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  • 1
    Electronic Resource
    Electronic Resource
    The Coupling of 4-Methoxy-2-naphthylamine with Diazotized Aminodiazo Thioethers*,1 (1965)
    s.l. : American Chemical Society
    The @journal of organic chemistry 30 (1965), S. 1779-1781 
    Details
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/jo01017a016
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  • 2
    Electronic Resource
    Electronic Resource
    Design and Synthesis of Thiolesters for the Histochemical Demonstration of Esterase and Lipase via the Formation of Osmiophilic Diazo Thioethers1 (1966)
    s.l. : American Chemical Society
    Journal of medicinal chemistry 9 (1966), S. 288-291 
    Details
    ISSN: 1520-4804
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/jm00321a005
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  • 3
    Electronic Resource
    Electronic Resource
    The demonstration of arylsulfatases with 4-nitro-1,2-benzenediol mono(hydrogen sulfate) by the formation of osmium Blacks at the sites of copper capture (1975)
    Springer
    Histochemistry and cell biology 41 (1975), S. 207-225 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A new method is described for the direct cytochemical demonstration of lysosomal arylsulfatases utilizing a synthetic substrate, 4-nitro-1,2-benzenediol mono)hydrogen sulfate), and a copper capture reaction. A small amount of Hatchett's brown (cupric ferrocyanide, Cu2Fe(CN)6·7 H2O) formed at the subcellular sites of copper capture is then utilized as a heterogeneous catalyst to effect the oxidative polymerization of 3,3′-diaminobenzidine which results in the formation of an insoluble, highly colored osmiophilic indamine polymer at the sites of enzymatic activity. The reaction product even at this stage prior to osmication is highly visible. It is readily seen with a light microscope in 50 μm sections of fixed tissues prepared with a mechanical chopper or in 10 micron cryostat sections treated for arylsulfatase activity. Upon osmication, an electron-opaque osmium black is formed which is much less soluble than the products of either the lead or barium capture reactions currently used for the demonstration of arylsulfatase with the electron microscope. The selection of areas of plastic-embedded tissues for ultrathin sectioning is facilitated by the ready visibility of these osmium black end products on 1–2 μm plastic sections which can be studied with the light microscope. This method gives permanent specimens demonstrating arylsulfatases A or B in lysosomes and autophagic vacuoles. In addition, enzyme activity is seen occasionally in the Golgi region or lamellae of certain cells believed to be elaborating sulfated products. In these instances, it may be demonstrating sulfotransferase activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00497684
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  • 4
    Electronic Resource
    Electronic Resource
    Cytochemical correlates of structural sexual dimorphism in glandular tissues of the mouse (1975)
    Springer
    Histochemistry and cell biology 44 (1975), S. 225-244 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The parietal epithelium of Bowman's capsule has been analyzed by enzyme cytochemistry in kidneys of mice (C57BL/6J) from birth to 50 days of age. There is a greater tendency for cells in the central portions of the capsular crescent to be cuboidal in postpubertal males than in pre-pubertal mice of either sex or in post-pubertal females where they are generally squamous; moreover, these heightened capsular cells have a distinct microvillous border. Cytochemical procedures were selected which might confirm the morphological suggestion that the cuboidal parietal epithelium possesses an absorptive capacity. The oxidoreductase activity of the mitochondria of the cuboidal cells of this layer is comparable to that of the columnar cells of the proximal convoluted tubule. The cytochrome oxidase activity of the mitochondria in both of these segments of the nephron is intense. This is in sharp contrast to the unreactive mitochondria in the squamous cells of the parietal epithelium. Furthermore, a striking heterogeneity in the degree of cytochrome oxidase activity is evident in the mitochondria of the cuboidal parietal cells as well as in the cells of the proximal tubules. In the former cells, active mitochondria were generally found near microvilli at the apical ends and in the areas of the basal infoldings whereas those in a central position were more frequently unreactive. The brush border of the cuboidal capsular epithelium had prominent alkaline phosphatase and aminopeptidase activities as has previously been observed in other brush borders. Functional capacity corresponding to the morphological and cytochemical specialization of the cuboidal capsular cells was demonstrated by their uptake of horseradish peroxidase. This exogenous protein tracer could be seen in apical vacuoles and phagosomes in the cuboidal parital epithelium. The cytochemical resemblance of the cells of this epithelium to those of the proximal convoluted tubules suggests a similar involvement in resorption and perhaps in active transport. A possible relationship of this differentiation of the capsular epithelium to the proteinuria normal for adult male mice is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00491493
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  • 5
    Electronic Resource
    Electronic Resource
    New methods for the demonstration of lysosomal hydrolases by the formation of osmium blacks (1972)
    Springer
    Histochemistry and cell biology 30 (1972), S. 201-214 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Methods are described for the direct cytochemical demonstration of the enzymes nonspecific esterase and acid phosphatase based on synthetic substrates which initially deposit Hatchett's brown (cupric ferrocyanide, Cu2Fe(CN)6·7 H2O) at their subcellular sites. The small amounts of Hatchett's brown deposited as a result of the enzyme's activity may be intensified by bridging to osmium through thiocarbohydrazide. Alternatively, even greater amplification of the sites of activity may be attained by utilizing the Hatchett's brown as a catalyst to effect the oxidative coupling of 3,3′-diaminobenzidine resulting in the formation of an osmiophilic indamine-type polymer. One of the major advantages of this new approach is that it permits the study of acid hydrolase localization without lead in the incubation medium. Studies were performed with these methods having identical incubation media except for synthetic substrate in many different cell types and tissues. They verify a frequent nonlysosomal localization for acid phosphatase and the heterogeneity of lysosomes and lysosomal populations with respect to hydrolase content. These methods give information obtained by direct cytochemical observation an advantage not previously held, in comparison with information from cell-fractionation cytochemical or biochemical studies. Initial studies with these methods on many tissues reinforce previous suggestions of the involvement of acid hydrolases in extralysosomal sites in subcellulur anabolic processes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00277592
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  • 6
    Electronic Resource
    Electronic Resource
    The demonstration of cholinesterases by the formation of osmium blacks at the sites of Hatchett's brown (1973)
    Springer
    Histochemistry and cell biology 37 (1973), S. 223-242 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Small amounts of Hatchett's brown (cupric ferrocyanide, Cu2Fe(CN)6·7H2O), deposited at the sites of cholinesterase activity in tissues by the procedure of Karnovsky and Roots (1964), may be enhanced by bridging to osmium through thiocarbohydrazide (TCH). Alternatively, amplification of the deposits may be attained by utilizing the cupric ferrocyanide as a catalyst to effect the oxidative coupling of 3,3′-diaminobenzidine (DAB). The resulting intensely colored osmiophilic polymer is more visible and after osmication, is electron opaque. With these procedures, the light microscope preparations are more permanent than with the Gomori modification of the Koelle and Friedenwald procedure. One of the major advantages of this method is that thick serial plastic sections (1–2 μm) may be taken and readily studied by light microscopy until the required enzymatically stained areas appear. Thus the selection of areas for ultrathin sectioning is facilitated; enzymatically stained structures usually difficult to locate, such as intraepithelial nerve endings, are readily found. The intensification procedures permit shorter incubation times at lower temperatures. This results in diminished tendency of the original amorphous, gel-like Hatchett's brown deposits to coalesce into relatively large cubic crystals. Immediate rinsing of the tissues after the formation of Hatchett's brown with a 0.1 M, pH 7.2, tris (hydroxymethyl)aminomethane (TRIS) buffer prior to intensification with either TCH or DAB was found effective in eliminating some of the smaller background deposits after the longer incubations. Studies in developing mice with an hereditary sensory neuropathy showed severe depletion of acetylcholinesterase activity concomitant with the loss of sensory endings from the rugae of hard palate, confirming the peripheral nature of the neuropathy. High levels of acetylcholinesterase found associated with afferent trigeminal components, especially sensory endings containing clear vesicles, suggest that they may be cholinoceptive.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00304184
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  • 7
    Electronic Resource
    Electronic Resource
    Tissue fixation and osmium black formation with nonvolatile octavalent osmium compounds (1976)
    Springer
    Histochemistry and cell biology 49 (1976), S. 263-291 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Several compounds of osmiumVIII, including potassium osmiamate and coordination complexes of OsO4 with ammonia and various heterocyclic nitrogen compounds, have been synthesized and characterized. They have also been evaluated as substitutes for OsO4 in postfixation of biological specimens and in light and electron microscopic cytochemical methods resulting in osmium black formation. The most useful of these osmic compounds, a molecular addition complex of hexamethylenetetramine (methenamine) with OsO4, has a negligible vapor pressure of OsO4. It has the molecular formula C6H12N4.2OsO4 and has been designated osmeth. Although it has only limited solubility, aqueous solutions of the compound (or of OsO4) can be rapidly prepared by dissolution in a minimal amount of dimethylformamide and subsequent dilution with distilled water or buffer. Although stable in the solid state, the complex in solution undergoes partial dissociation releasing OsO4, and the odor of OsO4 becomes apparent. Such solutions of osmeth are (∼0.25%) considerably less concentrated with respect to OsO4 than solutions (1–2%) ordinarily employed for ultrastructural preservation or in cytochemical studies. Osmeth has limited value for postosmication after glutaraldehyde fixation because the generation (release) of OsO4 appears to be slow. Adequate osmication of tissue blocks exists only at the surface, but effective osmication can be achieved throughout tissue sections. In cytochemical reactions resulting in the formation of osmium blacks, the osmeth solutions are as effective as OsO4 solutions of equivalent concentrations. Our findings indicate that OsO4 solutions of less than 1% may be satisfactorily utilized in many cytochemical studies. Osmeth is safer and more convenient to handle than OsO4 because small amounts may be solubilized as needed. It should be considered as a substitute for OsO4 in ultrastructural cytochemistry.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00496131
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  • 8
    Electronic Resource
    Electronic Resource
    Ultrastructural demonstration of acetylcholinesterase activity of motor endplates via osmiophilic diazothioethers (1967)
    Springer
    Histochemistry and cell biology 11 (1967), S. 1-12 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructural chemical localization of acetylcholinesterase of motor endplates of rat intercostal muscle has been studied with three new esterase substrates. These substrates, although not specific for acetylcholinesterase, have differential affinities for various types of esterases; two of them (NTA and TAB) are hydrolyzed preferentially by acetyl esterase enzymes, and the third (TPB) is a propionic acid ester and is hydrolyzed preferentially by pseudocholinesterase and other esterases. The end-product of the enzymatic reaction is converted to a diazothioether (droplet form) and upon osmication this is converted to a coordination polymer of osmium which has ideal properties for electron microscopy. Although this study supports previous observations that enzymatic activity can be found primarily on the post-synaptic membranes of the motor endplate, no enzymatic activity was noted on the pre-synaptic membrane, within the synaptic cleft, or on the basement membrane unless incubation was prolonged, resulting in overstaining. Neither was enzyme activity seen on membrane-free ribosomes and the ribosome-studded sarcoplasmic reticulum. Axonal vesicles also failed to exhibit enzymatic activity which had been noted with the method using thiolacetic acid and lead. A correlation of esterase activity with ultrastructural localization, using the substrate TPB, suggests that a “buffer” zone of nonspecific esterase activity is present beneath the subneural apparatus which limits the aberrant, accidental, or abnormal distribution of acetylcholine within a clearly defined area of sarcoplasm in the vicinity of the motor endplate of the muscle fiber.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00326608
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  • 9
    Electronic Resource
    Electronic Resource
    Acid phosphatase in the Golgi apparatus of cells forming extracellular matrix of hard tissues (1973)
    Springer
    Histochemistry and cell biology 35 (1973), S. 39-50 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Histochemical studies using cryostat sections of fixed rodent fetal and newborn tissues indicated that acid phosphatase (APase) staining of the Golgi apparatus (GA) of cells secreting matrix for hard tissue formation was a general phenomenon. The enzyme was chiefly observed in the GA of tall secretory ameloblasts involved in enamel formation and in the GA of odontoblasts forming dentine; lysosome-like granules reactive for this enzyme were also observed in these cells. Activity was also intense in the GA and lysosomes of osteoblasts involved in intramembranous and endochondral bone formation. High levels of APase in the GA of extracellular matrix-forming cells appeared to correlate with secretory activity. The GA of most other cells, even chondroblasts forming cartilage matrix, had much less marked APase activity. Contrary to previous suggestions, it appears that APase may have a more direct role in osteogenesis than the osteolytic or resorptive action usually cited.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00303663
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  • 10
    Electronic Resource
    Electronic Resource
    The demonstration of dehydrogenases and monoamine oxidase by the formation of osmium blacks at the sites of Hatchett's brown (1972)
    Springer
    Histochemistry and cell biology 33 (1972), S. 205-230 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Methods are described for the direct cytochemical demonstration by light or electron microscopy of several mitochondrial dehydrogenase enzymes and monoamine oxidase using ferricyanide as an artificial electron acceptor. Hatchett's brown, cupric ferrocyanide, is the primary reaction product produced at the sites of mitochondrial oxidative enzymes in briefly fixed tissues by the histochemical incubation. After post-fixation, the cupric ferrocyanide is utilized as a catalyst to effect the oxidative polymerization of 3,3′-diaminobenzidine (DAB), resulting in an amplification of the original deposits. Upon osmication an osmium black end-product, which is ideal for light or electron microscopy, is produced at the tissue sites of the flavoprotein enzyme. Dimethylsulfoxide (DMSO) in concentrations of approximately 14%, was found to mediate electron transfer from cysteine as well as from many reduced carriers to artificial acceptors. In these reactions DMSO, because of its basic oxygen, is an excellent acceptor for hydrogen bonding and can substitute for water in solvation phenomena. Because of its low dielectric constant, it acts to facilitate electron transfer. With these new procedures for monoamine oxidase (MAO), lactic dehydrogenase (LDH), NADH dehydrogenase, and NADPH dehydrogenase, a heterogeneity of mitochondria with respect to oxidative enzymes was noted. In addition, differential sensitivities of the enzymes to fixatives was noted. There appeared to be an inverse relationship of the localization of LDH and MAO in certain areas of gray and white matter of medulla oblongata, cerebellum and sensory ganglia. This could be due to the heterogeneity of mitochondrial populations noted with respect to these enzymes. The strong LDH activity exclusively in mitochondria in different types of fixed cells and its absence from unfixed tissues confirms a mitochondrial localization for the enzyme. These findings suggest that more caution is needed in the interpretation of results from cellfractionation cytochemical and biochemical studies; moreover, results with non-disruptive direct visual histochemical and cytochemical methods may be valid, even if they do not conform to results from use of the former indirect methods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00274235
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