Biomedical subjects
Publications and source records attributed to S Warter.
More precise localisations of the glutamate dehydrogenase gene (GLUD) to chromosome 10q23 and of the pseudogene GLUDP1 to X q24 are proposed.
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The karyotypes of three Lepilemuridae species, Lepilemur mustelinus, L. edwardsi, and L. dorsalis, are described and compared to those of three Lepilemur species previously reported. The phylogenetic relationships between the six species and their presumed last common ancestor are given. The results obtained, and the comparison with other groups, strongly suggest a monophyletic origin for all Malagasy lemurs.
The karyotypes of three Lepilemuridae species, Lepilemur ruficaudatus, L leucopus, and L septentrionalis, are described and compared. An almost complete analogy of chromosome banding is exhibited. Several complex chromosomal rearrangements, especially end-to-end translocations, have occurred in the evolution of these species. The chromosomal data indicate that the species studied are well separated. In addition, their common chromosomal characters show that they constitute a clearly distinct family among the lemurs.
A cytogenetic study was carried out of several Lemur hybrids and their progeny. The effects of Robertsonian translocations in the heterozygous state on fertility and the possibility of a preferential transmission of metacentric trivalents are debated.
A chromosomal banding study was carried out on Propithecus verreauxi verreauxi, P. verreauxi deckeni, and Avahi laniger laniger. Comparison of their karyotypes with those of Microcebus murinus and Lemur fulvus led to reconstruction of the ancestral Lemuriform karyotype and a determination that the branch leading to the Indridae was isolated very early, before the separation of the Lemuridae from the Cheirogaleidae. The karyotype of Avahi remained highly ancestral, whereas that of P. verreauxi was considerably modified, chiefly by Robersonian translocations.
The karyotype, comprised of 62 chromosomes, of Galago crassicaudatus is described. It is compared to the karyotype of Galago senegalensis and to that of the presumed common ancestor to Lorisiforms, previously reconstructed. Most of the reconstructed chromosomes were found, unmodified, in G. crassicaudatus, strengthening the validity of the reconstruction.
The karyotype of four Galagidae (Galago senegalensis, G. demidovii, G. alleni and Euoticus elegantulus) are studied and compared with the aid of various banding techniques. Many common chromosome segments were found, and it was possible to reconstruct a hypothetical ancestral karyotype for the family. It was also possible to show the relation between the chromosomes of Galagidae with those of two Lorisidae. The general scheme of chromosomal evolution of the Lorisiforms can be proposed, resulting from a common populational evolution followed by an accumulation of translocations, mostly of the Robertsonian type. Several pericentric inversions have also occurred in the trunk of the Lorisidae, emerging from this common population. Then, Galagidae have evolved, each species independently, by an accumulation of translocations, mostly Robertsonian, whereas Lorisidae have accumulated pericentric inversions prior diverging.
A new, clinically and biochemically atypical case of Lesch-Nyhan syndrome is presented. There is mild neurological involvement, the APRTase activity is normal, despite a raised PRPP concentration and HGPRTase activity is low. The optimal pH and temperature of fibroblast HGPRTase activity differ markedly from control values. The Km for hypoxanthine and PRPP are minimally changed. Erythrocyte HGPRTase activity does not vary following adenine ingestion in either the adult patient or the control. Fibroblast HGPRTase activity is not affected by the addition of adenine to cultures of fibroblasts. However, in the child suffering from classical Lesch-Nyhan syndrome, erythrocyte HGPRTase activity decreases following adenine ingestion.
A cytogenetic study of Macaca tonkeana shows that this species has a karyotype identical with that of Macaca fascicularis although there are sufficient morphological and ecoethological differences for the taxidermists to place these animals into two different species.
29 cases out of 153 men who come for primary sterility with no history of previous abortions showed a chromosome abnormality. These chromosome abnormalities were found associated with teratospermia, in the case of autosome translocations, affecting above all the head of the spermatozoid. The interrelationship of sterility with chromosome abnormalities and teratospermia is discussed.
This report brings to light the results of cytogenetic study carried out on 350 mentally retarded persons (medium: Group I, deep Group II). In 8,2% and 12,56% of the cases a chromosomic abnormality is observed (mainly trisomy 21). These percentages are in correlation with the results of other studies. Ante and peri natal pathology plays a very important part among exogenous factors. In numerous cases a multifactors etiology can be found as the cause of this mental retardation, the effect of an initial organic mental retardation being aggravated by precocious affective perturbations. For those cases without apparent etiology, a teratologic origin may be thought as their cause.
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We describe a case of (2) (q34;q36) deletion in a girl. The main clinical features of the proband are staturo-ponderal retardation, skull-face dysmorphia and an interauricular communication. The relationship between morphological and chromosomal abnormalities is discussed.
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Several neuroblastoma clones and the same clones adapted to proliferation in a medium containing 15 mug/ml of 8-azaguanine and 6-thioguanine are characterized with respect to their morphology, acetylcholinesterase activity, catecholamine content and chromosomal pattern. Interclonal as well as intraclonal heterogeneity was found for the cell parameters studied. A reduction in the number of catecholamine-containing cells was observed in the azaguanine and thioguanine resistant adrenergic (M1, N115) cells compared with their parental lines. An increase of choline acetyltransferase activity was found in the M5 cholinergic clone, and a decrease of the same activity in the S21 cholinergic line selected in the medium with the purine analogues. Furthermore, a striking change in the distribution of chromosomes and chromosomal markers appeared in the resistant cells of all clones.