Biomedical subjects

S Kawashima

Publications and source records attributed to S Kawashima.

At least 109 records · Page 6Linked to original sources

PubMed1999

CT examination of the guttural pouch (auditory tube diverticulum) in Przewalski's Horse (Equus przewalskii).

The domestic horse (Equus caballus) have the large symmetrical guttural pouches (the auditory tube diverticulum) formed by saccate bulge of the auditory tube. In this study, CT examination was carried out in the head of Przewalski's horse (Equus przewalskii), the only true wild horse living at present. As results of the examination, Przewalski's horse possessed the large symmetrical guttural pouches divided into medial and lateral compartments by the stylohyoid bone. Moreover, the right and left guttural pouches meet each other at the median part to form a thin septum. As CT sections get close to the part of the occipital condyle, the lateral compartment disappeared, and the medial compartment gradually became small toward the base of the skull. These results indicate that the nuchal-basal part of the medial compartment is not well-developed as compared with the domestic horse.

Animals↗

PubMed1999

Skull morphology and mitochondrial DNA sequence analysis in the lesser Japanese mole (Mogera imaizumii) from the Imperial Palace (Tokyo, Japan).

Since about 1630, the Imperial Palace has been biologically isolated from other habitats by the development and urbanization of Tokyo. We morphologically examined the skulls of the lesser Japanese mole (Mogera imaizumii) from the Imperial Palace and compared them with those from Kanto District, while the sequences of the cytochrome b and 12S rRNA genes were also analyzed to clarify the genetic status of this isolated population. The skulls from the Imperial Palace were much larger than those from Kanto District in the length items. We suggest that the Imperial Palace skulls morphologically may compose a cluster as a large body-sized type in Kanto District within the dots of Mogera imaizumii in charts of principal component analysis. The mitochondrial DNA sequences of the Imperial Palace population were highly homologous to those of other Tokyo population at the level of 98.5% in cytochrome b and 98.7% in 12S rRNA genes.

Animals↗

PubMed1999

Development of X-ray TV M-mode and reconstructed ultrasound M-mode methods for investigating tongue movement during swallowing in humans.

There were two purposes of this study. The first purpose was to introduce the "X-ray TV M-mode waveform" which is reconstructed from sequential X-ray TV images and the "reconstructed ultrasound M-mode waveform" which is delivered from ultrasound B-mode images. The second purpose was to evaluate the usefulness of these two types of waveforms in the investigation of tongue movement during swallowing. The instrument system employed in this study consisted of ultrasound and X-ray TV synchronized by a time marker. After the X-ray images and ultrasound B-mode images were recorded on an optical disk, X-ray TV M-mode waveform and ultrasound M-mode waveform were reconstructed using an MC 68030/OS-9 computer. No significant differences in quality of images were observed between the X-ray TV M-mode waveform and the reconstructed ultrasound M-mode waveform. Therefore, both waveforms of the X-ray TV M-mode and the reconstructed ultrasound M-mode are equally useful in measuring tongue movement.

Adult↗

PubMed1999

Clinical findings in Japanese children with obstructive sleep apnea syndrome: focus on dental findings.

We evaluated clinical findings including those on dentistry and in the oral cavity of children with obstructive sleep apnea syndrome (OSA). This study examined twenty-seven OSA children, who were advised by otolaryngologists to be admitted for closer examination and showed an apnea index (AI) of 5 or more on polysomnographs. Their clinical history was obtained from their mothers, and oral findings were also evaluated. The patient consisted of 15 males (56%) and 12 females (44%). The mean body mass index (BMI) was 16.0 +/- 3.0. Of the clinical findings related to sleeping and the duration of sleeping, snoring was the most frequently observed finding (100%). The mean duration of sleep, calculated from the time they went to bed (9.2 +/- 0.8 p.m.) and the time they got up (7.1 +/- 0.8 a.m.), was 9.9 +/- 1.0 hours. Of the clinical findings obtained during the daytime, hyponasal speech was the most frequently observed finding (74%). In terms of dentistry, oral breathing was the most frequently observed finding (89%). The mean duration of meals was 31.7 +/- 13.8 minutes. Results of oral examination revealed that Hellman's dental age was most frequently IIA. According to the standardized grading classification, grade I was observed in 7%, II in 63%, and grade III in 30% of subjects.

Age Determination by Teeth↗

PubMed1999

Tyrosine kinase is essential for the constitutive expression of type I interleukin-1 receptor in human fibroblast cells.

The effect of genistein, an inhibitor of tyrosine kinase, on the constitutive expression of type I interleukin-1 receptor (IL-1RI) was examined in the human lung fibroblast cell line TIG-1, which has been shown to express only type I IL-1R. Genistein inhibited the 125I-labeled IL-1alpha binding to TIG-1 cells in both a time and dose dependent manner. Scatchard plot analysis revealed that the number of IL-1RI decreased with no change in binding affinity. Genistein did not affect the level of IL-1RI mRNA, and cycloheximide did not inhibit the down-regulatory effect of genistein. These results indicate that genistein inhibits IL-1RI expression, not at the transcriptional level, but at the post-translational level. IL-1RI expression, IL-1R associated kinase (IRAK) activity and IL-1-induced-IL-6 production were all down-regulated by pretreatment with genistein. These findings indicate that tyrosine kinase activity is essential for the constitutive expression of functional IL-1RI.

Cells, Cultured↗

PubMed1999

[A new method for quantification of metamorphopsia in patients with epiretinal membrane].

PURPOSE: We have developed a new method for quantification of metamorphopsia and applied it to study distorted vision resulting from epiretinal membrane (ERM). PATIENTS AND METHODS: We prepared a modified Amsler chart, which was a square grid formed by black lines on a white background with 12 cm on a side and divided into 2 cm quadrants. The patients were asked to trace any straight lines on the chart which appeared irregular or curved. The length of all lines traced by the patients was measured except for the outer frame. The total length of the chart itself was 1,200 mm, but it would appear longer in patients with metamorphopsia. In addition, the severity of metamorphopsia was scored subjectively as follows: 1, absent; 2, slight; 3, mild; 4, moderate; and 5, severe. The relationship of the length to the score and to the visual acuity were analysed. Sixty-three patients with unilateral ERM were examined. RESULT: The length of the line ranged from 1,200 to 1,259 mm (mean 1,223.3 mm) and was correlated significantly to the score. CONCLUSION: This method might be applied usefully in evaluating the severity of metamorphopsia and the surgical outcome of eyes with ERM.

Adolescent↗

PubMed1999

[A new prediction method for the total pollen counts of Cryptomeria japonica based on variation in annual summertime temperature].

In order to predict the total pollen counts of Cryptomeria japonica, we examined the difference of summertime temperature between the previous year and the year before the previous. Correlation coefficients of nine points throughout Japan exceeded more than r = 0.84 when compared the total pollen counts obtained from prediction and those from observation. The best correlation at four out of nine places was obtained with mean temperature of July, however, mean temperature of August or maximum temperature of August (or July) exceeded at some places. The differences, between observed values and predicted values are within 1000 grains/cm2 in 101 cases out of 135 cases (75%). Prediction errors at the year of bumper crop of male flower were less than 40% and the average is 17.5%. It is considered that our new method is useful enough for prediction, especially, the year of bumper crop of male flower.

Air Pollutants↗

PubMed1999

Genome-scale Gene Expression Analysis and Pathway Reconstruction in KEGG.

The massively parallel hybridization technologies by DNA chips and microarrays make it possible to monitor expression patterns of the whole set of genes in a genome under various conditions. The vast amount of data generated by such technologies necessitates the development of a new database management system that integrates expression data with other molecular biology databases and various analysis tools. We report here an extension of our KEGG (Kyoto Encyclopedia of Genes and Genomes) and DBGET/LinkDB systems for analyzing gene expression data in conjunction with pathway information and genomic information. It is now possible to make use of expression data for the reconstruction of pathways from the complete genome sequences.

Journal Article↗

PubMed1998

Hypotension and reduced nitric oxide-elicited vasorelaxation in transgenic mice overexpressing endothelial nitric oxide synthase.

Nitric oxide (NO), constitutively produced by endothelial nitric oxide synthase (eNOS), plays a major role in the regulation of blood pressure and vascular tone. We generated transgenic mice overexpressing bovine eNOS in the vascular wall using murine preproendothelin-1 promoter. In transgenic lineages with three to eight transgene copies, bovine eNOS-specific mRNA, protein expression in the particulate fractions, and calcium-dependent NOS activity were confirmed by RNase protection assay, immunoblotting, and L-arginine/citrulline conversion. Immunohistochemical studies revealed that eNOS protein was predominantly localized in the endothelial cells of aorta, heart, and lung. Blood pressure was significantly lower in eNOS-overexpressing mice than in control littermates. In the transgenic aorta, basal NO release (estimated by Nomega-nitro-L-arginine-induced facilitation of the contraction by prostaglandin F2alpha) and basal cGMP levels (measured by enzyme immunoassay) were significantly increased. In contrast, relaxations of transgenic aorta in response to acetylcholine and sodium nitroprusside were significantly attenuated, and the reduced vascular reactivity was associated with reduced response of cGMP elevation to these agents as compared with control aortas. Thus, our novel mouse model of chronic eNOS overexpression demonstrates that, in addition to the essential role of eNOS in blood pressure regulation, tonic NO release by eNOS in the endothelium induces the reduced vascular reactivity to NO-mediated vasodilators, providing several insights into the pathogenesis of nitrate tolerance.

Animals↗

PubMed1998

Multiple processing of procathepsin L to cathepsin L in vivo.

Three amino-terminal-specific peptidic antibodies against cathepsin L were generated. These antibodies recognize in vitro processing products of procathepsin L in time-course-dependent fashion. Immunoblot analyses with these antibodies followed by immunoprecipitation with anti-cathepsin L antibody showed that the amino terminal amino acid sequences of intracellular cathepsin L are heterogeneous: the single chain form of cathepsin L starts with either EPLML, LKIPK or IPKSV, and the heavy chain of the two chain form with IPKSV. Percoll density gradient and fluorescence immunohistochemistry suggested that these three species of cathepsin L localize in the lysosomes where procathepsin L processing occurs.

3T3 Cells↗

PubMed1998

Activity-dependent survival and enhanced turnover of calcium in cultured rat cerebellar granule neurons.

Neurons survive when their activity is maintained. An influential hypothesis on the cellular mechanism underlying this phenomenon is that there is an appropriate range of intracellular Ca2+ concentration ([Ca2+]i) for survival. The rat cerebellar granule neuron in culture serves as the most often used model system for the analysis of activity-dependent survival, since it does not survive unless an excitant (KCl or glutamate) is added to the culture medium. Against the above-mentioned hypothesis, we found in our previous examination no difference between steady-state [Ca2+]i in granule neurons cultured under high KCl (i.e., survival) and low KCl (i.e., death) conditions. In this report, we present the quantitative background of unchanged [Ca2+]i between the two culture conditions. Influx of Ca2+ due predominantly to L-type voltage-dependent calcium channels was higher in high KCl cultures than in low KCl cultures. At the same time, efflux of Ca2+ due to the activity of Ca2+/Na+ antiport was also higher in high KCl cultures. Additionally, we found that the endocytotic activity was greater in high KCl cultures than in low KCl cultures, as monitored by the rate of uptake of horseradish peroxidase added to medium. Since the uptake was blocked by an internal Ca2+ chelator, the increased endocytotic activity in high KCl cultures might be a consequence of the enhanced Ca2+ turnover.

Animals↗

PubMed1998

A new NEDD8-ligating system for cullin-4A.

NEDD8 is a ubiquitin (Ub)-like protein. Here we report a novel ubiquitinylation-related pathway for modification by NEDD8. NEDD8 was activated by an E1 (Ub-activating enzyme)-like complex, consisting of APP-BP1 and hUba3 with high respective homologies to the amino- and carboxy-terminal regions of E1 and then linked to hUbc12 (a human homolog of yeast Ub-conjugating enzyme Ubc12p). The major target protein modified by NEDD8 was found to be Hs-cullin-4A (Cul-4A), a member of the family of human cullin/Cdc53 proteins functioning as an essential component of a multifunctional Ub-protein ligase E3 complex that has a critical role in Ub-mediated proteolysis.

Amino Acid Sequence↗

PubMed1998

Purification, molecular cloning, and characterization of TRP32, a novel thioredoxin-related mammalian protein of 32 kDa.

We purified a protein of 32 kDa from human thymoma HPB-ALL cells that was co-purified with a catalytic fragment of MST (mammalian STE-20-like), a kinase of the STE20 family, which is proteolytically activated by caspase in apoptosis (Lee, K.-K., Murakawa, M., Nishida, E., Tsubuki, S., Kawashima, S., Sakamaki, K., and Yonehara, S. (1998) Oncogene 16, in press). Molecular cloning of the gene encoding this 32-kDa protein (TRP32) reveals that it is a novel protein of 289 amino acid residues and contains an NH2-terminal thioredoxin domain with a conserved thioredoxin active site. The human and mouse TRP32 proteins have 99% homology, and the thioredoxin domains are completely identical. The thioredoxin domain of TRP32 has thioredoxin-like reducing activity, which can reduce the interchain disulfide bridges of insulin in vitro. However, the thioredoxin domain of TRP32 is more sensitive to oxidation than human thioredoxin. Northern blot analysis showed that TRP32 is expressed in all human tissues. Expression of TRP32 was also confirmed in all mammalian cell lines tested by Western blot analysis using anti-TRP32 monoclonal antibody. Subcellular fractionation and immunostaining analysis showed TRP32 is cytoplasmic protein. These findings suggest that TRP32 is a novel cytoplasmic regulator of the redox state in higher eukaryotes.

Amino Acid Sequence↗

PubMed1998

Proteolytic activation of MST/Krs, STE20-related protein kinase, by caspase during apoptosis.

The Fas system has been extensively investigated as a model of apoptosis and the caspase cascade has been shown to be a characteristic mechanism of signaling of apoptosis. We have identified and purified a kinase that was activated after the stimulation of Fas on human thymoma-derived HPB-ALL cells. Partial amino acid sequencing of the purified kinase revealed it to be MST/Krs, member of the yeast STE20 family of protein kinases. MST/Krs was activated by proteolytic cleavage and proteolytic activation was blocked by the caspase inhibitor, Z-VAD-FK. A mutant MST with Asp-->Asn replacement at a putative caspase cleavage site was resistant to either the proteolytic cleavage or the activation of the kinase activity. These findings suggest that proteolytic activation is one activation mechanism of MST and plays a role in apoptosis.

Amino Acid Sequence↗

PubMed1998

Transient up-regulation of a prolyl endopeptidase activity in the microsomal fraction of rat liver during postnatal development.

To identify proteases which are involved in cell proliferation and differentiation of liver cells, we assayed various protease activities in rat liver during its postnatal development. We found that a protease activity specific to proline residues in the microsomal fraction of rat liver was transiently increased around postnatal day 8 and decreased thereafter, indicating that the enzyme activity is highly correlated to the proliferation and differentiation of liver cells. This protease was purified to an apparent homogeneity from the microsomal fraction of the postnatal-day-8 rat liver. The purified enzyme gave a single band with an apparent molecular mass of 65,000 on SDS/PAGE. It cleaved several peptide 4-methylcoumaryl-7-amide substrates and bioactive peptides at the C-terminus of proline residues. The enzyme did not hydrolyze any protein substrate examined suggesting that it is a peptidase rather than a proteinase. Although the best substrate among those tested was succinyl-Gly-Pro-Leu-Gly-Pro-4-methylcoumaryl-7-amide (-NH-Mec), the purified enzyme did not hydrolyze succinyl-Gly-Pro-NH-Mec, indicating that the enzyme has different substrate specificity from any hitherto known prolyl endopeptidases. These results suggest that the purified enzyme is a unique prolyl endopeptidase which may be involved in proliferation and differentiation of liver cells.

Animals↗

PubMed1998

Polymorphism of the NADH/NADPH oxidase p22 phox gene in patients with coronary artery disease.

BACKGROUND: Oxidative stress in the vasculature has been implicated in the pathogenesis of coronary artery disease (CAD). NADH/NADPH oxidase is a key enzyme of superoxide production in the vasculature. p22 phox, an essential component of NADH/NADPH oxidase, has four types of polymorphism. The C242T polymorphism changes histidine-72 to tyrosine, located in the potential heme-binding sites, whereas A640G polymorphism is located in the 3' untranslated region. METHODS AND RESULTS: We investigated whether these polymorphisms were associated with risk of CAD by use of restriction fragment length polymorphism (RFLP). The prevalence of the TC + TT genotype of the C242T polymorphism was significantly more frequent in control subjects (n=201) than in the patients with CAD (n=201). The odds ratio of the TC + TT versus CC genotype of the C242T polymorphism between control subjects and case patients was 0.49 (95% CI, 0.28 to 0.87) (P=.015). The prevalence of the genotypes of the A640G polymorphism was not different between groups. The association of C242T polymorphism of the p22 phox gene with CAD was statistically significant and independent of other risk factors. CONCLUSIONS: The mutation of the potential heme-binding site of the p22 phox gene may reduce susceptibility to CAD. Our observations suggest that the C242T polymorphism of the p22 phox gene is a novel genetic marker that has a protective effect on coronary risk.

Case-Control Studies↗

PubMed1998

Transforming growth factor-beta1 and protein kinase C synergistically activate the c-fos serum response element in myocardial cells.

We previously reported that transforming growth factor-beta1 (TGF-beta1) potentiated alpha1-adrenergic and stretch-induced c-fos mRNA expression and norepinephrine (NE)-induced amino acid incorporation in rat cultured myocardial cells (MCs). In the present study, we attempted to explore the mode of TGF-beta1 action for c-fos gene expression in MCs. In the transient transfection assay, TGF-beta1 potentiated NE- or 12-O-tetradecanoylphorbol-13-acetate (TPA)-activated c-fos promoter/enhancer, but not forskolin-activated c-fos promoter/enhancer. The c-fos serum response element (SRE) and the TPA response element (TRE) were responsible for TGF-beta1-induced potentiation of the NE or TPA action. Although TGF-beta1 activated not only the wild-type c-fos SRE, but also the mutated c-fos SRE, which contains an intact binding site for the serum response factor (SRF) but lacks the ternary complex factor (TCF) binding site, TPA activated the wild-type c-fos SRE but not the mutated c-fos SRE. TGF-beta1 did not potentiate the effects of TPA on the activation of mitogen-activated protein kinase (MAPK) and the phosphorylation of Elk-1 and SAP-1a, which belong to TCF at the c-fos SRE. These results indicate that TGF-betaf potentiates the c-fos SRE activated by PKC through the SRF binding site. TGF-beta1 is involved in the regulation of c-fos gene expression through the c-fos SRE and is subsequently involved in the regulation of the gene which has the TRE in the promoter/enhancer region.

Animals↗

PubMed1998

Infected atherosclerotic ulcer of the abdominal aorta as a cause of mycotic aneurysm treated by in-situ prosthetic graft reconstruction: report of a case.

A 68-year-old man with an infrarenal mycotic aneurysm underwent successful in-situ graft reconstruction using a woven Dacron graft. A tissue culture taken from the excised aortic wall revealed Staphylococcus epidermidis, and histological study subsequently showed penetrating atherosclerotic ulcers (PAU) involving all layers of the aortic wall and marked neutrophilic infiltration with abscess formation inside the ulcer. Atherosclerotic aortic lesions such as PAU are considered susceptible to bacterial infection, which may lead to the formation of an aneurysm after destruction of the vessel wall. Hence, elderly hypertensive patients, being at high risk for such aortic pathology, require careful studies performed to assess the aorta. The usefulness of computed tomographic (CT) scans to determine the presence of PAU or surrounding inflammation should be borne in mind even when a small mycotic aneurysm exists.

Aged↗