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Biomedical subjects

K Ohshima

Publications and source records attributed to K Ohshima.

At least 253 records · Page 14Linked to original sources
PubMed1994

Angiocentric lymphoma with granulomatous panniculitis in the skin expressing natural killer cell and large granular T-cell phenotypes.

We investigated three patients suffering from angiocentric lymphoma with granulomatous panniculitis in the skin. All three patients presented with multiple purple subcutaneous nodules. Immunohistologically, the lymphoma cells in all three patients expressed CD2 (T-11), CD56 (neural cell adhesion molecule), and Mik-beta 1 (interleukin-2 beta receptor). CD3s (CD3, Leu-4)-positive lymphoma cells were found in two patients. A pore-forming protein (perforin) was detected in the lymphoma cells of all three patients. Perforin-possessing lymphoid cells were focally scattered in 2 of 15 patients with CD56-negative cutaneous lymphomas who served as controls. By the Southern blot method, one patient showed a rearranged T-cell receptor (TcR)beta gene in the biopsied specimen, and the other two patients had germ-line configurations of TcRs and immunoglobulin heavy chain genes. One patient had serum anti-human T-cell lymphotropic virus (HTLV)-I antibody, but showed no integration of its proviral DNA. Ultrastructurally, membrane-bound azurophilic granules were detected in the atypical lymphoid cells of all three patients. Angiocentric lymphoma with panniculitis in three patients showed the characteristics of natural killer and large granular T-cells. The histological features might be due to the characteristics of the neoplastic cells with azurophilic granules and perforin.

Aged↗
PubMed1994

Estimation of remnant liver function before hepatectomy by means of technetium-99m-diethylenetriamine-pentaacetic acid galactosyl human albumin.

To improve the results of hepatectomy in cirrhotic patients, the likely reserve function of the liver was evaluated before surgery. Asialoglycoprotein receptor (ASGP-R) is a hepatic cell surface receptor specific for galactose-terminated glycoproteins. Technetium-99m-diethylene triamine pentaacetic acid-galactosyl human serum albumin (99mTc-GSA) is a newly developed analog ligand to ASPG-R. The probable functional reserve of the remnant liver after hepatectomy was estimated preoperatively as the hepatic binding protein (HBP) concentration specific for ASGP-R on the hepatocellular membrane of the remnant liver. This estimate was based on the effective liver volume rate, obtained by the uptake of 99mTc-GSA. In all, 3 normal volunteers, 3 patients with chronic hepatitis (CH), 9 patients with liver cirrhosis (LC), 2 patients with hepatic cystadenoma, 3 patients with hepatocellular carcinoma (HCC) associated with CH, and 21 HCC patients with LC were studied. The mean value +/- SD obtained for HBP in normal volunteers (three cases) and in patients with mild (four cases), moderate (two cases), and severe liver damage (five cases) were 0.74 +/- 0.03 microM, 0.43 +/- 0.042 microM, 0.31 +/- 0.05 microM, and 0.20 +/- 0.05 microM, respectively. Most of the cases in which the preoperative HBP of the remnant liver was above 0.22 microM had a good postoperative course irrespective of the type of hepatectomy. On the other hand, in subjects with a remnant liver HBP of between 0.22 and 0.11 microM, postoperative severe liver dysfunction occurred in about 50% of cases. In all cases with a remnant liver HBP below 0.1 microM, the prognosis was very poor, indicating that hepatectomy should be avoided. The HBP concentration detected by the 99mTc-GSA study is a very sensitive indicator of changes in the hepatic functional reserve, and the HBP value for the functional reserve of the remnant liver is extremely useful for estimating the liver function before and after hepatectomy.

Adult↗
PubMed1994

Activities, localizations, and roles of serine proteases and their inhibitors in human brain tumor progression.

The plasminogen activation system consists of plasminogen activators and their inhibitors, serine proteases, and serpins. The proteases and inhibitors regulate a variety of processes in tissue morphogenesis, differentiation, cell migration, and cancer cell invasiveness and metastasis. One of the plasminogen activators, urokinase-type plasminogen activator (uPA), binds to a specific surface and provides a localized cell surface proteolytic activity required for the destruction of extracellular matrix, which is a vital step in tumor cell invasion. The proteolytic activity of uPA is modulated by its cell surface receptor, as well as by plasminogen activator inhibitor type-1 (PAI-1) and, to a lesser degree, by other inhibitors. The role of plasminogen activators and their inhibitors in cancer invasion can be demonstrated in the development and progression of malignant brain tumors. Our findings indicate that uPA and PAI-1 expression are dramatically upregulated in malignant brain tumors in parallel with the histological progression of the tumors. The results suggest that these molecules may contribute to tumor invasion in addition to their significant role in angiogenesis. An evaluation of the plasminogen activation system could add diagnostic and prognostic significance to the evaluation of individual patients.

Brain Neoplasms↗
PubMed1994

Nucleotide sequences and expression in Escherichia coli of the coat protein genes from two strains of melon necrotic spot virus.

The nucleotide sequences of coat protein (CP) genes of two Japanese strains of melon necrotic spot virus (MNSV-NH and MNSV-S) were determined. The size of the CP genes of both strains was 1170 nucleotides. Comparisons of the deduced amino acid sequences among MNSV strains showed more than 95% homology, and those among other carmoviruses showed 31-34% homology. cDNAs of MNSV CP genes were cloned into an Escherichia coli expression fusion vector and MNSV-NH and MNSV-S CPs were successfully produced. Furthermore, synthetic oligonucleotide primers were used for differentiating MNSV strains by reverse transcription-polymerase chain reaction method.

Amino Acid Sequence↗
PubMed1994

Clonality of benign lymphoid hyperplasia in orbit and conjunctiva.

In order to thoroughly characterize the clonal population of lymphoid hyperplasia of the orbit and conjunctiva, we investigated six cases which were histologically proven to be benign lymphoid hyperplasia. We analyzed the clonal rearrangements of the antigen receptors and bcl-2 gene, Epstein-Barr virus (EBV), and human T-cell leukemia virus type 1 (HTLV-I) by Southern blot and/or polymerase chain reaction (PCR), and performed in situ hybridization for mRNA of kappa and lambda immunoglobulin. Five cases showed rearrangements of immunoglobulin heavy chain gene (JH) and/or light chain gene (J kappa), and the monoclonal V-J recombination of JH in PCR. However, the rearranged bands were much more faint than was the germ-line band. We considered the monoclonal population of B cells small. Two of the five cases recurred locally after four and nine years respectively. Because benign lymphoid hyperplasias frequently contain an occult monoclonal B-cell population, a follow-up should be conducted. The remaining case in our investigation showed a rearrangement of the T-cell-receptor gene and proviral DNA of HTLV-I, and it showed rapid progress to adult T-cell leukemia after the biopsy. EBV and bcl-2 gene rearrangements were not observed in any of the six cases we studied.

Adult↗
PubMed1994

Monoclonal B cells and restricted oligoclonal T cells in T-cell-rich B-cell lymphoma.

Immunophenotyping of lymphoma using paraffin-embedded lymphoid tissue is useful in identifying the large neoplastic B cells in T-cell-rich B-cell lymphoma (TRBL), but does not succeed in deciding clonality. We studied six cases to determine the clonal population of B and T cells of TRBL. Immunohistochemistry on frozen and paraffin-embedded material showed that the cellular population in all six cases consisted mainly of T cells; fewer than ten percent of the cells stained as B cells. However, in all cases, monoclonality of the immunoglobulin was helpful for diagnosing the B-cell neoplasia. Southern blot-yielded genetic analysis showed monoclonality of B cells in three cases, but no evidence of clonality in the T cells. Moreover, gene monoclonality has been detected in all cases examined by polymerase chain reaction, using the primers for the V and J regions of the immunoglobulin heavy chain gene. For T cells, the D and J regions of the T-cell receptor (TCR) beta chain showed the same patterns of oligoclonal bands in all cells, and the V and J regions of the TCR gamma chain showed the same bands in all. The expression of TCR V beta families was polyclonal but restricted.

Aged↗
PubMed1994

A simple procedure for assigning a sequence motif with an obscure pattern: application to the basic/helix-loop-helix motif.

We have developed a simple method to assign a sequence motif with an obscure pattern. Given a multiple sequence alignment for a region of protein that is known or strongly believed to have the same secondary and tertiary structures, the quantification method by principal component analysis is designed to find the regions most likely to have the same structure in a protein outside of the original set. The potential of this newly developed method was evaluated with reference to the known basic/helix-loop-helix (bHLH) motifs, and its characteristics were discussed with four obscure but well-defined motifs and compared with the other methods for searching sequence motifs. The method was also applied to assign the bHLH motif in Epstein-Barr virus nuclear antigen 1 (EBNA-1). This application revealed one candidate for the basic/helix 1 region and two candidates for the helix 2 region in the bHLH motif, within the region from amino acid residues 460 to 600, which is in good agreement with our previous experimental studies on the DNA binding region of EBNA-1. The basic/helix-loop-helix-loop-helix structure thus assigned suggests a function of EBNA-1 which is associated with both replication and transcription.

Amino Acid Sequence↗
PubMed1994

Heterogeneity of Epstein-Barr virus infection in angioimmunoblastic lymphadenopathy type T-cell lymphoma.

To investigate the relationship of Epstein-Barr virus (EBV) and angioimmunoblastic lymphadenopathy with dysproteinemia, we performed DNA analysis using the polymerase chain reaction (PCR), Southern blot, in situ hybridization, and immunohistochemical analysis of lymph nodes in five patients who were followed up and biopsied more than once. In the course of the disease, nodal architecture diminished, cellular atypia worsened, and clear cells increased in number. In the DNA analysis of the receptor genes, the clonal population increased in number. EBV nucleic acid sequences were found by either PCR or in situ hybridization in all examined nodes. The number of EBV-positive cells varied widely among the cases and throughout the course of the disease in the same patients. The analysis of EBV terminal repeats or lymphocyte-determined membrane antigen genes showed polyclonal populations of EB-infected cells. EBV-positive cells possessed intermediate- to large-sized nuclei, and the cells with large nuclei, especially, expressed latent membrane protein of EBV. These large cells varied among the cases. Double-labelling immunohistochemistry/in situ hybridization studies demonstrated that most of the EBV-positive cells expressed B-cell antigen (CD20). The presence of EBV seems to be associated with the selective defects of the immune system, rather than with the direct pathogenesis of angioimmunoblastic lymphadenopathy.

Base Sequence↗
PubMed1994

Characterization and strain identification of a potato virus Y isolate non-reactive with monoclonal antibodies specific to the ordinary and necrotic strains.

An isolate of potato virus Y, named PVY-36, reacted with polyclonal antibody against PVY-O (an ordinary strain), but not with any of eight monoclonal antibodies (MAbs) specific to PVY-O or with two MAbs specific to PVY-T (a necrotic strain). From its host range and symptomatology, PVY-36 belongs to the PVYO group. The nucleotide sequence of the coat protein (CP) coding region of the PVY-36 genome was determined and the amino acid sequence was predicted. Based on the CP amino acid sequence, PVY-36 is more closely related to PVY-O than to PVY-T. There were eight amino acid differences between the CPs of PVY-36 and PVY-O in the N-terminal 30 amino acids. It is suggested that amino acids 8-15 and/or 26-30 from the N-terminus may determine a PVY-O-specific epitope (or epitopes).

Amino Acid Sequence↗
PubMed1994

Immunocytochemical characterization and identification of SGE1, a rat glomerular epithelial cell line.

Glomerular epithelial cells (GEC) in culture facilitate the study of glomerular physiology and pathology. However, characterization and identification of GECs in culture have been difficult due to the absence of markers specific to them. We compared the immunocytochemical characteristics of a rat normal GEC line (SGE1) and glomerular cells from rat kidney sections using a lectin and commercially available and newly raised monoclonal and polyclonal antibodies. Antivimentin, anti-dipeptidyl-peptidase-IV (gp 108) and monoclonal antibody 5-1-6 antibodies and Limax flavus lectin bound to visceral GECs, anticytokeratin antibody and antibody against common acute lymphocytic leukemia antigen bound to parietal GECs, and anti-SGE1 cell membrane and monoclonal antibody PHM 5 antibodies bound to both visceral GECs and parietal GECs in normal rat kidney sections, and all of these antibodies and L. flavus lectin consistently bound to SGE1 cells in culture. The pattern of antigenic expression on SGE1 cells indicates that SGE1 cells possess phenotypic characteristics of visceral GECs and parietal GECs, and it further suggests that SGE1 cells may be stem cells or cells undergoing differentiation.

Animals↗
PubMed1994

Retinoic acid enhances the number of epidermal growth factor receptors in rat glomerular epithelial cells in vitro.

The renal epithelium appears to be an important target tissue for retinoic acid and epidermal growth factor (EGF). We report here that retinoic acid enhances the proliferative effect of EGF on glomerular epithelial cells (GEC) in vitro and also increases EGF binding to GEC. When GEC were exposed to EGF (> or = 1 ng/ml), cellular DNA synthesis was markedly increased. Moreover, the stimulating effect of EGF was synergistically increased by retinoic acid at 5 micrograms/ml. 125I-EGF binding to cultured GEC was increased approximately 3-fold after addition of retinoic acid to cultures for 48 h. Analysis of 125I-EGF binding revealed 8.1 x 10(4) receptors per control (untreated) cell, while retinoic acid-treated cells demonstrated an increase to 14.3 x 10(4) receptors per cell with no detectable change in receptor affinity. These findings suggest that interactions between retinoic acid and EGF may play an important role in the regulation of GEC growth.

Animals↗
PubMed1994

Clonal analysis of Hodgkin's disease shows absence of TCR/Ig gene rearrangement, compared with T-cell-rich B-cell lymphoma and incipient adult T-cell leukemia/lymphoma.

To better characterize the clonality and pathogenesis of Hodgkin's disease (HD), we used polymerase chain reaction (PCR) and Southern blot to analyze the rearrangement of immunoglobulin (Ig) and T-cell receptor (TCR) genes, the bcl-2 oncogene, and the Epstein-Barr virus (EBV) genotype. In situ hybridization studies of EBV were also done. Twenty-six cases of HD were compared with 15 cases of non-specific lymphadenitis, 7 with incipient adult T-cell leukemia/lymphoma (ATLL), and 4 T-cell rich B-cell lymphomas (TRBL), all of which histologically resembled HD. EBV genes were detected in 20 of 26 HD patients (77%) and in 7 of 15 patients with non-specific lymphadenitis (47%), 5 of 7 with incipient ATLL (71%), and 1 of 4 with TRBL (25%). In contrast to specimens of non-specific lymphadenitis, TRBL, and incipient ATLL, only one EBV genotype was evident in the specimens of HD. EBV latent membrane protein (LMP) was detected immunologically in 16 of 26 HD patients (62%), one of four TRBL (25%) and one of seven incipient ATLL (14%), but it was not evident in non-specific lymphadenitis. The LMP positive cases showed amplified EBV genomes. Only one of the 26 cases of HD had a bcl-2 gene rearrangement by PCR, but this was not seen in any other disease. The bcl-2 protein was detected immunologically in seven of the 26 HD patients (27%) and in one of the seven incipient ATLL cases (14%). EBV has been reported to upregulate bcl-2 expression, but in this study the presence of bcl-2 protein did not correlate with the presence of the t(14;18) translocation or EBV-LMP. All TRBLs showed rearrangement of the immunoglobulin genes by PCR and/or Southern blot, and the giant cells were of B-cell type. All incipient ATLLs displayed rearrangement of the TCR genes, and the giant cells were of T-cell origin. In seven of 26 HD cases, the giant cells were weakly stained with T-cell antibodies, in another seven positive with B-cell antibodies and in 18 instances polyclonally positive for both kappa and lambda. However, PCR and Southern blot displayed only two cases of TCR gene rearrangement, while two others had very weak rearrangements of immunoglobulin gene positive only by PCR. Thus the T and B-cell genotype did not correlate with the T and B-cell phenotype recorded in these cases. The absence of Ig and TCR gene rearrangements seems to be common in HD, compared with in TRBL and incipient ATLL.

Base Sequence↗
PubMed1994

Hepatocyte growth factor is a potent promoter of mitogenesis in cultured rat visceral glomerular epithelial cells.

Hepatocyte growth factor (HGF) was originally identified as an hepatotrophic factor inducing liver regeneration, and was also recently found to stimulate mitogenesis of various epithelial cells. In the present study, we examined the mitogenic effects of native and recombinant HGF on cells of rat visceral glomerular epithelial cell line (SGE1). Native and recombinant HGF each stimulated DNA synthesis in and growth of SGE1 cells to a remarkable degree. These mitogenic activities were dose-dependent, being detectable at 2.5 ng/ml and maximal at 20 ng/ml. Over 30% of SGE1 cells tested were shifted to S-phase by HGF alone, as judging by labeling index values. DNA synthesis stimulated by native or recombinant HGF was high at low SGE1 cell density and was strongly suppressed at high cell density. DNA synthesis in and growth of SGE1 cells were stimulated more strongly by recombinant HGF than by native HGF. In addition, the effects of recombinant HGF and epidermal growth factor were additive, while transforming growth factor-beta 1 strongly inhibited the stimulation of DNA synthesis by recombinant HGF. These findings suggest that HGF may play a role in controlling visceral glomerular epithelial cell growth.

Animals↗
PubMed1994

EM574, an erythromycin derivative, is a potent motilin receptor agonist in human gastric antrum.

Erythromycin and its derivatives are known to induce phase III-like contractions, which are similar to those induced by motilin, in the human gastrointestinal tract during the interdigestive state, but few detailed in vitro studies have been reported. We evaluated EM574, an erythromycin derivative, as a motilin receptor agonist in the human gastric antrum in vitro, using contraction studies of muscle strips and isolated myocytes, receptor binding assay and tissue section autoradiography. EM574 stimulated contractions of muscle strips in a concentration-dependent manner (10(-7)-10(-5) M), and this contractile effect was unaffected by pretreatment with atropine or tetrodotoxin. Isolated myocytes contracted in response to EM574 with a peak shortening at 10(-7) M, which was comparable to the response to motilin. EM574 displaced specifically 125I-motilin bound to smooth muscle homogenates with a Kd value of 7.8 x 10(-9) M, compared with 4.5 x 10(-9) M for motilin. Film autoradiograms showed that 125I-motilin-binding sites were localized in the muscle layers, and that the labeling disappeared in the presence of a 1000 times molar concentration of EM574. We conclude that EM574 directly stimulates smooth muscle cell contraction by acting on motilin receptors in the human gastric antrum in vitro.

Autoradiography↗
PubMed1994

[A multicenter clinico-epidemiological study of HTLV-I associated uveitis].

To elucidate the clinical and epidemiologic features of HTLV-I associated uveitis (HAU), a multicenter case-control study was performed by collaboration of university hospitals throughout Kyushu and Okinawa and two university hospitals in the central metropolitan area. A total of 426 cases of endogenous uveitis were collected and studied between September 1992 and January 1993; about half of the cases were definable for etiology or clinical entity, and the remaining cases were unknown. Assessment of the serum antibodies to HTLV-I revealed that the group of entity-undefined uveitis had a significantly high prevalence of HTLV-I as compared with the age- and sex-matched control subjects, giving supportive evidence for HAU. The titer of serum HTLV-I antibodies was significantly higher in entity-undefined uveitis than in HTLV-carriers. Assuming that a collection of 50 cases of HTLV-I seropositive, etiology-undefined uveitis represents HAU, its clinical features consisted were: (1) middle-aged, otherwise healthy adults developed acute inflammatory uveal disease and presented with visual haze and/or floaters; (2) the disease showed granulomatous or nongranulomatous anterior uveal reactions accompanied by vitreous opacities and retinal vasculitis; (3) the lesions resolved in response to topical or systemic corticosteroids; (4) the visual outcome was usually favorable; (5) nearly half of the cases had recurrent disease; (6) the cases remained systemically unremarkable, except for two cases of HTLV-I associated myelopathy and eight cases of hyper thyroid disease.

Adolescent↗
PubMed1994

[A concomitant operation of coronary artery bypass grafting and thymectomy: a case report].

A 63-year-old man was successfully operated upon concomitantly for coronary artery disease and invasive thymoma. The chest roentogenogram showed a mass shadow in the anterior mediastinum, which was 6.0 x 4.0 cm in size and irregular. Coronary angiography revealed complete obstruction of the right coronary artery and 90% stenosis of the first diagonal branch (#9). Following thymectomy combined with the resection of the left phrenic nerve and the mediastinal pleura, coronary artery bypass grafting with the major saphenous vein was performed to #4 PD and #9. This is the first report of concomitant surgery for the ischemic heart disease and invasive thymoma in Japan.

Coronary Artery Bypass↗
PubMed1994

Immunopathologic study and characterization of the phenotype of transformed cells in sheep with bovine leukemia virus-induced lymphosarcoma.

We used monoclonal antibodies and immunohistologic examination of lymph nodes, to elucidate the pathogenesis of lymphosarcoma induced by infection with bovine leukemia virus (BLV). The superficial cervical lymph nodes from 3 BLV-infected but apparently healthy sheep and 5 sheep with full-blown lymphosarcoma were examined. We also investigated the integration of bovine leukemia provirus by use of Southern blotting. In lymph nodes from sheep lacking clinical signs of infection, in which the provirus had been integrated at multiple sites in the genome, many large hypertrophic follicles were observed in the cortex. These follicles had germinal centers consisting of CD4+T cells and B cells that expressed surface IgM (sIgM) and major histocompatibility complex (MHC) class-II antigens, but not B cell-specific B2 molecule. The percentage of CD4+T cells in the cortex was significantly (P < 0.05) higher than that of the controls and sheep with lymphosarcoma. In all sheep with lymphosarcoma, the lymph nodes were completely destroyed by proliferating neoplastic cells, and in addition, small atrophic follicles, which consisted of normal B-cell marker-positive cells, were seen near the trabecula and the subcapsule. In these instances, neoplastic cells appeared to be a monoclonal population derived from a single CD5- B-cell lineage and to be classified as 2 types, CD5-CD4-CD8-B2+MHC class-II+sIgM+ and CD5-CD4-CD8-B2+MHC class-II+sIgM-. Moreover, CD8+T cells infiltrated diffusely throughout the tumorous lymph nodes apart from the atrophic follicles, and CD4+ cells were observed around atrophic follicles. Both types of T cells were small-size, normal lymphocytes with round and noncleaved nuclei, and were apparently non-neoplastic cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗