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Transcriptional regulation by the aryl hydrocarbon receptor, for which the environmental toxin 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is the most potent ligand, leads in mammalian liver to the induction of genes for two distinct cytochrome P450 (CYP)1A enzymes, CYP1A1 and -1A2. Fish seem to have only one CYP1A enzyme. CYP1A enzymes have been regarded as(More)
A prospective study comparing the radionuclide skeletal survey with the radiographic survey was performed for 159 children with known primary neoplasm. Forty-four showed radionuclide evidence of metastases, while only 14 had radiographic evidence. Thus, 68% of metastases were discovered by bone imaging alone. No false negative images for metastases were(More)
We describe the theory of a technique for the noninvasive measurement of organ blood flow which is based on the principle of fractionation of cardiac output and is applicable with any recirculating gamma emitting tracer. The technique effectively determines the count rate that would be recorded over the organ if the tracer behaved like radiolabelled(More)
Discitis, intervertebral disc-space infection, and vertebral osteomyelitis form a spectrum of disorders with a probably common bacterial etiology. We studied forty-one children who had symptomatic narrowing of the disc space associated with fever and an elevated erythrocyte sedimentation rate and found that the diagnosis of infection in the spine was(More)
Many rhythmic motor behaviours, including swimming, walking, scratching, swallowing, micturition and sexual climax, are episodic: even in the absence of sensory inputs they exhibit a gradual run-down in frequency before spontaneously terminating. We have investigated whether the purinergic transmitters, ATP and adenosine, control run- down of swimming in(More)
Differentiation of osteomyelitis from cellulitis or septic arthritis can be difficult. The radiological examination often does not have the characteristic features. Seventy of 71 children with osteomyelitis had focal areas of increased radioactivity at the site of the infection. The addition of "blood pool" images aids in the interpretation of the study as(More)
A series of 42 osteoid osteomas is reviewed, and the scintigraphic appearances are described. In all cases, a marked, well-localized area of increased activity was demonstrated at the tumor site in both the blood-pool and standard two-hour images. The blood-pool images were performed after the injection of technetium-99m methylene diphosphate which showed a(More)