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K Kano

Publications and source records attributed to K Kano.

At least 19 recordsLinked to original sources
PubMed1999

Surface characterization and on-line activity measurements of microorganisms by capillary zone electrophoresis.

Capillary zone electrophoresis (CZE) was applied to the electrophoretic characterization for microorganisms. The electrophoretic peaks detected using light scattering phenomena were characteristic of the microorganisms used. The electrophoretic mobility (mu) evaluated by CZE was in good agreement with that obtained by classical electrophoresis of microorganisms. The migration time was reproducible and depended on the ionic strength (I). Analysis of the mu vs. I relationship provided information regarding the charge density and the hardness of the microbial cell surface. The redox enzymatic activity of microorganisms was also evaluated by CZE using a running buffer containing a corresponding substrate and an appropriate exogenous electron acceptor. A decrease in the concentration of the electron acceptor due to microbial activity can be simultaneously monitored during the electrophoretic process without significant modification of the CZE instrument. Effects of some chemical treatments of microbial cells were also studied using this technique.

Bacteria↗
PubMed1999

Influence of grip strength on metacarpal bone mineral density in postmenopausal Japanese women: a cross-sectional study.

Most published studies on the role of muscle strength in the maintenance of bone mineral density (BMD) focused on the relationship between specific muscle groups and adjacent bones, mostly in young and premenopausal women. This study examined the influence of grip strength on BMD of the metacarpal index in postmenopausal Japanese women. Subjects included 1168 postmenopausal women aged 40-70 years. BMD measurement was done with computed X-ray densitometry (CXD) by analyzing X-ray films of the right second metacarpal index. Grip strength was measured in both the dominant and nondominant hands using a squeeze dynamometer. Grip strength (r = 0.2474; P = 0.0001) and age (r = -0.5443; P = 0.0001) significantly correlated positively and negatively, respectively, with BMD. Physical activity (r = 0.1318; P = 0.0001) also correlated positively with BMD. Breastfeeding (r = -0.1658; P = 0.0001), however, correlated negatively with BMD. Subjects with a history of regular physical activity had higher grip strengths and BMD, than those with no physical activity. Adjustment for age, physical activity, calcium intake, BMI, breastfeeding, testing site, and menopausal type indicated a significant (P for trend = 0.0013) positive association of grip strength with BMD. Subjects with stronger grip strengths had a decreased risk for low BMD.

Absorptiometry, Photon↗
PubMed1999

[The critical appraisal of QOL questionnaire for prostate cancer patients].

BACKGROUND: Prostate cancer is a common malignancy that affects Japanese elderly men. Its incidence is increasing, recently, and its treatments are various. The measurement of quality of life (QOL) has become important for the evaluation of and selection of treatments. In Japan, however, there is no standard way of measuring QOL for prostate cancer patients, except the Japanese version of the EORTC QOL questionnaire for prostate cancer patients. We examined the validity and feasibility of this translated EORTC QOL questionnaire for prostate cancer patients. METHODS: Sixty-nine prostate cancer patients who were under treatment in 4 hospitals were selected for this study. We applied the content validity, the factorial validity which was analyzed by the oblique principal component cluster analysis, the internal consistency analyzed by the alpha coefficient of Cronbach, the convergent validity which was used GHQ, IPSS and PS as external measures, and the feasibility. RESULTS: This questionnaire showed good internal consistency, as the alpha coefficient was 0.61 to 0.90 in all domains, except for sex life, which was the lowest. This questionnaire was classified into 7 clusters by the oblique principal component cluster analysis. Consequently, the factorial validity was good, except for items regarding sex life. As domains correlate well with external measures except in sex life, the convergent validity was good. It was suggested that only two items were not acceptable in regard to the content validity and the feasibility, and that the translation into Japanese of 2 items was inadequate. CONCLUSIONS: Our study suggests that the Japanese version of the EORTC QOL questionnaire for prostate cancer patients demands improvement for the practical employment in clinical trials, as there is a problem of translation and feasibility.

Aged↗
PubMed1998

Timing of menopause, reproductive years, and bone mineral density: a cross-sectional study of postmenopausal Japanese women.

Age at menopause has been found to be associated positively with bone mineral density, and age at menarche has been found to be associated negatively with bone mineral density. However, there have been few studies on the relations of timing of menopause and length of the reproductive period with bone mineral density. The purpose of this study was to examine the relations of timing of menopause and reproductive years (calculated as age at menopause minus age at menarche) with mineral density of the second metacarpal bone in postmenopausal Japanese women. The study population consisted of 1,035 naturally menopausal women aged 40-70 years who were screened in 1996-1997. Using computed x-ray densitometry, the authors measured bone mineral density by analyzing radiographic films of the right second metacarpal bone. Using the women with early menopause (age < 49 years) as the reference group and adjusting for age, subjects with late menopause were at decreased risk for low bone mineral density (odds ratio (OR) = 0.69, 95% confidence interval (CI) 0.49-0.97). After adjustment for additional covariates (grip strength, physical activity, body mass index, smoking, and calcium intake), the association was unchanged (OR = 0.70, 95% CI 0.50-0.99). Postmenopausal women with more reproductive years (> or = 40 years) were at decreased risk for low bone mineral density compared with those with fewer reproductive years, after adjustment for age (OR = 0.73, 95% CI 0.40-1.30) and potentially confounding factors (OR = 0.76, 95% CI 0.41-1.37); the p-value for trend was not statistically significant. In multiple linear regression analysis, early menopause and fewer reproductive years were independent predictors of low bone mineral density. In this study, postmenopausal Japanese women who had a late menopause and more reproductive years were at decreased risk for low bone mineral density, and may therefore be less prone to osteoporosis.

Adult↗
PubMed1998

Mechanistic study on the roles of a bifidogenetic growth stimulator based on physicochemical characterization.

2-Amino-3-carboxy-1,4-naphthoquinone, discovered as a novel bifidogenetic growth stimulator (BGS), has been characterized by determination of redox and acid-base equilibria, partition properties, and UV-vis and electron spin resonance spectral properties. BGS is proposed to function as an electron transfer mediator from NADH to O2. BGS is reduced by NADH-reduced diaphorase (or related enzymes) and the reduced BGS is reoxidized by autoxidation and a peroxidase-catalyzed reaction. The proposed reaction would spare pyruvate as an important metabolic intermediate, and minimize the cytotoxic effects of H2O2 generated by the autoxidation. Kinetic studies were performed in model enzymatic systems using 2-methyl-1,4-naphthoquinone (VK3) as a reference compound with a very weak growth-stimulating effect. The results support our proposal and reveal the superiority of BGS to VK3 as an electron transfer mediator in the proposed reactions.

Bifidobacterium↗
PubMed1998

Role of the isoprenyl tail of ubiquinone in reaction with respiratory enzymes: studies with bovine heart mitochondrial complex I and Escherichia coli bo-type ubiquinol oxidase.

The hydrophobic isoprene tail of ubiquinone-2 (Q2) exihibits binding specificity in redox reactions with bovine heart mitochondrial complex I (Ohshima, M., Miyoshi, H., Sakamoto, K., Takegami, K., Iwata, J., Kuwabara, K., Iwamura, H., and Yagi, T. (1998) Biochemistry 37, 6436-6445) and the Escherichia coli bo-type ubiquinol oxidase (Sakamoto, K., Miyoshi, H., Takegami, K., Mogi, T., Anraku, Y., and Iwamura, H. (1996) J. Biol. Chem. 271, 29897-29902). To identify the structural factor(s) of the diprenyl tail of Q2 governing the specific interaction with these enzymes, we synthesized a series of novel Q2 analogues in which only one of the structural factors of the diprenyl tail was systematically modified. In bovine complex I, the presence of the methyl branch and the pi-electron system in the first isoprene unit are responsible for high-affinity binding of Q2 to the ubiquinone reduction site, which results in a low Km and kcat values of Q2 reduction. The position of the methyl group in the tail is strictly recognized by the enzyme. In contrast to complex I, in bo-type ubiquinol oxidase, either of the two pi-electron systems in the tail is required for high-affinity binding of Q2H2 to the enzyme, while the presence of the methyl branch and the location of the pi-electron systems are not strictly recognized by the enzyme. We concluded that the role of the ubiquinone tail is not simply the enhancement of the hydrophobicity of the molecule and that molecular recognition of the tail by the quinone redox site differs among the respiratory enzymes.

Animals↗
PubMed1998

The Ras target AF-6 is a substrate of the fam deubiquitinating enzyme.

The Ras target AF-6 has been shown to serve as one of the peripheral components of cell-cell adhesions, and is thought to participate in cell-cell adhesion regulation downstream of Ras. We here purified an AF-6-interacting protein with a molecular mass of approximately 220 kD (p220) to investigate the function of AF-6 at cell-cell adhesions. The peptide sequences of p220 were identical to the amino acid sequences of mouse Fam. Fam is homologous to a deubiquitinating enzyme in Drosophila, the product of the fat facets gene. Recent genetic analyses indicate that the deubiquitinating activity of the fat facets product plays a critical role in controlling the cell fate. We found that Fam accumulated at the cell-cell contact sites of MDCKII cells, but not at free ends of plasma membranes. Fam was partially colocalized with AF-6 and interacted with AF-6 in vivo and in vitro. We also showed that AF-6 was ubiquitinated in intact cells, and that Fam prevented the ubiquitination of AF-6.

Animals↗
PubMed1998

Dihydroheptaprenyl and dihydrodecaprenyl monophosphates induce apoptosis mediated by activation of caspase-3-like protease.

Dolichyl phosphate, an essential carrier lipid in the biosynthesis of N-linked glycoprotein, has been found to induce apoptosis in rat glioma C6 cells and human monoblastic leukemia U937 cells. In the present study, dolichyl phosphate and structurally related compounds were examined regarding their apoptosis-inducing activities in U937 cells. Dihydroheptaprenyl and dihydrodecaprenyl phosphates, of which isoprene units are shorter than that of dolichyl phosphate, induced apoptosis in U937 cells. This phenomenon occurred in a dose- and time-dependent manner, as seen with dolichyl phosphate-induced apoptosis. Derivatives of the same isoprene units of dolichyl phosphate, such as dolichol, dolichal or dolichoic acid, did not induce DNA fragmentation. Farnesyl phosphate and geranylgeranyl phosphate also failed to induce apoptosis. During apoptosis, the caspase family of cysteine proteases play important roles. We observed that apoptosis induced by dihydroprenyl phosphate was mediated by caspase-3-like (CPP32-like) activation but not by caspase-1-like (ICE-like) activation. This caspase-3-like activation was inhibited by a specific inhibitor of caspase-3, DEVD-CHO, but not by an caspase-1 inhibitor YVAD-CHO. We interpret these results to mean that dihydroprenyl phosphates with more than seven isoprene units have apoptosis-inducing activity and that their signal is mediated by caspase-3-like activation.

Apoptosis↗
PubMed1998

DNA cleavage and 8-hydroxydeoxyguanosine formation caused by tamoxifen derivatives in vitro.

DNA damage caused by tamoxifen and its derivatives was examined by estimating the conversion of supercoiled pUC18 plasmid DNA to linear form by means of agarose gel electrophoresis. N-Desmethyltamoxifen induced DNA cleavage and its effect was enhanced by the addition of reducing agents such as dithiothreitol, NADPH and 2-mercaptoethanol. 4-Hydroxytamoxifen itself had little effect, but the cleavage was slightly enhanced by the addition of reducing agents. DNA damage was higher with alpha-hydroxytoremifene than with alpha-hydroxytamoxifen, which had a prominent effect only at high concentration. The cleavage by alpha-hydroxy derivatives were not enhanced by reducing agents. No damage was induced by tamoxifen, toremifene, 3-hydroxytamoxifen or N-desmethyltoremifene. The DNA cleavage by N-desmethyltamoxifen was inhibited by the addition of EDTA, mannitol, sodium azide, methionine, catalase and superoxide dismutase. The formation of 8-hydroxy-2'-deoxyguanosine was also examined with calf thymus DNA in vitro. A slight increase of its level was found with 4-hydroxytamoxifen in the presence of dithiothreitol and also with N-desmethyltamoxifen in the presence of NADPH, but alpha-hydroxytoremifene and alpha-hydroxytamoxifen were ineffective. These experimental data suggest that among metabolites of tamoxifen, N-desmethyltamoxifen and probably also 4-hydroxytamoxifen cause oxidative DNA damage in which redox cycling is involved. The DNA damage by alpha-hydroxytoremifene appears to involve a different mechanism from that by N-desmethyltamoxifen. Tamoxifen and toremifene are possibly metabolized to the forms contributing to DNA damage.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1998

Emergent bronchofiberoptic bronchial occlusion for intractable pneumothorax with severe emphysema.

Emergent bronchofiberoptic bronchial occlusion using fibrin glue and woven polyglycolic acid mesh for persistent pneumothorax with severe emphysema is described. A 74-year-old man who had severe pulmonary dysfunction accompanying chronic emphysema was admitted with a complaint of sudden severe dyspnea. The chest X-ray on admission revealed collapse of the right lung. The patient was placed on a mechanical ventilator because of acute respiratory failure. In spite of continuous suction through a chest drainage tube, air leakage persisted. On the seventh hospital day, subcutaneous emphysema was apparent in the face and scrotum in addition to the chest. First, a double-lumen catheter was inserted into the right B5 bronchus, and fibrin glue was infused into the drainage bronchus via the double-lumen catheter. However, the procedure failed. Next, a combination of fibrin glue and woven polyglycolic acid mesh which had been cut into small pieces was introduced and pushed into the B5 bronchus using forceps. The air leakage stopped immediately after the administration. This procedure is simple and a minimally invasive method for the treatment of intractable pneumothorax in a compromised patient on a mechanical ventilator.

Aged↗
PubMed1998

Results of a qualitative and field study using the WHOQOL instrument for cancer patients.

The main purpose of the study was to evaluate quality of life (QOL) among cancer patients using the WHOQOL-100 instrument and to see if any significant differences were seen in cancer stages, treatment status and prognosis. This study consisted of two parts; qualitative and quantitative. For the qualitative study, two focus groups were conducted by medical professionals to establish the applicability of the WHOQOL instrument in evaluating the QOL of cancer patients, but most participants were negative about using a generic instrument such as WHOQOL. For the quantitative study, 197 cancer patients (average age 55.86) from eight medical centers using the WHOQOL instrument, in addition to each patient's information sheet filled in by their own physicians, were analyzed. The average overall QOL score was 3.39. There was high reliability (Cronbach's alpha = 0.9685) and a high correlation between the psychological and the environmental domains (r = 0.7021), the physical domain and the level of independence (r = 0.6031) and social relations and the environment (r = 0.6856) and between health conditions perceived by patients and QOL scores. In addition, differences by gender, treatments and cancer sites were also found to be significantly different at the 5% significance level. The results indicated that the WHOQOL core instrument was sensitive enough to evaluate the QOL of cancer patients.

Adult↗
PubMed1998

Effects of glycosaminoglycans on the development of in vitro-matured and -fertilized porcine oocytes to the blastocyst stage in vitro.

We examined the effects of four glycosaminoglycans (GAGs) on the development of in vitro-matured (IVM) and -fertilized (IVF) porcine oocytes to the blastocyst stage. IVM and IVF oocytes were cultured in Whitten's medium supplemented with hyaluronic acid, chondroitin sulfate A, dermatan sulfate, or heparin at 38.5 degrees C in an atmosphere of 5% CO2 in humidified air for up to 6 days. After 2 days in culture, 28-34% of the inseminated oocytes cleaved to the 2- to 8-cell stage, and the GAGs showed no significant effect on development. After 6 days in culture, blastocysts were observed in all groups. The percentage of blastocysts was significantly higher in hyaluronic acid-supplemented medium (14%) than in dermatan sulfate-supplemented (5%), heparin-supplemented (2%), or nonsupplemented (2%) media. In addition, the percentage of blastocysts was significantly higher in chondroitin sulfate A-supplemented medium (11%) than in heparin-supplemented and nonsupplemented media, although the number of blastocysts in chondroitin sulfate A was not significantly different from that in hyaluronic acid- and dermatan sulfate-supplemented media. There were no significant differences in the mean number of nuclei per blastocyst cultured in any group. The effects of hyaluronic acid and chondroitin sulfate A on development to the blastocyst stage was examined at various concentrations. After 6 days in culture, development of IVM and IVF oocytes to the blastocyst stage was best supported in 0.5 mg/ml hyaluronic acid-supplemented (17%) and in 0.1 or 0.5 mg/ml chondroitin sulfate A-supplemented (10% or 9%, respectively) media. It is concluded from these results that hyaluronic acid and chondroitin sulfate A supported the development of porcine oocytes matured and fertilized in vitro to the blastocyst stage.

Animals↗
PubMed1998

Uncommon multisystemic involvement in a case of Henoch-Schönlein purpura.

A case of Henoch-Schönlein purpura (HSP) characterized by several unusual complications is reported. A 10-year-old boy was hospitalized with acute abdomen and developed purpura on the lower extremities after 4 days of hospitalization. He had protein-losing enteropathy, diagnosed by an elevated fecal alpha-1-antitrypsin clearance. The colicky abdominal pain and protein-losing enteropathy subsided after methylprednisolone pulse therapy was administered. He had left hydronephrosis and gall-bladder abnormalities detected by ultrasonography, and purpura nephritis. However, after improvement of these abnormalities, he showed steroid-induced epidural lipomatosis, detected by magnetic resonance imaging, which resolved with steroid reduction. Ultrasonography and magnetic resonance imaging were useful for detecting these uncommon multisystemic involvements in HSP.

Child↗
PubMed1998

Amperometric determination of high-density lipoprotein cholesterol using polyethylene glycol-modified enzymes and a peroxidase-entrapped electrode.

A peroxidase-entrapped and ferrocene-embedded carbon paste (POD-Fc-CP) electrode allows a highly sensitive detection of H2O2 at levels as low as 10 nmol/L with practically no interference by coexisting substances, turbidity or coloration of samples. The electrode was applied to the amperometric determination of high-density lipoprotein (HDL)-cholesterol in a very small volume (1-2 microL) using polyethylene glycol (PEG)-modified cholesterol esterase and cholesterol oxidase without prior precipitation or separation of HDL. PEG-modified enzymes exhibit a selective activity toward HDL-cholesterol in the presence of dextran sulphate and MgCl2 to generate H2O2. The HDL-cholesterol concentrations of human serum samples determined by this method showed a good correlation with those determined by an ordinary spectrophotometric method using PEG-modified enzymes and peroxidase or by a conventional precipitation method.

Cholesterol, HDL↗
PubMed1998

Physical activity and the risk of breast cancer: a case-control study of Japanese women.

A case-control study was conducted in Ibaraki, Japan. Cases were 148 women aged 26-69 diagnosed with breast cancer at Tsukuba University Hospital or Tsukuba Medical Center Hospital between January 1990 and March 1997. Two controls were individually matched to cases by age (within 1 year) and residence (municipalities). A self-administered questionnaire was used to obtain information on physical activity and the effects of potential confounding factors. Conditional logistic regression analysis was used to estimate odds ratios (ORs) and 95 percent confidence intervals (95% CIs). After adjustment for potential confounding factors (height, body mass index (BMI), family history of breast cancer, education, age at menarche, age at first birth, parity, menopausal status), recreational physical activity was associated with a reduced risk of breast cancer (p for trend = 0.005). OR for breast cancer among women who played regular sport or exercise more than 15.3 METs per week was 0.35 (95% CI = 0.17, 0.73), as compared to women with no sport or exercise. The risk of breast cancer was also reduced in women with higher occupational physical activity levels, but it was not significant (p for trend = 0.223). The adjusted OR among the highest quartile level was 0.55 (95% CI = 0.27, 1.12) with the lowest quartile level as reference. Our findings support a protective effect of recreational physical activity on breast cancer in Japanese women.

Adult↗
PubMed1998

Relationship between exercise and bone mineral density among over 5,000 women aged 40 years and above.

An epidemiological survey was conducted to clarify the relationship between bone mineral density(BMD) and exercise at 14 health centers in Ibaraki Prefecture, Japan from September 1994 through March 1995. More than 5,000 women participated in this survey. Second metacarpal BMD was measured by CXD(Computed X-ray Densitometry) method. Information about past history of exercise was obtained by questionnaire. sigma GS/D < 2.3(sigma GS/D: a parameter of BMD) was used to estimate the suspicion of osteoporosis. Data on 5,124 women aged 40 years and above were analyzed. Subjects were categorized into two groups according to the presence(n = 1,687) or absence(n = 3,437) of past history of regular exercise. sigma GS/D values were significantly (p < or = 0.05) higher in women who have had regular exercise in the past than those of the non-exercise group except those aged over 70 years. Ball game, foot sports and gymnastics were the main exercises. When osteoporosis was suspected based on the measurements of bone mineral density, the odds ratio (exercise present/absent) was 0.27 (95% confidence limits: 0.08-0.94), 0.82 (0.65-1.04), 0.78 (0.61-0.99), and 1.25 (0.67-2.35) at 40-49, 50-59, 60-69, and over 70 years, respectively. The results of the present study suggest the beneficial influence of exercise on bone mineral density and its utility for preventing osteoporosis.

Adult↗
PubMed1997

The Ras target AF-6 interacts with ZO-1 and serves as a peripheral component of tight junctions in epithelial cells.

The dynamic rearrangement of cell-cell junctions such as tight junctions and adherens junctions is a critical step in various cellular processes, including establishment of epithelial cell polarity and developmental patterning. Tight junctions are mediated by molecules such as occludin and its associated ZO-1 and ZO-2, and adherens junctions are mediated by adhesion molecules such as cadherin and its associated catenins. The transformation of epithelial cells by activated Ras results in the perturbation of cell-cell contacts. We previously identified the ALL-1 fusion partner from chromosome 6 (AF-6) as a Ras target. AF-6 has the PDZ domain, which is thought to localize AF-6 at the specialized sites of plasma membranes such as cell-cell contact sites. We investigated roles of Ras and AF-6 in the regulation of cell-cell contacts and found that AF-6 accumulated at the cell-cell contact sites of polarized MDCKII epithelial cells and had a distribution similar to that of ZO-1 but somewhat different from those of catenins. Immunoelectron microscopy revealed a close association between AF-6 and ZO-1 at the tight junctions of MDCKII cells. Native and recombinant AF-6 interacted with ZO-1 in vitro. ZO-1 interacted with the Ras-binding domain of AF-6, and this interaction was inhibited by activated Ras. AF-6 accumulated with ZO-1 at the cell-cell contact sites in cells lacking tight junctions such as Rat1 fibroblasts and PC12 rat pheochromocytoma cells. The overexpression of activated Ras in Rat1 cells resulted in the perturbation of cell-cell contacts, followed by a decrease of the accumulation of AF-6 and ZO-1 at the cell surface. These results indicate that AF-6 serves as one of the peripheral components of tight junctions in epithelial cells and cell-cell adhesions in nonepithelial cells, and that AF-6 may participate in the regulation of cell-cell contacts, including tight junctions, via direct interaction with ZO-1 downstream of Ras.

Animals↗