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Biomedical subjects

M Taniguchi

Publications and source records attributed to M Taniguchi.

At least 271 records · Page 15Linked to original sources

UK-2A, B, C and D, novel antifungal antibiotics from Streptomyces sp. 517-02. IV. Comparative studies of UK-2A with antimycin A3 on cytotoxic activity and reactive oxygen species generation in LLC-PK1 cells.

UK-2A, a novel antifungal antibiotic, is a structural relative of antimycin A3 (AA) and its mode of action is similar to that of AA which inhibits mitochondrial electron transport at complex III. In spite of their structural resemblance, AA had strong cytotoxicity while UK-2A had little cytotoxicity against LLC-PK1 cells as well as other types of cultured cells. When cells were treated with UK-2A or with AA the intracellular ATP content decreased significantly within 5 minutes in glucose-free medium to almost the same extent in both cases. Moreover, under the same conditions, UK-2A killed cells at a similar rate to AA. This suggested that UK-2A entered into the cells and, like AA, inhibited mitochondrial electron transport. On the other hand, AA stimulated reactive oxygen species (ROS) production within 5 minutes even at a low concentration of 1 microM whereas UK-2A did not show such an effect. The difference in the ROS-producing abilities of UK-2A and AA may account for the different cytotoxic effects of the two compounds.

Animals↗

Mode of action of anhydrofulvic acid against Candida utilis ATCC 42402 under acidic condition.

The mode of action of anhydrofulvic acid against Candida utilis ATCC 42402 was investigated under acidic conditions. Anhydrofulvic acid inhibited the incorporation of radioactive precursors into DNA, RNA, protein and lipid fractions. Although it did not induce leakage of intracellular materials from the treated cells, it had inhibitory effects on both endogenous and exogenous cellular respiration. Moreover, it inhibited mitochondrial respiration of Candida utilis ATCC 42402 using both succinate and cytochrome c as respiratory substrates, but not using NADH. Unexpectedly, the inhibition against isolated mitochondria was observed at pH 7.0. These results suggested that the action site against the respiratory inhibition of anhydrofulvic acid might be involved in succinate dehydrogenase, complex II in the mitochondrial electron transport chain of the yeast cells. Judging from the inhibitory effect of anhydrofulvic acid on mitochondria detected at pH 7.0, it was postulated that the antifungal activity at a low pH level might depend on the elevation of drug permeability to the cell membrane under acidic conditions.

Antifungal Agents↗

UK-2A,B,C and D, novel antifungal antibiotics from Streptomyces sp.517.02. V. Inhibition mechanism of bovine heart mitochondrial cytochrome bc1 by the novel antibiotic UK-2A.

UK-2A is a potent antifungal antibiotic isolated from Streptomyces sp. 517-02 and its structure is highly similar to that of antimycin A. We investigated the inhibition mechanism of bovine heart mitochondrial cytochrome bc1 complex by the UK-2A using antimycin A and myxothiazol as the reference inhibitors of ubiquinol oxidation (Qo) and ubiquinone reduction (Qi) sites, respectively. The inhibitory potency of UK-2A was about 3-fold less than antimycin A. On the basis of the effects of UK-2A on the reduction kinetics of b and c1 hemes, this compound appeared to be an inhibitor of the Qi site. However, since spectral changes of dithionite-reduced cytochrome b induced by UK-2A binding differed from that of antimycin A, the precise binding manner of UK-2A to the enzyme is not identical to that of antimycin A. It could be concluded that antimycin A binding to cytochrome b is primarily decided by structural specificity of the salicylic acid moiety.

Animals↗

[Evaluation of the ketamine maintenance dose in anesthesia using propofol, ketamine and nitrous oxide].

We studied the influence of the ketamine maintenance dose on propofol infusion speed, blood pressure change and recovery time in anesthesia using propofol, ketamine and nitrous oxide. Anesthesia was maintained with ketamine 0.6 or 0.2 mg.kg-1.hr-1. The ketamine maintenance dose exerted no influence on propofol infusion speed, the occurrence of hypertension or hypotension. The recovery time correlated with the total amount of ketamine. From these results we conclude that 0.2 mg.kg-1.hr-1 is an appropriate maintenance dose of ketamine in anesthesia using propofol, ketamine and nitrous oxide.

Aged↗

[A case of spontaneous pyeloduodenal fistula].

A 61-year-old woman visited our hospital complaining of right flank pain and fever. The radiograph demonstrated multiple renal calculi. Radio renography showed no uptake in the right kidney. Therefore, we diagnosed her with pyonephrosis, and recommended open nephrectomy. However, she selected the conservative treatment with extra corporeal shockwave lithotripsy (ESWL). In spite of disappearance of multiple calculi, pyuria continued for 3 months after ESWL. Retrograde pyelography showed a fistula from the right pelvis into the duodenum. The patient was successfully treated by nephrectomy and duodeno-fistelectomy.

Duodenal Diseases↗

A single cell analysis of TCR AV24AJ18+ DN T cells.

The T-cell receptor (TCR) BV gene of human TCR AV24+ double-negative (DN) T cells, a novel subset of natural killer (NK) T cells, was investigated by single-cell sorting and single-cell polymerase chain reaction (PCR) methods. Seven of eleven TCR AV24+ DN T-cell clones utilized TCR BV8, three BV9, and one BV6. Six of seven TCR AV24/BV8+ DN T-cell clones had identical TCR beta and alpha chains, indicating that they were the same clone. All three TCR AV24/BV9+ DN T-cell clones also demonstrated the same amino acids in the CDR3 region. These findings strongly suggest that the usage of TCR beta and alpha chains on TCR AV24+ DN T cells is extremely restricted, supporting the notion that these cells recognize highly limited T-cell epitopes on antigens. All TCR AV24+ clones expressed the NKR-P1A mRNA, and so were true NK T cells. IL-2 and IL-4 mRNAs were detected in all clones, suggesting that the majority of these cells were Th0-type T cells. Six clones overexpressed Fas-ligand (Fas-L) mRNA and Fas antigen was detected on all clones at the mRNA level. In conclusion, TCR AV24+ DN T cells might recognize restricted T-cell epitopes on antigens and function as Th0-type T cells, inducer cells to Th1- or Th2-type T cells (regulatory T cells), and as Fas-L-positive cytolytic T cells.

Amino Acid Sequence↗

[A study of the long-term effectiveness of an outpatient pulmonary rehabilitation program].

Pulmonary rehabilitation is one of the most important components of comprehensive care for patients with significant disability due to chronic respiratory failure. Because pulmonary rehabilitation has not been popular in Japan, the long-term effectiveness of pulmonary rehabilitation has rarely been reported. We therefore examined the long-term effectiveness of an outpatient pulmonary rehabilitation program for patients with chronic respiratory failure. Our program was composed of a once-a-week introduction program for 2 months and a support program that was continued every 4 weeks as long as possible. Thirty stable patients with chronic respiratory failure were enrolled in the program; 21 patients (COPD: 15, lung complications of tuberculosis: 6) completed the 9-week introduction program and the ensuing 6-month support program. Good compliance with the home training regimen was maintained during the period. The introduction program significantly alleviated dyspnea (Fletcher's grade: 3.3 to 3.0, p < 0.01) and improved the data for activity (Spector's score: 5.3 to 5.8, p < 0.01) and 6-minute walking distance (319 to 384 m, p < 0.01). These benefits were sustained during the 6-month support program. We concluded that outpatient pulmonary rehabilitation can alleviate dyspnea and improve the activity and exercise tolerance of patients with chronic respiratory failure, and that the effectiveness of training can be well maintained with a minimal support program.

Activities of Daily Living↗

[Bacillus Calmette-Guerin intravesical instillation treatment for carcinoma in situ of the bladder. Gifu BCG Instillation Therapy Research Group].

We performed a retrospective long-term study to evaluate the efficacy of intravesical instillation of Tokyo 172 strain Bacillus Calmette-Guerin (BCG) on carcinoma in situ (CIS) of the bladder. Between 1989 and 1998, 42 patients with CIS of bladder underwent intravesical instillation of BCG. In the follow-up period from 6 to 116 months (mean: 37.3 months), the efficacy rate of intravesical BCG instillation for CIS of the bladder was 81.0%. Two patients died from the bladder cancer. The non-recurrence rate in patients with grade 2 carcinoma (19 cases) was not significantly different from that in those with grade 3 carcinoma (23 cases). However, the recurrence rate in patients with secondary CIS (15 cases) was significantly higher than in those with primary CIS (27 cases). The recurrence of CIS was observed in 7 of 42 cases. In 6 of 7 patients, CIS recurred within one year after treatment. Total cystectomy was performed in 10 of 42 patients, and pathological findings of muscle layer invasion were detected in 8 patients. Although side effects occurred in 33 patients (77.5%), no clinically significant side effects were observed. Our results suggest that intravesical BCG therapy may be useful for the treatment of CIS of the bladder.

Adjuvants, Immunologic↗

[Pheochromocytoma of the urinary bladder: a case report].

A 49-year-old man was hospitalized with the chief complaint of coagulation in urine. The patient was not hypertensive. Cystoscopic examination showed a submucosal tumor in the left lateral wall of the bladder. A transurethral sonogram revealed a low echoic nodule. Transurethral resection of the tumor in the urinary bladder was performed. The histopathological diagnosis indicated pheochromocytoma. Blood pressure was stable. After operation, the patient's course was uneventful, and there has been no recurrence for one year after surgery. This patient is the 52nd patient with pheochromocytoma of the urinary bladder reported in the Japanese literature.

Follow-Up Studies↗

[Factors which allow elderly persons living alone to continue living at home--analysis of the situation of elderly people living alone who are served by the Higashi Sapporo Hospital Home Care Support Center and Higashi Sapporo Visiting Nurse Station].

Amid the rapid ongoing shift from treating the elderly in hospitals to treating them at home, self-care by elderly people living alone is a serious and complicated problem. To investigate the support system that enables elderly living alone to maintain social independence and a high quality of life at home, the main factors which allow the person to continue living at home were sought through an analysis of the current situations of 44 elderly-persons living alone, who use the services of our home care support center and visiting nurse station. From this analysis, the elderly person who continue to live alone at home were ranked from J-A for degree of independence in daily life, and the degree of independence of in daily life of elderly suffering from dementia was normal rank I and II. It was also found that such people use multiple services and that their health is stable. In the future it will be necessary to develop systems and networks which function to coordinate multiple services and make possible the smooth transition between home and hospital or institution. The practice of informed consent must also be improved. Finally, it will be important to promote the appropriate management of disease and local rehabilitation services.

Activities of Daily Living↗

Preparation of a new thermo-responsive adsorbent with maltose as a ligand and its application to affinity precipitation.

A thermo-responsive polymer on which maltose was covalently immobilized as an affinity ligand was newly synthesized for purification of thermolabile proteins from the crude solution by affinity precipitation. Among the thermo-responsive polymers synthesized as carriers for adsorbent, poly(N-acryloylpiperidine)-cysteamine (pAP) has a lower critical solution temperature (LCST) of around 4 degrees C, at which its solubility exhibits a sharp change. Adsorbent for affinity precipitation was prepared by combining pAP with maltose using trimethylamine-borane as a reducing reagent. This adsorbent (pAPM) obtained showed a good solubility response: pAPM in the basal buffer (pH 7.0) became soluble below 4 degrees C and was completely insoluble above 8 degrees C. The affinity precipitation method using pAPM consisted of the following four steps: adsorption at 4 degrees C, precipitation of the complex at 10 degrees C, desorption by adding the desorption reagent at 4 degrees C, and recovery of a target protein at 10 degrees C. In the affinity precipitation of Con A from the crude extract of jack bean meal, 82% of Con A added was recovered with 80% purity by addition of 0.2 M methyl-alpha-D-mannopyranoside as a desorption reagent. In the repeated purification of Con A from the crude extract, pAPM could be satisfactorily reused without decrease in the affinity performance. Moreover, when pAPM was used for the purification of thermolabile alpha-glucosidase from the cell-free extract of Saccharomyces cerevisiae, 68% of total activity added was recovered and the specific activity per amount of protein of the purified solution was enhanced 206-fold higher than that of the cell-free extract without thermal deactivation of the enzyme.

Adsorption↗

Association between genetic polymorphisms of glutathione S-transferase P1 and N-acetyltransferase 2 and susceptibility to squamous-cell carcinoma of the esophagus.

We examined the effect of genetic polymorphisms of phase-II enzymes, glutathione S-transferase P1 (GSTP1) and N-acetyltransferase2 (NAT2) on susceptibility to esophageal squamous-cell carcinoma To determine the genotypes of the 2 polymorphisms, PCR-based analysis was performed on samples from 66 Japanese patients who had been histologically diagnosed as having esophageal squamous-cell carcinoma, and 164 healthy Japanese controls. The frequency of the AA genotype of GSTP1 was significantly higher in esophageal-cancer patients than in the controls according to logistic-regression analysis (92% of the patients and 68% of the controls; odds ratio (OR), 8.0; p = 0.0013). Also, more patients had the slow and intermediate acetylator genotypes of NAT2 than the controls (15% and 38% vs. 10% and 32% respectively; OR of the slow acetylator genotype, 4.2; p = 0.032; OR of the slow plus intermediate acetylator genotypes, 2.9; p = 0.015). Polymorphisms of GSTP1 and NAT2 may serve as genetic biomarkers for predicting susceptibility to esophageal squamous-cell carcinoma.

Adult↗

Selective ability of mouse CD1 to present glycolipids: alpha-galactosylceramide specifically stimulates V alpha 14+ NK T lymphocytes.

Mouse CD1 (mCD1) glycoproteins are known to present peptides, while human CD1 molecules present glycolipids. In mice, mCD1-autoreactive NK T cells play critical roles in various immune responses, through the secretion of high amounts of cytokines. This study was initiated to determine whether glycolipids are involved in the autorecognition of mCD1 by NK T cells. Alpha-galactosylceramide (alpha-GalCer) was the only glycolipid tested capable of eliciting an mCD1-restricted response by splenic T cells. Moreover, splenic T cells derived from mCD1-deficient mice were not stimulated by alpha-GalCer, suggesting that the responsive T cells are selected by mCD1. Using cytoflow techniques, we confirmed that, in response to alpha-GalCer, IFN-gamma-secreting cells displayed an NK T cell phenotype. The predominance of IFN-gamma vs IL-4, however, is determined by the type of mCD1+ APC, suggesting the potential for APC regulation of cytokine production by NK T cells. Among a panel of 10 mCD1-autoreactive T cell hybridomas, only the ones that express the typical V alpha 14 J alpha 281 TCR rearrangement of NK T cells responded to alpha-GalCer. Fixation or treatment of mCD1+ APCs with an inhibitor of endosomal acidification and the use of mCD1 mutants unable to traffic through endosome still allowed alpha-GalCer to stimulate NK T cells. Thus, endosomal trafficking and Ag processing are not required for glycolipid recognition. In summary, alpha-GalCer might be the autologous ligand, or a mimic of a glycolipid ligand, involved in the mCD1-mediated stimulation of NK T cells.

Animals↗

Solid phase micro extraction coupled with semi-microcolumn high performance liquid chromatography for the analysis of benzodiazepines in human urine.

SPME/semi-microcolumn HPLC (SPME/LC) was investigated to analyze benzodiazepines in human urine samples. SPME conditions such as extraction time, extraction temperature, salt concentration and pH of matrix, flush volume and desorption time were optimized by extracting various drugs from a prepared water matrix. Combination of adding saturated salts to the matrix and controlling pH ranged from neutral to weakly alkaline conditions makes the increase of extraction efficiency. Under optimal condition SPME/LC is more sensitive than direct HPLC analysis without the SPME process. The limits of detection (LODs) was several ppb level and the relative standard deviation (RSD) was < 15% when human urine samples were analyzed by this analytical system. The system is very useful and is enough to assay benzodiazepines in a human urine sample without tedious and complex analytical procedures. In this paper the applicability of SPME/LC to the analysis of benzodiazepines in human urine samples was reported. In addition, the extension to the evaluation of SPME/LC/MS system was also described.

Benzodiazepines↗