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Biomedical subjects

A Oyama

Publications and source records attributed to A Oyama.

At least 19 recordsLinked to original sources
PubMed1994

Unusual anticodon loop structure found in E.coli lysine tRNA.

Although both tRNA(Lys) and tRNA(Glu) of E. coli possess similar anticodon loop sequences, with the same hypermodified nucleoside 5-methylaminomethyl-2-thiouridine (mnm5s2U) at the first position of their anticodons, the anticodon loop structures of these two tRNAs containing the modified nucleoside appear to be quite different as judged from the following observations. (1) The CD band derived from the mnm5s2U residue is negative for tRNA(Glu), but positive for tRNA(Lys). (2) The mnm5s2U monomer itself and the mnm5s2U-containing anticodon loop fragment of tRNA(Lys) show the same negative CD bands as that of tRNA(Glu). (3) The positive CD band of tRNA(Lys) changes to negative when the temperature is raised. (4) The reactivity of the mnm5s2U residue toward H2O2 is much lower for tRNA(Lys) than for tRNA(Glu). These features suggest that tRNA(Lys) has an unusual anticodon loop structure, in which the mnm5s2U residue takes a different conformation from that of tRNA(Glu); whereas the mnm5s2U base of tRNA(Glu) has no direct bonding with other bases and is accessible to a solvent, that of tRNA(Lys) exists as if in some way buried in its anticodon loop. The limited hydrolysis of both tRNAs by various RNases suggests that some differences exist in the higher order structures of tRNA(Lys) and tRNA(Glu). The influence of the unusual anticodon loop structure observed for tRNA(Lys) on its function in the translational process is also discussed.

Anticodon↗
PubMed1993

Clinicopathologic study of 212 cases of peripheral T-cell lymphoma among the Japanese.

BACKGROUND: Postthymic/peripheral T-cell malignancy shows significant histopathologic and clinical diversity, even in its prognosis, and the correlations remain to be debated. METHODS: The clinicopathologic features of 212 Japanese patients with these neoplasms were investigated. RESULTS: There were 131 male and 81 female patients, whose ages ranged from 2 to 90 years (mean, 51.7 years). Lymphadenopathy was the most frequent clinical presentation, and the patients also had frequent skin lesions, hyperimmunoglobulinemia, hypercalcemia, and a rapid clinical course. Furthermore, the differences in the histologic features of each subcategory reflected the clinical pictures. The immunophenotypic analysis was indispensable in establishing a correct diagnosis, and the high-grade tumors often showed loss of pan-T antigens. CONCLUSIONS: The histopathologic classification proposed by Suchi et al., which has been incorporated into the updated Kiel classification, showed a good prognostic correlation.

Adolescent↗
PubMed1993

Aggressive rectal lymphoma of large granular lymphocytes with the histologic feature of an angiocentric growth pattern.

The authors report an unusual large cell lymphoma of the rectum composed of large granular lymphocytes (LGL) with histologic characteristics of an angiocentric growth pattern. Immunophenotyping showed that most of the tumor cells were CD3-, CD4-, CD8+, CD16+, CD56+, and CD57-. Fine structural analysis of the tumor cells found substantial numbers of electron-dense granules. Genotypic investigation showed a germline configuration of the T-cell receptor beta and gamma chain genes and the immunoglobulin heavy chain gene. The clinical course was aggressive, with rapid dissemination to the lungs, liver, and subcutis. The lesion was resistant to chemotherapy. There was, however, no evidence for peripheral blood or bone marrow involvement. This case report demonstrates the need for continued inquiry into the possible association of LGL with angiocentric lymphoproliferative lesions and gut-associated T-lymphocyte lesions.

Adult↗
PubMed1993

Differences in clinicopathological characteristics and major prognostic factors between B-lymphoma and peripheral T-lymphoma excluding adult T-cell leukemia/lymphoma.

A total of 541 consecutive patients treated between 1975 and 1985, 449 with B-lymphoma and 92 with peripheral T-lymphoma, excluding adult T-cell leukemia/lymphoma (ATL), termed peripheral non-ATL T-lymphoma, were analysed. Clinicopathological features that were predominantly associated with B-lymphoma were low and intermediate grades (defined by the Working Formulation), diffuse large cell type, stage II disease, bulky disease, favourable extranodal sites that are defined as a group of primary tumors such as the eye, Waldeyer's ring, thyroid, and stomach, while other features predominantly associated with peripheral non-ATL T-lymphoma were high grade pathology, diffuse mixed-cell and immunoblastic type, systemic "B" symptoms, poor performance status (PS), generalized lymphadenopathy, involvement of organs such as liver, skin, and nose, leucocytosis, and a high levels of serum alkaline phosphatase. The survival curve for B-lymphoma was better (P < 0.01) than that for peripheral non-ATL T-lymphoma. Multivariate analysis revealed that the major prognostic factors were pathology, stage, and primary site for B-lymphoma, while stage, PS, and total protein levels were important for peripheral non-ATL T-lymphoma. These results indicate that B- and peripheral non-ATL T-lymphomas appear to have different biological characteristics.

Adult↗
PubMed1993

[Investigation of meropenem levels in the human bone marrow blood, bone, joint fluid and joint tissues].

A solution of 0.5 g of meropenem (MEPM) in 100 ml of saline was administered to adult patients before the orthopaedic surgery via intravenous drip infusion for 30 minutes. Eleven samples of bone marrow blood, 13 bone, 8 joint fluid and 8 joint tissues obtained from 15 clinical cases were analyzed for MEPM levels. At the same time, blood samples were taken from peripheral veins and serum served as control was analyzed. The concentration of MEPM in the marrow blood at 30 minutes after administration of MEPM reached 15.4 micrograms/ml, which was above 50% of the maximum concentration in serum. Ratios of concentration in bone marrow to that in serum were between 93% and 105% at that time. MEPM levels were 5.74-0.40 micrograms/g in bones, 20.3-4.55 micrograms/ml in joint fluid and 18.2-4.05 micrograms/g in joint tissues at 30 to 75 minutes after administration. In joint fluid and joint tissues, the concentration above 50% of maximum level in serum were maintained for more than an hour. MEPM is thought to be useful for the treatment of bone and joint infections and also prophylaxis of infections in cases of major surgery of skeletal tissue in the field of orthopaedic surgery.

Adult↗
PubMed1992

Malignant lymphoma of mucosa-associated lymphoid tissue arising in the thymus of a patient with Sjögren's syndrome. A morphologic, phenotypic, and genotypic study.

A 59-year-old woman with Sjögren's syndrome had an anterior mediastinal tumor. The tumor had epithelium-lined thymic cysts. Histologically, centrocyte-like (CCL) cells were present as clusters intermingling with small lymphocytes and plasma cells, invaded the epithelium, and formed characteristic lymphoepithelial lesions; the tumor was identified as malignant lymphoma arising in mucosa-associated lymphoid tissue (MALT). Within the tumor, trapped Hassall's corpuscles were recognized. Immunohistochemical staining demonstrated monotypic cytoplasmic kappa light chains in a small portion of the CCL cells. Furthermore, Southern blot hybridization studies showed rearrangements of immunoglobulin heavy chain, immunoglobulin kappa light chain, and T-cell receptor beta genes. The findings are consistent with thymic low-grade B-cell MALT lymphoma.

Cytoplasm↗
PubMed1992

Phenotypic and genotypic lineage switch of a lymphoma with shared chromosome translocation and T-cell receptor gamma gene rearrangement.

A case of non-Hodgkin's lymphoma showed a phenotypic and genotypic cell lineage switch twice during nine years of his clinical history; first, T-cell type, pleomorphic small cell lymphoma developed, followed by B-cell type, diffuse centroblastic/centrocytic lymphoma, and finally T-zone lymphoma without follicles again developed, from which AST-1 cultured cell line was established. Karyotype analysis demonstrated a shared abnormal chromosome, der(1)t(1;?)(p36;?), among the first relapsed B-cell tumor, the second relapsed T-cell tumor and AST-1 cell line. Furthermore, T-cell receptor (TCR) gamma gene rearrangement bands of the same size were observed in the first relapsed B-cell tumor and the second relapsed T-cell tumor as well as AST-1 cell line. These results suggested that both relapsed tumors of different cell lineages are derived from a common malignant clone, presumably a committed lymphoid stem cell. A unique translocation, t(2;14)(q37;q11.2), which may involve TCR delta/alpha gene complex, was observed in the second relapsed tumor and AST-1 cells. To attempt to isolate the breakpoint of this translocation, the configuration of TCR delta/alpha gene complex was studied. The result showed that two rearrangements of TCR alpha gene detected with J alpha probes were the products of the normal TCR rearrangement process, and were not involved in the translocation at this region. This patient, together with the AST-1 cell line, provided us a unique opportunity to study the development and clonal evolution of malignant lymphoma.

Amino Acid Sequence↗
PubMed1992

Peripheral T-cell lymphoma of AILD (angioimmunoblastic lymphadenopathy with dysproteinemia) type involving gastrointestinal tract. A morphologic, phenotypic and genotypic study.

A case of angioimmunoblastic lymphadenopathy with dysproteinemia (AILD) which showed widespread involvement of the gastrointestinal tract is reported. A lymph node biopsy specimen showed the characteristic histological features of AILD. During the progression of the illness, lymphomatous lesions developed in the gastrointestinal tract, complicated by cytomegalovirus infection. A double immunoenzymatic study using a combination of Ki-67 antibody and antibodies against surface antigens demonstrated that CD3+, CD4+, and/or T-cell receptor (TCR) beta+ cells were predominant (67-68%) among the population of proliferating Ki-67% cells, rather than CD8+ or CD22+ cells. Clonal rearrangement of the TCR beta chain gene was also detected. These findings provide further evidence for the neoplastic nature of lesions of this type, and the diagnosis of peripheral T-cell lymphoma.

Antigens, CD↗
PubMed1992

[A case of renal cyst associated with renal cell carcinoma--characteristics of intracystic fluid associated with renal cell carcinoma from Japanese reports].

The patient was a 56-year-old male. Renal cyst and intracystic mass were incidentally found in the right kidney by ultrasound sonography. Intracystic mass was enhanced. At operation, intracystic fluid was clear and yellow, and its cytology was negative. However, rapid histological examination of the intracystic mass showed malignancy. Accordingly, nephrectomy was performed. We then reviewed the characteristics of the intracystic fluid in renal cell carcinoma reported in Japan and found that 70% was bloody intracystic fluid and 30% showed positive cytology. These findings suggested that we should to be more careful when diagnosing renal cyst associated with renal cell carcinoma only by the examination of the intracystic fluid.

Body Fluids↗
PubMed1991

Clinicopathologic study of large cell anaplastic lymphoma (Ki-1-positive large cell lymphoma) among the Japanese.

The clinical, prognostic, phenotypic, and genotypic findings of 30 patients with large cell anaplastic lymphoma (Ki-1-positive large cell lymphoma) were analyzed. There were 13 male and 17 female patients (male-female ratio, 0.8) whose ages ranged from 3 to 81 years of age (mean, 28 years of age; 67% of the patients younger than 30 years of age). The 5-year survival rate was 52%; this was better than that of other types of high-grade peripheral T-cell lymphoma. Histologic examination showed distinctive morphologic features such as tumor cell pleomorphism, sinus infiltration, fibrosis, partial lymph node involvement, sparing of B-cell regions, and occasional plasma cell infiltrates. Eighty percent of the cases were of T-cell phenotype, and others expressed neither B-cell nor T-cell markers. The tumors were frequently positive for a histocompatibility antigen (HLA-DR), CD25 (the interleukin-2 receptor), and epithelial membrane antigen. Rearrangements of the T-cell receptor beta gene were observed in nine of 13 cases (69%). These findings indicated that many of the tumors had the phenotype and genotype of activated T-cells. This study also showed that large cell anaplastic lymphoma has a survival figure intermediate between Hodgkin's disease and low-grade peripheral T-cell lymphoma.

Adolescent↗
PubMed1991

bcl-2 translocation in Japanese B cell lymphoma: novel bcl-2 translocation with immunoglobulin heavy chain diversity segment.

Breakpoints of a lymphoma case with bcl-2 gene rearrangement that did not show comigration of immunoglobulin (Ig) heavy chain joining (JH) fragment were cloned. Sequence analysis revealed that the translocation broke the 3' side of the Ig heavy chain diversity (DH) segment at the heptamer recombination signal and each end was ligated to the bcl-2 locus. Since Southern blot demonstrated that both alleles of JH were rearranged, this translocation was suggested to have occurred at the step of VH-DH, or DH-DHJH recombination, one step later than that of DH-JH recombination where the common pattern of bcl-2 rearrangement generally occurs. Cases that showed comigration with JH fragment were also studied by polymerase chain reaction with 5' bcl-2 oligomer and 3' JH consensus anti-sense oligomer since it has been demonstrated that bcl-2 translocation at the major breakpoint clustering region (mbr) in American cases clusters within an about 150 bp region in the mbr. The results demonstrated that four out of five cases studied were amplified, indicating that the same clustering mechanism exists for Japanese cases. The present study, together with our previous report on Ig kappa-bcl-2, indicated that bcl-2 translocation in Japanese B cell lymphomas might occur at a later stage of B cell development, as compared with that in American cases. Less involvement of bcl-2 in Japanese B cell lymphoma may also be in part explainable by low susceptibility to bcl-2 rearrangement at the step of DH-JH recombination.

Base Sequence↗
PubMed1990

[A double-blind, cross-over clinical trial of recombinant human G-CSF on neutropenia induced by chemotherapy for non-Hodgkin's lymphoma].

A double-blind, placebo-controlled, cross-over clinical trial of recombinant human granulocyte colony-stimulating factor (rG-CSF), produced by Chinese hamster ovary cells, was conducted in 46 patients receiving intensive chemotherapy for non-Hodgkin's lymphoma. Each patient received 2 cycles of CHOP therapy. rG-CSF (2 micrograms/kg/day) or its placebo was given subcutaneously to each patient for 14 days from 2 days after initiation of the chemotherapy, in a cross-over fashion. rG-CSF significantly increased the absolute neutrophil counts (ANC) at nadir, and reduced the number of days with ANC less than 1,000/mm3 and also the number of days for recovery to ANC greater than or equal to 2,000/mm3. Bone marrow examination showed a significant increase in the number of myeloid cells after rG-CSF treatment. 12 infective episodes were observed during placebo cycles, while 6 infective episodes were observed during rG-CSF cycles. No serious side effects were observed. We concluded that rG-CSF was effective in neutropenia induced by intensive chemotherapy for non-Hodgkin's lymphoma.

Adult↗
PubMed1990

[Clinical effect of recombinant human G-CSF on neutropenia induced by chemotherapy for non-Hodgkin's lymphoma].

A clinical trial of recombinant human granulocyte colony-stimulating factor (rG-CSF), produced by Chinese hamster ovary cells, was conducted in 66 patients receiving intensive chemotherapy for non-Hodgkin's lymphoma. Each patient received 2 cycles of CHOP therapy, and one cycle of them was performed with rG-CSF treatment and another one without rG-CSF treatment, in a cross-over fashion. rG-CSF (0.4, 2, 5, 10 micrograms/kg/day) was given intravenously or subcutaneously to each patient for 14 days from 2 days after initiation of the chemotherapy. rG-CSF increased the absolute neutrophil counts (ANC) at nadir, and reduced the period of neutropenia with ANC less than 1,000/mm3 and also the period for restoration to ANC greater than or equal to 2,000/mm3 after initiation of chemotherapy. These effects were remarkable at doses of more than 5 micrograms/kg/day intravenously and 2 micrograms/kg/day subcutaneously. Fourteen infective episodes were observed during the cycles of chemotherapy without rG-CSF treatment, while 7 infective episodes were observed during the cycles with rG-CSF treatment. rG-CSF was well tolerated. These results demonstrated that rG-CSF was effective in neutropenia induced by cancer chemotherapy at a intravenous dose of 5 micrograms/kg/day and a subcutaneous does of 2 micrograms/kg/day.

Adult↗
PubMed1990

Changes in clinico-pathological features of Hodgkin's disease and follicular lymphoma in Nagoya, Japan, over a 21-year period (1965-85).

To study changes in the clinico-pathological features of malignant lymphomas in Japan, the histopathological and clinical features of 71 cases of Hodgkin's disease and 49 cases of nodal follicular lymphoma occurring in Nagoya were compared in three different periods (1965-71, 1972-78 and 1979-85). The proportional frequency of Hodgkin's disease among total lymphomas (10%) and that of follicular lymphoma among non-Hodgkin's nodal lymphomas (18%) did not vary over the study period. As to the histological patterns of Hodgkin's disease, the relative frequency of the nodular sclerosis (NS) type, which is relatively common in young women, increased, but that of other types decreased in the more recent periods. For follicular lymphoma, the relative frequency of the completely follicular type, which is more common in the United States than in Japan, increased. The five-year survival rate in patients with follicular lymphoma improved more recently even after adjusting for the effects of other prognostic factors. This recent increase in survival rates may be due partly to the recent improvement in cancer treatment, but is also related to the recent increase in patients with better prognostic features, i.e. the NS type of Hodgkin's disease. These variations over time suggest that the patterns of malignant lymphomas in Japan might be gradually changing, probably because of westernization, as seen in cancers of other organs.

Adolescent↗
PubMed1990

[Smoldering leukemia with pyoderma gangrenosum].

A 76-year-old male admitted to Surugadai Nihon University hospital complaining of general fatigue, slight fever and anorexia. The laboratory examination revealed anemia and an appearance of a few myeloblasts and 7% of monocytes in the peripheral blood. The nucleated cell count was 2 x 10(4)/microliters with 43% myeloblasts in the bone marrow aspirate. He was diagnosed as acute myelomonocytic leukemia. He did not receive any chemotherapy for leukemia because of his old age and smoldering disease. Pyoderma gangrenosum developed in the left submandibular and axillary regions about 6 months later. Three more month later, significant increase of myeloblast was recognized in the peripheral blood and the bone marrow. It has been reported that pyoderma gangrenosum precedes a remarkable increase of leukemic cells in the patients with acute leukemia in complete remission and with myelodysplastic syndrome. In our case, to, the same process was strongly suggested.

Aged↗
PubMed1990

[Characteristics of B-cell lymphoma in Japan].

Consecutive 431 patients with B-cell lymphoma seen in Aichi Cancer Center Hospital from 1964 to 1988 were analysed. Median age was 56 yr (range 8-86). There were 76 patients (17.6%) with follicular lymphoma and 355 with diffuse lymphoma. Among the 30 patients with follicular lymphoma, 10 (33%) were found to have a bcl-2 rearrangement. The incidence was lower than those reported in the United States. This might contribute to the lower incidence of follicular lymphoma cases in Japan. There were 168 patients (39.0%) with nodal lymphoma and 263 with extranodal lymphoma. Eight-four cases arose from the stomach, 84 from Waldeyer's ring, 21 small intestine and 13 thyroid. The distributions of extranodal B-cell lymphoma differed from those of T-cell lymphoma. Patients with gastric lymphomas in stage I were treated with resection alone. In the same manner, patients with Waldeyer's ring lymphoma in stage I were treated with radiotherapy alone. More than 90% of these patients were expected to survive without relapse. On the other hand, only 55% of patients with nodal lymphoma in stage I were expected to survive for more than 10 years. These findings suggest the site of localized lymphoma is an important determinant of outcome of clinical behavior.

Adolescent↗