Conversion of Cortisone to Cortisol and Prostaglandin F2α Production by the Reproductive Tract of Cows at the Late Luteal Stage In Vivo

Previous in vitro studies demonstrated that bovine endometrium has the capacity to convert inactive cortisone to biologically active cortisol (Cr) and that Cr inhibits cytokine‐stimulated prostaglandin F_2α (PGF) production. This study was carried out to test the hypothesis that bovine reproductive tract has the capacity to convert cortisone to Cr in vivo and to evaluate the effects of intravaginal application of exogenous cortisone on uterine PGF secretion during the late luteal stage. The temporal relationships between PGF and Cr levels in uterine plasma were also determined. Catheters were inserted into jugular vein (JV), uterine vein (UV), vena cava caudalis (VCC) and aorta abdominalis (AA) of six cows on Day 15 of the oestrous cycle (ovulation = Day 0) for frequent blood collection. On Day 16, the cows were divided randomly into two groups and infused intravaginally with vaseline gel (10 ml; control; n = 3) or cortisone dissolved in vaseline gel (100 mg; n = 3). Blood samples were collected at ?2, ?1, ?0.5, 0, 0.5, 1, 1.5, 2, 3, 4, 5 and 6 h after treatments (0 h). Intravaginal application of cortisone increased plasma concentrations of Cr between 0.5 and 1.5 h in UV, at 0.5 h in VCC, at 1 h in JV and at 1.5 h in AA. The plasma concentrations of PGF in UV and of PGF metabolite in JV were greater at 0.5 and 1 h in the cortisone‐treated animals than in control animals. The levels of PGF in UV blood plasma decreased after Cr reached its highest levels. The overall findings suggest that the female reproductive tract has the capacity to convert cortisone to Cr in vivo. Based on the temporal changes of PGF and Cr levels in the uterine plasma, a biphasic response in PGF secretion was found to be associated to the Cr increase induced by the cortisone treatment at the late luteal stage in non‐pregnant cows.     

Elevated extrahepatic expression and secretion of mammary-associated serum amyloid A 3 (M-SAA3) into colostrum.

Mammary-associated serum amyloid A 3 (M-SAA3) was secreted at highly elevated levels in bovine, equine and ovine colostrum and found at lower levels in milk 4 days postparturition. N-terminal sequencing of the mature M-SAA3 protein from all the three species revealed a conserved four amino acid motif (TFLK) within the first eight residues. This motif has not been reported to be present in any of the hepatically-produced acute phase SAA (A-SAA) isoforms. Cloning of the bovine M-Saa3 cDNA from mammary gland epithelial cells revealed an open reading frame that encoded a precursor protein of 131 amino acids which included an 18 amino acid signal peptide. The predicted 113 residue mature M-SAA3 protein had a theoretical molecular mass of 12,826Da that corresponded with the observed 12.8kDa molecular mass obtained for M-SAA3 in immunoblot analysis. The high abundance of this extrahepatically produced SAA3 isoform in the colostrum of healthy animals suggests that M-SAA3 may play an important functional role associated with newborn adaptation to extrauterine life and possibly mammary tissue remodeling.     

Exploring Nontraditional Pathways Into Hunting in New York State: Implications for Recruitment and Retention

Anecdotal evidence suggests that adults lacking previous hunting experience and family support for hunting comprise a growing proportion of new hunters. Empirical evidence of such a trend is lacking. Furthermore, hunting motivations and constraints for these “nontraditional path hunters” (NTPHs) have not been well documented. We articulate a strategy for identifying potential NTPHs in New York, describe socialization mechanisms initiating NTPHs into hunting, and explore motivations and constraints of these hunters. Data were collected using a Web-based survey of 3,605 NTPHs identified among 2014 Sportsman Education course graduates in New York. We found that many NTPHs were initiated by friends and co-workers, and their motivations and constraints were similar to traditional hunters. These findings suggest that NTPHs are not a panacea to the trend of declining numbers of hunters in New York.     

Haemolytic anaemia in cattle in NSW associated with Theileria infections

Several outbreaks of anaemia, jaundice, abortion and mortality in cattle in New South Wales were attributed to the intracellular parasite, Theileria buffeli . Disease occurred predominantly in periparturient animals that had been moved from inland to coastal areas. Diagnosis was made via exclusion of other causes of haemolytic anaemia and observation of the parasite in blood smears. Treatments included both registered and non-registered products. There is a possibility of a new strain of Theileria sp. in Australia and the possible vectors encountered in NSW are discussed.     

Fusion of Boar Sperm with Nanoliposomes Prepared from Synthetic Phospholipids

Liposomes are artificial membrane vesicles that can be used to test and model the functions and interactions of various biological membranes, or as a carrier system to deliver biologically active substances into the cells, or to incorporate lipids into the plasma membrane of target cells to modify membrane structure–function relationships. Sperm plasma membrane undergoes lipid modification during maturation in epididymis and during capacitation in the female reproductive tract to facilitate fertilization. Natural variation in the amounts and composition of lipids in the sperm plasma membrane may also contribute to the species‐specific sperm sensitivities to handling and storage conditions. Boar sperm are notoriously susceptible to membrane damage and are resistant to compositional alteration by artificial liposomes. This study used flow cytometry to demonstrate stable incorporation of nanoliposomes prepared from a complex mixture of various phospholipids (phosphatidylcholine : phosphatidylethanolamine : sphingomyelin : phosphatidylserine : phosphatidylinositol) with high fusion efficiency. Over 90% of sperm rapidly took up fluorescently labelled liposomes and retained the lipids for at least 60 min, in a significant time‐ and concentration‐dependent manner. This unique fusion efficacy could be used to alter sperm plasma membrane composition and hence membrane‐based functional responses.