| cross reaction | <haematology, immunology> Serological reactions in which an antiserum against one antigen reacts with a non-identical but closely related antigen. (12 Dec 1998) |
|---|---|
| cross-reactive antibody | <haematology, immunology> Antibodies which don't respond to any one specific antigen, but will respond to a number of them. These antibodies can be responsible for false positive results in antigen-antibody tests. (09 Oct 1997) |
| cross-resistance | <immunology, microbiology> Immunologic resistance to the pathogenic effects of a microorganism because of previous exposure to another species or type having cross reactive antigens. This phenomenon is seen in microbes that acquire resistance to one drug through direct exposure and turn out to have resistance to one or more other drugs to which it has not been exposed. Cross-resistance arises because the mechanism of resistance to several drugs is the same and arises through the identical genetic mutations. (09 Oct 1997) |
| cross-section | <physics> Usually refers to the (apparent) area presented by a target particle to an oncoming particle (or electromagnetic wave). This measures the probability of an interaction occuring. For typical interactions between ions and electrons, or between two nuclei, these cross sections are generally measured in barns. <anatomy> A transverse cut through a structure or tissue. The opposite of a cross-section is a longitudinal section. By analogy, a study may be cross-sectional or longitudinal. (12 Dec 1998) |
| cross-sectional echocardiography | two-dimensional echocardiography |
| cross-sectional method | <epidemiology> The study of the life span involving comparison of groups of individuals at different age levels. Compare: longitudinal method. (05 Mar 2000) |
| cross-sectional study | <epidemiology> A study in which the presence or absence of disease or other health-related variables are determined in each member of the study population or in a representative sample at one particular time. This contrasts with longitudinal studies which are followed over a period of time. Synonym: horizontal study. (18 Jul 2002) |
| cross-table lateral projection | <radiology> Lateral projection radiography of a supine subject using a horizontal X-ray beam. (05 Mar 2000) |
| cross tolerance | <pharmacology> The resistance to one or several effects of a compound as a result of tolerance developed to a pharmacologically similar compound. (05 Mar 2000) |
| section, cross | A transverse cut through a structure. The opposite is a longitudinal section. (12 Dec 1998) |
| holy cross | The cross as the symbol of Christ's crucifixion. Congregation of the Holy Cross, a community of lay brothers and priests, in France and the United States, engaged chiefly in teaching and manual Labour. Originally called Brethren of St. Joseph. The Sisters of the Holy Cross engage in similar work. Holy-cross day, the fourteenth of September, observed as a church festival, in memory of the exaltation of our Savior's cross. Source: Websters Dictionary (01 Mar 1998) |
| study, cross-sectional | A study done at one time, not over the course of time. A cross-sectional study a disease such as aids might be designed to learn its prevalence and distribution within the population at one point in time. Also known as a synchronic study. (12 Dec 1998) |
| double back cross | A mating that is a back cross at each of two loci of interest; of special value and importance in linkage analysis. (05 Mar 2000) |
| International Committee of the Red Cross | A neutral Swiss organization serving as an intermediary between contending forces in armed conflict, in civil war, or internal strife, to help victims receive protection and other humanitarian assistance under the Geneva Conventions in accordance with the fundamental principles of the Red Cross. (05 Mar 2000) |
| test cross | Crossing of an unknown genotype to a recessive homozygote so that the phenotype of the progeny corresponds directly to the chromosomes carried by the parents of unknown genotype. In experimental genetics, a deliberate mating designed to test claims about the pattern of inheritance of one or more traits. Synonym: backcross. (05 Mar 2000) |