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Whipple’s disease 750 Winn assay
Whipple’s disease
A disorder characterized immunologically by massive infiltration
of the lamina propria with periodic acid Schiff stain
(PAS)-positive macrophages. Secondary T cell abnormalities
are observed. This is a rare infectious disease produced
by one or more microorganisms that remain unidentified.
Diagnosis is established by intestinal biopsy, showing microorganisms
and numerous macrophages containing microbial
cell wall debris in their cytoplasm. The cellular infiltration
is associated with “clubbed” villi, lymphatic obstruction,
malabsorption, and protein-losing enteropathy. Loss of
lymphocytes into the gastrointestinal tract as a result of lymphatic
obstruction may be associated with the development
of lymphopenia and secondary T cell immune deficiency.
white graft rejection
Accelerated rejection of a second skin graft performed 7 to
12 days after rejection of the first. It is characterized by lack
of vascularization of the graft and its conversion to a white
eschar. The characteristic changes are seen by day 5 after
the second procedure. The transplanted tissue is rendered
white because of hyperacute rejection, such as in the case
of a skin or kidney allograft. Preformed antibodies occlude
arteries following surgical anastomosis, producing infarction
of the tissue graft.
Periarteriolar
lymphoid sheath
(T Cell Zone)
Arteriole
Spleen morphology
(White Pulp)
White pulp.
Lymphoid follicle
(B Cell Zone)
Vascular sinusoid
white pulp
The periarteriolar lymphatic sheaths encircled by small lymphocytes
that are mainly T cells surrounding germinal centers
composed of B lymphocytes and B lymphoblasts in normal
splenic tissue. Following interaction of B cells in the germinal
centers with antigen in the blood, a primary immune response
is generated within 24 hours, revealing immunoblastic proliferation
and enlargement of germinal centers.
white pulp diseases
Lymphoproliferative diseases that express major anatomical
changes in the splenic white pulp. They include histiocytic
lymphoma, lymphocytic leukemia, and Hodgkin disease.
whooping cough vaccine
Refer to pertussis vaccine.
Widal reaction
Bacterial agglutination test used to diagnose enteric infections
caused by Salmonella. Doubling dilutions of patient
serum are combined with a suspension of microorganisms
known to cause enteric fever such as S. typhi, S. paratyphi
B, and S. paratyphi A and C. The test microorganisms
should be motile and smooth and in the specific phase.
Formalin-treated suspensions are used to assay H agglutinins,
and alcohol-treated suspensions assay O agglutinin.
The Widal test is positive after the 10th day of the disease.
Results may be false-positive if an individual previously
received a TAB vaccine. Thus, it is important to repeat the
test and observe a rising titer rather than merely observe a
single positive test. Widal originally described the test to
diagnose S. paratyphi B infection.
Alexander Wiener.
Wiener, Alexander
Co-discoverer with Landsteiner of the Rh blood group system.
wild mouse
A mouse that is free in the environment and has not been
raised under laboratory conditions.
window
(1) The period between exposure to a microorganism and
the appearance of serologically detectable antibody. It is
observed in hepatitis B and in human immunodeficiency virus
1 (HIV-1) infections. In hepatitis B, a “core window” occurs
in active but unidentified infection. The hepatitis B surface
antigen (HBsAg) can no longer be detected, and the antibody
against hepatitis B surface antigen (anti-HB s) has not reached
sufficiently high levels to be detected. (2) The period between
the first infection with HIV-1 and synthesis of anti-p24 and
anti-p41 antibodies in amounts measurable by the enzymelinked
immunosorbent assay (ELISA). Use of the polymerase
chain reaction (PCR) to demonstrate the p24 antigen can be
useful to indicate infection during the window. The window
period in HIV-1 infection may be 3 to 9 months and may
reach 36 months. Blood donated for transfusion in the United
States is assayed for anti-HIV-1 p24 antibody; thus, these
units of blood may be in the HIV-1 infection window.
Winn assay
A method to determine the ability of lymphoid cells
to inhibit the growth of transplantable tumors in vivo.
Following incubation of lymphoid cells and tumor cells in
vitro, the mixture is injected into the skin of X-irradiated