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Biomedical subjects

T Hayashi

Publications and source records attributed to T Hayashi.

At least 127 records · Page 7Linked to original sources
PubMed2003

Quantitative trait loci analysis for growth and carcass traits in a Meishan x Duroc F2 resource population.

We constructed a pig F2 resource population by crossing a Meishan sow and a Duroc boar to locate economically important trait loci. The F2 generation was composed of 865 animals (450 males and 415 females) from four F1 males and 24 F1 females and was genotyped for 180 informative microsatellite markers spanning 2,263.6 cM of the whole pig genome. Results of the genome scan showed evidence for significant quantitative trait loci (<1% genomewise error rate) affecting weight at 30 d and average daily gain on Sus scrofa chromosome (SSC) 6, carcass yield on SSC 7, backfat thickness on SSC 7 and SSC X, vertebra number on SSC 1 and SSC 7, loin muscle area on SSC 1 and SSC 7, moisture on SSC 13, intramuscular fat content on SSC 7, and testicular weight on SSC 3 and SSC X. Moreover, 5% genomewise significant QTL were found for birth weight on SSC 7, average daily gain on SSC 4, carcass length on SSC 6, SSC 7, and SSC X and lightness (L value) on SSC 3. We identified 38 QTL for 28 traits at the 5% genomewise level. Of the 38 QTL, 24 QTL for 17 traits were significant at the 1% genomewise level. Analysis of marker genotypes supported the breed of origin results and provided further evidence that a suggestive QTL for circumference of cannon bone also was segregating within the Meishan parent. We identified genomic regions related with growth and meat quality traits. Fine mapping will be required for their application in introgression programs and gene cloning.

Adipose Tissue↗
PubMed2003

Radiation dose-dependent increases in inflammatory response markers in A-bomb survivors.

PURPOSE: The well-documented increases in malignant tumours in the A-bomb survivors have recently been supplemented by reports that non-cancer diseases, including cardiovascular disease, may also have increased in incidence with increasing radiation dose. Given that low-level inflammatory responses are widely accepted as a significant risk factor for such diseases, we undertook a detailed investigation of the long-term effects of ionizing radiation on the levels of the inflammatory markers C-reactive protein (CRP) and interleukin 6 (IL-6) in A-bomb survivors. MATERIALS AND METHODS: Blood samples were taken from 453 participants in a long-term epidemiological cohort of A-bomb survivors. Plasma levels of CRP and IL-6 were measured using standard antibody-mediated procedures. Relationships between CRP or IL-6 levels and radiation dose were then investigated by multivariate regression analysis. Blood lymphocytes from each individual were used for immunophenotyping by flow cytometry with murine monoclonal antibodies to CD3, CD4 and CD8. RESULTS: CRP levels were significantly increased by about 31% Gy(-1) of estimated A-bomb radiation (p=0.0001). Higher CRP levels also correlated with age, male gender, body mass index and a history of myocardial infarction. After adjustments for these factors, CRP levels still appeared to have increased significantly with increasing radiation dose (about 28% increase at 1Gy, p=0.0002). IL-6 levels also appeared to have increased with radiation dose by 9.3% at 1Gy (p=0.0003) and after multiple adjustments by 9.8% at 1Gy (p=0.0007). The elevated CRP and IL-6 levels were associated with decreases in the percentages of CD4(+) helper T-cells in peripheral blood lymphocyte populations. CONCLUSIONS: Our results appear to indicate that exposure to A-bomb radiation has caused significant increases in inflammatory activity that are still demonstrable in the blood of A-bomb survivors and which may lead to increased risks of cardiovascular disease and other non-cancer diseases.

Aged↗
PubMed2002

Genetic linkage maps constructed by using an interspecific cross between Japanese and European pears.

Genetic linkage maps of the European pear ( Pyrus communis L.) cultivar 'Bartlett' and the Japanese pear ( Pyrus pyrifolia Nakai) cultivar 'Housui' were constructed based on AFLPs, SSRs from pear, apple and Prunus, isozymes and phenotypic traits by using their F(1) progenies. The map of the female parent Bartlett consisted of 226 loci including 175 AFLPs, 49 SSRs, one isozyme and one S locus on 18 linkage groups over a total length of 949 cM, while that for 'Housui' contained 154 loci including 106 AFLPs, 42 SSRs, two phenotypic traits and the other four markers on 17 linkage groups encompassing a genetic distance of 926 cM. These maps were partially aligned using 20 codominant markers which showed segregating alleles in both parents. Compared with the reports of apple genetic maps, these pear maps were not saturated but were near saturation. Distorted segregation was observed in two and one regions of the genome of Bartlett and Housui, respectively. The position of 14 SSRs originating from apple could be successfully determined in pear maps, which enabled us to compare the two maps. Some SSRs developed from Prunus (peach, cherry) were also mapped. The relationships between pear and the other species belonging to the Rosaceae were discussed based on the position of SSRs.

Chromosome Mapping↗
PubMed2002

Early decrease of the immunophilin FKBP 52 in the spinal cord of a transgenic model for amyotrophic lateral sclerosis.

Expressions of immunophilin FKBP-12 and FKBP-52 were examined in the spinal cord of transgenic mice with an ALS-linked mutant Cu/Zn superoxide dismutase (SOD1) gene. The immunoreactivity of FKBP-12 was present predominantly in the cytoplasm, but did not show a difference between age-matched wild type and transgenic (Tg) mice at 25 and 35 weeks. In contrast, the immunoreactivity of FKBP-52 was predominantly present in the nucleus, which progressively declined only in the Tg mice as early as an early presymptomatic stage at 25 weeks of age in the anterior horn neurons. The present result suggests that the downregulation of FKBP-52 may be involved in the pathogenesis in the early stages of amyotrophic lateral sclerosis (ALS).

Amyotrophic Lateral Sclerosis↗
PubMed2002

Production of active bovine cathepsin C (dipeptidyl aminopeptidase I) in the methylotrophic yeast Candida boidinii.

The heterologous production of active bovine cathepsin C (CTC; dipeptidyl aminopeptidase I) was investigated. Attempts to express CTC in Escherichia coli were hampered by formation of inclusion bodies that were partially degraded. To overcome this impediment, secretion of recombinant CTC was attempted in the methylotrophic yeast Candida boidinii. A DNA fragment encoding bovine procathepsin C was synthesized based on preferred codon usage in C. boidinii and placed downstream of the C. boidinii proteinase A signal sequence resulting in secretion of active CTC into the culture medium. The gene was expressed under the control of the methanol-inducible formate dehydrogenase gene promoter. Production levels were significantly improved by using a protease-deficient strain, changing medium composition, and by lowering the temperature of induction. When the recombinant C. boidinii was grown for 90 h in a jar-fermenter, active CTC was secreted with a yield of up to approximately 12 mg/l.

Amino Acid Sequence↗
PubMed2002

Quantitative analysis of NF-kappaB-expression in cartilage and synovium of rat knee induced by intra-articular injection of synthetic lipid A.

OBJECTIVE: NF-kappaB expression in cartilage and synovium of rat knee after intra-articular injection of lipid A was investigated. METHODS: Inflammation was evaluated in histological sections stained with hematoxylin and eosin, toluidine blue and immunostained with monoclonal anti-NF-kappaB antibody or monoclonal anti-TNF-alpha antibody. RESULTS: Inflammatory cell infiltration into the synovium, hyperplasia of synovial lining layers, loss of metachromasia of cartilage, TNF-alpha-positive cells and NF-kappaB-positive cells in the synovium and cartilage were observed in all 26 rat knees intra-articularly injected with lipid A. The numbers of TNF-alpha-positive and NF-kappaB-positive synovial cells and chondrocytes after the injection were significantly greater than those in knees injected with triethylamine (p < 0.05). The amount of inflammatory cell infiltration into the synovium, synovial lining layers, TNF-alpha-positive synovial cells and NF-kappaB-positive synovial cells 12 h after the injection was significantly smaller than those after 1 day (p < 0.05). CONCLUSION: Intra-articular injection of lipid A induced NF-kappaB expression in cartilage and synovium. Cartilage degeneration started earlier than synovitis in this model. Quantitative analysis of NF-kappaB in cartilage might be useful to evaluate the extreme acute phase of cartilage degeneration.

Animals↗
PubMed2002

Hemorrhagic infarction of fibroma. MR imaging appearance.

We experienced a case of hemorrhagic infarction of the ovarian fibroma and that indicated the characteristic following appearance: exhibiting a high signal intensity area observed at the periphery of mass on T1-weighted MRI (magnetic resonance imaging). It was thought that this appearance developed because hemorrhagic infarction was caused by subacute ovarian torsion. This is a useful finding for suspecting hemorrhagic infarction preoperatively.

Abdominal Pain↗
PubMed2002

LET distributions from CR-39 plates on Space Shuttle missions STS-84 and STS-91 and a comparison of the results of the CR-39 plates with those of RRMD-II and RRMD-III telescopes.

The LET distributions during the Space Shuttle missions STS-84 (altitude 270-412 km, average 375 km; inclination angle, 51.6 degrees) and STS-91 (altitude 328-397 km, average 373 km; inclination angle, 51.6 degrees) were measured using CR-39 plastic nuclear track detectors. A correction for the dip-angle dependence of the track-formation sensitivity of the CR-39 plates was applied to the data analysis. The absorbed doses and the dose equivalents around RRMD Detector Units, estimated from the LET distributions in the LET region of 4-200 keV/micrometers, fluctuated with standard deviations of +/- 21% to +/- 35% in both flight experiments. The LET distributions obtained from the CR-39 plates agreed well with that obtained from RRMD-II in STS-91. However, the particle fluxes obtained from RRMD-III in STS-84 and STS-91 were two or three times higher than those obtained from RRMD-II and the CR-39 plates. It was concluded that the LET distributions obtained from RRMD-II and the CR-39 plates in the present flight experiments did not include the contribution of target-fragmented secondary heavy particles produced by low-LET particles, such as relativistic or semi-relativistic protons and helium ions, whereas RRMD-III was able to detect these secondary particles because of its low triggering level.

Cosmic Radiation↗
PubMed2002

Malignant melanoma of mandibular gingiva; the usefulness of fat-saturated MRI.

Case report of a histologically validated malignant melanoma affecting the mandibular molar gingiva in a 31-year-old woman. Tumour was evaluated by magnetic resonance (MR) imaging at 1.5-T, spin-echo 3 mm slice thickness with T1-weighted and fat-saturated T1-weighted images. The fat-saturated T1-weighted images demonstrated the lesion more clearly than conventional T1-weighted images.

Adult↗
PubMed2002

Clinical implications of leptin and its potential humoral regulators in long-term low-calorie diet therapy for obese humans.

OBJECTIVE: To address the clinical implications of leptin and to re-examine the relationship between leptin and its potential humoral regulators such as insulin, nonesterified fatty acids (NEFA) and triiodothyronine (T3) in low-calorie diet (LCD) for obese humans. DESIGN: Longitudinal study. SETTING: University and foundation hospitals. SUBJECTS: Ten obese men and 10 premenopausal obese women. INTERVENTIONS: Five men and five women took 800 kcal/day LCD and another five men and five women took 1400 kcal/day balanced deficit diet (BDD) during 4 weeks. RESULTS: Plasma leptin levels in the LCD group decreased more markedly (46.2+/-14.6 to 13.2+/-3.6 ng/ml) than that expected for the decrement in percentage fat (39.0+/-1.7 to 35.9+/-1.7%) and body mass index (BMI; 35.4+/-2.4 to 33.1+/-2.2 kg/m(2)), while that in the BDD group did not decrease significantly (14.9+/-3.5 to 13.4+/-2.8 ng/ml). The ratio of the decrease in leptin levels to that of BMI during the first week was significantly greater than that during the following 3 weeks (39.5+/-2.7 vs 29.3+/-2.1%, P=0.017). The plasma insulin and T3 levels also fell substantially in the first week and continued to decrease during the entire course. Plasma leptin levels measured weekly in each subject were correlated well with insulin (r=0.586, P=0.0003) and T3 (r=0.785, P=0.0004). Multiple regression analyses after adjustment for the time course and BMI revealed that serum levels of T3 were independently correlated with plasma leptin levels (r=0.928, P<0.0001). The plasma NEFA level was markedly elevated during the first 2 weeks and decreased thereafter. CONCLUSIONS: A rapid fall in leptin during the first week of LCD, coordinated by insulin, T3 and NEFA, should be beneficial for responding to decreased energy intake. Inversely, in view of the powerful effect of leptin on energy dissipation, the present findings suggest the potential usefulness of leptin in combination with caloric restriction for the treatment of obesity. SPONSORSHIP: The Ministry of Education, Culture, Sports, Science and Technology of Japan and the Ministry of Health, Labour and Welfare of Japan.

Adolescent↗
PubMed2002

Exercise prescription based upon cardiac vagal activity for middle-aged obese women.

OBJECTIVE: The purposes of this study were to examine a new method to determine exercise intensity for obese people based on the cardiac vagal activity and to determine the effect of this approach on myocardial stress. SUBJECTS: Forty-three middle aged obese female volunteers (age 43.7+/-6.5 y; height 1.56+/-0.05 m; body mass 66.5+/-9.3 kg; body mass index 27.3+/-2.8 kg m(2); percentage body fat 40.7+/-5.9%). MEASUREMENT: In the first experiment, 43 subjects performed a ramp exercise test on a bicycle ergometer with measurement of ECG and gas exchange parameters. In the second experiment, 11 subjects performed 45 min of constant walking exercise on a treadmill at a level corresponding to exercise intensity determined by vagal activity obtained from a ramp bicycle test. Blood pressure, endothelin 1 (ET-1), catecholamine, atrial natriuretic peptide (ANP), and brain natriuretic peptide (BNP) were measured before and after exercise. RESULTS: The heart rate variability power decreased with increasing work rate, and changed little after reaching individual-specific work rate. We presumed that vagal activity disappeared at this point and that the heart rate at this exercise intensity was determined as the vagal activity threshold (T(VA)). The results showed a significant positive correlation (r=0.742, P<0.0001) between T(VA) and ventilatory threshold (VT) heart rates, although the mean heart rate of T(VA) (114.3+/-8.5 beats/min) was significantly lower (P<0.001) than that at VT (119.0+/-11.7), suggesting the cardiac vagal withdrawal occurred prior to the onset of lactate acidosis (lactic acid accumulation). Furthermore, exercise intervention experiment at T(VA) indicated that ET-1, catecholamine and BNP levels were not significantly different before and after exercise. However, ANP levels increased significantly after exercise (pre-exercise 18.6+/-5.38 vs post-exercise 44.0+/-24.87 pg/ml, P<0.001), which in turn brought about a significant post-exercise reduction in the blood pressure (SBP 117.6+/-13.7 vs 110.5+/-7.4 mmHg, P<0.05; DBP 78.6+/-6.7 vs 73.5+/-6.6 mmHg, P<0.01). CONCLUSION: Our data suggest that it is possible to determine the exercise intensity (T(VA)) on the basis of cardiac vagal response. These results also suggest that exercise at T(VA) level is a safe exercise intensity in the light of cardiac stress, and that T(VA) may be recommended for obese people who might possess lower cardiac sympatho-vagal activity.

Adult↗
PubMed2002

Ascending fractional pulse pressure closely relating to large artery function.

It is not known whether ascending fractional pulse pressure (PPf) is related to large artery function. This study was to evaluate whether PPf is associated with large artery function by augmentation index. A total of 190 subjects were enrolled (age range: 50 to 78 years) who had normal contractions, no local asynergy, and no history of myocardial infarction. The ascending aortic pressure was measured using a fluid-filled system. To quantify the relative magnitude of the pulsatile to mean artery pressure, we normalised the pulse pressure to the mean pressure and referred to this value as PPf and the association between the PPf and the augmentation index was investigated. Augmentation index showed significant associations with PPf by univariate analysis (R = 0.690, P < 0.001). The associations between PPf and the factors influencing large artery function were examined by multivariate analysis, and PPf revealed significant associations with age, mean aortic pressure, heart rate and type 2 diabetes (R(2) = 0.477, P < 0.001). The results were that ascending aortic PPf is closely associated with large artery function detected by augmentation index.

Age Factors↗
PubMed2002

Low fractional diastolic pressure in the ascending aorta increased the risk of coronary heart disease.

Although the fractional pulse pressure in the ascending aorta is related to the occurrence of coronary heart disease (CHD) and restenosis after percutaneous transluminal coronary angioplasty, the relative values of diastolic pressure in the ascending aorta at the onset of CHD have not been reported. The purpose of this study was to evaluate whether the relative values of diastolic pressure are associated with the risk of CHD. For this study, we enrolled 406 patients with chest pain, normal contractions, no local asynergy, and no history of myocardial infarction. We measured the ascending aortic pressure using a fluid-filled system. To quantify the relative diastolic pressure, we normalised the diastolic pressures to the mean pressure and referred to this value as the fractional diastolic pressure (FDP). We investigated the association between the FDP and the risk of CHD. Low FDP in the ascending aorta was associated with an increased risk of CHD. The multiple-adjusted odds ratio of CHD was 1.68 (95% CI, 0.67-4.22) in FDP for the middle tertile of the level. The multiple-adjusted odds ratio of CHD was 2.20 (1.16-4.75) in FDP for the lowest tertile compared with the highest tertile. FDP was associated with the risk of CHD.

Adult↗
PubMed2002

Periosteal osteosarcoma of the mandible.

We report a rare case of periosteal osteosarcoma of the mandible in a 15-year-old girl. Extension of the tumour into the bone marrow by way of the periodontal ligament is demonstrated.

Adolescent↗
PubMed2002

The effects of rifampicin on the pharmacokinetics and pharmacodynamics of orally administered nilvadipine to healthy subjects.

AIMS: To study the effects of rifampicin on the pharmacokinetics and pharmacodynamics of nilvadipine. METHODS: Five healthy adult volunteers received nilvadipine (4 mg) orally before and after a 6 day treatment with rifampicin. Blood and urine were collected and assayed for plasma nilvadipine and urinary 6beta-hydroxycortisol and cortisol. RESULTS: The treatment with rifampicin reduced the mean (+/- s.d.) AUC of nilvadipine from 17.4 +/- 8.4 to 0.6 +/- 0.4 microg l-1 h (mean difference -16.8 microg l-1 h, 95% CI -9.4, 24.2 microg l-1 h). While the administration of nilvadipine alone elicited a significant (P < 0.05) hypotensive (mean difference for diastolic blood pressure -8 mmHg, 95% CI -4, -12 mmHg) and reflex tachycardia (mean difference 5 beats min-1, 95% CI 1, 9 beats min-1), the treatment with rifampicin abolished these responses. The urinary 6beta-hydroxycortisol/cortisol ratio showed a significant (P < 0.05) increase from 10.3 +/- 4.0 to 50.3 +/- 24.6 by rifampicin: mean difference 40.1, 95% CI 20.4, 59.8. CONCLUSIONS: Because rifampicin may greatly decrease the oral bioavailability of nilvadipine, caution is needed when these two drugs are to be coadministered.

Administration, Oral↗
PubMed2002

Molecular cloning and characterization of a new Japanese cedar pollen allergen homologous to plant isoflavone reductase family.

BACKGROUND: Japanese cedar (Cryptomeria japonica) pollen is a major cause of seasonal pollinosis, and more than 10% of Japanese people suffer from this allergic disorder. However, only two major pollen allergens, Cry j 1 and Cry j 2, have been identified and exclusively characterized. OBJECTIVE: The aim of this study was to explore and identify important Japanese cedar pollen allergens other than Cry j 1 or Cry j 2. METHODS: C. japonica cDNA library was immunoscreened by rabbit antiserum raised against a partially purified cedar pollen allergen fraction. An isolated cDNA clone was inserted into a glutathione S-transferase (GST)-tagged Escherichia coli expression vector to obtain recombinant GST fusion protein. Non-fusion recombinant protein was purified by glutathione Sepharose affinity chromatography in conjunction with factor Xa cleavage of the GST moiety. IgE-binding ability of the recombinant protein was then evaluated by western blot analysis and enzyme-linked immunosorbent assay (ELISA). RESULTS: The cDNA encodes 306 amino acids with significant sequence similarity to those of plant isoflavone reductase-like proteins, which include a recently identified birch pollen allergen Bet v 5. Western blot analysis demonstrated that recombinant protein was recognized by cedar pollinosis patient IgE. In contrast to Bet v 5 being reported as a minor allergen, the recombinant protein exhibited 76% IgE binding frequency (19/25) against pollinosis patients. CONCLUSION: Here we identified the third member of Japanese cedar pollen allergen homologous to isoflavone reductase. Its high IgE-binding frequency implicates that the isoflavone reductase homologue might be an additional major pollen allergen in C. japonica.

Allergens↗
PubMed2002

Systemic administration of interferon-gamma-expressing plasmid reduces late allergic bronchitis in a mouse model of asthma.

Asthma might be caused by a helper T(Th)2 immune response. We hypothesized that the systemic administration of the Th1 cytokines may reduce the Th2 type late asthmatic response (LAR). We examined the effect of the intraperitoneal injection of interferon(IFN)-gamma-expressing plasmid, a Th1 cytokine, or interleukin(IL)-4-expressing plasmid, a Th2 cytokine, at the time of sensitization on a mouse model of asthma induced by ovalbumin in BALB/c mice. We demonstrated that the IFN-gamma-expressing plasmid reduced the LAR, whereas the IL-4-expressing plasmid enhanced the LAR as compared with the saline or plasmid-only treated group. The present study suggests that the systemic administration of IFN-gamma-expressing plasmid may have a modulating ability of Th1/Th2 balance to down-regulate Th2 response by a mutual inhibitory mechanism between Th1 and Th2 cells, leading to the reduction of the LAR.

Animals↗