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  • Bone  (222)
  • Chromatographie, Dünnschicht  (138)
  • Neurosecretion  (85)
  • Springer  (445)
  • American Geophysical Union
  • Irkutsk : Ross. Akad. Nauk, Sibirskoe Otd., Inst. Zemnoj Kory
  • Krefeld : Geologischer Dienst Nordhein-Westfalen
  • Wiley
  • 2015-2019
  • 1975-1979  (193)
  • 1970-1974  (252)
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  • 1
    Digitale Medien
    Digitale Medien
    Radioautographic visualization of3H-fucose incorporation into glycoprotein by osteoblasts and its deposition into bone matrix (1979)
    Springer
    Calcified tissue international 27 (1979), S. 177-185 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Calcification ; Bone ; Glycoprotein ; Golgi ; Osteoblasts
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary The elaboration of bone matrix glycoprotein by osteoblasts of alveolar bone was investigated by radioautography after the intravenous injection of3H-fucose into young rats. At selected times after injection, animals were sacrificed by intracardiac perfusion and demineralized specimens were prepared for light and electron microscope radioautography. At 5 and 10 min after injection, when the blood fucose level was high, silver grains were restricted to the spheroidal and cylindrical saccules of the Golgi apparatus. At 20 min membrane-limited secretory granules were also labeled. By 35 min, the blood fucose level had dropped and silver grains were detected over the apical cortical cytoplasm, in association with secretory granules located therein. Some grains were present over osteoblast processes and the adjacent prebone matrix. By 4 h most of the silver grains had left the cell. At that time they were observed over prebone, adjacent to osteoblast processes, as well as over the prebone-bone junction where a distinct band of label was noted. In demineralized preparations an electron-dense granular material was present at the prebone-bone junction in association with collagen fibrils. These findings provide evidence that osteoblasts in alveolar bone synthesize fucose-containing glycoprotein and indicate that the addition of3H-fucose occurs in the Golgi apparatus. The glycoprotein passes to the apical cortical cytoplasm by way of membrane-limited secretory granules, is exteriorized, and accumulates at the site where prebone transforms into bone (the prebone-bone junction). Since this is also the site of the calcification front, the deposition of labeled glycoprotein may be related to the deposition of bone mineral.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02441182
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  • 2
    Digitale Medien
    Digitale Medien
    Bone fluoride concentrations associated with fluoridated drinking water (1979)
    Springer
    Calcified tissue international 27 (1979), S. 95-99 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Bone ; Fluoride ; Analysis ; Food ; Age
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Recently published bone fluoride values from Iowa are very high compared to earlier reports, suggesting an increase in fluoride intake. Reanalysis of the Iowa specimens shows levels one-fourth those reported by the Iowa laboratory indicating an error in the original report. Seventeen bone specimens, collected from long-term residents of Rochester, New York, drinking 1 ppm F− water, had a mean value of 2085±270 ppm F− on an ashed-weight basis. This value is not significantly different from that predicted by the data of Zipkin et al. in 1958. These data, therefore, do not support the contention that there has been an increase in fluoride intake.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02441168
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  • 3
    Digitale Medien
    Digitale Medien
    Use of a spectrophotometer for radiographic photodensitometry of bone (1979)
    Springer
    Calcified tissue international 28 (1979), S. 103-105 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Bone ; Photodensitometry, X-ray ; Radiography ; Spectrophotometry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary A conventional spectrophotometer was used to do radiographic photodensitometry of bone mass. An experiment to produce osteoporosis in guinea pigs required quantification of changes in bone mass. Lack of a densitometer necessitated finding another method for quantification. The method developed involved using industrial film in a closed X-ray system. Optical density of X-rays was then read in a spectrophotometer at nine femur locations. Highly significant correlations between optical density and femur calcium content and femur dry weight per millimeter were obtained. Histological sections from an animal with low optical density measurements confirmed bone loss by showing decreased cortical width and loss of trabecular bone. In addition to using readily available equipment, this method offers the advantage of being able to detect bone loss in specific areas of the bones. In addition, bones are left intact and can be used for other purposes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02441227
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  • 4
    Digitale Medien
    Digitale Medien
    Analysis of paramagnetic centers in X-ray-irradiated enamel, bone, and carbonate-containing hydroxyapatite by electron spin resonance spectroscopy (1979)
    Springer
    Calcified tissue international 28 (1979), S. 107-112 
    Details
    ISSN: 1432-0827
    Schlagwort(e): ESR ; Bone ; Enamel ; CO3-Apatite ; Paramagnetism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Carbonate-containing hydroxyapatite, enamel, and bone were irradiated by an X-ray and investigated between 77° and 350°K by means of electron spin resonance (ESR) spectroscopy. The ESR spectrum of enamel irradiated at 77°K in vacuum and observed at the same temperature was almost the same as that of the carbonate-containing hydroxyapatite. The temperature dependence of signal intensities confirms a spin-energy exchange between the mineral and organic constituents in bone, but in enamel no or very little spinenergy exchange between the mineral and organic constituents. Considerable similarity among the ESR spectra of enamel, bone, and carbonate-containing apatite was obtained after X-ray irradiation in air at 300°K with both an X-band and a Q-band ESR spectrometer. The Q-band spectrum can be interpreted in terms of two paramagnetic species. One is identified as a CO 3 3− anion radical which has an axial symmetry withg factors of 2.0029 and 1.9972. The other species is found to be centered atg=2.0019.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02441228
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  • 5
    Digitale Medien
    Digitale Medien
    On the solid state of bone (1979)
    Springer
    Calcified tissue international 28 (1979), S. 33-36 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Infrared, visible light ; Bone ; Collagen ; Apatite
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Abstract Photovoltaic effect (infrared and visible light) is observed in bone and its two major components, collagen and apatite, at room temperature. A dimunition in the magnitude of photovoltage is observed after exposure to ultraviolet light in all the cases. The drift mobility of the charge carriers is obtained by measuring I versus V relationships in sandwich samples and relating them to the permitivity of the medium. Lifetime of the injected carriers is measured in the usual way. The data are consistent with the hypothesis that the effects are due to protonic conduction phenomena.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02441215
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  • 6
    Digitale Medien
    Digitale Medien
    Growth of embryonic chick tibiae in ovo and in vitro: A scanning electron microscope study (1979)
    Springer
    Calcified tissue international 27 (1979), S. 33-40 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Chick embryo ; Bone ; Organ culture ; Scanning electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary The study describes the ultrastructure of the mineralized portion of chick tibiae from 10 days in ovo to 2 days post-hatch. At 10 days a single mineralized cylinder surrounds the diaphysis. On its outer surface columnar trabeculae join to form ridges parallel to the long axis of the bone. These ridges are covered by another cylinder and form the haversian canals. At 11 days vascular invasion of the marrow cavity occurs and resorption of the endosteal surface begins. This type of periosteal deposition and endosteal resorption is repeated during and subsequent to embryonic development. The mineralized portion of 10-day chick tibiae cultured for 2 days in modified BGJ medium was compared with 10-, 11-, and 12-day tibiae in ovo. Cultured tibiae were similar in length and calcium content to 11-day tibiae in ovo. The form of mineral deposited in ovo and in culture was the same, namely, aggregates of spherical mineral clusters. Differences in culture included the following: (a) few concentric cylinders were deposited as compared with tibiae in ovo; (b) trabeculae were not arranged in rows and ridges in culture; (c) osteocytic lacunae were restricted to bases of trabeculae rather than uniformly distributed as in ovo; and (d) the endosteal surface of tibiae in culture appeared etched.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02441158
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  • 7
    Digitale Medien
    Digitale Medien
    An ultrastructural study of the role of calcification nodules in the mineralization of woven bone (1979)
    Springer
    Calcified tissue international 27 (1979), S. 57-64 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Bone ; Bone formation ; Calcification ; Calcification nodule ; EM
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Osteolathyrism has been used as an experimental model for the study of calcification nodules during the mineralization process. Periosteal exostoses developing in osteolathyrism characteristically have spherical basophilic structures (calcification nodules) in the vicinity of developing bone spicules. In thin sections, the nodules were seen scattered between collagen fibers in the intercellular matrix. Collagen fibers did not appear to be present within the nodules but sometimes were packed just outside them. Matrix vesicles were also present in areas of early mineralization. After EDTA decalcification, the majority of the nodules consisted of a fine granular material surrounded by an electron-dense peripheral zone. The peripheral dense zone was occasionally incomplete in small nodules in areas of early mineralization. An electron-dense central area could be observed in the center of the nodules. Evidence has been presented indicating that the calcification nodules arise from smaller mineralization foci, presumably matrix vesicles. The calcification nodules enlarge to approximately 1.0 µm in size, at which point development is slowed or halted allowing the formation of the peripheral dense zone. Although coalescence of nodules was observed, this was more a random event. The further mineralization of the trabeculae was achieved by the calcification of the collagen fibers. The mineralized trabeculae reflected this pattern of nodular and collagenous calcification. It is suggested that this pattern of calcification is characteristic of rapidly developing woven bone.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02441162
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  • 8
    Digitale Medien
    Digitale Medien
    Age-related changes in the density and tensile strength of human femoral cortical bone (1979)
    Springer
    Calcified tissue international 27 (1979), S. 105-108 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Bone ; Femur ; Strength ; Density ; Age
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary In order to ascertain whether the intrinsic strength of human bone changes with age or not, we have determined the ultimate tensile strength and density of strips of femoral cortical bone. These femora were collected from cadavers varying in age from 13 to 97 years. The results show that both density and intrinsic strength of bone increase up to about the fourth decade of life and then decrease with age. However, the rate of decrease of strength is greater than that of density. This indicates that the density of bone is not the sole determining factor of its strength, and that some other factors play an important part.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02441170
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  • 9
    Digitale Medien
    Digitale Medien
    Distribution of the perilacunar hypomineralized areas in cortical bone from patients with familial hypophosphatemic (vitamin D-resistant) rickets (1979)
    Springer
    Calcified tissue international 27 (1979), S. 101-104 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Bone ; Rickets ; Hypophosphatemia ; Microradiography ; D-resistance
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary The perilacunar areas of low mineral density in microradiographs from cortical bone of patients with hypophosphatemic (vitamin D-resistant) rickets are not evenly distributed throughout the bone tissue. Their frequency and distribution were determined in bone from 9 patients with this disease. It was found that the lesion was more frequent in haversian bone than in interstitial bone, and along the inner circumference of growing haversian systems as compared with the outer circumference. These findings indicate that the lesion is the result of retarded mineralization, and that mineralization slowly proceeds in these areas as the bone becomes older. A relatively high frequency of the lesion was also found in osteons with an elliptical cross section along the long axis of the ellipse. The cause of the abundance of the lesion at these sites is not clear, but it is possible to explain the uneven distribution in elliptical osteons by assuming an unequal rate of bone formation in these structures.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02441169
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  • 10
    Digitale Medien
    Digitale Medien
    Effect of carbon dioxide and various oxygen tensions on the respiratory activity of bone (1979)
    Springer
    Calcified tissue international 27 (1979), S. 165-169 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Oxygen uptake ; Bone ; Oxygen tension ; Carbon dioxide
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary The present study was carried out to determine the influence of carbon dioxide and oxygen tension on the respiratory activity of bone cells in mouse calvaria in vitro. Five-day-old mouse calvaria were removed aseptically and incubated individually for 1 h at 37° C in a closed reaction chamber containing 1.5 ml of tissue culture medium made up of 60% horse serum in Gey's solution containing 100 unit/ml penicillin and 100µg/ml streptomycin. Before the calvaria were added, the medium in the incubation chamber was equilibrated with 10%, 20%, 30%, or 50% oxygen balanced with nitrogen. The effect of CO2 on oxygen utilization by the calvaria was determined by incubating the calvaria in a medium previously equilibrated with either 50% O2 balanced with N2 or 50% O2 and 5% CO2 balanced with N2. At each oxygen tension, the rate of oxygen utilization by the calvaria was measured polarographically by a Clark oxygen electrode. The results showed that the rate of oxygen uptake of bone increased as the oxygen tension increased and carbon dioxide stimulated significantly the rate of oxygen utilization by the bone cells. In view of the previous reports that both carbon dioxide and oxygen tension are implicated in the process of bone resorption, it is suggested that these two factors may affect bone resorption by influencing the oxygen utilization by bone cells and ultimately controlling their energy metabolism.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02441180
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  • 11
    Digitale Medien
    Digitale Medien
    X-ray diffraction of the calcified tissues inPolypterus (1979)
    Springer
    Calcified tissue international 28 (1979), S. 37-42 
    Details
    ISSN: 1432-0827
    Schlagwort(e): X-ray diffraction ; Hydroxyapatite ; Whitlockite ; Fish (Pisces) ; Bone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Pyrolyzed scales, fin spines, and bone from the ray-finned bony fishPolypterus (Actinopterygii) showed two mineral phases on X-ray diffraction: hydroxyapatite (HA), Ca5(PO4)3OH, and whitlockite, Ca3(PO4)2. The ratio of HA/whitlockite varied with the structure (scale, spine, bone) within each individual fish. The relative proportions of HA to whitlockite in pyrolyzed samples reflected the Ca/P ratio of the sample. Whitlockite appears after pyrolysis when the Ca/P is lower than 1.67. Among the five fish investigated, for each structure a general trend was noted. The proportion of HA relative to whitlockite increased with size (age) of the fish. Thus the smallest fish, a juvenile, exhibited a low Ca/P mineral in its calcified tissues, whereas the larger fish had progressively more HA and less whitlockite.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02441216
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  • 12
    Digitale Medien
    Digitale Medien
    Disordered mineral metabolism produced by ketogenic diet therapy (1979)
    Springer
    Calcified tissue international 28 (1979), S. 17-22 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Anticonvulsant ; Ketogenic diet ; Calcium ; Vitamin D ; Bone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Vitamin D and mineral metabolism status was examined in five children maintained chronically on combined ketogenic diet-anticonvulsant drug therapy (KG), and the results compared to those obtained in 18 patients treated with anticonvulsant drugs alone (AD) and 15 normal controls. KG patients exhibited biochemical findings of vitamin D deficiency osteomalacia: decreased serum 25-hydroxyvitamin D (25OHD) and calcium concentrations, elevated serum alkaline phosphatase and parathyroid hormone concentrations, decreased urinary calcium and increased urinary hydroxyproline excretion, and decreased bone mass. Although the KG and AD groups demonstrated similar reductions in serum 25OHD concentration, the KG patients exhibited a significantly greater reduction in bone mass. In response to vitamin D supplementation (5000 IU/day), mean bone mass in the KG group increased by 8.1±0.9% (P〈0.001) over a 12-month period. These results suggest that ketogenic diet and anticonvulsant drug therapy have additive deleterious effects on bone mass and that these effects are partially reversible by vitamin D treatment.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02441213
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  • 13
    Digitale Medien
    Digitale Medien
    Effects of osteoclast activating factor from human lymphocytes on cyclic AMP concentrations in isolated mouse bone and bone cells (1979)
    Springer
    Calcified tissue international 28 (1979), S. 23-32 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Bone ; Bone cells ; Cyclic AMP ; Osteoclast activating factor ; Lymphokine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Osteoclast activating factor (OAF) is a lymphokine which may participate in the pathologic destruction of bone observed in a number of disorders. In the current studies, we investigated the action of OAF on cAMP accumulation by bones and isolated bone cells in culture. OAF was shown to stimulate accumulation of cAMP in mouse cranial bones at doses between 1 and 1000 ng/ml. Stimulation of bone resorption was observed in bones treated with the same doses of OAF. In order to investigate the cell types responsible for cAMP responses to OAF, we isolated bone cells and grew them in monolayer culture. The cells were isolated by a variety of techniques which separate bone cells into two types of parathyroid hormone (PTH)-responsive populations: (a) cells derived from the periosteal regions of the bone, which also respond to calcitonin with increases in cAMP; and (b) cells derived from the matrix, which do not respond to calcitonin. OAF caused elevation of cAMP levels in both the periosteum-derived cells and the matrix-derived cells. The magnitudes and time courses of OAF effects in these populations resembled the effects previously reported for PTH in the same populations. OAF stimulated adenyl cyclase in both types of cell populations, but did not produce significant changes in cAMP phosphodiesterase activity. OAF differed from PTH in that its effects on cAMP accumulation decreased sharply at supramaximal doses in both bone and isolated cells, especially in the matrix-derived populations. Bone resorption did not decrease as markedly as did cAMP accumulation at high doses of OAF, suggesting that cAMP accumulation and resorption could be dissociated under some conditions. These results indicate that OAF has effects on cAMP production in the same cell populations as PTH, and suggest that OAF could modify not only resorption but also formation of bone in vivo. OAF may exert its effects on bone by means of cAMP-dependent mechanisms, but more data will be necessary to establish this unequivocally. The observed differences between OAF and PTH may be of relevance in the mechanism and treatment of pathologic bone destruction in vivo.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02441214
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  • 14
    Digitale Medien
    Digitale Medien
    Bone metabolism, parathyroid hormone, and calcitonin in paraplegia (1979)
    Springer
    Calcified tissue international 27 (1979), S. 199-204 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Bone ; Parathyroid hormone ; Calcitonin ; Osteoporosis ; Paraplegia ; Hydroxyproline
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary In paraplegia, osteoporosis below the neurological lesion occurs early after the spinal cord affection. The serum levels of parathyroid hormone (PTH) and calcitonin (CT), using a radioimmunoassay for the measurement of immunoreactivity, were studied in 12 paraplegic patients for 9 months following onset. Serum Ca and P levels, urinary hydroxyproline excretion, and the kinetic metabolic clearance of45Ca have also been measured. P and immunoreactive (i) CT levels were found the highest at the beginning of the observation and progressively decreased with time. Ca and iPTH serum levels varied inversely with time, the highest level of Ca and the lowest level of iPTH being recorded at the third month following the paraplegia. Mean values of Ca, iPTH, and iCT were in the normal range throughout the study. P levels were increased during the first 3 months. Hydroxyprolinuria was also high and45Ca kinetics showed increased values of Vt, Vo+, and Vu. These parameters indicate a high degree of bone turnover. The results were consistent with the assumption that PTH is not responsible for the increased resorption of bone in paraplegia. Likewise, a deficiency of CT does not seem to be responsible for this bone resorption. These endocrine modifications could be secondary to an increase in the calcium flux from bone to blood and resulting from bone destruction as attested by the increase of urinary calcium and urinary hydroxyproline excretion.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02441186
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  • 15
    Digitale Medien
    Digitale Medien
    Bone maturation in the vitamin D, phosphate deficient rat and the response to acid loading (1979)
    Springer
    Calcified tissue international 27 (1979), S. 233-237 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Bone ; Vitamin D ; Acidosis ; Phosphate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Vitamin D and phosphate deficiency were produced in rats in order (a) to evaluate the degree of bone mineral and matrix maturation using a bromoform/toluene density gradient technique; and (b) to compare the aforementioned bone maturational changes due to vitamin D and phosphate deprivation to those produced with superimposed severe acidosis. Rats were fed a diet deficient in vitamin D and phosphorus (0.2%) from 3 weeks through 7 weeks of age. To examine the additional contribution of dietary calcium, we gave one-half of the animals either a low (0.06%) or high (1.3%) calcium diet. Following the 4 weeks of vitamin D deficiency, one-half of each group was given 1.8% NH4Cl in the drinking water for 4 succeeding days to induce an acute, severe acidosis. The degree of bone maturation was quantitated via bromoformtoulene density gradient fractionation; total mineral and hydroxyproline (collagen) levels were quantitated as well. The vitamin D-deficient rats deprived of adequate dietary phosphate responded by conserving phosphorus, and as a consequence total bone phosphorus levels were maintained within that level for control rats. This conservation was independent of calcium intake but was extremely sensitive to acute acid loading, where a significant reduction in total bone phosphorus was noted. The bone maturational profile obtained from the vitamin D-phosphate deficient rats, however, revealed a significant accumulation of less mature or dense bone collagen and mineral with a corresponding decrease in the most mature or dense moieties. In contrast to the reduction of the total bone phosphorus content by acute acidosis, the skeletal collagen-mineral maturational profile was not significantly affected by the short-term systemic acidosis. The observed retardations in the bone collagen and mineral maturation of the vitamin D-deficient, phosphate-deprived state provide an additional observation which may well relate to the progressive osteopenia documented in states of chronic, mild acidosis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02441191
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  • 16
    Digitale Medien
    Digitale Medien
    Changes in proline synthetic and degradative enzymes during matrix-induced cartilage and bone formation (1979)
    Springer
    Calcified tissue international 27 (1979), S. 275-279 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Proline ; Cartilage ; Bone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Proline biosynthetic and degradative enzymes are unevenly distributed in differentiated mammalian tissues. Activities of the synthetic enzymes are relatively high in collagenous tissues, whereas activities of the degradative enzymes are high in noncollagenous tissues. In order to further characterize tissue-specific proline biosynthesis and degradation, we have determined proline enzyme activities during cartilage and bone formation induced by demineralized bone matrix. We can thus follow temporal changes in enzyme activity in a single tissue as different cell types develop. Ornithine aminotransferase and pyrroline-5-carboxylate reductase have peaks of activity which correlate with maximal type II collagen synthesis by chondrocytes. Both enzymes also are active during bone formation. In contrast, proline oxidase and pyrroline-5-carboxylate dehydrogenase are present at low levels and do not change as new cell types appear. Arginase activity peaks during the first 3 days and then rapidly decreases by the time cartilage and bone formation begin. These observations further substantiate the importance of proline biosynthesis in collagenous tissues. The close correlation between ornithine aminotransferase activity and type II collagen synthesis suggests that the pathway from ornithine to proline may be especially important during formation of type II collagen.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02441197
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  • 17
    Digitale Medien
    Digitale Medien
    Noninvasive measures of bone bending rigidity in the monkey (M. nemestrina) (1979)
    Springer
    Calcified tissue international 27 (1979), S. 109-115 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Bone ; Bending rigidity ; Disuse atrophy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary The in vivo bending rigidity and bone mineral content of monkey ulnae and tibiae were measured. Bending rigidity in the anteroposterior plane was measured by an impedance probe technique. Forced vibrations of the bones were induced with an electromechanical shaker, and force and velocity at the driving point were determined. The responses over the range of 100–250 Hz were utilized to compute the bending rigidity. Bone mineral content in the cross section was determined by a photon absorption technique. Seventeen male monkeys (Macaca nemestrina) weighing 6–14 kg were evaluated. Repeatability of the rigidity measures was 4%. Bone mineral content was measured with a precision of 3.5%. Bending rigidity was correlated with the mineral content of the cross section,r=0.899. Two monkeys were evaluated during prolonged hypodynamic restraint. Restraint produced regional losses of bone most obviously in the proximal tibia. Local bone mineral content declines 17 to 24% and the average bending rigidity declines 12 to 22%. Changes in bones leading to a reduction in mineral content and stiffness are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02441171
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  • 18
    Digitale Medien
    Digitale Medien
    Anticonvulsant drug-induced osteomalacia: Alterations in mineral metabolism and response to vitamin D3 administration (1979)
    Springer
    Calcified tissue international 27 (1979), S. 13-18 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Anticonvulsants ; Calcium ; Vitamin D ; Parathyroid hormone ; Bone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Parameters of mineral metabolism were examined in 6 patients with moderately severe anticonvulsant drug-induced osteomalacia. Compared to 15 matched controls, the patients exhibited significantly reduced serum calcium, inorganic phosphate, and 25-hydroxyvitamin D concentration, elevated serum alkaline phosphatase and immunoreactive parathyroid hormone (iPTH) concentration, reduced intestinal47Ca absorption, reduced urinary calcium and increased urinary hydroxyproline excretion, and reduced forearm bone mass. Intestinal absorption of vitamin D3 was normal. Following 4 months of treatment with vitamin D3 (4000 units/day), serum 25-OHD concentration was increased to 3 times mean normal values and all parameters except serum iPTH, urinary calcium excretion, and forearm bone mass were returned to levels not significantly different from normal. Serum iPTH concentration was reduced by 39% (P〈0.05); 24-h urinary calcium excretion rose by 98% (P〈0.001), and forearm bone mass increased by 5.6% (P〈0.05). It is concluded that moderate-dose vitamin D3 supplementation is effective in normalizing parameters of mineral metabolism in this disorder, despite evidence of resistance to the biologic effects of vitamin D.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02441155
    Standort Signatur Erwartet Verfügbarkeit
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  • 19
    Digitale Medien
    Digitale Medien
    The calciuria of increased fixed acid production in humans: Evidence against a role for parathyroid hormone and 1,25(OH)2-vitamin D (1979)
    Springer
    Calcified tissue international 28 (1979), S. 233-238 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Calcium ; PTH ; 1,25(OH)2D ; Acid ; Bone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary We measured mineral and acid balances, serum iPTH, urinary cAMP/creatinine, and plasma concentrations of 25OHD and 1,25(OH)2D in 7 healthy adults during control conditions and during increased fixed acid production achieved either by the administration of NH4Cl (N=3) or by increased dietary protein intake (N=4). When acid production was increased, the subjects were in positive acid balance and negative Ca balance because of increased urinary Ca excretion. Serum iPTH fell slightly but urinary cAMP and the plasma levels of vitamin D metabolites did not change. We conclude that the accelerated skeletal and urinary losses of Ca that occur when fixed acid production is increased are not contributed to nor compensated for by the parathyroid-vitamin D endocrine systems.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02441241
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  • 20
    Digitale Medien
    Digitale Medien
    The occurrence of chondroitin-6-sulphate in adult human compact bone tissue (1979)
    Springer
    Calcified tissue international 29 (1979), S. 169-171 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Glycosaminoglycans ; Bone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Compact bone tissue chondroitin sulphate, previously considered to be pure chondroitin-4-sulphate, was isolated from three adult human femoral diaphyses and digested with chondroitinase ABC. Assaying these digests by means of high performance liquid chromatography we could demonstrate that 12 to 14% of the disaccharide residues were 6-sulphated. The 4/6-ratios were also studied in chondroitin sulphate fractions of different molecular size. Slightly increasing amounts of 6-sulphated disaccharides were found with increasing size of the chondroitin sulphates.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02408073
    Standort Signatur Erwartet Verfügbarkeit
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  • 21
    Digitale Medien
    Digitale Medien
    Effects of changing hydrogen ion, carbonic acid, and bicarbonate concentrations on bone resorption in vitro (1979)
    Springer
    Calcified tissue international 29 (1979), S. 7-13 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Bone ; Culture ; Resorption ; Acidosis ; Alkalosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary We have examined the effects of H+, CO2, and HCO3 − concentrations during metabolic and respiratory acidosis and alkalosis on bone resorption in vitro. Rat fetal bones prelabeled with45CaCl2 were cultured at 2%, 5%, and 10% CO2 for up to 120 h, and the release of45Ca was measured in devitalized bones (non-cell-mediated45Ca release) and in live bones (cell-mediated45Ca release) cultured with or without PTH and 1,25(OH)2D3. Non-cell-mediated mineral loss was linearly related to H+ concentration but not to CO2 or HCO3 − concentration. This effect was observed on both labeled and stable calcium. Over a wide pH range (6.9–7.5) H+, CO2, or HCO3 − concentrations did not influence cell-mediated bone resorption in control or in PTH-and 1,25(OH)2D3-stimulated cultures. However, inhibition of cell-mediated bone resorption was observed at higher or lower pH irrespective of CO2 or HCO3 − concentrations. These observations demonstrate that the bone mineral mobilizing effect of acidosis in vitro is mainly due to the effect of changing H+ concentration on devitalized bone. Effects on cell-mediated bone resorption and hormonal response were observed only at extremes of pH. The effects of H+ were independent of changes in CO2 or HCO3 − concentration and could be responsible for the negative calcium balance and increased urinary loss observed in metabolic acidosis in vivo, but do not explain the reported differences in effects on calcium metabolism between respiratory and metabolic acidosis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02408049
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  • 22
    Digitale Medien
    Digitale Medien
    Identification and detection of carbamate pesticides in autopsy tissues using thin-layer chromatography (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 287-287 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Nachw. von Carbamatpesticiden in biolog. Material ; Chromatographie, Dünnschicht
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00481656
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  • 23
    Digitale Medien
    Digitale Medien
    Information content and equivocation of TLC identification procedures (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 361-365 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Chromatographie, Dünnschicht ; Informationsgehalt und »Äquivokation«
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Summary A method has been developed for the calculation of information contents of one-channel identification procedures, which is especially applicable in the area of thin-layer chromatography (TLC). The method can be considered as a refinement of the one proposed by Massart and can easily be extended to the combination of one-channel procedures. In addition, the quantity ‘equivocation’, which is complementary to the information content, is introduced. As an example the best TLC-systems and the best combinations of two TLC-systems for the identification of DDT and twelve related compounds are selected by using information contents or equivocations. The results for the individual systems are compared with those obtained by Massart.
    Notizen: Zusammenfassung Eine Methode zur Berechnung von Informationsgehalten von Einkanal-Identifizierungsverfahren wurde entwickelt, die besonders gut für das Gebiet der Dünnschicht-Chromatographie (DC) anwendbar ist. Sie kann als eine Verfeinerung der von Massart vorgeschlagenen Methode angesehen werden und kann auf einfache Weise für Kombinationen von Einkanal-Verfahren erweitert werden. Dabei wird der Begriff »Äquivokation«, komplementär zum Informationsgehalt, eingeführt. Als Beispiel wurden die besten DC-Systeme und Kombinationen von zwei DC-Systemen für die Identifizierung von DDT und zwölf verwandten Verbindungen unter Benutzung von Informationsgehalten oder »Äquivokationen« ausgewählt. Die Ergebnisse für die einzelnen Systeme werden mit den nach Massart gefundenen verglichen.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00468523
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  • 24
    Digitale Medien
    Digitale Medien
    TLC separation of potential antithyroid agents: N-aryl-N′-benzenesulphonylthiocarbamides (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 407-407 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Trenn. von Arylbenzolsulfonylthiocarbamiden ; Chromatographie, Dünnschicht
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00468534
    Standort Signatur Erwartet Verfügbarkeit
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  • 25
    Digitale Medien
    Digitale Medien
    Universelle, halogenfreie DC-Fließmittel für Arzneisubstanzen (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 398-401 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Analyse von pharmazeut. Produkten ; Chromatographie, Dünnschicht ; halogenfreie Fließmittelsysteme
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Mit 2 sauren, 2 basischen und einem neutralen Fließmittel mit unterschiedlichen Polaritäten und guten Trennleistungen konnten 151 von 157 geprüften Arzneisubstanzen mit hRf-Werten zwischen 10 und 90 chromatographiert werden.
    Notizen: Summary Using two acidic, two alkaline and a neutral mobile phase of different polarities and high separation efficiencies 151 of 157 tested drug substances could be chromatographed with hRf-values between 10 and 90.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00539712
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  • 26
    Digitale Medien
    Digitale Medien
    Zur Veränderung der Fluorescenzintensität polycyclischer Aromaten auf Dünnschichtplatten (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 24-29 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Best. von Polycyclen in Wasser ; Chromatographie, Dünnschicht ; Änderung der Fluorescenzintensität
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Nach der Verordnung über Trinkwasser und Brauchwasser für Lebensmittelbetriebe (Trinkwasserverordnung) vom 31. Januar 1975 müssen 6 Einzelverbindungen aus der Gruppe der polycyclischen aromatischen Kohlenwasserstoffe nachgewiesen werden. Das empfohlene Analysenverfahren basiert auf der Messung der Fluorescenz nach vorangegangener chromatographischer Trennung auf Adsorberschichten. Sowohl bei dieser Trennung als auch in der anschließenden Zeit verändert sich die Fluorescenzintensität einzelner Verbindungen z.T. beträchtlich. Systematische Untersuchungen an Kieselgel und an Mischschichten aus Aluminiumoxid und Acetylcellulose sollen die kritischen Punkte und die möglichen Fehlerquoten offen legen.
    Notizen: Summary According to the regulation on the use of drinking and industrial water in food industry (Drinking Water Regulation) of 31 January, 1975, six individual compounds of the group of polycyclic aromatic hydrocarbons must be traced. The analytical procedure recommended is based on the measurement of fluorescence after preceding Chromatographic separation on adsorber layers. In the course of this separation and during the time that follows, the fluorescence intensity of various compounds changes, in some cases considerably. Systematic studies with silica gel and mixed layers of aluminium oxide and acetyl cellulose are intended to reveal critical points and possible ranges of error.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00490944
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  • 27
    Digitale Medien
    Digitale Medien
    Zur Chromatographie von Metallchelaten (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 297 (1979), S. 138-143 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Trenn, der Metallchelate von 8-Mercaptochinolin ; Chromatographie, Dünnschicht
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung 8-Mercaptochinolin (Thiooxin) eignet sich zum Nachweis und zur Trennung von Metallen mit Hilfe der Dünnschicht-Chromatographie. Es bildet Neutralkomplexe definierter Zusammensetzung, die in wäßriger Phase schwerlöslich sind und in Chloroform extrahiert werden können. Fällung und Extraktion sind vom pH-Wert abhängig, wodurch eine Vortrennung der Metalle möglich ist. Beschrieben wird das dünnschicht-chromatographische Verhalten von 17 Metallchelaten. Die intensive Eigenfärbung der Komplexe erübrigt den Gebrauch von Anfärbereagentien. Die visuelle Nachweisgrenze der Metalle liegt zwischen 5 und 20 ng (Fluorescenzlöschung bei 254 nm). Spektralphotometrische Auswertung der Chromatogramme läßt eine Erniedrigung der Nachweisgrenze um etwa eine Zehnerpotenz erwarten.
    Notizen: Summary 8-Mercaptoquinoline (thiooxine) is qualified for the detection and separation of metals by thin-layer chromatography. It forms neutral complexes in definite composition, which are insoluble in aqueous solution, but readily soluble in CHCl3. Precipitation and extraction are dependent on the pH value, whereby pre-separation of metals is possible. The thin-layer chromatographic behaviour of 17 metal chelates is described. No spraying is necessary for detection, since the complexes show different, characteristic colours. The visual detection limits of the metals are between 5 and 20 ng (fluorescence quenching at 254 nm). Spectrophotometric determination of the chromatograms lowers the detection limit by one power of ten.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00483594
    Standort Signatur Erwartet Verfügbarkeit
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  • 28
    Digitale Medien
    Digitale Medien
    Zur Chromatographie von Metallchelaten (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 297 (1979), S. 144-147 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Trenn. der Metallchelate von 1-Hydroxy-2-pyridinthion ; Chromatographie, Dünnschicht
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung 1-Hydroxy-2-pyridinthion (HPT) bildet mit den Metallen der 8. Nebengruppe des Periodensystems intensiv gefärbte Chelatkomplexe. Führt man die Reaktion in wäßriger Phase bei pH 7 aus, so werden alle Elemente der Gruppe erfaßt und als schwerlösliche Neutralkomplexe gefällt. Diese lassen sich mit Chloroform extrahieren und dünnschichtchromatographisch trennen. Die Nachweisgrenze der Metalle liegt zwischen 3 und 40 ng (Fluorescenzlöschung bei 254 nm). Spektralphotometrische Auswertung der Chromatogramme läßt eine Erniedrigung der Nachweisgrenze um eine Zehnerpotenz erwarten.
    Notizen: Summary 1-Hydroxy-2-pyridinethione (HPT) forms highly coloured chelate complexes with the metals of the 8th sub-group. If the reaction is carried out in aqueous solution at pH 7, all elements of the group precipitate as insoluble neutral complexes. They can be extracted with CHCl3 and separated by thin-layer chromatography. The detection limit is between 3 and 40 ng (fluorescence quenching at 254 nm). Spectrophotometric determination of the chromatograms lowers the detection limit by one power of ten.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00483595
    Standort Signatur Erwartet Verfügbarkeit
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  • 29
    Digitale Medien
    Digitale Medien
    Rapid T.L.C. separation of some closely related potential antidiabetic guanylpyrazole nitrates (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 298 (1979), S. 44-44 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Trenn. von Guanylpyrazolnitraten ; Chromatographie, Dünnschicht
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00470050
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  • 30
    Digitale Medien
    Digitale Medien
    Synaptology of the central nervous system of the freshwater snail Lymnaea stagnalis (L.), with particular reference to neurosecretion (1979)
    Springer
    Cell & tissue research 198 (1979), S. 217-235 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Synaptic contacts ; Neurosecretion ; Lymnaea stagnalis ; Tilting stage electron microscopy ; Serial section reconstruction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In the central nervous system (CNS) of the freshwater snail Lymnaea stagnalis 3 types of interneuronal contacts can be distinguished electron-microscopically, viz. true synapses, “synapse-like structures” (SLS), and “spinules”. Use of the electron microscope specimen tilting stage reveals numerous true synapses. Both “terminal” and “en passant” contacts occur on neurones and on glial cells. Furthermore “bigeminal” synapses are present. Complex (combined) convergent and divergent synaptic arrangements are found. On the basis of the morphology of presynaptic vesicles 7 types of true synapses can be discerned. Histochemical data on the contents of the vesicles are lacking. However, vesicle morphology suggests that type IV is aminergic and type VII cholinergic. Terminal and en passant SLS may penetrate deeply into neuronal somata and large axons, and into glial cells. A cluster of synaptic vesicles is present in the presynapse-like element. Spinules (spine-coated “evagination-invagination” specializations of the plasma membranes of 2 adjacent neuronal elements) are observed between somata, between axons, and between soma and axon. The neurosecretory Light Green Cells (LGC) and Caudo-Dorsal Cells (CDC) receive complex synaptic input. Type V true synapses, 2 types of SLS, and spinules contact the LGC. The complex morphology of the relationship between type A SLS and LGC, studied in serial sections, reveals that adjacent glial cells are also contacted by type A SLS. Type II true synapses, 3 types of SLS, and spinules are identified on the CDC. The validity of the methods of identification and classification of interneuronal contacts in the CNS of L. stagnalis, as well as the role of these contacts in the regulation of the activity of “ordinary” neurones, neurosecretory cells, and glial cells is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00232006
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  • 31
    Digitale Medien
    Digitale Medien
    The hypothalamo-hypophysial system in the ground squirrel, Citellus erythrogenys Brandt (1979)
    Springer
    Cell & tissue research 198 (1979), S. 539-556 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Neurosecretion ; Ground squirrel (Citellus erythrogenys Brandt) ; Seasonal changes ; Hibernation ; Quantitative analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Monthly observations of the “Gomori-positive” hypothalamo-hypophysial neurosecretory system (HHNS) of the ground squirrel, Citellus erythrogenys Brandt, were carried out light microscopically using several quantitative methods. From the beginning of hibernation, formation of neurosecretory material (NSM) in the neurosecretory cells (NSC) progressively decreases and release of neurohormones from the HHNS is almost fully inhibited. A maximal accumulation of NSM in the perikarya of the NSC and in the posterior pituitary (PP) is found in December. By this time the volume of the cell nuclei and nucleoli is at a minimum. Signs of activation of the HHNS appear and become more conspicuous as the time of arousal from torpor approaches. The amount of NSM in the NSC and the PP decreases simultaneously with the increase in volume of the NSC. Hyperemia and activation of glial elements is visible throughout the HHNS. The morphological signs of activation reach their peak in March. After reproduction is completed (April to beginning of May), the NSC and the PP are almost devoid of NSM. Beginning with June and during the summer and autumn months a progressive accumulation of NSM in the NSC and the PP parallels gradual diminution in the volume of the NSC structures and the glial cells. Mechanisms and effector pathways by which the HHNS influences seasonal adaptation of the organism and reproduction are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00234197
    Standort Signatur Erwartet Verfügbarkeit
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  • 32
    Digitale Medien
    Digitale Medien
    Electron microscopic study of the giant cells in the olfactory bulb of labyrinth fish (Belontiidae, Perciformes) (1979)
    Springer
    Cell & tissue research 199 (1979), S. 509-517 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Olfactory bulb ; Giant cells ; Neurosecretion ; Electron microscopy ; Labyrinth fish
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The giant cells in the olfactory bulb of labyrinth fish, most likely belonging to the nervus terminalis, show ultrastructural features of active synthesis of secretory material. Dense core vesicles (70–100 nm in diameter), found in the perikaryon as well as in the axon, are the possible storage sites of the secretory substance. Its chemical nature is unknown. In some of these vesicles acid phosphatase is demonstrable. Large membrane-bound bodies (up to 2000 nm in diameter), either containing an electron dense matrix or debris of cytoplasmic organelles, are also acid phosphatase-positive, suggesting their lysosomal nature. Some other ultrastructural characteristics of these cells are also described.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00236086
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  • 33
    Digitale Medien
    Digitale Medien
    Diphenylamin im DC-Fließmittel als universelles Detektionsmittel (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 296 (1979), S. 45-45 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Chromatographie, Dünnschicht ; Diphenylamin als Detektionsmittel
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00481170
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  • 34
    Digitale Medien
    Digitale Medien
    Vollautomatische rechnergesteuerte Auswertung von Dünnschicht-Chromatogrammen (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 296 (1979), S. 369-373 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Chromatographie, Dünnschicht ; vollautomat. Auswertung von Chromatogrammen
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Es werden vollautomatische DC-Photometer beschrieben, bei denen ein Rechner die optimale Positionierung der DC-Flecke im Meßspalt steuert. Es lassen sich nicht nur die normalen Meßkurven, sondern auch die gemäß der Kubelka-Munk-Funktion transformierten Kurven für die Auswertung heranziehen. Infolge der Steuerung des Wellenlängenantriebes lassen sich auch Zweiwellenlängentechniken simulieren. Für die Auswertung eignet sich auch die 1. Ableitung der Meßkurve. Die Genauigkeit und Reproduzierbarkeit wird gesondert nach Auftragefehler, Meßfehler, Positionierfehler und Fehler der Chromatographie ausgewiesen.
    Notizen: Summary Automated photometers for evaluating TLC plates by an optimized positioning of the spots in respect to the centre of the light beam are described. The evaluation can be performed by using the original measuring curve or a transformed one in respect to the Kubelka-Munk function. Two-wavelength techniques can be simulated, for the monochromator is controlled by the computer. This method has an advantage in measuring not well separated spots. In this case also an evaluation of the first derivative is often successful. The accuracy and reproducibility is given in respect to the different sources of errors: spotting, measurement, positioning and chromatography.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00479975
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  • 35
    Digitale Medien
    Digitale Medien
    Ultrastructural development of the neurohemal organ joined to the ecdysial gland after imaginal moulting in the male isopod Sphaeroma serratum fab. (Crustacea Flabellifera) (1979)
    Springer
    Cell & tissue research 203 (1979), S. 403-414 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Neurohemal organ ; Neurosecretion ; Moulting gland ; Ultrastructure ; Crustaceans
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Beschreibung / Inhaltsverzeichnis: Résumé Chez Sphaeroma serratum, la mue de puberté est suivie d'une dégénérescence de l'organe Y (glands de mue). Le plexus nerveux céphalique latéral, organe neurohémal accolé à cette glande a été l'objet de la présente étude ultrastructurale. Cet organe représente un centre de stockage de neurosécrétions qui proviennent d'une part, de deux cellules autochtones (cellules plexales) situées au sein même de ce plexus, d'autre part, de cellules neurosécrétrices situées dans le “ganglion mandibulaire” (cellules de type A). Chez les individus pubères, les cellules plexales et les cellules A du ganglion sous-oesophagien synthétisent des granules de neurosécrétion dont la taille est respectivement 1550±50Å et 1570±40Å. Il a été reconnu au sein du plexus 5 catégories de terminaisons dont les granules proviendraient pour deux d'entre elles des cellules plexales et des cellules A du “ganglion mandibulaire”. Chez les animaux pubères on observe un arrêt de la synthèse des granules de neurosécrétion au sein des cellules plexales et des cellules A du “ganglion mandibulaire”. Simultanément on enregistre dans le plexus la raréfaction puis la disparition des divers types de granules. Ce processus atteint en premier les terminaisons correspondant aux cellules plexales et aux cellules A du “ganglion mandibulaire”. La dégénérescence de la glande de mue chez les mâles pourrait être en relation avec l'arrêt de synthèse de ces cellules.
    Notizen: Summary The present ultrastructural study deals with the lateral cephalic nerve plexus of Sphaeroma serratum, a neurohemal organ joined to the Y organ (ecdysial gland). This plexus acts as a storage centre for neurosecretory products from two sources: the two autochtonous cells (plexus cells) within the plexus itself, and the neurosecretory cells in various parts of the central nervous system, particulary the “mandibular ganglion” (A-cells). In prepuberal animals, plexus cells and subesophageal A-cells produce neurosecretory granules of two types measuring 1550±50Å and 1570±40Å respectively. Five categories of axon terminals were distinguished in the plexus. The granules found in two of these terminal types are believed to come from the plexus cells and from the “mandibular ganglion” A-cells. Cessation of production of neurosecretory granules in these A cells and plexus cells was observed in puberal animals, in the plexus with concomitant depletion and disappearance of different granule categories. The first axon terminals affected by this process are the two categories containing granules originating in the plexus and “mandibular ganglion” A-cells. Degeneration of the ecdysial gland in male Sphaeroma serratum might be connected with the cessation of granule formation in these two types of cell.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00233270
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  • 36
    Digitale Medien
    Digitale Medien
    Immunocytochemical identification of hyperglycemic hormone-producing cells in the eyestalk of Carcinus maenas (1979)
    Springer
    Cell & tissue research 204 (1979), S. 379-385 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Neurosecretion ; Immunofluorescence ; Crustacea ; X-organ ; Hyperglycemic Hormone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Antiserum raised in rabbits against extracts of sinus glands from Carcinus and shown by several criteria to contain antibodies directed against the neurosecretory hyperglycemic hormone was used to locate the hormone-producing perikarya in the optic ganglia. By means of the double antibody fluorescence technique, selective staining of the large neurosecretory perikarya of the medulla terminalis ganglionic X-organ (MTGXO) and their axons is obtained. The axon endings of the sinus gland are also stained. None of the other groups of neurosecretory cells in the eyestalk shows fluorescence. Preabsorption of the antiserum with pure hyperglycemic hormone abolishes the fluorescence.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00233650
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  • 37
    Digitale Medien
    Digitale Medien
    Ultrastructure of the corpus cardiacum and corpus allatum of the house cricket Acheta domesticus (1979)
    Springer
    Cell & tissue research 198 (1979), S. 201-208 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Neurosecretion ; Corpus cardiacum ; Corpus allatum ; Acheta domesticus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructure of the corpus cardiacum (CC) and corpus allatum (CA) of the house cricket, Acheta domesticus, is described. Axon profiles within the CC contain neurosecretory granules 160–350 nm in diameter which are indistinguishable from those found in type I neurosecretory cells of the pars intercerebralis and in the nervus corporis cardiaci I. The CC itself contains two cell types: intrinsic neurosecretory cells and glial cells. Intrinsic NSC cytoplasm contains Golgi bodies and electron dense neurosecretory granules 160–350 nm in diameter. Synaptoid configurations with 20–50 nm diameter electron lucent vesicles were observed within axon profiles of the CC. The structure of the CA is relatively uniform with one cell type predominating. Typical CA cells possess large nucleoli, active Golgi complexes, numerous mitochondria, and occassional microtubules. Groups of dark staining cells scattered throughout the CA of some animals were interpreted as evidence of cellular death.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00232004
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  • 38
    Digitale Medien
    Digitale Medien
    The neurosecretory hypothalamo-hindbrain pathway and its possible significance for the regulation of blood pressure and the milk-ejection reflex (1979)
    Springer
    Cell & tissue research 196 (1979), S. 321-336 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Neurosecretion ; Hypothalamo-hindbrain pathway ; Rat ; Blood pressure ; Milk ejection
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary 1. In lactating rats and in rats deprived of water, the amount of neurosecretory material in the fibres of the neurosecretory hypothalamohindbrain pathway exceeds that in untreated control animals. Under these experimental conditions the pathway and its target regions can be well analysed by means of fluorescence and electron microscopic methods. 2. The axons belonging to the hypothalamo-hindbrain pathway originate from perikarya located in the caudal portion of the nucleus paraventricularis and also from a small group of perikarya in the caudo-lateral hypothalamus. On the way to the hindbrain the neurosecretory fibres join other fibre bundles of the mid- and hindbrain. 3. In the hindbrain most of the neurosecretory fibres terminate in the area of the nucleus tractus solitarii and in the area of the dorsal column nuclei. The axon terminals form synapses with other neurones. 4. Using cytochemical methods at the ultrastructural level (Naumann and Sterba, 1976), the authors were able to prove that the vesicles in the exohypothalamic fibres and in their synaptic terminals contain the same sort of material as the neurophysin vesicles in the posterior lobe of the hypophysis. 5. The most distinct increase in neurophysin was observed in lactating females which were separated from their sucklings after a normal lactation period of 15 days and killed four days thereafter, and in rats deprived of water for different time periods. 6. The relationship of the neurosecretory hypothalamo-hindbrain pathway to the nucleus tractus solitarii and to the dorsal column nuclei suggests that, functionally, there may be a correlation between the system of blood-pressure control and the milk ejection reflex.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00240105
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  • 39
    Digitale Medien
    Digitale Medien
    Dünnschicht-chromatographische Trennung und Detektion von 14 1,4- bzw. 1,5-Benzodiazepin-Handelspräparaten und 17 Hauptmetaboliten (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 135-139 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Trenn. von Benzodiazepinen ; Chromatographie, Dünnschicht ; Metaboliten
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die DC-Trennung von 14 1,4- bzw. 1,5-Benzodiazepinen und 17 Hauptmetaboliten sowie die Detektion mit Bratton-Marshall-, Dragendorff- und Jodoplateat-Reagens werden beschrieben. Rf-Werte sowie die Reaktionen mit den Reagentien sind tabellarisch zusammengestellt und Biotransformationsschemata angegeben.
    Notizen: Summary Experimental details for the separation are described and data are compiled for Rf-values and reactions with Bratton-Marshall, Dragendorff and iodoplateate-reagents. Biotransformation schemes for the individual benzodiazepines are presented.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00523935
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  • 40
    Digitale Medien
    Digitale Medien
    Dünnschicht-chromatographischer Nachweis von IOXYNIL in biologischem Material (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 288-288 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Nachw. von Ioxynil in Biolog. Material ; Chromatographie, Dünnschicht
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00481657
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  • 41
    Digitale Medien
    Digitale Medien
    Alcohol separation by thin-layer chromatography. II (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 263-265 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Trenn. von Alkoholen ; Chromatographie, Dünnschicht ; C1-C20, 6 Trennsysteme, Dinitrobenzoate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Summary Thin-layer chromatography on rice starch, maize starch, cellulose and talc makes possible the separation of the homologous series of 3,5-dinitrobenzoates of aliphatic alcohols C1 to C20. Six different solvent systems have been employed. Dependence of R f-values on the number of C-atoms on various supports is discussed.
    Notizen: Zusammenfassung Mit Hilfe der Dünnschicht-Chromatographie auf Reisstärke, Maisstärke, Cellulose und Talk wurde die homologe Reihe der 3,5-Dinitrobenzoate von aliphatischen Alkoholen C1 bis C20 getrennt. Sechs verschiedene Fließmittel wurden benutzt. Die Abhängigkeit der R f-Werte von der Zahl der C-Atome auf verschiedene Schichten wird diskutiert.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00481489
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  • 42
    Digitale Medien
    Digitale Medien
    Rapid T.L.C. separation of some closely related potential antineoplastic arylazopyrazoles (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 272-272 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Trenn. von Arylazopyraolen ; Chromatographie, Dünnschicht
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00481495
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  • 43
    Digitale Medien
    Digitale Medien
    Trennung und Identifizierung von 12 antimikrobiellen Verbindungen mittels Dünnschicht-Chromatographie (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 36-41 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Trenn. von Antimikrobiellen Verbindungen ; Chromatographie, Dünnschicht
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die Trennung und Identifizierung von halogenierten, vorwiegend aliphatischen antimikrobiellen Verbindungen, von Formaldehyd abgebenden Substanzen und von Sulfonsäure-Derivaten auf dünnschicht-chromatographischem Wege wird beschrieben. Die Trennung erfolgt auf einer Kieselgel-Cellulose-Mischschicht mit Äthylacetat/Methanol/10% Ammoniak (65+30+5) als Laufmittel. Zur Sichtbarmachung und zur Identifizierung sind mehrere Sprühmittel notwendig: äthanolischeMethylgelb-Lösung mit anschließender UV-Bestrahlung, Phenylhydrazinsulfonat und Natronlauge sowie Hydroxylamin/Eisen(III)-chlorid und Nitroprussidnatrium-Kaliumhexacyanoferrat (III) u. a. Anhand der verschiedenen Rf-Werte und der Anfärbungen lassen sich die antimikrobiellen Verbindungen rasch und einfach identifizieren.
    Notizen: Summary The analysis of halogenated, mainly aliphatic compounds, of formaldehyde donors and of derivatives of sulphonic acid is described. The separation is carried out on plates coated with a mixed layer of silica gel and cellulose and a solvent mixture of ethylacetate/methanol/10% ammonia (65+30+5), whereas for the detection and identification several spray reagents have to be used: ethanolic solution of Methyl Yellow with subsequent UV irradiation, phenylhydrazine-4-sulphonic acid and sodium hydroxide, hydroxylamine/iron(III) chloride, sodium nitroprusside/potassium hexacyanoferrate(III) and others. The Rf-values and the colourations of the spots allow to identify the examined compounds rapidly and without further chemical procedures.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00694659
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  • 44
    Digitale Medien
    Digitale Medien
    TLC separation of some inorganic ions on DCTA impregnated thin-layer plates (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 42-42 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Trenn. von anorg. Ionen ; Chromatographie, Dünnschicht ; DCTA-imprägniert
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00694660
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  • 45
    Digitale Medien
    Digitale Medien
    Identification of some closely related potential antidiabetic 4-arylhydrazono-N′-benzylsulphonyl-3-methyl-2-pyrazoline-5-ones by TLC (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 414-414 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Identifizierung von Arylhydrazin-benzylsulfonylmethylpyrazolinonen ; Chromatographie, Dünnschicht
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00468541
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  • 46
    Digitale Medien
    Digitale Medien
    Separation and identification of closely related sulpha drugs by TLC on silica gel — calcium oxalate impregnated plates (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 299 (1979), S. 207-207 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Analyse von Sulfonamiden ; Chromatographie, Dünnschicht
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00581378
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  • 47
    Digitale Medien
    Digitale Medien
    Effects of measuring system parameters on the frequency dependence of strain-related potentials in bone (1979)
    Springer
    Medical & biological engineering & computing 17 (1979), S. 471-475 
    Details
    ISSN: 1741-0444
    Schlagwort(e): Bone ; Strain
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Abstract Specimens of dry human cortical bone of a disc form were subjected to sinusoidal loading under controlled conditions. The results show a nonlinear increase of the measured peak potential with frequency which reaches a limiting value at about 200 Hz. The analysis, which is based on the circuit representation proposed previously by Shamos, indicates that such a behaviour can be attributed to the measuring circuit parameters. It was found that some relevant results can be interpreted qualitatively by similar analysis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02447060
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  • 48
    Digitale Medien
    Digitale Medien
    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
    Schlagwort(e): Matrix vesicles ; Calcospherites ; Mineralization ; Bone ; Dentin ; Cartilage ; SEM
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02013233
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  • 49
    Digitale Medien
    Digitale Medien
    Mechanism of osteoclastic bone resorption: A new hypothesis (1978)
    Springer
    Calcified tissue international 26 (1978), S. 81-84 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Osteoclasts ; Bone ; Resorption
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02013238
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  • 50
    Digitale Medien
    Digitale Medien
    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
    Schlagwort(e): Plasma protein ; Glycoprotein ; Bone ; Glucosamine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02013251
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  • 51
    Digitale Medien
    Digitale Medien
    Effect of mithramycin on boneβ-glucuronidase and resorption (1978)
    Springer
    Calcified tissue international 26 (1978), S. 209-213 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Mithramycin ; Bone ; β-Glucuronidase ; KT medium
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02013260
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  • 52
    Digitale Medien
    Digitale Medien
    Radiogenic free radicals as molecular probes in bone (1978)
    Springer
    Calcified tissue international 25 (1978), S. 37-43 
    Details
    ISSN: 1432-0827
    Schlagwort(e): ESR ; Radiation free radicals ; CO3-Apatites ; Bone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02010749
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  • 53
    Digitale Medien
    Digitale Medien
    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
    Schlagwort(e): Parathyroid hormone ; Bone ; Calcium ; Chick embryo ; Organ culture
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02010774
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  • 54
    Digitale Medien
    Digitale Medien
    A bone resorbing substance from bovine serum albumin (brA) (1978)
    Springer
    Calcified tissue international 25 (1978), S. 233-240 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Bone ; Bone resorption ; Albumin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02010775
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  • 55
    Digitale Medien
    Digitale Medien
    Oestrogen binding proteins in bone cell cytosol (1978)
    Springer
    Calcified tissue international 25 (1978), S. 249-254 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Bone ; Oestrogens ; Oestrogen receptors ; Binding proteins
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02010778
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  • 56
    Digitale Medien
    Digitale Medien
    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 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Bone ; Histology ; Microradiography ; Densitometry ; Computer
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02013239
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  • 57
    Digitale Medien
    Digitale Medien
    Surface area of dental enamel, bone, and hydroxyapatite: Chemisorption from solution (1978)
    Springer
    Calcified tissue international 26 (1978), S. 139-142 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Chemisorption ; Surface area ; Hydroxyapatite ; Bone ; Enamel
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02013248
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  • 58
    Digitale Medien
    Digitale Medien
    Effect of sex steroids on bone collagen synthesis in vitro (1978)
    Springer
    Calcified tissue international 25 (1978), S. 105-110 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Progesterone ; 17β estradiol ; Testosterone ; Tissue culture ; Bone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02010758
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  • 59
    Digitale Medien
    Digitale Medien
    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 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Albumin ; Bone ; Growth retardation ; Osteomalacia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02010748
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  • 60
    Digitale Medien
    Digitale Medien
    Quantitative dünnschicht-chromatographische Bestimmung von aromatischen Aminen nach der Remissionsmethode (1978)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 292 (1978), S. 381-384 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Best. von Aminen, aromat. ; Chromatographie, Dünnschicht ; Remissionsmessung
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Es wird eine Methode zur quantitativen Bestimmung von aromatischen Aminen beschrieben. Diese werden dünnschicht-chromatographisch auf Kieselgel 60 F254 Fertigplatten in den Laufmitteln n-Propanol/Methanol/Wasser/Eisessig (65∶15∶15∶20; Vol.) oder n-Butanol/Wasser/Eisessig (66∶17∶17; Vol.) von den Begleitstoffen abgetrennt. Die getrennten Aminflecke werden entweder im Ultraviolett-Bereich oder nach Diazotierung im sichtbaren Bereich mit dem Chromatogramm-Spektralphotometer PMQ II nach der Remissionsmethode gemessen und anhand der auf derselben Platte aufgestellten Eichgerade ausgewertet. Die quantitative Bestimmung wird anhand der beiden Amine 5-Amino-2,4,6-trijod-isophthalsäurebis-(2,3-dihydroxy-propyl-N-methylamid) (I) und 2,4,6-Trijod-3-aminobenzoesäure (II) in Röntgenkontrastmittelpräparaten (RKP) demonstriert. Sowohl im UV- als auch im sichtbaren Bereich, läßt sich in 3000 μg RK-Säure (RKS) noch 0,1 μg freies aromatisches Amin, das sind 0,003%, bezogen auf die eingesetzte Menge RKS, mit einer maximalen relativen Standardabweichung von 4% bestimmen. Diese Methode ist spezifischer und empfindlicher als die der Diazotierung in Lösung.
    Notizen: Summary The aromatic amines are separated from impurities by thin-layer chromatography on silica gel 60 F254 precoated plates in the mobile solvents n-propanol/methanol/water/glacial acetic acid (65∶15∶15∶20; vol.) or n-butanol/water/glacial acetic acid (66∶17∶17; vol.). The separated amine spots are measured by the remission method by means of the TLC densitometer PMQ II, either in the u.v. region or, after diazotization, in the visible region, and evaluated on the basis of the linear calibration curve set up on the same plate. Quantitative determination is demonstrated by means of the two amines, 5-amino-2,4,6-triiodoisophthalic acid-bis-(2,3-dihydroxypropyl-N-methylamide) (I) and 2,4,6-triiodo-3-aminobenzoic acid (II), in radiopaque contrast media (RCM). Both in the u.v. and visible regions, it is still possible to determine 0.1 μg of free aromatic amine in 3000 μg of radiopaque contrast medium acid (RCA), or 0.003% in terms of the amount of RCA used, with a maximum relative standard deviation of 4%. This method is more specific and more sensitive than that of diazotization in solution.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00481557
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  • 61
    Digitale Medien
    Digitale Medien
    Analyse von Desodorantien in kosmetischen Präparaten (1978)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 293 (1978), S. 135-137 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Analyse von Desodorantien, Phenolderivaten in Kosmetika ; Chromatographie, Dünnschicht
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Phenolische Desodorantien in kosmetischen Präparaten lassen sich durch Umsetzung mit Echtrotsalz Al (Anthrachinondiazonium-chlorid-1) in wäßrig-alkalischer Lösung, Extraktion des gebildeten Azofarbstoffes mit einem organischen Lösungsmittel und anschließender Dünnschicht-Chromatographie schnell identifizieren. In den meisten Fällen ist die Abhängigkeit zwischen der Extinktion der Farbstofflösung und der eingesetzten Menge des betreffenden Desodorants linear, wodurch dann auch quantitative Bestimmungen möglich sind.
    Notizen: Summary Phenolic compounds, used as deodorants in cosmetic products can be identified quickly by reaction with anthraquinonediazonium chloride-1 (Echtrotsalz Al) in aqueous alkaline medium, extraction of the azo dye with an organic solvent and separation by thinlayer chromatography. The relation between the absorbance of the coloured solution and the concentration of the deodorant concerned is generally linear; in these cases quantitative determinations are always possible.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00486992
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  • 62
    Digitale Medien
    Digitale Medien
    Trennung und Nachweis von N-Heterocyclen auf CuSO4-imprägnierten Schichten (1978)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 291 (1978), S. 366-368 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Nachw. von N-Heterocycl. Verbindungen ; Chromatographie, Dünnschicht ; CuSO4-imprägnierte Schichten, Fluorescenz
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Durch die charakteristischen Fluorescenzfarben und die Fluorescenz-Thermochromie der CuJ-Komplexe lassen sich N-Heterocyclen auf Chromatogrammen meist einwandfrei identifizieren. Eine wesentliche Vereinfachung wird durch die Verwendung CuSO4-imprägnierter Kieselgelschichten erreicht. Die Nachweisempfindlichkeiten insbesondere bei tiefer Temperatur ändern sich im Vergleich zur ursprünglichen Technik kaum.
    Notizen: Summary N-Heterocycles can usually be identified with certainty through the characteristic fluorescence colours and fluorescence-thermochromism of the CuI-complexes. The use of CuSO4-impregnated silica gel layers facilitates the procedure considerably, and scarcely reduces the sensitivity of detection, particularly at low temperature.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00464970
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  • 63
    Digitale Medien
    Digitale Medien
    TLC separation of some inorganic ions on p-toluidine impregnated layers (1978)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 292 (1978), S. 415-416 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Trenn. von Anorgan. Ionen ; Chromatographie, Dünnschicht ; mit p-Toluidin imprägnierte Schichten
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00481570
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  • 64
    Digitale Medien
    Digitale Medien
    Scanning and transmission electron microscopy of the subfornical organ of the grass frog (Rana pipiens) (1978)
    Springer
    Cell & tissue research 186 (1978), S. 361-374 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Subfornical organ ; Circumventricular organs ; CSF-contacting neurons ; Encephalo-chromaffin cells ; Neurosecretion ; Rana pipiens
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ventricular surface of the subfornical organ of the frog is made up of ependymal cells with numerous apical microvilli, occasional cytoplasmic protrusions and many vacuoles projecting into the lumen of the third ventricle. Between these cells dendrites of cerebrospinal fluid-contacting neurons reach the ventricle to terminate in bulbous enlargements. In addition, flask-shaped encephalo-chromaffin cells, containing granulated vesicles and aggregates of filaments in their cytoplasm, project into the cerebrospinal fluid. Surrounding the centrally located capillaries are enlarged dendrites and axons of heterogeneous morphology, some of which appear to originate within the subfornical organ, intermingled with dendrites and axons of normal structure. The glial cells in this region, especially the microglial cells, often contain large lipofuscin inclusions, suggestive of degeneration and subsequent phagocytosis of some of the enlarged dendrites and axons. The normally scarce neurosecretory peptidergic axons become more evident and form typical Herring bodies in stalk-transected animals. Neuronal perikarya of varying morphology are predominantly located peripheral to the region of enlarged dendrites and axons. Supraependymal macrophages are particularly numerous on the subfornical organ.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00225544
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  • 65
    Digitale Medien
    Digitale Medien
    Distribution of fibres reacting with an α-endorphin antiserum in the neurohypophysis of Carassius auratus and Cyprinus carpio (1978)
    Springer
    Cell & tissue research 189 (1978), S. 251-256 
    Details
    ISSN: 1432-0878
    Schlagwort(e): α-Endorphin ; Neurosecretion ; Fish pituitary ; Hypothalamohypophyseal relationships ; Immunocytology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary A strong positive immunoreaction with an α-endorphin antiserum occurs in two distinct sites of the goldfish and carp neurohypophysis. Fluorescent nerve terminals are found in the laminar nerve processes located in the rostral pars distalis, but the immunocytological reaction is mainly localised on the nerve processes of the posterior neurohypophysis lying between the intermediate lobe cells. Almost all the digitations of the neurohypophysis are strongly fluorescent. The immunoreactive fibres probably originate from the hypothalamus, where perikarya displaying the same immunoreaction have been found in the pars lateralis of the nucleus lateralis tuberis and in some minor centres. The possibility that the immunoreactive substances revealed on the neurohypophyseal processes may originate in the intermediate lobe cells is also discussed. It has now to be established if this hypothalamo-hypophyseal system contains a substance with endorphic properties or only some immunologically related substance devoid of the corresponding physiological activities.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00209274
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  • 66
    Digitale Medien
    Digitale Medien
    Synaptic junctions in the sinus gland of the freshwater prawn Palaemon paucidens (1978)
    Springer
    Cell & tissue research 189 (1978), S. 435-440 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Neurosecretion ; Sinus gland ; Synapses ; Palaemon ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Two types of neurosecretory fibers, designated as Type 5 and Type 6 axons, in the sinus gland of the freshwater prawn, Palaemon, establish contact with other neurosecretory axons by means of synaptic junctions. This finding strongly supports the view that release of some neurohormones from the eyestalk may be regulated by neurosecretory neurons through synaptic transmission.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00209131
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  • 67
    Digitale Medien
    Digitale Medien
    The hypothalamo-hypophysial system in acipenseridae (1978)
    Springer
    Cell & tissue research 186 (1978), S. 559-570 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Nucleus praeopticus ; Neurosecretion ; Acipenseridae ; Quantitative study
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The peptidergic neurosecretory cells (NSC) of the nucleus praeopticus (NP) of male and female sturgeons, A. güldenstädti Brandt, were studied light microscopically at different stages of their life cycle and under experimental conditions. Four main NSC types reflecting different phases of secretory cycle and life course of the cell have been tentatively distinguished. The maximum percentage of the high and moderate active NSC are found in juvenile animals in the sea (stages I and I–II of gonadal maturity, sgm), in upstream migrating fish in spring before spawning, in down-stream migrating fish 1–1.5 months after spawning, and in experimental fish kept for 8.5 hours in a 32‰ sodium chloride solution. The least active NSC accumulating neurosecretory material (NSM) are characteristic of juvenile fish (sgm II) in the sea, sturgeons maintained in a sodium chloride solution for 3.5 or 6 hours and fish which remained in a net, thrown to the sea, for some hours before fixation. The lowest percentage of these cells is observed in autumn migrants, in females soon after spawning (sgm VI) and in fish kept for 8.5 hours in a sodium chloride solution. Cells rich in basophilic substance and poor in NSM occur in juvenile and in down-stream migrating fish. Cells reflecting the state of exhaustion after hyperactivity and “ageing” cells are seen in adults, especially in sgm VI fish, and in autumn migrants. Pyknomorphous NSC are constantly present in all fish; they are most numerous in sturgeons found in a net. A diagram demonstrating the life course and the secretory cycle of the NSC is presented and the role of the hypothalamo-hypophysial neurosecretory system (HHNS) under stress conditions is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00224944
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  • 68
    Digitale Medien
    Digitale Medien
    Immunofluorescence of somatostatin-producing sites in the hypothalamus of the tadpole, Alytes obstetricans Laur. (1978)
    Springer
    Cell & tissue research 187 (1978), S. 315-321 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Hypothalamus ; Tadpole, Alytes obstetricans ; Neurosecretion ; Somatostatin ; Immunofluorescence
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Three sites of somatostatin-synthesizing perikarya, or a related antigen, were determined by immunofluorescence in the hypothalamus of the tadpole, Alytes obstetricans (Amphibia, Anura). Two sites of neurosecretory perikarya were localized in the preoptic nuclei of the anterior hypothalamus; the axons extended either to the anterior diencephalon or to the median eminence and the pituitary. The third site was found in the posterior hypothalamus. These neurosecretory cells showed a strong immunofluorescent reaction; their axons all terminated at the level of the median eminence. Somatostatin cells were only found in intact or hypophysectomized tadpoles given somatotropin (STH). The strong reaction observed in hypophysectomized tadpoles was possibly due to the loss of the terminal portion of the neurosecretory pathway (median eminence and pituitary) by which the agent is transported to the site of discharge.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00224373
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  • 69
    Digitale Medien
    Digitale Medien
    The ultrastructure of the herring bodies in rats subjected to different experimental conditions (1978)
    Springer
    Cell & tissue research 189 (1978), S. 41-51 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Herring bodies (rat) ; Colchicine ; Cold ; Neurosecretion ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary A study of the morphology of Herring bodies of the posterior pituitary lobe of rats treated with colchicine and/or exposed to low temperatures has been performed. After treatment with colchicine (20 μg in distilled water injected intracisternally) a predominance of Herring bodies with a large number of small “synaptic-like” vesicles surrounded by neurosecretory granules is found. Exposures to low temperature (4–6° C) result in an increase in the neurosecretory material and the Herring bodies show many neurosecretory granules of different densities. After treatment with colchicine and subsequent exposure to low temperatures, the Herring bodies are characterized by having a great number of autophagic bodies which become more numerous as the length of the exposure is increased; later autophagic vacuoles and lamellar bodies become evident.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00223120
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  • 70
    Digitale Medien
    Digitale Medien
    Structural re-evaluation of the neurosecretory system in the crayfish eyestalk (1978)
    Springer
    Cell & tissue research 190 (1978), S. 235-246 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Neurosecretion ; Cobalt backfilling ; Crustacea ; Sinus gland ; X organ
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The topography of the neurosecretory system in the decapod eyestalk has not been precisely delineated with light microscopy. Cobalt iontophoresis and electron microscopy have proved useful in clarifying the microstructure of this system. The sinus gland (sg) of the crayfish eyestalk consists of aggregated axon terminals which end at or near the blood space, lontophoresing cobalt back through the cut base of the sinus glands reveals proximal cell bodies in the eyestalk only in the X organ (Xo) region. Electron microscopy demonstrates that axons from about 115 neurosecretory cell bodies in the Xo form the Xo-sg tract. Intermingled with these Xo somata are smaller non-neurosecretory cell bodies which do not send axons into the sinus gland. One of these exhibits catecholamine fluorescence. Backfilling also reveals a second group of fibres which run from the brain along the optic tract and into the sinus gland. These brain-sg fibres are smaller in diameter than Xo-sg axons and lack neurosecretory vesicles. From these fibres collaterals extend into the eyestalk neuropil, especially in the proximity of the visual elements. The possible function of these non-neurosecretory processes within the sinus gland is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00218172
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  • 71
    Digitale Medien
    Digitale Medien
    Fine structural and cytochemical study of the innervation of smooth muscle in an amphibian (Bufo marinus) lung before and after denervation (1978)
    Springer
    Cell & tissue research 194 (1978), S. 419-432 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Lung ; Bufo marinus ; Innervation ; Adrenergic nerves ; Neurosecretion
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The innervation of the toad (Bufo marinus) lung was studied with transmission electron microscopy and fluorescence techniques, both before and after 12 or 20 days close vagosympathetic denervation. Four cytologically distinct types of neuronal processes were recognised, in relation to the visceral muscles of the lung. These were described as cholinergic, adrenergic, nonadrenergic/non-cholinergic (NANC) and sensory on the basis of the characteristics of their vesicular content and cytochemical reactions. An apparent efferent innervation of visceral smooth muscle was achieved by NANC (50%), cholinergic (25%) and adrenergic (25%) fibres. A few sensory fibres were also present. After denervation only NANC fibres persisted, showing that the cell bodies of these fibres were intrapulmonary. The vascular smooth muscle was supplied by cholinergic, adrenergic and sensory fibres. In the walls of the proximal branches of the pulmonary artery were fibres containing large dense-cored vesicles. These profiles, which were associated with the vasa vasorum, were similar to neurosecretory fibres. After denervation all neural profiles associated with the vasculature had degenerated. The observations suggest that vagal vasodepressor effects in the toad lung are mediated indirectly through relaxation of visceral muscle strands which in their contracted state compress vascular channels.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00236163
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  • 72
    Digitale Medien
    Digitale Medien
    A simple procedure for the chromatographic isolation and determination of prostaglandins from human seminal plasma (1978)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 293 (1978), S. 45-48 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Best. von Prostaglandinen in Sperma ; Chromatographie, Dünnschicht
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Summary A relatively simple procedure for the isolation and determination of the prostaglandins present in human seminal fluid is described. It involves preliminary chromatographic purification of these compounds from the major non-prostaglandin impurities followed by their total elution in one solvent (one-step elution). The prostaglandins thus obtained were almost free from other lipids and were further resolved into prostaglandin-groups and individual prostaglandins by repeated thin-layer chromatography. Data are also presented for prostaglandin contents of fresh semen samples from five individuals and results compared with those from the stored samples.
    Notizen: Zusammenfassung Das Verfahren umfaßt eine chromatographische Abtrennung der Verbindungen von den hauptsächlichsten Verunreinigungen und die Gesamtelution mit einem Lösungsmittel. Die von anderen Lipiden fast völlig freien Prostaglandine werden durch wiederholte Dünnschicht-Chromatographie in Gruppen und Einzelverbindungen getrennt. Werte werden angegeben über die Prostaglandingehalte von frischem im Vergleich zu gelagertem Sperma.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00482001
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  • 73
    Digitale Medien
    Digitale Medien
    Trennung und Identifizierung von Inhaltsstoffen der HCH-Salbe „Antiskabiosum“ an Fertigfolien für die Dünnschicht-Chromatographie (Reinheitsprüfung) (1978)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 292 (1978), S. 237-237 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Analyse von HCH-Salbe ; Chromatographie, Dünnschicht ; Fertigfolien
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00491816
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  • 74
    Digitale Medien
    Digitale Medien
    T.L.C. separation of some closely related potential antidiabetic 3,5-dimethyl-4-arylazoisoxazoles (1978)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 292 (1978), S. 238-238 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Trenn. von Dimethylarylazoisoxazolen ; Chromatographie, Dünnschicht
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00491817
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  • 75
    Digitale Medien
    Digitale Medien
    Untersuchung der Biotransformation von Pemolin im menschlichen Organismus (1978)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 289 (1978), S. 110-111 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Identifizierung von Pemolin-Metaboliten im Harn ; Chromatographie, Dünnschicht ; UV-, IR-, Massenspektren
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00443957
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  • 76
    Digitale Medien
    Digitale Medien
    Bestimmung von Trimethylzinnverbindungen in Dimethylzinn-di(thioglykolsäureisooctylester) (1978)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 289 (1978), S. 285-286 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Best. von Trimethylzinnverbindungen in Dimethylzinn-di(thioglykolsäureisooctylester) ; Chromatographie, Dünnschicht
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00440214
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  • 77
    Digitale Medien
    Digitale Medien
    TLC separation of some inorganic ions (1978)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 290 (1978), S. 46-46 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Trenn. von Ionen, anorgan ; Chromatographie, Dünnschicht
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00468863
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  • 78
    Digitale Medien
    Digitale Medien
    Separation of rhodium and iridium by anion-exchange thin-layer chromatography (1978)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 290 (1978), S. 46-47 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Trenn. von Rhodium und Iridium ; Chromatographie, Dünnschicht ; Anionenaustausch
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00468864
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  • 79
    Digitale Medien
    Digitale Medien
    TLC-separation of potential antineoplastic agents: Ethyl-2, 3-dioxobutyrate-2-arylhydrazones (1978)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 290 (1978), S. 48-48 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Trenn. von Äthyl-2,3-dioxobutyrat-2-arylhydrazonen ; Chromatographie, Dünnschicht ; Antineoplastica
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00468866
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  • 80
    Digitale Medien
    Digitale Medien
    Automatische Fluorimetrie von Mikro-Dünnschicht-Chromatogrammen (1978)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 290 (1978), S. 133-134 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Analyse von Aminosäuren ; Chromatographie, Dünnschicht ; automat. F luorimetrie
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00482294
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  • 81
    Digitale Medien
    Digitale Medien
    Identification of a new metabolite of digitoxin by radio-thin-layer-chromatography (1978)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 290 (1978), S. 157-157 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Nachw. von Digitoxinmetaboliten in Harn ; Chromatographie, Dünnschicht ; Radio
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00482314
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  • 82
    Digitale Medien
    Digitale Medien
    Semiquantitative estimation of the mycotoxins citrinin, Ochratoxin A, Aflatoxin M1 and penicillic acid on thin-layer chromatograms with a grey scale (1978)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 293 (1978), S. 138-140 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Best. von Mycotoxinen, Citrinin, Ochratoxin A, Aflatoxin M1, Penicillinsäure ; Chromatographie, Dünnschicht ; Graukeil
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Summary Spots of citrinin, ochratoxin A, aflatoxin M1 and penicillic acid on thin-layer chromatograms can be semi-quantitatively estimated by using a grey scale, commonly used in photo laboratories. The detection limits are 0.01 μg for citrinin, 0.006 μg for ochratoxin A, 0.002 μg for aflatoxin M1 and 0.01 μg for penicillic acid. Standard curves for these mycotoxins are given.
    Notizen: Zusammenfassung Mit Hilfe eines in Photolabors gebräuchlichen Graukeils können dünnschicht-chromatographische Flecke der obengenannten Mycotoxine halbquantitativ bestimmt werden. Die Nachweisgrenzen betragen 0,01 μg für Citrinin, 0,006 μg für Ochratoxin A, 0,002 μg für Aflatoxin M1 und 0,01 μg für Penicillinsäure. Eichkurven werden angegeben.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00486993
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  • 83
    Digitale Medien
    Digitale Medien
    TLC separation of closely related aromatic amines II (1978)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 291 (1978), S. 221-221 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Trenn. von Aminen, aromat. ; Chromatographie, Dünnschicht
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00480695
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  • 84
    Digitale Medien
    Digitale Medien
    Identification of some 2[2-mercapto (or substituted mercapto)-4-thiazolyl] benzothiazoles by thin-layer chromatography (1978)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 291 (1978), S. 224-224 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Nachw. von Mercaptothiazolyl-benzothiazolen ; Chromatographie, Dünnschicht
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00480698
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  • 85
    Digitale Medien
    Digitale Medien
    Untersuchungen zur quantitativen Bestimmung der Seltenen Erden nach dünnschicht-chromatographischer Trennung mit bekannten und neuen Laufmittelsystemen (1978)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 291 (1978), S. 328-331 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Trenn. von Seltenen Erden von Uran ; Photometrie ; Chromatographie, Dünnschicht ; Diäthyläther/Tetrahydrofuran/Bis-(2-äthylhexylphosphat)/HNO3
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Mit dem Laufmittel Diäthyläther/Bis-(2-äthylhexylphosphat) (HDEHP)/Salpetersäure (100∶1∶3,5) können alle Seltenen Erden (S.E.) dünnschicht-chromatographisch (DC-Trennung) getrennt werden. Durch Variation von HDEHP und HNO3 ist es möglich, entweder die Rf-Werte der schweren oder leichten S.E. auseinander zu ziehen. Eine weitere DC-Trennung der S.E. gelingt mit dem Laufmittel Diäthyläther/Tetrahydrofuran/HDEHP/ HNO3. Nach der DC-Trennung werden die einzelnen S.E. auf zwei Wegen quantitativ bestimmt: a) Durch Auswertung der Fleckengröße, b) photometrisch nach Abkratzen der Flecken mit Neothorin. Als Analysen-Beispiel wird die Bestimmung von S.E. im ppm-Bereich in Spilitischem Schalstein gezeigt. Die relativen Standardabweichungen sind befriedigend.
    Notizen: Summary All rare earths can be separated by TLC with the eluent diethyl ether/bis-(2-ethylhexylphosphate) (HDEHP)/nitric acid (100∶1∶3.5). It is possible to increase the R f-differences between either the heavy or the light rare earths by variation of HDEHP and HNO3. A further separation can be obtained by using diethyl ether/THF/HDEHP/HNO3 as an eluent. After TLC separation the rare earths can be determined quantitatively in two ways: (a) by evaluation of spot area, (b) by photometry with Neothorin as indicator after scraping the spots. The determination of rare earths in the ppm range in spilites is shown as an example. The relative standard deviations are satisfactory.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00491950
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  • 86
    Digitale Medien
    Digitale Medien
    Radiochemical assay of prostaglandins, thromboxane, prostaglandin endoperoxides, 12-hydroxyeicosatetraenoic acid (HETE) and 12-hydroxyheptadecatrienoic acid (HHT) formed by human platelets from arachidonic acid (1978)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 292 (1978), S. 228-232 
    Details
    ISSN: 1618-2650
    Schlagwort(e): Analyse von Prostaglandinen, Thromboxan, Prostaglandinendoperoxiden, 12-Hydroxyeicosantetraensäure, 12-Hydroxyheptadecatriensäure aus Thrombocyten ; Chromatographie, Dünnschicht ; gebildet aus Arachidonsäure, radiochemisch
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Summary A three-step thin-layer chromatographic procedure is described for the isolation and measurement of the various compounds formed by human platelets from radioactive arachidonic acid. The data presented show that other unknown compounds may also be formed in substantial amounts. The method can be used on a routine basis by combining a two-dimensional thin-layer chromatographic separation with an additional TLC for a complete resolution of the prostaglandins and other products.
    Notizen: Zusammenfassung Ein dreistufiges TLC-Verfahren wird beschrieben zur Trennung und Bestimmung der verschiedenen Verbindungen, die durch Thrombocyten aus radioaktiver Arachidonsäure gebildet werden. Die vorliegenden Ergebnisse zeigen, daß außer den oben genannten noch weitere unbekannte Verbindungen in wesentlichen Mengen gebildet werden können. Durch Kombination einer dreidimensionalen TLC mit einer weiteren TLC-Trennung kann eine vollständige, routinemäßige Analyse der Prostaglandine und anderen Verbindungen durchgeführt werden.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00491813
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  • 87
    Digitale Medien
    Digitale Medien
    Isolation of osteoclasts by velocity sedimentation at unit gravity (1977)
    Springer
    Calcified tissue international 22 (1977), S. 303-313 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Osteoclasts ; Sedimentation ; Isolation ; Cells ; Bone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02010369
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  • 88
    Digitale Medien
    Digitale Medien
    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
    Schlagwort(e): Bone ; Diphosphonates ; Bone resorption ; Bone formation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02012787
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  • 89
    Digitale Medien
    Digitale Medien
    Quantitative analyses of osteoclast changes in resorbing bone organ cultures (1977)
    Springer
    Calcified tissue international 23 (1977), S. 283-289 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Bone ; Resorption ; Osteoclast ; Quantitation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02012798
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  • 90
    Digitale Medien
    Digitale Medien
    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
    Schlagwort(e): Albumin ; Bone ; Hydroxyapatite ; Plasma protein
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02012801
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  • 91
    Digitale Medien
    Digitale Medien
    Cortical bone remodeling in normal rat (1977)
    Springer
    Calcified tissue international 23 (1977), S. 161-170 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Bone ; Growth ; Rat ; Remodeling ; Tetracyclines
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02012782
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  • 92
    Digitale Medien
    Digitale Medien
    Bone water (1977)
    Springer
    Calcified tissue international 23 (1977), S. 1-5 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Water ; Bone ; Homeostasis ; Structure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02012759
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  • 93
    Digitale Medien
    Digitale Medien
    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
    Schlagwort(e): Lead salt ; Bone ; Mobilization ; Hypercalcemia ; Hyperphosphatemia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02223295
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  • 94
    Digitale Medien
    Digitale Medien
    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
    Schlagwort(e): Parathyroid hormone ; Plasma calcium ; Radiocalcium ; Bone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02223318
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  • 95
    Digitale Medien
    Digitale Medien
    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
    Schlagwort(e): Matrix vesicles ; Bone ; Ultracrytomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02012785
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  • 96
    Digitale Medien
    Digitale Medien
    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
    Schlagwort(e): Magnesium ; Bone ; Mineral ; Chick embryo ; Organ culture
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02223301
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  • 97
    Digitale Medien
    Digitale Medien
    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
    Schlagwort(e): Bone ; Fluoride ; Calcium ; Phosphorus ; Mechanical Strength
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02010341
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  • 98
    Digitale Medien
    Digitale Medien
    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
    Schlagwort(e): Parathyroid hormone ; Plasma calcium ; Radiocalcium ; Bone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02010351
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  • 99
    Digitale Medien
    Digitale Medien
    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
    Schlagwort(e): Bone ; Calcium ; Collagen ; Dentine ; Phosphoprotein
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02010366
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  • 100
    Digitale Medien
    Digitale Medien
    Strain related electrical potentials recorded in vitro and in vivo (1977)
    Springer
    Calcified tissue international 22 (1977), S. 315-327 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Bone ; Bioelectricity ; Strain ; Locomotion ; Osteoporosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02010370
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