Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.7 (DNA polymerase)
 17,007 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In a study of the distribution of e-antigen and anti-e in subjects whose blood was positive for hepatitis B surface antigen (HBsAg), patients with acute hepatitis B who were tested during the incubation period were all e-antigen-positive but after the onset of illness e-antigen was detected in only 11%. Persistence, and in some instances reappearance of e-antigen in those who became long-term carriers of HBsAg was associated with high titres of HBsAg. There was a high incidence of e-antigen in those conditions in which cell-mediated immunity may be depressed, including Down's syndrome and chronic renal failure. The majority of HBsAg carries identified as sources of infection were e-antigen-positive. A postive reaction for e-antigen is evidently associated with a defective immune response to hepatitis B virus infection which permits continued replication of virus in liver cells accompanied by high titres of HBsAg, numerous Dane particles and detectable DNA polymerase in the blood with consequently a greater likelihood of transmitting infection. Although it cannot be assumed that anti-e positive carriers of HBsAg are not infective, it may be necessary, in the assessment of passive or active immunization for the control of hepatitis B, to take into account the e-antigen/antibody status of possible sources of infection.
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PMID:e-Antigen: a link between immune response and infectivity in hepatitis B? 73 Oct 22

Low-dose ionizing radiation caused definite stimulation of immune reactions both in humans and mice. The PFC reaction in response to SRBC immunization and the NK activity of the splenocytes were significantly enhanced after low-dose whole body irradiation. Activation of the T lymphocytes, especially the TH, with increased production of IL-2, might be a critical step in the whole process of immunoenhancement. A single dose of 75 mGy X-rays caused significant lowering of hypothalamic M-Enk content as well as serum corticosterone level. The increased serum testosterone level would exert an inhibitory influence on the CRF-ACTH-CS system to keep the blood corticosterone at a lower than normal level which might facilitate the immune reactions in the SRBC-immunized animals. The increased catecholamines in the spleen would probably reinforce this effect resulting in immunoenhancement. Low-dose ionizing radiation caused increased repair of the genetic material at both the molecular and subcellular levels. The UDS of human and murine lymphocytes was augmented by single or continuous low-dose irradiation. The stimulation of DNA polymerase activity might be responsible for such effects. Exposure to very small doses of low LET radiation could induce in different tissues an adaptive response which alleviated chromosome damage caused by subsequent larger dose radiation. Such an adaptive response could be induced both in vivo and in vitro in different animal species. The induced adaptive response faded away after 3 cell cycles could be re-induced by a second exposure to low-dose radiation. The mechanism of the inductive process needs further study.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Radiation hormesis. A new concept in radiological science. 251 54