kala-azar A chronic and potentially fatal parasitic disease of the viscera (the internal organs, particularly the liver, spleen, bone marrow, and lymph nodes) due to infection by the parasite Leishmania donovani. Leishmania donovani is transmitted by sandfly bites in parts of Asia (primarily India), Africa (primarily Sudan), and South America (primarily Brazil). Kala-azar can cause…
Kaposi sarcoma A relatively rare type of skin malignancy that tends to affect elderly people and those with an abnormal immune system, as in AIDS. Kaposi sarcoma is caused by human herpesvirus 8 (HHV-8), which may be transmitted via kissing. Kaposi sarcoma is a highly vascular (angioblastic) tumor of the skin, characterized by soft purplish…
Kartagener syndrome A genetic syndrome that is characterized by sinusitis, bronchiectasis (widening and inflammation of the bronchi), dextrocardia (heart on the right side of the chest), and infertility. Kartagener syndrome is inherited in an autosomal recessive manner. Kartagener syndrome is usually due to mutation in the gene called DNAI1 on chromosome 9. However, linkage studies…
karyotype A standard arrangement of the chromosome complement prepared for chromosome analysis. A normal female karyotype would include each of the 22 pairs of autosomes (nonsex chromosomes), arranged in numeric order, together with the two X chromosomes.
karyotyping The preparation, analysis, and interpretation of a karyotype.
karyotyping, flow See flow karyotyping.
Kawasaki disease A syndrome that mainly affects young children, causing fever; reddening of the eyes (conjunctivitis), lips, and mucous membranes of the mouth; ulcerative gum disease (gingivitis); swollen glands in the neck (cervical lymphadenopathy); and a rash that is raised and bright red (maculoerythematous). The rash appears in a “glove-and-sock” fashion over the skin of…
jejunal Having to do with the jejunum.
A jejunostomy is a surgical procedure in which an opening (stoma) is created in the jejunum (a part of the small intestine), which is then brought to the surface of the abdomen. This operation is typically performed when there is a need for long-term enteral nutrition, bypassing the stomach, or in cases where the upper…
jejunum The middle portion of the small intestine. The jejunum is about 2.4 meters (8 feet) in length and located halfway between the duodenum and the ileum. The jejunum is responsible for much of the absorption of the fluids and calcium that we ingest. See also intestine; intestine, small.
jellyfish sting The injection into the skin of venom from the stinging unit (nematocyst) of the jellyfish. The jellyfish tentacles can extend for several feet and are lined with venom-filled cells (nematocysts). One tentacle may fire thousands of nematocysts into the skin on contact. The pain can be severe, particularly in the first hours after…
jet lag A temporary disorder that features fatigue and insomnia and that is caused when the body’s natural rhythms are interrupted by rapid travel across time zones. Other symptoms of jet lag include anxiety, constipation, diarrhea, confusion, dehydration, headache, irritability, nausea, sweating, coordination problems, and even memory loss. See also circadian clock.