Selenium improves photosynthesis and induces ultrastructural changes but does not alleviate cadmium-stress damages in tomato plants

Protoplasma - The application of Se to plants growing under Cd contamination may become an alternative strategy to minimize Cd damage. However, there is no specific information available regarding...     

Degrees of honesty: cleaning by the redlip cleaner wrasse Labroides rubrolabiatus

Cleaning symbioses among coral reef fishes are highly variable. Cleanerfishes vary in how much they cooperate with (i.e. remove only ectoparasites) or cheat (i.e. bite healthy tissue, scales or mucus) on their fish clients. As a result, clients use various strategies to enforce cooperation by cleaners (e.g. punishment or partner choice), and cleaners use tactile stimulation to manipulate cheated client behaviour. We provide the first detailed observations of cleaning behaviour of the redlip cleaner wrasse Labroides rubrolabiatus and ask where interactions with this cleanerfish lie on the continuum of cleanerfish honesty, client control, and cleanerfish manipulation. Ninety per cent of redlip cleaner wrasses took jolt-inducing cheating bites from their clients, but they did so at a very low rate (~ 2 jolts per 100 s inspection). Retaliatory chases by clients were uncommon. Three-quarters (30 of 40) of cleaner wrasses used tactile stimulation on their clients, but rarely did so to reconcile with cheated clients. Instead, the majority (70%) of tactile stimulation events targeted a passing client that then stopped for inspection. The relationship between redlip cleaner wrasses and their clients appears to be less conflictual than those documented in other Labroides cleanerfishes. Future studies should test whether this low level of conflict is consistent across space and time and is underpinned by a preference for ectoparasites over other client-gleaned items. As an active cleaner that appears to take few cheating bites from their clients, L. rubrolabiatus has the potential to be as important a driver of fish health and community structure on coral reefs as its better-known relatives.

     

Improvement in cyst recovery and molecular detection of Giardia duodenalis from stool samples

Molecular Biology Reports - Molecular detection of Giardia duodenalis by polymerase chain reaction (PCR) is difficult in faecal samples due to inhibitors that contaminate DNA preparations, or due...     

Spatiotemporal variations in density and biomass of rocky reef fish in a biogeographic climatic transition zone: trends over 9 years,inside and outside the only nearshore no-take marine-protected area on the southern Brazilian coast

Biogeographical transition zones are important areas to investigate evolutionary ecological questions, but long-term population monitoring is needed to better understand ecological processes that govern population variations in such edge environments. The southernmost Brazilian rocky reefs are the southern limit of distribution for 96% of the tropical ichthyofauna of the western Atlantic. The Arvoredo Marine Biological Reserve is the only nearshore no-take marine-protected area (MPA) located in this transition zone. The main aim was to investigate how the populations of rocky reef fish species vary in density and biomass in space and over time, inside and outside the Arvoredo MPA. This study presents results based on a 9 year (2008–2017) underwater visual census monitoring study to evaluate the density and biomass of key fish species. Variations in density and biomass were detected for most species. Factors and mechanisms that may have influenced spatial variation are habitat structural complexity and protection from fisheries. Temporal variations, otherwise, may have been influenced by species proximity to their distributional limit, in synergy with density-dependent mechanisms and stochastic winter temperature oscillations. The MPAs harbour higher density and biomass for most species. Nonetheless, a prominent temporal decline in the recruitment of Epinephelus marginatus calls into question the continuous effectiveness of the MPA.     

The flavonoid chrysin attenuates colorectal pathological remodeling reducing the number and severity of pre-neoplastic lesions in rats exposed to the carcinogen 1,2-dimethylhydrazine

Phenolic compounds are naturally occurring, bioactive substances with marked antioxidant and anti-inflammatory potential. The flavonoid chrysin, found in high levels in honey bee propolis, inhibits the activity of enzymes involved in carcinogenesis. We have investigated the effect of chrysin on pre-neoplastic colorectal lesions (ACF, aberrant crypt foci) in a rat model of chemical carcinogenesis induced by 1,2-dimethylhydrazine (DMH). Female Wistar rats weighing 137.2?±?24.3 g received weekly one subcutaneous injection of DMH (20 mg/kg) for 10 weeks. The animals were divided into five groups each with seven animals: Group 1, 0.9% saline; Group 2, DMH+0.9% saline; Group 3, DMH+chrysin (10 mg/kg); Group 4, DMH+chrysin (100 mg/kg); Group 5, DMH+chrysin (200 mg/kg). Groups 2 and 3 showed a significant increase in ACF number, nucleolus organizer regions per enterocyte nucleus and nitrite/nitrate serum levels compared with Group 1. Groups 4 and 5 presented a significant reduction in all these parameters compared with Group 2. The levels of antioxidant minerals (copper, magnesium, selenium, zinc) and the number of enteroendocrine and mucin-producing cells were significantly reduced in Groups 2 and 3 but were similar in Groups 4 and 5 compared with Group 1. Chrysin, at 100 mg/kg and 200 mg/kg, was effective in attenuating pathological colorectal remodeling, reducing the number of pre-neoplastic lesions in rats exposed to DMH. Some of these effects might be attributable to the recovery of antioxidant mineral levels, a reduction in systemic nitrosative stress and an inhibition of the cellular proliferation induced by this flavonoid.     

Traffic of Leukocytes and Cytokine Up-regulation in the Central Nervous System in a Murine Model of Neuroparacoccidioidomycosis

Background

Paracoccidioidomycosis is the most important systemic mycosis in South America. In the last decades, it was observed that central nervous system involvement is frequent, occurring in 12.5 % of the cases. The aim of this study was to report the early inflammatory changes associated with an experimental model of neuroparacoccidioidomycosis (NPCM).

Methods

C57BL/6 mice were infected by intracranial route with 10⁶ yeast cells of PB18 strain of Paracoccidioides brasiliensis. Leukocyte–endothelium interactions were assessed by intravital microscopy 1, 2, 4, and 8 weeks post-infection (p.i.). Chemokine/cytokine levels in the brain and histopathological changes were assessed 4 and 8 weeks p.i..

Results

Intravital microscopy analysis revealed a progressive increase in leukocyte recruitment in the vessels of pia mater with a peak 4 weeks p.i. The chemokine CXCL9 was increased at 4 and 8 weeks p.i., while CCL2, CCL3, and CCL5 were increased at 8 weeks p.i. Histopathological analysis revealed the infiltration of inflammatory cells and the development of progressive granulomatous meningoencephalitis. CCL3 levels correlated with clinical manifestations of disease, as measured by the SHIRPA battery.

Conclusions

The experimental model of NPCM showed increased leukocyte recruitment associated with increased expression of chemokines and nervous tissue inflammation which correlated with clinical manifestations of disease.     

Reproducibility of Positive Results for the Detection of Serum Galactomannan by Platelia™ Aspergillus EIA

Galactomannan (GM) was recently included in consensus guidelines as an indirect mycological criterion for the diagnosis of invasive aspergillosis. Currently, there is an enzyme immunoassay available to detect GM in biological samples, the Platelia? Aspergillus EIA. In this study, the reproducibility of positive results obtained using this assay was evaluated using serum samples from neutropenic patients. A trend toward lower values was observed, and 55 %(27/49) of positive results were negative after retesting. A low reproducibility of positive results for the detection of GM in serum was observed.