Effects of exogenous progesterone and estrone on conceptus development in swine

Administration of progesterone (P4, .55 mg/kg) and estrone (E1, .275 micrograms/kg) during discrete periods in early gestation was found to have beneficial effects on conceptus development in gilts. Three trials were conducted, with each trial examining two hormone treatment groups and one control group. In all trials, P4-E1 supplementation for either one or both of the time periods examined resulted in larger (P less than .05) placentas at d 50 of gestation. Administration of exogenous P4-E1 from either d 20 to 30 (trial 1) or d 25 to 30 (trial 3) of gestation resulted in the greatest augmentation in placental development. In all three trials, exogenous P4-E1 elicited beneficial effects on areolae formation and development. In all nine groups examined (both P4-E1-treated and controls), a positive uterine artery minus uterine vein difference in progesterone concentration was found. This suggests that the conceptus is metabolizing progesterone to metabolites that may have a local effect within the pregnant uterus. It is suggested that augmentation of placental growth, as demonstrated in this study, may reduce secondary fetal death losses in latter gestation (i.e., post-d 70) due to placental insufficiency.     

Cellular and extracellular vesicular origins of miRNAs within the bovine ovarian follicle

The ovarian follicle components must provide an ideal environment to ensure the success of reproductive processes, and communication between follicular cells is crucial to support proper oocyte growth. Recently, it has been demonstrated that the presence of extracellular vesicles (EVs) carrying microRNAs (miRNAs) in follicular fluid represents an important autocrine and paracrine communication mechanism inside the ovarian follicle. In this study, we tested the hypothesis that the miRNA content of EVs isolated from ovarian follicular (granulosa and cumulus–oocyte complexes) cell‐conditioned culture media is dependent upon cell type. We initially screened bovine granulosa cells (GCs) and cumulus–oocyte complexes (COCs), as well as their derived EVs for 348 miRNAs using real‐time PCR, and detected 326 miRNAs in GCs and COCs cells and 62 miRNAs in GCs and COCs EVs. A bioinformatics analysis of the identified cell‐specific and differentially expressed miRNAs predicted that they likely modulate important cellular processes, including signalling pathways such as the PI3K‐Akt, MAPK and Wnt pathways. By investigating the origins of miRNAs within the follicular fluid, the results of this study provide novel insights into follicular miRNA content and intercellular communication that may be of invaluable use in the context of reproductive technologies, diagnostic of ovarian‐related diseases and/or the identification of biomarkers for oocyte and embryo quality.     

Alternative activation of ruminant macrophages by Fasciola hepatica

The helminth parasite, Fasciola hepatica, has a worldwide distribution and infects a wide variety of mammalian hosts, including ruminants and man. In response to infection, these hosts mount a type 2 helper (Th2) response that is highly polarized and results in the downregulation of type 1 helper (Th1) mechanisms. In a murine macrophage model F. hepatica induces alternative activation of macrophages. These macrophages differ from classically activated cells in that they preferentially use arginase instead of inducible nitric oxide synthase (iNOS) for metabolism of nitrogen. In this study we sought to characterize macrophage phenotype following stimulation of the ovine cell line MOCL7 with recombinant F. hepatica enzymes and crude parasite extracts. An in vitro model using the MOCL7 cell line was established and arginase levels in cells were used to determine the activation status of cells. Stimulation of this cell-line in vitro with F. hepatica products induces alternative activation. We have also found a chitinase-like protein in supernatants which is capable of differentiating alternatively activated from classically activated macrophages.     

Intrahepatic cholestasis in a dog: a clinicopathological study.

The paper describes a case of jaundice in a three-year-old bassett hound. The illness was accompanied by hyperbilirubinaemia and raised serum levels of alkaline phosphatase and glutamic pyruvic transaminase, indicating the presence of both biliary obstruction and hepatocellular damage. Examination of liver biopsies on two occasions showed intrahepatic cholestasis and mild inflammatory change. The dog was treated with corticosteroid. The jaundice regressed after three months, hepatic functions returned to normal and the dog recovered. The cause of the jaundice was not determined.     

Serum and Tissue Steroid Hormone Levels in Canine Mammary Tumours: Clinical and Prognostic Implications

Hormonal dependency of canine mammary tumours (CMT) has been studied over the last few decades. However, studies assessing the prognostic and predictive potential of serum and/or tissue steroid hormone levels are still scarce in CMT. To the best of our knowledge, this is the first report relating serum and tissue levels of steroid hormones and prognosis in dogs. Serum and tumour tissue from 45 female dogs with spontaneous CMT were included in the study. Moreover, serum and normal mammary tissue from 13 healthy female dogs were also included as controls. Steroid hormones were determined by competitive enzyme immunoassay. Overall, levels of steroid hormones in serum and tissue homogenates were significantly different between malignant and benign mammary tumours (p < 0.01), except for progesterone (P4) serum levels that revealed no statistical differences between groups. In malignant tumours, oestrone sulphate (SO4E1), dehydroepiandrosterone (DHEA), androstenedione (A4), testosterone (T) and P4 elevated tissue concentrations were significantly associated with tumour relapse and/or distant metastasis during follow‐up. A significant association was found between elevated tissue SO4E1 (p = 0.003), 17β‐oestradiol (E2) (p = 0.036), DHEA (p = 0.022), A4 (p = 0.001) and P4 (p = 0.013) concentrations and shorter disease‐free survival and overall survival in female dogs with malignant mammary tumours. The high levels of tissue steroids found in cases of poor prognosis open the possibility of additional new therapeutic approaches. Future clinical trials will be needed to clarify the usefulness of targeting steroid hormones in the treatment of this neoplastic disease.     

Prevalence of the causes of fleece derangement among sheep flocks in New South Wales

SUMMARY An investigation of sheep flocks with unknown histories of fleece derangement, selected at random from the main sheep raising areas of New South Wales, showed that Psorergates ovis was present in 53 of the 177 flocks surveyed and In 162 of the 3495 sheep examined. Of the single causes of fleece derangement, the most prevalent was grass seed contamination (15.7%) followed by Infestation with sheep body lice, Bovicola ovis, (14.7%) and Infestation with Itch mite (7.8%). The prevalence of fleece derangement was significantly higher on sheep In which lice were the only ectoparasites found than on those In which Itch mites were the only ectoparasites present. The greatest prevalence of P ovis was In flocks In the Young, Yass, Mudgee and Tenterfield districts. In most affected flocks, more than one potential cause of fleece derangement was present. Itch mite Infestation was more prevalent in flocks that received no treatment for ectoparasites than in those that had been treated in the year preceding the survey. Our results did not support a commonly held belief among farmers that arsenical compounds control Infestations of Itch mites more effectively than other types of pesticides. There was no significant difference in prevalence of fleece derangement between flocks treated with different pesticide groups and those that received no treatment, but mean fleece derangement score was significantly lower in sheep treated with organophosphates than in untreated sheep. Infestations of lice were significantly more prevalent in sheep from flocks treated with synthetic pyrethroids than from those treated with organophosphates or those that received no treatment.     

Cathepsin L proteinases as vaccines against infection with Fasciola hepatica (liver fluke) in ruminants

Fasciolosis, caused by trematodes of the genus Fasciola, is one of the most important diseases of farmed ruminants in temperate and tropical zones. The appearance of Fasciola hepatica populations that are resistant to common flukicidal drugs means that new methods of treatment will soon be required. The future prospect for the development of anti-liver fluke vaccines is optimistic and given their consumer acceptability and environmental friendliness, offer the best way forward. Cathepsin L proteases (Fhe CL 1 and Fhe CL 2), secreted by liver flukes at all stages of their development in the mammalian host, are believed to play important roles in facilitating parasite migration (tissue degradation), feeding and immuno-evasion. The authors consider them prime targets for which new vaccines can be developed. Vaccine studies in cattle and sheep have shown that protection levels of up to 72 and 79 per cent, respectively, can be obtained with immunisations of cathepsin Ls in Freunds' adjuvant. The vaccine also exhibited high anti-embryonation/anti-fecundity effects on parasites that survived in vaccinated animals and thus could have a major impact on the transmission of disease to the intermediate host. While natural infections in sheep and cattle appear to elicit non-protective Th2 immune responses, the authors' studies indicate that the protection induced by vaccination involves elements of a Th1 response.     

Pre-exposure of cattle to drug-abbreviated Fasciola hepatica infections: the effect upon subsequent challenge infection and the early immune response

In this study we examined whether juvenile liver flukes are capable of stimulating protective immune responses in cattle. Four experimental groups of cattle were studied as follows: group A, a positive control, received a primary infection on day 0 and a secondary infection 28 days later; group B also received two infections but the primary infection was terminated by drug treatment on day 5; group C, received infections on days 0, 5 and 10 which were terminated by drug treatments on days 1, 6 and 11 and then a secondary infection on day 28; group D received an infection only on day 28. Juvenile flukes appear to induce protective responses because: (a) group B animals had significantly lower levels of gamma-GT (P<0.05) than group D; (b) both groups B and C exhibited lower parenchymal phase GLDH levels (P=0.006 and 0.041, respectively); and (c) both groups B and C had lower secondary phase eosinophilia (P=0.002 and 0.02, respectively) than those in group D. Sera taken from groups A-C contained antibodies reacting to a variety of proteins in adult fluke somatic antigen and excretory-secretory preparations, particularly to proteins of 52-60, 68-72 and 82-96 kDa. After secondary challenge the antibody responses of group A to these proteins declined while reactivity to proteins of 28-30 kDa increased. Antibody responses to the 28-30 kDa proteins were not detected in groups B-D until 3 weeks later than those observed in group A. Antibody responses to Fasciola hepatica cathepsin L proteases, which are known to induce protection, were monophasic, of the IgG1 isotype only and were not observed prior to secondary challenge in any of the four groups. In contrast, the response to another protective antigen fraction, a high molecular sized haem protein, was of a mixed IgG1/IgG2 nature and was detected within 14 days of primary infection. However, no significant difference in antibody titres to either protein preparation was observed after the secondary infection when groups B and C were compared to group D.