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Biomedical subjects

K Aozasa

Publications and source records attributed to K Aozasa.

At least 91 records · Page 5Linked to original sources
PubMed1997

Epstein-Barr virus in gastric carcinoma in Suzhou, China and Osaka, Japan: association with clinico-pathologic factors and HLA-subtype.

Information on geographic differences of Epstein-Barr virus (EBV) positivity and association with HLA in gastric carcinoma are limited. Therefore, the association of gastric carcinoma with EBV was examined in 118 patients from Suzhou, China, where the incidence of nasopharyngeal carcinoma (NPC) is high, and in 216 patients from Osaka, Japan, where the incidence of NPC is low, NPC being one of the EBV-associated carcinomas. Expression of HLA-A2 was also examined in some of these cases. The EBV genome was evidenced by PCR and in the tumor cells by in situ hybridization in 7/90 and 9/151 of cases from Suzhou and Osaka, respectively. Immunohistochemistry revealed that cancer cells in all cases with EBV did not express latent membrane protein-I. Type A was found in all cases positive for EBV. Among several histologic and clinical factors, only age of patients showed a correlation with EBV positivity: patients over 60 showed a higher frequency than patients below 60 years of age (p < 0.05). Typing of the HLA-A locus was possible in 16 cases positive for the EBV genome: 3 of 4 cases from Suzhou and 4 of 7 from Osaka were positive for HLA-A2 products. Severe lymphoid cell infiltration was found in 2 of 7 cases and 1 of 4 cases with and without the HLA-A2 type, respectively. The reported frequency of EBV positivity in Chinese living in Taiwan and in Japanese living in Hawaii is higher than in Suzhou, China, and Osaka, Japan, respectively. Our findings suggest that EBV association with gastric carcinoma is influenced by environmental and cultural factors.

Adenocarcinoma↗
PubMed1997

Epstein-Barr virus in lymphoproliferative diseases in the sino-nasal region: close association with CD56+ immunophenotype and polymorphic-reticulosis morphology.

Association between Epstein-Barr virus (EBV) and nasal T-cell lymphoma (NTL) has been demonstrated. NTL has 2 types of histologic figures: one is ordinary non-Hodgkin's lymphoma (NHL) with monomorphous proliferation, and the other is polymorphic-reticulosis (PR) morphology. The presence of the EBV genome and its sub-types (A and B) were examined on paraffin-embedded specimens from 36 cases of sino-nasal lymphomas (SNL) collected from Seoul, Republic of Korea, where the frequency of NTL is high. Patients' ages ranged from 2 to 74 years (median 54 years) with a male-to-female ratio of 2.5:1. Immunophenotypically, 8 cases were B-cell type, 11 were T-cell type with CD56-, 14 were CD56+ type, and 3 were null-cell type. Five of 11 cases with ordinary NHL of T-cell type and 9 of 14 cases with PR were CD56+. The EBV genome was found by polymerase chain reaction (PCR) and in the tumor cells by in situ hybridization (ISH) in 1 of 4 B-cell type (25%), 5 of 10 T-cell type (50%), 11 of 13 CD56+ type (85%), and in both of null-cell type (100%). Of 16 cases with PR morphology, 15 (94%) were positive for the EBV genome. All of the 5 NTLs of ordinary NHL with CD56- were negative for EBV. Concerning the sub-type of EBV, 16 cases had type A, while none had type-B EBV. These findings suggest that NTL comprises 2 groups: EBV-positive NTLs are CD56+ and/or histologically PR, and EBV-negative NTLs are CD56- and histologically ordinary NHL. The current results on Korean patients, together with earlier studies on Japanese and Malaysian patients, have shown the predominance of type-A EBV in sino-nasal lymphoma in Asia.

Adolescent↗
PubMed1997

Malignant lymphoma of the kidney.

BACKGROUND: Primary renal lymphoma (PRL) is a rare disease, making information including etiologic factors for PRL extremely limited. METHODS: Clinical and pathologic findings of PRL in Japan are presented and compared with those from Western countries. The presence of Epstein-Barr virus (EBV) genomes in the tumor was also evaluated. Eight cases of PRL were collected from a review of the "Annual of the Pathological Autopsy Cases in Japan (1976-1992)". These cases fulfilled the following criteria: (1) presence of renal mass without extrarenal lymphomatous involvement at admission and (2) absence of a leukemic blood picture. For histologic and immunohistochemical studies, 10% formalin-fixed and paraffin-embedded histologic specimens were used. Presence of Epstein-Barr virus (EBV) genome was examined by polymerase chain reaction (PCR) and in situ hybridization (ISH). RESULTS: There were five males and three females; age at admission ranged from 15 to 79 years (median 57 yr). Abdominal and/or flank pain were the most common presenting symptoms. No particular past history was present in any of the patients. Histologically, tumor cells in all cases showed a diffuse pattern of proliferation: large cell type in six cases, mixed cell type and small lymphocytic type in 1 each. Immunohistochemistry revealed B-cell nature of lymphoma cells in all cases. Neither PCR nor ISH showed the presence of EBV genome in any cases. CONCLUSIONS: PRL is non-Hodgkin's lymphoma of predominantly large cell type with a B-cell immunophenotype. EBV etiology is unlikely in PRL.

Adolescent↗
PubMed1997

Tumor size as a prognostic indicator of histologic grade of soft tissue sarcoma.

BACKGROUND AND OBJECTIVES: Tumor size is one of the independent factors affecting prognosis of patients with soft tissue sarcoma (STS). We evaluated the significance of tumor size in combination with tumor depth in each histologic grade. METHODS: A total of 162 adult patients with localized STS in the extremities and trunk were selected. Patient ages ranged from 15 to 84 (median 46.5) years with a male-to-female ratio of 1.19. Histologic grade of tumors was low in 53 cases, intermediate in 51, and high in 58. Two types of categorization were set, and their significance in predicting the prognosis of patients in each grade was evaluated. In the first category (intermediate grade), tumors were dichotomized at 10 cm: Group A comprised patients with deeply seated tumors measuring > 10 cm; Group B comprised patients other than those in Group A. In the second category (high grade), tumors were dichotomized at 5 cm: Group C comprised patients with deeply seated tumors measuring > 5 cm; Group D comprised patients other than those in Group C. RESULTS: Categorization was not useful in the prognosis of low grade tumors. In the intermediate grade group, the 5-year-survival rate of Group B patients (78%) was higher than in Group A patients (59%) (P < 0.05), showing that dichotomization at 10 cm was useful. In the high grade group, the 5-year survival rate in Group C patients (32%) was lower than in Group D patients (56%), showing that dichotomization at 5 cm was useful. CONCLUSIONS: These findings show that tumor size for the prognosis of patients with STS differs according to each histologic grade.

Adolescent↗
PubMed1997

Epstein-Barr virus in malignancies in renal transplant recipients in Japan.

A role for Epstein-Barr virus (EBV) in the development of malignancies including lymphomas, and carcinoma of the stomach, nasopharynx, thymus and salivary gland is suggested. It is indicated that EBV evokes polyclonal-B-cell-proliferative diseases in immunocompromised hosts, such as transplant patients, which results in monoclonal malignant lymphomas. The suppression of immune functions in these patients is thought to lead to incomplete elimination of the cells expressing EBV latent infection genes. To examine the etiological role of EBV in the development of malignancies following renal transplant in Japan, 42 malignancies in 1744 cases of renal transplant were studied for the presence and type of EBV. The polymerase chain reaction revealed that 5 malignancies were positive for EBV, all type A: 2 of 2 cases of non-Hodgkin's lymphoma (NHL), 2 of 8 cases of gastric adenocarcinoma of the common type, and 1 of 2 cases of gastric plasmacytoma. In situ hybridization revealed positive signals in the nucleus of tumor cells in 2 cases of NHL and 1 of plasmacytoma. Positive signals were found in the small lymphoid cells but not in the tumor cells in 2 cases of gastric carcinoma. On the basis of these findings, a role for EBV in the development of malignancies in renal transplant patients is unlikely except for lymphoid neoplasias.

Adolescent↗
PubMed1997

P-glycoprotein expression in soft-tissue sarcomas.

Multidrug resistance (MDR) is an important problem in chemotherapy for neoplastic disease. In humans. MDR is mainly mediated by P-glycoprotein (P-gp) a product of the MDRI gene, which acts as a transmembrane protein pump and eliminates chemotherapeutic agents from the cells. Expression of P-gp was immunohistochemically studied by using two monoclonal antibodies, JSB-1 and C-219, on paraffin-embedded sections from 55 patients with soft-tissue sarcoma. The histological diagnosis of tumors was malignant fibrous histiocytoma in 24 cases, liposarcoma in 9, synovial sarcoma in 7, malignant neurogenic tumors in 6, leiomyosarcoma in 5, others in 4. The histological grade was determined on the basis of criteria previously proposed by us. Out of 55 cases, 34 (62%) were positive for P-gp expression. There was a significant difference in P-gp expression between high-grade (90%) and intermediate and low-grade tumors (46%) (P < 0.005). Tumors expressing P-gp had a less favorable prognosis than P-gp-negative tumors in the high- and intermediate-grade tumors. The current study demonstrated that the estimation of P-gp expression could be used to select appropriate therapeutic modalities.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1997

Focal encephalitis mimicking malignant lymphoma of the central nervous system.

We present a case of subacute focal encephalitis in a 62-year-old man whose clinical manifestations, neuroradiological findings and histopathological features mimicked those of a patient with malignant lymphoma of the central nervous system (CNS). In addition to routine histopathological examination, extensive studies including serological examination for encephalitic viruses, immunohistochemistry and DNA analysis were required to distinguish focal encephalitis from lymphoma of the CNS, clinical entities which differ in treatment.

Acyclovir↗
PubMed1997

Production of the immunosuppressive cytokine interleukin-10 by Epstein-Barr-virus-expressing pyothorax-associated lymphoma: possible role in the development of overt lymphoma in immunocompetent hosts.

Malignant lymphomas frequently develop in the pleural cavity of patients with long-standing pyothorax. Thus, the term pyothorax-associated lymphoma (PAL) has been proposed for this type of tumor. Most PALs are diffuse lymphomas of B cell type and contain Epstein-Barr virus (EBV) DNA. We have established two lymphoma cell lines from the biopsy specimens of PAL cases, OPL-1 and OPL-2. Both cell lines contain EBV DNA, but only OPL-1 expresses EBV nuclear antigen 2, which works as a target molecule for the cell-mediated immune response. As systemic immunodeficiency is unlikely to be present in PAL patients, PAL from which OPL-1 derived was not expected to be fully developed. In this study, we examined the expression of immunosuppressive factors in OPLs. Only OPL-1, not OPL-2, expressed interleukin-10 (IL-10) mRNA and secreted IL-10 into culture supernatant. Both OPL-1 and OPL-2 expressed transforming growth factor (TGF)-beta 1 mRNA; however, neither expressed latent TGF-beta-binding protein mRNA at a detectable level by Northern blot analysis. Because TGF-beta expresses its functions in cooperation with latent TGF-beta-binding protein, the biological functions of TGF-beta 1 could be negligible. Neither cell line expressed at a detectable level EBV BCRF-1 mRNA, a viral gene product that is partly homologous to human IL-10 and shares biological activities of IL-10. Although IL-10 is reported to promote the growth of activated or neoplastic B cells, OPL-1 did not respond to human recombinant IL-10 by growing faster. As OPL-1 expresses a target antigen for the host cytotoxic T-cell response, the production of an immuno-suppressive cytokine, IL-10, might contribute to the development of overt lymphoma by inducing locally immunosuppressive circumstances. The present study suggests that an immunosuppressive cytokine plays a role in lymphomagenesis of immunocompetent patients.

Animals↗
PubMed1997

[Pyothorax-associated lymphoma: EBV-positive lymphoma developing in immunocompetent patients].

Malignant lymphomas frequently develop in the pleural cavity of patients with long-standing pyothorax. Thus, the term pyothorax-associated lymphoma (PAL) has been proposed for this type of tumor. Most of PALs are diffuse lymphomas of B cell type and contain Epstein-Barr virus (EBV) DNA. We established two lymphoma cell lines from biopsy specimens of PAL cases, and examined their growth characteristics and the expression of EBV latent infection genes and oncogenes. The differences in growth rate and oncogene expression between the lines could not be adequately explained by the pattern of EBV latent gene expression. The subsequent genetic lesions might be necessary for the development of overt lymphoma. Furthermore, the mechanism of development of viral antigen-positive tumor in immunocompetent patients is discussed.

Empyema, Pleural↗
PubMed1997

Role of an immunosuppressive cytokine, interleukin-10, in the development of pyothorax-associated lymphoma.

Malignant lymphoma frequently develops in the pleural cavity of the patients with long-standing pyothorax. Thus, the term pyothorax-associated lymphoma (PAL) has been proposed for this type of tumor. Most of PALs are diffuse lymphoma of B cell type and contain Epstein-Barr virus (EBV) DNA. We have established two lymphoma cell lines from the biopsy specimens of PAL cases, OPL-1 and OPL-2. Both cell lines contain EBV DNA, but only OPL-1 expresses Epstein-Barr virus nuclear antigen 2 (EBNA2) that works as a target molecule for cell-mediated immune response. In this study, we examined the expression of immunosuppressive factors in OPLs. Only OPL-1, not OPL-2, expressed interleukin-10 (IL-10) mRNA and secreted IL-10 into culture supernatant. Both OPL-1 and OPL-2 expressed transforming growth factor (TGF) beta 1 mRNA, however, neither expressed latent TGF beta binding protein (LTBP) mRNA at detectable level by Northern blot analysis. Because TGF beta expresses its functions in cooperation with LTBP, the biological functions of TGF beta 1 could be negligible. Neither cell lines expressed EBV BCRF1 mRNA at detectable level, a viral gene product which is partly homologous to human IL-10 and shares biological activities of IL-10. Since OPL-1 shows weaker proliferative activity than OPL-2 and expresses viral antigens, the production of an immunosuppressive cytokine, IL-10, might contribute to the development of overt lymphoma. The present study suggested that immunosuppressive cytokine plays a role in lymphomagenesis of immunocompetent patients.

DNA, Viral↗
PubMed1997

Non-Hodgkin's lymphoma of Waldeyer's ring as a manifestation of lymphoproliferative diseases associated with human T-cell leukemia virus type 1 in southwestern Japan.

Adult T-cell leukemia/lymphoma (ATL) usually presents with node- and/or cutaneous-based diseases, with a leukemic picture. It is not clear whether ATL initially manifests with lesions in Waldeyer's ring (WR) in an ATL-endemic area. In the present study, we examined distributions of immunophenotypes and the presence of human T-cell leukemia virus type 1 (HTLV-1) and Epstein-Barr virus (EBV) genomes in 62 cases of non-Hodgkin's lymphoma (NHL) of WR (NHL-WR) from two areas of Japan: Osaka, an ATL-nonendemic area (25 cases), and Okinawa, an ATL-endemic area (37 cases). In both areas, age ranged from 10 to 94 years (median, 64 yr), with a male-to-female ratio of 1.81:1. Twelve patients were in Stage I, 34 in Stage II, and 6 in Stage III; stage was unknown in 10. The 25 Osaka cases were B-cell type (16 diffuse immunoblastic type (DIB), 8 diffuse large cell predominantly noncleaved cell (DLNC), 1 cleaved cell (DLC)). Of the 37 Okinawa cases, 20 were B-cell type (3 DIB, 10 DLNC, 2 DLC, 5 other). The remaining 17 cases showed T-cell phenotype (4 DIB, 3 DLC, 3 diffuse large cell not otherwise specified, 7 other). There was a significant difference in the distribution of immunophenotypes between these two areas (P < .001). Combined studies of polymerase chain reaction (PCR) and in situ hybridization revealed the presence of EBV genome in 1 (4%) of 24 Osaka cases, 2 (13%) of 16 B-cell NHLs from Okinawa, and 3 (23%) of 13 T-cell NHLs from Okinawa. HTLV-1 proviral genome was found in 11 (85%) of 13 T-cell lymphomas from Okinawa but could not be detected in B-cell lymphomas from Osaka and Okinawa. Combined clinical, histologic, serologic, and PCR findings suggest that NHL-WR in an ATL-endemic area could be an initial manifestation of ATL.

Adolescent↗
PubMed1997

Alterations of the p53 gene in occupational bladder cancer in workers exposed to aromatic amines.

Epidemiologic studies have revealed an increased risk for development of transitional cell carcinoma (TCC) among dye workers/painters occupationally exposed to aromatic amines such as benzidine, beta-naphthylamine, orthotoluidine, and aniline. In the present study, p53 gene mutations in 26 patients with bladder lesions occupationally exposed to aromatic amines were examined by single-strand conformation polymorphism analysis of PCR-amplified DNA segments, followed by direct sequencing. All were male, and age at admission ranged from 43 to 75 (median 66) years. Twenty-nine biopsy specimens were from primary lesions; 17 (61%) of these lesions were from TCC including one carcinoma in situ (CIS); 11 were from dysplasia; and 1 was taken from normal-looking transitional epithelium adjoining TCC. TCC lesions included 12 with low-grade (Grade 1 or 2) and 5 with high-grade (Grade 3 or CIS) changes. Twenty-four recurrent lesions were biopsied in 16 patients: TCC was found in 12 lesions (50%), CIS in 1 (4%), and dysplasia in 11 (46%). All lesions were localized within the submucosa except for two, which invaded into the muscle layers. PCR-single-strand conformation polymorphism analysis demonstrated that mutations (a) occurred in both dysplasia and in normal-looking epithelium, in addition to TCC lesions; (b) were at different sites in the p53 gene in concurrent or metachronous lesions; and (c) occurred in exon 5 in approximately 70% of lesions, especially at codons 151 and 152. C to T transitions were predominantly seen. These findings clearly show differences in the pattern of p53 mutation in occupational versus nonoccupational bladder lesions. Because both common and unique point mutations were found in p53 in concurrent and metachronous lesions, our results suggest that the multifocality of occupational bladder cancer arises both from multiple clonal lesions (field change) and from the dissemination of a single clone.

Adult↗
PubMed1996

Expression of Epstein-Barr virus latent infection genes and oncogenes in lymphoma cell lines derived from pyothorax-associated lymphoma.

Malignant lymphomas frequently develop in the pleural cavity of patients with long-standing pyothorax. The term pyothorax-associated lymphoma (PAL) has been proposed for this type of tumor. Most PALs are diffuse lymphomas of the B-cell type and contain Epstein-Barr virus (EBV) DNA. We have established 2 lymphoma cell lines from biopsy specimens of PAL cases, OPL-1 and OPL-2, and examined their growth characteristics and the expression of EBV latent infection genes and oncogenes. OPL-2 exhibited a more rapid growth and higher saturation density than OPL-1, and only OPL-2 exhibited colony-forming activity in soft agar. OPL-1 and -2 were positive for B-cell differentiation markers and showed clonal surface immunoglobulins. Both line contained a single predominant form of episomal EBV DNA, indicating clonal cellular proliferation of an EBV-infected progenitor cell. OPL-1 and -2 contained type B and A EBV genome, respectively. Expression of EBV nuclear antigen (EBNA)2 mRNA and protein was detected by Northern and Western blot analysis in OPL-1, but not in OPL-2. On the other hand, the expression of latent membrane protein (LMP)1 mRNA in both OPL-1 and -2 was extremely weak and detectable only by reverse transcription-polymerase chain reaction. Protein expression of LMP1 was not observed by Western blot analysis or immunocytochemistry. Both lines expressed c-myc mRNA. Only OPL-1 expressed mRNA of c-fgr, an oncogene whose expression is upregulated by EBNA2. Both OPLs expressed bcl-2 mRNA without detectable expression of LMP1 protein.

Aged↗
PubMed1996

Histologic changes in small cell lung carcinoma after treatment.

BACKGROUND: Small cell lung carcinoma (SCLC) has been divided into three subtypes: pure SCLC, mixed small cell/large cell carcinoma (mixed SC/LC), and combined SCLC. Patients with mixed SC/LC show a worse prognosis than those with pure SCLC. METHODS: Persistence of histologic subtype in SCLC in the primary sites during the course of treatment or in the different organs at autopsy was examined. For this purpose, biopsy or cytologic specimens before chemotherapy, and autopsy specimens from 175 patients with SCLC were reviewed. They included 147 (84%) men and 28 (16%) women with an age range of 29-83 (median, 65) years. RESULTS: The frequency of mixed SC/LC in the primary sites was statistically higher in autopsy (14.3%) than that in biopsy or cytology specimens (8.6%) (P < 0.05). At autopsy, involved organs were categorized into two groups according to frequency of appearance of mixed SC/LC, i.e., a higher frequency group, including the liver (31 of 85; 36.4%), adrenal gland (15 of 56; 26.8%), brain (6 of 9; 66.7%), and extrathoracic lymph nodes (17 of 59; 28.8%) and a lower frequency group, including the lung (metastatic sites) (12 of 102; 11.8%), pleura (8 of 74; 10.8%), and intrathoracic lymph nodes (12 of 94; 12.8%). The difference in frequency between these two groups was statistically significant (P < 0.05). CONCLUSIONS: These findings suggest that primary pure SCLC can progress to mixed SC/LC with an increased potential for distant metastasis.

Adult↗
PubMed1996

Epstein-Barr virus in Hodgkin's disease patients in Japan.

BACKGROUND: The association of Epstein-Barr virus (EBV) and Hodgkin's disease (HD) has been suggested by serologic, epidemiologic, and molecular biologic studies. The high level of EBV association with HD in the developing countries was discussed in relation to the high HD incidence in these areas. Japanese HD shows a distinct peak incidence in older adults. In contrast, Western HD shows a bimodal pattern, the first peak in young adulthood and a second peak in older patients. In the present study, the EBV association with HD in Japan was investigated, and the results were compared with those reported from industrialized and developing countries. METHODS: Fifty-seven patients with HD were studied for the presence or absence of the EBV genome by the polymerase chain reaction and in situ hybridization methods. Seven cases were excluded from the analysis for EBV because of poor preservation of nucleotides in the specimens. RESULTS: EBV genomes were detected in the Reed-Sternberg (R-S) cells of 32 of the 50 patients examined (64%). The EBV association was independently affected by histologic subtype (84% in mixed cellularity and 44% in others), sex (76% in males and 31% in females), and age (76% in patients aged 40 years and older and 38% in patients younger than 40 years of age; P < 0.01). High EBV association is found at the peak in older adults predominantly with mixed cellularity type. Previous studies revealed that the high EBV was associated with the older peak of the bimodal peaks in Western HD, and a unimodal peak in childhood in developing countries. The EBV subtype was predominantly type A, which is identical to the immunocompetent type of HD reported previously. CONCLUSIONS: The results of the current study, together with those reported previously, showed that the presence of the Epstein-Barr virus correlated with mixed cellularity type, age older than 40 years, and male sex.

Adolescent↗