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Biomedical subjects

S Saeki

Publications and source records attributed to S Saeki.

At least 37 records · Page 2Linked to original sources
PubMed2000

The Ras-MAPK pathway is important for olfaction in Caenorhabditis elegans.

The Ras-MAPK (mitogen-activated protein kinase) signal transduction pathway is well known to control cellular proliferation and differentiation in response to extracellular signals, but its other functions are less understood. In Caenorhabditis elegans this pathway regulates several developmental events, such as vulval induction and progression of meiosis, but its function in the nervous system is unknown. Here we report that the Ras-MAPK pathway is involved in olfaction in this organism. Mutational inactivation and hyperactivation of this pathway impairs efficiency of chemotaxis to a set of odorants. Experiments in which let-60 ras was expressed using a heat-shock promoter and a cell-specific promoter show that a normal activity of LET-60 Ras is required in mature olfactory neurons. Application of the odorant isoamylalcohol to wild-type animals leads to the activation of MAP kinase in olfactory neurons within 10 seconds. This induction is dependent on the function of the nucleotide-gated channel TAX-2/TAX-4 and the voltage-activated calcium channel subunit UNC-2. These results suggest a dynamic regulatory role for the Ras-MAPK pathway in perception and transmission of sensory signals in olfactory neurons.

Animals↗
PubMed2000

Duration of exposure to sevoflurane affects dose-response relationship of vecuronium.

The purpose of this study was to quantify the relationship between the dose-response curve of vecuronium and duration of exposure to an end-tidal concentration of 1.7% sevoflurane in 67% nitrous oxide and oxygen. Forty adult patients, in groups of 10, were allocated randomly to receive vecuronium by a cumulative dose method at intervals of 15 min (group 15), 30 min (group 30), 60 min (group 60) or 90 min (group 90) after starting inhalation of sevoflurane. Neuromuscular function was monitored by acceleromyographic train-of-four (TOF) responses of the adductor pollicis muscle to ulnar nerve stimulation. Dose-response curves were constructed by least-squares regression analysis and the effective doses of vecuronium (ED50, ED90 and ED95) were estimated and compared between groups. Mean (SEM) ED50, ED90 and ED95 were 16.8 (0.5), 32.6 (1.7) and 40.9 (2.4) micrograms kg-1, respectively, in group 15; 10.6 (1.0), 20.8 (1.7) and 26.2 (2.2) micrograms kg-1, respectively, in group 30; 11.2 (1.1), 21.7 (1.6) and 27.3 (1.8) micrograms kg-1, respectively, in group 60; and 11.0 (1.1), 21.7 (1.6) and 27.5 (1.9) micrograms kg-1, respectively, in group 90. The values obtained in group 15 were significantly higher than those in the other three groups (P < 0.05). The results indicate that the duration of sevoflurane anaesthesia influences the dose-response of vecuronium and 30 min inhalation of 1.7% end-tidal concentration is sufficient to achieve a stable potentiating effect.

Adult↗
PubMed2000

Conditionally immortalized brain capillary endothelial cell lines established from a transgenic mouse harboring temperature-sensitive simian virus 40 large T-antigen gene.

Five immortalized brain capillary endothelial cell lines (TM-BBB1-5) were established from 3 transgenic mice harboring temperature-sensitive simian virus 40 large T-antigen gene (Tg mouse). These cell lines expressed active large T-antigen and grew well at 33 degrees C with a doubling time of about 20 to 30 hours. TM-BBBs also grew at 37 degrees C but not at 39 degrees C. However, growth was restored when the temperature of the culture was lowered to 33 degrees C. Although significant amounts of large T-antigen were shown to be present in the cell culture at 33 degrees C, there was less of this complex at 37 degrees C and 39 degrees C. TM-BBBs expressed the typical endothelial marker, von Willebrand factor, and exhibited acetylated low-density lipoprotein uptake activity. The alkaline phosphatase and gamma-glutamyltranspeptidase activity in TM-BBBs were -10% and 50% to 80% of brain capillary fraction of normal mice, respectively. D-mannitol transport in the both apical-to-basal and basal-to-apical directions across the TM-BBB was 2-fold greater than for inulin. TM-BBBs were found to express GLUT-1 but not GLUT-3, and exhibited concentration-dependent 3-O-methyl-D-glucose (3-OMG) uptake activity with a Michaelis-Menten constant of 6.59 +/- 1.16 mmol/l. Moreover, P-glycoprotein (P-gp) with a molecular weight of -170 kDa was expressed in all TM-BBBs. Both mdr1a and mdr1b mRNA were detected in TM-BBB4 using reverse transcription-polymerase chain reaction (RT-PCR) analysis. [3H]-Cyclosporin A uptake by TM-BBB was significantly increased in the presence of 100 micromol/l verapamil and vincristine, suggesting that TM-BBB exhibits efflux transport activity via P-gp. In conclusion, conditional brain capillary endothelial cell lines were established from Tg mice. This cell line expresses endothelial markers and transporters at the BBB and is able to regulate cell growth, due to the amount of active large T-antigen in the cell, by changing the culture temperature.

3-O-Methylglucose↗
PubMed2000

Improved hypolipidemic effects of xanthan gum-galactomannan mixtures in rats.

This study describes the effects of mixtures of xanthan gum and galactomannan, guar gum, or locust bean gum, on the lipids in plasma and liver in non-diabetic and diabetic rats. Non-diabetic rats were fed cholesterol-free diets with 3% guar gum, locust bean gum, or xanthan gum (3G, 3L, and 3X), or a mixture of xanthan gum and guar gum or locust bean gum (1:2, w/w) (2G1X, 2L1X) for 2 weeks. Rats fed diets not containing these polysaccharides were used as controls. The total cholesterol in plasma and the triacylglycerol in liver were significantly lowered in rats fed the 2G1X diet. The 3G, 3X, 3L, and 2L1X diets showed no significant effect on the total cholesterol and triacylglycerol in plasma and liver. In the streptozotocin-induced (STZ) diabetic rats, the total cholesterol in plasma was lowered in rats fed the 3G, 3X or 2G1X diet for 4 weeks, and the 2G1X diet was more effective than the 3G and 3X diets. The triacylglycerol in plasma in STZ diabetic rats was also significantly lowered by the 2G1X diet. These results showed that a mixture of xanthan gum and guar gum has an improved hypolipidemic effect on non-diabetic and STZ diabetic rats. The effects of the 2G1X diet on the diabetic symptoms in STZ diabetic rats, suppression of food and water intakes, decrease in glucose in urine, and lowering of plasma glucose, were also observed.

Animals↗
PubMed2000

[Anesthetic management for a patient with spondyloepiphyseal dysplasia congenita].

An 11-year-old girl with spondyloepiphyseal dysplasia congenita in the spine was scheduled for virectomy under general anesthesia. She had slight scoliosis in the thoracic and lumbar spine, moderate funnel chest and slight thoracic kyphosis. Preoperative laboratory data were within normal range and her intelligence was normal. Her Mallanpathi's score, however, was Grade 3 and effective mandibular length/posterior depth of mandible ratio was 3.48 on the lateral view of head X-ray. From these data, difficult intubation was expected. Although anesthesia was induced uneventfully using thiamylal and vecuronium, her vocal cord was not visualized under laryngoscope. Using cricoid pressure procedure, slightly left-shifted vocal cord was exposed. However a 26 Fr. size endotracheal tube without cuff was too large and finally a 22 Fr. tube was inserted. During the operation patient's general condition was stable and the operation was finished without any episodes. She did not have any complications in the postoperative period. In a case of SDC, pathological changes in laryngotracheal resion should be examined and evaluated preoperatively and difficult intubation should also be always taken into account.

Anesthesia, General↗
PubMed2000

[Preoperative questionnaire survey about anxiety of patients for scheduled operation].

Preoperative patients have various kinds of anxiety. However we do not know much about their psychological burden. Therefore, we investigated types of their anxiety with questionnaires prior to operation and analyzed them according to their anesthetic method, type of surgery and age. Concerning anesthetic methods, patients' anxiety varied depending on their histories of anesthesia, anesthetic method previously received and age. Concerning the type of surgery, patients scheduled to undergo abdominal and cardiac surgery had more intense anxiety. Patients scheduled for gynecological surgery were anxious about the accident which might be induced by anesthesia. A large number of patients scheduled for orthopedic surgery were anxious about postoperative pain. Concerning patients' age, patients whose ages ranged from 10s to 50s were anxious about pain. While, in patients over 60s, their anxiety was focussed on giving trouble to their surrounding people. Patients whose age was 10 to 19 had anxiety about their anesthetic method. Anesthesiologists should recognize that preoperative patients have various kinds of anxiety. It is important for us to examine the patients appropriately according to their psychological and physical condition.

Adolescent↗
PubMed1999

Gender-related differences in scores of the Barthel Index and Frenchay activities index in randomly sampled elderly persons living at home in Japan.

The purpose of this study was to examine for gender-related differences in activities of daily living (ADL) and lifestyle of elderly persons living at home, and to support our hypothesis that the gender-related difference in lifestyle of stroke patients derives from their lifestyle prior to the stroke. Participants were randomly sampled elderly persons living at home. Questionnaire sheets including subject profile, Self-Rating Barthel Index (disability index), and Self-Rating Frenchay Activities Index (activity index) were mailed and collected, and the data were analyzed with the t-test and General Linear Model (factorial model with interaction). A total of 752 subjects were recruited, and their average age was 67.1 years. No significant gender-related differences were evident in the disability index including self-care and mobility domains (t-test, P > 0.05). In contrast gender-related differences in the activity index were significant (t-test, P < 0.05) for three factors; gender, age group, and living conditions, and in a covariate disability index (GLM, P < 0.05). Because randomly selected elderly persons in this study exhibited a prominent gender-related difference in lifestyle, we believe the lifestyle difference in stroke patients that we have previously described derives primarily from their premorbid attitude to daily life.

Activities of Daily Living↗
PubMed1999

In vitro digestibility and fermentability of levan and its hypocholesterolemic effects in rats.

This study describes the in vitro digestibility and fermentability of high molecular weight (ca. 2,000,000) levan and its effect on the metabolism of lipids in growing rats fed cholesterol-free diets. Levan was synthesized from sucrose using bacterial levansucrase immobilized on a honeycomb-shaped ceramic support. Although body weight gain, weight of visceral organs, morphologic changes in the digestive tract, and the serum triacylglycerol and glucose concentrations were not affected by feeding levan diets for 4 weeks, a significant hypocholesterolemic effect was observed. Serum cholesterol level was decreased to 83% or 59% by feeding a 1% or 5% levan diet, respectively. The hypocholesterolemic effect was accompanied by a significant increase in fecal excretion of sterols and lipids. High molecular weight levan, though not hydrolyzed by the salivary amylases, was hydrolyzed by artificial gastric juice and was changed to a low molecular weight (ca. 4,000) levan with a small amount of fructose, but did not produce any fructooligosaccharides. Low molecular weight (ca. 6,000) levan was not hydrolyzed by either pancreatic juice or small intestinal enzymes. This suggests that, in vivo, low molecular weight levan derived from the high molecular weight material is not further digested and reaches the colon intact. The fermentation of low molecular weight levan (ca. 6,000) by several strains of bifidobacteria was not observed. These results showed that the hypocholesterolemic effect of levan may result from the prevention of intestinal sterol absorption, and not from the action of the fermentation products of levan.

Journal Article↗
PubMed1999

Augmentation of vecuronium-induced neuromuscular block during sevoflurane anaesthesia: comparison with balanced anaesthesia using propofol or midazolam.

We have quantified the potentiating effects of 1.7% sevoflurane (n = 12) on vecuronium-induced neuromuscular block and compared the results with those obtained during balanced anaesthesia with propofol (n = 12) or midazolam (n = 12) in 36 patients. Neuromuscular function was monitored using an accelerograph and the train-of-four responses of the adductor pollicis muscle to ulnar nerve stimulation. Vecuronium 0.1 mg kg-1 was administered as an intubating dose, and maintenance doses of 0.02 mg kg-1 were administered on three occasions when T1/T0 had recovered to 25%. Thereafter, spontaneous recovery was monitored until complete. Times to 25% recovery of T1/T0 (DUR25) after an intubating dose of vecuronium did not differ between groups (mean 44.2 (SD 18.7) min for sevoflurane, 38.3 (7.5) min for propofol and 35.5 (9.5) min for midazolam). DUR25 values after each maintenance dose were 29.8 (9.5) min, 30.3 (10.4) min and 31.6 (10.7) min during sevoflurane anaesthesia, and were significantly longer than values for propofol (21.7 (6.0) min, 21.5 (5.8) min and 21.9 (5.8) min) and midazolam (20.0 (5.9) min, 19.3 (7.7) min and 19.8 (8.0) min) (P < 0.05) in each case). Recovery index25-75% and interval from T1/T0 = 25% to T4/T1 = 0.7 after the final dose of vecuronium were significantly prolonged by sevoflurane (28.3 (13.2) min and 42.7 (16.4) min) compared with propofol (17.6 (6.1) min and 26.6 (9.8) min) or midazolam (16.3 (9.4) min and 26.0 (10.2) min) (P < 0.05 in each case).

Adult↗
PubMed1999

Teas and other beverages suppress D-galactosamine-induced liver injury in rats.

We compared the effects of various types of beverages (teas, coffee, and cocoa) on D-galactosamine-induced liver injury by measuring plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities in 7-wk-old male Wistar rats. The effects of five fractions extracted with different organic solvents from green tea, different types of dietary fibers, and some short chain fatty acids were also investigated. All of the beverages tested significantly suppressed D-galactosamine-induced enhancement of plasma enzyme activities when powdered beverages were added to the diet (30 g/kg) and fed to rats for 2 wk. Plasma ALT activities were 1155 +/- 82 [micromol/(min.L), control], 289 +/- 61 (green tea), 626 +/- 60 (roasted green tea), 471 +/- 84 (puerh tea), 676 +/- 69 (oolon tea), 423 +/- 76 (black tea), 829 +/- 53 (coffee), and 885 +/- 89 (cocoa). The profile of AST activities was similar. The caffeine-containing fraction from green tea had no significant effect, whereas the other four fractions, including the soluble fiber fraction, significantly suppressed liver injury. In addition to tea fibers, many other types of dietary fiber (hemicellulose, chitin, chitosan, alginate, pectin, guar gum, glucomannan, and inulin, but not cellulose) had liver injury-preventive effects when added to the diet (30 g/kg), suggesting that liver injury-prevention may be one of the general effects of dietary fibers. Of three short-chain fatty acids tested (acetate, propionate, and butyrate), only acetate prevented liver injury when added to the diet (15 g/kg), supporting the possibility that the liver injury-preventive effect of dietary fibers may be mediated at least in part by certain organic acids. These results suggest that several beverages possess preventive effects on certain types of liver injury, such as that induced by D-galactosamine, and that different constituents of high and low molecular weights contribute to the liver injury-preventive effects of green tea.

Alanine Transaminase↗
PubMed1998

Functional disabilities of disabled workers in vocational aid facilities and a social welfare factory.

We evaluated functional disabilities of disabled workers at vocational aid facilities and a social welfare factory to reveal whether evaluation of the functional disabilities is useful for occupational health care activities. Subjects were 121 persons with a physical disability working at Fukuoka Colony (FC workers) and 35 persons with mental retardation working at Nanomi Kogei (NK workers). The Self-Rating Barthel Index, Self-Rating Frenchay Activities Index, and Satisfaction in Daily Life (SDL) were used for the evaluation of basic activities of daily living (ADL), lifestyle, and subjective domain of quality of life, respectively. The FC workers were almost independent in basic ADL: had a high capability in self-care activities and moderately disturbed capability in mobility activities, and had a more active lifestyle than the NK workers. The total SDL score indicated that the FC workers were less satisfied with overall daily life, although not significant, and were less satisfied with the SDL items of physical health, gait, house facilities, and having a job than the NK workers. Because these results indicated the features of disabled workers and gave an occupational health physician valuable information about disabilities, the evaluations used in this study can be regarded as useful for occupational health care activities.

Activities of Daily Living↗
PubMed1998

cDNA cloning of a new low-density lipoprotein receptor-related protein and mapping of its gene (LRP3) to chromosome bands 19q12-q13. 2.

We report herein the cDNA cloning of a novel member of the low-density lipoprotein receptor (LDLR) family termed LDLR-related protein 3 (LRP3). Human and rat LRP3 cDNAs encode a 770-amino-acid type 1 membrane protein with the following regions: a putative signal sequence, two isoleucine/leucine/valine-rich regions with an RGD sequence, two ligand-binding repeat regions, a putative transmembrane region, and a proline-rich cytoplasmic region with a tyrosine-based internalization signal. Fluorescence in situ hybridization of human chromosomes revealed that the human LRP3 gene mapped to chromosome bands 19q12-q13.2. LRP3 transcript was detected in a wide range of human tissues, with the highest expression in skeletal muscle and ovary. Despite the presence of the ligand-binding repeats, CHO cells transfected with LRP3 did not bind beta-migrating very-low-density lipoprotein or receptor-associated protein.

Amino Acid Sequence↗
PubMed1998

Dietary methionine level affects linoleic acid metabolism through phosphatidylethanolamine N-methylation in rats.

The effects of dietary methionine level on the profiles of fatty acids and phospholipids and on the plasma cholesterol concentration were investigated to confirm whether the methionine content of dietary proteins is one of the major factors that cause differential effects on lipid metabolism. The effect of dietary supplementation with eritadenine, which is shown to be a potent inhibitor of phosphatidylethanolamine (PE) N-methylation, was also investigated. Rats were fed six diets containing casein (100 g/kg) and amino acid mixture (86.4 g/kg) differing in methionine content (2.5, 4.5, and 7.5 g/kg) and without or with eritadenine supplementation (30 mg/kg) for 14 d. The ratio of arachidonic to linoleic acid of liver microsomal and plasma phosphatidylcholine (PC) was significantly increased as the methionine level of diet was elevated, indicating that dietary methionine stimulates the metabolism of linoleic acid. The PC/PE ratio of liver microsomes and the plasma cholesterol concentration were also increased by dietary methionine. These effects of methionine were completely abolished by eritadenine supplementation The S-adenosylmethionine concentration in the liver reflected the methionine level of diet. These results support the idea that the differential effects of dietary proteins on lipid metabolism might be ascribed, at least in part, to their different methionine contents, and that methionine might exert its effects through alteration of PE N-methylation.

Adenine↗
PubMed1998

Factors affecting the variability of the torque curves at isokinetic trunk strength testing.

OBJECTIVES: To evaluate the relation between variability of the torque curves and factors such as age, gender, measurement speeds, and period from low back pain (LBP) onset at isokinetic trunk strength testing. DESIGN: Observational. SETTING: Hospital. PATIENTS: One hundred forty-three consecutive LBP patients (acute, subacute, and chronic) who received physical therapy, and 200 healthy volunteer subjects. MAIN OUTCOME MEASURES: The variability of the torque curves is an indicator of consistency of effort, and was measured as the coefficient of variance (CV) at different measurement speeds in isokinetic trunk flexion/extension strength testing. RESULTS: The CV was lower in men than in women at the faster measurement speed. LBP patients had higher CV values than healthy subjects. The CV was different according to gender and measurement speed, but not different according to age and periods from LBP onset. CONCLUSION: The CV was affected by measurement speed and gender, but not by age or period from LBP onset. Because the CV was higher in LBP patients than in healthy subjects, this value may be usable as an adjunctive index of LBP.

Abdomen↗
PubMed1998

Diurnal variation in tooth movement in response to orthodontic force in rats.

The purpose of this study was to determine whether there is any difference in orthodontic tooth movement when the orthodontic force is applied at different times of the day. Twenty-four rats were divided into three experimental groups based on the time of day that maxillary expansive force was applied; i.e., the force was applied continuously throughout the entire experimental period of 21 days in animals in the whole-day group; animals in the dark-period group and the light-period group received force only during the dark period (19:00-07:00) or the light period (07:00-19:00), respectively. Maxillary expansion in the light-period group was about 2 times greater than that in the dark-period group on day 21. There was no significant difference in expansion between the light-period group and the whole-day group. An experiment that used chronologic labeling with NTA-Pb revealed that there was greater formation of new bone on the tension side in the light-period group than in the dark-period group. There was no significant difference in the width of the palate among the three groups. These results indicate that there is a diurnal variation in tooth movement in response to orthodontic external force and that the application of force during the animal's rest period may be more effective than that while it is active.

Analysis of Variance↗
PubMed1998

Evolution of the apolipoprotein E receptor 2 gene by exon loss.

The apolipoprotein E receptor 2 (apoER2) gene consists of a mosaic of exons, which may have been assembled by "exon shuffling." Analysis of apoER2 transcripts in several species reveals a lost repeat in the ligand-binding domain of primate apoER2. A pseudo-exon found in the primate apoER2 genes corresponds to the lost repeat but contains a crucial deletion that leads to a translational frameshift. The pseudo-exon sequence in primary transcripts of the human apoER2 gene is shown to be abolished by exon skipping due to two nucleotide substitutions at the 5'-splice donor adjacent to the pseudo-exon. These data suggest the occurrence of exon loss in the evolution of the primate apoER2 gene.

Amino Acid Sequence↗