Translational studies in older men using testosterone to treat sarcopenia.

Sarcopenia is the loss of skeletal muscle mass and strength that occurs with aging. Our research group has found an efficacious administration paradigm using testosterone to combat sarcopenia in humans. In addition, our research has uncovered an important regulatory enzyme of inflammation, nuclear factor-κB-inducing kinase that may regulate human skeletal muscle catabolism, and that appears to be counter-regulated by administration of standard doses of testosterone. This is important because a number of age-related clinical circumstances trigger acute and chronic muscle loss including cancer, chronic obstructive pulmonary disease, hospitalization, acute and chronic illness, and diseases in which systemic inflammation occurs. Moreover, it is often the treatment itself that can induce muscle loss. For example, glucocorticoids are tremendously effective at reducing inflammation and are a frontline therapy for many inflammatory-based diseases, yet paradoxically trigger muscle loss. We will discuss our research findings and the clinical significance of our human clinical translational research with testosterone.

Physical strain during activities of daily living of patients with coronary artery disease.

The purpose of this study was to determine the physical strain of activities of daily living (ADL) in patients with coronary artery disease (CAD) compared with healthy controls. Seventeen patients with CAD and 15 controls performed a graded exercise bicycle test and 5 ADL tasks: walking with/without load, vacuum cleaning, undressing, and walking stairs. Peak heart rate (HRpeak) and peak oxygen uptake (VO(2) peak) were determined during the bicycle test. Heart rate (HR) and oxygen uptake (VO(2)) were continuously measured during all ADL tasks. Physical strain during ADL tasks was calculated using HR and VO(2) response, expressed relative to individual HR and VO(2) reserves (%HRR, %VO(2) R, respectively). Perceived strain was measured using the Rating of Perceived Exertion (RPE) scale. HRpeak and VO(2) peak were lower (P<0·001) in patients. Patients performed the ADL tasks slower and with lower absolute VO(2), except for undressing. HR was only higher in patients during stair climbing. No differences in RPE scores were found between both groups, except for undressing. However, physical strain was significantly higher in patients (mean %VO(2) R ranged from 43% to 51%; mean %HRR ranged from 38% to 47%) compared with controls (mean %VO(2) R: 14% to 30%; mean %HRR: 14% to 29%) for all ADL tasks. In general, ADL tasks were performed slower and with higher physical strain in patients with CAD compared with controls.

Biophysical aspects of submaximal hand cycling.

Hand cycling is a popular form of wheeled mobility. This study evaluates biophysical differences between synchronous/asynchronous hand cycling. During submaximal hand cycling on a motor driven treadmill, 9 able-bodied subjects performed 2 series of 4 steady state exercise bouts at 1.11 to 2.78 m/s. Metabolic parameters, mean force on the handle bar, muscle activity and local perceived exertion in the upper body were determined. Mean power output was 35.4 +/- 7 W (v = 2.78 m/s). At this speed oxygen uptake was 1.11 +/- 0.25 and 1.26 +/- 0.26 l/min for the synchronous and asynchronous modes, respectively. Mechanical efficiency was significantly higher (v = 2.78 m/s: + 11.5 %) in synchronous cycling. Higher activity of m. obliquus externus and extensor carpi ulnaris was seen. Mean 2D total force and fraction effective force on the handle bar were lower in asynchronous hand cycling. Local perceived discomfort was higher in the asynchronous mode for different arm regions. Synchronous hand cycling is more efficient and at a lower metabolic cost. Mean muscle activation and the local perceived discomfort may explain some results. Future study should focus on combined time-based force and muscle activity characteristics. Synchronous hand cycling should be preferred during submaximal exercise in early rehabilitation.

Enterotoxigenic Escherichia coli secretes active heat-labile enterotoxin via outer membrane vesicles.

Escherichia coli and other Gram-negative bacteria produce outer membrane vesicles during normal growth. Vesicles may contribute to bacterial pathogenicity by serving as vehicles for toxins to encounter host cells. Enterotoxigenic E. coli (ETEC) vesicles were isolated from culture supernatants and purified on velocity gradients, thereby removing any soluble proteins and contaminants from the crude preparation. Vesicle protein profiles were similar but not identical to outer membranes and differed between strains. Most vesicle proteins were resistant to dissociation, suggesting they were integral or internal. Thin layer chromatography revealed that major outer membrane lipid components are present in vesicles. Cytoplasmic membranes and cytosol were absent in vesicles; however, alkaline phosphatase and AcrA, periplasmic residents, were localized to vesicles. In addition, physiologically active heat-labile enterotoxin (LT) was associated with ETEC vesicles. LT activity correlated directly with the gradient peak of vesicles, suggesting specific association, but could be removed from vesicles under dissociating conditions. Further analysis revealed that LT is enriched in vesicles and is located both inside and on the exterior of vesicles. The distinct protein composition of ETEC vesicles and their ability to carry toxin may contribute to the pathogenicity of ETEC strains.

Protection against Mycobacterium avium by DNA vaccines expressing mycobacterial antigens as fusion proteins with green fluorescent protein.

Mycobacterium avium causes disseminated disease in humans with AIDS, paratuberculosis in ruminants, lymphadenopathy in swine, and tuberculosis in birds. We constructed DNA vaccines expressing mycobacterial antigens as fusion proteins with enhanced green fluorescent protein (EGFP). Plasmids p65K-EGFP, p85A-EGFP, and p85B-EGFP expressed the M. avium 65-kDa antigen, the Mycobacterium bovis BCG 85A antigen, and the M. avium 85B antigen, respectively, as EGFP fusion proteins. We visualized protein expression directly in cultured murine fibroblasts and intact muscle. p65K-EGFP expressed fusion protein in a diffuse cytoplasmic pattern, and p85A-EGFP and p85B-EGFP produced a speckled pattern. We vaccinated C57BL/6 mice with three doses of plasmid DNA and then challenged them intraperitoneally with M. avium. Negative controls received saline, and positive controls received one dose of BCG vaccine. Mice in all groups developed disseminated infection with a high burden of organisms. Compared to negative controls, mice vaccinated with p85A-EGFP had an eightfold reduction in spleen M. avium CFU at 4 weeks after infection and a fourfold reduction at 8 weeks, reductions similar to those generated by BCG vaccine. Mice vaccinated with p65K-EGFP had a fourfold CFU reduction at 4 weeks and no effect at 8 weeks. This is the first report of DNA vaccines expressing foreign antigens as fusion proteins with EGFP and the first report of successful DNA vaccination against M. avium.

Low p53 and high bcl-2 expression in Reed-Sternberg cells predicts poor clinical outcome for Hodgkin's disease: involvement of apoptosis resistance?

A high number of activated cytotoxic T lymphocytes (CTL) in Hodgkin's disease (HD) biopsy specimens is related to an unfavorable clinical outcome, suggesting that resistance of the Hodgkin and Reed-Sternberg (H-RS) cells to CTL-mediated killing is an important pathogenic factor in HD. bcl-2 and defective p53 are known to inhibit apoptosis induced either by CTLs or by therapy. The purpose of this study was to use immunohistochemical techniques to analyze whether differences in expression of these proteins in H-RS cells in primary biopsy specimens from 78 patients with HD were related to clinical outcome and to assess the number of CTLs in those cells. Cases with H-RS cells mostly staining positive for bcl-2 but negative for p53 had a poor prognosis (55% 5-yr survival). In the group of patients whose H-RS cells had low positivity for both p53 and bcl-2, the 5-year survival was 90%. p53 expression in a high percentage of H-RS cells was invariably related to a 100% 5-year survival, irrespective of bcl-2 expression. Biopsy specimens from patients with a fatal clinical outcome, in which few H-RS cells expressed p53 and many H-RS cells expressed bcl-2, contained relatively many activated CTLs. These data demonstrate that the combination of expression of the apoptosis-regulating proteins p53 and bcl-2 in the H-RS cells can be used as a prognostic marker for HD, and they indicate that resistance to apoptosis of H-RS cells is an important pathogenic mechanism. Our data also support the hypothesis that in patients with a poor prognosis, apoptosis-resistant H-RS cells might be selected for by the presence of many activated CTLs.

HOXC4, HOXC5, and HOXC6 expression in non-Hodgkin's lymphoma: preferential expression of the HOXC5 gene in primary cutaneous anaplastic T-cell and oro-gastrointestinal tract mucosa-associated B-cell lymphomas.

Most of the 39 members of the homeobox (HOX) gene family are believed to control blood cell development. HOXC4 and HOXC6 gene expression levels increase with differentiation of lymphoid cells. In contrast, HOXC5 is not expressed in the lymphoid lineage, but was found in lymphoid cell lines, representing the neoplastic equivalents of various differentiation stages of T and B lymphocytes. In the present study, we investigated the HOXC4, HOXC5, and HOXC6 gene expression pattern in 89 non-Hodgkin's lymphomas (NHLs) of different histologic subtypes and originating from different sites. Using RNA in situ hybridization and semiquantitative reverse transcription-polymerase chain reaction, we found expression of HOXC4 in 83 of 88 and HOXC6 in 77 of 88 NHLs and leukemias investigated. In contrast, HOXC5 expression was found in only 26 of 87 NHLs and appeared to be preferentially expressed by two specific subsets of lymphomas, ie, primary cutaneous anaplastic T-cell lymphomas (9 of 9) and extranodal marginal zone B-cell lymphomas (maltomas; 7 of 9). These results indicate that, in contrast to HOXC4 and HOXC6, HOXC5 shows a type- and site-restricted expression pattern in both T- and B-cell NHLs.

Adenolymphoma and non-Hodgkin's lymphoma of the salivary glands and oral cavity in immunocompetent patients are not associated with latent Epstein-Barr virus.

The presence of Epstein-Barr virus (EBV) was studied in specimens of 50 primary non-Hodgkin's lymphomas (NHL) of the salivary gland and the oral cavity and 11 solitary adenolymphomas of the parotid gland, using EBER-1/2 in situ hybridisation and by immunohistochemistry for the detection of latent membrane-protein-1 (LMP-1). None of the patients were tested for HIV-infection, nor were there any clinical signs to suspect HIV-infection. In one adenolymphoma, few reactive EBER-1/2 positive cells were detected. In this case staining for LMP-1 was negative. In one oral B-cell NHL, EBER-1/2 positive lymphoma cells were identified; these cells also expressed LMP-1. None of the 31 oral (30 B-cell and one T-cell) and 18 salivary gland (all B-cell) NHLs and none of the 10 adenolymphomas were EBER-1/2 positive or expressed LMP-1. These results indicate that EBV is not involved in the pathogenesis of oral and salivary gland primary NHL and adenolymphoma in immunocompetent patients.

Expression of epstein-barr virus encoded nuclear antigen 1 in benign and malignant tissues harbouring EBV.

AIMS: To determine levels of expression of Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) in benign and malignant tissues harbouring EBV in relation to EBNA1 promoter usage. METHODS: Expression of EBNA1 was investigated by means of immunohistochemistry using a mixture of two EBNA1 specific monoclonal antibodies, 1H4-1 and 2B4-1. The presence of EBV was detected by EBER1/2 RNA in situ hybridisation. Detection of promoter specific EBNA1 transcripts was by RT-PCR analysis. RESULTS: EBNA1 positive cells were detected in all 20 EBV associated B cell lymphomas, 18 of which had arisen in immunocompromised patients; in eight of nine EBV associated T cell lymphomas; in 11 of 27 EBV positive cases of Hodgkin's disease; and in reactive lymphoid tissue harbouring EBV, including four cases of infectious mononucleosis. A diffuse EBNA1 staining pattern was observed in most of the EBV associated B cell lymphomas and was comparable with the EBER1/2 staining pattern. In the T cell lymphomas the number of EBNA1 positive cells was usually considerably less than the number of EBER1/2 positive ones. RT-PCR analysis revealed that in tumours with restricted EBNA1 expression-that is, T cell lymphomas and Hodgkin's disease lesions, EBNA1 transcripts were usually generated only by the F/Q promoter, whereas in B cell lymphomas EBNA1 transcripts were usually generated by both the C/W and F/Q promoters. CONCLUSIONS: EBNA1 is expressed in all types of tissue harbouring EBV, but the level of expression varies greatly. This may be the result of differential promoter usage.

Analysis of major histocompatibility complex class I expression on Reed-Sternberg cells in relation to the cytotoxic T-cell response in Epstein-Barr virus-positive and -negative Hodgkin's disease.

To get insight into the failure of the immune system to eradicate Epstein-Barr virus (EBV) harboring Hodgkin and Reed-Sternberg cells (H-RS cells), expressing the latent membrane protein 1 (LMP1), we analyzed major histocompatibility complex (MHC) class I expression on H-RS cells in relation to the presence of activated cytotoxic cells, i.e., granzyme-B-expressing lymphocytes. H-RS cells in EBV+ cases of Hodgkin's disease (HD) were found to express significantly higher levels of MCH class I heavy- and light-chain molecules compared with EBV- HD cases. When low levels of MHc class I expression were found (mainly in EBV- cases), these were not associated with low levels of the transporter protein associated with antigen presentation 1 (TAP-1). The relatively high levels of MHC class I expression in H-RS cells in EBV+ HD cases were accompanied by significantly higher numbers of activated cytotoxic T lymphocytes (CTLs) as shown by the presence of increased numbers of CD8 and granzyme B+ lymphocytes. However, these cells were only sporadically detected in the close vicinity of the H-RS cells. These data suggest that mechanisms other than downregulation of MHC class I or TAP-1 expression on H-RS cells are involved in the failure of the immune system to eradicate EBV harboring H-RS cells. Probably, the function of activated CTLs is locally inhibited by the H-RS cells or by reactive cells in the vicinity of the H-RS cells.

Detection of heterogeneous Epstein-Barr virus gene expression patterns within individual post-transplantation lymphoproliferative disorders.

Using RT-PCR analysis of Epstein-Barr virus (EBV) latent gene transcription in EBV-harboring cell lines (JY and RAJI) and in post-transplantation lymphoproliferative disorders (PT-LPDs), we detected transcription of all tested latent genes (EBNA1, EBNA2, LMP1, LMP2A, and BARF0) in all cases, suggesting the presence of similar EBV expression patterns in both PT-LPDs and cell lines. In addition, the detection of immediate early (ZEBRA) and early gene (BHRF1) transcripts in cell lines and PT-LPDs indicates that activation of the virus lytic cycle occurs. To investigate EBV expression patterns at the single-cell level, a combination of immunohistochemistry and RNA in situ hybridization (including double-staining procedures) was used. In the JY and RAJI cell lines, the latency type 3 expression pattern was detected in 80 to 90% of the cells as shown by the co-expression of EBNA2 and LMP1. In contrast, in the three PT-LPDs that could be analyzed by double staining, cells expressing both EBNA2 and LMP1 were rarely detected. A mixture of at least three different cell populations were identified: (1) cells exclusively expressing EBER1/2 and EBNA1 (latency type 1); (2) cells expressing EBER1/2, EBNA1, and LMP1 (latency type 2); and (3) cells expressing EBER1/2, EBNA1, and EBNA2 in the absence of LMP1. Activation of the lytic cycle was observed in a small minority of cells, as demonstrated by detection of ZEBRA and EA-D in all cases and GP350/220 in two cases. Thus, in contrast to EBV-transformed cell lines, the observed EBV gene expression pattern in PT-LPDs reflects a mixture of multiple EBV-harboring subpopulations expressing different subsets of EBV-encoded proteins. These data indicate that the operational definitions of EBV latencies in vitro cannot easily be applied to PT-LPDs but that a continuum of different latency expression patterns can be detected at the single cell level in these lymphomas with, in a small minority of cells, progression to the virus lytic cycle.

Expression of bcl-2 protein and transcription of the Epstein-Barr virus bcl-2 homologue BHRF-1 in Hodgkin's disease: implications for different pathogenic mechanisms.

Epstein-Barr virus (EBV) is frequently found in Hodgkin and Reed-Sternberg cells in Hodgkin's disease. Epstein-Barr virus has transforming properties in vitro and might be involved in the pathogenesis of certain types of Hodgkin's disease. One of the possible mechanisms is the upregulation of the human proto-oncogene bcl-2 by the latent membrane protein 1 of EBV in vitro. Another possibility might be the expression of the viral 'bcl-2 homologue' BHRF-1. In the present study of 64 cases of Hodgkin's disease we investigated the expression of bcl-2 at the protein level in relation to the presence of EBV. Moreover, in 10 EBV positive cases we investigated, the expression of the bcl-2 homologue, BHRF-1, by reverse-transcriptase PCR. bcl-2 was detected in 14 of 22 (64%) EBV positive and in 37 of 42 (88%) EBV negative cases. In 17 of 22 (77%) EBV positive cases Reed-Sternberg cells were negative (n = 8) or expressed the bcl-2 protein in a very low percentage ( < 5%) of cells (n = 9), whereas in 20 of 42 (43%) of the EBV negative cases the majority ( > 50%) of the neoplastic cells were bcl-2 positive. Using the reverse-transcriptase PCR with primers amplifying transcripts of BHRF-1 we were able to detect BHRF-1 transcripts in only one of the 10 tested cases of EBV positive Hodgkin's disease. Our data indicate that in EBV positive Hodgkin's disease growth advantage of Reed-Sternberg cells is not obtained by upregulation of bcl-2 or by the EBV homologue BHRF-1.

Immunohistochemical demonstration of different latent membrane protein-1 epitopes of Epstein-Barr virus in lymphoproliferative diseases.

AIM: To compare the immunoreactivity of monoclonal antibodies S12 and CS1-4, which recognise different epitopes of the Epstein-Barr virus (EBV) latent membrane protein-1 (LMP-1), in EBV associated benign and malignant lymphoproliferative disorders and control tissues processed using different methods. RESULTS: Both monoclonal antibodies gave comparable results on frozen tissue sections and formalin fixed, paraffin wax embedded samples from cases with Hodgkin's disease and infectious mononucleosis. In all cases S12 stained more cells than CS1-4. For EBV associated B and T non-Hodgkin's lymphomas, frozen tissue sections yielded better LMP-1 staining results than formalin fixed material. Again, in all these cases S12 stained more cells and gave stronger results than CS1-4. For EBV negative tissues, both monoclonal antibodies showed cross-reactivity with melanocytic-like cells in the basal cell layer of the skin, synaptophysin-like staining in layers three and four of the cortex of the brain, and myelin-like staining in peripheral nerves and peripheral ganglion cells. Staining with S12 was always much stronger. Moreover, in contrast to CS1-4, S12 stained pancreatic islands in formalin fixed material but not in frozen tissue sections and sporadically stained solitary epithelial cells in the large bowel especially in formalin fixed tissue sections. CS1-4 also cross-reacted with myoepithelial cells around hair follicles and other adnexa of the skin. CONCLUSION: The results indicate that for optimal detection of LMP-1, S12 yields better results than CS1-4 and that tissue processing is very important especially when B and T non-Hodgkin's lymphomas are examined.

Decreased expression of cellular markers in Epstein-Barr virus-positive Hodgkin's disease.

Epstein-Barr virus (EBV) has been demonstrated in the Reed-Sternberg cells and their mononuclear variants (Hodgkin cells; H-RS cells) in a substantial number of Hodgkin's disease (HD) cases. Moreover, EBV can modulate both in vivo and in vitro the expression of several cellular genes, including lymphoid differentiation markers. Therefore we investigated, in 64 cases of HD, the relationship between the presence of EBV and the expression of lymphoid (CD45RB), T- (CD3, CD45RO), B- (CD20, MB2 antigen, CDw75), and myeloid-cell lineage markers (CD15), and of activation markers (CD30, EMA, and the 115D8 antigen) on the H-RS cells. EBV-positive cases, as demonstrated by the presence of EBER-1 and -2 RNA and LMP-1 protein expression, showed a significant reduction in the expression on H-RS cells of T-cell lineage (CD3, P < 0.02), B-cell lineage (CD20; P < 0.005), and activation markers (EMA; P < 0.002 and the 115D8 antigen; P < 0.001) as compared with EBV-negative cases. No differences were found in the expression of CD15, CD30, CD45RO, CD45RB, CDw75, or the MB2 antigen on H-RS cells in EBV-positive and EBV-negative HD cases. Interestingly, in 11 cases of EBV-negative HD, B- as well as T-cell lineage markers could be found on some H-RS cells. These data suggest that EBV in H-RS cells is able to down-regulate the expression of T- (CD3) and B- (CD20) cell lineage markers and lymphoid activation markers (EMA and the 115D8 antigen).(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of Epstein-Barr virus latent gene products and related cellular activation and adhesion molecules in Hodgkin's disease and non-Hodgkin's lymphomas arising in patients without overt pre-existing immunodeficiency.

Epstein-Barr virus (EBV) recently has been associated with Hodgkin's disease (HD) and the EBV genome was found in CD30-positive Reed-Sternberg cells. Therefore, tissue sections from 25 cases of HD, 35 cases of CD30-positive non-Hodgkin's lymphoma (NHL) (seven CD30-positive anaplastic large cell lymphomas [ALCLs] and 28 CD30-positive non-ALCLs), and 12 cases of CD30-negative NHL that previously had been screened for the presence of EBV by polymerase chain reaction and DNA in situ hybridization were studied by immunohistochemistry for the expression of the latent EBV proteins, latent membrane protein (LMP), and Epstein-Barr nuclear antigen-2 (EBNA-2). We also analyzed the expression of the B-cell activation molecule CD23 and the adhesion molecules LFA-1/CD11a and ICAM-1/CD54 because the upregulation of these molecules by LMP and/or EBNA-2 in vitro has been related to the EBV-induced lymphocyte growth. Latent membrane protein expression was found in Reed-Sternberg cells in nine of 25 cases (36%) of HD and in large, occasionally Reed-Sternberg-like tumor cells in six of 47 cases (12%) of NHL; these six tumors were CD30-positive, histologically high-grade NHL (one CD30-positive ALCL and five CD30-positive non-ALCLs). All the LMP-positive cases were also polymerase chain reaction EBV positive while LMP expression was not found in polymerase chain reaction EBV-negative HD and NHL. No staining for EBNA-2 was detected in our series. In view of the transforming potential of the LMP, these findings suggest that EBV may be associated with the development of some cases of HD and CD30-positive NHL. These findings also suggest a correlation between the expression of LMP and the detection of CD30 in tumor cells of HD and NHL. In contrast, no correlation was found between the expression of LMP and the detection of CD23, LFA-1/CD11a, and ICAM-1/CD54 in tumor cells of HD and NHL.

Presence of Epstein-Barr virus harbouring small and intermediate-sized cells in Hodgkin's disease. Is there a relationship with Reed-Sternberg cells?

Forty-four cases of Hodgkin's disease (HD), mostly of the nodular sclerosing type, were investigated for the presence of Epstein-Barr virus (EBV) by polymerase chain reaction (PCR) and DNA and RNA in situ hybridization (DISH, RISH), as well as by immunohistochemistry for the detection of latent membrane protein-1 (LMP-1) of EBV. In situ hybridization (ISH) was combined with immunohistochemistry to correlate the presence and activity of the virus at the cellular level. In 18/34 (53 per cent) cases, EBV-DNA sequences could be detected with the PCR method. In 12/18 positive cases, DISH and RISH were also positive. In the remaining six EBV-PCR positive cases, two were also positive with RISH and LMP-1, whereas no positive signal with DISH could be obtained. All DISH and/or RISH positive cases were also positive for LMP-1. With RISH, not only the Reed-Sternberg cells and their mononuclear variants (RS cells) stained positive, but also small and intermediate cells frequently reacted with the EBV-specific probes (EBER-1 and -2). Double staining with cellular markers (CD3, CD20, CD45, CD45RO, CD68, and the lectin PNA) revealed that most of the smaller EBER-positive cells frequently did not express T, B, or histiocytic markers, but that they, as well as the RS cells, showed cytoplasmic and membranous staining with PNA. These smaller EBER-positive cells were not found in EBV-PCR negative HD. EBER-positive RS cells were almost always LMP-1 positive, as well as a substantial proportion of the intermediate-sized cells, whereas the majority of the small EBER-positive cells remained LMP-1 negative.(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of c-myc and bcl-2 oncogene products in Reed-Sternberg cells independent of presence of Epstein-Barr virus.

AIMS: To evaluate the expression of c-myc and bcl-2 oncogene products in Reed-Sternberg cells in Hodgkin's disease, especially in relation to Epstein-Barr virus infection and expression of EBV encoded latent membrane protein (LMP). METHODS: Tissues from 33 cases of Hodgkin's disease were studied for the presence of EBV DNA by polymerase chain reaction (PCR) and DNA in situ hybridisation (DISH), for the presence of EBER-1 and EBER-2 EBV RNA by RNA in situ hybridisation (RISH); and for the presence of LMP, bcl-2, and c-myc proteins by immunohistochemical staining. RESULTS: A substantial number of Reed-Sternberg cells expressed bcl-2 in 20 of 29 (69%) and c-myc in 30 of 32 (94%) Hodgkin's disease samples. In 18 of the 25 (72%) cases Reed-Sternberg cells expressed both oncogene products. Of these 18 cases, 10 (56%) were EBV-PCR positive; eight (44%) were EBV-PCR negative. CONCLUSIONS: Reed-Sternberg cells in Hodgkin's disease frequently express both bcl-2 and c-myc oncogene products, suggesting that these oncogenes may act in concert in the pathogenesis of the disease. Moreover, the expression of c-myc and bcl-2 proteins in Reed-Sternberg cells is independent of EBV and LMP status.

High incidence of EBV genome in CD30-positive non-Hodgkin's lymphomas.

In Hodgkin's disease, Epstein-Barr virus (EBV) is found in CD30-positive Reed-Sternberg cells. We therefore studied 60 CD30-positive non-Hodgkin's lymphomas (NHLs) for the presence of EBV by the polymerase chain reaction (PCR) and DNA in situ hybridization (DISH), and by immunohistochemistry for the latent EBV proteins LMP and EBNA-2. CD30-negative NHLs and reactive lymph nodes served as controls. The CD30-positive cases comprised 17 anaplastic large cell lymphomas (ALCLs) (> 75 per cent CD30-positive cells) and 43 non-ALCLs (with 5-35 per cent CD30-positive cells). By PCR, 40 of 60 CD30-positive NHLs (67 per cent) were EBV-positive; in CD30-negative cases, 6/29 (21 per cent) were EBV-positive, as were 12/50 (24 per cent) reactive lymph nodes. The DISH procedure demonstrated the EBV genome exclusively in the nuclei of tumour cells in 23 of the 37 PCR EBV-positive cases that were tested. PCR-negative cases were always DISH-negative, as were the PCR-positive reactive lymph nodes and CD30-negative NHLs. Immunohistochemistry demonstrated LMP in neoplastic cells of 7/47 (15 per cent) CD30-positive NHLs, both ALCL and non-ALCL always in PCR EBV-positive cases, but never in the two control groups. EBNA-2 staining could not be detected. It is concluded that EBV is present (and transcriptionally active) in a sizeable number of NHLs and an association between the presence of the EBV genome and CD30 expression seems likely.

Epstein-Barr virus DNA in Reed-Sternberg cells of Hodgkin's disease is frequently associated with CR2 (EBV receptor) expression.

We studied 44 cases of Hodgkin's disease for the presence of Epstein-Barr virus (EBV) DNA, its localization and the expression of the EBV receptor on the tumour cells. EBV DNA was found in 52% (16/31) of the Hodgkin's lymphomas using the polymerase chain reaction. With a very sensitive non-radioactive DNA in situ hybridization technique in combination with immunohistochemistry for CD 30 or CD 15 antigens, EBV DNA was localized to Reed-Sternberg cells and its mononuclear variants. The relationship between the presence of EBV DNA and the expression of the EBV-receptor CR2 (CD 21) on Reed-Sternberg cells was studied using the same techniques and two different monoclonal anti-CD 21 antibodies. CR2 could be detected on a substantial number of the Reed-Sternberg cells in EBV DNA positive Hodgkin's lymphomas (9/12; 75%), whereas in EBV negative cases positivity with anti-CD 21 was rare (1/13; 8%). The results indicate that CR2 expression on Reed-Sternberg cells and the presence of EBV DNA sequences are frequently associated in Hodgkin's lymphomas.

Application and comparison of silver intensification methods for the diaminobenzidine and diaminobenzidine-nickel endproduct of the peroxidation reaction in immunohistochemistry and in situ hybridization.

Silver-intensification methods described in the literature for the diaminobenzidine (DAB) and diaminobenzidine-nickel (DAB/Ni) endproduct of the peroxidase reaction were compared in model systems after immunoperoxidase and in situ hybridization. First, these methods were compared in immunohistochemical model systems, using the demonstration of glial fibrillar acidic protein (GFAP) and prostate-specific antigen (PSA) in paraffin sections of human brain and prostate tissue, respectively. When DAB without Ni was used as substrate, tissue argyrophilia caused considerable background staining. Only when this tissue reactivity was quenched with, e.g., CuSO4 with H2O2 or thioglycolic acid, were the results acceptable. A considerable improvement in the signal-to-noise ratio could be obtained when nickel was included in the substrate mixture. The methods that proved to be best for demonstration of GFAP and PSA made use of acid developer solutions. Subsequently, these methods were compared with other sensitive immunostaining methods for demonstration of the gamma-delta T-cell receptor in frozen lymphoid tissue. In this model a considerable increase in the number of positive cells could be obtained using silver intensification. The different methods using DAB/Ni were also compared for use in DNA in situ hybridization (DISH). In this case two model systems were used: human papilloma virus type 11 (HPV-11) DNA in condyloma tissue (abundant target model) and Epstein-Barr virus (EBV) DNA in a mononucleosis lymph node (low target model). For demonstration of HPV-11, all methods gave more or less satisfactory results, which were best with the acid developer solutions. Moreover, for demonstration of EBV DNA, a signal could be obtained only with these developer solutions. Such a method also proved suitable in double immuno-hybrido stainings for the demonstration of EBV DNA in specific antigen-positive Reed-Sternberg cells in paraffin sections of Hodgkin lymph nodes.