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Biomedical subjects

J E Wirth

Publications and source records attributed to J E Wirth.

4 recordsLinked to original sources
PubMed1989

Electron microscopic studies of human mixed saliva.

With foam components removed, mixed saliva from three donors were solidified in liquid nitrogen and sectioned, mounted, and fixed. Examination by transmission (TEM) and scanning (SEM) electron microscopy and energy-dispersive X-ray (EDAX) analysis were performed for paraformaldehyde-fixed sections, some of which were OsO4-postfixed. The TEM and certain SEM examinations showed the presence of fine and dense salivary network structures, seemingly originating from the major fibrous components. In OsO4-treated sections, TEM pictures showed reticulated arrangements with open cellular diameters down to 0.2 microns. The EDAX analyses particularly showed the presence of Ca, Fe, K, P, and S, with increased Ca readings in major components. Untreated sections showed that strands, with diameters of more than 1-2 microns, had more electron-dense central portions than peripheries and sometimes had interior, very electron-dense, granules. The observed features indicate that saliva has internal structures consistent with its colloid chemical characteristics.

Adult↗
PubMed1988

Identification of the interleukin-2 receptor (IL-2R) on human leukemic T cells using colloidal gold and scanning electron microscopy.

Results of studies demonstrating the identification of the interleukin-2 receptor (IL-2R; i.e., anti-Tac) on the membrane ultra-structure of human leukemic T cells with an antibody carrying an electron dense colloidal gold microsphere (e.g., immunogold) that was visualized using a scanning electron microscope (SEM) are reported. Our IL-2R model system employed HTLV-1 retrovirus-infected lymphoblastoid cells of the long-term human leukemic T cell line HUT-102B2. The presence of the IL-2R on these cells was defined using a double antibody procedure that employed as the primary antibody a purified mouse monoclonal anti-Leu-IL-2R antibody (mIgGlk, anti-Tac, CD25), and used as the secondary antibody a goat anti-mouse IgG (gamma-chain specific) antibody that had been covalently bonded to a 40 nm colloidal gold particle. More than 95% of the HUT-102B2 were IL-2R+, and there was a uniform distribution of the IL-2R over the surface of the cells. Corresponding controls were employed in all examinations and included IL-2R- Jurkat human leukemic T cells and isotype identical immunoglobulins. The primary and secondary antibody reagents contained whole human serum and bovine serum albumin, and there was no evidence of the non-specific binding of these antibodies. These studies are the first to demonstrate the presence of a lymphokine receptor on the surface architecture of a cell. We anticipate no difficulty in applying the immunogold/SEM technology to define both normal and malignant cell membrane receptors for other cytokines.

Cell Line↗
PubMed1979

Tissue response to surface-treated tantalum implants: preliminary observations in primates.

Samples of capacitor grade tantalum were surface-treated by a variety of methods. These surface treatments allowed testing of the same basic material which was mill-finished, metallurgically polished, electrochemically oxidized, sintered with a porous surface, and glow-discharged. Surface characterization was accomplished by contact angle measurements, Scanning Electron Microscopy, energy-dispensed x-ray analysis, and internal reflection spectroscopy. Subsequent to characterization, the material was surgically implanted in the subperiosteal region of the mandible, the buccal mucosa, and the subcutaneous paravertebral region of the back of Macaca speciosa (stumptail monkey). The tissue reaction at intervals of up to three weeks was evaluated morphologically and ultrastructurally. Significant differences in tissue response were noted at the interfaces with glow-discharge-treated versus lower surface energy samples. Adjacent to the glow-discharge-treated implants, two distinct tissue zones were identified. Zone No. 1, nearest the implant, exhibited an increased cellularity. This consisted of 4-5 layers of highly active mesenchymal cells or fibroblast-like cells with spindle-shaped nuclei and prominent cytoplasmic features. At various foci along the interface, hyperchromatic nuclear forms were noted to project into the space left by removal of the implant. These observations, coupled with a predominance of intercellular ground-substance material and less collagen at the interface, may indicate some form of bioadhesion. The deeper Zone No. 2 was 2-3 times as thick consisted of typical fibroblastic cells with a lamellar configuration, bordered by an occasional delicate-lined space. Independent of implantation site or surface texture, all other implants showed occasional multinucleated giant cells and a decrease in the cellular character of Zone No. 1. Both zones were reduced in thickness and composed of more mature fibroblasts. Some specimens exhibited intracytoplasmic vacuolization. It may be concluded, therefore, that surface-free energy of the implanted specimens played a significant role in inducing differential tissue response to otherwise similar pure metal samples.

Animals↗