Search results for "neurofilament"
showing 10 items of 59 documents
Heterogeneity of intermediate filament expression in human testicular seminomas.
1990
Testicular seminoma has in the past been considered to represent a germ cell tumor incapable of further differentiation. In recent years this view has been challenged on the basis of morphologic and chromosomal studies. Moreover, studies of intermediate filaments (IF) of seminoma cells have provided evidence of the capability of seminoma cells to differentiate in different directions. In the present study of the IF protein profile of 26 human testicular seminomas, using frozen as well as formalin-fixed, paraffin-embedded tissues, we report evidence of a heterogeneous differentiation potential inherent in these neoplasms. Thus, in 4 of the seminomas neither cytokeratins nor vimentin were det…
Pleomorphic pineocytoma with extensive neuronal differentiation: report of two cases
1994
Two pineal parenchymal tumors are presented, arising in a 54-year-old man and a 72-year-old woman; respectively. They showed isomorphic, cellular areas of small cells, often with characteristic pineocytomatous rosettes, and of medium-sized cells, as well as less cellular regions with highly pleomorphic, often ganglioid large cells. Immunohistochemistry disclosed extensive neuronal differentiation. There was intense positivity for neurofilament protein and microtubule-associated protein 2 in the pleomorphic areas and more variable expression in the isomorphic regions. Diffuse synaptophysin positivity was seen, accentuated along the borders of pleomorphic cells and in the rosettes, as well as…
Esthesioneuroblastoma: Ultrastructural, immunohistological and biochemical investigation of one case
1984
A case of esthesioneuroblastoma, the pathological diagnosis of which almost always causes great difficulties, was investigated ultrastructurally, biochemically, and immunohistologically, using antibodies against the five known types of intermediate filaments [keratin, vimentin, desmin, glial fibrillary acidic protein (GFAP) and neurofilaments]. The tumour cells did not react with antibodies against any of the five intermediate filament proteins. Ultrastructural investigations showed dense cored secretory granules in the cytoplasm and cell processes. Thus, immunohistology offers by "exclusion" a differential diagnosis to avoid often misdiagnosed tumours (undifferentiated carcinomas, embryona…
Establishment and Characterization of Two Merkel Cell Tumor Cultures
1994
Two Merkel cell tumor cultures (MC-MA1, MC-MA2) have been established from metastases of typical Merkel cell tumors. The mestastases in vivo were characterized by co-expression of cytokeratins 8, 18, 19, 20 and neurofilaments, presence of intermediate filament whirls, expression of synaptophysin, neuron-specific enolase, and chromogranin A, rare and weak immunostaining for plakoglobin but absence of cadherins and desmoplakins. Both cultures grow, using supplemented RPMI medium on human irradiated fibroblast feeder layers, as loosely arranged floating small aggregates. Their karyotypes are mostly hyperdiploid. The mean doubling times were about 84 h in the first 8 months and later increased.…
Fate of autologous dermal stem cells transplanted into the spinal cord after traumatic injury (TSCI)
2003
Rat dermis is a source of cells capable of growing in vitro and, in appropriate conditions, forming floating spheres constituted by nestin-positive cells. We have clonally grown these spheres up to the 15th generation. These spheres can be dissociated into cells that differentiate in vitro under appropriate conditions, these cells are labeled by antibodies to immature neuron markers such as nestin and beta-tubulin III and, later, to mature neuron markers such as microtubule-associated protein 2 and neurofilaments. However, most cells are positive to the astroglial marker glia fibrillary acidic protein (GFAP). When sphere-derived cells are transplanted into the spinal cord after traumatic in…
Neuronal markers in the rodent pineal gland ? an immunohistochemical investigation
1990
Although some embryological and morphological features speak in favour of a neuronal character of rodent pinealocytes, histochemistry and ultrastructure let this issue appear controversial. Using antibodies to different neurofilaments, the neural adhesion molecule L1, synaptophysin and tubulin as neuronal markers, the pineal glands of rat and guinea-pig were studied by means of immunofluorescence. Neurofilament-immunoreactivity was present in some rat pineal nerve fibers and in the majority of guinea-pig pinealocytes, L1 decorated rat intrapineal nerve fibers, synaptophysin was almost ubiquitously distributed in the pineal of both species, while tubulin-immunofluorescence was seen in nerve …
Effect of high-caloric nutrition on serum neurofilament light chain levels in amyotrophic lateral sclerosis
2020
Recent publications showed that circulating neurofilaments (Nfs) may be used as a diagnostic biomarker distinguishing amyotrophic lateral sclerosis (ALS) from ALS mimics with high sensitivity and specificity.1–3 Furthermore, it has been shown that patients with higher Nf levels show faster disease progression1 and shorter survival.2 3 Nf levels remain rather stable during the course of disease.2 Current literature suggests that the diagnostic value of neurofilament light chains (NfL) and phosphorylated neurofilament heavy chains in cerebrospinal fluid is about equal, whereas in blood NfL seems to be superior.4 In this study, we investigated the effect of a high-caloric fatty diet (HCFD) on …
Patterns of Expression and Organization of Cytokeratin Intermediate Filaments
1985
Cytokeratins are a large multigene family comprising two polypeptide types, i.e. acidic (type I) and basic (type II) ones, which are distinguished on the basis of immunological, peptide mapping, mRNA hybridization, and primary amino acid sequence data. The acidic (type I) cytokeratins can be subdivided into at least two different subtypes on the basis of their carboxy-terminal sequences. Considerable interspecies conservation of sequences exists, even extending to the 3'-non-coding mRNA regions. Different pairs of type I and II cytokeratins show different resistance to dissociation in urea. Sequence differences of the type I cytokeratins containing functional domains may be an explanation o…
Monoclonal antibodies SMI 311 and SMI 312 as tools to investigate the maturation of nerve cells and axonal patterns in human fetal brain
1998
Neurofilaments, which are exclusively found in nerve cells, are one of the earliest recognizable features of the maturing nervous system. The differential distribution of neurofilament proteins in varying degrees of phosphorylation within a neuron provides the possibility of selectively demonstrating either somata and dendrites or axons. Non-phosphorylated neurofilaments typical of somata and dendrites can be visualized with the aid of monoclonal antibody SMI 311, whereas antibody SMI 312 is directed against highly phosphorylated axonal epitopes of neurofilaments. The maturation of neuronal types, the development of area-specific axonal networks, and the gradients of maturation can thus be …
Localization of the giant axonal neuropathy gene to chromosome 16q24
1998
Giant axonal neuropathy (GAN) is a degenerative disorder of the peripheral nerves that is inherited as an autosomal recessive trait, presenting in early childhood and progressing to death, usually by late adolescence. Diagnosis is made by peripheral nerve biopsy, in which a striking pathological finding is seen--fibers distorted by giant axonal swellings filled with densely packed bundles of neurofilaments (the primary intermediate filament in neurons), with segregation of other axoplasmic organelles. In addition to disorganized neurofilaments in nerve, disorganization of other members of the intermediate filament family of proteins is seen in other tissues; this implies that the underlying…