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T Kodama

Publications and source records attributed to T Kodama.

At least 379 records · Page 21Linked to original sources
PubMed1997

[Analysis of microsatellite regions and DNA ploidy pattern in signet ring cell carcinomas of the stomach].

We examined microsatellite instability (MSI) and loss of heterozygosity (LOH) in regions of several important genes in 25 signet-ring cell carcinomas of the stomach. The relationship between microsatellite analysis and DNA ploidy pattern was also investigated. MSI was observed in 15% (2/13) of early carcinomas and in 17% (2/12) of advanced carcinomas. Although LOH in the region of APC gene was found in 16% (4/25) and LOH of p53 was found in 12% (3/25), 15% (2/13) of early carcinomas and 33% (4/12) of advanced carcinomas showed LOH in regions of E-cadherin gene. Cyto-fluorometrical study revealed that 85% (11/13) of early carcinomas were diploid pattern, and aneuploid components were demonstrated in 50% (6/12) of advanced carcinomas. However, no MSI-positive cases contained aneuploid components, and in contrast, all p53-LOH cases contained aneuploid components. Our results suggest that gene abnormalities which have been frequently reported in differentiated adenocarcinomas are rare events in signet-ring cell carcinomas other than those associated with cell adhesion, and that MSI is not related to the occurrence of aneuploid cells.

Adult↗
PubMed1997

[Principles of histological diagnosis and clinical staging evaluation for lung cancer].

In the histological diagnosis, it is important to consider the presence of borderline lesions, the possibilities of multiple primary lung cancers and the differential diagnosis between small cell carcinoma and non-small cell carcinomas. In the definite diagnosis, moreover, it is necessary to refer to the special staining procedures, including immuno-histochemistry. In clinical trials, one must evaluate the precise clinical staging in addition to the pathological qualification for enrolled cases. On the other hand, the staging evaluation should be minimal in the practical treatment. It should be noticed that the staging procedure between non-small cell carcinoma and small cell carcinoma is different.

Carcinoma, Non-Small-Cell Lung↗
PubMed1997

[High-resolution CT of otosclerosis].

High-resolution CT (HRCT) scans of thirty-two patients (60 ears) with the clinical diagnosis of fenestral otosclerosis were evaluated retrospectively. HRCT was performed with 1-mm-thick targeted sections and 1-mm (36 ears) or 0.5-mm (10 ears) intervals in the semiaxial projection. Seven patients (14 ears) underwent helical scanning with a 1-mm slice thickness and 1-mm/sec table speed. Forty-five ears (75%) were found to have one or more otospongiotic or otosclerotic foci on HRCT. In most instances (30 ears), the otospongiotic foci were found in the region of the fissula ante fenestram. No significant correlations between CT findings and air conduction threshold were observed. We found a significant relationship between lesions of the labrinthine capsule and sensorineural hearing loss. We conclude that HRCT is a valuable modality for diagnosing otosclerosis, especially when otospongiotic focus is detected.

Adolescent↗
PubMed1996

Inhibition of transplant coronary arteriosclerosis in rabbits by chronic estradiol treatment is associated with abolition of MHC class II antigen expression.

BACKGROUND: Accelerated coronary arteriosclerosis is a major complication in long-term survivors of cardiac transplantation. Estrogen prevents transplant arteriosclerosis in experimental cardiac and aortic allografts and may act by an immune mechanism. METHODS AND RESULTS: New Zealand White rabbits immunosuppressed with cyclosporine were recipients of cardiac allografts from Dutch Belted rabbits. The recipients received either estradiol or placebo daily until they were killed 6 weeks later. Histological cross sections of the cardiac allograft were used for quantification of major histocompatibility complex (MHC) class II antigen expression, T lymphocytes, and macrophages by immunohistochemistry using monoclonal antibodies. MHC class II antigen expression was not detectable in allograft coronary arteries from any of the estradiol-treated recipients, whereas this antigen expression was present in the allograft coronary arteries from all the placebo-treated recipients. Macrophage and lymphocyte infiltration of the allograft coronary artery myointima was significantly less frequent in the estradiol-treated group. Rejection was moderate but slightly less in the estradiol-treated group. These findings were associated with a 60% decrease in allograft coronary artery myointimal thickening (determined by morphometry) in the estradiol-treated compared with the placebo-treated group. CONCLUSIONS: Estradiol treatment of cardiac allograft recipients abolishes MHC class II antigen expression in the coronary arteries and decreases macrophage infiltration in all three layers of the vessel wall, whereas T-lymphocyte infiltration is decreased only in the myointima. These findings are associated with estradiol inhibition of myointimal proliferation. Thus, estradiol treatment may have a beneficial effect on graft arteriosclerosis through immune mechanisms.

Animals↗
PubMed1996

Specific clonal T cell accumulation in intestinal lesions of Crohn's disease.

The initial cellular events that take place at the outset of autoimmune diseases and that may be the most important in terms of understanding their pathogenesis are poorly understood, especially in humans. This is mainly due to the difficulties in the identification of primary lesions and the accessibility to such material. In this respect, it is noteworthy that the appearance of small reddish erosions, known as aphthoid lesions, is known to be an early event in Crohn's disease. In the present study, accumulation of lesion-specific clonal TCR bands in the intestinal lesions of Crohn's disease patients was demonstrated by means of a highly sensitive method based on single strand conformational polymorphism. Such clonal accumulation was demonstrated in both aphthoid and discrete ulcer lesions. There were several TCR BV bands that were present in both aphthoid lesions and discrete ulcer lesions, but some were specific to the aphthoid lesions. In addition, the same aphthoid lesion-specific/dominant T cell clones were found to be expanded in separate aphthoid lesions of a single patient, and were absent from intervening, non-inflamed mucosa. Some of these bands may represent T cell clones activated primarily at the onset of disease.

Adolescent↗
PubMed1996

The scavenger receptor serves as a route for internalization of lysophosphatidylcholine in oxidized low density lipoprotein-induced macrophage proliferation.

We have recently demonstrated that the growth of murine macrophages is induced by oxidized low density lipoprotein (Ox-LDL) and that lysophosphatidylcholine (lyso-PC), a major phospholipid component of Ox-LDL, plays an essential role in its mitogenic effect. The present study was undertaken to further characterize the role of the macrophage scavenger receptor (MSR) in Ox-LDL-induced macrophage growth. The growth-stimulating effect of Ox-LDL on murine resident peritoneal macrophages was inhibited by maleylated bovine serum albumin (maleyl-BSA), a non-lipoprotein ligand for MSR but a poor carrier of lyso-PC, while maleyl-BSA itself failed to induce macrophage growth even in the presence of lyso-PC. Moreover, it competitively inhibited the endocytic uptake of 125I-Ox-LDL and the specific uptake of lyso-PC by MSR, whereas nonspecific lyso-PC transfer to cells was not affected. Furthermore, the Ox-LDL-induced cell growth of peritoneal macrophages obtained from MSR knockout mice was significantly weaker than that of macrophages obtained from their wild-type littermates. Our results suggest that the MSR is an important and efficient internalization pathway for lyso-PC in Ox-LDL-induced macrophage growth.

Albumins↗
PubMed1996

Role for the class A macrophage scavenger receptor in the phagocytosis of apoptotic thymocytes in vitro.

Numerous immature thymocytes undergo apoptosis and are rapidly engulfed by phagocytic thymic macrophages. The macrophage surface receptors involved in apoptotic thymocyte recognition are unknown. We have examined the role of the class A macrophage scavenger receptor (SR-A) in the engulfment of apoptotic thymocytes. Uptake of steroid-treated apoptotic thymocytes by thymic and inflammatory-elicited SR-A positive macrophages is partially inhibited by an anti-SR-A mAb and more completely by a range of scavenger receptor ligands. Thymic macrophages from mice with targeted disruption of the SR-A gene show a 50% reduction in phagocytosis of apoptotic thymocytes in vitro. These data suggest that SR-A may play a role in the clearance of dying cells in the thymus.

Animals↗
PubMed1996

Sterol-dependent transcriptional regulation of sterol regulatory element-binding protein-2.

We show in this manuscript that expression of the mRNA for sterol regulatory element-binding protein-2 (SREBP-2) is regulated by the cellular sterol level in cultured HeLa cells. We have cloned the 5'-flanking region of the gene encoding human SREBP-2. Characterization of this region shows the minimum 50-base pair segment, which contains a 10-base pair sterol regulatory element 1 (SRE-1) identical to the one in the human LDL receptor promoter, confers sterol responsiveness when fused to the luciferase reporter gene. Enforced expression of the truncated SREBP-2 protein (amino acid residues 1-481) also shows that this upstream segment contains the information required for transcriptional activation. The luciferase assays using mutant versions of the reporter genes reveal that the sterol-dependent transcriptional regulation is mediated by two nearby motifs, the SRE-1 and the NF-Y binding site (the inverted CCAAT box, ATTGGC); the latter is reported to play a critical role in sterol-dependent regulation of 3-hydroxy-3-methylglutaryl-coenzyme A synthase and farnesyl diphosphate synthase genes (Jackson, S. M., Ericsson, J., Osborne, T. F., and Edwards, P. A. (1995) J. Biol. Chem. 270, 21445-21448). Gel mobility shift assays demonstrate that the transcription factor NF-Y truly binds to the ATTGGC sequence. These findings suggest that the activity of SREBP-2 is controlled not only post-translationally by proteolytic activation of the precursor protein but also transcriptionally by itself together with NF-Y.

Binding Sites↗
PubMed1996

State-dependent changes of extracellular glutamate in the medial preoptic area in freely behaving rats.

Microdialysis technique was applied to the medial preoptic area (mPOA) of the hypothalamus, a crucial site for the regulation of sleep, in order to analyze the interrelationship between the extracellular level of glutamate (Glu) and the vigilance states. Dialysates from the mPOA were sampled at 5-min intervals for 2-h diurnal period with a perfusion rate of 2.0 microliters/min in freely moving rats, whose sleep-waking behaviors were polysomnographically monitored. Extracellular Glu increased during wakefulness, exhibiting a peak at the transition period from wakefulness to non-rapid-eye-movement sleep (NREMS) (18.0% above the average), whereas it decreased during NREMS (9.2% below the average). It is likely that Glu in the mPOA is dynamically involved in the alterations of the vigilance states.

Animals↗
PubMed1996

Involvement of specific macrophage-lineage cells surrounding arterioles in barrier and scavenger function in brain cortex.

The transport of solutes between blood and brain is regulated by a specific barrier. Capillary endothelial cells of brain are known to mediate barrier function and facilitate transport. Here we report that specific cells surrounding arterioles, known as Mato's fluorescent granular perithelial (FGP) cells or perivascular microglial cells, contribute to the barrier function. Immunohistochemical and in situ hybridization studies indicate that, in normal brain cortex, type I and type II macrophage scavenger receptors are expressed only in FGP/perivascular microglial cells, and surface markers of macrophage lineage are also detected on them. These cells mediate the uptake of macromolecules, including modified low density lipoprotein, horseradish peroxidase, and ferritin injected either into the blood or into the cerebral ventricles. Accumulation of scavenged materials with aging or after the administration of a high-fat diet results in the formation of honeycomb-like foam cells and the narrowing of the lumen of arterioles in the brain cortex. These results indicate involvement of FGP/perivascular microglial cells in the barrier and scavenger functions in the central nervous system.

Adult↗
PubMed1996

Regulation of fatty acid synthase expression by cholesterol in human cultured cells.

The regulation of fatty acid synthase (FAS) expression by sterols in a cultured human hepatoblastoma cell line, Hep G2, was studied. When cells were treated with compactin in a medium containing lipoprotein deficient serum, FAS mRNA level increased 1.6-fold. A squalene synthase inhibitor, TAN1607A, decreased both free and esterified cholesterol contents in Hep G2 cells and increased mRNA levels for FAS, HMG-CoA reductase, squalene synthase and LDL receptor. However, for the increment of FAS mRNA, a 10-fold higher concentration of this inhibitor was needed. These results demonstrate that the concentration of cellular cholesterol which regulates FAS expression is necessarily lower than the levels which regulate other sterol sensitive genes. FAS mRNA was also increased by an inhibitor of SREBP degradation as well as chenodeoxycholic acid. These results indicate that FAS mRNA expression is regulated by cholesterol and is mediated through SREBPs. The implications of the different modes of sterol regulation of FAS and LDL receptor expression are discussed.

Bridged Bicyclo Compounds, Heterocyclic↗
PubMed1996

Autotrophic carbon dioxide fixation in Acidianus brierleyi.

The autotrophic CO2 fixation pathway in Acidianus brierleyi, a facultatively anaerobic thermoacidophilic archaebacterium, was investigated by measuring enzymatic activities from autotrophic, mixotrophic, and heterotrophic cultures. Contrary to the published report that the reductive tricarboxylic acid cycle operates in A. brierleyi, the enzymatic activity of ATP:citrate lyase, the key enzyme of the cycle, was not detected. Instead, activities of acetyl-CoA carboxylase and propionyl-CoA carboxylase, key enzymes of the 3-hydroxypropionate cycle, were detected only when A. brierleyi was growing autotrophically. We conclude that a modified 3-hydroxypropionate pathway operates in A. brierleyi.

Acetyl-CoA Carboxylase↗
PubMed1996

Therapeutic effect of secretin in patients with jaundice; double-blind placebo-controlled multicentric trial.

Secretin, a gastrointestinal hormone, has been shown to have a potent choleretic effect. Having already obtained some beneficial effects with secretin in patients with intrahepatic cholestasis, we sought to confirm its effects in a double-blind placebo-controlled study in patients with mild jaundice after acute or during chronic hepatitis, where total bilirubin level was in excess of 4.0 mg/dl for 3 days or more. Patients with primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC), and familiar hyperbilirubinemia were excluded from the study. Ninety-three patients were included in this analysis, but the final evaluation covered 69 of them. No statistically significant differences were found in the reduction of serum bilirubin levels between secretin and placebo groups. As a number of patients with liver cirrhosis had been included, the subjects were subdivided into one group with cholestasis in hepatitis and one with liver cirrhosis. In the subgroup of cirrhotic patients who received secretin, serum levels of AST were significantly increased compared with the placebo group. However, since the choleretic effect of secretin is unique, further studies seem to be warranted.

Adolescent↗
PubMed1996

Inhibition of oxidation of low density lipoprotein by troglitazone.

The effect of a new oral hypoglycemic agent troglitazone, (+/-)-5-[4-(6-hydroxy-2,5,7,8-tetramethylchroman-2-yl-methoxy)benz yl]-2,4-thiazolidinedione as an antioxidant against the free radical-mediated oxidation of low density lipoprotein (LDL) was studied. The oxidation of LDL gives cholesteryl ester hydroperoxide and phosphatidylcholine hydroperoxide as major primary products. Troglitazone incorporated exogenously into LDL inhibited the oxidations of LDL induced by either aqueous or lipophilic peroxyl radicals and suppressed the formation of lipid hydroperoxides efficiently. Ascorbic acid added into the aqueous phase spared both endogenous alpha-tocopherol and troglitazone in LDL. It was also found by absorption spectroscopic and electron spin resonance (ESR) studies that troglitazone reacted rapidly with a galvinoxyl radical to give a chromanoxyl radical which gives the same ESR spectrum as alpha-tocopherol. This ESR spectrum disappeared rapidly when ascorbic acid was added into the system. These results show that troglitazone acts as a potent antioxidant and protects LDL from oxidative modification.

Antioxidants↗