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Biomedical subjects

T Nakatsuji

Publications and source records attributed to T Nakatsuji.

At least 19 recordsLinked to original sources
PubMed2003

High levels of serum soluble CD27 correlated with renal dysfunction.

CD27 is expressed on lymphocytes, but also on renal tubules. On the damaged renal tubules, CD27 is cleaved into soluble CD27 (sCD27) and cytoplasmic tail CD27. Renal tubule apoptosis is induced by the CD27 ligand, Siva, binding to the truncated tail CD27. Theoretically, serum sCD27 should be a marker of renal tubule apoptosis. Serum sCD27 levels were measured by ELISA in 274 patients at University Hospital School of Medicine, Japan. Among 73 males and 63 females with high plasma creatinine levels, 68 (93%) males and 51 (81%) females showed high serum sCD27 values (>or=500 U/ml). In the 42 males with plasma creatinine levels of 1.18-5.00 mg/dl and the 55 females with plasma creatinine levels of 0.83-4.65 mg/dl, the correlation coefficients between plasma creatinine and sCD27 were 0.605 and 0.469, respectively. SCD27 was a more sensitive marker of renal tubule apoptosis than plasma creatinine. Of 138 patients with normal plasma creatinine, 42 showed high serum sCD27 levels (>or=500 U/ml). Among the 42 patients, 19 patients had high blood urea nitrogen and 11 patients showed plasma creatinine elevations 3-11 days later. Nine patients with hemolysis and 39 patients with aneurysms had clearly higher sCD27 levels of 1633+/-483 U/ml and 905+/-437 U/ml, respectively, than normal values of 215+/-57 U/ml ( n=27) ( P value >or=0.001). Vasodilators, hypotensors, diuretics, and drugs for gout, arrhythmia, thrombosis, and diabetes were prescribed in 40%, 37%, 33%, 13%, 8%, 8%, and 5% of the 78 patients analyzed with high sCD27 levels (>or=500 U/ml). In total, 59 (76%) patients were prescribed at least one of the drugs. In conclusion, serum sCD27 was a more sensitive indicator of renal tubule apoptosis than plasma creatinine, especially during the early stage of apoptosis. Tubule apoptosis with high serum sCD27 levels was found in patients with glomerular vascular injuries.

Aneurysm↗
PubMed2001

The molt-inhibiting hormone in the American crayfish Procambarus clarkii: its chemical synthesis and biological activity.

The molt-inhibiting hormone of the American crayfish Procambarus clarkii (Prc-MIH), a 75-residue polypeptide containing three disulfide bridges, was synthesized by chemical ligation of two peptides, i.e., synthetic Prc-MIH(1-39) and Prc-MIH(40-75)-NH(2), and by subsequent folding to form the native disulfide-containing peptide molecule. The synthetic peptide was comparable to the natural Prc-MIH in inhibiting ecdysteroid secretion by in vitro bioassay and shared features with the natural Prc-MIH in some biochemical analyses. These results indicate that the chemical ligation method can be used for the synthesis of Prc-MIH. Furthermore, it was demonstrated that synthetic Prc-MIH has hyperglycemic activity, although the activity was weaker than that of the authentic crustacean hyperglycemic hormone in the American crayfish. To examine the structural requirement of the Prc-MIH for eliciting biological activity, an antibody raised against the C-terminal region (residues 55-75) and two synthetic peptides, i.e., a core region (residues 1-54) containing three disulfide bridges and the C-terminal region, were utilized. It is suggested that Prc-MIH exerts its activities through coordination between the core region and the C-terminal region.

Animals↗
PubMed2001

Mesoderm formation by isolated and cultivated 8-cell stage blastomeres of the teleost, Leucopsarion ptersii (shiro-uo).

Isolation of cleavage-stage blastomeres and the study of their developmental potential has been used extensively for analyzing the mechanisms of embryogenesis in vertebrates, including amphibians and echinoderms. We devised a method to isolate 8-cell stage blastomeres in the teleost, shiro-uo, by utilizing its unique cleavage pattern of the horizontal 3rd cleavage plane. Removal of all the upper blastomeres at the 8-cell stage allowed almost normal embryogenesis from the remaining lower blastomeres and yolk cell mass. Isolated upper or lower blastomeres formed vesicles and spherical bodies, which later showed morphological changes during cultivation. Mesoderm formation was detected not only in the cultivated lower blastomeres or whole blastomeres but also in the upper blastomeres isolated from the yolk cell mass at the 8-cell stage, although at a lower frequency than the lower blastomeres. These results indicated the presence of very early signaling for mesoderm induction, which is independent from the currently postulated signals from the yolk syncytial layer at later stages. This also indicated non-equivalence or differentiation of the blastomeres from the very early cleavage stage in teleost embryos.

Amino Acid Sequence↗
PubMed2000

Synthesis of a molt-inhibiting hormone of the American crayfish, Procambarus clarkii, and determination of the location of its disulfide linkages.

A molt-inhibiting hormone (Prc-MIH) of the American crayfish, Procambarus clarkii, a member of the type II CHH family, was chemically synthesized and the location of its three disulfide linkages was determined. Prc-MIH consists of 75 amino acid residues and was synthesized by a thioester method. Two peptide segments, Boc-[Cys(Acm)(7,24,27), Lys(Boc)(19)]-Prc-MIH(1-39)-SCH(2)CH(2)CO-Nle-NH(2) and H-[Cys(Acm)(40,44,53), Lys(Boc)(42,51,67)]-Prc-MIH(40-75)-NH(2), were prepared using peptides obtained via the Boc solid-phase method. Condensation of the building blocks in the presence of silver chloride, 3,4-dihydro-3-hydroxy-4-oxo-1,2,3-benzotriazine, and N, N-diisopropylethylamine, followed by removal of the protecting groups, gave the reduced form of Prc-MIH(1-75)-NH(2). This product was converted to the native form of Prc-MIH (synthetic Prc-MIH) in a buffer which contained cysteine and cystine. The synthetic Prc-MIH showed the same behavior by RP-HPLC and biological activity assays as the natural Prc-MIH. The disulfide bond between Cys7 and Cys44 was determined by isolation of a fragment from an enzymatic digest of the synthetic Prc-MIH by RP-HPLC, followed by mass analysis. The disulfide bonds between Cys24 and Cys40 and between Cys27 and Cys53 were determined by comparing the elution position of an enzymatic digest of the synthetic Prc-MIH with authentic chemically synthesized samples, which contained three types of possible disulfide linkages.

Animals↗
PubMed1999

Better-surviving liver grafts by the injection of anti-CD2 antibody: the important roles of host CD8+ and CD2+CD28+ T cells in chronic graft rejection and beta type platelet-derived growth factor receptor (PDGFR-beta) expression on apoptotic liver grafts.

Syngeneic liver grafts were implanted in the livers of 22 LEW/Sea strain rats. To prolong the graft survival, anti-CD2 monoclonal antibody (MAb) or anti beta type platelet-derived growth factor receptor (PDGFR-beta) antibody (Ab) was injected, or splenectomy was performed in the rats which were then followed until 10 to 11 weeks posttransplantation. The 22 rats with chronic graft rejection showed increased CD8a-like antigen (probably Fas ligand) on the peripheral blood T cells. All the liver grafts had both necrosis and apoptosis. The liver graft apoptosis was indicated by histopathological abnormalities, and by DNA strand breaks and hemosiderin depositions in the cytoplasm. PDGFR-beta expression in the apoptotic liver graft was demonstrated immunohistochemically. Among the 17 rats injected with anti-CD2 MAb, CD2 signaling on host T cells was effectively suppressed by the injection of anti-CD2 MAb in 4 rats with better-surviving liver grafts. In these 4 rats, CD28 antigen on thymic lymphocytes was down-modulated and high numbers (136-233-positive cells per lobe) of the epithelial reticular cells with apoptotic lymphocytes were counted. Anti-PDGFR-beta Ab caused high pulmonary secretions of growth factors and reticular fibrosis in the lungs of 5 rats injected with the Ab. Anti-PDGFR-beta Ab injection reduced the host cell apoptosis in the lung and thymus, but did not prolong the survival of liver grafts. In the 9 rats with both splenectomy and anti-CD2 MAb injection, pulmonary apoptosis was induced with the 6-16% reductions of CD4+ lymphocytes. Prolonged graft survival was observed in only one of the 9 rats. Anti-CD2 MAb was effective for prolonging the liver graft survival with suppressed CD28 antigen, but anti-PDGFR-beta Ab and splenectomy were not.

Animals↗
PubMed1998

T cell hypofunctions and glomerular sclerotic and angiogenic changes found both in rats received unilateral nephrectomy plus transplantation of syngeneic mesenteric lymph nodes and in rats received unilateral nephrectomy plus splenectomy.

Five male and 7 female Lewis rats unilaterally nephrectomized at the ages of 44-46 days were transplanted with the mesenteric lymph nodes (MLN) obtained from syngeneic rats 4 months after the nephrectomy. In addition, 6 males received unilateral nephrectomy plus splenectomy at the age of 38 days. All of these rats were observed for 8.5 months after the nephrectomy. Flow cytometry analyses indicated that 17-32% of MLN lymphocytes and 4-20% of peripheral blood (PB) lymphocytes lost CD2 antigen in the unilaterally nephrectomized rats. Approximately 20% of PB and MLN lymphocytes had lost CD2 antigen in the males with combined splenectomy and nephrectomy, one of which died of severe infection. The survival rates of the MLN graft after 4.5 months were 100% in the 5 nephrectomized males and 14% in the 7 nephrectomized females. The CD2 antigen on immunologically activated T cells was up-regulated. Twenty-eight% lymphocytes of the survived MLN graft and 51% PB T cells of the 7 females with MLN graft rejection showed the CD2 up-regulation. It was shown immunohistochemically that not only CD2-positive (+) cells but also CD4+ cells were increased in the cortex of the survived MLN graft. The hepatocyte growth factor receptor gene, c-met gene, was shown to be present in lymphocytes. The c-met was considered to cooperate with the CD2. Interstitial mononuclear cell infiltrations with glomerulosclerosis were found in the remaining kidneys of the males with unilateral nephrectomy plus MLN grafts. Glomerular angiogenesis and accompanying endothelial cell apoptosis were demonstrated without mesangial cell proliferation in the males with unilateral nephrectomy plus splenectomy.

Animals↗
PubMed1998

One Lewis rat with homozygous defect of the serine proteinase inhibitor 2 (Spi-2) gene and two Lewis rats with heterozygous Spi-2 gene defect.

One LEW/Sea (Lewis) strain rat, Rat P-1, had a homozygous defect of the serine proteinase inhibitor 2 (Spi-2) gene coding for serpin contrapsin. A sibling, Rat P-2, and a rat of the same strain, Rat P-3, had a heterozygous Spi-2 gene defect. The homozygous Spi-2 gene defect of Rat P-1 was diagnosed by the polymerase chain reaction (PCR). The presence of an alpha 1-proteinase inhibitor (PI) gene was confirmed by PCR in all 3 rats. Rat P-1 and the sibling Rat P-2 were sacrificed at 7 days of age because of the severe weakness of Rat P-1, although Rat P-2 appeared healthy. Rat P-3 was sacrificed at 40 days of age because of the severe weakness. Rat P-1's hepatocytes with the homozygous Spi-2 gene defect showed massive accumulation of polymerized alpha 1-antitrypsin (AT) in the rough endoplasmic reticulum (RER). Large, defined accumulations of alpha 1-AT were not found in the heterozygous rats with the Spi-2 gene defects. Nephrogenesis was retarded in all 3 rats, especially in Rat P-1. Extramedullary hematopoiesis was absent in the liver of Rat P-1 and suppressed in the spleen of Rat P-3, where activated alpha 1-AT synthesis was found. Atelectasis mixed with hyperinflated lung regions and thymic apoptosis were observed in the 2 weak rats. As Spi-2 gene defect had some similar clinical points to platelet-derived growth factor (PDGF) deficiency, it was suggested that increased vasoconstrictor peptide hormones competed with PDGF for binding to the PDGF-receptors.

Animals↗
PubMed1997

Differential and constitutive expression of the DRB1 and DRA gene products controls the surface HLA-DR expression level in human eosinophilic leukaemia cell lines.

Use of 2-D gel and imaging plate analysis enabled biosynthetically radiolabeled immunoprecipitates to be quantitated at the very low level of gene products during processing from RER inside cells to cell surface. We used this efficient and sensitive measurement to analyse expression of HLA-DR molecules in human eosinophilic leukaemia cell lines. We found that they synthesized a constitutive amount of DRA gene products and differential amounts of DRB1 gene products. Thus, the incompletely inducible expression of DRB1 gene products was responsible for the limited accumulation of normally assembled molecules for cell surface expression and the lack of serological determination.

Dimerization↗
PubMed1996

Acceleration of thrombosis and hemolysis by fibrinolysis inhibiting factor and suppression by Ia antigen expressed on T cells in partially hepatectomized Lewis rats.

Partial hepatectomy (PH) of a left lateral lobe was performed on 45 Lewis rats 6.5-8.0 weeks old. Splenectomy, the injection of a fibrinolysis inhibiting (F1) factor (Gly-Pro-Arg-Pro) and both treatments were combined with the PH in 10, 11 and 9 rats, respectively. Among them, 4 males became weak with marked atrophic thymus before the 46th day after PH. All these males had massive pulmonary necrosis accompanied by platelet-rich emboli. Erythrocyte rosette formation was recognized in the mesenteric lymph nodes (MLN) of all 4 rats. The rosette erythrocytes reacted to anti-macrophage antibodies. FI factor-induced acute immune hemolysis occurred 5-9 days after PH in the 2 of the FI factor-injected and splenectomized males. Mildly to moderately atrophic thymuses were found in almost all the rats followed for 156-177 days after PH. T lymphocytes with cytoplasmic dense polysomes and desquamating endothelial cells with phagocytic erythrocytes were observed in the thymic electron micrograph of the FI factor-injected female. Positive D-D dimers were measured in the plasma of 7 rats. Increased peripheral reticulocytes (7.0 +/- 0.4%) were recognized in the males 156 days after single PH but not in the females. Ten of the 24 females and 3 of the 16 males showed an increase of peripheral Ia+ T cells to 20-30%. As well as acute pulmonary emboli, autoimmune hemolysis was induced more actively after PH in the males with CD5+ T cells that expressed the Ia antigen weakly.

Anemia, Hemolytic, Autoimmune↗
PubMed1996

Alpha 1 antitrypsin defective Lewis rats injected with heparin: comparison of the glomerular changes with those of Lewis rats produced anti BSA antibody.

Heparin effects were studied on Lewis rats with alpha 1 antitrypsin (AT) defect. Among 8 rats that were born at the same birth, three rats were shown to have mild defect of alpha 1 AT. Heparin was injected repeatedly into all the 8 rats. Interstitial pneumonia and localized periodic acid-Schiff (PAS) stain of hepatocytes were found in alpha 1 AT defective male. One of the three alpha 1 AT defective rats had about a half of normal alpha 1 AT level. Antithrombin (AT) III level was slightly low in the alpha 1 AT defective female with splenomegaly. Lung electron micrograph of the other alpha 1 AT defective female showed edematous changes of capillaries and alveolar basement membranes and also proliferated collagen fibers. In the lung of alpha 1 AT defective male, many thrombocytes adhered to alveolar degenerated smooth muscles that were recognized as Masson bodies. Extracted platelet-activating factor (PAF) in the plasma of the alpha 1 AT defective male was shown to trigger T lymphocyte chemotaxis. Five normal Lewis rats were immunized with bovine serum albumin (BSA). IgG1 antibody to BSA was produced in all the rats. The rats with high titers of IgG1 anti BSA antibody showed more strongly atrophic changes of glomerulus than those of the mild alpha 1 AT defective rats treated with heparin.

Animals↗
PubMed1993

Association of HLA-A24 with complete beta-cell destruction in IDDM.

A sensitive C-peptide immunoreactivity radioimmunoassay demonstrated the presence of subtle, but definite residual beta-cell function in patients with IDDM of long duration. Although HLA antigens are known to influence susceptibility to IDDM, their contribution to the extent of pancreatic beta-cell destruction has not yet been examined extensively. We studied the relationship between residual beta-cell function and HLA class I and class II antigens in 111 unrelated Japanese IDDM patients. Using the sensitive C-peptide immunoreactivity radioimmunoassay, the presence or absence of residual beta-cell function was evaluated by the C-peptide immunoreactivity response to a 100-g oral glucose load. DNA typing for HLA-DQA1 and HLA-DQB1 antigens was performed in addition to serological typing of HLA-A, HLA-B, HLA-C, and HLA-DR antigens. A C-peptide immunoreactivity response > 0.033 nM was regarded as an indication of the presence of residual beta-cell function, not the assay error. Surprisingly, 35 of 37 (94.6%) patients without residual beta-cell function had HLA-A24, whereas only 39 of 74 (52.7%) patients with residual beta-cell function had this antigen (corrected P = 9.795 x 10(-6). Any other HLA antigens, including the DR and DQ loci, showed no difference in the frequency with regard to residual beta-cell function. The duration of diabetes was similar between the groups with and without residual beta-cell function.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Intracellular localization of the HLA class II gene products in transfected mouse L cells.

To investigate the impaired cell surface expression of human major histocompatibility antigen (HLA) in transfected L cells, we examined their intracellular localization by immunocytochemistry. HLA class II molecules produced in transfected L cells were mainly detected in the intracellular vesicles and in the nuclear envelope as granular precipitates. The results suggest that the intracellular transport of the newly synthesized molecules in transfected L cells is impaired at some point along the pathway from the rough endoplasmic reticulum (RER) to the medial-, trans-Golgi apparatus.

Animals↗
PubMed1991

Increased serum IgG2b and IgM & IgG1 Fc receptors expressed on tissue mast cells in experimental GVHR and HVGR rat models.

Chronic graft-versus-host reaction (GVHR) due to male specific (H-Y) antigen was induced by the injection of syngeneic (DA x Lewis) F1 female cells into (DA x Lewis)F1 male rats. Chronic host-versus-graft reaction (HVGR) based on major histocompatibility complex (MHC) (RT1a) occurred when host Lewis (RT1(1)) rats were transplanted (DA x Lewis)F1 donor cells (RT1a & RT1I). Chronic GVHR and HVGR were activated at fixed periods. The first attacks of the GVHR and HVGR were recognized 50-80 days after cell transplantation, but the most intensive attacks of both responses were observed 120-175 days after cell transplantation. During the most intensive attacks, two rats died from either GVHR or HVGR. Rat immunoglobulin assays measured by radial immunodiffusion (RID) showed that serum IgG2b rose to 10.600-11.500 mg/ml in the rats that had the advanced GVHR or HVGR. The tissue mast cells derived from the loose lymphoid tissues of the medullary and subcapsular sinuses have proliferated in the mesenteric lymph nodes of the rats. IgM and IgG1 binding Fc receptors expressed on the mast cells were demonstrated indirectly using alkaline phosphatase conjugated ant-rat IgM and anti-rat IgG1.

Animals↗
PubMed1990

Major histocompatibility complex (MHC) protein analysis by optimised two-dimensional electrophoretic methods.

Human histocompatibility molecules HLA-Class I and Class II (DR, DQ, DP) were analysed using three two-dimensional protocols: nonequilibrium pH gradient electrophoresis (NEPHGE), isoelectric focusing-acidic gradient (IEF-AG) and isoelectric focusing-basic gradient (IEF-BG). The three methods differ in their carrier ampholyte combinations and electrophoretic conditions. They provide different pH gradients and therefore different electrofocusing profiles. The NEPHGE protocol was adequate for separating proteins across a broad range of pI mobilities, i.e. 4.4 pH units between the acidic and the basic end. In contrast, the IEF-AG and the IEF-BG protocols gave a separation power across a narrow pH range, 1.9 and 1.7 pH units respectively. Thus, whereas the NEPHGE protocol provides a tool for a global major histocompatibility complex (MHC) antigen profile analysis, the IEF-AG and -BG allows one to investigate subcomponents of the individual MHC chains. For example, NEPHGE analysis of the HLA Class I heavy chain revealed a single spot. However, IEF-BG revealed the presence of six equidistantly spaced spots spanning a short pH gradient with identical molecular weight. Similar improved resolution was seen for the HLA-DR, DQ, and DP molecules. The IEF acidic gradient was adequate for separating the alpha chain; the IEF basic gradient gave better resolution of the beta chains. This data provides a baseline set of conditions for both analytical and preparative MHC protein studies prior to amino acid sequencing.

Alleles↗
PubMed1990

Importance of DQB as an indicator in living-related kidney transplant.

Southern blot hybridization was performed in 16 pairs of living-related kidney transplant patients and donors, using DNA samples extracted from peripheral blood lymphocytes. The number of HLA-DNA-mismatched bands was used as an indicator for graft survival. The total number of DNA-mismatched bands seemed to be a valuable parameter. This was further analyzed and it was found that DQB in particular could be used to predict graft survival. Especially, usefulness of HLA-DNA typing was found in positive MLR, where good prognosis was strongly related to DQB matching. This method can therefore be applied in selecting a suitable living-related donor with the best chance of graft survival.

DNA↗
PubMed1989

Analysis of gene structure and antigen determinants of DR2 antigens using DR gene transfer into mouse L cells.

Three HLA class II DR beta genes and one DR alpha gene from the DR2 haplotype were cloned in cosmid vectors. The DR beta II gene might be a pseudogene lacking the first exon that encodes the leader peptide. The DR beta I and DR beta III genes were expressed, together with the DR alpha-chain, after transfection into mouse L cells. Restriction enzyme mapping of the DR beta genomic clones and reactivity of their products expressed on the L cell transfectant against mAb showed that the DR beta I and DR beta III genes encoded the nonpolymorphic and polymorphic DR beta chain, respectively. This arrangement is the reverse of that observed in other haplotypes, such as DR3, 4 and 6. The alignment of the HLA class II genes including the DR beta genes on the chromosome 6, however, was consistent with other haplotypes, e.g., centromere-DX beta-DX alpha-DV beta-DQ beta-DQ alpha-DR beta I-DR beta II- DR beta III-DR alpha-telomere. These results suggest that the susceptibility to mutations or gene conversions responsible for genetic polymorphisms depends on the gene itself and not on its location. Furthermore, absorption experiments of anti-DR2 allosera by the DR alpha/DR beta transfectants revealed that the so-called DR2 specificities were determined by multiple epitopes although both the DR beta I and DR beta III genes behaved similarly with DR2-specific antibodies.

Absorption↗