Search results for "granules"
showing 10 items of 45 documents
Ultrastructural studies of the retina in infantile neuronal ceroid-lipofuscinosis.
1988
A 9-year-old boy who had died of infantile neuronal ceroid-lipofuscinosis had experienced retina-derived visual failure. Ophthalmologically and morphologically, his retina was severely atrophic and scarred by a dense fibrillary gliosis while photoreceptor cells had completely disappeared, cells of the bipolar layer had decreased in number and had become atrophic beyond cytologic recognition. Retinal pigment epithelial cells had undergone either atrophy or proliferation. Disease-specific granular lipopigments had accumulated in perikarya and processes of remaining cells and were infrequently associated with melanin within huge melanolipofuscin bodies and RPE cells of sessile and migrating na…
ALS-Related Mutant FUS Protein Is Mislocalized to Cytoplasm and Is Recruited into Stress Granules of Fibroblasts from Asymptomatic FUS P525L Mutation…
2017
Background: Amyotrophic lateral sclerosis (ALS) shows a strong genetic basis, with SOD1, FUS, TARDBP, and C9ORF72 being the genes most frequently involved. This has allowed identification of asymptomatic mutation carriers, which may be of help in understanding the molecular changes preceding disease onset. Objectives: We studied the cellular expression of FUS protein and the effect of heat-shock-and dithiothreitol-induced stress in fibroblasts from FUS P525L mutation carriers, healthy controls, and patients with sporadic ALS. Methods: Western blots and immunocytochemistry were performed to study the subcellular localization of FUS protein. Control and stressed cells were double stained with…
Electron microscopic study on the larval and adult corpus allatum of Oncopeltus fasciatus dallas (insecta, heteroptera)
1973
1. The ultrastructure of the corpora allata of last larval instars and adults of Oncopeltus was studied. The unpaired gland undergoes submicroscopic alterations and shows signs of degradation in old animals. The organ is partly covered and penetrated by corpus cardiacum tissue. Axons with different types of neurosecretory granules form synaptoid contacts with the corpus allatum cells.
Suprasellar Granular Cell Tumor
1992
A case of a suprasellar granular cell tumor, approximately 1.5 cm in diameter, in a 68-year-old woman is described. Diagnosis was established postoperatively by histopathological examination of the tumor tissue. The preoperative computed tomographic scan revealed a slightly hyperdense suprasellar mass with strong contrast enhancement. There was no evidence of calcification. The T1-weighted image on magnetic resonance imaging scan showed an isointense tumor with non-homogeneous enhancement after intravenous gadolinium diethylene-triamine-pentaacetic acid. In the proton-weighted image, the suprasellar mass presented a non-homogeneously enhanced signal. A non-homogeneous signal reduction was s…
Myelin Basic Protein synthesis is regulated by small non‐coding RNA 715
2012
Oligodendroglial Myelin Basic Protein (MBP) synthesis is essential for myelin formation in the central nervous system. During oligodendrocyte differentiation, MBP mRNA is kept in a translationally silenced state while intracellularly transported, until neuron-derived signals initiate localized MBP translation. Here we identify the small non-coding RNA 715 (sncRNA715) as an inhibitor of MBP translation. SncRNA715 localizes to cytoplasmic granular structures and associates with MBP mRNA transport granule components. We also detect increased levels of sncRNA715 in demyelinated chronic human multiple sclerosis lesions, which contain MBP mRNA but lack MBP protein.
Supravital Uptake of Cationic Dyes by Mast Cell Granules: A Light and Electron Microscope Study
1994
Methylene blue and neutral red were selected for staining mast cell granules by supravital injections. A new technique was applied for embedding in paraffin and Araldite without dislocation or loss of dye. Stabilization and electron microscopic identification of the dyes were achieved by transforming them into electron-dense precipitates using phosphomolybdic acid dissolved in a paraformaldehyde-glutaraldehyde mixture to preserve the ultrastructure of the tissues. It was found that in general the intensity of the light microscopic staining correlated directly with the electron density. Closer study revealed that not all cytoplasmic granules exhibited the same strong affinity for the cationi…
Histiocytosis with mixed cell populations
2016
Langerhans cell histiocytosis (LCH) and juvenile xanthogranuloma (JXG) are thought to originate from a common stem cell precursor, with divergent differentiation under different microenvironmental conditions. We describe an exceptional case of multiple cutaneous lesions in a 10-year-old boy, in which the coexistence of both LCH and JXG cell populations is found in every single lesion. The presence of Birbeck granules and CD207 (langerin) immunostaining in the LCH component would argue against the diagnosis of indeterminate cell histiocytosis (ICH). This unique case gives additional support to the hypothesis of a potentially common histogenesis for LCH and JXG.
A novel monoclonal antibody to a distinct subset of cutaneous dendritic cells.
1992
A monoclonal antibody was generated by immunizing rats with Langerhans cell (LC)–enriched epidermal cells obtained from BALB/c mouse earskin after epicutaneous application of the contact sensitizer 2,4-dinitrofluorobenzene (DNFB). The antibody 4F7 detects in normal mouse skin, few dermal cells showing the morphologic, phenotypic, and functional properties of accessory dendritic cells, but lacking Birbeck granules. The capacity to stimulate allogenic T cells in the mixed leucocyte reaction resembles that of freshly isolated LCs. After DNFB application, an increased number of 4F7+ dendritic cells are found in the dermis and, in addition, some labeled dendritic cells occur in the epidermis. So…
Idiopathic Acquired Leukonychia in a 34-Year-Old Patient
2009
We present a rare case of a 34-year-old patient with persistent, progressive, acquired leukonychia totalis and partialis. Idiopathic acquired leukonychia is a rare chromatic disorder of the nail not associated with other abnormalities and discernible etiology. Our case report did not link the inheritance of leukonychia with diverse clinical syndromes. To our knowledge, only five cases of idiopathic, acquired, true total leukonychia were found in literature. This case was the sixth patient with asymptomatic idiopathic, white fingernails, and toenails without a hereditary cause.
Botulinum A and the light chain of tetanus toxins inhibit distinct stages of Mg.ATP-dependent catecholamine exocytosis from permeabilised chromaffin …
1994
Susceptibilities of Mg.ATP-independent and Mg.ATP-requiring components of catecholamine secretion from digitonin-permeabilised chromaffin cells to inhibition by Clostridial botulinum type A and tetanus toxins were investigated. These toxins are Zn(2+)-dependent proteases which specifically cleave the 25-kDa synaptosomal-associated protein (SNAP-25) and vesicle-associated membrane protein (VAMP) II, respectively. When applied to permeabilised chromaffin cells they rapidly inhibited secretion in the presence of Mg.ATP but the catecholamine released in the absence of Mg.ATP, thought to represent fusion of primed granules, was not perturbed. The toxins can exert their effects per se in the abse…