In order to better de¢ne the structural elements involved in allosteric signalling, wild-type DnaK and three deletion mutants of the peptide binding domain have been characterized by biophysical (steady-state and time-resolved £uorescence) and biochemical methods. In the presence of ATP the chemical environment of the single tryptophan residue of DnaK, located in the ATPase domain, becomes less polar, as seen by a blue shift of the emission maximum and a shortening of the £uorescence lifetime, and its accessibility to polar quenchers is drastically reduced. These nucleotide-dependent modi¢cations are also observed for the deletion mutant DnaK1-537, but not for DnaK1-507 or DnaK1-385, and thus rely on the presence of residues 507^537 (helices A and the N-terminal half of B) of the peptide binding domain. These data indicate that K KA and half K KB contribute to the allosteric communication of DnaK. In the presence of ATP, they promote a conformational change that displaces a residue(s) of the peptide binding domain towards a region of the ATPase domain where the tryptophan residue (W102) is located. A putative role for these helical segments as regulators of the position of the lid is discussed. ß

In spite of development of molecular therapeutics, multiple myeloma (MM) is fatal in most cases. CD38 is a promising target for selective treatment of MM. We tested radioimmunoconjugates consisting of the α-emitter 213Bi coupled to an anti-CD38 MAb in preclinical treatment of MM. Efficacy of 213Bi-anti-CD38-MAb was assayed towards different MM cell lines with regard to induction of DNA double-strand breaks, induction of apoptosis and initiation of cell cycle arrest. Moreover, mice bearing luciferase-expressing MM xenografts were treated with 213Bi-anti-CD38-MAb. Therapeutic efficacy was monitored by bioluminescence imaging, overall survival and histology. 213Bi-anti-CD38-MAb treatment induced DNA damage which did not result in activation of the G2 DNA-damage-response checkpoint, but instead in mitotic arrest and subsequent mitotic catastrophe. The anti-tumor effect of 213Bi-anti-CD38-MAb correlated with the expression level of CD38 in each MM cell line. In myeloma xenografts, treatment with 213Bi-anti-CD38-MAb suppressed tumor growth via induction of apoptosis in tumor tissue and significantly prolonged survival compared to controls. The major organ systems did not show any signs of 213Bi-induced toxicity. Preclinical treatment of MM with 213Bi-anti-CD38-MAb turned out as an effective therapeutic option.

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Soil contamination by heavy metals, particularly mercury (Hg), is a problem that can seriously affect the environment, animals, and human health. Hg has the capacity to biomagnify in the food chain. That fact can lead to pathologies, of those which affect the central nervous system being the most severe. It is convenient to know the biological environmental indicators that alert of the effects of Hg contamination as well as the biological mechanisms that can help in its remediation. To contribute to this knowledge, this study conducted comparative analysis by the use of Shotgun metagenomics of the microbial communities in rhizospheric soils and bulk soil of the mining region of Almadén (Ciudad Real, Spain), one of the most affected areas by Hg in the world The sequences obtained was analyzed with MetaPhlAn2 tool and SUPER-FOCUS. The most abundant taxa in the taxonomic analysis in bulk soil were those of Actinobateria and Alphaproteobacteria. On the contrary, in the rhizospheric soil microorganisms belonging to the phylum Proteobacteria were abundant, evidencing that roots have a selective effect on the rhizospheric communities. In order to analyze possible indicators of biological contamination, a functional potential analysis was performed. The results point to a co-selection of the mechanisms of resistance to Hg and the mechanisms of resistance to antibiotics or other toxic compounds in environments contaminated by Hg. Likewise, the finding of antibiotic resistance mechanisms typical of the human clinic, such as resistance to beta-lactams and glycopeptics (vancomycin), suggests that these environments can behave as reservoirs. The sequences involved in Hg resistance (operon mer and efflux pumps) have a similar abundance in both soil types. However, the response to abiotic stress (salinity, desiccation, and contaminants) is more prevalent in rhizospheric soil. Finally, sequences involved in nitrogen fixation and metabolism and plant growth promotion (PGP genes) were identified, with higher relative abundances in rhizospheric soils. These findings can be the starting point for the targeted search for microorganisms suitable for further use in bioremediation processes in Hg-contaminated environments.

Fasciolasis is a zoonotic parasitic disease caused by Fasciola hepatica and its control is mainly based on the use of triclabendazole (TCBZ). Parasite resistance to different anthelmintics is growing worldwide, including the resistance of F. hepatica to TCBZ. In the present work we evaluate "in vivo" the activity of xenobiotic metabolizing enzymes of phase I (carboxyl esterases) and phase II (glutathione S-transferases and carbonyl reductases) recovered of flukes from sheep treated with TCBZ. All three enzymes showed increased activity in TCBZ flukes returning 60h post-treatment at similar to baseline unexposed flukes. TCBZ action may induce secondary oxidative stress, which may explain the observed increment in activities of the analyzed enzymes as a defensive mechanism. The enzymes analyzed are candidates to participate actively in the development of resistance at TCBZ in F. hepatica.

Background Multiple myeloma (MM) is a heterogeneous disease that is most frequently diagnosed in the elderly. Therefore, data on clinical characteristics and outcomes in the young population are scarce and it is recognized that it remains incurable even in this group of patients. We present here the outcomes of patients under 40 years old cohort in Latin-American countries. On behalf of GELAMM (Grupo de Estudio Latino-Americano de Mieloma Múltiple). Methods Retrospective international multicenter cohort study. We analyzed MM patients under 40 years old who received treatment in 6 Latin-American countries, between 2010 and 2018. Demographics and disease features were analyzed using descriptive statics. We examined treatment characteristics and response rates. The overall survival (OS) of the entire cohort was analyzed using Kaplan-Meier curves. Results Eighty-six patients of 6 countries were analyzed (Table1). The mean age was 35.4 years old, and 60% were male. The most frequent monoclonal component type was IgG followed by light chain MM. Risk determined by ISS was distributed in almost equal percentages. The most frequent cytogenetic alteration was the t (4;14) that was found in four patients out of 25 evaluated. The missing data were greater than 70%. Skeleton-related events were the most frequent clinical feature, followed by anemia and renal failure. Plasmacytomas and fractures were present in more than 20 percent of cases. With regard to treatment, VCD / CyBorD was the most used regimen, followed by VTD. The overall response rate (ORR) was 63%. Fifty-three patients received high dose therapy and autologous stem cell transplantation (62%). Only 8% received post-transplant consolidation, and 45% received maintenance therapy. The median OS of the entire cohort was 45 months, and a plateau in the survival curve was not observed, suggesting that patients continue relapsing over the time. Conclusion In this Latin American multicenter study, we found that the young population with MM has similar presentation characteristics to those of elderly patients. A significant amount of information is lost regarding the risk characterization, especially in regard with cytogenetics. With respect to treatment, less than half of the patients achieve very good partial response or better. It is striking that more than a third of this young patients did not access to high doses of chemotherapy and bone marrow transplantation. Maintenance therapy is offered to less than half patients. The median OS is lower than in other series of patients younger than 40 years, even than in the elderly cohorts. Prospective multicentric studies are required to elucidate the behavior of the disease in this group of patients. Disclosures Peña: Pfizer: Membership on an entity's Board of Directors or advisory committees; Janssen: Other: Congress inscription and flights; Biotoscana: Other: Congress inscription and flights; Novartis: Other: Congress inscription and flights; Tecnofarma: Other: Congress inscription and flights; Roche: Other: Congress inscription and flights. Rojas:Novartis: Membership on an entity's Board of Directors or advisory committees; Pfeizer: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees. Abello:Takeda: Other: Participation in advisory board meeting. Gomez-Almaguer:Takeda: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Teva: Consultancy, Speakers Bureau.