Effect of Oil Overlay on Inhibition Potential of Roscovitine in Sheep Cumulus‐Oocyte Complexes

Inhibitors of cyclin‐dependent kinases, as roscovitine, have been used to prevent the spontaneous resumption of meiosis in vitro and to improve the oocyte developmental competence. In this study, the interference of oil overlay on the reversible arrest capacity of roscovitine in sheep oocytes as well as its effects on cumulus expansion was evaluated. For this, cumulus‐oocyte complexes (COCs) were cultured for 20 h in TCM 199 with 10% foetal bovine serum (Control) containing 75 μm roscovitine (Rosco). Subsequently, they were in vitro matured (IVM) for further 18 h in inhibitor‐free medium with LH and FSH. The culture was performed in Petri dishes under mineral oil (+) or in 96 well plates without oil overlay (?) at 38.5°C and 5% CO₂. At 20 and 38 h, the cumulus expansion and nuclear maturation were evaluated under stereomicroscope and by Hoechst 33342 staining, respectively. No group presented cumulus expansion at 20 h. After additional culture with gonadotrophins, a significant rate of COCs from both Control groups (+/?) exhibited total expansion while in both Rosco groups (+/?) the partial expansion prevailed. Among the oocytes treated with roscovitine, 65.2% were kept at GV in the absence of oil overlay while 40.6% of them reached MII under oil cover (p < 0.05). This meiotic arrest was reversible, and proper meiosis progression also occurred in the Control groups (+/?). So, the culture system without oil overlay improved the meiotic inhibition promoted by roscovitine without affecting the cumulus expansion rate or the subsequent meiosis progression.     

Pathogenesis of reproductive failure induced by Trypanosoma vivax in experimentally infected pregnant ewes

The present study was aimed at investigating the effect of experimental infection by Trypanosoma vivax in different stages of pregnancy, determining the pathogenesis of reproductive failure, and confirming transplacental transmission. We used 12 pregnant ewes distributed into four experimental groups: G1, was formed by three ewes infected with T. vivax in the first third of pregnancy (30 days); G2 comprised three infected ewes in the final third of pregnancy (100 days); G3 and G4 were composed of three non-infected ewes with the same gestational period, respectively. Each ewe of G1 and G2 was inoculated with 1.25 × 10⁵ tripomastigotes. Clinical examination, determination of parasitemia, serum biochemistry (albumin, total protein, glucose, cholesterol, and urea), packed cell volume (PCV), serum progesterone, and pathological examination were performed. Placenta, amniotic fluid, blood and tissues from the fetuses and stillbirths were submitted to PCR. Two ewes of G1 (Ewe 1 and 3) presented severe infection and died in the 34^th and 35^th days post-infection (dpi), respectively; but both fetuses were recovered during necropsy. In G2, Ewe 5 aborted two fetuses on the 130^th day (30 dpi) of pregnancy; and Ewe 6 aborted one fetus in the 140^th day (40 dpi) of gestation. Ewes 2 and 4 delivered two weak lambs that died five days after birth. Factors possibly involved with the reproductive failure included high parasitemia, fever, low PCV, body score, serum glucose, total protein, cholesterol, and progesterone. Hepatitis, pericarditis, and encephalitis were observed in the aborted fetuses. The presence of T. vivax DNA in the placenta, amniotic fluid, blood, and tissues from the fetuses confirms the transplacental transmission of the parasite. Histological lesion in the fetuses and placenta also suggest the involvement of the parasite in the etiopathogenesis of reproductive failure in ewes.     

The optical isomers of α-cyano-3-phenoxybenzyl 3-(1,2-dibromo-2,2-dichloroethyl)-2,2-dimethylcyclo-propanecarboxylate and their insecticidal activities

Bromination of the dichlorovinyl group of cypermethrin yielded a new compound which is a highly potent insecticide. This dibromo adduct has four asymmetric centres and therefore can exist as a mixture of 16 stereoisomers. To establish the influence of the absolute configuration at the chiral centres on the biological activities of these isomers, each of the isomers was isolated; their insecticidal activities against larvae of Heliothis virescens, and adult Calliphora erythrocephala and Blattella germanica were then determined and compared with those of (S)-α-cyano-3-phenoxybenzyl (1R)-cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropanecarboxylate (deltamethrin NRDC 161), of fenvalerate, and of the eight stereoisomers of cyper methrin.     

Transduction of Vero cells and bovine monocytes with a herpes simplex virus-1 based amplicon carrying the gene for the bovine herpesvirus-1 Circ protein

Herpes simplex virus-1 (HSV-1) based amplicon vectors are promising gene delivery vehicles because they have a large transgene capacity and can efficiently transduce many different cell types, including non-dividing cells, of various animal species. The Circ protein of bovine herpesvirus-1 (BHV-1) is a myristylated virion component of unknown function. Preliminary experiments with a circ gene deletion mutant indicated that Circ may influence the host's immune response by downregulating MHC-II expression in bovine monocytes. To get more insight into the function of Circ, amplicon vectors were constructed with various open reading frames (ORFs) under the control of the HSV-1 IE4/5 promoter: (i) the Circ ORF alone, (ii) a fusion ORF encoding an N-terminal Circ fused to the enhanced green fluorescent protein (eGFP), (iii) the eGFP ORF alone, and (iv) the Circ ORF in the inverted orientation. Upon helpervirus-free packaging into HSV-1 amplicon particles and transduction of Vero cells, both Circ alone and the Circ-eGFP fusion protein produced a punctate pattern within the cytoplasm, suggesting membrane association of the myristylated protein. In contrast, eGFP alone was evenly distributed over the cytoplasm of transduced cells. Upon infection of bovine buffy-coat cells, it was observed that cells of the monocyte lineage but not lymphocytes were transduced. Transgene expression reached a peak around 20h after transduction and lasted for at least 90h. Transduced monocytes underwent specific morphological changes, which may be attributed to Circ synthesis.     

Sperm Morphology in the Domestic Cat, and its Relation with Fertility: A Retrospective Study

Knowledge about normal ranges in semen quality and the association between sperm morphology and fertility in felids is limited. The aims of this retrospective study were to (1) define a normal spermiogram in cats; (2) evaluate possible effects of season, age and breed on sperm morphology; and (3) evaluate the relationship between sperm morphology and fertility. Semen samples collected by electroejaculation from 52 cats were evaluated for sperm morphology. The cats constituted two groups: a general population of cats (n = 48) and cats examined because of poor breeding records (n = 4). The general population was divided into household (n = 20), pedigree (n = 19) and colony cats (n = 9) and into three age classes, <12 months, 12-59 months and >or=60 months. The median percentage of normal spermatozoa in the general population was 44.0% (range 1.0-91.0%). Criteria were tentatively set for what was considered a normal spermiogram. The mean percentage of normal spermatozoa was higher during February to July than during August to January (p < 0.05). Pedigree cats had a lower mean percentage of normal spermatozoa than did household cats (p < 0.05). Age had no effect on the percentage of normal spermatozoa but was positively correlated with the percentage of proximal droplets. Of the cats with <40% normal spermatozoa (n = 19), all those with known breeding records (n = 11) had produced litters. The four cats examined because of poor breeding results had higher percentages of different sperm abnormalities than tentatively stipulated for the normal spermiogram. In two of these cats both sperm morphology and fertility changed over time.     

Erythema multiforme associated with zonisamide in a dog

This report describes a dog that developed erythema multiforme in temporal association with administration of the sulphonamide‐based anticonvulsant drug zonisamide. Similar adverse drug reactions have been associated with sulphonamide antimicrobial drugs. Caution should be exercised when prescribing this medication for dogs with known hypersensitivity to sulphonamides.     

The effectiveness of the new morantel sustained-release trilaminate bolus against gastrointestinal nematode infections in cattle in their first grazing period

The efficacy of a recently developed Morantel-Sustained-Release-Trilaminate-Bolus (Paratect Flex Bolus [PFB]-Pfizer Inc.) against gastrointestinal nematode infections in cattle was assessed by monitoring faecal egg counts (EpG), herbage larval counts, serum pepsinogen levels and liveweight gains in first season calves. In two field trials (1987 and 1988), a PFB-Bolus was administered to two different groups of animals (1987: 15 calves; 1988:13 calves) at turnout (29 May 1987; 26 May 1988), control groups were included. In 1988, 13 calves received for comparison an Oxfendazole-Release-Bolus (Systamex Intervall Bolus [OXF]-Coopers Inc.). All groups were grazed on adjacent but separately fenced pastures throughout the season, until housing (27 October 1987; 15 October 1988). When compared with controls, the PFB-groups showed significantly lower EpG values and consequently, lower herbage larval counts throughout the season in both trials. From day 30 after turnout, the PFB-group had significantly lower serum pepsinogen levels, which reflects the low degree of abomasal damage in these animals. When compared to controls, the PFB-treated animals showed significantly higher weight performances. The mean weight-gain benefit of PFB-treated animals was +12.5 kg (p less than 0.05) and +21.1 kg (p less than 0.005) in 1987 and 1988, resp. No difference occurred between PFB-treated and OXF-treated calves, the latter outperformed the control animals by +21.6 kg (p less than 0.005).