Search Results (4,119)

Neuroinflammation is increasingly recognized as a key modulator of therapeutic response and adverse events in Alzheimer’s disease (AD), especially during anti-amyloid-β (Aβ) monoclonal antibody (Aβ-mAb) treatment. We applied longitudinal translocator protein (TSPO) positron emission tomography (PET) to evaluate TSPO-associated neuroinflammatory responses to chronic Aβ-mAb therapy and their modulation by the peroxisome proliferator-activated receptor γ (PPARγ) agonist pioglitazone. App^NL-G-F knock-in mice underwent TSPO-PET and Aβ-PET imaging at 5, 7.5, and 10 months of age across four treatment arms: placebo, Aβ-mAb, pioglitazone, and combination therapy. TSPO-PET detected early and progressive neuroinflammatory responses to Aβ-mAb that appeared lower with pioglitazone co-treatment. Both mono- and combination therapy were associated with altered temporal and spatial dynamics of the TSPO-PET signal. In addition, we applied a previously validated microglia desynchronization index based on TSPO-PET connectivity, which captured individual variation in regional TSPO-PET organization and correlated with cognitive performance. Together, TSPO-PET and its regional synchronicity can quantify longitudinal, region-specific treatment effects, which may help differentiate harmful from adaptive neuroinflammatory responses. These findings highlight the potential of TSPO-PET as a stratification biomarker to optimize therapeutic interventions. TSPO-PET therefore enables in vivo tracking of treatment-associated neuroinflammatory responses during anti-Aβ immunotherapy and provides a non-invasive framework for evaluating combination strategies targeting amyloid pathology and immune regulation in AD. Full article

Computed tomography (CT) is used to support the diagnosis of equine temporomandibular joint (TMJ) disease; however, its diagnostic accuracy remains unclear. This study aimed to evaluate the relationship between CT findings and histopathological manifestations of osteoarthritis (OA) in equine TMJs. A total of 82 TMJs were CT-imaged, sampled, grouped into age-related and OA-related groups, and analyzed for frequency distributions, correlations, and CT-based TMJ OA diagnosis. CT findings were observed in 79% of joints, including ‘CT anatomical variations’ considering to reflect age-related remodeling. Only 50% of joints showed co-occurrence of CT findings and histopathological manifestations of OA, confirming that not all CT findings are indicative of disease. Including all CT findings in the CT-based diagnosis of TMJ OA yielded a specificity of 0.41 (95% CI: 0.26–0.58), suggesting a high rate of false-positive diagnoses. Excluding all ‘CT anatomical variations’ resulted in a sensitivity of 0.56 (95% CI: 0.40–0.72), indicating a substantial number of false-negative diagnoses. However, inclusion of specific ‘CT anatomical variation’—subchondral bone cysts—into the studied CT-based diagnosis increased sensitivity to 0.79 (95% CI: 0.62 to 0.89) while maintaining high specificity of 0.92 (95% CI: 0.80–0.98). Including this subset of CT findings in the diagnosis of equine TMJ OA may improve the accuracy of disease detection; however, the clinical relevance of the present cadaver investigation needs to be confirmed in in vivo studies. Full article

Age-related macular degeneration (AMD) is a leading cause of irreversible vision loss worldwide. Geographic atrophy (GA) is an advanced, currently incurable stage of non-exudative AMD and is characterized by progressive atrophy of the retinal pigment epithelium and outer retina, resulting in substantial visual impairment. Optical coherence tomography (OCT) has revolutionized the diagnosis and monitoring of AMD by enabling in vivo visualization of retinal microstructure and identification of imaging biomarkers associated with progression to late-stage disease. Improved understanding of these lesions may clarify disease pathogenesis and inform the development of new therapeutic strategies and clinical trial endpoints. This review summarizes OCT-based biomarkers reported as predictors of progression to late atrophic forms of AMD, with emphasis on early atrophic changes that precede GA. Full article

Background: Traumatic brain injury (TBI) affects millions of individuals annually and remains a major global cause of neurological disability and death. Tau protein hyperphosphorylation, particularly in its cis conformation, is a major pathological hallmark contributing to neurodegeneration following TBI. Single-chain variable fragments (scFvs), despite their diagnostic potential, suffer from rapid renal clearance and short circulation half-lives, which limit their in vivo performance. PEGylation is therefore employed to prolong systemic circulation and improve the pharmacokinetic behavior of scFvs, enabling more effective brain retention and target engagement. Methods: In this study, we utilized a previously validated anti-cis p-tau scFv antibody fragment, radiolabeled with technetium-99m tricarbonyl (^99mTc(CO)₃), as a diagnostic tracer to detect tau pathology in TBI rat models. The antibody was conjugated with polyethylene glycol (PEG, 20 kDa); PEGylation efficiency was determined by quantifying the products on SDS-PAGE, and the products were subsequently radiolabeled. Results: Radiochemical purity (RCP) was ~95.4% for the non-PEGylated tracer (^99mTc-AININ20) and ~92.7% for the PEGylated form (^99mTc-AININ20-PEG), with both showing >90% radiochemical purity consistently. Upon systemic administration, PEGylated scFv was able to cross the blood–brain barrier (BBB) and selectively accumulated in injured regions, as confirmed by single-photon emission computed tomography (SPECT) imaging. Both PEGylated and non-PEGylated scFv tracers showed significantly higher brain uptake in TBI rats compared to healthy controls (p < 0.0001). At 24 h, the PEGylated form exhibited a significantly higher brain signal than the non-PEGylated version (p < 0.0001), indicating improved tracer retention. Biodistribution analysis at 2 h post-injection showed significantly reduced renal clearance for the PEGylated tracer and increased hepatic uptake compared to the non-PEGylated form. At 24 h, in vivo imaging confirmed sustained brain retention, highlighting improved pharmacokinetics and imaging potential. Conclusions: These results support PEGylated scFv as a promising SPECT imaging agent for early detection of tauopathy in TBI, offering enhanced brain retention and improved pharmacokinetics. Full article

Preclinical multimodal imaging is widely applied in small animal models for longitudinal studies of human diseases. Beyond murine systems, cost-effective and ethically sustainable models such as the chicken embryo and its chorioallantoic membrane are gaining increasing interest in accordance with the 3Rs principles. This study evaluated the feasibility of using both high-frequency ultrasound and magnetic resonance imaging for the non-invasive longitudinal monitoring of chicken embryo development in ovo. Fifty fertilized eggs were incubated under controlled conditions and examined up to embryonic day 14. High-frequency ultrasound (15–71 MHz) enabled real-time imaging and quantitative assessment of superficial structures, including cranial biometry and limb growth, while magnetic resonance imaging (7T) provided high-resolution three-dimensional visualization of internal organs and extraembryonic compartments. Together, these modalities allowed the progressive identification of key anatomical structures from ED5 onward, with HFUS enabling earlier linear measurements and MRI facilitating detailed anatomical and volumetric evaluation. The integration of these techniques allowed the generation of a developmental imaging timeline and quantitative reference dataset of normal embryogenesis. This multimodal approach represents a promising strategy for in vivo developmental studies, offering a robust baseline to characterize structural alterations induced by experimental conditions. Moreover, the use of the chicken embryo model provides significant ethical and economic advantages, supporting its application in preclinical research and imaging-based studies. Full article

Background/Objectives: The integration of Artificial Intelligence (AI) into clinical workflows raises critical questions regarding decision-making responsibility, as fully autonomous systems inevitably carry a margin of error that can be fatal in high-stakes fields like surgery. This study addresses this challenge by evaluating a “Human-in-the-Loop” (HITL) workflow, using intraoperative Optical Coherence Tomography (OCT) for glioma detection. We aimed to determine if integrating Machine Learning (ML)-generated segmentation maps with human contextual analysis resolves the tension between automation and clinical responsibility, yielding superior diagnostic reliability compared to structural or quantitative imaging alone. Methods: We retrospectively analyzed 86 intraoperative OCT scans from 27 patients. Five neurosurgeons blindly assessed the data across three progressive levels of processing: (1) structural scans, (2) physics-based parametric maps, and (3) SVM-based generated segmentation maps. Crucially, the HITL inference performance on segmentation maps was benchmarked against “models-only” inference pipeline: a SVM and a state-of-the-art multimodal reasoning model, Gemini 3.1 Pro. To evaluate interpretability and the operator’s ability to confidently exercise their authority, we measured inter-rater consistency alongside diagnostic performance. Results: The results demonstrate that, while quantitative parametric maps improved Global Accuracy (87% [95% CI: 82–92%]) compared to structural scans (80% [95% CI: 73–86%]), they suffered from an “interpretability gap,” resulting in a moderate inter-rater consistency of 0.68 [95% CI: 0.59–0.78]. In contrast, the HITL approach using segmentation maps maximized consensus to 0.98 [95% CI: 0.95–1.00] and achieved the highest performance (Accuracy 94% [95% CI: 88–98%] and Sensitivity 98% [95% CI: 92–100%]). Compared to the standalone models, the HITL approach significantly outperformed the SVM baseline (Accuracy 84% [95% CI: 81–87%]; Sensitivity 83% [95% CI: 78–88%]). Furthermore, it surpassed the SOTA Gemini 3.1 Pro model (Accuracy 90% [95% CI: 83–95%]; Sensitivity 86% [95% CI: 74–95%]). While the HITL sensitivity demonstrated a definitive and statistically significant edge over the Gemini model, the accuracy improvement fell just slightly short of undisputed statistical significance due to overlapping confidence intervals. Conclusions: By utilizing their clinical domain knowledge of tumor invasion patterns and topological priors, surgeons effectively filtered algorithmic noise—overriding ML errors in 69% (9 out of 13) false positive cases that models alone could not resolve. This demonstrates exactly how and where HITL optimally utilizes human contextual intelligence to outperform autonomous “models-only” pipelines, confirming a human-ML synergy that augments the objectivity of machine learning with human domain knowledge. This paradigm ensures that the ultimate responsibility for diagnostic inference remains safely and practically in human hands. Open Data Initiative: To ensure essential reproducibility, enable independent multi-center validation and support open science, all examples of intraoperative in vivo OCT brain scans used in this study are made publicly available. To the best of our knowledge, this represents the first open-access data of its kind globally. Full article

Background/objectives: This study presents a mechanistic assessment of an anti-HSPG2 monoclonal antibody (AM6) as an antibody–drug conjugate (ADC) carrier in vitro. Methods: Using live-cell confocal imaging with pathway inhibitors, we qualitatively characterized AM6 internalization and trafficking and compared linker/payload configurations for intracellular delivery and in vitro cytotoxicity. Results: AM6 exhibited rapid cellular entry in MDA-MB-231-LM2 cells, with contributions from clathrin-mediated endocytosis and macropinocytosis, followed by accumulation in endo-lysosomal compartments. Consistent with these trafficking observations, AM6 ADCs bearing cleavable linkers and a potent payload (MMAE) produced more pronounced antiproliferative effects in MDA-MB-231-LM2 and other HSPG2-positive tumor cells than non-cleavable constructs, whereas doxorubicin-based ADCs showed limited activity and greater aggregation risk. Conclusions: Overall, the data inform linker/payload selection and highlight considerations for future work, including quantitative internalization, antigen-negative or knockdown controls, and in vivo pharmacology. Full article

The increasing fragmentation of plastic debris into nanosized particles represents a threat to freshwater ecosystems, yet the biological effects of nanoplastics (NPs) on freshwater invertebrates remain poorly understood. This study investigated tissue distribution, cellular effects and immune responses following acute exposure to polyethylene terephthalate nanoplastics (PET-NPs) in the freshwater gastropod Pomacea canaliculata, a species of high ecological relevance and physiological resilience. Adult snails were injected with PET-NPs at 5 or 10 mg/L and sampled after 24 and 72 h. PET-NPs accumulation in the anterior and posterior kidneys was assessed by fluorescence imaging and tissue morphology was evaluated. Stress- and inflammation-related genes (Pc-Heat Shock Protein (HSP)70, Pc-HSP90 and Pc-Allograft inflammatory factor 1) expression was quantified by RT-qPCR. PET-NPs uptake and phagocytic activity were analyzed in circulating hemocytes in vivo and ex vivo. PET-NPs were accumulated in renal tissues, persisting up to 72 h without histopathological alterations. Gene expression analyses revealed non-linear and dose/time-dependent responses. Hemocytes of different morphologies internalized PET-NPs in a dose-dependent manner and showed intercellular particle transfer. Overall, acute PET-NP exposure determines rapid immune handling and tissue sequestration with limited short-term physiological impact, underscoring the potential involvement of immune processes in NPs fate and highlighting the need for chronic exposure studies. Full article

Background: Patellar motion trajectory (PMT) is a key kinematic parameter for evaluating patellofemoral joint (PFJ) stability, but traditional static imaging indices are unable to capture the dynamic six-degrees-of-freedom (6-DOF) characteristics of patellar motion throughout the entire knee flexion–extension cycle. Four-dimensional computed tomography (4D-CT) facilitates in vivo dynamic imaging of the PFJ, while the systematic classification of PMT in asymptomatic populations has remained underexplored. Methods: A retrospective cross-sectional study was performed on 64 asymptomatic and functionally normal knees that underwent 4D-CT dynamic scanning from March 2021 to December 2025. Patellar 6-DOF kinematic data during 0° to 90° of knee flexion–extension were extracted through manifold optimization, automatic segmentation, and spatial registration. Following standardization of the motion cycle, unsupervised K-means clustering was employed to classify PMT phenotypes, with nonparametric tests used to analyze intergroup kinematic differences and evaluate clustering quality. Results: Three distinct PMT types were identified based on clustering validity indices, including a silhouette score of 0.381, a Davies-Bouldin index of 0.916, and a Calinski–Harabasz index of 44.06: Type 1 (7.81%, 35.11 ± 6.56 mm), Type 2 (56.25%, 15.67 ± 6.59 mm), and Type 3 (35.94%, 2.82 ± 2.41 mm). Lateral translation (Tx) served as the dominant determinant for PMT typing (p < 0.001), whereas non-lateral DOF parameters exhibited no consistent intergroup differences. Postural DOFs exhibited coupled fluctuations with Tx but had no independent stratification effect. Traditional static imaging parameters demonstrated no consistent correlation with these dynamic subtypes. Conclusions: Functionally asymptomatic knees exhibited three in vivo patellar 6-DOF motion trajectory phenotypes dominated by lateral translation amplitude. This 4D-CT-based typing framework provides a dynamic kinematic baseline for PFJ stability evaluation and lays a foundation for individualized optimization of ligament reconstruction and pathophysiological research of patellofemoral disorders. Full article

Background/Objectives: Advanced renal cell carcinoma (aRCC) remains incurable, with no established optimal sequence of targeted therapies due to interpatient heterogeneity and acquired resistance. We developed a luciferase-enabled patient-derived orthotopic xenograft (PDOX) avatar platform to evaluate sequential targeted therapies in individualized aRCC models that recapitulate tumor architecture, proliferation, angiogenesis, metastasis, and PD-L1 expression. Methods: Tumor specimens from two renal cell carcinoma (RCC) patients were expanded subcutaneously in NOD/SCID mice, transduced with luciferase/red fluorescent protein (Luc/RFP), and orthotopically implanted into mouse kidneys (KiCa-Pt58: sarcomatoid RCC, pT3aN1M1, Fuhrman grade 4; KiCa-Pt118: clear cell RCC with sarcomatoid component, pT3aNxM0, Fuhrman grade 4, respectively). Tumor growth and metastasis were monitored weekly by bioluminescence imaging (BLI). Mice were randomized into vehicle control or four sequential treatment groups (Everolimus→Sunitinib [E→S], Sunitinib→Everolimus [S→E], Pazopanib→Sunitinib [P→S], Pazopanib→Everolimus [P→E]). Drugs were administered orally three times weekly until resistance (>200% BLI increase), with one switch. At necropsy, tumor burden, ex vivo BLI metastasis, weights, H&E histology, and immunohistochemistry (Ki67, CD44, CD31, PD-L1) were assessed. Results: Two independent experiments were performed. In dosing optimization, PDOX tumors recapitulated parental histology and proliferative indices, mirroring patient trajectories. KiCa-Pt58 (metastatic sarcomatoid RCC; deceased 1-month post-nephrectomy) showed aggressive features: rapid engraftment at low doses, early growth (week 2), and lung metastases in 78% of mice (sacrifice day 34), reflecting a fulminant course. KiCa-Pt118 (non-metastatic; patient recurrence-free >8 years post nephrectomy) exhibited indolent behavior: delayed engraftment requiring higher doses plus lymph node stromal (HK) support, slower growth (week 4), no metastases, and later sacrifice (day 78), consistent with remission. In sequential therapy evaluation, for KiCa-Pt58, P→E yielded greatest reductions in tumor weight (p < 0.01), lung metastases (p < 0.01), Ki67+ proliferation, CD31+ angiogenesis, and PD-L1 expression versus control; E→S and S→E were also effective. For KiCa-Pt118, S→E and P→E reduced tumor burden (p < 0.01) and Ki67⁺ proliferation; S→E lowered CD31 and PD-L1. Conclusions: This RCC PDOX platform faithfully preserves patient-specific biology—including metastatic propensity, engraftment efficiency, growth kinetics, and stromal dependency—while enabling real-time evaluation of sequential targeted therapies. Given the limited number of models tested, these findings provide proof-of-concept for individualized treatment exploration in advanced RCC and support future investigation of rational combinations with immune checkpoint blockade in humanized or immunocompetent systems. Full article

Macrophages are among the earliest responders to tissue injury and remain associated with the wound throughout the healing process. Calcium (Ca²⁺) signaling regulates many immune cell behaviors, yet its role in macrophage responses to injury in vivo remains poorly defined. Here, we used transgenic zebrafish (Danio rerio) and Danionella cerebrum lines that specifically express the genetically encoded Ca²⁺ indicator, GCaMP, in macrophages. Live confocal imaging was used to monitor macrophage Ca²⁺ dynamics during the early wound response. We found that injury triggers macrophage recruitment to the wound site, where cells exhibit robust and repetitive intracellular Ca²⁺ transients that persist for several hours. Pharmacological perturbation revealed that endoplasmic reticulum Ca²⁺ stores contribute to sustaining these transients, while additional Ca²⁺ sources likely participate in macrophage Ca²⁺ signaling in vivo. Functionally, these Ca²⁺ transients do not appear to be required for chemotaxis, phagocytosis, or TNFα activation during the early stages of wound healing. Together, these findings uncover a previously uncharacterized macrophage Ca²⁺ signaling behavior and highlight the complexity of Ca²⁺ regulation during tissue injury responses in vivo. Full article

Peripheral nerve blocks can effectively reduce the use of general anesthesia and opioids in situations where robust pain management is critical, such as severe extremity trauma and hip, femur, and knee surgeries. Despite these benefits, nerve blocks are underutilized due to the high skill required to accurately insert a needle and safely deliver local anesthetic. To overcome this challenge, ultrasound image guidance enabled by artificial intelligence (AI) offers a semi-automated solution for regional anesthesia delivery by non-specialists. As a first step towards realizing an integrated platform for AI-guided nerve blocks, the main objective of this study is to develop and characterize deep learning algorithms to interpret anatomical landmarks on ultrasound images in real time and identify aimpoints for needle placement. Our AI system was trained on over 55,000 images from 20 porcine models and demonstrated an average area under the precision–recall curve of 0.92 (SD = 0.03) for in vivo landmark detection in the femoral nerve region. In prospective live animal testing, aimpoint identification had a 98.3% success rate with an average time of 40.5 s (SD = 33.5). Future work will focus on integrated testing with handheld robotics towards a more accessible method for delivering regional anesthesia in settings from point of injury to medical transport to hospitals. Full article

High-temperature stress severely limits the growth, development, and productivity of tomatoes. Understanding the molecular mechanisms underlying its thermotolerance is crucial for breeding heat-resistant varieties. This study employed a stepwise experimental strategy to systematically elucidate the role of the chlorophyll a/b-binding protein SlCAB3 in tomato thermotolerance. First, a high-temperature responsive transcription factor, SlDREBA4, previously identified in our lab, was used in a yeast two-hybrid screen to identify potential interacting proteins, including SlCAB3. The interaction between SlDREBA4 and SlCAB3 was further validated using tobacco in vivo luciferase complementation imaging (LCI) and in vitro pull-down assays. Subsequently, the expression patterns of SlCAB3 under heat stress were analyzed, and its biological function was further evaluated through overexpression, gene silencing, and knockout experiments. Additionally, reactive oxygen species (ROS) accumulation, antioxidant enzyme activities, chlorophyll content, and the expression of stress-responsive genes were measured to comprehensively assess their physiological and molecular regulatory roles. The results indicate that SlCAB3 encodes a typical chlorophyll a/b-binding protein and is rapidly induced by heat stress. Overexpression of SlCAB3 significantly enhances plant thermotolerance, evidenced by reduced heat damage, increased chlorophyll content, decreased ROS accumulation, elevated antioxidant enzyme activities, and upregulation of antioxidant-related genes. Conversely, silencing SlCAB3 produces opposite effects. Moreover, co-expression of SlCAB3 with SlDREBA4 further improves thermotolerance, accompanied by enhanced expression of heat shock protein-related and antioxidant-related genes. In conclusion, SlCAB3 is a positive regulator of tomato thermotolerance, and the interaction module formed with SlDREBA4 may collectively enhance heat resistance by strengthening antioxidant defense and heat stress response mechanisms. Full article

Background: Directional hemispherical reflectance (DHR) is a precise method for evaluating skin reflectance and is widely used in dermatological, photobiological, and cosmetic or pharmaceutical research. Reflectance measurements may support emissivity-related interpretation, particularly in the infrared range, being influenced by chromophore content, epidermal structure, and physiological factors such as hydration, pigmentation, and surface heterogeneity. However, most in vivo studies have focused on limited spectral ranges or selected anatomical sites. This study aimed to assess skin directional hemispherical reflectance across a broad spectral range and to provide an integrated dataset supporting emissivity-related interpretation in the infrared region. Methods: The study included 20 women aged 22–50 years (27 ± 9 years) with Fitzpatrick skin phototypes II–III. Reflectance measurements were performed at 14 anatomical sites using an ET 100 emissometer (1.9–21 µm) and an SOC 410 Solar DHR reflectometer (335–2500 nm). Infrared measurements were conducted at incidence angles of 20° and 60° to assess angular effects. Data were statistically analyzed. Results: The lowest reflectance values were observed within 335–380 nm, 1700–2500 nm, and 1.5–21 µm, whereas the highest reflectance was recorded in the 590–720 nm and 700–1100 nm bands. Reflectance symmetry between body sides was observed. In the infrared range, reflectance decreased with increasing wavelength, while mid- and far-infrared values were more uniform across locations. The highest reflectance values were noted for the thigh, calf (crural region), forearm, and palmar surface of the hand, whereas the lowest values were observed in the neck, abdominal region, and dorsal surface of the hand. Measurements at 60° incidence yielded higher reflectance values than those at 20°, while preserving spatial patterns. Conclusions: Directional hemispherical reflectance provides a robust approach for assessing skin reflectance across a broad spectral range. Reflectance depends on wavelength, anatomical location, and physiological factors, including epidermal thickness, pigmentation, and sebum presence. The integrated analysis of spectral, anatomical, and angular variability may support improved interpretation of skin optical properties and contribute to reference data for biomedical and infrared imaging applications. Full article

Musculoskeletal ultrasound (MSUS) is a well-established and reliable tool for the evaluation of entheses and enthesitis, particularly at larger and accessible sites. Recent technological advances, including high- and ultra-high-frequency transducers, have expanded its potential, enabling detailed assessment of distal extremity entheses. This narrative review provides a focused and updated perspective on this evolving field, highlighting three key advances. First, the identification and characterization of previously underrecognized entheseal sites in the distal extremities, such as pulley systems, retinacula, novel tendon insertions, and collateral ligaments, broadening the morphological spectrum of entheseal imaging. This is complemented by improved evaluation of vascularization through microvascular imaging and contrast-enhanced US (CEUS). Second, the emergence of interventional approaches, particularly US-guided entheseal biopsy, offers a novel means to investigate entheseal tissue in vivo and may establish a link between imaging and histopathology. Third, the integration of advanced functional imaging modalities, including elastography and multispectral optoacoustic tomography (MSOT), provides preliminary additional insights into the biomechanical and molecular properties of the enthesis beyond conventional structural assessment. Collectively, these developments support new investigational perspectives, positioning MSUS as a dynamic and integrative modality capable of exploring new anatomical territories and biological dimensions, with the potential to reshape the understanding and evaluation of entheseal involvement in rheumatology. Full article