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  • 1
    Electronic Resource
    Electronic Resource
    Middle-ear development: II. Morphometric changes in the conducting apparatus of the chick (1992)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 212 (1992), S. 257-267 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The ontogeny of various middle-ear structures was examined in 11 groups of chicks between 10 days embryonic and adult. Measurements of the tympanic membrane surface area and height, columella length, and that of the columella footplate, annular ligament, and oval window area were obtained using video micrographs and computer digitization techniques. The oval window matures first at 53 days post-hatching, whereas the columella achieves adult size at 74 days. The tympanic membrane surface area is the last middle-ear variable studied to reach adult size (79 days post-hatch). The columella increases its length from 0.63 mm (10 days embryonic) to 2.73 mm in the adult. The tympanic membrane area expands by 280% whereas the columellar footplate area increases by 11x. As a result, the pressure amplification of the middle ear due to the tympanic membrane/columellar footplate area ratio improves by over 400%. These data further contribute to our understanding of the functional development of the middle ear. © 1992 Wiley-Liss, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052120305
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  • 2
    Electronic Resource
    Electronic Resource
    Middle-ear development VI: Structural maturation of the rat conducting apparatus (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 239 (1994), S. 475-484 
    Details
    ISSN: 0003-276X
    Keywords: Middle ear ; Auditory ; Hearing development ; Ossicles ; Tympanic membrane ; Rat (Long Evans strain) ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Background: The contribution of middle-ear development to the overall development of hearing has not been explored in great detail. This presentation describes the maturation of conductive elements in the rat middle ear, and provides the basis on which future studies of middle-ear functional development will follow.Methods: The middle-ear apparatus was examined at nine different ages (between 1 and 80 days postpartum) in Long Evans rats. At each age elements of the conducting apparatus were observed with either light or scanning electron microscopy (SEM), and quantitative measurements were made from video enhanced photomicrographs. Tympanic membrane area and cone depth, the length of the malleus and incus arms, ossicular weight, stapes foot plate and oval window areas, and bulla volume were all measured. Development of the area and lever ratios were derived from these measurements. The data were fitted to exponential equations and the time in days required to reach 90% of the adult level determined.Results: The pars tensa achieved 90% of total area by 17 days. The oval window achieved the 90% criterion by 13 days, while the area ratio was within 10% of its adult size by 8 days. The ossicles took between 26 and 34 days, while bulla volume took 59 days to reach the 90% level.Conclusions: Middle-ear growth was very orderly and systematic in the data reported. When maturation of the area ratio was considered against development of the endocochlear potential or the round window compound action potential, it was clear that the growth of this important aspect of the middle ear preceded the onset of cochlear function. © 1994 Wiley-Liss, Inc.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092390413
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  • 3
    Electronic Resource
    Electronic Resource
    Changes in the morphology and phosphatase cytochemistry of the Golgi region of hepatocytes during the acute phase response to inflammation (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 241 (1995), S. 439-450 
    Details
    ISSN: 0003-276X
    Keywords: Golgi ; TGN ; Inflammation ; Acute phase response ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Background: During the acute phase response to inflammation, the Golgi apparatus of rat hepatocytes processes an increased quantity of glycoproteins, in the form of acute phase reactants.Methods: The compartmental organization of the hepatocyte Golgi of control and 24 hour inflamed rats was studied, using transmission electron microscopic techniques, including cytochemistry, to detect nicotinamide adenine dinucleotide phosphatase (NADPase), thiamine pyrophosphatase (TPPase), and cytidine monophosphatase (CMPase) activity.Results: In inflamed rats, individual Golgi stacks were enlarged, but retained their organization into four compartments:1) a phosphatase negative, perforated cis-element, 2) two mid-saccules which sometimes were positive for NADPase, 3) one or occasionally two NADPase and TPPase positive trans-saccules, and 4) a tubulovesicular trans-Golgi network (TGN) which was NADPase reactive and contained a spotty TPPase reaction product. Two of these compartments were noticably altered in response to inflammation. The two mid-saccules were consistently and uniformly dilated. The TGN was altered to the point of being difficult to recognize and had acquired CMPase reactivity. In control rats the TGN consisted of anastomosing tubules forming cage-like structures; secretory granules containing lipoprotein particles pinched off from these. In inflamed rats, most of the cage-like TGN structures had been replaced with an extensive vesicular syncytium which produced secretory granules with a granulofilamentous content.Conclusions: In hepatocytes from inflamed rats an apparent switch had occured in the type of secretory material processed by the Golgi apparatus. Furthermore, the inflammation-induced increase in the size of individual Golgi stacks apparently was not due to a parallel increase in size of all Golgi saccules. Rather, saccules within given Golgi compartments responded in a characteristic and specific manner to the increase in glycoprotein processing that occurs during inflammation. © 1995 Wiley-Liss, Inc.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092410402
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  • 4
    Electronic Resource
    Electronic Resource
    Cytoarchitecture of the substantia nigra pars lateralis in the opossum (Didelphis virginiana): A correlated light and electron microscopic study (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 241 (1995), S. 563-578 
    Details
    ISSN: 0003-276X
    Keywords: Substantia nigra ; Basal ganglia ; Cytoarchitecture ; Light microscopy ; Electron microscopy ; Opossum ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Background: The substantia nigra has been divided into three subdivisions. However, the cytoarchitecture of one of these subdivisions, the pars lateralis (SNI), has not been previously examined in detail at the light and electron microscopic levels in any species. In the adult opossum, the three nigral subdivisions can be easily distinguished as distinct, rostrocaudally oriented cell groups separated by neuron-free zones. Thus it was possible to determine the boundaries of the SNI unambiguously. This report covers the results of an examination of the morphology and organization of the SNI in the opossum.Methods: Material from 13 opossums was used for this study. Eight of the animals had been previously stained for Nissl substance (n=4) or impregnated by the Golgi technique (n=4). The remaining five animals were prepared for electron microscopic studies using standard procedures.Results: Two cell types were identified on the basis of morphological differences, small and medium-large neurons. Small neurons (10-18 μm long axis) have large nuclei with moderate amounts of heterochromatin and a thin rim of cytoplasm. They have long (up to 500 μm), spine-free dendrites. Medium-large neurons (18-54 μm long axis) have rounded nuclei with electron-lucent nucleoplasm. Few indentations of the nuclear envelope were observed. The surrounding cytoplasm has dense arrays of organelles. Nissl bodies are particularly prominent in the form of pyramids with their bases at juxtanuclear positions and their apices directed toward emerging dendrites. Dendrites of medium-large neurons are long (some〉1 mm in length), are primarily oriented in the frontal plane, and extend along the dorsal surface of or into the cerebral peduncle. Some cells have dendrites that are moderately spinous, whereas other neurons possess sparsely spinous dendrites. Relatively few synaptic profiles are observed to contact somata and proximal dendrites.Conclusion: This report provides added morphological support for the idea that the SNI is a distinct subdivision of the substantia nigra, a distinction previously made on the basis of the physiologically characterized relationship between the lateral substantia nigra and orienting behaviors and seizure-related function. © 1995 Wiley-Liss, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092410414
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  • 5
    Electronic Resource
    Electronic Resource
    Nuclear cholesterol content and nucleoside triphosphatase activity are altered in the JCR:LA-cp corpulent rat (1996)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 63 (1996), S. 349-357 
    Details
    ISSN: 0730-2312
    Keywords: hypercholesterolemia ; nuclear membrane ; NTPase ; hyperlipidemia ; obesity ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: A nuclear pore complex-associated nucleoside triphosphatase (NTPase) activity is believed to provide energy for nuclear export of poly(A)+ mRNA. This study was initiated to determine if nuclear membrane lipid composition is altered during chronic hyperlipidemia, and what effect this has on NTPase activity. The JCR:LA-cp corpulent rat model is characterized by severe hypertriglyceridemia and moderate hypercholesterolemia, and thus represents an ideal animal model in which to study nuclear cholesterol and NTPase activity. NTPase activity was markedly increased in purified hepatic nuclei from corpulent female JCR:LA-cp rats in comparison to lean control rats as a function of assay time, [GTP], [ATP], and [Mg2+]. Nuclear membrane cholesterol and phospholipid content were significantly elevated in the corpulent animals. Nuclei of corpulent animals were less resistant to salt-induced lysis than nuclei of lean animals, suggesting a change in relative membrane integrity. Together, these results indicate that altered lipid metabolism in a genetic corpulent animal model can lead to changes in nuclear membrane lipid composition, which in turn may alter nuclear membrane NTPase activity and integrity. © 1996 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Intratendinous ossification in birds: A review (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 226 (1995), S. 47-77 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Intratendinous ossification (tenostosis; Tendo ossificans) is a distinct structural form feature of the avian musculoskeletal system with different definitions in terms of morphogenesis, resultant morphology, and functional role(s). Interpretation of these structural elements and their pattern(s) among avian taxa at different systematic levels is reviewed with regard to age-related changes in tendon, form features in avian phylogeny, and adaptive features in biomechanics and kinematics of locomotion. Specific examples of patterns in the musculoskeletal elements of the head and hyolingual system, axial (vertebral) system, and the limbs in several avian taxa are given. A series of questions is formulated as a prospectus for further study. © 1995 Wiley-Liss, Inc.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052260105
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  • 7
    Electronic Resource
    Electronic Resource
    Immunohistochemical localization of atrial natriuretic peptide in the developing and adult mammalian kidney (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 190 (1991), S. 182-191 
    Details
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The discovery, within the last decade, of atrial natriuretic peptide (ANP), a family of peptides with natriuretic/diuretic and vasorelaxant properties, has prompted much research into the mechanisms and sites of action of ANP within the kidney. In the present study, ANP was localized in the kidneys of several mammalian species by immunohistochemical techniques (1) to identify possible sites of synthesis; (2) to compare the localization of ANP to known physiological effects; (3) to determine species differences, if any, in ANP localization; and (4) to study the development of ANP immunoreactivity in the fetal and neonatal rat kidney. Using an antibody against rat ANP IV, ANP was localized exclusively on the proximal convoluted tubule (PCT) brush border and within intercalated cells of the outer medullary and cortical collecting tubules and ducts of adult mouse, rat, pig, monkey, and human kidneys. The development of ANP immunoreactivity paralleled the differentiation and maturation of collecting duct epithelium in rat fetal kidney. Atrial natriuretic peptide found within intercalated cells of the cortical and outer medullary collecting ducts may be the result of endogenous synthesis and, following secretion, may be available to receptors in the inner medullary collecting ducts.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aja.1001900207
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  • 8
    Electronic Resource
    Electronic Resource
    d' arsonval medal: Introduction Om P. Gandhi: 1995 receipient of the d' arsonval medal (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 17 (1996), S. 1-2 
    Details
    ISSN: 0197-8462
    Keywords: Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.1996.2250170102
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  • 9
    Electronic Resource
    Electronic Resource
    The effect of pulsed microwaves on passive electrical properties and interspike intervals of snail neurons (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 14 (1993), S. 503-520 
    Details
    ISSN: 0197-8462
    Keywords: constant temperature ; intracellular recording ; time series ; regression analysis ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: The effects of pulsed microwaves (2.45 GHz, 10 μs, 100 pps, SAR: 81.5 kW/kg peak, 81.5 W/kg average) on membrane input resistance and action potential (AP) interval statistics were studied in spontaneously active ganglion neurons of land snails (Helix aspersa), at strictly constant temperature (20.8±.07°C worst case). Statistical comparison with sham-irradiated neurons revealed a significant increase in the mean input resistance of neurons exposed to pulsed microwaves (P ≪ .05 ). Pulsed microwaves had no visible effect on mean AP firing rate; this observation was confirmed by analysis of interspike intervals (ISIs). Using an integrator model for spontaneously active neurons, we found the net input current to be more variable in neurons exposed to pulsed microwaves. The mean input current was not affected. The standard deviation of ISIs and the autocorrelation of the input current were marginally affected, but these changes were not consistent across neurons. Although the observed effects were less obvious than those reported in other studies, they represent evidence of a direct interaction between neurons and pulsed microwaves, in the absence of macroscopic temperature changes. The data do not suggest a single, specific mechanism for such interaction. © 1993 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250140603
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  • 10
    Electronic Resource
    Electronic Resource
    Microwave ablation of the atrioventricular junction in open-chest dogs (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 16 (1995), S. 97-105 
    Details
    ISSN: 0197-8462
    Keywords: atrioventricular block ; heat coagulation ; reversible and irreversible block ; catheter antenna ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: The use of microwave energy for ablation of the atrioventricular (AV) junction was examined in open-chest dogs. Using a specially designed microwave catheter and a 2450 MHz generator, microwave energy was delivered to the AV junction according to one of two protocols. In protocol 1, increasing amounts of energy were delivered until irreversible AV block occurred. In protocol 2, only two applications of energy were used, one at low energy and the other at an energy found to be high enough to cause irreversible AV block. Each dog received between one and six applications of microwave energy. The amount of energy delivered per application ranged from 25.6 to 311.4 J. No AV block was seen at 59.4 ± 28.3 J. Reversible AV block was seen with an energy of 120.6 ± 58 J. Irreversible AV block was seen at 188.1 ± 75.9 J. Irreversible AV block could be achieved in each animal. There was no difference in the energy required to cause irreversible AV block between the two protocols. The tissue temperature measured near the tip of the microwave catheter was correlated with both the amount of energy delivered and the extent of AV block caused. Histologic examination demonstrated coagulation necrosis of the conduction system. Microwave energy is a feasible alternative energy source for myocardial ablation. Since tissue damage is due exclusively to heating and the resulting rise in temperature can be measured, microwave energy may have advantages over currently existing energy sources in terms of both titrating delivered energy and monitoring the extent of tissue destruction. © 1995 Wiley-Liss, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250160205
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