Read by QxMD icon Read


Taichi Mizobuchi, Risako Nonaka, Motoki Yoshimura, Katsumasa Abe, Shouji Takahashi, Yoshio Kera, Masaru Goto
Aspartate racemase (AspR) is a pyridoxal 5'-phosphate (PLP)-dependent enzyme that is responsible for D-aspartate biosynthesis in vivo. To the best of our knowledge, this is the first study to report an X-ray crystal structure of a PLP-dependent AspR, which was resolved at 1.90 Å resolution. The AspR derived from the bivalve mollusc Scapharca broughtonii (SbAspR) is a type II PLP-dependent enzyme that is similar to serine racemase (SR) in that SbAspR catalyzes both racemization and dehydration. Structural comparison of SbAspR and SR shows a similar arrangement of the active-site residues and nucleotide-binding site, but a different orientation of the metal-binding site...
December 1, 2017: Acta Crystallographica. Section F, Structural Biology Communications
Araceli Corona, Stephanie O Palmer, Regina Zamacona, Benjamin Mendez, Frank B Dean, James M Bullard
Pseudomonas aeruginosa, an opportunistic pathogen, is highly susceptible to developing resistance to multiple antibiotics. The gene encoding aspartyl-tRNA synthetase (AspRS) from P. aeruginosa was cloned and the resulting protein characterized. AspRS was kinetically evaluated, and the KM values for aspartic acid, ATP, and tRNA were 170, 495, and 0.5 μM, respectively. AspRS was developed into a screening platform using scintillation proximity assay (SPA) technology and used to screen 1690 chemical compounds, resulting in the identification of two inhibitory compounds, BT02A02 and BT02C05...
November 1, 2017: SLAS Discovery
Stephanie Roberge, Emmanuel Bujold, Kypros H Nicolaides
OBJECTIVE DATA: Metaanalyses of randomized controlled trials have reported contradictory results about the effect of aspirin in the prevention of preeclampsia, both in terms of the gestational age at the onset of treatment and the dose of the drug. The controversy may be resolved by a metaanalysis that includes several recently published trials and particularly the large Combined Multimarker Screening and Randomized Patient Treatment with Aspirin for Evidence-based Preeclampsia Prevention trial and by examination of whether there is a difference of the effect of aspirin on preterm vs term preeclampsia...
November 11, 2017: American Journal of Obstetrics and Gynecology
David Wright, Liona C Poon, Daniel L Rolnik, Argyro Syngelaki, Juan Luis Delgado, Denisa Vojtassakova, Mercedes de Alvarado, Evgenia Kapeti, Anoop Rehal, Andrea Pazos, Ilma Floriana Carbone, Vivien Dutemeyer, Walter Plasencia, Nikos Papantoniou, Kypros H Nicolaides
BACKGROUND: The Aspirin for Evidence-Based Preeclampsia Prevention trial was a multicenter study in women with singleton pregnancies. Screening was carried out at 11-13 weeks' gestation with an algorithm that combines maternal factors and biomarkers (mean arterial pressure, uterine artery pulsatility index, and maternal serum pregnancy-associated plasma protein A and placental growth factor). Those with an estimated risk for preterm preeclampsia of >1 in 100 were invited to participate in a double-blind trial of aspirin (150 mg/d) vs placebo from 11-14 until 36 weeks' gestation...
December 2017: American Journal of Obstetrics and Gynecology
Daniel A Waxman, Edward W Chan, Francesca Pillemer, Timothy Wj Smith, Mahshid Abir, Christopher Nelson
In recent years, mass-casualty incidents (MCIs) have become more frequent and deadly, while emergency department (ED) crowding has grown steadily worse and widespread. The ability of hospitals to implement an effective mass-casualty surge plan, immediately and expertly, has therefore never been more important. Yet, mass-casualty exercises tend to be highly choreographed, pre-scheduled events that provide limited insight into hospitals' true capacity to respond to a no-notice event under real-world conditions...
August 7, 2017: Prehospital and Disaster Medicine
D L Rolnik, D Wright, L C Y Poon, A Syngelaki, N O'Gorman, C de Paco Matallana, R Akolekar, S Cicero, D Janga, M Singh, F S Molina, N Persico, J C Jani, W Plasencia, G Papaioannou, K Tenenbaum-Gavish, K H Nicolaides
OBJECTIVE: To examine the performance of screening for preterm and term pre-eclampsia (PE) in the study population participating in the ASPRE (Combined Multimarker Screening and Randomized Patient Treatment with Aspirin for Evidence-Based Preeclampsia Prevention) trial. METHODS: This was a prospective first-trimester multicenter study on screening for preterm PE in 26 941 singleton pregnancies by means of an algorithm that combines maternal factors, mean arterial pressure, uterine artery pulsatility index and maternal serum pregnancy-associated plasma protein-A and placental growth factor at 11-13 weeks' gestation...
October 2017: Ultrasound in Obstetrics & Gynecology
Enrico Grande, Antonella Zucchetto, Barbara Suligoi, Francesco Grippo, Marilena Pappagallo, Saverio Virdone, Laura Camoni, Martina Taborelli, Vincenza Regine, Diego Serraino, Luisa Frova
BACKGROUND: Multiple cause-of-death (MCOD) data allow analyzing the contribution to mortality of conditions reported on the death certificate that are not selected as the underlying cause of death. Using MCOD data, this study aimed to fully describe the cause-specific mortality of people with AIDS (PWA) compared to people without AIDS. METHODS: We conducted a nationwide investigation based on death certificates of 2,515 Italian PWA and 123,224 people without AIDS who had died between 2006 and 2010...
May 18, 2017: Population Health Metrics
Chomphunuch Songsiriritthigul, Suwimon Suebka, Chun Jung Chen, Pitchayada Fuengfuloy, Pitak Chuawong
The N-terminal anticodon-binding domain of the nondiscriminating aspartyl-tRNA synthetase (ND-AspRS) plays a crucial role in the recognition of both tRNA(Asp) and tRNA(Asn). Here, the first X-ray crystal structure of the N-terminal domain of this enzyme (ND-AspRS1-104) from the human-pathogenic bacterium Helicobacter pylori is reported at 2.0 Å resolution. The apo form of H. pylori ND-AspRS1-104 shares high structural similarity with the N-terminal anticodon-binding domains of the discriminating aspartyl-tRNA synthetase (D-AspRS) from Escherichia coli and ND-AspRS from Pseudomonas aeruginosa, allowing recognition elements to be proposed for tRNA(Asp) and tRNA(Asn)...
February 1, 2017: Acta Crystallographica. Section F, Structural Biology Communications
Kamila K Myka, Michelle Hawkins, Aisha H Syeda, Milind K Gupta, Caroline Meharg, Mark S Dillingham, Nigel J Savery, Robert G Lloyd, Peter McGlynn
Conflicts between replication and transcription challenge chromosome duplication. Escherichia coli replisome movement along transcribed DNA is promoted by Rep and UvrD accessory helicases with Δrep ΔuvrD cells being inviable under rapid growth conditions. We have discovered that mutations in a tRNA gene, aspT, in an aminoacyl tRNA synthetase, AspRS, and in a translation factor needed for efficient proline-proline bond formation, EF-P, suppress Δrep ΔuvrD lethality. Thus replication-transcription conflicts can be alleviated by the partial sacrifice of a mechanism that reduces replicative barriers, namely translating ribosomes that reduce RNA polymerase backtracking...
March 17, 2017: Nucleic Acids Research
Lizzette M Gómez Ramos, Johanna M Smeekens, Nicholas A Kovacs, Jessica C Bowman, Roger M Wartell, Ronghu Wu, Loren Dean Williams
Divergence between prokaryotic and eukaryotic ribosomal RNA (rRNA) and among eukaryotic ribosomal RNAs is focused in expansion segments (ESs). Eukaryotic ribosomes are significantly larger than prokaryotic ribosomes partly because of their ESs. We hypothesize that larger rRNAs of complex organisms could confer increased functionality to the ribosome. Here, we characterize the binding partners of Saccharomyces cerevisiae expansion segment 7 (ES7), which is the largest and most variable ES of the eukaryotic large ribosomal subunit and is located at the surface of the ribosome...
October 9, 2016: Journal of Molecular Biology
Aleyamma Mathew, Preethi Sara George, Asha Arjunan, Paul Augustine, Mc Kalavathy, G Padmakumari, Beela Sarah Mathew
BACKGROUND: Increasing breast cancer (BC) incidence rates have been reported from India; causal factors for this increased incidence are not understood and diagnosis is mostly in advanced stages. Trivandrum exhibits the highest BC incidence rates in India. This study aimed to estimate trends in incidence by age from 2005- 2014, to predict rates through 2020 and to assess the stage at diagnosis of BC in Trivandrum. MATERIALS AND METHODS: BC cases were obtained from the Population Based Cancer Registry, Trivandrum...
2016: Asian Pacific Journal of Cancer Prevention: APJCP
Neil O'Gorman, David Wright, Daniel L Rolnik, Kypros H Nicolaides, Liona C Poon
INTRODUCTION: Pre-eclampsia (PE) affects 2-3% of all pregnancies and is a major cause of maternal and perinatal morbidity and mortality. Prophylactic use of low-dose aspirin in women at risk for PE may substantially reduce the prevalence of the disease. Effective screening for PE requiring delivery before 37 weeks (preterm PE) can be provided by a combination of maternal factors, uterine artery Doppler, mean arterial pressure, maternal serum pregnancy-associated plasma protein A and placental growth factor at 11-13 weeks' gestation, with a detection rate of 75% at a false-positive rate of 10%...
June 28, 2016: BMJ Open
Nilendra Nair, Hannah Raff, Mohammed Tarek Islam, Melanie Feen, Denise M Garofalo, Kelly Sheppard
Synthesis of asparaginyl-tRNA (Asn-tRNA(Asn)) in bacteria can be formed either by directly ligating Asn to tRNA(Asn) using an asparaginyl-tRNA synthetase (AsnRS) or by synthesizing Asn on the tRNA. In the latter two-step indirect pathway, a non-discriminating aspartyl-tRNA synthetase (ND-AspRS) attaches Asp to tRNA(Asn) and the amidotransferase GatCAB transamidates the Asp to Asn on the tRNA. GatCAB can be similarly used for Gln-tRNA(Gln) formation. Most bacteria are predicted to use only one route for Asn-tRNA(Asn) formation...
February 13, 2016: Journal of Molecular Biology
Kouji Uda, Keita Abe, Yoko Dehara, Kiriko Mizobata, Natsumi Sogawa, Yuki Akagi, Mai Saigan, Atanas D Radkov, Luke A Moe
Free D-amino acids have been found in various invertebrate phyla, while amino acid racemase genes have been identified in few species. The purpose of this study is to elucidate the distribution, function, and evolution of amino acid racemases in invertebrate animals. We searched the GenBank databases, and found 11 homologous serine racemase genes from eight species in eight different invertebrate phyla. The cloned genes were identified based on their maximum activity as Acropora millepora (Cnidaria) serine racemase (SerR) and aspartate racemase (AspR), Caenorhabditis elegans (Nematoda) SerR, Capitella teleta (Annelida) SerR, Crassostrea gigas (Mollusca) SerR and AspR, Dugesia japonica (Platyhelminthes) SerR, Milnesium tardigradum (Tardigrada) SerR, Penaeus monodon (Arthropoda) SerR and AspR and Strongylocentrotus purpuratus (Echinodermata) AspR...
February 2016: Amino Acids
Cheryl Hennig, C David L Thomas, John G Clement, David M L Cooper
The primary microstructural unit of cortical bone, the secondary osteon or Haversian system, is widely assumed to have a cylindrical shape. It is generally accepted that osteons are roughly circular in cross-section and deviations from circularity have been attributed to deviations from longitudinal orientation. To our knowledge this idealized geometric relationship, which assumes osteons are perfect cylinders, has not been rigorously explored. As such, we sought to explore two research questions: (i) Does the orientation of osteons in 3D explain variation in shapes visualized in 2D? (ii) Can differences in osteon 3D orientation explain previously reported age-related differences observed in their 2D cross-sectional shape (e...
October 2015: Journal of Anatomy
Erich M Schwarz, Yan Hu, Igor Antoshechkin, Melanie M Miller, Paul W Sternberg, Raffi V Aroian
Hookworms infect over 400 million people, stunting and impoverishing them. Sequencing hookworm genomes and finding which genes they express during infection should help in devising new drugs or vaccines against hookworms. Unlike other hookworms, Ancylostoma ceylanicum infects both humans and other mammals, providing a laboratory model for hookworm disease. We determined an A. ceylanicum genome sequence of 313 Mb, with transcriptomic data throughout infection showing expression of 30,738 genes. Approximately 900 genes were upregulated during early infection in vivo, including ASPRs, a cryptic subfamily of activation-associated secreted proteins (ASPs)...
April 2015: Nature Genetics
Sara Harris Smith, Kelly J Bennett, Alicia A Livinski
BACKGROUND: Twitter has emerged as a critical source of free and openly available information during emergency response operations, providing an unmatched level of on-the-ground situational awareness in real-time. Responders and survivors turn to Twitter to share information and resources within communities, conduct rumor control, and provide a "boots on the ground" understanding of the disaster. However, the ability to tune out background "noise" is essential to effectively utilizing Twitter to identify important and useful information during an emergency response...
2014: PLoS Currents
Tateki Suzuki, Akiyoshi Nakamura, Koji Kato, Dieter Söll, Isao Tanaka, Kelly Sheppard, Min Yao
Many prokaryotes lack a tRNA synthetase to attach asparagine to its cognate tRNA(Asn), and instead synthesize asparagine from tRNA(Asn)-bound aspartate. This conversion involves two enzymes: a nondiscriminating aspartyl-tRNA synthetase (ND-AspRS) that forms Asp-tRNA(Asn), and a heterotrimeric amidotransferase GatCAB that amidates Asp-tRNA(Asn) to form Asn-tRNA(Asn) for use in protein synthesis. ND-AspRS, GatCAB, and tRNA(Asn) may assemble in an ∼400-kDa complex, known as the Asn-transamidosome, which couples the two steps of asparagine biosynthesis in space and time to yield Asn-tRNA(Asn)...
January 13, 2015: Proceedings of the National Academy of Sciences of the United States of America
Tateki Suzuki, Keitaro Yamashita, Yoshikazu Tanaka, Isao Tanaka, Min Yao
Most canonical aminoacyl-tRNAs are synthesized directly by their cognate aminoacyl-tRNA synthetases (aaRSs), but glutaminyl-tRNA(Gln) and asparaginyl-tRNA(Asn) are synthesized indirectly by two-step processes. These processes are catalyzed by the transamidosome, a large ribonucleoprotein particle composed of GatA, GatB, GatC, aaRS and tRNA. In this study, the Asn-transamidosome from Pseudomonas aeruginosa was reconstructed and crystallized by mixing purified GatCAB complex, AspRS and tRNA(Asn). The crystal of the Asn-transamidosome belonged to space group P2₁, with unit-cell parameters a=93...
June 2014: Acta Crystallographica. Section F, Structural Biology Communications
Stefani R Mladenova, Kathryn R Stein, Lianne Bartlett, Kelly Sheppard
The human pathogen Staphylococcus aureus is an asparagine prototroph despite its genome not encoding an asparagine synthetase. S. aureus does use an asparaginyl-tRNA synthetase (AsnRS) to directly ligate asparagine to tRNA(Asn). The S. aureus genome also codes for one aspartyl-tRNA synthetase (AspRS). Here we demonstrate the lone S. aureus aspartyl-tRNA synthetase has relaxed tRNA specificity and can be used with the amidotransferase GatCAB to synthesize asparagine on tRNA(Asn). S. aureus thus encodes both the direct and indirect routes for Asn-tRNA(Asn) formation while encoding only one aspartyl-tRNA synthetase...
May 2, 2014: FEBS Letters
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"