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D J Halley

Publications and source records attributed to D J Halley.

96 records · Page 6Linked to original sources
PubMed1980

Comparison of the alpha-mannosidases in fibroblast cultures from patients with mannosidosis and mucolipidosis II and from controls.

The intracellular and extracellular acidic alpha-mannosidase in cultures of fibroblasts from mucolipidosis-II patients has normal kinetics. The extracellular activity in cultures of cells from mannosidosis patients is normal, but a mutant enzyme is associated with the cell surface and intracellular fraction. The results support the involvement of membrane cycling and recognition markers in lysosomal enzyme localization.

Cells, Cultured↗
PubMed1980

Correction of I-cell defect by hybridization with lysosomal enzyme deficient human fibroblasts.

I-cell fibroblasts with a multiple intracellular lysosomal enzyme deficiency were hybridized with cells from patients with different types of single lysosomal enzyme defects. Fusion with G(M2) gangliosidosis, type 2, (Sandhoff disease) fibroblasts resulted in a restoration of the hexosaminidase activity, in a normalization of the electrophoretic mobility of the isoenzymes, and in a decreased activity in the medium. Fusion of I-cells with fibroblasts from G(M1) gangliosidosis, type 1, led to enhancement of beta-galactosidase (beta-gal) activity. This complementation must be the result of the presence of normal polypeptide chains in I-cells, whereas the other cell types provide a factor that causes the intracellular retention of the enzymes. Restoration of beta-gal was also observed in heterokaryons after fusion of I-cells with beta-galactosidase/neuraminidase-deficient (beta-gal(-)/neur(-)) variants, indicating that the neuraminidase(s) and the posttranslational modification of beta-gal are affected in a different way in I-cell disease and in beta-gal(-)/neur(-) variants. Fusion of I-cells with mannosidosis fibroblasts resulted in a restoration of the acidic form of alpha-mannosidase and in a decrease of the extracellular activity of both this enzyme and the hexosaminidase enzyme, indicating that fusion of I-cells with different types of fibroblasts with a single lysosomal enzyme deficiency not only leads to complementation for one particular enzyme but also to a correction of the basic defect in I-cells.

Cell Fusion↗
PubMed1979

Prenatal diagnosis of xeroderma pigmentosum (group C) using assays of unscheduled DNA synthesis and postreplication repair.

The analysis of DNA repair processes is described in two pregnancies at risk for xeroderma pigmentosum. In both cases, excision repair (measured by unscheduled DNA synthesis) and postreplication repair were analyzed. An affected and an unaffected fetus were identified within 3 weeks after amniocentesis. The cells from the affected fetus were found to be deficient in excision DNA repair, whereas the PRR patterns were intermediate between those of normal and PRR deficient cells. This indicates the possibility of prenatal diagnosis of PRR deficient XP patients (XP variants).

Amniotic Fluid↗
PubMedDate not supplied

Intragenic probe used for diagnostics in fragile X families.

The intragenic (FMR-1) probe pE5.1 was used for DNA analysis in fragile X families. With this probe fragments of altered size can be detected in female carriers, affected individuals and transmitting males. The length of the altered fragments was found to vary from one generation to another as well as between sibs. This instability of the DNA detected by pE5.1 was also seen in peripheral blood within single individuals. These phenomena are illustrated by 4 exemplary families segregating the fragile X syndrome. We demonstrate the diagnostic contribution of intragenic analysis to carrier detection as well as the identification of normal transmitting males carrying premutations. One of the families illustrates the passage of a premutation to a male through 2 generations.

DNA↗