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(an′drō-stān″) A steroid hydrocarbon, C19H32, that is the precursor of androgenic hormones.


(an-drŏ-stēn″dī′ōn″, -stēn′dē-ōn″) A precursor of testosterone used orally by some athletes to enhance performance or increase body bulk. Androstenedione is banned by most sporting organizations.


(an-dros′tĕ-rōn″) [andro- + -sterone] C19H30O2; an androgenic steroid found in the urine. It is a metabolite of testosterone and androstenedione and has been synthesized.

-ane, -an

[L. -anus, adj. suffix] Suffixes in chemistry used in naming saturated hydrocarbons, e.g., butane.


(a′nek-dōt″) [L. anecdota, unpublished items fr Gr. anekdoton, unpublished] A brief report based on personal observation or random study and not on a systematic, scientific evaluation. anecdotal (a″nek-dōt′ăl), adj.


(a″nĕ-kō′ik) Sonolucent.


(an″ĕ-jak″yŭ-lā′shŏn) [1an- + ejaculation] The inability to release semen. Spinal cord injury is a frequent cause.


(ă-nē′mē-ă) [1an- + -emia] A reduction in the mass of circulating red blood cells. Patients are considered anemic when their hemoglobin levels are more than two standard deviations below the mean level in their hospital’s laboratory. The diagnosis of anemia is influenced by variables such as the patient’s age (neonates are anemic at levels of hemoglobin that would be considered polycythemic in some adults), gender (men have higher hemoglobin levels than women), pregnancy (hemodilution in pregnancy lowers measured hemoglobin), residential altitude, and ethnic or racial background. anemic (ă-nē′mik), adj. anemically (ă-nē′mik(ă-)lē), adv.

 Symptomatic anemia exists when hemoglobin content is less than meets the oxygen-carrying demands of the body. If anemia develops slowly, there may be no functional impairment even though the hemoglobin is less than 7 g/100/dL of blood.

 Anemia is not a disease but a symptom of other illnesses. It is classified on the basis of mean corpuscular volume as microcytic (80), normocytic (80–94), and macrocytic (>94); on the basis of mean corpuscular hemoglobin as hypochromic (27), normochromic (27–32), and hyperchromic (>32); and on the basis of etiological factors.

 ETIOLOGY: Anemia may be caused by bleeding, e.g., from the gastrointestinal tract or the uterus; vitamin or mineral deficiencies, esp. vitamin B12, folate, or iron; decreases in red blood cell production, e.g., bone marrow suppression in kidney failure or bone marrow failure in myelodysplastic syndromes; increases in red blood cell destruction as in hemolysis due to sickle cell anemia; or increases in red blood cell sequestration by the spleen (as in portal hypertension), or administration of toxic drugs (as in cancer chemotherapy).

 SYMPTOMS: Anemic patients may experience weakness, fatigue, ...

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