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At least 19 recordsLinked to original sources
PubMed1979

Argentophil neuronal perikarya and neurofibrils induced by postmortem trauma and hypertonic perfusates.

Argentophil neuronal perikarya and perikaryal neurofibrils similar to those illustrated in Ramón y Cajal's classical studies have in the present investigation been found to be manifestations of the chromophil neuron. Conclusive evidence of such association was obtained by silver impregnation with the Bodian technique of sections previously stained with cresyl violet. Regardless of the fixative used, silver-impregnated neurofibrils were evident when (1) normal tissues were fixed by immersion or unsuccessfully fixed by perfusion, (2) normal tissues were exposed and touched after death but before perfusion with the fixative, or (3) flow of perfusates was compromised by the effect of an experimental procedure, as well as when (4) a hypertonic saline solution was used in the first perfusate. These cytologic peculiarities were still discernible after 24 h of postmortem autolysis following a delay in removal of the brain or in immersion of the exposed brain in the fixative. After immersion fixation, argentophilia and chromophilia occurred ubiquitously in the brain of the newborn guinea pig; however, argentophil neurofibrils were noted in the absence of chromophil neurons in the brain stem of the newborn rat, rabbit and cat. After fixation by perfusion, perikaryal neurofibrils were not impregnated in either newborn or old animals or in animals with facial nerve transection. Affinity for Congo red or birefringency, exhibited by neurons with marked neurofilbrillary changes in human senile brain atrophy, were absent in the present material. On the basis of the current light-microscopic observations, it is concluded that argentophilia of neuronal perikarya and perikaryal neurofibrils is another manifestation of the chromophil neuron induced by postmortem trauma and of the ocellate neuron elicited by perfusion with hypertonic saline.

Age Factors↗
PubMed1975

Chemical pathology of neurofibrils. Neurofibrillary tangles of Alzheimer's presenile-senile dementia.

A subcellular fraction enriched in twisted tubules was obtained by differential centrifugation of a homogenate of neurons isolated from areas of the brain with many neurofibrillary tangles from patients with Alzheimer's presenile-senile dementia. A unique protein (molecular weight 50,000 daltons) which does not co-migrate with either of the two tubulin monomers of the major neurofilament protein, both purified from human brain, was found in this subcellular fraction on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Similarly processed tissue from areas of the brain poor in neurofibrillary tangles contained low levels of this new protein. The new protein band could not be seen in control patients.

Alzheimer Disease↗
PubMed1977

Preparation of antisera to neurofilament protein from chicken brain and human sciatic nerve.

Antigens isolated by hydroxyapatite chromatography from human sciatic nerve (SN1 protein) and from 8 M urea extracts of chicken brain were selectively localized by immunofluorescence to neurofibrils in rat and chicken CNS. Absorption of the antisera with SN1 protein, chicken antigen or GFA protein abolished the staining. Antisera raised against antigen isolated with the same procedure from buffer extracts of chicken brain stained both neurofibrils and glial fibrils by immunofluorescence. Neurofibrillary staining was selectively abolished by absorption of the antisera with SN1 protein. Antisera prepared against axonal preparations isolated from bovine white matter only stained astroglia and were thus undistinguishable from anti-GFA sera in this respect. The data suggested that the protein subunits of neurofilament and glial filaments, although difficult to separate in brain extracts by standard biochemical procedures and by subcellular fractionation in bovine white matter, still retain immunological specificity. In addition, the immunological cross reactivity between human and chicken antigens suggested that neurofilaments, as other constituents of the cytoskeleton such as microtubules and actin microfilaments, show a high degree of evolutionary stability.

Animals↗
PubMed1975

Neurofilament and glycogen changes during cold acclimation in the trochlear nucleus of lizards (Sceloporus undulatus).

In lizards (Sceloporus undulatus), long term (13 or 19 weeks) acclimation to an environment of 6 degrees C produces a striking increase in the argyrophilic neurofibrillar network in most large perikarya of the trochlear nucleus. In electron micrographs the cells contain numerous bundles of 10-30 regularly-spaced 90 A neurofilaments. In the cells from warm acclimated animals, a plexus of neurofibrils is seen by light microscopy. The electron micrographs show scattered neurofilaments and fewer, thinner bundles than in the cold. Within the cell bodies of the cold animals, glycogen particles are organized in regional accumulations from which other organelles are excluded except for the bundles of neurofilaments which are distributed throughout the cytoplasm. The aggregations of rough endoplasmic reticulum (RER) are also penetrated by the neurofilament bundles. The increased neurofilamentous network in the cold is not accompanied by obvious changes in the amount or distribution of RER or of microtubules which are present in limited numbers in both conditions. The dendrites of trochlear cells and axon terminals within the nucleus also show a cold induced increase in neurofilaments, as well as in the distinctive accumulations of glycogen particles.

Acclimatization↗
PubMed1979

Neurofibrillary pathology: current status and research perspectives.

The neurofibrils seen in the light microscope are shown, by electron microscopy, to be heterogeneous structures, formed of neurotubules and neurofilaments. A variety of pathological conditions (especially, presenile and senile dementia (are characterized by the presence of neurofibrillary tangles, formed either of paired helical filaments or of single filaments. The morphology, distribution and biochemistry of these various fibrillary structures is reviewed. Particular attention is devoted to the assembly of neurotubules, to the mechanism of action of drugs which prevent assembly, and to possible implications for the experimental induction of neurofibrillary pathology. Of central importance in the arguments is the emphasis on the normal neurofibrillary structures being single forms of pleomorphic proteins. The healthy neuron assembles these proteins into the required form as is necessary for the needs of that neuron. Interference with this process in neuronal cell biology may lead to the deposition of neurofibrillary tangles. On the basis of the morphological and biochemical evidence, several approaches to the experimental study of neurofibrillary pathology are proposed.

Aging↗
PubMed1979

Recent advances of high voltage electron microscopy in biology.

Recent advances in the understanding of the structure of biological material made possible by the high voltage electron microscope are reviewed by briefly summarizing some of the more important results obtained in the past few years. The examination of thick sections of selectively stained specimens has continued to be the most widely used approach and has yielded information on the three-dimensional organization of a range of organelles, including the Golgi apparatus, neurofibrils and the transverse tubular system of striated muscle. The alternative method of studying intact cells prepared by critical-point drying is becoming increasingly popular, and has already made a significant contribution in demonstrating the microtrabecular systems within the cytoplasm of cultured cells.

Animals↗
PubMed1978

Silver impregnation methods for reticulum fibers and reticulin: a re-investigation of their origins and specificity.

Maresch (1905) introduced Bielschowsky's silver impregnation technic for neurofibrils as a stain for reticulum fibers, but emphasized the nonspecificity of such procedures. This lack of specificity has been confirmed repeatedly. Yet, since the 1920's the definition of "reticulin" and studies of its distribution were based solely on silver impregnation technics. The chemical mechanism and specificity of this group of stains is obscure. Application of Gomori's and Wilder's methods to human tissues showed variations of staining patterns with the fixatives and technics employed. Besides reticulum fibers, various other tissue structures, e.g. I bands of striated muscle, fibers in nervous tissues, and model substances, e.g. polysaccharides, egg white, gliadin, were also stained. Deposition of silver compounds on reticulum fibers was limited to an easily removable substance; the remaining collagen component did not bind silver. These histochemical studies indicate that silver impregnation technics for reticulum fibers have no chemical significance and cannot be considered as histochemical technics for "reticulin" or type III collagen.

Connective Tissue Cells↗
PubMed1976

Olfactory esthesioneuroblastoma.

Esthesioneuroblastomas are malignant tumours, usually of slow, invasive growth and low metastatic rate. Skeletal destruction must be assumed to be common, but is often demonstrable only by tomographic sections. Clinically these tumours do not differ from others of the same site, so that the diagnosis has to be based upon the histological appearances. In the light microscope the presence of neurofibrils is considered a specific differential diagnostic factor against other small-cell malignant tumours in this region. There seems to be no basis for a morphological classification into previously described sub-groups, neither according to histogenetic, light, nor ultra-microscopic findings. The general degree of differentiation and the number of mitoses appear to be the main factors of prognostic significance. Combined irradiation and surgical excision is considered the best treatment.

Adult↗
PubMed1975

Fine structural comparison of Ewing's sarcoma with neuroblastoma.

Two cases of Ewing's sarcoma and two neuroblastoma, rosette forming and round cell type, were studied electron microscopically and their fine structures were compared. The neoplastic cells of Ewing's sarcoma were characterized by aggregated glycogen particles in the cytoplasm. They had pseudopod-like cytoplasmic processes having tight junctions, which never contained microtubules or mitochondria. Ewing's sarcoma cells exhibited several stages of cell maturation and some mature cells possessed a large amount of smooth and rough endoplasmic reticulum, large Golgi complexes and numerous phagosomes containing glycogen particles as well as cytoplasmic organelles. The neoplastic cells of neuroblastoma, rosette forming type, were characterized by synaptic junctions and numerous cytoplasmic processes with production of neurites containing microtubules, neurofibrils, mitochondria and a few catecholamine granules. A few cytoplasmic processes containing mitochondria were observed even in the round cell type.

Adolescent↗
PubMed1978

Neuronal cells from chick embryo cerebral hemispheres cultivated on polylysine-coated surfaces.

Dissociated cells from 5- to 12-day-old chick embryo cerebral hemispheres were cultivated in polylysine-coated plastic Petri dishes. The polylysine substrate was observed to be favorable for the growth of neuronal cells, whereas glioblast proliferation was inhibited. The optimal conditions for the production of a predominantly neuronal culture were to use cerebral hemispheres from 7-day-old chick embryos, to dissociate the brain tissue mechanically and to seed the cells at a concentration range between 1.5 and 5 X 10(6) cells/ml. The cultures were observed by phase contrast microscopy. Most cells grew fibers and differentiated into bipolar and multipolar neurons. These neurons were stained by thionine, which demonstrated the presence of Nissl bodies. The silver impregnation revealed the presence of neurofibrils within the nerve fibers. Acetylcholinesterase was found to be present in the neuronal cells, but absent in the glioblasts. Under our culture conditions the neurons survived for 10-12 days. This system should allow further studies on the effects of growth factors on the differentiation of isolated neurons as well as investigations on neuron-glial interrelationship.

Animals↗
PubMed1978

[The role of mastocytes in the development of the adrenergic innervation of the iris].

During the development of the primary adrenerg-plexus in the rat iris presence of mastocytes showing intensive fluorescence can be observed using the method of Falck. After the formation of the primary plexus this phenomenon disappears. By electron microscopy in the early period of the postnatal life authors demonstrated the presence of mastocytes closely related to developing neurofibrils and Schwann-cells. In these mastocytes signs of degranulation were to be observed. On the base of the latter finding one can assume, that substances deliberated from the granules may play a part in the regulation of the development of innervation.

Animals↗
PubMed1976

[The neurobiology of the successive stages of life (author's transl)].

The neurobiological sciences deal with morphological, physiological, biochemical, and pharmacological investigations of neurobiological processes and mechanisms. In addition, they are interested in living organisms as action systems, with their forms of motion, types of behavior, and means of adapting to the environment. The topic "The Neurobiology of the Successive Stages of Life" covers the entire span of life, from the induction of the neural tube to senescence and death, i.e. the sum total of all continuous changes which are described by such terms as development, differentiation, specialization, individuation, functional maturity, and ageing. The following gives a survey from a special neurological-neuroanatomical point of view, it deals with the early development of prenatal activities, forms of movement, and refled differentiation cycles in regard to neurofibrillation, myelination, and cytological-cytoarchetectonic structures. Paul Yakovlev's and Peter Kuzmich Anokhin's interpretations of such selective morphological-functional maturation processes inherent in the system are discussed. There follows a brief survey of varying metabolic systems in close connection with the differentiation of nerve and glia cells and capillarization processes. The subject of early programmed cell death, nerve-cell degeneration, and heterotopia during the development, differentiation, and maturation of the central nervous system leads to a discussion of the likewise selective system-bound processes that take place during senescence of the central nervous system.

Adolescent↗
PubMed1975

[Autoradiographic demonstration of the innervation of the tooth and the periodontium].

The innervation of the tooth and the parodont has been studied by autoradiography of 3H proline, unilaterally injected in the Gasser ganglion of adult cats. The presence of neurofibrils has been observed particularly in predentine and dentine, along the collagen fibers of the periodontal ligament, in the superficial layer of bone and cementum, in the papillar layer of the gingiva and as ultraterminal fibrils in the gingival epithelium.

Animals↗
PubMed1976

Myoclonus in Alzheimer disease. A confusing sign.

Myoclonus in association with dementia of later adult life has been considered almost pathognomonic of Creutzfeldt-Jakob disease. However, myoclonus may also be seen with Alzheimer disease, and when the myoclonus occurs as an early manifestation of Alzheimer disease, distinction from Creutzfeldt-Jakob disease may prove difficult.

Aged↗
PubMed1978

Presenile dementia with Lewy bodies and neurofibrillary tangles.

A 55-year-old man showed progressive mental deterioration over a five-year period along with a syndrome of "normal pressure hydrocephalus." At autopsy the main finding was the presence of two age-related neurocellular changes, the neurofibrillary tangle and the Lewy body, in limbic structures and in the pigmented nuclei of the brain stem. Cortical changes were mild, and senile plaques were not present. Electron microscopy occasionally showed an intimate relationship between the paired helical filaments of the neurofibrillary tangle and Lewy bodies in nerve cell processes in the hypothalamus. The findings suggest a closer relationship between Lewy bodies and neurofibrillary tangles than usually suspected. We also speculate that the presence of one type of age change in the brain may accelerate or predispose to other age changes.

Age Factors↗