Extracellular Fluid Research Articles

Short-Lived Active Prorenin: Precursor of So-Called Native Prorenin.

The enzymatic activity of the aspartic protease, renin, is critical for its function in blood pressure regulation and sodium homeostasis. Incubation of so-called native prorenin at low pH leads to its activation. After binding to transition-state mimicking renin inhibitors at neutral pH, prorenin attains the active conformation, as indicated by immunosorbent assay using monoclonal antibodies specific for epitopes of the prosegment or the renin body. A comparison of immunosorbent assay with enzyme-kinetic assay revealed the intermediary steps of prorenin auto-activation/inactivation. The kinetically identified intermediary steps of activation/inactivation correspond with the published crystal structures of free renin, free prorenin, and renin in complex with inhibitors. Both renin and activated prorenin exist in 2 forms, α and β. The α form is active, and the α/β quantity ratio is 2.5. The kidney produces renin and prorenin, while the ovarium, placenta, and eye produce inactive prorenin. The production of renin by these organs has never been demonstrated. We propose that the so-called native prorenin in extracellular fluid, including the circulation, is derived, at least partly, from short-lived active prorenin. Its potential paracrine function is discussed.

Acute response to resistance exercise and later development of arm lymphedema in breast cancer survivors: An exploratory follow-up of a randomized cross-over trial

BackgroundIn breast cancer survivors at risk for lymphedema, variation in lymphatic function and arm volume has been observed related to a bout of exercise, with potential for prediction of breast cancer-related arm lymphedema (BCRaL). This novel, exploratory study examined the acute lymphatic response to resistance exercise and later development of BCRaL in women at high risk for BCRaL. MethodsOne year after participation in a cross-over trial evaluating the acute lymphatic response to upper-extremity resistance exercise (low-and heavy-load), participants were assessed for BCRaL (n ​= ​16). The response to exercise was assessed before and after (post, 24- and 72-hrs) each exercise bout as extracellular fluid (L-Dex; bioimpedance spectroscopy (BIS)), interarm volume % difference (IVD; Dual-energy x-ray absorptiometry (DXA)) and symptoms (Numeric rating scale, 0–10 (NRS)). BCRaL at follow-up was defined as presence of one objective indicator (L-Dex >10, change ≥+6.5, IVD >5%) plus one objective or subjective indicator (interarm symptom ≥1 or visual inspection). Descriptive statistics were used to compare the acute response between participants with and without BCRaL at follow-up. ResultsNo trends indicating a similar acute response to exercise was observed in participants who later developed BCRaL (n ​= ​5). There were no observable differences in acute lymphatic response between participants that developed BCRaL and those who did not, both at an individual and group level. ConclusionsFindings from this exploratory study showed no evidence to suggest that the acute response to resistance exercise can predict BCRaL development.

Extracellular volume fraction derived from dual-energy CT: a potential predictor for acute pancreatitis after pancreatoduodenectomy.

To investigate the value of extracellular volume (ECV) fraction and fat fraction (FF) derived from dual- energy CT (DECT) for predicting postpancreatectomy acute pancreatitis (PPAP) after pancreatoduodenectomy (PD). This retrospective study included patients who underwent DECT and PD between April 2022 and September 2022. PPAP was determined according to the International Study Group for Pancreatic Surgery (ISGPS) definition. Iodine concentration (IC) and FF of the pancreatic parenchyma were measured on preoperative DECT. The ECV fraction was calculated from iodine map images of the equilibrium phase. The independent predictors for PPAP were assessed by univariate and multivariable logistic regression analysisand receiver operating characteristic (ROC) curve analysis. Sixty-nine patients were retrospectively enrolled (median age, 60 years; interquartile range, 55-70 years; 47 men). Of these, nine patients (13.0%) developed PPAP. These patients had lower portal venous phase IC, equilibrium phase IC, FF, and ECV fraction, and higher pancreatic parenchymal-to-portal venous phase IC ratio and pancreatic parenchymal-to-equilibrium phase IC ratio, compared with patients without PPAP. After multivariable analysis, ECV fraction was independently associated with PPAP (odd ratio [OR], 0.87; 95% confidence interval [CI]: 0.79, 0.96; p < 0.001), with an area under the curve (AUC) of 0.839 (sensitivity 100.0%, specificity 58.3%). A lower ECV fraction is independently associated with the occurrence of PPAP after PD. ECV fraction may serve as a potential predictor for PPAP after PD. DECT-derived ECV fraction of pancreatic parenchyma is a promising biomarker for surgeons to preoperatively identify patients with higher risk for postpancreatectomy acute pancreatitis after PD and offer selective perioperative management. PPAP is a complication of pancreatic surgery, early identification of higher-risk patients allows for risk mitigation. Lower DECT-derived ECV fraction was independently associated with the occurrence of PPAP after PD. DECT aids in preoperative PAPP risk stratification, allowing for appropriate treatment to minimize complications.

Looking back, moving forward: protein corona of lipid nanoparticles.

Lipid nanoparticles (LNPs) are commonly employed for drug delivery owing to their considerable drug-loading capacity, low toxicity, and excellent biocompatibility. Nevertheless, the formation of protein corona (PC) on their surfaces significantly influences the drug's in vivo fate (such as absorption, distribution, metabolism, and elimination) upon administration. PC denotes the phenomenon wherein one or multiple strata of proteins adhere to the external interface of nanoparticles (NPs) or microparticles within the biological milieu, encompassing ex vivo fluids (e.g., serum-containing culture media) and in vivo fluids (such as blood and tissue fluids). Hence, it is essential to claim the PC formation behaviors and mechanisms on the surface of LNPs. This overview provided a comprehensive examination of crucial aspects related to such issues, encompassing time evolution, controllability, and their subsequent impacts on LNPs. Classical studies of PC generation on the surface of LNPs were additionally integrated, and its decisive role in shaping the in vivo fate of LNPs was explored. The mechanisms underlying PC formation, including the adsorption theory and alteration theory, were introduced to delve into the formation process. Subsequently, the existing experimental outcomes were synthesized to offer insights into the research and application facets of PC, and it was concluded that the manipulation of PC held substantial promise in the realm of targeted delivery.

A Comparison Study on the Metabolites in PC-3, RWPE-1, and Chrysin-Treated PC-3 Cells

Prostate cancer is frequently diagnosed and the leading cause of death in men worldwide. Prostate-specific antigen (PSA) blood tests and biopsies are the primary methods for diagnosing prostate cancer; however, their accuracy is less than 50%. Therefore, there is a need to develop diagnostic tests that minimize patient discomfort during examination and adequate biomarkers that are more accurate, sensitive, and specific for the detection of prostate cancer. This study investigated the application of metabolomics to identify biomarkers in prostate cancer biofluids. In addition, changes in prostate cancer metabolite levels induced by chrysin, a natural anticancer compound, were evaluated and compared with those in non-treated prostate cancer cells. Gas chromatography-mass spectrometry (GC-MS)-based metabolomic profiling was performed to investigate the differences in metabolic alterations among prostate cancer, normal prostate, and chrysin-treated prostate cancer cells. Pairwise comparisons of the extracellular fluid metabolomes were performed using principal component analysis (PCA), partial least squares–discriminant analysis (PLS-DA), and Student’s t-test. The results revealed significantly different patterns among the metabolite groups, including alcohols, amino acids, carboxylic acids, organic acids, sugars, and urea. The RWPE-1- and chrysin-treated PC-3 (PC-3 Chr) cell groups showed similar tendencies for 23 metabolites, while the groups showed significant differences from the PC-3 group. Most amino acids showed higher concentrations in PC-3 cells than in the normal cell line RWPE-1 cells and PC-3 Chr cells. Our results revealed that GC-MS might be an effective diagnostic tool to detect prostate cancer and contribute to finding new tumor markers for prostate cancer as the basis for new ideas.

VENTRICULAR ARRHYTHMIAS IN A UNEXPECTED CARDIAC MAGNETIC RESONANCE

Abstract Background Electrical storm in a widespread inflammation of the myocardium represent a very challenge condition and recognizes a broad spectrum of etiology. Case Presentation A 59–year–old man, without significant prior medical history, came to our attention because, following an emergent hernioplasty procedure, he displayed anterior ST–segment elevation and elevated troponin levels (150.000 ng/L). An echocardiogram revealed an estimated left ventricular ejection fraction (EF) of 39% with anterior hypokinesia. Coronary angiography showed no abnormalities. Cardiac magnetic resonance imaging demonstrated ring–like edema and ring–like late gadolinium enhancement in the left ventricle on T2–weighted and PSIR sequences, with no involvement of the right ventricle. Additionally, there was an increase in extracellular volume. Despite several laboratory tests to investigate infectious or autoimmune causes, the etiology remained inconclusive. To further explore the cause, an endomyocardial biopsy was performed. However, the patient experienced an unstable electrical storm three days later. Management Recurrent ventricular tachycardia (VT) was initially treated with esmolol, amiodarone, and procainamide, but with limited success. Due to VT–induced hemodynamic instability, the patient was sedated with propofol and intubated. Endomyocardial biopsy (EMB) confirmed lymphocytic myocarditis. In light of the hemodynamic instability and refractory electrical storm, the patient was promptly cannulated for veno–arterial extracorporeal membrane oxygenation (VA–ECMO) and started on methylprednisolone. Although there was an apparent resolution of VT, the patient experienced new episodes, necessitating percutaneous stellate ganglion block and an upgraded treatment plan that included mycophenolate mofetil. Given the high burden of arrhythmias, severe ventricular dysfunction, and the lack of response to medications, the patient is now awaiting cardiac transplantation. Conclusion Transmural edema and ring–like late gadolinium enhancement (LGE) in the early phase are predictors of a poor prognosis. In cases of hemodynamic deterioration and refractory electrical storms, it is crucial to promptly initiate mechanical support. Cardiac transplantation remains the sole treatment option for individuals who do not respond to antiarrhythmic and immunosuppressive drugs.

Diagnostic performance of dynamic contrast-enhanced magnetic resonance imaging parameters and serum tumor markers in rectal carcinoma prognosis.

Rectal carcinoma (RC), one of the most common malignancies globally, presents an increasing incidence and mortality year by year, especially among young people, which seriously affects the prognosis and quality of life of patients. At present, dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters and serum carbohydrate antigen 19-9 (CA19-9) and CA125 Levels have been used in clinical practice to evaluate the T stage and differentiation of RC. However, the accuracy of these evaluation modalities still needs further research. This study explores the application and value of these methods in evaluating the T stage and differentiation degree of RC. To analyze the diagnostic performance of DCE-MRI parameters combined with serum tumor markers (TMs) in assessing pathological processes and prognosis of RC patients. A retrospective analysis was performed on 104 RC patients treated at Yantai Yuhuangding Hospital from May 2018 to January 2022. Patients were categorized into stages T1, T2, T3, and T4, depending on their T stage and differentiation degree. In addition, they were assigned to low (L group) and moderate-high differentiation (M + H group) groups based on their differentiation degree. The levels of DCE-MRI parameters and serum CA19-9 and CA125 in different groups of patients were compared. In addition, the value of DCE-MRI parameters [volume transfer constant (Ktrans), rate constant (Kep), and extravascular extracellular volume fraction (Ve) in assessing the differentiation and T staging of RC patients was discussed. Furthermore, the usefulness of DCE-MRI parameters combined with serum CA19-9 and CA125 Levels in the evaluation of RC differentiation and T staging was analyzed. Ktrans, Ve, CA19-9 and CA125 were higher in the high-stage group and L group than in the low-stage group and M + H Group, respectively (P < 0.05). The areas under the curve (AUCs) of the Ktran and Ve parameters were 0.638 and 0.694 in the diagnosis of high and low stages, respectively, and 0.672 and 0.725 in diagnosing moderate-high and low differentiation, respectively. The AUC of DCE-MRI parameters (Ktrans + Ve) in the diagnosis of high and low stages was 0.742, and the AUC in diagnosing moderate-high and low differentiation was 0.769. The AUCs of CA19-9 and CA-125 were 0.773 and 0.802 in the diagnosis of high and low stages, respectively, and 0.834 and 0.796 in diagnosing moderate-high and low differentiation, respectively. Then, we combined DCE-MRI (Ktrans + Ve) parameters with CA19-9 and CA-125 and found that the AUC of DCE-MRI parameters plus serum TMs was 0.836 in the diagnosis of high and low stages and 0.946 in the diagnosis of moderate-high and low differentiation. According to the Delong test, the AUC of DCE-MRI parameters plus serum TMs increased significantly compared with serum TMs alone in the diagnosis of T stage and differentiation degree (P < 0.001). The levels of the DCE-MRI parameters Ktrans and Ve and the serum TMs CA19-9 and CA125 all increase with increasing T stage and decreasing differentiation degree of RC and can be used as indices to evaluate the differentiation degree of RC in clinical practice. Moreover, the combined evaluation of the above indices has a better effect and more obvious clinical value, providing important guiding importance for clinical condition judgment and treatment selection.

Extracellular volume-based scoring system for tracking tumor progression in pancreatic cancer patients receiving intraoperative radiotherapy

ObjectivesTo investigate the value of extracellular volume (ECV) derived from portal-venous phase (PVP) in predicting prognosis in locally advanced pancreatic cancer (LAPC) patients receiving intraoperative radiotherapy (IORT) with initial stable disease (SD) and to construct a risk-scoring system based on ECV and clinical-radiological features.Materials and methodsOne hundred and three patients with LAPC who received IORT demonstrating SD were enrolled and underwent multiphasic contrast-enhanced CT (CECT) before and after IORT. ECV maps were generated from unenhanced and PVP CT images. Clinical and CT imaging features were analyzed. The independent predictors of progression-free survival (PFS) determined by multivariate Cox regression model were used to construct the risk-scoring system. Time-dependent receiver operating characteristic (ROC) curve analysis and the Kaplan–Meier method were used to evaluate the predictive performance of the scoring system.ResultsMultivariable analysis revealed that ECV, rim-enhancement, peripancreatic fat infiltration, and carbohydrate antigen 19-9 (CA19-9) response were significant predictors of PFS (all p < 0.05). Time-dependent ROC of the risk-scoring system showed a satisfactory predictive performance for disease progression with area under the curve (AUC) all above 0.70. High-risk patients (risk score ≥ 2) progress significantly faster than low-risk patients (risk score < 2) (p < 0.001).ConclusionECV derived from PVP of conventional CECT was an independent predictor for progression in LAPC patients assessed as SD after IORT. The scoring system integrating ECV, radiological features, and CA19-9 response can be used as a practical tool for stratifying prognosis in these patients, assisting clinicians in developing an appropriate treatment approach.Critical relevance statementThe scoring system integrating ECV fraction, radiological features, and CA19-9 response can track tumor progression in patients with LAPC receiving IORT, aiding clinicians in choosing individual treatment strategies and improving their prognosis.Key PointsPredicting the progression of LAPC in patients receiving IORT is important.Our ECV-based scoring system can risk stratifying patients with initial SD.Appropriate prognostication can assist clinicians in developing appropriate treatment approaches.Graphical

Bioimpedance and upper limb lymphedema index in the diagnosis of lymphedema in post-mastectomy syndrome

Methods for assessing post-mastectomy edema: bioimpedance and upper extremity lymphedema index (UEL index) are non-invasive, highly sensitive and easily feasible diagnostic methods, suitable for predicting the prospects of surgical treatment and analyzing the dynamics of edema. The purpose of the study was to study UEL index indicators and bioimpedance data at different stages of upper extremity lymphedema. Material and methods. The study included 64 patients with post-mastectomy edema who underwent bioimpedance, measurement of the circumference of the upper extremity and calculation of the UEL index. Results. The upper extremity lymphedema index and bioimpedance parameters (fluid volume in the limb and the ratio of extracellular fluid to total fluid volume) characterizing the liquid component significantly increased at stages II and III of lymphedema in comparison with the control group. a statistically significant correlation was revealed between the upper limb lymphedema index and bioimpedance parameters (R=0.41) and (R=0.49), respectively. Conclusion. Bioimpedance parameters and values of the upper extremity lymphedema index can be interchangeable. The reliability and high sensitivity of these methods for assessing post-mastectomy edema allows us to obtain quantitative criteria for evaluating the liquid component at different stages of lymphedema.

Impact of tafamidis on myocardial function and CMR tissue characteristics in transthyretin amyloid cardiomyopathy.

Tafamidis improves clinical outcomes in transthyretin amyloid cardiomyopathy (ATTR-CM), yet how tafamidis affects cardiac structure and function remains poorly described. This study prospectively analysed the effect of tafamidis on 12-month longitudinal changes in cardiac structure and function by cardiac magnetic resonance (CMR) compared with the natural course of disease in an untreated historic control cohort. ATTR-CM patients underwent CMR at tafamidis initiation and at 12months. Untreated patients with serial CMRs served as reference to compare biventricular function, global longitudinal strain (GLS), LV mass and extracellular volume fraction (ECV). Thirty-six tafamidis-treated (n=35; 97.1% male) and 15 untreated patients (n=14; 93.3% male) with a mean age of 78.3±6.5 and 76.9±6.5, respectively, and comparable baseline characteristics were included. Tafamidis was associated with preserving biventricular function (LVEF (%): 50.5±12 to 50.7±11.5, P=0.87; RVEF (%): 48.2±10.4 to 48.2±9.4, P=0.99) and LV-GLS (-9.6±3.2 to -9.9±2.4%; P=0.595) at 12months, while a significantly reduced RV-function (50.8±7.3 to 44.2±11.6%, P=0.028; P (change over time between groups)=0.032) and numerically worsening LVGLS (-10.9±3.3 to -9.1±2.9%, P=0.097; P (change over time between groups)=0.048) was observed without treatment. LV mass significantly declined with tafamidis (184.7±47.7 to 176.5±44.3g; P=0.011), yet remained unchanged in untreated patients (163.8±47.5 to 171.2±39.7g P=0.356, P (change over time between groups)=0.027). Irrespective of tafamidis, ECV and native T1-mapping did not change significantly from baseline to 12-month follow-up (P>0.05). Compared with untreated ATTR-CM patients, initiation of tafamidis preserved CMR-measured biventricular function and reduced LV mass at 12months. ECV and native T1-mapping did not change significantly comparable to baseline in both groups.

Analysis of the Interaction Effects of Electromagnetic Fields with Major Living Tissues—One Health Concept Numerical Evaluation Strategy

The well-being and sociability of individuals have always been part of modernity. The development of new technologies that meet these aspirations is receiving increasing attention. Thus, strengthening the desired objectives of these technologies and minimizing their undesirable side effects is the subject of growing commitment. The present contribution aims, in this context, to evaluate and analyze the desired and undesirable effects of the interaction of electromagnetic fields with living tissues in general. These are routines based on mathematical modeling reinforcing the expected functions as well as those of control and protection against undesirable effects. These adverse effects correspond to the “One Health” concept, which encompasses the health of animals, plants and humans, as well as ecological disorders created by human activity. First, in this article, the interactions of electromagnetic fields with tissues are analyzed, involving their thermal biological effects of desired and undesired exposures. The roles of blood and sap fluids in bio-affected tissues are then analyzed. Secondly, the equations governing electromagnetics and bio-heat, as well as their coupled solution are studied. Third, the thermal behavior of tissues and the adverse effects of exposure are examined. Next, monitoring and defending the effects of exposures are discussed. This contribution, supported by a review of the literature, illustrates routines for mathematical modeling of the generalized interaction of electromagnetic fields with living tissues.

Disturbance in the protein landscape of cochlear perilymph in an Alzheimer's disease mouse model.

Hearing loss is a pivotal risk factor for dementia. It has recently emerged that a disruption in the intercommunication between the cochlea and brain is a key process in the initiation and progression of this disease. However, whether the cochlear properties can be influenced by pathological signals associated with dementia remains unclear. In this study, using a mouse model of Alzheimer's disease (AD), we investigated the impacts of the AD-like amyloid β (Aβ) pathology in the brain on the cochlea. Despite little detectable change in the age-related shift of the hearing threshold, we observed quantitative and qualitative alterations in the protein profile in perilymph, an extracellular fluid that fills the path of sound waves in the cochlea. Our findings highlight the potential contribution of Aβ pathology in the brain to the disturbance of cochlear homeostasis.

Varicose vein treatment reduces edema not only in the treated legs but also in the entire body.

We explored the connection between varicose vein and edema, by investigating extracellular water ratio (E/T) using bioelectrical impedance analysis. In a prospective cohort study 120 patients underwent varicose vein surgery with extracellular fluid to total body water ratio (E/T) and E/T postop divided by E/Tpreop (E/T ratio) measured using a body composition analyzer. Edema was defined as E/T ≥0.390. Seventy-nine patients received unilateral treatment, while 41 underwent bilateral. p < .05 is statistically significant. Preoperatively, patients exhibited edema (E/T) in the treated leg (0.394 ± 0.009), untreated leg (0.392 ± 0.009), trunk (0.390 ± 0.007), and whole body (0.391 ± 0.007). Postoperatively, E/T decreased across body (p < .05). The lowest E/T ratio was observed in the treated leg (0.991 ± 0.012), followed by the untreated leg (0.994 ± 0.012), the trunk (0.995 ± 0.009), and the whole body (0.994 ± 0.009). E/T ratio of bilateral group were lower than unilateral group (p < .05). Varicose vein contributes to generalized edema, and treatment alleviates edema in the treated leg and the entire body.

Injectable Thermosensitive Gel CH-BPNs-NBP for Effective Periodontitis Treatment through ROS-Scavenging and Jaw Vascular Unit Protection.

Periodontitis, a prevalent inflammatory condition in the oral cavity, is closely associated with oxidative stress-induced tissue damage mediated by excessive reactive oxygen species (ROS) production. The jaw vascular unit (JVU), encompassing both vascular and lymphatic vessels, plays a crucial role in maintaining tissue fluid homeostasis and contributes to the pathological process in inflammatory diseases of the jaw. This study presents a novel approach for treating periodontitis through the development of an injectable thermosensitive gel (CH-BPNs-NBP). The gel formulation incorporates black phosphorus nanosheets (BPNs), which are notable for their ROS-scavenging properties, and dl-3-n-butylphthalide (NBP), a vasodilator that promotes lymphatic vessel function within the JVU. These results demonstrate that the designed thermosensitive gel serve as a controlled release system, delivering BPNs and NBP to the site of inflammation. CH-BPNs-NBP not only protects macrophages and human lymphatic endothelial cells from ROS attack but also promotes M2 polarization and lymphatic function. In in vivo studies, this work observes a significant reduction in inflammation and tissue damage, accompanied by a notable promotion of alveolar bone regeneration. This research introduces a promising therapeutic strategy for periodontitis, leveraging the unique properties of BPNs and NBP within an injectable thermosensitive gel.

Tumor Necrosis Factor-alpha (TNFα) receptor type 1 (TNFR1) activation during severe inflammation; Can it be a therapeutic target in hypervolemic hyponatremia?

Hyponatremia is a life-threatening situation in severe inflammatory disorders. Managing this disorder is seriously hampered because its underlying pathophysiology has remained elusive. An increase in tumor necrosis factor-alpha (TNFα) during systemic inflammation may be involved in this hyponatremic mechanism as it is known that circulating TNFα exerts potent natriuresis via its action on receptor type 1 (TNFR1). Systemic inflammation also induces non-osmotic release of Antidiuretic Hormone (ADH), commonly known as ‘Syndrome of Inappropriate ADH’ (SIADH), that would cause water retention to increase in Extracellular Fluid Volume (ECV). Thus, the inflammation-induced TNFR1 activation and sodium loss coupled with SIADH-induced increases in ECV, would lead to the serious condition of hypervolemic hyponatremia. In this brief review, some experimental evidence will be provided that indicates TNFR1 activation during the inflammatory process can be targeted therapeutically to prevent such critical conditions of hypervolemic hyponatremia. The importance of these co-morbidities also extends to several other clinical scenarios of hyponatremia observed in patients with heart failure, liver disease, and renal disease. Besides the pathophysiological insights, the recognition of the propensity for both antidiuresis and natriuresis during inflammation is critically important in selecting the appropriate intravenous fluid regimens in patients with this disorder such as in the coronavirus disease of 2019 (COVID-19).

Interpretable machine learning based on CT-derived extracellular volume fraction to predict pathological grading of hepatocellular carcinoma.

To develop a non-invasive auxiliary assessment method based on CT-derived extracellular volume (ECV) to predict the pathological grading (PG) of hepatocellular carcinoma (HCC). The study retrospectively analyzed 238 patients who underwent HCC resection surgery between January 2013 and April 2023. Six machine learning algorithms were employed to construct predictive models for HCC PG: logistic regression, extreme gradient boosting, Light Gradient Boosting Machine (LightGBM), random forest, adaptive boosting, and Gaussian naive Bayes. Model performance was evaluated using receiver operating characteristic curve analysis, including area under the curve (AUC), sensitivity, specificity, accuracy, positive predictive value, negative predictive value, and F1 score. Calibration plots were used for visual evaluation of model calibration. Clinical decision curve analysis was performed to assess potential clinical utility by calculating net benefit. 166 patients from Hospital A were allocated to the training set, while 72 patients from Hospital B (constituting 30.25% of the total sample) were assigned to the test set. The model achieved an AUC of 1.000 (95%CI: 1.000-1.000) in the training set and 0.927 (95%CI: 0.837-0.999) in the validation set, respectively. Ultimately, the model achieved an AUC of 0.909 (95%CI: 0.837-0.980) in the test set, with an accuracy of 0.778, sensitivity of 0.906, specificity of 0.789, negative predictive value of 0.556, and F1 score of 0.908. This study successfully developed and validated a non-invasive auxiliary assessment method based on CT-derived ECV to predict the HCC PG, providing important supplementary information for clinical decision-making.

The mechanism of mitochondrial autophagy regulating Clathrin-mediated endocytosis in epilepsy.

The objective of this study is to determine whether inhibition of mitophagy affects seizures through Clathrin-mediated endocytosis (CME). Pentylenetetrazol (PTZ) was intraperitoneally injected daily to establish a chronic PTZ-kindled seizure. The Western blot (WB) was used to compare the differences in Parkin protein expression between the epilepsy group and the control group. Immunofluorescence was used to detect the expression of MitoTracker and LysoTracker. Transferrin-Alexa488 (Tf-A488) was injected into the hippocampus of mice. We evaluated the effect of 3-methyladenine (3-MA) on epilepsy behavior through observation in PTZ-kindled models. The methylated derivative of adenine, known as 3-MA, has been extensively utilized in the field of autophagy research. The transferrin protein is internalized from the extracellular environment into the intracellular space via the CME pathway. Tf-A488 uses a fluorescent marker to track CME. Western blot showed that the expression of Parkin was significantly increased in the PTZ-kindled model (p < 0.05), while 3-MA could reduce the expression (p < 0.05). The fluorescence uptake of MitoTracker and LysoTracker was increased in the primary cultured neurons induced by magnesium-free extracellular fluid (p < 0.05); the fluorescence uptake of Tf-A488 was significantly decreased in the 3-MA group compared with the control group (p < 0.05). Following hippocampal injection of Tf-A488, both the epilepsy group and the 3-MA group exhibited decreased fluorescence uptake, with a more pronounced effect observed in the 3-MA group. Inhibition of mitophagy by 3-MA from day 3 to day 9 progressively exacerbated seizure severity and shortened latency. It is speculated that the aggravation of seizures by 3-MA may be related to the failure to remove damaged mitochondria in time and effectively after inhibiting mitochondrial autophagy, affecting the vesicle endocytosis function of CME and increasing the susceptibility to epilepsy. Abnormal mitophagy was observed in a chronic pentylenetetrazol-induced seizure model and a Mg2+-free-induced spontaneous recurrent epileptiform discharge model. A fluorescent transferrin marker was utilized to track clathrin-mediated endocytosis. Using an autophagy inhibitor (3-methyladenine) on primary cultured neurons, we discovered that inhibition of autophagy led to a reduction in fluorescent transferrin uptake, while impairing clathrin-mediated endocytosis function mediated by mitophagy. Finally, we examined the effects of 3-methyladenine in an animal model of seizures showing that it exacerbated seizure severity. Ultimately, this study provides insights into potential mechanisms through which mitophagy regulates clathrin-mediated endocytosis in epilepsy.

Abstract PO3-12-07: Utility of Volumetric Measurement for Clinical Diagnosis of Breast Cancer-Related Lymphedema

Abstract Background: Early detection of Breast cancer-related lymphedema (BCRL) is crucial since it can significantly reduce the negative impact on a patient’s quality of life after breast cancer treatment. Several objective screening methods have been used in prior studies but have not proven accurate due to a lack of standardization. Bioimpedance spectroscopy (BIS), which assesses tissue resistance to an electric current and converts it into a score to measure interstitial fluid content, has proven to be an accurate tool in diagnosing lymphedema. SOZO® is a BIS device that generates quantitative results in real time and provides a Lymphedema Index (L-Dex) score by measuring the patient's extracellular fluid volume. However, there is a paucity of literature highlighting its clinical applicability. Thus, we aimed to evaluate the clinical utility of SOZO® in diagnosing BCRL in patients undergoing breast cancer surgery. Materials &amp; Methods: A retrospective chart review was carried out of patients who underwent axillary surgery from January 2019 to December 2022. Demographic information such as age, body mass index (BMI), gender, ethnicity, disease pathology, cancer stage, type of axillary surgery, neoadjuvant and adjuvant treatment received was recorded. Patients undergoing sentinel lymph node biopsy (SLNB) and/or axillary lymph node dissection (ALND) were assessed for their preoperative L-Dex score, and they were followed up postoperatively with repeated measurements of their L-Dex score to diagnose lymphedema for a year at 3 months intervals. Clinical lymphedema was defined as those having an absolute L-Dex score of more than +10 and an increase in L-Dex score by 6.5 from the baseline. SOZO® scores measured at each follow-up were compared to their preoperative baseline scores. Results: A total of 200 patients’ data was evaluated whose mean age and BMI were 57.5+10.9 years and 29.6+5.6 kg/m2, respectively. Eighty-five percent of the patients belonged to ethnic minority groups. Furthermore, 84.5% (n=169) of the patients had SLNB, and 15.5% (n=31) had ALND. All the patients included in the study had their preoperative and postoperative quarterly L-Dex scores recorded. Pre- and post-operative L-Dex scores had a mean of -0.20+6.6 and 0.61+6.8, respectively. A total of 20 (10%) patients developed lymphedema without symptoms detected by SOZO®, with 19 (9.5%) resolving at their respective 3-month follow-up and 1 (0.5%) patient with persistent lymphedema at the end of the 24-month follow-up. All 20 patients were treated with a compression sleeve. Of the 20 patients with lymphedema, 4 patients underwent ALND, whereas 16 patients had SLNB. When compared to their preoperative baseline scores, all patients' SOZO® measurements had an absolute score of more than 10 and an increase of 6.5 from their baseline score. Additionally, 21 other patients had an increase in score of 6.5 from their baseline measurements but did not meet the cut-off range of an absolute score of +10. Therefore, we excluded them from the diagnosis of BCRL, and none of these patients later developed any signs of BCRL, such as swelling, pain, or discomfort. Conclusion: SOZO® procedure can accurately detect BCRL. In our study, 1 patient developed clinical lymphedema after undergoing SLNB and was diagnosed using SOZO®. Additionally, 19 patients who were initially diagnosed with lymphedema were later categorized as transient due to the resolution of lymphedema on follow-up. Early identification of transient lymphedema using SOZO® resulted in the prevention of a potentially life-long debilitation in our patients. Moreover, our findings underscore that an increase in SOZO® score from the baseline by &amp;gt; 6.5 with an absolute score of more than +10 should be the threshold to clinically diagnose lymphedema. Future studies with larger sample sizes and longer follow-up duration are necessary to understand better the utility of SOZO® in diagnosing BCRL. Table 1: Baseline characteristics and follow-up data of the patients included in the study. Citation Format: Fardeen Bhimani, Sheldon Feldman, Yu Chen, Anjuli Gupta, Jessica Pastoriza, Areej Shihabi, Maureen McEvoy. Utility of Volumetric Measurement for Clinical Diagnosis of Breast Cancer-Related Lymphedema [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-12-07.

“Interstitial fibrosis is associated with left atrial remodeling and adverse clinical outcomes in selected low-risk patients with hypertrophic cardiomyopathy”

BackgroundCardiovascular magnetic resonance (CMR) extracellular volume (ECV) allows non-invasive detection of myocardial interstitial fibrosis, which may be related to diastolic dysfunction and left atrial (LA) remodeling in hypertrophic cardiomyopathy (HCM). While the prognostic role of LGE is well-established, interstitial fibrosis and LA dysfunction are emerging novel markers in HCM. This study aimed to explore the interaction between interstitial fibrosis by ECV, LA morpho-functional parameters and adverse clinical outcomes in selected low-risk patients with HCM. Methods115 HCM patients and 61 matched controls underwent CMR to identify: i) interstitial fibrosis by ECV in hypertrophied left ventricular LGE-negative remote myocardium (r-ECV); ii) LA indexed maximum (LAVi max) and minimum (LAVi min) volumes, ejection fraction (LA-EF) and strain (reservoir εs, conduit εe and booster εa), by CMR feature-tracking. 2D-echocardiographic assessment of diastolic function was also performed within 6 months from CMR. A composite endpoint including worsening NYHA class, heart failure hospitalization, atrial fibrillation and all-cause death was evaluated at 2.3 years follow-up. HCM patients were divided into two groups, according to r-ECV values of controls. ResultsPatients with r-ECV ≥29% (n = 45) showed larger LA volumes (LAVimax 63 vs. 54 ml/m2, p < 0.001; LAVimin 43 vs. 28 ml/m2, p 〈0001), worse LA function (εs 16 vs. 28%, εe 8 vs. 15%, εa 8 vs. 14%, LA-EF 33 vs. 49%, all p < 0.001) and elevated Nt-proBNP (1115 vs. 382 pg/ml, p = 0.002). LA functional parameters inversely correlated with r-ECV (εs r = −0.54; LA-EF r = −0.46; all p < 0.001) and E/e' (εs r = −0.52, LA-EF r = −0.46; all p < 0.006). r-ECV ≥29% and LAVi min >30 ml/m2 have been identified as possible independent factors associated with the endpoint. ConclusionsIn HCM diffuse interstitial fibrosis detected by increased r-ECV is associated with LA remodeling and emerged as a potential independent predictor of adverse clinical outcomes, on top of the well-known prognostic impact of LGE.

LECs regulate neutrophil clearance through IL-17RC/CMTM4/NF-κB axis at sites of inflammation or infection

The lymphatic system plays a vital role in the regulation of tissue fluid balance and the immune response to inflammation or infection. The effects of lymphatic endothelial cells (LECs) on the regulation of neutrophil migration have not been well studied. In three murine models: imiquimod-induced skin inflammation, S. aureus-induced skin infection, and ligature-induced periodontitis, we show that numerous neutrophils migrate from inflamed or infected tissues to the draining lymph nodes via lymphatic vessels. Moreover, inflamed or infected tissues express a high level of IL-17A and TNF-α, simultaneously with a significant increase in the release of neutrophil attractors, including CXCL1, CXCL2, CXCL3, and CXCL5. Importantly, in vitro stimulation of LECs with IL-17A plus TNF-α synergistically promoted these chemokine secretion. Mechanistically, tetra-transmembrane protein CMTM4 directly binds to IL-17RC in LECs. IL-17A plus TNF-α stimulates CXC chemokine secretion by promoting NF-κB signaling. In contrast, knockdown of CMTM4 abrogates IL-17A plus TNF-α activated NF-κB signaling pathways. Lastly, the local administration of adeno-associated virus for CMTM4 in Prox1-CreERT2 mice, mediating LEC-specific overexpression of CMTM4, promotes the drainage of neutrophils by LECs and alleviates immune pathological responses. Thus, our findings reveal the vital role of LECs-mediated neutrophil attraction and clearance at sites of inflammation or infection.