Effects of complement component 3 derivatives on pig oocyte maturation, fertilization and early embryo development in vitro

Complement component 3 (C3) has well-established roles within immune system, but its roles outside of immune system are less characterized. The extensive presence of C3 throughout the female reproductive tract, and its temporal, and gamete-specific regulation of expression suggest a potential role for C3 in reproduction. In the present investigation, the effects of C3, C3b and iC3b on porcine oocyte maturation, fertilization and embryonic development were examined. We identified the ability of iC3b to positively influence oocyte maturation. No effects on fertilization efficiency, penetration rates, polyspermy and blastocyst formation were observed. However, C3, C3b and iC3b presence in embryo culture medium resulted in fewer total cells in test blastocysts compared to control blastocysts. The results of this study indicate a potential function for iC3b in oocyte maturation. Furthermore, it was demonstrated that the presence of either C3, C3b or iC3b has a negative influence on early embryonic development in the porcine species.     

Last occurrence and survival during winter of the arbovirus vector Culicoides brevitarsis at the southern limits of its distribution

SUMMARY: Linear regression analysis was used to describe the decline in numbers of Culicoides brevitarsis Kieffer into winter with monthly maximum, average and minimum temperatures at the southern limits to its distribution in New South Wales. From this, low temperature thresholds were derived when C brevitarsis would be absent from the field. The low minimum threshold ± 2 SE (95% Confidence Interval) of 8.1 ± 0.3°C was used with historical temperature data to estimate the last month that the species should occur (March to June) and the mean number of months (2 to 6.5) below the threshold at 17 selected sites. Probability for survival during winter at these sites was estimated from years when the number of consecutive months below the threshold was ≤ 2 months. This varied from zero to 51% depending on the location of the site. Last occurrence was 0.7 months later on average and absolute probabilities for survival ranged from zero to 100% when the temperatures were increased by an arbitrary 2°C.     

Anthelmintic resistance in Australian sheep nematode populations

SUMMARY The resistance status of gastro–intestinal nematodes to anthelmintics was evaluated on 881 sheep farms throughout Australia during 1991–92. Resistance was shown to be widespread. Overall, 85% of farms had sheep infected with nematodes resistant to benzimidazole, 65% to levamisole and 34% to combination (benzimidazole + levamisole) products. Resistance to ivermectin was not detcted. On only 9% of farms did all anthelmintic groups reduce egg counts by greater than or equal to 95%. The culture of faeces from untreated sheep showed Telodorsagia circumcincta, Trichostrongylus spp, Chabertia ovina and Haemonchus contortus to be the principal species. The nature and prevalence of resistance was not significantly correlated with stocking rate. However, resistance to combination products was almost twice as prevalent on farms in areas with an average annual rainfall of greater than 500 mm.     

A Rare Case of Polyorchidism in a Cat with Four Intra‐abdominal Testes

Polyorchidism is a rare congenital anomaly defined as the presence of more than two histologically proven testes. We report a case of a 9‐month‐old European cat with four intra‐abdominal testes. The diagnosis was performed by means of ultrasonography, intra‐operative examination and histological confirmation. The case reported here presents an extremely rare anomaly, as no previous studies in veterinary medicine have reported the presence of four testes. This case suggests that supernumerary testes should be included as differential diagnoses for intra‐abdominal masses.     

Determination of enzymatic activities using a miniaturized system as a rapid method to assess soil quality

Soil quality determination requires the analysis of a number of soil attributes using different approaches. In recent years, one of the most promising approaches has been the determination of enzymatic activities. Generally, only a few enzymes have been analysed and related to other soil properties such as total carbon, nitrogen content or microbial biomass carbon. The aim of this work was to investigate the possible use of the API ZYM strip, a semi‐quantitative miniaturized system that determines 19 enzymatic activities, to study soil quality. To this end, we tested the system in different soil types, including albic Arenosols, mollic Leptosols, rendzic Leptosols, haplic Leptosols and calcaric Regosols. Fresh samples were sieved through a 2‐mm sieve in the field and soil extracts were prepared by mixing 2–20 g (depending on the soil horizon characteristics) from each sample with 2–20 ml of sterile water. Next, 65‐µl aliquots of the supernatant extract were placed into each API ZYM microtube and were incubated at 37°C for 16 hours. Our results show important qualitative and quantitative differences among the different soil types studied, with soil characteristics and biological properties correlating with biochemical information. The results provide useful information not only to determine soil quality, but also to assess changes in the soil environment. As a whole, our results suggest that the use of the API ZYM system could prove most useful in soil environmental studies. Finally, some suggestions are presented, including modifications to the system that could improve its application in this field.     

Effect of Episodic and Regular Sewage Discharges on the Water Chemistry and Macroinvertebrate Fauna of a Mediterranean Stream

Physical, chemical and biological parameters were used to investigate the effects of regular and episodic sewage inputs,either domestic or industrial, on the water quality of a smallMediterranean stream (River Magro, eastern Spain). Although results from chemical analyses were useful for monitoring waterquality in areas where sewage discharge was regular, episodic andlocalised discharges from industries or farms were not detected by chemical analyses because sampling was performed seasonally. An adequately small number of macroinvertebrate taxa were foundto indicate water quality changes within R. Magro, and the presence/absence and relative abundance of these taxa can be usedas a simple, rapid, low cost method for detecting changes in water quality. Macroinvertebrates are highly sensitive to episodic sewage discharges, which are difficult to detect by classical physical and chemical monitoring.