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===Hyaline Degeneration===
 
===Hyaline Degeneration===
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Hyaline degeneration - a descriptive term meaning 'glassy'' and applied to several
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types of degeneration or infiltration. Some are extracellular e.g. protein hyaline casts in the
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renal tubules, while others are intracellular e.g. hyaline degeneration of skeletal muscle. The
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word hyaline is used in pathology when material appears structureless in section and stains
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red with eosin. Hyaline degeneration is really a descriptive term of a variety of
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conditions in which structureless materials are present.
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Instances of 'hyaline' degeneration:
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a. renal intratubular casts from excessive protein passing through glomerulus: When fresh
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urine is examined under the microscope, they may be seen as elongated glassy tubes.
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b. proteinaceous effusions into pulmonary alveoli are known as hyaline membranes: they
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prevent gaseous exchange.
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c. hyaline degeneration of muscle in deficiency of Vit. E/ Selenium.
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21
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Two forms of hyaline change deserve mention on their own. One is fibrinoid degeneration
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and the other is amyloid infiltration.
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====Fibrinoid Degeneration====
 
====Fibrinoid Degeneration====
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Fibrinoid degeneration
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This implies that there is a
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material which is fibrin-like,
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and is essentially a focal death
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of cells in the walls of small
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blood vessels, usually
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arterioles. Parts of the vessel
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wall become replaced by a
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homogenous or granular
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eosin-staining material, which
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has some of the appearance
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and staining properties of
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fibrin. This pinkish-red
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material consists partly of
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degenerated muscle and elastic
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fibres, and partly of an
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increased amount of protein ground substance around the degenerated fibres. Its main
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importance is that it may suggest either a local hypersensitivity reaction or hypertension in
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the blood vessels. When viewed histologically, the fibrinoid degeneration is like a red
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smudge in part of the vessel wall.
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====Amyloidosis====
 
====Amyloidosis====
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Amyloid infiltration - Amyloidosis
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It is the deposition of a proteinaceous
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hyaline substance extracellularly in
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specific tissues. The sites of
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deposition vary with the species. The
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kidney is a common site. Here the
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amyloid is deposited under the
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capillary endothelium and
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progressively increases in volume.
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Various categories of amyloid exist.
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It is essentially an abnormal protein
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produced in the body. In most natural
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cases in domestic animals, it is
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produced in response to sustained
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antigenic stimulation in the body caused by a chronic suppurative process such as a foot
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abscess, mastitis, etc.
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It is a relatively inert substance and when it accumulates, it is not easily removed.
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===Glycogen Infiltration===
 
===Glycogen Infiltration===
 
===Cellular Inclusions===
 
===Cellular Inclusions===
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