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J DeBruin

Publications and source records attributed to J DeBruin.

3 recordsLinked to original sources
PubMed1988

Quantitative analysis of mouse interferon-beta receptor-mediated endocytosis and nuclear entry.

The dynamics of internalization and transport of murine interferon-beta (MuIFN-beta) to the cell nucleus was studied in cultured L929 mouse fibroblasts employing postembedding, ultrastructural quantitative immunocytochemistry. Cells preincubated with MuIFN-beta at 4 degrees C were transferred to 37 degrees C for various times, and then fixed and embedded in Lowicryl K4M. Internalized native IFN molecules were identified and quantified on the surface of ultrathin sections with monoclonal (MAb) or polyclonal (PAb) anti-IFN antibodies and a colloidal gold-protein A (CGPA) conjugate. Immunocytochemically recognizable MuIFN-beta molecules entered the cytoplasm by receptor-mediated endocytosis and were translocated via transport vesicles to the nuclear envelope. IFN molecules entered the nucleus through nuclear pores and accumulated maximally in the dense chromatin within 3 min of incubation of the cells at 37 degrees C. The data presented constitute the first direct observation of the dynamics of the extremely rapid transfer of ligand to its intracellular target, in this case, the cell nucleus.

Animals↗
PubMed1975

Endothelial survival in corneal tissue stored in M-K medium.

Cat corneas were stored at refrigerator temperatures in M-K medium (TC-199, 5% dextran), modified M-K medium (TC-199, 1% chondroitin sulfate), or on the intact globe in moist chambers for intervals of one to nine days. Less than 5% of the endothelial cells stained with trypan blue in corneas stored one to four days, regardless of the method of storage. In contrast, after five days, 20% or more of the cells took up the stain in 17 to 21 corneas stored in M-K medium. Although stain uptake indicated nonviability of cells, most of the endothelial cells remained structurally intact when observed by scanning and transmission electron microscopy unless the corneas were incubated in fresh TC-199 for two hours at 35 degrees C before trypan blue staining. In that case, the percentages of disrupted cells observed at each time interval correlated with the percentages of cells that had stained in each cornea. These results indicated that storage in M-K medium did not extend the time donor coreas can be stored before transplantation beyond four days.

Animals↗