Biomedical subjects

Nancy L Harris

Publications and source records attributed to Nancy L Harris.

6 recordsLinked to original sources

PubMed2003

Ocular adnexal lymphoma: clinical behavior of distinct World Health Organization classification subtypes.

PURPOSE: To evaluate the clinical behavior and treatment outcome of ocular adnexal lymphomas classified by the World Health Organization system, with emphasis on marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT). MATERIALS AND METHODS: The clinicopathologic materials from 98 consecutive patients treated for ocular adnexal lymphoma were reviewed. Fourteen patients had prior lymphoma and 84 patients had primary disease (75% Stage I, 6% Stage III, and 19% Stage IV). Radiation (photons/electrons) was administered to 102 eyes to a median dose of 30.6 Gy. The mean follow-up was 82 months. RESULTS: The most common subtypes among the primary patients were MALT (57%) and follicular (18%) lymphoma. The 5-year actuarial local control rate in 102 irradiated eyes was 98%. Among the low-grade lymphomas, the 5-year local control rate correlated with the radiation dose in the MALT lymphoma subgroup (n = 53): 81% for <30 Gy and 100% for > or =30 Gy (p <0.01). For the non-MALT low-grade lymphomas such as follicular lymphoma (n = 30), the local control rate was 100% regardless of dose. For 39 Stage I MALT lymphoma patients treated with radiation alone, the distant relapse-free survival rate was 75% at 5 years and 45% at 10 years. Distant relapses were generally isolated and successfully salvaged by local therapy. The overall survival for this subgroup was 81% at 10 years, with no deaths from lymphoma. CONCLUSIONS: Dose-response data suggest that the optimal radiation dose for MALT lymphoma of the ocular adnexa is 30.6-32.4 Gy in 1.8-Gy fractions and follicular lymphoma is adequately controlled with doses in the mid-20 Gy range. The substantial risk of distant relapse in Stage I ocular adnexal MALT lymphoma underscores the importance of long-term follow-up for this disease and the need for additional comparative studies of MALT lymphoma of different anatomic sites.

Adolescent↗

PubMed2003

Pathogen discovery from human tissue by sequence-based computational subtraction.

We have recently reported a new pathogen discovery approach, "computational subtraction". With this approach, non-human transcripts are detected by sequencing cDNA libraries from infected tissue and eliminating those transcripts that match the human genome. We show now that this method is experimentally feasible. We generated a cDNA library from a tissue sample of post-transplant lymphoproliferative disorder (PTLD). 27,840 independent cDNA sequences were filtered by computational subtraction against the known human sequence to identify 32 nonmatching transcripts. Of these, 22 (0.1%) were found to be amplifiable from both infected and noninfected samples and were inferred to be human DNA not yet contained in the available human genome sequence. The remaining 10 sequences could be amplified only from Epstein-Barr virus (EBV)-infected tissues. All 10 corresponded to the known EBV sequence. This proof-of-principle experiment demonstrates that computational subtraction can detect pathogenic microbes in primary human-diseased tissue.

DNA, Complementary↗

PubMed2003

Structural analysis of the Kaposi's sarcoma-associated herpesvirus K1 protein.

The K1 protein of Kaposi's sarcoma-associated herpesvirus (KSHV) efficiently transduces extracellular signals to elicit cellular activation events through its cytoplasmic immunoreceptor tyrosine-based activation motif (ITAM). In addition, the extracellular domain of K1 demonstrates regional homology with the immunoglobulin (Ig) family and contains conserved regions (C1 and C2) and variable regions (V1 and V2). To generate mouse monoclonal antibodies directed against the KSHV K1 protein, BALB/c mice were primed and given boosters with K1 protein purified from mammalian cells. Twenty-eight hybridomas were tested for reactivity with K1 protein by enzyme-linked immunosorbent assay, immunofluorescence, flow cytometry, immunohistochemistry, and immunoblotting. Deletion mutants of the K1 extracellular domain were used to map the epitope of each antibody. All antibodies were directed to the Ig, C1, and C2 regions of K1. Furthermore, antibody recognition of a short sequence (amino acids 92 to 125) of the C2 region overlapping with the Ig region of K1 efficiently induced intracellular free calcium mobilization; antibody recognition of the other regions of K1 did not. The efficient signal transduction of K1 induced by antibody stimulation required both the ITAM sequence of the cytoplasmic domain and the normal structure of the extracellular domain. Finally, immunological assays showed that K1 was expressed during the early lytic cycle of viral replication in primary effusion lymphoma cells. K1 was readily detected in multicentric Castleman's disease tissues, whereas it was not detected in Kaposi's sarcoma lesions, suggesting that K1 is preferentially expressed in lymphoid cells. Thus, these results indicate that the conserved regions, particularly the Ig and C2 regions, of the K1 extracellular domain are exposed on the outer surface and play an important role in K1 structure and signal transduction, whereas the variable regions of K1 appear to be away from the surface.

Amino Acid Sequence↗

PubMed2003

BCL-6 expression predicts improved survival in patients with primary central nervous system lymphoma.

PURPOSE: The purpose of this study was to investigate the histogenetic origin of primary central nervous system lymphoma (PCNSL) with respect to stage of B-cell differentiation and to identify prognostic markers in a cohort of patients with PCNSL treated with i.v. high-dose methotrexate therapy. EXPERIMENTAL DESIGN: This study included 33 patients with PCNSL treated with high-dose i.v. methotrexate at the Massachusetts General Hospital for whom archival tumor tissue was available. All 33 patients tested negative for HIV. The lymphomas were morphologically subclassified according to the Kiel system, as modified in the WHO classification. Immunohistochemistry for the following antigens was performed: BCL-6; BCL-2; MUM1; CD10; vs38c; CD138; CD44; p16; and p53. Fluorescence in situ hybridization and multiplex PCR for CDKN2A/p16 were also performed. RESULTS: There were 17 women and 16 men enrolled, with a median age of 60 years. All tumors were diffuse large B-cell lymphomas. Of the 23 cases that could be subclassified, 22 were centroblastic, and 1 was immunoblastic. Twenty-six of 33 tumors were BCL-6+, 6 of 32 tumors were CD10+, 27 of 29 tumors were BCL-2+, 31 of 32 tumors were MUM1+, 11 of 31 tumors were CD44+, 4 of 33 tumors were vs38c+, and 0 of 32 tumors were CD138+. There were 18 of 32 (56%) complete responses and 8 of 32 (25%) partial responses to methotrexate, whereas 6 of 33 (18%) progressed during treatment. Ten patients died of disease. Expression of BCL-6 was significantly associated with longer overall survival (P = 0.002; median survival, 101 versus 14.7 months, with approximately 95% lower confidence limits of 41.7 and 8.8 months, respectively). CONCLUSIONS: In this group of 33 patients with PCNSL, expression of BCL-6 was significantly associated with longer overall survival. BCL-6 warrants further investigation as a potentially important prognostic marker in this disease.

Adult↗

PubMed2002

Bethesda proposals for classification of lymphoid neoplasms in mice.

A consensus system for classification of mouse lymphoid neoplasms according to their histopathologic and genetic features has been an elusive target for investigators involved in understanding the pathogenesis of spontaneous cancers or modeling human hematopoietic diseases in mice. An international panel of scientists with expertise in mouse and human hematopathology joined with the hematopathology subcommittee of the Mouse Models for Human Cancers Consortium to develop criteria for definition and classification of these diseases together with a standardized nomenclature. The fundamental elements contributing to the scheme are clinical features, morphology, immunophenotype, and genetic characteristics. The resulting classification has numerous parallels to the World Health Organization classification of human lymphoid tumors while recognizing differences that may be species specific. The classification should facilitate communications about mouse models of human lymphoid diseases.

Animals↗

PubMed2002

Posttransplant lymphoproliferative disorder associated with an Epstein-Barr-related virus in cynomolgus monkeys.

BACKGROUND: Human posttransplant lymphoproliferative disorder (PTLD) has been shown to be associated with Epstein-Barr virus (EBV) infection. Primate animal models of PTLD and the use of molecular markers in its diagnosis have not been reported. This study was designed to evaluate the frequency, pathology, and molecular characteristics of PTLD in cynomolgus kidney allograft recipients. METHODS: Over a 5-year period (January 1995 to November 2000), 160 primate renal transplants were performed at the Massachusetts General Hospital (MGH). Of these, all cases (n=9) that developed PTLD were included. H&E stained paraffin sections of all available tissue samples from the cases were evaluated for the presence of PTLD. Immunoperoxidase staining for T cells (CD3), B cells (CD20), kappa and lambda light chains as well as EBV nuclear antigens (EBNA2) and latent membrane proteins (EBV LMP-1) was done on paraffin sections using standard immunohistochemical (IHC) methods. In situ hybridization for EBV encoded RNA (EBER) was performed in all tissue samples with atypical lymphoid proliferations, using a novel EBER nucleotide probe based on consensus gene sequences from EBV and the related herpes lymphocryptoviruses (LCV) infecting baboons and rhesus macaques. RESULTS: Of 160 consecutive primate renal transplants performed at MGH, 5.6% developed PTLD 28-103 days after transplantation. In all cases, the lymph nodes were involved and effaced by an atypical polymorphous lymphoid proliferation of EBER+ B cells, diagnostic for PTLD. Focal staining for EBNA-2 was noted in tumor cells. In 67% (six of nine) the PTLD infiltrates were present in extra nodal sites, notably liver (56%), lung (44%), heart (44%), renal allograft (44%), and native kidney (22%). The spleen was involved by PTLD in all four animals that had not undergone a pretransplant splenectomy. The PTLD morphology was similar in all cases and predominantly of the polymorphous type, however, some of these showed areas that appeared minimally polymorphous. No cases of monomorphic PTLD were seen. CONCLUSIONS: By in situ hybridization, expression of the RNA product, homologous for EBV-encoded RNA (EBER) was identified in the PTLD tumor cells of all cases, indicating latent primate EBV- related infection. This report identifies a novel animal model of EBV associated PTLD in the setting of kidney transplantation, with valuable implications for managing and understanding human PTLD and oncogenesis.

Animals↗