Biomedical subjects

T Matsuo

Publications and source records attributed to T Matsuo.

At least 73 records · Page 4Linked to original sources

PubMed2001

Nitrous oxide production in high-loading biological nitrogen removal process under low COD/N ratio condition.

Effects of influent COD/N ratio on N2O emission from a biological nitrogen removal process with intermittent aeration, supplied with high-strength wastewater, were investigated with laboratory-scale bioreactors. Furthermore, the mechanism of N2O production in the bioreactor supplied with low COD/N ratio wastewater was studied using 15N tracer method, measuring of reduction rates in denitrification pathway, and conducting batch experiments under denitrifying condition. In steady-state operation, 20-30% of influent nitrogen was emitted as N2O in the bioreactors with influent COD/N ratio less than 3.5. A 15N tracer study showed that this N2O originated from denitrification in anoxic phase. However, N2O reduction capacity of denitrifiers was always larger than NO3(-)-N or NO2(-)-N reduction capacity. It was suggested that a high N2O emission rate under low COD/N ratio operations was mainly due to endogenous denitrification with NO2(-)-N in the later part of anoxic phase. This NO2(-)-N build-up was attributed to the difference between NO3(-)-N and NO2(-)-N reduction capacities, which was the feature observed only in low COD/N ratio operations.

Bioreactors↗

PubMed2001

De novo acute myeloid leukemia in the elderly; a consistent fraction of long-term survivors by standard-dose chemotherapy.

To clarify the characteristics of de novo acute myeloid leukemia (AML) among the elderly, we reviewed 112 patients over 60 years old (median age 72 years) who were treated at hospitals in Nagasaki Prefecture with a population of 1.5 million between 1987 and 1994. Reclassification of morphological diagnosis revealed that the proportion of M3 was lower but that of M6 and the incidence of cases with trilineage dysplasia (TLD), known as poor prognostic features, were higher in the elderly than in patients less than 60 years old. Similarly, chromosomal data showed a lower frequency of favorable karyotypes such as t(8;21) and t(15;17) in the elderly. The overall survival of all 112 patients was 10.3% at 5 years. Multivariate analysis indicated that good performance status (PS), low WBC at diagnosis, standard dose multi-drug chemotherapy and all-trans retinoic acid (ATRA) treatment for M3 patients, and morphological findings without TLD were significantly correlated with longer survival. Most of the long-term survivors were found among those who received standard dose therapy in this series, although no consensus has been established how to treat elderly AML patients. We propose that a prospective controlled trial is necessary to confirm the role of standard dose chemotherapy for elderly patients with de novo AML.

Acute Disease↗

PubMed2001

Silent and clinically overt stroke in older Japanese subjects with white-coat and sustained hypertension.

OBJECTIVES: We investigated whether white-coat hypertension is a risk factor for stroke in relation to silent cerebral infarct (SCI) in an older Japanese population. BACKGROUND: It remains uncertain whether white-coat hypertension in older subjects is a benign condition or is associated with an increased risk of stroke. METHODS: We studied the prognosis for stroke in 958 older Japanese subjects (147 normotensives [NT], 236 white-coat hypertensives [WCHT] and 575 sustained hypertensives [SHT]) in whom ambulatory blood pressure monitoring was performed in the absence of antihypertensive treatment. In 585 subjects (61%), we also assessed SCI using brain magnetic resonance imaging. RESULTS: Silent cerebral infarcts were found in 36% of NT (n = 70), 42% of WCHT (n = 154), and 53% of SHT (n = 361); multiple SCIs (the presence of > or =2 SCIs) were found in 24% of NT, 25% of WCHT and 39% of SHT. During a mean 42-month follow-up period, clinically overt strokes occurred in 62 subjects (NT: three [2.0%]; WCHT: five [2.1%]; SHT: 54 [9.4%]), with 14 fatal cases (NT: one [0.7%]; WCHT: 0 [0%]; SHT: 13 [2.3%]). A Cox regression analysis showed that age (p = 0.0001) and SHT (relative risk, [RR] [95% confidence interval, CI]: 4.3 [1.3-14.2], p = 0.018) were independent stroke predictors, whereas WCHT was not significant. When we added presence/absence of SCI at baseline into this model, the RR (95% CI) for SCI was 4.6 (2.0-10.5) (p = 0.003) and that of SHT was 5.5 (1.8-18.9) versus WCHT (p = 0.004) and 3.8 (0.88-16.7) versus NT (p = 0.07). CONCLUSIONS: In older subjects the incidence of stroke in WCHT is similar to that of NT and one-fourth the risk in SHT. Although SCI is a strong predictor of stroke, the difference in stroke prognosis between SHT and WCHT was independent of SCI. It is clinically important to distinguish WCHT from SHT even after assessment of target organ damage in the elderly.

Aged↗

PubMed2001

4-(Methylthio)-3-butenyl isothiocyanate, a principal antimutagen in daikon (Raphanus sativus; Japanese white radish).

The antimutagenic activity of n-hexane extracts from eight strains of daikon (Raphanus sativus; Japanese white radish) have been examined using the UV-induced mutation assay of Escherichia coli B/r WP2. A correlation was found between the potency of antimutagenicity and the amount of 4-(methylthio)-3-butenyl isothiocyanate (MTBITC) in their n-hexane extracts. Because the pure MTBITC also showed antimutagenicity, MTBITC is presumably the active antimutagen principle in n-hexane extracts of daikon. Among the eight strains of daikon studied, Aokubi, the improved common strain in Japan, contained 71.0 micromol of MTBITC in 100 g of fresh daikon. In contrast, Karami and Momoyama, which are original wild strains, contained much more MTBITC (363.5 and 168.0 micromol/100 g, respectively). In addition, phenethyl isothiocyanate was found in a lesser amount (5-33 nmol/100 g) in eight strains of daikon, and allyl isothiocyanate and benzyl isothiocyanate were not detectable in any strains (<3 nmol/100 g). The amount of total isothiocyanate in grated daikon was 7.0 times higher than that in cut daikon measured after 30 min of cooking. Through eating habits, humans might be able to consume substantial amounts of the antimutagen MTBITC from dishes using the grated form of wild strains of daikon. Therefore, it is possible to substantially increase the intake of the antimutagenic ingredient of daikon (i.e., MTBITC) by changing food preferences and preparation procedures (i.e., using the grated form of the wild strains).

Antimutagenic Agents↗

PubMed2001

Application of the gene search system to screen for longevity genes in Drosophila.

We have developed a strategy using Drosophila as a model system to identify genes that are crucial for extension of longevity. A collection of transgenic lines with a P-element based gene search (GS) vector containing UAS (Upstream Activating Sequence) was screened for longevity in combination with an hsp70 promoter-driven GAL4 transgene. Misexpression of the vector-flanking sequence was induced throughout the adult stage to assess its effects on the aging process rather than development. We showed that the longevity was greatly affected by GS inserts, and it was positively correlated with paraquat resistance. Of 646 GS inserts, we selected 23 inserts with relatively longer longevity for further molecular analysis. All of the misexpressed sequences matched either known genes or ESTs (Expressed Sequence Tags). Among 13 genes whose functions are already known or suggested, six were related to stress resistance or redox balance (DmGST2, hsp26, nla, and Drosophila homologs of mammalian TRX, GILT and POSH), suggesting the importance of stress resistance for the extension of longevity. This is the first demonstration that a systematic gain-of-function screen could efficiently detect longevity genes.

Animals↗

PubMed2001

Neural-specific overexpression of drosophila plenty of SH3s (DPOSH) extends the longevity of adult flies.

Extended longevity mutants are extremely useful to understand the molecular mechanism of longevity determination. Here we report identification and characterization of the Drosophila Plenty of SH3s (DPOSH) gene, a candidate that might be associated with the extended longevity phenotype. DPOSH encodes a protein containing a RING finger domain and four SH3 domains. We showed that neural-specific overexpression of DPOSH could extend the mean longevity of adult flies by 14% at 25 degrees C without affecting viability or morphology. In contrast, forced expression of DPOSH in developing imaginal discs produced various phenotypes including lethality and morphological defects such as loss of crossvein, notched wing, and disordered hair polarity. Puckered, a target gene of JNK/SAPK pathway, was activated by overexpression of DPOSH and the forced expression phenotypes were suppressed by introducing a mutation of Drosophila JNK (bsk) or JNKK (hep), suggesting that the JNK/SAPK signaling pathway is one of the critical elements in the determination of longevity.

Adaptor Proteins, Signal Transducing↗

PubMed2001

Cloning and expression of the ferredoxin gene from extremely halophilic archaeon Haloarculajaponica strain TR-1.

The gene encoding a ferredoxin (Fd) from Haloarculajaponica strain TR-1 was cloned and sequenced. Sequence analysis of the cloned Ha. japonica Fd gene revealed that the structural gene consisted of an open reading frame of 387 nucleotides encoding 129 amino acids. The deduced amino acid sequence of Ha. japonica Fd showed 84 to 98% identity with corresponding sequences in other extremely halophilic archaea. The Ha. japonica Fd gene was inserted into the shuttle vector pWL102 and used to transform Ha. japonica. Ha. japonica Fd could then be produced as a fusion with His-Tag (6xHis) in Ha. japonica host cells. The absorption and ESR spectra of the Fd/His Tag fusion protein revealed the presence of a [2Fe-2S] cluster which is characteristic of native Ha. japonica Fd.

Amino Acid Sequence↗

PubMed2001

Soluble products from Eikenella corrodens stimulate oral epithelial cells to induce inflammatory mediators.

In the inflammatory response elicited by bacterial colonization in periodontal pockets, pocket epithelial cells not only serve as a barrier to isolate the pocket microenvironment from external stimuli but also regulate the functions of neighboring cells including fibroblasts and inflammatory cells. To elucidate this mechanism, we characterized the effects of periodontopathic bacterium Eikenella corrodens 1073 components on the production of some inflammatory mediators in a human oral epithelial cell line (KB). In enzyme-linked immunosorbent assay (ELISA), the E. corrodens supernatant induced interleukin-6 (IL-6), IL-8 and prostaglandin E2 but not interferon-gamma (IFN-gamma) production by KB cells. After incubation with E. corrodens supernatant, KB cells showed a marked increase in the levels of IL-6, IL-8 and PG G/H synthase (cyclooxygenase)-2, but not IFN-gamma, gene expression by reverse-transcriptase polymerase chain reaction. All these E. corrodens products responsible for production of these inflammatory mediators resisted freezing and boiling and were present in a 10-kDa filtrate. These results imply that these soluble small-molecular-mass products from E. corrodens stimulate various inflammatory mediator productions by human oral epithelial cells and may play a role in the initiation of periodontal inflammation and subsequently perpetuate the inflammatory response during chronic infection.

Bacterial Adhesion↗

PubMed2001

Planned two-step vitrectomy for extremely large and thick subretinal hematoma.

PURPOSE: To describe a new surgical strategy, planned two-step vitrectomy, for a large and thick subretinal hematoma involving 3 or more quadrants of the fundus. SURGICAL METHODS: In a first-step vitrectomy, a retinotomy was made in the posterior pole, after any vitreous hemorrhage had been removed. Following fluid-gas exchange with no laser photocoagulation around the retinotomy, patients took a face-down position for a few days to a week to facilitate subretinal hemorrhage movement to the vitreous cavity and anterior chamber. In a second-step surgery, the hemorrhage in the vitreous cavity and anterior chamber was washed out. The remaining subretinal hemorrhage was aspirated, and the retina was reattached with fluid-gas exchange and laser photocoagulation around the retinotomy. RESULTS: The planned two-step vitrectomy was performed in 4 consecutive patients with large and thick subretinal hematomas involving 3 or more quadrants seen during a 3-year period. By a face-down position after the first-step vitrectomy, subretinal hemorrhage moved to the vitreous cavity and anterior chamber. The remaining subretinal hemorrhage in a smaller quantity could be easily removed, leading to retinal reattachment in the second-step surgery. CONCLUSIONS: The planned two-step vitrectomy is a safer and more effective procedure for removing a large quantity of subretinal hemorrhage in a shorter period of surgical time, compared with hemorrhage removal in a single vitrectomy.

Aged↗

PubMed2001

The PX domains of p47phox and p40phox bind to lipid products of PI(3)K.

PX domains are found in a variety of proteins that associate with cell membranes, but their molecular function has remained obscure. We show here that the PX domains in p47phox and p40phox subunits of the phagocyte NADPH oxidase bind to phosphatidylinositol-3,4-bisphosphate (PtdIns(3,4)P(2)) and phosphatidylinositol-3-phosphate (PtdIns(3)P), respectively. We also show that an Arg-to-Gln mutation in the PX domain of p47phox, which is found in patients with chronic granulomatous disease, eliminates phosphoinositide binding, as does the analogous mutation in the PX domain of p40phox. The PX domain of p40phox localizes specifically to PtdIns(3)P-enriched early endosomes, and this localization is disrupted by inhibition of phosphoinositide-3-OH kinase (PI(3)K) or by the Arg-to-Gln point mutation. These findings provide a molecular foundation to understand the role of PI(3)K in regulating neutrophil function and inflammation, and to identify PX domains as specific phosphoinositide-binding modules involved in signal transduction events in eukaryotic cells.

3T3 Cells↗

PubMed2001

Effect of a selective Abl tyrosine kinase inhibitor, STI571, on in vitro growth of BCR-ABL-positive acute lymphoblastic leukemia cells.

By employing a new semi-quantitative assay system that includes co-culturing leukemia cells with the mouse bone marrow-derived stromal cell line MS-5, we examined the suppressive effect of a selective inhibitor of ABL tyrosine kinase, STI571, on acute lymphoblastic leukemia (ALL) cells with BCR-ABL fusion. Leukemic blast cells from eight patients with B-precursor ALL, including three patients with BCR-ABL-positive ALL, were cultured on monolayers of MS-5 cells for 3 weeks with or without addition of variable amounts of STI571. In all cases, cobblestone areas (CAs) were formed, showing clear linear cell dose-dependent curves, allowing quantitative assessment of blast cell growth. The progenitor frequencies obtained by this direct CA-forming cell (CAFC) assay were equivalent to ALL progenitor frequencies assessed by the standard limiting dilution assay. The number of CAFCs ranged from 12.3 to 140.3/10(4) cells. In BCR-ABL-positive ALL patients, CA-containing cells were examined by FISH, and all contained BCR-ABL fusion genes. STI571 inhibited CA formation of BCR-ABL-positive ALL cells virtually 100% at 0.1-1.0 micromol/l. None of the five BCR-ABL-negative ALL patients showed this growth inhibition by STI571 at 0.1-1.0 micromol/l. Our results indicate that STI571 selectively inhibits in vitro growth of BCR-ABL-positive ALL cells.

Adolescent↗

PubMed2001

Severe dental open bite malocclusion with tongue reduction after orthodontic treatment.

We treated a 21-year-old woman with a severe open bite and macroglossia with a standard edgewise appliance and without partial glossectomy. This was followed by retention using a Begg-type plate retainer for the upper dental arch and a fixed canine-to-canine for the lower arch. A crib was added to the upper plate retainer for suppression of a tongue thrust. The lower arch relapsed during the retention period, with a widening of the intermolar distance, flaring of the anterior teeth, and increased mobility of the teeth. We chose tongue reduction to resolve these problems and one-third of the middle dorsal part of the tongue was excised. After the tongue reduction, the patient experienced no functional problem in mastication, swallowing, and gustation, but she complained of mild speech difficulty and slight pain on the dorsal portion of her tongue. These symptoms disappeared 6 months after surgery. At this time, the mandibular dental arch was markedly improved. The flared lower dental arch had returned to an upright position and the tooth mobility reduced to normal. No appliance was used after surgery. Most of the recovery changes occurred within 4 months. This case highlights the importance of the teeth tending to move toward a balance between the tongue pressure from the inside and labio-buccal pressure from the outside.

Adult↗

PubMed2001

Effects of plaque control on the patency and occlusion of dentine tubules in situ.

To elucidate the nature of dentine hypersensitivity, the effects of plaque control on the patency and occlusion of dentinal tubules were investigated systematically in situ using human dentine slabs embedded in partial dentures. The dentine slabs were divided into three groups. In group I, the dentine slabs were kept in an oral cavity without plaque control. In group II, plaque was removed mechanically by brushing. Plaque control was carried out chemically using chlorhexidine in group III. After being kept in the oral cavities for 1, 2 and 3 weeks, the slabs were removed from the partial denture, followed by SEM observation to determine the morphological changes of the dentinal tubules. When no attempt was made to remove plaque, the diameter of tubule orifices increased to 390% of the original values within 3 weeks. In contrast, dentinal tubules were found to be occluded, i.e. the tubule orifices became <20% of the original value within 1 week when plaque control efforts were made, using either method of plaque control. We conclude that plaque control plays one of the key roles in the patency versus occlusion of dentinal tubules, and thus in the aetiology and natural reparative process of dentine hypersensitivity.

Adult↗

PubMed2001

Effects of a liquid diet supplement containing structured medium- and long-chain triacylglycerols on bodyfat accumulation in healthy young subjects.

The effects of a liquid-formula diet supplement containing structured medium- and long-chain triacylglycerols (SMLCT) composed of medium- (10%) and long-chain (90%) fatty acids were compared with those of long-chain triacylglycerols (LCT) on bodyfat accumulation in 13 healthy male volunteers aged 18-20 years. The subjects were randomly assigned the SMLCT or LCT group. The subjects in each group received a liquid-formula diet supplement of the SMLCT or LCT, which provided 1040 kJ plus daily energy intake for 12 weeks. Mean energy intake containing liquid diet throughout the 12-week period did not differ between the SMLCT and LCT groups. Bodyweight of subjects in both groups increased slightly from the baseline throughout the 12-week period, but the differences were not significant. Rates of variation of bodyfat percentage were significantly lower in the SMLCT group than in the LCT group throughout the 12-week period. Comparisons between the SMLCT and LCT groups at baseline and 12 weeks showed no significant differences in any of the biochemical blood parameters. These results suggest that replacing LCT with SMLCT over long periods of time could produce bodyfat loss in the absence of reduced energy intake.

Adipose Tissue↗

PubMed2001

Dietary D-psicose, a C-3 epimer of D-fructose, suppresses the activity of hepatic lipogenic enzymes in rats.

D-Psicose (D-ribo-2-hexulose), a C-3 epimer of D-fructose, is present in small quantities in commercial carbohydrate complexes or agricultural products. Wistar male rats were fed experimental diets which consisted of 5% D-psicose, cellulose, D-fructose or D-glucose for 28 days. Abdominal adipose tissue weight was significantly lower (P < 0.05) in rats fed the D-psicose diet than in rats fed a D-fructose and D-glucose diets, even though the four dietary groups were offered the same amount throughout the experimental period. Fatty acid synthase and glucose 6-phosphate dehydrogenase activities in the liver were significantly lower (P < 0.05) in rats fed the D-psicose diet than in rats fed the D-fructose and D-glucose diets. However, lipoprotein lipase activities in the heart, soleus muscle and perirenal adipose tissue were the same. These results suggest that a supplement of D-psicose in the diet suppresses hepatic lipogenic enzyme activities. The lower abdominal fat accumulation in rats fed a D-psicose diet might result from lower lipogenesis in the liver.

Abdomen↗

PubMed2001

New approach for weight reduction by a combination of diet, light resistance exercise and the timing of ingesting a protein supplement.

We have reported that ingesting a meal immediately after exercise increased skeletal muscle accretion and less adipose tissue accumulation in rats employed in a 10 week resistance exercise program. We hypothesized that a possible increase in the resting metabolic rate (RMR) as a result of the larger skeletal muscle mass might be responsible for the less adipose deposition. Therefore, the effect of the timing of a protein supplement after resistance exercise on body composition and the RMR was investigated in 17 slightly overweight men. The subjects participated in a 12-week weight reduction program consisting of mild energy restriction (17% energy intake reduction) and a light resistance exercise using a pair of dumbbells (3-5 kg). The subjects were assigned to two groups. Group S ingested a protein supplement (10 g protein, 7 g carbohydrate, 3.3 g fat and one-third of recommended daily allowance (RDA) of vitamins and minerals) immediately after exercise. Group C did not ingest the supplement. Daily intake of both energy and protein was equal between the two groups and the protein intake met the RDA. After 12 weeks, the bodyweight, skinfold thickness, girth of waist and hip and percentage bodyfat significantly decreased in the both groups, however, no significant differences were observed between the groups. The fat-free mass significantly decreased in C, whereas its decrease in S was not significant. The RMR and post-meal total energy output significantly increased in S, while these variables did not change in C. In addition, the urinary nitrogen excretion tended to increase in C but not in S. These results suggest that the RMR increase observed in S might be associated with an increase in body protein synthesis.

Adult↗

PubMed2001

Risk of irregular menstrual cycles and low peak bone mass during early adulthood associated with age at menarche.

BACKGROUND: The risk of irregular menstrual cycles and low peak bone mass of the lumbar spine in young adult women, associated with age at menarche, has not been clearly defined. The aim of this study was to investigate this further. METHODS: A total of 180 college females aged 20-23 years were surveyed about menstruation, exercise, and calcium intake by means of a questionnaire. We also measured vertebral bone mineral density in these women by dual energy X-ray absorptiometry. The subjects were divided into six groups according to their age at menarche. Comparisons were made of the mean body mass index (BMI) and T-scores (the ratio to the mean bone mineral density of young adult Japanese women) among those groups, and odds ratios of irregular menstrual cycles and low peak bone mass less than 87% (- 1 standard deviation (SD) of T-scores were calculated using the mean menarcheal age (12 years) group as a control. RESULTS: The mean BMI and T-scores were significantly lower in delayed menarche groups (equal to or more than 13 years) compared with early menarche groups (equal to or less than 12 years). The odds ratios of irregular menstrual cycles were 5.9 (95% confidence intervals (CI) 1.7-20.6), 13.7 (95% CI 3.6-51.6), and 73 (95% CI 6.5-813.9) in the 13-, 14-, and more than 14 years menarcheal age groups, respectively. The odds ratio of low peak bone mass less than 87% (- 1SD) was 3.4 (95% CI 1.1-10.3) in the 14 years menarcheal age group. CONCLUSIONS: Young adult women with delayed menarche may be at high risk for irregular menstrual cycles and low peak bone mass.

Absorptiometry, Photon↗

PubMed2001

The thermic effect is greater for structured medium- and long-chain triacylglycerols versus long-chain triacylglycerols in healthy young women.

The purpose of this study was to investigate the hypothesis that a single dose of structured medium- and long-chain triacylglycerols (SMLCTs) composed of medium-chain (20%) and long-chain (80%) fatty acids would increase the metabolic rate more than a dose of long-chain triacylglycerols (LCTs) in 15 healthy young women aged 18 to 28 years. The effects on postingestive energy expenditure were compared for SMLCTs versus LCTs. On the experimental days, the subjects fasted overnight and then ingested 1,680 kJ SMLCTs or LCTs each day. Energy expenditure and the respiratory quotient (RQ) were measured before and after SMLCT and LCT ingestion by indirect calorimetry. Blood samples were collected before and after ingestion to obtain plasma and serum. Postingestive total energy expenditure (PTEE) was significantly higher after SMLCT ingestion versus LCT ingestion (26.9 +/- 1.0 v 25.5 +/- 1.1 kJ/kg/6 h, P < .05). The thermic effects of the test oil were also significantly greater after SMLCT ingestion compared with LCT ingestion (3.02 +/- 0.49 v 1.47 +/- 0.82 kJ/kg/6 h, P < .01). Plasma glucose and serum triacylglycerol concentrations were not significantly different. Serum free fatty acid and 3-hydroxybutyric acid concentrations were higher after SMLCT ingestion versus LCT ingestion. These results suggest that long-term substitution of SMLCTs for LCTs will produce body fat loss if energy intake remains constant.

3-Hydroxybutyric Acid↗