Princy Merlin Johnson

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1. Aplysia californica incorporates toxins and pigments from its red seaweed diet into its body and ink, purportedly as a defense against predation. We tested ink's potential defensive function by assessing the survival of green seaweed-fed (red algal toxin deprived) snails in encounters with a natural predator, the sea anemone Anthopleura xanthogrammica.(More)
We describe a rapid quantitative and qualitative "high-performance" liquid-chromatographic (HPLC) method for measuring porphyrins in urine. Direct injection of acidified, filtered urine onto a 3-micron (particle size) 3-cm-long reversed-phase column fully resolves uroporphyrin, hepta-, hexa-, and pentacarboxylic acid porphyrins, and coproporphyrin.(More)
We report the effect of sample matrix and pH on quantification of porphyrins by HPLC with fluorimetric detection. For aqueous solutions of pH less than 2.5, HPLC peak heights of the porphyrins increased with decreasing pH, reaching a plateau at pH less than 1.0. This loss of porphyrins from solutions with pH greater than 1.0 appeared to be due to a(More)
Good clinical control of hypertension is achieved with low doses of the potent beta-blocker bopindolol. Pharmacokinetic evaluations therefore require an analytical technique of high sensitivity. Analysis of plasma by high-performance liquid chromatography (HPLC) using electrochemical detection provides this sensitivity. This article describes the(More)
Quinones are molecules with varied biological activities and electronic properties which are used for important applications [1, 2]. Quinone with a heteroatom substituted, namely 2-chloro-3-ethylamino-1,4-naphthoquinone (N-CAN) was synthesized and characterized by various techniques such as H1-NMR, C13-NMR, Mass spectroscopy and FT-IR spectroscopy. In this(More)
The preparation and use of a new haemagglutination assay for rheumatoid factor using preserved erythrocytes covalently coated with human IgG is described. Test serum heat inactivation or adsorption with uncoated erythrocytes is not required. This human IgG-coated erythrocyte agglutination test (H/CEAT) appears stable and specific, is suitable for routine(More)
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