44 research outputs found

    Oxidation States, Thouless' Pumps, and Nontrivial Ionic Transport in Nonstoichiometric Electrolytes

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    Thouless' quantization of adiabatic particle transport permits one to associate an integer topological charge with each atom of an electronically gapped material. If these charges are additive and independent of atomic positions, they provide a rigorous definition of atomic oxidation states and atoms can be identified as integer-charge carriers in ionic conductors. Whenever these conditions are met, charge transport is necessarily convective; i.e., it cannot occur without substantial ionic flow, a transport regime that we dub trivial. We show that the topological requirements that allow these conditions to be broken are the same that would determine a Thouless' pump mechanism if the system were subject to a suitably defined time-periodic Hamiltonian. The occurrence of these requirements determines a nontrivial transport regime whereby charge can flow without any ionic convection, even in electronic insulators. These results are first demonstrated with a couple of simple molecular models that display a quantum-pump mechanism upon introduction of a fictitious time dependence of the atomic positions along a closed loop in configuration space. We finally examine the impact of our findings on the transport properties of nonstoichiometric alkali-halide melts, where the same topological conditions that would induce a quantum-pump mechanism along certain closed loops in configuration space also determine a nontrivial transport regime such that most of the total charge current results to be uncorrelated from the ionic ones

    Longitudinal transcriptomic and genetic landscape of radiotherapy response in canine melanoma

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    Canine malignant melanoma (MM) is a highly aggressive tumour with a low survival rate and represents an ideal spontaneous model for the human counterpart. Considerable progress has been recently obtained, but the therapeutic success for canine melanoma is still challenging. Little is known about the mechanisms beyond pathogenesis and melanoma development, and the molecular response to radiotherapy has never been explored before. A faster and deeper understanding of cancer mutational processes and developing mechanisms are now possible through next generation sequencing technologies. In this study, we matched whole exome and transcriptome sequencing in four dogs affected by MM at diagnosis and at disease progression to identify possible genetic mechanisms associated with therapy failure. According to previous studies, a genetic similarity between canine MM and its human counterpart was observed. Several somatic mutations were functionally related to MAPK, PI3K/AKT and p53 signalling pathways, but located in genes other than BRAF, RAS and KIT. At disease progression, several mutations were related to therapy effects. Natural killer cell-mediated cytotoxicity and several immune-system-related pathways resulted activated opening a new scenario on the microenvironment in this tumour. In conclusion, this study suggests a potential role of the immune system associated to radiotherapy in canine melanoma, but a larger sample size associated with functional studies are needed

    Application of an artificial intelligence algorithm to prognostically stratify grade II gliomas

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    (1) Background: Recently, it has been shown that the extent of resection (EOR) and molecular classification of low-grade gliomas (LGGs) are endowed with prognostic significance. However, a prognostic stratification of patients able to give specific weight to the single parameters able to predict prognosis is still missing. Here, we adopt classic statistics and an artificial intelligence algorithm to define a multiparametric prognostic stratification of grade II glioma patients. (2) Methods: 241 adults who underwent surgery for a supratentorial LGG were included. Clinical, neuroradiological, surgical, histopathological and molecular data were assessed for their ability to predict overall survival (OS), progression-free survival (PFS), and malignant progression-free survival (MPFS). Finally, a decision-tree algorithm was employed to stratify patients. (3) Results: Classic statistics confirmed EOR, pre-operative-and post-operative tumor volumes, Ki67, and the molecular classification as independent predictors of OS, PFS, and MPFS. The decision tree approach provided an algorithm capable of identifying prognostic factors and defining both the cut-off levels and the hierarchy to be used in order to delineate specific prognostic classes with high positive predictive value. Key results were the superior role of EOR on that of molecular class, the importance of second surgery, and the role of different prognostic factors within the three molecular classes. (4) Conclusions: This study proposes a stratification of LGG patients based on the different combinations of clinical, molecular, and imaging data, adopting a supervised non-parametric learning method. If validated in independent case studies, the clinical utility of this innovative stratification approach might be proved

    A rare case of undifferentiated nonkeratinizing carcinoma of the lip mucosa.

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    Undifferentiated nonkeratinizing carcinoma (UNC) is a poorly differentiated squamous cell carcinoma accompanied by a prominent reactive lymphoplasmacytic infiltrate that can occur in many anatomic sites. It shares morphologic features with undifferentiated nonkeratinizing nasopharyngeal carcinoma, in which a strong association with Epstein-Barr virus (EBV) has been noted. Among UNCs arising outside the nasopharynx, the linkage with EBV is variable; in particular, the few cases of UNC of the lip described thus far have been negative for EBV. This report describes a rare case of primary UNC of the lower lip mucosa in a 73-year-old man in whom molecular analysis for EBV showed some amount of viral DNA within the tumor. Surgical excision without adjuvant treatment was performed and the patient was alive without recurrence after 42 months of follow-up. This report presents a rare localization of UNC possibly related to EBV infection and with a good clinical outcome

    TTF-1 Positivity in 2 Cases of Adenocarcinoma of the Gastrointestinal Tract.

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    Primary adenocarcinomas of the gastrointestinal tract showing a diffuse thyroid transcription factor-1 (TTF-1)-positive immunostaining are extremely uncommon and this finding in the biopsy specimen could yield to misleading diagnosis of a metastatic lung tumor. We report the clinical and pathological features of 2 cases, occurring in a 62-year-old woman and in a 66-year-old man. The first one is a gastric adenocarcinoma with liver metastasis; the other one is a gallbladder adenocarcinoma discovered during the screening for the colorectal cancer. Both the neoplasms showed a diffuse TTF-1 positivity and both the patients did not have any evidence of lung cancer. Neither a gastric adenocrcinoma with diffuse TTF-1 expression nor a TTF-1-positive gallbladder adenocarcinoma has been described befor

    Hormone receptor and human epidermal growth factor receptor 2 staus evaluation on Thinprep specimens from breast carcinoma: correlation with histologic section detremination

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    BACKGROUND: Fine-needle aspiration cytology (FNAC) is a well-accepted procedure for the diagnosis and biological characterization of breast carcinoma. Estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) status have a strong prognostic and predictive value in invasive breast carcinoma (IBC). ThinPrep (TP) cytology, which uses an alcohol-based fixative, is increasingly being used for immunocytochemistry. In this study, the authors compared the immunocytochemical evaluation of hormone receptors (HR) and HER2 on TP-processed FNAC with the immunohistochemical analysis performed on the corresponding formalin-fixed paraffin-embedded (FFPE) breast tumor specimens, which are considered the gold standard. METHODS: FNACs were performed on 116 primary IBCs at the time of diagnosis and subjected to immunocytochemical evaluation of HR and HER2 using the TP method. The same markers were immunohistochemical evaluated on the corresponding FFPE tissue specimens. HER2 fluorescent in situ hybridization analysis was performed only on the equivocal immunohistochemical results. RESULTS: The HR results of the TP cytology specimens showed a very good agreement with those of the corresponding FFPE tissue samples (Cohen kappa test = 0.92; concordance rate = 98%) for estrogen receptor, and a good agreement (kappa = 0.76; concordance rate = 90.9%) for progesterone receptor. A perfect agreement (kappa = 1) was observed between TP and FFPE tissue samples in evaluating HER2 status. CONCLUSIONS: Alcohol-based fixation seems not to affect the immunocytochemical evaluation of HR and HER2. Considering the high levels of agreement between the evaluation of HR and HER2, on both cytology specimens and on the corresponding FFPE tissue samples, the authors concluded that the TP technique can be routinely used for the biological characterization of IBC. Cancer (Cancer Cytopathol) 2012;

    Childhood encephalomyopathy with cytochrome c oxidase deficiency, ataxia, muscle wasting, and mental impairment

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    The son of third cousins was normal until age 2 when he had difficulty walking. At age 8 there was limb weakness, ataxia, loss of tendon reflexes, dislalia, and he was mildly retarded. During fasting, urinary organic acid excretion was abnormally high. Cytochrome c oxidase activity in muscle was 7% of the normal mean. The enzyme in platelets was 16% of controls with a decreased cytochrome aa3 peak. These data suggest an autosomal recessive transmission of this variant of cytochrome c oxidase deficiency. \ua9 1986 American Academy of Neurology

    Methylome-wide analysis of milk somatic cells upon subclinical mastitis in dairy cattle

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    : Better understanding of the molecular mechanisms behind bovine mastitis is fundamental for improving the management of this disease, which continues to be of major concern for the dairy industry, especially in its subclinical form. Disease severity and progression depend on numerous aspects, such as livestock genetics, and the interaction between the causative agent, the host, and the environment. In this context, epigenetic mechanisms have proven to have a role in controlling the response of the animal to inflammation. Therefore, in this study we aimed to explore genome wide DNA methylation of milk somatic cells (SC) in healthy cows (n = 15) and cows affected by naturally occurring subclinical mastitis by Streptococcus (Strep.) agalactiae (n = 12) and Prototheca spp. (n = 11), to better understand the role of somatic cells methylome in the host response to disease. Differentially methylated regions (DMR) were evaluated comparing: i) Strep. agalactiae-infected vs. healthy; ii) Prototheca-infected vs. healthy, and iii) mastitis vs. healthy and iv) Strep. agalactiae-infected vs. Prototheca-infected. The functional analysis was performed at 2 levels. To begin with, we extracted differentially methylated genes (DMG) from promoter - DMR, which were analyzed using the Cytoscape ClueGO plug-in. Coupled with this DMG-driven approach, all the genes associated with promoter - methylated regions were fed to the Pathifier algorithm. From the DMR analysis, we identified 1,081 hypermethylated and 361 hypomethylated promoter regions in Strep. agalactiae infected animals, while 1,514 hypermethylated and 358 hypomethylated promoter regions were identified in Prototheca infected animals, when compared with the healthy controls. When considering infected animals as a whole group (regardless of the pathogen), we found 1,576 hypermethylated and 460 hypomethylated promoter regions. Both pathogens were associated with methylation differences in genes involved in pathways related to meiosis, reproduction and tissue remodeling. Exploring the whole methylome, in subclinically infected cows we observed a strong deregulation of immune related pathways, such as nuclear factor kB and toll-like receptors signaling pathways, and of energy-related pathways such as the tricarboxylic acid cycle and unsaturated fatty acid biosynthesis. In conclusion, no evident pathogen-specific SC methylome signature was detected in the present study. Overall, we observed a clear regulation of host immune response driven by DNA methylation upon subclinical mastitis. Further studies on a larger cohort of animals are needed to validate our results and to possibly identify a unique SC methylome that signifies pathogen-specific alterations

    Genomic prediction for latent variables related to milk fatty acid composition in Holstein, Simmental and Brown Swiss dairy cattle breeds

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    Genomic selection (GS) reports on milk fatty acid (FA) profiles have been published quite recently and are still few despite this trait represents the most important aspect of milk nutritional and sensory quality. Reasons for this can be found in the high costs of phenotype recording but also in issues related to its nature of complex trait constituted by multiple genetically correlated variables with low heritabilities. One possible strategy to deal with such constraint is represented by the use of dimension reduction methods. We analysed 40 individual FAs from Italian Brown Swiss, Holstein and Simmental milk through multivariate factor analysis (MFA) to study the genetics of milk FA-related latent variables (factors) and assess their potential use in breeding. A total of nine factors were obtained, and their genetic parameters were inferred under a Bayesian framework using two statistical approaches: the classical pedigree best linear unbiased prediction (ABLUP) and the single-step genomic BLUP (ssGBLUP). The resulting factorial solutions were able to represent groups of FAs with common origin and function and can be considered concise pathway-level phenotypes. The heritability (h2) values showed relevant variations across different factors in each breed (0.03\ua0 64\ua0h2\ua0 64\ua00.38). The accuracies of breeding values predicted were low to high, ranging from 0.13 to 0.72 and from 0.18 to 0.74 considering the pedigree and the genomic model, respectively. The gain in accuracy in genetic prediction due to the addition of genomic information was ~30% and ~5% in validation and training groups respectively, confirming the contribution of genomic information in yielding more accurate predictions compared to the traditional ABLUP methodology. Our results suggest that MFA in combination with GS can be a valuable tool in dairy cattle breeding and deserves to be further investigated for use in future breeding programs to improve cow's milk FA-related traits
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