Ivor Smith

Separation of human tissue alkaline phosphatases by electrophoresis on acrylamide disc gels.

Abstract A new procedure for the separation of alkaline phosphatases using a continuous tris-borate buffer on a 5% acrylamide gel, is described. The method is used to differentiate enzyme patterns obtained from liver, bone, kidney, intestine and other tissues before and after neuraminidase treatment.

A gas chromatography-mass spectrometry method for the quantitative analysis of melatonin in plasma and cerebrospinal fluid.

Abstract A method has been developed for the quantitative analysis of melatonin in human plasma and cerebrospinal fluid. The technique involves a simple one-step extraction with chloroform and conversion of the melatonin in the extract to its N-trimethylsilyl derivative, which is then measured by means of high-sensitivity gas chromatography—mass spectrometry. Intra-assay precision for triplicate samples at the 20-pg/ml level was better than 20%, while the interassay precision for separate determinations made over the course of a week was better than 18%. In a series of human plasma samples taken over several times during a 24-hr period, a significant increase in melatonin level was noted during the hours of darkness.

A Clinical and Biochemical Correlation Between Tyramine Andmigraine Headache

THE FACT THAT certain articles of food can precipitate attacks of migraine in sufferers who link some of their headaches with dietary factors has been established.1,2,3 Dietary migraine is best described as attacks of migraine which are precipitated by the ingestion of certain foods, and the sufferers usually learn to exclude these foods from their diet independently of medical advice. The foods most commonly implicated are shown in the first table (See Table 1).

Human fetal corticotrophin and related pituitary peptides.

Abstract In an attempt to distinguish a family of closely related pituitary peptides, human fetal and adult pituitaries were extracted, chromatographed and the fractions subjected to at least 3 systems of radioimmunoassay. From the 12th week to the 38th week of gestation the dominant peptides of the human fetal pituitary were found to resemble corticotrophin-like intermidiate lobe peptide (CLIP) and α-MSH rather than ACTH. At term the profile was reversed and ACTH became the dominant peptide. It was not possible to investigate these findings in plasma. We advance the hypothesis that it is CLIP or α-MSH which will prove to be the trophic hormone for the fetal zone of the adrenal cortex and suggest that the switch of peptide synthesis in the human fetal pituitary at term is functionally related to the metamorphosis of the human fetal adrenal gland.

Isoelectric focusing of alkaline phosphatases. A focusing-disc electrophoresis transfer technique.

Abstract An isoelectric focusing technique for the separation of alkaline phosphatases on acrylamide gels is described. Subsequently enzyme-gel slices can be removed and run on standard analytical disc gels to correlate bands and confirm identities; alternatively disc gel slices can be removed and run on focusing gels. This transfer technique should be of wide application in enzyme electrophoresis.

Pineal 5-methoxy tryptophol in man

Abstract (1) The substance 5-methoxy tryptophol, one of a family of 5-methoxy indoles produced by the pineal gland, like melatonin, is capable of modifying sexual development and reproduction in animals and reportedly suppresses the pituitary-adrenal axis under resting conditions. (2) It is present in human plasma throughout the 24 hr and peaks of activity occur both in the day and during the hours of darkness. (3) The plasma levels of 5-methoxy tryptophol show major variations with the menstrual cycle and highest values were found in the first 9 days of the cycle dropping to a nadir in the final third of the cycle. (4) The stress of hypoglycemia produced a dramatic drop in the circulating levels of 5-methoxy tryptophol which recovered as the blood glucose returned to normal. (5) The preliminary findings presented here are insufficient to support any firm conclusions about the role of 5-methoxy tryptophol in man and the possibility exists that it is an inactive metabolite rather than a functionally significant pineal hormone.

Seeing gel wells well

Indicator dyes have been incorporated in the stacking gel monomer used in acrylamide gels to render readily visible and delineate the sample wells. Some dyes, such as bromphenol blue, migrate during the electrophoresis, whereas others, such as the ortho-unsubstituted phenol red, become chemically bound to the polymerized gel. The method can be used for agarose gels.

Use of the spark-chamber radio-scanner for rapid location and quantitation of labelled compounds after one- and two-way separations

Abstract A rapid method of scanning two-way radio-chromatographic and electrophoretic separations is described. The scanner produces a photograph in approximately 10 min, which is adequate for almost all uses and compares well with the usual 4- to 20-week X-ray film method. The technique is illustrated with examples from tyramine metabolism.

A simple and rapid method for the detection and identification of mycobacteria using mycobactin

A system was developed for the identification of mycobacteria such as Mycobacterium tuberculosis and M. avium, by thin layer chromatography of 55Fe-labelled mycobactin. Approximately 2 x 10(3) mycobacteria were detected within 24 h and little operator time or skill was required. M. avium, M. intracellulare and M. scrofulaceum were found to have lower requirements for iron than other mycobacteria and this may influence their growth in host organisms.

The estimation of true urinary tyramine in man

Abstract A method involving solvent extractions and chromatographic separation is described which permits the measurement of true free and conjugated tyramine in urine.