Advances in understanding the mechanism of action of the auxin permease AUX1

In over 40 years of research on the cellular uptake of auxin it is somewhat chastening that we have elabourated little on the original kinetic descriptions of auxin uptake by plant cells made by Rubery and Sheldrake in 1974. Every aspect of that seminal work has been investigated in detail and the uptake activity they measured is now known to be attributed to the AUX1/LAX family of permeases. Recent pharmacological studies have defined the substrate specificity of AUX1, biochemical studies have evaluated its permeability to auxin in plant cell membranes, and rigourous kinetic studies have confirmed the affinity of AUX1 for IAA and synthetic auxins. Advances in genome sequencing have provided a rich resource for informatic analysis of the ancestry of AUX1 and the LAX proteins and, along with models of topology, suggest mechanistic links to families of eukaryotic proton co-transporters for which crystal structures have been presented. The insights gained from all the accumulated research reflect the brilliance of Rubery and Sheldrake’s early work, but recent biochemical analyses are starting to advance further our understanding of this vitally important family of auxin transport proteins

Refining a model of collaborative care for people with a diagnosis of bipolar, schizophrenia or other psychoses in England: a qualitative formative evaluation

This is the final version. Available on open access from BMC via the DOI in this recordAvailability of data and materials: Transcripts will not be shared in their entirety to protect the anonymity of service users and care partners delivering the intervention. However, requests for excerpts of the data will be considered on an individual basis. Please contact the corresponding author.Background Many people diagnosed with schizophrenia, bipolar or other psychoses in England receive the majority of their healthcare from primary care. Primary care practitioners may not be well equipped to meet their needs and there is often poor communication with secondary care. Collaborative care is a promising alternative model but has not been trialled specifically with this service user group in England. Collaborative care for other mental health conditions has not been widely implemented despite evidence of its effectiveness. We carried out a formative evaluation of the PARTNERS model of collaborative care, with the aim of establishing barriers and facilitators to delivery, identifying implementation support requirements and testing the initial programme theory. Methods The PARTNERS intervention was delivered on a small scale in three sites. Qualitative data was collected from primary and secondary care practitioners, service users and family carers, using semi-structured interviews, session recordings and tape-assisted recall. Deductive and inductive thematic analysis was carried out; themes were compared to the programme theory and used to inform an implementation support strategy. Results Key components of the intervention that were not consistently delivered as intended were: interaction with primary care teams, the use of coaching, and supervision. Barriers and facilitators identified were related to service commitment, care partner skills, supervisor understanding and service user motivation. An implementation support strategy was developed, with researcher facilitation of communication and supervision and additional training for practitioners. Some components of the intervention were not experienced as intended; this appeared to reflect difficulties with operationalising the intervention. Analysis of data relating to the intended outcomes of the intervention indicated that the mechanisms proposed in the programme theory had operated as expected. Conclusions Additional implementation support is likely to be required for the PARTNERS model to be delivered; the effectiveness of such support may be affected by practitioner and service user readiness to change. There is also a need to test the programme theory more fully. These issues will be addressed in the process evaluation of our full trial.National Institute for Health Research (NIHR

International perspectives on suboptimal patient-reported outcome trial design and reporting in cancer clinical trials: a qualitative study

Purpose: Evidence suggests that the patient-reported outcome (PRO) content of cancer trial protocols is frequently inadequate and non-reporting of PRO findings is widespread. This qualitative study examined the factors influencing suboptimal PRO protocol content, implementation, and reporting, and use of PRO data during clinical interactions. Methods: Semi-structured interviews were conducted with four stakeholder groups: (1) trialists and chief investigators; (2) people with lived experience of cancer; (3) international experts in PRO cancer trial design; (4) journal editors, funding panelists, and regulatory agencies. Data were analyzed using directed thematic analysis with an iterative coding frame. Results: Forty-four interviews were undertaken. Several factors were identified that could influenced effective integration of PROs into trials and subsequent findings. Participants described (1) late inclusion of PROs in trial design; (2) PROs being considered a lower priority outcome compared to survival; (3) trialists’ reluctance to collect or report PROs due to participant burden, missing data, and perceived reticence of journals to publish; (4) lack of staff training. Strategies to address these included training research personnel and improved communication with site staff and patients regarding the value of PROs. Examples of good practice were identified. Conclusion: Misconceptions relating to PRO methodology and its use may undermine their planning, collection, and reporting. There is a role for funding, regulatory, methodological, and journalistic institutions to address perceptions around the value of PROs, their position within the trial outcomes hierarchy, that PRO training and guidance is available, signposted, and readily accessible, with accompanying measures to ensure compliance with international best practice guidelines

International perspectives on suboptimal patient-reported outcome trial design and reporting in cancer clinical trials: A qualitative study

Abstract Purpose: Evidence suggests that the patient- reported outcome (PRO) content of cancer trial protocols is frequently inadequate and non- reporting of PRO findings is widespread. This qualitative study examined the factors influencing suboptimal PRO protocol content, implementation, and reporting, and use of PRO data during clinical interactions. Methods: Semi- structured interviews were conducted with four stakeholder groups: (1) trialists and chief investigators; (2) people with lived experience of cancer; (3) international experts in PRO cancer trial design; (4) journal editors, funding panelists, and regulatory agencies. Data were analyzed using directed thematic analysis with an iterative coding frame. Results: Forty- four interviews were undertaken. Several factors were identified that could influenced effective integration of PROs into trials and subsequent findings. Participants described (1) late inclusion of PROs in trial design; (2) PROs being considered a lower priority outcome compared to survival; (3) trialists’ reluctance to collect or report PROs due to participant burden, missing data, and perceived reticence of journals to publish; (4) lack of staff training. Strategies to address these included training research personnel and improved communication with site staff and patients regarding the value of PROs. Examples of good practice were identified. Conclusion: Misconceptions relating to PRO methodology and its use may under-mine their planning, collection, and reporting. There is a role for funding, regulatory, methodological, and journalistic institutions to address perceptions around the value of PROs, their position within the trial outcomes hierarchy, that PRO training and guidance is available, signposted, and readily accessible, with accompanying measures to ensure compliance with international best practice guideline

Systematic Evaluation of Patient-Reported Outcome Protocol Content and Reporting in Cancer Trials

Background: Patient-reported outcomes (PROs) are captured within cancer trials to help future patients and their clinicians make more informed treatment decisions. However, variability in standards of PRO trial design and reporting threaten the validity of these endpoints for application in clinical practice. Methods: We systematically investigated a cohort of randomized controlled cancer trials that included a primary or secondary PRO. For each trial, an evaluation of protocol and reporting quality was undertaken using standard checklists. General patterns of reporting where also explored. Results: Protocols (101 sourced, 44.3%) included a mean (SD) of 10 (4) of 33 (range = 2–19) PRO protocol checklist items. Recommended items frequently omitted included the rationale and objectives underpinning PRO collection and approaches to minimize/address missing PRO data. Of 160 trials with published results, 61 (38.1%, 95% confidence interval = 30.6% to 45.7%) failed to include their PRO findings in any publication (mean 6.43-year follow-up); these trials included 49 568 participants. Although two-thirds of included trials published PRO findings, reporting standards were often inadequate according to international guidelines (mean [SD] inclusion of 3 [3] of 14 [range = 0–11]) CONSORT PRO Extension checklist items). More than one-half of trials publishing PRO results in a secondary publication (12 of 22, 54.5%) took 4 or more years to do so following trial closure, with eight (36.4%) taking 5–8 years and one trial publishing after 14 years. Conclusions: PRO protocol content is frequently inadequate, and nonreporting of PRO findings is widespread, meaning patient-important information may not be available to benefit patients, clinicians, and regulators. Even where PRO data are published, there is often considerable delay and reporting quality is suboptimal. This study presents key recommendations to enhance the likelihood of successful delivery of PROs in the future

Dynamic Regulation of Myosin Light Chain Phosphorylation by Rho-kinase

Myosin light chain (MLC) phosphorylation plays important roles in various cellular functions such as cellular morphogenesis, motility, and smooth muscle contraction. MLC phosphorylation is determined by the balance between activities of Rho-associated kinase (Rho-kinase) and myosin phosphatase. An impaired balance between Rho-kinase and myosin phosphatase activities induces the abnormal sustained phosphorylation of MLC, which contributes to the pathogenesis of certain vascular diseases, such as vasospasm and hypertension. However, the dynamic principle of the system underlying the regulation of MLC phosphorylation remains to be clarified. Here, to elucidate this dynamic principle whereby Rho-kinase regulates MLC phosphorylation, we developed a mathematical model based on the behavior of thrombin-dependent MLC phosphorylation, which is regulated by the Rho-kinase signaling network. Through analyzing our mathematical model, we predict that MLC phosphorylation and myosin phosphatase activity exhibit bistability, and that a novel signaling pathway leading to the auto-activation of myosin phosphatase is required for the regulatory system of MLC phosphorylation. In addition, on the basis of experimental data, we propose that the auto-activation pathway of myosin phosphatase occurs in vivo. These results indicate that bistability of myosin phosphatase activity is responsible for the bistability of MLC phosphorylation, and the sustained phosphorylation of MLC is attributed to this feature of bistability

A structural comparison of human serum transferrin and human lactoferrin

The transferrins are a family of proteins that bind free iron in the blood and bodily fluids. Serum transferrins function to deliver iron to cells via a receptor-mediated endocytotic process as well as to remove toxic free iron from the blood and to provide an anti-bacterial, low-iron environment. Lactoferrins (found in bodily secretions such as milk) are only known to have an anti-bacterial function, via their ability to tightly bind free iron even at low pH, and have no known transport function. Though these proteins keep the level of free iron low, pathogenic bacteria are able to thrive by obtaining iron from their host via expression of outer membrane proteins that can bind to and remove iron from host proteins, including both serum transferrin and lactoferrin. Furthermore, even though human serum transferrin and lactoferrin are quite similar in sequence and structure, and coordinate iron in the same manner, they differ in their affinities for iron as well as their receptor binding properties: the human transferrin receptor only binds serum transferrin, and two distinct bacterial transport systems are used to capture iron from serum transferrin and lactoferrin. Comparison of the recently solved crystal structure of iron-free human serum transferrin to that of human lactoferrin provides insight into these differences

Molecular correlates of host specialization in Staphylococcus aureus

The majority of Staphylococcus aureus isolates that are recovered from either serious infections in humans or from mastitis in cattle represent genetically distinct sets of clonal groups. Moreover, population genetic analyses have provided strong evidence of host specialization among S. aureus clonal groups associated with human and ruminant infection. However, the molecular basis of host specialization in S. aureus is not understood.We sequenced the genome of strain ET3-1, a representative isolate of a common bovine mastitis-causing S. aureus clone. Strain ET3-1 encodes several genomic elements that have not been previously identified in S. aureus, including homologs of virulence factors from other gram-positive pathogens. Relative to the other sequenced S. aureus associated with human infection, allelic variation in ET3-1 was high among virulence and surface-associated genes involved in host colonization, toxin production, iron metabolism, antibiotic resistance, and gene regulation. Interestingly, a number of well-characterized S. aureus virulence factors, including protein A and clumping factor A, exist as pseudogenes in ET3-1. Whole-genome DNA microarray hybridization revealed considerable similarity in the gene content of highly successful S. aureus clones associated with bovine mastitis, but not among those clones that are only infrequently recovered from bovine hosts.Whole genome sequencing and comparative genomic analyses revealed a set of molecular genetic features that distinguish clones of highly successful bovine-associated S. aureus optimized for mastitis pathogenesis in cattle from those that infect human hosts or are only infrequently recovered from bovine sources. Further, the results suggest that modern bovine specialist clones diverged from a common ancestor resembling human-associated S. aureus clones through a combination of foreign DNA acquisition and gene decay