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Home >> Dictionary of Bioinformatics, Biochemistry, Biotechnology >> Hypoaldosteronism - Hypothyroidism
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Hypoaldosteronism
Isolated deficiency of aldosterone with normal production of cortisol. This occurs due to hyporeninism, following surgical removal of aldosterone secreting adenomas, inherited defect in aldosterone biosynthesis, prolonged heparin administration and severe postural hypotension. Hyperkalaemia exacerbated by salt restriction is a characteristic finding. Treatment involves replacement therapy with mineralocorticoids.
Hypocalcaemia
Low calcium level in the blood.
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Hypocholesterolaemia
Abnormally low levels of cholesterol in the blood.
Hypochromic
A decrease in the concentration of haemoglobin in the erythrocytes.
Hypochromic effect
Refers to a decrease in intensity of the absorption maximum. It results from introduction of groups, which cause distortion in the geometry of the absorbing molecules.
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Hypogammaglobulinaemia
A decrease in plasma gamma globulin levels. This may be transient primary, or secondary.
Hypoglycaemia
Plasma glucose level less than 2.5 mmol/L (45 mg/dL). Maintenance of normal blood glucose is important because glucose is the primary source of energy for the brain. Prolonged hypoglycaemia can lead to coma, cerebral damage and death. The clinical manifestations of hypoglycaemia include adrenergic symptoms such as sweating, tremor, anxiety, tachycardia and hunger. The central nervous system (CNS) symptoms are dizziness, reduced mental acuity, visual abnormalities, convulsions and loss of consciousness. There are two main categories of hypoglycaemia: postprandial or reactive hypoglycaemia, in which symptoms occur within 5-6 hours after a meal, precipitated by ingestion of certain types of food or drugs, and fasting hypoglycaemia, in which symptoms occur in the night or in the early morning, precipitated by fasting or strenuous exercise.
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Hypogonadism
Defective spermatogenesis and/or testosterone production. It may be primary or secondary to pituitary or hypothalamic disease. Primary hypogonadism is due to testicular disease whereas secondary hypogonadism occurs due to pituitary or hypothalamic disorders.
Hypogonadotrophic hypogonadism
A disorder caused by pituitary or hypothalamic disease with decreased plasma levels of the trophic hormones.
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Hypoparathyroidism
A deficiency of parathyroid hormone, characterised by hypocalcaemia.
Hypophosphataemia Low blood phosphate level.
Hypopituitarism
A deficiency of hormone secretion by the pituitary. It may involve one or more hormones and may be congenital or acquired. The anterior pituitary has considerable functional reserve.
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Failure of all anterior pituitary functions or panhypopituitarism is therefore, less common. Hypopituitarism can result from isolated hormone deficiencies, tumours of the pituitary or hypothalamus, surgery or radiation of the pituitary, postpartum infarction, inflammatory diseases, anorexia nervosa, stress or severe illness. The clinical features include growth retardation as well as gonadotrophin and prolactin deficiency. Investigation of hypopituitarism should confirm gland deficiency before monitoring pituitary hormone secretion.
Hypochlorite
Decreased amount of hydrochloric acid in the gastric juice.
Hypochlorite
A generic term used for aqueous solutions of sodium hypochlorite, potassium hypochlorite or calcium hypochlorite, which are oxidising agents. These agents are used for disinfecting surfaces and surface-sterilising tissues, and for bleaching.
Hypochloraemia
Low blood chlorides.
Hypolipoproteinaemia
Low levels of lipoproteins in the blood.
Hypomorph
A mutation that decreases but does not completely abolish gene expression.
Hyponatraemia
Low sodium concentration in the blood.
Hypoploid
A genetic condition in which a chromosome or segment of a chromosome is underrepresented in the genotype.
Hypostatic; hypostasis
See epistasis.
Hypotension
Decrease in blood pressure.
Hypothalamic peptides
Peptides that are generated in the vertebrate forebrain and which play a role in the regulation of various physiological processes in the body.
Hypothalamus
An area at the base of the brain that stimulates the pituitary gland and regulates bodily functions, such as body temperature, hunger, and thirst.
Hypothermia
Low body temperature.
Hypothesis
(Gr. hypothesis, foundation) A tentative theory or supposition that is provisionally adopted in order to explain some facts and to guide in the investigation of other facts. Once a hypothesis is proven by rigorous scientific investigation, it becomes a theory or a law.
Hypothyroidism
Decreased function of the thyroid gland. hypothyroidism may be either primary, as a result of thyroid disease, or secondary to pituitary or hypothalamic disease. Primary hypothyroidism may be due to atrophic autoimmune thyroiditis and Hashimoto’s disease, ablation of the thyroid gland following treatment of hyperthyroidism, iodine deficiency, and drugs such as propylthiouracil. Secondary hypothyroidism is less common than primary hypothyroidism and is due to anterior pituitary or hypothalamic disease.
The plasma TSH levels are inappropriately low. The general clinical symptoms of hypothyroidism include decreased BMR with decreased body temperature, cold intolerance, weight gain, decreased appetite, constipation, fatigue, somnolence, decreased muscle tone, Bradycardia, scaliness of skin, hoarse voice, and metabolic abnormalities such as hypercholesterolaemia and decreased glucose utilisation. Plasma T4 is decreased in all types of hypothyroidism. In primary hypothyroidism, TSH is increased due to decreased negative feedback, whereas in secondary hypothyroidism, TSH is decreased. TRH test is useful in diagnosing early primary hypothyroidism as well as in the differential diagnosis of secondary hypothyroidism. Levothyroxine is the preferred treatment for hypothyroidism.
Hypotonia
Decreased tone of skeletal muscles.
Hypotonic
Osmotic potential that is less than that of living cells. Cells that are kept in a hypotonic solution show swelling and turgidity.
Hypovolaemia
Low plasma volume.
Hypoxaemia
Insufficient oxygenation of blood.
Hypoxanthine
A purine intermediate in the catabolic pathway. It is also a precursor for nucleic acid synthesis by the salvage pathway.
Hypoxanthine guanine phosphoribosyl transferase
See HGPRT.
Hypoxia
Diminished oxygen supply to a tissue.
Hypsochromic shift
A shift of the absorption maximum towards shorter wavelength also known as the blue shift. It may be caused by removal of conjugation and a change in the polarity of the solvent.
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