Pictorial reporting of multiple thyroid function results.

1976 ◽  
Vol 22 (10) ◽  
pp. 1562-1566
Author(s):  
R W Pain ◽  
B M Duncan
Keyword(s):  
Thyroid Function ◽  
Reporting System ◽  
Free Thyroxine ◽  
Thyroid Function Tests ◽  
Testing Procedures ◽  
Function Tests ◽  
Free Thyroxine Index ◽  
Total Thyroxine ◽  
Experience Difficulty

Abstract Clinicians experience difficulty in correctly interpreting the results of in vitro thyroid function tests in the presence of abnormalities of thyrobinding proteins or when results are borderline. This difficulty has been largely resolved in our laboratory by three innovations. First, the borderline areas for each of three routine tests of thyroid function (total thyroxine, thyrobinding index, and free thyroxine index) were accurately determined. Second, the results from this routine profile of three tests were displayed pictorially so as to produce patterns characteristic of various diagnostic situations, including euthyroidism in the presence of abnormalities of thyrobinding proteins. Third, interpretive comments and, in the case of borderline patterns, suggested further testing procedures were added to the report. Clinicians find the reporting system helpful and respond when additional tests are suggested. The system, operated manually at first, was later computerized.

THYROID FUNCTION TESTS DURING PREGNANCY, THE NORMAL MENSTRUAL CYCLE AND IN WOMEN USING ORAL CONTRACEPTIVES

1969 ◽  
Vol 43 (2) ◽  
pp. 217-224 ◽  
Author(s):  
RUTH M. STANDEVEN
Keyword(s):  
Menstrual Cycle ◽  
Thyroid Function ◽  
Oral Contraceptives ◽  
Free Thyroxine ◽  
Thyroid Function Tests ◽  
Clinical Use ◽  
Thyroid Status ◽  
Function Tests ◽  
Free Thyroxine Index ◽  
Normal Menstrual Cycle

SUMMARY Endogenous and exogenous oestrogenic effects on thyroid function tests were studied. [125I]Tri-iodothyronine charcoal uptake (T3 uptake) and protein-bound iodine (PBI) were measured in serum obtained from women during the menstrual cycle and the different trimesters of pregnancy and from women taking oral contraceptives for varying periods of time. The free thyroxine index (FTI) was calculated for the pregnant subjects and the free thyroxine factor (FTF) evaluated for all samples studied. Significant deviations from control values in T3 uptake, PBI, FTI and FTF could not be correlated with relatively large changes in the levels of oestrogens. T3 uptake results appeared to reflect changing oestrogenic patterns more closely than the corresponding PBI measurements. Evidence presented suggests that the FTF is preferred to the FTI for clinical use in the diagnosis of thyroid status although further modification to the FTF formula involving PBI and [125I]T3 charcoal uptake measurements may be necessary.

Lowering effect of diphenylhydantoin on serum free thyroxine and thyroxine binding globulin (TBG)

1984 ◽  
Vol 105 (4) ◽  
pp. 477-481 ◽  
Author(s):  
Hitoshi Suzuki ◽  
Noriko Yamazaki ◽  
Yoshinobu Suzuki ◽  
Masaki Hiraiwa ◽  
Shin-ichi Shimoda ◽  
...  
Keyword(s):  
Thyroid Function ◽  
Serum Levels ◽  
Significant Negative Correlation ◽  
Free Thyroxine ◽  
Thyroid Function Tests ◽  
Duration Of Treatment ◽  
Function Tests ◽  
Total Triiodothyronine ◽  
Total Thyroxine ◽  
Anticonvulsant Treatment

Abstract. To evaluate the effect of anticonvulsants on serum levels of free thyroxine (FT4) and thyroxinebinding globulin (TBG), 32 patients with epilepsy receiving long-term anticonvulsant treatment (mean duration 81.8 ± 8.9 months) were employed in the present study. The serum levels of total thyroxine (TT4), total triiodothyronine (TT3), T3 resin uptake (T3U) and thyrotrophin (TSH) were also measured. Free thyroxine index (FT4I) was calculated from TT4 and T3U. Mean levels of these thyroid function tests were as follows: 5.52 ± 1.51 μg/dl (TT4), 1.16 ± 0.32 ng/dl (FT4), 101.5 ± 16.2 ng/dl (TT3), 27.5 ± 2.6% (T3U), 19.64 ± 3.97 μg/ml (TBG), 1.50 ± 0.36 (FT4I) and 2.21 ± 0.18 μU/ml (TSH). These values except for T3U and TSH were significantly lower than normal values (P < 0.01). Using correlation analysis, a significant dose-dependency (daily doses) was found between diphenylhydantoin (DPH) and TT4, FT4 and TBG. Other anticonvulsants (bartiturates, carbamazepine, primidone) or duration of treatment were not significantly correlated with thyroid function tests. Therefore serum levels of DPH were also measured in 19 out of 32 patients receiving anticonvulsant treatment. Significant negative correlation was found between serum levels of DPH and FT4 (r = −0.65) and DPH and TBG (r = −0.61).

Investigation of the Free and Total Thyroxine-binding Capacity of Plasma Proteins in Thyroid Disorders

1971 ◽  
Vol 10 (04) ◽  
pp. 299-304
Author(s):  
József Takó ◽  
János Fischer ◽  
Jusztina Juhász ◽  
Ilona Sztraka ◽  
István Kapus ◽  
...  
Keyword(s):  
Blood Cell ◽  
Thyroid Function ◽  
Oral Contraceptives ◽  
Red Blood Cell ◽  
Plasma Proteins ◽  
Binding Capacity ◽  
Thyroid Disorders ◽  
Thyroid Function Tests ◽  
Total Thyroxine

SummaryThe results of thyroid function tests have been compared with data on the thyroxine-binding capacity of plasma proteins in hyper-, hypo- and euthyroid cases, the latter including women taking oral contraceptives (Infecundin). It was found that there exists a significant correlation of exponential nature between the in vitro red blood cell 125I-triiodothyronine uptake (RCU) and the free thyroxine-binding capacity of the thyroxine-inding globulin (TBG).

Subclinical hypothyroidism

2011 ◽  
pp. 543-547
Author(s):  
Jayne A. Franklyn
Keyword(s):  
Thyroid Function ◽  
Subclinical Hypothyroidism ◽  
Expert Panel ◽  
Elevated Serum ◽  
Thyroid Stimulating Hormone ◽  
Free Thyroxine ◽  
Thyroid Function Tests ◽  
Free Triiodothyronine ◽  
Function Tests ◽  
Serum Tsh

Subclinical hypothyroidism is defined biochemically as the association of a raised serum thyroid-stimulating hormone (TSH) concentration with normal circulating concentrations of free thyroxine (T4) and free triiodothyronine (T3). The term subclinical hypothyroidism implies that patients should be asymptomatic, although symptoms are difficult to assess, especially in patients in whom thyroid function tests have been checked because of nonspecific complaints such as tiredness. An expert panel has recently classified individuals with subclinical hypothyroidism into two groups (1): (1) those with mildly elevated serum TSH (typically TSH in the range 4.5–10.0 mU/l) and (2) those with more marked TSH elevation (serum TSH >10.0 mU/l).

Simple modifications of three routine in vitro tests of thyroid function.

1976 ◽  
Vol 22 (10) ◽  
pp. 1715-1718 ◽  
Author(s):  
R W Pain
Keyword(s):  
Diagnostic Accuracy ◽  
Thyroid Function ◽  
False Positive ◽  
Reference Range ◽  
False Negative ◽  
Work Load ◽  
In Vitro Tests ◽  
Free Thyroxine Index ◽  
Total Thyroxine

Abstract Semi-automation of equipment and simple modifications of technique reduced the work load without loss of diagnostic accuracy for three commonly used in vitro tests of thyroid function (total thyroxine, thyrobinding index, and free thyroxine index). Major innovations were the use of serum standards for all tests and having each duplicate for tests performed by a different technician. Attention is drawn to the false-positive and false-negative errors that occur when the 95% euthyroid limits is the sole reference range used.

THE EFFECTS OF PHENYLBUTAZONE ON THYROID FUNCTION

1973 ◽  
Vol 72 (2) ◽  
pp. 257-264 ◽  
Author(s):  
M. O. Abiodun ◽  
R. Bird ◽  
C. W. H. Havard ◽  
N. K. Sood
Keyword(s):  
Thyroid Function ◽  
Significant Rise ◽  
Free Thyroxine ◽  
Continuous Treatment ◽  
Total Serum ◽  
Thyroid Function Tests ◽  
Tsh Secretion ◽  
Total Thyroxine ◽  
Pre Treatment ◽  
Tsh Levels

ABSTRACT It is known that phenylbutazone suppresses the thyroidal uptake of radioactive iodine and the serum level of protein-bound iodine (PBI) during the first week of treatment, with a return to normal values after 2 weeks of continuous treatment. Up till now the initial suppression of thyroid function has been presumed due to inhibition of TSH secretion. In the present study, total serum thyroxine and percentage dialysable thyroxine have been measured and the serum absolute free thyroxine concentration calculated in 12 patients before starting treatment with phenylbutazone orally, after 4 days of treatment and again after 14 days. Serum TSH was assayed in 10 of these patients before, and on the 4th day of treatment. Sera were assayed for TSH after 14 days on the drug in 6 patients. On the 4th day of treatment, the levels of total thyroxine had fallen but the levels of free thyroxine remained unchanged. TSH levels were also unaltered. By the 14th day of treatment, free thyroxine levels had fallen significantly below pre-treatment values but no significant rise in TSH could be demonstrated in the 6 patients studied. At no time was there a fall in TSH levels and we conclude that suppression of some thyroid function tests during the first week of treatment with phenylbutazone is due to direct inhibition of the gland by the drug.

scholarly journals Report of the IFCC Working Group for Standardization of Thyroid Function Tests; Part 2: Free Thyroxine and Free Triiodothyronine

2010 ◽  
Vol 56 (6) ◽  
pp. 912-920 ◽  
Author(s):  
L. M. Thienpont ◽  
K. Van Uytfanghe ◽  
G. Beastall ◽  
J. D. Faix ◽  
T. Ieiri ◽  
...  
Keyword(s):  
Thyroid Function ◽  
Working Group ◽  
Free Thyroxine ◽  
Thyroid Function Tests ◽  
Free Triiodothyronine ◽  
Function Tests

scholarly journals L-T4 Therapy in the Presence of Pharmacological Interferents

2020 ◽  
Vol 11 ◽  
Author(s):  
Salvatore Benvenga
Keyword(s):  
Thyroid Function ◽  
Cardiovascular Complications ◽  
Primary Hypothyroidism ◽  
Free Thyroxine ◽  
Thyroid Function Tests ◽  
Central Hypothyroidism ◽  
Serum Free ◽  
Function Tests ◽  
Frequent Monitoring ◽  
Serum Free Thyroxine

Pharmacological interference on L-thyroxine (L-T4) therapy can be exerted at several levels, namely from the hypothalamus/pituitary through the intestine, where the absorption of exogenous L-T4 takes place. A number of medications interfere with L-T4 therapy, some of them also being the cause of hypothyroidism. The clinician should be aware that some medications simply affect thyroid function tests with no need of modifying the dose of L-T4 that the patient was taking prior to their prescription. Usually, the topic of pharmacological interference on L-T4 therapy addresses the patient with primary hypothyroidism, in whom periodic measurement of serum thyrotropin (TSH) is the biochemical target. However, this minireview also addresses the patient with central hypothyroidism, in whom the biochemical target is serum free thyroxine (FT4). This minireview also addresses two additional topics. One is the costs associated with frequent monitoring of the biochemical target when L-T4 is taken simultaneously with the interfering drug. The second topic is the issue of metabolic/cardiovascular complications associated with undertreated hypothyroidism.

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