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Bioengineered livers are currently an acceptable alternative to orthotopic liver transplants to overcome the scarcity of donors. However, the challenge of using a bioengineered liver is the lack of an intact endothelial layer in the vascular network leading to thrombosis. Heparin-modified surfaces have been demonstrated to decrease thrombogenicity in earlier research. However, in our study, we aimed to apply heparin immobilization to enhance the hemocompatibility, endothelial cell (EC) adhesion, and angiogenesis of rat decellularized liver scaffolds (DLS). Heparin was immobilized on the DLS by the end-point attachment technique. The scaffold’s hemocompatibility was assessed using ex vivo blood perfusion and platelet adhesion studies. The heparinized scaffold (HEP-DLS) showed a significantly reduced thrombogenicity and platelet aggregation. HEP-DLS was recellularized with EA.hy926 cells via the portal vein and maintained in the bioreactor for 7 days, showing increased EC adhesion and coverage within the blood vessels. The Resazurin reduction assay confirmed the presence of actively proliferating cells in the HEP-DLS. The scaffolds were implanted subcutaneously into the dorsum of mice for 21 days to evaluate cell migration and angiogenesis. The results showed significant increases in the number of blood vessels in the HEP-DLS group. Our results demonstrated that heparin immobilization reduces thrombosis, promotes re-endothelialization, and enhances angiogenesis in DLS. The research provides insight into the potential use of heparin in the formation of a functioning vasculature.

A 12–year–old castrated male mongrel was presented with an intestinal mass, weight loss, and hematochezia. Diagnostic imaging identified a soft tissue mass in the ileum and two enlarged intra–abdominal lymph nodes. Surgical resection was performed with intraoperative guidance using near–infrared fluorescence (NIRF) imaging and indocyanine green (ICG). The tumor exhibited reduced fluorescence compared to the surrounding intestine, enabling negative contrast–based visualization of the resection boundary and preservation of the ileocecal valve. Submucosal injection of ICG intraoperatively allowed clear visualization of lymphatic drainage and identification of a fluorescent sentinel lymph node (SLN). Histopathological examination confirmed complete excision of an invasive adenocarcinoma with tumor–free margins. The fluorescent lymph node was metastatic, while the non–fluorescent enlarged node was benign adipose tissue. The patient recovered uneventfully, with no recurrence or metastasis observed at the one–year follow–up. This case demonstrates the clinical utility of ICG–NIRF imaging in guiding margin assessment and SLN mapping during intestinal tumor surgery in a dog. The approach facilitated more accurate staging and conservative resection, potentially reducing surgical morbidity. This case report describes the first documented veterinary case of ICG–NIRF–guided resection and SLN mapping for canine intestinal adenocarcinoma.

Canine oral papillomatosis, caused by canine papilloma virus 1, is a benign condition primarily affecting young or immunosuppressed dogs. While most cases regress spontaneously, severe cases often require surgical intervention due to extensive lesions and associated discomforts. However, surgical excision is associated with a high risk of recurrence, necessitating adjuvant therapies. This report presents the case of a 1‐year‐old German Shepherd with severe oral papilloma unresponsive to prior treatments, managed through surgical excision followed by topical mitomycin C (MMC) application. MMC, applied intraoperatively and during follow‐up, effectively prevented recurrence over a 1‐year period. This case demonstrates the potential of MMC as an effective adjuvant therapy for severe canine oral papillomatosis, providing a novel approach in veterinary medicine. Topical application of mitomycin C after surgical excision in a canine oral papilloma case significantly enhanced mucosal recovery and reduced recurrence. This approach demonstrates potential as an adjuvant therapy in oral papillomatosis management.

Platelet G protein-coupled receptors (GPCRs) regulate platelet function by mediating the response to various agonists, including adenosine diphosphate (ADP), thromboxane A2, and thrombin. Although GPCR kinases (GRKs) are considered to have the crucial roles in most GPCR functions, little is known regarding the regulation of GPCR signaling and mechanisms of GPCR desensitization by GRKs in platelets. In this study, we investigated the functional role of GRK6 and the molecular basis for regulation of specific GPCR desensitization by GRK6 in platelets. We used GRK6 knockout mice to evaluate the functional role of GRK6 in platelet activation. Platelet aggregation, dense- and α-granule secretion, and fibrinogen receptor activation induced by 2-MeSADP, U46619, thrombin, and AYPGKF were significantly potentiated in GRK6−/− platelets compared to the wild-type (WT) platelets. However, collagen-related peptide (CRP)-induced platelet aggregation and secretion were not affected in GRK6−/− platelets. Interestingly, platelet aggregation induced by co-stimulation of serotonin and epinephrine which activate Gq-coupled 5HT2A and Gz-coupled α2A adrenergic receptors, respectively, was not affected in GRK6−/− platelets, suggesting that GRK6 was involved in specific GPCR regulation. In addition, platelet aggregation in response to the second challenge of ADP and AYPGKF was restored in GRK6−/− platelets whereas re-stimulation of the agonist failed to induce aggregation in WT platelets, indicating that GRK6 contributed to P2Y1, P2Y12, and PAR4 receptor desensitization. Furthermore, 2-MeSADP-induced Akt phosphorylation and AYPGKF-induced Akt, extracellular signal-related kinase (ERK), and protein kinase Cδ (PKCδ) phosphorylation were significantly potentiated in GRK6−/− platelets. Finally, GRK6−/− mice exhibited an enhanced and stable thrombus formation after FeCl3 injury to the carotid artery and shorter tail bleeding times, indicating that GRK6−/− mice were more susceptible to thrombosis and hemostasis. We conclude that GRK6 plays an important role in regulating platelet functional responses and thrombus formation through selective GPCR desensitization.

Liver transplantation is the last resort for liver failure patients. However, due to the shortage of donor organs, bioengineered liver generated from decellularized whole liver scaffolds and induced pluripotent stem cell (iPSC)-derived hepatocytes (iPSC-Heps) is being studied as an alternative approach to treat liver disease. Nevertheless, there has been no report on both the interaction of iPSC-Heps with a liver extracellular matrix (ECM) and the analysis of recellularized iPSC-Heps into the whole liver scaffolds. In this study, we produced porcine iPSC-Heps, which strongly expressed the hepatic markers α-fetoprotein and albumin and exhibited hepatic functionalities, including glycogen storage, lipid accumulation, low-density lipoprotein uptake, and indocyanine green metabolism. Supplementation of ECM from porcine decellularized liver containing liver-derived growth factors stimulated the albumin expression of porcine iPSC-Heps during differentiation procedures. The iPSC-Heps were reseeded into decellularized liver scaffolds, and the recellularized liver was cultured using a continuous perfusion system. The recellularized liver scaffolds were transplanted into rats for a short term, and the grafts expressed hepatocyte markers and did not rupture. These results provide a foundation for development of bioengineered liver using stem cell and decellularized scaffolds.

Diabetic retinopathy (DR), a complication of diabetes, causes damage to retinal blood vessels and can lead to vision impairment. Persistent high blood glucose levels contribute to this damage, and despite ongoing research, effective treatment options for DR remain limited. Dimethyl sulfoxide (DMSO) has shown anti-inflammatory and antioxidant properties in both in vivo and in vitro studies; however, its potential as an anti-inflammatory agent in the context of DR has not yet been explored. This study aimed to assess the effects of subconjunctival injection of DMSO on the progression of DR. DR was induced in rats using intraperitoneal injections of streptozotocin (55 mg/kg), confirmed by measuring blood glucose levels and electroretinography (ERG). The rats were divided into five groups: a normal control group (CON), a DR control group receiving PBS injections (DMSO 0), and three DR groups receiving different concentrations of DMSO (98%, 50%, and 10%). Retinal function was evaluated using ERG at weeks 10 and 14, and histological analysis at week 16. The DMSO 50 group had significantly higher B-wave amplitude in ERG compared to the DMSO 0 group (p<0.05). Flicker response amplitudes were also significantly greater in the DMSO 50 and DMSO 10 groups compared to DMSO 0 (p<0.05). Histological examination revealed thinner retinal layers in the DMSO 0 group compared to the CON group, while the DMSO-treated groups showed improved retinal thickness. Subconjunctival injection of 50% DMSO appears to improve retinal function in a rat model of DR.

Background This study aims to investigate the anatomical differences in the anterior segment of the eyes between dogs and cats using ultrasound biomicroscopy (UBM) to understand the higher prevalence of primary angle-closure glaucoma (PACG) in dogs compared to cats. Retrospective analysis was performed on clinical data from 16 eyes of 16 dogs and 14 eyes of 14 cats with normal eye conditions. UBM was utilized to measure nine specific parameters, including Schwalbe’s Line Distance (SLD), Iridocorneal Angle (ICA), Angle-Opening Distance (AOD), and three ciliary cleft parameters: width (CCW), length (CCL), and area (CCA). To account for differences in body size, ciliary cleft parameters were adjusted accordingly. Results Significant anatomical differences in the anterior segment were found between the two species. Dogs had smaller values for SLD, ICA, AOD, and ciliary cleft parameters (CCW, CCL, CCA) compared to cats. Even after body-size adjustment, the rectified ciliary cleft parameters remained smaller in dogs. Conclusion The anatomical differences, particularly the smaller ciliary cleft and narrower drainage angles in dogs, may contribute to the higher prevalence of PACG in this species. Conversely, the larger ciliary cleft in cats may explain the lower occurrence of primary glaucoma in cats.

Various incurable eye diseases in companion animals often result in phthisis bulbi and eye removal surgery. Currently, the evisceration method using silicone balls is useful in animals; however, it is not available to those with impaired cornea or severe ocular atrophy. Moreover, ocular implant and prostheses are not widely used because of the diversity in animal size and eye shape, and high manufacturing cost. Here, we produced low-cost and customized artificial eyes, including implant and prosthesis, using computer-aided design and three-dimensional (3D) printing technique. For 3D modeling, the size of the artificial eyes was optimized using B-mode ultrasonography. The design was exported to STL files, and then printed using polycaprolactone (PCL) for prosthesis and mixture of PCL and hydroxyapatite (HA) for ocular implant. The 3D printed artificial eyes could be produced in less than one and half hour. The prosthesis was painted using oil colors and biocompatible resin. Two types of eye removal surgery, including evisceration and enucleation, were performed using two beagle dogs, as a preliminary study. After the surgery, the dogs were clinically evaluated for 6 months and then histopathological evaluation of the implant was done. Ocular implant was biocompatible and host tissue ingrowth was induced after in vivo application. The custom-made prosthesis was cosmetically excellent. Although long-term clinical follow-up might be required, the use of 3D printed-customized artificial eyes may be beneficial for animals that need personalized artificial eye surgery.

In this review, we explore the transformative role of Ultrasound Biomicroscopy (UBM) in veterinary ophthalmology, focusing on its utility in evaluating the iridocorneal angle and ciliary body in dogs. We begin by outlining UBM’s foundational principles, providing a holistic understanding of its operational mechanics. This is followed by an exploration of the techniques and considerations for optimal UBM imaging, including the use of topical anesthesia, probe positioning, and maintaining a controlled measurement environment. A major section is dedicated to the detailed anatomy of the anterior segment, emphasizing the iridocorneal angle and ciliary body in controlling aqueous humor dynamics within canine and feline eyes. By comparing anatomical structures in humans and animals, we highlight the need for distinct parameters in veterinary medicine. The review also analyzes the parameters obtainable via UBM, emphasizing its potential in monitoring drug-induced ocular changes, gaging post-cataract surgical outcomes, and observing inter-species variations. We conclude by encapsulating the current state of research, addressing existing challenges, and suggesting future research avenues. This synthesis underscores the pivotal role of UBM in advancing veterinary ophthalmic diagnostics and research.

A 13-year-old castrated male, Maltese was presented for abnormal findings of gallbladder on abdominal ultrasonography without clinical signs. Abdominal ultrasonography revealed a severely distended gallbladder and a heterogeneous echogenic mass in the gallbladder neck. No evidence of metastasis was observed. Cholecystectomy was performed with indocyanine green near-infrared fluorescence imaging for real-time visualization of the biliary tract that contributed to improve surgical outcomes. In the histopathological examination and immunohistochemical analysis using smooth muscle actin staining, the gallbladder mass was confirmed as a leiomyosarcoma. The patient has been followed up for 18 months without any signs of recurrence or metastasis. This is the first reported case of gallbladder leiomyosarcoma in dogs. Leiomyosarcoma should be considered a differential diagnosis for dogs with gallbladder mass. The histologic low grading, the absence of microscopic residual tumor and metastasis relate to good prognosis.