Read by QxMD icon Read


Andreas Benedikt Weins, Tilo Biedermann, Tina Weiss, Johannes Martin Weiss
Das Wells-Syndrom, auch als eosinophile Zellulitis bezeichnet, ist eine seltene, sporadisch auftretende eosinophile Dermatose mit polymorphem klinischem Bild. Als typisch gelten entzündliche Erytheme oder Plaques an den Extremitäten, die initial als Erysipel imponieren können, unter antimikrobieller Behandlung aber persistieren. Die eosinophile Zellulitis ist eine Ausschlussdiagnose, die in Zusammenschau von klinischem Befund und charakteristischem histologischem Bild (Flammenfiguren) nur im Verlauf gestellt werden kann...
October 2016: Journal der Deutschen Dermatologischen Gesellschaft, Journal of the German Society of Dermatology: JDDG
Shang-Chun Guo, Shi-Cong Tao, Wen-Jing Yin, Xin Qi, Jia-Gen Sheng, Chang-Qing Zhang
Osteonecrosis of the femoral head (ONFH) represents a debilitating complication following glucocorticoid (GC)-based therapy. Synovial-derived mesenchymal stem cells (SMSCs) can exert protective effect in the animal model of GC-induced ONFH by inducing cell proliferation and preventing cell apoptosis. Recent studies indicate the transplanted cells exert therapeutic effects primarily via a paracrine mechanism and exosomes are an important paracrine factor that can be directly used as therapeutic agents for tissue engineering...
2016: International Journal of Biological Sciences
Ariel Lewis-Ballester, Farhad Forouhar, Sung-Mi Kim, Scott Lew, YongQiang Wang, Shay Karkashon, Jayaraman Seetharaman, Dipanwita Batabyal, Bing-Yu Chiang, Munif Hussain, Maria Almira Correia, Syun-Ru Yeh, Liang Tong
Tryptophan 2,3-dioxygenase (TDO) and indoleamine 2,3-dioxygenase (IDO) play a central role in tryptophan metabolism and are involved in many cellular and disease processes. Here we report the crystal structure of human TDO (hTDO) in a ternary complex with the substrates L-Trp and O2 and in a binary complex with the product N-formylkynurenine (NFK), defining for the first time the binding modes of both substrates and the product of this enzyme. The structure indicates that the dioxygenation reaction is initiated by a direct attack of O2 on the C2 atom of the L-Trp indole ring...
October 20, 2016: Scientific Reports
Sayantan Maji, Pankaj Chaudhary, Irina Akopova, Phung M Nguyen, Richard J Hare, Ignacy Gryczynski, Jamboor K Vishwanatha
: Tumor-derived exosomes are emerging mediators of tumorigenesis and tissue-specific metastasis. Proteomic profiling has identified Annexin A2 as one of the most highly expressed proteins in exosomes; however, studies focused on the biological role of exosomal-AnnexinA2 (exo-AnxA2) are still lacking. In this study, mechanistic insight was sought regarding exo-AnxA2 and its function in angiogenesis and breast cancer metastasis. Multiple in vitro and in vivo techniques were used to study the role of exo-AnxA2 in angiogenesis...
October 19, 2016: Molecular Cancer Research: MCR
Melissa Agnello, Steven E Finkel, Annie Wong-Beringer
Fluoroquinolone (FQ) resistance is highly prevalent among clinical strains of Pseudomonas aeruginosa, limiting treatment options. We have reported previously that highly virulent strains containing the exoU gene of the type III secretion system are more likely to be FQ-resistant than strains containing the exoS gene, as well as more likely to acquire resistance-conferring mutations in gyrA/B and parC/E. We hypothesize that FQ-resistance imposes a lower fitness cost on exoU compared to exoS strains, thus allowing for better adaptation to the FQ-rich clinical environment...
2016: Frontiers in Microbiology
Tao Song, Hui Xu, Congchong Wei, Tengfei Jiang, Shishang Qin, Weijia Zhang, Yu Cao, Chao Hu, Fan Zhang, Dairong Qiao, Yi Cao
Seaweed is receiving an increasing amount of attention as a "sea vegetable". The microbiota of coastal populations may acquire seaweed associated enzymes through marine food. Several agarases have been found in non-marine environments; however, their origin is unknown. In this study, a hypothetical protein, Aga1, was identified as an agarase from an inland soil agar-degrading bacterium, Paenibacillus sp. SSG-1.Having low similarity to known glycoside hydrolases, Aga1 may be a distant member of the glycoside hydrolase family 86...
October 19, 2016: Scientific Reports
Weiqiang Chen, Weili An, Yongjian Wang, Ao Yu
The detailed mechanism of the cyanide catalyzed synthesis of benzoxazole from 2-aminophenol and benzaldehyde was investigated in depth using Density Functional Theory (DFT). The metal-free aerobic oxidative process as well as the dehydrogenation detail was examined and described. Cyanide anion was proved to assist the oxygen atoms to undergo an aerobic dehydrogenation rather than direct cyclization which was predicted according to Baldwin's 5-exo-tet rule. The dehydrogenation pathway was thermodynamically favored over cyclization with an activation energy difference of 24...
October 18, 2016: Journal of Organic Chemistry
Bernd Schmidt, Felix Wolf, Christopher Ehlert
alpha-Methylene-gamma-butyrolactone and alpha-methylene-delta-valerolactone undergo Pd-catalyzed Matsuda-Heck couplings with arene diazonium salts to alpha-benzyl butenolides or pentenolides, respectively, or to alpha-benzylidene lactones. The observed regioselectivity is strongly ring size dependent, with six-membered rings giving exclusively alpha-benzyl pentenolides, whereas the fivemembered alpha-methylene lactone reacts to mixtures of regioisomers with a high proportion of E-alpha-benzylidene-gamma-butyrolactones...
October 17, 2016: Journal of Organic Chemistry
Jing-Kai Huang, Ying-Chieh Wong, Tzu-Ting Kao, Chen-Tso Tseng, Kak-Shan Shia
A new NHPI/Co(II)-catalyzed protocol, mechanistically involving a sequence of alpha-hydrogen abstraction, 5-exo-dig cyclization, oxygen capture, hydrogen transfer and 1,4-dehydration, has been developed to facilitate aerobic oxidation of aryl-, silyl- and alkyl-capped alkynyl alpha-cyano alkanone systems, respectively, to the corresponding highly functionalized products in an effective manner, thus turning this novel chain reaction, originally occurring spontaneously in low yields, into a practical methodology...
October 17, 2016: Journal of Organic Chemistry
Weichao Xue, Zheng-Wang Qu, Stefan Grimme, Martin Oestreich
A copper-catalyzed C(sp3)-Si cross-coupling of aliphatic C(sp3)-I electrophiles using an Si-B reagent as the silicon pronucleophile is reported. The reaction involves an alkyl radical intermediate that also engages in 5-exo-trig ring closures onto pendant alkenes prior to the terminating C(sp3)-Si bond formation. Several Ueno-Stork-type precursors cyclized with excellent diastereocontrol in good yields. The base-mediated release of the silicon nucleophile and the copper-catalyzed radical process are analyzed by quantum-chemical calculations, leading to a full mechanistic picture...
October 16, 2016: Journal of the American Chemical Society
Sirilak Baramee, Thitiporn Teeravivattanakit, Paripok Phitsuwan, Rattiya Waeonukul, Patthra Pason, Chakrit Tachaapaikoon, Akihiko Kosugi, Kazuo Sakka, Khanok Ratanakhanokchai
We recently discovered a novel glycoside hydrolase family 6 (GH6) cellobiohydrolase from Paenibacillus curdlanolyticus B-6 (PcCel6A), which is rarely found in bacteria. This enzyme is a true exo-type cellobiohydrolase which exhibits high substrate specificity on amorphous cellulose and low substrate specificity on crystalline cellulose, while this showed no activity on substitution substrates, carboxymethyl cellulose and xylan, distinct from all other known GH6 cellobiohydrolases. Product profiles, HPLC analysis of the hydrolysis products and a schematic drawing of the substrate-binding subsites catalysing cellooligosaccharides can explain the new mode of action of this enzyme which prefers to hydrolyse cellopentaose...
October 14, 2016: Applied Microbiology and Biotechnology
Sen Wang, Dong Zhao, Xinfeng Bai, Weican Zhang, Xuemei Lu
: Cytophaga hutchinsonii is a gram-negative bacterium which can efficiently degrade crystalline cellulose by a unique mechanism different from free cellulases or cellulosomes strategy. In this study, chu_3220, encoding a hypothetical protein CHU_3220 (205 kDa), was identified by insertional mutation and gene deletion to be the first gene essential for degradation of crystalline region but not amorphous region of cellulose by C. hutchinsonii chu_3220-deletion mutant was defective in degradation of crystalline cellulose and increased the degree of crystallinity of Avicel PH101, but could still degrade amorphous cellulose completely...
October 14, 2016: Applied and Environmental Microbiology
Guoyin Yin, Xin Mu, Guosheng Liu
Difunctionalization of alkenes to incorporate two functional groups across a double bond has emerged as a powerful transformation to greatly increase molecular complexity in organic synthesis with improved efficiency. Historically, palladium-catalyzed difunctionalization of alkenes has suffered from difficulties with introducing a second functional group through reductive elimination of a Pd(II) intermediate and competing β-hydride elimination reactions. To overcome these challenges, one strategy involves utilizing a steric bulky ligand to promote the reductive elimination steps from the Pd(II) center and impeding the β-hydride elimination reactions, which are beyond the scope of this Account...
October 14, 2016: Accounts of Chemical Research
Martin S Weiß, Ioannis V Pavlidis, Paul Spurr, Steven P Hanlon, Beat Wirz, Hans Iding, Uwe T Bornscheuer
Application of amine transaminases (ATAs) for stereoselective amination of prochiral ketones represents an environmentally benign and economically attractive alternative to transition metal catalyzed asymmetric synthesis. However, the restrictive substrate scope has limited the conversion typically to non-sterically demanding scaffolds. Recently, we reported on the identification and design of fold class I ATAs that effect a highly selective asymmetric synthesis of a set of chiral aromatic bulky amines from the corresponding ketone precursors in high yield...
October 14, 2016: Organic & Biomolecular Chemistry
Takahide Fukuyama, Yuki Fujita, Muhammad Abid Rashid, Ilhyong Ryu
A Cossy 5-exo-dig photocyclization of organohalides (X = Br, I) onto a C-C triple bond was studied using a flow photomicroreactor, which proceeded in a minute order of residence time. A deuterium labeling study supported the nonchain radical mechanism proposed by the Cossy group, in which a hydrogen source originates from a triethylamine cation radical. Scalable flow synthesis using a larger volume of flow reactor was also successful, providing 4 g of the product in high yield.
October 13, 2016: Organic Letters
Heedoo Lee, Duo Zhang, Ziwen Zhu, Charles S Dela Cruz, Yang Jin
Intercellular communications between lung epithelial cells and alveolar macrophages play an essential role in host defense against acute lung injury. Hyperoxia-induced oxidative stress is an established model to mimic human lung injury. We show that after hyperoxia-associated oxidative stress, a large amount of extracellular vesicles (EVs) are detectable in bronchoalveolar lavage fluid (BALF) and culture medium of lung epithelial cells. Microvesicles (MVs), but not exosomes (Exos) or apoptotic bodies (Abs), are the main type of EVs found in the early stages after hyperoxia...
October 12, 2016: Scientific Reports
Guo-Ming Ho, Ci-Jhang Huang, Elise Yu-Tzu Li, Sheng-Kai Hsu, Ti Wu, Medel Manuel L Zulueta, Kevin Binchia Wu, Shang-Cheng Hung
The Diels-Alder reaction is a useful tool for generating functionalized chiral molecules through the concerted cycloaddition of dienes and dienophiles leading to six-membered rings. Traditionally, the selective predictions of the products rely heavily on consideration of the secondary orbital interactions that stabilize the endo pathway. However, there remain some basic examples defying this notion and produce the exo-isomer as major product. Here we systematically evaluated of the structural features driving exo selectivity in thermal normal-electron-demand Diels-Alder reactions...
October 12, 2016: Scientific Reports
Habiba Ennouri, Paul d'Abzac, Florence Hakil, Priscilla Branchu, Murielle Naïtali, Anne-Marie Lomenech, Rhida Oueslati, Jacques Desbrières, Pierre Sivadon, Régis Grimaud
The assimilation of the nearly water insoluble substrates hydrocarbons and lipids by bacteria entails specific adaptations such as the formation of oleolytic biofilms. The present article reports that the extracellular matrix of an oleolytic biofilm formed by Marinobacter hydrocarbonoclasticus at n-hexadecane-water interfaces is largely composed of proteins typically cytoplasmic such as translation factors and chaperones, and a lesser amount of proteins of unknown function that are predicted extra-cytoplasmic...
October 11, 2016: Environmental Microbiology
Masaki Morishita, Yuki Takahashi, Akihiro Matsumoto, Makiya Nishikawa, Yoshinobu Takakura
For cancer immunotherapy via tumor antigen vaccination in combination with an adjuvant, major challenges include the identification of a particular tumor antigen and efficient delivery of the antigen as well as adjuvant to antigen-presenting cells. In this study, we proposed an efficient exosome-based tumor antigens-adjuvant co-delivery system using genetically engineered tumor cell-derived exosomes containing endogenous tumor antigens and immunostimulatory CpG DNA. Murine melanoma B16BL6 cells were transfected with a plasmid vector encoding a fusion streptavidin (SAV; a protein that binds to biotin with high affinity)-lactadherin (LA; an exosome-tropic protein) protein, yielding genetically engineered SAV-LA-expressing exosomes (SAV-exo)...
December 2016: Biomaterials
Hajime Maeda, Hiroki Takenaka, Kazuhiko Mizuno
With the aim of developing photoreactions that use intermolecular hydrogen bonding interactions to control the efficiency and stereochemistry, the 1,2-[2 + 2] photocycloaddition reactions of 1-cyanonaphthalene derivatives with vinyl ethers possessing hydroxy groups were examined. The photoreaction of 1-cyano-4-(hydroxymethyl)naphthalene (1a) with 2-hydroxyethyl vinyl ether (2a) at room temperature was found to produce cycloadducts, endo-3aa and exo-3aa, in a non-stereoselective manner (56 : 44). However, this photoreaction at -40 °C displays a high endo-selectivity (81 : 19)...
October 3, 2016: Photochemical & Photobiological Sciences
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"