Background
The most frequently reported treatment‐related adverse event in clinical trials with the cyclin‐dependent kinase 4/6 (CDK4/6) inhibitor palbociclib is neutropenia. Allelic variants in ...ABCB1 and ERCC1 might be associated with early occurrence (i.e., end of week 2 treatment) of grade 3/4 neutropenia. Pharmacogenetic analyses were performed to uncover associations between single nucleotide polymorphisms (SNPs) in these genes, patient baseline characteristics, and early occurrence of grade 3/4 neutropenia.
Materials and Methods
ABCB1 (rs1045642, rs1128503) and ERCC1 (rs3212986, rs11615) were analyzed in germline DNA from palbociclib‐treated patients from PALOMA‐2 (n = 584) and PALOMA‐3 (n = 442). SNP, race, and cycle 1 day 15 (C1D15) absolute neutrophil count (ANC) data were available for 652 patients. Univariate and multivariable analyses evaluated associations between SNPs, patient baseline characteristics, and early occurrence of grade 3/4 neutropenia. Analyses were stratified by Asian (n = 122) and non‐Asian (n = 530) ethnicity. Median progression‐free survival (mPFS) was estimated using the Kaplan‐Meier method. The effect of genetic variants on palbociclib pharmacokinetics was analyzed.
Results
ABCB1 and ERCC1_rs11615 SNP frequencies differed between Asian and non‐Asian patients. Multivariable analysis showed that low baseline ANC was a strong independent risk factor for C1D15 grade 3/4 neutropenia regardless of race (Asians: odds ratio OR, 6.033, 95% confidence interval CI, 2.615−13.922, p < .0001; Non‐Asians: OR, 6.884, 95% CI, 4.138−11.451, p < .0001). ABCB1_rs1128503 (C/C vs. T/T: OR, 0.57, 95% CI, 0.311−1.047, p = .070) and ERCC1_rs11615 (A/A vs. G/G: OR, 1.75, 95% CI, 0.901−3.397, p = .098) were potential independent risk factors for C1D15 grade 3/4 neutropenia in non‐Asian patients. Palbociclib mPFS was consistent across genetic variants; exposure was not associated with ABCB1 genotype.
Conclusion
This is the first comprehensive assessment of pharmacogenetic data in relationship to exposure to a CDK4/6 inhibitor. Pharmacogenetic testing may inform about potentially increased likelihood of patients developing severe neutropenia (NCT01740427, NCT01942135).
Implications for Practice
Palbociclib plus endocrine therapy improves hormone receptor–positive/human epidermal growth factor receptor 2–negative advanced breast cancer outcomes, but is commonly associated with neutropenia. Genetic variants in ABCB1 may influence palbociclib exposure, and in ERCC1 are associated with chemotherapy‐induced severe neutropenia. Here, the associations of single nucleotide polymorphisms in these genes and baseline characteristics with neutropenia were assessed. Low baseline absolute neutrophil count was a strong risk factor (p < .0001) for grade 3/4 neutropenia. There was a trend indicating that ABCB1_rs1128503 and ERCC1_rs11615 were potential risk factors (p < .10) for grade 3/4 neutropenia in non‐Asian patients. Pharmacogenetic testing could inform clinicians about the likelihood of severe neutropenia with palbociclib.
The most frequently reported treatment‐related adverse event in clinical trials with the cyclin‐dependent kinase 4/6 (CDK4/6) inhibitor palbociclib is neutropenia. In this study, pharmacogenetic analyses were performed to uncover associations between single nucleotide polymorphisms in the ABCB1 and ERCC1 genes, patient baseline characteristics, and early occurrence of grade 3/4 neutropenia.
Stressful environments often lead to protein unfolding and the formation of cytotoxic aggregates that can compromise cell survival. The molecular chaperone heat shock protein (HSP) 101 is a protein ...disaggregase that co-operates with the small HSP (sHSP) and HSP70 chaperones to facilitate removal of such aggregates and is essential for surviving severe heat stress. To better define how HSP101 protects plants, we investigated the localization and targets of this chaperone in Arabidopsis (Arabidopsis thaliana). By following HSP101 tagged with GFP, we discovered that its intracellular distribution is highly dynamic and includes a robust, reversible sequestration into cytoplasmic foci that vary in number and size among cell types and are potentially enriched in aggregated proteins. Affinity isolation of HSP101 recovered multiple proteasome subunits, suggesting a functional interaction. Consistent with this, the GFP-tagged 26S proteasome regulatory particle non-ATPase (RPN) 1a transiently colocalized with HSP101 in cytoplasmic foci during recovery. In addition, analysis of aggregated (insoluble) proteins showed they are extensively ubiquitylated during heat stress, especially in plants deficient in HSP101 or class I sHSPs, implying that protein disaggregation is important for optimal proteasomal degradation. Many potential HSP101 clients, identified by mass spectrometry of insoluble proteins, overlapped with known stress granule constituents and sHSP-interacting proteins, confirming a role for HSP101 in stress granule function. Connections between HSP101, stress granules, proteasomes, and ubiquitylation imply that dynamic coordination between protein disaggregation and proteolysis is required to survive proteotoxic stress caused by protein aggregation at high temperatures.
26S proteasome abundance is tightly regulated at multiple levels, including the elimination of excess or inactive particles by autophagy. In yeast, this proteaphagy occurs upon nitrogen starvation ...but not carbon starvation, which instead stimulates the rapid sequestration of proteasomes into cytoplasmic puncta termed proteasome storage granules (PSGs). Here, we show that PSGs help protect proteasomes from autophagic degradation. Both the core protease and regulatory particle sub-complexes are sequestered separately into PSGs via pathways dependent on the accessory proteins Blm10 and Spg5, respectively. Modulating PSG formation, either by perturbing cellular energy status or pH, or by genetically eliminating factors required for granule assembly, not only influences the rate of proteasome degradation, but also impacts cell viability upon recovery from carbon starvation. PSG formation and concomitant protection against proteaphagy also occurs in
Arabidopsis
, suggesting that PSGs represent an evolutionarily conserved cache of proteasomes that can be rapidly re-mobilized based on energy availability.
Proteins perform many jobs within an organism, including providing structure and support, and protecting against infection. The levels of the many proteins in a cell need to be carefully controlled so that the correct amounts are present at the right place and time to perform these tasks. This control can be achieved by balancing the production of new proteins with the break down (or degradation) of proteins that are no longer required or become dysfunctional.
Most cells have two pathways for degrading proteins. One pathway breaks down individual proteins specifically marked for elimination; this causes them to be recognized by a structure called the proteasome, which chops proteins into smaller pieces. Larger protein assemblies – including the proteasome itself – are to big for the proteasome and thus need to be degraded by another pathway called autophagy. This process engulfs and delivers parts of a cell to a membrane-bound compartment called the vacuole, which ‘digests’ and recycles these larger constituents.
Proteasomes are degraded by autophagy when they are not working correctly and when nitrogen (a crucial nutrient) is in short supply. However, proteasomes are not degraded when cells lack carbon, even though this starvation is known to activate autophagy in the same way that an absence of nitrogen does. So how do proteasomes escape degradation when cells are starved for carbon?
Marshall and Vierstra now show that upon carbon starvation, proteasomes rapidly exit the cell nucleus and cluster together in the main part of the cell (termed the cytosol). These clusters are known as proteasome storage granules (PSGs). In fungi and plants, mutations or conditions inside the cell that make it difficult for PSGs to assemble cause proteasomes to instead be broken down in the vacuole when carbon availability is low. Clustering into PSGs therefore protects proteasomes from autophagy. This clustering appears advantageous to cells; yeast cells that could form PSGs were better able to start growing again when their nutrient supply improved.
Protein clustering (also known as aggregation) is an important strategy that cells use to survive stressful conditions. However, it can also be harmful when proteins aggregate inappropriately, such as occurs in Alzheimer’s disease. Researchers may be able to use PSG assembly as a convenient model to study the causes and consequences of protein aggregation; this knowledge could ultimately be applied to improve human health and crop productivity.
The Society of Thoracic Surgeons (STS) National Database is the foundation for most of the Society's quality, research, and patient safety activities. Beginning in January 2016 and repeating each ...year, The Annals of Thoracic Surgery will publish a monthly Database series of scholarly articles on outcomes analysis, quality improvement, and patient safety. Six articles will be directly derived from the STS National Database and will be published every other month: three articles on outcomes and quality (one each from the STS Adult Cardiac Surgery Database, the STS Congenital Heart Surgery Database, and the STS General Thoracic Surgery Database), and three articles on research (one from each of these three specialty databases). These six articles will alternate with five additional articles on topics related to patient safety. The final article, to be published in December, will provide a summary of the prior 11 manuscripts. This series will allow STS and its Workforces on National Databases, Research Development, and Patient Safety to convey timely information aimed at improving the quality and safety of cardiothoracic surgery.
Woody plants vary in their adaptations to drought and shade. For a better prediction of vegetation responses to drought and shade within dynamic global vegetation models, it is critical to group ...species into functional types with similar adaptations. One of the key challenges is that the adaptations are generally determined by a large number of plant traits that may not be available for a large number of species. In this study, we present two heuristic woody plant groups that were separated using cluster analysis in a three-dimensional trait-environment space based on three key metrics for each species: mean xylem embolism resistance, shade tolerance and habitat aridity. The two heuristic groups separate these species into tolerators and avoiders. The tolerators either rely on their high embolism resistance to tolerate drought in arid habitats (e.g., Juniperus and Prunus) or rely on high shade tolerance to withstand shaded conditions in wet habitats (e.g., Picea, Abies and Acer). In contrast, all avoiders have low embolism resistance and low shade tolerance. In arid habitats, avoiders tend to minimize catastrophic embolism (e.g., most Pinus species) while in wet habitats, they may survive despite low shade tolerance (e.g., Betula, Populus, Alnus and Salix). Because our approach links traits to the environmental conditions, we expect it could be a promising framework for predicting changes in species composition, and therefore ecosystem function, under changing environmental conditions.
The 26S proteasome is a highly dynamic, multisubunit, ATP-dependent protease that plays a central role in cellular housekeeping and many aspects of plant growth and development by degrading aberrant ...polypeptides and key cellular regulators that are first modified by ubiquitin. Although the 26S proteasome was originally enriched from plants over 30 years ago, only recently have significant advances been made in our ability to isolate and study the plant particle. Here, we describe two robust methods for purifying the 26S proteasome and its subcomplexes from Arabidopsis thaliana; one that involves conventional chromatography techniques to isolate the complex from wild-type plants, and another that employs the genetic replacement of individual subunits with epitope-tagged variants combined with affinity purification. In addition to these purification protocols, we describe methods commonly used to analyze the activity and composition of the complex.
The adverse effects of stress on brain and behavior have long been known and well-studied, with abundant evidence linking stress to, among other things, mood and anxiety disorders. Likewise, many ...have investigated potential treatments for stress-related mood and anxiety phenotypes and demonstrated good response to standard antidepressant medications like selective serotonin reuptake inhibitors (SSRIs), as well as environmental manipulations like exercise or enrichment. However, the extent to which stress and various treatments act on overlapping pathways in the brain is less well understood. Here, we used a widely studied social defeat stress paradigm to induce a robust depression- and anxiety-like phenotype and chronic corticosterone elevation that persisted for at least 4 weeks in wild type male mice. When mice were treated with either the SSRI fluoxetine or an enriched environment, both led to similar behavioral recovery from social defeat. We then focused on the amygdala and assessed the effects of social defeat, fluoxetine, and enrichment on 168 genes broadly related to synaptic plasticity or oxidative stress. We found 24 differentially expressed genes in response to social defeat stress. Interestingly, fluoxetine led to broad normalization of the stress-induced expression pattern while enrichment led to expression changes in a separate set of genes. Together, this study provides additional insight into the chronic effects of social defeat stress on behavior and gene expression in the amygdala. The findings also suggest that, for a subset of genes assessed, fluoxetine and environmental enrichment have strikingly divergent effects on expression in the amygdala, despite leading to similar behavioral outcomes.
•Environmental enrichment and fluoxetine result in similar recovery from stress-induced depression and anxiety-like behavior.•In the amygdala, stress-related gene expression changes are broadly normalized by fluoxetine but not environmental enrichment.•Environmental enrichment and fluoxetine lead to distinct sets of non-overlapping gene expression changes in the amygdala.•Gene expression patterns may offer insights into complex mechanisms of stress-related psychiatric disorders and treatment.
The MultiCode-PLx system (EraGen Biosciences, Inc., Madison, WI) for the detection of respiratory viruses uses an expanded genetic alphabet, multiplex PCR chemistry, and microsphere flow cytometry to ...rapidly detect and specifically identify 17 different respiratory viruses directly in clinical specimens. The MultiCode-PLx system was tested in parallel with direct fluorescent-antibody (DFA) staining and rapid shell vial culture (R-mix cells; Diagnostic Hybrids, Inc. Athens, OH) with 354 respiratory specimens from adult patients that were submitted to the clinical virology laboratory at the Emory University Hospital. Single-target PCRs were performed with retained samples to confirm the positive results obtained with the MultiCode-PLx system for viruses not covered by DFA and R-mix culture (metapneumovirus, coronaviruses CoV, parainfluenza viruses 4a and 4b, and rhinoviruses) and to resolve any discrepancies between the DFA and R-mix culture and the MultiCode-PLx results for viruses common to both systems. Respiratory viruses were detected in 77 (21.8%) and 116 (32.7%) specimens by DFA and R-mix culture and with the MultiCode-PLx system, respectively. Among the viruses common to both systems, the MultiCode-PLx system detected significantly more influenza A viruses (P = 0.0026). An additional increased diagnostic yield with the MultiCode-PLx system resulted from the detection of human metapneumovirus (HMPV) in 9 specimens, human CoV (HCoV) in 3 specimens, and human rhinovirus (HRV) in 16 specimens. Also, two mixed viral infections were detected by the MultiCode-PLx system (HCoV OC43 and HRV infections and HMPV and HRV infections), but none were detected by DFA and R-mix culture. Single-target PCRs verified the results obtained with the MultiCode-PLx system for 73 of 81 (90.1%) specimens that had discordant results or that were not covered by DFA and R-mix culture. The MultiCode-PLx system provides clinical laboratories with a practical, rapid, and sensitive means for the massively multiplexed molecular detection of common respiratory viruses.
Background
Hospital pharmacy audit and feedback of ‘do not use’ medication abbreviations improves patient safety. For audit and feedback systems to be effective, the data captured must be of high ...quality such that end-users trust the information to guide practice change. The quality of data captured during monthly standardized pharmacy ‘do not use’ abbreviation audits is currently unknown.
Objective
We aimed to assess pharmacy ‘do not use’ abbreviation audit data quality.
Method
Primary audit data quality was assessed by examining a random sample of handwritten medication prescriptions for the presence and type of ‘do not use’ abbreviations. This data was compared with the pharmacy monthly audit data to determine data capture agreement and consistency over time.
Results
There were 1132 prescriptions from July, October, and December 2019 included. Data capture agreement between the pharmacy audit and the secondary assessment using Cohen’s Kappa ranged from 0.53 to 0.63. The primary audit under-reported ‘do not use’ abbreviation rates, however this did not vary over time (χ2 = 1.215,
p
= 0.545).
Conclusion
Pharmacy staff audits under-reported ‘do not use’ abbreviation rates, however this was consistent over time. The quality of pharmacy audits should be assessed and disseminated to end-users prior to implementing feedback.
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