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Biomedical subjects

C Demangeat

Publications and source records attributed to C Demangeat.

30 records · Page 2Linked to original sources
PubMed1985

[Plasma and synovial beta-2-microglobulin. Results of a personal study].

Beta-2-microglobulin was assayed in the plasma and the synovial fluid in 41 subjects with mechanical joint disorders, 27 patients with rheumatoid arthritis and 32 patients with non-rheumatoid arthritis. The plasma beta-2-microglobulin may be raised in all forms of joint disease, especially in the course of rheumatoid arthritis, but its ability to discriminate between rheumatoid arthritis and other forms of inflammatory joint disease is poor. In contrast, for the beta-2-microglobulin level in the synovial fluid, the differences in the means are highly significant between rheumatoid arthritis and non-rheumatoid arthritis. Concentrations of beta-2-microglobulin in the synovial fluid greater than 5.2 micrograms/ml, in this study which excluded patients with renal failure, were 100 per cent specific for rheumatoid arthritis and were found in 52 per cent of cases. However, this result has to be interpreted in the light of the fact that any extra-articular cause for an increased plasma beta-2-microglobulin, particularly renal failure, also causes a rise in the synovial concentration, invalidating the test. For this reason, the authors propose using the value of the beta-2-microglobulin in the synovial fluid minus the plasma beta-2-microglobulin, as a more specific index.

Arthritis↗
PubMed1984

The role of insulin, glucagon and growth hormone in the regulation of plasma glucose and free fatty acid levels in anorexia nervosa.

It is well established that glucagon plays an important role in the regulation of fuel supplies as its plasma level increases during the first days of a complete fast. However, it is not certain that glucagon is involved in the adaptation to chronic starvation. In the present study, this problem was investigated by the determination of the changes in the plasma glucagon level elicited by an i.v. glucose tolerance test followed by an i.v. arginine perfusion in 26 self starved patients suffering from anorexia nervosa (AN) and 14 control patients having only minor neurotic disorders. The basal plasma glucagon level tended to be higher in the AN patients than in the controls; but the difference was not statistically significant. Glucagon responses to glucose and arginine observed in the AN patients were not significantly different from those seen in the control patients. In the AN patients, the insulin response to both loads was reduced and the plasma GH level increased paradoxically after the glucose load, whereas it rose normally after the arginine load. It may be concluded that in chronic starvation by AN the regulation of fuel supplies depends mainly on decreased insulin and increased growth hormone secretion. The role of glucagon seems to be of minor importance in this condition.

Adolescent↗
PubMed1983

[Quantitative evaluation of hormonal extraction performed by continuous plasma exchange in euthyroid patients. Application to the treatment of severe hyperthyroidism].

Plasma exchanges (PE) have been successfully used in the treatment of thyroid storm. The dramatic results obtained (as in the case reported here) have prompted the authors to evaluate the effects of PE on plasma thyroid hormone (T4, T3 and unbound T4) levels and thyroxine-binding globulin (TBG) levels in 5 euthyroid patients. PE of one blood volume consistently produced a significant decrease in T4, T3 and TBG levels without changes in unbound T4 or TSH. Hormone extraction was proportional to the volume of blood removed and correlated with the amount of TBG extracted. Compared with the estimated total plasma content, the percentage of unbound T4 extracted was superior to that of total T4, which suggests release of free hormones from the intracellular compartment. Repeated PE in the same patient resulted in a transient decrease in T4 without changes in TSH. These results indicate that PE constitutes a fast, simple and effective means of removing thyroid hormones in all emergencies related to thyrotoxicosis. The fact that TSH levels remain stable after PE shows that the thyroid balance in euthyroid subjects is unaffected by this method.

Evaluation Studies as Topic↗
PubMed1983

[Asymptomatic thyroid dysfunction. Routine detection using the free thyroxine index].

Free plasma thyroxine index (FT4I) and plasma concentrations of triiodothyronine (T3) were routinely determined on admission in 1862 hospital patients without signs or history of thyroid dysfunction. Total thyroxine (T4) and FT4I values were beyond confidence limits in 16.3% and 7.5% respectively of the patients, whereas T3 values were low in 23%. Among the 84 patients with high FT4I, 31 had clinically unsuspected hyperthyroidism confirmed by the TRH test (T3 increased in 66% of the cases). Among the 46 patients with low FT4I, 14 had demonstrable hypothyroidism (low T3 in 65% of the cases). In this population, the prevalence of proven thyroid dysfunction without clinical symptoms was 1.66% for hyperthyroidism and 0.75% for hypothyroidism. The diagnostic value of normal FT4I was estimated at 50%. The persistence of an abnormal FT4I on a second determination indicated the presence of hyperthyroidism in 72% of patients with high FT4I values and of hypothyroidism in 74% of patients with low FT4I values. In doubtful cases, TSH assays or TRH tests led to the concept of "transient" dysthyroidism, and the potential total prevalence of routinely discovered dysthyroidism could be estimated at 3.54% including 2.47% for hyperthyroidism. The latter occurred in 95% of people older than 50, with a sex ratio of 0.94. The cost of diagnosis for each new case clinically unsuspected hyperthyroidism is 1200 Z, but this could be reduced to 450 Z if only patients over 50 years of age were investigated and if FT4I determinations were replaced by free T4 determinations.

Adult↗
PubMed1982

Consequences of the chronic cutaneous application of iodinated antiseptics on the thyroid function in the guinea-pig.

The effect of the chronic cutaneous application of iodine-containing substances on the thyroid function was studied in the guinea-pig. Six iodinated products were daily applied at the rate of 2 g/kg/day for 90 days. We find a quasi-abolition in the thyroid 131I-uptake (reflecting the transcutaneous absorption of free iodine) and an important transient thyroidal hyperproduction during the first month. Then, this primary hyperthyroidism induces a strong pituitary negative feed-back so that the levels of the circulating hormones T3 and T4 are normalized at the end of the experiment; a new hormonal balance is reached with a TSH level reduced by half compared to its normal value.

Animals↗
PubMed1982

[Renin-angiotensin-aldosterone system in obese children].

Plasma renin (PRA) and aldosterone activities were measured in 29 obese children and in 48 controls of the same age. Blood samples were taken at 8 AM after a night's sleep and after 3 days of a diet with normal sodium intake. The PRA in the obese children was lowered: m = 1.00 ng/ml/h (controls = 1.86 ng/ml/h; p = 0.01). The drop in plasma aldosterone activity was not significant: m = 134.1 pg/ml (controls: m = 167.5 pg/ml). Plasma aldosterone activity was positively correlated with PRA in controls (p less than 0.01): this correlation was not found in obese children. In obese children no dissociation could be found, in the resting state, between plasma aldosterone activity and PRA, contrary to obese adults under stimulation. In fact, 1) the aldosterone/PRA ratio did not differ significantly between obese children and controls, 2) the average value of plasma aldosterone activity that one could predict in the obese children from their average PRA level and the linear regression calculated from the controls exactly corresponded to the measured value. The elevated blood pressure found in the obese children could explain the drop in the PRA which would thus remain adapted to the blood pressure level.

Adolescent↗
PubMed1981

[A study of thyroid function in patients with psychoaffective disease (author's transl)].

The purpose of the present study was to investigate dysfunctions in thyroid gland secretion and regulation among patients with manic-depressive psychosis. Plasma levels of thyroxine (T4), triiodothyronine (T3) and thyroid stimulating hormone (TSH) were measured by radioimmune assays, and TSH responsiveness (delta TSH) to synthetic TSH-releasing hormone (TRH) 250 microgram IV was determined in 20 untreated patients, 19 patients under neuroleptics and 19 patients under antidepressants. Untreated patients were compared with 15 age - and sex-matched controls. They were found to have significantly lower plasma T3 levels than controls (121.0 +/- 6.0 ng/dl as against 144.5 +/- 3.3 ng/dl; p less than 0.01) and blunted TSH response to TRH (delta TSH 4.1 +/- 0.6 instead of 12.6 +/- 2.1). Other thyroid function parameters were unchanged. Under neuroleptic treatment T3 levels tended to increase and delta TSH returned to normal. Manic-depressive psychosis is characterized by hypothalamic-pituitary dysfunction. Thyroid secretion is normal, and the decrease in T3 is probably due to impaired peripheral T4 to T3 conversion.

Bipolar Disorder↗
PubMed1978

[Insulin secretion in alcoholic hepatopathy: analysis by measurement of C-peptide (author's transl)].

Basal and reactive peripheral hyperinsulinism recorded in alcoholic hepatic disease may result from decreased hepatic breakdown or pancreatic hypersecretion. C-peptide (CPR) and insulin (IRI) concentrations were measured in 3 groups of 8 alcoholic patients--steatosis, compensated and decompensated cirrhosis--and compared with 8 normal subjects in order to determine the importance of these two possibilities. At basal state, the molar ratio CPR/IRI was near the normal (8.7 +/- 0.9) but is diminished in the 8 hyperinsulinaemic patients (5.9 +/- 0.6). After i.v. glucose tolerance test and tolbutamide stimulations, an hyperreactivity of IRI and CPR may be noted in cirrhotics. A relative insensitivity of the B-cell to glucose appeared after comparison with the effect of tolbutamide. Thus basal hyperinsulinism resulted of decreased hepatic breakdown and stimulated hyperinsulinism resulted of hypersecretion. Glucose intolerance and anomalies of the insulin secretion were more apparent with severe hepatic disease.

Adolescent↗
PubMedDate not supplied

[Simultaneous determination of blood insulin and plasma C-peptide levels. Value during assessment of glucose tolerance, especially in obese subjects (author's transl)].

Insulin secretion is assessed by simultaneous radioimmunological assay of insulin (R.I.I.) and C-peptide (R.I.C.P.) levels under basal conditions, and after stimulation by oral or intravenous glucose administration. Subjects with abnormal glucose tolerance demonstrate an increase in the ratios R.I.C.P. divided by glucose and R.I.C.P. divided by R.I.I. after fasting, increase in R.I.I. and R.I.C.P. occurring later and lasting longer after glucose loading. These anomalies are observed in both obese subjects and those with normal body weights. Simultaneous determination of R.I.I. and R.I.C.P. levels appears of value in a limited number of cases where glucose loading tests do not supply precise information on the quality of glucose tolerance. Obese subjects, in whom abnormal hyperglycemia levels provoked by oral glucose are observed, but in whom the peripheral glucose assimilation coefficient is normal, can be considered to be non-diabetic as shown by the levels of R.I.I. and R.I.C.P. and more particularly by the molar ratio R.I.C.P. divided by R.I.I.

Administration, Oral↗
PubMedDate not supplied

[Effect of surgery on the level of total and free thyroid hormones, reverse T3 and TSH].

Changes in total and free thyroid hormones, reverse triiodothyronine (rT3) and TSH were followed in 64 patients undergoing surgery and divided into three groups according to nature of surgery. Group I patients underwent extraperitoneal surgery, group II mild and group III heavy intraperitoneal surgery. A significant fall in total and free triiodothyronine (T3), a rise in rT3, free thyroxine (FT4) and in TSH were noted in each group after surgery, while total T4 levels remained unchanged. There was no correlation between the change in thyroid hormones and TSH. These changes are more marked in groups II and III than in group I. The rT3/T3 ratio was more elevated after surgery in group III than in group II. Thus the severity of the stress induced by surgery may interact with the mechanism of peripheral T4 conversion. The rise in FT4 may be interpreted as a consequence of the presence of an inhibitor of thyroid-hormonal binding to serum proteins. The slight increase in TSH levels seems rather due to stress than to a feed-back adaptation. The ratio rT3/T3 appears as an index of severity and prognosis.

Adult↗