Untitled - D Ank Unlimited

spontaneous cancer 666 SS-A/Ro
in the pathogenesis and T cells rather than B cells of OS
chickens are defective.
spontaneous cancer
A malignant neoplasm that arises in a laboratory animal
without experimental intervention.
spontaneous remission
The reversal of progressive growth of a neoplasm with
inadequate or no treatment. Spontaneous remission occurs
only rarely.
sporadic cancer
A malignant neoplasm of humans induced by somatic cell
rather than germ cell transformation.
spot ELISA
An assay that is a variation on standard enzyme-linked
immunosorbent assay (ELISA). It is used primarily for
the detection of immunoglobulin-secreting cells (ISCs) or
cytokine-secreting cells (CSCs), although future applications
may include detection of specific hormone-secreting
cells. As in standard ELISA, the starting point is a plastic
or nitrocellulose vessel coated with antigen or capture
antibody. The ISC or CSC of interest is added and then
removed following sufficient incubation time for the cell to
secrete its immunoglobulin or cytokine. The secreted product
binds locally to the capture protein and is subsequently
detected by enzyme-linked antibody. Finally a substrate
that yields an insoluble product is added, and the resulting
colored precipitate is quantified.
S protein
An 83-kDa serum protein in humans that prevents generation
of the membrane attack complex (MAC) of
complement. The S protein molecule is comprised of one
478-amino acid residue polypeptide chain. Its mechanism of
action is to inhibit insertion of the C5b67 complex into the
membrane of a cell by first linking three of its molecules to
each free C5b67 complex. It also inhibits C9 from polymerizing
on C5b678 complexes. Refer also to vitronectin.
SP thymocyte
Single positive thymocyte that expresses either CD4 + with
a surface phenotype of CD4 + CD8¯ or CD8 + with a surface
phenotype of CD4¯CD8 + .
sprue
Refer to gluten-sensitive enteropathy.
spur
An extension of a precipitation line observed in a twodimensional
double immunodiffusion assay such as the
Ouchterlony test. It represents a reaction of partial identity
between two antigens that cross react with an antibody.
squalene
A substance synthesized when cholesterol is converted to
fat. It is present in selected cosmetics and foods. Squalene
has immunologic adjuvant properties and has been used in
experimental vaccines as an adjuvant to facilitate response
to an immunogen; adjuvants are incorporated into certain
vaccines to improve the response to the vaccine constituents.
Not all vaccines, however, contain adjuvants; some
do not require adjuvants to induce protective immunity in
recipients. Aluminum compounds are common adjuvants in
licensed vaccines. Some vaccines administered to military
personnel during the Gulf War, including anthrax, botulinum
toxoid, hepatitis B, and tetanus–diphtheria vaccines,
contained aluminum compounds as adjuvants. The presence
of antibodies to artificial squalene in the sera of Gulf War
veterans has been interpreted by some investigators to
imply that squalene or its antibodies may have contributed
to these illnesses. The investigators believe that squalene
was used as an adjuvant, a claim that has been denied by
the U.S. Department of Defense. Squalene is not approved
by the FDA for use as an adjuvant in anthrax or any other
vaccine.
SRBCs
Abbreviation for sheep red blood cells.
Src homology 2 (SH-2) domain
A 100-amino acid residue, three-dimensional domain structure
found in numerous signaling proteins that allows specific
noncovalent interactions with other proteins by linking
to phosphotyrosines. A unique binding specificity for each
SH-2 domain is determined by amino acid residues adjacent
to the phosphotyrosine on the target protein. SH-2 domains
serve as important sites of protein interaction during early
signaling events in T and B lymphocytes.
Src homology 3 (SH-3) domain
A 60-amino acid residue, three-dimensional domain structure
found in numerous signaling proteins that facilitates
the binding of proteins to one another. SH-3 domains
bind to proline residues and function in concert with SH-2
domains on the same protein molecules.
S region
The chromosomal segment of the murine major histocompatibility
complex (MHC) containing genes that encode
MHC class III molecules, including complement component
C2, factor B, C4A (Slp), and C4B (Ss). The S locus within
this region contains genes that encode a 200-kDa protein
termed Ss (serum substance) that corresponds to C4 in the
sera of humans. Also within the S region can be found the
gene for Slp (sex limited protein), a protein usually found
only in male mice; the gene for 21-hydroxylase, an enzyme
with no known immune function; and the gene for a serum
β globulin. This term likewise refers to the chromosomal
segment that lies between HLA-B and HLA-D, where the
genes encoding the corresponding human MHC class III
molecules are situated.
SRS-A
Abbreviation for slow-reacting substance of anaphylaxis.
SRV-1
A simian acquired immune deficiency syndrome (AIDS)
virus type D that shows little similarity with human immunodeficiency
1 (HIV-1); however, both contain genes that
resemble one another. This strain was responsible for an
infection among a colony of macaques in California.
SRY
The protein coded for by the sex-determining region of the Y
chromosome, known as the sry gene in humans. It is equivalent
to the testis-determining gene of the Y chromosome.
The corresponding protein in mice is called Sry. The murine
sry gene can cause transgenic female mice to become phenotypic
males when the gene is inserted into them.
SS-A
Anti-RNA antibody that occurs in patients with Sjögren’s syndrome.
The antibody may pass across the placenta in a pregnant
female and be associated with heart block in her infant.
SS-A/Ro
An antigen in the cytoplasm to which 25% of patients with
lupus erythematosus and 40% of patients with Sjögren’s
syndrome synthesize antibodies.