Identification and characterization of an irreversible inhibitor of CDK2

Irreversible inhibitors that modify cysteine or lysine residues within a protein kinase ATP binding site offer, through their distinctive mode of action, an alternative to ATP-competitive agents. 4-((6-(Cyclohexylmethoxy)- 9H-purin-2-yl)amino)benzenesulfonamide (NU6102) is a potent and selective ATP-competitive inhibitor of CDK2 in which the sulfonamide moiety is positioned close to a pair of lysine residues. Guided by the CDK2/NU6102 structure, we designed 6-(cyclohexylmethoxy)-N-(4-(vinylsulfonyl)phenyl)-9H-purin-2-amine (NU6300), which binds covalently to CDK2 as shown by a co-complex crystal structure. Acute incubation with NU6300 produced a durable inhibition of Rb phosphorylation in SKUT-1B cells, consistent with it acting as an irreversible CDK2 inhibitor. NU6300 is the first covalent CDK2 inhibitor to be described, and illustrates the potential of vinyl sulfones for the design of more potent and selective compounds

Factors associated with dropout during recruitment and follow-up periods of a mHealth-based randomized controlled trial for Mobile.Net to encourage treatment adherence for people with serious mental health problems

Background: Clinical trials are the gold standard of evidence-based practice. Still many papers inadequately report methodology in randomized controlled trials (RCTs), particularly for mHealth interventions for people with serious mental health problems. To ensure robust enough evidence, it is important to understand which study phases are the most vulnerable in the field of mental health care. Objective: We mapped the recruitment and the trial follow-up periods of participants to provide a picture of the dropout predictors from a mHealth-based trial. As an example, we used a mHealth-based multicenter RCT, titled “Mobile.Net,” targeted at people with serious mental health problems. Methods: Recruitment and follow-up processes of the Mobile.Net trial were monitored and analyzed. Recruitment outcomes were recorded as screened, eligible, consent not asked, refused, and enrolled. Patient engagement was recorded as follow-up outcomes: (1) attrition during short message service (SMS) text message intervention and (2) attrition during the 12-month follow-up period. Multiple regression analysis was used to identify which demographic factors were related to recruitment and retention. Results: We recruited 1139 patients during a 15-month period. Of 11,530 people screened, 36.31% (n=4186) were eligible. This eligible group tended to be significantly younger (mean 39.2, SD 13.2 years, P<.001) and more often women (2103/4181, 50.30%) than those who were not eligible (age: mean 43.7, SD 14.6 years; women: 3633/6514, 55.78%). At the point when potential participants were asked to give consent, a further 2278 refused. Those who refused were a little older (mean 40.2, SD 13.9 years) than those who agreed to participate (mean 38.3, SD 12.5 years; t1842=3.2, P<.001). We measured the outcomes after 12 months of the SMS text message intervention. Attrition from the SMS text message intervention was 4.8% (27/563). The patient dropout rate after 12 months was 0.36% (4/1123), as discovered from the register data. In all, 3.12% (35/1123) of the participants withdrew from the trial. However, dropout rates from the patient survey (either by paper or telephone interview) were 52.45% (589/1123) and 27.8% (155/558), respectively. Almost all participants (536/563, 95.2%) tolerated the intervention, but those who discontinued were more often women (21/27, 78%; P=.009). Finally, participants’ age (P<.001), gender (P<.001), vocational education (P=.04), and employment status (P<.001) seemed to predict their risk of dropping out from the postal survey. Conclusions: Patient recruitment and engagement in the 12-month follow-up conducted with a postal survey were the most vulnerable phases in the SMS text message-based trial. People with serious mental health problems may need extra support during the recruitment process and in engaging them in SMS text message-based trials to ensure robust enough evidence for mental health care

Making Friends in the Rainforest: Negrito Adaptation to Risk and Uncertainty

The so-called negritos adapt not just to a tropical forest environment but also to an environment characterized by perturbations and fluctuations. As with other hunter-gatherers in the region and, indeed, throughout the world, they use both social and ecological methods to enhance their chances of survival in this changing environment: socially, they have developed networks of trading and marriage partners; ecologically, they maintain patches of key resources that are available for future harvesting. As evidenced in the case of the Batek (Orang Asli), patterns of forest structure and composition are sometimes direct outcomes of intentional resource concentration and enrichment strategies. While little of the above is controversial anthropologically, what has drawn some debate is the nature of the relationship with partner societies. Conventional wisdom posits relations of inequality between foragers and others : foragers and farmers are often construed as hierarchical dyads where foragers supply products or labor to farmers in exchange for agricultural harvests and other trade goods. This kind of adaptation appears to be one of divergent specialization. However, there are cases, such as in the relationship between Batek and Semaq Beri, where both societies follow a roughly similar mode of adaptation, and specialization has not materialized. In sum, while not denying that hierarchy and inequality exist, I suggest that they have to be contextualized within a larger strand of relationships that includes both hierarchy and egality. Further, such relationships are part of the general portfolio of risk reduction strategies, following which access to widely scattered environmental resources, and passage from one location to another, is enhanced not by competing with and displacing neighbors but by maintaining a flexible regime of friendly exchange partners

The CDK9 C-helix Exhibits Conformational Plasticity That May Explain the Selectivity of CAN508

Correct regulation of transcription is essential for maintaining a healthy cellular state. During transcription RNA polymerase II (Pol II) proceeds in a regulated manner through several transitions to ensure appropriate control of synthesis and enable correct processing of the pre-RNA. Shortly after initiation Pol II is caused to pause by the binding of factors, DSIF and NELF. To enable transition of Pol II into the elongation phase CDK9/cyclin T phosphorylates the C-terminal domain (CTD) of Pol II, DSIF and NELF. This phosphorylation releases the paused state and provides an alternative set of post-transcriptional modifications on the CTD to generate a binding platform for elongation, histone modifying and termination factors. CDK9/cyclin T is itself regulated within multicomponent complexes. A small activated complex, containing Brd4, recruits CDK9/cyclin T to active sites of transcription, thereby promoting the elongation of transcription. The role of CDK9/cyclin T in the regulation of transcription has resulted in its validation as a drug target against several disease states including cancer, HIV and cardiac hypertrophy.In this thesis, I present the crystallographic structures of a series of 2-amino-4-heteroaryl-pyrimidine compounds and the roscovitine derivative, (S)-CR8, bound to CDK9/cyclin T and CDK2/cyclin A. In combination with thermal denaturation data and kinetic analysis, these structures have suggested chemical modifications that might be made to increase the CDK9 specificity of these compounds. I have also validated the use of a mutated form of cyclin T for use in the development of CDK9/cyclin T inhibitors.In addition, I present both structural and kinetic analysis of the Brd4-CDK9/cyclin T interaction. I show that C-terminal fragments of Brd4 enhance the in vitro kinase activity of CDK9/cyclin T against the Pol II CTD. Furthermore, I demonstrate that this enhancement may be inhibited by Plk1-mediated phosphorylation of Brd4. Finally, I show that Brd4 binds to a site that spans CDK9 and cyclin T and I propose detailed molecular models of the Brd4-cyclin T interaction.This thesis is not currently available via ORA

Identification of a novel ligand for the ATAD2 bromodomain with selectivity over BRD4 through a fragment growing approach

Structure-guided expansion of a fragment hit for the ATAD2 bromodomain enabled improvement in ATAD2 inhibition and selectivity over BRD4.</p

Schneiderian first rank symptoms: Reconfirmation of high specificity for schizophrenia

The prevalence of Schneiderian first-rank symptoms (FRS) in 294 consecutive admissions to a research unit was evaluated with reference to their diagnostic distribution (SADS/RDC). Thirty-five of 58 patients with schizophrenia had FRS, as compared to nine of 190 patients with major depressive disorder. All patients with two or more FRS received a diagnosis of schizophrenia. In the absence of organic or toxic etiology, the specificity of FRS for schizophrenia was 95% and their predictive value was 90%. These findings indicate that FRS should be regarded as strongly suggestive of schizophrenia in the absence of an organic syndrome.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65636/1/j.1600-0447.1987.tb02807.x.pd

In vitro and in vivo activity and cross resistance profiles of novel ruthenium (II) organometallic arene complexes in human ovarian cancer.

Ruthenium complexes offer the potential of reduced toxicity, a novel mechanism of action, non-cross resistance and a different spectrum of activity compared to platinum containing compounds. Thirteen novel ruthenium(II) organometallic arene complexes have been evaluated for activity (in vitro and in vivo) in models of human ovarian cancer, and cross-resistance profiles established in cisplatin and multi-drug-resistant variants. A broad range of IC50 values was obtained (0.5 to >100 microM) in A2780 parental cells with two compounds (RM175 and HC29) equipotent to carboplatin (6 microM), and the most active compound (HC11) equipotent to cisplatin (0.6 microM). Stable bi-dentate chelating ligands (ethylenediamine), a more hydrophobic arene ligand (tetrahydroanthracene) and a single ligand exchange centre (chloride) were associated with increased activity. None of the six active ruthenium(II) compounds were cross-resistant in the A2780cis cell line, demonstrated to be 10-fold resistant to cisplatin/carboplatin by a mechanism involving, at least in part, silencing of MLH1 protein expression via methylation. Varying degrees of cross-resistance were observed in the P-170 glycoprotein overexpressing multi-drug-resistant cell line 2780AD that could be reversed by co-treatment with verapamil. In vivo activity was established with RM175 in the A2780 xenograft together with non-cross-resistance in the A2780cis xenograft and a lack of activity in the 2780AD xenograft. High activity coupled to non cross-resistance in cisplatin resistant models merit further development of this novel group of anticancer compounds

Interprofessional education through shadowing experiences in multi-disciplinary clinical settings

The World Health Organization has recently added Interprofessional Education (IPE) to its global health agenda recognizing it as a necessary component of all health professionals' education. We suggest mandatory interprofessional shadowing experiences as a mechanism to be used by chiropractic institutions to address this agenda. IPE initiatives of other professions (pharmacy and medicine) are described along with chiropractic. This relative comparison of professions local to our jurisdiction in Ontario, Canada is made so that the chiropractic profession may take note that they are behind other health care providers in implementing IPE