Owing to the prevalence of the JAK2V617F mutation in myeloproliferative neoplasms (MPNs), its constitutive activity, and ability to recapitulate the MPN phenotype in mouse models, JAK2V617F kinase is ...an attractive therapeutic target. We report the discovery and initial characterization of the orally bioavailable imidazopyridazine, LY2784544, a potent, selective and ATP-competitive inhibitor of janus kinase 2 (JAK2) tyrosine kinase. LY2784544 was discovered and characterized using a JAK2-inhibition screening assay in tandem with biochemical and cell-based assays. LY2784544 in vitro selectivity for JAK2 was found to be equal or superior to known JAK2 inhibitors. Further studies showed that LY2784544 effectively inhibited JAK2V617F-driven signaling and cell proliferation in Ba/F3 cells (IC50=20 and 55 nM, respectively). In comparison, LY2784544 was much less potent at inhibiting interleukin-3-stimulated wild-type JAK2-mediated signaling and cell proliferation (IC50=1183 and 1309 nM, respectively). In vivo, LY2784544 effectively inhibited STAT5 phosphorylation in Ba/F3-JAK2V617F-GFP (green fluorescent protein) ascitic tumor cells (TED50=12.7 mg/kg) and significantly reduced (P<0.05) Ba/F3-JAK2V617F-GFP tumor burden in the JAK2V617F-induced MPN model (TED50=13.7 mg/kg, twice daily). In contrast, LY2784544 showed no effect on erythroid progenitors, reticulocytes or platelets. These data suggest that LY2784544 has potential for development as a targeted agent against JAK2V617F and may have properties that allow suppression of JAK2V617F-induced MPN pathogenesis while minimizing effects on hematopoietic progenitor cells.
Background:
Escherichia coli
β-hydroxydecanoyl thiol ester dehydrase (dehydrase) is essential to the biosynthesis of unsaturated fatty acids, by shunting a 10-carbon intermediate from the saturated ...fatty acid pathway into the unsaturated fatty acid pathway. Dehydrase catalyzes reactions of dehydration and of double-bond isomerization on 10-carbon thiol esters of acyl carrier protein (ACP). The aim of this work is to elucidate mechanisms for the two enzymatic reactions, which occur in an unusual bifunctional active site, and to understand the specificity of the enzyme for substrates with 10-carbon fatty acyl chains.
Results Crystal structures at 2.0 å resolution for free dehydrase and for the enzyme modified by its classic, mechanism-based inactivator, 3-decynoyl-
N-acetylcysteamine, have been determined. Dehydrase is a symmetric dimer with an unusual
α+
β ‘hot dog’ fold. Each of the two independent active sites is located between the two subunits of the enzyme, and is a tunnel-shaped pocket completely isolated from the general solvent. Side chains of histidine from one subunit and aspartic acid from the other are the only potentially reactive protein groups in the active site.
Conclusion A two-base mechanism by which the histidine and aspartic acid together catalyze dehydration and isomerization reactions is consistent with the active-site structure. The unique topology of the protein fold and the identification of the active-site components reveal features of predictive value for another enzyme, FabZ, which may be the non-specific dehydratase involved in elongation of fatty acyl chains. A positively charged area surrounding the entrance to the active site, which could interact with the negatively charged ACP, was also found.
Protein kinase C (PKC) is a family of closely related serine and threonine kinases. Overactivation of some PKC isozymes has been postulated to occur in several disease states, including diabetic ...complications. Selective inhibition of overactivated PKC isozymes may offer a unique therapeutic approach to disease states such as diabetic retinopathy. A novel series of 14-membered macrocycles containing a N−N‘-bridged bisindolylmaleimide moiety is described. A panel of eight cloned human PKC isozymes (α, βI, βII, γ, δ, ε, ζ, η) was used to identify the series and optimize the structure and associated activity relationship. The dimethylamine analogue LY333531 (1), (S)-13-(dimethylamino)methyl-10,11,14,15-tetrahydro-4,9:16,21-dimetheno-1H,13H-dibenzoe,kpyrrolo3,4-h1,4,13oxadiazacyclohexadecene-1,3(2H)-dione, inhibits the PKCβI (IC50 = 4.7 nM) and PKCβII (IC50 = 5.9 nM) isozymes and was 76- and 61-fold selective for inhibition of PKCβI and PKCβII in comparison to PKCα, respectively. The additional analogues described in the series are also selective inhibitors of PKCβ. LY333531 (1) exhibits ATP dependent competitive inhibition of PKCβI and is selective for PKC in comparison to other ATP dependent kinases (protein kinase A, calcium calmodulin, caesin kinase, src tyrosine kinase). The cellular activity of the series was assessed using bovine retinal capillary endothelial cells. Retinal endothelial cell dysfunction has been implicated in the development of diabetic retinopathy. Plasminogen activator activity stimulated by a phorbol ester (4β-phorbol 12,13-dibutyrate) in endothelial cells was inhibited by the compounds in the series with ED50 values ranging from 7.5 to 0.21 μM. A comparison of the PKC isozyme and related ATP dependent kinase inhibition profiles is provided for the series and compared to the profile for staurosporine, a nonselective PKC inhibitor. The cellular activity of the series is compared with that of the kinase inhibitor staurosporine.
Avatars or agents are digitized self-representations of a player in mediated environments. While using agents to navigate through mediated environments, players form bonds with their self-agents or ...characters, a process referred to as identification. Identification can involve automatic, but temporary, self-concept “shifts in implicit self-perceptions” (Klimmt et al.,
2010
, p. 323) of the media user by adopting or emphasizing the action choices on behalf of the social expectation of the avatar in the mediated environment. In the current study, we test the possibility that users' identification with video game avatars–a bond built between avatars and players- would account for subsequent behavior changes. We did so by using 3-month longitudinal data involving a narratively-based serious game: Socially Optimized Learning in Virtual Environments (SOLVE), a 3D-interactive game designed to reduce risky sexual behaviors among young men who have sex with men (
n
= 444). Results show that video game identification predicts both the reduction of risky sexual behaviors over time, and reduction in the number of non-primary partners with whom risky sex occurs. And when players identify with the game character, they tend to make healthier choices, which significantly mediates the link between video game identification and reduction of risky behaviors.
Posterior hip precautions have been routinely prescribed to decrease dislocation rates. The purpose of this study was to determine whether the absence of hip precautions improved early recovery after ...total hip arthroplasty via the posterolateral approach.
Patients undergoing total hip arthroplasty via the posterolateral approach at 3 centers were enrolled. Patients meeting the selection criteria were randomized to standard hip precautions (SHP) or no hip precautions (NHP) for 6 weeks following surgery. HOOS Jr, Health State visual analog score, and rate of pain scores were recorded preoperatively and in subsequent postoperative visits; dislocation episodes were also noted. Standard statistical analysis was performed.
From 2016 to 2017, 159 patients were randomized to SHP and 154 patients were randomized to NHP. Controlling for the center at which the surgery was performed, the only difference in outcome scores between the 2 groups was at 2 weeks; the NHP group had a lower HOOS Jr score when compared to the SHP group (P = .03). There was no difference in outcome scores at any other time points when compared to preoperative assessments. In the SHP group, there were 2 recorded dislocations (1.3%) and 1 in the NHP group (0.7%; P = .62).
In this multicenter, randomized, controlled study, the absence of hip precautions in the postoperative period did not improve subjective outcomes which may be explained by the self-limiting behavior of NHP patients. Furthermore, with the numbers available for the study, there was no difference in the rate of dislocation between the 2 groups.
Causal inference and generalizability both matter. Historically, systematic designs emphasize causal inference, while representative designs focus on generalizability. Here, we suggest a ...transformative synthesis - Systematic Representative Design (SRD) - concurrently enhancing both causal inference and "built-in" generalizability by leveraging today's intelligent agent, virtual environments, and other technologies. In SRD, a "default control group" (DCG) can be created in a virtual environment by representatively sampling from real-world situations. Experimental groups can be built with systematic manipulations onto the DCG base. Applying systematic design features (e.g., random assignment to DCG versus experimental groups) in SRD affords valid causal inferences. After explicating the proposed SRD synthesis, we delineate how the approach concurrently advances generalizability and robustness, cause-effect inference and precision science, a computationally-enabled cumulative psychological science supporting both "bigger theory" and concrete implementations grappling with tough questions (e.g., what is context?) and affording rapidly-scalable interventions for real-world problems.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Systematic Representative Design (SRD), enabled by today's technologies leverages many of the strengths of past designs into a new synthesis affording the capacity for both causal inference and ...generalizability to everyday life (GEL). In doing so, it could help better integrate past and ongoing empirical research findings in psychology. Generally, the commentaries were positive and thought-provoking. Delightfully, they gave us new opportunities to both clarify misunderstandings as well as further address the feasibility of this approach.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Matrix-assisted laser-desorption ionization followed by ion-mobility separation and time-of-flight mass analysis (MALDI-IM-TOFMS) has been used to characterize native and chemically modified DNA ...oligonucleotides up to eight bases in length. Mobility resolution between 20 and 30 can be used to separate oligonucleotides of different length, but not to differentiate between isomers or even different compositions of the same length. MALDI-IM-TOFMS does, however, have additional utility in the analysis of mixtures of DNA oligonucleotides and peptides, because these classes of molecules can be distinguished on the basis of differences in their mobility. Oligonucleotide sequencing is also possible by MALDI-IM-TOFMS. Ion signals corresponding to nucleobase losses, w-type, and y-type fragments were identified by use of differences in ion mobility. MALDI-IM-TOFMS was also used to resolve DNA-platinum adducts from the corresponding unmodified oligonucleotides.
This study compared the rates of hospitalization from two psychiatric emergency services which were similar except that one service had an extended evaluation unit, or holding area, allowing up to 24 ...hours of evaluation. The rate of hospitalization from the service with the extended evaluation unit was 36%; the rate from the other service was 52%. The difference in admission rates was related to the availability of the extended evaluation unit, which made it possible for many patients to avoid rather than merely postpone admission to the hospital. Clinical determinants of admission and of successful treatment in the unit were also reviewed.
A sample of 309 police officers in Cincinnati and Hamilton County, Ohio, were interviewed about their contacts with mentally ill individuals and about their need for various kinds of information and ...assistance from the mental health system. During a one-month period, almost 60 percent of the officers had responded to at least one call involving a presumably mentally ill person, and 42 percent had responded to more than one such call. Twenty-two percent had dealt with a presumably mentally ill person who was also mentally retarded. Police officers indicated that they most needed access to information about an individual's past history of violence on suicide attempts, and quick on-site assistance by mental health professionals in assessing suicidal or hostile mentally ill persons.
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