Canine IgE monoclonal antibody specific for a filarial antigen: production by a canine x murine heterohybridoma using B cells from a clinically affected lymph node.

Canine popliteal lymph node cells taken at the onset of clinical disease from a rear limb infected with the filarial nematode Brugia pahangi were fused with mouse myeloma cell line P3X63.Ag8.653 cells. Of the several canine immunoglobulin-producing clones from this fusion, one was found to produce canine IgE specific for a filarial nematode antigen. The cell line has undergone limiting dilution cloning six times over the past 3 years and continues to produce monoclonal antibody of the IgE subclass at a rate of greater than 3 mg/l. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) of the cell culture supernatant protein that bound to protein A beads, showed bands at molecular weights (MW) of approximately 75,000 and 25,000 that were characteristic of epsilon and kappa or lambda chains, respectively. A mouse monoclonal antibody specific for canine IgE bound the 75,000 MW band, as demonstrated by Western blot. Western blots of aqueous extracts of adult filarial nematodes demonstrated binding of the canine IgE monoclonal antibody to a single 35,000 MW peptide from B. pahangi but not Dirofilaria immitis; immunochemistry using frozen sections of adult worms, microfilariae and fourth stage larvae revealed focal binding of the monoclonal IgE to worm tissue adjacent to dorsal and ventral cords of only Brugia adults.

Biomechanical evaluation of a toggle pin technique for management of coxofemoral luxation.

Toggle pin stabilization is an accepted technique for the management of coxofemoral (CF) luxation in dogs. The purpose of this study was to determine, in vitro, the respective contributions of several aspects of toggle pin repair to the overall stability of fixation. Factors evaluated were the manner and frequency with which toggle pins oriented on insertion, effect of orientation on toggle pin strength, effect of suture type on ligament prosthesis strength and load sustained by the fixation, and comparison of repair using a modified toggle design to that of capsulorrhaphy. When placed in cadavers using standard technique, conventional toggle pins were found to orient significantly more frequently in one of two possible positions. Mechanical testing of fixations performed in experimentally luxated cadaver hips demonstrated a high (12/20) incidence of toggle pin failure using the conventional implant in the most common orientation. When tested alone, toggle pins were weakest mechanically in this orientation. Rotating the implant 180 degrees increased mean load to failure by 249%. There was no significant difference in load sustained by conventional toggle fixations using No. 2 braided polyester versus 50 lb test monofilament nylon as the suture ligament prosthesis. However, the higher stiffness of the polyester suture may be more favorable for use in this application. Fixation using a toggle rod designed to allow evaluation of construct stability when failure of the toggle is eliminated resulted in an increase in maximum load sustained before luxation (47% of the intact control hips). This load was not significantly different than the resistance to luxation afforded by capsulorrhaphy. This study suggests that when implanting conventional toggle pins, consideration should be given to ensuring placement in the strongest orientation.