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Biomedical subjects

Y Matsuda

Publications and source records attributed to Y Matsuda.

At least 307 records · Page 17Linked to original sources
PubMed1998

Identification and characterization of STK12/Aik2: a human gene related to aurora of Drosophila and yeast IPL1.

Mutations in aurora of Drosophila and related Saccharomyces cerevisiae IPL1 protein kinases are known to cause abnormal chromosome segregation. We earlier isolated a cDNA encoding a novel human protein kinase Aik which shares high amino acid identity with the Aurora/Ipl1 protein kinase family. In the present study, a second human cDNA highly homologous to aurora/IPL1 (Aik2) was identified and the nucleotide sequence was determined (gene symbol STK12). The C-terminal kinase domain of the STK12 encoded protein shares high amino acid sequence identity with those of mouse STK-1 (90%), rat AIM-1 (90%), human Aik (69%), mouse IAK1/Ayk1 (69%), Xenopus pEg2 (68%), Drosophila Aurora (62%), and yeast Ipl1 (45%), whereas the N-terminal domain of the STK12 protein shares little homology with those of Aurora/Ipl1 family members except for AIM-1 and STK-1. Northern blotting analyses revealed that STK12 expression was high in thymus, while low level expression was detected in small intestine, testis, colon, spleen, and brain. The STK12 protein content in HeLa cells is low in S phase, but it accumulates during M phase. STK12 was mapped to human chromosome 17p13.1 by fluorescence in situ hybridization. The chromosome location of STK12 was further defined using a radiation hybrid panel (Stanford G3), that showed a linkage with marker WI-7901 (LOD Score 7.83) located between D17S938 and D17S786.

Animals↗
PubMed1998

Potentiation of natriuretic peptide action by the beta-adrenergic blocker carvedilol in hypertensive rats: a new antihypertensive mechanism.

Treatment with a beta-adrenergic blocker (beta-blocker) in hypertension is associated with increased plasma atrial natriuretic peptide (ANP) levels despite a decrease in cardiac overload. The mechanism and pathophysiological significance of the phenomenon remain unclear. To clarify the role of the ANP system in the antihypertensive effects of the beta-blocker, we investigated the effects of carvedilol (30 mg/kg x day, orally, for 4 weeks) on the ANP system in stroke-prone spontaneously hypertensive rats (SHR-SP/Izm). Plasma ANP levels showed a significant increase despite a significant decrease in blood pressure and heart rate in the carvedilol group. Although ANP messenger RNA levels in the heart did not change, messenger RNA levels of the natriuretic peptide-C (NP-C) receptor as a clearance receptor showed a significant decrease in both the aorta and lung in the carvedilol group. NP-C receptor densities were also significantly decreased in the lung in this group. The biological half-life of exogenous ANP in circulating blood was prolonged in the carvedilol group compared with that in the control group. Administration of the ANP receptor antagonist, HS-142-1, resulted in a greater increase in systolic blood pressure in the carvedilol group than in the control group. In addition, both basal and ANP-stimulated cGMP contents in the aorta were significantly higher in the carvedilol group. These results suggest that carvedilol potentiates the hypotensive action of ANP by increasing plasma ANP levels and enhancing the vascular response to ANP. These effects were closely related to the down-regulation of the NP-C receptor. The newly found mechanism seems to account for a sizable portion of the antihypertensive effects of carvedilol and could be of potential importance in the treatment of cardiovascular disease with beta-blockers.

Adrenergic beta-Antagonists↗
PubMed1998

Morphodifferentiation of skeletal muscle fiber ends at the myotendinous junction in the postnatal Chinese hamster: a scanning electron microscopic study.

The postnatal morphodifferentiation of muscle fiber ends at the myotendinous junction was examined by scanning electron microscopy in gastrocnemius muscles of the Chinese hamster. Muscle fiber ends during the first week were simply conical or slightly complex, having a few pit-like invaginations and longitudinal and narrow clefts. By the second week, fiber ends gradually became complicated with an increased number of clefts and finger-like processes. Pits and short clefts linearly arranged towards the fiber tip were visible until the second week. This possibly indicates the linear elongation of the clefts by the fusion of adjacent pits to one another and to preexisting clefts. By the fourth week, the fiber ends had almost fully matured and displayed numerous cytoplasmic processes and lateral grooves.

Animals↗
PubMed1998

Considerations for surgical treatment of patients with upper lumbar disc herniations.

Nine patients treated by surgery for upper lumbar disc herniations were reviewed. Of nine patients with upper lumbar disc herniations at the L1-L2 or L2-L3 level, five were treated by anterior procedures, whereas four underwent posterior procedures. Four of the five patients on whom anterior procedures were performed underwent additional spinal instrumentation using the Kaneda device and Z-plate system. Clinical symptoms improved in all nine patients. Confirmation of the type and level of disc herniation and increased thoracolumbar kyphosis must be taken into consideration when the optimal surgical procedure and spinal instrumentation method are selected.

Adult↗
PubMed1998

Time lag between active joint inflammation and radiological progression in patients with early rheumatoid arthritis.

OBJECTIVE: To determine clinical variables useful in predicting the prognosis of patients with early rheumatoid arthritis (RA) by investigating the relationship between clinical variables and radiological progression. METHODS: One hundred eighteen patients with early RA whose symptoms developed within the previous year were enrolled in a prospective study. Data from the 98 patients who completed the 2 year study were analyzed, using the number of erosive joints and Larsen's score as the outcome of RA. RESULTS: Increases in the number of erosive joints at 12 months after entry into the study were significantly correlated with the number of swollen joints (r = 0.510), erythrocyte sedimentation rate (ESR) (r = 0.404), and C-reactive protein (CRP) (r = 0.487) at 6 months. The same results were seen using Larsen's score as the measure of outcome. The average number of erosive joints or mean Larsen's score at 12 months was higher in patients whose levels of CRP were high at 6 months and suppressed by 12 months, but increased much less in patients whose levels of CRP were successfully suppressed by 6 months. More joint erosions were noted in patients with positive rheumatoid factor (RF) than in RF negative patients. CONCLUSION: Joint erosions appeared with a certain time lag after active synovitis. Earlier introduction of effective treatment is recommended for the prevention of RA joint damage. The presence of RF, number of swollen joints, ESR, and levels of CRP at 6 months after starting therapy are the most useful variables to predict radiological progression in patients with early RA.

Arthritis, Rheumatoid↗
PubMed1998

[Properties of gas (CO2) microbubbles made by hand agitation and it's contrast enhancing effect].

The property of gas (CO2) microbubbles made by hand agitation and it's contrast enhancing effect of abdominal organs on gray scale ultrasound are here described. The size of microbubbles of CO2 gas adequately prepared with 5% human serum albumin was nearly 23 microns in mean diameter. However, the size and the density of gas microbubbles are affected with many factors, including mixing times, volume ratio of gas and liquid and the species of gas and liquid. On the other hand, contrast enhancing effect is determined by the size and the density of gas microbubbles. For the adequate evaluation of contrast enhancing effect of abdominal tumors by enhanced ultrasonography, the property of gas microbubbles described as above should be carefully considered.

Abdomen↗
PubMed1998

Possibility of independence in ADL (Activities of Daily Living) for patients with cervical spinal cord injuries--an evaluation based on the Zancolli Classification of Residual Arm Functions.

For patients with cervical spinal cord injuries to become independent in their ADL (Activities of Daily Living), residual arm function is very important. Also, age, sex, physical strengths, obesity, spasticity, pain, contracture and motivation are related. We investigated the possibility of independence in ADL for patients with cervical spinal cord injuries, carrying out our evaluation based on the Zancolli Classification of Residual Arm Functions. Zancolli classification C6BII is taken as the boundary level for ADL independence. Rehabilitation is not only controlled by the patients with cervical spinal cord injuries themselves but also by the ability of the rehabilitation staff. This implies that taking responsibility in rehabilitation important.

Activities of Daily Living↗
PubMed1998

Activation of myocardial and renal natriuretic peptides during acute intravascular volume overload in dogs: functional cardiorenal responses to receptor antagonism.

1. A family of structurally related but genetically distinct natriuretic peptides exist which include atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) of myocardial cell origin and C-type natriuretic peptide (CNP) of endothelial and renal epithelial cell origin. All three exert actions via cGMP, with ANP and BNP functioning via the natriuretic peptide A receptor and CNP via the natriuretic peptide B receptor. 2. Circulating and urinary natriuretic peptides were determined in response to acute intravascular volume overload (AVO). Additionally, their functional role in cardiorenal regulation during AVO was investigated by utilizing the natriuretic peptide receptor antagonist HS-142-1. Control (n=5) and study dogs (HS-142-1, n=9) underwent AVO with normal saline equal to 10% of body weight over 1 h. Both groups demonstrated similar significant increases in right atrial pressure, pulmonary capillary wedge pressure, pulmonary artery pressure and cardiac output. Circulating ANP paralleled increases in right atrial pressure and pulmonary capillary wedge pressure, with no changes in plasma BNP or CNP. At peak AVO, urinary CNP excretion was increased compared with baseline (7.0+/-4.2 versus 62+/-8.0 pg/min, P<0.05). 3. In the HS-142-1-treated group, plasma cGMP was decreased compared with the control group (9.6+/-1.1 to 5.0+/-1.2 pmol/ml, P<0.05). A significant attenuation of natriuresis (566+/-91 versus 1241+/-198 microEq/min, P<0.05) and diuresis (4.8+/-0.7 versus 10.1+/-2.0 ml/min, P<0.05) was also observed at peak AVO in the HS-142-1 treated group. 4. These findings support differential and selective responses of the three natriuretic peptides to AVO, in which plasma ANP and urinary CNP are markers for AVO. Secondly, these studies confirm the role of ANP and CNP but not BNP in the natriuretic and diuretic response to acute volume overload.

Animals↗
PubMed1997

Enzymatic characterization of human alpha1,3-fucosyltransferase Fuc-TVII synthesized in a B cell lymphoma cell line.

The human alpha1,3-fucosyltransferase, Fuc-TVII, a key enzyme in the biosynthesis of selectin ligands, was expressed as a soluble protein-A chimeric form in a human B cell lymphoma cell line, Namalwa KJM-1, and purified using IgG-Sepharose. The enzymatic properties of recombinant soluble Fuc-TVII were then examined. Its enzyme activity was highest at pH 7.5, and the presence of 25 mM Mn2+ was required for full activity. Fuc-TVII exhibits an acceptor specificity restricted to alpha2,3-sialylated type 2 oligosaccharides, and the apparent Km values for alpha2,3-sialyl lacto-N-neotetraose and GDP-fucose were 3.08 mM and 16.4 microM, respectively. The inhibitory effects of various nucleotides on the activity of Fuc-TVII reflected its donor specificity for the nucleotide portion of GDP. Fuc-TVII was demonstrated to be useful for the synthesis of a sialyl Lewis x hexasaccharide from lacto-N-neotetraose in combination with an alpha2, 3-sialyltransferase, ST3Gal IV. Polyethylene glycols enhanced the thermal stability of Fuc-TVII, leading to increased formation of the reaction product.

Burkitt Lymphoma↗
PubMed1997

Comparative gene mapping of the human and mouse TEP1 genes, which encode one protein component of telomerases.

The chromosomal locations of the human TEP1 (telomerase protein component 1) and mouse Tep1 genes, which were originally named TLP1 (telomerase protein 1) or TP1 (telomerase-associated protein 1), were determined by direct R-banding FISH and a molecular linkage analysis with interspecific backcross mice. The human TEP1 and mouse Tep1 genes were mapped by FISH to human chromosome 14q11.2 and to the C2D1 band of mouse chromosome 14, respectively. By means of genetic linkage mapping, the mouse gene was further localized as being 2.7 cM distal to D14Mit18 and D14Mit134 and 2.0 cM proximal to D14Mit5 on mouse chromosome 14, where conserved linkage homology with human chromosome 14q11-q12 has been identified.

Animals↗
PubMed1997

Detection of sarin hydrolysis products from sarin-like organophosphorus agent-exposed human erythrocytes.

A sarin-like organophosphorus agent, [bis(isopropyl methyl)phosphonate; BIMP], was synthesized. This agent has the same phosphonate group as sarin and also has the same anti-acetylcholinesterase activity potency as sarin. The ID50 and LD50 values of BIMP in mice after intravenous injection were 3.9 nM and 0.8 mg/kg, respectively. The AChE activities of their red blood cells and brains were dose-dependently reduced by intravenous BIMP. After preparation of experimental BIMP-exposed human red blood cells, BIMP-bound acetylcholinesterase (AChE) was solubilized from erythrocyte membranes, purified by immunoaffinity chromatography, digested with trypsin, and the sarin hydrolysis products bound to AChE were released by alkaline phosphatase digestion. The digested sarin hydrolysis products were subjected to trimethylsilyl (TMS) derivatization and detected by gas chromatography-mass spectrometry. Isopropyl methylphosphonic- and methylphosphonic acids, which are the sarin hydrolysis products, were detected in experimental BIMP-exposed human red blood cells. This new method, which enables sarin's hydrolysis products to be detected in BIMP-exposed erythrocytes, is a useful tool for studying sarin-poisoning victims.

Acetylcholinesterase↗
PubMed1997

Comparison of the effects of selective endothelin ETA and ETB receptor antagonists in congestive heart failure.

OBJECTIVES: This study was designed 1) to determine the extent to which endogenous endothelin (ET) affects hemodynamic, hormonal and body fluid balance through ETA and ETB receptors in congestive heart failure (CHF); and 2) to assess the therapeutic benefits and adverse effects of ET receptor antagonists for ETA and ETB on cardiorenal and neurohormonal variables. BACKGROUND: ET has two receptors, ETA and ETB, both of which are distributed in various tissues and cells. In vascular beds, ETA receptors mediate vasoconstriction, whereas ETB receptors mediate vasorelaxation. However, ETB receptors also exist in smooth muscle and mediate vasoconstriction. METHODS: We administered either the ETA receptor antagonist FR139317 (FR [n = 8], 1 and 10 mg/kg body weight) or the ETB receptor antagonist RES-701-1 (RES [n = 8], 0.2 and 1.5 mg/kg) to dogs with CHF induced by rapid ventricular pacing. The effects of both antagonists on cardiorenal and hormonal functions were studied. RESULTS: FR decreased cardiac pressures and the plasma atrial natriuretic peptide (ANP) level and increased cardiac output (CO). Urinary flow rate and urinary sodium excretion increased in association with an increase in the glomerular filtration rate and renal plasma flow (RPF). In contrast, RES increased cardiac pressures and decreased CO. It also decreased the plasma aldosterone level and RPF. Neither antagonist affected plasma norepinephrine levels. CONCLUSIONS: Endogenous ETs increase cardiac pressures and the retention of body fluid through ETA receptors in CHF. The vasodilative action through ETB receptors is overall functionally more important than the constrictive action through ETB receptors. ETs may regulate the secretion of ANP and aldosterone. Our findings suggest that selective ETA receptor antagonists have potential therapeutic benefits affecting both hemodynamic variables and diuresis, whereas ETB receptor antagonists have adverse hemodynamic effects, with the possibility of preventing fluid retention through suppression of aldosterone secretion in dogs with CHF.

Analysis of Variance↗
PubMed1997

Afadin: A novel actin filament-binding protein with one PDZ domain localized at cadherin-based cell-to-cell adherens junction.

A novel actin filament (F-actin)-binding protein with a molecular mass of approximately 205 kD (p205), which was concentrated at cadherin-based cell-to-cell adherens junction (AJ), was isolated and characterized. p205 was purified from rat brain and its cDNA was cloned from a rat brain cDNA library. p205 was a protein of 1,829 amino acids (aa) with a calculated molecular mass of 207,667 kD. p205 had one F-actin-binding domain at 1,631-1,829 aa residues and one PDZ domain at 1,016- 1,100 aa residues, a domain known to interact with transmembrane proteins. p205 was copurified from rat brain with another protein with a molecular mass of 190 kD (p190). p190 was a protein of 1,663 aa with a calculated molecular mass of 188,971 kD. p190 was a splicing variant of p205 having one PDZ domain at 1,009-1,093 aa residues but lacking the F-actin-binding domain. Homology search analysis revealed that the aa sequence of p190 showed 90% identity over the entire sequence with the product of the AF-6 gene, which was found to be fused to the ALL-1 gene, known to be involved in acute leukemia. p190 is likely to be a rat counterpart of human AF-6 protein. p205 bound along the sides of F-actin but hardly showed the F-actin-cross-linking activity. Northern and Western blot analyses showed that p205 was ubiquitously expressed in all the rat tissues examined, whereas p190 was specifically expressed in brain. Immunofluorescence and immunoelectron microscopic studies revealed that p205 was concentrated at cadherin-based cell-to-cell AJ of various tissues. We named p205 l-afadin (a large splicing variant of AF-6 protein localized at adherens junction) and p190 s-afadin (a small splicing variant of l-afadin). These results suggest that l-afadin serves as a linker of the actin cytoskeleton to the plasma membrane at cell-to-cell AJ.

Actins↗
PubMed1997

Neurotrophic 3,9-bis[(alkylthio)methyl]-and-bis(alkoxymethyl)-K-252a derivatives.

A series of 3,9 disubstituted [(alkylthio)methyl]- and (alkoxymethyl)-K-252a derivatives was synthesized with the aim of enhancing and separating the neurotrophic properties from the undesirable NGF (trk A kinase) and PKC inhibitory activities of K-252a. Data from this series reveal that substitution in the 3- and 9-positions of K-252a with these groups reduces trk A kinase inhibitory properties approximately 100- to > 500-fold while maintaining or in certain cases enhancing the neurotrophic activity. From this research, 3,9-bis[(ethylthio)methyl]-K-252a (8) was identified as a potent and selective neurotrophic agent in vitro as measured by enhancement of choline acetyltransferase activity in embryonic rat spinal cord and basal forebrain cultures. Compound 8 was found to have weak kinase inhibitory activity for trk A, protein kinase C1 protein kinase A, and myosin light chain kinase. On the basis of the in vitro profile, 8 was evaluated in in vivo models suggestive of neurological diseases. Compound 8 was active in preventing degeneration of cholinergic neurons of the nucleus basalis magnocellularis (NBM) and reduced developmentally programmed cell death (PCD) of female rat spinal nucleus of the bulbocavernosus motoneurons and embryonic chick lumbar motoneurons.

Animals↗
PubMed1997

Cytokine production regulating Th1 and Th2 cytokines in hemophagocytic lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis (HLH) is caused by the hyperactivation of T cells and macrophages. The clinical characteristics associated with this disease result from overproduction of Th1 cytokines including interferon-gamma (IFN-gamma), interleukin-2 (IL-2), and tumor necrosis factor-alpha (TNF-alpha). In this study, we analyzed the production of IL-12 and IL-4, which determine Th1 and Th2 response, respectively, and IL-10, which antagonizes Th1 cytokines, in 11 patients with HLH. IL-12 was detected in plasma in all patients (mean peak value, 30.0 +/- 5.0 pg/mL), while IFN-gamma was massively produced in nine patients (mean peak value, 79.2 +/- 112.0 U/mL). IL-4 was not detected in any of the patients. Plasma IL-10 levels were elevated in all patients (mean peak value, 2,698.0 +/- 3,535.0 pg/mL). There was a positive correlation between the levels of IFN-gamma and IL-10 (P < .01). The plasma concentrations of these cytokines were initially high, before decreasing after the acute phase. However, the decrease in IL-10 levels was slower than that of IFN-gamma. Although the concentration of IL-12 was high at the acute phase, in some patients, a peak in the level was delayed until the chronic phase. Thus, in HLH, production of cytokines that promote development of Th1 cells appears to be predominant over that for Th2 cell development. Overproduction of IL-10 was also observed indicating that a mechanism suppressing hyperactivation of Th1 cells and monocytes/macrophages functions in patients with this disease.

Child↗
PubMed1997

Induction of myelin-associated glycoprotein expression through neuron-oligodendrocyte contact.

The role of neurons on expression of myelin-associated glycoprotein (MAG) in oligodendrocytes and oligodendroglial differentiation was examined. Primary cultures of oligodendrocytes prepared from neonatal mouse brains were co-cultured with neuronal cells derived from embryonal carcinoma P19 cells. The levels of MAG mRNAs following this co-culture were determined by reverse transcription (RT)-PCR. In oligodendrocytes co-cultured in direct contact with P19-derived neurons, the levels of MAG mRNAs, particularly that of the L-type isoform, were markedly higher than those in cultures without any neuronal cells. On the other hand, when the P19-derived neurons were present, but not in direct contact, no significant induction of MAG expression was found, though oligodendrocytes appeared to mature morphologically. The L-MAG expression was also stimulated when just the neuronal cell membrane fraction was added, which implies that there might be some effecter(s) in the cell membrane which are possibly exerting a signal transduction for myelin formation. These results suggest that morphological differentiation and functional maturation of oligodendrocytes are due to independent factors. The former is caused by some humoral factor(s) liberated from neuronal cells, while the latter resulted from cellular contact with neuronal cells.

Animals↗