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Biomedical subjects

S Sakiyama

Publications and source records attributed to S Sakiyama.

At least 127 records · Page 7Linked to original sources
PubMed1995

Clinical features of childhood-onset schizophrenia with obsessive-compulsive symptoms during the prodromal phase.

Thirty-nine patients with schizophrenia, diagnosed according to DSM-III-R, who were under 15 years of age, were studied in two groups; 16 subjects with obsessive-compulsive symptoms during the prodromal phase, and 23 with no obsessive-compulsive disorders. The group with obsessive-compulsive symptoms during the prodromal phase was characterized by a higher ratio of males, higher incidences of perinatal and brain computed tomography (CT) abnormalities, fewer hereditary factors, longer duration of the prodromal phase, and a higher incidence of insidious onset and negative symptoms compared with the group without such prodromal symptoms. Schizophrenic patients with obsessive-compulsive symptoms during the prodromal phase were clinically distinct from those without, which suggests the possibility of subtype categorization.

Adolescent↗
PubMed1994

Expression of a calcium binding protein pEL98 (mts1) during differentiation of human promyelocytic leukemia HL-60 cells.

The expression of pEL98 (also termed mts1), an S100-related calcium-binding protein, was induced during macrophagic or granulocytic differentiation of human promyelocytic leukemia HL-60 cells in response to phorbol 12-myristate 13-acetate or dimethylsulfoxide, respectively. However, pEL98 expression remained at the low level during granulocytic differentiation of the cells by the treatment with all-trans retinoic acid. The expression of cell motility, but not adhesiveness or phagocytic ability, was found to be coincided with that of pEL98 (mts1), suggesting that pEL98 (mts1) is involved in regulating cell motility. Immunocytochemical analysis demonstrated that pEL98 (mts1) was expressed in human monocytes, macrophages and polymorphonuclear leukocytes.

Blotting, Northern↗
PubMed1994

Tumor-suppressive activity of N03 gene product in v-src-transformed rat 3Y1 fibroblasts.

The expression of the N03 gene was significantly reduced in a variety of transformed cells, compared with that in parental rat 3Y1 fibroblasts. To understand the possible role(s) of its product, we have obtained transfectants expressing N03 gene from v-src-transformed 3Y1 cells. Two clones, which overexpressed N03 mRNA, showed a flatter phenotype, a reduced rate of growth, and a decreased ability to grow in soft agar. One of the clones which maintained N03 expression was completely suppressed in forming tumors in nude mice. These data suggest that the N03 gene product may have a suppressive ability on transformed phenotypes.

Animals↗
PubMed1994

Molecular cloning and characterization of a cDNA showing tumor-suppressive activity in V-SRC-transformed 3Y1 rat fibroblasts.

Differential screening procedure was employed to isolate new genes specifically down-regulated in RSV-transformed rat 3Y1 cells (SR-3Y1) compared with parental 3Y1 cells. Among those, one clone termed N03 showed nearly complete down-regulation in v-src-, v-mos and SV40-transformed 3Y1 cells. Nucleotide sequence analysis showed that N03 protein is novel and is composed of 178 amino acid residues in length. Introduction of N03 cDNA into SR-3Y1 cells using an expression vector resulted in suppression of transformed phenotypes such as high growth rate, colony-forming ability in soft agar and tumorigenicity in nude mice.

Amino Acid Sequence↗
PubMed1994

Binding of pEL98 protein, an S100-related calcium-binding protein, to nonmuscle tropomyosin.

The cDNA coding for mouse fibroblast tropomyosin isoform 2 (TM2) was placed into a bacterial expression vector to produce a fusion protein containing glutathione-S-transferase (GST) and TM2 (GST/TM2). Glutathione-Sepharose beads bearing GST/TM2 were incubated with [35S]methionine-labeled NIH 3T3 cell extracts and the materials bound to the fusion proteins were analyzed to identify proteins that interact with TM2. A protein of 10 kD was found to bind to GST/TM2, but not to GST. The binding of the 10-kD protein to GST/TM2 was dependent on the presence of Ca2+ and inhibited by molar excess of free TM2 in a competition assay. The 10-kD protein-binding site was mapped to the region spanning residues 39-107 on TM2 by using several COOH-terminal and NH2-terminal truncation mutants of TM2. The 10-kD protein was isolated from an extract of NIH 3T3 cells transformed by v-Ha-ras by affinity chromatography on a GST/TM2 truncation mutant followed by SDS-PAGE and electroelution. Partial amino acid sequence analysis of the purified 10-kD protein, two-dimensional polyacrylamide gel analysis and a binding experiment revealed that the 10-kD protein was identical to a calcium-binding protein derived from mRNA named pEL98 or 18A2 that is homologous to S100 protein. Immunoblot analysis of the distribution of the 10-kD protein in Triton-soluble and -insoluble fractions of NIH 3T3 cells revealed that some of the 10-kD protein was associated with the Triton-insoluble cytoskeletal residue in a Ca(2+)-dependent manner. Furthermore, immunofluorescent staining of NIH 3T3 cells showed that some of the 10-kD protein colocalized with nonmuscle TMs in microfilament bundles. These results suggest that some of the pEL98 protein interacts with microfilament-associated nonmuscle TMs in NIH 3T3 cells.

3T3 Cells↗
PubMed1994

Involvement of S100-related calcium-binding protein pEL98 (or mts1) in cell motility and tumor cell invasion.

We examined the relationship between cell motility and the expressions of pEL98 (mts1) mRNA and protein in various murine normal and transformed cells. The expression of pEL98 (mts1) in v-Ha-ras-transformed NIH3T3 cells and in normal rat kidney cells transformed by either v-Ha-ras or v-src was increased over that in the corresponding parental cells at both mRNA and protein levels. The expression in normal rat fibroblasts (3Y1) transformed by v-Ha-ras was also increased compared with that in 3Y1 cells. However, the expression of pEL98 (mts1) in 3Y1 cells transformed by v-src was increased in one clone (src 3Y1-K), but decreased in another clone (src 3Y1-H). The expression level of pEL98 (mts1) correlated well with cell motility, which was examined by measuring cell tracks by phagokinesis. In order to test direct involvement of the pEL98 (mts1) protein in cell motility, src 3Y1-H cells that showed low cell motility were transfected with pEL98 cDNA. The transfectants expressing large amounts of the pEL98 protein showed significantly higher cell motility than src 3Y1-H cells. The expression of pEL98 (mts1) was also found to be correlated with motile and invasive abilities in various clones derived from Lewis lung carcinoma. These results suggest that the pEL98 (mts1) protein plays a role in regulating cell motility and tumor cell invasiveness.

3T3 Cells↗
PubMed1994

Pleural-changes in the lung allograft during acute rejection.

To ascertain the cause of pleural fibrosis in lung allografts, pleural changes were investigated in rat syngeneic and allogeneic lung grafts. The pleura of lung syngeneic grafts showed no pathological changes except for mild edema on the first day after transplantation. In lung allografts, recipient cells migrated into the subpleural tissue early after transplantation (latent phase). In the vascuar phase, recipient lymphocytes in the subpleural tissue increased in number, while almost all alveolar structures were free from infiltration. Both CD4-positive and CD8-positive cells infiltrated in almost equal numbers with macrophages. The subsets of infiltrating cells were similar to those of the perivascular and peribronchial areas. In the late vascular or alveolar phase, fibroblasts were observed among the infiltrating cells, and fibrotic changes started. In the destructive phase, collagen formation with marked pleural thickening was dominant. Pulmonary acute rejection should be treated at least up to the late vascular phase to prevent pleural fibrosis.

Acute Disease↗
PubMed1994

Pathogenesis of late airway changes in long-term surviving lung allografts.

Late airway changes are frequently observed in long-term surviving rat lung allografts. In this present study, we investigate this problem using the mixed lymphocyte reaction, graft-versus-host assay (popliteal lymph node assay), skin grafting from the donor strain to the lung allograft recipient, and histology to evaluate this problem. The results show that spleen cells from recipient rats with long-term surviving lung allografts possessed alloreactivity in mixed lymphocyte reaction against both donor and third-party ACI antigens. Suppressor cell activity was not detected in spleen cells from these recipient rats. The popliteal lymph node assay showed that the response to recipient spleen cells was detectable but weaker than that of naive spleen cells from the same strain. Mean survival time of skin grafts from the donor strain to long-term allograft survivors was significantly longer than that between donor and recipient strains. Chest roentgenograms revealed opacification of long-term surviving lung allografts at 2 to 3 wk after skin transplantation that was coincident with the rejection of the skin grafts, and histologic examination of the lung allografts revealed changes compatible with acute rejection. We conclude that alloreactivity can be demonstrated in rats with long-term surviving lung allografts and suggest that late airway changes in these lungs are immunologically mediated.

Animals↗
PubMed1994

Cellular localization of pEL98 protein, an S100-related calcium binding protein, in fibroblasts and its tissue distribution analyzed by monoclonal antibodies.

Two monoclonal antibodies (named mAb3G4 and mAb4A2) against recombinant pEL98 protein have been produced. The specificity of the mAbs was verified by immunoblot and immunoprecipitation analyses. To determine cellular localization of the pEL98 protein in NIH3T3 and 3Y1 cells, indirect immunofluorescent staining was performed using mAb4A2. The results showed that most of the pEL98 protein existed diffusely in the cytoplasm, while a part of the protein existed along actin stress fibers in both cells. The expression of pEL98 protein in various murine and human tissues and cells was also examined by immunoblot analysis using mAb3G4. The results demonstrated that the pEL98 protein was expressed in bone marrow, spleen, peritoneal macrophages and human lymphocytes, with the highest amount found in peritoneal macrophages.

3T3 Cells↗
PubMed1994

Identification of a rat protein tyrosine phosphatase gene preferentially expressed in the embryonal brain.

We have identified a novel protein tyrosine phosphatase gene from an embryonal rat brain by reverse transcription-based polymerase chain reaction. Its transcription is specific to brain and is developmentally regulated, as it is expressed at high levels in embryonal and neonatal stages but scarcely in an adult. Southern blot analysis indicates that the gene exists as a single copy and is conserved among various species. Homology search of the deduced amino acid sequence suggests that this gene belongs to the same family of the membrane-type tyrosine phosphatase gene of Drosophila (DPTP10D), whose expression is specific to an central nervous system of fly embryo.

Aging↗
PubMed1994

Expression of protein tyrosine phosphatase genes in the developing brain of mouse and rat.

We have examined the expression of protein tyrosine phosphatase genes in the embryonic brain of mouse and rat with reverse transcription-polymerase chain reaction. Several receptor and cytoplasmic types of tyrosine phosphatase genes were detected. Among them a novel gene was identified from mouse and rat brain, respectively. The partial amino acid sequences reveal that the new genes found in the developing brain of mouse and rat are homologous each other. Since they retain conserved phosphatase sequences, they may represent a family of protein tyrosine phosphatase gene that is commonly expressed in rodent brain.

Amino Acid Sequence↗
PubMed1994

Complex formation between lamin A and the retinoblastoma gene product: identification of the domain on lamin A required for its interaction.

The retinoblastoma susceptibility gene product (pRB) has been known to function as a negative regulator of cell growth. Recent observations suggest that its biological activity might be modulated by an interaction with nuclear structures. By using in vitro binding assays, we have found that pRB can associate with lamin A, which has been known to be one of the major nuclear matrix proteins. A series of GST-lamin A deletion mutants was constructed to define the amino acid sequence required for binding to pRB. A GST-lamin A (247-355) contained an activity to associate with pRB, while the other constructs, such as GST-lamin A (37-244) or GST-lamin A (356-571), could not bind to pRB. Within the pRB-binding domain of lamin A, there exists the short amino acid sequence which is also present in the pRB-binding region of the transcription factor E2F-1. The similar experiments using a set of GST-RB deletion mutants revealed that a region containing the E1A-binding pocket B and the carboxy-terminal portion of pRB was responsible for binding to lamin A.

Amino Acid Sequence↗
PubMed1993

c-Ha-Ras mutants with point mutations in Gln-Val-Val region have reduced inhibitory activity toward cathepsin B.

Protease-inhibitory activity of recombinant Ha-ras gene products (Ras) toward papain and cathepsins B and L was investigated. v-Ha-Ras showed more potent inhibitory activity toward cathepsin B as compared with c-Ha-Ras. We have also investigated protease-inhibitory activity of c-Ha-Ras mutants with point mutations in amino acids between positions 23 and 50. Inhibitory activity of Ras toward papain and cathepsin L was not largely altered among mutants. However, the inhibitory activity toward cathepsin B was significantly impaired by a mutation at position 43, 44, 45 or 48. These results suggest that 43Gln-Val-Val sequence plays an important role at least to inhibit cathepsin B.

Amino Acid Sequence↗
PubMed1993

Molecular cloning and characterization of a cDNA showing negative regulation in v-src-transformed 3Y1 rat fibroblasts.

A differential screening procedure was used to isolate genes that are specifically down-regulated in transformed cells. After screening a cDNA library derived from normal rat fibroblast (3Y1) cells, we obtained several independent cDNAs whose mRNA level was substantially lower in 3Y1 cells transformed with Rous sarcoma virus than in untransformed 3Y1 cells. Among them, N03 cDNA has been characterized extensively. N03 mRNA was also absent from v-mos- or simian virus 40-transformed 3Y1 cells but was present in v-Ha-ras-transformed 3Y1 cells. Nucleotide sequence analysis showed that the N03 protein is composed of 178 amino acid residues and does not have any sequence similarities with proteins in the data base. A putative zinc-finger domain is located in the central part of the sequence and a proline-rich domain is in the C-terminal region. N03 mRNA was detected by Northern blot analysis in several tissues, including lung, kidney, intestine, and brain, but not in liver. Genomic Southern blot hybridization revealed that the N03 gene exists as a single copy in the rat genome and that closely related, single-copy genes are also present in chicken and human.

Amino Acid Sequence↗
PubMed1993

v-Ha-Ras insertion/deletion mutants with reduced protease-inhibitory activity have no transforming activity.

We have purified 26 insertion/deletion mutants of v-Ha-ras oncogene products produced by Escherichia coli and investigated their protease-inhibitory activity toward papain and cathepsins B and L. Ki values for papain were relatively similar among the mutants, however, those for cathepsins B and L varied up to 10-fold. Among them, four mutants, 1-48 LIR 54-189, 1-110 LIS 112-189, 1-130 PDQ 146-189 and 1-155 LIR 166-189, showed significant reduction in the inhibitory activity toward cathepsin L and these four mutants have lost transforming activity toward NIH3T3 mouse fibroblasts. However, some other mutants also showed no transforming activity in spite of possession of the potent protease-inhibitory activity, suggesting that the protease-inhibitory activity of Ras might be necessary but not sufficient for its biological activity.

3T3 Cells↗
PubMed1993

Intractable chest pain in a patient whose postpneumonectomy space was managed with sulfur hexafluoride.

A 50-year-old man who had undergone right pneumonectomy 1 year previously was referred to our department following the sudden onset of severe chest pain. Since the operation, his postpneumonectomy space had been managed with sulfur hexafluoride. On admission, the pressure in the postpneumonectomy space was found to be more than +60 cmH2O. The chest pain was relieved after the sulfur hexafluoride had been drained and the pressure released. Thus, it is advisable to inject sulfur hexafluoride stepwise into the postpneumonectomy space of patients with long-standing fluid accumulation.

Diagnosis, Differential↗
PubMed1993

Replacement of dendritic cells in the airways of rat lung allografts.

It is unknown whether dendritic cells are able to migrate normally from the recipient into the allogeneic lung graft. Using monoclonal antibodies to major histocompatibility complex class II antigens (OX6 for both donor and recipient types; HIS19 for recipient type), we studied the replacement of donor dendritic cells by recipient type cells in rat lung allografts that are indefinitely accepted with a short course of cyclosporine early after transplantation. The recipient dendritic cells started to migrate into lung allografts early (by 1 wk) after transplantation. Donor dendritic cells in the grafts were replaced by recipient cells during the first 2 months after transplantation. Dendritic cells in the perivascular tissue were replaced quickly, most of them within 1 wk, whereas those in the alveolar septa were replaced slowly. In the lung allograft surviving 2 or more months, the normal phenotypic heterogeneity of dendritic cells was preserved. Recipient dendritic cells accumulated in dense peribronchial aggregates that remained 6 months. The dendritic aggregates were associated with late airway changes in allografted lungs. The abnormal accumulation of dendritic cells peribronchially might be related to an abnormal mucosal immune response or a chronic rejection process.

Animals↗