Method Validation Study of Dipstick Urinalysis as a Screening Tool for Sodium Nitrite Toxicity.

ABSTRACT: The incidence of suicide by intentional nitrite ingestion has increased since 2017. Limited options exist for commercial laboratory analysis for nitrite/nitrate. This study investigates the use of urine dipsticks for screening at autopsy for potential toxicity with sodium nitrite and, less commonly, alkyl nitrite. Archived samples of blood, urine, vitreous fluid, and gastric contents from 4 sodium nitrite/nitrate cases, 3 alkyl nitrite cases, and 4 control cases were tested using dipsticks. A rapid, strong positive result for nitrite was in the vitreous fluid of all 4-sodium nitrite/nitrate cases, along with 2 positive urine and 1 positive gastric. The 2 alkyl nitrite inhalation toxicity cases had no positive results. One alkyl nitrite ingestion case had a positive urine. The 4 controls had negative urine: equivocal results in 2 vitreous, and 1 positive gastric. Urine dipsticks are a useful adjunct to laboratory testing for nitrite toxicity and provide a rapid, cost-effective tableside result that may guide the need for further testing. Vitreous fluid and urine appear to be the most reliable specimens, although testing of gastric liquid may be useful to corroborate oral ingestion. Dipsticks may not be a reliable adjunct for testing for alkyl nitrite toxicity via inhalation route, likely due to the much lower nitrite concentration compared to nitrite ingestion cases.

A 3-Year Retrospective Review of Complex Suicides With a Review of the Literature.

ABSTRACT: Complex suicide is defined as death by the intentional use of more than 1 method to end one's life. Complex suicides can fit into the planned or premeditated category, where 2 or more methods are used simultaneously or in close succession, or unplanned, the use of 2 or more methods, in which the first method attempted fails (often because it is too unpleasant or painful), and another method is employed subsequently that is successful.A retrospective review of 3 years of suicide fatalities examined by the Washoe County Regional Medical Examiner's Office in Reno, Nevada, was conducted. A total of 725 suicide cases dated from April 1, 2020, to April 1, 2023, were reviewed, including autopsy, toxicology, and scene investigation reports. Among the 725 suicide cases reviewed, 19 cases (2.62%) of complex suicide were identified. Of those cases, 17 employed 2 methods, and 2 cases employed 3 methods. No cases were identified with >3 methods.In the 19 complex suicides that were identified, gender, age, marital status, military service, sexual orientation, religion, race, occupation, incident location, suicide note, suicidal ideation history, past suicide attempt, psychiatric disorders, and motive for suicide were examined in addition to methods used.

Self-Chiropractic Cervical Spinal Manipulation Resulting in Fatal Vertebral Artery Dissection: A Case Report and Review of the Literature.

ABSTRACT: Chiropractic cervical spinal manipulations have several complications and can result in vascular injury, including traumatic dissection of the vertebral arteries. A 43-year-old woman was admitted to the emergency department after performing a self-chiropractic spinal manipulation. She experienced headache and vomiting and was unresponsive with severe hypertension at the time of hospital admission. Clinical computerized tomography angiography showed narrowing of the right vertebral artery but was inconclusive for dissection or thrombosis. At autopsy, subacute dissection of the right vertebral artery was identified along with cerebral edema and herniation. A small peripheral pulmonary thromboembolism in the right lung was also seen. Neuropathology consultation confirmed the presence of diffuse cerebral edema and acute hypoxic-ischemic changes, with multifocal acute subarachnoid and intraparenchymal hemorrhage of the brain and spinal cord. This case presents a unique circumstance of a fatal vertebral artery dissection after self-chiropractic manipulation that, to the best of our knowledge, has not been previously described in the medical literature.

When Vaping Isn't Actually Safer: A Death From Toxic Alcohol Contaminated Vape Juice.

ABSTRACT: Vape juice is a diluent for e-cigarette active ingredients, nicotine or tetrahydrocannabinol (THC). Lack of strict regulation in vape juice production is a concern as ingredients and their concentrations may vary widely from the labeling.A 43-year-old woman was transported via ambulance to the hospital after ingesting homemade vape juice, presenting unresponsive with decerebrate posturing. She reportedly made a tincture combining a vape juice purchased online (containing "ethylene glycol") and THC for "endometriosis-related pain relief." Laboratory evaluation revealed anion gap metabolic acidosis, elevated serum lactate, and high serum osmolality. Urine fluoresced under Wood's lamp, and fomepizole was administered as an ethylene glycol antidote, but she expired the following afternoon. Clinical serum toxicology results returned after death revealed 235 mg/dL of methanol, and no ethylene glycol.Autopsy findings included ischemic changes of the gastrointestinal tract and cerebral edema with herniation. Postmortem toxicology performed on hospital admission blood revealed methanol (220 mg/dL), propylene glycol (59 mg/dL), Δ-9 THC and metabolites, and medications administered during hospitalization. The medical examiner determined the cause of death to be methanol and propylene glycol toxicity.To our knowledge, this is the first report of accidental death from ingestion of vape juice contaminated with toxic alcohol.

Neck Hemorrhage: Fact or Artifact?-A Retrospective Analysis of Patterns of Postmortem Anterior Neck Muscle Hemorrhages From Hypostasis Versus Strangulation.

ABSTRACT: Distinguishing artifactual postmortem hypostatic hemorrhages from injury is key to accurately diagnosing strangulation. Despite being a well-known phenomenon, the literature is limited. This retrospective case-control analysis characterizes anterior neck musculature hemorrhage patterns associated with postmortem artifact versus strangulation by comparing incidental neck hemorrhages noted on 20 autopsy reports from 2020 to 2021 to 10 strangulation controls from 2015 to 2021 in Northern Nevada. Cases were analyzed for body position and location/severity of musculature involvement. For artifact cases, 50.0% were prone, 40.0% supine, and 10.0% side-lying. A total of 55.6% of artifact cases and controls demonstrated neck hemorrhage laterality. A total of 80.0% of the prone cases versus 77.8% of supine had diffuse hemorrhage versus focal. A total of 63.2% of artifact cases involved the sternocleidomastoid versus 70.0% controls (P = 1.000), 26.3% involved soft tissues versus 20.0% (P = 1.000), 9.1% the sternohyoid versus 40.0% (P = 0.149), 27.3% the sternothyroid versus 60.0% (P = 0.198), 9.1% the thyrohyoid versus 10.0% (P = 1.000), 18.2% the omohyoid versus 30.0% (P = 0.635), and 10.0% the tongue versus 50.0% (P = 0.026). Despite the limitations, this study demonstrated that while prone positioning is a contributing factor to the development of anterior neck hemorrhages, there are other factors than postmortem hypostasis.

A realist evaluation of a London general practitioner trainer course.

Clinicians with teaching and training roles should be adequately trained and assessed. However, some debate exists as to what the nature of this training should be. Historically, a postgraduate certificate in education was a pre-requisite to becoming a GP trainer but this is changing with growing concern that such a pre-requisite might act as a deterrent to potential GP trainers. This research examines the impact of a scheme designed to provide an alternative, more practical and focused, pathway to becoming a GP trainer. We interviewed 26 course participants and stakeholders of the London GP Training Course (LGPTC), observed teaching sessions, and analysed course materials. We asked what elements of the course were and weren't effective, for whom, and under what circumstances. Here, we present a summary of our main findings - that GP trainers want to know practically, not theoretically, how to be a trainer; formative assessment boosts trainees' confidence in their own skills and abilities; short, practical GP training courses can help enhance the numbers of GP trainers; important questions remain about the role and value of educational theory in education faculty development.

Activation of a cGAS-STING-mediated immune response predicts response to neoadjuvant chemotherapy in early breast cancer.

BACKGROUND: The DNA-damage immune-response (DDIR) signature is an immune-driven gene expression signature retrospectively validated as predicting response to anthracycline-based therapy. This feasibility study prospectively evaluates the use of this assay to predict neoadjuvant chemotherapy response in early breast cancer. METHODS: This feasibility study assessed the integration of a novel biomarker into clinical workflows. Tumour samples were collected from patients receiving standard of care neoadjuvant chemotherapy (FEC + /-taxane and anti-HER2 therapy as appropriate) at baseline, mid- and post-chemotherapy. Baseline DDIR signature scores were correlated with pathological treatment response. RNA sequencing was used to assess chemotherapy/response-related changes in biologically linked gene signatures. RESULTS: DDIR signature reports were available within 14 days for 97.8% of 46 patients (13 TNBC, 16 HER2 + ve, 27 ER + HER2-ve). Positive scores predicted response to treatment (odds ratio 4.67 for RCB 0-1 disease (95% CI 1.13-15.09, P = 0.032)). DDIR positivity correlated with immune infiltration and upregulated immune-checkpoint gene expression. CONCLUSIONS: This study validates the DDIR signature as predictive of response to neoadjuvant chemotherapy which can be integrated into clinical workflows, potentially identifying a subgroup with high sensitivity to anthracycline chemotherapy. Transcriptomic data suggest induction with anthracycline-containing regimens in immune restricted, "cold" tumours may be effective for immune priming. TRIAL REGISTRATION: Not applicable (non-interventional study). CRUK Internal Database Number 14232.

Kratom-Associated Fatalities in Northern Nevada-What Mitragynine Level Is Fatal?

ABSTRACT: Mitragyna speciosa, commonly known as the kratom tree, has been utilized in Southeast Asia for centuries for its opioid-like effects. Kratom has been available in the United States for the past decade and has grown increasingly popular despite a lack of clinical research to determine its safety. With its widespread use, there have been an increasing number of fatalities. This study aims to establish a potential lethal range for mitragynine, the active compound in kratom, by investigating the toxicology reports of 35 deaths in Northern Nevada between 2015 and 2020. Mitragynine concentrations ranged from 8.7 to 1800 ng/mL (n = 27) in cases with drug toxicity as the cause of death; in 1 case, the sole intoxicant was mitragynine with a blood concentration of 950 ng/mL. In cases with nonmitragynine causes of death, the concentration was 110 to 980 ng/mL (n = 8). There was no statistically significant difference in blood concentrations between cases where mitragynine was not listed as a cause of death (mean, 315 ± 297.2 ng/mL) and cases in which mitragynine contributed to death (mean, 269.4 ± 382.5 ng/mL; P < 0.201). A literature review is also presented.

Evaluating Physical Functioning in Survivors of Critical Illness: Development of a New Continuum Measure for Acute Care.

OBJECTIVES: Evaluation of physical functioning is central to patient recovery from critical illness-it may enable the ability to determine recovery trajectories, evaluate rehabilitation efficacy, and predict individuals at highest risk of ongoing disability. The Physical Function in ICU Test-scored is one of four recommended physical functioning tools for use within the ICU; however, its utility outside the ICU is poorly understood. The De Morton Mobility Index is a common geriatric mobility tool, which has had limited evaluation in the ICU population. For the field to be able to track physical functioning recovery, we need a measurement tool that can be used in the ICU and post-ICU setting to accurately measure physical recovery. Therefore, this study sought to: 1) examine the clinimetric properties of two measures (Physical Function in ICU Test-scored and De Morton Mobility Index) and 2) transform these measures into a single measure for use across the acute care continuum. DESIGN: Clinimetric analysis. SETTING: Multicenter study across four hospitals in three countries (Australia, Singapore, and Brazil). PATIENTS: One hundred fifty-one ICU patients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Physical function tests (Physical Function in ICU Test-scored and De Morton Mobility Index) were assessed at ICU awakening, ICU, and hospital discharge. A significant floor effect was observed for the De Morton Mobility Index at awakening (23%) and minimal ceiling effects across all time points (5-12%). Minimal floor effects were observed for the Physical Function in ICU Test-scored across all time points (1-7%) and a significant ceiling effect for Physical Function in ICU Test-scored at hospital discharge (27%). Both measures had strong concurrent validity, responsiveness, and were predictive of home discharge. A new measure was developed using Rasch analytical principles, which involves 10 items (scored out of 19) with minimal floor/ceiling effects. CONCLUSIONS: Limitations exist for Physical Function in ICU Test-scored and De Morton Mobility Index when used in isolation. A new single measure was developed for use across the acute care continuum.

Immune activation by DNA damage predicts response to chemotherapy and survival in oesophageal adenocarcinoma.

OBJECTIVE: Current strategies to guide selection of neoadjuvant therapy in oesophageal adenocarcinoma (OAC) are inadequate. We assessed the ability of a DNA damage immune response (DDIR) assay to predict response following neoadjuvant chemotherapy in OAC. DESIGN: Transcriptional profiling of 273 formalin-fixed paraffin-embedded prechemotherapy endoscopic OAC biopsies was performed. All patients were treated with platinum-based neoadjuvant chemotherapy and resection between 2003 and 2014 at four centres in the Oesophageal Cancer Clinical and Molecular Stratification consortium. CD8 and programmed death ligand 1 (PD-L1) immunohistochemical staining was assessed in matched resection specimens from 126 cases. Kaplan-Meier and Cox proportional hazards regression analysis were applied according to DDIR status for recurrence-free survival (RFS) and overall survival (OS). RESULTS: A total of 66 OAC samples (24%) were DDIR positive with the remaining 207 samples (76%) being DDIR negative. DDIR assay positivity was associated with improved RFS (HR: 0.61; 95% CI 0.38 to 0.98; p=0.042) and OS (HR: 0.52; 95% CI 0.31 to 0.88; p=0.015) following multivariate analysis. DDIR-positive patients had a higher pathological response rate (p=0.033), lower nodal burden (p=0.026) and reduced circumferential margin involvement (p=0.007). No difference in OS was observed according to DDIR status in an independent surgery-alone dataset.DDIR-positive OAC tumours were also associated with the presence of CD8+ lymphocytes (intratumoural: p<0.001; stromal: p=0.026) as well as PD-L1 expression (intratumoural: p=0.047; stromal: p=0.025). CONCLUSION: The DDIR assay is strongly predictive of benefit from DNA-damaging neoadjuvant chemotherapy followed by surgical resection and is associated with a proinflammatory microenvironment in OAC.

High EMSY expression defines a BRCA-like subgroup of high-grade serous ovarian carcinoma with prolonged survival and hypersensitivity to platinum.

BACKGROUND: Approximately half of high-grade serous ovarian carcinomas (HGSOCs) demonstrate homologous recombination repair (HR) pathway defects, resulting in a distinct clinical phenotype comprising hypersensitivity to platinum, superior clinical outcome, and greater sensitivity to poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitors. EMSY, which is known to be amplified in breast and ovarian cancers, encodes a protein reported to bind and inactivate BRCA2. Thus, EMSY overexpression may mimic BRCA2 mutation, resulting in HR deficiency. However, to our knowledge, the phenotypic consequences of EMSY overexpression in HGSOC patients has not been explored. METHODS: Here we investigate the impact of EMSY expression on clinical outcome and sensitivity to platinum-based chemotherapy using available data from transcriptomically characterized HGSOC cohorts. RESULTS: High EMSY expression was associated with better clinical outcome in a cohort of 265 patients with HGSOC from Edinburgh (overall survival multivariable hazard ratio, 0.58 [95% CI, 0.38-0.88; P = .011] and progression-free survival multivariable hazard ratio, 0.62 [95% CI, 0.40-0.96; P = .030]). Superior outcome also was demonstrated in the Medical Research Council ICON7 clinical trial and multiple publicly available data sets. Patients within the Edinburgh cohort who had high EMSY expression were found to demonstrate greater rates of complete response to multiple platinum-containing chemotherapy regimens (radiological complete response rate of 44.4% vs 12.5% at second exposure; P = .035) and corresponding prolonged time to disease progression (median, 151.5 days vs 60.5 days after third platinum exposure; P = .004). CONCLUSIONS: Patients with HGSOCs demonstrating high EMSY expression appear to experience prolonged survival and greater platinum sensitivity, reminiscent of BRCA-mutant cases. These data are consistent with the notion that EMSY overexpression may render HGSOCs HR deficient.

Gene Expression Signature for Prediction of Golimumab Response in a Phase 2a Open-Label Trial of Patients With Ulcerative Colitis.

Golimumab, a tumor necrosis factor antagonist, is an effective treatment for patients with moderate-to-severe ulcerative colitis (UC); however, more than 50% of initial responders lose their response to the drug within the first year of therapy. A gene expression signature identified in colon biopsies collected before treatment was associated with response to infliximab, and was subsequently refined to associate with mucosal healing in response to golimumab. We performed a phase 2a open-label study of 103 golimumab-treated patients with moderate-to-severe UC to test whether the baseline gene expression signature could be used to predict which patients would achieve mucosal healing, clinical response, and clinical remission at weeks 6 and 30 of treatment. The gene expression signature identified patients who went on to achieve mucosal healing at treatment week 6 with an area under the receiver operating characteristic curve (AUCROC) of 0.688 (P = .002) and at week 30 with an AUCROC of 0.671 (P = .006). The signature identified patients with mucosal healing with 87% sensitivity, but only 34% specificity, limiting its clinical utility. The baseline gene expression signature did not identify patients who went on to achieve clinical remission or clinical response with statistical significance. Further studies are needed to identify biomarkers that can be used to predict which patients with UC will respond to treatment with anti-tumor necrosis factor agents. ClinicalTrials.gov no: NCT01988961.

Merkel Cell Polyomavirus Small T Antigen Drives Cell Motility via Rho-GTPase-Induced Filopodium Formation.

Cell motility and migration is a complex, multistep, and multicomponent process intrinsic to progression and metastasis. Motility is dependent on the activities of integrin receptors and Rho family GTPases, resulting in the remodeling of the actin cytoskeleton and formation of various motile actin-based protrusions. Merkel cell carcinoma (MCC) is an aggressive skin cancer with a high likelihood of recurrence and metastasis. Merkel cell polyomavirus (MCPyV) is associated with the majority of MCC cases, and MCPyV-induced tumorigenesis largely depends on the expression of the small tumor antigen (ST). Since the discovery of MCPyV, a number of mechanisms have been suggested to account for replication and tumorigenesis, but to date, little is known about potential links between MCPyV T antigen expression and the metastatic nature of MCC. Previously, we described the action of MCPyV ST on the microtubule network and how it impacts cell motility and migration. Here, we demonstrate that MCPyV ST affects the actin cytoskeleton to promote the formation of filopodia through a mechanism involving the catalytic subunit of protein phosphatase 4 (PP4C). We also show that MCPyV ST-induced cell motility is dependent upon the activities of the Rho family GTPases Cdc42 and RhoA. In addition, our results indicate that the MCPyV ST-PP4C interaction results in the dephosphorylation of ß1 integrin, likely driving the cell motility pathway. These findings describe a novel mechanism by which a tumor virus induces cell motility, which may ultimately lead to cancer metastasis, and provides opportunities and strategies for targeted interventions for disseminated MCC.IMPORTANCE Merkel cell polyomavirus (MCPyV) is the most recently discovered human tumor virus. It causes the majority of cases of Merkel cell carcinoma (MCC), an aggressive skin cancer. However, the molecular mechanisms implicating MCPyV-encoded proteins in cancer development are yet to be fully elucidated. This study builds upon our previous observations, which demonstrated that the MCPyV ST antigen enhances cell motility, providing a potential link between MCPyV protein expression and the highly metastatic nature of MCC. Here, we show that MCPyV ST remodels the actin cytoskeleton, promoting the formation of filopodia, which is essential for MCPyV ST-induced cell motility, and we also implicate the activity of specific Rho family GTPases, Cdc42 and RhoA, in these processes. Moreover, we describe a novel mechanism for the activation of Rho-GTPases and the cell motility pathway due to the interaction between MCPyV ST and the cellular phosphatase catalytic subunit PP4C, which leads to the specific dephosphorylation of ß1 integrin. These findings may therefore provide novel strategies for therapeutic intervention for disseminated MCC.

A postgraduate curriculum for integrated care: a qualitative exploration of trainee paediatricians and general practitioners' experiences.

BACKGROUND: Integrated care unites funding, administrative, organisational, service delivery and clinical levels to create connectivity, alignment and collaboration within and between care delivery and prevention sectors. It aims to improve efficiency by avoiding unnecessary duplication of resources. Consequently, implementing integrated care is increasingly important; however, there are many barriers and how we teach healthcare practitioners to work across systems is under-researched. This paper explores an innovative educational curriculum, the Programme for Integrated Child Health (PICH). METHODS: The PICH involved an experiential learning approach supported by taught sessions on specific issues relevant to integrated care. A qualitative study was conducted by interviewing 23 participants using semi-structured one-to-one interviews. Participants included trainees (general practice, paediatrics) and programme mentors. Data was thematically analysed. RESULTS: Results are coded under three main themes: integrated care curriculum components, perceptions of a curriculum addressing integrated care and organisational change, and personal and professional learning. The data highlights the importance of real-world projects, utilising healthcare data, and considering patient perspectives to understand and develop integrated practices. Trainees received guidance from mentors but, more crucially learnt from, with, and about one another. They learnt about the context in which GPs and paediatricians work and developed a deeper understanding through which integrated services could be meaningfully developed. CONCLUSIONS: This study explored participants' experiences and can be taken forward by educationalists to design curricula to better prepare healthcare practitioners to work collaboratively. The emergence of integrated care brings about challenges for traditional pedagogical approaches as learners have to re-align their discipline-specific approaches with evolving healthcare structures. PICH demonstrated that trainees acquired knowledge through real-word projects and experiential learning; and that this facilitated integration, empowering doctors to become leaders of organisational change. However, there are also many challenges of implementing integrated curricula which need to be addressed, including breaking down professional silos and integrating resourceful healthcare. This study begins to demonstrate the ability of an integrated curriculum to support trainees to work collaboratively, but further work is needed to develop the wider efficacy of the programme incorporating other professional groups, and to assess its longer term impact.

Patterns in Forensic Decapitations: A Review of the Literature and Case Report.

Separation of the head from the body can occur for a variety of reasons and in various locations across the neck. This study presents a review of the literature to identify the patterns of decapitations in forensic cases in relation to manner of death, age, and anatomical location (n = 88). The most common manner of death was suicide, followed by homicide and then accident. Ages ranged from 32 weeks prenatal to 85 years. Decapitation is reported at higher rates for individuals between 19 and 65. The majority of decapitations occurred at the midneck (second to fifth cervical vertebrae), followed by the upper neck and then the lower neck. This pattern holds true for all manners of death; however, in homicides, the percentage occurring at the midneck decreases. The findings of this study indicate some patterns in terms of manner of death, age, and location of decapitation, which could aid the medicolegal community in interpreting neck trauma. A case study is also briefly presented to illustrate findings.

The effect of postsurgical pain on attentional processing in horses.

OBJECTIVE: To investigate the effect of postsurgical pain on the performance of horses in a novel object and auditory startle task. STUDY DESIGN: Prospective clinical study. ANIMALS: Twenty horses undergoing different types of surgery and 16 control horses that did not undergo surgery. METHODS: The interaction of 36 horses with novel objects and a response to an auditory stimulus were measured at two time points; the day before surgery (T1) and the day after surgery (T2) for surgical horses (G1), and at a similar time interval for control horses (G2). Pain and sedation were measured using simple descriptive scales at the time the tests were carried out. Total time or score attributed to each of the behavioural categories was compared between groups (G1 and G2) for each test and between tests (T1 and T2) for each group. RESULTS: The median (range) time spent interacting with novel objects was reduced in G1 from 58 (6-367) seconds in T1 to 12 (0-495) seconds in T2 (p=0.0005). In G2 the change in interaction time between T1 and T2 was not statistically significant. Median (range) total auditory score was 7 (3-12) and 10 (1-12) in G1 and G2, respectively, at T1, decreasing to 6 (0-10) in G1 after surgery and 9.5 (1-12) in G2 (p=0.0003 and p=0.94, respectively). There was a difference in total auditory score between G1 and G2 at T2 (p=0.0169), with the score being lower in G1 than G2. CONCLUSIONS AND CLINICAL RELEVANCE: Postsurgical pain negatively impacts attention towards novel objects and causes a decreased responsiveness to an auditory startle test. In horses, tasks demanding attention may be useful as a biomarker of pain.

Merkel cell polyomavirus small T antigen mediates microtubule destabilization to promote cell motility and migration.

UNLABELLED: Merkel cell carcinoma (MCC) is an aggressive skin cancer of neuroendocrine origin with a high propensity for recurrence and metastasis. Merkel cell polyomavirus (MCPyV) causes the majority of MCC cases due to the expression of the MCPyV small and large tumor antigens (ST and LT, respectively). Although a number of molecular mechanisms have been attributed to MCPyV tumor antigen-mediated cellular transformation or replication, to date, no studies have investigated any potential link between MCPyV T antigen expression and the highly metastatic nature of MCC. Here we use a quantitative proteomic approach to show that MCPyV ST promotes differential expression of cellular proteins implicated in microtubule-associated cytoskeletal organization and dynamics. Intriguingly, we demonstrate that MCPyV ST expression promotes microtubule destabilization, leading to a motile and migratory phenotype. We further highlight the essential role of the microtubule-associated protein stathmin in MCPyV ST-mediated microtubule destabilization and cell motility and implicate the cellular phosphatase catalytic subunit protein phosphatase 4C (PP4C) in the regulation of this process. These findings suggest a possible molecular mechanism for the highly metastatic phenotype associated with MCC. IMPORTANCE: Merkel cell polyomavirus (MCPyV) causes the majority of cases of Merkel cell carcinoma (MCC), an aggressive skin cancer with a high metastatic potential. However, the molecular mechanisms leading to virally induced cancer development have yet to be fully elucidated. In particular, no studies have investigated any potential link between the virus and the highly metastatic nature of MCC. We demonstrate that the MCPyV small tumor antigen (ST) promotes the destabilization of the host cell microtubule network, which leads to a more motile and migratory cell phenotype. We further show that MCPyV ST induces this process by regulating the phosphorylation status of the cellular microtubule-associated protein stathmin by its known association with the cellular phosphatase catalytic subunit PP4C. These findings highlight stathmin as a possible biomarker of MCC and as a target for novel antitumoral therapies.

Quantitative measurement of acetyl fentanyl and acetyl norfentanyl in human urine by LC-MS/MS.

Opioid abuse involving emerging opioid compounds is a growing public health problem, which was highlighted recently by cases of human morbidity and mortality linked to acetyl fentanyl abuse. Unfortunately, the lack of information available on the toxicology and metabolism of acetyl fentanyl precludes its detection in human samples. The following study was conducted to test a new analytical procedure for the simultaneous quantification of acetyl fentanyl and its predicted metabolite, acetyl norfentanyl, in human urine. Metabolic reference standards and deuterium-labeled internal standards were synthesized for use in an assay that coupled solid-phase extraction (SPE) with liquid chromatography-tandem mass spectrometry (LC-MS/MS). The accuracy (% Relative Error <5%) and inter- and intrarun precision (%CV <20%) of this new method resulted in low levels of quantification (∼1 ng/mL). Similar results were obtained using liquid chromatography columns manufactured with phenyl-hexyl and biphenyl stationary phases (r(2) > 0.98). Preliminary human liver microsomal and in vivo rodent studies demonstrated that acetyl fentanyl is metabolized by cytochrome P450s to acetyl norfentanyl. Urine samples from rats treated with a toxic dose of acetyl fentanyl contained high concentrations of acetyl fentanyl and acetyl norfentanyl. Further toxicokinetic studies are required to fully elucidate the metabolic pathways responsible for acetyl fentanyl detoxification and excretion.

Merkel cell polyomavirus small T antigen targets the NEMO adaptor protein to disrupt inflammatory signaling.

Merkel cell carcinoma (MCC) is a highly aggressive nonmelanoma skin cancer arising from epidermal mechanoreceptor Merkel cells. In 2008, a novel human polyomavirus, Merkel cell polyomavirus (MCPyV), was identified and is strongly implicated in MCC pathogenesis. Currently, little is known regarding the virus-host cell interactions which support virus replication and virus-induced mechanisms in cellular transformation and metastasis. Here we identify a new function of MCPyV small T antigen (ST) as an inhibitor of NF-κB-mediated transcription. This effect is due to an interaction between MCPyV ST and the NF-κB essential modulator (NEMO) adaptor protein. MCPyV ST expression inhibits IκB kinase α (IKKα)/IKKß-mediated IκB phosphorylation, which limits translocation of the NF-κB heterodimer to the nucleus. Regulation of this process involves a previously undescribed interaction between MCPyV ST and the cellular phosphatase subunits, protein phosphatase 4C (PP4C) and/or protein phosphatase 2A (PP2A) Aß, but not PP2A Aα. Together, these results highlight a novel function of MCPyV ST to subvert the innate immune response, allowing establishment of early or persistent infection within the host cell.

The RNA binding proteins LARP4A and LARP4B promote sarcoma and carcinoma growth and metastasis.

RNA-binding proteins (RBPs) are emerging as important regulators of cancer pathogenesis. We reveal that the RBPs LARP4A and LARP4B are differentially overexpressed in osteosarcoma and osteosarcoma lung metastases, as well as in prostate cancer. Depletion of LARP4A and LARP4B reduced tumor growth and metastatic spread in xenografts, as well as inhibiting cell proliferation, motility, and migration. Transcriptomic profiling and high-content multiparametric analyses unveiled a central role for LARP4B, but not LARP4A, in regulating cell cycle progression in osteosarcoma and prostate cancer cells, potentially through modulating key cell cycle proteins such as Cyclins B1 and E2, Aurora B, and E2F1. This first systematic comparison between LARP4A and LARP4B assigns new pro-tumorigenic functions to LARP4A and LARP4B in bone and prostate cancer, highlighting their similarities while also indicating distinct functional differences. Uncovering clear biological roles for these paralogous proteins provides new avenues for identifying tissue-specific targets and potential druggable intervention.