Identification and characterization of a temperature sensitive chlorotic soybean mutant.

Screening a transposon-mutagenized soybean population led to the discovery of a recessively inherited chlorotic phenotype. This "vir1" phenotype results in smaller stature, weaker stems, and a smaller root system with smaller nodules. Genome sequencing identified 15 candidate genes with mutations likely to result in a loss of function. Amplicon sequencing of a segregating population was then used to narrow the list to a single candidate mutation, a single-base change in Glyma.07G102300 that disrupts splicing of the second intron. Single cell transcriptomic profiling indicates that this gene is expressed primarily in mesophyll cells and RNA sequencing data indicates it is upregulated in germinating seedlings by cold stress. Previous studies have shown that mutations to Os05g34040, the rice homolog of Glyma.07G102300, produced a chlorotic phenotype that was more pronounced in cool temperatures. Growing soybean vir1 mutants at lower temperatures also resulted in a more severe phenotype. In addition, transgenic expression of wild type Glyma.07G102300 in the knockout mutant of the Arabidopsis homolog At4930720 rescues the chlorotic phenotype, further supporting the hypothesis that the mutation in Glyma.07G102300 is causal of the vir1 phenotype.

"I shall not poison my child with your human experiment": Investigating predictors of parents' hesitancy about vaccinating younger children (<12) in Canada.

BACKGROUND: Since the approval of SARS-CoV-2 vaccines for younger children (those under the age of 12), uptake has been low. Despite widespread vaccination among older children and adults, these trends may undermine public health efforts to manage future waves of SARS-CoV-2 or spill over into other childhood vaccines. The objectives of this study were to understand parents' intentions to vaccinate their children (under age 12) against SARS-CoV-2, and to explore reasons for and against SARS-CoV-2 vaccination. METHODS: A representative sample of parents of school-aged children (ages 3-11 years) from Canada's four largest provinces were invited in June 2021 to complete a survey on the impact of COVID-19 on schooling. The survey included specific questions on parents' intentions to vaccinate their child(ren) against SARS-CoV-2. Multinomial regression models were run to estimate associations between demographic factors, political affiliation and voting, concerns about individual / family health and vaccination intention. RESULTS: A total of 74.0 % of parents (n = 288) intended to vaccinate their children with the SARS-CoV-2 vaccine, 18.3 % (n = 71) did not intend to vaccinate and 7.7 % (n = 30) were unsure. The strongest predictor of parental hesitancy was whether a parent had themselves been vaccinated. Other factors including past voting behaviour, dissatisfaction with the government's response to the pandemic, and relatively less concern about contracting SARS-CoV-2 were also correlated with hesitancy. Parents of older children were more likely to indicate plans to vaccinate their child(ren). Analysis of the reasons for hesitancy showed parents are concerned about the safety and side effects of the vaccine, as well as with processes of testing and approval. INTERPRETATION: A considerable proportion of Canadian parents of younger school-aged children (ages 3-11) were unsure and/or hesitant about vaccinating their children against SARS-CoV-2. As well, a much larger proportion who are not necessarily hesitant have also not had their children vaccinated. Given the evolving nature of SARS-CoV-2, including the continued emergence of new variants, reaching younger children will be important for population health. Health providers should continue to work with government institutions to ensure clear communication regarding the safety, efficacy, and importance of child vaccines for reaching public health goals.

Interventions to Reduce Parental Substance Use, Domestic Violence and Mental Health Problems, and Their Impacts Upon Children's Well-Being: A Systematic Review of Reviews and Evidence Mapping.

INTRODUCTION: Children exposed to parental intimate partner violence and abuse, mental illness, and substance use experience a range of problems which may persist into adulthood. These risks often co-occur and interact with structural factors such as poverty. Despite increasing evidence, it remains unclear how best to improve outcomes for children and families experiencing these adversities and address the complex issues they face. AIMS AND METHODS: Systematic review of systematic reviews. We searched international literature databases for systematic reviews, from inception to 2021, to provide an evidence overview of the range and effectiveness of interventions to support children and families where these parental risk factors had been identified. RESULTS: Sixty-two systematic reviews were included. The majority (n = 59) focused on interventions designed to address single risk factors. Reviews mostly focused on parental mental health (n = 38) and included psychological interventions or parenting-training for mothers. Only two reviews assessed interventions to address all three risk factors in combination and assessed structural interventions. Evidence indicates that families affected by parental mental health problems may be best served by integrated interventions combining therapeutic interventions for parents with parent skills training. Upstream interventions such as income supplementation and welfare reform were demonstrated to reduce the impacts of family adversity. CONCLUSION: Most intervention approaches focus on mitigating individual psychological harms and seek to address risk factors in isolation, which presents potentially significant gaps in intervention evidence. These interventions may not address the cumulative impacts of co-occurring risks, or social factors that may compound adversities.

I Felt Like I was Going Crazy: Understanding Mother's and Young Children's Educational Experiences at Home During COVID-19.

The COVID-19 disruptions to children's education have been a major issue for families. This study examined how demographic, family, and mental health characteristics of 375 low-income children and their mothers from the City of Toronto were associated with children's educational experiences at home during COVID-19. Many mothers (82.3%) reported that they and their children (80.0%) experienced challenges related to children's education at home during the pandemic. However, a small percentage of mothers (1.1%) reported that this mode of learning was better for them and their children (4.3%). The most frequently reported challenges faced by mothers was taking on the role of a teacher (43.7%) and balancing their children's remote learning with other responsibilities (19.4%). The most frequently mentioned challenges faced by children was that children lacked both motivation (21.1%) and socialization (21.1%) and had difficulty focusing (26.9%). White mothers from households with higher income and with a higher number of adults in the home reported that their children experienced higher levels of challenges related to their education at home. Maternal and child challenges with children's education at home were also related to higher levels of maternal and child mental health challenges. Our findings suggest that the online educational experiences set up following the onset of the pandemic were difficult for many children and mothers to implement in the home. Given the significant associations of these challenges with child and maternal mental health, we encourage educators to provide flexibility, empathy, and support with learning from home to both children and mothers.

Parental intimate partner violence and abuse during the COVID-19 pandemic: Learning from remote and hybrid working to influence future support.

OBJECTIVES: The COVID-19 pandemic has exacerbated intimate partner violence and abuse. Incidents of intimate partner violence and abuse have increased as a result of household tensions due to enforced coexistence (multiple national lockdowns and working from home practices), economic stress related to loss of income, the disruption of social and protective networks and the decreased access to support services. This study aimed to understand how female survivors of parental intimate partner violence and abuse have experienced the adapted multi-agency response to intimate partner violence and abuse during the pandemic and consider learning from remote and hybrid working to influence future support. METHOD: This study adopted a qualitative research design, utilizing semi-structured interviews and a focus group. Data collection took place between March and September 2021. In total, 17 female survivors of intimate partner violence and abuse took part in the project; we conducted the semi-structured interviews via telephone (n = 9) and conducted an online focus group (n = 8). RESULTS: Findings identified that services for those experiencing intimate partner violence and abuse need to be innovative, flexible and adaptable and 'reach out' to survivors rather than waiting for survivors to 'reach in' and ask for support. Findings show that the digital space highlights 'missed opportunities' for engagement with both professionals and peers and the potential for digital poverty is a key implication, which risks entrenching existing inequalities. CONCLUSION: In-depth consideration needs to be given to the design, delivery and evaluation of online interventions and provision of support to improve access and acceptability of services, maximize their effectiveness and to support the safety of survivors.

Examining the impact of social stressor stimuli in eliciting physiological reactivity in children and adolescents with autism spectrum disorder: a systematic review and meta-analysis protocol.

INTRODUCTION: Stress is not experienced the same by everyone. Some individuals, such as individuals with autism spectrum disorder (ASD), are at risk of heightened sensitivity to stress responses. ASD is a neurodevelopmental disorder commonly characterised by deficits in social communication and social interaction. Among different stressor stimuli, social stressors are particularly worth our attention due to the social and communication challenges inherent in ASD. This study aims to systematically evaluate different social stressor stimuli in eliciting physiological reactivity in ASD, focusing on the children and adolescent population. METHODS AND ANALYSIS: We designed a study protocol for this study and submitted it to PROSPERO for systematic review registration. Any studies with children and adolescents with ASD between the ages of 0 and 18 in clinical and community settings will be included. All types of social stressor interventions will be included. The outcome of interest will include studies with physiological activity of the participants being measured, for example, measures related to autonomic functioning, electrodermal functioning and cortisol level. The primary literature sources will be across four electronic databases: MEDLINE, Embase, PsycInfo and CINAHL in August 2021. The second source of literature will be across grey literature, including ProQuest Dissertations & Theses Global and across clinical trial registries in August 2021. Hand searching of references will be performed on the reference lists of all included studies. Two volunteers pursuing postgraduate-level studies will independently search and screen potential studies for eligibility. Finally, all references considered by hand searching will be reviewed by two researchers. The methodological quality of the research will be assessed by adopting the quality assessment used by a previous study. The assessment consists of four primary categories: descriptive validity, internal validity, external validity and statistical conclusion validity. ETHICS AND DISSEMINATION: No ethical approval is required for this study. Results will be disseminated through conferences and publications in relevant peer-reviewed journals. PROSPERO REGISTRATION NUMBER: CRD42021244039.

Exploring Mental Health Professionals' Experiences of Intimate Partner Violence-Related Training: Results From a Global Survey.

Intimate partner violence (IPV) is a global public health problem that has been shown to lead to serious mental health consequences. Due to its frequent co-occurrence with psychiatric disorders, it is important to assess for IPV in mental health settings to improve treatment planning and referral. However, lack of training in how to identify and respond to IPV has been identified as a barrier for the assessment of IPV. The present study seeks to better understand this IPV-related training gap by assessing global mental health professionals' experiences of IPV-related training and factors that contribute to their likelihood of receiving training. Participants were French-, Spanish-, and Japanese-speaking psychologists and psychiatrists (N = 321) from 24 nations differing on variables related to IPV, including IPV prevalence, IPV-related norms, and IPV-related laws. Participants responded to an online survey asking them to describe their experiences of IPV-related training (i.e., components and hours of training) and were asked to rate the frequency with which they encountered IPV in clinical practice and their level of knowledge and experience related to relationship problems; 53.1% of participants indicated that they had received IPV-related training. Clinicians from countries with relatively better implemented laws addressing IPV and those who encountered IPV more often in their regular practice were more likely to have received training. Participants who had received IPV-related training, relative to those without training, were more likely to report greater knowledge and experience related to relationship problems. Findings suggest that clinicians' awareness of IPV and the institutional context in which they practice are related to training. Training, in turn, is associated with subjective appraisals of knowledge and experience related to relationship problems. Increasing institutional efforts to address IPV (e.g., implementing IPV legislation) may contribute to improved practices with regard to IPV in mental health settings.

Evaluating the Relationship Between Intimate Partner Violence-Related Training and Mental Health Professionals' Assessment of Relationship Problems.

Intimate partner violence (IPV) is a serious public health problem associated with increased risk of developing mental health conditions. Assessment of IPV in mental health settings is important for appropriate treatment planning and referral; however, lack of training in how to identify and respond to IPV presents a significant barrier to assessment. To address this issue, the World Health Organization (WHO) advanced a series of evidence-based recommendations for IPV-related training programs. This study examines the relationship between mental health professionals' experiences of IPV-related training, including the degree to which their training resembles WHO training recommendations, and their accuracy in correctly identifying relationship problems. Participants were psychologists and psychiatrists (N = 321) from 24 countries who agreed to participate in an online survey in French, Japanese, or Spanish. They responded to questions regarding their IPV-related training (i.e., components and hours of training) and rated the presence or absence of clinically significant relationship problems and maltreatment (RPM) and mental disorders across four case vignettes. Participants who received IPV-related training, and whose training was more recent and more closely resembled WHO training recommendations, were more likely than those without training to accurately identify RPM when it was present. Clinicians regardless of IPV-related training were equally likely to misclassify normative couple issues as clinically significant RPM. Findings suggest that IPV-related training assists clinicians in making more accurate assessments of patients presenting with clinically significant relationship problems, including IPV. These data inform recommendations for IPV-related training programs and suggest that training should be repeated, multicomponent, and include experiential training exercises, and guidelines for distinguishing normative relationship problems from clinically significant RPM.

Heterogeneity in maternal and child mental health responses to the COVID-19 pandemic.

We used latent profile analysis on a longitudinal dataset to examine changes in maternal and child mental health during COVID-19 and factors that may protect against declines in mental health. Participants were 183 low-income mothers (M = 36 years) with young children (M = 5.31 years) in the City of Toronto with data collected prior to and during the pandemic in 2020. Mothers reported on their own stress, anxiety and depression and their children's emotional, conduct, hyperactivity, peer, and prosocial problems at both timepoints. We found heterogeneity in mental health changes, with 5 distinct patterns of change for mothers, and 4 distinct patterns of change for children during COVID-19. The majority (83%) of mothers experienced significant declines in at least one aspect of mental health. In contrast, the majority of children (65%) experienced either no change or improvements in mental health. Interestingly, patterns of change across these groups were not differentiated by demographic characteristics such as income, education, and family composition. However, for mothers, a higher degree of satisfaction with social support was associated with membership in a profile with better mental health both prior to, and during the pandemic. For children, having a stable history of early childhood education, and care was associated with membership in a profile that showed improvements in mental health during the pandemic. We discuss how our results support the need for proactive and global interventions for at-risk families with raised mental health concerns, and the benefits that stable early childhood education and care may provide for young children.

A global field study of the international classification of diseases (ICD-11) mood disorders clinical descriptions and diagnostic guidelines.

BACKGROUND: We report results of an internet-based field study evaluating the diagnostic guidelines for ICD-11 mood disorders. Accuracy of clinicians' diagnostic judgments applying draft ICD-11 as compared to the ICD-10 guidelines to standardized case vignettes was assessed as well as perceived clinical utility. METHODS: 1357 clinician members of the World Health Organization's Global Clinical Practice Network completed the study in English, Spanish, Japanese or Russian. Participants were randomly assigned to apply ICD-11 or ICD-10 guidelines to one of eleven pairs of case vignettes. RESULTS: Clinicians using the ICD-11 and ICD-10 guidelines achieved similar levels of accuracy in diagnosing mood disorders depicted in vignettes. Those using the ICD-11 were more accurate in identifying depressive episode in recurrent depressive disorder. There were no statistically significant differences detected across classifications in the accuracy of identifying dysthymic or cyclothymic disorder. Circumscribed problems with the proposed ICD-11 guidelines were identified including difficulties differentiating bipolar type I from bipolar type II disorder and applying revised severity ratings to depressive episodes. Clinical utility of ICD-11 bipolar disorders was found to be significantly lower than for ICD-10 equivalent categories. LIMITATIONS: Standardized case vignettes were manipulated to evaluate specific changes. The degree of accuracy of clinicians' diagnostic judgments may not reflect clinical decision-making with patients. CONCLUSIONS: Alignment of the ICD-11 with current research appears to have been achieved without sacrificing diagnostic accuracy or clinical utility though specific training may be necessary as ICD-11 is implemented worldwide. Areas in which the ICD-11 guidelines did not perform as intended resulted in further revisions.

School reintegration following hospitalisation for children with medical complexity and chronic disease diagnoses: a scoping review protocol.

INTRODUCTION: Schools play a significant role in children's social, emotional and intellectual well-being. For children with medical complexity (CMC) and chronic disease diagnoses (CDD), an absence from school due to prolonged hospitalisation places them at risk for greater social exclusion and poorer academic outcomes than their healthy counterparts. Processes that support the school reintegration of children with complex and chronic medical conditions currently lack consistency and identified evidence-based practices. This scoping review aims to integrate the relevant literature on current reintegration procedures as well as assess stakeholders' perceived challenges related to children with CMC and CDD's return to school following hospitalisation. Finally, information will be synthesised regarding parental and child involvement in reintegration strategies. METHODS AND ANALYSIS: The current scoping review follows the five-stage framework proposed by Arksey and O'Malley (2005). The search syntax will be applied in Medline, Web of Science, PsycInfo, Education Resource, ERIC, CINAHL and SocIndex. Peer-reviewed journal articles will be included without the restriction of publication year or language. However, only children and adolescents aged 4-18 with CMC and CDD, who have been out of school for 2 weeks or more and reintegrated into a non-hospital school setting will be included. Articles will be screened by two authors based on the outlined eligibility criteria. Data will be summarised qualitatively and where applicable, visualisation techniques such as tables, graphs and figures will be implemented to address approaches, strategies and outcomes related to reintegration to school following hospitalisation. ETHICS AND DISSEMINATION: The current study comprises available publications and does not collect primary data. For this reason, ethics approval is not necessary. The results of this scoping review will be prepared and submitted for publication in a peer-reviewed journal and presented at future conferences to key stakeholders focusing on educational accessibility and inclusion.

A highly porous and conductive composite gate electrode for OTFT sensors.

Ionic/protonic to electronic transducers based on organic thin film transistors have shown great promise for applications in bioelectronic interface devices and biosensors, and development of materials that exhibit mixed ionic/electronic conduction are an essential part of these devices. In this work, we investigated the proton sensing properties of an all solid-state and low voltage operating organic thin film transistor (OTFT) that uses the organic mixed conductor poly(3,4-ethylenedioxythiophene) doped with poly(styrene sulfonate) (PEDOT:PSS) as the gate electrode. To address the limited sensitivity due to the lack of porosity in PEDOT:PSS base sensors, we proposed a composite gate electrode material composed of PEDOT:PSS and proton conducting mesoporous SO3H-Si-MCM-41 nanoparticles for improved proton sensitivity. The composite gate electrode doubles the proton sensitivity of the OTFT, indicating a clear advantage of adding SO3H-Si-MCM-41 in the PEDOT:PSS gate. Moreover, the OTFTs with the composite gate electrode maintained OTFT characteristics similar to that of the PEDOT:PSS gated OTFT. A detailed and systematic study of the effect of variation in the composition of PEDOT:PSS:SO3H-Si-MCM-41 on OTFT characteristics and sensing properties is carried out. Our results open up the possibility of combining inorganic nanomaterials with organic conductors in the development of highly efficient bioelectronic sensing platforms.

A case-controlled field study evaluating ICD-11 proposals for relational problems and intimate partner violence.

Background/Objective: Intimate partner relationship problems and intimate partner abuse and neglect - referred to in this paper as "relational problems and maltreatment" - have substantial and well-documented impact on both physical and mental health. However, classification guidelines, such as those found in the International Classification of Diseases (ICD-10), are vague and unlikely to support consistent application. Revised guidelines proposed for ICD-11 are much more operationalized. We used standardized clinical vignette conditions with an international panel of clinicians to test if ICD-11 changes resulted in improved classification accuracy. Method: English-speaking mental health professionals (N = 738) from 65 nations applied ICD-10 or ICD-11 (proposed) guidelines with experimentally manipulated case presentations of presence or absence of (a) individual mental health diagnoses and (b) relational problems or maltreatment. Results: ICD-11, compared with ICD-10, guidelines resulted in significantly better classification accuracy, although only in the presence of co-morbid mental health problems. Clinician factors (e. g., gender, language, world region) largely did not impact classification performance. Conclusions: Despite being considerably more explicated, raters' performance with ICD-11 guidelines reveals training issues that should be addressed prior to the release of ICD-11 in 2018 (e. g., overriding the guidelines with pre-existing archetypes for relationship problems and physical and psychological abuse).

Antecedentes/Objetivo: Los problemas en la relación de pareja y relacionados con abuso y negligencia de pareja, referidos como "problemas relacionales y maltrato", tienen un importante impacto en la salud física y mental. Sin embargo, guías de clasificación, como la Clasificación Internacional de Enfermedades (CIE-10), son vagas y su aplicación es inconsistente. Las guías propuestas por el CIE-11 son más operacionales. Junto con un panel de clínicos, utilizamos viñetas clínicas estandarizadas, para evaluar si los cambios propuestos por CIE-11 mejoraban la precisión de la clasificación. Método: Profesionales de la salud de habla inglesa (N=738) de 65 naciones compararon la aplicación del CIE-10 y CIE-11 en casos experimentales, estableciendo presencia o ausencia de (a) diagnósticos individuales de salud mental y (b) problemas de relaciones o maltrato. Resultados: CIE-11 tuvo resultados significativamente más precisos, aunque solo en presencia de comorbilidades de salud mental. Factores como género, idioma y región no presentaron mayor alteración. Conclusiones: Aunque el CIE-11 está mejor explicado, este estudio revela problemas de capacitación que deberían abordarse antes de su publicación en 2018.

A case-controlled field study evaluating ICD-11 proposals for relational problems and intimate partner violence / Estudio de campo con casos controlados para evaluar propuestas de la CIE-11 en problemas relacionales y de violencia de pareja

BACKGROUND/OBJECTIVE: Intimate partner relationship problems and intimate partner abuse and neglect - referred to in this paper as "relational problems and maltreatment" - have substantial and well-documented impact on both physical and mental health. However, classification guidelines, such as those found in the International Classification of Diseases (ICD-10), are vague and unlikely to support consistent application. Revised guidelines proposed for ICD-11 are much more operationalized. We used standardized clinical vignette conditions with an international panel of clinicians to test if ICD-11 changes resulted in improved classification accuracy. METHOD: English-speaking mental health professionals (N = 738) from 65 nations applied ICD-10 or ICD-11 (proposed) guidelines with experimentally manipulated case presentations of presence or absence of (a) individual mental health diagnoses and (b) relational problems or maltreatment. RESULTS: ICD-11, compared with ICD-10, guidelines resulted in significantly better classification accuracy, although only in the presence of co-morbid mental health problems. Clinician factors (e. g., gender, language, world region) largely did not impact classification performance. CONCLUSIONS: Despite being considerably more explicated, raters' performance with ICD-11 guidelines reveals training issues that should be addressed prior to the release of ICD-11 in 2018 (e. g., overriding the guidelines with pre-existing archetypes for relationship problems and physical and psychological abuse)

ANTECEDENTES/OBJETIVO: Los problemas en la relación de pareja y relacionados con abuso y negligencia de pareja, referidos como "problemas relacionales y maltrato", tienen un importante impacto en la salud física y mental. Sin embargo, guías de clasificación, como la Clasificación Internacional de Enfermedades (CIE-10), son vagas y su aplicación es inconsistente. Las guías propuestas por el CIE-11 son más operacionales. Junto con un panel de clínicos, utilizamos viñetas clínicas estandarizadas, para evaluar si los cambios propuestos por CIE-11 mejoraban la precisión de la clasificación. MÉTODO: Profesionales de la salud de habla inglesa (N=738) de 65 naciones compararon la aplicación del CIE-10 y CIE-11 en casos experimentales, estableciendo presencia o ausencia de (a) diagnósticos individuales de salud mental y (b) problemas de relaciones o maltrato. RESULTADOS: CIE-11 tuvo resultados significativamente más precisos, aunque solo en presencia de comorbilidades de salud mental. Factores como género, idioma y región no presentaron mayor alteración. CONCLUSIONES: Aunque el CIE-11 está mejor explicado, este estudio revela problemas de capacitación que deberían abordarse antes de su publicación en 2018

Effect of thermal annealing Super Yellow emissive layer on efficiency of OLEDs.

Thermal annealing of the emissive layer of an organic light emitting diode (OLED) is a common practice for solution processable emissive layers and reported annealing temperatures varies across a wide range of temperatures. We have investigated the influence of thermal annealing of the emissive layer at different temperatures on the performance of OLEDs. Solution processed polymer Super Yellow emissive layers were annealed at different temperatures and their performances were compared against OLEDs with a non-annealed emissive layer. We found a significant difference in the efficiency of OLEDs with different annealing temperatures. The external quantum efficiency (EQE) reached a maximum of 4.09% with the emissive layer annealed at 50 °C. The EQE dropped by ~35% (to 2.72%) for OLEDs with the emissive layers annealed at 200 °C. The observed performances of OLEDs were found to be closely related to thermal properties of polymer Super Yellow. The results reported here provide an important guideline for processing emissive layers and are significant for OLED and other organic electronics research communities.

Revisiting backward recall and benchmark memory effects: a reply to Bireta et al. (2010).

When participants are asked to recall lists of items in the reverse order, known as backward recall, several benchmark memory phenomena, such as the word length effect, are abolished (Bireta et al. Memory & Cognition 38:279-291, 2010). Bireta et al. (Memory & Cognition 38:279-291, 2010) suggested that in backward recall, reliance on order retention is increased at the expense of item retention, leading to the abolition of item-based phenomena. In a subsequent study, however, Guérard and Saint-Aubin (in press) showed that four lexical factors known to modulate item retention were unaffected by recall direction. In a series of five experiments, we examined the source of the discrepancy between the two studies. We revisited the effects of phonological similarity, word length, articulatory suppression, and irrelevant speech, using open and closed pools of words in backward and forward recall. The results are unequivocal in showing that none of these effects are influenced by recall direction, suggesting that Bireta et al.'s (Memory & Cognition 38:279-291, 2010) results are the consequence of their particular stimuli.

Structure-guided evolution of potent and selective CHK1 inhibitors through scaffold morphing.

Pyrazolopyridine inhibitors with low micromolar potency for CHK1 and good selectivity against CHK2 were previously identified by fragment-based screening. The optimization of the pyrazolopyridines to a series of potent and CHK1-selective isoquinolines demonstrates how fragment-growing and scaffold morphing strategies arising from a structure-based understanding of CHK1 inhibitor binding can be combined to successfully progress fragment-derived hit matter to compounds with activity in vivo. The challenges of improving CHK1 potency and selectivity, addressing synthetic tractability, and achieving novelty in the crowded kinase inhibitor chemical space were tackled by multiple scaffold morphing steps, which progressed through tricyclic pyrimido[2,3-b]azaindoles to N-(pyrazin-2-yl)pyrimidin-4-amines and ultimately to imidazo[4,5-c]pyridines and isoquinolines. A potent and highly selective isoquinoline CHK1 inhibitor (SAR-020106) was identified, which potentiated the efficacies of irinotecan and gemcitabine in SW620 human colon carcinoma xenografts in nude mice.

Aminopyrazine inhibitors binding to an unusual inactive conformation of the mitotic kinase Nek2: SAR and structural characterization.

We report herein the first systematic exploration of inhibitors of the mitotic kinase Nek2. Starting from HTS hit aminopyrazine 2, compounds with improved activity were identified using structure-based design. Our structural biology investigations reveal two notable observations. First, 2 and related compounds bind to an unusual, inactive conformation of the kinase which to the best of our knowledge has not been reported for other types of kinase inhibitors. Second, a phenylalanine residue at the center of the ATP pocket strongly affects the ability of the inhibitor to bind to the protein. The implications of these observations are discussed, and the work described here defines key features for potent and selective Nek2 inhibition, which will aid the identification of more advanced inhibitors of Nek2.

Identification by high-throughput screening of viridin analogs as biochemical and cell-based inhibitors of the cell cycle-regulated nek2 kinase.

Nek2 is a serine/threonine protein kinase that localizes to the centrosome and is implicated in mitotic regulation. Overexpression of Nek2 induces premature centrosome separation and nuclear defects indicative of mitotic errors, whereas depletion of Nek2 interferes with cell growth. As Nek2 expression is upregulated in a range of cancer cell lines and primary human tumors, inhibitors of Nek2 may have therapeutic value in cancer treatment. The authors used a radiometric proximity assay in a high-throughput screen to identify small-molecule inhibitors of Nek2 kinase activity. The assay was based on the measurement of the radiolabeled phosphorylated product of the kinase reaction brought into contact with the surface of wells of solid scintillant-coated microplates. Seventy nonaggregating hits were identified from approximately 73,000 compounds screened and included a number of toxoflavins and a series of viridin/wortmannin-like compounds. The viridin-like compounds were >70-fold selective for Nek2 over Nek6 and Nek7 and inhibited the growth of human tumor cell lines at concentrations consistent with their biochemical potencies. An automated mechanism-based microscopy assay in which centrosomes were visualized using pericentrin antibodies confirmed that 2 of the viridin inhibitors reduced centrosome separation in a human tumor cell line. The data presented show that pharmacological inhibition of Nek2 kinase results in the expected phenotype of disruption to centrosome function associated with growth inhibition and further supports Nek2 as a target for cancer drug discovery.

Identification and characterisation of 2-aminopyridine inhibitors of checkpoint kinase 2.

5-(Hetero)aryl-3-(4-carboxamidophenyl)-2-aminopyridine inhibitors of CHK2 were identified from high throughput screening of a kinase-focussed compound library. Rapid exploration of the hits through straightforward chemistry established structure-activity relationships and a proposed ATP-competitive binding mode which was verified by X-ray crystallography of several analogues bound to CHK2. Variation of the 5-(hetero)aryl substituent identified bicyclic dioxolane and dioxane groups which improved the affinity and the selectivity of the compounds for CHK2 versus CHK1. The 3-(4-carboxamidophenyl) substituent could be successfully replaced by acyclic omega-aminoalkylamides, which made additional polar interactions within the binding site and led to more potent inhibitors of CHK2. Compounds from this series showed activity in cell-based mechanistic assays for inhibition of CHK2.