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Biomedical subjects

N Van Cong

Publications and source records attributed to N Van Cong.

44 records · Page 3Linked to original sources
PubMed1975

[Genetic study of GM2 gangliosidosis (Tay-Sachs and Sandhoff) by the study of the hexosaminidases of the Sandhoff-rodents hybrids (mouse and hamster)].

The electrophoretic pattern of human fibroblast extracts displays three bands (cathode to anode) of hexosaminidase: Hex B, Hex A, Hex C in normal strains, only one B band in Tay-Sachs strains, and only one C band in Sandhoff strains. The author's observations on rodent-Sandhoff cellular hybrids agree with the hypothesis made by others: Hex B = (beta beta)n; Hex A = (alpha beta)n; and Hex B = (alpha alpha) n. The mutation occurred in the alpha chain in Tay-Sachs disease and in the beta chain in Sandhoff disease. When mannose phosphate isomerase (MPI) is present, and therefore Hex C because of the well known MPI - Hex C synteny, a new hexosaminidase band called "Hex A fast" is seen in Sandhoff-hamster hybrids, while a "Hex A like" band is seen in Sandhoff-mouse hybrids. Both bands are absent from parental cells. It is suggested that "Hex A fast" and "Hex A like" are human-rodent hybrid hexosaminidases: "Hex A fast" = (alpha beta')n; "Hex A like" = (alpha beta's)n with the assumption that hamster HB' = (beta' beta')n and mouse Hex B'S = (beta's beta's)n. The specific anti Hex A = anti (alpha beta); the non-specific anti Hex A = anti Hex B = anti (beta); the anti (alpha) would be absent or weak. This explains the reactivity of the anti-Hex A against Hex A and Hex B, but not against Hex C.

Animals↗
PubMedDate not supplied

A polymorphic DNA marker linked to cystic fibrosis is located on chromosome 7.

Although cystic fibrosis (CF) is among the most common inherited diseases in Caucasian populations, the basic biochemical defect is not yet known. CF is inherited as an autosomal recessive trait apparently due to mutations in a single gene, whence the efforts made to identify the genetic locus responsible by linkage studies. Two markers have recently been identified that are genetically linked to CF: one is a genetic variation in serum level of activity of the enzyme paraoxonase, and the other is a restriction fragment length polymorphism (RFLP) identified with a randomly isolated DNA probe. We report here that the genetic locus DOCRI-917 defined by the cloned DNA probe is located on chromosome 7.

Chromosome Mapping↗
PubMedDate not supplied

[Genetic control of hexosaminidases].

The authors present the results they obtained which interspecific cell hybrids. The hexosaminidases A, B and C, seem to be under the control of the two genes alpha and beta, B and CS constituing homopolymers (beta beta)n and (alpha alpha)n, A being a heteropolymer (alpha beta)n. The isozyme CF, particularly abundant in fetal tissues and found also in Tay-Sachs by some authors is, in all probability, under independent genetic control.

Animals↗