Patients with congenital heart disease (CHD) have a propensity towards thrombotic events (TE) that can carry significant hemodynamic impact, morbidity, and mortality. Tissue plasminogen activator (tPA), a fibrinolytic agent, can be used in the acute treatment of thrombotic conditions but its use in pediatric patients with heart disease is not well described. We present our single-center experience of tPA infusion use in pediatric patients with congenital and acquired heart disease. This was a retrospective cohort study conducted between January 2008 and January 2024. Chart review was conducted to collect variables of interest. The primary outcome was thrombus resolution; secondary outcomes included major and minor bleeding events and in-hospital mortality. We identified 33 patients with 40 TE instances. 70% of patients had single ventricle circulation with cavopulmonary circulation being the most common thrombus location (39% of TE). The overall mortality among all patients was 39%; all patients with a major bleed experienced mortality. Major bleeding occurred in 12.5% of TE, associated with higher maximum tPA dose administered (0.2 vs. 0.1 mg/kg/hr, p = 0.036) and with recent surgery within 14 days of tPA administration (p = 0.0058). Fibrinogen nadir (< 150 mg/dL) and INR > 2 were associated with major bleeding (fibrinogen OR 13.5, CI 1.3-138.6, p = 0.02; INR OR 11.6, CI 1.5-92.1, p = 0.03). In our single-center experience, we demonstrated TE resolution of 58% and overall major bleeding rate of 12.5%. We also demonstrated the importance of tPA dosing, considering recent surgical intervention when determining tPA candidacy, and possible biomarkers to predict bleeding risk. Further investigation with a larger cohort is necessary.

Streptokinase (SK) is an effective plasminogen-activating fibrinolytic protein, but its lack of intrinsic fibrin specificity limits thrombus-directed fibrinolysis. We computationally evaluated an engineered SK-K2 fusion in which the fibrin-interacting Kringle 2 (K2) domain of human tissue-type plasminogen activator was appended to the SK C-terminus. Structural modeling showed high K2 confidence (mean pLDDT = 85.67), and all 22 K2 residues at the predicted fibrin interface had pLDDT values ≥70 (mean = 89.88). HDOCK ranked SK-K2-fibrin more favorably than native SK-fibrin (-276.71 vs. -249.24), while PRODIGY predicted a more favorable binding free energy (-14.9 vs. -13.3 kcal/mol). Although native SK showed a more favorable HDOCK score toward plasminogen, both plasminogen complexes had identical PRODIGY-predicted binding free energies (-11.2 kcal/mol) and closely comparable dissociation constants, indicating no marked computational loss in predicted plasminogen-binding characteristics after K2 fusion. PDBePISA showed direct K2 participation and a larger chain-matched fibrin interface for SK-K2 than native SK, with six hydrogen bonds and an Asp291-Arg515 salt bridge (2.966 Å) in the HDOCK-derived complex. An independent MOE workflow reproduced the fibrin-directed ranking, with SK-K2 showing a more favorable S score than native SK (-101.8501 vs. -93.9472). PDBePISA analysis of the independent MOE complex identified Arg515 in a second salt bridge, Arg515-Glu220 (3.369 Å), providing residue-level convergence across both docking models. These findings support the structural rationale for C-terminal K2 engineering of SK and prioritize SK-K2, particularly Arg515, for experimental evaluation of fibrin association, plasminogen activation, and clot-directed fibrinolysis.

Hemostasis and wound healing are highly coordinated processes that involve rapid clot formation followed by controlled remodeling of the injured tissue microenvironment. Prior work on Akhirin (AKH), a secreted extracellular matrix protein containing two von Willebrand factor A domains and an LCCL domain, has established it as a regulator of the neural stem niche in the developing brain and spinal cord injury microenvironment. However, its role as a non-hematopoietic molecule in the vascular injury response remains unknown. Here, we present evidence that AKH contributes to hemostasis and wound repair outside the neural niche. Our immunohistochemical and biochemical analyses demonstrated AKH around arterial tissues, suggesting a potential role at the blood-vessel interface. AKH-deficient mice exhibited a striking phenotype characterized by prolonged tail bleeding and delayed wound closure, indicating impaired vascular injury repair in vivo. Furthermore, bone marrow transplantation failed to rescue the prolonged bleeding phenotype, supporting a predominant non-hematopoietic contribution. Intriguingly, analysis of classical coagulation revealed an apparent paradox: activated partial thromboplastin time was shortened, whereas prothrombin time was not significantly altered. In contrast, increased expression of tissue plasminogen activator, urokinase-type plasminogen activator, and urokinase-type plasminogen activator receptor in AKH-deficient samples suggested dysregulated local fibrinolytic remodeling. Together, these findings identify AKH as a previously unrecognized extracellular regulator of hemostatic wound repair. Rather than indicating a defect in classical coagulation cascade activation, the findings associate AKH deficiency with impaired hemostatic control and altered expression of plasminogen activator system components, suggesting a role for AKH in the local vascular injury response.

Graft-versus-host disease (GvHD) remains a major complication in patients with hematological malignancies undergoing hematopoietic stem cell transplantation, driven by interconnected neutrophil activation, endothelial dysfunction, inflammation, and dysregulated coagulation. However, characterization of these pathways in GvHD patients remains limited. We used ELISA and flow cytometry to quantify biomarkers of neutrophil extracellular traps (NETs), cytokines, endothelial activation, fibrinolysis, coagulation, and immune cell subsets in peripheral blood of GvHD patients, and Western blot to assess NF-κB, STAT3, and p38 MAPK signaling. GvHD patients showed a thromboinflammatory profile, with elevated NET markers (MPO, cell-free DNA), increased cytokines (IL-1β, IL-8, MCP-1, TNF-α), and amplified platelet activation (P-selectin). Coagulation and fibrinolytic activity were enhanced, reflected by increased tissue factor (TF) and urokinase plasminogen activator (uPA), alongside higher frequencies of TF-expressing monocytes and platelet-monocyte aggregates. In vitro, TNF-α activated NF-κB, STAT3, and p38 MAPK signaling and increased ICAM-1- and VCAM-1-positive mononuclear cells, indicating a proinflammatory, adhesive phenotype, while transendothelial migration and nitric oxide levels were reduced. Leukemia patients with GvHD thus show a coordinated thromboinflammatory response involving NET activation, platelet-monocyte interactions, inflammatory signaling, endothelial dysfunction, and coagulation-fibrinolytic dysregulation, providing mechanistic insight into GvHD pathophysiology and highlighting circulating biomarkers as candidates for early detection, monitoring, and therapeutic intervention.

Carotid free-floating thrombus (CFFT) is a rare entity that can lead to life-threatening embolic events. An 80-year-old man presented with left-sided weakness. Computed tomography angiography (CTA) demonstrated bilateral carotid plaques with pedunculated mural thrombi and no hemodynamically significant stenosis. After intracranial hemorrhage was excluded, intravenous tissue plasminogen activator was administered. Within 12 hours, he developed a contralateral ischemic stroke; repeat CTA showed disappearance of the left internal carotid artery (ICA) thrombus, while magnetic resonance imaging demonstrated a new left hemispheric infarction. Carotid duplex ultrasound revealed a mobile right ICA thrombus consistent with CFFT. Urgent carotid endarterectomy (CEA) was performed without complications, and no further neurological events or hemorrhagic transformation occurred. This case suggests that urgent CEA may help prevent further embolic events in selected patients with CFFT.

Deformable Discoidal Polymeric Nanoconstructs (DPN) represent a biomimetic drug-delivery platform designed to overcome the limitations of conventional spherical nanoparticles. Their discoidal geometry, tunable deformability, and PLGA/PEG-based composition promote vascular margination, reduce phagocytic sequestration, prolong circulation, and enhance accumulation at pathological sites. This review highlights the design principles, fabrication strategies, therapeutic applications, and translational potential of DPN. In oncology, DPN have been engineered to improve the loading and sustained release of docetaxel through multi-passage fabrication, prodrug conjugation, and hierarchical micro-combinatorial hydrogel particles (µCGP). These discoidal particles enhanced therapeutic efficacy in preclinical models of triple-negative breast cancer, glioblastoma, and lung metastases. Beyond cancer, surface-functionalized DPN carrying tissue plasminogen activator improved clot targeting and thrombolysis while limiting neurological toxicity in ischemic stroke models. Overall, DPN integrate geometry, mechanics, and surface functionality to achieve vascular confinement, targeted delivery, and improved safety. Their modular design, biocompatible materials, and favorable preclinical performance support further development as versatile platforms for cancer therapy, metastatic disease, and thrombotic disorders.

Trauma-induced coagulopathy (TIC) is a rapidly evolving hemostatic disorder that develops early after severe injury and remains a major determinant of hemorrhagic mortality and thrombotic complications. Conventional coagulation tests provide limited information on the dynamic interactions among coagulation factors, platelets, fibrinogen, and fibrinolysis, often delaying targeted intervention. Viscoelastic hemostatic assays (VHAs), thromboelastography and rotational thromboelastometry, offer real-time whole-blood assessment of clot initiation, propagation, strength, and lysis. This narrative review synthesizes evidence on TIC pathophysiology, emphasizing shock-induced endotheliopathy, activated protein C signaling, platelet dysfunction, and the fibrinolytic spectrum. VHA-guided transfusion is examined against fixed-ratio protocols and low-titer group O whole blood. Equal attention is given to the boundaries of these assays. Because VHAs are static, low-shear tests performed without a vascular surface, they do not interrogate platelet adhesion and cannot detect the receptor shedding characteristic of exhausted platelet syndrome; a normal clot strength with an adequate platelet count may therefore coexist with impaired platelet plug formation. Initiation parameters are sensitive to acidosis, hypothermia, and endogenous heparinoids independently of factor concentration, and conventional assays cannot distinguish pathologic fibrinolytic shutdown from hypo-fibrinolysis. Two constraints limit generalizability of published thresholds. Parameters are not interchangeable between manufacturers or between device generations, so thresholds cannot be transferred, a limitation that also constrains meta-analysis. Reference values differ systematically by sex and age, and current trauma thresholds derive from predominantly male cohorts. Emerging approaches include provocative tissue plasminogen activator-challenged testing, dielectric coagulometry, and flow-based microfluidic assays that interrogate adhesion under shear.

Shade-tolerant herbs occurring across contrasting radiation environments may differ not only in photosynthetic capacity but also in how assimilated carbon is stored and used. We compared two varieties of Paris polyphylla associated with lower- and higher-elevation habitats: P. polyphylla var. chinensis (PPC) and P. polyphylla var. yunnanensis (PPY), respectively. Plants were grown for 40 d under light intensity of 50, 200, and 400 μmol m[-][2] s[-][1], and we measured leaf structure, gas exchange, chlorophyll fluorescence, carboxylation traits, non-structural carbohydrates, biomass allocation, and Paris saponin VII (PS VII). At 400 μmol m[-][2] s[-][1], PPY had higher net photosynthesis and light-saturated photosynthetic capacity than PPC. Rubisco and Rubisco activase activities, maximum rate of carboxylation and maximum rate of electron transport increased across the irradiance gradient in PPY, even though its stomatal and mesophyll conductance remained lower than in PPC. PPY also maintained a higher relative electron transport rate and a higher photorespiration rate, with little change in non-photochemical quenching (NPQ) or dark respiration. Increased irradiance shifted PPY biomass allocation belowground and increased its rhizome/leaf soluble sugar ratio. Foliar PS VII concentration and expression of PpUGT80A2 and PpSmt2-1 also increased more strongly in PPY. In PPC, light-saturated photosynthetic capacity peaked at 200 μmol m[-][2] s[-][1], whereas NPQ and dark respiration were higher and the leaf soluble sugar/starch ratio was lower at 400 μmol m[-][2] s[-][1]. These contrasts indicate that the response of PPY to increased growth irradiance was associated with greater biochemical capacity for CO2 assimilation, greater belowground allocation, and a larger foliar saponin pool. Whether saponin synthesis directly alleviates sink limitation or contributes to photoprotection requires direct measurements of carbon flux and oxidative damage.