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Biomedical subjects

K Sakamoto

Publications and source records attributed to K Sakamoto.

At least 1,081 records · Page 60Linked to original sources

The Epstein-Barr virus in the pathogenesis of posttransplant lymphoproliferative disorders. Clinical, pathologic, and virologic correlation.

Twelve renal transplant patients with lymphoproliferative disorders (LPDs) were studied. Two clinical patterns were identified: (1) Young patients present with an infectious mononucleosis-like illness with fever, sore throat, and lymphadenopathy soon after transplantation or antirejection therapy. Many organs are ultimately involved, and the clinical course is one of a rapidly fatal LPD. (2) Older patients present a longer time after transplantation with symptoms of solid tumors involving the central nervous system, oropharynx, liver, or small bowel. The clinical course is slower, but it is progressive and fatal. Morphologically these LPDs can all be classified as polymorphic diffuse B-cell hyperplasia (PDBH) or polymorphic diffuse B-cell lymphoma (PBL). Cell marker studies in four patients demonstrated a polyclonal B-cell proliferation. Transition from a polyclonal B-cell proliferation to a monoclonal tumor may occur. Epstein-Barr virus (EBV) specific antibody titers, anticomplement immunofluorescence staining of tumors for the presence of the Epstein-Barr nuclear antigen (EBNA), and EBV complementary ribonucleic acid (cRNA)/deoxyribonucleic acid (DNA) hybridization and vDNA/DNA reassociation analysis implicate EBV as the probable etiologic agent in these disorders. Successful management of these lethal LPDs may depend on discontinuation of immunosuppression and removal of the allograft. Antiviral therapy, however, may prove to be useful.

Adolescent↗

Documentation of Epstein-Barr virus infection in immunodeficient patients with life-threatening lymphoproliferative diseases by clinical, virological, and immunopathological studies.

Multiple methods, pedigree analysis, clinical evaluation, and Epstein-Barr virus (EBV)-specific serology, EBV DNA hybridization of tissues to probe for viral genome, staining of touch imprints for EBV nuclear-associated antigen, establishment of spontaneous infected B-cell lines from peripheral blood or tissues, examination of peripheral blood smears, and hematopathology studies, were used to study seven patients with the X-linked lymphoproliferative syndrome and seven additional patients with life-threatening EBV-associated diseases. These studies demonstrated EBV in the tissues of all 14 patients and immunodeficient antibody responses to EBV were documented. This virus can produce various life-threatening lymphoproliferative diseases in a variety of immunodeficient patients.

Adolescent↗

Documentation of Epstein-Barr virus infection in immunodeficient patients with life-threatening lymphoproliferative diseases by Epstein-Barr virus complementary RNA/DNA and viral DNA/DNA hybridization.

Tissues from patients thought to have Epstein-Barr virus (EBV)-induced lymphoproliferative diseases were probed for EBV genomes using 2 independent hybridization techniques. Tissues from six patients with the X-linked lymphoproliferative syndrome, all five renal allograft recipients with immunoblastic sarcoma, and eight patients with diverse types of immunodeficiency and lymphoproliferative diseases such as fatal infectious mononucleosis or malignant lymphoma associated with antecedent immunodeficiency contained significant numbers of EBV genome equivalents per cell. The use of 2 hybridization probes is recommended to confirm the presence of EBV genomes. The finding of significant numbers of EBV genomes in tissues from patients with immunodeficiency suggests that EBV is the etiological agent of the associated lymphoproliferative diseases.

Adolescent↗

Diverse familial malignant tumors and Epstein-Barr virus.

Continued monitoring of a family for new malignant tumors has revealed diverse immunological and neoplastic disorders during a 15-year period. In 1966, the proband developed lymphoma. In 1975, his antibody titers to Epstein-Barr virus (EBV) became elevated, and again, he developed a malignant lymphoma. He also had borderline hypo-immunoglobulin A, died of glioblastoma multiforme in 1977, and at autopsy, had adenomatous colonic polyps. His eldest brother has normal immunoglobulin levels, but developed immune thrombocytopenia in 1973 and had elevated EBV antibody titers in 1980. Another brother had hypo-immunoglobulin A, thymoma in 1965, and adenomas and adenocarcinoma of the colon. Two other brothers succumbed to glioblastoma in 1968 and 1969. The father of the proband had bronchiectasis in 1952, hypo-immunoglobulin M documented in 1972, and elevated EBV antibody titers 5 years preceding development of a malignant lymphoma. The latter contained 10 EBV genome equivalents/cell by EBV viral DNA/DNA reassociation kinetics analysis. The proband's grandmother had died of an immunoglobulin G-secreting myeloma in 1977, and his grandfather had borderline low immunoglobulin M, elevated EBV antibody titers, and hypopharyngeal carcinoma in 1980. Predisposition to oncogenesis in this family was probably inherited.

Adenocarcinoma↗

Clinical spectrum of lymphoproliferative disorders in renal transplant recipients and evidence for the role of Epstein-Barr virus.

Six renal transplant recipients with abnormal lymphoproliferative disorders were studied in an attempt to define their clinical features and the role of Epstein-Barr virus (EBV) in their pathogenesis. Patients were either teenage (three) or in the sixth decade (three). The younger patients presented an average of 3 months after transplantation with fever, sore throat, and lymphadenopathy; had been markedly immunosuppressed; frequently had preceding or concomitant cytomegalovirus infections; and two of three had a rapidly fatal course. The older patients presented an average of 5 years after transplantation while on maintenance immunosuppressive drugs; in two of three cases with an oropharyngeal tumor; and had a more indolent, but frequently fatal, clinical course. The most frequent sites of biopsy-proven involvement in these patients were lymph nodes (three), the oropharynx (three), liver (three), bone marrow (three), transplanted kidney (three), colon (two), and central nervous system (two). EBV-specific antibody titers including anti-viral capsid antigen IgG, anti-viral capsid antigen IgM, anti-early antigen, and anti-Epstein-Barr nuclear antigen were serially measured in all patients. Four patients demonstrated serological evidence of a primary (one) or reactivation (three) EBV infection. No patient had significant changes in anti-early antigen or anti-Epstein-Barr nuclear antigen titers. All three patients tested for oropharyngeal shedding of EBV were positive. A touch imprint of one tumor was stained for the presence of Epstein-Barr nuclear antigen, and a majority of cells were positive. EBV complementary RNA/DNA filter hybridization and/or viral DNA/DNA reassociation analysis performed on tumor biopsy specimens in five patients demonstrated multiple EBV genome equivalents per cell in all eight specimens tested. Clinical, pathological, serological, and molecular hybridization studies provide substantial evidence that EBV was the cause of these lymphoproliferative disorders occurring after renal transplantation. Impaired host defenses allow the EBV-transformed B-lymphocytes to escape normal control mechanisms. This impairment is invariable and influenced by many factors resulting in the observed spectrum of disease. Cytogenetic changes, however, may also be important.

Adolescent↗

[Effect of soedomycin (M3) on the phagocytosis in the mouse (author's transl)].

Effect of M3, an anticancer agent, on the phagocytic activity of the mouse reticuloendothelial system was studied by the carbon clearance method. Lysosomal enzyme activities of peritoneal exudate cells solution (PECs) and peritoneal macrophage (Mp), and morphological changes of Mp were also examined. The K index (phagocytic index) was significantly increased 24 hr after the administration of M3 (250,300 mg/kg, i.p. X 3) as well as that of zymosan (Z: 50 mg/kg, i.p. X 3). The time course on phagocytic activity of Me (300 mg/kg) was also investigated. The index was increased 2, 4, and 96 hr after i.p. administration, but on i.v. administration the index was decreased at 2 and 4 hr, although increased at 72 hr. Microscopically, carbon particles were internalized by Mp of marginal zones between white and red pulp in the spleen, and in the liver, mainly by Kupffer cells. Lysosomal enzyme activities (acid phosphatase and beta-glucuronidase) and cell numbers of PECs were increased as follows: Z greater than M3 greater than Na2HPO4. These enzyme activities in Mp were also increased significantly 72 and 96 hr after i.p. administration. Observing of morphology by Giemsa staining, saline and Na2HPO4 groups showed round monocytes, but in the M3 and Z groups there were enlarged cells with many projections. These results suggest that M3 promotes the phagocytic activity on the reticuloendothelial system in mice and has a stimulatory effect on Mp because of the increase in the lysosomal enzyme activities and morphological changes in the cells.

Acid Phosphatase↗

Chronic bullous disease with coexistent circulating IgG and IgA anti-basement membrane zone antibodies.

Coexistent circulating IgG and IgA anti-basement membrane zone (BMZ) antibodies were demonstrated in a patient with chronic bullous disease. Direct immunofluorescence microscopy showed IgG, IgA, and C3 deposits in a linear pattern at the BMZ in the patient's uninvolved skin. Ultrastructurally, the bulla was formed beneath the basal lamina as in dermatitis herpetiformis. This investigation might provide evidence for the immunologic overlap of bullous pemphigoid and dermatitis herpetiformis.

Antibodies↗