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Biomedical subjects

K Tsutsumi

Publications and source records attributed to K Tsutsumi.

At least 37 records · Page 2Linked to original sources
PubMed2001

The effect of pregnancy on cytochrome P4501A2, xanthine oxidase, and N-acetyltransferase activities in humans.

OBJECTIVE: Our objective was to evaluate the activity of cytochrome P4501A2 (CYP1A2), xanthine oxidase (XO), and N-acetyltransferase 2 (NAT2) from early to late pregnancy and after delivery. METHODS: Twelve women were studied on three occasions during pregnancy (early, 8-16 weeks' gestation; middle, 20-28 weeks' gestation; and late, 32-39 weeks' gestation) and about 1 month after delivery. Caffeine was used as a metabolic probe. After the women ingested a can or a bottle of caffeine-containing soft drink, urine samples were collected for 12 hours. The caffeine metabolites measured were 5-acetylamino-6-amino-3-methyluracil (AAMU), 1-methylxanthine (1X), 1-methyl-uric acid (1U), 1,7-dimethyl-uric acid (17U), and 1,7-dimethylxanthine (17X). The hepatic enzyme activities were estimated by the urinary caffeine metabolic ratios as follows: CYP1A2 = (AAMU + 1X + 1U)/17U; XO = 1U/(1X + 1U); NAT2 = AAMU/(AAMU + 1X + 1U). RESULTS: Statistically significant differences were found in CYP1A2 (P < .0001) and NAT2 (P < .01). The mean metabolic ratios for CYP1A2 during pregnancy (6.80, 5.18, and 4.97 for the early phase, middle phase, and late phase, respectively) were significantly lower than the ratio after delivery (10.39). The mean metabolic ratio for NAT2 in the early phase (0.57) was significantly lower than after delivery (0.66). There was no significant difference in metabolic ratios for XO during pregnancy and after delivery. CONCLUSION: The data demonstrate that pregnancy influences CYP1A2 and NAT2 activity. CYP1A2 activity decreases not only in late pregnancy but also in early and middle pregnancy.

Adult↗
PubMed2001

Association between job strain and prevalence of hypertension: a cross sectional analysis in a Japanese working population with a wide range of occupations: the Jichi Medical School cohort study.

OBJECTIVES: To explore the association between the prevalence of hypertension in a Japanese working population and job strain (a combination of low control over work and high psychological demands), and to estimate this association in different sociodemographic strata. METHODS: From a multicentre community based cohort study of Japanese people, sex specific cross sectional analyses were performed on 3187 men and 3400 women under 65 years of age, all of whom were actively engaged in various occupations throughout Japan. The baseline period was 1992-95 [corrected]. The association between job characteristics--measured with a Japanese version of the Karasek demand-control questionnaire--and the prevalence of hypertension defined by blood pressure and from clinical diagnoses were examined. Adjustments were made for possible confounders. The analyses were repeated for stratified categories of occupational class, educational attainment, and age group. RESULTS: In men, the level of job strain (the ratio of psychological job demands to job control) correlated with the prevalence of hypertension. In a multiple logistic regression model, job strain was significantly related to hypertension (odds ratio 1.18; 95% confidence interval 1.05 to 1.32), after adjustment for age, employment (white collar v blue collar), marital status, family history of hypertension, cigarette smoking, alcohol intake, physical activity, and body mass index. The stratified analyses showed significant excess risks in the subordinate groups compared with managers, blue collar workers, less educated workers, and the older age groups. This association was not significant in women. Multiple linear regression analyses, with systolic and diastolic blood pressures as dependent variables, did not show any significant association. CONCLUSIONS: The findings provided limited proof that job strain is related to hypertension in Japanese working men. Older men in a lower social class may be more vulnerable to the hypertensive effects of job strain.

Adult↗
PubMed2001

Risk of aneurysm recurrence in patients with clipped cerebral aneurysms: results of long-term follow-up angiography.

BACKGROUND AND PURPOSE: With many patients living long after microsurgical aneurysm clipping for subarachnoid hemorrhage (SAH) and with the evolution of intravascular procedures as less invasive alternatives, knowledge of the long-term results of clipping is becoming important. METHODS: Of 412 patients who underwent clipping of ruptured or unruptured cerebral aneurysms at our institution between 1976 and 1994 and who survived >3 years after surgery, 225 patients who were in good general condition and younger than 80 years were offered follow-up angiography to detect newly formed aneurysms. Of the 225, 80 patients (35.6%) agreed to undergo angiography. In addition, 32 patients underwent angiography for new medical indications other than SAH. Therefore, 112 patients underwent angiography, representing a total of 140 clipped aneurysms. RESULTS: The mean interval from surgery was 9.3 years for all patients and 9.0 years for the clipped aneurysms (range 3 to 21 years). Four aneurysm regrowths were detected of the 140 (2.9%) clipped aneurysms, representing 3 of 125 completely clipped aneurysms, 1 of 14 incompletely clipped aneurysms, and 0 of 1 aneurysm not studied with postoperative angiography. De novo aneurysms were detected in 9 of 112 (8.0%) patients. The annual rate of de novo aneurysm formation was 0.89%. CONCLUSIONS: This study shows that the annual rate of de novo aneurysm formation is relatively high (0.89%) and that the cumulative risk becomes significant after 9 years. In consideration of the fatality rate of SAH, follow-up angiography may be indicated for patients with clipped aneurysms 9 to 10 years after surgery.

Angiography, Digital Subtraction↗
PubMed2001

Reduction cranioplasty for craniocerebral disproportion due to chronic subdural hematoma in infants. A technical report.

Advanced craniocerebral disproportion due to chronic subdural hematoma in infants which is resistant to conventional treatments requires reduction cranioplasty as the last resort. The present paper deals with our experience with two such cases originated from head injury. Since the volume of the hematoma cavity was calculated based on the pre-operative CT scans, we devised a mathematical formula to design how the cranial vault could be reconstructed for reduction. This enabled us to pre-determine the extent of cranial reduction which was tailored to each patient. Furthermore, the present methodology is characterized by the modification that the midline bone strip overlying the superior sagittal sinus was shortened at its anterior end and bent down using the posterior end as a hinge. Since the follow-up results were favorable, this technique of reduction cranioplasty is reported in detail.

Cerebral Cortex↗
PubMed2001

The relationship between plasma high density lipoprotein cholesterol levels and cholesteryl ester transfer protein activity in six species of healthy experimental animals.

Plasma high-density lipoprotein cholesterol (HDL-C) concentrations are regulated by plasma cholesteryl ester transfer protein (CETP) in humans. The aim of this study was to ascertain the relationship between plasma HDL-C and plasma CETP activities in mouse, rat, dog, hamster, rabbit and monkey. In this study, the plasma HDL-C levels were highest in dogs and lowest in rabbits among the six species. Plasma CETP activities were higher in hamsters, rabbits and monkeys compared to mice, rats and dogs. The present study shows that there are species differences in HDL-C and CETP activity in six species of healthy experimental animals, with the six species being separated into two types. The first type showed a high HDL-C/TC ratio with low or absent CETP activity, and included mouse, rat and dog, whereas the second type showed a low HDL-C/TC ratio and high CETP activity, and included hamster, rabbit and monkey. The present study also shows that there is a strong relationship between plasma HDL-C levels and CETP activity in high CETP activity animals and that the relationship between the HDL-C/TC ratio and CETP activity is an important factor in all animals, regardless of CETP activity level.

Animals↗
PubMed2001

Exercise improved accumulation of visceral fat and simultaneously impaired endothelium-dependent relaxation in old rats.

Exercise decreases plasma total cholesterol and triglycerides, and simultaneously, increases high density lipoprotein (HDL) cholesterol. Furthermore, it has been reported that exercise improves insulin resistance. As a result, exercise is believed to aid in preventing atherosclerosis. However, we do not know whether exercise protects against the development of atherosclerosis in the elderly. The aim of this study was to ascertain whether exercise prevented atherosclerosis in aorta of old rats. Exercise for three months did not affect plasma lipid levels but decreased accumulation of visceral fat and body weight without the reduction of food intake in two year old rats. Exercise also decreased triglycerides in liver and gastrocnemius white muscle. Exercise resulted in an elevation of plasma lipid peroxide (LPO) levels without affecting superoxide dismutase (SOD). Exercise impaired the endothelium-dependent relaxation of the thoracic aorta caused by acetylcholine in old rats. In summary, the results of our study indicate that exercise induces the reduction of visceral fat, body weight and triglyceride contents in tissues in old rats. These results seems to show that exercise improves insulin resistance. However, exercise simultaneously may cause impaired endothelium-dependent relaxation by elevation of LPO in old rats.

Adipose Tissue↗
PubMed2001

Delayed central respiratory dysfunction after Wallenberg's syndrome--case report.

A 68-year-old man presented with Wallenberg's syndrome consisting of ataxia, dysphagia, hypesthesia on the left side of the body, and Horner's syndrome on the right. Magnetic resonance (MR) imaging revealed a right lateral medullary infarction and small multiple lacunae scattered in the upper medulla. Neurological symptoms improved in a week and the patient was discharged with mild residual hypesthesia on the left side. However, 31 days later, he was emergently admitted after suddenly becoming apneic and losing consciousness. MR imaging detected no new lesion. The patient was placed under ventilation support for 48 hours before regaining normal respiratory function. Medullary infarction sometimes causes catastrophic respiratory failure, but Wallenberg's syndrome caused by lateral medullary infarction is rarely associated with central respiratory dysfunction, and delayed onset of central respiratory dysfunction is extremely unusual. Delayed onset of central respiratory failure is a life-threatening complication of the medullary infarction causing Wallenberg's syndrome, which in general is not recognized.

Aged↗
PubMed2001

Infra-posterior inferior cerebellar artery aneurysm arising after occlusion of the ipsilateral vertebral artery--case report.

An 85-year-old woman had subarachnoid hemorrhage due to rupture of a very rare left infra-posterior inferior cerebellar artery (PICA) aneurysm, a saccular aneurysm located proximally at the junction of vertebral artery (VA) and PICA. Right vertebral angiography demonstrated the aneurysm since the left VA was occluded in the extracranial portion. The aneurysm projected in the opposite direction to common VA-PICA aneurysms. The angiographical and intraoperative findings imply this rare aneurysm resulted from the hemodynamic changes caused by the VA occlusion. Detailed exploration of angiography is emphasized to detect such rare aneurysms among the diversity of hemodynamic patterns in elderly patients with subarachnoid hemorrhage.

Aged↗
PubMed2001

[Resistance to Fas-mediated apoptosis in human papillomavirus type 16-immortalized human laryngeal epithelial cells after tumorigenesis].

Apoptosis plays an important role in such biological processes as multistep carcinogenesis. Human papillomavirus type 16(HPV16)-immortalized human epithelial cell lines are, for the most part, nontumorigenic in nude mice and useful for studying mechanisms involved in multistep carcinogenesis. We previously reported that HPV16-immortalized human laryngeal epithelial cell line HLEC16 formed tumors after treatment with 4-(methyl-nitrosamine)-1-(3-pyridyl)-1-butanone, and derived one tumorigenic cell line, HLEC16T. We compared sensitivity to Fas receptor-mediated apoptosis of nontumorigenic HLEC16 and tumorigenic HLEC16T. HLEC16 and HLEC16T expressed Fas protein (Fas) but not Fas-ligand (FasL) mRNA. We applied an anti-Fas monoclonal, antibody, CH11, to HLEC16 and HLEC16T, and monitored cell death. HLEC16T was found to be significantly less sensitive to CH11-mediated cell death that HLEC16. Western blot analysis showed no significant difference in levels of apoptosis-inducing protein, Bax, between HLEC16 and HLEC16T. Levels of apoptosis-inhibiting proteins Bcl-2 and Bcl-XL increased in HLEC16T. These results suggest that the inhibition of Fas-mediated apoptosis through apoptosis-inhibiting protein overexpression may promote tumorigenicity in HLEC16T.

Animals↗
PubMed2001

Mitochondrial DNA polymorphism of a triploid form of Fasciola in Japan.

Mitochondrial DNA polymorphism was characterized in a triploid form of Fasciola found in Japan in comparison with F. hepatica, F. gigantica and Korean Fasciola worm. Seventy worms of Fasciola from Japan, three of F. hepatica from Uruguay and Australia, two of F. gigantica from Thailand and one of Fasciola from Korea were used in the study. Mitochondrial DNA polymorphism was detected by restriction fragment length polymorphism (RFLP) using eight restriction enzymes, BamH I, Bgl II, Dra I, EcoR I, EcoR V, Hind III, Mfl I and Sca I. Three different types (types 1, 2 and 3) were detected from 76 Fasciola worms used in the study. Eight of 70 Japanese worms were categorized in type 2 (F. gigantica type), and the remaining 62 were in type 3 (F. hepatica type).

Animals↗
PubMed2000

An overlapping set of DNA elements in the rat aldolase B gene origin/promoter regulates transcription and autonomous replication.

Promoter of the rat aldolase B (AldB) gene is centered on an origin of chromosomal DNA replication in vivo, and it directs autonomous replication upon transfection into cultured cells. Previous studies showed that the 200 bp promoter fragment is necessarily required for the autonomous replication. Here, we identified three cis-elements required for replication within the 200 bp promoter, using autonomously replicating plasmids carrying various mutations and deletions. One is an element that is previously defined as a regulatory element for liver-specific transcription (site C). Other two, purine-rich (site PPu) and A (T)-rich (site A/T) sequences, were those often found in eukaryotic origin regions. Sites C and PPu were found to bind specific nuclear factors in transfected cells, and the results of competitive binding assay implied direct or indirect interaction between sites C and PPu.

Animals↗
PubMed2000

Involvement of inorganic polyphosphate in expression of SOS genes.

Inorganic polyphosphate (poly(P)) is a linear polymer that has been found in every organism so far examined. To elucidate the functions of poly(P) in the regulation of gene expression, the level of cellular poly(P) in Escherichia coli was reduced to a barely detectable concentration by overproduction of exopolyphosphatase (exopoly(P)ase) with a plasmid encoding yeast exopoly(P)ase (Shiba et al., Proc. Natl. Acad. Sci. USA 94 (1997) 11210-11215). It was found that exopoly(P)ase-overproducing cells were more sensitive to UV or mitomycin C (MMC) than were control cells. Poly(P) accumulation was observed after treatment with MMC, whereas the poly(P) level was below the detectable level in cells that overproduced exopoly(P)ase. When exopoly(P)ase-overproducing cells were transformed again by a multiple copy number plasmid that carries the polyphosphate kinase gene (ppk), the cells accumulated a great amount of poly(P) and restored the UV and MMC sensitivities to the level of control cells. In exopoly(P)ase-overproducing cells, the expression of recA and umuDC were not induced by MMC. In addition, a strain containing multiple copies of ppk accumulated not only a large amount of poly(P) but also recA mRNA. Since recA expression was induced in a recA-deletion strain harboring a plasmid with the ppk gene, poly(P) could be necessary for regulating the expression of SOS genes without depending on the RecA-LexA regulatory network.

Acid Anhydride Hydrolases↗
PubMed2000

Caspase-9 regulates cisplatin-induced apoptosis in human head and neck squamous cell carcinoma cells.

The aim of this study was to understand the molecular requirements for cisplatin-induced apoptosis in human head and neck squamous cell carcinoma (HNSCC) cell death. Cisplatin induced apoptosis in HNSCC cell lines, HSC-2, HSC-3 and HSC-4 in a dose-dependent manner. However, cisplatin did not induce the expression of Fas-ligand mRNA or upregulation of Fas protein. By caspase activation assays, cisplatin induced Caspase-3 (Casp-3), -8 and -9 activation. In all three lines tested, the use of a specific inhibitor of Casp-9 almost completely blocked cisplatin-induced apoptosis, while the use of Casp-3 and -8 inhibitors resulted in a partial blockade of cisplatin-induced apoptosis. Our results strongly suggest that Casp-9-dependent apoptosis plays an important role in cisplatin-induced HNSCC apoptosis.

Apoptosis↗
PubMed2000

Efficacy of autologous platelet-rich plasma in thoracic aortic aneurysm surgery.

OBJECTIVE: Allogenic blood transfusion can transmit viral infection or cause immunological side effects. Recently, improved operative techniques have required less frequent transfusions in thoracic aortic aneurysm surgery. This study examined the efficacy of using autologous platelet-rich plasma in thoracic aortic aneurysm surgery. METHOD: Eight patients underwent nine operations using an autologous platelet-rich plasma program. The control group consisted of 15 historic patients matched for operative procedure and age. All operations were performed by the same surgeon. The platelet-rich plasma program required the collection of platelet-rich plasma prior to the infusion of heparin; platelet-rich plasma transfusions were administered following neutralization by heparin. RESULTS: The volume of platelet-rich plasma averaged 252 +/- 14.3 ml; total platelets in the platelet-rich plasma were 2.27 +/- 0.20 x 10(11) cells. The median number of homologous red blood cells transfused during the operative day was 0 units (range 0 to 12) in the platelet-rich plasma group and 3 units (range 0 to 25) in the controls. The median number of homologous fresh frozen plasma was 0 units (range 0 to 20) in the platelet-rich plasma group, and 5 units (range 0 to 30) in the controls. The platelet-rich plasma group received significantly fewer transfusions. CONCLUSION: Autologous platelet-rich plasma transfusion was an effective way to reduce homologous blood transfusions in thoracic aortic aneurysm surgery.

Adult↗
PubMed2000

The lipoprotein lipase activator, NO-1886, suppresses fat accumulation and insulin resistance in rats fed a high-fat diet.

AIMS/HYPOTHESIS: Fat balance is critical in the aetiology of obesity and related diseases. Lipoprotein lipase is of major importance in lipid metabolism. The aim of this study was to investigate the long-term effects of the lipoprotein lipase activator, NO-1886, on substrate utilisation, adiposity and insulin action in rats fed a high-fat diet. METHODS: Male, Sprague-Dawley rats were fed for 10 weeks on a chow diet or a high-fat diet with, or without, NO-1886 (50 mg x kg(-1) x day(-1)). Weight gain, fat accumulation and both hormone-sensitive and lipoprotein, lipase activities were measured. Insulin action was assessed by the euglycaemic hyperinsulinaemic clamp and metabolic rate/substrate utilisation by open-circuit respirometry. RESULTS: Compared with chow-fed controls, a high-fat diet increased weight gain, an effect lessened by NO-1886 [weight gain (g): chow, 37 +/- 3, high-fat, 222 +/- 9; high-fat + NO-1886, 109 +/- 6, all groups differed p < 0.001]. A similar pattern existed for fat accumulation [visceral fat (g): chow, 35.9 +/- 3.2; high-fat, 81.9 +/- 6.6; high-fat + NO-1886, 52.3 +/- 4.7, p < 0.01 high-fat vs the other groups]. A high-fat diet induced wholebody insulin resistance (clamp glucose infusion rate: 4.8 +/- 1.3 mg x kg(-1) x min(-1) vs 10.6 +/- 1.1 for the chow group, p < 0.01) with NO-1886 lessening this effect (8.3 +/- 0.5, p < 0.05 vs high-fat). The 24-h respiratory quotient was lower in the high-fat + NO-1886 group (0.825 +/- 0.010) compared with high-fat alone (0.849 +/- 0.004, p < 0.05). A high-fat diet increased lipoprotein and hormone-sensitive, lipase activities in epididymal fat, an effect not altered by NO-1886. In myocardium and skeletal muscle a high-fat diet lowered lipoprotein lipase activity, an effect lessened by NO-1886. CONCLUSION/INTERPRETATION: Lipoprotein lipase activators could have potential benefits for the treatment of obesity by increasing fat utilisation.

Adipose Tissue↗
PubMed2000

Pulmonary thromboembolism after surgery for esophageal cancer: its features and prophylaxis.

We attempt to clarify the problems of pulmonary thromboembolism (PTE), which occurs less frequently in Japan than in the West, regarding its special perioperative management and prophylaxis for PTE after esophagectomy. We studied 26 patients with PTE following esophagectomy among 1023 patients with esophageal cancer between 1984 and 1997. The presence of embolism was confirmed by pulmonary perfusion scintigraphy. The incidence, diagnosis, and other issues of PTE were all reviewed. The incidence of PTE was 2.5%, with patients showing a biphasic early and late onset. The main symptoms were dyspnea in 19 patients and tachycardia in 17. Scintigraphy demonstrated 154 lesions, 35.7% of which were located in the left lower lobe and 25.3% in the right lower lobe. Treatment mainly consisted of the administration of heparin and urokinase. Four of the 26 patients died. Intermittent pneumatic compression (IPC) with the administration of heparin has been used in our department since 1994 to prevent PTE and this has also helped to decrease the incidence from 3.2% to 0.7%. Because the incidence of PTE following esophagectomy is higher than expected, PTE should be considered whenever hypoxemia of some unknown cause is found. Both early diagnosis and treatment are essential. It is also important to prevent PTE by the use of IPC.

Esophageal Neoplasms↗