Search PubMed⌕ Search

Biomedical subjects

Y Takemura

Publications and source records attributed to Y Takemura.

At least 19 recordsLinked to original sources
PubMed2000

Inhibitory effect of flavonoids from citrus plants on Epstein-Barr virus activation and two-stage carcinogenesis of skin tumors.

To search for possible anti-tumor promoters, thirteen flavones (1-13) obtained from the peel of Citrus plants were examined for their inhibitory effects on the Epstein-Barr virus early antigen (EBV-EA) activation by a short-term in vitro assay. Of these flavones, 3,5,6,7,8,3',4'-heptamethoxyflavone (HPT) (13) exhibited significant inhibitory effects on the EBV-EA activation induced by the tumor promoter, 12-O-tetradecanoylphorbol 13-acetate (TPA). Further, compound 13 exhibited remarkable inhibitory effects on mouse skin tumor promotion in an in vivo two-stage carcinogenesis test.

Animals↗
PubMed2000

Relationship between soluble thrombomodulin in plasma and coagulation or fibrinolysis in type 2 diabetes.

Serum concentration of soluble thrombomodulin (TM) is thought to be a marker for endothelial damage. Although several studies have reported that serum TM concentrations are increased in patients with diabetes mellitus, there is little information on the physiological function of soluble TM in human plasma. To evaluate the relationship of soluble TM in plasma between coagulation and/or fibrinolysis system in patients with diabetes, we measured plasma soluble TM, protein C activity (a natural anticoagulant induced by thrombin-TM complex), prothrombin F1+2 (a direct marker of thrombin generation), and plasmin-alpha 2-antiplasmin complex (PAP) and D dimer (measures of fibrinolytic activity) in 55 patients with type 2 diabetes mellitus. The plasma concentrations of soluble TM (P<0.01), protein C activity (P<0.01), prothrombin F1+2 (P<0.05), PAP (P<0.001) and D dimer (P<0.001) were significantly higher in the diabetic patients than the 48 age-matched control subjects. The plasma concentrations of TM and PAP were obviously increased in patients with diabetic nephropathy. In the diabetic patients, the plasma concentrations of soluble TM were inversely correlated with the protein C activity (r=-0.43, P<0.005), and were positively correlated with the plasma concentrations of prothrombin F1+2 (r=0.63, P<0.0001) and the plasma PAP concentrations (r=0.30, P<0.05). The present study demonstrated that both coagulation and fibrinolysis are enhanced concomitantly in patients with type 2 diabetes mellitus, and that an increase in plasma concentration of soluble TM is associated not only with hypercoagulability but also with enhanced fibrinolysis in diabetic patients.

Adult↗
PubMed2000

Serum levels of carboxy-terminal propeptide of human type I procollagen are an indicator for the progression of diabetic nephropathy in patients with type 2 diabetes mellitus.

The finding that glomerular mesangial cells produce human type I collagen suggests that the serum levels of carboxy-terminal propeptide of human type I procollagen (P1CP) may reflect the severity of diabetic nephropathy. We therefore investigated the relationship between serum P1CP levels and the extent of diabetic complications in 100 patients (46 males and 54 females) with Type 2 diabetes and in 64 healthy subjects. Serum P1CP was determined by radioimmunoassay. In diabetes, we defined P1CP levels less than 142 ng/ml as a normal P1CP group (group A), whereas we defined them as equal to or greater than 142 ng/ml as a high P1CP group (group B). The diabetic patients had significantly elevated serum P1CP levels compared with the controls. The prevalence of hypertension, proliferative diabetic retinopathy or macroalbuminuria was significantly higher in group B than in group A. Serum P1CP levels showed a significant positive correlation with urinary albumin excretion, but not with fasting blood glucose, glycosylated hemoglobin A(1c) or serum osteocalcin. Macroalbuminuric patients showed significantly higher P1CP levels than the normoalbuminuric patients. In patients in the absence of diabetic nephropathy, no significant differences of P1CP levels were found among the severity of diabetic retinopathy. The present results suggest that serum P1CP levels reflect the progression of diabetic nephropathy in patients with Type 2 diabetes.

Biomarkers↗
PubMed2000

Thermographic measurement of skin temperature recovery time of extremities in patients with type 2 diabetes mellitus.

To elucidate the relationship between the recovery of skin temperature in an extremity after exposure to cold water and various factors associated with diabetes, we measured skin temperature in type2 diabetic patients (N=61) and control subjects (N=16). A thermo-tracer was used in thermographic measurements. The right third toe of each subject was immersed in cold water at 0 degrees C for 10 sec. Rt represents the recovery rate of skin temperature at t min after exposure. Rt was significantly reduced in the diabetic patients every 5 min in the 20 min period following exposure compared with control subjects. The diabetic patients group exhibited a significantly positive correlation between R20 and the ankle-brachial index. R20 in the diabetic patients showed a significantly positive correlation with the reduction in systolic blood pressure at the arm observed in Schellong's test. In addition, R20 showed a significantly negative correlation with plasma levels of fibrinogen and plasminogen activator inhibitor-1. However, the severity of diabetic retinopathy and nephropathy was not significantly related to R20 in the diabetic patients. The present data indicate that the recovery of skin temperature after immersion in cold water was markedly reduced in patients with type 2 diabetes mellitus as compared with healthy control subjects. Peripheral arteriosclerosis, impaired sympathetic nerve function and the activation of the blood coagulation system may all contribute to this reduced recovery of skin temperature.

Analysis of Variance↗
PubMed2000

Competitive reverse transcription-polymerase chain reaction assay for quantification of human multidrug resistance 1 (MDR1) gene expression in fresh leukemic cells.

We have analyzed MDR1 gene expression in 69 clinical samples obtained from 64 patients with leukemic hematologic malignancies by using a competitive reverse transcription-polymerase chain reaction assay with a heterologous competitor RNA. To exclude a false-positive result caused by concomitant normal lymphocytes that physiologically express MDR1, in samples we determined a cut-off value of 8 amol MDR1 transcript per microgram of RNA by simultaneous measurement of rhodamine 123 dye efflux either in lymphocyte or gated leukemic cell populations. Consequently, 23 of 69 samples were concluded to be MDR1-positive in leukemic cells per se. The MDR1 expression rate was significantly correlated with factors such as a history of preceding chemotherapy, elder age of the patient, and certain disease types (eg, leukemia progressed from myelodysplastic syndrome). Moreover, the complete response rate after chemotherapy was significantly higher in MDR1-negative patients than in MDR1-positive patients (52% vs 17%, respectively; P = .01). The assay established will enable the quantification of MDR1 gene expression in blood samples from patients with leukemic hematologic malignancies and will be applicable to clinical laboratories as a routine test.

Adolescent↗
PubMed2000

Four new furanone-coumarins from Clausena excavata.

Four new furanone-coumarins, clauslactones-N (4), -O (5), -P (6) and -Q (7) were isolated from the leaves and twigs of Clausena excavata BURM. f. (Rutaceae) collected in Indonesia and their structures were elucidated by spectroscopic analysis.

4-Butyrolactone↗
PubMed2000

A high level of physical fitness during thirties is a negative risk factor for colonic polyps during fifties.

This case-control study examined the relationship between the occurrence of colonic polyps in men in their fifties and the level of their physical fitness while in their thirties. The subjects consisted of 51 male Japan Self-Defense Forces officials in their fifties who had colonic polyps, as diagnosed by colonoscopic examination, and 46 control individuals. As an indicator of physical fitness between 30 and 39, we selected the best time recorded for each individual during that decade of life for the 1,500 meter Physical Fitness Test run. We calculated the odds ratio for polyps according to selected risk factors (including physical fitness), and a logistic regression analysis was used to adjust for possible confounding variables. Odds ratio (95% confidence interval, p value) for colonic polyps with physical fitness in the thirties was 0.36 (0.16-0.82, p < 0.05). With adjustment for the subjects' maximum Body Mass Index in both their thirties and fifties, and serum total cholesterol, the odds ratio was 0.39 (0.15-0.99, p < 0.05). We suggest that the occurrence of colonic polyps in men in their fifties can be reduced by maintaining a high level of physical fitness while in their thirties.

Adult↗
PubMed2000

[Regional differences of in vivo proton MR spectroscopy in developing human brain].

The purpose of this study was to clarify regional differences in proton MR spectroscopy (1H-MRS) in the developing human brain. Proton MR spectra were obtained from 24 infants aged 0 to 24 months old. Proton MR spectroscopy was performed on a 1.5 Tesla clinical MR unit using a 3D-chemical shift imaging sequence (3D-CSI). MR spectra obtained from voxels in frontal white matter and those in parietal white matter were compared. The NAA/Cho ratios of the frontal region were lower than those of the parietal region at birth but increased rapidly during the first six months of life. The rate of increase was reduced in the second year of life. In contrast, NAA/Cho ratios in paracentral areas were already high at birth but increased slowly through the first two years of life. Cho/Cr ratios of the frontal region were stable during the first year of life and started to decrease in the second year of life. In the parietal region, Cho/Cr ratios were decreased throughout infancy. Regional differences in 1H-MRS spectra were apparent during infancy, and these differences were suggested to reflect regional differences in the maturation of the developing human brain.

Adult↗
PubMed2000

[Revolution of the health care delivery system and its impacts on laboratory testing in the United States].

Failure to slow the exponential growth of total health care expenditures in the United States through the government policies resulted in a rapid and progressive penetration of managed care organizations(MCOs) in the early 1990s. Diagnostic testing is viewed as a "commodity" rather than a medical service under the managed care environment. Traditional hospital-based laboratories are placed in a downward spiral with the advent of managed care era. A massive reduction of in-house testing resulted from shorter lengths of patients' hospital stay and a marked decrease in admission under the dominance of managed care urges them to develop strategies for restoring tests deprived by the managed care-associated new businesses: consolidation and networking, participation in the outreach-testing market, and point-of-care/satellite laboratory testing in non-traditional, ambulatory settings are major strategies for survival of hospital laboratories. A number of physicians' office laboratories(POLs) have been closed owing to regulatory restrictions imposed by the Clinical Laboratory Improvement Amendments of 1988(CLIA '88), and to the expanded penetration of MCOs which limit reimbursement to a very few in-house procedures. It seems likely that POLs and hospital laboratories continue to reduce test volumes, while commercial reference laboratories(CRLs) gain more tests through contracting with MCOs. In the current stream of managed care dominance in the United States, clinical laboratories are changing their basic operation focus and mission in response to the aggressively changing landscape. Traditional laboratories which are unwilling to adapt themselves to the new environment will not survive in this country.

Clinical Laboratory Techniques↗
PubMed2000

[A cost-effectiveness analysis of a pre-visit testing system for new outpatients in primary care medicine].

We evaluated cost-effectiveness parameters of common diagnostic test panels advocated by the Japan Society of Clinical Pathology in order to determine the validity of pre-visit testing of these test panels for new outpatients with some defined symptoms. The "Essential Laboratory Tests(ELT) (2)" panel was universally applied to 540 new outpatients who visited the Comprehensive Medicine Clinics in the National Defense Medical College and its affiliated hospital. A "useful result(UR)", the unit of usefulness of the ELT, was assigned by assessing the impact of its results on physician's diagnosis- or decision-making. Patients were classified into 7 major symptom groups according to their chief complaint, and clinical effectiveness(UR/patient), economic efficiency(cost/UR) and cost-effectiveness(delta cost/delta UR) were analyzed in each patient group. Clinical effectiveness ranged from 1.38(renal/urinary tract symptoms) to 0.27 UR/patient(neurological symptoms) with a cost disparity from yen 1,222 to yen 5,946/UR between these patient groups. Substantial decreases in clinical effectiveness were demonstrated in all patient groups with the ELT(1)-testing alone in a simulation study; however, cost-effectiveness parameters still remain in excellent values in the renal/urinary tract symptom and infection/inflammation-related symptom groups(1.13 and 0.77 UR/patient at a cost of yen 836 and yen 1,181/UR, respectively). The addition of some ELT(2)-specific test items such as AST, ALT to the ELT(1) baseline panel improved clinical effectiveness of the ELT(1) in lassitude/exhaustive symptom group at a minimal cost increment. This study verified the validity of the ELT(1) as a panel for pre-visit testing in patients with renal/urinary tract symptoms and infection/inflammation-related symptoms, but not in those with other symptoms.

Adolescent↗
PubMed2000

Opportunistic discovery of occult disease by use of test panels in new, symptomatic primary care outpatients: yield and cost of case finding.

BACKGROUND: Diagnostic test panels have been advocated by the Japan Society of Clinical Pathology for evaluation of presenting complaints of new outpatients in primary care medicine. The tests have additional potential utility for opportunistic finding of asymptomatic diseases, but data are lacking on the number of new conditions identified by the test panels and on the cost per identified case. METHODS: We studied 540 new, symptomatic patients at the Comprehensive Medicine Clinics of National Defense Medical College during 1991-1997. All underwent testing with the "Essential Laboratory Tests" panel (2) [ELT(2) panel]. This panel includes hematologic tests, urinalysis, total protein, C-reactive protein, albumin, cholesterol, triglycerides, glucose, urea nitrogen, creatinine, uric acid, serum protein fractionation, six enzymes, and optional tests, including x-rays, electrocardiogram, and fecal occult blood. RESULTS: The ELT(2) panel uncovered 276 additional diagnoses of asymptomatic disease or abnormal health status. The most frequent occult condition was hyperlipidemia (100 cases) followed by liver dysfunction (53 cases). Clinical efficiency of the panel (occult diseases/patient) varied depending on the category of tentative initial diagnosis, with the highest efficiency in patients with cardiovascular disease. We created smaller panels by combining 11 basic tests [called the ELT(1) baseline panel] with one or more additional tests from the ELT(2) and analyzed their cost-effectiveness. Addition of four tests (total cholesterol, alanine aminotransferase, glucose, and uric acid) improved both clinical efficiency (0.41 occult disease/patient) and economic efficiency [ 2372 yen (approximately $22.50 US)/occult disease] at a cost-effectiveness of 177 yen per incremental case of occult disease. Addition of further tests decreased cost-effectiveness. CONCLUSIONS: Although the ELT(2) panel has supplemental utility for opportunistic screening of some significant, occult diseases and conditions, universal utilization of the full panel is not supported by the cost-effectiveness found in this study.

Adolescent↗
PubMed1999

Microsatellite instability and clonal heterogeneity of MDR1 messenger RNA expression in trimetrexate-resistant human leukemia MOLT-3 cells developed in thymidine.

Various gene alterations are involved in the drug resistance of leukemia cells. To understand the mechanism that underlies the emergence of cells with such gene alterations in human leukemia, we performed clonal analysis of the gene expression of mutant dihydrofolate reductase (DHFR) and mdr1 in trimetrexate-resistant human leukemia MOLT-3 cells. Trimetrexate-resistant (70- and 60-fold) sublines were developed in the presence or absence of an exogenous supply of thymidine (MOLT-3/TMQ70/Th+, MOLT-3/TMQ60/Th-, respectively). Ten clonal lines were isolated by methyl cellulose cloning from each of the 2 trimetrexate-resistant MOLT-3 sublines. All the clonal lines from the 2 sublines expressed mutated DHFR mRNA, with a base change (T --> C) at the second position of codon 31, as well as the wild-type mRNA, in accordance with cross-resistance to methotrexate. On the other hand, mdr1 mRNA expression was demonstrated by reverse-transcription polymerase chain reaction only in clonal lines from MOLT-3/TMQ70/Th+ cells. mdr1 mRNA expression in clonal lines from MOLT-3/TMQ70/Th+ cells and subclonal lines subsequently obtained from the 3 clonal lines with different mdr1 mRNA expression levels was heterogeneous, and its high expression levels were correlated with acquisition of the multidrug resistance (MDR) phenotype. Polymerase chain reaction-based assay for separate microsatellites, mfd27 and mfd41, demonstrated genomic instability among clonal and subclonal lines of MOLT-3. The clonal analysis of polymorphic microsatellites also suggested that emergence of MDR in trimetrexate-resistant MOLT-3 cells in thymidine was not only heterogeneous but also progressively expanding among clones. Genomic instability may play a role in the establishment and clonal evolution of drug resistance in leukemia cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1999

Retrovirus-mediated transfer of anti-MDR1 hammerhead ribozymes into multidrug-resistant human leukemia cells: screening for effective target sites.

One of the underlying mechanisms of multidrug resistance (MDR) is cellular over-production of P-glycoprotein (P-gp), which acts as a drug efflux pump. P-gp is encoded by a small group of related genes termed MDR; only MDR1 is known to confer drug resistance. To overcome P-gp-mediated drug resistance, we have developed two anti-MDR1 hammerhead ribozymes driven by the beta-actin promoter. Upon transduction of the ribozymes into MDR cells, vincristine resistance was decreased. These two ribozymes were constructed, which showed different cleavage activities. In this study, to determine suitable target sites for the anti-MDR1 ribozyme, the exon 1b-intron 1 boundary, the translation-initiation site, the intron 1-exon 2 boundary and the exon 2-intron 2 boundary, codons 179 and 196 of the MDR1 gene were selected as candidates. To improve the ribozyme activity, a retroviral vector containing RNA polymerase III promoter was used. Stable retrovirus producer cells were generated by transfecting the retroviral vector plasmids carrying the ribozyme into the packaging cell line. Retroviral vector transduction of human leukemia cell lines expressing MDR1 was accomplished by co-culturing these with virus producer cells. Stably transduced cells were selected by G418 and pooled to determine the efficacy of each ribozyme. These ribozyme-transduced cells became vincristine-sensitive concomitant with the decreases in MDR1 expression, P-gp amount and drug efflux pump function. Among the ribozymes tested, the anti-MDR1 ribozyme against the translation-initiation site exhibited the strongest efficacy. This retrovirus-mediated transfer of anti-MDR1 ribozyme may be applicable to the treatment of MDR cells as a specific means to reverse resistance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1999

Inhibitory effect of Epstein-Barr virus activation by Citrus fruits, a cancer chemopreventor.

To search useful compounds in Citrus fruit for cancer chemoprevention, we carried out a primary screening of extracts of fruit peels and seeds from 78 species of the genus Citrus and those from two Fortunella and one Poncirus species, which were closely related to the genus Citrus. These Citrus extracts inhibited the Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol 13-acetate (TPA) as a useful screening method for anti-tumor promoters. Our results indicated that Citrus containing substances may be inhibit susceptibility factors involved in the events leading to the development of cancer.

Animals↗
PubMed1999

The protective effect of good physical fitness when young on the risk of impaired glucose tolerance when old.

BACKGROUND: The role of physical activity or fitness on preventing impaired glucose tolerance (IGT) has not been widely investigated. The present case-control study examined the relationship between the occurrence of IGT in men in their 50s and the level of their physical fitness while in their 30s. METHODS: The subjects consisted of 38 male Japan Self-Defense Forces officials in their 50s who had IGT, as diagnosed by the 75-g oral glucose tolerance test, and 60 control individuals. Nine diabetics were included in the IGT cases. As an indicator of physical fitness between the ages of 30 and 39 years, we selected the best time recorded for each individual during that decade of life for the 1,500-m physical fitness test run. We calculated the odds ratio for IGT in relation to selected risk factors (including physical fitness), and a logistic regression analysis was used to adjust for possible confounding variables. RESULTS: The odds ratio (95% confidence interval, P value) for IGT with physical fitness in their 30s was 0.25 (0.11-0.58, P < 0.05). With adjustment for a parental history of diabetes and body mass index in both their 30s and their 50s, the odds ratio was 0.31 (0.11-0.86, P < 0.05). CONCLUSIONS: We concluded that the occurrence of IGT, including diabetes, in men in their 50s can be reduced by maintaining a high level of physical fitness while in their 30s.

Adult↗
PubMed1999

Cross-sectional study on the relationship between smoking or smoking cessation and trait anxiety.

OBJECTIVE: The relationships between trait anxiety, or anxiety proneness, and smoking and between trait anxiety and smoking cessation, among an adult population were investigated. METHODS: The subjects were 2,669 male Japanese personnel working for a Japanese government agency. Participants completed a self-administered questionnaire on smoking and smoking cessation status and other habits. Trait anxiety was evaluated with the trait anxiety part of the standardized Japanese version of the Spielberger State-Trait Anxiety Inventory. Trait anxiety is regarded as the long-term, more endogenous general type of anxiety. Odds ratios of the single 2 x 2 table were calculated and a logistic regression analysis was used to adjust for age. RESULTS: After adjusting for age, high trait anxiety did not increase the risk of smoking and was not related to success in abstaining from smoking. More subjects with high trait anxiety had planned to stop smoking (adjusted odds ratio: 1.39, P = 0.01) but did not actually succeed in doing so. CONCLUSION: The present study did not support the hypothesis that high trait anxiety increased the risk of having a smoking habit and that high trait anxiety increased the chance of abstaining from smoking. However, the study did show that high trait anxiety was related to the planning of smoking cessation, but not to actually giving up the smoking habit.

Adult↗
PubMed1999

Biomechanical study of the development of scoliosis, using a thoracolumbar spine model.

A thoracolumbar spine model was made using synthetic resin vertebrae and silicon discs. The model was fixed to a metal frame and spinal deformation caused by loading was determined relative to three-dimensional coordinates set in the frame. A three-dimensional evaluation of the development of spinal deformity was performed by applying rotational, lordotic, and lateral flexional forces in various orders to the model. The most severe scoliosis occurred when loading was done in the order of rotational force, lordotic force, and lateral flexional force.

Biomechanical Phenomena↗