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Biomedical subjects

A Takada

Publications and source records attributed to A Takada.

At least 217 records · Page 12Linked to original sources
PubMed1994

Deficiency of the fourth component of complement (C4): a family case.

In this report, an apparently healthy 38-year-old woman with a remarkably low serum C4 value is described together with other family members who had moderately low serum C4. Plasma C4 typing disclosed that the proband inherited two C4B "null" haplotypes. In addition, Southern blot analysis of the C4 gene indicated that the C4A gene was partially deleted on one of these two haplotypes in the proband. We thus concluded that a de novo deletion on the inherited half-null haplotype was the likeliest cause of the low C4 level.

Adult↗
PubMed1994

The significant enhancement of fibrinolysis by calcium ion in a cell free system: the shortening of euglobulin clot lysis time by calcium ion.

We investigated the roles of calcium ion (Ca2+) on euglobulin clot lysis time (ECLT) and found that the physiological concentration of Ca2+ significantly (4-5 times) shortened ECLT. The shortening was observed at the concentration of Ca2+ higher than 1.5-2.0 mM. Other divalent cations such as Mg2+, Zn2+ or Mn2+ didn't change ECLT. Anti-tPA antibody or plasminogen activator inhibitor-1 prolonged ECLT in the absence of Ca2+, whereas they had no effect on ECLT shortened by Ca2+. C1 inactivator also had no effect. When barium absorbed plasma was employed, the shortening of ECLT by Ca2+ wasn't observed, whereas it was recovered by the readdition of barium absorbed fraction. When factor X deficient plasma was employed, the shortening of ECLT by Ca2+ was also not observed. Thus, Ca2+ enhances fibrinolysis in a cell free system by a novel pathway in which the presence of factor X is prerequisite.

Absorption↗
PubMed1994

Massive apoptosis in infantile myofibromatosis. A putative mechanism of tumor regression.

Two cases of solitary infantile myofibromatosis (IM) are presented. Solitary IM are tumors prone to spontaneous regression. Histopathologically, several tumor lobules in our IM cases had central areas of massive cell death, with nuclear pyknosis, cytoplasmic hyalinization and nuclear fragmentation but without lymphoid or neutrophilic cell infiltration. These central cell death areas consisted of about 40% in case 2 and 50% in case 1 of the entire tumor tissues, respectively. Electron microscopy revealed that the condensed nuclei and cytoplasm were fragmented into "apoptotic bodies", with or without phagocytosis by histiocytes. DNA fragmentation, as evidenced by the terminal deoxy transferase-mediated uptake of biotinylated dUTP, was identified at massive cell death areas on paraffin sections from both cases. A characteristic 180- to 190-bp nucleosomal ladder was detected in DNA obtained from the tumor cells in case 1. The collective evidence suggested that these tumors underwent a central, massive apoptosis. As massive cell death similar to that seen in the present cases has been described in other documented cases of IM, we propose that the spontaneous regression that frequently occurs with this type of tumor may be mediated by massive apoptotic cell death.

Actins↗
PubMed1994

[A national surveillance study on alcoholic liver disease in Japan (1986-1991)].

National surveillance studies on alcoholic liver disease (ALD) in Japan were performed in 1978 and 1985, by a previous Japanese study group for ALD (Takeuchi group). In the present study, a subsequent nationwide surveillance study was performed from 1986 to 1991 and the results were compared with the previous two studies. In order to clarify the etiological relationships between hepatitis C virus (HCV) infection and ALD, an analysis was also done according to the new diagnostic criteria of ALD which was proposed by this group (Takada group). By the criteria of the Takeuchi group, the incidence of ALD was not significantly different during 1986 to 1991. However, the incidence of hepatocellular carcinoma (HCC) in alcoholic cirrhosis (AL-LC) clearly increased during this period. The analysis including the results of the previous study indicate that incidence of ALD reached a plateau in 1980 and then features of ALD in Japan entered a stable stage. However, HCC in AL-LC continued to show a linear increase from 1976 to 1991. Analysis with the new criteria of the Takada group was done in cases of 1990 and 1991. Approximately 2 out of 3 cases of ALD were caused by alcohol alone, and the remaining cases were caused by a combination of alcohol and HCV. Cases caused only by HCV were very rare. The main etiology in patients with alcoholic hepatitis and fibrosis was alcohol alone and that in chronic hepatitis of heavy drinkers was a combination of alcohol and HCV. In half of the patients with AL-LC, the etiology was alcohol alone and in the other half patients, it was a combination of both factors. In most patients with HCC, the etiology was a combination of alcohol and HCV, indicating that HCV infection may be important for the development of HCC in alcoholics.

Carcinoma, Hepatocellular↗
PubMed1994

Hepatic messenger RNA contents of cytochrome P4502E1 in patients with different P4502E1 genotypes.

Since heavy drinkers do not always develop alcoholic liver disease (ALD), genetic factors may be involved. Cytochrome P4502E1 (P4502E1) is the main enzyme that oxidizes ethanol in the non-alcohol dehydrogenase pathway. Recently, the presence of genetic polymorphisms at the 5'-flanking region of this enzyme was confirmed. We recently detected the c2 gene of P4502E1 in most patients with ALD, suggesting that development of ALD may be genetically controlled. Although high transcriptional activity of the c2 gene was confirmed in studies using the Hep G2 cell, little is known about transcriptional activity in humans with the c2 gene. Therefore, messenger RNA (mRNA) contents of P4502E1 in livers of patients with different P4502E1 genotypes were measured. Hepatic mRNA contents in type B were three times higher than in type A, suggesting that transcriptional activity of the c2 gene of P4502E1 is stronger than that of the c1 gene, even in human liver. The results of the present study are compatible with those in the Hep G2 cells. These results suggest that polymorphisms of the P4502E1 gene may be linked to the development of ALD through enhancement of ethanol metabolism in the non-alcohol dehydrogenase pathway.

Cytochrome P-450 CYP2E1↗
PubMed1993

A distinct type of sialyl Lewis X antigen defined by a novel monoclonal antibody is selectively expressed on helper memory T cells.

A subset of human helper memory T cells is known to adhere to E-selectin expressed on cytokine-activated endothelial cells. However, sialyl Lex antigen, the carbohydrate ligand for E-selectin, has been hardly detectable on these cells, at least when typical anti-sialyl Lex antibodies were used for detection. One of the MoAbs (2F3, IgM), which we raised against a chemically synthesized sialyl Lex glycolipid preparation, is found to react selectively to CD4+ CD45RObright+ CD45RA- helper memory T cells among peripheral lymphocytes in healthy individuals. The specificity of the antibody is in clear contrast to that of the hitherto reported typical anti-sialyl Lex antibodies FH-6 and SNH-3. These classical anti-sialyl Lex antibodies were known to react to a subset of natural killer (NK) cells, but were not reactive with any particular subset of resting peripheral T or B cells of healthy individuals if the cells were not activated. On the other hand, the newly generated 2F3 antibody specifically reacted to helper memory T cells, and did not react to NK cells, B cells, or any T cells other than helper memory T cells. When tested against the sialyl Lex-active glycolipid antigen, the reactivity of 2F3 was not significantly different from that of the classical anti-sialyl Lex antibodies. But when tested against oligosaccharides prepared from cellular glycoproteins, 2F3 detected a distinct set of O-linked oligosaccharides, which were not reactive to the classical anti-sialyl Lex antibodies. Our results suggest that various molecular species of sialyl Lex antigens are present on carbohydrate side chains of cellular glycoproteins, and that helper memory T cells express a distinct type of sialyl Lex antigen that is defined by 2F3 but is not efficiently detected by other typical anti-sialyl Lex antibodies. Among cultured lymphocytic leukemia cells, the adult T-cell leukemia (ATL) cells preferentially expressed the 2F3-defined antigen, and acute lymphocytic leukemia cells rarely expressed the antigen. The cultured ATL cells expressing the 2F3-defined antigen showed a clear E-selectin-dependent adhesion to cytokin-activated endothelial cells, and the 2F3-defined sialyl Lex antigen served as a ligand for E-selectin as ascertained by the clear inhibition of adhesion with the 2F3 antibody.(ABSTRACT TRUNCATED AT 400 WORDS)

Antibodies, Monoclonal↗
PubMed1993

Changes in fibrinolytic parameters in male patients with type 2 (non-insulin-dependent) diabetes mellitus.

We examined changes in fibrinolytic parameters in male patients with diabetes mellitus (DM) and controls. DM patients were divided into three groups: patients without retinopathy, patients with simple retinopathy, and patients with proliferative retinopathy. Plasma levels of t-PA (tissue plasminogen activator) and t-PA-PAI-1 (plasminogen activator inhibitor-1) complex increased with increase in age, but those of PAI-1 (total and free) did not change in controls. On the other hand plasma levels of PAI-1 decreased with increase in age in DM patients. Plasma levels of t-PA, t-PA-PAI-1 complex, free and total PAI-1 increased with increase in body mass index in controls, but no significant changes were shown in these parameters in DM patients. When compared with controls, plasma levels of t-PA, t-PA-PAI-1 complex and PAI-1 were lower in DM patients. Plasma levels of UK (urokinase) and Lp(a) were higher in DM patients. ELT (euglobulin clot lysis time) was significantly shorter in DM patients than in controls. Patients without retinopathy showed increased fibrinolytic activities compared with those with retinopathy due to the increased levels of t-PA in plasma. These results seem to indicate that blood vessels release larger amounts of t-PA at the early stage of DM, then release being impaired at its advance stage. It is also suggested that the regulatory control mechanisms of fibrinolytic activity associated with mechanisms of fibrinolytic activity associated with change in age and body mass index are different between patients with DM and normal people.

Adult↗
PubMed1993

The potential role of platelet PAl-1 in t-PA mediated clot lysis of platelet rich plasma.

The potential role of platelets in platelet rich plasma clot lysis induced by tissue plasminogen activator (t-PA) was investigated. At the various concentrations of both single chain t-PA (sct-PA) and two chain t-PA (tct-PA) (1.5nM, 3nM, and 6nM), we compared the t-PA mediated lysis time of platelet rich plasma clot (PRP-clot) with that of platelet poor plasma clot (PPP-clot). At the concentrations ranged from 1.5 to 6 nM of both types of t-PA, the clot lysis time of PRP-clot was longer than that of PPP-clot. This elongation was more significant in the tct-PA induced clot lysis than that in the sct-PA induced clot lysis. At the concentration of 3nM of tct-PA, the lysis time of PRP-clot was longer by a factor of 30% in comparison with that of PPP-clot. When the release and the aggregation of platelets were blocked by prostaglandin E1 (PGE1) and theophylline in this experiment, the lysis time of PRP-clot was essentially the same as that of PPP-clot. We then measured the antigen levels of total PAI-1 and t-PA-PAI-1 complex in the lyzed solutions of PRP-clot and PPP-clot to analyse the possible effect of plasminogen activator inhibitor-1 (PAI-1) present in platelets. Most of PAI-1 in a PPP-clot lyzed sample existed as t-PA-PAI-1 complex. In the lyzed solution of PRP-clot, however, the antigen levels of both total PAI-1 and t-PA-PAI-1 complex were significantly higher than those in PPP-clot, and larger amounts of PAI-1 existed as free PAI-1 which possesses activity. These data suggest that at least certain amounts of PAI-1 in platelets exist as an active form and inhibits t-PA activity resulting in the prolongation of the clot lysis time. Activation of platelets, therefore, seems to play an important role in the platelet rich plasma clot lysis induced by t-PA.

Alprostadil↗
PubMed1993

Specific expression of a complex sialyl Lewis X antigen on high endothelial venules of human lymph nodes: possible candidate for L-selectin ligand.

L-selectin is a cell adhesion molecule that mediates homing of lymphocytes to the peripheral lymph nodes and is speculated to bind to the carbohydrate determinant which is specifically expressed by the endothelial cells of high endothelial venules (HEVs) in the peripheral lymph nodes. One of the murine monoclonal antibodies (2H5, IgM, kappa), which was raised against sialyl LeX-active glycolipids which have long and complicated carbohydrate structures, was found to react strongly to the HEV endothelial cells of the human peripheral lymph nodes, while the typical anti-sialyl LeX antibodies SNH-3, FH-6 and CSLEX-1 failed to detect the antigen on HEV under the same condition. This new antibody was reactive to essentially all endothelial cells of HEV in the peripheral lymph nodes, and moderately to some endothelial cells in Payer's patches and appendices, but never reacted with the endothelial cells of post capillary venules in the spleen, thymus, or other organs. The 2H5 antibody detected three major glycoproteins of 90, 110 and 250 kDa, the most abundant molecular species being 110 kDa, in the stroma of human lymph nodes. In Stamper-Woodruff assays employing cryostat sections of human lymph nodes, the 2H5 antibody significantly inhibited the adhesion of peripheral lymphocytes to the endothelial cells of HEV. These results indicate that the carbohydrate antigens defined by the 2H5 antibody, most probably sialyl LeX determinants having complex carbohydrate structures, serve as the ligand for L-selectin on HEV endothelial cells.

Antibodies, Monoclonal↗
PubMed1993

The effect of MCI-9042 on serotonin-induced platelet aggregation in type 2 diabetes mellitus.

MCI-9042, a potent inhibitor of 5HT2 receptor, was used to examine its effects on serotonin induced-aggregation of platelets obtained from patients with type 2 diabetes mellitus (DM). The extent of platelet aggregation induced by serotonin increased in DM patients without retinopathy, but the increase was further significant in DM patients with retinopathy. MCI-9042 as well as ketanserin, inhibited significantly serotonin induced-aggregation of platelets obtained from DM patients with retinopathy. MCI-9042 dose dependently inhibited platelet aggregation induced by serotonin and collagen. These results suggest that serotonin which may be released from platelets of DM patients may activate platelets together with collagen exposed on atherosclerotic endothelium and that MCI-9042 may be inhibitory to enhanced platelet aggregability under these conditions.

Adult↗
PubMed1993

Conformational change of plasminogen: effects of N-terminal peptides of Glu-plasminogen.

Seven peptides were synthesized to analyze the mechanism of the intramolecular binding of the N-terminal peptide of Glu-plasminogen (Glu-plg) to its kringles. They were Ala44-Lys50, Ala44-Glu51, Ala44-Ser49, Val17-Gly23, Lys19-Gly23, Lys19-Gln21 and Lys19-Lys20. Ala44-Lys50, Ala44-Glu51 and Lys19-Lys20.enhanced the activation of Glu-plg by tissue plasminogen activator (t-PA) or urinary plasminogen activator (u-PA). The activation of Lys-plg, however, was not influenced by these peptides. Therefore, it is suggested that these three peptides worked on Glu-plg in a similar manner as lysine analogue by making the conformation of Glu-plg looser. These peptides did not have any direct effects on u-PA and t-PA. Concerning the effect on fibrinolysis Ala44-Lys50 and Lys19-Lys20 prolonged euglobulin clot lysis time. These results indicate that Ala44-Glu51 may be a responsible binding site in the N-terminal portion of Glu-plg, and LBS of kringle 1 or 4 is the binding site of N-terminal portion of Glu-plg.

Amino Acid Sequence↗
PubMed1993

Impaired fibrinolytic activity induced by ingestion of butter: effect of increased plasma lipids on the fibrinolytic activity.

To investigate the effects of the increased plasma lipid level on fibrinolysis, we measured the levels of fibrinolytic components in serially obtained plasma samples from healthy volunteers after the intake of different amounts of butter. Plasma triglyceride level increased significantly after butter intake compared to the control group. Eight hours after the intake of 100g of butter, plasminogen activator inhibitor 1 (PAI-1) level in plasma was significantly higher and euglobulin clot lysis time was significantly prolonged compared to those of the control group. There was no effect on plasma tissue plasminogen activator level. These results suggest that the temporary increase in plasma triglyceride level induced high PAI-1 level, resulting in impaired fibrinolytic activity. The effect of temporary hyperlipidemia on platelet function was also analyzed and revealed that the response of platelets to ADP and collagen was lower in the butter intake group compared to those of the control.

Adolescent↗
PubMed1993

Dissociation of alpha 2-plasmin-inhibitor-plasmin complex and regeneration of plasmin activity by SDS treatment.

In order to understand the mechanism for the complex between alpha 2-plasmin-inhibitor (alpha 2-PI) and plasmin to express its specific activity on fibrin autography after SDS-PAGE, we analyzed the effects of SDS on alpha 2-PI molecule and alpha 2-PI-plasmin complex. Treatment of alpha 2-PI by SDS at the concentrations of 0.01% and 0.1% abolished the activity of alpha 2-PI to form a stoichiometric complex with plasmin, whereas it did not interfere with plasmin's activity. More interestingly, in the case of 0.01% SDS, alpha 2-PI was further cleaved to a smaller molecule. Treatment of previously formed alpha 2-PI-plasmin complex by SDS at the concentrations of both 0.01% and 0.1% dissociated the complex and expressed specific amidolytic activity against tripeptide substrate (S-2251), which activity was totally quenched by aprotinin. When alpha 2-PI-plasmin complex was treated by higher concentration of SDS for 12 hours, dissociated free plasmin's band could be observed on SDS-PAGE analysis. It is likely, therefore, that the exposure of alpha 2-PI-plasmin complex to SDS during the procedure of SDS-PAGE dissociates the complex and expresses its specific proteolytic activity in fibrin autography. These features of alpha 2-PI and its complex with plasmin are similar to those of plasminogen activator inhibitor type 1 (PAI-1) and its complex with plasminogen activators (PAs), thus they may represent some common features of the SERPINS.

Antifibrinolytic Agents↗
PubMed1993

Contribution of carbohydrate antigens sialyl Lewis A and sialyl Lewis X to adhesion of human cancer cells to vascular endothelium.

The carbohydrate antigen, sialyl Lex, is known to be a ligand for the cell adhesion molecule called ELAM-1 (E-selectin, endothelial cell leukocyte adhesion molecule-1), which is present on cytokine-activated human endothelial cells. Recently, we reported that another carbohydrate antigen, sialyl Lea, can also serve as a ligand for ELAM-1 (A. Takada, K. Ohmori, N. Takahashi, K. Tsuyuoka, K. Yago, K. Zenita, A. Hasegawa, and R. Kannagi, Biochem. Biophys. Res. Commun., 179: 713-719, 1991). Both sialyl Lex and sialyl Lea are expressed in many human malignant cells. In order to assess the contribution of these carbohydrate antigens to the adhesion of human malignant cells to vascular endothelium, we selected a panel of 12 cultured human epithelial cancer cell lines and a panel of 12 human leukemia cell lines which express sialyl Lex and/or sialyl Lea antigens. All 12 epithelial cancer cell lines exhibited a clearly ELAM-1-dependent adhesion to cytokine-activated human umbilical vein endothelial cells, while only 3 of the 12 leukemia cell lines exhibited significant participation of ELAM-1 in the adhesion. With regard to epithelial cancer cells, the adhesion of 6 cancer cell lines, mostly of colon and pancreas origin, was dependent almost exclusively on sialyl Lea. A significant contribution of the sialyl Lex antigen was noted in the adhesion of the other 6 cell lines, including cancers of lung and liver origin. These results imply that the sialyl Lea/ELAM-1 adhesion system, as well as the sialyl Lex/ELAM-1 adhesion system, plays an important role in the adhesion of human cancer cells to human umbilical vein endothelial cells. With regard to leukemia cells, on the other hand, adhesion of the 3 leukemia cell lines that showed ELAM-1-dependent adhesion was mediated by the sialyl Lex antigen, and none of these leukemia cell lines expressed sialyl Lea or exhibited sialyl Lea-dependent adhesion.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1993

Differentiation-dependent expression of sialyl stage-specific embryonic antigen-1 and I-antigens on human lymphoid cells and its implications for carbohydrate-mediated adhesion to vascular endothelium.

Expression of two developmentally regulated carbohydrate antigens, the sialyl stage-specific embryonic antigen-1 (SSEA-1) and I-antigens, in human lymphocytes and lymphocytic leukemia cells was investigated using specific monoclonal antibodies. Sialyl SSEA-1 was expressed only on natural killer (NK) cells, and was essentially absent on resting mature T and B cells among normal peripheral lymphocytes. On the other hand, the I-antigen was strongly expressed on virtually all mature B cells, moderately expressed on most mature T cells, but not expressed on NK cells in normal donors. Expression of the two antigens on normal T and B cells was reversible; in vitro stimulation of normal lymphocytes with concanavalin A (Con A) resulted in the loss of I-antigen and appearance of sialyl SSEA-1 on CD3+ T blasts, whereas stimulation with pokeweed mitogen led to loss of I-antigen expression and appearance of sialyl SSEA-1 antigen on CD19+ B blasts. Among lymphocytic leukemia cells, sialyl SSEA-1 was detected primarily on leukemia cells having immature properties such as most common acute lymphocytic leukemia (cALL) blasts, while the I-antigen was frequently expressed on malignant cells having relatively mature properties, such as those found in adult T-cell leukemia or chronic lymphocytic leukemia, and only occasionally on cALL blasts. Among normal peripheral lymphocytes, the sialyl SSEA-1+I-antigen- NK cells selectively underwent E-selectin (ELAM-1, endothelial-leukocyte adhesion molecule-1)-dependent adhesion to endothelial cells, while the I-antigen+sialyl SSEA-1- mature T and B cells did not, in line with the recent finding that sialyl SSEA-1 serves as a specific ligand for E-selectin. Con A blasts, which are sialyl SSEA-1+I-antigen-, also exhibited significant E-selectin-dependent adhesion to endothelial cells. These results indicate that expression of the sialyl SSEA-1 and I-antigens varies alternately depending on the differentiation/activation status of the lymphocytes, and that this at least partly regulates the behavior of lymphocytes at the vessel wall.

Antibodies, Monoclonal↗
PubMed1993

Characteristic features of alcoholic liver disease in Japan: a review.

The characteristics of alcoholic liver disease (ALD) in Japanese patients were reviewed and compared with those in Western countries. From the study in Japanese cases, it became clear that alcoholic fibrosis and chronic hepatitis induced by alcohol were types of ALD other than the traditional 3 types. Liver injury in Japanese cases was clearly milder than that in American cases. In American cases, the injury may be fully developed, because of greater alcohol and fat intake. This may be one reason why the two above types of ALD have not been mentioned in the literature of Western countries. In Japanese patients, hepatitis C virus (HCV) infection is not related to alcoholic fibrosis and alcoholic hepatitis. On the other hand, the prevalence of HCV markers was high in chronic hepatitis, cirrhosis and hepatocellular carcinoma (HCC) patients. Alcoholic hepatitis and chronic hepatitis are the high risk groups for the development of cirrhosis and the chronic hepatitis group is at high risk for the development of HCC. Although the risk is low in alcoholic fibrosis, some patients also develop cirrhosis. About half of the cases of cirrhosis may develop from alcoholic hepatitis and alcoholic fibrosis, and the remaining half cases may develop from chronic hepatitis. Over 80% of HCC cases may develop from chronic hepatitis in Japan. Chronic alcoholism enhanced the development of HCV-related HCC. Recent increase of HCC in alcoholic cirrhosis in Japan may be related to the increase of alcohol consumption, the increase of blood transfusions, and longer survival of cirrhosis patients.

Hepatitis, Alcoholic↗
PubMed1993

Effects of genotypes of hepatitis C virus on interferon treatment for chronic type C hepatitis.

Interferon is commonly used for treatment of type C hepatitis, but the effects are variable and many factors may be responsible. Hepatitis C virus (HCV) can be classified into 4 types, PT, K1, K2a and K2b. Therefore, the responses to interferon treatment in patients with the different HCV genotypes were analyzed. Twenty-four patients with type C hepatitis were treated with 3 to 10 million units of various types of interferon for more than 8 weeks. HCV-RNA encoding the NS5 region (HCV-NS5) was positive in these 24 patients, 16 of which were classified with the K1 type and 8 with the K2 type of HCV. In all patients except for 2, HCV-NS5 became negative within 3 weeks of treatment without relation to the HCV genotypes. Serum alanine aminotransferase levels were normalized in 7 out of 8 patients in the K2 group and in 4 out of 16 patients in the K1 group at the end of 8 weeks. At the 24th week, ALT levels were normalized in 5 out of 6 patients in the K2 group, and in one out of 9 patients in the K1 group. The percentage of patients exhibiting a good response was significantly higher in the K2 group than in the K1 group at both observation periods. During the post-treatment periods, relapse following complete response was found in 3 patients in the K2 group and in one patient in the K1 group. The final effects of interferon were significantly better in the K2 group than in the K1 group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗