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S Nishimura

Publications and source records attributed to S Nishimura.

At least 55 records · Page 3Linked to original sources
PubMed2001

Prevention of hepatitis C virus infection in a chimpanzee by vaccination and epitope mapping of antiserum directed against hypervariable region 1.

We previously reported on a chimpanzee immunized with both putative envelope glycoproteins (E1 and E2) of hepatitis C virus (HCV), strain HCV-N2, and synthetic peptides of hypervariable region 1 (HVR1) of a different isolate, HCV-#6. The chimpanzee showed complete protection against HCV-#6 infection only when the titer of anti-HVR1 increased, suggesting that an immune response to the HVR1 is more essential in protecting a chimpanzee from HCV infection than an immune response to E1 and E2. In this study, we immunized this chimpanzee with only synthetic HVR1 peptides after anti-E1 and anti-E2 antibody levels dropped and then rechallenged with 10 infectious chimpanzee doses of HCV. The immunized animal was protected, and neutralization of HCV with the antiserum from the protected animal was achieved by inoculating another chimpanzee with HCV preneutralized by this antiserum mixture. Epitope analysis of HVR1 by Pin-ELISA using this antiserum seemed to demonstrate that the antibody response was directed mainly against the C terminus of HVR1. Moreover, our results showed that, if a part of the sequences was conserved, a broad cross-reactivity of the antiserum could be observed, even if amino-acid sequences in this epitope were substituted for those of other HCV strains.

Journal Article↗
PubMed2001

Heterobifunctional ligands: practical chemoenzymatic synthesis of a cell adhesive glycopeptide that interacts with both selectins and integrins.

An efficient and practical synthesis of cell adhesive glycopeptides exhibiting unique properties as a novel type of modulator of cellular recognition is described. A nonnatural glycopeptide 1 composed of sialyl Lewis x and Lys-Gly-Arg-Gly-Asp-Ser that interacts with both selectins and integrins has been systematically synthesized by combined chemical and enzymatic strategy. It is suggested that glycopeptide 1 showed much higher affinity with P-selectin (K(a) = 6.6 x 10(7) M(-1)) and E-selectin (K(a) = 4.5 x 10(5) M(-1)) than sialyl Lewis x. This compound also inhibited a specific interaction between human integrin beta(1) and its monoclonal antibody more effectively than the tetrapeptide Arg-Gly-Asp-Ser. Interestingly, it was demonstrated by surface plasmon resonance analysis that this heterobifunctional glycopeptide exhibited a capacity to form stable complexes with P-selectin and integrin beta(1) concurrently. It is also suggested that this activity can be used for the inhibition of integrin-mediated adhesion of activated helper T cells onto collagen-coated plates as a cell migration model. These results indicate that the chemoenzymatic hybridization strategy of different biological functions of carbohydrates and peptides is a new concept for designing potent glycoconjugates as antiinflammatory and anticancer metastasis reagents.

Animals↗
PubMed2001

Safety evaluation of phosphodiesterase produced from Penicillium citrinum: summary of toxicological data.

The toxicity of Enzyme RP-1, an enzyme preparation used to hydrolyze yeast RNA to produce flavor enhancers for use in the food industry, was evaluated in a series of studies. A 5-week dietary toxicity study in Wistar rats was conducted in which animals received Enzyme RP-1 in feed at concentrations of 0, 500, 2000, or 8000 mg/kg body wt/day. A 13-week dietary toxicity study in Sprague-Dawley rats was conducted in which animals received RP-1 concentrate at 0, 0.125, 0.5, or 2% in their diets. At the highest dose levels in both studies, submandibular glands in the oral cavity were enlarged, an effect attributed to protease activity of the enzyme preparation. The no-observed-effect level in rats in the 13-week study was 0.5%, equivalent to 317 mg/kg body wt/day for males and 346 mg/kg body wt/day for females. Based on estimated dietary exposure to the enzyme preparation, the margin of exposure is estimated to be greater than 38,000. Lack of genotoxic potential was demonstrated by an in vitro reverse mutation assay in Salmonella typhimurium strains TA98, TA100, TA1535, and TA1537 and in Escherichia coli strain WP2uvr and by an in vitro chromosome aberration test in CHL/IU cells derived from fibroblasts from the lungs of Chinese hamsters. Finally, the particular strain of Penicillium citrinum, the fungal strain used to prepare Enzyme RP-1, was shown to have low pathogenicity upon a single injection into the tail vein of rats of viable spores at doses up to 2.8x10(5) colony-forming units per animal. The results of these studies demonstrate that the enzyme preparation may be considered safe to workers and consumers when employed in the production of flavor enhancers from yeast.

Administration, Oral↗
PubMed2001

A repeated 28-day oral dose toxicity study of methoxychlor in rats, based on the 'enhanced OECD test guideline 407' for screening endocrine-disrupting chemicals.

In association with the international validation project to establish an OECD Enhanced Test Guideline 407, we performed a 28-day repeated-dose toxicity study of methoxychlor, a chlorinated hydrocarbon pesticide with pro-estrogenic and anti-androgenic activities. Attention was paid to the sensitivity of certain additional parameters for detecting endocrine related effects of endocrine disrupting chemicals based on the existing TG 407. Seven-week-old Crj:CD(SD)IGS rats were allocated to one of four groups, each consisting often males and ten females, and methoxychlor was administered once daily by gavage at doses of 0 (control), 20, 100 or 500 mg/kg body weight per day. Male rats were killed on the day after the 28th administration. Female rats were killed on the day of the diestrus stage during 4 days after the 28th administration. Male rats receiving methoxychlor showed mainly atrophy of mammary acinus in the 20 mg/ kg and higher groups, together with decreases in prostate and seminal vesicle weights, and atrophy of epididymis, prostate, seminal vesicle and coagulating gland in the 100 and 500 mg/kg groups. In addition, decrease in serum testosterone level, increase in follicle-stimulating hormone level, decrease in testis and epididymis weights, atrophy of semiferous tubules and Leydig cells, decrease in the number of sperm in the caudal epididymis and their motility were observed in the 500 mg/kg group. Female rats receiving methoxychlor showed mainly abnormal estrous cycles, decrease in serum luteinizing hormone level, decrease in ovary weight, proliferation of mammary acinus, atrophy of ovary due to decrease in follicles and corpus luteum in histopathology, hypertrophy of endometrial epithelium of uterus and vagina epithelium in the 100 and 500 mg/kg groups. Among the parameters tested in the present experimental system, effects of methoxychlor on endocrine-related organs were detected with regard to serum hormone, organ weights, histopathological examination in both sexes, estrus cycle in females and sperm examination in males. Based on these results, a no-observed-adverse-effect level (NOAEL) in the present study was estimated to be below 20 mg/kg per day. In particular, the adverse effects were effectively detected in organ weights of accessory sex organs and histopathological examination.

Administration, Oral↗
PubMed2001

An alternative therapeutic procedure for sinonasal undifferentiated carcinoma.

We describe two cases of sinonasal undifferentiated carcinoma, a rare and highly aggressive neoplasm of the paranasal sinuses. Case 1 had first been diagnosed as esthesioneuroblastoma, and intra-arterial and systemic chemotherapy and radiotherapy were performed. The tumor became smaller but did not disappear, and the patient died 2 months later. Case 2 received systemic chemotherapy and chemoradiotherapy, with daily venous administration of cisplatin during radiotherapy. The tumor became much smaller but also remained, and the patient died a month later. Although the therapy failed, chemoradiotherapy has some possibility of controlling the disease.

Adolescent↗
PubMed2001

Mammalian Ogg1/Mmh gene plays a major role in repair of the 8-hydroxyguanine lesion in DNA.

8-Hydroxyguanine (7,8-dihydro-8-oxoguanine, abbreviated as 8-OH-G or 8-oxoG) is the site of a frequent mutagenic DNA lesion produced by oxidative damage. MutM of E. coli and OGG1 of Saccharomyces cerevisiae are known to possess 8-OH-G glycosylase activity and apurinic (AP) site lyase activity to repair 8-OH-G lesions. Recently, cDNA clones of four isoforms (types 1a, 1b, 1c, and type 2) of human OGG1 homologs (hMMH) were isolated. However, it is unknown whether expression of endogenous hMMH proteins actually occurs in mammalian cells. We have chosen two approaches to clarify this issue. First, using hMMH type 1a-specific antibody and cells overexpressing tag-fused hMMH type 1a, we found that hMMH type 1a protein is in fact expressed in many types of human cells, showing that endogenous hMMH type 1a protein has 8-OH-G glycosylase/AP lyase activity. Furthermore, we have shown that upon antibody-mediated depletion of hMMH type 1a protein in a whole-cell extract, most of the AP lyase activity is lost, indicating that hMMH type 1a protein is a major enzyme for repair of 8-OH-G lesion in human cells. In our second approach we have generated a mouse line carrying a mutant Mmh allele by targeted gene disruption. Mmh homozygous mutant mice were found to be physically normal in appearance, but to have lost the nicking activity for substrate DNA containing 8-OH-G in liver extracts. In addition, the amount of endogenous 8-OH-G in liver DNA of the homozygous mutant mice at 8 weeks of age was 3-fold higher compared with wild-type or heterozygous mice. A further increase of 8-OH-G up to 7-fold was observed in 14-week-old animals. These results indicate that exposure of DNA to internal oxidative species constantly produces the mutagenic DNA adduct 8-OH-G in mice, and that Mmh plays an essential role in the repair of this type of oxidative DNA damage.

Animals↗
PubMed2001

Combinatorial syntheses of sugar derivatives.

There has been an exponential growth in interest of the functional roles of carbohydrates and cell surface glycoconjugates in the past 10 years. The importance of glycoconjugates as mediators of biosignals has stimulated investigation into simple and versatile methods for their synthesis. The synthesis of carbohydrates and glycoconjugates by combinatorial chemistry has gained considerable interest.

Carbohydrate Conformation↗
PubMed2001

Fibrous tumor of the breast in a postmenopausal woman receiving estrogen.

Fibrous tumor of the breast is a rare, benign stromal proliferation with atrophy of the epithelial component. Almost all patients who develop fibrous tumors are premenopausal. An unusual example of fibrous tumor of the breast is reported in a 62-year-old postmenopausal woman. The mass, first noted 1 year previously, progressively enlarged over the year. The patient noted a history of taking exogenous estrogens for 10 years. Intense estrogen administration during the year of enlargement may be associated with accelerated growth of the tumor. In addition, positive nuclear staining for estrogen receptor antibodies in stromal cells was demonstrated by immunohistochemical methods.

Estrogen Replacement Therapy↗
PubMed2001

Comparative pharmacokinetics of oral 6-mercaptopurine and intravenous 6-mercaptopurine riboside in children.

BACKGROUND: The poor absorption of orally administered 6-mercaptopurine (6MP) causes a wide variation in its cytotoxic efficacy. An i.v. dosage form would eliminate this problem. Our objective was to compare the pharmacokinetics of 6MP administered orally with those of an i.v. dosage form 6-mercaptopurine riboside (6MPR), in children with acute lymphoblastic leukemia or malignant lymphoma. METHODS: A total of 10 children were treated with oral 6MP, 50 mg/m(2) per day, while five children were treated with 6MPR, 50 mg/m(2) per day, administered by rapid i.v. injection. The plasma concentrations of 6MP and of 6MPR were measured on day 0, while the concentrations of 6-thioguanine nucleotides (6TGN) in red blood cells (RBC) were measured on day 2. The area under the plasma concentration-time curve (AUC1-5) was calculated from 1 to 5 h after drug administration. RESULTS: With the intravenously administered 6MPR, the AUC1-5 ranged from 124 to 186 (1.5-fold range, median 145) microM min; only two samples were obtained for the RBC concentration of 6TGN, and were 121 and 273 pmol per 25 mg hemoglobin. With the orally administered 6MP, the AUC1-5 ranged from 23 to 65 microM min (2.8-fold range, median 56); the RBC concentration of 6TGN ranged from 18 to 152 pmol per 25 mg hemoglobin (median 75). CONCLUSION: The i.v. administration of 6MPR showed less interindividual variation in the AUC1-5 coupled with a higher RBC level of 6TGN as compared with those by oral 6MP. We conclude that the i.v. administration of 6MPR achieves stable blood levels of active drug in children undergoing cancer chemotherapy.

Administration, Oral↗
PubMed2001

Scanning electron microscopic observation of the architecture of collagen fibres in chicken M. iliotibialis lateralis.

1. The collagen architecture of M. iliotibialis lateralis in chicken was observed under the scanning electron microscope after muscle maceration in NaOH. 2. Immunohistochemical methods showed Type I and III collagens to be distributed over both perimysium and endomysium. 3. Thick perimysium around secondary myofibre fasciculi was composed of many large longitudinal collagen bundles and a few small circumferential bundles. In contrast, thin perimysium around primary myofibre fasciculi showed mainly circumferential bundles. 4. Endomysium had a honeycomb-like structure and consisted of a fine collagen mesh, its main fibre striation being circumferential. 5. It is suggested that functional demand differs between thick perimysium and thin endomysium.

Animals↗
PubMed2001

Garlic supplementation increases testicular testosterone and decreases plasma corticosterone in rats fed a high protein diet.

The effects of garlic supplementation on protein metabolism were investigated by measuring testis testosterone and plasma corticosterone in rats fed diets with different protein levels. In Experiment 1, rats were fed experimental diets with different protein levels (40, 25 or 10 g/100 g casein) with or without 0.8 g/100 g garlic powder. After 28 d of feeding, testosterone contents in the testis were significantly higher and plasma corticosterone concentrations were significantly lower in rats fed 40 and 25% casein diets with garlic powder than in those fed the same diets without garlic powder. Urinary excretion of 17-ketosteroid (an index of testosterone), nitrogen balance and hepatic arginase activity were significantly higher in rats fed the 40% casein diet with garlic powder than in the 40% casein controls. In Experiment 2, the effect of diallyldisulfide (a major volatile sulfur-containing compound in garlic) on the secretion of luteinizing hormone (LH) from the pituitary gland, which regulates testosterone production in the testis, was investigated in anesthetized rats. Plasma LH concentration increased dose dependently after administration of diallyldisulfide (P < 0.01, r = 0.558). These results suggest that dietary supplementation with 0.8 g/100 g garlic alters hormones associated with protein anabolism by increasing testicular testosterone and decreasing plasma corticosterone in rats fed a high protein diet.

17-Ketosteroids↗
PubMed2001

The promoter of mouse transcription repressor bach1 is regulated by Sp1 and trans-activated by Bach1.

The Maf recognition element (MARE) is regulated by both activators and repressors. Bach1 and Bach2 repress MARE-dependent transcription by forming heterodimers with Maf-related oncoproteins. In order to gain an understanding of the regulation of bach1 gene expression, we analyzed the structure of the mouse bach1 gene. Comparison of the exon-intron structure of the bach1 gene with those of other NF-E2-related genes indicated that bach1 and bach2 constitute an evolutionarily distinct subfamily among bZip factors. The bach1 promoter region contains two GC boxes that are important for its basal activity and are bound by Sp1 in K562 cell extracts. In addition, we found an evolutionarily conserved MARE-like element located downstream of the transcription initiation site. Deletion of this element resulted in a higher promoter activity in K562 cells. Bach1 trans-activated its own promoter depending on the presence of the MARE-like element in co-transfection assays. However, Bach1 did not bind to the MARE-like element in electrophoretic mobility shift assays (EMSA). These results suggest that Bach1 activates its own promoter indirectly by inhibiting the putative repressor. Such a positive feedback regulation by the repressor Bach1 may play an important role in maintaining the expression of Bach1 while consolidating repression of other genes with MARE.

Animals↗
PubMed2001

Intraarterial infusion chemotherapy and radiotherapy with or without surgery for patients with locally advanced or recurrent breast cancer.

We analyzed response, side effects, and local control rates of a multimodal treatment consisting of intraarterial infusion chemotherapy (IAIC) and radiotherapy with or without surgery for patients with locally advanced or recurred breast cancer. Thirty-three patients, clinically diagnosed as stage IIB in 1, IIIA in 2, IIIB in 12, IV in 18, were treated from 1991 to 1998. Twenty-five were primary and eight were recurrent cases after surgery. IAIC started as initial treatment up to three times maximum. In most cases, doxorubicin 50 mg, cisplatin 50 mg, and mitomycin 10 mg were infused in the subclavian and/or internal mammary artery. After IAIC, patients in primary cases underwent radical mastectomy or breast conservation surgery, after radiotherapy at a total dose of 50 Gy/25 fractions/5 weeks with a boost of 10 Gy. In recurrent cases, a full dose of radiotherapy was delivered. Clinical objective and complete response rates were 78% and 9% after IAIC. Despite a high rate of residual positive margin (67%) or clinically residual carcinoma, local recurrence developed only in 2 patients (6%) and local control rates at 5 years were calculated as 89%. Bone marrow suppression was frequent, and skin vesiculation (15%) and ulceration (9%) were experienced after IAIC. Skin ulcer (6%), brachial plexus neuropathy (3%), and radiation pneumonitis (3%) occurred as late toxicity. IAIC was effective as an induction treatment and radiotherapy played a role of local control for patients with locally advanced or recurrent breast cancer.

Adult↗
PubMed2001

Validity of local treatment including intraarterial infusion chemotherapy and radiotherapy for fungating adenocarcinoma of the breast: case report of more than 8-year survival.

A 39-year-old woman came to us complaining of severe anemia (hemoglobin: 2.3 g/dl) and a painful right breast that was entirely occupied by an ulcerative, foul-smelling tumor approximately 20 cm in maximum dimension. The tumor, which was determined to be mucinous adenocarcinoma at biopsy, had invaded the chest wall with multiple lung metastases (T4cN2M1 stage IV). After a blood transfusion, the patient received the following multimodal treatment: concurrent chemoradiotherapy (50 Gy), intraarterial infusion chemotherapy consisting of doxorubicin 50 mg, mitomycin-C 10 mg, and cisplatin 50 mg, and skin graft surgery. After intraarterial infusion chemotherapy, the fungating tumor disappeared. The patient experienced a relapse of right pleural effusion 2 years later and received multimodal treatment. Now, March 30, 2000, the patient is doing well without local recurrence, 8 years after her first admission. The combination of intraarterial infusion chemotherapy and radiotherapy plays a role in successful treatment of extensive local disease of the breast.

Adenocarcinoma, Mucinous↗
PubMed2001

Distinct PKC isozymes regulate bufalin-induced differentiation and apoptosis in human monocytic cells.

Bufalin, an Na(+)-K(+)-ATPase inhibitor, simultaneously induced cell differentiation and apoptosis in human monocytic leukemia THP-1 cells. In this study, we investigated the regulatory role of protein kinase C (PKC) isozymes in bufalin-induced cell differentiation and apoptosis. A PKC-specific but isozyme-nonselective inhibitor, Ro-31-8220, and a cPKC selective inhibitor, Gö-6976, caused significant attenuation of bufalin-induced interleukin-1beta (IL-1beta) gene expression, a mature monocytic marker, indicating that cPKC participates in the bufalin-induced cell differentiation. On the other hand, cPKCbeta- and nPKCdelta-defective THP-1/TPA cells displayed strong resistance to the bufalin-induced DNA ladder formation. Rottlerin, an nPKCdelta-specific inhibitor, partially attenuated preapoptotic effects of bufalin, such as the limited proteolysis of nPKCdelta and poly(ADP-ribose) polymerase and the cell staining by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling, suggesting that nPKCdelta is involved, at least in part, in bufalin-induced apoptosis. In contrast, Gö-6976 and rottlerin significantly augmented bufalin-induced apoptosis and differentiation, respectively. The findings suggest that bufalin-induced cell differentiation and apoptosis are interlinked and that distinct PKC isozymes are involved in the fate of the cell.

Apoptosis↗