scholarly journals Applicability of thyroxine measurements and ultrasound imaging in evaluations of thyroid function in turtles

2019 ◽  
Vol 63 (2) ◽  
pp. 267-273
Author(s):  
Joanna Pajdak-Czaus ◽  
Elżbieta Terech-Majewska ◽  
Dagmara Będzłowicz ◽  
Martyn Mączyński ◽  
Wioletta Krystkiewicz ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Gland ◽  
Thyroid Hormones ◽  
Thyroid Function ◽  
Ultrasound Imaging ◽  
Ultrasound Examination ◽  
Plasma Concentrations ◽  
Physiological Homeostasis ◽  
Low Levels ◽  
And Function

AbstractIntroduction: The thyroid and parathyroid glands play a major role in maintaining physiological homeostasis in all vertebrates. Reptiles have plasma concentrations of thyroid hormones far lower than mammals. Low levels of these hormones in reptiles impede thyroid hormone detection with assays designed for the higher levels of mammals. The aim of this study was to explore teaming this with ultrasound imaging of the thyroid to appraise glandular function. Material and Methods: Thyroid function of four pond sliders was evaluated based on the results of T4 analyses and ultrasound. Results: The concentrations of T4 varied considerably between the examined animals from <9 nmol/L to >167.3 nmol/L. Ultrasound examination revealed uniform echogenicity and a smooth outline of the thyroid gland in all animals. Conclusion: Monitoring of thyroid function based on T4 and electrolyte concentrations is helpful in assessing the health and living conditions of reptiles, which is important in veterinary practice but problematic. Ultrasound examinations are useful in diagnosing changes in gland structure, such as tumours and goitres, and a combination of both methods supports comprehensive assessments of the anatomy and function of the thyroid gland.

Iodide Metabolism and Effects

2020 ◽  
pp. 25-33
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Gland ◽  
Thyroid Hormones ◽  
Dietary Supplement ◽  
Thyroid Function ◽  
Thyroid Stimulating Hormone ◽  
Hormone Synthesis ◽  
Serum Tsh ◽  
Tsh Stimulation ◽  
Sensitive Marker

Iodine (I2) is essential in the synthesis of thyroid hormones T4 and T3 and functioning of the thyroid gland. Both T3 and T4 are metabolically active, but T3 is four times more potent than T4. Our body contains 20-30 mg of I2, which is mainly stored in the thyroid gland. Iodine is naturally present in some foods, added to others, and available as a dietary supplement. Serum thyroid stimulating hormone (TSH) level is a sensitive marker of thyroid function. Serum TSH is increased in hypothyroidism as in Hashimoto's thyroiditis. In addition to regulation of thyroid function, TSH promotes thyroid growth. If thyroid hormone synthesis is chronically impaired, TSH stimulation eventually may lead to the development of a goiter. This chapter explores the iodide metabolism and effects of Hashimoto's disease.

scholarly journals The association of TSH and thyroid hormones with lymphopenia in bacterial sepsis and COVID-19

2021 ◽  
Author(s):  
Inge Grondman ◽  
Aline H de Nooijer ◽  
Nikolaos Antonakos ◽  
Nico A F Janssen ◽  
Maria Mouktaroudi ◽  
...  
Keyword(s):  
Thyroid Hormones ◽  
Thyroid Function ◽  
Plasma Concentrations ◽  
Bacterial Sepsis ◽  
Free T4 ◽  
Reactive Protein ◽  
Severe Infections ◽  
Absolute Lymphocyte Counts ◽  
And Function

Abstract Context Lymphopenia is a key feature of immune dysfunction in patients with bacterial sepsis and COVID-19 and associated with poor clinical outcomes, but the cause is largely unknown. Severely ill patients may present with thyroid function abnormalities, so-called non-thyroidal illness syndrome (NTIS), and several studies have linked TSH and the thyroid hormones thyroxine (T4) and triiodothyronine (T3) to homeostatic regulation and function of lymphocyte populations. Purpose To test the hypothesis that abnormal thyroid function correlates with lymphopenia in patients with severe infections. Methods Retrospective analysis of absolute lymphocyte counts, circulating TSH, T4, free T4 (FT4), T3, albumin and inflammatory biomarkers was performed in two independent hospitalized study populations: bacterial sepsis (n=224) and COVID-19 patients (n=161). A subgroup analysis was performed in patients with severe lymphopenia and normal lymphocyte counts. Results Only T3 significantly correlated (rho=0.252) with lymphocyte counts in patients with bacterial sepsis and lower concentrations were found in severe lymphopenic compared to non-lympopenic patients (n=56 per group). Severe lymphopenic COVID-19 patients (n=17) showed significantly lower plasma concentrations of TSH, T4, FT4 and T3 compared to patients without lymphopenia (n=18), and demonstrated significantly increased values of the inflammatory markers interleukin-6, C-reactive protein and ferritin. Remarkably, after one week follow-up, the majority (12/15) of COVID-19 patients showed quantitative recovery of their lymphocyte numbers, while TSH and thyroid hormones remained mainly disturbed. Conclusion Abnormal thyroid function correlates with lymphopenia in patients with severe infections, like bacterial sepsis and COVID-19, but future studies need to establish whether a causal relationship is involved.

THYROID DYSFUNCTION IN PATIENTS WITH CHRONIC KIDNEY DISEASE: THE STATE OF THE PROBLEM AND THE WAYS OF SOLVING

2018 ◽  
Vol 22 (4) ◽  
pp. 40-49 ◽  
Author(s):  
A. R. Volkova ◽  
O. D. Dygun ◽  
B. G. Lukichev ◽  
S. V. Dora ◽  
O. V. Galkina
Keyword(s):  
Chronic Kidney Disease ◽  
Thyroid Gland ◽  
Kidney Disease ◽  
Thyroid Hormones ◽  
Thyroid Function ◽  
Thyroid Dysfunction ◽  
The Body ◽  
Type I ◽  
Low T3 ◽  
Iodine Excretion

Disturbance of the thyroid function is often detected in patients with different profiles. A special feature of patients with chronic kidney  disease is the higher incidence of various thyroid function  disturbances, especially hypothyroidism. It is known that in patients  with chronic kidney disease (CKD) iodine excretion from the body is  violated, since normally 90% of iodine is excreted in urine.  Accumulation of high concentrations of inorganic iodine leads to the  formation of the Wolf-Chaikoff effect: suppression of iodine  organization in the thyroid gland and disruption of the thyroid  hormones synthesis. Peripheral metabolism of thyroid hormones is  also disturbed, namely, deiodinase type I activity is suppressed and  peripheral conversion of T4 into T3 is inhibited (so-called low T3  syndrome). Therefore, patients with CKD are often diagnosed with  hypothyroidism, and the origin of hypothyroidism is not always  associated with the outcome of autoimmune thyroiditis. The article  presents an overview of a large number of population studies of  thyroid gland dysfunction in patients with CKD, as well as  experimental data specifying the pathogenetic mechanisms of  thyroid dysfunction in patients with CKD. Therapeutic tactics are still  not regulated. However, in a number of studies, replacement therapy with thyroid hormones in patients with CKD had some advantages.

scholarly journals AMIODARON SEBAGAI OBAT ANTI ARITMIA DAN PENGARUHNYA TERHADAP FUNGSI TIROID

2013 ◽  
Vol 3 (2) ◽  
Author(s):  
Starry H. Rampengan
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Gland ◽  
Thyroid Function ◽  
Hormone Replacement ◽  
Type I ◽  
Peripheral Tissues ◽  
Hormone Synthesis ◽  
Thyroid Hormone Metabolism ◽  
Serum T4 ◽  
Life Threatening

Abstract: Amiodarone is a highly effective anti-arrhythmic agent used in certain arrhythmias from supraventricular tachycardia to life-threatening ventricular tachycardia. Its use is associated with numerous side-effects that could deteriorate a patient’s condition. Consequently, a clinician should consider the risks and benefits of amiodarone before initiating the treatment.The thyroid gland is one of the organs affected by amiodarone. Amiodarone and its metabolite desethyl amiodaron induce alterations in thyroid hormone metabolism in the thyroid gland, peripheral tissues, and probably also in the pituitary gland. These actions result in elevations of serum T4 and rT3 concentrations, transient increases in TSH concentrations, and decreases in T3 concentrations. Both hypothyroidism and hyperthyroidism are prone to occur in patients receiving amiodarone. Amiodarone-induced hypothyroidism (AIH) results from the inability of the thyroid to escape from the Wolff-Chaikoff effect and is readily managed by either discontinuation of amiodarone or thyroid hormone replacement. Amiodarone-induced thyrotoxicosis (AIT) may arise from either iodine-induced excessive thyroid hormone synthesis (type I, usually with underlying thyroid abnormality), or destructive thyroiditis with release of preformed hormones (type II, commonly with apparently normal thyroid glands). Therefore, monitoring of thyroid function should be performed in all amiodarone-treated patients to facilitate early diagnosis and treatment of amiodarone-induced thyroid dysfunction. Key words: Amiodarone, thyroid function, side effect, management, monitoring.     Abstrak: Amiodaron adalah obat antiaritmia yang cukup efektif dalam menangani beberapa keadaaan aritmia mulai dari supraventrikuler takikardia sampai takikardia ventrikuler yang mengancam kehidupan. Namun penggunaan obat ini ternyata menimbulkan efek samping pada organ lain yang dapat menimbulkan perburukan keadaan pasien. Sehingga, dalam penggunaan amiodaron, klinisi juga harus menimbang keuntungan dan kerugian yang ditimbulkan oleh obat ini. Salah satu organ yang dipengaruhi oleh amiodaron adalah kelenjar tiroid. Amiodaron dan metabolitnya desetil amiodaron memengaruhi hormon tiroid pada kelenjar tiroid, jaringan perifer, dan mungkin pada pituitari. Aksi amiodaron ini menyebabkan peningkatan T4, rT3 dan TSH, namun menurunkan kadar T3. Hipotiroidisme dan tirotoksikosis dapat terjadi pada pasien yang diberi amiodaron. Amiodarone-induced hypothyroidism (AIH) terjadi karena ketidakmampuan tiroid melepaskan diri dari efek Wolff Chaikof, dan dapat ditangani dengan pemberian  hormon substitusi T4 atau penghentian amiodaron. Amiodarone-induced thyrotoxicosis (AIT) terjadi karena sintesis hormon tiroid yang berlebihan yang diinduksi oleh iodium (tipe I, biasanya sudah mempunyai kelainan tiroid sebelumnya) atau karena tiroiditis destruktif yang disertai pelepasan hormon tiroid yang telah terbentuk (tipe II, biasanya dengan kelenjar yang normal). Pemantauan fungsi tiroid seharusnya dilakukan pada semua pasien yang diberi amiodaron untuk memfasilitasi diagnosis dan terapi yang dini terjadinya  disfungsi tiroid yang diinduksi amiodaron. Kata Kunci: Amiodaron, fungsi tiroid, efek samping, penanganan, pemantauan.

scholarly journals An unusual case of struma ovarii

2021 ◽  
Vol 2021 ◽  
Author(s):  
Viktoria F Koehler ◽  
Patrick Keller ◽  
Elisa Waldmann ◽  
Nathalie Schwenk ◽  
Carolin Kitzberger ◽  
...  
Keyword(s):  
Thyroid Gland ◽  
Thyroid Hormones ◽  
Thyroid Function ◽  
Adnexal Mass ◽  
Thyroid Tissue ◽  
Reference Interval ◽  
Struma Ovarii ◽  
Radioiodine Uptake ◽  
Diagnostic Pitfalls ◽  
Biochemical Features

Introduction Struma ovarii is a teratoma of the ovaries predominantly composed of thyroid tissue. Hyperthyroidism associated with struma ovarii is rare, occurring in approximately 8% of cases. Due to the rarity of struma ovarii, available data are limited to case reports and small case series. Methods and results We report on a 61-year-old female patient with known Hashimoto’s thyroiditis on levothyroxine replacement therapy for years with transition to clinical and biochemical hyperthyroidism despite antithyroid medication with carbimazole (10 mg/day), new diagnosis of urothelial carcinoma and an adnexal mass suspicious of ovarian cancer. The patient underwent resection of the adnexal mass and histopathology revealed a mature teratoma predominantly composed of thyroid tissue showing high levels of sodium iodide symporter protein expression. Following struma ovarii resection and disappearance of autonomous production of thyroid hormones, the patient developed hypothyroidism with severely decreased thyroid hormone levels fT4 and fT3 (fT4 0.4 ng/dL, reference interval 0.9–1.7 and fT3 < 1.0 pg/mL, reference interval 2.0–4.4). This has previously been masked by continued thyroid-stimulating hormone suppression due to long-term hyperthyroidism pre-surgery indicating secondary hypothyroidism, in addition to primary hypothyroidism based on the known co-existing chronic lymphocytic thyroiditis of the orthotopic thyroid gland. Levothyroxine administration was started immediately restoring euthyroidism. Conclusion This case illustrates possible diagnostic pitfalls in a patient with two concurrent causes of abnormal thyroid function. Learning points Struma ovarii is an ovarian tumor containing either entirely or predominantly thyroid tissue and accounts for approximately 5% of all ovarian teratomas. In rare cases, both benign and malignant struma ovarii can secrete thyroid hormones, causing clinical and biochemical features of hyperthyroidism. Biochemical features of patients with struma ovarii and hyperthyroidism are similar to those of patients with primary hyperthyroidism. In such cases, thyroid scintigraphy should reveal low or absent radioiodine uptake in the thyroid gland, but the presence of radioiodine uptake in the pelvis in a whole body radioiodine scintigraphy. We give advice on possible diagnostic pitfalls in a case with two simultaneous causes of abnormal thyroid function due to the co-existence of struma ovarii.

scholarly journals Synthesis and Metabolism of Thyroid Hormones Is Preferentially Maintained in Selenium-Deficient Transgenic Mice

Endocrinology ◽  
2006 ◽  
Vol 147 (3) ◽  
pp. 1306-1313 ◽  
Author(s):  
Lutz Schomburg ◽  
Cornelia Riese ◽  
Marten Michaelis ◽  
Emine Griebert ◽  
Marc O. Klein ◽  
...  
Keyword(s):  
Thyroid Gland ◽  
Thyroid Hormones ◽  
Knockout Mice ◽  
Serum Levels ◽  
Mrna Levels ◽  
Normal Range ◽  
Growth Defects ◽  
Low Levels

The thyroid gland is rich in selenium (Se) and expresses a variety of selenoproteins that are involved in antioxidative defense and metabolism of thyroid hormones (TH). Se deficiency impairs regular synthesis of selenoproteins and adequate TH metabolism. We recently generated mice that lack the plasma Se carrier, selenoprotein P (SePP). SePP-knockout mice display decreased serum Se levels and manifest growth defects and neurological abnormalities partly reminiscent of thyroid gland dysfunction or profound hypothyroidism. Thus, we probed the TH axis in developing and adult SePP-knockout mice. Surprisingly, expression of Se-dependent 5′-deiodinase type 1 was only slightly altered in liver, kidney, or thyroid at postnatal d 60, and 5′-deiodinase type 2 activity in brain was normal in SePP-knockout mice. Thyroid gland morphology, thyroid glutathione peroxidase activity, thyroid Se concentration, and serum levels of TSH, T4, or T3 were within normal range. Pituitary TSHβ transcripts and hepatic 5′-deiodinase type 1 mRNA levels were unchanged, indicating regular T3 bioactivity in thyrotropes and hepatocytes. Cerebellar granule cell migration as a sensitive indicator of local T3 action during development was undisturbed. Collectively, these findings demonstrate that low levels of serum Se or SePP in the absence of other challenges do not necessarily interfere with regular functioning of the TH axis. 5′-deiodinase isozymes are preferentially supplied, and Se-dependent enzymes in the thyroid are even less-dependent on serum levels of Se or SePP than in brain. This indicates a top priority of the thyroid gland and its selenoenzymes with respect to the hierarchical Se supply within the organism.

LINGUAL AND SUBLINGUAL THYROID GLANDS IN EUTHYROID CHILDREN

PEDIATRICS ◽  
1966 ◽  
Vol 38 (4) ◽  
pp. 647-651
Author(s):  
Wellington Hung ◽  
Judson G. Randolph ◽  
Domenic Sabatini ◽  
Theodore Winship
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Gland ◽  
Physical Examination ◽  
Thyroid Hormones ◽  
Hormone Therapy ◽  
Surgical Intervention ◽  
Ectopic Thyroid ◽  
Lingual Thyroid ◽  
Thyroid Glands ◽  
Careful Physical Examination

Five clinically euthyroid children with lingual or sublingual thyroid glands were seen during a 12-month period. Certain recommendations have been formulated based upon our experience with these patients. A careful physical examination should be performed to demonstrate the presence of a normally located thyroid gland in all children presenting with midline masses in the lingual or sublingual areas. When the thyroid gland cannot be palpated with certainty in these children, a scintiscan with I-131 should be carried out to determine if the mass is an ectopic thyroid gland and if a normally located thyroid gland is present. All children with lingual on sublingual thyroid glands should have a trial of full replacement thyroid hormone therapy before excision is contemplated. Thyroid therapy will prevent further hypertrophy and hyperplasia. Surgical intervention should be reserved for those children in whom there is dysphagia, dysphonia, ulceration, or hemorrhage due to a lingual thyroid gland or if the ectopic thyroid gland fails to decrease in size following a course of treatment with thyroid hormones.

The Thyroid

2011 ◽  
Author(s):  
Ildiko Lingvay ◽  
Shelby A. Holt
Keyword(s):  
Thyroid Gland ◽  
Thyroid Hormones ◽  
Thyroid Function ◽  
Classical Model ◽  
Critical Role ◽  
Thyroid Tissue ◽  
Endocrine Organ ◽  
Thyroglossal Duct ◽  
Parafollicular Cells ◽  
Developing Heart

The thyroid gland, which is the largest endocrine organ, secretes primarily thyroid hormones that play a critical role in the normal growth and development of the maturing human. In the adult, thyroid hormones maintain metabolic stability by regulating oxygen requirements, body weight, and intermediary metabolism. Thyroid function is under hypothalamic-pituitary control, and thus, like the gonads and adrenal cortex, it serves as a classical model of endocrine physiology. In addition, the physiological effects of thyroid hormones are regulated by complex extrathyroidal mechanisms resulting from the peripheral metabolism of the hormones, mechanisms that are not under hypothalamic-pituitary regulation. Thyroid function abnormalities are very prevalent, especially in females and in certain geographic areas, and are often a result of autoimmunity or iodine deficiency. The thyroid originates from two distinct parts of the embryonic endoderm: • The follicular structures arise from a midline thickening of the anterior pharyngeal floor (the base of the tongue), adjacent to the differentiating heart. This thyroid diverticulum first expands ventrally while still attached to the pharyngeal floor by its stalk (thyroglossal duct), and then expands laterally, leading to the characteristic bilobed structure. As the developing heart descends, the thyroid gets pulled into its final position, a process that leads to the rapid stretch and degeneration of the thyroglossal duct. • The parafollicular cells are derived from the ultimobranchial bodies (originating from the neural crest) but ultimately are surrounded by the medial thyroid. The parafollicular cells represents <10 % of the adult thyroid gland. The thyroid completes its structural development by 9 weeks of gestation, the first endocrine organ to assume its definitive form during organogenesis; yet full functional maturation and integration with the hypothalamic-pituitary axis continues throughout gestation. Abnormal thyroid development can lead to persistence of the thyroglossal duct, presence of ectopic thyroid tissue (lingual thyroid, lateral aberrant thyroid), and malposition (thoracic goiter), all of which can remain clinically silent or present later in life as diagnostic challenges. The shape of the human thyroid resembles that of a butterfly.

Thyroid hormone concentrations in the plasma of fed and fasted Brahman and Hereford steers

1994 ◽  
Vol 34 (4) ◽  
pp. 439
Author(s):  
JC O'Kelly ◽  
WG Spiers
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Hormones ◽  
Plasma Concentrations ◽  
Free T4 ◽  
Rumen Metabolism ◽  
Body Tissues ◽  
Breed Differences ◽  
Feeding Regimes ◽  
Ad Libitum ◽  
Brahman Steers

Plasma concentration patterns of thyroxine (TJ, free T4 (FT4), triiodothyronine (T3), and free T3 (FT3) were determined in Brahman steers fed lucerne hay ad libitum and in Brahman and Hereford steers fed restricted intakes of lucerne hay at the rate of either 208 g/h before fasting for 72 h or 250 g/h before fasting for 96 h. In Brahmans fed ad libitum, the plasma concentrations of all thyroid hormone fractions were significantly (P<0.01) correlated with one another and with feed intake. Within breeds, the concentrations of thyroid hormones were higher (P<0.001) when animals were fed at 250 g k than at 208 g/h. During both hourly feeding regimes T4, FT4, T3, and FT3 concentrations were higher (P<0.001) in Brahmans than in Herefords. Fasting after both hourly feeding regimes lowered (P<0.001) the concentrations of T4 about 53% in Brahmans and 30% in Herefords, while FT4, T3, and FT3 were lowered about 68% in Brahmans and 50% in Herefords. Consequently, thyroid hormone concentrations were significantly lower in Brahmans than in Herefords after 72 h fasting but did not differ significantly between breeds after 96 h fasting. The present results, together with those of our previous work showing breed differences in rumen metabolism, support the concept that, in Hereford and Brahman steers fed the same amount of hay in a thermoneutral environment, breed differences in plasma concentrations of thyroid hormones originate from quantitative differences in the supply of nutrients from the rumen to body tissues.

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