Glossary - D

Diabetes Insipidus

Diabetes Insipidus has two inherited forms are known: a sex linked recessive and an autosomal dominant. This disease occurs mainly in males at a rather young age. This disease is manifested by polyuria, pale urine, dehydration, constipation, and dryness of skin. The main diagnostic procedures are via urine, CT brain scan, and spinal tap. This condition usually lasts for life. Transient forms with spontaneous recovery are sometimes observed after trauma or neurosurgery. The development of resistance or allergy to vasopressin complicates treatment. Therapy frequently consists of replacement treatment with vasopressin or chlorothiazide.

Diabetes Mellitus

Diabetes Mellitus, Type I, is strongly associated with certain HLA antigens-B8, BW 15, DW 3, and with islet cell antibodies. Type I diabetes results from an infection or toxic environmental insult to pancreatic B cells of genetically predisposed individuals. In this form, circulating insulin is absent. Type II is transmitted as an autosomal dominant trait on chromosome 11. In this type, circulating insulin is sufficient to avoid ketosis, but inadequate in the face of increased needs due to tissue insensitivity. Signs and symptoms of the disease include: polyuria, thirst, enuresis, increased appetite and loss of weight, premature loosening of the teeth, impotence, and somnolence. Both sexes are equally vulnerable. Treatment for the disease consists of eating a correct diet and avoiding obesity, vitamin B complex, and insulin therapy. Several complications may arise as a result of diabetes mellitus, ranging from acute ketosis to insulin allergy to ocular disorders.

Delirium tremens

Delirium tremens is a severe alcohol withdrawal syndrome characterized by agitation, violence, anxiety, insomnia muscle cramps, tremor, delusion, hallucinations, ataxia, fever, with clearing beginning in 12-24 hours up to 2-1 0 days. The main cause is a cessation in alcohol consumption after heavy alcohol ingestion.

Depression

Depression is a mood or affective disorder characterized by sadness, dysphoria, hopelessness, despair personal devaluation and helplessness. (An affective disorder refers to a condition involving the external expression of an internal state). Some depressions are marked by anxiety, withdrawal from others, loss of appetite or compulsive eating, loss of sexual desire, lethargy or agitation, an inability to concentrate and make decisions and possibly exaggerated guilt feelings or thoughts. Depression can appear at any age, although major depressive episodes peak at age 55 to 70 in men and 20 to 45 in women. Recent studies have shown a trend for earlier onset of depression, especially in females. About 20% of major depressions last two years or more with an average duration of two months. About half of those experiencing a major depression will have a recurrences within two years. Estimates are that 2 to 3 percent of men and 4 to 9 percent of women suffer a major depression at any given time in the United States.

Diarrhea, acute

Acute diarrhea, is the sudden onset of diarrhea in a healthy individual. Fever, chills, headache, anorexia, myalgia frequent passing of watery stools vomiting abdominal pain, and malaise are all common signs and symptoms of this infectious process. Two common types of acute diarrhea are acute viral diarrhea, which effects the morphology of the small intestine cell, and bacterial diarrhea, which is diarrhea caused by a toxin. The Gastrointestinal system along with the Endocrine and Metabolic systems can all be affected which involves all age groups. It can be caused by bacterial factors including E.coli, Salmonella, Shigella, Campylobacter jejuni, Vibrio parahemolyticus, Vibrio cholera and Yersina enterocolitica. Viral factors such as Rotavirus, and Norwalk virus, as well as Parasitic factors like Giardia lamblia, Cryptospordium, and Entamoeba histolytica may also cause acute diarrhea.

Diarrhea, chronic

Chronic diarrhea is the too frequent passage of stool that are loose for an extended period of time. It is a fairly common illness, effecting all age groups and is more common in females then males. Some of the signs and symptoms of chronic diarrhea include: more frequent defecation than normal, defecation of lesser consistency that normal, the repeated urgency to defecate, a fear of incontinence, and lower abdominal cramping before and during defecation. Some of the rare symptoms include; a occasional incontinence of stools, weight loss, and depletion of fluid and electrolytes. The onset of chronic diarrhea may be caused by motility disturbance, osmosis of fluid into the enteric lumen, secretory "drive" of electrolytes and fluid from enterocytes into the intestinal lumen, injury to the electrolytes, or occasionally, a persistent enteric infection. Chronic use of laxatives, chronic alcohol consumption, severe diabetes mellitus, previous surgery, emotional turmoil, dietary aids, and even the AIDS/HIV infection are all risk factors associated with chronic diarrhea.

Diphtheria

Diphtheria is an acute respiratory tract infection caused by Corynebacterium. The incubation period varies between two and five days, and it is transmitted by the respiratory route from an infected individual. Membranous pharyngotonsillar diphtheria, nasal diphtheria, obstructive laryngotracheitis and cutaneous diphtheria are among the common forms of the disease. The Pulmonary, Skin, Cardiac, and Nervous systems can all be affected. The incidence is equal among both genders and is more common among children, younger than 15 years of age as well as among poorly immunized adults. Some of the signs and symptoms for the membranous pharyngotonsillat diphtheria include; a white yellowish membrane which is easily removed, sticky whitish-gray, leathery membrane on the tonsils or pharynx, an injected pharynx, sore throat, cervical adenopathy with swelling, malaise and prostration, enlarged tender cervical submandibular lymph nodes, swollen neck, paralysis of soft palate, a low fever, and a Thrombocytopenia and purpura. The symptoms of nasal diphtheria include: Serosanguineous or seropurulent discharge and excoriations, a unilateral discharge, and an often chronic mild course.

Diploid

Diploid-the number of chromosomes in most somatic cells. In humans the diploid number is 46.

Discordant

Discordant-a twin pair in which one member exhibits a certain trait and the other does not.

DNA

DNA-the polymer of which eukaryotic genes are composed of.

DNA Ligase

DNA Ligase-the enzyme that catalyzes relegation of two fragments of DNA.

DNA Polymerase

DNA Polymerase-the enzyme responsible for the replication of DNA, which is accomplished by using each complimentary strand of the DNA double helix as a template for the synthesis of a new strand.

Dominant Trait

Dominant Trait-those conditions that are expressed in heterozygotes.

Down's Syndrome

Down's Syndrome is a common form of mental retardation. It is caused by a genetic defect and the probabilities of its occurrence increases with the mother's age at birth. . While the cause is unknown, all patients have extra chromosome 21 material. This material manifests itself in three forms, trisomy 21, translocation 21, and Mosaic 21. The Nervous, Cardiovascular, and Skin/Endocrine systems are all effected by this disease which is found at birth and encountered in one of every 800 births. There is an equal incidence among the sexes. Some of the signs and symptoms include: brachycephaly, hypotonia, posterior third fontanel, small ears, mongoloid eyes, epicanthic folds, speckled spots on the iris, Esotropia, an enlarged tongue, a small chin, a short neck, abnormal dermatoglyphics, a developmental delay, and in some cases a cardiac murmur can be detected. With the exception of brachycephaly, most of the symptoms listed above become milder with age.

 

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