Biomedical subjects

T Nishihara

Publications and source records attributed to T Nishihara.

At least 55 records · Page 3Linked to original sources

PubMed2001

[A case of gastric cancer with multiple liver metastases that were completely responsive to hepatic arterial infusion chemotherapy].

A 70-year-old male was hospitalized with a diagnosis of gastric cancer. Multiple liver metastases were detected by CT scan and ultrasonography, but no other metastases were found. After distal gastrectomy with lymphadenectomy, an intra-arterial catheter was inserted and hepatic arterial infusion (HAI) chemotherapy was started with the following regimen: epirubicin, 40 mg (once in 4 weeks); MMC, 4 mg (once in 2 weeks); and 5-FU, 500 mg (once a week). Oral administration of 300 mg/day of tegafur-uracil (UFT) was given concurrently. The metastatic liver tumors were gradually reduced, and then disappeared. The patient has been free from recurrence after HAI. As gastric cancer tends to spread (e.g. peritoneal dissemination) more than colorectal cancer, the indication for HAI in cases of gastric cancer is limited. However, the present case suggests that it may be useful in achieving long-term survival for patients with metastases localized in the liver.

Adenocarcinoma↗

PubMed2000

Two nuclear localization signals are required for nuclear translocation of nuclear factor 1-A.

Nuclear factor 1 (NF1) proteins are encoded by at least four genes (NF1-A, B, C, X). Although DNA-binding and the transcription regulation domains of these proteins are well characterized, the nuclear localization signals (NLSs) are still unknown in all NF1s. We have identified two NLSs in NF1-A, and both are required for full translocation to the nucleus, although one of them itself has a partial translocation ability. These two NLSs are conserved in all four NF1s. Interestingly, three isoforms of NF1-A (NF1-A1, A2, A4) have two NLSs and translocate completely to the nucleus. In contrast, NF1-A3 lacks the second NLS and partially stays in the cytoplasm. Since NF1s construct homodimer and heterodimer, these findings indicate the differential regulations of the NF1 translocation.

Amino Acid Sequence↗

PubMed2000

Molecular cloning and functional characterization of a novel nuclear receptor similar to an embryonic benzoate receptor BXR.

Benzoate X receptor (BXR) is a member of the nuclear hormone receptor superfamily and is activated by alkyl esters of amino benzoic acids and expressed during early development stages. We report here a second BXR, which was cloned by screening Xenopus laevis embryonic cDNA libraries. This new BXR, termed BXRbeta, exhibits 97% identity in the DNA-binding domain and 79% identity in the ligand-binding domain in amino acid sequence to previously reported Xenopus BXR. The BXRbeta strongly binds as a heterodimer with retinoid X receptor (RXR) to direct repeats of an AGGTCA motif spaced 4 or 5 base pairs apart and activates transcription by addition of methyprednisolone and dexamethasone as well as amino- and hydroxybenzoates.

Amino Acid Sequence↗

PubMed2000

Bone morphogenetic protein-2 induces apoptosis in human myeloma cells with modulation of STAT3.

Bone morphogenetic proteins (BMPs), members of the transforming growth factor (TGF)-beta superfamily, are a group of related proteins that are capable of inducing the formation of cartilage and bone but are now regarded as multifunctional cytokines. We show in this report a novel function of BMPs in hematopoietic cells: BMP-2 induces apoptosis not only in human myeloma cell lines (U266, RPMI 8226, HS-Sultan, IM-9, OPM-2, and KMS-12 cells), but also in primary samples from patients with multiple myeloma. The mechanism of BMP-2-induced apoptosis was investigated with the use of U266 cells, which are dependent on the interleukin-6 autocrine loop. We showed that BMP-2 caused cell-cycle arrest in the G1 phase and the subsequent apoptosis of myeloma cells. BMP-2 up-regulated the expression of cyclin-dependent kinase inhibitors (p21(CIP1/WAF1) and p27(KIP1)) and caused hypophosphorylation of retinoblastoma (Rb) protein. In studies of apoptosis-associated proteins, BMP-2 was seen to down-regulate the expression of Bcl-x(L); however, BMP-2 had no effects on the expression of Bcl-2, Bax, or Bad. Therefore, BMP-2 induces apoptosis in various human myeloma cells by means of the down-regulation of Bcl-x(L) and by cell-cycle arrest through the up-regulation of p21(CIP1/WAF1) and p27(KIP1) and by the hypophosphorylation of Rb. Further analysis showed that the signal transducer and activator of transcription 3 (STAT3) was inactivated immediately after BMP-2 treatment. We conclude that BMP-2 would be useful as a novel therapeutic agent in the treatment of multiple myeloma both by means of its antitumor effect of inducing apoptotis and through its original bone-inducing activity, because bone lesions are frequently seen in myeloma patients.

Apoptosis↗

PubMed2000

Molecular evidence of complex tissue- and sex-specific mRNA expression of the rat alpha(2u)-globulin multigene family.

alpha(2u)-Globulin is well known to be a rat protein encoded by a highly homologous multigene family with more than twenty members. We report here the cloning and identification of major alpha(2u)-globulin mRNA species expressed in various tissues. Initially, eight individual clones (PGCL1-8) were obtained from a male preputial gland cDNA library. Data base analysis with BLAST demonstrated six mRNAs to be novel, all clones being characterized by highly conserved sequence motifs as lipocalins. All cDNAs contained an open reading frame of 543 nucleotides and encode 181 amino acid proteins showing 92.5-98.7% and 87.3-98.3% nucleic and amino acid identity, respectively. Denaturing gradient gel electrophoresis (DGGE) with sequence analysis showed that PGCL4 is a major member in the female mammary gland, and in the submaxillary and lachrymal glands of both sexes, while the counterpart in male liver and the coagulate glands was found to be PGCL1. Numbers of cDNA species including PGCL1 and PGCL4 were found in preputial glands, no sex-related difference being observed. These results directly demonstrate complex tissue- and sex-specific expression of alpha(2u)-globulins in terms of mRNA species, providing useful information for understanding regulation of the alpha(2u)-globulin multigene family.

Alpha-Globulins↗

PubMed2000

Dissociation of bone morphogenetic protein-mediated growth arrest and apoptosis of mouse B cells by HPV-16 E6/E7.

We have previously found that bone morphogenetic protein-2 (BMP-2), a member of the transforming growth factor-beta family, induces cell-cycle arrest in the G1 phase and apoptotic cell death of HS-72 mouse hybridoma cells. In this study, we show that BMP-2 did not alter expression of cyclin D, cyclin E, cyclin-dependent kinase 2 (CDK2), CDK4, p27KIP1, p16INK4a, or p15INK4b, but enhanced expression of p21(CIP1/WAF1). Accumulation of p21(CIP1/WAF1) resulted in increased binding of p21(CIP1/WAF1) to CDK4 and concomitantly caused a profound decrease in the in vitro retinoblastoma protein (Rb) kinase activity of CDK4. Furthermore, the ectopic expression of human papilloma virus type-16 E7, an inhibitor of p21(CIP1/WAF1) and Rb, reverted G1 arrest induced by BMP-2. Expression of E6/E7, without increasing the p53 level, blocked inhibition of Rb phosphorylation and G1 arrest, but did not attenuate cell death in BMP-treated HS-72 cells. Taken together, these results suggest that inhibition of Rb phosphorylation by p21(CIP1/WAF1) is responsible for BMP-2-mediated G1 arrest and that BMP-2-induction of apoptosis might be independent of Rb hypophosphorylation.

Animals↗

PubMed2000

Prediction for biodegradability of chemicals by an empirical flowchart.

A method for predicting aerobic biodegradability of chemicals was developed based on empirical knowledge. A flowchart was derived from rule of thumb relationships between the biodegradability and the number of the functional groups and substructures in a certain skeletal structure of chemicals. The flowchart classified chemicals into readily biodegradable, not readily biodegradable and not predictable. It was validated by using MITI data of 177 mono benzene derivatives and 168 acyclic compounds, resulting in correct prediction at 94% and 88% levels, respectively.

Aerobiosis↗

PubMed2000

Estrogenic activity of chemicals for dental and similar use in vitro.

The estrogenic activities of chemicals for dental and similar use were tested by a reporter gene assay (yeast two-hybrid system) and an estrogen/estrogen receptor (ER-alpha) competition binding assay (fluorescence polarization system). Among the 10 chemicals [bisphenol-A (BPA), bis-2-hydroxypropyl methacrylate (Bis-GMA), triethylene glycol dimethacrylate (TEGDMA), methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (HEMA), dibutyl phthalate (DBP), n-butyl benzyl phthalate (BBP), n-butyl phthalyl n-butyl glycolate (BPBG), di-2-ethylhexyl phthalate (DEHP), and di-2-ethylhexyl adipate (DOA)], which were diluted with DMSO to concentrations ranging from 5 x 10(-7) to 5 x 10(-3) M, and 17beta-estradiol (E2) as a positive control, BPA and BBP showed estrogenic activity in these two assays, while the remaining eight chemicals did not at the concentrations tested. Additional data, together with in vivo and epidemiological examinations, are required. Such investigations should also provide information on the validity of these methods for testing the estrogenic activity of chemicals.

Journal Article↗

PubMed2000

Arsenic trioxide (As2O3)-induced apoptosis and differentiation in retinoic acid-resistant acute promyelocytic leukemia model in hGM-CSF-producing transgenic SCID mice.

Recent clinical studies in China and USA showed that arsenic trioxide (As2O3) is an effective treatment of acute promyelocytic leukemia (APL) patients refractory to all-trans retinoic acid (RA). We here investigate the effects of As2O3 on RA-resistant APL in vivo and in vitro using our RA-resistant APL model system. As2O3 can induce inhibition of cellular growth of both RA-sensitive NB4 and RA-resistant UF-1 APL cells via induction of apoptosis in vitro. The expression of BCL-2 protein decreased in a dose- and time-dependent manner in NB4 cells. Interestingly, the levels of BCL-2 protein were not modulated by As2O3, but it did upregulate BAX protein in UF-1 cells. UF-1 cells (1x10(7)) were transplanted into hGM-CSF-producing transgenic SCID mice and successfully formed subcutaneous tumors. After 40 days of implantation, mice were treated with As2O3, all-trans RA and PBS for 21 days. In all-trans RA- and PBS-treated mice, tumors grew rapidly, with a 4.5-fold increase in volume at day 21 compared to the initial size. In marked contrast, tumor size was decreased to half of the initial size by the treatment of As2O3, which resulted in cells with the typical appearance of apoptosis. Interestingly, one of the As2O3-treated mice showed mature granulocytes in the diminished tumor, suggesting that As2O3 had dual effects on RA-resistant APL cells in vivo: both inducing apoptosis and differentiation of the leukemic cells. We conclude that our RA-resistant APL model will be useful for evaluating novel therapeutic approaches to patients with RA-resistant APL, and for further investigation of the metabolism of As2O3 in vivo.

Animals↗

PubMed2000

Biodegradation of didecyldimethylammonium chloride by Pseudomonas fluorescens TN4 isolated from activated sludge.

Bacteria that degrade didecyldimethylammonium chloride (DDAC) were isolated from activated sludge from a municipal sewage treatment plant by enrichment culture with DDAC as a sole carbon source. One of the isolates, Pseudomonas fluorescens TN4, degraded DDAC to produce decyldimethylamine and subsequently, dimethylamine, as the intermediates. The TN4 strain also assimilated the other quaternary ammonium compounds (QACs), alkyltrimethyl- and alkylbenzyldimethyl-ammonium salts, but not alkylpyridinium salts. TN4 was highly resistant to these QACs and degraded them by an N-dealkylation process. These data mean that there are some QAC-resistant and QAC-degrading bacteria such as TN4 in the environment.

Biodegradation, Environmental↗

PubMed2000

Antibody-dependent cytotoxicity mediated by chimeric monoclonal antibody Nd2 and experimental immunotherapy for pancreatic cancer.

In a previous study, mouse monoclonal antibody (MoAb) Nd2 (m-Nd2, mouse IgG1) labeled with (131)I exhibited efficacy in in vivo radioimmunotherapy against pancreatic cancer. In this study we prepared mouse / human chimeric antibody Nd2 (c-Nd2, human IgG1) for clinical use and examined whether c-Nd2 induced antibody-dependent cell-mediated cytotoxicity (ADCC). Cytotoxicity to pancreatic cancer (PC) cell lines, including Nd2 antigen-positive (SW1990, RWP-1, Capan-1) and Nd2 antigen-negative (Panc-1, MiaPaca-2, Capan-2) lines, was evaluated by mixed human leukocyte and tumor cell culture (MLTC) at an effector cell to target cell (E / T) ratio of 50 with or without Nd2. Cytotoxicities to SW1990 with no antibody, m-Nd2 and c-Nd2 (1 microg / ml) were 26.7%, 38.0% and 55%, respectively; to RWP-1, 28%, 41% and 70%; to Capan-1, 26%, 30% and 52%; to Panc-1, 24%, 28% and 30%; to MiaPaca-2, 18%, 20% and 27% and to Capan-2, 29. 7%, 35.0% and 40.6%. Cytotoxic capacity during MLTC with c-Nd2 was significantly higher than during MLTC with m-Nd2 or with no antibody. These findings indicated that cytotoxicity to Nd2-positive PC cells during MLTC is induced by ADCC. Intraperitoneal injection of c-Nd2 inhibited the tumor growth of SW1990 xenografted subcutaneously in nude mice and prolonged the survival of nude mice in which SW1990 tumor was transplanted orthotopically at the tail of the pancreas. These findings suggested that, because of its ability to induce ADCC, c-Nd2 may be clinically useful for the immunotherapeutic treatment of pancreatic cancer.

Animals↗

PubMed2000

Gene expression of CCAAT/enhancer-binding protein delta mediated by autoregulation is repressed by related gene family proteins.

CCAAT/enhancer-binding protein delta (C/EBPdelta) transcription factor is rapidly induced at an early stage of acute phase response. We previously reported that this induction was mainly mediated by acute phase response factor/signal transducers and activators of transcription 3 (APRF/STAT3). Furthermore, the high expression level of C/EBPdelta is maintained by autoregulation mechanisms through the C/EBPdelta binding sites located downstream of C/EBPdelta gene. Thereafter, the expression of C/EBPdelta gene decreases rapidly to the basal level. However, these mechanisms are still unknown. According to both transfection and DNA binding analyses, liver-enriched inhibitory protein (LIP), the shorter form of C/EBPbeta and C/EBP-homologous protein 10 (CHOP10), were found to inhibit C/EBPdelta gene expression. DNA binding analysis has further indicated that both LIP and CHOP10 form heterodimers with C/EBPdelta, and inhibit the binding of C/EBPdelta homodimer to the C/EBPdelta binding sites located downstream of C/EBPdelta gene. Taken together, these findings indicated that the maintained expression of C/EBPdelta gene by autoregulation was inhibited and decreased to the basal level as a result of the competition of other C/EBP family proteins. Thus, C/EBPdelta gene expression is mediated by the gene regulation circuit through the downstream C/EBPdelta binding sites.

Animals↗

PubMed2000

Cyclooxygenase-2-dependent prostaglandin production by peripheral blood monocytes stimulated with lipopolysaccharides isolated from periodontopathogenic bacteria.

BACKGROUND: Prostaglandin E2 (PGE2) plays important roles in the pathogenesis of periodontal disease. Recent studies have revealed the existence of 2 isozymes of cyclooxygenase (COX), called COX-1 and COX-2. The purpose of the present study was to investigate the contribution of COX-1 and COX-2 to PGE2 production by human peripheral blood monocytes that are stimulated with lipopolysaccharides (LPS) from periodontopathogenic bacteria. METHODS: LPS were isolated from Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans) and Porphyromonas gingivalis (P. gingivalis) by the phenol-water method. Peripheral blood monocytes were stimulated with LPS for the indicated periods, and the levels of PGE2 or interleukin (IL)-1 beta in the culture media were measured by enzyme-linked immunosorbent assay. Expression of COX-1 and -2 proteins was studied by immunocytochemical staining, and COX-2 mRNA expression was examined by Northern blot analysis. RESULTS: Peripheral blood monocytes stimulated with A. actinomycetemcomitans- or P. gingivalis-LPS produced PGE2 in a time- and dose-dependent manner. Indomethacin, a non-selective COX-1/COX-2 inhibitor, and NS-398, a specific COX-2 inhibitor, completely inhibited PGE2 production. Immunocytochemical staining of COX-1 and COX-2 proteins showed that expression of COX-2 protein was increased in monocytes that were stimulated with A. actinomycetemcomitans- or P. gingivalis-LPS, compared with that in unstimulated monocytes, whereas expression of COX-1 protein was not altered. Northern blot analysis showed that monocytes stimulated with A. actinomycetemcomitans- or P. gingivalis-LPS expressed COX-2 mRNA, while COX-2 mRNA was not detectable in unstimulated cells. Treatment of A. actinomycetemcomitans-LPS-stimulated monocytes with NS-398 induced a significant increase of IL-1 beta production to the same extent as treatment with indomethacin. CONCLUSIONS: These results suggest that COX-2 is induced in monocytes stimulated with LPS derived from A. actinomycetemcomitans and P. gingivalis and that the COX-2 is primarily responsible for PGE2 production. COX-2 may be pivotal in PGE2 production in periodontal lesions and may be involved in inflammatory responses.

Aggregatibacter actinomycetemcomitans↗

PubMed2000

Benign aqueductal cyst causing bilateral internuclear ophthalmoplegia after external ventricular drainage. Case report.

The introduction of magnetic resonance (MR) imaging to the field of neuroimaging has allowed detection of various lesions that cause aqueductal stenosis. The authors report the case of a 3-year-old boy in whom a benign ventricular cyst developed in the aqueduct. The patient became drowsy after having complained of headache and vomiting; MR imaging revealed mild triventricular dilation and a normal-sized fourth ventricle. Repeated MR imaging performed 1 week later revealed an aqueductal cyst that had markedly enlarged during the intervening period. An external ventricular drainage system was installed, but recovery of consciousness in the child was unsatisfactory and a new bilateral internuclear ophthalmoplegia developed. Fenestration of the cyst wall and placement of a ventriculocisternostomy in the third ventricle were performed simultaneously by using a flexible neuroendoscope. By 2 weeks postsurgery, the patient's neurological symptoms had completely resolved. This case illustrates that simple rerouting of ventricular cerebrospinal fluid (CSF) can aggravate the symptoms of this rare lesion by causing severe compression of periaqueductal structures by a cyst that maintains a high intracystic pressure. Endoscopic surgery was an excellent choice of treatment to achieve both cyst fenestration and normalization of intracranial CSF pressure by creating a ventriculocisternostomy.

Cerebral Aqueduct↗

PubMed2000

A transparent sheath for endoscopic surgery and its application in surgical evacuation of spontaneous intracerebral hematomas. Technical note.

The authors advocate the use of a transparent sheath for guiding an endoscope, a simple and unique tool for endoscopic surgery, and describe preliminary results of its application in the evacuation of hypertensive intracerebral hematomas. This sheath is a 10-cm-long tube made of clear acrylic plastic, which greatly improves visualization of the surgical field through a 2.7-mm nonangled endoscope inserted within. Between April 1997 and December 1998, the authors performed endoscopic evacuation of intracerebral hematomas by using this sheath inserted into the patients' heads through a burr hole. In nine consecutive cases in which the hematoma was larger than 40 ml in volume, nearly complete evacuation (86-100%) of the lesion was achieved without complication. Excellent visualization of the border between the brain parenchyma and the hematoma facilitated accurate intraoperative orientation, and also allowed easy identification of the bleeding point. Thus, this combination of sheath and endoscope achieves both minimal invasiveness and the maximum extent of hematoma removal with secure hemostasis. This tool will reduce the inherent disadvantage of endoscopic procedures and may expand their application in other areas of neurosurgical management.

Aged↗

PubMed1999

Expression, DNA-binding specificity and transcriptional regulation of nuclear factor 1 family proteins from rat.

Nuclear factor 1 (NF1) family proteins, which are encoded by four different genes (NF1-A, NF1-B, NF1-C and NF1-X), bind to the palindromic sequence and regulate the expression of many viral and cellular genes. We have previously purified NF1-A and NF1-B from rat liver as factors that bind to the silencer in the glutathione transferase P gene, and have also reported the repression domain of NF1-A. In the present study we cloned five cDNA species (NF1-B1, NF1-B2, NF1-B3, NF1-C2 and NF1-X1) and compared their expression profiles and the affinity and specificity of the DNA binding of these NF1 family members. By Northern blot analysis, we found that the expression profiles of the NF1s are indistinguishable in the various tissues of the rat. The DNA-binding affinities of NF1-A and NF1-X are higher than those of NF1-B and NF1-C, whereas all four NF1 proteins showed the same DNA-binding specificity. Transfection analyses revealed that the function of NF1-B on the transcriptional regulation differed between NF1-B isoforms and was affected by the factor(s) that bind to the promoter regions. In addition, we identified the transcriptional regulatory domain of NF1-B, which is enriched with proline and serine residues.

Amino Acid Sequence↗

PubMed1999

Osteoclast differentiation factor acts as a multifunctional regulator in murine osteoclast differentiation and function.

Osteoclast differentiation factor (ODF), a novel member of the TNF ligand family, is expressed as a membrane-associated protein by osteoblasts/stromal cells. The soluble form of ODF (sODF) induces the differentiation of osteoclast precursors into osteoclasts in the presence of M-CSF. Here, the effects of sODF on the survival, multinucleation, and pit-forming activity of murine osteoclasts were examined in comparison with those of M-CSF and IL-1. Osteoclast-like cells (OCLs) formed in cocultures of murine osteoblasts and bone marrow cells expressed mRNA of RANK (receptor activator of NF-kappaB), a receptor of ODF. The survival of OCLs was enhanced by the addition of each of sODF, M-CSF, and IL-1. sODF, as well as IL-1, activated NF-kappaB and c-Jun N-terminal protein kinase (JNK) in OCLs. Like M-CSF and IL-1, sODF stimulated the survival and multinucleation of prefusion osteoclasts (pOCs) isolated from the coculture. When pOCs were cultured on dentine slices, resorption pits were formed on the slices in the presence of either sODF or IL-1 but not in that of M-CSF. A soluble form of RANK as well as osteoprotegerin/osteoclastogenesis inhibitory factor, a decoy receptor of ODF, blocked OCL formation and prevented the survival, multinucleation, and pit-forming activity of pOCs induced by sODF. These results suggest that ODF regulates not only osteoclast differentiation but also osteoclast function in mice through the receptor RANK.

Acid Phosphatase↗

PubMed1999

Inhibitory effect of lipopolysaccharide on apoptotic cell death in macrophages infected with Actinobacillus actinomycetemcomitans.

We have reported that the macrophage-like cell line J774.1, when infected with the periodontopathic bacterium Actinobacillus actinomycetemcomitans, undergoes apoptosis. In this study, we examined whether stimulation of J774.1 cells with lipopolysaccharide (LPS) before the infection affects the subsequent apoptosis. Cytotoxicity on the LPS-stimulated cells was about half of the unstimulated control cells. DNA fragmentation in the LPS-stimulated cells was also significantly lower than in the control cells, whereas it was increased to a level similar to that of the control cells by addition of a nitric oxide (NO) inhibitor. In addition, significantly smaller numbers of live A. actinomycetemcomitans were recovered from the LPS-stimulated macrophages at 8 h after the infection as compared with the control cells. These findings suggest that the inhibitory effect of LPS on apoptosis results from an enhanced NO-mediated bactericidal activity.

Aggregatibacter actinomycetemcomitans↗