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Biomedical subjects

G Chabrier

Publications and source records attributed to G Chabrier.

58 records · Page 4Linked to original sources
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[Ultrasensitive determination of thyrotropin. Improvement in the performance and reduction of the cost of thyroid function tests].

The characteristics of an ultrasensitive thyrotropin (TSH) assay method using monoclonal antibodies (TSH-U) were determined in euthyroid subjects, either healthy or with extra-thyroid disease, in treated and untreated hyper-and hypothyroid subjects and in subjects under amiodarone. The thyroid function was evaluated by free thyroxine (FT4) and free triiodothyronine (FT3) assays and by TSH tests and TSH response to TRH. With a sensitivity of 1 and a specificity of 0.94, the TSH-U assay proved highly reliable to evaluate the thyroid function. Dysthyroidism can be excluded when TSH-U levels are normal (0.15 to 4.5 microU/ml). In case of low TSH-U level, measurements of FT4 and FT3 and, if required, thyroid gland scintigraphy are necessary to confirm a diagnosis of hyperthyroidism. In contrast, a high TSH-U level is sufficient for affirm diagnosis of hypothyroidism. The TSH-U assay makes the TRH test redundant and can differentiate between hyperthyroxinaemia with euthyroidism and with hyperthyroidism. It is an effective method to detect disorders in thyroid function and it calls for a re-evaluation of thyroid diagnostic strategy.

Adult↗
PubMedDate not supplied

[Clinical and biological patterns of hyperthyroidism in elderly patients (author's transl)].

Aetiological, clinical and biological patterns of hyperthyroidism are studied in 22 consecutive patients over the age of 65 years. In this group the frequency of toxic multinodular goiter and Graves disease are grossly the same. A previous iodine administration could be a significant aetiologic factor in 8/22 patients. The clinical symptomatology is characterized by the predominance of cardiovascular disorders and by the mildness or absence of the other symptoms of thyrotoxicosis. The classical abnormalities of thyroid function tests are only found in 65% of our patients. The others have high total and free thyroxine (T4) and normal triiodothyronine (T3) plasma levels with a marked increase in reverse T3 (RT3) levels. These abnormalities result possibly from an impairment of the peripheral conversion of T4 to T3 as it is seen in fasting or in sick euthyroid patients. Most of our hyperthyroid patients had an associated disease and were undernourished. In the elderly patient the determination of plasma T4 by a radioimmunoassay and the T3 uptake test are the best screening methods for detecting an often hidden thyrotoxicosis.

Aged↗
PubMedDate not supplied

[Renal origin of hyperammonemia induced by an high-protein diet in normal rats or those with portal stricture].

Hyperammonemia is observed in high protein diet fed cirrhotic and is thought to be related to an increased intestinal ammoniagenesis. We studied this problem in control rats and rats with a portal stricture and portal systemic shunts given a high protein or a standard diet. In those animals the systemic, portal and renal venous ammonemia and glutaminemia were measured. In rats with portal stricture on a high protein diet, the increase in systemic ammonemia did not significantly differ from that found in animals on a standard diet. In contrast, the control group exhibited a higher level (P less than 0.001) of systemic ammonemia after a high protein (102 +/- 7 SEM mumol/l) than after standard diet (36 +/- 1). This hyperammonemia appeared to be of renal origin since there was a significantly higher ammonia difference between renal venous and arterial blood with the high protein than with standard feeding, both in rats with a portal stricture (+ 229 +/- 32 vs. + 24 +/- 8 mumol/l; P less than 0.001). and in control rats (+ 196 +/- 23 vs. + 2 +/- 11; P less than 0.001). This increased renal ammonia release into the circulation induced by the high protein diet was associated with a high renal uptake of circulating glutamine. Moreover, a decreased ammonia passage from the digestive tract into the portal vein and disappearance of intestinal uptake of circulating glutamine was also observed with the high protein feeding.(ABSTRACT TRUNCATED AT 250 WORDS)

Ammonia↗