2,984 research outputs found
Influence of DNA-protein interactions on purification and assembly of virus-like particles
Modular virus-like-particles (VLPs), presenting foreign antigens on their surface, are promising candidates for a wide range of future vaccines. A viable production pathway is the expression and purification of viral structural proteins and their subsequent in vitro assembly into VLPs, in a bioprocess environment. One promising approach is the use of murine polyomavirus major capsid protein VP1 as a carrier of modular epitopes from vaccine targets. This platform technology uses E. coli as an expression system and showed promising results in creating VLP vaccines candidates directed at influenza, Group A Streptococcus and other infectious pathogens. However, like other viral capsomeres and viral structures, purification using chromatography techniques remains a challenge as conventional high capacity ion exchange matrices suffer from low binding capacities.
In this work the role of DNA-protein interaction during the purification of VLP precursor capsomeres is investigated. It is found that modular VP1 capsomeres coat DNA molecules forming large DNA-protein complexes that are unable to access the pores of chromatographic resins resulting in inefficient column binding. By increasing the salt concentration of the buffer above 0.3M NaCl, the DNA-protein complexes dissociate. At intermediate salt concentrations salt-tolerant ion-exchange resins can be used to efficiently capture and purify VP1 capsomeres, as the salt breaks the aggregates but is insufficient to interfere with binding to the salt-tolerant matrix. This approach increases the binding capacity of VLP precursor proteins by at least a magnitude over published laboratory-based methods.
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Controlled-release carvedilol in the management of systemic hypertension and myocardial dysfunction
Cardiovascular disease is the leading cause of death worldwide. Within the treatment armamentarium, beta-blockers have demonstrated efficacy across the spectrum of cardiovascular disease – from modification of a risk factor (ie, hypertension) to treatment after an acute event (ie, myocardial infarction). Recently, the use of beta-blockers as a first-line therapy in hypertension has been called into question. Moreover, beta-blockers as a class are saddled with a misperception of having poor tolerability. However, vasodilatory beta-blockers such as carvedilol have a different hemodynamic action that provides the benefits of beta-blockade with the addition of vasodilation resulting from alpha 1-adrenergic receptor blockade. Vasodilation reduces total peripheral resistance, which may produce an overall positive effect on tolerability. Recently, a new, controlled-release carvedilol formulation has been developed that provides the clinical efficacy of carvedilol but is indicated for once-daily dosing. This review presents an overview of the clinical and pharmacologic carvedilol controlled-release data
The KOALA-study: study protocol for a comprehensive study of cognitive biases in adolescent anorexia nervosa patients compared to healthy and clinical controls
BACKGROUND Anorexia nervosa (AN) is characterized by dysfunctional cognitions including cognitive biases at various levels of information processing. However, less is known about the specificity of these biases, i.e., if they occur for eating-disorder-related information alone or also for non-eating-disorder-related emotional information in AN patients (content-specificity) and if they are unique to individuals with AN or are also shown by individuals with other mental disorders (disorder-specificity). METHODS The present study systematically assesses cognitive biases in 12-18-year-old female adolescents with AN on three levels of information processing (attention, interpretation, and memory) and with regard to two types of information content (eating-disorder-related, i.e., stimuli related to body weight and shape, and non-eating-disorder-related). To address not only content- but also disorder-specificity, adolescents with AN will be compared not only to a healthy control group but also to a clinical control group (adolescents with major depression or particular anxiety disorders). Cognitive biases are assessed within a single experimental paradigm based on the Scrambled Sentences Task. During the task eye movements are recorded in order to assess attention biases while interpretation biases are derived from the behavioural outcome. An incidental free recall test afterwards assesses memory biases. We expect adolescents with AN to show more pronounced negative cognitive biases on all three levels of information processing and for both types of content compared to healthy adolescents. In addition, we expect the specificity of biases to translate into differential results for the two types of content: AN patients are expected to show stronger biases for disorder-related stimuli but similar or less pronounced biases for non-disorder-related stimuli compared to the clinical control group. DISCUSSION This is the first study to comprehensively assess cognitive biases in adolescents with AN. It will have essential implications not only for cognitive-behavioural models of AN but also for subsequent studies aiming to modify cognitive biases in this population, thereby addressing important maintaining factors already at an early stage of the disorder
Family, friends, and feelings: the role of relationships to parents and peers and alexithymia in adolescents with anorexia nervosa
Background
Anorexia nervosa (AN) is associated with impairments in socio-emotional functioning, including difficulties in interpersonal relationships as well as alexithymia (difficulties identifying and describing one’s emotions). Although the onset of the disorder is mostly in adolescence, a developmental period in which interpersonal relationships to parents as well as peers undergo major changes, only few studies have investigated the quality of interpersonal relationships in adolescent AN patients. Furthermore, the mechanisms linking poor relationship quality to eating disorder psychopathology are not yet clarified, albeit some research suggests that alexithymia might play a pivotal role. The aims of the present study were investigating the quality of interpersonal relationships to parents and peers in adolescents with AN compared to healthy adolescents as well as exploring the mediating role of alexithymia in the association between relationship quality and eating disorder symptoms.
Methods
Self-report questionnaires were used to assess relationship quality (Inventory of Parent and Peer Attachment) and alexithymia (Toronto Alexithymia Scale) in 12–18 year old female adolescents with AN (n = 35) in comparison to healthy adolescents (n = 40).
Results
Adolescents with AN reported lower relationship quality to both of their parents and to peers compared to healthy controls. Relationship quality scores were negatively correlated to alexithymia as well as eating disorder symptoms. Alexithymia fully meditated the association between eating disorder symptoms and relationship quality to parents and partially mediated the association between eating disorder symptoms and relationship quality to peers.
Conclusion
The results indicate difficulties in interpersonal relationships among adolescents with AN and emphasize the role of peer relationships for adolescents’ eating disorder psychopathology. Alexithymia seems to play an important role in explaining the link between quality of relationships and eating disorder psychopathology. Results suggest that treatment should not only focus on family relationships but also address relationships to peers as well as adolescents’ competence in identifying and dealing with their emotions
Look me in the eyes! A preliminary study on eye‐contact in adolescents with anorexia nervosa
Objective
Anorexia nervosa (AN) is often associated with impairments in the socio-emotional domain. Avoidance of eye-contact may underlie some of these difficulties and has been found in adults with AN in several studies. This study aimed to clarify whether adolescents with AN also show reduced eye-contact when viewing social stimuli, that is, faces.
Methods
In this cross-sectional study, girls aged 12–18 years with AN (n = 38) were compared with a clinical (girls with depression and/or anxiety disorders; n = 30) and a healthy (n = 36) control group. Eye-contact was operationalised as maintenance of visual attention to the eye-area of faces showing different emotional expressions (happy, angry, afraid, sad, neutral), recorded via eye-tracking.
Results
Contrary to our expectations, we did not find adolescents with AN to dwell less on the eye-area than control groups; instead, we found preliminary evidence for increased attention to the eye-area in the AN group compared to the healthy control group.
Conclusions
The results suggest that reduced eye-contact found in adult AN samples is not (yet) present in adolescents with AN but may develop with the prolonged duration of the disorder. However, replication and longitudinal studies are needed to confirm this assumption
Bicyclic Phenyl-Ethynyl Architectures: Synthesis of a 1,4-Bis(phenylbuta-1,3-diyn-1-yl) Benzene Banister
The novel diacetylene bridged terphenylic macrocycle 1 is presented and discussed in the context of rotationally restricted "Gelander" oligomers. The 1,4-bis(phenylbuta-1,3-diyn-1-yl) benzene bridge of diacetylene 1 is significantly longer than its terphenyl backbone, forcing the bridge to bend around the central pylon. The synthesis of molecule 1 is based to a large extent on acetylene scaffolding strategies, profiting from orthogonal alkyne protection groups to close both macrocyclic subunits by oxidative acetylene coupling sequentially. The spatial arrangement and the dynamic enantiomerization process of the bicyclic target structure 1 are analyzed. In-depth NMR investigations not only reveal an unexpected spatial arrangement with both oligomer strands bent alongside the backbone, but also display the limited stability of the model compound in the presence of molecular oxygen
Bicyclic Phenyl–Ethynyl Architectures: Synthesis of a 1,4-Bis(phenylbuta-1,3-diyn-1-yl) Benzene Banister
The novel diacetylene bridged terphenylic macrocycle 1 is presented and discussed in the context of rotationally restricted “Geländer” oligomers. The 1,4‐bis(phenylbuta‐1,3‐diyn‐1‐yl) benzene bridge of diacetylene 1 is significantly longer than its terphenyl backbone, forcing the bridge to bend around the central pylon. The synthesis of molecule 1 is based to a large extent on acetylene scaffolding strategies, profiting from orthogonal alkyne protection groups to close both macrocyclic subunits by oxidative acetylene coupling sequentially. The spatial arrangement and the dynamic enantiomerization process of the bicyclic target structure 1 are analyzed. In‐depth NMR investigations not only reveal an unexpected spatial arrangement with both oligomer strands bent alongside the backbone, but also display the limited stability of the model compound in the presence of molecular oxygen
Function Of Human α3β4α5 Nicotinic Acetylcholine Receptors Is Reduced By The β5(D398N) Variant
Genome-wide studies have strongly associated a non-synonymous polymorphism (rs16969968) that changes the 398th amino acid in the nAChR α5 subunit from aspartic acid to asparagine (D398N), with greater risk for increased nicotine consumption. We have used a pentameric concatemer approach to express defined and consistent populations of α3β4α5 nAChR in Xenopus oocytes. α5(Asn-398; risk) variant incorporation reduces ACh-evoked function compared with inclusion of the common α5(Asp-398) variant without altering agonist or antagonist potencies. Unlinked α3, β4, and α5 subunits assemble to form a uniform nAChR population with pharmacological properties matching those of concatemeric α3β4* nAChRs. α5 subunit incorporation reduces α3β4* nAChR function after coinjection with unlinked α3 and β4 subunits but increases that of α3β4α5 versus α3β4-only concatemers. α5 subunit incorporation into α3β4* nAChR also alters the relative efficacies of competitive agonists and changes the potency of the non-competitive antagonist mecamylamine. Additional observations indicated that in the absence of α5 subunits, free α3 and β4 subunits form at least two further subtypes. The pharmacological profiles of these free subunit α3β4-only subtypes are dissimilar both to each other and to those of α3β4α5 nAChR. The α5 variant-induced change in α3β4α5 nAChR function may underlie some of the phenotypic changes associated with this polymorphism. © 2012 by The American Society for Biochemistry and Molecular Biology, Inc
The New Zealand Kauri (Agathis Australis) Research Project: A Radiocarbon Dating Intercomparison of Younger Dryas Wood and Implications for IntCal13
We describe here the New Zealand kauri (Agathis australis) Younger Dryas (YD) research project, which aims to undertake Δ14C analysis of ~140 decadal floating wood samples spanning the time interval ~13.1–11.7 kyr cal BP. We report 14C intercomparison measurements being undertaken by the carbon dating laboratories at University of Waikato (Wk), University of California at Irvine (UCI), and University of Oxford (OxA). The Wk, UCI, and OxA laboratories show very good agreement with an interlaboratory comparison of 12 successive decadal kauri samples (average offsets from consensus values of –7 to +4 14C yr). A University of Waikato/University of Heidelberg (HD) intercomparison involving measurement of the YD-age Swiss larch tree Ollon505, shows a HD/Wk offset of ~10–20 14C yr (HD younger), and strong evidence that the positioning of the Ollon505 series is incorrect, with a recommendation that the 14C analyses be removed from the IntCal calibration database
Entwicklung und Validierung eines Inventars zur Employability nach dem dualen Studium
Die Potenziale eines dualen Studiums führen zur Annahme, dass Absolventen und Absolventinnen über eine hohe Employability verfügen und sie damit gute Chancen bei der Erhaltung und Aufrechterhaltung einer Beschäftigung nach dem Studium haben. Um diese Annahme zu überprüfen, wurde ein Inventar entwickelt und mit Studierenden der Dualen Hochschule Baden-Württemberg erprobt. Zur Analyse der Daten wurden Hauptkomponentenanalysen, konfirmatorische Faktorenanalysen und ein Mann-Whitney-U-Test eingesetzt. In zwei Studien wurde ein reliables und valides Instrument entwickelt. Die Ergebnisse werden vor dem Hintergrund ihrer Anwendung in der Praxis diskutiert
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