J Mario Wolosin

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When cell populations are incubated with the DNA-binding dye Hoechst 33342 and subjected to flow cytometry analysis for Hoechst 33342 emissions, active efflux of the dye by the ABCG2/BCRP1 transporter causes certain cells to appear as a segregated cohort, known as a side population (SP). Stem cells from several tissues have been shown to possess the SP(More)
The stem cells of the corneal epithelial lineage are confined to the basal cell layer of the limbus, a vascularized outer corneal rim. These slow cycling cells of great proliferative potential maintain the corneal epithelial mass. Since cell-cell communication plays an important role in development and differentiation, we conducted a comparative examination(More)
When stimulated to secrete HCl the gastric oxyntic cell undergoes profound morphological change. The identifiable apical cell surface is greatly expanded in the stimulated oxyntic cell as compared with nonsecreting ones. To account for this change, one hypothesis proposes that the expanded surface is derived from the fusion of cytoplasmic tubulovesicular(More)
The stromal-to-tear transport of Cl- by the corneal epithelium of the frog is increased by pharmacological effectors (secretagogues) that are known to raise the intracellular levels of cyclic AMP or Ca2+. It has been shown in the past that the Cl- secretagogues increase the apical membrane permeability to Cl- and thus facilitate the cell-to-tear flux of the(More)
Phenotypic features and developmental events involved in the genesis of the limbo-corneal and conjunctival epithelia are described. Together, these two epithelia define the ocular surface. They derive from a small cohort of optic vesicle-induced PAX6+ head ectodermal cells that remain on the surface following lens vesicle formation by the main PAX6+ cell(More)
PURPOSE In the epidermis, the highest clonogenicity, a feature of stem cells (SCs), is found in the smallest keratinocyte. In the limbal-corneal (LC) epithelium the SCs are exclusively localized in the basal epithelial layer of the limbal domain. The current study was conducted to determine whether this spatial SC arrangement is reflected in differences in(More)
The cyanobacterium Synechococcus 6311 adapts to grow in 0.6 M NaCl by developing an efficient system for sodium extrusion. In the present investigation cells loaded with NaC1 were subjected to a large dilution. Changes in fluorescence quenching of acridine orange as a function of transmembrane Na+ gradients provide evidence that Na+/H+ exchange activity(More)
The tight junctions (TJs) present exclusively in between the superficial cells (SC) are an important component for the barrier and ion secretory functions of the corneal epithelium. Electrophysiological studies have demonstrated that digitonin-induced devitalization of overlying cells induces the de novo generation of a paracellular barrier between the(More)
This study concerns the properties of rapid K+ and Cl transport pathways that are present in the (H++K+)-ATPase membrane from stimulated, and secreting, gastric oxyntic cells. Ion permeabilities in the isolated stimulation-associated vesicles were monitored via the rates of H+ efflux under conditions of exclusive H+/K+ counterflux or H+−Cl co-efflux, as(More)