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1.
Andrology ; 2024 Apr 04.
Article in English | MEDLINE | ID: mdl-38576152

ABSTRACT

BACKGROUND: The epididymis has long been of interest owing to its role in promoting the functional maturation of the male germline. More recent evidence has also implicated the epididymis as an important sensory tissue responsible for remodeling of the sperm epigenome, both under physiological conditions and in response to diverse forms of environmental stress. Despite this knowledge, the intricacies of the molecular pathways involved in regulating the adaptation of epididymal tissue to paternal stressors remains to be fully resolved. OBJECTIVE: The overall objective of this study was to investigate the direct impact of corticosterone challenge on a tractable epididymal epithelial cell line (i.e., mECap18 cells), in terms of driving adaptation of the cellular proteome and phosphoproteome signaling networks. MATERIALS AND METHODS: The newly developed phosphoproteomic platform EasyPhos coupled with sequencing via an Orbitrap Exploris 480 mass spectrometer, was applied to survey global changes in the mECap18 cell (phospho)proteome resulting from sub-chronic (10-day) corticosterone challenge. RESULTS: The imposed corticosterone exposure regimen elicited relatively subtle modifications of the global mECap18 proteome (i.e., only 73 out of 4171 [∼1.8%] proteins displayed altered abundance). By contrast, ∼15% of the mECap18 phosphoproteome was substantially altered following corticosterone challenge. In silico analysis of the corresponding parent proteins revealed an activation of pathways linked to DNA damage repair and oxidative stress responses as well as a reciprocal inhibition of pathways associated with organismal death. Corticosterone challenge also induced the phosphorylation of several proteins linked to the biogenesis of microRNAs. Accordingly, orthogonal validation strategies confirmed an increase in DNA damage, which was ameliorated upon selective kinase inhibition, and an altered abundance profile of a subset of microRNAs in corticosterone-treated cells. CONCLUSIONS: Together, these data confirm that epididymal epithelial cells are reactive to corticosterone challenge, and that their response is tightly coupled to the opposing action of cellular kinases and phosphatases.

3.
Proteomics ; 24(9): e2300309, 2024 May.
Article in English | MEDLINE | ID: mdl-38334196

ABSTRACT

The CD117 mast/stem cell growth factor receptor tyrosine kinase (KIT) is critical for haematopoiesis, melanogenesis and stem cell maintenance. KIT is commonly activated by mutation in cancers including acute myeloid leukaemia, melanoma and gastrointestinal stromal tumours (GISTs). The kinase and the juxtamembrane domains of KIT are mutation hotspots; with the kinase domain mutation D816V common in leukaemia and the juxtamembrane domain mutation V560G common in GISTs. Given the importance of mutant KIT signalling in cancer, we have conducted a proteomic and phosphoproteomic analysis of myeloid progenitor cells expressing D816V- and V560G-KIT mutants, using an FDCP1 isogenic cell line model. Proteomic analysis revealed increased abundance of proteases and growth signalling proteins in KIT-mutant cells compared to empty vector (EV) controls. Pathway analysis identified increased oxidative phosphorylation in D816V- and V560G-mutant KIT cells, which was targetable using the inhibitor IACS010759. Dysregulation of RNA metabolism and cytoskeleton/adhesion pathways was identified in both the proteome and phosphoproteome of KIT-mutant cells. Phosphoproteome analysis further revealed active kinases such as EGFR, ERK and PKC, which were targetable using pharmacological inhibitors. This study provides a pharmaco-phosphoproteomic profile of D816V- and V560G-mutant KIT cells, which reveals novel therapeutic strategies that may be applicable to a range of cancers.


Subject(s)
Mutation , Proteomics , Proto-Oncogene Proteins c-kit , Proto-Oncogene Proteins c-kit/genetics , Proto-Oncogene Proteins c-kit/metabolism , Humans , Proteomics/methods , Cell Line, Tumor , Neoplasms/genetics , Neoplasms/metabolism , Neoplasms/pathology , Phosphoproteins/genetics , Phosphoproteins/metabolism , Signal Transduction/genetics , Phosphorylation , Proteome/genetics , Proteome/metabolism , Proteome/analysis
4.
J Clin Invest ; 134(6)2024 Feb 06.
Article in English | MEDLINE | ID: mdl-38319732

ABSTRACT

Diffuse midline glioma (DMG), including tumors diagnosed in the brainstem (diffuse intrinsic pontine glioma; DIPG), are uniformly fatal brain tumors that lack effective treatment. Analysis of CRISPR/Cas9 loss-of-function gene deletion screens identified PIK3CA and MTOR as targetable molecular dependencies across patient derived models of DIPG, highlighting the therapeutic potential of the blood-brain barrier-penetrant PI3K/Akt/mTOR inhibitor, paxalisib. At the human-equivalent maximum tolerated dose, mice treated with paxalisib experienced systemic glucose feedback and increased insulin levels commensurate with patients using PI3K inhibitors. To exploit genetic dependence and overcome resistance while maintaining compliance and therapeutic benefit, we combined paxalisib with the antihyperglycemic drug metformin. Metformin restored glucose homeostasis and decreased phosphorylation of the insulin receptor in vivo, a common mechanism of PI3K-inhibitor resistance, extending survival of orthotopic models. DIPG models treated with paxalisib increased calcium-activated PKC signaling. The brain penetrant PKC inhibitor enzastaurin, in combination with paxalisib, synergistically extended the survival of multiple orthotopic patient-derived and immunocompetent syngeneic allograft models; benefits potentiated in combination with metformin and standard-of-care radiotherapy. Therapeutic adaptation was assessed using spatial transcriptomics and ATAC-Seq, identifying changes in myelination and tumor immune microenvironment crosstalk. Collectively, this study has identified what we believe to be a clinically relevant DIPG therapeutic combinational strategy.


Subject(s)
Brain Stem Neoplasms , Diffuse Intrinsic Pontine Glioma , Glioma , Metformin , Humans , Mice , Animals , Diffuse Intrinsic Pontine Glioma/drug therapy , Diffuse Intrinsic Pontine Glioma/genetics , Phosphatidylinositol 3-Kinases/genetics , Brain Stem Neoplasms/drug therapy , Brain Stem Neoplasms/genetics , Glioma/drug therapy , Glioma/genetics , Glioma/pathology , TOR Serine-Threonine Kinases/genetics , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/therapeutic use , Phosphoinositide-3 Kinase Inhibitors/therapeutic use , Glucose , Metformin/pharmacology , Tumor Microenvironment
5.
Proteomics ; 24(7): e2300267, 2024 Apr.
Article in English | MEDLINE | ID: mdl-37849217

ABSTRACT

Fibroblasts are the most common cell type in stroma and function in the support and repair of most tissues. Mouse embryonic fibroblasts (MEFs) are amenable to isolation and rapid growth in culture. MEFs are therefore widely used as a standard model for functional characterisation of gene knockouts, and can also be used in co-cultures, commonly to support embryonic stem cell cultures. To facilitate their use as a research tool, we have performed a comprehensive proteomic and phosphoproteomic characterisation of wild-type primary MEFs from C57BL/6 mice. EIF2/4 and MTOR signalling pathways were abundant in both the proteome and phosphoproteome, along with extracellular matrix (ECM) and cytoskeleton associated pathways. Consistent with this, kinase enrichment analysis identified activation of P38A, P90RSK, P70S6K, and MTOR. Cell surface markers and matrisome proteins were also annotated. Data are available via ProteomeXchange with identifier PXD043244. This provides a comprehensive catalogue of the wild-type MEF proteome and phosphoproteome which can be utilised by the field to guide future work.


Subject(s)
Proteome , Proteomics , Animals , Mice , Proteome/analysis , Fibroblasts/metabolism , Mice, Inbred C57BL , TOR Serine-Threonine Kinases/metabolism
6.
Proteomics ; 24(7): e2300253, 2024 Apr.
Article in English | MEDLINE | ID: mdl-37759396

ABSTRACT

Residing between the testes and the vas deferens, the epididymis is a highly convoluted tubule whose unique luminal microenvironment is crucial for the functional maturation of spermatozoa. This microenvironment is created by the combined secretory and resorptive activity of the lining epididymal epithelium, including the release of extracellular vesicles (epididymosomes), which encapsulate fertility modulating proteins and a myriad of small non-coding RNAs (sncRNAs) that are destined for delivery to recipient sperm cells. To enable investigation of this intercellular communication nexus, we have previously developed an immortalized mouse caput epididymal epithelial cell line (mECap18). Here, we describe the application of label-free mass spectrometry to characterize the mECap18 cell proteome and compare this to the proteome of native mouse caput epididymal epithelial cells. We report the identification of 5,313 mECap18 proteins, as many as 75.8% of which were also identified in caput epithelial cells wherein they mapped to broadly similar protein classification groupings. Furthermore, key pathways associated with protein synthesis (e.g., EIF2 signaling) and cellular protection in the male reproductive tract (e.g., sirtuin signaling) were enriched in both proteomes. This comparison supports the utility of the mECap18 cell line as a tractable in-vitro model for studying caput epididymal epithelial cell function.


Subject(s)
Epididymis , Proteome , Male , Animals , Mice , Epididymis/metabolism , Proteome/metabolism , Semen , Testis/metabolism , Spermatozoa/metabolism
7.
CJEM ; 25(7): 568-579, 2023 07.
Article in English | MEDLINE | ID: mdl-37378871

ABSTRACT

OBJECTIVE: The purpose of this study was to identify the learning needs of emergency physicians returning to Emergency Medicine (EM) practice after clinical leaves of less than 2 years, summarize existing return to practice programs, and propose recommendations regarding ideal educational and support structures for these physicians both during their practice gaps and upon return to EM. METHODS: A multiple-phased study was conducted to establish recommendations regarding ideal educational and support structures for emergency physicians returning from practice gaps of less than 2 years. The overall design involved an initial environmental scan of existing and exemplar programs and regulatory body positions, followed by interviews with EM Department Heads from across Canada, and then subsequent content analysis and recommendation derivation by EM medical education expert group consensus. These summary recommendations were further revised by consensus at the 2022 CAEP conference academic symposium to derive a final set of consensus recommendations. CONCLUSIONS: We have developed a set of recommendations regarding ideal educational and support structures for physicians experiencing gaps in practice of less than 2 years. This set of recommendations was informed by review of existing and exemplar programs, policies and experience of regulatory bodies, interviews with EM Department Heads across Canada, and a subsequent process of consensus at the 2022 CAEP conference academic symposium. It is hoped that this set of recommendations will inform discussions and potential strategies employed by departments to facilitate the smooth and effective return to EM practice for individuals experiencing gaps.


ABSTRAIT: OBJECTIFS: Le but de cette étude était de déterminer les besoins d'apprentissage des médecins d'urgence qui retournent à la pratique de la médecine d'urgence (ME) après des congés cliniques de moins de deux ans, de résumer les programmes de retour à la pratique existants. et de proposer des recommandations concernant les structures de formation et de soutien idéales pour ces médecins, à la fois pendant leurs lacunes dans la pratique et à leur retour à la GU. MéTHODES: Une étude en plusieurs phases a été menée afin d'établir des recommandations concernant les structures de formation et de soutien idéales pour les médecins d'urgence qui reviennent de lacunes de moins de deux ans. La conception globale comprenait une première analyse de l'environnement des programmes existants et exemplaires et des postes d'organismes de réglementation, suivie d'entrevues avec les chefs des services de GU de partout au Canada. et ensuite l'analyse du contenu et la formulation de recommandations par consensus du groupe d'experts en éducation médicale de la SE. Ces recommandations résumées ont été révisées par consensus lors du symposium universitaire de la conférence 2022 de l'ACMU afin d'en arriver à une série finale de recommandations consensuelles. CONCLUSION: Nous avons élaboré une série de recommandations concernant les structures de formation et de soutien idéales pour les médecins qui connaissent des lacunes dans la pratique depuis moins de deux ans. Cette série de recommandations a été éclairée par l'examen des programmes, des politiques et de l'expérience des organismes de réglementation existants et exemplaires, des entrevues avec les chefs des services de GU partout au Canada et un processus subséquent de consensus au symposium universitaire de la conférence 2022 de la CAEP. On espère que cette série de recommandations éclairera les discussions et les stratégies potentielles employées par les ministères pour faciliter le retour en douceur et efficace à la pratique de GU pour les personnes qui connaissent des lacunes.


Subject(s)
Emergency Medicine , Physicians , Humans , Consensus , Societies, Medical , Emergency Medicine/education , Canada
9.
J Am Heart Assoc ; 12(8): e026681, 2023 04 18.
Article in English | MEDLINE | ID: mdl-37026540

ABSTRACT

Background For patients with atrial fibrillation seen in the emergency department (ED) following a transient ischemic attack (TIA) or minor stroke, the impact of initiating oral anticoagulation immediately rather than deferring the decision to outpatient follow-up is unknown. Methods and Results We conducted a planned secondary data analysis of a prospective cohort of 11 507 adults in 13 Canadian EDs between 2006 and 2018. Patients were eligible if they were aged 18 years or older, with a final diagnosis of TIA or minor stroke with previously documented or newly diagnosed atrial fibrillation. The primary outcome was subsequent stroke, recurrent TIA, or all-cause mortality within 90 days of the index TIA diagnosis. Secondary outcomes included stroke, recurrent TIA, or death and rates of major bleeding. Of 11 507 subjects with TIA/minor stroke, atrial fibrillation was identified in 11.2% (1286, mean age, 77.3 [SD 11.1] years, 52.4% male). Over half (699; 54.4%) were already taking anticoagulation, 89 (6.9%) were newly prescribed anticoagulation in the ED. By 90 days, 4.0% of the atrial fibrillation cohort had experienced a subsequent stroke, 6.5% subsequent TIA, and 2.6% died. Results of a multivariable logistic regression indicate no association between prescribed anticoagulation in the ED and these 90-day outcomes (composite odds ratio, 1.37 [95% CI, 0.74-2.52]). Major bleeding was found in 5 patients, none of whom were in the ED-initiated anticoagulation group. Conclusions Initiating oral anticoagulation in the ED following new TIA was not associated with lower recurrence rates of neurovascular events or all-cause mortality in patients with atrial fibrillation.


Subject(s)
Atrial Fibrillation , Ischemic Attack, Transient , Stroke , Humans , Male , Aged , Female , Ischemic Attack, Transient/drug therapy , Ischemic Attack, Transient/epidemiology , Ischemic Attack, Transient/prevention & control , Atrial Fibrillation/complications , Atrial Fibrillation/diagnosis , Atrial Fibrillation/drug therapy , Prospective Studies , Canada/epidemiology , Neoplasm Recurrence, Local/complications , Stroke/epidemiology , Stroke/etiology , Stroke/prevention & control , Hemorrhage/chemically induced , Hemorrhage/epidemiology , Anticoagulants/adverse effects , Risk Factors
10.
Sci Signal ; 16(778): eabp9586, 2023 03 28.
Article in English | MEDLINE | ID: mdl-36976863

ABSTRACT

Mutations in the type III receptor tyrosine kinase FLT3 are frequent in patients with acute myeloid leukemia (AML) and are associated with a poor prognosis. AML is characterized by the overproduction of reactive oxygen species (ROS), which can induce cysteine oxidation in redox-sensitive signaling proteins. Here, we sought to characterize the specific pathways affected by ROS in AML by assessing oncogenic signaling in primary AML samples. The oxidation or phosphorylation of signaling proteins that mediate growth and proliferation was increased in samples from patient subtypes with FLT3 mutations. These samples also showed increases in the oxidation of proteins in the ROS-producing Rac/NADPH oxidase-2 (NOX2) complex. Inhibition of NOX2 increased the apoptosis of FLT3-mutant AML cells in response to FLT3 inhibitors. NOX2 inhibition also reduced the phosphorylation and cysteine oxidation of FLT3 in patient-derived xenograft mouse models, suggesting that decreased oxidative stress reduces the oncogenic signaling of FLT3. In mice grafted with FLT3 mutant AML cells, treatment with a NOX2 inhibitor reduced the number of circulating cancer cells, and combining FLT3 and NOX2 inhibitors increased survival to a greater extent than either treatment alone. Together, these data raise the possibility that combining NOX2 and FLT3 inhibitors could improve the treatment of FLT3 mutant AML.


Subject(s)
Cysteine , Leukemia, Myeloid, Acute , Humans , Animals , Mice , Reactive Oxygen Species/metabolism , Cysteine/genetics , Leukemia, Myeloid, Acute/drug therapy , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/metabolism , Mutation , Protein Kinase Inhibitors/pharmacology , Disease Models, Animal , Cell Line, Tumor , fms-Like Tyrosine Kinase 3/genetics
11.
Stroke ; 54(4): 1030-1036, 2023 04.
Article in English | MEDLINE | ID: mdl-36779338

ABSTRACT

BACKGROUND: Computed tomography (CT) findings of acute and chronic ischemia are associated with subsequent stroke risk in patients with transient ischemic attack. We sought to validate these associations in a large prospective cohort of patients with transient ischemic attack or minor stroke. METHODS: This prospective cohort study enrolled emergency department patients from 13 hospitals with transient ischemic attack who had CT imaging. Primary outcome was stroke within 90 days. Secondary outcomes were stroke within 2 or 7 days. CT findings were abstracted from radiology reports and classified for the presence of acute ischemia, chronic ischemia, or microangiopathy. Multivariable logistic regression was used to test associations with primary and secondary end points. RESULTS: From 8670 prospectively enrolled patients between May 2010 and May 2017, 8382 had a CT within 24 hours. From this total population, 4547 (54%) patients had evidence of acute ischemia, chronic ischemia, or microangiopathy on CT, of whom 175 had a subsequent stroke within 90 days (3.8% subsequent stroke rate; adjusted odds ratio [aOR], 2.33 [95% CI, 1.62-3.36]). This was in comparison to those with CT imaging without ischemia. Findings associated with an increased risk of stroke at 90 days were isolated acute ischemia (6.0%; aOR, 2.42 [95% CI, 1.03-5.66]), acute ischemia with microangiopathy (10.7%; aOR, 3.34 [95% CI, 1.57-7.14]), chronic ischemia with microangiopathy (5.2%; aOR, 1.83 [95% CI, 1.34-2.50]), and acute ischemia with chronic ischemia and microangiopathy (10.9%; aOR, 3.49 [95% CI, 1.54-7.91]). Acute ischemia with chronic ischemia and microangiopathy were most strongly associated with subsequent stroke within 2 days (aOR, 4.36 [95% CI, 1.31-14.54]) and 7 days (aOR, 4.50 [95% CI, 1.73-11.69]). CONCLUSIONS: In patients with transient ischemic attack or minor stroke, CT evidence of acute ischemia with chronic ischemia or microangiopathy significantly increases the risk of subsequent stroke within 90 days of index visit. The combination of all 3 findings results in the greatest early risk.


Subject(s)
Brain Ischemia , Ischemic Attack, Transient , Stroke , Humans , Ischemic Attack, Transient/diagnostic imaging , Ischemic Attack, Transient/epidemiology , Ischemic Attack, Transient/complications , Prospective Studies , Neoplasm Recurrence, Local/complications , Stroke/diagnostic imaging , Stroke/epidemiology , Stroke/etiology , Brain Ischemia/diagnostic imaging , Brain Ischemia/epidemiology , Brain Ischemia/complications , Tomography, X-Ray Computed/adverse effects , Ischemia/complications
12.
Mol Cell Proteomics ; 22(3): 100503, 2023 03.
Article in English | MEDLINE | ID: mdl-36682716

ABSTRACT

Acute myeloid leukemia (AML) is the most common and aggressive form of acute leukemia, with a 5-year survival rate of just 24%. Over a third of all AML patients harbor activating mutations in kinases, such as the receptor tyrosine kinases FLT3 (receptor-type tyrosine-protein kinase FLT3) and KIT (mast/stem cell growth factor receptor kit). FLT3 and KIT mutations are associated with poor clinical outcomes and lower remission rates in response to standard-of-care chemotherapy. We have recently identified that the core kinase of the non-homologous end joining DNA repair pathway, DNA-PK (DNA-dependent protein kinase), is activated downstream of FLT3; and targeting DNA-PK sensitized FLT3-mutant AML cells to standard-of-care therapies. Herein, we investigated DNA-PK as a possible therapeutic vulnerability in KIT mutant AML, using isogenic FDC-P1 mouse myeloid progenitor cell lines transduced with oncogenic mutant KIT (V560G and D816V) or vector control. Targeted quantitative phosphoproteomic profiling identified phosphorylation of DNA-PK in the T2599/T2605/S2608/S2610 cluster in KIT mutant cells, indicative of DNA-PK activation. Accordingly, proliferation assays revealed that KIT mutant FDC-P1 cells were more sensitive to the DNA-PK inhibitors M3814 or NU7441, compared with empty vector controls. DNA-PK inhibition combined with inhibition of KIT signaling using the kinase inhibitors dasatinib or ibrutinib, or the protein phosphatase 2A activators FTY720 or AAL(S), led to synergistic cell death. Global phosphoproteomic analysis of KIT-D816V cells revealed that dasatinib and M3814 single-agent treatments inhibited extracellular signal-regulated kinase and AKT (RAC-alpha serine/threonine-protein kinase)/MTOR (serine/threonine-protein kinase mTOR) activity, with greater inhibition of both pathways when used in combination. Combined dasatinib and M3814 treatment also synergistically inhibited phosphorylation of the transcriptional regulators MYC and MYB. This study provides insight into the oncogenic pathways regulated by DNA-PK beyond its canonical role in DNA repair and demonstrates that DNA-PK is a promising therapeutic target for KIT mutant cancers.


Subject(s)
DNA-Activated Protein Kinase , Leukemia, Myeloid, Acute , Animals , Mice , Apoptosis , Cell Line, Tumor , Dasatinib , DNA , DNA-Activated Protein Kinase/genetics , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/drug therapy , Mutation , Protein Kinase Inhibitors/pharmacology , Receptor Protein-Tyrosine Kinases , Serine , Signal Transduction , Threonine , TOR Serine-Threonine Kinases , Tyrosine
13.
Acad Med ; 98(3): 394-400, 2023 03 01.
Article in English | MEDLINE | ID: mdl-35921150

ABSTRACT

PURPOSE: Health professions educators are increasingly called on to engage learners in more meaningful instruction. Many have used Wikipedia to offer an applied approach to engage learners, particularly learning related to evidence-based medicine (EBM). However, little is known about the benefits and challenges of using Wikipedia as a pedagogic tool from the collective experience of educators who have sought to improve their instructional practice with it. This study aims to synthesize the perspectives of health professions education (HPE) instructors on the incorporation of Wikipedia editing into their HPE courses. METHOD: Applying a constructivist approach, the authors conducted semistructured interviews from July to December 2020, with 17 participating HPE instructors who had substantively integrated Wikipedia into their curriculum at 13 institutions. Participants were interviewed about their experiences of integrating Wikipedia editing into their courses. Thematic analysis was conducted on resulting transcripts. RESULTS: The authors observed 2 broad themes among participants' expressed benefits of teaching with Wikipedia. First, Wikipedia provides a meaningful instructional alternative that also helps society and develops learners' information literacy and EBM skills. Second, Wikipedia supports learners' careers and professional identity formation. Identified challenges included high effort and time, restrictive Wikipedia sourcing guidelines, and difficult interactions with stakeholders. CONCLUSIONS: Findings build on known benefits, such as providing a real-world collaborative project that contextualizes students' learning experiences. They also echo known challenges, such as the resource-intensive nature of teaching with Wikipedia. The findings of this study reveal the potential of Wikipedia to enculturate HPE students within a situated learning context. They also present implications for HPE programs that are considering implementing Wikipedia and faculty development needed to help instructors harness crowd-sourced information tools' pedagogic opportunities as well as anticipate their challenges.


Subject(s)
Learning , Students, Health Occupations , Humans , Curriculum , Health Occupations , Evidence-Based Medicine/education , Teaching
14.
Med Sci Educ ; 32(6): 1553-1561, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36532387

ABSTRACT

Fostering skills in research is important for medical schools. This scoping review examined undergraduate curricular structures devoted to research training and their outcomes. For the sixty papers meeting inclusion criteria, descriptive statistics and a thematic analysis were conducted. Forty (67%) articles described US programs, with 30 (50%) being mandatory. Timing of research training was variable across included studies with the majority (58%) describing embedded longitudinal curricula. Reported benefits included enhanced knowledge, improved research and writing skills, clarity around career plans, and mentoring relationships. There are many curricular structures for undergraduate research training, but no high-quality evidence to support particular designs.

15.
Clin Proteomics ; 19(1): 48, 2022 Dec 19.
Article in English | MEDLINE | ID: mdl-36536316

ABSTRACT

Global high-throughput phosphoproteomic profiling is increasingly being applied to cancer specimens to identify the oncogenic signaling cascades responsible for promoting disease initiation and disease progression; pathways that are often invisible to genomics analysis. Hence, phosphoproteomic profiling has enormous potential to inform and improve individualized anti-cancer treatment strategies. However, to achieve the adequate phosphoproteomic depth and coverage necessary to identify the activated, and hence, targetable kinases responsible for driving oncogenic signaling pathways, affinity phosphopeptide enrichment techniques are required and often coupled with offline high-pressure liquid chromatographic (HPLC) separation prior to nanoflow liquid chromatography-tandem mass spectrometry (nLC-MS/MS). These complex and time-consuming procedures, limit the utility of phosphoproteomics for the analysis of individual cancer patient specimens in real-time, and restrict phosphoproteomics to specialized laboratories often outside of the clinical setting. To address these limitations, here we have optimized a new protocol, phospho-heavy-labeled-spiketide FAIMS Stepped-CV DDA (pHASED), that employs online phosphoproteome deconvolution using high-field asymmetric waveform ion mobility spectrometry (FAIMS) and internal phosphopeptide standards to provide accurate label-free quantitation (LFQ) data in real-time. Compared with traditional single-shot LFQ phosphoproteomics workflows, pHASED provided increased phosphoproteomic depth and coverage (phosphopeptides = 4617 pHASED, 2789 LFQ), whilst eliminating the variability associated with offline prefractionation. pHASED was optimized using tyrosine kinase inhibitor (sorafenib) resistant isogenic FLT3-mutant acute myeloid leukemia (AML) cell line models. Bioinformatic analysis identified differential activation of the serine/threonine protein kinase ataxia-telangiectasia mutated (ATM) pathway, responsible for sensing and repairing DNA damage in sorafenib-resistant AML cell line models, thereby uncovering a potential therapeutic opportunity. Herein, we have optimized a rapid, reproducible, and flexible protocol for the characterization of complex cancer phosphoproteomes in real-time, a step towards the implementation of phosphoproteomics in the clinic to aid in the selection of anti-cancer therapies for patients.

16.
CJEM ; 24(8): 844-852, 2022 12.
Article in English | MEDLINE | ID: mdl-36260218

ABSTRACT

OBJECTIVE: Stroke presenting as dizziness is a diagnostic challenge in frontline settings, given the multitude of benign conditions that present similarly. The risk of stroke after episodic dizziness is unknown, leading to divergent guidance on optimal workup and management. Prior TIA risk scores have shown a history of dizziness is a negative predictor of subsequent stroke. Our objective was to assess the subsequent stroke risk within 90 days following emergency department assessment (ED) for isolated dizziness diagnosed as TIA during the index visit. METHODS: We conducted prospective, multicenter cohort studies at 13 Canadian EDs over 11 years. We enrolled patients diagnosed with TIA and compared patients with isolated dizziness to those with other neurological deficits. Our primary outcome was subsequent stroke within 90 days. Secondary outcomes were subsequent stroke within 2, 7, and 30 days, respectively, as well as subsequent TIA within 90 days. RESULTS: Only 4/483 (0.8%) patients with isolated dizziness had a stroke within 90 days compared to 320/11024 (2.9%) of those with any focal neurological sign or symptom (RR 0.29, 95% CI 0.11-0.76). Over the first 90 days, the two groups differ significantly in their probability of stroke (p = 0.007). Subsequent TIA was also significantly less common in the isolated dizziness group (1.7% vs. 5.6%, p = 0.001) with a relative risk of 0.30 (95% CI 0.15-0.60). CONCLUSION: The risk of subsequent stroke following ED presentation for TIA is low when the presenting symptoms are isolated dizziness.


RéSUMé: OBJECTIF: Les accidents vasculaires cérébraux (AVC) se présentant sous forme de vertiges constituent un défi diagnostique en première ligne, étant donné la multitude d'affections bénignes qui se présentent de la même manière. Le risque d'accident vasculaire cérébral (AVC) après des vertiges épisodiques est inconnu, ce qui donne lieu à des conseils divergents sur le bilan et la prise en charge optimaux. Des scores de risque d'AIT antérieurs ont montré que des antécédents de vertiges sont un facteur prédictif négatif d'accident vasculaire cérébral ultérieur. Notre objectif était d'évaluer le risque ultérieur d'accident vasculaire cérébral (AVC) dans les 90 jours suivant l'évaluation aux urgences d'un étourdissement isolé diagnostiqué comme un AIT lors de la visite de référence. MéTHODES: Nous avons mené des études de cohorte prospectives multicentriques dans 13 services d'urgence canadiens pendant 11 ans. Nous avons recruté des patients ayant reçu un diagnostic d'AIT et avons comparé les patients présentant des vertiges isolés à ceux présentant d'autres déficits neurologiques. Nous avons inscrit des patients ayant reçu un diagnostic d'AIT et comparé des patients ayant des étourdissements isolés à ceux présentant d'autres déficits neurologiques. Notre résultat primaire était l'AVC subséquent dans les 90 jours. Les résultats secondaires étaient l'AVC subséquent dans les 2, 7 et 30 jours, respectivement, ainsi que l'AIT subséquent dans les 90 jours. RéSULTATS: Seuls 4/483 (0,8 %) des patients présentant des vertiges isolés ont eu un AVC dans les 90 jours, contre 320/11 024 (2,9 %) de ceux présentant un signe ou symptôme neurologique focal (RR 0,29, IC 95 % 0,11-0,76). Au cours des 90 premiers jours, les deux groupes diffèrent significativement en termes de probabilité d'AVC (p = 0,007). L'AIT ultérieur était également significativement moins fréquent dans le groupe des vertiges isolés (1,7 % contre 5,6 %, p = 0,001) avec un risque relatif de 0,30 (IC 95 % 0,15-0,60). CONCLUSIONS: Le risque d'AVC ultérieur après une présentation aux urgences pour un AIT est faible lorsque les symptômes présentés sont des étourdissements isolés.


Subject(s)
Ischemic Attack, Transient , Stroke , Humans , Ischemic Attack, Transient/complications , Dizziness/complications , Prospective Studies , Canada , Stroke/diagnosis , Vertigo/complications , Risk Factors , Emergency Service, Hospital
17.
Proteomics ; 22(9): e2100227, 2022 05.
Article in English | MEDLINE | ID: mdl-35014747

ABSTRACT

The seminal vesicles are male accessory sex glands that contribute the major portion of the seminal plasma in which mammalian spermatozoa are bathed during ejaculation. In addition to conveying sperm through the ejaculatory duct, seminal vesicle secretions support sperm survival after ejaculation, and influence the female reproductive tract to promote receptivity to pregnancy. Analysis of seminal vesicle fluid (SVF) composition by proteomics has proven challenging, due to its highly biased protein signature with a small subset of dominant proteins and the difficulty of solubilizing this viscous fluid. As such, publicly available proteomic datasets identify only 85 SVF proteins in total. To address this limitation, we report a new preparative methodology involving sequential solubilization of mouse SVF in guanidine hydrochloride, acetone precipitation, and analysis by label-free mass spectrometry. Using this strategy, we identified 126 SVF proteins, including 83 previously undetected in SVF. Members of the seminal vesicle secretory protein family were the most abundant, accounting for 79% of all peptide spectrum matches. Functional analysis identified inflammation and formation of the vaginal plug as the two most prominent biological processes. Other notable processes included modulation of sperm function and regulation of the female reproductive tract immune environment. Together, these findings provide a robust methodological framework for future SVF studies and identify novel proteins with potential to influence both male and female reproductive physiology.


Subject(s)
Proteomics , Seminal Vesicles , Animals , Female , Male , Mammals , Mice , Pregnancy , Proteins/metabolism , Proteomics/methods , Semen/metabolism , Seminal Vesicles/metabolism , Spermatozoa/metabolism
18.
J Hist Behav Sci ; 58(2): 147-162, 2022 Apr.
Article in English | MEDLINE | ID: mdl-34674398

ABSTRACT

Drawing on personal testimonials and questions addressed to psychiatric hospital officials, this article explores how patients and their loved ones engaged with the idea of diagnosis in interwar and war-era America. I argue that diagnosis had synergies with intellectual sensibilities of American modernity, among them an enthusiasm for science and newness, a modernist sense of time that could be both forward- and backward-looking, and a knowable, interpreted self. While self-understanding and the creation of life narratives were more often considered the bailiwick of psychoanalysis in this period, understanding subjectivity and self-interpretation were not solely expressed in its conceptual vocabulary. Patient and family dialogs with diagnosis and psychiatric authorities allow for an illumination of the interaction between domestic intuitions, common sense, and folk wisdom, on the one hand, and institutional taxonomy, categorization, and scientific terminology on the other, or more broadly, between dispositions that are ostensibly antimodern and more modern ideas. I suggest that the protean and wide-ranging intellectual origins of the discipline of psychiatry, along with the inherent ambiguity of psychiatric diagnosis during the early 20th century, allowed patients to participate in their own medicalization in the most capacious way possible: by combining biology with diagnostic narrative capacities, as well as broader perceptions of morality and character. In the concluding reflection, I speculate about why it is that late 20th-century American critics and activists have tended to view diagnosis and medicalization as coercive and threatening, in contrast to earlier 20th-century patients and their intimate observers.


Subject(s)
Mental Disorders , Psychiatry , History, 20th Century , Hospitals, Psychiatric , Humans , Medicalization , Mental Disorders/diagnosis , Mental Disorders/history , Morals , Psychiatry/history
19.
Ann Intern Med ; 174(12): JC139, 2021 12.
Article in English | MEDLINE | ID: mdl-34871061

ABSTRACT

SOURCE CITATION: Lambrakis K, Papendick C, French JK, et al. Late outcomes of the RAPID-TnT randomized controlled trial: 0/1-hour high-sensitivity troponin T protocol in suspected ACS. Circulation. 2021;144:113-25. 33998255.


Subject(s)
Acute Coronary Syndrome , Troponin T , Humans
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