Amyloidosis is a progressive, incurable, metabolic disease characterized by abnormal deposits of protein in one or more organs or body systems.
Amyloid proteins are manufactured by malfunctioning bone marrow. Amyloidosis, which occurs when accumulated amyloid deposits impair normal body function, can cause organ failure or death
. It is a rare disease, occurring in about eight of every 1,000,000 people. It affects males and females equally and usually develops after the age of 40. At least 15 types of amyloidosis have been identified. Each one is associated with deposits of a different kind of protein.
Types of amyloidosis
The major forms of this disease are primary systemic, secondary, and familial or hereditary amyloidosis. There is also another form of amyloidosis associated with Alzheimer's disease.
Primary systemic amyloidosis usually develops between the ages of 50 and 60. With about 2,000 new cases diagnosed annually, primary systemic amyloidosis is the most common form of this disease in the United States. Also known as light-chain-related amyloidosis, it may also occur in association with multiple myeloma
(bone marrow cancer
Secondary amyloidosis is a result of chronic infection or inflammatory disease. It is often associated with:
- familial Mediterranean fever (a bacterial infection characterized by chills, weakness, headache, and recurring fever)
- granulomatous ileitis (inflammation of the small intestine)
- Hodgkin's disease (cancer of the lymphatic system)
- osteomyelitits (bacterial infection of bone and bone marrow)
- rheumatoid arthritis
Familial or hereditary amyloidosis is the only inherited form of the disease. It occurs in members of most ethnic groups, and each family has a distinctive pattern of symptoms and organ involvement. Hereditary amyloidosis is though to be autosomal dominant, which means that only one copy of the defective gene is necessary to cause the disease. A child of a parent with familial amyloidosis has a 50-50 chance of developing the disease.
Amyloidosis can involve any organ or system in the body. The heart, kidneys, gastrointestinal system, and nervous system are affected most often. Other common sites of amyloid accumulation include the brain, joints, liver, spleen, pancreas, respiratory system, and skin.
Causes and symptoms
The cause of amyloidosis is unknown. Most patients have gastrointestinal abnormalities, but other symptoms vary according to the organ(s) or system(s) affected by the disease. Usually the affected organs are rubbery, firm, and enlarged.
Because amyloid protein deposits can limit the heart's ability to fill with blood between beats, even the slightest exertion can cause shortness of breath
. If the heart's electrical system is affected, the heart's rhythm may become erratic. The heart may also be enlarged and heart murmurs
may be present. Congestive heart failure may result.
The feet, ankles, and calves swell when amyloidosis damages the kidneys. The kidneys become small and hard, and kidney failure may result. It is not unusual for a patient to lose 20-25 pounds and develop a distaste for meat, eggs, and other protein-rich foods. Cholesterol elevations that don't respond to medication and protein in the urine (proteinuria) are common.
Nervous system symptoms often appear in patients with familial amyloidosis. Inflammation and degeneration of the peripheral nerves (peripheral neuropathy) may be present. One of four patients with amyloidosis has carpal tunnel syndrome, a painful disorder that causes numbness or tingling in response to pressure on nerves around the wrist. Amyloidosis that affects nerves to the feet can cause burning or numbness in the toes and soles and eventually weaken the legs. If nerves controlling bowel function are involved, bouts of diarrhea
alternate with periods of constipation. If the disease affects nerves that regulate blood pressure, patients may feel dizzy or faint when they stand up suddenly.
Liver and spleen
The most common symptoms are enlargement of these organs. Liver function is not usually affected until quite late in the course of the disease. Protein accumulation in the spleen can increase the risk of rupture of this organ due to trauma.
The tongue may be inflammed, enlarged, and stiff. Intestinal movement (motility) may be reduced. Absorption of food and other nutrients may be impaired (and may lead to malnutrition
), and there may also be bleeding, abdominal pain
, constipation, and diarrhea.
Skin symptoms occur in about half of all cases of primary and secondary amyloidosis and in all cases where there is inflammation or degeneration of the peripheral nerves. Waxy-looking raised bumps (papules) may appear on the face and neck, in the groin, armpits, or anal area, and on the tongue or in the ear canals. Swelling, hemorrhage beneath the skin (purpura), hair loss, and dry mouth may also occur.
Airways may be obstructed by amyloid deposits in the nasal sinus, larynx and traches (windpipe).
Blood and urine tests can reveal the presence of amyloid protein, but tissue or bone-marrow biopsy is necessary to positively diagnose amyloidosis. Once the diagnosis has been confirmed, additional laboratory tests and imaging procedures are performed to determine:
- which type of amyloid protein is involved
- which organ(s) or system(s) have been affected
- how far the disease has progressed
— A waxy, starch-like protein.
— Parent cells from which other cells are made.
The goal of treatment is to slow down or stop production of amyloid protein, eliminate existing amyloid deposits, alleviate underlying disorders (that give rise to secondary amyloidosis), and relieve symptoms caused by heart or kidney damage. Specialists in cardiology, hematology (the study of blood and the tissues that form it), nephrology (the study of kidney function and abnormalities), neurology (the study of the nervous system), and rheumatology (the study of disorders characterized by inflammation or degeneration of connective tissue) work together to assess a patient's medical status and evaluate the effects of amyloidosis on every part of the body.
Colchicine (Colebenemid, Probeneaid), prednisone, (Prodium), and other anti-inflammatory drugs can slow or stop disease progression. Bone-marrow and stem-cell transplants can enable patients to tolerate higher and more effective doses of melphalan (Alkeran) and other chemotherapy
drugs prescribed to combat this non-malignant disease. Surgery can relieve nerve pressure and may be performed to correct other symptom-producing conditions. Localized amyloid deposits can also be removed surgically. Dialysis or kidney transplantation
can lengthen and improve the quality of life for patients whose amyloidosis results in kidney failure. Heart transplants are rarely performed.
Although no link has been established between diet and development of amyloid proteins, a patient whose heart or kidneys have been affected by the disease may be advised to use a diuretic or follow a low-salt diet.
Most cases of amyloidosis are diagnosed after the disease has reached an advanced stage. The course of each patient's illness is unique but death, usually a result of heart disease or kidney failure, generally occurs within a few years. Amyloidosis associated by multiple myeloma usually has a poor prognosis. Most patients with both diseases die within one to two years.
Genetic couseling may be helpful for patients with hereditary amyloidosis and their families. Use of Cholchicine in patients with familial Mediterranean fever has successfully prevented amyloidosis.
Amyloidosis Network International. 7118 Cole Creek Drive, Houston, TX 77092-1421. (888) 1AMYLOID. 〈http://www.health.gov/nhic/Scripts/Entry.cfm?HRCode=HR2397〉.
National Organization for Rare Disorders. P.O. Box 8923, New Fairfield, CT 06812-8923. (800) 999-6673. http://www.rarediseases.org.
amyloidosis Systemic amyloidosis Internal medicine A group of diseases in which amyloid protein is deposited in specific organs–localized amyloidosis or throughout the body–systemic amyloidosis deposition of amyloid, which can be 1º, which usually affects nerves, skin, tongue, joints, heart, or liver, or 2º to other conditions–eg, TB, CA, leprosy, and accompanied by immune system changes, which affect the spleen, kidneys, liver, and adrenal glands. See Cardiac amyloidosis, Cerebral amyloidosis, Hereditary amyloidosis.
- AL amyloidosis
- 1º amyloidosisAn uncommon condition associated with plasma cell dyscrasias, where the accumulated amyloid fibers correspond to fragments of Ig light chains; the median survival in one study of 153 Pts with primary AL amyloidosis as 20 months, less if they had signs of renal or cardiac amyloidosis and up to 40 months if neither system was involved
- AA amyloidosis
- Reactive amyloidosis, 2º amyloidosisA group of conditions seen in chronic inflammation, in which the accumulated fibers derive from a circulating acute-phase lipoprotein, known as serum protein A.
Both types of amyloidosis contain amyloid P component, a non-fibrillary glycoprotein found in the circulation; scintigraphy after injection of123I-labelled serum amyloid P component can locate tissue deposition of amyloidosis and if the deposition is active, cytotoxic therapy may be instituted; focal amyloidosis commonly occurs in those organs most susceptible to aging, eg the heart and brain, and only is symptomatic if the amyloid deposition is significant
amyotrophic lateral sclerosis
Lou Gehrig's disease Neurology A chronic, progressive degenerative, motor neuron disease, characterized by upper limb weakness, atrophy and focal neurologic signs Epidemiology Incidence, 0.5-1.5/105, more common in ♂, usually > age 50; occurs randomly thoughout the world with local clustering on the Kii Peninsula, Japan and Guam, where it is associated with dementia, parkinsonism, Alzheimer's Clinical Loss of fine motor skills, triad of atrophic weakness of hands and forearms; leg spasticity; generalized hyperreflexia Management Possible riluzole. See Motor neuron disease
Neurology Muscle wasting. See Hereditary neuralgic amyotrophy
Amytal® Amobarbital, see there.
ANA Antinuclear antibodies, see there, also. 1. American Neurological Association 2 Antiviral nucleoside analogue, see there.
ANA-negative systemic lupus erythematosus
SLE characterized by absence of antinuclear antibodies–seen in 5% of SLE, photosensitivity, features of Sjögren syndrome, a low incidence of lupus nephritis and lupus psychosis, presence of rheumatoid factor and antibodies to Ro/SSA antigen and La/SSB antigens and single-stranded DNA. See Antinuclear antibodies, Lupus erythematosus
. Cf Antiphospholipid syndrome.
anabolic Medtalk adjective Relating to anabolism–stimulating synthesis or building up, in particular of tissue, especially muscle
Anabolic-androgenic steroid Endocrinology A drug or hormone-like substance, chemically or pharmacologically related to 17-α-alkylated testosterone that promotes muscle growth, which is commonly abused by athletes Lipid changes by ASs ↓ HDL-C–especially HDL2
↑ hepatic TG lipase–HDL catabolism Indications Children, adolescents with delayed puberty, ↓ growth, small penis, hypogonadism, testosterone deficiency, osteoporosis management, aplastic anemia, endometriosis, angioedema, sports performance enhancement—no longer legal, relief and recovery from common injuries, rehabilitation, weight control, anti-insomnia, regulation of sexuality, aggression, cognition Route Oral, parenteral Metabolic effects ↑ Protein sythesis and amino acid consumption, androgenesis, catabolism Adverse effects–♂ Breast enlargement, testicular atrophy, sterility, sperm abnormalities, impotence, and prostatic hypertrophy; ♀ Clitoral hypertrophy, beard growth, baldness, deepened voice, decreased breast size; ♀/♂ Aggression and antisocial behavior, 'roid rage'; ↑ risk of cardiovascular disease, peliosis hepatis, hemorrhage, jaundice, acne, accelerated bone maturation, resulting in short stature, liver tumors–hepatic adenomas and CA, which may regress with abstinence Lab ASs are detectable to 1 ppb 4 days after last use if the hormone is water-soluble, or 14 days after use in lipid-soluble compounds FDA status ASs are 'schedule III' drugs per the Controlled Substances Act; AS abusers are ↑ risk for HIV transmission, given the common practice of injecting ASs and 'fraternal' sharing of needles. See 'Roid rage
anabolism Synthesis; a phase of metabolism involving chemical reactions within cells that result in the production of larger molecules from smaller ones. Cf Catabolism.
anaclitic depression Neonatology A response in infants who have been separated from their mothers for prolonged periods of time, resulting in a disruption of the mother-child dyad. See Genie, Holtism, Social isolation; Cf Bonding, Companionship, Infant massage.
anaerobe Microbiology Any organism, usually a bacterium, capable of living without air; anaerobic pathogens obtain their energy from fermentation; nonpathogenic anerobes in nature obtain their energy from anaerobic respiration in which nitrate or sulfate serves as electron acceptors; oropharynx, skin, colon, vagina harbor up to 1011 anaerobes/cm3; anaerobes are common causes of infection, and may be associated with aerobic flora in infections and abscesses of the oral cavity, upper respiratory tract, colon, genital tract, skin, and brain; factors controlling anaerobes' virulence are uncertain Treatment Penicillin for supradiaphragmatic anaerobic infections; clindamycin, metronidazole, chloramphenicol, or cephoxatin, if the infection is below the diaphragm. See Aerotolerant anaerobe, Facultative anaerobe, Microaerophile, Obligate aerobe, Obligate anaerobe.
anaerobic adjective 1. Referring to an anaerobe 2. Lacking O2
anaerobic exercise Sports medicine A general term for exercise consisting of slow rhythmic movements against a force–eg, calisthenics–push-ups, sit-ups, weight lifting, which evoke a minimal ↑ in heart rate; AE strengthens muscles, ↑ joint mobility, and ↓ risk of musculoskeletal injury. Cf Aerobic exercise.
Anafranil Clomipramine, see there.
anagrelide Hematology An agent used to manage essential thrombocythemia and thrombocythemia due to myeloproliferative disorders–eg, CML, polycythemia vera—to ↓ platelets, risk of thrombosis and other Sx
anal adjective Pertaining to the anus
anal agenesis A condition caused by a defective development of the anus; the anal dimple is present; perianal stimulation of a neonate results in puckering, which indicates the presence of the external sphincter Clinical Complete intestinal obstruction in absence of a perineal fistula. See Anorectal anomalies.
anal atresia Imperforate anus, see there.
anal canal The terminal tubular part of the large intestine that opens via the anus
Oncology A malignancy of the anal canal, which has been linked to anal intercourse Pathology Adenocarcinoma is more common in the proximal anus; the transition zone is associated with various malignancies–eg, carcinoma, lymphoma, melanoma; squamous cell carcinoma is most common in the distal anus, and may be accompanied by HPV infection. See Anal intraepithelial neoplasia.
Anal cancer staging
- spread beyond anal mucosa; < 2 cm
- CA spread beyond anal mucosa; > 2 cm
- CA spread to perirectal lymph nodes or to adjacent organs–eg, vagina, bladder
- CA spread to abdominal or inguinal lymph nodes or to both nearby organs and perirectal lymph nodes
- CA spread to distant lymph nodes within the abdomen or metastasized
Psychiatry A personality type that manifests excessive orderliness, miserliness, and obstinacy; in psychoanalysis, a pattern of behavior in an adult that may originate in the anal phase of infancy, between age 1 and 3. See Psychosexual development
anal fissure Surgery A common condition, consisting of a tear or superficial laceration in the anal mucosa, extending from the anal verge toward the dentate line; 90% of 1º AFs are posterior Clinical Pain, spasms, bright red blood in stool Management Surgery–which permanently weakens the internal sphincter; conservative-chemical denervation with botulinum toxin by injection; topical application of nitroglycerin See Botulinum toxin.
Insertion of an erect penis per anus in a fashion analogous to that of vaginal intercourse. See Anal epithelial lesion, Anal intraepithelial neoplasia, Gay bowel syndrome
anal intraepithelial neoplasia
Oncology A carcinoma in situ of the anorectal mucosa, which most commonly affects immunosuppressed ♂ homosexuals who are often infected by various HPV types; AIN is histologically characterized by irregular nuclear shape and chromatin and hyperchromasia. See CIN
, Intraepithelial neoplasia
. Cf Anal epithelial lesion.
anal personality See Anal-retentive.
anal-retentive Psychology adjective Referring to a person with an 'anal personality' who, according to classic Freudian psychoanalysis, has traits that arose in the anal phase of psychosexual development, in which defecation constituted the 1º source of pleasure, and retention of feces is viewed as a manifestation of defiance to a parent figure noun A popular term for an anal-retentive person, who is obstinate, rigid, meticulous, compulsive, and overly conscientious, a behavioral profile typical of many physicians and scientists
anal stage Psychiatry The period of pregenital psychosexual development, usually from age 1 to 3, in which the child has particular interest and concern with the process of defecation and the sensations connected with the anus; the pleasurable part of the experience is termed anal eroticism. See Anal character.
anal tag Surgery Swollen skin at the peripheral end of an anal fissure, often accompanied by pain on defecation and fresh bleeding. See Anal fissure.
Neurology A state of insensitivity to pain, which is the result of 1. Pharmacotherapy with an analgesic. See Oligoanalgesia
, Patient-controlled analgesia
, Preemptive analgesia 2. Derangement of sensation
Referring to ↓ pain noun
Pain management Painkiller An agent that ↓ perception of pain–nociceptive stimulation without causing loss of consciousness or anesthesia. See Adjuvant analgesic
analgesic drug 'ladder'
Clinical pharmacology An algorithm for managing cancer pain, according to the levels of intensity of therapy, delineated by the WHO
Analgesic Ladder–per WHO
- 1st step
- Non-opioids with/without adjuvants–neurolytic blockage, cordotomy, chemical hypophysectomy and others, using choline magnesium trisalisylate, salsalate
- 2nd step
- Weak opioids, with/without non-opioids and/or adjuvants, eg codeine, hydrocodone, often produced in combination with aspirin or acetaminophen
- 3rd step
- Strong opioids, with/without non-opioids and/or adjuvants, eg morphine sul fate, available in various forms, eg tablets, elixir, suppository
Analgesic-associated nephropathy, phenacetin nephritis A form of kidney damage caused by overexposure to certain analgesics, including phenacetin, acetaminophen, aspirin, and NSAIDs Clinical Hematuria, renal colic, pyelonephritis Imaging Intravenous pyelogram reveals 'ring' shadows and multiple characteristic cavitations Complications ↑ Risk of transitional cell carcinoma, acute renal failure. See Interstitial nephritis
Pain management An ↑ need for opioids to achieve the same level of analgesia. Cf Addiction
analingus Sexology Stimulation of the anus with tongue and lips; not a paraphilia; it is either part of normophilic sexuoerotic activity or part of the sadomasochistic repertory. See Anal intercourse.
Referring to data in the form of continuously variable–non-discrete physical quantities, the mode in which most laboratory instruments produce information, where data is generated as non-discrete signals, as AC or DC current, voltage changes or pulse amplitudes. Cf Analogue, Digital
Pharmacology A therapeutic agent with structural or chemical similarity to another substance, or which mimics the effects of another agent, but has a different chemical structure. See Antinucleoside analogue
, Base analogue, Nicotine analogue
, Nucleoside analogue
, Purine analogue
, Cf Analog.
Lab medicine The quantification or other form of assessment of the constituents or elements of a substance of interest. See Activation analysis, Amniotic fluid analysis
, ANCOVA, ANOVA
, Aura analysis, Base sequence analysis, Bayesian analysis
, Best interests analysis, Blood gas analysis
, BRAC analysis, Breakeven analysis, Canonical correlation analysis, Capillary ion analysis, Character analysis, Chimerism analysis, Chinese hand analysis, Chromosome analysis
, Clinical decision analysis
, Clonal analysis, Clot waveform analysis, Combustion analysis, Coordination analysis, Cost-benefit analysis
, Cost-effectiveness analysis
, Cost of failure analysis, Cost of illness analysis, Cost minimization analysis, DF extremes analysis, Decision analysis
, Deletion analysis, Discriminant analysis, Distributive and synthesis analysis, DNA analysis
, DNA ploidy analysis
, DNA sequence analysis, Dual parameter analysis, Energy-dispersive-x-ray analysis, Error rate-bound analysis, Expression analysis, Factor analysis, Foot analysis, Gap analysis, Gastric analysis
, Gel shift analysis, Genetic linkage analysis, Hair analysis
, Head space analysis, Heteroduplex analysis, High-resolution chromosome analysis, Image analysis, Information for Management analysis, Intent to treat analysis, Interim analysis
, Kaplan-Meier analysis, Karyotype analysis, Laban movement analysis, Linkage analysis
, Live cell analysis, Markovian analysis
, Markovian texture analysis, Meta-analysis
, Microanalysis, Microarray analysis, Microsatellite analysis, Model-fitting analysis, Molecular genetic analysis
, Monte Carlo analysis, Movement analysis, Multivariate/logistic-regression analysis, Network analysis, Neutron activation analysis, Orthogonal regression analysis, Paradigm analysis, Perturbation analysis, Planning analysis, Ploidy analysis
, Quantal analysis, Quantitative trait loci association analysis, RAPD analysis, Replacement analysis, Restriction analysis, Risk analysis
, ROC analysis
, Root cause analysis, S phase analysis
, Semen analysis
, Sensitivity analysis, Signature pattern analysis, Single-strand conformation polymorphism analysis, Sister chromosome exchange analysis, Slot blot analysis, Spectral analysis, Survival analysis
, SWOT analysis, Synovial fluid analysis
, Task analysis
, Temporal analyisis, Time series analysis, Tree-structured survival analysis, Univariate analysis, VNTR analysis, Volume-outcome analysis
, Workflow analysis Medtalk The assessment of the individual components of a process or substance Psychiatry Psychoanalysis, see there. See Ego analysis, Freudian analysis, Jungian psychoanalysis analysis, Psychoanalysis
, Psychometric analysis, Transactional analysis
Deviation of results or inferences from the truth resulting from flaws in the analysis or interpretation of results. See Bias
analysis of variance
ANOVA Statistics An analytical method used for continuous variables, which determine whether the source of variability among 3 or more data sets is due to true differences in the sets or due to random variations or 'statistical noise'; ANOVA compares the means of several random variables, assuming that each has a normal distribution with the same variance; these algorithms are quite complex and are usually computer-based. See Statistics
Lab medicine The concentration at which the mean response is statistically beyond the noise limits of the signal at zero concentration. See Sensitivity
. Cf Functional sensitivity.
analytic epidemiology Epidemiology The aspect of epidemiology concerned with identifying health-related causes and effects; AE uses comparison groups, which provide baseline data, to quantify the association between exposures and outcomes, and test hypotheses about causal relationships
analytical psychology Psychiatry The name given by psychoanalyst Carl Jung for his system, which minimizes the influences of sexual factors in emotional disorders and stresses mystical religious influences and a belief in the collective unconscious. See Freudian psychology.
anamnesis Psychiatry The developmental history of a Pt and of his/her illness; the act of remembering
anaphylactic reaction Anaphylaxis Clinical immunology An antigen-induced, IgE-mediated release–and production—of chemical mediators, the target of which is blood vessels and smooth muscle Pathogenesis An AR is a hypersensitivity reaction that follows re-exposure to an antigen to which the body has previously formed an IgE antibody; within seconds of exposure to the antigen(s), which may be proteins, polysaccharides, and haptens, IgE molecules cross-link on the surface of mast cells and basophils, stimulating vesicle degranulation and release of LBW mediators of anaphylaxis; in the 1º response, preformed molecules are released, including eosinophil chemotactic factor, and vasoactive substances–eg, heparin, histamine, serotonin, and various enzymes; in the 2º response, acute phase reactants are produced and released; fatal and near-fatal ARs in children are commonly evoked by peanuts > nuts > eggs, milk, fish, and others Clinical Bronchospasm, dyspnea, hypotension, edema, shock, and possibly death Management Epinephrine ASAP. See Acute phase reactants. Cf Anaphylactic shock, Anaphylactic reaction.
anaphylactic shock Immunology An extreme manifestation of an allergic reaction, which is characterized by ↓ blood pressure, shock–poor tissue perfusion and difficulty breathing. See Anaphylactic reaction.
anaphylactoid purpura Henoch-Scho¨nlein purpura, see there.
anaphylactoid reaction Immunology An anaphylaxis-like reaction that occurs without an allergen-IgE antibody event, which is caused by a nonimmune release–eg reaction to radiocontrast, chymopapain, aspirin, of vasoactive and inflammatory mediators, including histamine. Cf Anaphylactic reaction.
An often aggressive epithelial malignancy that lacks the histologic criteria required to confirm its embryologic lineage; ACs lack architectural landmarks and are classified based on the cell type, divided into small cell, intermediate cell, giant cell
, spindle cell and mixed cell types; ACs occur in the lungs, thyroid and rarely elsewhere Prognosis Poor–anaplasia implies that the tumor is 'primitive'; ACs are often aggressive and have a variable response to excision, chemotherapy
, radiotherapy Pancreas A rare variant of 'garden variety' pancreatic ductal adenocarcinoma, which affects ♀ > age 50 Prognosis Poor, < 6 months Thyroid A rare, rapid growing and invasive form of thyroid cancer, which affects those > age 60 Etiology Unknown, possibly linked to radiation exposure Clinical Hoarse voice, cough
, tracheal obstruction; physical exam may reveal nodules in thyroid Lab Thyroid function is usually normal Diagnosis Biopsy Treatment Surgery ± RT
Anapsique Amitryptiline, see there.
anaptic adjective Referring to an impaired sense of touch
anastomosis Surgery 1. Any opening between 2 normally separate spaces, lumina, or organs, regardless of the manner–surgical, traumatic or pathological—in which the opening was created 2. The surgical connection between 2 tubular structures–eg, end-to-end anastomosis of the colon or rectum after a cancerous segment has been excised, or end-to-side anastomosis of a saphenous vein during a CABG
anastomotic adjective Referring to a surgical connection of 2 luminal–tubular structures
Oncology An aromatase inhibitor, which converts androstenedione to estradiol in peripheral fat Indications Postmenopausal ♀ with advanced estrogen-dependent breast CA that does not respond to tamoxifen; unlike tamoxifen, anastrozole is not associated with ↑ risk of endometrial CA. See Breast cancer
. Cf Tamoxifen
anatomic snuffbox Anatomy A triangular depression on the dorsal pollicar aspect of the hand when the thumb is fully extended
anatomical imaging Structural imaging, see there.
anatomical position An erect body stance with the eyes directed interiorly, the arms at the sides, palms of the hands facing interiorly, and fingers pointing straight down; anatomists and clinicians use the AP to build hypothetical biomechanical models of normalcy in which to describe movement of the center of gravity
The study of bodily structures and their relationships with each other. See Gross anatomy
, Regional anatomy, Surgical anatomy
ANCA Antineutrophil cytoplasmic antibody, see there.
Surgery A small suture used for ligament repair of small joints. See Suture
anchovy paste appearance
Parasitology A fanciful descriptor for the olive-brown or creamy white grumous material seen in hepatic and cerebral amebiasis—Entamoeba histolytica
, composed of autolyzed necrotic debris and hemorrhage. See Amebiasis
Inpatient care Any of a broad range of services–eg phone, TV–that are outside of the routine room and board charges incidental to a hospital stay Outpatient care Health services–eg, in-office lab testing, imaging–mammography and other support services, which are not procedures or medical services, which relate to medical practice See Added-value service, Ambulatory surgery
, Room & board.
Graduate education Any form of support that eases Pt management workload–eg, hospital information system, Pt and specimen transport services, nursing support, consulting services, etc. See Call schedule
anconeus musculus anconeus Anatomy Origin Lateral epicondyle of humerus and adjacent capsule of elbow joint Insertion Olecranon and posterior surface of ulna. Action Extends elbow and abducts ulna in pronation Nerve Radial
ANCOVA Analysis of covariance Statistics The use of grouped regression analysis, which ensures that comparisons of the variates between 2 groups are not be confounded by possible differences in covariates
Parasitology The only hookworm found in the US, which enters the body as a 3rd
-stage larva through breaks in the skin—eg bare feet in contact with contaminated soil; once in the circulation, larvae migrate to the pulmonary alveoli, where they are coughed up, swallowed, then enter the duodenum and attach themselves to villi Clinical Intense pruritus, erythema
, and a vesicular rash at the site of larval penetration, anemia
, malnutrition Management Mebendazole; iron for anemia
ANDA Abbreviated new drug application, see there.
Andersen disease Glycogen storage disease IV, see there.
Anderson clamp MD Anderson clamp, see there.
Androgenic hormone Endocrinology Any natural or synthetic 'male' hormone–eg, testosterone, methyltestosterone, fluoxymesterone, danazol, which promotes the development and maintenance of ♂ sex characteristics; natural androgen is produced chiefly by the testis, but also by the adrenal cortex and, in small amounts, by the ovary Therapeutic indications Manage androgen deficiency, delayed puberty in ♂ and some forms of breast CA. See Androgen replacement therapy, Dihydrotestosterone
androgen ablation Androgen suppression Oncology The therapeutic ↓ of circulating androgens-testosterone and 5α-dihydrotestosterone by either orchiectomy or by an LHRH agonist; AA is commonly used in metastatic prostate CA and results in a response, albeit short-lived–12-18 months of up to 80% of Pts; AA can be augmented by flutamide, an androgen receptor antagonist that blocks the effect of androgens produced by the adrenal gland. See Androgen-independent prostate cancer.
Endocrinology A relative or absolute paucity of androgens. See Androgen replacement therapy.
- Prepubertal AD
- Delayed onset of puberty; caused by cryptorchidism, bilateral torsion of the testes, orchitis, vanishing testis syndrome, orchidectomy, 1º testicular failure–eg Klinefelter syndrome, anorchia, and other conditions
- Adult AD
- Regression of androgen-dependent activities, fatigue and loss of energy, somatic changes, eg relative ↓ in lean body mass and skeletal muscle, ↑ fat, sexual behavior–impotence, erectile dysfunction, ↓sexual desire, and regression of 2º sexual characteristics
androgen-independent prostate cancer
Oncology A form of prostate CA characterized by metastases, aggressive clinical behavior, and a poor response to androgen ablation; most AIPCs express high levels of androgen receptor gene transcripts, which may be due to androgen receptor mutations. See Androgen ablation, Orchiectomy
, Prostate cancer
androgen-induced hermaphroditism Endocrinology A hermaphroditic sexual defect induced in a 46, XY gonadal ♀ fetus by excess masculinizing hormone transmitted from the mother through the placenta
androgen insensitivity syndrome Incomplete testicular feminization, partial androgen resistance, testicular-feminizing syndrome Urology A common–1/500 births–condition characterized by a genotypic–46,XY ♂ and a phenotypic ♀ identical to genotypic ♀; AIS have groin masses corresponding to testes or absent/sparse pubic and axillary hair Pathogenesis Cells are unresponsive to androgens, not to estrogen; masculine internal development is incomplete; externally, genitalia are ♀, except for a blind vagina, which can be made functional by either dilation or surgical lengthening; these genotypic ♂ are amenorrheic and infertile, but have phenotypic ♀ breasts
androgen replacement therapy
Endocrinology The administration of androgens–eg, testosterone or its congeners in a ♂ with hypogonadal androgen-deficiency, which may be 1º or 2º, and either congenital or acquired; the intent of ART is to restore normal physiologic effects of testosterone, which depend on the stage of sexual development; in androgen-deficient boys, the goal of ART is to initiate and maintain androgen-dependent activities including somatic development–eg, development of skeletal muscle and ↑ strength, long bone growth, redistribution of body fat, and erythropoiesis, sexual behavior–↑ libido and potency, and development of 2º sexual characteristics–eg, ♂ pattern of hair growth, penile and scrotal enlargement, laryngeal enlargement and thickening of the vocal cords and deepening of the voice. See Androgen ablation, Orchiectomy
, Prostate cancer
androgen resistance–complete Testicular feminization, see there.
androgen resistance–partial Androgen insensitivity syndrome, incomplete testicular feminization Andrology An X-R endocrinopathy that affects a heterogeneous group of X,Y individuals Clinical Ambiguous external genitalia, hypoplastic testes, ↓ 'male' hair Lab ↑ LH, testosterone, estrogen, estradiol; ± ↑ FSH Pathogenesis Peripheral androgen resistance due to quantitative or qualitative defects in the androgen receptor
androgeic alopecia Common baldness, female pattern hair loss, male pattern baldness Dermatology Hereditary thinning of hair induced by androgens in genetically susceptible ♂ and ♀, which begins between age 12 and 40 in
± 50% of the general population Mechanism Dihydrotestosterone binds to androgen receptor of susceptible scalp hair follicles, activating genes that gradually transform large terminal hair follicles to miniature follicles, producing finer hair in shorter hair cycles; dihydrotestosterone is formed by peripheral conversion of testosterone by one of 2 isoforms of 5α-reductase which, with other enzymes, regulate specific steroid transformations in skin; those with AA have ↑ 5α-reductase, ↑ androgen receptors, ↓ cytochrome
P-450 aromatase, which converts testosterone to estradiol in hair follicles in the frontal scalp Management Finasteride, minoxidil. See Hair replacement therapy, Male-pattern baldness, Terminal hair.
androgenital syndrome Congenital adrenal hyperplasia, see there.