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Biomedical subjects

Y Kawamura

Publications and source records attributed to Y Kawamura.

At least 37 records · Page 2Linked to original sources
PubMed2003

Circulating endothelial cells in Kawasaki disease.

Recent reports have demonstrated that circulating endothelial cells (CECs) are observed in several diseases with vascular injury. Because Kawasaki disease (KD) is one type of systemic vasculitis, we hypothesized that an increased number of CECs may be associated with the appearance of complicated coronary artery lesions (CAL). In the present study we investigated the enumeration and origin of CECs in 20 patients with KD, using an immunohistochemical method with monoclonal antibodies: clone P1H12 against ECs and clone AC133 against endothelial progenitor cells (EPCs), which were derived from the bone marrow. The mean number of CECs increased significantly (P < 0.05) from the acute through the subacute phases of KD compared with both the convalescent phase of KD and healthy children. The mean number of CECs was significantly (P < 0.05) higher in six KD patients with CAL than in 14 KD patients without CAL. The population of EPCs in the total CECs in KD was 4.4 +/- 1.2% (range 0-18%). The number of EPCs during the subacute phase was also significantly higher (P < 0.05) in KD patients with CAL than in those without CAL. Our findings indicate that the number of CECs increase in KD vasculitis and suggest that the increased numbers of CECs and EPCs may reflect the EC damage of this disease.

Acute Disease↗
PubMed2002

Momentum distribution of 15B fragments from the breakup of 17B.

The two-neutron removal cross section (sigma(-2n)) and the longitudinal momentum distribution of 15B fragments from the breakup of 17B on 9Be were measured at 70A MeV. The distribution in the projectile rest frame is characterized by a FWHM of 80+/-10 MeV/c for 15B. The sigma(-2n) is found to be 0.22+/-0.05 b. A Glauber-type analysis of the data provides clear evidence of a two-neutron halo structure in 17B.

Journal Article↗
PubMed2002

Inflammatory change in the upper joint space in temporomandibular joint with internal derangement on gadolinium-enhanced MR imaging.

The object of this study was to clarify the relationship between gadopentetate dimeglumine (Gd-DTPA) contrast enhancement of the upper joint space and the severity of internal derangement of the temporomandibular joint (TMJ). Fifty patients with 63 painful TMJs underwent 1.5T MR imaging with T1-weighted images before and after an intravenous injection of Gd-DTPA with or without fat suppression. The relationship was investigated between the contrast enhancement at the upper joint space and disc position, disc morphology or bone morphology. Of the 63 joints, a significant contrast enhancement in the upper joint space was detected in 32 joints. There was a significant high incidence of anterior disc displacement without reduction in the contrast-enhancement positive group compared to the negative group (P = 0.021), but there was no significant difference for disc morphology (P = 0.094) and bone morphology (P = 0.384). Gd-DTPA enhanced MR imaging may potentially have diagnostic value for internal derangements of TMJs.

Adolescent↗
PubMed2002

Actual behaviour of N-butyl-2-cyanoacrylate (histoacryl) in a blood vessel: a model of the varix.

BACKGROUND AND STUDY AIMS: Though many gastric varices are treated endoscopically with n-butyl-2-cyanoacrylate, its behavior in varices is not known precisely. MATERIALS AND METHODS: We created a varix model. A volume of 0.7 ml or 1.4 ml of 71.4 % n-butyl-2-cyanoacrylate, a tissue adhesive, was injected into vinyl tubes of 0.4, 0.6, 0.9, and 1.2 cm in diameter, which were filled with still blood or flowing blood. The tissue adhesive was also injected into the inferior vena cava or femoral vein of dogs. RESULTS: N-butyl-2-cyanoacrylate was similarly polymerized in the vinyl tubes and the animal veins. A volume of 0.7 ml of the tissue adhesive could block all tubes up to 0.6 cm in diameter. A double quantity of the tissue adhesive could block tubes 0.9 and 1.2 cm in diameter, with flow velocities up to 10 cm/s and up to 5 cm/s, respectively. Some polymer masses were fragmented. CONCLUSIONS: One rapid shot of the tissue adhesive can block a vessel 0.6 cm or less in diameter with fast flow velocity, and a vessel up to 1.2 cm in diameter with slow flow velocity. Fast blood flows in a larger diameter vessel and slow injection of the tissue adhesive may result in fragmentation. This model of the varix was useful for assessing the effect of tissue adhesive used to treat gastric varices.

Animals↗
PubMed2002

Isolation and identification of some unknown substances in disposable nitrile-butadiene rubber gloves used for food handling.

In Japan, disposable gloves made from nitrile-butadiene rubber (NBR) are frequently used in contact with foods. In a previous paper, we investigated substances migrating from various gloves made of polyvinyl chloride, polyethylene, natural rubber and NBR. Zinc di-n-butyldithiocarbamate (ZDBC), diethyldithiocarbamate (ZDEC) used as vulcanization accelerators, di(2-ethylhexyl)phthalate (DEHP) used as a plasticizer and many unknown compounds that migrated from NBR gloves into n-heptane were detected by GC/MS. In this paper, six unknown compounds were obtained from one kind of NBR glove by n-hexane extraction and each was isolated by silica gel chromatography. From the results of NMR and mass spectral analysis of the six unknown compounds, their structures are proposed as 1,4-dione-2,5-bis(1,1-dimethylpropyl)cyclohexadiene (1), 2-(1,1-dimethylethyl)-4-(1,1,3,3-tetra methylbutyl)phenol (2), 2,6-bis(1,1-dimethylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol (3), 2,4-bis(1,1,3,3-tetramethylbutyl)phenol (4), 2-(1,1-dimethylethyl)4,6-bis(1,1,3,3-tetramethylbutyl)phenol (5) and 2,4,6-tris(1,1,3,3-tetramethylbutyl)phenol (6). Compound 1 was observed in five of the seven kinds of NBR gloves, and compounds 2-4 and 6, which are not listed in Chemical Abstract (CA), were present in four kinds of gloves.

Disposable Equipment↗
PubMed2002

Characteristic profile of intestinal microflora in Kawasaki disease.

UNLABELLED: To investigate whether the ecology of the intestinal microflora may change in the acute phase of Kawasaki disease (KD), the distribution pattern was studied of common micro-organisms in feces from 20 patients with KD, 20 patients with acute febrile diseases (disease control) and 20 healthy children. KD patients had a significantly lower (p < 0.001) incidence of Lactobacillus (2/20, 10%) than disease control patients (16/20, 80%) and healthy children (14/20, 70%). KD patients had no significant incidences of other microbial genera, compared with both disease control and healthy children. CONCLUSION: The results suggest that a lack or loss of the beneficial Lactobacillus genus in the enteric microflora may occur during the acute phase of KD.

Case-Control Studies↗
PubMed2001

Rubiscolin, a delta selective opioid peptide derived from plant Rubisco.

We found that the sequences YPLDL and YPLDLF in the large subunit of spinach D-ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) met the structure YP-aliphatic amino acid which might have opioid activity. We then synthesized these peptides to test their opioid activity. The IC(50) of these peptides in mouse vas deferens assay were 51.0 microM and 24.4 microM, respectively, and those in delta receptor binding assay using [(3)H]deltorphin II as radioligand were 2.09 microM and 0.93 microM, respectively. Both peptides were selective for delta receptor. We named them rubiscolin-5 and -6, respectively. Rubiscolin-5 and -6 have antinociceptive activity in mice after i.c.v. or oral administration. The enzymatic conditions to release rubiscolin were investigated using both spinach Rubisco and synthetic fragment peptides. This is the first example of bioactive peptides derived from plant Rubisco.

Analgesics↗
PubMed2001

A metabotropic glutamate receptor antagonist, alpha-methyl-4-carboxyphenylglycine, attenuates immediate early gene mRNA expression following traumatic injury in cultured rat cortical glial cells.

The effects of three glutamate receptor antagonists, (5R,10S)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]-cyclohepten-5,10-imine hydrogen maleate (MK-801) for the N-methyl-D-aspartate receptor, 1,2,3,4-tetrahydro-6-nitro-2,3-dioxo-benzo[f] quinoxaline-7-sulfonamide (NBQX) for the alpha-amino-3-hydroxy-5methyl-4-isoxazole propionate /kinate receptor and (S)-alpha-methyl-4-carboxyphenylglycine (MCPG) for the metabotropic receptor, on c-fos and c-jun mRNA expression were investigated in cultured cortical glial cells following traumatic scratch injury. Expression of the two genes along the edges of wounds detected by in situ hybridization was not affected by MK-801 and NBQX. However, 100 and 500 microM of MCPG remarkably reduced the hybridization signals for both c-fos and c-jun mRNAs. The present results suggest that group I metabotropic glutamate receptors might have some association with immediate early gene induction after in vitro traumatic injury in glial cells.

Animals↗
PubMed2001

Examination of intra-gastrointestinal tract signal elimination in MRCP: combined use of T(1)-shortening positive contrast agent and single-shot fast inversion recovery.

To examine the effects of removing the gastrointestinal signal in MR cholangiopancreatography (MRCP), investigations were carried out on the combined use of T(1)-shortening intestine-positive contrast medium, FerriSeltz with ferric ammonium citrate as the main component, and high-speed imaging using single-shot fast inversion recovery (SSFIR). The contrast effect was significantly elevated to 10.2 +/- 1.6 after administration, compared with 5.9 +/- 2.4 before administration (P < 0.001). The enhancement effect was also significantly elevated to 13.2 +/- 3.0 after administration, compared with 4.9 +/- 3.1 before administration (P < 0.001). These results were obtained because the null point of FerriSeltz aqueous solution (5.97 mmol/L) was in the range of approximately 180 msec. With the present method, adequate suppression of the signal intensity of the digestive tract was obtained relatively easily with MRCP, and the technique was found to be effective. J. Magn. Reson. Imaging 2001;13:738-743.

Adult↗
PubMed2001

Time course of arterial hyperintensity with fast fluid-attenuated inversion-recovery imaging in acute and subacute middle cerebral arterial infarction.

The purpose of this study was to evaluate the time course of arterial hyperintensity (AH) in acute and subacute cerebral infarctions of the middle cerebral artery (MCA) distribution by using fast fluid-attenuated inversion-recovery (FLAIR) imaging. A total of 40 FLAIR MR examinations were performed in 27 patients with MCA infarction within 13 days after ictus. Thirteen patients underwent two MR examinations during this period. Thrombotic or embolic infarctions were included in this study, but lacunar infarctions were excluded. The presence or absence of AH and the location of AH were analyzed. Overall, AH was found in 24 (60%) of 40 FLAIR examinations within 13 days after onset. AH was seen in 17 (100%) examinations less than 24 hours old, four (40%) of 10 examinations 1-4 days old, two (18%) of 11 examinations 5-9 days old, and one (50%) of two examinations 10-13 days old. AH was most frequently found at the sylvian fissure (87%), followed by the sulci (54%), and the horizontal segment of MCA (29%) in the affected MCA distribution. Although AH could be seen even at 13 days after ictus, the presence of AH declined over time. AH represented an early sign of acute embolic or thrombotic infarction. J. Magn. Reson. Imaging 2001;13:987-990.

Aged↗
PubMed2001

Carbohydrate-mediated adhesion of human colon carcinoma cells to human liver sections.

Clinicopathological observations have revealed that the expression level of a carbohydrate antigen recognized by the monoclonal antibody (mAb) FH6 in colorectal carcinomas is higher at advanced stages than at early stages. The present study aimed to elucidate whether human colon carcinoma cell surface glycans recognized by mAb FH6 determine the ability of these cells to adhere to sections of human liver. Variant human colon carcinoma cell lines selected for high and low binding of mAb FH6 were compared with respect to their adhesive capacity. The cells expressing the higher level of FH6 binding also showed a greater ability to adhere to liver sections. This adhesion was not blocked by anti-E-selectin monoclonal antibodies, but pretreatment of the carcinoma cells with endo-beta-galactosidase significantly reduced both cell surface binding of mAb FH6 and the ability of the cells to adhere to liver sections. Our observations suggest that endo-beta-galactosidase-sensitive carbohydrate chains containing an epitope recognized by mAb FH6 play an important role in the adhesion of human colon carcinoma cells to human liver sections. Whether these interactions have any relationship to the mechanism(s) of liver metastasis remains to be elucidated.

Animals↗
PubMed2001

Polycystic kidney rat is a novel animal model of Caroli's disease associated with congenital hepatic fibrosis.

Caroli's disease (congenital intrahepatic biliary dilatation) associated with congenital hepatic fibrosis is an autosomal recessive polycystic kidney disease. Recently, the polycystic kidney (PCK) rat, a spontaneous mutant derived from a colony of CRJ:CD rats with polycystic lesions in the liver and an autosomal recessive mode of inheritance, was reported. In the present study, the pathology of the hepatobiliary system and the biliary cell-kinetics were evaluated in fetuses (day 18 to 21 of gestation) and neonates and adults (1 day to 4 months after delivery) of PCK rats. CRJ:CD rats were used as a control. Multiple segmental and saccular dilatations of intrahepatic bile ducts were first observed in fetuses at 19 days of gestation. The dilatation spread throughout the liver and the degree of dilatation increased with aging. Gross and histological features characterizing ductal plate malformation were common in the intrahepatic bile ducts. Overgrowth of portal connective tissue was evident and progressive after delivery. These features were very similar to those of Caroli's disease with congenital hepatic fibrosis. Proliferative activity in the biliary epithelial cells was greater in PCK rats than controls during the development. In contrast, the biliary epithelial apoptosis was less extensive in PCK rats than the controls until 1 week after delivery, but greater after 3 weeks, suggesting that the remodeling defect in immature bile ducts associated with the imbalance of cell kinetics plays a role in the occurrence of intrahepatic biliary anomalies in PCK rats. The PCK rat could be a useful and promising animal model of Caroli's disease with congenital hepatic fibrosis.

Animals↗
PubMed2001

Angiotensin-converting enzyme inhibition improves defective angiogenesis in the ischemic limb of spontaneously hypertensive rats.

OBJECTIVES: Natural angiogenesis has been shown to be impaired in spontaneously hypertensive rats (SHR). The purpose of this study was to determine whether pathological angiogenesis in the setting of tissue ischemia is also impaired in SHR, and to what extent it is modified by angiotensin-converting enzyme (ACE) inhibition. METHODS: Ischemia was induced in the hindlimb of SHR by excision of the femoral artery, after which the animals were randomly assigned to receive low-dose perindopril (sub-antihypertensive, 0.2 mg/kg/day), high-dose perindopril (antihypertensive, 2.0 mg/kg/day), or vehicle for 3 weeks. Wistar-Kyoto rats (WKY) with femoral artery excision served as a control group. RESULTS: Tissue ACE activity in SHR was significantly increased compared to WKY (49.4+/-6.2 vs. 34.0+/-14.2 IU/mg, P<0.01). Administration of perindopril significantly reduced ACE activity in SHR (low dose: 12.4+/-2.3; high dose: 11.0+/-2.1 IU/mg, P<0.005). Angiogenesis of the ischemic limb muscles was significantly impaired at 4 weeks in SHR versus WKY as indicated by the lower capillary density in the former (364.5+/-43.0 vs. 463.8+/-63.0/mm(2), P<0.05) as well as the reduced hindlimb perfusion assessed by laser Doppler imaging (0.86+/-0.08 vs. 1.03+/-0.09, P<0.05). Administration of perindopril significantly augmented both the capillary density (low dose: 494.3+/-69.8; high dose: 543.9+/-76.9/mm(2), P<0.005) and the limb perfusion (low dose: 1.06+/-0.15; high dose: 1.05+/-0.12, P<0.05) of the ischemic limb in SHR. CONCLUSIONS: These findings indicate that pathological angiogenesis in the setting of tissue ischemia is impaired in SHR compared with WKY, and that this impairment can be reversed by ACE inhibition. The angiogenic properties of an ACE inhibitor may benefit patients with essential hypertension presenting with lower limb vascular insufficiency.

Analysis of Variance↗
PubMed2001

Nucleotide sequence of BamHI family satellite DNA and its unit length polymorphism in bluegill sunfish Lepomis macrochirus.

We have isolated and sequenced a member of tandem repetitive DNA containing BamHI site (BamHI family satellite DNA) from bluegill sunfish Lepomis macrochirus. PCR amplification with specific primers was performed to define the size of unit length repeat of the BamHI family satellite DNA, revealing that there were two distinct size of DNA fragments (0.9 kb and 1.3 kb) in the PCR products. The longer fragment (1.3 kb) consisted of internal sub-duplication of shorter fragment (0.9 kb). We have compared the size of PCR products among four fish populations, and found that both fragments co-existed in one population whereas the longer fragment was dominant in other three populations. The results may reflect ongoing homogenization of satellite DNA type over a short evolutionary time scale.

Animals↗
PubMed2001

Scanning electron microscopy description of a new species of Demodex canis spp.

Between 1997 and 1999, the prevalence of Demodex canis mites was determined in 150 dogs. In two dogs, we found two different species of mites; Demodex canis and another, unidentified, Demodex mite. The unidentified Demodex mite species had several different morphological features. First, it had a short opisthosoma and an obtuse end. In addition, the fourth coxisternal plate was rectangular and there was a band-like segmental plate between the fourth coxisternal plate and opisthosoma. Although all of the morphology and the development of male mites could not be investigated in this study, the location of the opisthosoma and the genital pore clearly differed from Demodex canis, suggesting that this unidentified mite is a new species.

Animals↗