Biomedical subjects

T Takemoto

Publications and source records attributed to T Takemoto.

At least 37 records · Page 2Linked to original sources

PubMed2000

Malignant peripheral nerve sheath tumor arising in benign ancient schwannoma: a case report with an immunohistochemical study.

A rare example of malignant transformation in an ancient schwannoma arising in the right side of the neck of a 51-year-old man without any clinical manifestations suggesting neurofibromatosis is described. The tumor, approximately 4 cm at its largest dimension, was well circumscribed and had a direct connection with the sympathetic nerve. Microscopically, the central portion of the tumor showed features of ancient schwannoma characterized by extensive hyalinization with cystic degeneration, scattered spindle cells with hyperchromatic and tapered nuclei, and some symplastic changes. However, predominantly in the outer portion, a proliferation of spindle-shaped cells with enlarged nuclei was present. The nuclei of these cells showed irregular contours, coarse granular chromatin texture, and conspicuous nucleoli. Mitotic figures and small necrotic foci with scattered apoptotic bodies were also seen. Immunohistochemically, S-100 protein was almost negative in areas consisting of overtly atypical cells where the mitotic index evaluated with MIB-1 antibody was 30.5%. In contrast, S-100-positive bland spindle cells were scattered in an extensively hyalinized area with a labeling index less than 3%. P53 protein was strongly positive in atypical spindle cells. Although it is a very uncommon event, definite nuclear atypia, frequent mitotic figures, and the existence of small necrotic foci should be recognized as indicating a diagnosis of malignant degeneration of benign schwannoma. Immunohistochemistry would be useful as an ancillary technique in such a setting.

Biomarkers, Tumor↗

PubMed2000

Knowledge and attitudes toward AIDS among female college students in Nagasaki, Japan.

This study assesses knowledge and attitudes concerning HIV infection and individuals with AIDS among 383 female students attending colleges in Nagasaki, Japan. A structured questionnaire containing questions concerning knowledge about AIDS, sources of information, beliefs and attitudes toward people with HIV/AIDS was administered during sessions set up for that purpose. The mean age of participants was 18.8 +/- 0.8 years (+/- SD). The main source of information for AIDS awareness as reported by the students was the mass media. Good knowledge about AIDS was positively associated with ease of acceptance of living in the same house with a person diagnosed with AIDS [odds ratio (OR): 1.90; 95% confidence interval (CI): 1.07-3.38]. However, residing at home (OR: 0.64; 95% CI: 0.42-0.98) and involvement in nurse education programmes (OR: 0.59; 95% CI: 0.37-0.95) showed a negative association. Students demonstrated a high level of knowledge concerning AIDS and HIV, but had considerable misconceptions and prejudices about people having HIV/AIDS. Our results suggest that a more appropriate education programme in colleges in Japan may be necessary to reduce the discrepancy between general knowledge and desirable attitude regarding HIV/AIDS.

Acquired Immunodeficiency Syndrome↗

PubMed2000

Demographic and reproductive factors for high seroprevalence of Chlamydia trachomatis among pregnant women in Japan.

In order to elucidate demographic and reproductive factors associated with Chlamydia trachomatis seropositivity, serological screening and questionnaire survey were conducted on pregnant women in Nagasaki Prefecture, Japan. Serum samples were taken from 1718 pregnant women between September and December, 1996, at the cooperative obstetric hospitals and clinics, and tested for the presence of antibodies to C. trachomatis using the enzyme immunoassay. A questionnaire was administered on a sub-sample (n -409), among whom 85 (20.8%) were seropositive. A multiple logistic analysis revealed that four characteristics showed a significant association with the seropositivity: (i) experience of premarital pregnancy, (ii) non use of condoms, (iii) short duration of education, and (iv) more frequent induced abortion. The unsafe sexual behavior of young people lacking proper knowledge of how to prevent STD is the most important intervention target for control of the C. trachomatis epidemic in Japan.

Abortion, Induced↗

PubMed2000

Adherence of Bacteroides forsythus to host cells.

The adherence characteristics of Bacteroides forsythus to host cells, was examined. Four laboratory strains and twelve clinical isolates of B. forsythus were used. All strains demonstrated different haemagglutination activities. The haemagglutination of B. forsythus was inhibited strongly by amino acids such as L-arginine, L-histidine, L-lysine and L-alanine. The adherence to polymorphonuclear leucocytes (PMNL) was weak except for B. forsythus ATCC 43037 and OMZ 408. The adherence of these strains was inhibited by L-histidine and L-arginine, and was facilitated by trypsin (0.1 mg/ml) treatment of polymorphonucleocytes. B. forsythus strains showed varied adherence to fibroblasts. It is suggested that the adherence of B. forsythus to host cells is mediated by a factor which is sensitive against some amino acids, and altered by trypsin-like enzymes.

Amino Acids↗

PubMed1999

Characterization of the human dihydropyrimidinase-related protein 2 (DRP-2) gene.

The genes within the dihydropyrimidinase-related protein (DRP) family, were originally identified in humans by their homology to dihydropyrimidinase (DHP). Four members of this gene family, DRP-1, -2, -3 and -4, are expressed mainly in the fetal and neonatal brains of mammals and chickens, and have been implicated as intracellular signal transducers in the development of the nervous system. We isolated the human DRP-2 gene, and determined its transcriptional start site and exon/intron organization. The gene spanned more than 62 kb, and contained 14 exons with lengths ranging from 62 bp to 2606 bp. The transcriptional start site was determined by an RNase protection assay and 5' rapid amplification of cDNA ends (RACE), and a highly GC-rich promoter was identified that contained possible regulatory elements such as a TATA box, CAAT box and three GC boxes. Comparison of the phase and position of intron insertions within the human DRP-2 gene with those within DRP-1, DHP and two Caenorhabditis elegans DRP/DHP homologs, indicated that DRPs are more conserved in their exon/intron organization than DHP.

Amidohydrolases↗

PubMed1999

Knowledge, risk perception of AIDS and reported sexual behaviour among students in secondary schools and colleges in Tanzania.

A questionnaire survey was carried out among 1041 students in secondary schools and colleges in Dar-es-Salaam, Tanzania to evaluate the relationship between HIV-risky sexual behaviour and anti-condom bias, as well as with AIDS-related information, knowledge, perceptions and attitudes. Self-reportedly, 54% of students (75% of the boys and 40% of the girls) were sexually active, 39% had a regular sexual partner and 13% had multiple partners in the previous year. The condom use rate was higher than previous reports. However, 30% of sexually active respondents did not always use condoms (Risk-1 behaviour) and 35% of those with multiple partners in the previous year did not always use condoms (Risk-2 behaviour). Multiple logistic regression analyses indicated that 'sex partner hates condom' had association with both Risk-1 behaviour (OR 2.47; 95% CI 1.58-3.85) and Risk-2 behaviour (OR 2.47; 95% CI 1.10-5.48). 'Use of condom prevents HIV infection' also had association with both Risk-1 behaviour (OR 2.09; 95% CI 1.19-3.67) and Risk-2 behaviour (OR 3.73; 95% CI 1.28-11.03). Students engaging in risky behaviour were aware of the risk, even though they failed to change their behaviour. Reasons for the AIDS epidemic among Tanzanian students and the importance of more effective AIDS education are also discussed.

Adolescent↗

PubMed1999

Significance of anaerobic preincubation of Helicobacter pylori for measuring metronidazole susceptibility by the Etest.

The Etest is widely used for measuring the susceptibility of Helicobacter pylori to metronidazole. By using 55 H. pylori isolates from 55 patients and a standard H. pylori strain, NCTC11637, we compared metronidazole susceptibility results obtained from the Etest with or without anaerobic preincubation to those obtained from the agar dilution method. Mueller Hinton agar plates supplemented with 5% horse blood were used for both methods. For the Etest, plates were incubated for 72 hr at 35 C under microaerophilic conditions after 0-, 4- or 24-hr periods of anaerobic preincubation. For the agar dilution method, the plates were incubated at the same microaerophilic conditions as those for the Etest. Without anaerobic preincubation for the Etest, 39 of the 56 (70%) H. pylori isolates were categorized as resistant to metronidazole (minimal inhibitory concentration>8 mg/liter), whereas only one of the 56 (1.8%) isolates was resistant according to the agar dilution method. The resistant and susceptible agreement rate was 32%. Four-hour anaerobic preincubation did not alter the readings of the Etest significantly. However, when the Etest was performed with 24-hr anaerobic preincubation, the number of isolates categorized as resistant was reduced to six (11%), improving the agreement rate to 91%. For measuring the metronidazole susceptibility of H. pylori by the Etest, 24-hr anaerobic preincubation is necessary to agree with the results obtained by the agar dilution test.

Anaerobiosis↗

PubMed1999

Prevalence of joint pain is higher among women in rural Japan than urban Japanese-American women in Hawaii.

OBJECTIVE: Environmental factors such as farming contribute to the frequency of joint symptoms. The purpose of this study is to explore the possible role of environment (lifestyle), by comparing the prevalence of joint pain between Japanese in a rural farming district in Japan and in urban Hawaii. SUBJECTS AND METHODS: Current or previous pain at specific joints was surveyed among 222 women in rural Japan and 638 Japanese women in urban Hawaii aged 60-79. The age adjusted prevalence was compared using logistic regression. RESULTS: The prevalence of pain at one or more joints was approximately 70% in Japan and 50% in Hawaii. The prevalence of knee pain in Japan ranged from 36% at ages 60-69 years to 53% at 70-79 years (mean 41%), whereas knee pain affected only 20% of women in Hawaii in both age groups. The odds ratio (and 95% CI) was 3.2 (2.1, 4.8) for knee pain, and 4.0 (2.2, 7.4) for mid-back pain in Japan, compared with Hawaii. Pain was also significantly more common in Japan at the shoulder, elbow, and ankle, but not at other joints. Women in Japan were shorter and weighed less than in Hawaii. Adjustment for body mass index increased the odds ratios to 4.4 (2.9, 6.8) for knee, and 4.5 (2.4, 8.5) for mid-back pain. CONCLUSION: Although the potential influence of cultural factors or other sources of bias cannot be ruled out, the large differences in the prevalence of pain at specific joints suggest that environmental factors are probably responsible, because both populations are of similar genetic stock.

Aged↗

PubMed1999

Relationship of intra-abdominal adiposity and peripheral fat distribution to lipid metabolism in an island population in western Japan: gender differences and effect of menopause.

Intra-abdominal adiposity is associated with unfavorable serum lipid profiles (high total cholesterol or triacylglycerol, and low high-density lipoprotein cholesterol) in obese people. However, the relation in mainly nonobese Japanese population is not well known. We examined the relationship between intra-abdominal adiposity measured by ultrasonography and body fat distribution with serum lipids in Japanese people living in an island in western Japan. Mainly nonobese healthy individuals (98 men, 72 premenopausal and 182 postmenopausal women) aged between 33 and 69 years were examined. Accumulation of intra-abdominal fat (Pmax) and abdominal subcutaneous fat (Smin) was measured by ultrasonography. We also measured triceps and subscapular skinfold thicknesses, and the concentrations of total cholesterol, triacylglycerol and high-density lipoprotein (HDL) cholesterol. In men and postmenopausal women, Pmax correlated significantly with the majority of serum lipids after adjusting for age, body mass index and smoking habit. In premenopausal women, Pmax correlated significantly with only total cholesterol, but marginally with triacylglycerol and HDL/total cholesterol ratio after adjustment. Our findings suggest that intra-abdominal adiposity is related to unfavorable lipid profile in both genders among mainly nonobese Japanese population.

Abdomen↗

PubMed1999

Daily response of blood pressure to day-to-day variation of urinary sodium to potassium ratio.

The relationship between blood pressure and urinary sodium-to-potassium (Na/K) ratio was assessed in eight healthy men, none of whom used antihypertensive medications. Blood pressure and urinary sodium and potassium concentrations were measured for 11 to 33 days without any dietary restriction. For two of the eight subjects, the urinary Na/K ratio significantly correlated with systolic blood pressure (r=0.70 and 0.45, respectively), and in one of the two subjects, the urinary ratio also positively correlated with diastolic blood pressure (r=0.72). In the others, no relationship between the ratio and blood pressure was observed (r=-0.24 to 0.26). The results indicate that, in some individuals, the daily variation of urinary Na/K ratio is closely correlated with day-to-day changes in blood pressure level, and suggest that the urinary Na/K ratio is useful in the management of the daily sodium and potassium intake balance of hypertensive patients who need to restrict salt intake.

Adult↗

PubMed1999

[An empirical study on the increase of mild alcoholics in Japan].

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Adult↗

PubMed1998

Different mechanisms of thioredoxin in its reduced and oxidized forms in defense against hydrogen peroxide in Escherichia coli.

The present experiments were done to elucidate the roles of thioredoxin and thioredoxin reductase system in defense against hydrogen peroxide (H2O2) in Escherichia coli. The thioredoxin-deficient mutant (trxA) was more sensitive to H2O2 than was the wild-type strain, when challenged in the stationary and exponentially growing phase. Thioredoxin reductase-deficient mutant (trxB) in the stationary phase also exhibited increased sensitivity, compared with the wild-type strain. These results indicated that reduced form of thioredoxin is required for defense against H2O2, possibly by scavenging radicals generated in the cells. In contrast, the trxB mutant in the growing phase had higher survival after exposure to H2O2 than the wild-type strain. The acquirement of resistance related to increased capacity for removing H2O2 in the trxB mutant and was not observed in a catalase-negative background. Furthermore, enhanced expression of the katG :: lacZ gene occurred in the mutant. Therefore, it was concluded that oxidized form of thioredoxin confers H2O2 resistance on E. coli cells by increasing activity to remove H2O2, which was brought about by enhanced induction of the katG-coded catalase/hydroperoxidase I at the transcriptional level. In addition, this resistance to H2O2 correlated well with reduced amount of DNA damage caused by H2O2, determined by the induction level of the recA :: lacZ fusion gene after treatment with H2O2.

Acatalasia↗

PubMed1998

Differential effects of various growth factors and cytokines on the syntheses of DNA, type I collagen, laminin, fibronectin, osteonectin/secreted protein, acidic and rich in cysteine (SPARC), and alkaline phosphatase by human pulp cells in culture.

The purpose of this study is to differentiate roles of several growth factors and cytokines in proliferation and differentiation of pulp cells during development and repair. In human pulp cell cultures, laminin and type I collagen levels per cell remained almost constant during the whole culture period (22 days). On the other hand, secreted protein, acidic and rich in cysteine (SPARC/osteonectin) and alkaline phosphatase (ALPase) levels markedly increased after the cultures reached confluence. Laminin and type I collagen, as well as fibronectin, stimulated the spreading of pulp cells within 1 h. Adding transforming growth factor-beta (TGF-beta) decreased laminin and ALPase levels, whereas it increased SPARC and fibronectin levels 3- to 10-fold. Western and Northern blots showed that TGF-beta enhanced SPARC synthesis at the protein and mRNA levels. Basic fibroblast growth factor (bFGF) decreased type I collagen, laminin, SPARC, and ALPase levels without changing the fibronectin level. Platelet-derived growth factor (PDGF) selectively decreased laminin, SPARC, and ALPase levels. Epidermal growth factor (EGF) also decreased SPARC and ALPase levels. Tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) decreased type I collagen and laminin levels, and abolished SPARC and ALPase syntheses. Of these peptides, bFGF and PDGF showed the greatest stimulation of [3H]thymidine incorporation into DNA. TGF-beta, EGF, and TNF-alpha had less effect on DNA synthesis, whereas IL-1beta inhibited DNA synthesis. These findings demonstrated that TGF-beta, bFGF, EGF, PDGF, TNF-alpha, and IL-1beta have characteristically different patterns of actions on DNA, laminin, type I collagen, fibronectin, ALPase, and SPARC syntheses by pulp cells.

Alkaline Phosphatase↗

PubMed1998

3'-blocking damage of DNA as a mutagenic lesion caused by hydrogen peroxide in Escherichia coli.

Ionizing radiation and hydrogen peroxide (H2O2) produce many types of oxidative DNA damage such as strand breaks, apurinic/apyrimidinic (AP) sites, base modifications and 3'-blocking damage such as 3'-phosphoglycolated and 3'-phosphorylated termini. AP sites and 3'-blocking damage are repairable by exonuclease III and endonuclease IV in Escherichia coli. XthA-nfo double mutants of E. coli, which are deficient in exonuclease III and endonuclease IV, were highly sensitive to lethal and mutagenic effects of H2O2, compared with the wild-type strains. The pNT180 and pNT186 plasmids containing wild-type nfo and mutant nfo-186 gene, respectively, were introduced into the xthA-nfo mutant. The nfo-186 gene product, Nfo186, retained normal AP endonuclease activity but could not remove 3'-blocking damage from DNA. The pNT180 corrected the sensitivity of the xthA-nfo mutant to lethal and mutagenic effects of H2O2. On the other hand, the pNT186 did not have any complementation effects. From these results it was concluded that 3'-blocking damage rather than an AP site is the primary lesion responsible for both lethal and mutagenic effects of H2O2.

DNA Damage↗

PubMed1998

Falls among community-dwelling elderly in Japan.

Japanese have a lower incidence of hip fracture than Caucasians despite having lower bone mass. Hip fractures usually occur after a fall, and differing incidence rates of falls might explain the observed differences in hip fracture rates. To explore this hypothesis, we studied falls and related conditions among 1534 (624 men, 910 women) community-dwelling people aged 65 years and over in Japan and compared the prevalence of falls to Japanese-Americans living in Hawaii and to published studies of Caucasians. In Japan, 9% of the men and 19% of the women reported one or more falls during the past year. The prevalence of falls increased with age in both genders and was greater among women compared with men. In logistic regression models, having musculoskeletal disease, physical disability or limited activity increased the risk of falls by two to four times in both genders. Most fallers (92%) reported fear of future falls, and about one third of fallers reported that they went out less often as a result of their falls. Compared with native Japanese, the age-standardized prevalence of falls among Japanese-Americans was similar but about twice as high for Caucasians, which may explain the lower hip fracture risk of Japanese.

Accidental Falls↗

PubMed1997

Cellular immuno-competence of infected root canal contents in pathogenesis of periapical lesions.

The soluble fractions of infected root canal contents (IRCC) were collected from about 300 human extracted teeth and examined for the presence of mononuclear cell (MNC) chemotaxis and cellular immunocompetence. IRCC showed remarkable chemotactic activity for polymorphonuclear leukocytes but a weak activity for MNC. However, generation of intrinsic MNC chemotaxis and induction of cellular immunity were confirmed in rats given repeated injections of IRCC.

Animals↗

PubMed1997

Past, present and future of gastroenterology in Japan: the 100th anniversary of the Japanese Society of Gastroenterology in 1998.

The Japanese Society of Gastroenterology (JSGE) will celebrate the centenary of its foundation in 1998. A variety of plans and projects are being prepared by the JSGE centennial celebration committee. In this article, the history of the JSGE is briefly described, and several projects, including the international symposium currently being planned, are introduced. The future prospects of our Society will also be described.

Anniversaries and Special Events↗

PubMed1997

Characterization of Bacteroides forsythus isolates.

Fifteen Bacteroides forsythus strains freshly isolated from patients with periodontitis were used together with three collection strains and one type strain for characterization of growth on various media; determination of enzymatic profiles, antibiotic susceptibility profiles, 16S rRNA ribotypes, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) outer membrane protein profiles, and pathogenicity; and gas chromatography analysis by using a wound chamber model in rabbits. All strains were stimulated by N-acetylmuramic acid, while one strain needed a further supplement such as yeast extract for optimal growth. All strains showed trypsin-like activity. While 10 different ribotypes were found, the SDS-PAGE profiles revealed similar patterns for all strains. All strains were sensitive to penicillin G (MICs, <0.5 microg/ml), ampicillin (MICs, <1.0 microg/ml), amoxicillin (MICs, <0.38 microg/ml), metronidazole (MICs, <0.005 microg/ml), tetracycline (MICs, <0.19 microg/ml), doxycycline (MICs, 0.05 microg/ml), erythromycin (MICs, <0.4 microg/ml), and clindamycin (MICs, <0.016 microg/ml), while they were less sensitive to ciprofloxacin (MICs, <4 microg/ml). B. forsythus did not cause abscess formation by monoinoculation. B. forsythus coinoculated with Fusobacterium nucleatum ATCC 10953 caused abscess formation in 75% of rabbits, while it caused abscess formation in 100% of rabbits when it was coinoculated with Porphyromonas gingivalis FDC 381. In the case of the latter combination, four of six rabbits died of sepsis after 6 to 7 days, and P. gingivalis and B. forsythus were recovered from the heart blood at a proportion of 10:1. B. forsythus strains were highly virulent and invasive in combination with P. gingivalis.

Abscess↗