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Biomedical subjects

T Ohta

Publications and source records attributed to T Ohta.

At least 55 records · Page 3Linked to original sources
PubMed2003

Relationship of lifestyle factors to bone mass in Japanese women.

BACKGROUND: Japanese women have a lower bone mass and smaller calcium intake than Caucasians. OBJECTIVE: To investigate the differences in the relationship between bone mass and lifestyle among Japanese women of different life stages. DESIGN: Cross-sectional and longitudinal investigations of the relationship between bone mass and lifestyle in Japanese women aged 15-69 years. RESULTS: In both cross-sectional and longitudinal investigations of high school students, exercise was shown to effectively increase bone mass. In the longitudinal investigation, bone mass was generally greater with high or increased milk consumption. In the cross-sectional investigation of nonparous women and women more than 36 months post partum, those who exercised had significantly higher bone mass. Twelve to 35 months post partum, bone mass was greater in women with higher calcium or milk intake. The effects of parity were not investigated longitudinally, but women who continuously exercised or started exercise had greater bone mass. Non-exercising women with a higher or increased frequency of intake of dairy products, small fish, and soy products had increased bone mass. The longitudinal investigations suggest that exercise increases bone mass in pre-menopausal women. In women just after menopause, it was shown cross-sectionally that bone mass was greater with a higher calcium intake, and longitudinally that exercise resulted in a slower decrease in bone mass. Among women more than 6-7 years past menopause, exercise inhibited the decrease in bone mass. CONCLUSION: The relationship between these lifestyle factors and bone mass differs according to pregnancy status and time since menopause.

Adolescent↗
PubMed2002

Indications for and limitations of exercise training in patients with intermittent claudication.

BACKGROUND: The selection of candidates for exercise training among patients with intermittent claudication is still a matter of debate. PATIENTS AND METHODS: Forty-nine patients with intermittent claudication due to arteriosclerosis obliterans were tested. Forty-six patients were men and 3 were women, with an average age of 65 years (range, 46 to 76 years). The patients walked on a treadmill at 2.4 km/h on a 12% upgrade followed by an appropriate period of rest for 30 minutes twice a day during a 3-week hospitalization. Programs were individualized for each patient. Four parameters were assessed after exercise training: (1) Ankle-brachial index (ABI) at rest, (2) Fall in ABI after 40 m of treadmill walking (ABI Fall 40), (3) the recovery time (RT 40) required for the ABI to return to resting levels after 40 m of walking, and (4) the maximal walking distance (MWD) on the treadmill. RESULTS: The average ABI at rest before the 3-week training period was 0.60 +/- 0.02 (mean +/- SE), and after training it was 0.62 +/- 0.02. There was a small although not statistically significant increase in the ABI after training. This increase in the ABI did not exceed 0.21. The average ABI Fall 40 before training was 0.36 +/- 0.01, and after training it was 0.30 +/- 0.02. The average RT 40 before training was 9.9 +/- 0.8 min, and after training it was 6.2 +/- 0.6 min. There were significant decreases in the ABI Fall 40 and RT 40 after training (p < 0.01 and p < 0.001, respectively). The MWD increased after training in 48 of the 49 patients. The average MWD increased from 134 +/- 13 m to 226 +/- 32 m after training (p < 0.001). The occlusion levels did not influence the results as training effects and hemodynamic parameters. Fourteen of 49 patients desired arterial reconstruction after exercise training. CONCLUSIONS: Patients with shorter RT 40's before training achieved greater increases in the MWD after training. In patients with an RT 40 under 12 min, exercise training is indicated. However, there is some discrepancy between the increase in MWD and the degree of satisfaction in individual patients.

Aged↗
PubMed2002

Obesity, weight change and risks for hypertension, diabetes and hypercholesterolemia in Japanese men.

OBJECTIVE: To examine the effects of the degree of body mass index and weight gain as the risks for hypertension, hypercholesterolemia and diabetes in Japanese men, and to compare that to the corresponding effects in a Caucasian population. DESIGN: Prospective cohort study. SETTING: Cohort of all male employees at a company. SUBJECTS: A total of 4737 male employees followed until retirement or for 4 y (longest term 4 y). RESULTS: Increase of body mass index beyond 22 kg/m(2) related to an increased risk for hypertension even after being adjusted for possible confounding factors such as age, smoking status, alcohol intake, family history and baseline value of systolic blood pressure. The risks greatly increased in subjects with a body mass index above 27 kg/m(2) for hypertension, and 29 kg/m(2) for diabetes and hypercholesterolemia. Weight gain (more than 2 kg) was strongly related to an increased risk for hypertension and hypercholesterolemia after being adjusted for possible confounding factors. However, weight gain was not related to diabetes, and weight loss did not decrease the risks for any of the three diseases. CONCLUSIONS: Among Japanese, the degrees of body mass index associated with risks for hypertension, diabetes and hypercholesterolemia were lower than those in Caucasians. The risks for hypertension and hypercholesterolemia were strongly associated with weight gain in a Japanese male population who showed a low prevalence of severe obesity, and the risks were similar to or somewhat higher than those in a Caucasian population with a high prevalence of severe obesity. SPONSORSHIP: Health Science Research Grant by the Ministry of Health and Welfare of Japan.

Adolescent↗
PubMed2002

Inhibitory effects of cortical steroids and adrenocorticotropic hormone on catecholamine secretion in guinea-pig perfused adrenal glands.

1 We investigated the effects of exogenously applied steroids and endogenously released cortisol on catecholamine (CA) secretion induced by cholinergic agonists in perfused guinea-pig adrenal glands. 2 Acetylcholine (ACh) and electrical stimulation induced CA secretion, which was reversibly inhibited by cortisol. Adrenocorticotropic hormone (ACTH) increased the concentration of cortisol in the perfusion effluent and partly inhibited the secretory response to ACh. 3 Cortisol or aldosterone dose-dependently inhibited secretory responses to nicotine and muscarine. These inhibitory effects were not antagonized by mifepristone and spironolactone, respective cortisol and aldosterone receptor blockers. 4 Dexamethasone, cortisone, corticosterone, 11-deoxycortisol, 11-deoxycorticosterone, prednisolone and cholesterol inhibited nicotine-evoked CA secretion. The secretory response to muscarine was inhibited by these compounds except for dexamethasone and prednisolone. 5 Dexamethasone, cortisol and aldosterone had no effect on CA secretion induced by high KCl. 6 These results suggest that steroids affect nicotinic and muscarinic ACh receptor-mediated responses through distinct mechanisms, and that cortisol released from the adrenal cortex inhibits CA secretion from the adrenal medulla.

Adrenal Cortex Hormones↗
PubMed2002

Diagnostic laparoscopy, serum CA125, and peritoneal metastasis in gastric cancer.

BACKGROUND AND STUDY AIMS: Peritoneal metastasis is a crucial factor for the prognosis in gastric cancer, but its diagnosis is difficult before laparotomy. We report on the utility of laparoscopy and its indications in the detection of peritoneal metastasis in gastric cancer. PATIENTS AND METHODS: A total of 39 patients with gastric cancer underwent laparoscopy and peritoneal cytology investigation in our department, between April 1992 and April 2000. Laparoscopic diagnosis for peritoneal metastasis (LP-P) was determined through macroscopic, pathological and cytological diagnoses. All the patients underwent diagnostic imaging with computed tomography (CT) and ultrasound before laparoscopy. Carcinoembryonic antigen, carbohydrate antigen (CA) 19-9, and CA125 levels in serum and peritoneal fluid were measured using enzyme immunoassay. RESULTS: Laparoscopic diagnosis for peritoneal metastasis gave negative results in 21 patients and positive results in 18. All the patients with negative LP-P findings underwent surgery; 18 of the 21 patients showed no peritoneal metastasis, but three were diagnosed as having peritoneal metastasis, one at the pouch of Douglas and two at the mesentery. The diagnosis of all the patients with positive LP-P findings was finally confirmed as correct. The specificity, sensitivity, and accuracy of laparoscopy for peritoneal metastasis were 100 % (18/18, 95 % CI 0.82 - 1), 86 % (18/21, 95 % CI 0.64 - 0.97), and 92 % (36/39, 95 % CI 0.79 - 0.98), respectively. The specificity, sensitivity, and accuracy of diagnostic imaging for peritoneal metastasis were 100 % (18/18, 95 % CI 0.82 - 1), 38 % (8/21, 95 % CI 0.18 - 0.62), and 67 % (26/39, 95 % CI 0.50 - 0.81), respectively. All of the 11 patients showing high levels of serum CA125 (equal to or more than 35 U/ml) had peritoneal metastasis whereas 17 of the 26 patients with low levels of serum CA125 (less than 35 U/ml) did not ( P < 0.001). CONCLUSIONS: The sensitivity of laparoscopy for peritoneal metastasis was much higher than that of diagnostic imaging. Laparoscopy and serum CA125 level both predicted peritoneal metastasis, but the degree, volume, or distribution of peritoneal metastasis was disclosed only by laparoscopy. Laparoscopy is a useful way of detecting peritoneal metastasis in gastric cancer, and patients with an elevated level of serum CA125 are the best candidates for laparoscopy.

Adult↗
PubMed2002

Exercise-induced acute renal failure with renal hypouricemia: a case report and a review of the literature.

A previously healthy 16-year-old boy developed acute renal failure following a track race at a local athletic meeting. Several hours after the run, he expressed pain in the loins with nausea and vomiting. After 3 sessions of hemodialysis, he was referred to our hospital. On admission, serum creatinine was elevated to 2.3 mg/dl without an increase in serum uric acid level. After recovery from acute renal failure (ARF), hypouricemia (0.7 mg/dl) became evident in the patient. One year later, he suffered from ARF after a track race with the highest creatinine levels of 1.1 mg/dl. In order to clarify the cause and prognosis of ARF with renal hypouricemia, we summarized the clinical features in 18 patients previously described and our patient. Serum uric acid levels after recovery from ARF were below 1.0 mg/dl in all patients. Renal biopsy in 9 patients showed acute tubular necrosis in 8 patients and uric acid nephropathy in 1. The short-term prognosis of these patients seemed good, although 5 patients needed to undergo hemodialysis in their ARF courses. However, the recurrence of ARF episodes occurred in 6 patients (31.6%) including our patient, indicating that prevention of ARF might be necessary in these patients. More information is required to establish guidance for prevention of ARF.

Acute Kidney Injury↗
PubMed2001

Enhanced invasiveness of pancreatic adenocarcinoma cells stably transfected with cationic trypsinogen cDNA.

Various studies have described increased expression of cationic trypsinogen in malignant tumor cells. To explore the role of secreted cationic trypsinogen in invasion by cancer cells, we introduced cationic trypsinogen cDNA into Panc-1, a pancreatic adenocarcinoma-derived cell line that lacks expression of endogeneous trypsinogen. Four independent clones (designated Panc-1-Try-7, -9, -11 and -24) stably expressing cationic trypsinogen mRNA were isolated and processed for further study. In a zymographic analysis, gelatinolytic activity for cationic trypsinogen was detectable in serum-free conditioned media obtained from all 4 transfectants but not in media from mock-transfected or parental Panc-1 cells. A Matrigel invasion assay revealed that all trypsinogen-expressing transfectants acquired significantly greater invasive ability than that shown by mock-transfected and parental Panc-1 cells. In addition, enhanced invasiveness of the transfectants was suppressed by FUT-175, a serine protease inhibitor, to the level seen in parental cells. These results provide direct evidence that cationic trypsinogen can increase the invasive ability of carcinoma cells.

Adenocarcinoma↗
PubMed2001

[A case of autoimmune progesterone dermatitis].

A 41-year-old Japanese woman came to our clinic complaining of multiple edematous erythemas on the trunk and legs. The eruptions recurred periodically in association with the menstrual cycle. She had received oral progesterone therapy between 24 and 34 years of age. There were no abnormal values found in the routine and hormonal examinations, including progesterone and estrogen levels in serum and urine. After an intradermal skin test with progesterone, she had no reaction after 20 minutes but a positive reaction after 48 hours.

Adult↗
PubMed2001

Novel peptidomimetics of the antifungal cyclic peptide Rhodopeptin: design of mimetics utilizing scaffolding methodology.

[reaction: see text]. Novel nonpeptide peptidomimetics of the antifungal cyclic peptide Rhodopeptin were designed utilizing hydantoin, benzimidazole, D-glucosamine, quinolone, and benzodiazepine units as scaffolds. The scaffolds were chosen on the basis of their potential to improve the physiochemical properties of the peptidomimetics as well as their ability to bear the requisite Rhodopeptin side-chain moieties with the proper three-dimensional orientation.

Antifungal Agents↗
PubMed2001

Novel peptidomimetics of the antifungal cyclic peptide Rhodopeptin: synthesis of mimetics and their antifungal activity.

[reaction: see text]. Novel peptidomimetics of the antifungal cyclic peptide Rhodopeptin were synthesized. As with the cyclic peptides, the presence of all three Rhodopeptin side chains was found to be indispensable for peptidomimetic activity. We discovered new compounds exhibiting greater antifungal activity and improved physiochemical properties in comparison to the parent compounds.

Alkanes↗
PubMed2001

Overexpression of sigma factor, sigma(B), urges Staphylococcus aureus to thicken the cell wall and to resist beta-lactams.

Whole genome sequence analysis revealed that Staphylococcus aureus is provided with only a few sigma factors, including the alternative sigma factor, sigma(B), which is thought to regulate some stress responses. Since the sigB knock-out mutant did not show remarkable phenotypic difference, we constructed the over expressed mutant to examine the role of the sigB. Electron microscopic observation revealed that the mutant showed a variety of cell sizes compared with the parent strain which showed almost homogeneous cell sizes. The mutant delivered a thicker cell wall, about 20% thicker than the parent strain. It became resistant to the lytic activity of lysostaphin and also raised MICs to the cell-wall-affecting antibiotics. The yield of carotenoids and transcripts of pbps were also increased in the mutant. The result suggests that sigB plays some important roles in cell wall synthesis and in resistance to antibiotics that perturb the cell wall synthesis.

Bacterial Proteins↗
PubMed2001

Resveratrol and quercetin inhibit angiogenesis in vitro.

Resveratrol and quercetin are polyphenolic compounds found in grapes, red wine and other food products. In this study, we examined the effect of resveratrol and quercetin on the inhibition of angiogenesis in vitro. Resveratrol and quercetin inhibited the growth of bovine aorta endothelial (BAE) cells in a concentration-dependent manner (6-100 microM).The migration of BAE was obviously inhibited by resveratrol and weakly inhibited by quercetin. When the lengths of all tubes constructed in the 3-D culture system with or without resveratrol or quercetin were measured, resveratrol was found to inhibit the tube formation of BAE cells in a concentration-dependent manner (6-100 microM). On the other hand, quercetin at concentrations above 100 microM significantly inhibited the tube formation of vascular endothelial cells. From these results, we suggest that resveratrol and quercetin may prove useful in the development of useful therapeutic agents or preventive food factors for tumor angiogenesis.

Angiogenesis Inhibitors↗
PubMed2001

Self-propulsion of cellular structures in chemically reacting mixtures.

An alternative model of phase-separating reactive mixtures is proposed. In this model both phase separation and chemical reactions simultaneously take place and a traveling coherent structure can be formed through a Hopf bifurcation at a finite wave number. Numerical simulations show that, depending on the parameters, either lamellar or hexagonal structures travel at constant speeds in two-dimensional systems.

Journal Article↗
PubMed2001

Oxidative DNA damage induced by high glucose and its suppression in human umbilical vein endothelial cells.

In order to investigate the mechanism of the production of oxidative DNA damage by hyperglycemia, we measured formamidopyrimidine N-glycosylase (FPG)-sensitive sites by the comet assay in human umbilical vein endothelial cells (HUVECs) cultured under various conditions including high glucose. Mean values of FPG-sensitive sites were higher in HUVECs cultured for 5 days in high glucose (45 mM) compared with normal glucose (5mM) medium (P<0.001). FPG-sensitive sites increased in a time-dependent manner under high glucose treatment (3 days: P<0.05, 5 days: P<0.001), whereas L-glucose, which is taken up poorly into the cells, gave a slight increase in FPG-sensitive sites (P<0.05). Flow cytometric analysis using 6-carboxy-2',7'-dichlorodihydrofluorescein diacetate, di(acetoxymethyl ester) showed that incubation with L-glucose produced more reactive oxygen species than incubation with D-glucose. However, these increases were slight (1.22- and 1.12-folds, respectively). Incubation of HUVECs with aminoguanidine (100 microM) or pyridoxamine (1mM), which are inhibitors of glycation, decreased the levels of FPG-sensitive sites (P<0.001). However, these inhibitors did not suppress the intracellular generation of reactive oxygen species induced by high glucose. These results indicate that FPG-sensitive sites induced by high glucose are not due to intracellular reactive oxygen species. In order to clarify what caused the induction of FPG-sensitive sites, we investigated the effect of glyoxal and 3-deoxyglucosone (3-DG) on the induction of FPG-sensitive sites and the intracellular production of reactive oxygen species in HUVECs. Glyoxal and 3-DG at a concentration of 100 microg/ml induced FPG-sensitive sites (P<0.001, P<0.01, respectively). In contrast, glyoxal did not generate reactive oxygen species inside HUVECs. The results shown in this study suggest that glyoxal formed intracellularly or extracellularly during high glucose treatment might induce FPG-sensitive sites by a mechanism not involving reactive oxygen species.

Binding Sites↗
PubMed2001

Apoptosis induction by epigallocatechin gallate involves its binding to Fas.

Epigallocatechin gallate (EGCG) is known to induce apoptosis in various types of tumor cells, but the precise mechanism by which EGCG induces apoptosis remains to be elucidated. The Fas-Fas ligand system is one of the major pathways operating in the apoptotic cascade. The aim of this study was to examine the possibility that EGCG-binding to Fas triggers the Fas-mediated apoptosis. The EGCG treatment of human monocytic leukemia U937 cells resulted in elevation of caspase 8 activity and fragmentation of caspase 8. The DNA ladder formation caused by the EGCG treatment was inhibited by the caspase 8 inhibitor. These findings suggested the involvement of the Fas-mediated cascade in the EGCG-induced apoptosis in U937 cells. Affinity chromatography revealed the binding between EGCG and Fas. Thus, the results suggest that EGCG-binding to Fas, presumably on the cell surface, triggers the Fas-mediated apoptosis in U937 cells.

Apoptosis↗