Background:Septic shock (SS) is deadly. Sepsis-immune response transitions from an endotoxin-sensitive, hyper-inflammatory phase to an endotoxin-tolerant hypo-inflammatory phase. In mice, we implicated sirtuin 2 (SIRT2) for prolonged hypo-inflammation using leukocyte adhesion, the earliest in vivo inflammatory response to cytokine, chemokine, and metabolite stimuli. The role of SIRT2 in human sepsis remains unknown. We hypothesized that (1) peripheral blood mononuclear cells (PBMCs) adhesion response can be used as a physiological biomarker of hypo-inflammation, and (2) SIRT2 regulates the functions of PBMCs and macrophages during the hypo-inflammatory phase of human sepsis.Methods:We stimulated control and SS whole blood and PBMCs ± lipopolysaccharide (LPS) and investigated plasma cytokines, PBMC cell adhesion to intercellular adhesion molecule-1-coated plates, adhesion molecule CD18 activation, SIRT2 expression, and cytokine response. In adhesion-/endotoxin-tolerant PBMCs and THP-1 cells treated ± SIRT2 inhibitor AK-7, we analyzed cell adhesion, CD18 activation, and transmigration ± LPS. In monocyte-derived macrophages from SS versus controls ± AK-7, we analyzed phagocytosis.Results:We found the following: (1) Muted plasma tumor necrosis factor and interleukin-1β-response to LPS in SS versus control (endotoxin tolerance); (2) endotoxin-tolerant SS-PBMCs exhibit high SIRT2 expression, and muted adhesion (adhesion tolerance), CD18 activation, and transmigration with LPS; and (3) SIRT2 inhibitor AK-7 reverses endotoxin and adhesion tolerance in SS-PBMCs via CD18 activation, reverses the defective transmigration of endotoxin-tolerant PBMCs, and improves phagocytosis in monocyte-derived macrophages from SS patients.Conclusions:PBMC adhesion, a physiological biomarker, can be used to detect hypoinflammation. Defective PBMC and macrophage function in SS patients occur via high SIRT2 expression. SIRT2 inhibition is a potential therapeutic strategy for treating sepsis-associated hypo-inflammation.

616: RECTAL ESD IN AN EX VIVO BOVINE LARGE BOWEL MODEL VIA INDEPENDENT RETRACTION WITH GRASPER AND OVERTUBE PASSED THROUGH A TRANSANAL PLATFORM NOTABLY SHORTENS CASE TIME, DECREASES DEEP WALL INJURIES AND IMPROVES RESECTION QUALITY.

1033: ENHANCING GUT EPITHELIAL INTEGRITY AND REDUCING EPITHELIAL INFLAMMATION THROUGH SUPPLEMENTATION OF FECAL METABOLITES, GUIDED BY NOVEL EX VIVO FUNCTIONAL PRIORITIZATION AND TESTING

824: NEW EX VIVO APPROACHES TO QUANTIFY COLON MIGRATING MOTOR COMPLEXES IN MICE: ROUTE OF DRUG DELIVERY MATTERS

188: CONFOCAL LASER ENDOMICROSCOPY CAPTURES LOCAL, FOODINDUCED REACTIONS AT THE LEVEL OF THE DUODENAL MUCOSA IN FUNCTIONAL DYSPEPSIA, THAT CANNOT BE TRANSLATED INTO PERMEABILITY ALTERATIONS OR CHANGES IN MAST CELL ACTIVATION EX VIVO

PO-04-139 IMPROVING LAYER-SPECIFIC ABLATION PRECISION WITH OPTIMISED ELECTRODES: A COMPUTATIONAL AND EX VIVO STUDY

PO-06-069 LEAD PENETRATION IN HYPERTROPHIED IVS USING AN EX VIVO OVINE MODEL: COMPARISON BETWEEN LUMEN LESS LEADS AND STYLET DRIVEN LEADS WITH EMPHASIS ON TORQUE TRANSMISSION

DEVELOPMENT OF AN EX VIVO OSTEOARTHRITIC KNEE MODEL

PO-04-212 LOW IMPEDANCE INFILTRATE WITHIN MYOCARDIUM WILL INCREASE THE RISK OF STEAM POPS ASSOCIATED WITH RADIOFREQUENCY APPLICATIONS: RESULTS FROM A NOVEL EX VIVO BENCH MODEL

AB-499661-002 AN EX VIVO EVALUATION OF AIR INTRUSION INTO PULSED FIELD ABLATION SHEATHS DURING ABLATION AND MAPPING CATHETER INSERTION

PO-03-203 MACHINE LEARNING-BASED PREDICTION MODEL FOR LESION DEPTH IN LONG-DURATION TEMPERATURE-CONTROLLED RADIOFREQUENCY ABLATION: AN EX VIVO STUDY

TOWARDS AN EX VIVO CARTILAGE DAMAGE MODEL TO STUDY CARTILAGE DAMAGE PROGRESSION AND REPAIR

Abstract BACKGROUND To address an intraoperative brain tumor diagnosis by frozen section(FS) which is time-consuming and traumatic, confocal laser endomicroscopy (CLE) has actively been explored as a promising alternative tool. In this study, we aimed to demonstrate that novel CLE image evaluation by a neuropathologist is as effective as frozen section diagnosis for histopathological assessment during brain tumor surgery. MATERIAL AND METHODS Utilizing a novel confocal endomicroscopy (cCeLL) wherein tissues were pretreated with indocyanine green, a prospective multicenter, assessor-blinded interim analysis was conducted at three tertiary medical institutions in the Republic of Korea. Patients newly diagnosed with brain tumors between May 2023 and April 2024 were included. Each tissue sample was divided into three smaller pieces for permanent section analysis, frozen section analysis and cCeLL-Ex vivo imaging. A designated neuropathologist interpreted all cCeLL-Ex vivo images. Statistic evaluation was performed by comparing both frozen section analysis and cCeLL-Ex vivo with permanent H&E diagnosis. The total time from sample preparation to diagnosis was also calculated. RESULTS A total of 274 samples were acquired from 242 patients. The predominant tumor types were meningioma (32.1%), glioma (24.8%) and pituitary adenoma (9.49%). The majority of tissue samples (86.9%) were obtained from the tumor core. Non-diagnostic tissues constituted 4.38% in frozen section and 6.57% in cCeLL-Ex vivo imaging. The diagnostic accuracy of cCeLL-Ex vivo was on par with frozen section analysis, with 96.1% and 96.9%, respectively. Both methods demonstrated comparable diagnostic sensitivity (FS vs cCeLL-Ex vivo: 99.2% vs 98.3%) and specificity(FS vs cCeLL-Ex vivo: 76.0% vs 77.8%). There were no statistically significant differences in diagnostic accuracy between frozen section (FS) and cCeLL imaging for each tumor type. The average number of cCeLL images required for neuropathologic assessment was 15.84, varing based on the tumor type, with a range of 5.05 to 27.8. The mean duration from sample preparation to diagnosis was 8 minutes and 40 seconds in cCeLL-Ex vivo and 24 minutes and 35 seconds in frozen section (p-value < 0.001). CONCLUSION cCeLL-Ex vivo has shown promising tool as an alternative intraoperative brain tumor diagnosis compared to frozen section analysis. Future studies are anticipated to further validate its clinical utility and provide additional evidence supporting the potential of cCeLL imaging in clinical practice.

Introduction. Assessment of changes in the cellular link of innate immunity can enhance the informativeness of approaches to the diagnosis of latent tuberculosis infection. The process of forming neutrophil extracellular traps, NETosis, was described relatively recently, and there is no information in scientific publications about changes in neutrophils’ NETosis ability during preventive chemotherapy in latent tuberculosis infection. Aim. To determine the ability of peripheral blood neutrophils to form extracellular traps ex vivo, and the contents of citrullinated histone H3, PAD4, dynamin–like protein–1, and interleukins 1 and 8 in blood after a 6–month course of preventive chemotherapy for latent tuberculosis infection in children. Materials and Methods. Peripheral blood neutrophils’ ability to form extracellular traps after exposure to a nonspecific antigenic stimulant was studied, as well as the concentrations of citrullinated histone H3, Peptidyl arginine deiminase 4, dynamin–like protein–1, and interleukins 1 and 8 in blood. Group 1 (“Control”) included 30 healthy children with negative tuberculin reaction to tuberculin. Group 2 included 27 children with latent tuberculosis infection, having a positive tuberculosis recombinant allergen test reaction. In this group, all studies were performed at two study points: Point 1 – at the time of initial detection of the infection, point 2 – 6 months after the start of preventive chemotherapy. Results and Discussion. Neutrophils’ ability to form extracellular traps in Group 2 at Point 1 was significantly higher compared to that in the Control Group, with neutrophils more often forming filamentous traps (p=0.0419). After preventive chemotherapy (Point 2), we observed a decrease in the proportion of thread traps (p=0.0357) to the level of the Control Group (p=0.0724). The content of citrullinated histone H3 in the blood of patients from Group 2 at Point 1 was Me=5.60 (Q1=2.80; Q3=12.00) and, statistically, significantly higher (p=0.0002) as compared to the values of the Control Group: Me=1.41 (Q1=0.91; Q3=1.78). In preventive chemotherapy, the analyte concentration decreased: Me=1.20 (Q1=0.90; Q3=1.50), reaching the values that did not differ from those observed in the Control Group. Examining the concentrations of PAD4, dynamin–like protein–1, and interleukins 1 and 8 in blood did not reveal statistically significant differences between the groups studied. Conclusions. In the preventive chemotherapy of latent tuberculosis infection against the background of achieving positive clinical results, normalization of neutrophils’ ability to form extracellular traps was observed, and the proportion of filamentous traps decreased. Decrease in the citrullinated histone H3 content in the blood probably indicated weakening of the intensity of nephrosis. These indicators can be considered as probable and promising markers of the positive results of the chemotherapy of latent tuberculosis infection.

Object: Microwave ablation has been widely used in tumor treatment, and the antenna is a critical component of microwave ablation. We aimed to evaluate a single-slot antenna to generate a small volume ablation zone ([Formula: see text] in adrenal tissue. Methods: A three-dimensional numerical model of the adrenal tissue was built and solved by the Finite Element Method. In the simulation model, the slot antenna was placed between the adrenal gland and fat, and the microwave ablation power and time were adjusted to obtain the target ablation zone. In ex vivo experiments, the length and width of the ablation zone were measured, and the significance of ablation parameters on it was determined using a multi-factorial analysis of variance method. The temperature versus time curves at 3[Formula: see text]mm and 7[Formula: see text]mm from the antenna were plotted to validate the simulation. Results: The simulation results showed that the combination of microwave ablation parameter settings 30[Formula: see text]W/300[Formula: see text]s, 40[Formula: see text]W/180[Formula: see text]s, and 40[Formula: see text]W/300[Formula: see text]s could create ablation zones in the adrenal tissue volumes of [Formula: see text] and [Formula: see text], respectively, with minimal damage (less than [Formula: see text] to the surrounding fat tissue. Both power and heating time significantly affected the length and width of the ablation zone. The temperature rise curves obtained in the simulation and ex vivo experiments were in good agreement. Conclusion: This work shows that utilizing a slot antenna can produce a small volume ablation zone in adrenal tissue for microwave ablation of benign adrenal adenomas.

A rapid high-frequency multiplication protocol is designed for Curcuma pseudomontana J. Graham, belonging to the family Zingiberaceae, an endemic species to the Western Ghats of India. The IUCN Red List of Threatened Taxa mentions this species as vulnerable due to multiple underlying causes. The Plant is extensively used in traditional and tribal medicine. The species has suffered habitat loss due to uncontrolled use for tribal medicine leading to a 30% loss in the last decade. This study is planned with a specific objective to conserve the species, and this is the first-ever report of micropropagation of Curcuma pseudomontana J. Graham using in vitro multiplication. An efficient rapid protocol for Micropropagation is developed using rhizome bud explants. The explants are transferred from MS basal medium onto the MS medium fortified with BAP, KN, TDZ at a varying concentration range. The maximum shoot induction is observed in MS medium enriched with BAP 2mg L-1resulting in 9.66 ±2.08 number of shoots per explant with a shoot length of 6.40 ±0.36cm. The root induction response is studied by aseptically transferring the shoots onto MS medium fortified with NAA, IBA, and IAA at varying concentration. Maximum root length and root number is recorded in MS supplemented with 1- Naphthalene Acetic Acid (NAA) at 0.5 mg L-1. However, a 100 % root induction frequency is observed in all the samples under study. The rooted plantlets are removed from the culture flasks and transferred into hardening media containing 1:1:1 ratio of Sand: Soil: Cocopeat. The hardened plants are healthy and disease-free and showed a 92% survival after acclimatization.

Preface: Understanding knee kinematics is a fundamental prerequisite to address restoration in pathological joints; these performances represent the goal to achieve after the treatment. Experimental activities addressing knee kinematics often involve Motion Capture systems to acquire information, both for in vivo and ex vivo studies. This technique allows a complete analysis of the joint kinematics and is able to provide useful results for the comparison mentioned above. Objectives: The definition of a reproducible and straightforward protocol represents a beneficial factor to improve both reliability and the time required: in this study a new protocol for kinematics experimental activities on ex vivo knee specimens was developed, validated and tested. Methods: Synthetic bones were chosen for the analysis and different Total Knee Arthroplasties models were selected (a Cruciate Retaining, a Posterior Stabilized, a Constrained Condylar Knee and a Rotating Hinge). A dedicated frame was used to support and secure the knee specimens and pair the extensor mechanism to a motor. The Motion Capture System was assembled and paired with dedicated marker-sets to be fixed to the specimens. A post-processing tool was developed to analyze the outputs and was validated with a goniometer. A series of force-driven tasks were defined, implemented and run in the motor system for all the different prosthesis configurations and kinematics output were analyzed, comparing the outputs with the expected results. Results: The validation of the system returned satisfying results in terms of correspondence between the angles imposed and the ones measured, with an average error below [Formula: see text] and a standard deviation below [Formula: see text] for each kind of rotation. The results from the different testing were coherent with the type of specimens and prostheses tested. Conclusions: This study proved that the protocol and testing set-up developed for knee kinematics in vitro analysis are able to provide reliable and coherent data, as proven by the post-processing validation and by the testing campaign on synthetic specimens.

MP05-05 ANTIMICROBIAL AND ANTIBIOFILM PROPERTIES OF CHITOSAN: AN EX VIVO STUDY ON KIDNEY STONES

MP01-03 XENO-FREE PEPTIDE-FUNCTIONALIZED BIOINKS IMPROVE EX VIVO CULTURE OF HUMAN TESTICULAR TISSUES

Cytokine production by ex vivo (EV)-stimulated leukocytes is commonly used to gauge immune function and frequently proposed to guide immunomodulatory therapy. However, whether EV cytokine production capacity accurately reflects the in vivo (IV) immune status is largely unknown. We investigated relationships between EV monocyte cytokine responses and IV cytokine responses in a large cohort of healthy volunteers using a highly standardized IV model of short-lived LPS-induced systemic inflammation, which captures hallmarks of both hyperinflammation and immunological tolerance. Therefore, 110 healthy volunteers were intravenously challenged with 1 ng/kg LPS twice: on day 0 to determine the extent of the IV (hyper)inflammatory response and on day 7 to determine the degree of IV endotoxin tolerance. Baseline EV monocyte cytokine production capacity was assessed prior to LPS administration. Short-term and long-term EV tolerance was assessed in monocytes isolated 4 h and 7 days after LPS administration, respectively. No robust correlations were observed between baseline EV cytokine production capacity and IV cytokine responses following LPS administration. However, highly robust inverse correlations were observed between IV cytokine responses and EV cytokine responses of monocytes isolated 4 h after IV LPS administration. No correlations between IV and EV tolerance were found. In conclusion, attenuated EV cytokine production capacity reflects ongoing IV inflammation rather than immune suppression. Results of EV assays should be interpreted with caution at the risk of improper use of immuno­stimulatory drugs.