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  • Bone  (48)
  • Scanning electron microscopy  (48)
  • Springer  (93)
  • International Union of Crystallography
  • 1995-1999
  • 1980-1984
  • 1975-1979  (93)
  • 1925-1929
  • 1978  (27)
  • 1977  (49)
  • 1976  (17)
Collection
Keywords
Publisher
  • Springer  (93)
  • International Union of Crystallography
Years
  • 1995-1999
  • 1980-1984
  • 1975-1979  (93)
  • 1925-1929
Year
  • 1
    Electronic Resource
    Electronic Resource
    Isolation of osteoclasts by velocity sedimentation at unit gravity (1977)
    Springer
    Calcified tissue international 22 (1977), S. 303-313 
    Details
    ISSN: 1432-0827
    Keywords: Osteoclasts ; Sedimentation ; Isolation ; Cells ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract A method is presented for separating osteoclasts from the heterogeneous population of bone and marrow cells. Cell suspensions were prepared from femora of young rabbits by mechanical dispersion. The starting cell suspension typically contained only 1.0%±0.5 osteoclasts. Following an initial 45 min of unit gravity sedimentation in a lucite chamber osteoclasts were primarily distributed in fractions 2–5. A second 45-min sedimentation of these pooled fractions yielded cell suspensions containing greater than 30% osteoclasts (as much as a 50-fold increase over starting percentages). Linear scan analysis, however, revealed that osteoclasts accounted for 73.14%±0.58 of the cell colume. Subsequent in vitro experiments demonstrated linear incorporation of3H-leucine into TCA precipitable protein for cells comprising the osteoclast fraction. Concomitant radiautographs revealed radioactive label in isolated osteoclasts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02010369
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  • 2
    Electronic Resource
    Electronic Resource
    The comparative effects of dichloromethylene diphosphonate (Cl2MDP) and ethane-1-hydroxy-1,1-diphosphonate (EHDP) on growth and modeling of the rat tibia (1977)
    Springer
    Calcified tissue international 23 (1977), S. 207-214 
    Details
    ISSN: 1432-0827
    Keywords: Bone ; Diphosphonates ; Bone resorption ; Bone formation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Male rats weighing 100 g were assigned to groups and injected daily for 10 days with vehicle (control), 0.4, 2.0, 4.0, 10.0, or 20.0 mg/kg/day of ethane-1-hydroxy-1,1-diphosphonate (EHDP) or dichloromethylene diphosphonate (Cl2MDP). The proximal tibial metaphysis and epiphysis were assayed for changes in percentage of hard tissue and bone formation parameters. From the data, information about hard tissue resorption was deduced. All doses of Cl2MDP and doses of 2.0 mg EHDP/kg/day and greater caused significant increases in percentage of hard tissues with Cl2MDP being more effective than similar doses of EHDP in decreasing bone resorption. Osteoclast population parameters were increased with all doses of both Cl2MDP and EHDP with Cl2MDP having a greater effect than similar doses of EHDP. Decreases in the proliferation of the osteoprogenitor pool parallel the decreases in osteoblasts and bone formation parameters. These decreases in osteoprogenitor pool proliferation do not account for the increases with diphosphonates in osteoclast population parameters.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02012787
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  • 3
    Electronic Resource
    Electronic Resource
    Quantitative analyses of osteoclast changes in resorbing bone organ cultures (1977)
    Springer
    Calcified tissue international 23 (1977), S. 283-289 
    Details
    ISSN: 1432-0827
    Keywords: Bone ; Resorption ; Osteoclast ; Quantitation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The stimulation of bone resorption, assessed by the release of45Ca from prelabeled bones, was associated with an increase in number of osteoclasts per bone section in parathyroid hormone (PTH)-treated bones, but not in lipopolysaccharide (LPS)-treated bones. By contrast the number of nuclei per osteoclast increased following LPS treatment, but was not affected by PTH. LPS-treated bones had more multinucleated cells, some having as many as 27 nuclei per osteoclast. More osteoclasts were adjacent to the bone collar in bones treated with LPS or PTH than in control bones. In LPS-treated bones this area also contained the largest osteoclasts, as determined by the greatest number of nuclei per osteoclast. The results suggest that LPS and PTH stimulate osteoclastic resorption by different mechanisms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02012798
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  • 4
    Electronic Resource
    Electronic Resource
    Preliminary studies on the binding of plasma albumin to bone tissue (1977)
    Springer
    Calcified tissue international 23 (1977), S. 303-305 
    Details
    ISSN: 1432-0827
    Keywords: Albumin ; Bone ; Hydroxyapatite ; Plasma protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The extractability of125I-labelled plasma albumin from bone pieces and from powdered bone has been compared after both in vivo and in vitro incorporation. The results show that albumin is more readily extracted from bone pieces than from bone powder which implies that tissue disruption exposes additional protein adsorption sites. It is suggested that incorporation of plasma albumin into calcified matrix during bone formation occurs mainly as a result of its strong interaction with bone mineral.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02012801
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  • 5
    Electronic Resource
    Electronic Resource
    Cortical bone remodeling in normal rat (1977)
    Springer
    Calcified tissue international 23 (1977), S. 161-170 
    Details
    ISSN: 1432-0827
    Keywords: Bone ; Growth ; Rat ; Remodeling ; Tetracyclines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Cortical bone remodeling along the femur diaphysis was determined in normal female rats (Sprague-Dawley) with the tetracycline technique. Three segments on the cortical bone circumference (the anterolateral, the medial, and the posterior) were found to be most suitable for the study of the remodeling process. Oxytetracycline was administered at age 60 and 75 days, and groups of animals were killed at age 75, 85, 95, and 105 days. The accumulated endosteal growth during age 60 to 75 days in the anterolateral segment was found to increase uniformly in the distal direction along the femur diaphysis. A method is described where this accumulated endosteal growth is used. This method eliminates the use of calipers to determine the section level and makes it possible to study comparable sections even after varying periods of time. The proximal part of the diaphysis showed periosteal apposition in all three segments. The periosteal apposition turned into resorption in the distal part of the diaphysis in the anterolateral and medial segments, whereas the periosteal appsition increased in the posterior segment. The endosteal growth increased in the distal direction in the anterolateral and medial segments. Irregular OTC bands made measurements of endosteal remodeling in the posterior segment impossible. The cortical width decreased in the distal direction along the femoral shaft. Comparison between the different age groups is described and also the relation between the accumulated endosteal growth and the diameter of the medullary cavity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02012782
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  • 6
    Electronic Resource
    Electronic Resource
    Bone water (1977)
    Springer
    Calcified tissue international 23 (1977), S. 1-5 
    Details
    ISSN: 1432-0827
    Keywords: Water ; Bone ; Homeostasis ; Structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary A short review is given of the water in bone. Various analyses of bone water content are discussed, and its possible location is considered in relation to the behaviour of water in isolated components of bone. Some of the difficulties encountered in examining such microscopic phenomena as water structure in a heterogeneous system such as bone are also discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02012759
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  • 7
    Electronic Resource
    Electronic Resource
    Mechanism of induction of hypercalcemia and hyperphosphatemia by lead acetate in the rat (1977)
    Springer
    Calcified tissue international 24 (1977), S. 41-46 
    Details
    ISSN: 1432-0827
    Keywords: Lead salt ; Bone ; Mobilization ; Hypercalcemia ; Hyperphosphatemia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The present study is an investigation of the mechanism of hypercalcemia and hyperphosphatemia induced by the intravenous injection of lead acetate (Pb-Ac). A total of 118 male rats were injected with 30 mg/kg of Pb-Ac, or with 16.5 mg/kg of sodium acetate as the control. The levels of serum calcium, phosphorus and lead were then determined at various time periods after the injections. Serum calcium and phosphorus levels increased with time after Pb-Ac injection and the maximum values of calcium (17 mg%) were found after 1 h and of phosphorus (13.5 mg%) after 30 min. Both calcium and phosphorus levels reverted to the normal range after 12 h. The maximum net rates of increase of calcium and phosphorus were found immediately after Pb-Ac injection. At that time, deposition of lead at the calcifying sites of bone and incisor dentin was demonstrated by a histochemical examination. In other experiments the changes in the calcium and phosphorus contents in the medium after shaking bone powder in serum with Pb-Ac in an in vitro system were studied. It was confirmed that the calcium and phosphorus were displaced from the bone mineral, the extent of the displacement being correlated with the concentration of the Pb-Ac added to the medium, and that these displacements were very rapid reactions. These results suggest that hypercalcemia and hyperphosphatemia following Pb-Ac injection results from a direct action of lead on the bone mineral.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02223295
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  • 8
    Electronic Resource
    Electronic Resource
    Effect of endogenous and infused parathyroid hormone on plasma concentrations of recently administered45Ca (1977)
    Springer
    Calcified tissue international 24 (1977), S. 209-214 
    Details
    ISSN: 1432-0827
    Keywords: Parathyroid hormone ; Plasma calcium ; Radiocalcium ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The net rate of loss of45Ca from plasma was monitored in normal, thyroparathyroidectomized (TPTX), and nephrectomized rats. Also studied was the effect of a 24 h intravenous infusion of PTH in TPTX rats. The45Ca was injected after an overnight fast and 1 to 4 h prior to the time the first blood sample was obtained. In normal rats, the net rate of loss of45Ca from plasma was slower than in TPTX rats for at least 12 h after radionuclide injection. Nephrectomy did not affect this difference between control and TPTX rats until 8 h after45Ca injection or about 18 h after nephrectomy. At this time a reversal occurred and the net rate of plasma45Ca loss in nephrectomized rats with parathyroids became faster than in TPTX nephrectomized rats. When PTH was infused at a constant rate (3 mU/g body weight/h) plasma calcium concentrations rose gradually for approximately 12 h after which a constant plasma calcium level was maintained with continued PTH infusion. During the period when plasma calcium concentrations were rising, the net rate of loss of45Ca from plasma was slower than in TPTX controls infused only with saline. However, when plasma levels stabilized, plasma45Ca disappearance rates changed such that the rate loss of45Ca from plasma became faster in PTH-infused than in TPTX controls. It is concluded that PTH increases calcium efflux from the same compartment in bone which receives calcium from plasma, thereby returning some recently deposited45Ca to plasma. In the non-equilibrated state, this returns additional45Ca to plasma causing anet decrease in the rate of loss of45Ca from plasma. However, in the equilibrated condition, when both calcium efflux from bone and influx into bone are in balance but at higher flux rates, PTH stimulates the diffusion of45Ca into other bone compartments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02223318
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  • 9
    Electronic Resource
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    Scanning electron microscope study of separated calcospherites from the matrices of different mineralizing systems (1978)
    Springer
    Calcified tissue international 26 (1978), S. 47-49 
    Details
    ISSN: 1432-0827
    Keywords: Matrix vesicles ; Calcospherites ; Mineralization ; Bone ; Dentin ; Cartilage ; SEM
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Mineral particle cluster, corresponding to calcospherites or matrix vesicle-initiated clusters in calcifying cartilage and dentin and to collagen bundle-related mineralization in lamellar bone, have been isolated from NaOCl solutions used to dissolve the organic matrix in preparation of anorganic mineralizing fronts for scanning electron microscopy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02013233
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  • 10
    Electronic Resource
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    Mechanism of osteoclastic bone resorption: A new hypothesis (1978)
    Springer
    Calcified tissue international 26 (1978), S. 81-84 
    Details
    ISSN: 1432-0827
    Keywords: Osteoclasts ; Bone ; Resorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Osteoclastic bone resorption involves the solubilization of the mineral salts and the degradation of noncollagen bone matrix and collagen fibrils. As no recognizable collagen fibrils have ever been reported within cytoplasmic vacuoles in osteoclasts, it is generally assumed that the collagen fibrils are digested extracellularly in the resorption zone. The extent to which lysis occurs extracellularly and whether or not the osteoclasts phagocytose the degradation products remain to be established. In the present communication, a hypothesis is presented suggesting the possibility that osteoclastic resorption of bone involves the participation of two different cell types. According to this hypothesis, osteoclastic bone resorption is initiated by osteoclasts that demineralize areas of bone and degrade noncollagen bone matrix. After the osteoclasts have moved away or become partially detached from the demineralized site, the exposed collagen fibrils are phagocytosed by mononuclear, fibroblast-like or monocyte-derived cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02013238
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  • 11
    Electronic Resource
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    Plasma disappearance of rabbit α2 HS-glycoprotein and its uptake by bone tissue (1978)
    Springer
    Calcified tissue international 26 (1978), S. 155-161 
    Details
    ISSN: 1432-0827
    Keywords: Plasma protein ; Glycoprotein ; Bone ; Glucosamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Plasmaα 2HS-glycoprotein is specifically accumulated in calcified tissues. In the present studies this glycoprotein was isolated from plasma and after iodination with iodine-125 was injected intravenously into young rabbits. The tissue distribution and plasma disappearance rate of this radioactively labeled material were determined. Of the various tissues studied, bone showed the greatest retention of labeled glycoprotein expressed as percentage of the injected dose per gram tissue relative to the plasma content. The rate of loss of iodinatedα 2HS-glycoprotein from plasma was similar to that ofα 2HS-glycoprotein labeled endogenously by using14C-glucosamine or3H-glucosamine. The uptake of exogenously labeled3I-α 2HS-glycoprotein into bone tissue expressed as a percentage of the injected dose was similar to that of endogenously labeled14C-α 2HS-glycoprotein. These results suggest that the125I-labeled material can be used to study further the metabolism ofα 2HS-glycoprotein by bone tissue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02013251
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  • 12
    Electronic Resource
    Electronic Resource
    Effect of mithramycin on boneβ-glucuronidase and resorption (1978)
    Springer
    Calcified tissue international 26 (1978), S. 209-213 
    Details
    ISSN: 1432-0827
    Keywords: Mithramycin ; Bone ; β-Glucuronidase ; KT medium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Mithramycin suppresses bone resorption. Its effect on the synthesis and release of β-glucuronidase (a referent for lysosomal enzymes) in mouse calvarial explants was studied in an in vitro culture system. A newly described medium (designated as KT medium) was introduced in this specific study. Mithramycin initially inhibited the release of β-glucuronidase into the medium and resulted in an ultimate accumulation of this enzyme in the bone. These results suggest that inhibition of bone resorption by mithramycin may be attributed to interference in release of lysosomal enzymes from bone cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02013260
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  • 13
    Electronic Resource
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    SEM analysis of amphibian mesodermal migration (1977)
    Springer
    Development genes and evolution 181 (1977), S. 31-40 
    Details
    ISSN: 1432-041X
    Keywords: Cell migration ; Mesoderm ; Gastrulation ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary At the end of gastrulation, the lateral mesoderm of amphibian embryos migrates ventrally between the ectoderm and the endoderm. The present study is an examination of the morphology of the leading cells of the mesodermal sheet and of the substratum over which they move (the inner surface of the ectoderm). The cells of the leading edge of the mesoderm are generally round, with very short and narrow flattened projections in the forward direction. These projections do not have a “ruffled” morphology, regardless of whether fixation is carried out before or after the ectoderm and mesoderm are dissected away from the endoderm. The inner surface of the ectoderm is covered with fine (450–500A) filamentous extracellular material and the ectoderm cells sometimes extend cytoplasmic processes (approx. 0.1 μ wide) onto the leading surface of the mesoderm or onto adjacent ectoderm cells. These studies indicate that the morphology of cell migration in amphibians is closer to that seen inFundulus than to that characteristic of chick or mammalian cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00857266
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  • 14
    Electronic Resource
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    Matrix vesicles in newly synthesizing bone observed after ultracryotomy and ultramicroincineration (1977)
    Springer
    Calcified tissue international 23 (1977), S. 185-188 
    Details
    ISSN: 1432-0827
    Keywords: Matrix vesicles ; Bone ; Ultracrytomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Matrix vesicles were observed in femurs of 8-day-old chick embryos prepared by ultracryotomy. Some of the sections were subjected to ultramicroincineration. The unfixed tissues never came into contact with solutions, and thereby artifacts due to dissolution, redistribution, or rearrangement of the mineral constituents were avoided. In the osteoid, electron dense objects with the size and appearance of matrix vesicles were seen, although limiting membranes were not visible. After ultramicroincineration the vesicles were observed to contain small crystals and a less dense amorphous mineral material which may be the precursor of bone mineral. In addition, a ring of ash enclosed the crystalline and amorphous mineral and appeared to occupy the position of the vesicle membrane as seen in conventionally prepared material.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02012785
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  • 15
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    Magnesium and the mineral metabolism of chick embryo tibiae in organ culture (1977)
    Springer
    Calcified tissue international 24 (1977), S. 93-98 
    Details
    ISSN: 1432-0827
    Keywords: Magnesium ; Bone ; Mineral ; Chick embryo ; Organ culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Using bone organ culture techniques, three concentrations of magnesium were evaluated for their effects on the mineral mass of embryonic chick tibiae incubated for 3 days with or without a metabolic inhibitor (1 mM iodoacetic acid) added to the media. Varying the medium Mg level from 0.3 to 3.0 mM had little effect on the net increase in mineral in live bones (without the inhibitor), but in dead tibiae (with the inhibitor) there was a marked net decrease in mineral deposition with increasing Mg concentration. Bone Mg mass varied directly with the level of Mg in the medium regardless of whether or not the tibiae were inhibited. Responsiveness to parathyroid hormone (PTH) with regard to mineral loss and increased lactate production was not affected by Mg even in tibiae incubated in Mg-free media. However, PTH-treated bones cultured in Mg-free media had a significantly elevated Mg mass, suggesting that the hormone may have a Mg-conserving effect on bone during severe Mg deficiency. The findings of this study support the hypothesis that bone cells regulate the level of Mg to which newly forming mineral is exposed and that PTH-responsiveness in embryonic chick tibiae is not dependent on the ambient Mg concentration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02223301
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  • 16
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    The effect of fluoride on bone of rats fed diets deficient in calcium or phosphorus (1977)
    Springer
    Calcified tissue international 22 (1977), S. 9-17 
    Details
    ISSN: 1432-0827
    Keywords: Bone ; Fluoride ; Calcium ; Phosphorus ; Mechanical Strength
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Four groups of weanling rats were fed for 2 weeks on a diet sufficient or insufficient in calcium and/or phosphorus. Each group was divided into four subgroups which were offered distilled water supplemented with 0, 50, 75, or 150 ppm fluoride. High levels of fluoride in drinking water inhibited weight gain. This inhibition was less in rats deficient in phosphorus than when normal-phosphorus diets were offered. At a low level, fluoride was without any effect on bone ash, thickness of femoral cortical bone, and mechanical strength, as measured by maximal load, ultimate stress to breaking, and limit of elasticity. Modulus of elasticity was decreased. At higher levels fluoride tended to decrease most of these parameters, except in rats deprived of both calcium and phosphorus. The effect of fluoride was modified by lack of dietary calcium and/or phosphorus and appeared to be weaker in rats deficient in these nutrients. Lack of dietary calcium and/or phosphorus decreased bone strength more than did fluoride content of water and of bone mineral. Concentration of bone ash and thickness of femoral cortical bone were closely correlated with parameters of mechanical strength.
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    URL: http://dx.doi.org/10.1007/BF02010341
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  • 17
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    An interpretation of acute changes in plasma45Ca following parathyroid hormone administration to thyroparathyroidectomized rats (1977)
    Springer
    Calcified tissue international 22 (1977), S. 117-128 
    Details
    ISSN: 1432-0827
    Keywords: Parathyroid hormone ; Plasma calcium ; Radiocalcium ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Acute changes in plasma calcium and45Ca were studied in young adult male thyroparathyroidectomized (TPTX) rats injected with moderate doses of parathyroid hormone (PTH). For plasma calcium changes, comparison was made between rats fasted or fed prior to PTH injection. For plasma45Ca changes, the effect of the time of administration of the radionuclide was also studied; this included rats injected with PTH 1 h after radionuclide (“1 h45Ca”), 18 h later (“18 h45Ca”) and more than 6 days later (“6 day45Ca”). The results can be summarized as follows: (1) Plasma calcium changes were greater when PTH was injected into “fed” rather than into “fasted” rats. (2) PTH always produced a relative increase (compared to controls tested concurrently) in plasma45Ca concentrations. This increase was the same in the “1 h45Ca” and the “18 h45Ca” groups. (3) Plasma45Ca rose at least temporarily following PTH injection in the “18 h45Ca” group. (4) The45Ca rise following PTH was always greater in “fed” than in “fasted” groups. (5) Plasma45Ca specific activities (S.A.) tended to rise in the “6 day45Ca” group and to fall in the “18 h45Ca” group, following PTH injection. However, the45Ca S.A. was always higher in fed than fasted groups. (6) In a few experiments in which32P was injected with45Ca, specific activity changes in plasma45Ca following PTH injection werenot accompanied by similar changes in32P specific activity. These results could not be adequately explained by PTH effects on bone resorption, but the data supported the postulate that PTH controls plasma calcium concentrations by increasing transport of calcium through the osteocyte-lining cell (osteoblast) bone cell complex from the bone fluid compartment to the ECF.
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    URL: http://dx.doi.org/10.1007/BF02010351
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  • 18
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    On the state of anionic groups of demineralized matrices of bone and dentine (1977)
    Springer
    Calcified tissue international 22 (1977), S. 275-284 
    Details
    ISSN: 1432-0827
    Keywords: Bone ; Calcium ; Collagen ; Dentine ; Phosphoprotein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Calcium-binding and biochemical studies have been applied to characterize the state of the carboxylate and protein-bound phosphate groups in the EDTA-demineralized matrices of rat bone and dentine. The organic phosphate and carboxylate content of demineralized bone is virtually identical to that of purified steer skin collagen whereas demineralized dentine has a significantly higher phosphate and carboxylate content, presumably due to the presence of an acidic non-collagenous phosphoprotein. Two classes of calcium-binding sites can be detected in demineralized bone, demineralized dentine, and purified, reconstituted collagen. The number of strong calcium-binding sites correlates with the number of protein-bound phosphate groups. Depending on the preparative procedure, seven to nine such sites (per collagen molecule) are present in dentine, and one to two in the purified reconstituted collagen and in bone. The binding constant for the dentinal sites (1.1×104 M−1), however, is 20 times greater than that for bone or reconstituted collagen fibrils from skin. We tentatively conclude that the strong calcium-binding site in bone and reconstituted collagen is of the form protein-PO 4 − Ca++ whereas in dentine it is of the form the weak binding sites in bone and dentine are of the form protein-COO-Ca++; and that approximately 160 of the 217 carboxylate groups of the collagen molecules of dentine or bone are present as electrostatic linkages of the form protein-COO−+H3N-protein.
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    URL: http://dx.doi.org/10.1007/BF02010366
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  • 19
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    Strain related electrical potentials recorded in vitro and in vivo (1977)
    Springer
    Calcified tissue international 22 (1977), S. 315-327 
    Details
    ISSN: 1432-0827
    Keywords: Bone ; Bioelectricity ; Strain ; Locomotion ; Osteoporosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Using wet dead specimens it was possible to show that the size and form of strain-related electrical potentials on the surface of sheep radii were related both to the amount of strain, and the strain rate, over the range of these recorded during locomotion. Using the same electrode and amplifier system in vivo changes in surface strain and surface charge were recorded from the radius of three sheep during locomotion. During slow locomotion electrical changes were negligible. At medium speed they were most variable, and profoundly influenced by small alterations in the timing and pattern of strain change. When locomotion was fast the electrical waveform reflected fairly faithfully the changes in strain on the bone surface.
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    URL: http://dx.doi.org/10.1007/BF02010370
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  • 20
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    Bone mineral content in the forearm after fracture of the upper limb (1977)
    Springer
    Calcified tissue international 22 (1977), S. 329-331 
    Details
    ISSN: 1432-0827
    Keywords: Bone ; Fracture ; Mineral
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract The bone mineral content was measured by gamma absorptiometry in patients who had sustained fractures of the upper limb. Measurements were taken on the shafts of the forearm and in the trabecular bone immediately proximal to the wrist. Fractures of the surgical neck of the humerus and fractures of the shaft of the humerus did not significantly influence the bone mineral content of the ipsilateral forearm. Fracture of the radius and the ulna, however, caused a 15% loss of the bone mineral content in the trabecular bone proximal to the wrist, whereas the mineral content on the shafts of the fractured forearms increased or decreased depending on the fracture site. The findings suggest that measurements of bone mineral content of the forearm are not necessarily invalidated if there has been a fracture of the same limb. Only if the forearm itself is fractured should measurements on this site be avoided.
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    URL: http://dx.doi.org/10.1007/BF02010371
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    Radiogenic free radicals as molecular probes in bone (1978)
    Springer
    Calcified tissue international 25 (1978), S. 37-43 
    Details
    ISSN: 1432-0827
    Keywords: ESR ; Radiation free radicals ; CO3-Apatites ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Exposure of bone mineral to X-rays generates free radicals. These are usually very labile, but can be stabilized at liquid nitrogen temperatures for study by electron spin resonance spectroscopy. The free radicals thus detected in the present study included one with resonances arising from an electron excess center and 2 species with electron-deficit centers: a phosphate anion radical and a radical associated with carbonate. Each of these radicals seemed to be located chiefly at the mineral surface and was sensitive to the surface environment. Presence of an organic phase, as in whole bone, modified free radical production in a manner that suggests interference with the formation of electron deficit centers. Comparison with other synthetic minerals suggests that precipitated carbonateapatites are good models for bone mineral.
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    URL: http://dx.doi.org/10.1007/BF02010749
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    The ultrastructure of the extracellular phase of bone as observed in frozen thin sections (1977)
    Springer
    Calcified tissue international 23 (1977), S. 215-223 
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    ISSN: 1432-0827
    Keywords: Amorphous mineral ; Bone ; Electron microscopy ; Ultracryotomy ; Ultramicro-incineration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The fine structure of the extracellular phase of avian medullary bone and embryonic chick femur was examined in thin sections prepared by ultracryotomy and ultramicroincineration. Since contact with solutions was completely avoided, little or no loss or dislocation of mineral constituents could occur. Amorphous bone mineral (ABM) was present in two forms: as 15–30 nm spheres and as a structure-free haze. Removal of all organic material by low temperature ashing left the ABM intact. Crystals were usually associated with the ABM. In newly ossifying regions clusters or nodules of randomly oriented crystals and ABM appeared to coalesce when they reached approximately 1 μm in diameter. In highly calcified regions crystals appeared to be oriented along collagen fibers. ABM did not appear to be associated with collagen. Unmineralized collagen was visible in osteoid after staining with dry OsO4 vapor and it appeared to be diverted around nodules. Structures which resembled matrix vesicles were present. Selected area electron diffraction patterns indicated the presence of hydroxyapatite.
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    URL: http://dx.doi.org/10.1007/BF02012788
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    Selective stimulation of net calcium efflux from chick embryo tibiae by parathyroid hormone in vitro (1978)
    Springer
    Calcified tissue international 25 (1978), S. 227-232 
    Details
    ISSN: 1432-0827
    Keywords: Parathyroid hormone ; Bone ; Calcium ; Chick embryo ; Organ culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The purpose of this study was to measure in an in vitro system the movement of Ca and phosphate (Pi) out of bone when treated with parathyroid hormone (PTH). Tibiae from 13-day chick embryos were incubated for up to 8 h in a defined medium containing 1.8 mM Ca. Medium samples were collected every 2 h and were analyzed for Ca, Pi and lactate. Net effluxes from the bones were calculated. When bones were incubated with PTH in the medium (1 U/ml), net Ca efflux was increased 44, 60 and 100% at 4, 6 and 8 h, respectively. At no time was net Pi efflux affected by the hormone. The well known PTH-stimulated lactate production was not seen until 8 h. Lower doses of PTH (0.1 and 0.3 U/ml) were also effective. Comparing PTH (1 U/ml) responsiveness at higher (2.2 mM) and lower (0.9 mM) medium Ca concentrations, showed that with 2.2 mM Ca no increased Ca efflux was seen, while with 0.9 mM Ca significant elevation in medium Ca occurred 2 h sooner than in the experiments using 1.8 mM Ca. In another experiment, varying the medium Pi level from 1 to 2 mM had no effect on the Ca response to PTH. In neither experiment was Pi release affected by PTH. The results of this study have led to the following conclusions: (1) PTH acts on bone to cause an early dose related increase in net Ca efflux; (2) the effect is specific for Ca, since it is not accompanied by an increased Pi efflux, and may be saturated by raising the medium Ca level; and (3) PTH-stimulated Ca efflux in this system is not correlated with, and is probably not a result of increased lactate production.
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    URL: http://dx.doi.org/10.1007/BF02010774
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    A bone resorbing substance from bovine serum albumin (brA) (1978)
    Springer
    Calcified tissue international 25 (1978), S. 233-240 
    Details
    ISSN: 1432-0827
    Keywords: Bone ; Bone resorption ; Albumin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary A fraction (brA), which causes resorption of fetal rat bones in vitro, has been concentrated from bovine serum albumin by anion exchange column chromatography on DEAE Sephadex. This active fraction has also been prepared using DEAE Sephadex A-50 by a batch method with a 0.09M NaCl, 0.1M TRIS buffer, pH 8.35. BrA was 10–30 times more potent than the original albumin. The retained material, which constitutes the bulk of the protein and has less activity than the original albumin, elutes with 0.45M NaCl. Similar treatment of serumα,β or γ globulins does not yield brA. Further enhancement of the bone resorbing activity of brA can be obtained with (NH4)2SO4 fractionation or extraction with CH3OH∶CHCl3. Heating at 55° C for 2 h or at 100° C for 10 min does not affect the activity; overnight incubation with protease destroys the bone resorbing effect. The bone resorbing activity is not removed by dialysis and does not correlate with the protease activity of the fraction. The action of brA is inhibited by 3 mM PO4, 1 μg/ml calcitonin or glucagon, 10−7 M dexamethasone or 0.02 μg/ml actinomycin D. The bone resorbing activity of brA is partially inhibited by 10−7–10−5 M indomethacin. PTH did not elicit bone resorption when added to cultures incubated in chemically defined medium supplemented with 0.1 mg/ml brA. However, brA did not inhibit PTH-induced resorption.
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    URL: http://dx.doi.org/10.1007/BF02010775
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    A new tracer method for the calculation of rates of bone formation and breakdown in osteoporosis and other generalised skeletal disorders (1977)
    Springer
    Calcified tissue international 22 (1977), S. 191-206 
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    ISSN: 1432-0827
    Keywords: Bone ; Calcium ; Strontium ; Apposition ; Tracer analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract 1. Evidence has accumulated that the rate of acceretion (A) of calcium to bone is the sum of two fluxes; apposition involving the laying down of new bone and augmentation which is the result of slow exchange of non-surface bone calcium with plasma calcium pools as the result of solid state diffusion. 2. A method has been devised for separating A into its two components. It requires the use of45Ca or, for clinical studies,85Sr as a calcium tracer. Studies which are initiated with a combined accretion rate-calcium balance study, are concluded with an estimate of the exponent of the power function which has been found to describe the whole body retention of tracer from the second month onward. 3. The impulse response function of the skeleton for the tracer is then calculated, making the assumption that in any uniform volume of bone, osteoclastic resorption is a first order process. Making in addition certain simplifying assumptions, which are shown to have a modest influence on the final results, a mean rate of bone resorption can be calculated using a development of the well known Stewart-Hamilton formula. The apposition rate is calculated as the sum of the resorption rate and the calcium balance. Augmentation and diminution, defined as equal and opposite exchange processes, are given by the difference between A and the apposition rate. 4. The results of our first thirteen studies in normal subjects and patients with metabolic bone disease are presented, together with analyses of some data from the literature. It is concluded that the development of an atraumatic method for measuring rates of bone formation and resorption in the whole body would be an important advance in the study of metabolic bone disease, and this work is presented so that critical comparisons may be initiated between this tracer method and independent histological methods for measuring these parameters.
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    URL: http://dx.doi.org/10.1007/BF02010358
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    Oestrogen binding proteins in bone cell cytosol (1978)
    Springer
    Calcified tissue international 25 (1978), S. 249-254 
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    ISSN: 1432-0827
    Keywords: Bone ; Oestrogens ; Oestrogen receptors ; Binding proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Attempts were made to demonstrate the presence of specific oestrogen binding proteins (“receptors”) in bone cells. High speed cytosol preparations of bone were incubated with several concentrations of radioactive oestradiol alone and with radioactive oestradiol in the presence of a specific antioestrogen, Nafoxidine. Separation of bound and free oestradiol was carried out by dextran coated charcoal treatment and by sucrose gradient ultracentrifugation. Several types of bones likely to be oestrogen-sensitive were investigated: human femoral heads, human phalanx, rat and rabbit calvaria, humeri and femora of female rats. In all experiments we were unable to demonstrate the presence of specific oestrogen receptors in bone cell cytosol indicating that the direct effect of oestrogens on bone, if present, is not mediated by specific oestrogen receptors.
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    URL: http://dx.doi.org/10.1007/BF02010778
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    Initial studies on the crystallinity of the mineral fraction and ash content of isolated human and bovine osteons differing in their degree of calcification (1977)
    Springer
    Calcified tissue international 23 (1977), S. 7-11 
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    ISSN: 1432-0827
    Keywords: Electron spin resonance ; Crystallinity ; Bone ; Osteons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Several groups containing 10–15 isolated osteons differing in their degree of maturity were analysed. Samples were isolated from undecalcified human and bovine bone sections. The crystallinity coefficient, defined as the ratio of the number of radiation-induced paramagnetic defects in the crystalline lattice of hydroxyapatite to the total ash content, was calculated. The results were compared with measurements performed on fragments of total cortical bone, primary periosteal bone, and inner circumferential lamellar bone. The results show a higher crystallinity of fully calcified osteons as compared with that found at the initial stage of calcification. No differences in the ash content were observed between human osteons, from different stages of calcification evaluated morphologically and by X-ray absorption. These differences were evident when bovine osteons differing in their stage of calcification were compared. Human fully calcified osteons contain 60% ash and their crystallinity coefficient is 52.1. Human osteons at the initial stage of calcification contain 57% ash and their crystallinity coefficient is 40.6. The same parameters for fully calcified bovine osteons and for bovine osteons at the initial stage of calcification are 59% ash, 62.6 crystallinity coefficient and 46% ash, 43.0 crystallinity coefficient, respectively.
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    URL: http://dx.doi.org/10.1007/BF02012760
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    Relations between tensile impact properties and microstructure of compact bone (1977)
    Springer
    Calcified tissue international 24 (1977), S. 65-72 
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    ISSN: 1432-0827
    Keywords: Bone ; Strength ; Tension ; Microstructure ; Osteon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Standardized human and beef femoral compact bone specimens were tested in tensile impact and the dynamic mechanical properties were determined. The microstructure of 45 beef and 47 human bone specimens were examined histologically to determine if there is a structural basis to account for strength differences in the bone samples. Strong negative correlations were obtained between the maximum stress and the percentage area of secondary osteons in each specimen. For human bone samples, the energy absorption capacity and the modulus of elasticity were also found to have strong negative correlations with the percentage area of secondary osteons present in each specimen. Linear regression equations were obtained describing the impact strength properties in terms of the percentage areas of secondary osteons and cavities in the samples. Fracture surfaces of the tested bone specimens were examined in a scanning electron microscope. Most surfaces exhibited a fairly rough texture indicating a quasi-cleavage type of failure. Fractographic analysis of bone fracture surface was helpful in understanding the micromechanics of bone fracture.
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    URL: http://dx.doi.org/10.1007/BF02223298
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    Density and composition of trabecular and cortical bone in perinatally irradiated beagles with chronic renal failure (1977)
    Springer
    Calcified tissue international 24 (1977), S. 99-104 
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    ISSN: 1432-0827
    Keywords: Bone ; Density ; Composition ; Renal osteodystrophy ; Dogs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Bone density and composition were studied in trabecular and cortical bone from control 2 and 4 year old beagles and those which had various degrees of renal failure as a result of perinatal irradiation. Changes in the two types of bone were qualitatively similar but consistently greater in trabecular bone. In a group identified as markedly uremic, the decrease (P〈0.025) from control levels in specific gravity was about 4 times greater in trabecular than in cortical samples. The decrease (P〈0.025) in grams of ash/ml was 9% in trabecular bone and 2% in cortical bone. These changes were associated with an increase (P〈0.001) in water content and, on a percent by volume basis, approximately equal decreases in ash (P〈0.025) and combustible matter (P〈0.025). In a mildly uremic group there were similar trends in mean values but the only significant difference was an increase (P〈0.001) in trabecular bone water.
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    URL: http://dx.doi.org/10.1007/BF02223302
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    Effect of salmon calcitonin infusion on plasma concentrations of recently administered45Ca (1977)
    Springer
    Calcified tissue international 24 (1977), S. 201-208 
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    ISSN: 1432-0827
    Keywords: Calcitonin ; Plasma calcium ; Radiocalcium ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The effect of intravenous salmon calcitonin (SCT) infusion on the net rate of loss from plasma of recently injected45Ca has been studied in conscious fasted rats, some of which had been previously thyroparathyroidectomized (TPTX). The45Ca was injected 10 h prior to or 1 or 2 h after the initiation of the infusion. Salmon calcitonin (0.05–0.2 MRC mU/g body weight/h) infusion produced the expected hypocalcemia and hypophosphatemia. The drop in plasma calcium levels produced by the hormone was lowered further by the addition of phosphate to the infusate. Plasma45Ca changes, during SCT infusion, followed a biphasic pattern when the radionuclide injection preceded SCT infusion by 10 h. During the first part of the infusion, the rate of loss of45Ca from plasma was greater in SCT-treated than in control rats. Later, this pattern reversed, and the rate of loss of45Ca from plasma became slower in SCT-treated animals. If45Ca was injected after SCT infusion was initiated only the second phase of the biphasic effect was observed; i.e., disappearance of45Ca from plasma was slower in SCT-infused than in control rats. These data are considered to support the hypothesis that rapid and opposing calcium fluxes exist between bone fluid and plasma, and that calcitonin acts by decreasing the calcium efflux from bone fluid. The calcium moved in this efflux system includes some that has only recently entered bone fluid from plasma. This is the explanation given for the initial decrease in plasma45Ca concentrations following SCT infusion. The reverse effect in the second phase can be explained as the result of a secondary reduction in calcium influx to bone fluid from plasma.
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    URL: http://dx.doi.org/10.1007/BF02223317
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    Correlation of freeze-fracture and scanning electron microscopy of epiphyseal chondrocytes (1978)
    Springer
    Calcified tissue international 26 (1978), S. 237-241 
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    ISSN: 1432-0827
    Keywords: Epiphyseal chondrocytes ; Freezefracture ; Scanning electron microscopy ; Cell processes ; Membrane particles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Chondrocytes in epiphyseal cartilage were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) using freeze-fracture techniques. Freeze-fracture replicas showed large numbers of fingerlike, 0.11–0.15 μm diameter, projections from the chondrocyte surface, with numerous 95–180 Å diameter intramembranous particles associated with both the cell membrane surface and these projections. With SEM, these cytoplasmic projections were also obvious, but appeared collapsed into clusters of globular-shaped projections on the surface of the chondrocytes. With freeze-fracture techniques, in which shrinkage artifacts were essentially eliminated, the cytoplasmic projections were often seen in intimate contact with the extracapsular matrix. However, with chondrocytes prepared by both SEM and conventional TEM, there was evidence of shrinkage, the cytoplasmic projections having little contact with the extracapsular matrix. These findings show that the cytoplasmic processes are not artifacts of tissue processing and provide morphological evidence in support of the hypothesis that matrix vesicles are of cellular origin.
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    URL: http://dx.doi.org/10.1007/BF02013264
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    Scanning electron microscopical study on the fluorosis of enamel in rats (1978)
    Springer
    Calcified tissue international 25 (1978), S. 75-83 
    Details
    ISSN: 1432-0827
    Keywords: Rat ; Fluorosis ; Enamel ; Scanning electron microscopy ; Low temperature incineration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Sixteen 58-day-old male rats of Wistar strain, with a mean body weight of 179 g, were divided into two equal groups. Each group of eight animals was maintained for 70 days on drinking water, ad lib., containing no fluorine (control group) and 100 ppm of fluorine (experimental group). All specimens examined were obtained from the incisal portions of the incisors. The following types of enamel specimens were prepared for scanning electron microscopy: (1) acid-etched specimens; (2) acid-etched specimens followed by low temperature microincineration; and (3) fractured specimens. The enamel formed during high fluoride exposure showed marked hypocalcification, that is, the crystallite density in the prism core and interprismatic region was lower than that of control animals. The organic substances appeared to increase in these regions. These changes were prominent in the outer and middle enamel layers. Such changes following fluoride administration appear to indicate an inhibition of enamel maturation, that is, an inhibition of the mineral deposition and/or an inhibition of organic matrix withdrawal.
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    URL: http://dx.doi.org/10.1007/BF02010754
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    Absorption spectra of bone (1977)
    Springer
    Calcified tissue international 23 (1977), S. 113-114 
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    ISSN: 1432-0827
    Keywords: Bone ; Absorption Spectra ; Collagen ; Hydroxyapatite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Absorption spectra of human bone and its two major constituents (collagen and apatite) were obtained in the wavelength region extending from 2000 to 12,000 Å. In the last two cases a, minimum transmission (maximum absorption) was uniformly observed in the ultraviolet region. The two samples after exposure to ultraviolet radiations show a shift in the peak positions. Absorption peaks in the total bone spectra are not reproducible in its two constituents. After exposure to UV radiations the position of maximum absorption is displaced. A possible interpretation of the observed results is presented.
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    Comparison of effects of parathyroidectomy and ethane-1-hydroxy-1,1-diphosphonate (EHDP) administration upon bone synthesis of hydroxyproline and urinary excretion of hydroxyproline in rats (1977)
    Springer
    Calcified tissue international 23 (1977), S. 115-119 
    Details
    ISSN: 1432-0827
    Keywords: Parathyroidectomy ; Diphosphonates ; Bone ; Collagen ; Hydroxyproline
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Disodium ethane-1-hydroxy-1,1-diphosphonate (EHDP) may impair mineralization and reduce turnover of bone. However, its administration has been shown to lead to an accumulation of osteoid in both man and the rat. Using rats, the effects of surgical parathyroidectomy and administration of EHDP (30 mg EHDP/kg body weight by subcutaneous injection daily for 5 days) upon bone composition, uptake of3H-proline into hydroxyproline in bone and the subsequent urinary excretion of labelled and unlabelled hydroxyproline have been compared. Both parathyroidectomized (PTX) rats and EHDP-treated animals accumulated more hydroxyproline in bone and excreted less total urinary hydroxyproline than sham-PTX control animals, the changes induced by EHDP being of greater magnitude than those induced by surgical parathyroidectomy. Skeletal buildup of hydroxyproline was associated with decreased catabolism of mature collagen rather than enhanced synthesis of hydroxyproline in bone. EHDP administration, although decreasing urinary excretion of newly synthesised hydroxyproline, did not alter the skeletal synthesis of hydroxyproline as measured by uptake of3H-proline. In all parameters measured, responses to EHDP were similar in PTX and sham-PTX rats. It is concluded that depression of parathyroid hormone mediated bone turnover may have contributed to, but did not fully account for, the lowering of bone turnover and changes in bone composition induced by EHDP in sham-PTX rats in the present experiment.
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    Quantitative histology of bone: A computerized method of measuring the total mineral content of bone (1978)
    Springer
    Calcified tissue international 26 (1978), S. 85-89 
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    ISSN: 1432-0827
    Keywords: Bone ; Histology ; Microradiography ; Densitometry ; Computer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary A comparatively simple quantitative method for assessing bone morphology has been evolved. Microradiographs of thin sections of mandible have been scanned with a Joyce-Loebl double beam recording microdensitometer with a scanning autodensidater attachment, using a white beam. For each image the optical densities for all the pixels (picture elements) were divided into 10 groups. The limits of the division were fixed by the maximum and minimum densities occurring within the image. A computer generated map was produced which indicated the spatial distribution of the pixels within each group to which an arbitrarily chosen shading was attached. The number of pixels within each group is also shown on the map. The computer map was compared with the photomicrograph and, where necessary, the original section. The fractional area of hard tissue was then readily determined using the numerical values of each group of pixels.
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    URL: http://dx.doi.org/10.1007/BF02013239
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    Surface area of dental enamel, bone, and hydroxyapatite: Chemisorption from solution (1978)
    Springer
    Calcified tissue international 26 (1978), S. 139-142 
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    ISSN: 1432-0827
    Keywords: Chemisorption ; Surface area ; Hydroxyapatite ; Bone ; Enamel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The surface areas of three different samples of hydroxyapatite, samples of deproteinized bone, and samples of whole and deproteinized enamel were determined by adsorption of an adduct (the diglycidyl ether of bisphenol A with N-phenylglycine) from methylene chloride solution. In all cases, the surface areas of these samples agree well with those obtained by the BET (N2) method.
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    URL: http://dx.doi.org/10.1007/BF02013248
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    Effect of sex steroids on bone collagen synthesis in vitro (1978)
    Springer
    Calcified tissue international 25 (1978), S. 105-110 
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    ISSN: 1432-0827
    Keywords: Progesterone ; 17β estradiol ; Testosterone ; Tissue culture ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Although sex steroids are known to affect skeletal metabolism, their effects on bone collagen synthesis have not been studied. We have examined the direct effects of progesterone, 17β estradiol, testosterone, 5α dihydrotestosterone and dehydroepiandrosterone on bone collagen and noncollagen protein synthesis in cultures of calvaria obtained from 21-day fetal rats. Bones were incubated for 24 to 168 h and3H-proline was added for the last 2 h of culture. Incorporation of the label into collagenase-digestible protein (CDP)1 and noncollagen protein (NCP) was determined using repurified bacterial collagenase. Progesterone caused a dose dependent inhibition of the labeling of CDP at concentrations of 3×10−7 M to 10−5 M after 96 h of culture. A smaller inhibitory effect was observed on NCP. The inhibitory effect was slow in onset and persisted when bones were incubated for 48 h with progesterone and then transferred to control medium for 48 h. Progesterone also inhibited the incorporation of3H-thymidine and3H-uridine into fetal rat calvaria. After 24 h of culture, 17β estradiol and testosterone had no effects on the labeling of CDP and NCP. After 96 h, 17β estradiol had a small and inconsistent stimulatory effect on the labeling of CDP but testosterone had no effect. Neither hormone altered the inhibitory effects of parathyroid hormone, cortisol and progesterone. Dihydrotestosterone and dehydroepiandrosterone had no effects after 24 h and 96 h of culture. 17β estradiol, testosterone and dihydrotestosterone did not affect the incorporation of3H-uridine or3H-thymidine into fetal rat calvaria. Our studies indicate that progesterone is an inhibitor of bone collagen synthesis and estrogens and androgens are not major regulators of bone formation in vitro.
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    URL: http://dx.doi.org/10.1007/BF02010758
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    Plasma proteins present in human cortical bone: Enrichment of theαHS-glycoprotein (1977)
    Springer
    Calcified tissue international 22 (1977), S. 27-33 
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    ISSN: 1432-0827
    Keywords: Protein ; Bone ; Blood plasma ; Dentine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract The spectrum of plasma proteins present in human cortical bone and permanent dentine has been determined. One plasma glycoprotein, theαHS-glycoprotein, was found to be present at a high concentration in both bone and dentine and was shown to be concentrated in the mineralized tissues with respect to the other plasma proteins by factors of between 30 and 100. In this respect theαHS-glycoprotein is analogous to the G2B-glycoprotein and α-glycoprotein of bovine and rabbit b one, respectively. The binding ofαHS-glycoprotein and albumin to calcium phosphates generated within serum samples has been studied at different serum: precipitate ratios. In each case all theαHS-glycoprotein was removed from the samples and theαHS-glycoprotein was concentrated with respect to albumin by factors ranging from 370 at the highest serum: precipitate ratio to 25 at the lowest ratio. The plasmaαHS-glycoprotein concentrations of patients with Paget's disease of bone were shown to be substantially lower than the normal range, with significant negative correlation between theαHS-glycoprotein concentration and the plasma alkaline phosphatase activity.
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    A model-independent comparison of the rates of uptake and short term retention of47Ca and85Sr by the skeleton (1977)
    Springer
    Calcified tissue international 22 (1977), S. 183-189 
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    ISSN: 1432-0827
    Keywords: Calcium ; Strontium ; Bone ; Mathematical modelling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract 1. A method has been devised for comparing the impulse response functions of the skeleton for two or more boneseeking tracers, and for estimating the contribution made by measurement errors to the differences between any pair of impulse response functions. 2. Comparisons were made between the calculated impulse response functions for47Ca and85Sr obtained in simultaneous double tracer studies in sixteen subjects. Collectively the differences between the47Ca and85Sr functions could be accounted for entirely by measurement errors. 3. Because the calculation of an impulse response function requires fewera priori assumptions than other forms of mathematical analysis, and automatically corrects for differences induced by recycling of tracer and non-identical rates of excretory plasma clearance of tracer, it is concluded that differences shown in previous in vivo studies between the fluxes of*Ca and*Sr into bone can be fully accounted for by undetermined oversimplifications in the various mathematical models used to analyse the results of those studies.85Sr is therefore an adequate tracer for bone calcium in most in vivo studies.
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    URL: http://dx.doi.org/10.1007/BF02010357
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    An x-ray diffraction investigation of age-related changes in the crystal structure of bone apatite (1977)
    Springer
    Calcified tissue international 22 (1977), S. 219-226 
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    ISSN: 1432-0827
    Keywords: Hydroxyapatite ; Bone ; X-ray Diffraction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Evidence relating to the existence of crystalline bone mineral in vivo is considered, and bone apatite crystal structure investigated using an x-ray powder diffraction technique. Specimens of femoral compacta excised post-mortem from male and female subjects ranging from 3 1/2 years to 87 years of age have been studied. Values of the ratio c/a of bone apatite crystal cell axes for females are significantly higher (p〈0.05) than for males. Moreover, significant change of c/a with age is observed for males (p=0.0005) but not for females (p=0.30). Differences in c/a are interpreted as indicating substitution of constituent ions in the bone apatite crystals.
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    URL: http://dx.doi.org/10.1007/BF02010360
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    Ethane-1-hydroxy-1,1-diphosphonate (EHDP) effects on incorporation and accumulation of osteoclast nuclei (1977)
    Springer
    Calcified tissue international 22 (1977), S. 243-252 
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    ISSN: 1432-0827
    Keywords: Diphosphonate ; Bone ; Osteoclasts ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Male rats weighing 100 g were injected with vehicle (control group), 0.4 or 4.0 mg/kg/day of ethane-1-hydroxy-1,1-diphosphonate (EHDP). Beginning after 6 days of EHDP treatment all rats received six subcutaneous injections of3H-thymidine at 8 h intervals. The multiple labeling index of autoradiographically defined labeled cells was determined for the osteoprogenitor cells of the primary spongiosa of the proximal tibial metaphysis. The osteoclasts in the proximal tibial metaphysis were assayed for population parameters and incorporation of labeled nuclei at sequential intervals after the administration of3H-thymidine. After 6 days of EHDP pre-treatment the multiple labeling index of the osteoprogenitor cells was reduced with 4.0 mg/kg/day dose of EHDP. At the beginning of the experimental kinetic sampling period, after the 6 days of EHDP pre-treatment, EHDP treatment resulted in significant increases in the numbers of osteoclasts, nuclei per osteoclast profile, and total osteoclast nuclei. During the sampling period, the 4.0 mg/kg/day dose of EHDP caused further increases in the number of total osteoclasts. EHDP treatment caused a marked increase in the rate of incorporation and accumulation of3H-thymidine-labeled nuclei in osteoclasts. Thus, EHDP causes an accelerated rate of osteoclast production from precursor cells in spite of its ability to slow bone resorption. Although the origin of osteoclast nuclei is not clear, the kinetic data from this study suggests that osteoclast nuclei are not arising from osteoprogenitor cells or osteocytes in the EHDP-treated animals.
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    URL: http://dx.doi.org/10.1007/BF02010363
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    Movement of125I albumin and125I polyvinylpyrrolidone through bone tissue fluid (1977)
    Springer
    Calcified tissue international 23 (1977), S. 103-112 
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    ISSN: 1432-0827
    Keywords: Albumin ; Polyvinylpyrrolidone ; Tissue fluid ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The passage of tissue fluid through cortical bone has been investigated using radioactively labelled macromolecules as markers. The results suggest that in the cortex of young rabbit femur the movement of tissue fluid is in the same net direction as blood, mainly from the endosteal to the periosteal surface. Some albumin is incorporated from extravascular tissue fluid into calcified matrix at sites of bone formation. Polyvinylpyrrolidone, average molecular weight 35,000 is able to pass through extravascular tissue fluid in bone but isnot incorporated into calcified matrix. In rabbits made vitamin D deficient, much less albumin is retained in regions of bone formation than is the case with controls. Albumin adsorbs to the surface of calcium phosphate precipitates and it is suggested that this mechanism may be mainly responsible for its incorporation into bone.
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    URL: http://dx.doi.org/10.1007/BF02012773
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    Ultrahistochemical analysis of glycosaminoglycan hydrolysis in the rat periodontal ligament (1977)
    Springer
    Calcified tissue international 24 (1977), S. 143-149 
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    ISSN: 1432-0827
    Keywords: Bone ; Periodontal ligament ; Bone resorption ; Aryl sulfatase ; Mineralization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The distribution of aryl sulfatase in the rat periodontal ligament was investigated by ultrastructural histochemistry. In the periodontal ligament aryl sulfatase was localized specifically in osteoclasts and in vicinal perivascular macrophages. Macrophages associated with bone formation did not stain. The authors interpret this specificity as a potential marker for osteoclast differentiation from macrophages — or as a further indication of the capacity of macrophages to modulate their enzymatic complement in response to the environment. To explain the absence of aryl sulfatase in areas of bone formation we suggest that different sulfate esters are mobilized from resorbing and mineralizing matrices, and that only the enzyme associated with bone resorption is histochemically detectable with the artificial substrates currently used.
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    URL: http://dx.doi.org/10.1007/BF02223308
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    An X-ray study of the paracrystalline nature of bone apatite (1977)
    Springer
    Calcified tissue international 24 (1977), S. 243-248 
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    ISSN: 1432-0827
    Keywords: Paracrystallinity ; Hydroxyapatite ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary X-ray diffraction patterns from oriented bone sections show that the crystalline apatite content of untreated mature cortical bovine bone has, in fact, a paracrystalline structure (i.e., no long range order). There is anisotropy in both lattice distortions and the sizes of the coherently diffracting domains. The paracrystalline mean distance fluctuations, (g) were found to be 1.5 (±0.1)% and 2.9 (±0.2)% for the basal and prism planes respectively, the corresponding paracrystalline sizes being 220 (±20) and 70 (±10) Å. The paracrystalline structure became more ordered above 600°C, suggesting the association of hydroxyl and possibly carbonate and other ions with the paracrystalline structure. The paracrystalline model for bone apatite helps explain anomalies between X-ray and electron microscope measurements of crystal size and also some of the biological functions of the crystalline apatite.
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    URL: http://dx.doi.org/10.1007/BF02223323
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    The effect of growth retardation and of osteomalacia on the uptake of albumin by bone (1978)
    Springer
    Calcified tissue international 25 (1978), S. 29-35 
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    ISSN: 1432-0827
    Keywords: Albumin ; Bone ; Growth retardation ; Osteomalacia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary 125I-labeled rat albumin injected intravenously into rats was taken up by growing bone. Some of this radioactive albumin could be removed from bone by washing with saline, the proportion so removed decreasing from 82.5% at 1 day to 7.4% at 8 days. Both the total radioactivity, and that remaining in bone after saline wash, were reduced when growth was slowed by alteration or restriction of the diet. Although the amount of125I albumin in rachitic bone was reduced, autoradiography showed that radioactivity was present in rachitic osteoid. Immunoprecipitation using anti-rat-albumin serum showed that about half of the radioactivity released from normal bone by EDTA was still attached to albumin. These results suggest that albumin plays some part in the growth of bone.
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    URL: http://dx.doi.org/10.1007/BF02010748
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    Localization of α-galactomannan on the surface of Schizosaccharomyces pombe cells by scanning electron microscopy (1977)
    Springer
    Archives of microbiology 112 (1977), S. 123-126 
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    ISSN: 1432-072X
    Keywords: Bandeiraea simplicifolia ; Schizosaccharomyces pombe ; Colloidal gold ; Cytochemistry ; α-Galactomannan-lectin ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Galactomannan was localized by scanning and transmission electron microscopy on the cells and cell walls of Schizosaccharomyces pombe. The markers were prepared from colloidal gold granules labelled with an α-galactopyranosyl-binding lectin isolated from the seeds of Bandeiraea simplicifolia. Part or all of this α-galactomannan was present in the outer layer of the cell wall and was uniformly distributed even on the fission scars.
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    URL: http://dx.doi.org/10.1007/BF00429323
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    Localization of mannan at the surface of yeast protoplasts by scanning electron microscopy (1976)
    Springer
    Archives of microbiology 109 (1976), S. 9-14 
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    ISSN: 1432-072X
    Keywords: Candida utilis ; Saccharomyces cerevisiae ; Colloidal gold ; Cytochemistry ; Mannan ; Plasma membranes ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The β(1→3)glucanase of Basidiomycete QM 806 was used to prepare Saccharomyces cerevisiae and Candida utilis protoplasts. Plasma membranes isolated from S. cerevisiae contained a small amount of mannose and traces of glucose and ribose. Randomly distributed α-mannan was detected by scanning electron microscopy at the surface of prefixed protoplasts using colloidal gold labelled with Concanavalin A as a marker. C. utilis protoplasts were also marked with anti-mannan antibodies. Again the distribution of mannan was random. This experiment indicated also that plasma membrane mannan has the same immunochemical determinants as cell wall mannan. It is hypothesized that mannan is mainly located in the outer layer of plasma membranes.
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    Mating in Chlamydomonas eugametos (1976)
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    Archives of microbiology 109 (1976), S. 31-35 
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    ISSN: 1432-072X
    Keywords: Scanning electron microscopy ; Chlamydomonas ; Cell agglutination ; Cell fusion ; Flagella
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A technique has been developed by which mating gametes of Chlamydomonas eugametos can be studied in the Scanning Electron Microscope. A detailed description of the mating process, from the initial flagellar agglutination until the release of free vis-à-vis pairs, is presented. Flagella appear to agglutinate at random points on their surface. This is followed by a rapid increase of the contact area such that they “line-up” tip to tip. Flagella always exhibit a typical position prior to cell fusion. After cell fusion the flagella of a pair separate rapidly while the female have shortened about 33%. In a vis-à-vis pair the plasma bridge has contracted. The observations are interpreted in terms of a specific reorganization of the sexuale aggregate.
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    Scanning electron microscopic studies on the development of the chick retina (1976)
    Springer
    Cell & tissue research 170 (1976), S. 145-159 
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    ISSN: 1432-0878
    Keywords: Neurogenesis ; Retina ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Fixed retinae of chick embryos and chicks of the first week after hatching were fractured and examined with the scanning electron microscope. The matrix cells of the retina proliferate up to the beginning of the second week. The migrating cells are oriented in cell cords. This columnar organization prevails up to the development of the plexiform layers formed as a consequence of the outgrowth of the dendritic and axonal cell processes. Special attention was paid to the differentiation of the ganglion, bipolar and receptor cells, and the radial fibers (Müller cells). Two main morphological patterns are significant for the organization of the retina during neurogenesis: a) the cell to cell contacts of migrating cells and b) the spatial arrangement of Müller cells which could provide guidelines for migration of neuronal elements.
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    URL: http://dx.doi.org/10.1007/BF00224296
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    A combined scanning and transmission electron microscopic study and electron probe microanalysis of human pineal acervuli (1976)
    Springer
    Cell & tissue research 174 (1976), S. 129-137 
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    ISSN: 1432-0878
    Keywords: Pineal organ, human ; Acervuli ; Scanning electron microscopy ; Transmission electron microscopy ; Electron probe microanalysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Untreated, decalcified and trypsinized acervuli from human pineal bodies were studied with the scanning and transmission electron microscope as well as by electron probe microanalysis. The mulberry-like acervuli are composed of a various number of spherical lobes (135–800 μm) between which clustered groups of globuli (4–14 urn in diameter) are observed. The acervular lobes are very probably formed by an aggregation of these globuli. Small round particles 125–500 Å in diameter are observed on the surface of the pineal concretions. These are not influenced by either decalcification or trypsin treatment. The acervular mineral corresponds morphologically to hydroxyapatite. The electron probe microanalysis reveals the existence of calcium and phosphorus as main components of the acervuli. Small quantities of magnesium and strontium were also detected.
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    URL: http://dx.doi.org/10.1007/BF00222155
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    Scanning electron microscopy of dissociated pancreatic acinar cell surfaces (1977)
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    Cell & tissue research 176 (1977), S. 493-504 
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    ISSN: 1432-0878
    Keywords: Pancreas ; Acinar cells ; Cell surface ; Dissociation ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pancreatic acinar cell surfaces have been studied by SEM with a dissection technique and correlated with results obtained by TEM. The SEM results demonstrate characteristic arrangement of microplicae which in some areas are densely packed. In many areas, the microplicae are distributed in such a manner that they create zones with typical geometrical shapes and show a relatively smooth surface. These smooth areas may coincide, as indicated by correlated TEM results, with the limits of intimate contact between adjacent acinar cells which, in turn, represent part of the junctional complex. Another aspect revealed by these SEM preparations concerns the presence of groups of densely packed microplicae, arranged in regular rows and distributed along some grooves and/or infoldings of the cellular surface. On the basis of SEM and TEM information, it is likely that these structures correspond to intercellular (and possibly, in some cases, intracellular) canaliculi which topographically form a kind of extensive microlabyrinthine arrangement running along all the cell sides. One final point revealed by fractured samples concerns the finding of spherical zymogen droplets within the vesicles of the Golgi complex. Because in many scanning images these vesicles appear connected by small openings, it is suggested that they may represent a system of intercommunicating chambers (vacuoles) through which the zymogen droplets can be continuously accumulated and discharged into the acinar lumen.
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    The third ventricle of monkeys (1977)
    Springer
    Cell & tissue research 177 (1977), S. 307-316 
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    ISSN: 1432-0878
    Keywords: Third ventricle ; Mature monkeys ; Scanning electron microscopy ; Ependyma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Surface features of the ependymal lining of the third ventricle in mature male and female monkeys have been investigated with scanning electron microscopy (SEM). Broad aspects of third ventricular morphology from three species of monkey are similar regardless of sex. The lateral walls are heavily ciliated whereas the ventral floor and most ventral parts of the lateral walls are not. Clumps of cilia on the lateral walls are so dense that underlying surface details are usually obscured. There is a transition zone between the ciliated lateral wall and nonciliated ventral floor. The floor and lower part of the lateral walls of the third ventricle exhibit a characteristic polygonal pattern upon which surface specializations such as microvilli, blebs and polymorphous membrane protrusions are superimposed. Ependyma of the choroid plexus of the third ventricle also display membrane specializations. Supraependymal cells are more visible in nonciliated regions.
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    Morphology, morphometry and electron microscopy of HeLa cells infected with bovine Mycoplasma (1976)
    Springer
    Cell & tissue research 170 (1976), S. 1-16 
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    ISSN: 1432-0878
    Keywords: Tissue culture cells ; Mycoplasma ; Light microscopy ; Transmission electron microscopy ; Scanning electron microscopy ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The host-parasite relationship of HeLa M cells artificially infected with a bovine species of Mycoplasma was studied by light microscopy, transmission electron microscopy and scanning electron microscopy. The use of morphometry to quantitate some of the findings was explored. The parasites were seen in locations extracellular to the cell surface. The detection of small numbers of organisms by light microscopy was well demonstrated by use of the fluorescent antibody technique. Scanning electron microscopy proved to be an excellent method for revealing the surface details of cell-parasite morphology. Ultra-thin sections showed that the parasites are aligned mostly parallel to the plasma membrane of the host cell but separated by a gap of 10 nm. Morphometry indicated an average of 69 organisms per cell surface occupying 1.7% of the surface area. An increase of 26% in diameter of the HeLa cells, possibly as a result of infection, was observed.
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    A scanning electron microscope study of the development of free axonal sprouts at the cut ends of dorsal spinal nerve roots in the rat (1976)
    Springer
    Cell & tissue research 170 (1976), S. 507-513 
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    ISSN: 1432-0878
    Keywords: Axons ; Scanning electron microscopy ; Neurones, afferent ; Nerve regeneration ; Spinal nerve roots
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Rat dorsal spinal nerve roots were cut and the tip on the ganglionic side of the cut was examined by scanning electron microscopy at 0, 7, 20 and 48 h after operation. Seven hours after cutting, free axonal sprouts had started to protrude from the cut end of the nerve. After 20 h the free sprouts were more profuse than at 7 h but were smaller and had a rougher surface. At both 7 and 20 h many of the sprouts consisted of a stalk 2–7 μm in diameter with a bulbous end 5–20 μm in diameter. A few branching sprouts were seen. At 48 h the sprouts were shrunken with a deeply furrowed surface. The significance of the surface structure of the sprouts is discussed.
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    URL: http://dx.doi.org/10.1007/BF00361708
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    Effects of castration and androgen-substitution on the morphology of the epididymal epithelium of the Japanese monkey, Macacus fuscatus, as revealed by scanning electron microscopy (1976)
    Springer
    Cell & tissue research 170 (1976), S. 515-521 
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    ISSN: 1432-0878
    Keywords: Epididymal epithelium ; Castration ; Androgen-substitution ; Japanese monkey ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The caput epididymidis from castrated and androgen-supplemented, castrated Japanese monkeys was observed with the scanning electron microscope. The experimental findings were compared with the normal structures in control animals. The epididymal lumen of control animals was lined by a tall, pseudostratified columnar epithelium possessing long, slender stereocilia which were densely arranged in a tuft-like form. After castration, the epididymal epithelium was decreased in height to one-fifth of controls. The stereocilia were also considerably reduced in length and in number, resulting in a flattened epithelial surface with polygonal boundaries. Frequent projection of a long, single cilium from an epithelial cell into the lumen was also a prominent feature in the epididymal ducts of the castrated animals. Administration of testosterone to the castrated animals resulted in almost complete recovery of the epididymal epithelium as well as regeneration of the stereocilia which regained a tuft-like arrangement.
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    The aesthetes of chitons (1976)
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    Cell & tissue research 172 (1976), S. 379-388 
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    ISSN: 1432-0878
    Keywords: Chitons ; Receptors ; Shell surface ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The shells of the chitons Lepidochitona cinereus, Sypharochiton pelliserpentis, Amaurochiton glaucus and Onithochiton neglectus were examined by scanning electron microscopy. In all species the surface terminations of the megalaesthete and micraesthete organs could be identified lying flush with the shell surface, as well as, lenses of the shell eyes in O. neglectus. Periostracal debris and encrusting diatoms were a usual feature of the shell surfaces. The micraesthete subsidiary caps normally appear featureless, but the megalaesthete apical caps sometimes appear to be perforated. The reasons for this perforate appearance are discussed and it is concluded that it provides no evidence for the normal passage of substances out of or into the megalaesthete.
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    URL: http://dx.doi.org/10.1007/BF00399520
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    Scanning electron microscopy of bone cells in culture (1976)
    Springer
    Cell & tissue research 166 (1976), S. 65-70 
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    ISSN: 1432-0878
    Keywords: Collagen ; Bone ; Cell culture ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Embryonic and young rat bone cells have been grown in culture and examined in the scanning electron microscope (SEM). Compared with cells fixed in situ and taken directly from the animal, the cultured osteoblastic cells were smoother, flatter and more extensive and showed tighter intercellular contacts. Some matrix is formed in culture and undergoes at least partial mineralization as judged by the accumulation of Ca and P measured by energy dispersive x-ray analysis. Findings concerning the morphology of the collagen arrangement were indecisive. Some superficial cells, free of surrounding matrix, resembled osteocytes in normal in vivo bone. This may indicate that a proportion of the extracellular matrix produced by the cultured cells failed to polymerise into recognizable bone matrix, and that osteocytic morphology is not dependent upon the physical characteristics of the bone matrix.
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    URL: http://dx.doi.org/10.1007/BF00215125
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    Effect of calcium depletion and subsequent repletion on parathyroids, parafollicular (C) cells and bone in the growing pig (1976)
    Springer
    Cell & tissue research 168 (1976), S. 373-384 
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    ISSN: 1432-0878
    Keywords: Calcium ; Bone ; Parathyroid ; Parafollicular cells ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the chief cells of the parathyroid gland and thyroid parafollicular (C) cells and the morphology of bone in calcium depletion and subsequent repletion were examined in young growing pigs. A low calcium diet resulted in osteopenia, increased removal of the cartilaginous core, osteoclasia and osteocytic osteolysis. Subsequent repletion quickly returned bone to normal. In pigs fed the low calcium diet, there was a marked depletion of secretory granules but a striking increase in the number of microtubules in chief cells. Increasing the calcium content of the diet to normal quickly returned the ultrastructural appearance of chief cells to apparent normal. In the initial response to calcium repletion, chief cells exhibited large number of lysosomes and occasionally prominent paracrystalloid bodies. Electron microscopic examination of parafollicular (C) cells of the thyroid gland failed to reveal differences in ultrastructure between test and control pigs. These findings support the view that bone resorption following calcium deficiency may be the result of a secondary hyperparathyroidism rather than of calcium deficiency per se.
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    URL: http://dx.doi.org/10.1007/BF00215314
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    Interaction of rabbit sperm and egg (1976)
    Springer
    Cell & tissue research 169 (1976), S. 277-287 
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    ISSN: 1432-0878
    Keywords: Rabbit gametes ; Cryofractography ; Scanning electron microscopy ; Transmission electron microscopy ; Zona pellucida
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Rabbit ova fertilized in vitro were prepared for scanning electron microscopy by ethanol-cryofracturing and critical-point drying methods and were also embedded and sectioned for transmission electron microscopy. Study of a region of interaction between sperm and zona pellucida with scanning electron microscopy reveals the latter to be composed of a complex network of fibers interspersed with numerous pores. Transmission electron microscopy of the same region reveals a “typical” homogeneous composition of the zona pellucida. Ultrastructural observations of thin sections passing through the region of sperm-egg interactions or through other regions of the ovum or its investments reveals very little methodological distortion of the various intracellular organelles or matrix. Application of the procedures described provides not only an elucidation of surface detail but also reveals intracellular cytoplasmic information about the same specimen during in vitro fertilization.
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    URL: http://dx.doi.org/10.1007/BF00219601
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    Experimental study of changes in osteoblastic shape induced by calcitonin and parathyroid extract in an organ culture system (1976)
    Springer
    Cell & tissue research 169 (1976), S. 449-465 
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    ISSN: 1432-0878
    Keywords: Bone ; Osteoblasts ; Cell surface ; Cell shape ; Calcitonin ; Parathyroid extract ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neonate rat endocranial osteoblasts were cultured on their bone surfaces in control medium (CC) or medium to which either parathyroid extract (PTE) or calcitonin (CT) had been added for 2, 4, 8 or 24 h. Some were cultured for 24 h in CC, then for 2, 4, 8 or 24 h in either CT or PTE medium; or for 24 h in PTE, then for 2, 4, 8 or 24 h in either CC or CT; or 24 h in CT and 2, 4, 8 or 24 h in CC. The dorsal ruffling of the cells in CC was found to be suppressed by later culturing with PTE and the disoriented cells reorganized to form arrays of parallel cells. The effects of PTE were also reversed by CC or CT: the osteoblasts in the second culture (CC) lost elongation and order, and proceeded through a proliferative phase before exhibiting the ruffling form similar to a single CC 24 h culture. PTE-cultured osteoblasts showed an increase in cell overlap and contact so that a more competent barrier was formed separating the bone from the medium. In control or CT medium, however, intercellular gaps were greater than in vivo.
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    URL: http://dx.doi.org/10.1007/BF00218146
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    A critical reevaluation of the structure of the rat uriniferous tubule as revealed by scanning electron microscopy (1976)
    Springer
    Cell & tissue research 166 (1976), S. 91-100 
    Details
    ISSN: 1432-0878
    Keywords: Kidney (rat) ; Uriniferous tubule ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of luminal surface of clearly identified portions of uriniferous tubules has been studied by scanning electron microscopy to elucidate some controversies concerning the topography of certain surface formations. The results show a characteristic pattern of the luminal surface in the region of Henle's loop, which was assumed by previous authors, to belong to the collecting tubule. Furthermore it is demonstrated that no cilia are present within the terminal portion of the collecting tubules.
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    URL: http://dx.doi.org/10.1007/BF00215128
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    Aggregation-induced alterations in fibroblast morphology (1976)
    Springer
    Cell & tissue research 174 (1976), S. 499-518 
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    ISSN: 1432-0878
    Keywords: Fibroblast ; Human ; Transmission electron microscopy ; Scanning electron microscopy ; Aggregation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The different stages during aggregation of diploid human skin fibroblasts have been examined by transmission and scanning electron microscopy. As a result of aggregation, fibroblasts form a complex tissue configuration. Numerous intercellular junctions can be observed, while the cells remain polygonal and do not develop an organised intracellular cytoskeleton. Cell division occurs only rarely. After aggregation, signs of progressive auto-digestion develop. Adhesion to a substrate results in outgrowth of the cells and monolayer formation, even when extensive cell damage had occurred. The morphology of fibroblasts in aggregates and in the monolayers, from which they were derived, is compared and the contribution of the aggregate system to the study of fibroblast behavior is discussed.
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    URL: http://dx.doi.org/10.1007/BF00232835
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    Scanning electron microscopy of the glomerular filtration membrane in the rat kidney (1976)
    Springer
    Cell & tissue research 166 (1976), S. 299-314 
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    ISSN: 1432-0878
    Keywords: Renal glomerulus (Rat) ; Endothelial cells ; Blood capillaries ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The rat kidney was perfused with saline and glutaraldehyde, treated with Murakami's tannin-osmium impregnation method, ethanol-freeze cracked and dried by the critical point method. Gold-palladium evaporated specimens were observed in a field-emission scanning electron microscope. The glomerular filtration membrane, fractured in different planes was observed with the following results: 1. Adjacent pedicles originate from different podocytes. No interpedicular bridges of apparent cytoplasmic nature could be found. 2. The basement membrane, in grazing fractures shows a horizontally layered architecture. 3. The attenuated endothelial sheet (lamina fenestrata) is divided into compartments, which we suggest should be called “areolae fenestratae”, by cytoplasmic crests radiating from the nucleated portion of the endothelial cell. A crest also occurs along the cell margin, which contacts a similar crest at the margin of the adjacent cell. 4. The pores in the areolae fenestratae are variable in size (30−150 nm diameter). A knob-like projection from the apparently naked basement membrane is found in a portion of the pores. 5. Numerous microvilli may occur on the endothelium. Some of them anastomose and fuse with one another to form a net whose meshes appear identical with the endothelial pores. Domes and shelves formed of a fenestrated cytoplasmic sheet also occur above the ordinary level of the endothelial lining. A hypothesis implicating microvilli in partial renewal of the endothelial sheet is proposed. This study was assisted by Mr. K. Adachi of the SEM Laboratory at the Niigata University School of Medicine.
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    URL: http://dx.doi.org/10.1007/BF00220127
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    Three-dimensional development of luminal projections and junctional complexes in the developing central nervous system blood vessels of the rat (1977)
    Springer
    Cell & tissue research 175 (1977), S. 541-549 
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    ISSN: 1432-0878
    Keywords: Blood vessels ; High voltage electron microscopy ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The luminal surface features and Junctional complexes from developing blood vessels in the rat central nervous system have been studied by high-voltage electron microscopy and scanning electron microscopy. Developing blood vessels exhibit three types of luminal projections; marginal folds or ridges at Junctional complexes, ridges not at Junctional complexes and microvilli. Both types of ridges are associated with troughs or depressions in the luminal surface of the endothelial cell. Those ridges not associated with Junctional complexes take part in the production of enclosed tunnels in the endothelial cell cytoplasm. Fusion of the external leaflets of Junctional complexes between adjacent endothelial cells occurred, initially, near the luminal surface of the blood vessel with other small fusion sites forming in the direction of the basal lamina secondarily. Further fusion activity to produce the zonula occludens type junction appeared to spread outwards from the smaller fusion sites.
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    URL: http://dx.doi.org/10.1007/BF00222417
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    Photoreceptor-like outer segments in the pineal organ of the lovebird, Uroloncha domestica (Aves: Passeriformes) (1977)
    Springer
    Cell & tissue research 182 (1977), S. 139-143 
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    ISSN: 1432-0878
    Keywords: Pineal organ ; Uroloncha domestica (Aves, Passeriformes) ; Photoreceptor-like cells ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the pineal organ of the lovebird, Uroloncha domestica, bulbous, cup-shaped and elongated outer segments of photoreceptor-like pinealocytes are demonstrated by scanning electron microscopy. These scarce outer segments, 4–11 μm in length, extend into the pineal lumen. The present structural observations speak in favor of photosensitive pinealocytes in the pineal organ of Uroloncha domestica. The relation of the photoreceptor-like pinealocytes to acetylcholinesterase-positive nerve cells and a nervous connection between the pineal and the brain indicate that the pineal organ of this passeriform species may be the site of neuroendocrine and photoreceptive functions.
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    URL: http://dx.doi.org/10.1007/BF00222062
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    Surface morphology of lens fibers from eyes of normal and microphthalmic (Browman) rats (1976)
    Springer
    Cell & tissue research 167 (1976), S. 425-438 
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    ISSN: 1432-0878
    Keywords: Scanning electron microscopy ; Crystalline lens ; Microphthalmos
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The surface features of cortical fibers from lenses of normal adult rats and microphthalmic rats of the Browman strain have been studied by scanning electron microscopy. In the normal lenses, superficial cortical fibers follow a straight course from inner to outer pole whereas the deeper cortical fibers, while straight near the poles, pursue an undulating or zig-zag course at and near the equator. Almost all of the fibers are hexagonal in cross section and all fibers throughout their entire length are bound by interdigitating processes at each corner of the hexagon to corners of two adjacent fibers. Some fibers are also affixed by a single row of ball and socket junctions located on their broad outer and inner surfaces. Lens fibers from Browman rats display both minor and major abnormalities. These included segmentation, formation of incisures and lateral protrusions, corrugation and villous-like alteration of the broad fiber surface and development of parallel ridges on broad surfaces in a basket-weave pattern.
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    URL: http://dx.doi.org/10.1007/BF00215175
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    Scanning electron microscopy of photoreceptor cells in the light- and dark-adapted retina of Haplochromis burtoni (Cichlidae, Teleostei) (1976)
    Springer
    Cell & tissue research 175 (1976), S. 123-130 
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    ISSN: 1432-0878
    Keywords: Retina ; Haplochromis burtoni ; Photoreceptor cells ; Light-adaption, dark-adaption ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The photoreceptor layer in the retina of Haplochromis burtoni (Cichlidae, Teleostei) was studied by scanning electron microscopy. Three types of receptors were identified: rods, single-cones and double-cones. The three-dimensional arrangement of these photoreceptors is described in the light- and dark-adapted retina. The surface of the inner segment of the photoreceptor cells displays fine vertical fissures which give rise to slender processes. These so called calycal processes which are of different lengths in rods and cones, surround the beginning of the smooth-surfaced outer segment. The myoid, the contractile part of the receptor, which is located beneath the ellipsoid, was examined in the single-cones of the dark-adapted retina. It is a slender structure with surface infoldings. The myoid, studied by transmission electron microscopy, contains bundles of parallel myofilaments, which are thought to be contractile.
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    URL: http://dx.doi.org/10.1007/BF00220828
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    The salivary glands of the cockroach Nauphoeta cinerea (Olivier) (1978)
    Springer
    Cell & tissue research 187 (1978), S. 525-534 
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    ISSN: 1432-0878
    Keywords: Salivary glands ; Insects ; Innervation ; Light microscopy ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The innervation of the salivary gland of the cockroach Nauphoeta cinerea (Olivier) has been investigated with the use of light and scanning electron microscopy. Light microscopy of methylene blue stained glands reveals the presence of a dual innervation arising from the ventral nerve cord and the stomodeal nervous system; the principal innervation is that from the ventral nerve cord which passes to the gland via the reservoir ducts. Branches of these nerves form a plexus on the acinar surface, the axons of which exhibit swelling at irregular intervals. The presence of this surface plexus and the axonal swellings was confirmed by scanning electron microscopy both in normal glands and in those in which the basal lamina had been removed by means of an HCl-collagenase digestion method. No acinar plexus was seen to be formed by branches of the stomatogastric nerve that were associated with the gland. However, other branches of this nerve were clearly connected with a complex network of multipolar neurones on the surfaces of the anterior regions of both salivary reservoirs.
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    URL: http://dx.doi.org/10.1007/BF00229617
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    The human rete testis (1978)
    Springer
    Cell & tissue research 189 (1978), S. 409-433 
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    ISSN: 1432-0878
    Keywords: Rete testis ; Human ; Histophysiology ; Chordae retis ; Scanning electron microscopy ; Transmission electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The human rete testis was examined with regard to 1) the number and distribution of entrances of seminiferous tubules, 2) the light microscopic topography and 3) details of the passages as revealed by scanning and transmission electron microscopy. In a newborn 1474 entrances were counted, approximately 50 % entering from the right and 50 % from the left of the central long axis. Three major subdivisions of the rete were distinguished and described: a septal (or interlobular) part represented by tubuli recti, a tunical (or mediastinal) part which is a true network of channels, and an extratesticular part characterized by dilatations (up to 3 mm wide) which we have called bullae retis. In SEM, cylindrical strands running from wall to wall in the tunical and extratesticular rete spaces are a prominent feature. We have called these chordae retis. They are covered by epithelium and are 5–40 μm wide and 15 to more than 100 μm long. They contain a peculiar tissue consisting of central myoid cells in a fibroelastic matrix. The smaller chordae are avascular. In the light of these findings the rete is interpreted as a highly complex myoelastic sponge. Its function is discussed.
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    URL: http://dx.doi.org/10.1007/BF00209130
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    Model of skin vascularization in Rana esculenta L.: Scanning electron microscopy of microcorrosion casts (1978)
    Springer
    Cell & tissue research 191 (1978), S. 539-548 
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    ISSN: 1432-0878
    Keywords: Frog skin ; Respiratory capillaries ; Capillary networks ; Microcorrosion casts ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Microcorrosion casts of blood vessels in the skin of Rana esculenta L. were examined by means of scanning electron microscopy with particular reference to the subepidermal network of respiratory capillaries. Due to the fact that arteries and veins lie in the deeper layers of the stratum spongiosum of the corium, the respiratory vessels form a morphologically homogeneous network. Functionally, however, this network is subdivided into small areas with a centripetal direction of blood flow. The deep capillary net, situated at the base of the stratum compactum of the corium, is not so dense as the respiratory network and does not directly communicate with it. Alveolar glands of the skin have no effect on the distribution of capillaries in the two networks.
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    URL: http://dx.doi.org/10.1007/BF00219816
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    Scanning electron microscopy of the renal corpuscle of the mesonephros in the lamprey, entosphenus japonicus martens (1978)
    Springer
    Cell & tissue research 187 (1978), S. 105-113 
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    ISSN: 1432-0878
    Keywords: Mesonephros ; Lamprey ; Renal corpuscle ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The renal corpuscle of the lamprey mesonephros was studied under the scanning electron microscope. Bowman's capsules with individual spaces are chockshaped sacs closely packed together along a medial artery. The lateral walls of the capsules are apposed to those of neighbouring capsules. Glomerular capillaries from the medial artery extend radially between the apposed walls of neighbouring Bowman's capsules. Bulgings of capillaries into the capsular space are associated with mesangial folds of the capsular epithelium. The transitional zone of the visceral layer with podocytes and the parietal layer of squamous epithelium is bounded by linearly arranged rod-shaped epithelial cells. Apertures of the urinary tubule are lined by cells equipped with a fascicle of cilia.
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    URL: http://dx.doi.org/10.1007/BF00220622
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    Cytochalasin B and water transport (1978)
    Springer
    Cell & tissue research 188 (1978), S. 375-388 
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    ISSN: 1432-0878
    Keywords: Urinary bladder ; Skin ; Toad, frog ; Water flow ; Na transport ; Vasopressin ; Cytochalasin B ; Microfilaments ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A morpho-functional study of the effects of cytochalasin B (CB) on Na and water transport was made in amphibian epithelia. The functional studies confirmed the dissociation of the natriferic and hydrosmotic effects of vasopressin in toad urinary bladders exposed to CB and showed in addition that the block of the hydrosmotic effect was reversible and could still be induced in epithelia maximally stimulated with the hormone. Scanning electron microscopy revealed that CB, per se, did not alter the apical surface of the bladders. An almost total loss of microvilli of granular cells was seen, however, if CB was associated with vasopressin and an osmotic gradient. The results suggest two points: a) the block of the hydrosmotic flow induced by CB is due to factors beyond the apical membrane; b) microfilaments may be important mechanochemical transducers in the chain of events leading to the hydrosmotic effect of vasopressin.
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    URL: http://dx.doi.org/10.1007/BF00219779
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    Elastic and strength properties of canine long bones (1977)
    Springer
    Medical & biological engineering & computing 15 (1977), S. 72-74 
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    ISSN: 1741-0444
    Keywords: Bone ; Elasticity ; Mechanical strength
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Summary The mechanical properties of canine long bones have been determined. The mean and standard deviation of the maximum load supported by six fresh canine femurs in 3-point bending was 1366±253 N. In all cases, the bones sustained a considerable amount of plastic deformation before failure. The modulus of elasticity (GN/m2), ultimate tensile stress (MN/m2) and yield stress (MN/m2) were 13·86, 108·3 and 88·3 for six humeral specimens and 13·88, 142·1 and 104·0 for 13 tibial specimens, respectively. The tibial specimens showed a statistically significant higher ultimate strength than the humeral specimens.
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    URL: http://dx.doi.org/10.1007/BF02441578
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    Instrumentation for measuring the tensile properties of femoral cortical bone (1977)
    Springer
    Medical & biological engineering & computing 15 (1977), S. 207-208 
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    ISSN: 1741-0444
    Keywords: Bone ; Instrumentation ; Tensile strength
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
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    URL: http://dx.doi.org/10.1007/BF02442967
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    The surface fine structure of the ependymal lining of the lateral ventricle in rats with hereditary hydrocephalus (1977)
    Springer
    Cell & tissue research 179 (1977), S. 121-129 
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    ISSN: 1432-0878
    Keywords: Lateral ventricle, rat ; Hydrocephalus ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ependyma of the lateral ventricle of rats with hereditary hydrocephalus was studied using scanning electron microscopy. Normal rats from the same litters were used as control animals. The surface morphology of the lateral ventricle of normal rats corresponded to results reported by other authors. The most prominent changes in the surface morphology of the ependyma of the hydrocephalic rats were seen in the cilia. They were shortened, fewer in number and clumped or matted. The surface of the ependymal cells was flattened and contained small, irregular projections. The number of large supraependymal cells, regarded as neurons, appeared to have diminished in the hydrocephalic rats. The number of supraependymal macrophages was greatly increased in these rats, suggesting the existence of an ependymitis.
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    URL: http://dx.doi.org/10.1007/BF00278467
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    Ciliary function of the frog oro-pharyngeal epithelium (1977)
    Springer
    Cell & tissue research 178 (1977), S. 267-278 
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    ISSN: 1432-0878
    Keywords: Ciliated epithelium, frog ; Cilia ; Coordination ; Mucous transport ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The palate epithelium of the frog was examined by scanning electron microscopy, light microscopy and high speed cine micrography. The cilia remain stationary for much of the time in the end-of-effective stroke position. Each beat cycle begins with a forwardly-directed recovery stroke lasting about 60 ms, followed by an effective stroke towards the oesophagus lasting about 12 ms. Activity can often be correlated with the presence of mucus, which is carried as strands on the tips of the ciliary effective strokes whilst the recovery strokes move beneath the mucus. Coordination of ciliary activity was very variable; local antiplectic metachrony of the recovery strokes could almost always be seen, and on very active epithelia effective strokes were associated with approximately diaplectic waves (either to left or right), but any particular pattern of coordinated activity was transient and quickly transformed to another pattern. Beating and coordination of these short cilia were compared with those of cilia propelling water.
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    URL: http://dx.doi.org/10.1007/BF00219053
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    Surface morphology of taste buds in catfish barbels (1977)
    Springer
    Cell & tissue research 178 (1977), S. 375-384 
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    ISSN: 1432-0878
    Keywords: Taste buds ; Fishes ; Neuroepithelium ; Microvilli ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary External taste buds abound on barbels of the adult catfish Corydoras arcuatus. When examined by scanning electron microscopy, they are visualized as a series of punctate, conical elevations projecting from the general surface epithelium. All taste buds were found to be of one type. Both their external and internal surface features could be clearly elucidated on intact barbels and in barbels fractured transversely at various positions along their length. An extensive nerve terminal network penetrates the base of each taste bud. Two populations of elongated cells bearing prominent microvilli project through the central pore at the tip of each bud. One set of microvilli is thicker, longer and more club-shaped than its counterpart. While both are randomly distributed within each central pore, the small, short microvilli appear to outnumber the larger ones. A third population of cells, devoid of any apical microvilli, was also seen in some of the taste buds examined internally. These cells do not project to the external surface and are interpreted as “basal” cells described in previous light and transmission electron microscope studies of taste buds in other vertebrate species. The functional significance of some of these morphological findings is discussed.
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    URL: http://dx.doi.org/10.1007/BF00218701
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    Vascularization of the pars distalis of the hypophysis in the toad, Bufo bufo (L.) (Amphibia, Anura) (1977)
    Springer
    Cell & tissue research 179 (1977), S. 1-10 
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    ISSN: 1432-0878
    Keywords: Hypophysis, pars distalis ; Bufo bufo (L.) ; Vascularization ; Corrosion casts ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The vascularization of the pars distalis of the hypophysis of the toad, Bufo bufo (L.), was studied by the traditional method of injecting a mixture of India-ink and gelatine into the circulatory system of the head via the arteria carotis communis. Further, methyl-methacrylate corrosion casts of the brains were made; the hypothalamo-adenohypophysial region of these corrosion casts was studied with the scanning electron microscope. The results showed that the portal vessels which arise from the median eminence do not supply distinct areas in the pars distalis as is supposed by the point-to-point-hypothesis. The portal vessels enter the ventro-median region of the pars distalis and branch off into a three-dimensional network of the secondary capillary plexus of the pars distalis. The plexus is made up mostly by four- to six-sided meshes. This angioarchitecture guarantees an optimal supply of the glandular cells of the pars distalis with nutritional factors and releasing hormones, on the one hand, and facilitates the removal of the hormones which are released by these cells, on the other hand. The venous drainage of the pars distalis is exerted mainly by two large veins, which bilaterally leave the dorso-lateral region (venous pole) of the pars distalis and by a few small veins, which drain into the wide, sinus-like vessel, which curves around the dorso-caudal region of the pars distalis and joins bilaterally the vena hypophysea transversa.
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    URL: http://dx.doi.org/10.1007/BF00278459
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    A scanning electron microscopic survey of the brain ventricular system of the female armadillo (1977)
    Springer
    Cell & tissue research 183 (1977), S. 531-539 
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    ISSN: 1432-0878
    Keywords: Brain ventricles ; Armadillo ; Ependyma ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The scanning electron microscope was used to survey the brain ventricular system of the female armadillo (Dasypus novemcinctus) with emphasis on the third ventricle. The walls of the lateral ventricles, aqueduct, and fourth ventricle are covered by long cilia. In the lateral ventricle, the cilia are arranged in groups; but in the aqueduct and fourth ventricle, they are evenly placed over the cellular surfaces. The ependymal cells of the third ventricle are densely ciliated except for the organum vasculosum and infundibular recess. The non-ciliated luminal surface of these areas has a pebblestone appearance punctuated by numerous microvilli and two types of supraependymal cells.
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    URL: http://dx.doi.org/10.1007/BF00225665
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    Discocilia—A new type of kinocilia in the larvae of Lanice conchilega (Polychaeta, Terebellomorpha) (1978)
    Springer
    Cell & tissue research 187 (1978), S. 271-280 
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    ISSN: 1432-0878
    Keywords: Kinocilia ; Discocilia ; Lanice conchilega ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Ein modifizierter Typ von Kinocilien wurde bei der Aulophoralarve des sedentären Polychäten Lanice conchilega gefunden. Für ihn wird die Bezeichnung „Discocilium” vorgeschlagen. Der einzige strukturelle Unterschied zu konventionellen Kinocilien besteht in der Ausbildung eines Köpfchens. Dieses Köpfchen wird vom distalen Ende des Cilienschaftes gebildet, der zu einer Öse gebogen ist, die von der Cilienmembran überzogen wird. Drei Haupttypen von Discocilien können unterschieden werden: a, Cilien mit geradem Axonem, deren Köpfchen durch eine Anschwellung der Membran entstehen, b, Cilien mit Köpfchen mit seitlichem gebogenem Axonem, c, Cilien, in denen das Axonem eine geschlossene Öse bildet. Die Discocilien sind nach dem verbreiteten 9+2 Filamentmuster aufgebaut. Ihr Köpfchen enthält keine Sekrete, es erscheint elektronenoptisch leer. Aufgrund ihrer Anordnung können zwei Typen von Discocilien unterschieden werden, nämlich isolierte Büschel, besonders am Vorderende, und segmentai angeordnete Cilienreihen. Ein möglicher Bildungsmodus der Discocilien wird beschrieben.
    Notes: Summary A modified type of kinocilia has been found in the Aulophora-larva of the sedentarian polychaete Lanice conchilega. For this newly described cilium type the term “discocilium” is proposed. The only structural difference from usual locomotory cilia is the tip, which possesses a discoidal head. The head is formed from the terminal part of the cilium shaft, which is bent to give rise to a loop-like ring covered by the ciliary membrane. Three types of discocilia can be distinguished: a) discocilia having swollen, bulblike heads with a central straight axoneme; b) discocilia having heads with a curved lateral axoneme and c) discocilia in which the axoneme forms a loop. The internal structure shows the usual 9+2 arrangement of the filaments. The head shows no signs of secretion; it appears structureless in electron microscopical examination. There are two kinds of discocilia arrangements: 1) isolated bunches of cilia especially at the tentacles and in the frontal region, and 2) segmental dorsal rows of cilia. The possible formation of discocilia is described.
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    URL: http://dx.doi.org/10.1007/BF00224370
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    Surface changes during development and involution of the cement gland of Xenopus laevis (1978)
    Springer
    Cell & tissue research 194 (1978), S. 303-313 
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    ISSN: 1432-0878
    Keywords: Cement gland ; Xenopus laevis ; Secretion ; Mucus ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The cement gland was studied from stage 17, when the anlage is established, to stage 49, shortly before its disappearance. At early stages, the apical membrane is covered by small microvilli that are more abundant than in the surrounding epiblast cells. Vesicular protrusions along the cell boundaries are also more numerous in the gland cells. When the gland reaches maturity, the apical membranes of gland cells differentiate into two regions. In the cranial, kidney-shaped region, the membranes are very narrow and protrude above the level of cell boundaries. Long and slender villi raise from the surface adjacent to cell boundaries. Apical surfaces in the caudal portion are larger and flattened. Cell boundaries are lined with shorter and thicker surface projections. At these stages, the bordering cells are covered with secretion vesicles. During involution the number of cells is progressively reduced. The area of the caudal portion increases relative to the area of the cranial portion. Apical surfaces become more flattened. Surface projections become much shorter and invade the whole of the apical surface. Bordering cells lose their secretion vesicles and their apical surface becomes ruffled with numerous short wrinkles. The significance of the apical structures and their evolution is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220397
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    Scanning electron microscopy of the respiratory surfaces of Saccobranchus (=Heteropneustes) fossilis (Bloch) (1978)
    Springer
    Cell & tissue research 195 (1978), S. 99-109 
    Details
    ISSN: 1432-0878
    Keywords: Gills ; Air-breathing organs ; Catfish, Saccobranchus fossilis ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The gill secondary lamellae are generally covered with epithelial cells whose outer surfaces form numerous microvilli. The surface of the primary lamellae is characterised by microridges. A particular type of surface sculpturing seems to be associated with given cell boundaries. Further evidence for the derivation of the air tube and fans which guard its entrance by modification of the basic gill structure has been obtained from both the gross surface architecture and microstructure of the individual cell surfaces. Secondary lamellae are represented by stubby projections which generally have a biserial arrangement. The outer surfaces of the epithelia overlying the capillaries of these respiratory islets are coated with microvilli as in the secondary lamellae. On the other hand, the relatively smooth-surfaced ‘lanes’ between groups of respiratory islets have a microridged surface similar to that of the primary gill lamellae. It is suggested that previous estimates of surface area, and consequently diffusing capacities of the air-breathing organ, have been low in view of the increased surface, due to both their gross and microstructure. Estimates for gill surface area may need very little correction as the spaces between the microvilli and microridges are probably filled with mucus under normal conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233679
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    Observations on the marginal ruffles of an established fibroblast-like cell line (1977)
    Springer
    Cell & tissue research 179 (1977), S. 225-234 
    Details
    ISSN: 1432-0878
    Keywords: Marginal ruffles ; Fibroblast-like cells ; Scanning electron microscopy ; Transmission electron microscopy ; Light microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary LW13K2 cells, a clone of a spontaneously in vitro transformed derivative of embryonic Lewis rat fibroblastic cells, were studied by phase contrast cine-light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The ruffles found at the advancing edge of cells grown on glass substrates in vitro form and recede in a period of less than one min if they do not make an attachment of the substrate. If they fail to make an attachment they may form pinocytotic channels near the leading edge as described by Price (1972) and/or collapse, generally backwards, towards the cell body. The ‘spines’ which appear to reinforce the membranous ruffles are the last structures to disappear, and accumulate in an irregular array behind the ruffling edge; this area is behind that in which pinocytosis occurs. In comparison with the sparse numbers of ribosomes found in the trailing edge, they are present in notable concentrations near the leading, ruffling edge of the cell. No membrane vesicles have been found in or near the ruffling edges at the ruffle-spine concentration zone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219798
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    The outer segments of photoreceptive pinealocytes in the pineal organ of the funa, Carassius gibelio langsdorfi (1978)
    Springer
    Cell & tissue research 186 (1978), S. 259-268 
    Details
    ISSN: 1432-0878
    Keywords: Pineal organ ; Carassius gibelio langsdorfi (Teleostei) ; Photoreceptive cell ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The form and size of the outer segments of photoreceptive pinealocytes in the pineal organ of the funa, Carassius gibelio langsdorfi, were observed with the scanning electron microscope. The height of the outer segments measures between 1 and 3 μm and the diameter varies widely from 1.5 to 8 μm. Various forms of outer segments, i.e. a slender type, a dome-like type, a cap-like type and a helical type, were demonstrated. The parallel-oriented filamentous processes of the inner segments have the same length as the outer segments and a diameter of approximately 100 nm; they are projections from the apical border of the inner segment and surround the cone-like outer segments. The processes make a right angle with the lamellar disks. The distance between two processes averages 100 nm. The lamellar disks of the outer segments are oriented at right angles to the modified cilium in the basal part, but the angle often changes in the peripheral part, where the lamellar disks are raised and become parallel to the cilium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225535
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    Surface fine structure of the subfornical organ in the Japanese quail, Coturnix coturnix japonica (1978)
    Springer
    Cell & tissue research 191 (1978), S. 389-404 
    Details
    ISSN: 1432-0878
    Keywords: Subfornical organ ; Japanese quail, Coturnix coturnix japonica ; Ultrastructure ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The surface ultrastructure of the subfornical organ (SFO) was investigated in the Japanese quail. The SFO consists of a body and a stalk. The body of the SFO can be divided into rostral and caudal parts. On the rostral part, each ependymal cell possesses a short central solitary cilium; clustered cilia are also occasionally seen. Microvilli are abundant. On the caudal part, cells with a solitary cilium are fewer in number, and clustered cilia are rarely found. Microvilli are not as abundant as on the rostral part. In addition, large bulbous protrusions, tufts of small protrusions, deep funnel-shaped hollows, small pinocytotic invaginations and possible cerebrospinal fluid-contacting axons are sporadically observed on the surface of various regions of the body. Each ependymal cell of the stalk has a wide apical surface. A central solitary cilium, microvilli and other structures are observed more rarely on the stalk than on the body, while clustered cilia are not seen on the stalk. These structures are compared with those of the mammalian SFO and further discussed in relation to the possible dipsogenic receptor function for angiotensin II.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219804
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    The epidermis and sensory organs of Dugesia tigrina (Turbellaria: Tricladida) (1978)
    Springer
    Cell & tissue research 193 (1978), S. 35-40 
    Details
    ISSN: 1432-0878
    Keywords: Planarian ; Scanning electron microscopy ; Epidermis ; Sense organs ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The epidermis of D. tigrina was examined using the scanning electron microscope. Both dorsal and ventral surfaces are extremely irregular in contour, as well as being permeated by large numbers of pores. Cilia are restricted to the ventral surface, the auricles and that part of the dorsum adjacent to the auricles. Club-shaped receptors, as well as cilia, were seen in the auricles. The epidermis anteriad to the eyespots is indistinguishable from that covering the remainder of the dorsal surface. Light rays could not enter the eyespot through this rough epidermal surface without becoming diffracted in an irregular fashion. It was therefore concluded that visual image perception is not a function of the planarian eyespot.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221599
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    Bovine olfactory and nasal respiratory epithelium surfaces (1978)
    Springer
    Cell & tissue research 193 (1978), S. 503-524 
    Details
    ISSN: 1432-0878
    Keywords: Cryo-ultramicrotomy ; High-voltage electron microscopy ; Scanning electron microscopy ; Olfactory epithelium ; Respiratory epithelium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary High-voltage transmission electron microscopy and cryo-ultramicrotomy together with scanning electron microscopy and some conventional transmission electron microscopy of ultrathin sections have been applied to the mucous surfaces of bovine olfactory and respiratory epithelia. Distal segments of olfactory cilia tend to run in parallel and could be followed over distances up to about 30 μm using high-voltage electron microscopy. This technique and scanning electron microscopy showed that on average 12–13 of such cilia could be observed per nerve ending. After correction for obscured cilia this number becomes about 17. High-voltage micrographs and micrographs made from sections prepared with a cryo-ultramicrotome showed the presence of electron-lucent pockets inside the olfactory mucus. The latter technique also showed that the mucus itself is not fibrous, but rather a continuum varying in electron density. The mucus layer contains various granular structures. Ciliary and microvillar membranes appear thicker with cryo-ultramicrotomy than when the sections are prepared with conventional techniques. The cores of the axonemal microtubules in olfactory as well as in respiratory cilia are darkly stained with this technique. Vesicles present inside the nerve endings are also darkly stained. Dimensions and some other numerical values of interest in olfaction are presented.
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    URL: http://dx.doi.org/10.1007/BF00225347
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    Vascularization of the pars intermedia of the hypophysis in the toad, Bufo bufo (L.) (Amphibia, Anura) (1977)
    Springer
    Cell & tissue research 179 (1977), S. 11-16 
    Details
    ISSN: 1432-0878
    Keywords: Hypophysis, pars intermedia ; Bufo bufo (L.) ; Vascularization ; Corrosion casts ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The vascularization of the pars intermedia of the hypophysis of the toad, Bufo bufo (L.) was studied by injection of a mixture of India-ink and gelatine into the circulatory system of the head via the arteria carotis communis. Further methyl-methacrylate corrosion casts of brains were made and the hypophysial region of the corrosion casts was examined with the scanning electron microscope. The results showed that the vascularization of the pars intermedia of the toad hypophysis consists of a single-layered vascular network, which is located on the ventral surface of the pars intermedia. The network is formed by capillaries, which primarily run caudally in a fan-like manner and which show only a few cross-connections. In the rostral region of the pars intermedia this network lies rather superficially, while in the caudal region it slightly penetrates the parenchyma. The vascular network originates from vessels of the neural stalk and from wide capillaries of the rostro-ventral region of the neurointermediate junction. The venous drainage of the pars intermedia is exerted by veins, which leave the caudal region and drain into the veins leaving the venous pole of the pars distalis. The fiat, wide meshed vascular net on the ventral side of the pars intermedia, demonstrated in this study, fits into the concept that the pars intermedia of the anuran hypophysis is under the control of nerve fibers coming from the hypothalamus.
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    URL: http://dx.doi.org/10.1007/BF00278460
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    The human vocal cord surface (1977)
    Springer
    Cell & tissue research 185 (1977), S. 279-283 
    Details
    ISSN: 1432-0878
    Keywords: Vocal cord epithelium (Human) ; Microridges ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The epithelium of the vocal cord from children and adults is analysed with SEM and TEM. Scanning micrographs show that the apical cell membrane is furnished with microvilli and microridges of various patterns. The function of microridges is discussed in relation to the distribution and retention of mucus on the vocal cord.
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    URL: http://dx.doi.org/10.1007/BF00220671
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    Some morphological observations on osteoclasts (1977)
    Springer
    Cell & tissue research 185 (1977), S. 387-397 
    Details
    ISSN: 1432-0878
    Keywords: Osteoclasts ; Resorption ; Bone ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Osteoclasts of the peripheral portions of the endocranial aspect of young rat parietal and frontal bones were studied by scanning electron microscopy of glutaraldehyde fixed, critical point dried specimens. These studies show Osteoclasts to have a much more complicated form than has previously been realised. Extensively branching, elongated, smooth-surfaced cells, which are for the most part elevated above the level of the surrounding bone matrix surface and sometimes above portions of osteoblasts or other osteoclasts, were identified as motile non-resorbing cells. Portions of the former and other entire cells may be embowered in Howship's lacunae, have microvilli on their dorsal surface, and are surrounded by a serrated border of microprojections which have an apparently firm attachment to the matrix surface. Osteoclasts in short term culture show additional free surface ruffles which are not encountered in specimens taken fresh from the animal. No evidence of recruitment of osteoblasts or osteocytes into osteoclasts was found. Disinterred osteocytes retained an ability to migrate from their lacunae on to surrounding bone matrix surface.
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    URL: http://dx.doi.org/10.1007/BF00220298
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    Ultrastructural alterations in ciliary cells exposed to ionizing radiation (1977)
    Springer
    Cell & tissue research 180 (1977), S. 421-431 
    Details
    ISSN: 1432-0878
    Keywords: Ciliated cells ; Trachea ; Radiation effects ; Scanning electron microscopy ; Transmission electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Early effects of ionizing radiation were investigated in an experimental in vitro system using the ciliary cells of the tracheal mucous membrane of the rabbit, irradiated at 30° C and at more than 90% humidity. The changes in physiological activities of the ciliary cells caused by irradiation were continuously registered during the irradiation. The specimens were examined immediately after irradiation electron microscopically. The morphological changes in irradiated material after 10–70 Gy are compared with normal material. After 40–70 Gy, scanning electron microscopy revealed the formation of vesicles on cilia, and club-like protrusions and adhesion of their tips. After 30–70 Gy, a swelling of mitochondrial membranes and cristae was apparent transmission electron microscopically. The membrane alterations caused by irradiation are assumed to disturb the permeability and flow of ATP from the mitochondria, which in turn leads to the recorded changes in the activity of the ciliated cells.
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    URL: http://dx.doi.org/10.1007/BF00220165
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    The vascularization of the neural stalk and the pars nervosa of the hypophysis in the toad, Bufo bufo (L.) (amphibia, anura) (1977)
    Springer
    Cell & tissue research 180 (1977), S. 433-442 
    Details
    ISSN: 1432-0878
    Keywords: Hypophysis, neural stalk, pars nervosa ; Bufo bufo (L.) ; Vascularization ; Corrosion casts ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The angioarchitecture of the neural stalk and the encephalo-posthypophysial portal system of the hypophysis of the toad, Bufo bufo (L.), was studied using three different methods. The neural stalk is mainly supplied by branches of the arteria infundibularis superficialis which form a widemeshed vascular network. Dorsally this network continues into the plexus of the pars nervosa. The vascularization of the pars nervosa is made up of the encephalo-posthypophysial portal system. This portal system consists of a hypothalamic branch (=portion), a mesencephalic and a mesencephalic-bulbar branch (=portion). The hypothalamic branch was found to drain the pars ventralis of the tuber cinereum as well as more dorsal regions of the diencephalon. The mesencephalic-bulbar trunk enters the hypothalamic branch. The resulting common stem of the encephalo-posthypophysial portal vein then curves around the retroinfundibular communicating artery, crosses its ventral side and runs caudally. The secondary capillary plexus of the pars nervosa is characterized by well defined capillary networks which are located at the periphery of the parenchyma of the pars nervosa, thus forming a rostral, dorsal and ventro-caudal net. The central region of the parenchyma of the pars nervosa is supplied only by main branches of the encephalo-posthypophysial portal vein. The venous drainage of the pars nervosa is via the vena hypophysea transversa.
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    URL: http://dx.doi.org/10.1007/BF00220166
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    Role of carbohydrate-protein complexes in the organization of the microstructure of fibrous connective tissue (1978)
    Springer
    Bulletin of experimental biology and medicine 86 (1978), S. 1663-1665 
    Details
    ISSN: 1573-8221
    Keywords: Scanning electron microscopy ; connective tissue ; collagen fiber ; protorysin ; trypsin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Samples of tendon and fascia, treated with enzymes possessing amylolytic and proteolytic activity (protorysin, trypsin) were investigated by scanning electron microscopy. Destruction of carbohydrate-protein complexes leads to disappearance of the characteristic morphological features of the collagen fibers. Construction of the collagen fiber was shown to be based on a network of thin anastomosing fibrils, forming a carcass connected with the carbohydrate-protein matrix. It is argued that the reticular structure is a general principle in the structural organization of fibrous connective tissues.
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    URL: http://dx.doi.org/10.1007/BF00801834
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