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Background and Objective: Clinical studies have suggested that low tri-iodothyronine (T3) syndrome negatively affects the clinical outcomes of patients with acute heart failure (AHF). The aim of this prospective cohort study was to evaluate the effect of low T3 syndrome in terms of prognosis and risk-predictive potential in AHF. Methods: A prospective observational cohort study was conducted from April 2012 to August 2016 in Nanjing, China. All clinical baseline characteristics were retrieved from electronic medical records. Low T3 syndrome was defined by a low free T3 level (

Background: Pregnancy has great influence on maternal thyroid gland. It induces significant physiological as well as hormonal changes that alters the maternal thyroid function. Our goal was to determine this pregnancy associated changes in thyroid gland. Objective: To correlate the sonographic findings of maternal thyroid gland with thyroid function tests during pregnancy. Material and methods: 135 pregnant women were recruited in this study, data of TSH, T3 and T4 was obtained and correlated it with the sonographic findings of maternal thyroid gland in each trimester of pregnancy. Results: In the 135 sampled pregnant women, mean thyroid gland volume was 4.08±1.19 cm3. The mean levels of T3, T4 and TSH were v3.37±.44 pmol/L, 14.96±2.49 pmol/L and 1.21±.92 mIU/L respectively. A remarkable correlation between thyroid hormones and thyroid volume was observed. Conclusion: It is concluded that the ultra-sonographic findings is correlated with the thyroid function tests during pregnancy.

Background Low triiodothyronine (T3) syndrome could be a powerful prognostic factor for acute stroke; yet, a prognostic role for low T3 has not been given enough importance in stroke management. This meta-analysis aimed to evaluate whether low T3 among acute stroke patients could be used as a prognostic biomarker for stroke severity, functional outcome, and mortality. Methods Studies that investigated low T3 prognostic roles in acute stroke patients were sought from PubMed/Medline, Embase, and Cochrane databases through 11/23/2016. Pooled estimates of baseline stroke severity, mortality, and functional outcomes were assessed from fixed-effect (FE) and random-effects (RE) models. Results Eighteen studies met the inclusion criteria. Six studies (1,203 patients) provided data for low-T3 and normal-T3 patients and were meta-analyzed. Using the FE model, pooled results revealed low-T3 patients exhibited a significantly higher stroke severity, as assessed by the National Institutes of Health Stroke Scale (NIHSS) score at admission (mean difference = 3.18; 95%CI = 2.74, 3.63; I2 = 61.9%), had 57% higher risk of developing poor functional outcome (RR = 1.57; 95%CI = 1.33,1.8), and had 83% higher odds of mortality (Peto-OR = 1.83; 95%CI = 1.21, 1.99) compared to normal-T3 patients. In a univariate meta-regression analysis, the low-T3 and stroke severity association was reduced in studies with higher smokers% (slope = −0.11; P = 0.02), higher hypertension% (slope = −0.11; P = 0.047), older age (slope = −0.54; P = 0.02), or longer follow-up (slope = −0/17, P Conclusions Low-T3 syndrome in acute stroke patients is an effective prognostic factor for predicting greater baseline stroke severity, poorer functional outcome, and higher overall mortality risk.

Introduction Thyroid Function Tests (TFTs) are among the most commontly ordered tests. Significant overuse of TFTs can occur when instead of using a single TSH test to screen for thyroid disease a full panel (TSH plus FT4 and FT3) is ordered. The aim of our study was to evaluate the effectiveness of the application of a scientifically-established laboratory-controlled algorithm for TFTs to physician's orders for inpatients and to address potential pitfalls of such an approach. Materials and methods We collected and analyzed Laboratory Information System data of the TFTs performed between April 2009 and March 2016 in a 739-bed tertiary teaching hospital. Between April 2013 and March 2016, we applied a laboratory controlled algorithm for inpatient TFT assays after TSH and did not perform further tests, unless a justified bypass was requested by the treating physician. Results Algorithm application led to significant reductions of TFTs executed per TSH ordered. Compared to the four years preceding the intervention, executed FT4/TSH tests decreased from 93 to 18%, FT3/TSH from 92 to 18%, anti-TG/TSH from 18 to 4% and anti-TPO/TSH from 11 to 3%. Simultaneously, FT4, FT3, anti-TG, and anti-TPO tests ordered in outpatients also displayed a significant gradual decrease. Conclusions Hospital-based laboratories can safely apply a generally accepted TFTs algorithm on physician's orders without any compromise in diagnostic/therapeutic accuracy, thus achieving significant direct cost-reduction and increased physician awareness on current TFT ordering practices. Such an approach, combined with collaboration with ordering physicians, can safeguard patients from the consequences of low-value care practices.

Besides its well-known action to stimulate thyroid hormone release, thyrotropin mRNA is expressed within the brain, and thyrotropin and its receptor have been shown to be present in brain areas that control feeding and gastrointestinal function. Here, the hypothesis that thyrotropin acts on receptors in the hindbrain to alter food intake and/or gastric function was tested. Fourth ventricular injections of thyrotropin (0.06, 0.60, and 6.00 µg) were given to rats with chronic intracerebroventricular cannulas aimed at the fourth ventricle. Thyrotropin produced an acute reduction of sucrose intake (30 min). The highest dose of thyrotropin caused inhibition of overnight solid food intake (22 h). In contrast, subcutaneous administration of corresponding thyrotropin doses had no effect on nutrient intake. The highest effective dose of fourth ventricular thyrotropin (6 µg) did not produce a conditioned flavor avoidance in a standardized two-bottle test, nor did it affect water intake or gastric emptying of glucose. Thyrotropin injected in the fourth ventricle produced a small but significant increase in rectal temperature and lowered plasma levels of tri-iodothyronin but did not affect plasma levels of thyroxine. In addition, there was a tendency toward a reduction in blood glucose 2 h after fourth ventricular thyrotropin injection ( P = 0.056). In conclusion, fourth ventricular thyrotropin specifically inhibits food intake, increases core temperature, and lowers plasma levels of tri-iodothyronin but does not affect gastromotor function.

Tri-iodothyronine (T3) is the active form of thyroid hormone at the nuclear cell level. About 80% of tri-iodothyronine is produced by peripheral deiodination of thyroxine. The determination of the free form of this hormone is useful for the diagnosis and the follow-up of hyperthyroidism. In routine clinical laboratories, immunoassays remain the most used technics. After recalling the main points related to the physiological data, the authors point out the possible errors during the analytical steps of the assay.

Present study was aimed to investigate the effect of Neospora caninum seropositivity on testosterone and thyroid hormones levels of Iranian bulls. Two groups containing bulls with neosporosis and bulls without neosporosis were considered. To achieve bulls with neosporosis, N. caninum agglutination test (NAT) and ELISA was performed. Testosterone, thyroxin (T4) and tri-iodothyronine (T3) levels were measured and compared between infected and non-infected bulls. Testosterone of bulls with neosporosis was decreased but the difference was not significant. Serum T4 of bulls with neosporosis was decreased significantly but changes of serum T3 was not significant. The hypothalamic–pituitary–adrenal axis (HPA axis) impairment, direct effect of N. caninum and its antigens on testis function, interrelationships between thyroid dysfunction and hypogonadism, adaptive response of infected animals to N. caninum and occurrence of oxidative stress in testis due to the presence of Neospora may be the reasons of hormonal changes. The effect of N. caninum on hormonal changes remains incomplete at present and is an area for future research so as to better characterize the effects and mechanisms.

To determine the effect of grazing pasture that had a low selenium (Se) concentration on serum concentrations of triiodothyronine (T3) and thyroxine (T4), and erythrocyte glutathione peroxidase (GSH-Px) activity in dairy cows.Forty pregnant Friesian cows were grazed on pasture that contained 0.03-0.04 ppm Se on a dry matter (DM) basis. Two months before parturition, 20 cows were randomly selected and treated with 1 mg Se/kg bodyweight subcutaneously, as barium selenate (Group Se-S). The other group (Se-D) was not supplemented. Blood samples were taken before supplementation (-60 days) and 30, 60, 90, 180 and 270 days after parturition, for determination of concentrations of T3 and T4 in serum, and GSH-Px activity in erythrocytes.Erythrocyte GSH-Px activity in the Se-D group was60 U/g haemoglobin (Hb) throughout the experiment. Supplementation increased (p0.05) activities to130 U/g Hb throughout lactation. Mean serum concentrations of T4 in Se-D and Se-S cows increased from 23.7 (SEM 0.7) and 23.4 (SEM 0.8) nmol/L, respectively, in the prepartum period to 69.6 (SEM 0.1) and 67.6 (SEM 0.2) nmol/L, respectively, at 180 days of lactation (p0.01), and no effect of Se supplementation was evident. Serum concentrations of T3 in Se-D cows decreased (p0.05) from 1.6 (SEM 0.1) nmol/L prepartum to 1.0 (SEM 0.2) nmol/L at the beginning of lactation, and remained lower (p0.05) than those in the Se-S cows which did not decrease after calving and ranged from 1.9 (SEM 0.1) to 2.4 (SEM 0.2) nmol/L throughout lactation.Serum T3 concentrations decreased during early lactation in unsupplemented cows grazing pastures low in Se (0.03-0.04 ppm) and both serum T3 and erythrocyte GSHPx activities were consistently lower throughout lactation compared with Se-supplemented cows. Se supplementation had no effect on serum T4 concentrations.

Objective : The present study was designed to investigate variations in the levels of thyroid hormones (T3, T4) in breast and ovarian cancers patients. Methods : A total 120 subjects were recruited (without thyroid history) divided into three groups; A, B and C. Group A as control with healthy individuals. While group B and group C were consisting of breast cancer and ovarian cancer patient respectively. Blood samples (5 ml) were taken and analyzed to estimate the levels of serum T3 (tri-iodothyronine) and T4 (thyroxin) hormones. R esults : Statistically significant difference (P=0.000* and P=0.017*) was obtained among all groups. A significant increase in T3 (P=0.000*) and T4 (0.005*) levels was observed among breast cancer patients as compared to healthy controls. While for ovarian cancer patients conflicting results were found for T3 and T4 levels in the serum i.e. insignificant difference was found in T3 (P=0.209) and T4 (P=0.050) as compared to control. Our results showed that in the breast cancer and ovarian cancer patients the thyroid hormone (T3 and T4) level has been altered from the normal ranges as compared to the normal healthy individuals. Conclusion : We conclude that hyperthyroidism has profound effects on breast cancer and ovarian cancer cells proliferation.

Resume Malgre de nombreuses avancees dans le traitement pharmacologique de la depression, environ 30 % des patients deprimes resistent a au moins deux antidepresseurs. L’evolution peut alors conduire vers la chronicite, avec un impact considerable en termes de qualite de vie et de cout pour la societe. Dans cette revue critique de la litterature, nous resumons les donnees d’etudes controlees et de meta-analyses afin de mettre en relation la recherche actuelle avec la pratique clinique. Les strategies de potentialisation de l’antidepresseur incluent l’ajout d’un autre antidepresseur synergique, des antipsychotiques atypiques, du lithium, du pindolol, des psychostimulants, du pramipexole et des estrogenes. Dans l’ensemble, les strategies de potentialisation les plus efficaces permettent d’obtenir des taux de remission entre 25 et 50 % avec des NNT compris entre 3 et 8. Parmi ces options, les potentialisations par les APA, la T3 et le pramipexole semblent offrir le meilleur rapport benefice–risque. Toutes ces prescriptions se font hors AMM.

A primigravida was referred with hyperthyroidism in early pregnancy from longstanding Graves’ disease treated with propylthiouracil. She had selective elevation of free tri-iodothyronine (fT3) levels, low normal free tetra-iodothyronine (fT4) and suppressed thyroid-stimulating hormone (TSH). Given her symptoms of thyrotoxicosis and elevated TSH receptor antibodies, therapy was tailored towards maintaining clinical and biochemical euthyroidism. However the fetus developed a goitre secondary to hypothyroidism. This case highlights the dilemmas in managing maternal T3 toxicosis while aiming for a high normal fT4 to prevent fetal hypothyroidism including the role of fetal ultrasound monitoring and amniocentesis.

Tri-iodothyronine (T3) has been shown to be a hepatic mitogen. The aim of this study was to evaluate the effect of T3 on liver regeneration after 50% partial liver transplantation (pLT) in rats.Immediately after pLT, a single dose of T3 (4 mg/kg body weight) was administered. Liver/body weight ratio (LBWR), hepatocyte proliferation (Ki-67), biochemical parameters, and changes in cell cycle related proteins were evaluated.T3 promoted liver regeneration as shown by an increased liver/body weight ratio and Ki-67 proliferation index after pLT. On the transcriptional level, T3-treated rats had an increased expression of cyclin D1 and cyclin A as demonstrated by real time RT-PCR and Western blot.Exogenous administration of T3 significantly improved liver regeneration after pLT, and therefore it may represent a promising strategy to improve the clinical outcome after living donor liver transplantation in the future.

The comparative effects of equimolar doses of thyroxine (T4) and tri-iodothyronine (T3) and of the inhibition of peripheral monodeiodination were studied on feather regeneration and moult in thyroidectomized and intact adult male spotted munia (Lonchura punctulata). T4 was significantly more effective than T3 at all dose levels in inducing feather regeneration in thyroidectomized birds. Suppression of mono-deiodination by iopanoic acid (IOP) was not accompanied by a suppression of T4-induced feather regeneration in thyroidectomized birds and IOP alone was without effect in thyroidectomized birds. Long-term treatment of intact birds with IOP accelerated the process of moulting by about 3 months. These findings question the prevailing concept that T3 is the finally active biological compound and T4 a mere precursor. Journal of Endocrinology (1993) 137, 265–270

We have studied the effects of the administration of GH on plasma levels and peripheral production of tri-iodothyronine (T3) from thyroxine (T4) in thyroidectomized male Wistar rats given a continuous i.v. infusion of T4 (1 μg/100 g body weight per day) and GH (120 μg per day) for 3 weeks. Tracer doses of 131I-labelled T3 and 125I-labelled T4 were added to the infusion. At isotopic equilibrium (10 days after the addition of 125I-labelled T4) the rats were bled and perfused. The plasma appearance rate for T3 was higher (10·6±1·3 vs 8·4 ± 2·8 pmol/h per 100 g body weight, P = 0·05) and plasma TSH was lower (246±24 vs 470±135 pmol/l, P3 in liver (12·3 ±2·8 vs 5·5 ± 1·7 pmol/g wet weight, PP P< 0·01) was higher than in controls, mainly as a result of an increased local production of T3 from T4, but plasma-derived T3 was also higher in most organs. We found an increased intracellular T3 concentration in the pituitary which may be responsible for the lower plasma TSH concentration in the GH-treated rats. Since the increase in locally produced T3 is found particularly in liver, kidney and pituitary, typical organs that express 5′-deiodinase activity, we suggest that GH acts on thyroid hormone metabolism by stimulating type-I deiodinase activity. Journal of Endocrinology (1992) 133, 45–49

1. The nodular phase of hepatic premalignancy was induced in male Fischer 344 rats by the administration of diethylnitrosamine, 200 mg/kg i.p., followed by promotion utilizing the Solt-Farber promoting regime. 2. Relative to the situation in normal non-treated control rats: the activity of gamma-glutamyltranspeptidase was found to be increased 9.42-fold in homogenate and 7.33-fold in plasma membrane fractions prepared from the livers of saline-injected control rats; and 81.37-fold in homogenates and 91.92-fold in plasma membranes prepared from the livers of diethylnitrosamine-injected rats; plasma levels of total T3 and total T4 were found to be decreased 42.06 and 47.45% in saline-injected control rats and 88.7 and 83.2% in diethylnitrosamine-injected rats, respectively. 3. An early pre-nodular phase of hepatic premalignancy was produced in young immature and mature adult male Fischer 344 rats by the administration of diethylnitrosamine, 75 mg/kg, without subsequent application of the promotion regime. 4. Relative to the situation in control rats: the activity of gamma-glutamyltranspeptidase was found to be increased in liver homogenates prepared from diethylnitrosamine-treated rats, 1.62-fold in young immature rats 1.20-fold in mature adult rats; plasma levels of total T3 were found to be reduced in diethylnitrosamine-treated rats, 28% in young immature rats 9% in mature adult rats. 5. Treatment of diethylnitrosamine-injected young immature male Fischer 344 rats at the prenodular phase of hepatic premalignancy with tri-iodothyronine at 0.005 micrograms/kg s.c. daily for 7 days reversed the diethylnitrosamine-induced increase in liver homogenate gamma-glutamyltranspeptidase activity and the decrease in plasma total T3, restoring these parameters to normal levels.(ABSTRACT TRUNCATED AT 250 WORDS)

The relationship between serum cholesterol, thyrotropin, thyroxine and tri-iodothyronine was investigated in 1018 female patients over 40 years of age with suspected hypothyroidism. The correlation between serum thyrotropin and cholesterol ( r = 0.398) and between thyroxine and cholesterol ( r = — 0·217) were both highly significant ( P < 0·001), but the correlation between tri-iodothyronine and cholesterol ( r = −0·011) was not significant. Only in patients with a serum thyrotropin in excess of 40 mU/L was there a clinically appreciable increase in the serum cholesterol. In 139 patients treated for hypothyroidism by thyroxine replacement there was a highly significant correlation ( P < 0·001) between the decrease in serum thyrotropin and cholesterol ( r = 0·593). The correlation between increase in serum thyroxine and decrease in cholesterol ( r = — 0·401) was also highly significant (P < 0·001), but there was an even stronger correlation between the increase in serum tri-iodothyronine and the decrease in serum cholesterol ( r = — 0·529).

Previously, we have shown that low-dose tri-iodothyronine (T3) increases food intake in rodents. This randomised, double-blind, placebo-controlled study aimed to investigate the effects of low-dose T3 on food intake in normal body weight individuals. However, despite an elevation in fT3 comparable to our earlier studies, administration of low-dose T3 in the fasted state did not stimulate food intake in man.

Background and Aim: Liver and thyroid hormones are powerfully correlated so thyroid hormone abnormalities are seen in patients of liver diseases We evaluated serum thyroid hormone levels in chronic hepatitis C cirrhotic patients with and without hepatic encephalopathy. Patients and Methods: Our study was carried out on one hundred patients with chronic hepatitis C (CHC) related liver cirrhosis (66 male and 34 female). they were divided to three groups: Group I which included 40 patients proved to have liver cirrhosis due to CHC with hepatic encephalopathy (26 male and 14 female), Group II which included 60 patients proved to have liver cirrhosis due to CHC without hepatic encephalopathy (40 males and 20 females), Group III which included 20 healthy subjects was taken as control group (12 males and 8 females). Free tri-iodothyroinine (FT3), free thyroxine (FT4), total T3, total T4 and thyrotropine stimulating hormone (TSH) were tested. Results: (Group I) and (Group II) showed a significant decrease in T3 and FT3 levels compared to controls (Group III) whereas there was no difference in serum T4, TSH and FT4 levels. all (Group I) had significantly reduced levels of T3 and FT3 compared to (Group II), whereas there was no difference in T4, FT4 and TSH levels. Conclusion: Patients with chronic CHC have significant lower serum FT3 and T3. Patients with hepatic encephalopathy were found to have exceedingly low serum T3 and FT3 levels. Depressed serum T3 and FT3 levels, together with a prolonged prothrombin time and hypo-albuminemia, therefore appear to be characteristic of decompensated cirrhotic patients prone to develop hepatic encephalopathy.

Background and aim Liver and thyroid hormones are powerfully correlated; thus, thyroid hormone abnormalities are found in patients with liver diseases. We evaluated serum thyroid hormone levels in chronic hepatitis C (CHC) cirrhotic patients with and without hepatic encephalopathy. Patients and methods Our study was carried out on 100 patients with CHC-related liver cirrhosis (66 men and 34 women). They were divided into three groups: group I, which included 40 patients proved to have liver cirrhosis because of CHC with hepatic encephalopathy (26 men and 14 women), group II, which included 60 patients proved to have liver cirrhosis because of CHC without hepatic encephalopathy (40 men and women), and group III, the control group, which included 20 healthy individuals (12 men and eight women). Free tri-iodothyronine (FT3), free thyroxine (FT4), total T3, total T4, and thyrotropine-stimulating hormone (TSH) were tested. Results Group I and group II showed a significant decrease in T3 and FT3 levels compared with the controls (group III), whereas there was no difference in serum T4, TSH, and FT4 levels. All the patients (group I) had significantly reduced levels of T3 and FT3 compared with group II, whereas there was no difference in T4, FT4, and TSH levels. Conclusion Patients with CHC cirrhosis have significantly lower serum FT3 and T3. Patients with hepatic encephalopathy were found to have very low serum T3 and FT3 levels. Decreased serum T3 and FT3 levels, together with a prolonged prothrombin time and hypoalbuminemia, therefore appear to be characteristic of decompensated cirrhotic patients prone to developing hepatic encephalopathy.

Background: Tri-iodothyronine (T3) has been shown to be a hepatic mitogen. We investigated whether exogenous application of T3 improves liver regeneration after 70% partial hepatectomy (PH) and confers a survival advantage after 90% subtotal hepatectomy (SH) in rats and whether this is associated with the stimulation of angiogenesis. Methods: Rats were subjected to PH or SH 10 days after injection of a single dose of T3. Liver body weight ratio (LBR), hepatic proliferation (Ki-67), biochemical markers as well as vascular endothelial growth factor (VEGF) expression were assessed by immunohistochemistry. Gene expression of pathogenic relevant genes was determined by customized cDNA arrays and quantitative RT-PCR. Results: T3-treated rats showed an increased LBR and Ki-67 index after PH and SH, which reached statistical significance compared to placebo-treated rats (p < 0.05). On the transcriptional level, T3-treated rats had an increased expression of VEGF as demonstrated by immunohistochemistry, which was associated with a higher expression of its receptor Flt-1. Conclusions: Exogenous administration of T3 ameliorates liver regeneration after 70% PH and 90% SH, possibly due to stimulation of angiogenesis. Therefore, its clinical use might be of interest due to its excellent general practicability.

Antibodies to purified recombinant PDHKII were used for ELISAs of PDHKII in mitochondrial extracts. In liver, hyperthyroidism elicited a 2.3‐fold increase in PDHK activity (P

A coating procedure that could provide immobilization of antibodies, with increased binding capacity, that is cost effective, simple, robust, and appropriate for production scale application, is described. This coating approach of T3 antibodies to the polystyrene tubes has been systematically investigated to determine its utility for the development of coated tube Radioimmunoassay (RIA) for T3 in human serum. Further, the results obtained by the developed coating procedure are found to be comparable with those obtained by the "gold standard," the liquid phase RIA for T3. The coating procedure is completed in three major steps, each step involving an overnight incubation. The normal rabbit gamma-globulins are physically adsorbed onto the polystyrene tubes and incubated. After washing, a second antibody (goat anti-rabbit antiserum) is added and incubated. To this antigen specific antibody is added (T3 antibody produced in rabbit) and further incubated. Finally, the non-specific sites on the tubes are saturated by the blocking solution. The concentration of normal rabbit globulin, titers of second antibody and T3 antibody, and time required for coating are optimized to arrive at a suitable coating protocol. The coated tubes were evaluated for precision, reproducibility, and stability. Various parameters such as total reaction volume, incubation time and temperature, total number and volume of washings, concentration of 8-anilino-1-naphthalene sulfonic acid (ANS), and quantity of tracer per tube are optimized to arrive at a suitable standard curve. The optimized assay is validated for the quality control parameters such as intra- and inter-assay variations, recovery, and parallelism. The developed coated tubes assay had an assay range of 0.3-4.8 ng/mL with a sensitivity of 0.3 ng/mL at 90% B/B0. Batch to batch variation in coating was10%. The coated tubes were stable up to 1 year, which is adequate for production scale.

The cardiovascular system is an important target for thyroid hormones. The present study evaluates the changes affecting thyroid hormone metabolism during and 6 days after coronary artery bypass and their relationship with the post-operative outcome of the patients. Thirty-three patients were enrolled in the study; their thyroid hormone profiles were determined at 13 sampling points during surgery and for 6 days afterwards. Serum total tri-iodothyronine (T3) and free T3 (FT3) concentrations decreased significantly after surgery (P

Swat valley is famous for its high production of agriculture crops. These crops are under constant attacks by different pests and use of pesticides has become very crucial for the control of these pests. Pesticides are toxic substances used to kill organisms which are competing humans for food and may also pose risk to humans. The current study was performed to investigate the effects of pesticides on blood circulating hormones (Thyroid stimulating hormone [TSH], Tri-iodothyronine [ T3 ], and haematological parameters of agriculture workers. A total of 30 blood samples were collected from male agriculture workers who have been exposed to pesticides in crop fields for a long period of time, while 30 blood samples have been taken from the group of people in meanwhile who were not dealing with pesticides. The blood samples were collected in a randomized manner. The haematological parameters and hormones levels were determined using standard methods. The mean and standard deviation values for each parameter were calculated using statistical software Minitab version 16 . Paired t-test was used to find the significance of data and p-value of ≤ 0.05 at 95% confidence interval was considered as the significant. The analysis showed a decrease in the level of TSH and an increase in the level of T3 hormone in group of people who have been exposed to pesticides in comparison to the other group of people who have not been exposed to pesticides (control). The haematological parameters did not show a uniform pattern upon exposures to pesticides. The white blood cells and platelets were the most affected parameters. This preliminary study would be helpful to determine the future risk of diseases in agriculture workers.

The direct effect of Tri-iodothyronine (T(3): 0.1-100 nM) on protein turnover was studied using primary cultures of Sertoli cells isolated from immature piglet testis. The results demonstrate that T(3) significantly increases protein synthesis without altering the protein degradation rate. These data and previous ones, showing the presence of specific T(3) receptors in Sertoli cell nuclei, indicate that T(3) plays a fundamental role in the early regulation of porcine Sertoli cell growth and maturation.

Thyroid hormones are extremely important for development of the fetal central nervous system. Thyroidectomy results in severe hypothyroidism. In this study two levels of maternal hypothyroidism were reached by administration of different amounts of thyroxine (T4) and 3,5,3'-tri-iodothyronine (T3) to thyroidectomized pregnant rats. We examined the production, distribution and transport of T4 and T3 by performing a kinetic experiment (three-compartment analysis) with intact and thyroidectomized near-term pregnant rats which received either very low (Tx + lowTH) or normal (Tx + TH) doses of T4 and T3. Despite administration of normal doses of thyroid hormones, plasma TSH was still elevated in the Tx + TH rats, meaning that these rats were still mildly hypothyroid. The Tx + lowTH rats were markedly hypothyroid, the plasma T4 and T3 levels being very low. In the mildly hypothyroid rats the transport of T4 from plasma to the fast pool and vice versa was decreased compared with intact near-term pregnant rats. This could imply that much less T4 is transported to the feto-placental compartment. Liver type I deiodinase was decreased, resulting in lowered plasma T3 values. In the markedly hypothyroid rats all pools and rates of transport of T4 and T3 were greatly decreased. In conclusion, even mild hypothyroidism, despite normal plasma T4 values, results in significant changes, especially in maternal T4 transport. We suggest that even mild maternal hypothyroidism will have a negative effect on the availability of maternal T4 for fetuses.

Background: Tri-iodothyronine (T3) is the main active hormone, and 20% of this is derived from the thyroid gland and 80% is from the peripheral tissue according to 5'-monodeiodination of thyroxine (T4). In the previous studies, normal T3 levels were achieved with traditional levothyroxine (LT4) therapy alone in athyreotic patients, but there has been no data about the factors influencing peripheral conversion of LT4. The aim of this study was to determine the factor(s) influencing peripheral conversion of LT4 to T3 in athyreotic patients during LT4 replacement. Methods: The patients who underwent total-thyroidectomy for any cause, and mostly for thyroid cancers, at Asan Medical Center between 2000 and 2008 were enrolled. The free T4, T3 and thyroid stimulating hormone (TSH) levels and age, gender, weight, height, body mass index (BMI) and the T4 dose were measured. Only patients with normal ranges of free T4 and TSH were included in the analysis. Results: A total of 143 patients were enrolled. The mean T3, free T4 and TSH levels were 143.7 ng/dL, 1.4 ng/dL and 1.6 /mL, respectively. The mean weight and BMI were 62.9 kg and 24.6 kg/, respectively. We divided them into two groups according to the serum T3 level and we compared the characteristics of the groups. There were no differences in age, the gender distribution, the T4 dose/weight and the BMI between the low T3 group (T3 122 ng/dL, n = 14) and the normal T3 group (T3 > 122 ng/dL, n = 129). In the low T3 group, the mean body weight was significantly lower than that of the normal T3 group ( vs. , respectively, P = 0.025). Conclusion: Lean body mass seems to be an important factor for determining the peripheral conversion of T4 to T3 in human. This suggest that a combination of T3/T4 is better than T4 only when we treat the patients with hypothyroidism and who have a negligible amount of functioning thyroid tissue, if they have a low lean body mass.

We investigated the uptake of l-tri-iodothyronine (T3) by cultured human trophoblast cells. Uptake was time-dependent, initially linear and approaching equilibrium after 60 min with an approximate half-time of 13 ± 4·5 min (mean ± s.e.m., n = 4). It had a non-saturable component accounting for about 50% of total uptake. We demonstrated a single saturable T3 uptake mechanism with a calculated Michaelis constant (Km) of 755 ± 145 nmol/l (n = 11–13) and a corresponding maximum velocity of 28·8 ± 5·3 pmol/min per mg protein (n = 11–13). The Km value was similar to those reported in other tissues. Journal of Endocrinology (1992) 133, 483–486

The influence of TRH and TSH injections on plasma concentrations of tri-iodothyronine (T3) and thyroxine (T4) was investigated in neonatal (injection within 0·5 h after delivery) and growing lambs and in normal, pregnant and lactating adult ewes (all 2 years old and originating from Suffolk, Milksheep and Texal cross-breeds). Neonatal lambs had higher levels of T3, T4 and GH compared with all other groups, whereas prolactin and TSH were higher in lactating ewes. In all animals, injections of TRH increased plasma concentrations of prolactin and TSH after 15 min but not of GH at any time. Small increases in T3 and T4 were observed in neonatal lambs, without any effect on the T3 and T4 ratio, after prolactin administration, whereas prolactin did not influence plasma concentrations of T3 or T4 in all other experimental groups. Similar results for thyroid hormones were obtained after TRH or TSH injections. It was therefore concluded that the effects observed after TRH challenge were mediated by the release of TSH. With the possible exception of neonatal lambs, plasma concentrations of T3 after administration of TRH or TSH were always increased before those of T4; the increase in T3 occurred within 0·5–1 h compared with 2–4 h for T4 in all experimental groups. This resulted in an increased ratio of plasma T3 to T4 up to 4 h after injection. It is concluded that, in sheep, TRH and TSH preferentially release T3 from the thyroid gland probably by a stimulatory effect of TSH on the intrathyroidal conversion of T3 to T4. Journal of Endocrinology (1992) 132, 93–100

Background: Cardiopulmonary bypass produces a state of functional hypothyroidism characterized by low levels of circulating tri-iodothyronine (T3). Theoretically, supplementing T3 should result in improved hemodynamics as well as patients’ outcome. The aim of the present study was to determine whether pretreatment with single oral T3 could prevent serum T3 reduction, and improve hemodynamics and clinical outcome. Methods: Forty-seven patients undergoing valvular heart surgery were included in the study. Patients were randomly assigned into two groups (T = T group; C = control group) the day before surgery and received single oral T3 40 μg or placebo before operation. Blood samples were collected for determination of serum levels of total T3, T4 and TSH before administration of oral T3 or placebo (baseline), 1, 6 and 18 hour after weaning of cardiopulmonary bypass. Hemodynamic parameters and medication were recorded during the intraoperative period and throughout the first 24 h after arrival at the intensive care unit. Results: T3 levels were significantly higher in the T group 1 hr after weaning of cardiopulmonary bypass. T3 levels in the T group were all maintained within the normal range throughout the study period, whereas it was decreased to below normal level in the C group at 18 hr after weaning of cardiopulmonary bypass. In the T group, vasoactive agent requirements were reduced during and after cardiopulmonary bypass. Conclusions: Pretreatment with single oral T3 prevented the reduction in T3 level after valvular heart surgery, with subsequent reduction in vasoactive agent requirement. (Korean J Anesthesiol 2009; 56: 535～42)

The majority of patients who ingest thyroxine accidentally or deliberately remain asymptomatic. Sinus tachycardia, tremor, anxiety, irritability, hyperactivity, fever, sweating and diarrhoea occur commonly after a substantial overdose of thyroxine or tri-iodothyronine. Propranolol (40 mg t.d.s.) for 5 days is very effective in controlling symptoms.

AIM: To investigate the role of tri-iodothyronine supplement in protecting gut barrier in septic rats. METHODS: Twenty-two rats were randomized into three groups: sham group (n = 6), sepsis group (n = 8), and sepsis plus tri-iodothyronine (T3) group (n = 8). Septic rat model was established through cecal ligation and puncture (CLP). After 5 h, sham and sepsis groups received saline, and the remaining group received T3 intraperitoneally. Twenty-one hours after CLP, intestinal permeability and serum free T3 and T4 were measured with fluorescence spectrophotometer and by radioimmunoassay, respectively. Intestinal ultrastructure and histologic morphology were observed under transmission electron microscopy (TEM) and light microscopy, respectively. RESULTS: After 21 h, septic symptoms and signs in sepsis plus T3 group were milder than those in sepsis group. Serum FT3 or FT4 concentration in sepsis group was lower than that in sham group (1.59 ± 0.20, 3.41 ± 2.14 pmol/L vs 3.44 ± 1.40,9.53 ± 3.39 pmol/L, P < 0.05), and FT3 concentration in sepsis plus T3 group (3.40 ± 1.65 pmol/L, P < 0.05) was corrected. Portal concentration of fluorescein isothiocyanate-dextran (FITC-D) in sepsis group (2.51 ± 0.56 mg/L) was higher than that in sham group (1.22 ± 0.21 mg/L) (P < 0.01), and in sepsis plus T3 group (1.68 ± 0.38 mg/L) it was decreased significantly (P < 0.01). TEM and light microscopy showed that T3 supplement preserved well ultrastructure and morphology of intetinal mucosa in septic rats. CONCLUSION: Tri-iodothyronine supplement protects gut barrier in septic rats.

Insulin, thyroxine and tri-iodothyronine concentrations were measured in samples of blood from 175 Friesian bulls, aged between 2 and 7 years, which were being progeny-tested for milk production. Least squares regression coefficients were estimated for these hormone levels on time of day and time after feed at sampling and age of bull. Correlations between hormone levels and Improved Contemporary Comparisons of the bull, a measure of his daughters' milk production, did not differ significantly from zero, suggesting that simple spot estimates of levels of these hormones in bulls would not supply useful predictors of daughters' production.