Biosignatures and Bacterial Diversity in Hydrothermal Deposits of Solfatara Crater,Italy

We have combined mineralogy, organic geochemistry and molecular microbiology to study hydrothermal deposits from Solfatara Crater, a geologically young volcanic formation (～4,000 years old) displaying hot (45–95°C) and acidic (pH 1.7) mud pools and fumaroles. The search for inorganic (mineral) biosignatures revealed the presence of delicate structures, most likely mineralized extracellular polymers (EPSs), and the presence of potential biologically induced minerals: sulfides, sulfates (barite and alunite), elemental sulfur, and iron oxides. Geochemical analyses revealed a low total organic carbon content, 0.13 to 0.53%, displaying δ¹³C values from ?17.09 to ?27.39‰, and total nitrogen contents from 0.03 to 0.12%, which are characteristic of hydrothermal systems and suggest the presence of autotrophic carbon fixation. Lipid biomarker analysis showed the presence of hopanoids and linear alkanes, and the absence of detectable steroids, implying the occurrence of bacteria in our samples. We constructed 16S rRNA gene libraries from the environmental samples. Most environmental sequences obtained were affiliated to the Alpha- and Betaproteobacteria (Hydrogenophilus-like), the Acidobacteria, and to a lesser extent, the Gammaproteobacteria and Actinobacteria. When known, the closest cultivated relatives were often thermophilic or thermotolerant bacteria oxidizing iron, hydrogen, or methane/methanol, suggesting an important microbial contribution to the formation of biominerals.     

Egg predation within the nests of social wasps: a new genus and species of Phlaeothripidae,and evolutionary consequences of Thysanoptera invasive behaviour

The insects known as thrips are commonly thought of as flower‐living and pestiferous organisms, but we report here a novel interaction between a phlaeothripine thrips species, Mirothrips arbiter gen. et sp. nov. and three species of social paper wasps in Brazil. This thrips species breeds inside the wasp colonies, and larval and adult thrips feed on wasp eggs, which become severely damaged. Infested nests can contain up to 300 M. arbiter gen. et sp. nov. individuals. The closest relatives of M. arbiter are two presumably predaceous species: Mirothrips bicolor sp. nov. , which inhabits abandoned Cecidomyiidae galls, and Mirothrips analis comb. nov. , described from individuals collected in the silken bags of the caterpillars of Psychidae moths. The behaviour exhibited by M. arbiter represents one of the most evolutionarily advanced lifestyles known among Thysanoptera, and we predict that other polistine species serve as hosts for this thrips in Brazil. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109 , 332–341.     

Younger and older chronic somatoform pain patients in psycho-diagnostics,physician-patient relationship and treatment outcome

Introduction

Patients with chronic pain are found with highly variable clinical presentation and differing physical complaints. They are seen as a heterogenic group. Based on clinical observations, elderly patients seem to differ from younger patients with chronic pain. We examined whether there were systematic differences between young and old pain patients.

Methods

As part of a routine evaluation of university hospital care, a newly developed psychosomatic treatment model for chronic somatoform pain disorders was examined. The basis for treatment efficacy was a target-oriented, specific somatic and psychological intervention that included a stable physician-patient relationship. Particular attention was paid to differences in treatment outcome with regard to changes in both physical and psychopathological symptom levels. We hypothesised that younger pain patients had higher psychological burden and benefitted more from our treatment than older pain patients.

Results

Overall, 179 inpatients (57.5% women) with chronic pain were examined (age between 16 and 79 years). The group as a whole yielded high scores on the somatisation dimension (SCL-90) and showed a considerable amount of psychopathological symptoms, such as depressive mood and anxiety (HADS) and a great emotional instability (FPI-R). Age differences were only found with regards to patients’ degree of aggression (SCl-90): younger patients showed higher aggressive tendencies than older ones (p< 0.05). The treatment offered helped patients in both age groups especially with regard to reduction of depressive mood (HADS, p< 0.01) and anxiety levels (HADS, p< 0.01). Regression analysis showed different age groups and gender as significant predictors of anxiety reduction under therapy (R²=.108; model: p< 0.01).

Discussion and conclusion

Results show that younger chronic pain patients suffer more from a considerable amount of psychological distress than older ones, but our treatment approach was equally effective in both groups. However, age and gender differences, as well as the patient’s baseline level of anxiety influenced the outcome. These factors need to be studied in future research.

     

A Trypanosoma brucei Kinesin Heavy Chain Promotes Parasite Growth by Triggering Host Arginase Activity

Background

In order to promote infection, the blood-borne parasite Trypanosoma brucei releases factors that upregulate arginase expression and activity in myeloid cells.

Methodology/Principal findings

By screening a cDNA library of T. brucei with an antibody neutralizing the arginase-inducing activity of parasite released factors, we identified a Kinesin Heavy Chain isoform, termed TbKHC1, as responsible for this effect. Following interaction with mouse myeloid cells, natural or recombinant TbKHC1 triggered SIGN-R1 receptor-dependent induction of IL-10 production, resulting in arginase-1 activation concomitant with reduction of nitric oxide (NO) synthase activity. This TbKHC1 activity was IL-4Rα-independent and did not mirror M2 activation of myeloid cells. As compared to wild-type T. brucei, infection by TbKHC1 KO parasites was characterized by strongly reduced parasitaemia and prolonged host survival time. By treating infected mice with ornithine or with NO synthase inhibitor, we observed that during the first wave of parasitaemia the parasite growth-promoting effect of TbKHC1-mediated arginase activation resulted more from increased polyamine production than from reduction of NO synthesis. In late stage infection, TbKHC1-mediated reduction of NO synthesis appeared to contribute to liver damage linked to shortening of host survival time.

Conclusion

A kinesin heavy chain released by T. brucei induces IL-10 and arginase-1 through SIGN-R1 signaling in myeloid cells, which promotes early trypanosome growth and favors parasite settlement in the host. Moreover, in the late stage of infection, the inhibition of NO synthesis by TbKHC1 contributes to liver pathogenicity.     

The nascent polypeptide-associated complex (NAC) controls translation initiation in cis by recruiting nucleolin to the encoding mRNA

Protein aggregates and abnormal proteins are toxic and associated with neurodegenerative diseases. There are several mechanisms to help cells get rid of aggregates but little is known on how cells prevent aggregate-prone proteins from being synthesised. The EBNA1 of the Epstein-Barr virus (EBV) evades the immune system by suppressing its own mRNA translation initiation in order to minimize the production of antigenic peptides for the major histocompatibility (MHC) class I pathway. Here we show that the emerging peptide of the disordered glycine–alanine repeat (GAr) within EBNA1 dislodges the nascent polypeptide-associated complex (NAC) from the ribosome. This results in the recruitment of nucleolin to the GAr-encoding mRNA and suppression of mRNA translation initiation in cis. Suppressing NAC alpha (NACA) expression prevents nucleolin from binding to the GAr mRNA and overcomes GAr-mediated translation inhibition. Taken together, these observations suggest that EBNA1 exploits a nascent protein quality control pathway to regulate its own rate of synthesis that is based on sensing the nascent GAr peptide by NAC followed by the recruitment of nucleolin to the GAr-encoding RNA sequence.