(dī-fŏs′fă-tĭ-dĭl-glĭs′ĕr-ŏl) An extract of beef hearts that contains phosphorylated polysaccharide esters of fatty acids. It is used in certain tests for syphilis.
(dī″fŏs-fō-glĭs′ĕr-āt″) ABBR: 2,3-DPG. An organic phosphate in red blood cells that alters the affinity of hemoglobin for oxygen. Blood cells stored in a blood bank lose 2,3-diphosphoglycerate, but once they are infused, the substance is resynthesized or reactivated.
(dif-thēr′ē-ă) [Gr. diphthera, hide, membrane + -ia] A rare, contagious, toxin-mediated bacterial disease marked by the formation of a patchy grayish-green membrane over the tonsils, uvula, soft palate, and posterior pharynx. Occasionally the skin, conjunctiva, ears, GI and urinary tracts are involved. In cutaneous diphtheria, impetiginous lesions occur. The membrane is created by a thick, inflammatory exudate. SEE: antitoxin; exotoxin; sepsis; diphtheria toxoid. diphtherial (dif-thēr′ē-ăl), adj.
INCIDENCE: An effective vaccination program has made the incidence of the disease rare in the U.S., except among those groups of people who do not receive immunizations. The lack of virulent strains to reinforce immunity, however, has resulted in loss of immunity in some older adults. In the 1920s, before vaccination, about 200,000 cases of diphtheria were reported annually. The current incidence is about 1 case per year.
CAUSES: The causative organism is Corynebacterium diphtheriae. Airborne droplets transmit the organism from person to person (usually from asymptomatic carriers or convalescent patients). More people carry the disease than actually contract an active infection. The incubation period is 2 to 5 days and occasionally longer.
IMMUNIZATION: Immunization is by administration of three doses at least 4 weeks apart, beginning at 2 months of age. Diphtheria toxoid (inactivated exotoxin capable of stimulating antibody production) is given in combination with pertussis vaccine (usually acellular pertussis) and tetanus toxoid; a fourth dose is given 1 year later. Booster doses are administered if a child under 6 years old or other close family member is exposed to diphtheria. Because effective immunity does not last longer than 10 years after the last vaccination, people should receive a booster of diphtheria toxoid every 10 years. Immunity to diphtheria is assessed by measuring antibody levels in the blood.
SYMPTOMS AND SIGNS: Patients present with fever, malaise, cervical lymphadenopathy, sore throat, raspy cough, hoarseness, and other croup-like symptoms. A tough yellow-white or gray-green pseudomembrane forms in the throat. It contains cellular debris and fibrin and, unlike the exudate caused by streptococci, is difficult to remove and can obstruct air flow. If not treated it may result in stridor, suprasternal retractions, tachypnea, cyanosis, and death by suffocation. As the bacteria multiply, they produce a potent exotoxin that prevents protein synthesis in cells. Once the exotoxin has spread to the bloodstream, signs of sepsis ...