Biomedical subjects

S Ringler

Publications and source records attributed to S Ringler.

3 recordsLinked to original sources

PubMed1990

Interaction of canine distemper virus nucleocapsid variants with 70K heat-shock proteins.

Cytoplasmic nucleocapsid (NC) isolated from Vero (V) cells infected in the logarithmic phase of growth with Onderstepoort canine distemper virus consists of light-NC (L-NC) and dense-NC (D-NC), encapsidating full-length genomic RNA, and defective-NC (Df-NC), encapsidating variably truncated RNAs. The 70K host cell protein constituent of L-NC and Df-NC was shown to be a member of the 70K heat-shock protein (70K hsp) family. Specifically, 72K hsp is associated with L-NC, and 72K and 73K hsp are associated with Df-NC. Variable L-NC production by three different Vero cell sublines was compared to cellular 70K hsp levels. V141 supported the highest level of L-NC production and expressed high basal levels of 70K hsp in uninfected cells. These high basal levels correspond to a large distribution of log phase V141s in the S phase of the cell cycle. V138-L and V138-H cells produced lower amounts of L-NC and exhibited similar low basal levels of 70K hsp expression, corresponding to low percentages of log phase cells in the S phase cell cycle compartment. Heat shock was effective in inducing L-NC expression in V138-H, which otherwise produced D-NC. Similar cell subline differences in L-NC production were obtained for eight different virus pools derived from the same plaque-purified parental stock. Enhanced biological activity was associated with L-NC based on correlation between L-NC production, viral titre, and plaque areas measured over infected cells.

Animals↗

PubMed1989

Lymphocyte function in obstructive jaundice.

Sepsis is a major factor in the high mortality and morbidity after surgery for obstructive jaundice. Several studies have suggested that reticuloendothelial function is depressed, but changes in lymphocyte function are poorly understood. A model of obstructive jaundice has been produced by chronic common bile duct ligation in eight dogs. In vitro lymphocyte studies were performed both at 2 and 3 weeks duration of jaundice and compared with simultaneous healthy control subjects. Icteric animals showed no abnormality of natural killer cell function. Relative numbers of T and B lymphocytes and their subsets were unchanged. T lymphocyte responses to three mitogens were not significantly reduced in jaundiced animals. Serum immunoglobulin levels were unchanged compared to those before surgery apart from a significant rise in immunoglobulin A. No evidence of circulating immunosuppressive factors was found by mitogen testing on normal lymphocytes in the presence of pooled serum from jaundiced animals, normal serum, or normal serum with added bilirubin. Our study does not suggest that impairment of lymphocyte function contributes significantly to the dangers of sepsis in obstructive jaundice.

Animals↗

PubMed1989

Rapid isolation of morbillivirus nucleocapsid for genomic RNA cDNA cloning and the production of specific core protein antisera.

A procedure is described for the rapid isolation of canine distemper virus nucleocapsid, free from contaminating viral non-core and host cellular proteins. Nucleocapsid isolated in this manner is amenable to ultrastructural evaluation, protein isolation for the production of monospecific hyperimmune serum, and genomic RNA isolation for cDNA cloning. Nucleocapsid (NC) and a defective NC variant (Df-NC) isolated from 5.5 x 10(7) Vero cells infected with Ond-CDV is readily visualized on cesium gradients. The calculated density for NC is 1.2976 +/- 0.0033 g/ml and 1.2458 +/- 0.0056 g/ml for Df-NC. Ultrastructurally, NC appears as long uninterrupted strands, 1.6 +/- 0.1 microns in length, 21.2 +/- 1.7 nm in diameter, with well defined capsid subunits. Df-NC are truncated with a uniform length of 85.8 +/- 7.1 nm and a 24.5 +/- 1.3 nm diameter. A total of 2.1 +/- 0.2 mu of NC protein is obtained for every 1 x 10(6) cells infected; 89.7% of this mass is represented by a 61 kDa protein (N), 8.4% by a 75 kDa protein (P), and 1.9% by a 160-200 kDa protein (L), which is in agreement with the NC constituency of other paramyxoviruses. Viral N and P proteins, purified by 7.5% SDS-PAGE, were used in the production of hyperimmune serum. Specificity was demonstrated by Western blot analysis. Both antisera were capable of detecting viral antigen in persistently and lytically CDV infected cells by indirect immunofluorescence. A single high molecular weight species of nucleic acid was isolated from purified nucleocapsids compatible with a 14.6 kb morbillivirus genome. Although the efficiency of RNA extraction from purified NC was low (14.2%), sufficient RNA was obtained for gel analysis and the establishment of genomic RNA cDNA clones.

Antibodies, Viral↗