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Biomedical subjects

T Tsuji

Publications and source records attributed to T Tsuji.

At least 505 records · Page 28Linked to original sources
PubMed1996

Characterization of murine stromal cell clones established from bone marrow and spleen.

Stromal cell lines were established by irradiating adherent layers of bone marrow and spleen cells in Dexter-type long-term culture with X-rays. Some of these cell lines support myelopoiesis and/or B lymphopoiesis in vitro. Furthermore, the characteristics of these stromal cell lines were studied. Cytokine activity was detected in the conditioned media from all hematopoietic-supportive and non-supportive stromal cells. Quantitative reverse transcriptase-polymerase chain reaction analysis revealed that the mRNAs of macrophage colony-stimulating factor and stem cell factor, but not that of Interleukin-3, were detectable in all the hematopoietic-supportive and non-supportive stromal cell lines. The transcripts of granulocyte colony-stimulating factor, interleukin-6, interleukin-7, and leukemia inhibitory factor were expressed in a wide variety of cell lines. Most stromal cell lines synthesized mRNA of c-mpl, the ligand of which stimulates megakaryopoiesis and thrombopoiesis. These observations indicate that the pattern of mRNA expression of cytokines is not correlated with the hematopoietic-supportive ability of stromal cell lines. There was a significant difference in the efficiency of adhesion of lineage marker-negative bone marrow cells to fibroblasts and stromal cell lines. This appears to be correlated with the hematopoietic-supportive ability of the stromal cell lines.

3T3 Cells↗
PubMed1996

[HLA antigens in patients with testicular germ cell tumors].

The role of HLA antigens in the etiology of testicular germ cell tumor has been suggested previously. Several attempts have been made to establish associations of HLA antigens in patients with testicular cancers, but have yielded inconsistent results. We studied the frequencies of HLA antigens by serological typing and DNA typing and examined the association between testicular germ cell tumors and HLA antigens. The serological expression of HLA-A, -B, -C, -DR and -DQ antigens was analyzed in 23 patients with germ cell cancers of the testis. The findings indicated a trend towards an increase in the antigen DQ4 (p < 0.05). The 13 patients were typed for HLA DRB1 and DQB1 allele by PCR-RFLP analysis. The findings revealed an increased frequency of DRB1 0405 (p < 0.01) and DQB1 0401 (p < 0.01).

Adult↗
PubMed1996

Cytochrome P450s of isolated rat hepatocytes in spheroid and monolayer cultures.

The maintenance of cytochrome P450s (P450s) and NADPH-cytochrome P450 reductase (P450 reductase) in the monolayer and spheroid cultures of hepatocytes from male rats was examined. The content of total P450 in monolayer culture decreased to almost none after 144 hr, whereas the level in spheroid culture remained within 6-13% of initial values during an incubation period of 144-192 hr. P450 2C11, a major P450 in male rat, in monolayer cells rapidly decreased in 144 hr, while the level in spheroid cells after 144 hr and 192 hr maintained 25% and 15%, respectively, of initial level. On the other hand, P450 2A1 and P450 2E1 in both monolayer and spheroid cells rapidly decreased. P450 reductase in both cells showed a gradual decline reaching a level of 43-44% of the initial level at 96 hr, and remained within 16-17% of the initial value during an incubation period of 192 hr. These results indicate that P450 2C11 in spheroid cells maintained more stable than in the monolayer cells, and that P450 reductase in both cultures declined only moderately, compared with P450s.

Animals↗
PubMed1996

Detection of hepatitis C virus core protein in the glomeruli of patients with membranous glomerulonephritis.

Two Japanese patients suffered from membranous glomerulonephritis associated with hepatitis C virus (HCV) infection. Renal histologic changes were characterized by granular deposits of IgG and C3 along the capillary wall and numerous subepithelial deposits in glomeruli. Hypocomplementemia was present in one patient, but both cryoglobulins and rheumatoid factors were absent. HCV RNA was detected in both their sera by RT-PCR, both free and in the form of circulating immune complexes. The HCV core protein was found in the glomeruli from both patients by indirect immunofluorescence. These results suggest that in some patients chronic HCV infection causes membranous glomerulonephritis through immune complex deposition involving HCV proteins.

Aged↗
PubMed1996

[Diagnostic value of high N-isopropyl-p-[123I] iodoamphetamine (IMP) uptake in brain tumors].

The diagnostic value of high N-isopropyl-p-[123I] iodoamphetamine (123I-IMP) uptake in histologically proven intracranial tumors was evaluated in 54 patients with both early (15-35 min after injection) and delayed (4 hours) SPECT before treatment. Higher uptake in the tumor compared with normal cerebral cortex was observed in early scans in all of the five patients with primary intracranial malignant lymphoma, in two of 16 meningiomas, two of seven astrocytomas, one of three pituitary adenomas, and one central neurocytoma. Among these 11 cases all the malignant lymphomas showed persistent high uptake in delayed scans, whereas other tumors showed decreased uptake in delayed scans. This persistent high 123I-IMP uptake was characteristic of primary intracranial malignant lymphomas and was useful in the diagnosis of intracranial malignant lymphoma.

Adult↗
PubMed1996

Mucha-Habermann disease and its febrile ulceronecrotic variant.

In 1916 Mucha and in 1925 Habermann reported an acute form of pityriasis lichenoides characterized by the abrupt onset of papulovesicular eruptions and gave the name, pityriasis lichenoides et varioliformis acuta (PLEVA) or Mucha-Habermann disease (MH). In 1966, Degos reported a rare febrile ulceronecrotic variant of MH. MH occurs mainly in young adults, while febrile ulceronecrotic Mucha-Habermann's disease (FUMHD) occurs more frequently in children. The etiology of MH remains obscure, but it may be the result of a hypersensitivity reaction to an infectious agent. Although clinical and histologic features of the disease in children are similar to those of adults, more diseases need to be differentiated in pediatric patients. In addition, a number of effective therapeutic options in adults with MH are unsuitable for use in pediatric patients, to whom beginning with oral antibiotics, usually erythromycin, is recommended. A summary of previously reported fifteen cases with FUMHD, including our case, is listed.

Adolescent↗
PubMed1996

Cellular distribution of 92-kd type IV collagenase/gelatinase B in human hepatocellular carcinoma.

To examine the possible involvement of gelatinase B in human hepatocellular carcinoma (HCC), cellular localization of transcripts and protein of gelatinase B were studied by using in situ hybridization and immunohistochemistry. Transcripts for gelatinase B were observed in tumor cells in 22 cases of 27 HCCs and also in dysplastic nodules. However, there was no significant difference in the expression among histological grades of HCC. The expression was mostly homogeneous, but the intensity varied with the nodules. Of 13 cases with capsular invasion, 12 expressed gelatinase B, whereas 10 of 14 without capsular invasion did (P < 0.05). Gelatinase B transcripts were commonly observed in the sinusoidal cells of the hepatic lobules, in mesenchymal cells both in fibrous capsules and around the necrosis, and also in some undefined cells of the portal tracts of noncancerous liver. Localization of gelatinase B protein was mostly similar to but sometimes different from that of the transcripts in cancer nodules. In conclusion, the expression of gelatinase B appears to be an important characteristic of malignant transformation of hepatocytes. The findings suggest that gelatinase B synthesized by cancer cells plays an important role in the growth and invasion of HCC by degrading surrounding extracellular matrices.

Adult↗
PubMed1995

Identification of two isoforms of mouse neuropeptide Y-Y1 receptor generated by alternative splicing. Isolation, genomic structure, and functional expression of the receptors.

Two cDNA clones homologous with human neuropeptide (NP) Y-Y1 receptor have been isolated from a mouse bone marrow cDNA library. One was thought to be the cognate of the human NPY-Y1 receptor, termed Y1 alpha receptor, and the other form, termed Y1 beta receptor, differed from the Y1 alpha receptor in the seventh transmembrane domain and C-terminal tail. Analysis of the mouse genomic DNA showed that both receptors originated from a single gene. The different peptide sequences of the Y1 beta receptor were encoded by separate exons, hence, these receptors were generated by differential RNA splicing. High affinity binding of [125I]NPY to each receptor expressed in Chinese hamster ovary (CHO) cells and sequestration of [125I]NPY after binding to each receptor were observed. In the CHO cells expressing the Y1 alpha receptor, intracellular Ca2+ increase, inhibition of forskolin-induced cAMP accumulation, and mitogen-activated protein kinase (MAPK) activation were observed by stimulation of NPY, and these responses were abolished by pretreatment with pertussis toxin. Since wortmannin completely inhibited NPY-elicited MAPK activation, we speculate that wortmannin-sensitive signaling molecule(s) such as phosphoinositide 3-kinase may lie between pertussis toxin-sensitive G-protein and MAPK. In contrast, these intracellular signals were not detected in CHO cells expressing the Y1 beta receptor. Northern blots and reverse transcriptase-polymerase chain reaction analyses indicated that the Y1 alpha receptor was highly expressed in the brain, heart, kidney, spleen, skeletal muscle, and lung, whereas the Y1 beta receptor mRNA was not detected in these tissues. However, the Y1 beta receptor was expressed in mouse embryonic developmental stage (7 and 11 days), bone marrow cells and several hematopoietic cell lines. These results suggest that the Y1 beta receptor is an embryonic and a bone marrow form of the NPY-Y1 receptor, which decreases in the expression during development and differentiation.

Alternative Splicing↗
PubMed1995

Activation induces dephosphorylation of cofilin and its translocation to plasma membranes in neutrophil-like differentiated HL-60 cells.

We suggested that a cytosolic 21-kDa phosphoprotein played an important role in opsonized zymosan-trigered activation of superoxide-generating enzyme in neutrophil-like HL-60 cells through dephosphorylation (Suzuki, K., Yamaguchi, T., Oshizawa, T., Yamamoto, Y., Nishimaki-Mogami, T., Hayakawa, T., and Takahashi, A (1995) Biochim. Biophys. Acta 1266, 261-267). In the present study, we characterized the phosphoprotein and studied changes in it localization upon activation of phagocytes. The 21-kDa phosphoprotein was rapidly dephosphorylated upon activation not only wit opsonized zymosan but also with formyl-Met-Leu-Phe and arachidonic acid. The peptide fragments derived from the 21-kDa phosphoprotein were found to have the same amino acid sequences as those of cofilin, an actin-binding protein. The phosphoprotein reacted exclusively with anti-cofilin antibody on two dimensional immunoblots. Accordingly, together with its apparent molecular weight, isoelectric point, and detection of phosphoserine as a phosphoamino acid, we concluded that the 21-kDa phosphoprotein was a phosphorylated form of cofilin. The amount of cofilin in membranous fractions was increased upon activation. Furthermore, confocal laser scanning microscopy showed that cofilin existed diffusely in the cytosol and nuclear region of the resting cells, while in the activated cells, it was accumulated at the plasma membrane area, forming ruffles or endocytic vesicles on which O2.- should be produced. These results suggested that in resting cells cofilin exists as a soluble phosphoprotein in the cytosol and nuclei, while upon stimulation a large portion of cofilin is dephosphorylated and translocated to the plasma membrane regions.

Actin Depolymerizing Factors↗
PubMed1995

Q-wave regression unrelated to patency of infarct-related artery or left ventricular ejection fraction or volume after anterior wall acute myocardial infarction treated with or without reperfusion therapy.

We examined the relation of Q-wave regression to left ventricular (LV) indexes in acute anterior wall myocardial infarction (AMI) in relation to reperfusion therapy. A total of 94 patients with their first anterior wall AMI (segment 6 or 7 occlusion according to the American Heart Association classification) were examined. The follow-up period with 12-lead electrocardiograms ranged from 6 to 60 months (mean 24 +/- 18). An abnormal Q wave was defined as > 40 ms and > 25% of the R-wave amplitude. Q-wave regression was defined as Q-wave disappearance and r-wave regression > 0.1 mV in > or = 1 lead. Contingency tables with the chi-square test and analysis of variance were used for assessment of the relation between Q-wave regression and angiographic and clinical indexes. Q-wave regression in > or = 1 lead was found in 77% of the patients. The incidence of Q-wave regression in patients with patent infarct-related artery (81%) was not significantly different from that in those with an occluded lesion (67%). Q-wave regression appeared within 1 month in 60% of patients with a patent infarct-related artery but in 25% of those with an occluded lesion. No difference in the incidence of Q-wave regression was seen between patients with lesions at segments 6 (81%) and 7 (70%), or between those with (75%) and without (77%) collateral circulation. Q-wave regression did not correlate with LV ejection fraction, LV end-diastolic or end-systolic volumes, or regional wall motion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

cDNA cloning of mouse VLA-3 alpha subunit.

cDNA clones for mouse VLA (very late antigen)-3 alpha subunit (alpha 3 integrin) were isolated and sequenced. The encoded mouse alpha 3 integrin subunit was composed of 1,053 amino acid residues. The results of sequence analysis revealed similar structural characteristics of other VLA alpha subunits. For example, the presence of a large extracellular domain including three putative metal binding sequences, a transmembrane domain, and a short cytoplasmic domain. A higher level of its message was detected in thymus than in kidney, stomach, spleen, liver, brain, or lung by Northern blotting analysis.

3T3 Cells↗
PubMed1995

Characterization of human colon carcinoma variant cells selected for sialyl Lex carbohydrate antigen: liver colonization and adhesion to vascular endothelial cells.

The content of sialyl Lewis-X antigen (Neu5Ac alpha 2-3Gal beta 1-4(fuc alpha 1-3)GlcNAc-R: sialyl Le(x)) was previously shown to correlate with the progression of human colon carcinomas to the advanced stages. Variant cell lines with high (KM12-HX) or low (KM12-LX) levels of cell surface sialyl Le(x) were isolated from the heterogeneous KM12C cells to characterize the biological behavior of colon carcinoma cells with elevated cell surface contents of sialyl Le(x). When these cells were injected intrasplenically into nude mice, KM12-HX cells colonized to the liver more efficiently than KM12-LX cells. Under in vitro conditions, KM12-HX cells demonstrated greater degree of adhesion to cytokine-activated human umbilical vein endothelial cells than KM12-LX cells. The adhesion of KM12-HX cells was partially inhibited by antibodies specific for E-selectin, which was known to serve as a ligand for the sialyl Le(x) carbohydrate antigen. The treatment of KM12-HX cells with benzyl N-acetyl-alpha-D-galactosaminide, a putative inhibitor of the extension of O-linked carbohydrate chains, reduced the rate of adhesion. These results suggested that the interaction of endothelial cell surface E-selectin with O-linked carbohydrate chains on colon carcinoma cell surface glycoproteins played an important role in the adhesion.

Animals↗
PubMed1995

Human hand impedance characteristics during maintained posture.

The present paper examines human hand impedance characteristics, including inertia and viscosity as well as stiffness, in multi-joint arm movements. While a subject maintains a given hand location, small external disturbances are applied to his hand by a manipulandum. The corresponding force-displacement vectors are measured and sampled over time in order to estimate the hand impedance by means of a second-order linear model. The experimental results in different subjects and hand locations are summarized as follows: (1) the estimated inertia matrices of the human hand well agrees with computed values using a two-joint arm model, (2) spatial variations of the stiffness ellipses are consistent with the experimental results of Mussa-Ivaldi et al. (1985), (3) hand stiffness and viscosity increase with the grip force of the subject, and (4) viscosity and stiffness ellipses tend to have similar orientation. The accuracy of the impedance estimation method is validated with a mechanical spring-mass system with known parameters.

Adult↗
PubMed1995

Brain tissue identification based on myosin heavy chain isoforms.

Non-muscle tissues contain 3 myosin heavy chain (MHC) isoforms; MIIA, MIIB1 and MIIB2. MIIA is a non-muscle type isoform distributed in all non-muscle tissues and smooth-muscle, while MIIB1 and MIIB2 are brain-type isoforms distributed mainly in neuronal tissues. The ratio of MIIA and MIIB (A/B ratio) differs between tissues, suggesting that this ratio may be a useful marker for tissue identification. To apply the A/B ratio for tissue identification in forensic practice, we developed a highly sensitive ELISA for quantification of each MHC isoform. At least 100 pg of both MHC isoforms could be detected by the present method. Analysis of the A/B ratio of the cerebrum, cerebellum, liver, kidney, spleen and andrenal gland by the present method indicated that the A/B ratio of the brain tissue (< 0.5) was quite different from other tissues (> 3.0). The A/B ratio could be determined from at least 8 micrograms of fresh tissue sample and 0.1 mg of dried tissue sample stored for 1 month at room temperature. Therefore, the A/B ratio seems to be an excellent marker for identification of the brain tissue.

Adrenal Glands↗
PubMed1995

Analysis of asparagine-linked oligosaccharides by sequential lectin affinity chromatography.

Lectins are proteins that specifically bind to a particular carbohydrate structure. Affinity chromatography with immobilized lectins is a quite effective technique not only for the fractionation of glycoproteins or oligosaccharides but also their structural assessment. In this article, we focus on the separation of glycopeptides and oligosaccharides derived from glycoproteins by affinity chromatography on immobilized lectin columns.

Agglutinins↗
PubMed1995

Histologic modification by cryopreservation in rat aortic allografts.

Histologic changes after the cryopreserved rat aortic transplantation were studied, and the influences of the cryopreservation and of the allografting on the histology were examined. Four groups of Brown Norway (RT1n) and Lewis rats (RT1(1)) were used (n = 4 at each examined period in each group): the cryopreservation-allograft group (from Brown Norway to Lewis with cryopreservation), the cryopreservation-isograft group (from Lewis to Lewis with cryopreservation), the fresh allograft group (from Brown Norway to Lewis without cryopreservation), and the fresh isograft group (from Lewis to Lewis without cryopreservation). The graft was harvested from a descending thoracic aorta of a donor rat, implanted to an infrarenal abdominal aorta of a recipient rat, and extracted at 10 days, 1, 3, 6, and 12 months after the operation. The intimal thickening, cellular loss in the media, and cellular infiltration in the adventitia were observed, which were the same phenomena seen in chronic rejection of human organ allografts. Although the degree of intimal thickening and cellular loss in the media were higher in the cryopreserved groups than in the fresh groups, the cryopreservation procedure suppressed cellular infiltration in the adventitia after allotransplantation. The immunologic attack against the graft might be diminished by cryopreservation.

Animals↗
PubMed1995

Detection of decay-accelerating factor in stool specimens of patients with colorectal cancer.

BACKGROUND & AIMS: Colorectal cancers have an increased expression of decay-accelerating factor (DAF). The aim of this study was to determine whether stool specimens of patients with colorectal cancer contain increased amounts of DAF. METHODS: DAF was measured using an immunoassay in the stool specimens of 40 persons with colorectal cancer, 18 with colorectal adenomatous polyps, 13 with upper gastrointestinal cancer, and 41 without gastrointestinal disease. RESULTS: Stool DAF concentrations in patients with colorectal cancer (0-9.8 ng/g stool; median, 1.6 ng/g) were significantly higher than those in patients with adenoma (0-6.4 ng/g; median, 0 ng/g) (P < 0.05), patients with upper gastrointestinal cancer (0-3.1 ng/g; median, 0 ng/g) (P < 0.05), and subjects without gastrointestinal disease (0-3.4 ng/g; median, 0 ng/g) (P < 0.01). Resection of colorectal cancers caused a marked decrease in stool DAF concentrations. The stool DAF test was positive in a substantial portion of patients with colorectal cancer whose tumors were small ( < 2 cm), at an early TNM stage, or unassociated with fecal occult blood positivity. The sensitivity of the test for colorectal cancer was 55%, and the specificity was 85%. CONCLUSIONS: The measurement of stood DAF deserves evaluation as a test for detection of colorectal cancer.

Adenomatous Polyposis Coli↗