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Biomedical subjects

D Korn

Publications and source records attributed to D Korn.

95 records · Page 6Linked to original sources

DNA synthesis on UV irradiated model templates using human DNA polymerases alpha and beta: primer slippage to account for evident transdimer continuity in product.

We have studied the comparative behavior of human DNA polymerases alpha and beta on a polynucleotide template of dT100 with dA15 covalently attached at the 3' end to serve as primer when defined numbers of pyrimidine dimers are introduced by UV (254 nm) irradiation. We have obtained the surprising result that with both alpha and beta polymerases the incorporation of labelled dATP is enhanced when the template has been irradiated (maximum value at 1000 J/m2 UV incident dose). In the presence of Mn2+, DNA polymerase beta produces a product size corresponding to full copying of the template whether irradiated or not. In marked contrast DNA polymerase alpha produces only short products on unirradiated strands but full copying of irradiated templates. Evidently both polymerases utilize a much larger fraction of the template pool following UV irradiation.

DNA Polymerase I↗

Cytokines in the nasal washes of children with respiratory syncytial virus bronchiolitis.

Although respiratory syncytial (RS) virus is the major cause of bronchiolitis and pneumonia in young children, the factors that regulate the associated lung inflammation have not been defined. The levels of interleukin (IL)10, IL-12, and interferon (IFN) were determined in the nasal wash samples from 20 infants with a clinical diagnosis of bronchiolitis, seven with confirmed RS virus infections and 9 control children without respiratory illnesses. IL-10 levels were significantly higher in acute nasal wash samples (1-4 d post hospitalization) from RS virus-infected infants than in convalescent samples from these children (14-21 d post-hospitalization), from children with other forms of bronchiolitis and from control children. In contrast, only one RS virus-infected infant had detectable IL-12 in an acute nasal wash sample. IFN activity was not detected in any samples from RS virus-infected children. RS virus infection stimulates IL-10 expression but not IL-12 and IFN, possibly contributing to an ineffective cell-mediated immune response.

Acute Disease↗