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K Sandvej

Publications and source records attributed to K Sandvej.

25 records · Page 2Linked to original sources

Epstein-Barr virus-latent gene expression and tumor cell phenotype in acquired immunodeficiency syndrome-related non-Hodgkin's lymphoma. Correlation of lymphoma phenotype with three distinct patterns of viral latency.

We investigated 49 acquired immunodeficiency syndrome-related lymphomas (ARLs) for Epstein-Barr virus (EBV) by Southern blotting and in situ hybridization and, in positive cases, used cryostat immunohistology to compare EBV-latent gene expression (EBV encoded small RNA-1 [EBER-1], EBV nuclear antigen-2 [EBNA-2], latent membrane protein-1 [LMP-1] and host cell immunophenotype (CD11a, CD18, CD54, CD58, CD21, CD23, CD30, CD39, CDw70, immunoglobulin) patterns with those reported in other EBV infections. EBV+ immunoblast-rich/large cell ARLs (n = 22) showed three patterns of latency: broad (EBER+EBNA-2+/LMP-1+; n = 9), reminiscent of a lymphoblastoid cell line phenotype; restricted (EBER+/EBNA-2-/LMP-1-; n = 6), similar to endemic Burkitt's lymphoma; and intermediate (EBER+/EBNA-2-/LMP-1+; n = 7), a pattern rarely described in vitro but seen in certain EBV-related malignancies. EBNA-2 expression was associated with extranodal lymphomas. EBV+ Burkitt-type ARLs (n = 11) usually showed the restricted latency pattern (n = 8), but some expressed the intermediate form (n = 3). Adhesion (CD54, CD58) and activation (CD30, CD39, CDw70) molecule expression varied with morphology (immunoblast-rich/large cell versus Burkitt-type), but was not independently correlated with EBV-positivity. CD30 and LMP-1 expression were associated. ARLs show heterogeneity regarding both the presence of EBV and latency pattern. Comparison of these phenotypically distinct lymphoma groups with known forms of EBV infection provides clues to their possible pathogenesis.

Adult↗

Epstein-Barr virus latent and replicative gene expression in oral hairy leukoplakia.

Oral hairy leukoplakia is an epithelial lesion of the tongue associated with productive infection by Epstein-Barr virus (EBV). However, no data concerning the pattern of EBV latent gene expression have been reported, and it remains unresolved whether true latent infection occurs in basal cell layers of oral hairy leukoplakia. We have studied six cases of oral hairy leukoplakia using monoclonal antibody immunohistology for EBV latent--EB nuclear antigen (EBNA) 1, EBNA 2 and latent membrane protein 1 (LMP 1); immediate-early (BZLF1); and replicative (EA, VCA, MA) proteins, and for the EBV-receptor (CD21 antigen). EBV DNA was demonstrated by nucleic acid in situ hybridization. Mid- to upper-zone keratinocytes contained EBV DNA and co-expressed EBNA 1, EBNA 2 (5 of 6 cases), LMP 1, BZLF1 protein, EA, VCA and MA. No EBV genome or gene expression could be demonstrated in basal or parabasal cells. Spinous keratinocytes were labelled by anti-CD21 antibodies HB5 and B2, but did not express the EBV-receptor as defined by reactivity with OKB7. The co-expression of latent and replicative infection-associated antigens is striking, indicating possible functional roles for latent proteins during the productive cycle. Our results suggest that oral hairy leukoplakia is caused by repeated direct infection of upper epithelial cells with virus from saliva or adjacent replicatively infected cells, rather than by a latent EBV infection of basal epithelial cells with a differentiation-dependent switch to productive infection as previously proposed.

Adult↗

Activation of Epstein-Barr virus replication in Hodgkin and Reed-Sternberg cells.

Recent evidence has shown that Hodgkin's disease (HD) is associated with Epstein-Barr virus (EBV) in a substantial number of cases and that in these cases EBV DNA is localized exclusively to Hodgkin and Reed-Sternberg (RS) cells. The virus genome is not silent in RS cells because two EBV latent gene products, latent membrane protein (LMP) and EB early region (EBER) transcripts, have recently been reported to be expressed in RS cells. However, little information is available about the possible activation of EBV replicative genes in HD. This prompted us to investigate HD biopsies from 96 patients for expression of replicative gene products. Cryostat sections were immunostained with monoclonal antibodies to protein BZLF1, which controls the switch between EBV latency and replication, and also to LMP. LMP was demonstrated in RS cells in 47 cases (49%). Three of the LMP-positive cases (6%), but none of the LMP-negative cases, expressed the BZLF1 protein. BZLF1 positively was confined to rare RS cells. These three cases showed no detectable early, virus capsid, or membrane antigens. Our findings show that activation of EBV immediate early genes occurs only infrequently in RS cells, indicating that control of viral latency is not severely impaired in HD patients.

Antigens, Viral↗

Expression of Epstein-Barr virus replicative proteins in AIDS-related non-Hodgkin's lymphoma cells.

Epstein-Barr virus (EBV) infection in lymphoproliferative lesions has been assumed to be strictly latent. In order to investigate the possible occurrence of EBV replication in AIDS-related lymphoma (ARL) cells, we studied 13 cases by immunohistology using monoclonal antibodies to the EBV-encoded switch-protein BZLF1, early antigens (EAs), late replicative proteins [virus capsid antigens (VCAs) and membrane antigens (MAs)], and to the latent proteins EB nuclear antigen 2 (EBNA 2) and latent membrane protein (LMP). EBV genomes were detected by in situ hybridization. EBV genomes and/or gene products were demonstrated in ten cases, including all immunoblast-rich lymphomas, two Burkitts lymphomas, and a T-cell anaplastic large-cell lymphoma. The BZLF1 protein, which disrupts latency in B cells, was identified in six (60 per cent), and EAs in four (40 per cent) of the EBV-positive ARL. Only one lymphoma (10 per cent) expressed VCAs and MAs. EBNA 2 and LMP were detected in three (30 per cent) and eight (80 per cent) of EBV-positive cases, respectively. EBV DNA was detected in lymphoma cells in 7 of 12 (58 per cent) cases. The most important finding of this study was frequent spontaneous activation of latent EBV in ARL. Production of complete virus, however, was either aborted, or tumour cells expressing late productive cycle proteins (VCA, MA) were rapidly cleared from tissues. It is suggested that host factors that normally inhibit replication of EBV are deficient in AIDS patients.

Adult↗

Injuries in high-skilled and low-skilled soccer: a prospective study.

Fifty-five male soccer players organized in three teams, one high and two lower ranking, were followed prospectively during 1 year to register the rate, type and severity of injuries in highly skilled and low-skilled players. The injury rate of the low-skilled players was significantly higher than that of the better players. The reason for this is that low-skilled players play in more competitions. and this is where injuries tend to occur. When we stratified on game/practice, the low-skilled players' excess risk disappeared and no difference was found in the severity of injuries. Different ways of collecting data in epidemiological studies of soccer are discussed and it is concluded that the most precise and accurate collection of data can only be obtained by direct supervision and examination of soccer players in the field.

Adult↗