Expression of human CD46 modulates inflammation associated with GalTKO lung xenograft injury.

Evaluation of lungs from GalTKO.hCD46 pigs, genetically modified to lack the galactose-α(1,3)-galactose epitope (GalTKO) and to express human CD46, a complement regulatory protein, has not previously been described. Physiologic, hematologic and biochemical parameters during perfusion with heparinized fresh human blood were measured for 33 GalTKO.hCD46, GalTKO (n = 16), and WT pig lungs (n = 16), and 12 pig lungs perfused with autologous pig blood. Median GalTKO.hCD46 lung survival was 171 min compared to 120 for GalTKO (p = 0.27) and 10 for WT lungs (p < 0.001). Complement activation, platelet activation and histamine elaboration were significantly reduced during the first 2 h of perfusion in GalTKO.hCD46 lungs compared to GalTKO (ΔC3a at 120' 812 ± 230 vs. 1412 ± 1047, p = 0.02; ΔCD62P at 120' 9.8 ± 7.2 vs. 25.4 ± 18.2, p < 0.01; Δhistamine at 60' 97 ± 62 vs. 189 ± 194, p = 0.03). We conclude that, in addition to significant down-modulation of complement activation, hCD46 expression in GalTKO lungs diminished platelet and coagulation cascade activation, neutrophil sequestration and histamine release. Because GalTKO.hCD46 lung failure kinetics correlated directly with platelet and neutrophil sequestration, coagulation cascade activation and a rise in histamine levels within the first hour of perfusion, further progress will likely depend upon improved control of these pathways, by rationally targeted additional modifications to pigs and pharmacologic interventions.

A correlation between shoulder laxity and interfering pain in competitive swimmers.

Shoulder pain in the swimming athlete that interferes with effective training is serious and may result in decreased performance. Based on the hypothesis that shoulder laxity is an important factor in shoulder pain, this study of 40 senior national and elite swimmers was undertaken. A questionnaire identified those athletes currently suffering from such pain. Shoulder laxity was assessed using standard clinical tests, from which a laxity score was derived. A statistically significant correlation was identified between the shoulder laxity score and the presence of interfering shoulder pain, confirming the hypothesis of the study. These results have direct implications for training the symptomatic athlete.

Enhancement of blood lactate clearance following maximal swimming. Effect of velocity of recovery swimming.

Swimming is an endurance-intensive sport resulting in accumulation of lactate. Repeat performances are often necessary in championship events. Lactate produced during a maximal effort requires time to metabolize to a base level. If this does not occur, performance in a repeat effort may be impaired. Thus, techniques to enhance lactate clearance are of potential benefit to the athlete. We have demonstrated previously that swimming at 65% of maximum velocity significantly improved lactate clearance over passive resting. This study tested the effect of various swimming velocities on lactate clearance. Following a maximal swim, blood lactate clearance was tracked during a 15 minute cool down swim. Velocities of 55%, 65%, and 75% of maximum were tested. The results confirmed that cool down swimming will return lactate values to near resting levels in the test interval. However, statistical superiority of any of the test velocities was not demonstrated. The intensity of the swim should be below the lactate accumulation level. The 65% of maximum velocity was felt by all swimmers to be most comfortable and is a good target velocity for the athlete to reference.

Acquisition of matching - to - sample performances in severe retardation: learning by exclusion.

Immediate discriminative control by spoken words was examined in a profoundly retarded, mute young man. The subject learned to select food items from a two-choice display when the food names were spoken, in a matching-to-sample format. Then a new food was presented as one choice, and a novel name was the sample. The subject selected the new food in response to the first presentation of the novel name. It appeared that the subject rejected or "excluded" the trained food which was the other alternative. This "exclusion" performance was obtained errorlessly with fourteen of sixteen new foods and novel names. Subsequent test suggested that the subject had learned the relations between all the new foods and novel names, after a history of reinforced exclusion trials. The method also proved successful with pictures. Prerequisite baseline training may have been critical, particularly differential auditory control by previously trained names. The procedures systematically replicated previous research on the exclusion paradigm, and suggested a potentially errorless, efficient teaching method for individuals without functional language.