In a previous paper of this series (1) we have shown that while the dilution curve for cod liver oil with antimony trichloride is not a linear function, a comparison can be made between the colorimetric assay of vitamin A in certain fish oils, with a chloroform solution of antimony trichloride, and the biological assay upon the same oils, when certain precautions are taken. In a second paper (2...

We describe a new indicator dilution method of measuring cardiac output in man. A bolus injection of lithium chloride 0.6 mmol was given via a central venous catheter and arterial plasma [Li+] recorded using a specially developed sensor incorporating an Li(+)-selective electrode. Cardiac output was derived from the lithium dilution curve, with a correction for packed cell volume. Lithium diluti...

Minimum inhibitory concentrations, minimum bactericidal concentrations, and killing curve assays were measured after Legionella pneumophila was grown in human lung fibroblasts. Results of susceptibility testing of organisms grown intracellularly are compared with results for organisms grown by standard tube dilution methods.

A modification of the method for radioimmunoassayof insulin is described, which achievessatisfactory sensitivity while employing commercially available reagents and antiserums. These modifications consist mainly in lowering the initial percentage binding, reducing the amount of labeled insulin, and preincubating the unlabeled hormone with antiserum. Application of the linear isotope dilution fo...

The in vitro activity of ceftriaxone alone and in combination with gentamicin, tobramycin, and amikacin against 50 Pseudomonas aeruginosa strains was studied by the broth dilution method and the time-kill curve method. The majority of the P. aeruginosa strains tested were resistant to ceftriaxone. Combining ceftriaxone with the aminoglycosides resulted in synergism, antagonism, or indifference.

• The importance of ventricular volume as one of the determinants of stroke output has led to the development of methods for measuring ventricular volumes in vivo, using either radiographic techniques" or applications of the indicator-dilution principle."TM The latter method requires the rapid injection of an indicator into the ventricle and registration of the resultant time-concentration curv...

One of the cores flax (Linum usitatissimum L.) production is to precisely measure requirement phosphorus (P) fertilization for optimizing seed yield, grower profits, P-use efficiency, and reducing environmental risk. Therefore, critical P concentration (Pc) was proposed as a suitable analytical tool assess nutrition status. Four field experiments, with five applications (0, 40, 80, 120, 160 kg ...