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Biomedical subjects

C Junien

Publications and source records attributed to C Junien.

197 records · Page 11Linked to original sources
PubMed1978

[Gene dosage and chromosome enzymatic markers].

Data are tabulated on the number of nomenclature current abbreviations, the occurence of multiple gene loci and corresponding polypeptide chains, and chromosomal assignment of 114 enzymes. Gene dose effect measurement is dependent upon several properties of the enzyme which are also listed: tissue and subcellular distribution, subunit number, interloci hybrids, genetic polymorphism, qualitative and quantitative methods of detection. The possibilities and limits of the concept of a gene-dose relationship, for the detection of carriers of chromosomal aberrations, and also for chromosomal assignment are discussed.

Chromosome Mapping↗
PubMed1978

[Assessment of the myocardial infarct size and kinetic study of the necrosis process by serial determinations of creatine kinase].

Assessment of the size of a myocardial infarct is important from a prognostic point of view, given the opportunities for surgical and pharmacological limitation of the process of necrosis. Serial doses of creatine kinase and its isoenzyme MB given every 4 hours for the first 48 hours of the infarct have allowed us to estimate the size of the infarct and to study the kinetics of enzyme liberation during necrosis. Unknown factors limit the sensitivity of this means of assessing the size of an infarct. The kinetic study showed that the enzyme is liberated by differing mechanisms.

Creatine Kinase↗
PubMed1977

12pter to 12p12.2: possible assignment of human triose phosphate isomerase.

Red cell triose-phosphate isomerase (TPI) was determined, together with other enzymes, in three patients with chromosome 12 abnormalities. In patient No. 1 (trisomy of the segment 12 pter leads to 12q 12) and in patient No. 2 (trisomy of the segment 12pter leads to 12p 12.1), the TPI activity was significantly increased. In patient No. 3 (deletion of the segment 12 p 11 leads to 12 p 12.2), the TPI activity was in the normal range. These results suggest that the human TPI locus is located on the chromosome 12 short arm, between 12p ter and 12 p 12.2.

Carbohydrate Epimerases↗
PubMed1977

[Generalized saturnine paralysis. Discovery of a double congenital disease: glucose-6-phosphate dehydrogenase deficiency (new variant) and distal tubular acidosis].

A case of severe lead poisoning with haemolytic anemia, extensive polyneuropathy and arterial hypertension is reported in a patient for whom G-6-P-D deficiency and renal tubular acidosis were discovered. Both traits were present in his family. Incomplete regression of paralysis and persistant biological abnormalities after chelating treatment were demonstrative of heavy saturnine load even though the toxic exposure was brief. The role of the two deficiencies in the mechanism of intoxication is discussed: facilitation of haemolysis by enzymopathy and bone lead redistribution resulting from osteolysis probably due to the tubulopathy. The authors emphasize the fact that thorough and serial biological investigation is essential in the discovery of factors which may precipitate lead poisoning, as well as in the determination of follow-up criteria of efficient toxic epuration with sufficient delay. Typing of the enzyme has led to the identification of a new variant of glucose-6-phosphate dehydrogenase deficiency.

Acidosis, Renal Tubular↗
PubMed1976

Gene dosage effect in human triploid fibroblasts.

The activity of 13 cytoplasmic enzymes has been determined in fibroblast extracts from 9 triploid and 13 control lines. The results show a high activity for 2 X-linked enzymes, glucose 6-phosphate dehydrogenase and phosphoglycerate kinase. These data, together with cytogenetic observations, support the contention that 2 X chromosomes were active in the triploid lines.

Fibroblasts↗
PubMed1976

Congenital enzymopenic methaemoglobinaemia. Clinical and biochemical study of a family with three homozygotes.

Three brothers with congenital recessive methaemoglobinaemia without mental retardation were found to be homozygous for NADH diaphorase deficiency. Twelve family members were heterozygous. One of the probands had marked digital clubbing, an unusual feature in this disease. In the probands, the red-cell NADH diaphorase was very low and unstable, whereas in the leucocytes this enzyme was present at a normal level. Isoelectric focusing of haemoglobin in the three probands showed that the alpha-chain was preferentially oxidized spontaneously. This confirms the greater oxidizability of this chain, as already described on isolated chains.

Adolescent↗
PubMed1976

[Localization of the gene of the glyceraldehyde 3 phosphate dehydrogenase on the distal segment of the short arm of the chromosome 12].

The enzymatic activity of G3PD and LDH-B in erythrocytes has been assayed in three patients carrying a rearrangement of the short arm of chromosome 12. The first patient is trisomic for the whole short arm. The second is trisomic only for the distal part and the third is monosomic for the proximal part. G3PD: Activity increased in patients 1 and 2 and normal in patient 3. LDH-B: Activity increased in patients 1 and 2 and decreased in patient 3. From these observations it is concluded that the erythrocytic G3PD locus is localized on the distal part of 12p, between 12p12.2 and 12 pter, and that LDH-B locus is on the middle third between 12p12.1 and 12p12.2

Child, Preschool↗
PubMed1975

[Increase of the LDH-B activity in a boy with 12p trisomy by malsegregation of a maternal translocation t(12;14) (q12;p11)].

A newborn male trisomic for 12p is compared with three other 12p trisomics already reported in the literature, as well as with three patients monosomic for 12p. A "type and countertype" opposition is observed for five characters: in the trisomy, turricephaly, shortness of the nose, protruding anthelix, wide palms, and increased LDH-B activity; in the monosomy, protruding occiput, large nose, hypoplasia of the anthelix, narrow palms, and decreased LDH-B activity.

Abnormalities, Multiple↗
PubMedDate not supplied

Myotonic dystrophy: over-expression or/and under-expression? A critical review on a controversial point.

Myotonic dystrophy (DM) results from the amplification of an unstable (CTG)n sequence in the 3' untranslated region of the myotonin-protein kinase (MT-PK) gene. The expression of the enlarged allele in DM patients with a number of repeats below or beyond 200, was analysed by three different groups. Two groups showed a decreased or absent expression of mutant alleles in DM adults, in congenitally affected infants (CDM) and in an affected fetus. On the contrary, another group reported the increased expression of the mutated allele in several tissues of a CDM infant. These discrepancies may be explained by the different methods used, the small number of patients, the individuals and tissues used as controls, or reflect the use of primers located in different regions of the MT-PK gene.

Adult↗
PubMedDate not supplied

c-Ha-ras1 is not deleted in aniridia-Wilms' tumour association.

Non-random tumour-specific chromosomal abnormalities have been observed in cells of many different human tumours. In Wilms' tumour (WT) and retinoblastoma, a chromosomal deletion occurs germinally or somatically and has been considered an important step in tumour development. One class of potential cellular transforming genes comprises the cellular homologues of the transforming genes of highly oncogenic retroviruses. A remarkable concordance between the chromosomal location of human cellular oncogenes and the breakpoints involved in acquired chromosomal translocations is becoming apparent in various cancers: the oncogenes c-mos, c-myc and c-abl are located at the breakpoints that occur in acute myeloblastic leukaemia, Burkitt's lymphoma and chronic myelocytic leukaemia respectively. Thus when the oncogene c-Ha-ras1 was localized to the short arm of human chromosome 11 (refs 6-8; region 11p11 leads to p15 and not 11p13 as stated in ref. 5), it was proposed as a possible aetiological agent in the aniridia-WT association (AWTA) that results from a deletion of 11p13 (although a transforming gene recently isolated from a WT cell line (G401) was shown not to be homologous to either c-Ha-ras or c-Ki-ras9). We have now looked for deletion or rearrangement of c-Ha-ras1 in the DNA from four subjects with del(11p13)-associated predisposition to Wilms' tumour, aniridia, genitourinary abnormalities and mental retardation. We report here that in no case is c-Ha-ras1 deleted, and we have further refined its location to 11p15.1 leads to 11p15.5. On the basis of enzyme studies and direct gene dosage determination for c-Ha-ras1 and beta-globin in neoplastic and non-neoplastic tissues from one patient, we conclude that deletion of the normal counterpart of 11p cannot account for the development of the tumour.

Child, Preschool↗
PubMedDate not supplied

Analysis of deletions in DNA from patients with Becker and Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is an X-linked recessive genetic disorder for which the biochemical defect is as yet unknown. Recently, two cloned segments of human X-chromosome DNA have been described which detect structural alterations within or near the genetic locus responsible for the disorder. Both of these cloned segments were described as tightly linked to the locus and were capable of detecting deletions in the DNA of boys affected with DMD. In an attempt to determine more precisely the occurrence of these deletions within a large population of DMD patients and the accuracy of one of the segments, DXS164 (pERT87), in determining the inheritance of the DMD X chromosome, the subclones 1, 8 and 15 were made available to many investigators throughout the world. Here we describe the combined results of more than 20 research laboratories with respect to the occurrence of deletions at the DXS164 locus in DNA samples isolated from patients with DMD and Becker muscular dystrophy (BMD). The results indicate that the DXS164 locus apparently recombines with DMD 5% of the time, but is probably located between independent sites of mutation which yield DMD. The breakpoints of some deletions are delineated within the DXS164 locus, and it is evident that the deletions at the DMD locus are frequent and extremely large.

Chromosome Deletion↗