Experimental Model Research Articles

A Hollowed‐Out Heterometallic Cluster for Catalytic Knoevenagel Condensation

Lanthanide‐containing clusters are synthetically Lanthanide‐containing clusters are synthetically challenging and with significant chemical and materials applications. Herein, two isostructural heterometallic clusters of the formula (NO3)12@[Ln132Ni78(OH)292(IDA)48(CH3COO)96(NO3)12(H2O)78]Cl44·xH2O·yCH3OH (IDA = iminodiacetate; Ln = Gd 1, x = 110, y = 0; Ln = Eu 2, x = 95, y = 40) were obtained via co‐hydrolysis of Ln3+ (Gd3+ or Eu3+) and Ni2+ in the presence of iminodiacetate (IDA). Crystallographic studies show that each features a truncated tetrahedral core of Ln132Ni78 within which a void of 5.5 Å in diameter; connecting the central cage and its exterior are four trumpet‐like passageways surface‐decorated with dinuclear units of [Gd(μ3‐OH)2Gd]. Mass spectroscopic analyses indicate that both clusters maintained their structural integrity in aqueous solution, with cryo‐electron microscopy providing the most convincing visual evidence in support of the cluster's solution stability. Size‐selective Knoevenagel condensation, believed to occur in the passageways on the basis of experimental and molecular modeling results, was achieved in the presence of 1. The application of 1 as a uniquely structured molecular reactor and a recyclable heterogeneous catalyst was further illustrated by the one‐pot three‐component synthesis of biologically and pharmaceutically significant 4H‐pyran derivatives.

Design, analysis, and demonstration of the COAST guidewire robot with middle tube rotation for endovascular interventions.

Minimally invasive procedures for endovascular interventions involve manual navigation of a guidewire. Endovascular interventions encompassing highly tortuous vessels would benefit from guidewires which exhibit higher dexterity. This paper introduces a version of the COAST (COaxially Aligned STeerable) guidewire system capable of exhibiting higher dexterity. The system presented in this paper consists of three coaxially aligned tubes with a tendon to actuate the middle tube. Furthermore, it is possible to independently rotate the middle tube with respect to the outer tube. This variation enables the guidewire to achieve curvature in different planes while avoiding rotation of the entire structure. We also present the simulated stability of the guidewire with different outer tube geometries and experimentally validate the model. Experimental analysis and modeling of the kinematic behavior of the system is presented. A model to calculate the curvature vs. tendon stroke relationship for the optimal notch geometry is presented with an average RMSE of 0.16mm. A control strategy addressing the snapping instabilities to ensure reliable operation is discussed. A custom phantom vessel and an aortic arch phantom model were used to demonstrate the ability of the system to safely navigate through tortuous pathways without exhibiting these elastic instabilities.

Serum High Mobility Group Box 1 (HMGB1) Protein Levels and Cognitive Function in Epilepsy Patients: A Cross-Sectional Study

Background: Epilepsy is a neurological disease with a high incidence rate. Cognitive decline is one of the consequences of recurrent seizures. Neuroinflammation is closely related to the development of epilepsy and cognitive impairment. An increase in the expression and translocation of High Mobility Group Box 1 (HMGB1) from the nucleus to the extracellular space has been observed in epilepsy patients and experimental animal models. This study aimed to investigate the relationship between serum HMGB1 levels and cognitive function in epilepsy patients. Methods: This cross-sectional observational study involved 45 epilepsy patients. Cognitive function was assessed using the Indonesian version of the Montreal Cognitive Assessment (MoCA-Ina), and serum HMGB1 levels were measured using the ELISA technique. The relationship between cognitive function and HMGB1 levels was analyzed using the Kruskal-Wallis test, with a significance level set at p < 0.05. Results: The mean age of the participants was 28.5 years, with a higher proportion of females. The mean serum HMGB1 level was 22.6 ng/ml. No significant relationship was found between serum HMGB1 levels and cognitive function in epilepsy patients (p = 0.188). Conclusion: Serum HMGB1 protein levels were not associated with cognitive function in this sample of epilepsy patients.

Performance of repair pre-damaged RC columns using steel straps tensioning techniques (SSTT) confinement: experimental data and modelling

PurposeA model that extends study parameters to predict repaired column behaviour is efficient. Three-dimensional nonlinear finite element models were created in ABAQUS to simulate steel strap confinement with inclusion of pre-damaged levels.Design/methodology/approachExperimental and analytical studies demonstrate that restored reinforced concrete (RC) columns usually crush at mid-height under axial compressions. Numerical models verified RC column load-deformation. Although some specimens have considerable column stiffness differences, a numerical model based on statistical analysis matches experimental test results.FindingsIt shows that, finite element model exhibited a tendency to overestimate the stiffness of the columns, with an average absolute error (AAE) of 23.1%. The validation results indicate that the AAE values for strength and ductility were 15.1% and 12.3%. It has been demonstrated that the combination of strength and ductility is capable of yielding predictions with an error rate of approximately 20%. A parametric study focused on finite element model-predicted load bearing capacity reduction.Originality/valueA numerical analysis employing finite element modelling has been formulated to investigate the behaviour of confined columns. The model underwent validation through comparison with the experimental results. The validated model is utilised to perform additional parametric investigations on the confined column.

Abstract 4138661: Targeting Arginase I Alleviates Cardiomyopathy

Introduction: Emerging data have shown that pathological cardiac fibrosis and heart failure is driven by recruitment of CD4 + T cells to injured heart tissue. Systemic deletion of CD4 + T cells or splenectomy has been shown to attenuate CD4 + T cell heart infiltration and inflammation. We engineered cargo-less nanoparticles using a biocompatible and biodegradable polymer that target splenic macrophages to overexpress arginase I, leading to local depletion of L-arginine, an amino acid crucial for CD4 + T cell activation and expansion. Hypothesis: Cargo-less nanoparticles attenuate CD4 + T cell activation, expansion, and heart infiltration in experimental models of cardiomyopathy by regulating cross talk between macrophages and CD4 + T cells via L-arginine depletion in the spleen. Methods: Spleen-targeting, cargo-less nanoparticles were synthesized from poly(L-lactide-co-glycolide) (PLLGA) and administered to murine and human macrophages in vitro. Arginase I expression and activity were assessed via Western blotting and arginase activity assay. Epigenetic modulation was analyzed using Western blotting and CHIP-seq. Conditioned media was collected to culture CFSE-labeled T cells to assess proliferation. The nanoparticles were administered to mouse heart failure models induced by isoproterenol or angiotensin II and phenylephrine. Immune cell composition in mouse spleens and hearts was investigated by flow cytometry. Cardiac function was assessed by echocardiography and heart fibrosis was examined via immunohistochemistry and Western blotting. Results: Primary murine macrophages treated with our nanoparticles exhibited a dose-dependent T cell suppression in vitro. This effect was abrogated when an arginase inhibitor was administered together with the nanoparticles. The nanoparticles upregulated arginase I protein expression and arginase activity by increasing histone lactylation. In vivo testing with mouse heart injury models showed that the nanoparticles restored levels of effector and regulatory T cells in injured mice to non-injured levels. Additionally, the nanoparticles reduced cardiac fibrosis and restored ejection fraction. Furthermore, Western blotting of heart tissue lysate revealed that the nanoparticles downregulated the TGFb and p-SMAD signaling pathway. Conclusion: Collectively, these findings highlight a novel therapeutic strategy for heart failure, addressing the gap of fibrosis treatment by targeting upstream immunological pathways.

IMMU-66. PHYSIOLOGICALLY RELEVANT MURINE GLIOMA MODELS THAT REPRESENT GBM HETEROGENEITY AND ENABLE THE NEXT GENERATION OF DISCOVERY AND THERAPY EFFICACY STUDIES

Abstract To transform cancer drug development pipelines and gain a deeper mechanistic understanding of cancer: immune interactions, we desperately need better experimental models that faithfully recapitulate the cellular heterogeneity, complex and dynamic cell:cell interactions, and therapy responses in humans. To address this need, we developed and characterized a cohort of five new mouse glioma models in the C57BL6/j background. These transplantable tumorsphere models were derived from spontaneous gliomas that formed in genetically engineered mouse models with different oncogenic drivers, including EGFRviii, PDGFA, PTEN, p53, and NF1 mutations. They show a range of responses to standard of care (TMZ+IR) similar to GBM patients and all are resistant, to immune checkpoint inhibitors, anti-PD1+CTLA4, treatment, unlike the GL261 model and similar to GBM patients. We deeply characterized each model, including immune phenotyping and single-cell RNA-sequencing analyses. We also performed a cross-species comparison of human and mouse GBM and stromal cell phenotypes at the single-cell level. Our results show that new mouse models recapitulate the heterogeneity of glioma cell states observed in individual patients and, importantly, also the complex and immune suppressive TME. We demonstrate at the single-cell level that glioma-associated T and myeloid cell types are molecularly similar and conserved across species. Leveraging these data sets and experimental models, we are testing now novel immunotherapy targets for GBM.

Experimental and Numerical Analysis of PIP Slip Joint Subjected to Bending

Detachable circular hollow sections (CHSs) offer an innovative solution to tackle the complexities of installation, maintenance, upgrades, and repairs in offshore monopile systems, particularly in challenging environments with limited access. As an alternative to traditional tubular joints, the PIP slip joint presents advantages in terms of ease of installation, time efficiency, and reduced susceptibility to failure. This study conducts an experimental investigation on PIP (Pile-in-Pile) slip joints under pure bending conditions, accompanied by comprehensive numerical analyses to examine the relationship between section slenderness, contact properties, and structural performance. The results highlight a strong correlation between force-displacement curves and include a comparison of compressive and tensile strain values for both experimental and numerical models. The experimental and numerical models showed strong agreement across all results, demonstrating the robustness of the findings. Additionally, numerical models were utilized to investigate various D/t ratios, revealing insights into the normalized moment, rotational capacity, and the impact of local buckling and contact mechanics. Furthermore, a comparison of these findings with established code guidelines, such as Eurocode and AISC-LRFD, has been conducted and reviewed in the context of this study. From analysis, it was found that the rise in the D/t ratio prompted a transformation in the buckling mode, which substantially altered the rotational ratio. This shift indicates the importance of understanding how these variables interact in engineering applications. These findings significantly enhance the understanding of PIP slip joints and emphasize their potential as a compelling alternative for offshore wind turbine support structures.

EPCO-20. MUTANT IDH INHIBITORS INDUCE LINEAGE DIFFERENTIATION IN IDH-MUTANT OLIGODENDROGLIOMA

Abstract IDH-mutant gliomas exhibit variable responses to mutant-IDH inhibitor (IDHi) therapy; yet, the molecular mechanisms underlying these responses remain poorly understood. Here, we investigate the cellular underpinnings of response by leveraging single cell/nuclei RNA-sequencing of on-treatment IDH-mutant oligodendroglioma tumor samples resected from three patients who benefited clinically from treatment. We integrate these findings with single cell and bulk RNA-seq data from independent cohorts and experimental models. We find that IDHi treatment promotes robust differentiation towards the astrocytic lineage, accompanied by stem-like cell depletion and reduced proliferation. Notably, NOTCH1 mutations are associated with impaired astrocytic differentiation, potentially negatively impacting response to IDHi. This study unveils the differentiating effects of IDHi on oligodendroglioma cellular hierarchies and identifies a potential genetic marker for optimizing patient selection. Paper was recently published in Cancer Cell (10.1016/j.ccell.2024.03.008).

TMOD-16. ZUCLOPENTHIXOL REDUCES ACTIVITY-DEPENDENT GLIOBLASTOMA PROLIFERATION

Abstract A major challenge in modeling glioblastoma in the laboratory is the complex microenvironment in which tumors evolve in humans. The varied architecture and immune privilege of the brain limits the external validity of many experiments performed in modern cell biology laboratories. Organotypic human cortical slices present an opportunity to model glioblastoma and test the effect of drugs against glioma in ex-vivo human tissue. Cortical slice cultures maintain the cellular organization of the human brain, more closely approximating glioblastoma proliferation in patients. In this study, we test the effect zuclopenthixol, a repurposed antipsychotic inhibitor of glioblastoma-induced neuronal hyperexcitability, on the proliferation of glioblastoma cells in an organotypic human cortical slice culture. Primary patient-derived glioblastoma cultures were established, and human cortical tissues were emersed in oxygenated ACSF agarose gel before preparing 250 µm thick slices. Slices were either exogenously seeded with glioblastoma cells or stained for endogenous tumor infiltration. Slices with either endogenous or exogenous seeding were then treated with zuclopenthixol or regular media change and cultured for 10 days. Proliferation was measured with Ki67 staining and quantified via automated pixel summation using the Pillow library in Python. 0.1 µM zuclopenthixol treated slices had significantly lower proliferation index in both the endogenous tumor condition (0.04 vs 0.30, P < 0.05) and the exogenous seeding condition (0.0013 vs 0.028, P = 0.033). Reduced tissue integrity was observed beginning day 8 of culture, as tissue surrounding tumor seeding sites eroded. Here, we model glioblastoma proliferation in live human tissue and quantify the anti-proliferative effect of zuclopenthixol. We show that zuclopenthixol treatment significantly reduced the proliferation index. Our experimental model allowed the optimization of organotypic human cortical slice cultures for immunofluorescence studies and live-cell imaging.

THE ROLE OF INTRACELLULAR SIGNALING PATHWAYS IN THE DEVELOPMENT OF TROPHIC PATHOLOGIES OF THE LOWER EXTREMITIES AND THEIR REGENERATION UNDER TYPE 2 DIABETES (PART 1)

Introduction. This review article addresses the critical issue of the development and regeneration of chronic trophic ulcers in the context of type 2 diabetes. This pathological process is associated with inhibited cell proliferation, impaired differentiation of various cell types, and disrupted mechanisms that regulate cell death. An analysis of recent scientific literature also highlights the involvement of key intracellular signaling pathways in the development of chronic ulcerative pathologies of the lower extremities, as observed in both experimental animal models and patients with type II diabetes. Despite advancements, this issue remains insufficiently explored in both theory and practice, underscoring its ongoing relevance. The aim of this study is to identify the roles of key signaling pathways—transforming growth factor β (TGF-β), phosphatidylinositol 3-kinase/serine-threonine kinase (PI3K/Akt), and Wnt/β-catenin—in the inflammatory response, regenerative mechanisms, and healing processes of soft tissue damage and trophic ulcers in experimental animals and patients with type II diabetes. Materials and Methods. This study is based on an analysis of current scientific literature that addresses this topic. Results. It has been found out that changes in the content and activity of key molecules of signaling pathways lead to disruption of carbohydrate homeostasis and the occurrence of structural and functional dysfunction in damaged tissues against the background of type II diabetes. These include TGF-β, PI3K, Akt and β-catenin. Analysis of experimental data demonstrated that both under the conditions of type II diabetes development and in the occurrence of chronic ulcers of the lower extremities, against the background of this endocrine disease, there is an increase in the level of TGF-β. At the same time the activity of the PI3K/Akt signaling pathway in the above-mentioned studied groups was reduced. The relationship between the development of type II diabetes and the Wnt/β-catenin signaling pathway has been established. Suppression of its activity was accompanied by impaired regeneration of chronic trophic ulcers in type II diabetes. Conclusion. Thus, the mechanism of type II diabetes and chronic peptic ulcer disease, in the same pathology, is associated with a impaired activity of signaling cascades. This concerns the following cellular systems such as TGF-β, PI3K/Akt and Wnt/β-catenin. They can be considered as potential therapeutic targets for the development of newest methods for the treatment of chronic trophic ulcers in type II diabetes in order to accelerate the recovery process of volumetric tissue damage of the lower extremities.

Targeting SPP1-orchestrated neutrophil extracellular traps-dominant pre-metastatic niche reduced HCC lung metastasis.

The mechanisms by which tumor-derived factors remodel the microenvironment of target organs to facilitate cancer metastasis, especially organ-specific metastasis, remains obscure. Our previous studies have demonstrated that SPP1 plays a key role in promoting metastasis of hepatocellular carcinoma (HCC). However, the functional roles and mechanisms of tumor-derived SPP1 in shaping the pre-metastatic niche (PMN) and promoting lung-specific metastasis are unclear. Orthotopic metastasis models, experimental metastasis models, CyTOF and flow cytometry were conducted to explore the function of SPP1 in shaping neutrophil-dominant PMN and promoting HCC lung metastasis. The main source of CXCL1 in lung tissues was investigated via fluorescence activated cell sorting and immunofluorescence staining. The expression of neutrophils and neutrophil extracellular traps (NETs) markers was detected in the lung metastatic lesions of HCC patients and mouse lung specimens. The therapeutic significance was explored via in vivo DNase I and CXCR2 inhibitor assays. SPP1 promoted HCC lung colonization and metastasis by modifying pulmonary PMN in various murine models, and plasma SPP1 levels were closely associated with lung metastasis in HCC patients. Mechanistically, SPP1 binded to CD44 on lung alveolar epithelial cells to produce CXCL1, thereby attracting and forming neutrophil-abundant PMN in the lung. The recruited neutrophils were activated by SPP1 and then formed NETs-dominant PMN to trap the disseminated tumor cells and promote metastatic colonization. Moreover, early intervention of SPP1-orchestrated PMN by co-targeting the CXCL1-CXCR2 axis and NETs formation could efficiently inhibit the lung metastasis of HCC. Our study illustrates that HCC-lung host cell-neutrophil interactions play important roles in PMN formation and SPP1-induced HCC lung metastasis. Early intervention in SPP1-orchestrated PMN via CXCR2 inhibitor and DNase I is a potential therapeutic strategy to combat HCC lung metastasis.

Preventive Effects of Polyprenols from the Needles of Aabies sibirica under the Influence of Adverse Factors

Currently, biologically active substances of natural origin are widely used as preventative agents. The search and development of new drugs for the prevention and correction of nonspecific disorders of the body’s resistance to adverse effects in environment continues. A preclinic assessment of the effectiveness of polyprenols from Siberian fir Abies sibirica was carried out when used prophylactically for two weeks. It has been shown that the effect of polyprenols is manifested by antioxidant, anabolic activity and stimulation of hematopoiesis in an experimental model of combined poisoning with carbendazim and X-ray irradiation.

Thermoregulation and survival during sepsis: insights from the cecal ligation and puncture experimental model

BackgroundSepsis remains a major global health concern due to its high prevalence and mortality. Changes in body temperature (Tb), such as hypothermia or fever, are diagnostic indicators and play a crucial role in the pathophysiology of sepsis. This study aims to characterize the thermoregulatory mechanisms during sepsis using the cecal ligation and puncture (CLP) model and explore how sepsis severity and ambient temperature (Ta) influence Tb regulation and mortality. Rats were subjected to mild or severe sepsis by CLP while housed at thermoneutral (28 °C) or subthermoneutral (22 °C) Ta, and their Tb was monitored for 12 h. Blood and hypothalamus were collected for cytokines and prostaglandin E2 (PGE2) analysis.ResultsAt 28 °C, febrile response magnitude correlated with sepsis severity and inflammatory response, with tail vasoconstriction as the primary heat retention mechanism. At 22 °C, Tb was maintained during mild sepsis but dropped during severe sepsis, linked to reduced UCP1 expression in brown adipose tissue and less effective vasoconstriction. Despite differences in thermoregulatory responses, both Ta conditions induced a persistent inflammatory response and increased hypothalamic PGE2 production. Notably, mortality in severe sepsis was significantly higher at 28 °C (80%) compared to 22 °C (0%).ConclusionsOur findings reveal that ambient temperature and the inflammatory burden critically influence thermoregulation and survival during early sepsis. These results emphasize the importance of considering environmental factors in preclinical sepsis studies. Although rodents in experimental settings are often adapted to cold environments, these conditions may not fully translate to human sepsis, where cold adaptation is rare. Thus, researchers should carefully consider these variables when designing experiments and interpreting translational implications.Graphical Graphical representation of the thermoregulatory and inflammatory responses to mild and severe sepsis in rats housed at thermoneutral (28 °C) and subthermoneutral (22 °C) ambient temperatures (Ta). The model highlights distinct body temperature outcomes: fever and hypothermia. At thermoneutral Ta, severe sepsis induces a high fever, associated with increased hypothalamic PGE2, cytokine levels, and mortality, while mild sepsis leads to a moderate fever. In contrast, at subthermoneutral Ta, severe sepsis results in hypothermia with decreased UCP1 expression and lower mortality, whereas mild sepsis maintains normal body temperature. The impact of Ta on sepsis severity, thermoregulatory mechanisms, and survival is emphasized.

Exosomes activate hippocampal microglia in atrial fibrillation through long-distance heart–brain communication

BackgroundThere is growing evidence that atrial fibrillation (AF) is a risk factor for cognitive impairment (CI) and dementia in the presence or absence of stroke. The purpose of this study was to explore the mechanism of CI caused by AF.MethodsEighteen male canines were randomly divided into a sham group, a pacing group, and a pacing + GW4869 group. An experimental model of AF was established by rapid atrial pacing (450 beats/min) for 2 weeks, and the sham group received pacemaker implantation without atrial pacing. The GW4869 group received an intravenous GW4869 injection (0.3 mg/kg, once a day) during pacing. All canines were locally injected with Ad-CD63-RFP in epicardial adipose tissue (EAT) to trace the exosomes. Ultracentrifugation was employed to isolate EAT-derived exosomes, followed by RNA sequencing and quantitative real-time PCR (qRT-PCR) to assess RNA in both exosomes and hippocampal tissue. The miRanda database was used to predict the targeting relationships between miRNA and mRNA, which were further validated by luciferase reporter assays. Western blot analysis was conducted to detect exosomal markers (CD63, CD81, TSG101) in EAT exosomes, while immunofluorescence was used to detect Ad-CD63-RFP signals in both EAT and hippocampal tissues, as well as microglial activation marker IBA-1. To further explore the effects of exosomes on microglial cells, in vitro experiments using brain microvascular endothelial cells (bEnd3) and microglial cells (BV2) were conducted. IBA-1 expression and RNA levels in BV2 cells were analyzed by immunofluorescence and qRT-PCR, respectively.ResultsAfter 14 days of pacing of the canine atrium, compared to the sham group, both the pacing and GW4869 groups exhibited an increased number of AF inductions, along with prolonged AF duration. The fluorescence intensity of Ad-CD63-RFP and the microglial activation marker IBA-1 were markedly greater in the hippocampus. RNA sequencing showed that the differentially expressed gene cfa-miR-22e in EAT exosomes was upregulated, and its target gene IL33 was downregulated in the hippocampus. qRT-PCR showed that the levels of cfa-miR-22e were increased in both EAT exosomes and the hippocampus, while the expression of IL-33, a target of cfa-miR-22e, was decreased in the hippocampus. The administration of GW4869 abolished these effects. The in vitro results from bEnd3 and BV2 cell experiments were consistent with the conclusions drawn from the in vivo studies.ConclusionOur study indicated that the exosomes secreted by EAT in canines with AF can penetrate the BBB and activate microglia in the hippocampus through the cfa-miR-22e/IL33 signalling pathway.

Evaluation of Xihuang Pill in inducing pyroptosis in glioma cells through modulation of miR-21-5p.

This study aims to elucidate the mechanism by which Xihuang Pill induces pyroptosis in glioma cells via the regulation of miR-21-5p. Human glioma cell lines U-87 and LN-229 were used as experimental models to assess the effects of Xihuang Pill on glioma pyroptosis. Cells were incubated with Xihuang Pill extract at concentrations of 7.5, 15, and 30µg/mL for 24h, alongside transfection with miR-21-5p mimic, an overexpression vector for STAT3, or incubation with 50µg/mL of the STAT3 activator Colivelin for 4h. Cell viability was measured using the CCK-8 assay, apoptosis was detected by flow cytometry, and expression levels of p-STAT3/STAT3 and pyroptosis-related proteins were determined by Western Blot. Additionally, cleaved caspase-1 was assessed by immunofluorescence, miR-21-5p expression by qRT-PCR, and STAT3 binding to the miR-21-5p promoter region by ChIP and dual-luciferase reporter assays. Results showed that Xihuang Pill significantly reduced cell viability, increased apoptosis, and upregulated the expression of pyroptosis-related proteins such as NLRP3, IL-1β, cleaved caspase-1, and GSDMD-N, while reducing p-STAT3/STAT3 and miR-21-5p levels (P < 0.05). Xihuang Pill inhibited STAT3 activation, which modulated miR-21-5p expression by binding to its promoter region. Co-transfection with miR-21-5p mimic reversed the effect of Xihuang Pill on glioma pyroptosis (P < 0.05). In conclusion, Xihuang Pill promotes glioma cell pyroptosis through the STAT3/miR-21-5p pathway.

Pullout Capacity of Piles in Unsaturated High Plasticity Clayey Soil: An Experimental Model Study

Pullout Capacity of Piles in Unsaturated High Plasticity Clayey Soil: An Experimental Model Study

Exploiting blood-based biomarkers to align preclinical models with human traumatic brain injury.

Rodent models are important research tools for studying the pathophysiology of traumatic brain injury (TBI) and developing new therapeutic interventions for this devastating neurological disorder. However, the failure rate for the translation of drugs from animal testing to human treatments for TBI is 100%. While there are several potential explanations for this, previous clinical trials have relied on extrapolation from preclinical studies for critical design considerations, including drug dose optimization, post-injury drug treatment initiation and duration. Incorporating clinically relevant biomarkers in preclinical studies may provide an opportunity to calibrate preclinical models to identical (or similar) measurements in humans, link to human TBI biomechanics and pathophysiology, and guide therapeutic decisions. To support this translational goal, we conducted a systematic literature review of preclinical TBI studies in rodents measuring blood levels of clinically used GFAP, UCH-L1, NfL, t-Tau, or p-Tau, published in PubMed/EMBASE up to April 10th, 2024. Although many factors influence clinical TBI outcomes, many of those cannot routinely be assessed in rodent studies (e.g., ICP monitoring), thus we focused on blood biomarkers' temporal trajectories and discuss our findings in the context of the latest clinical TBI biomarker data. Out of the 805 original preclinical studies, 74 met the inclusion criteria, with a median quality score of 5 (25th-75th percentiles: 4-7) on the CAMARADES checklist. GFAP was measured in 43 studies, UCH-L1 in 21, NfL in 20, t-Tau in 19, and p-Tau in seven. Data in rodent models indicate that all biomarkers exhibited injury severity-dependent elevations with distinct temporal profiles. GFAP and UCH-L1 peaked within the first day after TBI (30- and 4-fold increases, respectively, in moderate-to-severe TBI versus sham) with the highest levels observed in the contusion TBI model. NfL peaked within days (18-fold increase) and remained elevated up to 6 months post-injury. GFAP and NfL show a pharmacodynamic response in 64.7% and 60%, respectively, of studies evaluating neuroprotective therapies in preclinical models. However, GFAP's rapid decline post-injury may limit its utility for understanding the response to new therapeutics beyond the hyperacute phase after experimental TBI. Furthermore, as in humans, subacute NfL levels inform on chronic white matter loss after TBI. t-Tau and p-Tau levels increased over weeks after TBI (up to 6- and 16-fold, respectively); however, their relationship with underlying neurodegeneration has yet to be addressed. Further investigation into biomarker levels in the subacute and chronic phases after TBI will be needed to fully understand the pathomechanisms underpinning blood biomarkers' trajectories and select the most suitable experimental model to optimally relate preclinical mechanistic studies to clinical observations in humans. This new approach could accelerate the translation of neuroprotective treatments from laboratory experiments to real-world clinical practices.

Oral Transport, Penetration, and Aspiration in PD: Insights from a RCT on STN + SNr Stimulation.

Dysphagia is frequent and detrimental in advanced Parkinson's disease (PD) and does not respond to standard treatments. Experimental models suggested that pathological overactivity of the substantia nigra pars reticulata (SNr) may hinder oral contributions to swallowing. Here, we hypothesized that the combined stimulation of subthalamic nucleus (STN) and SNr improves measures of dysphagia after eight weeks of active treatment. We enrolled 20 PD patients with dysphagia and deep brain stimulation (DBS). Patients were assessed in 'medication on' and 'STN' stimulation at baseline (V1) and then were randomized 1:1 to 'STN' or 'STN + SNr' stimulation. In addition, patients of both groups received swallowing therapy as a standard of care. The primary endpoint was the change in Penetration-Aspiration Scale (PAS) at eight-week follow-up (V2) with respect to the baseline (V1) under the hypothesis, that 'STN + SNr' was superior to 'STN'. We obtained further secondary endpoints on oral preparation, transport, pharyngeal phase, penetration, and aspiration. PAS change from V1 to V2 was not significantly different between groups (p = 0.221). When considering all patients for secondary analyses, we found that the entire study cohort showed better PAS scores at V2 compared to V1 irrespective from DBS treatment allocation (p = 0.0156). Both STN and STN + SNr treatments were safe. 'STN + SNr' stimulation was not superior compared to standard 'STN' stimulation both on PAS and the secondary endpoints. We found that the entire study cohort improved dysphagia after eight weeks, which presumably mirrors the effect of continued swallowing therapy and the increased patient attention on swallowing.

Physical justification of the safety of using a surgical laser with a wavelength of 445nm during stapedoplasty

Abstract Introduction. Surgical lasers with different wavelengths are used in the surgical treatment of patients with otosclerosis. There are undoubted advantages of using surgical lasers during stapedoplasty at its various stages. At the same time, there is a risk of negative consequences for the structures of the inner ear due to the transition of light energy into thermal energy. Currently, the search for modern optimal surgical lasers for stapedoplasty continues. Aim ofthe study. To substantiate the safety of using a laser beam with a wavelength of 445nm during stapedoplasty using an experimental physical model. Materials and methods. Together with physicists from the Russian Engineering Club LLC, a physical experimental model was created to theoretically substantiate the use of a surgical laser with a wavelength of 445nm during stapedoplasty at its various stages. Results. Based on the physical calculations carried out during our study, we came to important conclusions regarding the effect of laser radiation on the structures of the inner ear during the stapedoplasty process. It was found that even if the value of the parasitic (damaging) radiation energy is 10 W (maximum value) with an average pulse duration used for perforation of the footplate of the stirrup is 0.15 s, then its effect will not lead to any significant thermal effect on the perilymph. Conclusions. The obtained data serve as a basis for further research and improvement of laser technologies in the field of otosurgery. As part of our study, we anticipate the need for additional histological analysis based on the results obtained. Despite encouraging findings regarding the safety of parasitic laser radiation in the context of thermal exposure to perilymph, histological examination represents an important next step for a deeper understanding of structural changes in the tissues of the inner ear.

Closing the Design-Make-Test-Analyze Loop: Interplay between Experiments and Predictions Drives PROTACs Bioavailability.

The drug development landscape is expanding to include drug modalities such as PROteolysis-TArgeting Chimeras (PROTACs) and peptides, offering possibilities for previously intractable biological targets. However, with their size and chemical nature, they diverge from established frameworks for the prediction of oral bioavailability. This evolution to larger and more complex molecules necessitates new methodologies and prediction models to continuously expand on bioavailability guidelines. We describe the high-capacity adoption of two chromatographic physicochemical assays and their application for iterative compound optimization to achieve oral bioavailability. We further describe how these data underpin the continuous refinement of internal machine learning models, which guide compound synthesis decisions in the molecular design phase. Based on data for a set of 691 PROTACs, and two project examples, we confirm a sweet spot for oral bioavailability at log D values higher than the norm for small molecules and show how experimental data and prediction models synergize to effectively drive chemistry optimization.