Water conditions influence the detectability of Crossodactylus gaudichaudii (Anura,Hylodidae) in streams of the Atlantic Forest

Stream-dwelling amphibians' occurrence, behaviour and reproductive success are strongly influenced by dynamic abiotic factors, for example, water flow and spray. These factors can disproportionately affect these frogs due to their dependency on specific favourable conditions for development and incapacity to disperse from unfavourable environments. We analysed the influence of environmental covariates on the detectability of Crossodactylus gaudichaudii, an amphibian species endemic to streams in the Brazilian Atlantic Forest. We conducted sampling in the streams of the Duas Bocas Biological Reserve, Brazil, and we measured air and water temperature, air humidity and pH of water on each sampling occasion. We estimated the effects of variables on the detectability of the species using single-season occupancy models. Our results indicated that the detectability of the species increases on occasions with higher water temperatures (24–26°C) and lower pH (5.0–5.5). We investigated the influence of these covariates only on the detectability of adult frogs, but it is likely that the physiochemical properties of stream water are more important to aquatic larvae, and hence, the probability of their detection. Given this, further studies should examine the relevance of covariates on the detectability of adult frogs as well as larvae.     

Environmental gradients in a southern Europe estuarine system: Ria de Aveiro,Portugal implications for soft bottom macrofauna colonization

Four seasonal sampling surveys were carried out between December 1985 and September 1986 in Canal de Mira (Ria de Aveiro, Portugal). A total of 40 sampling stations, distributed over 13 transects, was used. Salinity, temperature, dissolved oxygen and pH of the water mass were measured. Sediment temperature, and salinity and pH of interstitial water were determined. Sediment variables also included granulometric composition and organic matter contents. Bottom macrofauna samples were collected at each station. Ordination (PCA and MDS) and classification of the sampling stations were performed, using the physicochemical and the biological data sets separately. Average linkage cluster analysis using the unweighted paired-group method, arithmetic averages, was used for both sets of data. With a salinity range from 35.1‰ to 0.0‰, Canal de Mira behaves like a tidally and seasonally poikilohaline estuary. Water temperature (8.5–24.7°C) decreased along the channel towards its inner part during the cold season; an inverse and more pronounced trend was observed during the hot season. Dissolved oxygen contents was generally high during the day (50% to 240% saturation). Oversaturation was observed throughout the growing season, with peaks in areas with large amounts of rooted vegetation. The pH values, largely correlated with dissolved oxygen, ranged from 6.8 to 8.9. Four types of sediment were present in Canal de Mira, medium and muddy sands being dominant. Two major gradients were identified: (i) a typical longitudinal estuarine gradient, associated with distance from the mouth, representing physicochemical variables such as tidal amplitude, salinity and temperature; this gradient was accompanied by an upstream increase in dominance; the community composition changes were mainly related to salinity; (ii) a lateral gradient, related to current velocity, depth and sediment composition; the subtidal community had a comparatively low species richness and abundance. Groups of stations could be recognized along the environmental gradients. Benthic community changes, however, appeared to be gradual rather than marked by abrupt transitions.     

PYK2 is overexpressed in chronic lymphocytic leukaemia: A potential new therapeutic target

Chronic Lymphocytic Leukaemia (CLL) is the most common adult B-cell leukaemia and despite improvement in patients' outcome, following the use of targeted therapies, it remains incurable. CLL supportive microenvironment plays a key role in both CLL progression and drug resistance through signals that can be sensed by the main components of the focal adhesion complex, such as FAK and PYK2 kinases. Dysregulations of both kinases have been observed in several metastatic cancers, but their role in haematological malignancies is still poorly defined. We characterized FAK and PYK2 expression and observed that PYK2 expression is higher in leukaemic B cells and its overexpression significantly correlates with their malignant transformation. When targeting both FAK and PYK2 with the specific inhibitor defactinib, we observed a dose–response effect on CLL cells viability and survival. In vivo treatment of a CLL mouse model showed a decrease of the leukaemic clone in all the lymphoid organs along with a significant reduction of macrophages and of the spleen weight and size. Our results first define a possible prognostic value for PYK2 in CLL, and show that both FAK and PYK2 might become putative targets for both CLL and its microenvironment (e.g. macrophages), thus paving the way to an innovative therapeutic strategy.     

Design and preclinical testing of an anti-CD41 CAR T cell for the treatment of acute megakaryoblastic leukaemia

Acute megakaryoblastic leukaemia (AMkL) is a rare subtype of acute myeloid leukaemia (AML) representing 5% of all reported cases, and frequently diagnosed in children with Down syndrome. Patients diagnosed with AMkL have low overall survival and have poor outcome to treatment, thus novel therapies such as CAR T cell therapy could represent an alternative in treating AMkL. We investigated the effect of a new CAR T cell which targets CD41, a specific surface antigen for M7-AMkL, against an in vitro model for AMkL, DAMI Luc2 cell line. The performed flow cytometry evaluation highlighted a percentage of 93.8% CAR T cells eGFP-positive and a limited acute effect on lowering the target cell population. However, the interaction between effector and target (E:T) cells, at a low ratio, lowered the cell membrane integrity, and reduced the M7-AMkL cell population after 24 h of co-culture, while the cytotoxic effect was not significant in groups with higher E:T ratio. Our findings suggest that the anti-CD41 CAR T cells are efficient for a limited time spawn and the cytotoxic effect is visible in all experimental groups with low E:T ratio.     

Effects of Sirolimus treatment on patients with β-Thalassemia: Lymphocyte immunophenotype and biological activity of memory CD4+ and CD8+ T cells

Inhibitors of the mammalian target of rapamycin (mTOR) have been proposed to improve vaccine responses, especially in the elderly. Accordingly, testing mTOR inhibitors (such as Sirolimus) and other geroprotective drugs might be considered a key strategy to improve overall health resilience of aged populations. In this respect, Sirolimus (also known as rapamycin) is of great interest, in consideration of the fact that it is extensively used in routine therapy and in clinical studies for the treatment of several diseases. Recently, Sirolimus has been considered in laboratory and clinical studies aimed to find novel protocols for the therapy of hemoglobinopathies (e.g. β-Thalassemia). The objective of the present study was to analyse the activity of CD4⁺ and CD8⁺ T cells in β-Thalassemia patients treated with Sirolimus, taking advantages from the availability of cellular samples of the NCT03877809 clinical trial. The approach was to verify IFN-γ releases following stimulation of peripheral blood mononuclear cells (PBMCs) to stimulatory CEF and CEFTA peptide pools, stimulatory for CD4⁺ and CD8⁺ T cells, respectively. The main results of the present study are that treatment of β-Thalassemia patients with Sirolimus has a positive impact on the biological activity and number of memory CD4⁺ and CD8⁺ T cells releasing IFN-γ following stimulation with antigenic stimuli present in immunological memory. These data are to our knowledge novel and in our opinion of interest, in consideration of the fact that β-Thalassemia patients are considered prone to immune deficiency.     

Protein phosphorylation in Rhodnius prolixus oocytes: identification of a type II casein kinase

A protein kinase activity in chorionated oocytes of Rhodnius prolixus phosphorylates in vitro vitellin (VT), the major yolk protein. Phosphatase inhibitors including NaF, sodium vanadate, beta-glycerophosphate and okadaic acid did not alter the protein phosphorylation profile to a visible extent. Among the exogenous protein substrates tested, casein was readily phosphorylated, but histones were not. Several different protein kinase activators, including cAMP, Ca2+ plus calmodulin, Ca2+ plus diolein and phosphatidylserine, were added to the reaction media but spermidine was the only effective one, inducing a 2-fold increase in the phosphorylation of VT. A strong inhibition was obtained with nanomolar levels of heparin. The enzyme could also accept GTP as the phosphate donor instead of ATP. These properties identify the major protein kinase activity as a type II casein kinase (CK II). The pH dependence and the effects of mono- and divalent cations on VT phosphorylation were also studied. Gel filtration revealed only one peak of protein kinase activity, with a molecular mass of 170 K, similar to values previously reported in the literature for CK IIs from other organisms.     

Inflorescence-specific genes from Arabidopsis thaliana encoding glycine-rich proteins

Genomic and cDNA clones for three inflorescence-specific genes from Arabidopsis thaliana were isolated and characterized. The genes are tandemly organized in the genome on a 10 kb fragment. The expression of these genes is coordinately regulated in a developmental and organ-specific pattern. They are expressed predominantly in anthers at the later stage of flower development. The primary structure of the encoded gene products exhibits comparable features consisting of a hydrophobic domain at the N-terminal region followed by repeated glycine-rich motifs. Little homology is observed either between the glycine-rich domain of the three genes or with previously described glycine-rich proteins from other plant species.     

Plenty of rooftops with few neighbours occupied by young breeding Yellow-legged Gulls (Larus michahellis): Does this occur at the expense of their health condition?

Gulls, as largely flexible opportunistic individuals, have been increasingly breeding in many cities around the world, but it is still unclear whether urban habitats are of equal or higher quality than traditional natural habitats or represent an ecological trap with immediate reproductive benefits but longer-term detrimental consequences to health. Here we present a study of breeding parameters (nest density, egg dimensions, clutch size, hatching success and adult body condition) and physiological parameters (erythrocyte sedimentation rate, heterophil/lymphocyte ratio, haemoglobin concentration and measurements of oxidative stress) as indicators of the general health condition of Yellow-legged Gull Larus michahellis adults and chicks from natural and urban colonies. Yellow-legged Gulls in the largest urban area (Porto) laid smaller eggs and clutches, showed a significantly lower occurrence of inflammatory processes in chicks, and showed a slower early chick growth than in the natural colony of Deserta. This suggests that urban gulls might be facing important trade-offs between the advantages of breeding in lower density urban colonies, with fewer intraspecific interactions and a lower disease transmission probability, and the disadvantages of having an anthropogenic diet usually lower in nutritional value.     

Neo-tropical felid activity patterns in relation to potential prey and intraguild competitors in the Calakmul Biosphere Reserve,Mexico

Predator behaviors influence, and are influenced by, prey and competitor behaviors. Jaguars (Panthera onca), pumas (Puma concolor), and ocelots (Leopardus pardalis) coexist throughout their geographic range as the three largest predators in a multi-predator community across diverse environments. This study tested for non-random segregation and overlap in the activity patterns of these felids and their shared prey in the southern buffer zone of the Calakmul Biosphere Reserve, in southern Mexico, using camera traps during February to August 2019. We detected little temporal segregation between the nocturnal activities of jaguars, pumas, and ocelots, although pumas were more active closer to dawn. Jaguars had low activity overlap with species likely to be common prey, whereas ocelots had high overlap with their potential prey. Pumas displayed finer-scale similarities in activity with species likely to be common prey. In an understudied area of conservation importance, this study shows that temporal segregation is an unlikely mechanism of coexistence. Further research should incorporate spatio-temporal avoidance and dietary differences to improve our understanding of the mechanisms that drive coexistence between generalist species in a diverse assemblage of threatened felids. Abstract in Spanish is available with online material.