15 Nomenclature

Some molecules may occur with identical atoms in the same sequence but with different spatial arrangements. These are referred to as stereoisomers. A stereoisomer that is nonsuperimposable on its mirror image is chiral, and an atom with 4 different substituents is a chiral center; the 2 mirror images are enantiomers. An equal mixture of the 2 enantiomers is racemic. Generally only 1 enantiomer is biologically active, as in the case of ibuprofen. In some cases, one enantiomer may be biologically beneficial while the other enantiomer is harmful. For example, one enantiomer of thalidomide is a beneficial drug whereas the other ...Less

Symbols and their subgrouping into main symbols and modifiers are consistent with approved nomenclature formulated circa 1980 by the Commission of Respiratory Physiology (International Union of Physiological Sciences) and the Publications Committee of the American Physiological Society., The following groupings of pulmonary-respiratory symbols are adapted from Fishman.Main symbols are typically capital letters set on the line and are the first elements of an expression. The same letter may stand for one entity in respiratory mechanics and another in gas exchange (eg, P stands for pressure in respiratory mechanics and partial pressure in gas exchange). The following are examples (note dots ...Less

The following terms are commonly used in radiology.b value The b factor or b value is associated with diffusion-weighted magnetic resonance imaging (diffusion-weighted MRI or DWI). It measures “strength (intensity and timing) of the diffusion gradient”; units are seconds per square millimeter.maximum b value of 1221 s/mm2 Four gradient strengths were applied, resulting in b values of 0 and 1000 s/mm2 applied sequentially in the X, Y, and Z gradient directions.Doppler See , Cardiology, Echocardiography.echo train A sequence of echoes. “Echo train is not a unit of measure” but is expressed as in these examples: echo train length 5 echo ...Less

The TNM staging system is an internationally standardized system for the staging of cancer and is in its seventh decade of continuing formulation. The TNM classification is put forth by the American Joint Committee on Cancer (AJCC) and the International Union Against Cancer (UICC; http://www.uicc.org). The AJCC’s Cancer Staging Manual and the UICC’s TNM Classification of Malignant Tumours present the stages of cancer as defined by TNM classifications. The TNM definitions and stage groupings are based on prognostic outcome. Information about TNM may be accessed at the UICC website, http://www.uicc.org/index.php?id=508. The TNM symbols follow.▪ T: tumor (indicates size, extent, or ...Less

The letters in this expression indicate obstetric history as follows:Often, 4 numbers separated by hyphens are recorded, eg: TPAL: 3 1-1-4 or 3-1-1-4which would indicate 3 term deliveries, 1 premature delivery, 1 abortion, and 4 living children. However, the text of a manuscript should define the numerical expressions and not give the numbers alone. ...Less

Drugs occasionally become known by an unofficial trivial name. The trivial name should be used in biomedical publications only to reproduce the exact language used as part of a study (eg, in a questionnaire), for historical reasons, or rarely when readers may be unfamiliar with the nonproprietary name. When reproducing the exact language used in a study, the nonpropietary name should be provided in brackets after the term used in the study.The participants were asked, “Have you ever taken AZT [zidovudine] or ddI [didanosine]?” Participants who said they had taken zidovudine or didanosine were classified as having had prior exposure ...Less

The abbreviation ul (for uniformly labeled) may be used without expansion in parentheses: [14C]glucose (ul)Similarly, terms such as carrier-free, no carrier added, and carrier added may be used. In general medical publications, these terms should be explained at first mention, since not all readers will be familiar with them. ...Less

Viruses evolve rapidly…. [A]denovirus, for example,may produce 250 000 DNA molecules in an infectedcell….  Leslie Collier and John Oxford(p12) Taxonomy lies at the uneasy interface betweenbiology and logic.   L. Andrew Ball(p3) If you wanted to call one of your children home fordinner would you go into the street and shout “Homosapiens”?   Michael A. Drebot, Eric Henchal,    Brian Hjelle, et al(p2468)Most medical articles describe concrete viral entities and, therefore, use the common (vernacular, informal) names of viruses (eg, cytomegalo-virus, Hantaan virus, orthopoxviruses). To indicate taxonomic groups, formal virus names are used (eg, Human herpesvirus 5, Hantaan virus, the genus Orthopox-virus).A virus term that ends in ...Less

The familiar letter names of most vitamins generally refer to the substances as found in food and in vivo. With the exception of vitamins A, E, and B complex, the INNs for vitamins given therapeutically differ from their in vivo names. (To enhance clarity for readers, the equivalent vitamin name may also be provided.) Various types of carotenoids (alpha and beta carotene and beta cryptoxanthin) may be converted to vitamin A within the body, so the specific agent that is administered should be provided. The native form of vitamin A is most often supplied as retinol acetate. Other forms of ...Less