scholarly journals Performance evaluation of the Vitros®3600 immunodiagnostic system for the determination of free thyroid hormones

2011 ◽  
Vol 49 (8) ◽  
Author(s):  
Giorgia Querci ◽  
Giulia Galli ◽  
Paolo Piaggi ◽  
Veronica Rosellini ◽  
Monica Giannetti ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Thyroid Hormones ◽  
Free Thyroid Hormones

Serum free thyroid hormones in different degrees of hypothyroidism and in euthyroid autoimmune thyroiditis

1987 ◽  
Vol 114 (4) ◽  
pp. 559-564 ◽  
Author(s):  
C. Ferrari ◽  
A. Paracchi ◽  
E. Parisio ◽  
F. Codecasa ◽  
M. Mucci ◽  
...  
Keyword(s):  
Thyroid Hormones ◽  
Thyroid Function ◽  
Autoimmune Thyroiditis ◽  
Subclinical Hypothyroidism ◽  
Healthy Subjects ◽  
Direct Determination ◽  
Serum Free ◽  
Free Thyroid Hormones ◽  
Hypothyroid Patients

Abstract. Serum total and free T4 and T3, thyroxinebinding globulin (TBG) and TSH, basal and 20, 30 and 60 min after TRH (200 μg, iv), were evaluated in 125 hypothyroid patients (38 with severe, 23 with mild, and 64 with subclinical hypothyroidism), in 35 euthyroid subjects with autoimmune thyroiditis, and in 51 healthy controls. T4/TBG and T3/TBG ratios were also calculated. A significant decrease in all indices of thyroid function except for T3 occurred simultaneously with a significant increase in basal and TRH-stimulated TSH levels from healthy subjects to subclinical hypothyroids, from subclinical to mild and from mild to severe hypothyroids; euthyroid patients with autoimmune thyroiditis did not differ from healthy subjects. All severe hypothyroid patients had low T4 as well as free T4 (FT4), free T3 (FT3), T4/TBG and T3/TBG ratios, but among mild and subclinical hypothyroids direct determination of FT4 and FT3 proved to be a better index of thyroid function than determination of T4 and T3 even after correction for TBG levels. FT4 was the most commonly abnormal index (19 of 23 subjects with mild and 14 of 64 with subclinical disease). Regression analysis showed that FT4, T4/TBG ratio, T4, and FT3 had a significant inverse correlation with TSH in hypothyroid patients. Discriminant analysis showed that among the thyroid parameters, FT4 is the variable which discriminates best between control subjects and the 3 groups of hypothyroid patients. These data extend previous reports and in a large series of patients confirm the biological meaning and the clinical value of direct measurement of serum free thyroid hormones in hypothyroidism. Nevertheless, the finding that both FT4 and FT3 are in the normal range in some patients with mild and in most with subclinical hypothyroidism indicates that increased TSH secretion remains the most sensitive index of thyroid failure.

Determination of free thyroid hormones

2013 ◽  
Vol 27 (5) ◽  
pp. 689-700 ◽  
Author(s):  
Linda M. Thienpont ◽  
Katleen Van Uytfanghe ◽  
Kris Poppe ◽  
Brigitte Velkeniers
Keyword(s):  
Thyroid Hormones ◽  
Free Thyroid Hormones

Transient Prealbumin- Associated Hyperthyroxinemia in TSH-Producing Pituitary Adenoma

1990 ◽  
Vol 29 (01) ◽  
pp. 40-43 ◽  
Author(s):  
W. Langsteger ◽  
P. Költringer ◽  
P. Wakonig ◽  
B. Eber ◽  
M. Mokry ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Case Report ◽  
Pituitary Adenoma ◽  
Thyroid Hormones ◽  
Protein Binding ◽  
Alpha Subunit ◽  
Normal Range ◽  
Thyroxine Binding Globulin ◽  
Free Thyroid Hormones ◽  
Transmission Computed Tomography

This case report describes a 38-year-old male who was hospitalized for further clarification of clinically mild hyperthyroidism. His increased total hormone levels, the elevated free thyroid hormones and the elevated basal TSH with blunted response to TRH strongly suggested a pituitary adenoma with inappropriate TSH incretion. Transmission computed tomography showed an intrasellar expansion, 16 mm in diameter. The neoplastic TSH production was confirmed by an elevated alpha-subunit and a raised molar alpha-sub/ATSH ratio. However, T4 distribution on prealbumin (PA, TTR), albumin (A) and thyroxine binding globulin (TBG) showed a clearly increased binding to PA (39%), indicating additional prealbumin-associated hyperthyroxinemia. The absolute values of PA, A and TBG were within the normal range. After removal of the TSH-producing adenoma, basal TSH, the free thyroid hormones and T4 binding to prealbumin returned to normal. Therefore, the prealbumin-associated hyperthyroxinemia had to be interpreted as a transitory phenomenon related to secondary hyperthyroidism (T4 shift from thyroxine binding globulin to prealbumin) rather than a genetically conditioned anomaly of protein binding.

Analysis and determination of a seasonal performance evaluation for air source heat pumps

2021 ◽  
Vol 43 ◽  
pp. 102574
Author(s):  
Zixu Yang ◽  
Hansong Xiao ◽  
Wenxing Shi ◽  
Mingsheng Zhang ◽  
Baolong Wang
Keyword(s):  
Performance Evaluation ◽  
Heat Pumps ◽  
Seasonal Performance

Effects of small doses of bovine TSH on serum levels of free and total thyroid hormones, their degradation products, and diiodotyrosine

1985 ◽  
Vol 108 (2) ◽  
pp. 211-216 ◽  
Author(s):  
G. Benker ◽  
C. Splittstößer ◽  
H. Meinhold ◽  
Th. Olbricht ◽  
D. Reinwein
Keyword(s):  
Thyroid Hormones ◽  
Degradation Products ◽  
Thyroid Volume ◽  
Serum Levels ◽  
Direct Stimulation ◽  
Absolute Increase ◽  
Free Thyroid Hormones ◽  
Measurable Parameter ◽  
Small Doses ◽  
Bovine Tsh

Abstract. Bovine TSH was administered iv to 10 normal volunteers in doses of 2.5, 7.5, 15 and 30 mU/kg. Brisk elevations of serum diiodotyrosine occurred already after the smallest dose (mean, + 183%) while larger doses had only slight additional effects. T3 rose much higher than T4 (+71% compared to +23% after 15 mU bTSH/kg), and free thyroid hormones exhibited changes similar to total T3 and total T4. The mean absolute increase in serum fT3 ranged from 2.03 to 9.04 pmol/l and proved to be an easily measurable parameter for the TSH effect. Dose-response effects were seen for the increases of fT4, fT3 and T3. TBG and rT3 did not change but the degradation product 3,3'-T2 showed large increments of serum levels. There was no correlation between the response of T3 and T4, fT3 and fT4, or diiodotyrosine and any of the other parameters of thyroid function. The interindividual differences in the magnitude of thyroid hormone response to TSH were considerable, and there was no relationship between this response and thyroid volume by ultrasound. We conclude that direct stimulation of the thyroid gland with bTSH in small doses leads to consistent increases of thyroid hormones, especially T3 and fT3, that the response varies between individuals, and that the precursor diiodotyrosine is released together with thyroid hormones.

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