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D Dahl

Publications and source records attributed to D Dahl.

At least 145 records · Page 8Linked to original sources
PubMed1984

Immunocytochemistry of neuronal and glial markers in retinoblastoma.

An immunocytochemical study of 30 retinoblastomas was carried out using antibodies to neuronal and glial markers. The tumours were found to react with antibodies to neuron-specific enolase (NSE), a marker for neuronal elements, and S-100 and glial fibrillary acidic protein (GFAP), both of which are proteins present in glia. Two distinct cell populations were found within the tumour: the first, composed of anaplastic tumour cells at various stages of differentiation, showed both NSE and S-100 immunoreactivity; the second cell type, which immuno-stained for S-100 and GFAP, resembled mature glial cells. The results of this study indicate that the retinoblastoma may arise from a pluripotential primitive cell partially retaining neuronal and glial characteristics.

Eye Neoplasms↗
PubMed1984

Ultrastructural and histochemical evidence for differentiation of intraocular locus coeruleus grafts and invasion of the host iris by central neurites and glia.

Intraocular grafts of dorso-lateral pons, including the noradrenaline-containing cell group locus coeruleus, have been studied with ultrastructural and histochemical techniques. Also, the invasion of neuronal and glial constituents from the grafts into the iris of the host animal is described. In mature brain grafts, aggregates of locus coeruleus neurons were easily discernible with monoamine histofluorescence. These cells had an ultrastructural appearance very similar to that in situ. Numerous somatic spines were frequently associated with synaptic specializations, and monoamine-containing vesicles could be found scattered in the cytoplasm of the locus coeruleus cells. Large neurons of the nucleus tractus mesencephalici nervi trigemini were also found. These cells were neurofilament-immunoreactive just as in situ, and were ultrastructurally characterized by size, distribution of the granular endoplasmic reticulum and abundant large terminals in synaptic contact with their somata and processes. All grafts showed a vigorous astroglial proliferation, evidenced both with immunohistochemistry of glial fibrillary acidic protein and electron microscopy. The astroglial cells were more numerous, larger and with more processes than in adult in situ counterparts. At the attachment site of the brain stem grafts, the iris dilator plate was entirely changed ultrastructurally by a vigorous invasion of neuronal and astrocytic processes. The normal, loose connective tissue stroma of the iris was replaced by layers of almost exclusively central nerve fibres and astrocytes respectively. Monoamine histofluorescence demonstrated an extreme adrenergic hyperinnervation of the iris at the attachment site of the graft, compared to the normal sympathetic ground plexus, whereas neurofilament immunohistochemistry did not visualize any substantial ingrowth of such positive central nerve fibres. Immunohistochemistry of glial fibrillary acidic protein strongly supported the ultrastructural evaluation, showing profound astroglial invasion deep into the iris stroma. Electron microscopic identification of central nerve fibres in the iris showed numerous adrenergic locus coeruleus fibres with small dense-core vesicles. Also, bundles of thin, central, unmyelinated axons were found deep in the iris as well as occasional dendrites. Both large dense-cored and small clear vesicles were encountered in the iris fibres of brain graft origin. Axo-dendritic synaptic specializations formed by locus coeruleus-derived adrenergic fibres were found in the iris.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1984

Cell-specific domains of glial- and muscle-type intermediate filament proteins. Immunoaffinity chromatography and immunoblotting study of GFA protein and desmin.

In order to localize the cell specific domains of glial- and muscle-type intermediate filaments, the purified subunits (bovine GFA protein and chicken desmin) were fragmented and the digests passed through immunoaffinity columns or stained by the immunoblotting procedure to determine which fragments reacted with the monospecific polyvalent antisera. The following fragments were found immunoreactive according to these criteria: 30 K (GFA) and 33 K (desmin) N-bromosuccinimide fragments (tryptophan cleavage); 35 K (GFA) and 39 K (desmin) 2-nitro-5-thiocyanobenzoic acid fragments (cysteine cleavage); 18 K (GFA) and 9 K (desmin) cyanogen bromide fragments. Fragmentation of GFA protein was also accomplished using proteolytic digestion with chymotrypsin and trypsin. Two resistant core polypeptides, one about 37 K and stable in the chymotryptic digests and one about 21 K and stable in the tryptic digests bound specifically to the immunoaffinity columns. The 21 K tryptic fragment was found to contain the 18 K cyanogen bromide fragment. The fragmentation patterns support recently published structural domain models for intermediate filament proteins. The immunochemical findings indicate that the immunoreactive regions of GFA protein are located in the aminoterminal region of the middle domain of these models (coil I), while they appear to be situated in the aminoterminal headpiece of the protein in the case of desmin.

Amino Acid Sequence↗
PubMed1984

Regenerating dorsal roots and the nerve entry zone: an immunofluorescence study with neurofilament and laminin antisera.

Dorsal spinal roots were crushed in 30 rats at the lumbar or thoracic level. Peripheral roots, nerve entry zone, and spinal cord were studied 3 to 5 weeks after operation by immunofluorescence with neurofilament, glial fibrillary acidic (GFA), and laminin antisera. As previously shown in sciatic nerve undergoing Wallerian degeneration, reactive Schwann cells forming the bands of Büngner stained intensely with laminin antisera. Within these bands bundles of regenerating axons were present as indicated by double staining with laminin and neurofilament antisera. With very few exceptions, regenerating axons were not observed in the laminin-negative intramedullary division of the root. This also appeared to be the case when the dome-shape protrusion of central nervous system tissue forming the intramedullary division was surrounded by regenerating fibers. Compared with GFA antisera, laminin antisera allowed a better identification of the boundary between the central and peripheral nervous systems. In the central nervous system only blood vessels were laminin-positive, whereas Schwann cells' processes were decorated by GFA antisera in peripheral roots, the staining being stronger in reactive Schwann cells.

Animals↗
PubMed1984

Neurofilament and glial fibrillary acid protein-related immunoreactivity in rodent enteric nervous system.

Using antisera raised against neurofilaments and the glial fibrillary acidic protein (GFAP) we have examined the appearance and distribution of neurofilament- and GFAP-like immunoreactivity in the enteric nervous system of rat, mouse and guinea-pig. In whole mounts of the external circular and longitudinal muscle layers, including the myenteric plexus, a high number of neurofilament-positive perikarya were visualized both in the ganglia and in the circularly running interconnecting strands in all three species. These cells were large, usually with eccentrically placed nuclei and single, relatively thick neurofilament-positive processes. In addition, in guinea-pig myenteric plexus a small number of cells with multiple processes could be seen. Both in the longitudinal and circular interconnecting strands a large number of thin, smooth, neurofilament-positive fibres were observed. This regular network of ganglia and strands was superimposed on a sparse system of thin, usually individual neurofilament-positive fibres in the underlying circular muscle layer. Cryostat sections revealed neurofilament-positive cell bodies in the submucous plexus, whereas fibres showing neurofilament-like immunoreactivity were observed in all layers of the gut wall, with the exception of the epithelium. In whole mounts including rat and mouse myenteric plexus, a large number of cells and fibres showing GFAP-like immunoreactivity were visualized. The GFAP-positive cells were smaller and more numerous than the neurofilament-positive ones. They were present both within the ganglia and in the interconnecting strands. Several short fluorescent processes could frequently be seen emanating from the cell body. Both the strands and the ganglia contained a high number of thin, GFAP-positive fibres. Fluorescent fibres and cells were also observed in the circular muscle layer. In sections of rat and mouse small intestine, cells were observed throughout the gut wall, with the exception of the epithelium. Double labelling experiments clearly showed that neurofilament- and GFAP-positive cells represented separate cell populations. Furthermore, GFAP-positive cells and fibres outlined the neurofilament-positive perikarya. It is thus likely that the GFAP-positive cells represent enteric glial cells. The pre- and postnatal development of neurofilament- and GFAP-like immunoreactivity was studied in whole mounts from rat embryos and pups. Furthermore, the presence of neurofilament and GFAP-positive fibres was observed in whole mount preparations of rat and mouse mesenterium.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1984

Laminin in rat sciatic nerve undergoing Wallerian degeneration. Immunofluorescence study with laminin and neurofilament antisera.

Immunofluorescence with laminin antisera revealed a striking change in the localization of this basal membrane glycoprotein in rat sciatic nerve as a result of Wallerian degeneration. The staining was confined to the endoneurium in normal sciatic nerve and during the first days of degeneration. On day 11 endoneurial tubes were no longer identified in the distal stump of crushed nerves or of nerves that had been transected and tightly ligated to prevent regeneration. In both crushed and ligated nerves proliferating Schwann cells forming the cell-bands of Büngner were intensely laminin positive. With double-labeling experiments, laminin and neurofilament antisera revealed similar but not identical staining patterns in crushed nerves, which suggests a close relation between laminin and regenerating axons. Crushed nerves had recovered their normal appearance 18 days after operation while anti-laminin reactivity was decreased in parts of ligated nerves undergoing fibrosis. The localization of laminin in reactive Schwann cells was confirmed by electron microscopy using the indirect immunoperoxidase procedure. Axons did not contain reaction product.

Animals↗
PubMed1984

Normal rabbit Merkel cells do not express neurofilament proteins.

Three hundred and five normal Merkel cells (MC) were studied in rabbit lip specimens by a double indirect immunofluorescence technique using both neurofilament (NF) antiserum and a monoclonal antibody to rabbit MC. NF proteins were not found to be expressed in MC. This suggests that MC are not neural cells and that NF-positive neuroendocrine carcinomas of the skin do not derive from MC.

Animals↗
PubMed1984

Cellular origin and biosynthesis of rat optic nerve proteins: a two-dimensional gel analysis.

High resolution 2DGE (two-dimensional gel electrophoresis) was used to characterize neuronal and glial proteins of the rat optic nerve, to examine the phases of intraaxonal transport with which the neuronal proteins are associated, and to identify the ribosomal populations on which these proteins are synthesized. Neuronal proteins synthesized in the retinal ganglion cells were identified by injecting the eye with L-[35S]methionine, followed by 2DGE analysis of fast and slow axonally transported proteins in particulate and soluble fractions. Proteins synthesized by the glial cells were labeled by incubating isolated optic nerves in the presence of L-[35S]methionine and then analyzed by 2DGE. A number of differences were seen between filamentous proteins of neurons and glia. Most strikingly, proteins in the alpha- and beta-tubulin region of the 2D gels of glial proteins were distinctly different than was observed for axonal proteins. As expected, neurons but not glia expressed neurofilament proteins, which appeared among the slow axonally transported proteins in the particulate fraction; significant amounts of the glial filamentous protein, GFA, were also labeled under these conditions, which may have been due to transfer of amino acids from the axon to the glial compartment. The fast axonally transported proteins contained relatively large amounts of high-molecular-weight acidic proteins, two of which were shown to comigrate (on 2DGE) with proteins synthesized by rat CNS rough microsomes; this finding suggests that rough endoplasmic reticulum may be a major site of synthesis for fast transported proteins. In contrast, the free polysome population was shown to synthesize the principal components of slow axonal transport, including tubulin subunits, actin, and neurofilament proteins.

Animals↗
PubMed1984

Early appearance of desmin, the muscle-type intermediate filament protein, in the rat embryo.

Antisera raised to desmin, the protein subunit of muscle-type intermediate filaments (IFs), were used to study by indirect immunofluorescence and immunoperoxidase procedures the early development of skeletal muscle in the rat embryo. The specificity of the antisera (Dahl D, Bignami A: J Histochem Cytochem 30:207, 1982) was confirmed by immune blotting on chicken gizzard extracts and purified antigen. Desmin-positive cells were first observed on day 12 by immunofluorescence and on day 13 by the immunoperoxidase procedure. Desmin immunoreactivity was not found in caudal somites in which the dermatome was present, i.e., somites where the dorso-lateral part had maintained its definite boundaries and epithelioid characteristics. Desmin-positive cells were observed within the myotome of cranial somites where the dermatome had disappeared. Compared to day 13, desmin-positive cells had extended ventrally on day 14, while on day 15, they were found in the skeletal musculature of the trunk and the limbs.

Animals↗
PubMed1984

Expression of intermediate filaments in established human lung cancer cell lines. An indicator of differentiation and derivation.

A panel of established human pulmonary cancer cell lines, representing the major histopathologic groups according to the World Health Organization (WHO) classification (WHO 1, squamous cell carcinoma; WHO 2, small cell carcinoma; WHO 3, adenocarcinoma; WHO 4, large cell carcinoma) were examined for their expression of various types of intermediate filaments in order to determine their phenotypic differences and to attempt to disclose their histogenetic origin. The cells were investigated with antibodies specific for cytokeratin, vimentin, and neurofilament polypeptides with both immunofluorescence microscopy and immunoblotting techniques. Squamous cell carcinoma and adenocarcinomas expressed cytokeratin in accordance with the epithelial nature of these tumors but not neurofilament polypeptides. Small cell carcinomas, on the other hand, were positive for neurofilaments but negative for keratin. In contrast to small cell carcinoma, adenocarcinoma, and squamous cell carcinoma, one cell line derived from large cell carcinoma appeared to express both neurofilaments and keratin. All cell lines studied also contained variable amounts of vimentin, a phenotypic characteristic obtained by many cells under in vitro conditions. The results demonstrate, in accordance with our earlier observations in vivo, a distinctly divergent expression of intermediate filament proteins in different types of lung cancers. The persistence of this phenotypic heterogeneity in vitro consolidates the use of cell cultures as useful models to study the biologic behavior and interrelationships of lung cancers. Based on the present studies, and taking into account the occurrence of mixed forms of lung cancers, we present a hypothetical scheme of the histogenetic derivation of different types of lung cancers.

Adenocarcinoma↗
PubMed1984

Glial fibrillary acidic protein-like immunoreactivity in the iris: development, distribution, and reactive changes following transplantation.

Using immunohistochemistry with antisera raised against the glial fibrillary acidic protein (GFA), we have studied the appearance and distribution of GFA-like immunoreactivity in whole mounts of rodent iris and in sectioned cat and cow iris. In the adult rat iris, a dense plexus of GFA-positive fibers was seen in both the dilator plate and the sphincter. The fluorescent fibers formed large meandering bundles and a dense irregular network of thinner fibers. In the sphincter, mainly thinner fibers were seen. Thin fibers were also seen winding around blood vessels in the dilator plate. In adult mouse iris, the GFA-positive fibers had a quite different distribution with a few radially oriented fiber bundles superimposed on a more regular network of thinner fibers. Adult guinea pig irides showed still another pattern of GFA-positive fibers with a low number of bundles and thinner fibers forming a sparse irregular network. In thicker fiber bundles of all three rodent species, as well as at branching sites of the thinner fibers, negative or weakly fluorescent swellings surrounded by GFA-like immunoreactivity were present. These structures probably represent the cellular origin of the GFA-positive fibers. Thick, strongly fluorescent fiber bundles, as well as numerous thinner fibers, were seen in sections of cat and cow iris. Prenatally, fibers were visualized at embryonic day 18 in the rat. In these irides as well as in irides from 21-day-old embryos and 1-day-old pups, most fibers were organized in a gradually increasing system of thin meandering fiber bundles that showed limited branching. At postnatal day 6, a more mature network of thinner fibers had developed between the now more numerous fiber bundles. No obvious increase or decrease in the amount of GFA-positive fibers was seen in irides grafted to the anterior eye chamber of adult rat recipients examined 1 and 6 days after grafting. However, in these irides, as well as in the host irides, strongly fluorescent spider-like cells with short branching processes and a negative nucleus were seen. These cells were more numerous and more strongly fluorescent in grafted irides as compared to recipient irides and in the 6-day iris grafts as compared to the 2-day grafts. In all probability, the GFA-positive fibers and cells forming a network in adult irides from different species and in embryonic and grafted rat irides represent Schwann cells and their processes. The cellular origin of the spider-like cells in the iris grafts is less clear.

Animals↗
PubMed1984

Astrocytes in smears of CNS tissues as visualized by GFA and vimentin immunofluorescence.

A technique is described using immunocytochemistry in which smears of fresh unfixed brain tissue combined with antibodies against glial fibrillary acidic protein (GFA) or vimentin is used to visualize astrocytes. In rats the amount of GFA-positive cells was much lower in cortex cerebri smears than in smears of other cortical regions such as the olfactory bulb, hippocampus and cerebellum. A few vimentin positive astrocytes were also seen in hippocampus and cortex cerebri smears. Smears of spinal cord white matter contained astrocytes with very long processes as visualized by GFA immunohistochemistry while grey matter astrocytes had somewhat shorter processes. Using either anti-GFA or anti-vimentin procedures, smears of neonatal rat brain showed immature star-shaped cell-like structures. In contrast, neonatal spinal cord smears contained typical spidershaped astrocytes equally well visualized with both antisera. Both GFA- and vimentin-positive astrocytes were visualized in smears of normal human brain tissue, though the number of vimentin-positive cell bodies was very low. To our knowledge, this is the first description of vimentin-positive astrocytes in normal human brain. For studies of astrocyte development and morphology the technique has several advantages. It allows inspection of separated individual cells without sectioning, and, since no tissue culture is performed there is no risk that the amounts and/or distribution of either GFA or vimentin will be changed. Thus the technique facilitates comparative studies of GFA- and vimentin-positive astrocytes in different areas of the normal CNS as well as in different experimental and pathological conditions. We conclude that GFA and vimentin immunocytochemistry of CNS smears is a rapid and useful method of visualizing individual astrocytes in animals and man.

Animals↗
PubMed1983

Immunohistochemical differences between neurofilaments in perikarya, dendrites and axons. Immunofluorescence study with antisera raised to neurofilament polypeptides (200K, 150K, 70K) isolated by anion exchange chromatography.

Neurofilament (NF) proteins (70K, 150K and 200K D) were isolated from 2 M urea extracts of bovine spinal cord by anion exchange chromatography. Antisera to the individual NF polypeptides were produced in rabbits and affinity-purified on Sepharose columns prepared with their own antigen. The NF antisera were completely absorbed by their own antigen at protein concentrations that did not decrease the staining when the absorption was conducted with the heterologous NF antigens. Partial absorption (decrease in immunofluorescence titer) occurred at higher concentrations of the heterologous antigens. Cross-reactivity between the polypeptides of the NF triplet could not be detected by double immunodiffusion. The antisera formed immunoprecipitin lines only when reacted with their own antigen. Conversely, cross-reactivity was demonstrated by the immune blotting procedure. Anti-70K stained all three NF polypeptides. Anti-200K and anti-150K stained both 200K and 150K but not 70K, the main reaction being with their own antigen. The antisera were rendered monospecific by adsorption of the common antigenic determinants on Sepharose columns prepared with the heterologous NF antigens. The localization of the NF proteins was studied by immunofluorescence on cryostat sections of rat brain, cerebellum, spinal cord and posterior root ganglia. All NF antisera (anti-70K, anti-150K and anti-200K) stained axons including Purkinje cell baskets with identical pattern. Spinal cord motor neurons, posterior root ganglia neurons and pyramidal neurons in the cerebral cortex stained with anti-70K and anti-200K. No staining of neuronal perikarya and dendrites was observed with anti-150K. Aluminium-induced neurofibrillary tangles in rabbit spinal cord stained with anti-70K and anti-200K. The tangles were not decorated by anti-150K. It is concluded that a marked difference exists in the concentration of 150K depending on the location, i.e., cell body or axon; or, alternatively, that 150K undergoes modification of antigenic sites within the axon so that it may not be recognized immunologically as a component of the neurofilament within perikarya and dendrites.

Animals↗
PubMed1983

Autologous peripheral nerve grafting into murine brain as a model for studies of regeneration in the central nervous system.

Autologous sciatic nerve was grafted into rat brain by (i) passing an 8-mm segment of nerve tied to a straight surgical needle through two craniotomy holes ("through-and-through" model); (ii) inserting a small tube of polyethylene containing the 8-mm nerve piece ("nerve-within-tube" model). Longitudinally oriented neurofilament-positive fibers were consistently observed within the graft. Compared with the through-and-through model, axonal sprouting in the nerve-within-tube model followed a slow-motion pattern so that a growing front of regenerating axons could be easily identified and more easily related to the cellular events occurring in Wallerian degeneration. In the through-and-through model, regenerated axons at the brain-nerve interface followed a disorganized, tortuous course so that direct continuity between brain and graft was difficult to demonstrate. The reverse was true in the nerve-within-tube model, i.e., axons penetrated directly into the graft. The difference in orientation of axonal growth at the brain-graft interface appeared to be related to the glial reaction. In the through-and-through model, reactive astrocytes formed a mesh of randomly oriented fibers in the damaged brain tissue facing the graft (anisomorphic gliosis). Conversely, longitudinally oriented fibers extended directly from the brain to the graft in the nerve-within-tube model, where brain damage was substantially reduced (isomorphic gliosis). A different type of glial fibrillary acidic (GFA) protein-positive fibrous structures was identified in the graft. Compared with reactive astrocytes, these structures were more elongated, more uniform in diameter, and less brightly immunofluorescent. Moreover, they were present throughout the graft, whereas astrocytes were confined to the distal end of the transplant, i.e., the part of nerve close to the brain-graft interface. Based on previous reports in the literature we interpret these GFA protein-positive structures as reacting Schwann cells.

Animals↗
PubMed1983

Immunocytochemical studies of Alzheimer neuronal perikarya with intermediate filament antisera.

Isolated neuronal perikarya from the brains of patients with Alzheimer's disease were examined in indirect immunofluorescence microscopy with different types of specific antisera against the subunit proteins of cytoskeletal intermediate filaments. From 30 to 50% of the neurofibrillary tangles were stained with antisera against each of the neurofilament triplet proteins, but not with antisera against glial fibrillary acidic protein, vimentin, desmin or cytokeratin. Polyacrylamide gel electrophoresis of Alzheimer perikaryal fractions showed polypeptide patterns markedly similar to control neuronal fractions. Our results thus suggest either that the Alzheimer neurofibrillary tangles and the antigenic neurofilament triplet protein fractions may contain related antigenic determinants or that unaffected perikaryal neurofilament material is associated with the tangles.

Alzheimer Disease↗
PubMed1983

Astrocytic development in fetal parietal cortex grafted to cerebral and cerebellar cortex of immature rats.

Pieces of cortex cerebri anlage were dissected out from 16- to 17-day-old fetuses and transplanted to the cortical and cerebellar regions of 5- to 6-day-old rat pups. Twelve animals with grafts in the cortical region and 5 animals with grafts in the cerebellar region were studied 1.5-4 months later. Cresyl violet stained sections revealed no gross difference in either cell morphology, cell density or cell distribution between grafts in the two locations. A molecular layer-like zone was present on all free surfaces of the grafts, whether facing a ventricle or the meninges. The astrocytic development was studied using immunohistochemistry with antibodies against glial fibrillary acidic protein, (GFA), and the S-100 protein. Both antibodies visualized starshaped astrocytes and perivascular membranes surrounding blood vessels. Semi-quantitative measurements as well as computerized image analysis showed that the total amount of GFA-like immunoreactivity was much higher in both types of grafts than in corresponding host cortex cerebri. No differences in amount of S-100-like immunoreactivity could be demonstrated. As S-100 is thought to be a more general astrocytic marker than GFA, this suggests that the difference in GFA-like immunoreactivity is due mainly to an increased amount of GFA within the individual astrocytes. It is concluded that grafts of fetal cortex cerebri pieces to the CNS of young hosts develop a profound astrocytic reaction characterized by an increased amount of GFA-like immunoreactivity.

Animals↗
PubMed1983

Growth and gliotic response of astrocytes in vitro.

We investigated the development of astrocytes in mechanically dissociated primary cultures of foetal and neonatal rat brain grown in different culture media using immunofluorescence and antiserum to glial fibrillary acidic protein (GFAP). GFAP-positive cells developed at a time corresponding to the 16th day of embryonic development and initially grew more slowly in Dulbecco's modified Eagle's Medium (DMEM) than in Medium 199 (M199) or Modified Eagle's Medium (MEM), but as the cultures matured a greater proportion of GFAP-positive cells was obtained in DMEM, resulting in relatively pure populations of GFAP-positive cells after 1-2 months in vitro. GFAP-positive cells comprised process-bearing and fibroblastoid cell types and cells with intermediate morphology. Cultures in DMEM were also characterized by the appearance after 8-18 days in vitro of thick long bands of glial processes surrounding cyst-like spaces. The morphological change may represent a gliotic reaction to necrosis in vitro.

Animals↗