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Biomedical subjects

H Asakura

Publications and source records attributed to H Asakura.

At least 199 records · Page 11Linked to original sources
PubMed1997

[Non-surgical therapy for ulcerative colitis].

Ulcerative colitis involving primarily the mucosa of the colon and rectum is a diffuse and nonspecific inflammatory disease. Immunocompetent cells infiltrating in the inflammed mucosa are mainly lymphocytes, macrophages and neutrophils. These activated cells produce proinflammatory cytokines such as IL-1, IL-6, IL-8 and TNF alpha and inflammatory activators such as PAF, leukotriene, prostaglandins, free radicals and proteases, resulting in acute on chronic states. Non-surgical therapy for ulcerative colitis includes basic medical therapy with sulfasulphapyridine, 5-ASA, corticosteroids and immune suppressive drugs as well as new therapies, which are leukocytapheresis, granulocytapheresis, anticytokine therapy with antiTNF alpha monoclonal antibody, IL-1ra and IL-10, intravenous treatment of massive immunoglobulins and transdermal nicotine therapy.

Colitis, Ulcerative↗
PubMed1996

A novel activity of HMG domains: promotion of the triple-stranded complex formation between DNA containing (GGA/TCC)11 and d(GGA)11 oligonucleotides.

The high mobility group protein (HMG)-box is a DNA-binding domain found in many proteins that bind preferentially to DNA of irregular structures in a sequence-independent manner and can bend the DNA. We show here that GST-fusion proteins of HMG domains from HMG1 and HMG2 promote a triple-stranded complex formation between DNA containing the (GGA/TCC)11 repeat and oligonucleotides of d(GGA)11 probably due to G:G base pairing. The activity is to reduce association time and requirements of Mg2+ and oligonucleotide concentrations. The HMG box of SRY, the protein determining male-sex differentiation, also has the activity, suggesting that it is not restricted to the HMG-box domains derived from HMG1/2 but is common to those from other members of the HMG-box family of proteins. Interestingly, the box-AB and box-B of HMG1 bend DNA containing the repeat, but SRY fails to bend in a circularization assay. The difference suggests that the two activities of association-promotion and DNA bending are distinct. These results suggest that the HMG-box domain has a novel activity of promoting the association between GGA repeats which might be involved in higher-order architecture of chromatin.

Base Composition↗
PubMed1996

Clinical significance of simultaneous determinations of alpha-fetoprotein and des-gamma-carboxy prothrombin in monitoring recurrence in patients with hepatocellular carcinoma.

BACKGROUND: Measurements of serum alpha-fetoprotein (AFP) concentration and plasma concentration of des-gamma-carboxy prothrombin (DCP) have been widely used for the early diagnosis of hepatocellular carcinoma (HCC). The two markers generally run parallel to each other. However, in our study, they sometimes fluctuated independently in response to tumor regression or recurrence. METHODS: A longitudinal series of concentrations of serum AFP and plasma DCP were determined simultaneously for 245 patients with HCC from the time of diagnosis to tumor recurrence after treatment. RESULTS: Positive reactions for AFP were noted in 168 patients (69%) and for DCP in 126 patients (51%). One hundred and ten of 245 patients with HCC (45%) were positive for both AFP and DCP. In 35 patients (14%), these 2 tumor markers fluctuated independently in response to tumor regression and recurrence. These patients were categorized into four groups as follows: Group 1 had elevated AFP only at diagnosis; it then decreased after treatment, but DCP was elevated at the time of tumor recurrence without AFP elevation (3 patients); Group 2 had elevated DCP at diagnosis and elevated AFP at tumor recurrence (4 patients); Group 3 had elevated AFP and DCP at diagnosis, but only AFP (8 patients) or DCP (7 patients) was elevated at tumor recurrence; Group 4 had only elevated AFP (2 patients) or DCP (11 patients) at diagnosis, but both AFP and DCP were elevated at tumor recurrence. CONCLUSIONS: The results of this study indicate that simultaneous determinations of AFP and DCP are useful for monitoring recurrence in patients with HCC after treatment, and that the decrease to normal levels of a single marker does not always indicate the absence of tumor recurrence.

Adolescent↗
PubMed1996

A novel clonality assay for the mouse: application to hepatocellular carcinomas induced with diethylnitrosamine.

A polymerase chain reaction-based clonality assay was developed for mouse tumors and cellular proliferations of the mouse. This assay was based on a polymorphism of the phosphoglucokinase-1 (Pgk-1) gene on the X chromosome between two different mouse subspecies and the different methylation patterns of active and inactive X chromosomes. All 15 tumor cell lines examined showed one of the two allelic bands on gel electrophoresis, which is consistent with the theory that tumor cell lines are monoclonally derived. This suggests that the Pgk-1 system is useful for clonality studies that will give insight into cancer development. With this method, nine hepatocellular carcinomas were examined, and eight showed monoallelic patterns. The remaining tumor exhibited a biallelic pattern, which is suggestive of polyclonal origin; however, other possibilities are discussed.

Animals↗
PubMed1996

Existence of a small population of IL-2R beta hi TCRint cells in SCG and MRL-lpr/lpr mice which produce normal Fas mRNA and Fas molecules from the lpr gene.

Mice carrying the lpr gene, SCG and MRL-lpr/lpr mice, were used to characterize the phenotype and lpr gene of abnormally proliferating T cells in these mice. A major population which expanded in these mice were T cells expressing intermediate (int) levels of T cell receptor (TCR) (and CD3) and the phenotype of interleukin-2 receptor (IL-2R) beta lo alpha- (possibly abnormal TCRint cells). The levels of TCRhi cells of thymic origin (generated through the mainstream of T cell differentiation in the thymus) profoundly decreased after the onset of disease. However, a small population of normal TCRint cells (i.e. IL-2R beta hi alpha-) were also found to exist in all tested organs. For example, the majority of abnormal IL-2R beta lo TCRint cells were CD4-8- CD2-, while normal IL-2R beta hi TCRint cells were a mixture of single-positive cells (mainly CD8+), CD4-8- cells and CD2+ cells. Moreover, normal TCRint cells preferentially produced normal Fas mRNA and Fas molecules from the lpr gene. This phenomenon explains the leaky appearance of normal Fas mRNA and Fas molecules in mice carrying the lpr gene. It is suggested that a small population of IL-2R beta hi TCRint cells are resistant to the lpr genetic abnormality.

Animals↗
PubMed1996

Intraepithelial lymphocytes in colon have similar properties to intraepithelial lymphocytes in small intestine and hepatic intermediate TCR cells.

Recently, properties of intraepithelial lymphocytes (IEL) in the colon (C-IEL) have been analyzed in comparison with those of IEL in the small intestine (SI-IEL). We compared the properties of C-IEL with those of SI-IEL and hepatic intermediate TCR cells, two other types of extrathymic T cells. C-IEL and intermediate TCR cells contain many NK1+T cells, although SI-IEL contain few. V gamma and V delta usage of C-IEL was the same as that SI-IEL, and that of intermediate TCR cells was different. C-IEL responded to Con A while SI-IEL did not. As to adhesion molecules, C-IEL include both extrathymic and thymus-originated type T cells. With age, TCR- alpha beta(+) CD4+ CD8+ cells do not increase among C-IEL but do increase among SI-IEL. IL-2R beta(+) or CD4- CD8- C-IEL increase as observed in the liver. These results indicate that these organ-specific T cells have different roles at their respective sites and that they may be of different lineages.

Animals↗
PubMed1996

Hypercoagulability and high lipoprotein(a) levels in patients with type II diabetes mellitus.

Diabetes mellitus is associated with disturbances in hemostasis that could contribute to the development of diabetic vascular disease. We investigated the changes in parameters of blood coagulation and the fibrinolytic system and in plasma levels of lipoprotein(a)(Lp(a)) in 124 patients with type II diabetes mellitus and 44 healthy control subjects matched for age and body mass index (BMI) to determine whether hemostatic disturbances may lead to increased cardiovascular mortality. Median levels of fibrinogen (P < 0.0001), thrombin-antithrombin III complex (TAT) (P < 0.005), and plasminogen activator inhibitor-1 (PAI-1) activity (P < 0.05) in plasma were significantly elevated in diabetic patients compared with controls. The median concentration of Lp(a) was significantly higher in diabetic patients than in normal controls (18.2 vs. 12.6 mg/dl. P < 0.0005). Lp(a) levels tended to be elevated in patients with a prolonged history of diabetes. There was no evidence that Lp(a) levels were affected by metabolic control or by type of treatment. Twenty-two diabetics with coronary heart disease (CHD) had significantly higher levels of fibrinogen (P < 0.05), TAT (P < 0.05), and Lp(a) (24.7 vs. 13.7 mg/dl, P < 0.01) than the 51 patients without diabetic angiopathy. Our data indicate that impaired hemostatic balance in diabetes may cause hypercoagulability and may thus contribute to the increased cardiovascular mortality in diabetes.

Aged↗
PubMed1996

Rectification of diabetic state in C57BL/KsJ-db/db mice by the implantation of pancreatic beta cell line MIN6.

C57BL/KsJ mice carrying homozygous db/db mutation (db/db mice) are characterized by extreme obesity and early onset of hyperglycemia. In an attempt to rectify diabetes of these mice, a pancreatic beta cell line MIN6, which retains glucose-inducible insulin secretion, was transplanted subcutaneously into the back of the mice. Glucose and insulin levels of individual mice were examined biweekly and their weight gain weekly. All mice were sacrificed at 100 days after the transplantation of MIN6 cells. In db/db mice that had received MIN6 cells, blood insulin levels were restored and blood glucose levels were reduced to those of non-diabetic mice, although they remained obese. Glucose tolerance test suggested that transplanted MIN6 cells responded to loaded glucose as beta cells of non-diabetic mice. Immunohistochemical study showed that transplanted MIN6 cells produced insulin. Fatty liver associated with diabetes mellitus observed in db/db mice was not found in the MIN6 cell-transplanted mice. Implication of the results is discussed with reference to potential therapies for severe diabetes.

Animals↗
PubMed1996

Effect of K-ras mutation on morphogenesis of colorectal adenomas and early cancers: relationship to distribution of proliferating cells.

The authors evaluated the association of the K-ras mutation with the distribution of proliferating cells and the macroscopic appearance of colorectal tumors. A total of 122 colorectal adenomas and 96 early cancers were classified macroscopically as follows: (1) polypoid, exceeding 3 mm in height; (2) flat or hemispherically elevated 3 mm or less; and (3) depressed. The intramucosal areas of these tumors were examined by Ki-67 immunostaining and nested polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to detect proliferating cells and the K-ras codon 12 mutation. The distribution pattern of the Ki-67-positive cells was of two types: diffuse (D), being positive throughout the crypts, and superficial (S), being positive mainly in the superficial areas of the crypts. The K-ras mutation and the D type distribution of the Ki-67-positive cells were significantly less common (P < .005) in the nonpolypoid, depressed, or elevated tumors versus the polypoid tumors. The incidence of the K-ras mutation was significantly (P < .0001) associated with the D type distribution. The K-ras mutation may involve a disorder of cell proliferation that leads to the polypoid growth of colorectal tumors.

Adenocarcinoma↗
PubMed1996

Protective effects of DX-9065a, an orally active, novel synthesized and selective inhibitor of factor Xa, against thromboplastin-induced experimental disseminated intravascular coagulation in rats.

We investigated the protective effects of DX-9065a, an orally active, newly synthesized, and specific inhibitor of factor Xa, against experimental disseminated intravascular coagulation (DIC) in rats. Experimental DIC was induced by a 4 hour sustained infusion of thromboplastin at a dose of 2.5 mg/kg. The rats were orally administered DX-9065a at 10, 30, 100 mg/kg 30 minutes before thromboplastin injection. In this DIC model, DX-9065a showed a protective effect against DIC, at all doses and in all parameters, including fibrin(ogen) degradation products, fibrinogen level, thrombin-antithrombin III complex level, prothrombin time (PT), activated partial thromboplastin time (APTT), platelet count, and the number of renal glomeruli with fibrin thrombi. When DX-9065a was orally administered at 100 mg/kg without thromboplastin, no significant changes were seen in hemostatic parameters except PT and APTT, and no fibrin thrombi or abnormal bleeding were seen in renal specimens. These findings suggested that the new oral anti-Xa drug, DX-9065a, has a protective effect against thromboplastin-induced DIC model with little risk of bleeding.

Administration, Oral↗
PubMed1996

Hypercoagulability and high lipoprotein(a) levels in patients with aplastic anemia receiving cyclosporine.

There is some clinical evidence that cyclosporine A (CyA) is associated with thrombotic complications of bone marrow and renal transplantation. We investigated plasma concentrations of lipoprotein(a) [Lp(a)], a potentially atherothrombotic lipoprotein, and hemostatic and vascular status in ten patients with aplastic anemia receiving CyA, eleven patients not taking it, and 38 age-matched healthy controls. Patients receiving CyA had significantly higher concentrations of plasma fibrinogen (P < 0.05), prothrombin fragment 1 + 2 (F1 + 2; P < 0.05), plasminogen activator inhibitor-1 (PAI-1; P < 0.05), and von Willebrand factor antigen (P < 0.05) than did patients not taking CyA. Plasma concentrations of Lp(a) were higher in CyA-treated patients than those not receiving it (P < 0.05) or healthy controls (P < 0.05). The difference in the Lp(a) concentration between controls and patients who did not receive CyA-treatment was not significant. Our results suggest that hypercoagulability is likely to occur during CyA therapy. Further, the presence of high concentrations of Lp(a) may accelerate the process of atherosclerosis and increase thrombotic events in patients receiving long-term CyA.

Adult↗
PubMed1996

Microheterogeneity of serum transferrin in the diagnosis of hepatocellular carcinoma.

Heterogeneous reactivity of human serum transferrin (Tf) with lectins was analysed using patient sera to determine whether it can be used to distinguish patients with hepatocellular carcinoma (HCC) from those with liver cirrhosis (LC). Microheterogeneity of Tf was analysed by crossed immunoaffinity electrophoresis (CIAE) with concanavalin A (Con A) and Lens culinaris agglutinin (LCA). Sample sera from 58 patients with HCC, 43 patients with LC and 10 normal controls were used in this study and the results were evaluated statistically. The increments of Con A-non-reactive (C1) and -weakly reactive (C2) species of Tf were observed in HCC compared with those of LC and Norm. Significant increase in the combined percentage of Con A- C1 + C2 species was also revealed in HCC (35.5 +/- 8.5%, mean+/-s.d.) compared with those of LC (29.1 +/- 6.8%; P < 0.001) and normal controls (17.1 +/- 2.3%; P < 0.001). The elevation of LCA-reactive (L2) species of Tf was recognized in HCC (8.2 +/- 3.8%) in comparison with those of LC (4.8 +/- 3.1%; P < 0.001) and normal controls (1.3 +/- 1.7%; P < 0.001). The increment of C1 + C2 species and/or L2 species of Tf was observed in 78% (sensitivity) of patients with HCC. The specificity, the positive predictive value and the overall accuracy were 81, 88 and 72%, respectively. Positive ratio of C1 + C2 and/or L2 species was 77 and 70% in alpha-fetoprotein low and -high producing HCC patients, respectively. These results indicate that the microheterogeneity analysis of human serum Tf is useful for distinguishing patients with HCC from those with LC and normal controls.

Aged↗
PubMed1996

Localization of hyaluronan in human liver sinusoids: a histochemical study using hyaluronan-binding protein.

Circulating hyaluronan is mostly derived from lymph, fibroblast and Ito cells in the liver, and more than 90% of hyaluronan is degraded in hepatic sinusoidal endothelial cells. Thus, elevated serum hyaluronan is regarded as an indication of hepatic fibrosis with activated Ito cells and dysfunctional sinusoidal endothelial cells. We studied the distribution of hyaluronan in human liver sinusoids to determine the influences on elevated hyaluronan levels in sera. Histochemical examination was made using hyaluronan-binding protein (HABP) and serial sections of liver tissue for staining of alpha-smooth muscle actin (ASMA) (an indicator of activated Ito cells) and of ulex europaeus agglutinin I lectin (UEA-1) (closely related to hepatic sinusoidal capillarization). Positive staining, indicating the presence of hyaluronan, was noted in fibrous regions around the portal tracts, areas of focal necrosis in the liver parenchyma, and walls of the sinusoids in chronic hepatitis. In this group, hyaluronan-positive areas corresponded to positive ASMA staining and faint staining of UEA-1. On the contrary, in liver cirrhosis, UEA-1-positive areas were essentially identical to hyaluronan-positive areas and to ASMA-negative areas in sinusoidal walls. Hyaluronan and ASMA could be detected in the same areas of sinusoidal walls in chronic hepatitis, but not in liver cirrhosis. Hyaluronan appears to be mainly related to the staining of activated Ito cells in chronic hepatitis. Therefore, we concluded that in chronic hepatitis, the production of hyaluronan was accelerated in Ito cells; however, degradation of hyaluronan by sinusoidal endothelial cells continued. On the contrary, in liver cirrhosis, hyaluronan production decreased in Ito cells, and a marked transformation of sinusoidal endothelial cells with hepatic sinusoidal capillarization indicated loss of the ability to degrade hyaluronan. These different mechanisms in chronic hepatitis and liver cirrhosis may operate in the sinusoidal walls and may cause the elevation of hyaluronan in sera.

Biomarkers↗
PubMed1996

Alpha-fetoprotein-producing renal cell carcinoma with increased activity of N-acetylglucosaminyl-transferase III.

N-acetylglucosaminyltransferase (GnT) III catalyzes the addition of N-acetylglucosamine through a beta 1-4 linkage to the mannose of the trimannosyl core, resulting in conversion of the concanavalin-A-(ConA)-reactive glycan into the ConA-nonreactive one. In this study, we measured GnT III levels in serum, tumor, and surrounding normal tissues together with a glucosaminylation index of alpha-fetoprotein (AFP), which is defined as the percentage of the ConA-nonreactive species in total AFP, in a case of AFP-producing renal cell carcinoma. The glucosaminylation index was determined by affinoelectrophoresis in the presence of ConA. GnT III was measured by using a pyridylaminated asialoagalactobiantennary sugar chain as a substrate by high-performance liquid chromatography. The glucosaminylation index of serum AFP, the concentration of which was 68 ng/ml, was 60%. This value is much higher than observed in hepatocellular carcinomas. The tumor tissue level of GnT III was 55.34 pmol/mg/h which was about six fold higher (9.50 pmol/mg/h) than in normal surrounding tissues. The serum level of this enzyme before surgery was 27.65 pmol/ml/h and decreased to 5.38 pmol/ml/h thereafter in association with a depression of serum AFP from 68 to 5.4 ng/ml. Thus, an increased level of GnT III in tumor tissues could account for the elevated conversion of a biantennary complex type sugar chain of AFP into a bisecting glucosaminylated biantennary one resulting from the addition of an N-acetylglucosamine residue at the trimannosyl core. This is, to our knowledge, the first report explaining the change in the carbohydrate structure of AFP with different affinity to ConA on the enzymatic basis in a renal cell carcinoma.

Biomarkers, Tumor↗
PubMed1996

Mechanism on disorders of coagulation and fibrinolysis in diabetes.

Determination of various important parameters of coagulation and fibrinolysis, clinical characteristics, and levels of serum lipid were compared in 193 patients with NIDDM and 50 control subjects. Levels of fibrinogen, tissue factor pathway inhibitor (TFPI), thrombin-anti-thrombin complex, and plasminogen activator inhibitor 1 in plasma increased significantly in the diabetic patients. Levels of TFPI correlated significantly with levels of total cholesterol. In the patients with coronary heart disease or cerebral infarction, levels of lipoprotein(a) increased significantly. From these results, we have concluded that there is a thrombotic tendency or at least an imbalance between the hemostatic and thrombosis-protecting system in diabetic patients, especially in patients with angiopathy.

Blood Coagulation Disorders↗