A simple and robust method to study after-pulses in Silicon Photomultipliers

The after-pulsing probability in Silicon Photomulti- pliers and its time constant are obtained measuring the mean number of photo-electrons in a variable time window following a light pulse. The method, experimentally simple and statistically robust due to the use of the Central Limit Theorem, has been applied to an HAMAMATSU MPPC S10362-11-100C

Modeling Tumor Angiogenesis in Zebrafish

none1noneMassimo M. SantoroSantoro, Massim

ROS homeostasis and metabolism: a dangerous liason in cancer cells

Tumor cells harbor genetic alterations that promote a continuous and elevated production of reactive oxygen species. Whereas such oxidative stress conditions would be harmful to normal cells, they facilitate tumor growth in multiple ways by causing DNA damage and genomic instability, and ultimately, by reprogramming cancer cell metabolism. This review outlines the metabolic-dependent mechanisms that tumors engage in when faced with oxidative stress conditions that are critical for cancer progression by producing redox cofactors. In particular, we describe how the mitochondria has a key role in regulating the interplay between redox homeostasis and metabolism within tumor cells. Last, we will discuss the potential therapeutic use of agents that directly or indirectly block metabolism

New models to study vascular mural cell embryonic origin: implications in vascular diseases.

A key question in vascular biology is how the diversity of origin of vascular mural cells, namely smooth muscle cells (SMCs) and pericytes influences vessel properties, in particular the regional propensity to vascular diseases. This review therefore first describes the role and regulation of mural cells during vascular formation, with a focus on embryonic origin. We then consider the evidence that connects heterogeneities in SMC and pericyte origins with disease. Since this idea has major implications for understanding and modelling human disease, then there is a pressing need for new model systems to investigate mural cell development and the consequences of heterogeneity. Recent advances arising from in vitro strategies for deriving mural cells from human pluripotent stem cells as well as from the zebrafish model will be discussed and the medical relevance of these discoveries will be highlighted

6. Reading Wittgenstein Between the Texts

Sharing the “historicist challenge to analytic philosophy” (Glock) we investigate the philosophical production (and, to a lesser extent, some non-philosophical works as well) on Ludwig Wittgenstein from a distant reading perspective. First, we provide a description of the “Wittgensteinian field” by analyzing several data provided by the Philosopher’s Index, an electronic bibliographic database especially devoted to philosophy. Then we analyze these data by using statistical tools (such as for example topic modeling) and we interpret the results historically and sociologically, along the lines of Bourdieu on Heidegger, Lamont on Derrida, Gross on Rorty, and Collins on the whole philosophical tradition

RET: A Multi-Faceted Gene in Human Cancer

Receptor tyrosine kinases (RTK) are transmembrane (TM) proteins featuring an intracellular domain containing the tyrosine kinase (TK) enzyme. RTKs are often involved in cancer formation [13]. Notable examples are epidermal growth factor receptor (EGFR/ HER1) and anaplastic lymphoma kinase (ALK) in non-small cell lung carcinoma (NSCLC) [4], KIT in gastrointestinal stromal tumors (GIST) [5], FLT3 in acute myeloid leukemia (AML) [6], and HER2/ ERBB2/neu in breast cancer [7]. In some cases, cancer cells up-regulate expression of the RTK (as an example HER2 in breast cancer), its cognate growth factor or both, in other cases, structural alterations such as chromosomal rearrangements leading to the RTK recombination to heterologous genes (as an example EML4-ALK in lung adenocarcinoma) or point mutations (as EGFR, KIT or FLT3 mutations in NSCLC, GIST, or AML, respectively), lead to unchecked kinase and oncogenic activity [1-3]. This notion has stimulated the search for agents, such as monoclonal antibodies against the RTK extracellular domain (like trastuzumab for HER2 or cetuximab for EGFR) or ATP-competitive small molecule protein kinase inhibitors (PKIs) (like gefitinib and erlotinib for EGFR or crizotinib for ALK), to combat cancers driven by oncogenic RTKs [1-3]. The RET RTK was originally identified as an oncogene activated by a rearrangement occurred in vitro during transfection of NIH3T3 cells with human lymphoma DNA [8]. RET protein belongs to a cell-surface complex able to bind glial-derived neurotrophic factor (GDNF) ligands (GDNF, neurturin, artemin, and persephin) in conjunction with co-receptors of the GDNF receptor α family, designated GFRα 1-4 [9]. Binding to the ligand-co-receptor complex leads to RET dimerization and kinase activation. RET expression is tightly regulated during development and in the adulthood is limited to specific tissues, including neural crest-derived cells. RET is essential for the development of the enteric neurvous system and kidney, and germline loss-of-function mutations in RET cause Hirschsprung disease (aganglionic megacolon) and congenital anomalies of the kidney or lower urinary tract [10,11]. RET gene maps to chromosome 10q11.2. Fig. 1 shows that it is splitted in 21 coding exons. Exons 1-10 code for the extracellular region; exon 11 codes for the COOH-terminal part of the extracellular region, the TM domain, and the intracellular juxtamembrane domain. Finally, exons 12-21 code for the intracellular domain. An alternative splicing at exon 19 determine the synthesis of three RET protein isoforms with different C-terminal tails. In RET9 (1072 aa), exon 19 is unspliced; in RET51 (1114 aa), exon 19 is spliced to exon 20; in RET43 (1106 aa), exon 19 is spliced to to exon 21 [12-15]. RET9 and RET51 are the most abundant and well characterized isoforms (Fig. 1). RET protein features an extracellular portion (RET-EC) tha

Differential diagnosis of thyroid nodules using fine-needle aspiration cytology and oncogene mutation screening: are we ready?

Thyroid nodules are a very common clinical finding, and although the majority of them are benign, thyroid carcinoma accounts for about 5-15% of nodules. Fine-needle aspiration cytology (FNAC) is actually used for the differential diagnosis of these lesions. Although in most cases this examination clearly distinguishes benign from malignant lesions, some fine-needle aspiration (FNA) samples fall into undetermined thyroid cytology categories, which according to the most recent classification of thyroid FNAC consist of ‘suspicious for malignancy’, ‘suspicious for follicular or Hurtle cell neoplasm’, and ‘follicular lesion of undetermined significance/atypia of undetermined significance’. Moreover, some samples are insufficient for diagnosis. Taken together, these categories account for almost 20-30% of nodules. Owing to the high risk of papillary thyroid carcinoma, patients with lesions that are ‘suspicious for malignancy’ are currently subjected to lobectomy or total thyroidectomy. On the other hand, patients with ‘atypia of undetermined significance’ undergo repeated FNAs, and patients with ‘suspicious for follicular or Hurtle cell neoplasm’ are subjected to diagnostic lobectomy and subsequently, in the case of histological diagnosis of carcinoma, total thyroidectomy. Recent studies clearly indicate that molecular analysis of thyroid nodules can significantly improve the diagnostic power of cytology and drive the appropriate clinical management of these patients

Cilia Control Vascular Mural Cell Recruitment in Vertebrates

Vascular mural cells (vMCs) are essential components of the vertebrate vascular system, controlling blood vessel maturation and homeostasis. Discrete molecular mechanisms have been associated with vMC development and differentiation. The function of hemodynamic forces in controlling vMC recruitment is unclear. Using transgenic lines marking developing vMCs in zebrafish embryos, we find that vMCs are recruited by arterial-fated vessels and that the process is flow dependent. We take advantage of tissue-specific CRISPR gene targeting to demonstrate that hemodynamic-dependent Notch activation and the ensuing arterial genetic program is driven by endothelial primary cilia. We also identify zebrafish foxc1b as a cilia-dependent Notch-specific target that is required within endothelial cells to drive vMC recruitment. In summary, we have identified a hemodynamic-dependent mechanism in the developing vasculature that controls vMC recruitment