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S Sato

Publications and source records attributed to S Sato.

At least 379 records · Page 21Linked to original sources
PubMed2000

Generation of 7137 non-redundant expressed sequence tags from a legume, Lotus japonicus.

For comprehensive analysis of genes expressed in a model legume, Lotus japonicus, a total of 22,983 5' end expressed sequence tags (ESTs) were accumulated from normalized and size-selected cDNA libraries constructed from young (2 weeks old) plants. The EST sequences were clustered into 7137 non-redundant groups. Similarity search against public non-redundant protein database indicated that 3302 groups showed similarity to genes of known function, 1143 groups to hypothetical genes, and 2692 were novel sequences. Homologues of 5 nodule-specific genes which have been reported in other legume species were contained in the collected ESTs, suggesting that the EST source generated in this study will become a useful tool for identification of genes related to legume-specific biological processes. The sequence data of individual ESTs are available at the web site: http://www.kazusa.or.jp/en/plant/lotus/EST/.

Codon↗
PubMed2000

Structural analysis of Arabidopsis thaliana chromosome 3. I. Sequence features of the regions of 4,504,864 bp covered by sixty P1 and TAC clones.

Based on the physical map of Arabidopsis thaliana chromosome 3 previously constructed with CIC YAC, TAC, P1 and BAC clones (Sato, S. et al., DNA Res., 5, 163-168, 1998), a total of 60 P1 and TAC clones were sequenced, and the sequence features of the resulting 4,504,864 bp regions were analyzed by applying various computer programs for similarity search and gene modeling. As a result, a total of 1054 potential protein-coding genes were identified. The average density of the genes identified was 1 gene per 4066 bp. Introns were observed in 77% of the genes, and the average number per gene and the average length of the introns were 3.9 and 156 bp, respectively. These sequence features are essentially identical to those of chromosome 5 in our previous reports, but the gene density was slightly higher than that observed for chromosomes 2 and 4. The regions also contained 10 tRNA genes when searched by similarity to reported tRNA genes and the tRNA scan-SE program. The sequence data and information on the potential genes are available through the World Wide Web database KAOS (Kazusa Arabidopsis data Opening Site) at http://www.kazusa.or.jp/kaos/.

Arabidopsis↗
PubMed2000

pH jump studies of the folding of the multidomain ribosomal protein L9: the structural organization of the N-terminal domain does not affect the anomalously slow folding of the C-terminal domain.

The folding kinetics of the multidomain ribosomal protein L9 were studied using pH jump stopped-flow fluorescence and circular dichroism (CD) in conjunction with guanidine hydrochloride (GdnHCl) jump stopped-flow CD experiments. Equilibrium CD and 1D (1)H NMR measurements demonstrated that the C-terminal domain unfolds below pH 4 while the N-terminal domain remains fully folded. Thus, the N-terminal domain remains folded during the pH jump experiments. The folding rate constant of the C-terminal domain was determined to be 3.5 s(-1) by pH jump experiments conducted in the absence of denaturant using stopped-flow CD and fluorescence. CD-detected GdnHCl jump measurements showed that the N- and C-terminal domains fold independently each by an apparent two-state mechanism. The folding rate constant for the N-terminal domain and the C-terminal domain in the absence of denaturant were calculated to be 760 and 4. 7 s(-1), respectively. The good agreement between the pH jump and the denaturant concentration jump experiments shows that the folding rate of the C-terminal domain is the same whether or not the N-terminal domain is folded. This result suggests that the slow folding of the C-terminal domain is not a consequence of unfavorable interactions with the rest of the protein chain during refolding. This is an interesting result since contact order analysis predicts that the folding rate of the C-terminal domain should be noticeably faster. The folding rate of the isolated N-terminal domain was also measured by stopped-flow CD and was found to be the same as the rate for the domain in the intact protein.

Acids↗
PubMed2000

Periodic limb movements in sleep: state-dependent excitability of the spinal flexor reflex.

OBJECTIVE: To test the hypothesis that periodic limb movements (PLMs) are related to spinal flexor reflexes (FRs), the authors compared the state-dependent changes in FR excitability in 10 patients with restless legs syndrome (RLS) and PLMs with those from matched controls. BACKGROUND: PLM is a disorder of motor control during sleep, frequently occurring in RLS. Clinically, PLMs resemble spinal FRs. METHODS: FRs were obtained by electrically stimulating the medial plantar nerve and recording from antagonist leg and thigh muscles bilaterally. RESULTS: Compared with controls, patients had significantly increased spinal cord excitability, as indicated by lower threshold and greater spatial spread of the FR, which was more prominent during sleep. Multiple late responses were seen during sleep in all patients and in some controls at higher threshold. The most prominent of these responses had a very long duration and a latency range of 250 to 800 msec, and because of its close temporal relationship to the FR stimulus, the authors considered it was a late, high-threshold component of the FR (FR3). The authors also found a similarity between the pattern of muscle recruitment and spatial spread of late components of the FR and those of spontaneous PLMs. CONCLUSIONS: The results support the hypothesis that PLMs in RLS and FRs share common spinal mechanisms and suggest that PLMs may result from enhanced spinal cord excitability in RLS patients. Because dopaminergic mechanisms are involved in spinal FR control, the results are consistent with the current view that RLS is a disorder of dopaminergic function.

Adult↗
PubMed2000

Reduced expression of p27(Kip1) correlates with an early stage of cancer invasion in oral squamous cell carcinoma.

Down-regulation of p27(Kip1) has been reported to correlate with poor survival of various carcinoma patients including oral squamous cell carcinomas (OSCCs). It is still unclear, however, at what stage of oral carcinogenesis the down-regulation of this protein occurs. In this study, therefore, we evaluated immunoexpression of p27(Kip1) protein in 17 cases of oral epithelial dysplasia and succeeding invasive OSCC in the same patient. We reported here that 88% cases showed high p27(Kip1) expression in dysplastic lesions, whereas 82% cases of succeeding invasive OSCC exhibited reduced expression. The reduction of p27(Kip1) expression was also observed in 16 of 19 (84%) early invasive lesions and well correlated with Ki-67 expression which is good indicator of cell proliferation. We also investigated immunoexpression of p53 protein of which abnormality has been known to occur during the early stage of OSCC development. Overexpression of p53 protein was demonstrated in 29% of dysplastic lesions, 42% of early invasive and 71% of invasive OSCCs. These findings suggest that abnormalities of both p53 and p27(Kip1) are involved in the carcinogenesis of OSCC, but they seem to play their role at different stages of oral cancer development, respectively. Reduced expression of p27(Kip1) may concern the cancer invasion directly or indirectly as well as abnormal proliferation.

Carcinoma, Squamous Cell↗
PubMed2000

Impact of a plastid-bearing endocytobiont on apicomplexan genomes.

Both the chromosomal and extrachromosomal components of the apicomplexan genome have been supplemented by genes from a plastid-bearing endocytobiont: probably an algal cell. The sequence of the apicomplexan plastid's vestigial genome indicates that a large number (>100) of genes of endocytobiotic origin must have transferred laterally to the host cell nucleus where they control maintenance of the plastid organelle and supply its functional components by means of post-translational protein trafficking. Should the nuclear genes prove to be less divergent phylogenetically than those left on the plastid genome, they might give better clues than we have at present to the origin of the plastid-bearing endocytobiont. Most of these nuclear genes still await discovery, but the on-going genome sequencing project will reveal the function of the organelle, as well as many "housekeeping" processes of interest on a wider front. The plastid's own protein synthetic machinery, being cyanobacterial in origin, offers conventional targets for antibiotic intervention, and this is discussed here using a structural model of elongation factor Tu. Uncovering the vital function(s) of the plastid organelle will provide new drug targets.

Amino Acid Sequence↗
PubMed2000

The number of farm mates influences social and maintenance behaviours of Japanese Black cows in a communal pasture.

The objective of the present study was to investigate optimal group size in cattle in communal pastures where cattle from various farms are turned out: (1) to ascertain if cows derived from each farm form an affiliative group and (2) to investigate the effect of the number of farm mates on social and maintenance behaviours when farm mates form an affiliative group. Farm mates were defined as cows from the same farm. A total of 27 cows having zero, one, two to four, or sixteen farm mates were selected as focal animals in two communal pastures. Each focal animal was followed by an individual observer for 8 h from sunrise. The nearest neighbour and the distance to the nearest neighbour were recorded at 10-min intervals, and maintenance behaviours at 1-min intervals; social behaviours and participants were recorded continuously. Most focal animals frequently choose cows from the same farm as their nearest neighbours allogroomed with these farm mates significantly more (P<0.001). Two focal animals did not form affiliative groups with farm mates. The mean distance to the nearest neighbours, whether farm mates or non-farm mates from focal animals having one and two to four farm mates was shorter than cows turned out with no farm mate (1.4 vs. 1.9 times as long as a cow's body length, P<0.05). Cows having two to four farm mates performed (7.8 s/h/cow, P=0.06) and received allogrooming more (9.8 s/h/cow) and escaped less during agonistic encounters (0.1 frequencies/h/cow, P<0.01) than ones having other numbers of farm mates. The mean duration of grazing behaviour per bout tended to increase with the number of farm mates (5.2 to 10.3 min, P<0.05). The mean duration of recumbency behaviour of cows having two to four farm mates (44.0 min/bout) was longer than the ones having other numbers of farm mates. Social and maintenance behaviours of cows having 16 farm mates were like those having zero or one farm mates, which suggested that the social bond among them was weak. It is concluded that a group of cows having two to four farm mates, that is, a group size of three to five cows, may be optimal for a stable life in a communal pasture.

Journal Article↗
PubMed2000

Unique clinical characteristics of patients with hepatocellular carcinoma who present with high plasma des-gamma-carboxy prothrombin and low serum alpha-fetoprotein.

BACKGROUND: Although the importance of alpha-fetoprotein (AFP) and des-gamma-carboxy prothrombin (DCP) in the clinical treatment of hepatocellular carcinoma (HCC) has been studied extensively, the authors examined the clinical picture of HCC with regard to the state of these two tumor markers. METHODS: The authors categorized 237 HCC cases into 4 groups according to levels of AFP and DCP: high levels of AFP with low DCP levels, high DCP levels with low AFP levels, high levels of both tumor markers, and low levels of both tumor markers. Comparisons of survival rates were made among these groups using the Kaplan-Meier product limit method, and for other comparisons of clinical parameters the Fisher PSLD test was used. Prognostic significance was tested with the Cox proportional hazards model. RESULTS: The cutoff values were set at 100 ng/mL for AFP and 0.0625 AU/mL for DCP. Forty-eight patients (20.7%) had high levels of AFP and low levels of DCP, 22 (9.3%) had high DCP levels and low levels of AFP, 12 (4.6%) had high levels of both AFP and DCP, and 155 (65.4%) had low levels of both DCP and AFP. Patients with high levels of DCP but low levels of AFP were predominantly male and had large lesions but few nodules. Patients with high levels of both tumor markers had the most discouraging outcome observed in this study (death within 3 years). CONCLUSIONS: Patients with high levels of DCP and low levels of AFP exhibited the unique clinical characteristic of large HCC nodules that were few in number. In addition, it was observed that measurement of both AFP and DCP can predict the survival of patients.

Adult↗
PubMed2000

Cutting edge: endotoxin tolerance in mouse peritoneal macrophages correlates with down-regulation of surface toll-like receptor 4 expression.

Monocytes/macrophages exposed to LPS show reduced responses to second stimulation with LPS, which is termed LPS tolerance. In this study, we investigated molecular mechanism of LPS tolerance in macrophages. Mouse peritoneal macrophages pre-exposed to LPS exhibited reduced production of inflammatory cytokines in a time- and dose-dependent manner. Activation of neither IL-1 receptor-associated kinase nor NF-kappaB was observed in macrophages that became tolerant by LPS pretreatment, indicating that the proximal event in Toll-like receptor 4 (TLR4)-MyD88-dependent signaling is affected in tolerant macrophages. Although TLR4 mRNA expression significantly decreased within a few hours of LPS pretreatment and returned to the original level at 24 h, the surface TLR4 expression began to decrease within 1 h, with a gradual decrease after that, and remained suppressed over 24 h. A decrease in inflammatory cytokine production in tolerant macrophages well correlates with down-regulation of the surface TLR4 expression, which may explain one of the mechanisms for LPS tolerance.

Animals↗
PubMed2000

Relationship between alcohol drinking, ADH2 and ALDH2 genotypes, and risk for hepatocellular carcinoma in Japanese.

The polymorphism in the ALDH2 gene plays a central role in Asian alcohol hypersensitivity and has been associated with the risk for esophageal cancer. In the present study, we attempted to examine associations between the ADH2 and ALDH2 polymorphisms, alcohol drinking and hepatocellular carcinoma (HCC) development in a case-control study in Japan. One hundred and two patients with HCC (85 males and 17 females) and 125 control subjects (101 males and 24 females) were enrolled in the study. Higher cumulative amounts of alcohol consumption (drink-years of > or = 40 drinks/day x year) showed a significant association with HCC development (odds ratio, OR = 2.7; 95% CI = 1.3-5.5, adjusted for age and smoking). By contrast, we could find no association of the ALDH2 genotypes with HCC development (adjusted OR for ALDH2*1/*2 = 1.1; 95% CI = 0.6-2.1). Likewise, the ADH2 genotypes were not associated with HCC development (adjusted OR for ADH2*2/*2 = 0.8; 95% CI = 0.5-1.5). The present results do not support a contribution of acetaldehyde, an active metabolite of ethanol, to HCC development and rather indicate a direct involvement of ethanol in hepatocarcinogenesis.

Aged↗
PubMed2000

Structural analysis of Arabidopsis thaliana chromosome 5. X. Sequence features of the regions of 3,076,755 bp covered by sixty P1 and TAC clones.

In our ongoing project to deduce the nucleotide sequence of Arabidopsis thaliana chromosome 5, non-redundant P1 and TAC clones have been sequenced on the basis of the fine physical map, and as of January, 2000, the sequences of 16.6 Mb representing approximately 60% of chromosome 5 have been accumulated and released at our web site. Along with the sequence determination, structural features of the sequenced regions have been analyzed by applying a variety of computer programs, and we already predicted a total of 2697 potential protein coding genes in the 11,166,130 bp regions, which are covered by 159 P1 and TAC clones. In this paper, we describe the structural features of the 3,076,755 bp regions covered by newly analyzed 60 P1 and TAC clones. A total of 715 potential protein coding genes were identified, giving an average density of the genes identified of 1 gene per 4001 bp. Introns were observed in 80% of the genes, and the average number per gene and the average length of the introns were 4.5 and 147 bp, respectively. These sequence features are nearly identical to those in our latest report in which the data were compiled based on a new standard of gene assignment including the computer-predicted hypothetical genes. The regions also contained 12 tRNA genes when searched by similarity to reported tRNA genes and the tRNA scan-SE program. The sequence data and information on the potential genes are available through the World Wide Web database KAOS (Kazusa Arabidopsis data Opening Site) at http://www.kazusa.or.jp/kaos/.

Arabidopsis↗
PubMed2000

3,4-dihydro-2(1H)-quinolinone as a novel antidepressant drug: synthesis and pharmacology of 1-[3-[4-(3-chlorophenyl)-1-piperazinyl]propyl]-3,4- dihydro-5-methoxy-2(1H)-quinolinone and its derivatives.

To develop a novel antidepressant drug with central nervous system-stimulating activity, we prepared a series of 1-[omega-(4-substituted phenyl-1-piperazinyl)alkyl]-3, 4-dihydro-2(1H)-quinolinone derivatives and examined their activities by their effects at 30 and 100 mg/kg po on the sleeping time of mice anesthetized with halothane and on the time required for recovery from coma induced in mice by cerebral concussion. We examined their binding affinities for sigma receptors by evaluating their ability to inhibit [(3)H]-1,3-di(o-tolyl)guanidine ([(3)H]DTG) binding to the rat whole brain membrane in comparison with three putative sigma receptor agonists: 1,3-di(o-tolyl)guanidine (DTG, 66), (+)-1,2,3,4,5,6-hexahydro-6,11-dimethyl-3-(2-propenyl)-2, 6-methano-3-benzazecin-8-ol (SKF10,047, 67), and (+)-1,2,3,4,5, 6-hexahydro-6,11-dimethyl-3-(3-methyl-2-butenyl)-2, 6-methano-3-benzazecin-8-ol (pentazocine, 68). Among the series of derivatives, 1-[3-[4-(3-chlorophenyl)-1-piperazinyl]propyl]-3, 4-dihydro-5-methoxy-2(1H)-quinolinone hydrochloride (34b) and its mesylate (34c), at a dose of 30 mg/kg po, reduced the sleeping time and the time for recovery from coma and they inhibited [(3)H]DTG binding for sigma receptors. The putative sigma receptor agonists reduced the sleeping time and the time for recovery from coma whereas two sigma receptor antagonists, alpha-(4-fluorophenyl)-4-(5-fluoro-2-pyrimidinyl)-1-piperazinebutanol hydrochloride (BMY14802, 69) and cis-9-[3-(3, 5-dimethyl-1-piperazinyl)propyl]carbazole dihydrochloride (rimcazole, 70), were inactive in the two tests. Preadministration of the putative sigma receptor antagonists 69 (3 mg/kg po) and 70 (30 mg/kg po) completely antagonized the actions of 34b and the sigma receptor agonists in the test for recovery from coma. These results suggested that 34b and 34c are sigma receptor agonists. Furthermore, a single administration of 1 and 10 mg/kg po 34b and 34c showed antidepressant-like activity by reducing the immobility time in the forced-swimming test with mice, while a tricyclic antidepressant, 10, 11-dihydro-N,N-dimethyl-5H-dibenz[b,f]azepine-5-propanamine hydrochloride (imipramine, 1) (10 and 30 mg/kg po), did not reduce the time after a single administration. 1 reduced the time after repeated administration of 30 mg/kg po once a day for 4 days. The structure-activity relationship of the series of compounds is also discussed.

Animals↗
PubMed2000

Postoperative changes in cerebral metabolism in temporal lobe epilepsy.

BACKGROUND: Fludeoxyglucose F 18 positron emission tomography ((18)F-FDG-PET) can detect focal metabolic abnormalities ipsilateral to the seizure focus in 80% of patients with temporal lobe epilepsy (TLE). Regions outside the epileptogenic zone can also be affected. We hypothesized that these remote regions might show altered metabolism, tending to return toward normal values, after surgery. DESIGN: Interictal preoperative and postoperative (18)F-FDG-PET metabolism were compared in patients with refractory TLE. Based on pathological findings, disease was classified in the following 3 groups: mesial temporal sclerosis, mass lesions, and no pathological diagnosis. Quantitative PET data analysis was performed using the region-of-interest template previously described. Global normalization was used to adjust for the effect of antiepileptic medication changes. Data were analyzed by Wilcoxon signed rank test and analysis of variance. SETTING: The Clinical Epilepsy Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health. PATIENTS: Twenty-two patients with refractory TLE. RESULTS: Preoperatively, in all groups, cerebral metabolic rate for glucose was decreased ipsilateral to the resection site in inferior lateral temporal, inferior mesial temporal, and inferior frontal areas and thalamus. Postoperatively, in all groups, cerebral metabolic rate for glucose increased in ipsilateral inferior frontal area and thalamus. In the mesial temporal sclerosis group, we found a statistically significant increase in the contralateral thalamus. CONCLUSION: Temporal lobe epilepsy is associated with extensive preoperative decreased metabolism in inferior lateral temporal, inferior mesial temporal, and inferior frontal areas and thalamus. Postoperatively, we found increased IF and thalamic metabolism. Seizures may have a reversible effect on brain areas connected with, but remote from, the epileptogenic cortex. Arch Neurol. 2000;57:1447-1452

Adult↗
PubMed2000

Synthesis of Dicationic Telluranes by Remote Oxidation through a pi-Conjugated System This work was supported by the Ministry of Education, Science, Sports and Culture, Japan (Grant-in-Aid for Scientific Research on Priority Areas: Grant No. 09239104, Grant-in Aid for Scientific Research (B): Grant No. 11440186, and Grant-in-Aid for Encouragement of Young Scientists: Grant No. 10740286), and the Fund of Tsukuba Advanced Research Alliance (TARA) project (University of Tsukuba).

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Journal Article↗
PubMed2000

Six family genes--structure and function as transcription factors and their roles in development.

The members of the Six gene family were identified as homologues of Drosophila sine oculis which is essential for compound-eye formation. The Six proteins are characterized by the Six domain and the Six-type homeodomain, both of which are essential for specific DNA binding and for cooperative interactions with Eya proteins. Mammals possess six Six genes which can be subdivided into three subclasses, and mutations of Six genes have been identified in human genetic disorders. Characterization of Six genes from various animal phyla revealed the antiquity of this gene family and roles of its members in several different developmental contexts. Some members retain conserved roles as components of the Pax-Six-Eya-Dach regulatory network, which may have been established in the common ancestor of all bilaterians as a toolbox controlling cell proliferation and cell movement during embryogenesis. Gene duplications and cis-regulatory changes may have provided a basis for diverse functions of Six genes in different animal lineages.

Amino Acid Sequence↗
PubMed2000

Effects of the administration of wheat bran biscuit: changes in the diet.

We developed hard biscuit containing 30% wheat bran (WB biscuit) and administered it to 12 volunteers at 7.5 g/day (7.5 g group) or 15 g/day (15 g group) as wheat bran for 12 weeks. After 12 weeks, the dietary fiber intake from foods other than wheat bran decreased slightly in the both groups, in the 15 g group was the decrease notable especially, after the beginning of WB biscuit administration. We suggest that a closest attention to changes in dietary habit associated with intervention is needed in intervention studies using patients leading a normal life.

Diet Records↗
PubMed2000

Choroidal metastasis presented as the initial symptom of the recurrence from ovarian endometrioid adenocarcinoma: A case report.

Choroidal metastasis from recurrent ovarian cancer is extremely rare. To our knowledge, this report is the first such case of endometrioid adenocarcinoma. A 30-year-old pregnant woman presented to an ophthalmologist in January 1999 because of a rapid visual deterioration. Ophthalmologic evaluation revealed a metastatic choroidal tumor from ovarian cancer which had been diagnosed 10 years ago. After cesarean section, multiple metastases were found including the choroid, scalp, bone, and lung, and she received four courses of single agent carboplatin chemotherapy. She died of disease in July 1999. This case highlights the need to investigate the etiology of visual complaints in patients with a history of ovarian cancer even in the early stage.

Adult↗