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W Quitschke

Publications and source records attributed to W Quitschke.

14 recordsLinked to original sources
PubMed1990

Keratin 8 of simple epithelia is expressed in glia of the goldfish nervous system.

The intermediate filament protein composition in glial cells of goldfish optic nerve differs from that found in glial cells of the goldfish spinal cord and brain. Brain and spinal cord glial cells contain glial fibrillary acidic protein (GFAP), whereas glial cells in the optic nerve contain ON3. The ON3 protein of the goldfish optic nerve was recently identified as the goldfish equivalent to the mammalian type II keratin 8 protein. In addition to the ON3 protein, the goldfish optic nerve also contains a 48-kDa protein. Immunoblotting experiments suggest that this protein is equivalent to the mammalian type I keratin 18 protein, which typically pairs with keratin 8 to form filaments. We show that these proteins are not specific to the optic nerve. The ON3 and 48-kDa proteins of the goldfish optic nerve share common antigenic properties with the predominant keratin pair expressed in the goldfish liver. These proteins are also expressed at low levels in the goldfish brain and spinal cord. In addition RNase protection assays and Northern blots indicate that the mRNA for the ON3 protein in optic nerve is identical to the message found in other goldfish tissues. The expression of ON3 was also examined in cultured glial cells from goldfish spinal cord and optic nerve and cultured fibroblast cells. Analysis of intermediate filament protein expression in cultured glial cells taken from goldfish spinal cord demonstrated the absence of GFAP in these cells and the expression of ON3. This protein was also the predominant intermediate filament protein of cultured optic nerve glial cells and fibroblasts. The differences in the expression of intermediate filament proteins in mammals and lower vertebrates are discussed. In addition, we discuss how the expression of a simple epithelial keratin pair in glial cells of the goldfish optic nerve may be associated with this system's capacity for continuous growth and regeneration.

Animals↗
PubMed1988

Approximately 1 kilobase of sequence 5' to the two myosin light-chain 1f/3f gene cap sites is sufficient for differentiation-dependent expression.

Approximately 1 kilobase of genomic DNA from the chicken fast myosin light-chain 1f/3f gene 5' to the transcriptional start sites for each light-chain mRNA was sufficient for differentiation-dependent, tissue-restricted expression. This was determined in primary chick myoblast cultures transfected with the chloramphenicol acetyltransferase (CAT) expression vector p8CAT containing these 5'-flanking sequences. The expression of CAT activity from both light-chain promoters was 10- to 20-fold higher in differentiated myotubes than in fibroblasts or myoblasts grown in bromodeoxyuridine. In contrast, the beta-actin and Rous sarcoma virus promoters joined to the CAT gene were expressed equally in all cell backgrounds tested. Even though the relative timing of light-chain 1f and 3f expression was altered, tissue-restricted, differentiation-dependent expression of the light-chain mRNAs was maintained with these 5' cis-acting sequence elements.

Acetyltransferases↗
PubMed1986

Immunohistochemical localization of intermediate filament proteins of neuronal and nonneuronal origin in the goldfish optic nerve: specific molecular markers for optic nerve structures.

The predominant proteins (58K) of the intermediate filament complex in the goldfish visual pathway consist of a series of isoelectric variants. Previous biochemical studies have shown that proteins ON1 and ON2 are of neuronal origin, whereas ON3 and ON4 are of nonneuronal origin. Polyclonal antibodies, purified by affinity chromatography, that are specific for ON1 and ON2 or ON3 and ON4 have been used to localize histologically the ON proteins within the normal and crushed optic nerve. Anti-ON1/ON2 antiserum presented a pattern consistent with intraaxonal staining. A nonneuronal staining pattern was observed with anti-ON3/ON4 antiserum. The two patterns were distinct from and complementary to each other. The data suggest that ON3 and ON4 represent a novel glial fibrillary acidic protein. The results are discussed in terms of the function of these proteins in development, plasticity, and regeneration.

Animals↗
PubMed1986

Homology and diversity between intermediate filament proteins of neuronal and nonneuronal origin in goldfish optic nerve.

The predominant intermediate filament proteins of the goldfish optic nerve have molecular weights of 58K. They can be separated into a series of four major isoelectric variants of neuronal (ON1 and ON2) and nonneuronal (ON3 and ON4) origin. The extent of homology between the goldfish 58K intermediate filament proteins themselves and to rat optic nerve vimentin and glial fibrillary acidic protein (GFAP) was investigated. Unlabeled and [32P]orthophosphate-labeled proteins were subjected to partial hydrolysis by V8 protease, chymotrypsin, and CNBr. The results show that the goldfish intermediate filament proteins share with vimentin and GFAP a 40K chymotrypsin-resistant core fragment. Phosphorylated moieties appear to be located outside the core region since they are preferentially cleaved off by chymotrypsin and not found associated with the 40K core. In addition, the goldfish ON proteins contain the antigenic site within the core that is common to most intermediate filaments. V8 or CNBr digestion indicates that many fragments that are common to ON1 and ON2 are clearly distinct from fragments that are common to ON3 and ON4. In addition, structural variability is observed between the goldfish intermediate filament proteins and vimentin and GFAP. The results are discussed in terms of intermediate filament structure and their possible role in nerve growth.

Animals↗
PubMed1986

62K proteins constitute the major neurofilament proteins in the frog optic nerve.

The frog optic nerve contains a major group of proteins at a molecular weight of 62K. These proteins are insoluble in nonionic detergents, reactive with a general antibody to intermediate filament proteins, and not labeled by ex vivo incubations of optic nerve. They were therefore considered neurofilament proteins. Axonal transport and enucleation studies were performed to characterize further the origin of these proteins. The results show that the 62K proteins are transported into the optic nerve at a very slow rate (0.1 mm/day). After enucleation, these proteins are substantially reduced in concentration to 20% of the control value at 13 weeks. The predominant neurofilament proteins of the frog optic nerve are 62K in molecular weight. These results are discussed in terms of the anatomy of the frog optic nerve and also contrasted to findings obtained for the goldfish optic nerve.

Animals↗
PubMed1985

Variable expression of intermediate filament proteins during embryonic development of human optic nerve.

The intermediate filament protein composition of human optic nerve and tract was analyzed by two-dimensional gel electrophoresis. Optic nerves were analyzed at 15, 19, 22, and 24 weeks of embryonic development and the results were compared with the composition of adult optic nerve. The optic tract was analyzed at the later stages of development. The proteins were visualized by Coomassie blue staining and immunoblotting with specific antibodies to glial fibrillary acidic protein (GFAP) and vimentin. The 70K and 150K neurofilament proteins were first observed at 24 weeks. At 15 weeks of development, only trace amounts of GFAP were observed and vimentin was the predominant intermediate filament protein. In contrast, there was more than twice as much GFAP as vimentin in the adult optic nerve. The results also showed that the ratio of GFAP to vimentin is higher in the optic tract than in the optic nerve during development, whereas in adult tissue, the ratio is the same for the two regions. In pathological situations with axonal dropout, a complete loss of neurofilament proteins was observed. The amounts of both GFAP and vimentin were the same for both the normal and involved optic nerve. These results are discussed in terms of the development of the optic nerve.

Glial Fibrillary Acidic Protein↗
PubMed1985

Survey of intermediate filament proteins in optic nerve and spinal cord: evidence for differential expression.

The distribution of intermediate filament proteins in optic nerve and spinal cord from rat, hamster, goldfish, frog, and newt were analyzed by two-dimensional gel electrophoresis. General as well as specific monoclonal and polyclonal antibodies were reacted against putative intermediate filament proteins. In vitro incubations of excised optic nerve in the presence of [35S]methionine distinguished between neuronal and nonneuronal intermediate filament proteins. The proteins of the intermediate filament complex in the two tissues for rat and hamster were similar. The typical neurofilament triplet and glial fibrillary acidic protein (GFAP) were observed. Vimentin was more concentrated in the optic nerve than in the spinal cord. The goldfish, newt, and frog contained neurofilament proteins in the 145-150K range and in the 70-85K range. In addition, predominant neurofilament proteins in the 58-62K molecular-weight range were found in all three species. In contrast to mammalian species, the goldfish, newt, and frog displayed extensive heterogeneity between optic nerve and spinal cord in the expression of both neuronal and nonneuronal intermediate filament proteins. The distinctive presence of low-molecular-weight intermediate filament proteins and their high concentration in the optic nerve and spinal cord of these nonmammalian vertebrates is discussed in terms of neuronal development and regeneration.

Amphibians↗
PubMed1984

58,000 dalton intermediate filament proteins of neuronal and nonneuronal origin in the goldfish visual pathway.

A group of proteins in the goldfish optic nerve with a molecular weight of 58K daltons was analyzed by two-dimensional gel electrophoresis. Results show that the proteins are differentially phosphorylated and found exclusively in a cytoskeletal-enriched fraction. The proteins from this fraction can be reconstituted into typical intermediate filament structures, as shown by electron microscopy. Two components which are of neuronal origin are transported within the slow phase of transport. The 58K proteins are the most abundant proteins in the optic nerve, and they are distinct from actin and tubulin. It was concluded that they are intermediate filament proteins. Cytoskeletal preparations of rat spinal cord, rat optic nerve, and goldfish optic nerve were compared by one-dimensional gel electrophoresis. The rat spinal cord contains glial fibrillary acidic protein (GFAP), and the rat optic nerve contains vimentin and GFAP, in addition to the neurofilament triplet. A typical mammalian neurofilament triplet is not detected in the goldfish optic nerve, while the major cytoskeletal constituent is a 58K band which coelectrophoreses with vimentin in the rat optic nerve by one-dimensional gel electrophoresis.

Animals↗
PubMed1983

In vitro protein synthesis in the goldfish retinotectal pathway during regeneration: evidence for specific axonal proteins of retinal origin in the optic nerve.

Four proteins with molecular weights of 58,000 can be separated as a linear array by two-dimensional gel electrophoresis. They are highly concentrated in the goldfish optic nerve and are designated as ON1, ON2, ON3, and ON4. Proteins ON1 and ON2 are undetectable in the optic nerve after disconnection and their concentration is gradually restored during regeneration. In vitro incubations of retinas, optic nerves, or tecta in the presence of [35S]methionine indicate that proteins ON1 and ON2 are of retinal origin. The labeling rate of these proteins in the retina increases fourfold after optic nerve crush whereas the overall labeling rate in the retina remains largely constant. Their synthesis cannot be detected in tissues devoid of retinal ganglion cells. This is consistent with the view that ON1 and ON2 are synthesized by retinal ganglion cells and are consequently of neuronal origin in the optic nerve. In contrast, similar experiments indicate that ON3 and ON4 are of nonneuronal origin. They are synthesized in the optic nerve in the absence of retinal ganglion cells.

Animals↗
PubMed1981

Glutamic acid binding in goldfish brain and denervated optic tectum.

The binding of L-glutamic acid to goldfish brain membranes and changes in tectal binding following optic nerve denervation and regeneration were investigated. Saturable, reversible, and specific binding occurred to sodium-free washed membranes from goldfish brain at a single population of sites having an apparent Kd of 3.4 microM and a capacity of 10 pM/mg original tissue. Binding was enriched in crude synaptosomal (P2) subcellular fractions. There was a 10-fold regional variation in the concentration of binding sites. In pharmacological studies protection constants (Kp) (the concentration which resulted in a 50% inhibition of binding) ranged from 4 microM for glutamate to greater than 10 mM for GABA. Following eye removal, the total number of tectal glutamic acid binding sites was stable for 4 days, followed by a rapid loss in binding, reaching 40% of control at 24 days. After optic nerve crush and optic nerve regeneration, the number and concentration of binding sites was not different from control. The relationship between glutamate, nicotinic, and muscarinic receptor sites in the retinotectal pathway is discussed.

Animals↗
PubMed1980

Electrophoretic analysis of specific proteins in the regenerating goldfish retinotectal pathway.

Proteins in the goldfish retinotectal pathway were analyzed by 2-D gel electrophoresis, under conditions of optic nerve crush or eye removal. A specific cluster of proteins was detected, consisting of 4 components, all of which are highly concentrated in the intact optic nerve. Two components were not detectable in non-visual areas of the goldfish brain. The total cluster was diminished by about 80% in the denervated optic tectum, and its level was restored during optic nerve regeneration. These data were interpreted as evidence for visual system-specific proteins in the goldfish retinotectal pathway.

Animals↗
PubMed1980

Analysis of protein levels and synthesis after learning in the split-brain pigeon.

A series of experiments were performed to study the effects of learning upon proteins in the split-brain pigeon. With this preparation, one side of the brain was trained in a color discrimination task while the other side served as a naive control. Proteins from both sides of the brain were separated by one- and two-dimensional polyacrylamide gel electrophoresis and analyzed to measure protein levels or protein synthesis. No differences were found between trained and naive telencephalic hemispheres or between trained and naive optic lobes in the steady-state protein levels or in protein synthesis.

Animals↗
PubMedDate not supplied

Alois Alzheimer, neuroscientist (1864-1915)

Little is known about the person behind the eponymous dementia, Alois Alzheimer. We wished to study his life and contributions to the field of neuroscience. All cited articles about Alzheimer by his contemporaries and selected correspondence by him was translated from German. Additional personal information was obtained from his granddaughter. Alois Alzheimer made seminal contributions to the field of neuroscience, not only through his own research but also through the numerous scientists and physicians whom he taught. His contributions made a lasting impact not only in the area of Alzheimer disease but also other aspects of brain disease. In addition, he emerges as a complex person who coped successfully with numerous personal and career-related dilemmas that remain relevant in the academic environment today.

Germany↗