Predatory threat of harpy eagles for yellow-breasted capuchin monkeys in the Atlantic Forest

We describe seven encounters between different harpy eagle individuals (Harpia harpyja) and a group of yellow-breasted capuchin monkeys (Sapajus xanthosternos) in Una Biological Reserve. These interactions lasted 58 min on average. In each of those encounters, the capuchin monkeys used particular behavioral strategies against the harpy eagle that were not employed in reaction to other aerial predators. We did not observe any successful predation events, but after one of those encounters an infant disappeared from the capuchin group. As a whole, these observations indicate that the presence of harpy eagles in the group’s home range increases predation risk for capuchin monkeys. The present report also suggests a reoccupation by H. harpyja of this area, as no previous recent records identify harpy eagle occurrence in Una Biological Reserve.     

Articles by Latin American Authors in Prestigious Journals Have Fewer Citations

Background

The journal Impact factor (IF) is generally accepted to be a good measurement of the relevance/quality of articles that a journal publishes. In spite of an, apparently, homogenous peer-review process for a given journal, we hypothesize that the country affiliation of authors from developing Latin American (LA) countries affects the IF of a journal detrimentally.

Methodology/Principal Findings

Seven prestigious international journals, one multidisciplinary journal and six serving specific branches of science, were examined in terms of their IF in the Web of Science. Two subsets of each journal were then selected to evaluate the influence of author''s affiliation on the IF. They comprised contributions (i) with authorship from four Latin American (LA) countries (Argentina, Brazil, Chile and Mexico) and (ii) with authorship from five developed countries (England, France, Germany, Japan and USA). Both subsets were further subdivided into two groups: articles with authorship from one country only and collaborative articles with authorship from other countries. Articles from the five developed countries had IF close to the overall IF of the journals and the influence of collaboration on this value was minor. In the case of LA articles the effect of collaboration (virtually all with developed countries) was significant. The IFs for non-collaborative articles averaged 66% of the overall IF of the journals whereas the articles in collaboration raised the IFs to values close to the overall IF.

Conclusion/Significance

The study shows a significantly lower IF in the group of the subsets of non-collaborative LA articles and thus that country affiliation of authors from non-developed LA countries does affect the IF of a journal detrimentally. There are no data to indicate whether the lower IFs of LA articles were due to their inherent inferior quality/relevance or psycho-social trend towards under-citation of articles from these countries. However, further study is required since there are foreseeable consequences of this trend as it may stimulate strategies by editors to turn down articles that tend to be under-cited.     

Dexamethasone inhibits BAFF expression in fibroblast-like synoviocytes from patients with rheumatoid arthritis

Fibroblast-like synoviocytes (FLS) play a major role in the pathogenesis of rheumatoid arthritis (RA). FLS isolated from patients with RA (FLS-RA) express B cell-activating factor belonging to the TNF family (BAFF), a cytokine that has been associated with the onset and progression of RA. Glucocorticoids are powerful anti-inflammatory drugs used in the treatment of RA. In the present study, we examined the effect of dexamethasone (Dex) on constitutive and TNF-alpha- and IFN-gamma-induced BAFF expression in FLS-RA. BAFF mRNA expression and soluble BAFF were determined by RT-PCR and ELISA, respectively. The results showed that constitutive BAFF mRNA expression was inhibited by Dex in a dose- and time-dependent manner. Also, Dex inhibited the secretion of BAFF in a time-dependent manner reaching 76% of inhibition 72 h after treatment. Moreover, Dex suppressed both mRNA and protein BAFF expression induced by TNF-alpha but had no effect on IFN-gamma-induced BAFF expression. In comparison with B cells cultured alone, B cells co-cultured with FLS-RA exhibited a higher survival, which was inhibited when FLS-RA were pretreated with Dex. However, the enhanced B cell survival was reestablished by the addition of rhBAFF. Therefore, Dex is a potent inhibitor of constitutive and TNF-alpha-induced BAFF expression in FLS-RA.     

Robust acinar cell transgene expression of CreErT via BAC recombineering

Pancreatic acinar cells are critical in gastrointestinal physiology and pancreatitis and may be involved in pancreatic cancer. Previously, a short rat pancreatic elastase promoter has been widely utilized to control acinar cell transgene expression. However, this partial sequence does not confer robust and stable expression. In this study, we tested the hypothesis that a transgene employing bacterial-artificial-chromosome (BAC) technology to express a tamoxifen-regulated Cre recombinase from a full-length mouse elastase gene (BAC-Ela-CreErT) would be more robust and stable. When founders were crossed with Rosa26 reporter mice nearly 100% of acini expressed beta-galactosidase after tamoxifen treatment. The expression was specific for pancreatic acinar cells and these characteristics have remained stable for 2 years. However, because of high levels of expression in differentiated acinar cells, this construct is tamoxifen independent in approximately 50% of adult acinar cells. This model of pancreatic acinar specific Cre expression is a powerful tool for future transgenic and knockout studies.     

Stereoselective disposition of S- and R-licarbazepine in mice

The stereoselective disposition of S-licarbazepine (S-Lic) and R-licarbazepine (R-Lic) was investigated in plasma, brain, liver, and kidney tissues after their individual administration (350 mg/kg) to mice by oral gavage. Plasma, brain, liver, and kidney concentrations of licarbazepine enantiomers and their metabolites were determined over the time by a validated chiral HPLC-UV method. The mean concentration data, attained at each time point, were analyzed using a non-compartmental model. S-Lic and R-Lic were rapidly absorbed from gastrointestinal tract of mouse and immediately distributed to tissues supplied with high blood flow rates. Both licarbazepine enantiomers were metabolized to a small extent, each parent compound being mainly responsible for the systemic and tissue drug exposure. The stereoselectivity in the metabolism and distribution of S- and R-Lic was easily identified. An additional metabolite was detected following R-Lic administration and S-Lic showed a particular predisposition for hepatic and renal accumulation. Stereoselective processes were also identified at the blood-brain barrier, with the brain exposure to S-Lic almost twice that of R-Lic. Another finding, reported here for the first time, was the ability of the mouse to perform the chiral inversion of S- and R-Lic, albeit to a small extent.     

Colorimetric microwell plate reverse-hybridization assay for Mycobacterium tuberculosis detection

Direct smear examination using Ziehl-Neelsen staining for pulmonary tuberculosis (PTB) diagnosis is inexpensive and easy to use, but has the major limitation of low sensitivity. Rapid molecular methods are becoming more widely available in centralized laboratories, but they depend on timely reporting of results and strict quality assurance obtainable only from costly commercial kits available in high burden nations. This study describes a pre-commercial colorimetric method, Detect-TB, for detecting Mycobacterium tuberculosis DNA in which an oligonucleotide probe is fixed onto wells of microwell plates and hybridized with biotinylated polymerase chain reaction amplification products derived from clinical samples. The probe is capable of hybridising with the IS6110 insertion element and was used to specifically recognise the M. tuberculosis complex. When combined with an improved silica-based DNA extraction method, the sensitivity of the test was 50 colony-forming units of the M. tuberculosis reference strain H37Rv. The results that were in agreement with reference detection methods were observed in 95.2% (453/476) of samples included in the analysis. Sensitivity and specificity for 301 induced sputum samples and 175 spontaneous sputum samples were 85% and 98%, and 94% and 100%, respectively. This colorimetric method showed similar specificity to that described for commercially available kits and may provide an important contribution for PTB diagnosis.     

Study of the cytotoxic activity of Styrax camporum extract and its chemical markers,egonol and homoegonol

The benzofuran lignans egonol and homoegonol are found in all species of the genus Styrax. Since natural products are important sources of new anticancer drugs, this study evaluated the cytotoxic activity of a hydroalcoholic extract of the stems of S. camporum (SCHE) and their chemical markers, egonol (EG) and homoegonol (HE), against different tumor cell lines (B16F10, MCF-7, HeLa, HepG2, and MO59J). A normal human cell line (GM07492A) was included. Cytotoxic activity was evaluated at different treatment times (24, 48 and 72 h) using the XTT assay. More effective results were observed after 72 h of treatment. The lowest IC₅₀ values were found for the HepG2 cell line, ranging from 11.2 to 55.0 µg/mL. The combination of EG and HE exerted higher cytotoxic activity than SCHE or treatment with either lignan alone, with the lowest IC₅₀ (13.31 µg/mL) being observed for the MCF-7 line. Furthermore, treatment with these lignans was significantly more cytotoxic for some tumor cell lines compared to the normal cell line, GM07492A, indicating selectivity. These results suggest that these lignans may be used to treat cancer without affecting normal cells.     

Contemporary pollen flow,mating patterns and effective population size inferred from paternity analysis in a small fragmented population of the Neotropical tree <Emphasis Type="Italic">Copaifera langsdorffii</Emphasis> Desf. (Leguminosae-Caesalpinioideae)

Pollen flow and dispersal patterns were investigated in a small, isolated forest fragment of the Neotropical insect pollinated tree Copaifera langsdorffii, using paternity analysis and eight microsatellite loci. We also investigated the coancestry and effective population size of progeny arrays for conservation and environmental restoration purposes. Open-pollinated seeds were collected from 15 seed trees within the forest fragment, in which all adult trees were mapped, measured and genotyped. Twenty seeds were also collected from the nearest neighbor tree located 1.2 km from the forest fragment. Our results show that levels of genetic diversity were significantly higher in adults than offspring and significant levels of inbreeding were detected in offspring (F = 0.226). From paternity analysis, we observed low levels of selfing (s = 8%) and pollen immigration (m = 8%) in the fragment, but very high levels were detected for the isolated tree (s = 20%; m = 75%), indicating that the population and the tree are not reproductively isolated and are connected by patterns of long distance pollen dispersal (maximum detected 1,420 m). Within the forest fragment, the pattern of pollen dispersal was a near neighbor pattern with 49% of the pollen being dispersed within 50 m. The effective population size of the progeny array was low, indicating the need to collect seeds from a large number of seed trees (at least 76) for conservation purposes. The results show that the spatial isolation of the population and isolated tree due to forest fragmentation has not disrupted genetic connectivity; however, spatial isolation does seem to increase selfing and correlated mating.     

Antifungal Activity of Phlorotannins against Dermatophytes and Yeasts: Approaches to the Mechanism of Action and Influence on Candida albicans Virulence Factor

In the last few decades, fungal infections, particularly nosocomial, increased all around the world. This increment stimulated the search for new antifungal agents, especially those derived from nature. Among natural products, those from marine sources have gained prominence in the last years. Purified phlorotannins extracts from three brown seaweeds (Cystoseira nodicaulis (Withering) M. Roberts, Cystoseira usneoides (Linnaeus) M. Roberts and Fucus spiralis Linnaeus) were screened for their antifungal activity against human pathogenic yeast and filamentous fungi. The purified phlorotannins extracts from the studied seaweeds displayed fungistatic and fungicidal activity against yeast and dermatophytes, respectively, pointing to their interest as anti-dermatophyte agent. C. albicans ATCC 10231 was the most susceptible among yeast, while Epidermophyton floccosum and Trichophyton rubrum were the most susceptible among dermatophytes. Since the antifungal mechanism constitutes an important strategy for limiting the emergence of resistance to the commercially available agents, the mechanism of action of purified phlorotannins extracts was approached. C. nodicaulis and C. usneoides seem to act by affecting the ergosterol composition of the cell membrane of yeast and dermatophyte, respectively. F. spiralis influenced the dermatophyte cell wall composition by reducing the levels of chitin. Phlorotannins also seem to affect the respiratory chain function, as all of the studied species significantly increased the activity of mitochondrial dehydrogenases and increased the incorporation of rhodamine 123 by yeast cells. Phlorotannins from F. spiralis inhibited the dimorphic transition of Candida albicans, leading to the formation of pseudohyphae with diminished capacity to adhere to epithelial cells. This finding is associated with a decrease of C. albicans virulence and capacity to invade host cells and can be potentially interesting for combined antifungal therapy, namely for the control of invasive candidiasis.     

Upregulation of apical NHE3 in renal OK cells overexpressing the rodent alpha(1)-subunit of the Na(+) pump

Vectorial Na(+) reabsorption across the proximal tubule is mediated by apical entry of Na(+), primarily via Na(+)/H(+) exchanger isoform 3 (NHE3), and basolateral extrusion via the Na(+) pump (Na(+)-K(+)-ATPase). We hypothesized that regulation of Na(+) reabsorption should involve not only the activity of the basolateral Na(+)-K(+)-ATPase, but also the apical NHE3, in a concerted manner. To generate a cell line that overexpresses Na(+)-K(+)-ATPase, opossum kidney (OK) cells were transfected with the rodent Na(+)-K(+)-ATPase alpha(1)-subunit (pCMV ouabain vector), and native cells were used as a control. The existence of distinct functional classes of Na(+)-K(+)-ATPase in wild-type and transfected cells was confirmed by the inhibition profile of Na(+)-K(+)-ATPase activity by ouabain. In contrast to wild-type cells, transfected cells exhibited two IC(50) values for ouabain: the first value was similar to the IC(50) of control cells, and the second value was 2 log units greater than the first, consistent with the presence of rat and opossum alpha(1)-isozymes. It is shown that transfection of OK cells with Na(+)-K(+)-ATPase increased Na(+)-K(+)-ATPase and NHE3 activities. This was associated with overexpression of the Na(+)-K(+)-ATPase alpha(1)-subunit and NHE3 in transfected OK cells. The abundance of the Na(+)-K(+)-ATPase beta(1)-subunit was slightly lower in transfected OK cells. In conclusion, the increase in expression and function of Na(+)-K(+)-ATPase in cells transfected with the rodent Na(+) pump alpha(1)-subunit cDNA is expected to stimulate apical Na(+) influx into the cells, thereby accounting for the observed stimulation of the apical NHE3 activity.