A laser-based method for measuring thermal nociception of cattle

We describe a method for measuring nociception in cattle using a CO(2) laser aimed at the caudal aspect of the metatarsi. In Experiment 1, infrared thermography showed that calves responded by lifting their legs when skin temperatures reached 45-55 degrees C. In Experiment 2a, the validity of the method was tested by comparing the response latencies of 14 calves to two power settings (2.25 W vs. 4.5 W) with each setting being applied six times. We found that both leg-lift latencies and tail-flick latencies were lower at the higher power setting, and the calves were more likely to respond by kicking than by simply moving the leg. The standard deviations between and within calves were smaller at the higher power setting, and the large within-calf variation means that at least three tests were required to obtain reliable measures that could differentiate between calves. In Experiment 2b, application of the laser at a range of power settings (2.0, 3.0, 4.0, 4.5, 5.0 and 5.5 W) on 16 calves showed that response latencies decreased as power increased up to 4.5 W, after which no further change occurred. In Experiment 3, the repeatability of the method was evaluated on nine measures with the high power setting (4.5 W). The coefficient of variation associated with repetition of the measures was 36%. In general, we found little change in response latencies with repeated use of the laser, except that responses on the second test tended to be shorter. Experiment 4 showed that ambient temperatures between 16 degrees C and 27 degrees C did not affect response latencies, but these were longer at temperatures of 7 degrees C. We suggest that the method is a useful way of measuring cattle's sensitivity to nociception as the animals need not be restrained and the distance to the animal need not be closely controlled. However, to obtain accurate, valid and reliable measures it is necessary to use a high power setting (4.5 W) and take at least three consecutive measures of the response latency.     

QTL mapping of foliar glycoalkaloid aglycones in Solanum tuberosum×S. berthaultii potato progenies: quantitative variation and plant secondary metabolism

 Glycoalkaloids are quantitatively inherited in Solanum, and in high concentrations they can be toxic to humans. The increased use of wild potato germplasm to improve the pest resistance, yield, and quality characteristics of cultivated potato may elevate or introduce new, more toxic glycoalkaloids into the cultivated gene pool. Therefore, it is important to increase our understanding of their inheritance, accumulation, and biosynthesis. Glycoalkaloids have two basic constituents – a glycosidic grouping and a steroid alkaloid skeleton. Steroid alkaloids are classified as solanidanes and spirosolanes, of which solanidine and solasodine are, respectively, representatives. RFLP-mapped, diploid, reciprocal backcross potato progenies involving the parents S. tuberosum and S. berthaultii, which produce solanidine and solasodine, respectively, were analyzed for segregation of the glycoalkaloids solanine, chaconine, solasodine and solamargine to identify quantitative trait loci (QTLs) for the production of the aglycones solanidine and solasodine. The F₁ clone M200-30 exhibited low to nondetectable levels of solasodine and solanidine, suggesting that expression was controlled by recessive genes. In a backcross to berthaultii (BCB) and backcross to tuberosum (BCT), several QTLs for the accumulation of solasodine and solanidine were identified. Three QTLs explaining approximately 20% of the variation in solasodine were identified in BCB on chromosomes 4, 6, and 12. Similarly, three QTLs were identified in BCT on chromosomes 4, 8 and 11, but these accounted for only 10% of the variation observed in solasodine accumulation. Two QTLs for solanidine were identified in BCT on chromosomes 1 and 4. The QTL located on chromosome 1 was highly significant, accounting for 17% and 22% of the variation in solanidine accumulation in 1994 and 1995, respectively. This same QTL was also detected in BCB. The QTLs detected in this study probably represent structural and/or regulatory genes controlling the accumulation of solasodine and solanidine. Results are discussed in the context of steroid alkaloid accumulation and biosynthesis. Received: 27 August 1997 / Accepted: 16 March 1998     

Spectrometric studies on stability of tenuazonic acid (TeA) solution in organic solvents

The stability of tenuazonic acid solution at different temperatures and storage times was studied using methanol, methanol-water (8:2 v/v), benzene and benzene-acetonitrile (98:2 v/v) as solvents. Solutions were analysed by a spectrometric method TeA U.V.-spectrum was recorded. Results indicated that the optimum temperature for long-time storage period of tenuazonic acid solution in any solvent assayed is -20°C. Benzene and benzene-acetonitrile (98:2 v/v) could be advised to make tenuazonic acid solution which will be stored less than 2 months at 4°C. Methanol and methanolwater (8:2 v/v) are not recommended because a low stability of TeA solution in this solvents.     

Comparative biological evaluation of two ethylene linked mixed binuclear ferrocene/ruthenium organometallic species

Two ethylene linked binuclear mixed ferrocene/ruthenium complexes were biologically investigated in comparison to structurally related mononuclear ferrocene or ruthenium species with styryl substituents or ligands. Results indicated that the electron distribution (but not the redox potential), cellular uptake and (to some minor extent) anti-estrogenic effects were the key contributors to antiproliferative effects observed in tumor cell lines.     

Rapid synthesis of an array of trisubstituted urea-based soluble epoxide hydrolase inhibitors facilitated by a novel solid-phase method

A 270-membered library of trisubstituted ureas was synthesized and evaluated for inhibition of soluble epoxide hydrolase. Library design and reagent selection was guided by the use of a pharmacophore model and synthesis of the array was enabled with a general solid-phase method. This array approach facilitated multi-dimensional SAR around this series and identified functionality responsible for binding affinity, as well as opportunities for modulating the overall in vitro profiles of this class of soluble epoxide hydrolase inhibitors.     

Effect of exogenous circulating anti-bPL antibodies on bovine placental lactogen measurements in foetal samples

Background  

The involvement of placental lactogen (PL) in the regulation of foetal growth has been investigated in different species by in vivo immunomodulation techniques. However, when circulating antibodies are present together with the hormone, the procedure for hormonal measurement becomes considerably complex. The aim of this study was the immunoneutralization of bovine placental lactogen (bPL) concentrations in bovine foetal circulation by direct infusion of rabbit anti-bPL purified immunoglobulins (IgG) via a foetal catheter (in vivo study). The ability of a RIA based on guinea pig anti-bPL antiserum, for the measurement of bPL concentrations in samples containing exogenous rabbit anti-bPL immunoglobulins, was also analyzed in in vitro and in vivo conditions.