Biomedical subjects

Y Matsuda

Publications and source records attributed to Y Matsuda.

At least 109 records · Page 6Linked to original sources

PubMed2001

Geographical heterogeneity between Far Eastern and Western countries in prevalence of the virulence plasmid, the superantigen Yersinia pseudotuberculosis-derived mitogen, and the high-pathogenicity island among Yersinia pseudotuberculosis strains.

Yersinia pseudotuberculosis produces novel superantigenic toxins designated YPMa (Y. pseudotuberculosis-derived mitogen), YPMb, and YPMc and has a pathogenicity island termed HPI (high-pathogenicity island) and R-HPI (the right-hand part of the HPI with truncation in its left-hand part) on the chromosome. Analysis of the distribution of these virulence factors allowed for differentiation of species Y. pseudotuberculosis into six subgroups, thus reflecting the geographical spread of two main clones: the YPMa(+) HPI(-) Far Eastern systemic pathogenic type belonging to serotypes O1b, -2a, -2b, -2c, -3, -4a, -4b, -5a, -5b, -6, -10, and UT (untypeable) and the YPMs(-) HPI(+) European gastroenteric pathogenic type belonging to serotypes O1a and -1b. The YPMa(+) HPI(+) pathogenic type belonging to serotypes O1b, -3, -5a, -5b, and UT and the YPMb(+) HPI(-) nonpathogenic type belonging to non-melibiose-fermenting serotypes O1b, -5a, -5b, -6, -7, -9, -10, -11, and -12 were prevalent in the Far East. The YPMc(+) R-HPI(+) European low-pathogenicity type belonging to non-melibiose-fermenting serotype O3 and the YPMs(-) HPI(-) pathogenic type belonging to 15 serotypes were found to be prevalent all over the world. This new information is useful for a better understanding of the evolution and spread of Y. pseudotuberculosis.

Americas↗

PubMed2001

Global mapping analysis: stochastic approximation for multidimensional scaling.

In this paper, we propose global mapping analysis (GMA) as a new method to solve multidimensional scaling (MDS). By GMA, MDS is done by an online learning rule based on stochastic approximation. GMA need not directly calculate the disparity matrix for carrying out MDS, as Oja's PCA network do not calculate the correlation matrix. So, GMA is expected to be useful for multivariate data analysis on a large scale. Actually, it was verified by numerical experiments based on artificial data that GMA can work well even if the number of the attribute N is quite large (N=10,000.)

Data Interpretation, Statistical↗

PubMed2001

Comparative FISH mapping of Gab1 and Gab2 genes in human, mouse and rat.

Gab1 and Gab2 are members of the Gab family which act as adapters for transmitting various signals in response to stimuli through cytokine and growth factor receptors, and T- and B-cell antigen receptors. We determined chromosome locations of the two genes in human, mouse and rat by fluorescence in situ hybridization. The Gab1 gene was localized to chromosome 4q31.1 in human, 8C3 in mouse and 19q11.1--> q11.2 in rat, and the Gab2 gene was located on chromosome 11q13.4-->q13.5 in human, 7E2 in mouse and 1q33.2-->q33.3 in rat. All human, mouse and rat Gab1 and Gab2 genes were localized to chromosome regions where conserved homology has been identified among the three species.

Adaptor Proteins, Signal Transducing↗

PubMed2001

Chromosome assignment of four plexin A genes (Plxna1, Plxna2, Plxna3, Plxna4) in mouse, rat, Syrian hamster and Chinese hamster.

We determined chromosome locations of four plexin A subfamily genes, Plxna1, Plxna2, Plxna3 and Plxna4, in four rodent species, mouse, rat, Syrian hamster and Chinese hamster, by fluorescence in situ hybridization. Plxna1, Plxna2, Plxna3 and Plxna4 were localized to Chr 6E2, 1H6, XB-C1 and 6B1 in mouse, Chr 4q34.1, 13q26-->q27, Xq37.1-->q37.2 and 4q21.3-->q22 in rat, Chr 8qb1.1-->qb1.3, 11qb8, Xpb8 and 5qb3.3 in Syrian hamster, and Chr 8q1.2, 5q3.7, Xp2.7 and 1q2.2-->q2.3 in Chinese hamster, respectively. All the mouse and rat plexin A genes were localized to chromosome regions where conserved homology has been identified among human, mouse and rat.

Animals↗

PubMed2001

Cloning and chromosome mapping of human and chicken Iroquois (IRX) genes.

Three highly homologous homeobox genes (caupolican, araucan and mirror) have been identified in Drosophila. These genes belong to the novel Iroquois complex, which acts as a pre-pattern molecule in Drosophila neurogenesis. Recently several vertebrate Iroquois homologues (Irx) were isolated and found to be involved in pattern formation of various tissues. Here we report cytogenetic mapping of four human and five chicken Iroquois genes by FISH. Our findings revealed that vertebrate Irx genes are clustered at two different loci.

Amino Acid Sequence↗

PubMed2001

Expression and chromosome location of hamster Ku70 and Ku80.

Ku proteins play an important role in DNA double-strand break (DSB) repair, chromosome maintenance, and growth regulation. To understand the fundamental characteristics of Ku proteins, we examined the electrophoretic mobility and expression of hamster Ku70 and Ku80 and determined the chromosome locations of their genes. The electrophoretic mobility of hamster Ku proteins are different from that of human Ku proteins. No significant changes in the quantity of Ku proteins were observed in CHO-K1 cells treated with 10 Gy of ionizing radiation, suggesting that both proteins are expressed constitutively in amounts adequate to repair DNA DSBs. The chromosome locations of the Ku genes were determined by direct R-banding fluorescence in situ hybridization. The Ku70 gene was localized to Syrian hamster chromosome 4qa4.1--> qa4.2 and Chinese hamster chromosome 2p3.1, and the Ku80 gene was localized to Syrian hamster chromosome 4qb5--> qb6.1 and Chinese hamster chromosome 2p3.5-->p3.6. These results provide clues to the biological functions of Ku, as well as useful information for constructing comparative chromosome maps between hamsters and other mammalian species, including human, mouse, and rat.

Animals↗

PubMed2001

Sequence polymorphisms, allelic expression status and chromosome locations of the chicken IGF2 and MPR1 genes.

By screening 26 chicken breeds and lines, DNA polymorphisms were identified in the IGF2 and MPR1 genes, of which mammalian homologues are parentally imprinted, and the GAPD gene, a housekeeping control. Using the polymorphisms as genetic markers, we found that all three genes are expressed biallelically in embryonic tissues. IGF2 and MPR1 were mapped on chicken chromosomes 5 and 3, respectively, by fluorescence in situ hybridization, demonstrating conserved linkage homology between mammals and birds.

Alleles↗

PubMed2001

Comparative FISH mapping of human cDNA clones to chromosomes of the musk shrew (Suncus murinus, Insectivora).

Forty-one cDNA clones of human functional genes were newly mapped to chromosomes of the musk shrew (Suncus murinus, Insectivora) by fluorescence in situ hybridization, and a comparative cytogenetic map of 51 genes, including 10 genes reported in our previous study, was constructed between human (HSA) and musk shrew (SMU) chromosomes. In this comparative map, the 51 genes localized to human autosomes, except HSA 8, 16, and 20, were mapped to 15 shrew autosomes, except SMU 4, 16, 17 and 18. Twelve conserved segments were identified between human and shrew chromosomes, and six segments among the musk shrew, human, and mouse. Our results defined the presence of at least one inversion and several interchromosomal rearrangements that occurred during evolution after the two species diverged from a common ancestor. Localization of three major histocompatibility complex (MHC) genes to shrew chromosome 3 suggested that the MHC genes of the musk shrew are located in a cluster on chromosome 3. The cytogenetic map constructed in this study is the first cytogenetic map with many functional genes in insectivore species. This approach provides clues for clarifying the chromosomal evolution in this order.

Animals↗

PubMed2001

A comparative cytogenetic study of chromosome homology between chicken and Japanese quail.

In order to construct a chicken (Gallus gallus) cytogenetic map, we isolated 134 genomic DNA clones as new cytogenetic markers from a chicken cosmid DNA library, and mapped these clones to chicken chromosomes by fluorescence in situ hybridization. Forty-five and 89 out of 134 clones were localized to macrochromosomes and microchromosomes, respectively. The 45 clones, which localized to chicken macrochromosomes (Chromosomes 1-8 and the Z chromosome) were used for comparative mapping of Japanese quail (Coturnix japonica). The chromosome locations of the DNA clones and their gene orders in Japanese quail were quite similar to those of chicken, while Japanese quail differed from chicken in chromosomes 1, 2, 4 and 8. We specified the breakpoints of pericentric inversions in chromosomes 1 and 2 by adding mapping data of 13 functional genes using chicken cDNA clones. The presence of a pericentric inversion was also confirmed in chromosome 8. We speculate that more than two rearrangements are contained in the centromeric region of chromosome 4. All 30 clones that mapped to chicken microchromosomes also localized to Japanese quail microchromosomes, suggesting that chromosome homology is highly conserved between chicken and Japanese quail and that few chromosome rearrangements occurred in the evolution of the two species.

Animals↗

PubMed2001

Endogenous natriuretic peptides participate in renal and humoral actions of acute vasopeptidase inhibition in experimental mild heart failure.

Mild heart failure is characterized by increases in atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in the absence of activation of the renin-angiotensin-aldosterone system (RAAS). Vasopeptidase (VP) inhibitors are novel molecules that coinhibit neutral endopeptidase 24.11, which degrades the natriuretic peptides (NPs) and ACE. In a well-characterized canine model of mild heart failure produced by ventricular pacing at 180 bpm for 10 days, we defined the renal and humoral actions of acute VP inhibition with omapatrilat (OMA, n=6) and acute ACE inhibition (n=5) alone with fosinoprilat. We also sought to determine whether the NPs participate in the renal actions of acute VP inhibition by the administration of OMA together with an intrarenal administration of the NP receptor antagonist HS-142-1 (n=5). OMA resulted in a greater natriuretic response than did ACE inhibition in association with increases in plasma cGMP, ANP, BNP, urinary cGMP, urinary ANP excretion, and glomerular filtration rate (P<0.05 for OMA versus ACE inhibition). Plasma renin activity was increased only in the group subjected to ACE inhibition. Administration of intrarenal HS-142-1 attenuated the renal properties of OMA in association with a decrease in urinary cGMP excretion despite similar increases in plasma ANP and BNP. This study provides new insight into a unique new pharmacological agent that has beneficial renal actions in experimental mild heart failure beyond the actions that are observed with ACE inhibition alone and that are linked to the NP system.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed2001

Comparative evaluation of tableting compression behaviors by methods of internal and external lubricant addition: inhibition of enzymatic activity of trypsin preparation by using external lubricant addition during the tableting compression process.

This study evaluated tableting compression by using internal and external lubricant addition. The effect of lubricant addition on the enzymatic activity of trypsin, which was used as a model drug during the tableting compression process, was also investigated. The powder mixture (2% crystalline trypsin, 58% crystalline lactose, and 40% microcrystalline cellulose) was kneaded with 5% hydroxypropyl cellulose aqueous solution and then granulated using an extruding granulator equipped with a 0.5-mm mesh screen at 20 rpm. After drying, the sample granules were passed through a 10-mesh screen (1680 microm). A 200-mg sample was compressed by using 8-mm punches and dies at 49, 98, 196, or 388 MPa (Mega Pascal) at a speed of 25 mm/min. The external lubricant compression was performed using granules without lubricant in the punches and dies. The granules were already dry coated by the lubricant. In contrast, the internal lubricant compression was performed using sample granules (without dry coating) containing 0.5% lubricant. At 98 MPa, for example, the compression level using the external lubricant addition method was about 13% higher than that for internal addition. The significantly higher compressing energy was also observed at other MPas. By comparison, the friction energy for the external addition method calculated based on upper and lower compression forces was only slightly larger. The hardness of tablets prepared using the internal addition method was 34% to 48% lower than that for the external addition method. The total pore volume of the tablet prepared using the external addition method was significantly higher. The maximum ejection pressure using the no-addition method (ie, the tablet was prepared using neither dry-coated granules nor added lubricant) was significantly higher than that of other addition methods. The order was as follows: no addition, external addition, and then internal addition. The ejection energy (EE) for internal addition was the lowest; for no addition, EE was the highest. In the dissolution test, the tablets obtained using external addition immediately disintegrated and showed faster drug release than those prepared using internal addition. This result occurred because the water penetration rate of the tablet using the external addition was much higher. The trypsin activity in tablets prepared using the external addition method was significantly higher than that produced using the internal addition method at the same pressure. All these results suggest that the external addition method might produce a fast-dissolution tablet. Because the drug will be compressed using low pressure only, an unstable bulk drug may be tableted without losing potency.

Algorithms↗

PubMed2001

Effects of dermatan and dextran sulfates on arginine amidase activity released from isolated rabbit arteries.

We examined the levels of arginine amidase secreted from isolated rabbit arteries treated with dermatan and dextran sulfates, and the relation between the secretion of arginine amidase activity and the concentration of dermatan sulfate added to these arteries. The results showed that while dextran sulfate tended to accelerate the release of arginine amidase activity from the isolated rabbit ear artery, the induction was not significant. There was a significant increase in the level of arginine amidase released from the lower portion of isolated rabbit aorta (p<0.05), but no significant change in the upper portion of the aorta. In contrast, the addition of dermatan sulfate significantly increased the level of arginine amidase activity released from the isolated rabbit ear artery and the upper and lower portions of the aorta (p<0.05). Linear dose-response relationships were observed between the level of arginine amidase activity released from the isolated rabbit ear artery and aorta and the concentration of dermatan sulfate added.

Animals↗

PubMed2001

Photochemical and oxidative degradation of the solid-state tretinoin tocoferil.

The photostability of tretinoin tocoferil was investigated under irradiation with three kinds of lamps, i.e., a cool white fluorescent lamp, a UV-A fluorescent lamp and a D65 fluorescent lamp. A combination of the cool white fluorescent lamp and the UV-A fluorescent lamp, and the D65 lamp having relative spectral power distribution similar to that of direct daylight, correspond to options 2 and 1 in ICH Guidelines, respectively. The photodegradation apparently followed second-order kinetics under these light sources and the degradation rate constant under exposure by the D65 lamp was larger than that by the cool white fluorescent lamp. The drug was susceptible to degradation by visible and UV light below 480 nm and was degraded most remarkably at around 420 nm, showing a wavelength-dependency. The semi-logarithmic plots of apparent degradation rate constant against the reciprocal of illuminance showed a good linear relationship in the Arrhenius-type fashion, and the photostability under ordinary illumination conditions could be predicted from the data obtained under the accelerated illumination conditions. The rate of oxidative degradation was slightly accelerated with the rise of temperature. Thermodynamic parameter was calculated from the Arrhenius plot. The degradation rate constant rapidly increased in proportion to partial pressure of oxygen below 20 kPa.

Chemical Phenomena↗

PubMed2001

[The chemistry of cyclazines].

This review summarizes our studies on the development of the syntheses of cyclazine derivatives. These studies involve the following four main subjects; 1) the studies on cycl[3.2.2]azine derivatives; 2) the studies on cycl[3.3.2]azinone derivatives; 3) the studies on azacycl[3.3.3]azine derivatives; 4) the studies on cyclazinophane derivatives.

Heterocyclic Compounds, 3-Ring↗

PubMed2001

Cloning and characterization of the cpyA gene encoding intracellular carboxypeptidase from Aspergillus nidulans.

Carboxypeptidase Y (CPY) has been used as a maker enzyme for investigations on intracellular transport of vacuolar proteins and on vacuolar biogenesis in Saccharomyces cerevisiae. We describe the cloning and characterization of the CPY homologue encoding gene (cpyA) from the filamentous fungus Aspergillus nidulans. The cpyA gene has one intron and encodes a protein with 552 amino acids containing a putative signal sequence and pro-sequence. The predicted CpyA protein is highly similar in sequence with carboxypeptidases from several yeast species and contains a catalytic triad (Asp-His-Ser) like that of serine carboxypeptidase. The cpyA disruptant cells showed reduced levels of intracellular carboxypeptidase. These results suggest that the cpyA gene encodes a vacuolar carboxypeptidase in A. nidulans.

Amino Acid Sequence↗

PubMed2001

Behaviors of mice given forced-swimming.

Behaviors of mice in the forced swimming test are motionlessness, climbing and the other stereotypical behaviors. We observed these behaviors in different ages and sex and in repeated forced swimming trials. The findings were 1) quantities of the climbing and the other behaviors were different with the age and sex, 2) repeated per day forced swimming remarkably increased motionlessness and motionlessness is memorized for at least 14 days, and 3) climbing is the typical opposite behavior of motionlessness and was related to adrenergic but not serotonergic neuronal activity. When these behaviors are recognized as adaptation behaviors, we conclude that mice given repeated forced swimming, but not mice given one trial of forced swimming, can be considered as a model of human depression relating to adrenaline neuronal activity.

Age Factors↗

PubMed2001

RP-1776, a novel cyclic peptide produced by Streptomyces sp., inhibits the binding of PDGF to the extracellular domain of its receptor.

RP-1776, a novel cyclic peptide, was isolated from the culture broth of Streptomyces sp. KY11784. RP-1776 selectively inhibited the binding of PDGF BB to the extracellular domain of the PDGF beta-receptor with an IC50 value of 11 +/- 6 microM. Detailed binding experiments suggested that RP-1776 directly interacts with PDGF BB. RP-1776 inhibited the phosphorylation of the PDGF beta-receptor induced by PDGF BB. These results suggested that RP-1776 antagonizes the signaling of PDGF BB probably through the inhibition of PDGF BB binding to the PDGF beta-receptor.

Animals↗

PubMed2001

Circulating transforming growth factor beta 1 as a predictor of liver metastasis after resection in colorectal cancer.

Plasma transforming growth factor beta1 (TGF-beta1) has been reported to be correlated with the extent of disease in colorectal cancer, but it is not known whether measuring this cytokine can help predict liver metastasis after curative resection. We prospectively studied whether plasma TGF-beta1 levels could predict liver metastasis in 117 patients with colorectal cancer before and after curative resection. Blood samples were drawn before and 2 weeks after surgery to determine the cytokine levels. Abdominal ultrasonography or computed tomography was done every 3 months after surgery. The primary end point for follow-up was recurrence. Seventy-seven of 117 cases (66%) had preoperative levels of the cytokine higher than the borderline limit of 7.5 ng/ml. Postoperative levels were >7.5 ng/ml in 29 of 117 patients (25%). The median follow-up period was 42 months (range, 5--66 months), with follow-up of all 117 patients. No recurrence was observed in 13 patients with Dukes' stage A lesions. Liver metastasis occurred in 18 of 104 patients (17%) with Dukes' stage B or C disease. Fourteen of 18 patients (78%) who developed liver metastasis had shown a postoperative plasma TGF-beta1 level of >7.5 ng/ml. Cox proportional hazards regression analysis showed that the postoperative level was a significant predictive factor for liver metastasis (P < 0.001). A single point measurement of plasma TGF-beta1 levels at 2 weeks after curative resection seems to be able to predict liver metastasis in colorectal cancer. This finding suggests the value of a prospective trial of liver-targeted adjuvant therapy for patients with elevated postoperative plasma TGF-beta1 levels.

Aged↗