There is a clear, unmet need for effective, lightweight, shelf-stable and economical snakebite envenoming therapies that can be given rapidly after the time of a snake’s bite and as adjuncts to antivenom therapies in the hospital setting. The sPLA2 inhibitor, LY315920, and its orally bioavailable prodrug, LY333013, demonstrate surprising efficacy and have the characteristics of an antidote with potential for both field and hospital use. The efficacy of the active pharmaceutical ingredient (LY315920) and its prodrug (LY333013) to treat experimental, lethal envenoming by Micrurus fulvius (Eastern coral snake) venom was tested using a porcine model. Inhibitors were administered by either intravenous or oral routes at different time intervals after venom injection. In some experiments, antivenom was also administered alone or in conjunction with LY333013. 14 of 14 animals (100%) receiving either LY315920 (intravenous) and/or LY333013 (oral) survived to the 120 h endpoint despite, in some protocols, the presence of severe neurotoxic signs. The study drugs demonstrated the ability to treat, rescue, and re-rescue animals with advanced manifestations of envenoming. Low molecular mass sPLA2 inhibitors were highly effective in preventing lethality following experimental envenoming by M. fulvius. These findings suggest the plausibility of a new therapeutic approach to snakebite envenoming, in this example, for the treatment of a coral snake species for which there are limitations in the availability of effective antivenom.
Following RIVP, high florfenicol concentrations were achieved in DV blood and SYNF, whereas the CV blood concentration remained low. In cattle, RIVP of florfenicol may be useful in the treatment of infectious processes involving the distal portion of limbs.
Brain ribonuclease (BRB) is a member of the ribonuclease A superfamily that is constitutively expressed in a range of tissues, and is the functional homolog of human ribonuclease 1. This study was designed to characterize BRB gene expression in granulosa cells (GC) during development of bovine dominant ovarian follicles, and to determine the hormonal regulation of BRB in GC. Estrous cycles of Holstein cows (n = 18) were synchronized and cows were ovariectomized on either day 3 to 4 or day 5 to 6 post-ovulation during dominant follicle growth and selection. Ovaries were collected, follicular fluid (FFL) was aspirated, and GC were collected for RNA isolation and quantitative PCR. Follicles were categorized as small (1 to 5 mm; pooled per ovary), medium (5 to 8 mm; individually collected) or large (8.1 to 17 mm; individually collected) based on surface diameter. Estradiol (E2) and progesterone (P4) levels were measured by RIA in FFL. Abundance of BRB mRNA in GC was 8.6- to 11.8-fold greater (P < 0.05) in small (n = 31), medium (n = 66) and large (n = 33) subordinate E2-inactive (FFL E2 < P4) follicles than in large (n = 16) dominant E2-active (FFL E2 > P4) follicles. In the largest 4 follicles, GC BRB mRNA abundance was negatively correlated (P < 0.01) with FFL E2 (r = −0.65) and E2/P4 ratio (r = −0.46). In Exp. 2, GC from large (8 to 22 mm diameter) and small (1 to 5 mm diameter) follicles were treated with IGF1 (0 or 30 ng/mL), and/or tumor necrosis factor α (TNFα) (0 or 30 ng/mL); IGF1 increased (P < 0.05) BRB mRNA abundance and TNFα decreased (P < 0.001) the IGF1-induced BRB mRNA abundance in large-follicle GC. In Exp. 3 to 6, E2, FSH, fibroblast growth factor 9 (FGF9), cortisol, wingless 3A (WNT3A), or Sonic hedgehog (SHH) did not affect (P > 0.10) abundance of BRB mRNA in GC; thyroxine and LH increased (P < 0.05) whereas prostaglandin E2 (PGE2) decreased (P < 0.05) BRB mRNA abundance in small-follicle GC. Treatment of small-follicle GC with recombinant human RNase1 increased (P < 0.05) GC numbers and estradiol production. In conclusion, BRB is a hormonally and developmentally regulated gene in bovine GC and may regulate estradiol production during follicular growth in cattle.
Humane euthanasia of cattle represents a challenge to the beef and dairy industries. Penetrating captive bolt, while traditionally considered to be only a stunning method, can be an effective single-step euthanasia method if both the cerebral cortex and brainstem are disrupted. This report describes a preliminary study investigating the likelihood of brainstem disruption for two captive-bolt shot locations. Heads were collected from 15 cattle that died or were euthanised for reason unrelated to the study and were then randomly assigned to one of two shot placement groups. Heads in the first group (n = 7) were shot at the intersection of two lines drawn from the medial canthus to the opposite horn or top of the opposite ear. Heads in the second group (n = 8) were shot at the intersection of two lines drawn for the lateral canthus to the opposite horn or top of the opposite ear. The guns were held perpendicular (as assessed visually) to the plane of the forehead. Shot placement was then assessed using computed tomography and disruption of the brainstem was determined. In the first group, the captive bolt failed to disrupt the brainstem in any of the heads. In the second group, the bolt disrupted the brainstem in 6 of 8 heads. The results suggest that selecting a higher shot location leads more readily to disruption of the brainstem which reduces the risk of regaining sensibility and should therefore improve animal welfare when cattle are euthanised with a penetrating captive bolt.
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