Scale-factor duality in string Bianchi cosmologies

We apply the scale factor duality transformations introduced in the context of the effective string theory to the anisotropic Bianchi-type models. We find dual models for all the Bianchi-types [except for types $VIII$ and $IX$] and construct for each of them its explicit form starting from the exact original solution of the field equations. It is emphasized that the dual Bianchi class $B$ models require the loss of the initial homogeneity symmetry of the dilatonic scalar field.Comment: 18 pages, no figure

Drosophila CG3303 is an essential endoribonuclease linked to TDP-43-mediated neurodegeneration

Endoribonucleases participate in almost every step of eukaryotic RNA metabolism, acting either as degradative or biosynthetic enzymes. We previously identified the founding member of the Eukaryotic EndoU ribonuclease family, whose components display unique biochemical features and are flexibly involved in important biological processes, such as ribosome biogenesis, tumorigenesis and viral replication. Here we report the discovery of the CG3303 gene product, which we named DendoU, as a novel family member in Drosophila. Functional characterisation revealed that DendoU is essential for Drosophila viability and nervous system activity. Pan-neuronal silencing of dendoU resulted in fly immature phenotypes, highly reduced lifespan and dramatic motor performance defects. Neuron-subtype selective silencing showed that DendoU is particularly important in cholinergic circuits. At the molecular level, we unveiled that DendoU is a positive regulator of the neurodegeneration-associated protein dTDP-43, whose downregulation recapitulates the ensemble of dendoU-dependent phenotypes. This interdisciplinary work, which comprehends in silico, in vitro and in vivo studies, unveils a relevant role for DendoU in Drosophila nervous system physio-pathology and highlights that DendoU-mediated neurotoxicity is, at least in part, contributed by dTDP-43 loss-of-function

Mir-34a-5p Mediates Cross-Talk between M2 Muscarinic Receptors and Notch-1/EGFR Pathways in U87MG Glioblastoma Cells: Implication in Cell Proliferation

Glioblastoma (GBM) is the most aggressive human brain tumor. The high growth potential and decreased susceptibility to apoptosis of the glioma cells is mainly dependent on genetic amplifications or mutations of oncogenic or pro-apoptotic genes, respectively. We have previously shown that the activation of the M2 acetylcholine muscarinic receptors inhibited cell proliferation and induced apoptosis in two GBM cell lines and cancer stem cells. The aim of this study was to delve into the molecular mechanisms underlying the M2-mediated cell proliferation arrest. Exploiting U87MG and U251MG cell lines as model systems, we evaluated the ability of M2 receptors to interfere with Notch-1 and EGFR pathways, whose activation promotes GBM proliferation. We demonstrated that the activation of M2 receptors, by agonist treatment, counteracted Notch and EGFR signaling, through different regulatory cascades depending, at least in part, on p53 status. Only in U87MG cells, which mimic p53-wild type GBMs, did M2 activation trigger a molecular circuitry involving p53, Notch-1, and the tumor suppressor mir-34a-5p. This regulatory module negatively controls Notch-1, which affects cell proliferation mainly through the Notch-1/EGFR axis. Our data highlighted, for the first time, a molecular circuitry that is deregulated in the p53 wild type GBM, based on the cross-talk between M2 receptor and the Notch-1/EGFR pathways, mediated by mir-34a-5p

Global Emergence of Colistin-Resistant Escherichia coli in Food Chains and Associated Food Safety Implications: A Review

Antimicrobial resistance in bacteria represents one of the most important challenges for public health worldwide. Human infections from antimicrobial-resistant bacteria can be transmitted from person to person, via the environment (especially in the hospital environment), or via handling or eating contaminated foods. Colistin is well known as a last-resort antibiotic for the treatment of human infections; a recent study performed in the People's Republic of China has revealed that colistin resistance is also conferred by the plasmid-mediated mcr-1 gene in Escherichia coli. After that discovery, further plasmid-mediated, colistin resistance genes have been detected. However, to date, only reports on E. coli carrying the mcr-1 gene (E. coli mcr-1+) in foodstuff are available. E. coli mcr-1+ has been isolated from food of animal origin and vegetables; this discovery has opened a debate among food safety experts. This review aims to provide a critical overview of the currently available scientific literature on the presence of the plasmid-mediated, colistin resistance gene E. coli mcr-1 in foodstuffs, focusing on the main implications and future perspectives for food safety

Micro-Raman Spectroscopy of Dental Implants Subjected to Different Surface Treatments

The aim of the study was to qualitatively investigate the structure of the surface layer of TiO2 on dental implants made of Ti-6Al-4V subjected to different manufacturing treatments. M (machined), B (Al2O3-blasted), E (HNO3HF-etched), B + E and A (B + E + anodized) implants and a further group receiving the same treatments as the first group with the addition of a final decontamination with cold plasma were included in the study. Examination was performed using micro-Raman spectroscopy. The surface treatments evaluated did not achieve the formation of crystalline TiO2. The increase in the complexity of surface treatment produced a proportional increase in the thickness of amorphous TiO2 oxide. In the B + E group, the plasma treatment enhanced the amorphous oxide thickness of TiO2. The other surfaces treated by plasma decontamination did not show a difference to the respective untreated ones. The investigated surface treatments did not change the crystalline cage of TiO2 in Ti-6Al-4V implants but affected the thickness of the oxide layer. The biological response could be influenced by different oxide thicknesses. Additional information on superficial TiO2 structural organization can be obtained by micro-Raman evaluation of dental implants. Dental implants with B + E + plasma and A superficial treatments allowed the maximum formation of the amorphous oxide thickness

The long noncoding RNA linc-NeD125 controls the expression of medulloblastoma driver genes by microRNA sponge activity

Long noncoding RNAs (lncRNAs) are major regulators of physiological and disease-related gene expression, particularly in the central nervous system. Dysregulated lncRNA expression has been documented in several human cancers, and their tissue-specificity makes them attractive candidates as diagnostic/prognostic biomarkers and/or therapeutic agents. Here we show that linc-NeD125, which we previously characterized as a neuronal-induced lncRNA, is significantly overexpressed in Group 4 medulloblastomas (G4 MBs), the largest and least well characterized molecular MB subgroup. Mechanistically, linc-NeD125 is able to recruit the miRNA-induced silencing complex (miRISC) and to directly bind the microRNAs miR-19a-3p, miR-19b-3p and miR-106a-5p. Functionally, linc-NeD125 acts as a competing endogenous RNA (ceRNA) that, sequestering the three miRNAs, leads to de-repression of their targets CDK6, MYCN, SNCAIP, and KDM6A, which are major driver genes of G4 MB. Accordingly, linc-NeD125 downregulation reduces G4 cell proliferation. Moreover, we also provide evidence that linc-NeD125 ectopic expression in the aggressive Group 3 MB cells attenuates their proliferation, migration and invasion. This study unveils the first lncRNA-based ceRNA network in central nervous system tumours and provides a novel molecular circuit underlying the enigmatic Group 4 medulloblastoma

φBO1E, a newly discovered lytic bacteriophage targeting carbapenemase-producing Klebsiella pneumoniae of the pandemic Clonal Group 258 clade II lineage

The pandemic dissemination of KPC carbapenemase-producing Klebsiella pneumoniae (KPC-KP) represents a major public health problem, given their extensive multidrug resistance profiles and primary role in causing healthcare-Associated infections. This phenomenon has largely been contributed by strains of Clonal Group (CG) 258, mostly of clade II, which in some areas represent the majority of KPC-KP isolates. Here we have characterized a newly discovered lytic Podoviridae, named φBO1E, targeting KPC-KP strains of clade II lineage of CG258. Genomic sequencing revealed that φBO1E belongs to the Kp34virus genus (87% nucleotide identity to vB-KpnP-SU552A). ΦBO1E was stable over a broad pH and temperature range, exhibited strict specificity for K. pneumoniae strains of clade II of CG258, and was unable to establish lysogeny. In a Galleria mellonella infection model, φBO1E was able to protect larvae from death following infection with KPC-KP strains of clade II of CG258, including one colistin resistant strain characterized by a hypermucoviscous phenotype. To our best knowledge φBO1E is the first characterized lytic phage targeting K. pneumoniae strains of this pandemic clonal lineage. As such, it could be of potential interest to develop new agents for treatment of KPC-KP infections and for decolonization of subjects chronically colonized by these resistant superbugs

The risk of late or advanced presentation of HIV infected patients is still high, associated factors evolve but impact on overall mortality is vanishing over calendar years: Results from the Italian MASTER Cohort

BACKGROUND: We aimed at evaluating frequency and factors associated with late presentation and advanced HIV disease and excess risk of death due to these conditions from 1985 to 2013 among naïve HIV infected patients enrolled in the Italian MASTER Cohort. METHODS: All antiretroviral naive adults with available CD4+ T cell count after diagnosis of HIV infection were included. Multivariable logistic regression analysis investigated factors associated either with late presentation or advanced HIV disease. Probabilities of survival were estimated both at year-1 and at year-5 according to the Kaplan-Meier method. Flexible parametric models were used to evaluate changes in risk of death overtime according to late presentation and advanced HIV disease. The analyses were stratified for calendar periods. RESULTS: 19,391 patients were included (54 % were late presenters and 37.6 % were advanced presenters). At multivariable analysis, the following factors were positively associated with late presentation: male gender (OR = 1.29), older age (≥55 years vs. <25 years; OR = 7.45), migration (OR = 1.54), and heterosexual risk factor for HIV acquisition (OR = 1.52) or IDU (OR = 1.27) compared to homosexual risk. Survival rates at year-5 increased steadily and reached 92.1 % for late presenters vs. 97.4 % for non-late presenters enrolled in the period 2004-2009. Using flexible parametric models we found a sustained reduction of hazard ratios over time for any cause deaths between late and non-late presenters over time. Similar results were found for advanced HIV disease. CONCLUSION: Screening polices need to be urgently implemented, particularly in most-at-risk categories for late presentation, such as migrants, older patients and those with heterosexual intercourse or IDU as risk factors for HIV acquisition. Although in recent years the impact of late presentation on survival decreased, about 10 % of patients diagnosed in more recent years remains at increased risk of death over a long-term follow-up