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T Tokuyama

Publications and source records attributed to T Tokuyama.

At least 19 recordsLinked to original sources
PubMed2000

A novel degradative pathway of 2-nitrobenzoate via 3-hydroxyanthranilate in Pseudomonas fluorescens strain KU-7.

A bacterial strain KU-7, identified as a Pseudomonas fluorescens by 16S rDNA sequencing, was one of the 12 new isolates that are able to grow on 2-nitrobenzoate as a sole source of carbon, nitrogen, and energy. Resting cells of KU-7 were found to accumulate ammonia in the medium indicating that degradation of 2-NBA proceeds through a reductive route. Metabolite analyses by thin layer chromatography and high pressure liquid chromatography indicated that 3-hydroxyanthranilate is an intermediate of 2-nitrobenzoate metabolism in KU-7 cells. This offers an alternative route to 2-nitrobenzoate metabolism since anthranilate (2-aminobenzoate) or catechol were detected as intermediates in other bacteria. Crude extracts of KU-7 cells converted 2-nitrobenzoate to 3-hydroxyanthranilate with oxidation of 2 mol of NADPH. Ring cleavage of 3-hydroxyanthranilate produced a transient yellow product, identified as 2-amino-3-carboxymuconic 6-semialdehyde, that has a maximum absorbance at 360 nm. The initial enzymes of the 2-nitrobenzoate degradation pathway were found to be inducible since succinate-grown cells produced very low enzyme activities. A pathway for 2-nitrobenzoate degradation in KU-7 was proposed.

3-Hydroxyanthranilic Acid↗
PubMed2000

Physical model-based indirect measurements of blood pressure and flow using a centrifugal pump.

This article describes a technique offering indirect measurements of pump pressure differential and flow with certain accuracy independent of changes in blood viscosity. This technique is based on noninvasive measurements of the motor current and rotation speed using the physical model equations of the centrifugal pump system. Blood viscosity included in the coefficients of the dynamic equations is first estimated, and then substitution of the estimated viscosity into the steady equations of the model provides pump flow and pressure differential. In vitro tests using a Capiox pump showed a sufficient linear correlation between actual values and their estimates for pressure differential and pump flow. An in vivo test using a 45 kg sheep showed that the proposed algorithm needs robustness for the convergence of estimates of viscosity. An overall evaluation, however, of the developed algorithm/model showed indications of success in terms of efficient computation and modeling.

Algorithms↗
PubMed2000

Effects of haemodialysis on diabetic macular leakage.

AIM: To evaluate the effects of haemodialysis on macular oedema by fluorescein angiography in patients with diabetic retinopathy and end stage renal disease. METHODS: In this prospective study, fluorescein angiography was performed on 40 eyes of 22 non-insulin dependent diabetic patients with end stage renal disease just before (baseline) and 4 weeks after the beginning of haemodialysis. The change of macular leakage was determined by evaluating the same phase of the angiograms. RESULTS: Fluorescein angiograms obtained at 4 weeks showed that macular leakage was unchanged in 28/40 eyes (70%), decreased in 4/40 eyes (10%), and increased in 8/40 eyes (20%) when compared with the baseline appearance. CONCLUSIONS: These results indicate that haemodialysis does not benefit macular leakage in diabetic patients receiving haemodialysis for end stage renal disease.

Aged↗
PubMed2000

Purification and characterization of cyclohexanone 1,2-monooxygenase from Exophiala jeanselmei strain KUFI-6N.

Baeyer-Villiger cyclohexanone 1,2-monooxygenase (CHMO) was purified 17.1-fold from cell extracts of the fungus Exophiala jeanselmei grown on cyclohexanol to electrophoretically homogeneity by serial chromatographies. The molecular mass of the native enzyme was approximately 74 kDa by gel filtration and SDS-PAGE. Some enzymic characterizations were studied. The NH2-terminal amino acid residues were Ala-Lys-Ser-Leu-Asp-Val-Leu-Ile-Val-Gly-Ala-Gly-Phe-Gly-Gly-Ile-Tyr-Gln-Leu-, with similarity to the bacterial CHMOs of FAD-binding and NADPH-dependent type Baeyer-Villiger monooxygenases.

Amino Acid Sequence↗
PubMed1999

Occurrence and significance of decahydroquinolines from dendrobatid poison frogs and a myrmicine ant: use of 1H and 13C NMR in their conformational analysis

Structures for 2,5-disubstituted decahydroquinolines (DHQs) are reported for the two diastereomeric pairs cis-275B (14) and cis-275B' (15) and 5-epi-trans-269AB (18) and trans-269AB (19), all isolated from skin extracts of dendrobatid frogs, and for 5-epi-cis-275B' (16) and 5-epi-trans-275B (17) found in the extracts of virgin queens of a myrmicine ant [Solenopsis (Diplorhoptrum) azteca]. Detection of such DHQs in an ant, their first reported occurrence, strengthens a dietary hypothesis for the origin of the approximately 30 DHQs that have been detected in extracts of frog skin. NMR data on the two conformers of cis-decahydroquinoline permit assignment of ring conformations and stereochemistry to cis-DHQs of the "N-endo" type or the "N-exo" type. These conformations are also assigned on whether H-8a is equatorial or axial as determined with E-COSY or 1D-HOHAHA spectra.

Journal Article↗
PubMed1999

Identification of a transcriptional activator (ChnR) and a 6-oxohexanoate dehydrogenase (ChnE) in the cyclohexanol catabolic pathway in Acinetobacter sp. Strain NCIMB 9871 and localization of the genes that encode them.

We identified chnR, a gene encoding an AraC-XylS type of transcriptional activator that regulates the expression of chnB, the structural gene for cyclohexanone monooxygenase (CHMO) in Acinetobacter sp. strain NCIMB 9871. The gene sequence of chnE, which encodes an NADP(+)-linked 6-oxohexanoate dehydrogenase, the enzyme catalyzing the fifth step of cyclohexanol degradation, was also determined. The gene arrangement is chnB-chnE-chnR. The predicted molecular masses of the three polypeptides were verified by radiolabeling by using the T7 expression system. Inducible expression of cloned chnB in Escherichia coli depended upon the presence of chnR. A transcriptional chnB::lacZ fusion experiment revealed that cyclohexanone induces chnB expression in E. coli, in which a 22-fold increase in activity was observed.

Acinetobacter↗
PubMed1999

Biodegradation of cyclohexylamine by Brevibacterium oxydans IH-35A.

A bacterial strain capable of growing on cyclohexylamine (CHAM) was isolated by using enrichment and isolation techniques. The strain isolated, strain IH-35A, was classified as a member of the genus Brevibacterium. The results of growth and enzyme studies are consistent with degradation of CHAM via cyclohexanone (CHnone), 6-hexanolactone, 6-hydroxyhexanoate, and adipate. Cell extracts obtained from this strain grown on CHAM contained CHAM oxidase, and the model for CHAM oxidation by this enzyme was similar to the model for deamino oxidation of amine by amine oxidase.

Biodegradation, Environmental↗
PubMed1999

Cloning and expression of the N,N-dimethylformamidase gene from Alcaligenes sp. strain KUFA-1.

N,N-Dimethylformamidase (DMFase) from Alcaligenes sp. strain KUFA-1, a bacterium that can grow on N,N-dimethylformamide (DMF) as the sole carbon and nitrogen source, catalyzes the first step of the DMF degradation. The DMFase gene dmfA1A2 was cloned in Escherichia coli, and its nucleotides were sequenced. The deduced amino acid sequence of the enzyme consisted of two alpha- and two beta-subunits with 132 and 762 amino acids, respectively, and had little similarity to sequences in protein databases, including various amidases. The protein may be a new kind of amidase. DMFase activity was detected in E. coli cells transformed with an expression plasmid of the cloned DMFase gene. The properties of recombinant DMFase purified from E. coli were identical to those of Alcaligenes DMFase.

Alcaligenes↗
PubMed1999

A clinicopathological study of lung cancer patients with occupational exposure to chrysotile asbestos fibers.

OBJECTIVE: To summarize the features of asbestos-related lung cancer. PATIENTS: Thirty-one lung cancer patients with occupational exposure to chrysotile asbestos fibers. They worked or had worked in one asbestos factory or its subcontracters. RESULT: All patients were male with mean age of 60.6 when diagnosed, and all except one were current or ex-'heavy' smokers. Histological types were fairly evenly divided into adeno-, squamous and small cell carcinoma and 24 (78%) of patients showed 'peripheral type' lung cancers. Regarding clinical stages, 20 patients (65%) were classified as III or IV (advanced stage). Tumor shadow(s) was detected on chest X-ray in 22 patients (71%), and in 5 patients with 'negative' chest X-ray, chest CT was necessary to recognize a primary tumor. Seventeen patients (55%) did not undergo periodical check-ups. CONCLUSION: Occupational asbestos exposure is interpreted as one of the important risks for lung cancer and frequent and accurate observation is necessary.

Adult↗
PubMed1998

Estimation of regional lung function in interstitial pulmonary disease using 99mTc-technegas and 99mTc-macroaggregated albumin single-photon emission tomography.

For quantitative evaluation of the regional lung function in patients with interstitial pulmonary disease (IP) in the sitting position, 99mTc-Technegas and 99mTc-macroaggregated albumin (MAA) single-photon emission tomography (SPET) studies were performed in 12 healthy controls (HC) and 42 IP patients. Four transverse images were prepared from the data obtained and designated as slices no. 1-4 from the top downward. Regions of interest (ROIs) were determined in the anterior and posterior parts of the lung in each slice, and the ratio of the count per voxel in the ROIs to the count in the entire lung was calculated as the regional Technegas index (T). The regional perfusion index (Q) was calculated by a similar procedure using the data of 99mTc-MAA SPET. The ratios between T and Q (T/Q) in the anterior and posterior regions of the lung, and the ratios of T and Q between the anterior and posterior regions of the lung (Tp/Ta and Qp/Qa) were examined. In the HC group, T/Q decreased but Tp/Ta and Qp/Qa increased from the upper to the lower lung fields. When IP patients were classified into (I) those in whom T/Q decreased from the upper to the lower lung fields, (II) those in whom it was similar in all slices, (III) those in whom it increased from slice 3 to slice 4, and (IV) those in whom it increased from slice 2 to slices 3 and 4, this classification was more closely correlated with %VC than with %DLCO or PaO2. When the patients were classified according to Tp/Ta and Qp/Qa into (A) those in whom the values were greater in the lower than the upper lung field, (B) those in whom the values were similar in all slices, and (C) those in whom the values were smaller in lower than in upper lung fields, categories B and C were observed frequently even in patients whose %VC was in the normal range. This method is considered to be an effective means to evaluate the progression and pathology of IP and to detect early impairment of lung function.

Adult↗
PubMed1998

Effect of plasma colloid osmotic pressure on intraocular pressure during haemodialysis.

BACKGROUND: In a previous case report, it was shown that an increase in plasma colloid osmotic pressure induced by the removal of fluid during haemodialysis was instrumental in decreasing intraocular pressure. The relation between changes in intraocular pressure, plasma osmolarity, plasma colloid osmotic pressure, and body weight before and after haemodialysis is evaluated. METHODS: Intraocular pressure, plasma osmolarity, plasma colloid osmotic pressure, and body weight were evaluated before and after haemodialysis in 36 patients. RESULTS: Intraocular pressure and plasma osmolarity both decreased significantly after haemodialysis (p < 0.0001). Plasma colloid osmotic pressure increased significantly after haemodialysis (p < 0.0001). Body weight decreased significantly because of the removal of fluid during haemodialysis (p < 0.0001). No significant correlation was found between the change in intraocular pressure and that in plasma osmolarity (r = -0.206, p = 0.2297), whereas the change in intraocular pressure was correlated with the change in plasma colloid osmotic pressure (r = -0.510, p = 0.0012) and the change in body weight (r = 0.534, p = 0.0006). A significant correlation was found between the change in plasma colloid osmotic pressure and that in body weight (r = -0.756, p < 0.0001). CONCLUSION: The change in intraocular pressure was inversely correlated with the increase in plasma colloid osmotic pressure caused by the removal of fluid during haemodialysis.

Adult↗
PubMed1998

[Energy expenditure in patients with pulmonary emphysema].

We evaluated resting energy expenditure (REE) using canopy mode indirect calorimetry in 21 ambulatory, clinically stable outpatients with pulmonary emphysema (age: 69.3 +/- 8.4, %IBW: 79.3 +/- 12.5, FEV1: 0.98 +/- 0.36) and compared it with that of a 14 age-matched healthy controls (age: 71.1 +/- 6.0, %IBW: 94.5 +/- 13.4). We also compared REE in malnourished patients (%IBW < 90; 73.0 +/- 7.6, N = 14) and normonourished patients (%IBW > or = 90; 92.0 +/- 5.6, N = 7). We examined the relation ship between %REE (REE/REEpred. x 100) and measurements of lung function tests in 21 emphysema patients using single regression analysis. The REE of the patient group was significantly higher than that of the control group (%REE; 115.9 +/- 12.0 vs 86.5 +/- 8.7, p < 0.01). The REE of the malnourished patient subgroup was significantly higher than that of the normonourished patient subgroup (%REE; 121.9 +/- 7.9 vs 109.9 +/- 9.2, p < 0.01). There were no significant differences in FEV1(L), RV/TLC(%), TLC(pred.%) or DLco/VA (pred.%) between the two patient subgroups. The REE of the normonourished subgroup was significantly higher than that of control group (%REE; 109.1 +/- 9.2 vs 86.5 +/- 8.7, p < 0.01). There were significant relations hips among %REE and FEV1, %FVC, FEV1% G, %DLco/VA and RV/TLC (p < .05). These findings suggest that elevated REE may have a significant relation ship with abnormal lung function, and that elevated REE may be a cause of malnutrition in clinically stable patients with pulmonary emphysema.

Aged↗
PubMed1997

Expression of human islet amyloid polypeptide/amylin impairs insulin secretion in mouse pancreatic beta cells.

Non-insulin-dependent diabetes mellitus (NIDDM) is associated histopathologically with islet amyloid deposits of which a major component is islet amyloid polypeptide (IAPP)/amylin. We examined whether endogenous IAPP controls insulin secretion via a local effect within pancreatic islets and whether overexpression of this peptide contributes to pancreatic beta-cell dysfunction in this disease. Transgenic mice expressing human IAPP in pancreatic beta cell were used in this study. Human IAPP expression did not influence the mouse proinsulin mRNA level and insulin content. Glucose-induced insulin secretion was decreased in the isolated pancreatic islets of transgenic mice. MIN6, a glucose-responsive pancreatic beta-cell line, was transfected with human IAPP cDNA by a lipofectin method. Human IAPP expression was confirmed by RNA blot and immunohistochemical analysis. In two transfectants expressing the largest amount of human IAPP, insulin secretion was increased in response to glucose stimulation; however, the magnitude of the insulin response in cells transfected with human IAPP was smaller than in control clones. Insulin content was not influenced by the expression. We conclude that endogenous IAPP inhibits insulin secretion via an autocrine effect within pancreatic islets, and that the impaired insulin secretion in this disease may be partly caused by overexpression of IAPP.

Amyloid↗
PubMed1997

Structure and expression of the human SM22alpha gene, assignment of the gene to chromosome 11, and repression of the promoter activity by cytosine DNA methylation.

To investigate the molecular mechanisms that control expression of smooth muscle cell (SMC) differentiation genes, we have isolated the human SM22a gene, which is composed of five exons and four introns, spanning an approximately 6-kilobase (kb) genomic DNA at chromosome region 11q23.2. Expression of the SM22a messenger RNA was detected in serum-stimulated cell cultures including SMC, undifferentiated skeletal muscle-lineage cells, and fibroblasts, and it was down-regulated in SMC of balloon-injured atheromatous human vessels. A major transcription start site of the SM22alpha gene is located at 75 base-pairs (bp) upstream of the ATG start codon. Analysis of the 2.6 kb 5'-upstream sequence demonstrated that two CArG/SRF-boxes and two GC-box/Sp1-binding sites were present at bp -147 and -274, and at bp -233 and -1635, respectively. The nucleotide sequences of the two CArG/SRF-boxes and the proximal GC-box/Sp1 binding site are 100% conserved with those of the murine SM22alpha genes [Solway, J., Seltzer, J., Samaha, F.F., Kim, S., Alger, L.E., Niu, Q., Morriesey, E.E., Ip, H.S., and Parmacek, M.S. (1995) J. Biol. Chem. 270, 13460-13469; Kemp, P.R., Osbourn, J.K., Grainger, D.J., and Metcalf, C. (1995) Biochem. J. 310, 1037-1043]. Cell transfection assays using a luciferase reporter gene construct containing the 455-bp 5'-flanking region (positions -26 to -480) showed that methylation of the CpG dinucleotides within this segment reduces its transcriptional activity. The results imply a novel mechanism for transcriptional control of the SMC differentiation-specific gene promoter.

Amino Acid Sequence↗
PubMed1997

Airway inflammation in COPD assessed by sputum levels of interleukin-8.

STUDY OBJECTIVE: To assess the characteristics of airway inflammation in patients with COPD. METHODS: We measured the sputum concentration of interleukin-8 (IL-8), a chemokine involved in the migration and activation of neutrophils and eosinophils. We also measured myeloperoxidase (MPO) as a parameter of neutrophil activity and eosinophil cationic protein (ECP) as a parameter of eosinophil activity. Spontaneous sputum samples were obtained from 33 patients with stable COPD and 30 patients with asthma. Induced sputum samples were obtained from 12 normal control subjects. RESULTS: The sputum concentration of IL-8 was significantly higher in the patients with COPD than in the patients with asthma or in the control subjects (p<0.0001). Concentrations of MPO and ECP were significantly higher in the patients with COPD than in the control subjects but did not differ significantly between the patients with COPD and those with asthma. In the patients with COPD, the sputum concentration of IL-8 was significantly correlated with the concentration of MPO (r=0.55, p<0.001) and of ECP (r=0.53, p<0.01). The sputum concentration of IL-8 was negatively correlated with FEV1/FVC (r=-0.78, p<0.0001) in the COPD group. CONCLUSIONS: Results suggest the activation of both neutrophils and eosinophils in the airways of patients with COPD. It appears that IL-8 plays a primary role in this activation. The sputum concentration of IL-8 appeared to be closely associated with the degree of airflow obstruction in patients with COPD and may serve as a marker in evaluating the severity of airway inflammation, which is a risk factor for COPD.

Adult↗
PubMed1997

[Cytokine producing ability of peripheral blood mononuclear cells in the clinical course of pulmonary tuberculosis].

Interferon-gamma (IFN-gamma) and interleukin-10 (IL-10)-producing ability of peripheral blood plastic-dish adherent cells and non-adherent cells obtained from patients with active pulmonary tuberculosis (N = 17) and healthy controls (N = 14) upon stimulation with purified protein derivatives (PPD) were assessed. Adherent cells and non-adherent cells were obtained two times from each patient with active pulmonary tuberculosis without any underlying diseases, on admission before the initiation of administering anti-tuberculous drugs and 2 months later from the negative conversion of Mycobacterium tuberculosis in sputum culture. ELISA was performed to measure IFN-gamma and IL-10 levels in culture media of adherent cells and non-adherent cells stimulated with PPD. IFN-gamma levels produced by non-adherent cells on admission were significantly higher than that of healthy controls (p < 0.001). Elevated IFN-gamma levels on admission was reduced after treatment for tuberculosis (p < 0.03), but still remained higher than that in healthy controls. IL-10 levels of non-adherent cells of patients were lower than those of healthy controls, although the difference was not significant. IL-10 levels produced by non-adherent cells on admission correlated with the time needed for negative conversion of bacilli in sputum culture (p < 0.05). IL-10 level produced by adherent cells from nutritionally normal patients were significantly higher than that of healthy controls (p < 0.05), and elevated IL-10 level was significantly reduced after therapy (p < 0.05). In the normonourished patients, the time needed for negative conversion of the bacilli in sputum culture of patients kept higher level of IL-10 of non-adherent cells (N = 5) was significantly longer than that of patients reduced IL-10 level after therapy. These results suggest that IL-10 produced by monocytes may diminish the TH1 responses of patients with pulmonary tuberculosis.

Acute Disease↗
PubMed1997

[A case of Mycobacterium intracellulare infection associated with sinobronchial syndrome].

The patient was 71-year-old male with a history of sinobronchial syndrome since 8 years ago. He has been suffering from cough, sputum and upper abdominal discomfort since January 1994. He was diagnosed as an early gastric cancer by endoscopy, and his chest X-ray film showed an infiltrative shadow in the right upper lung field. A smear of the sputum specimen was positive for acid fast bacilli, which were later identified as Mycobacterium intracellulare. In this case, before the Mycobacterium intracellulare infection, it was confirmed that his mucociliary transport was severely impaired by using aerosol inhalation cine-scintigraphy. This case suggests that an impairment of the local defence mechanisms may play an important role in the pathogenesis of Mycobacterium intracellulare infection.

Aged↗