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A Murakami

Publications and source records attributed to A Murakami.

At least 181 records · Page 10Linked to original sources
PubMed1997

Mechanisms producing color change in flat early gastric cancers.

BACKGROUND AND STUDY AIMS: Although highly refined endoscopes have made it possible to detect not only early gastric cancers with morphological changes, but also flat-type tumors (type IIb) on the basis of the color changes observed in them, the factors responsible for color changes in type IIb carcinomas have not been fully elucidated. The aim of this study was to analyze the potential mechanisms underlying these color changes. PATIENTS AND METHODS: Thirteen type IIb cancers were selected from a total of 589 resected gastric cancers detected preoperatively using endoscopic examination. All of the tumors showed color changes alone, without surface changes, and the color changes included redness, discoloration, and spotty bleeding. Detailed histological examination of the resected stomachs revealed twelve more II b lesions that had not been identified at endoscopy. The endoscopic appearance of the IIb cancers were correlated with the degree of tumor differentiation, the extent of wall infiltration, and the number of capillaries. RESULTS: In cases that were detectable by endoscopy, the endoscopic color appearance correlated significantly with both tumor size (P < 0.02) and with the extent of mucosal cancer infiltration (P < 0.02). Histological examination of the IIb lesions revealed that redness and discoloration were significantly more frequent in the differentiated and undifferentiated cancer types, respectively (P < 0.01). There was a significant difference in the number of capillaries between type IIb carcinoma and the adjacent normal mucosa, but not between cancers. The numbers for differences in redness and discoloration were 7.0 +/- 5.6 and -14.0 +/- 8.8, respectively. CONCLUSIONS: These results suggest that the main factor underlying color change in type IIb early gastric cancers may be the number of capillaries in the lesions, in comparison with the adjacent mucosa. Whether the lesion is visible on endoscopy, however, depends more on its size than on the number of capillaries.

Adult↗
PubMed1997

Citrus auraptene inhibits chemically induced colonic aberrant crypt foci in male F344 rats.

The modifying effect of dietary administration of auraptene isolated from the peel of citrus fruit (Citrus natsudaidai Hayata) on the development of azoxymethane (AOM)-induced colonic aberrant crypt foci (ACF) was investigated in rats. Male F344 rats were given s.c. injections of AOM (15 mg/kg body wt) once a week for 3 weeks to induce ACF. They also received diets containing 100 or 500 p.p.m. auraptene for 5 weeks, starting 1 week before the first dose of AOM. At termination of the study (week 5) dietary administration of auraptene caused a significant reduction in the frequency of ACF in a dose-dependent manner (P < 0.05). Feeding of auraptene suppressed expression of cell proliferation biomarkers (5-bromo-2'-deoxyuridine labeling-index, ornithine decarboxylase activity, polyamine content and number of silver stained nucleolar organizer region protein particles) in the colonic mucosa and the occurrence of micronuclei caused by AOM. Also, auraptene increased the activities of phase II enzymes (glutathione S-transferase and quinone reductase) in the liver and colon. These findings might suggest that inhibition of AOM-induced ACF may be associated, in part, with increased activity of phase II enzymes in the liver and colon and suppression of cell proliferation in the colonic mucosa.

Animals↗
PubMed1997

A xanthine oxidase inhibitor 1'-acetoxychavicol acetate inhibits azoxymethane-induced colonic aberrant crypt foci in rats.

The modifying effect of dietary administration of a xanthine oxidase inhibitor 1'-acetoxychavicol acetate (ACA) present in an edible plant Languas galanga in Thailand on the development of azoxymethane (AOM)-induced colonic aberrant crypt foci (ACF) was investigated in rats. Male F344 rats were given s.c. injections of AOM (15 mg/kg body wt) once a week for 3 weeks to induce colonic ACF. They were fed the diets containing 100 or 200 ppm ACA for 5 weeks, starting 1 week before the first dosing of AOM. At the termination of the study (week 5), AOM induced 118 +/- 28 ACF/colon. Dietary administration of ACA caused significant reduction in the frequency of ACF (41% inhibition by 100 ppm ACA feeding and 37% inhibition by 200 ppm ACA feeding, P<0.01). Such inhibition might be associated with suppression of the proliferation biomarkers' expression such as ornithine decarboxylase activity in the colonic mucosa, number of silver-stained nucleolar organizer regions' protein in the colonic mucosal cell nuclei and blood polyamine content. These results indicate that ACA could inhibit the development of AOM-induced ACF through its suppression of cell proliferation in the colonic mucosa and ACA might be a possible chemopreventive agent against colon tumourigenesis.

Animals↗
PubMed1997

Changes in photosystem stoichiometry in response to environmental conditions for cell growth observed with the cyanophyte Synechocystis PCC 6714.

Changes in photosystem stoichiometry in response to shift of environments for cell growth other than light regime were studied with the cyanophyte Synechocystis PCC 6714 in relation to the change induced by light-quality shift. Following two environment-shifts were examined: the shift of molecular form of inorganic carbon source for photosynthesis from CO2 to HCO3- (CO2 stress) and the increase in salinity of the medium with NaCl (0.5 M) (Na+ stress). Both CO2 and Na+ stresses induced the increase in PSI abundance resulting in a higher PSI/PSII stoichiometry. CO2 stress was found to elevate simultaneously Cyt c oxidase activity (Vmax). The feature was the same as that caused by light-quality shift from preferential excitation of PSI to PSII (light stress) though the enhancement by either stress was smaller than that by light stress. Under our experimental conditions, PSI/PSII stoichiometry appeared to increase at a fairly constant rate to the basal level even when the basal level had been differently determined by the light-quality. Enhancing rates for PSI/PSII stoichiometry and for Cyt c oxidase activity were also similar to each other. Since the two stresses affect the thylakoid electron transport similarly to the shift of light-quality, we interpreted our results as follows: three environmental stresses, CO2, Na+, and light stresses, cause changes in electron turnover capacity of PSI and Cyt c oxidase under a similar, probably a common, mechanism for monitoring redox state of thylakoid electron transport system.

Carbon Dioxide↗
PubMed1997

Auraptene, a citrus coumarin, inhibits 12-O-tetradecanoylphorbol-13-acetate-induced tumor promotion in ICR mouse skin, possibly through suppression of superoxide generation in leukocytes.

Coumarin-related compounds, auraptene and umbelliferone, have been isolated from the cold-pressed oil of natsumikan (Citrus natsudaidai HAYATA), and tested as inhibitors of tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced Epstein-Barr virus activation in Raji cells. The 50% inhibitory concentration (IC50) of auraptene (18 microM) was almost equal to that of genistein. Umbelliferone, which lacks a geranyloxyl group present in auraptene, was less active (IC50 = 450 microM). In a two-stage carcinogenesis experiment with 7,12-dimethylbenz[a] anthracene (topical application at 0.19 mumol) and TPA (topical application at 1.6 nmol) in ICR mouse skin, topical application of auraptene (at 160 nmol) significantly reduced tumor incidence and the numbers of tumors per mouse by 27% (P < 0.01) and 23% (P < 0.05), respectively. Auraptene at a concentration of 50 microM markedly suppressed superoxide (O2-) generation induced by 100 microM TPA in differentiated human promyelocytic HL-60 cells. Having no O2(-)-scavenging potential, auraptene may inhibit the multicomponent NADPH oxidase system. Inhibition of intracellular hydroperoxide formation in differentiated HL-60 cells by auraptene was also confirmed by flow-cytometric analysis using 2',7'-dichlorofluorescein diacetate as a fluorescence probe. Quantitative analyses using high-performance liquid chromatography showed the occurrence of auraptene not only in both the peels and sarcocarps of natsumikan, but also in those of hassaku orange (C. hassaku) and grapefruit (C. paradisi), and even in their bottled fresh juice form. These results indicate that auraptene is a chemopreventer of skin tumorigenesis, and implies that suppression of leukocyte activation might be the mechanism through which it inhibits tumor promotion.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1997

Chemoprevention of azoxymethane-induced rat colon carcinogenesis by a xanthine oxidase inhibitor, 1'-acetoxychavicol acetate.

In our studies to find natural compounds with chemopreventive efficacy in foods, using azoxymethane (AOM)-induced colonic aberrant crypt foci and colonic mucosal cell proliferation as biomarkers, a xanthine oxidase inhibitor, 1'-acetoxychavicol acetate (ACA), present in the edible plant Languas galanga from Thailand was found to be effective. This study was conducted to test the ability of ACA to inhibit AOM-induced colon tumorigenesis when it was fed to rats during the initiation or post-initiation phase. Male F344 rats were given three weekly s.c. injections of AOM (15 mg/kg body weight) to induce colonic neoplasms. They were fed diet containing 100 or 500 ppm ACA for 4 weeks, starting one week before the first dosing of AOM (the initiation feeding). The other groups were fed the ACA diet for 34 weeks, starting one week after the last AOM injection (the post-initiation feeding). At the termination of the study (week 38), AOM had induced 71% incidence of colonic adenocarcinoma (12/17 rats). The initiation feeding with ACA caused significant reduction in the incidence of colon carcinoma (54% inhibition by 100 ppm ACA feeding and 77% inhibition by 500 ppm ACA feeding, P = 0.03 and P = 0.001, respectively). The post-initiation feeding with ACA also suppressed the incidence of colonic carcinoma (45% inhibition by 100 ppm ACA feeding and 93% inhibition by 500 ppm ACA feeding, P = 0.06 and P = 0.00003, respectively). Such inhibition was dose-dependent and was associated with suppression of proliferation biomarkers, such as ornithine decarboxylase activity in the colonic mucosa, and blood and colonic mucosal polyamine contents. ACA also elevated the activities of phase II enzymes, glutathione S-transferase (GST) and quinone reductase (QR), in the liver and colon. These results indicate that ACA could inhibit the development of AOM-induced colon tumorigenesis through its suppression of cell proliferation in the colonic mucosa and its induction of GST and QR. The results confirm our previous finding that ACA feeding effectively suppressed the development of colonic aberrant crypt foci. These findings suggest possible chemopreventive ability of ACA against colon tumorigenesis.

Animal Feed↗
PubMed1997

Effects of MRI abnormalities on WAIS-R performance in solvent abusers.

OBJECTIVE: To clarify how chronic solvent abuse affects cognitive function using magnetic resonance imaging as an index of brain damage. MATERIAL AND METHODS: A total of 25 chronic solvent abusers underwent magnetic resonance imaging with quantitative neurometry and Wechsler Adult Intelligence Scales revised. RESULTS: The abusers with white matter change (n=10) showed significantly (P<0.05) lower performance IQ, especially in Digit Symbol subtest (P<0.01). Also, the severity of pontine atrophy was significantly correlated with PIQ (r=0.60, P<0.01). CONCLUSIONS: These data indicate that solvent abuse causes the decline in the test performance reflecting cognitive and fine motor dysfunction and that white matter changes and pontine atrophy may have some roles in this decline.

Adult↗
PubMed1997

Effect of sublethal X-irradiation on follicular trapping of immune complexes in the mouse lymph node.

In one set of experiments, the effect of sublethal X-irradiation on the 24 h localization of subcutaneously injected immune complexes in the lymph node follicles was studied in mice which were given HRP-anti-HRP complexes into the rear footpad at 1-3 weeks after irradiation and killed 1 day later. The 24 h follicular localization of injected immune complexes in draining popliteal nodes was severely impaired at 7 days after irradiation, at which time residual follicles were markedly depleted of B lymphocytes. In following weeks, residual follicles began to be repopulated, and the 24 h follicular localization of immune complexes became restored. Follicular dendritic cells (FDC), as was detected by the in vitro trapping assay and/or by the immunostaining for complement receptors CR1, were present in lymph nodes at any time after irradiation. Another group of mice were given HRP-anti-HRP complexes at 6 days of X-irradiation and killed from 15 min to 24 h later. Following the injection, complexes localized in residual follicles in draining nodes within 15 min but soon diminished in density and finally disappeared by 24 h after injection. It is obvious that sublethal irradiation affect neither transport of immune complexes to lymph node follicles nor their localization in these follicles. Rather rapid disappearance after temporal localization of immune complexes in residual follicles irradiated mice indicates that persisting FDC were unable effectively to trap immune complexes which were transported and localized in residual follicles. Ineffective trapping by FDC of immune complexes temporally localized in residual follicles is discussed in relation to the depletion of follicular B lymphocytes due to X-irradiation.

Animals↗
PubMed1997

The inhibitory effect of vitamin E on arachidonic acid metabolism during the process of urethane-induced lung tumorigenesis in mice.

It is known that change in the arachidonic acid metabolism plays an important role in the development of tumors. This study was undertaken to understand the relationship of changes in lipoxygenase, cyclooxygenase and ornithine decarboxylase (ODC) to the inhibitory effect of vitamin E on urethane-induced lung tumorigenesis in mice. We analyzed the inhibitory effect of vitamin E on ornithine decarboxylase, cyclooxygenase and lipoxygenase activities at a promotion phase of lung tumorigenesis in mice. An increase in the ODC of urethane treated-mice and no significant change in the ODC of VE-treated mice were observed. An increase in the production of PGE2 and all HETES tested in the lungs of the urethane-treated mice was observed at week 8 after injection (promotion phase), showing a significant difference compared to the control group. Excessive vitamin E feeding during the initiation or promotion phases inhibited the increase in PGE2 and HETES produced by urethane treatment. These results suggest that the suppression of prostagrandin metabolism and ODC may be associated with the inhibitory effect of vitamin E against urethane-induced lung tumorigenesis.

Animals↗
PubMed1997

Evaluation of the human gene encoding recoverin in patients with retinitis pigmentosa or an allied disease.

PURPOSE: To determine whether defects in the human recoverin gene cause retinitis pigmentosa (RP) or an allied disease such as Usher syndrome, Leber congenital amaurosis, or the Bardet-Biedl syndrome. METHODS: Single-strand conformation polymorphism analysis and direct genomic sequencing techniques were used to screen 596 unrelated patients, comprising 167 patients with dominant RP, 168 with recessive RP, and 261 with an allied disease. RESULTS: Four sequence variants were discovered. The first was a missense change (Ala200Thr) found in one family with autosomal dominant RP and in one family with autosomal recessive RP; it did not segregate with disease. The second was a silent, single-base variation affecting codon Ser24 with a minor allele frequency of approximately 0.5%. The third was a silent, single-base variation affecting codon Va1122. The fourth was a single-nucleotide substitution in intron 2, 11 bp upstream of exon 3. CONCLUSIONS: The authors found no evidence that mutations in the recoverin gene are a cause of RP or another of the hereditary retinal diseases studied. The human phenotype associated with mutations of the recoverin gene remains unknown.

Calcium-Binding Proteins↗
PubMed1997

[A case of primary orbital chondrosarcoma].

The case of a twenty-year-old male with orbital chondrosarcoma is reported. He visited National Defense Medical College Hospital because of reduced vision in the right eye since two months previously. His corrected visual acuity was 8/20 in the right eye and 20/20 in the left eye. Fifteen degrees lateral displacement of the right globe and limitation of right ocular movement were recognized. Right fundus examination revealed optic disc edema and protuberant nasal fundus. Orbital computed tomography (CT) demonstrated a high density area between the inner part of the right orbit and the ethmoid sinus. Magnetic resonance imaging (MRI) showed a smoothly outlined and low intensity (T1) space occupying lesion. This lesion was irregularly enhanced by gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA). This orbital tumor was removed by an anterior approach. Histopathological examination revealed well-differentiated chondrosarcoma (grade 1) as determined by small prominent chondromatous cell projection into the collagen fibrous stroma, and existence of binucleate cells in the hypercellular region. After the operation the disc edema disappeared and his corrected right visual acuity improved to 20/20.

Adult↗
PubMed1997

Acute effect of oral prostacyclin and inhaled nitric oxide on pulmonary hypertension in children.

The hemodynamic effects of acute oral administration of a newly-developed prostacyclin analogue (beraprost sodium; 1-2 micrograms/kg), inhaled nitric oxide (NO; 20 ppm) and tolazoline hydrochloride (1 mg/kg) were measured in 17 children (mean age 1 year and 9 months) with pulmonary hypertension complicating congenital heart disease or primary pulmonary hypertension. Beraprost, NO and tolazoline achieved approximately equivalent reductions in pulmonary vascular resistance (20%, 26% and 18%, p < 0.05), but the greatest percentage decrease of pulmonary to systemic resistance ratio was obtained after administration of NO (33%, p < 0.05). Furthermore, combined administration of beraprost and NO produced the maximum effect of pulmonary vasodilation without adverse effects (49%). Beraprost appears to be an effective and available substitute for NO and tolazoline in screening for pulmonary vasodilator responsiveness. The combined use of beraprost and NO may provide an alternative treatment for pulmonary hypertension in children without serious complications.

Administration, Inhalation↗
PubMed1997

[A case of ventricular septal perforation treated surgically with an infarction exclusion technique].

We report an 85-year-old woman with postinfarction interventricular septal perforation. She underwent successful emergent surgical treatment by a slightly modified method based on David-Komeda's procedure. Perforation in this case occurred four days after acute myocardial infarction. Preoperative Qp/Qs was 2.58, and pulmonary artery pressure was 34/25 mmHg. The area of infarction was large, and the perforation was the linear type 2.5 cm long near the apex. A probe was not able to pass through the perforation due to its complicated configuration. A double Xenomedica patch was sutured on the left side of the interventricular septum without excising the infarcted area. The suture line was placed on healthy myocardium apart from the infarcted area. The Xenomedica patch was sandwiched between the closure line of the ventriculotomy. Four days after surgery, residual shunt was observed by echocardiogram, but this subsequently disappeared on the 17th postoperative day. The patient was discharged from our hospital on the 57th postoperative day, and is now doing quite well.

Aged↗
PubMed1997

[A case of dermatomyositis with severe retinopathy in a patient who died of acute interstitial pneumonia].

Sight threatening ocular complications are rare in adult patients with dermatomyositis. We encountered a 52-year-old female with dermatomyositis who had severe visual disturbance and rapidly progressive intersitial pneumonia. She was admitted to our hospital because of skin erythema, general fatigue, mild fever, and severe bilateral visual disturbance. Rentinal hemorrhages, cotton wool spots, and macular edema were observed in her fundus at the first ophthalmic examination. A diagnosis of dermatomyositis was made because of the myogenic pattern of her electromyogram, elevation of serum creatine kinase, and skin lesions. Oral prednisolone treatment was started and the retinopathy was improved, but was complicated by acute interstitial pneumonia. The interstitial pneumonia was not respond to steroid pulse therapy with methylprednisolone, and the patient died of respiratory failure on the 47th day after the onset of visual symptoms. In adult dermatomyositis patients, the complication of severe retinopathy should be considered as a risk factor for rapid progress of interstitial pneumonia.

Acute Disease↗
PubMed1997

[Pterygium and mast cells--mast cell number, phenotype, and localization of stem cell factor].

We examined the number and phenotype of mast cells, and the localization of stem cell factor (SCF) as a growth factor of mast cells in the excised tissue of 38 cases of pterygium. In histopathology with toluidine blue stain and immunohistochemistry with a monoclonal antibody to tryptase, the mean mast cell count in pterygium specimens was twice as high as in normal conjunctiva. In pterygium specimens more than 94% of tryptase-positive mast cells were found to express chymase and c-kit. There was no phenotypic difference between mast cells in pterygium and normal conjunctiva. In all immunohistochemical specimens in which we could examine the head of the pterygium, SCF was expressed in subepithelial fibroblasts at the central edge of pterygium. The results suggest that overexpression of SCF was accompanied with the augmentation of mast cells in the pterygium.

Cell Count↗
PubMed1997

[A surgical case of aorto-pulmonary septal defect in a low weight neonate].

We report a surgical case of aorto-pulmonary septal defect (APSD) in a neonate weighing 1693 gm. A male twin baby delivered after 39 weeks and 5 days of gestational period was diagnosed as APSD. RAA, PFO and PLSVC by a echocardiography and a MRI. Because of the progressive cardiac failure, operation was performed under cardiopulmonary bypass and profound hypothermic circulatory arrest at 30 days of age and weighing 1693 gm. APSD was closed completely by a Dacron patch. Postoperative course was almost uneventful except for pulmonary hypertension crisis. He recovered without brain damage.

Aorta↗
PubMed1997

[Changes in neutrophil counts and lymphocytes subpopulations of a ECLS instituted patient].

A 4-year-old girl with tetoralogy of Fallot developed acute heart failure after ASD semiclosure. As drugs had no effect, ECLS was instituted. She gradually recovered from acute heart failure. ECLS was detached at 5 days after institution. Neutrocytopenia and lymphocytopenia became apparent during ECLS institution. The Subpopulations of T cell and NK cell decreased, and B cell subpopulation increased on the contrary during ECLS institution. This lymphocytopenia was caused by a decrease in T cell, especially CD4(+) cell numbers. It is necessary to minimize the potential for infection during ELCS institution.

Child, Preschool↗