Vapor grown carbon nanofiber based cotton fabrics with negative thermoelectric power

Vapor grown carbon nanofiber (CNF) based ink dispersions were used to dip-coat woven cotton fabrics with different constructional parameters, and their thermoelectric (TE) properties studied at room temperature. Unlike the positive thermoelectric power (TEP) observed in TE textile fabrics produced with similar carbon-based nanostructures, the CNF-based cotton fabrics showed negative TEP, caused by the compensated semimetal character of the CNFs and the highly graphitic nature of their outer layers, which hinders the p-type doping with oxygen groups onto them. A dependence of the electrical conductivity (r) and TEP as a function of the woven cotton fabric was also observed. The cotton fabric with the largest linear density (tex) showed the best performance with negative TEP values around - 8 lV K-1 , a power factor of 1.65 9 10-3 lW m-1 K-2 , and a figure of merit of 1.14 9 10-6 . Moreover, the possibility of a slight e- charge transfer or n-doping from the cellulose onto the most external CNF graphitic shells was also analysed by computer modelling. This study presents n-type carbon-based TE textile fabrics produced easily and without any functionalization processes to prevent the inherent doping with oxygen, which causes the typical p-type character found in most carbon-based TE materialsFEDER funds through COMPETE and by national funds through FCT – Foundation for Science and Technology within the project POCI-01-0145- FEDER-007136. E. M. F. Vieira is grateful for financial support through FCT with CMEMS-UMinho Strategic Project UIDB/ 04436/202

Expression of a novel carbonic anhydrase, CA XIII, in normal and neoplastic colorectal mucosa

BACKGROUND: Carbonic anhydrase (CA) isozymes may have an important role in cancer development. Some isozymes control pH homeostasis in tumors that appears to modulate the behaviour of cancer cells. CA XIII is the newest member of the CA gene family. It is a cytosolic isozyme which is expressed in a number of normal tissues. The present study was designed to investigate CA XIII expression in prospectively collected colorectal tumor samples. METHODS: Both neoplastic and normal tissue specimens were obtained from the same patients. The analyses were performed using CA XIII-specific antibodies and an immunohistochemical staining method. For comparison, the tissue sections were immunostained for other cytosolic isozymes, CA I and II. RESULTS: The results indicated that the expression of CA XIII is down-regulated in tumor cells compared to the normal tissue. The lowest signal was detected in carcinoma samples. This pattern of expression was quite parallel for CA I and II. CONCLUSION: The down-regulation of cytosolic CA I, II and XIII in colorectal cancer may result from reduced levels of a common transcription factor or loss of closely linked CA1, CA2 and CA13 alleles on chromosome 8. Their possible role as tumor suppressors should be further evaluated

RNA delivery by extracellular vesicles in mammalian cells and its applications.

The term 'extracellular vesicles' refers to a heterogeneous population of vesicular bodies of cellular origin that derive either from the endosomal compartment (exosomes) or as a result of shedding from the plasma membrane (microvesicles, oncosomes and apoptotic bodies). Extracellular vesicles carry a variety of cargo, including RNAs, proteins, lipids and DNA, which can be taken up by other cells, both in the direct vicinity of the source cell and at distant sites in the body via biofluids, and elicit a variety of phenotypic responses. Owing to their unique biology and roles in cell-cell communication, extracellular vesicles have attracted strong interest, which is further enhanced by their potential clinical utility. Because extracellular vesicles derive their cargo from the contents of the cells that produce them, they are attractive sources of biomarkers for a variety of diseases. Furthermore, studies demonstrating phenotypic effects of specific extracellular vesicle-associated cargo on target cells have stoked interest in extracellular vesicles as therapeutic vehicles. There is particularly strong evidence that the RNA cargo of extracellular vesicles can alter recipient cell gene expression and function. During the past decade, extracellular vesicles and their RNA cargo have become better defined, but many aspects of extracellular vesicle biology remain to be elucidated. These include selective cargo loading resulting in substantial differences between the composition of extracellular vesicles and source cells; heterogeneity in extracellular vesicle size and composition; and undefined mechanisms for the uptake of extracellular vesicles into recipient cells and the fates of their cargo. Further progress in unravelling the basic mechanisms of extracellular vesicle biogenesis, transport, and cargo delivery and function is needed for successful clinical implementation. This Review focuses on the current state of knowledge pertaining to packaging, transport and function of RNAs in extracellular vesicles and outlines the progress made thus far towards their clinical applications

Products of cells from gliomas: IX. Evidence that two fundamentally different mechanisms change extracellular matrix expression by gliomas

Four human astrocytic gliomas of high grade of malignancy were each evaluated in tissue and in vitro for percentages of cells expressing glial fibrillary acidic protein (GFAP), collagen type IV, laminin and fibronectin assessed by immunofluorescence with counterstaining of nuclear DNA. Percentages of cells with reticulin and cells binding fluorescein-labeled Ulex europaeus agglutinin were also assessed. In tissue, each extracellular matrix (ECM) component was associated with cells in the walls of abnormal proliferations of glioma vessels, and all four tumors had the same staining pattern. Two strikingly different patterns of conversion of gene product expression emerged during in vitro cultivation. (1). In the most common pattern, percentages of all six markers consistently shifted toward the exact phenotype of mesenchymal cells in abnormal vascular proliferations: increased reticulin, collagen type IV, laminin and fibronectin; markedly decreased glial marker GFAP and absent endothelial marker Ulex europaeus agglutinin. The simplest explanation of this constellation of changes coordinated toward expression of vascular ECM markers is that primary glioma cell cultures are overgrown by mesenchymal cells from the abnormal vascular proliferations of the original glioma. These cell cultures were tested for in situ hybridization (ISH) signals of chromosomes 7 and 10. Cells from one glioma had diploid signals. Cells from the other glioma had aneuploid signals indicating they were neoplastic; however, their signals reflected different numerical chromosomal aberrations than those common to neoplastic glia. (2). The second pattern was different. Cells with ISH chromosomal signals of neoplastic glia retained GFAP, and gained collagen type IV. Their laminin and fibronectin diminished, but persisted among a lower percentage of cells. Cloning and double immunofluorescence confirmed the presence of individual cells with glial and mesenchymal markers. A cell expressing GFAP in addition to either fibronectin, reticulin or collagen type IV is not a known constituent of glioblastoma tissue. This provides evidence of a second mechanism of conversion of gene expression in gliomas.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45382/1/11060_2005_Article_BF01052843.pd