Biomedical subjects

M Itoh

Publications and source records attributed to M Itoh.

At least 361 records · Page 20Linked to original sources

PubMed1998

Relations between surface expression of the interleukin-2 receptor and release of the soluble form of the receptor in cultured mononuclear cells from patients with rheumatoid arthritis or systemic lupus erythematosus.

The relationship between surface expression of the interleukin-2 receptor (IL-2R) and release of the soluble form of the receptor (sIL-2Ralpha or sCD25) was investigated with peripheral blood mononuclear cells (PBMCs) from individuals with rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE). The spontaneous release of sCD25 was significantly increased in PBMCs from RA patients and decreased in cells from SLE patients, compared with normal controls. However, the extent of sCD25 release from phytohaemagglutinin (PHA)-stimulated PBMCs did not differ between RA or SLE patients and normal controls. The serum concentration of sCD25 was significantly increased in SLE or RA patients compared with the normal controls. Whereas the surface expression of CD25 by unstimulated PBMCs did not differ among the three groups of subjects, this parameter was significantly reduced for PHA-stimulated PBMCs from RA patients relative to those from normal controls. The surface expression of CD25 showed a positive correlation with sCD25 release for PBMCs from SLE patients under either basal or stimulated conditions. No such relation was apparent for cells from RA patients. The surface expression of IL-2Rbeta (CD 122) under basal or stimulated conditions was significantly reduced in PBMCs from RA or SLE patients, compared with cells from normal controls. Thus, the increased concentration of sCD25 in the serum of individuals with these autoimmune rheumatic diseases may result from two different mechanisms: an increase in the spontaneous release of sCD25 in RA, and reduced clearance of this protein in SLE.

Adult↗

PubMed1998

Development of a new method for simultaneously evaluating mucociliary clearance and pulmonary epithelial permeability in rabbit experiments by means of 18FDG, three-dimensional positron emission tomography and rectilinear scan.

We tried to simultaneously obtain the elimination constant of mucociliary clearance and the pulmonary epithelial permeability constant after inhalation of 2-[18F]fluoro-2-deoxy-D-glucose (18FDG) solution by carrying out whole lung positron emission tomography and a rectilinear scan in rabbit experiments. The elimination constant of pulmonary epithelial permeability was obtained from the decrease in the amount of the radioactivity with time in the region of interest (ROI) confined to the lungs, trachea and tracheal cannula in the rectilinear scan. The total elimination constant of the radioactivity in the lungs was obtained from the ROI confined to the lungs in the tomography. The mucociliary clearance rate constant in the lungs was then obtained after subtracting the elimination constant of the pulmonary epithelial permeability from the total elimination constant of the 18FDG in the lungs. The mucociliary clearance constant in the trachea was calculated from the residual radioactivity in the trachea and the mucociliary clearance constant in the lungs. The mean pulmonary epithelial permeability constant was 0.0020% min(-1) obtained from the rectilinear scan. The mean mucociliary clearance constants of the lungs and the trachea were 0.0006 and 0.025% min(-1), respectively. These results indicated that the pulmonary epithelial permeability and mucociliary clearance could be evaluated simultaneously with 18FDG by using three-dimensional positron emission tomography and a rectilinear scan.

Administration, Inhalation↗

PubMed1998

[Aneurysm of the nonpatent ductus arteriosus in the adult--a report of the case and review of the literature].

Aneurysm of the ductus arterious in adult in rare. 28 cases have been previously reported in the Japanese literature. A new 73-year-old male case, preoperatively diagnosed and successfully repaired, are presented. The patient with hoarseness was admitted to our hospital. Contrast-enhanced CT scans and aortograms made a diagnosis for the aneurysm of the ductus arteriosus. Operation was done through left thoracotomy with the aid of partial cardiopulmonary bypass. The pulmonary arterial end of the ductus arteriosus was closed and a Ligamentum arteriosus was identified. A 3 by 2.7 cm saccular aneurysm was resected and segmental replacement of the aorta with woven dacron graft was performed. Because of it's critical location and the high incidence of complications, aneurysm of the ductus arteriosus in the adult should be surgically corrected when diagnosed.

Aged↗

PubMed1998

[Primary leiomyosarcoma of the heart, report of a case and review of the literature].

Primary cardiac neoplasms are unusual and are found in only about 0.0017% of autopsies. Approximately 25% of primary cardiac neoplasms are malignant. A case of primary leiomyosarcoma arising from the right ventricle and the pulmonary artery is reported. A 37-year-old man had sudden dyspnea and chest pain. Angiocardiography and MRI revealed moving masses throughout the right ventricle and the pulmonary arteries. An emergent surgery was performed. The multiple tumors were observed and incomplete resection was done. The patient was survived with the aid of a veno-arterial bypass as an assisted circulation on the first postoperative day. However, he gradually became deteriorated again and died 8 days after the operation due to the right ventricular failure. Eleven cases of the primary cardiac leiomyosarcoma including our case in the Japanese literature were reviewed briefly.

Adult↗

PubMed1998

Intracellular mechanisms of nitric oxide plus hydrogen peroxide-mediated neutrophil adherence to cultured human endothelial cells.

OBJECTIVE AND DESIGN: We investigated signal-transduction in nitric oxide/hydrogen peroxide (NO/H2O2) mediated neutrophil-endothelial adhesion and P-selectin mobilization. MATERIALS AND METHODS: Human endothelial monolayers (HUVEC) were exposed to 0.1 mM H2O2 plus an NO donor, 0.5 mM spermine-NONOate, and second message inhibitors and neutrophil adhesion and P-selectin expression measured. RESULTS: Neutrophil adherence induced by NO/H2O2 was blocked by a PKG inhibitor, (KT5823, 0.5 microM), a PKC inhibitor, (Go6976, 10 nM), a calcium chelator, TMB-8 (0.1 mM) and a K+ channel blocker, glibenclamide, (10 microM), but not by a PKA inhibitor, (H-89, 0.1 microM) or a tyrosine kinase inhibitor, (genistein, I microM). P-selectin expression induced by NO/H2O2 was blocked by KT5823 and Gö6976, but not by TMB-8 or glibenclamide. CONCLUSIONS: These data demonstrate that NO/ H2O2 promotes neutrophil-endothelial adhesion through PKG, PKC, calcium, and K+ channels, but not PKA or tyrosine kinase. Conversely, P-selectin mobilization requires only PKG and PKC.

Calcium↗

PubMed1998

In vitro protein phosphorylation associated with cellular differentiation of Streptomyces griseus.

In vitro phosphorylation reactions with crude cellular extracts revealed that phosphorylation of a 17-kDa protein is associated with the onset of aerial mycelium formation in solid culture (but not submerged spore formation in liquid culture) of Streptomyces griseus. The possible importance of the 17-kDa protein phosphorylation in cellular differentiation was further indicated by inducing aerial mycelium formation in the presence of decoyinine and in studies using certain developmental mutants (relC, afsA, and M-1). It is proposed that the 17-kDa protein may play a role in cellular differentiation of S. griseus via its phosphorylation.

Bacterial Proteins↗

PubMed1998

Estimation of absorbed dose for 2-[F-18]fluoro-2-deoxy-D-glucose using whole-body positron emission tomography and magnetic resonance imaging.

The purpose of this study was to measure the cumulated activity and absorbed dose in organs after intravenous administration of 2-[F-18]fluoro-2-deoxy-D-glucose (18F-FDG) using whole-body positron emission tomography (PET) and magnetic resonance imaging (MRI). Whole-body dynamic emission scans for 18F-FDG were performed in six normal volunteers after transmission scans. The total activity of a source organ was obtained from the activity concentration of the organ measured by whole-body PET and the volume of that organ measured by whole-body T1-weighted MRI. The cumulated activity of each source organ was calculated from the time-activity curve. Absorbed doses to the individuals were estimated by the MIRD (medical internal radiation dosimetry) method using S-values adjusted to the individuals. Another calculation of cumulated activities and absorbed doses was performed using the organ volumes from the MIRD phantom and the "Japanese reference man" to investigate the discrepancy of actual individual results against the phantom results. The cumulated activities of 18 source organs were calculated, and absorbed doses of 27 target organs estimated. Among the target organs, bladder wall, brain and kidney received the highest doses for the above three sets of organ volumes. Using measured individual organ volumes, the average absorbed doses for those organs were found to be 3.1x10(-1), 3.7x10(-2) and 2.8x10(-2) mGy/MBq, respectively. The mean effective doses in this study for individuals of average body weight (64.5 kg) and the MIRD phantom of 70 kg were the same, i.e. 2.9x10(-2) mSv/MBq, while for the Japanese reference man of 60 kg the effective dose was 2.1x10(-2) mSv/MBq. The results for measured organ volumes derived from MRI were comparable to those obtained for organ volumes from the MIRD phantom. Although this study considered 18F-FDG, combined use of whole-body PET and MRI might be quite effective for improving the accuracy of estimations of the cumulated activity and absorbed dose of positron-labelled radiopharmaceuticals.

Adult↗

PubMed1998

Estimation of internal absorbed dose of L-[methyl-11C]methionine using whole-body positron emission tomography.

L-[Methyl-11C]-methionine (11C-methionine) is proposed as a useful radiotracer for tumour diagnosis. Human biodistribution data of cumulated activities and absorbed doses estimated by the MIRD (medical internal radiation dosimetry) method for 11C-methionine are not available in the literature. In this study we measured the organ activity for 11C-methionine by using whole-body positron emission tomography (PET) and estimated the absorbed doses to 25 organs by the MIRD method. Whole-body dynamic PET scans were performed on five normal volunteers to measure the time course of the organ activity concentration (activity/volume) after intravenous administration of 11C-methionine. Cumulated activities of the ten source organs were calculated from the time-activity curves, obtained from the dynamic PET data. Absorbed dose estimates were performed by the MIRD method for the Caucasian reference man and for the Japanese reference man. The organs which received the highest absorbed doses for the Caucasian reference man were found to be the bladder wall (2.7x10(-2) mGy/MBq), the pancreas (1.9x10(-2) mGy/ MBq), the liver (1.8x10(-2) mGy/MBq) and the kidney (1.1x10(-2) mGy/MBq). The effective doses for the Caucasian reference man and the Japanese reference man were calculated as 5.2x10(-3) and 5.0x10(-3) mSv/MBq, respectively.

Adult↗

PubMed1998

Immunohistochemical and urinary markers of podocyte injury.

Renal podocytes play an important role in glomerular filtration. We estimated podocyte injury by light microscopic examination of kidney specimens or by urinary excretion of substances related to podocytes. Fresh kidney sections from 69 patients and urinary sediments from 84 patients with various renal diseases were examined immunohistochemically using fluorescent labelling. Four kinds of monoclonal antibodies which recognize podocytes were used: (1) anti-podocalyxin (anti-PCX) antibody, (2) anti-C3b receptor (anti-C3bR) antibody, (3) anti-podocyte protein, 44 kilodalton, (anti-pp44) antibody, and (4) anti-alpha 3 integrin (anti-Int alpha3) antibody. Labelling of kidney sections by anti-C3bR (k-C3bR) was reduced in cases of severe glomerular injury, although there were no changes in k-PCX, k-pp44, or k-Int alpha3 labelling. PCX labelling of urinary sediments (u-PCX) was detected in nearly all cases of glomerulonephritis, u-C3bR was seen in some cases of glomerular injury, u-Int alpha3 was seen in only a small number of cases of severe glomerular injury, and u-pp44 was not detected in any urinary samples. u-PCX, u-C3bR, u-Int alpha3, and k-C3bR correlated with the degree of pathological change, the degree of proteinuria and hematuria. These results suggest that immunostaining kidney sections with anti-C3bR antibody and urinary sediments with anti-PCX, anti-C3bR, and anti-Int alpha3 antibodies might be useful in detecting podocyte injury.

Adolescent↗

PubMed1998

Lymphoma arising in mucosa-associated lymphoid tissue of the duodenal bulb.

We report a case of low-grade B-cell lymphoma of the duodenal bulb arising from mucosa-associated lymphoid tissue. A barium swallow and an endoscopic examination showed multiple elevated, irregularly contoured lesions limited to the duodenal bulb. Endoscopic biopsy specimens were highly suggestive of non-Hodgkin's lymphoma. The resected specimen showed a gyriform mucosal elevation measuring 3 x 2cm in extent, with multiple small polypoid elevations scattered around it. Histologically, the small lymphocytes constituting the tumor infiltrated the duodenal mucosa and submucosa. The neoplastic centrocyte-like cells tended to grow around reactive lymphoid follicles and to invade epithelial structures, forming characteristic lymphoepithelial lesions. Monoclonal proliferation of the lymphoid tissue was demonstrated by the polymerase chain reaction method. The histologic appearance and the demonstration of monoclonality fulfilled the criteria for malignant lymphoma arising from mucosa-associated lymphoid tissue, which is extremely rare in the duodenum.

Duodenal Neoplasms↗

PubMed1998

Carcinoid of the esophagus located in lamina propria.

We report a carcinoid tumor in the mucosal layer of the esophagus of a 63-year-old man. Barium X-ray and endoscopy indicated the tumor to be a polypoid lesion in the lower esophagus. Endoscopic ultrasonography (EUS) demonstrated the lesion to be a sharply demarcated hyperechoic tumor in the mucosal layer. Biopsy yielded a diagnosis carcinoid of the esophagus. In the resected specimen of the esophagus, the tumor was 11 mm in longest dimension with a shallow depression on it smooth surface. Histologically, the tumor was located in the mucosal layer, as shown by EUS, and was composed of small round cells which were positive for argyrophil, but not argentaffine. Carcinoid tumor of the esophagus found at an early stage, and localized in the lamina propria layer, is very rare. The present case is the second report in Japan.

Carcinoid Tumor↗

PubMed1998

Identification by differential display of eight known genes induced during in vivo intimal hyperplasia.

To achieve a better understanding of the mechanism of intimal thickening, we used a rabbit model in which aorta was denuded mechanically by a balloon catheter. Total RNA was prepared from each aorta 1, 2, 7, 14, 23, or 30 days after denudation, and from intact aorta of non-denuded control rabbits. Subsequently, using the differential display method, we identified eight genes that were expressed differently during the time course after injury. One of them, RESP18 (encoding regulated endocrine secretory protein 18), was suppressed during the acute reaction. The other seven showed increase in expression during the acute phase: the genes for hTAFII68 (human TATA-binding protein associated factor), NPAT (nuclear protein mapped to the AT locus), OSF2 (osteoblast-specific factor 2), Pyst1, casein kinase 1 alpha, integrin alpha 1, and XP-C complementing protein. Although hTAFII68, NPAT, OSF2, and Pyst1 are thought to be related to transcription, not all four are positive regulators. Considering that none of these genes had previously been reported as being implicated in intimal hyperplasia, we conclude that many known or unknown genes play roles in this process. We believe that differential display is an effective method for screening genes whose variations in expression can provide clues toward understanding the molecular mechanism of intimal hyperplasia.

Animals↗

PubMed1998

Development of Epstein-Barr virus-associated B cell lymphoma after intensive treatment of patients with angioimmunoblastic lymphadenopathy with dysproteinemia.

Evolution of angioimmunoblastic lymphadenopathy with dysproteinemia (AILD) into aggressive B cell lymphoma is thought to be a rare event and the cause of this transformation has not been fully elucidated. We describe two patients with AILD that progressed to aggressive large-cell lymphoma with a B cell phenotype. At presentation, the lymph nodes of both patients showed the typical features of AILD by hematoxylin-eosin staining. Immunohistochemical staining with monoclonal antibodies revealed positive staining of atypical cells with UCHL-1 and negative staining with L-26. In situ hybridization of EBV RNA showed rare positive cells in one patient and was negative in the other patient. At relapse, both patients showed systemic lymph nodes swelling, which is characteristic of diffuse large immunoblastic lymphoma. Single-cell analysis with monoclonal antibodies and immunohistochemical staining showed the monoclonal proliferation of B cells. Southern blot analysis of the lymph nodes showed a rearrangement in both patients of the Ig heavy chain gene and germ line configuration of the T cell receptor beta chain gene. Southern blot analysis using the EBV terminal repeat region probe detected clonal proliferation of EBV in the lymph nodes of both patients. In situ hybridization studies identified considerable EBV mRNA in both patients. These observations suggest that EBV proliferation plays an important role in the development of B cell lymphoma that arises from AILD. We suggest that infection or reactivation of EBV may occur in some patients with AILD, probably due to their immunodeficient state, and that this infection or reactivation is directly involved in the development of B cell lymphoma.

Herpesviridae Infections↗

PubMed1998

Effect of dietary linoleate/alpha-linolenate balance on experimentally induced gastric injury in rats.

Rats were fed diets containing different ratios of linoleate (18:2 n-6) to alpha-linolenate (18:3 n-3), and the severity of gastric injury induced by ethanol, ischemia/reperfusion and water-immersion stress was compared. On decreasing the 18:2 n-6/18:3 n-3 ratios in the diets, the proportion of arachidonic acid (20:4 n-6) decreased and that of eicosapentaenoic acid (20:5 n-3) increased in the phospholipids of the gastric mucosa, which was associated with decreased mucosal prostaglandin E2 content. Mucosal injury in all the three experimental models was exacerbated significantly in the diet group fed 18:2 n-6/18:3 n-3 ratio of 0.25 (perilla oil) as compared with the groups fed dietary oils with 18:2 n-6/18:3 n-3 ratios of 2.7 (mixture of perilla and safflower oils) and 127 (safflower oil). This adverse effect induced by perilla oil diet was not observed when rats were pretreated with a mild irritant (20% ethanol) prior to challenge with a strong irritant (absolute ethanol). Furthermore, an 18:2 n-6/18:3 n-3 ratio of as low as 1 was found to be in a safe range in the water-immersion stress ulcer model. Thus, oils with very low n-6/n-3 ratios, for example perilla oil, could be used without the risk of the observed adverse effects on experimental gastric injury in people of industrialized countries ingesting foods with n-6/n-3 ratios of above 4. A decrease in the n-6/n-3 ratios to 2 or below is still recommended for the prevention of chronic diseases in the elderly related to atherosclerosis and inflammation.

Animals↗

PubMed1998

Growth stimulation of non-small cell lung cancer xenografts by granulocyte-macrophage colony-stimulating factor (GM-CSF).

Granulocyte-macrophage colony-stimulating factor (GM-CSF) has been suggested to be involved in the carcinogenesis of some types of tumours by autocrine or paracrine mechanisms. We examined GM-CSF/GM-CSF receptor (GM-CSFR) gene expression in 20 human non-small cell lung cancer (NSCLC) xenografts. The stimulatory effects of GM-CSF were examined using GM-CSF transgenic severe combined immunodeficient (SCID) mice (GM-Tg-SCID), which produce abundant human GM-CSF. A NSCLC xenograft (LC11-JCK), expressed GM-CSFR but not GM-CSF, and showed more rapid growth in GM-Tg-SCID than non-GM-CSF transgenic SCID mice (non-Tg-SCID). GM-CSF gene expression was detected in 48 of 90 (53%) primary NSCLC human specimens and GM-CSFR gene expression was detected in 42 specimens (47%). GM-CSF expression was detected in 13 of 30 squamous cell carcinoma specimens (43%) and GM-CSFR expression was detected in 10 specimens (33%). Patients with squamous cell carcinoma coexpressing GM-CSF and GM-CSFR showed significantly poorer prognosis than those expressing neither GM-CSF nor GM-CSFR (P < 0.05, Cox-Mantel test). These results suggest that GM-CSF can have a stimulatory effect on some NSCLC.

Animals↗

PubMed1998

Origin and decay of the P element-associated latitudinal cline in Australian Drosophila melanogaster.

The latitudinal cline in P transposable element-associated characteristics in eastern Australian populations of Drosophila melanogaster has changed between 1986 and 1991-1994. New collections were made in 1991-1994 from localities along the eastern coast of Australia. P element-associated properties of 256 isofemale lines from 43 localities were evaluated using gonadal dysgenesis and/or singed-weak hypermutability assays. The overall results indicate that both P activity and P susceptibility have declined, with all populations showing a tendency towards a state with little P activity potential but with P repressor function (neutral or 'Q'). P repressor function is strong in all populations except some of the most southernly. P activity potential peaks at about 27 degrees SLat, and drops off to the south (as in 1983-1986 collections) and to the north (in contrast to 1983-1986 collections); thus the cline is no longer a simple P-to-Q-to-M pattern from north to south, but is now Q-P-Q-M. A mtDNA RFLP that putatively distinguishes North American and European populations varies in frequency among the populations but the frequency does not vary clinically with latitude, ruling out massive introductions from North America and Europe as causing the cline.

Animals↗

PubMed1998

Regulatory mechanism of pepsinogen gene expression in monolayer cultured guinea pig gastric chief cells.

We have investigated the effects of dibutyryl cAMP, forskolin, carbamylcholine chloride (carbachol), ionomycin, and 12-O-tetradecanoylphorbol-13-acetate (TPA) on the expression of guinea pig pepsinogen mRNA in monolayer cultured gastric chief cells. After exposure of the cells to each of these compounds for 4 to 24 hr, and at 48 hr after primary culture, total cellular RNA was isolated using acid guanidium-phenol-chloroform and then was reverse transcribed to cDNA. Obtained cDNA was amplified by polymerase chain reaction (PCR) using primers detecting guinea pig pepsinogen mRNA and human beta-actin mRNA as an internal standard. The PCR products were separated and quantified using capillary electrophoresis. Dibutyryl cAMP and forskolin significantly increased pepsinogen mRNA, but carbachol, ionomycin, and TPA failed to increase that. These findings suggested that pepsinogen gene expression was up-regulated by intracellular cAMP, but not by intracellular calcium or protein kinase C in guinea pig chief cells.

Animals↗

PubMed1998

Selective uptake of selenite by red blood cells.

Both organic and inorganic forms of selenium (Se) can be utilized in the body, and the biotransformation of selenite into an organic form of Se in the bloodstream is the first step for the utilization of inorganic Se. Selenite injected intravenously into rats was shown to be taken up rapidly and selectively by red blood cells (RBCs) through the anion-exchange carrier. The uptake of selenite by RBCs was inhibited by 4,4'-diisothiocyano-2,2'-stilbene disulfonate, a specific inhibitor of the anion-exchange carrier (band 3 protein). The uptake was also inhibited by chromate owing to the glutathione deprivation in RBCs, which was confirmed by the inhibition by azodicarboxylic acid bis(dimethylamide). The presence of hydrogencarbonate in the incubation solution slightly retarded the uptake of selenite by RBCs. Although Se effluxed into the plasma was bound selectively to albumin, plasma proteins (albumin) did not accelerate the uptake process. Based on these results, the rapid and selective uptake of selenite by RBCs was explained by the selective and efficient uptake through the anion-exchange carrier, followed by reduction by glutathione.

Animals↗