anxiolytic dose 50 (AD50) of diazepam was determined in mice in the four-plate test and the EEG pattern elicited by diazepam was quantified by Fast Fourier Transformation in monkeys. The AD50 of diazepam was reduced by 2.7-fold after repeated treatment with alpha,beta magnesium L-aspartate. The increased EEG fast activity elicited by diazepam at the expense of slow activities was reinforced and more long lasting after alpha,beta magnesium L-aspartate treatment.

Animals↗
PubMedDate not supplied

[Arsenic and respiratory neoplasms, risks, prevention].

Arsine and in general airborne arsenic compounds show the main cancer promoting characteristics. Protection of employees is therefore a question of ventilation speed and arsenic determination in ambient air and, preservated with EDTA, in urine. Meanwhile, the excess of respiratory cancers alone will continue to increase 5% for each microgram of arsenic present per m3 of air breathed in the work area, or excreted in every one-third liter of urine. Eighteen years after occupational lung cancer due to arsenic and arsenic compounds has been recognised in Japan, the presently accepted TLV of arsine, 200 micrograms/m3, unchanged since 1950, thus corresponds to an excess mortality of 1000%.

Arsenic↗