Comparative study on the aflatoxin B1 degradation ability of rumen fluid from Holstein steers and Korean native goats

The aflatoxin B1 degrading abilities of two different ruminants were compared in this study. One set of experiments evaluated the aflatoxin B1 degradation ability of different rumen fluid donors (steers vs. goats) as well as the rumen fluid filtration method (cheese cloth filtered vs. 0.45 µm Millipore) in a 2 × 2 factorial arrangement. Additional studies examined aflatoxin B1 degradation by collecting rumen fluid at different times (0, 3, 6, 9 and 12 h) after feeding. Cannulated Holstein steers (740 ± 10 kg bw) and Korean native goats (26 ± 3 kg bw) were fed a 60% timothy and 40% commercial diet with free access to water. Rumen fluid from Korean native goats demonstrated higher (p < 0.01) aflatoxin B1 degradability than Holstein steers. However, filtration method had no significant influence on degradability. In addition, aflatoxin degradation did not depend upon rumen fluid collection time after feeding, as no significant differences were observed. Finally, a comparison of two types of diet high in roughage found aflatoxin degradability in goats was higher with timothy hay opposed to rice straw, although individual variation existed. Thus, our findings showed the aflatoxin degradability is comparatively higher in goats compared to steers.     

Determinants of drought effects on crown condition and their relationship with depletion of carbon reserves in a Mediterranean holm oak forest

Severe droughts may increase physiological stress on long-lived woody vegetation, occasionally leading to rapid defoliation and progressive increase in mortality of overstorey trees. Over the last few years, episodes of drought-induced tree dieback have been documented in a variety of woodlands and forests around the world. However, the factors determining tree survival and subsequent recovery are still poorly understood, especially in resprouter species. We have studied the effects of a single drought episode on crown condition in a holm oak (Quercus ilex L.) forest located in NE Spain 7 years after the drought event. Generalized linear models were used to study the environmental correlates of forest crown condition 7 years after the drought event. Additionally, we evaluated the association between crown condition and the carbon and nutrient reserves stored in lignotubers 7 years after the drought. Our study reveals the multifactor nature of a drought-driven forest dieback in which soil depth and the characteristics of individual trees, particularly their number of stems, determined a complex spatial pattern of tree-level responses. This dieback was associated with a depletion of the carbon reserves in lignotubers 7 years after the episode, representing a reduction of up to 60% in highly drought-damaged trees. Interestingly, in the absence of new acute droughts, successive surveys in 2007-11 showed a direct association between carbon reserves depletion and further deterioration of crown condition. More frequent droughts, as predicted by climate change projections, may lead to a progressive depletion of carbon reserves and to a loss of resilience in Mediterranean resprouter species.     

Intravenous Tramadol Injection has no Antinociceptive Effect in Horses Undergoing Electrical and Thermal Stimuli

Tramadol combines an μ opiate and nonopiate analgesic mechanism and might be a useful opioid in horses. This study evaluated the effect of IV tramadol on spontaneous locomotor activity (SLA), head height, and hoof withdrawal reflex (HWR) after thermal or electrical nociceptive stimuli in horses. Doses of 2 and 3 mg/kg tramadol did not affect HWR after electrical and thermal nociception, respectively. Head height and SLA were not modified by 2, 3, or 5 mg/kg tramadol. All horses treated with 5 mg/kg tramadol developed trembling in pectoral triceps, and gluteal muscles and adopted a base-wide stance. In conclusion, 2 and 3 mg/kg tramadol IV neither induced sedation nor prolonged HWR after thermal or electrical stimuli in conscious horses. The dose of 5 mg/kg tramadol IV produced excitement, and it is apparently unsuitable for clinical use.     

Two new cytotoxic isomeric indole alkaloids from the roots of Nauclea orientalis

A pair of new isomeric indole alkaloids, naucleaorals A (1) and B (2) were isolated from the roots of Nauclea orientalis. The structures of compounds 1 and 2 were fully characterized using spectroscopic data, and were tested for their cytotoxicity (HeLa and KB cells) and antimalarial activity. Compound 1 showed significant cytotoxicity to HeLa cells with an IC₅₀ value of 4.0 µg/mL, while compound 2 exhibited very modest cytotoxicity to both cell lines with IC₅₀ values of 7.8 and 9.5 µg/mL, respectively. Both compounds proved to be inactive in antimalarial assays (IC₅₀ > 10.00 µg/mL).