Assessment of cytochrome P450 induction in canine intestinal organoid models.

Understanding cytochrome P450 (CYP) enzymes in the canine intestine is vital for predicting drug metabolism and developing safer oral medications. This study evaluates canine colonoids as a model to assess the expression and induction of essential intestinal CYP enzymes.Canine colonoids were cultured in expansion medium (EM) with Wnt-3A and in differentiation medium (DM) without Wnt-3A. We assessed the mRNA expression of CYP2B11, CYP2C21, CYP3A12, and CYP3A98 using qPCR and examined the effects of rifampicin and phenobarbital as inducers.Our findings show that DM significantly increased the mRNA expression of CYP3A98 and CYP2B11, but not CYP3A12, compared to EM. CYP2C21, not typically expressed in the intestine, remained unexpressed in colonoids. Rifampicin induced CYP3A98, aligning with pregnane x receptor (PXR) regulation, while phenobarbital did not, suggesting no constitutive androstane receptor (CAR) involvement. CYP2B11 did not respond to either inducer, suggesting alternative regulatory pathways in canine colonoids.This study is a pioneering effort to establish conditions for studying P450 expression in canine colonoids, confirming significant CYP3A98 expression in the canine intestine. It demonstrated colonoids can induce CYP activity post drug treatments. Further research is needed to enhance species-specific drug metabolism understanding and validate this model for broader applications.

Comprehensive hemocompatibility analysis on the application of diamond-like carbon to ePTFE artificial vascular prosthesis.

The aim of this study was to obtain comprehensive data regarding the hemocompatibility of diamond-like carbon (DLC)-coated expanded polytetrafluoroethylene (ePTFE). DLC increased the hydrophilicity and smoothened the surface and fibrillar structure, respectively, of the ePTFE. DLC-coated ePTFE had more albumin and fibrinogen adsorption and less platelet adhesion than uncoated ePTFE. There were scarce red cell attachments in in vitro human and in vivo animal (rat and swine) whole blood contact tests in both DLC-coated and uncoated ePTFE. DLC-coated ePTFE had a similar but marginally thicker band movement than uncoated-ePTFE with SDS-PAGE after human whole blood contact test. In addition, survival studies of aortic graft replacement in rats (1.5 mm graft) and arteriovenous shunt in goats (4 mm graft) were performed to compare the patency and clot formation between DLC-coated and uncoated ePTFE grafts. Comparable patency was observed in both animal models. However, clots were observed in the luminal surface of the patent 1.5 mm DLC-coated ePTFE grafts, but not in that of uncoated ePTFE grafts. In conclusions, hemocompatibility of DLC-coated ePTFE was high and comparable to that of uncoated ePTFE. However, it failed to improve the hemocompatibility of 1.5 mm ePTFE graft probably because increased fibrinogen adsorption canceled the other beneficial effects of DLC.

Farm and Companion Animal Organoid Models in Translational Research: A Powerful Tool to Bridge the Gap Between Mice and Humans.

Animal organoid models derived from farm and companion animals have great potential to contribute to human health as a One Health initiative, which recognize a close inter-relationship among humans, animals and their shared environment and adopt multi-and trans-disciplinary approaches to optimize health outcomes. With recent advances in organoid technology, studies on farm and companion animal organoids have gained more attention in various fields including veterinary medicine, translational medicine and biomedical research. Not only is this because three-dimensional organoids possess unique characteristics from traditional two-dimensional cell cultures including their self-organizing and self-renewing properties and high structural and functional similarities to the originating tissue, but also because relative to conventional genetically modified or artificially induced murine models, companion animal organoids can provide an excellent model for spontaneously occurring diseases which resemble human diseases. These features of companion animal organoids offer a paradigm-shifting approach in biomedical research and improve translatability of in vitro studies to subsequent in vivo studies with spontaneously diseased animals while reducing the use of conventional animal models prior to human clinical trials. Farm animal organoids also could play an important role in investigations of the pathophysiology of zoonotic and reproductive diseases by contributing to public health and improving agricultural production. Here, we discuss a brief history of organoids and the most recent updates on farm and companion animal organoids, followed by discussion on their potential in public health, food security, and comparative medicine as One Health initiatives. We highlight recent evolution in the culturing of organoids and their integration with organ-on-a-chip systems to overcome current limitations in in vitro studies. We envision multidisciplinary work integrating organoid culture and organ-on-a-chip technology can contribute to improving both human and animal health.

Outbreak of toxoplasmosis in four squirrel monkeys (Saimiri sciureus) in Japan.

Toxoplasma gondii is a protozoan parasite that causes fatal disease in New World monkeys. Several reports have described outbreaks of toxoplasmosis in squirrel monkeys. Here, we report the death of four squirrel monkeys in a captive colony from acute toxoplasmosis, one of which developed toxoplasmosis about 1 year after the initial outbreak. Serum anti-T. gondii antibody was detected by a latex agglutination test in the animals, and one presented seropositive before clinical signs were observed. Macroscopically, the lungs were severely affected and three animals showed pulmonary edema. Microscopically, interstitial pneumonia was observed in all animals. In the liver and heart, multifocal mononuclear cell infiltration with necrosis was detected. Parasite loading tended to be higher in the lungs, liver and heart than in the spleen, kidney and brain. The parasite was isolated from the brain of one animal and this isolate showed type II restriction patterns in the SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2 and PK1 genes of T. gondii and type I restriction patterns in the L358 and Apico genes by PCR-Restriction Fragment Length Polymorphism analysis. The clinical signs were reduced in mice infected with this isolate compared with those infected with reference type II strain PLK in a bioassay. To our knowledge, this is the first report of isolation of the parasite from squirrel monkeys in Japan and offers the opportunity for genomic and pathogenic analyses to aid our understanding of acute toxoplasmosis.

Perforating abomasal ulcer caused by yolk sac tumor in a Holstein calf.

A 2-month-old male Holstein calf showed clinical signs of abdominal bloating, melena, and pain and was suspected of having a perforating abomasal ulcer. Necropsy revealed a large mass located preferentially around the abomasum and a large perforating abomasal ulcer on the pyloric antrum. Milky white masses of various sizes were also found in the abdominal cavity that consisted of agglutinated nodules ranging in size from a pinhead to a golf ball and were distributed on the surfaces of the liver, reticulum, omasum, abomasum, and diaphragm. Microscopic examination revealed that the masses were composed primarily of hyaline matrices, epithelioid tumor cells, and large atypical cells with hyaline droplets and/or vacuoles. Stromal hyaline matrices and hyaline droplets of the large tumor cells stained positive with periodic acid-Schiff stain. Tumor cells showed a positive reaction to anti-human alpha-fetoprotein, which is a marker of yolk sac tumors. These findings strongly suggested that the masses found in the abdominal cavity were yolk sac tumor, a rare germ cell tumor in cattle.