Untitled - D Ank Unlimited

skin-reactive factor (SRF) 658 slow viruses
Lagerhans
cell
T cell
Fibroblast
Lymphatic
vessel
Macrophage
cells, often with restricted antigen receptors. In mice, they
are mostly γδ T cells. Skin lymphocytes and macrophages
are mostly in the dermis. The T cells are of CD4 + and CD8 +
phenotypes and often perivascular.
skin-reactive factor (SRF)
A lymphokine that induces vasodilation and increased
vascular permeability when injected into the skin.
skin-sensitizing antibody
An antibody, usually of the immunoglobulin E (IgE)
class, that binds to the Fc receptors of mast cells in the
skin, thereby conditioning the area for a type I immediate
hypersensitivity reaction following cross linking of the IgE
Fab regions by a specific allergen (antigen). In guinea pig
skin, human IgG 1 antibodies may be used to induce passive
cutaneous anaphylaxis.
skin-specific histocompatibility antigen
A murine skin minor histocompatibility antigen termed Sk
that can elicit rejection of skin but not other tissues following
transplantation from one parent into the other parent that has
been irradiated and rendered a chimera by previous injection
of F 1 spleen cells. The two parents are from different
inbred strains of mice. The rate of rejection is relatively slow.
Immunologic tolerance of F 1 murine spleen cells to the skin
epitope of the parent in which they are not in residence is
abrogated following residence in the opposite parent.
skin test
Any of several assays in which a test substance is injected
into the skin or applied to it to determine host response.
Skin tests have long been used to determine hypersensitivity
or immunity to a particular antigen or product of a
microorganism. Examples include the tuberculin test, the
Schick test, the Dick test, the patch test, the scratch test, etc.
skin window
A method for observing sequential changes in cells during
the development of acute inflammation. Following
superficial abrasion of an area of skin, sterile cover slips are
applied, removed at specified intervals thereafter, stained,
and observed microscopically for the types of cells present.
The first cells to appear are polymorphonuclear neutrophils
that comprise most of the cell population within 3
to 4 hours of the induced injury. By contrast, a cover slip
removed after 12 hours reveals mononuclear cells such as
lymphocytes, plasma cells, and monocytes. Removal after
24 hours reveals mostly monocytes and macrophages. Also
termed a Rebuck window, named for the researcher who
perfected the method.
Mast cell
Cutaneous immune system and its cellular components.
Epidermis
Dermis
skin window of Rebuck
Refer to skin window.
SLE
Abbreviation for systemic lupus erythematosus.
slide agglutination test
The aggregation of particulate antigen using red blood
cells, microorganisms, or latex particles coated with antigen
within 30 seconds following contact with specific antibody.
The reactants are usually mixed by rocking the slide back
and forth, and agglutination is observed macroscopically
and microscopically. The test has been widely used for
screening but is unable to distinguish reactions produced by
cross reacting antibodies that can be ruled out in a tube test
that allows dilution of the antiserum.
slide flocculation test
Refer to slide agglutination test.
slot blot analysis
A quick technique to detect gene amplification by determining
the DNA content of a solution by electrophoresis. The
technique is similar to dot blot, except that a slot instead of
a punched-out hole is cut in the agar.
slow reacting substance of anaphylaxis (SRS-A)
A 400-kDa acidic lipoprotein derived from arachidonic
acid that induces the slow contraction of bronchial smooth
muscles and is produced following exposure to certain antigens.
It is composed of leukotrienes LTC 4, LTD 4, and
LTE 4 that produce the effects observed in anaphylactic reactions.
SRS-A is released in vitro in effluents from synthesized
lung tissues of guinea pigs, rabbits, and rats perfused
with antigen. It has also been demonstrated in human
lung tissue and nasal polyps. It contracts smooth muscles
of guinea pig ileum. In vitro, it also increases vascular
permeability upon intracutaneous injection and decreases
pulmonary compliance by a mechanism independent of
vagal reflexes. It enhances some smooth muscle effects of
histamine. The sources of SRS-A are mast cells and certain
other cells; it is found in immediate (type I) hypersensitivity
reactions. SRS-A is not stored in a preformed state and
is sequentially synthesized and released. The effects have a
latent period before becoming manifest. Antihistamines do
not neutralize the effects of SRS-A.
slow viruses
Agents that induce infectious encephalitis following a
lengthy latency. Slow viruses consist of conventional
viruses and prions that are composed of subverted cell
proteins. Among the conventional viruses group is measles,