Basic Principles of Cell Structure and Function
PASD (periodic acid-Schiff with diastase digestion),
Alpha 1-antitrypsin deF ciency is an autosomal recessive disorder characterized
by low serum concentrations of the enzyme
, which inhibits
or inactivates proteases and elastases. Alpha 1-antitrypsin deF
ciency may cause
neonatal hepatitis with later cirrhosis and pulmonary panacinar emphysema.
A liver biopsy in a patient with alpha 1-antitrypsin deF ciency shows accu-
mulated alpha 1-antitrypsin as hyaline globules in this PAS stain. The globules
remain after the tissue has been treated with diastase (diastase resistant).
is an abnormal protein caused by many pathological conditions, the most
common of which include
, caused by light chains secreted by plasma
cells in plasma cell myeloma or monoclonal B-cell neoplasms;
in chronic inﬂ ammatory conditions; and
in Alzheimer disease. Many
other types of amyloids exist.
A lymph node containing AL amyloid in a patient with small lymphocytic
lymphoma is shown. In H&E-stained preparations, amyloid is amorphous and
eosinophilic. Amyloid stained with Congo red shows a characteristic green bire-
fringence when viewed with polarized light.
, is the abnormal intracellular accumulation of lipid.
Although it can occur in many organs, it is most commonly seen in the liver because
of a variety of causes including alcohol abuse, hepatitis C, genetic predisposition,
medications, toxins, and diabetes mellitus.
This liver biopsy shows marked steatosis with intracellular lipid vacuoles.
Immunohistochemistry for alpha-synuclein,
is an intracytoplasmic oval with a halo, formed in neuromelanin-
containing neurons in patients with idiopathic Parkinson disease.
In this immunoperoxidase preparation, brown pigment indicates the pres-
ence of alpha synuclein (
), the main protein in the inclusion.
In patients with Alzheimer disease, microtubule-associated protein tau and
phosphorylated neuroF laments form
neurof brillary tangles
This silver-stained slide shows a twisted, black helix (
) in the cytoplasm
of a neuron from a patient with Alzheimer disease.