ABSTRACT
This paper focuses on the activity spectrum of three dimethylalkyl tertiary amines as potential active molecules and the corresponding ammonium salt-based antifouling (AF) paints. Bioassays (using marine bacteria, microalgae and barnacles) and field tests were combined to assess the AF activity of coatings. Bioassay results demonstrated that the ammonium salt-based paints did not inhibit the growth of microorganisms (except the dimethyldodecylammonium-based coatings) and that the tertiary amines were potent towards bacteria, diatoms, and barnacle larvae at non-toxic concentrations (therapeutic ratio, LC50/EC50, <1). The results from field tests indicated that the ammonium salt-based coatings inhibited the settlement of macrofouling and the dimethylhexadecylammonium-based coatings provided protection against slime in comparison with PVC blank panels. Thus, results from laboratory assays did not fully concur with the AF activity of the paints in the field trial.
Subject(s)
Aquatic Organisms , Biofouling/prevention & control , Biological Assay , Copper/chemistry , Paint/analysis , Polymethacrylic Acids/chemistry , Quaternary Ammonium Compounds/chemistry , Adhesives/chemistry , Animals , Aquatic Organisms/drug effects , Aquatic Organisms/physiology , Bacteria/drug effects , Bacteria/growth & development , Bacteria/metabolism , Carboxylic Acids/chemistry , Clinical Laboratory Techniques , Diatoms/drug effects , Diatoms/physiology , Equipment Contamination/prevention & control , Immersion , Ion Exchange Resins/chemistry , Microalgae/drug effects , Microalgae/physiology , Quaternary Ammonium Compounds/toxicity , Thoracica/drug effects , Thoracica/physiologyABSTRACT
In 385 patients with acute myocardial infarction, lactate dehydrogenase (LD; EC 1.1.1.27) isoenzymes were determined electrophoretically 24, 48, and 72 h after admission. At those times, LD-1/LD-2 ratios exceeding 1 were recorded in 78.9, 88.8, and 92.2% of the cases, respectively. LD-1 ranged from 181 to 2674 U/L, or 21.9 to 66.1% of the total activity. On the first day of hospitalization, 27.3% of the patients demonstrated abnormal LD-5 (greater than 6% of total LD); this finding dropped to 20.5% and 17.4% in the two following days. Early increases in LD-5 were most frequently observed in patients associating inferior infarcts with posterior or lateral extension and having a previous history of myocardial infarction. On day 1, LD-5 was significantly increased in early deceased patients as compared to long-term survivors (9.7% vs 4.9% of total LD, p less than 0.01). LD-5 definitely contributes to the prognostic efficiency of total LD in acute myocardial infarction, but does not replace it as a risk predictor. This study confirms the superiority of total LD over the isoenzyme measurements to achieve short-term prognostication.
