Biomedical subjects

T McFall

Publications and source records attributed to T McFall.

14 recordsLinked to original sources

PubMed1991

Multilevel occlusive vascular disease presenting with gangrene.

The medical records of all patients subjected to lower extremity amputations during a 3-year period were reviewed. It was shown that advanced age and the presence of multiple medical problems do not predispose to higher levels of limb loss. Although diabetic patients more frequently undergo amputation because of sepsis than their nondiabetic counterparts, the diabetic state was not found to be associated with a greater likelihood of above knee (AK) procedures. Prior arterial surgery was not shown to make AK amputation more likely, but it was disconcerting to note that limb salvage was not achieved in many individuals despite patent proximal inflow revascularization procedures. This initial study showed that several presumed risk factors were not predictors of amputation level. Those patients requiring AK amputations had a greater frequency of combined segment (aortoiliac and femoropopliteal) occlusive disease than those who had successful amputations at more distal levels. A follow-up study of 41 consecutive patients presenting with tissue loss due to combined segment occlusive disease was performed. Eighteen (Group I) underwent inflow procedures only, while 23 (Group II) also underwent distal revascularization. The groups were similar with respect to age, risk factors, extent of tissue loss and sepsis. At 1 year 10 (56%) Group I and only 3 (13%) Group II patients required major amputation (P = 0.01). Distal bypass, in addition to an inflow procedure, is recommended for those who present with tissue loss due to multilevel arterial occlusion.

Adult↗

PubMed1984

Microbial mutagenicity of isomeric two-, three-, and four-ring amino polycyclic aromatic hydrocarbons.

The isomers of various two-, three-, and four-ring amino polycyclic aromatic hydrocarbons were tested for mutagenic activity using a microbial plate incorporation test with four Salmonella typhimurium strains (TA98, TA100, TA1535, and TA1537). All compounds were assayed with an S9 metabolic activating enzyme system. The two-ring compounds were tested only with TA98. All were weakly mutagenic (1-10 rev/micrograms) except 2-aminobiphenyl, which was not mutagenic under these test conditions. All except two of the 13 fused three-ring compounds (aminofluorenes, aminoanthracenes, and aminophenanthrenes) were active frame shift mutagens; only the aminophenanthrenes were active base-pair mutagens. The potency of this group of isomeric compounds ranged from moderately (approximately 20 rev/microgram) to strongly (greater than 5,000 rev/microgram) mutagenic. As a group, the pericondensed four-ring amino compounds were the most mutagenic of the three groups tested. All of the aminofluoranthene and aminopyrene isomers showed significant mutagenic activity with TA98, TA100, and TA1537. In general, the mutagenic potency of the amino polycyclic aromatic compounds tested was highly dependent on the structural position of the amino group.

Animals↗

PubMed1984

Mutagenic activity of methyl-substituted tri- and tetracyclic aromatic sulfur heterocycles.

A number of polycyclic aromatic sulfur heterocycles have been identified in coal-derived products and in shale oils. The mutagenic activity of some of these compounds, including dibenzothiophene, benzo[b]naphtho[1,2-d]thiophene, benzo[b]naphtho[2,1-d]thiophene and benzo[b]naphtho[2,3-d]thiophene have been determined using the Salmonella/microsome mutagenicity test. These compounds demonstrated either very weak or no mutagenic activity. The methyl derivatives of each of these four compounds were assayed for mutagenic activity. Salmonella typhimurium TA98 was used as the tester strain. All assays required a rat-liver homogenate metabolic activator. Five of the methylated derivatives, 1-methylbenzo[b]naphtho[1,2-d]thiophene, 3-methylbenzo[b]naphtho[1,2-d]thiophene, 1-methylbenzo[b]-naphtho[2,1-d]thiophene, 6-methylbenzo[b]naphtho[2,1-d]thiophene and 4-methylbenzo[b]naphtho[2,3-d]thiophene demonstrated mutagenic activity. However, activity was observed only at high concentrations of the metabolic activator.

Animals↗

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