Nucleosomes are stable DNA-histone protein complexes that must be unwrapped and disassembled for genome expression, replication, and repair. Histone posttranslational modifications (PTMs) are major regulatory factors of these nucleosome structural changes, but the molecular mechanisms associated with PTM function remains poorly understood. Here we demonstrate that histone PTMs within distinct structured regions of the nucleosome directly regulate the inherent dynamic properties of the nucleosome. Precise PTMs were introduced into nucleosomes by chemical ligation. Single molecule magnetic tweezers measurements determined that only PTMs near the nucleosome dyad increase the rate of histone release in unwrapped nucleosomes. In contrast, FRET and restriction enzyme analysis reveal that only PTMs throughout the DNA entry-exit region increase unwrapping and enhance transcription factor binding to nucleosomal DNA. These results demonstrate that PTMs in separate structural regions of the nucleosome control distinct dynamic events, where the dyad regulates disassembly while the DNA entry-exit region regulates unwrapping. These studies are consistent with the conclusion that histone PTMs may independently influence nucleosome dynamics and associated chromatin functions.histone acetylation | chromatin dynamics | native chemical ligation
Background Early adherence is key to successful depression treatment, but nearly 60% of patients discontinue antidepressants within three months. Our study aimed to determine factors associated with poor early adherence to antidepressants in a large diverse sample of patients. Methods Six Mental Health Research Network healthcare systems contributed data for adults with depression and a new antidepressant start, defined by a washout period of at least 270 days, between 1/1/2010 and 12/31/2012. Pharmacy fill and self-reported race/ethnicity data were obtained from the electronic medical record. Patients had early adherence if they had a second antidepressant fill within 180 days of the first. We used logistic regression to investigate the relationship between early adherence and patient characteristics. Results 177,469 adult patients had 184,967 new episodes of depression with a filled antidepressant prescription. Patients refilled their antidepressants within 180 days in 71% of episodes. Race/ethnicity was a strong predictor of early adherence, with patients from racial/ethnic minorities less likely (adjusted odd ratios 0.50–0.59) to refill their antidepressants than were non-Hispanic whites or Native Americans/Alaskan Natives. Other apparent predictors of early adherence, including neighborhood income, gender and prior mental health hospitalizations, were no longer significant in the fully adjusted model. Conclusions Race/ethnicity was a robust predictor of early antidepressant adherence, with minority groups other than Native Americans/Alaskan Natives less likely to be adherent. Further research is needed to determine whether early nonadherence in specific minority populations is intentional, due to side effects or patient preference, or unintentional and appropriate for targeted interventions to improve adherence.
Nucleosomes contain ∼146 bp of DNA wrapped around a histone protein octamer that controls DNA accessibility to transcription and repair complexes. Posttranslational modification (PTM) of histone proteins regulates nucleosome function. To date, only modest changes in nucleosome structure have been directly attributed to histone PTMs. Histone residue H3(T118) is located near the nucleosome dyad and can be phosphorylated. This PTM destabilizes nucleosomes and is implicated in the regulation of transcription and repair. Here, we report gel electrophoretic mobility, sucrose gradient sedimentation, thermal disassembly, micrococcal nuclease digestion and atomic force microscopy measurements of two DNA–histone complexes that are structurally distinct from nucleosomes. We find that H3(T118ph) facilitates the formation of a nucleosome duplex with two DNA molecules wrapped around two histone octamers, and an altosome complex that contains one DNA molecule wrapped around two histone octamers. The nucleosome duplex complex forms within short ∼150 bp DNA molecules, whereas altosomes require at least ∼250 bp of DNA and form repeatedly along 3000 bp DNA molecules. These results are the first report of a histone PTM significantly altering the nucleosome structure.
Blackberry fruits are recognized as functional foods while blackberry leaves are outside this classification and they also contain active compounds with health-promoting potential. Therefore, the aim of this study was the phytochemical analysis of blackberry leaves of varieties (Chester, Loch Ness, Loch Tay and Ruczaj) and screening of their biological activity (antioxidant potential, possibility of inhibition of enzymes, anti-inflammatory and microbial activity). The following compounds from selected groups: phenolic acids (caffeic acid, ellagic acid, gallic acid, syringic acid), flavonols (quercetin, kaempferol) and their glycosides (rutin, isoquercetin, hyperoside) and flavon-3-ols (catechin, epicatechin) were chromatographically determined in the aqueous and hydroalcoholic leaves extracts. All tested blackberry leaves extracts showed antioxidant effects, but the highest compounds content (TPC = 101.31 mg GAE/g) and antioxidant activity (e.g., DPPH IC50 = 57.37 μg/mL; ABTS IC50 = 24.83 μg/mL; CUPRAC IC50 = 62.73 μg/mL; FRAP IC50 = 39.99 μg/mL for hydroalcoholic extracts) was indicated for the Loch Tay variety. Blackberry leaf extracts’ anti-inflammatory effect was also exceptionally high for the Loch Tay variety (IC50 = 129.30 μg/mL), while leaves extracts of the Loch Ness variety showed a significant potential for microbial activity against Lactobacillus spp. and Candida spp. Summarizing, the best multidirectional pro-health effect was noted for leaves extracts of Loch Tay variety.
Implementation of pharmaceutical care (PC) in Poland is of great importance to patients, who, on the one hand, often follow complex pharmacological treatment regimens recommended by several physicians of different specialties, and, on the other, take up the decision on self-treatment due to availability of OTC medications. The aim of the present study was to assess the opinion of both patients and physicians about implementation of PC service in Polish community pharmacies. A cross sectional study was carried out from September 2009 to September 2010 by a pharmacist (author of the study) on the basis of an anonymous questionnaire, where demand of physicians (n = 104) and patients (n = 202) for implementation of PC in a community pharmacy was assessed. The study was planned to determine the relationship between implementation of PC, cost and time of this service and patients' and physicians' socio-economic information. Responding patients (85.64%) and physicians (76.92%) unanimously confirmed the need for implementation of PC. Most people convinced of the service implementation were 88.89% of physicians under the age of 35 and all the respondents were over 65 years of age (p = 0.027), just as 93.33% with service lesser than 5 years and 73.68% of respondents working a maximum of 20 years (p = 0.023). Mainly according to 90.00% of physicians with specialty in internal medicine and 92.59% of physicians of the group "Others" (p = 0.012), PC should be implemented in pharmacies. Women more frequently than men reckoned that appointments with a pharmacist should last up to 15 min (p = 0.012). According to 77.78% of the youngest physicians and 83.33% of the oldest ones, appointments should last from 5 to 15 min (p = 0.049), and a similar opinion was shared by 80.77% of physicians without specialty and 77.78% of physicians of the group "Others" (p = 0.0009). According to patients, the mean cost of the visit should be USD 7. Physicians most often assessed the mean cost of the appointment at USD 14. This study provides new data about implementation of PC in Poland. The increased patients' and physicians' willingness to benefit from this service provides pharmacists with opportunities to develop PC in community pharmacies.
Polygoni cuspidati root is a resveratrol-rich source with anti-inflammatory, angiogenic and neuroprotective effects. The raw material was standardized for the content of resveratrol, for which there is a special justification for administration within the oral mucosa. To improve the solubility of resveratrol and to assure its high content in plant material, an ultrasound-assisted extraction method was applied. The addition of cyclodextrin was found to increase the extraction efficiency of resveratrol (from 13 to 297 µg per 1 g of plant material in case of 50% ethanol extracts) and enhanced its antioxidant activity as compared to pure Polygoni cuspidati extract/resveratrol. Cyclodextrin plays the role of a functional extract regarding technological properties (increasing the extraction of resveratrol from the extract, improving mucoadhesive properties). Therefore, the aim of this study was to develop mucoadhesive tablets containing combinations of the Polygoni cuspidati extract with a cyclodextrin carrier for buccal delivery. The tests sequentially included extract preparation and characterization of its physical and biological properties and then formulation studies with a broad description of the prototype properties. The test results indicate that cyclodextrin increases the efficiency of resveratrol extraction from Polygoni cuspidati rhizome, which is a rich source of resveratrol, and its extract enclosed in a mucoadhesive tablet guarantees prolonged action at the site of administration.
The properties of the saliva of patients with inflammatory bowel disease (IBD) are poorly recognized. Likewise, the diagnostic potential of saliva for differentiating various forms of IBD is largely unexplored. Therefore, we compared the concentrations of several parameters in unstimulated whole mixed saliva collected in a standardized manner from patients with active IBD unresponsive to conventional therapy. The samples were received from 27 patients with Crohn’s disease (CD), 24 patients with ulcerative colitis (UC), and 51 healthy individuals. Compared to the controls, the salivary concentrations of S100A8/calprotectin, myeloperoxidase, and IgA were significantly decreased in both CD and UC patients. In addition, patients with UC had decreased levels of TNF-R1 and decreased catalase activity. Interestingly, the concentrations of myeloperoxidase and TNF-R1 showed a high differentiation potential for CD and UC (AUC = 0.690 and 0.672, respectively). All these findings are discussed in the context of host defense in the oral cavity, patients’ prior treatment regimens, and smoking habits.
The lateral intercellular spaces of Necturus gallbladder epithelium were punctured with double-barrelled ion selective microelectrodes in order to determine the ion concentrations of lateral space fluid and the contribution of the lateral spaces to transepithelial resistance. Neither under control conditions, nor after diluting the bathing fluids to increase the rate of volume absorption, nor during passage of direct current of 200 microA/cm2, were any reliable concentration differences observed between lateral space fluid and external bathing fluids. These observations suggest that water can follow salt transport without requiring osmotic concentration gradients of greater than 1 or 2 mosmol/l and indicate that recently observed high values of water permeability must still be considered as underestimates. After developing a test to recognize and exclude leaky punctures, the contribution of the lateral spaces to transepithelial resistance could be determined. It amounted to around 29%. This value agrees well with results from recent impedance measurements which were performed under control conditions in the same preparation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.