Untitled - D Ank Unlimited

Landsteiner’s rule (historical) 440 Langerhans cells
artificial haptens to investigate antibody specificity and
received the Nobel Prize in Medicine or Physiology in 1930
for discovery of the human blood groups. He was born in
Vienna in 1868. He attended the University of Vienna and
graduated in 1891 as a medical doctor. He maintained a
strong interest in chemistry and took special instruction
under Emil Fischer and Eugen von Bamberger. In 1896, he
became an assistant at the Institute of Hygiene directed by
Max von Grüber and was introduced to immunology and
serology that occupied his research interests for the remainder
of his career. He also conducted research in pathology.
He coauthored nine papers with Donath, including a report
on paroxysmal hemoglobinuria. Landsteiner was appointed
a research assistant at the Vienna Pathological Institute in
1898. He remained there until 1908 when he became chief
of pathology at the Royal Imperial Wilhelminen Hospital in
Vienna and adjunct professor on the Medical Faculty of the
University of Vienna. After World War I, Austria was chaotic
and experienced inflation and fuel and food shortages.
Landsteiner left for the Hague in The Netherlands in 1919,
where he accepted a position at the Catholic Hospital. He
was lured to the Rockefeller Institute for Medical Research in
New York in 1923 at the invitation of its director, Dr. Simon
Flexner. He became an American citizen in 1929 and died
in New York on 26 June 1943. He discovered the human
blood groups in 1900 when he found that the sera of some
individuals could cause the agglutination of red cells from
others. This led him to characterize red blood cells according
to their antigens, leading subsequently to a description of the
ABO blood groups. The development of citrates as anticoagulants
in 1914 by Richard Lewisohn and Landsteiner’s blood
grouping system led to the widespread use of blood transfusion.
In 1927, Landsteiner and Phillip Levine discovered the
M and N blood group antigens that are not of significance in
transfusion since human blood serum does not contain isoagglutinins
(antibodies) against them, differentiating MN from
the ABO groups. In 1940 Landsteiner, Levine, and Weiner
discovered the Rh blood group system when they found that
antibodies raised in rabbits and guinea pigs immunized with
blood from a rhesus monkey agglutinated the red blood cells
of many humans (termed Rh positive). Those not possessing
this blood factor were termed Rh negative. The Rh factor was
shown to be important in hemolytic disease of the newborn.
Landsteiner investigated poliomyelitis between 1908 and
1922. He discovered that a rhesus monkey became paralyzed
following the injection of brain and spinal cord from a polio
victim. After finding no bacteria in the monkey’s nervous
system, Landsteiner concluded that a virus was the causative
agent. He perfected a technique to diagnose poliomyelitis.
He discovered that an extract of ox hearts could replace the
antigen derived from livers of babies with congenital syphilis
for use in the Wassermann test for syphilis. Landsteiner continued
his serology and immunology work at the Rockefeller
Institute. He examined the effects of position on attached
radicals. He discovered that immunochemical specificity
was altered by the ortho, meta, or para position on aromatic
rings of stereoisomers; position was more important than the
nature of the radical. Landsteiner further showed that partial
antigens (called haptens) were unable to elicit antibody
formation, but could react with those formed in response to
a complete antigen comprising a hapten bound to a carrier
molecule. He demonstrated carrier- and hapten-specific
antibodies. His extensive investigations on immunochemical
specificity were summarized in his book titled Die
Specifizität der serologischen Reactionen published in
1933. The English translation was published in 1936, and a
revised edition titled The Specificity of Serological Reactions
appeared after his death in 1945. Landsteiner found that
haptens could combine with pre-existing antibodies to produce
allergic desensitization. His work laid a foundation for
much of modern immunology, including the construction of
synthetic vaccines.
Landsteiner’s rule (historical)
In 1900, Karl Landsteiner discovered that human red blood
cells could be separated into four groups based on their
antigenic characteristics. The groups were designated O, A,
B, and AB. He found naturally occurring isohemagglutinins
in the sera of individuals specific for the (ABO) blood group
antigen which they did not possess (i.e., anti-A and anti-B
isohemagglutinin in group O subjects, anti-B in group A
individuals, anti-A in group B persons, and neither anti-A
nor anti-B in individuals of group AB). This principle
became known as Landsteiner’s rule.
lane
The path of migration of a molecule of interest from a well
or point of application in gel electrophoresis. A substance is
propelled within the confines of this path or corridor by an
electric current that induces migration and separation of the
molecules into bands according to size.
Langerhans cell.
Langerhans cells
Phagocytic- and dendritic-appearing accessory cells interspersed
between cells of the upper layer of the epidermis.
They function as antigen-presenting cells and produce
cytokines that attract lymphocytes to the skin. They can be
visualized by gold chloride impregnation of unfixed sections
and show dendritic processes but no intercellular bridges. By
electron microscopy, they lack tonofibrils or desmosomes,
have indented nuclei, and contain tennis racket-shaped
Birbeck granules (relatively small, round to rectangular vacuoles
that measure 10 nm). Following their formation from
stem cells in the bone marrow, Langerhans cells migrate to
the epidermis and then to the lymph nodes, where they are
described as dendritic cells based upon their thin cytoplasmic
processes that course between adjacent cells. Langerhans