Unusual ovarian activity in a mare preceding the development of an ovarian granulosa cell tumour

An 8-year-old mare, with a foal at foot, was inseminated on foal heat with frozen semen, with the resultant pregnancy lost between days 34 and 41. The right ovary developed a large anovulatory follicle that was non-responsive to multiple doses of ovulating agents. The follicle eventually appeared to luteinise, although plasma progesterone concentrations did not reflect this. Another follicle developed, responded to GnRH and resulted in a pregnancy from frozen semen that went to term with a healthy foal. When the mare was examined after foaling, the structure on the right ovary appeared to be a granulosa cell tumour; the left ovary was smaller than normal and non-functional. Surgical removal of the right ovary before increasing photoperiod resulted in a return to function of the left ovary and a pregnancy to frozen semen on the second cycle following removal. Figures showing concentrations of inhibin, progesterone, androstenedione, oestradiol and testosterone are presented for this entire period. Unusual ovarian activity in the mare might be a prelude to the development of a granulosa cell tumour.     

Contingency and determinism in replicated adaptive radiations of island lizards

The vagaries of history lead to the prediction that repeated instances of evolutionary diversification will lead to disparate outcomes even if starting conditions are similar. We tested this proposition by examining the evolutionary radiation of Anolis lizards on the four islands of the Greater Antilles. Morphometric analyses indicate that the same set of habitat specialists, termed ecomorphs, occurs on all four islands. Although these similar assemblages could result from a single evolutionary origin of each ecomorph, followed by dispersal or vicariance, phylogenetic analysis indicates that the ecomorphs originated independently on each island. Thus, adaptive radiation in similar environments can overcome historical contingencies to produce strikingly similar evolutionary outcomes.     

Occurrence of IgE in foals: evidence for transfer of maternal IgE by the colostrum and late onset of endogenous IgE production in the horse

IgE is the key antibody involved in type I allergies. Allergen mediated crosslinking of IgE bound to high affinity Fc-receptors on mast cells and basophils stimulates cellular degranulation and release of inflammatory mediators and cytokines. In this report, we demonstrate that IgE antibodies can be transferred from the mother to offspring in horses via the colostrum. We found a clear correlation between the IgE concentration in colostrum and the total IgE concentration in foal sera on day 2 after birth (r_sp = 0.83). Maternal IgE was detected in foal sera by ELISA and on peripheral blood leukocytes of foals by flow cytometry. Both serum and cell membrane-bound IgE were undetectable in newborn foals before colostrum uptake and peaked on days 2–5 after birth. Cell-bound IgE became undetectable at 2 months after birth. Serum IgE disappeared from the circulation within the first 3–4 months of age. These kinetics suggest that the IgE antibodies which are detectable in foals during the first 4 months after birth are of maternal origin only. The endogenous IgE production was found to begin at 9–11 months of age, when IgE could be detected on peripheral blood leukocytes and in foal sera again. After 18 months of life, the total IgE concentrations in foal sera were comparable to those detected in their dams. The late onset of endogenous IgE production offers an explanation for observations that IgE mediated allergies are generally not observed in horses before puberty. The roles of the passively transferred maternal IgE in newborn foals are not yet known, but could be manifold, ranging from passive immunity and induction of immunoregulatory functions to determinative influences of maternal IgE on the antibody repertoire in the offspring.     

Further investigation of equine fescue oedema induced by Mediterranean tall fescue (Lolium arundinaceum) infected with selected fungal endophytes (Epichloë coenophiala)

Abstract

AIMS

To determine if equine fescue oedema (EFO) induced by grazing Mediterranean-type tall fescue (Lolium arundinaceum) infected with selected endophytes (Epichloë coenophiala) could be prevented by treatment with the corticosteroid, methylprednisolone, and anti-histamine, cetirizine, and to determine concentrations of lolines, specifically N-acetyl norloline (NANL), in grasses grazed by horses that did and did not develop EFO.     

Bovine-associated MRSA ST398 in The Netherlands

During routinely screening (50.000 milk samples on an annual basis) 14 MRSA ST398 strains were identified in the period of January 2008 to September 2008 in 14 different dairy herds located in the provinces Overijssel and Gelderland, The Netherlands. Molecular analysis was performed by Cfr9I PFGE, ST398-specific diagnostic PCR, spa typing, SCCmec typing and Panton-Valentine Leukocidin (PVL) gene PCR. The molecular analyses of 14 MRSA (one MRSA strain per herd) strains revealed that all strains belong to ST398 with 3 closely related spa types (t011, t108 and t889, all commonly found in pigs) and carry 2 different SCCmec types, IVa and V. All MRSA strains were resistant to two or more classes of antibiotics and also PVL negative. The majority of farms (n = 9, 64%) harboured combined livestock with both cows and pigs present. Our study contributes to the growing evidence that MRSA ST398 is transmitted among various animal species and can be considered as an etiological agent of mastitis in dairy cows.     

Effect of Repeated Stress Treatments During the Follicular Phase and Early Pregnancy on Reproductive Performance of Gilts

In pig husbandry, stress is being considered an important cause of impaired reproductive performance. Therefore, an experiment was performed to quantify effects of repeated stressors during the follicular phase and/or during early pregnancy on reproductive performance of gilts. Eighty-one cyclic gilts were assigned to one of four treatments, namely, stress treatment during the follicular phase (n = 20), stress treatment during early pregnancy (n = 20), stress treatment during both phases (n = 21) and no stress treatment (n = 20). All gilts were housed individually, but gilts in the stress treatments had no opportunity for visual or physical contact with other gilts. Further, animals in a stress-treatment were grouped for half an hour at the start of the treatment and during the treatment period nose-sling and an unpredictable feeding scheme were applied regularly. The extent of stress was monitored using heart rate measurements, behavioural observations and saliva cortisol levels during nose-sling fixation. Of the 81 gilts, 93% showed oestrus and were inseminated. Of these, 93% were pregnant at day 35, having 17.9 +/- 0.3 ovulations and 15.6 +/- 0.3 foetuses. These parameters were not affected by treatment. The stress treatment during the follicular phase tended to shorten cycle length (stress: 20.8 +/- 0.20; control: 21.2 +/- 0.17 days, p = 0.07) and weight of foetuses at day 35 (stress: 4.47 +/- 0.08 g; no stress: 4.69 +/- 0.08 g, p = 0.06); stress during early pregnancy did not affect any of the reproduction parameters. Percentage stereotypic behaviour, heart rate and saliva cortisol levels varied greatly between animals and between days, but did not differ between the treatments. No relationships were found between any of the reproductive parameters and any of the stress parameters (heart rate, cortisol, stereotypic behaviour). These results indicate that the repeatedly applied acute stressors did not generate a chronic stress-response and that these stressors during the follicular phase and/or during early pregnancy did not affect reproductive processes. It is not clear how these findings relate to suggested effects of stress(ors) on reproductive performance in pig husbandry.     

Serum opsonization capacity, phagocytosis, and oxidative burst activity in neonatal foals in the intensive care unit

BACKGROUND: Phagocytic activity of neonatal foals has been reported to be similar to that of adult horses, but serum opsonization capacity develops with age and may be further altered when opsonins are consumed during infection. HYPOTHESIS: Phagocytosis, oxidative burst activity, and serum opsonization capacity in neonatal foals admitted to an intensive care unit are reduced in comparison with control foals. ANIMALS: Blood samples were collected from hospitalized neonatal foals and from control foals. Hospitalized foals were characterized as sick or septic on the basis of a sepsis score and received intravenous plasma transfusion. METHODS: Phagocytosis, oxidative burst activity, and serum opsonization capacity were tested with flow cytometric analysis. Serum immunoglobulin and complement component 3 concentrations were determined with radial immunodiffusion. Serum amyloid A concentration was assayed with a commercially available solid-phase Sandwich ELISA Kit. Data were analyzed with nonparametric and regression methods. Alpha was set at P = .05. RESULTS: Phagocytic functions of septic and sick foals were lower than control foals in the initial phase of the study (P = .01). Opsonization capacity was significantly higher when bacteria were opsonized with serum from septic (P = .029) and sick (P = .006) foals than from control foals on day 1. Opsonization capacity in septic foals was comparable with control foals on days 2 and 5. This effect was not accompanied by an increase in serum complement C3 or immunoglobulin G concentrations independently. CONCLUSIONS AND CLINICAL IMPORTANCE: Our results suggest that phagocytic function could be decreased in hospitalized foals. The synergistic effect of opsonic elements provided by plasma transfusion may sustain opsonization capacity during sepsis.     

Comparison of a competitive inhibition ELISA and the card agglutination test for detection of antibodies to Anaplasma marginale and Anaplasma centrale in cattle

OBJECTIVE: To compare a recently developed recombinant MSP-5 competitive inhibition ELISA with a card agglutination test for detection of antibodies to Anaplasma marginale and Anaplasma centrale in Australian cattle. MATERIALS AND METHODS: The ELISA was compared with the card agglutination test using 208 sera from cattle in Anaplasma-free herds, 86 sera from cattle experimentally infected with A marginale or A centrale and 757 sera from cattle in areas endemic for A marginale. RESULTS: The specificity of the ELISA, based on testing 208 sera from cattle in Anaplasma-free areas, was 99.5%, and the sensitivities for detection of antibodies to A marginale and A centrale in sera from the experimentally infected cattle were 98.0% and 100%, respectively. For the same sets of sera, the specificity of the card agglutination test was 98.6% and the sensitivities for detection of antibodies to A marginale and A centrale were 98.0% and 100%, respectively. For the 757 sera collected from cattle in areas endemic for A marginale, the agreement between the ELISA and the card agglutination test depended on the positive threshold selected for the ELISA. The maximum achievable agreement was 91.5% (kappa = 0.73; 95% confidence interval 0.66, 0.79). CONCLUSION: We conclude that the competitive inhibition ELISA is a useful alternative to the card agglutination test for detection of A marginale or A centrale infection in cattle. The assay should be particularly useful for epidemiological applications such as prevalence studies and control programs.