James E. Shaw

Treatment of life-threatening Epstein-Barr virus infections with acyclovir☆

Two pediatric patients with life-threatening Epstein-Barr virus infections were studied immunologically and treated with acyclovir [9-(2-hydroxyethoxymethyl) guanine]. The patient with chronic active Epstein-Barr virus infection who experienced massive hepatosplenomegaly, pancytopenia, and failure to thrive demonstrated abnormalities of T and B lymphocytes. A second patient, with the X-linked lymphoproliferative syndrome, experienced a rapidly fatal course of acute Epstein-Barr virus infection which typifies this yet undefined immunodeficiency to Epstein-Barr virus. In each case, objective evidence for clinical improvement or antiviral effect of acyclovir treatment was not apparent. Abnormally productive Epstein-Barr virus infections did not appear to play a major role in the clinical syndromes observed. Current studies are focused on treatment of immunologically normal patients with early complicated Epstein-Barr virus infection.

Effect of 12-O-tetradecanoyl-phorbol-13-acetate on the replication of Epstein-Barr virus. I. Characterization of viral DNA

The tumor promoter, 12-O-tetradecanoyl-phorbol-13-acetate (TPA), induces replication of Epstein-Barr virus (EBV) DNA in a virus-producing human lymphoblastoid cell line, P3HR-1, but not in a nonproducer cell line, Raji. A 6-fold increase in EBV genome copies per P3HR-1 cell parallels the increase in percentage of cells synthesizing viral capsid antigen. In situ cytohybridization with EBV-specific cRNA shows that most of the TPA-treated population participates in the virus-productive cycle. In Raji cells there is abortive induction with an increase in cells showing early antigen from <0.01% to approximately 10%, but there is no increase in EBV genome copies per cell. The optimal TPA concentration for induction of viral DNA replication is 10 ng/ml. EBV DNA synthesized in Raji cells superinfected by virus prepared from TPA-induced P3HR-1 cells is increased approximately 15-fold above that of Raji cells superinfected with control virus. The buoyant density of EBV DNA isolated from virus from TPA-induced cells or of DNA from Raji cells superinfected with TPA-induced and control virus is identical; viral DNA from all sources had the same S value. The XhoI restriction endonuclease digestion patterns of TPA-induced viral DNA and control viral DNA were the same as the viral DNA recovered from Raji cells superinfected with TPA-induced and control virus. Some differences were noted in the molar ratios of some of the fragments.

Replication of Epstein-Barr virus DNA in lymphoblastoid cells treated for extended periods with acyclovir

An Epstein-Barr virus (EBV)-producing human lymphoblastoid cell line (P3HR-1) was characterized after prolonged exposure to 9-(2-hydroxyethoxymethyl)guanine (acyclovir). P3HR-1 cells grown for 11 months in the presence of acyclovir had the same number of EBV genomes (approximately 15/cell) as did short-term acyclovir-treated cells. After removal of the drug, the number of EBV genome equivalents of long-term acyclovir-treated cultures (15/cell) returned to P3HR-1 control levels (340/cell). Indirect immunofluorescence studies demonstrated reduced percentages of long-term (6 to 12 months) acyclovir-treated P3HR-1 cells expressing both EBV early antigens (EA) and viral capsid antigens (VCA). This contrasts with short-term acyclovir-treated cultures where EA is expressed at normal levels even though VCA expression is reduced. Restriction fragment patterns of the total EBV DNA from both short and long-term acyclovir-treated cultures were identical with the exception of two fragments present in short- but not long-term acyclovir-treated cultures. EBV-associated DNA polymerase was present in long-term acyclovir-treated cultures with the level of activity, as determined by assay in vitro, comparable to that in untreated P3HR-1 cells. The polymerase activity in the treated cells was sensitive in vitro to acyclovir triphosphate, N-ethyimaleimide (NEM), and phosphonoacetic acid (PAA). These studies demonstrate that acyclovir inhibits the EBV-productlve cycle in P3HR-1 cells continuously during extended periods of treatment.

CANCER PREVENTION KNOWLEDGE, ATTITUDES, AND CLINICAL PRACTICE OF NURSE PRACTITIONERS IN LOCAL PUBLIC HEALTH DEPARTMENTS IN NORTH CAROLINA

This study discusses the findings from a survey of the knowledge, attitudes, and clinical practice regarding cancer prevention and early detection of 101 nurse practitioners (NPs) working in the 87 county public health departments in North Carolina. Results show that nurse practitioners provide breast and cervical cancer screening services for most women over age 40 but are less likely to provide other types of cancer prevention, such as smoking cessation counseling or education about diet and cancer. NPs tended to rate their clinical skills in providing cancer screening as excellent but rate their skills in educating clients about cancer risk lower. Most NPs were interested in practice related to cancer control, especially learning more about the latest recommendations on cancer. However, in this study they indicated the least interest in learning more about smoking cessation methods or cancer prevention issues for men. These findings suggest that NPs in public health need further education and skills training related to cancer control, in addition to breast and cervical cancer screening.

Epstein-Barr virus DNA synthesized in superinfected raji cells

Abstract Raji and P3HR-1 are established Burkitt lymphoma-derived cell lines that carry the Epstein-Barr virus (EBV) genome. Superinfection of the Raji cell line, a non-virus-producer, with virus from P3HR-1 cells results in the synthesis of several thousand copies of EBV-DNA per cell with attendant inhibition of synthesis and breakdown of Raji cell DNA. The DNA synthesized in superinfected Raji cells has been characterized. Raji cells infected with P3HR-1 virus and labeled with 32P 10 hr after infection synthesized only viral DNA. As much as 90% of the 55 S, 32P-labeled material was localized in the nucleus of superinfected cells after a 10-hr labeling period. The viral DNA purified from superinfected cells had the same buoyant density as the DNA isolated from P3HR-1 virions and after purification could be recovered with a specific activity exceeding 106 cpm/μg in an amount which approached 10 wg/107 infected Raji cells. The viral DNA from superinfected cells reassociated with the DNA from Raji or P3HR-1 cells and with the DNA from virus but did not reassociate with DNA from cell line 698 (a lymphoblastoid cell line lacking the EBV genome). Nuclei isolated from superinfected Raji cells incorporated label from deoxythymidine triphosphate into an acid-insoluble product, most of which had a buoyant density identical to that of DNA from P3HR-1 virions. Digestion of the DNA from superinfected cells with the restriction endonuclease EcoRI produced a number of fragments with molecular weights which ranged from less than 1 million to approximately 30 million when analyzed by electrophoresis on agarose gels. All of the fragments produced by digestion of DNA from virus were present in the digest of DNA from superinfected Raji cells.

Computerized medical records with health care maintenance reminders increased recommendations for some preventive health care protocols

Source Citation Tape TG, Campbell JR. Computerized medical records and preventive health care: success depends on many factors. Am J Med. 1993 Jun;94:619-25.

Dietary risk factors and colorectal adenomatous polyps

Source Citation Neugut AI, Garbowski GC, Lee WC, et al. Dietary risk factors for the incidence and recurrence of colorectal adenomatous polyps. A case-control study. Ann Intern Med. 1993 Jan 15:118...

Effect of acyclovir on herpes simplex virus replication in a persistently infected human lymphoblastoid cell line (P3HR-1)

Abstract We examined the effect of acyclovir on herpes simplex virus (HSV) replication in the persistently infected human lymphoblastoid cell line, P3HR-1. During 10 days of continuous exposure of P3HR-1 cells to 100 μ M acyclovir there was a decrease in the number of cells expressing HSV antigens, the number of copies of HSV DNA per cell, and the infectivity of extracellular virus. A significant increase in each of these was detected after 14 days of continuous exposure of P3HR-1 cells to the drug, demonstrating that the replication of HSV has become resistant to inhibition by acyclovir. No apparent resistance of EBV replication to inhibition by acyclovir, however, was detected in HSV-infected P3HR-1 cells. The number of copies per cell of EBV and HSV DNA increased after exposure of HSV-infected P3HR-1 cells to the tumor promoter TPA (12-O-tetradecanoyl-phorbol-13-acetate). When cells were exposed continuously to acyclovir for four months and then exposed to acyclovir and TPA simultaneously, the number of copies per cell of HSV DNA increased, but the number of copies per cell of EBV DNA increased by only a few, if any. The detection in P3HR-1 cultures of individual cells expressing both HSV and EBV antigens suggested that HSV and EBV productive cycles could occur simultaneously within the same cell. However, single cells very rarely expressed both antigens simultaneously.