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Biomedical subjects

C Dawes

Publications and source records attributed to C Dawes.

At least 91 records · Page 5Linked to original sources
PubMed1978

Automated tests for the assessment of thyroid function.

Fully automated methods have been developed for the determination of thyroxine and triiodothyronine levels, antibodies to thyroglobulin and the assessment of thyroid hormone binding proteins in serum, using a continuous flow radioimmunoassay system. In addition the feasibility of a partially automated assay for thyrotrophin levels has been demonstrated. These employ Auto Analyzer modules and antibodies covalently linked to a magnetisable solid phase support. Separation of bound and free antigen is achieved by applying an external magnetic field. The system currently operates at a rate of 30 samples/h and requires only 10 minutes incubation since it is not necessary to reach equilibrium. The results are similar to those obtained by conventional manual techniques, however the precision is improved and operator error eliminated.

Female↗
PubMed1976

Testosterone in human saliva.

Testosterone has been detected in whole human saliva. Levels averaged (+/- SE) 295 +/- 36 and 195 +/- 25 pg/ml in adult males and females, respectively, and usually were undetectable in children. In adult males, the excretion of testosterone in saliva appeared to follow a circadian rhythm.

Adult↗
PubMed1975

Circadian rhythms in the flow rate and composition of unstimulated and stimulated human submandibular saliva.

1. Nine subjects recorded oral temperature and collected unstimulated submandibular saliva and submandibular saliva stimulated by sour lemon drops at a constant flow rate of 1 ml./min, at about 07.00, 11.00, 14.00, 17.00 and 22.00 h daily for time spans of about 11 days. 2. Least-squares cosine waves were fitted to the data to test for the presence and characteristics of circadian rhythms and the results were subjected to cosinor analysis and the Rayleigh test to assess the statistical significance of any rhythms for the group of subjects as a whole (i.e. whether or not the computed acrophases were randomly distributed throughout the 24 h of the day). 3. Unstimulated submandibular saliva showed circadian rhythms, significant for the group as a whole, in flow rate and in the concentrations of sodium, potassium, magnesium, chloride and inorganic phosphate but not in protein or calcium. 4. Stimulated submandibular saliva showed circadian rhythms, significant for the group as a whole, in sodium, potassium, calcium, magnesium, chloride and inorganic phosphate but not in protein. Oral temperature also showed a significant circadian rhythm. 5. Because of the high amplitude of many of these rhythms, they must be taken into account when establishing the normal range of salivary values, or when salivary composition is to be used as an indicator of systemic disease or to be implicated in the aetiology of oral disease.

Adult↗
PubMed1972

Circadian rhythms in human salivary flow rate and composition.

1. Unstimulated whole saliva and parotid saliva stimulated at a constant flow rate of 1.0 ml./min were collected from eight subjects at about 07.00, 11.00, 14.00, 17.00 and 22.00 hr and oral temperature was recorded several times daily for time spans of between 4 and 26 days. A least-squares cosine wave was fitted to the data to test for the presence and characteristics of circadian rhythms.2. Estimates of mean level, amplitude, acrophase and period were obtained for different components and the results were subjected to cosinor analysis.3. Unstimulated whole saliva showed significant circadian rhythms in flow rate and in the concentrations of sodium and chloride but not in protein, potassium, calcium, phosphate or urea.4. Stimulated parotid saliva showed significant circadian rhythms in the concentrations of protein, sodium, potassium, calcium and chloride but not in phosphate or urea5. Oral temperature showed a circadian rhythm which, like the salivary rhythms, was of a 24.0 hr periodicity.

Adult↗