Untitled - D Ank Unlimited

OKT4 540 oncofetal antigens
OKT4
Refer to CD4.
OKT8
Refer to CD8.
old tuberculin (OT)
A broth culture, heat-concentrated filtrate of medium in
which Mycobacterium tuberculosis microorganisms are
grown. Robert Koch developed it for use in tuberculin skin
tests nearly a century ago.
+
PT 1
PT 2
PT 3
Cerebrospinal Fluid Electrophoresis
= Oligoclonal IgG bands
Oligoclonal bands.
(gamma region)
oligoclonal bands
When the cerebrospinal fluids of some multiple sclerosis
patients are electrophoresed in agarose gel, immunoglobulins
with restricted electrophoretic mobility may appear as
multiple distinct bands in the γ region. Although nonspecific,
90 to 95% of multiple sclerosis patients show this
banding. The bands may appear in selected other central
nervous system diseases such as herpetic encephalitis,
bacterial or viral meningitis, carcinomatosis, toxoplasmosis,
neurosyphilis, progressive multifocal leukoencephalopathy,
and subacute sclerosing panencephalitis, and may appear
briefly during the course of Guillain-Barré disease, lupus
erythematosus vasculitis, spinal cord compression, diabetes,
and amyotrophic lateral sclerosis.
oligoclonal response
An immune response characterized by only a few separate
clones of immunocompetent cells responding to yield a
small number of immunoglobulin bands in agarose gel
electrophoresis.
oligomorphic
Genes that possess only a relatively small number of different
alleles in the population.
oligosaccharide determinant
An epitope or antigenic determinant of a polysaccharide
hapten that consists of relatively few (two to seven) pentoses,
hexoses, or heptoses united by glycoside linkages.
–
Omenn’s syndrome
A severe immunodeficiency characterized by the development
soon after birth of a generalized erythroderma
desquamation, failure to thrive, protracted diarrhea,
hepatosplenomegaly, hypereosinophilia, and markedly
elevated serum immunoglobulin E (IgE) levels. It has been
observed in association with neonatal minimal-change
nephritic syndrome. Circulating and tissue-infiltrating
activated T lymphocytes that do not respond normally to
mitogens or antigen in vitro are increased. These T cells
are both oligoclonal and polyclonal. Circulating B cells
are not found, and the only hypogammaglobulinemia is
for IgE. Superficial lymph node architecture is grossly
abnormal due to a proliferation of interdigitating, S-100,
protein-positive, nonphagocytic reticulum cells and a
depletion of B lymphocytes. This is believed to be a Th2mediated
condition, even though the fundamental defect
has not been discovered. This form of severe combined
immunodeficiency is induced by amino acid substitution
mutations in the RAG genes that significantly diminish
the activity of the corresponding proteins to 1 to 25% of
normal. The condition is fatal in the first 5 months of life
unless corrected by bone marrow transplantation following
chemoablation.
Onchocerca volvulus immunity
This filarial parasite that can induce dermal and ocular
complications contains antigens that induce antigen-specific
immunoglobulin G (IgG), IgM, IgE, and IgA antibodies in
addition to polyclonal stimulation. Humoral immunity develops
early in chimpanzees, but the exact role of antibodies
in protection remains to be determined. Antibodies against
microfilariae facilitate adherence of granulocytes in vitro,
and eosinophils and neutrophils mediate antibody-dependent
killing. Massive eosinophil degranulation may lead to tissue
injury. Infected subjects develop elevated IgE that may
worsen ocular lesions by contributing to acute inflammation.
Much of the IgE antibody is O. volvulus antigen-specific.
Immune complexes may also contribute to acute inflammation.
Cell-mediated immunity is downregulated to antigens
that are specific and nonspecific for the infectious agent.
Onchocerciasis is marked by predominant Th2 cytokine
responses in subjects with ocular pathologies, whereas a Th1
response is associated with immunity. Thus, the host immune
response is significant in both pathology and protection in
onchocerciasis. The HLA-D allele influences the pathogenesis
of O. volvulus infection. Ocular pathology is the most
serious result, affecting both anterior and posterior segments
of the eye. Protection against onchocerciasis has been
directed to vector control, but development of a protective
vaccine would be a better solution. Larval antigens are the
best targets for a prophylactic vaccine.
oncofetal antigens
Markers or epitopes present in fetal tissues during development
and not present or found only in minute quantities in
adult tissues. These cell-coded antigens may reappear in
certain neoplasms of adults due to derepression of the gene
responsible for their formation. Examples include carcinoembryonic
antigen (CEA) found in the liver, intestine,
and pancreas of the fetus and also in both malignant and
benign gastrointestinal conditions. It is still useful to detect
the recurrence of adenocarcinoma of the colon based on
demonstration of CEA in the patient’s serum; α-fetoprotein