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Biomedical subjects

J L Schlienger

Publications and source records attributed to J L Schlienger.

At least 91 records · Page 5Linked to original sources
PubMed1997

[Iodine and thyroid function].

Iodine is a raw material for the thyroid production of hormone which is on the major external control of TSH. The thyroid adaptation to iodine deficiency consists in an increasing iodine concentration from the circulation, an enhancing iodination of the tyrosyl residues in thyroglobulin, a decreasing iodine storage associated to a better recycling of non hormonal iodine and thyroid hyperplasia to provide more synthetic possibilities. Genetic variation and environmental factors explain the wide variation of individuals response to iodine deficiency resulting in a high prevalence of goiter, a mild TSH level increase or overt hypothyroidism. At long term iodine deficiency may have severe pathological consequences and induce neuropsychological deficits in school-children. A policy of iodine supplementation mainly by iodized salt must be undertaken in many areas in the world. Effects of an iodine excess on thyroid function are variable depending upon the underlying thyroid disorder and ambient iodine intake. The most subjects remain euthyroid by mechanisms of autoregulation based on an inhibition of thyroid hormone synthesis and a decrease in the thyroid iodide trap. Euthyroid individuals from high iodine intake areas or those with a history of lymphocytic thyroiditis, treated Graves' disease or subtotal thyroidectomy develop hypothyroidism. On the other hand iodine induced hyperthyroidism is more common in areas of iodine deficiency and in older patients with nodular goiter.

Humans↗
PubMed1997

Two centre evaluation of seven thyrotropin kits using luminescent detection.

We compared seven thyrotropin luminescent immunometric assay kits in two centres, by use of panel sera from 438 patients: controls (n = 203) and different groups of subjects: hyperthyroidism (n = 42), hypothyroidism (n = 46), non-thyroidal illness (n = 102), geriatrics (n = 24) and selected patients previously treated for thyroid cancer and maintained on suppressive doses of L-thyroxine (n = 17), anti-thyrotropin antibody (n = 4). We did not observe any significant differences in analytical tests among the seven methods on the Probioqual control sera, Anemia control serum and human serum pools. The linearity of serial dilutions was found with all kits. Some variations were noticed at extreme dilutions. The within-assay precision was acceptable in all cases. The functional sensitivity limits were estimated from 20% compound precision profile: they ranged from 0.011 to 0.030 mU/l. In the clinical study, the seven assay demonstrated high diagnostic performance. Some interference by heterophilic antibodies were observed.

Aged↗
PubMed1996

[Secretion of thyrotropin during states of wakefulness and sleep. Physiological data and clinical applications].

Rhythmic hormone secretion appears to be a common characteristic of several endocrine systems. Alterations in these secretions are associated with the pathophysiology of certain diseases. Thyrotropin (TSH) exhibits a nocturnal surge in normal subjects. The time and the amplitude of the surge depend on the waking or the sleeping state. The TSH surge is decreased or abolished in various pathological conditions. Assessment of the surge is of particular interest for the early detection of central (pituitary) hypothyroidism, and in the exploration of isolated decreased TSH to predict further evolution toward hyperthyroidism. However, the characterization of the TSH surge needs simplification and standardization before this index could be used for the practical evaluation of thyroid function.

Adrenocortical Hyperfunction↗
PubMed1996

The usefulness of cardio-vascular visualization in the localization of mediastinal pheochromocytomas with I-131-MIBG.

A case of malignant mediastinal paraganglioma showing moderate I-131-MetaIodoBenzylGuanidine (MIBG) uptake in the pericardiac region is presented. The patient had already undergone unilateral adrenalectomy with obvious clinical and biochemical findings of pheochromocytoma. The initial thoraco-abdominal CT and adrenal MRI were negative. The MIBG scan prior to the operation showed moderately increased uptake in the left adrenal region. No pheochromocytoma was found in the removed gland and the clinical signs persisted following the operation. The second MIBG scan after surgery showed a moderate left mediastinal uptake site by which it was difficult to rule out intracardiac localization. Without moving the patient, successive images of the tumor, myocardium and main mediastinal vessels were obtained by using the 24 hour activity of the initially injected 37 MBq Iodine-131-MIBG, 74 MBq Thallium-201 and 555 MBq Tc-99m-Human Serum Albumin (HSA), respectively. The superimposed bicolor images clearly showed the extracardiac localization of the tumor. The MRI scan confirmed this finding. Subsequent surgery found a malignant paraganglioma and metastatic mediastinal lymph nodes. We conclude that the visualization of the myocardium and the main mediastinal vessels with specific agents can be very useful in defining the exact location of I-131-MIBG detected mediastinal pheochromocytomas.

3-Iodobenzylguanidine↗
PubMed1996

[Thyroid function and dysfunction in the elderly].

The consequences of aging function are appreciated in various ways. In fact most of the thyroid hormone abnormalities described in the elderly are secondary to associated disease or treatments. Health and nutritional status seem to be more determinant than age. However, there is an increased prevalence of dysthyroidism in the elderly. Symptoms may be misleading and induce severe general repercussions. Mild or occult forms of dysthyroidism characterized by abnormal TSH levels with normal free thyroid hormone levels are not uncommon. Their clinical significance and their prognosis without treatment are still unresolved. The frequency of dystrhyroidism during old age and the possibility of a specific treatment may be in favour of a screening by a systematic TSH determination in elderly patients.

Aged↗
PubMed1996

Familial dysalbuminemic hyperthyroxinemia and thyroid hormone autoantibodies: interference in current free thyroid hormone assays.

The interference of familial dysalbuminemic hyperthyroxinemia (FDH), antithyroxine (anti-T4) or antitriiodothyronine (anti-T3) antibodies in serum free T4 (FT4) or free T3 (FT3) assays depends on the assay method: two-step immunoextraction, one-step labelled ligand (analogue or derivative tracer) or labelled antibody (solid-phase antigen-linked technique: SPALT) method. For FDH subjects, only FT4 measurements by one two-step method gave reliable results in all cases. However, the overestimation was less marked with new SPALT assays than with previous analogue-based assays. In sera containing anti-T4 antibodies, two-step assays and SPALT assays with a T3-coated solid phase can be considered as reliable for FT4 determination. All other methods including SPALT assays with a T4-coated solid phase may give falsely high results. In sera containing anti-T3 antibodies, SPALT FT4 and FT3 assays with a T3-coated solid phase may give spuriously high values. Anti-T3 antibodies do not interfere in two-step FT3 assays and SPALT FT3 assays with a T2-coated solid phase, but may give high FT3 values as measured by analogue or derivative methods. Moreover, SPALT free thyroid hormone assays may also be subject to interference from antibodies directed towards the assay solid phase.

Autoantibodies↗
PubMed1996

Longitudinal changes in serum lipids of elderly Europeans. SENECA Investigators.

OBJECTIVE: To describe the serum total cholesterol, lipoprotein cholesterol and triglyceride concentrations in elderly people from the SENECA follow-up study and report on longitudinal changes in these lipid concentrations over a four-year follow-up period. DESIGN: Longitudinal study including baseline measurements taken in 1988/1989 which were repeated in 1993. SUBJECTS: In 1993 lipid concentrations were assayed in blood serum collected from 1181 elderly men and women, born from 1913 to 1918 and living in twelve small towns in ten European countries and one town in the USA. 1062 of these subjects had also participated in the baseline study. RESULTS: Mean concentrations ranged from 4.91 to 6.72 mmol/l for total cholesterol, 1.15 to 1.64 mmol/l for HDL cholesterol, 3.04 to 4.47 mmol/l for LDL cholesterol and 1.03 to 1.79 mmol/l for triglycerides. Thirty-two per cent of European men and 18% of women had plasma total cholesterol concentrations below 5.16 mmol/l; 32% of men and 56% of women had HDL cholesterol concentrations exceeding 1.42 mmol/l. Total- and HDL-cholesterol concentrations, and the HDL:total cholesterol ratio were higher in women than in men. Despite large variations between towns no clear north-south gradient was observed. Yet, lowest values for LDL cholesterol tended to be located in the south, while the highest values for LDL cholesterol showed up in the north. Comparisons between the 1989 and 1993 surveys revealed a significant decrease in total cholesterol and an increase in the HDL:total cholesterol ratio without significant variation in HDL cholesterol or triglyceride concentrations. CONCLUSION: Though serum lipid concentrations varied widely across Europe, a marked decline in total cholesterol values along with an increase in the HDL:total cholesterol ratio occurred across the SENECA towns.

Aged↗
PubMed1995

[The cholesterol controversy].

"Leave well enough alone" might be one's conclusion after rereading all the cholesterol lowering trials. We have tried to lower serum cholesterol below 2 g/l in all subjects in order to eliminate the lipid effect in the atherogenesis process. But some metaanalyses have shown that when cholesterol falls below 1.6 g/l overall mortality rises. There is some controversy over these findings but it can be stated that when cholesterol level fall below a certain threshold, it looses its capacity to mark for cardiovascular risk and becomes an interesting indicator of a patent or infraclinical disease state. If we consider the relationship between the whole range of cholesterol levels and risk of morbidity and mortality, the data draw a J curve with a nadir somewhere between 1.8 and 2 g/l. Minimal risk appears to lie between tolerance limits situated at 1.6 and 2.2 g/l. There is no real contradiction between the results of prospective cholesterol lowering trials and the emphasis placed on the danger of cholesterol levels below 1.6 g/l. In fact the objective must be to maintain serum cholesterol at the lowest risk level both in terms of coronary artery disease (as many as 25% of coronary deaths can be prevented according to the most recent metaanalyses) and in terms of overall mortality (cancer, suicide, and even murder). The questions and doubts raised by the tendancy for increased risk on the lower end of the J curve should not change our objective of fighting against hypercholesterolaemia.

Coronary Artery Disease↗
PubMed1995

Relationships between macronutrient intake, handicaps, and cognitive impairments in free living elderly people.

It is still unknown what if any relationships exist between intake of macronutrients by the elderly, and their functional or cognitive handicaps, particularly for free living elderly people. We investigated 226 men and 215 women, aged 65 or more, free living and in good health. They were randomly selected in the département of Bas-Rhin, after stratification for age, sex and residence (rural or urban). Handicaps and cognitive functions of each subject were assessed with the Géronte scale and the Mini-Mental State Examination (MMSE), respectively. Food intake was measured by a three-day record. A multiple correspondence analysis concluded that functional parameters and macronutrient intakes were rather independent. The relationships found were detailed by a backward stepwise logistic regression. In men, alcohol intake was associated with an improvement in functional and cognitive parameters, and polyunsaturated fatty acids with the capacity to move outside the home. In women, lipid intake increased the MMSE score. Overweight in women was linked with better functional and cognitive performances, and in men with the capacity to move outside the home. In both sexes, age worsened the score of functional and cognitive parameters. In conclusion, macronutrient intakes and functional or cognitive parameters were found to be mutually independent; this suggests that macronutrient deficiencies are of little importance in the worsening functional or mental autonomy of the elderly. The relationships found between functional variables and alcohol or polyunsaturated fatty acid intakes in men, and lipid intakes in women, and overweight in both sexes might evidence a better state of health.

Aged↗
PubMed1995

Low cholesterol concentrations in free-living elderly subjects: relations with dietary intake and nutritional status.

Hypocholesterolemia has been reported in epidemiologic studies to be associated with increased mortality from noncardiovascular causes. Low cholesterol concentrations have been reported in various pathologic conditions and in institutionalized elderly patients, and seem to be associated with poor outcome. The role of nutritional factors in the genesis of hypocholesterolemia was investigated in 380 free-living elderly subjects. Subjects in the lowest cholesterol quartile had lower free triidothyronine and prealbumin concentrations and a lower Folstein's score (a minimental test) than did those in the other quartiles. They did not differ from the other subjects for energy or nutrient intakes. Only 12 subjects (9 men and 3 women) had cholesterol concentrations < 3.62 mmol/L: the men had low free triidothyronine, free thyroxine, and prealbumin concentrations but normal energy and nutrient intakes, whereas the women differed from those with normal cholesterol concentrations for biological and nutritional data. These results indicate that low cholesterol concentration is a nonspecific feature of poor health status that is independent of nutrient or energy intake. The role of nutrient factors as a determinant of cholesterol concentration appears marginal in free-living elderly subjects.

Aged↗