PubMed · 4885940
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J E Gamble. 1969. Orbital floor implants.. https://doi.org/10.1001/archotol.1969.00770020598008
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Acrylate esters are important chemicals in the plastics industry, whose toxicity is theorized to involve alkylation of critical cellular nucleophiles via the Michael addition. Carboxylesterase-mediated hydrolysis of acrylates may be a detoxification mechanism as the unsaturated acid produced is not electrophilic under physiological conditions. Using purified porcine liver carboxylesterase, the enzymatic hydrolysis of several acrylate esters was characterized to determine Km and Vmax values for each ester. The Km (microM) and Vmax (nmol/min) values observed for ethyl acrylate were 134 +/- 16 (S.D.) and 8.9 +/- 2.0, respectively. While the Km for ethyl methacrylate was not significantly different, the Vmax 5.5 +/- 2.5, was significantly lower compared with the corresponding value for ethyl acrylate. The Km and Vmax for butyl acrylate were 33.3 +/- 8.5 microM and 1.49 +/- 0.83 nmol/min, respectively, and the corresponding values for its alpha-methyl analog were not significantly different. The Km and Vmax for tetraethyleneglycol dimethacrylate were 39 +/- 15 microM and 2.9 +/- 1.0 nmol/min, respectively. The Vmax for ethyleneglycol dimethacrylate, 6.9 +/- 2.4 nmol/min, was significantly higher than that of the larger bifunctional ester tetraethyleneglycol dimethacrylate, but the Km was not significantly different. These results indicate that alpha-methyl substitution appears to have a minor effect in the enzymatic hydrolysis of acrylates, and suggest that the relative toxicity of acrylates is not due to differences in carboxylesterase-mediated hydrolysis.
Interleukin-6 (IL-6) may be important in the pathogenesis of HIV-1 because of its ability to induce HIV-1 expression in infected cells in vitro. Tenidap, a structurally and functionally novel antirheumatic drug affecting diverse biologic processes, has been shown to reduce IL-6 production by peripheral blood mononuclear cells stimulated with lipopolysaccharide. Tenidap also inhibits the activity of chloride-bicarbonate exchangers and causes acidification of the cytoplasmic compartment that is similar to the effect of the anion transport inhibitor UK5099. Furthermore, tenidap inhibits the cyclooxygenase-mediated pathway of arachidonic acid metabolism as do the nonsteroidal antiinflammatory drugs (NSAIDs). Here we show that tenidap decreased HIV-1 replication as measured by p24 core antigen in the acutely infected CD4+ T-lymphocyte lines H9 and Jurkat, in the acutely infected monocyte line U937, and in its chronically infected subclone U1.8/HIV. These effects were seen at concentrations in the range of 3 to 15 microM, well below those toxic to cells. The antiviral effects of tenidap may be independent of its ability to reduce IL-6 production based on the observations that these effects were as prominent in IL-6 nonresponsive lines as in IL-6 responsive lines and that the inhibition of p24 production was not reversed by exogenous IL-6.
4-Dimethylaminobenzyl alcohol (DMOH) and 4-dimethylaminobenzyl methacrylate (DMMO) were used as the activators in the benzoyl peroxide initiated redox polymerization for the preparation of acrylic bone cement based on poly(methylmethacrylate) beads of different particle size. The residual monomer content of the cured cements was about 2 wt %, independent of the redox system used in the polymerization, indicating that the activating effect of the tertiary aromatic amines DMOH or DMMO was sufficient to reach a polymerization conversion similar to that obtained with the benzoyl peroxide (BPO) N,N-dimethyl-4-toluidine (DMT) system. The BPO/DMOH and BPO/DMMO redox systems provided exotherms of decreasing peak temperature and increasing setting time, and the cured materials presented higher average molecular weight and similar glass transition temperatures in comparison with those obtained when DMT was used as the activator. In addition, these activators are three times less toxic than the classical DMT.