Potent tumor-initiating activity of the 3,4-dihydrodiol of 7,12-dimethylbenz(a)anthracene in mouse skin.

The abilities of the racemic trans-3,4-, 5,6-, and 8,9-dihydrodiols of 7,12-dimethylbenz(a)anthracene to initiate skin tumors in mice were determined by using a two-stage system of tumorigenesis. The 7,12-dimethylbenz(a)anthracene trans-3,4-dihydrodiol was found to be much more active as a tumor initiator than the parent hydrocarbon. The 7,12-dimethylbenz(a)anthracene trans-5,6- and 8,9-dihydrodiols were essentially inactive as skin tumor initiators. Our results suggest that the 3,4-dihydrodiol of 7,12-dimethylbenz(a)anthracene is a proximal carcinogen and that the "bay region" diol-epoxide may be the ultimate carcinogenic form of DMBA.

Stability of various total nutrient admixture formulations using Liposyn II and Aminosyn II.

The compatibility of a safflower oil-soybean oil lipid emulsion (Liposyn II) with dextrose and amino acid injection (Aminosyn II) with or without electrolytes was studied in total nutrient admixtures (TNAs). The admixtures studied were divided into two groups. In group 1, 15 admixtures representing six different combinations of Liposyn II, Aminosyn II, and dextrose injection were studied. In group 2, nine admixtures representing nine combinations of Liposyn II, Aminosyn II with Electrolytes, and dextrose injection were studied. Both 10% and 20% concentrations of the fat emulsion, amino acid concentrations of 7, 8.5, and 10%, and dextrose injections of 10, 40, 50, and 70% were used. The core admixture components were placed in an ethylene vinyl acetate container in the following sequence: fat, amino acids, dextrose. One of two combinations of electrolytes and trace metals was added to each admixture at the end of mixing. Multivitamins were added to each TNA just before 24-hour storage at room temperature (25 +/- 4 degrees C). Four admixtures were tested after one day at room temperature, six after two days at 5 degrees C plus one day at 30 degrees C, and 14 after nine days at 5 degrees C plus one day at room temperature. Measurements of pH, emulsion particle size, and zeta potential (electrostatic surface charge of lipid particles) were made after visual inspection of each admixture. Concentration of individual amino acids and dextrose were determined by appropriate chromatographic techniques initially and at the end of the storage period. The TNAs retained a uniform, milk-like appearance under all storage conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Stability of total nutrient admixtures using various intravenous fat emulsions.

The stability of four lipid emulsions with amino acids and dextrose in total nutrient admixtures (TNAs) was studied. The admixtures were divided into three groups. In group 1, 24 admixtures representing 20 different combinations of Liposyn II (safflower oil-soybean oil fat emulsion) with various manufacturers' amino acids (FreAmine III, Travasol, Novamine, Nephramine, and RenAmin) were tested. In group 2, 19 TNAs representing 14 combinations containing soybean-oil emulsions (Intralipid, Travamulsion, and Soyacal) and Aminosyn II amino acids were studied. In group 3, 14 TNAs representing 9 combinations containing the above soybean oil emulsions and Aminosyn II with Electrolytes were tested. Both 10% and 20% concentrations of fat emulsion, various amino acid concentrations ranging from 5.4% to 11.4%, and dextrose injections of 10, 20, 40, 50, and 70% were used. The admixtures were compounded in an ethylene vinyl acetate container. The mixing sequence involved transfer of fat emulsion to the empty container, followed by amino acids and dextrose. One of two electrolyte and trace metal profiles was added to each core admixture after compounding. Multivitamins were added just before the 24-hour room-temperature (25 +/- 4 degrees C) storage. Admixtures were tested initially and after one day at room temperature or nine days at 5 degrees C plus one day at room-temperature storage. Measurements of pH, emulsion particle size, osmolality, and zeta potential (electrostatic surface charge of lipid particles) were made after visual inspection of each admixture. In general, the TNAs retained a uniform, milk-like appearance under both storage conditions. The values of pH, zeta potential, particle size, and osmolality remained essentially unchanged throughout the study. Under the conditions of this study, the TNA formulations tested are stable for up to 10 days.

Stability of Liposyn II fat emulsion in total nutrient admixtures.

Compatibility and safety of a safflower oil-soybean oil lipid emulsion (Liposyn II, Abbott) with amino acids and dextrose in total nutrient admixtures (TNAs) were studied. Sixty-two admixtures representing 31 different combinations of fat emulsion, amino acid injection, and dextrose injection were tested. Both 10% and 20% concentrations of the fat emulsion and three concentrations each of amino acid injection and dextrose injection were used; the core admixture components were placed in empty flexible plastic bags in three different sequences: fat, amino acids, dextrose; fat, then dextrose and amino acids simultaneously; and amino acids and dextrose simultaneously, then fat. One of two mixtures of electrolytes and trace metals was added to each sample at the end of mixing. Six samples were tested after one day at 25 degrees C, 35 after two days at 5 degrees C plus one day at 30 degrees C, and 21 after nine days at 5 degrees C plus one day at 25 degrees C. Multivitamin injections were added to each TNA just before the 24-hour room-temperature storage. pH, emulsion particle size, and zeta potential (electrostatic surface charge of lipid particles) were measured after visual inspection of each sample. Amino acids were separated by high-performance liquid chromatography and measured. Dextrose was measured by size-exclusion chromatography. In a controlled study of 24 dogs, six-hour infusions of TNAs containing Liposyn II 20% were administered for 14 days, after which all major organs and tissues were studied microscopically. At all storage times in the compatibility study, all TNAs retained a uniform, milk-like appearance.(ABSTRACT TRUNCATED AT 250 WORDS)