Spray Nozzles,Pressures, Additives and Stirring Time on Viability and Pathogenicity of Entomopathogenic Nematodes (Nematoda: Rhabditida) for Greenhouses

The objective of this study was to evaluate different strategies for the application of entomopathogenic nematodes (EPN). Three different models of spray nozzles with air induction (AI 11003, TTI 11003 and AD-IA 11004), three spray pressures (207, 413 and 720 kPa), four different additives for tank mixtures (cane molasses, mineral oil, vegetable oil and glycerin) and the influence of tank mixture stirring time were all evaluated for their effect on EPN (Steinernema feltiae) viability and pathogenicity. The different nozzles, at pressures of up to 620 kPa, were found to be compatible with S. feltiae. Vegetable oil, mineral oil and molasses were found to be compatible adjuvants for S. feltiae, and stirring in a motorized backpack sprayer for 30 minutes did not impact the viability or pathogenicity of this nematode. Appropriate techniques for the application of nematodes with backpack sprayers are discussed.     

Synthesis and biological evaluation against Leishmania amazonensis of a series of alkyl-substituted benzophenones

Nine O-alkyl and O-prenyl derivatives were synthesized from commercial 2,4-dihydroxybenzophenone, 4,e4,4′-dihydroxybenzophenone and were evaluated for their leishmanicidal activity against promastigote forms of Leishmania amazonensis, as well their toxicity in murine macrophages. All derivatives exhibited better biological activity than their hydroxylated benzophenones precursors, and new compound LFQM-123 (3c) was 250-fold more active than its precursor 4,4′-dihydroxybenzophenone (3). Moreover, some of the results were comparable to the standard drug Amphotericin B, suggesting that the increase in lipophilicity could facilitate protozoa membrane permeation. In this study we confirmed that benzophenone derivatives exhibit leishmanicidal properties, with relatively low toxicity, and thus could be exploited as promise prototypes for the design and development of new drug for the treatment of leishmaniasis.     

Trophic polymorphism, habitat and diet segregation in Percichthys trucha (Pisces: Percichthyidae) in the Andes

Divergent natural selection affecting specific trait combinations that lead to greater efficiency in resource exploitation is believed to be a major mechanism leading to trophic polymorphism and adaptive radiation. We present evidence of trophic polymorphism involving two benthic morphs within Percichthys trucha , a fish endemic to temperate South America. In a series of lakes located in the southern Andes, we found two morphs of P. trucha that could be distinguished on the basis of gill raker length and five other morphological measures, most of which are likely associated with the use of food resources. The differences were consistent across all lakes examined, and were correlated with habitat use and diet. Individuals with longer gill rakers were more abundant in the littoral zone (littoral morph) while the short gill-raker morph was more abundant at 10 m depth and deeper (deep benthic morph). Both morphs fed primarily on benthic invertebrates, but the littoral morph fed more on larval Anisoptera than did the deep benthic morph. Phenotypic correlations among traits were high for the littoral morph, but low and non-significant for the deep-benthic morph. We suggest that gill raker length may influence the relative efficiency of suction feeding for the two morphs. This is the first evidence of trophic polymorphism in fishes from temperate South America.     

Leucine and HMB Differentially Modulate Proteasome System in Skeletal Muscle under Different Sarcopenic Conditions

In the present study we have compared the effects of leucine supplementation and its metabolite β-hydroxy-β-methyl butyrate (HMB) on the ubiquitin-proteasome system and the PI3K/Akt pathway during two distinct atrophic conditions, hindlimb immobilization and dexamethasone treatment. Leucine supplementation was able to minimize the reduction in rat soleus mass driven by immobilization. On the other hand, leucine supplementation was unable to provide protection against soleus mass loss in dexamethasone treated rats. Interestingly, HMB supplementation was unable to provide protection against mass loss in all treatments. While solely fiber type I cross sectional area (CSA) was protected in immobilized soleus of leucine-supplemented rats, none of the fiber types were protected by leucine supplementation in rats under dexamethasone treatment. In addition and in line with muscle mass results, HMB treatment did not attenuate CSA decrease in all fiber types against either immobilization or dexamethasone treatment. While leucine supplementation was able to minimize increased expression of both Mafbx/Atrogin and MuRF1 in immobilized rats, leucine was only able to minimize Mafbx/Atrogin in dexamethasone treated rats. In contrast, HMB was unable to restrain the increase in those atrogenes in immobilized rats, but in dexamethasone treated rats, HMB minimized increased expression of Mafbx/Atrogin. The amount of ubiquitinated proteins, as expected, was increased in immobilized and dexamethasone treated rats and only leucine was able to block this increase in immobilized rats but not in dexamethasone treated rats. Leucine supplementation maintained soleus tetanic peak force in immobilized rats at normal level. On the other hand, HMB treatment failed to maintain tetanic peak force regardless of treatment. The present data suggested that the anti-atrophic effects of leucine are not mediated by its metabolite HMB.     

Immune Evasion by Helicobacter pylori: Gastric Spiral Bacteria Lack Surface Immunoglobulin Deposition and Reactivity with Homologous Antibodies

Background. Helicobacter pylori infection persists in the presence of potent serum and gastric mucosal anti-body responses against bacterial antigens. The aim of this article is to report on a study determine whether there is antibody deposition on H. pylori in vivo in the stomach of infected patients and whether gastric and cultured forms of H. pylori differ in their antibody reactivity.
Materials and Methods. Serum, gastric biopsies, and antral brushings were obtained from 10 patients having endoscopy. H. pylori was cultured from gastric biopsies. Bacterial samples were stained directly for immunoglobulin deposition and indirectly using rabbit antiurease serum or patient serum. Samples were examined by immunofluorescence microscopy and flow cytometry.
Results. Although spiral bacteria could be identified easily by acridine orange staining and antiurease staining of gastric brushings from H. pylori infected patients, gastric bacteria did not have detectable IgG or IgA present, and only one of five samples could be stained for IgG and IgA indirectly using patient serum. In contrast, cultured bacteria could be stained readily with homologous serum for IgG and IgA in the majority of cases. Low pH inhibited immunoglobulin reactivity with cultured H. pylori.
Conclusions. Gastric H. pylori may evade humoral defense owing to poor deposition of immunoglobulin in the gastric environment or failure to express surface antigens that are present on cultured forms of H. pylori.     

Testing methods to estimate abundance of Magellanic Penguins Spheniscus magellanicus

Capsule Using simulations in a geographical information system our results showed that systematic sampling with quadrats was the most accurate, precise and cost-effective method to survey Magellanic Penguin colonies.

Aims To determine which sampling method gives better estimations of penguin abundance.

Methods A virtual colony was generated deriving spatial parameters from a real survey and applying Kriging interpolation. Three sampling methods were then applied on this virtual colony: random sampling with quadrats; systematic sampling with quadrats; systematic sampling with fixed-width transects. The estimated abundance for each trial was compared to the abundance of the virtual colony to have a measure of accuracy and precision.

Results Systematic sampling with quadrats estimated penguin abundance better than random or systematic sampling with transects since it achieved 100% accuracy and great precision after sampling only 2.1% of the virtual colony.

Conclusion The use of a simulated colony allowed the comparison of several sampling methods traditionally used in Magellanic Penguin surveys. The results of this study are important in order to standardize sampling protocols for Magellanic Penguins and to have more comparable estimations to detect trends over time. Also, the methodological approach used here could be used to assess sampling methods for other colonial bird species.     

Alien parasite hitchhikes to Patagonia on invasive bumblebee

The worldwide trade in bumblebees can lead to the spread of diseases, which in turn has been claimed as a factor in bumblebee decline. Populations of the introduced Bombus terrestris, which invaded NW Patagonia, Argentina, in 2006, harbor the highly pathogenic protozoan Apicystis bombi. We asked whether A. bombi had been co-introduced with B. terrestris, and if so, whether spillover occurred to the two resident bumblebee species in the region: the introduced European Bombus ruderatus and the native Bombus dahlbomii. We searched for A. bombi by means of PCR in samples of B. ruderatus and B. dahlbomii collected before and after the invasion of B. terrestris and in samples of the latter. We found no A. bombi in samples of B. ruderatus and B. dahlbomii collected before B. terrestris invasion, whereas post invasion, A. bombi was present in all 3 species. The identity of the parasite was established by sequencing the 18S region, which was identical for the three bumblebee species and also matched the European sequence, confirming it to be A. bombi. This is the first report of A. bombi in B. ruderatus and B. dahlbomii. Moreover, our results suggest that Patagonia had been free of A. bombi until this parasite was co-introduced with B. terrestris, and spilled over in situ to these two previously resident species. Finally, our findings provide indirect circumstantial evidence of a potential link between the population collapse and geographic retraction of B. dahlbomii and the introduction of this novel parasite.     

Alcoholism and coagulating gland: Androgen and insulin like growth factor-1 receptor features

The aim of this work was to characterize the structural and molecular changes in the coagulating gland from rats submitted to long-term alcohol treatment, as well as the possibility of recovery of these parameters after interrupting the alcohol administration. Ten Wistar and twenty UChB rats were divided into: Control group received tap water; Alcoholic group received 10% (v/v) ethanol daily for 150 days; and Abstinent group, received 10% (v/v) ethanol daily for 120 days and then tap water like the control for another 30 days. After 150 days, samples from the coagulating glands were processed for morphological and immunohistochemical analyses. The results showed atrophied epithelium and hypertrophied stroma, especially in the alcoholic group. Intensed androgen receptor (AR) immunolocalization was verified in the epithelium and weak in the stroma of the control group in relation to the other groups. Intensed insulin-like growth factor receptor-1 (IGFR-1) immunolocalization was verified in the stroma of the alcoholic and abstinent groups. Thus, it could be concluded that the excessive alcohol consumption caused morphological and molecular changes in the coagulating gland, characterizing the inverse relation of AR and IGFR-1 localization. The alcohol was an important factor in cellular mitosis occurrence, which could be fundamental element involved in glandular lesions.