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1.
EMBO J ; 40(24): e108307, 2021 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-34786730

RESUMO

Histone chaperones modulate the stability of histones beginning from histone synthesis, through incorporation into DNA, and during recycling during transcription and replication. Following histone removal from DNA, chaperones regulate histone storage and degradation. Here, we demonstrate that UBR7 is a histone H3.1 chaperone that modulates the supply of pre-existing post-nucleosomal histone complexes. We demonstrate that UBR7 binds to post-nucleosomal H3K4me3 and H3K9me3 histones via its UBR box and PHD. UBR7 binds to the non-nucleosomal histone chaperone NASP. In the absence of UBR7, the pool of NASP-bound post-nucleosomal histones accumulate and chromatin is depleted of H3K4me3-modified histones. We propose that the interaction of UBR7 with NASP and histones opposes the histone storage functions of NASP and that UBR7 promotes reincorporation of post-nucleosomal H3 complexes.


Assuntos
Autoantígenos/metabolismo , Histonas/metabolismo , Proteínas Nucleares/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Linhagem Celular , Células HEK293 , Células HeLa , Código das Histonas , Histonas/química , Humanos , Nucleossomos/metabolismo , Domínios Proteicos
2.
Nat Methods ; 18(3): 303-308, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33589837

RESUMO

Current proteomic approaches disassemble and digest nucleosome particles, blurring readouts of the 'histone code'. To preserve nucleosome-level information, we developed Nuc-MS, which displays the landscape of histone variants and their post-translational modifications (PTMs) in a single mass spectrum. Combined with immunoprecipitation, Nuc-MS quantified nucleosome co-occupancy of histone H3.3 with variant H2A.Z (sixfold over bulk) and the co-occurrence of oncogenic H3.3K27M with euchromatic marks (for example, a >15-fold enrichment of dimethylated H3K79me2). Nuc-MS is highly concordant with chromatin immunoprecipitation-sequencing (ChIP-seq) and offers a new readout of nucleosome-level biology.


Assuntos
Histonas/metabolismo , Nucleossomos/metabolismo , Proteômica/métodos , Espectrometria de Massas por Ionização por Electrospray/métodos , Linhagem Celular , Imunoprecipitação da Cromatina/métodos , Células HEK293 , Código das Histonas , Humanos , Metilação
3.
Popul Med ; 22020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33521651

RESUMO

INTRODUCTION: Despite decreases in the overall US smoking rate, tobacco use remains more common in some areas and by some groups. Deeper understanding of group differences is needed in order to tailor public health campaigns to the interests, perceptions and experiences of targeted audiences. Although some differences have been identified across African American and Caucasian smokers in the United States, additional insight is needed regarding factors that differentiate these groups. This study examined tobacco-related perceptions and practices, with an emphasis on identifying differences across African American and Caucasian smokers. Toward this goal, we examined key demographic variables of race and age, and tobacco use characteristics. METHODS: The sample consisted of 284 people from the Jackson, Mississippi area who participated in focus groups and completed surveys addressing a variety of tobacco-related topics, including knowledge and perceptions of products as well as use and health information seeking behavior. The selection criteria and recruitment approach ensured a balance across race (black, white), age (18-34, >35 years), sex, and cigarette smoking status (current, former, never). Statistical analyses were performed using SAS (v.9.4). RESULTS: Differences were observed across demographic subgroups regarding type and pattern of tobacco products used (e.g. mentholated, markers of nicotine dependence, hookah). Differences in preferred sources of health information based on age as well as perceptions of risk as a function of age, smoking status and race were also noted. Exposure to secondhand smoke and perceptions of its risks, quitting efforts and cessation methods differed by race. CONCLUSIONS: Study findings suggest key differences across important subgroups. Knowledge of such differences has the potential to improve strategic public health messaging, allowing health campaigns to more effectively prevent tobacco product uptake as well as promote interest in quitting tobacco.

4.
Int J Healthc Med Sci ; 4(6): 111-116, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30450441

RESUMO

BACKGROUND: E-cigarette use has grown in popularity, especially as the devices have been touted as smoking cessation tools. In an exploratory study, we sought to compare dual users (i.e., users of both combustible tobacco and e-cigarettes) to e-cigarette only users. METHODS: The Electronic Cigarette Opinion Survey (ECOS) was employed to assess users' (n=78) perceptions and consumption of e-cigarettes and combustible cigarettes. Quantity of e-juice and nicotine used and time of initial nicotine exposure were assessed. Multivariable logistic regression was used to evaluate the association between e-cigarette use behaviors and being an e-cigarette only user compared to a dual user. RESULTS: Compared to dual users, e-cigarette only users consumed higher levels of nicotine in e-juice (p=0.0009) and more nicotine per month (p=0.03). For dual users, the time of first nicotine exposure after waking was significantly earlier than for e-cigarette only users (mean= 9.6 minutes (SD= 8.0) and mean= 26.6 minutes (SD= 22.0), respectively; p=0.0056). Results from the regression models suggest the amount of e-juice consumed and time of first nicotine exposure after waking are significantly associated with being an e-cigarette only user. CONCLUSIONS: These findings shed light on the perceptions and use patterns of e-cigarette only users compared to dual users. As regulation of e-cigarettes is considered, understanding the impact of e-cigarettes and dual use is imperative. Despite frequent marketing claims that e-cigarettes are completely safe, health campaigns need to convey emerging and mixed findings on safety as well as current scientific uncertainty to the public.

5.
Tob Induc Dis ; 16: 48, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-31516445

RESUMO

INTRODUCTION: As e-cigarette use increases, questions about individual and public health effects remain unanswered (e.g. cessation tool, addiction path). Despite increasing use, few studies have focused on vape shop patrons. This study examined whether vape shop patrons believe their health is affected by the use of e-cigs; more specifically, the aim was to evaluate the association between e-cig use, change in tobacco use, and perception of health. METHODS: A survey of e-cig users (N=78) was conducted in vape shops. Questions included e-cig and traditional tobacco use, health perceptions, and demographics. Descriptive techniques were used to characterize participants as either those who perceived e-cig use improved their health or those who perceived their health unaffected. Logistic regression assessed the association between change in tobacco use, e-cig use, and perception of health effects. RESULTS: Most reported daily e-cig (91%) and current (11.5%) or former (78.2%) combustible cigarette use. Approximately, three-fourths (76.9%) perceived better health; the remainder (23.1%) perceived unaffected health. Change in cigarette use was significantly associated with perceptions that health is better with e-cig use. Participants who decreased cigarette use by 2-3 cartons/month and more than 3 cartons/month were significantly more likely to indicate that e-cig use has improved their health compared to those who decreased tobacco use by 1.5 cartons or fewer per month (OR=4.35, 95% CI: 1.13-16.9; OR=25.67, 95% CI: 2.97-221.7, respectively). CONCLUSIONS: The majority of e-cig users perceived better health. Our findings suggest that health campaign designers should carefully assess the scientific uncertainty surrounding the use of these devices and consider means to clearly convey this information. Given the lack of scientific agreement on the health effects of e-cigs and the important role that perceptions play in behavior, health campaign designers, health education practitioners, policy makers, and health care providers should err on the side of caution when advising individuals about e-cig use.

6.
Minerva Gastroenterol Dietol ; 64(2): 126-137, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29243894

RESUMO

The manufacture and consumption of alcohol are ubiquitous and as old as time. Alcohol use disorder (AUD) is defined as a problematic pattern of alcohol use leading to clinically significant impairment. The physical injuries that result from excessive alcohol consumption are varied including end-organ damage to liver (alcohol-associated liver disease [ALD]), pancreas, brain and heart, and systemic consequences including several forms of cancer. Liver transplantation (LT) remains the treatment of last resort for life-threatening liver disease. LT provides a valuable magnifying glass under which to examine the complex interactions between social drinking, AUD, and ALD. ALD is the second most frequent indication for LT in the US (data of 2015). We review the current data on evaluation of patients with AUD and ALD for liver transplantation; on the significance of abstinence from alcohol in patient selection and pre- and post-LT management. We discuss monitoring for relapse prior to and after LT. Finally, we look at outcomes, first from the perspective of impact on the allograft and then the perspective of maintaining the health of the LT patient with AUD, which includes management of addiction.


Assuntos
Hepatopatias Alcoólicas/cirurgia , Transplante de Fígado , Humanos , Hepatopatias Alcoólicas/complicações , Hepatopatias Alcoólicas/diagnóstico , Hepatopatias Alcoólicas/mortalidade , Taxa de Sobrevida , Resultado do Tratamento
7.
Tob Prev Cessat ; 42018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29423455

RESUMO

INTRODUCTION: In Appalachia, youth tobacco-use rates remain higher than the U.S. national average. Past research has indicated that several factors are related to high rates of tobacco use among Appalachian youth (e.g. low socioeconomic status, rural lifestyles). Of the Appalachian states, Kentucky has one of the highest rates of youth tobacco use. The aim of this study was to explore views of tobacco among Kentucky youth living in Appalachian counties. METHODS: In Fall 2014 - Spring 2015, focus group interviews were conducted with middle and high school students (N=109) in Appalachian counties in Kentucky. Each focus group session included open-ended questions and was conducted by trained facilitators. Focus group transcriptions and field notes were analyzed for themes. RESULTS: Study participants described an entrenched culture of tobacco. Three themes exemplified this culture. First, adult behavior served to enable youth tobacco use (e.g. teachers ignoring dip use in class, adults smoking with youth). Second, tobacco is easily accessible to youth (e.g. restrictions on youth sales are often ignored, family members provide). Third, symbols of tobacco are prevalent (e.g. festivals celebrating tobacco heritage, tobacco barns, and tobacco marketing logos). CONCLUSIONS: Youth participants described a deeply rooted tobacco culture, which they believed was unlikely to change. Additional studies and health education efforts are needed in these rural communities. Further, stricter enforcement of tobacco sales and marketing restrictions may be helpful in protecting this vulnerable population.

8.
Tob Prev Cessat ; 32017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28815224

RESUMO

INTRODUCTION: This study examined electronic cigarette (e-cig) content in visual materials posted on the social-media platforms Instagram and Pinterest. Both platforms allow users to upload pictures to the internet and share them globally. Users can search for pictures tagged with specific keywords and phrases. METHODS: Using content analysis, this study identified themes in image postings of e-cigs on social media. During five weeks of data collection, keywords were used to identify pictures related to e-cigs. These pictures were then coded into one or more categories. RESULTS: The three most popular categories for Instagram posts were marketing, customization and juices/flavors. The three most popular categories for Pinterest posts were customization, marketing and memes. CONCLUSIONS: Because of the persuasive power of visuals, it is important to examine communication on Instagram and Pinterest as well as the specific visual messages communicated. Stores and manufacturers use these and similar platforms to communicate with users and potential users; thus it seems that marketers are capitalizing on opportunities for persuasive appeal. The results highlight the popularity of e-cig content on these two social media platforms and reveal an emphasis on marketing and customization.

9.
Tob Prev Cessat ; 32017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28725876

RESUMO

INTRODUCTION: Videos promoting electronic cigarettes (e-cigarettes) can be easily accessed on YouTube. Marketing claims present in YouTube videos may help shape the public's opinion of e-cigarettes. Thus, it is important to understand the most frequent marketing claims and video sources. METHODS: The objectives of this study were to 1) identify marketing claims in YouTube videos that are commonly made on e-cigarette retail websites and 2) compare the frequency of marketing claims in user-generated and professional YouTube videos. Through content analysis, this study evaluated six marketing claims and descriptive information about YouTube videos (n = 50) related to "electronic cigarettes" and "vape". RESULTS: Overall, the most frequent marketing claim promoted e-cigarette use as better than traditional tobacco use (52%). Approximately 65% of videos appeared to be user-generated and 35% were professionally-produced. Compared to user-generated videos, significantly more professional videos made claims that e-cigarettes are cleaner (p < 0.001) and cheaper (p = 0.04) than traditional cigarettes. Additionally, more professional videos had claims promoting e-cigarettes as better than traditional cigarettes because of their convenience-the user can smoke anywhere (p < 0.0001) and the products do not produce secondhand smoke (p < 0.001). The most frequent claim in user-generated videos was related to recreation (53%). CONCLUSIONS: Videos on YouTube promote e-cigarettes as safer than other tobacco products. Videos appearing to be user-generated contained different marketing claims compared to professional videos. Further research is necessary to assess how the perceived source of the video impacts the ways these marketing claims shape public perception and influence use.

10.
IEEE Trans Nanobioscience ; 5(3): 149-56, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16999239

RESUMO

Aureococcus anophagefferens, a harmful bloom-forming alga responsible for brown tides in estuaries of the Middle Atlantic U.S., has been investigated by atomic force microscopy for the first time, using probes functionalized with a monoclonal antibody specific for the alga. The rupture force between a single monoclonal antibody and the surface of A. anophagefferens was experimentally found to be 246 +/- 11 pN at the load rate of 12 nN/s. Force histograms for A. anophagefferens and other similarly-sized algae are presented and analyzed. The results illustrate the effects of load rates, and demonstrate that force-distance measurements can be used to build biosensors with high signal-to-noise ratios for A. anophagefferens. The methods described in this paper can be used, in principle, to construct sensors with single-cell resolution for arbitrary cells for which monoclonal antibodies are available.


Assuntos
Complexo Antígeno-Anticorpo/análise , Bioensaio/métodos , Técnicas Biossensoriais/métodos , Eutrofização , Imunoensaio/métodos , Microscopia de Força Atômica/métodos , Phaeophyceae/isolamento & purificação , Complexo Antígeno-Anticorpo/imunologia , Técnicas Biossensoriais/instrumentação , Monitoramento Ambiental/instrumentação , Monitoramento Ambiental/métodos , Imunoensaio/instrumentação , Phaeophyceae/classificação , Phaeophyceae/imunologia , Projetos Piloto , Estresse Mecânico , Transdutores
11.
Tob Prev Cessat ; 2(Suppl)2016.
Artigo em Inglês | MEDLINE | ID: mdl-28725875

RESUMO

INTRODUCTION: E-cigarettes have increased in popularity and given rise to a new type of sales outlet-the vape shop. Expanding on work examining vape shop employee e-cigarette and tobacco attitudes and behaviors1, this study examined key messages that vape shop employees communicate to customers. METHODS: Using informal interviews, observations, and a cross-sectional survey, we examined vape shop employees' (n=16) perceptions and e-cigarette use. Data were collected in nine vape shops in Louisville, Kentucky. We used open coding to analyze the qualitative interviews, observation notes, and open-ended survey responses. Descriptive statistics were used to analyze survey data. RESULTS: The findings revealed that nearly all employees were former smokers (93.8%), who now only use e-cigarettes. Over one-third of the employees (37.5%) began using e-cigarettes as a replacement for traditional cigarettes, and 93.8% reported better health (e.g., easier breathing, less coughing) since starting to use e-cigarettes. Although most employees believed e-cigarettes should be regulated, 56.3% thought regulations should be different from those governing traditional cigarettes. Analysis of qualitative data revealed that employees see themselves as health advocates who: 1) provide instructions on vaping and promote a vape community, 2) encourage cessation of traditional cigarettes, and 3) support some regulations. CONCLUSIONS: The findings reveal that vape shop employees regard e-cigarettes as viable smoking cessation tools and relish their role in assisting others in taking what employees view as positive health actions. Future research addressing communication between vape shop employees and customers, especially related to smoking cessation and health, is needed.

15.
Nanotechnology ; 19(16): 165501, 2008 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-21825643

RESUMO

Nanoscale actuators are essential components of the NEMS (nanoelectromechanical systems) and nanorobots of the future, and are expected to become a major area of development within nanotechnology. This paper demonstrates for the first time that individual polypyrrole (PPy) nanowires with diameters under 100 nm exhibit actuation behavior, and therefore can potentially be used for constructing nanoscale actuators. PPy is an electroactive polymer which can change volume on the basis of its oxidation state. PPy-based macroscale and microscale actuators have been demonstrated, but their nanoscale counterparts have not been realized until now. The research reported here answers positively the fundamental question of whether PPy wires still exhibit useful volume changes at the nanoscale. Nanowires with a 50 nm diameter and a length of approximately 6 µm, are fabricated by chemical polymerization using track-etched polycarbonate membranes as templates. Their actuation response as a function of oxidation state is investigated by electrochemical AFM (atomic force microscopy). An estimate of the minimum actuation force is made, based on the displacement of the AFM cantilever.

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