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K Murase

Publications and source records attributed to K Murase.

At least 73 records · Page 4Linked to original sources
PubMed2000

Expression of nuclear factor-kappaB in Helicobacter pylori-infected gastric mucosa detected with southwestern histochemistry.

BACKGROUND: The transcription factor nuclear factor-kappaB (NF-kappaB) plays a pivotal role in inflammatory responses by upregulating mRNA expression of, for example, proinflammatory cytokines and chemokines. Although in vitro studies have shown that Helicobacter pylori can induce NF-kappaB activation in gastric cancer cell lines, there is little information on cellular localization of NF-kappaB in H. pylori-infected gastric mucosa. METHODS: H. pylori-infected and -negative patients with various endoscopic findings were examined. NF-kappaB expression was studied by means of Southwestern histochemistry, a new method of localizing transcription factors. Labeled double-stranded oligo-DNA with specific consensus sequence for the NF-kappaB binding site was reacted with frozen sections from gastric biopsy specimens. We compared mucosal interleukin-8 (IL-8) and IL-1beta levels as measured with enzyme-linked immunosorbent assay with the degree of NF-kappaB expression. RESULTS: NF-kappaB expression was often evident in nuclei of epithelial cells in H. pylori-infected gastric mucosa. The degree of NF-kappaB expression on the epithelium was significantly more severe in H. pylori-infected than in -negative mucosa. The degree of NF-kappaB expression also correlated with mucosal IL-8 levels but not with IL-8. CONCLUSIONS: H. pylori infection increases the expression of NF-kappaB in gastric mucosa, suggesting that NF-kappaB is involved in inflammatory responses to H. pylori.

Enzyme-Linked Immunosorbent Assay↗
PubMed2000

The changes in glycosylation after partial hepatectomy enhance collagen binding of vitronectin in plasma.

Vitronectin is a multifunctional glycoprotein present in the extracellular matrix and plasma. Changes in rat vitronectin were studied during liver regeneration after partial hepatectomy. Carbohydrate concentrations of vitronectin decreased to 2/3 of sham-operated rats at 24 h after partial hepatectomy. Carbohydrate composition and lectin reactivity indicated that N-glycosylation and sialylation of vitronectin changed markedly after partial hepatectomy, while amino acid composition did not change significantly. We previously showed that deN-glycosylation of vitronectin in vitro affects collagen binding among various ligands (Yoneda et al., Biochemistry (1998) 37, 6351-6360). Vitronectins from partially hepatectomized rats at 24 h were found to exhibit markedly enhanced binding to type I collagen. The effect of sialylation on collagen binding was further examined using enzymatically deglycosylated vitronectin of nonoperated rats. Collagen binding increased by 1.2 times after deN-glycosylation of vitronectin, while it increased more than 2.9 times after desialylation. Various glycosyltransferases in liver are known to change after partial hepatectomy, including the attenuation of N-oligosaccharide transferase. The findings therefore suggest that the collagen binding of vitronectin is modulated by the alteration of peptide glycosylation caused by postoperative physiological changes of glycosyltransferases and that the change may contribute to tissue remodeling processes.

Amino Acids↗
PubMed2000

Tc-99m PMT hepatobiliary scintigraphy in the differential diagnosis of extrahepatic metastases and hepatocellular carcinoma.

PURPOSE: The authors evaluated the utility of hepatobiliary scintigraphy for tissue characterization of extrahepatic metastases from hepatocellular carcinoma (HCC) using Tc-99m N-pyrydoxyl-5-methyltriptophane (Tc-99m PMT). METHODS: We examined 13 patients with HCC (29 extrahepatic metastases and 3 benign bone lesions) and 5 patients with other cancers (15 extrahepatic metastases). Thirty minutes to 6 hours after intravenous administration of Tc-99m PMT, planar (all 47 lesions) and SPECT (42 lesions) images were obtained. Accumulation of Tc-99m PMT in the lesion was evaluated visually by comparing bone scintigraphy, computed tomography, magnetic resonance imaging, or all of these. RESULTS: Findings were positive in 12 of 13 patients with HCC and extrahepatic metastases (16 of 29 on planar imaging and 21 of 26 on SPECT). Findings in all three benign bone lesions and 15 metastatic lesions from non-HCC primary lesions were negative (0 of 18 on planar imaging, 0 of 16 on SPECT). There were no false-positive findings in these lesions. Lesion-by-lesion sensitivity, specificity, accuracy, and positive and negative predictive values were 55%, 100%, 72%, 100%, and 58% by planar imaging and 81%, 100%, 88%, 100%, and 76% by SPECT, respectively. CONCLUSIONS: Because of the high specificity and reasonable sensitivity, Tc-99m PMT appears to be useful for the differential diagnosis of extrahepatic metastases from HCC. SPECT improves the detectability of small or faint accumulation in metastases from HCC.

Aged↗
PubMed2000

Ascorbic acid improves postischemic vasodilatation impaired by infusion of soybean oil into canine iliac artery.

This study was conducted to (a) assess postischemic vasodilatation by changes in the vascular cross-sectional area using simultaneous intravascular two-dimensional and Doppler ultrasound before and after the infusion of Intralipid (Pharmacia & Upjohn, Peapack, NJ, U.S.A.); (b) evaluate how antioxidant ascorbic acid modifies the effects of Intralipid on postischemic vasodilatation: and (c) clarify the changes in plasma nitrite and nitrate (NOx-) levels after the infusion of Intralipid with and without ascorbic acid. Twenty-eight mongrel dogs were used to measure for vascular cross-sectional area and average instantaneous peak velocity in the iliac arteries after the 5-min occlusion of the arteries. Postischemic vasodilatation was impaired after the infusion of Intralipid (20%, 2 ml/kg) and this impaired response was reversed by the co-administration of ascorbic acid (30 mg/kg). NG-monomethyl-L-arginine completely abolished postischemic vasodilatation. Plasma NOx levels were significantly reduced after the infusion of Intralipid compared with baseline (11.6+/-0.4 vs. 12.9+/-0.3 microM, p = 0.025) and after infusion of Intralipid with ascorbic acid compared with baseline (11.8+/-0.5 vs. 13.1+/-0.4 microM, p = 0.047). We concluded that ascorbic acid reverses the endothelial dysfunction induced by Intralipid without increasing plasma NOx- levels and that deactivation of nitric oxide by oxidative stress is a primary contributor to Intralipid-induced impaired vasodilation.

Animals↗
PubMed2000

Implication of NF-kappaB in Helicobacter pylori-associated gastritis.

OBJECTIVE: Transcription factor NF-kappaB plays a pivotal role in inflammatory responses by up-regulating mRNA expression of bioactive molecules such as chemokines and adhesion molecules. The present study was designed to elucidate the implication of NF-kappaB in Helicobacter pylori-associated gastritis (HAG). METHODS: We examined 41 patients with HAG and 18 H. pylori-negative control subjects. Expression of activated NF-kappaB was studied in situ by immunohistochemistry using alpha-p65 mouse monoclonal antibody (alpha-p65 mAb), which recognizes activated NF-kappaB. To identify the cell types in which NF-kappaB was activated, we performed immunohistochemical analysis using antibodies against vascular endothelial cells, macrophages, and B and T lymphocytes. We also examined the colocalization of activated NF-kappaB with the of intercellular expression adhesion molecule-1 (ICAM-1) on endothelial cells. We measured the levels of NF-kappaB-dependent chemokines including interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1), regulated on activation normal T-cell expressed and secreted (RANTES) and macrophage inflammatory protein-1alpha (MIP-1alpha) in antral mucosa by ELISA (ELISA). RESULTS: Activated NF-kappaB was detected in the nuclei of epithelial cells in antral mucosa, especially of patients with HAG. NF-kappaB positivity index (NF-kappaB PI), representing the percentages of epithelial cells with positive nuclear staining for activated NF-kappaB, was significantly higher in patients with HAG than in H. pylori-negative controls. NF-kappaB PI correlated significantly with histological scores of gastritis. Moreover, activated NF-kappaB was identified in the nuclei of vascular endothelial cells, macrophages, and B lymphocytes within the lamina propria in HAG. Colocalization of activated NF-kappaB with ICAM-1 expression in the same endothelial cells was demonstrated. The IL-8 levels significantly correlated with the NF-kappaB PI. CONCLUSIONS: In addition to epithelial cells, macrophages, vascular endothelial cells, and B lymphocytes contained activated NF-kappaB. In these cells, activated NF-kappaB may be involved in the inflammation process in HAG through the up-regulation of chemokines or adhesion molecules.

Adult↗
PubMed2000

Robust changes of afferent-induced excitation in the rat spinal dorsal horn after conditioning high-frequency stimulation.

We investigated the neuronal plasticity in the spinal dorsal horn and its relationship with spinal inhibitory networks using an optical-imaging method that detects neuronal excitation. High-intensity single-pulse stimulation of the dorsal root activating both A and C fibers evoked an optical response in the lamina II (the substantia gelatinosa) of the dorsal horn in transverse slices of 12- to 25-day-old rat spinal cords stained with a voltage-sensitive dye, RH-482. The optical response, reflecting the net neuronal excitation along the slice-depth, was depressed by 28% for more than 1 h after a high-frequency conditioning stimulation of A fibers in the dorsal root (3 tetani of 100 Hz for 1 s with an interval of 10 s). The depression was not induced in a perfusion solution containing an NMDA antagonist, DL-2-amino-5-phosphonovaleric acid (AP5; 30 microM). In a solution containing the inhibitory amino acid antagonists bicuculline (1 microM) and strychnine (3 microM), and also in a low Cl(-) solution, the excitation evoked by the single-pulse stimulation was enhanced after the high-frequency stimulation by 31 and 18%, respectively. The enhanced response after conditioning was depotentiated by a low-frequency stimulation of A fibers (0.2-1 Hz for 10 min). Furthermore, once the low-frequency stimulation was applied, the high-frequency conditioning could not potentiate the excitation. Inhibitory transmissions thus regulate the mode of synaptic plasticity in the lamina II most likely at afferent terminals. The high-frequency conditioning elicits a long-term depression (LTD) of synaptic efficacy under a greater activity of inhibitory amino acids, but it results in a long-term potentiation (LTP) when inhibition is reduced. The low-frequency preconditioning inhibits the potentiation induction and maintenance by the high-frequency conditioning. These mechanisms might underlie robust changes of nociception, such as hypersensitivity after injury or inflammation and pain relief after electrical or cutaneous stimulation.

2-Amino-5-phosphonovalerate↗
PubMed2000

Effect of intrarectal prostaglandin E2 analogue (enprostil) on trinitrobenzenesulphonic acid-induced colitis in rats.

Prostaglandins exert a protective effect on colonic mucosa in experimentally induced colitis. This study investigated the effect of enprostil, a prostaglandin E2 (PGE2) analogue, on trinitrobenzenesulphonic acid (TNBS)-induced colitis in rats. Each rat received a rectal enema containing TNBS (30 mg), followed 24 h later by intrarectal once-daily enprostil (200 microg). Enprostil-treated and control rats were killed on day 3 (enprostil group, n = 5; control, n = 6) or day 10 (enprostil group, n = 5; control, n = 5) after TNBS treatment. The area of damaged mucosa of the colon was measured relative to the total colonic area. We also determined the macroscopic score of mucosal damage, and measured PGE2, 6-keto-prostaglandin F1alpha (6-keto-PGF1alpha) and thromboxane B2 (TXB2) concentration in portal vein blood samples. Enprostil significantly reduced both the area of damaged mucosa (including the ulcer area) and the macroscopic score after 3 days' treatment compared with control. Similarly, enprostil significantly reduced plasma concentration of PGE2, 6-keto-PGF1alpha and TXB2 during the acute phase at day 3 of treatment compared with control, but not at day 10. These results suggest that PGE2 enema may have therapeutic potential for treating patients with proctitis or left-sided colitis.

Animals↗
PubMed2000

Structure-affinity relationships of C-terminal cyclic analogue of neuropeptide Y for the Y1-receptor.

We previously reported that a cyclic octapeptide amide, c[D-Cys29, Cys-34]NPY Ac-29-36 (YM-42454) showed a high affinity for Y1-receptors in SK-N-MC cells (Ki=0.047,microM) but not for Y2-receptors in the porcine hippocampus membranes (Ki>10microM). To explore the critical residues of this unique cyclic peptide for Y1-binding activity, the structure-affinity relationships were investigated by means of amino acid replacement. The results indicated that the hydrophobic side-chains of Leu30 and Ile31, the guanidinium groups of Arg33 and Arg33, and the C-terminal amide are critical for the binding affinity of YM-42454 to the Y1-receptor. On the other hand, Thr32 in YM-42454 might not be critical for the Y1-binding affinity. 1H-NMR studies for YM-42454 and its derivatives have suggested that the critical residues are involved in the direct interaction with a Y1-receptor rather than in maintaining the bioactive conformation.

Animals↗
PubMed2000

Simultaneous intravascular two-dimensional plus Doppler ultrasound is useful for evaluation of postischemic vasodilatation: plasm NOx - levels determined by the Griess method may not reflect the extent of postischemic NO-induced vasodilatation.

Our objective was 1) to assess postischemic vasodilatation using simultaneous intravascular two-dimensional and Doppler ultrasound, and 2) to clarify whether plasma nitrite and nitrate (NOx-) levels change during postischemic vasodilatation. The vascular cross-sectional area (CSA) was evaluated in 18 mongrel dogs, and the average instantaneous peak velocity (APV) in the iliac arteries after the 5-min occlusion of blood flow was determined. Plasma NOx- levels were measured at the baseline, during the occlusion of blood flow, and 1.5, 3, and 10 min after recanalization. The %CSA significantly increased from 30 s to 7 min after the recanalization, and maximal vasodilatation was observed at 1.5 min after the recanalization (14.1 +/- 0.9 to 15.8 +/- 1.0 mm2, p< 0.0001 vs. baseline). Plasma NOx- levels were significantly reduced during the occlusion of blood flow and remained reduced at 1.5, 3, and 10 min after recanalization compared with the baseline values. We concluded that simultaneous intravascular two-dimensional and Doppler ultrasound is useful for assessment during postischemic vasodilatation, and that plasma NOx- levels assayed with the Griess reagent do not significantly increase, even when maximal vasodilatation is observed.

Animals↗
PubMed2000

Monoclonal antibody against bovine alpha1-acid glycoprotein.

Monoclonal antibodies (Mabs) against bovine alpha1-acid glycoprotein (alpha1AGP) were prepared from mouse hybridoma cell line. Bovine alpha1AGP as antigen was purified by using ion exchange column chromatography and the yield from 500 ml serum was about 10 mg. Immunoglobulin isotypes of 3 Mabs obtained were IgM and light chain types were kappa. The Mabs reacted with bovine alpha1AGP on immunoblot analysis, but not with alpha1AGP digested with N-glycosidase, suggesting that an epitope recognized by these Mabs may be associated with a glycan side chain of bovine alpha1AGP.

Amidohydrolases↗
PubMed2000

Diffuse noxious inhibitory controls in anti-nociception produced by acupuncture and moxibustion on trigeminal caudalis neurons in rats.

Numerous studies have demonstrated that acupuncture and moxibustion induce analgesic effects. This study examined whether diffuse noxious inhibitory controls (DNIC) participated in acupuncture and moxibustion induced-analgesia. Single unit extracellular recordings from neurons in the trigeminal nucleus caudalis of urethane-anesthetized Wistar rats were obtained with a glass micropipette. A total of 52 single units, including 36 wide dynamic range (WDR), 5 nociceptive specific (NS) and 11 low-threshold mechanoreceptive (LTM) units were examined. During noxious test stimulation (cutaneous pinch or electrical stimulation), acupuncture, moxibustion or pinch stimulation was applied as the conditioning stimulus to the remote area of the receptive fields. When the conditioning stimulation induced rapid suppression of noxious receptive field stimulation response, examination revealed that various areas of the entire body were affected and suppression increased in an intensity-dependent manner. These features resemble DNIC phenomena. The suppression was observed on both WDR and NS neurons but not on LTM neurons. Eight of 16 WDR neurons examined were inhibited by acupuncture, five of 14 by moxibustion, and seventeen of 21 by pinching stimulation. Of the NS neurons, one of 2 units examined was suppressed by acupuncture, one of 2 by moxibustion, and two of 3 by pinch stimulation. Pinch stimulation induced the most profound suppression followed by manual acupuncture. Moxibustion induced moderate suppression with a long induction time. These results suggest that DNIC may be involved in the analgesic mechanism of acupuncture and moxibustion.

Acupuncture Analgesia↗
PubMed2000

Two- and three-dimensional CT ventriculography: a new application of helical CT.

OBJECTIVE: We propose a new application of helical CT, CT ventriculography, which can produce two-dimensional (2D) and three-dimensional (3D) images of different cardiac phases (plus animation). We sought to determine the accuracy of CT ventriculography for assessing left ventricular volumes. MATERIALS AND METHODS: With a single breath-hold, the patient's entire heart was scanned with an ECG-gating technique (3-mm-thick collimation, 2 mm per rotation table speed, 0.8 sec per rotation, and 50 rotations through 10 cm in total). Using a 0.2-mm (0.08-sec) interval (10 slices per rotation) overlapping reconstruction, about 500 axial slices were obtained and reordered to separate different cardiac cycles. Then, 2D cardiac axes and 3D images were reconstructed and animated movies of the 2D and 3D images were produced. In 21 patients, the left ventricular end-diastolic volume, end-systolic volume, and ejection fraction were assessed and compared with left ventriculography. Correlations and agreements between CT and left ventriculography were determined. RESULTS: Close correlations between CT and left ventriculography were obtained (r = 0.95, 0.98, and 0.91, for end-diastolic volume, end-systolic volume, and left ventricular ejection fraction, respectively; p < 0.0001 for all values). The limits of agreement between CT and left ventriculography were 44.3 to -44.5 ml for end-diastolic volume, 19.8 to -29.0 ml for end-systolic volume, and 19.7% to -9.5% for left ventricular ejection fraction. CONCLUSION: This cardiac application of helical CT provides a clear morphology along the cardiac axes and 3D images and an assessment of left ventricular volumes (end-diastolic volume, end-systolic volume, and left ventricular ejection fraction).

Adult↗
PubMed2000

[Mechanisms of thiazolidinedione derivatives for hypoglycemic and insulin sensitizing effects].

Ciglitazone was the first insulin sensitizer with a thiazolidinedione structure to reduce insulin resistance and hyperglycemia and many thiazolidinedione derivatives (TZDs) have since been reported as insulin sensitizers. Pioglitazone is reported to lower blood glucose through reductions in both hepatic and peripheral insulin resistance. Regarding the molecular mechanism, pioglitazone was first reported to increase the tyrosine kinase activity of the insulin receptor and then TZDs were reported to increase the insulin signal transduction. TNF-alpha causes insulin resistance through inhibition of the insulin signal transduction and TZDs have been shown to reduce insulin resistance by the suppression of the TNF-alpha gene expression. In addition, TZDs are specific agonists of PPAR gamma and the hypoglycemic effect of TZDs has been shown to involve PPAR gamma among the PPARs. Based on these observations, the molecular mechanisms of TZDs are discussed.

Animals↗
PubMed2000

Quantitative analysis of technegas SPECT: evaluation of regional severity of emphysema.

UNLABELLED: The purpose of this study was to quantify the regional severity of emphysema by 3-dimensional fractal analysis of technegas (99mTc-carbon particle radioaerosol) SPECT images. METHODS: Technegas SPECT was performed on 22 patients with emphysema. The lungs were delineated using 4 cutoff levels (15%, 20%, 25%, and 30% of the maximal pixel radioactivity), and the total number of pixels was measured in the areas surrounded by the contours obtained with each cutoff level. We calculated fractal dimensions from the relationship between the total number of pixels and cutoff levels transformed into logarithms. Fractal dimension for total or regional lung was defined as the severity of emphysema. RESULTS: Total lung fractal dimension (T-FD), upper lung fractal dimension (U-FD), and lower lung fractal dimension (L-FD) for patients with emphysema were 1.84 +/- 0.46 (mean +/-SD), 2.22 +/- 0.61, and 1.77 +/- 0.49, respectively. U-FD was significantly greater than was L-FD. Patients with the ratio of U-FD to L-FD of <1.16 had a significantly greater percentage forced vital capacity (FVC) than did patients with the ratio of >1.16. Patients with an L-FD of <1.8 had a significantly greater forced expiratory volume in 1 s (FEV1)/FVC than did patients with that of >1.8. No significant difference was found between patient groups stratified by U-FD. CONCLUSION: The regional severity of emphysema was well shown by these fractal dimensions.

Female↗
PubMed1999

Adult T-cell leukemia cells over-express the multidrug-resistance-protein (MRP) and lung-resistance-protein (LRP) genes.

Adult T-cell leukemia (ATL) is a T-cell malignancy caused by human T-cell-leukemia-virus-I (HTLV-I) infection. ATL comprises 4 clinical forms: acute, chronic, smoldering and lymphoma types. ATL is usually resistant to conventional chemotherapy and has a relatively poor prognosis; however, the resistance mechanisms remain undetermined. To explore the multidrug-resistance (MDR) mechanisms of ATL, we examined the expression and functional activity of MDR-related genes in peripheral-blood mononuclear cells (PBMC) from ATL patients by semi-quantitative RT-PCR and FACScan with calcein-AM. PBMC from ATL patients expressed similar or higher levels of MRP, LRP and cMOAT mRNAs, as compared with normal PBMC. In normal controls and ATL patients, MDR1 mRNA expression was undetectable in this study. PBMC from acute and chronic ATL patients expressed significantly higher levels of MRP and LRP mRNA than did normal PBMC (p < 0.01 and p < 0.05 respectively). In chronic ATL, positive correlations were apparent between levels of MRP and LRP mRNA expression (r = 0.759, p = 0.018), and between each mRNA level and the absolute number of abnormal lymphocytes in peripheral blood. Probenecid, an inhibitor of the MRP pump, significantly increased the accumulation of calcein in PBMC from 3 chronic ATL patients. Our findings suggest that the MRP and LRP genes in ATL are often activated by HTLV-I infection and may confer MDR of ATL cells in vivo. Combined chemotherapy with inhibitors of these MDR genes may be promising in the treatment of ATL.

ATP Binding Cassette Transporter, Subfamily B, Mem↗