Partial amino acid sequences of soybean lipoxygenase L-6 isolated from cotyledons.
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Biomedical subjects
Publications and source records attributed to D Shibata.
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We have investigated seven cases of large cell lymphomas (LCL) developing simultaneously or metachronously to nodular lymphocyte-predominant Hodgkin's disease (nodular paragranuloma, NP) for the presence of EBV and the chromosomal translocation t(14;18) by use of the polymerase chain reaction (PCR). The expression of the bcl-2 oncogene product in these cases and in five cases of progressive transformation of germinal centres as a potential precursor of NP was detected immunohistochemically with the monoclonal antibodies bcl-2-100 and bcl-2-124. All cases investigated were negative for EBV genomic material. The chromosomal translocation t(14;18) was also absent. Expression of the bcl-2 oncogene could be detected only in one case of nodular paragranuloma and in an unrelated case of LCL. Hence, LCL developing out of NP differ from other germinal center derived high-grade lymphomas.
The Epstein-Barr virus (EBV) has been detected in certain types of lymphoma and some epithelial neoplasms including nasopharyngeal lymphoepithelioma, and rare lymphoepithelioma-like carcinomas occurring in a variety of organs including, most recently, the stomach. The authors investigated the possibility that EBV may be present not only in the rare gastric cancers that resemble nasopharyngeal lymphoepithelioma, but also in typical gastric adenocarcinoma. EBV sequences were detected in 22 of 138 (16%) cases of typical gastric adenocarcinoma by polymerase chain reaction and in situ hybridization (ISH) techniques. The EBV genomes were specifically present within the gastric carcinoma cells in an even distribution. The EBV genomes were also present in adjacent dysplastic epithelium but were absent in surrounding lymphocytes, other normal stromal cells, intestinal metaplasia, and normal gastric mucosa. The EBV genomes in the infected gastric carcinoma cells are expressed as EBV RNA was detected by ISH. EBV was most often detected in gastric tumors from men (21%) compared with women (3%). Thus some cases of gastric adenocarcinoma are EBV-associated.
PCR was used to screen EBV-positive lymphomas from endemic and sporadic Burkitt's lymphoma patients, including EBV-positive lymphomas derived from patients with HIV infection. Only 10% of sporadic lymphomas from either North America (1/15) or South America (2/14) were associated with the type 2 EBV strain, whereas 50% (8/16) of lymphomas from equatorial Africa and 46% (10/22) of HIV-associated lymphomas were positive for the type 2 strain. These data, in conjunction with previous reports, suggest that the proportions of strain types in Burkitt's lymphoma reflect the proportions of strain types in peripheral lymphocytes, and not simply the prevailing regional strain. The increased association of the type 2 strain in lymphocytes and lymphomas from HIV-infected individuals and from Africa may be a result of intermittent (malaria) or continuous (HIU) compromise of immune function in these populations.
A method using selective ultraviolet radiation fractionation followed by polymerase chain reaction (PCR) can analyze specific cell subsets present on a microscope section. Direct ultraviolet radiation of fixed and stained tissue sections prevents subsequent amplification by PCR. An "umbrella" or dot placed physically over small numbers of pure cell populations selected by microscopic examination protects these cells from the ultraviolet inactivation. The DNA in these protected cells can be specifically amplified while no signal is derived from the unprotected surrounding cells. Specific amplification was demonstrated by detecting human papillomavirus sequences only if infected cells were protected. Similarly, loss of heterozygosity at the p53 locus was documented by selective dotting of normal or tumor cells. The method allows the specific and sensitive molecular genetic analysis of small numbers of cells histologically identified and selected under the microscope.
The authors describe a highly sensitive and practical in situ hybridization method using an oligonucleotide probe for EBER1 RNA for the detection of Epstein-Barr virus (EBV) in formalin-fixed, paraffin-embedded tissue sections. Paraffin-embedded tissues from 793 cases of normal and neoplastic tissues were studied. Nuclear staining for EBV RNA was uniformly present in all or virtually all neoplastic cells in a variety of known EBV-positive tumors. We also demonstrate rare EBV-infected cells in normal lymphoid tissues. RNAase predigestion, competitive inhibition, and control probe studies confirmed the specificity of the staining. In addition, cross-reactivity of EBV RNA staining with other viruses was not present. Additionally, the distribution of EBV in a wide variety of other normal and neoplastic tissues is reported.
A highly sensitive in situ hybridization methodology for Epstein-Barr virus (EBV) RNA was used to determine the topography of EBV infection in 16 cases of human immunodeficiency virus-associated lymphoid tissues. Four lymphomas, 11 persistent generalized lymphadenopathy (PGL) lymph nodes, and one lymphoepithelial cyst were studied. The pattern of EBV infection was diffuse in all lymphoma cases and predominantly interfollicular in PGL nodes. No discernable pattern of infection was present in the lymphoepithelial cyst. Germinal center cells were also infected in seven of the PGL cases, and this pattern predominated in one case. Double labeling immunohistochemistry/in situ hybridization studies on four cases of PGL indicated that the EBV infection was primarily involving B-lymphocytes, but rare infected T-lymphocytes were also identified. These studies further clarify the pattern and cellular site of EBV infection in human immunodeficiency virus-related lymphoid disease.
Individuals infected with the human immunodeficiency virus (HIV) have an increased incidence of high-grade B-cell lymphoma. In many instances, these lymphomas contain Epstein-Barr viral (EBV) genomes. To investigate the role of EBV in development of HIV-related lymphoma, benign fixed lymph node biopsies from normal individuals and HIV-infected individuals with persistent generalized lymphadenopathy (PGL) were analyzed for EBV sequences by polymerase chain reaction and in situ DNA hybridization techniques. EBV DNA was not detected in any of 16 benign lymph node biopsies from normal individuals, but could be detected from 13 of 35 PGL biopsies. The EBV-infected cells were present in both follicular and interfollicular areas and in both small and large lymphoid cells. The presence of detectable amounts of EBV DNA in the 13 PGL biopsies was associated with an increased incidence of concurrent lymphoma at another site (n = 3) or development of lymphoma in time (n = 2). In contrast, only 1 of 22 individuals with EBV-negative PGL biopsies developed lymphoma in time (P less than .05). EBV was detected in all five lymphomas in which tissue was available for subsequent analysis, including the lymphoma that developed in the individual without EBV in his previous PGL biopsy. These findings support the hypothesis that EBV plays a role in development of some HIV-related lymphomas. Detectable EBV lymphoproliferations occur in a few PGL biopsies and are associated with a significant risk of EBV DNA-positive non-Hodgkin's lymphoma.
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Epstein-Barr viral (EBV) infections are associated with Hodgkin's disease (HD). To better characterize this relationship, fixed tissues of infectious mononucleosis, normal and reactive lymph nodes, lymph nodes with progressively transformed germinal centers, and biopsy specimens with the different subtypes of HD were analyzed by polymerase chain reaction (PCR). The presence or absence of EBV, the relative amounts of EBV, and the presence of multiple EBV genotypes as defined by amplification of a polymorphic EBV locus were determined for each specimen. Epstein-Barr virus could be detected from all specimens with infectious mononucleosis (eight of eight cases), generally in relatively large amounts, with multiple EBV genotypes evident in two cases. Epstein-Barr virus could not be detected from normal or reactive lymph nodes (none of 39 cases). Small amounts of EBV could be detected from a minority of cases with progressively transformed germinal centers (two of 16 cases), with multiple EBV genotypes evident in one case. Variable amounts of EBV could be detected from approximately half of the specimens with HD (26 of 50 cases). Epstein-Barr virus was most often detected in the subtypes of mixed cellularity (12 of 15 cases), nodular sclerosis (seven of 14 cases), and lymphocyte depletion (five of seven cases) compared with nodular lymphocyte predominance HD (two of 14 cases). In contrast to specimens with infectious mononucleosis and progressively transformed germinal centers, only one EBV genotype was evident in the specimens with HD. These findings are consistent with the hypothesis that some cases of HD may be directly associated with EBV.
Fixed lymphoma tissues from 11 patients seropositive for human T-cell leukemia virus type I (HTLV-I) antibodies were analyzed for proviral sequences by the polymerase chain reaction. Typical adult T-cell leukemia/lymphomas (ATLLs) from nine patients were positive for HTLV-I sequences. In contrast, one of two lymphomas with immunophenotypes atypical for ATLL was negative for HTLV-I. This HTLV-I DNA-negative lymphoma, although present in an HTLV-I-seropositive patient, was therefore reclassified. The HTLV-I tax gene was always detected in the ATLL tissues, whereas segments of the pol gene were not detected in half the cases. These studies demonstrate that fixed non-ATLL specimens can be distinguished from ATLL specimens.
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An important question in feline leukemia virus (FeLV) pathogenesis is whether, as in murine leukemia virus infection, homologous recombination between the infecting FeLV and the noninfectious endogenous FeLV-like proviruses serves as a significant base for the generation of proximal pathogens. To begin an analysis of this issue, several recombinant FeLVs were produced by using two different approaches: (i) the regions of the viral envelope (env) gene of a cloned FeLV (subgroup B virus [FeLV-B], Gardner-Arnstein strain) and those of two different endogenous proviral loci were exchanged to create specific FeLV chimeras, and (ii) vectors containing endogenous env and molecularly cloned infectious FeLV-C (Sarma strain) DNA sequences were coexpressed by transfection in nonfeline cells to facilitate recombination. The results of these combined approaches showed that up to three-fourths of the envelope glycoprotein (gp70), beginning from the N-terminal end, could be replaced by endogenous FeLV sequences to produce biologically active chimeric FeLVs. The in vitro replication efficiency or cell tropism of the recombinants appeared to be influenced by the amount of gp70 sequences replaced by the endogenous partner as well as by the locus of origin of the endogenous sequences. Additionally, a characteristic biological effect, aggregation of feline T-lymphoma cells (3201B cell line), was found to be specifically induced by replicating FeLV-C or FeLV-C-based recombinants. Multiple crossover sites in the gp70 protein selected under the conditions used for coexpression were identified. The results of induced coexpression were also supported by rapid generation of FeLV recombinants when FeLV-C was used to infect the feline 3201B cell line that constitutively expresses high levels of endogenous FeLV-specific mRNAs. Furthermore, a large, highly conserved open reading frame in the pol gene of an endogenous FeLV provirus was identified. This observation, particularly in reference to our earlier finding of extensive mutations in the gag gene, reveals a target area for potentially productive homologous recombination upstream of the functional endogenous env gene.
Some undifferentiated gastric carcinomas with intense lymphoid infiltration have a striking resemblance to nasopharyngeal lymphoepithelioma. The authors identified eight such cases (seven patients from Japan and one from the United States) of undifferentiated gastric carcinoma (lymphoepithelioma-like carcinoma [LELC]) and examined them for Epstein-Barr (EBV) viral sequences using polymerase chain reaction (PCR) and in situ hybridization (ISH) techniques. EBV was detected in seven of the eight cases by PCR, including a lymph-node metastasis. ISH that was performed in six of these cases showed EBV genomes to be uniformly present in the carcinoma cells and not present in the reactive lymphoid infiltrate or normal gastric mucosa. PCR of a polymorphic EBV locus (lymphocyte-determined membrane antigen) showed that a single genotype was present in each gastric LELC, consistent with a clonal process. These findings suggest that some undifferentiated gastric carcinomas are EBV-related and that focal EBV infection occurs before transformation.
The authors studied typical Hodgkin's disease along with the nodular, lymphocyte predominance subtype by both the polymerase chain reaction (PCR) and in situ hybridization for evidence of the Epstein-Barr virus (EBV). By PCR, EBV DNA was detected in 12/23 cases of typical Hodgkin's disease and 2/13 cases of the nodular, lymphocyte predominance subtype. EBV RNA was detected by in situ hybridization studies within Reed-Sternberg cells and variants in 11/23 cases of typical Hodgkin's disease and 0/13 cases of nodular, lymphocyte predominance Hodgkin's disease. Other cells positive for EBV, identified as both B and T cells in double-labeling immunohistochemical/in situ hybridization studies, were found in 20/23 cases of typical Hodgkin's disease, 9/13 cases of nodular, lymphocyte predominance Hodgkin's disease, 4/6 cases of progressive transformation of germinal centers, and 7/10 normal lymphoid tissues. It is concluded that EBV is significantly associated with Reed-Sternberg cells in approximately one-half cases of typical Hodgkin's disease but not in the nodular, lymphocyte predominance subtype. EBV-infected B and T cells are also present in a majority of cases of Hodgkin's disease as well as in reactive conditions.
Polymorphic genetic loci of the deoxyribonucleic acid (DNA) present in formalin-fixed, paraffin-embedded tissues were successfully analyzed by utilizing the polymerase chain reaction. Using this analysis, with three different polymorphic loci [human leucocyte antigen (HLA) DQ alpha, low-density lipoprotein receptor, and parathyroid hormone], fixed tissues representing 14 different individuals were genotyped and could be distinguished from each other. The techniques were further applied to the fixed autopsy tissues of a man in which a question of paternity arose postmortem. Since many individuals have surgical procedures or autopsy, these readily available fixed tissues represent an additional resource for the identification of individuals.