HIV Human immunodeficiency virus, the cause of AIDS. HIV is a retrovirus: It has an RNA genome and a reverse transcriptase enzyme. Using the reverse transcriptase, the virus uses its RNA as a template for making complementary DNA. This DNA can then integrate itself into the DNA of the host organism. Also known as the…
His-Werner disease See trench fever.
history, social An account of a patient that puts his or her illness or behavior in context. A social history may include aspects of the patient’s developmental, family, and medical history, as well as relevant information about life events, social class, race, religion, and occupation.
history, medical A complete account of all past and present medical events and problems a person has experienced, including psychiatric illness.
history, family An account of past and current family structure and relationships within the family, including medical information about family members.
history, developmental An account of how and when a child passed developmental milestones, such as walking and talking. For adults, information on social-emotional development may be included. A developmental history is used primarily in the diagnosis of developmental disorders.
history See history, medical.
histoplasmosis A disease caused by the fungus Histoplasma capsulatum. Most people with histoplasmosis have no symptoms. However, it can cause acute or chronic lung disease and progressive disseminated histoplasmosis, which affects a number of organs. Infants, young children, and older persons—particularly those with chronic lung disease—are at increased risk for severe disease. Disseminated histoplasmosis is…
Histoplasma capsulatum A fungus that is found worldwide that is particularly common in the central and eastern parts of the US. It is carried in bird and bat droppings, and it is deposited in the soil. Although people can contract histoplasma from their environment, it cannot be passed from person to person. While most persons…
histone A protein around which DNA coils to form chromatin. Without histones, DNA could not organize into chromosomes.
histology The study of tissues as seen under a microscope. Also known as microscopic anatomy, as opposed to gross anatomy.
histocompatible Literally, tissue compatible, meaning that the tissue can exist together with tissue of another organism without the immune system rejecting it. If a tissue donor and tissue recipient are histocompatible, a transplant is expected to be easily accepted.