Intraventricular Neurocytoma with Prominent Myelin Figures

1999 ◽  
Vol 23 (5) ◽  
pp. 311-317 ◽  
Author(s):  
Sung-Hye Park, Nora Ostrzega, Mari-
1997 ◽  
Vol 36 (4) ◽  
pp. 567
Author(s):  
Ik Soo Kim ◽  
Myung Soon Kim ◽  
Chang Man Lee

Blood ◽  
1975 ◽  
Vol 46 (5) ◽  
pp. 723-734 ◽  
Author(s):  
RT Parmley ◽  
M Ogawa ◽  
CP Jr Darby ◽  
SS Spicer

Abstract A child with congenital neutropenia was studied using bone marrow culture and ultrastructural and cytochemical techniques. The patient's marrow cells formed a large number of granulocytic colonies of normal size in culture, and her peripheral blood leukocytes produced adequate colony-stimulating factor. No serum inhibitors were identified. The patient's promyelocytes from direct marrow and culture appeared normal in ultrastructure, and primary granules, contained peroxidase and acid phosphatase activity. Myelocytes and rare segmented neutrophils from direct marrow specimens demonstrated atypical notched nuclei, myelin figures in Golgi lamellae and primary (azurophilic) granules, and no identifiable secondary (specific) granules. These data indicate an intrinsic neutrophil defect which allows normal proliferation of precursor cells, but results in abnormal granulogenesis and apparent inability to form secondary granules.


1989 ◽  
Vol 985 (1) ◽  
pp. 101-105 ◽  
Author(s):  
I. Sakurai ◽  
T. Suzuki ◽  
S. Sakurai

2017 ◽  
Vol 124 (1) ◽  
Author(s):  
Jung-Ren Huang ◽  
Yu-Che Cheng ◽  
Hung Ji Huang ◽  
Hai-Pang Chiang

1962 ◽  
Vol 14 (3) ◽  
pp. 401-420 ◽  
Author(s):  
I. K. Buckley

Unfixed, compressed acinar cells of rat pancreas, isolated by mechanical and enzymatic means, were examined by phase microscopy and photomicrographed using 35 mm film and electronic flash illumination. Similarly, observations were made on Walker carcinoma cells; in addition, these cells were treated with solutions containing either phosphatidase A or enzyme inhibitors. Acinar cells contained, besides nuclei, perinuclear droplets and secretion granules, various membranous and vacuolar structures. The basal cytoplasm showed parallel dark lines interpreted as endoplasmic reticulum. In some cells, fragmentation of the reticulum was followed by the direct incorporation of fragments into simple myelin figures. In other cells it appeared that phase-lucent linear structures and vacuoles were derived by dilatation of cisternae of the endoplasmic reticulum. Perinuclear fluid collections arose either by dilation of the perinuclear cisternae of the endoplasmic reticulum or by fluid dilatation of the nuclear envelope. Phosphatidase A disrupted early vacuoles of Walker carcinoma cells. From this and the direct involvement of elements of the endoplasmic reticulum in myelin figures, it was concluded that the membranes limiting the endoplasmic reticulum incorporate phosphatides in continuous layers. While many severely injured cells formed large vacuoles, others developed concentrically laminated myelin figures; it was concluded that both types of structure derived from phosphatides liberated intracellularly, the vacuoles by vesicular myelin figure formation.


2012 ◽  
Vol 62 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Maria Izabel Camargo-Mathias ◽  
Odair Correa Bueno ◽  
Alexsandro Santana Vieira

AbstractThe metapleural gland is considered a synapomorphy of ants, and is characterized as a paired structure located at the two postlateral ends of the thorax and secretes substances capable of inhibiting and controlling fungi and bacteria in the fungus garden and inside the nest. This study was aimed at investigating if and which are the ultrastructural differences in the metapleural gland cells of workers (three castes) of Atta laevigata using transmission electron microscopy (TEM). This study revealed the presence of Golgi regions, rough endoplasmic reticulum (lamellar and vesicular shapes), smooth endoplasmic reticulum, mitochondria (elongated, round-shaped), vacuoles, secretion granules with different electron densities, and myelin figures in the cytoplasm of secretory cells, indicating that this gland produces substances composed of proteins, lipids, and polysaccharides (glycogen in major workers). Lipid droplets and secretion granules were found very near to the microvilli, especially in minor workers. The intracellular portion of canaliculi exhibited invaginations that increased the surface area and modified the secretion produced by the secretory cells. In the three castes examined, the gland exhibited a reservoir preceded by a collecting chamber, both lined by a simple squamous epithelium with a cuticular intima. Workers of the three castes of A. laevigata might be involved in the production of secretion mainly composed of proteins with antibiotic properties and, minor workers, may be responsible for producing a wider variety of secretions compared to median and major workers in the colony.


Author(s):  
I. Sakurai ◽  
T. Suzuki ◽  
S. Sakurait

1976 ◽  
Vol 144 (4) ◽  
pp. 906-919 ◽  
Author(s):  
B A Nichols

Normal rabbit alveolar macrophages are engorged with large, dense inclusions which contain whorls of myelin figures, suggesting an exogenous source of polar lipids in their diet. One contributory source of such lipids is surfactant, since macrophages were seen ingesting tubular myelin and vacuoles containing remnants of it were found in the cytoplasm. Thus, as indicated previously in kinetic studies, it appears that alveolar macrophages participate in the turnover of surfactant. However, the relative importance of the macrophage in comparison to other pathways of surfactant removal remains to be determined. It is also noteworthy that although tubular myelin and myelin figures were abundant in the fixative used to wash out the lungs, bacteria were not found in it or in the macrophages. Thus, removal of obsolete surfactant may prove to be one of the mojor endocytic functions of alveolar macrophages.


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