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Jod-Basedow Phenomenon
The Jod-Basedow effect (also Jod-Basedow syndrome and Jod-Basedow phenomenon) is hyperthyroidism following administration of iodine or iodide, either as a dietary supplement, for iodinated contrast medical imaging, or as a medication (mainly amiodarone). Pathophysiology This phenomenon is thus iodine-induced hyperthyroidism, typically presenting in a patient with endemic goiter (due to iodine deficiency), who relocates to an iodine-abundant geographical area. People who have Graves disease, toxic multinodular goiter, or various types of thyroid adenoma are also at risk of the Jod-Basedow effect when receiving iodine, because the thyroid will then not respond to the negative feedback from increased thyroid hormones. The source of iodine may be from the diet, administration of iodinated contrast for medical imaging, or amiodarone (an antiarrhythmic drug). The hyperthyroidism usually develops over 2 to 12 weeks following iodine administration. In some ways the Jod-Basedow phenomen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperthyroidism
Hyperthyroidism is a endocrine disease in which the thyroid gland produces excessive amounts of thyroid hormones. Thyrotoxicosis is a condition that occurs due to elevated levels of thyroid hormones of any cause and therefore includes hyperthyroidism. Some, however, use the terms interchangeably. Signs and symptoms vary between people and may include irritability, muscle weakness, sleeping problems, a tachycardia, fast heartbeat, heat intolerance, diarrhea, goitre, enlargement of the thyroid, hand tremor, and weight loss. Symptoms are typically less severe in the elderly and during pregnancy. An uncommon but life-threatening complication is thyroid storm in which an event such as an infection results in worsening symptoms such as confusion and a hyperthermia, high temperature; this often results in death. The opposite is hypothyroidism, when the thyroid gland does not make enough thyroid hormone. Graves' disease is the cause of about 50% to 80% of the cases of hyperthyroidism ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thyroid Hormone
File:Thyroid_system.svg, upright=1.5, The thyroid system of the thyroid hormones triiodothyronine, T3 and T4 rect 376 268 820 433 Thyroid-stimulating hormone rect 411 200 849 266 Thyrotropin-releasing hormone rect 297 168 502 200 Hypothalamus rect 66 216 386 256 Anterior pituitary, Anterior pituitary gland rect 66 332 342 374 Negative feedback rect 308 436 510 475 Thyroid, Thyroid gland rect 256 539 563 635 Thyroid hormones rect 357 827 569 856 Catecholamine rect 399 716 591 750 Metabolism desc bottom-left Thyroid hormones are two hormones produced and released by the thyroid gland, triiodothyronine (T3) and thyroxine (T4). They are tyrosine-based hormones that are primarily responsible for regulation of metabolism. T3 and T4 are partially composed of iodine, derived from food. A deficiency of iodine leads to decreased production of T3 and T4, enlarges the thyroid, thyroid tissue and will cause the disease known as simple goitre. The major form of thyroid hormone in the blood ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karl Adolph Von Basedow
Carl Adolph von Basedow (28 March 1799 – 11 April 1854) was a German physician most famous for reporting the symptoms of what could later be dubbed Graves-Basedow disease, now technically known as exophthalmic goiter. Biography Basedow was born in Dessau. He graduated from Halle University. He subsequently began general practice in Merseburg in 1822. He married early and became the town's chief medical officer, a position he would hold for the rest of his life. In 1840, Basedow reported on the conditions of what is now called Graves-Basedow disease. He died in Merseburg in 1854 after contracting spotted fever from a corpse he was dissecting. Medical work Basedow has three eponymous medical conditions: Basedow's coma, a thyreotoxic coma; Basedow's ocular syndromes, the unilateral retraction of the upper lid in Basedow’s syndrome; and, Graves-Basedow disease, a disorder characterized by the "Merseburger triad": tachycardia, goitre, and exophthalmos Exophthalmos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hashimoto's Thyroiditis
Hashimoto's thyroiditis, also known as chronic lymphocytic thyroiditis, Hashimoto's disease and autoimmune thyroiditis, is an autoimmune disease in which the thyroid gland is gradually destroyed. Early on, symptoms may not be noticed. Over time, the thyroid may enlarge, forming a painless goiter. Most people eventually develop hypothyroidism with accompanying weight gain, fatigue, constipation, hair loss, and general pains. After many years the thyroid typically shrinks in size. Potential complications include thyroid lymphoma. Further complications of hypothyroidism can include high cholesterol, heart disease, heart failure, high blood pressure, myxedema, and potential problems in pregnancy. Hashimoto's thyroiditis is thought to be due to a combination of genetic and environmental factors. Risk factors include a family history of the condition and having another autoimmune disease. Diagnosis is confirmed with blood tests for TSH, thyroxine ( T4), antithyroid autoant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graves' Disease
Graves' disease, also known as toxic diffuse goiter or Basedow's disease, is an autoimmune disease that affects the thyroid. It frequently results in and is the most common cause of hyperthyroidism. It also often results in an enlarged thyroid. Signs and symptoms of hyperthyroidism may include irritability, muscle weakness, sleeping problems, a fast heartbeat, poor tolerance of heat, diarrhea and unintentional weight loss. Other symptoms may include thickening of the skin on the shins, known as pretibial myxedema, and eye bulging, a condition caused by Graves' ophthalmopathy. About 25 to 30% of people with the condition develop eye problems. The exact cause of the disease is unclear, but symptoms are a result of antibodies binding to receptors on the thyroid causing over-expression of thyroid hormone. Persons are more likely to be affected if they have a family member with the disease. If one monozygotic twin is affected, a 30% chance exists that the other twin will ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thyroid Disease
Thyroid disease is a medical condition that affects the structure and/or function of the thyroid gland. The thyroid gland is located at the front of the neck and produces thyroid hormones that travel through the blood to help regulate many other organs, meaning that it is an endocrine organ. These hormones normally act in the body to regulate energy use, infant development, and childhood development. There are five general types of thyroid disease, each with their own symptoms. A person may have one or several different types at the same time. The five groups are: # Hypothyroidism (low function) caused by not having enough free thyroid hormones # Hyperthyroidism (high function) caused by having too many free thyroid hormones # Structural abnormalities, most commonly a goiter (enlargement of the thyroid gland) # Tumors which can be benign (not cancerous) or cancerous # Abnormal thyroid function tests without any clinical symptoms (subclinical hypothyroidism or subclinical hyper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wolff–Chaikoff Effect
The Wolff–Chaikoff effect is a presumed reduction in thyroid hormone levels caused by ingestion of a large amount of iodine. It was discovered by Drs. Jan Wolff and Israel Lyon Chaikoff at the University of California, Berkeley: in 1948, they reported that injection of iodine in rats almost completely inhibited organification (thyroglobulin iodination) in the thyroid gland. However, recent research into the study shows that the thyroid hormone levels of the rats were not checked prior to injections. Patients with Graves' disease are more sensitive than euthyroid patients, and iodine has been used to manage Graves' disease. The Wolff–Chaikoff effect is known as an autoregulatory phenomenon that inhibits organification in the thyroid gland, the formation of thyroid hormones inside the thyroid follicle, and the release of thyroid hormones into the bloodstream. This becomes evident secondary to elevated levels of circulating iodide. The Wolff–Chaikoff effect is an effectiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plummer Effect
The Plummer effect is one of several physiological Feed forward (control), feedforward mechanisms taking place in Thyroid follicular cell, follicular cells of the healthy thyroid gland and preventing the development of thyrotoxicosis in situations of extremely high supply with iodine. History In 1923 the American physician Henry Stanley Plummer discovered that high-dose iodine may be effective in the treatment of Graves' disease, Graves’ disease. Today, “Plummering”, i.e. therapy with Lugol's iodine solution, is one of several emergency measures in the management of severe thyrotoxicosis. Mechanism Via the Plummer effect, a high iodine concentration inhibits the proteolysis of thyroglobulin and the release of pre-formed thyroid hormones from thyroid follicles. Therefore, its mechanism differs from that of the Wolff–Chaikoff effect, where iodine inhibits the uptake of iodine in thyroid cells and the formation of thyroid hormones, and of the dehalogenase inhibition effec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antiarrhythmic
Antiarrhythmic agents, also known as cardiac dysrhythmia medications, are a class of drugs that are used to suppress abnormally fast rhythms (tachycardias), such as atrial fibrillation, supraventricular tachycardia and ventricular tachycardia. Many attempts have been made to classify antiarrhythmic agents. Many of the antiarrhythmic agents have multiple modes of action, which makes any classification imprecise. Action potential The cardiac myocyte has two general types of action potentials: conduction system and working myocardium. The action potential is divided into 5 phases and shown in the diagram. The sharp rise in voltage ("0") corresponds to the influx of sodium ions, whereas the two decays ("1" and "3", respectively) correspond to the sodium-channel inactivation and the repolarizing efflux of potassium ions. The characteristic plateau ("2") results from the opening of voltage-sensitive calcium channels. Each phase utilizes different channels and it is useful to compar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thyroid Adenoma
A thyroid adenoma is a benign tumor of the thyroid gland, that may be inactive or active (functioning autonomously) as a toxic adenoma. Signs and symptoms A thyroid adenoma may be clinically silent ("cold" adenoma), or it may be a functional tumor, producing excessive thyroid hormone ("warm" or "hot" adenoma). In this case, it may result in symptomatic hyperthyroidism, and may be referred to as a toxic thyroid adenoma. Diagnosis Morphology Thyroid follicular adenoma ranges in diameter from 3 cm on an average, but sometimes is larger (up to 10 cm) or smaller. The typical thyroid adenoma is solitary, spherical and encapsulated lesion that is well demarcated from the surrounding parenchyma. The color ranges from gray-white to red-brown, depending upon # the cellularity of the adenoma # the colloid content. Areas of hemorrhage, fibrosis, calcification, and cystic change, similar to what is found in multinodular goiters, are common in thyroid (follicular) adenoma, particular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iodine
Iodine is a chemical element; it has symbol I and atomic number 53. The heaviest of the stable halogens, it exists at standard conditions as a semi-lustrous, non-metallic solid that melts to form a deep violet liquid at , and boils to a violet gas at . The element was discovered by the French chemist Bernard Courtois in 1811 and was named two years later by Joseph Louis Gay-Lussac, after the Ancient Greek , meaning 'violet'. Iodine occurs in many oxidation states, including iodide (I−), iodate (), and the various periodate anions. As the heaviest essential mineral nutrient, iodine is required for the synthesis of thyroid hormones. Iodine deficiency affects about two billion people and is the leading preventable cause of intellectual disabilities. The dominant producers of iodine today are Chile and Japan. Due to its high atomic number and ease of attachment to organic compounds, it has also found favour as a non-toxic radiocontrast material. Because of the spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toxic Multinodular Goiter
Toxic multinodular goiter (TMNG), also known as multinodular toxic goiter (MNTG), is an active multinodular goiter associated with hyperthyroidism. It is a common cause of hyperthyroidism in which there is excess production of thyroid hormones from functionally autonomous thyroid nodules, which do not require stimulation from thyroid stimulating hormone (TSH). Toxic multinodular goiter is the second most common cause of hyperthyroidism (after Graves' disease) in the developed world, whereas iodine deficiency is the most common cause of hypothyroidism in developing-world countries where the population is iodine-deficient. (Decreased iodine leads to decreased thyroid hormone.) However, iodine deficiency can cause goiter (thyroid enlargement); within a goitre, nodules can develop. Risk factors for toxic multinodular goiter include individuals over 60 years of age and being female. Signs and symptoms Symptoms of toxic multinodular goitre are similar to that of hyperthyroidism, inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
