Effect of Alpha-Tocopherol and Ascorbic Acid on Bovine Oocyte in Vitro Maturation

In vitro culture results in higher oxygen concentrations than in vivo environments, leading to an increased level of reactive oxygen species (ROS) that cause lipid peroxidation of cellular membranes. Alpha-tocopherol (active form of vitamin E) is an antioxidant that protects mammalian cells against lipid peroxidation, which is regenerated by ascorbic acid. The aim of this study was to determine the effect of the addition of alpha-tocopherol and/or ascorbic acid to the maturation medium on bovine oocyte in vitro maturation (IVM) and subsequently on in vitro fertilization (IVF) and embryo development. Cumulus-oocyte complexes (COCs) were matured in Medium 199 (control), and with the addition of alpha-tocopherol and/or ascorbic acid. The concentration of alpha-tocopherol in COCs was determined by high-performance liquid chromatography (HPLC). IVF and in vitro culture (IVC) were carried out in modified synthetic oviductal fluid (mSOF). The quantity of alpha-tocopherol naturally present in COCs diminished by half during IVM (p < 0.05), although in the presence of ascorbic acid it remained constant. A greater amount of alpha-tocopherol was detected in COCs matured in medium supplemented with this antioxidant (p < 0.05), but the addition of alpha-tocopherol plus ascorbic acid maintained higher levels of alpha-tocopherol (p < 0.05). Significant differences were not observed in the percentages of nuclear maturation and fertilization among different treatments. The presence of alpha-tocopherol or ascorbic acid in the maturation medium failed to modify the percentage of blastocysts obtained, unlike the addition of both antioxidants when a significant decrease was observed (p < 0.05). Absorbic acid maintained the antioxidant capacity of the alpha-tocopherol incorporated to COC membranes during IVM. The active form of vitamin E during maturation impaired the acquisition of oocyte developmental competence.     

Short communication: Progressive motility of frozen–thawed canine semen is highest five minutes after thawing

Progressive motility is usually estimated by visual inspection using a light contrast microscope at X 100 immediately after semen collection or immediately after thawing frozen semen. Standard operating procedures have never been established for this test. The objective of this experiment was to examine time‐dependent changes of motility after thawing cryopreserved canine semen. Semen of 35 dogs was collected, and volume, concentration, progressive motility, morphology, membrane integrity and HOS test were evaluated. For cryopreservation, CaniPRO^® Freeze A&B was used. Semen was thawed and diluted using CaniPRO^® culture medium. After thawing, semen was evaluated as before. In addition, every sample was evaluated for progressively motile sperm cells 0, 5, 20 and 60 min after thawing. Progressive semen motility was significantly highest five minutes after thawing.     

RESEARCH PAPER: Comparison between two methods for cardiac output measurement in propofol‐anesthetized dogs: thermodilution and Doppler

ObjectiveTo compare cardiac output (CO) measured by Doppler echocardiography and thermodilution techniques in spontaneously breathing dogs during continuous infusion of propofol. To do so, CO was obtained using the thermodilution method (CO_TD) and Doppler evaluation of pulmonary flow (CO_DP) and aortic flow (CO_DA).Study designProspective cohort study.AnimalsEight adult dogs weighing 8.3 ± 2.0 kg.MethodsPropofol was used for induction (7.5 ± 1.9 mg kg^?1 IV) followed by a continuous rate infusion at 0.7 mg kg^?1 minute^?1. The animals were positioned in left lateral recumbency on an echocardiography table that allowed for positioning of the transducer at the 3rd and 5th intercostal spaces of the left hemithorax for Doppler evaluation of pulmonary and aortic valves, respectively. CO_DP and CO_DA were calculated from pulmonary and aortic velocity spectra, respectively. A pulmonary artery catheter was inserted via the jugular vein and positioned inside the lumen of the pulmonary artery in order to evaluate CO_TD. The first measurement of CO_TD, CO_DP and CO_DA was performed 30 minutes after beginning continuous infusion (T0) and then at 15‐minute intervals (T15, T30, T45 and T60). Numeric data were submitted to two‐way anova for repeated measurements, Pearson’s correlation coefficient and Bland &; Altman analysis. Data are presented as mean ± SD.ResultsAt T0, CO_TD was lower than CO_DA. CO_DA was higher than CO_TD and CO_DP at T30, T45 and T60. The difference between the CO_TD and CO_DP, when all data were included, was ?0.04 ± 0.22 L minute^?1 and Pearson’s correlation coefficient (r) was 0.86. The difference between the CO_TD and CO_DA was ?0.87 ± 0.54 L minute^?1 and r = 0.69. For CO_TD and CO_DP, the difference was ?0.82 ± 0.59 L minute^?1 and r = 0.61.ConclusionDoppler evaluation of pulmonary flow was a clinically acceptable method for assessing the CO in propofol‐anesthetized dogs.     

Pharmacokinetics of ceftiofur crystalline-free acid sterile suspension in the equine

Collard, W. T., Cox, S. R., Lesman, S. P., Grover, G. S., Boucher, J. F., Hallberg, J. W., Robinson, J. A., Brown, S. A. Pharmacokinetics of ceftiofur crystalline‐free acid sterile suspension in the equine. J. vet. Pharmacol. Therap. 34 , 476–481. Absolute bioavailability and dose proportionality studies were performed with ceftiofur in horses. In the absolute bioavailability study, thirty animals received either an intravenous dose of ceftiofur sodium at 1.0 mg/kg or an intramuscular (i.m.) dose of ceftiofur crystalline‐free acid (CCFA) at 6.6 mg/kg. In the dose proportionality study, 48 animals received daily i.m. ceftiofur sodium injections at 1.0 mg/kg for ten doses or two doses of CCFA separated by 96 h, with CCFA doses of 3.3, 6.6, or 13.2 mg/kg. Noncompartmental and mixed‐effect modeling procedures were used to assess pharmacokinetics (PK). CCFA was well absorbed with a bioavailability of 100%. AUC_0–∞ and C_max increased in a dose‐related manner following administration of the two doses of CCFA at 3.3, 6.6, and 13.2 mg/kg. The least‐squares mean terminal half‐life (t_½) following the tenth daily i.m. injection of ceftiofur sodium at 2.2 mg/kg was 40.8 h, but the least‐squares mean t_½ following the second i.m. injection of CCFA at 6.6 mg/kg was 100 h. The time that plasma ceftiofur equivalent concentrations remain above a threshold concentration of 0.2 μg/mL has been associated with efficacy, and following administration of two 6.6 mg/kg doses of CCFA, the mean time above 0.2 μg/mL was 262 h. Simulations with the nonlinear mixed‐effect PK model predicted that more than 97.5% of horses will have plasma ceftiofur equivalent concentrations >0.2 μg/mL for 96 h after the second 6.6 mg/kg dose of CCFA.     

Pulmonary pharmacokinetics of tulathromycin in swine. Part 2: Intra‐airways compartments

The objective of this study was to assess the pharmacokinetics of tulathromycin in pulmonary and bronchial epithelial lining fluid (PELF and BELF) from pigs. Clinically healthy pigs were allocated to two groups of 36 animals each. All animals were treated with tulathromycin (2.5 mg/kg/i.m). Animals in group 2 were also challenged intratracheally with lipopolysaccharide from Escherichia coli 3 h prior to tulathromycin administration. Both PELF and BELF samples were harvested using bronchoalveolar lavage fluid and bronchial micro‐sampling probes, respectively. Samples were taken for 17 days post‐tulathromycin administration. No statistical differences in the concentration of tulathromycin were observed in PELF between groups. The concentration vs. time profile in BELF was evaluated only in Group 1. Tulathromycin distributed rapidly and extensively into the airway compartments. The time to maximal (T_max) concentration was 6 h postdrug administration in PELF but 72 h post‐tulathromycin administration for BELF. In group 2, the T_max was seen at 24 h post‐tulathromycin administration. The area under the concentration time curve (h*ng/mL) was 522 000, 348 000 and 1 290 000 for PELF_Group‐1, PELF_Group‐2, and BELF_Group‐1, respectively. Tulathromycin not only distributed rapidly into intra‐airway compartments at relatively high concentrations but also resided in the airway lining fluid for a long time (>4 days).     

Hemorrhagic stomatitis in a natural hybrid of Vipera ammodytes × Vipera berus due to inappropriate substrate in terrarium

A natural hybrid of Vipera ammodytes × Vipera berus was presented having low body weight, seizures and generalized swelling of the cephalic region. Based on the history of the case and clinical examination, hemorrhagic stomatitis of traumatic origin was diagnosed. The snake was kept in a terrarium with wood chips as a substrate, and the material had induced trauma in the oral mucosa which was further complicated with Salmonella Arizonae and Morganella morganii co-infection, abscessation and osteomyelitis. To the best of the authors’ knowledge, this is the first reported case of bacterial infection in European snake hybrids and one of a few case reports in European snakes. Although wood chips are an inexpensive substrate, based on our findings, they should be avoided when keeping and breeding European vipers.     

The Effect of Sperm Concentration and Storage Vessel on Quercetin‐Supplemented Rabbit Semen During Chilled Storage

Extending the shelf life of chilled rabbit spermatozoa is vital for the expansion of the farmed rabbit industry. This study evaluated the relationship between sperm concentration and packaging on in vitro quality of chilled rabbit semen over 96 h. Semen was collected from adult bucks (n = 4) and pooled at 37°C following evaluation. Pooled ejaculates were diluted with a Tris‐based extender supplemented with 100 μm quercetin to a concentration of 15, 30 or 60 × 10⁶ spermatozoa/ml, packaged into plastic tubes or 0.5‐ml straws and stored at 15°C. Sperm quality was assessed by computer‐assisted sperm Analysis [total motility (tMOT)] and flow cytometry [viability, acrosome integrity, H₂O₂ production, plasma membrane disorder, apoptosis and DNA fragmentation index (DFI)] at 0, 48, 72 and 96 h. From 48 h, concentrations of 30 and 60 × 10⁶ spermatozoa/ml reported the highest tMOT, irrespective of storage vessel (p < 0.05). Storage in straws reduced oxidative stress and improved plasma membrane stability. The %DFI, mean DFI and SD‐DFI were increased in spermatozoa stored in tubes compared with straws (p < 0.05). Although the use of low sperm concentrations in artificial insemination doses would facilitate greater dispersion of genetically superior rabbit bucks, dilution to 15 × 10⁶ spermatozoa/ml had a detrimental impact on motility. As such, chilled storage at 30 × 10⁶ spermatozoa/ml may provide a suitable balance between motility and H₂O₂ production to best maintain overall sperm function and should be evaluated in a large‐scale AI trial.     

Increasing urea-N efficiency in transplanted lowland rice by urea solution band placement

Alternative N fertiliser management strategies are needed to increase N-use efficiency in wetland rice (Oryza sativa L.). In the wet season of 1993–1994, field experiments were conducted to evaluate the band placement of urea solution in comparison with broadcast prilled urea, neem-coated urea, or point-placement of urea supergranules. Both grain yield and N-use efficiency were higher with band placement of urea solution (50 or 100 kg N ha^-1) compared to a conventional split application of prilled urea at 100 kg N ha^-1. The total ¹⁵N recovery was 58.7 and 51.7% with band placement of urea solution at 50 and 100 kg N ha^-1, respectively, compared with 47.8% for neem-coated urea and 28.5% for a conventional split application of prilled urea. Current address: Training Division, KVK, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India Pin 641 003     

Asymmetric scattering of polarized electrons by organized organic films of chiral molecules

Electron transmission experiments demonstrate a large asymmetry in the scattering probability of polarized electrons by thin organized films of chiral molecules. This large asymmetry results from the interaction of the electron's wavefunction with many scatterers (molecules) in the organized monolayer structure and represents a manifestation of quantum interference on the scale of supramolecular lengths.     

Serum and mucosal antibody responses and protection in pigs vaccinated against Mycoplasma hyopneumoniae with vaccines containing a denatured membrane antigen pool and adjuvant

Objective To investigate the protective efficacy of a pool of denatured membrane protein antigens of Mycoplasma hyopneumoniae (J strain) in the molecular size range 70 to 85 kDa (F3 antigen) in combination with adjuvants for pigs challenged with M hyopneumoniae .
Design A vaccine efficacy experiment with assessment of serum and respiratory tract antibody responses.
Procedure F3 antigens were emulsified with five different adjuvants. To groups of three pigs per vaccine, four vaccines were given by intramuscular injection, and two vaccines, including one of those given intramuscularly, were given by intraperitoneal injection.
Results Compared to six unvaccinated pigs, animals vaccinated with F3 antigen displayed significantly reduced pneumonia (54% reduction in mean lung score) following experimental challenge. Analysis of post-vaccination, pre-challenge IgG and IgA ELISA antibody absorbances in serum and respiratory tract washings revealed no correlation with lung score. Six weeks after challenge, pigs previously vaccinated intramuscularly mostly demonstrated greater IgG and IgA responses in respiratory tract washings, and greater IgG serum antibody responses, than those vaccinated by intraperitoneal injection.
Conclusion Pigs vaccinated with M hyopneumoniae antigens in the molecular size range of 70 to 85 kDa showed a significant reduction in lung lesions compared with unvaccinated control animals after experimental challenge. IgG and IgA antibody concentrations in serum and respiratory tract washings after vaccination do not provide a useful prognostic indicator of protection from enzootic pneumonia.