Evaluating mortality rates and causalities in a critically endangered felid across its whole distribution range

The conservation of endangered species requires accurate data, and knowledge of cause-specific mortality rates is one of the most important issues. In recent years, conservation programs for the critically endangered Iberian lynx Lynx pardinus have been developed on the basis of mortality data derived 30 years ago from the small Doñana population. Thus, there is an urgent need for an update of mortality rates and causes in both populations (Sierra Morena and Doñana). Here we use radio-tracking information from the whole range of the Iberian lynx to quantify mortality rates and identify their causes. Between 2006 and 2011, we radio-tagged 78 Iberian lynxes from its two remaining populations (39 from Sierra Morena and 39 from Doñana). Mortality events were evaluated to identify causes, and cause-specific annual mortality rates (AMR) were obtained using the nonparametric cumulative incidence function estimator. Overall, AMR was estimated at 0.16?±?0.05 (0.19?±?0.09 in Sierra Morena and 0.12?±?0.07 in Doñana). Disease was the main cause of mortality both for the whole population and the Doñana population. Poaching was the main cause of mortality in Sierra Morena. Our results suggest that the best strategy for conserving this species is to focus action on decreasing the fatal effect of disease and poaching. Given the possible existence of an underlying inbreeding-mediated immunosuppression, genetic management aimed at increasing the genetic diversity of this population is also recommended.     

Exposure to T-cycles of 22 and 23 h during lactation modifies the later dissociation of motor activity and temperature circadian rhythms in rats

Early environmental conditions may affect the development and manifestation of circadian rhythms. This study sought to determine whether the maintenance of rats under different T-cycles during lactation influences the subsequent degree of dissociation of the circadian rhythms of motor activity and core body temperature. Two groups of 22 day-old Wistar rats were kept after weaning under T-cycles of 22 h (T22) or 23 h (T23) for 70 days. Subsequently, they were kept in constant darkness (DD). Half of the animals in each group were born and reared under these experimental conditions, while the other half were reared until weaning under 24 h LD cycles (T24). Rats transferred from T24 to T22 or T23 showed two circadian components in motor activity and temperature, one entrained by light and the other free-running. In T22, there was also desynchronization between temperature and motor activity. Rats submitted to T23 from birth showed higher stability of the 23 h component than rats transferred from T24 to T23 after weaning. However, in comparison to rats born under T24 and subsequently changed to T22, animals submitted to T22 from birth showed shorter values of the period of the non-light-dependent component during T22, more aftereffects when transferred to DD, and a lack of desynchronization between motor activity and temperature. The results suggest that T-cycles in the early environment may modify overt rhythms by altering the internal coupling of the circadian pacemaker.     

Maintenance of rat taste buds in primary culture

The differentiated taste bud is a complex end organ consisting of multiple cell types with various morphological, immunocytochemical and electrophysiological characteristics. Individual taste cells have a limited lifespan and are regularly replaced by a proliferative basal cell population. The specific factors contributing to the maintenance of a differentiated taste bud are largely unknown. Supporting isolated taste buds in culture would allow controlled investigation of factors relevant to taste bud survival. Here we describe the culture and maintenance of isolated rat taste buds at room temperature and at 37 degrees C. Differentiated taste buds can be sustained for up to 14 days at room temperature and for 3-4 days at 37 degrees C. Over these periods individual cells within the cultured buds maintain an elongated morphology. Further, the taste cells remain electrically excitable and retain various proteins indicative of a differentiated phenotype. Despite the apparent health of differentiated taste cells, cell division occurs for only a short period following plating, suggesting that proliferating cells in the taste bud are quickly affected by isolation and culture.     

Candidemia by Species of the Candida parapsilosis Complex in Children’s Hospital: Prevalence, Biofilm Production and Antifungal Susceptibility

Opportunistic infections are an increasingly common problem in hospitals, and the yeast Candida parapsilosis has emerged as an important nosocomial pathogen. The aims of this study were to determine and compare (i) the prevalence rate among C. parapsilosis complex organisms isolated from blood in a public children’s hospital in São Paulo state, (ii) the ability of the complex C. parapsilosis species identified to produce biofilm and (iii) the antifungal susceptibility profiles. Forty-nine (49) specimens of isolated blood yeast were analyzed, previously identified as C. parapsilosis by conventional methods. After the molecular analysis, the isolates were characterized as C. parapsilosis sensu stricto (83.7 %), C. orthopsilosis (10.2 %) and C. metapsilosis (6.1 %). All species were able to form biofilm. The species with the highest biofilm production was C. parapsilosis sensu stricto, followed by C. orthopsilosis and further by C. metapsilosis. All of the strains have demonstrated similar susceptibility to fluconazole, caspofungin, voriconazole, cetoconazole and 5-flucytosine. Only one strain of C. parapsilosis was resistant to amphotericin B. Regarding itraconazole, 66.6 and 43.9 % isolates of C. metapsilosis and C. parapsilosis, respectively, have demonstrated to be susceptible dose-dependent, with one isolate of the latter species resistant to the drug. Candida parapsilosis sensu stricto has demonstrated to be the less susceptible, mainly to amphotericin B, caspofungin and “azoles” such as fluconazole. Therefore, C. metapsilosis and C. orthopsilosis are still involved in a restricted number of infections, but these data have become essential for there are very few studies of these species in Latin America.     

Light- and singlet oxygen-mediated antifungal activity of phenylphenalenone phytoalexins.

The light-induced singlet oxygen production and antifungal activity of phenylphenalenone phytoalexins isolated from infected banana plants (Musa acuminata) are reported. Upon absorption of light energy all studied phenylphenalenones sensitise the production of singlet oxygen in polar and non-polar media. Antifungal activity of these compounds towards Fusarium oxysporum is enhanced in the presence of light. These results, together with the correlation of IC50 values under illumination with the quantum yield of singlet oxygen production and the enhancing effect of D2O on the antifungal activity, suggest the intermediacy of singlet oxygen produced by electronic excitation of the phenylphenalenone phytoalexins.     

Effect of goniothalamin on the development of Ehrlich solid tumor in mice

In this work the antiproliferative activity of goniothalamin (1), both in racemic and in its enantiomeric pure forms, in a solid tumor experimental model using laboratory animals is described. The antiedematogenic activity displayed by racemic 1 in the carrageenan edema model in mice together with the reduction of Ehrlich solid tumor model suggest a relationship between anticancer and antiinflammatory activities with the antiinflammatory activity favoring the antiproliferative activity itself.     

Analysis of ECs and related compounds in plasma: artifactual isomerization and ex vivo enzymatic generation of 2-MGs

The analysis of peripheral endocannabinoids (ECs) is a good biomarker of the EC system. Their concentrations, from clinical studies, strongly depend on sample collection and time processing conditions taking place in clinical and laboratory settings. The analysis of 2-monoacylglycerols (MGs) (i.e., 2-arachidonoylglycerol or 2-oleoylglycerol) is a particularly challenging issue because of their ex vivo formation and chemical isomerization that occur after blood sample collection. We provide evidence that their ex vivo formation can be minimized by adding Orlistat, an enzymatic lipase inhibitor, to plasma. Taking into consideration the low cost of Orlistat, we recommend its addition to plasma collecting tubes while maintaining sample cold chain until storage. We have validated a method for the determination of the EC profile of a range of MGs and N-acylethanolamides in plasma that preserves the original isomer ratio of MGs. Nevertheless, the chemical isomerization of 2-MGs can only be avoided by an immediate processing and analysis of samples due to their instability during conservation. We believe that this new methodology can aid in the harmonization of the measurement of ECs and related compounds in clinical samples.     

Activation of RAT erythrocyte phosphofructokinase by AMP and by non-physiological concentrations of Cyclic AMP

Summary Cyclic AMP (300µ m) activates phosphofructokinase from dialyzed haemolysates of mature rat erythrocytes. The main conclusions are: a) Cyclic AMP, at pH 7.1 and low concentrations of fructose-6-phosphate, is able to reverse the inhibition produced by different amounts of ATP (up to 1.5mm). b) The cyclic nucleotide is a positive allosteric effector of the enzyme as shown by the displacement of sigmoidal fructose-6-phosphate saturation curve to hyperbolic kinetics in the presence of inhibitory concentrations (1.5mm) of ATP. c) Cyclic AMP has no significant influence as deinhibitor of phosphofructokinase either at pH 7.1 and non-inhibitory levels (0.25mm) of ATP or at pH 8.1 and inhibitory (1.5mm) of non-inhibitory (0.25mm) concentrations of ATP. Similar conclusions were obtained with 300µ m AMP but not at a lower concentration (3µ m) with both nucleotides.The comparison of cyclic AMP results with those obtained under similar concentrations of AMP suggest that cyclic AMP is really only an in vitro modulator of the enzyme from rat erythrocytes, presumably at an AMP regulatory site, since non-physiological concentrations are required to act as deinhibitor.     

Proline metabolism in response to nitrogen deficiency in French Bean plants (Phaseolus vulgaris L. cv Strike)

The objective of the present work was to determine the impact ofnitrogen deficiency on proline metabolism in French Bean plants(Phaseolus vulgaris L. cv. Strike). The nitrogen wasapplied to the nutrient solution in the form of NH₄NO₃ at1.45 mM (N1), 2.90mM (N2) and 5.80mM (N3, optimal level). Our results indicateNdeficiency is characterised by a decline in proline accumulation both in theroot and leaves, fundamentally because proline degradation is encouraged by thestimulation of the enzyme proline dehydrogenase. By contrast, under conditionsof adequate N (N3), proline levels rise due to the action of ornithine,suggesting predominance of the ornithine pathway over the glutamine pathway, inaddition to the inhibition of proline dehydrogenase activity.