Ca2+ Mobilization and Aggregation in Platelets

Platelets play an important role in physiological hemostatic mechanisms. In contrast, platelet activation has been implicated in pathological conditions, such as atherosclerosis, angiogenesis, and inflammation. Thrombin is considered to be of particular pathological importance as a platelet-activating substance, and thrombin-activated platelets are detected in the blood of patients with advanced occlusive arterial disease. Ca2+ acts as a second messenger in platelet activation, and the regulation of intracellular Ca2+ concentrations ([Ca2+]i) is important for controlling platelet functions. However, changes in [Ca2+]i by antiplatelet agents remain unclear. Therefore, we herein investigated the relationship between [Ca2+]i and the intensity of platelet aggregation after a thrombin stimulation, the relationship between [Ca2+]i and the intensity of platelet aggregation by antiplatelet agents, and the effects of antiplatelet agents on thrombin-activated platelets as a surrogate platelet model for arterial occlusive disease. Fura2-loaded platelets were treated with phosphate-buffered saline or a low concentration of thrombin (0.005 U/mL), followed by antiplatelet agents (aspirin or cilostazol), and changes in [Ca2+]i and the intensity of platelet aggregation by the thrombin stimulation were measured using fluorescence spectrophotometry. Changes in [Ca2+]i and the intensity of platelet aggregation after the thrombin stimulation as well as the relationship between [Ca2+]i and the intensity of platelet aggregation by antiplatelet agents indicated that cilostazol exerted stronger antiplatelet effects than aspirin and also that antiplatelet effects may be attenuated in thrombin-activated platelets. The present results also suggest the utility of thrombin-activated platelets as a surrogate platelet model for arterial occlusive disease. These results may contribute to future drug development for antiplatelet therapy

漢方生薬蒼朮の抗炎症作用に関する研究

13301甲第4361号博士(創薬科学)金沢大学博士論文本文Full 以下に掲載：Journal of Traditional Medicines 30(3) pp.124-131 2013. 和漢医薬学会. 共著者：Toshiyuki Atsumi, Akiho Iwashita, Isao Ohtsuka, Nobuko Kakiuchi, Yohei Sasaki, Masayuki Mikage, Kazuo Toriizuk

DNA sequencing analysis of ITS and 28S rRNA of Poria cocos

金沢大学大学院自然科学研究科生理活性物質科学金沢大学薬学部We determined the DNA sequences of the internal transcribed spacer 1 and 2 (ITS 1 and 2), the 5.8S rRNA gene and most of the 28S rRNA gene of Poria cocos for the first time, and conducted analysis of 20 samples including cultured mycelias and crude drug materials obtained from various localities and markets. Direct sequencing of the ITS 1 and 2 regions of the samples, except for four wild samples, showed that they had identical DNA sequences for ITS 1 and 2 with nucleotide lengths of 997 bps and 460 bps, respectively. By cloning, the four wild samples were found to have combined sequences of common ITS sequences with 1 or 2-base-pair insertions. Altogether both ITS 1 and 2 sequences were substantially longer than those of other fungal crude drugs such as Ganoderma lucidum and Polyporus umbellatus. Thus, Poria cocos could be distinguished from these crude drugs and fakes by comparing the nucleotide length of PCR products of ITS 1 and 2. Contrary to the basic homogeneity in ITS 1 and 2, three types (Group 1, 2, 3) of the 28S rRNA gene with distinctive differences in length and sequence were found. Furthermore, Group 1 could be divided into three subgroups depending on differences at nucleotide position 690. Products with different types of 28S rRNA gene were found in crude drugs from Yunnan and Anhui Provinces as well as the Korean Peninsula, suggesting that the locality of the crude drugs does not guarantee genetic uniformity. The result of DNA typing of Poria cocos may help discrimination of the quality of the crude drug by genotype. © 2007 Pharmaceutical Society of Japan

Difference in cultivation characteristics and genetic polymorphism between Chinese and Japanese strains of Wolfiporiacocos Ryvarden et Gilbertson (Poria cocos Wolf)

発行後1年より全文公開Poria, a dried sclerotium of Wolfiporiacocos Ryvarden et Gilbertson (Polyporaceae) has been used as a crude drug in both Chinese and Japanese (Kampo) traditional medicines. Recently, cultivated products of Chinese Poria strains have accounted for most of the market, while the cultivation of Japanese Poria strains has not been successful. Aiming to determine the relationship between the differences in cultivation characteristics and genetic polymorphism, we conducted a field cultivation experiment, a rot test, and rapid amplification of polymorphic DNA (RAPD) analysis of Poria strains collected from China and Japan: 3 Chinese and 7 Japanese strains. In field cultivation, although there was no marked inferiority of Japanese strains to Chinese ones in either mycelium propagation or the rate of sclerotium formation, Chinese strains formed whiter sclerotia with a mean size more than twice that of Japanese ones. Representatives of Chinese and Japanese strains, Yunnan and Kaimondake, respectively, were tested for wood-rotting ability. More wood was utilized and the wood color was darker in trials of the Yunnan strain. Amplifications of total DNA of these 10 fungal strains with 2 primers, PC-6 and PC-11, in RAPD analysis showed a difference in the amplicon profile between Japanese and Chinese strains, suggesting differences in their genetic background. © 2011 The Japanese Society of Pharmacognosy and Springer

Significance of fully automated tests for the diagnosis of antiphospholipid syndrome

AbstractAntiphospholipid antibodies (aPLs) can vary both immunologically and functionally, thus it is important to effectively and correctly identify their presence when diagnosing antiphospholipid syndrome. Furthermore, since many immunological/functional tests are necessary to measure aPLs, complete examinations are often not performed in many cases due to significant burden on the testing departments. To address this issue, we measured aPLs defined according to the classification criteria (anticardiolipin antibody: aCL) IgG/IgM and anti-β2 glycoprotein I antibody (aβ2GPI) (IgG/IgM) as well as non-criteria antibodies (aCL IgA, aβ2GPI IgA and aβ2GPI domain I), in a cohort of 211 patients (61 APS, 140 disease controls and 10 healthy individuals). APLs were measured using a fully automated chemiluminescent immunoassay instrument (BIO-FLASH®/ACL AcuStar®) and with conventional ELISA tests. We demonstrated that both sensitivity and accuracy of diagnosis of aCL IgG and aβ2GPI IgG were high, in agreement with the past reports. When multiple aPLs were examined, the accuracy of diagnosis increased. The proportion of APS patients that were positive for 2 or more types of aPLs (47/61, 77%) was higher than that of patients with systemic lupus erythematosus (SLE)(3/37, 9%), those with non-SLE connective tissues diseases (1/53,2%), those with other diseases or healthy volunteers. Based on these findings, it was concluded that the fully automated chemiluminescent immunoassay instrument, which allows the simultaneous evaluation of many types of aPLs, offers clear advantages for a more complete, more rapid and less labor-intensive alternative to running multiple ELISA and could help in better diagnosis for suspected APS patients

隣接基効果を伴わない立体選択的糖鎖合成の試み

When oligosaccharides are built by coupling of sugars, stereoselectivity of glycosidic bonds is important for the effective synthesis of the target compound. Stereoselectivity of glycosylation depend on neighbouring group, solvents, and temperature. We tried to synthesize a glycosphingolipid from Neurospora crassa

子嚢菌 Hirsutella rhossiliensis 由来糖脂質の合成

Elucidation of the function of glycolipids in natural products is very important because ecology of animals containing them is not only understood, but also their compounds will lead to development of new drugs. This research tried to synthesis of new glycosphingolipids (1, 2, and 3) that were isolated from Hirsutella rhossiliensis. They have neogala-series, β-D-Galp(1→6)-β-D-Galp(1→6)-β-D-Galp, as core structure. Compound 1 contains also in Neurospora crassa, we already reported about synthesis of it. We attempted to synthesize of compounds 2 and 3

Superconducting anisotropy and evidence for intrinsic pinning in single crystalline MgB2_2

We examine the superconducting anisotropy $\gamma_c = (m_c / m_{ab})^{1/2}$ of a metallic high-$T_c$ superconductor MgB$_2$ by measuring the magnetic torque of a single crystal. The anisotropy $\gamma_c$ does not depend sensitively on the applied magnetic field at 10 K. We obtain the anisotropy parameter $\gamma_c = 4.31 \pm 0.14$. The torque curve shows the sharp hysteresis peak when the field is applied parallel to the boron layers. This comes from the intrinsic pinning and is experimental evidence for the occurrence of superconductivity in the boron layers.Comment: REVTeX 4, To be published in Physical Review

Chemical Synthesis of Sialyl Glycosides for Elucidation of Biological Phenomena

糖質に分類されるシアル酸は、様々な生体機能を有していることが知られている。従って、シアル酸を含む糖鎖を化学合成することは、生命現象の解明に寄与するものと考えられる。しかし、シアル酸を糖供与体とする糖鎖合成は困難とされており、近年多くの研究者らによって、新たな処方が開発されてきている。我々は、シアル酸が持つ生体機能の興味を持ち、これを有する糖鎖誘導体 (5) の合成を試みた。The sialic acids are now defined as a family of carbohydrates, have very important biological functions. Thus, it considers that oligosaccharides containing them employ elucidation of biological phenomena. However, for synthesis of them glycosylations using donor of sialic acid derivative have been very hard to achieve both high yields and stereoselectivity of them. But recently, Synthesis methods of oligosaccharides containing sialic acids were developed by many researchers. Highly regioand α-stereoselective sialyl glycoside syntheses have been achieved by using, as glycosyl donors, the 2-thioglycoside of Neu5Ac. We were interested in biological functions of oligosaccharide containing sialic acid, and tried to synthesize sialyl lewis X and synthesized trisaccharide derivative which was precursor of sialyl lewis X, α-L-Neu5Ac(2 → 3)β-D-Gal(1 → 4)β-D-GlcNAc-MP