Citations

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.

Abstract Aims To conduct a pooled analysis of Phase 3 trials investigating the efficacy and safety of inclisiran across glycaemic and body mass index (BMI) strata. Materials and Methods Participants were randomized 1:1 to receive 300 mg inclisiran sodium or placebo twice yearly, after initial and 3‐month doses up to 18 months, with background oral lipid‐lowering therapy. Analyses were stratified by glycaemic status (normoglycaemia, prediabetes, and diabetes) or BMI (<25, ≥25 to <30, ≥30 to <35, and ≥35 kg/m 2 ). Co‐primary endpoints were percentage and time‐adjusted percentage change in low‐density lipoprotein (LDL) cholesterol from baseline. Safety was also assessed. Results Baseline characteristics were balanced between treatment arms and across strata. Percent LDL cholesterol change (placebo‐corrected) with inclisiran from baseline to Day 510 ranged from −47.6% to −51.9% and from −48.8% to −54.4% across glycaemic/BMI strata, respectively. Similarly, time‐adjusted percentage changes after Day 90 and up to Day 540 ranged from −46.8% to −52.0% and from −48.6% to −53.3% across glycaemic/BMI strata, respectively. Inclisiran led to significant reductions in proprotein convertase subtilisin/kexin type 9 and other atherogenic lipids and lipoproteins versus placebo across the glycaemic/BMI strata. The proportions of individuals achieving LDL cholesterol thresholds of <1.8 mmol/L and <1.4 mmol/L with inclisiran increased with increasing glycaemic and BMI strata. Across the glycaemic/BMI strata, a higher proportion of individuals had mild/moderate treatment‐emergent adverse events (TEAEs) at the injection site with inclisiran (2.8%–7.7%) versus placebo (0.2%–2.1%). Conclusion Inclisiran provided substantial and sustained LDL cholesterol lowering across glycaemic/BMI strata, with a modest excess of transient mild‐to‐moderate TEAEs at the injection site.

Abstract Introduction Geriatric emergency department (ED) guidelines emphasize timely identification of delirium. This article updates previous diagnostic accuracy systematic reviews of history, physical examination, laboratory testing, and ED screening instruments for the diagnosis of delirium as well as test–treatment thresholds for ED delirium screening. Methods We conducted a systematic review to quantify the diagnostic accuracy of approaches to identify delirium. Studies were included if they described adults aged 60 or older evaluated in the ED setting with an index test for delirium compared with an acceptable criterion standard for delirium. Data were extracted and studies were reviewed for risk of bias. When appropriate, we conducted a meta‐analysis and estimated delirium screening thresholds. Results Full‐text review was performed on 55 studies and 27 were included in the current analysis. No studies were identified exploring the accuracy of findings on history or laboratory analysis. While two studies reported clinicians accurately rule in delirium, clinician gestalt is inadequate to rule out delirium. We report meta‐analysis on three studies that quantified the accuracy of the 4 A's Test (4AT) to rule in (pooled positive likelihood ratio [LR+] 7.5, 95% confidence interval [CI] 2.7–20.7) and rule out (pooled negative likelihood ratio [LR−] 0.18, 95% CI 0.09–0.34) delirium. We also conducted meta‐analysis of two studies that quantified the accuracy of the Abbreviated Mental Test‐4 (AMT‐4) and found that the pooled LR+ (4.3, 95% CI 2.4–7.8) was lower than that observed for the 4AT, but the pooled LR− (0.22, 95% CI 0.05–1) was similar. Based on one study the Confusion Assessment Method for the Intensive Care Unit (CAM‐ICU) is the superior instrument to rule in delirium. The calculated test threshold is 2% and the treatment threshold is 11%. Conclusions The quantitative accuracy of history and physical examination to identify ED delirium is virtually unexplored. The 4AT has the largest quantity of ED‐based research. Other screening instruments may more accurately rule in or rule out delirium. If the goal is to rule in delirium then the CAM‐ICU or brief CAM or modified CAM for the ED are superior instruments, although the accuracy of these screening tools are based on single‐center studies. To rule out delirium, the Delirium Triage Screen is superior based on one single‐center study.

Abstract Background: In breast cancer, the spatial relationship between immune and tumor cells is increasingly recognized as critical in determining the efficacy of neoadjuvant therapy (NAT). This study investigated how the distribution of immune cells, particularly CD8+ T cells, relative to tumor cells affects treatment outcomes. Methods: Biopsies from 104 breast cancer patients were examined, both pre- and post-NAT, using multiplex immunohistochemistry (mIHC). This study focused on the density and distribution of CD8+ T cells, CD68+ macrophages, FoxP3+ regulatory T cells, and other immune markers. Results: The spatial proximity of CD8+ T cells within 20 µm of cancer cells (N20-CD8+T) was strongly correlated with improved clinical outcomes across diverse tumor subtypes and NAT regimens. A significant post-NAT decrease in CD4+, CD68+, and FoxP3+ cells highlights notable shifts in the tumor immune landscape. A noteworthy finding was the positive correlation between CXCL9 expression and N20-CD8+T cells, suggesting a mechanism for immune cell recruitment and interaction within the tumor microenvironment. These results highlight the complex interplay among NAT, immune cell modifications, and patient outcomes. Conclusions: This study revealed that the proximity of N20-CD8+ T cells to tumor cells is consistently associated with favorable NAT outcomes, transcending tumor subtypes, and treatment differences. This highlights the potential of immune cell dynamics, especially CD8+ T cells, as predictive biomarkers for therapeutic responses in breast cancer, underscoring their vital role in tumor immunity.