Search results for "Skeleton"

Microstructural Organization of the Calcitic Skeleton of Terebratulid Brachiopods: Elementary Unit of the Carbonate Secretion

2013

Exploitation of Microtubule Cytoskeleton and Dynein during Parvoviral Traffic toward the Nucleus

2003

ABSTRACT Canine parvovirus (CPV), a model virus for the study of parvoviral entry, enters host cells by receptor-mediated endocytosis, escapes from endosomal vesicles to the cytosol, and then replicates in the nucleus. We examined the role of the microtubule (MT)-mediated cytoplasmic trafficking of viral particles toward the nucleus. Immunofluorescence and immunoelectron microscopy showed that capsids were transported through the cytoplasm into the nucleus after cytoplasmic microinjection but that in the presence of MT-depolymerizing agents, viral capsids were unable to reach the nucleus. The nuclear accumulation of capsids was also reduced by microinjection of an anti-dynein antibody. More…

Htid-1, the human homolog of the Drosophila melanogaster l(2)tid tumor suppressor, defines a novel physiological role of APC.

2007

Htid-1, the human counterpart of the Drosophila tumor suppressor gene lethal(2)tumorous imaginal discs (l(2)tid) encodes three splice forms translated into three cytosolic - Tid50, Tid48 and Tid46 - and three mitochondrial - Tid43, Tid40 and Tid38 - proteins. Here we provide evidence for the association of the endogenous Tid50/Tid48 proteins with the adenomatous polyposis coli (APC) tumor suppressor in normal colon epithelium, colorectal cancer cells and mouse NIH3T3 fibroblasts. Using the Glutathione S-transferase binding assay we show that the N-terminal region including the Armadillo domain (ARM) of APC is sufficient to bind the Tid molecules. Using immunoprecipitation and confocal micro…

Protein surplus myopathies and other rare congenital myopathies.

2002

The protein surplus myopathies have emerged as a newly recognized subgroup of morphologically defined myopathies within the spectrum of congenital myopathies because of the accumulation of protein aggregates, some of them mutant proteins. Currently, nosologic, including molecular criteria include desmin-related myopathies, actinopathies, and hereditary inclusion body myopathies, whereas hyaline body myopathy is still a putative form of protein surplus myopathy because of lack of any molecular data. The congenital myopathies (CM), foremost including nemaline and myotubular myopathies, have given evidence that, despite their epidemiologic rarity, the molecular age has dawned in CM and has eve…

Nuclear actin aggregation is a hallmark of anti-synthetase syndrome-induced dysimmune myopathy

2015

Objective: To analyze antisynthetase syndrome–associated myositis by modern myopathologic methods and to define its place in the spectrum of idiopathic inflammatory myopathies (IIMs). Methods: Skeletal muscle biopsies from antisynthetase syndrome–associated myositis and other IIMs from different institutions worldwide were analyzed by histopathology, quantitative PCR, and electron microscopy. Results: Myonuclear actin filament inclusions were identified as a unique morphologic hallmark of antisynthetase syndrome–associated myositis. Nuclear actin inclusions were never found in dermatomyositis, polymyositis, sporadic inclusion body myositis, autoimmune necrotizing myopathy associated with si…

Adhesion, growth and cytoskeletal characteristics of 8701-BC breast carcinoma cells cultured in the presence of type V collagen

1990

Type V collagen is one of the minor components of the extracellular matrix (ECM) whose content is increased in cases of ductal infiltrating carcinomas of the breast. In order to clarify its biological role, we have investigated the effect of this molecule, both as substrate and as soluble factor, on the behaviour of a breast carcinoma cell line (8701-BC) grown in vitro. Cell-collagen adhesion was monitored for 24 h from plating in the absence or presence of serum. The influence of type V collagen on cell growth was followed during 9 days of culture, and the actin-vinculin arrangement was studied by simultaneous fluorescent immuno-staining. The results indicate that type V collagen is not a …

Endothelial nitric oxide synthase upregulation in the guinea pig organ of Corti after acute noise trauma.

2004

Endothelial nitric oxide synthase (eNOS) upregulation was identified 60 h after acute noise trauma in morphologically intact cells of the reticular lamina in the organ of Corti of the guinea pig in the second turn of the cochlea. Using gold-coupled anti-eNOS antibodies and electron microscopy, it was shown that eNOS expression was upregulated in all cell areas and cell types except inner hair cells. Furthermore, eNOS was found in the organelle-free cytoplasm and in mitochondria of various cell types. The density of eNOS in mitochondria was considerably higher compared with the surrounding cytoplasm. Since eNOS activity is regulated by calcium, the eNOS detection was combined with calcium pr…

Radiolabeled DNase, a potential indicator for noninvasive detection of tissue damage

1983

Pancreatic DNase I was labeled with 131I or fluorescamine and injected IV into NMRI mice bearing a sarcoma 180. Of the injected tracer, 1.5%-2% was found to accumulate per g tumor. In sections of tumor tissue DNase was localized in damaged cells in solid and necrotic tumor regions. This binding is most probably due to specific interaction of DNase with actin, an ubiquitous cytoskeletal protein. Two-component blood clearance with a rapid first component (two-thirds of applied radioactivity) was observed. The labeled tumor could easily be visualized by gamma camera imaging. The findings suggest DNase to be a potent radiopharmaceutical for imaging damaged tissue, occurring in malignant tumors …

Intermediate filaments of normal and neoplastic tissues of the female genital tract with emphasis on problems of differential tumor diagnosis

1984

Cytokeratins of normal epithelia and of some neoplasms of the female genital tract were studied by immunofluorescence microscopy of frozen sections and by two-dimensional gel electrophoresis of cytoskeletal proteins from microdissected tissues. All normal epithelia were stained with the monoclonal cytokeratin antibody KG 8.13 whereas certain monoclonal antibodies stained only simple epithelia. As revealed by gel electrophoresis the normal epithelia of the ovarian surface, oviduct, endometrium and endocervix contained cytokeratin polypeptides Nos. 7, 8, 18 and 19. In contrast, stratified exocervical epithelium showed a much more complex pattern (polypeptides No. 1, 2, 4, 5, 6, 11, 13, 14, 15…

The disruption of myofibre structures in skeletal muscle after forced lengthening contractions

1998

Specific antibodies against structural proteins (actin, desmin, dystrophin, fibronectin) of muscle fibres were used to study the effect of forced lengthening contractions on muscle microarchitecture. Tibialis anterior (TA) muscle of male Wistar rats were subjected to 240 forced lengthening contractions. At consecutive time points (0, and 6 h, 2, 4, and 7 days) after stimulation, the TA muscle was excised for biochemical and histological assays. β-Glucuronidase activity, a quantitative indicator of muscle damage, showed increased values 2–7 days after the lengthening, peaking on day 4 (11.7-fold increase). A typical course of histopathological changes (myofibre swelling, necrosis and regener…