Glossary (A-D)

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A

Acidosis, Respiratory
A state due to excess carbon dioxide in the body. (Dorland, 27th ed)

Acquired Immunodeficiency Syndrome
An acquired defect of cellular immunity associated with infection by the human immunodeficiency virus (HIV), a CD4-positive T -lymphocyte count under 200 cells/microliter or less than 14% of total lymphocytes, and increased susceptibility to opportunistic infections and malignant neoplasms. Clinical manifestations also include emaciation (wasting) and dementia. These elements reflect criteria for AIDS as defined by the CDC in 1993.

Acute
Severe or has a sudden onset and a short timespan.

Addison's Disease
A disease characterized by hypotension, weight loss, anorexia, weakness, and sometimes a bronze-like melanotic hyperpigmentation of the skin. It is due to tuberculosis- or autoimmune-induced disease (hypofunction) of the adrenal glands that results in deficiency of aldosterone and cortisol. In the absence of replacement therapy, it is usually fatal.

Adenoids
Lymphoid tissue that normally exists in the nasopharynx of children and is known as the pharyngeal tonsil. (Dorland, 28th ed)

Adrenal Glands
These glands are located at the top of each kidney. They produce hormones that control many important functions. Cortisol is a hormone that is secreted in a cyclical fashion daily. It is also secreted in times of infection and stress. Other hormones help regulate various minerals that are important for the normal function of the body.

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Advance Directive
A written document that states a person's healthcare choices and names someone to make those choices, should the person become unable to make their own decisions about medical care. The most common types of advance directives are a living will and a durable power of attorney for healthcare.

Aerosol
A solution of a medication that is fluid droplets suspended in air and delivered as a mist or spray.

Agammaglobulinemia
An immunologic deficiency state characterized by an extremely low level of generally all classes of gamma- globulin in the blood.

AIDS (Acquired Immune Deficiency Syndrome)
A secondary immune deficiency caused by HIV infection.

AIDS Dementia Complex
Neurological syndrome characterized by abnormalities in cognition, motor performance, and behavior. It is partially or wholly due to a direct effect of the HIV virus on the brain rather than to opportunistic infection. Pathological findings include diffuse white matter pallor, multinucleated-cell encephalitis, and vacuolar myelopathy. Clinical manifestations may include apathy, mental slowing, and progressive paraparesis.

AIDS-Associated Nephropathy
Renal syndrome in human immunodeficiency virus-infected patients characterized by nephrotic syndrome, severe proteinuria, focal and segmental glomerulosclerosis with distinctive tubular and interstitial changes, enlarged kidneys, and peculiar tubuloreticular structures. The syndrome is distinct from heroin-associated nephropathy as well as other forms of kidney disease seen in HIV-infected patients.

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AIDS-Related Complex
A prodromal phase of infection with the human immunodeficiency virus (HIV). Laboratory criteria separating AIDS-related complex (ARC) from AIDS include elevated or hyperactive B-cell humoral immune responses, compared t? depressed or normal antibody reactivity in AIDS; follicular or mixed hyperplasia in ARC lymph nodes, leading to lymphocyte degeneration and depletion more typical of AIDS; evolving succession of histopathological lesions such as localization of Kaposi's sarcoma, signaling the transition to the full-blown AIDS.

AIDS-Related Opportunistic Infections
Opportunistic infections found in patients who test positive for human immunodeficiency virus (HIV). The most common include Pneumocystis carinii pneumonia, Kaposi's sarcoma, cryptosporidiosis, herpes simplex, toxoplasmosis, cryptococcosis, and infections with Mycobacterium avium complex, Microsporidium, and Cytomegalovirus.

Air Trapping
This is the air caught behind collapsed bronchials during expiration.

Airway Collapse
Collapse or closure of branches of the bronchi. The collapse is caused by weakened bronchial walls that is the result of disease.

Airway Obstruction
A narrowing or blocking of the passages that carry air into the lungs. COPD is classified as an obstructive airway disease.

Airways
Passageways that carry oxygen into the lungs and carbon dioxide out of the lungs.

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Aleutian Mink Disease
A slow progressive disease of mink caused by the Aleutian Mink Disease virus. It is characterized by poor reproduction, weight loss, autoimmunity, hypergammaglobulinemia, increased susceptibility to bacterial infections, and death from renal failure. The disease occurs in all color types, but mink which are homozygous recessive for the Aleutian gene for light coat color are particularly susceptible.

Alkalosis, Respiratory
A state due to excess loss of carbon dioxide from the body. (Dorland, 27th ed)

Alpha1-Antitrypsin Deficiency
Alpha-1-anititrypsin is a protein that circulates in the blood and protects tissues from being damaged by enzymes (chemicals) in the white blood cells. The enzymes normally perform valuable and important functions. The function of enzymes must be strictly controlled so they do not attack normal tissues. Alpha-1 antitrypsin is one of the body's mechanisms of keeping these enzymes in check.

Alpha-1-antitrypsin deficiency is a rare inherited condition in which the alpha-1 antitrypsin produced is abnormal (although it works well) and the amount is much lower compared with most other people. The production of alpha-1 normally increases in response to infections and other biological stresses. With Alpha-1- deficiency, there is no appreciable increase in the blood levels of alpha-1 in these situations.

The deficiency is harmful to the liver and lungs. Alpha-1 is made in the liver cells and cause health problems. It can cause cirrhosis (degeneration that causes the lobes to become fibrous and accumulate fat) of the liver. There is no cure for the progressive liver damage and can only be treated with a liver transplant.

The primary function, though of alpha-1 is to protect the lungs from the white blood cells enzymes. These enzymes digest old or damaged cells and bacteria to help with healing. With a deficiency of alpha-1 antitrypsin, the enzymes attack and digest tissue lung tissue particularly the tiny air sacs called alveoli and causes emphysema in the lower parts of the lungs. This inherited type of emphysema causes symptoms in people who are 30-40 years of age. There is no cure, however there are treatments for the symptoms and there is a replacement therapy that may slow or halt the destruction in the lungs. Prolastin, purified alpha-1 antitrypsin, is a treatment available for some people with alpha-1 antitrypsin deficiency.

Alpha-1 antitrypsin deficiency is detected by measuring the blood level of alpha-1 antitrypsin. Testing is recommended for people who have relatives diagnosed with alpha-1 or there is a family history of early emphysema.

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Alveolitis, Extrinsic Allergic
Conditions in which inhalation of organic dusts results in hypersensitivity reactions at the alveolar level, associated with the production of precipitins.

Alveolus
Alveoli (pleural for alveolus) are tiny, thin-walled air sac at the end of the bronchiole branches where oxygen crosses the capillaries into the bloodstream and carbon dioxide crosses from the bloodstream into the alveoli to be exhaled.

Amyloid Neuropathies
Disorders of the peripheral nervous system associated with deposition of amyloid. Amyloid neuropathies may result from non-hereditary or hereditary amyloidosis. Several different forms of familial amyloid neuropathies have been described, most of which have specific mutations in the prealbumin gene.

Amyloidosis
A group of conditions of diverse etiologies characterized by the accumulation of insoluble fibrillar proteins (amyloid) in various organs and tissues of the body such that vital function is compromised. The associated disease states may be inflammatory, hereditary, or neoplastic, and the deposition can be localized or generalized or systemic. (Dorland, 27th ed)

Anaphylaxis
Systemic or generalized anaphylaxis, anaphylactic shock, a manifestation of immediate hypersensitivity in which exposure of a sensitized individual to a specific antigen or hapten results in life-threatening respiratory distress usually followed by vascular collapse and shock and accompanied by urticaria, pruritus, and angioedema. Common agents causing anaphylaxis include Hymenoptera venom, pollen extracts, certain foods, horse and rabbit sera, heterologous enzymes and hormones, and certain drugs, such as penicillin and lidocaine. (Dorland, 27th ed)

Anemia, Hemolytic, Autoimmune
Acquired hemolytic anemia due to the presence of autoantibodies which agglutinate or lyse the patient's own red cells.

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Angioneurotic Edema
Recurring attacks of transient edema suddenly appearing in areas of the skin or mucous membranes and occasionally of the viscera, often associated with dermatographism, urticaria, erythema, and purpura.

Anthracosilicosis
A mixed condition of anthracosis and silicosis. (Dorland, 27th ed)

Anti-inflammatory
Anti-inflammatory drugs are drugs used to reduce inflammation - the redness, heat, swelling, and increased blood flow found in infections and in many chronic non-infective diseases.

Anti-Glomerular Basement Membrane Disease
Glomerulonephritis, usually of a generalized proliferative crescent-forming histologic type with a rapidly progressive course, marked by circulating anti-GBM antibodies and linear deposits of immunoglobulin and complement along the glomerular basement membrane. When associated with pulmonary hemorrhage the condition is called GOODPASTURE SYNDROME. (Dorland, 28th ed)

Antibiotic
A medication that interferes with the growth of a bacteria and may stop an infection. Antibiotics do not help with disease caused by viruses like the flu.

Antibody
Protein molecules that are produced and released by certain types of white blood cells (lymphocytes) in response to a "foreign invader" or antigen. Their primary function is to fight bacteria, viruses, toxins, and other substances foreign to the body.

Antibody-Producing Cells
Cells of the lymphoid series that can react with antigen to produce specific cell products called antibodies. Various cell subpopulations, often B-lymphocytes, can be defined, based on the different classes of immunoglobulins that they synthesize.

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Anticholinergic
Drugs that block the effects of acetylcholine, a substance produced by the body, which is responsible for parasympathetic nervous system activities. Anticholinergic medications block the secretion of acid in the stomach, slow the passage of food through the digestive system, inhibit the production of saliva, sweat, and bronchial secretions, and increase the heart rate and blood pressure. The medications are used as bronchodilators in COPD to dilate (widen) the airways.

Antigen
Any substance that, as a result of coming in contact with appropriate cells, induces a state of sensitivity and/or immune responsiveness after a latent period (days to weeks) and which reacts in a demonstrable way with antibodies and/or immune cells of the sensitized subject in vivo or in vitro. (Stedman's Medical Dictionary, 26th Edition)

Antigen-Presenting Cells
Heterogeneous group of immunocompetent cells that mediates the cellular immune response by processing and presenting antigens to the T-cell receptor. Traditional antigen-presenting cells include MACROPHAGES, DENDRITIC CELLS, LANGERHANS CELLS, and B-L YMPHOCYTES.

Antiphospholipid Syndrome
The presence of antibodies directed against phospholipids. The condition is associated with a variety of diseases, notably systemic lupus Erythematosus and other connective tissue diseases, thrombopenia, and arterial or venous thromboses. In pregnancy it can cause abortion. Of the phospholipids, the cardiolipins show markedly elevated levels of anticardiolipin antibodies. Present also are high levels of lupus anticoagulant.

Aphonia
Loss of voice.

Apnea
Absence or cessation of breathing. (Stedman, 25th ed; Dorland, 27th ed)

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Argon Plasma Coagulation
A technique used to control bleeding by desiccating (drying) the tissue and blood vessels in it.

Arrhythmia
Arrhythmias (abnormal heart beats) are caused by a disruption of the normal functioning of the electrical conduction system of the heart. Normally, the atria and ventricles contract in a coordinated manner. Arrhythmias result in ineffective and uncoordinated contractions of the heart muscle and may cause a rapid or irregular pulse. Arrhythmias may cause decreased cardiac output, and failure to pump enough blood to meet the needs of the body. Some causes of arrhythmias are coronary artery disease, rheumatic heart disease, hypertension, and acute myocardial infarction. Hyperthyroidism and some medications may also cause arrhythmia.

Arterial Blood Gas -A test that analyses arterial blood for oxygen, carbon dioxide, pH (acidity), and bicarbonate levels. This measurement is used to determine the effectiveness of gas exchange and acid-base balance. Abnormal results may indicate respiratory, metabolic, or renal disease. Normal arterial blood gas values are a pH of 7.32-7.45, PaO2 (oxygen) 80-98 mmHg, PCO2 (carbon dioxide) 35-45 mmHg and SaO2 (oxygen saturation) 96-98%. In most cases, abnormal ABG results correlate with abnormal lung function results. However, normal ABG results can also be found in someone with severe lung disease, and very abnormal ABG results can be sound in someone with minor lung problems.

Arthritis, Juvenile Rheumatoid
Rheumatoid arthritis of children occurring in three major subtypes defined by the symptoms present during the first six months following onset: systemic-onset, and pauciarticular-onset. Adult-onset cases of Still's disease (STILL'S DISEASE, ADULT-ONSET) are also known. Only one subtype of juvenile rheumatoid arthritis (polyarticular-onset, rheumatoid factor-positive) clinically resembles adult rheumatoid arthritis and is considered its childhood equivalent.

Arthritis, Rheumatoid
A chronic systemic disease, primarily of the joints, marked by inflammatory changes in the synovial membranes and articular structures, widespread fibrinoid degeneration of the collagen fibers in mesenchymal tissues, and by atrophy and rarefaction of bony structures. Etiology is unknown, but autoimmune mechanisms have been implicated.

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Arthus Reaction
A dermal inflammatory reaction produced under conditions of antibody excess, when a second injection of antigen produces intravascular antigen-antibody complexes which bind complement, causing cell clumping, endothelial damage, and vascular necrosis.

Arytenoid Cartilage
One of a pair of small pyramidal cartilages that articulate with the lamina of the cricoid cartilage. The corresponding vocal ligament and several muscles are attached to it.

Asbestosis
A form of lung disease (pneumoconiosis) caused by inhaling fibers of asbestos and marked by interstitial fibrosis of the lung varying in extent from minor involvement of the basal areas to extensive scarring. It is associated with pleural mesothelioma and bronchogenic carcinoma. (Dorland, 27th ed)

Aspergillosis, Allergic Bronchopulmonary
Aspergillosis of the lung occurring in an individual with long-standing bronchial asthma. It IS characterized by pulmonary infiltrates, eosinophilia, elevated serum IgE and immediate type skin reactivity to aspergillus antigen.

Asthma
Asthma is a chronic lung condition. During an asthma "attack" individuals experience labored breathing, wheezing, and/or coughing. During an asthmatic episode, the airway tubes become narrowed because of the excess production of mucus, swelling of the airway lining, or tightening of the muscles around the airways. The narrowing of the airways is reversible and can be completely relieved with bronchodilators.

Asthma, Exercise-Induced
Asthma attacks following a period of exercise. Usually the induced attack is short-lived and regresses spontaneously. The magnitude of postexertional airway obstruction is strongly influenced by the environment in which exercise is performed (i.e. inhalation of cold air during physical exertion markedly augments the severity of the airway obstruction; conversely, warm humid air blunts or abolishes it).

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Asthmatic Bronchitis
A condition where asthma and chronic bronchitis exist together.

Ataxia Telangiectasia
A syndrome characterized by choreoathetosis beginning in childhood, progressive cerebellar ataxia, telangiectasis of conjunctiva and skin, slowly progressive mental deterioration and increasing cerebellar degeneration.

Atelectasis
Collapse of all or part of a lung due to bronchial plugging or the chest cavity being opened to atomspheric pressure.

Atopic
Relating to allergy or an allergic condition.

Autoimmune Diseases
A disorder caused by an immune response directed against self antigens. Ideally there should be not only demonstrable circulating autoantibodies or cell-mediated immunity against autoantigens in conjunction with inflammatory lesions caused by immunologically competent cells or immune complexes in tissues containing the autoantigens, but also clinical or experimental evidence that the autoimmune process is pathogenic, not secondary to other tissue damage. In practice many diseases, such as systemic lupus Erythematosus and rheumatoid arthritis, are otten classified as autoimmune diseases although their pathogenesis is unclear. (Dorland, 27th ed)

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B

B-Lymphocyte Subsets
A classification of B-lymphocytes based on structurally or functionally different populations of cells.

B-Lymphocytes
Lymphoid cells concerned with humoral immunity. They are short-lived cells resembling bursa-derived lymphocytes of birds in their production of immunoglobulin upon appropriate stimulation.

Bacteria
A single-celled organism that can cause infections and are usually treated with antibiotics.

Balloon Bronchoplasty
In this procedure, small balloons are used to stretch open the airways that are narrowed due to scarring, tumors or granulation tissue.

Barrel Chest
The shape of a chest in some patients with COPD. The shape is due to air trapping causing overly inflated lungs and the chest wall to be pushed out.

Basophils
Granular leukocytes characterized by a relatively pale-staining, lobate nucleus and cytoplasm containing coarse, dark-staining granules of variable size and stainable by basic dyes.

Berylliosis
A lung disease caused by exposure to metallic beryllium or its soluble salts. Bird Fancier's Lung A respiratory disorder due to an acquired hypersensitivity to the dust of bird droppings.

Beta2-Agonist
A drug that blocks the effects of the sympathetic nervous system chemicals that cause the airways to narrow. Beta2-agonists help the bronchial muscle tissue to relax and help open up the airways.

BiPAP
A machine which administers air under pressure via a mask to keep the airways open and unobstructed.

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Blood Group Incompatibility
A mismatch between donor and recipient blood. Antibodies present in the recipient's serum are directed against antigens in the donor product. Such a mismatch may result in a transfusion reaction in which, for example, donor blood is hemolyzed. (From Saunders Dictionary & Encyclopedia of Laboratory Medicine and Technology, 1984)

Blood Pressure
Force by the blood on the walls of the main arteries of the body. Blood pressure measurements are made both during contraction of the ventricles of the heart (systolic) and when the ventricles are at rest (diastolic). When the blood pressure is too high it is termed hypertension. When the blood pressure is too low it is termed hypotension.

Blood-Air Barrier
The barrier between capillary blood and alveolar air comprising the alveolar epithelium and capillary endothelium with their adherent basement membranes and epithelial cell cytoplasm. Gaseous exchange occurs across this membrane.

Bone Marrow
The soft tissue filling the cavities of bones. Bone marrow exists in two types: yellow and red. Yellow marrow is found in the large cavities of large bones and consists mostly of fat cells and a few primitive blood cells. Red marrow is a hematopoietic tissue and is the site of production of erythrocytes and granular leukocytes. Bone marrow is made up of a framework of connective tissue containing branching fibers with the frame being filled with marrow cells.

Bone Marrow Transplant
Bone marrow is removed from a healthy donor and given to the immune deficient through an IV.

Bone Mineral Density (BMD)
This test measure the amount of bone tissue in a certain volume of bone. The measurement is obtained with a special x-ray machine. The disease osteoporosis is diagnosed when the bone density is below a certain amount.

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Bradypnea
Decreased breathing rate, usually less than 10 breaths per minute.

Bronchi
The larger air passages of the lungs arising from the terminal bifurcation of the trachea.

Bronchial Diseases
Disorders of the bronchi, general or unspecified.

Bronchial Fistula
An abnormal passage or communication between a bronchus and another part of the body.

Bronchial Hyperreactivity
Tendency of the smooth muscle of the tracheobronchial tree to contract more intensely in response to a given stimulus than it does in the response seen in normal individuals. This condition is present in virtually all symptomatic patients with asthma. The most prominent manifestation of this smooth muscle contraction is a decrease in airway caliber that can be readily measured in the pulmonary function laboratory.

Bronchial Neoplasms
Neoplasms or tumors of the bronchial tree.

Bronchial Spasm
Spasmodic contraction of the smooth muscle of the bronchi.

Bronchiectasis
In this condition there is chronic inflammation or degeneration of the bronchi or bronchioles. The walls of the bronchi are dilated (widened) and the bronchial walls have lost their elasticity (they are no longer pliable). The condition develops after frequent serious respiratory infections and is often accompanied by sinusitis, chronic cough and bloody sputum.

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Bronchioles
The tiny branches of air tubes within the lungs that are the continuation of bronchi and connect to the alveoli.

Bronchiolitis
Inflammation of the bronchioles.

Bronchiolitis Obliterans
Inflammation of the bronchioles with obstruction by fibrous granulation tissue or bronchial exudate. It may follow inhalation of irritating gases or foreign bodies and it complicates pneumonia.

Bronchiolitis Obliterans Organizing Pneumonia
A disease formerly considered a form of interstitial pneumonia. Its etiology is obscure but it may be associated with toxic fumes, infection, and connective tissue disease. Clinical symptoms include cough, dyspnea and influenza-like symptoms with the development of the usual inters.titial pneumonia in many cases. Obstructive symptoms are limited to smokers. There are patchy polypoid masses of Intra-alveolar granulation tissue in small airway lumina and alveolar ducts. "Organizing" refers to unresolved pneumonia (in which the alveolar exudate persists and eventually undergoes fibrosis) in which fibrous tissue forms in the alveoli. (From Segen, Dictionary of Modern Medicine, 1992; Stedman, 25th ed)

Bronchiolitis, Viral
An acute inflammatory disease of the upper respiratory tract, caused by paramyxoviruses, occurring primarily in infants and young children; the viruses most commonly implicated are parainfluenza type 3 and respiratory syncytial virus.

Bronchitis
Chronic or acute inflammation of the mucous membrane of the bronchial tubes. There is excess mucus secretion along with a cough and sputum production. This can cause narrowing and obstruction of the airway. Not all people with bronchitis, even chronic bronchitis develop COPD.

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Bronchogenic Cyst
A usually spherical cyst, arising as an embryonic out-pouching of the foregut or trachea. It is generally found in the mediastinum or lung and is usually asymptomatic unless it becomes infected.

Bronchoconstriction
A tightening of the muscles that surround the bronchi and leads to narrowing of the airway.

Bronchodilator
A medication that relaxes the smooth muscles of the bronchi and opens (widens) constricted (narrowed) airways.

Bronchopneumonia
Acute inflammation of the walls of the smaller bronchial tubes, with varying amounts of pulmonary consolidation due to spread of the inflammation into peribronchiolar alveoli and the alveolar ducts. (Stedman, 25th ed)

Bronchopulmonary Dysplasia
A chronic lung disease appearing in certain newborn infants treated for RESPIRATORY DISTRESS SYNDROME with mechanical ventilation and elevated concentration of inspired oxygen.

Bronchopulmonary Sequestration
A developmental anomaly in which a mass of nonfunctioning lung tissue lacks normal connection with the tracheobroncheal tree and receives an anomalous blood supply originating from the descending thoracic or abdominal aorta. The mass may be extralobar, i.e., completely separated from normally connected lung, or intralobar, i.e., partly surrounded by normal lung.

Bronchoscopy
Bronchoscopy is a technique for examining the airways of the lungs. Using a flexible tube the width of a pencil (called a bronchoscope), physicians are able to explore the trachea, main stem bronchi, and some of the small bronchi. The bronchoscope has a video camera and a biopsy instrument on one end. You are admitted to special procedures and have an intravenous (IV) line placed. The doctor sprays numbing medicine into the back of your throat to make it easier for the bronchoscope to be placed. You will probably be given some medication through the IV to relax you as well. The doctor places the bronchoscope in your mouth and advances it into your throat and trachea. This procedure does not interfere with your ability to breathe. The doctor can see into your lungs by watching a screen that shows the view from the end of the bronchoscope. He can also take a sample of sputum or biopsy the lung tissue. At the end of the test the bronchoscope is removed. The test usually takes 30 minutes to one hour.

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Bronchus
Either of the two main branches of the airway (right and left) that connect the trachea (windpipe) with the lungs.

Burkitt Lymphoma
A form of undifferentiated malignant lymphoma usually found in central Africa, but also reported in other parts of the world. It is commonly manifested as a large osteolytic lesion in the jaw or as an abdominal mass. B-cell antigens are expressed on the immature cells that make up the tumor in virtually all cases of Burkitt lymphoma. The Epstein-Barr virus has been isolated from Burkitt lymphoma cases in Africa and it is implicated as the causative agent in these cases; however, most non-African cases are EBV-negative.

Bursa of Fabricius
A lymphoid organ of birds that, like the thymus, develops as an epithelial outpouching of the gut but near the cloaca rather than the foregut. It atrophies at five or six months of age, persisting as a fibrous remnant in sexually mature birds. Before involution it is the site of maturation of B-lymphocytes. (Dorland, 27th ed)

Byssinosis
An airway obstruction due to the dust inhaled during the processing of cotton.

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C

Caplan's Syndrome
Pneumoconiosis associated with rheumatoid arthritis.

Carbon Dioxide (CO2)
This gas is produced by the tissues as a waste product, and carried in the blood to the lungs to be exhaled. In the lungs CO2 is exchanged for oxygen (02).

Carcinoma, Bronchogenic
A cancer of the lung, so-called because it arises from the epithelium of the bronchial tree. It is not a histologic designation despite the name.

Cardiolopulmonary
Referring to the heart and lungs.

CD4-Positive T-Lymphocytes
A critical subpopulation of regulatory T -lymphocytes involved in the induction of most immunological functions. The HIV virus has selective tropism for the T4 cell which expresses the CD4 phenotypic marker, a receptor for HIV. In fact, the key element in the profound immunosuppression seen in HIV infection is the depletion of this subset of T -lymphocytes, which includes both the helper-inducer (T -LYMPHOCYTES, HELPER-INDUCER) and suppressor-inducer (T -LYMPHOCYTES, SUPPRESSOR-INDUCER) T -cells.

CDS-Positive T-Lymphocytes
A critical subpopulation of regulatory T -lymphocytes involved in MHC Class I-restricted interactions. They include both cytotoxic T -lymphocytes (T -L YMPHOCYTES, CYTOTOXIC) and suppressor T -lymphocytes (T- LYMPHOCYTES, SUPPRESSOR-EFFECTOR).

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Cerebral Amyloid Angiopathy
A pathological condition characterized by the deposition of amyloid in the walls of small vessels in the cerebral cortex and meninges. This biochemically heterogeneous entity is most commonly associated with stroke, Alzheimer's disease, Down's syndrome, and miscellaneous neurologic conditions. Cerebral hemorrhage is common in persons with this condition.

Chediak-Higashi Syndrome
A form of phagocyte bactericidal dysfunction characterized by unusual oculocutaneous albinism, high incidence of Iymphoreticular neoplasms, and recurrent pyogenic infections. In many cell types, abnormal Iysosomes are present leading to defective pigment distribution and abnormal neutrophil functions. The disease is transmitted by autosomal recessive inheritance and a similar disorder occurs in the beige mouse, the Aleutian mink, and albino Hereford cattle.

Chest X-Ray (CXR)
Chest x-rays are often done on people with COPD. The signs of COPD do not sure up on x-rays in the early stages. As the disease progresses there are specific signs that are common. Emphysema changes on chest x-rays include:

  • A flattened diaphragm
  • Abnormally large air spaces in the lungs
  • Hyperinflated lungs in the upper areas
  • Small heart (unless heart failure is present)

Cheyne-Stokes Respiration
The pattern of breathing with gradual increase in depth and sometimes in rate to a maximum, followed by a decrease resulting in apnea. The cycles ordinarily are 30 seconds to two minutes in duration, with five to 30 seconds of apnea. It is characteristically seen in coma from disorders of the nervous centers of respiration. (Stedman, 25th ed)

Choanal Atresia
Congenital bony or membranous occlusion of one or both choanae, due to failure of the embryonic bucconasal membrane to rupture.

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Chronic
Diseases or disorders show little changes in symptoms from day to day, but the disease process continues and causes progressive deterioration.

Chronic Bronchitis
Chronic bronchitis is defined as the presence of a chronic cough and overproduction of sputum (phlegm) for at least three months a year for at least two successive years. Not all chronic bronchitis is classified as COPD. Chronic bronchitis that causes irreversible obstruction to airflow (COPD) is due to structural changes within the airway from inflammation. Symptoms of chronic bronchitis include:

  • Coughing with excessive sputum production
  • Shortness of breath with activity that progresses over time to shortness of breath at rest
  • Dyspnea (unable to catch your breath) when lying down as the disease progresses, and requires sleeping in a chair
  • Bluish tinge to skin (cyanosis) because of low oxygen levels in the blood (hypoxemia)
  • Swelling from fluid accumulation caused by congestive heart failure

Chronic Granuloma Disease of Childhood
In this disease, the phagocytes are unable to kill certain "foreign invaders".

Chyle
The milky substance taken up by the lacteals (intestinal lymphatics) from the food in the intestine during digestion. It consists of lymph and droplets of triglyceride fat in a stable emulsion. It passes into the veins by the THORACIC DUCT, becoming mixed with blood. (From Dorland, 27th ed)

Chylothorax
The presence of chyle in the thoracic cavity. (Dorland, 27th ed)

Cilia
In healthy lungs, cilia (tiny hairs that line the lungs) move bacteria, pollutants, and other irritants upwards toward the oral up the airway so they can be expelled (coughed or breathed out). The cilia in people with COPD are damaged and cannot perform this function well enough or at all.

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Ciliary Motility Disorders
Disorders characterized by abnormal ciliary movement in the nose, paranasal sinuses, respiratory tract, and spermatozoa. Electron microscopy of the cilia shows that dynein arms are missing. The disorders manifest as Kartagener triad (KARTAGENER'S SYNDROME), chronic respiratory disorders, chronic sinusitis, and/or chronic otitis.

Coin Lesion, Pulmonary
Solitary, round, circumscribed shadows found in the lungs in x-ray examinations. Common causes are tuberculosis, neoplasms, cysts, or vascular anomalies. (Stedman, 25th ed)

Common Cold
A catarrhal disorder of the upper respiratory tract, which may be viral, a mixed infection, or an allergic reaction. It is marked by acute coryza, slight rise in temperature, chilly sensations, and general indisposition.

Common Variable Immunodeficiency
Heterogeneous group of immunodeficiency syndromes characterized by hypogammaglobulinemia of most Isotypes, variable B-cell defects, and the presence of recurrent bacterial infections.

Complement
Blood proteins that help destroy "foreign invaders" like bacteria, viruses, and fungi.

Complete BLood Count (CBC)
A Complete Blood Count (CBC) is a blood test that evaluates the cells of the blood. It includes the WBC (white blood cell) count, RBC (red blood cell) count, a platelet count, hemoglobin count and hematocrit (volume of red cells in blood). A differential count of the white blood cells is also included. The CBC is the basic test to determine whether there is infection and/or bleeding.

Computerized Axial Tomography Scan (CAT or CT Scan)
An x-ray procedure that uses a computer to produce a series of three dimensional images of the body and it's organs.

Congenital
Congenital conditions are conditions a person is born with.

Conjunctivitis, Allergic
Conjunctivitis due to hypersensitivity to various allergens.

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COPD (Chronic Obstructive Pulmonary Disease)
A slowly progressive disease of the airways of the lungs that is characterized by gradual loss of lung function. The disease is an umbrella term that includes chronic bronchitis, emphysema, or combinations of both conditions. People who develop COPD have no symptoms until 50% of their lung function is damaged. As the disease progresses, people experience exacerbations that are characterized by:

  • Worsening shortness of breath (dyspnea).
  • Increased amount of sputum.
  • Thick, purulent sputum.

COPD decreases one's quality of life and limits one's activities. Eventually bathing, brushing teeth, even eating cause increasing dyspnea. As the disease progresses, oxygen and carbon dioxide exchange becomes more and more impaired. The blood has a low oxygen level (hypoxia) and a high carbon dioxide level (hypercapnea). The body tries to overcome these changes with:

  • Increased breathing rate to breath in more oxygen and breath out more carbon dioxide
  • Increased number of red blood cells to carry more oxygen in the blood
  • Increased heart rate to pump more oxygen to the tissue

COPD can have frequent exacerbations and the development of serious and life-threatening conditions including acute respiratory failure, pulmonary hypertension (high blood pressure in the vessels of the lungs) and an impaired ability to think and remember things.

Cor Pulmonale
Heart disease that is caused by high pressure in the pulmonary blood vessels (pulmonary hypertension). The disease is characterized by an enlarged right ventricle wall (right ventricular hypertrophy) and right heart failure.

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Corticosteroids
Cortisone-like medicines are used to provide relief for inflamed areas of the body. They lessen swelling, redness, itching, and allergic reactions. They are often used as part of the treatment for a number of different diseases, such as severe allergies or skin problems, asthma, or arthritis. In lung transplant patients, corticosteroids may form part of immunosuppressive therapy to control the response of the patient's immune system to the donor heart, and promote tolerance of the implanted organ. The trade-off, however, is that corticosteroids may lower your resistance to infections, and any infection you get may be harder to treat. Always check with your doctor as soon as possible if you notice any signs of a possible infection, such as sore throat, fever, sneezing, or coughing.

Cough
A sudden noisy expulsion of air from the lungs, usually produced to keep the airways of the lungs free of foreign matter. (Dorland, 28th ed)

Cricoid Cartilage
The small thick cartilage that forms the lower and posterior parts of the laryngeal wall.

Croup
A condition characterized by resonant barking cough, hoarseness and persistant stridor and caused by allergy, foreign body, Ifection, or neoplasm. It occurs chiefly in infants and children.

Cryoglobulinemia
A condition characterized by the presence of abnormal or abnormal quantities of cryoglobulins in the blood. They are precipitated into the microvasculature on exposure to cold and cause restricted blood flow in exposed areas.

Cyanosis
Cyanosis develops in people who have a poor supply of oxygen in their blood (hypoxemia). The oxygen that can be delivered to their tissues is also poor and they develop a bluish tinge to their skin, lips, mucus membranes, and nailbeds.

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Cystic Adenomatoid Malformation of Lung, Congenital
A developmental anomaly that usually becomes apparent in the neonatal period with progressive respiratory distress. This malformation is a focal pulmonary dysplasia characterized by a multicystic mass of terminal bronchiolar structures. CCAM is classified into three separate types (I, II, III) depending on cyst size.

Cystic Fibrosis
An inherited disease of exocrine glands, affecting most characteristically the pancreas, respiratory system, and sweat glands, usually beginning in infancy and typified by chronic respiratory infections, pancreatic insufficiency, and susceptibility to heat prostration. Cirrhosis of liver occurring in childhood is common and may produce portal hypertension, splenomegaly, and hypersplenism.

D

Dendritic Cells
Immunocompetent cells of the lymphoid and hemopoietic systems and skin. They are also called interdigitating, reticular, and veiled cells. They function morphologically and phenotypically by presenting or processing antigens, thereby stimulating cellular immunity.

Dermatitis Herpetiformis
Rare, chronic, papulo-vesicular disease characterized by an intensely pruritic eruption consisting of various combinations of symmetrical, erythematous, papular, vesicular, or bullous lesions. The disease is strongly associated with the presence of HLA-B8 and HLA-DR3 antigens. A variety of different autoantibodies has been detected in small numbers in patients with dermatitis herpetiformis.

Dermatitis, Allergic Contact
A contact dermatitis due to allergic sensitization to various substances. These substances subsequently produce inflammatory reactions in the skin of those who have acquired hypersensitivity to them as a result of prior exposure.

Dermatitis, Atopic
A chronic inflammatory genetically determined disease of the skin marked by increased ability to form reagin (lgE), with increased susceptibility to allergic rhinitis and asthma, and hereditary disposition to a lowered threshold for pruritus. It is manifested by lichenification, excoriation, and crusting, mainly on the flexural surfaces of the elbow and knee. In infants it is known as infantile eczema.

Dermatitis, Photoallergic
A delayed hypersensitivity involving the reaction between sunlight or other radiant energy source and a chemical substance to which the individual has been previously exposed and sensitized. It manifests as a papulovesicular, eczematous, or exudative dermatitis occurring chiefly on the light-exposed areas of the
skin.

Dermatitis, Toxicodendron
An allergic contact dermatitis caused by exposure to plants of the genus Toxicodendron (formerly Rhus). These include poison ivy, poison oak, and poison sumac, all plants that contain the substance urushiol, a potent skin sensitizing agent. (From Dorland, 27th ed)

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Diabetes Mellitus, Insulin-Dependent
Diabetes mellitus characterized by insulin deficiency, sudden onset, severe hyperglycemia, rapid progression to ketoacidosis, and death unless treated with insulin. The disease may occur at any age, but is most common in childhood or adolescence.

Diaphragm
A thin, dome-shaped sheet of muscle that inserts into the lower ribs; it is the most important muscle of inspiration. When the diaphragm contracts, it moves downward, lowers pleural pressure, and allows air to enter the lungs.

DiGeorge Syndrome
Congenital syndrome with the absence of the thymus and parathyroids causing impairment of cellular immunity. Immunoglobulin levels are normal.

Drug Eruptions
Adverse cutaneous reactions caused by ingestion, parenteral use, or local application of a drug. These may assume various morphologic patterns and produce various types of lesions.

Drug Hypersensitivity
Immunologically-mediated adverse reactions to medicinal substances used legally or illegally.

Dry Powder Inhaler (DPI)
Dry powder inhalers deliver a measured dose of medication into the lungs and are similar to metered dose inhalers. Inhaling causes the medication to be released in the form of a dry powder.

Duration
How long to do an activity.

Dysgammaglobulinemia
An immunologic deficiency state characterized by selective deficiencies of one or more, but not all, classes of immunoglobulins.

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Dyspnea
Dyspnea or shortness of breath (SOB) is difficulty in breathing. It is often associated with lung or heart disease. Dyspnea is also called air hunger. Dyspnea is the reason many people with COPD become debilitated. Debilitation is a vicious cycle in the patient with COPD. When moderate exertion causes shortness of the breath, the tendency is to avoid those types of activity. This lack of activity causes muscles to weaken. Soon, the weak muscles use more oxygen than the stronger ones. As this happens, dyspnea occurs with mild exercise. Now the tendency is to avoid any kind of exercise. As your body becomes weaker, dyspnea occurs with activities of daily living (ADL) such as bathing or dressing and even at rest. Dyspnea affects the quality of life for people with COPD. The extent of COPD can be graded by the type of activities that cause dyspnea.

Dyspnea, Paroxysmal
A form of respiratory distress related to posture (especially reclining at night) and usually attributed to congestive heart failure with pulmonary edema. It appears suddenly at night, usually wakening the patient after an hour or two of sleep. It is also called paroxysmal nocturnal dyspnea. (From Dorland, 27th ed; Stedman, 25th ed)

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