132 research outputs found
Bazedoxifene, a selective estrogen receptor modulator, reduces cerebral aneurysm rupture in Ovariectomized rats.
BackgroundEstrogen deficiency is thought to be responsible for the higher frequency of aneurysmal subarachnoid hemorrhage in post- than premenopausal women. Estrogen replacement therapy appears to reduce this risk but is associated with significant side effects. We tested our hypothesis that bazedoxifene, a clinically used selective estrogen receptor (ER) modulator with fewer estrogenic side effects, reduces cerebral aneurysm rupture in a new model of ovariectomized rats.MethodsTen-week-old female Sprague-Dawley rats were subjected to ovariectomy, hemodynamic changes, and hypertension to induce aneurysms (ovariectomized aneurysm rats) and treated with vehicle or with 0.3 or 1.0 mg/kg/day bazedoxifene. They were compared with sham-ovariectomized rats subjected to hypertension and hemodynamic changes (HT rats). The vasoprotective effects of bazedoxifene and the mechanisms underlying its efficacy were analyzed.ResultsDuring 12 weeks of observation, the incidence of aneurysm rupture was 52% in ovariectomized rats. With no effect on the blood pressure, treatment with 0.3 or 1.0 mg/kg/day bazedoxifene lowered this rate to 11 and 17%, almost the same as in HT rats (17%). In ovariectomized rats, the mRNA level of ERα, ERβ, and the tissue inhibitor of metalloproteinase-2 was downregulated in the cerebral artery prone to rupture at 5 weeks after aneurysm induction; the mRNA level of interleukin-1β and the matrix metalloproteinase-9 was upregulated. In HT rats, bazedoxifene restored the mRNA level of ERα and ERβ and decreased the level of interleukin-1β and matrix metalloproteinase-9. These findings suggest that bazedoxifene was protective against aneurysmal rupture by alleviating the vascular inflammation and degradation exacerbated by the decrease in ERα and ERβ.ConclusionsOur observation that bazedoxifene decreased the incidence of aneurysmal rupture in ovariectomized rats warrants further studies to validate this response in humans
Hyperhomocysteinemia induced by excessive methionine intake promotes rupture of cerebral aneurysms in ovariectomized rats.
BackgroundHyperhomocysteinemia (HHcy) is associated with inflammation and a rise in the expression of matrix metalloproteinase-9 (MMP-9) in the vascular wall. However, the role of HHcy in the growth and rupture of cerebral aneurysms remains unclear.MethodsThirteen-week-old female Sprague-Dawley rats were subject to bilateral ovariectomy and ligation of the right common carotid artery and fed an 8 % high-salt diet to induce cerebral aneurysms. Two weeks later, they underwent ligation of the bilateral posterior renal arteries. They were divided into two groups and methionine (MET) was or was not added to their drinking water. In another set of experiments, the role of folic acid (FA) against cerebral aneurysms was assessed.ResultsDuring a 12-week observation period, subarachnoid hemorrhage due to aneurysm rupture was observed at the anterior communicating artery (AcomA) or the posterior half of the circle of Willis. HHcy induced by excessive MET intake significantly increased the incidence of ruptured aneurysms at 6-8 weeks. At the AcomA of rats treated with MET, we observed the promotion of aneurysmal growth and infiltration by M1 macrophages. Furthermore, the mRNA level of MMP-9, the ratio of MMP-9 to the tissue inhibitor of metalloproteinase-2, and the level of interleukin-6 were higher in these rats. Treatment with FA abolished the effect of MET, suggesting that the inflammatory response and vascular degradation at the AcomA is attributable to HHcy due to excessive MET intake.ConclusionsWe first demonstrate that in hypertensive ovariectomized rats, HHcy induced by excessive MET intake may be associated with the propensity of the aneurysm wall to rupture
Solubilization of single-walled carbon nanotubes by entanglements between them and hyperbranched phenolic polymer
金沢大学理工研究域物質化学系Hyperbranched phenolic polymer (HBP) was prepared by Lewis acid-catalyzed polycondensation of bifunctional phenolic monomer with trifunctional phenolic monomer. By choosing an appropriate Lewis acid, HBP was successfully obtained. By using physical adsorption of HBP on a single-walled carbon nanotube (SWCNT) surface, solubilization of SWCNTs was examined. SWCNTs were soluble with extended branches of HBP in N,N-dimethylformamide (DMF) solution, while they were insoluble in a linear phenolic polymer. In the presence of shrinking branches of HBP in tetrahydrofuran, SWCNTs were hardly soluble. Entanglements between extended branches of HBP and SWCNT in DMF solution resulted in high solubility of SWCNTs. © 2008 Elsevier Ltd. All rights reserved
Defection-selective solubilization and chemically-responsive solubility switching of single-walled carbon nanotubes with cucurbit[7]uril
金沢大学理工研究域物質化学系Single-walled carbon nanotubes (SWCNTs) were suspended in aqueous media with cucurbit[7]uril (CB7), while SWCNTs were insoluble with cucurbit[5]uril (CB5). Moreover, defection-selective solubilization of SWCNTs with CB7 was demonstrated. © The Royal Society of Chemistry
Effects of various drugs on platelet functions
Background: The hyperfunction and activation of platelets have been strongly implicated in the development and recurrence of arterial occlusive disease, and various antiplatelet drugs are used to treat and prevent such diseases. New antiplatelet drugs and many other drugs have been developed, but some drugs may have adverse effects on platelet functions.
Objective: The aim of this study was to establish an evaluation method for evaluating the effect and adverse effect of various drugs on platelet functions.
Materials and methods: Human erythroid leukemia (HEL) cells were used after megakaryocytic differentiation with phorbol 12-myristate 13-acetate as an alternative to platelets. Drugs were evaluated by changes in intracellular Ca2+ concentration ([Ca2+]i) mobilization in Fura2-loaded phorbol 12-myristate 13-acetate-induced HEL cells. Aspirin and cilostazol were selected as antiplatelet drugs and ibuprofen and sodium valproate as other drugs.
Results: There was a positive correlation between [Ca2+]i and platelet aggregation induced by thrombin. Aspirin (5.6–560 µM) and cilostazol (5–10 µM) significantly inhibited thrombin-induced increases in [Ca2+]i in a concentration-dependent manner. On the other hand, ibuprofen (8–200 µM) and sodium valproate (50–1,000 µg/mL) also significantly inhibited thrombin-induced increases in [Ca2+]i in a concentration-dependent manner. Furthermore, the interaction effects of the simultaneous combined use of aspirin and ibuprofen or sodium valproate were evaluated. When the inhibitory effect of aspirin was higher than that of ibuprofen, the effect of aspirin was reduced, whereas when the inhibitory effect of aspirin was lower than that of ibuprofen, the effect of ibuprofen was reduced. The combination of aspirin and sodium valproate synergistically inhibited thrombin-induced [Ca2+]i.
Conclusion: It is possible to induce HEL cells to differentiate into megakaryocytes, which are a useful model for the study of platelet functions, and the quantification of the inhibition of thrombin-induced increases in [Ca2+]i is applicable to the evaluation of the effects of various drugs on platelets
CPL on/off control of an assembled system by water soluble macrocyclic chiral sources with planar chirality
Herein, we report the synthesis and planar chiral properties of a pair of water-soluble cationic pillar[5]arenes with stereogenic carbons. Interestingly, although units of the molecules were rotatable, only one planar chiral diastereomer existed in water in both cases. As a new type of chiral source, these molecules transmitted chiral information from the planar chiral cavities to the assembly of a water-soluble extended π-conjugated compound, affording circularly polarized luminescence (CPL). The chirality transfer process and resulting CPL were extremely sensitive to the feed ratio of the chiral pillar[5]arenes owing to the combined action of their planar chirality, bulkiness, and strong binding properties. When a limited amount of chiral source was added, further assembly of the extended π-conjugated compound into helical fibers with CPL was triggered. Unexpectedly, larger amounts of chiral source destroyed the helical fiber assemblies, resulting in elimination of the chirality and CPL properties from the assembled structures
The carbonization of aromatic molecules with three-dimensional structures affords carbon materials with controlled pore sizes at the Ångstrom-level
分子構造により細孔径を制御したカーボンを開発. 京都大学プレスリリース. 2021-05-24.Carbon materials with controlled pore sizes at the nanometer level have been obtained by template methods, chemical vapor desorption, and extraction of metals from carbides. However, to produce porous carbons with controlled pore sizes at the Ångstrom-level, syntheses that are simple, versatile, and reproducible are desired. Here, we report a synthetic method to prepare porous carbon materials with pore sizes that can be precisely controlled at the Ångstrom-level. Heating first induces thermal polymerization of selected three-dimensional aromatic molecules as the carbon sources, further heating results in extremely high carbonization yields (>86%). The porous carbon obtained from a tetrabiphenylmethane structure has a larger pore size (4.40 Å) than those from a spirobifluorene (4.07 Å) or a tetraphenylmethane precursor (4.05 Å). The porous carbon obtained from tetraphenylmethane is applied as an anode material for sodium-ion battery
Evaluation of Surface CD56 Expression
Surface CD56 is the most important cell marker for defining NK cells. However, the relationship between the expression of surface CD56 and NK cell activity has not yet been elucidated in detail. Thirteen healthy volunteers were enrolled in the present study. Peripheral blood mononuclear cells (PBMCs) were stimulated with rIL-2 or rIL-12 (1, 10, 100 U/mL) for 18 h at 37 ℃. After incubation, surface CD56 expression on NK cells was evaluated using a flow cytometric analysis. A colorimetric-based lactate dehydrogenase (LDH) assay was used for experiments on cytotoxicity. IFN-γmRNA gene expression was quantified by real-time PCR. The expression level of surface CD56 on NK cells, cytotoxicity, and IFN-γmRNA gene expression were significantly increased by the rIL-2 and rIL-12 stimulations. In addition, a positive correlation was found between surface CD56 expression and cytotoxic activity or IFN-γmRNA gene expression. We revealed that the quantification of surface CD56 expression was applicable to the evaluation of cytotoxicity and IFN-γproduction in activated NK cells. These results suggest that the measurement of surface CD56 expression represent an easy and rapidly reproducible technique to evaluate the activated state of NK cells and monitor NK cell activity in immunotherapy
選択的エストロゲン受容体モジュレーターのバゼドキシフェンは卵巣摘除ラットにおいて脳動脈瘤破裂を抑制する
Background: Estrogen deficiency is thought to be responsible for the higher frequency of aneurysmal subarachnoid hemorrhage in post- than premenopausal women. Estrogen replacement therapy appears to reduce this risk but is associated with significant side effects. We tested our hypothesis that bazedoxifene, a clinically used selective estrogen receptor (ER) modulator with fewer estrogenic side effects, reduces cerebral aneurysm rupture in a new model of ovariectomized rats.
Methods: Ten-week-old female Sprague-Dawley rats were subjected to ovariectomy, hemodynamic changes, and hypertension to induce aneurysms (ovariectomized aneurysm rats) and treated with vehicle or with 0.3 or 1.0 mg/kg/day bazedoxifene. They were compared with sham-ovariectomized rats subjected to hypertension and hemodynamic changes (HT rats). The vasoprotective effects of bazedoxifene and the mechanisms underlying its efficacy were analyzed.
Results: During 12 weeks of observation, the incidence of aneurysm rupture was 52% in ovariectomized rats. With no effect on the blood pressure, treatment with 0.3 or 1.0 mg/kg/day bazedoxifene lowered this rate to 11 and 17%, almost the same as in HT rats (17%). In ovariectomized rats, the mRNA level of ERα, ERβ, and the tissue inhibitor of metalloproteinase-2 was downregulated in the cerebral artery prone to rupture at 5 weeks after aneurysm induction; the mRNA level of interleukin-1β and the matrix metalloproteinase-9 was upregulated. In HT rats, bazedoxifene restored the mRNA level of ERα and ERβ and decreased the level of interleukin-1β and matrix metalloproteinase-9. These findings suggest that bazedoxifene was protective against aneurysmal rupture by alleviating the vascular inflammation and degradation exacerbated by the decrease in ERα and ERβ.
Conclusions: Our observation that bazedoxifene decreased the incidence of aneurysmal rupture in ovariectomized rats warrants further studies to validate this response in humans
Pillar[6]arene acts as a biosensor for quantitative detection of a vitamin metabolite in crude biological samples
ビタミン代謝物を迅速定量できる超分子バイオセンサーを開発. 京都大学プレスリリース. 2020-12-09.Metabolic syndrome is associated with obesity, hypertension, and dyslipidemia, and increased cardiovascular risk. Therefore, quick and accurate measurements of specific metabolites are critical for diagnosis; however, detection methods are limited. Here we describe the synthesis of pillar[n]arenes to target 1-methylnicotinamide (1-MNA), which is one metabolite of vitamin B3 (nicotinamide) produced by the cancer-associated nicotinamide N-methyltransferase (NNMT). We found that water-soluble pillar[5]arene (P5A) forms host–guest complexes with both 1-MNA and nicotinamide, and water-soluble pillar[6]arene (P6A) selectively binds to 1-MNA at the micromolar level. P6A can be used as a “turn-off sensor” by photoinduced electron transfer (detection limit is 4.38 × 10−6 M). In our cell-free reaction, P6A is used to quantitatively monitor the activity of NNMT. Moreover, studies using NNMT-deficient mice reveal that P6A exclusively binds to 1-MNA in crude urinary samples. Our findings demonstrate that P6A can be used as a biosensor to quantify 1-MNA in crude biological samples
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