62,767 research outputs found
A new approach to detect and study ion channel formation in microBLMs
No full textIn this paper, an innovative and versatile approach to detect pore formation in microBLMs and to investigate their ion selectivity is described. For the first time, both electrochemical impedance spectroscopy and conductivity measurements are performed on the same membrane, providing a simple, long-lasting and cheap method which can find applications in various ion channel-involving research fields. We make use of this improved experimental procedure to obtain for the first time a range of values to characterize homogeneous polycarbonate-supported microBLMs. To test the validity of our method, the well-known. channel-forming peptide gramicidin D was first employed. Then, we applied our approach to the study of the still unclear membrane interaction mechanisms of the peptides trichogin GA IV and phospholamban, finding that both can form ion channels in biomimetic models. The phospholamban-generated ion channels could be a promising therapeutic target in heart failures and other cardiac diseases. Our methodology might also be useful for detecting new drugs with ion-channel blocking action. (C) 2011 Elsevier B.V. All rights reserved
Ivabradine, coronary artery disease, and heart failure: beyond rhythm control
No full textPietro Scicchitano,1 Francesca Cortese,1 Gabriella Ricci,1 Santa Carbonara,1 Michele Moncelli,1 Massimo Iacoviello,1 Annagrazia Cecere,1 Michele Gesualdo,1 Annapaola Zito,1 Pasquale Caldarola,2 Domenico Scrutinio,3 Rocco Lagioia,3 Graziano Riccioni,4 Marco Matteo Ciccone1 1Section of Cardiovascular Diseases, Department of Emergency and Organ Transplantation, University of Bari, School of Medicine, Policlinico, Bari, Italy; 2Section of Cardiovascular Diseases, Policlinic, San Paolo Hospital, Bari, Italy; 3Section of Cardiovascular Diseases, Fondazione Maugeri, Cassano Murge, Italy; 4Intensive Cardiology Care Unit, San Camillo de Lellis Hospital, Manfredonia, Foggia, Italy Abstract: Elevated heart rate could negatively influence cardiovascular risk in the general population. It can induce and promote the atherosclerotic process by means of several mechanisms involving endothelial shear stress and biochemical activities. Furthermore, elevated heart rate can directly increase heart ischemic conditions because of its skill in unbalancing demand/supply of oxygen and decreasing the diastolic period. Thus, many pharmacological treatments have been proposed in order to reduce heart rate and ameliorate the cardiovascular risk profile of individuals, especially those suffering from coronary artery diseases (CAD) and chronic heart failure (CHF). Ivabradine is the first pure heart rate reductive drug approved and currently used in humans, created in order to selectively reduce sinus node function and to overcome the many side effects of similar pharmacological tools (ie, β-blockers or calcium channel antagonists). The aim of our review is to evaluate the role and the safety of this molecule on CAD and CHF therapeutic strategies. Keywords: chronic heart failure, heart rate reduction, cardiac ischemic disease, heart-rate lowering drugs, funny curren
A Peptide-tethered Lipid Bilayer on Mercury as a Biomimetic System
No full textA novel spacer consisting of a hexapeptide molecule with a high tendency to form a 310-helical structure, which terminates with a sulfydryl group for anchoring to a metal, was tailored for use as a tethered hydrophilic spacer to be interposed between a metal support and a lipid bilayer. The thiol peptide has two triethylenoxy side chains that impart it a satisfactory hydrophilicity and are intended to keep the anchored thiol peptide chains sufficiently apart so as to accommodate water molecules and inorganic ions and to create a suitable environment for the incorporation of integral proteins. This thiol peptide was anchored to a hanging mercury drop electrode. The formation of a phospholipid bilayer on top of the self-assembled thiol peptide was carried out by a novel procedure which exploits the spontaneous tendency of a lipid film to form a bilayer when interposed between two hydrophilic phases. The resulting mercury-supported thiol peptide/lipid bilayer system was characterized by ac voltammetry with phase resolution, chronocoulometry, and impedance spectroscopy. The suitability of this tethered film as a biomembrane model was tested by incorporating ubiquinone-10 and valinomycin
Electrochemical and photoelectrochemical behavior of chlorophyll a films adsorbed on mercury
No full textA Novel Cardiac Bio-Marker: ST2: A Review
No full textCardiovascular diseases (CVD) are the major cause of death worldwide. The identification of markers able to detect the early stages of such diseases and/or their progression is fundamental in order to adopt the best actions in order to reduce the worsening of clinical condition. Brain natriuretic peptide (BNP) and NT-proBNP are the best known markers of heart failure (HF), while troponins ameliorated the diagnosis of acute and chronic coronary artery diseases. Nevertheless, many limitations reduce their accuracy. Physicians have tried to develop further detectable molecules in order to improve the detection of the early moments of CVD and prevent their development. Soluble ST2 (suppression of tumorigenicity 2) is a blood protein confirmed to act as a decoy receptor for interleukin-33. It seems to be markedly induced in mechanically overloaded cardiac myocytes. Thus, HF onset or worsening of a previous chronic HF status, myocardial infarct able to induce scars that make the myocardium unable to stretch well, etc, are all conditions that could be detected by measuring blood levels of soluble ST2. The aim of this review is to explore the possible role of ST2 derived-protein as an early marker of cardiovascular diseases, above all in heart failure and ischemic heart diseases
Thermal expansion anomalies of R(Fe, M)(12) (R=Y, Nd; M=Mo and Si)
No full textStructural and thermal-expansion anomaly studies on R(Fe,M)(12) (R=Nd and and Y, M=Mo and Si) compounds were performed by x-ray diffraction. Mo atoms occupy the 8i site. While Si atoms occupy the 8f and 8j sites but not the 8i site. Thermal-expansion anomaly shows only in ab plane in the Mo compounds, while becomes very weak and along with only the c axis in the Si compounds. The anomaly was attributed to the contribution of the interactions of short Fe-Fe distances similar to the previous explanation on other R-Fe intermetallics and that of other strongly positive interactions such as 8j-8j. (c) 2005 American Institute of Physics.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000230168300025&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Physics, AppliedSCI(E)EICPCI-S(ISTP)
Letter from Thomas R. Bodine, American Friends Service Committee Seattle office, to Mary M. Kimber, May 25, 1942
No full textLetter from Thomas R. Bodine to Mary M. Kimber, asking Kimber to visit individuals from the Puget Sound area incarcerated at Pinedale Assembly Center: Rev. Daisuke Kitigawa, Waichi Oyanagi, Chisako Higuchi, Mutsuo Hasiguchi and Mrs. Matsuoka, Makato Kobukata, the Hirabayashi family, and Violet Yokoyama. A note in pencil at the top of the page: "Burcham." A response letter from Grace and Calvin Coke to Thomas R. Bodine is found in item: chs_ms840_0306.Personal correspondence, organizational records, government documents, publications, and other papers created or collected by Joseph R. Goodman documenting the forced removal and incarceration of Japanese Americans during World War II, as well as organized resistance to incarceration. Included in the collection are records of the Japanese Young Men's Christian Association and the Japanese American Citizens' League in San Francisco, including papers of the Japanese YMCA's executive secretary Lincoln Kanai; Sakai family papers; Goodman's correspondence to and from Japanese American incarcerees, organizations opposing forced removal and incarceration of Japanese Americans, the War Relocation Authority, and others; publications, photographs, and ephemera from the Topaz Relocation Center, where Goodman taught high school; War Relocation Authority records and publications; and newspaper clippings, pamphlets, and reports about forced removal and incarceration created by various government, religious, and civic organizations, in California and nationwide
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
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