A study of the effect of graded immunizing doses of typhoid vaccine and graded challenge doses of S. typhosa in 5 per cent mucin on the degree of gradation of response (survival or death) elicited in successive groups of mice is reported. In the range of doses employed the effect of graded immunizing doses was markedly greater than was the effect of graded challenge doses. Statistically the dif...

Cytotoxic potencies of cyclophosphamide, 4-ketocyclophosphamide, carboxyphosphamide, mechlorethamine (HN2), bis(2-chloroethyl)amine (nor-HN2), chlorambucil, acrolein, and cyclophosphamide metabolites generated in vivo and in vitro were determined via bioassay. Our bioassay procedure was to incubate the potential cytotoxic agent with Walker 256 ascites cells in vitro, inject these cells into hos...

Both isoproterenol and tidal fluctuations of muscle length inhibit active force development in activated airway smooth muscle. In this study, we show that length fluctuations in the range of amplitudes expected during quiet tidal breathing produce force inhibition that is equipotent with high concentrations of isoproterenol. Active force fell to 50% of its isometric value when the amplitude of ...

Q uestion: What is the relative per microgram potency and side effect profile of the 8-agonists salbutamol and fenoterol? Method: The relative bronchodilator ( FEV1, V25, V50) potency and side effect profile ( tremor, heart rate, breathlessness, BP) of nebulized salbutamol and fenoterol were evaluated by means of a randomized, doubleblind, crossover, cumulative (50 to 2,500 g) doseresponse stud...

The chemically activated luciferase expression (CALUX) system is a mechanistically based recombinant luciferase reporter gene cell bioassay used in combination with chemical extraction and clean-up methods for the detection and relative quantitation of 2,3,7,8-tetrachlorodibenzo-p-dioxin and related dioxin-like halogenated aromatic hydrocarbons in a wide variety of sample matrices. While sample...

The protein-based secondary standardsfor serum fructosamine in a commercial test kit (Roche Diagnostics) have recently been modified by the manufacturer. Under certain assay conditions, the new calibrator gave significantly greater serum fructosamine values than those obtained with the originally supplied calibrator. However, for 20-4, samples and absorbance measurements at 10 and 15 mm, hereaf...

Since the initial development of the "passage A" mouse leukemia virus in 1957, this virus has been propagated in our laboratory by serial passage in newborn C3H(f) mice. At the present time, 10(-2)-10(-3) dilutions in physiological saline solution of this mouse-passaged virus induce lymphatic leukemia in practically all inoculated mice after a latency of 3-5 months. On the other hand, when the ...

The in vivo effects of xenoestrogens are of interest in relation to their potential health risks and/or beneficial effects on humans and animals. However, the apparent in vivo potency of the examined response can be confounded by a short half-life, and the metabolism of estrogens is very dependent on the nature of conversion and/or inactivation. To minimize such variables, we examined the estro...

Tyrosol (Tyr) is a natural phenolic antioxidant with diverse biological activities. We compared the anti-inflammatory effects of intravenously administered Tyr versus prednisolone (PSL) in an endotoxin-induced uveitis (EIU) rat model. Intravenous administration of 100 mg/kg Tyr was performed 2 hr before, simultaneously and 2 hr after lipopolysaccharide (LPS) injection. Tyr treatment was associa...