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G Crawford

Publications and source records attributed to G Crawford.

At least 37 records · Page 2Linked to original sources
PubMed1995

Steel can recycling: how to cut costs and support the environment.

This is the first in a series of three articles regarding steel can recycling from foodservice operations of healthcare facilities. This article highlights the benefits of recycling and how steel is recycled across the country; the second will focus on the basic methods of recycling steel cans, and will include information on conducting a waste audit and negotiating with a hauler; the final article will convey a case history of actual foodservice recycling practice from a healthcare facility.

Conservation of Natural Resources↗
PubMed1995

Biomechanical comparison of the sliding hip screw and the dome plunger. Effects of material and fixation design.

We studied the biomechanical behaviour of three sliding fixation devices for trochanteric femoral fractures. These were a titanium alloy sideplate and lag screw, a titanium alloy sideplate and dome plunger with cement augmentation, and a stainless-steel sideplate and lag screw. We used 18 mildly osteoporotic cadaver femora, randomly assigned to one of the three fixation groups. Four displacement and two strain gauges were fixed to each specimen, and each femur was first tested intact (control), then as a two-part fracture and then as a four-part intertrochanteric fracture. A range of physiological loads was applied to determine load-bearing, load-sharing and head displacement. The four-part-fracture specimens were subsequently tested to failure to determine maximum fixation strengths and modes of failure. The dome-plunger group failed at a load 50% higher than that of the stainless-steel lag-screw group (p < 0.05) and at a load 20% higher than that of the titanium-alloy lag-screw group (NS). All 12 lag-screw specimens failed by cut-out through the femoral head or neck, but none of the dome-plunger group showed movement within the femoral head when tested to failure. Strain-gauge analysis showed that the dome plunger produced considerably less strain in the inferior neck and calcar region than either of the lag screws. Inferior displacement of the femoral head was greatest for the dome-plunger group, and was due to sliding of the plunger. The dome plunger with cement augmentation was able to support higher loads and did not fail by cut-out through the femoral head.(ABSTRACT TRUNCATED AT 250 WORDS)

Biomechanical Phenomena↗
PubMed1994

Cytotoxicity of immunoglobulins from amyotrophic lateral sclerosis patients on a hybrid motoneuron cell line.

Patients with amyotrophic lateral sclerosis possess antibodies (ALS IgGs) that bind to L-type skeletal muscle voltage-gated calcium channels (VGCCs) and inhibit L-type calcium current. To determine whether interaction of ALS IgGs with neuronal VGCCs might influence motoneuron survival, we used a motoneuron-neuroblastoma hybrid (VSC 4.1) cell line expressing binding sites for inhibitors of L-, N-, and P-type VGCCs. Using direct viable cell counts, quantitation of propidium iodide- and fluorescein diacetate-labeled cells, and lactate dehydrogenase release to assess cell survival, we document that ALS IgG kills 40-70% of cAMP-differentiated VSC 4.1 cells within 2 days. ALS IgG-mediated cytotoxicity is dependent on extracellular calcium and is prevented by peptide antagonists of N- or P-type VGCCs but not by dihydropyridine modulators of L-type VGCCs. Preincubating IgG with purified intact L-type VGCC or with isolated VGCC alpha 1 subunit also blocks ALS IgG-mediated cytotoxicity. These results suggest that ALS IgG may directly lead to motoneuron cell death by a mechanism requiring extracellular calcium and mediated by neuronal-type calcium channels.

Amyotrophic Lateral Sclerosis↗
PubMed1994

Environmental noise and sleep--a study of arousals, cardiac arrhythmia and urinary catecholamines.

Nine adult subjects with documented cardiac arrhythmia were studied during 4 nights of sleep in a laboratory. A sleep polygraph and single-channel electrocardiogram were recorded continuously throughout each night. After the 1st night's familiarization, the subjects were presented with 1 night each of 50 calibrated aircraft or truck noise events. One other night was noise-free. Intervals containing noise and paired quiet intervals were examined for sleep stage at interval onset, number of sleep stage changes and ventricular premature contractions (VPCs). Overnight urinary catecholamines were also assayed. It was found that noise increased the likelihood of arousal responses to the same extent in all sleep stages (p < 0.05). Four subjects showed frequent VPCs during the experiment. These VPCs were significantly related to sleep stage (p < 0.05) but not to noise events. Excretion of urinary catecholamines did not differ between noise and quiet nights.

Adult↗