Grazing‐induced changes in muscle microRNA‐206 and ‐208b expression in association with myogenic gene expression in cattle

To investigate the roles of microRNAs (miRNAs) in muscle type conversion, the effects of 4 months of grazing on the expression levels of miRNAs and mRNAs associated with skeletal muscle development were analyzed by quantitative RT‐PCR using the Biceps femoris muscle of Japanese Shorthorn cattle. After 4 months of grazing, the expression of muscle fiber type‐associated miR‐208b was higher in the grazed cattle than in the housed. In concordance with the pattern in miR‐208b expression, the expression of MyoD, a myogenic regulatory factor associated with the shifting of muscle property to the fast type, was lower in the grazed cattle after 4 months of grazing than in the housed cattle. In addition, the expression of MyHC‐2x (a fast type) was higher in the housed cattle than in the grazed, after 4 months of grazing. During the grazing period, miR‐206 expression decreased in the housed cattle, whereas expression in the grazed cattle did not change, but rather remained higher than that of the housed cattle even at 3 months after the grazing ended. These miRNAs including miR‐206 persisting with muscles of grazed cattle may be associated with regulation of muscle gene expression during skeletal muscle adaptation to grazing.     

Synthetic microRNA‐205 exhibited tumour suppression in spontaneous canine malignant melanoma by intratumoral injection

MicroRNAs (miRNA) are small, noncoding RNA molecules consisting of 18 to 25 nucleotides. Malignant melanomas (MMs) are one of the most common malignancies in both dogs and humans. We previously reported that chemically modified synthetic miRNA‐205 (miR‐205BP/S3) inhibits melanoma growth in vitro and in vivo. The present study aimed to evaluate the efficacy of intratumoral administration of synthetic miR‐205 for spontaneous CMMs and to evaluate its potential as systemic therapy. Ten dogs with various stages of MM were treated with miR‐205BP/S3 injected into tumours. Adverse effects (AEs) were assessed in accordance with the Veterinary Cooperative Oncology Group‐Common Terminology Criteria for Adverse Events (VCOG‐CTCAE) v1.1 guidelines. Five cases attained complete remission (CR), three attained stable disease (SD), and two cases displayed characteristics of progressive disease (PD). In all cases, no changes were observed in the blood parameters upon miRNA administration, and miR‐205BP/S3 administration did not yield any side effects. The present results suggest that intratumoral administration of miR‐205BP/S3 is a potentially applicable treatment for canine melanoma.     

Alterations in lycopene concentration and Z‐isomer content in egg yolk of hens fed all‐E‐isomer‐rich and Z‐isomer‐rich lycopene

Effects of feeding lycopene isomers to laying hens on egg qualities such as lycopene concentration and color of the yolk were investigated. Firstly, to evaluate the dietary transfer of lycopene to egg yolk, (all‐E)‐lycopene–rich diets (lycopene content, 100, 200, or 300 mg/kg diet) were fed to hens for 21 days. Lycopene in egg yolk could be detected after 4 days or more from the start of feeding, and the lycopene concentration increased according to the feed amount and period. Even though most of the dietary lycopene was the all‐E‐isomer, more than 65% of lycopene in egg yolk was present as Z‐isomers. Thus, the effect of lycopene Z‐isomer content in the diet (lycopene content, 200 mg/kg diet; lycopene Z‐isomer content, 35.1% or 61.3%) on egg qualities was investigated. As the Z‐isomer content increased, the lycopene concentration in the egg yolk increased, for example, when fed a diet rich in Z‐isomers (61.3%), the lycopene concentration in the egg yolk was approximately three times higher than when fed the (all‐E)‐lycopene–rich diet for 21 days. The results indicated that Z‐isomers of lycopene had higher bioavailability and/or higher transfer efficiency to the egg yolk than the all‐E‐isomer.     

Within‐ and across‐breed imputation of high‐density genotypes in dairy and beef cattle from medium‐ and low‐density genotypes

The objective of this study was to evaluate, using three different genotype density panels, the accuracy of imputation from lower‐ to higher‐density genotypes in dairy and beef cattle. High‐density genotypes consisting of 777 962 single‐nucleotide polymorphisms (SNP) were available on 3122 animals comprised of 269, 196, 710, 234, 719, 730 and 264 Angus, Belgian Blue, Charolais, Hereford, Holstein‐Friesian, Limousin and Simmental bulls, respectively. Three different genotype densities were generated: low density (LD; 6501 autosomal SNPs), medium density (50K; 47 770 autosomal SNPs) and high density (HD; 735 151 autosomal SNPs). Imputation from lower‐ to higher‐density genotype platforms was undertaken within and across breeds exploiting population‐wide linkage disequilibrium. The mean allele concordance rate per breed from LD to HD when undertaken using a single breed or multiple breed reference population varied from 0.956 to 0.974 and from 0.947 to 0.967, respectively. The mean allele concordance rate per breed from 50K to HD when undertaken using a single breed or multiple breed reference population varied from 0.987 to 0.994 and from 0.987 to 0.993, respectively. The accuracy of imputation was generally greater when the reference population was solely comprised of the breed to be imputed compared to when the reference population comprised of multiple breeds, although the impact was less when imputing from 50K to HD compared to imputing from LD.     

Effects of N‐acetyl‐cysteine and N‐acetyl‐cysteine‐amide Supplementation on In Vitro Matured Porcine Oocytes

This study was conducted to evaluate the effects of different concentrations of the antioxidant N‐acetyl‐cysteine (NAC) supplemented to the maturation medium on porcine embryo development. Concentrations of NAC and its synthetic derivative, NAC‐amide (NACA) were evaluated for effects on nuclear maturation, fertilization success and embryo development. Concentrations of NAC (0, 0.5, 1.0, 1.5, 2.0, 2.5 and 5.0 mm ) were supplemented to maturing oocytes, and embryo development was analysed at 48 and 144 h post‐fertilization. There were no differences among cleavage rates for any of the treatment groups. Blastocyst formation for 1.5 mm NAC (56.5 ± 9.2%) was higher (p < 0.05) than all other supplementations. There were no differences in nuclear maturation or fertilization or in cleavage rates when comparing 1.5 mm NAC and 1.5 mm NACA supplementation to the control. Blastocyst formation for 1.5 mm NAC (44.4 ± 4.7%) and 1.5 mm NACA (46.2 ± 3.4%) supplementation were higher (p < 0.05) than the control (32.1 ± 6.2%) oocytes. These results indicate that supplementing 1.5 mm of NAC or NACA to the oocyte maturation medium increased the percentage of viable embryos reaching the blastocyst stage of development.     

Bone biomarkers and risk of fracture in two‐ and three‐year‐old Thoroughbreds

The aim of this study was to determine whether bone biomarkers (osteocalcin, PICP, ICTP and CTX‐I) could be used to identify 2‐ and 3‐year‐olds at increased risk of fracture in the subsequent flat racing season. It was concluded that these bone biomarkers cannot be used to identify 2‐ and 3‐year‐olds that sustain a fracture. Whether bone biomarkers have better predictive value in older horses or when measured serially in the same animal remains to be determined.     

Fasting Urinary Calcium‐to‐Creatinine and Oxalate‐to‐Creatinine Ratios in Dogs with Calcium Oxalate Urolithiasis and Breed‐Matched Controls

Background

Hypercalciuria and hyperoxaluria are risk factors for calcium oxalate (CaOx) urolithiasis, but breed‐specific reports of urinary metabolites and their relationship with stone status are lacking.

Objective

To compare urinary metabolites (calcium and oxalate) and blood ionized calcium (iCa) concentrations between CaOx stone formers and breed‐matched stone‐free controls for the Miniature Schnauzer, Bichon Frise, and Shih Tzu breeds.

Animals

Forty‐seven Miniature Schnauzers (23 cases and 24 controls), 27 Bichons Frise (14 cases and 13 controls), and 15 Shih Tzus (7 cases and 8 controls).

Methods

Prospective study. Fasting spot urinary calcium‐to‐creatinine and oxalate‐to‐creatinine ratios (UCa/Cr and UOx/Cr, respectively) and blood iCa concentrations were measured and compared between cases and controls within and across breeds. Regression models were used to test the effect of patient and environmental factors on these variables.

Results

UCa/Cr was higher in cases than controls for each of the 3 breeds. In addition to stone status, being on a therapeutic food designed to prevent CaOx stone recurrence was associated with higher UCa/Cr. UOx/Cr did not differ between cases and controls for any of the breeds. Blood iCa was higher in cases than controls in the Miniature Schnauzer and Bichon Frise breeds and had a moderate correlation with UCa/Cr.

Conclusions and Clinical Importance

Hypercalciuria is associated with CaOx stone status in the Miniature Schnauzer, Bichon Frise, and Shih Tzu breeds. UOx/Cr did not correlate with stone status in these 3 breeds. These findings may influence breed‐specific stone prevention recommendations.     

State‐of‐the‐Art‐Review: Immunomodulatory effects of opioids

Objective – To review the immunomodulatory effects of opioids. Data Sources – Original research publications and review articles using the PubMed search engine with the following keywords – opioids, morphine, immuomodulation, and immunosuppression. Veterinary and Human Data Synthesis – Opioids have been shown to modulate the immune system in animal models by affecting both the acquired and innate arms of the immune system. Natural killer cell activity, T‐cell proliferation, antibody production, phagocytic cell function, and cytokine production have all been shown to be affected by opioids. Many of these effects are reversed by opioid antagonists. Opioids have also been shown to induce sepsis in laboratory animals. Opioid administration alters immune parameters in healthy humans at analgesic doses and may increase the risk of infection in some patient populations. Conclusions – While opioids remain the most powerful and widely used analgesics available, their negative effects on the immune system are well established in the laboratory setting. Thoughtful consideration should be given to the use of certain opioids in critically ill patients, especially those with pre‐existing immunocompromise.     

Hypothalamo‐pituitary‐adrenocortical axis in stress‐susceptible and stress‐resistant pigs: endocrine responses to corticotrophin‐releasing factor and vasopressin*

Swiss Landrace pigs selected into genetically well‐characterized low and high tissue fat lines (f and F respectively) react differently to exogenous and endogenous stressors. Response of the hypothalamo‐pituitary‐adrenocortical (HPA) axis to i.v. administered ovine corticotrophin‐releasing factor (oCRF) and lysine vasopressin (LVP) in young females, intact and pretreated with dexamethasone or metyrapone, leads to the conclusion that different stress susceptibility of the two lines correlates with the sensitivity of pituitary corticotrophs to oCRF stimulation. Total amount of ACTH released after stimulation with submaximal oCRF doses was roughly equal in both lines, and cortisol level is even lower in the f‐line, most likely due to the considerably enhanced metabolic clearance rate of cortisol (lower half‐life of plasma cortisol compared with F‐line). LVP‐stimulated ACTH release is comparable with that of oCRF is stronger in the f‐line. Combined effect of oCRF and LVP is rather additive than synergistic but the half‐life ratio cortisol/ACTH after this stimulation is about four times higher than for stimulation by LVP and oCRF separately. In cases of externally stimulated HPA axis, cortisol plasma concentration tightly cross‐correlates with that of ACTH.