Untitled - D Ank Unlimited

Dameshek, William (1900–1969) 216 dark zone
of the eyes in patients with sympathetic ophthalmia and in
some other diseases.
Dameshek, William (1900–1969)
Noted Russian-American hematologist who was among
the first to understand autoimmune hemolytic anemias. He
spent many years as editor-in-chief of Blood.
dander antigen
A combination of debris, such as desquamated epithelial
cells, microorganisms, hair, and other materials trapped in
perspiration and sebum, constantly deleted from the skin.
Dander antigens may induce immediate, immunoglobulin
E (IgE)-mediated, type I hypersensitivity reactions in
atopic individuals.
HBsAg particles
William Dameshek.
Dane particle
DANE particle.
HBsAg
DANE particle
A 42-nm structure identified by electron microscopy in
hepatitis B patients in the acute infective stage. The DANE
particle has a 27-nm-diameter icosahedral core that contains
DNA polymerase.
danger signals
Molecules from stressed or dying cells or pathogens that
unite with pattern recognition molecules of innate response
cells leading to inflammation. Exposure of immature dendritic
cells to danger signals leads to their maturation and
upregulation of costimulatory molecules, which permits
them to activate rather than tolerize T cells. Bacterial
CpG DNA, ds and ss viral RNA, inflammatory cytokines
and chemokines, internal ROI, products of complement
activation, and heat shock proteins are examples of danger
signals.
danger theory
Refer to Matzinger danger theory.
Danysz, Jan (1860–1928)
Polish investigator who worked at the Institut Pasteur in
Paris. The Danysz neutralization phenomenon was named
for him. His wide-ranging interests included viruses that
are pathogenic specifically for rodents. He subsequently
investigated chemotherapeutic agents.
Danysz phenomenon (Danysz effect)
The addition of toxin to a homologous antitoxin in several
fractions with appropriate time intervals between them,
resulting in a greater toxicity of the mixture than would
occur if the entire sample of toxin was added at once. A
greater amount of antitoxin is required for neutralization if
the toxin is added in divided doses than if all toxin is added
at one time; conversely, less toxin is required to neutralize
the given quantity of antitoxin if all toxin is added at one
time instead of in divided doses at intervals. This form of
reaction has been called the Danysz phenomenon or Danysz
effect. Neutralization in the above instances is tested by
injection of the toxin–antitoxin mixture into experimental
animals. This phenomenon is attributed to the combination
of toxin and antitoxin in multiple proportions. The addition
of one fraction of toxin to excess antitoxin leads to maximal
binding of antitoxin by toxin molecules. When a second
fraction of toxin is added, insufficient antitoxin is available
to bring about neutralization; therefore, the mixture is toxic
due to uncombined excess toxin. Equilibrium is reached
after an appropriate time interval. The interaction between
toxin and antitoxin is considered to occur in two steps: (1)
rapid combination of toxin and antitoxin, and (2) slower
aggregation of the molecules.
dapsone
Diaminodiphenyl sulfone, a sulfa drug used in the treatment
of leprosy. It has also shown efficacy for prophylaxis of
malaria and for therapy of dermatitis herpetiformis.
DARC
Duffy antigen/chemokine receptor. It is a member of the G
protein-coupled receptor family, the chemokine receptor
branch of the rhodopsin family. It is expressed in erythroid
cells in bone marrow. Ligands include the human malarial
parasite Plasmodium vivax. β chemokine ligands include
RANTES; MCP-1 and α chemokine ligands, including
IL-8; and MGSA/GRO. DARC is also expressed in endothelial
cells lining postcapillary venules and splenic sinusoids
in individuals who are Duffy-negative. The receptor is also
found in adult spleen, kidney, and brain, and fetal liver
and is expressed in K562 and HEL cell lines. Also called
erythrocyte chemokine receptor (erythrocyte CKR), RBC
chemokine receptor, gpFy, and gpD.
dark zone
That part of a germinal center in secondary lymphoid tissue
in which centroblasts undergo rapid division. Site where
somatic hypermutation takes place.