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Biomedical subjects

R S Fox

Publications and source records attributed to R S Fox.

8 recordsLinked to original sources

In vitro detection of heparin-induced humoral antiplatelet activity.

We investigated the etiology of thrombocytopenia, with or without platelet thrombi, occurring while patients are receiving parenteral heparin. We used two in vitro methods to detect possible humoral factors in the sera of patients who became thrombocytopenic while receiving heparin. In the presence of heparin, four of four such patients' serum caused platelet aggregation. Only serum from the patient most severely affected clinically caused release of platelet factor 3 (PF3). All control sera gave negative results by both methods. We propose that platelet aggregation studies may be a sensitive and reliable method of confirming that thrombocytopenia occurring during heparin therapy is due to a humoral factor requiring the presence of heparin.

Adenosine Diphosphate

Short-term changes in tonic accommodation.

Experiments were performed to determine the diurnal variation of, as well as the influence of total darkness on, tonic accommodation. In general, under both conditions trend analysis showed that variations in tonic accommodation over time were either nonsystematic in nature or could be best described by a simple linear function. Given the relatively small range of mean tonic accommodation values over time (0.5 to 1.1 D), the results demonstrate the robustness and stability of tonic accommodation under naturally occurring viewing conditions during the course of a day. In contrast, during the 2-hr period in total darkness, tonic accommodation exhibited a three-fold increase in mean range (0.6 to 2.5 D) as well as a significant increasing linear trend in some subjects, suggesting less stability of tonic accommodation in the absence of visual stimuli.

Accommodation, Ocular

Hand injuries: incidence and epidemiology in an emergency service.

During a four-month period, 1,164 patients presented to the surgical section of our Emergency Services (ES) with chief complaints involving the hand. Patient records were analyzed for several variables including demographics, diagnosis and therapeutic procedures. Lacerations were the most frequent injury, 61.5% (n=716) with deep structure injuries present in 6.1% (n=44). Of deep structure injuries, 36.4% were tendon lacerations, 27.2% were nerve injuries, and 36.4% were compound fractures. "Bites" accounted for 5.2% (37) of all lacerations, eight of which were human bites. Fractures were the second most frequent injury, (11.4%) and involved 143 separate bones. Infections were present in 7%; over half were paronychias. There were 42 (3.6%) thermal injuries.

Adolescent

Locomotion of bluefish.

1. Pressure previously measured on the body surface of swimming bluefish were resolved into their backward vectorial components to allow calculation of profile drag. It was 0.18 kg at a speed of 1.8 m/sec. Tangential drag was calculated as if for a thin plate of an area equal to that of the fish. It was 0.08 kg at 1.8 m/sec. Net drag, 0.26 kg, was the sum of profile and tangential drag. 2. Thrust and drag also were calculated from the changes of acceleration measured during steady swimming, assuming that thrust took place only during the acceleration phase, whereas drag occurred during both acceleration and deceleration. This drag was 0.08 kg at a speed of 1.1 m/sec. It is compatible with the drag of 0.26 at 1.8 m/sec calculated from profile and tangential drag provided drag varies as the square of velocity. 3. The force required to produced maximal acceleration was measured during a scare. It was calculated to be 6.9 kg at a peak acceleration of 3 g. 4. The compression strength of th vertebrae was found to be approximately 20 kg per cm2, or roughly three times the force encountered during maximal acceleration. This safety factor of 3 would be reduced when the back was curved, or if opposing groups of muscles were under tension. 5. The finding that a bluefish can accelerate at 3 g and that the vertebral column is strongg enough to withstand this force indicates that the muscles and body structure of a bluefish would be able to withstand the force of gravity if the fish were otherwise equipped for terrestrial life. This fish may have evolved these strengths simultaneously with land animals. It is speculated that other fish may have evolved some degree of strength to overcome inertia and drag during aquatic locomotion, and this evolution may have been a prelude to terrestrial locomotion.

Acceleration