Thyroid-related Hormones Research Articles

Effect of the Marine Exercise Retreat Program on Thyroid-Related Hormones in Middle-Aged Euthyroid Women.

This study aimed to investigate the effects of a marine exercise retreat program on thyroid-related hormone levels. A total of 62 middle-aged euthyroid women participated in a 6-day marine exercise retreat program. Using thyroid-stimulating hormone (TSH) and free thyroxine (fT4) hormone levels, the participants were divided into high and low-hormone-level groups. Despite decreased TSH and fT4 levels after the program, the factors influencing changes in each group were different. TSH levels were influenced by changes in the normalized low frequency (nLF) of heart rate variability and carbon monoxide (CO) from all the participants, and changes in body fat percentage, nLF, and nitrogen dioxide (NO2) exposure level in the high TSH group. fT4 levels were influenced by changes in body mass index (BMI), NO2 exposure, and particulate matter diameter of 10 µm or less (PM10) exposure in all participants. Changes in BMI and CO exposure influenced the low fT4 group. Lastly, changes in the exercise stress test affected the high fT4 group. Thus, the marine exercise retreat program affected euthyroid thyroid-related hormone levels, and influencing factors differ depending on the initial value of the hormone.

Segmental Abnormalities of White Matter Microstructure in Primary Hypothyroidism Identified by Automated Fiber Quantification

Introduction: Hypothyroidism leads to impaired white matter (WM) integrity, associated with cognitive/neuropsychiatric dysfunction. However, the specific segmental abnormalities of the fibers remain unexplored. Therefore, this study aimed to investigate whether the damage of the WM is limited to a specific segment or the entire bundle via diffusion metrics using automated fiber quantification. Methods: A cross-sectional study was conducted on 31 hypothyroid patients and 28 healthy controls. Thyroid-related hormone levels, cognitive/neuropsychiatric function, and diffusion tensor image data were collected and analyzed. Correlation and random forest analyses were also performed. Results: The mean fractional anisotropy (FA) values were reduced at the fiber tract level. The mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) values were increased in several fiber tracts, i.e., cingulum cingulate (CC), anterior forceps of corpus callosum (CCF_A). Significant correlations were found between cognitive function and diffusion indicators such as the FA value of the left corticospinal tract and arcuate fasciculus (AF), the MD value of left CC, the RD value of left AF, the AD value of left CC, and CCF_A. The widespread microstructure disruption was spread on multiple specific segments of different tracts at the point-wise level. The random forest revealed that the accuracy of recognizing hypothyroid patients was 82.5%, with the anterior component of CCF_A having the most significant contribution. Conclusion: WM microstructural integrity impairments were found in multi-segments of the multiple fiber bundles in hypothyroidism, which might be a potential mechanism of the underlying neurocognitive decline and cerebral impairment. The CCF_A might serve as a neuro biomarker for early warning of cerebral impairment in hypothyroidism.

Clinical value of thyroid related hormones combined with neutrophil to lymphocyte ratio in patients with nonalcoholic fatty liver disease

In sufferers with nonalcoholic fatty liver disease (NAFLD), the differences of thyroid associated hormones and neutrophil to lymphocyte ratio (NLR) in different liver pathological groups have been compared. Patients with NAFLD diagnosed by liver biopsy in our hospital from July 2012 to February 2019 were selected. All subjects were divided into nonalcoholic steatohepatitis (NASH) team and non-NASH group, no/mild fibrosis group (F0-1) and significant fibrosis group (F2-4). The differences of thyroid related hormones and NLR in these groups were in contrast, respectively. For the TSH, we conducted further evaluation based on gender. The TSH and NLR in NASH patients were significantly higher than non-NASH patients, but there was no considerable difference in free triiodothyronine (FT3) and free thyroxine (FT4) between the 2 groups. In the gender-based subgroup analysis, the variations of TSH between the 2 groups were nonetheless statistically significant (P < .05). The TSH and NLR in the significant fibrosis group were higher than these in the non/mild liver fibrosis group, and the differences were statistically significant (P < .05), but there was no large difference in FT3 and FT4 between the 2 groups (P > .05). In addition, in the gender-based subgroup analysis and further multivariable analysis, the variations of TSH between the 2 groups were still statistically significant (P < .05). In this study, we found that serum thyroid stimulating hormone (TSH) and neutrophil to lymphocyte ratio (NLR) were closely associated to the severity of NAFLD, suggesting that this simple available laboratory index may additionally be incorporated into the future noninvasive diagnostic scoring model to predict the incidence of NASH and the degree of fibrosis.

The associations between thyroid-related hormones and the risk of thyroid cancer: An overall and dose-response meta-analysis.

Thyroid cancer (TC) is one of the most common malignant tumours of the endocrine system. Thyroid-stimulating hormone (TSH) is known as being a risk factor for TC, but other thyroid-related hormones are inconsistently associated with TC. The purpose of this study was to comprehensively evaluate the relationships between thyroid-related hormones and the risk of TC. This study utilized searches of PubMed, Embase, Web of Science and Cochrane library up to the date of March 31st, 2022. Additionally, we performed a systematic review of related original studies combining overall and dose-response meta-analyses. A total of 30, 5 and 7 articles were included in the meta-analyses of TSH, Free triiodothyronine (FT3), free thyroxine (FT4) and TC risk with 58437, 6813 and 7118 participants respectively. An increased risk of TC was associated with high TSH exposure (OR=1.28, 95% CI: 1.19-1.37, P < 0.001) in the overall meta-analysis. For every 1 mU/L increase in TSH, the risk of TC increased by 16%. However, in those studies that used healthy subjects as controls, the association was not statistically significant(P=0.62). Additionally, high serum FT3 demonstrated a reduced risk of TC, with a combined OR of 0.86 in the fixed-effect model (95% CI: 0.81-0.90, P < 0.001). In addition, a statistically significant increase in TC risk was found when FT4 concentrations reached a certain threshold (approximately 2.2 ng/dL) in the dose-response meta-analysis. Significant associations between thyroid-related hormones and the risk of TC were found in this study. Further research is needed to understand the underlying mechanisms.

Correlation of thyroid-related hormones with vascular complications in type 2 diabetes patients with euthyroid.

This study aimed to evaluate the relationship between thyroid-related hormones and vascular complications in type 2 diabetes mellitus (T2DM) patients with euthyroidism. We enrolled 849 patients with T2DM after screening out the ineligible. Multivariate logistic regression was used to analyze the relationship between fT3, fT4, the fT3/fT4 ratio, thyroid-stimulating hormone, and diabetic vascular complications. Spearman correlation analysis was used to determine the correlation between thyroid-related hormones and vascular complications. In this cross-sectional study of T2DM, 538 patients with carotid atherosclerosis (CA) and 299 patients with diabetic peripheral neuropathy (DPN). The prevalence of DPN was negatively correlated with fT3 and the fT3/fT4 ratio but positively correlated with fT4 (all P<0.01). At the same time, the odds ratio for DPN decreased with increasing fT3 (T1: reference; T2: OR: 0.689, 95%CI: 0.477, 0.993; T3: OR: 0.426, 95% CI: 0.286, 0.633, all P<0.05) and fT3/fT4 ratio (T1: reference; T2: OR: 0.528, 95% CI: 0.365, 0.763; T3: OR: 0.413, 95% CI: 0.278, 0.613, all P<0.001). In terms of sensitivity and specificity, fT4 was found to be 39.5% and 71.4% accurate, respectively, with a 95% CI of 0.531-0.611. We found a negative correlation between fT3 and fT3/fT4 ratio and the number of individuals with DPN, and a positive correlation between fT4 and the prevalence of DPN.

An innovative approach based on real-world big data mining for calculating the sample size of the reference interval established using transformed parametric and non-parametric methods

BackgroundCurrently, the direct method is the main approach for establishment of reference interval (RI). However, only a handful of studies have described the effects of sample size on establishment of RI and estimation of sample size. We describe a novel approach for estimation of the sample size when establishing RIs using the transformed parametric and non-parametric methods.MethodsA total of 3,697 healthy participants were enrolled in this study. We adopted a two-layer nested loop sample size estimation method to determine the effects of sample size on RI, using thyroid-related hormone as an example. The sample size was selected as the calculation result when the width of the confidence interval (CI) of the upper and lower limit of the RI were both stably < 0.2 times the width of RI. Then, we calculated the sample size for establishing RIs via transformed parametric and non-parametric methods for thyroid-related hormones.ResultsSample sizes for thyroid stimulating hormone (TSH), as required by parametric and non-parametric methods to establish RIs were 239 and 850, respectively. Sample sizes required by the transformed parametric method for free triiodothyronine (FT3), free thyroxine (FT4), total triiodothyronine (TT3) and total thyroxine (TT4) were all less than 120, while those required by the non-parametric method were more than 120.ConclusionWe describe a novel approach for estimating sample sizes for establishment of RI. A corresponding open-source code has been developed and is available for applications. The established method is suitable for most analytes, with evidence based on thyroid-related hormones indicating that different sample sizes are required to establish RIs using different methods for analytes with different variations.

Hypothyroidism correlates with dyslipidemia and protein contents in patients with various metabolic disorders.

ObjectivesThe present study aimed to investigate the status of abnormalities in thyroid-related hormones, lipid profile parameters and total proteins in the sera of patients suffering from various metabolic disorders.MethodsTo analyze the study parameters, enzyme-linked immunosorbent assays, Bradford assays and standard clinical kits and methods were applied. Data were analyzed through the appropriate statistical tests.ResultsIn all subjects except those with hypotension, thyroid-stimulating hormone, total cholesterol and low-density lipoprotein were elevated, whereas triiodothyronine levels were downregulated. Thyroxin was downregulated in subjects with diabetes and symptomatic thyroiditis but upregulated in patients with hypertension. High-density lipoprotein was upregulated in men who were diabetic only, and total protein was downregulated in those with hypotension only. Hypothyroidism in patients with diabetes, symptomatic thyroiditis and hypertension was correlated with dyslipidemia. In subjects with hypertension, it was correlated with total protein.ConclusionThis study revealed a link between hypothyroidism, dyslipidemia and total protein in patients with various metabolic disorders.

Multiple mediation effects on association between prenatal triclosan exposure and birth outcomes

BackgroundTriclosan is a broad-spectrum antimicrobial, and was thought to affect intrauterine development, but the mechanism remains unclear. ObjectiveTo explore the association between prenatal triclosan exposure and birth outcomes. MethodsBased on 726 mother-child pairs from the Sheyang Mini Birth Cohort Study (SMBCS), we used the available (published) data of triclosan in maternal urines, the hormones including thyroid-related hormones, gonadal hormones in cord blood, and adipokines, trimethylamine-N-oxide (TMAO) and its precursors in cord blood to explore possible health effects of triclosan on birth outcomes through assessing different hormones and parameters, using Bayesian mediation analysis. ResultsMaternal triclosan exposure was associated with ponderal index (β = 0.317) and head circumference (β = −0.172) in generalized linear models. In Bayesian mediation analysis of PI model, estradiol (β = 0.806) and trimethylamine (TMA, β = 0.164) showed positive mediation effects, while total thyroxine (TT4, β = −0.302), leptin (β = −2.023) and TMAO (β = −0.110) showed negative mediation effects. As for model of head circumference, positive mediation effects were observed in free thyroxine (FT4, β = 0.493), TMA (β = 0.178), and TMAO (β = 0.683), negative mediation effects were observed in TT4 (β = −0.231), testosterone (β = −0.331), estradiol (β = −1.153), leptin (β = −2.361), choline (β = −0.169), betaine (β = −0.104), acetyl-L-carnitine (β = −0.773). ConclusionThe results indicated triclosan can affect intrauterine growth by interfering thyroid-related hormones, gonadal hormones, adipokines, TMAO and its precursors.

Validation and comparison of five data mining algorithms using big data from clinical laboratories to establish reference intervals of thyroid hormones for older adults

AimTo establish Reference intervals (RIs) of thyroid-related hormones in older adults using five data mining algorithms and to assess the applicability of each algorithm. MethodsRIs for thyroid-related hormones in older adults were established using five data mining algorithms based on physical examination and patient data. The results of these algorithms were compared to those of RIs established using healthy older adults recruited following strict inclusion and exclusion criteria. The bias ratio (BR) matrix was used to compare the limits of RIs established using different algorithms. ResultsConsistency across different algorithms in physical examination data was found to be greater than that of outpatient data. The transformed Hoffmann, transformed Bhattacahrya, kosmic and refineR algorithms showed good performance in calculating RIs from physical examination data. The RIs of Thyroid Stimulating Hormone (TSH) established using Expectation maximization (EM) and patient data were highly consistent with the RIs established using data from healthy older adults. ConclusionThis study recommends the use of transformed Hoffmann, transformed Bhattacahrya, kosmic, and refineR algorithms which are based on physical examination data to establish RIs for thyroid-related hormones in older adults. However, if patient data is used, then an EM algorithm combined with Box-Cox transformation is recommended for data with obvious skewness.

The Association Between COVID-19 and Thyroxine Levels: A Meta-Analysis.

ObjectivesRecently, a number of reports have described the potential relationship between COVID-19 and thyroid hormones, but the results were conflicting. We performed a meta-analysis to evaluate the effect of the severity of COVID-19 on thyroid-related hormones and the effect of thyroid-related hormones on the outcome of COVID-19 in order to try to confirm the association between the serum levels of free triiodothyronine (FT3), free thyroxine (FT4) and thyroid stimulating hormone (TSH) and the severity or mortality of coronavirus-19 patients.MethodsThe methodology was already registered in the International Prospective Register of Systematic Reviews (PROSPERO) database, and the protocol number is CRD42021269246. Systematic searches were carried out on the Cochrane Library, Embase, PubMed and Web of Science databases on November 15, 2021. We set up the literature search strategy based on the following keywords: [(T3 OR FT3 OR triiodothyronine) or (T4 OR FT4 OR thyroxine) or (TSH or thyrotropin)] and (COVID-19 OR SARS-CoV-2), without time restrictions.ResultsTwenty studies satisfied the inclusion/exclusion criteria and were included in the meta-analysis. A total of 3609 patients were enrolled in the study. From the analysis of the included studies, the incidence of thyroid-related hormone abnormalities was higher in patients with severe COVID-19, and the serum levels of FT3 and TSH were lower than those of patients with nonsevere COVID-19. However, the difference in the FT4 levels was not significant. Similar characteristics were shown between survivors and nonsurvivors. In addition, the outcomes of the meta-analysis showed that patients with abnormal thyroid-related hormones had greater mortality.ConclusionsLow FT3 serum levels, low FT4 serum levels and low TSH serum levels may increase the mortality of COVID-19 patients during admission. On the other hand, the higher the severity level of COVID-19, the higher the probability of decreases in the FT3, FT4, TSH levels.

Thyroid functions in patients with hypochondriasis.

No studies of thyroid-related hormone levels have been conducted in patients with hypochondriasis to date. The aim of this study is to examine thyroid-related hormones in patients with hypochondriasis. Sixty patients with hypochondriasis and 138 healthy controls were included in this study. Patients with hypochondriasis who applied to the psychiatry outpatient clinic and met the study criteria and healthy controls were determined by chart analysis. According to the results of the comparisons, TSH, fT3, and fT4 levels did not show a statistically significant difference between hypochondriasis patients and healthy controls. Thyroid hormone levels are not associated with hypochondriasis.

Effect of Di-(2-ethylhexyl) phthalate on the hypothalamus-pituitary-thyroid axis in adolescent rat.

Di-(2-ethylhexyl) phthalate (DEHP) is extensively used in many personal care and consumer products, which results in widespread human exposure. Limited studies have suggested that exposure to DEHP may affect thyroid function, but little is known about the effect and mechanisms of DEHP exposure on the hypothalamic-pituitary-thyroid axis (HPTA). The present study was conducted to elucidate the potential mechanisms underlying DEHP disrupting the function of the HPTA. DEHP was administered to Wistar rats by gavage at 0, 5, 50, and 500 mg/kg/day for consecutive 28 days and then the rats were sacrificed within 24 h following the last dose. The hormone levels of HPTA were quantified with radioimmunoassay and enzyme-linked immunosorbent assay, the protein levels of thyrotropin-releasing hormone receptor (TRHR) and thyroid-stimulating hormone receptor (TSHR) were analyzed by Western blot and immunohistochemistry, and the expression levels of TRHR and TSHR mRNA were measured by quantitative real-time PCR. The low dose of DEHP increased the body weights of rats. Serum levels of T3, T4, FT3 and FT4 as well as protein and mRNA levels of TSHR decreased in rats treated with 50 mg/kg or 500 mg/kg DEHP compared with those of controls. Although the protein levels of TRH in the hypothalamus or protein and mRNA levels of TRHR in pituitary were up-regulated, serum levels of TSH did not change statistically in rats treated with DEHP. Therefore, DEHP can produce thyroid toxicity and may interfere with the secretion of pituitary TSH. In conclusion, DEHP could interfere with the balance of HPTA of adolescent rats, and disturb the homeostasis of thyroid related hormones and the expression levels of receptors.

Independent associations of thyroid-related hormones with hepatic steatosis and insulin resistance in euthyroid overweight/obese Chinese adults

PurposeThe aim of the study is to explore the independent association of free triiodothyronine (FT3), free thyroxine (FT4) and thyroid stimulating hormone (TSH) with hepatic steatosis and insulin resistance.MethodsA cross-sectional study of 88 overweight/obese adults who underwent anthropometric measurements [BMI, waist circumference (WC) and waist-to-height ratio (WHtR)], hepatic steatosis assessment (FibroScan) and thyroid-related hormones tests was conducted from 2018 to 2020 in Xiamen, China.ResultsSubjects with increasing tertiles of FT3 showed significantly higher levels of controlled attenuation parameter (CAP) ((295.4 ± 44.1, 290.1 ± 68.2 and 331.7 ± 43.6 (dB/m) for tertile 1–3, respectively, p = 0.007) and fatty liver index (FLI) score (47.7 (33.9–60.8), 61.5 (45.1–88.9) and 90.5 (84.5–94.8), respectively, p < 0.001). FT3 significantly and positively correlated with obesity index (BMI, WC, and WHtR), homeostatic model assessment of insulin resistance (HOMA-IR) and hepatic steatosis (CAP and FLI). Multivariable linear regression analyses with adjustment for potential confounding factors showed FT3 was independently associated with BMI (regression coefficient (β (95%CI): 0.024 (0.004–0.043), p = 0.020), HOMA-IR (β (95%CI): 0.091 (0.007–0.174), p = 0.034), CAP (β (95%CI): 25.45 (2.59–48.31), p = 0.030) and FLI (β (95%CI): 0.121 (0.049–0.194), p = 0.001). Neither FT4 nor TSH was significantly associated with any indicators of obesity, insulin resistance or hepatic steatosis.ConclusionsIncreased FT3, but not FT4 or TSH, was independently associated with higher risks of hepatic steatosis and insulin resistance in euthyroid overweight/obese Chinese adults.Trial registration Registration is not applicable for our study.

Thyroid-Related Hormone Levels in Clinical Patients With Moderately Severe-to-Profound Sudden Sensorineural Hearing Loss: A Prospective Study.

Objectives: Sudden sensorineural hearing loss (SSNHL) is a common otological emergency, causing a measure of hearing loss and affecting the quality of life. This study aims to investigate the association of thyroid-related hormone levels with moderately severe-to-profound SSNHL.Methods: The study included 70 patients with moderately severe-to-profound SSNHL and 100 age- and sex-matched healthy controls. Peripheral venous blood samples were taken from the participants, and their thyroid-related hormone levels were measured at admission and 1 week after treatment.Results: In moderately severe-to-profound SSNaHL patients, the concentrations of total triiodothyronine (TT3), total thyroxine (TT4), free triiodothyronine (FT3), and thyroid-stimulating hormone (TSH) (all P < 0.05) were significantly lower than in the control group. The TT3, TT4, FT3, and TSH levels were significantly higher in the effective group than in the ineffective group (all P < 0.05). Linear correlation analysis revealed that TSH level (R = 0.707, P < 0.05) elevation after treatment successfully predicted a favorable outcome of hearing recovery. Logistic regression analyses suggested low FT3 and TSH levels to be independent occurrence predictors, while the increase of TSH level may be an independent favorable outcome predictor.Conclusions: The results suggest that low FT3 and TSH levels are risk factors for moderately severe-to-profound SSNHL. By discovering the positive association between TSH elevation and hearing recovery, along with the potential novel predictors of FT3 and TSH, our study may contribute valuable insights to the research and treatment of moderately severe-to-profound SSNHL.

Preliminary study of genome-wide association identified novel susceptibility genes for thyroid-related hormones in Chinese population.

Thyroid hormones are critical regulators of metabolism, development and growth in mammals. However, the genetic association of thyroid-related hormones in the Chinese Han population is not fully understood. We aimed to identify the genetic loci associated with circulating thyroid-related hormones concentrations in the healthy Chinese Han population. Genotyping was performed in 124 individuals using Applied Biosystems™ Axiom™ PMDA, and 796,288 single nucleotide polymorphisms (SNPs) were available for the GWAS analysis. For replication, eleven SNPs were selected as candidate loci for genotyping by Agena MassARRAY platform in additional samples (313 subjects). The values of p < 5 × 10- 6 suggest a suggestively significant genome-wide association with circulating thyroid-related hormones concentrations. We identified that rs11178277 (PTPRB, p = 4.88 ×10- 07) and rs7320337 (LMO7DN-KCTD12, p = 1.22 × 10- 06) were associated with serum FT3 level. Three SNPs (rs4850041 in LOC105373394-LINC01249: p = 3.55 × 10- 06, rs6867291 in LINC02208: p = 2.40 × 10- 06 and rs79508321 in WWOX: p = 3.35 × 10- 06) were related to circulating T3 level. Rs12474167 (LOC105373394-LINC01249, p = 1.65 × 10- 06) and rs1864553 (IWS1, p = 2.00 × 10- 06) were associated with circulating T4 concentration. The association with TGA concentration was for rs17163542 in DISP1 (p = 3.46 × 10- 06) and rs12601151 in NOG-C17orf67 (p = 2.72 × 10- 07). Two genome-level significant SNPs (rs2114707 in LINC01314, p = 1.69 × 10- 06 and rs12601151, p = 1.41 × 10- 07) associated with serum TMA concentration were identified. Moreover, rs6083269 (CST1-CST2, p = 3.36 × 10- 06) was a significant locus for circulating TSH level. In replication, rs12601151 in NOG-C17orf67 was still associated with serum TGA level (p = 0.012). The GWAS reported 11 new suggestively significant loci associated with circulating thyroid-related hormones levels among the Chinese Han population. These findings represented suggestively biological candidates for circulating thyroid-related hormones levels and provided new insights into the mechanisms of regulating serum TGA concentration.

HbA1c is inversely associated with thyroid cysts in a euthyroid population: A cross-sectional study

Anti-thyroid peroxidase antibody (TPO-Ab) is revealed to be inversely associated with thyroid cysts among euthyroid population. TPO-Ab causes autoimmune thyroiditis by bolstering thyroid inflammation. Therefore, at least partly, absence of thyroid cysts could indicate latent thyroid damage. Since participants with subclinical hypothyroidism are reported to have higher HbA1c than normal healthy controls, HbA1c could be inversely associated with thyroid cysts through a mechanism reflecting latent thyroid damage. To investigate the association between HbA1c and thyroid cysts among a euthyroid population, a cross-sectional study was conducted on 1,724 Japanese individuals who were within the normal range of thyroid function [i.e., normal range of free triiodothyronine (T3) and free thyroxine (T4)] and aged 40-74 years. Among this study population, 564 were diagnosed with thyroid cysts. Independently of thyroid related hormones [thyroid stimulating hormone (TSH), free T3, and free T4] and known cardiovascular risk factors, HbA1c was found to be significantly inversely associated with the presence of thyroid cysts. This association remained significant even after this analysis was limited to participants within a normal range of TSH. The fully adjusted odds ratios (ORs) of thyroid cysts for 1 standard deviation (SD) increment of HbA1c were 0.84 (0.74, 0.95) for total participants and 0.80 (0.70, 0.92) for participants within a normal range of TSH. Among participants with normal thyroid function, HbA1c was inversely associated with the presence of thyroid cysts. The absence of thyroid cysts and higher levels of HbA1c could indicate the latent functional damage of the thyroid.

Exposure to Melamine cyanuric acid in adolescent mice caused emotional disorder and behavioral disorder

Melamine cyanuric acid (MCA) is a flame retardant linked by hydrogen bonds between melamine and cyanuric acid. MCA is used in an excellent series of phosphorus and nitrogen flame retardants. MCA can harm the kidney, liver, testis, and spleen cells. However, the effects of MCA on the emotions and behaviour of adolescent mice have not yet been investigated. In this article, male mice were exposed to MCA at 10, 20, and 40 mg/kg for four weeks. MCA exposure resulted in enhanced mouse locomotor and nocturnal activity. We also observed anxiety-like and depression-like behaviours. Moreover, after MCA exposure, the serum concentrations of thyroid-related hormones were changed, and the mRNA levels were affected. In short, MCA exposure can cause behavioural and emotion disorders.

Serum Triiodothyronine, Thyroxine, and Thyroid Stimulating Hormone Concentrations of Domestic Female Cats at Different Reproductive Stages

Thyroid hormones have various roles in different physiological systems in the body. Thus, thyroid dysfunction is common in cats, in this study, we aimed to determine the normal values of triiodothyronine (T3), thyroxine (T4), and thyroid-stimulating hormone (TSH) in the blood of female cats at different phases of the estrous cycle. Queens were divided into three groups as estrous (n=14), diestrus (n=12), and interestrus (n=10) according to findings of vaginal cytology, ovarian inspection, and serum estradiol (E2) and progesterone (P4) concentrations. Blood samples were collected before the ovariohysterectomy, and the obtained sera were analyzed for free T3, free T4, TSH, E2, and P4. The results showed that the highest T3 and T4 concentrations were found in cats at interestrus while the lowest T3 and T4 concentrations were found at diestrus and estrus, respectively. The level of TSH in all cats was below the detection limit of the assay. The mean concentrations of thyroid-related hormones in each group showed non-significant variations (P&gt;0.05). The correlation between ovarian and thyroidal hormones was not statistically significant (P&gt;0.05). In conclusion, it is required to further comprehensive/experimental studies to exhibit the interaction between ovarium and thyroid gland because of its importance.

Development of a Movable Membrane Probe for the Pretreatment of Target Analytes in the Electrochemistry Based Assay

In this paper, we electrochemistry based immunoassay system using newly developed movable membrane probe which we used as pretreatment before the measurement of target analytes. We used Alkaline phosphatase (ALP) as enzyme which is widely used for an enzyme in immuno-sensor due to its high stability of reaction, long storage life, and high turnover rates. [1] For the enzymatic hydrolysis and activity for electrochemistry, we used a substrate as p-aminophenyl phosphate (pAPP). In addition, we utilized co-enzyme, tris(2-carboxyethyl) phosphine (TCEP), for the enhanced measurement signal in the substrate for the amplification of relatively low signal in electrochemical measurement. [2] The developed moveable membrane probe provided a simple methodology regarding the conjugation of antibodies on surfaces and washing process compared to manually orchestrated normal ELISA. The main advantage of this system is the easiness of washing steps, we could produce lower background signal which eventually resulted in an increase of the signal to noise ratio. This membrane probe was designed to be implemented to the platform which was newly developed all in one electrochemisty based immunoassay platform names as IMPACT.Using this base platform and movable probe, we could measure thyroid related hormones in successive ways even their presence in extremely low ranges.

Association between Thyroid Hormones, Apolipoprotein E, and Cognitive Function among Cognitively-Normal Elderly Dwellers.

ObjectiveThe correlation among the thyroid-related hormones, Apolipoprotein E ε4 (APOE ε4) and cognitive function has been reported despite controversial results. This study was designed to investigate this correlation among cognitively-normal elderly dwellers. MethodsThis study assessed 507 cognitively normal individuals aged over 60 who underwent comprehensive hematological and neuropsychological assessments including the quantification of serum free thyroxine and thyroid stimulating hormone (TSH) as well as the Korean version of the Consortium Establish a Registry for Alzheimer’s disease. The Korean version of Geriatric Depression Scale was also employed to evaluate the severity of depression. Age, gender, education, and the presence of APOE ε4 were taken into account as covariates. ResultsThere was a significant positive association between verbal fluency test (VFT), Word List Memory Test (WLMT), and Word List Recall Test (WLRT) score and serum TSH levels (p=0.007, 0.031, and 0.023 respectively). The further analysis adding the interaction between APOE ε4 and TSH level, however, revealed only VFT score was significantly influenced by this interaction (p=0.026). ConclusionLower serum TSH levels had impacts on both semantic memory (VFT) and episodic memory (WLMT, WLRT) among cognitively-normal elderly, whereas the interaction of TSH and APOE ε4 influenced only the task of semantic memory (VFT) in this group.