"Any girls want to chat press 911": partner selection in monitored and unmonitored teen chat rooms.

PubMed

Smahel, David; Subrahmanyam, Kaveri

2007-06-01

We examined the search for partners by participants in two teen chat services having different ecologies. Over 12,000 utterances from monitored and unmonitored chat rooms were analyzed to assess online partner selection attempts and to see how such attempts may be influenced by the presence of an adult monitor. We found that the search for partners is ubiquitous in adolescents' online haunts, just as it is in their offline lives, and approximately two requests for a partner occur each minute. Although partner selection appears to be an important activity in online teen chat rooms, there are differences in frequency and format (e.g., the use of numerals, sexualized requests) as a function of participants' age and gender, and chat room ecology (monitored vs. unmonitored).

Extending Prior Posts in Dyadic Online Text Chat

ERIC Educational Resources Information Center

Tudini, Vincenza

2015-01-01

This study explores whether chat users are able to extend prior, apparently completed posts in the dyadic online text chat context. Dyadic text chat has a unique turn-taking system, and most chat softwares do not permit users to monitor one another's written messages-in-progress. This is likely to impact on their use of online extensions as an…

Oxygen-dependent acetylation and dimerization of the corepressor CtBP2 in neural stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karaca, Esra; Lewicki, Jakub; Hermanson, Ola, E-mail: Ola.Hermanson@ki.se

2015-03-01

The transcriptional corepressor CtBP2 is essential for proper development of the nervous system. The factor exerts its repression by interacting in complexes with chromatin-modifying factors such as histone deacetylases (HDAC) 1/2 and the histone demethylase LSD1/KDM1. Notably, the histone acetyl transferase p300 acetylates CtBP2 and this is an important regulatory event of the activity and subcellular localization of the protein. We recently demonstrated an essential role for CtBPs as sensors of microenvironmental oxygen levels influencing the differentiation potential of neural stem cells (NSCs), but it is not known whether oxygen levels influence the acetylation levels of CtBP factors. Here wemore » show by using proximity ligation assay (PLA) that CtBP2 acetylation levels increased significantly in undifferentiated, proliferating NSCs under hypoxic conditions. CtBP2 interacted with the class III HDAC Sirt1 but this interaction was unaltered in hypoxic conditions, and treatment with the Sirt1 inhibitor Ex527 did not result in any significant change in total CtBP2 acetylation levels. Instead, we revealed a significant decrease in PLA signal representing CtBP2 dimerization in NSCs under hypoxic conditions, negatively correlating with the acetylation levels. Our results suggest that microenvironmental oxygen levels influence the dimerization and acetylation levels, and thereby the activity, of CtBP2 in proliferating NSCs.« less

Abiotic stress and phytohormones affect enzymic activity of 1-O-(indole-3-acetyl)-β-d-glucose: myo-inositol indoleacetyl transferase from rice (Oryza sativa).

PubMed

Ciarkowska, Anna; Ostrowski, Maciej; Jakubowska, Anna

2016-10-20

Indole-3-acetic acid (IAA) conjugation is a part of mechanism regulating free auxin concentration. 1-O-(indole-3-acetyl)-β-d-glucose: myo-inositol indoleacetyl transferase (IAInos synthase) is an enzyme involved in IAA-ester conjugates biosynthesis. Biotic and abiotic stress conditions can modulate auxin conjugates formation in plants. In this study, we investigated effect of plant hormones (IAA, ABA, SA and 2,4-D) and abiotic stress (drought and salt stress: 150mM NaCl and 300mM NaCl) on expression level and catalytic activity of rice IAInos synthase. Enzymic activity assay indicated that all tested phytohormones affected activity of IAInos synthase, but only ABA had inhibiting effect, while IAA, SA and 2,4-D activated the enzyme. Drought and salt stress induced with lower NaCl concentration resulted in decreased activity of IAInos synthase, but 300mM NaCl had no effect on the enzyme. Despite observed differences in enzymic activities, no changes of expression level, tested by semiquantitative RT-PCR and Western blot, were detected. Based on our results it has been supposed that plant hormones and stress conditions affect IAInos synthase activity on posttranslational level. Copyright © 2016 Elsevier GmbH. All rights reserved.

Sirt1 physically interacts with Tip60 and negatively regulates Tip60-mediated acetylation of H2AX

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamagata, Kazutsune, E-mail: kyamagat@ncc.go.jp; Kitabayashi, Issay

2009-12-25

Sirt1 appear to be NAD(+)-dependent deacetylase that deacetylates histones and several non-histone proteins. In this study, we identified Sirt1 as a physical interaction partner of Tip60, which is a mammalian MYST-type histone acetyl-transferase that specifically acetylates histones H2A and H4. Although Tip60 also acetylates DNA damage-specific histone H2A variant H2AX in response to DNA damage, which is a process required for appropriate DNA damage response, overexpression of Sirt1 represses Tip60-mediated acetylation of H2AX. Furthermore, Sirt1 depletion by RNAi causes excessive acetylation of H2AX, and enhances accumulation of {gamma}-ray irradiation-induced MDC1, BRCA1, and Rad51 foci in nuclei. These findings suggest thatmore » Sirt1 functions as negative regulator of Tip60-mediated acetylation of H2AX. Moreover, Sirt1 deacetylates an acetylated Tip60 in response to DNA damage and stimulates proteasome-dependent Tip60 degradation in vivo, suggesting that Sirt1 negatively regulates the protein level of Tip60 in vivo. Sirt1 may thus repress excessive activation of the DNA damage response and Rad51-homologous recombination repair by suppressing the function of Tip60.« less

Live chat alternative security protocol

NASA Astrophysics Data System (ADS)

Rahman, J. P. R.; Nugraha, E.; Febriany, A.

2018-05-01

Indonesia is one of the largest e-commerce markets in Southeast Asia, as many as 5 million people do transactions in e-commerce, therefore more and more people use live chat service to communicate with customer service. In live chat, the customer service often asks customers’ data such as, full name, address, e-mail, transaction id, which aims to verify the purchase of the product. One of the risks that will happen is sniffing which will lead to the theft of confidential information that will cause huge losses to the customer. The anticipation that will be done is build an alternative security protocol for user interaction in live chat by using a cryptographic algorithm that is useful for protecting confidential messages. Live chat requires confidentiality and data integration with encryption and hash functions. The used algorithm are Rijndael 256 bits, RSA, and SHA256. To increase the complexity, the Rijndael algorithm will be modified in the S-box and ShiftRow sections based on the shannon principle rule, the results show that all pass the Randomness test, but the modification in Shiftrow indicates a better avalanche effect. Therefore the message will be difficult to be stolen or changed.

Semiotic Processes in Chat-Based Problem-Solving Situations

ERIC Educational Resources Information Center

Schreiber, Christof

2013-01-01

This article seeks to illustrate the analysis of episodes of chat sessions based on Charles Sanders Peirce's triadic sign relation. The episodes are from a project called "Math-Chat", which is based on the use of mathematical inscriptions in an experimental setting. What is characteristic of this chat setting is that pupils are required to…

The Chat Is Coming from inside the House: An Analysis of Perceived Chat Behavior and Reality

ERIC Educational Resources Information Center

Berndt-Morris, Elizabeth; Minnis, Samantha M.

2014-01-01

When looking for ways to improve library services, we considered what data sources were readily available to us and how we could harvest and use this data. We investigated three years of chat reference statistics at Central Michigan University, a large research institution, to gain a better understanding of our patrons' chat behavior. We then…

Comparative loneliness of users versus nonusers of online chatting.

PubMed

Ong, Chorng-Shyong; Chang, Shu-Chen; Wang, Chih-Chien

2011-01-01

Online chatting is an important component of improving interpersonal relationships online, but it may reduce participants' communication time with family members. We conducted a study of the relationship between participants' intent to engage in online chatting and three dimensions of loneliness: social, familial, and romantic. This study was designed to show the effect of online chatting on each of these three dimensions of loneliness. The participants in the study were 709 students at two universities in Taiwan who were classified on the basis of whether or not they had ever engaged in online chatting. Of the participants, 651 (91.82%) fully completed the questionnaires that served as the study instruments and were included in data analysis. The study found that individuals who had participated in online chatting exhibited greater familial loneliness than those who had not because the time spent in online chatting reduced the time spent in familial relationships. Social loneliness was related to the quality of Internet relationships rather than to the time spent online. Individuals who participated in online chatting had less romantic loneliness because of a greater ease of maintaining romantic relationships online. We conclude that online chatting can reduce social loneliness through high-quality Internet relationships but may exacerbate familial loneliness.

Oxidative stress-triggered interactions between the succinyl- and acetyl-proteomes of rice leaves.

PubMed

Zhou, Heng; Finkemeier, Iris; Guan, Wenxue; Tossounian, Maria-Armineh; Wei, Bo; Young, David; Huang, Jingjing; Messens, Joris; Yang, Xibin; Zhu, Jun; Wilson, Michael H; Shen, Wenbiao; Xie, Yanjie; Foyer, Christine H

2018-05-01

Protein lysine acylations, such as succinylation and acetylation, are important post-translational modification (PTM) mechanisms, with key roles in cellular regulation. Antibody-based affinity enrichment, high-resolution liquid chromatography mass spectrometry analysis, and integrated bioinformatics analysis were used to characterize the lysine succinylome (K suc ) and acetylome (K ace ) of rice leaves. In total, 2,593 succinylated and 1,024 acetylated proteins were identified, of which 723 were simultaneously acetylated and succinylated. Proteins involved in photosynthetic carbon metabolism such as the large and small subunits of RuBisCO, ribosomal functions, and other key processes were subject to both PTMs. Preliminary insights into oxidant-induced changes to the rice acetylome and succinylome were gained from treatments with hydrogen peroxide. Exposure to oxidative stress did not regulate global changes in the rice acetylome or succinylome but rather led to modifications on a specific subset of the identified sites. De-succinylation of recombinant catalase (CATA) and glutathione S-transferase (OsGSTU6) altered the activities of these enzymes showing that this PTM may have a regulatory function. These findings not only greatly extend the list of acetylated and/or succinylated proteins but they also demonstrate the close cooperation between these PTMs in leaf proteins with key metabolic functions. © 2017 John Wiley & Sons Ltd.

Expression of spermidine/spermine N(1) -acetyl transferase (SSAT) in human prostate tissues is related to prostate cancer progression and metastasis.

PubMed

Huang, Wei; Eickhoff, Jens C; Mehraein-Ghomi, Farideh; Church, Dawn R; Wilding, George; Basu, Hirak S

2015-08-01

Prostate cancer (PCa) in many patients remains indolent for the rest of their lives, but in some patients, it progresses to lethal metastatic disease. Gleason score is the current clinical method for PCa prognosis. It cannot reliably identify aggressive PCa, when GS is ≤ 7. It is shown that oxidative stress plays a key role in PCa progression. We have shown that in cultured human PCa cells, an activation of spermidine/spermine N(1) -acetyl transferase (SSAT; EC 2.3.1.57) enzyme initiates a polyamine oxidation pathway and generates copious amounts of reactive oxygen species in polyamine-rich PCa cells. We used RNA in situ hybridization and immunohistochemistry methods to detect SSAT mRNA and protein expression in two tissue microarrays (TMA) created from patient's prostate tissues. We analyzed 423 patient's prostate tissues in the two TMAs. Our data show that there is a significant increase in both SSAT mRNA and the enzyme protein in the PCa cells as compared to their benign counterpart. This increase is even more pronounced in metastatic PCa tissues as compared to the PCa localized in the prostate. In the prostatectomy tissues from early-stage patients, the SSAT protein level is also high in the tissues obtained from the patients who ultimately progress to advanced metastatic disease. Based on these results combined with published data from our and other laboratories, we propose an activation of an autocrine feed-forward loop of PCa cell proliferation in the absence of androgen as a possible mechanism of castrate-resistant prostate cancer growth. © 2015 Wiley Periodicals, Inc.

Urinary mutagenicity and N-acetylation phenotype in textile industry workers exposed to arylamines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sinues, B.; Perez, J.; Bernal, M.L.

1992-09-15

Primary aromatic amines have been identified epidemiologically as human carcinogens. It has been suggested that the target organ affected by aromatic amines is dependent on the rate of metabolic activation. Epidemiological studies have shown an association between low acetyl transferase activity and bladder cancer risk. On this basis, our working hypothesis was that the slow acetylators could follow in a higher extent the metabolic pathway independent of N-acetylation, leading to the excretion of conjugates of electrophyles with glucuronic acid. The instability of these glucuronides could be responsible for the association between arylamine-induced bladder cancer and slow acetylator phenotype. A totalmore » of 153 individuals were included in this study: 70 exposed to arylamines (working in textile industry) and 83 nonexposed. The following parameters were determined in urine: mutagenic index in the absence of metabolic activation, S9; mutagenic index in the presence of S9; and the mutagenic index after incubation of the urine with beta-glucuronidase. All individuals were phenotyped according to their capacity of N-acetylation by using isoniazid as drug test. The results show that the mutagenic index after incubation of the urine with beta-glucuronidase is statistically higher in exposed subjects when compared with nonexposed individuals (P less than 0.001), this parameter being statistically higher among exposed subjects who were slow acetylators than among rapid metabolizers, independent of the fact that they were smokers or nonsmokers. There were no significant differences between groups for the mutagenicity in urine not incubated with beta-glucuronidase.« less

TESTING AND ANALYSES OF CHAT AND ASPHALT-CONTAINING CHAT

EPA Science Inventory

Granular mine waste are generated from the extraction and beneficiation of lead/zinc minerals. The fine gravel waste, commonly known as chat, in the Tristate Mining District contains elevated levels of lead, zinc and cadmium which can result in potentially serious human health a...

Design and rationale of the Cardiovascular Health and Text Messaging (CHAT) Study and the CHAT-Diabetes Mellitus (CHAT-DM) Study: two randomised controlled trials of text messaging to improve secondary prevention for coronary heart disease and diabetes

PubMed Central

Huo, Xiqian; Spatz, Erica S; Ding, Qinglan; Horak, Paul; Zheng, Xin; Masters, Claire; Zhang, Haibo; Irwin, Melinda L; Yan, Xiaofang; Guan, Wenchi; Li, Jing; Li, Xi; Spertus, John A; Masoudi, Frederick A; Krumholz, Harlan M; Jiang, Lixin

2017-01-01

Introduction Mobile health interventions have the potential to promote risk factor management and lifestyle modification, and are a particularly attractive approach for scaling across healthcare systems with limited resources. We are conducting two randomised trials to evaluate the efficacy of text message-based health messages in improving secondary coronary heart disease (CHD) prevention among patients with or without diabetes. Methods and analysis The Cardiovascular Health And Text Messaging (CHAT) Study and the CHAT-Diabetes Mellitus (CHAT-DM) Study are multicentre, single-blind, randomised controlled trials of text messaging versus standard treatment with 6 months of follow-up conducted in 37 hospitals throughout 17 provinces in China. The intervention group receives six text messages per week which target blood pressure control, medication adherence, physical activity, smoking cessation (when appropriate), glucose monitoring and lifestyle recommendations including diet (in CHAT-DM). The text messages were developed based on behavioural change techniques, using models such as the information-motivation-behavioural skills model, goal setting and provision of social support. A total sample size of 800 patients would be adequate for CHAT Study and sample size of 500 patients would be adequate for the CHAT-DM Study. In CHAT, the primary outcome is the change in systolic blood pressure (SBP) at 6 months. Secondary outcomes include a change in proportion of patients achieving a SBP <140 mm Hg, low-density lipoprotein cholesterol (LDL-C), physical activity, medication adherence, body mass index (BMI) and smoking cessation. In CHAT-DM, the primary outcome is the change in glycaemic haemoglobin (HbA1C) at 6 months. Secondary outcomes include a change in the proportion of patients achieving HbA1C<7%, fasting blood glucose, SBP, LDL-C, BMI, physical activity and medication adherence. Ethics and dissemination The central ethics committee at the China National Center for

Design and rationale of the Cardiovascular Health and Text Messaging (CHAT) Study and the CHAT-Diabetes Mellitus (CHAT-DM) Study: two randomised controlled trials of text messaging to improve secondary prevention for coronary heart disease and diabetes.

PubMed

Huo, Xiqian; Spatz, Erica S; Ding, Qinglan; Horak, Paul; Zheng, Xin; Masters, Claire; Zhang, Haibo; Irwin, Melinda L; Yan, Xiaofang; Guan, Wenchi; Li, Jing; Li, Xi; Spertus, John A; Masoudi, Frederick A; Krumholz, Harlan M; Jiang, Lixin

2017-12-21

Mobile health interventions have the potential to promote risk factor management and lifestyle modification, and are a particularly attractive approach for scaling across healthcare systems with limited resources. We are conducting two randomised trials to evaluate the efficacy of text message-based health messages in improving secondary coronary heart disease (CHD) prevention among patients with or without diabetes. The Cardiovascular Health And Text Messaging (CHAT) Study and the CHAT-Diabetes Mellitus (CHAT-DM) Study are multicentre, single-blind, randomised controlled trials of text messaging versus standard treatment with 6 months of follow-up conducted in 37 hospitals throughout 17 provinces in China. The intervention group receives six text messages per week which target blood pressure control, medication adherence, physical activity, smoking cessation (when appropriate), glucose monitoring and lifestyle recommendations including diet (in CHAT-DM). The text messages were developed based on behavioural change techniques, using models such as the information-motivation-behavioural skills model, goal setting and provision of social support. A total sample size of 800 patients would be adequate for CHAT Study and sample size of 500 patients would be adequate for the CHAT-DM Study. In CHAT, the primary outcome is the change in systolic blood pressure (SBP) at 6 months. Secondary outcomes include a change in proportion of patients achieving a SBP <140 mm Hg, low-density lipoprotein cholesterol (LDL-C), physical activity, medication adherence, body mass index (BMI) and smoking cessation. In CHAT-DM, the primary outcome is the change in glycaemic haemoglobin (HbA 1C ) at 6 months. Secondary outcomes include a change in the proportion of patients achieving HbA 1C <7%, fasting blood glucose, SBP, LDL-C, BMI, physical activity and medication adherence. The central ethics committee at the China National Center for Cardiovascular Disease and the Yale University

Ethanolic extract Ocimum sanctum. Enhances cognitive ability from young adulthood to middle aged mediated by increasing choline acetyl transferase activity in rat model.

PubMed

Kusindarta, Dwi Liliek; Wihadmadyatami, Hevi; Jadi, Arvendi R; Karnati, Srikanth; Lochnit, Guenter; Hening, Puspa; Haryanto, Aris; Auriva, Made B; Purwaningrum, Medania

2018-06-01

Patients with dementia are increasing steadily, cognitive impairment by dementia not only exclusively suffers by old people but also young to middle aged individuals. However, the mechanism of cognitive impairment occurs in young people is not understood. Further, current medication to impairment did not provide satisfactory results. Therefore, we investigated the potential role of Ocimum sanctum ethanolic extract to enhance cognitive ability in the rat in vivo model. Young to middle aged rats were divided into 3 groups (3, 6, 9 months old) were treated with (0, 50 and 100 mg/kg b.w.) O. sanctum for 45 days. We employed a behavioral assay to assess cognitive ability. Further, Nissl staining was performed to analyze hippocampus formation in dentate gyrus (DG), cornu ammonis 1 (CA1), cornu ammonis 3 (CA3). The expression and activity of ChAT in brain was analyzed by RT-PCR and ELISA. Our results showed that treatment of O. sanctum with a dosage of 100 mg/kg b.w. for 45 days induced the cognitive ability in nine months old rats. Further, we observed a significant increase in density of granular and pyramidal cells in DG, CA1, and CA3. These results were corroborated by an increase in the ChAT activity and gene expression in the rat model as well as HEK 293 cell culture model. Taken together, the administration of 100 mg/kg b.w. O.sanctum induced the expression of ChAT. The increased ChAT expression and activity may enhance the cognitive ability in 9 months old rats mimicking young and middle aged condition in humans. Copyright © 2018 Elsevier Ltd. All rights reserved.

Expanding Suicide Crisis Services to Text and Chat.

PubMed

Predmore, Zachary; Ramchand, Rajeev; Ayer, Lynsay; Kotzias, Virginia; Engel, Charles; Ebener, Patricia; Kemp, Janet E; Karras, Elizabeth; Haas, Gretchen L

2017-07-01

Crisis support services have historically been offered by phone-based suicide prevention hotlines, but are increasingly becoming available through alternative modalities, including Internet chat and text messaging. To better understand differences in the use of phone and chat/text services. We conducted semistructured interviews with call responders at the Veterans Crisis Line who utilize multimodal methods to respond to veterans in crisis. Responders indicated that veterans may access the chat/text service primarily for reasons that included a desire for anonymity and possible inability to use the phone. Responders were divided on whether callers and chatters presented with different issues or risk of suicide; however, they suggested that veterans frequently use chat/text to make their first contact with mental health services. We spoke with call responders, not the veterans themselves. Additionally, as this is qualitative research, applicability to other settings may be limited. While new platforms offer promise, participants also indicated that chat services can supplement phone lines, but not replace them.

The O-GlcNAc Transferase Intellectual Disability Mutation L254F Distorts the TPR Helix.

PubMed

Gundogdu, Mehmet; Llabrés, Salomé; Gorelik, Andrii; Ferenbach, Andrew T; Zachariae, Ulrich; van Aalten, Daan M F

2018-05-17

O-linked β-N-acetyl- D -glucosamine (O-GlcNAc) transferase (OGT) regulates protein O-GlcNAcylation, an essential post-translational modification that is abundant in the brain. Recently, OGT mutations have been associated with intellectual disability, although it is not understood how they affect OGT structure and function. Using a multi-disciplinary approach we show that the L254F OGT mutation leads to conformational changes of the tetratricopeptide repeats and reduced activity, revealing the molecular mechanisms contributing to pathogenesis. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Going Prime Time with Live Chat Reference.

ERIC Educational Resources Information Center

Hoag, Tara J.; Cichanowicz, Edana McCaffrey

2001-01-01

Describes the development of the Suffolk Cooperative Library System's live, online chat reference service, a pilot project for public libraries in Suffolk County (New York). Topics include chat software selection; a virtual reference collection; marketing; funding; staffing; evaluation; expanded hours of service; email; and extracting data from…

A 4'-phosphopantetheinyl transferase mediates non-ribosomal peptide synthetase activation in Aspergillus fumigatus.

PubMed

Neville, Claire; Murphy, Alan; Kavanagh, Kevin; Doyle, Sean

2005-04-01

Aspergillus fumigatus is a significant human pathogen. Non-ribosomal peptide (NRP) synthesis is thought to be responsible for a significant proportion of toxin and siderophore production in the organism. Furthermore, it has been shown that 4'-phosphopantetheinylation is required for the activation of key enzymes involved in non-ribosomal peptide synthesis in other species. Here we report the cloning, recombinant expression and functional characterisation of a 4'-phosphopantetheinyl transferase from A. fumigatus and the identification of an atypical NRP synthetase (Afpes1), spanning 14.3 kb. Phylogenetic analysis has shown that the NRP synthetase exhibits greatest identity to NRP synthetases from Metarhizium anisolpiae (PesA) and Alternaria brassicae (AbrePsy1). Northern hybridisation and RT-PCR analysis have confirmed that both genes are expressed in A. fumigatus. A 120 kDa fragment of the A. fumigatus NRP synthetase, containing a putative thiolation domain, was cloned and expressed in the baculovirus expression system. Detection of a 4'-phosphopantetheinylated peptide (SFSAMK) from this protein, by MALDI-TOF mass spectrometric analysis after coincubation of the 4'-phosphopantetheinyl transferase with the recombinant NRP synthetase fragment and acetyl CoA, confirms that it is competent to play a role in NRP synthetase activation in A. fumigatus. The 4'-phosphopantetheinyl transferase also activates, by 4'-phosphopantetheinylation, recombinant alpha-aminoadipate reductase (Lys2p) from Candida albicans, a key enzyme involved in lysine biosynthesis.

TESTING AND ANALYSES OF CHAT AND ASPHALT-CONTAINING CHAT (PRESENTATION)

EPA Science Inventory

Granular mine waste are generated from the extraction and beneficiation of lead/zinc minerals. The fine gravel waste, commonly known as chat, in the Tristate Mining District contains elevated levels of lead, zinc and cadmium which can result in potentially serious human health a...

Investigating L2 Performance in Text Chat

ERIC Educational Resources Information Center

Sauro, Shannon; Smith, Bryan

2010-01-01

This study examines the linguistic complexity and lexical diversity of both overt and covert L2 output produced during synchronous written computer-mediated communication, also referred to as chat. Video enhanced chatscripts produced by university learners of German (N = 23) engaged in dyadic task-based chat interaction were coded and analyzed for…

Will online chat help alleviate mood loneliness?

PubMed

Hu, Mu

2009-04-01

The present study examines the relationship between social Internet use and loneliness and reviews the studies about this topic from both social psychology and computer-mediated communication literature, as a response to the call for interdisciplinary research from scholars in these two areas. Two hundred thirty-four people participated in both the survey testing trait loneliness and a 5-condition (face-to-face chatting, instant message chatting, watching video, writing assignments, and "do nothing") experiment. Participants reported increase of mood loneliness after chatting online. The level of mood loneliness after online chat was higher than that in face-to-face communication. For people with high trait loneliness, the mood loneliness increase in the computer-mediated communication condition was significantly higher than in the face-to-face communication condition. The author of the current study hopes to help clarify the mixed research findings in previous social Internet use literature about this topic and reminds communication researchers of the need to explore the constructs included in "psychological well-being" in terms of their nature, mechanism, causes, consequences, and furthermore, how they are related to communication.

Internet Relay Chat.

ERIC Educational Resources Information Center

Simpson, Carol

2000-01-01

Describes Internet Relay Chats (IRCs), electronic conversations over the Internet that allow multiple users to write messages, and their applications to educational settings such as teacher collaboration and conversations between classes. Explains hardware and software requirements, IRC organization into nets and channels, and benefits and…

Identification of the S-transferase like superfamily bacillithiol transferases encoded by Bacillus subtilis

PubMed Central

Perera, Varahenage R.; Lapek, John D.; Newton, Gerald L.; Gonzalez, David J.; Pogliano, Kit

2018-01-01

Bacillithiol is a low molecular weight thiol found in Firmicutes that is analogous to glutathione, which is absent in these bacteria. Bacillithiol transferases catalyze the transfer of bacillithiol to various substrates. The S-transferase-like (STL) superfamily contains over 30,000 putative members, including bacillithiol transferases. Proteins in this family are extremely divergent and are related by structural rather than sequence similarity, leaving it unclear if all share the same biochemical activity. Bacillus subtilis encodes eight predicted STL superfamily members, only one of which has been shown to be a bacillithiol transferase. Here we find that the seven remaining proteins show varying levels of metal dependent bacillithiol transferase activity. We have renamed the eight enzymes BstA-H. Mass spectrometry and gene expression studies revealed that all of the enzymes are produced to varying levels during growth and sporulation, with BstB and BstE being the most abundant and BstF and BstH being the least abundant. Interestingly, several bacillithiol transferases are induced in the mother cell during sporulation. A strain lacking all eight bacillithiol transferases showed normal growth in the presence of stressors that adversely affect growth of bacillithiol-deficient strains, such as paraquat and CdCl2. Thus, the STL bacillithiol transferases represent a new group of proteins that play currently unknown, but potentially significant roles in bacillithiol-dependent reactions. We conclude that these enzymes are highly divergent, perhaps to cope with an equally diverse array of endogenous or exogenous toxic metabolites and oxidants. PMID:29451913

Chat reference service in medical libraries: part 2--Trends in medical school libraries.

PubMed

Dee, Cheryl R

2003-01-01

An increasing number of medical school libraries offer chat service to provide immediate, high quality information at the time and point of need to students, faculty, staff, and health care professionals. Part 2 of Chat Reference Service in Medical Libraries presents a snapshot of the current trends in chat reference service in medical school libraries. In late 2002, 25 (21%) medical school libraries provided chat reference. Trends in chat reference services in medical school libraries were compiled from an exploration of medical school library Web sites and informal correspondence from medical school library personnel. Many medical libraries are actively investigating and planning new chat reference services, while others have decided not to pursue chat reference at this time. Anecdotal comments from medical school library staff provide insights into chat reference service.

Perceived safety and teen risk taking in online chat sites.

PubMed

McCarty, Cheryl; Prawitz, Aimee D; Derscheid, Linda E; Montgomery, Bette

2011-03-01

Framed by theories of adolescent development, this study explored relationships among adolescents' perceptions of chat-site safety, time spent chatting, and risky online behaviors. Tenth graders (N = 139) in rural Midwestern U.S. schools completed surveys. Factor analysis produced three factors each for perception of safety and risk-taking behaviors. Regression analyses revealed that perception of safety factors were useful in predicting online risk-taking behaviors. Teens with more social discomfort and those who thought it was safe to reveal personal information and trust chat-site "friends" were more likely to take risks. As time spent in chat sites increased, so did risk-taking behaviors. Implications for educators and parents are discussed, such as initiation of conversations about safe Internet use, parental participation in chat sites as teens' invited "friends," and school programs to teach safe online practices.

Peer Interaction in Text Chat: Qualitative Analysis of Chat Transcripts

ERIC Educational Resources Information Center

Golonka, Ewa M.; Tare, Medha; Bonilla, Carrie

2017-01-01

Prior research has shown that intermediate-level adult learners of Russian who worked interactively with partners using text chat improved their vocabulary and oral production skills more than students who worked independently (Tare et al., 2014). Drawing on the dataset from Tare et al. (2014), the current study follows up to explore the nature of…

Mammalian Sterile 20-like Kinase 1 (Mst1) Enhances the Stability of Forkhead Box P3 (Foxp3) and the Function of Regulatory T Cells by Modulating Foxp3 Acetylation.

PubMed

Li, Jiang; Du, Xingrong; Shi, Hao; Deng, Kejing; Chi, Hongbo; Tao, Wufan

2015-12-25

Regulatory T cells (Tregs) play crucial roles in maintaining immune tolerance. The transcription factor Foxp3 is a critical regulator of Treg development and function, and its expression is regulated at both transcriptional and post-translational levels. Acetylation by lysine acetyl transferases/lysine deacetylases is one of the main post-translational modifications of Foxp3, which regulate Foxp3's stability and transcriptional activity. However, the mechanism(s) by which the activities of these lysine acetyl transferases/lysine deacetylases are regulated to preserve proper Foxp3 acetylation during Treg development and maintenance of Treg function remains to be determined. Here we report that Mst1 can enhance Foxp3 stability, its transcriptional activity, and Treg function by modulating the Foxp3 protein at the post-translational level. We discovered that Mst1 could increase the acetylation of Foxp3 by inhibiting Sirt1 activity, which requires the Mst1 kinase activity. We also found that Mst1 could attenuate Sirt1-mediated deacetylation of Foxp3 through directly interacting with Foxp3 to prevent or interfere the interaction between Sirt1 and Foxp3. Therefore, Mst1 can regulate Foxp3 stability in kinase-dependent and kinase-independent manners. Finally, we showed that treatment of Mst1(-/-) Tregs with Ex-527, a Sirt1-specific inhibitor, partially restored the suppressive function of Mst1(-/-) Tregs. Our studies reveal a novel mechanism by which Mst1 enhances Foxp3 expression and Treg function at the post-translational level. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

You Are There: No Budget for Travel? Try Video Chat

ERIC Educational Resources Information Center

Langhorst, Eric

2009-01-01

The author discusses how he used video chat as an alternative to a physical trip. Any teacher with an Internet hookup and a $30 webcam can connect with anyone in the world using video chat. Programs like Skype Video and the Google Mail's video chat function make it easy and, best of all, are completely free. The author discusses how to get started…

Brain stem hypoplasia associated with Cri-du-Chat syndrome.

PubMed

Hong, Jin Ho; Lee, Ha Young; Lim, Myung Kwan; Kim, Mi Young; Kang, Young Hye; Lee, Kyung Hee; Cho, Soon Gu

2013-01-01

Cri-du-Chat syndrome, also called the 5p-syndrome, is a rare genetic abnormality, and only few cases have been reported on its brain MRI findings. We describe the magnetic resonance imaging findings of a 1-year-old girl with Cri-du-Chat syndrome who showed brain stem hypoplasia, particularly in the pons, with normal cerebellum and diffuse hypoplasia of the cerebral hemispheres. We suggest that Cri-du-Chat syndrome chould be suspected in children with brain stem hypoplasia, particularly for those with high-pitched cries.

Harnessing the Power of Informal Learning: Using WeChat, the Semi-Synchronous Group Chat, to Enhance Spoken Fluency in Chinese Learners

ERIC Educational Resources Information Center

Sadoux, Marion

2017-01-01

This research is an exploratory study that seeks to evaluate the potentials of the Chinese app WeChat to enhance the spoken fluency of learners of French in China, who report having limited and insufficient opportunities to practice speaking in their daily life. WeChat is an extremely popular instant messenger facilitating communication through a…

Building Community Through a #pulmcc Twitter Chat to Advocate for Pulmonary, Critical Care, and Sleep.

PubMed

Carroll, Christopher L; Bruno, Kristi; Ramachandran, Pradeep

2017-08-01

Social media sites such as Twitter can significantly enhance education and advocacy efforts. In 2013, the American College of Chest Physicians (CHEST) launched a Twitter chat series using the hashtag #pulmcc to educate and advocate for topics related to pulmonary, critical care, and sleep medicine. To assess the reach of these chats, we analyzed the metrics using Symplur analytics, and compared data from each chat, as well as participant data. Since December 19, 2013, there have been 12 Twitter chats: six have been on critical care-related topics, four have been on pulmonary-/sleep-related topics, and two have been conducted during the CHEST annual meeting on more general topics. During these 1-h Twitter chats, there were a total of 4,212 tweets by 418 participants, resulting in 9,361,519 impressions (ie, views). There were similar numbers of participants and tweets in the three categories of Twitter chats, but there was a significantly greater reach during the more general Twitter chats conducted at the CHEST annual meeting, with 1,596,013 ± 126,472 impressions per chat session at these chats, compared with 739,203 ± 73,109 impressions per chat session during the critical care Twitter chats and 621,965 ± 123,933 impressions per chat session in the pulmonary/sleep chats. Seventy-five participants participated in two or more #pulmcc Twitter chats, and the average percent of return participants in each chat was 30% ± 7%. Most of the return participants were health-care providers. Twitter chats can be a powerful tool for the widespread engagement of a medical audience. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Opinions of Female Juvenile Delinquents about Their Interactions in Chat Rooms

ERIC Educational Resources Information Center

Sanger, Dixie; Long, Amie; Ritzman, Mitzi; Stofer, Keri; Davis, Candy

2004-01-01

The purpose of this study was to survey the opinions of 62 adolescent females residing in a correctional facility about their use of the Internet to participate in chat room conversations. Findings indicated that 54 of 62 girls (87.09%), with a mean age of 16.72 years, participated in chat room interactions. Most (n = 47) interacted in chat rooms…

Drug Facts Chat Day: NIH Experts Answer Students' Drug Questions

MedlinePlus

... Home Current Issue Past Issues Drug Facts Chat Day: NIH Experts Answer Students' Drug Questions Past Issues / ... Drug Abuse during their first Drug Facts Chat Day. Photo courtesy of NIDA The questions poured in… ...

GD3- and O-acetylated GD3-gangliosides in the GM2 synthase-deficient mouse brain and their immunohistochemical localization

PubMed Central

Matsuda, Junko; Vanier, Marie T.; Popa, Iuliana; Portoukalian, Jacques; Suzuki, Kunihiko

2006-01-01

Gangliosides in the brain of the knockout mouse deficient in the activity of β1,4 N-acetylgalactosaminyl transferase (β1,4 GalNAc-T)(GM2 synthase) consisted of nearly exclusively of GM3- and GD3-gangliosides as expected from the known substrate specificity of the enzyme and in confirmation of the initial reports from two laboratories that generated the mutant mouse experimentally. The total molar amount of gangliosides was approximately 30% higher in the mutant mouse brain than that in the wild-type brain. However, contrary to the initial reports, one-fourth of total GD3-ganglioside was O-acetylated. It reacted positively with an anti-O-acetylated GD3 monoclonal antibody and disappeared with a corresponding increase in GD3-ganglioside after mild alkaline treatment. The absence of O-acetylated GD3 in the initial reports can be explained by the saponification step included in their analytical procedures. Although quantitatively much less and identification tentative, we also detected GT3 and O-acetylated GT3. Anti-GD3 and anti-O-acetylated GD3 monoclonal antibodies gave positive reactions in the brain of mutant mouse as expected from the analytical results. Either antibody barely stained wild-type brain except for immunoreactivity of GD3 in the cerebellar Purkinje cells. The distributions of GD3 and O-acetylated GD3 in the brain of mutant mouse were similar but differential localization was noted in the cerebellar Purkinje cells and cerebral cortex. PMID:25792782

The Value of Chat Reference Services: A Pilot Study

ERIC Educational Resources Information Center

Jacoby, JoAnn; Ward, David; Avery, Susan; Marcyk, Emilia

2016-01-01

This article explores student, instructor, and librarian perceptions of chat reference in the context of an introductory composition course. Participants in a mixed-method study responded to an anonymized chat transcript. While student respondents valued speed and efficiency, they were willing to receive instruction and open to questions that…

Teacher Twitter Chats: Gender Differences in Participants' Contributions

ERIC Educational Resources Information Center

Kerr, Stacey L.; Schmeichel, Mardi J.

2018-01-01

Gender differences in participation were examined across four Twitter chats for social studies teachers. Analyses drawing on mixed methods revealed that while there was parity across most kinds of tweets, participants identified as men were more likely to use the examined Twitter chats to share resources, give advice, boast, promote their own…

Twitter Chats: Connect, Foster, and Engage Internal Extension Networks

ERIC Educational Resources Information Center

Seger, Jamie; Hill, Paul; Stafne, Eric; Swadley, Emy

2017-01-01

The eXtension Educational Technology Learning Network (EdTechLN) has found Twitter to be an effective form of informal communication for routinely engaging network members. Twitter chats provide Extension professionals an opportunity to reach and engage one other. As the EdTechLN's experimentation with Twitter chats has demonstrated, the use of…

Hibiscus cannabinus feruloyl-coa:monolignol transferase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilkerson, Curtis; Ralph, John; Withers, Saunia

The invention relates to isolated nucleic acids encoding a feruloyl-CoA:monolignol transferase and feruloyl-CoA:monolignol transferase enzymes. The isolated nucleic acids and/or the enzymes enable incorporation of monolignol ferulates into the lignin of plants, where such monolignol ferulates include, for example, p-coumaryl ferulate, coniferyl ferulate, and/or sinapyl ferulate. The invention also includes methods and plants that include nucleic acids encoding a feruloyl-CoA:monolignol transferase enzyme and/or feruloyl-CoA:monolignol transferase enzymes.

WeChat Addiction Suppresses the Impact of Stressful Life Events on Life Satisfaction.

PubMed

Li, Bi; Wu, Yan; Jiang, Shengyi; Zhai, Huizhen

2018-03-01

The current study examined the influences of stressful life events and WeChat addiction on life satisfaction, and investigated the mediating role of WeChat addiction on the relationship between the two research variables. A total of 463 undergraduates completed self-reported scales for stressful life events, WeChat addiction, and life satisfaction. Structural equation modeling was used to analyze the questionnaire data. The results showed the suppressing effect of WeChat addiction on the negative impact of stressful life events on life satisfaction. Stressful life events affect life satisfaction both directly and indirectly. Stressful life events are positively associated with WeChat addiction, which exerts positive impact on life satisfaction. The contributions of the findings are discussed.

Enzymatic Glycosylation by Transferases

NASA Astrophysics Data System (ADS)

Blixt, Ola; Razi, Nahid

Glycosyltransferases are important biological catalysts in cellular systems generating complex cell surface glycans involved in adhesion and signaling processes. Recent advances in glycoscience have increased the demands to access significant amount of glycans representing the glycome. Glycosyltransferases are now playing a key role for in vitro synthesis of oligosaccharides and the bacterial genome are increasingly utilized for cloning and over expression of active transferases in glycosylation reactions. This chapter highlights the recent progress towards preparative synthesis of oligosaccharides representing terminal sequences of glycoproteins and glycolipids using recombinant transferases. Transferases are also being explored in the context of solid-phase synthesis, immobilized on resins and over expression in vivo by engineered bacteria.

Optical test course teaching practice on WeChat public platform

NASA Astrophysics Data System (ADS)

Fu, Yuegang; Liu, Zhiying

2017-08-01

With the development of information technological progress, M-Learning and Micro-learning is becoming more and more popular among learners as a new micro-learning resources. Micro-curriculum is playing a more and more important role in daily learning. The students can create a new way of optical course learning through "WeChat". Under the mutual interaction of two or more parties, the use of "WeChat" can fully arouse the students' interest in learning, make the subjective initiative of students, and achieve the ultimate goal of improving the level of students. In this paper, through the analysis of the current situation of college students using the "WeChat", a new teaching model suitable for "optics" teaching is summarized, and the use of "WeChat" has been infiltrated into the teaching process, using science and technology to assist teaching. Students' interest in autonomous learning.

A Cooperative Human-Adaptive Traffic Simulation (CHATS)

NASA Technical Reports Server (NTRS)

Phillips, Charles T.; Ballin, Mark G.

1999-01-01

NASA is considering the development of a Cooperative Human-Adaptive Traffic Simulation (CHATS), to examine and evaluate performance of the National Airspace System (NAS) as the aviation community moves toward free flight. CHATS will be specifically oriented toward simulating strategic decision-making by airspace users and by the service provider s traffic management personnel, within the context of different airspace and rules assumptions. It will use human teams to represent these interests and make decisions, and will rely on computer modeling and simulation to calculate the impacts of these decisions. The simulation objectives will be to examine: 1. evolution of airspace users and the service provider s strategies, through adaptation to new operational environments; 2. air carriers competitive and cooperative behavior; 3. expected benefits to airspace users and the service provider as compared to the current NAS; 4. operational limitations of free flight concepts due to congestion and safety concerns. This paper describes an operational concept for CHATS, and presents a high-level functional design which would utilize a combination of existing and new models and simulation capabilities.

Autism Screening With Online Decision Support by Primary Care Pediatricians Aided by M-CHAT/F.

PubMed

Sturner, Raymond; Howard, Barbara; Bergmann, Paul; Morrel, Tanya; Andon, Lindsay; Marks, Danielle; Rao, Patricia; Landa, Rebecca

2016-09-01

Autism spectrum disorders (ASDs) often go undetected in toddlers. The Modified Checklist for Autism in Toddlers (M-CHAT) With Follow-up Interview (M-CHAT/F) has been shown to improve detection and reduce over-referral. However, there is little evidence supporting the administration of the interview by a primary care pediatrician (PCP) during typical checkups. The goal of this study was to evaluate the feasibility, validity, and reliability of the M-CHAT/F by PCPs with online prompts at the time of a positive M-CHAT screen. Forty-seven PCPs from 22 clinics completed 197 M-CHAT/Fs triggered by positive M-CHAT screens via the same secure Web-based platform that parents used to complete M-CHATs before an 18- or 24-month well-child visit. A second M-CHAT/F was administered live or by telephone by trained research assistants (RAs) at the Kennedy Krieger Institute Center for Autism and Related Disorders. The Autism Diagnostic Observation Schedule, Second Edition, and the Mullen Scales of Early Learning were administered as criterion measures. Measures of agreement between PCPs and RAs were calculated, and measures of test performance compared. There was 86.6% agreement between PCPs and RAs, with a Cohen's κ of 0.72. Comparison of sensitivity, specificity, positive predictive value (PPV), and overall accuracy for M-CHAT/F between PCPs and RAs showed significant equivalence for all measures. Use of the M-CHAT/F by PCPs resulted in significant improvement in PPV compared with the M-CHAT alone. Minimally trained PCPs can administer the M-CHAT/F reliably and efficiently during regular well-child visits, increasing PPV without compromising detection. Copyright © 2016 by the American Academy of Pediatrics.

PA6 Death chat: engaging with dying and death.

PubMed

Goodhead, Andrew; Hartley, Nigel

2015-04-01

Talking about death continues to be a social taboo. St Christopher's has a large, welcoming social space, (The Anniversary Centre) and is committed to opening up its buildings in a number of ways. The St Christopher's social programme, of which Death Chat is part, aims to break down social taboos. Hospices have a responsibility to engage creatively with patients, family members, carers and the wider community. Death Chat, held in the hospice buildings, enables honest discussion about dying and death and topics surrounding these themes. Death Chat meets weekly and is an open meeting that takes a different subject each week as the starting point for conversation. Cheese and wine are shared and participants quickly find a place in the group. Death Chat has attracted patients, family members, bereaved relatives and the community since September 2013. Attendees have reflected that coming has broken taboos. Peter said, 'it's nowhere near as depressing as it sounds; it's a nice, friendly atmosphere - a convivial place.' Molly found Death Chat to be a welcoming, open and challenging space, 'I have learnt that death is more about my attitude to life than anything else. It has been by far the most important lesson I have learnt since dealing with bereavement.' Death Chat provides a forum in which discussion of dying and death for recognises that these are social events and reclaims them from being taboo, to being a normal part of life's experience. © 2015, Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Talking with text: communication in therapist-led, live chat cancer support groups.

PubMed

Stephen, Joanne; Collie, Kate; McLeod, Deborah; Rojubally, Adina; Fergus, Karen; Speca, Michael; Turner, Jill; Taylor-Brown, Jill; Sellick, Scott; Burrus, Kimberly; Elramly, Mai

2014-03-01

CancerChatCanada is a pan-Canadian initiative with a mandate to make professionally led cancer support groups available to more people in Canada. Although online support groups are becoming increasingly popular, little is known about therapist-led, synchronous groups using live chat. The purpose of this study was to generate a rich descriptive account of communication experiences in CancerChatCanada groups and to gain an understanding of processes associated with previously-reported benefits. We used interpretive description to analyze interview segments from 102 patients, survivors and family caregivers who participated in CancerChatCanada groups between 2007 and 2011. The analysis yielded four inter-related process themes (Reaching Out From Home, Feeling Safe, Emotional Release, and Talking With Text) and one outcome theme (Resonance and Kinship). The findings extend previous research about text-only online support groups and provide novel insights into features of facilitated, live chat communication that are valued by group members. Copyright © 2013 Elsevier Ltd. All rights reserved.

Interplay between chromatin modulators and histone acetylation regulates the formation of accessible chromatin in the upstream regulatory region of fission yeast fbp1.

PubMed

Adachi, Akira; Senmatsu, Satoshi; Asada, Ryuta; Abe, Takuya; Hoffman, Charles S; Ohta, Kunihiro; Hirota, Kouji

2018-05-03

Numerous noncoding RNA transcripts are detected in eukaryotic cells. Noncoding RNAs transcribed across gene promoters are involved in the regulation of mRNA transcription via chromatin modulation. This function of noncoding RNA transcription was first demonstrated for the fission yeast fbp1 gene, where a cascade of noncoding RNA transcription events induces chromatin remodeling to facilitate transcription factor binding. We recently demonstrated that the noncoding RNAs from the fbp1 upstream region facilitate binding of the transcription activator Atf1 and thereby promote histone acetylation. Histone acetylation by histone acetyl transferases (HATs) and ATP-dependent chromatin remodelers (ADCRs) are implicated in chromatin remodeling, but the interplay between HATs and ADCRs in this process has not been fully elucidated. Here, we examine the roles played by two distinct ADCRs, Snf22 and Hrp3, and by the HAT Gcn5 in the transcriptional activation of fbp1. Snf22 and Hrp3 redundantly promote disassembly of chromatin in the fbp1 upstream region. Gcn5 critically contributes to nucleosome eviction in the absence of either Snf22 or Hrp3, presumably by recruiting Hrp3 in snf22∆ cells and Snf22 in hrp3∆ cells. Conversely, Gcn5-dependent histone H3 acetylation is impaired in snf22∆/hrp3∆ cells, suggesting that both redundant ADCRs induce recruitment of Gcn5 to the chromatin array in the fbp1 upstream region. These results reveal a previously unappreciated interplay between ADCRs and histone acetylation in which histone acetylation facilitates recruitment of ADCRs, while ADCRs are required for histone acetylation.

Emotion Chat: A Web Chatroom with Emotion Regulation for E-Learners

NASA Astrophysics Data System (ADS)

Zheng, Deli; Tian, Feng; Liu, Jun; Zheng, Qinghua; Qin, Jiwei

In order to compensate for lack of emotion communication between teachers and students in e-learning systems, we have designed and implemented the EmotionChat -- a web chatroom with emotion regulation. EmotionChat perceives e-learners' emotional states based on interactive text. And it recommends resources such as music, cartoons, and mottos to an e-learner when it detects negative emotional states. Meanwhile, it recommends emotion regulation cases to the e-learner's listeners and teachers. The result of our initial experiment shows that EmotionChat can recommend valuable emotion regulation policies for e-learners.

Profiling of Participants in Chat Conversations Using Creativity-Based Heuristics

ERIC Educational Resources Information Center

Chiru, Costin-Gabriel; Rebedea, Traian

2017-01-01

This article proposes a new fully automated method for identifying creativity that is manifested in a divergent task. The task is represented by chat conversations in small groups, each group having to debate on the same topics, with the purpose of better understanding the discussed concepts. The chat conversations were created by undergraduate…

Feruloyl-CoA:monolignol transferase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilkerson, Curtis; Ralph, John; Withers, Saunia

The invention relates to nucleic acids encoding a feruloyl-CoA:monolignol transferase and the feruloyl-CoA:monolignol transferase enzyme that enables incorporation of monolignol ferulates, for example, including p-coumaryl ferulate, coniferyl ferulate, and sinapyl ferulate, into the lignin of plants.

Trypanosomatidae produce acetate via a mitochondrial acetate:succinate CoA transferase

PubMed Central

Van Hellemond, Jaap J.; Opperdoes, Fred R.; Tielens, Aloysius G. M.

1998-01-01

Hydrogenosome-containing anaerobic protists, such as the trichomonads, produce large amounts of acetate by an acetate:succinate CoA transferase (ASCT)/succinyl CoA synthetase cycle. The notion that mitochondria and hydrogenosomes may have originated from the same α-proteobacterial endosymbiont has led us to look for the presence of a similar metabolic pathway in trypanosomatids because these are the earliest-branching mitochondriate eukaryotes and because they also are known to produce acetate. The mechanism of acetate production in these organisms, however, has remained unknown. Four different members of the trypanosomatid family: promastigotes of Leishmania mexicana mexicana, L. infantum and Phytomonas sp., and procyclics of Trypanosoma brucei were analyzed as well as the parasitic helminth Fasciola hepatica. They all use a mitochondrial ASCT for the production of acetate from acetyl CoA. The succinyl CoA that is produced during acetate formation by ASCT is recycled presumably to succinate by a mitochondrial succinyl CoA synthetase, concomitantly producing ATP from ADP. The ASCT of L. mexicana mexicana promastigotes was further characterized after partial purification of the enzyme. It has a high affinity for acetyl CoA (Km 0.26 mM) and a low affinity for succinate (Km 6.9 mM), which shows that significant acetate production can occur only when high mitochondrial succinate concentrations prevail. This study identifies a metabolic pathway common to mitochondria and hydrogenosomes, which strongly supports a common origin for these two organelles. PMID:9501211

`Up-regulation of histone acetylation induced by social defeat mediates the conditioned rewarding effects of cocaine.

PubMed

Montagud-Romero, S; Montesinos, J; Pascual, M; Aguilar, M A; Roger-Sanchez, C; Guerri, C; Miñarro, J; Rodríguez-Arias, M

2016-10-03

Social defeat (SD) induces a long-lasting increase in the rewarding effects of psychostimulants measured using the self-administration and conditioned place procedures (CPP). However, little is known about the epigenetic changes induced by social stress and about their role in the increased response to the rewarding effects of psychostimulants. Considering that histone acetylation regulates transcriptional activity and contributes to drug-induced behavioral changes, we addressed the hypothesis that SD induces transcriptional changes by histone modifications associated with the acquisition of place conditioning. After a fourth defeat, H3(K9) acetylation was decreased in the hippocampus, while there was an increase of HAT and a decrease of HDAC levels in the cortex. Three weeks after the last defeat, mice displayed an increase in histone H4(K12) acetylation and an upregulation of histone acetyl transferase (HAT) activity in the hippocampus. In addition, H3(K4)me3, which is closely associated with transcriptional initiation, was also augmented in the hippocampus three weeks after the last defeat. Inhibition of HAT by curcumin (100mg/kg) before each SD blocked the increase in the conditioned reinforcing effects of 1mg/kg of cocaine, while inhibition of HDAC by valproic acid (500mg/kg) before social stress potentiated cocaine-induced CPP. Preference was reinstated when animals received a priming dose of 0.5mg/kg of cocaine, an effect that was absent in untreated defeated mice. These results suggest that the experience of SD induces chromatin remodeling, alters histone acetylation and methylation, and modifies the effects of cocaine on place conditioning. They also point to epigenetic mechanisms as potential avenues leading to new treatments for the long-term effects of social stress on drug addiction. Copyright © 2016 Elsevier Inc. All rights reserved.

Protective effect of stilbenes containing extract-fraction from Cajanus cajan L. on Abeta(25-35)-induced cognitive deficits in mice.

PubMed

Ruan, Can-Jun; Si, Jian-Yong; Zhang, Li; Chen, Di-Hua; Du, Guan-Hua; Su, Lan

2009-12-25

Cajanus cajan (L.) is a traditional Chinese herb medicine which contains a lot of potential active components. In the present study, we identified the effects of the stilbenes containing extract-fraction from C. cajan L. (sECC) on Abeta(25-35)-induced cognitive deficits, oxidative stress and cholinergic dysfunction in mice. Mice were treated with sECC (100 and 200mg/kg/d) for 1-week, and then received a single intracerebroventricular (i.c.v.) injection of Abeta(25-35) (5mug/mice). Behavioral changes and neuron apoptosis in mice were evaluated using Morris water maze and TUNEL tests. Furthermore, superoxide dismutase (SOD), choline acetyl transferase (ChAT) and acetylcholine esterase (AchE) activity in hippocampus and cortex were analyzed by spectrophotometric method. The data showed that consumption of sECC (200mg/kg) significantly ameliorated the cognitive deficits and neuron apoptosis caused by i.c.v. injection of Abeta(25-35). At the same time, the decreased SOD and ChAT activity in hippocampus and cortex were markedly increased by sECC (200mg/kg). sECC has no effect on AchE activity in hippocampus and cortex. These findings suggest that sECC may be a potential candidate for the development of therapeutic agents to manage cognitive impairment associated with Alzheimer's disease (AD) through increasing the activity of ChAT and anti-oxidative mechanism.

"Live Chat" Clients at Kids Help Phone: Individual Characteristics and Problem Topics.

PubMed

Haner, Dilys; Pepler, Debra

2016-01-01

Young people in Canada prefer to use the Internet over face-to-face contact when seeking help for problems of daily living and mental health problems. Kids Help Phone (KHP) provides on-demand, anonymous help to young people via telephone and Live Chat technologies. Two hundred thirty-two phone clients and 230 Live Chat clients responded to a questionnaire at this otherwise anonymous service, providing previously inaccessible data about their individual characteristics and characterizations of the problems for which they sought help. There was a larger proportion of weighty problems (mental health and suicide) among chatters than callers. There were also more non-heterosexual youth, and those who identified as Asian and Black African or Caribbean, using Live Chat than phone. Implications for training Live Chat counsellors to respond effectively to chatters are discussed.

"Las Charlas" como expresion oral diaria ["Chats" as Daily Oral Practice].

ERIC Educational Resources Information Center

Borden, Matt

2002-01-01

An oral practice system of "chats" in the classroom functions as an extemporaneous speaking exercise or chat (without notes or prompt sheets), occurring between two students for a minute or so at the beginning of class, following which the presenters respond to other students' questions. (CNP)

"PolyCAFe"--Automatic Support for the Polyphonic Analysis of CSCL Chats

ERIC Educational Resources Information Center

Trausan-Matu, Stefan; Dascalu, Mihai; Rebedea, Traian

2014-01-01

Chat conversations and other types of online communication environments are widely used within CSCL educational scenarios. However, there is a lack of theoretical and methodological background for the analysis of collaboration. Manual assessing of non-moderated chat discussions is difficult and time-consuming, having as a consequence that learning…

An expert system for headache diagnosis: the Computerized Headache Assessment tool (CHAT).

PubMed

Maizels, Morris; Wolfe, William J

2008-01-01

Migraine is a highly prevalent chronic disorder associated with significant morbidity. Chronic daily headache syndromes, while less common, are less likely to be recognized, and impair quality of life to an even greater extent than episodic migraine. A variety of screening and diagnostic tools for migraine have been proposed and studied. Few investigators have developed and evaluated computerized programs to diagnose headache. To develop and determine the accuracy and utility of a computerized headache assessment tool (CHAT). CHAT was designed to identify all of the major primary headache disorders, distinguish daily from episodic types, and recognize medication overuse. CHAT was developed using an expert systems approach to headache diagnosis, with initial branch points determined by headache frequency and duration. Appropriate clinical criteria are presented relevant to brief and longer-lasting headaches. CHAT was posted on a web site using Microsoft active server pages and a SQL-server database server. A convenience sample of patients who presented to the adult urgent care department with headache, and patients in a family practice waiting room, were solicited to participate. Those who completed the on-line questionnaire were contacted for a diagnostic interview. One hundred thirty-five patients completed CHAT and 117 completed a diagnostic interview. CHAT correctly identified 35/35 (100%) patients with episodic migraine and 42/49 (85.7%) of patients with transformed migraine. CHAT also correctly identified 11/11 patients with chronic tension-type headache, 2/2 with episodic tension-type headache, and 1/1 with episodic cluster headache. Medication overuse was correctly recognized in 43/52 (82.7%). The most common misdiagnoses by CHAT were seen in patients with transformed migraine or new daily persistent headache. Fifty patients were referred to their primary care physician and 62 to the headache clinic. Of 29 patients referred to the PCP with a confirmed

An Assessment of Joint Chat Requirements From Current Usage Patterns

DTIC Science & Technology

2006-06-01

Army Special Forces firebases always had SATCOM connectivity with the text 35 messaging capability running and most business within the firebases was...overreact, or proactive action on bad information, and points to the need for good business rules. Some, organizations, like USCENTAF, have already...developed chat business rules. Users like how chat facilitates understanding with written text. Time and effort is saved from repeating questions

Hippocampal neurodegeneration in experimental autoimmune encephalomyelitis (EAE): potential role of inflammation activated myeloperoxidase.

PubMed

Sajad, Mir; Zargan, Jamil; Chawla, Raman; Umar, Sadiq; Sadaqat, Mir; Khan, Haider A

2009-08-01

Experimental Autoimmune Encephalomyelitis (EAE) is a well-established animal model of human multiple sclerosis (MS). The effect of this inflammatory disease on hippocampus has not been addressed. Keeping in view the above consideration an attempt was made to delineate the effect of EAE on the hippocampus of Wistar rats. The assessment of the damage to the hippocampus was done 16 days post induction by the immunolocalization of ChAT (choline acetyl transferase). ChAT decreased remarkably after induction that revealed cholinergic neuronal degeneration in the hippocampus. Subsequently, many biochemical parameters were assessed to ascertain inflammatory activation of nitric oxide and associated oxidative damage as a putative mechanism of the cholinergic degeneration. Nitric oxide metabolites increased significantly (P < 0.05) with enhancement of MPO (Myeloperoxidase activity) (P < 0.001) in the MOG (myelin oligodendrocyte protein) group as compared to the controls. Peroxidation of biomembranes increased (P < 0.001), while reduced glutathione depleted (P < 0.001) with parallel decrease in catalase (P < 0.01) and superoxide dismutase enzyme activity (P < 0.001) in the MOG group. Our results show a strong role of peroxidase dependent oxidation of nitrite and oxidative stress in cholinergic degeneration in EAE.

Resource Delivery and Teaching in Live Chat Reference: Comparing Two Libraries

ERIC Educational Resources Information Center

Dempsey, Paula R.

2017-01-01

This study investigates how reference staff at two libraries balance teaching with resource delivery in live chat reference. Analysis of 410 transcripts from one week shows that one library tends to deliver more resources from a wider range of database suggestions, to take more time in chat interactions, and to incorporate more teaching behavior…

Location based chat application for iPhone

NASA Astrophysics Data System (ADS)

Rana, Pradeep

With the increasing use of mobile devices everywhere in the world, there is a lack of social interaction between people. The objective of this thesis project is to create a location based chat application, which will help users to interact with other people around them. It will provide an opportunity to meet people when someone visits a new place. The app will use GPS coordinates of the user and will show him a list of other users based on his location. The user can then choose any of the other users from the list and start chatting with them. This app will consist of a frontend and backend. The frontend will be an iOS application and the backend will be a PHP/MYSQL server.

Learner Interaction Management in an Avatar and Chat-Based Virtual World

ERIC Educational Resources Information Center

Peterson, Mark

2006-01-01

In this paper, I report on the findings of a study that investigated non-native speaker interaction in a three dimensional (3D) virtual world that incorporates avatars and text chat known as "Active Worlds." Analysis of the chat transcripts indicated that the 24 intermediate level EFL participants were able to undertake a variety of tasks through…

Reviving a Digital Dinosaur: Text-Only Synchronous Online Chats and Peer Tutoring in Communication Centers

ERIC Educational Resources Information Center

Schwartzman, Roy

2013-01-01

A qualitative and quantitative content analysis was conducted of all text-based synchronous online chats at an oral communication peer tutoring center throughout a semester. As a comparative benchmark, chats at the same university's main library were analyzed over the same time period. The library's chats were much more heavily weighted toward…

Chat Widgets for Science Libraries

ERIC Educational Resources Information Center

Meier, John J.

2008-01-01

This paper describes chat widgets, chunks of code that can be embedded on a web site to appear as an instant messaging system, and how they can be used on a science library web site to better serve library users. Interviews were conducted concerning experiences at science and humanities libraries and more similarities than differences were…

Substrate Binding and Catalytic Mechanism of Human Choline Acetyltransferase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim,A.; Rylett, J.; Shilton, B.

2006-01-01

Choline acetyltransferase (ChAT) catalyzes the synthesis of the neurotransmitter acetylcholine from choline and acetyl-CoA, and its presence is a defining feature of cholinergic neurons. We report the structure of human ChAT to a resolution of 2.2 {angstrom} along with structures for binary complexes of ChAT with choline, CoA, and a nonhydrolyzable acetyl-CoA analogue, S-(2-oxopropyl)-CoA. The ChAT-choline complex shows which features of choline are important for binding and explains how modifications of the choline trimethylammonium group can be tolerated by the enzyme. A detailed model of the ternary Michaelis complex fully supports the direct transfer of the acetyl group from acetyl-CoAmore » to choline through a mechanism similar to that seen in the serine hydrolases for the formation of an acyl-enzyme intermediate. Domain movements accompany CoA binding, and a surface loop, which is disordered in the unliganded enzyme, becomes localized and binds directly to the phosphates of CoA, stabilizing the complex. Interactions between this surface loop and CoA may function to lower the K{sub M} for CoA and could be important for phosphorylation-dependent regulation of ChAT activity.« less

Online Chat Dependency: The Influence of Social Anxiety

NASA Astrophysics Data System (ADS)

Wang, Chih-Chien; Chang, Shu-Chen

Recent developments in information technology have made it easy for people to “chat” online with others in real time, and many do so regularly. “Virtual” relationships can be attractive, especially for people with social interaction problems in the “real world”. This study examines the influence on online chat dependency of three dimensions of social anxiety: general social situation fear, negative evaluation fear, and novel social situation fear. Participants of this study were 454 college students. The survey results show that negative evaluation fear and general social situation fear are relative to online chat dependency, while novel social situation fear does not seem to be a relevant factor.

Influence of WeChat on sleep quality among undergraduates in Chongqing, China: a cross-sectional study.

PubMed

Xu, Xianglong; Lin, Qianyi; Zhang, Yan; Zhu, Runzhi; Sharma, Manoj; Zhao, Yong

2016-01-01

Previous studies showed that social media is associated with sleep quality. WeChat (a native social media in China) is very popular in China, especially among the youth. In the second quarter of 2016, Tencent's WeChat had 806 million monthly active users. The study sought to identify the influence of WeChat on the sleep quality among undergraduate students. A cross-sectional survey adopted a multi-stage stratified sampling survey to investigate undergraduates in Chongqing, China. Data were collected on 1979 eligible adults, aged 20.27 (SD: 1.26) years old, using Pittsburgh Sleep Quality Index (PSQI) to measure sleep quality. Respondents aged 20.27 ± 1.26 years included 535 (27.0%) males, and 1311 (66.3%) reported as having poor sleep quality. Of the 1979 participants, 1320 (66.70%) were WeChat users. In multivariable analyses, gender, grade, nationality, living costs, the student leader, the only child, type of university, WeChat usage was associated with domains of PSQI among undergraduates ( p  < 0.05 for all). Compared with non-users, WeChat users had a lower score of subjective quality of sleep, sleep latency, use of sleeping medication, daytime dysfunction, and global PSQI score ( p  < 0.05 for all). WeChat users may have better sleep quality than non-WeChat users among undergraduates. To determine causal relationships, further longitudinal studies will be required to test for the association between WeChat users and sleep quality. This study may also provide some implications for health promotion on sleep quality of undergraduate students.

Mapping sugar beet pectin acetylation pattern.

PubMed

Ralet, Marie-Christine; Cabrera, Juan Carlos; Bonnin, Estelle; Quéméner, Bernard; Hellìn, Pilar; Thibault, Jean-François

2005-08-01

Homogalacturonan-derived partly methylated and/or acetylated oligogalacturonates were recovered after enzymatic hydrolysis (endo-polygalacturonase+pectin methyl esterase+side-chain degrading enzymes) of sugar beet pectin followed by anion-exchange and size exclusion chromatography. Around 90% of the GalA and 75% of the acetyl groups present in the initial sugar beet pectin were recovered as homogalacturonan-derived oligogalacturonates, the remaining GalA and acetyl belonging to rhamnogalacturonic regions. Around 50% of the acetyl groups present in sugar beet homogalacturonans were recovered as partly methylated and/or acetylated oligogalacturonates of degree of polymerisation 5 whose structures were determined by electrospray ionization ion trap mass spectrometry (ESI-IT-MSn). 2-O-acetyl- and 3-O-acetyl-GalA were detected in roughly similar amounts but 2,3-di-O-acetylation was absent. Methyl-esterified GalA residues occurred mainly upstream 2-O-acetyl GalA. Oligogalacturonates containing GalA residues that are at once methyl- and acetyl-esterified were recovered in very limited amounts. A tentative mapping of the distribution of acetyl and methyl esters within sugar beet homogalacturonans is proposed. Unsubstituted GalA residues are likely to be present in limited amounts (approximately 10% of total GalA residues), due to the fact that methyl and acetyl groups are assumed to be most often not carried by the same residues.

Genetics Home Reference: cri-du-chat syndrome

MedlinePlus

... Pinkel D. High-resolution mapping of genotype-phenotype relationships in cri du chat syndrome using array comparative ... for Links Data Files & API Site Map Subscribe Customer Support USA.gov Copyright Privacy Accessibility FOIA Viewers & ...

Using a book chat to improve attitudes and perceptions of long-term care staff about dementia.

PubMed

Larocque, Natasha; Schotsman, Chloe; Kaasalainen, Sharon; Crawshaw, Diane; McAiney, Carrie; Brazil, Emma

2014-05-01

This study sought to evaluate a book chat intervention based on Lisa Genova's novel, Still Alice, to influence long-term care (LTC) staff perceptions and attitudes when caring for individuals with dementia. A qualitative descriptive design was used. Eleven participants partook in a 2.5-hour book chat at a southern Ontario LTC facility. Following the book chat, participants answered two open-ended questions to assess how the book chat influenced their views on dementia. Thematic content analysis was used to analyze the qualitative questionnaire. Content analysis of the participants' responses revealed that the book chat positively influenced their attitudes and perceptions toward dementia, particularly by providing more insight into the individual's personal struggle with the disease. Furthermore, participants found that the book chat influenced their care practices. By creating innovative learning opportunities, attitudes and perceptions about dementia care can be transcended and greatly benefit staff, family, and residents. Copyright 2014, SLACK Incorporated.

Emotional persistence in online chatting communities

NASA Astrophysics Data System (ADS)

Garas, Antonios; Garcia, David; Skowron, Marcin; Schweitzer, Frank

2012-05-01

How do users behave in online chatrooms, where they instantaneously read and write posts? We analyzed about 2.5 million posts covering various topics in Internet relay channels, and found that user activity patterns follow known power-law and stretched exponential distributions, indicating that online chat activity is not different from other forms of communication. Analysing the emotional expressions (positive, negative, neutral) of users, we revealed a remarkable persistence both for individual users and channels. I.e. despite their anonymity, users tend to follow social norms in repeated interactions in online chats, which results in a specific emotional ``tone'' of the channels. We provide an agent-based model of emotional interaction, which recovers qualitatively both the activity patterns in chatrooms and the emotional persistence of users and channels. While our assumptions about agent's emotional expressions are rooted in psychology, the model allows to test different hypothesis regarding their emotional impact in online communication.

Emotional persistence in online chatting communities

PubMed Central

Garas, Antonios; Garcia, David; Skowron, Marcin; Schweitzer, Frank

2012-01-01

How do users behave in online chatrooms, where they instantaneously read and write posts? We analyzed about 2.5 million posts covering various topics in Internet relay channels, and found that user activity patterns follow known power-law and stretched exponential distributions, indicating that online chat activity is not different from other forms of communication. Analysing the emotional expressions (positive, negative, neutral) of users, we revealed a remarkable persistence both for individual users and channels. I.e. despite their anonymity, users tend to follow social norms in repeated interactions in online chats, which results in a specific emotional “tone” of the channels. We provide an agent-based model of emotional interaction, which recovers qualitatively both the activity patterns in chatrooms and the emotional persistence of users and channels. While our assumptions about agent's emotional expressions are rooted in psychology, the model allows to test different hypothesis regarding their emotional impact in online communication. PMID:22577512

N-acetylaspartate catabolism determines cytosolic acetyl-CoA levels and histone acetylation in brown adipocytes

PubMed Central

Prokesch, A.; Pelzmann, H. J.; Pessentheiner, A. R.; Huber, K.; Madreiter-Sokolowski, C. T.; Drougard, A.; Schittmayer, M.; Kolb, D.; Magnes, C.; Trausinger, G.; Graier, W. F.; Birner-Gruenberger, R.; Pospisilik, J. A.; Bogner-Strauss, J. G.

2016-01-01

Histone acetylation depends on the abundance of nucleo-cytoplasmic acetyl-CoA. Here, we present a novel route for cytoplasmic acetyl-CoA production in brown adipocytes. N-acetylaspartate (NAA) is a highly abundant brain metabolite catabolized by aspartoacylase yielding aspartate and acetate. The latter can be further used for acetyl-CoA production. Prior to this work, the presence of NAA has not been described in adipocytes. Here, we show that accumulation of NAA decreases the brown adipocyte phenotype. We increased intracellular NAA concentrations in brown adipocytes via media supplementation or knock-down of aspartoacylase and measured reduced lipolysis, thermogenic gene expression, and oxygen consumption. Combinations of approaches to increase intracellular NAA levels showed additive effects on lipolysis and gene repression, nearly abolishing the expression of Ucp1, Cidea, Prdm16, and Ppara. Transcriptome analyses of aspartoacylase knock-down cells indicate deficiencies in acetyl-CoA and lipid metabolism. Concordantly, cytoplasmic acetyl-CoA levels and global histone H3 acetylation were decreased. Further, activating histone marks (H3K27ac and H3K9ac) in promoters/enhancers of brown marker genes showed reduced acetylation status. Taken together, we present a novel route for cytoplasmic acetyl-CoA production in brown adipocytes. Thereby, we mechanistically connect the NAA pathway to the epigenomic regulation of gene expression, modulating the phenotype of brown adipocytes. PMID:27045997

Goethe Gossips with Grass: Using Computer Chatting Software in an Introductory Literature Course.

ERIC Educational Resources Information Center

Fraser, Catherine C.

1999-01-01

Students in a third-year introduction to German literature course chatted over networked computers, using "FirstClass" software. A brief description of the course design is provided with detailed information on how the three chat sessions were organized. (Author/VWL)

[Dental education for college students based on WeChat public platform].

PubMed

Chen, Chuan-Jun; Sun, Tan

2016-06-01

The authors proposed a model for dental education based on WeChat public platform. In this model, teachers send various kinds of digital teaching information such as PPT，word and video to the WeChat public platform and students share the information for preview before class and differentiate the key-point knowledge from those information for in-depth learning in class. Teachers also send reference materials for expansive learning after class. Questionaire through the WeChat public platform is used to evaluate teaching effect of teachers and improvement may be taken based on the feedback questionnaire. A discussion and interaction based on WeCchat between students and teacher can be aroused on a specific topic to reach a proper solution. With technique development of mobile terminal, mobile class will come true in near future.

Visualization of Expert Chat Development in a World of Warcraft Player Group

ERIC Educational Resources Information Center

Chen, Mark

2009-01-01

This article describes expertise development in a player group in the massively multiplayer online game World of Warcraft using visualization of chat log data. Charts were created to get a general sense of chat trends in a specific player group engaged in "high-end raiding", a 40-person collaborative activity. These charts helped identify patterns…

Chat-Line Interaction and Negative Feedback.

ERIC Educational Resources Information Center

Iwasaki, Junko; Oliver, Rhonda

2003-01-01

Examines communicative interactions between native speakers (NSs) and nonnative speakers (NNSs) of Japanese on Internet relay chat, with a special focus on implicit negative feedback in the interactions. Reports that NSs of Japanese gave implicit negative feedback to their NNS partners and NNSs used the feedback in their subsequent production, but…

Turbulent pressure fluctuations measured during CHATS

Treesearch

Steven P. Oncley; William J. Massman; Edward G. Patton

2008-01-01

Fast-response pressure fluctuations were included in the Canopy Horizontal Array of Turbulence Study (CHATS) at several heights within and just above the canopy in a walnut orchard. Two independent systems were intercompared and then separated. We present an evaluation of turbulence statistics - including the pressure transport term in the turbulence kinetic energy...

Video chat technology to remotely quantify dietary, supplement and medication adherence in clinical trials.

PubMed

Peterson, Courtney M; Apolzan, John W; Wright, Courtney; Martin, Corby K

2016-11-01

We conducted two studies to test the validity, reliability, feasibility and acceptability of using video chat technology to quantify dietary and pill-taking (i.e. supplement and medication) adherence. In study 1, we investigated whether video chat technology can accurately quantify adherence to dietary and pill-taking interventions. Mock study participants ate food items and swallowed pills, while performing randomised scripted 'cheating' behaviours to mimic non-adherence. Monitoring was conducted in a cross-over design, with two monitors watching in-person and two watching remotely by Skype on a smartphone. For study 2, a twenty-two-item online survey was sent to a listserv with more than 20 000 unique email addresses of past and present study participants to assess the feasibility and acceptability of the technology. For the dietary adherence tests, monitors detected 86 % of non-adherent events (sensitivity) in-person v. 78 % of events via video chat monitoring (P=0·12), with comparable inter-rater agreement (0·88 v. 0·85; P=0·62). However, for pill-taking, non-adherence trended towards being more easily detected in-person than by video chat (77 v. 60 %; P=0·08), with non-significantly higher inter-rater agreement (0·85 v. 0·69; P=0·21). Survey results from study 2 (n 1076 respondents; ≥5 % response rate) indicated that 86·4 % of study participants had video chatting hardware, 73·3 % were comfortable using the technology and 79·8 % were willing to use it for clinical research. Given the capability of video chat technology to reduce participant burden and outperform other adherence monitoring methods such as dietary self-report and pill counts, video chatting is a novel and promising platform to quantify dietary and pill-taking adherence.

Video chat technology to remotely quantify dietary, supplement, and medication adherence in clinical trials

PubMed Central

Peterson, Courtney M.; Apolzan, John W.; Wright, Courtney; Martin, Corby K.

2017-01-01

We conducted a pair of studies to test the validity, reliability, feasibility, and acceptability of using video chat technology as a novel method to quantify dietary and pill-taking (i.e., supplement and medication) adherence. In the first study, we investigated whether video chat technology can accurately quantify adherence to dietary and pill-taking interventions. Mock study participants ate food items and swallowed pills while performing randomized scripted “cheating” behaviors design to mimic non-adherence. Monitoring was conducted in a crossover design, with two monitors watching in-person and two watching remotely by Skype on a smartphone. For the second study, a 22-question online survey was sent to an email listserv with more than 20,000 unique email addresses of past and present study participants to assess the feasibility and acceptability of the technology. For the dietary adherence tests, monitors detected 86% of non-adherent events (sensitivity) in-person versus 78% of events via video chat monitoring (p=0.12), with comparable inter-rater agreement (0.88 vs. 0.85; p=0.62). However, for pill-taking, non-adherence trended towards being more easily detected in-person than by video chat (77% vs. 60%; p=0.08), with non-significantly higher inter-rater agreement (0.85 vs. 0.69; p=0.21). Survey results from the second study (N=1,076 respondents; at least a 5% response rate) indicated that 86.4% of study participants had video chatting hardware, 73.3% were comfortable using the technology; and 79.8% were willing to use it for clinical research. Given the capability of video chat technology to reduce participant burden and to outperform other adherence monitoring methods such as dietary self-report and pill counts, video chatting is a novel and highly promising platform to quantify dietary and pill-taking adherence. PMID:27753427

Technological tearoom trade: characteristics of Swedish men visiting gay Internet chat rooms.

PubMed

Tikkanen, Ronny; Ross, Michael W

2003-04-01

This study compares differences among Swedish men who never, occasionally, and frequently use Internet sexual chat rooms. The data indicate that Internet sexual chat room users are significantly different from those who never visit chat rooms. The users were younger, more likely to live at home or with a female partner, bisexual, less open about their homosexuality, less likely to be members of gay organizations, and more likely to engage in unprotected anal intercourse with casual partners. The Internet might be a mean's of approximating homosexual contact. These data suggest that the Internet may be a useful place to reach younger and bisexual men, and those who make sexual assignations, with HIV/STD preventive messages, often before they have publicly come out.

Does the Use of WeChat Lead to Subjective Well-Being?: The Effect of Use Intensity and Motivations.

PubMed

Wen, Zhengbao; Geng, Xiaowei; Ye, Yinghua

2016-10-01

Recently, WeChat has been widely used in China. The positive and negative effects of WeChat on users have received attention from researchers gradually. Using the questionnaire method, we recruited 339 undergraduates and graduates as participants, and tested the effects of WeChat on their subjective well-being (SWB) in terms of intensity. In addition, we confirmed the mediating effects of WeChat with respect to motivation. The results showed that the participants' WeChat use intensity was at a mid-level, 85.3 percent of them spending no more than 2 hours on WeChat every day. Furthermore, there have been no demographic differences in the variables of gender, place of residence, or grade. Participants' WeChat use intensity can significantly predict their use motivation and life satisfaction, and intrinsic use motivation was the mediator between the use intensity and SWB, while the other three types of motivation (external, introjection, and identification) cannot predict SWB significantly. The user's ultimate emotional experience is primarily derived from why and how they use it. We also tested whether the use motivation can be shaped.

Evaluation of the 113Online Suicide Prevention Crisis Chat Service: Outcomes, Helper Behaviors and Comparison to Telephone Hotlines.

PubMed

Mokkenstorm, Jan K; Eikelenboom, Merijn; Huisman, Annemiek; Wiebenga, Jasper; Gilissen, Renske; Kerkhof, Ad J F M; Smit, Johannes H

2017-06-01

Recognizing the importance of digital communication, major suicide prevention helplines have started offering crisis intervention by chat. To date there is little evidence supporting the effectiveness of crisis chat services. To evaluate the reach and outcomes of the 113Online volunteer-operated crisis chat service, 526 crisis chat logs were studied, replicating the use of measures that were developed to study telephone crisis calls. Reaching a relatively young population of predominantly females with severe suicidality and (mental) health problems, chat outcomes for this group were found to be comparable to those found for crisis calls to U.S. Lifeline Centers in 2003-2004, with similar but not identical associations with specific helpers' styles and attitudes. Our findings support a positive effect of the 113Online chat service, to be enhanced by practice standards addressing an apparent lack of focus on the central issue of suicidality during chats, as well as by the development of best practices specific for online crisis intervention. © 2016 The American Association of Suicidology.

Excessive use of WeChat, social interaction and locus of control among college students in China

PubMed Central

Jiang, Yingying; Ye, Zi; Wang, Ying; Yang, Lizhuang; Li, Xiaoming; Zhang, Yongjun; Pang, Liangjun; Kong, Yan; Xu, Fei; Zhang, Xiaochu

2017-01-01

In China, the number of college students using mobile phone based messaging and social networking applications like WeChat is increasing rapidly. However, there has been minimal research into the addictive nature of these applications and the psychological characteristics associate with their excessive use. There is also no published scale available for assessing excessive use of WeChat and similar applications. In the current study, we collected data from 1,245 college students in China (715 females) and developed the WeChat Excessive Use Scale (WEUS). We then assessed the relationship between excessive use of WeChat and excessive use of a social networking application-Weibo, problematic use of mobile phones, external locus of control, and social interaction skills. Our 10-item scale featured three factors, namely- “mood modification,” “salience” and ‘‘conflict”- critical factors in assessing different forms of addiction. The WEUS was found to be a reliable instrument in assessing excessive use of WeChat as it showed good internal consistency and correlated with other measures of problematic use social networking and mobile phone addiction. Our results showed that excessive users of WeChat are more likely to excessively use Weibo than they are to problematically use mobile phones. Our study also showed that greater excessive use of WeChat is associated with higher external locus of control and greater online social interaction skills. These results reveal that WeChat has unique and strong appeal among college students in China. Further, practitioners should consider dealing with malleable factors like locus of control and real life social skills in treating people with problematic messaging and social networking. PMID:28817710

Excessive use of WeChat, social interaction and locus of control among college students in China.

PubMed

Hou, Juan; Ndasauka, Yamikani; Jiang, Yingying; Ye, Zi; Wang, Ying; Yang, Lizhuang; Li, Xiaoming; Zhang, Yongjun; Pang, Liangjun; Kong, Yan; Xu, Fei; Zhang, Xiaochu

2017-01-01

In China, the number of college students using mobile phone based messaging and social networking applications like WeChat is increasing rapidly. However, there has been minimal research into the addictive nature of these applications and the psychological characteristics associate with their excessive use. There is also no published scale available for assessing excessive use of WeChat and similar applications. In the current study, we collected data from 1,245 college students in China (715 females) and developed the WeChat Excessive Use Scale (WEUS). We then assessed the relationship between excessive use of WeChat and excessive use of a social networking application-Weibo, problematic use of mobile phones, external locus of control, and social interaction skills. Our 10-item scale featured three factors, namely- "mood modification," "salience" and ''conflict"- critical factors in assessing different forms of addiction. The WEUS was found to be a reliable instrument in assessing excessive use of WeChat as it showed good internal consistency and correlated with other measures of problematic use social networking and mobile phone addiction. Our results showed that excessive users of WeChat are more likely to excessively use Weibo than they are to problematically use mobile phones. Our study also showed that greater excessive use of WeChat is associated with higher external locus of control and greater online social interaction skills. These results reveal that WeChat has unique and strong appeal among college students in China. Further, practitioners should consider dealing with malleable factors like locus of control and real life social skills in treating people with problematic messaging and social networking.

O-Acetylation of Plant Cell Wall Polysaccharides

PubMed Central

Gille, Sascha; Pauly, Markus

2011-01-01

Plant cell walls are composed of structurally diverse polymers, many of which are O-acetylated. How plants O-acetylate wall polymers and what its function is remained elusive until recently, when two protein families were identified in the model plant Arabidopsis that are involved in the O-acetylation of wall polysaccharides – the reduced wall acetylation (RWA) and the trichome birefringence-like (TBL) proteins. This review discusses the role of these two protein families in polysaccharide O-acetylation and outlines the differences and similarities of polymer acetylation mechanisms in plants, fungi, bacteria, and mammals. Members of the TBL protein family had been shown to impact pathogen resistance, freezing tolerance, and cellulose biosynthesis. The connection of TBLs to polysaccharide O-acetylation thus gives crucial leads into the biological function of wall polymer O-acetylation. From a biotechnological point understanding the O-acetylation mechanism is important as acetyl-substituents inhibit the enzymatic degradation of wall polymers and released acetate can be a potent inhibitor in microbial fermentations, thus impacting the economic viability of, e.g., lignocellulosic based biofuel production. PMID:22639638

First Things First: Internet Relay Chat Openings.

ERIC Educational Resources Information Center

Rintel, E. Sean; Mulholland, Joan; Pittam, Jeffery

2001-01-01

Argues that Internet Relay Chat (IRC) research needs to systematically address links between interaction structures, technological mediation and the instantiation and development of interpersonal relationships. Finds that openings that occur directly following user's entries into public IRC channels are often ambiguous, can disrupt relationship…

Synchronous Discussion in Online Courses: A Pedagogical Strategy for Taming the Chat Beast

ERIC Educational Resources Information Center

Smith, Craig W.

2006-01-01

Many online classes use synchronous communication--chat--as a way to conduct class discussion. However, chat can quickly disintegrate into nonproductive chaos if allowed to flow unchecked. The tools provided by course management systems such as Blackboard provide one solution to this problem by allowing instructors to grant or deny access to…

Clinical and Genetic Features of Congenital Myasthenic Syndromes due to CHAT Mutations: Case Report and Literature Review.

PubMed

Arican, Pinar; Gencpinar, Pinar; Cavusoglu, Dilek; Olgac Dundar, Nihal

2018-05-21

Congenital myasthenic syndromes (CMS) are neuromuscular transmission disorders caused by mutations in genes encoding neuromuscular junction proteins. CMS due to choline acetyltransferase (CHAT) gene is characterized by episodic apnea. We report a case of a 12-month-old female patient presented with recurrent episodic apnea carrying a mutation in CHAT gene, p.I336T. Furthermore, we describe the genetic and clinical findings in 44 CMS patients due to CHAT mutations in the literature up to date. Episodes of apnea and respiratory insufficiency are the hallmarks of CHAT mutations. Clinical manifestations usually provoked by infections and fever. CMS due to CHAT mutations are rare, but it is important to diagnosis. Early diagnosis and appropriate treatment can improve morbidity and mortality. Georg Thieme Verlag KG Stuttgart · New York.

Chat (Catha edulis): a socio economic crop in Harar Region, Eastern Ethiopia.

PubMed

Kandari, Laxman S; Yadav, Hiranmai R; Thakur, Ashok K; Kandari, Tripti

2014-01-01

Chat (Catha edulis) is an important perennial crop and its leaves are chewed for a stimulating effect. It is widely cultivated in the Ethiopian highlands of Oromia region and is figured as Ethiopia's second largest foreign exchange earner. Its cultivation accounts for about 70% of farmer's income in the study area. The common effect of its consumption leads to insomnia, a condition that the users sometimes try to overcome with sedatives or alcohol. The present study is an attempt to survey and assess the impact of crop on the community. It has been observed to implicate health problems, reduces savings and nutritional standards of the family members. The chat yields in the area ranges from 1500-1800 kg/ha through monoculture. During the study, the average monthly income of the family practicing chat cultivation was from Birr 8, 533.00 to 13, 166.00 kg/ha per year in Baate and Genede cultivating areas. When the average cost per/ha was rupees 60/kg. The present study shows that during the recent past, leaf consumption has increased significantly. Chat growers are not only producers but also traders and consumers. Its consumption has become a widespread habit from secondary schools. Highest number of consumers was found to be among drivers followed by students and shopkeepers. The consumption of the plant is not considered a taboo but on contrary a status symbol in the region. It has no legal or moral implications and is considered as a part of custom and habit of local people. High value cash crop like vegetables and orchard fruits needs to be used as a replacement for chat which could be a regular source of income to farmers. Alternative sources of income for farmers needs to be scientifically worked out and proposed keeping in view the proportion of agricultural land reserved under chat cultivation and to increase the production of food grains being produced.

Measuring Audience Engagement for Public Health Twitter Chats: Insights From #LiveFitNOLA

PubMed Central

Croston, Merriah A

2017-01-01

Background Little empirical evidence exists on the effectiveness of using Twitter as a two-way communication tool for public health practice, such as Twitter chats. Objective We analyzed whether Twitter chats facilitate engagement in two-way communications between public health entities and their audience. We also describe how to measure two-way communications, incoming and outgoing mentions, between users in a protocol using free and publicly available tools (Symplur, OpenRefine, and Gephi). Methods We used a mixed-methods approach, social network analysis, and content analysis. The study population comprised individuals and organizations participating or who were mentioned in the first #LiveFitNOLA chat, during a 75-min period on March 5, 2015, from 12:00 PM to 1:15 PM Central Time. We assessed audience engagement in two-way communications with two metrics: engagement ratio and return on engagement (ROE). Results The #LiveFitNOLA chat had 744 tweets and 66 participants with an average of 11 tweets per participant. The resulting network had 134 network members and 474 engagements. The engagement ratios and ROEs for the #LiveFitNOLA organizers were 1:1, 40% (13/32) (@TulanePRC) and 2:1, −40% (−25/63) (@FitNOLA). Content analysis showed information sharing (63.9%, 314/491) and health information (27.9%, 137/491) as the most salient theme and sub-theme, respectively. Conclusions Our findings suggest Twitter chats facilitate audience engagement in two-way communications between public health entities and their audience. The #LiveFitNOLA organizers’ engagement ratios and ROEs indicated a moderate level of engagement with their audience. The practical significance of the engagement ratio and ROE depends on the audience, context, scope, scale, and goal of a Twitter chat or other organized hashtag-based communications on Twitter. PMID:28596149

Loss of p300 and CBP disrupts histone acetylation at the mouse Sry promoter and causes XY gonadal sex reversal

PubMed Central

Carré, Gwenn-Aël; Siggers, Pam; Xipolita, Marilena; Brindle, Paul; Lutz, Beat; Wells, Sara; Greenfield, Andy

2018-01-01

Abstract CREB-binding protein (CBP, CREBBP, KAT3A) and its closely related paralogue p300 (EP300, KAT3B), together termed p300/CBP, are histone/lysine acetyl-transferases that control gene expression by modifying chromatin-associated proteins. Here, we report roles for both of these chromatin-modifying enzymes in mouse sex determination, the process by which the embryonic gonad develops into a testis or an ovary. By targeting gene ablation to embryonic gonadal somatic cells using an inducible Cre line, we show that gonads lacking either gene exhibit major abnormalities of XY gonad development at 14.5 dpc, including partial sex reversal. Embryos lacking three out of four functional copies of p300/Cbp exhibit complete XY gonadal sex reversal and have greatly reduced expression of the key testis-determining genes Sry and Sox9. An analysis of histone acetylation at the Sry promoter in mutant gonads at 11.5 dpc shows a reduction in levels of the positive histone mark H3K27Ac. Our data suggest a role for CBP/p300 in testis determination mediated by control of histone acetylation at the Sry locus and reveal a novel element in the epigenetic control of Sry and mammalian sex determination. They also suggest possible novel causes of human disorders of sex development (DSD). PMID:29145650

Association between Fatigue and Autistic Symptoms in Children with Cri du Chat Syndrome

ERIC Educational Resources Information Center

Claro, Anthony; Cornish, Kim; Gruber, Reut

2011-01-01

In the current study, the authors examined whether the fatigue level of children diagnosed with cri du chat syndrome was associated with the expression of autistic symptoms. Sixty-nine children with cri du chat syndrome were compared with 47 children with moderate to severe intellectual disabilities who did not differ on intellectual severity.…

Study on Dendrobium officinale O-acetyl-glucomannan (Dendronan®): part II. Fine structures of O-acetylated residues.

PubMed

Xing, Xiaohui; Cui, Steve W; Nie, Shaoping; Phillips, Glyn O; Goff, H Douglas; Wang, Qi

2015-03-06

Main objective of this study was to investigate the detailed structural information about O-acetylated sugar residues in Dendronan(®). A water solution (2%, w/w) of Dendronan(®) was treated with endo-β-mannanase to produce oligosaccharides rich in O-acetylated sugar residues. The oligosaccharides were partly recovered by ethanol precipitation (70%, w/w). The recovered sample (designated Hydrolyzed Dendrobium officinale Polysaccharide, HDOP) had a yield of 24.7% based on the dry weight of Dendronan(®) and was highly O-acetylated. A D2O solution of HDOP (6%, w/w) generated strong signals in (1)H, (13)C, 2D (1)H-(1)H COSY, 2D (1)H-(1)H TOCSY, 2D (1)H-(1)H NOESY, 2D (1)H-(13)C HMQC, and 2D (1)H-(13)C HMBC NMR spectra. Results of NMR analyses showed that the majority of O-acetylated mannoses were mono-substituted with acetyl groups at O-2 or O-3 position. There were small amounts of mannose residues with di-O-acetyl substitution at both O-2 and O-3 positions. Minor levels of mannoses with 6-O-acetyl, 2,6-di-O-acetyl, and 3,6-di-O-acetyl substitutions were also identified. Much information about sugar residue sequence was extracted from 2D (1)H-(13)C HMBC and 2D (1)H-(1)H NOESY spectra. (1)J(C-H) coupling constants of major sugar residues were obtained. Evidences for the existence of branches or O-acetylated glucoses in HDOP were not found. The major structure of Dendronan(®) is shown as follows: [Formula: see text] M: β-D-mannopyranose; G: β-D-glucopyranose; a: O-acetyl group. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Enzymic Synthesis of Indole-3-Acetyl-1-O-β-d-Glucose 1

PubMed Central

Leznicki, Antoni J.; Bandurski, Robert S.

1988-01-01

The first enzyme-catalyzed reaction leading from indole-3-acetic acid (IAA) to the myo-inositol esters of IAA is the synthesis of indole-3-acetyl-1-O-β-d-glucose from uridine-5′-diphosphoglucose (UDPG) and IAA. The reaction is catalyzed by the enzyme, UDPG-indol-3-ylacetyl glucosyl transferase (IAA-glucose-synthase). This work reports methods for the assay of the enzyme and for the extraction and partial purification of the enzyme from kernels of Zea mays sweet corn. The enzyme has an apparent molecular weight of 46,500 an isoelectric point of 5.5, and its pH optimum lies between 7.3 and 7.6. The enzyme is stable to storage at zero degrees but loses activity during column chromatographic procedures which can be restored only fractionally by addition of column eluates. The data suggest either multiple unknown cofactors or conformational changes leading to activity loss. Images Fig. 4 PMID:11537438

Exploring the Affordances of WeChat for Facilitating Teaching, Social and Cognitive Presence in Semi-Synchronous Language Exchange

ERIC Educational Resources Information Center

Wang, Yuping; Fang, Wei-Chieh; Han, Julia; Chen, Nian-Shing

2016-01-01

This research is an exploratory study that evaluates the affordances of WeChat for the development of a community of inquiry (CoI) in semi-synchronous language exchange supported by WeChat. WeChat is an instant messenger that facilitates a multimodal environment in which interaction can happen synchronously, semi-synchronously and asynchronously…

Adding a Feature: Can a Pop-Up Chat Box Enhance Virtual Reference Services?

PubMed

Fan, Suhua Caroline; Fought, Rick L; Gahn, Paul C

2017-01-01

Online users seek help from virtual reference services via email, phone, texting, and live chat. Technologies have enabled new features in library websites to help make this service more accessible and effective. This article is an evaluation of an experimental pop-up live chat box on the website of a health sciences library to see whether the feature would enhance virtual reference services.

Evaluating a Chat Reference Service at the University of South Alabama's Baugh Biomedical Library

ERIC Educational Resources Information Center

Clanton, Clista C.; Staggs, Geneva B.; Williams, Thomas L.

2006-01-01

The University of South Alabama's Baugh Biomedical Library recently initiated a chat reference service targeted at distance education students in the biomedical sciences. After one year of service, the library conducted an evaluation of the chat reference to assess the success of this mode of reference service. Both traditional reference and…

Sequential Dy(OTf)3 -Catalyzed Solvent-Free Per-O-Acetylation and Regioselective Anomeric De-O-Acetylation of Carbohydrates.

PubMed

Yan, Yi-Ling; Guo, Jiun-Rung; Liang, Chien-Fu

2017-09-19

Dysprosium(III) trifluoromethanesulfonate-catalyzed per-O-acetylation and regioselective anomeric de-O-acetylation of carbohydrates can be tuned by adjusting the reaction medium. In this study, the per-O-acetylation of unprotected sugars by using a near-stoichiometric amount of acetic anhydride under solvent-free conditions resulted in the exclusive formation of acetylated saccharides as anomeric mixtures, whereas anomeric de-O-acetylation in methanol resulted in a moderate-to-excellent yield. Reactions with various unprotected monosaccharides or disaccharides followed by a semi-one-pot sequential conversion into the corresponding acetylated glycosyl hemiacetal also resulted in high yields. Furthermore, the obtained hemiacetals could be successfully transformed into trichloroimidates after Dy(OTf) 3 -catalyzed glycosylation. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Online Chats to Assess Stakeholder Perceptions of Meat Chicken Intensification and Welfare

PubMed Central

Howell, Tiffani J.; Rohlf, Vanessa I.; Coleman, Grahame J.; Rault, Jean-Loup

2016-01-01

Simple Summary Most people care about animal welfare. Nevertheless, divergent views remain on what constitutes animal welfare, despite a growing body of scientific evidence. We used online chats to trigger discussion among participants from various stakeholder groups: general public, animal advocacy group, meat chicken industry-affiliated, and researchers or veterinarians who were not industry-affiliated but had experience with chickens. The aim of this pilot study was to assess reasons for divergence in opinions or conversely agreement between participants, using the topic of the welfare implications of meat chicken farming intensification. Participants also completed a pre- and post-chat survey to evaluate their perceptions and knowledge of chicken farming. Reasons for supporting intensification included perceptions of better health for the chickens and the sustainability of the system. Reasons for opposition included perceptions of the large number of animals kept together, and limited ability to perform natural behaviours. Misunderstandings about current practices were clarified in chats which contained industry-affiliated participants. Participants agreed on the need for enforceable standards and industry transparency. On average, objective knowledge of intensification increased after participating in the chat, but support for intensification did not change over the course of the study, counter to assertions that lack of knowledge results in lack of support for some practices. Engaging stakeholders can provide valuable information to anyone interested in the relationship between perception and knowledge of specific farming practices. Abstract Evidence suggests that there is variation in support for specific chicken farming practices amongst stakeholder groups, and this should be explored in more detail to understand the nature of these differences and work towards convergence. Online focus groups were used to assess attitudes to animal welfare in meat chicken

The usability of WeChat as a mobile and interactive medium in student-centered medical teaching.

PubMed

Wang, Juan; Gao, Furong; Li, Jiao; Zhang, Jieping; Li, Siguang; Xu, Guo-Tong; Xu, Lei; Chen, Jianjun; Lu, Lixia

2017-09-01

Biochemistry and cellular biology courses for medical students at Tongji University include the assessment that provides students with feedback to enhance their learning, which is a type of formative assessment. However, frequent instant feedback and guidance for students is often absent or inconsistently included in the teaching process. WeChat, the most popular Chinese social media, was introduced in biochemistry and cellular biology course. A WeChat official account (OA) was set up as an instant interactive platform. Over a period of two semesters, OA sent 73 push notifications. The components included course notices, preclass thought questions, after-class study materials, answer questions and feedback, simulation exercises, teacher-student interaction, and research progress relevant to the course. WeChat OA served as an active-learning teaching tool, provided more frequent feedback and guidance to students, and facilitated better student-centered communication in the teaching process. Using the WeChat OA in medical teaching emphasized interactive, interoperable, effective, engaging, adaptable, and more participatory teaching styles. As a new platform, WeChat OA was free, Internet-reliant, and easily managed. Using this new medium as a communication tool accelerated further advancement of instant feedback and improvement in teaching activities. Notifications and interactive feedback via the mobile social medium WeChat OA anytime and anywhere facilitated a student-centered teaching mode. Use of WeChat OA significantly increased the proportion of students interactively participating and resulted in a high degree of student satisfaction. © 2017 by The International Union of Biochemistry and Molecular Biology, 45(5):421-425, 2017. © 2017 The International Union of Biochemistry and Molecular Biology.

Evidence of Strict Stereospecificity in the Structure of sn-1,2-Diacyl-3-Acetyl-Glycerols from Euonymus maximowiczianus Seeds Using Nuclear Magnetic Resonance Spectroscopy.

PubMed

Sidorov, Roman A; Shashkov, Alexander S; Solovyev, Pavel A; Gorshkova, Elena N; Tsydendambaev, Vladimir D

2018-05-02

Asymmetric, optically active sn-1,2-diacyl-3-acetyl-glycerols (AcDAG) have been known to scientists for several decades. However, to date, the problem of their structure has not been definitely resolved, which has led to a vast diversity of terms used for their designation in the literature. Using two-dimensional nuclear magnetic resonance, we have investigated AcDAG from the mature seeds of Euonymus maximowiczianus, from which we have been able to both identify a correlation of the methyl group in acetic acid residue with protons at the carbon atom at sn-3 position in the glycerol residue of the AcDAG molecule and, for the first time, demonstrate that this correlation is observed exclusively with one carbon atom at the α-position, but not with two as would have been expected in case of a racemic mixture. Moreover, results of our analysis of AcDAG isolated from the seeds of E. maximowiczianus directly confirm that diacylglycerol-3-acetyl-transferase is responsible for their biosynthesis, which reveals a strict specificity not only to acetyl-CoA as one of the substrates but also to the sn-3-position of the glycerol residue in sn-1,2-diacylglycerol during their biosynthesis. © 2018 AOCS.

A Method to Determine Lysine Acetylation Stoichiometries

DOE PAGES

Nakayasu, Ernesto S.; Wu, Si; Sydor, Michael A.; ...

2014-01-01

Lysine acetylation is a common protein posttranslational modification that regulates a variety of biological processes. A major bottleneck to fully understanding the functional aspects of lysine acetylation is the difficulty in measuring the proportion of lysine residues that are acetylated. Here we describe a mass spectrometry method using a combination of isotope labeling and detection of a diagnostic fragment ion to determine the stoichiometry of protein lysine acetylation. Using this technique, we determined the modification occupancy for ~750 acetylated peptides from mammalian cell lysates. Furthermore, the acetylation on N-terminal tail of histone H4 was cross-validated by treating cells with sodiummore » butyrate, a potent deacetylase inhibitor, and comparing changes in stoichiometry levels measured by our method with immunoblotting measurements. Of note we observe that acetylation stoichiometry is high in nuclear proteins, but very low in mitochondrial and cytosolic proteins. In summary, our method opens new opportunities to study in detail the relationship of lysine acetylation levels of proteins with their biological functions.« less

[Influence of WeChat platform on the compliance of continuous treatment of scar in adult burn patients].

PubMed

Wang, F; Zhang, H L

2018-03-20

Objective: To explore influence of the WeChat platform on the compliance of continuous treatment of scar in adult burn patients. Methods: A total of 124 adult burn patients, conforming to the study criteria, admitted in the Department of Burns of our hospital from January 2015 to January 2016 were divided into WeChat group ( n =63) and control group ( n =61) according to the random number table. Patients in control group only received regular discharging rehabilitation guide, while patients in WeChat group received regular discharging rehabilitation guide and joined WeChat platform after being discharged from hospital. Through pushing rehabilitation plan and rehabilitation related knowledge, organizing support discussion of burn patients, answering the patients' questions, members of WeChat platform intervention group conducted continuous treatment for 6 months on patients of WeChat group. The compliance of functional exercise of patients in two groups in one week before discharge and 3 and 6 months after discharge was evaluated by using the self-made functional exercise compliance log sheet. The compliance of using anti-scar drug and appliance of patients in two groups in 3 and 6 months after discharge was evaluated by using self-made anti-scar drug and appliance usage log sheets. Data were processed with chi-square test, independent sample t test, non-parametric rank sum test of independent sample, and Wilcoxon rank sum test. Results: (1) The compliance ratio of functional exercise of patients in WeChat group (95.24%, 60/63) was close to 93.44% (57/61) in control group in one week before discharge ( χ (2)=0.188, P >0.05). The compliance ratios of functional exercise of patients in WeChat group were respectively 93.65% (59/63) and 87.30% (55/63) in 3 and 6 months after discharge, which were higher than 68.85% (42/61) and 65.57% (40/61) in control group ( χ (2)=12.615, 8.166, P <0.01). (2) The compliance of using anti-scar drug of patients in WeChat group was

Measuring Audience Engagement for Public Health Twitter Chats: Insights From #LiveFitNOLA.

PubMed

Rabarison, Kristina M; Croston, Merriah A; Englar, Naomi K; Bish, Connie L; Flynn, Shelbi M; Johnson, Carolyn C

2017-06-08

Little empirical evidence exists on the effectiveness of using Twitter as a two-way communication tool for public health practice, such as Twitter chats. We analyzed whether Twitter chats facilitate engagement in two-way communications between public health entities and their audience. We also describe how to measure two-way communications, incoming and outgoing mentions, between users in a protocol using free and publicly available tools (Symplur, OpenRefine, and Gephi). We used a mixed-methods approach, social network analysis, and content analysis. The study population comprised individuals and organizations participating or who were mentioned in the first #LiveFitNOLA chat, during a 75-min period on March 5, 2015, from 12:00 PM to 1:15 PM Central Time. We assessed audience engagement in two-way communications with two metrics: engagement ratio and return on engagement (ROE). The #LiveFitNOLA chat had 744 tweets and 66 participants with an average of 11 tweets per participant. The resulting network had 134 network members and 474 engagements. The engagement ratios and ROEs for the #LiveFitNOLA organizers were 1:1, 40% (13/32) (@TulanePRC) and 2:1, -40% (-25/63) (@FitNOLA). Content analysis showed information sharing (63.9%, 314/491) and health information (27.9%, 137/491) as the most salient theme and sub-theme, respectively. Our findings suggest Twitter chats facilitate audience engagement in two-way communications between public health entities and their audience. The #LiveFitNOLA organizers' engagement ratios and ROEs indicated a moderate level of engagement with their audience. The practical significance of the engagement ratio and ROE depends on the audience, context, scope, scale, and goal of a Twitter chat or other organized hashtag-based communications on Twitter. ©Kristina M Rabarison, Merriah A Croston, Naomi K Englar, Connie L Bish, Shelbi M Flynn, Carolyn C Johnson. Originally published in JMIR Public Health and Surveillance (http

Evaluating the Quality of a Chat Service

ERIC Educational Resources Information Center

Arnold, Julie; Kaske, Neal K.

2005-01-01

A quantitative study of a university chat reference service (online synchronous) addresses the following research questions: (1) What types of questions are being asked? (2) Who is asking the questions of the service? and (3) Did the customers get correct answers to their questions? All the transcripts (351) from January through August 2002 were…

Codominant Expression of N-Acetylation and O-Acetylation Activities Catalyzed by N-Acetyltransferase 2 in Human Hepatocytes

PubMed Central

Doll, Mark A.; Zang, Yu; Moeller, Timothy

2010-01-01

Human populations exhibit genetic polymorphism in N-acetylation capacity, catalyzed by N-acetyltransferase 2 (NAT2). We investigated the relationship between NAT2 acetylator genotype and phenotype in cryopreserved human hepatocytes. NAT2 genotypes determined in 256 human samples were assigned as rapid (two rapid alleles), intermediate (one rapid and one slow allele), or slow (two slow alleles) acetylator phenotypes based on functional characterization of the NAT2 alleles reported previously in recombinant expression systems. A robust and significant relationship was observed between deduced NAT2 phenotype (rapid, intermediate, or slow) and N-acetyltransferase activity toward sulfamethazine (p < 0.0001) and 4-aminobiphenyl (p < 0.0001) and for O-acetyltransferase-catalyzed metabolic activation of N-hydroxy-4-aminobiphenyl (p < 0.0001), N-hydroxy-2-amino-3,8-dimethylimidazo[4,5-f] quinoxaline (p < 0.01), and N-hydroxy-2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine (p < 0.0001). NAT2-specific protein levels also significantly associated with the rapid, intermediate, and slow NAT2 acetylator phenotypes (p < 0.0001). As a negative control, p-aminobenzoic acid (an N-acetyltransferase 1-selective substrate) N-acetyltransferase activities from the same samples did not correlate with the three NAT2 acetylator phenotypes (p > 0.05). These results clearly document codominant expression of human NAT2 alleles resulting in rapid, intermediate, and slow acetylator phenotypes. The three phenotypes reflect levels of NAT2 protein catalyzing both N- and O-acetylation. Our results suggest a significant role of NAT2 acetylation polymorphism in arylamine-induced cancers and are consistent with differential cancer risk and/or drug efficacy/toxicity in intermediate compared with rapid or slow NAT2 acetylator phenotypes. PMID:20430842

Contractile actin cables induced by Bacillus anthracis lethal toxin depend on the histone acetylation machinery.

PubMed

Rolando, Monica; Stefani, Caroline; Doye, Anne; Acosta, Maria I; Visvikis, Orane; Yevick, Hannah G; Buchrieser, Carmen; Mettouchi, Amel; Bassereau, Patricia; Lemichez, Emmanuel

2015-10-01

It remains a challenge to decode the molecular basis of the long-term actin cytoskeleton rearrangements that are governed by the reprogramming of gene expression. Bacillus anthracis lethal toxin (LT) inhibits mitogen-activated protein kinase (MAPK) signaling, thereby modulating gene expression, with major consequences for actin cytoskeleton organization and the loss of endothelial barrier function. Using a laser ablation approach, we characterized the contractile and tensile mechanical properties of LT-induced stress fibers. These actin cables resist pulling forces that are transmitted at cell-matrix interfaces and at cell-cell discontinuous adherens junctions. We report that treating the cells with trichostatin A (TSA), a broad range inhibitor of histone deacetylases (HDACs), or with MS-275, which targets HDAC1, 2 and 3, induces stress fibers. LT decreased the cellular levels of HDAC1, 2 and 3 and reduced the global HDAC activity in the nucleus. Both the LT and TSA treatments induced Rnd3 expression, which is required for the LT-mediated induction of actin stress fibers. Furthermore, we reveal that treating the LT-intoxicated cells with garcinol, an inhibitor of histone acetyl-transferases (HATs), disrupts the stress fibers and limits the monolayer barrier dysfunctions. These data demonstrate the importance of modulating the flux of protein acetylation in order to control actin cytoskeleton organization and the endothelial cell monolayer barrier. © 2015 Wiley Periodicals, Inc.

Look at That! Video Chat and Joint Visual Attention Development among Babies and Toddlers

ERIC Educational Resources Information Center

McClure, Elisabeth R.; Chentsova-Dutton, Yulia E.; Holochwost, Steven J.; Parrott, W. G.; Barr, Rachel

2018-01-01

Although many relatives use video chat to keep in touch with toddlers, key features of adult-toddler interaction like joint visual attention (JVA) may be compromised in this context. In this study, 25 families with a child between 6 and 24 months were observed using video chat at home with geographically separated grandparents. We define two types…

Effects of AF64A on gene expression of choline acetyltransferase (ChAT) in the septo-hippocampal pathway and striatum in vivo.

PubMed

Fan, Q I; Hanin, I

1999-01-01

AF64A (ethylcholine mustard aziridinium ion) was stereotaxically administered bilaterally (1 nmol/side) into rat lateral cerebral ventricles. Choline acetyltransferase (ChAT) activity and ChAT mRNA levels were measured at predetermined time points in the septo-hippocampal pathway and striatum, both well identified as rich in cholinergic neurons. AF64A caused a rapid but transient increase in ChAT mRNA (167%, P < 0.05) and ChAT activity (164%, P < 0.01) in the septum. By day 7 post treatment, there was a significant decrease in ChAT mRNA (42.5% of control, P < 0.05) in the septum although the ChAT activity still stayed high. This decreased ChAT mRNA level in the septum lasted for at least four weeks, and was paralleled by a long-lasting decrease in ChAT activity in the hippocampus. In the striatum, on the other hand, there were no observed changes in either ChAT activity or ChAT mRNA. These data suggest that the long term effect of AF64A on the septo-hippocampal cholinergic pathway may, at least in part, be due to an action of AF64A on gene expression in the cholinergic neuron. The difference in the response to AF64A between the septo-hippocampal and striatal cholinergic systems might be due to their difference in neuron types.

Immunity status of adults and children against poliomyelitis virus type 1 strains CHAT and Sabin (LSc-2ab) in Germany.

PubMed

Eggers, Maren; Terletskaia-Ladwig, Elena; Rabenau, Holger F; Doerr, Hans W; Diedrich, Sabine; Enders, Gisela; Enders, Martin

2010-12-09

In October 2007, the working group CEN/TC 216 of the European Committee for standardisation suggested that the Sabin oral poliovirus vaccine type 1 strain (LSc-2ab) presently used for virucidal tests should be replaced by another attenuated vaccine poliovirus type 1 strain, CHAT. Both strains were historically used as oral vaccines, but the Sabin type 1 strain was acknowledged to be more attenuated. In Germany, vaccination against poliomyelitis was introduced in 1962 using the oral polio vaccine (OPV) containing Sabin strain LSc-2ab. The vaccination schedule was changed from OPV to an inactivated polio vaccine (IPV) containing wild polio virus type 1 strain Mahoney in 1998. In the present study, we assessed potential differences in neutralising antibody titres to Sabin and CHAT in persons with a history of either OPV, IPV, or OPV with IPV booster. Neutralisation poliovirus antibodies against CHAT and Sabin 1 were measured in sera of 41 adults vaccinated with OPV. Additionally, sera from 28 children less than 10 years of age and immunised with IPV only were analysed. The neutralisation assay against poliovirus was performed according to WHO guidelines. The neutralisation activity against CHAT in adults with OPV vaccination history was significantly lower than against Sabin poliovirus type 1 strains (Wilcoxon signed-rank test P < 0.025). In eight sera, the antibody titres measured against CHAT were less than 8, although the titre against Sabin 1 varied between 8 and 64. Following IPV booster, anti-CHAT antibodies increased rapidly in sera of CHAT-negative adults with OPV history. Sera from children with IPV history neutralised CHAT and Sabin 1 strains equally. The lack of neutralising antibodies against the CHAT strain in persons vaccinated with OPV might be associated with an increased risk of reinfection with the CHAT polio virus type 1, and this implies a putative risk of transmission of the virus to polio-free communities. We strongly suggest that laboratory

Assessment of orofacial characteristics and oral pathology associated with cri-du-chat syndrome.

PubMed

Rodríguez-Caballero, A; Torres-Lagares, D; Yáñez-Vico, R-M; Gutiérrez-Pérez, J-L; Machuca-Portillo, G

2012-03-01

To obtain a deeper insight into the difficulties individuals with cri-du-chat syndrome experience by means of the analysis of the most common features and oral pathology observed in the subjects enrolled in the study. Intra-oral and extra-oral features of a total of 33 patients with cri-du-chat syndrome (the larger sample so far analyzed) through their clinical and photographic examination. Models, orthopantomographies, and teleradiographies have been collected to establish a pattern as accurate as possible of the oral pathology associated with these patients. The present descriptive study shows that patients with cri-du-chat syndrome present with a series of orofacial features such as mandibular retrognathism, high palate, and variable malocclusion, more commonly anterior open-bite. Most patients also present with perioral muscle relaxation with labial incompetence and short philtrum. As regards oral pathology, these patients suffer dental erosions provoked by gastroesophageal reflux and attritions because of intense day-and-night bruxism. The odontologists' familiarity with the orofacial pathology associated with cri-du-chat syndrome and with the specific needs such disorder conveys should improve the quality of the buccodental treatment these professionals may offer to these patients. © 2011 John Wiley & Sons A/S.

Development of Communication Conventions in Instructional Electronic Chats.

ERIC Educational Resources Information Center

Collins, Mauri P.; Murphy, Karen L.

1997-01-01

This study used content analysis to identify the communication conventions and protocols that real-time, interactive electronic chat users developed in instructional settings. Most frequently used conventions included sharing information/techniques for conveying meaning and indicating interest in a topic, using keywords and names of individuals,…

Acetyl transfer in arylamine metabolism

PubMed Central

Booth, J.

1966-01-01

1. N-Hydroxyacetamidoaryl compounds (hydroxamic acids) are metabolites of arylamides, and an enzyme that transfers the acetyl group from these derivatives to arylamines has been found in rat tissues. The reaction products were identified by thin-layer chromatography and a spectrophotometric method, with 4-amino-azobenzene as acetyl acceptor, was used to measure enzyme activity. 2. The acetyltransferase was in the soluble fraction of rat liver, required a thiol for maximum activity and had a pH optimum between 6·0 and 7·5. 3. The soluble fractions of various rat tissues showed decreasing activity in the following order: liver, adrenal, kidney, lung, spleen, testis, heart; brain was inactive. 4. With the exception of aniline and aniline derivatives all the arylamines tested were effective as acetyl acceptors but aromatic compounds with side-chain amino groups were inactive. 5. The N-hydroxyacetamido derivatives of 2-naphthylamine, 4-amino-biphenyl and 2-aminofluorene were active acetyl donors but N-hydroxyacetanilide showed only slight activity. Acetyl-CoA was not a donor. 6. Some properties of the enzyme are compared with those of other acetyltransferases. PMID:5969287

The Fusarium oxysporum gnt2, Encoding a Putative N-Acetylglucosamine Transferase, Is Involved in Cell Wall Architecture and Virulence

PubMed Central

López-Fernández, Loida; Ruiz-Roldán, Carmen; Pareja-Jaime, Yolanda; Prieto, Alicia; Khraiwesh, Husam; Roncero, M. Isabel G.

2013-01-01

With the aim to decipher the molecular dialogue and cross talk between Fusarium oxysporum f.sp. lycopersci and its host during infection and to understand the molecular bases that govern fungal pathogenicity, we analysed genes presumably encoding N-acetylglucosaminyl transferases, involved in glycosylation of glycoproteins, glycolipids, proteoglycans or small molecule acceptors in other microorganisms. In silico analysis revealed the existence of seven putative N-glycosyl transferase encoding genes (named gnt) in F. oxysporum f.sp. lycopersici genome. gnt2 deletion mutants showed a dramatic reduction in virulence on both plant and animal hosts. Δgnt2 mutants had αalterations in cell wall properties related to terminal αor β-linked N-acetyl glucosamine. Mutant conidia and germlings also showed differences in structure and physicochemical surface properties. Conidial and hyphal aggregation differed between the mutant and wild type strains, in a pH independent manner. Transmission electron micrographs of germlings showed strong cell-to-cell adherence and the presence of an extracellular chemical matrix. Δgnt2 cell walls presented a significant reduction in N-linked oligosaccharides, suggesting the involvement of Gnt2 in N-glycosylation of cell wall proteins. Gnt2 was localized in Golgi-like sub-cellular compartments as determined by fluorescence microscopy of GFP::Gnt2 fusion protein after treatment with the antibiotic brefeldin A or by staining with fluorescent sphingolipid BODIPY-TR ceramide. Furthermore, density gradient ultracentrifugation allowed co-localization of GFP::Gnt2 fusion protein and Vps10p in subcellular fractions enriched in Golgi specific enzymatic activities. Our results suggest that N-acetylglucosaminyl transferases are key components for cell wall structure and influence interactions of F. oxysporum with both plant and animal hosts during pathogenicity. PMID:24416097

Acetylation of Mammalian ADA3 Is Required for Its Functional Roles in Histone Acetylation and Cell Proliferation.

PubMed

Mohibi, Shakur; Srivastava, Shashank; Bele, Aditya; Mirza, Sameer; Band, Hamid; Band, Vimla

2016-10-01

Alteration/deficiency in activation 3 (ADA3) is an essential component of specific histone acetyltransferase (HAT) complexes. We have previously shown that ADA3 is required for establishing global histone acetylation patterns and for normal cell cycle progression (S. Mohibi et al., J Biol Chem 287:29442-29456, 2012, http://dx.doi.org/10.1074/jbc.M112.378901). Here, we report that these functional roles of ADA3 require its acetylation. We show that ADA3 acetylation, which is dynamically regulated in a cell cycle-dependent manner, reflects a balance of coordinated actions of its associated HATs, GCN5, PCAF, and p300, and a new partner that we define, the deacetylase SIRT1. We use mass spectrometry and site-directed mutagenesis to identify major sites of ADA3 acetylated by GCN5 and p300. Acetylation-defective mutants are capable of interacting with HATs and other components of HAT complexes but are deficient in their ability to restore ADA3-dependent global or locus-specific histone acetylation marks and cell proliferation in Ada3-deleted murine embryonic fibroblasts (MEFs). Given the key importance of ADA3-containing HAT complexes in the regulation of various biological processes, including the cell cycle, our study presents a novel mechanism to regulate the function of these complexes through dynamic ADA3 acetylation. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Acetylation of Mammalian ADA3 Is Required for Its Functional Roles in Histone Acetylation and Cell Proliferation

PubMed Central

Mohibi, Shakur; Srivastava, Shashank; Bele, Aditya; Mirza, Sameer; Band, Hamid

2016-01-01

Alteration/deficiency in activation 3 (ADA3) is an essential component of specific histone acetyltransferase (HAT) complexes. We have previously shown that ADA3 is required for establishing global histone acetylation patterns and for normal cell cycle progression (S. Mohibi et al., J Biol Chem 287:29442–29456, 2012, http://dx.doi.org/10.1074/jbc.M112.378901). Here, we report that these functional roles of ADA3 require its acetylation. We show that ADA3 acetylation, which is dynamically regulated in a cell cycle-dependent manner, reflects a balance of coordinated actions of its associated HATs, GCN5, PCAF, and p300, and a new partner that we define, the deacetylase SIRT1. We use mass spectrometry and site-directed mutagenesis to identify major sites of ADA3 acetylated by GCN5 and p300. Acetylation-defective mutants are capable of interacting with HATs and other components of HAT complexes but are deficient in their ability to restore ADA3-dependent global or locus-specific histone acetylation marks and cell proliferation in Ada3-deleted murine embryonic fibroblasts (MEFs). Given the key importance of ADA3-containing HAT complexes in the regulation of various biological processes, including the cell cycle, our study presents a novel mechanism to regulate the function of these complexes through dynamic ADA3 acetylation. PMID:27402865

Social Media–Promoted Weight Loss Among an Occupational Population: Cohort Study Using a WeChat Mobile Phone App-Based Campaign

PubMed Central

Zhao, Yingying; Li, Zheng; Zhang, Yanyan; Le, Jia; Wang, Lei; Wan, Siyang; Li, Changqing; Li, Yindong

2017-01-01

Background Being overweight and obese are major risk factors for noncommunicable diseases such as cardiovascular diseases. The prevalence of overweight and obesity is high throughout the world and these issues are very serious in the Shunyi District in China. As mobile technologies have rapidly developed, mobile apps such as WeChat are well accepted and have the potential to improve health behaviors. Objective This study aims to evaluate the effectiveness of a mobile app (WeChat) as an intervention on weight loss behavior. Methods This study was conducted among an occupational population from August 2015 to February 2016 in the Shunyi District of Beijing. Before the intervention, the Shunyi District Government released an official document for weight loss to all 134 government agencies and enterprises in Shunyi District. Participants willing to use our official WeChat account were enrolled in a WeChat group and received 6 months of interventions for weight loss; those who were not willing to use the account were in a control group given routine publicity on weight loss. Results In total, 15,310 occupational participants including 3467 participants (22.65%) in the control group and 11,843 participants (77.35%) in the WeChat group were enrolled. Participants in the WeChat group lost more weight (mean 2.09, SD 3.43 kg) than people in the control group (mean 1.78, SD 2.96 kg), and the difference in mean weight loss between the two groups for males was significant based on the stratification of age and educational level. To control for confounding factors and to explore the effects of WeChat on weight loss, the propensity score method with a multinominal logistic regression was utilized. For males, this showed that the WeChat group (with both active and inactive subgroups) had a higher probability of maintaining weight, weight loss from 1 to 2 kg, or weight loss more than 2 kg than the control group. However, the control group had higher probability of weight loss from

Chat Reference Training after One Decade: The Results of a National Survey of Academic Libraries

ERIC Educational Resources Information Center

Devine, Christopher; Paladino, Emily Bounds; Davis, John A.

2011-01-01

The first comprehensive national survey of all academic libraries in the United States which were conducting chat reference service was carried out to determine: what practices were being used to prepare personnel for chat reference service, what competencies were being taught, how and why training practices may have changed over time, and what…

Assessing the Language of Chat for Teamwork Dialogue

ERIC Educational Resources Information Center

Shibani, Antonette; Koh, Elizabeth; Lai, Vivian; Shim, Kyong Jin

2017-01-01

In technology-enhanced language learning, many pedagogical activities involve students in online discussion such as synchronous chat, in order to help them practice their language skills. Besides developing the language competency of students, it is also crucial to nurture their teamwork competencies for today's global and complex environment.…

Comprehensive profiling of lysine acetylation suggests the widespread function is regulated by protein acetylation in the silkworm, Bombyx mori.

PubMed

Nie, Zuoming; Zhu, Honglin; Zhou, Yong; Wu, Chengcheng; Liu, Yue; Sheng, Qing; Lv, Zhengbing; Zhang, Wenping; Yu, Wei; Jiang, Caiying; Xie, Longfei; Zhang, Yaozhou; Yao, Juming

2015-09-01

Lysine acetylation in proteins is a dynamic and reversible PTM and plays an important role in diverse cellular processes. In this study, using lysine-acetylation (Kac) peptide enrichment coupled with nano HPLC/MS/MS, we initially identified the acetylome in the silkworms. Overall, a total of 342 acetylated proteins with 667 Kac sites were identified in silkworm. Sequence motifs analysis around Kac sites revealed an enrichment of Y, F, and H in the +1 position, and F was also enriched in the +2 and -2 positions, indicating the presences of preferred amino acids around Kac sites in the silkworm. Functional analysis showed the acetylated proteins were primarily involved in some specific biological processes. Furthermore, lots of nutrient-storage proteins, such as apolipophorin, vitellogenin, storage proteins, and 30 K proteins, were highly acetylated, indicating lysine acetylation may represent a common regulatory mechanism of nutrient utilization in the silkworm. Interestingly, Ser2 proteins, the coating proteins of larval silk, were found to contain many Kac sites, suggesting lysine acetylation may be involved in the regulation of larval silk synthesis. This study is the first to identify the acetylome in a lepidoptera insect, and expands greatly the catalog of lysine acetylation substrates and sites in insects. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

ATP-citrate lyase links cellular metabolism to histone acetylation.

PubMed

Wellen, Kathryn E; Hatzivassiliou, Georgia; Sachdeva, Uma M; Bui, Thi V; Cross, Justin R; Thompson, Craig B

2009-05-22

Histone acetylation in single-cell eukaryotes relies on acetyl coenzyme A (acetyl-CoA) synthetase enzymes that use acetate to produce acetyl-CoA. Metazoans, however, use glucose as their main carbon source and have exposure only to low concentrations of extracellular acetate. We have shown that histone acetylation in mammalian cells is dependent on adenosine triphosphate (ATP)-citrate lyase (ACL), the enzyme that converts glucose-derived citrate into acetyl-CoA. We found that ACL is required for increases in histone acetylation in response to growth factor stimulation and during differentiation, and that glucose availability can affect histone acetylation in an ACL-dependent manner. Together, these findings suggest that ACL activity is required to link growth factor-induced increases in nutrient metabolism to the regulation of histone acetylation and gene expression.

Extraction and properties of protein from camelina engineered to produce acetyl-triacylglycerols (camelina acetyl-TAG)

USDA-ARS?s Scientific Manuscript database

Camelina (Camelina sativa, Brassicaceae) has attracted interest for its seed oil as alternative feedstock for biofuels production. Researchers at Michigan State University successfully engineered camelina to produce seeds with oil containing high levels of acetyl-triacylglerol (acetyl-TAG) by incorp...

Acetylation and characterization of banana (Musa paradisiaca) starch.

PubMed

Bello-Pérez, L A; Contreras-Ramos, S M; Jìmenez-Aparicio, A; Paredes-López, O

2000-01-01

Banana native starch was acetylated and some of its functional properties were evaluated and compared to corn starch. In general, acetylated banana starch presented higher values in ash, protein and fat than corn acetylated starch. The modified starches had minor tendency to retrogradation assessed as % transmittance of starch pastes. At high temperature acetylated starches presented a water retention capacity similar to their native counterpart. The acetylation considerably increased the solubility of starches, and a similar behavior was found for swelling power. When freeze-thaw stability was studied, acetyl banana starch drained approximately 60% of water in the first and second cycles, but in the third and fourth cycles the percentage of separated water was low. However, acetyl corn starch showed lower freeze-thaw stability than the untreated sample. The modification increased the viscosity of banana starch pastes.

Speaking Math: Using Chat in the Multicultural Math Classroom

ERIC Educational Resources Information Center

Graham, Janet; Hodgson, Ted

2008-01-01

Electronic communication is a powerful tool teachers can leverage to improve learning. In this article, the authors explain how they used chat and discussion forums to improve their mathematics classes, and how others can adapt their strategies across the curriculum.

R-U-Typing-2-Me? Evolving a Chat Tool to Increase Understanding in Learning Activities

ERIC Educational Resources Information Center

Fuks, Hugo; Pimentel, Mariano; Lucena, Carlos Jose Pereira de

2006-01-01

Very often, when using a chat tool where more than one participant is talking simultaneously, it is difficult to follow the conversation, read all the different messages and work out who is talking to whom about what. This problem has been dubbed "Chat Confusion." This article investigates this problem in debate sessions in an online university…

Weibo or WeChat? Assessing Preference for Social Networking Sites and Role of Personality Traits and Psychological Factors.

PubMed

Hou, Juan; Ndasauka, Yamikani; Pan, Xuefei; Chen, Shuangyi; Xu, Fei; Zhang, Xiaochu

2018-01-01

Research trying to understand individual difference in the use of different social networking sites (SNSs) is minimal. In the present study, we collected data from 714 college students in China (273 males) to assess how personality traits and psychological factors relate to excessive use of WeChat and Weibo. We found that excessive use of Weibo and WeChat correlated positively with neuroticism, loneliness, and external locus of control and negatively with agreeableness, social support, and social interaction. Furthermore, people that scored high on loneliness, lack of social support, and poor social interaction skills excessively used Weibo more than WeChat. These results entail that by fulfilling different needs, WeChat and Weibo attract different kinds of people; significant lesson for future development of SNSs.

Weibo or WeChat? Assessing Preference for Social Networking Sites and Role of Personality Traits and Psychological Factors

PubMed Central

Hou, Juan; Ndasauka, Yamikani; Pan, Xuefei; Chen, Shuangyi; Xu, Fei; Zhang, Xiaochu

2018-01-01

Research trying to understand individual difference in the use of different social networking sites (SNSs) is minimal. In the present study, we collected data from 714 college students in China (273 males) to assess how personality traits and psychological factors relate to excessive use of WeChat and Weibo. We found that excessive use of Weibo and WeChat correlated positively with neuroticism, loneliness, and external locus of control and negatively with agreeableness, social support, and social interaction. Furthermore, people that scored high on loneliness, lack of social support, and poor social interaction skills excessively used Weibo more than WeChat. These results entail that by fulfilling different needs, WeChat and Weibo attract different kinds of people; significant lesson for future development of SNSs. PMID:29755384

Characterization of the mississippian chat in South-central Kansas

USGS Publications Warehouse

Watney, W.L.; Guy, W.J.; Byrnes, A.P.

2001-01-01

To understand production from low resistivity-high porosity Mississippian chat reservoirs in south-central Kansas it is necessary to understand the nature of deposition and diagenesis, how tectonics is a factor, the lithofacies controls on petrophysical properties, and log response to these properties. The initial mudstones to sponge-spicule wacke-packstones were deposited in transgressive-regressive (T-R) cycles on a shelf to shelf margin setting, resulting in a series of shallowing-upward cycles. Sponge-spicule content appears to increase upward with increasing cycle thickness. After early silicification, inter- and post-Mississippian subaerial exposure resulted in further diagenesis, including sponge-spicule dissolution, vuggy porosity development in moldic-rich rocks, and autobrecciation. Meteoric water infiltration is limited in depth below the exposure surface and in distance downdip into unaltered, cherty Cowley Formation facies. Areas of thicker preserved chat and increased diagenesis can be correlated with structural lineaments and, in some areas, with recurrent basement block movement. Combination of folding or block fault movement prior to or during development of the basal Pennsylvanian unconformity, sponge-spicule concentration, and possibly thickness of overlying bioclastic wacke-grainstones resulted in variable reservoir properties and the creation of pods of production separated by nonproductive cherty dolomite mudstones. These events also resulted in alteration of the depositional cycles to produce a series of lithofacies that exhibit unique petrophysical properties. From bottom to top in a complete cycle seven lithofacies are present: (1) argillaceous dolomite mudstone, (2) argillaceous dolomite mudstone that has chert nodules, (3) clean dolomite mudstone that has nodular chert, (4) nodular to bedded chert, (5) autoclastic chert, (6) autoclastic chert that has clay infill, and (7) bioclastic wacke-grainstone. The uppermost cycle was terminated by

Estimation of volume and mass and of changes in volume and mass of selected chat piles in the Picher mining district, Ottawa County, Oklahoma, 2005-10

USGS Publications Warehouse

Smith, S. Jerrod

2013-01-01

From the 1890s through the 1970s the Picher mining district in northeastern Ottawa County, Oklahoma, was the site of mining and processing of lead and zinc ore. When mining ceased in about 1979, as much as 165–300 million tons of mine tailings, locally referred to as “chat,” remained in the Picher mining district. Since 1979, some chat piles have been mined for aggregate materials and have decreased in volume and mass. Currently (2013), the land surface in the Picher mining district is covered by thousands of acres of chat, much of which remains on Indian trust land owned by allottees. The Bureau of Indian Affairs manages these allotted lands and oversees the sale and removal of chat from these properties. To help the Bureau of Indian Affairs better manage the sale and removal of chat, the U.S. Geological Survey, in cooperation with the Bureau of Indian Affairs, estimated the 2005 and 2010 volumes and masses of selected chat piles remaining on allotted lands in the Picher mining district. The U.S. Geological Survey also estimated the changes in volume and mass of these chat piles for the period 2005 through 2010. The 2005 and 2010 chat-pile volume and mass estimates were computed for 34 selected chat piles on 16 properties in the study area. All computations of volume and mass were performed on individual chat piles and on groups of chat piles in the same property. The Sooner property had the greatest estimated volume (4.644 million cubic yards) and mass (5.253 ± 0.473 million tons) of chat in 2010. Five of the selected properties (Sooner, Western, Lawyers, Skelton, and St. Joe) contained estimated chat volumes exceeding 1 million cubic yards and estimated chat masses exceeding 1 million tons in 2010. Four of the selected properties (Lucky Bill Humbah, Ta Mee Heh, Bird Dog, and St. Louis No. 6) contained estimated chat volumes of less than 0.1 million cubic yards and estimated chat masses of less than 0.1 million tons in 2010. The total volume of all

Social Media-Promoted Weight Loss Among an Occupational Population: Cohort Study Using a WeChat Mobile Phone App-Based Campaign.

PubMed

He, Chao; Wu, Shiyan; Zhao, Yingying; Li, Zheng; Zhang, Yanyan; Le, Jia; Wang, Lei; Wan, Siyang; Li, Changqing; Li, Yindong; Sun, Xinying

2017-10-23

Being overweight and obese are major risk factors for noncommunicable diseases such as cardiovascular diseases. The prevalence of overweight and obesity is high throughout the world and these issues are very serious in the Shunyi District in China. As mobile technologies have rapidly developed, mobile apps such as WeChat are well accepted and have the potential to improve health behaviors. This study aims to evaluate the effectiveness of a mobile app (WeChat) as an intervention on weight loss behavior. This study was conducted among an occupational population from August 2015 to February 2016 in the Shunyi District of Beijing. Before the intervention, the Shunyi District Government released an official document for weight loss to all 134 government agencies and enterprises in Shunyi District. Participants willing to use our official WeChat account were enrolled in a WeChat group and received 6 months of interventions for weight loss; those who were not willing to use the account were in a control group given routine publicity on weight loss. In total, 15,310 occupational participants including 3467 participants (22.65%) in the control group and 11,843 participants (77.35%) in the WeChat group were enrolled. Participants in the WeChat group lost more weight (mean 2.09, SD 3.43 kg) than people in the control group (mean 1.78, SD 2.96 kg), and the difference in mean weight loss between the two groups for males was significant based on the stratification of age and educational level. To control for confounding factors and to explore the effects of WeChat on weight loss, the propensity score method with a multinominal logistic regression was utilized. For males, this showed that the WeChat group (with both active and inactive subgroups) had a higher probability of maintaining weight, weight loss from 1 to 2 kg, or weight loss more than 2 kg than the control group. However, the control group had higher probability of weight loss from 0 to 1 kg. Being active in WeChat was

21 CFR 862.1535 - Ornithine carbamyl transferase test system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Test Systems § 862.1535 Ornithine carbamyl transferase test system. (a) Identification. An ornithine carbamyl transferase test system is a device intended to measure the activity of the enzyme ornithine... and treatment of liver diseases, such as infectious hepatitis, acute cholecystitis (inflammation of...

Online Chats to Assess Stakeholder Perceptions of Meat Chicken Intensification and Welfare.

PubMed

Howell, Tiffani J; Rohlf, Vanessa I; Coleman, Grahame J; Rault, Jean-Loup

2016-10-27

Evidence suggests that there is variation in support for specific chicken farming practices amongst stakeholder groups, and this should be explored in more detail to understand the nature of these differences and work towards convergence. Online focus groups were used to assess attitudes to animal welfare in meat chicken farming in this pilot study. Across six online chats, 25 participants (general public, n = 8; animal advocacy group, n = 11, meat chicken industry, n = 3; research or veterinary practice who had experience with poultry but no declared industry affiliation, n = 3) discussed meat chicken intensification and welfare. Of those, 21 participants completed pre- and post-chat surveys gauging perceptions and objective knowledge about meat chicken management. Main reasons for intensification support were perceptions of improved bird health, and perceptions that it is a cost-effective, sustainable farming system. Reasons for opposition included perceptions that a large number of birds kept are in close proximity and have limited ability to perform natural behaviours. Misunderstandings about current practices were clarified in chats which contained industry representation. Participants agreed on the need for enforceable standards and industry transparency. Industry-affiliated members rated welfare of meat chickens higher, and gave lower ratings for the importance of natural living, than other stakeholder groups (both p = 0.001). On average, while objective knowledge of intensification increased after chat participation (p = 0.03), general welfare ratings and support for intensification did not change over time, counter to assertions that lack of knowledge results in lack of support for some practices.

Aldehyde-alcohol dehydrogenase and/or thiolase overexpression coupled with CoA transferase downregulation lead to higher alcohol titers and selectivity in Clostridium acetobutylicum fermentations.

PubMed

Sillers, Ryan; Al-Hinai, Mohab Ali; Papoutsakis, Eleftherios T

2009-01-01

Metabolic engineering (ME) of Clostridium acetobutylicum has led to increased solvent (butanol, acetone, and ethanol) production and solvent tolerance, thus demonstrating that further efforts have the potential to create strains of industrial importance. With recently developed ME tools, it is now possible to combine genetic modifications and thus implement more advanced ME strategies. We have previously shown that antisense RNA (asRNA)-based downregulation of CoA transferase (CoAT, the first enzyme in the acetone-formation pathway) results in increased butanol to acetone selectivity, but overall reduced butanol yields and titers. In this study the alcohol/aldehyde dehydrogenase (aad) gene (encoding the bifunctional protein AAD responsible for butanol and ethanol production from butyryl-CoA and acetyl-CoA, respectively) was expressed from the phosphotransbutyrylase (ptb) promoter to enhance butanol formation and selectivity, while CoAT downregulation was used to minimize acetone production. This led to early production of high alcohol (butanol plus ethanol) titers, overall solvent titers of 30 g/L, and a higher alcohol/acetone ratio. Metabolic flux analysis revealed the likely depletion of butyryl-CoA. In order to increase then the flux towards butyryl-CoA, we examined the impact of thiolase (THL, thl) overexpression. THL converts acetyl-CoA to acetoacetyl-CoA, the first step of the pathway from acetyl-CoA to butyryl-CoA, and thus, combining thl overexpression with aad overexpression decreased, as expected, acetate and ethanol production while increasing acetone and butyrate formation. thl overexpression in strains with asRNA CoAT downregulation did not significantly alter product formation thus suggesting that a more complex metabolic engineering strategy is necessary to enhance the intracellular butyryl-CoA pool and reduce the acetyl-CoA pool in order to achieve improved butanol titers and selectivity.

Nonhistone protein acetylation as cancer therapy targets

PubMed Central

Singh, Brahma N; Zhang, Guanghua; Hwa, Yi L; Li, Jinping; Dowdy, Sean C; Jiang, Shi-Wen

2012-01-01

Acetylation and deacetylation are counteracting, post-translational modifications that affect a large number of histone and nonhistone proteins. The significance of histone acetylation in the modification of chromatin structure and dynamics, and thereby gene transcription regulation, has been well recognized. A steadily growing number of nonhistone proteins have been identified as acetylation targets and reversible lysine acetylation in these proteins plays an important role(s) in the regulation of mRNA stability, protein localization and degradation, and protein–protein and protein–DNA interactions. The recruitment of histone acetyltransferases (HATs) and histone deacetylases (HDACs) to the transcriptional machinery is a key element in the dynamic regulation of genes controlling cellular proliferation, differentiation and apoptosis. Many nonhistone proteins targeted by acetylation are the products of oncogenes or tumor-suppressor genes and are directly involved in tumorigenesis, tumor progression and metastasis. Aberrant activity of HDACs has been documented in several types of cancers and HDAC inhibitors (HDACi) have been employed for therapeutic purposes. Here we review the published literature in this field and provide updated information on the regulation and function of nonhistone protein acetylation. While concentrating on the molecular mechanism and pathways involved in the addition and removal of the acetyl moiety, therapeutic modalities of HDACi are also discussed. PMID:20553216

Design and development of data acquisition system based on WeChat hardware

NASA Astrophysics Data System (ADS)

Wang, Zhitao; Ding, Lei

2018-06-01

Data acquisition system based on WeChat hardware provides methods for popularization and practicality of data acquisition. The whole system is based on WeChat hardware platform, where the hardware part is developed on DA14580 development board and the software part is based on Alibaba Cloud. We designed service module, logic processing module, data processing module and database module. The communication between hardware and software uses AirSync Protocal. We tested this system by collecting temperature and humidity data, and the result shows that the system can aquisite the temperature and humidity in real time according to settings.

Ancient Regulatory Role of Lysine Acetylation in Central Metabolism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakayasu, Ernesto S.; Burnet, Meagan C.; Walukiewicz, Hanna E.

ABSTRACT Lysine acetylation is a common protein post-translational modification in bacteria and eukaryotes. Unlike phosphorylation, whose functional role in signaling has been established, it is unclear what regulatory mechanism acetylation plays and whether it is conserved across evolution. By performing a proteomic analysis of 48 phylogenetically distant bacteria, we discovered conserved acetylation sites on catalytically essential lysine residues that are invariant throughout evolution. Lysine acetylation removes the residue’s charge and changes the shape of the pocket required for substrate or cofactor binding. Two-thirds of glycolytic and tricarboxylic acid (TCA) cycle enzymes are acetylated at these critical sites. Our data suggestmore » that acetylation may play a direct role in metabolic regulation by switching off enzyme activity. We propose that protein acetylation is an ancient and widespread mechanism of protein activity regulation. IMPORTANCEPost-translational modifications can regulate the activity and localization of proteins inside the cell. Similar to phosphorylation, lysine acetylation is present in both eukaryotes and prokaryotes and modifies hundreds to thousands of proteins in cells. However, how lysine acetylation regulates protein function and whether such a mechanism is evolutionarily conserved is still poorly understood. Here, we investigated evolutionary and functional aspects of lysine acetylation by searching for acetylated lysines in a comprehensive proteomic data set from 48 phylogenetically distant bacteria. We found that lysine acetylation occurs in evolutionarily conserved lysine residues in catalytic sites of enzymes involved in central carbon metabolism. Moreover, this modification inhibits enzymatic activity. Our observations suggest that lysine acetylation is an evolutionarily conserved mechanism of controlling central metabolic activity by directly blocking enzyme active sites.« less

Ancient Regulatory Role of Lysine Acetylation in Central Metabolism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakayasu, Ernesto S.; Burnet, Meagan C.; Walukiewicz, Hanna E.

ABSTRACT Lysine acetylation is a common protein post-translational modification in bacteria and eukaryotes. Unlike phosphorylation, whose functional role in signaling has been established, it is unclear what regulatory mechanism acetylation plays and whether it is conserved across evolution. By performing a proteomic analysis of 48 phylogenetically distant bacteria, we discovered conserved acetylation sites on catalytically essential lysine residues that are invariant throughout evolution. Lysine acetylation removes the residue’s charge and changes the shape of the pocket required for substrate or cofactor binding. Two-thirds of glycolytic and tricarboxylic acid (TCA) cycle enzymes are acetylated at these critical sites. Our data suggestmore » that acetylation may play a direct role in metabolic regulation by switching off enzyme activity. We propose that protein acetylation is an ancient and widespread mechanism of protein activity regulation. IMPORTANCE Post-translational modifications can regulate the activity and localization of proteins inside the cell. Similar to phosphorylation, lysine acetylation is present in both eukaryotes and prokaryotes and modifies hundreds to thousands of proteins in cells. However, how lysine acetylation regulates protein function and whether such a mechanism is evolutionarily conserved is still poorly understood. Here, we investigated evolutionary and functional aspects of lysine acetylation by searching for acetylated lysines in a comprehensive proteomic data set from 48 phylogenetically distant bacteria. We found that lysine acetylation occurs in evolutionarily conserved lysine residues in catalytic sites of enzymes involved in central carbon metabolism. Moreover, this modification inhibits enzymatic activity. Our observations suggest that lysine acetylation is an evolutionarily conserved mechanism of controlling central metabolic activity by directly blocking enzyme active sites.« less

Ancient Regulatory Role of Lysine Acetylation in Central Metabolism

DOE PAGES

Nakayasu, Ernesto S.; Burnet, Meagan C.; Walukiewicz, Hanna E.; ...

2017-11-28

ABSTRACT Lysine acetylation is a common protein post-translational modification in bacteria and eukaryotes. Unlike phosphorylation, whose functional role in signaling has been established, it is unclear what regulatory mechanism acetylation plays and whether it is conserved across evolution. By performing a proteomic analysis of 48 phylogenetically distant bacteria, we discovered conserved acetylation sites on catalytically essential lysine residues that are invariant throughout evolution. Lysine acetylation removes the residue’s charge and changes the shape of the pocket required for substrate or cofactor binding. Two-thirds of glycolytic and tricarboxylic acid (TCA) cycle enzymes are acetylated at these critical sites. Our data suggestmore » that acetylation may play a direct role in metabolic regulation by switching off enzyme activity. We propose that protein acetylation is an ancient and widespread mechanism of protein activity regulation. IMPORTANCE Post-translational modifications can regulate the activity and localization of proteins inside the cell. Similar to phosphorylation, lysine acetylation is present in both eukaryotes and prokaryotes and modifies hundreds to thousands of proteins in cells. However, how lysine acetylation regulates protein function and whether such a mechanism is evolutionarily conserved is still poorly understood. Here, we investigated evolutionary and functional aspects of lysine acetylation by searching for acetylated lysines in a comprehensive proteomic data set from 48 phylogenetically distant bacteria. We found that lysine acetylation occurs in evolutionarily conserved lysine residues in catalytic sites of enzymes involved in central carbon metabolism. Moreover, this modification inhibits enzymatic activity. Our observations suggest that lysine acetylation is an evolutionarily conserved mechanism of controlling central metabolic activity by directly blocking enzyme active sites.« less

21 CFR 862.1535 - Ornithine carbamyl transferase test system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ornithine carbamyl transferase test system. 862.1535 Section 862.1535 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Test Systems § 862.1535 Ornithine carbamyl transferase test system. (a) Identification. An ornithine...

21 CFR 862.1535 - Ornithine carbamyl transferase test system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ornithine carbamyl transferase test system. 862.1535 Section 862.1535 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Test Systems § 862.1535 Ornithine carbamyl transferase test system. (a) Identification. An ornithine...

Effects of Face-to-Face versus Chat Communication on Performance in a Collaborative Inquiry Modeling Task

ERIC Educational Resources Information Center

Sins, Patrick H. M.; Savelsbergh, Elwin R.; van Joolingen, Wouter R.; van Hout-Wolters, Bernadette H. A. M.

2011-01-01

In many contemporary collaborative inquiry learning environments, chat is being used as a means for communication. Still, it remains an open issue whether chat communication is an appropriate means to support the deep reasoning process students need to perform in such environments. Purpose of the present study was to compare the impact of chat…

Color Visions from the Past in Science Teaching within a Cultural Historical Activity Theory (CHAT) Context

ERIC Educational Resources Information Center

Kolokouri, Eleni; Plakitsi, Katerina

2012-01-01

This study uses history of science in teaching natural sciences from the early grades. The theoretical framework used is Cultural Historical Activity Theory (CHAT), which is a theory with expanding applications in different fields of science. The didactical scenario, in which history of science is used in a CHAT context, refers to Newton's…

Combinatorial Therapy with Acetylation and Methylation Modifiers Attenuates Lung Vascular Hyperpermeability in Endotoxemia-Induced Mouse Inflammatory Lung Injury

PubMed Central

Thangavel, Jayakumar; Malik, Asrar B.; Elias, Harold K.; Rajasingh, Sheeja; Simpson, Andrew D.; Sundivakkam, Premanand K.; Vogel, Stephen M.; Xuan, Yu-Ting; Dawn, Buddhadeb; Rajasingh, Johnson

2015-01-01

Impairment of tissue fluid homeostasis and migration of inflammatory cells across the vascular endothelial barrier are crucial factors in the pathogenesis of acute lung injury (ALI). The goal for treatment of ALI is to target pathways that lead to profound dysregulation of the lung endothelial barrier. Although studies have shown that chemical epigenetic modifiers can limit lung inflammation in experimental ALI models, studies to date have not examined efficacy of a combination of DNA methyl transferase inhibitor 5-Aza 2-deoxycytidine and histone deacetylase inhibitor trichostatin A (herein referred to as Aza+TSA) after endotoxemia-induced mouse lung injury. We tested the hypothesis that treatment with Aza+TSA after lipopolysaccharide induction of ALI through epigenetic modification of lung endothelial cells prevents inflammatory lung injury. Combinatorial treatment with Aza+TSA mitigated the increased endothelial permeability response after lipopolysaccharide challenge. In addition, we observed reduced lung inflammation and lung injury. Aza+TSA also significantly reduced mortality in the ALI model. The protection was ascribed to inhibition of the eNOS-Cav1-MLC2 signaling pathway and enhanced acetylation of histone markers on the vascular endothelial-cadherin promoter. In summary, these data show for the first time the efficacy of combinatorial Aza+TSA therapy in preventing ALI in lipopolysaccharide-induced endotoxemia and raise the possibility of an essential role of DNA methyl transferase and histone deacetylase in the mechanism of ALI. PMID:24929240

Polymorphisms of glutathione S-transferase Mu 1, glutathione S-transferase theta 1 and glutathione S-transferase Pi 1 genes in Hodgkin's lymphoma susceptibility and progression.

PubMed

Lourenço, Gustavo J; Néri, Iramaia A; Sforni, Vitor C S; Kameo, Rodolfo; Lorand-Metze, Irene; Lima, Carmen S P

2009-06-01

We tested in this study whether the polymorphisms of the glutathione S-transferase Mu1 (GSTM1), glutathione S-transferase Theta 1 (GSTT1) and glutathione S-transferase Pi 1 (GSTP1), involved in metabolism of chemical agents, cell proliferation and cell survival, alter the risk for Hodgkin lymphoma (HL). Genomic DNA from 110 consecutive patients with HL and 226 controls was analysed by polymerase chain reaction and restriction digestion for the polymorphism analyses. Similar frequencies of the GSTM1 and GSTT1 genotypes were seen in patients and controls. In contrast, the frequency of the GSTP1 wild genotype (59.1%versus 36.3%, P = 0.004) was higher in patients than in controls. Individuals with the wild genotype had a 2.68 (95%CI: 1.38-5.21)-fold increased risk for the disease than others. An excess of the GSTP1 wild genotype was also observed in patients with tumors of stages III + IV when compared with those with tumors of stages I + II (39.1%versus 20.0%, P = 0.03). These results suggest that the wild allele of the GSTP1 gene is linked to an increased risk and high aggressiveness of the HL in our cases but they should be confirmed by further studies with larger cohorts of patients and controls.

Global analysis of lysine acetylation in strawberry leaves.

PubMed

Fang, Xianping; Chen, Wenyue; Zhao, Yun; Ruan, Songlin; Zhang, Hengmu; Yan, Chengqi; Jin, Liang; Cao, Lingling; Zhu, Jun; Ma, Huasheng; Cheng, Zhongyi

2015-01-01

Protein lysine acetylation is a reversible and dynamic post-translational modification. It plays an important role in regulating diverse cellular processes including chromatin dynamic, metabolic pathways, and transcription in both prokaryotes and eukaryotes. Although studies of lysine acetylome in plants have been reported, the throughput was not high enough, hindering the deep understanding of lysine acetylation in plant physiology and pathology. In this study, taking advantages of anti-acetyllysine-based enrichment and high-sensitive-mass spectrometer, we applied an integrated proteomic approach to comprehensively investigate lysine acetylome in strawberry. In total, we identified 1392 acetylation sites in 684 proteins, representing the largest dataset of acetylome in plants to date. To reveal the functional impacts of lysine acetylation in strawberry, intensive bioinformatic analysis was performed. The results significantly expanded our current understanding of plant acetylome and demonstrated that lysine acetylation is involved in multiple cellular metabolism and cellular processes. More interestingly, nearly 50% of all acetylated proteins identified in this work were localized in chloroplast and the vital role of lysine acetylation in photosynthesis was also revealed. Taken together, this study not only established the most extensive lysine acetylome in plants to date, but also systematically suggests the significant and unique roles of lysine acetylation in plants.

Perfume formulation: words and chats.

PubMed

Ellena, Céline

2008-06-01

What does it mean to create fragrances with materials from chemistry and/or from nature? How are they used to display their characteristic differences, their own personality? Is it easier to create with synthetic raw materials or with essential oils? This review explains why a perfume formulation corresponds in fact to a conversation, an interplay between synthetic and natural perfumery materials. A synthetic raw material carries a single information, and usually is very linear. Its smell is uniform, clear, and faithful. Natural raw materials, on the contrary, provide a strong, complex and generous image. While a synthetic material can be seen as a single word, a natural one such as rose oil could be compared to chatting: cold, warm, sticky, heavy, transparent, pepper, green, metallic, smooth, watery, fruity... full of information. Yet, if a very small amount of the natural material is used, nothing happens, the fragrance will not change. However, if a large amount is used, the rose oil will swallow up everything else. The fragrance will smell of nothing else except rose! To formulate a perfume is not to create a culinary recipe, with only dosing the ingredients in well-balanced amounts. To formulate rather means to flexibly knit materials together with a lively stitch, meeting or repelling each other, building a pleasant form, which is neither fixed, nor solid, nor rigid. A fragrance has an overall structure, which ranges from a clear sound, made up of stable, unique, and linear items, to a background chat, comfortable and reassuring. But that does, of course, not mean that there is only one way of creating a fragrance!

About Collaboration, Interaction, and the Negotiation of Meaning in Synchronous Written Chats in L2-German

ERIC Educational Resources Information Center

Fredriksson, Christine

2012-01-01

In this paper I will show the preliminary findings from my study of the discourse in synchronous written chats performed by students who study modern German literature within their first term of German studies. The focus of the study is on learning strategies and discourse strategies and how the Swedish learners make use of them when chatting with…

Observations of Chat Room Conversations on the Internet: Implications for Educators Addressing the Needs of Female Adolescents

ERIC Educational Resources Information Center

Sanger, Dixie; Ritzman, Mitzi; LaCost, Barbara; Stofer, Keri; Long, Amie; Grady, Marilyn

2005-01-01

This qualitative study explored the meanings of chat room conversations through observations of teenagers using the Internet. Adolescent girls were a focus because of their shaky sense of self. Participants in ten chat rooms included 534 individuals. Six themes, emerging from analyzing 2526 utterances [descriptive statements], included (a)…

Functional Characterization of ATM Kinase Using Acetylation-Specific Antibodies.

PubMed

Sun, Yingli; Du, Fengxia

2017-01-01

The activation of ATM is critical in the DNA double strand breaks repair pathway. Acetylation of ATM by Tip60 histone acetyltransferase (HAT) plays a key role in the activation of ATM kinase activity in response to DNA damage. ATM forms a stable complex with Tip60 through the FATC domain of ATM. Tip60 acetylates lysine3016 of ATM, and this acetylation induces the activation of ATM. Several techniques are included in the study of ATM acetylation by Tip60, such as in vitro kinase assay, systematic mutagenesis, western blots. Here, we describe how to study the acetylation of ATM using acetylation-specific antibodies.

Effects of using WeChat-assisted perioperative care instructions for parents of pediatric patients undergoing day surgery for herniorrhaphy.

PubMed

Liu, Jun; Zheng, Xin; Chai, Shouxia; Lei, Meirong; Feng, Zehui; Zhang, Xuelin; Lopez, Violeta

2018-02-19

This study examined the effects of WeChat-assisted perioperative instructions for parents whose children were to undergo herniorrhaphy. A randomized controlled trial was conducted in a day surgery center in China. Participants were randomly assigned to the intervention (WeChat) group (n = 209) and the control (Leaflet) group (n = 209). The primary outcomes of this study were parents' knowledge regarding hernia and rate of cancellation of children's surgery. The secondary outcomes were the rate of lost-to-follow-up and the rate of complications and adverse events during the seventh postoperative follow-up day. There was a significant difference in the rate of cancelling the surgery and the mean knowledge score between the WeChat group and leaflet groups. The lost-to-follow-up rate was significantly lower in the WeChat group (0.54%) than in the leaflet group (3.66%). The incidence of postoperative complications were higher in the control group. WeChat-assisted perioperative care instructions enhanced parents' knowledge on perioperative instructions and promoted the preparation of their children for day surgery resulting in lower rate of cancelling the surgery. WeChat has the ability to expand health services outside the hospital confines and could be used as an important low-cost health educational medium in China. Copyright © 2018 Elsevier B.V. All rights reserved.

Acetyl diacylglycerol produced by modified camelina (Camelina sativa)

USDA-ARS?s Scientific Manuscript database

Acetyl diacylglyceride (Acetyl-TAG) is a component of a commercial product, ACETEM, manufactured by transesterification reaction of triglycerides, glycerol, and triacetin or by acetylation of mono- and diglycerides with acetic acid anhydride. ACETEM is commonly used as foaming agents and coatings in...

"Siamo Vicini, No?": Negotiating Commonality for Rapport Building in Italian L1-L2 Online Text Chat

ERIC Educational Resources Information Center

Tudini, Vincenza; Strambi, Antonella

2017-01-01

Focusing specifically on the negotiation of commonality, this study explores rapport building (Spencer-Oatey, 2000) in online intercultural text chat, where Australian students of Italian interact with L1 Italian speakers. Although the initial purpose of the examined chat exchanges is to facilitate L2 acquisition, analysis of transcripts indicates…

Survey of the human acetylator polymorphism in spontaneous disorders.

PubMed Central

Evans, D A

1984-01-01

There is ample evidence that the human acetylator phenotypes are associated with drug induced phenomena. It is principally the slow acetylators who exhibit toxic adverse effects because of their relative inability to detoxify the original drug compounds. In rare instances, however, it is the rapid acetylators who are at a disadvantage. In the matter of association of spontaneous disease with either acetylator phenotype, there are two groups of disorders to consider. First, disorders in which carcinogenic amines are known to be an aetiological factor. This is because these amines are substrates for the polymorphic N-acetyltransferase activity and hence there is a possible rational basis for searching for an association. Secondly, other disorders where searches for associations are based more on hunches. In the first group there is a definite statistical association between cancer of the bladder and the slow acetylator phenotype. In prevalence studies the slow phenotype is 39% more associated with bladder cancer than is the rapid phenotype. On the basis of the evidence now available it is not possible to say whether this association is because slow acetylators develop the disease more frequently or whether they survive longer. In the second group the relevant studies show (1) a greatly increased prevalence of slow acetylators in Gilbert's disease; (2) a confirmed association between the rapid acetylator phenotype and diabetes; (3) a possible association between the rapid acetylator phenotype and breast cancer; (4) a possible association between the slow acetylator phenotype and leprosy in Chinese patients; (5) an earlier age of onset of thyrotoxicosis (Graves' disease) in slow acetylators than in rapid acetylators; (6) no evidence of an association between either phenotype and spontaneous systemic lupus erythematosus. PMID:6387123

Acetylation Suppresses the Proapoptotic Activity of GD3 Ganglioside

PubMed Central

Malisan, Florence; Franchi, Luigi; Tomassini, Barbara; Ventura, Natascia; Condò, Ivano; Rippo, Maria Rita; Rufini, Alessandra; Liberati, Laura; Nachtigall, Claudia; Kniep, Bernhard; Testi, Roberto

2002-01-01

GD3 synthase is rapidly activated in different cell types after specific apoptotic stimuli. De novo synthesized GD3 accumulates and contributes to the apoptotic program by relocating to mitochondrial membranes and inducing the release of apoptogenic factors. We found that sialic acid acetylation suppresses the proapoptotic activity of GD3. In fact, unlike GD3, 9-O-acetyl-GD3 is completely ineffective in inducing cytochrome c release and caspase-9 activation on isolated mitochondria and fails to induce the collapse of mitochondrial transmembrane potential and cellular apoptosis. Moreover, cells which are resistant to the overexpression of the GD3 synthase, actively convert de novo synthesized GD3 to 9-O-acetyl-GD3. The coexpression of GD3 synthase with a viral 9-O-acetyl esterase, which prevents 9-O-acetyl-GD3 accumulation, reconstitutes GD3 responsiveness and apoptosis. Finally, the expression of the 9-O-acetyl esterase is sufficient to induce apoptosis of glioblastomas which express high levels of 9-O-acetyl-GD3. Thus, sialic acid acetylation critically controls the proapoptotic activity of GD3. PMID:12486096

Separation and characterization of acetyl and non-acetyl hemicelluloses of Arundo donax by ammonium sulfate precipitation.

PubMed

Peng, Feng; Bian, Jing; Peng, Pai; Xiao, Huan; Ren, Jun-Li; Xu, Feng; Sun, Run-Cang

2012-04-25

Delignified Arundo donax was sequentially extracted with DMSO, saturated barium hydroxide, and 1.0 M aqueous NaOH solution. The yields of the soluble fractions were 10.2, 6.7, and 10.0% (w/w), respectively, of the dry Arundo donax materials. The DMSO-, Ba(OH)(2)- and NaOH-soluble hemicellulosic fractions were further fractionated into two subfractions by gradient 50% and 80% saturation ammonium sulfate precipitation, respectively. Monosaccharide, molecular weight, FT-IR, and 1D ((1)H and (13)C) and 2D (HSQC) NMR analysis revealed the differences in structural characteristics and physicochemical properties among the subfractions. The subfractions precipitated with 50% saturation ammonium sulfate had lower arabinose/xylose and glucuronic acid/xylose ratios but had higher molecular weight than those of the subfractions precipitated by 80% saturation ammonium sulfate. FT-IR and NMR analysis revealed that the highly acetylated DMSO-soluble hemicellulosic subfraction (H(D50)) could be precipitated with a relatively lower concentration of 50% saturated ammonium sulfate, and thus the gradient ammonium sulfate precipitation technique could discriminate acetyl and non-acetyl hemicelluloses. It was found that the DMSO-soluble subfraction H(D50) precipitated by 50% saturated ammonium sulfate mainly consisted of poorly substituted O-acetyl arabino-4-O-methylglucurono xylan with terminal units of arabinose linked on position 3 of xylose, 4-O-methylglucuronic acid residues linked on position 2 of the xylan bone, and the acetyl groups (degree of acetylation, 37%) linked on position 2 or 3. The DMSO-soluble subfraction H(D80) precipitated by 80% saturated ammonium sulfate was mainly composed of highly substituted arabino-4-O-methylglucurono xylan and β-d-glucan.

Comparative analysis of pharmacological treatments with N-acetyl-DL-leucine (Tanganil) and its two isomers (N-acetyl-L-leucine and N-acetyl-D-leucine) on vestibular compensation: Behavioral investigation in the cat.

PubMed

Tighilet, Brahim; Leonard, Jacques; Bernard-Demanze, Laurence; Lacour, Michel

2015-12-15

Head roll tilt, postural imbalance and spontaneous nystagmus are the main static vestibular deficits observed after an acute unilateral vestibular loss (UVL). In the UVL cat model, these deficits are fully compensated over 6 weeks as the result of central vestibular compensation. N-Acetyl-dl-leucine is a drug prescribed in clinical practice for the symptomatic treatment of acute UVL patients. The present study investigated the effects of N-acetyl-dl-leucine on the behavioral recovery after unilateral vestibular neurectomy (UVN) in the cat, and compared the effects of each of its two isomers N-acetyl-L-leucine and N-acetyl-D-leucine. Efficacy of these three drug treatments has been evaluated with respect to a placebo group (UVN+saline water) on the global sensorimotor activity (observation grids), the posture control (support surface measurement), the locomotor balance (maximum performance at the rotating beam test), and the spontaneous vestibular nystagmus (recorded in the light). Whatever the parameters tested, the behavioral recovery was strongly and significantly accelerated under pharmacological treatments with N-acetyl-dl-leucine and N-acetyl-L-leucine. In contrast, the N-acetyl-D-leucine isomer had no effect at all on the behavioral recovery, and animals of this group showed the same recovery profile as those receiving a placebo. It is concluded that the N-acetyl-L-leucine isomer is the active part of the racemate component since it induces a significant acceleration of the vestibular compensation process similar (and even better) to that observed under treatment with the racemate component only. Copyright © 2015 Elsevier B.V. All rights reserved.

Expression of mung bean pectin acetyl esterase in potato tubers: effect on acetylation of cell wall polymers and tuber mechanical properties.

PubMed

Orfila, Caroline; Dal Degan, Florence; Jørgensen, Bodil; Scheller, Henrik Vibe; Ray, Peter M; Ulvskov, Peter

2012-07-01

A mung bean (Vigna radiata) pectin acetyl esterase (CAA67728) was heterologously expressed in tubers of potato (Solanum tuberosum) under the control of the granule-bound starch synthase promoter or the patatin promoter in order to probe the significance of O-acetylation on cell wall and tissue properties. The recombinant tubers showed no apparent macroscopic phenotype. The enzyme was recovered from transgenic tubers using a high ionic strength buffer and the extract was active against a range of pectic substrates. Partial in vivo de-acetylation of cell wall polysaccharides occurred in the transformants, as shown by a 39% decrease in the degree of acetylation (DA) of tuber cell wall material (CWM). Treatment of CWM using a combination of endo-polygalacturonase and pectin methyl esterase extracted more pectin polymers from the transformed tissue compared to wild type. The largest effect of the pectin acetyl esterase (68% decrease in DA) was seen in the residue from this extraction, suggesting that the enzyme is preferentially active on acetylated pectin that is tightly bound to the cell wall. The effects of acetylation on tuber mechanical properties were investigated by tests of failure under compression and by determination of viscoelastic relaxation spectra. These tests suggested that de-acetylation resulted in a stiffer tuber tissue and a stronger cell wall matrix, as a result of changes to a rapidly relaxing viscoelastic component. These results are discussed in relation to the role of pectin acetylation in primary cell walls and its implications for industrial uses of potato fibres.

Acetyl chloride

Integrated Risk Information System (IRIS)

Acetyl chloride ; CASRN 75 - 36 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

Modelling of information diffusion on social networks with applications to WeChat

NASA Astrophysics Data System (ADS)

Liu, Liang; Qu, Bo; Chen, Bin; Hanjalic, Alan; Wang, Huijuan

2018-04-01

Traces of user activities recorded in online social networks open new possibilities to systematically understand the information diffusion process on social networks. From the online social network WeChat, we collected a large number of information cascade trees, each of which tells the spreading trajectory of a message/information such as which user creates the information and which users view or forward the information shared by which neighbours. In this work, we propose two heterogeneous non-linear models, one for the topologies of the information cascade trees and the other for the stochastic process of information diffusion on a social network. Both models are validated by the WeChat data in reproducing and explaining key features of cascade trees. Specifically, we apply the Random Recursive Tree (RRT) to model the growth of cascade trees. The RRT model could capture key features, i.e. the average path length and degree variance of a cascade tree in relation to the number of nodes (size) of the tree. Its single identified parameter quantifies the relative depth or broadness of the cascade trees and indicates that information propagates via a star-like broadcasting or viral-like hop by hop spreading. The RRT model explains the appearance of hubs, thus a possibly smaller average path length as the cascade size increases, as observed in WeChat. We further propose the stochastic Susceptible View Forward Removed (SVFR) model to depict the dynamic user behaviour including creating, viewing, forwarding and ignoring a message on a given social network. Beside the average path length and degree variance of the cascade trees in relation to their sizes, the SVFR model could further explain the power-law cascade size distribution in WeChat and unravel that a user with a large number of friends may actually have a smaller probability to read a message (s)he receives due to limited attention.

Interaction Management Strategies on IRC and Virtual Chat Rooms.

ERIC Educational Resources Information Center

Altun, Arif

Internet Relay Chat (IRC) is an electronic medium that combines orthographic form with real time, synchronous transmission in an unregulated global multi-user environment. The orthographic letters mediate the interaction in that users can only access the IRC session through reading and writing; they have no access to any visual representations at…

Investigating the Building of a WeChat-Based Community of Practice for Language Teachers' Professional Development

ERIC Educational Resources Information Center

Qi, Grace Yue; Wang, Yuping

2018-01-01

This study explores the process of Community of Practice (CoP) building for language teachers' professional development through the support of a WeChat group. WeChat is an instant messenger app that provides a multimodal platform for one-on-one and group interactions through text, audio and video. In order to support the implementation of flipped…

The Acetyl Group Buffering Action of Carnitine Acetyltransferase Offsets Macronutrient-Induced Lysine Acetylation of Mitochondrial Proteins.

PubMed

Davies, Michael N; Kjalarsdottir, Lilja; Thompson, J Will; Dubois, Laura G; Stevens, Robert D; Ilkayeva, Olga R; Brosnan, M Julia; Rolph, Timothy P; Grimsrud, Paul A; Muoio, Deborah M

2016-01-12

Lysine acetylation (AcK), a posttranslational modification wherein a two-carbon acetyl group binds covalently to a lysine residue, occurs prominently on mitochondrial proteins and has been linked to metabolic dysfunction. An emergent theory suggests mitochondrial AcK occurs via mass action rather than targeted catalysis. To test this hypothesis, we performed mass spectrometry-based acetylproteomic analyses of quadriceps muscles from mice with skeletal muscle-specific deficiency of carnitine acetyltransferase (CrAT), an enzyme that buffers the mitochondrial acetyl-CoA pool by converting short-chain acyl-CoAs to their membrane permeant acylcarnitine counterparts. CrAT deficiency increased tissue acetyl-CoA levels and susceptibility to diet-induced AcK of broad-ranging mitochondrial proteins, coincident with diminished whole body glucose control. Sub-compartment acetylproteome analyses of muscles from obese mice and humans showed remarkable overrepresentation of mitochondrial matrix proteins. These findings reveal roles for CrAT and L-carnitine in modulating the muscle acetylproteome and provide strong experimental evidence favoring the nonenzymatic carbon pressure model of mitochondrial AcK. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

The Acetyl Group Buffering Action of Carnitine Acetyltransferase Offsets Macronutrient-induced Lysine Acetylation of Mitochondrial Proteins

PubMed Central

Davies, Michael N.; Kjalarsdottir, Lilja; Thompson, J. Will; Dubois, Laura G.; Stevens, Robert D.; Ilkayeva, Olga R.; Brosnan, M. Julia; Rolph, Timothy P.; Grimsrud, Paul A.; Muoio, Deborah M.

2016-01-01

Lysine acetylation (AcK), a posttranslational modification wherein a two-carbon acetyl group binds covalently to a lysine residue, occurs prominently on mitochondrial proteins and has been linked to metabolic dysfunction. An emergent theory suggests mitochondrial AcK occurs via mass action rather than targeted catalysis. To test this hypothesis we performed mass spectrometry-based acetylproteomic analyses of quadriceps muscles from mice with skeletal muscle-specific deficiency of carnitine acetyltransferase (CrAT), an enzyme that buffers the mitochondrial acetyl-CoA pool by converting short-chain acyl-CoAs to their membrane permeant acylcarnitine counterparts. CrAT deficiency increased tissue acetyl-CoA levels and susceptibility to diet-induced AcK of broad-ranging mitochondrial proteins, coincident with diminished whole body glucose control. Sub-compartment acetylproteome analyses of muscles from obese mice and humans showed remarkable overrepresentation of mitochondrial matrix proteins. These findings reveal roles for CrAT and L-carnitine in modulating the muscle acetylproteome and provide strong experimental evidence favoring the nonenzymatic carbon pressure model of mitochondrial AcK. PMID:26748706

Adhesives for Achieving Durable Bonds with Acetylated Wood

Treesearch

Charles Frihart; Rishawn Brandon; James Beecher; Rebecca Ibach

2017-01-01

Acetylation of wood imparts moisture durability, decay resistance, and dimensional stability to wood; however, making durable adhesive bonds with acetylated wood can be more difficult than with unmodified wood. The usual explanation is that the acetylated surface has fewer hydroxyl groups, resulting in a harder-to-wet surface and in fewer hydrogen bonds between wood...

Functional analysis and localisation of a delta-class glutathione S-transferase from Sarcoptes scabiei.

PubMed

Pettersson, Eva U; Ljunggren, Erland L; Morrison, David A; Mattsson, Jens G

2005-01-01

The mite Sarcoptes scabiei causes sarcoptic mange, or scabies, a disease that affects both animals and humans worldwide. Our interest in S. scabiei led us to further characterise a glutathione S-transferase. This multifunctional enzyme is a target for vaccine and drug development in several parasitic diseases. The S. scabiei glutathione S-transferase open reading frame reported here is 684 nucleotides long and yields a protein with a predicted molecular mass of 26 kDa. Through phylogenetic analysis the enzyme was classified as a delta-class glutathione S-transferase, and our paper is the first to report that delta-class glutathione S-transferases occur in organisms other than insects. The recombinant S. scabiei glutathione S-transferase was expressed in Escherichia coli via three different constructs and purified for biochemical analysis. The S. scabiei glutathione S-transferase was active towards the substrate 1-chloro-2,4-dinitrobenzene, though the positioning of fusion partners influenced the kinetic activity of the enzyme. Polyclonal antibodies raised against S. scabiei glutathione S-transferase specifically localised the enzyme to the integument of the epidermis and cavities surrounding internal organs in adult parasites. However, some minor staining of parasite intestines was observed. No staining was seen in host tissues, nor could we detect any antibody response against S. scabiei glutathione S-transferase in sera from naturally S. scabiei infected dogs or pigs. Additionally, the polyclonal sera raised against recombinant S. scabiei glutathione S-transferase readily detected a protein from mites, corresponding to the predicted size of native glutathione S-transferase.

Untangling Topic Threads in Chat-Based Communication: A Case Study

DTIC Science & Technology

2011-08-01

learning techniques such as clustering are very popular for analyzing text for topic identification (Anjewierden,, Kollöffel and Hulshof 2007; Adams...Anjewierden, A., Kollöffel, B., and Hulshof , C. (2007). Towards educational data mining: Using data mining methods for automated chat analysis to

Habitat patch size and nesting success of yellow-breasted chats

Treesearch

Dick E. Burhans; Frank R. Thompson III

1999-01-01

We measured vegetation at shrub patches used for nesting by Yellow-breasted Chats (Icteria virens) to evaluate the importance of nesting habitat patch features on nest predation, cowbird parasitism, and nest site selection. Logistic regression models indicated that nests in small patches (average diameter

Mobile Chatting Behaviour of Arts and Science College Students

ERIC Educational Resources Information Center

Ramakrishnan, N.; Priya, J. Johnsi

2016-01-01

Mobile connectivity is the order of the day. Personas irrespective of their socio-economic status possess mobile device either basic or advanced android or windows or IOS. The chat applications have become popular with younger generation. It has started trickling down to children below the age of eighteen. The behaviour has influenced the aged…

Structure-activity relationships of 4-hydroxyalkenals in the conjugation catalysed by mammalian glutathione transferases.

PubMed Central

Danielson, U H; Esterbauer, H; Mannervik, B

1987-01-01

The substrate specificities of 15 cytosolic glutathione transferases from rat, mouse and man have been explored by use of a homologous series of 4-hydroxyalkenals, extending from 4-hydroxypentenal to 4-hydroxypentadecenal. Rat glutathione transferase 8-8 is exceptionally active with the whole range of 4-hydroxyalkenals, from C5 to C15. Rat transferase 1-1, although more than 10-fold less efficient than transferase 8-8, is the second most active transferase with the longest chain length substrates. Other enzyme forms showing high activities with these substrates are rat transferase 4-4 and human transferase mu. The specificity constants, kcat./Km, for the various enzymes have been determined with the 4-hydroxyalkenals. From these constants the incremental Gibbs free energy of binding to the enzyme has been calculated for the homologous substrates. The enzymes responded differently to changes in the length of the hydrocarbon side chain and could be divided into three groups. All glutathione transferases displayed increased binding energy in response to increased hydrophobicity of the substrate. For some of the enzymes, steric limitations of the active site appear to counteract the increase in binding strength afforded by increased chain length of the substrate. Comparison of the activities with 4-hydroxyalkenals and other activated alkenes provides information about the active-site properties of certain glutathione transferases. The results show that the ensemble of glutathione transferases in a given species may serve an important physiological role in the conjugation of the whole range of 4-hydroxyalkenals. In view of its high catalytic efficiency with all the homologues, rat glutathione transferase 8-8 appears to have evolved specifically to serve in the detoxication of these reactive compounds of oxidative metabolism. PMID:3426557

Effect of acetaminophen on sulfamethazine acetylation in male volunteers.

PubMed

Tahir, I M; Iqbal, T; Saleem, S; Mehboob, H; Akhter, N; Riaz, M

2016-03-01

The effect of acetaminophen on sulfamethazine N-acetylation by human N-acetyltrasferase-2 (NAT2) was studied in 19 (n=19) healthy male volunteers in two different phases. In the first phase of the study the volunteers were given an oral dose of sulfamethazine 500 mg alone and blood and urine samples were collected. After the 10-day washout period the same selected volunteers were again administered sulfamethazine 500 mg along with 1000 mg acetaminophen. The acetylation of sulfamethazine by human NAT2 in both phases with and without acetaminophen was determined by HPLC to establish their respective phenotypes. In conclusion obtained statistics of present study revealed that acetaminophen significantly (P<0.0001) decreased sulfamethazine acetylation in plasma of both slow and fast acetylator male volunteers. A highly significant (P<0.0001) decrease in plasma-free and total sulfamethazine concentration was also observed when acetaminophen was co-administered. Urine acetylation status in both phases of the study was found not to be in complete concordance with that of plasma. Acetaminophen significantly (P<0.0001) increased the acetyl, free and total sulfamethazine concentration in urine of both slow and fast acetylators. Urine acetylation analysis has not been found to be a suitable approach for phenotypic studies. © The Author(s) 2015.

Characterizing Lysine Acetylation of Isocitrate Dehydrogenase in Escherichia coli.

PubMed

Venkat, Sumana; Chen, Hao; Stahman, Alleigh; Hudson, Denver; McGuire, Paige; Gan, Qinglei; Fan, Chenguang

2018-06-22

The Escherichia coli isocitrate dehydrogenase (ICDH) is one of the tricarboxylic acid cycle enzymes, playing key roles in energy production and carbon flux regulation. E. coli ICDH was the first bacterial enzyme shown to be regulated by reversible phosphorylation. However, the effect of lysine acetylation on E. coli ICDH, which has no sequence similarity with its counterparts in eukaryotes, is still unclear. Based on previous studies of E. coli acetylome and ICDH crystal structures, eight lysine residues were selected for mutational and kinetic analyses. They were replaced with acetyllysine by the genetic code expansion strategy or substituted with glutamine as a classic approach. Although acetylation decreased the overall ICDH activity, its effects were different site by site. Deacetylation tests demonstrated that the CobB deacetylase could deacetylate ICDH both in vivo and in vitro, but CobB was only specific for lysine residues at the protein surface. On the other hand, ICDH could be acetylated by acetyl-phosphate chemically in vitro. And in vivo acetylation tests indicated that the acetylation level of ICDH was correlated with the amounts of intracellular acetyl-phosphate. This study nicely complements previous proteomic studies to provide direct biochemical evidence for ICDH acetylation. Copyright © 2018 Elsevier Ltd. All rights reserved.

Internet Communication Disorder and the structure of the human brain: initial insights on WeChat addiction.

PubMed

Montag, Christian; Zhao, Zhiying; Sindermann, Cornelia; Xu, Lei; Fu, Meina; Li, Jialin; Zheng, Xiaoxiao; Li, Keshuang; Kendrick, Keith M; Dai, Jing; Becker, Benjamin

2018-02-01

WeChat represents one of the most popular smartphone-based applications for communication. Although the application provides several useful features that simplify daily life, a growing number of users spend excessive amounts of time on the application. This may lead to interferences with everyday life and even to addictive patterns of use. In the context of the ongoing discussion on Internet Communication Disorder (ICD), the present study aimed to better characterize the addictive potential of communication applications, using WeChat as an example, by examining associations between individual variations in tendencies towards WeChat addiction and brain structural variations in fronto-striatal-limbic brain regions. To this end levels of addictive tendencies, frequency of use and structural MRI data were assessed in n = 61 healthy participants. Higher tendencies towards WeChat addiction were associated with smaller gray matter volumes of the subgenual anterior cingulate cortex, a key region for monitoring and regulatory control in neural networks underlying addictive behaviors. Moreover, a higher frequency of the paying function was associated with smaller nucleus accumbens volumes. Findings were robust after controlling for levels of anxiety and depression. The present results are in line with previous findings in substance and behavioral addictions, and suggest a similar neurobiological basis in ICD.

Biomimetic Artificial Epigenetic Code for Targeted Acetylation of Histones.

PubMed

Taniguchi, Junichi; Feng, Yihong; Pandian, Ganesh N; Hashiya, Fumitaka; Hidaka, Takuya; Hashiya, Kaori; Park, Soyoung; Bando, Toshikazu; Ito, Shinji; Sugiyama, Hiroshi

2018-06-13

While the central role of locus-specific acetylation of histone proteins in eukaryotic gene expression is well established, the availability of designer tools to regulate acetylation at particular nucleosome sites remains limited. Here, we develop a unique strategy to introduce acetylation by constructing a bifunctional molecule designated Bi-PIP. Bi-PIP has a P300/CBP-selective bromodomain inhibitor (Bi) as a P300/CBP recruiter and a pyrrole-imidazole polyamide (PIP) as a sequence-selective DNA binder. Biochemical assays verified that Bi-PIPs recruit P300 to the nucleosomes having their target DNA sequences and extensively accelerate acetylation. Bi-PIPs also activated transcription of genes that have corresponding cognate DNA sequences inside living cells. Our results demonstrate that Bi-PIPs could act as a synthetic programmable histone code of acetylation, which emulates the bromodomain-mediated natural propagation system of histone acetylation to activate gene expression in a sequence-selective manner.

A SUMO-acetyl switch in PXR biology.

PubMed

Cui, Wenqi; Sun, Mengxi; Zhang, Shupei; Shen, Xunan; Galeva, Nadezhda; Williams, Todd D; Staudinger, Jeff L

2016-09-01

Post-translational modification (PTM) of nuclear receptor superfamily members regulates various aspects of their biology to include sub-cellular localization, the repertoire of protein-binding partners, as well as their stability and mode of degradation. The nuclear receptor pregnane X receptor (PXR, NR1I2) is a master-regulator of the drug-inducible gene expression in liver and intestine. The PXR-mediated gene activation program is primarily recognized to increase drug metabolism, drug transport, and drug efflux pathways in these tissues. The activation of PXR also has important implications in significant human diseases including inflammatory bowel disease and cancer. Our recent investigations reveal that PXR is modified by multiple PTMs to include phosphorylation, SUMOylation, and ubiquitination. Using both primary cultures of hepatocytes and cell-based assays, we show here that PXR is modified through acetylation on lysine residues. Further, we show that increased acetylation of PXR stimulates its increased SUMO-modification to support active transcriptional suppression. Pharmacologic inhibition of lysine de-acetylation using trichostatin A (TSA) alters the sub-cellular localization of PXR in cultured hepatocytes, and also has a profound impact upon PXR transactivation capacity. Both the acetylation and SUMOylation status of the PXR protein is affected by its ability to associate with the lysine de-acetylating enzyme histone de-acetylase (HDAC)3 in a complex with silencing mediator of retinoic acid and thyroid hormone receptor (SMRT). Taken together, our data support a model in which a SUMO-acetyl 'switch' occurs such that acetylation of PXR likely stimulates SUMO-modification of PXR to promote the active repression of PXR-target gene expression. This article is part of a Special Issue entitled: Xenobiotic nuclear receptors: New Tricks for An Old Dog, edited by Dr. Wen Xie. Copyright © 2016 Elsevier B.V. All rights reserved.

Autoimmune regulator is acetylated by transcription coactivator CBP/p300

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saare, Mario, E-mail: mario.saare@ut.ee; Rebane, Ana; SIAF, Swiss Institute of Allergy and Asthma Research, University of Zuerich, Davos

2012-08-15

The Autoimmune Regulator (AIRE) is a regulator of transcription in the thymic medulla, where it controls the expression of a large set of peripheral-tissue specific genes. AIRE interacts with the transcriptional coactivator and acetyltransferase CBP and synergistically cooperates with it in transcriptional activation. Here, we aimed to study a possible role of AIRE acetylation in the modulation of its activity. We found that AIRE is acetylated in tissue culture cells and this acetylation is enhanced by overexpression of CBP and the CBP paralog p300. The acetylated lysines were located within nuclear localization signal and SAND domain. AIRE with mutations thatmore » mimicked acetylated K243 and K253 in the SAND domain had reduced transactivation activity and accumulated into fewer and larger nuclear bodies, whereas mutations that mimicked the unacetylated lysines were functionally similar to wild-type AIRE. Analogously to CBP, p300 localized to AIRE-containing nuclear bodies, however, the overexpression of p300 did not enhance the transcriptional activation of AIRE-regulated genes. Further studies showed that overexpression of p300 stabilized the AIRE protein. Interestingly, gene expression profiling revealed that AIRE, with mutations mimicking K243/K253 acetylation in SAND, was able to activate gene expression, although the affected genes were different and the activation level was lower from those regulated by wild-type AIRE. Our results suggest that the AIRE acetylation can influence the selection of AIRE activated genes. -- Highlights: Black-Right-Pointing-Pointer AIRE is acetylated by the acetyltransferases p300 and CBP. Black-Right-Pointing-Pointer Acetylation occurs between CARD and SAND domains and within the SAND domain. Black-Right-Pointing-Pointer Acetylation increases the size of AIRE nuclear dots. Black-Right-Pointing-Pointer Acetylation increases AIRE protein stability. Black-Right-Pointing-Pointer AIRE acetylation mimic regulates a different set of

Mitochondrial protein acetylation as a cell-intrinsic, evolutionary driver of fat storage: chemical and metabolic logic of acetyl-lysine modifications.

PubMed

Ghanta, Sirisha; Grossmann, Ruth E; Brenner, Charles

2013-01-01

Hormone systems evolved over 500 million years of animal natural history to motivate feeding behavior and convert excess calories to fat. These systems produced vertebrates, including humans, who are famine-resistant but sensitive to obesity in environments of persistent overnutrition. We looked for cell-intrinsic metabolic features, which might have been subject to an evolutionary drive favoring lipogenesis. Mitochondrial protein acetylation appears to be such a system. Because mitochondrial acetyl-coA is the central mediator of fuel oxidation and is saturable, this metabolite is postulated to be the fundamental indicator of energy excess, which imprints a memory of nutritional imbalances by covalent modification. Fungal and invertebrate mitochondria have highly acetylated mitochondrial proteomes without an apparent mitochondrially targeted protein lysine acetyltransferase. Thus, mitochondrial acetylation is hypothesized to have evolved as a nonenzymatic phenomenon. Because the pKa of a nonperturbed Lys is 10.4 and linkage of a carbonyl carbon to an ε amino group cannot be formed with a protonated Lys, we hypothesize that acetylation occurs on residues with depressed pKa values, accounting for the propensity of acetylation to hit active sites and suggesting that regulatory Lys residues may have been under selective pressure to avoid or attract acetylation throughout animal evolution. In addition, a shortage of mitochondrial oxaloacetate under ketotic conditions can explain why macronutrient insufficiency also produces mitochondrial hyperacetylation. Reduced mitochondrial activity during times of overnutrition and undernutrition would improve fitness by virtue of resource conservation. Micronutrient insufficiency is predicted to exacerbate mitochondrial hyperacetylation. Nicotinamide riboside and Sirt3 activity are predicted to relieve mitochondrial inhibition.

Mitochondrial protein acetylation as a cell-intrinsic, evolutionary driver of fat storage: chemical and metabolic logic of acetyl-lysine modifications

PubMed Central

Ghanta, Sirisha; Grossmann, Ruth E.; Brenner, Charles

2014-01-01

Hormone systems evolved over 500 million years of animal evolution to motivate feeding behavior and convert excess calories to fat. These systems produced vertebrates, including humans, who are famine-resistant but sensitive to obesity in environments of persistent overnutrition. We looked for cell-intrinsic metabolic features, which might have been subject to an evolutionary drive favoring lipogenesis. Mitochondrial protein acetylation appears to be such a system. Because mitochondrial acetyl-coA is the central mediator of fuel oxidation and is saturable, this metabolite is postulated to be the fundamental indicator of energy excess, which imprints a memory of nutritional imbalances by covalent modification. Fungal and invertebrate mitochondria have highly acetylated mitochondrial proteomes without an apparent mitochondrially-targeted protein lysine acetyltransferase. Thus, mitochondrial acetylation is hypothesized to have evolved as a nonenzymatic phenomenon. Because the pKa of a nonperturbed Lys is 10.4 and linkage of a carbonyl carbon to an ε amino group cannot be formed with a protonated Lys, we hypothesize that acetylation occurs on residues with depressed pKa values, accounting for the propensity of acetylation to hit active sites and suggesting that regulatory Lys residues may have been under selective pressure to avoid or attract acetylation throughout animal evolution. In addition, a shortage of mitochondrial oxaloacetate under ketotic conditions can explain why macronutrient insufficiency also produces mitochondrial hyperacetylation. Reduced mitochondrial activity during times of overnutrition and undernutrition would improve fitness by virtue of resource conservation. Micronutrient insufficiency is predicted to exacerbate mitochondrial hyperacetylation. Nicotinamide riboside and Sirt3 activity are predicted to relieve mitochondrial inhibition. PMID:24050258

Acetyl-coenzyme A deacylase activity in liver is not an artifact. Subcellular distribution and substrate specificity of acetyl-coenzyme A deacylase activities in rat liver

PubMed Central

Grigat, Klaus-P.; Koppe, Klaus; Seufert, Claus-D.; Söling, Hans-D

1979-01-01

Whole liver and isolated liver mitochondria are able to release free acetate, especially under conditions of increased fatty acid oxidation. In the present paper it is shown that rat liver contains acetyl-CoA deacylase (EC 3.1.2.1) activity (0.72μmol/min per g wet wt. of liver at 30°C and 0.5mm-acetyl-CoA). At 0.5mm-acetyl-CoA 73% of total enzyme activity was found in the mitochondria, 8% in the lysosomal fraction and 19% in the postmicrosomal supernatant. Mitochondrial subfractionation shows that mitochondrial acetyl-CoA deacylase activity is restricted to the matrix space. Mitochondrial acetyl-CoA deacylase showed almost no activity with either butyryl- or hexanoyl-CoA. Acetyl-CoA hydrolase activity from purified rat liver lysosomes exhibited a very low affinity for acetyl-CoA (apparent Km>15mm compared with an apparent Km value of 0.5mm for the mitochondrial enzyme) and reacted at about the same rate with acetyl-, n-butyryl- and hexanoyl-CoA. We could not confirm the findings of Costa & Snoswell [(1975) Biochem. J. 152, 167–172] according to which mitochondrial acetyl-CoA deacylase was considered to be an artifact resulting from the combined actions of acetyl-CoA–l-carnitine acetyltransferase (EC 2.3.1.7) and acetylcarnitine hydrolase. The results are in line with the concept that free acetate released by the liver under physiological conditions stems from the intramitochondrial deacylation of acetyl-CoA. PMID:34392

Spectrofluorimetric assay method for glutathione and glutathione transferase using monobromobimane.

PubMed

Yakubu, S I; Yakasai, I A; Musa, A

2011-06-01

The primary role of glutathione transferase is to defend an organism from toxicities through catalyzing the reaction of glutathione (GSH) with potentially toxic compounds or metabolites to their chemically and biologically inert conjugates. The objective of the study was to develop a simple and sensitive spectrofluorimetric assay method for glutathione transferase using monobromobimane (MBB), a non fluorescent compound with electrophilic site. MBB slowly reacted with glutathione to form fluorescent glutathione conjugate and that the reaction was catalysed by glutathione transferase. Both non-enzymatic and enzymatic reaction products of MBB, in presence of GSH in phosphate buffer (pH 6.5), were measured by following increase of fluorescence at wavelength of 475nm. For validation of the assay method, the kinetic parameters such as the apparent Michaelis-Mente constants and maximum rates of conjugate formation as well as the specific activity of rat hepatic glutathione transferase were determined. The method was found to be sensitive, thus, applied to measure glutathione contents of crude preparation of rat hepatic cytosol fraction.

Rat lung glutathione S-transferases. Evidence for two distinct types of 22000-Mr subunits.

PubMed Central

Singh, S V; Partridge, C A; Awasthi, Y C

1984-01-01

Two immunologically distinct types of 22000-Mr subunits are present in rat lung glutathione S-transferases. One of these subunits is probably similar to Ya subunits of rat liver glutathione S-transferases, whereas the other subunit Ya' is immunologically distinct. Glutathione S-transferase II (pI7.2) of rat lung is a heterodimer (YaYa') of these subunits, and glutathione S-transferase VI (pI4.8) of rat lung is a homodimer of Ya' subunits. On hybridization in vitro of the subunits of glutathione S-transferase II of rat lung three active dimers having pI values 9.4, 7.2 and 4.8 are obtained. Immunological properties and substrate specificities indicate that the hybridized enzymes having pI7.2 and 4.8 correspond to glutathione S-transferases II and VI of rat lung respectively. Images Fig. 1. Fig. 5. PMID:6433888

Rabbit N-acetyltransferase 2 genotyping method to investigate role of acetylation polymorphism on N- and O-acetylation of aromatic and heterocyclic amine carcinogens.

PubMed

Hein, David W; Doll, Mark A

2017-09-01

The rabbit was the initial animal model to investigate the acetylation polymorphism expressed in humans. Use of the rabbit model is compromised by lack of a rapid non-invasive method for determining acetylator phenotype. Slow acetylator phenotype in the rabbit results from deletion of the N-acetyltransferase 2 (NAT2) gene. A relatively quick and non-invasive method for identifying the gene deletion was developed and acetylator phenotypes confirmed by measurement of N- and O-acetyltransferase activities in hepatic cytosols. Rabbit liver cytosols catalyzed the N-acetylation of sulfamethazine (p = 0.0014), benzidine (p = 0.0257), 4-aminobiphenyl (p = 0.0012), and the O-acetylation of N-hydroxy-2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (N-OH-PhIP; p = 0.002) at rates significantly higher in rabbits possessing NAT2 gene than rabbits with NAT2 gene deleted. In contrast, hepatic cytosols catalyzed the N-acetylation of p-aminobenzoic acid (an N-acetyltransferase 1 selective substrate) at rates that did not differ significantly (p > 0.05) between rabbits positive and negative for NAT2. The new NAT2 genotyping method facilitates use of the rabbit model to investigate the role of acetylator polymorphism in the metabolism of aromatic and heterocyclic amine drugs and carcinogens.

Optimizing Fracture Treatments in a Mississippian "Chat" Reservoir, South-Central Kansas

DOE Office of Scientific and Technical Information (OSTI.GOV)

K. David Newell; Saibal Bhattacharya; Alan Byrnes

2005-10-01

This project is a collaboration of Woolsey Petroleum Corporation (a small independent operator) and the Kansas Geological Survey. The project will investigate geologic and engineering factors critical for designing hydraulic fracture treatments in Mississippian ''chat'' reservoirs. Mississippian reservoirs, including the chat, account for 159 million m3 (1 billion barrels) of the cumulative oil produced in Kansas. Mississippian reservoirs presently represent {approx}40% of the state's 5.6*106m3 (35 million barrels) annual production. Although geographically widespread, the ''chat'' is a heterogeneous reservoir composed of chert, cherty dolomite, and argillaceous limestone. Fractured chert with micro-moldic porosity is the best reservoir in this 18- tomore » 30-m-thick (60- to 100-ft) unit. The chat will be cored in an infill well in the Medicine Lodge North field (417,638 m3 [2,626,858 bbls] oil; 217,811,000 m3 [7,692,010 mcf] gas cumulative production; discovered 1954). The core and modern wireline logs will provide geological and petrophysical data for designing a fracture treatment. Optimum hydraulic fracturing design is poorly defined in the chat, with poor correlation of treatment size to production increase. To establish new geologic and petrophysical guidelines for these treatments, data from core petrophysics, wireline logs, and oil-field maps will be input to a fracture-treatment simulation program. Parameters will be established for optimal size of the treatment and geologic characteristics of the predicted fracturing. The fracturing will be performed and subsequent wellsite tests will ascertain the results for comparison to predictions. A reservoir simulation program will then predict the rate and volumetric increase in production. Comparison of the predicted increase in production with that of reality, and the hypothetical fracturing behavior of the reservoir with that of its actual behavior, will serve as tests of the geologic and petrophysical

Past Tense Morphology in Cri Du Chat Syndrome: Experimental Evidence

ERIC Educational Resources Information Center

Wium, Kristin; Kristoffersen, Kristian Emil

2008-01-01

It has been observed that persons with Cri du chat syndrome (CDCS) have poor language production. However, very few studies have addressed the question whether all aspects of language production are equally afflicted, or whether there are differences between for instance phonological and morphological abilities. The present study was aimed at…

Cyclic AMP Inhibits the Activity and Promotes the Acetylation of Acetyl-CoA Synthetase through Competitive Binding to the ATP/AMP Pocket.

PubMed

Han, Xiaobiao; Shen, Liqiang; Wang, Qijun; Cen, Xufeng; Wang, Jin; Wu, Meng; Li, Peng; Zhao, Wei; Zhang, Yu; Zhao, Guoping

2017-01-27

The high-affinity biosynthetic pathway for converting acetate to acetyl-coenzyme A (acetyl-CoA) is catalyzed by the central metabolic enzyme acetyl-coenzyme A synthetase (Acs), which is finely regulated both at the transcriptional level via cyclic AMP (cAMP)-driven trans-activation and at the post-translational level via acetylation inhibition. In this study, we discovered that cAMP directly binds to Salmonella enterica Acs (SeAcs) and inhibits its activity in a substrate-competitive manner. In addition, cAMP binding increases SeAcs acetylation by simultaneously promoting Pat-dependent acetylation and inhibiting CobB-dependent deacetylation, resulting in enhanced SeAcs inhibition. A crystal structure study and site-directed mutagenesis analyses confirmed that cAMP binds to the ATP/AMP pocket of SeAcs, and restrains SeAcs in an open conformation. The cAMP contact residues are well conserved from prokaryotes to eukaryotes, suggesting a general regulatory mechanism of cAMP on Acs. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Polymorphisms of CHAT but not TFAM or VR22 are Associated with Alzheimer Disease Risk.

PubMed

Gao, Lili; Zhang, Yan; Deng, Jinghua; Yu, Wenbing; Yu, Yunxia

2016-06-07

BACKGROUND Alzheimer disease (AD) is a chronic neurodegenerative disease that is one of the most prevalent health problems among seniors. The cause of AD has not yet been elucidated, but many risk factors have been identified that might contribute to the pathogenesis and prognosis of AD. We conducted a meta-analysis of studies involving CHAT, TFAM, and VR22 polymorphisms and AD susceptibility to further understand the pathogenesis of AD. MATERIAL AND METHODS PubMed/Medline, Embase, Web of Science, the Cochrane Library, and Google Scholar were searched for relevant articles. Rs1880676, rs2177369, rs3810950, and rs868750 of CHAT; rs1937 and rs2306604 of TFAM; and rs10997691 and rs7070570 of VR22 are studied in this meta-analysis. RESULTS A total of 51 case-control studies with 16 446 cases and 16 057 controls were enrolled. For CHAT, rs2177369 (G>A) in whites and rs3810950 (G>A) in Asians were found to be associated with AD susceptibility. No association was detected between rs1880676 and rs868750 and AD risk. For TFAM and VR22, no significant association was detected in studied single-nucleotide polymorphisms (SNPs). CONCLUSIONS Rs2177369 and rs3810950 of CHAT are associated with AD susceptibility, but rs1880676 and rs868750 are not. Rs1937 and rs2306604 of TFAM, and rs10997691 and rs7070570 of VR22 are not significantly associated with AD risk.

Contextual Hub Analysis Tool (CHAT): A Cytoscape app for identifying contextually relevant hubs in biological networks.

PubMed

Muetze, Tanja; Goenawan, Ivan H; Wiencko, Heather L; Bernal-Llinares, Manuel; Bryan, Kenneth; Lynn, David J

2016-01-01

Highly connected nodes (hubs) in biological networks are topologically important to the structure of the network and have also been shown to be preferentially associated with a range of phenotypes of interest. The relative importance of a hub node, however, can change depending on the biological context. Here, we report a Cytoscape app, the Contextual Hub Analysis Tool (CHAT), which enables users to easily construct and visualize a network of interactions from a gene or protein list of interest, integrate contextual information, such as gene expression or mass spectrometry data, and identify hub nodes that are more highly connected to contextual nodes (e.g. genes or proteins that are differentially expressed) than expected by chance. In a case study, we use CHAT to construct a network of genes that are differentially expressed in Dengue fever, a viral infection. CHAT was used to identify and compare contextual and degree-based hubs in this network. The top 20 degree-based hubs were enriched in pathways related to the cell cycle and cancer, which is likely due to the fact that proteins involved in these processes tend to be highly connected in general. In comparison, the top 20 contextual hubs were enriched in pathways commonly observed in a viral infection including pathways related to the immune response to viral infection. This analysis shows that such contextual hubs are considerably more biologically relevant than degree-based hubs and that analyses which rely on the identification of hubs solely based on their connectivity may be biased towards nodes that are highly connected in general rather than in the specific context of interest. CHAT is available for Cytoscape 3.0+ and can be installed via the Cytoscape App Store ( http://apps.cytoscape.org/apps/chat).

Amelioration of cognitive impairment and neurodegeneration by catechin hydrate in rat model of streptozotocin-induced experimental dementia of Alzheimer's type.

PubMed

Ejaz Ahmed, Md; Khan, Mohd Moshahid; Javed, Hayate; Vaibhav, Kumar; Khan, Andleeb; Tabassum, Rizwana; Ashafaq, Mohammad; Islam, Farah; Safhi, Mohammed M; Islam, Fakhrul

2013-03-01

Alzheimer's disease (AD) is a progressive neurodegenerative disorder resulting in cognitive decline and enhancement of oxidative loads in the brain. Flavonoids have been considered to exert human health benefits by anti-oxidant and anti-inflammatory properties. The present study is aimed to elucidate the neuroprotective effect of catechin hydrate (CH), a natural flavanoid with potential antioxidant and anti-inflammatory properties, on intracerebroventricular streptozotocin (ICV-STZ) induced neuronal loss and memory impairment. To test this hypothesis, male Wistar rats were pretreated with CH (10 and 20mg/kgb wt) orally once daily for 21 days and then bilaterally injected with ICV-STZ (3mg/kgb wt), while sham group rats receive the same volume of vehicle. After 2 weeks of ICV-STZ infusion, rats were tested for cognitive performance using Morris water maze (MWM) test and then sacrifice for biochemical and histopathological assays. CH was found to be successful in upregulating the antioxidant status and prevented the memory loss. The expression of choline acetyl transferase (ChAT) was decreased in ICV-STZ group and CH pretreatment increases the expression of ChAT. Moreover, inflammatory mediators like TNF-α, IL-1β levels and expression of iNOS were significantly attenuated by CH pretreatment. The study suggests that CH is effective in preventing memory loss, ameliorating the oxidative stress and might be beneficial for the treatment of sporadic dementia of Alzheimer's type (SDAT). Copyright © 2013 Elsevier Ltd. All rights reserved.

Pilot Susan L. Still chats with white room closeout crew member

NASA Technical Reports Server (NTRS)

1997-01-01

KENNEDY SPACE CENTER, FLA. -- STS-83 Pilot Susan L. Still chats with white room closeout crew member Rene Arriens as she prepares to enter the Space Shuttle Columbia at Launch Pad 39A with assistance from closeout crew worker Bob Saulnier (behind Still).

Synthesis of polyrotaxanes from acetyl-β-cyclodextrin

NASA Astrophysics Data System (ADS)

Ristić, I. S.; Nikolić, L.; Nikolić, V.; Ilić, D.; Budinski-Simendić, J.

2011-12-01

Polyrotaxanes are intermediary products in the synthesis of topological gels. They are created by inclusion complex formation of hydrophobic linear macromolecules with cyclodextrins or their derivatives. Then, pairs of cyclodextrin molecules with covalently linkage were practically forming the nodes of the semi-flexible polymer network. Such gels are called topological gels and they can absorb huge quantities of water due to the net flexibility allowing the poly(ethylene oxide) chains to slide through the cyclodextrin cavities, without being pulled out altogether. For polyrotaxane formation poly(ethylene oxide) was used like linear macromolecules. There are hydroxyl groups at poly(ethylene oxide) chains, whereby the linking of the voluminous molecules should be made. To avoid the reaction of cyclodextrin OH groups with stoppers, they should be protected by, e.g., acetylation. In this work, the acetylation of the OH groups of β-cyclodextrin was performed by acetic acid anhydride with iodine as the catalyst. The acetylation reaction was assessed by the FTIR and HPLC method. By the HPLC analysis was found that the acetylation was completed in 20 minutes. Inserting of poly(ethylene oxide) with 4000 g/mol molecule mass into acetyl-β-cyclodextrin with 2:1 poly(ethylene oxide) monomer unit to acetyl-β-cyclodextrin ratio was also monitored by FTIR, and it was found that the process was completed in 12 h at the temperature of 10°C. If the process is performed at temperatures above 10°C, or for periods longer than 12 hours, the process of uncontrolled hydrolysis of acetate groups was initiated.

Distribution of the P2X2 receptor and chemical coding in ileal enteric neurons of obese male mice (ob/ob)

PubMed Central

Mizuno, Márcia Sanae; Crisma, Amanda Rabello; Borelli, Primavera; Schäfer, Bárbara Tavares; Silveira, Mariana Póvoa; Castelucci, Patricia

2014-01-01

AIM: To investigate the colocalization, density and profile of neuronal areas of enteric neurons in the ileum of male obese mice. METHODS: The small intestinal samples of male mice in an obese group (OG) (C57BL/6J ob/ob) and a control group (CG) (+/+) were used. The tissues were analyzed using a double immunostaining technique for immunoreactivity (ir) of the P2X2 receptor, nitric oxide synthase (NOS), choline acetyl transferase (ChAT) and calretinin (Calr). Also, we investigated the density and profile of neuronal areas of the NOS-, ChAT- and Calr-ir neurons in the myenteric plexus. Myenteric neurons were labeled using an NADH-diaphorase histochemical staining method. RESULTS: The analysis demonstrated that the P2X2 receptor was expressed in the cytoplasm and in the nuclear and cytoplasmic membranes only in the CG. Neuronal density values (neuron/cm2) decreased 31% (CG: 6579 ± 837; OG: 4556 ± 407) and 16.5% (CG: 7796 ± 528; OG: 6513 ± 610) in the NOS-ir and calretinin-ir neurons in the OG, respectively (P < 0.05). Density of ChAT-ir (CG: 6200 ± 310; OG: 8125 ± 749) neurons significantly increased 31% in the OG (P < 0.05). Neuron size studies demonstrated that NOS, ChAT, and Calr-ir neurons did not differ significantly between the CG and OG groups. The examination of NADH-diaphorase-positive myenteric neurons revealed an overall similarity between the OG and CG. CONCLUSION: Obesity may exert its effects by promoting a decrease in P2X2 receptor expression and modifications in the density of the NOS-ir, ChAT-ir and CalR-ir myenteric neurons. PMID:25320527

Structure, morphology and functionality of acetylated and oxidised barley starches.

PubMed

El Halal, Shanise Lisie Mello; Colussi, Rosana; Pinto, Vânia Zanella; Bartz, Josiane; Radunz, Marjana; Carreño, Neftali Lenin Villarreal; Dias, Alvaro Renato Guerra; Zavareze, Elessandra da Rosa

2015-02-01

Acetylation and oxidation are chemical modifications which alter the properties of starch. The degree of modification of acetylated and oxidized starches is dependent on the catalyst and active chlorine concentrations, respectively. The objective of this study was to evaluate the effect of acetylation and oxidation on the structural, morphological, physical-chemical, thermal and pasting properties of barley starch. Barley starches were acetylated at different catalyst levels (11%, 17%, and 23% of NaOH solution) and oxidized at different sodium hypochlorite concentrations (1.0%, 1.5%, and 2.0% of active chlorine). Fourier-transformed infrared spectroscopy (FTIR), X-ray diffractograms, thermal, morphological, and pasting properties, swelling power and solubility of starches were evaluated. The degree of substitution (DS) of the acetylated starches increased with the rise in catalyst concentration. The percentage of carbonyl (CO) and carboxyl (COOH) groups in oxidized starches also increased with the rise of active chlorine level. The presence of hydrophobic acetyl groups, carbonyl and carboxyl groups caused a partial disorganization and depolymerization of starch granules. The structural, morphological and functional changes in acetylated and oxidized starches varied according to reaction conditions. Acetylation makes barley starch more hydrophobic by the insertion of acetyl groups. Also the oxidation promotes low retrogradation and viscosity. All these characteristics are important for biodegradable film production. Copyright © 2014 Elsevier Ltd. All rights reserved.

Lysine Acetylation of CREBH Regulates Fasting-Induced Hepatic Lipid Metabolism

PubMed Central

Kim, Hyunbae; Mendez, Roberto; Chen, Xuequn; Fang, Deyu

2015-01-01

Cyclic AMP-responsive element-binding protein 3-like 3, hepatocyte specific (CREBH), is a hepatic transcription factor that functions as a key regulator of energy homeostasis. Here, we defined a regulatory CREBH posttranslational modification process, namely, lysine-specific acetylation, and its functional involvement in fasting-induced hepatic lipid metabolism. Fasting induces CREBH acetylation in mouse livers in a time-dependent manner, and this event is critical for CREBH transcriptional activity in regulating hepatic lipid homeostasis. The histone acetyltransferase PCAF-mediated acetylation and the deacetylase sirtuin-1-mediated deacetylation coexist to maintain CREBH acetylation states under fasting conditions. Site-directed mutagenesis and functional analyses revealed that the lysine (K) residue at position 294 (K294) within the bZIP domain of the CREBH protein is the site where fasting-induced acetylation/deacetylation occurs. Introduction of the acetylation-deficient (K294R) or acetylation-mimicking (K294Q) mutation inhibited or enhanced CREBH transcriptional activity, respectively. Importantly, CREBH acetylation at lysine 294 was required for the interaction and synergy between CREBH and peroxisome proliferator-activated receptor α (PPARα) in activating their target genes upon fasting or glucagon stimulation. Introduction of the CREBH lysine 294 mutation in the liver leads to hepatic steatosis and hyperlipidemia in animals under prolonged fasting. In summary, our study reveals a molecular mechanism by which fasting or glucagon stimulation modulates lipid homeostasis through acetylation of CREBH. PMID:26438600

Constructing Sexuality and Identity in an Online Teen Chat Room

ERIC Educational Resources Information Center

Subrahmanyam, K.; Greenfield, P. M.; Tynes, B.

2004-01-01

In this article, we propose that adolescents' online interactions are both a literal and a metaphoric screen for representing major adolescent developmental issues, such as sexuality and identity. Because of the public nature of Internet chat rooms, they provide an open window into the expression of adolescent concerns. Our study utilizes this…

Online Chats: A Strategy to Enhance Learning in Large Classes

ERIC Educational Resources Information Center

Mtshali, Muntuwenkosi Abraham; Maistry, Suriamurthee Moonsamy; Govender, Desmond Wesley

2015-01-01

Online-supported teaching and learning is a technological innovation in education that integrates face-to-face teaching in plenary lectures, with an online component using a learning management system. This extends opportunities to students to interact with one another via online chats in the process of transacting their learning. There is a need…

Metaphors of Synchrony: Emergence and Differentiation of Online Chat Devices

ERIC Educational Resources Information Center

Latzko-Toth, Guillaume

2010-01-01

Through a detailed account of the history of online chat devices, this article shows the emergence, over time, of two distinct interactional formats underlying these social media. They may be captured by two generic metaphors of synchrony: "conference" (a gathering in a virtual place where unfocused interactions and group sociability occur) and…

Acetyl coenzyme A synthetase is acetylated on multiple lysine residues by a protein acetyltransferase with a single Gcn5-type N-acetyltransferase (GNAT) domain in Saccharopolyspora erythraea.

PubMed

You, Di; Yao, Li-Li; Huang, Dan; Escalante-Semerena, Jorge C; Ye, Bang-Ce

2014-09-01

Reversible lysine acetylation (RLA) is used by cells of all domains of life to modulate protein function. To date, bacterial acetylation/deacetylation systems have been studied in a few bacteria (e.g., Salmonella enterica, Bacillus subtilis, Escherichia coli, Erwinia amylovora, Mycobacterium tuberculosis, and Geobacillus kaustophilus), but little is known about RLA in antibiotic-producing actinomycetes. Here, we identify the Gcn5-like protein acetyltransferase AcuA of Saccharopolyspora erythraea (SacAcuA, SACE_5148) as the enzyme responsible for the acetylation of the AMP-forming acetyl coenzyme A synthetase (SacAcsA, SACE_2375). Acetylated SacAcsA was deacetylated by a sirtuin-type NAD(+)-dependent consuming deacetylase (SacSrtN, SACE_3798). In vitro acetylation/deacetylation of SacAcsA enzyme was studied by Western blotting, and acetylation of lysine residues Lys(237), Lys(380), Lys(611), and Lys(628) was confirmed by mass spectrometry. In a strain devoid of SacAcuA, none of the above-mentioned Lys residues of SacAcsA was acetylated. To our knowledge, the ability of SacAcuA to acetylate multiple Lys residues is unique among AcuA-type acetyltransferases. Results from site-specific mutagenesis experiments showed that the activity of SacAcsA was controlled by lysine acetylation. Lastly, immunoprecipitation data showed that in vivo acetylation of SacAcsA was influenced by glucose and acetate availability. These results suggested that reversible acetylation may also be a conserved regulatory posttranslational modification strategy in antibiotic-producing actinomycetes. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

4-Aminobiphenyl Downregulation of NAT2 Acetylator Genotype–Dependent N- and O-acetylation of Aromatic and Heterocyclic Amine Carcinogens in Primary Mammary Epithelial Cell Cultures from Rapid and Slow Acetylator Rats

PubMed Central

Jefferson, Felicia A.; Xiao, Gong H.; Hein, David W.

2009-01-01

Aromatic and heterocyclic amine carcinogens present in the diet and in cigarette smoke induce breast tumors in rats. N-acetyltransferase 1 (NAT1) and N-acetyltransferase 2 (NAT2) enzymes have important roles in their metabolic activation and deactivation. Human epidemiological studies suggest that genetic polymorphisms in NAT1 and/or NAT2 modify breast cancer risk in women exposed to these carcinogens. p-Aminobenzoic acid (selective for rat NAT2) and sulfamethazine (SMZ; selective for rat NAT1) N-acetyltransferase catalytic activities were both expressed in primary cultures of rat mammary epithelial cells. PABA, 2-aminofluorene, and 4-aminobiphenyl N-acetyltransferase and N-hydroxy-2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine and N-hydroxy-2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline O-acetyltransferase activities were two- to threefold higher in mammary epithelial cell cultures from rapid than slow acetylator rats. In contrast, SMZ (a rat NAT1-selective substrate) N-acetyltransferase activity did not differ between rapid and slow acetylators. Rat mammary cells cultured in the medium supplemented 24 h with 10μM ABP showed downregulation in the N-and O-acetylation of all substrates tested except for the NAT1-selective substrate SMZ. This downregulation was comparable in rapid and slow NAT2 acetylators. These studies clearly show NAT2 acetylator genotype–dependent N- and O-acetylation of aromatic and heterocyclic amine carcinogens in rat mammary epithelial cell cultures to be subject to downregulation by the arylamine carcinogen ABP. PMID:18842621

Histone deacetylase 3 indirectly modulates tubulin acetylation

PubMed Central

Bacon, Travis; Seiler, Caroline; Wolny, Marcin; Hughes, Ruth; Watson, Peter; Schwabe, John; Grigg, Ronald; Peckham, Michelle

2015-01-01

Histone deacetylase 3 (HDAC3), a member of the Class I subfamily of HDACs, is found in both the nucleus and the cytoplasm. Its roles in the nucleus have been well characterized, but its cytoplasmic roles are still not elucidated fully. We found that blocking HDAC3 activity using MI192, a compound specific for HDAC3, modulated tubulin acetylation in the human prostate cancer cell line PC3. A brief 1 h treatment of PC3 cells with MI192 significantly increased levels of tubulin acetylation and ablated the dynamic behaviour of microtubules in live cells. siRNA-mediated knockdown (KD) of HDAC3 in PC3 cells, significantly increased levels of tubulin acetylation, and overexpression reduced it. However, the active HDAC3–silencing mediator of retinoic and thyroid receptors (SMRT)–deacetylase-activating domain (DAD) complex did not directly deacetylate tubulin in vitro. These data suggest that HDAC3 indirectly modulates tubulin acetylation. PMID:26450925

Histone deacetylase 3 indirectly modulates tubulin acetylation.

PubMed

Bacon, Travis; Seiler, Caroline; Wolny, Marcin; Hughes, Ruth; Watson, Peter; Schwabe, John; Grigg, Ronald; Peckham, Michelle

2015-12-15

Histone deacetylase 3 (HDAC3), a member of the Class I subfamily of HDACs, is found in both the nucleus and the cytoplasm. Its roles in the nucleus have been well characterized, but its cytoplasmic roles are still not elucidated fully. We found that blocking HDAC3 activity using MI192, a compound specific for HDAC3, modulated tubulin acetylation in the human prostate cancer cell line PC3. A brief 1 h treatment of PC3 cells with MI192 significantly increased levels of tubulin acetylation and ablated the dynamic behaviour of microtubules in live cells. siRNA-mediated knockdown (KD) of HDAC3 in PC3 cells, significantly increased levels of tubulin acetylation, and overexpression reduced it. However, the active HDAC3-silencing mediator of retinoic and thyroid receptors (SMRT)-deacetylase-activating domain (DAD) complex did not directly deacetylate tubulin in vitro. These data suggest that HDAC3 indirectly modulates tubulin acetylation. © 2015 Authors.

Baby FaceTime: Can Toddlers Learn from Online Video Chat?

ERIC Educational Resources Information Center

Myers, Lauren J.; LeWitt, Rachel B.; Gallo, Renee E.; Maselli, Nicole M.

2017-01-01

There is abundant evidence for the "video deficit": children under 2 years old learn better in person than from video. We evaluated whether these findings applied to video chat by testing whether children aged 12-25 months could form relationships with and learn from on-screen partners. We manipulated social contingency: children…

Mobile-Based Chatting for Meaning Negotiation in Foreign Language Learning

ERIC Educational Resources Information Center

Castrillo, María Dolores; Martín-Monje, Elena; Bárcena, Elena

2014-01-01

This paper analyzes the adequacy of mobile chatting via Whatsapp for the enhancement of a type of spontaneous and colloquial written interaction which has a strong connection with oral discourse. This is part of a research project undertaken with Spanish students of German as a foreign language with a beginner's or quasi-beginner's level. The…

Molecular and biochemical characterization of tomato farnesyl-protein transferase.

PubMed

Schmitt, D; Callan, K; Gruissem, W

1996-10-01

The prenylation of membrane-associated proteins involved in the regulation of eukaryotic cell growth and signal transduction is critically important for their subcellular localization and biological activity. In contrast to mammalian cells and yeast, however, the function of protein prenylation in plants is not well understood and only a few prenylated proteins have been identified. We partially purified and characterized farnesyl-protein transferase from tomato (Lycopersicon esculentum, LeFTase) to analyze its biochemical and molecular properties. Using Ras- and G gamma-specific peptide substrates and competition assays we showed that tomato protein extracts have both farnesyl-protein transferase and geranylgeranyl-protein transferase 1 activities. Compared with the heterologous synthetic peptide substrates, the plant-specific CaaX sequence of the ANJ1 protein is a less efficient substrate for LeFTase in vitro. LeFTase activity profiles and LeFTase beta-subunit protein (LeFTB) levels differ significantly in various tissues and are regulated during fruit development. Partially purified LeFTase requires Zn2+ and Mg2+ for enzymatic activity and has an apparent molecular mass of 100 kD Immunoprecipitation experiments using anti-alpha LeFTB antibodies confirmed that LeFTB is a component of LeFTase but not of tomato geranylgeranyl-protein transferase 1. Based on their conserved bio-chemical activities, we expect that prenyltransferases are likely integrated with the sterol biosynthesis pathway in the control of plant cell growth.

Variable Omission of "ne" in Real-Time French Chat: A Corpus-Driven Comparison of Educational and Non-Educational Contexts

ERIC Educational Resources Information Center

van Compernolle, Remi A.; Williams, Lawrence

2009-01-01

This article reports on the variable omission of the French negative particle "ne" (the first marker of verbal negation) in synchronous (i.e., real-time) electronic communication environments. Patterns of variation in a corpus of non-educational chat (i.e., free, public-access Internet chat) are analyzed and compared to data produced by first-,…

Substance P and acetylcholine are co-localized in the pathway mediating mucociliary activity in Rana pipiens.

PubMed

Hernández, C J; Ortíz, T; Rosa, C; Foster, K; Tyagi, M; Lugo, N; Albrecht, R; Chinapen, S

2007-04-01

Mucociliary activity is an important clearance mechanism in the respiratory system of air breathing vertebrates. Substance P (SP) and acetylcholine play a key role in the stimulation of the mucociliary transport in the frog palate. In this study, retrograde neuronal tracing was combined with immunocytochemistry for SP and choline acetyl transferase (ChAT) in the trigeminal ganglion and for neurokinin-1 receptor (NK1R) in the palate of Rana pipiens. The cells of origin of the palatine nerve were identified in the trigeminal ganglion using the retrograde tracer Fluorogold (FG). Optimal labeling of FG cells in the trigeminal ganglion was obtained at 96 h of exposure. Immunoflorescent shows that SP and acetylcholine are co-localized in 92% of the cells labeled with FG in the trigeminal ganglion. NK1 receptors were found in the membrane of epithelial and goblet cells of the palate. Ultrastructural study of the palate showed axonal-like endings with vesicles in connection with epithelial and goblet cells. These results further support the concerted action of both neurotransmitters in the regulation of mucociliary activity in the frog palate.

Ubiquitin acetylation inhibits polyubiquitin chain elongation

PubMed Central

Ohtake, Fumiaki; Saeki, Yasushi; Sakamoto, Kensaku; Ohtake, Kazumasa; Nishikawa, Hiroyuki; Tsuchiya, Hikaru; Ohta, Tomohiko; Tanaka, Keiji; Kanno, Jun

2015-01-01

Ubiquitylation is a versatile post-translational modification (PTM). The diversity of ubiquitylation topologies, which encompasses different chain lengths and linkages, underlies its widespread cellular roles. Here, we show that endogenous ubiquitin is acetylated at lysine (K)-6 (AcK6) or K48. Acetylated ubiquitin does not affect substrate monoubiquitylation, but inhibits K11-, K48-, and K63-linked polyubiquitin chain elongation by several E2 enzymes in vitro. In cells, AcK6-mimetic ubiquitin stabilizes the monoubiquitylation of histone H2B—which we identify as an endogenous substrate of acetylated ubiquitin—and of artificial ubiquitin fusion degradation substrates. These results characterize a mechanism whereby ubiquitin, itself a PTM, is subject to another PTM to modulate mono- and polyubiquitylation, thus adding a new regulatory layer to ubiquitin biology. PMID:25527407

Baby FaceTime: can toddlers learn from online video chat?

PubMed

Myers, Lauren J; LeWitt, Rachel B; Gallo, Renee E; Maselli, Nicole M

2017-07-01

There is abundant evidence for the 'video deficit': children under 2 years old learn better in person than from video. We evaluated whether these findings applied to video chat by testing whether children aged 12-25 months could form relationships with and learn from on-screen partners. We manipulated social contingency: children experienced either real-time FaceTime conversations or pre-recorded Videos as the partner taught novel words, actions and patterns. Children were attentive and responsive in both conditions, but only children in the FaceTime group responded to the partner in a temporally synced manner. After one week, children in the FaceTime condition (but not the Video condition) preferred and recognized their Partner, learned more novel patterns, and the oldest children learned more novel words. Results extend previous studies to demonstrate that children under 2 years show social and cognitive learning from video chat because it retains social contingency. A video abstract of this article can be viewed at: https://youtu.be/rTXaAYd5adA. © 2016 John Wiley & Sons Ltd.

CPLA 1.0: an integrated database of protein lysine acetylation.

PubMed

Liu, Zexian; Cao, Jun; Gao, Xinjiao; Zhou, Yanhong; Wen, Longping; Yang, Xiangjiao; Yao, Xuebiao; Ren, Jian; Xue, Yu

2011-01-01

As a reversible post-translational modification (PTM) discovered decades ago, protein lysine acetylation was known for its regulation of transcription through the modification of histones. Recent studies discovered that lysine acetylation targets broad substrates and especially plays an essential role in cellular metabolic regulation. Although acetylation is comparable with other major PTMs such as phosphorylation, an integrated resource still remains to be developed. In this work, we presented the compendium of protein lysine acetylation (CPLA) database for lysine acetylated substrates with their sites. From the scientific literature, we manually collected 7151 experimentally identified acetylation sites in 3311 targets. We statistically studied the regulatory roles of lysine acetylation by analyzing the Gene Ontology (GO) and InterPro annotations. Combined with protein-protein interaction information, we systematically discovered a potential human lysine acetylation network (HLAN) among histone acetyltransferases (HATs), substrates and histone deacetylases (HDACs). In particular, there are 1862 triplet relationships of HAT-substrate-HDAC retrieved from the HLAN, at least 13 of which were previously experimentally verified. The online services of CPLA database was implemented in PHP + MySQL + JavaScript, while the local packages were developed in JAVA 1.5 (J2SE 5.0). The CPLA database is freely available for all users at: http://cpla.biocuckoo.org.

CPLA 1.0: an integrated database of protein lysine acetylation

PubMed Central

Liu, Zexian; Cao, Jun; Gao, Xinjiao; Zhou, Yanhong; Wen, Longping; Yang, Xiangjiao; Yao, Xuebiao; Ren, Jian; Xue, Yu

2011-01-01

As a reversible post-translational modification (PTM) discovered decades ago, protein lysine acetylation was known for its regulation of transcription through the modification of histones. Recent studies discovered that lysine acetylation targets broad substrates and especially plays an essential role in cellular metabolic regulation. Although acetylation is comparable with other major PTMs such as phosphorylation, an integrated resource still remains to be developed. In this work, we presented the compendium of protein lysine acetylation (CPLA) database for lysine acetylated substrates with their sites. From the scientific literature, we manually collected 7151 experimentally identified acetylation sites in 3311 targets. We statistically studied the regulatory roles of lysine acetylation by analyzing the Gene Ontology (GO) and InterPro annotations. Combined with protein–protein interaction information, we systematically discovered a potential human lysine acetylation network (HLAN) among histone acetyltransferases (HATs), substrates and histone deacetylases (HDACs). In particular, there are 1862 triplet relationships of HAT-substrate-HDAC retrieved from the HLAN, at least 13 of which were previously experimentally verified. The online services of CPLA database was implemented in PHP + MySQL + JavaScript, while the local packages were developed in JAVA 1.5 (J2SE 5.0). The CPLA database is freely available for all users at: http://cpla.biocuckoo.org. PMID:21059677

Combinatorial Histone Acetylation Patterns Are Generated by Motif-Specific Reactions.

PubMed

Blasi, Thomas; Feller, Christian; Feigelman, Justin; Hasenauer, Jan; Imhof, Axel; Theis, Fabian J; Becker, Peter B; Marr, Carsten

2016-01-27

Post-translational modifications (PTMs) are pivotal to cellular information processing, but how combinatorial PTM patterns ("motifs") are set remains elusive. We develop a computational framework, which we provide as open source code, to investigate the design principles generating the combinatorial acetylation patterns on histone H4 in Drosophila melanogaster. We find that models assuming purely unspecific or lysine site-specific acetylation rates were insufficient to explain the experimentally determined motif abundances. Rather, these abundances were best described by an ensemble of models with acetylation rates that were specific to motifs. The model ensemble converged upon four acetylation pathways; we validated three of these using independent data from a systematic enzyme depletion study. Our findings suggest that histone acetylation patterns originate through specific pathways involving motif-specific acetylation activity. Copyright © 2016 Elsevier Inc. All rights reserved.

Identification and analysis of o-acetylated sialoglycoproteins.

PubMed

Mandal, Chandan; Mandal, Chitra

2013-01-01

5-N-acetylneuraminic acid, commonly known as sialic acid (Sia), constitutes a family of N- and O-substituted 9-carbon monosaccharides. Frequent modification of O-acetylations at positions C-7, C-8, or C-9 of Sias generates a family of O-acetylated sialic acid (O-AcSia) and plays crucial roles in many cellular events like cell-cell adhesion, proliferation, migration, etc. Therefore, identification and analysis of O-acetylated sialoglycoproteins (O-AcSGPs) are important. In this chapter, we describe several approaches for successful identification of O-AcSGPs. We broadly divide them into two categories, i.e., invasive and noninvasive methods. Several O-AcSias-binding probes are used for this purpose. Detailed methodologies for step-by-step identification using these probes have been discussed. We have also included a few invasive analytical methods for identification and quantitation of O-AcSias. Several indirect methods are also elaborated for such purpose, in which O-acetyl group from sialic acids is initially removed followed by detection of Sias by several approaches. For molecular identification, we have described methods for affinity purification of O-AcSGPs using an O-AcSias-binding lectin as an affinity matrix followed by sequencing using matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF-TOF) mass spectroscopy (MS). In spite of special attention, loss of O-acetyl groups due to its sensitivity towards alkaline pH and high temperature along with migration of labile O-acetyl groups from C7-C8-C9 during sample preparation is difficult to avoid. Therefore there is always a risk for underestimation of O-AcSias.

Structure of human O-GlcNAc transferase and its complex with a peptide substrate

PubMed Central

Lazarus, Michael B.; Nam, Yunsun; Jiang, Jiaoyang; Sliz, Piotr; Walker, Suzanne

2010-01-01

O-GlcNAc transferase (OGT) is an essential mammalian enzyme that couples metabolic status to the regulation of a wide variety of cellular signaling pathways by acting as a nutrient sensor1. OGT catalyzes the transfer of N-acetyl-glucosamine from UDP-GlcNAc to serines and threonines of cytoplasmic, nuclear and mitochondrial proteins2,3, including numerous transcription factors4, tumor suppressors, kinases5, phosphatases1, and histone-modifying proteins6. Aberrant O-GlcNAcylation by OGT has been linked to insulin resistance7, diabetic complications8, cancer9 and neurodegenerative diseases including Alzheimer’s10. Despite the importance of OGT, the details of how it recognizes and glycosylates its protein substrates are largely unknown. We report here two crystal structures of human OGT, as a binary complex with UDP (2.8 A) and a ternary complex with UDP and a peptide substrate (1.95 A). The structures provide clues to the enzyme mechanism, show how OGT recognizes target peptide sequences, and reveal the fold of the unique domain between the two halves of the catalytic region. This information will accelerate the rational design of biological experiments to investigate OGT’s functions and the design of inhibitors for use as cellular probes and to assess its potential as a therapeutic target. PMID:21240259

Bringing Japan and Taiwan Closer Electronically: A Look at an Intercultural Online Synchronic Chat Task and Its Effect on Motivation

ERIC Educational Resources Information Center

Freiermuth, Mark R.; Huang, Hsin-chou

2012-01-01

This study examines the motivation of 20 Japanese students of English as a foreign language (EFL) who chatted electronically with 19 Taiwanese EFL students using online synchronous chat software. In particular, we were interested in four factors that affect task-based motivation: the willingness to communicate, task attractiveness, task…

Accuracy of "Modified Checklist for Autism in Toddlers" ("M-CHAT") in Detecting Autism and Other Developmental Disorders in Community Clinics

ERIC Educational Resources Information Center

Toh, Teck-Hock; Tan, Vivian Wee-Yen; Lau, Peter Sie-Teck; Kiyu, Andrew

2018-01-01

This study determined the accuracy of "Modified Checklist for Autism in Toddlers" ("M-CHAT") in detecting toddlers with autism spectrum disorder (ASD) and other developmental disorders (DD) in community mother and child health clinics. We analysed 19,297 eligible toddlers (15-36 months) who had "M-CHAT" performed in…

Collaborative Learning through Chat Discussions and Argument Diagrams in Secondary School

ERIC Educational Resources Information Center

Marttunen, Miika; Laurinen, Leena

2007-01-01

This study clarifies whether secondary school students develop their argumentation skills through reading and collaboration. The students first constructed an individual argument diagram on genetically modified organisms, read three articles, and improved their diagrams. Next, they engaged in a chat debate, reflected on their debate by…

Interactions between Text Chat and Audio Modalities for L2 Communication and Feedback in the Synthetic World "Second Life"

ERIC Educational Resources Information Center

Wigham, Ciara R.; Chanier, Thierry

2015-01-01

This paper reports on a study of the interactions between text chat and audio modalities in L2 communication in a synthetic (virtual) world and observes whether the text chat modality was used for corrective feedback and the characteristics of the latter. This is examined within the context of a hybrid content and language integrated learning…

Erasers of Histone Acetylation: The Histone Deacetylase Enzymes

PubMed Central

Seto, Edward; Yoshida, Minoru

2014-01-01

Histone deacetylases (HDACs) are enzymes that catalyze the removal of acetyl functional groups from the lysine residues of both histone and nonhistone proteins. In humans, there are 18 HDAC enzymes that use either zinc- or NAD+-dependent mechanisms to deacetylate acetyl lysine substrates. Although removal of histone acetyl epigenetic modification by HDACs regulates chromatin structure and transcription, deacetylation of nonhistones controls diverse cellular processes. HDAC inhibitors are already known potential anticancer agents and show promise for the treatment of many diseases. PMID:24691964

Internet Relay Chat: a window of opportunity for healthcare quality.

PubMed

Harris, C S

1998-01-01

Internet Relay Chat (IRC) program is a medium that can provide low-cost interactive conferencing for healthcare organizations. This article analyzes IRC in the context of the many facets of the Internet, discusses some precautions regarding IRC use, and lists some sources of help for the user. IRC is an extremely powerful adjunct to other Internet programs.

The Metabolic Fate of Deoxynivalenol and Its Acetylated Derivatives in a Wheat Suspension Culture: Identification and Detection of DON-15-O-Glucoside, 15-Acetyl-DON-3-O-Glucoside and 15-Acetyl-DON-3-Sulfate

PubMed Central

Schmeitzl, Clemens; Warth, Benedikt; Fruhmann, Philipp; Michlmayr, Herbert; Malachová, Alexandra; Berthiller, Franz; Schuhmacher, Rainer; Krska, Rudolf; Adam, Gerhard

2015-01-01

Deoxynivalenol (DON) is a protein synthesis inhibitor produced by the Fusarium species, which frequently contaminates grains used for human or animal consumption. We treated a wheat suspension culture with DON or one of its acetylated derivatives, 3-acetyl-DON (3-ADON), 15-acetyl-DON (15-ADON) and 3,15-diacetyl-DON (3,15-diADON), and monitored the metabolization over a course of 96 h. Supernatant and cell extract samples were analyzed using a tailored LC-MS/MS method for the quantification of DON metabolites. We report the formation of tentatively identified DON-15-O-β-D-glucoside (D15G) and of 15-acetyl-DON-3-sulfate (15-ADON3S) as novel deoxynivalenol metabolites in wheat. Furthermore, we found that the recently identified 15-acetyl-DON-3-O-β-D-glucoside (15-ADON3G) is the major metabolite produced after 15-ADON challenge. 3-ADON treatment led to a higher intracellular content of toxic metabolites after six hours compared to all other treatments. 3-ADON was exclusively metabolized into DON before phase II reactions occurred. In contrast, we found that 15-ADON was directly converted into 15-ADON3G and 15-ADON3S in addition to metabolization into deoxynivalenol-3-O-β-D-glucoside (D3G). This study highlights significant differences in the metabolization of DON and its acetylated derivatives. PMID:26274975

N-Acetyl-4-aminophenol (paracetamol), N-acetyl-2-aminophenol and acetanilide in urine samples from the general population, individuals exposed to aniline and paracetamol users.

PubMed

Dierkes, Georg; Weiss, Tobias; Modick, Hendrik; Käfferlein, Heiko Udo; Brüning, Thomas; Koch, Holger M

2014-01-01

Epidemiological studies suggest associations between the use of N-acetyl-4-aminophenol (paracetamol) during pregnancy and increased risks of reproductive disorders in the male offspring. Previously we have reported a ubiquitous urinary excretion of N-acetyl-4-aminophenol in the general population. Possible sources are (1) direct intake of paracetamol through medication, (2) paracetamol residues in the food chain and (3) environmental exposure to aniline or related substances that are metabolized into N-acetyl-4-aminophenol. In order to elucidate the origins of the excretion of N-acetyl-4-aminophenol in urine and to contribute to the understanding of paracetamol and aniline metabolism in humans we developed a rapid, turbulent-flow HPLC-MS/MS method with isotope dilution for the simultaneous quantification of N-acetyl-4-aminophenol and two other aniline related metabolites, N-acetyl-2-aminophenol and acetanilide. We applied this method to three sets of urine samples: (1) individuals with no known exposure to aniline and also no recent paracetamol medication; (2) individuals after occupational exposure to aniline but no paracetamol medication and (3) paracetamol users. We confirmed the omnipresent excretion of N-acetyl-4-aminophenol. Additionally we revealed an omnipresent excretion of N-acetyl-2-aminophenol. In contrast, acetanilide was only found after occupational exposure to aniline, not in the general population or after paracetamol use. The results lead to four preliminary conclusions: (1) other sources than aniline seem to be responsible for the major part of urinary N-acetyl-4-aminophenol in the general population; (2) acetanilide is a metabolite of aniline in man and a valuable biomarker for aniline in occupational settings; (3) aniline baseline levels in the general population measured after chemical hydrolysis do not seem to originate from acetanilide and hence not from a direct exposure to aniline itself and (4) N-acetyl-2-aminophenol does not seem to be

Mitochondrial DNA and retroviral RNA analyses of archival oral polio vaccine (OPV CHAT) materials: evidence of macaque nuclear sequences confirms substrate identity.

PubMed

Berry, Neil; Jenkins, Adrian; Martin, Javier; Davis, Clare; Wood, David; Schild, Geoffrey; Bottiger, Margareta; Holmes, Harvey; Minor, Philip; Almond, Neil

2005-02-25

Inoculation of live experimental oral poliovirus vaccines (OPV CHAT) during the 1950s in central Africa has been proposed to account for the introduction of HIV into human populations. For this to have occurred, it would have been necessary for chimpanzee rather than macaque kidney epithelial cells to have been included in the preparation of early OPV materials. Theoretically, this could have led to contamination with a progenitor of HIV-1 derived from a related simian immunodeficiency virus of chimpanzees (SIVCPZ). In this article we present further detailed analyses of two samples of OPV, CHAT 10A-11 and CHAT 6039/Yugo, which were used in early human trials of poliovirus vaccination. Recovery of poliovirus by culture techniques confirmed the biological viability of the vaccines and sequence analysis of poliovirus RNA specifically identified the presence of the CHAT strain. Independent nested sets of oligonucleotide primers specific for HIV-1/SIVCPZ and HIV-2/SIVMAC/SIVSM phylogenetic lineages, respectively, indicated no evidence of HIV/SIV RNA in either vaccine preparation, at a sensitivity of 100 RNA equivalents/ml. Analysis of cellular substrate by the amplification of two distinct regions of mitochondrial DNA (D-loop control region and 12S ribosomal sequences) revealed no evidence of chimpanzee cellular sequences. However, this approach positively identified rhesus and cynomolgus macaque DNA for the CHAT 10A-11 and CHAT 6039/Yugo vaccine preparations, respectively. Analysis of multiple clones of mtDNA 12S rDNA indicated a relatively high number of nuclear mitochondrial DNA sequences (numts) in the CHAT 10A-11 material, but confirmed the macaque origin of cellular substrate used in vaccine preparation. These data reinforce earlier findings on this topic providing no evidence to support the contention that poliovirus vaccination was responsible for the introduction of HIV into humans and sparking the AIDS pandemic.

Internet Relay Chat as a Tool in the Autonomous Development of ESL Learners' English Language Ability: An Exploratory Study

ERIC Educational Resources Information Center

Coniam, David; Wong, Richard

2004-01-01

This pilot study explores the use of Internet Relay Chat facilities such as ICQ in an independent-use mode, as a vehicle for potential English language enhancement. In a small-scale study, a number of Hong Kong secondary school students (Grades 7-10) agreed to participate in an on-line "chatting" programme (in a text-only mode) for a minimum of 20…

Effects of Interactive Chat versus Independent Writing on L2 Learning

ERIC Educational Resources Information Center

Tare, Medha; Golonka, Ewa M.; Vatz, Karen; Bonilla, Carrie L.; Crooks, Carolyn; Strong, Rachel

2014-01-01

This study examines the importance of interaction for second language (L2) acquisition by analyzing outcomes from two types of out-of-class activities. The study compared: (a) interactive homework, completed via text chat, and (b) individual homework, completed via independent writing. In a between-subjects design, participants in two…

Conversation Thread Extraction and Topic Detection in Text-Based Chat

DTIC Science & Technology

2008-09-01

conversation extraction task. Multiple conversations in a session are interleaved. The goal in extraction is to select only those posts that belong...others. Our first-phase experiments quite clearly show the value of using time-distance as a feature in conversation thread extraction . In this set of... EXTRACTION AND TOPIC DETECTION IN TEXT-BASED CHAT by Paige Holland Adams September 2008 Thesis Advisor

Global profiling of lysine acetylation in human histoplasmosis pathogen Histoplasma capsulatum.

PubMed

Xie, Longxiang; Fang, Wenjie; Deng, Wanyan; Yu, Zhaoxiao; Li, Juan; Chen, Min; Liao, Wanqing; Xie, Jianping; Pan, Weihua

2016-04-01

Histoplasma capsulatum is the causative agent of human histoplasmosis, which can cause respiratory and systemic mycosis in immune-compromised individuals. Lysine acetylation, a protein posttranslational protein modification, is widespread in both eukaryotes and prokaryotes. Although increasing evidence suggests that lysine acetylation may play critical roles in fungus physiology, very little is known about its extent and function in H. capsulatum. To comprehensively profile protein lysine acetylation in H. capsulatum, we performed a global acetylome analysis through peptide prefractionation, antibody enrichment, and LC-MS/MS analysis, identifying 775 acetylation sites on 456 acetylated proteins; and functionally analysis showing their involvement in different biological processes. We defined six types of acetylation site motifs, and the results imply that lysine residue of polypeptide with tyrosine at the -1 and +1 positions, histidine at the +1 position, and phenylalanine (F) at the +1 and +2 position is a preferred substrate of lysine acetyltransferase. Moreover, some virulence factors candidates including calmodulin and DnaK are acetylated. In conclusion, our data set may serve as an important resource for the elucidation of associations between functional protein lysine acetylation and virulence in H. capsulatum. Copyright © 2016 Elsevier Ltd. All rights reserved.

The usability of a WeChat-based electronic questionnaire for collecting participant-reported data in female pelvic floor disorders: a comparison with the traditional paper-administered format.

PubMed

Sun, Zhi-Jing; Zhu, Lan; Liang, Maolian; Xu, Tao; Lang, Jing-He

2016-08-01

WeChat is a promising tool for capturing electronic data; however, no research has examined its use. This study evaluates the reliability and feasibility of WeChat for administering the Pelvic Floor Impact Questionnaire Short Form 7 questionnaire to women with pelvic floor disorders. Sixty-eight pelvic floor rehabilitation women were recruited between June and December 2015 and crossover randomized to two groups. All participants completed two questionnaire formats. One group completed the paper version followed by the WeChat version; the other group completed the questionnaires in reverse order. Two weeks later, each group completed the two versions in reverse order. The WeChat version's reliability was assessed using intraclass correlation coefficients and test-retest reliability. Forty-two women (61.8%) preferred the WeChat to the paper format, eight (11.8%) preferred the paper format, and 18 (26.5%) had no preference. The younger women preferred WeChat. Completion time was 116.5 (61.3) seconds for the WeChat version and 133.4 (107.0) seconds for the paper version, with no significant difference (P = 0.145). Age and education did not impact completion time (P > 0.05). Consistency between the WeChat and paper versions was excellent. The intraclass correlation coefficients of the Pelvic Floor Impact Questionnaire Short Form 7 and the three subscales ranged from 0.915 to 0.980. The Bland-Altman analysis and linear regression results also showed high consistency. The test-retest study had a Pearson's correlation coefficient of 0.908, demonstrating a strong correlation. WeChat-based questionnaires were well accepted by women with pelvic floor disorders and had good data quality and reliability.

[Human drug metabolizing enzymes. II. Conjugation enzymes].

PubMed

Vereczkey, L; Jemnitz, K; Gregus, Z

1998-09-01

In this review we focus on human conjugation enzymes (UDP-glucuronyltransferases, methyl-trasferases, N-acetyl-transferases, O-acetyl-transferases, Amidases/carboxyesterases, sulfotransferases, Glutation-S-transferases and the enzymes involved in the conjugation with amino acids) that participate in the metabolism of xenobiotics. Although conjugation reactions in most of the cases result in detoxication, more and more publications prove that the reactions catalysed by these enzymes very often lead to activated molecules that may attack macromolecules (proteins, RNAs, DNAs), resulting in toxicity (liver, neuro-, embryotoxicity, allergy, carcinogenecity). We have summarised the data available on these enzymes concerning their catalytic profile and specificity, inhibition, induction properties, their possible role in the generation of toxic compounds, their importance in clinical practice and drug development.

Chatting in L2 Spanish: Interactivity, Self-Efficacy and Interpersonal Relations

ERIC Educational Resources Information Center

Sanchez-Castro, Olga; Mrowa-Hopkins, Colette

2012-01-01

This study seeks to examine variations in patterns of interactivity as they are displayed in the ongoing discourse construction of high and low self-efficacy learners of Spanish in the context of computer-mediated-communication. The paper specifically focuses on the analysis of synchronous text chats of six university students of Spanish at…

Sleep in Individuals with Cri du Chat Syndrome: A Comparative Study

ERIC Educational Resources Information Center

Maas, A. P. H. M.; Didden, R.; Korzilius, H.; Braam, W.; Smits, M. G.; Curfs, L. M. G.

2009-01-01

Background: Sleep problems are common in individuals with intellectual disability. Little is known about sleep in children and adults with Cri du Chat syndrome (CDC). Method: Sleep was investigated in 30 individuals with CDC using a sleep questionnaire. Sleep problems and sleep behaviours in individuals with CDC were compared with individuals with…

Comparing Six Video Chat Tools: A Critical Evaluation by Language Teachers

ERIC Educational Resources Information Center

Eroz-Tuga, Betil; Sadler, Randall

2009-01-01

This article presents a critical comparison of the usefulness and practicality of six CMC video chat tools (CUworld, ICQ, MSN Messenger, Paltalk, Skype, and Yahoo Messenger) from the perspective of language teaching professionals. This comparison is based on the results of a semester-long project between graduate students at an American university…

Chaotic Traversal (CHAT): Very Large Graphs Traversal Using Chaotic Dynamics

NASA Astrophysics Data System (ADS)

Changaival, Boonyarit; Rosalie, Martin; Danoy, Grégoire; Lavangnananda, Kittichai; Bouvry, Pascal

2017-12-01

Graph Traversal algorithms can find their applications in various fields such as routing problems, natural language processing or even database querying. The exploration can be considered as a first stepping stone into knowledge extraction from the graph which is now a popular topic. Classical solutions such as Breadth First Search (BFS) and Depth First Search (DFS) require huge amounts of memory for exploring very large graphs. In this research, we present a novel memoryless graph traversal algorithm, Chaotic Traversal (CHAT) which integrates chaotic dynamics to traverse large unknown graphs via the Lozi map and the Rössler system. To compare various dynamics effects on our algorithm, we present an original way to perform the exploration of a parameter space using a bifurcation diagram with respect to the topological structure of attractors. The resulting algorithm is an efficient and nonresource demanding algorithm, and is therefore very suitable for partial traversal of very large and/or unknown environment graphs. CHAT performance using Lozi map is proven superior than the, commonly known, Random Walk, in terms of number of nodes visited (coverage percentage) and computation time where the environment is unknown and memory usage is restricted.

Intrinsic Tau Acetylation Is Coupled to Auto-Proteolytic Tau Fragmentation

PubMed Central

Cohen, Todd J.; Constance, Brian H.; Hwang, Andrew W.; James, Michael; Yuan, Chao-Xing

2016-01-01

Tau proteins are abnormally aggregated in a range of neurodegenerative tauopathies including Alzheimer’s disease (AD). Recently, tau has emerged as an extensively post-translationally modified protein, among which lysine acetylation is critical for normal tau function and its pathological aggregation. Here, we demonstrate that tau isoforms have different propensities to undergo lysine acetylation, with auto-acetylation occurring more prominently within the lysine-rich microtubule-binding repeats. Unexpectedly, we identified a unique intrinsic property of tau in which auto-acetylation induces proteolytic tau cleavage, thereby generating distinct N- and C-terminal tau fragments. Supporting a catalytic reaction-based mechanism, mapping and mutagenesis studies showed that tau cysteines, which are required for acetyl group transfer, are also essential for auto-proteolytic tau processing. Further mass spectrometry analysis identified the C-terminal 2nd and 4th microtubule binding repeats as potential sites of auto-cleavage. The identification of acetylation-mediated auto-proteolysis provides a new biochemical mechanism for tau self-regulation and warrants further investigation into whether auto-catalytic functions of tau are implicated in AD and other tauopathies. PMID:27383765

Intrinsic Tau Acetylation Is Coupled to Auto-Proteolytic Tau Fragmentation.

PubMed

Cohen, Todd J; Constance, Brian H; Hwang, Andrew W; James, Michael; Yuan, Chao-Xing

2016-01-01

Tau proteins are abnormally aggregated in a range of neurodegenerative tauopathies including Alzheimer's disease (AD). Recently, tau has emerged as an extensively post-translationally modified protein, among which lysine acetylation is critical for normal tau function and its pathological aggregation. Here, we demonstrate that tau isoforms have different propensities to undergo lysine acetylation, with auto-acetylation occurring more prominently within the lysine-rich microtubule-binding repeats. Unexpectedly, we identified a unique intrinsic property of tau in which auto-acetylation induces proteolytic tau cleavage, thereby generating distinct N- and C-terminal tau fragments. Supporting a catalytic reaction-based mechanism, mapping and mutagenesis studies showed that tau cysteines, which are required for acetyl group transfer, are also essential for auto-proteolytic tau processing. Further mass spectrometry analysis identified the C-terminal 2nd and 4th microtubule binding repeats as potential sites of auto-cleavage. The identification of acetylation-mediated auto-proteolysis provides a new biochemical mechanism for tau self-regulation and warrants further investigation into whether auto-catalytic functions of tau are implicated in AD and other tauopathies.

After Action Review Tools For Team Training with Chat Communications

DTIC Science & Technology

2009-11-01

collaborative learning environments. The most relevant work is being done by the CALO ( Cognitive Agent that Learns and Organizes) project, a joint...emoticons, and other common stylistic practices. To a lesser degree, some research has yielded methods and tools to analyze or visualize chat...information sources, and overall cognitive effort. AAR Challenges The most significant challenge to conducting an effective after action review of

"De-humanised females and Amazonians": British wartime fashion and its representation in Home chat, 1914-1918.

PubMed

Buckley, Cheryl

2002-01-01

Popular representations of the fashionably dressed female body between 1914 and 1918 were highly contradictory and, as this essay will show, were sharply delineated in Home Chat, one of a growing number of relatively new women's magazines which addressed the needs of an expanding skilled working-class and lower-middle-class female readership. Aiming to provide women with practical advice about all aspects of their daily lives, from the traditional concerns of fashion and beauty, marriage and children, to the more contentious issue of women's aspirations beyond the home, Home Chat was uniquely placed to reflect shifting gender and class relations.

Administrator Bridenstine Chats with Astronauts on This Week @NASA – June 15, 2018

NASA Image and Video Library

2018-06-15

Administrator Bridenstine chats with a couple of our astronauts, a massive dust storm on Mars, and astronauts at work outside the space station … a few of the stories to tell you about – This Week at NASA!

Acetyl radical generation in cigarette smoke: Quantification and simulations

NASA Astrophysics Data System (ADS)

Hu, Na; Green, Sarah A.

2014-10-01

Free radicals are present in cigarette smoke and can have a negative effect on human health. However, little is known about their formation mechanisms. Acetyl radicals were quantified in tobacco smoke and mechanisms for their generation were investigated by computer simulations. Acetyl radicals were trapped from the gas phase using 3-amino-2, 2, 5, 5-tetramethyl-proxyl (3AP) on solid support to form stable 3AP adducts for later analysis by high-performance liquid chromatography (HPLC), mass spectrometry/tandem mass spectrometry (MS-MS/MS) and liquid chromatography-mass spectrometry (LC-MS). Simulations were performed using the Master Chemical Mechanism (MCM). A range of 10-150 nmol/cigarette of acetyl radical was measured from gas phase tobacco smoke of both commercial and research cigarettes under several different smoking conditions. More radicals were detected from the puff smoking method compared to continuous flow sampling. Approximately twice as many acetyl radicals were trapped when a glass fiber particle filter (GF/F specifications) was placed before the trapping zone. Simulations showed that NO/NO2 reacts with isoprene, initiating chain reactions to produce hydroxyl radical, which abstracts hydrogen from acetaldehyde to generate acetyl radical. These mechanisms can account for the full amount of acetyl radical detected experimentally from cigarette smoke. Similar mechanisms may generate radicals in second hand smoke.

GLUTATHIONE S-TRANSFERASE-MEDIATED METABOLISM OF BROMODICHLOROMETHANE

EPA Science Inventory

GLUTATHIONE s-TRANSFERASE-MEDIATED METABOLISM OF BROMODICHLOROMETHANE. M K Ross1 and R A Pegram2. 1Curriculum in Toxicology, University of North Carolina at Chapel Hill; 2Experimental Toxicology Division, NHEERL/ORD, United States Environmental Protection Agency, Research Triangl...

The acetylation of insulin

PubMed Central

Lindsay, D. G.; Shall, S.

1971-01-01

The acetylation of the free amino groups of insulin was studied by reaction of the hormone with N-hydroxysuccinimide acetate at pH6.9 and 8.5. The products formed were separated by chromatography on DEAE-Sephadex and were characterized by isoelectric focusing, by end-group analysis, by the incorporation of [3H]acetyl groups in the molecule, and by treatment with trypsin that had been treated with 1-chloro-4-phenyl-3-toluene-p-sulphonamidobutan-2-one (`tosylphenylalanyl chloromethyl ketone'). Three monosubstituted products, two disubstituted products and one trisubstituted derivative were prepared. The α-amino groups of the terminal residues and the ∈-amino group of the lysine-B29 were the sites of reaction. Acetylation of any of the free amino groups did not affect the biological activity of insulin. It was demonstrated, however, that substitution at the glycine-A1 amino group by the larger residues, acetoacetyl or thiazolidinecarbonyl, produced a decrease in biological activity. Modification of the lysine-B29 or phenylalanine-B1 amino groups with these larger reagents did not affect the biological activity. Modification of the phenylalanine-B1 amino group by any of the three substituents resulted in a large decrease in the affinity of insulin for anti-insulin antibodies raised in the guinea pig. Modification of the other two amino groups did not affect the reaction with antibody. These observations are correlated with the tertiary structure of insulin. ImagesFig. 4. PMID:5113488

Positive screening on the Modified Checklist for Autism in Toddlers (M-CHAT) in extremely low gestational age newborns.

PubMed

Kuban, Karl C K; O'Shea, T Michael; Allred, Elizabeth N; Tager-Flusberg, Helen; Goldstein, Donald J; Leviton, Alan

2009-04-01

To test the hypothesis that children born preterm are more likely to screen positive on the M-CHAT for an autism spectrum disorder. We compared the M-CHAT positive rate of those with cerebral palsy, cognitive impairment, and vision and hearing impairments to those without such deficits. Relative to children who could walk, the odds for screening positive on the M-CHAT were increased 23-fold for those unable to sit or stand independently and more than 7-fold for those requiring assistance to walk. Compared with children without a diagnosis of cerebral palsy, those with quadriparesis were 13 times more likely to screen positive, and those with hemiparesis were 4 times more likely to screen positive. Children with major vision or hearing impairments were 8 times more likely to screen positive than those without such impairments. Relative to those with a Mental Development Index (MDI) of >70, the odds for screening positive were increased 13-fold for those with an MDI of <55 and more than 4-fold for those with an MDI of 55 to 69. Major motor, cognitive, visual, and hearing impairments appear to account for more than half of the positive M-CHAT screens in extremely low gestational age newborns. Even after those with such impairments were eliminated, 10% of children--nearly double the expected rate--screened positive.

Fluorescent techniques for discovery and characterization of phosphopantetheinyl transferase inhibitors

PubMed Central

Kosa, Nicolas M.; Foley, Timothy L.; Burkart, Michael D.

2016-01-01

Phosphopantetheinyl transferase (E.C. 2.7.8.-) activates biosynthetic pathways that synthesize both primary and secondary metabolites in bacteria. Inhibitors of these enzymes have the potential to serve as antibiotic compounds that function through a unique mode of action and possess clinical utility. Here we report a direct and continuous assay for this enzyme class based upon monitoring polarization of a fluorescent phosphopantetheine analog as it is transferred from a low molecular weight coenzyme A substrate to higher molecular weight protein acceptor. We demonstrate the utility of this method for the biochemical characterization of phosphopantetheinyl transferase Sfp, a canonical representative from this class. We also establish the portability of this technique to other homologs by adapting the assay to function with the human phosphopantetheinyl transferase, a target for which a microplate detection method does not currently exist. Comparison of these targets provides a basis to predict therapeutic index of inhibitor candidates and offers a valuable characterization of enzyme activity. PMID:24192555

Acetyl group coordinated progression through the catalytic cycle of an arylalkylamine N-acetyltransferase.

PubMed

Aboalroub, Adam A; Bachman, Ashleigh B; Zhang, Ziming; Keramisanou, Dimitra; Merkler, David J; Gelis, Ioannis

2017-01-01

The transfer of an acetyl group from acetyl-CoA to an acceptor amine is a ubiquitous biochemical transformation catalyzed by Gcn5-related N-acetyltransferases (GNATs). Although it is established that the reaction proceeds through a sequential ordered mechanism, the role of the acetyl group in driving the ordered formation of binary and ternary complexes remains elusive. Herein, we show that CoA and acetyl-CoA alter the conformation of the substrate binding site of an arylalkylamine N-acetyltransferase (AANAT) to facilitate interaction with acceptor substrates. However, it is the presence of the acetyl group within the catalytic funnel that triggers high affinity binding. Acetyl group occupancy is relayed through a conserved salt bridge between the P-loop and the acceptor binding site, and is manifested as differential dynamics in the CoA and acetyl-CoA-bound states. The capacity of the acetyl group carried by an acceptor to promote its tight binding even in the absence of CoA, but also its mutually exclusive position to the acetyl group of acetyl-CoA underscore its importance in coordinating the progression of the catalytic cycle.

Acetyl group coordinated progression through the catalytic cycle of an arylalkylamine N-acetyltransferase

PubMed Central

Aboalroub, Adam A.; Bachman, Ashleigh B.; Zhang, Ziming; Keramisanou, Dimitra; Merkler, David J.

2017-01-01

The transfer of an acetyl group from acetyl-CoA to an acceptor amine is a ubiquitous biochemical transformation catalyzed by Gcn5-related N-acetyltransferases (GNATs). Although it is established that the reaction proceeds through a sequential ordered mechanism, the role of the acetyl group in driving the ordered formation of binary and ternary complexes remains elusive. Herein, we show that CoA and acetyl-CoA alter the conformation of the substrate binding site of an arylalkylamine N-acetyltransferase (AANAT) to facilitate interaction with acceptor substrates. However, it is the presence of the acetyl group within the catalytic funnel that triggers high affinity binding. Acetyl group occupancy is relayed through a conserved salt bridge between the P-loop and the acceptor binding site, and is manifested as differential dynamics in the CoA and acetyl-CoA-bound states. The capacity of the acetyl group carried by an acceptor to promote its tight binding even in the absence of CoA, but also its mutually exclusive position to the acetyl group of acetyl-CoA underscore its importance in coordinating the progression of the catalytic cycle. PMID:28486510

Enzymic synthesis of indole-3-acetyl-1-O-beta-d-glucose. I. Partial purification and characterization of the enzyme from Zea mays

NASA Technical Reports Server (NTRS)

Leznicki, A. J.; Bandurski, R. S.

1988-01-01

The first enzyme-catalyzed reaction leading from indole-3-acetic acid (IAA) to the myo-inositol esters of IAA is the synthesis of indole-3-acetyl-1-O-beta-D-glucose from uridine-5'-diphosphoglucose (UDPG) and IAA. The reaction is catalyzed by the enzyme, UDPG-indol-3-ylacetyl glucosyl transferase (IAA-glucose-synthase). This work reports methods for the assay of the enzyme and for the extraction and partial purification of the enzyme from kernels of Zea mays sweet corn. The enzyme has an apparent molecular weight of 46,500 an isoelectric point of 5.5, and its pH optimum lies between 7.3 and 7.6. The enzyme is stable to storage at zero degrees but loses activity during column chromatographic procedures which can be restored only fractionally by addition of column eluates. The data suggest either multiple unknown cofactors or conformational changes leading to activity loss.

A visible dominant marker for insect transgenesis

PubMed Central

Osanai-Futahashi, Mizuko; Ohde, Takahiro; Hirata, Junya; Uchino, Keiro; Futahashi, Ryo; Tamura, Toshiki; Niimi, Teruyuki; Sezutsu, Hideki

2012-01-01

Transgenesis of most insects currently relies on fluorescence markers. Here we establish a transformation marker system causing phenotypes visible to the naked eye due to changes in the color of melanin pigments, which are widespread in animals. Ubiquitous overexpression of arylalkylamine-N-acetyl transferase in the silkworm, Bombyx mori, changes the color of newly hatched first-instar larvae from black to a distinctive light brown color, and can be used as a molecular marker by directly connecting to baculovirus immediate early 1 gene promoter. Suppression of black pigmentation by Bm-arylalkylamine-N-acetyl transferase can be observed throughout the larval stages and in adult animals. Alternatively, overexpression in another gene, B. mori β-alanyl-dopamine synthetase (Bm-ebony), changes the larval body color of older instars, although first-instar larvae had normal dark coloration. We further show that ectopic Bm-arylalkylamine-N-acetyl transferase expression lightens coloration in ladybird beetle Harmonia axyridis and fruit fly Drosophila melanogaster, highlighting the potential usefulness of this marker for transgenesis in diverse insect taxa. PMID:23250425

A visible dominant marker for insect transgenesis.

PubMed

Osanai-Futahashi, Mizuko; Ohde, Takahiro; Hirata, Junya; Uchino, Keiro; Futahashi, Ryo; Tamura, Toshiki; Niimi, Teruyuki; Sezutsu, Hideki

2012-01-01

Transgenesis of most insects currently relies on fluorescence markers. Here we establish a transformation marker system causing phenotypes visible to the naked eye due to changes in the color of melanin pigments, which are widespread in animals. Ubiquitous overexpression of arylalkylamine-N-acetyl transferase in the silkworm, Bombyx mori, changes the color of newly hatched first-instar larvae from black to a distinctive light brown color, and can be used as a molecular marker by directly connecting to baculovirus immediate early 1 gene promoter. Suppression of black pigmentation by Bm-arylalkylamine-N-acetyl transferase can be observed throughout the larval stages and in adult animals. Alternatively, overexpression in another gene, B. mori β-alanyl-dopamine synthetase (Bm-ebony), changes the larval body color of older instars, although first-instar larvae had normal dark coloration. We further show that ectopic Bm-arylalkylamine-N-acetyl transferase expression lightens coloration in ladybird beetle Harmonia axyridis and fruit fly Drosophila melanogaster, highlighting the potential usefulness of this marker for transgenesis in diverse insect taxa.

Novel Inhibitors of Protein-Protein Interaction for Prostate Cancer Therapy

DTIC Science & Technology

2011-04-01

medical need. 7 REFERENCES 1. Babbar N, Hacker A, Huang Y, Casero RA Jr. Tumor necrosis factor alpha induces spermidine /spermine N-acetyl...PCa development and progression. We have published that activated androgen receptor (AR)-JunD complex induces spermidine /spermine N1-acetyl transferase

N-Acetyl and Glutamatergic Neurometabolites in Perisylvian Brain Regions of Methamphetamine Users.

PubMed

Tang, Jinsong; O'Neill, Joseph; Alger, Jeffry R; Shen, Zhiwei; Johnson, Maritza C; London, Edythe D

2018-05-21

Methamphetamine induces neuronal N-acetyl-aspartate synthesis in preclinical studies. In a preliminary human proton magnetic resonance spectroscopic imaging investigation, we also observed that N-acetyl-aspartate+N-acetyl-aspartyl-glutamate in right inferior frontal cortex correlated with years of heavy methamphetamine abuse. In the same brain region, glutamate+glutamine is lower in methamphetamine users than in controls and is negatively correlated with depression. N-acetyl and glutamatergic neurochemistries therefore merit further investigation in methamphetamine abuse and the associated mood symptoms. Magnetic resonance spectroscopic imaging was used to measure N-acetyl-aspartate+N-acetyl-aspartyl-glutamate and glutamate+glutamine in bilateral inferior frontal cortex and insula, a neighboring perisylvian region affected by methamphetamine, of 45 abstinent methamphetamine-dependent and 45 healthy control participants. Regional neurometabolite levels were tested for group differences and associations with duration of heavy methamphetamine use, depressive symptoms, and state anxiety. In right inferior frontal cortex, N-acetyl-aspartate+N-acetyl-aspartyl-glutamate correlated with years of heavy methamphetamine use (r = +0.45); glutamate+glutamine was lower in methamphetamine users than in controls (9.3%) and correlated negatively with depressive symptoms (r = -0.44). In left insula, N-acetyl-aspartate+N-acetyl-aspartyl-glutamate was 9.1% higher in methamphetamine users than controls. In right insula, glutamate+glutamine was 12.3% lower in methamphetamine users than controls and correlated negatively with depressive symptoms (r = -0.51) and state anxiety (r = -0.47). The inferior frontal cortex and insula show methamphetamine-related abnormalities, consistent with prior observations of increased cortical N-acetyl-aspartate in methamphetamine-exposed animal models and associations between cortical glutamate and mood in human methamphetamine users.

Acetylproteomic Analysis Reveals Functional Implications of Lysine Acetylation in Human Spermatozoa (sperm)*

PubMed Central

Yu, Heguo; Diao, Hua; Wang, Chunmei; Lin, Yan; Yu, Fudong; Lu, Hui; Xu, Wei; Li, Zheng; Shi, Huijuan; Zhao, Shimin; Zhou, Yuchuan; Zhang, Yonglian

2015-01-01

Male infertility is a medical condition that has been on the rise globally. Lysine acetylation of human sperm, an essential posttranslational modification involved in the etiology of sperm abnormality, is not fully understood. Therefore, we first generated a qualified pan-anti-acetyllysine monoclonal antibody to characterize the global lysine acetylation of uncapacitated normal human sperm with a proteomics approach. With high enrichment ratios that were up to 31%, 973 lysine-acetylated sites that matched to 456 human sperm proteins, including 671 novel lysine acetylation sites and 205 novel lysine-acetylated proteins, were identified. These proteins exhibited conserved motifs XXXKYXXX, XXXKFXXX, and XXXKHXXX, were annotated to function in multiple metabolic processes, and were localized predominantly in the mitochondrion and cytoplasmic fractions. Between the uncapacitated and capacitated sperm, different acetylation profiles in regard to functional proteins involved in sperm capacitation, sperm-egg recognition, sperm-egg plasma fusion, and fertilization were observed, indicating that acetylation of functional proteins may be required during sperm capacitation. Bioinformatics analysis revealed association of acetylated proteins with diseases and drugs. Novel acetylation of voltage-dependent anion channel proteins was also found. With clinical sperm samples, we observed differed lysine acetyltransferases and lysine deacetylases expression between normal sperm and abnormal sperm of asthenospermia or necrospermia. Furthermore, with sperm samples impaired by epigallocatechin gallate to mimic asthenospermia, we observed that inhibition of sperm motility was partly through the blockade of voltage-dependent anion channel 2 Lys-74 acetylation combined with reduced ATP levels and mitochondrial membrane potential. Taken together, we obtained a qualified pan-anti-acetyllysine monoclonal antibody, analyzed the acetylproteome of uncapacitated human sperm, and revealed

WeChat Public Account Use Improves Clinical Control of Cough-Variant Asthma: A Randomized Controlled Trial.

PubMed

Cao, Yuan; Lin, Shi-Hua; Zhu, Ding; Xu, Feng; Chen, Zhi-Hua; Shen, Hua-Hao; Li, Wen

2018-03-14

BACKGROUND WeChat is a convenient and popular social medium, and it seems to be an appropriate platform for education and management of patients. This study sought to identify usefulness in clinical control of cough-variant asthma (CVA). MATERIAL AND METHODS A randomized controlled trial was conducted among 80 CVA patients. After being assigned to either the traditional group (TG) or the WeChat group (WG), they received the same inhalation therapy, but patients in WG received additional education and instruction via our public account on the WeChat application. Questionnaires on asthma and chronic cough, data on pulmonary function, blood-related items, follow-up adherence, and Emergency Department (ED) visits were collected at the initial visit and at 3 months. RESULTS A total of 67 participants completed the trial for analysis. FEV1/predicted and FEV1/FVC were significantly increased in WG (p<0.001; p=0.012) after 3 months. PD20-FEV1 was increased in both groups compared with baseline, but more pronounced in WG (p=0.004). ACQ-7 scores were improved in both groups (p=0.024; p<0.001). Participants allocated to WG experienced a greater improvement in AQLQ and LCQ scores, and between-group differences were significant at 3 months (p=0.040; p=0.001). Furthermore, we observed decreases in blood eosinophil count and FeNO in WG (p=0.048; p=0.014), and WG presented better follow-up compliance (p=0.034). CONCLUSIONS Using WeChat as part of treatment and management of CVA can help patients learn about their disease and medications, as well as improve disease control and therapy outcomes.

WeChat Public Account Use Improves Clinical Control of Cough-Variant Asthma: A Randomized Controlled Trial

PubMed Central

Cao, Yuan; Lin, Shi-Hua; Zhu, Ding; Xu, Feng; Chen, Zhi-Hua

2018-01-01

Background WeChat is a convenient and popular social medium, and it seems to be an appropriate platform for education and management of patients. This study sought to identify usefulness in clinical control of cough-variant asthma (CVA). Material/Methods A randomized controlled trial was conducted among 80 CVA patients. After being assigned to either the traditional group (TG) or the WeChat group (WG), they received the same inhalation therapy, but patients in WG received additional education and instruction via our public account on the WeChat application. Questionnaires on asthma and chronic cough, data on pulmonary function, blood-related items, follow-up adherence, and Emergency Department (ED) visits were collected at the initial visit and at 3 months. Results A total of 67 participants completed the trial for analysis. FEV1/predicted and FEV1/FVC were significantly increased in WG (p<0.001; p=0.012) after 3 months. PD20-FEV1 was increased in both groups compared with baseline, but more pronounced in WG (p=0.004). ACQ-7 scores were improved in both groups (p=0.024; p<0.001). Participants allocated to WG experienced a greater improvement in AQLQ and LCQ scores, and between-group differences were significant at 3 months (p=0.040; p=0.001). Furthermore, we observed decreases in blood eosinophil count and FeNO in WG (p=0.048; p=0.014), and WG presented better follow-up compliance (p=0.034). Conclusions Using WeChat as part of treatment and management of CVA can help patients learn about their disease and medications, as well as improve disease control and therapy outcomes. PMID:29536984

Chronic administration of tibolone modulates anxiety-like behavior and enhances cognitive performance in ovariectomized rats.

PubMed

Espinosa-Raya, Judith; Neri-Gómez, Teresa; Orozco-Suárez, Sandra; Campos, María G; Guerra-Araiza, Christian

2012-01-01

Hormone replacement therapy (HRT) may be prescribed to prevent the symptoms of menopause. This therapy may include estrogenic and/or progestin components and may increase the incidence of endometrial and breast cancers. Tibolone (TIB), which is also made up of estrogen and progestin components, is often used to reduce the impact of HRT. However, the effect of TIB on the processes of learning, memory and anxiety has yet to be fully elucidated. The aim of this study was to evaluate the long-term effect on learning, memory processes and anxiety in ovariectomized rats caused by different doses of TIB (0 mg/kg, 0.01 mg/kg, 0.1 mg/kg 1.0 mg/kg and 10 mg/kg, administered daily via the oral route for 18 weeks). Two behavioral animal models, the autoshaping and T maze models were employed. The concentrations of acetyl choline transferase (ChAT) and tryptophan hydroxylase (TPH) in the hippocampus were directly measured by Western blot. No significant changes were observed in the autoshaping model and spontaneous activity test. In the T maze, increased latency was observed with TIB doses of 1 and 10 mg/kg compared to the vehicle. We observed that the ChAT content decreased with increasing doses of TIB, whereas TPH content increased with doses of 1 and 10 mg/kg of TIB. These data indicate that high doses of TIB improved emotional learning, which may be related to the modulation of the cholinergic and serotonergic systems by TIB. Copyright © 2011 Elsevier Inc. All rights reserved.

A bioinformatics-based overview of protein Lys-Ne-acetylation

USDA-ARS?s Scientific Manuscript database

Among posttranslational modifications, there are some conceptual similarities between Lys-N'-acetylation and Ser/Thr/Tyr O-phosphorylation. Herein we present a bioinformatics-based overview of reversible protein Lys-acetylation, including some comparisons with reversible protein phosphorylation. T...

Molecular Cloning of Adenosinediphosphoribosyl Transferase.

DTIC Science & Technology

1987-09-08

nature of the blocking group is unknown, except its identity with pyroglutamic acid was ruled out by its insensitivity to pyroglutaminase (not shown...AdenosinediphosphoribOSyl Transferase (ADPRT) is: 1) the complete amino acid sequence of this large protein is best determined -from the DNA !equence of the gene, 2...enzyme (I), determination of its peptide structure (II) and application of synthetic DNA probes (III) derived from amino acid sequences, resulting in the

Researching Contradictions: Cultural Historical Activity Theory Research (CHAT) in the English Classroom

ERIC Educational Resources Information Center

Thompson, Ian

2015-01-01

This article argues that Cultural Historical Activity Theory (CHAT) is an appropriate theoretical and methodological framework for researchers in English interested in the social contexts of culture and its relationship with the formation of mind and activity in the English classroom. Two key concepts in Vygotsky's thought central to understanding…

NOK mediates glycolysis and nuclear PDC associated histone acetylation.

PubMed

Shi, Wei-Ye; Yang, Xiao; Huang, Bo; Shen, Wen H; Liu, Li

2017-06-01

NOK is a potent oncogene that can transform normal cells to cancer cells. We hypothesized that NOK might impact cancer cell metabolism and histone acetylation. We show that NOK localizes in the mitochondria, and while it minimally impacts tricarboxylic acid (TCA) cycle, it markedly inhibits the process of electron transport and oxidative phosphorylation processes and dramatically enhances aerobic glycolysis in cancer cells. NOK promotes the mitochondrial-nuclear translocation of pyruvate dehydrogenase complex (PDC), and enhances histone acetylation in the nucleus. Together, these findings show that NOK mediates glycolysis and nuclear PDC associated histone acetylation.

N-terminal acetylation modulates Bax targeting to mitochondria.

PubMed

Alves, Sara; Neiri, Leire; Chaves, Susana Rodrigues; Vieira, Selma; Trindade, Dário; Manon, Stephen; Dominguez, Veronica; Pintado, Belen; Jonckheere, Veronique; Van Damme, Petra; Silva, Rui Duarte; Aldabe, Rafael; Côrte-Real, Manuela

2018-02-01

The pro-apoptotic Bax protein is the main effector of mitochondrial permeabilization during apoptosis. Bax is controlled at several levels, including post-translational modifications such as phosphorylation and S-palmitoylation. However, little is known about the contribution of other protein modifications to Bax activity. Here, we used heterologous expression of human Bax in yeast to study the involvement of N-terminal acetylation by yNaa20p (yNatB) on Bax function. We found that human Bax is N-terminal (Nt-)acetylated by yNaa20p and that Nt-acetylation of Bax is essential to maintain Bax in an inactive conformation in the cytosol of yeast and Mouse Embryonic Fibroblast (MEF) cells. Bax accumulates in the mitochondria of yeast naa20Δ and Naa25 -/- MEF cells, but does not promote cytochrome c release, suggesting that an additional step is required for full activation of Bax. Altogether, our results show that Bax N-terminal acetylation by NatB is involved in its mitochondrial targeting. Copyright © 2017 Elsevier Ltd. All rights reserved.

Frequency and Content of Chat Questions by Time of Semester at the University of Central Florida: Implications for Training, Staffing and Marketing

ERIC Educational Resources Information Center

Goda, Donna; Bishop, Corinne

2008-01-01

The more than 4,000 "chats" received by the University of Central Florida's (UCF) Ask-A-Librarian digital reference service are the subject of this practitioner-based, descriptive case study. Question content from chats received during four semesters between January 2005 and May 2006 are categorized and plotted, by semester, to show the…

Oxotremorine infusions into the medial septal area of middle-aged rats affect spatial reference memory and ChAT activity.

PubMed

Frick, K M; Gorman, L K; Markowska, A L

1996-10-01

Age-related spatial memory deficits are correlated with septohippocampal cholinergic system degeneration. The present study examined the effect of intraseptal infusions of the cholinergic agonist, oxotremorine, on spatial reference memory in middle-aged rats using place discrimination in the water maze, and on cholinergic activity using choline acetyltransferase (ChAT) activity. Oxotremorine mildly improved the rate of place discrimination acquisition of middle-aged rats during initial sessions only, but did not affect asymptotic levels of performance achieved. Of the brain regions assayed, ChAT activity increased with age in the temporal cortex and dorsal CA2/3 region of the hippocampus. Oxotremorine significantly decreased ChAT activity in the dorsal hippocampus. In contrast to our previous results in aged rats indicating a more robust effect of oxotremorine on spatial working memory, the present results suggest a modest effect of intraseptal oxotremorine on the acquisition of a spatial reference memory task.

Chiral discrimination in cyclodextrin complexes of amino acid derivatives: beta-cyclodextrin/N-acetyl-L-phenylalanine and N-acetyl-D-phenylalanine complexes.

PubMed

Alexander, Jennifer M; Clark, Joanna L; Brett, Tom J; Stezowski, John J

2002-04-16

In a systematic study of molecular recognition of amino acid derivatives in solid-state beta-cyclodextrin (beta-CD) complexes, we have determined crystal structures for complexes of beta-cyclodextrin/N-acetyl-L-phenylalanine at 298 and 20 K and for N-acetyl-D-phenylalanine at 298 K. The crystal structures for the N-acetyl-L-phenylalanine complex present disordered inclusion complexes for which the distribution of guest molecules at room temperature is not resolvable; however, they can be located with considerable confidence at low temperature. In contrast, the complex with N-acetyl-D-phenylalanine is well ordered at room temperature. The latter complex presents an example of a complex in this series in which a water molecule is included deeply in the hydrophobic torus of the extended dimer host. In an effort to understand the mechanisms of molecular recognition giving rise to the dramatic differences in crystallographic order in these crystal structures, we have examined the intermolecular interactions in detail and have examined insertion of the enantiomer of the D-complex into the chiral beta-CD complex crystal lattice.

Chat It Up: Backchanneling to Promote Reflective Practice among In-Service Teachers

ERIC Educational Resources Information Center

Kassner, Laura D.; Cassada, Kate M.

2017-01-01

In a graduate education course geared toward developing reflective teaching practice in in-service teachers, backchannels, in the form of chat rooms, were employed in small groups to facilitate peer feedback during viewings of video recorded instruction. This study examined the nature and quality of peer feedback exchanged in the digital medium…

Identification and Functional Characterization of N-Terminally Acetylated Proteins in Drosophila melanogaster

PubMed Central

Gerrits, Bertran; Roschitzki, Bernd; Mohanty, Sonali; Niederer, Eva M.; Laczko, Endre; Timmerman, Evy; Lange, Vinzenz; Hafen, Ernst; Aebersold, Ruedi; Vandekerckhove, Joël; Basler, Konrad; Ahrens, Christian H.; Gevaert, Kris; Brunner, Erich

2009-01-01

Protein modifications play a major role for most biological processes in living organisms. Amino-terminal acetylation of proteins is a common modification found throughout the tree of life: the N-terminus of a nascent polypeptide chain becomes co-translationally acetylated, often after the removal of the initiating methionine residue. While the enzymes and protein complexes involved in these processes have been extensively studied, only little is known about the biological function of such N-terminal modification events. To identify common principles of N-terminal acetylation, we analyzed the amino-terminal peptides from proteins extracted from Drosophila Kc167 cells. We detected more than 1,200 mature protein N-termini and could show that N-terminal acetylation occurs in insects with a similar frequency as in humans. As the sole true determinant for N-terminal acetylation we could extract the (X)PX rule that indicates the prevention of acetylation under all circumstances. We could show that this rule can be used to genetically engineer a protein to study the biological relevance of the presence or absence of an acetyl group, thereby generating a generic assay to probe the functional importance of N-terminal acetylation. We applied the assay by expressing mutated proteins as transgenes in cell lines and in flies. Here, we present a straightforward strategy to systematically study the functional relevance of N-terminal acetylations in cells and whole organisms. Since the (X)PX rule seems to be of general validity in lower as well as higher eukaryotes, we propose that it can be used to study the function of N-terminal acetylation in all species. PMID:19885390

Modification of oil palm wood using acetylation and impregnation process

NASA Astrophysics Data System (ADS)

Subagiyo, Lambang; Rosamah, Enih; Hesim

2017-03-01

The purpose of this study is chemical modification by process of acetylation and impregnation of oil palm wood to improve the dimensional stability. Acetylation process aimed at substituting the hydroxyl groups in a timber with an acetyl group. By increasing the acetyl groups in wood is expected to reduce the ability of wood to absorb water vapor which lead to the dimensions of the wood becomes more stable. Studies conducted on oil palm wood (Elaeis guineensis Jacq) by acetylation and impregnation method. The results showed that acetylated and impregnated wood oil palm (E. guineensis Jacq) were changed in their physical properties. Impregnation with coal ashfly provide the greatest response to changes in weight (in wet conditions) and after conditioning (dry) with the average percentage of weight gain of 198.16% and 66.41% respectively. Changes in volume indicates an increase of volume in the wet condition (imbibition) with the coal ashfly treatment gave highest value of 23.04 %, whereas after conditioning (dry) the highest value obtained in the treatment of gum rosin:ethanol with a volume increase of 13:44%. The highest changes of the density with the coal ashfly impregnation in wet condition (imbibition) in value of 142.32% and after conditioning (dry) of 57.87%. The result of reduction in water absorption (RWA) test showed that in the palm oil wood samples most stable by using of gum rosin : ethanol of 0.97%, whereas the increase in oil palm wood dimensional stability (ASE) is the best of 59.42% after acetylation with Acetic Anhydride: Xylene.

Optimization of Clonazepam Therapy Adjusted to Patient's CYP3A Status and NAT2 Genotype.

PubMed

Tóth, Katalin; Csukly, Gábor; Sirok, Dávid; Belic, Ales; Kiss, Ádám; Háfra, Edit; Déri, Máté; Menus, Ádám; Bitter, István; Monostory, Katalin

2016-12-01

The shortcomings of clonazepam therapy include tolerance, withdrawal symptoms, and adverse effects such as drowsiness, dizziness, and confusion leading to increased risk of falls. Inter-individual variability in the incidence of adverse events in patients partly originates from the differences in clonazepam metabolism due to genetic and nongenetic factors. Since the prominent role in clonazepam nitro-reduction and acetylation of 7-amino-clonazepam is assigned to CYP3A and N-acetyl transferase 2 enzymes, respectively, the association between the patients' CYP3A status (CYP3A5 genotype, CYP3A4 expression) or N-acetyl transferase 2 acetylator phenotype and clonazepam metabolism (plasma concentrations of clonazepam and 7-amino-clonazepam) was evaluated in 98 psychiatric patients suffering from schizophrenia or bipolar disorders. The patients' CYP3A4 expression was found to be the major determinant of clonazepam plasma concentrations normalized by the dose and bodyweight (1263.5±482.9 and 558.5±202.4ng/mL per mg/kg bodyweight in low and normal expressers, respectively, P<.0001). Consequently, the dose requirement for the therapeutic concentration of clonazepam was substantially lower in low-CYP3A4 expresser patients than in normal expressers (0.029±0.011 vs 0.058±0.024mg/kg bodyweight, P<.0001). Furthermore, significantly higher (about 2-fold) plasma concentration ratio of 7-amino-clonazepam and clonazepam was observed in the patients displaying normal CYP3A4 expression and slower N-acetylation than all the others. Prospective assaying of CYP3A4 expression and N-acetyl transferase 2 acetylator phenotype can better identify the patients with higher risk of adverse reactions and can facilitate the improvement of personalized clonazepam therapy and withdrawal regimen. © The Author 2016. Published by Oxford University Press on behalf of CINP.

Optimization of Clonazepam Therapy Adjusted to Patient’s CYP3A Status and NAT2 Genotype

PubMed Central

Tóth, Katalin; Csukly, Gábor; Sirok, Dávid; Belic, Ales; Kiss, Ádám; Háfra, Edit; Déri, Máté; Menus, Ádám; Bitter, István

2016-01-01

Background: The shortcomings of clonazepam therapy include tolerance, withdrawal symptoms, and adverse effects such as drowsiness, dizziness, and confusion leading to increased risk of falls. Inter-individual variability in the incidence of adverse events in patients partly originates from the differences in clonazepam metabolism due to genetic and nongenetic factors. Methods: Since the prominent role in clonazepam nitro-reduction and acetylation of 7-amino-clonazepam is assigned to CYP3A and N-acetyl transferase 2 enzymes, respectively, the association between the patients’ CYP3A status (CYP3A5 genotype, CYP3A4 expression) or N-acetyl transferase 2 acetylator phenotype and clonazepam metabolism (plasma concentrations of clonazepam and 7-amino-clonazepam) was evaluated in 98 psychiatric patients suffering from schizophrenia or bipolar disorders. Results: The patients’ CYP3A4 expression was found to be the major determinant of clonazepam plasma concentrations normalized by the dose and bodyweight (1263.5±482.9 and 558.5±202.4ng/mL per mg/kg bodyweight in low and normal expressers, respectively, P<.0001). Consequently, the dose requirement for the therapeutic concentration of clonazepam was substantially lower in low-CYP3A4 expresser patients than in normal expressers (0.029±0.011 vs 0.058±0.024mg/kg bodyweight, P<.0001). Furthermore, significantly higher (about 2-fold) plasma concentration ratio of 7-amino-clonazepam and clonazepam was observed in the patients displaying normal CYP3A4 expression and slower N-acetylation than all the others. Conclusion: Prospective assaying of CYP3A4 expression and N-acetyl transferase 2 acetylator phenotype can better identify the patients with higher risk of adverse reactions and can facilitate the improvement of personalized clonazepam therapy and withdrawal regimen. PMID:27639091

Recognition Imaging of Acetylated Chromatin Using a DNA Aptamer

PubMed Central

Lin, Liyun; Fu, Qiang; Williams, Berea A.R.; Azzaz, Abdelhamid M.; Shogren-Knaak, Michael A.; Chaput, John C.; Lindsay, Stuart

2009-01-01

Histone acetylation plays an important role in the regulation of gene expression. A DNA aptamer generated by in vitro selection to be highly specific for histone H4 protein acetylated at lysine 16 was used as a recognition element for atomic force microscopy-based recognition imaging of synthetic nucleosomal arrays with precisely controlled acetylation. The aptamer proved to be reasonably specific at recognizing acetylated histones, with recognition efficiencies of 60% on-target and 12% off-target. Though this selectivity is much poorer than the >2000:1 equilibrium specificity of the aptamer, it is a large improvement on the performance of a ChIP-quality antibody, which is not selective at all in this application, and it should permit high-fidelity recognition with repeated imaging. The ability to image the precise location of posttranslational modifications may permit nanometer-scale investigation of their effect on chromatin structure. PMID:19751687

Acetylation of loofa (Luffa cylindrica) sponge as immobilization carrier for bioprocesses involving cellulase.

PubMed

Hideno, Akihiro; Ogbonna, James C; Aoyagi, Hideki; Tanaka, Hideo

2007-04-01

The feasibility of using loofa sponge for immobilization of cellulase-producing microorganisms was investigated by acetylating loofa sponge. Acetylation was achieved by autoclaving process of loofa sponge immersed in acetic anhydride at various temperatures for various times. The degree of acetylation, as inferred by the weight percentage gain (WPG), was enhanced by increasing both temperature and the duration of acetylation. The acetylation of a piece of loofa sponge in an autoclave at 120 degrees C for 20 min resulted in a WPG of about 8%, which was sufficient to protect the loofa sponge against cellulose degradation. The acetylated loofa sponge prepared under this condition was not decomposed by commercial cellulase and its structure was maintained for more than 720 h during repeated-batch treatments with commercial cellulase. A flocculating yeast (Saccharomyces cerevisiae IR-2) and a fungus (Trichoderma reesei QM9414) were successfully immobilized in the acetylated loofa sponge. In each case, the percentage of immobilized cells was as high as that obtained using nonacetylated loofa sponge. Acetylation had no adverse effects on cell growth and immobilization of T. reesei QM9414, as well as on cell growth and ethanol production by S. cerevisiae IR-2. T. reesei QM9414 immobilized on an acetylated loofa sponge was successfully used for repeated-batch cellulase production from commercial cellulose powder. Although the acetylated loofa sponge showed a slight weight loss, it was not disintegrated by activated sludge. The results obtained in this study showed that acetylated loofa sponge is suitable as an immobilization carrier for bioprocesses involving cellulase.

Loss-of-Function Mutation of REDUCED WALL ACETYLATION2 in Arabidopsis Leads to Reduced Cell Wall Acetylation and Increased Resistance to Botrytis cinerea1[W][OA

PubMed Central

Manabe, Yuzuki; Nafisi, Majse; Verhertbruggen, Yves; Orfila, Caroline; Gille, Sascha; Rautengarten, Carsten; Cherk, Candice; Marcus, Susan E.; Somerville, Shauna; Pauly, Markus; Knox, J. Paul; Sakuragi, Yumiko; Scheller, Henrik Vibe

2011-01-01

Nearly all polysaccharides in plant cell walls are O-acetylated, including the various pectic polysaccharides and the hemicelluloses xylan, mannan, and xyloglucan. However, the enzymes involved in the polysaccharide acetylation have not been identified. While the role of polysaccharide acetylation in vivo is unclear, it is known to reduce biofuel yield from lignocellulosic biomass by the inhibition of microorganisms used for fermentation. We have analyzed four Arabidopsis (Arabidopsis thaliana) homologs of the protein Cas1p known to be involved in polysaccharide O-acetylation in Cryptococcus neoformans. Loss-of-function mutants in one of the genes, designated REDUCED WALL ACETYLATION2 (RWA2), had decreased levels of acetylated cell wall polymers. Cell wall material isolated from mutant leaves and treated with alkali released about 20% lower amounts of acetic acid when compared with the wild type. The same level of acetate deficiency was found in several pectic polymers and in xyloglucan. Thus, the rwa2 mutations affect different polymers to the same extent. There were no obvious morphological or growth differences observed between the wild type and rwa2 mutants. However, both alleles of rwa2 displayed increased tolerance toward the necrotrophic fungal pathogen Botrytis cinerea. PMID:21212300

Conceptualisation and development of the Conversational Health Literacy Assessment Tool (CHAT).

PubMed

O'Hara, Jonathan; Hawkins, Melanie; Batterham, Roy; Dodson, Sarity; Osborne, Richard H; Beauchamp, Alison

2018-03-22

The aim of this study was to develop a tool to support health workers' ability to identify patients' multidimensional health literacy strengths and challenges. The tool was intended to be suitable for administration in healthcare settings where health workers must identify health literacy priorities as the basis for person-centred care. Development was based on a qualitative co-design process that used the Health Literacy Questionnaire (HLQ) as a framework to generate questions. Health workers were recruited to participate in an online consultation, a workshop, and two rounds of pilot testing. Participating health workers identified and refined ten questions that target five areas of assessment: supportive professional relationships, supportive personal relationships, health information access and comprehension, current health behaviours, and health promotion barriers and support. Preliminary evidence suggests that application of the Conversational Health Literacy Assessment Tool (CHAT) can support health workers to better understand the health literacy challenges and supportive resources of their patients. As an integrated clinical process, the CHAT can supplement existing intake and assessment procedures across healthcare settings to give insight into patients' circumstances so that decisions about care can be tailored to be more appropriate and effective.

Role of N-acetyltransferase 2 acetylation polymorphism in 4, 4'-methylene bis (2-chloroaniline) biotransformation.

PubMed

Hein, David W; Zhang, Xiaoyan; Doll, Mark A

2018-02-01

Arylamine N-acetyltransferase 1 (NAT1) and 2 (NAT2) catalyze the acetylation of arylamine carcinogens. Single nucleotide polymorphisms in the NAT2 coding exon present in NAT2 haplotypes encode allozymes with reduced N-acetyltransferase activity towards the N-acetylation of arylamine carcinogens and the O-acetylation of their N-hydroxylated metabolites. NAT2 acetylator phenotype modifies urinary bladder cancer risk following exposures to arylamine carcinogens such as 4-aminobiphenyl. 4, 4'-methylene bis (2-chloroaniline) (MOCA) is a Group 1 carcinogen for which a role of the NAT2 acetylation polymorphism on cancer risk is unknown. We investigated the role of NAT2 and the genetic acetylation polymorphism on both MOCA N-acetylation and N-hydroxy-MOCA O-acetylation. MOCA N-acetylation exhibited a robust gene dose response in rabbit liver cytosol and in cryopreserved human hepatocytes derived from individuals of rapid, intermediate and slow acetylator NAT2 genotype. MOCA exhibited about 4-fold higher affinity for recombinant human NAT2 than NAT1. Recombinant human NAT2*4 (reference) and 15 variant recombinant human NAT2 allozymes catalyzed both the N-acetylation of MOCA and the O-acetylation of N-hydroxy-MOCA. Human NAT2 5, NAT2 6, NAT2 7 and NAT2 14 allozymes catalyzed MOCA N-acetylation and N-hydroxy-O-acetylation at rates much lower than the reference NAT2 4 allozyme. In conclusion, our results show that NAT2 acetylator genotype has an important role in MOCA metabolism and suggest that risk assessments related to MOCA exposures consider accounting for NAT2 acetylator phenotype in the analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Collaboration via E-Mail and Internet Relay Chat: Understanding Time and Technology.

ERIC Educational Resources Information Center

Duin, Ann Hill; Archee, Ray

1996-01-01

Examines how college students working across distances used e-mail and Internet Relay Chat (IRC) to facilitate their collaboration and decision-making processes. Finds that students came to a decision more quickly using e-mail than with IRC, and when IRC was slow, students reverted to a series of rapid-fire e-mail messages. (RS)

Look At That! Video Chat and Joint Visual Attention Development Among Babies and Toddlers.

PubMed

McClure, Elisabeth R; Chentsova-Dutton, Yulia E; Holochwost, Steven J; Parrott, W G; Barr, Rachel

2018-01-01

Although many relatives use video chat to keep in touch with toddlers, key features of adult-toddler interaction like joint visual attention (JVA) may be compromised in this context. In this study, 25 families with a child between 6 and 24 months were observed using video chat at home with geographically separated grandparents. We define two types of screen-mediated JVA (across- and within-screen) and report age-related increases in the babies' across-screen JVA initiations, and that family JVA usage was positively related to babies' overall attention during video calls. Babies today are immersed in a digital world where formative relationships are often mediated by a screen. Implications for both infant social development and developmental research are discussed. © 2017 The Authors. Child Development © 2017 Society for Research in Child Development, Inc.

Curtain Time 20:00 GMT: Experiments in Virtual Theater on Internet Relay Chat.

ERIC Educational Resources Information Center

Danet, Brenda; And Others

1995-01-01

Analyzes the substantive and stylistic features of the "Hamnet" script (an 80-line parody of "Hamlet") as performed on Internet Relay Chat. Explicates the logistics of virtual production. Finds evidence for the democratization and globalization of culture in Hamnet productions. Suggests that Hamnet activities appeal primarily…

Acetylation contributes to hypertrophy-caused maturational delay of cardiac energy metabolism.

PubMed

Fukushima, Arata; Zhang, Liyan; Huqi, Alda; Lam, Victoria H; Rawat, Sonia; Altamimi, Tariq; Wagg, Cory S; Dhaliwal, Khushmol K; Hornberger, Lisa K; Kantor, Paul F; Rebeyka, Ivan M; Lopaschuk, Gary D

2018-05-17

A dramatic increase in cardiac fatty acid oxidation occurs following birth. However, cardiac hypertrophy secondary to congenital heart diseases (CHDs) delays this process, thereby decreasing cardiac energetic capacity and function. Cardiac lysine acetylation is involved in modulating fatty acid oxidation. We thus investigated what effect cardiac hypertrophy has on protein acetylation during maturation. Eighty-four right ventricular biopsies were collected from CHD patients and stratified according to age and the absence (n = 44) or presence of hypertrophy (n = 40). A maturational increase in protein acetylation was evident in nonhypertrophied hearts but not in hypertrophied hearts. The fatty acid β-oxidation enzymes, long-chain acyl CoA dehydrogenase (LCAD) and β-hydroxyacyl CoA dehydrogenase (βHAD), were hyperacetylated and their activities positively correlated with their acetylation after birth in nonhypertrophied hearts but not hypertrophied hearts. In line with this, decreased cardiac fatty acid oxidation and reduced acetylation of LCAD and βHAD occurred in newborn rabbits subjected to cardiac hypertrophy due to an aortocaval shunt. Silencing the mRNA of general control of amino acid synthesis 5-like protein 1 reduced acetylation of LCAD and βHAD as well as fatty acid oxidation rates in cardiomyocytes. Thus, hypertrophy in CHDs prevents the postnatal increase in myocardial acetylation, resulting in a delayed maturation of cardiac fatty acid oxidation.

Lysine acetylation sites prediction using an ensemble of support vector machine classifiers.

PubMed

Xu, Yan; Wang, Xiao-Bo; Ding, Jun; Wu, Ling-Yun; Deng, Nai-Yang

2010-05-07

Lysine acetylation is an essentially reversible and high regulated post-translational modification which regulates diverse protein properties. Experimental identification of acetylation sites is laborious and expensive. Hence, there is significant interest in the development of computational methods for reliable prediction of acetylation sites from amino acid sequences. In this paper we use an ensemble of support vector machine classifiers to perform this work. The experimentally determined acetylation lysine sites are extracted from Swiss-Prot database and scientific literatures. Experiment results show that an ensemble of support vector machine classifiers outperforms single support vector machine classifier and other computational methods such as PAIL and LysAcet on the problem of predicting acetylation lysine sites. The resulting method has been implemented in EnsemblePail, a web server for lysine acetylation sites prediction available at http://www.aporc.org/EnsemblePail/. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Changes in Acetyl CoA Levels during the Early Embryonic Development of Xenopus laevis

PubMed Central

Tsuchiya, Yugo; Pham, Uyen; Hu, Wanzhou; Ohnuma, Shin-ichi; Gout, Ivan

2014-01-01

Coenzyme A (CoA) is a ubiquitous and fundamental intracellular cofactor. CoA acts as a carrier of metabolically important carboxylic acids in the form of CoA thioesters and is an obligatory component of a multitude of catabolic and anabolic reactions. Acetyl CoA is a CoA thioester derived from catabolism of all major carbon fuels. This metabolite is at a metabolic crossroads, either being further metabolised as an energy source or used as a building block for biosynthesis of lipids and cholesterol. In addition, acetyl CoA serves as the acetyl donor in protein acetylation reactions, linking metabolism to protein post-translational modifications. Recent studies in yeast and cultured mammalian cells have suggested that the intracellular level of acetyl CoA may play a role in the regulation of cell growth, proliferation and apoptosis, by affecting protein acetylation reactions. Yet, how the levels of this metabolite change in vivo during the development of a vertebrate is not known. We measured levels of acetyl CoA, free CoA and total short chain CoA esters during the early embryonic development of Xenopus laevis using HPLC. Acetyl CoA and total short chain CoA esters start to increase around midblastula transition (MBT) and continue to increase through stages of gastrulation, neurulation and early organogenesis. Pre-MBT embryos contain more free CoA relative to acetyl CoA but there is a shift in the ratio of acetyl CoA to CoA after MBT, suggesting a metabolic transition that results in net accumulation of acetyl CoA. At the whole-embryo level, there is an apparent correlation between the levels of acetyl CoA and levels of acetylation of a number of proteins including histones H3 and H2B. This suggests the level of acetyl CoA may be a factor, which determines the degree of acetylation of these proteins, hence may play a role in the regulation of embryogenesis. PMID:24831956

Use of lidar point cloud data to support estimation of residual trace metals stored in mine chat piles in the Old Lead Belt of southeastern, Missouri

USGS Publications Warehouse

Witt, Emitt C.

2016-01-01

Historic lead and zinc (Pb-Zn) mining in southeast Missouri’s ―Old Lead Belt‖ has left large chat piles dominating the landscape where prior to 1972 mining was the major industry of the region. As a result of variable beneficiation methods over the history of mining activity, these piles remain with large quantities of unrecovered Pb and Zn and to a lesser extent cadmium (Cd). Quantifying the residual content of trace metals in chat piles is problematic because of the extensive field effort that must go into collecting elevation points for volumetric analysis. This investigation demonstrates that publicly available lidar point data from the U.S. Geological Survey 3D Elevation Program (3DEP) can be used to effectively calculate chat pile volumes as a method of more accurately estimating the total residual trace metal content in these mining wastes. Five chat piles located in St. Francois County, Missouri, were quantified for residual trace metal content. Utilizing lidar point cloud data collected in 2011 and existing trace metal concentration data obtained during remedial investigations, residual content of these chat piles ranged from 9247 to 88,579 metric tons Pb, 1925 to 52,306 metric tons Zn, and 51 to 1107 metric tons Cd. Development of new beneficiation methods for recovering these constituents from chat piles would need to achieve current Federal soil screening standards. To achieve this for the five chat piles investigated, 42 to 72% of residual Pb would require mitigation to the 1200 mg/kg Federal non-playground standard, 88 to 98% of residual Zn would require mitigation to the Ecological Soil Screening level (ESSL) for plant life, and 70% to 98% of Cd would require mitigation to achieve the ESSL. Achieving these goals through an existing or future beneficiation method(s) would remediate chat to a trace metal concentration level that would support its use as a safe agricultural soil amendment.

An Acetylation Switch Regulates SUMO-Dependent Protein Interaction Networks

PubMed Central

Ullmann, Rebecca; Chien, Christopher D.; Avantaggiati, Maria Laura; Muller, Stefan

2013-01-01

SUMMARY The attachment of the SUMO modifier to proteins controls cellular signaling pathways through noncovalent binding to SUMO-interaction motifs (SIMs). Canonical SIMs contain a core of hydrophobic residues that bind to a hydrophobic pocket on SUMO. Negatively charged residues of SIMs frequently contribute to binding by interacting with a basic surface on SUMO. Here we define acetylation within this basic interface as a central mechanism for the control of SUMO-mediated interactions. The acetyl-mediated neutralization of basic charges on SUMO prevents binding to SIMs in PML, Daxx, and PIAS family members but does not affect the interaction between RanBP2 and SUMO. Acetylation is controlled by HDACs and attenuates SUMO- and PIAS-mediated gene silencing. Moreover, it affects the assembly of PML nuclear bodies and restrains the recruitment of the corepressor Daxx to these structures. This acetyl-dependent switch thus expands the regulatory repertoire of SUMO signaling and determines the selectivity and dynamics of SUMO-SIM interactions. PMID:22578841

Discovery and characterization of sialic acid O-acetylation in group B Streptococcus.

PubMed

Lewis, Amanda L; Nizet, Victor; Varki, Ajit

2004-07-27

Group B Streptococcus (GBS) is the leading cause of human neonatal sepsis and meningitis. The GBS capsular polysaccharide is a major virulence factor and the active principle of vaccines in phase II trials. All GBS capsules have a terminal alpha 2-3-linked sialic acid [N-acetylneuraminic acid (Neu5Ac)], which interferes with complement-mediated killing. We show here that some of the Neu5Ac residues of the GBS type III capsule are O-acetylated at carbon position 7, 8, or 9, a major modification evidently missed in previous studies. Data are consistent with initial O-acetylation at position 7, and subsequent migration of the O-acetyl ester at positions 8 and 9. O-acetylation was also present on several other GBS serotypes (Ia, Ib, II, V, and VI). Deletion of the CMP-Neu5Ac synthase gene neuA by precise, in-frame allelic replacement gave intracellular accumulation of O-acetylated Neu5Ac, whereas overexpression markedly decreased O-acetylation. Given the known GBS Neu5Ac biosynthesis pathway, these data indicate that O-acetylation occurs on free Neu5Ac, competing with the CMP-Neu5Ac synthase. O-acetylation often generates immunogenic epitopes on bacterial capsular polysaccharides and can modulate human alternate pathway complement activation. Thus, our discovery has important implications for GBS pathogenicity, immunogenicity, and vaccine design.

Biosynthesis of 2-Hydroxyacid-Containing Polyhydroxyalkanoates by Employing butyryl-CoA Transferases in Metabolically Engineered Escherichia coli.

PubMed

David, Yokimiko; Joo, Jeong Chan; Yang, Jung Eun; Oh, Young Hoon; Lee, Sang Yup; Park, Si Jae

2017-11-01

The authors previously reported the production of polyhydroxyalkanoates (PHAs) containing 2-hydroxyacid monomers by expressing evolved Pseudomonas sp. 6-19 PHA synthase and Clostridium propionicum propionyl-CoA transferase in engineered microorganisms. Here, the authors examined four butyryl-CoA transferases from Roseburia sp., Eubacterium hallii, Faecalibacterium prausnitzii, and Anaerostipes caccae as potential CoA-transferases to support synthesis of polymers having 2HA monomer. In vitro activity analyses of the four butyryl-CoA transferases suggested that each butyryl-CoA transferase has different activities towards 2-hydroxybutyrate (2HB), 3-hydroxybutyrate (3HB), and lactate (LA). When Escherichia coli XL1-Blue expressing Pseudomonas sp. 6-19 PhaC1437 along with one butyryl-CoA transferase is cultured in chemically defined MR medium containing 20 g L -1 of glucose, 2 g L -1 of sodium 3-hydroxybutyrate, and various concentrations of sodium 2-hydroxybutyrate, PHAs consisting of 3HB, 2HB, and LA are produced. The monomer composition of PHAs agreed well with the substrate specificities of butyryl-CoA transferases from E. hallii, F. prausnitzii, and A. caccae, but not Roseburia sp. When E. coli XL1-Blue expressing PhaC1437 and E. hallii butyryl-CoA transferase is cultured in MR medium containing 20 g L -1 of glucose and 2 g L -1 of sodium 2-hydroxybutyrate, P(65.7 mol% 2HB-co-34.3 mol% LA) is produced with the highest PHA content of 30 wt%. Butyryl-CoA transferases also supported the production of P(3HB-co-2HB-co-LA) from glucose as the sole carbon source in E. coli XL1-Blue strains when one of these bct genes is expressed with phaC1437, cimA3.7, leuBCD, panE, and phaAB genes. Butyryl-CoA transferases characterized in this study can be used for engineering of microorganisms that produce PHAs containing novel 2-hydroxyacid monomers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Application of the MIDAS approach for analysis of lysine acetylation sites.

PubMed

Evans, Caroline A; Griffiths, John R; Unwin, Richard D; Whetton, Anthony D; Corfe, Bernard M

2013-01-01

Multiple Reaction Monitoring Initiated Detection and Sequencing (MIDAS™) is a mass spectrometry-based technique for the detection and characterization of specific post-translational modifications (Unwin et al. 4:1134-1144, 2005), for example acetylated lysine residues (Griffiths et al. 18:1423-1428, 2007). The MIDAS™ technique has application for discovery and analysis of acetylation sites. It is a hypothesis-driven approach that requires a priori knowledge of the primary sequence of the target protein and a proteolytic digest of this protein. MIDAS essentially performs a targeted search for the presence of modified, for example acetylated, peptides. The detection is based on the combination of the predicted molecular weight (measured as mass-charge ratio) of the acetylated proteolytic peptide and a diagnostic fragment (product ion of m/z 126.1), which is generated by specific fragmentation of acetylated peptides during collision induced dissociation performed in tandem mass spectrometry (MS) analysis. Sequence information is subsequently obtained which enables acetylation site assignment. The technique of MIDAS was later trademarked by ABSciex for targeted protein analysis where an MRM scan is combined with full MS/MS product ion scan to enable sequence confirmation.

Aberrant levels of histone H3 acetylation induce spermatid anomaly in mouse testis.

PubMed

Dai, Lei; Endo, Daisuke; Akiyama, Naotaro; Yamamoto-Fukuda, Tomomi; Koji, Takehiko

2015-02-01

Histone acetylation is involved in the regulation of chromatin structure and gene function. We reported previously that histone H3 acetylation pattern is subject to dynamic changes and limited to certain stages of germ cell differentiation during murine spermatogenesis, suggesting a crucial role for acetylation in the process. In the present study, we investigated the effects of hyper- and hypo-acetylation on spermatogenesis. Changes in acetylation level were induced by either in vivo administration of sodium phenylbutyrate, a histone deacetylase inhibitor, or by knockdown of histone acetyltransferases using short hairpin RNA plasmids transfection. Administration of sodium phenylbutyrate induced accumulation of acetylated histone H3 at lysine 9 and lysine 18 in round spermatids, together with spermatid morphological abnormalities and induction of apoptosis through a Bax-related pathway. Knockdown of steroid receptor coactivator 1, a member of histone acetyltransferases, but not general control of amino acid synthesis 5 nor elongator protein 3 by in vivo electroporation of shRNA plasmids, reduced acetylated histone H3 at lysine 9 in round spermatids, and induced morphological abnormalities. We concluded that the proper regulation of histone H3 acetylation levels is important for spermatid differentiation and complex chromatin remodeling during spermiogenesis.

NASA Hosts Live Science Chat about Europa Findings

NASA Image and Video Library

2018-05-14

NASA hosted a Science Chat May 14 to discuss the latest analysis of Jupiter’s moon Europa and its status as one of the most promising places in the solar system to search for life. The event aired live on NASA Television, Facebook Live, Twitch TV, Ustream, YouTube, Twitter/Periscope and the agency's website. Europa has long been a high priority for exploration because beneath its icy crust lies a salty, liquid water ocean. NASA’s Europa Clipper, targeted to launch in 2022, will be equipped with the instruments necessary to determine whether Europa possesses the ingredients necessary to support life as we know it.

Histone acetylation regulates the time of replication origin firing.

PubMed

Vogelauer, Maria; Rubbi, Liudmilla; Lucas, Isabelle; Brewer, Bonita J; Grunstein, Michael

2002-11-01

The temporal firing of replication origins throughout S phase in yeast depends on unknown determinants within the adjacent chromosomal environment. We demonstrate here that the state of histone acetylation of surrounding chromatin is an important regulator of temporal firing. Deletion of RPD3 histone deacetylase causes earlier origin firing and concurrent binding of the replication factor Cdc45p to origins. In addition, increased acetylation of histones in the vicinity of the late origin ARS1412 by recruitment of the histone acetyltransferase Gcn5p causes ARS1412 alone to fire earlier. These data indicate that histone acetylation is a direct determinant of the timing of origin firing.

Aspirin-Mediated Acetylation Protects Against Multiple Neurodegenerative Pathologies by Impeding Protein Aggregation.

PubMed

Ayyadevara, Srinivas; Balasubramaniam, Meenakshisundaram; Kakraba, Samuel; Alla, Ramani; Mehta, Jawahar L; Shmookler Reis, Robert J

2017-12-10

Many progressive neurological disorders, including Alzheimer's disease (AD), Huntington's disease, and Parkinson's disease (PD), are characterized by accumulation of insoluble protein aggregates. In prospective trials, the cyclooxygenase inhibitor aspirin (acetylsalicylic acid) reduced the risk of AD and PD, as well as cardiovascular events and many late-onset cancers. Considering the role played by protein hyperphosphorylation in aggregation and neurodegenerative diseases, and aspirin's known ability to donate acetyl groups, we asked whether aspirin might reduce both phosphorylation and aggregation by acetylating protein targets. Aspirin was substantially more effective than salicylate in reducing or delaying aggregation in human neuroblastoma cells grown in vitro, and in Caenorhabditis elegans models of human neurodegenerative diseases in vivo. Aspirin acetylates many proteins, while reducing phosphorylation, suggesting that acetylation may oppose phosphorylation. Surprisingly, acetylated proteins were largely excluded from compact aggregates. Molecular-dynamic simulations indicate that acetylation of amyloid peptide energetically disfavors its association into dimers and octamers, and oligomers that do form are less compact and stable than those comprising unacetylated peptides. Hyperphosphorylation predisposes certain proteins to aggregate (e.g., tau, α-synuclein, and transactive response DNA-binding protein 43 [TDP-43]), and it is a critical pathogenic marker in both cardiovascular and neurodegenerative diseases. We present novel evidence that acetylated proteins are underrepresented in protein aggregates, and that aggregation varies inversely with acetylation propensity after diverse genetic and pharmacologic interventions. These results are consistent with the hypothesis that aspirin inhibits protein aggregation and the ensuing toxicity of aggregates through its acetyl-donating activity. This mechanism may contribute to the neuro-protective, cardio

Induction of human umbilical Wharton's jelly-derived mesenchymal stem cells toward motor neuron-like cells.

PubMed

Bagher, Zohreh; Ebrahimi-Barough, Somayeh; Azami, Mahmoud; Mirzadeh, Hamid; Soleimani, Mansooreh; Ai, Jafar; Nourani, Mohammad Reza; Joghataei, Mohammad Taghi

2015-10-01

The most important property of stem cells from different sources is the capacity to differentiate into various cells and tissue types. However, problems including contamination, normal karyotype, and ethical issues cause many limitations in obtaining and using these cells from different sources. The cells in Wharton's jelly region of umbilical cord represent a pool source of primitive cells with properties of mesenchymal stem cells (MSCs). The aim of this study was to determine the potential of human Wharton's jelly-derived mesenchymal stem cells (WJMSCs) for differentiation to motor neuron cells. WJMSCs were induced to differentiate into motor neuron-like cells by using different signaling molecules and neurotrophic factors in vitro. Differentiated neurons were then characterized for expression of motor neuron markers including nestin, PAX6, NF-H, Islet 1, HB9, and choline acetyl transferase (ChAT) by quantitative reverse transcription PCR and immunocytochemistry. Our results showed that differentiated WJMSCs could significantly express motor neuron biomarkers in RNA and protein levels 15 d post induction. These results suggested that WJMSCs can differentiate to motor neuron-like cells and might provide a potential source in cell therapy for neurodegenerative disease.

Substance P and acetylcholine are co-localized in the pathway mediating mucociliary activity in Rana pipiens

PubMed Central

Hernández, C. J.; Ortíz, T.; Foster, C. Rosa K.; Tyagi, M; Lugo, N.; Albrecht, R.; Chinapen, S.

2007-01-01

Mucociliary activity is an important clearance mechanism in the respiratory system of air breathing vertebrates. Substance P (SP) and acetylcholine play a key role in the stimulation of the mucociliary transport in the frog palate. In this study, retrograde neuronal tracing was combined with immunocytochemistry for SP and choline acetyl transferase (ChAT) in the trigeminal ganglion and for neurokinin-1 receptor (NK1R) in the palate of Rana pipiens. The cells of origin of the palatine nerve were identified in the trigeminal ganglion using the retrograde tracer Fluorogold (FG). Optimal labeling of FG cells in the trigeminal ganglion was obtained at 96 h of exposure. Immunoflorescent shows that SP and acetylcholine are co-localized in 92% of the cells labeled with FG in the trigeminal ganglion. NK1 receptors were found in the membrane of epithelial and goblet cells of the palate. Ultrastructural study of the palate showed axonal-like endings with vesicles in connection with epithelial and goblet cells. These results further support the concerted action of both neurotransmitters in the regulation of mucociliary activity in the frog palate. PMID:17276713

AskNow!--Evaluating an Australian Collaborative Chat Reference Service: A Project Manager's Perspective

ERIC Educational Resources Information Center

Wilson, Fran; Keys, Jacki

2004-01-01

AskNow! online answers Australia-wide, the first nation-wide chat reference service, has been a successful exercise in collaboration and cooperation. This article examines some of the lessons learnt, the challenges of collaboration and possible future directions. AskNow!, an initiative of the Council of Australian State Libraries (CASL), commenced…

Text Chat during Video/Audio Conferencing Lessons: Scaffolding or Getting in the Way?

ERIC Educational Resources Information Center

Kozar, Olga

2016-01-01

Private online language tutoring is growing in popularity. An important prerequisite for development of effective pedagogies in this context is a good understanding of how different modalities can be combined. This study provides a detailed account of how several experienced private online teachers use text chat in their Skype-based English…

Preservice Teachers' Participation and Perceptions of Twitter Live Chats as Personal Learning Networks

ERIC Educational Resources Information Center

Luo, Tian; Sickel, Jamie; Cheng, Li

2017-01-01

This study presents two cases in which undergraduates were introduced to Twitter in their teacher preparation program as a means of developing a personal learning network. Twitter live chats are synchronous discussions that allow education stakeholders to discuss issues and share resources, engaging on potentially a global scale via the social…

Comparing Protest Movements in Chile and California: Interculturality in an Internet Chat Exchange

ERIC Educational Resources Information Center

Menard-Warwick, Julia

2009-01-01

This paper is based on an analysis of chat transcripts from an English-language telecollaboration project between students at universities in Chile and California. This research found that the richest intercultural interactions involved events that could not have been foreseen: the immigrant rights demonstrations in the USA and the massive student…

Reenergising Professional Creativity from a CHAT Perspective: Seeing Knowledge and History in Practice

ERIC Educational Resources Information Center

Ellis, Viv

2011-01-01

This article offers a critical examination of aspects of a practice- and theory-developing intervention in the teacher education setting in England designed as a variation of Developmental Work Research. A positive case is argued for the distinctiveness of such cultural-historical activity theory (CHAT-) informed interventions and some points of…

Acetylation of histone deacetylase 1 regulates NuRD corepressor complex activity.

PubMed

Yang, Tao; Jian, Wei; Luo, Yi; Fu, Xueqi; Noguchi, Constance; Bungert, Jörg; Huang, Suming; Qiu, Yi

2012-11-23

HDAC1-containing NuRD complex is required for GATA-1-mediated repression and activation. GATA-1 associated with acetylated HDAC1-containing NuRD complex, which has no deacetylase activity, for gene activation. Acetylated HDAC1 converts NuRD complex from a repressor to an activator during GATA-1-directed erythroid differentiation program. HDAC1 acetylation may function as a master regulator for the activity of HDAC1 containing complexes. Histone deacetylases (HDACs) play important roles in regulating cell proliferation and differentiation. The HDAC1-containing NuRD complex is generally considered as a corepressor complex and is required for GATA-1-mediated repression. However, recent studies also show that the NuRD complex is involved in GATA-1-mediated gene activation. We tested whether the GATA-1-associated NuRD complex loses its deacetylase activity and commits the GATA-1 complex to become an activator during erythropoiesis. We found that GATA-1-associated deacetylase activity gradually decreased upon induction of erythroid differentiation. GATA-1-associated HDAC1 is increasingly acetylated after differentiation. It has been demonstrated earlier that acetylated HDAC1 has no deacetylase activity. Indeed, overexpression of an HDAC1 mutant, which mimics acetylated HDAC1, promotes GATA-1-mediated transcription and erythroid differentiation. Furthermore, during erythroid differentiation, acetylated HDAC1 recruitment is increased at GATA-1-activated genes, whereas it is significantly decreased at GATA-1-repressed genes. Interestingly, deacetylase activity is not required for Mi2 remodeling activity, suggesting that remodeling activity may be required for both activation and repression. Thus, our data suggest that NuRD can function as a coactivator or repressor and that acetylated HDAC1 converts the NuRD complex from a repressor to an activator during GATA-1-directed erythroid differentiation.

Preparation and investigation of acetyl salicylic acid-caffeine complex for rectal administration.

PubMed

Fouad, Ehab A; El-Badry, Mahmoud; Alanazi, Fars K; Arafah, Maha M; Al-Ashban, Riyadh; Alsarra, Ibrahim A

2010-06-01

An acetyl salicylic acid-caffeine complex was prepared and evaluated for the potential use in rectal administration. The results revealed the formation of a complex between acetyl salicylic acid and caffeine in a 1:1 molar ratio by a charge transfer mechanism. The effects of acetyl salicylic acid and complex on the rectal tissues showed destruction in the mucosal epithelium in case of acetyl salicylic acid; however, no change in the rectal tissues was noticed upon the administration of the complex. The effect of suppository bases on the release of the complex was studied using Witepsol H15 as fatty base and polyethylene glycols (PEG) 1000 and 4000 as a water soluble suppository base. The release profiles of acetyl salicylic acid and the complex were faster from PEG than from that of Witepsol H15. The percent release for the complex and acetyl salicylic acid from PEG base were 45.8, and 34.9%, respectively. However, it was 8.7 and 7.8%, respectively, from Witepsol H15 fatty base. The release kinetic was found to follow the non-Fickian diffusion model for complex from the suppository bases. It was concluded that acetyl salicylic acid caffeine complex can be used safely for rectal administration.

Preparation and investigation of acetyl salicylic acid-caffeine complex for rectal administration.

PubMed

Fouad, Ehab A; El-Badry, Mahmoud; Alanazi, Fars K; Arafah, Maha M; Al-Ashban, Riyadh; Alsarra, Ibrahim A

2009-07-30

An acetyl salicylic acid-caffeine complex was prepared and evaluated for the potential use in rectal administration. The results revealed the formation of a complex between acetyl salicylic acid and caffeine in a 1:1 molar ratio by a charge transfer mechanism. The effects of acetyl salicylic acid and complex on the rectal tissues showed destruction in the mucosal epithelium in case of acetyl salicylic acid; however, no change in the rectal tissues was noticed upon the administration of the complex. The effect of suppository bases on the release of the complex was studied using Witepsol H15 as fatty base and polyethylene glycols (PEG) 1000 and 4000 as a water soluble suppository base. The release profiles of acetyl salicylic acid and the complex were faster from PEG than from that of Witepsol H15. The percent release for the complex and acetyl salicylic acid from PEG base were 45.8, and 34.9%, respectively. However, it was 8.7 and 7.8%, respectively, from Witepsol H15 fatty base. The release kinetic was found to follow the non-Fickian diffusion model for complex from the suppository bases. It was concluded that acetyl salicylic acid caffeine complex can be used safely for rectal administration.

Acetylation of aromatic cysteine conjugates by recombinant human N-acetyltransferase 8.

PubMed

Deol, Reema; Josephy, P David

2017-03-01

1. The mercapturic acid (MA) pathway is a metabolic route for the processing of glutathione conjugates to MA (N-acetylcysteine conjugates). An N-acetyltransferase enzyme, NAT8, catalyzes the transfer of an acetyl group from acetyl-CoA to the cysteine amino group, producing a MA, which is excreted in the urine. We expressed human NAT8 in HEK293T cells and developed an HPLC-MS method for the quantitation of the S-aryl-substituted cysteine conjugates and their MA. 2. We measured the activity of the enzyme for acetylation of benzyl-, 4-nitrobenzyl-, and 1-menaphthylcysteine substrates. 3. NAT8 catalyzed the acetylation of all three cysteine conjugates with similar Michaelis-Menten kinetics.

Mechanism of the lysosomal membrane enzyme acetyl coenzyme A: alpha-glucosaminide N-acetyltransferase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bame, K.J.

1986-01-01

Acetyl-CoA:..cap alpha..-glucosaminide N-acetyltransferase is a lysosomal membrane enzyme, deficient in the genetic disease Sanfilippo C syndrome. The enzyme catalyzes the transfer of an acetyl group from cytoplasmic acetyl-CoA to terminal ..cap alpha..-glucosamine residues of heparan sulfate within the organelle. The reaction mechanism was examined using high purified lysosomal membranes from rat liver and human fibroblasts. The N-acetyltransferase reaction is optimal above pH 5.5 and a 2-3 fold stimulation of activity is observed in the presence of 0.1% taurodeoxycholate. Double reciprocal analysis and product inhibition studies indicate that the enzyme works by a Di-Iso Ping Pong Bi Bi mechanism. The bindingmore » of acetyl-CoA to the enzyme is measured by exchange label from (/sup 3/H)CoA to acetyl-CoA, and is optimal at pH's above 7.0. The acetyl-enzyme intermediate is formed by incubating membranes with (/sup 3/H)acetyl-CoA. The acetyl group can be transferred to glucosamine, forming (/sup 3/H)N-acetylglucosamine; the transfer is optimal between pH 4 and 5. Lysosomal membranes from Sanfilippo C fibroblasts confirm that these half reactions carried out by the N-acetyltransferase. The enzyme is inactivated by N-bromosuccinimide and diethylpyrocarbonate, indicating that a histidine is involved in the reaction. These results suggest that the histidine residue is at the active site of the enzyme. The properties of the N-acetyltransferase in the membrane, the characterization of the enzyme kinetics, the chemistry of a histidine mediated acetylation and the pH difference across the lysosomal membrane all support a transmembrane acetylation mechanism.« less

Acetyl fentanyl overdose fatalities--Rhode Island, March-May 2013.

PubMed

2013-08-30

In May 2013, the Rhode Island State Health Laboratories noticed an unusual pattern of toxicology results among 10 overdose deaths of suspected illicit drug users that had occurred during March 7-April 11, 2013. An enzyme-linked immunosorbent assay (ELISA) for fentanyl in blood was positive for fentanyl in all 10 cases, but confirmatory gas chromatography/mass spectrometry (GC/MS) did not detect fentanyl. The mass spectrum was instead consistent with acetyl fentanyl, a fentanyl analog. Acetyl fentanyl, a synthetic opioid, has not been documented in illicit drug use or overdose deaths, and is not available as a prescription drug anywhere. Animal studies suggest that acetyl fentanyl is up to five times more potent than heroin as an analgesic.

Status Quo and Prospective of WeChat in Improving Chinese English Learners' Pronunciation

ERIC Educational Resources Information Center

Wang, Kanghui

2017-01-01

With the ubiquitous usage of wireless, portable, and handheld devices gaining popularity in 21st century, the revolutionary mobile technology introduces digital new media to educational settings, which has changed the way of traditional teaching and learning. WeChat is one of the most popular social networking applications in China featured by its…

Outcomes of Chat and Discussion Board Use in Online Learning: A Research Synthesis

ERIC Educational Resources Information Center

Blackmon, Stephanie J.

2012-01-01

Online discussion boards are often used in traditional courses, hybrid courses, and fully online courses. Online chats and discussions can be particularly useful in fully online courses, as these communication connections are often students' only means of connecting with each other and sharing ideas in an open forum. While traditional face-to-face…

P300/CBP acts as a coactivator to cartilage homeoprotein-1 (Cart1), paired-like homeoprotein, through acetylation of the conserved lysine residue adjacent to the homeodomain.

PubMed

Iioka, Takashi; Furukawa, Keizo; Yamaguchi, Akira; Shindo, Hiroyuki; Yamashita, Shunichi; Tsukazaki, Tomoo

2003-08-01

The paired-like homeoprotein, Cart1, is involved in skeletal development. We describe here that the general coactivator p300/CBP controls the transcription activity of Cart1 through acetylation of a lysine residue that is highly conserved in other homeoproteins. Acetylation of this residue increases the interaction between p300/CBP and Cart1 and enhances its transcriptional activation. Cart1 encodes a paired-like homeoprotein expressed selectively in chondrocyte lineage during embryonic development. Although its target gene remains unknown, gene disruption studies have revealed that Cart1 plays an important role for craniofacial bone formation as well as limb development by cooperating with another homeoprotein, Alx4. In this report, we study the functional involvement of p300/CBP, coactivators with intrinsic histone acetyltransferase (HAT) activity, in the transcriptional control of Cart1. To study the transcription activity of Cart1, a reporter construct containing a putative Cart1 binding site was transiently transfected with the expression vectors of each protein. The interaction between p300/CBP and Cart1 was investigated by glutathione S-transferase (GST) pull-down, yeast two-hybrid, and immunoprecipitation assays. In vitro acetylation assay was performed with the recombinant p300-HAT domain and Cart1 in the presence of acetyl-CoA. p300 and CBP stimulate Cart1-dependent transcription activity, and this transactivation is inhibited by E1A and Tax, oncoproteins that suppress the activity of p300/CBP. Cart1 binds to p300 in vivo and in vitro, and this requires the homeodomain of Cart 1 and N-terminal 139 amino acids of p300. Confocal microscopy analysis shows that Cart1 recruits overexpressed and endogenous p300 to a Cart1-specific subnuclear compartment. Cart1 is acetylated in vivo and sodium butyrate and trichostatin A, histone deacetylase inhibitors, markedly enhance the transcription activity of Cart1. Deletion and mutagenesis analysis identifies the 131st

First evaluation of the NHS direct online clinical enquiry service: a nurse-led web chat triage service for the public.

PubMed

Eminovic, Nina; Wyatt, Jeremy C; Tarpey, Aideen M; Murray, Gerard; Ingrams, Grant J

2004-06-02

NHS Direct is a telephone triage service used by the UK public to contact a nurse for any kind of health problem. NHS Direct Online (NHSDO) extends NHS Direct, allowing the telephone to be replaced by the Internet, and introducing new opportunities for informing patients about their health. One NHSDO service under development is the Clinical Enquiry Service (CES), which uses Web chat as the communication medium. To identify the opportunities and possible risks of such a service by exploring its safety, feasibility, and patient perceptions about using Web chat to contact a nurse. During a six-day pilot performed in an inner-city general practice in Coventry, non-urgent patients attending their GP were asked to test the service. After filling out three Web forms, patients used a simple Web chat application to communicate with trained NHS Direct triage nurses, who responded with appropriate triage advice. All patients were seen by their GP immediately after using the Web chat service. Safety was explored by comparing the nurse triage end point with the GP's recommended end point. In order to check the feasibility of the service, we measured the duration of the chat session. Patient perceptions were measured before and after using the service through a modified Telemedicine Perception Questionnaire (TMPQ) instrument. All patients were observed by a researcher who captured any comments and, if necessary, to assisted with the process. A total of 25 patients (mean age 48 years; 57% female) agreed to participate in the study. An exact match between the nurse and the GP end point was found in 45% (10/22) of cases. In two cases, the CES nurse proposed a less urgent end point than the GP. The median duration of Web chat sessions was 30 minutes, twice the median for NHS Direct telephone calls for 360 patients with similar presenting problems. There was a significant improvement in patients' perception of CES after using the service (mean pre-test TMPQ score 44/60, post-test 49

Cloning and expression of clostridium acetobutylicum ATCC 824 acetoacetyl-coenzyme A:acetate/butyrate:coenzyme A-transferase in Escherichia coli

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cary, J.W.; Petersen, D.J.; Bennett, G.N.

1990-06-01

Coenzyme A (CoA)-transferase (acetoacetyl-CoA:acetate/butyrate:CoA-transferase (butyrate-acetoacetate CoA-transferase) (EC 2.8.3.9)) of Clostridium acetobutylicum ATCC 824 is an important enzyme in the metabolic shift between the acid-producing and solvent-forming states of this organism. The genes encoding the two subunits of this enzyme have been cloned and subsequent subcloning experiments established the position of the structural genes for CoA-transferase. Complementation of Escherichia coli ato mutants with the recombinant plasmid pCoAT4 (pUC19 carrying a 1.8-kilobase insert of C. acetobutylicum DNA encoding CoA-transferase activity) enabled the transformants to grow on butyrate as a sole carbon source. Despite the ability of CoA-transferase to complement the ato defectmore » in E. coli mutants, Southern blot and Western blot (immunoblot) analyses showed showed that neither the C. acetobutylicum genes encoding CoA-transferase nor the enzyme itself shared any apparent homology with its E. coli counterpart. Polypeptides of M{sub r} of the purified CoA-transferase subunits were observed by Western blot and maxicell analysis of whole-cell extracts of E.coli harboring pCoAT4. The proximity and orientation of the genes suggest that the genes encoding the two subunits of CoA-transferase may form an operon similar to that found in E. coli. In the plasmid, however, transcription appears to be primarily from the lac promoter of the vector.« less

"Nous" versus "on": Pronouns with First-Person Plural Reference in Synchronous French Chat

ERIC Educational Resources Information Center

van Compernolle, Remi A.

2008-01-01

This article explores variation in the use of the pronouns "nous" and "on" for first-person plural reference in a substantial corpus of French-language Internet chat discourse. The results indicate that "on" is nearly categorically preferred to "nous," which is in line with previous research on informal spoken French. A qualitative analysis of…

An MRM-based workflow for absolute quantitation of lysine-acetylated metabolic enzymes in mouse liver.

PubMed

Xu, Leilei; Wang, Fang; Xu, Ying; Wang, Yi; Zhang, Cuiping; Qin, Xue; Yu, Hongxiu; Yang, Pengyuan

2015-12-07

As a key post-translational modification mechanism, protein acetylation plays critical roles in regulating and/or coordinating cell metabolism. Acetylation is a prevalent modification process in enzymes. Protein acetylation modification occurs in sub-stoichiometric amounts; therefore extracting biologically meaningful information from these acetylation sites requires an adaptable, sensitive, specific, and robust method for their quantification. In this work, we combine immunoassays and multiple reaction monitoring-mass spectrometry (MRM-MS) technology to develop an absolute quantification for acetylation modification. With this hybrid method, we quantified the acetylation level of metabolic enzymes, which could demonstrate the regulatory mechanisms of the studied enzymes. The development of this quantitative workflow is a pivotal step for advancing our knowledge and understanding of the regulatory effects of protein acetylation in physiology and pathophysiology.

Inhibition of Histone Acetylation by ANP32A Induces Memory Deficits.

PubMed

Chai, Gao-Shang; Feng, Qiong; Ma, Rong-Hong; Qian, Xiao-Hang; Luo, Dan-Ju; Wang, Zhi-Hao; Hu, Yu; Sun, Dong-Sheng; Zhang, Jun-Fei; Li, Xiao; Li, Xiao-Guang; Ke, Dan; Wang, Jian-Zhi; Yang, Xi-Fei; Liu, Gong-Ping

2018-01-01

There is accumulating evidence that decreased histone acetylation is involved in normal aging and neurodegenerative diseases. Recently, we found that ANP32A, a key component of INHAT (inhibitor of acetyltransferases) that suppresses histone acetylation, increased in aged and cognitively impaired C57 mice and expressing wild-type human full length tau (htau) transgenic mice. Downregulating ANP32A restored cognitive function and synaptic plasticity through upregulation of the expressions of synaptic-related proteins via increasing histone acetylation. However, there is no direct evidence that ANP32A can induce neurodegeneration and memory deficits. In the present study, we overexpressed ANP32A in the hippocampal CA3 region of C57 mice and found that ANP32A overexpression induced cognitive abilities and synaptic plasticity deficits, with decreased synaptic-related protein expression and histone acetylation. Combined with our recent studies, our findings reveal that upregulated ANP32A induced-suppressing histone acetylation may underlie the cognitive decline in neurodegenerative disease, and suppression of ANP32A may represent a promising therapeutic approach for neurodegenerative diseases including Alzheimer's disease.

[Effect of acetylation and oxidation on some properties of breadfruit (Artocarpus altilis) seed starch].

PubMed

Rincón, Alicia Mariela; Bou Rached, Lizet; Aragoza, Luis E; Padilla, Fanny

2007-09-01

Starch extracted from seeds of Artocarpus altilis (Breadfruit) was chemically modified by acetylation and oxidation, and its functional properties were evaluated and compared with these of native starch. Analysis of the chemical composition showed that moisture content was higher for modified starches. Ash, protein, crude fiber and amylose contents were reduced by the modifications, but did not alter the native starch granules' irregularity, oval shape and smooth surface. Acetylation produced changes in water absorption, swelling power and soluble solids, these values were higher for acetylated starch, while values for native and oxidized starches were similar. Both modifications reduced pasting temperature; oxidation reduced maximum peak viscosity but it was increased by acetylation. Hot paste viscosity was reduced by both modifications, whereas cold paste viscosity was lower in the oxidized starch and higher in the acetylated starch. Breakdown was increased by acetylation and reduced with oxidation. Setback value was reduced after acetylation, indicating it could minimize retrogradation of the starch.

Genetic incorporation of Nε-acetyllysine reveals a novel acetylation-sumoylation switch in yeast.

PubMed

Kim, Sang-Woo; Lee, Kyung Jin; Kim, Sinil; Kim, Jihyo; Cho, Kyukwang; Ro, Hyeon-Su; Park, Hee-Sung

2017-11-01

The lysine acetylation of proteins plays a key role in regulating protein functions, thereby controlling a wide range of cellular processes. Despite the prevalence and significance of lysine acetylation in eukaryotes, however, its systematic study has been challenged by the technical limitations of conventional approaches for selective lysine acetylation in vivo. Here, we report the in vivo study of lysine acetylation via the genetic incorporation of N ε -acetyllysine in yeast. We demonstrate that a newly discovered acetylation-sumoylation switch precisely controls the localization and cellular function of the yeast septin protein, Cdc11, during the cell cycle. This approach should facilitate the comprehensive in vivo study of lysine acetylation across a wide range of proteins in eukaryotic organisms. This article is part of a Special Issue entitled "Biochemistry of Synthetic Biology - Recent Developments" Guest Editor: Dr. Ilka Heinemann and Dr. Patrick O'Donoghue. Copyright © 2017 Elsevier B.V. All rights reserved.

Does non-acetylated salicylate inhibit thromboxane biosynthesis in human platelets?

PubMed

Danesh, B J; McLaren, M; Russell, R I; Lowe, G D; Forbes, C D

1988-08-01

Ingestion of aspirin (acetyl salicylic acid: ASA) may promote bleeding complications due to inhibition of thromboxane biosynthesis, which results in the prolongation of bleeding time. The effect is believed to be achieved by the irreversible acetylation of the enzyme cyclooxygenase by aspirin. This alteration in platelet function by aspirin prohibits its use in patients with bleeding disorders such as haemophiliacs. Choline magnesium trisalicylate (CMT; Napp Laboratories Ltd) is a non-acetylated salicylate with analgesic and anti-inflammatory effects similar to that of aspirin. However, despite a comparable salicylate absorption from the two drugs, CMT is found to have no inhibitory action in platelet aggregation and to cause less gastric mucosal damage and gastrointestinal blood loss than aspirin. To investigate the role of the acetyl moiety in the inhibition of platelet thromboxane biosynthesis, we studied the effect of CMT and ASA on bleeding time, serum thromboxane B2 (TxB2) and thromboxane (Tx) generation in healthy volunteers.

Experience in the United States with public deliberation about health insurance benefits using the small group decision exercise, CHAT.

PubMed

Danis, Marion; Ginsburg, Marjorie; Goold, Susan

2010-01-01

"Choosing Healthplans All Together" (CHAT) is a small group decision exercise designed to give the public a voice in priority setting in the face of unsustainable health care costs. It has been used for research, policy, and teaching purposes. Departments of insurance in various states in the United States have used CHAT to determine public opinion about what should be included in basic health insurance packages for the uninsured. Some municipalities have used it to assess public priorities for direct service delivery to the uninsured. Setting up the exercise requires substantial preparation, but the public finds it simple to use and understand.

Integration of Three CBI Models and WeChat Mobile Learning in Business English Teaching

ERIC Educational Resources Information Center

Siqi, Che

2017-01-01

Content-Based Instruction (CBI) is considered effective not only in mastering language skills, but also in acquiring the content knowledge of business subjects. WeChat, a popular communicative and interactive platform, is acknowledged as a new instrument to improve verbal teaching proficiency and obtain relevant information. The integration of…

The efficacy of interviewing young drug users through online chat.

PubMed

Barratt, Monica J

2012-06-01

Despite the fact that most young people who use 'party drugs' also use the Internet, accounts of drugs research involving qualitative interviewing using real-time instant messaging or online chat are yet to be published. This paper assesses the efficacy of conducting qualitative research interviews with young party drug users through instant messaging. In 2007-2008, 837 Australian residents who reported recent use of psychostimulants and/or hallucinogens and participated in online drug discussion completed a web survey and a subsample of 27 completed online interviews (median age 21, range 17-37, 59% male). Experienced drug users were more likely to volunteer to be interviewed than novices. The time and space flexibility provided by the online interviews was convenient; however, interviews were more prone to interruption. Establishing legitimacy, personal disclosure, appropriate linguistic style and humour facilitated the development of rapport and enabled the production of more detailed and in-depth data. These strategies were not successful in all cases and when unsuccessful, interviewees were more easily able to exit the interview by choosing not to respond. Young drug users already using the Internet to chat about drugs find online interviewing an acceptable and convenient way to contribute to research. With adequate preparation to develop technical and cultural competencies, online interviewing offers an effective way of engaging with young people that is worthy of consideration by researchers in the alcohol and other drug field. © 2011 Australasian Professional Society on Alcohol and other Drugs.

Innervation pattern of the preocular human central retinal artery.

PubMed

Bergua, Antonio; Kapsreiter, Markus; Neuhuber, Winfried L; Reitsamer, Herbert A; Schrödl, Falk

2013-05-01

The central retinal artery (CRA) is the main vessel for inner retinal oxygen and nutrition supply. While the intraocular branches lack autonomic innervation, the innervation pattern of the extra-ocular part of this vessel along its course within the optic nerve is poorly investigated. This part however is essential for maintenance of retinal blood supply, in physiological and pathological conditions. Therefore, the aim of this study was the characterization of the autonomic innervation of the preocular CRA in humans with morphological methods. Meeting the Declaration of Helsinki, eyes of body or cornea donors were processed for single or double immunohistochemistry against tyrosine hydroxilase (TH), dopamine-β-hydroxylase (DBH), choline acetyl-transferase (ChAT), vesicular acetylcholine transporter (VAChT), neuronal nitric oxide synthase (nNOS), calcitonin gene-related peptide (CGRP), substance P (SP), vasoactive intestinal polypeptide (VIP), and cytochemistry for NADPH-diaphorase (NADPH-d). For documentation, light-, fluorescence-, and confocal laser-scanning microscopy were used. TH and DBH immunoreactive nerve fibres were detected in the CRA vessel wall, although a distinct perivascular plexus was missing. Further, nerve fibres immunoreactive for ChAT and VAChT were found, while CGRP, SP, and VIP were not detected. NADPH-d staining revealed scattered nerve fibres in the adventitia of the CRA and in close vicinity; however, nNOS-immunostaining could not confirm this finding. The CRA receives adrenergic and cholinergic innervations, indicating sympathetic and parasympathetic components, respectively. Remarkably, a peptidergic primary afferent innervation was missing. Since clinical results suggest an autoregulation of intraretinal vessels, further studies are needed to clarify the impact of CRA innervation for retinal perfusion. Copyright © 2012 Elsevier Ltd. All rights reserved.

Genetic heterogeneity among slow acetylator N-acetyltransferase 2 phenotypes in cryopreserved human hepatocytes.

PubMed

Doll, Mark A; Hein, David W

2017-07-01

Genetic polymorphisms in human N-acetyltransferase 2 (NAT2) modify the metabolism of numerous drugs and carcinogens. These genetic polymorphisms modify both drug efficacy and toxicity and cancer risk associated with carcinogen exposure. Previous studies have suggested phenotypic heterogeneity among different NAT2 slow acetylator genotypes. NAT2 phenotype was investigated in vitro and in situ in samples of human hepatocytes obtained from various NAT2 slow and intermediate NAT2 acetylator genotypes. NAT2 gene dose response (NAT2*5B/*5B > NAT2*5B/*6A > NAT2*6A/*6A) was observed towards the N-acetylation of the NAT2-specific drug sulfamethazine by human hepatocytes both in vitro and in situ. N-acetylation of 4-aminobiphenyl, an arylamine carcinogen substrate for both N-acetyltransferase 1 and NAT2, showed the same trend both in vitro and in situ although the differences were not significant (p > 0.05). The N-acetylation of the N-acetyltransferase 1-specific substrate p-aminobenzoic acid did not follow this trend. In comparisons of NAT2 intermediate acetylator genotypes, differences in N-acetylation between NAT2*4/*5B and NAT2*4/*6B hepatocytes were not observed in vitro or in situ towards any of these substrates. These results further support phenotypic heterogeneity among NAT2 slow acetylator genotypes, consistent with differential risks of drug failure or toxicity and cancer associated with carcinogen exposure.

Office Hours as You Like Them: Integrating Real-Time Chats into the Course Media Mix.

ERIC Educational Resources Information Center

McKeage, Kim

2001-01-01

Reports on one professor's use of integrated synchronous electronic office hours (i.e., a "chat room") with asynchronous course conferencing (i.e., email) in a class on introductory marketing. Describes its uses, limitations, benefits, potential problems, and results from a student survey. (EV)

Role of Histone Acetylation in the Assembly and Modulation of Chromatin Structures

PubMed Central

Annunziato, Anthony T.; Hansen, Jeffrey C.

2000-01-01

The acetylation of the core histone N-terminal “tail” domains is now recognized as a highly conserved mechanism for regulating chromatin functional states. The following article examines possible roles of acetylation in two critically important cellular processes: replication-coupled nucleosome assembly, and reversible transitions in chromatin higher order structure. After a description of the acetylation of newly synthesized histones, and of the likely acetyltransferases involved, an overview of histone octamer assembly is presented. Our current understanding of the factors thought to assemble chromatin in vivo is then described. Genetic and biochemical investigations of the function the histone tails, and their acetylation, in nucleosome assembly are detailed, followed by an analysis of the importance of histone deacetylation in the maturation of newly replicated chromatin. In the final section the involvement of the histone tail domains in chromatin higher order structures is addressed, along with the role of histone acetylation in chromatin folding. Suggestions for future research are offered in the concluding remarks. PMID:11097424

Prevalence of Autism Spectrum Phenomenology in Cornelia de Lange and Cri du Chat Syndromes

ERIC Educational Resources Information Center

Moss, Joanna F.; Oliver, Chris; Berg, Katy; Kaur, Gurmeash; Jephcott, Lesley; Cornish, Kim

2008-01-01

Autism spectrum disorder characteristics have not been evaluated in Cornelia de Lange and Cri du Chat syndromes using robust assessments. The Autism Diagnostic Observation Schedule and Social Communication Questionnaire were administered to 34 participants with Cornelia de Lange syndrome and a comparison group of 23 participants with Cri du Chat…

Targeting the GD3 acetylation pathway selectively induces apoptosis in glioblastoma

PubMed Central

Birks, Suzanne M.; Danquah, John Owusu; King, Linda; Vlasak, Reinhardt; Gorecki, Dariusz C.; Pilkington, Geoffrey J.

2011-01-01

The expression of ganglioside GD3, which plays crucial roles in normal brain development, decreases in adults but is upregulated in neoplastic cells, where it regulates tumor invasion and survival. Normally a buildup of GD3 induces apoptosis, but this does not occur in gliomas due to formation of 9-O-acetyl GD3 by the addition of an acetyl group to the terminal sialic acid of GD3; this renders GD3 unable to induce apoptosis. Using human biopsy-derived glioblastoma cell cultures, we have carried out a series of molecular manipulations targeting GD3 acetylation pathways. Using immunocytochemistry, flow cytometry, western blotting, and transwell assays, we have shown the existence of a critical ratio between GD3 and 9-O-acetyl GD3, which promotes tumor survival. Thus, we have demonstrated for the first time in primary glioblastoma that cleaving the acetyl group restores GD3, resulting in a reduction in tumor cell viability while normal astrocytes remain unaffected. Additionally, we have shown that glioblastoma viability is reduced due to the induction of mitochondrially mediated apoptosis and that this occurs after mitochondrial membrane depolarization. Three methods of cleaving the acetyl group using hemagglutinin esterase were investigated, and we have shown that the baculovirus vector transduces glioma cells as well as normal astroctyes with a relatively high efficacy. A recombinant baculovirus containing hemagglutinin esterase could be developed for the clinic as an adjuvant therapy for glioma. PMID:21807667

Acetylation of NDPK-D Regulates Its Subcellular Localization and Cell Survival

PubMed Central

Fujita, Yuki; Fujiwara, Kei; Zenitani, Shigetake; Yamashita, Toshihide

2015-01-01

Nucleoside diphosphate kinases (NDPK) are ubiquitous enzymes that catalyze the reversible phosphotransfer of γ-phosphates between di- and triphosphonucleosides. NDPK-D (Nm23-H4) is the only member of the NDPK family with a mitochondrial targeting sequence. Despite the high expression of NDPK-D in the developing central nervous system, its function remains to be determined. In this study, we show that NDPK-D knockdown induces apoptosis in neuroblastoma cells as well as in mouse cortex, suggesting that NDPK-D is required for neuronal survival. We identified NDPK-D as a binding partner of NAD+-dependent histone deacetylase, SIRT1, by yeast two-hybrid screening. NDPK-D co-localized with SIRT1, and the association of these molecules was confirmed by co-immunoprecipitation. Inhibition of SIRT1 increases the acetylation of NDPK-D. Overexpression of NDPK-D along with SIRT1, or mutation in the acetylated lysine residues in NDPK-D, increases its nuclear accumulation. Furthermore, the NDPK-D acetylation-mimic mutant increased apoptosis in N1E-115 cells. Our data demonstrate that acetylation regulates the shuttling of NDPK-D between nucleus and cytoplasm, and increased acetylation of NDPK-D causes apoptosis. PMID:26426123

Effects of resveratrol, oxyresveratrol, and their acetylated derivatives on cellular melanogenesis.

PubMed

Park, Jiaa; Park, Joon Heum; Suh, Hwa-Jin; Lee, In Chul; Koh, Jaesook; Boo, Yong Chool

2014-07-01

Resveratrol and oxyresveratrol are naturally occurring phenolic compounds with various bioactivities, but their uses in cosmetics have been partly limited by their chemical instabilities. This study was performed to examine the anti-melanogenic effects of the acetylated derivatives from resveratrol and oxyresveratrol. Resveratrol and oxyresveratrol were chemically modified to triacetyl resveratrol and tetraacetyl oxyresveratrol, respectively. The acetylated compounds were less susceptible than the parent compounds to oxidative discoloration. The acetylated compounds inhibited the activities of tyrosinases less than parent compounds in vitro, but they were as effective at cellular melanogenesis inhibition, indicating bioconversion to parent compounds inside cells. Supporting this notion, the parent compounds were regenerated when the acetylated compounds were digested with cell lysates. Although resveratrol and triacetyl resveratrol inhibited tyrosinase activity less effectively than oxyresveratrol and tetraacetyl oxyresveratrol in vitro, they inhibited cellular melanogenesis more effectively. This discrepancy was explained by strong inhibition of tyrosinase expression by resveratrol and triacetyl resveratrol. Experiments using a reconstituted skin model indicated that resveratrol derivatives can affect melanin synthesis and cell viability to different extents. Collectively, this study suggests that acetylated derivatives of resveratrol have great potential as anti-melanogenic agents for cosmetic use in terms of efficacy, safety, and stability.

Streamflow, Water Quality, and Metal Loads from Chat Leachate and Mine Outflow into Tar Creek, Ottawa County, Oklahoma, 2005

USGS Publications Warehouse

Cope, Caleb C.; Becker, Mark F.; Andrews, William J.; DeHay, Kelli

2008-01-01

Picher mining district is an abandoned lead and zinc mining area located in Ottawa County, northeastern Oklahoma. During the first half of the 20th century, the area was a primary producer of lead and zinc in the United States. Large accumulations of mine tailings, locally referred to as chat, produce leachate containing cadmium, iron, lead, and zinc that enter drainages within the mining area. Metals also seep to local ground water and streams from unplugged shafts, vent holes, seeps, and abandoned mine dewatering wells. Streamflow measurements were made and water-quality samples were collected and analyzed from two locations in Picher mining district from August 16 to August 29 following a rain event beginning on August 14, 2005, to determine likely concentrations and loads of metals from tailings and mine outflows in the part of Picher mining district near Tar Creek. Locations selected for sampling included a tailings pile with an adjacent mill pond, referred to as the Western location, and a segment of Tar Creek from above the confluence with Lytle Creek to below Douthat bridge, referred to as Tar Creek Study Segment. Measured streamflow was less than 0.01 cubic foot per second at the Western location, with streamflow only being measurable at that site on August 16, 2005. Measured streamflows ranged from <0.01 to 2.62 cubic feet per second at Tar Creek Study Segment. One water-quality sample was collected from runoff at the Western location. Total metals concentrations in that sample were 95.3 micrograms per liter cadmium, 182 micrograms per liter iron, 170 micrograms per liter lead, 1,760 micrograms per liter zinc. Total mean metals concentrations in 29 water-quality samples collected from Tar Creek Study Segment from August 16-29, 2005, were 21.8 micrograms per liter cadmium, 7,924 micrograms per liter iron, 7.68 micrograms per liter lead, and 14,548 micrograms per liter zinc. No metals loading values were calculated for the Western location. Metals loading

Arylamine N-acetyltransferase 2 genotype-dependent N-acetylation of isoniazid in cryopreserved human hepatocytes.

PubMed

Doll, Mark A; Salazar-González, Raúl A; Bodduluri, Srineil; Hein, David W

2017-07-01

Cryopreserved human hepatocytes were used to investigate the role of arylamine N -acetyltransferase 2 (NAT2; EC 2.3.1.5) polymorphism on the N -acetylation of isoniazid (INH). NAT2 genotype was determined by Taqman allelic discrimination assay and INH N -acetylation was measured by high performance liquid chromatography. INH N -acetylation rates in vitro exhibited a robust and highly significant ( P <0.005) NAT2 phenotype-dependent metabolism. N -acetylation rates in situ were INH concentration- and time-dependent. Following incubation for 24 h with 12.5 or 100 µmol/L INH, acetyl-INH concentrations varied significantly ( P = 0.0023 and P = 0.0002) across cryopreserved human hepatocytes samples from rapid, intermediate, and slow acetylators, respectively. The clear association between NAT2 genotype and phenotype supports use of NAT2 genotype to guide INH dosing strategies in the treatment and prevention of tuberculosis.

Acetylation of spermidine and methylglyoxal bis(guanylhydrazone) in baby-hamster kidney cells (BHK-21/C13).

PubMed Central

Wallace, H M; Nuttall, M E; Robinson, F C

1988-01-01

Treatment of BHK-21/C13 cells with methylglyoxal bis(guanylhydrazone) (MGBG) induced the cytosolic form of spermidine N1-acetyltransferase. It stabilized the enzyme against proteolytic degradation, but the drug did not affect the enzyme activity in vitro. MGBG was itself acetylated by BHK-21/C13 cells, but at only one-tenth the rate at which spermidine was acetylated. Acetylation occurred almost exclusively in the nuclear fraction. The product was identified as N-acetyl-MGBG by h.p.l.c., by using [3H]acetyl-CoA and [14C]MGBG as co-substrates. The results suggest that the acetylation of MGBG by BHK-21/C13 cells occurs by a different acetyltransferase enzyme from that which acetylates spermidine. PMID:3421945

Acetylated microtubules are required for fusion of autophagosomes with lysosomes.

PubMed

Xie, Rui; Nguyen, Susan; McKeehan, Wallace L; Liu, Leyuan

2010-11-22

Autophagy is a dynamic process during which isolation membranes package substrates to form autophagosomes that are fused with lysosomes to form autolysosomes for degradation. Although it is agreed that the LC3II-associated mature autophagosomes move along microtubular tracks, it is still in dispute if the conversion of LC3I to LC3II before autophagosomes are fully mature and subsequent fusion of mature autophagosomes with lysosomes require microtubules. We use biochemical markers of autophagy and a collection of microtubule interfering reagents to test the question. Results show that interruption of microtubules with either microtubule stabilizing paclitaxel or destabilizing nocodazole similarly impairs the conversion of LC3I to LC3II, but does not block the degradation of LC3II-associated autophagosomes. Acetylation of microtubules renders them resistant to nocodazole treatment. Treatment with vinblastine that causes depolymerization of both non-acetylated and acetylated microtubules results in impairment of both LC3I-LC3II conversion and LC3II-associated autophagosome fusion with lysosomes. Acetylated microtubules are required for fusion of autophagosomes with lysosomes to form autolysosomes.

Lysine Ubiquitination and Acetylation of Human Cardiac 20S Proteasomes

PubMed Central

Lau, Edward; Choi, Howard JH; Ng, Dominic CM; Meyer, David; Fang, Caiyun; Li, Haomin; Wang, Ding; Zelaya, Ivette M; Yates, John R; Lam, Maggie PY

2016-01-01

Purpose Altered proteasome functions are associated with multiple cardiomyopathies. While the proteasome targets poly-ubiquitinated proteins for destruction, it itself is modifiable by ubiquitination. We aim to identify the exact ubiquitination sites on cardiac proteasomes and examine whether they are also subject to acetylations. Experimental design Assembled cardiac 20S proteasome complexes were purified from five human hearts with ischemic cardiomyopathy, then analyzed by high-resolution MS to identify ubiquitination and acetylation sites. We developed a library search strategy that may be used to complement database search in identifying PTM in different samples. Results We identified 63 ubiquitinated lysines from intact human cardiac 20S proteasomes. In parallel, 65 acetylated residues were also discovered, 39 of which shared with ubiquitination sites. Conclusion and clinical relevance This is the most comprehensive characterization of cardiac proteasome ubiquitination to-date. There are significant overlaps between the discovered ubiquitination and acetylation sites, permitting potential crosstalk in regulating proteasome functions. The information presented here will aid future therapeutic strategies aimed at regulating the functions of cardiac proteasomes. PMID:24957502

Lysine ubiquitination and acetylation of human cardiac 20S proteasomes.

PubMed

Zong, Nobel; Ping, Peipei; Lau, Edward; Choi, Howard Jh; Ng, Dominic Cm; Meyer, David; Fang, Caiyun; Li, Haomin; Wang, Ding; Zelaya, Ivette M; Yates, John R; Lam, Maggie Py

2014-08-01

Altered proteasome functions are associated with multiple cardiomyopathies. While the proteasome targets polyubiquitinated proteins for destruction, it itself is modifiable by ubiquitination. We aim to identify the exact ubiquitination sites on cardiac proteasomes and examine whether they are also subject to acetylations. Assembled cardiac 20S proteasome complexes were purified from five human hearts with ischemic cardiomyopathy, then analyzed by high-resolution MS to identify ubiquitination and acetylation sites. We developed a library search strategy that may be used to complement database search in identifying PTM in different samples. We identified 63 ubiquitinated lysines from intact human cardiac 20S proteasomes. In parallel, 65 acetylated residues were also discovered, 39 of which shared with ubiquitination sites. This is the most comprehensive characterization of cardiac proteasome ubiquitination to date. There are significant overlaps between the discovered ubiquitination and acetylation sites, permitting potential crosstalk in regulating proteasome functions. The information presented here will aid future therapeutic strategies aimed at regulating the functions of cardiac proteasomes. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of gamma irradiation on physicochemical properties of native and acetylated wheat starches.

PubMed

Kong, Xiangli; Zhou, Xin; Sui, Zhongquan; Bao, Jinsong

2016-10-01

Effects of gamma irradiation on the physicochemical and crystalline properties of the native and acetylated wheat starches were investigated. Peak, hot paste, cool paste and setback viscosities of both native and acetylated wheat starches decreased continuously and significantly with the increase of the irradiation dose, whereas breakdown viscosity increased after irradiation. However, gamma irradiation only exerted slight effects on thermal and retrogradation properties of both native and acetylated wheat starches. X-ray diffraction and fourier transform infrared spectroscopy revealed that acetylation modification had considerable effects on the molecular structure of wheat starch, and the crystallinity of both untreated and acetylated starches increased slightly with the increase of irradiation dose. However, the V-type crystallinity of amylose-lipid complex was not affected by gamma irradiation treatments with doses up to 9kGy. Copyright © 2016 Elsevier B.V. All rights reserved.

Reaction of rat liver glutathione S-transferases and bacterial dichloromethane dehalogenase with dihalomethanes.

PubMed

Blocki, F A; Logan, M S; Baoli, C; Wackett, L P

1994-03-25

Dichloromethane dehalogenase from Methylophilus sp. DM11 is a glutathione S-transferase homolog that is specifically active with dihalomethane substrates. This bacterial enzyme and rat liver glutathione S-transferases were purified to investigate their relative reactivity with CH2Cl2 and related substrates. Rat liver alpha class glutathione transferases were inactive and mu class enzymes showed low activity (7-23 nmol/min/mg of protein) with CH2Cl2. theta class glutathione transferase 5-5 from rat liver and Methylophilus sp. dichloromethane dehalogenase showed specific activities of > or = 1 mumol/min/mg of protein. Apparent Kcat/Km were determined to be 3.3 x 10(4) and 6.0 x 10(4) L M-1 S-1 for the two enzymes, respectively. Dideutero-dichloromethane was processed to dideutereo-formaldehyde, consistent with a nucleophilic halide displacement mechanism. The possibility of a GSCH2X reaction intermediate (GS, glutathione; X, halide) was probed using CH2ClF to generate a more stable halomethylglutathione species (GSCH2F). The reaction of CH2ClF with dichloromethane dehalogenase produced a kinetically identifiable intermediate that decomposed to formaldehyde at a similar rate to synthetic HOCH2CH2SCH2F. 19F-NMR revealed the transient formation of an intermediate identified as GSCH2F by its chemical shift, its triplet resonance, and H-F coupling constant consistent with a fluoromethylthioether. Its decomposition was matched by a stoichiometric formation of fluoride. These studies indicated that the bacterial dichloromethane dehalogenase directs a nucleophilic attack of glutathione on CH2Cl2 to produce a halomethylthioether intermediate. This focuses attention on the mechanism used by theta class glutathione transferases to generate a halomethylthioeter from relatively unreactive dihalomethanes.

Acetylation mediates Cx43 reduction caused by electrical stimulation

PubMed Central

Meraviglia, Viviana; Azzimato, Valerio; Colussi, Claudia; Florio, Maria Cristina; Binda, Anna; Panariti, Alice; Qanud, Khaled; Suffredini, Silvia; Gennaccaro, Laura; Miragoli, Michele; Barbuti, Andrea; Lampe, Paul D.; Gaetano, Carlo; Pramstaller, Peter P.; Capogrossi, Maurizio C.; Recchia, Fabio A.; Pompilio, Giulio; Rivolta, Ilaria; Rossini, Alessandra

2015-01-01

Communication between cardiomyocytes depends upon Gap Junctions (GJ). Previous studies have demonstrated that electrical stimulation induces GJ remodeling and modifies histone acetylases (HAT) and deacetylases (HDAC) activities, although these two results have not been linked. The aim of this work was to establish whether electrical stimulation modulates GJ-mediated cardiac cell-cell communication by acetylation-dependent mechanisms. Field stimulation of HL-1 cardiomyocytes at 0.5 Hz for 24 hours significantly reduced Connexin43 (Cx43) expression and cell-cell communication. HDAC activity was down-regulated whereas HAT activity was not modified resulting in increased acetylation of Cx43. Consistent with a post-translational mechanism, we did not observe a reduction in Cx43 mRNA in electrically stimulated cells, while the proteasomal inhibitor MG132 maintained Cx43 expression. Further, the treatment of paced cells with the HAT inhibitor Anacardic Acid maintained both the levels of Cx43 and cell-cell communication. Finally, we observed increased acetylation of Cx43 in the left ventricles of dogs subjected to chronic tachypacing as a model of abnormal ventricular activation. In conclusion, our findings suggest that altered electrical activity can regulate cardiomyocyte communication by influencing the acetylation status of Cx43. PMID:26264759

Computational Prediction of Protein Epsilon Lysine Acetylation Sites Based on a Feature Selection Method.

PubMed

Gao, JianZhao; Tao, Xue-Wen; Zhao, Jia; Feng, Yuan-Ming; Cai, Yu-Dong; Zhang, Ning

2017-01-01

Lysine acetylation, as one type of post-translational modifications (PTM), plays key roles in cellular regulations and can be involved in a variety of human diseases. However, it is often high-cost and time-consuming to use traditional experimental approaches to identify the lysine acetylation sites. Therefore, effective computational methods should be developed to predict the acetylation sites. In this study, we developed a position-specific method for epsilon lysine acetylation site prediction. Sequences of acetylated proteins were retrieved from the UniProt database. Various kinds of features such as position specific scoring matrix (PSSM), amino acid factors (AAF), and disorders were incorporated. A feature selection method based on mRMR (Maximum Relevance Minimum Redundancy) and IFS (Incremental Feature Selection) was employed. Finally, 319 optimal features were selected from total 541 features. Using the 319 optimal features to encode peptides, a predictor was constructed based on dagging. As a result, an accuracy of 69.56% with MCC of 0.2792 was achieved. We analyzed the optimal features, which suggested some important factors determining the lysine acetylation sites. We developed a position-specific method for epsilon lysine acetylation site prediction. A set of optimal features was selected. Analysis of the optimal features provided insights into the mechanism of lysine acetylation sites, providing guidance of experimental validation. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Cadmium inhibits lysine acetylation and succinylation inducing testicular injury of mouse during development.

PubMed

Yang, Qiangzhen; Li, Peifei; Wen, Yi; Li, Sisi; Chen, Jun; Liu, Xurui; Wang, Lirui; Li, Xinhong

2018-07-01

The toxic effects of cadmium (Cd) in the reproductive system have been confirmed, and lysine acetylation and succinylation play important roles in spermatogenesis. However, little attention determined whether Cd could affect lysine acylation and how it might have an impact on the reproductive system. Therefore, with the goal of contributing to this subject, we have examined the effects of Cd on lysine acetylation and succinylation of proteins in the germ cells of male mice testes during different developmental stages. We adopted intraperitoneal injection of cadmium chloride (1.2 mg/kg body weight) in mice once every 5 days from postnatal day 5-60. The results showed that Cd could restrict GAPDH activity, ATP and cAMP levels of germ cells to inhibit lysine acetylation and succinylation in the testes, inducing reproductive injuries. Cd also restricts acetylation of histone H4K5 and H4K12, which could result in failure of spermiogenesis. Remarkably, polarized acetylation occurs in meiosis, and high-level acetylation occurs earlier than high-level succinylation during spermatogenesis. Moreover, Cd has a limited effect on body weight but reduces the weight of the testis and litter size. Our research may provide a new way to reveal the mechanisms of Cd reproductive toxicity related to lysine acetylation and succinylation. Copyright © 2018. Published by Elsevier B.V.

Evolution of a Histone H4-K16 Acetyl-Specific DNA Aptamer

PubMed Central

Williams, Berea A. R.; Lin, Liyun; Lindsay, Stuart M.; Chaput, John C.

2009-01-01

We report the in vitro selection of DNA aptamers that bind to histone H4 proteins acetylated at lysine 16. The best aptamer identified in this selection binds to the target protein with a Kd of 21 nM, and discriminates against both the non-acetylated protein and histone H4 proteins acetylated at lysine 8. Comparative binding assays performed with a chip-quality antibody reveal that this aptamer binds to the acetylated histone target with similar affinity to a commercial antibody, but shows significantly greater specificity (15-fold versus 2,400-fold) for the target molecule. This result demonstrates that aptamers that are both modification and location specific can be generated to bind specific protein post-translational modifications. PMID:19385619

Production of Nα-acetylated thymosin α1 in Escherichia coli

PubMed Central

2011-01-01

Background Thymosin α1 (Tα1), a 28-amino acid Nα-acetylated peptide, has a powerful general immunostimulating activity. Although biosynthesis is an attractive means of large-scale manufacture, to date, Tα1 can only be chemosynthesized because of two obstacles to its biosynthesis: the difficulties in expressing small peptides and obtaining Nα-acetylation. In this study, we describe a novel production process for Nα-acetylated Tα1 in Escherichia coli. Results To obtain recombinant Nα-acetylated Tα1 efficiently, a fusion protein, Tα1-Intein, was constructed, in which Tα1 was fused to the N-terminus of the smallest mini-intein, Spl DnaX (136 amino acids long, from Spirulina platensis), and a His tag was added at the C-terminus. Because Tα1 was placed at the N-terminus of the Tα1-Intein fusion protein, Tα1 could be fully acetylated when the Tα1-Intein fusion protein was co-expressed with RimJ (a known prokaryotic Nα-acetyltransferase) in Escherichia coli. After purification by Ni-Sepharose affinity chromatography, the Tα1-Intein fusion protein was induced by the thiols β-mercaptoethanol or d,l-dithiothreitol, or by increasing the temperature, to release Tα1 through intein-mediated N-terminal cleavage. Under the optimal conditions, more than 90% of the Tα1-Intein fusion protein was thiolyzed, and 24.5 mg Tα1 was obtained from 1 L of culture media. The purity was 98% after a series of chromatographic purification steps. The molecular weight of recombinant Tα1 was determined to be 3107.44 Da by mass spectrometry, which was nearly identical to that of the synthetic version (3107.42 Da). The whole sequence of recombinant Tα1 was identified by tandem mass spectrometry and its N-terminal serine residue was shown to be acetylated. Conclusions The present data demonstrate that Nα-acetylated Tα1 can be efficiently produced in recombinant E. coli. This bioprocess could be used as an alternative to chemosynthesis for the production of Tα1. The described

What Are Youth Asking about Drugs? A Report of NIDA Drug Facts Chat Day

ERIC Educational Resources Information Center

Morton, Cory M.; Hoefinger, Heidi; Linn-Walton, Rebecca; Aikins, Ross; Falkin, Gregory P.

2015-01-01

The current study analyzes a sample of questions about drugs asked online by youth who participated in the National Institute on Drug Abuse's (NIDA) "Drug Facts Chat Day." The types of drugs youth asked about were coded into 17 substance categories, and the topics they raised were coded into seven thematic categories. The top five…

Parent-Endorsed Sex Differences in Toddlers with and without ASD: Utilizing the M-CHAT

ERIC Educational Resources Information Center

Øien, Roald A.; Hart, Logan; Schjølberg, Synnve; Wall, Carla A.; Kim, Elizabeth S.; Nordahl-Hansen, Anders; Eisemann, Martin R.; Chawarska, Katarzyna; Volkmar, Fred R.; Shic, Frederick

2017-01-01

Sex differences in typical development can provide context for understanding ASD. Baron-Cohen ("Trends Cogn Sci" 6(6):248-254, 2002) suggested ASD could be considered an extreme expression of normal male, compared to female, phenotypic profiles. In this paper, sex-specific M-CHAT scores from N = 53,728 18-month-old toddlers, including n…

Characterization of Affinity-Purified Isoforms of Acinetobacter calcoaceticus Y1 Glutathione Transferases

PubMed Central

Chee, Chin-Soon; Tan, Irene Kit-Ping; Alias, Zazali

2014-01-01

Glutathione transferases (GST) were purified from locally isolated bacteria, Acinetobacter calcoaceticus Y1, by glutathione-affinity chromatography and anion exchange, and their substrate specificities were investigated. SDS-polyacrylamide gel electrophoresis revealed that the purified GST resolved into a single band with a molecular weight (MW) of 23 kDa. 2-dimensional (2-D) gel electrophoresis showed the presence of two isoforms, GST1 (pI 4.5) and GST2 (pI 6.2) with identical MW. GST1 was reactive towards ethacrynic acid, hydrogen peroxide, 1-chloro-2,4-dinitrobenzene, and trans,trans-hepta-2,4-dienal while GST2 was active towards all substrates except hydrogen peroxide. This demonstrated that GST1 possessed peroxidase activity which was absent in GST2. This study also showed that only GST2 was able to conjugate GSH to isoproturon, a herbicide. GST1 and GST2 were suggested to be similar to F0KLY9 (putative glutathione S-transferase) and F0KKB0 (glutathione S-transferase III) of Acinetobacter calcoaceticus strain PHEA-2, respectively. PMID:24892084

Glutathione S - transferases class Pi and Mi and their significance in oncology.

PubMed

Marchewka, Zofia; Piwowar, Agnieszka; Ruzik, Sylwia; Długosz, Anna

2017-06-19

In this article the current data, which shows that glutathione S-transferases (GST) class Pi and Mi are interesting and promising biomarkers in acute and chronic inflammatory processes as well as in the oncology, were presented based on the review of the latest experimental and clinical studies. The article shows their characteristics, functions and participation (direct - GST Pi, indirect - GST Mi) in the regulation of signaling pathways of JNK kinases, which are involved in cell differentiation. Overexpression of glutathione S-transferases class Pi and Mi in many cancer cells plays a key role in cancer treatment, making them resistant to chemotherapy. GST isoenzymes are involved in the metabolism of various types of xenobiotics and endogenous substrates, so their altered expression in cancer tissues as well as in serum and urine could be an important potential marker of the cancer and an indicator of oxidative stress. The study shows the role of glutathione S-transferases in redox homeostasis of tumor cells and in the mechanism of resistance to anticancer drugs.

Mutations of Arabidopsis TBL32 and TBL33 affect xylan acetylation and secondary wall deposition

DOE PAGES

Yuan, Youxi; Teng, Quincy; Zhong, Ruiqin; ...

2016-01-08

Xylan is a major acetylated polymer in plant lignocellulosic biomass and it can be monoand di-acetylated at O-2 and O-3 as well as mono-acetylated at O-3 of xylosyl residues that is substituted with glucuronic acid (GlcA) at O-2. Based on the finding that ESK1, an Arabidopsis thaliana DUF231 protein, specifically mediates xylan 2-O- and 3-O-monoacetylation, we previously proposed that different acetyltransferase activities are required for regiospecific acetyl substitutions of xylan. Here, we demonstrate the functional roles of TBL32 and TBL33, two ESK1 close homologs, in acetyl substitutions of xylan. Simultaneous mutations of TBL32 and TBL33 resulted in a significant reductionmore » in xylan acetyl content and endoxylanase digestion of the mutant xylan released GlcA-substituted xylooligomers without acetyl groups. Structural analysis of xylan revealed that the tbl32 tbl33 mutant had a nearly complete loss of 3-O-acetylated, 2-O-GlcA-substituted xylosyl residues. A reduction in 3-Omonoacetylated and 2,3-di-O-acetylated xylosyl residues was also observed. Simultaneous mutations of TBL32, TBL33 and ESK1 resulted in a severe reduction in xylan acetyl level down to 15% of that of the wild type, and concomitantly, severely collapsed vessels and stunted plant growth. In particular, the S2 layer of secondary walls in xylem vessels of tbl33 esk1 and tbl32 tbl33 esk1 exhibited an altered structure, indicating abnormal assembly of secondary wall polymers. Furthermore, these results demonstrate that TBL32 and TBL33 play an important role in xylan acetylation and normal deposition of secondary walls.« less

Mutations of Arabidopsis TBL32 and TBL33 affect xylan acetylation and secondary wall deposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuan, Youxi; Teng, Quincy; Zhong, Ruiqin

Xylan is a major acetylated polymer in plant lignocellulosic biomass and it can be monoand di-acetylated at O-2 and O-3 as well as mono-acetylated at O-3 of xylosyl residues that is substituted with glucuronic acid (GlcA) at O-2. Based on the finding that ESK1, an Arabidopsis thaliana DUF231 protein, specifically mediates xylan 2-O- and 3-O-monoacetylation, we previously proposed that different acetyltransferase activities are required for regiospecific acetyl substitutions of xylan. Here, we demonstrate the functional roles of TBL32 and TBL33, two ESK1 close homologs, in acetyl substitutions of xylan. Simultaneous mutations of TBL32 and TBL33 resulted in a significant reductionmore » in xylan acetyl content and endoxylanase digestion of the mutant xylan released GlcA-substituted xylooligomers without acetyl groups. Structural analysis of xylan revealed that the tbl32 tbl33 mutant had a nearly complete loss of 3-O-acetylated, 2-O-GlcA-substituted xylosyl residues. A reduction in 3-Omonoacetylated and 2,3-di-O-acetylated xylosyl residues was also observed. Simultaneous mutations of TBL32, TBL33 and ESK1 resulted in a severe reduction in xylan acetyl level down to 15% of that of the wild type, and concomitantly, severely collapsed vessels and stunted plant growth. In particular, the S2 layer of secondary walls in xylem vessels of tbl33 esk1 and tbl32 tbl33 esk1 exhibited an altered structure, indicating abnormal assembly of secondary wall polymers. Furthermore, these results demonstrate that TBL32 and TBL33 play an important role in xylan acetylation and normal deposition of secondary walls.« less

N-acetyl Aspartate Levels in Adolescents With Bipolar and/or Cannabis Use Disorders

PubMed Central

Bitter, Samantha M.; Weber, Wade A.; Chu, Wen-Jang; Adler, Caleb M.; Eliassen, James C.; Strakowski, Stephen M.; DelBello, Melissa P.

2014-01-01

Objective Bipolar and cannabis use disorders commonly co-occur during adolescence, and neurochemical studies may help clarify the pathophysiology underlying this co-occurrence. This study compared metabolite concentrations in the left ventral lateral prefrontal cortex among: adolescents with bipolar disorder (bipolar group; n=14), adolescents with a cannabis use disorder (cannabis use group, n=13), adolescents with cannabis use and bipolar disorders (bipolar and cannabis group, n=25), and healthy adolescents (healthy controls, n=15). We hypothesized that adolescents with bipolar disorder (with or without cannabis use disorder) would have decreased N-acetyl aspartate levels in the ventral lateral prefrontal cortex compared to the other groups, and that the bipolar and cannabis group would have the lowest N-acetyl aspartate levels of all groups. Methods N-acetyl aspartate concentrations in the left ventral lateral prefrontal cortex were obtained using Proton Magnetic Resonance Spectroscopy. Results Adolescents with bipolar disorder showed significantly lower left ventral lateral prefrontal cortex N-acetyl aspartate levels, but post-hoc analyses indicated that this was primarily due to increased N-acetyl aspartate levels in the cannabis group. The cannabis use disorder group had significantly higher N-acetyl aspartate levels compared to the bipolar disorder and the bipolar and cannabis groups (p=0.0002 and p=0.0002, respectively). Pearson correlations revealed a significant positive correlation between amount of cannabis used and N-acetyl aspartate concentrations. Conclusions Adolescents with cannabis use disorder showed higher levels of N-acetyl aspartate concentrations that were significantly positively associated with the amount of cannabis used; however, this finding was not present in adolescents with comorbid bipolar disorder. PMID:24729763

Pulmonary fatty acid synthesis. I. Mitochondrial acetyl transfer by rat lung in vitro.

PubMed

Evans, R M; Scholz, R W

1977-04-01

Incorporation of tritiated water into fatty acids by rat adipose tissue and lung tissue slices incubated with 5 mM glucose indicated a level of fatty acid synthesis in rat lung approximately 15% that observed in adipose tissue in vitro. (-)-Hydroxycitrate, and inhibitor of ATP citrate lyase, markedly reduced tritiated water incorporation into fatty acids by lung tissue slices. The effects of (-)-hydroxycitrate and n-butymalonate on the incorporation of 14C-labeled glucose, pyruvate, acetate, and citrate suggested that citrate is a major acetyl carrier for de novo fatty acid synthesis in lung tissue. Alternative mechanisms to citrate as an acetyl carrier were also considered. Lung mitochondrial preparations formed significant levels of acetylcarnitine in the presence of pyruvate and carnitine. However, the effect of carnitine on the incorporation of 14C-labeled glucose, pyruvate, acetate, and citrate into fatty acids by lung tissue slices indicated that acetylcarnitine may not be a significant acetyl carrier for fatty acid synthesis but may serve as an acetyl "buffer" in the control of mitochondrial acetyl-CoA levels. Additionally, it appears unlikely that either acetylaspartate or acetoacetate are of major importance in acetyl transfer in lung tissue.

Crystal structure of tabtoxin resistance protein complexed with acetyl coenzyme A reveals the mechanism for beta-lactam acetylation.

PubMed

He, Hongzhen; Ding, Yi; Bartlam, Mark; Sun, Fei; Le, Yi; Qin, Xincheng; Tang, Hong; Zhang, Rongguang; Joachimiak, Andrzej; Liu, Jinyuan; Zhao, Nanming; Rao, Zihe

2003-01-31

Tabtoxin resistance protein (TTR) is an enzyme that renders tabtoxin-producing pathogens, such as Pseudomonas syringae, tolerant to their own phytotoxins. Here, we report the crystal structure of TTR complexed with its natural cofactor, acetyl coenzyme A (AcCoA), to 1.55A resolution. The binary complex forms a characteristic "V" shape for substrate binding and contains the four motifs conserved in the GCN5-related N-acetyltransferase (GNAT) superfamily, which also includes the histone acetyltransferases (HATs). A single-step mechanism is proposed to explain the function of three conserved residues, Glu92, Asp130 and Tyr141, in catalyzing the acetyl group transfer to its substrate. We also report that TTR possesses HAT activity and suggest an evolutionary relationship between TTR and other GNAT members.

A CHAT Approach of Light and Colors in Science Teaching for the Early Grades

ERIC Educational Resources Information Center

Kolokouri, Eleni; Plakitsi, Katerina

2016-01-01

This article describes a research study on the connection of Cultural Historical Activity Theory (CHAT) with Science Education in the early grades. The research study took place in the University of Ioannina, Greece with the support of the @fise research group. Within this frame, a narrative about light, colors and shadows was written as part of…

21 CFR 862.1315 - Galactose-1-phosphate uridyl transferase test system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... of the enzyme galactose-1-phosphate uridyl transferase in erythrocytes (red blood cells... hereditary disease galactosemia (disorder of galactose metabolism) in infants. (b) Classification. Class II. ...

Transport and metabolism of indole-3-acetyl-myo-inositol-galactoside in seedlings of Zea mays

NASA Technical Reports Server (NTRS)

Komoszynski, M.; Bandurski, R. S.

1986-01-01

Indole-3-acetyl-myo-inositol galactoside labeled with 3H in the indole and 14C in the galactose moieties was applied to kernels of 5 day old germinating seedlings of Zea mays. Indole-3-acetyl-myo-inositol galactoside was not transported into either the shoot or root tissue as the intact molecule but was instead hydrolyzed to yield [3H]indole-3-acetyl-myo-inositol and [3H]indole-3-acetic acid which were then transported to the shoot with little radioactivity going to the root. With certain assumption concerning the equilibration of applied [3H]indole-3-acetyl-myo-inositol-[U-14C]galactose with the endogenous pool, it may be concluded that indole-3-acetyl-myo-inositol galactoside in the endosperm supplies about 2 picomoles per plant per hour of indole-3-acetyl-myo-inositol and 1 picomole per plant per hour of indole-3-acetic acid to the shoot and thus is comparable to indole-3-acetyl-myo-inositol as a source of indole-acetic acid for the shoot. Quantitative estimates of the amount of galactose in the kernels suggest that [3H]indole-3-acetyl-myo-inositol-[14C]galactose is hydrolyzed after the compound leaves the endosperm but before it reaches the shoot. In addition, [3H]indole-3-acetyl-myo-inositol-[14C]galactose supplies appreciable amounts of 14C to the shoot and both 14C and 3H to an uncharacterized insoluble fraction of the endosperm.

Dan Goldin chats with First Lady Hillary Clinton

NASA Technical Reports Server (NTRS)

1999-01-01

At the Apollo/Saturn V Center, NASA Administrator Daniel Goldin (right) chats with First Lady Hillary Rodham Clinton and others while waiting for the launch of STS-93. Much attention has been generated over STS-93 due to Commander Eileen M. Collins, the first woman to serve as commander of a Shuttle mission. The primary payload of the five-day mission is the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected to unlock the secrets of supernovae, quasars and black holes. Liftoff of Space Shuttle Columbia is scheduled for 12:36 a.m. EDT July 20.

21 CFR 862.1315 - Galactose-1-phosphate uridyl transferase test system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1315 Galactose-1-phosphate uridyl transferase test system. (a) Identification...

21 CFR 862.1315 - Galactose-1-phosphate uridyl transferase test system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1315 Galactose-1-phosphate uridyl transferase test system. (a) Identification...

21 CFR 862.1535 - Ornithine carbamyl transferase test system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ornithine carbamyl transferase test system. 862.1535 Section 862.1535 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry...

Hello Harlie: Enabling Speech Monitoring Through Chat-Bot Conversations.

PubMed

Ireland, David; Atay, Christina; Liddle, Jacki; Bradford, Dana; Lee, Helen; Rushin, Olivia; Mullins, Thomas; Angus, Dan; Wiles, Janet; McBride, Simon; Vogel, Adam

2016-01-01

People with neurological conditions such as Parkinson's disease and dementia are known to have difficulties in language and communication. This paper presents initial testing of an artificial conversational agent, called Harlie. Harlie runs on a smartphone and is able to converse with the user on a variety of topics. A description of the application and a sample dialog are provided to illustrate the various roles chat-bots can play in the management of neurological conditions. Harlie can be used for measuring voice and communication outcomes during the daily life of the user, and for gaining information about challenges encountered. Moreover, it is anticipated that she may also have an educational and support role.

O-Acetyl location on cepacian, the principal exopolysaccharide of Burkholderia cepacia complex bacteria.

PubMed

Cescutti, Paola; Impallomeni, Giuseppe; Garozzo, Domenico; Rizzo, Roberto

2011-12-27

Cepacian is an exopolysaccharide produced by the majority of the isolates belonging to the Burkholderia cepacia complex bacteria, a group of 17 species, some of which infect cystic fibrosis patients, sometime with fatal outcome. The repeating unit of cepacian consists of a backbone having a trisaccharidic repeating unit with three side chains, as reported in the formula below. The exopolysaccharide is also acetylated, carrying from one to three acetyl esters per repeating unit, depending on the strain examined. The consequences of O-acetyl substitution in a polysaccharide are important both for its biological functions and for industrial applications, including the preparation of conjugated vaccines, since O-acetyl groups are important immunogenic determinants. The location of acetyl groups was achieved by NMR spectroscopy and ESI mass spectrometry and revealed that these substituents are scattered in non-stoichiometric ratio on many sugar residues in different positions, a feature which adds to the already unique carbohydrate structure of the polysaccharide. Copyright © 2011 Elsevier Ltd. All rights reserved.

Smartphone Application WeChat for Clinical Follow-up of Discharged Patients with Head and Neck Tumors: A Randomized Controlled Trial.

PubMed

Lyu, Ke-Xing; Zhao, Jing; Wang, Bin; Xiong, Guan-Xia; Yang, Wei-Qiang; Liu, Qi-Hong; Zhu, Xiao-Lin; Sun, Wei; Jiang, Ai-Yun; Wen, Wei-Ping; Lei, Wen-Bin

2016-12-05

Nowadays, social media tools such as short message service, Twitter, video, and web-based systems are more and more used in clinical follow-up, making clinical follow-up much more time- and cost-effective than ever before. However, as the most popular social media in China, little is known about the utility of smartphone WeChat application in follow-up. In this study, we aimed to investigate the feasibility and superiority of WeChat application in clinical follow-up. A total of 108 patients diagnosed with head and neck tumor were randomized to WeChat follow-up (WFU) group or telephone follow-up (TFU) group for 6-month follow-up. The follow-ups were delivered by WeChat or telephone at 2 weeks, 1, 2, 3, and 6 months to the patients after being discharged. The study measurements were time consumption for follow-up delivery, total economic cost, lost-to-follow-up rate, and overall satisfaction for the follow-up method. Time consumption in WFU group for each patient (23.36 ± 6.16 min) was significantly shorter than that in TFU group (42.89 ± 7.15 min) (P < 0.001); total economic cost in WFU group (RMB 90 Yuan) was much lower than that in TFU group (RMB 196 Yuan). Lost-to-follow-up rate in the WFU group was 7.02% (4/57) compared with TFU group, 9.80% (5/51), while no significance was observed (95% confidence interval [CI]: 0.176-2.740; P = 0.732). The overall satisfaction rate in WFU group was 94.34% (50/53) compared with 80.43% (37/46) in TFU group (95% CI: 0.057-0.067; P = 0.034). The smartphone WeChat application was found to be a viable option for follow-up in discharged patients with head and neck tumors. WFU was time-effective, cost-effective, and convenient in communication. This doctor-led follow-up model has the potential to establish a good physician-patient relationship by enhancing dynamic communications and providing individual health instructions. Chinese Clinical Trial Registry, ChiCTR-IOR-15007498; http://www.chictr.org.cn/ showproj.aspx?proj=12613.

Smartphone Application WeChat for Clinical Follow-up of Discharged Patients with Head and Neck Tumors: A Randomized Controlled Trial

PubMed Central

Lyu, Ke-Xing; Zhao, Jing; Wang, Bin; Xiong, Guan-Xia; Yang, Wei-Qiang; Liu, Qi-Hong; Zhu, Xiao-Lin; Sun, Wei; Jiang, Ai-Yun; Wen, Wei-Ping; Lei, Wen-Bin

2016-01-01

Background: Nowadays, social media tools such as short message service, Twitter, video, and web-based systems are more and more used in clinical follow-up, making clinical follow-up much more time- and cost-effective than ever before. However, as the most popular social media in China, little is known about the utility of smartphone WeChat application in follow-up. In this study, we aimed to investigate the feasibility and superiority of WeChat application in clinical follow-up. Methods: A total of 108 patients diagnosed with head and neck tumor were randomized to WeChat follow-up (WFU) group or telephone follow-up (TFU) group for 6-month follow-up. The follow-ups were delivered by WeChat or telephone at 2 weeks, 1, 2, 3, and 6 months to the patients after being discharged. The study measurements were time consumption for follow-up delivery, total economic cost, lost-to-follow-up rate, and overall satisfaction for the follow-up method. Results: Time consumption in WFU group for each patient (23.36 ± 6.16 min) was significantly shorter than that in TFU group (42.89 ± 7.15 min) (P < 0.001); total economic cost in WFU group (RMB 90 Yuan) was much lower than that in TFU group (RMB 196 Yuan). Lost-to-follow-up rate in the WFU group was 7.02% (4/57) compared with TFU group, 9.80% (5/51), while no significance was observed (95% confidence interval [CI]: 0.176–2.740; P = 0.732). The overall satisfaction rate in WFU group was 94.34% (50/53) compared with 80.43% (37/46) in TFU group (95% CI: 0.057–0.067; P = 0.034). Conclusions: The smartphone WeChat application was found to be a viable option for follow-up in discharged patients with head and neck tumors. WFU was time-effective, cost-effective, and convenient in communication. This doctor-led follow-up model has the potential to establish a good physician-patient relationship by enhancing dynamic communications and providing individual health instructions. Trial Registration: Chinese Clinical Trial Registry, Chi

An Overview of Cultural Historical Activity Theory (CHAT) Use in Classroom Research 2000 to 2009

ERIC Educational Resources Information Center

Nussbaumer, Doris

2012-01-01

Western educational researchers have eagerly accepted activity theory (AT) also known as cultural historical activity theory (CHAT) to collect and analyze data in rich description of complex situations. As this theory is applicable to a wide variety of disciplines, this review is limited to education and specifically to qualitative studies of…

More than "Hello" and "Bye-Bye": Opening and Closing the Online Chats in Mandarin Chinese

ERIC Educational Resources Information Center

Zhang, De

2014-01-01

Reporting on a descriptive study on the first semester Chinese language learners' openings and closings in online chats with age-peer native speakers of Chinese, this paper demonstrates the great promise that telecollaboration holds for foreign language education, and argues for an increasing role of pragmatics in Chinese language instruction, and…

From "Hello" to Higher-Order Thinking: The Effect of Coaching and Feedback on Online Chats

ERIC Educational Resources Information Center

Stein, David S.; Wanstreet, Constance E.; Slagle, Paula; Trinko, Lynn A.; Lutz, Michelle

2013-01-01

This exploratory study examined the effect of a coaching and feedback intervention in teaching presence and social presence on higher-order thinking in an online community of inquiry. Coaching occurred before each chat, and feedback was provided immediately afterwards. The findings suggest that over time, the frequency of higher-order thinking…

Rational design of aminoacyl-tRNA synthetase specific for p-acetyl-L-phenylalanine.

PubMed

Sun, Renhua; Zheng, Heng; Fang, Zhengzhi; Yao, Wenbing

2010-01-01

The Methanococcus jannaschii tRNA(Tyr)/tyrosyl-tRNA synthetase pair has been engineered to incorporate unnatural amino acids into proteins in Escherichia coli site-specifically. In order to add other unnatural amino acids into proteins by this approach, the amino acid binding site of M. jannaschii tyrosyl-tRNA synthetase need to be mutated. The crystal structures of M. jannaschii tyrosyl-tRNA synthetase and its mutations were determined, which provided an opportunity to design aminoacyl-tRNA synthetases specific for other unnatural amino acids. In our study, we attempted to design aminoacyl-tRNA synthetases being able to deliver p-acetyl-L-phenylalanine into proteins. p-Acetyl-L-phenylalanine was superimposed on tyrosyl in M. jannaschii tyrosyl-tRNA synthetase-tyrosine complex. Tyr32 needed to be changed to non-polar amino acid with shorter side chain, Val, Leu, Ile, Gly or Ala, in order to reduce steric clash and provide hydrophobic environment to acetyl on p-acetyl-L-phenylalanine. Asp158 and Ile159 would be changed to specific amino acids for the same reason. So we designed 60 aminoacyl-tRNA synthetases. Binding of these aminoacyl-tRNA synthetases with p-acetyl-L-phenylalanine indicated that only 15 of them turned out to be able to bind p-acetyl-L-phenylalanine with reasonable poses. Binding affinity computation proved that the mutation of Tyr32Leu and Asp158Gly benefited p-acetyl-L-phenylalanine binding. And two of the designed aminoacyl-tRNA synthetases had considerable binding affinities. They seemed to be very promising to be able to incorporate p-acetyl-L-phenylalanine into proteins in E. coli. The results show that the combination of homology modeling and molecular docking is a feasible method to filter inappropriate mutations in molecular design and point out beneficial mutations. Copyright 2009 Elsevier Inc. All rights reserved.

Structural, morphological, and physicochemical properties of acetylated high-, medium-, and low-amylose rice starches.

PubMed

Colussi, Rosana; Pinto, Vania Zanella; El Halal, Shanise Lisie Mello; Vanier, Nathan Levien; Villanova, Franciene Almeida; Marques E Silva, Ricardo; da Rosa Zavareze, Elessandra; Dias, Alvaro Renato Guerra

2014-03-15

The high-, medium-, and low-amylose rice starches were isolated by the alkaline method and acetylated by using acetic anhydride for 10, 30, and 90 min of reaction. The degree of substitution (DS), the Fourier-transformed infrared spectroscopy (FTIR), the X-ray diffractograms, the thermal, morphological, and pasting properties, and the swelling power and solubility of native and acetylated starches were evaluated. The DS of the low-amylose rice starch was higher than the DS of the medium- and the high-amylose rice starches. The introduction of acetyl groups was confirmed by FTIR spectroscopy. The acetylation treatment reduced the crystallinity, the viscosity, the swelling power, and the solubility of rice starch; however, there was an increase in the thermal stability of rice starch modified by acetylation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Acetylation-dependent ADP-ribosylation by Trypanosoma brucei Sir2.

PubMed

Kowieski, Terri M; Lee, Susan; Denu, John M

2008-02-29

Sirtuins are a highly conserved family of proteins implicated in diverse cellular processes such as gene silencing, aging, and metabolic regulation. Although many sirtuins catalyze a well characterized protein/histone deacetylation reaction, there are a number of reports that suggest protein ADP-ribosyltransferase activity. Here we explored the mechanisms of ADP-ribosylation using the Trypanosoma brucei Sir2 homologue TbSIR2rp1 as a model for sirtuins that reportedly display both activities. Steady-state kinetic analysis revealed a highly active histone deacetylase (k cat = 0.1 s(-1), with Km values of 42 microm and for NAD+ and 65 microm for acetylated substrate). A series of biochemical assays revealed that TbSIR2rp1 ADP-ribosylation of protein/histone requires an acetylated substrate. The data are consistent with two distinct ADP-ribosylation pathways that involve an acetylated substrate, NAD+ and TbSIR2rp1 as follows: 1) a noncatalytic reaction between the deacetylation product O-acetyl-ADP-ribose (or its hydrolysis product ADP-ribose) and histones, and 2) a more efficient mechanism involving interception of an ADP-ribose-acetylpeptide-enzyme intermediate by a side-chain nucleophile from bound histone. However, the sum of both ADP-ribosylation reactions was approximately 5 orders of magnitude slower than histone deacetylation under identical conditions. The biological implications of these results are discussed.

Analysis of chats on French internet forums about drugs and pregnancy.

PubMed

Palosse-Cantaloube, Lucie; Lacroix, Isabelle; Rousseau, Vanessa; Bagheri, Haleh; Montastruc, Jean-Louis; Damase-Michel, Christine

2014-12-01

Some pregnant women use the internet to search for medical information. However, online information is not controlled. The objectives were to describe French online chats about drugs and pregnancy and evaluate the quality and reliability of information shared by internet users. This French descriptive study was performed in November 2012. In order to identify drugs and pregnancy-related forum websites, we used three French key words: forum, pregnancy and drug. We explored the first 10 websites from the search result. Diseases were described using the International Classification of Diseases and drugs classified with the Anatomical Therapeutic Chemical codes and the FDA risk classification. We selected 115 questions that were mainly posted by pregnant internet users in French forums. Drugs raising questions were mostly "nervous system," "anti-infective for systemic use" and "respiratory system" drugs. The risk during pregnancy for nearly half of these drugs had not been evaluated properly. Health professionals were only involved in 7% of the 214 answers. Internet users advised to take a drug in 21% of their answers. Thirty-four percent of those recommended drugs had not been well-evaluated or were potentially at risk during pregnancy. Finally, 12% of the answers could be at risk for pregnant woman. This study shows that information related to drugs and pregnancy in online chats could be at risk for pregnant women. Internet users must be aware that online forums are not reliable sources of information. Copyright © 2014 John Wiley & Sons, Ltd.

Increased resistance to acetaminophen hepatotoxicity in mice lacking glutathione S-transferase Pi

PubMed Central

Henderson, Colin J.; Wolf, C. Roland; Kitteringham, Neil; Powell, Helen; Otto, Diana; Park, B. Kevin

2000-01-01

Overdose of acetaminophen, a widely used analgesic drug, can result in severe hepatotoxicity and is often fatal. This toxic reaction is associated with metabolic activation by the P450 system to form a quinoneimine metabolite, N-acetyl-p-benzoquinoneimine (NAPQI), which covalently binds to proteins and other macromolecules to cause cellular damage. At low doses, NAPQI is efficiently detoxified, principally by conjugation with glutathione, a reaction catalyzed in part by the glutathione S-transferases (GST), such as GST Pi. To assess the role of GST in acetaminophen hepatotoxicity, we examined acetaminophen metabolism and liver damage in mice nulled for GstP (GstP1/P2(−/−)). Contrary to our expectations, instead of being more sensitive, GstP null mice were highly resistant to the hepatotoxic effects of this compound. No significant differences between wild-type (GstP1/P2(+/+)) mice and GstP1/P2(−/−) nulls in either the rate or route of metabolism, particularly to glutathione conjugates, or in the levels of covalent binding of acetaminophen-reactive metabolites to cellular protein were observed. However, although a similar rapid depletion of hepatic reduced glutathione (GSH) was found in both GstP1/P2(+/+) and GstP1/P2(−/−) mice, GSH levels only recovered in the GstP1/P2(−/−) mice. These data demonstrate that GstP does not contribute in vivo to the formation of glutathione conjugates of acetaminophen but plays a novel and unexpected role in the toxicity of this compound. This study identifies new ways in which GST can modulate cellular sensitivity to toxic effects and suggests that the level of GST Pi may be an important and contributing factor in the sensitivity of patients with acetaminophen-induced hepatotoxicity. PMID:11058152

Activation of AMP-activated Protein Kinase by Metformin Induces Protein Acetylation in Prostate and Ovarian Cancer Cells*

PubMed Central

Galdieri, Luciano; Gatla, Himavanth; Vancurova, Ivana; Vancura, Ales

2016-01-01

AMP-activated protein kinase (AMPK) is an energy sensor and master regulator of metabolism. AMPK functions as a fuel gauge monitoring systemic and cellular energy status. Activation of AMPK occurs when the intracellular AMP/ATP ratio increases and leads to a metabolic switch from anabolism to catabolism. AMPK phosphorylates and inhibits acetyl-CoA carboxylase (ACC), which catalyzes carboxylation of acetyl-CoA to malonyl-CoA, the first and rate-limiting reaction in de novo synthesis of fatty acids. AMPK thus regulates homeostasis of acetyl-CoA, a key metabolite at the crossroads of metabolism, signaling, chromatin structure, and transcription. Nucleocytosolic concentration of acetyl-CoA affects histone acetylation and links metabolism and chromatin structure. Here we show that activation of AMPK with the widely used antidiabetic drug metformin or with the AMP mimetic 5-aminoimidazole-4-carboxamide ribonucleotide increases the inhibitory phosphorylation of ACC and decreases the conversion of acetyl-CoA to malonyl-CoA, leading to increased protein acetylation and altered gene expression in prostate and ovarian cancer cells. Direct inhibition of ACC with allosteric inhibitor 5-(tetradecyloxy)-2-furoic acid also increases acetylation of histones and non-histone proteins. Because AMPK activation requires liver kinase B1, metformin does not induce protein acetylation in liver kinase B1-deficient cells. Together, our data indicate that AMPK regulates the availability of nucleocytosolic acetyl-CoA for protein acetylation and that AMPK activators, such as metformin, have the capacity to increase protein acetylation and alter patterns of gene expression, further expanding the plethora of metformin's physiological effects. PMID:27733682

Global-scale profiling of differential expressed lysine acetylated proteins in colorectal cancer tumors and paired liver metastases.

PubMed

Shen, Zhanlong; Wang, Bo; Luo, Jianyuan; Jiang, Kewei; Zhang, Hui; Mustonen, Harri; Puolakkainen, Pauli; Zhu, Jun; Ye, Yingjiang; Wang, Shan

2016-06-16

Lysine acetylated modification was indicated to impact colorectal cancer (CRC)'s distant metastasis. However, the global acetylated proteins in CRC and the differential expressed acetylated proteins and acetylated sites between CRC primary and distant metastatic tumor remains unclear. Our aim was to construct a complete atlas of acetylome in CRC and paired liver metastases. Combining high affinity enrichment of acetylated peptides with high sensitive mass spectrometry, we identified 603 acetylation sites from 316 proteins, among which 462 acetylation sites corresponding to 243 proteins were quantified. We further classified them into groups according to cell component, molecular function and biological process and analyzed the metabolic pathways, domain structures and protein interaction networks. Finally, we evaluated the differentially expressed lysine acetylation sites and revealed that 31 acetylated sites of 22 proteins were downregulated in CRC liver metastases compared to that in primary CRC while 40 acetylated sites of 32 proteins were upregulated, of which HIST2H3AK19Ac and H2BLK121Ac were the acetylated histones most changed, while TPM2 K152Ac and ADH1B K331Ac were the acetylated non-histones most altered. These results provide an expanded understanding of acetylome in CRC and its distant metastasis, and might prove applicable in the molecular targeted therapy of metastatic CRC. This study described provides, for the first time, that full-scale profiling of lysine acetylated proteins were identified and quantified in colorectal cancer (CRC) and paired liver metastases. The novelty of the study is that we constructed a complete atlas of acetylome in CRC and paired liver metastases. Moreover, we analyzed these differentially expressed acetylated proteins in cell component, molecular function and biological process. In addition, metabolic pathways, domain structures and protein interaction networks of acetylated proteins were also investigated. Our approaches

Starch-based xerogels: Effect of acetylation on Physicochemical and rheological properties.

PubMed

Kemas, Chinwe U; Ngwuluka, Ndidi C; Ochekpe, Nelson A; Nep, Elijah I

2017-05-01

This study was aimed at evaluating the physicochemical and rheological properties of starch-based xerogels. The starch from the shoots of Borassus aethiopium was physically modified by xerogelization, and chemically by acetylation, and combination of acetylation and xerogelization. The solubility, swelling and syneresis of the starches were determined by gravimetric techniques. Evaluation of the native starch and derivatives was done using microscopy, Fourier transform infra-red (FTIR), x-ray diffractometry (XRD), and 1 H NMR spectroscopy. Rheological evaluation was done on 10%w/v dispersions using a Bohlin Gemini rheometer (fitted with a 55mm and 2° cone and plate geometry with gap of 70). The diffractograms displayed three peaks, centered on 2θ=15.3, 17.2 and 23.1° for the native and the starch acetate while the xerogel and the starch acetate xerogel were amorphous. The 1 H NMR and FTIR confirmed the presence of acetyl groups at about 2.05ppm and 1720cm -1 , respectively. Acetylation of the native starch resulted in improvement of solubility. The starch acetate-xerogel sample formed viscoelastic gels without the need for heating. Acetylation and/or xerogelization of the native starch inhibited syneresis. Starch acetate-xerogels, may find application as stabilizer or suspending agent in liquid food and pharmaceutical formulations. Copyright © 2017 Elsevier B.V. All rights reserved.

Acetylation of Histone Deacetylase 1 Regulates NuRD Corepressor Complex Activity*

PubMed Central

Yang, Tao; Jian, Wei; Luo, Yi; Fu, Xueqi; Noguchi, Constance; Bungert, Jörg; Huang, Suming; Qiu, Yi

2012-01-01

Histone deacetylases (HDACs) play important roles in regulating cell proliferation and differentiation. The HDAC1-containing NuRD complex is generally considered as a corepressor complex and is required for GATA-1-mediated repression. However, recent studies also show that the NuRD complex is involved in GATA-1-mediated gene activation. We tested whether the GATA-1-associated NuRD complex loses its deacetylase activity and commits the GATA-1 complex to become an activator during erythropoiesis. We found that GATA-1-associated deacetylase activity gradually decreased upon induction of erythroid differentiation. GATA-1-associated HDAC1 is increasingly acetylated after differentiation. It has been demonstrated earlier that acetylated HDAC1 has no deacetylase activity. Indeed, overexpression of an HDAC1 mutant, which mimics acetylated HDAC1, promotes GATA-1-mediated transcription and erythroid differentiation. Furthermore, during erythroid differentiation, acetylated HDAC1 recruitment is increased at GATA-1-activated genes, whereas it is significantly decreased at GATA-1-repressed genes. Interestingly, deacetylase activity is not required for Mi2 remodeling activity, suggesting that remodeling activity may be required for both activation and repression. Thus, our data suggest that NuRD can function as a coactivator or repressor and that acetylated HDAC1 converts the NuRD complex from a repressor to an activator during GATA-1-directed erythroid differentiation. PMID:23014989

Crystal structure of tabtoxin resistance protein complexed with acetyl coenzyme A reveals the mechanism for {beta}-lactam acetylation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

He, H.; Ding, Y.; Bartlam, M.

2003-01-31

Tabtoxin resistance protein (TTR) is an enzyme that renders tabtoxin-producing pathogens, such as Pseudomonas syringae, tolerant to their own phytotoxins. Here, we report the crystal structure of TTR complexed with its natural cofactor, acetyl coenzyme A (AcCoA), to 1.55 {angstrom} resolution. The binary complex forms a characteristic 'V' shape for substrate binding and contains the four motifs conserved in the GCN5-related N-acetyltransferase (GNAT) superfamily, which also includes the histone acetyltransferases (HATs). A single-step mechanism is proposed to explain the function of three conserved residues, Glu92, Asp130 and Tyr141, in catalyzing the acetyl group transfer to its substrate. We also reportmore » that TTR possesses HAT activity and suggest an evolutionary relationship between TTR and other GNAT members.« less

N-Terminal Acetylation Inhibits Protein Targeting to the Endoplasmic Reticulum

PubMed Central

Forte, Gabriella M. A.; Pool, Martin R.; Stirling, Colin J.

2011-01-01

Amino-terminal acetylation is probably the most common protein modification in eukaryotes with as many as 50%–80% of proteins reportedly altered in this way. Here we report a systematic analysis of the predicted N-terminal processing of cytosolic proteins versus those destined to be sorted to the secretory pathway. While cytosolic proteins were profoundly biased in favour of processing, we found an equal and opposite bias against such modification for secretory proteins. Mutations in secretory signal sequences that led to their acetylation resulted in mis-sorting to the cytosol in a manner that was dependent upon the N-terminal processing machinery. Hence N-terminal acetylation represents an early determining step in the cellular sorting of nascent polypeptides that appears to be conserved across a wide range of species. PMID:21655302

Combining IM and Vendor-Based Chat: A Report from the Frontlines of an Integrated Service

ERIC Educational Resources Information Center

Ward, David; Kern, M. Kathleen

2006-01-01

Driven by studies showing that Millennials (ages 18-24) have adopted IM (instant messaging) as a standard communications medium, many libraries are reaching out to their own patrons in this way. At the same time, some of these libraries have invested thousands of dollars in vendor-based chat reference solutions that provide duplicate…

Chronic exposure to 60-Hz electric fields: effects on pineal function in the rat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, B.W.; Anderson, L.E.; Hilton, D.I.

As a component of studies to search for effects of 60-Hz electric field exposure on mammalian endocrine function, concentrations of melatonin, 5-methoxytryptophol, and serotonin-N-acetyl transferase activity were measured in the pineal glands of rats exposed or sham-exposed at 65 kV/m for 30 days.In two replicate experiments there were statistically significant differences between exposed and control rats in that the normal nocturnal increase in pineal melatonin content was depressed in the exposed animals. Concentrations of 5-methoxytryptophol were increased in the pineal glands of the exposed groups when compared to sham-exposed controls. An alteration was also observed in serotonin-N-acetyl transferase activity, withmore » lower levels measured in pineal glands from exposed animals.« less

Lifespan extension and increased resistance to environmental stressors by N-Acetyl-L-Cysteine in Caenorhabditis elegans

PubMed Central

Oh, Seung-Il; Park, Jin-Kook; Park, Sang-Kyu

2015-01-01

OBJECTIVE: This study was performed to determine the effect of N-acetyl-L-cysteine, a modified sulfur-containing amino acid that acts as a strong cellular antioxidant, on the response to environmental stressors and on aging in C. elegans. METHOD: The survival of worms under oxidative stress conditions induced by paraquat was evaluated with and without in vivo N-acetyl-L-cysteine treatment. The effect of N-acetyl-L-cysteine on the response to other environmental stressors, including heat stress and ultraviolet irradiation (UV), was also monitored. To investigate the effect on aging, we examined changes in lifespan, fertility, and expression of age-related biomarkers in C. elegans after N-acetyl-L-cysteine treatment. RESULTS: Dietary N-acetyl-L-cysteine supplementation significantly increased resistance to oxidative stress, heat stress, and UV irradiation in C. elegans. In addition, N-acetyl-L-cysteine supplementation significantly extended both the mean and maximum lifespan of C. elegans. The mean lifespan was extended by up to 30.5% with 5 mM N-acetyl-L-cysteine treatment, and the maximum lifespan was increased by 8 days. N-acetyl-L-cysteine supplementation also increased the total number of progeny produced and extended the gravid period of C. elegans. The green fluorescent protein reporter assay revealed that expression of the stress-responsive genes, sod-3 and hsp-16.2, increased significantly following N-acetyl-L-cysteine treatment. CONCLUSION: N-acetyl-L-cysteine supplementation confers a longevity phenotype in C. elegans, possibly through increased resistance to environmental stressors. PMID:26039957

Homogentisate solanesyl transferase (HST) cDNA’s in maize

USDA-ARS?s Scientific Manuscript database

Maize white seedling 3 (w3) has served as a model albino-seedling mutant since its discovery in 1923. We show that the w3 phenotype is caused by disruptions in homogentisate solanesyl transferase (HST), an enzyme that catalyzes the committed step in plastoquinone-9 (PQ9) biosynthesis. This reaction ...

Purification and characterization of enantioselective N-acetyl-β-Phe acylases from Burkholderia sp. AJ110349.

PubMed

Imabayashi, Yuki; Suzuki, Shun'ichi; Kawasaki, Hisashi; Nakamatsu, Tsuyoshi

2016-01-01

For the production of enantiopure β-amino acids, enantioselective resolution of N-acyl β-amino acids using acylases, especially those recognizing N-acetyl-β-amino acids, is one of the most attractive methods. Burkholderia sp. AJ110349 had been reported to exhibit either (R)- or (S)-enantiomer selective N-acetyl-β-Phe amidohydrolyzing activity, and in this study, both (R)- and (S)-enantioselective N-acetyl-β-Phe acylases were purified to be electrophoretically pure and determined the sequences, respectively. They were quite different in terms of enantioselectivities and in their amino acids sequences and molecular weights. Although both the purified acylases were confirmed to catalyze N-acetyl hydrolyzing activities, neither of them show sequence similarities to the N-acetyl-α-amino acid acylases reported thus far. Both (R)- and (S)-enantioselective N-acetyl-β-Phe acylase were expressed in Escherichia coli. Using these recombinant strains, enantiomerically pure (R)-β-Phe (>99% ee) and (S)-β-Phe (>99% ee) were obtained from the racemic substrate.

Structural Basis for the De-N-acetylation of Poly-β-1,6-N-acetyl-d-glucosamine in Gram-positive Bacteria*

PubMed Central

Little, Dustin J.; Bamford, Natalie C.; Pokrovskaya, Varvara; Robinson, Howard; Nitz, Mark; Howell, P. Lynne

2014-01-01

Exopolysaccharides are required for the development and integrity of biofilms produced by a wide variety of bacteria. In staphylococci, partial de-N-acetylation of the exopolysaccharide poly-β-1,6-N-acetyl-d-glucosamine (PNAG) by the extracellular protein IcaB is required for biofilm formation. To understand the molecular basis for PNAG de-N-acetylation, the structure of IcaB from Ammonifex degensii (IcaBAd) has been determined to 1.7 Å resolution. The structure of IcaBAd reveals a (β/α)7 barrel common to the family four carbohydrate esterases (CE4s) with the canonical motifs circularly permuted. The metal dependence of IcaBAd is similar to most CE4s showing the maximum rates of de-N-acetylation with Ni2+, Co2+, and Zn2+. From docking studies with β-1,6-GlcNAc oligomers and structural comparison to PgaB from Escherichia coli, the Gram-negative homologue of IcaB, we identify Arg-45, Tyr-67, and Trp-180 as key residues for PNAG binding during catalysis. The absence of these residues in PgaB provides a rationale for the requirement of a C-terminal domain for efficient deacetylation of PNAG in Gram-negative species. Mutational analysis of conserved active site residues suggests that IcaB uses an altered catalytic mechanism in comparison to other characterized CE4 members. Furthermore, we identified a conserved surface-exposed hydrophobic loop found only in Gram-positive homologues of IcaB. Our data suggest that this loop is required for membrane association and likely anchors IcaB to the membrane during polysaccharide biosynthesis. The work presented herein will help guide the design of IcaB inhibitors to combat biofilm formation by staphylococci. PMID:25359777

From to : Nicknames, Play and Identity on Internet Relay Chat.

ERIC Educational Resources Information Center

Bechar-Israeli, Haya

1995-01-01

Examines nicknames of Internet Relay Chat (IRC) users, whose identities are condensed into a single line which states their nicknames, the electronic address, and a slogan or the users' real names. Demonstrates that although people play games with their nicknames, the nicknames they choose are an inherent part of their Net identity and their…

Screening for Autism in Iranian Preschoolers: Contrasting M-CHAT and a Scale Developed in Iran

ERIC Educational Resources Information Center

Samadi, Sayyed Ali; McConkey, Roy

2015-01-01

Suitable screening instruments for the early diagnosis of autism are not readily available for use with preschoolers in non-Western countries. This study evaluated two tools: M-CHAT which is widely used internationally and one developed in Iran called Hiva. A population sample was recruited of nearly 3000 preschoolers in one Iranian city. Parents…

Purmorphamine as a Shh Signaling Activator Small Molecule Promotes Motor Neuron Differentiation of Mesenchymal Stem Cells Cultured on Nanofibrous PCL Scaffold.

PubMed

Bahrami, Naghmeh; Bayat, Mohammad; Mohamadnia, Abdolreza; Khakbiz, Mehrdad; Yazdankhah, Meysam; Ai, Jafar; Ebrahimi-Barough, Somayeh

2017-09-01

There is variety of stem cell sources but problems in ethical issues, contamination, and normal karyotype cause many limitations in obtaining and using these cells. The cells in Wharton's jelly region of umbilical cord are abundant and available stem cells with low immunological incompatibility, which could be considered for cell replacement therapy. Small molecules have been presented as less expensive biologically active compounds that can regulate different developmental process. Purmorphamine (PMA) is a small molecule that, according to some studies, possesses certain differentiation effects. In this study, we investigated the effect of the PMA on Wharton's jelly mesenchymal stem cell (WJ-MSC) differentiation into motor neuronal lineages instead of sonic hedgehog (Shh) on PCL scaffold. After exposing to induction media for 15 days, the cells were characterized for expression of motor neuron markers including PAX6, NF-H, Islet1, HB9, and choline acetyl transferase (ChAT) by quantitative reverse transcription (PCR) and immunocytochemistry. Our results demonstrated that induced WJ-MSCs with PMA could significantly express motor neuron markers in RNA and protein levels 15 days post induction. These results suggested that WJ-MSCs can differentiate to motor neuron-like cells with PMA on PCL scaffold and might provide a potential source in cell therapy for nervous system.

Reversal of hypermethylation and reactivation of glutathione S-transferase pi 1 gene by curcumin in breast cancer cell line.

PubMed

Kumar, Umesh; Sharma, Ujjawal; Rathi, Garima

2017-02-01

One of the mechanisms for epigenetic silencing of tumor suppressor genes is hypermethylation of cytosine residue at CpG islands at their promoter region that contributes to malignant progression of tumor. Therefore, activation of tumor suppressor genes that have been silenced by promoter methylation is considered to be very attractive molecular target for cancer therapy. Epigenetic silencing of glutathione S-transferase pi 1, a tumor suppressor gene, is involved in various types of cancers including breast cancer. Epigenetic silencing of tumor suppressor genes can be reversed by several molecules including natural compounds such as polyphenols that can act as a hypomethylating agent. Curcumin has been found to specifically target various tumor suppressor genes and alter their expression. To check the effect of curcumin on the methylation pattern of glutathione S-transferase pi 1 gene in MCF-7 breast cancer cell line in dose-dependent manner. To check the reversal of methylation pattern of hypermethylated glutathione S-transferase pi 1, MCF-7 breast cancer cell line was treated with different concentrations of curcumin for different time periods. DNA and proteins of treated and untreated cell lines were isolated, and methylation status of the promoter region of glutathione S-transferase pi 1 was analyzed using methylation-specific polymerase chain reaction assay, and expression of this gene was analyzed by immunoblotting using specific antibodies against glutathione S-transferase pi 1. A very low and a nontoxic concentration (10 µM) of curcumin treatment was able to reverse the hypermethylation and led to reactivation of glutathione S-transferase pi 1 protein expression in MCF-7 cells after 72 h of treatment, although the IC 50 value of curcumin was found to be at 20 µM. However, curcumin less than 3 µM of curcumin could not alter the promoter methylation pattern of glutathione S-transferase pi 1. Treatment of breast cancer MCF-7 cells with curcumin

Post-translational Acetylation of MbtA Modulates Mycobacterial Siderophore Biosynthesis*

PubMed Central

Vergnolle, Olivia; Xu, Hua; Tufariello, JoAnn M.; Favrot, Lorenza; Malek, Adel A.; Jacobs, William R.; Blanchard, John S.

2016-01-01

Iron is an essential element for life, but its soluble form is scarce in the environment and is rarer in the human body. Mtb (Mycobacterium tuberculosis) produces two aryl-capped siderophores, mycobactin (MBT) and carboxymycobactin (cMBT), to chelate intracellular iron. The adenylating enzyme MbtA catalyzes the first step of mycobactin biosynthesis in two half-reactions: activation of the salicylic acid as an acyl-adenylate and ligation onto the acyl carrier protein (ACP) domain of MbtB to form covalently salicylated MbtB-ACP. We report the first apo-MbtA structure from Mycobacterium smegmatis at 2.3 Å. We demonstrate here that MbtA activity can be reversibly, post-translationally regulated by acetylation. Indeed the mycobacterial Pat (protein lysine acetyltransferase), Rv0998, specifically acetylates MbtA on lysine 546, in a cAMP-dependent manner, leading to enzyme inhibition. MbtA acetylation can be reversed by the NAD+-dependent DAc (deacetyltransferase), Rv1151c. Deletion of Pat and DAc genes in Mtb revealed distinct phenotypes for strains lacking one or the other gene at low pH and limiting iron conditions. This study establishes a direct connection between the reversible acetylation system Pat/DAc and the ability of Mtb to adapt in limited iron conditions, which is critical for mycobacterial infection. PMID:27566542

Downregulation of RWA genes in hybrid aspen affects xylan acetylation and wood saccharification.

PubMed

Pawar, Prashant Mohan-Anupama; Ratke, Christine; Balasubramanian, Vimal K; Chong, Sun-Li; Gandla, Madhavi Latha; Adriasola, Mathilda; Sparrman, Tobias; Hedenström, Mattias; Szwaj, Klaudia; Derba-Maceluch, Marta; Gaertner, Cyril; Mouille, Gregory; Ezcurra, Ines; Tenkanen, Maija; Jönsson, Leif J; Mellerowicz, Ewa J

2017-06-01

High acetylation of angiosperm wood hinders its conversion to sugars by glycoside hydrolases, subsequent ethanol fermentation and (hence) its use for biofuel production. We studied the REDUCED WALL ACETYLATION (RWA) gene family of the hardwood model Populus to evaluate its potential for improving saccharification. The family has two clades, AB and CD, containing two genes each. All four genes are expressed in developing wood but only RWA-A and -B are activated by master switches of the secondary cell wall PtNST1 and PtMYB21. Histochemical analysis of promoter::GUS lines in hybrid aspen (Populus tremula × tremuloides) showed activation of RWA-A and -B promoters in the secondary wall formation zone, while RWA-C and -D promoter activity was diffuse. Ectopic downregulation of either clade reduced wood xylan and xyloglucan acetylation. Suppressing both clades simultaneously using the wood-specific promoter reduced wood acetylation by 25% and decreased acetylation at position 2 of Xylp in the dimethyl sulfoxide-extracted xylan. This did not affect plant growth but decreased xylose and increased glucose contents in the noncellulosic monosaccharide fraction, and increased glucose and xylose yields of wood enzymatic hydrolysis without pretreatment. Both RWA clades regulate wood xylan acetylation in aspen and are promising targets to improve wood saccharification. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Gene encoding acetyl-coenzyme A carboxylase

DOEpatents

Roessler, Paul G.; Ohlrogge, John B.

1996-01-01

A DNA encoding an acetyl-coenzyme A carboxylase (ACCase) from a photosynthetic organism and functional derivatives thereof which are resistant to inhibition from certain herbicides. This gene can be placed in organisms to increase their fatty acid content or to render them resistant to certain herbicides.

Mycobacterium tuberculosis Arylamine N-Acetyltransferase Acetylates and Thus Inactivates para-Aminosalicylic Acid.

PubMed

Wang, Xude; Yang, Shanshan; Gu, Jing; Deng, Jiaoyu

2016-12-01

Mycobacterium tuberculosis arylamine N-acetyltransferase (TBNAT) is able to acetylate para-aminosalicylic acid (PAS) both in vitro and in vivo as determined by high-performance liquid chromatography (HPLC) and electrospray ionization-mass spectrometry (ESI-MS) techniques. The antituberculosis activity of the acetylated PAS is significantly reduced. As a result, overexpression of TBNAT in M. tuberculosis results in PAS resistance, as determined by MIC tests and drug exposure experiments. Taken together, our results suggest that TBNAT from M. tuberculosis is able to inactivate PAS by acetylating the compound. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Mediated Group Development and Dynamics: An Examination of Video Chatting, Twitter, and Facebook in Group Assignments

ERIC Educational Resources Information Center

Frisby, Brandi N.; Kaufmann, Renee; Beck, Anna-Carrie

2016-01-01

Instructors incorporate technological tools into the classroom to address short attention spans, appeal to technologically savvy students, and to increase engagement. This study used both quantitative descriptive and qualitative embedded assessment data to examine the use of three popular tools (i.e. Twitter, Facebook, and video chatting) in…

Acetylation of mitochondrial proteins by GCN5L1 promotes enhanced fatty acid oxidation in the heart.

PubMed

Thapa, Dharendra; Zhang, Manling; Manning, Janet R; Guimarães, Danielle A; Stoner, Michael W; O'Doherty, Robert M; Shiva, Sruti; Scott, Iain

2017-08-01

Lysine acetylation is a reversible posttranslational modification and is particularly important in the regulation of mitochondrial metabolic enzymes. Acetylation uses acetyl-CoA derived from fuel metabolism as a cofactor, thereby linking nutrition to metabolic activity. In the present study, we investigated how mitochondrial acetylation status in the heart is controlled by food intake and how these changes affect mitochondrial metabolism. We found that there was a significant increase in cardiac mitochondrial protein acetylation in mice fed a long-term high-fat diet and that this change correlated with an increase in the abundance of the mitochondrial acetyltransferase-related protein GCN5L1. We showed that the acetylation status of several mitochondrial fatty acid oxidation enzymes (long-chain acyl-CoA dehydrogenase, short-chain acyl-CoA dehydrogenase, and hydroxyacyl-CoA dehydrogenase) and a pyruvate oxidation enzyme (pyruvate dehydrogenase) was significantly upregulated in high-fat diet-fed mice and that the increase in long-chain and short-chain acyl-CoA dehydrogenase acetylation correlated with increased enzymatic activity. Finally, we demonstrated that the acetylation of mitochondrial fatty acid oxidation proteins was decreased after GCN5L1 knockdown and that the reduced acetylation led to diminished fatty acid oxidation in cultured H9C2 cells. These data indicate that lysine acetylation promotes fatty acid oxidation in the heart and that this modification is regulated in part by the activity of GCN5L1. NEW & NOTEWORTHY Recent research has shown that acetylation of mitochondrial fatty acid oxidation enzymes has greatly contrasting effects on their activity in different tissues. Here, we provide new evidence that acetylation of cardiac mitochondrial fatty acid oxidation enzymes by GCN5L1 significantly upregulates their activity in diet-induced obese mice. Copyright © 2017 the American Physiological Society.

Acetylation-Dependent Chromatin Reorganization by BRDT, a Testis-Specific Bromodomain-Containing Protein

PubMed Central

Pivot-Pajot, Christophe; Caron, Cécile; Govin, Jérôme; Vion, Alexandre; Rousseaux, Sophie; Khochbin, Saadi

2003-01-01

The association between histone acetylation and replacement observed during spermatogenesis prompted us to consider the testis as a source for potential factors capable of remodelling acetylated chromatin. A systematic search of data banks for open reading frames encoding testis-specific bromodomain-containing proteins focused our attention on BRDT, a testis-specific protein of unknown function containing two bromodomains. BRDT specifically binds hyperacetylated histone H4 tail depending on the integrity of both bromodomains. Moreover, in somatic cells, the ectopic expression of BRDT triggered a dramatic reorganization of the chromatin only after induction of histone hyperacetylation by trichostatin A (TSA). We then defined critical domains of BRDT involved in its activity. Both bromodomains of BRDT, as well as flanking regions, were found indispensable for its histone acetylation-dependent remodelling activity. Interestingly, we also observed that recombinant BRDT was capable of inducing reorganization of the chromatin of isolated nuclei in vitro only when the nuclei were from TSA-treated cells. This assay also allowed us to show that the action of BRDT was ATP independent, suggesting a structural role for the protein in the remodelling of acetylated chromatin. This is the first demonstration of a large-scale reorganization of acetylated chromatin induced by a specific factor. PMID:12861021

Altered mitochondrial acetylation profiles in a kainic acid model of temporal lobe epilepsy.

PubMed

Gano, Lindsey B; Liang, Li-Ping; Ryan, Kristen; Michel, Cole R; Gomez, Joe; Vassilopoulos, Athanassios; Reisdorph, Nichole; Fritz, Kristofer S; Patel, Manisha

2018-08-01

Impaired bioenergetics and oxidative damage in the mitochondria are implicated in the etiology of temporal lobe epilepsy, and hyperacetylation of mitochondrial proteins has recently emerged as a critical negative regulator of mitochondrial functions. However, the roles of mitochondrial acetylation and activity of the primary mitochondrial deacetylase, SIRT3, have not been explored in acquired epilepsy. We investigated changes in mitochondrial acetylation and SIRT3 activity in the development of chronic epilepsy in the kainic acid rat model of TLE. Hippocampal measurements were made at 48 h, 1 week and 12 weeks corresponding to the acute, latent and chronic stages of epileptogenesis. Assessment of hippocampal bioenergetics demonstrated a ≥ 27% decrease in the ATP/ADP ratio at all phases of epileptogenesis (p < 0.05), whereas cellular NAD+ levels were decreased by ≥ 41% in the acute and latent time points (p < 0.05), but not in chronically epileptic rats. In spontaneously epileptic rats, we found decreased protein expression of SIRT3 and a 60% increase in global mitochondrial acetylation, as well as enhanced acetylation of the known SIRT3 substrates MnSOD, Ndufa9 of Complex I and IDH2 (all p < 0.05), suggesting SIRT3 dysfunction in chronic epilepsy. Mass spectrometry-based acetylomics investigation of hippocampal mitochondria demonstrated a 79% increase in unique acetylated proteins from rats in the chronic phase vs. controls. Pathway analysis identified numerous mitochondrial bioenergetic pathways affected by mitochondrial acetylation. These results suggest SIRT3 dysfunction and aberrant protein acetylation may contribute to mitochondrial dysfunction in chronic epilepsy. Copyright © 2018 Elsevier Inc. All rights reserved.

Biosynthesis of acetyl-coenzyme A in the electric organ of Torpedo marmorata in relation to acetylcholine metabolism.

PubMed Central

Diebler, M F; Morot-Gaudry, Y

1977-01-01

Formation of acetyl-CoA through acetyl-CoA synthetase (forward reaction) and through choline acyltransferase (backward reaction) was investigated in tissue extract from the electric organ of Torpedo marmorata. When the tissue extract was submitted to gel filtration on Sephadex G-25, the formation of acetyl-CoA by acetyl-CoA synthetase appeared fully dependent on ATP and CoA and partially dependent on acetate (an endogenous supply of acetate is discussed). Choline acetyltransferase was a potent source of acetyl-CoA, only requiring acetylcholine and CoA, and was much more efficient than acetyl-CoA synthetase for concentrations of acetylcholine likely to be present in nerve endings. PMID:23101

Mannanase hydrolysis of spruce galactoglucomannan focusing on the influence of acetylation on enzymatic mannan degradation.

PubMed

Arnling Bååth, Jenny; Martínez-Abad, Antonio; Berglund, Jennie; Larsbrink, Johan; Vilaplana, Francisco; Olsson, Lisbeth

2018-01-01

Galactoglucomannan (GGM) is the most abundant hemicellulose in softwood, and consists of a backbone of mannose and glucose units, decorated with galactose and acetyl moieties. GGM can be hydrolyzed into fermentable sugars, or used as a polymer in films, gels, and food additives. Endo -β-mannanases, which can be found in the glycoside hydrolase families 5 and 26, specifically cleave the mannan backbone of GGM into shorter oligosaccharides. Information on the activity and specificity of different mannanases on complex and acetylated substrates is still lacking. The aim of this work was to evaluate and compare the modes of action of two mannanases from Cellvibrio japonicus ( Cj Man5A and Cj Man26A) on a variety of mannan substrates, naturally and chemically acetylated to varying degrees, including naturally acetylated spruce GGM. Both enzymes were evaluated in terms of cleavage patterns and their ability to accommodate acetyl substitutions. Cj Man5A and Cj Man26A demonstrated different substrate preferences on mannan substrates with distinct backbone and decoration structures. Cj Man5A action resulted in higher amounts of mannotriose and mannotetraose than that of Cj Man26A, which mainly generated mannose and mannobiose as end products. Mass spectrometric analysis of products from the enzymatic hydrolysis of spruce GGM revealed that an acetylated hexotriose was the shortest acetylated oligosaccharide produced by Cj Man5A, whereas Cj Man26A generated acetylated hexobiose as well as diacetylated oligosaccharides. A low degree of native acetylation did not significantly inhibit the enzymatic action. However, a high degree of chemical acetylation resulted in decreased hydrolyzability of mannan substrates, where reduced substrate solubility seemed to reduce enzyme activity. Our findings demonstrate that the two mannanases from C. japonicus have different cleavage patterns on linear and decorated mannan polysaccharides, including the abundant and industrially important

Antiproliferative effects of TSA, PXD‑101 and MS‑275 in A2780 and MCF7 cells: Acetylated histone H4 and acetylated tubulin as markers for HDACi potency and selectivity.

PubMed

Androutsopoulos, Vasilis P; Spandidos, Demetrios A

2017-12-01

Inhibition of histone deacetylase enzymes (HDACs) has been well documented as an attractive target for the development of chemotherapeutic drugs. The present study investigated the effects of two prototype hydroxamic acid HDAC inhibitors, namely Trichostatin A (TSA) and Belinostat (PXD‑101) and the benzamide Entinostat (MS‑275) in A2780 ovarian carcinoma and MCF7 breast adenocarcinoma cells. The three HDACi inhibited the proliferation of A2780 and MCF7 cells at comparable levels, below the µM range. Enzyme inhibition assays in a cell‑free system showed that TSA was the most potent inhibitor of total HDAC enzyme activity followed by PXD‑101 and MS‑275. Incubation of A2780 and MCF7 cells with the hydroxamates TSA and PXD‑101 for 24 h resulted in a dramatic increase of acetylated tubulin induction (up to 30‑fold for TSA). In contrast to acetylated tubulin, western blot analysis and flow cytometry indicated that the induction of acetylated histone H4 was considerably smaller. The benzamide MS‑275 exhibited nearly a 2‑fold induction of acetylated histone H4 and an even smaller induction of acetylated tubulin in A2780 and MCF7 cells. Taken together, these data suggest that although the three HDACi were equipotent in inhibiting proliferation of MCF7 and A2780 cells, only the benzamide MS‑275 did not induce acetylated tubulin expression, a marker of class IIb HDACs.

Twitter journal clubs and continuing professional development: An analysis of a #MedRadJClub tweet chat.

PubMed

Bolderston, A; Watson, J; Woznitza, N; Westerink, A; Di Prospero, L; Currie, G; Beardmore, C; Hewis, J

2018-02-01

Online Twitter journal clubs are a recent and popular innovation with the potential to increase research awareness and inform practice. The medical radiation sciences' MedRadJournalClub (MJRC) is a Twitter-based event that attracts a global group of participants at the monthly chats. An analysis of a recent MedRadJournalClub discussion evaluated the perceived benefits and limitations of medical radiation practitioners participating in an online journal club. The February 2017 chat used for analysis was based on the Journal of Medical Imaging and Radiation Sciences article by Currie et al. "Twitter Journal Club in Medical Radiation Science" that examines the educational theory behind learning and evidencing professional development through MRJC and social media. The data consisted of chat tweets which were collated using the Twitter advanced search function using the #medradjclub. An initial reviewed was performed to exclude irrelevant content. A second review was then undertaken to categorize the main theme of the tweet. The data were then subjected to thematic analysis which yielded seven different categories. The main benefits included global access due to the online nature of MRJC that has facilitated networking and collaboration. Open access to recently published research was another key benefit. The character limitation of a tweet was the most common constraint, and the dynamic nature of the twitter conversation requires multi-tasking that may be difficult. Our analysis indicated that participants use MedRadJournalClub as a source of continuing professional development with some evidence that this is directly informing clinical and educational practice. Copyright © 2017 The College of Radiographers. Published by Elsevier Ltd. All rights reserved.

Deutsch, Doyc or Doitsch? Chatters as Languagers--The Case of a German-Turkish Chat Room

ERIC Educational Resources Information Center

Hinnenkamp, Volker

2008-01-01

The paper looks at the process of online-languaging of adolescents with a migratory and ethnic Turkish background in a diasporic chat room. The multiple resources and voices used are analysed. One particular example is looked at more thoroughly to illustrate the process of languaging and how it is legitimised by the chatters themselves. Finally,…

Intercomprehension between Romance Languages and the Role of English: A Study of Multilingual Chat Rooms

ERIC Educational Resources Information Center

Melo-Pfeifer, Sílvia

2014-01-01

In this article, we focus on the role English plays in multilingual chat rooms in Romance Languages. We intend to demonstrate how English, even as forbidden language in this particular setting, is a mediation and a remediation tool. Our conclusions point out that: (1) English is an constructive resource in multilingual communication; (2) it has a…

Effects of short-term hormonal replacement on learning and on basal forebrain ChAT and TrkA content in ovariectomized rats.

PubMed

Espinosa-Raya, Judith; Plata-Cruz, Noemí; Neri-Gómez, Teresa; Camacho-Arroyo, Ignacio; Picazo, Ofir

2011-02-23

It has been proposed that sex steroid hormones improve performance in some cognitive tasks by regulating the basal forebrain cholinergic function. However, the molecular basis of such influence still remains unknown. Current study analyzed the performance of ovariectomized rats in an autoshaping learning task after a short-term treatment with 17β-estradiol (E2: 4 and 40μg/kg) and/or progesterone (P4: 4mg/kg). These results were correlated with basal forebrain choline acetyltransferase (ChAT) and TrkA protein content. The high dose of E2 enhanced both acquisition in the autoshaping task and the content of ChAT and TrkA. P4 treatment increased ChAT and TrkA content without affecting performance of rats in the autoshaping learning task. Interestingly, the continuous and simultaneous administration of E2 plus P4 did not significantly modify behavioral and biochemical evaluated parameters. These results address the influence of both E2 and P4 on cholinergic and TrkA activity and suggest that the effects of ovarian hormones on cognitive performance involve basal forebrain cholinergic neurons. Copyright © 2010 Elsevier B.V. All rights reserved.

Morphological, mechanical, barrier and properties of films based on acetylated starch and cellulose from barley.

PubMed

El Halal, Shanise Lisie Mello; Colussi, Rosana; Biduski, Bárbara; Evangelho, Jarine Amaral do; Bruni, Graziella Pinheiro; Antunes, Mariana Dias; Dias, Alvaro Renato Guerra; Zavareze, Elessandra da Rosa

2017-01-01

Biodegradable films of native or acetylated starches with different concentrations of cellulose fibers (0%, 10% and 20%) were prepared. The films were characterized by morphological, mechanical, barrier, and thermal properties. The tensile strength of the acetylated starch film was lower than those of the native starch film, without fibers. The addition of fibers increased the tensile strength and decreased the elongation and the moisture of native and acetylated starches films. The acetylated starch film showed higher water solubility when compared to native starch film. The addition of cellulose fibers reduced the water solubility of the acetylated starch film. The films reinforced with cellulose fiber exhibited a higher initial decomposition temperature and thermal stability. The mechanical, barrier, solubility, and thermal properties are factors which direct the type of the film application in packaging for food products. The films elaborated with acetylated starches of low degree of substitution were not effective in a reduction of the water vapor permeability. The addition of the cellulose fiber in acetylated and native starches films can contribute to the development of more resistant films to be applied in food systems that need to maintain their integrity. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Pyrophosphate-Dependent ATP Formation from Acetyl Coenzyme A in Syntrophus aciditrophicus , a New Twist on ATP Formation

DOE PAGES

James, Kimberly L.; Ríos-Hernández, Luis A.; Wofford, Neil Q.; ...

2016-08-16

Syntrophus aciditrophicusis a model syntrophic bacterium that degrades key intermediates in anaerobic decomposition, such as benzoate, cyclohexane-1-carboxylate, and certain fatty acids, to acetate when grown with hydrogen-/formate-consuming microorganisms. ATP formation coupled to acetate production is the main source for energy conservation byS. aciditrophicus. However, the absence of homologs for phosphate acetyltransferase and acetate kinase in the genome ofS. aciditrophicusleaves it unclear as to how ATP is formed, as most fermentative bacteria rely on these two enzymes to synthesize ATP from acetyl coenzyme A (CoA) and phosphate. Here, we combine transcriptomic, proteomic, metabolite, and enzymatic approaches to show thatS. aciditrophicususes AMP-forming, acetyl-CoA synthetase (Acs1)more » for ATP synthesis from acetyl-CoA.acs1mRNA and Acs1 were abundant in transcriptomes and proteomes, respectively, ofS. aciditrophicusgrown in pure culture and coculture. Cell extracts ofS. aciditrophicushad low or undetectable acetate kinase and phosphate acetyltransferase activities but had high acetyl-CoA synthetase activity under all growth conditions tested. Both Acs1 purified fromS. aciditrophicusand recombinantly produced Acs1 catalyzed ATP and acetate formation from acetyl-CoA, AMP, and pyrophosphate. High pyrophosphate levels and a high AMP-to-ATP ratio (5.9 ± 1.4) inS. aciditrophicuscells support the operation of Acs1 in the acetate-forming direction. Thus,S. aciditrophicushas a unique approach to conserve energy involving pyrophosphate, AMP, acetyl-CoA, and an AMP-forming, acetyl-CoA synthetase. We find bacteria use two enzymes, phosphate acetyltransferase and acetate kinase, to make ATP from acetyl-CoA, while acetate-forming archaea use a single enzyme, an ADP-forming, acetyl-CoA synthetase, to synthesize ATP and acetate from acetyl-CoA.Syntrophus aciditrophicusapparently relies on a different approach to conserve energy during acetyl-CoA metabolism, as

Pyrophosphate-Dependent ATP Formation from Acetyl Coenzyme A in Syntrophus aciditrophicus , a New Twist on ATP Formation

DOE Office of Scientific and Technical Information (OSTI.GOV)

James, Kimberly L.; Ríos-Hernández, Luis A.; Wofford, Neil Q.

Syntrophus aciditrophicusis a model syntrophic bacterium that degrades key intermediates in anaerobic decomposition, such as benzoate, cyclohexane-1-carboxylate, and certain fatty acids, to acetate when grown with hydrogen-/formate-consuming microorganisms. ATP formation coupled to acetate production is the main source for energy conservation byS. aciditrophicus. However, the absence of homologs for phosphate acetyltransferase and acetate kinase in the genome ofS. aciditrophicusleaves it unclear as to how ATP is formed, as most fermentative bacteria rely on these two enzymes to synthesize ATP from acetyl coenzyme A (CoA) and phosphate. Here, we combine transcriptomic, proteomic, metabolite, and enzymatic approaches to show thatS. aciditrophicususes AMP-forming, acetyl-CoA synthetase (Acs1)more » for ATP synthesis from acetyl-CoA.acs1mRNA and Acs1 were abundant in transcriptomes and proteomes, respectively, ofS. aciditrophicusgrown in pure culture and coculture. Cell extracts ofS. aciditrophicushad low or undetectable acetate kinase and phosphate acetyltransferase activities but had high acetyl-CoA synthetase activity under all growth conditions tested. Both Acs1 purified fromS. aciditrophicusand recombinantly produced Acs1 catalyzed ATP and acetate formation from acetyl-CoA, AMP, and pyrophosphate. High pyrophosphate levels and a high AMP-to-ATP ratio (5.9 ± 1.4) inS. aciditrophicuscells support the operation of Acs1 in the acetate-forming direction. Thus,S. aciditrophicushas a unique approach to conserve energy involving pyrophosphate, AMP, acetyl-CoA, and an AMP-forming, acetyl-CoA synthetase. We find bacteria use two enzymes, phosphate acetyltransferase and acetate kinase, to make ATP from acetyl-CoA, while acetate-forming archaea use a single enzyme, an ADP-forming, acetyl-CoA synthetase, to synthesize ATP and acetate from acetyl-CoA.Syntrophus aciditrophicusapparently relies on a different approach to conserve energy during acetyl-CoA metabolism, as

Acetylated rice starches films with different levels of amylose: Mechanical, water vapor barrier, thermal, and biodegradability properties.

PubMed

Colussi, Rosana; Pinto, Vânia Zanella; El Halal, Shanise Lisie Mello; Biduski, Bárbara; Prietto, Luciana; Castilhos, Danilo Dufech; Zavareze, Elessandra da Rosa; Dias, Alvaro Renato Guerra

2017-04-15

Biodegradable films from native or acetylated starches with different amylose levels were prepared. The films were characterized according to the mechanical, water vapor barrier, thermal, and biodegradability properties. The films from acetylated high amylose starches had higher moisture content and water solubility than the native high amylose starch film. However, the acetylation did not affect acid solubility of the films, regardless of the amylose content. Films made from high and medium amylose rice starches were obtained; however low amylose rice starches, whether native or acetylated, did not form films with desirable characteristics. The acetylation decreased the tensile strength and increased the elongation of the films. The acetylated starch-based films had a lower decomposition temperature and higher thermal stability than native starch films. Acetylated starches films exhibited more rapid degradation as compared with the native starches films. Copyright © 2016 Elsevier Ltd. All rights reserved.

In vivo treatment by diallyl disulfide increases histone acetylation in rat colonocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Druesne-Pecollo, Nathalie; Chaumontet, Catherine; Pagniez, Anthony

2007-03-02

Diallyl disulfide (DADS) is an organosulfur compound from garlic which exhibits various anticarcinogenic properties including inhibition of tumor cell proliferation. DADS antiproliferative effects were previously associated with an increase in histone acetylation in two human tumor colon cell lines, suggesting that DADS-induced histone hyperacetylation could be one of the mechanisms involved in its protective properties on colon carcinogenesis. The effects of DADS on histone H4 and H3 acetylation levels were investigated in vivo in colonocytes isolated from non-tumoral rat. Administrated by intracaecal perfusion or gavage, DADS increases histone H4 and H3 acetylation in colonocytes. Moreover, data generated using cDNA expressionmore » arrays suggest that DADS could modulate the expression of a subset of genes. These results suggest the involvement of histone acetylation in modulation of gene expression by DADS in normal rat colonocytes, which might play a role in its biological effects as well as in its anticarcinogenic properties in vivo.« less

Gene encoding acetyl-coenzyme A carboxylase

DOEpatents

Roessler, P.G.; Ohlrogge, J.B.

1996-09-24

A DNA encoding an acetyl-coenzyme A carboxylase (ACCase) from a photosynthetic organism and functional derivatives are disclosed which are resistant to inhibition from certain herbicides. This gene can be placed in organisms to increase their fatty acid content or to render them resistant to certain herbicides. 5 figs.

21 CFR 172.828 - Acetylated monoglycerides.

Code of Federal Regulations, 2013 CFR

2013-04-01

... molecular distillation or by steam stripping; or (2) The direct acetylation of edible monoglycerides with acetic anhydride without the use of catalyst or molecular distillation, and with the removal by vacuum distillation, if necessary, of the acetic acid, acetic anhydride, and triacetin. (b) The food additive has a...

21 CFR 172.828 - Acetylated monoglycerides.

Code of Federal Regulations, 2012 CFR

2012-04-01

... molecular distillation or by steam stripping; or (2) The direct acetylation of edible monoglycerides with acetic anhydride without the use of catalyst or molecular distillation, and with the removal by vacuum distillation, if necessary, of the acetic acid, acetic anhydride, and triacetin. (b) The food additive has a...

Radioprotective activity of glutathione on cognitive ability in X-ray radiated tumor-bearing mice.

PubMed

Lu, Lina; Li, Zongli; Zuo, Yanhua; Zhao, Libo; Liu, Bin

2018-05-30

The use of X-ray for therapeutics always raises the problem of radiation hazards to living beings. In this research, we explored the radioprotective activity of glutathione (GSH) on cognitive ability of X-ray radiated tumor-bearing mice. Forty C57BL/6 mice were chosen to establish the GL261 glioma model and randomly divided into four groups: Model group, X-ray group, Pre-GSH group and Pos-GSH group. Morris water maze test was used to test cognitive ability. Moreover, histopathological observation of hippocampus was observed by hematoxylin and eosin (HE) staining. The protein expression of choline acetyl transferase (ChAT) was measured by western blot, simultaneously the contents of acetylcholinesterase (Ach), superoxide dismutase (SOD), methane dicarboxylic aldehyde (MDA),TNF-α and IL-6 were detected by the respective kit. There was a significant difference in X-ray group of the escape latency from the Model group (P<0.05). Besides, HE staining revealed that nucleus in hippocampus cells were pyknotic, glial cells were hyperplastic and the nerve cells were swelling in X-ray group. In X-ray group the expression of ChAT and Ache were decreased versus Model group. Finally, the cognitive ability in Pre-GSH and Pos-GSH group was enhanced than X-ray group, in which the cognitive ability of Pos-GSH group was higher than the Pre-GSH group. X-ray impaired the brain tissues and cognitive ability of tumor-bearing mice. The damages of brain tissues were alleviated by Pre-GSH and Pos-GSH protection and the efficacy of Pos-GSH protection was superior to Pre-GSH protection. Abbreviation Ach: Acetylcholinesterase; GSH: Glutathione; HE: Hematoxylin and eosin; MDA: methane dicarboxylic aldehyde; SOD: Superoxide dismutase; TV: Tumor volume; TW: Tumor weight.

[Distribution of acetylator phenotypes in the normal Moscow city population and in chronic alcoholism].

PubMed

Lil'in, E T; Korsunskaia, M P; Meksin, V A; Drozdov, E S; Nazarov, V V

1984-09-01

The distribution of acetylator phenotypes was studied in 169 normal individuals of Moscow Russian population and 75 inhabitants of Moscow suffering from chronic alcoholism. Polymorphism was found by means of acetylation in both groups studied. The proportion of repeatability of rapid and slow acetylators amounts to 48 and 52% among normal individuals, 44 and 56% among those who suffer from chronic alcoholism. The comparative analyses of such repeatability within the classes resulted in authentic increase of the rate of rapid acetylators among the chronic alcoholics (chi 2 = 18.32; p less than 0.01); in comparison with normal individual groups, (the modes being in classes 50-60% and 80-90%, with the antimode 70-80%), a shift of one of the modes from the 50-60% class into the 60-70% class was traced among diseased individuals. It is supposed that chronic alcohol consumption stimulates the process of acetylation; possible reasons for this stimulation are discussed.

Immunomodulatory effects of an acetylated Cyclocarya paliurus polysaccharide on murine macrophages RAW264.7.

PubMed

Liu, Xin; Xie, Jianhua; Jia, Shuo; Huang, Lixin; Wang, Zhijun; Li, Chang; Xie, Mingyong

2017-05-01

Polysaccharides (CP) extracted from the leaves of Cyclocarya paliurus (C. paliurus) have been shown to possess a variety of biological activities. In present study, CP was successfully modified to obtain its acetylated derivative Ac-CP. Its potential immunomodulatory activities on RAW264.7 macrophages were investigated. Results showed that the acetylated polysaccharide Ac-CP could significantly stimulate macrophage proliferation, its actions were significantly stronger than that of the corresponding unmodified polysaccharide, CP. Meanwhile, the NO production activities of macrophages were not significantly enhanced by Ac-CP compared to CP group. In addition, both the phagocytic activity and levels of cytokines TNF-a, IL-1β and IL-6 were enhanced in the RAW264.7 macrophages by stimulation of Ac-CP. These results indicated that the acetylated derivative Ac-CP could enhance the activation of peritoneal macrophages, and acetylation modification can enhance the immunomodulation function of CP, indicating the potential application of acetylated polysaccharide as an immunotherapeutic adjuvant. Copyright © 2017 Elsevier B.V. All rights reserved.

Determination of the structure of lecithins via the formation of acetylated 1,2-diglycerides.

PubMed

Privett, O S; Nutter, L J

1967-03-01

A detailed procedure for quantitative determinations of molecular species of lecithins is described and applied to several lecithins isolated from natural sources. The method is based on the conversion of lecithin to acetylated 1,2-diglycerides and analysis of these compounds by methodology used for the determination of triglyceride structure.The preparation of the acetylated 1,2-diglycerides was carried out via hydrolysis with phospholipase C and acetylation of the resultant, 1,2-diglycerides with pyridine-acetic anhydride. Preparation of acetylated 1,2-diglycerides from lecithin by acetolysis with acetic acid-acetic anhydride was shown to be accompanied by intermolecular as well as intramolecular rearrangement of the fatty acids.The structure of the acetylated 1,2-diglycerides was determined by a combination of argentation-TLC and pancreatic lipase hydrolysis using internal standards for quantification. The method was applied to lecithins isolated from milk serum, egg, soybean, safflower seed and wheat germ lipids.

Evidence for lysine acetylation in the coat protein of a polerovirus.

PubMed

Cilia, Michelle; Johnson, Richard; Sweeney, Michelle; DeBlasio, Stacy L; Bruce, James E; MacCoss, Michael J; Gray, Stewart M

2014-10-01

Virions of the RPV strain of Cereal yellow dwarf virus-RPV were purified from infected oat tissue and analysed by MS. Two conserved residues, K147 and K181, in the virus coat protein, were confidently identified to contain epsilon-N-acetyl groups. While no functional data are available for K147, K181 lies within an interfacial region critical for virion assembly and stability. The signature immonium ion at m/z 126.0919 demonstrated the presence of N-acetyllysine, and the sequence fragment ions enabled an unambiguous assignment of the epsilon-N-acetyl modification on K181. We hypothesize that selection favours acetylation of K181 in a fraction of coat protein monomers to stabilize the capsid by promoting intermonomer salt bridge formation.

The Usability of WeChat as a Mobile and Interactive Medium in Student-Centered Medical Teaching

ERIC Educational Resources Information Center

Wang, Juan; Gao, Furong; Li, Jiao; Zhang, Jieping; Li, Siguang; Xu, Guo-tong; Xu, Lei; Chen, Jianjun; Lu, Lixia

2017-01-01

Biochemistry and cellular biology courses for medical students at Tongji University include the assessment that provides students with feedback to enhance their learning, which is a type of formative assessment. However, frequent instant feedback and guidance for students is often absent or inconsistently included in the teaching process. WeChat,…

Combining Live Video and Audio Broadcasting, Synchronous Chat, and Asynchronous Open Forum Discussions in Distance Education

ERIC Educational Resources Information Center

Teng, Tian-Lih; Taveras, Marypat

2004-01-01

This article outlines the evolution of a unique distance education program that began as a hybrid--combining face-to-face instruction with asynchronous online teaching--and evolved to become an innovative combination of synchronous education using live streaming video, audio, and chat over the Internet, blended with asynchronous online discussions…

Changes in Reference Question Complexity Following the Implementation of a Proactive Chat System: Implications for Practice

ERIC Educational Resources Information Center

Maloney, Krisellen; Kemp, Jan H.

2015-01-01

There has been longstanding debate about whether the level of complexity of questions received at reference desks and via online chat services requires a librarian's expertise. Continued decreases in the number and complexity of reference questions have all but ended the debate; many academic libraries no longer staff service points with…

The Effect of Acetyl-L-Carnitine Administration on Persons with Down Syndrome

ERIC Educational Resources Information Center

Pueschel, Siegfried M.

2006-01-01

Since previous investigations reported improvements in cognition of patients with dementia after acetyl-L-carnitine therapy and since there is an increased risk for persons with Down syndrome to develop Alzheimer disease, this study was designed to investigate the effect of acetyl-L-carnitine administration on neurological, intellectual, and…

Temporal Regulation of the Bacillus subtilis Acetylome and Evidence for a Role of MreB Acetylation in Cell Wall Growth

PubMed Central

Carabetta, Valerie J.; Greco, Todd M.; Tanner, Andrew W.

2016-01-01

ABSTRACT Nε-Lysine acetylation has been recognized as a ubiquitous regulatory posttranslational modification that influences a variety of important biological processes in eukaryotic cells. Recently, it has been realized that acetylation is also prevalent in bacteria. Bacteria contain hundreds of acetylated proteins, with functions affecting diverse cellular pathways. Still, little is known about the regulation or biological relevance of nearly all of these modifications. Here we characterize the cellular growth-associated regulation of the Bacillus subtilis acetylome. Using acetylation enrichment and quantitative mass spectrometry, we investigate the logarithmic and stationary growth phases, identifying over 2,300 unique acetylation sites on proteins that function in essential cellular pathways. We determine an acetylation motif, EK(ac)(D/Y/E), which resembles the eukaryotic mitochondrial acetylation signature, and a distinct stationary-phase-enriched motif. By comparing the changes in acetylation with protein abundances, we discover a subset of critical acetylation events that are temporally regulated during cell growth. We functionally characterize the stationary-phase-enriched acetylation on the essential shape-determining protein MreB. Using bioinformatics, mutational analysis, and fluorescence microscopy, we define a potential role for the temporal acetylation of MreB in restricting cell wall growth and cell diameter. IMPORTANCE The past decade highlighted Nε-lysine acetylation as a prevalent posttranslational modification in bacteria. However, knowledge regarding the physiological importance and temporal regulation of acetylation has remained limited. To uncover potential regulatory roles for acetylation, we analyzed how acetylation patterns and abundances change between growth phases in B. subtilis. To demonstrate that the identification of cell growth-dependent modifications can point to critical regulatory acetylation events, we further characterized

Temporal Regulation of the Bacillus subtilis Acetylome and Evidence for a Role of MreB Acetylation in Cell Wall Growth.

PubMed

Carabetta, Valerie J; Greco, Todd M; Tanner, Andrew W; Cristea, Ileana M; Dubnau, David

2016-05-01

N ε -Lysine acetylation has been recognized as a ubiquitous regulatory posttranslational modification that influences a variety of important biological processes in eukaryotic cells. Recently, it has been realized that acetylation is also prevalent in bacteria. Bacteria contain hundreds of acetylated proteins, with functions affecting diverse cellular pathways. Still, little is known about the regulation or biological relevance of nearly all of these modifications. Here we characterize the cellular growth-associated regulation of the Bacillus subtilis acetylome. Using acetylation enrichment and quantitative mass spectrometry, we investigate the logarithmic and stationary growth phases, identifying over 2,300 unique acetylation sites on proteins that function in essential cellular pathways. We determine an acetylation motif, EK(ac)(D/Y/E), which resembles the eukaryotic mitochondrial acetylation signature, and a distinct stationary-phase-enriched motif. By comparing the changes in acetylation with protein abundances, we discover a subset of critical acetylation events that are temporally regulated during cell growth. We functionally characterize the stationary-phase-enriched acetylation on the essential shape-determining protein MreB. Using bioinformatics, mutational analysis, and fluorescence microscopy, we define a potential role for the temporal acetylation of MreB in restricting cell wall growth and cell diameter. The past decade highlighted N ε -lysine acetylation as a prevalent posttranslational modification in bacteria. However, knowledge regarding the physiological importance and temporal regulation of acetylation has remained limited. To uncover potential regulatory roles for acetylation, we analyzed how acetylation patterns and abundances change between growth phases in B. subtilis . To demonstrate that the identification of cell growth-dependent modifications can point to critical regulatory acetylation events, we further characterized MreB, the cell

The Global Acetylome of the Human Pathogen Vibrio cholerae V52 Reveals Lysine Acetylation of Major Transcriptional Regulators

PubMed Central

Jers, Carsten; Ravikumar, Vaishnavi; Lezyk, Mateusz; Sultan, Abida; Sjöling, Åsa; Wai, Sun N.; Mijakovic, Ivan

2018-01-01

Protein lysine acetylation is recognized as an important reversible post translational modification in all domains of life. While its primary roles appear to reside in metabolic processes, lysine acetylation has also been implicated in regulating pathogenesis in bacteria. Several global lysine acetylome analyses have been carried out in various bacteria, but thus far there have been no reports of lysine acetylation taking place in the important human pathogen Vibrio cholerae. In this study, we analyzed the lysine acetylproteome of the human pathogen V. cholerae V52. By applying a combination of immuno-enrichment of acetylated peptides and high resolution mass spectrometry, we identified 3,402 acetylation sites on 1,240 proteins. Of the acetylated proteins, more than half were acetylated on two or more sites. As reported for other bacteria, we observed that many of the acetylated proteins were involved in metabolic and cellular processes and there was an over-representation of acetylated proteins involved in protein synthesis. Of interest, we demonstrated that many global transcription factors such as CRP, H-NS, IHF, Lrp and RpoN as well as transcription factors AphB, TcpP, and PhoB involved in direct regulation of virulence in V. cholerae were acetylated. In conclusion, this is the first global protein lysine acetylome analysis of V. cholerae and should constitute a valuable resource for in-depth studies of the impact of lysine acetylation in pathogenesis and other cellular processes. PMID:29376036

Postmortem Toxicology Findings of Acetyl Fentanyl, Fentanyl, and Morphine in Heroin Fatalities in Tampa, Florida

PubMed Central

Pearson, Julia; Poklis, Justin; Poklis, Alphonse; Wolf, Carl; Mainland, Mary; Hair, Laura; Devers, Kelly; Chrostowski, Leszek; Arbefeville, Elise; Merves, Michele

2017-01-01

In the last two years, an epidemic of 40 fatal heroin overdose cases has occurred in the Tampa area of Florida. Of these cases, 14 involved fentanyl and acetyl fentanyl. Victim demographics, case histories, toxicology findings, and causes and manners of death for all 40 deaths are presented. In 26 deaths in which acetyl fentanyl or fentanyl were not involved, free and total peripheral blood morphine concentrations were consistent with fatal heroin intoxications, averaging 0.16 mg/L and 0.35 mg/L, respectively. In the heroin cases with fentanyl present (n=7), the average free morphine concentration was 0.040 mg/L, the average total morphine concentration was 0.080 mg/L, and the average fentanyl concentration was 0.012 mg/L. In the cases with heroin, fentanyl, and acetyl fentanyl (n=3), the average free morphine concentration was 0.010 mg/L, the average total morphine concentration was 0.030 mg/L, the average fentanyl concentration was 0.018 mg/L, and the average acetyl fentanyl concentration was 0.008 mg/L. In the cases involving only acetyl fentanyl (without heroin or fentanyl, n=4), the average acetyl fentanyl concentration was 0.47 mg/L and the average acetyl norfentanyl concentration was 0.053 mg/L. The presented cases, with associated drug concentrations, case histories, demographics, and causes and manners of death may help provide assistance with the interpretation of the postmortem findings. Based on case circumstances, autopsy results, and toxicology results, it is evident that fentanyl and/or acetyl fentanyl, when present, contributed to the cause of death. PMID:29034049

Distribution of O-Acetylated Sialic Acids among Target Host Tissues for Influenza Virus

PubMed Central

Barnard, Karen N.; Ossiboff, Robert J.; Khedri, Zahra; Feng, Kurtis H.; Yu, Hai; Chen, Xi; Varki, Ajit

2017-01-01

ABSTRACT Sialic acids (Sias) are important glycans displayed on the cells and tissues of many different animals and are frequent targets for binding and modification by pathogens, including influenza viruses. Influenza virus hemagglutinins bind Sias during the infection of their normal hosts, while the encoded neuraminidases and/or esterases remove or modify the Sia to allow virion release or to prevent rebinding. Sias naturally occur in a variety of modified forms, and modified Sias can alter influenza virus host tropisms through their altered interactions with the viral glycoproteins. However, the distribution of modified Sia forms and their effects on pathogen-host interactions are still poorly understood. Here we used probes developed from viral Sia-binding proteins to detect O-acetylated (4-O-acetyl, 9-O-acetyl, and 7,9-O-acetyl) Sias displayed on the tissues of some natural or experimental hosts for influenza viruses. These modified Sias showed highly variable displays between the hosts and tissues examined. The 9-O-acetyl (and 7,9-) modified Sia forms were found on cells and tissues of many hosts, including mice, humans, ferrets, guinea pigs, pigs, horses, dogs, as well as in those of ducks and embryonated chicken egg tissues and membranes, although in variable amounts. The 4-O-acetyl Sias were found in the respiratory tissues of fewer animals, being primarily displayed in the horse and guinea pig, but were not detected in humans or pigs. The results suggest that these Sia variants may influence virus tropisms by altering and selecting their cell interactions. IMPORTANCE Sialic acids (Sias) are key glycans that control or modulate many normal cell and tissue functions while also interacting with a variety of pathogens, including many different viruses. Sias are naturally displayed in a variety of different forms, with modifications at several positions that can alter their functional interactions with pathogens. In addition, Sias are often modified or

Nitric Oxide Modulates Histone Acetylation at Stress Genes by Inhibition of Histone Deacetylases.

PubMed

Mengel, Alexander; Ageeva, Alexandra; Georgii, Elisabeth; Bernhardt, Jörg; Wu, Keqiang; Durner, Jörg; Lindermayr, Christian

2017-02-01

Histone acetylation, which is an important mechanism to regulate gene expression, is controlled by the opposing action of histone acetyltransferases and histone deacetylases (HDACs). In animals, several HDACs are subjected to regulation by nitric oxide (NO); in plants, however, it is unknown whether NO affects histone acetylation. We found that treatment with the physiological NO donor S-nitrosoglutathione (GSNO) increased the abundance of several histone acetylation marks in Arabidopsis (Arabidopsis thaliana), which was strongly diminished in the presence of the NO scavenger 2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide. This increase was likely triggered by NO-dependent inhibition of HDAC activity, since GSNO and S-nitroso-N-acetyl-dl-penicillamine significantly and reversibly reduced total HDAC activity in vitro (in nuclear extracts) and in vivo (in protoplasts). Next, genome-wide H3K9/14ac profiles in Arabidopsis seedlings were generated by chromatin immunoprecipitation sequencing, and changes induced by GSNO, GSNO/2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide or trichostatin A (an HDAC inhibitor) were quantified, thereby identifying genes that display putative NO-regulated histone acetylation. Functional classification of these genes revealed that many of them are involved in the plant defense response and the abiotic stress response. Furthermore, salicylic acid, which is the major plant defense hormone against biotrophic pathogens, inhibited HDAC activity and increased histone acetylation by inducing endogenous NO production. These data suggest that NO affects histone acetylation by targeting and inhibiting HDAC complexes, resulting in the hyperacetylation of specific genes. This mechanism might operate in the plant stress response by facilitating the stress-induced transcription of genes. © 2017 American Society of Plant Biologists. All Rights Reserved.

Evaluation of acetylated moth bean starch as a carrier for controlled drug delivery

PubMed Central

Singh, Akhilesh V.; Nath, Lila K.

2012-01-01

The present investigation concerns with the development of controlled release tablets of lamivudine using acetylated moth bean starch. The acetylated starch was synthesized with acetic anhydride in pyridine medium. The acetylated moth bean starch was tested for acute toxicity and drug–excipient compatibility study. The formulations were evaluated for physical characteristics like hardness, friability, % drug content and weight variations. The in vitro release study showed that the optimized formulation exhibited highest correlation (R) value in case of Higuchi kinetic model and the release mechanism study proved that the formulation showed a combination of diffusion and erosion process. There was a significant difference in the pharmacokinetic parameters (Tmax, Cmax, AUC, Vd, T1/2 and MDT) of the optimized formulation as compared to the marketed conventional tablet Lamivir®, which proved controlled release potential of acetylated moth bean starch. PMID:22210486

Acetylome Profiling Reveals Extensive Lysine Acetylation of the Fatty Acid Metabolism Pathway in the Diatom Phaeodactylum tricornutum.

PubMed

Chen, Zhuo; Luo, Ling; Chen, Runfa; Hu, Hanhua; Pan, Yufang; Jiang, Haibo; Wan, Xia; Jin, Hu; Gong, Yangmin

2018-03-01

N ε -lysine acetylation represents a highly dynamic and reversibly regulated post-translational modification widespread in almost all organisms, and plays important roles for regulation of protein function in diverse metabolic pathways. However, little is known about the role of lysine acetylation in photosynthetic eukaryotic microalgae. We integrated proteomic approaches to comprehensively characterize the lysine acetylome in the model diatom Phaeodactylum tricornutum In total, 2324 acetylation sites from 1220 acetylated proteins were identified, representing the largest data set of the lysine acetylome in plants to date. Almost all enzymes involved in fatty acid synthesis were found to be lysine acetylated. Six putative lysine acetylation sites were identified in a plastid-localized long-chain acyl-CoA synthetase. Site-directed mutagenesis and site-specific incorporation of N-acetyllysine in acyl-CoA synthetase show that acetylation at K407 and K425 increases its enzyme activity. Moreover, the nonenzymatically catalyzed overall hyperacetylation of acyl-CoA synthetase by acetyl-phosphate can be effectively deacetylated and reversed by a sirtuin-type NAD + -dependent deacetylase with subcellular localization of both the plastid and nucleus in Phaeodactylum This work indicates the regulation of acyl-CoA synthetase activity by site-specific lysine acetylation and highlights the potential regulation of fatty acid metabolism by lysine actetylation in the plastid of the diatom Phaeodactylum . © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Effect of Acetyl Group on Mechanical Properties of Chitin/Chitosan Nanocrystal: A Molecular Dynamics Study

PubMed Central

Cui, Junhe; Yu, Zechuan; Lau, Denvid

2016-01-01

Chitin fiber is the load-bearing component in natural chitin-based materials. In these materials, chitin is always partially deacetylated to different levels, leading to diverse material properties. In order to understand how the acetyl group enhances the fracture resistance capability of chitin fiber, we constructed atomistic models of chitin with varied acetylation degree and analyzed the hydrogen bonding pattern, fracture, and stress-strain behavior of these models. We notice that the acetyl group can contribute to the formation of hydrogen bonds that can stabilize the crystalline structure. In addition, it is found that the specimen with a higher acetylation degree presents a greater resistance against fracture. This study describes the role of the functional group, acetyl groups, in crystalline chitin. Such information could provide preliminary understanding of nanomaterials when similar functional groups are encountered. PMID:26742033

Characterization of O-acetylation in sialoglycans by MALDI-MS using a combination of methylamidation and permethylation

NASA Astrophysics Data System (ADS)

Wu, Zhaoguan; Li, Henghui; Zhang, Qiwei; Liu, Xin; Zheng, Qi; Li, Jianjun

2017-04-01

O-Acetylation of sialic acid in protein N-glycans is an important modification and can occur at either 4-, 7-, 8- or 9-position in various combinations. This modification is usually labile under alkaline reaction conditions. Consequently, a permethylation-based analytical method, which has been widely used in glycomics studies, is not suitable for profiling O-acetylation of sialic acids due to the harsh reaction conditions. Alternatively, methylamidation can be used for N-glycan analysis without affecting the base-labile modification of sialic acid. In this report, we applied both permethylation and methylamidation approaches to the analysis of O-acetylation in sialic acids. It has been demonstrated that methylamidation not only stabilizes sialic acids during MALDI processing but also allow for characterization of their O-acetylation pattern. In addition, LC-MS/MS experiments were carried out to distinguish between the O-acetylated glycans with potential isomeric structures. The repeatability of methylamidation was examined to evaluate the applicability of the approach to profiling of O-acetylation in sialic acids. In conclusion, the combination of methylamidation and permethylation methodology is a powerful MALDI-TOF MS-based tool for profiling O-acetylation in sialic acids applicable to screening of N-glycans.

Post-translational Acetylation of MbtA Modulates Mycobacterial Siderophore Biosynthesis.

PubMed

Vergnolle, Olivia; Xu, Hua; Tufariello, JoAnn M; Favrot, Lorenza; Malek, Adel A; Jacobs, William R; Blanchard, John S

2016-10-14

Iron is an essential element for life, but its soluble form is scarce in the environment and is rarer in the human body. Mtb (Mycobacterium tuberculosis) produces two aryl-capped siderophores, mycobactin (MBT) and carboxymycobactin (cMBT), to chelate intracellular iron. The adenylating enzyme MbtA catalyzes the first step of mycobactin biosynthesis in two half-reactions: activation of the salicylic acid as an acyl-adenylate and ligation onto the acyl carrier protein (ACP) domain of MbtB to form covalently salicylated MbtB-ACP. We report the first apo-MbtA structure from Mycobacterium smegmatis at 2.3 Å. We demonstrate here that MbtA activity can be reversibly, post-translationally regulated by acetylation. Indeed the mycobacterial Pat (protein lysine acetyltransferase), Rv0998, specifically acetylates MbtA on lysine 546, in a cAMP-dependent manner, leading to enzyme inhibition. MbtA acetylation can be reversed by the NAD + -dependent DAc (deacetyltransferase), Rv1151c. Deletion of Pat and DAc genes in Mtb revealed distinct phenotypes for strains lacking one or the other gene at low pH and limiting iron conditions. This study establishes a direct connection between the reversible acetylation system Pat/DAc and the ability of Mtb to adapt in limited iron conditions, which is critical for mycobacterial infection. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

NeuA sialic acid O-acetylesterase activity modulates O-acetylation of capsular polysaccharide in group B Streptococcus.

PubMed

Lewis, Amanda L; Cao, Hongzhi; Patel, Silpa K; Diaz, Sandra; Ryan, Wesley; Carlin, Aaron F; Thon, Vireak; Lewis, Warren G; Varki, Ajit; Chen, Xi; Nizet, Victor

2007-09-21

Group B Streptococcus (GBS) is a common cause of neonatal sepsis and meningitis. A major GBS virulence determinant is its sialic acid (Sia)-capped capsular polysaccharide. Recently, we discovered the presence and genetic basis of capsular Sia O-acetylation in GBS. We now characterize a GBS Sia O-acetylesterase that modulates the degree of GBS surface O-acetylation. The GBS Sia O-acetylesterase operates cooperatively with the GBS CMP-Sia synthetase, both part of a single polypeptide encoded by the neuA gene. NeuA de-O-acetylation of free 9-O-acetyl-N-acetylneuraminic acid (Neu5,9Ac(2)) was enhanced by CTP and Mg(2+), the substrate and co-factor, respectively, of the N-terminal GBS CMP-Sia synthetase domain. In contrast, the homologous bifunctional NeuA esterase from Escherichia coli K1 did not display cofactor dependence. Further analyses showed that in vitro, GBS NeuA can operate via two alternate enzymatic pathways: de-O-acetylation of Neu5,9Ac(2) followed by CMP activation of Neu5Ac or activation of Neu5,9Ac(2) followed by de-O-acetylation of CMP-Neu5,9Ac(2). Consistent with in vitro esterase assays, genetic deletion of GBS neuA led to accumulation of intracellular O-acetylated Sias, and overexpression of GBS NeuA reduced O-acetylation of Sias on the bacterial surface. Site-directed mutagenesis of conserved asparagine residue 301 abolished esterase activity but preserved CMP-Sia synthetase activity, as evidenced by hyper-O-acetylation of capsular polysaccharide Sias on GBS expressing only the N301A NeuA allele. These studies demonstrate a novel mechanism regulating the extent of capsular Sia O-acetylation in intact bacteria and provide a genetic strategy for manipulating GBS O-acetylation in order to explore the role of this modification in GBS pathogenesis and immunogenicity.

First observation of N-acetyl leucine and N-acetyl isoleucine in diabetic patient hair and quantitative analysis by UPLC-ESI-MS/MS.

PubMed

Min, Jun Zhe; Tomiyasu, Yuki; Morotomi, Takashi; Jiang, Ying-Zi; Li, Gao; Shi, Qing; Yu, Hai-Fu; Inoue, Koichi; Todoroki, Kenichiro; Toyo'oka, Toshimasa

2015-04-15

Type 2 diabetes patients (DP) have significantly higher plasma levels of valine, leucine, isoleucine and alanine than the controls. Specific amino acids may acutely and chronically regulate insulin secretion from the pancreatic β-cells. We recently identified a metabolic signature of N-acetyl leucine (Ac-Leu) that strongly predicts diabetes development in mice hair. The Ac-Leu appears to be a potential biomarker candidate related to diabetes. However, the determination of Ac-Leu in human hair has not been reported. We measured the Ac-Leu, and its structure is similar to N-acetyl isoleucine (Ac-Ile) in human hair by ultra-performance liquid chromatography (UPLC) with electrospray ionization tandem mass spectrometry (ESI-MS/MS). The developed method was applied to the determination of Ac-Leu and Ac-Ile in the hair of healthy volunteers (HV) and DP. Ac-Leu, Ac-Ile and N-acetyl norleucine (Ac-Nle, IS) were extracted from human hair samples by a micropulverized extraction procedure, then separated on a C18 column by isocratic elution of acetonitrile-0.1% formic acid in water:0.1% formic acid (14:86, vol./vol.). MRM using the fragmentation transitions of m/z 174.1→86.1 in the positive ESI mode was performed to quantify the N-acetyl leucine, N-acetyl isoleucine and IS. Ac-Leu, Ac-Ile and Ac-Nle in the human hair samples were completely separated by isocratic elution of a 5.0 min duration wash program using a reversed-phase column, and sensitively detected by LC-MS/MS in the ESI(+) MRM mode. The amounts of Ac-Leu and Ac-Ile in the hairs of HV and DP were determined. When comparing the concentrations between DP and those from HV, a statistically significant correlation was observed for the Ac-Leu (p<0.001) and Ac-Ile (p<0.01). The proposed method is useful for the determination of Ac-Leu and Ac-Ile in the hairs of DP and HV. Human hair may serve as a noninvasive biosample for the diagnosis of diabetes. Crown Copyright © 2015. Published by Elsevier B.V. All rights

21 CFR 573.130 - Aminoglycoside 3′-phospho- transferase II.

Code of Federal Regulations, 2012 CFR

2012-04-01

... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.130 Aminoglycoside 3′-phospho- transferase II. The food additive aminoglycoside 3′-phosphotransferase II may be safely used in the development of...

21 CFR 573.130 - Aminoglycoside 3′-phospho- transferase II.

Code of Federal Regulations, 2010 CFR

2010-04-01

... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.130 Aminoglycoside 3′-phospho- transferase II. The food additive aminoglycoside 3′-phosphotransferase II may be safely used in the development of...

21 CFR 573.130 - Aminoglycoside 3′-phospho- transferase II.

Code of Federal Regulations, 2013 CFR

2013-04-01

... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.130 Aminoglycoside 3′-phospho- transferase II. The food additive aminoglycoside 3′-phosphotransferase II may be safely used in the development of...

21 CFR 573.130 - Aminoglycoside 3′-phospho- transferase II.

Code of Federal Regulations, 2011 CFR

2011-04-01

... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.130 Aminoglycoside 3′-phospho- transferase II. The food additive aminoglycoside 3′-phosphotransferase II may be safely used in the development of...

21 CFR 573.130 - Aminoglycoside 3′-phospho- transferase II.

Code of Federal Regulations, 2014 CFR

2014-04-01

... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.130 Aminoglycoside 3′-phospho- transferase II. The food additive aminoglycoside 3′-phosphotransferase II may be safely used in the development of...

Conformational studies of bacterial peptidoglycan: structure and stereochemistry of N-acetyl-β- D-glucosamine and N-acetyl-β- D-muramic acid

NASA Astrophysics Data System (ADS)

Yadav, P. N. S.; Rai, D. K.; Yadav, J. S.

1989-03-01

The energies of various conformations of N-acetyl-β- D-glucosamine (NAG) and its 3-O- D-lactic acid derivative N-acetyl-β- D-muramic acid (NAM) have been calculated by geometry optimization using the molecular mechanics program MM2. The geometries of these systems have been analyzed in the light of ring torsion, bond lengths, bond angles and conformational states of side groups of the pyranosyl ring and compared with available experimental data of similar pyranose derivatives. The present study indicates the presence of hydrogen bonds to stabilize the side group conformations. Discrepancies with experimental data that are seen in a few cases are ascribed to the nature of the side groups and their geometry.

Lysine acetylation sites in bovine foamy virus transactivator BTas are important for its DNA binding activity.

PubMed

Chang, Rui; Tan, Juan; Xu, Fengwen; Han, Hongqi; Geng, Yunqi; Li, Yue; Qiao, Wentao

2011-09-15

Cellular acetylation signaling is important for viral gene regulation, particularly during the transactivation of retroviruses. The regulatory protein of bovine foamy virus (BFV), BTas, is a transactivator that augments viral gene transcription from both the long terminal repeat (LTR) promoter and the internal promoter (IP). In this study, we report that the histone acetyltransferase (HAT), p300, specifically acetylates BTas both in vivo and in vitro. Further studies demonstrated that BTas acetylation markedly enhances its transactivation activity. Mutagenesis analysis identified three lysines at positions 66, 109 and 110 in BTas that are acetylated by p300. The K110R mutant lost its binding to BFV promoter as well as its ability to activate BFV promoter. The acetylation of K66 and K109 may contribute to increased BTas binding ability. These results suggest that the p300-acetylated lysines of BTas are important for transactivation of BFV promoters and therefore have an important role in BFV replication. Copyright © 2011 Elsevier Inc. All rights reserved.

Succinyl-CoA:(R)-Benzylsuccinate CoA-Transferase: an Enzyme of the Anaerobic Toluene Catabolic Pathway in Denitrifying Bacteria†

PubMed Central

Leutwein, Christina; Heider, Johann

2001-01-01

Anaerobic microbial toluene catabolism is initiated by addition of fumarate to the methyl group of toluene, yielding (R)-benzylsuccinate as first intermediate, which is further metabolized via β-oxidation to benzoyl-coenzyme A (CoA) and succinyl-CoA. A specific succinyl-CoA:(R)-benzylsuccinate CoA-transferase activating (R)-benzylsuccinate to the CoA-thioester was purified and characterized from Thauera aromatica. The enzyme is fully reversible and forms exclusively the 2-(R)-benzylsuccinyl-CoA isomer. Only some close chemical analogs of the substrates are accepted by the enzyme: succinate was partially replaced by maleate or methylsuccinate, and (R)-benzylsuccinate was replaced by methylsuccinate, benzylmalonate, or phenylsuccinate. In contrast to all other known CoA-transferases, the enzyme consists of two subunits of similar amino acid sequences and similar sizes (44 and 45 kDa) in an α2β2 conformation. Identity of the subunits with the products of the previously identified toluene-induced bbsEF genes was confirmed by determination of the exact masses via electrospray-mass spectrometry. The deduced amino acid sequences resemble those of only two other characterized CoA-transferases, oxalyl-CoA:formate CoA-transferase and (E)-cinnamoyl-CoA:(R)-phenyllactate CoA-transferase, which represent a new family of CoA-transferases. As suggested by kinetic analysis, the reaction mechanism of enzymes of this family apparently involves formation of a ternary complex between the enzyme and the two substrates. PMID:11418570

Structure Elucidation of New Acetylated Saponins, Lessoniosides A, B, C, D, and E, and Non-Acetylated Saponins, Lessoniosides F and G, from the Viscera of the Sea Cucumber Holothuria lessoni

PubMed Central

Bahrami, Yadollah; Franco, Christopher M. M.

2015-01-01

Sea cucumbers produce numerous compounds with a wide range of chemical structural diversity. Among these, saponins are the most diverse and include sulfated, non-sulfated, acetylated and methylated congeners with different aglycone and sugar moieties. In this study, MALDI and ESI tandem mass spectrometry, in the positive ion mode, were used to elucidate the structure of new saponins extracted from the viscera of H. lessoni. Fragmentation of the aglycone provided structural information on the presence of the acetyl group. The presence of the O-acetyl group was confirmed by observing the mass transition of 60 u corresponding to the loss of a molecule of acetic acid. Ion fingerprints from the glycosidic cleavage provided information on the mass of the aglycone (core), and the sequence and type of monosaccharides that constitute the sugar moiety. The tandem mass spectra of the saponin precursor ions [M + Na]+ provided a wealth of detailed structural information on the glycosidic bond cleavages. As a result, and in conjunction with existing literature, we characterized the structure of five new acetylated saponins, Lessoniosides A–E, along with two non-acetylated saponins Lessoniosides F and G at m/z 1477.7, which are promising candidates for future drug development. The presented strategy allows a rapid, reliable and complete analysis of native saponins. PMID:25603350

Mechanistic insights into the regulation of metabolic enzymes by acetylation

PubMed Central

2012-01-01

The activity of metabolic enzymes is controlled by three principle levels: the amount of enzyme, the catalytic activity, and the accessibility of substrates. Reversible lysine acetylation is emerging as a major regulatory mechanism in metabolism that is involved in all three levels of controlling metabolic enzymes and is altered frequently in human diseases. Acetylation rivals other common posttranslational modifications in cell regulation not only in the number of substrates it modifies, but also the variety of regulatory mechanisms it facilitates. PMID:22826120

Hepatic drug acetylation and oxidation: effects of aging in man.

PubMed Central

Farah, F; Taylor, W; Rawlins, M D; James, O

1977-01-01

The half lives of acetanilide and isoniazid ("model" substrates for oxidation and acetylation respectively) were measured in populations of young (aged 20-35 years) and elderly (aged over 65 years) people. Whereas acetanilide half lives were significantly longer in the elderly, isoniazid half lives were distributed similarly in both populations. The results suggest that liver function does not decline uniformly with age and that heterozygotes for acetylation do not possess survival advantages during their middle years of life. PMID:871823

Engineering a synthetic pathway in cyanobacteria for isopropanol production directly from carbon dioxide and light.

PubMed

Kusakabe, Tamami; Tatsuke, Tsuneyuki; Tsuruno, Keigo; Hirokawa, Yasutaka; Atsumi, Shota; Liao, James C; Hanai, Taizo

2013-11-01

Production of alternate fuels or chemicals directly from solar energy and carbon dioxide using engineered cyanobacteria is an attractive method to reduce petroleum dependency and minimize carbon emissions. Here, we constructed a synthetic pathway composed of acetyl-CoA acetyl transferase (encoded by thl), acetoacetyl-CoA transferase (encoded by atoAD), acetoacetate decarboxylase (encoded by adc) and secondary alcohol dehydrogenase (encoded by adh) in Synechococcus elongatus strain PCC 7942 to produce isopropanol. The enzyme-coding genes, heterogeneously originating from Clostridium acetobutylicum ATCC 824 (thl and adc), Escherichia coli K-12 MG1655 (atoAD) and Clostridium beijerinckii (adh), were integrated into the S. elongatus genome. Under the optimized production conditions, the engineered cyanobacteria produced 26.5 mg/L of isopropanol after 9 days. © 2013 Published by Elsevier Inc.

New spectrophotometric and radiochemical assays for acetyl-CoA: arylamine N-acetyltransferase applicable to a variety of arylamines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andres, H.H.; Klem, A.J.; Szabo, S.M.

1985-03-01

Simple and sensitive spectrophotometric and radiochemical procedures are described for the assay of acetyl-CoA:arylamine N-acetyltransferase (NAT), which catalyzes the reaction acetyl-CoA + arylamine----N-acetylated arylamine + CoASH. The methods are applicable to crude tissue homogenates and blood lysates. The spectrophotometric assay is characterized by two features: (i) NAT activity is measured by quantifying the disappearance of the arylamine substrate as reflected by decreasing Schiff's base formation with dimethylaminobenzaldehyde. (ii) During the enzymatic reaction, the inhibitory product CoASH is recycled by the system acetyl phosphate/phosphotransacetylase to the substrate acetyl-CoA. The radiochemical procedure depends on enzymatic synthesis of (/sup 3/H)acetyl-CoA in the assaymore » using (/sup 3/H)acetate, ATP, CoASH, and acetyl-CoA synthetase. NAT activity is measured by quantifying N-(/sup 3/H)acetylarylamine after separation from (/sup 3/H)acetate by extraction. Product inhibition by CoASH is prevented in this system by the use of acetyl-CoA synthetase.« less

CBP-mediated SMN acetylation modulates Cajal body biogenesis and the cytoplasmic targeting of SMN.

PubMed

Lafarga, Vanesa; Tapia, Olga; Sharma, Sahil; Bengoechea, Rocio; Stoecklin, Georg; Lafarga, Miguel; Berciano, Maria T

2018-02-01

The survival of motor neuron (SMN) protein plays an essential role in the biogenesis of spliceosomal snRNPs and the molecular assembly of Cajal bodies (CBs). Deletion of or mutations in the SMN1 gene cause spinal muscular atrophy (SMA) with degeneration and loss of motor neurons. Reduced SMN levels in SMA lead to deficient snRNP biogenesis with consequent splicing pathology. Here, we demonstrate that SMN is a novel and specific target of the acetyltransferase CBP (CREB-binding protein). Furthermore, we identify lysine (K) 119 as the main acetylation site in SMN. Importantly, SMN acetylation enhances its cytoplasmic localization, causes depletion of CBs, and reduces the accumulation of snRNPs in nuclear speckles. In contrast, the acetylation-deficient SMNK119R mutant promotes formation of CBs and a novel category of promyelocytic leukemia (PML) bodies enriched in this protein. Acetylation increases the half-life of SMN protein, reduces its cytoplasmic diffusion rate and modifies its interactome. Hence, SMN acetylation leads to its dysfunction, which explains the ineffectiveness of HDAC (histone deacetylases) inhibitors in SMA therapy despite their potential to increase SMN levels.

Proteomic Analysis Reveals Differentially Regulated Protein Acetylation in Human Amyotrophic Lateral Sclerosis Spinal Cord

PubMed Central

Azadzoi, Kazem; Yang, Yun; Fei, Zhou; Dou, Kefeng; Kowall, Neil W.; Choi, Han-Pil; Vieira, Fernando; Yang, Jing-Hua

2013-01-01

Amyotrophic lateral sclerosis (ALS) is a progressive fatal neurodegenerative disease that primarily affects motor neurons in the brain and spinal cord. Histone deacetylase (HDAC) inhibitors have neuroprotective effects potentially useful for the treatment of neurodegenerative diseases including ALS; however, the molecular mechanisms underlying their potential efficacy is not well understood. Here we report that protein acetylation in urea-soluble proteins is differently regulated in post-mortem ALS spinal cord. Two-dimensional electrophoresis (2-DE) analysis reveals several protein clusters with similar molecular weight but different charge status. Liquid chromatography and tandem mass spectrometry (LC-MS/MS) identifies glial fibrillary acidic protein (GFAP) as the dominant component in the protein clusters. Further analysis indicates six heavily acetylated lysine residues at positions 89, 153, 189, 218, 259 and 331 of GFAP. Immunoprecipitation followed by Western blotting confirms that the larger form of GFAP fragments are acetylated and upregulated in ALS spinal cord. Further studies demonstrate that acetylation of the proteins additional to GFAP is differently regulated, suggesting that acetylation and/or deacetylation play an important role in pathogenesis of ALS. PMID:24312501

Regulation of Nur77 protein turnover through acetylation and deacetylation induced by p300 and HDAC1.

PubMed

Kang, Shin-Ae; Na, Hyelin; Kang, Hyun-Jin; Kim, Sung-Hye; Lee, Min-Ho; Lee, Mi-Ock

2010-09-15

Although the roles of Nur77, an orphan member of the nuclear hormone receptor superfamily, in the control of cellular proliferation, apoptosis, inflammation, and glucose metabolism, are well recognized, the molecular mechanism regulating the activity and expression of Nur77 is not fully understood. Acetylation of transcription factors has emerged recently as a major post-translational modification that regulates protein stability and transcriptional activity. Here, we examined whether Nur77 is acetylated, and we characterized potential associated factors. First, Nur77 was found to be an acetylated protein when examined by immunoprecipitation and western blotting using acetyl protein-specific antibodies. Second, expression of p300, which possesses histone acetyltransferase activity, enhanced the acetylation and protein stability of Nur77. Treatment with a histone deacetylase (HDAC) inhibitor, trichostatin A, also increased Nur77 acetylation. Among the several types of HDACs, HDAC1 was found as the major enzyme affecting protein level of Nur77. HDAC1 decreased the acetylation level, protein level, and transcriptional activity of Nur77. Interestingly, overexpression of Nur77 induced expression of both p300 and HDAC1. Finally, the expression of Nur77 increased along with that of p300, but decreased with induction of HDAC1 after treatment with epithelial growth factor, nerve growth factor, or 6-mercaptopurine, suggesting that the self-control of the acetylation status contributes to the transient induction of Nur77 protein. Taken together, these results demonstrate that acetylation of Nur77 is modulated by p300 and HDAC1, and suggest that acetylation is an important post-translational modification for the rapid turnover of Nur77 protein. Copyright 2010 Elsevier Inc. All rights reserved.

Acetylated adipate of retrograded starch as RS 3/4 type resistant starch.

PubMed

Kapelko-Żeberska, M; Zięba, T; Spychaj, R; Gryszkin, A

2015-12-01

This study was aimed at producing acetylated adipate of retrograded starch (ADA-R) with various degrees of substitution with functional groups and at determining the effect of esterification degree on resistance and pasting characteristics of the produced preparations. Paste was prepared from native potato starch, and afterwards frozen and defrosted. After drying and disintegration, the paste was acetylated and crosslinked using various doses of reagents. An increase in the total degree of esterification of the produced ADA-R-preparation caused an increase in its resistance to the action of amyloglucosidase. Viscosity of the paste produced from ADA-R-preparation in a wide range of acetylation degrees was increasing along with increasing crosslinking of starch. The study demonstrated that acetylated adipate of retrograded starch may be classified as a preparation of RS 3/4 type resistant starch (retrograded starch/chemically-modified starch) with good texture-forming properties. The conducted modification offers the possibility of modeling the level of resistance of the produced preparation. Copyright © 2015 Elsevier Ltd. All rights reserved.

[PHI regulates histone methylation and acetylation in Burkitt lymphoma Daudi cell line].

PubMed

Hong, Ling-Ling; Ma, Xu-Dong; Huang, Yi-Qun

2011-02-01

This study was purposed to investigate the effects of phenylhexyl isothiocyanate (PHI) on Burkitt lymphoma Daudi cell line and regulation of histone acetylation and methylation in Daudi cells, and to explore the potential mechanism. The apoptotic rate of Daudi cells treated with PHI was measured by flow cytometry, the changes of histone H3 and H4 acetylation, histone H3K9 and H3K4 methylation in Daudi cells treated with PHI were detected by Western blot. The results showed that PHI could induce apoptosis of Daudi cells, increased the acetylation level of H3 and H4, enhanced the methylation of H3K4, but reduced the methylation of H3K9. It is concluded that the PHI can up-regulate the acetylation level of histone H3 associated with transcription stimulation and the methylation of histone H3K4, down-regulate the methylation on histone H3K9 associated with transcription inhibition, promotes the apoptosis of Daudi cells. PHI may be a potential agent for target therapy of lymphoma.

Effect of electric field exposure on melatonin and enzyme circadian rhythms in the rat pineal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, B.; Anderson, L.E.; Hilton, D.I.

The effects of chronic 30-day electric field exposure on pineal serotonin N-acetyl transferase (EC 2.1.15) activity as well as melatonin and 5-methoxy tryptophol (5-MTOL) concentrations in rats, were assessed.

Acetylation of androgen receptor by ARD1 promotes dissociation from HSP90 complex and prostate tumorigenesis

PubMed Central

Zhang, Guanyi; Qian, Chiping; Zhang, Haitao; Zabaleta, Jovanny; Liu, Wanguo

2016-01-01

Prostate cancer is an androgen receptor (AR)-driven disease and post-translational modification of AR is critical for AR activation. We previously reported that Arrest-defective protein 1 (ARD1) is an oncoprotein in prostate cancer. It acetylates and activates AR to promote prostate tumorigenesis. However, the ARD1-targeted residue within AR and the mechanisms of the acetylation event in prostate tumorigenesis remained unknown. In this study, we show that ARD1 acetylates AR at lysine 618 (K618) in vitro and in vivo. An AR construct with the charged lysine substitution by arginine (AR-618R) reduces RNA Pol II binding, AR transcriptional activity, prostate cancer cell growth, and xenograft tumor formation due to attenuation of AR nuclear translocation, whereas, construct mimicking neutral polar substitution acetylation at K618 by glutamine (AR-618Q) enhanced these effects beyond that of the wild-type AR. Mechanistically, ARD1 forms a ternary complex with AR and HSP90 in vitro and in vivo. Expression of ARD1 increases levels of AR acetylation and AR-HSP90 dissociation in a dose dependent manner. Moreover, the AR acetylation defective K618R mutant is unable to dissociate from HSP90 while the HSP90-dissociated AR is acetylated following ligand exposure. This work identifies a new mechanism for ligand-induced AR-HSP90 dissociation and AR activation. Targeting ARD1-mediated AR acetylation may be a potent intervention for AR-dependent prostate cancer therapy. PMID:27659526

21 CFR 172.828 - Acetylated monoglycerides.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acetylated monoglycerides. 172.828 Section 172.828 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.828...

Monoclonal antibodies against pools of mono- and polyacetylated peptides selectively recognize acetylated lysines within the context of the original antigen.

PubMed

Sandomenico, Annamaria; Focà, Annalia; Sanguigno, Luca; Caporale, Andrea; Focà, Giuseppina; Pignalosa, Angelica; Corvino, Giusy; Caragnano, Angela; Beltrami, Antonio Paolo; Antoniali, Giulia; Tell, Gianluca; Leonardi, Antonio; Ruvo, Menotti

Post-translational modifications (PTMs) strongly influence the structure and function of proteins. Lysine side chain acetylation is one of the most widespread PTMs, and it plays a major role in several physiological and pathological mechanisms. Protein acetylation may be detected by mass spectrometry (MS), but the use of monoclonal antibodies (mAbs) is a useful and cheaper option. Here, we explored the feasibility of generating mAbs against single or multiple acetylations within the context of a specific sequence. As a model, we used the unstructured N-terminal domain of APE1, which is acetylated on Lys27, Lys31, Lys32 and Lys35. As immunogen, we used a peptide mixture containing all combinations of single or multi-acetylated variants encompassing the 24-39 protein region. Targeted screening of the resulting clones yielded mAbs that bind with high affinity to only the acetylated APE1 peptides and the acetylated protein. No binding was seen with the non-acetylated variant or unrelated acetylated peptides and proteins, suggesting a high specificity for the APE1 acetylated molecules. MAbs could not finely discriminate between the differently acetylated variants; however, they specifically bound the acetylated protein in mammalian cell extracts and in intact cells and tissue slices from both breast cancers and from a patient affected by idiopathic dilated cardiomyopathy. The data suggest that our approach is a rapid and cost-effective method to generate mAbs against specific proteins modified by multiple acetylations or other PTMs.

Making and Missing Connections: Exploring Twitter Chats as a Learning Tool in a Preservice Teacher Education Course

ERIC Educational Resources Information Center

Hsieh, Betina

2017-01-01

Research on social media use in education indicates that network-based connections can enable powerful teacher learning opportunities. Using a connectivist theoretical framework (Siemens, 2005), this study focuses on secondary teacher candidates (TCs) who completed, archived, and reflected upon 1-hour Twitter chats (N = 39) to explore the promise…

Transmutation of human glutathione transferase A2-2 with peroxidase activity into an efficient steroid isomerase.

PubMed

Pettersson, Par L; Johansson, Ann-Sofie; Mannervik, Bengt

2002-08-16

A major goal in protein engineering is the tailor-making of enzymes for specified chemical reactions. Successful attempts have frequently been based on directed molecular evolution involving libraries of random mutants in which variants with desired properties were identified. For the engineering of enzymes with novel functions, it would be of great value if the necessary changes of the active site could be predicted and implemented. Such attempts based on the comparison of similar structures with different substrate selectivities have previously met with limited success. However, the present work shows that the knowledge-based redesign restricted to substrate-binding residues in human glutathione transferase A2-2 can introduce high steroid double-bond isomerase activity into the enzyme originally characterized by glutathione peroxidase activity. Both the catalytic center activity (k(cat)) and catalytic efficiency (k(cat)/K(m)) match the values of the naturally evolved glutathione transferase A3-3, the most active steroid isomerase known in human tissues. The substrate selectivity of the mutated glutathione transferase was changed 7000-fold by five point mutations. This example demonstrates the functional plasticity of the glutathione transferase scaffold as well as the potential of rational active-site directed mutagenesis as a complement to DNA shuffling and other stochastic methods for the redesign of proteins with novel functions.

Purification and characterization of the acetyl-CoA synthetase from Mycobacterium tuberculosis.

PubMed

Li, Ru; Gu, Jing; Chen, Peng; Zhang, Zhiping; Deng, Jiaoyu; Zhang, Xianen

2011-11-01

Acetyl-CoA (AcCoA) synthetase (Acs) catalyzes the conversion of acetate into AcCoA, which is involved in many catabolic and anabolic pathways. Although this enzyme has been studied for many years in many organisms, the properties of Mycobacterium tuberculosis Acs and the regulation of its activity remain unknown. Here, the putative acs gene of M. tuberculosis H37Rv (Mt-Acs) was expressed as a fusion protein with 6×His-tag on the C-terminus in Escherichia coli. The recombinant Mt-Acs protein was successfully purified and then its enzymatic characteristics were analyzed. The optimal pH and temperature, and the kinetic parameters of Mt-Acs were determined. To investigate whether Mt-Acs is regulated by lysine acetylation as reported for Salmonella enterica Acs, its mutant K617R was also generated. Determination of the enzymatic activity suggests that Lys-617 is critical for its function. We further demonstrated that Mt-Acs underwent auto-acetylation with acetate but not with AcCoA as the acetyl donor, which resulted in the decrease of its activity. CoA, the substrate for AcCoA formation, inhibited the auto-acetylation. Furthermore, the silent information regulator (Sir2) of M. tuberculosis (Mt-Sir2) could catalyze Mt-Acs deacetylation, which resulted in activation of Acs. These results may provide more insights into the physiological roles of Mt-Acs in M. tuberculosis central metabolism.

Wind conditions on migration influence the annual survival of a neotropical migrant, the western yellow-breasted chat (Icteria virens auricollis).

PubMed

Huang, Andrew C; Bishop, Christine A; McKibbin, René; Drake, Anna; Green, David J

2017-08-10

Long-distance migratory birds in North America have undergone precipitous declines over the past half-century. Although the trend is clear, for many migrating species underpinning the exact causes poses a challenge to conservation due to the numerous stressors that they encounter. Climate conditions during all phases of their annual cycle can have important consequences for their survival. Here, using 15 years of capture-recapture dataset, we determined the effects of various climate factors during the breeding, wintering, and migrating stages on the annual survival of a western yellow-breasted chat (Icteria virens auricollis) population breeding in southwestern Canada. El Niño effects over the entire annual cycle had little influence on the annual apparent survival of yellow-breasted chats. However, we found evidence that wind conditions during migration, specifically average westerly wind speed or the frequency of storm events, had significant adverse effects on adult annual apparent survival. In comparison, precipitation levels on wintering ground had little to no influence on adult annual apparent survival, whereas growing degree days on the breeding ground had moderate but positive effects. In the face of climate change and its predicted impacts on climate processes, understanding the influence of weather conditions on the survival of migrating birds can allow appropriate conservation strategies to be adopted for chats and other declining neotropical migrants.

21 CFR 172.828 - Acetylated monoglycerides.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Reichert-Meissl value of 75-200 and an acid value of less than 6. (c) The food additive is used at a level... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acetylated monoglycerides. 172.828 Section 172.828 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...

N-Acetyl-L-Leucine Accelerates Vestibular Compensation after Unilateral Labyrinthectomy by Action in the Cerebellum and Thalamus

PubMed Central

Xiong, Guoming; Potschka, Heidrun; Jahn, Klaus; Bartenstein, Peter; Brandt, Thomas; Dutia, Mayank; Dieterich, Marianne; Strupp, Michael; la Fougère, Christian; Zwergal, Andreas

2015-01-01

An acute unilateral vestibular lesion leads to a vestibular tone imbalance with nystagmus, head roll tilt and postural imbalance. These deficits gradually decrease over days to weeks due to central vestibular compensation (VC). This study investigated the effects of i.v. N-acetyl-DL-leucine, N-acetyl-L-leucine and N-acetyl-D-leucine on VC using behavioural testing and serial [18F]-Fluoro-desoxyglucose ([18F]-FDG)-μPET in a rat model of unilateral chemical labyrinthectomy (UL). Vestibular behavioural testing included measurements of nystagmus, head roll tilt and postural imbalance as well as sequential whole-brain [18F]-FDG-μPET was done before and on days 1,3,7 and 15 after UL. A significant reduction of postural imbalance scores was identified on day 7 in the N-acetyl-DL-leucine (p < 0.03) and the N-acetyl-L-leucine groups (p < 0.01), compared to the sham treatment group, but not in the N-acetyl-D-leucine group (comparison for applied dose of 24 mg i.v. per rat, equivalent to 60 mg/kg body weight, in each group). The course of postural compensation in the DL- and L-group was accelerated by about 6 days relative to controls. The effect of N-acetyl-L-leucine on postural compensation depended on the dose: in contrast to 60 mg/kg, doses of 15 mg/kg and 3.75 mg/kg had no significant effect. N-acetyl-L-leucine did not change the compensation of nystagmus or head roll tilt at any dose. Measurements of the regional cerebral glucose metabolism (rCGM) by means of μPET revealed that only N-acetyl-L-leucine but not N-acetyl-D-leucine caused a significant increase of rCGM in the vestibulocerebellum and a decrease in the posterolateral thalamus and subthalamic region on days 3 and 7. A similar pattern was found when comparing the effect of N-acetyl-L-leucine on rCGM in an UL-group and a sham UL-group without vestibular damage. In conclusion, N-acetyl-L-leucine improves compensation of postural symptoms after UL in a dose-dependent and specific manner, most likely by

N-acetyl-L-leucine accelerates vestibular compensation after unilateral labyrinthectomy by action in the cerebellum and thalamus.

PubMed

Günther, Lisa; Beck, Roswitha; Xiong, Guoming; Potschka, Heidrun; Jahn, Klaus; Bartenstein, Peter; Brandt, Thomas; Dutia, Mayank; Dieterich, Marianne; Strupp, Michael; la Fougère, Christian; Zwergal, Andreas

2015-01-01

An acute unilateral vestibular lesion leads to a vestibular tone imbalance with nystagmus, head roll tilt and postural imbalance. These deficits gradually decrease over days to weeks due to central vestibular compensation (VC). This study investigated the effects of i.v. N-acetyl-DL-leucine, N-acetyl-L-leucine and N-acetyl-D-leucine on VC using behavioural testing and serial [18F]-Fluoro-desoxyglucose ([18F]-FDG)-μPET in a rat model of unilateral chemical labyrinthectomy (UL). Vestibular behavioural testing included measurements of nystagmus, head roll tilt and postural imbalance as well as sequential whole-brain [18F]-FDG-μPET was done before and on days 1,3,7 and 15 after UL. A significant reduction of postural imbalance scores was identified on day 7 in the N-acetyl-DL-leucine (p < 0.03) and the N-acetyl-L-leucine groups (p < 0.01), compared to the sham treatment group, but not in the N-acetyl-D-leucine group (comparison for applied dose of 24 mg i.v. per rat, equivalent to 60 mg/kg body weight, in each group). The course of postural compensation in the DL- and L-group was accelerated by about 6 days relative to controls. The effect of N-acetyl-L-leucine on postural compensation depended on the dose: in contrast to 60 mg/kg, doses of 15 mg/kg and 3.75 mg/kg had no significant effect. N-acetyl-L-leucine did not change the compensation of nystagmus or head roll tilt at any dose. Measurements of the regional cerebral glucose metabolism (rCGM) by means of μPET revealed that only N-acetyl-L-leucine but not N-acetyl-D-leucine caused a significant increase of rCGM in the vestibulocerebellum and a decrease in the posterolateral thalamus and subthalamic region on days 3 and 7. A similar pattern was found when comparing the effect of N-acetyl-L-leucine on rCGM in an UL-group and a sham UL-group without vestibular damage. In conclusion, N-acetyl-L-leucine improves compensation of postural symptoms after UL in a dose-dependent and specific manner, most likely by

Downregulation of acetyl-CoA synthetase 2 is a metabolic hallmark of tumor progression and aggressiveness in colorectal carcinoma.

PubMed

Bae, Jeong Mo; Kim, Jung Ho; Oh, Hyeon Jeong; Park, Hye Eun; Lee, Tae Hun; Cho, Nam-Yun; Kang, Gyeong Hoon

2017-02-01

Acetyl-CoA synthetase-2 is an emerging key enzyme for cancer metabolism, which supplies acetyl-CoA for tumor cells by capturing acetate as a carbon source under stressed conditions. However, implications of acetyl-CoA synthetase-2 in colorectal carcinoma may differ from other malignancies, because normal colonocytes use short-chain fatty acids as an energy source, which are supplied by fermentation of the intestinal flora. Here we analyzed acetyl-CoA synthetase-2 mRNA expression by reverse-transcription quantitative PCR in paired normal mucosa and tumor tissues of 12 colorectal carcinomas, and subsequently evaluated acetyl-CoA synthetase-2 protein expression by immunohistochemistry in 157 premalignant colorectal lesions, including 60 conventional adenomas and 97 serrated polyps, 1,106 surgically resected primary colorectal carcinomas, and 23 metastatic colorectal carcinomas in the liver. In reverse-transcription quantitative PCR analysis, acetyl-CoA synthetase-2 mRNA expression was significantly decreased in tumor tissues compared with corresponding normal mucosa tissues. In acetyl-CoA synthetase-2 immunohistochemistry analysis, all 157 colorectal polyps showed moderate-to-strong expression of acetyl-CoA synthetase-2. However, cytoplasmic acetyl-CoA synthetase-2 expression was downregulated (acetyl-CoA synthetase-2 low expression) in 771 (69.7%) of 1,106 colorectal carcinomas and 21 (91.3%) of 23 metastatic lesions. The colorectal carcinomas with acetyl-CoA synthetase-2-low expression were significantly associated with advanced TNM stage, poor differentiation, and frequent tumor budding. Regarding the molecular aspect, acetyl-CoA synthetase-2-low expression exhibited a tendency of frequent KRT7 expression and decreased KRT20 and CDX2 expression. In survival analysis, acetyl-CoA synthetase-2-low expression was an independent prognostic factor for poor 5-year progression-free survival (hazard ratio, 1.39; 95% confidence interval, 1.08-1.79; P=0.01). In conclusion

Non-stoichiometric O-acetylation of Shigella flexneri 2a O-specific polysaccharide: synthesis and antigenicity.

PubMed

Gauthier, Charles; Chassagne, Pierre; Theillet, François-Xavier; Guerreiro, Catherine; Thouron, Françoise; Nato, Farida; Delepierre, Muriel; Sansonetti, Philippe J; Phalipon, Armelle; Mulard, Laurence A

2014-06-28

Synthetic functional mimics of the O-antigen from Shigella flexneri 2a are seen as promising vaccine components against endemic shigellosis. Herein, the influence of the polysaccharide non-stoichiometric di-O-acetylation on antigenicity is addressed for the first time. Three decasaccharides, representing relevant internal mono- and di-O-acetylation profiles of the O-antigen, were synthesized from a pivotal protected decasaccharide designed to tailor late stage site-selective O-acetylation. The latter was obtained via a convergent route involving the imidate glycosylation chemistry. Binding studies to five protective mIgGs showed that none of the acetates adds significantly to broad antibody recognition. Yet, one of the five antibodies had a unique pattern of binding. With IC50 in the micromolar to submicromolar range mIgG F22-4 exemplifies a remarkable tight binding antibody against diversely O-acetylated and non-O-acetylated fragments of a neutral polysaccharide of medical importance.

Asymmetric distribution of glucose and indole-3-acetyl-myo-inositol in geostimulated Zea mays seedlings

NASA Technical Reports Server (NTRS)

Momonoki, Y. S.; Bandurski, R. S. (Principal Investigator)

1988-01-01

Indole-3-acetyl-myo-inositol occurs in both the kernel and vegetative shoot of germinating Zea mays seedlings. The effect of a gravitational stimulus on the transport of [3H]-5-indole-3-acetyl-myo-inositol and [U-14C]-D-glucose from the kernel to the seedling shoot was studied. Both labeled glucose and labeled indole-3-acetyl-myo-inositol become asymmetrically distributed in the mesocotyl cortex of the shoot with more radioactivity occurring in the bottom half of a horizontally placed seedling. Asymmetric distribution of [3H]indole-3-acetic acid, derived from the applied [3H]indole-3-acetyl-myo-inositol, occurred more rapidly than distribution of total 3H-radioactivity. These findings demonstrate that the gravitational stimulus can induce an asymmetric distribution of substances being transported from kernel to shoot. They also indicate that, in addition to the transport asymmetry, gravity affects the steady state amount of indole-3-acetic acid derived from indole-3-acetyl-myo-inositol.

Purification and Biochemical Characterization of Glutathione S-Transferase from Down Syndrome and Normal Children Erythrocytes: A Comparative Study

ERIC Educational Resources Information Center

Hamed, Ragaa R.; Maharem, Tahany M.; Abdel-Meguid, Nagwa; Sabry, Gilane M.; Abdalla, Abdel-Monem; Guneidy, Rasha A.

2011-01-01

Down syndrome (DS) is the phenotypic manifestation of trisomy 21. Our study was concerned with the characterization and purification of glutathione S-transferase enzyme (GST) from normal and Down syndrome (DS) erythrocytes to illustrate the difference in the role of this enzyme in the cell. Glutathione S-transferase and glutathione (GSH) was…

Conformational Aspects of the O-acetylation of C-tetra(phenyl)calixpyrogallol[4]arene.

PubMed

Casas-Hinestroza, José Luis; Maldonado, Mauricio

2018-05-20

Reaction between pyrogallol and benzaldehyde results in a conformational mixture of C- tetra(phenyl)pyrogallol[4]arene (crown and chair). The conformer mixture was separated using crystallization procedures and the structures were determined using FTIR, ¹H-NMR, and 13 C-NMR. O -acetylation of C- tetra(phenyl)pyrogallol[4]arene (chair) with acetic anhydride, in pyridine results in the formation of dodecaacetyl-tetra(phenyl)pyrogallol[4]arene. The structure was determined using ¹H-NMR and 13 C-NMR finding that the product maintains the conformation of the starting conformer. On the other hand, the O -acetylation reaction of C- tetra(phenyl)pirogallol[4]arene (crown) under same conditions proceeded efficiently, and its structure was determined using ¹H-NMR and 13 C-NMR. Dynamic ¹H-NMR of acetylated pyrogallolarene was studied by means of variable temperature in DMSO- d ₆ solution, and it revealed that two conformers are formed in the solution. Boat conformations for acetylated pyrogallolarene showed a slow interconversion at room temperature.

Acetylation of pregnane X receptor protein determines selective function independent of ligand activation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biswas, Arunima; Pasquel, Danielle; Tyagi, Rakesh Kumar

2011-03-18

Research highlights: {yields} Pregnane X receptor (PXR), a major regulatory protein, is modified by acetylation. {yields} PXR undergoes dynamic deacetylation upon ligand-mediated activation. {yields} SIRT1 partially mediates PXR deacetylation. {yields} PXR deacetylation per se induces lipogenesis mimicking ligand-mediated activation. -- Abstract: Pregnane X receptor (PXR), like other members of its class of nuclear receptors, undergoes post-translational modification [PTM] (e.g., phosphorylation). However, it is unknown if acetylation (a major and common form of protein PTM) is observed on PXR and, if it is, whether it is of functional consequence. PXR has recently emerged as an important regulatory protein with multiple ligand-dependentmore » functions. In the present work we show that PXR is indeed acetylated in vivo. SIRT1 (Sirtuin 1), a NAD-dependent class III histone deacetylase and a member of the sirtuin family of proteins, partially mediates deacetylation of PXR. Most importantly, the acetylation status of PXR regulates its selective function independent of ligand activation.« less

Identification of zinc finger transcription factor EGR2 as a novel acetylated protein.

PubMed

Noritsugu, Kota; Ito, Akihiro; Nakao, Yoichi; Yoshida, Minoru

2017-08-05

EGR2 is a zinc finger transcription factor that regulates myelination in the peripheral nervous system and T cell anergy. The transcriptional activity of EGR2 is known to be regulated by its co-activators and/or co-repressors. Although the activity of transcription factors is generally regulated not only by interactions with co-regulators but also posttranslational modifications including acetylation, little is known about posttranslational modifications of EGR2. Here we show that EGR2 is a novel acetylated protein. Through immunoblotting analyses using an antibody that specifically recognizes the acetylated form of EGR2, CBP and p300 were identified as acetyltransferases, while HDAC6, 10 and SIRT1 were identified as deacetylases of EGR2. Although the NuRD complex containing HDAC1 and HDAC2 is known to associate with EGR2, the present study suggests that acetylation of EGR2 is regulated independently of NuRD. Copyright © 2017 Elsevier Inc. All rights reserved.

A Study on the Mobile Learning of English and American Literature Based on WeChat Public Account