IFN‐τ Acts in a Dose‐Dependent Manner on Prostaglandin Production by Buffalo Endometrial Stromal Cells Cultured in vitro

Interferon‐τ (IFN‐τ) has been recognized as the primary embryonic signal responsible for maternal recognition of pregnancy. Uterine endometrium produces both prostaglandin F_2α (PGF_2α) and prostaglandin E₂ (PGE₂). PGF_2α is responsible for the luteolysis; however, PGE₂ favours establishment of pregnancy by its luteoprotective action. In this study, the dose‐response effect of recombinant bovine IFN‐τ (rbIFN‐τ) on prostaglandin (PG) production by buffalo endometrial stromal cells cultured in vitro was studied. Buffalo endometrial stromal cells were isolated by double enzymatic digestion, initially with trypsin III followed by a cocktail of trypsin III, collagenase type II and DNase I and subsequently cultured till confluence. Further, cells were treated with different doses of rbIFN‐τ (0.001, 0.01, 0.1, 1.0 and 10 μg/ml) and keeping a separate set of control. Culture supernatant was collected after 6, 12 and 24 h of treatment. PG levels in the culture supernatant were measured by enzyme immune assay (EIA) and total cellular protein estimated by Bradford method. Results indicated that buffalo endometrial stromal cells following rbIFN‐τ treatment enhanced the secretion of both PGE₂ and PGF_2α, and also its ratio in a strict dose‐dependent manner with a significant increase (p < 0.01) in PGE₂ production at 1 μg/ml dose of rbIFN‐τ and maximal stimulation for both PG was observed at 10 μg/ml. Further, both PG production and its ratio were increased significantly (p < 0.01) in a time‐dependent fashion in all the groups at 6, 12 and 24 h post‐treatment with highest level achieved at 24 h as compared with control. Absolute levels of PGE₂ remained higher than PGF_2α indicating PGE₂ as the major PG produced by endometrial stromal cells. The dose‐dependent response of rbIFN‐τ signifies the importance of optimum concentration of IFN‐τ for the embryonic development especially during the critical period to establish successful pregnancy.     

Identification of a Kunitz-type proteinase inhibitor from Pithecellobium dumosum seeds with insecticidal properties and double activity

A trypsin inhibitor, PdKI, was purified from Pithecellobium dumosum seeds by TCA precipitation, trypsin-sepharose chromatography, and reversed-phase-HPLC. PdKI was purified 217.6-fold and recovered 4.7%. SDS-PAGE showed that PdKI is a single polypeptide chain of 18.9 kDa and 19.7 kDa by MALDI-TOF. The inhibition on trypsin was stable in the pH range 2-10 and at a temperature of 50 degrees C. The Ki values were 3.56 x 10(-8)and 7.61 x 10(-7) M with competitive and noncompetitive inhibition mechanisms for trypsin and papain, respectively. The N-terminal sequence identified with members of Kunitz-type inhibitors from the Mimosoideae and Caesalpinoideae subfamilies. PdKI was effective against digestive proteinase from Zabrotes subfasciatus, Ceratitis capitata, Plodia interpunctella, Alabama argillaceae, and Callosobruchus maculatus, with 69, 66, 44, 38, and 29% inhibition, respectively. Results support that PdKI is a member of the Kunitz inhibitor family and its insecticidal properties indicate a potent insect antifeedant.     

Efficacy of ivermectin controlled-release capsules for the control and prevention of nasal bot infestations in sheep

Objective To investigate the therapeutic and prophylactic efficacy of an ivermectin controlled-release capsule against nasal bots (Oestrus ovis) in sheep.
Design Trial 1 – A pen study with controls. Trial 2 – A field study with controls.
Animals Trial 1 – Forty Merino wethers with natural infestations of nasal bot were used. Trial 2 – One hundred nasal bot-free wethers were used.
Procedure Trial 1 – Ten randomly selected animals were slaughtered and the heads split and examined to confirm bot infestation. Fifteen animals were allocated to untreated controls and 15 to treatment with a controlled-release capsule delivering ivermectin at ≥ 20 μg/kg/day for 100 days. Twenty-nine days after treatment the sheep were killed and examined for nasal bots. Trial 2 – Nasal bot-free sheep were allocated to two groups of 45 animals. One group was untreated the other sheep were treated with capsules as above. The sheep were grazed as a single group exposed to natural challenge from O ovis . Ninety days after treatment the animals were slaughtered and examined for nasal bot infestation.
Results Trial 1 – Live O ovis larvae were recovered from 60% of control sheep. No live larvae were collected from treated sheep. Trial 2 – Forty-one percent of untreated sheep harbored nasal bot infestations. No live larvae were collected from any treated animal.
Conclusion Treatment with a single ivermectin controlled-release capsule was 100% effective against existing infestations of O ovis and as a prophylactic treatment for this parasite.     

Gram-negative bacterial infections and cardiovascular parasitism in green sea turtles (Chelonia mydas)

Objective To investigate causes of ill health and mortality in juvenile wild green sea turtles ( Chelonia mydas ) found along the mid-north west coast of Western Australia between June and October of 1997.
Procedure Department of Conservation and Land Management rangers submitted four dead or dying green sea turtles from separate incidents for veterinary examination, necropsy, and bacteriological, parasitological and histopatho-logical examination.
Results Numerous different species of trematodes belonging to the families Pronocephalidae, Microscaphidiidae and Paramphistomidae were detected in the intestines of two turtles examined, and in all turtles there was severe spirorchid fluke infection including Haemoxenicon sp, Amphiorchis sp and Hapalotrema sp. Histopathological examination demonstrated severe multifocal to diffuse granulomatous vasculitis, aggregations of spirorchid fluke eggs and microabscesses throughout various tissues including intestines, kidney, liver, lung and brain. Cultures and or histopathological examination demonstrated disseminated Gram-negative bacterial infections including salmonella, E coli , Citrobacter freundii and Moraxella sp.
Conclusion Infections caused by salmonellae, E coli and other Gram-negative bacteria should be considered as causes of systemic illness and death in wild green sea turtles infected with spirorchid cardiovascular flukes and other internal parasites.     

Fluorescent Stain Method for the Simultaneous Determination of Mitochondrial Potential and Integrity of Plasma and Acrosomal Membranes in Boar Sperm

The purpose of this study was to validate a technique for simultaneous evaluation of the plasma, acrosomal and mitochondrial membranes in boar spermatozoa, using an association of fluorescent probes: Propidium iodide (PI), fluorescein isothiocyanate-conjugated Pisum sativum agglutinin (FITC-PSA) and JC-1. Three ejaculates from each of four different boars, all showing motility >or=80% and abnormal morphology 相似文献   

Serological response to Actinobacillus pleuropneumoniae serovar 7 infection in a commercial pig herd

Serological responses to Actinobacillus pleuropneumoniae serovar 7 infection were monitored by enzyme-linked immunosorbent assay in a cohort of 66 pigs between weaning and market. Antibody concentrations were high (63/65 seropositive) at 4 weeks of age but declined to low levels from 8 to 12 weeks. Mean antibody concentrations rose significantly (p less than 0.001) between 12 and 23 weeks. Between 8 and 23 weeks of age, 33 (51.5%) of 64 surviving pigs seroconverted to A pleuropneumoniae serovar 7. Peak antibody concentrations in the seroconverting pigs usually (28/33) occurred at 23 weeks. Seroconversion to A pleuropneumoniae during the grower/finisher phase was not significantly associated (p greater than 0.05) with passive antibody concentrations at 4 weeks of age, lack of vaccination against Mycoplasma hyopneumoniae, or weaning weight. Pleuropneumonic lesions were evident at slaughter in 4 (6.3%) of 64 pigs. A pleuropneumoniae serovar 7 was isolated from 2 of 4 lungs with pleuropneumonia and from another lung with lesions considered typical of enzootic pneumonia.     

Effect of Antioxidants During Bovine In Vitro Fertilization Procedures on Spermatozoa and Embryo Development

Increased amounts of reactive oxygen species (ROS) during in vitro fertilization (IVF) may cause cytotoxic damage to gametes, whereas small amounts of ROS favour sperm capacitation. The aim of this study was to investigate the effect of antioxidants [50 μ m β-mercaptoethanol (β-ME) and 50 μ m cysteamine (Cyst)] or a pro-oxidant (5 m m buthionine sulfoximine) on the quality and penetrability of spermatozoa into bovine oocytes and on the subsequent embryo development and quality when added during IVF. Sperm quality, evaluated by the integrity of plasma and acrosomal membranes, and mitochondrial function, was diminished (p < 0.05) after 4-h culture in the presence of antioxidants. Oocyte penetration rates were similar between treatments (p > 0.05), but antioxidants adversely affected the normal pronuclear formation rates (p < 0.05). The incidence of polyspermy was high for β-ME (p < 0.05). No differences were observed in cleavage rates between treatments (p > 0.05). However, the developmental rate to the blastocyst stage was adversely affected by Cyst treatment (p < 0.05). The quality of embryos that reached the blastocyst stage, evaluated by total, inner cell mass (ICM) and trophectoderm cell numbers and ICM/total cell ratio was unaffected (p > 0.05) by treatments. The results indicate that ROS play a role in the fertilizing capacity in bovine spermatozoa, as well as in the interaction between the spermatozoa and the oocytes. It can be concluded that supplementation with antioxidants during IVF procedures impairs sperm quality, normal pronuclear formation and embryo development to the blastocyst stage.