Citations

Introduction Clinical assessment in emergency departments (EDs) for possible acute myocardial infarction (AMI) requires at least one cardiac troponin (cTn) blood test. The turn-around time from blood draw to posting results in the clinical portal for central laboratory analysers is ~1–2 hours. New generation, high-sensitivity, point-of-care cardiac troponin I (POC-cTnI) assays use whole blood on a bedside (or near bedside) analyser that provides a rapid (8 min) result. This may expedite clinical decision-making and reduce length of stay. Our purpose is to determine if utilisation of a POC-cTnI testing reduces ED length of stay. We also aim to establish an optimised implementation process for the amended clinical pathway. Methods and analysis This quality improvement initiative has a pragmatic multihospital stepped-wedge cross-sectional cluster randomised design. Consecutive patients presenting to the ED with symptoms suggestive of possible AMI and having a cTn test will be included. Clusters (comprising one or two hospitals each) will change from their usual-care pathway to an amended pathway using POC-cTnI—the ‘intervention’. The dates of change will be randomised. Changes occur at 1 month intervals, with a minimum 2 month ‘run-in’ period. The intervention pathway will use a POC-cTnI measurement as an alternate to the laboratory-based cTn measurement. Clinical decision-making steps and logic will otherwise remain unchanged. The POC-cTnI is the Siemens (Erlangen Germany) Atellica VTLi high-sensitivity cTnI assay. The primary outcome is ED length of stay. The safety outcome is cardiac death or AMI within 30 days for patients discharged directly from the ED. Ethics and dissemination Ethics approval has been granted by the New Zealand Southern Health and Disability Ethics Committee, reference 21/STH/9. Results will be published in a peer-reviewed journal. Lay and academic presentations will be made. Māori-specific results will be disseminated to Māori stakeholders. Trial registration number ACTRN12619001189112.

AbstractINTRODUCTIONFemale‐specific reproductive factors and exogeneous estrogen use are associated with cognition in later life. However, the underlying mechanisms are not understood. The present study aimed to investigate the effect of reproductive factors on neuroimaging biomarkers of Alzheimer's disease (AD) and cerebrovascular pathologies.METHODSWe evaluated 389 females (median age of 71.7 years) enrolled in the Mayo Clinic Study of Aging with reproductive history data and longitudinal magnetic resonance imaging (MRI) scans. We used linear mixed effect models to examine the associations between reproductive factors and changes in neuroimaging measures.RESULTSEver hormonal contraception (HC) use was longitudinally associated with higher fractional anisotropy across the corpus callosum, lower white matter hyperintensity (WMH) volume, and greater cortical thickness in an AD meta‐region of interest (ROI). The initiation of menopausal hormone therapy (MHT) > 5 years post menopause was associated with higher WMH volume.DISCUSSIONHC use and initiation of MHT >5 years post menopause were generally associated with neuroimaging biomarkers of cerebrovascular pathologies.Highlights Hormonal contraception use was associated with better brain white matter (WM) integrity. Initiation of menopausal hormone therapy >5 years post menopause was associated with worsening brain WM integrity. Hormonal contraception use was associated with greater cortical thickness. Ages at menarche and menopause and number of pregnancies were not associated with imaging measures. There were few associations between reproductive factors or exogenous estrogens and amyloid or tau PET.

6006 Background: IMPT has unique biologic and physical properties compared with IMRT, limits radiation dose beyond the targeted tumor volumes, and is a novel de-intensification strategy for the management of head and neck tumors. This study was designed to compare the outcomes for patients with OPC after chemoradiation therapy (CRT) with IMRT vs IMPT. Methods: This is a multi-center, randomized, phase III non-inferiority OPC trial Stage III/IV (AJCC 7th) squamous cell carcinoma stratified patients by human papillomavirus status, smoking status, and receipt of induction chemotherapy (IC). The primary endpoint was the rate of progression-free survival (PFS) rate at 3 years, where progression was defined as disease recurrence or death. Under the null hypothesis, H0: r ≥ 1.535 established the margin for non-inferiority of IMPT. Secondary endpoints include overall survival (OS), treatment-related malnutrition, and gastrostomy-tube dependence. Analyses were conducted on intent-to-treat (ITT; n=440), per-protocol (PP; n=296), and as-treated (AT; n=397) populations. Results: Patients (n=440) were randomized to undergo IMRT(n=219) or IMPT (n=221) at 21 institutions. The median age was 61 years and HPV/p16 was positive in 95%. IC was the initial treatment in 13% of patients. All patients were treated with CRT to 70 Gy in 33 fx with bilateral neck treatment, and post-CRT surgical lymph node dissection occurred in 8%. The median follow-up was 3.14 years. In the ITT analysis, the hazard ratio (HR) for disease progression or death at 3 y was 0.87 (95%CI 0.56,1.35); p=0.006 and the corresponding HR for death (OS) was 0.63 (95%CI 0.36-1.10) suggesting a protective affect with IMPT. In PP analysis, the PFS HR was 0.85 (95%CI 0.52,1.38); p=0.009 and HR for death (OS) was 0.60 (95%CI 0.32-1.12). In the AT analysis, PFS HR was 0.88 (95%CI 0.56,1.37); p=0.007 and the corresponding HR for death (OS) was 0.70 (95%CI 0.40-1.22). For each analysis above, the null hypothesis was rejected and IMPT was non-inferior to IMRT. PP gastrostomy-tube dependence decreased with IMPT vs. IMRT from 42% to 28% (p=0.019), and more IMPT patients sustained their nutrition with end of treatment weight loss < 5% from baseline: 24% vs 14% (p=0.037). Conclusions: IMPT is non-inferior to IMRT and has emerged as a standard of care CRT approach for OPC that reduces malnutrition and gastrostomy-tube dependence. Clinical trial information: NCT01893307 .

3520 Background: In patients with metastatic colorectal cancer (CRC) and deficient DNA mismatch repair (dMMR), we previously found transcriptomic signatures reflecting stromal compartment composition and proliferative capacity that can predict the efficacy of immune checkpoint blockade (ICB). To identify proteomic markers of response and/or resistance to ICB, we performed spatially resolved proteomic analysis of the tumor microenvironment. Methods: Patients with surgically resected, primary dMMR metastatic CRCs received pembrolizumab (Mayo Clinic, N=30). In FFPE tissues, Digital Spatial Profiling of 71 proteins was performed using panels covering immune cells, immune activation, cell death, PI3/AKT signaling, MAPK signaling, and pan-tumor markers (GeoMx nCounter). In ten regions of interest/slide (~600 µm2) at the tumor invasive margin, protein expression was determined in four cellular compartments: epithelium (panCK+), immune cells (CD45+; leucocyte common antigen), stroma (panCK-), and nonimmune stroma (panCK-/CD45-). After normalization, protein abundance per compartment was analyzed by response (RECIST 1.1) [OmicVerse Python]. Differentially expressed proteins (binary) were examined by progression-free survival (PFS) using multivariable Cox regression with covariate adjustment (Lifelines Python). Results: Pre-treatment panels including 71 proteins were analyzed by treatment response and PFS after PD-1 inhibition. Proteins found to be significantly associated with response (p< 0.01) and PFS are described. Across all compartments, responders showed upregulation of NK cells and T cell subsets (CD3+, CD4+, CD8+), and ICOS; strongest association was found for CD4+: HRadj: 0.16; 95%CI: 0.08-0.31; p< 0.001. Nonresponders showed higher phospho-JNK (HRadj: 2.09; 95%CI: 1.28-3.42; p=0.003) and SMA. In the epithelial compartment, upregulation of the Treg marker CD25 and reduced caspase-9 were observed in responders. Among responders, the stromal compartment was highly enriched in HLA-DR, dendritic cells (CD11c), PD-L1, immune activation markers (CD40, CD44, CD80, CD27), CD95/Fas, and GZMB. In the stromal compartment, downregulation of BCL6 and phospho-GSK3B was observed in responders. The immune compartment of responders showed increased beta2-microglobulin and Ki-67, while the non-immune stromal compartment showed increase in the macrophage marker CD68. Importantly, proteins found to be upregulated in responders were significantly and independently associated with longer PFS whereas the opposite was true for nonresponders. Conclusions: In metastatic dMMR CRCs, spatially defined protein markers were significantly associated with anti-PD-1 response, and independently associated with patient PFS (strongest predictive utility for CD4 in immune stroma and phospho-JNK in epithelium).

2015 Background: Effective treatments for recurrent meningiomas following radiation therapy (RT) are limited. Inhibitors of the programmed-death-1 (PD-1) or programmed-death ligand-1 (PD-L1) pathway have shown modest activity for these tumors in single-arm phase 2 studies. This study aims to evaluate the immunological effects of combining anti-PD-L1 (avelumab) with proton beam therapy (PBT) for recurrent radiation-relapsed meningiomas. Methods: Recurrent grade 1-3 meningiomas that failed prior surgery and RT were treated with neoadjuvant avelumab (10 mg/kg IV biweekly for 6 doses) plus hypofractionated PBT (20 Gy over 5 fractions), followed by surgery and additional adjuvant avelumab (up to 6 doses). Blood samples were collected pre-avelumab, at week 4, and before surgery. Eligibility criteria include age ≥ 18 years, KPS ≥ 60, surgery suitability, dexamethasone dose ≤ 4mg daily, normal organ function; no prior anti-PD1/PDL1 therapy, and absence of autoimmunity. RNA-sequencing (RNAseq) and multiplex immunofluorescence (MxIF) were performed on pre- and post-avelumab tumor tissues; blood samples underwent multiplex flow cytometry (MxFC). Results: Between March 2018 to March 2023, 9 patients (22% grade 1, 56% grade 2, and 22% grade 3) were enrolled in the study. All completed neoadjuvant therapy, one forwent surgery due to dramatic radiological response, and two did not complete adjuvant avelumab (due to patient preference and infusion reaction). There was no dose-limiting toxicity or unexpected toxicity. After a median follow-up of 43.0 month and a minimum follow-up of 21.7 months, 8 patients have progressed, and 2 patients with progression have died. The median progression-free survival (PFS) was 19.1 months (95% CI: 15.2-23.0), with the median overall survival not yet reached. Three patients demonstrated notably prolonged PFS (37.7, 58.5 months, and ongoing). RNAseq showed significant increase in T-cell and macrophage gene expression in post-treatment tissues compared to pre-treatment. MxIF revealed a marked increase in T-cell and CD68+ macrophage infiltration in the long-PFS patients’ post-treatment tissues, a pattern not observed in the short-PFS patients. Particularly, the long-PFS patients’ post-treatment tissues displayed increased infiltration of CD68+HLADR+ macrophages, likely of M1-phenotype. In contrast, the pre- and post-treatment tissues from the short-PFS patients predominantly featured CD206+ macrophages, likely of M2-phenotype. A trend towards increased number of primed T cells in the peripheral blood was observed in the long-PFS patients at week 4. Conclusions: Avelumab combined with RT may induce an immunological response in some radiation-relapsed meningioma patients, leading to prolonged remission. Further investigations with larger prospective studies and predictive biomarkers are warranted. Clinical trial information: NCT03267836 .

10015 Background: The Children’s Oncology Group developed and implemented a unified method of dosing anticancer drugs in infants and small children with a BSA < 0.6 m2. The dosing tables use BSA-based dose banding and account for deliverable doses/volumes of the drugs. We studied the PK of VCR (1.5 mg/m2 dose level) in infants and children to determine whether this new infant dosing method achieves uniform drug exposures across the pediatric age span. Methods: We designed a sampling strategy to limit the blood volume required by focusing on the elimination (β) phase of the VCR concentration-time curve, which accounts for > 80% of the total area-under the curve (AUC). Duplicate samples to detect contamination were drawn at 3 post-infusion time points (2, 6-8 and 18-24 hr) through a central venous catheter (CVC) after a 90 min flush. VCR concentrations were measured at the Children’s Hospital of Philadelphia using a validated high-pressure liquid chromatography/tandem mass spectrometry method with a lower limit of quantitation (LLQ) of 0.25 ng/mL. A one-compartment model was fit to the concentration-time data using population PK methods (Phoenix NLME). The AUCβ was derived from the dose and clearance for each patient. Patients were accrued in 4 age groups (≤6 mo, goal n = 20); > 6 mo to ≤12 mo, goal n = 10; > 12 mo to ≤36 mo, goal n = 10; and > 36 mo to ≤12 yr, goal n = 10) to focus on infants and ensure representation across the pediatric age range. Results: 52 eligible patients have been enrolled and 39 are evaluable for PK analysis, including 9 ≤6 mo, 8 > 6 mo and ≤12 mo, 12 > 12 mo and ≤36 mo, and 10 > 36 mo and ≤12 y,. The median (range) age is 13.5 mo (1.15-112 mo). VCR was quantifiable in all samples, and there was no evidence of contamination in the duplicate samples drawn through the CVC. The mean ± SD AUCβ in the 39 evaluable patients was 54.7 ± 19.8 ng⋅h/mL. As shown in the Table, the AUCβ is similar in patients with a BSA < 0.6 m2 dosed according to the BSA-banded infant dosing table and patients with a BSA ≥0.6 m2 dosed by multiplying their BSA times 1.5 mg/m2 (p = 0.53, Mann Whitney test). Conclusions: The VCR BSA-banded infant dosing table appears to provide uniform VCR exposure for infants and young children compared to conventional BSA-based dosing in older children. The study design and sampling strategy facilitated rapid accrual of a young population and generated more VCR PK data in infants within a year than has been published since the drug was approved in 1963. This study demonstrates the feasibility of systematically studying other anticancer drugs in infants and other special populations to ensure they are receiving safe and effective doses. VCR AUCβ by dosing method. Clinical trial information: NCT05359237 . [Table: see text]

The strength of the shoulder musculature involved with internal rotation and arm extension plays an important role in the overhead throwing motion for baseball athletes, both for throwing-related performance and injury risk. The maintenance of shoulder strength is a high priority for baseball athletes throughout a season; however, little is known in regards to the expected changes in strength throughout a season. To examine pre-post changes in shoulder strength, lower body power, and body composition among collegiate baseball players after the completion of a summer baseball league season. Amateur baseball players (n = 12; age: 20.9 ± 1.0 years.; height: 181.6 ± 5.6 cm; body mass: 86.4 ± 11.1 kg; BMI: 26.0 ± 2.6 kg/m2) participated in the current study. Pre- and post-competitive season, the participants completed shoulder strength assessments and body composition and countermovement vertical jump (CMJ) tests. An upper-body isometric test (athletic shoulder [ASH] test) was used to evaluate shoulder strength for each arm. Each subject completed maximal isometric contractions for both the throwing and non-throwing arms at four separate angles of abduction (180°, ‘I’; 135°, ‘Y’; 90°, ‘T’; and −180°, ‘A’) while lying in a prone position. For shoulder strength, the primary dependent variable of interest was a composite measure that represented the average of the forces produced across all four positions of the ASH test (I, Y, T, A). For the ASH test composite measure, there was a trend toward a significant arm-by-time interaction effect (p = 0.08), as shoulder strength decreased by 9.03% for the throwing arm (ES = 0.72; 95% CI = [−0.27, −0.01]), compared to only 2.03% for the non-throwing arm (ES = 0.15; 95% CI = [−0.16, 0.09]), over the course of the season. The main effects of time (p = 0.16) and arm (p = 0.58) were not significant for the ASH test composite measure. There was no relationship between lower body power and throwing arm strength at baseline (r = 0.20, p = 0.56), and only a non-significant weak relationship at post-test (r = 0.28, p = 0.41). Throughout a season, baseball players may experience reductions in shoulder strength of the throwing arm with minimal changes in shoulder strength in the non-throwing arm.

Aging is a significant risk factor for cardiovascular disease and is known to be associated with an increase in vascular stiffness and decrease in sensitivity to NO mediated vasodilatation. However, the underlying mechanism for these changes in vascular function is unknown. Smooth muscle tone is known to be regulated by the expression and phosphorylation of both nonmuscle (NM) and smooth muscle (SM) myosin. NM and SM phosphorylation is regulated by the activity of myosin light chain kinase (MLCK) and MLC phosphatase. MLC phosphatase is a trimeric enzyme consisting of enzymatic, myosin targeting (MYPT1) and a 20kDa subunit of unknown function. Two isoforms of MYPT1 are produced by alternative mRNA splicing, which differ by the presence or absence of a COOH-terminal leucine zipper (LZ+/-), and the relative expression of LZ+/LZ- MYPT1 determines the sensitivity to NO mediated vasodilatation. We defined NM myosin expression using two-dimensional SDS PAGE and LZ+/LZ- MYPT1 expression using immunoblotting in aortic and tertiary mesenteric smooth muscle from 6mo and 24mo old Fischer344 rats. The data demonstrate that aging is associated with a significant decrease in the expression of both LZ+ MYPT1 and NM myosin. The reduction in LZ+ MYPT1 expression would both decrease the sensitivity to NO mediated smooth muscle dilatation and increase vascular tone, which is a hallmark of the vasculature in aging. On the other hand, the reduction in NM myosin would result in a decrease in vascular tone and could represent a compensatory mechanism to normalize blood pressure during aging. These data demonstrate that there are changes in the expression of smooth muscle regulatory and contractile proteins during aging and these changes in protein expression contribute to molecular mechanism for the decrease in sensitivity to NO mediated vasodilatation as well as the increase in vascular tone or the vascular dysfunction that occurs with aging. Supported by a Mayo CV Prospective Grant (FVB). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Aging is associated with an increased incidence of cardiac dysfunction. We hypothesized that aging associated changes in cardiac regulatory and contractile proteins produce contractile dysfunction. We assessed regulatory and contractile protein expression as well as contractility in left ventricular cardiac muscle from Fischer F-344 rats at 6-, 18-, and 24-month of age. Age-related changes in the expression of β-MHC as well as the expression and phosphorylation of troponin I (TnI) and cardiac myosin binding C protein (MyBP-C) were assessed by Western blot. Aging was associated with an increase in the expression of β-MHC and the phosphorylation of both TnI at Ser23/24 and MyBP-C. Mechanical properties were assessed in Triton-X permeabilized anterior papillary muscle from the left ventricle from both 6- and 24-month old rats. In papillary muscle of 24-month old rats, there was a decrease in maximum Ca2+ activated force, Ca2+ sensitivity of force and the rate constant for force recovery after quick release (ktr). Additionally, cardiomyocytes were isolated from the left ventricle at 6-, 18-, and 24-month of age using a modified Langendorff system. Cardiomyocytes were then loaded with fura-2 AM to measure cytosolic calcium ([Ca2+]cyt) responses to electrical field stimulation (0.5 Hz). [Ca2+]cyt and contractile (sarcomere length shortening) responses to stimulation were simultaneously measured using an IonOptix system. In older cardiomyocytes, the amplitude of evoked [Ca2+]cyt responses was reduced while there was no difference in the kinetics of the [Ca2+]cyt transient. The extent of sarcomere length shortening as well as the rates of both shortening and relaxation were reduced. These results demonstrate that aging is associated with changes in the expression and phosphorylation of contractile and regulatory proteins, which produce changes in cardiac contractility. Supported by a Mayo CV Prospective Grant (FVB). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.