Vitamin Glossary "D"

• de-differentiation:-loss by mature cells of some of their specialized properties and reversion to a less developed state. De-differentiation is a normal part of healing and regeneration. De-differentiation is also often a part of the early development of tumors.

   

• demulcent- an herb that is rich in mucilage and soothes and protects irritated or inflamed tissue. Demulcent herbs reduce irritation down the whole length of the bowel; reduce sensitivity to potentially corrosive gastric acids; help prevent diarrhea and reduce the muscle spasms that cause colic.

   

• demyelination- reduction of the fatty covering of the nerves, removal of the myelin sheath.

   

• dental amalgam- an alloy containing mercury, tin, silver, and copper that is used in dentistry to restore teeth.

   

• dehydroascorbic acid-toxic oxidized from of vitamin C (ascorbic acid); it is a pro-oxidant rather than antioxidant.

   

• dermatitis- inflammation of the skin with itching, redness, and various skin lesions.

   

• desensitization- the treatment of allergies by repeated injections of dilute solutions containing the allergen. Slowly promotes tolerance of the antigen by the immune system.

   

• detoxification- the process of removing toxins from the body.

   

• diastolic-the part of the heartbeat cycle during which blood pressure is lowest, when the heart is relaxed; if you have a blood pressure of 115/70, 70 is your diastolic blood pressure.

   

• diastolic pressure- the period of least pressure in the arterial vascular system.

   

• differentiation-a genetic clock program of cellular development with time. Cells begin with the ability to turn into many different tissue types; through the process of differentiation, they become more and more specialized in function and generally retain the properties of cells of a specific type of tissue.

   

• diffusion-a passive form of random movement in which areas of high chemical concentration gradually spread throughout an entire system, equalizing the chemical concentration over the system. For example, the exchange of gases in the lungs occurs by simple diffusion across capillary walls.

   

• dimethylbenzanthracene-a type of polynuclear aromatic hydrocarbon, a tarry carcinogenic substance produced during the combustion of fuels.

   

• disulfide bond- a sulfur to sulfur bond found in both normal and abnormal cross-linked proteins, bonding a protein to parts of the same molecule of to other molecules. These bonds provide the three dimensional structure of molecule containing them. Latex is vulcanized to form rubber by the controlled formation of disulfide bonds.

   

• diuretic- a substance which increases the production and elimination of urine.

   

• diverticulitis- inflammation of a sac or pouch in the intestinal tract, most commonly in the colon region, causing stagnation of feces and pain.

   

• DMSO-dimethyl sulfoxide, a hydroxyl radical-scavenging solvent that rapidly penetrates the skin.

   

• DNA-deoxyribonucleic acid, the genetic material, encoding full plans for how living organisms are constructed and how they function. Damage to DNA is believed to be a central feature of both aging and cancer.

   

• L-Dopa-precursor to dopamine.

   

• dopamine- an amino acid found in the adrenal gland. Used to treat hypotension and Parkinson's disease.

   

• dopaminergic-those parts of the nervous system in the brain which use dopamine as neurotransmitter.

   

• doshas- the three basic types of biological humors in Ayurvedic medicine, which determine an individual's constitution.

   

• dosimeter-a device for measuring accumulated exposure to x-rays, gamma rays, or other hazardous radiation.

   

• double blind-a technique used in modern scientific research to separate facts from the hopes and wishes of both scientists and experimental subjects. A treatment which is to be tested is administered by scientists who do not know whether they are using the active treatment or the inactive placebo. The experimental subjects don't know which is which, wither. The test results are evaluated by scientists who also do not know which group received the active treatment and which the placebo. At the end of the experiment, the secret code is broken, and the responses of the subjects to the real experimental treatment are compared with their responses to the placebo.

   

• duodenal ulcer- damaged mucous membrane in a portion of the small intestine.

   

• dyspepsia- imperfect or painful digestion.