Vacuole, glycogen

Site no. Vacuolation Glycogen content Fibrillar structures CYPIA ... 

In childhood and adult-onset forms of AM, more moderate glycogen storage and vacuolation of muscle are seen and not all fibers are affected. Although cardiomegaly is not apparent in childhood AMD, glycogen storage is detectable histologically in heart muscle. 

Glycogenosis type IV (branching enzyme deficiency) results in the formation of a variant of glycogen, characterized by abnormally long inner and outer glucosyl chains and fewer branch points than normal. The abnormal variant is stored in sufficient amounts to cause some vacuolation. The clinical manifestations of this... 

Muscle biopsy shows vacuolar myopathy of very severe degree affecting all fibers in Pompe s disease but of varying degree and distribution in childhood and adult AMD. In adult AMD, biopsy specimens from unaffected muscles may appear normal by light microscopy. The vacuoles contain PAS-positive material, a marker for glycogen. Electron microscopy shows abundant glycogen, both within membranous sacs, presumably lysosomes, and free in the cytoplasm. 

Muscle biopsy shows severe vacuolar myopathy with glycogen storage. On electron microscopy, the vacuoles correspond to pools of glycogen free in the cytoplasm. 

Previous analysis showed that CYPIA immunoreactivity in flounder could be induced in laboratory experiments by exposure to substances such as TCDD and PCB-126 (Grinwis et al, 2000). The present study demonstrated that this induction of CYPIA immunoreactivity can be found in liver from flounder. The other histopathological biomarkers in the present study proved either difficult to interpret (vacuolation) or relatively insensitive to contaminants at the locations in this study (glycogen content, fibrillar structures). 

Excessive glycogen concentrations found in abnormal vacuoles in the cytosol... 

Identification When examined under a microscope, a sample exhibits numerous irregular masses and isolated yeast cells—the latter ovate, elliptical, spheroidal, or elliptic-elongate in shape, some with one or more attached buds—up to 12 pun in length and up to 7.5 xm in width. Each has a wall of cellulose surrounding a protoplast containing refractile glycogen vacuoles and oil globules. 

Fig. 31.1 Glycogenated nuclei (so-called glycogen vacuolations of the nuclei) in diabetes mellitus. Insert nucleus strongly laden with glycogen ( ) (PAS) (s. pp 396, 526, 589, 596, 611, 620)...

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