Transcription Factor Networks in Embryonic and Neural Stem Cells:

__Abstract__ The genetic material of any organism is also referred to as the genome and is passed on from generation to generation. The genome contains the hereditary information that is needed to construct the organism and to ensure its survival. This information is encoded in the form of deoxyribonucleic acid (DNA). DNA consists of two complementary strands of consecutively arranged nucleotides, composed of the nucleobase adenine (A), thymine (T), guanine (G) or cytosine (C). Due to selective pairing (A pairs to T, and G to C) they form a double helical structure which was first revealed by Watson and Crick in 1953 1. This discovery led to a revolution in genomic research that over 50 years later resulted in the first sequenced draft of the human genome 2. The diploid human genome comprises roughly 2 x 3 billion nucleotides which are divided over 22 paired chromosomes and the two sex chromosomes. In the genome are units, referred to as genes, that code for proteins or non-coding RNA mol

An Analysis of Medication Adherence in a Large Outpatient Population During the COVID-19 Pandemic Using a Novel Value-Based Pharmacy System

Background:Adherence to a medication regimen is defined as taking the medication as directed by the prescriber. Adherence is critical to achieve the desired therapeutic outcomes. Medication adherence has not been examined in large outpatient populations since the onset of the COVID-19 pandemic. A novel outpatient value-based pharmacy system (VPS) was used to collect adherence data from a large, outpatient population. The aim of this descriptive study was to analyze the reasons, medication classes, and diagnoses associated with nonadherence. Materials and Methods:Telepharmacist-documented adherence data from a large (n = 6,479) outpatient population that received remote consultation during the COVID-19 pandemic (August 1, 2020–November 28, 2022) were considered for this study. The adherence data were compiled within the VPS. Results:The overall rate of patients reporting at least one incident of nonadherence to their medication regimens was 21.5%. Medications used to treat hypertension, type 2 diabetes, and hyperlipidemia were least adhered to. Statins, beta-2 agonists, and corticosteroids were least adhered to. The most common reasons for nonadherence included knowledge gaps regarding therapy, forgetfulness, and side effects. Discussion:This represents the first descriptive analyses of adherence metrics in a large outpatient population during the COVID-19 pandemic. Polypharmacy, prevalence of diagnosis, and medication side effect profile may have contributed to the results observed. This study demonstrates the ability of a VPS to document key data to better inform the health care team. Elucidating adherence metrics in such populations may allow pharmacists and prescribers to identify subpopulations that require further education and management

Identity of the Qingdao algal bloom

In early July 2008, news agencies worldwide reported on a vast algal bloom that was threatening the upcoming Olympic sailing events in Qingdao, China. The identity of the culpable alga, however, remained undiscussed. We have identified the alga that caused the bloom by means of morphological and molecular data, including sequence data of the plastid encoded large subunit ribulose 1,5-bisphosphate carboxylase gene (rbcL) and the nuclear encoded rDNA internal transcribed spacer (ITS) region. The bloom-forming alga falls within the morphological limits of the green seaweed Ulva prolifera O.F. Muller ('Enteromorpha prolifera (O.F. Muller) J. Agardh') but our phylogenetic analyses show that it forms a clade with representatives of the Ulva linza-procera-prolifera (LPP) complex. The Chinese rbcL sequences are identical to those of specimens collected from Japan, New Zealand, Finland and Portugal, suggesting that the taxon is widely distributed. rDNA ITS sequences showed a close affinity with Japanese isolates of the species complex. The Qingdao bloom is a typical illustration of a green tide, which occurs increasingly along several coasts worldwide

Mammalian TIMELESS Is Involved in Period Determination and DNA Damage-Dependent Phase Advancing of the Circadian Clock

The transcription/translation feedback loop-based molecular oscillator underlying the generation of circadian gene expression is preserved in almost all organisms. Interestingly, the animal circadian clock proteins CRYPTOCHROME (CRY), PERIOD (PER) and TIMELESS (TIM) are strongly conserved at the amino acid level through evolution. Within this evolutionary frame, TIM represents a fascinating puzzle. While Drosophila contains two paralogs, dTIM and dTIM2, acting in clock/photoreception and chromosome integrity/photoreception respectively, mammals contain only one TIM homolog. Whereas TIM has been shown to regulate replication termination and cell cycle progression, its functional link to the circadian clock is under debate. Here we show that RNAi-mediated knockdown of TIM in NIH3T3 and U2OS cells shortens the period by 1 hour and diminishes DNA damage-dependent phase advancing. Furthermore, we reveal that the N-terminus of TIM is sufficient for interaction with CRY1 and CHK1 as well for homodimerization, and the C-terminus is necessary for nuclear localization. Interestingly

EcR recruits dMi-2 and increases efficiency of dMi-2-mediated remodelling to constrain transcription of hormone-regulated genes

Gene regulation by steroid hormones plays important roles in health and disease. In Drosophila, the hormone ecdysone governs transitions between key developmental stages. Ecdysone-regulated genes are bound by a heterodimer of ecdysone receptor (EcR) and Ultraspiracle. According to the bimodal switch model, steroid hormone receptors recruit corepressors in the absence of hormone and coactivators in its presence. Here we show that the nucleosome remodeller dMi-2 is recruited to ecdysone-regulated genes to limit transcription. Contrary to the prevalent model, recruitment of the dMi-2 corepressor increases upon hormone addition to constrain gene activation through chromatin remodelling. Furthermore, EcR and dMi-2 form a complex that is devoid of Ultraspiracle. Unexpectedly, EcR contacts the dMi-2 ATPase domain and increases the efficiency of dMi-2-mediated nucleosome remodelling. This study identifies a non-canonical EcR-corepressor complex with the potential for a direct regulation of ATP-dependent nucleosome remodelling by a nuclear hormone receptor

Exportin 4 mediates a novel nuclear import pathway for Sox family transcription factors

SRY and other Sox-type transcription factors are important developmental regulators with various implications in human disease. In this study, we identified Exp4 (exportin 4) as an interaction partner of Sox2 in mouse embryonic stem cells and neural progenitors. We show that, besides its established function in nuclear export, Exp4 acts as a bona fide nuclear import receptor for Sox2 and SRY. Thus, Exp4 is an example of a nuclear transport receptor carrying distinct cargoes into different directions. In contrast to a published study, we observed that the import activity of Imp-α (importin-a) isoforms toward Sox2 is negligible. Instead, we found that Imp9 and the Imp-β/7 heterodimer mediate nuclear import of Sox2 in parallel to Exp4. Import signals for the three pathways overlap and include conserved residues in the Sox2 high-mobility group (HMG) box domain that are also critical for DNA binding. This suggests that nuclear import of Sox proteins is facilitated by several parallel import pathways

Competency-based (CanMEDS) residency training programme in radiology: systematic design procedure, curriculum and success factors

Based on the CanMEDS framework and the European Training Charter for Clinical Radiology a new radiology curriculum was designed in the Netherlands. Both the development process and the resulting new curriculum are presented in this paper. The new curriculum was developed according to four systematic design principles: discursiveness, hierarchical decomposition, systematic variation and satisficing (satisficing is different from satisfying; in this context, satisficing means searching for an acceptable solution instead of searching for an optimal solution). The new curriculum is organ based with integration of radiological diagnostic techniques, comprises a uniform national common trunk followed by a 2-year subspecialisation, is competency outcome based with appropriate assessment tools and techniques, and is based on regional collaboration among radiology departments. The application of the systematic design principles proved successful in producing a new curriculum approved by all authorities. The principles led to a structured, yet flexible, development process in which creative solutions could be generated and adopters (programme directors, supervisors and residents) were highly involved. Further research is needed to empirically test the components of the new curriculum

Latitude, temperature, and habitat complexity predict predation pressure in eelgrass beds across the Northern Hemisphere

Latitudinal gradients in species interactions are widely cited as potential causes or consequences of global patterns of biodiversity. However, mechanistic studies documenting changes in interactions across broad geographic ranges are limited. We surveyed predation intensity on common prey (live amphipods and gastropods) in communities of eelgrass (Zostera marina) at 48 sites across its Northern Hemisphere range, encompassing over 370 of latitude and four continental coastlines. Predation on amphipods declined with latitude on all coasts but declined more strongly along western ocean margins where temperature gradients are steeper. Whereas in situ water temperature at the time of the experiments was uncorrelated with predation, mean annual temperature strongly positively predicted predation, suggesting a more complex mechanism than simple increased metabolic activity at the time of predation. This large-scale biogeographic pattern was modified by local habitat characteristics; predation declined with higher shoot density both among and within sites. Predation rates on gastropods, by contrast, were uniformly low and varied little among sites. The high replication and geographic extent of our study not only provides additional evidence to support biogeographic variation in intensity, but also insight into the mechanisms that relate temperature and biogeographic gradients in species interactions

Proteins that bind regulatory regions identified by histone modification chromatin immunoprecipitations and mass spectrometry

The locations of transcriptional enhancers and promoters were recently mapped in many mammalian cell types. Proteins that bind those regulatory regions can determine cell identity but have not been systematically identified. Here we purify native enhancers, promoters or heterochromatin from embryonic stem cells by chromatin immunoprecipitations (ChIP) for characteristic histone modifications and identify associated proteins using mass spectrometry (MS). 239 factors are identified and predicted to bind enhancers or promoters with different levels of activity, or heterochromatin. Published genome-wide data indicate a high accuracy of location prediction by ChIP-MS. A quarter of the identified factors are important for pluripotency and includes Oct4, Esrrb, Klf5, Mycn and Dppa2, factors that drive reprogramming to pluripotent stem cells. We determined the genome-wide binding sites of Dppa2 and find that Dppa2 operates outside the classical pluripotency network. Our ChIP-MS method provides a detailed read-out of the transcriptional landscape representative of the investigated cell type