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Dive into the research topics where Kazuyuki Miyashita is active.

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Featured researches published by Kazuyuki Miyashita.


Clinical & Experimental Metastasis | 2006

Role of CCR1 and CCR5 in homing and growth of multiple myeloma and in the development of osteolytic lesions: a study in the 5TMM model

Eline Menu; Evy De Leenheer; Hendrik De Raeve; Les Coulton; Takeshi Imanishi; Kazuyuki Miyashita; Els Van Valckenborgh; Ivan Van Riet; Ben Van Camp; Richard Horuk; Peter I. Croucher; Karin Vanderkerken

Multiple myeloma (MM) is a plasma cell malignancy, characterized by the localization of the MM cells in the bone marrow (BM), where they proliferate and induce osteolysis. The MM cells first need to home or migrate to the BM to receive necessary survival signals. In this work, we studied the role of CCR1 and CCR5, two known chemokine receptors, in both chemotaxis and osteolysis in the experimental 5TMM mouse model. A CCR1–specific (BX471) and a CCR5–specific (TAK779) antagonist were used to identify the function of both receptors. We could detect by RT-PCR and flow cytometric analyses the expression of both CCR1 and CCR5 on the cells and their major ligand, macrophage inflammatory protein 1α (MIP1α) could be detected by ELISA. In vitro migration assays showed that MIP1α induced a 2-fold increase in migration of 5TMM cells, which could only be blocked by TAK779. In vivo homing kinetics showed a 30% inhibition in BM homing when 5TMM cells were pre-treated with TAK779. We found, in vitro, that both inhibitors were able to reduce osteoclastogenesis and osteoclastic resorption. In vivo end-term treatment of 5T2MM mice with BX471 resulted in a reduction of the osteolytic lesions by 40%; while TAK779 treatment led to a 20% decrease in lesions. Furthermore, assessment of the microvessel density demonstrated a role for both receptors in MM induced angiogenesis. These data demonstrate the differential role of CCR1 and CCR5 in MM chemotaxis and MM associated osteolysis and angiogenesis.


Atherosclerosis | 2013

Circulating soluble RAGE as a predictive biomarker of cardiovascular event risk in patients with type 2 diabetes.

Keiko Fujisawa; Naoto Katakami; Hideaki Kaneto; Toyoko Naka; Mitsuyoshi Takahara; Fumie Sakamoto; Yoko Irie; Kazuyuki Miyashita; Fumiyo Kubo; Tetsuyuki Yasuda; Taka-aki Matsuoka; Iichiro Shimomura

It is still controversial whether circulating soluble form of receptor for AGE (sRAGE) is associated with atherosclerosis in diabetic patients. In this study, we enrolled 276 Japanese type 2 diabetic subjects without history of cardiovascular disease (CVD), assessed their baseline clinical and biochemical data including serum sRAGE levels, and prospectively evaluated the association between these parameters and CVD events. The median follow-up period was 5.6 years and there were 25 new CVD events. The tertile analysis showed that the risk for CVD events was higher as serum sRAGE levels were increased (p for trend = 0.046). A multivariate Cox proportional hazards regression analysis revealed that serum sRAGE levels were independently associated with CVD (HR per 1SD = 1.59, 95% CI 1.04-2.45, p = 0.034), even after adjusting for conventional coronary risk factors. In summary, elevated sRAGE levels were associated with the increased risk of CVD in Japanese type 2 diabetic subjects.


Endocrine | 2012

Serum vitamin D levels are decreased and associated with thyroid volume in female patients with newly onset Graves' disease.

Tetsuyuki Yasuda; Yasuyuki Okamoto; Noboru Hamada; Kazuyuki Miyashita; Mitsuyoshi Takahara; Fumie Sakamoto; Takeshi Miyatsuka; Tetsuhiro Kitamura; Naoto Katakami; Dan Kawamori; Michio Otsuki; Taka-aki Matsuoka; Hideaki Kaneto; Iichiro Shimomura

It has been shown that vitamin D deficiency is associated with autoimmune diseases, including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), inflammatory bowel disease (IBD), multiple sclerosis (MS) and type 1 diabetes (T1DM), and that vitamin D supplementation prevents the onset and/or development of these autoimmune diseases [1]. Furthermore, it was reported more recently that patients with Hashimoto’s thyroiditis, an autoimmune thyroid disease had lower vitamin D levels [2]. However, there are few studies examining vitamin D status in patients with newly onset Graves’ disease. In the present study, we evaluated the vitamin D status in female patients with newly onset GD and the association of serum vitamin D levels with the clinical factors related to GD.


Endocrine | 2013

Serum vitamin D levels are decreased in patients without remission of Graves’ disease

Tetsuyuki Yasuda; Yasuyuki Okamoto; Noboru Hamada; Kazuyuki Miyashita; Mitsuyoshi Takahara; Fumie Sakamoto; Takeshi Miyatsuka; Tetsuhiro Kitamura; Naoto Katakami; Dan Kawamori; Michio Otsuki; Taka-aki Matsuoka; Hideaki Kaneto; Iichiro Shimomura

Graves’ disease (GD) is an autoimmune thyroid disease in which thyrotropin receptor autoantibodies (TRAb) cause hyperthyroidism. Although medical treatment with antithyroid drugs (ATD) is the first choice treatment for GD in Japan and Europe, a remission rate of GD with ATD is not satisfactory, and many patients need long-term treatment with ATD or further treatments such as radioactive iodine therapy or thyroidectomy [1]. Therefore, it is very important to identify the factors relating to the remission of GD. It has been recently shown that vitamin D deficiency is associated with the onset and/or development of several autoimmune diseases, including multiple sclerosis (MS), inflammatory bowel disease (IBD), and type 1 diabetes (T1DM) [2]. Furthermore, it has been reported more recently that patients with autoimmune thyroid diseases including GD have lower vitamin D status [3, 4]. However, there is no study comparing vitamin D status between the patients with and without remission of GD. In the present study, we examined vitamin D status in female patients with and without remission of GD and discussed the role of vitamin D in the pathogenesis and/or prognosis of GD.


Tetrahedron Letters | 1999

Synthesis of a conformationally locked AZT analogue, 3′-azido-3′-deoxy-2′-O,4′-C-methylene-5-methyluridine

Satoshi Obika; Jun-ichi Andoh; Tomomi Sugimoto; Kazuyuki Miyashita; Takeshi Imanishi

Abstract A bicyclic 3′-azido-3′-deoxythymidine (AZT) analogue with a locked N-conformation, 3′-azido-3′-deoxy-2′- O ,4′- C -methylene-5-methyluridine ( 1a ), and its 3′-amino derivative, 3′-amino-3′-deoxy-2′- O ,4′- C -methylene-5-methyluridine ( 1b ), were successfully synthesized from D-glucose. The conformation of 1a was also discussed by means of 1 H NMR measurements and a molecular modeling (PM3) study.


Diabetes Care | 2011

Basal Insulin Requirement Is ∼30% of the Total Daily Insulin Dose in Type 1 Diabetic Patients Who Use the Insulin Pump

Akio Kuroda; Hideaki Kaneto; Tetsuyuki Yasuda; Munehide Matsuhisa; Kazuyuki Miyashita; Noritaka Fujiki; Keiko Fujisawa; Tsunehiko Yamamoto; Mitsuyoshi Takahara; Fumie Sakamoto; Taka-aki Matsuoka; Iichiro Shimomura

OBJECTIVE To investigate the basal insulin requirement in total daily insulin dose in Japanese type 1 diabetic patients who use the insulin pump. RESEARCH DESIGN AND METHODS The basal insulin requirement in 35 type 1 diabetic patients without detectable C-peptide using the insulin pump (Paradigm 712) was investigated during 2–3 weeks of hospitalization. The patients were served diabetic diets of 25–30 kcal/kg ideal body weight. Each meal omission was done to confirm stable blood glucose levels within 30 mg/dL variance until the next meal. Target blood glucose level was set at 100 mg/dL before each meal and 150 mg/dL at 2 h after each meal. RESULTS Total daily insulin dose was 31.6 ± 8.5 units, and total basal insulin requirement was 8.7 ± 2.9 units, which was 27.7 ± 6.9% of the total daily dose. CONCLUSIONS Basal insulin requirement is ∼30% of the total daily dose in Japanese type 1 diabetic patients who use the insulin pump.


Diabetes Research and Clinical Practice | 2011

Subclinical hypothyroidism is independently associated with albuminuria in people with type 2 diabetes.

Tetsuyuki Yasuda; Hideaki Kaneto; Akio Kuroda; Tsunehiko Yamamoto; Mitsuyoshi Takahara; Toyoko Naka; Kazuyuki Miyashita; Keiko Fujisawa; Fumie Sakamoto; Naoto Katakami; Taka-aki Matsuoka; Iichiro Shimomura

We examined a possible association between subclinical hypothyroidism and albuminuria in 159 people with type 2 diabetes. Patients with subclinical hypothyroidism had significantly higher levels of urinary albumin-to-creatinine ratio (UACR) than those with euthyroidism. Multivariate logistic regression analyses demonstrated that serum TSH level was an independent risk factor of albuminuria.


Bioorganic & Medicinal Chemistry | 2001

Symmetrical cationic triglycerides: an efficient synthesis and application to gene transfer

Satoshi Obika; Wei Yu; Atsuko Shimoyama; Takeshi Uneda; Kazuyuki Miyashita; Takefumi Doi; Takeshi Imanishi

Some cationic triglycerides 1Aa-1Cb which have a symmetrical structure were effectively synthesized and formulated into cationic liposomes with the co-lipid dioleoylphosphatidylethanolamine (DOPE) and/or dilauroylphosphatidylcholine (DLPC). The plasmid encoding a luciferase was delivered into CHO cells by using these cationic liposomes. Our symmetrical cationic triglycerides showed high transfection activity when DOPE was used as a co-lipid. Among the symmetrical cationic triglycerides synthesized here, 1Ab and 1Ac, which have an oleoyl group at the 1- and 3-position in the glycerol backbone and also have a relatively long linker connecting the 2-hydroxy group in glycerol with the quaternary ammonium head group, were found to be the most suitable for gene delivery into cells. The transfection activity of the symmetrical cationic triglyceride 1Ab was comparable with that of its asymmetrical congener 6 and several times higher than that of Lipofectin.


Diabetes Research and Clinical Practice | 2014

Vitamin D deficiency is significantly associated with retinopathy in young Japanese type 1 diabetic patients.

Naoki Shimo; Tetsuyuki Yasuda; Hideaki Kaneto; Naoto Katakami; Akio Kuroda; Fumie Sakamoto; Mitsuyoshi Takahara; Yoko Irie; Keiko Horikawa; Kazuyuki Miyashita; Takeshi Miyatsuka; Kazutomi Yoshiuchi; Dan Kawamori; Ken’ya Sakamoto; Taka-aki Matsuoka; Keisuke Kosugi; Iichiro Shimomura; Munehide Matsuhisa

The aim of this study was to examine the possible association of vitamin D deficiency with diabetic retinopathy in 75 young Japanese type 1 diabetic patients. A multivariate regression analysis, duration of diabetes and vitamin D deficiency were independent determinants of diabetic retinopathy.


Tetrahedron Letters | 1997

SYNTHESIS AND CHEMILUMINESCENT PROPERTY OF THE NOVEL 1,2-DIOXETANES CONTAINING AN ACRIDANE-10-ACETATE MOIETY AS THE LUMINOPHORE AND TRIGGER UNIT

Takeshi Imanishi; Yohko Ueda; Ryoh Tainaka; Kazuyuki Miyashita; Nobuhiro Hoshino

Abstract Novel dioxetane derivatives 2 with an acridane-10-acetate moiety were prepared and tested for a potential chemiluminescent probe. The 10-acetate was found to play an important role both in stabilization and in base-mediated smooth degradation of the dioxetane ring.

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