Target-specific requirements for RNA interference can arise through restricted RNA amplification despite the lack of specialized pathways.

Since double-stranded RNA (dsRNA) is effective for silencing a wide variety of genes, all genes are typically considered equivalent targets for such RNA interference (RNAi). Yet, loss of some regulators of RNAi in the nematode can selectively impair the silencing of some genes. Here, we show that such selective requirements can be explained by an intersecting network of regulators acting on genes with differences in their RNA metabolism.

Target-specific requirements for RNA interference can arise through restricted RNA amplification despite the lack of specialized pathways.

Since double-stranded RNA (dsRNA) is effective for silencing a wide variety of genes, all genes are typically considered equivalent targets for such RNA interference (RNAi). Yet, loss of some regulators of RNAi in the nematode can selectively impair the silencing of some genes. Here we show that such selective requirements can be explained by an intersecting network of regulators acting on genes with differences in their RNA metabolism.

Stability of cefonicid sodium in infusion fluids.

The chemical stability of cefonicid sodium in infusion fluids was analyzed. Cefonicid sodium vials were reconstituted and diluted with sterile water for injection and other commonly used intravenous fluids to concentrations of 325, 220, 40, 20, and 5 mg/mL. Cefonicid concentration was analyzed by high-performance liquid chromatography initially and after storage at room temperature and 5 degrees C.

A dissolution anomaly involving ticrynafen in simulated intestinal fluid without enzyme.

Data are presented showing that the anomalous dissolution behavior of ticrynafen in simulated intestinal fluid without enzyme is due to the presence of potassium ions in the dissolution medium. Solubility studies indicate that an insoluble 1:1 complex is formed between ticrynafen and its potassium salt. This complex apparently creates an insoluble barrier that prevents complete dissolution of ticrynafen.

Degradation kinetics of a new cephalosporin derivative in aqueous solution.

The degradation kinetics of a new cephalosporin derivative (1) in aqueous solution were investigated at 60 degrees, mu = 0.05, at pH 2.0-10.

Blindness due to illicit use of topical cocaine.

A drug abuser developed simultaneous bilateral corneal ulcerations after the use of topical cocaine. One eye was enucleated because of secondary angle-closure glaucoma and the other developed a dense central corneal scar.

Degradative behavior of a new bronchodilator, carbuterol, in aqueous solution.

The degradation kinetics of carbuterol in aqueous solution were investigated at 85 degrees and constant ionic strength over the pH 0.25--13.3 range under anaerobic conditions.

Kinetics of degradation of cefazolin and cephalexin in aqueous solution.

The kinetics of degradation of cefazolin and cephalexin in aqueous solution were investigated at 60 degrees C and constant ionic strength over the entire pH range. The observed degradation rates were obtained by measuring the residual cephalosporin and were shown to follow pseudo-first-order-kinetics. They were influenced significantly by solvolytic and hydroxide ion catalysis.

Micelle formation and its relationship to solubility behavior of 2-butyl-3-benzofuranyl-4-(2-(diethylamino)ethoxy)-3,5-diiodophenyl ketone hydrochloride.

Micelle formation by 2-butyl-3-benzofuranyl-4-[2-(diethylamino)ethoxy]-3,5-diiodophenyl ketone hydrochloride was studied by conductance measurements. The CMC was approximately 0.05% and was independent of temperature between 20 and 50degree.

Pharmacokinetic interpretation of blood levels and urinary excretion data for cefazolin and cephalothin after intravenous and intramuscular administration in humans.

Blood levels of cefazolin and cephalothin were determined in two separate crossover studies in 20 healthy male adults, each after intravenous and intramuscular administration. Pharmacokinetic parameters were calculated from the intravenous data based upon a two-compartment open model. The rate constants controlling the distribution between the central and peripheral compartments, the overall elimination rate constants, the apparent volumes of distribution, and the fraction of the dose in the central and peripheral compartments were determined.

Cholesterol solubility in lecithin-bile salt systems.

The method of sample preparation can markedly influence the rate of dissolution and attainment of supersaturated states of cholesterol. The equilibrium solubility of cholesterol, studied as a function of its physical state in a model bile system, is almost half that of previously accepted values. Slow attainment of the equilibrium state may have acted to bias previous studies.