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N Nishimura

Publications and source records attributed to N Nishimura.

At least 37 records · Page 2Linked to original sources
PubMed2001

Synthesis of pyrrolo[2,1-f][1,2,4]triazine C-nucleosides. Isosteres of sangivamycin, tubercidin, and toyocamycin.

Syntheses of pyrrolo[2,1-f][1,2,4]triazine C-nucleosides are reported. Treatment of pyranulose glycoside with aminoguanidine in acetic acid gave the corresponding semicarbazone in 96% yield. The ring transformation of the semicarbazone in dioxane afforded a 51% yield of 2-amino-7-(2,3,5-tri-O-benzoyl-beta-D-ribofuranosyl)pyrrolo[2,1-f]-[1,2,4]triazine. Vilsmeier formylation of the pyrrolotriazine gave the major product, 5-formylpyrrolo[2,1-f][1,2,4]triazine, in 69% yield. The aldehyde was treated with hydroxylamine hydrochloride in methanol to give aldoximes. Dehydration of aldoxime with trifluoromethanesulfonic anhydride and triethylamine in dichloromethane afforded 5-cyanopyrrolo[2,1-f][1,2,4]triazine in 44% yield. Conversion of the nitrile to the deprotected amide, 2-amino-7-(beta-D-ribofuranosyl)pyrrolo[2,1-f][1,2,4]triazine-5-carboxamide, was accomplished in 96% yield on treatment with 30% H2O2 in ethanol for 1 day at room temperature. Debenzoylation with sodium hydroxide solution produced deprotected C-nucleosides.

Antibiotics, Antineoplastic↗
PubMed2001

Enhanced efficiency by centrifugal manipulation of adenovirus-mediated interleukin 12 gene transduction into human monocyte-derived dendritic cells.

Transduction of dendritic cells (DCs) with genes encoding tumor-associated antigen or with other genes that enhance immune reaction has been theorized to be potentially useful for enhancing the efficiency of DC-based immunotherapy. However, gene transduction of DCs generated from human peripheral blood monocytes has been of limited use because of the low efficiency. Here, we report that the efficiency of in vitro adenovirus-mediated gene transduction into human monocyte-derived DCs can be dramatically enhanced by centrifugation. The best conditions for centrifugal gene transduction were determined to be as follows: 2000 x g at 37 degrees C for 2 hr at a multiplicity of infection (MOI) of 10 or greater. By this centrifugal method, approximately 88 and 70% of DCs were gene transducible at an MOI of 50 and 10, respectively. Functional analysis showed that DCs transduced with human interleukin 12 (IL-12)-expressing adenoviral vector under the optimal conditions of centrifugation stably produced IL-12 protein at high levels (8.1 ng/10(6) cells/48 hr). IL-12 gene-modified DCs (DC/IL-12) displayed a more mature phenotype than nontransduced DCs, as judged by decreased expression of CD1a and increased expression of CD83, B7.1 (CD80), B7.2 (CD86), and MHC class I and II molecules. DC/IL-12 showed a high phagocytic ability similar to nontransduced DCs and were significantly superior to control DCs in the stimulation of autologous and allogeneic T lymphocyte responses. The centrifugal transduction method with adenoviral vector might be useful for efficient generation of gene-modified DCs because it is very simple, highly efficient, reproducible, and not cytopathic. IL-12 gene-modified human DCs may be therapeutically useful as a good adjuvant in DC-based immunotherapy.

Adenoviridae↗
PubMed2001

Nuclear factor-kappaB-dependent expression of metastasis suppressor KAI1/CD82 gene in lung cancer cell lines expressing mutant p53.

KAI1/CD82 has been shown to be a metastasis suppressor for several human cancers, and a recent study revealed that wild-type tumor suppressor p53 can directly activate KAI1/CD82 gene expression. However, the response of KAI1/CD82 expression in cancer cells to exogenous stimulants has not been investigated. The present study examined whether tumor necrosis factor (TNF), which mediates many of the cellular responses associated with inflammatory reactions or cancer progression, can affect the KAI1/CD82 expression in lung cancer cells and, if so, whether nuclear factor (NF)-kappaB, a key molecule in TNF-mediated gene expression, is involved in the mechanism of KAI1/CD82 induction. Our results demonstrated that expression of KAI1/CD82 in PC-14 cells expressing mutant p53 could be augmented by TNF-alpha, and that transfer of the gene for a specific inhibitor of NF-kappaB, IkappaB alphaSR (mutant IkappaB alpha; NF-kappaB super-repressor), into PC-14 cells could inhibit this augmentation. The amount of NF-kappaB in the nucleus of PC-14/IkappaB alphaSR cells correlated well with KAI1/CD82 mRNA and protein expression. In addition, IkappaB alphaSR gene transfer inhibited the spontaneous expression of KAI1/CD82 protein in KAI1/CD82-high-expressing RERF-LC-OK cells, which contain a mutant-type p53. These observations indicate that NF-kappaB activation may play a role in the regulation of KAI1/CD82 expression in lung cancer cells independently of wild-type p53, and suggest that KAI1/CD82 expression may be regulated by interaction with the host microenvironment.

Antigens, CD↗
PubMed2001

Human monocyte-derived and CD83(+) blood dendritic cells enhance NK cell-mediated cytotoxicity.

Dendritic cells (DC) are known to be the most potent APC and to stimulate antigen-specific T cell responses. Recently it was reported that murine DC were also capable of modulating the innate immunity by stimulating NK cells through cell-to-cell contact. In the present study, we examined whether human DC could affect NK activity. Both monocyte-derived and CD83(+) blood DC were tested. The addition of DC to cultures of CD56(+) cells resulted in the significant dose-dependent enhancement of the killing activity against various NK-sensitive targets. The resultant activity was comparable to that induced by optimal concentrations of various cytokines, including IL-2, IL-12, IL-15 and IFN-gamma. Interestingly, DC enhanced the cytotoxicity of CD3(-)CD56(+) NK cells, but not that of CD3(+)CD56(+) T cells. Experiments using transwells clearly demonstrated that the enhancement of NK activity by DC was mediated by soluble factors produced by DC. The culture supernatants of DC also stimulated NK activity. The treatment of both DC and their supernatants with anti-human IL-12 or IL-18 antibodies did not block the enhancement of NK cell-mediated cytolysis by DC, indicating that other factor(s) produced by DC were responsible for the enhancement of NK activity. These results suggest that human myeloid DC can modulate innate immunity by enhancing NK activity.

Antibodies↗
PubMed2001

Acute and 6-month clinical and angiographic outcome after implantation of the ACS Duet stent for single-vessel coronary artery disease: final results of the European and US ACS Multi-link Duet Registry.

The aim of the study was to determine the safety and efficacy of the second-generation ACS Multi-Link Duet coronary stent system for the treatment of single, symptomatic, de novo, native coronary artery lesions. Between February and June 1998, 427 patients (69.3% male, 51.5% class 3 or 4 angina, 20.1% diabetic, 43.6% hyperlipidemia) were included at 38 centers in this prospective observational study. All patients received ticlopidine 500 mg/day for 1 month and aspirin > or =100 mg/day. The Duet stent was available in 8, 18, and 28 mm length and 3.0, 3.5, and 4.0 mm diameter. After adequate predilatation, stents were successfully implanted, at up to 16 atm, in 99.3% of patients. Mean vessel diameter by core laboratory quantitative coronary angiography was 3.0 +/- 0.53 mm and postprocedural minimum luminal diameter was 2.79 +/- 0.43 mm (12% +/- 9.3% diameter stenosis). At 30 days, 96.7% of patients were event-free and at 6 months 88.1% remained free of major adverse cardiac events. The restenosis rate was 18.1%. The ACS Duet stent was safely implanted in >99% of target lesions by a diverse group of international investigators. With late outcomes at least comparable to the best published results, this stent platform provides safe and effective percutaneous treatment of obstructive coronary artery disease. Cathet Cardiovasc Intervent 2001;54:25-33.

Aged↗
PubMed2001

Gene expression analysis in colorectal cancer using practical DNA array filter.

PURPOSE: We examined the usability of a newly developed, compact-sized DNA array filter for studying the gene expression pattern of individual colorectal cancer. METHODS: Complementary DNA probes were prepared from mRNA extracted from colonic cancer specimens and adjacent normal mucosa and then were labeled with chemiluminescence. These labeled probes were allowed to bind to the gene fragments on the filter. A specialized scanning charge-coupled device camera measured the intensity of each chemiluminescent spot, which is an indicator of the degree to which a specific gene is expressed. Gene expression image was quantified into intensity of signals by using computer software. RESULTS: Characteristic gene expression patterns were obtained from the colonic cancer cell line, RPMI4788, and the leukemia cell line, HL60, by using this compact-sized DNA array filter in the preliminary experiment. Up-regulation of nm23, TIMP1, VEGF, and cyclin E and down-regulation of some tumor suppressor genes (p53, TOSO, and SIVA), beta-catenin, and metallothionein were observed in colonic cancer specimen when compared with those of normal mucosa. CONCLUSIONS: We have obtained unique gene expression patterns from colorectal cancer and normal tissue by using a newly developed compact-sized DNA array filter system. Collecting, storing, and analyzing of gene expression data from many samples of colorectal cancer will enable us to identify distinct subsets of patients based on molecular characteristics in the near future.

Cell Line↗
PubMed2001

The effects of facial fanning on thermal comfort sensation during hyperthermia.

We studied how facial fanning during hyperthermia improves the thermal comfort sensation. Experiments were carried out on ten male subjects. They were immersed in hot water at 40 degrees C for 45 min. At 20 min and 35 min, fanning (1 m x s(-1)) was applied to their faces for 5 min. Core temperature (Tc) measured as esophageal temperature (Tes) and tympanic temperature (Tty) continued to rise during the immersion, but temporarily decreased during fanning with a delay of 2 or 3 min. Skin temperatures (Ts) on the forehead and cheek continued to increase slightly during immersion, but decreased immediately after the start of fanning. During immersion before face fanning, the time trend of thermal sensation towards the warm level was similar to that of skin temperature on the face, whereas the time trend of thermal comfort ratings towards the uncomfortable level was similar to that of Tc. The scores of both thermal sensation and thermal comfort were reduced significantly immediately after the start of fanning, and their time courses were different to those of Ts and Tty. These results support previous reports that thermal sensation depends on skin temperature, and that thermal comfort depends on both the skin and core temperatures. Moreover, they indicate that both thermal sensation and comfort ratings are affected by the dynamic responses of the cutaneous thermoreceptors when fanning is applied to the face during hyperthermia.

Adult↗
PubMed2001

Efficient generation of dendritic cells from alveolar and pleural macrophages as well as blood monocytes in patients with lung cancer.

In this study, we investigated the generation of dendritic cells (DCs) from blood monocytes and mature macrophages from untreated primary lung cancer patients. Blood monocytes were separated by adherence from blood mononuclear cells (MNC) from ten lung cancer patients and ten control subjects, and cultured for 7 days in medium with granulocyte/macrophage colony-stimulating factor (GM-CSF) plus interleukin (IL-) 4. In all cases examined, DCs with typical characteristics were obtained even in lung cancer patients after 7 days culture with these cytokines, and there was no significant difference in phenotype and stimulatory activity in allogeneic lymphocyte proliferation between DCs derived from monocytes from lung cancer patients and those from control subjects. Next, we examined whether alveolar and pleural macrophages in malignant pleural effusion separated by magnetic beads could differentiate to immunostimulatory DCs. Conventional culture conditions with GM-CSF and IL-4 did not induce efficient numbers of DCs from mature macrophages, whereas the addition of tumor necrosis factor-alpha (TNF-alpha) to GM-CSF and IL-4 effectively contributed to generate DCs. These findings suggest that both mature macrophages and blood monocytes from lung cancer patients could differentiate to DCs, and might be a useful source of DCs for immunotherapy.

Aged↗
PubMed2001

Maternal exposure to a low dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) suppressed the development of reproductive organs of male rats: dose-dependent increase of mRNA levels of 5alpha-reductase type 2 in contrast to decrease of androgen receptor in the pubertal ventral prostate.

To assess the health risks associated with exposure to 2,3,7,8-tetrachlorodebenzo-p-dioxin (TCDD), we studied the effects of a relatively low dose of TCDD on the male reproductive system of rats, using the experimental protocol of T. A. Mably et al. (1992, Toxicol. Appl. Pharmacol. 114, 97-107, 108-117, 118-126), and searched for the most sensitive and reliable among several indices of TCDD toxicity. Pregnant Holtzman rats were given a single oral dose of 0, 12.5, 50, 200, or 800 ng TCDD/kg body weight on gestational day (GD) 15, and male offspring were sacrificed on postnatal day (PND) 49 or 120. GC-MS analysis of the abdominal fat tissue and testis clearly showed increased amounts of TCDD in these offspring. However, there was no TCDD effect on body weight of offspring. There were no changes on testicular or epididymal weights by TCDD administration, even at the 800-ng/kg dose in rats sacrificed on either PND 49 or 120. In addition, TCDD administration resulted in no changes in daily sperm production or sperm reserve at any of the doses used. However, the weight of the urogenital complex, including the ventral prostate, was significantly reduced at doses of 200 and 800 ng TCDD/kg in rats sacrificed on PND 120. Moreover, the anogenital distance (AGD) of male rats sacrificed on PND 120 showed a significant decrease in the groups receiving doses greater than 50 ng TCDD/kg. TCDD administration resulted in no apparent dose-dependent changes in levels of either serum testosterone or luteinizing hormone. Interestingly, reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed that, in the ventral prostates of the PND 49 group, TCDD administration resulted in both a dose-dependent increase in 5alpha-reductase type 2 (5alphaR-II) mRNA level and a dose-dependent decrease in androgen receptor (AR) mRNA level. These results suggest that low-dose TCDD administration had a greater effect on the development of the external genital organs and ventral prostate than on development of the testis and other internal genital organs. Moreover, it is highly suggested that the decrease in the size of the ventral prostate by maternal TCDD exposure might be due to decreased responsiveness of the prostate to androgen due to an insufficient expression level of androgen receptor during puberty.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed2001

Identification of endogenous ouabain in culture supernatant of PC12 cells.

OBJECTIVE: Ouabain-like factor (OLF), assayed as ouabain-like immunoreactivity (OLI), is thought to represent an endogenous digitalis-like factor. We found increased plasma OLI during the surgical removal of a pheochromocytoma. The elution volume of the OLI extracted from plasma and the pheochromocytoma tissue was the same as that for authentic ouabain, using reverse phase high-performance liquid chromatography. The present study was performed to characterize OLF from the culture supernatant of a rat pheochromocytoma cell line, PC12 cells. DESIGN: OLI from culture supernatant and chromatographic fractions were assayed by a sensitive enzyme-linked immunosorbent assay for ouabain. PC12 cells, subcultured in RPMI 1640 with 10% horse serum and 5% fetal bovine serum, were washed, and then cultured in Iscove's modified Dulbecco's medium (Life Technologies, Rockville, Maryland, USA) with 0.4% bovine serum albumin (without serum). Progesterone was added to augment the production or secretion of OLI. The conditioned medium was acidified to dissociate the binding protein, and OLI was purified by five steps of octadecylsilane (ODS) column chromatography. The structural identity of this OLI was determined by liquid chromatography and mass spectrometry (LC/MS). RESULTS: OLI in the culture medium increased after addition of progesterone in a dose-dependent manner. The concentration in the culture medium was approximately double of that in homogenized PC12 cells. After five rounds of ODS column chromatography, approximately 100 ng of OLI was purified from 21 of culture supernatant, without fetal calf serum, in the presence of progesterone. The molecular size of purified OLI was found to be identical to authentic ouabain, based on analysis by LC/ MS. CONCLUSION: Mammalian cells originating from a rat pheochromocytoma cell line were found to produce and/or secrete OLF by the addition of progesterone.

Animals↗
PubMed2001

Large-scale cDNA analysis of the maternal genetic information in the egg of Halocynthia roretzi for a gene expression catalog of ascidian development.

The ascidian egg is a well-known mosaic egg. In order to investigate the molecular nature of the maternal genetic information stored in the egg, we have prepared cDNAs from the mRNAs in the fertilized eggs of the ascidian, Halocynthia roretzi. The cDNAs of the ascidian embryo were sequenced, and the localization of individual mRNA was examined in staged embryos by whole-mount in situ hybridization. The data obtained were stored in the database MAGEST (http://www.genome.ad.jp/magest) and further analyzed. A total of 4240 cDNA clones were found to represent 2221 gene transcripts, including at least 934 different protein-coding sequences. The mRNA population of the egg consisted of a low prevalence, high complexity sequence set. The majority of the clones were of the rare sequence class, and of these, 42% of the clones showed significant matches with known peptides, mainly consisting of proteins with housekeeping functions such as metabolism and cell division. In addition, we found cDNAs encoding components involved in different signal transduction pathways and cDNAs encoding nucleotide-binding proteins. Large-scale analyses of the distribution of the RNA corresponding to each cDNA in the eight-cell, 110-cell and early tailbud embryos were simultaneously carried out. These analyses revealed that a small fraction of the maternal RNAs were localized in the eight-cell embryo, and that 7.9% of the clones were exclusively maternal, while 40.6% of the maternal clones showed expression in the later stages. This study provides global insights about the genes expressed during early development.

Animals↗
PubMed2001

Changes in the dissolution of tolbutamide by a traditional Chinese medicine, Sho-saiko-to (Xiao Chaihu Tang).

Dissolution rate is considered an important factor affecting absorption and efficacy after the oral administration of tolbutamide. Since in many cases traditional Chinese medicines, including Sho-saiko-to (TJ-9, Xiao Chaihu Tang), are taken with other drugs, it is likely that the dissolution and absorption of concomitant drugs in the gastrointestinal tract are influenced by the presence of traditional Chinese medicines. In this study, the effects of TJ-9 on the in vitro dissolution of tolbutamide were examined. We carried out the dissolution test of tolbutamide in the absence or presence of traditional Chinese medicines (Kakkon-to, TJ-1; Hachimi-jio-gan, TJ-7; Chorei-to, TJ-40; Shakuyaku-kanzo-to, TJ-68; TJ-9; Glycyrrhizae Radix, GR; glycyrrhizin, GL) by using a pH 1.2 dissolution medium. Tolbutamide was determined by HPLC assay. The moment parameters, ie., mean dissolution time (MDT), and the dissolution rate constant up to 20 min (kd) were estimated from the dissolution profiles on the basis of the first-order kinetics. Preparations containing GR, namely TJ-1, TJ-9 and TJ-68, significantly reduced the kd and increased the MDT of tolbutamide, while TJ-7 and TJ-40 had no effect on the early dissolution profile of tolbutamide. The extent of decrease in the kd in the presence of TJ-1, TJ-9 and TJ-68 was dependent on their GR contents. Similar inhibitory effects on the dissolution rate of tolbutamide were observed when GR alone was added to the test medium. In addition, GL, a major constituent of GR, induced a 50% increase in MDT and a 30% decrease in kd. The above results indicate that Chinese traditional preparations containing GR have an inhibitory effect on the in vitro dissolution of tolbutamide, which is derived from GL in the preparations.

Algorithms↗
PubMed2001

Effects of sho-saiko-to (xiao chai hu tang), a Chinese traditional medicine, on the gastric function and absorption of tolbutamide in rats.

This study was carried out to investigate the effects of Sho-saiko-to (Xiao Chai Hu Tang), a Chinese traditional medicine, on the gastric function including the gastric emptying rate (GER) and intragastric pH in rats. Additionally, the effects of the GER and intragastric pH on tolbutamide absorption after oral administration were examined. The GER measured at 40 min after dosing was reduced to about 70% by the pretreatment of Sho-saiko-to (500 mg/kg). The plasma tolbutamide concentration in the rats treated with a 250 mg/kg dose of Sho-saiko-to was significantly lower than that in the control group. Plasma tolbutamide concentrations increased along with the GER in the group co-administered Sho-saiko-to, and there were significant correlations between the GERs and plasma levels in both time points at 20 and 40 min after administration. In the study using pylorus-ligated rats, Sho-saiko-to significantly elevated the intragastric pH, but induced no change in the concentrations of tolbutamide dissolved in the gastric content. Additionally, Sho-saiko-to did not change the area under the plasma concentration-time curve (AUC) of tolbutamide up to 60 min after administration into the stomach loop, and gastric absorption has been considered to minimally contribute to whole absorption of tolbutamide in the gastrointestinal tract. These results indicate that Sho-saiko-to has an inhibitory effect on the function of gastric emptying in rats. The reduced gastric emptying could affect gastrointestinal absorption, resulting in the lower plasma concentration of tolbutamide after oral administration. Furthermore, it is suggested that Sho-saiko-to can raise the intragastric pH but affect neither the intragastric dissolution nor the gastric absorption of tolbutamide.

Administration, Oral↗
PubMed2001

Application of capillary electrophoresis to the simultaneous determination of betaines in plants.

The simultaneous determination of betaines, the key compounds for osmotic regulation in plants, was established by capillary electrophoresis (CE). After four betaines, glycine betaine (GB), beta-alanine betaine (AB), proline betaine (PB), and 2-hydroxyproline betaine (HPB), were esterified with p-bromophenacyl bromide, the esters were electrophoresed in 100 mM sodium phosphate at pH 3.0. A low-pH condition in CE and esterification gave an advantage of resolving each of the ester peaks as well as those of the unreacted reagent and other components. Furthermore, the addition of 4% polyethylene glycol (PEG) gave a better resolution of 4 peaks, resulting in the separation of the overlapped peaks of PB and AB. It was found from the standard addition method being applied to barley leaves that the GB content in plants could be evaluated by using a calibration curve of the GB standard solution. The extraction of GB from plant leaves was also improved by adopting water as the extraction solvent instead of a mixture of organic solvents. The present method was suitably applied to actual plant specimens collected from a saline area of China.

Acetonitriles↗
PubMed2001

Modest overexpression of neuropeptide Y in the brain leads to obesity after high-sucrose feeding.

Neuropeptide Y (NPY), one of the most abundant peptide transmitters in the mammalian brain, is assumed to play an important role in feeding and body weight regulation. However, there is little genetic evidence that overexpression or knockout of the NPY gene leads to altered body weight regulation. Previously, we developed NPY-overexpressing mice by using the Thy-1 promoter, which restricts NPY expression strictly within neurons in the central nervous system, but we failed to observe the obese phenotype in the heterozygote. Here we report that in the homozygous mice, overexpression of NPY leads to an obese phenotype, but only after appropriate dietary exposure. NPY-overexpressing mice exhibited significantly increased body weight gain with transiently increased food intake after 50% sucrose--loaded diet, and later they developed hyperglycemia and hyperinsulinemia without altered glucose excursion during 1 year of our observation period.

Aging↗
PubMed2000

Novel ring transformation of 5-(2,3,5-tri-O-benzoyl-beta-D-ribofuranosyl)-isoxazole-4-carbaldehyde with 1,2-diaminobenzenes to 3-cyano-1,5-benzodiazepine C-nucleosides.

Syntheses of 3-cyano-7- and 8-substituted-4-(beta-D-ribofuranosyl)-1H-1,5-benzodiazepines were reported. Treatment of isoxazole carbaldehyde with 1,2-diamino-4-nitrobenzene in chloroform gave a Schiffs base, 4-(2-amino-5-nitrophenyl)iminomethyl-5-(2,3,5-tri-O-benzoyl-beta-D-ribofuranosyl)isoxazole in 82% yield with no trace of the other regioisomer. The cyclocondensation of the resulting Schiffs base in benzene containing trifluoroacetic acid (TFA) gave 3-cyano-8-nitro-4-(2,3,5-tri-O-benzoyl-beta-D-ribofuranosyl)-1H-1,5-benzodiazepine in 49% yield. The same reaction of isoxazole carbaldeyde with 1,2-diamino-4-methoxy- and 4-chlorobenzenes afforded the corresponding Schiffs bases. Extending the reaction time for Schiffs base gave the corresponding cyanobenzodiazepines in good yields. Debenzoylation of the compounds with sodium methoxide produced deprotected C-nucleosides.

Aldehydes↗
PubMed2000

Usefulness of stent length in predicting in-stent restenosis (the MULTI-LINK stent trials).

The cumulative experience of 4 clinical trials using the MULTI-LINK coronary stent design was analyzed. Multivariable logistic regression identified postprocedure in-stent minimum lumen diameter (p = 0.0001), stent length (p = 0.0038), smoking (p = 0.0105). and diabetes (p = 0.0803) as the most important predictors of in-stent restenosis at late (6- to 9-month) angiographic follow-up.

Adult↗