Expression of the T cell-specific adapter protein in human tissues.

T cell-specific adapter protein (TSAd) encoded by the SH2D2A gene is expressed in activated T cells, NK cells and endothelial cells, but its tissue expression has not yet been mapped. Here, we have defined the specificity of two commercially available anti-TSAd monoclonal reagents using peptide arrays. We found them to bind separate epitopes in the C-terminal part of TSAd. We then used immunohistochemistry to examine TSAd expression in various human lymphoid and non-lymphoid tissues. Immunostaining of adjacent tissue sections revealed that a substantial fraction of CD3-positive cells in normal lymphoid and non-lymphoid tissues expressed TSAd. In particular, essentially all intra-epithelial T cells appeared to coexpress TSAd. In addition, TSAd expression was observed in endothelial cells of dermal microvessels, while it was not detected in endothelial cells of the other tested tissues. This work provides insight into the expression pattern of TSAd in various healthy human tissues.

Internal sclerostomy with a mechanical trephine versus the neodymium:YAG laser in dogs.

BACKGROUND AND OBJECTIVES: To experimentally compare and contrast the internal sclerostomy produced using a mechanical trephine with that made by an Nd:YAG laser, and to evaluate the healing patterns, efficacy, and technical advantages of each method. MATERIALS AND METHODS: Four healthy dogs with normal eyes were used in this study. The left eye of each dog had an internal sclerostomy performed with an automated mechanical trephine. The right eye of each dog had an internal sclerostomy performed with an Nd:YAG laser. Postoperatively, the intraocular pressure of each eye was measured at regular intervals. The dogs were euthanized successively at 1, 2, 3, and 4 weeks postoperatively, and the morphology of the surgical sites was studied. RESULTS: The Nd:YAG laser was easier to manipulate and technically less demanding than the mechanical trephine. However, the Nd:YAG laser induced more prominent corneal edema and conjunctival hyperemia compared with the automated trephine. Morphology of the tissue response showed tissue necrosis and greater inflammation with the Nd:YAG laser than with the automated trephine. CONCLUSIONS: These two techniques demonstrate differences in technical demands and tissue response. Both are characterized by minimal reactive fibrosis of the episcleral and Tenon's capsule fibroblast.

Experimental evaluation of a hydroxylapatite reservoir tube shunt in rabbits.

BACKGROUND AND OBJECTIVES: Anterior chamber tube shunts of various design are of increasing importance in the surgical management of refractory glaucoma. However, the reservoirs that are commonly used today are made of a silicone or an acrylic material that may become enveloped by a fibrous capsule, which in turn may impede aqueous resorption. In this study, the authors investigated the properties of hydroxylapatite (HA) as a reservoir in gonioimplants, using three different types of HA reservoir designs. It has been demonstrated that HA orbital implants become vascularized, and the authors hypothesized that this feature of HA might modify the development of the fibrous capsule, enhancing the efficacy and decreasing the size of the implants. MATERIALS AND METHODS: HA reservoirs with Silastic tube shunts were implanted in the right eyes of six Dutch-belted rabbits. Clinical examinations were performed and intraocular pressure was measured periodically for 16 weeks postoperatively. Prior to euthanasia, fluorescein-labeled latex microspheres were injected into the anterior chamber to demonstrate implant patency. Light microscopy was used to study the tissue response to the implants and the pathways of aqueous flow. RESULTS: In general, the authors found a granulomatous inflammatory response to the HA accompanied by neovascularization into the implant and minimal fibrous encapsulation of the reservoir. CONCLUSIONS: The use of HA as a suprascleral reservoir has several advantages, the major one being a theoretical increase in the functional lifetime of the implant.