Beschreibung: Duchenne muscular dystrophy (DMD) is a disease of progressive destruction of striated muscle, resulting in muscle weakness with progressive respiratory and cardiac failure. Respiratory and cardiac disease are the leading causes of death in DMD patients. Previous studies have suggested an important link between cardiac dysfunction and hypoxia in the dystrophic heart; these studies aim to understand the mechanism underlying this connection. Here we demonstrate that anesthetized dystrophic mice display significant mortality following acute exposure to hypoxia. This increased mortality is associated with a significant metabolic acidosis, despite having significantly higher levels of arterial P o 2 . Chronic hypoxia does not result in mortality, but rather is characterized by marked cardiac fibrosis. Studies in isolated hearts reveal that the contractile function of dystrophic hearts is highly susceptible to short bouts of ischemia, but these hearts tolerate prolonged acidosis better than wild-type hearts, indicating an increased sensitivity of the dystrophic heart to hypoxia. Dystrophic hearts display decreased cardiac efficiency and oxygen extraction. Isolated dystrophic cardiomyocytes and hearts have normal levels of FCCP-induced oxygen consumption, and mitochondrial morphology and content are normal in the dystrophic heart. These studies demonstrate reductions in cardiac efficiency and oxygen extraction of the dystrophic heart. The underlying cause of this reduced oxygen extraction is not clear; however, the current studies suggest that large disruptions of mitochondrial respiratory function or coronary flow regulation are not responsible. This finding is significant, as hypoxia is a common and largely preventable component of DMD that may contribute to the progression of the cardiac disease in DMD patients.

Beschreibung: Disorders of the brain can exhibit considerable epidemiological comorbidity and often share symptoms, provoking debate about their etiologic overlap. We quantified the genetic sharing of 25 brain disorders from genome-wide association studies of 265,218 patients and 784,643 control participants and assessed their relationship to 17 phenotypes from 1,191,588 individuals. Psychiatric disorders share common variant risk, whereas neurological disorders appear more distinct from one another and from the psychiatric disorders. We also identified significant sharing between disorders and a number of brain phenotypes, including cognitive measures. Further, we conducted simulations to explore how statistical power, diagnostic misclassification, and phenotypic heterogeneity affect genetic correlations. These results highlight the importance of common genetic variation as a risk factor for brain disorders and the value of heritability-based methods in understanding their etiology.

Beschreibung: Recent advances in human brown adipose tissue (BAT) imaging technology have renewed interest in the identification of BAT activators for the treatment of obesity and diabetes. In uncontrolled diabetes (uDM), activation of BAT is implicated in glucose lowering mediated by intracerebroventricular (icv) administration of leptin, which normalizes blood glucose levels in streptozotocin (STZ)-induced diabetic rats. The potent effect of icv leptin to increase BAT glucose uptake in STZ-diabetes is accompanied by the return of reduced plasma thyroxine (T 4 ) levels and BAT uncoupling protein-1 ( Ucp1 ) mRNA levels to nondiabetic controls. We therefore sought to determine whether activation of thyroid hormone receptors is sufficient in and of itself to lower blood glucose levels in STZ-diabetes and whether this effect involves activation of BAT. We found that, although systemic administration of the thyroid hormone (TR)β-selective agonist GC-1 increases energy expenditure and induces further weight loss in STZ-diabetic rats, it neither increased BAT glucose uptake nor attenuated diabetic hyperglycemia. Even when GC-1 was administered in combination with a β 3 -adrenergic receptor agonist to mimic sympathetic nervous system activation, glucose uptake was not increased in STZ-diabetic rats, nor was blood glucose lowered, yet this intervention potently activated BAT. Similar results were observed in animals treated with active thyroid hormone (T 3 ) instead of GC-1. Taken together, our data suggest that neither returning normal plasma thyroid hormone levels nor BAT activation has any impact on diabetic hyperglycemia, and that in BAT, increases of Ucp1 gene expression and glucose uptake are readily dissociated from one another in this setting.

Beschreibung: Ice-nucleating organisms play important roles in the environment. With their ability to induce ice formation at temperatures just below the ice melting point, bacteria such as Pseudomonas syringae attack plants through frost damage using specialized ice-nucleating proteins. Besides the impact on agriculture and microbial ecology, airborne P. syringae can affect atmospheric glaciation processes, with consequences for cloud evolution, precipitation, and climate. Biogenic ice nucleation is also relevant for artificial snow production and for biomimetic materials for controlled interfacial freezing. We use interface-specific sum frequency generation (SFG) spectroscopy to show that hydrogen bonding at the water-bacteria contact imposes structural ordering on the adjacent water network. Experimental SFG data and molecular dynamics simulations demonstrate that ice-active sites within P. syringae feature unique hydrophilic-hydrophobic patterns to enhance ice nucleation. The freezing transition is further facilitated by the highly effective removal of latent heat from the nucleation site, as apparent from time-resolved SFG spectroscopy.

Beschreibung: High lethality rates associated with metastatic cancer highlight an urgent medical need for improved understanding of biologic mechanisms driving metastatic spread and identification of biomarkers predicting late-stage progression. Numerous neoplastic cell intrinsic and extrinsic mechanisms fuel tumor progression; however, mechanisms driving heterogeneity of neoplastic cells in solid tumors remain obscure. Increased mutational rates of neoplastic cells in stressed environments are implicated but cannot explain all aspects of tumor heterogeneity. We present evidence that fusion of neoplastic cells with leukocytes (for example, macrophages) contributes to tumor heterogeneity, resulting in cells exhibiting increased metastatic behavior. Fusion hybrids (cells harboring hematopoietic and epithelial properties) are readily detectible in cell culture and tumor-bearing mice. Further, hybrids enumerated in peripheral blood of human cancer patients correlate with disease stage and predict overall survival. This unique population of neoplastic cells provides a novel biomarker for tumor staging, as well as a potential therapeutic target for intervention.

Beschreibung: We introduce a spectroscopic method that determines nonlinear quantum mechanical response functions beyond the optical diffraction limit and allows direct imaging of nanoscale coherence. In established coherent two-dimensional (2D) spectroscopy, four-wave-mixing responses are measured using three ingoing waves and one outgoing wave; thus, the method is diffraction-limited in spatial resolution. In coherent 2D nanoscopy, we use four ingoing waves and detect the final state via photoemission electron microscopy, which has 50-nanometer spatial resolution. We recorded local nanospectra from a corrugated silver surface and observed subwavelength 2D line shape variations. Plasmonic phase coherence of localized excitations persisted for about 100 femtoseconds and exhibited coherent beats. The observations are best explained by a model in which coupled oscillators lead to Fano-like resonances in the hybridized dark- and bright-mode response.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Aeschlimann, Martin -- Brixner, Tobias -- Fischer, Alexander -- Kramer, Christian -- Melchior, Pascal -- Pfeiffer, Walter -- Schneider, Christian -- Struber, Christian -- Tuchscherer, Philip -- Voronine, Dmitri V -- New York, N.Y. -- Science. 2011 Sep 23;333(6050):1723-6. doi: 10.1126/science.1209206. Epub 2011 Aug 11.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Fachbereich Physik and Research Center OPTIMAS, Technische Universitat Kaiserslautern, Erwin-Schrodinger-Str. 46, 67663 Kaiserslautern, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21835982" target="_blank"〉PubMed〈/a〉

Beschreibung: Arthritis is a leading cause of disability, and when nonoperative methods have failed, a prosthetic implant is a cost-effective and clinically successful treatment. Metal-on-metal replacements are an attractive implant technology, a lower-wear alternative to metal-on-polyethylene devices. Relatively little is known about how sliding occurs in these implants, except that proteins play a critical role and that there is a tribological layer on the metal surface. We report evidence for graphitic material in the tribological layer in metal-on-metal hip replacements retrieved from patients. As graphite is a solid lubricant, its presence helps to explain why these components exhibit low wear and suggests methods of improving their performance; simultaneously, this raises the issue of the physiological effects of graphitic wear debris.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Liao, Y -- Pourzal, R -- Wimmer, M A -- Jacobs, J J -- Fischer, A -- Marks, L D -- 1RC2AR058993-01/AR/NIAMS NIH HHS/ -- New York, N.Y. -- Science. 2011 Dec 23;334(6063):1687-90. doi: 10.1126/science.1213902.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60201, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22194573" target="_blank"〉PubMed〈/a〉

Beschreibung: Genetic mutations cause primary immunodeficiencies (PIDs) that predispose to infections. Here, we describe activated PI3K-delta syndrome (APDS), a PID associated with a dominant gain-of-function mutation in which lysine replaced glutamic acid at residue 1021 (E1021K) in the p110delta protein, the catalytic subunit of phosphoinositide 3-kinase delta (PI3Kdelta), encoded by the PIK3CD gene. We found E1021K in 17 patients from seven unrelated families, but not among 3346 healthy subjects. APDS was characterized by recurrent respiratory infections, progressive airway damage, lymphopenia, increased circulating transitional B cells, increased immunoglobulin M, and reduced immunoglobulin G2 levels in serum and impaired vaccine responses. The E1021K mutation enhanced membrane association and kinase activity of p110delta. Patient-derived lymphocytes had increased levels of phosphatidylinositol 3,4,5-trisphosphate and phosphorylated AKT protein and were prone to activation-induced cell death. Selective p110delta inhibitors IC87114 and GS-1101 reduced the activity of the mutant enzyme in vitro, which suggested a therapeutic approach for patients with APDS.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3930011/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3930011/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Angulo, Ivan -- Vadas, Oscar -- Garcon, Fabien -- Banham-Hall, Edward -- Plagnol, Vincent -- Leahy, Timothy R -- Baxendale, Helen -- Coulter, Tanya -- Curtis, James -- Wu, Changxin -- Blake-Palmer, Katherine -- Perisic, Olga -- Smyth, Deborah -- Maes, Mailis -- Fiddler, Christine -- Juss, Jatinder -- Cilliers, Deirdre -- Markelj, Gasper -- Chandra, Anita -- Farmer, George -- Kielkowska, Anna -- Clark, Jonathan -- Kracker, Sven -- Debre, Marianne -- Picard, Capucine -- Pellier, Isabelle -- Jabado, Nada -- Morris, James A -- Barcenas-Morales, Gabriela -- Fischer, Alain -- Stephens, Len -- Hawkins, Phillip -- Barrett, Jeffrey C -- Abinun, Mario -- Clatworthy, Menna -- Durandy, Anne -- Doffinger, Rainer -- Chilvers, Edwin R -- Cant, Andrew J -- Kumararatne, Dinakantha -- Okkenhaug, Klaus -- Williams, Roger L -- Condliffe, Alison -- Nejentsev, Sergey -- 095198/Wellcome Trust/United Kingdom -- 095198/Z/10/Z/Wellcome Trust/United Kingdom -- 095691/Wellcome Trust/United Kingdom -- BB/J004456/1/Biotechnology and Biological Sciences Research Council/United Kingdom -- MC_U105184308/Medical Research Council/United Kingdom -- U105184308/Medical Research Council/United Kingdom -- New York, N.Y. -- Science. 2013 Nov 15;342(6160):866-71. doi: 10.1126/science.1243292. Epub 2013 Oct 17.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Medicine, University of Cambridge, Cambridge, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24136356" target="_blank"〉PubMed〈/a〉

Beschreibung: 〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4138491/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4138491/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉H3Africa Consortium -- Rotimi, Charles -- Abayomi, Akin -- Abimiku, Alash'le -- Adabayeri, Victoria May -- Adebamowo, Clement -- Adebiyi, Ezekiel -- Ademola, Adebowale D -- Adeyemo, Adebowale -- Adu, Dwomoa -- Affolabi, Dissou -- Agongo, Godfred -- Ajayi, Samuel -- Akarolo-Anthony, Sally -- Akinyemi, Rufus -- Akpalu, Albert -- Alberts, Marianne -- Alonso Betancourt, Orlando -- Alzohairy, Ahmed Mansour -- Ameni, Gobena -- Amodu, Olukemi -- Anabwani, Gabriel -- Andersen, Kristian -- Arogundade, Fatiu -- Arulogun, Oyedunni -- Asogun, Danny -- Bakare, Rasheed -- Balde, Naby -- Baniecki, Mary Lynn -- Beiswanger, Christine -- Benkahla, Alia -- Bethke, Lara -- Boehnke, Micheal -- Boima, Vincent -- Brandful, James -- Brooks, Andrew I -- Brosius, Frank C -- Brown, Chester -- Bucheton, Bruno -- Burke, David T -- Burnett, Barrington G -- Carrington-Lawrence, Stacy -- Carstens, Nadia -- Chisi, John -- Christoffels, Alan -- Cooper, Richard -- Cordell, Heather -- Crowther, Nigel -- Croxton, Talishiea -- de Vries, Jantina -- Derr, Leslie -- Donkor, Peter -- Doumbia, Seydou -- Duncanson, Audrey -- Ekem, Ivy -- El Sayed, Ahmed -- Engel, Mark E -- Enyaru, John C K -- Everett, Dean -- Fadlelmola, Faisal M -- Fakunle, Eyitayo -- Fischbeck, Kenneth H -- Fischer, Anne -- Folarin, Onikepe -- Gamieldien, Junaid -- Garry, Robert F -- Gaseitsiwe, Simani -- Gbadegesin, Rasheed -- Ghansah, Anita -- Giovanni, Maria -- Goesbeck, Parham -- Gomez-Olive, F Xavier -- Grant, Donald S -- Grewal, Ravnit -- Guyer, Mark -- Hanchard, Neil A -- Happi, Christian T -- Hazelhurst, Scott -- Hennig, Branwen J -- Hertz-, Christiane -- Fowler -- Hide, Winston -- Hilderbrandt, Friedhelm -- Hugo-Hamman, Christopher -- Ibrahim, Muntaser E -- James, Regina -- Jaufeerally-Fakim, Yasmina -- Jenkins, Carolyn -- Jentsch, Ute -- Jiang, Pan-Pan -- Joloba, Moses -- Jongeneel, Victor -- Joubert, Fourie -- Kader, Mukthar -- Kahn, Kathleen -- Kaleebu, Pontiano -- Kapiga, Saidi H -- Kassim, Samar Kamal -- Kasvosve, Ishmael -- Kayondo, Jonathan -- Keavney, Bernard -- Kekitiinwa, Adeodata -- Khan, Sheik Humarr -- Kimmel, Paul -- King, Mary-Claire -- Kleta, Robert -- Koffi, Mathurin -- Kopp, Jeffrey -- Kretzler, Matthias -- Kumuthini, Judit -- Kyobe, Samuel -- Kyobutungi, Catherine -- Lackland, Daniel T -- Lacourciere, Karen A -- Landoure, Guida -- Lawlor, Rita -- Lehner, Thomas -- Lesosky, Maia -- Levitt, Naomi -- Littler, Katherine -- Lombard, Zane -- Loring, Jeanne F -- Lyantagaye, Sylvester -- Macleod, Annette -- Madden, Ebony B -- Mahomva, Chengetai R -- Makani, Julie -- Mamven, Manmak -- Marape, Marape -- Mardon, Graeme -- Marshall, Patricia -- Martin, Darren P -- Masiga, Daniel -- Mason, Robin -- Mate-Kole, Michael -- Matovu, Enock -- Mayige, Mary -- Mayosi, Bongani M -- Mbanya, Jean Claude -- McCurdy, Sheryl A -- McCarthy, Mark I -- McIlleron, Helen -- Mc'Ligeyo, S O -- Merle, Corrine -- Mocumbi, Ana Olga -- Mondo, Charles -- Moran, John V -- Motala, Ayesha -- Moxey-Mims, Marva -- Mpoloka, Wata Sununguko -- Msefula, Chisomo L -- Mthiyane, Thuli -- Mulder, Nicola -- Mulugeta, Gebregziab her -- Mumba, Dieuodonne -- Musuku, John -- Nagdee, Mo -- Nash, Oyekanmi -- Ndiaye, Daouda -- Nguyen, Anh Quynh -- Nicol, Mark -- Nkomazana, Oathokwa -- Norris, Shane -- Nsangi, Betty -- Nyarko, Alexander -- Nyirenda, Moffat -- Obe, Eileen -- Obiakor, Reginald -- Oduro, Abraham -- Ofori-Acquah, Solomon F -- Ogah, Okechukwu -- Ogendo, Stephen -- Ohene-Frempong, Kwaku -- Ojo, Akinlolu -- Olanrewaju, Timothy -- Oli, John -- Osafo, Charlotte -- Ouwe Missi Oukem-Boyer, Odile -- Ovbiagele, Bruce -- Owen, Andrew -- Owolabi, Mayowa Ojo -- Owolabi, Lukman -- Owusu-Dabo, Ellis -- Pare, Guillaume -- Parekh, Rulan -- Patterton, Hugh G -- Penno, Margaret B -- Peterson, Jane -- Pieper, Rembert -- Plange-Rhule, Jacob -- Pollak, Martin -- Puzak, Julia -- Ramesar, Rajkumar S -- Ramsay, Michele -- Rasooly, Rebekah -- Reddy, Shiksha -- Sabeti, Pardis C -- Sagoe, Kwamena -- Salako, Tunde -- Samassekou, Oumar -- Sandhu, Manjinder S -- Sankoh, Osman -- Sarfo, Fred Stephen -- Sarr, Marie -- Shaboodien, Gasnat -- Sidibe, Issa -- Simo, Gustave -- Simuunza, Martin -- Smeeth, Liam -- Sobngwi, Eugene -- Soodyall, Himla -- Sorgho, Hermann -- Sow Bah, Oumou -- Srinivasan, Sudha -- Stein, Dan J -- Susser, Ezra S -- Swanepoel, Carmen -- Tangwa, Godfred -- Tareila, Andrew -- Tastan Bishop, Ozlem -- Tayo, Bamidele -- Tiffin, Nicki -- Tinto, Halidou -- Tobin, Ekaete -- Tollman, Stephen Meir -- Traore, Mahamadou -- Treadwell, Marsha J -- Troyer, Jennifer -- Tsimako-Johnstone, Masego -- Tukei, Vincent -- Ulasi, Ifeoma -- Ulenga, Nzovu -- van Rooyen, Beverley -- Wachinou, Ablo Prudence -- Waddy, Salina P -- Wade, Alisha -- Wayengera, Misaki -- Whitworth, James -- Wideroff, Louise -- Winkler, Cheryl A -- Winnicki, Sarah -- Wonkam, Ambroise -- Yewondwos, Mengistu -- sen, Tadase -- Yozwiak, Nathan -- Zar, Heather -- 085349/Wellcome Trust/United Kingdom -- 095009/Wellcome Trust/United Kingdom -- 095201/Wellcome Trust/United Kingdom -- 098504/Wellcome Trust/United Kingdom -- 104111/Wellcome Trust/United Kingdom -- MC_U123292700/Medical Research Council/United Kingdom -- P20 MD006899/MD/NIMHD NIH HHS/ -- R01 AI104621/AI/NIAID NIH HHS/ -- RG/08/012/25941/British Heart Foundation/United Kingdom -- U01 HG007044/HG/NHGRI NIH HHS/ -- U41 HG006941/HG/NHGRI NIH HHS/ -- U54 AI110398/AI/NIAID NIH HHS/ -- U54 HG006938/HG/NHGRI NIH HHS/ -- U54 HG006939/HG/NHGRI NIH HHS/ -- U54 HG007479/HG/NHGRI NIH HHS/ -- UH2 HG007051/HG/NHGRI NIH HHS/ -- New York, N.Y. -- Science. 2014 Jun 20;344(6190):1346-8. doi: 10.1126/science.1251546.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24948725" target="_blank"〉PubMed〈/a〉