Search results for "Ultrastructural Pathology"
showing 8 items of 8 documents
Ultrastructural Pathology of Anaplastic and Grade II Ependymomas reveals Distinctive Ciliary Structures - Electron Microscopy Redux
2015
Ependymoma tumors likely derive from the ependymal cells lining the CNS ventricular system. In grade II ependymomas, tumor cells resemble typical ependymocytes, while anaplastic ependymomas are poorly differentiated. We studied three grade II and one anaplastic ependymoma, focusing on the ciliary structures. To unambiguously characterize the ultrastructure and number of cilia, we performed electron microscopy serial section analysis of individual cells. Differentiated ependymomas contained large basal bodies and up to three cilia, and lacked centrioles. Anaplastic ependymoma cells showed instead two perpendicularly oriented centrioles and lacked cilia or basal bodies. These findings could c…
Extracerebral biopsies in neurodegenerative diseases of childhood
1999
Abstract Among the numerous neurodegenerative diseases in children few may allow morphological diagnosis by extracerebral biopsy. These encompass neurometabolic conditions, foremost lysosomal disorders, but also peroxisomal and mitochondrial diseases marked by disease- or group-specific organelles. Largely, these neurometabolic conditions can also be diagnosed by biochemical and increasingly by molecular genetic techniques. However, there are a few neurodegenerative diseases which do not allow either biochemical or molecular genetic diagnosis and, thus, rely on biopsy of extracerebral tissues, so-called ‘essential’ biopsies to achieve a diagnosis during the patient's life. Among these few d…
Ultrastructural pathology of dermal axons and Schwann cells in lysosomal diseases
1988
Skin tissue specimens, obtained from 60 patients afflicted with a diverse range of lysosomal disorders revealed two groups of lesions within dermal axons, largely unmyelinated ones, particularly within axonal terminals: (1) non-specific mitochondria and dense bodies often enlarging the axonal terminal; and (2) disease-specific lysosomal residual bodies, the latter less frequent depending on the incidence and type of lysosomal disorders, i.e., largely only seen in GM2-gangliosidosis due to hexosaminidase A deficiency and mucolipidosis IV, while the spectrum of lysosomal residual bodies in Schwann cells appeared more variegated, especially due to the occurrence of vacuolar lysosomal residual …
Ultrastructural Pathology of Eccrine Sweat Gland Epithelial Cells in Globoid Cell Leukodystrophy
1993
Three of four children were recognized by deficient β-galactocerebrosidase activities as having globoid cell leukodystrophy inclusions in sweat gland epithelial cells, similar in ultrastructure to those seen in Schwann cells. This observation in globoid cell leukodystrophy emphasizes the need to include sweat gland epithelial cells in examinations of skin in globoid cell leukodystrophy, as well as in any neurometabolic disorder. ( J Child Neurol 1993;8:171-174).
Ultrastructural pathology in emetine-induced myopathy
1988
Progressive myopathy developed in two women who consumed ipecac syrup containing emetine hydrochloride to induce vomiting as part of their anorexia nervosa. Muscle biopsy specimens were characterized by severe disruption of the sarcomeres. The ultrastructural spectrum extended from "Z-band streaming" to the formation of cytoplasmic bodies and also comprised abnormalities of the sarcotubular system, thus suggesting that muscle weakness may be related to both sarcomeric and sarcotubular lesions in this self-inflicted myopathy. It is tempting to suggest that muscle weakness may be correlated with or based on the pathology in sarcomeres and the sarcotubular system. As the myopathy is clinically…
Practical application of electron microscopy to neuromuscular diseases.
2013
Concerning individual neuromuscular conditions, electron microscopy may be considered “essential,” “helpful,” or “wasteful.” “Essential” electron microscopy should provide a clear diagnosis, because of the disease specificity of the ultrastructural findings, in particular as to inclusions within muscle fibers, such as cylindrical spirals and reducing bodies. Electron microscopy may be “helpful” in detecting ultrastructural features preceding typical light microscopic findings, for instance, undulating tubules in endothelial cells. Congenital, metabolic, and inflammatory myopathies may often be more easily and more reliably diagnosed by means of the electron microscope. Diagnostically “waste…
Late-Onset Globoid Cell Leukodystrophy: Unusual Ultrastructural Pathology and Subtotal β-Galactocerebrosidase Deficiency
1990
An 11-year-old girl was found to have severely reduced β-galactocerebrosidase activity as evidence of late-onset globoid cell leukodystrophy, while her mother had almost normal enzyme activity in circulating white blood cells. Clinically, the patient showed a remitting course marked by seizures, ataxia, white-matter disease on computed tomographic scan, and reduced conduction velocities of peripheral nerves. Symptoms improved somewhat around the age of 10 years. Two sural nerve biopsies, performed 6 years apart, disclosed a demyelinating neuropathy. By electron microscopy, membrane-bound vacuolar lysosomes in Schwann cells of myelinated axons, unlike the typical needlelike inclusions seen …
Liver pathology in transient neonatal hyperammonemia.
1983
Ultrastructural investigations have been performed on two cases of transient neonatal hyperammonaemia (TNH). This newly recognized metabolic disorder is chiefly characterized by severe hyperammonaemia in the postnatal period, a comatous state, absence of abnormal organic aciduria, normal activity of urea cycle enzymes and, usually, complete recovery. The aetiology is presently unknown. Electron microscopy uncovered rather congruent alterations of hepatocyte structure, with a wide spectrum of mitochondrial lesions, an increase of autophagous bodies with organelle remnants, and changes in the excretory apparatus. Thus, in contrast to some of the hereditary disorders of the urea cycle, no spec…