174 research outputs found

    Phase diagram of the one dimensional anisotropic Kondo-necklace model

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    The one dimensional anisotropic Kondo-necklace model has been studied by several methods. It is shown that a mean field approach fails to gain the correct phase diagram for the Ising type anisotropy. We then applied the spin wave theory which is justified for the anisotropic case. We have derived the phase diagram between the antiferromagnetic long range order and the Kondo singlet phases. We have found that the exchange interaction (J) between the itinerant spins and local ones enhances the quantum fluctuations around the classical long range antiferromagnetic order and finally destroy the ordered phase at the critical value, J_c. Moreover, our results show that the onset of anisotropy in the XY term of the itinerant interactions develops the antiferromagnetic order for J<J_c. This is in agreement with the qualitative feature which we expect from the symmetry of the anisotropic XY interaction. We have justified our results by the numerical Lanczos method where the structure factor at the antiferromagnetic wave vector diverges as the size of system goes to infinity.Comment: 9 pages and 9 eps figure

    Effect of noscapine, the antitussive opioid alkaloid, on bradykinin-induced smooth muscle contraction in the isolated ileum of the guinea-pig

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    Bradykinin (BK) and related kinins are autocoid peptides that play integral roles in many pathophysiological processes such as cough. In this study, the inhibitory effect of noscapine, the antitussive opioid alkaloid, on BK receptors, was tested in the guinea-pig ileum. Contractions of the isolated ileum of the guinea-pig in response to BK were inhibited by noscapine (10–1000 nM) in a concentration-dependent manner. Concentration-response curves (CRCs) to BK were slightly shifted to the right with a concomitant decrease in the maximum effect. A pA2value of 6.68 was calculated for noscapine. The slope of the Schild plot of the antagonism was found to be 0.56. Noscapine had no effect on contractions induced by KCl, acetylcholine, histamine,5-hydroxy tryptamine or angiotensin II. In conclusion, noscapine has a specific antagonistic effect on BK receptors and the mode of inhibition was found to be non-competitive

    Effects of berberine on β-secretase activity in a rabbit model of Alzheimer's disease

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    Introduction: Relevant aspects of Alzheimer's disease (AD) can be modeled by aluminium-maltolate injection into specific regions of the brain. The possible role of berberine chloride (BC) as an anti-inflammatory agent in the brain has been previously addressed. Material and methods: Rabbits were divided into control (C), untreated lesion (L) and BC-treated + lesion (L + BC) groups. Animals in L + BC received BC (50 mg/ kg) orally 1 day after surgery and daily for 2 weeks. The lesion was induced by injection of 100 μu of either vehicle or water containing 25 mM aluminium-maltol into intraventricular fissure. Weight loss, ataxia, paralysis and tremor were monitored. For histopathology, Bielschowsky silver and H&E staining were employed. β-Secretase activity in hippocampus was finally assessed. Results: All L animals died on days 12-15 after lesion. Seven to 10 days after lesion, abnormal symptoms as well as cachexia were seen in over 90 of cases. L rabbits lost an average of 0.5 kg which was significant on days 10 and 12 (p < 0.05); this was not completely prevented by BC. Up to day 15, all L animals had lost their lives (p < 0.001). BC treatment protected the hippocampus from degeneration, altered the behavior and decreased the activity of β-site amyloid precursor protein cleaving enzyme-1 (BACE-1). Conclusions: Considering the findings in regard to physiological abilities, histological changes and BACE-1 activity in hippocampus changes, it is concluded that BC treatment could be an effective therapy in restoring Al maltol-induced behavioral derangements in the rabbit model of AD. © 2013 Termedia & Banach

    Apoptotic pathway induced by noscapine in human myelogenous leukemic cells

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    It has been shown that noscapine, an opium-derived phthalideisoquinoline alkaloid that is currently being used as an oral antitussive drug, induces apoptosis in myeloid leukemia cells. The molecular mechanism responsible for the anticancer effects of noscapine is poorly understood. In the current study, the apoptotic effects of noscapine on two myeloid cell lines, apoptosis-proficient HL60 cells and apoptosis-resistant K562 cells, were analyzed. An increase in the activity of caspase-2, -3, -6, -8 and -9, poly(ADP ribose) polymerase cleavage, detection of phosphatidylserine on the outer layer of the cell membrane, nucleation of chromatin, and DNA fragmentation suggested the induction of apoptosis. Noscapine increased the Bax/Bcl-2 ratio with a significant decrease of Bcl-2 expression accompanied with Bcl-2 phosphorylation. Using an inhibitory approach, the activation of the caspase cascade involved in the noscapine-induced apoptosis was analyzed. We observed no inhibitory effect of the caspase-8 inhibitor on caspase-9 activity. In view of these results and taking into consideration that K562 cells are Fas-null, we suggested that caspase-8 is activated in a Fas-independent manner downstream of caspase-9. In conclusion, noscapine can induce apoptosis in both apoptosis-proficient and apoptosis-resistant leukemic cells, and it can be a novel candidate in the treatment of hematological malignancies. © 2007 Lippincott Williams & Wilkins, Inc

    Xanthomicrol is the main cytotoxic component of Dracocephalum kotschyii and a potential anti-cancer agent

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    Spinal-Z, a methanolic mixture of dried powdered seeds of Peganum harmala Linn. and leaf of Dracocephalum kotschyii Boiss. is an Iranian ethno-medical remedy. It has been used for the treatment of various types of cancer for many years. To evaluate the use of Spinal-Z in treatment of cancer, we examined its effects against a panel of malignant cell lines and tumors induced in mice. The in vitro antiproliferative activities of Spinal-Z, the seed extract of P. harmala and the leaf extract of D. kotschyii were determined using the MTT assay. The concentration of the agent required to inhibit cell growth by 50 (IC50) was estimated. In addition, the anti-tumor activities of the remedy and its constituents were investigated. Viability of cells treated with Spinal-Z and its components decreased in a dose dependent manner. Spinal-Z and its components showed cytotoxic effects against all cell lines tested. The leaf extract of D. kotschyii showed a greater preferential cytotoxic effect than the seed extract of P. harmala and Spinal-Z, on all cell lines tested. Harmine showed cytotoxicity against HL60 and K562 cell lines. This could explain the cytotoxic effect of P. harmala on these cells. The leaf extract of D. kotschyii was able to inhibit tumor proliferation in mice. The active ingredient in the leaf extract of D. kotschyii appears to be a flavone identified as xanthomicrol. Xanthomicrol was able to inhibit proliferation of a number of malignant cells. The cytotoxic effects of xanthomicrol were more selective towards malignant cells than doxorubicin. © 2005 Elsevier Ltd. All rights reserved

    Effects of mebudipine and dibudipine, two new calcium channel blockers on voltage-activated calcium currents of PC12 cells

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    Mebudipine and dibudipine are two newly synthesized dihydropyridine (DHP) calcium channel blockers that have been shown to have considerable relaxant effects on vascular and atrial smooth muscle. The in vitro half-lives of mebudipine and dibudipine are reported to be significantly longer than that of nifedipine. In this study, we investigated the effects of mebudipine and dibudipine on voltage-activated Ca2+ channels on differentiated PC12 cells and compared their potencies to amlodipine. Our results point to absence of voltage-activated Ca2+ currents in undifferentiated PC12 cells. It is also concluded that mebudipine and dibudipine, like amlodipine are L-type calcium channel blockers. When tested in a range of 10-100 μM, mebudipine is at least as potent as amlodipine in inhibition of peak Ba2+ currents in differentiated PC12 cells while dibudipine is significantly less potent compared to amlodipine and mebudipine. © 2007 Akadémiai Kiadó, Budapest

    Sustainable and Regenerative Development of Water Mills as an Example of Agricultural Technologies for Small Farms

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    Nowadays, the reuse of built agricultural/industrial heritage has been a common practice worldwide. These structures represent excellent symbols of the great agricultural/industrial past. These agricultural/hydro-technologies also serve as monuments of socio-cultural identities, especially in rural areas and on small farms. One example of a successful application of agricultural technologies for small farms is the water mill. By harnessing the water energy, they were used for traditional flour and other goods production (e.g., olive oil) and works requiring energy, with the main role in the evolution of the traditional/cultural landscape. Water mills have been used to drive a mechanical process of milling, hammering, and rolling and are a portion of the agricultural, cultural, and industrial heritage. For approximately two millennia, the vertical mill water wheel prepared the initial source of mechanical power in many regions of the world. Water mills were the first device that converted natural resources of energy into mechanical energy in order to operate some form of machinery. The preservation/management of water mills is challenging due to their long-term abandonment and the lack of information/knowledge about their value. The other obstacles that are faced in their retrofitting and/or preservation are the lack of sufficient economic incentives and complex authorizations/legislations. Sustainability and regeneration of water mills through the centuries are then reviewed for history and agricultural/industrial “archaeology”. The history of water-powered mills in prehistoric and historic times, including ancient Persia/Iran, ancient China, ancient India, the Islamic world, Venetian Crete, medieval Europe, America, and finally present times, is discussed. The outcome of this review allows the understanding of the importance of conservation, optimization, and development of water mills. It will help to know more and achieve sustainable/regenerative development for small farms with respect to water and energy crises at present and in the future

    The effect of noscapine on oxygen-glucose deprivation on primary murine cortical neurons in high glucose condition

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    In the present work we set out to investigate the neuroprotective effects of noscapine (0.52 µM) in presence of D-glucose on primary murine foetal cortical neurons after oxygen� glucose deprivation/24 h. recovery. Cell viability, nitric oxide production and intracellular calcium ((ca2+)i) levels were evaluated by MTT assay, the modified Griess method and Fura-2 respectively. 25 and 100 mM D-glucose could, in a concentration dependent manner, improve cell viability and decrease NO production and (ca2+)i level in neuronal cells after ischemic insult. Moreover, pre-incubation of cells with noscapine, noticeably enhanced protective effects of 25 and 100 mM D-glucose compared to similar conditions without noscapine pretreatment. In fact, noscapine attenuated NO production in a dose-dependent fashion, after 30 minutes (min) OGD, during high-glucose (HG) condition in cortical neurons. Pretreatment with 2 μM noscapine and 25 or 100 mM D-glucose, was shown to decrease the rise in (ca2+) induced by Sodium azide/glucose deprivation (chemical OGD) model. These effects were morei pronounced than that of 25 or 100 mM D-glucose alone. The present study demonstrated that the neuroprotective effects of HG before an ischemic insult were augmented by pre-treatment with noscapine. Our results also suggested that the neuroprotection offered by both HG and noscapine involve attenuation of NO production and (ca2+)i levels stimulated by the experimental ischemia in cortical neurons. © 2016 by School of Pharmacy
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