The prevalence of elevated gamma-glutamyltransferase and sorbitol dehydrogenase activity in racing Thoroughbreds and their associations with viral infection

Hepatic Enzyme Profile in Horses

For diagnostic purposes, liver enzymes are usually classified into hepatocellular and cholestatic. These two groups of equine liver-specific enzymes include sorbitol dehydrogenase (SDH), glutamate dehydrogenase (GLDH), γ-glutamyl transferase (GGT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and alkaline phosphatase (ALP). SDH and GLDH mostly reflect hepatocellular injury and cholestasis, while GGT expresses high values in biliary necrosis or hyperplasia. Likewise, AST, LDH, and ALP also reflect hepatocellular and biliary disease, but these enzymes are not liver specific. From the clinical point of view of the course of liver or biliary disease, AST and ALP are indicative of chronic disease, whereas SDH, GGT, and GLDH indicate an acute course. The patterns of enzymatic changes at the blood level are associated with different types of liver pathologies (infectious, inflammatory, metabolic, toxic, etc.). Increases in hepatocellular versus biliary enzyme activities are indicative of a particular process. There are different ways to diagnose alterations at the hepatic level. These include the evaluation of abnormalities in the predominant pattern of hepatocellular versus cholestatic enzyme abnormalities, the mild, moderate, or marked (5−10-fold or >10-fold) increase in enzyme abnormality concerning the upper limit of the reference range, the evolution over time (increase or decrease) and the course of the abnormality (acute or chronic).

Antibiotic-Loaded MMT/PLL-Based Coating on the Surface of Endosseous Implants to Suppress Bacterial Infections

BACKGROUND

Bone infections remain one of the most common and serious complications of orthopedic surgery, posing a tremendous economic burden to society and patients. This is because bacteria colonize and multiply on the surface of the implant. The (MMT/PLL)8 multilayer films have been shown to effectively release antibiotics depending on the changes in the microenvironment. Here, vancomycin was loaded into the (MMT/PLL)8 multilayer films, which were prepared to be used as a local delivery system for the treatment of bone infections.

METHODS

We used the layer-by-layer self-assembly method to prepare VA-loaded coatings (MMT/PLL-VA)8 consisting of montmorillonite (MMT), poly-L-lysine (PLL), and VA. The thickness and surface morphology of coatings were characterized using spectroscopic ellipsometry and scanning electron microscopy (SEM). In order to evaluate the drug release behavior from coatings in different media, we measured the size of the zone of inhibition. Additionally, in vitro antibacterial activity was assessed using the shake-flask culture method and SEM images, while that of in vivo was evaluated by establishing an animal model of bone infection.

RESULTS

Our findings revealed that small-molecule antibiotics were successfully loaded into the (MMT/PLL-VA)8 multilayer film structure during the hierarchical self-assembly process and subsequently the multilayer film structure depicted linear growth behavior. The PLL in the multilayer films was progressively degraded which triggered the VA release when contacted with CMS or bacterial infections. The release of VA from multilayer film structure depends on the concentration changes of CMS. Notably, the multilayer films presented great in vitro cell compatibility. Moreover, the prepared antibacterial multilayer films showed excellent antibacterial property by killing more than 99.99% of S. aureus in 24 h. More importantly, we found that multilayer film exhibits good sterilization effect and biocompatibility under the stimulation of bacterial liquid both in vitro and in vivo antibacterial ability tests.

CONCLUSION

Altogether, this study shows that (MMT/PLL-VA)8 multilayer films containing CMS and bacteria-responsive drug release properties posess high bactericidal activity and good biocompatibility. This finding provides a novel strategy for the treatment of bone infections.

Tropism, pathology, and transmission of equine parvovirus-hepatitis

Equine parvovirus-hepatitis (EqPV-H) has recently been associated with cases of Theiler's disease, a form of fulminant hepatic necrosis in horses. To assess whether EqPV-H is the cause of Theiler's disease, we first demonstrated hepatotropism by PCR on tissues from acutely infected horses. We then experimentally inoculated horses with EqPV-H and 8 of 10 horses developed hepatitis. One horse showed clinical signs of liver failure. The onset of hepatitis was temporally associated with seroconversion and a decline in viremia. Liver histology and in situ hybridization showed lymphocytic infiltrates and necrotic EqPV-H-infected hepatocytes. We next investigated potential modes of transmission. Iatrogenic transmission via allogeneic stem cell therapy for orthopedic injuries was previously suggested in a case series of Theiler's disease, and was demonstrated here for the first time. Vertical transmission and mechanical vectoring by horse fly bites could not be demonstrated in this study, potentially due to limited sample size. We found EqPV-H shedding in oral and nasal secretions, and in feces. Importantly, we could demonstrate EqPV-H transmission via oral inoculation with viremic serum. Together, our findings provide additional information that EqPV-H is the likely cause of Theiler's disease and that transmission of EqPV-H occurs via both iatrogenic and natural routes.

Clinical Pathology of the Racehorse

The assessment of blood analytes in racehorses can provide useful data on performance and health. The horses' adaptive responses to training that occur to optimize performance should be considered when interpreting alterations seen on laboratory results. Similarly, the alterations observed in laboratory test results can identify subclinical and clinical disease and be helpful for identifying organ dysfunction and, in many cases, monitoring progress and response to treatment. This article discusses hematologic and biochemical tests that are important in the evaluation of performance and health in racehorses.