Biomedical subjects
N Webb
Publications and source records attributed to N Webb.
Radioiodinated 1-(diethylaminopropyl)-4-phenylpiperazine: a potential brain imaging agent.
The preparation of radioiodinated 1-(diethylaminopropyl)-4-phenylpiperazine, an analog of HIPDM, and its tissue distribution in rats are described. The precursor undergoes facile electrophilic radioiodination with radionuclides of iodine at the no-carrier-added level to give isolated yields in the 69-85% range. Biodistribution studies indicate that the radiochemical is well extracted by the brain (1.68-1.79% ID) and activity is substantially retained for 4 h (greater than 67%). Brain-to-blood ratios during the 0.25-4.0 h period were 15-23:1. The brain uptake and retention as well as the high brain-to-blood ratios suggest the potential use of this agent for regional cerebral blood flow imaging.
Doctors and pressure groups.
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Open-mindedness of first year medical, nursing and social work students.
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Value change during the first year of training: a comparison of medical, nursing, and social work students.
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Biological evaluation of polymers. I. Poly(methyl methacylate).
A series of poly(methyl methacrylate) formulations differing widely in chemical and physical properties was employed for the evaluation of primary screening methods for the assessment of acute toxicity. Materials and USP extracts of materials were tested in parallel. Tissue culture, hemolysis, intradermal irritation, systemic toxicity, muscle implant and histopathologic responses were determined for each of 27 formulations. A determination of the nonvolatile methanol extractable components was carried out on each formulation. The formulations varied with respect to percent, w/w, methyl methacrylate, N,N-dimethyl-p-toluidine, stannous octoate, 3, 4-diamino-toluene and, also, with respect to curing conditions. Volatile components, primarily methyl methacrylate, of three selected formulations were determined quantitatively by vacuum distillation and mass spectrographic analysis. Statistical analysis of the primary data indicated a significant correlation of residue weight (methanol extractable) with hemolytic activity (r = 0.93) and with the cumulative biological response (r = 0.9). Multiple linear regression analysis of residue weights with hemolysis and intradermal irriation responses gave the highest overall correlation (r = 0.96). Hemolytic activity and tissue culture responses were significantly correlated (r = 0.87). It was concluded that the observed variation of biological test results reflected significant differences in the toxicity of the test materials. The poly(methyl methacrylate) series examined was relatively low in toxicity and the biological tests examined, particularly the in vitro tests, were found to be responsive to formulation and curing conditions which indicated their suitability for primary toxicity screening.
Self-concept and substance abuse treatment.
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