37 research outputs found

    Coexistence of the spin-density-wave and superconductivity in the (Ba,K)Fe2As2

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    The relation between the spin-density-wave (SDW) and superconducting order is a central topic in current research on the FeAs-based high Tc superconductors. Conflicting results exist in the LaFeAs(O,F)-class of materials, for which whether the SDW and superconductivity are mutually exclusive or they can coexist has not been settled. Here we show that for the (Ba,K)Fe2As2 system, the SDW and superconductivity can coexist in an extended range of compositions. The availability of single crystalline samples and high value of the energy gaps would make the materials a model system to investigate the high Tc ferropnictide superconductivity.Comment: 4 pages, 5 figure

    Melatonin the "light of night" in human biology and adolescent idiopathic scoliosis

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    Melatonin "the light of night" is secreted from the pineal gland principally at night. The hormone is involved in sleep regulation, as well as in a number of other cyclical bodily activities and circadian rhythm in humans. Melatonin is exclusively involved in signalling the 'time of day' and 'time of year' (hence considered to help both clock and calendar functions) to all tissues and is thus considered to be the body's chronological pacemaker or 'Zeitgeber'. The last decades melatonin has been used as a therapeutic chemical in a large spectrum of diseases, mainly in sleep disturbances and tumours and may play a role in the biologic regulation of mood, affective disorders, cardiovascular system, reproduction and aging. There are few papers regarding melatonin and its role in adolescent idiopathic scoliosis (AIS). Melatonin may play a role in the pathogenesis of scoliosis (neuroendocrine hypothesis) but at present, the data available cannot clearly support this hypothesis. Uncertainties and doubts still surround the role of melatonin in human physiology and pathophysiology and future research is needed

    Circannual variation in the expression of beta 2-adrenoceptors on human peripheral mononuclear leukocytes (MNLs)

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    Peripheral mononuclear leukocytes (MNLs) are widely used as a tissue model in studies of beta-adrenoceptor disturbances in hypertension and asthmatic diseases. The beta 2-adrenoceptor density (Bmax), however, depends not only on the gender of the person under study and on the time of day the blood specimens are obtained. Evidence is now reported for a circannual variation in the expression of beta 2-adrenoceptor sites on peripheral MNLs. In male volunteers the 24-h mean was found to be highest in the men studied in April/May (1135 +/- 10 sites/cell) and decreased to 891 +/- 16 sites/cell in August and to 712 +r90 sites/cell in December (means +/- SE, P less than 0.01 April/May compared to December). Concomitantly the circadian amplitude increased from 17.3% +/- 6.4% of 24-h mean in April/May to 28.2% +/- 1.4% of 24-h mean in August and to 34.2% +/- 4.2% of 24-h mean in December (means +/- SE, P less than 0.05, April/May compared to December). The circadian acrophase remained constant (190 degrees +/- 30 degrees equivalent to 12 h 40 min +/- 2 h 00 min, means +/- SE)

    Relative Positioning of Classical Benzodiazepines to the γ2 Subunit of GABA-A Receptors

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    GABAA receptors are the major inhibitory neurotransmitter receptors in the brain. Benzodiazepine exert their action via a high affinity-binding site at the α/γ subunit interface on some of these receptors. Diazepam has sedative, hypnotic, anxiolytic, muscle relaxant, and anticonvulsant effects. It acts by potentiating the current evoked by the agonist GABA. Understanding specific interaction of benzodiazepines in the binding pocket of different GABAA receptor isoforms might help to separate these divergent effects. As a first step, we characterized the interaction between diazepam and the major GABAA receptor isoform α1β2γ2. We mutated several amino acid residues on the γ2-subunit assumed to be located near or in the benzodiazepine binding pocket individually to cysteine and studied the interaction with three ligands that are modified with a cysteine-reactive isothiocyanate group (-NCS). When the reactive NCS group is in apposition to the cysteine residue this leads to a covalent reaction. In this way, three amino acid residues, γ2Tyr58, γ2Asn60, and γ2Val190 were located relative to classical benzodiazepines in their binding pocket on GABAA receptors.status: publishe

    Long-term safety and tolerability of entecavir in patients with chronic hepatitis B in the rollover study ETV-901

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    PubMed ID: 22233350Objective: To review long-term safety data from the rollover study ETV-901, focusing on adverse events (AEs) with a potential nucleos(t)ide association. Methods: The open-label study ETV-901 (AI463901) assessed the safety of entecavir in chronic hepatitis B patients who received entecavir, lamivudine or adefovir monotherapy in previous entecavir Phase II/III studies. Long-term cumulative safety results are based on reported AEs, regardless of causal relationship. Results: Median exposure to entecavir in study ETV-901 was 184 weeks. Commonly reported AEs (? 10%) were upper respiratory tract infection, headache and nasopharyngitis. Most AEs were mild to moderate; 203 (19%) patients reported grade 3 4 AEs, with 45 (4%) considered related to entecavir. There were 14 (1%) discontinuations due to AEs. On-treatment alanine aminotransferase (ALT) flares were reported in 32 (3%) patients and were associated with a reduction in hepatitis B virus DNA of more than 2 log10 copies/ml in 25/32 patients. AEs potentially associated with nucleos(t)ide analogs were infrequent, the most common being myalgia (n = 54; 5%) and neuropathy-related AEs (hypoparesthesia and hyperparesthesia, polyneuropathy; n = 42; 4%). Conclusions: Long-term administration of entecavir was associated with low rates of serious AEs, discontinuations due to AEs and ALT flares. AEs potentially associated with nucleos(t)ide use occurred at low rates. © 2012 Informa UK, Ltd.Gilead Sciences Novartis Pharma Novartis Bristol-Myers Squibb Merck GlaxoSmithKline, GSK Roche Bristol-Myers SquibbThe study was sponsored by Bristol-Myers Squibb. The sponsor designed the study in collaboration with expert hepatologists. The sponsor also collected the data, monitored study conduct, performed the statistical analyses and coordinated writing of the article with all authors. Medical writing assistance was provided by Esther Race of ArticulateScience and was funded by Bristol-Myers Squibb. A Pangerl, S Beebe, M Yu and S Wongcharatrawee are employees of Bristol-Myers Squibb. MP Manns has received grant support, consulting fees or honorarium from Merck, Roche, Bristol-Myers Squibb, Gilead, Novartis, GlaxoSmithKline; he has received grants from Merck, Roche, Gilead, Novartis and -- Bristol-Myers Squibb and has received payment for development of educational presentations from Merck, Roche, Bristol-Myers Squibb, GlaxoSmithKline, Novartis and Gilead. TT Chang received consulting fees or honorarium from Bristol-Myers Squibb. N Tsai received research grant support, consulting fees or honorarium from Bristol-Myers Squibb, USA. W Sievert, SK Yoon and A Min have no conflicts of interest to declare. -
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