Biomedical subjects

J Wolstenholme

Publications and source records attributed to J Wolstenholme.

47 records · Page 3Linked to original sources

PubMed1983

Amylo-1,6-glucosidase activity in cultured cells: a deficiency in type III glycogenosis with prenatal studies.

Deficiency of amylo-1,6-glucosidase activity was expressed in parallel in liver and skin fibroblasts from a patient with type III glycogenosis. In crude extracts of control liver and muscle, amylo-1,6-glucosidase (M.W. 164000) was identified by immunoprecipitation; no cross-reacting material was found in the patient's liver. Assay of amylo-1,6-glucosidase activity in cultured skin fibroblasts from the affected family revealed less than 10 per cent of control value in mutant homozygous cells whereas in cells from the parents, activity was reduced to 40-60 per cent of the control value. Activity in cultured amniotic fluid cells was similar to that of control fibroblasts. In cultured amniotic fluid cells obtained during the mother's subsequent pregnancy, the normal amylo-1,6-glucosidase activity measured, predicted correctly the outcome of this pregnancy prior to the 20th week of gestation.

Amniotic Fluid↗

PubMed1983

Chromosome abnormality in couples with histories of multiple abortions. The outcome of pregnancies subsequent to ascertainment and a study of familial translocation carriers.

A series of couples with histories of recurrent abortions and in whom one partner had been shown to have a major chromosomal anomaly were investigated with respect to the karyotypes of conceptions subsequent to ascertainment. The reproductive histories of translocation carriers amongst relatives were also studied. Results were compatible with previous reports of the behaviour of translocation chromosomes at meiosis with an additional previously undescribed outcome as a result of a maternal 13/14 Robertsonian translocation.

Abortion, Habitual↗

PubMed1982

Vaccinia virus-induced changes in [Na+] and [K+] in HeLa cells.

A flame photometric technique is described for determining average values for intracellular [Na+] and [K+] in HeLa cells. Ion measurements were made on unwashed cells disrupted ultrasonically in the presence of residual medium; corrections for the latter were made by measurement of extracellular volume in cell plus medium preparations using 125I-labelled polyvinylpyrrolidone (PVP) as the marker in an isotopic dilution technique. Accurate measurement of the volume occupied by the cells was critical and required a concentration step. This was achieved by concentrating cell suspensions in a microhaematocrit centrifuge using calibrated capillary tubes. Most reliable values were obtained in our system using HeLa S3 (suspension) cells grown as monolayers, which were removed by EDTA and held in suspension for a minimum of 2 h. Uninfected HeLa cells had values of 20 to 30 and 110 to 120 mM for Na+ and K+ respectively. At 13 h after inoculation with vaccinia virus, a dramatic reversal in [Na+] and [K+] occurred, but throughout the infection cycle the total [Na+ + K+] varied little. The significance of these data is discussed in relation to theories of virus-induced modulation of protein synthesis in infected cells and in cell-free systems.

Cytoplasm↗

PubMed1977

Vaccinia virus cytotoxin.

Extracts of vaccinia-infected HeLa cells were rendered free from infectious virus by centrifugation followed by membrane filtration and were shown to be toxic to uninfected HeLa cells in the presence of hypertonic MgSO4, used as a macromolecular uptake inducer, under conditions which did not kill control cells. Extracts from uninfected cells were nontoxic. This biological test was adapted to a semi-quantitative assay which was used to monitor the purification of the cytotoxic factor by DEAE-cellulose and Sephadex G-100 chromatography. The cytotoxic factor was purified 100-fold, shown to be of molecular weight 30 -- 100,000 daltons, acidic and completely inactivated by soluble trypsin but not by ribonuclease under conditions believed to degrade both single- and double-stranded RNA species. It was demonstrated to be virus specific by approrpiate immunosorbent chromatography. Extracts were also prepared from vaccinia-infected HEp-2, RK and W-K cells respectively. A virus-specific factor, toxic to uninfected HeLa cells, with similar chromatographic properties to that isolated from infected HeLa cells, was isolated from these three additional cell lines. The concept of virus induced cytotoxins, substances which exert their toxic effect in the host cells in which they are made, is discussed.

Antigens, Viral↗

PubMed1977