Prednisolone reduces the ability of serum to activate the IGF1 receptor in vitro without affecting circulating total or free IGF1.

Objective: End-point bioassays based on thymidine or sulfate incorporation have demonstrated that glucocorticoid (GC) treatment inhibits serum IGF1 action, but the mechanism is unknown as serum IGF1 concentrations have been reported to either increase or remain unchanged.

Aim: To investigate whether GC treatment affects the ability of serum to activate the IGF1 receptor (IGF1R) in vitro (i.e.

Attempting to distinguish between endogenous and contaminating cytokeratins in a corneal proteomic study.

Background: The observation of cytokeratins (CK's) in mass spectrometry based studies raises the question of whether the identified CK is a true endogenous protein from the sample or simply represents a contaminant. This issue is especially important in proteomic studies of the corneal epithelium where several CK's have previously been reported to mark the stages of differentiation from corneal epithelial stem cell to the differentiated cell.

Methods: Here we describe a method to distinguish very likely endogenous from uncertain endogenous CK's in a mass spectrometry based proteomic study.

Immunohistochemical markers for corneal stem cells in the early developing human eye.

The corneal epithelium is continuously being renewed. Differentiated epithelial cells originate from limbal stem cells (LSCs) located in the periphery of the cornea, the corneoscleral limbus. We have recently identified superoxide dismutase 2 (SOD2) and cytokeratin (CK) 15 as limbal basal cell markers and potential markers for LSCs and early transient amplifying cells in human adults.

Differences in the protein expression in limbal versus central human corneal epithelium--a search for stem cell markers.

In the search for potential limbal stem cell protein markers, the purpose of this study was to characterize differences in protein expression between human central and limbal corneal epithelium by a proteomic approach using two-dimensional polyacrylamide gel electrophoresis (2D PAGE) combined with mass spectrometry (LC-MS/MS). The results were subsequently confirmed by Western blotting and immunohistochemistry. We detected more than 1000 protein spots in each gel.