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N Tsuji

Publications and source records attributed to N Tsuji.

At least 55 records · Page 3Linked to original sources
PubMed1998

An ERp60-like protein from the filarial parasite Dirofilaria immitis has both transglutaminase and protein disulfide isomerase activity.

Transglutaminases (TGases; EC 2.3.2.13) are a family of enzymes that catalyze calcium-dependent covalent cross-linking of cellular proteins by establishing epsilon-(gamma-glutamyl)lysine isopeptide bonds. These covalent isopeptide bonds are of great physiological significance because they are highly resistant to proteolysis, denaturants, and reducing agents. Prior studies have demonstrated the presence of isopeptide bonds in the sheath and cuticle of filarial parasites, suggesting an important role for TGase-catalyzed reactions during the growth and development of filarial nematodes. Herein we report the identification and cloning of a cDNA encoding a TGase from the dog heartworm Dirofilaria immitis (DiTG). The DiTG expressed in Escherichia coli (recombinant DiTG) was able to catalyze calcium-dependent cross-linking reactions. The derived amino acid sequence of the DiTG cDNA (pDiTG) predicts a protein of 57.1 kDa and includes an N-terminal hydrophobic signal peptide. The pDiTG has no sequence similarity with any of the known TGases, but it has significant homology to protein disulfide isomerase (PDI) and, particularly, to the PDI-related endoplasmic reticulum protein ERp60, a PDI isoform found in the lumen of endoplasmic reticulum. As predicted from the amino acid sequence homology, recombinant DiTG catalyzed the isomerization of intramolecular disulfide/sulfhydryl bonds in denatured RNase in vitro as effectively as did mammalian PDI. Conversely, purified PDI from bovine liver could catalyze protein cross-linking reactions in a Ca(2+)-dependent manner. This report describes the dual catalytic activity of TGase and PDI in post- and/or cotranslational modification of newly synthesized proteins. These TGase-catalyzed posttranslational modifications may play a pivotal role in the synthesis of new cuticle during the growth and maturation of filarial parasites.

Amino Acid Sequence↗
PubMed1998

Myoepithelioma of the lung: report of two cases and review of the literature.

Myoepithelial tumors occur mainly in the salivary glands, the sweat glands or the breast, but uncommonly in the lung. Herein, we describe two cases of myoepithelioma of the lung. Both patients were 58-year-old men, in whom the tumors were located in the right-upper bronchus and in the left-upper bronchus, respectively, with endobronchial growth pattern. Surgery was performed, but metastasis occurred into the forearm and hip muscles in the former case, and into the liver in the latter. Histologically, the tumor in the former was a spindle-plasmacytoid type, and that in the latter was a plasmacytoid type in part with squamous differentiation. Based on histochemical, immunohistochemical and ultrastructural analyses, both were compatible with myoepithelioma. The clinicopathological uniqueness of this neoplasm is discussed, together with a review of reports of this disease in the literature.

Fatal Outcome↗
PubMed1998

DNA-binding properties of the overexpressed recombinant estrogen receptor alpha.

Estrogen receptor alpha was overexpressed in COS-7 cells by transformation of an expression vector with the full length open reading frame of the receptor alpha. The nuclear estradiol-receptor complex and the soluble receptor from the COS-7 cells were cross-linked with an estrogen response element (ERE), which was substituted with 5-bromo-2'-deoxyuridine (BrdUVRE), as the receptor dimers by UV irradiation. In gel retardation analysis, the specific bindings of both nuclear and soluble receptors to ERE were decreased with increasing of KCl concentration compared with 0.1 M KCl. The ionic interactions of both receptors with ERE are thought to be similar.

Animals↗
PubMed1997

Expression of Fas ligand in liver metastases of human colonic adenocarcinomas.

Fas ligand (FasL) plays a pivotal role in lymphocyte cytotoxicity and the maintenance of immunological homeostasis. Since FasL has been implicated in the existence of immunologically privileged body sites by inducing apoptosis of activated T lymphocytes, we investigated the expression of FasL in human colon cancers. We found that two out of seven primary tumors and all four hepatic metastatic tumors of surgically obtained colonic adenocarcinoma expressed FasL mRNA and protein, detected by reverse transcription-coupled PCR and by immunohistochemical staining, respectively. Expression of FasL was not detected in normal colonic epithelial cells. FasL mRNA was also expressed in some human colonic adenocarcinoma cell lines including SW480, SW1116, and LS180 cells. Cell-surface-associated FasL was detected in these human colon cancer cells by fluorescence immunocytochemical staining. In addition, the expressed FasL was demonstrated to be functional, since coculture experiments using FasL-expressing SW480 cells resulted in apoptosis of Jurkat T leukemia cells that are sensitive to Fas-mediated apoptosis, and this process was specifically inhibited by the neutralizing anti-human FasL antibody. Thus, our findings and other data suggest an alternative mechanism that enables tumors to evade immune destruction by inducing apoptosis in activated T lymphocytes. Furthermore, constitutive expression of FasL in hepatic metastatic tumors suggests that FasL may also be important in their colonization in the liver through induction of apoptosis in the surrounding Fas-expressing hepatocytes.

Adenocarcinoma↗
PubMed1997

Effects of TAK-029, a novel GPIIb/IIIa antagonist, on arterial thrombosis in guinea pigs, dogs and monkeys.

The antithrombotic and bleeding time (BT) prolonging effects of TAK-029, a novel GPIIb/IIIa antagonist, were examined in three arterial thrombosis models. In guinea pigs, TAK-029 at 30 micrograms/kg (i.v.) inhibited ADP-induced ex vivo platelet aggregation completely and prolonged BT to 4.5 times the control value 5 min after administration, and it prevented thrombotic occlusion in 2 out of 5 animals in a photochemically-induced basilar thrombosis model. TAK-029 at 100 micrograms/kg (i.v.) prolonged BT more than 9 times 5 min after administration, and it prevented thrombus formation for over 60 min. In dogs, TAK-029 at 30 micrograms/kg (i.v.) inhibited ADP-induced ex vivo platelet aggregation by 87% 5 min after administration, and it prevented thrombotic occlusion in injured and stenosed coronary arteries for 22 min without prolonging the BT. TAK-029 at 100 micrograms/ kg (i.v.) inhibited platelet aggregation completely and prolonged BT 3.6 times 5 min after administration, and it prevented thrombus formation for over 45 min. In monkeys, TAK-029 at 10 micrograms/kg (i.v.) inhibited ADP-induced ex vivo platelet aggregation by 84% and prolonged BT 4.6 times 5 min after the administration, and it prevented thrombotic occlusion in injured and stenosed carotid arteries for 24 min. TAK-029 at 30 micrograms/kg (i.v.) completely inhibited platelet aggregation and thrombus formation for over 60 min, and it prolonged BT more than 7.3 times 60 min after administration. In conclusion, TAK-029 exerted potent antithrombotic effects with BT prolongation in three different arterial thrombosis models. TAK-029 may be effective for the treatment of various arterial thrombotic diseases.

Animals↗
PubMed1997

Endogenous tumor necrosis factor as a predictor of doxorubicin sensitivity in leukemic patients.

We have previously reported that intracellular tumor necrosis factor (enTNF) is responsible for resistance, in established cell lines to doxorubicin (DOX), exogenous TNF, and heat stress by inducing manganous superoxide dismutase (MnSOD), thereby scavenging reactive oxygen free radicals. Leukemic cells from 19 patients (6 acute lymphoblastic leukemia, 13 acute myeloid leukemia) were examined for their sensitivity to DOX and TNF in relation to their enTNF expression and MnSOD activity. Sensitivity to DOX and the expression of enTNF or MnSOD activity were inversely correlated. In a case with acquired resistance to chemotherapy which included DOX, enTNF expression and MnSOD activity were increased. Furthermore, in 14 cases treated with a regimen including an anthracycline, 4 cases that failed to respond to chemotherapy showed relatively high amounts of enTNF expression. KG-1 (human acute myelogenous leukemia) cells transfected with a nonsecretory-type TNF expression vector (pTNF delta pro) showed resistance to DOX. A significant increase in MnSOD levels was also noted in the transfectants. TNF antisense cDNA was transfected into isolated leukemic cells from five patients. Sensitivity of the antisense transfectants to DOX was increased, approximately 1.4- to 2.5-fold. These results suggest that enTNF acts as a resistance factor against DOX in leukemia, and that enTNF may be useful as a predictor of DOX sensitivity in leukemia.

Acute Disease↗
PubMed1997

Induction of heat shock protein 72 synthesis by endogenous tumor necrosis factor via enhancement of the heat shock element-binding activity of heat shock factor 1.

Endogenous tumor necrosis factor (enTNF) acts as a resistance factor against cytotoxicity caused by heat by inducing manganous superoxide dismutase (MnSOD), thereby scavenging reactive oxygen free radicals. On the other hand, it is also well known that heat shock proteins (HSP) which are induced by heat stress behave as cytoprotective factor against this stress. However, the relationship of these two resistance factors is not elucidated yet. In the present study, we therefore proposed the possibility that enTNF enhances HSP72 expression. Heat-sensitive L-M (mouse tumorigenic fibroblast) cells, which normally do not express enTNF, were transfected with a nonsecretory-type human TNF-alpha expression vector to produce enTNF. Stable transfectants showed resistance to heat treatment and an increase of HSP72 expression. Conversely, when HeLa (human uterine cervical cancer) cells, which normally produce an appreciable amount of enTNF, were transfected with an antisense TNF-alpha mRNA expression vector to inhibit enTNF synthesis, their heat sensitivity was enhanced and HSP72 expression was reduced by half. Although enTNF caused no difference in the level of heat shock factor (HSF) 1 in these cells, enTNF expression correlated well with the binding activity of HSF-1 to a 32P-labeled synthetic oligonucleotide containing the human heat shock element (HSE). These results indicate that enTNF participates not only in intrinsic resistance against heat via induction of MnSOD but also via enhancement of the HSE-binding activity of HSF 1 followed by augmentation of HSP72 expression.

Animals↗
PubMed1997

New endoscopic treatment for chronic pancreatitis, using contrast media containing ulinastatin and prednisolone.

The preventive effects of contrast media containing ulinastatin (UST) and/or prednisolone (PDN) on potential complications associated with endoscopic retrograde cholangiopancreatography (ERCP) were studied in 111 patients. The incidence of abdominal pain and the elevation in the serum amylase level after ERCP were lower in the UST group than in the control group and abdominal pain and the elevated serum amylase level were almost completely suppressed in the PDN and UST/PDN groups. Based on these findings, a comparative study was conducted to evaluate the effectiveness of a combination of UST and PDN, given via the pancreatic duct, in alleviating pain symptoms in 57 patients with chronic pancreatitis and abdominal pain. The post-ERCP serum amylase level in some patients in the PDN and UST/PDN groups was lower than the pretreatment value. After ERCP, the abdominal pain that had been experienced before ERCP was relieved, and the value of the bentiromide-paraaminobenzoic acid (BT-PABA) test had improved. These results suggest that the use of contrast media containing PDN or UST/PDN in patients with chronic pancreatitis is extremely effective not only for preventing potential complications related to ERCP but also as a new diagnostic treatment method.

Abdominal Pain↗
PubMed1997

Expression of a 70-kDa heat-shock-related protein during transformation from free-living infective larvae to the parasitic stage in Strongyloides venezuelensis.

The in vitro transformation system of Strongyloides venezuelensis has been established which induces free-living infective larvae to transform into the parasitic stage by a temperature shift from 25 to 37 degrees C. Comparison of the profiles of proteins labeled with [35S]-methionine in infective larvae at 25 and 37 degrees C with marked morphological transformation revealed an increase in the 70-kDa protein, thus showing these proteins to be related to the family of heat-shock proteins. In addition, the new appearance of two complexes between 16-kDa and 22-kDa proteins was observed. The 70-kDa protein cross-reacted with monoclonal antibody against human heat-shock protein 70, which was constitutively expressed. These proteins, synthesized during the transformation of S. venezuelensis from the infective larval stage to the parasitic stage, might be crucial for biochemical events that regulate the infectivity of the parasite for the host.

Animals↗
PubMed1997

Localization of insulin receptor-related receptor in the rat kidney.

Insulin receptor-related receptor (IRR), a member of the insulin receptor family, is most abundantly expressed in the kidney. However, its endogenous ligand and physiological roles are still unknown. To elucidate the physiological role of IRR, an orphan receptor, in the kidney, we examined the localization of IRR mRNA and its immunoreactivity in the rat kidney by in situ hybridization and immunohistochemistry, respectively. IRR mRNA was found to be exclusively localized in the cortical collecting duct. The localization of IRR immunoreactivity was consistent with that of IRR mRNA. Furthermore, IRR immunoreactivity was found to be localized on the basolateral plasma membrane of the epithelial cells that were a minor cell subpopulation (20 to 30%) of the duct. The present findings indicated that IRR in the kidney was exclusively localized on the basolateral plasma membrane of type B intercalated cells of the cortical collecting duct.

Animals↗
PubMed1997

Immunohistochemical and ultrastructural analyses of in situ activation of hepatic stellate cells around Propionibacterium acnes-induced granulomas in the rat liver.

Stellate cells embrace the hepatic sinusoids as pericytes. To demonstrate their activation in juxta-sinusoidal location, we induced hepatic granulomatous inflammation, which did not accompany liver injury nor fibrosis, by administrating a low dose (10 mg/kg b.w.) of heat-killed Propionibacterium acnes into rats. Macrophages and lymphocytes migrated out of the sinusoid and made compact granulomas in the space of Disse. Stellate cells which faced on the granulomas were closely attached to the sinusoidal endothelial cells and extended projections into the spaces between the constituent mononuclear cells of granulomas. They did not migrate into granulomas nor displayed mitosis. Immunohistochemically, stellate cells around the granulomas expressed alpha-smooth muscle actin (alpha-SMA), whereas those in the non-granulomatous regions did not. Small deposits of type III collagen were found at the periphery of granulomas. Biochemical analysis showed an increased amount of alpha-SMA protein and type III collagen mRNA in the granuloma-bearing liver. Transforming growth factor-beta and platelet-derived growth factor were detected within the granulomas. The present study has revealed that stellate cells are activated in situ by extrasinusoidal macrophages in a paracrine manner without being detached from the sinusoidal wall.

Animals↗
PubMed1997

Discrimination of eight chicken Eimeria species using the two-step polymerase chain reaction.

A method was developed for the discrimination of 8 Eimeria species of chickens, i.e., E. acervulina, E. brunetti, E. mitis, E. maxima, E. necatrix, E. praecox, E. tenella, and E. hagani using the 2-step polymerase chain reaction (PCR). In the first PCR, the small subunit ribosomal RNA (srRNA) gene was amplified from the parasite genome using conserved sequences for the Apicomplexa srRNA gene as the primers. The srRNA gene amplified from the parasite genome was discriminated in the second step by random-amplified polymorphic DNA (RAPD) PCR using 10 arbitrary primers. Each arbitrary primer produced species-specific RAPD patterns that provided a simple method for species identification from the srRNA genes of the 8 Eimeria species. This method should be useful for discrimination of the parasite species for diagnosis or epidemiological surveys of chicken coccidiosis.

Animals↗
PubMed1996

Expression of insulin receptor-related receptor in the rat brain examined by in situ hybridization and immunohistochemistry.

Insulin receptor-related receptor (IRR) is a member of the insulin receptor family. However, its endogenous ligand and physiological roles are unknown. To elucidate the physiological roles of IRR, an orphan receptor, in the brain, we examined its expression at mRNA and protein levels in the brain by in situ hybridization and immunohistochemistry, respectively. The expression of IRR mRNA in the brain was highly restricted to the forebrain including the nucleus of the diagonal band, medial septal nucleus, ventral pallidum, accumbens nucleus and caudate putamen, and the brainstem including the prepositus hypoglossal nucleus, medial vestibular nucleus, gigantocell reticular nucleus, paragigantocellular nucleus and ventral cochlear nucleus. Most IRR mRNA-positive cells in the forebrain but not in the brainstem were cholinergic neurons. However, most IRR mRNA in the forebrain and brainstem was coexpressed with that of trkA, a high-affinity receptor for nerve growth factor. IRR-immunoreactive cell bodies were also detected in the forebrain and brainstem. The pattern of IRR immunoreactivity was similar to that of IRR mRNA. Its restricted pattern indicates that IRR plays unique roles in the brain, in contrast to insulin and insulin-like growth factor-I receptors, other members of the insulin receptor family, which are widely expressed in the brain.

Animals↗
PubMed1996

Endogenous tumor necrosis factor inhibits the cytotoxicity of exogenous tumor necrosis factor and adriamycin in pancreatic carcinoma cells.

Pancreatic carcinoma is one of the most devastating neoplasms with regard to its resistance to conventional therapy. In a previous report, we found that endogenous tumor necrosis factor (enTNF) exerts an intracellular protective effect against exogenous TNF- and Adriamycin (ADM)-induced cytotoxicity by scavenging oxygen free radicals (OFR) with induced manganous superoxide dismutase (MnSOD). We also know that glutathione S-transferase pi (GST-pi) and glutathione (GSH) also scavenge OFR. It remains unclear to what extent enTNF and MnSOD induced by enTNF regulate the sensitivity to ADM and exogenous TNF among different carcinoma cells. In this study, we examined the relationship between ADM and exogenous TNF sensitivity and en-TNF expression and MnSOD activity in four pancreatic carcinoma lines. We determined whether ADM and exogenous TNF sensitivity could be predicted by measuring enTNF expression and MnSOD activity in the carcinoma cells. The sensitivity to TNF and ADM varied with the cell lines, and TNF sensitivity correlated well with Adriamycin sensitivity. Moreover, enTNF expression and Mn-SOD activity correlated positively with resistance to ADM and exogenous TNF. When MIAPaCa-2 cells, which had the lowest enTNF expression and the highest sensitivity to exogenous TNF and ADM, were transfected with the nonsecretory-type human TNF gene (pTNF delta pro) to increase enTNF synthesis, their intracellular MnSOD activity and exogenous TNF and ADM resistance were increased. These findings suggest that MnSOD plays a critical role in scavenging OFR induced by ADM and exogenous TNF. enTNF is the most important factor that regulates the production of MnSOD. Therefore, it is plausible that inhibition of enTNF expression or MnSOD activity in pancreatic carcinoma would improve the efficacy of therapies for pancreatic carcinoma.

Doxorubicin↗
PubMed1996

Tumor necrosis factor and interferon-gamma augment anticolon antibody- dependent cellular cytotoxicity in ulcerative colitis.

The effect of tumor necrosis factor (TNF) and interferon (IFN)-gamma on antibody-dependent cellular cytotoxicity (ADCC) in patients with ulcerative colitis (UC) was investigated. ADCC activity was measured by the 51Cr release assay, using peripheral blood mononuclear cells of healthy subjects as effector cells and RPMI 4788 cells derived from human colon cancer as target cells. ADCC activity under sera from healty subjects remained low whether or not the effector cells were pretreated with TNF (100 U/ml, 16h). Under sera from UC patients, ADCC activity of 13.9%, compared to 9.6% when pretreatment was deleted. The effect of IFN pretreatment (100 U/ml, 16h) was also examined under sera from UC patients; in that experiment activity rose to 26.8%, in comparison to a 10.7% when IFN-gamma pretreatment was deleted. Finally, when the effector cells were pretreated with both TNF and IFN-gamma (100 U/ml of each, 16h) the ADCC activity under sera from UC patients was higher than when either TNF or IFN-gamma were used alone. These results suggest that TNF and IFN-gamma, by increasing ADCC activity in UC lesions, are involved in cell injury in the colonic epithelium. IFN-gamma appears to increase ADCC activity by increasing the number of high affinity monocyte Fc gamma RI receptors, while TNF increases ADCC activity by a different mechanism.

Adjuvants, Immunologic↗
PubMed1996

MR of xanthogranuloma of the choroid plexus.

We present a case of a xanthogranuloma of the lateral ventricle choroid plexus in association with focal areas of abnormal T2 signal in the tegmentum of the pons as well as within the middle cerebellar peduncles. The characteristic MR appearance of this rare entity is described along with a pathologic basis suggesting an association with posterior fossa lesions.

Adult↗
PubMed1995

Expression of insulin receptor-related receptor mRNA in the rat brain is highly restricted to forebrain cholinergic neurons.

Insulin receptor-related receptor (IRR) is a member of the insulin receptor family. However, its endogenous ligand and the physiological roles of IRR are unknown. To elucidate the physiological roles of IRR in the brain, we examined the expression of its mRNA in the rat brain by in situ hybridization. In contrast to the widespread expression of insulin receptor and insulin-like growth factor-1 receptor mRNAs in the brain, the expression of IRR mRNA was highly restricted to the forebrain cholinergic neurons. All the forebrain cholinergic neurons expressed IRR mRNA. The present findings indicate that IRR has a selective role in the brain for forebrain cholinergic function.

Animals↗