Liver Of Horses Research Articles

Duplication of blaCTX-M-1 and a class 1 integron on the chromosome enhances antimicrobial resistance in Escherichia coli isolated from racehorses in Japan

Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae have become a cause for great concern. Although some studies have reported the prevalence of ESBL-producing bacteria and ESBL-encoding genes in horses worldwide, the genetic structure surrounding the ESBL gene has not been analysed in detail. In the present study, we isolated two ESBL-producing Escherichia coli strains from diseased racehorses in Japan and demonstrated the mechanisms underlying the acquisition of their antimicrobial resistance (AMR) genes. Two ESBL-producing E. coli strains (E148 and E189) were isolated from the heart and liver of horses with endocarditis and sepsis in 2014 and 2016, respectively, in Japan. Complete genomic sequences of the two strains were analysed using a PacBio RSII sequencer. Antimicrobial susceptibility testing was performed by the agar dilution method. The two isolates possessed a chromosomal AMR gene cluster containing blaCTX-M-1 that was similar to the pEQ1 plasmid found in E. coli isolated from a racehorse in the Czech Republic. In one of the two strains, tandem duplication of the 16-kb region containing blaCTX-M-1 and a class 1 integron, which occurred via IS26-mediated recombination, increased minimum inhibitory concentrations (MICs) associated with the duplicated AMR genes. Chromosomal blaCTX-M-1 possibly derived from the pEQ1 or pEQ1-like plasmid was found in Japanese equine E. coli isolates. In Japanese strains, many AMR genes containing blaCTX-M-1 and the class 1 integron are highly accumulated in one region on the chromosome, and the AMR of E. coli was enhanced via the IS26-mediated duplication of the AMR gene cluster.

Further Evidence for in Utero Transmission of Equine Hepacivirus to Foals.

(1) Background: Equine hepacivirus (EqHV), also referred to as non-primate hepacivirus (NPHV), infects horses—and dogs in some instances—and is closely related to hepatitis C virus (HCV) that has infected up to 3% of the world’s human population, causing an epidemic of liver cirrhosis and cancer. EqHV also chronically infects the liver of horses, but does not appear to cause serious liver damages. Previous studies have been looking to identify route(s) of EqHV transmission to and between horses. (2) Methods: In this retrospective study, we sought to evaluate the prevalence of vertical transmission taking place in utero with measuring by quantitative RT-PCR the amounts of EqHV genome in samples from 394 dead foals or fetuses, paired with the allantochorion whenever available. (3) Results: Detection of EqHV in three foals most likely resulted from a vertical transmission from the mares to the fetuses, consistent with the in utero transmission hypothesis. In support of this observation, the presence of EqHV genome was found for the first time in two of the allantochorions. (4) Conclusions: As seemingly benign viruses could turn deadly (e.g., Zika flavivirus) and EqHV happens to have infected a significant proportion of the world’s horse herds, EqHV infectious cycle should be further clarified.

Excessive Endoplasmic Reticulum Stress Correlates with Impaired Mitochondrial Dynamics, Mitophagy and Apoptosis, in Liver and Adipose Tissue, but Not in Muscles in EMS Horses.

Nowadays, endocrine disorders have become more frequent in both human and veterinary medicine. In horses, reduced physical activity combined with carbohydrate and sugar overload may result in the development of the so-called equine metabolic syndrome (EMS). EMS is characterized by insulin resistance, hyperinsulinemia, elevated blood triglyceride concentrations and usually obesity. Although the phenotypic features of EMS individuals are well known, the molecular mechanism underlying disease development remains elusive. Therefore, in the present study, we analyzed insulin-sensitive tissues, i.e., muscles, liver and adipose tissue in order to evaluate insulin resistance and apoptosis. Furthermore, we assessed mitochondrial dynamics and mitophagy in those tissues, because mitochondrial dysfunction is linked to the development of metabolic syndrome. We established the expression of genes related to insulin resistance, endoplasmic reticulum (ER) stress and mitochondria clearance by mitophagy using RT-PCR and Western blot. Cell ultrastructure was visualized using electron transmission microscopy. The results indicated that adipose tissue and liver of EMS horses were characterized by increased mitochondrial damage and mitophagy followed by triggering of apoptosis as mitophagy fails to restore cellular homeostasis. However, in muscles, apoptosis was reduced, suggesting the existence of a protective mechanism allowing that tissue to maintain homeostasis.

Ultrasonographic examination of liver and spleen of normal adult spiti horses and Himalayan Hill mules of India

The main objective of this study was to develop baseline topographical data of landmarks for locating liver and spleen and to generate sonographic calliper measurements along with dynamic parameters of these organs. Abdominal ultrasonography was performed on 50 native adult (Spiti horses and Himalayan hill mules) healthy unsedated equines of either sex. The thickness, character and echo-architecture of liver and spleen were recorded. In horses, the right lobe of liver was found from 8th to 15th intercostal space (ICS) and left lobe from 6th to 11th (±1) ICS, while in mules the right liver lobe was found between 6th to 15th (±1) ICS and left lobe between 6th to 9th (±1) ICS. The liver was recognized by its branching vasculature and architecture was found relatively homogenous. In addition ventral edges were distinctly sharp. Spleen was found from 8th to 17th ICS both in horses as well as in mules. The splenic parenchyma was homogenously granular in appearance with few blood vessels and most echogenic organ in the abdominal cavity of equines. The only measurement that was reliably obtained was the central thickness or depth of the spleen, which varied from 41.4 to 68.4 mm (Mean± SE= 50.84±4.61 mm) in horses and 37.9 to 51.6 mm (Mean± SE = 42.76±2.34 mm) in mules. Therefore detailed ultrasonographic examination of liver and spleen helped us to compile baseline data, which will be helpful in management of the affections of liver and spleen in future.

Setting of import tolerances for benzovindiflupyr in various plant and animal origin commodities

In accordance with Article 6 of Regulation (EC) No 396/2005, the evaluating Member State (EMS), France, received an application from Syngenta Crop Protection AG to set import tolerances for benzovindiflupyr in several crops and in certain animal products. According to EFSA, the data are sufficient to derive maximum residue level (MRL) proposals for the imported crops under consideration, except for cucurbits with inedible peel. For coffee beans and liver of ruminants and horses, different risk management options were derived. Adequate analytical enforcement methods are available to control the residues of benzovindiflupyr in plant and animal origin commodities. Based on the risk assessment results, EFSA concludes that the uses of benzovindiflupyr notified for the products under consideration will not result in a consumer exposure exceeding the toxicological reference values and therefore are unlikely to pose a health risk to consumers.

Concentrations of strontium, barium, cadmium, copper, zinc, manganese, chromium, antimony, selenium and lead in the equine liver and kidneys.

The concentrations of specific elements in the equine liver and kidneys are of practical relevance since horses are not only food-producing animals, but also partially serve as an indicator for the environmental pollution, as the basic feed includes plants like grass, grain and fruits. In this study, the concentrations of strontium (Sr), barium (Ba), cadmium (Cd), copper (Cu), zinc (Zn), manganese (Mn), chromium (Cr), antimony (Sb), selenium (Se) and lead (Pb) were measured in the liver, renal cortex and renal medulla of 21 horses (8 male; 13 female; aged between 5 months-28 years), using inductively coupled plasma mass spectrometry. Comparable Cu and Zn concentrations were detected in the liver and renal cortex, while approximately 50% lower concentrations were measured in the renal medulla. The lowest Sr, Cd and Se, but the highest Mn, Sb and Pb concentrations were measured in the liver. The Ba concentrations were comparable in the renal cortex and medulla, but lower in the liver of the horses. Gender-related differences were observed for Cd, Mn and Cr, with higher Cd concentrations in the liver, but lower Mn concentrations in the renal cortex and lower Cr concentrations in the renal medulla of female horses. Age-related differences were detected for most measured elements, however, the animal number per age-group was only low. In conclusion, the present study provides important reference data for the storage of Sr, Ba, Cd, Cu, Zn, Mn, Cr, Sb, Se and Pb in the liver and kidneys of horses, which are of practical relevance for an evaluation of the exposure of horses to these elements, either via feed or the environment.Electronic supplementary materialThe online version of this article (doi:10.1186/2193-1801-3-343) contains supplementary material, which is available to authorized users.

Long term intensive exercise training leads to a higher plasma malate/lactate dehydrogenase (M/L) ratio and increased level of lipid mobilization in horses

Continuous high intensity training may induce alterations to enzyme activities related to glucose and lipid metabolism in horses. In our study, five Thoroughbred race horses (3 male and 2 female, avg age=5 yrs old) were compared against five riding horses (1 male, 1 female, 3 gelding, avg age=13 yrs old) in terms of energy metabolism, by examining plasma malate (MDH) and lactate (LDH) dehydrogenase activities and M/L ratio. MDH is involved in NADH and ATP generation, whereas LDH can convert NADH back into NAD(+) for ATP generation. An increase in plasma M/L ratio can reflect heightened energy metabolism in the liver and skeletal muscle of horses adapted to continuous intensive exercise. Moreover, plasma lipid metabolism analytes (adiponectin, NEFA, total cholesterol (T-Cho), and triglycerides (TG)) can reflect changes to lipolysis rate, which can also indicate a change in energy metabolism. Overall, race horses demonstrated increased MDH and LDH activity in plasma (4x and 2x greater, respectively), in addition to a plasma M/L ratio twice as high as that of riding horses (2.0 vs 1.0). In addition, race horses also demonstrated significantly higher levels of plasma NEFA (50% greater), TG (2x greater), and T-Cho (20% greater) as compared to riding horses. Therefore, race horse muscles may have adapted to prolonged high intensity endurance exercise by gaining a higher oxidative capacity and an increased capacity for fat utilization as an energy source, resulting in heightened energy metabolism and increased rate of lipid mobilization.

Heterobilharzia americana infection as a cause of hepatic parasitic granulomas in a horse

CASE DESCRIPTION-A 22-year-old American Paint Horse gelding from the Gulf Coast region of Texas was evaluated for regrowth of a perirectal squamous cell carcinoma that had been surgically removed 11 months previously. CLINICAL FINDINGS-A necrotic and ulcerated mass was present below the anus. The horse had paraphimosis and was having difficulty with urination. Histologic examination of the mass revealed that it was squamous cell carcinoma, and the horse was euthanized because of the unlikelihood that the mass could be adequately resected and its close proximity to the urethra. OUTCOME-At necropsy, in addition to the squamous cell carcinoma, hundreds of round, white to pale yellow nodules were disseminated throughout the liver, resulting in a so-called starry-sky appearance. Similar granulomas were seen in the right caudal lung lobe and small intestinal serosa. A single granuloma in the liver, which differed from the others by its larger size, contained a pair of adult schistosomes. Several hepatic granuloma specimens were used for PCR amplification and sequencing. Use of primers specific for a portion of the Heterobilharzia americana small subunit rRNA gene resulted in amplification of a 487-base pair product that had 100% sequence identity with H americana. CLINICAL RELEVANCE-Severe cases of disseminated granulomas in the liver of horses may result in a liver with a grossly abnormal starry-sky pattern. To our knowledge, this is the first report documenting the association of granulomas with H americana infection along with adult schistosomes in the liver of a horse.

Lipopolysaccharide infusion up-regulates hepcidin mRNA expression in equine liver

Hepcidin has been found to be the key regulator of iron metabolism that leads to hypoferremia during inflammation. Recent work has shown that equine hepcidin is predominantly expressed in the liver of horses. In this study, hepcidin gene expression was determined in the liver and bone marrow of six healthy horses after iv infusion of Escherichia coli O55:B5 LPS. The IL-6 gene expression was also determined in liver and bone marrow samples. Clinical and laboratory evaluations were measured at multiple time points between 0 and 240 h post-LPS infusion (PI). Liver and bone marrow biopsies were taken immediately before (baseline) and at 6 and 18 h PI. In response to endotoxin infusion, all horses showed characteristic clinical signs of endotoxemia. Plasma iron concentration was decreased significantly from the pre-infusion level at 8 h PI. Hypoferremia peak was observed at 12 h and returned to normal levels at 30 h PI. Relative real-time RT-PCR analysis showed that liver hepcidin and IL-6 mRNA expression was up-regulated at 6 h PI. Bone marrow hepcidin relative expression was not influenced by LPS infusion. In another experiment, equine monocyte cultures were stimulated with LPS (1 µg/ml). Monocyte hepcidin and IL-6 gene expression was significantly induced after 2 h of LPS stimulus and returned to baseline levels thereafter. The present study describes that, in horses, LPS infusion up-regulates hepatic hepcidin mRNA expression resulting in early observed hypoferremia and suggests that hepcidin may act as an acute-phase protein in horses.

Intrahepatic ramifications of the portal vein in the horse

Summary The ramifications of the portal vein in the liver of horses were studied by using corrosion casting and gross dissection. The portal vein in the horse supplies the hepatic lobes by six major branches. The right lobe is supplied by three main branches, namely the dorsal diaphragmatic, the right caudodorsal and the right intermediate branches. The left branch supplies the left lateral and medial lobes and parts of the quadrate lobe adjacent to the left medial lobe. The caudate branch supplies caudate process of the caudate lobe. The right common trunk supplies also a part of right lobe and quadrate lobe. Therefore, the pattern of blood distribution in portal vein of horse differs from that of other species.

Cloning of equine chemokines eotaxin, monocyte chemoattractant protein (MCP)-1, MCP-2 and MCP-4, mRNA expression in tissues and induction by IL-4 in dermal fibroblasts

We report the cloning of four equine CC chemokines, eotaxin, monocyte chemoattractant protein (MCP)-1, MCP-2 and MCP-4, which show high levels of identity with their respective homologous sequences in other species. Using a multiplex RT–PCR, we have studied the constitutive mRNA expression of these four CC chemokines in skin, lung, liver, spleen, jejunum, colon and kidney of normal adult horses and compared this data with the eosinophil counts in the same samples. We demonstrate that eotaxin mRNA is only expressed in jejunum and colon, where there are large numbers of eosinophils suggesting that eotaxin might be recruiting eosinophils in the normal digestive tract of the horse. MCP-1 and MCP-4 are expressed in all tissues whereas MCP-2 is only found in some samples of lung, spleen, liver and kidney. We also report the early induction (2 h) of equine eotaxin and MCP-4, and the up-regulation of MCP-1 by interleukin-4 in dermal fibroblasts, suggesting these chemokines might be involved in equine skin allergic diseases.

LC-MS-MS to detect and identify four beta-agonists and quantify clenbuterol in liver.

European legislation forbids the use of beta-agonists as growth-promoting substances in cattle raised for human consumption. However, the use of beta-agonists is allowed as a therapeutic treatment of tocolysis for female cattle during calving and of respiratory diseases and tocolysis for horses not raised for human consumption. A maximum residue limit (MRL) of 0.5 microgram kg-1 for clenbuterol in the liver of cattle and horses is proposed by law. Residues of beta-agonists in liver are identified with LC-MS-MS. Using ion trap technology, it was possible to identify each analyte without the need to resolve completely the chromatographic peaks. For each analyte, specific fragment ion spectra were obtained. The coeluting or incompletely resolved peaks were separated mass spectrometrically. For tulobuterol, bromobuterol and mabuterol, qualitative information was obtained. All beta-agonists could be detected up to a concentration of 0.1 microgram kg-1. For clenbuterol, a limited quantitative validation was performed. A working range was defined for which the method was applicable. Quantification was based on the integration of the response of the analytes in spiked blank liver samples. The mean recovery was 15%. The relative standard deviation (RSD) values at different concentrations were below the maximum allowed RSD. The limit of detection of clenbuterol was 0.11 microgram kg-1. The limit of quantification was 0.21 microgram kg-1. It was possible to quantify clenbuterol below one-half of the MRL. The advantage of this method is the ease of use of the mass spectrometric separation to qualify and quantify the presence of four beta-agonists in liver.

Age-related storage of iron in the liver of horses.

The non-haem iron concentration was estimated in post-mortem liver samples from 51 horses (age range 1-25 years). Two were normal and 49 had been suffering from conditions that were not expected to have had long-term effects on iron metabolism. Muscle samples (splenius and biceps femoris) from 23 of these horses were also analysed. There was a highly significant age-related increase in the non-haem iron concentration in the liver (r = 0.635, p < 0.001), but not in the muscles, in which the iron concentration was much lower than in the liver.

The lead status of horses from central Europe depending on breed, sex, age and living area.

The breed of horses took a significant effect on the Pb content of animals with a normal Pb supply. Warm-blooded horses stored more Pb in skeleton, kidneys, liver and cerebrum than heavy horses. The sex only had the trend of influencing the Pb status. Mares with a normal Pb supply incorporated more Pb than geldings. Age only took a slight effect on the skeleton. Older horses stored more Pb in the metatarsal bone than younger ones. The Pb content of horse meat was not influenced by Pb exposure. Pb was not additionally deposited in the musculature. The Pb offer of the living area took a significant effect on the Pb status of horses. Skeleton, liver and kidneys indicated the site-specific influences significantly.

Age dependent changes in metallothionein and accumulation of cadmium in horses

1. Analysis of livers and kidneys from 28 horses for cadmium, zinc and metallothionein showed low cadmium content in liver. There was a gradual increase in cadmium content in kidney with age. 2. Metallothionein values varied with zinc content in the liver and with cadmium content in the kidney; copper values did not vary in either tissue. 3. Metallothionein was localized mainly in the cytoplasm in liver and kidney of horses by immunohistochemistry.

Investigations into heavy metal contents in the meat and organs of edible animals

The lean meat, heart, lung, liver, kidney cortex, kidney medulla, small intestine, and spleen from 20 cattle, 20 sheep, 20 swine, and 20 horses were examined for zinc, copper, manganese, nickel, chromium cadmium, lead, and arsenic. The fodders for cattle, swine, horses were also examined for zinc, copper, manganese and cadmium. This was done to discover the usual heavy metal values of edible animals with a view to determining whether age, breed, management, or feeding have any effect on the distribution of the metals in the animals, and to study the contribution by meat to the heavy metal uptake of man through food. The following results were obtained:1) Large amounts of most metals were found in the storage organs, liver and kidney.2) The cadmium contents in all the tissues of horses were 15-70 times as high as cattle, swine and sheep.3) In horses the observed ratios (metal contents in tissue/metal contents in fodder for each animal) of metal were definitely higher; the bovine livers having copper ratios of 9.5, and the livers and kidneys of horses having cadmium ratios of 26.5 and 277, i.e., 10-50 times as high as in other animals.4) The cadmium concentrations in the majority of tissues showed a tendency to increase with advancing age. Breed differences in the manganese concentration were noticed in cattle and horses.5) The mean lead and arsenic concentrations in all samples were less than 0.1μg/g wet weight, and lead levels in the liver and kidney of all animals were lower than in European animals.6) The meats were fit for human consumption with the exception of the liver and kidney of horses.

The effect of phenobarbital, dieldrin, DDT, and benzene hexachloride on hepatic aminopyridine N-demethylase in horses, cattle and sheep

The daily oral administration of phenobarbital sodium stimulated aminopyrine N-domethylase activity in the liver of sheep and horses, and the induced activity fell rapidly when dosing ceased. In sheep, calves, and horses, a single oral dose of dieldrin induced a high level of enzyme activity which persisted for several months. Single oral doses of DDT and benzene hexachloride (BHC) had the same effect in sheep and horses but DDT had no effect in calves and BHC was inconsistent, causing a stight stimulation of enzyme activity in some calves but not in others. This lack of effect may be due to the more rapid metabolism of DDT by cattle. It is also suggested that the exposure of animals to single oral doses of chlorinated hydrocarbons may, by the induction of hepatic drugmetabolizing enzyme activity, alter the animals' susceptibility to other drugs encountered accidentally or administered for therapeutic purposes.

Mineral Composition of the Whole Body, Liver and Bone of Young Horses

Mineral Composition of the Whole Body, Liver and Bone of Young Horses

Omega hydroxy fatty acid dehydrogenase

1. 1. A DPN-dependent dehydrogenase which catalyzes the oxidation of C 9, C 10, and C 11 omega hydroxy fatty acids was extracted from hog liver. The postulated product of the oxidation, omega oxo fatty acid, reversed the reaction in the presence of the purified enzyme. 2. 2. The 200-fold purified dehydrogenase was specific for fatty acid alcohols of the medium molecular weight (C 9–C 11). This system is not active with very low (C 1–C 4) or very high molecular weight (C 18) omega hydroxy acids or with a variety of the primary alcohols which do or do not have additional functional groups, i.e., amino, carboxy, or a second hydroxyl. Secondary fatty acid alcohols were also unaffected. 3. 3. As judged by the spectrophotometric assay, the omega fatty acid dehydrogenase is present also in extracts of heart and kidney of hog and the liver of sheep, rats, and horses. 4. 4. The possible relationship of this enzyme to omega oxidation is discussed briefly.

Diseases Affecting the Liver of Horses

Diseases Affecting the Liver of Horses