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Introduction: Recent evidence based on cancer stem cell (CSC) models, is boosting the progress of translational research and providing relevant clinical implications in many tumour types, including colorectal cancer. The current failure of standard therapies is attributed to a small fraction of the primary cell population with stem-like characteristics, such as self-renewal and differentiation. Identification of CSCs is based on two different criteria of selection: stemness-selective conditions and direct isolation based on putative stem cell markers expression. CD133, a transmembrane glycoprotein, was associated with tumor-initiating cells derived from several histological variants of tumors, including colon., Areas Covered: In this review the current understandings about CD133 as putative marker of tumour-initiating cells in colorectal cancer (CRC) is described. The focus of the discussion is on the need for additional markers to better identify the cell population able to recapitulate the parental tumor in immunocompromised mice., Expert Opinion: Identification and characterization of CSCs represents a relevant issue to define innovative therapeutic approaches, overcoming the emergence of cancer cell clones capable of evading standard therapy.

It is widely accepted by the scientific community that cancer, including colon cancer, is a "stem cell disease". Until a few years ago, common opinion was that all neoplastic cells within a tumor contained tumorigenic growth capacity, but recent evidences hint to the possibility that such a feature is confined to a small subset of cancer-initiating cells, also called cancer stem cells (CSCs). Thus, malignant tumors are organized in a hierarchical fashion in which CSCs give rise to more differentiated tumor cells. CSCs possess high levels of ATP-binding cassette (ABC) transporters and anti-apoptotic molecules, active DNA-repair, slow replication capacities and they produce growth factors that confer refractoriness to antineoplastic treatments. The inefficacy of conventional therapies towards the stem cell population might explain cancer chemoresistance and the high frequency of relapse shown by the majority of tumors. Nowadays, in fact all the therapies available are not sufficient to cure patients with advanced forms of colon cancer since they target differentiated cancer cells which constitute most of the tumor mass and spare CSCs. Since CSCs are the entities responsible for the development of the tumor and represent the only cell population able to sustain tumor growth and progression, these cells represent the elective target for innovative therapies.

This work reports a nanoscale electro-structural characterisation of Ti/Al ohmic contacts formed on p-type Al-implanted silicon carbide (4H-SiC). The morphological and the electrical properties of the Al-implanted layer, annealed at 1700°C with or without a protective capping layer, and of the ohmic contacts were studied using atomic force microscopy [AFM], transmission line model measurements and local current measurements performed with conductive AFM.The characteristics of the contacts were significantly affected by the roughness of the underlying SiC. In particular, the surface roughness of the Al-implanted SiC regions annealed at 1700°C could be strongly reduced using a protective carbon capping layer during annealing. This latter resulted in an improved surface morphology and specific contact resistance of the Ti/Al ohmic contacts formed on these regions. The microstructure of the contacts was monitored by X-ray diffraction analysis and a cross-sectional transmission electron microscopy, and correlated with the electrical results.

There is no good reason why a gallbladder that has been compressed and displaced by a parasitic or malformative cyst, but is otherwise free of anatomical or irreversible lesions, should be irrevocably sacrificed. Treatment of the primary lesion can thus be followed by re-implantation of the gallbladder. The indications for this surgical technique and its limitations are described with reference to a personal series.