Cantharidin content in two Mediterranean species of blister beetles,Lydus trimaculatus and Mylabris variabilis (Coleoptera: Meloidae)

Cantharidin (CA), a toxic terpene produced by blister beetles (Coleoptera: Meloidae), attracts the interest of many researchers for its renowned medical properties. The CA content in blister beetles has been mainly quantified in some Oriental species, due to their use in traditional Chinese medicine, or in few other species of toxicological importance. As CA quantification has been largely ignored in many other members of this family, we aimed at estimating CA content in natural populations of two of the most abundant species in central Italy, Mylabris variabilis and Lydus trimaculatus. Nearly 100 individuals for each species were collected in the field, identified and reared in fauna‐boxes until CA collection. Available protocols were optimized for CA extraction from both dried‐body tissues and exuded hemolymph collected from leg joints using capillary tubes. The CA content was quantified in a gas chromatography system coupled to a mass spectrometer using a calibration curve with diethyl‐ester of norcantharidin as the internal standard. We observed: (i) high variability in CA content among specimens, which was positively related to individual dry‐weight; and (ii) slightly larger (though non‐significant) amount of CA in males than in females for both species. Our data are consistent with the available published reports about CA content, transfer and distribution in blister beetles and suggest a conserved biological role of this terpene in Meloidae.     

Early introductions and transmission of SARS-CoV-2 variant B.1.1.7 in the United States

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Climate warming induced a stretch of the breeding season and an increase of second clutches in a passerine breeding at its altitudinal limits

The increase in the average air temperature due to global warming has produced an early onset of the reproduction in many migratory birds of the Paleartic region. According to the “mismatch hypothesis” this response can lead to a decrease in the breeding output when the conditions that trigger the departure from the wintering areas do not match the availability of food resources in the breeding ground. We used 653 brooding events registered during the period 1991–2013 to investigate the link between climatic variables and individual breeding performance of a partially migratory passerine, the Rock Sparrow Petronia petronia, breeding at the altitude limit of its distribution. The laying date (LD) of the earliest first clutch was associated with local spring (minimum) temperatures but did not show a significant trend during the period considered. The LD of the latest first clutch had a positive and statistically significant trend, unrelated to local covariates and resulting in a longer breeding season (∼1.5 days/year). A longer breeding season allowed birds to produce more second clutches, which proportion increased from 0.14 to 0.25. The average breeding success was also positively correlated with the average temperature in July and with the duration of the breeding season. Contrary to expectations, the most important climate-dependent effect was a stretch of the breeding season due to a significant increase of the LD of the latest first-clutches rather than an earlier breeding onset. We show how climate changes act on bird populations through multiple paths and stress the need to assess the link between climatic variables and several aspects of the breeding cycle.     

Higher frequency of T-cell response to M. tuberculosis latency antigen Rv2628 at the site of active tuberculosis disease than in peripheral blood

Rationale

Due to the invasive nature of the procedures involved, most studies of Mycobacterium tuberculosis (Mtb)-specific immunity in humans have focused on the periphery rather than the site of active infection, the lung. Recently, antigens associated with Mtb-latency and -dormancy have been described using peripheral blood (PB) cells; however their response in the lung is unknown. The objective of this report was to evaluate, in patients prospectively enrolled with suspected active tuberculosis (TB), whether the latency antigen Rv2628 induces local-specific immune response in bronchoalveolar lavage (BAL) cells compared to PB cells.

Material/Methods

Among the 41 subjects enrolled, 20 resulted with active TB. Among the 21 without active disease, 9 were defined as subjects with latent TB-infection (LTBI) [Quantiferon TB Gold In-tube positive]. Cytokine responses to Rv2628 were evaluated by enzyme linked immunospot (ELISPOT) assay and flow cytometric (FACS) analysis. RD1-secreted antigen stimulation was used as control.

Results

There was a significantly higher frequency of Rv2628- and RD1-specific CD4⁺ T-cells in the BAL of active TB patients than in PB. However the trend of the response to Rv2628 in subjects with LTBI was higher than in active TB in both PB and BAL, although this difference was not significant. In active TB, Rv2628 and RD1 induced a cytokine-response profile mainly consisting of interferon (IFN)-γ-single-positive over double-IFN-γ/interleukin (IL)-2 T-cells in both PB and BAL. Finally, BAL-specific CD4⁺ T-cells were mostly effector memory (EM), while peripheral T-cell phenotypes were distributed among naïve, central memory and terminally differentiated effector memory T-cells.

Conclusions

In this observational study, we show that there is a high frequency of specific T-cells for Mtb-latency and RD1-secreted antigens (mostly IFN-γ-single-positive specific T-cells with an EM phenotype) in the BAL of active TB patients. These data may be important for better understanding the pathogenesis of TB in the lung.     

Trophic relationships among scorpaeniform fishes associated with gas platforms

Trophic relationships between Scorpaena porcus, S. notata and Chelidonichthys lucerna collected near natural gas platforms were investigated for the first time in central Adriatic Sea from July 2005 to May 2006. Sampling was repeated at control sites on soft bottom where, however, only C. lucerna occurred. All of the three predators showed diet specialization for crustaceans, with high overlap for angular crab Goneplax rhomboides. The widest prey variety, consisting mainly of epibenthic and infaunal organisms, was detected in C. lucerna, whose feeding behaviour resulted not to be affected by the presence of platforms. Burrowing shrimp Alpheus glaber, hairy crab Pilumnus hirtellus, bivalve Corbula gibba, and European anchovy Engraulis encrasicolus discriminated S. porcus diet, while thalassinid Jaxea nocturna discriminated S. notata diet. The occurrence of E. encrasicolus as natural prey of S. porcus is discussed. Overall, predators like scorpaenids, which live in strict association with platforms in the study area, seem to rely on soft bottom prey items rather than exploiting resources from the platforms, thus competing with soft-bottom predators (i.e. triglids) for the same resources.