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Biomedical subjects

Toshiaki Hanafusa

Publications and source records attributed to Toshiaki Hanafusa.

At least 73 records · Page 4Linked to original sources

Different migratory and proliferative properties of smooth muscle cells of coronary and femoral artery.

In the human coronary arteries, the intima begins to thicken from early adolescence and shows progressive thickening with age. We compared the response to vascular injury of the coronary and femoral arteries using a canine model. Both incorporation of 5-bromo-2'-deoxyuridine (BrdU) and neointimal formation after balloon injury were significantly greater in the coronary artery than in the femoral artery. Also, the proliferative and migratory activities of coronary smooth muscle cells (SMCs) were significantly greater than those of femoral SMCs in vitro. The level of phosphorylated myosin light chain (phospho-MLC) was higher in coronary SMCs than in femoral SMCs. Y-27632, a specific inhibitor of Rho-kinase, significantly inhibited the PDGF-induced migration of both coronary and femoral SMCs. In contrast, the migration of coronary SMCs, but not femoral SMCs, was inhibited by ML-9, a specific inhibitor of myosin light chain kinase (MLCK). These findings suggest that the contribution of Rho-kinase and MLCK differs between the different arteries. They also suggest that a neointima develops more easily in the coronary artery than in the femoral artery because of the greater proliferative and migratory activity of coronary SMCs. Differential activation of MLC might partly explain the increased proliferation and migration of coronary SMCs.

Amides↗

The relationship of psychological factors to the prognosis of hyperthyroidism in antithyroid drug-treated patients with Graves' disease.

OBJECTIVE: The relationship between emotional stress and the onset of hyperthyroidism has been well investigated, but the relationship between psychological factors and prognosis of antithyroid drug-treated hyperthyroidism is not well known. This study has examined not only emotional stresses but also patients' personality traits using specific tests. DESIGN: A prospective cohort study. SUBJECTS: Sixty-nine patients with hyperthyroid Graves' disease in the euthyroid state after 2-5 years of antithyroid drug therapy and 32 healthy subjects as the control group. MEASUREMENTS: Patients responded to three types of questionnaires, including the Minnesota Multiphasic Personality Inventory for personality traits, the Natsume's Stress Inventory for major life events, and the Hayashi's Daily Life Stress Inventory for daily life stresses. RESULTS: In the Graves' disease patients, stress scores of life events correlated significantly with serum TSH receptor antibody activity (r = 0.424, P < 0.001) and thyroid volume (r = 0.480, P < 0.001). When the patients were divided according to prognosis (41 with relapse and 28 with remission), four personality traits including hypochondriasis, depression, paranoia and psychasthenia (mental fatigue) were significantly (P = 0.0146, 0.0052, 0.0125, and 0.0186, respectively) more common in the relapsed Graves' disease group than those of the remitted group. Six personality traits of conversion hysteria, psychopathic deviation, masculinity and feminity, schizophrenia, hypomania, and social introversion were not significantly different between the two groups. The scores of daily hassles (problems of daily life) were also significantly (P = 0.0124) greater in the relapsed Graves' disease group than in the remitted group. The scale scores of depression and psychasthenia showed a positive correlation with scores of daily hassles (r = 0.535, P < 0.0001; r = 0.580, P < 0.0001, respectively), while an inverse correlation with scores of daily uplifts (r = -0.373, P = 0.0332; r = -0.322, P = -0.0120, respectively). CONCLUSIONS: The results suggest that major life events, personality traits of hypochondriasis and depression, paranoia, mental fatigue, and daily problems aggravate the prognosis of antithyroid drug-treated hyperthyroidism. Escape from life events is virtually impossible; thus coping strategies suggested by the physician may be useful in improving prognosis in Graves' disease.

Adult↗

Serum concentrations of remnant-like particles in hypothyroid patients before and after thyroxine replacement.

OBJECTIVES: Remnant-like particles (RLPs) reflect chylomicron remnants and very-low-density lipoprotein remnants, which are most likely to be atherogenic particles. To investigate the effect of thyroxine replacement on the metabolism of RLPs in hypothyroidism, we measured serum concentrations of RLPs during an oral fat-loading test in patients with hypothyroidism before and after thyroxine replacement. PATIENTS AND METHODS: Thirteen patients with hypothyroidism, having serum-free thyroxine (FT4) of 4.25 +/- 2.23 pmol/l (mean +/- SD) and TSH of 72.5 +/- 27.7 mU/l, participated in the study. Two-hundred grams of cream containing 32.9% of fat were given to each patient followed by blood draws every 2 h for 8 h. The patients became euthyroid after 3 months of T4 replacement, and the fat-loading tests were then repeated. RESULTS: Fasting levels of serum total cholesterol and low-density lipoprotein cholesterol were remarkably decreased after T4 therapy (P < 0.0005). Serum high-density lipoprotein cholesterol and triglyceride were also decreased by T4 therapy, not so remarkably but significantly (P < 0.05). Activities of lipoprotein lipase (LPL) and hepatic triglyceride lipase (HTGL) increased 52% and 85%, respectively, from the pretreatment values. Serum concentrations of remnant-like particle cholesterol (RLP-C) and remnant-like particle triglyceride (RLP-TG), measured by immunoseparation assays, significantly decreased from 0.14 +/- 0.03 to 0.09 +/- 0.03 mmol/l (P < 0.0005) and from 0.19 +/- 0.11-0.11 +/- 0.07 mmol/l (P < 0.01), respectively. In the fat-loading test, serum low-density lipoprotein cholesterol concentrations were not changed, while serum RLPs concentrations were increased and remained high throughout the test, with the peak value at 6 h in a hypothyroid condition. In an euthyroid condition after T4 therapy, the peak values of RLPs were obtained at 4 h, and the concentrations were decreased rapidly. As the result, areas under the curve of serum RLPs were decreased remarkably after T4 therapy. CONCLUSIONS: Hypothyroidism seems to be associated with a decrease in metabolism of serum RLPs. Such altered metabolism of RLPs may be related to the decreased activities of LPL and HTGL and can be corrected by T4 replacement therapy.

Area Under Curve↗

Nasal-type NK/T cell lymphoma of the orbit with distant metastases.

A case of a nasal-type NK/T cell lymphoma of the orbit with distant metastases is reported. The orbital lymphoma was angiodestructive with prominent necrosis and frequent apoptosis. Lymphoma cells were positive for CD56, cytotoxic molecules (granzyme B and TIA-1), and EBV. Despite local radiotherapy, the patient had a highly aggressive clinical course. A postmortem examination revealed distant metastases to the heart and lungs exhibiting angiocentric growth. TCR and Ig genes of a cardiac lesion were in germ line configuration. This case demonstrated that nasal-type NK/T cell lymphomas with a poor prognosis can occur in the orbit.

Aged↗

Successful catheter interventional therapy for acute coronary syndrome secondary to kawasaki disease in young adults.

Acute coronary syndrome occurred in 2 young adults who had a history of Kawasaki disease (KD), but few other coronary risk factors. The first patient was a 27-year-old male with acute myocardial infarction without stenosis detected by coronary arteriography 4 years earlier. Emergency coronary arteriography showed occlusion of the right coronary artery. Aspiration-thrombectomy and rescue balloon angioplasty were successfully performed. The second patient was a 32-year-old male with unstable angina. Right coronary arteriography showed total occlusion with severe calcification. Left coronary arteriography showed 99% stenosis at the proximal site of the circumflex artery, and a directional coronary atherectomy was performed. Histological examination of a specimen from this site revealed a lipid core, macrophages, and smooth muscle cells. Restenosis was not observed on follow-up coronary arteriography after 5-6 months in either case. The coronary stenosis in each case was probably caused by accelerated atherosclerosis at the site without aneurysm as it seemed to be 'normal' on arteriography. Conventional catheter intervention was effective treatment. The sequelae of KD should be recognized as independent coronary risk factors.

Acute Disease↗

Fulminant type 1 diabetes: a nationwide survey in Japan.

OBJECTIVE: To describe the clinical and immunologic characteristics of fulminant type 1 diabetes, a novel subtype of type 1 diabetes, we conducted a nationwide survey. RESEARCH DESIGN AND METHODS: History and laboratory data, including islet-related autoantibodies, were examined in 222 patients with fulminant and nonfulminant type 1 diabetes in our hospitals in addition to another 118 patients with fulminant type 1 diabetes located outside our hospitals in Japan. RESULTS: In our hospitals, of the 222 patients studied, 43 (19.4%) were diagnosed with fulminant type 1 diabetes, 137 (61.7%) were classified as having autoimmune type 1 diabetes, and 42 were type 1 diabetic subjects who were not fulminant and did not have anti-islet antibodies. An additional 118 fulminant patients outside our hospitals were enrolled, making a total of 161 fulminant type 1 diabetic subjects (83 male and 78 female subjects; 14 children/adolescents and 147 adults) identified from all over Japan. (In 2000, the average incidence was three cases per month.) Flu-like symptoms and pregnancy were more frequently observed in the fulminant than in the autoimmune group (P < 0.001). In the fulminant patients, 4.8% were positive for anti-GAD antibodies and none were positive for anti-islet antigen 2 antibodies. CONCLUSIONS: Fulminant type 1 diabetes is a distinct subtype and accounts for approximately 20% of the ketosis-onset type 1 diabetes cases in Japan. Flu-like symptoms are characteristic of disease onset. Metabolic derangement is more severe in this subtype than in autoimmune type 1 diabetes.

Adolescent↗

[Preferential distal muscle involvement in case of oculopharyngeal muscular dystrophy with (GCG) 13 expansion].

We reported a 52-year-old woman with oculopharyngeal muscular dystrophy (OPMD) harboring expanded (GCG) 13 mutation of the poly (A) binding protein 2 gene. She presented not only ptosis and dysphagia but distal dominant muscle atrophy in four extremities. CT demonstrated distal muscle atrophy with marked fat replacement in the biceps femoris, semitendinosus, membraneous, soleus, and gastrocnemius muscles. Although OPMD is considered to be a muscle disease, this patient showed even neurogenic features in the electrophysiological and pathological findings. Although previous reports indicate that OPMD is genetically homogeneous disease, some cases with OPMD may show some atypical features associated with neurogenic involvement.

Electromyography↗

In vivo activation of the constitutive androstane receptor beta (CARbeta) by treatment with dehydroepiandrosterone (DHEA) or DHEA sulfate (DHEA-S).

We investigated whether dehydroepiandrosterone (DHEA) or DHEA-sulfate (S) affected the activities of nuclear receptors, with special reference to constitutive androstane receptor beta (CARbeta). Administration of DHEA or DHEA-S enhanced the DNA binding of hepatic nuclear extracts to responsive elements for the retinoic acid receptor, the retinoic acid receptor beta 2 and the peroxisome proliferator activated receptor. The bound complexes were shown to be the CARbeta-RXR heterodimer by antibody-supershift assays. The expression of a target gene of CARbeta, Cyp2b10, was increased in liver by DHEA or DHEA-S treatment, suggesting that DHEA or DHEA-S actually activated CARbeta in vivo. It was suggested that the metabolic conversion of DHEA, DHEA-S to CARbeta ligands could occur in vivo and the metabolites could regulate the expression of CARbeta target gene expression. Our results provide new insights into the in vivo relationship between DHEA/DHEA-S and CARbeta activation.

Adjuvants, Immunologic↗

Metabolic consequence of long-term exposure of pancreatic beta cells to free fatty acid with special reference to glucose insensitivity.

Long-term exposure of the pancreatic beta cells to free fatty acid (FFA) reportedly inhibits glucose-stimulated insulin secretion. We here studied the impact of FFA on glucose and lipid metabolism in pancreatic beta cells with special reference to insulin secretion. Pancreatic beta-cell line MIN6 was exposed to various concentrations of palmitate for 3 days. Glucose-stimulated insulin secretion and insulin content were decreased corresponding to the concentration of the palmitate exposed. Glycolytic flux and ATP synthesis was unchanged, but pyruvate-stimulated change in NAD(P)H concentration was decreased. Pyruvate carboxylase was decreased at the protein level, which was restored by the removal of palmitate or the inhibition of beta-oxidation. Intracellular content of triglyceride and FFA were elevated, beta-oxidation was increased, and de novo lipogenesis from glucose was decreased. NADPH content and citrate output into the medium, which reflected pyruvate malate shuttle flux, were decreased, but malic enzyme activity was unaffected. The malic enzyme inhibitor alone inhibited insulin response to glucose. In conclusion, long-term exposure of FFA to beta cells inhibits glucose-stimulated insulin secretion via the decreased NADPH contents due to the inhibition of pyruvate carboxylase and malate pyruvate shuttle flux.

Animals↗

Beta cell neogenesis from ducts and phenotypic conversion of residual islet cells in the adult pancreas of glucose intolerant mice induced by selective alloxan perfusion.

The aim of this study was to clarify the pattern of beta cell neogenesis in the alloxan-perfused, beta cells-depleted segment of glucose intolerant mice induced by selective alloxan perfusion. First, duct cells proliferated in the perfused segment, then cells co-expressing multiple islet hormones and transcription factors such as PDX-1, Nkx2.2, Isl1, and Pax6 were observed in duct cells, and newly formed islet-like cell clusters (ICCs) containing beta cells were recognized. In residual beta cell-depleted islets, glucagon or somatostatin and PDX-1 double-positive immature endocrine cells were recognized. Glucagon or somatostatin, insulin and PDX-1 triple-positive cells then appeared and these cells appeared to undergo terminal differentiation into beta cells. In conclusion, we demonstrated at least two different processes of beta cell neogenesis, i.e., formation of new ICCs from ductal epithelium and redifferentiation of residual non-beta islet cells in this model. In addition, transcription factors that appear in the processes of endocrine cell development may also play essential roles during beta cell neogenesis from duct cells.

Alloxan↗

Terbutaline-induced triphasic changes in volume of rat alveolar type II cells: the role of cAMP.

Changes in the volume of rat alveolar type II cells (AT-II cells) induced by terbutaline, a beta(2)-agonist, were measured using video-enhanced contrast microscopy. The changes consisted of three phases: initial cell shrinkage, cell swelling, and gradual cell shrinkage. The initial cell shrinkage was Ca(2+)-dependent and was inhibited by quinine (a K+ channel blocker). The subsequent cell swelling was cAMP-dependent and was inhibited by amiloride (a Na+ channel blocker). The final cell shrinkage was cAMP-dependent and was inhibited by 5-nitro-2-(3-phenylpropylamino)-benzoate (NPPB, a Cl- channel blocker). Thus, terbutaline-induced cell volume changes were regulated by both Ca2+ and cAMP. Accumulation of cAMP alone, however, induced the Ca2+ -dependent cell shrinkage of AT-II cells and H-89 (a PKA inhibitor) inhibited terbutaline-induced cell volume changes. This suggests that cAMP accumulation stimulates the Ca2+ signal during terbutaline stimulation. In conclusion, terbutaline stimulates not only Na+ influx, but also K+ and Cl- release mediated via cAMP accumulation in rat AT-II cells, which induces the triphasic cell volume changes.

Adrenergic beta-Agonists↗

Overexpression of dominant-negative mutant hepatocyte nuclear fctor-1 alpha in pancreatic beta-cells causes abnormal islet architecture with decreased expression of E-cadherin, reduced beta-cell proliferation, and diabetes.

One subtype of maturity-onset diabetes of the young (MODY)-3 results from mutations in the gene encoding hepatocyte nuclear factor (HNF)-1 alpha. We generated transgenic mice expressing a naturally occurring dominant-negative form of human HNF-1 alpha (P291fsinsC) in pancreatic beta-cells. A progressive hyperglycemia with age was seen in these transgenic mice, and the mice developed diabetes with impaired glucose-stimulated insulin secretion. The pancreatic islets exhibited abnormal architecture with reduced expression of glucose transporter (GLUT2) and E-cadherin. Blockade of E-cadherin-mediated cell adhesion in pancreatic islets abolished the glucose-stimulated increases in intracellular Ca(2+) levels and insulin secretion, suggesting that loss of E-cadherin in beta-cells is associated with impaired insulin secretion. There was also a reduction in beta-cell number (50%), proliferation rate (15%), and pancreatic insulin content (45%) in 2-day-old transgenic mice and a further reduction in 4-week-old animals. Our findings suggest various roles for HNF-1 alpha in normal glucose metabolism, including the regulation of glucose transport, beta-cell growth, and beta-cell-to-beta-cell communication.

Animals↗

Thyroid hormone receptor interacting protein 3 (trip3) is a novel coactivator of hepatocyte nuclear factor-4alpha.

Mutations of the hepatocyte nuclear factor-4alpha (HNF-4alpha) gene are associated with a subtype of maturity-onset diabetes of the young (MODY1) that is characterized by impaired insulin secretion in response to a glucose load. HNF-4alpha, which is a transcription factor expressed in pancreatic beta-cells, plays an important role in regulating the expression of genes involved in glucose metabolism. Thus, cofactors that interact with HNF-4alpha and modify its transcriptional activity might also play an important role in regulating the metabolic pathways in pancreatic beta-cells, and the genes of such cofactors are plausible candidate genes for MODY. In the present study, we showed, using a yeast two-hybrid screening assay, that thyroid hormone receptor interacting protein 3 (Trip3) interacted with HNF-4alpha, and their interaction was confirmed by the glutathione S-transferase pull-down assay. Human Trip3 cDNA contained an open reading frame for a protein of 155 amino acids, and the gene was expressed in both pancreatic islets and MIN6 cells. Cotransfection experiments indicated that Trip3 could enhance (two- to threefold) the transcription activity of HNF-4alpha in COS-7 cells and MIN6 cells. These results suggest that Trip3 is a coactivator of HNF-4alpha. Mutation screening revealed that variation of the Trip3 gene is not a common cause of MODY/early-onset type 2 diabetes in Japanese individuals. Trip3 may play an important role in glucose metabolism by regulating the transcription activity of HNF-4alpha.

Animals↗

Hepatocyte nuclear factor-1alpha modulates pancreatic beta-cell growth by regulating the expression of insulin-like growth factor-1 in INS-1 cells.

Maturity-onset diabetes of the young type 3 (MODY3) is characterized by impaired insulin secretion. Heterozygous mutations in the gene encoding hepatocyte nuclear factor (HNF)-1alpha are the cause of MODY3. Transgenic mice overexpressing dominant-negative HNF-1alpha mutant in pancreatic beta-cells and HNF-1alpha knockout mice are animal models of MODY3. These mice exhibit defective glucose-stimulated insulin secretion and have reduced beta-cell mass and beta-cell proliferation rate. Here we examined the effect of HNF-1alpha on beta-cell proliferation by overexpressing a human naturally occurring dominant- negative mutation P291fsinsC in INS-1 cells under the control of doxycycline-induction system. INS-1 cells overexpressing P291fsinsC showed apparent growth impairment. The proliferation rate estimated by [(3)H]thymidine incorporation was significantly reduced in P291fsinsC-expressing INS-1 cells compared with noninduced or wild-type HNF-1alpha-overexpressing INS-1 cells. Growth inhibition occurred at the transition from G1 to S cell cycle phase, with reduced expression of cyclin E and upregulation of p27. cDNA array analysis revealed that the expression levels of IGF-1, a major growth factor for beta-cells, and macrophage migration inhibitory factor (MIF), a cytokine expressed in pancreatic beta-cells, were reduced in P291fsinsC-HNF-1alpha-expressing INS-1 cells. Although MIF seemed to have proliferative function, blockade of MIF action by anti-MIF antibody stimulated INS-1 cell proliferation, excluding its direct role in the growth impairment. However, addition of IGF-1 to P291fsinsC-expressing INS-1 cells rescued the growth inhibition. Our data suggest that HNF-1alpha is critical for modulating pancreatic beta-cell growth by regulating IGF-1 expression. IGF-1 might be a potential therapeutic target for the treatment of MODY3.

Animals↗

[Nine-year's follow up on the appearance of autoantibodies in a child with idiopathic thrombocytopenic purpura subsequently developing lupus with central nervous system manifestations].

We describe a 23-year-old female who developed SLE 9 years after asymptomatic idiopathic thrombocytopenic purpura (ITP) with positive antinuclear antibody (ANA). Although the platelet count was normal before the onset of SLE, the titer of ANA was gradually increased and also autoantibodies, including antibodies to SS-A/Ro, single-stranded DNA (ss-DNA) and nuclear ribonucleoprotein (RNP) changed to positive. At 23 years of age, the patient was admitted to our hospital because of fever, butterfly rash and polyarthritis. Anti double-strand DNA (ds-DNA) antibody and anti Smith antigen (Sm) antibody were positive and the platelet count and titer of complements were decreased. The patient was diagnosed as SLE and treated with 60 mg/day of prednisolone. Despite steroid therapy, psychiatric symptoms appeared. Additional treatments with steroid pulse therapy and double filtration plasmaphresis resulted in the improvement of SLE including the central nervous system manifestations. This case suggested that increased titer of ANA and the appearance of antibodies to SS-A, ss-DNA, RNP, ds-DNA and Sm in ITP patients predict the development of SLE. Routine checkup of autoantibodies is needed to manage ITP with positive ANA.

Adult↗