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Biomedical subjects

I Thomson

Publications and source records attributed to I Thomson.

30 records · Page 2Linked to original sources
PubMed1980

Determination of cyanide and thiocyanate in biological fluids by gas chromatography-mass spectrometry.

A sensitive, specific and accurate method is described for the determination of cyanide and thiocyanate in biological fluids. Potassium cyanide containing 95% 15N is added to the sample as internal standard and both endogenous cyanide and standard are separated by gas-phase diffusion into sodium hydroxide solution. Cyanogen chloride is prepared by reaction with sodium p-toluenesulphonchloramide and extracted into n-heptane. Quantitative analysis is carried out by gas chromatography-mass spectrometry (GC-MS) with selective ion monitoring of the molecular ions at m/e 61and m/e 62. Thiocyanate levels are determined by a similar procedure in which 15N-labelled sodium thiocyanate is used as internal standard. The method is applicable to a wide range of biological samples and is free from interference by other sample components.

Cyanides↗
PubMed1979

Relationship between crystallin mRNA expression in retina cells and their capacity to re-differentiate into lens cells.

Differentiating vertebrate embryo tissues pass through a stage when they have the potential for several pathways of differentiation, some of them revealed only by experimental manoeuvres. As differentiation proceeds, the potential for alternative pathways becomes progressively restricted and is eventually lost. We have investigated the molecular basis for this phenomenon, using the chick embryo retina, which has a potential for differentiation into lens cells. This potential requires special conditions for its manifestation; it declines during development and is finally lost before hatching. Lens protein (crystallin) mRNA is expressed in early embryo retina: its levels decline in parallel with the decline in lens-forming potential. There is also evidence of an ontogenic change in post-transcriptional regulation. Such a relationship between heterologous mRNA and heterologous differentiation potential may be of general application.

Animals↗
PubMed1978

Cyanide exposure in fires.

The toxic hazard from cyanide produced in fires was assessed in casualties and in firemen exposed to the fire atmosphere. The levels of cyanide and its principal metabolite, thiocyanate, were measured in blood samples from fireman, non-fetal and fatal casualties, and from controls. Although firemen did not differ significantly from controls, casualities showed significant elevation of blood-cyanide, and in a small proportion of fatalities blood-cyanide reached toxic levels.

Cyanides↗