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  • Calcium  (116)
  • Mouse  (70)
  • Springer  (185)
  • 1970-1974  (185)
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  • Springer  (185)
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  • 1
    ISSN: 1432-0568
    Keywords: X zone ; Electron microscopy ; Development ; Adrenal ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The postnatal development and involution of the X zone in the mouse adrenal cortex of both sexes were examined using the light and electron microscopes. At 0–5 days of age, no special cell group could be distinguished for the developing X zone in the inner cortex. The inner cortical cells contained spherical or ellipsoidal mitochondria with vesiculotubular cristae, vesiculotubular smooth endoplasmic reticulum (sER) and electron-lucent lipid droplets. The first sign of the developing X zone was the appearance of small groups of cells in juxtamedullary region differing from the cells in other part of inner cortex at 8 days. The electron microscopy showed that such cells contained nuclei of somewhat irregular outline and some parallel stacks of flattened sER. At 10–11 days, a thin layer of small eosinophilic cells were clearly identified as the developing X zone light microscopically in both sexes. Electron microscopically, the X zone cells showed a much dense cytoplas, which contained abundant sER, many mitochondria and numerous ribosomes. The typical X zone cells were characterized by the formation of peculiar mitochondrial complexes and whorled pattern of the sER. Mitoses were often found in the X zone, where mitotic cells even contained the whorled sER and bizarre mitochondria characteristic of the typical X zone cells. In the male the X zone rapidly involuted and might disappear by 30 days of age, whereas in the female X zone persisted as a thicker layer with the earlist sign of fatty degeneration. The origin of the X zone cell and the process of formation of its characteristic organelles are discussed.
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  • 2
    ISSN: 1432-0568
    Keywords: Colonic mucosa ; Mouse ; Vacuolated cells ; Electron microscopy ; Morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Swiss ICR adult male mice were used to analyse regional morphologic differences in the mucosa of the colon. The three cell types recently described in the descending colon of the mouse were also observed in the transverse and in the ascending colon. However the vacuolated cells of the crypts have presented different morphological characteristics depending on their localisation. In the ascending colon, they exhibited small supranuclear vesicles in contrast to the large vesicles observed in the descending colon. Several cell combining features of argentaffin-vacuolated, goblet-vacuolated and goblet-argentaffin cells have been observed. Furthermore a special type of granule referred to as a secondary lysosome was observed in the peripheral area of the typical goblet cells.
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  • 3
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    Anatomy and embryology 144 (1974), S. 195-203 
    ISSN: 1432-0568
    Keywords: Development ; Adrenal glands ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Untersuchung der vorgeburtlichen Entwicklung der Nebennieren erfolgte an H.-E.-Schnitten und wurde ergänzt durch den Nachweis alkalischer Phosphatase. 1. Markzellen beginnen mit 11–12 Tagen in das Rindenblastem einzuwandern. Mit 14 Tagen a.p. ist die Einwanderung bereits abgeschlossen, d.h. viel früher als bei menschlichen Embryonen entsprechenden Alters. 2. Der Cortex beginnt sich am 11. Tag zu entwickeln, wie bei menschlichen Embryonen vergleichbaren Alters. Vor der Geburt kann bei der Maus nicht zwischen einem “fetalen” und “permanenten” Cortex unterschieden werden. 3. Eine frühzeitige Einwanderung von versprengten Geschlechtszellen kann in der Cortexanlage durch die Reaktion auf alkalische Phosphatase nachgewiesen werden. Später verschwinden sie wieder. Eine Infiltration von Leuko-und Lymphocyten besteht nicht. Beim Herannahen des Geburtszeitpunktes treten aber Blutbildungsherde auf.
    Notes: Summary A detailed reinvestigation of the prenatal development of the adrenal gland has been carried out, using H.-E. sections supplemented by investigation of alcaline phosphatase activity. 1. Medullary cells start to invade the cortex blastema at 11–12 days. Immigration is completed at 14 days a.p., i.e. much earlier than in human embryos of corresponding age. 2. Cortex development starts at 11 days, like in human embryos of corresponding age. Before birth, there is no distinction between “fetal” and “permanent” cortex in mice. 3. Early invasion of gonocytes into the cortex blastema can be demonstrated by alcaline phosphatase reaction. Later on they disappear. There is no infiltration of leuco-and lymphocytes. Near term foci of blood-forming cells are appearing.
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  • 4
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    Springer
    Anatomy and embryology 144 (1974), S. 205-214 
    ISSN: 1432-0568
    Keywords: Adrenal gland ; Juxtamedullary X-zone ; Mouse ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die postnatale Entwicklung der Nebennieren wurde an hybriden Mäusen (Kreuzung der Inzuchtstämme C57BL/6 und CBA) und an nu/+ Mäusen (BALB/c) untersucht. Dabei standen uns von weiblichen und männlichen Tieren beider Stämme Schnittserien der folgenden Stadien zur Verfügung: 1, 7, 14, 21, 42, 63 und 84 Tage. Neben Zona glomerulosa und Zona fasciculata weist die Nebennierenrinde 2–3 Wochen alter Mäuse zwei innere Schichten auf. An die dem Mark anliegende, schon mehrfach beschriebene X-Zone schließt sich nach außen ein Gürtel kleiner Zellen an. Diese zwischen X-Zone und Fasciculata gelegene, bei Weibschen stärker ausgeprägte Rindenschicht bildet sich mit dem Verschwinden der X-Zone zurück. Wegen ihrer morphodynamischen und wahrscheinlich auch funktionellen Eigenständigkeit haben wir diese Schicht von der X-Zone abgetrennt und als kleinzellige Zone bezeichnet. Auf Grund unserer Beobachtungen neigen wir zur Ansicht, daß die definitive Zona reticularis aus der kleinzelligen Zone hervorgeht. Der Zeitpunkt beginnender Rückbildung der X-Zone zegt neben den bekannten geschlechtsabhängigen Unterschieden eine ganz erhebliche Variabilität (bis 10 Wochen) zwischen den verschiedenen Tierstämmen. Die X-Zone der Maus und die fetale Zone der menschlichen Nebenniere können—obwohl beides vorübergehende Strukturen—, wegen ihrer verschiedenartigen Entwicklung kaum als Analoga betrachtet werden.
    Notes: Summary The postnatal development of the adrenal glands was investigated in hybrid mice (from crossing the two inbred strains C57BL/6 and CBA) and in nu/+ mice (BALB/c). Serial sections of the following stages: day 1, 7, 14, 21, 42, 63, and 84 respectively from both strains and sexes were studied. The adrenal cortex of 2–3 week old mice is structurally differentiated into the zona glomerulosa, the zona fasciculata and two inner zones: 1: the well known x-zone surrounding the medulla; 2: a distinct zone (more pronounced in females, than in males) of small cells lying between the x-zone and the zona fasciculata. The latter disappears parallel to the removal of the x-zone. In view of the distinct morphological, developmental and probably even functional individuality of this zone, it was separated from the x-zone and given the name “zone of small cells”. It is assumed, that the definitive zona reticularis originates from the zone of small cells. The time at which the x-zone starts to degenerate depends on the sex, and varies considerably from one strain to another. The x-zone of the mouse and the fetal zone of the human adrenal gland—both transitory structures—differ too much in their development to be considered as analogous structures. New-born mice show a positive chromaffine reaction of the medullary cells. During the first 3 weeks the intensity of reaction increases considerably and then remains at the higher level for the time of further development.
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  • 5
    ISSN: 1432-0568
    Keywords: Development ; Genetics ; Mouse ; Vertebrae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The recessive mutation, rachiterata, reduces the number of cervical vertebrae to 6 by shifting the cervico-thoracic boundary in a cranial direction, and produces partial duplication of the neural arch of the axis. Rachiterata also produces malformations of thoraco-lumbar vertebrae, often associated with fusions of ribs. These malformations are caused by a disturbed arrangement of somites first detectable in 11-day embryos.
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  • 6
    ISSN: 1432-0568
    Keywords: Embryology ; Mouse ; Muscle differentiation ; Physiologic cell necroses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Mice embryos from day 9 to 15 p.c. have been studied by 1. Supravital staining of the whole embryo with nile blue sulfate. 2. Light and 3. Electron microscopic investigation of serial sections from the longitudinal axis of the back of the trunk. Nile blue sulfate staining revealed segmental necroses in the back of mice embryos centrally between the intersegmental arteries. Necroses appeared in the cranial myotomes and extended to the caudal ones during the days 9 to 13 p.c. By light microscopy the necroses extended in the centre of the myotome to the ventromedial margin. Electron microscopy revealed in this area myoblast-like cells rich in filaments, arranged in parallel without striation. A part of these myoblasts were electron-opaque and the nucleus was no longer evident. Forming vortices of filaments, these cells on the cranial and caudal end of the myotomes ceased fusion with the more centrally situated myoblasts. Vortices of filaments were also found in phagolysosomes of macrophages on day 12 p.c. On the same day of gestation we found an unsegmented myoblastema with irregular long myoblasts and striated polynuclear muscle fibres, arranged parallel to the neural tube. Between and parallel to the muscle fibres elongated individual cells could be seen, growing necrotic. Their nuclei were electron-dense with the chromatin clumping cap-like on the inner nuclear membrane. Fragments of myofibrils, corresponding approximately to sarcomeres, were dispersed irregularly as filament logs in the cytoplasm. Logs of filaments were bent at an obtuse angle, partly showing remnants of Z line material. In this stage of necrosis cells were phagocytized by macrophages. After disintegration of the segmental arrangement in scleroblastemata and myoblastemata a segmental rearrangement was not achieved by segmental shifting or by necrotic liquefaction zones. Whether the described cell necroses are due to differentiation, or even to phylogenetic causes is discussed.
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  • 7
    ISSN: 1432-0568
    Keywords: Dorsal lateral geniculate nucleus ; Morphology (ultrastructure) ; Mouse ; Synaptic vesicles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Neuronal perikarya, dendrites, extraglomerular neuropil, and synaptic glomeruli were examined by electron microscopy in the dorsal lateral geniculate nucleus (LGd) of the mouse. Particular attention was paid to boutons containing “flattened” synaptic vesicles. In line with recent studies of rat LGd (Lieberman and Webster, 1972; Lieberman, 1973), but in contrast to the findings of Rafols and Valverde (1973) on the mouse LGd, two distinct classes of ‘flat’-vesicle-containing boutons could be distinguished. P-boutons—were traced to and probably originate entirely from the presynaptic dendrites of the intrinsic neurons. They are concentrated within the glomeruli and are postsynaptic as well as presynaptic, being the intermediate elements in numerous intraglomerular serial synapses. F-boutons—are interpreted as axon terminals and are exclusively presynaptic. Some were traced from myelinated fibres. Synaptic vesicles are more concentrated in F-boutons than in P-boutons, appear flatter, and lie in a darker matrix. F-boutons synapse extensively in the extraglomerular neuropil, but are outnumbered by P-boutons in the glomeruli. The synaptic relationships established within the glomeruli are summarized.
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  • 8
    ISSN: 1432-0568
    Keywords: Leydig cells ; Differentiation ; Explants ; Ultrastructure ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Testes of newborn mice not older than one day were transplanted into the anterior chamber of one eye of an adult male white Holtzman rat. The events observed in the Leydig cells of the grafted testes can be divided into two periods. Period one is marked by differentiation; period two, by dedifferentiation. In period one, the lipid and glycogen inclusions disappear, possibly owing to the gonadotropins of the host. In period two, which starts after day 15 post-grafting, the lipids and glycogen reappear; the Leydig cells now contain residual bodies, whereas the S.E.R. disappears. Immunological mechanisms can be implicated; it is suggested that the Leydig cells dedifferentiate because the host's gonadotropins may be incapable of evoking and/or activating the genetic memory of the grafted Leydig cells.
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  • 9
    ISSN: 1432-0827
    Keywords: Calcium ; Thyroïd ; Calcitonin ; Hibernation ; Electron microprobe
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Une quantité importante de calcium se trouve conservée dans la thyroïde de Mammifères soumise à des traitements histologiques qui en eliminent la forme diffusible et les sels minéraux. Sur six espèces examinées, seul l'hibernantElyomis quercinus L. (Lérot) fait exception. Ce calcium, vraisemblablement engagé en combinaisons organiques, se répartit entre la colloïde, les cellules à calcitonine et les noyaux des deux lignées de cellules endocrines. Dans calcitonine, il revêt les grains de sécrétion d'une coque dense. Dans les noyaux, enfin, où sa teneur est très variable, il ne semble pas correspondre en totalité au cation habituellement lié aux acides nucléiques. Il existe, en outre, un calcium diffusible bien représenté dans les espaces intercellulaires et le long des lames basales. La forme diffusible se trouve aussi bien chez l'hibernant que dans les cinq autres espèces.
    Abstract: Zusammenfassung Nach routinemäßiger Aufarbeitung der Säugerschilddrüse für Histologie, bei welcher diffusionsfähiges Calcium und Mineralsalze eliminiert werden, bleiben erhebliche Mengen von Calcium erhalten. Von 6 untersuchten Arten ist der WinterschläferEliomys quercinus L. (Gartenschläfer) die einzige Ausnahme. Das vermutlich organisch gebundene Calcium verteilt sich auf das Kolloid, die Calcitoninzellen und die Zellkerne beider endokriner Zellstämme. Im Kolloid befindet es sich meist in den intrafollikulären Zellen; in den Calcitoninzellen umgibt es die Sekretkörner mit einer dichten Hülle; der Calciumgehalt der Zellkerne unterliegt großen Schwankungen und das Metall scheint nicht nur an die Nukleinsäuren gebunden zu sein. Ferner ist in der Schilddrüse diffusionsfähiges Calcium nachweisbar, das sich sowohl in den Interzellularräumen als auch entlang den Basalmembranen befindet; sowohl die Schilddrüse der winterschlafenden Art als auch die der anderen 5 Spezies enthalten Calcium in dieser Form.
    Notes: Abstract Large quantities of calcium are preserved in the thyroïd of Mammals after removal of the diffusible form and mineral salts by routine histological processes. Among the six species studies, only the hibernating species,Eliomys quercinus (garden dormouse), constitutes an exception. This calcium, probably bound organically, is localised in the colloïd, calcitonin cells and nuclei of both types of endocrine cells. In the colloïd, it is often associated with intrafollicular cells. In calcitonin cells, it densely coats the secretion granules. In nuclei, where the quantities of calcium vary greatly, it does not appear to correspond entirely to the cation usually associated with nuclei acids. Moreover, appreciable amounts of diffusible calcium are present in intercellular spaces and along basal laminae. This diffusible form exists in the hibernating species as well as in the five other species.
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  • 10
    ISSN: 1432-0827
    Keywords: Bone ; Calcium ; Deficiency ; Osteoporosis ; Species
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract 21-day-old rats and mice were fed a low-calcium diet (0.02% Ca) or a normal diet (0.5% Ca) for two weeks. Administration of the low-calcium diet resulted in greater decreases in femur ash content and serum calcium in rats than in mice. Microscopic examination revealed that metatarsal bones from a majority of the rats fed a low-calcium diet displayed moderate or severe osteoporotic changes whereas bones from mice were either normal or displayed only slight osteoporotic changes under the same experimental conditions. These results indicate that mice are better able to adapt to a low-calcium diet than are rats of the same age.
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  • 11
    ISSN: 1432-0827
    Keywords: Fluoride ; Calcium ; Phosphorus ; Bone ; Periosteum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Une méthode d'estimation de la surface périostée de l'os en voie de minéralisation est mise au point et appliquée à des porcs recevant 2 mg de fluorure par Kg de poids et par jour pendant 10 mois. L'adjonction de fluor intervient significativement dans le cas d'une déficience en calcium et phosphore. La surface en voie de minéralisation est nettement réduite. Lorsque le calcium et phosphore sont normaux, l'addition de fluorure augmente nettement la surface en voie de minéralisation. Le microscope électronique à balayage permet de mettre en évidence au niveau de l'os une perte de l'orientation longitudinale des fibers et des surfaces poreuses irrégulières chez les animaux soumis au floor.
    Abstract: Zusammenfassung Zur Bestimmung der verkalkenden Oberfläche des Periosts wurde eine Methode entwickelt und bei Schweinen angewandt, welche während etwa 10 Monaten 2 mg Fluorid per kg Körpergewicht und per Tag erhalten hatten. Dieses zusätzliche Fluorid hatte eine signifikante Wirkung bei Calcium- und Phosphormangel. Die verkalkende Oberfläuche ging stark zurück, während jedoch, wenn kein Calcium- und Phosphormangel bestand, das zusätzliche Fluorid die verkalkende Oberfläche vergrößerte. Beobachtungen mit dem Raster-Elektronenmikroskop am Knochen zeigten, daß die Längsorientierung der Fasern fehlte und daß Knochen von mit Fluorid gefütterten Tieren unregelmäßige, poröse Oberflächen aufwiesen.
    Notes: Abstract A method for estimating periosteal bone-mineralizing surface was developed and applied to swine fed 2 mg of fluoride/kg of body weight/day for about 10 months. Added fluoride interacted significantly with calcium and phosphorus deficiency. Mineralizing surface was greatly reduced, whereas when calcium and phosphorus were adequate, added fluoride greatly increased mineralizing surface. Scanning electron microscope observations of bone disclosed loss of longitudinal orientation of fibers and irregular porous surfaces in bone from fluoride-fed animals.
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  • 12
    ISSN: 1432-0827
    Keywords: Bone ; Phosphate ; ATP ; Calcium ; Mitochondria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract An active constituent of the leaves ofSolanum malacoxylon (SM) is shown to promote calcium resorption and citrate production in embryonic chick frontal bone culturedin vitro. When injected into rats, SM reduces the ATP content of liver and kidneys. This phenomenon may be related to the ability of SM to stimulate mitochondrial ATPase activity at pH 9.4. SM significantly reduces the concentration of phosphate necessary to alter the uptake of calcium and respiration of siolated mitochondria. The data suggest that SM influences calcium and phosphate metabolism by affecting ion movements into and out of mitochondria.
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  • 13
    ISSN: 1432-0827
    Keywords: EHDP ; Intestinal transport ; Calcium ; Vitamin D ; Microvilli
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé De l'éthane-1-hydroxy-1,1-diphosphonate (EHDP), administré par voie sous-cutanée à des rats à doses élevées (10 mg P/Kg de poids par jour×10), inhibe le transport du calcium au niveau du duodenum de rats, en utilisant des rapports de concentration serum/muqueuse en45Ca pour mesurer le transfert actif. Des études de microscopie électronique montrent l'accumulation de granules denses aux électrons dans les microvillosités: ces granules seraient constitués par une forme de calcium lié. On note aussi la rareté de ces granules dans les mitochondries; ces modifications sont analogues à celles observées dans les rats rachitiques. Il semble que les phénomènes pathologiques soient liées à un trouble du transport du calcium des microvillositées vers d'autres sites intracellulaires.
    Abstract: Zusammenfassung Es zeigte sich, daß bei Ratten, die mit hohen Dosen (10 mg P/kg Körpergewicht täglich×10) von Aethan-1-hydroxy-1,1-diphosphonat (EHDP) subkutan behandelt wurden, der Calciumtransport im Duodenum (gut sacs) gehemmt wurde; zur Messung des aktiven Transportes wurde das45Ca-Konzentrationsverhältnis Serosa/Mucosa benützt. Elektronenmikroskopische Untersuchungen zeigten in den Microvilli eine Anhäufung von elektronendichten Granula, die eine gebundene Form von Calcium darstellen; eine kleine Anzahl solcher Granula fand sich in den Mitochondrien; diese Veränderungen können auch bei rachitischen Ratten beobachtet werden. Aus den Resultaten kann geschlossen werden, daß dieser Defekt teilweise durch eine Interferenz des Calciumtransportes von den Microvilli zu anderen intrazellulären Stellen bedingt ist.
    Notes: Abstract Ethane-1-hydroxy-1,1-diphosphonate (EHDP) given subcutaneously to rats in high doses (10 mg P/Kg body weight daily×10) inhibited the transport of calcium by rat duodenal gut sacs, when45Ca serosal/mucosal concentration ratios were used to measure active transport. Electron microscopic studies revealed the accumulation of electron-dense granules in the microvilli, representing a bound form of calcium and a paucity of such granules in mitochondria, changes identical to those seen in rachitic rats. These results suggest that the defect is mediated in part by interference in transport of calcium from microvilli to other intracellular sites.
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  • 14
    ISSN: 1432-0827
    Keywords: Calcitonin ; Calcium ; Uptake ; bone culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract The effect of calcitonin (CT) on calcium metabolism by bone was investigated in a stationary organ culture system, using half-calvaria from 5-day-old mice. CT induced the uptake of calcium by bones from the culture medium. This uptake was not accompanied by phosphate, so that the final Ca:P ratio of CT-treated bones (1.80±0.06) was significantly (p〈0.02) higher than the initial values before culture (1.59±0.03). The calcium uptake reached a plateau after approximately 48 hours of culture, and was reversed by PTH within 48 hours. Calcium uptake rppears to be an active effect of CT, and cannot be explained fully by an inhibition of bone aesorption, stimulation of new bone formation, or maturation of the mineral phase.
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  • 15
    ISSN: 1432-0827
    Keywords: Biopsy ; Bone ; Calcium ; Phosphorus ; Specific gravity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract The specific gravities (SG) of bone samples taken from various parts of the skeleton of cattle and sheep were determined gravimetrically in an effort to establish which sites give the most reproducible and uniform results, so that between animals, or sequential within animals, comparisons may be made with maximum sensitivity. Samples obtained from the mandible of sheep and the rib of cattle and sheep were found to be too variable to be useful for most purposes. Best results were obtained using whole bones which are easily prepared, such as the tibial tarsal bones of cattle and sheep and the fibular tarsal bone of cattle. These bones gave within animal deviations of 0.012–0.024 SG units, when comparing left bone with right bone. Slightly higher values were obtained for coccygeal vertebrae from cattle and distal metacarpal condyles from sheep. SG was related to ash, calcium and phosphorus contents of coccygeal vertebrae of cattle and it is considered that, for survey work on the mineral status of the bones of cattle and sheep, the correlations are sufficiently high to make their determination unnecessary. This will enable radiation determined SG techniques to be applied to this type of work.
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  • 16
    ISSN: 1432-0827
    Keywords: EDTA ; Bone resorption ; Parathyroid hormone ; Calcium ; Hydroxyproline
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract The effects of ethylenediaminetetraacetate (EDTA) were studied in rats. Intravenous infusion of 4.84 mM Na2EDTA increased the urinary excretion of calcium six-fold, phosphorus three-fold and hydroxyproline 55% in 158 g thyroparathyroidectomized (TPTXed) rats. Calcitonin (25 MRC mU/rat/h) abolished the sodium EDTA-induced increase in hydroxyproline excretion, presumptive evidence that sodium EDTA was acting on bone. To determine whether the changes induced by sodium EDTA are due to lowering of plasma calcium, rats were infused with 4.84 mM ethylenebis(oxyethylenenitrilo)tetraacetic acid (EGTA), a more specific calcium chelator. EGTA increased the urinary excretion of calcium and phosphorus (P〈0.001) but not hydroxyproline in thyroparathyroidectomized rats. Furthermore, when TPTXed rats were infused with calcium EDTA (4.84 mM Ca2EDTA) in order that ionic calcium concentration would not be altered, hydroxyproline excretion was again markedly increased but phosphorus excretion was decreased by 26%. Since the displacement of the sodium ions in Na2EDTA by calciumin vivo is instantaneous, and since calcium EDTA itself induces collagenolysis, the increase in urinary hydroxyproline excretion due to sodium EDTA cannot be attributed solely to lowering of plasma calcium. From these data two conclusions are drawn. First, sodium EDTA enhances bone breakdown independently of its effect on parathyroid hormone secretion. Second, since bone plays a major role in the maintenance of plasma calcium, interpretation of results should be made with caution in those investigations in which EDTA is used to study calcium homeostasis.
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  • 17
    ISSN: 1432-0827
    Keywords: Vitamin D ; Bone ; Resorption ; Calcium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract A series of analogues of vitamin D have been tested for their ability to stimulate bone resorption in two test systems used previously to investigate the metabolites of vitamine D. These analogues were tested (a) by directly comparing their action on bone explants of mouse half-calvariain vitro, and (b) by injecting them into young mice and measuring the degree of resorptionin vitro when explants were prepared 18 hours after the injection. It is concluded that the key functional groups concerned with enhancing the activity of vitamin D3 are the 1α- and the 25-hydroxyl,both together; the cis ring structure for ring A appears necessary. 1α-Hydroxycholecalciferol (1α-OHD3) is about as active as 25-OHD3 in the direct test, but its potency is much nearer to that of 1,25-(OH)2D3 when tested by the second (indirect) method; it seems likely that 1α-OHD3 is converted into 1,25-(OH)2D3 in vivo. The results are discussed in relation to the designing of analogues for clinical and experimental use.
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  • 18
    ISSN: 1432-0827
    Keywords: Age ; Bone culture ; Calcium ; Phosphate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Calvaria taken from mice aged 0, 1, 3 and 5 days were cultured for 48 h, in control medium (no added hormone), or in the presence of PTH (0.5 U/ml) or CT (50 mCl/ml). In the control group, there was a shift from net uptake of Ca and P (0- and 1-day bones) to net release (5-day bones). CT-treated bones of all ages took up Ca from the culture medium, but the percentage uptake declined with increasing age. Bones exposed to PTH released Ca and P to the culture medium, regardless of age. The changes with increasing age may be related to an increase in mineralization and other aspects of maturation in these bones.
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  • 19
    ISSN: 1432-0827
    Keywords: Serum ; Calcium ; Phosphate ; Alkaline phosphatase ; Kidney
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract In 30 patients with chronic renal insufficiency (16 non-dialysed and 14 on dialysis) serum calcium, phosphate and alkaline phosphatase were determined and, in a crest biopsy specimen, morphometric determinations of bone qualities were calculated. A positive correlation was established between serum alkaline phosphatase, the osteoblast surface and the active resorption surface in both dialysed and non-dialysed patients. A positive correlation was also established between the osteoblast surface and the active resorption. In the non-dialysed patients a negative correlation was established between serum calcium and the osteoid surface.
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  • 20
    ISSN: 1432-0827
    Keywords: Snails ; Vaterite ; Calcium ; Storage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Large quantities of calcium carbonate crystals were present in the albumin gland of the reproductive system of the fresh-water snailPomacea paludosa. X-ray diffraction analyses indicated that they were vaterite. Scanning electron microscope observation of the albumin gland revealed that they occurred as spherules and were distributed throughout the gland. Vaterite spherules were present in the albumin gland ofPomacea urceus and the capsule gland ofPila virens. The mineral portion of the egg capsules was also vaterite. The egg capsule of these snails consisted of two morphologically distinct layers. Vaterite is less common in nature than the other two polymorphs of calcium carbonate, calcite and aragonite, and has not been recorded in the reproductive system of molluscs. It is interesting to note that in these snails calcium carbonate was present as vaterite both in the storage organ and fully differentiated egg capsule.
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  • 21
    ISSN: 1432-0827
    Keywords: Calcification ; Neutral sites ; Elastin ; Calcium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Des études précédentes suggèrent la présence de groupements carboxyles, sulfhydriles et aminés dans les sites de liaison en calcium de l'élastine. La possibilité de l'existence de sites neutres de liaison en calcium au niveau de l'élastine a été étudiée dans ce travail. Une augmentation de la fixation du calcium au niveau de l'élastine est observée après des modifications de dissolution qui ont aussi provoqué des modifications de structure de la protéine. Dans des mélanges méthanol-H2O, les liaisons du calcium semblent indépendantes du pH et de la force ionique. Sur dix ions testés (Ca2+, CO2+, Na2+, Cu2+, Zn2+, Cr3+, Pb+2, K+, Rb+ et Mg2+) seule la liaison du calcium est nettement augmentée, lorsque le méthanol est ajouté. Il semble que les sites neutres sont importants pour les divers rapports entre calcium et élastine et servent, peut-être, comme centres de nucléation au cours de la calcification de la protéine.
    Abstract: Zusammenfassung Vorgängige Studien haben die Bedeutung der Carboxyl-, Sulfhydryl- und Aminogruppen als Stellen der Calciumbindung im Elastin gezeigt. Die vorliegende Arbeit hatte zum Ziel, die Rolle der neutralen Koordinationsstellen im Elastin als mögliche Calcium-Bindungsseite abzuklären. Die Calciumbindindung an das Elastin wurde durch solche Lösungsmittelveränderungen erhöht, die auch gleichartige Verschiebungen im Proteinmolekül bewirkten. In Methanol-Wasser-Mischungen schien die Calciumbindung nicht von Veränderungen des pH oder der Ionenstärke abhängig zu sein. Von 10 Ionen, bei welchen die Bindung überprüft wurde, war einzig diejenige des Calciums signifikant erhöht, wenn Methanol zugesetzt wurde. Es wird vorgeschlagen, daß die neutralen Stellen für die verschiedenen Vorgänge, bei welchen Calcium und Elastin beteiligt sind, eine wichtige Rolle spielen und vielleicht für die Verkalkung der Proteine als Nukleationszentren in Frage kommen.
    Notes: Abstract Previous studies have implicated carboxyl groups, sulphhydryl groups and amino groups as the sites for calcium binding in elastin. In this study, the concept was investigated that neutral co-ordinating sites in elastin may also provide calcium binding sites. Calcium binding to elastin was increased upon solvent changes which also effected conformational changes in the protein. In methanol-H2O mixtures calcium binding appeared to be independent of changes in pH and ionic strength. Of ten ions tested (Ca2+, Co2+, Na+, Cu2+, Zn2+, Cr3+, Pb+2, K+, Rb+, and Mg2+), only calcium binding was significantly increased when methanol was added. It is proposed that neutral sites are important to the various relationships involving calcium and elastin and perhaps serve as nucleation centers in the calcification of the protein.
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  • 22
    ISSN: 1432-0827
    Keywords: Calcium ; Phosphate ; Inhibition ; Crystallization ; Nucleotides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The 5′-triphosphates of adenosine, guanosine, uridine, and cytidine inhibited the crystallization of calcium phosphate from stable supersaturated solutions that had been seeded with crystals of hydroxyapatite. Concentrations of the nucleoside triphosphates in the micromolar range were sufficient to have a significant effect on the crystal growth process. Diphosphate and monophosphate derivatives had less effect on the precipitation of calcium phosphate. It is possible that the nucleoside triphosphates may play a beneficial role in regulating intracellular calcification, particularly in disease states in which calcium entry into cells is pathologically high.
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  • 23
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    Electronic Resource
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    Calcified tissue international 16 (1974), S. 139-144 
    ISSN: 1432-0827
    Keywords: Dental enamel ; Iron ; Calcium ; Phosphorus ; Electron probe
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Using electron microprobe analysis, the surface layer of enamel of rat maxillary incisors was found to contain 10–30% Fe. The Ca and P concentrations in different areas of the enamel surface varied inversely with the Fe concentration. The Ca/P weight ratio was 1.8 in areas containing 10% Fe, but decreased to 1.0 in the most Fe-rich areas. The Fe concentration was highest at the prism boundaries, whereas the maximum concentrations of Ca and P were found within the enamel prisms. The concentrations of Fe in rat incisor enamel are among the highest values reported for any mineralized tissue.
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  • 24
    ISSN: 1432-0827
    Keywords: Hypothyroidism ; Hyperthyroidism ; Nephrocalcinosis ; Calcium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Meriones unguiculatus (jirds or ‘gerbils’) were rendered hypo- or hyperthyroid by the addition of carbimazole or liothyronine to their diet, and in each of these states were found to be highly susceptible to the nephrotoxic effects of calcium gluconate. Histological studies showed that the pattern of induced nephrocalcinosis was the same in the hypo-, hyper- and eu-thyroid animals and was in the form of calcium deposits both within the cells of the proximal and distal convoluted tubules and in the basement membranes around such tubules. In view of these findings analysis of thyroid function should perhaps be incorporated into the list of diagnostic procedures used in the investigation of patients with nephrocalcinosis and nephrolithiasis.
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  • 25
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    Calcified tissue international 16 (1974), S. 339-342 
    ISSN: 1432-0827
    Keywords: Calcium ; Resorption ; Shell membrane ; Chick ; Chloride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract A histochemical test for chloride was conducted on shell membranes from hen eggs incubated for 9 or 17 days. After fixation with a mixture of osmium tetroxide and silver nitrate and subsequent exposure to direct sunlight, the membranes showed an abundant coarse precipitate. This precipitate did not appear in sections treated with a solution of nitric acid indicating that it did not contain chloride. However, a small amount of fine acidresistant precipitate was detected by electron microscopy and probably contained chloride. The theory which defines hydrochloric acid as the main solubilizing agent of shell mineral is based on histochemical results which supposedly demonstrate large concentrations of chloride in the shell membrane and chorionic epithelium. The present results do not support these observations.
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  • 26
    ISSN: 1432-0827
    Keywords: Diphosphonates ; Calcium ; Mitochondria ; ATPase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract The effect of two diphosphonate compounds on calcium handling in rat kidney mitochondria has been studiedin vitro. Initial calcium uptake in the presence of an oxidisable substrate and ATP was not influenced by either diphosphonate tested. The release of accumulated calcium from the mitochondria was, however, delayed by these compounds and the effect was found to be dose dependent. Similarily, a second uptake of calcium, induced by re-addition of ATP following preliminary release, was also modified by diphosphonates, the mitochondrial suspensions incubated with diphosphonates accumulating more calcium than control suspensions. The effect of these compounds could not be detected on three mitochondrial ATPase systems. The results have been discussed in relation to knownin vivo effects of diphosphonates.
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  • 27
    ISSN: 1432-1440
    Keywords: Uremic osteodystrophy ; parathyroid hormone ; magnesium ; calcium ; secondary hyperparathyroidism ; Urämische Osteopathie ; Serum-Parathormon ; Magnesium ; Calcium ; sekundärer Hyperparathyreoidismus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Erhöhung der Dialysat-Magnesium-Konzentration von 1,5 mval/l auf 2,5 mval/l bei Verwendung einer Dialysat-Calcium-Konzentration von 3,5 mval/l führte zu keiner signifikanten Reduktion der radioimmunologisch gemessenen Serum-Parathormonspiegel. Bei ausreichend hohen Dialysat-Calcium-Konzentrationen bewirkt somit die Erhöhung der Dialysat-Magnesiumspiegel keine weitere meßbare Reduktion der PTH-Ausschüttung.
    Notes: Summary An inerease of dialysate magnesium concentration from 1.5 mval/l to 2.5 mval/l did not reduce significantly i PTH levels in haemodialysed patients, dialysed against 3.5 mEq Ca/l in the dialysate. Thus, when sufficiently high Ca concentrations in the dialysate are used, no further reduction of serum PTH levels is seen by elevating Mg in dialysate.
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  • 28
    ISSN: 1432-1440
    Keywords: Gastrin ; gastric secretion ; calcium ; normal subjects ; duodenal ulcer ; Zollinger-Ellison syndrome ; Gastrin ; Magensekretion ; Calcium ; Normalpersonen ; Ulcus duodeni ; Zollinger-Ellison-Syndrom
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Der Einfluß einer induzierten Hypercalcämie auf die Serumgastrinspiegel und die Magensekretion wurde bei Normalpersonen, Patienten mit Ulcus duodeni und Patienten mit Zollinger-Ellison-Syndrom untersucht. Bei allen Patientengruppen kommt es während der Calciumgluconatinfusion zu einem signifikanten Anstieg der Serumgastrinspiegel. Patienten mit Ulcus duodeni schütten jedoch 2–3mal soviel Gastrin während einer Hypercalcämie aus wie Normal-personen, während die Gastrinausschüttung bei Patienten mit Zollinger-Ellison-Syndrom ein Vielfaches der von Ulcus duodeni-Patienten beträgt. Die integrierte Säureausschüttung während Hypercalcämie ist bei Ulcus duodeni-Patienten ca. 5fach höher als bei Kontrollpersonen. Diese Untersuchungen zeigen, daß die Calcium-induzierte Magensekretion, zumindestens teilweise, durch eine Gastrinfreisetzung hervorgerufen wird.
    Notes: Summary We studied the effect of hypercalcemia on the serum gastrin concentration and gastric secretion in normal man, duodenal ulcer patients and patients with the Zollinger-Ellison syndrome. All subjects showed a significant increase of serum gastrin concentrations during calcium infusion. Patients with duodenal ulcer showed a 2- to 3-fold higher gastrin output during hypercalcemia than normal subjects, but the gastrin output in patients with Zollinger-Ellison syndrome was much higher compared to patients with duodenal ulcer. The integrated gastric secretory response to hypercalcemia is 5-fold higher in duodenal ulcer patients compared to normal subjects. These studies show that, at least in part, the calcium-induced gastric secretion is caused by gastrin release.
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  • 29
    ISSN: 1432-1440
    Keywords: Calcium ; parathyroid hormone ; phosphate ; primary hyperparathyroidism ; Calcium ; Parathormon ; Phoshpat ; primärer Hyperparathyreoidismus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Konzentration des immunoreaktiven Parathormons im Serum (iPTH) vor und nach Phosphatinfusion (3 Std) wurde bei 8 Patienten mit später chirurgisch verifiziertem primärem Hyperparathyreoidismus gemessen. Bei allen Patienten kam es zu einem Anstieg des iPTH. Es bestand eine enge Korrelation zwischen dem prozentualen Anstieg des iPTH und dem Abfall der Serumcalciumkonzentration. Diese Beziehung weist darauf hin, daß eine Steigerung der Parathormonsekretion durch eine Hypocalcämie beim primären Hyperparathyreoidismus hervorgerufen wird und die Sekretion deshalb nicht autonom erfolgt.
    Notes: Summary Serum immunoreactive parathyroid hormone (iPTH) was estimated before and after phosphate infusions (3 hr) in 8 patients with hyperparathyroidism later proven surgically. An increase in iPTH was invariably observed. The increase expressed as the percentage of the basal iPTH was related to the decrease of the serum calcium concentration, suggesting that induced hypocalcaemia increased PTH secretion in primary hyperparathyroidism.
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  • 30
    ISSN: 1432-1440
    Keywords: Magnesium ; calcium ; pancreas ; secretin. pancreozymin ; chronic pancreatitis ; primary hyperparathyroidism ; Magnesium ; Calcium ; Pankreas ; Sekretin ; Pankreozymin ; chronische Pankreatitis ; primärer Hyperparathyreoidismus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Die Sekretion von Magnesium (Konzentration und Ausscheidung) wurde im menschlichen Duodenalsaft vor und nach Stimulation des Pankreas mit Sekretin und Pankreozymin gemessen und mit den Werten für Calcium verglichen. Es wurden 27 Personen mit normaler Pankreasfunktion, 23 Patienten mit mäßiger und 22 mit ausgeprägter Pankreasinsuffizienz sowie 14 Kranke mit primärem Hyperparathyreoidismus untersucht. 2. In allen Funktionszuständen des Pankreas wurden bei normaler Bauchspeicheldrüse Magnesium und Calcium parallel sezerniert, die Korrelation war signifikant positiv. Nach Sekretin erniedrigte sich die Konzentration. Pankreozymin erhöhte sowohl die Konzentration als auch die Ausscheidung. 3. Die parallele Sekretion fand sich mit wenigen Ausnahmen auch bei Pankreasinsuffizienz. Hier war die Sekretion beider Elektrolyte nach Pankreozymin signifikant erniedrigt, wenn auch die Enzymsekretion vermindert war. 4. Bei primärem Hyperparathyreoidismus fand sich bei normaler Pankreasfunktion eine gegenüber der Norm erhöhte Konzentration und Ausscheidung für Magnesium und Calcium nach Pankreocymin, während bei gestörter Enzymsekretion auch die Elektrolytsekretion vermindert war. Bei Hyperparathyreoidsmus wurde die Magnesiumsekretion durch Pankreozymin stärker stimuliert als die von Calcium. Die Parallelität im Verhalten von Magnesium und Calcium war hier nicht mehr gewahrt.
    Notes: Summary 1. The secretion of magnesium (concentration and output) was measured in human duodenal juice before and after stimulation of the pancreas by secretin and pancreozymin (1 unit/kg) and compared with the behaviour of calcium 27 subjects with normal pancreatic function, 23 patients with moderate and 15 with severe pancreatic insufficiency and 14 patients with primary hyperparathyroidism were investigated. 2. In all functional states of the normal pancreatic gland magnesium and calcium were secreted in close positive correlation. The concentration was lowered after secretin. Pancreozymin increased both the concentration and the output of the two electrolytes. 3. The parallel secretion was also found, at few exceptions, in the patients with pancreatic insufficiency. Here, the secretion of both electrolytes was significantly diminished after pancreozymin together with the lowered secretion of enzymes. 4. In primary hyperparathyroidism associated with normal pancreatic function a higher than normal concentration and output of magnesium and calcium after pancreozymin were measured. When enzyme secretion was disturbed in these patients as well the secretion of the two electrolytes was lowered. In primary hyperparathyroidism the secretion of magnesium was more markedly stimulated by pancreozymin than that of calcium. The parallelism in the behaviour of magnesium and calcium was no longer present in this situation.
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  • 31
    ISSN: 1432-1440
    Keywords: Haemodialysis ; calcium ; phosphate ; osteodystrophy ; hypertension ; Calcium ; Phosphat ; Hämodialyse ; Osteodystrophie ; Hypertonie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Aus den Konzentrationsunterschieden von Calcium und Phosphat im Dialysat von 100 Routinedialysen vor und nach der Dialyse wurde der Effekt von unterschiedlichen Dialysatcalciumkonzentrationen auf die Calcium-und Phosphatbilanz von chronisch-intermittierend dialysierten Patienten ermittelt. Dialyse mit einem Dialysatcalcium von 6 mg-% führte zu einer Calciumaufnahme von 72±36 mg (±SEM,n=63) und zu einem Phosphatentzug von 1019±37 mg (±SEM,n=63). Während der Dialyse mit einem Dialysatcalcium von 8 mg-% stieg die Calciumaufnahme auf 240±52 mg (±SEM,n=34), die Phosphatelimination fiel um denselben Betrag auf 856±50 mg (±SEM,n=34). Mit einem Dialysatcalcium von 8 mg-% kam es zwar zu einer postdialytischen Hypercalcämie von 11,5±0,9 mg-% (±SD), jedoch wurde ein signifikantes Absinken der prädialytischen Serumphosphatwerte und des für die Entstehung von metastatischen Calcifikationen entscheidenden Calciumphosphatproduktes beobachtet. Obwohl die Mehrzahl der biochemischen Veränderungen nicht gegen die Verwendung einer höheren Dialysatcalciumkonzentration sprechen würde, wird eine dem ultrafiltrierbaren Serumcalcium entsprechende Dialysatcalciumkonzentration von 6 mg-% empfohlen, nachdem sich bei einem Patienten nach wenigen Wochen der Verwendung einer höheren Dialysatcalciumkonzentration eine ausgeprägte und später reversible Hypertonie, bei einem anderen eine persistierende Hypercalcämie entwickelten.
    Notes: Summary In three patients with stable uraemia the external balance of calcium and phosphate was estimated during hemodialysis with a calcium concentration of 6 mg/100 ml and 8 mg/100 ml in the dialysate, by measuring both ions in the dialysate in 100 routine dialyses. Dialysis with a dialysate calcium of 6 mg/100 ml and 8 mg/100 ml led to a calcium uptake of 72±36 mg (±SEM,n=63) and 240±52 mg (±SEM,n=34), respectively, phosphate removal decreased significantly from 1019±37 mg to 856±50 mg respectively. Dialysis with a dialysate calcium of 8 mg/100 ml led to post dialysis hypercalcaemia of 11.5±0.9 mg/100 ml (±SD) which lasted occasionally until the beginning of the next dialysis, the predialysis phosphate levels and predialysis calcium phosphate product decreased significantly with this regimen. Although most of the induced biochemical changes are not against a dialysate calcium of 8 mg/100 ml, development of marked hypertension in one patient and persistent hypercalcaemia in another one after only five weeks of treatment were reason to abandon the recently suggested use of a dialysate calcium above the concentration of ultrafiltrable serum calcium, especially in the light of the comparatively small net gain of calcium during dialysis.
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  • 32
    ISSN: 1432-2013
    Keywords: Acidosis ; pH ; Cardiac Contractility ; Epinephrine ; Calcium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The inotropic effect of calcium and of epinephrine was examined in an isolated guinea pig atrial preparation during a simulated respiratory and metabolic acidosis. Special care was taken to avoid alterations in ionized calcium which usually accompany most forms of acidosis. In acidosis the inotropic response to epinephrine is depressed to a greater extent than the response to calcium, independent of respiratory or metabolic origin. It is concluded that the overall depression of the inotropic response to epinephrine is produced by two mechanisms: firstly, by an unspecific depression of contractility caused by a direct action of hydrogen ions on the heart, and secondly, by a specific depression of the inotropic epinephrine-effector mechanism. The dose-ratios for production of identical epinephrine-specific responses as compared with those at pH 7.5 were calculated. At a pH of 6.9, the doseratio was 1.5 to 2.5; at a pH of 6.6, it was in the range of 4 to 4.6. In conclusion these observations are in accordance with a concept that acute acidosis affects myocardial function in intact animals bydirect andindirect effects in at least four ways: by a depression of contractility, by a diminished responsiveness of the epinephrineinotropic response mechanism, by an increase in the concentration of ionized calcium, and by a release of catecholamines.
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  • 33
    ISSN: 1432-2072
    Keywords: Locomotor Activity ; Mouse ; Morphine ; Narcotic Antagonists
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Morphine-induced locomotor activity in mice has been investigated but there appear to be only a small number of reports on the effects of narcotic antagonists on this increased activity. Also, it is well known that some narcotic antagonists can act as both morphine antagonists and analgesics in nociceptive assays, but there have been few demonstrations of this stimulant and antagonistic action with locomotor activity studies. In this study, six compounds (cyclazocine levallorphan, diprenorphine (M-5050), nalorphine, naloxone, and naltrexone) have been investigated in regard to their activity as antagonists of morphine-induced locomotor activity and in regard to their ability to stimulate locomotor activity themselves. All six compounds antagonized the effect of morphine, but only cyclazocine and levallorphan produced any significant stimulation of locomotor activity by themselves at the doses tested. This study indicates that changes in mouse locomotor activity can be used successfully to monitor the interaction between morphine and narcotic antagonists and that locomotor activity studies can also be used to study the stimulant (agonist) properties of narcotic antagonists.
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  • 34
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    Pflügers Archiv 352 (1974), S. 87-90 
    ISSN: 1432-2013
    Keywords: Calcium ; Warm Receptors ; Cold Receptors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Afferent impulses were recorded from single warm and cold fibers of the cat's infraorbital nerve during thermal stimulation of the nasal area and intravenous injection of calcium ions. Doses of 2 to 8 mg Ca++/kg caused a marked increase in frequency of the warm receptor discharge, followed by a transient decrease, whereas the activity of cold receptor was depressed.
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  • 35
    ISSN: 1432-2013
    Keywords: Rat-Myocardium ; Isometric Tension ; Calcium ; Stimulation Frequeney
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Peak isometric tension was measured in isolated rat papillary muscles at different external calcium levels. Rested state contraction (RSC) tension follows a sigmoid curve when plotted against external calcium concentration [Ca]0. Half maximum tension is given at [Ca]0=0.4 mM. Tension declines with increasing stimulation frequency at [Ca]0=2.5 mM. As [Ca]0 is lowered a positive inotropic response to increasing frequency develops over the range of 20–100/min. Similarly post stimulus potentiation can only be elicited at low [Ca]0 levels. The interactions of [Ca]0 and the inotropic effects of stimulation suggest the presence of a pool of releasable Ca, which can be filled passively at high external calcium levels. When [Ca]0 is lower than about 1.5 mM filling becomes stimulus dependent. The identity of phase-plane plots of contraction cycles following potentiation at low [Ca]0 with those of RSC contractions at higher [Ca]0 levels supports the idea that potentiation at low calcium levels operates by the same mechanism as increasing [Ca]0. The rat myocardium has similar properties to that of other species with respect to inotropic effects of stimulation only when the external calcium is reduced to low levels (0.2–0.4 mM).
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  • 36
    ISSN: 1432-2013
    Keywords: Cardiac Metabolism ; Cardiac Function ; Catecholamines ; High Energy Phosphates ; Calcium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of adrenaline, noradrenaline and isoproterenol on myocardial concentrations of high energy phosphates and function (heart rate,d P/dt max) were investigated in guinea pig heart lung preparations. 1. The catecholamines cause a concentration dependent decrease of myocardial high energy phosphates and the ratios of high energy phosphates to their respective split products. 2. These decreases are not equal to those in the whole animal and do not cause functional imparirment even at extremely high concentrations of catecholamines. The difference in the metabolic actions of the catecholamines in isolated and in situ hearts are discussed in relation to extracardiac alterations induced by catecholamines in whole animals. 3. The metabolic actions of catecholamines are well correlated with functional changes except at high extracellular Ca++-concentrations or, high pressure load and to a certain extent under action of noradrenaline. The changes in high energy phosphate concentrations occurring under these conditions reveal differences between functional and metabolic actions of catecholamines, which can be interpreted to result from more or less pronounced manifestation of primary effects of catecholamines on myocardial energy metabolism.
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  • 37
    ISSN: 1432-2013
    Keywords: Neomycin ; Streptomycin ; Calcium ; Muscle ; Membrane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Experiments were performed on single, isolated muscle fibers of the crabCallinectes danae to investigate the effects of neomycin and streptomycin on membrane Ca++ conductance in relation to excitation-contraction coupling (ECC). Neomycin (2–8 mg/ml) hyperpolarizes the fiber and increases the effective membrane resistance. The antibiotic increases the threshold for, and reduces the amplitude of the graded membrane responses which result from activation of Ca++ conductance on membrane depolarization. Treatment of the fiber with either procaine or tetraethylammonium (TEA) converts the graded responses into regenerative Ca-spikes. Neomycin (2–4 mg/ml) increases spike threshold, reduces the rate of rise of the upstroke and shortens the duration of the action potentials. With higher neomycin concentrations (up to 8 mg/ml) the spikes are abolished. Streptomycin (8 mg/ml) is also capable of blocking Ca-spikes. As a consequence of their effects on membrane Ca++ conductance the antibiotics reduce the mechanical output associated with both graded responses and Ca-spikes. The data support the postulate that membrane Ca++ activation is an essential step in ECC in skeletal muscle.
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  • 38
    ISSN: 1432-2013
    Keywords: Calcium ; Cerebrospinal Fluid ; Regulation of Respiration ; CO2 Sensitivity ; Ventriculocisternal Perfusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In experiments on anaesthetized cats, changes in the calcium concentration of cerebrospinal fluid were induced by means of the ventriculocisternal perfusion technique. A study was performed to evaluate the effects of these changes in calcium concentration on the ventilatory responses to hypercapnia and hypoxia. An increase of the calcium concentration in the perfusion fluid produces a decrease of ventilation and a decrease of the slope of the $$\dot V_{\text{E}} {\text{ - CSF - }}\user2{ }P_{{\text{CO}}_{\text{2}} } $$ curve. The reverse is true down to a concentration of approximately 0.9 mmol×l−1; at lower concentrations the slope either remains constant or decreases. Neither the criticalP a,O 2 at which the ventilatory response to hypoxia starts nor the slope of the $$\dot V_{\text{E}} {\text{ - }}\log \user2{ }P_{{\text{a,o}}_{\text{2}} } $$ P a,O 2 curve is influenced by changing the calcium concentration. We conclude that the calcium concentration of the cerebrospinal fluid influences the sensitivity of the central mechanism for the regulation of respiration to carbon dioxide but not to oxygen. These results point to a central mechanism for the regulation of respiration which is functionally divided into a part which processes impulses from peripheral chemoreceptors and a part which operates as a central chemoreceptor for CO2, or H+; in this concept changes in the calcium concentration exert an influence on the latter part only. The pattern of response of the central chemoreceptors for CO2 closely resembles that of the peripheral chemoreceptors for H+.
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  • 39
    ISSN: 1432-2013
    Keywords: Skeletal Muscle ; Contractility ; Magnesium ; Calcium ; Excitation-Contraction ; Coupling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The penetration of magnesium from high-Mg Ringer's solution into skeletal muscle, and accompanying effects on intrafibre electrolyte composition, muscle contractility and Ca-exchange have been studied in isolated preparations of whole sartorius ofRana temporaria. Muscle magnesium, corrected for extracellular space, rose rapidly and then more slowly, and at 60 min in 20 mM Mg-Ringer it was calculated that intrafibre unbound Mg was increased by at least two-fold over the level in companion muscles in normal Ringer. Contractile response to direct, supramaximal stimulation was reduced in Mg-loaded muscles while resting membrane potential (E m) remained unaffected. Contracture in response to high-K was diminished while caffeine contracture was not changed. Muscles loaded with Mg also showed significant loss of fibre K and gained Na. Mg-loading caused a significant decrease in exchangeability of muscle Ca. Three fractions of exchangeable Ca in muscle were detected, characterised by half-times of circa 1.5, 7 and 50 min, respectively. In muscles soaked in high-Mg Ringer the half-times for these fractions were not different to the controls, but the quantities exchanged in the two slower fractions were reduced.
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  • 40
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    Pflügers Archiv 351 (1974), S. 303-314 
    ISSN: 1432-2013
    Keywords: Node of Ranvier ; Sodium Channel ; Ultraviolet Radiation ; Calcium ; pH ; Membrane Potential
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Isolated nodes of Ranvier were exposed to ultraviolet radiation of 280 nm wavelength under the conditions of different external concentrations of calcium and hydrogen ions. Both Ca++ and H+ sensitize the ultraviolet photoreaction at the nodal sodium system. Within the range of 0.18 to 18 mM [Ca++]e the ultraviolet sensitivity is increased, if [Ca++]e is raised. The increment of sensitivity per tenfold increase of [Ca++]e is 40% of the control value (determined at 1.8 mM [Ca++]e). The sensitizing effect of H+ is approximately half as large as that of Ca++. The ultraviolet sensitivity of the nodal sodium system is increased by 22% of the control sensitivity (determined at pH 7.3) per tenfold increase of [H+]e within the range from pH 7.3 to pH 3.88. However, the sensitization caused by the action of hydrogen ions apparently is restricted to those channels, which are not blocked by protonation, while the population of channels blocked by protonation appears to be partly protected. Their ultraviolet sensitivity is decreased by roughly 7% per tenfold increase of [H+]e. The sensitizing effect of Ca++ and H+ is not due to a screening of negative surface charges at the nodal outside (causing an increase of the electric field strength across the membrane) because hyperpolarizing the membrane protects against ultraviolet radiation. A hyperpolarizing holding potential ofV=−30 mV reduces the ultraviolet sensitivity of the sodium channels to 64±6% of the value measured at a holding potential ofV=0 mV. It is concluded that ultraviolet radiation affects a functional structure of the sodium channel which is related to the outside components of the nodal membrane.
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  • 41
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 148 (1974), S. 381-396 
    ISSN: 1432-0878
    Keywords: Placenta ; Mouse ; Syncytium ; Morphogenesis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé L'origine embryologique des constituants cytologiques de la barrière placentaire chez la Souris a été mise en évidence du 8ème au 11éme jour de la gestation et la séquence des phénomènes favorisant la formation d'un syncytium trophoblastique, précisée. La barrière placentaire trilaminaire a une double origine: la couche interne provient du trophoblaste chorionique, la couche médiane syncytiale comme la couche externe dérivent du trophoblaste ectoplacentaire. Le stimulus initial de la différenciation semble résulter au 9ème jour du contact entre le trophoblaste chorionique et le mésoderme allantoïdien. Quelques heures après, on observe la réaction des cellules chorioniques, caractérisée par une augmentation importante des nucléoprotéines cytoplasmiques, puis l'apparition de globules lipidiques et enfin des propriétés de motilité. Ces cellules établissent des jonctions complexes avec le trophoblaste ectoplacentaire indifférencié qu'elles côtoient. En même temps, le métabolisme nucléaire de ces cellules ectoplacentaires semble modifié. Ultérieurement, au 10éme jour de la gestation, la disparition des membranes plasmiques latérales de ces cellules, conduit à la formation d'un syncytium par fusion de cellules au même stade d'évolution.
    Notes: Summary The morphogenesis of the different layers forming the mouse placental barrier is described during the 8th to 11th day of gestation. The timing and events leading to the formation of the syncytiotrophoblast are analyzed. Two different processes lead to the formation of the hemotrichorial placental membrane: the internal layer is formed by the chorionic trophoblast, both the intermediate syncytial layer and the external cytotrophoblast layer are derived from the ectoplacental trophoblast. The differentiation of the placental barrier begins on the 9th day of gestation by the establishment of contact between the chorionic trophoblast and the allantoic mesoderm. A few hours later, the chorionic cells show a considerable increase in cytoplasmic nucleoproteins and lipids and become ameboid. Complex cell-junctions differentiate between these chorionic cells and the adjacent ectoplacental trophoblast. On the 10th day of gestation the lateral cytoplasmic membranes disappear leading to the formation of a syncytium.
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  • 42
    ISSN: 1432-0878
    Keywords: Neural lobe ; Mouse ; Growth and development ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Nerve fibres of the neurosecretory hypothalamo-hypophyseal tract were studied in embryonic C3H mouse neural lobes; at least four glands at each gestational day 15–19 were examined. Single axons and small bundles of fibres are visible at gestational days 15 and 16. By day 17 large fibre bundles penetrate between glial cells. They increase in number during the next two days. Electron-lucent and electron-dense vesicles are seen in the fibres of the 15th and 16th gestational days. In the 17–19 day-old embryos development is characterized by a successive rise in the number of the two types of vesicles. The mean diameter of the electron-lucent vesicles is approximately unchanged in all the stages examined (50 nm). The electron-dense vesicles increase in size from approximately 80–90 nm at days 15–16 to 140 nm at the 19th gestational day. By day 19 contacts between neurosecretory fibre terminals and the outer basement membrane of internal and peripheral capillaries are occasionally observed. The possibly adrenergic nature of a few terminals contacting peripheral vascular structures in 17 and 18 day-old embryos is suggested.
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  • 43
    ISSN: 1432-0878
    Keywords: Pituitary ; Mouse ; Pars intermedia ; Adrenoglomerulotropin ; Morphometric cytology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural changes in the pars intermedia of the mouse pituitary caused by dietary sodium deprivation were investigated quantitatively. Of the six classes of organelles and inclusions selected for analysis in the pars intermedia cells, only the mitochondria showed no significant changes, while all of the remaining classes showed statistically significant changes. The most conspicuous changes were an abrupt decrease in the number of secretory granules and the appearance of parallel arrays of rough endoplasmic reticulum. The Golgi apparatus also showed hypertrophy accompanied by newly formed granules. The number of vesicles increased temporarily and then decreased. These findings indicate that dietary sodium depletion, a stimulus to greater aldosterone secretion, causes significant changes in the pars intermedia cells within 3 days, and these signs of hyperfunction last up to 5 days. The present study suggests a possible new role of the pars intermedia in the regulation of aldosterone secretion in response to dietary sodium deprivation in the mouse.
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  • 44
    ISSN: 1432-0878
    Keywords: Smooth muscle ; Calcium ; Mitochondria ; Sarcoplasmic reticulum ; Excitation-Contraction coupling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In order to demonstrate the ultrastructural distribution of calcium in smooth muscle cells of the guinea pig taenia coli a precipitation method with potassium oxalate has been used. In addition, morphometric assessment (“stereology”) of cell components and direct quantitative estimation of calcium content in isolated subcellular fractions by atomic absorbtion analyses were carried out. After oxalate treatment smooth muscle cells show four major and distinct sites of calcium oxalate deposition: sarcoplasmic reticulum, mitochondria, cell boundaries (sarcolemma, surface microvesicles) and nucleus. Calcium oxalate deposits were frequently found at the level of close associations formed by different cell organelles. Correlating the morphometric analysis of electron micrographs with microchemical measurements of calcium in isolated subcellular fractions an estimation of calcium content in each cell component of one smooth muscle cell was performed. The nucleus has a significantly higher calcium content than that of any other cellular compartment, but the mitochondria are the main calcium-storage sites of smooth muscle cytoplasm. The highest calcium concentration was found in mitochondria. Although the amount of calcium stored in the sarcoplasmic reticulum represents only about a quarter of that accumulated in mitochondria, around 20% might be enough to produce contraction. On the other hand, the surface microvesicles may accommodate the entire amount of calcium translocated during activity. Functional implications of these findings in relation to the contraction-relaxation cycle are considered and the possible role of the surface microvesicles is discussed.
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  • 45
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 150 (1974), S. 323-329 
    ISSN: 1432-0878
    Keywords: Spermiogenesis ; Mouse ; Multinucleate spermatids ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscope studies of the testes of five inbred and three outbred mouse strains show that the usual frequency of multinucleate spermatids is between one and two percent. In C57 BL/6J and A/Gr however it is higher (4–5%). The frequency of the shared acrosome condition, which would lead to the formation of an abnormal sperm, is 1.3 per thousand.
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  • 46
    ISSN: 1432-1912
    Keywords: 5-HT Synthesis Rate ; MAO Inhibitors ; Probenecid ; Ro4-4602 ; Tryptophan ; Brain ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Non-isotopic and isotopic methods were used to estimate the rate of 5-HT synthesis in the mouse brain. 5-HT and 5_HIAA levels were measured in tissues up to 10 min after the i. p. injection of pargyline (75 or 150 mg/kg) or pheniprazine (5 or 10 mg/kg) (5-HT and 5-HIAA, MAO-inhibitor methods). 5-HIAA levels were also estimated at various times after probenecid administration (200 or 400 mg/kg i. p.) (5-HIAA-probenecid method). 5-HTP levels were estimated at various times after the blockade of 5-HTP decarboxylase by Ro4-4602. (800, 1000 or 1200 mg/kg i. p.) (5-HTP method). Finally the rate of conversion of tryptophan into 5-HT has been estimated by measuring the initial accumulation of 3H-5-HT and 3H-5-HIAA in tissues following the intravenous injection of 3H-tryptophan (isotopic method). Rates of 5-HT synthesis obtained with the two MAO inhibitor methods were much higher (about 3 to 4 times) than those calculated with the 5-HTP and 5-HIAA-probenecid methods. An intermediate rate of 5-HT synthesis was found with the isotopic technique. The high rate of 5-HT synthesis observed with the 5-HT, MAO inhibitor method (about 8 nmoles/g/h) was not related to a stimulation of 5-HT synthesis. Differences seen with all methods are discussed with respect to results obtained by various groups of workers.
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  • 47
    ISSN: 1432-1912
    Keywords: Tolbutamide ; Glibenclamide ; Lipolysis ; Cyclic AMP ; Calcium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Tolbutamide (1 mM) and glibenclamide (0.1 mM) reduced lipolysis due to adrenaline, noradrenaline, isoprenaline, glucagon, and ACTH, whereas theophylline-induced glycerol production was only marginally affected. Furthermore, the effect of dibutyryl cyclic AMP on lipolysis was markedly decreased by low concentrations of both drugs. The antilipolytic action of glibenclamide and, to a smaller degree, of tolbutamide was highly dependent on the calcium concentration in the incubation medium used after preparation of fat cells in the absence of calcium. In the presence of isoprenaline as a lipolytic agent the antilipolytic effect of glibenclamide was progressively enhanced by raising the calcium concentration up to 1.2 mM. Howver, further elevation of calcium to 2.4 mM resulted in a loss of antilipolytic effect. Basal cyclic AMP levels of isolated fat cells were increased twofold by glibenclamide or tolbutamide. In contrast to the effect of glibenclamide, cyclic AMP levels in the presence of isoprenaline were further increased by tolbutamide. Low K m cyclic AMP phosphodiesterase of fat cells was inhibited by tolbutamide as well as by glibenclamide. The results indicate that the antilipolytic action of sulfonylurea drugs is closely related to changes in calcium metabolism but independent of cyclic AMP levels.
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  • 48
    ISSN: 1432-1912
    Keywords: Calcium ; β-Adrenoceptor Blocker ; Adenosine Triphosphatase ; Nucleotides ; Sarcoplasmic Reticulum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The rates of calcium uptake and the calcium dependent increase in ATPase activity of sarcoplasmic reticulum vesicles isolated from rabbit skeletal muscle are reduced in the same ratio by the β-adrenoceptor blocking agents propranolol, pronethalol and Ro-03,3528, but neither by practolol, sotalol nor oxprenolol. The total calcium accumulated was affected by none of the inhibitors. The inhibitory potency of these compounds upon the calcium pump appears to be correlated with their membrane activity or potency as local anaesthetic agents, rather than with their β-adrenoceptor blocking potency. Like the rate of calcium uptake the rate of calcium efflux from the sarcoplasmic vesicles in the presence of ADP, GPD and UDP together with phosphate is inhibited by propranolol and pronethalol.
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  • 49
    ISSN: 1432-1912
    Keywords: Renal Artery ; Nifedipine ; Verapamil ; Smooth Muscle ; Calcium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Intra-arterial infusions of Ca antagonistic vasodilator substances such as nifedipine (1–10 μg/min) and verapamil (30–100 μg/min) inhibited renal autoregulation in the perfused dog kidney. Simultaneous infusion of 30 mg/min of CaCl2 with nifedipine (3 μg/min) or with verapamil (30 μg/min) abolished the effects of these Ca antagonists. It is suggested that Ca ions play an important role in establishing renal autoregulation.
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  • 50
    Electronic Resource
    Electronic Resource
    Springer
    Journal of neurology 206 (1974), S. 117-128 
    ISSN: 1432-1459
    Keywords: Trace elements ; Aging of the brain ; Copper ; Zinc ; Calcium ; Magnesium ; Iron
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In der Frontal- und Occipitalhirnrinde, in Hippocampus, Mandelkern, Striatum, Thalamus, Pallidum, S. nigra, Nucl. ruber, Ncl. dentatus, Oliva inf. und Centrum semiovale wurde die Konzentration von Fe, Zn, Cu, Mg und Ca bestimmt. Bei Fe und Cu konnte ein bestimmtes Verteilungmuster für diese Gebiete ermittelt und statistisch gesicher werden. Für Zn, Ca und Mg waren keine signifikanten regionären Unterschiede nachweisbar. In den untersuchten Altersgruppen ist für diese 5 Elemente eine Altersabhängigkeit nicht erkennbar.
    Notes: Summary The elements iron, copper, zinc, magnesium and calcium were quantitatively determined in several regions of the human brain, including frontal and occipital cortex, hippocampus, n. amygdalae, striatum, thalamus, pallidum, substantia nigra, n. ruber, n. dentatus, oliva inferior and centrum ovale (white matter). Samples were obtained on autopsy from a total of 29 brains at time periods ranging from 12 to 48 hrs after death. Age groups and number of cases (in parentheses) were as follows: 0–2 years (6), 30–40 years (2), 41–50 years (4), 51–60 years (4), 61–70 years (9) and 71–80 years (4). Samples were analysed by means of atomic absorption spectrophotometry following appropriate sample preparation. Results are based on unit dry weight. When the different age groups were compared to each other both the overall means of the five elements studied and the mean concentrations of individual regions remained essentially constant from 31–80 years of age. Values of adult brain were, however, generally higher than those of infant brains (0–2 years of age), changes in levels apparently taking place during infancy and possibly adolescence. Regionally, iron and copper were found to be distributed according to a statistically characteristic pattern; the iron content of the pallidum, putamen, substantia nigra and the caudate nucleus was significantly higher, that of the inferior olive lower when the concentrations of the frontal cortex were arbitrarily used as a reference point. Likewise, copper levels of the substantia nigra were higher, that of the centrum semiovale lower than that of the frontal cortex (P〈0.01). Although no such distinctions could be made regarding the distribution of zinc, magnesium and calcium compared to frontal cortex, the overall regional variation was significant even for these elements when the data were submitted to a one-way analysis of variance (e.g. P〈0.01 for zinc and magnesium). It should be noted that the variance of the means of iron, copper, zinc and calcium was great for some of the anatomical regions, while much less so for others for reasons as yet unknown. The results indicate that in human brain the elements examined undergo little change during adulthood up to the beginning of senescence, and regional differences persist throughout this life span.
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  • 51
    ISSN: 1432-1912
    Keywords: 5,7-Dihydroxytryptamine ; Chemodegeneration ; Adrenergic Nerves ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Injections of 5,7-dihydroxytryptamine (60 mg/kg, i.p.) caused a significant reduction in the noradrenaline content of the mouse heart, large intestine and seminal vesicle, 2 and 6 days after drug application. The long-lasting depletion of noradrenaline was found to be due to a degeneration of adrenergic nerve terminals as verified by fluorescence and electron microscopical observations. The results show that 5,7-dihydroxytryptamine is either as potent as (e.g. in the heart) or less potent than 6-hydroxydopamine (e.g. in the vas deferens) in depleting noradrenaline. The pronounced effects of 5,7-dihydroxytryptamine on the adrenergic nerves of the seminal vesicle (supplied by the same short adrenergic neurones as the vas deferens) suggest that 5,7-dihydroxytryptamine may be used as a tool for the induction of a chemical sympathectomy in certain peripheral organs of laboratory animals, supplementary to 6-hydroxydopamine.
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  • 52
    Electronic Resource
    Electronic Resource
    Springer
    Research in experimental medicine 160 (1973), S. 166-170 
    ISSN: 1433-8580
    Keywords: Parathormon ; Tetracyclin ; Calcium ; Mikroradiographie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Untersuchungen über die Parathormonwirkung im unteren Rattennagezahn ergeben eine initiale, der Parathormonapplikation unmittelbar folgende Erhöhung des Calciumgehaltes im aktuellen Mineralisationsbereich des wachsenden Dentins. Diese Mineralisationssteigerung wird gefolgt von einer Hypomineralisation. Nach kontinuierlicher Parathormonbehandlung ist eine deutliche Störung der Mineralisation zu beobachten.
    Notes: Summary Investigations of the parathormone effect in the lower incisor of the rat show an initially higher calcification in the mineralisation front of growing dentine. This higher mineralisation is followed by a hypomineralisation. After continuous parathormone therapy a distinct disturbance of the mineralisation is noticed.
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  • 53
    ISSN: 1433-8580
    Keywords: Mineralisation ; 85Sr ; Graft ; Bone ; Mouse ; Mineralisation ; 85Sr ; Transplantat ; Knochen ; Maus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Durch wiederholte Messung der 48 Std-Retention von85Sr zu verschiedenen Zeiten nach der Transplantation wurde die Kapazität zur Aufnahme von Erdalkali bei Tibiatransplantaten junger Mäuse unter verschiedenen immunologischen Bedingungen über einen Zeitraum von 36 Tagen nach der Transplantation verfolgt. Bei syngenen Transplantaten war die85Sr-Aufnahme bis zum 10. Tag nach der Transplantation gleich derjenigen der allogenen Transplantate. Danach stieg sie steil an bis zum 17. Tag und blieb bis zum Ende des Versuchs (36 Tage nach Transplantation) auf dem Niveau der Empfängertibia. Sowohl syngen als auch allogen transplantierte Tibiae zeigten nach der Transplantation eine etwa gleichstarke Zunahme der Aschegewichte.
    Notes: Summary In growing tibia transplants of the mouse the 48-hour uptake of85Sr was determined. With allogeneic grafts the uptake was continuously low during 32 days after transplantation. With syngeneic grafts uptake was low up to the 10th day after grafting. After 17 days, however,85Sr uptake was higher than that of allogeneic ones. Ashweights of both groups of transplants were higher at the end of the experiment than at the time of grafting.
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  • 54
    ISSN: 1432-0568
    Keywords: Cleavage stages ; Egg-cylinder ; Mouse ; Rat ; Hydrolytic enzymes distribution ; Differentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The time of appearance and the distribution of alkaline and acid phosphatase and nonspecific esterase was investigated in cleavage and early postimplantation stages of mouse and rat embryos. Alkaline and acid phosphatase appeared for the first time in 8-cell embryos. Activity of both enzymes grew progressively stronger to blastocyst stage. Acid phosphatase activity was revealed in the form of fine and coarse granules distributed evenly in the cytoplasm. Alkaline phosphatase was predominantly localized in plasma membranes. There was no difference in intensity of reaction between trophoblastic cells and the inner cell mass. After implantation acid phosphatase was localized in coarse granules in the apical portion of entodermal cells. With the appearance of mesoderm, the cells of embryonal entoderm became flattened and devoid of acid phosphatase activity which was restricted to cells of extraembryonic entoderm. The activity of nonspecific esterase was not detected in preimplantation stages. In postimplantation embryos it roughly corresponded to the activity of acid phosphatase. Alkaline phosphatase was localized in cell membranes of ectodermal cells. The mesodermal cells of mouse embryo displayed a somewhat weaker activity than ectodermal cells, while in the rat embryo the same layer remained completely nonreactive. Our findings on the distribution of the enzymes mentioned did not reveal any kind of polarity or bilateral symmetry in preimplantation stages. In postimplantation stages acid phosphatase and nonspecific esterase are probably bound to lysosomes and play an important role in embryonic nutrition. The absence of alkaline phosphatase from entodermal cells is somewhat puzzling and suggests that the process of molecular transport in those cells is most probably restricted to endocytosis. Our results suggest that all blastomeres are identical with respect to enzyme distribution and that the first signs of differentiation of enzyme content appear with the formation of germ layers.
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  • 55
    ISSN: 1432-0568
    Keywords: Lymphocytes ; Thymus ; Karyometry ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Karyometric studies were made of lymphocytes for the cortex and medulla of the thymus of mice at various ages from birth to adulthood. From the results obtained it was evident that in early neonate mice, medullary small lymphocytes were characterized by having larger nuclei than cortical small lymphocytes. On the basis of cytological features, such medullary lymphocytes could reasonably be classified as small lymphocytes rather than medium lymphocytes, although they had larger nuclei than typical small lymphocytes. Such peculiar small lymphocytes with larger nuclei were preponderant in the medulla during early neonatal life, but they rapidly decreased in number with advancing age, although they were present in a small proportion even in adults. The findings on the occurrence of such peculiar small lymphocytes in the medulla were discussed in relation to the maturation pathway of lymphocytes in the thymus.
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  • 56
    ISSN: 1432-0568
    Keywords: Peroxisomes ; Microbodies ; Catalase ; Ciliated cells ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Flimmerepithel aus Respirationstrakt (Nasenseptum, Trachea) und Tube der Maus wurde untersucht. Nach Fixierung in 5% nicht destilliertem Glutaraldehyd wurde das Gewebe zur Darstellung der peroxydatischen Aktivität von Katalase in einem alkalischen Medium (pH 8,0 und 9,5) von 0,2% DAB und 0,02% H2O2 inkubiert. In den Flimmerzellen wird durch die histochemische Reaktion die granuläre Matrix kleiner Zellorganellen elektronendicht dargestellt. Diese Organellen sind im Schnitt rund, oval oder tubulär; Sie werden von einer Einheitsmembran begrenzt. Die Größe ihrer kurzen Durchmesser schwankt zwischen 0,1 und 0,2 μm. Schlauchförmige Partikel sind bis 1 μm lang. Die histochemische Reaktion wird durch 2×10−2 M 3-Amino-1,2,4-Triazol im Inkubationsmedium gehemmt und fehlt, wenn ohne H2O2 im Medium inkubiert wird. Die Interpretation dieser Organellen als echte Peroxysomen einzig auf Grund ihres Katalasegehalts wird diskutiert. Um den Forderungen des von de Duve entwickelten Peroxysomenkonzepts zu genügen, wäre der Nachweis von H2O2 erzeugenden Oxydasen Voraussetzung. Bis dahin muß der Terminus Peroxysom für Partikel, in denen nur Katalase nachgewiesen ist, als Arbeitshypothese aufgefaßt werden.
    Notes: Summary Ciliated cells in the epithelium of the respiratory tract (septum nasi, trachea) and oviduct of mice were investigated. The tissue was fixed in 5% undistilled glutaraldehyde and incubated in an alkaline (pH 8.0 and pH 9.5) medium containing 0.2% DAB and 0.02% H2O2, to demonstrate the peroxidatic activity of catalase. In ciliated cells the granular matrix of small cell organelles is intensely stained by the histochemical method used. These particles are round, oval or tubular in shape, they are limited by an unit membrane. Their short axes measure from 0.1 to 0.2 μm. Tubular shaped particles are up to 1 μm long. The histochemical staining reaction is abolished by the addition of 2×10−2 M 3-amino 1,2,4-triazole to the incubation medium or if H2O2 is omitted from the medium. The interpretation of these particles as true peroxisomes on account of their catalase content only is discussed. It is concluded that the demonstration of peroxide producing oxidases would be necessary to satisfy the conditions of the peroxisome concept, which was proposed by de Duve. So far, the term peroxisome for particles which are only demonstrated to contain catalase, must remain a working hypothesis.
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  • 57
    ISSN: 1432-0568
    Keywords: Retina ; Mouse ; Photoreceptors ; Differentiation ; rd Mutant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Mice, homozygous for the mutant gene rd show selective degeneration of the photoreceptor cells after their initial differentiation. Phenotypic expression in the mutant and in normal mice was studied by light and electron microscopy. The sequential emergence of developmental deviations in the mutant retina falls into three categories. First, predegenerative differences are manifest within the photoreceptor cells during 4–8 days after birth in retarded growth of the inner segments, reduced outer segment production, delayed development of the outer plexiform layer and slower segregation of the perikarya. Next, degenerative changes are recognized from 6 day onwards with swelling and vacuolization of the Golgi cisternae in the inner segments followed by cytolytic alterations affecting the ultrastructure of the entire cell. Lastly, with increasing loss of photoreceptor cells post-degenerative effects are seen in deepening of the basal infoldings and microvilli of the pigment epithelium and increase of Müller's fibres. The progress of degeneration in the mutant retina corresponds to the phase of rapid growth of the Golgi apparatus and rod outer segments in the normal retina. The role of the Golgi apparatus in the differentiation of the photoreceptor cells and its relation to the expression of the rd gene are discussed.
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  • 58
    ISSN: 1432-0428
    Keywords: Calcium ; EDTA ; glucose tolerance ; insulin ; uraemia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of calcium infusion on the intravenous glucose tolerance was tested in hypocalcaemic patients suffering from renal insufficiency. It was shown that the delayed glucose disappearance rate in uraemics could be improved (p 〈 0.005) by the infusion of calcium gluconolactobionate despite the fact that the serum concentrations of potassium, urea nitrogen, and the blood pH were not altered. The basal insulin concentration was significantly depressed by the calcium infusion (p 〈 0.02). The serum calcium concentration was significantly correlated to the glucose assimilation coefficient in the uraemic patients (p 〈 0.01). — 3 hypocalcaemic patients without renal failure had a normal glucose tolerance and a normalization of the serum calcium concentration had no discernable effect. — A slight but significant decrease of the serum calcium concentration (p 〈 0.01) by EDTA-Na2 in normocalcaemic patients did not change the intravenous glucose tolerance. — It is concluded that hypocalcaemia may be one of the causes for the abnormal glucose tolerance in chronic renal failure.
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  • 59
    ISSN: 1432-0827
    Keywords: Muscles ; Calcium ; Atrophy ; Excercise
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Un état pathologique est produit au niveau des muscles squelettiques en immobilisant l'arrière-train de rats à l'aide de plâtre de Paris. Après 4 semaines d'immobilisation, la concentration en calcium augmente au niveau des trois types de fibres des parties immobilisées. Le muscle non immobilisé d'un rat en présente pas d'augmentation significative de la concentration en calcium, lorsque d'autres membres du même rat sont immobilisés. Le pourcentage d'augmentation du calcium dans les muscles squelettiques, après immobilisation, pourrait être en rapport avec la diminution absolue d'activité musculaire par rapport aux témoins.
    Abstract: Zusammenfassung Durch die Immobilisierung beider Hinterbeine der Ratte mittels Gips wurde in den Skeletmuskeln ein Zustand der Verkümmerung hervorgerufen. Nach 4wöchiger Immobilisierung nahm die Calciumkonzentration in den drei verschiedenen Fasertypen des immobilisierten Hinterbeines zu. Der nicht-immobilisierte Muskel einer Ratte zeigte keine bedeutende Zunahme der Calciumkonzentration, wenn andere Glieder derselben Ratte stillgelegt wurden. Die prozentuale Zunahme an Calcium im Skeletmuskel nach der, Immobilisierung kann mit der absoluten Herabsetzung der Muskeltätigkeit im Vergleich mit Kontrollen in Zusammenhang gebracht werden.
    Notes: Abstract A state of disuse was produced in skeletal muscle by immobilizing both hindlimbs of the rat with plaster of paris. After 4 weeks of immobilization, the calcium concentration increased in the three different fiber types of the immobilized hindlimb. The non-immobilized muscle of a rat showed no significant increase in calcium concentration when other limbs of the same rat were fixed immobile. The percentage increase in calcium within skeletal muscle after immobilization may be related to the absolute reduction in muscular activity from control levels
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  • 60