Untitled - D Ank Unlimited

carbon clearance test 134 cardiac disease, autoimmune
effect against several different allogeneic and syngeneic
tumors without mediating cytotoxicity of the tumor cells.
Mannans derived from yeast also exert significant antitumor
effects, as do levans that activate not only macrophages but B
and T cells as well. Pectin is a galactose-containing carbohydrate
concentrated in citrus and has an antitumor effect.
carbon clearance test
An assay to judge mononuclear phagocyte system activity
in vivo. Blood samples are collected at designated intervals
following the intravenous inoculation of a colloidal carbon
particle suspension. Following dissolution of the erythrocytes
in blood samples, their carbon particle content is
determined colorimetrically. This permits determination
of the rate at which blood phagocytes remove carbon. The
logarithms of the readings in the colorimetry are plotted
against time to yield the desired slope.
Carcinoembryonic antigen (CEA).
Carcinoembryonic antigen (CEA)⎯carcinoma of the colon.
carcinoembryonic antigen (CEA)
A 200-kDa membrane glycoprotein epitope present in the fetal
gastrointestinal tract under normal conditions. However, tumor
cells, such as those in colon carcinoma, may re-express it. CEA
was first described as a screen for identifying carcinoma by
detecting nanogram quantities of the antigen in serum. It was
later shown to be present in certain other conditions. CEA levels
are elevated in almost one third of patients with colorectal,
liver, pancreatic, lung, breast, head and neck, cervical, bladder,
medullarythyroid, and prostatic carcinoma. However, the level
may also be elevated in patients with malignant melanoma or
lymphoproliferative disease and in smokers. Regrettably, CEA
levels also increase in a variety of non-neoplastic disorders
including inflammatory bowel disease, pancreatitis, and cirrhosis
of the liver. Nevertheless, determination of CEA levels in
the serum is valuable for monitoring the recurrence of tumors
in patients whose primary neoplasm has been removed. A CEA
level elevated 35% compared to the level immediately following
surgery may signify metastases. This oncofetal antigen is comprised
of one polypeptide chain with one variable region at the
amino terminus and six constant region domains. CEA belongs
to the immunoglobulin superfamily. It lacks specificity for
cancer, thereby limiting its diagnostic usefulness. It is detected
with a mouse monoclonal antibody directed against a complex
glycoprotein antigen present on many human epithelial-derived
tumors. This reagent may be used to aid in the identification of
cells of epithelial lineage. The antibody is intended for qualitative
staining in sections of formalin-fixed, paraffin-embedded
tissue. Anti-CEA antibodies specifically bind to antigens located
in the plasma membrane and cytoplasmic regions of normal
epithelial cells. Unexpected antigen expression or loss of expression
may occur, especially in neoplasms. Occasionally, stromal
elements surround heavily stained tissue and/or cells that show
immunoreactivity. Clinical interpretation of any staining or its
absence must be complemented by morphological studies and
evaluation of proper controls.
carcinogen
Any chemical or physical agent that produces cancer
through mutation or deregulating oncogenes, tumor-suppressor
genes, or DNA repair genes. Carcinogens are of two
types: (1) the epigenetic type that does not damage DNA
but causes other physiological alterations that predispose to
cancer, and (2) the genotoxic type that reacts directly with
DNA or with micromolecules that then react with DNA.
carcinogenesis
A multistep sequence consisting of initiation, promotion,
progression, and malignant conversion through which a cell
may progress to deregulation of cell growth resulting in
malignant transformation.
carcinoma
A malignant tumor comprised of epithelial cells that infiltrate
surrounding tissues and lead to metastases.
carcinoma-associated antigens
Self antigens whose epitopes have been changed due to
effects produced by certain tumors. Self antigens are
transformed into a molecular structure for which the
host is immunologically intolerant. Examples include the
T antigen, which is an MN blood group precursor molecule
exposed by the action of bacterial enzymes, and the Tn
antigen, which is a consequence of somatic mutation in
hematopoietic stem cells caused by inhibition of galactose
transfer to N-acetyl-d-galactosamine.
carcinomatous neuropathy
Neurological findings in tumor-bearing patients who have
no nervous system metastasis. Sensory carcinomatous neuropathy,
in which patients develop autoantibodies specific
for neurone cytoplasm RNA-protein, is an example of a
carcinomatous neuropathy.
cardiac disease, autoimmune
Rheumatic fever is a classic example of microbial-induced
autoimmune heart disease. The immune response against the
M protein of group A Streptococci crossreacts with cardiac
proteins such as tropomyosin and myosin. The M protein
contains numerous epitopes that participate in these crossreactions.
A second crossreactive protein in the streptococcal
membrane has been purified to a series of four peptides
ranging in molecular weight from 22 to 23 kDa. Patients
with rheumatic fever may develop antibody that binds to the
cytoplasm of cells of the caudate nuclei with specificity for its