There have been numerous studies on the distribution of endogenous histamine (1-5). Many mammalian tissues contain large to small amounts of histamine preformed. Amongst them skin, stomach and lung contain extremely high concentration of histamine. These organs are exposed to the outside directly or indirectly and prone to traumatic injury. The tissue level of histamine has been estimated with ...

The elements of the mechanized fluorometric lipase (EC 3.1.1.3) assay of Fleisher and Schwartz [Clin. Chem. 17, 417 (1971)] were made optimum; a manual adaptation was also developed. Hydrolysis of the monodecanoyl fluorescein substrate by hog pancreatic lipase is a zero-order reaction. The hydrolytic activity of normal human serum, serum from hospitalized patients without pancreatitis, and seru...

We adapted the method of McCaman and Robins for fluorometry of phenylalanine to a microplate assay for routine phenylketonuria screening. Sensitivity is 15 mumol/L for the plasma assay and 30 mumol/L for the dried blood-spot assay, with CV less than 10% for both assays. Results for human plasma by microplate assay correlated well (r = 0.99) with results of amino acid analyzer determination of p...

A novel fluorometric method was developed and validated for hydroxyl radical scavenging capacity (HOSC) estimation using fluorescein as the probe. A constant flux of pure hydroxyl radical is generated under physiological pH using a Fenton-like Fe3+/H2O2 reaction. The generation of pure hydroxyl radicals under the experimental conditions was evaluated and confirmed using electron spin resonance ...

In this study, we compared three methods for extraction and quantification of RNA and DNA from marine sediments: (i) a spectrophotometric method using the diphenylamine assay; (ii) a fluorometric method utilizing selective fluorochromes (thiazole orange for total nucleic acids and Hoechst 33258 for DNA); and (iii) a high-pressure liquid chromatography (HPLC) method which uses a specific column ...