Force plate analysis of triple pelvic osteotomy for the treatment of canine hip dysplasia.

Triple pelvic osteotomy was performed in 15 dogs with bilateral hip dysplasia. Ten dogs were treated bilaterally and five dogs were treated unilaterally. Ten untreated dogs with normal hips served as controls. Force plate analysis, lameness evaluation, and radiography were performed before surgery and at weeks 5, 10, 15, and 28. Three dogs treated unilaterally were euthanatized and the hips were examined grossly and microscopically. Force plate data indicated that young dysplastic dogs transmitted significantly less vertical force through the hip joints than normal dogs. The force transmitted through treated hips reached or approached control levels by week 28 and was significantly greater than the force transmitted through untreated hips. Clinical lameness resolved in 92% of limbs and progression of radiographically detectable degenerative joint disease was minimal. Gross and microscopic degenerative changes in the articular cartilage were similar in the treated and untreated hips. The synovial membrane was less reactive in treated hips.

A strain-gauge study of the effect of external fixation on the canine tibia.

Electrical resistance rosette strain gauges bonded directly to the surface of the midshaft of the normal canine tibia were utilized to study the effect of the AO external skeletal fixator on the magnitude and orientation of the peak strain values recorded during locomotion. The application of the fixator in a single lateral bar configuration resulted in a significant decrease in surface bone strain magnitude but in only minor changes in the orientation of those strains. However, in only one of three dogs tested did the addition of a second external connecting bar result in significant further decreases in bone strain.

Monoclonal antibodies to acetylcholine receptor secreted by human x human hybridomas derived from lymphocytes of a patient with myasthenia gravis.

Peripheral blood lymphocytes of a patient with myasthenia gravis (MG) were fused to the non-secreting human lymphoblastoid line HuNSI to produce human x human hybridomas that secrete monoclonal antibodies (mAb) to acetylcholine receptor (AChR). Screening of hybridomas for antibody production involved an enzyme-linked immunosorbent (ELISA) assay with AChR from Torpedo californica (TAChR). 25 of 302 wells tested (8.3%) were positive for anti-AChR antibody production and have been stable in their secretion of mAb for eleven months. Nine lines have been studied in detail. All produced IgM mAb, and most had greater activity against membrane-bound TAChR, than against solubilized TAChR. For anti-AChR clones, the mAb concentration in culture supernatants ranged from 2 to 33 micrograms/ml. Saturation curves of binding to TAChR performed on 4 lines demonstrated dissociation constants (Kds) estimated to range from 0.1-1.0 nM. The patient whose lymphocytes were used in this study had a serum anti-AChR antibody concentration of 243nM against human AChR and 15nM against AChR from T. californica. The results demonstrate the feasibility of producing stable human x human hybridomas secreting mAb to the autoantigen from the peripheral blood of patients with organ-specific autoimmune diseases. The mAb produced here may prove to be useful in analyzing, and possibly treating, the autoimmune phenomena in MG.

Evolution of antibody structure and effector functions: comparative hemolytic activities of monomeric and tetrameric IgM from rainbow trout, Salmo gairdnerii.

Monomeric and tetrameric IgM anti-haptin antibodies isolated from the sera of rainbow trout (S. gairdnerii) by immunoaffinity chromatography were compared both immunochemically and with regard to their functional abilities to lyse haptenated trout erythrocytes in the presence of trout complement. The two populations had similar binding affinities for hapten and apparently identical L chains, but differed in H chain peptide maps and immunoreactivity with rabbit anti-trout H chain serum. These differences could not be attributed to J-chain. The abilities of the two antibody subpopulations to activate C to lyse haptenated trout erythrocytes also differed dramatically. Such functional differences are not simply explained by the greater avidity of the tetrameric form since preliminary studies show that the monomeric form of trout IgM activates C via an alternative pathway mechanism while the tetrameric form activates both classical and alternative pathway mechanisms. Results suggest divergent evolution of antibody structures involved in the familiar effector functions (C activation, transport, etc.).

Human aglycosyl-IgG exhibits increased hydrophobicity. Binding/fluorescence studies with 8-anilinonaphthalene-1-sulfonic acid (ANS).

Human monoclonal, aglycosyl-IgG produced in vitro in the presence of tunicamycin, was compared with its native and acid pH-altered counterparts for their respective abilities to bind the fluorescent hydrophobicity probe, 8-anilinonaphthalene sulfonate. A novel technique based on continuous-flow dynamic dialysis (Sparrow et al., 1982, Anal. Biochem. 123:255-264) allowed binding studies under non-equilibrium conditions. While the native IgG conformation exhibits two, weak ANS binding sites (ca. 10(3) l/mol), aglycosyl-IgG has one weak and one moderate affinity (least squares average Ka = 2 X 10(4) l/mol) site, and the acid conformer binds yet another two ANS molecules with moderate affinity (4 X 10(4) l/mol). Increases in affinity and in the number of sites correlate roughly with increased relative percent fluorescence by conventional fluorimetry. The fluorescence lifetime of ANS bound to altered IgGs is about 10% longer (T2 = 15 nsec by time-resolved fluorimetry) than that for native IgG. All populations also exhibit a rapid decay component (T1 = 3 nsec) analogous to that seen for ANS in 50% aqueous dioxane. Results are discussed in relation to structural role(s) for IgG-linked heterosaccharides.

Diagnosis of Bernard-Soulier syndrome and Glanzmann's thrombasthenia with a monoclonal assay on whole blood.

Two hereditary platelet disorders, Bernard-Soulier syndrome and Glanzmann's thrombasthenia, are characterized by selective deficiencies of platelet membrane glycoproteins. Murine monoclonal antibodies were developed against platelet membrane glycoprotein Ib and against the glycoprotein IIb/IIIa complex. A rapid whole blood assay for the deficiency of these glycoproteins was developed and used to study whole blood samples from six patients with Glanzmann's thrombasthenia and three patients with Bernard-Soulier syndrome. Patients with type I and type II Glanzmann's thrombasthenia were easily detectable with this assay. This permits the diagnosis of these disorders on 200 microliters of whole blood within 2 h of blood sampling.

Comparative kinematic analysis of bipedal and quadrupedal locomotion: a cyclographic technique.

This paper shows the convention for, and applicability of, a new computer-aided cyclographic technique for kinematic analysis of locomotion in quadrupeds. Comparison is made of the walking, trotting and galloping patterns of a reference quadruped, Canis familiaris. The method is effective where an investigator required an accurate evaluation of limb movement in the cranio-caudal plane.

The process of habituation to treadmill walking: a kinematic analysis.

Initial work toward a more definitive kinematic analysis of perceptual-motor processes involved initially in accommodation of naive subjects to treadmill walking is described. The kinematic cyclograph technique holds promise of achieving this.