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Biomedical subjects

K Ohshima

Publications and source records attributed to K Ohshima.

At least 145 records · Page 8Linked to original sources
PubMed1998

Expression of four CEA family antigens (CEA, NCA, BGP and CGM2) in normal and cancerous gastric epithelial cells: up-regulation of BGP and CGM2 in carcinomas.

Four human carcinoembryonic antigen (CEA) family members, CEA (CD66e), non-specific cross-reacting antigen (NCA, CD66c), biliary glycoprotein (BGP, CD66a) and CEA gene-family member 2 (CGM2), are expressed in normal mucosal epithelia of the colon. Expression of BGP and CGM2 has recently been demonstrated to be down-regulated in colorectal adenocarcinomas. We have now investigated the expression of the 4 CEA family antigens in gastric adenocarcinoma and carcinoma cell lines in comparison with adjacent normal gastric mucosa. The transcripts of the CEA, NCA and BGP genes evaluated by reverse transcription-polymerase chain reaction were detectable at various levels in all the gastric adenocarcinoma cell lines tested, while CGM2 mRNA was detectable in the cell lines of poorly differentiated but not of well-differentiated carcinomas. The levels of CEA mRNA in normal gastric mucosa were variable but mostly increased in adenocarcinomas. The sparse expression of NCA observed in the normal tissues was markedly up-regulated in the carcinomas. In contrast to previous findings on normal and cancerous colonic tissues, the transcripts of CGM2 were totally undetectable and those of BGP were recognized only marginally, if at all, in normal gastric mucosa, while both messages were detected at significant levels in most of the gastric adenocarcinomas. This was confirmed by in situ hybridization. Our findings indicate that expression of the CEA family antigens, particularly that of BGP and CGM2, is differently regulated in epithelial cells of the colon and the stomach.

Adenocarcinoma↗
PubMed1998

Integrated and episomal forms of Epstein-Barr virus (EBV) in EBV associated disease.

Epstein-Barr virus (EBV) is known to be linear in viral particles but EBV circularizes into an episomal form after infection. Recently, the presence of integrated EBV DNA has been reported. We investigated EBV integration into the human genome in EBV-associated disease using Southern blotting. One hundred four cases in which the presence of EBV was confirmed by Southern blotting with EBV-W probes were thus analyzed with left- and right-hand end probes of linear EBV. Integrated EBV was demonstrated in 11 of 104 cases; five of 14 cases with B cell lymphoma (36%), one of 12 cases with nasopharyngeal carcinomas (8%), four of 31 cases with natural killer (NK) leukemia/lymphoma (13%) and one of 11 cases with chronic EBV infection (9%). However, none of the 24 T cell lymphoma, seven Hodgkin's disease, or five acute EBV infection cases showed integrated EBV. In addition, seven of the 11 cases with EBV integration (five B cell lymphoma and two NK leukemia/lymphoma) showed only an integration form, however, the other four (two NK leukemia/lymphoma, one nasopharyngeal carcinoma and one chronic EBV infection) showed both integrated and episomal forms. The integrated form was frequently found in B cell lymphoma and especially in high grade B cell lymphoma. Fluorescence in situ hybridization (FISH) was performed in two cases (NK and B cell lymphoma), which represented integrated EBV in Southern blotting and the integration form was confirmed in both. However, it is still uncertain as to whether or not the EBV integration site is directly associated with chromosomal abnormality.

Blotting, Southern↗
PubMed1998

Expression and cellular localization of low-density lipoprotein receptor-related protein/alpha 2-macroglobulin receptor in human glioblastoma in vivo.

Low-density lipoprotein receptor-related protein/alpha 2-macroglobulin receptor (LRP) has been proposed to mediate the cellular uptake and clearance of inactivated protease-inhibitor complexes in regulating proteinase activity at the cell surface, which is necessary for cellular migration and invasive processes. In this study, we investigated the presence of both LRP and urokinase-type plasminogen activator receptor (uPAR) in glioblastoma by reverse transcriptase-polymerase chain reaction (RT-PCR), and the cellular localization of LRP in glioblastoma tissues by immunohistochemical analysis. LRP mRNA was frequently expressed in glioblastomas and anaplastic astrocytomas compared with low-grade astrocytomas by RT-PCR analysis, and was well correlated with uPAR expression. The immunohistochemistry of LRP on sequential frozen sections showed that neoplastic glial cells and endothelial cells of glioblastomas exhibited intense LRP immunoreactivity, whereas LRP was almost undetectable in low-grade astrocytomas or in normal glial cells and endothelial cells of normal brain tissue. Glioblastomas from 11 patients in which the expression of LRP mRNA was observed by PCR displayed strong to moderate LRP immunoreactivity, with predominantly diffuse cytoplasmic and cell-surface localization. In normal brain tissues, LRP immunoreactivity was identified in the pyramidal neurons of the cerebral cortex. These results indicate that LRP is present both in the cellular cytoplasm and on the cell surface of glioblastomas with an increased expression of uPAR. Altered LRP expression might contribute to the stimulation of cell-surface proteolytic activity that in turn facilitates the invasiveness of glioblastoma in vivo.

Brain↗
PubMed1998

Apoptosis of cytotoxic T-cells in histiocytic necrotizing lymphadenitis.

Cell death is necrotic or apoptotic. In histiocytic necrotizing lymphadenitis (HNL), apoptosis is the main form of cell death, resulting in the creation of nuclear debris that is one of the characteristic features of HNL. To investigate the cell type of apoptotic cells, 12 cases of HNL were analyzed using the immunohistochemical staining for TIA-1, a cytotoxic granule of either cytotoxic T or NK cells. One quarter to over half of all apoptotic cells were positive for TIA-1, and some of the nuclear debris was also positive. The necrotic lesions of HNL were found to consist of nuclear debris, apoptotic cells, histiocytes and lymphocytes. The lymphocytes were mainly CD8-positive T-cells or CD4-positive cells, while B- and NK cells were only rarely observed. The number of TIA-1-positive lymphocytes was more closely related to the number of CD8-positive cells than to the number of CD4 cells. In double staining, the TIA-1 positive lymphocytes were mainly CD8 positive, but rarely CD4 positive. In HNL, then, CD8-positive cytotoxic T-cells are likely to undergo apoptosis.

Adolescent↗
PubMed1998

Successful graft replacement of the descending aorta after an extended reconstruction of the ascending and transverse aorta in a patient with Marfan's syndrome.

A 27-year-old man with Marfan's syndrome underwent a total aortic graft replacement in three separate stages. Initially the abdominal aorta was replaced, followed by the ascending aorta and aortic arch, and finally the residual portion. The extensive reconstruction of both the ascending and transverse aorta at the second operation, even though no dissection was present in the aortic arch, reduced the risk of the subsequent operation since the same surgical approach did not have to be used.

Adult↗
PubMed1998

Establishment of a novel B cell clonality analysis using single-strand conformation polymorphism of immunoglobulin light chain messenger signals.

The remarkable diversity of the complementarity determining region (CDR) 3 of the immunoglobulin (Ig) heavy (H) chain gene rearrangements has been exploited to identify the clonal populations of B cells in B cell malignancies. However, when B cell malignancies of different categories were examined, the overall detection rate was found to be approximately 70%. The development of a simple clonality analysis using Ig light (L) chain CDR3 diversity has been hampered due to the sparseness of knowledge regarding the sequence of Vkappa and Vlambda gene segments and the restriction of L chain CDR3 length. Based on the recently reported Vkappa and Vlambda gene sequences, we designed Vkappa and Vlambda framework 3 consensus primers. We combined the reverse transcriptase polymerase chain reaction (RT-PCR) of IgL chain transcripts with a single-strand conformation polymorphism (SSCP) analysis and then analyzed samples from patients with B cell malignancies. Clonal B cell populations were detected as discrete bands, and identical clones showed a similar mobility in a RT-PCR SSCP analysis. This method was thus found to be a useful supplement to the previously described approach of VH gene amplification for detecting clonal B cell populations. By using SSCP, we were able to determine the clonal identities of B cell expansion in different samples.

Arthritis, Rheumatoid↗
PubMed1998

Intrathecal administration of p-hydroxymercuribenzoate or phosphoramidon/bestatin-combined induces antinociceptive effects through different opioid mechanisms.

The antinociceptive effect of intrathecally (i.t.) administered protease inhibitors was tested against capsaicin (800 ng) injected into the dorsal surface of a hindpaw. Both p-hydroxymercuribenzoate (2-8 nmol), a cysteine protease inhibitor, and phosphoramidon (1-4 nmol), an endopeptidase 24.11 inhibitor in the presence of bestatin (0.25 nmol) an aminopeptidase inhibitor, administered i.t. 60 min prior to the injection of capsaicin produced a dose-dependent reduction of the capsaicin-induced paw licking and biting response. p-Hydroxymercuribenzoate (4 nmol)-induced antinociception was significantly antagonized by nor-binaltorphimine, a selective kappa-opioid receptor antagonist, but not by naltrindole, a selective delta-opioid receptor antagonist. On the other hand, phosphoramidon (4 nmol) /bestatin-induced antinociception was significantly antagonized by naltrindole, but not by nor-binaltorphimine. The results indicate that the antinociceptive effect of p-hydroxymercuribenzoate may be due to the inhibition of a cysteine protease degrading endogenous dynorphins whereas phosphoramidon in the presence of bestatin blocks the degradation of enkephalins.

Animals↗
PubMed1998

Antisense homology box-derived peptides represent a new class of endothelin receptor inhibitors.

Several peptides encoded by the sense and corresponding antisense DNA have been found to recognize and bind to each other. We developed software to search for sense-antisense regions within proteins taking into account the degeneracy of the genetic code, i.e., one amino acid can have several "antisense" counterparts. Using this approach, we searched endothelin receptor type A for intramolecular regions related in sense-antisense fashion. After locating these regions (termed "antisense homology boxes"), several corresponding peptides were synthesized. The four new ET(A) receptor fragment peptides ETR-P1 ("CALSVDRYRAVASW"), ETR-P3 ("QGIGPLITAIEI"), ETR-P4 ("IADNAERYSANLSSHV") and ETR-P6 ("LNRRNGSLRIALSEHLKNRREVA") reported here can inhibit ET-1 activity.

3T3 Cells↗
PubMed1998

Nodal T-cell lymphoma in an HTLV-I-endemic area: proviral HTLV-I DNA, histological classification and clinical evaluation.

Adult T-cell leukaemia/lymphoma (ATLL) is a human malignancy associated with human T-cell leukaemia virus type I (HTLV-I). The histology usually indicates a pleomorphic type, but is not consistent. To clarify the relationship between the histological classification and prognosis in ATLL, and to confirm the significance of clonal HTLV-I integration, we reclassified 572 cases with nodal T-cell lymphoma in which the T-cell phenotype and/or genotype was confirmed. In all cases the clonal integration of HTLV-I proviral DNA in the lymph nodes was examined by Southern blot analysis. In addition, anti-ATL antigen (ATLA) determination in the serum or PCR analysis of HTLV-I pX amplification in lymph nodes was also performed. 66/313 (21%) cases with ATLA had no evidence of clonal HTLV-I integration. 572 cases were classified into three groups: (A) cases with clonal integration (247 cases), (B) cases with ATLA without clonal integration of HTLV-I proviral DNA (66 cases), (C) cases without ATLA (259 cases). Histologically, groups B and C frequently demonstrated large cell type and angioimmunoblastic lymphadenopathy with dysproteinaemia (AILD) type; however, group A tended to show a pleomorphic type. Clinically, group A showed a poorer prognosis than groups B and C. In conclusion, group A cases were defined as ATLL (HTLV-I-associated T-cell lymphoma), whereas group B was classified as T-cell lymphoma, which had coincidently occurred in HTLV-I infected carriers. The simplified classification of REAL indicated clinical outcome: the prognosis of ATLL was poor, the unspecified type was intermediate, whereas the other types of lymphoblastic, AILD and anaplastic large cell type were all relatively favourable.

Blotting, Southern↗
PubMed1998

Elevated serum soluble Fas ligand in natural killer cell proliferative disorders.

We evaluated the serum level of soluble Fas ligand (sFasL) in patients with natural killer lymphocyte proliferative disorders (NK- LPD). The serum sFasL level was elevated in neoplastic groups of aggressive NK leukaemia, indolent NK leukaemia and NK lymphoma, all of which contained clonal EBV-DNA. In NK leukaemia the serum sFasL level was significantly higher than that found in others. However, it was not elevated in the patients with reactive NK-LPD and in one patient with NK leukaemia in remission. These findings indicate that the serum sFasL level is a useful indicator in evaluating disease activity.

Adolescent↗
PubMed1998

Perforin and Fas pathways of cytotoxic T-cells in histiocytic necrotizing lymphadenitis.

AIMS: Cell death can be divided into necrosis and apoptosis. In histiocytic necrotizing lymphadenitis (HNL), apoptosis is the main form of cell death. Two molecular mechanisms of T-cell-mediated cytotoxicity, one perforin-based and the other Fas-based, have been demonstrated, and both systems induce apoptosis of the target cells. This study was designed to investigate the Fas and perforin pathways in HNL. METHODS AND RESULTS: Twelve cases of HNL were analysed using immunohistochemical staining. The Fas and/or FasL-positive cells, including lymphocytes and histiocytes, were frequently encountered in the necrotizing lesions, however, they were rare in the nonpathological regions. The perforin and/or granzyme-positive cells were also confined in the necrotizing lesions. In double staining, CD8-positive lymphocytes occasionally expressed Fas and/or FasL, and histiocytes also expressed FasL and/or Fas. However, CD4-positive lymphocytes rarely expressed FasL and/or Fas. In a flow cytometric analysis, most of the cytotoxic T-cells, which were recognized by cytolytic granules of TIA-1 and considered to be CD8-positive lymphocytes, expressed FasL and Fas. The perforin-positive lymphocytes also expressed FasL and Fas. CONCLUSION: In our previous study, the apoptotic cells were T-cells, especially CD8-positive cells rather than CD4-positive cells. Based on these findings, in Fas and perforin pathways, the CD8-positive cells were considered to be effector and target cells, while histiocytes could possibly be enhancers. As a result, both pathways seemed to induce an abundance of apoptosis and thus induce necrotizing lesions.

Adolescent↗
PubMed1998

Molecular characterization of the PEND protein, a novel bZIP protein present in the envelope membrane that is the site of nucleoid replication in developing plastids.

Plastid nucleoids are known to bind to the envelope membrane in developing chloroplasts. Here, plastid DNA is extensively replicated. We previously detected a DNA binding protein in the inner envelope membranes of developing plastids in pea and named it PEND (for plastid envelope DNA binding) protein. In this study, we report on the structure and molecular characterization of a cDNA for the PEND protein. As a result of screening cDNA libraries in lambdagt11 with one of the target sequences of the PEND protein as a probe, we obtained a clone (PD2) for a novel DNA binding protein consisting of 633 amino acid residues. Analysis of the N-terminal sequence of the purified PEND protein indicated that the transit peptide is just 16 residues long. The PEND protein was detected specifically in the plastid envelope membrane of young unopened leaf buds by immunoblot analysis. The PEND protein consists of a basic region plus zipper region, an unprecedented sextuple repeat region, and a putative membrane-spanning region. The basic region with a zipper region seems to have diverged from that of other plant transcription factors. In addition, the PEND protein could be a distant homolog of the trans-Golgi network integral membrane proteins. The PEND protein is therefore a novel type of DNA binding protein that binds to the membrane as an intrinsic membrane protein.

Amino Acid Sequence↗
PubMed1998

Clinicopathological study of severe chronic active Epstein-Barr virus infection that developed in association with lymphoproliferative disorder and/or hemophagocytic syndrome.

Chronic active Epstein-Barr virus (CAEBV) infection has been previously reported to be sometimes associated with an aggressive clinical course. However, the role of EBV in the CAEBV is not well clarified. A retrospective study was performed on nine adult and five child patients (eight males and six females). Histologically, at first admission, the presence of neoplastic lesions could not be confirmed. The lymph nodes in half of all cases revealed paracortical hyperplasia with transformed lymphocytes (hyperplastic type). Half of the cases showed non-suppurative necrosis and an increased number of histiocytes with phagocytosis (histiocytic type). Activated histiocytes with lymphokine positivity were frequently detected in the histiocytic type. In the phenotypical study, 10 of the examined 11 cases showed increased numbers of natural killer (NK) cells and/or CD8-positive T lymphocytes. In situ hybridization (ISH) showed EBV-infected lymphoid cells, but the number of EBV-infected cells varied. Double-labeling immunochemistry/ISH demonstrated EBV-infected T cells, including NK cells, but not B cells. In addition, three cases showed a monoclonal dissemination of EBV terminal repetitive sequence (TR), and two cases showed oligoclonal dissemination. From those findings, monoclonal, oligoclonal and polyclonal populations of EBV-infected T or NK cells were considered to be present in CAEBV states. During the clinical course, 12 of the 14 cases died within 5 years. Six cases died from EBV-associated hematopoietic tumors (histiocytic tumor, T cell lymphoma, B cell lymphoma, plasmacytoma, and NK cell leukemia); one from non-EBV-associated acute myelogenous leukemia, and five due to hemophagocytic syndrome. The examined EBV-associated hematopoietic tumors showed monoclonal EBV terminal repetitive sequences. There is a possibility that the monoclonal dissemination of EBV-infected cells develops from oligoclonal or polyclonal EBV-infected cells. And active histiocytes with lymphokine positivity were frequently detected in the cases with histologically histiocytic type. These findings seem to be related with the causes of death due to hemophagocytic syndrome.

Adolescent↗
PubMed1998

Purification and Characterization of Exo-beta-d-Glucosaminidase from a Cellulolytic Fungus, Trichoderma reesei PC-3-7.

Chitosan-degrading activities induced by glucosamine (GlcN) or N-acetylglucosamine (GlcNAc) were found in a culture filtrate of Trichoderma reesei PC-3-7. One of the chitosan-degrading enzymes was purified to homogeneity by precipitation with ammonium sulfate followed by anion-exchange and hydrophobic-interaction chromatographies. The enzyme was monomeric, and its molecular mass was 93 kDa. The optimum pH and temperature of the enzyme were 4.0 and 50 degrees C, respectively. The activity was stable in the pH range 6.0 to 9.0 and at a temperature below 50 degrees C. Reaction product analysis from the viscosimetric assay and thin-layer chromatography and H nuclear magnetic resonance spectroscopy clearly indicated that the enzyme was an exo-type chitosanase, exo-beta-d-glucosaminidase, that releases GlcN from the nonreducing end of the chitosan chain. H nuclear magnetic resonance spectroscopy also showed that the exo-beta-d-glucosaminidase produced a beta-form of GlcN, demonstrating that the enzyme is a retaining glycanase. Time-dependent liberation of the reducing sugar from partially acetylated chitosan with exo-beta-d-glucosaminidase and the partially purified exo-beta-d-N-acetylglucosaminidase from T. reesei PC-3-7 suggested that the exo-beta-d-glucosaminidase cleaves the glycosidic link of either GlcN-beta(1-->4)-GlcN or GlcN-beta(1-->4)-GlcNAc.

Journal Article↗