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  • 1
    ISSN: 1432-0568
    Keywords: Motoneurons ; Fish ; Fibertypes ; Somatotopy ; Spinal cord ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We investigated the location and size distribution of motoneurons that innervate red, intermediate and white muscle fibers in the axial musculature of the zebrafish (Brachydanio rerio). Motoneurons were identified by retrograde labeling from the respective myotomal compartments with horseradish peroxidase applied either in small polyacrylamide gel fragments or as pure crystals. We found a spatial relationship between the three myotomal muscle fiber types and the corresponding motoneurons. The white motoneurons are grouped in the dorsal part of the motorcolumn, near the central canal. Motoneurons of the red and intermediate muscle are clustered in the ventral part of the motorcolumn. The average position of the red motoneurons is ventral to that of the intermediate motoneurons. Soma sizes are distributed over wide overlapping ranges, spanning from 41 to 352 μm2 for red and intermediate and from 56 to 894 μm2 for white motoneurons. These data are discussed in relation to the recruitment order of myotomal muscle fibers of different types as revealed by electromyographic recordings in fish, and the so called “size principle” for motoneuron recruitment.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 145 (1974), S. 321-342 
    ISSN: 1432-0568
    Keywords: Teleost ; Muscle ; Myotome
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The histological differentiations of myotomes and myosepts in the teleost Brachydanio rerio were studied in relation to function and shape development of the myotomes. The presence of contractile elements, intercellular space, growth by cell proliferation and the collagenous structure of the myosepts were considered as important characteristics. To a certain extent, the first deformations of the somites could be explained with these characteristics. It is suggested that firm attachment of the myosept collagen to the notochord sheath and the asymmetrical growth of the myotomes, might be of importance for the development of the oblique orientation of the muscle fibres. The sequence of the differentiation processes is not the same for all muscle cells. Cells next to the notochord synthetize myofilaments before they become polynuclear, while cells elsewhere in the myotome become polynuclear by fusion before they start to synthetize myofilaments. Some aspects of the histological differentiation of the myotomes in B. rerio were compared with myotome development in the chick, Gallus domesticus.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1365-2559
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Endometrial hyperplasias and carcinomas have been investigated by quantitative microscopical methods. The aim of this study was to develop an objective method of histopathological diagnosis because of the great subjective variability of these endometrial conditions. A total of 79 cases were studied. Only those were included, which, after re-examination of the material by different pathologists, were regarded as mild atypical hyperplasia (38 cases), marked atypical (adenomatous) hyperplasia (11 cases), well and moderately differentiated adenocarcinoma (19 and 11 cases, respectively). There are many significant differences between these four groups. Stereological features contained the most important information, whilst nuclear features were less successful discriminators. The volume percentage of the epithelium and of the glands and the inner surface density of the glands showed the most significant differences between adenomatous hyperplasia and well differentiated carcinoma. On the basis of these findings, a quantitative model is suggested which might give more insight into the development of these abnormalities, assuming a gradual transition from one to another. The great advantage of the quantitative analysis of data over subjective impressions, it that is is objective, and provides consistently reproducible results. The present results may be especially useful when histopathological diagnosis is in doubt. It is concluded that application of quantitative microscopy in the discrimination of endometrial hyperplasia and carcinoma in histopathology is feasible.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1365-2559
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: There are many significant differences, but also considerable overlap between the quantitative histopathological features of mild and marked atypical endometrial hyperplasias and well and moderately differentiated carcinomas, thus preventing its application to individual patient care. To try to overcome this problem, a classification rule for the diagnosis in individual patients, using discriminant analysis has been developed. Utilizing nine quantitative features, all the above four groups can be adequately separated. None of the carcinomas was misclassified as hyperplasia, and only one case of marked atypical hyperplasia was erroneously classified as well differentiated carcinoma, but with a probability of carcinoma 0.75, hyperplasia 0.25. By contrast, the classification probabilities of all the confirmed carcinomas exceeded 0.90. Therefore, using 0.90 as a classification level (‘threshold’), a reliable rule is obtained. A slightly more simple classification rule distinguishes between all the hyperplasias and all the carcinomas. In this way, all the cases of the test set were correctly classified. The classification rules can be used to select patients with benign disease for hormone therapy(Kistner 1973) as an alternative to hysterectomy, and can be programmed in an inexpensive microcomputer. The quantitative techniques are relatively easy, and are capable of being performed in most histopathological laboratories.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 207 (1965), S. 308-308 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Holmstedt1 strongly recommends the use of 'Mipafox' as a selective inhibitor of ChE and of 'BW284c51' as a selective inhibitor of AChE. Pearse2 recommends 'iso-Ompa' (DPDA) and 'BW62c47', respectively, because of the greater distance between the concentrations that cause 50 per cent inhibition ...
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Histochemistry and cell biology 64 (1979), S. 273-278 
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The variation in histochemical SDH-activity at different levels in the same muscle fibre was determined in muscle fibre cross-sections both by visual classification and quantitative determination of the formazan-deposits. This work resulted in a confirmation of the earlier micro-biochemical studies of Spamer and Pette (1977, 1979) and Lowrey et al. (1978) that the activity of enzymes of the citric acid cycle is not homogeneously distributed in a muscle fibre over its entire length. In addition it is shown that the observed variations in histochemical SDH-activity strongly interfere with the visual muscle fibre typing. Some of the possible causes for these variations in histochemical SDH-activity (section-thickness, presence of the motor-end-plate) and the implications of these findings for the relation between histochemical characteristics and functional properties of the muscle fibres are briefly discussed.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Histochemistry and cell biology 64 (1979), S. 263-272 
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Most muscles exhibit a mosaic pattern of staining intensities of their muscle fibres after the histochemical reaction for succinate dehydrogenase (SDH). Visually these muscle fibres are usually classified into three groups: with low (A-fibres), intermediate (B-fibres), and high (C-fibres) enzymatic activity (staining intensity). Cytospectrophotometric methods were employed to investigate whether discrete groups of muscle fibres could be discerned, comparable to those found after the visual classification. The classifications were based on quantitative parameters of the total absorbance per cell and the distribution of the coloured endproduct over the fibre cross area.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1432-2013
    Keywords: Muscle contraction ; Muscle ; Calcium sensitivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Calcium activated isometric force was measured in segments of single muscle fibres of the iliofibularis muscle ofXenopus laevis skinned by freeze-drying. A subdivision in five different fibre types was made, based on the location of the fibres inside the muscle, fibre diameter and a quantitative histochemical assay for succinate dehydrogenase activity. The Ca2+ sensivity was characterized by fitting a Hill curve to the force levels reached at different Ca2+ concentrations. The parametern of this equation indicates the steepness and pK the midpoint of this force-pCa relation. A considerable variability in the Ca2+ sensitivity characteristics was found between different fibres. The parametern varied between 1.1 and 4.2 while pK varied between 5.5 and 6.6. The distribution of the data indicates the presence of three groups with different Ca2+ sensitivity; a group of fibres with low Ca2+ sensitivity but with considerable variation of the steepness of the Ca2+ sensitivity curves (type 1 fibres), an intermediate group (type 2,3 and 4 fibres) with also considerable variation in steepness of the Ca2+ sensitivity curves, in which the lowest values forn are found in type 3 and 4 fibres and a group with high Ca2+ sensitivity and lown containing at least one tonic (type 5) fibre. At sub-saturating Ca2+ concentrations occasionally a transient decrease of the rate of force development was found which resembled the force oscillation reported for some mammalian muscle fibres.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Histochemistry and cell biology 64 (1979), S. 251-262 
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In enzyme histochemistry formazan production can be used as a measure for oxidative enzyme activity. The formazan deposits can be measured quantitatively per cell with a scanning and integrating microspectrophotometer. Optimal conditions are described for the estimation of histochemical succinate dehydrogenase activity in sections of fish bodymusculature and mouse soleus and plantaris muscle. It is shown that when proper measuring conditions are choosen a ditetrazolium salt (TNBT) can be used in quantitative enzyme histochemistry and that the optimal conditions for the histochemical succinate dehydrogenase reaction in muscle fibres of fish and mouse muscle are somewhat different for these two species. The differences in pH, temperature and succinate sensitivity are the most prominent.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Bulletin of mathematical biology 41 (1979), S. 791-802 
    ISSN: 1522-9602
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Mathematics
    Notes: Abstract The purpose of this study is to investigate the relationship between the structure of muscle and its function, especially with regard to the influence of the internal pressure when a muscle contracts. A model is constructed based on the anatomy of muscle. For difference shapes of muscle, but of equal volume, the muscle features (i.e. force exerted etc.) are computed after every contraction step. A function for the internal pressure is also calculated. The internal pressure influences the structure of the muscle which also depends in a certain way upon the function of the muscle.
    Type of Medium: Electronic Resource
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