Relationship Between Motility and Mitochondrial Functional Status in Canine Spermatozoa

Inner mitochondrial membrane potential (IMM) is considered a sensitive indicator for the energetic status and motility of spermatozoa. The relationship between sperm motility parameters evaluated by Computer Assisted Sperm motility Analyzer and plasma membrane integrity and IMM assessed by triple staining (PI/SYBR-14 and JC-1) was evaluated in 10 dogs of unknown fertility. Sperm motility showed large variations ranging from 10% to 98%. Proportion of viable sperm cells and of spermatozoa with high IMM ranged from 74% to 99% and from 53% to 87%, respectively. The presence of a high IMM assessed by JC-1 was more strongly correlated to sperm viability ( r  = 1) than to sperm motility ( r  = 0.778). Our results indicate that JC-1 is suitable for detection of IMM changes in canine spermatozoa, but it should always be associated with an objective motility analysis to avoid incorrect evaluation of potential sperm fertility. Ejaculates with a low motility rate showed an unexpectedly high proportion of sperm with high IMM, suggesting that mitochondrial respiration could not be sufficient to support sperm motility, although it may be important for sperm survival in the female genital tract.     

Characterization of β-haemolytic Group B Streptococcus agalactiae in cultured seabream, Sparus auratus L., and wild mullet, Liza klunzingeri (Day), in Kuwait

Streptococcus agalactiae was isolated from cultured gilthead seabream, Sparus auratus L., and diseased wild Klunzinger's mullet, Liza klunzingeri (Day), in Kuwait Bay, Arabian Gulf. Isolates were catalase negative, β‐haemolytic, Gram‐positive cocci and serogroup B. Experimental infectivity trials with mullet and seabream brain isolates in Nile tilapia, Oreochromis niloticus L., caused 100 and 90% mortality, respectively, within 7 days post‐inoculation indicating virulent S. agalactiae as the bacterial pathogen responsible for the epizootic in Kuwait Bay.     

Modulation of Glycolysis and the Pentose Phosphate Pathway Influences Porcine Oocyte In Vitro Maturation

Glycolytic and pentose phosphate pathway (PPP) activities were modulated in porcine cumulus–oocyte complexes (COCs) during in vitro maturation (IVM) by the addition of inhibitors or stimulators of key enzymes of the pathways to elucidate their relative participation in oocyte maturation. The activities of glycolysis and PPP were evaluated by lactate production per COC and by the brilliant cresyl blue test, respectively. Glucose uptake per COC and the oocyte maturation rate were also evaluated. Lactate production, glucose uptake and the percentage of oocytes reaching metaphase II decreased in a dose‐dependent manner in the presence of the pharmacological (NaF) or the physiological (ATP) inhibitors of glycolysis (p < 0.05). The addition of the physiological stimulator of glycolysis (AMP) caused no effect on lactate production, glucose uptake or the meiotic maturation rate. The pharmacological (6‐AN) and the physiological (NADPH) inhibitors of PPP induced a dose‐dependent decrease in the percentage of oocytes with high PPP activity and in the nuclear maturation rate (p < 0.05). The physiological stimulator of PPP (NADP) caused no effect on the percentage of oocytes with high PPP activity. The glycolytic and PPP activities of porcine COCs and maturational competence of oocytes seem to be closely related events. This study shows for the first time the regulatory effect of ATP and NADPH as physiological inhibitors of glycolysis and PPP in porcine COCs, respectively. Besides, these pathways seem to reach their maximum activities in porcine COCs during IVM because no further increases were achieved by the presence of AMP or NADP.     

Antagonistic effect of soil rhizosphere microorganisms on Bipolaris sorokiniana,the causal agent of wheat seedling blight

The biocontrol efficiency of Epicoccum purpurascens, Gliocladium roseum, three strains of Bacillus subtilis, and Pseudomonas fluorescens, isolated from the rhizosphere of wheat plants, was assessed in relation to seedling blight caused by Bipolaris sorokiniana. An in vitro study of the potential antagonist was performed using the dual culture technique and by ‘sowing’ wheat seeds pelleted with the saprophytes in plates with water agar?+?the pathogen. In vivo assays were carried out in the greenhouse and in the field with pelleted seeds sown in artificially infested soil. Both the number of living plants and the number of plants with necrosis on the leaves and the base of the stems and roots were assessed 15 days after sowing. Under greenhouse conditions, B. subtilis 3 and G. roseum reduced the level of infection of Buck Pucará and Trigomax 100 cultivars, respectively. In the field, biocontrol of the disease was not achieved.     

Development and validation of a novel laboratory model of sound-induced fear and anxiety in Beagle dogs

Disorders of fear and anxiety are significant behavioral and physiological concerns in veterinary medicine. Thus, the present studies sought to develop and validate novel preclinical laboratory models for the development of anxiolytics for the veterinary market. Specifically, noise-induced sensitivity and aversion using thunderstorm recordings on an open-field task in Beagle dogs was used to establish this model. This thunderstorm task was based on the open-field tests previously described for the dog, except that a thunderstorm recording, compiled from desensitization compact discs, played during the middle of the test was used to elicit anxious or fearful responses in laboratory dogs. Initially, we compared the behavioral response on this test with that on an open-field test, in which no sound stimulus was provided. When compared with the open field, the thunderstorm recording increased inactivity duration and frequency, which was related to freezing behaviors and near-door duration. This suggests that we can objectively characterize a fear and anxious response to noise. We then attempted to pharmacologically validate this model by testing 0.5, 1, or 2 mg/kg doses of diazepam on this behavioral outcome. In test-naïve subjects, diazepam reduced the increase in inactivity seen at washout compared with that seen at baseline, suggesting that this paradigm may be useful for establishing the effect of drugs that reduce or prevent sensitization to fear-invoking events. In test-experienced subjects, diazepam reduced inactivity compared with both baseline and washout, indicating that this model may be useful for screening drugs counteracting fear and phobia, as well as anticipatory anxiety responses. Interestingly, diazepam stimulated behavioral activity as measured with the Actiwatch method. The test described here provides a laboratory method for testing therapeutics targeted at reducing either anxiety or fear related to noise sensitivity and aversion in pet dogs.     

Description and taxonomic discussion of eimerian coccidia from African and Levantine geckoes

new genera are proposed to accomodate new and previously described species of eimerian coccidia from reptiles which undergo endogenous development either in the bile epithelium — Cholo?imoria n. gen., or in the microvillous zone of the intestinal epithelium — Acroeimeria n. gen. Endogenous development is described from 3 species, all from geckoes: C. turcicus (syn. Eimeria turcicus Upton, McAllister and Freed, 1988) from Hemidactylus turcicus in Israel; C. pachydactyli n. sp. from Pachydactylus capensis in South Africa and A. lineri (syn. Eimeria linen McAllister, Upton and Freed, 1988) from H. turcicus, Israel and H. mabouia, South Africa. Biliary epithelial cells infected by Chole?imeria become hypertrophic and are displaced to the surface of the epithelial layer. Oocysts are cyllndroid to oval, lack a stieda body and sporulate in the gall bladder. The developing endogenous stages of Acroeimeria, enclosed in the microvillous border of the host cell, expand into the intestinal lumen. Oocysts are oval-spherical, lack a stieda body and sporulation is exogenous.     

The use of irradiated embryos of Chrysomya bezziana for the detection of the Old World screw-worm fly

Irradiation of Chrysomya bezziana embryos 1 h before hatching with doses less than or equal to 7 kilorad (kr) had a significant effect on percentage egg hatch, weights and survival of larvae. Doses greater than or equal to 1 kr allowed larval development to the end of the 3rd instar stage in vitro, but prevented normal pupal development. Cattle with wounds infested with 1st instar larvae derived from irradiated embryos had 3rd instar larvae present after 3 d but these failed to pupate. Thus it would be feasible to use such larvae for wound infestation for the enhanced detection of screw-worm fly in areas where the release of fertile flies is undesirable.     

Prognostic factors for recovery from coxo-femoral dislocation in cattle

Details were recorded of 47 cases of coxo-femoral dislocation observed in cattle over 1 year. Treatment was successful in 20/47 (42.6%) cases using a method of closed reduction. Factors that most strongly influenced the prognosis were identified. The most useful single prognostic factor was whether the cow was able to stand before reduction. Other factors that also had a strong positive influence on the prognosis were: age less than 3y, bodyweight less than 400kg and duration of dislocation less than 12h. Nineteen unsuccessful cases were examined at the knackery. Four were found to have a fracture of the proximal femur. The coxo-femoral joint was carefully dissected in the other 15 cases and there was no evidence of hip dysplasia. A seasonal incidence of dislocations, which coincides with the calving and mating periods, was demonstrated during the survey and from practice records for the previous 3 years.     

Effects of Storing Pig Ovaries at 4 or 20°C for Different Periods of Time on the Morphology and Viability of Pre-Antral Follicles

The purpose of this study was to evaluate the effect of cooling ovarian tissue on pig pre-antral follicles. Ovaries were maintained in saline solution (0.9%) at 4 or 20 degrees C for 6, 12 or 18 h. After storage, pre-antral follicles were morphologically evaluated. While primordial follicles were not affected by the storage, the percentage of morphologically normal growing follicles was significantly reduced in ovarian tissue stored at 20 degrees C for 12 or 18 h. To test the viability of stored follicles, growing follicles isolated from ovaries stored at 4 degrees C for 18 h and at 20 degrees C for 6 h were cultured for 3 days. Follicles stored in either condition presented the same growth pattern in vitro as fresh follicles. We conclude that storage of pig ovaries at 4 degrees C for up to 18 h or at 20 degrees C for up to 6 h does not affect the morphology of growing follicles or their ability to grow in vitro.