ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Bone  (222)
  • Chromatographie, Dünnschicht  (138)
  • Drosophila  (97)
  • Neurosecretion  (85)
  • Springer  (542)
  • American Geophysical Union
  • Irkutsk : Ross. Akad. Nauk, Sibirskoe Otd., Inst. Zemnoj Kory
  • Krefeld : Geologischer Dienst Nordhein-Westfalen
  • Wiley
  • 2015-2019
  • 1975-1979  (279)
  • 1970-1974  (263)
Collection
Keywords
Publisher
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    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
    Keywords: Calcification ; Bone ; Glycoprotein ; Golgi ; Osteoblasts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441182
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Bone fluoride concentrations associated with fluoridated drinking water (1979)
    Springer
    Calcified tissue international 27 (1979), S. 95-99 
    Details
    ISSN: 1432-0827
    Keywords: Bone ; Fluoride ; Analysis ; Food ; Age
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441168
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Use of a spectrophotometer for radiographic photodensitometry of bone (1979)
    Springer
    Calcified tissue international 28 (1979), S. 103-105 
    Details
    ISSN: 1432-0827
    Keywords: Bone ; Photodensitometry, X-ray ; Radiography ; Spectrophotometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441227
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    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
    Keywords: ESR ; Bone ; Enamel ; CO3-Apatite ; Paramagnetism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441228
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    On the solid state of bone (1979)
    Springer
    Calcified tissue international 28 (1979), S. 33-36 
    Details
    ISSN: 1432-0827
    Keywords: Infrared, visible light ; Bone ; Collagen ; Apatite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441215
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Intercellular junctions during development and in tissue cultures ofDrosophila melanogaster: An electron-microscopic study (1979)
    Springer
    Development genes and evolution 186 (1979), S. 333-349 
    Details
    ISSN: 1432-041X
    Keywords: Imaginal disks ; Intercellular junctions ; Determination ; Pattern formation ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The present investigation analyzes intercellular junctions in tissues with different developmental capacities. The distribution of junctions was studied inDrosophila embryos, in imaginal disks, and in cultures of disk cells that were no longer able to differentiate any specific pattern of the adult epidermis. The first junctions —primitive desmosomes andclose membrane appositions — already appear in blastoderm.Gap junctions are first detected in early gastrulae and later become more and more frequent.Zonulae adhaerentes are formed around 6 h after fertilization, whileseptate junctions appear in the ectoderm of 10-h-old embryos. Inwing disks of all stages studied (22–120 h), three types of junctions are found: zonulae adhaereentes, gap junctions, and septate junctions. Gap junctions, which are rare and small at 22 h, increase in number and size during larval development. The other types of junctions are found between all cells of a wing disk throughout development. All types of junctions that are found in normal wing disks are also present in theimaginal disk tissues cultured in vivo for some 15 years and in thevesicles of imaginal disk cells grown in embryonic primary cultures in vitro. However, gap junctions are smaller and in the vesicles less frequent than in wing disks of mature larvae. Thus gap junctions, which allow small molecules to pass between the cells they connect, are present in the early embryo, when the first developmental decisions take place, and in all imaginal disk tissues studied, irrespective of whether or not these are capable of forming normal patterns.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848457
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    A high-resolution morphogenetic map of the second-leg basitarsus inDrosophila melanogaster (1979)
    Springer
    Development genes and evolution 187 (1979), S. 129-150 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Pattern formation ; Leg ; Bristle ; Cell lineage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The lineages of cells on the second-leg basitarsus ofDrosophila melanogaster were analyzed by examining gynandromorphs andMinute mosaics. Bracts lie proximal to bristles on the adult basitarsus, yet bract precursor cells were found to originate lateral to bristle precursor cells. In 6 of the 8 longitudinal rows of bristles on this segment, the bract cells arise ventral to the bristle cells; in the others they arise dorsally. The lateral cell origins are interpreted as reflecting a pattern of lateral cell movements associated with evagination of the leg disc. An unusual discrepancy was observed in the relative frequencies of male vs. female bracts and bristles in gynandromorphs. The discrepancy suggests that there is a cell-autonomous sexual difference in either the time at which cells begin moving during evagination or the speed with which they move. On the basis of the results, it is reasoned that the bristle pattern of the basitarsus does not originate in its final form. Prior to evagination, the bristle cells of each row are apparently closer together than in the final pattern, and the rows are farther apart. Evidence is presented which suggests that the bristle cells of each row may originally be arranged in a jagged line which is later straightened by cell movements. The two locations where the anterior/posterior compartment boundary of the second leg passes through the basitarsus were found to vary relative to the bristle pattern. If this boundary is assumed to be a fixed line of positional values, then the extent of the observed variability — which is estimated to be ± 1 or 2 cell diameters — provides a measure of the precision of patterning around the circumference.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848267
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Differentiation capacities of the labial imaginal disc ofDrosophila melanogaster (1979)
    Springer
    Development genes and evolution 186 (1979), S. 51-64 
    Details
    ISSN: 1432-041X
    Keywords: Imaginal discs ; Labial disc ; Fate map ; Drosophila ; Homoeosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The mature labial disc, when implanted into a larva of the same age, undergoes metamorphosis along with the host and produces one lateral half of the medi- and distiproboscis. On the basis of results obtained from transplanted disc halves (including the separate peripodial membrane) a tentative fate map of the labial disc was constructed, which shows most of the presumptive mediproboscis to be located in the dorsal, and most of the presumptive distiproboscis in the ventral part of the disc. The distal protion of the peripodial membrane also contains imaginal anlagen, viz. part of the mediproboscis, prementum, and labellar cap anlagen. The involvement of this part of the peripodial membrane was checked by a careful histological analysis of labial disc development during the first ten hours after prepupation. The results were compared with the situation described forCalliphora imaginal discs. In addition, a detailed morphological analysis was made of the proboscis of the homoeotic mutantproboscipedia (pb). At 27°C,pb changes the distiproboscis into a “telopodite” (leg segments distal to the coxa); the (unchanged) prementum may therefore correspond to the coxa. At 15° C, the tarsus of this homoeotic “telopodite” is replaced to a greater or lesser extent by an arista. The present analysis thus confirms (a) the fundamental morphological correspondence of the medi- and distiproboscis with the labium of other insects, and (b) the fundamental developmental correspondence of the labial, antennal, and leg discs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848107
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Temperature sensitivity ofTumorous head, a homoeotic mutant ofDrosophila melanogaster (1979)
    Springer
    Development genes and evolution 186 (1979), S. 87-90 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Homoeotic mutant ; Determination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A temperature-sensitive period during early embryogenesis for three stocks carrying thetuh-3 gene suggests that it is a homoeotic mutation involved in the initial determination of the eye-antennal disc rather in maintenance of the determination.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848112
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Regulation and metamorphosis of the abdominal histoblasts ofDrosophila melanogaster (1979)
    Springer
    Development genes and evolution 186 (1979), S. 235-265 
    Details
    ISSN: 1432-041X
    Keywords: Regulation ; Histoblasts ; Drosophila ; Microcautery
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The development of the adult abdomen ofDrosophila melanogaster was analyzed by histology, microcautery, and genetic strategies. Eight nests of diploid histoblasts were identified in the newly hatched larva among the polytene epidermal cells of each abdominal segment: pairs of anterior dorsal, posterior dorsal, and ventral histoblast nests and a pair of spiracular anlagen. The histoblasts do not divide during larval life but begin dividing rapidly 3 h after pupariation, doubling every 3.6 h. Initially they remain confined to their original area, but 15 h after pupariation the nests enlarge, and histoblasts replace adjacent epidermis cell by cell. The histoblasts cover half the abdomen by 28 h after pupariation and the rest by 36 h. Polytene epidermal cells of the intersegmental margin are replaced last. Cautery of the anterior dorsal nest caused deletion of the whole corresponding hemitergite, whereas cautery of the posterior dorsal nest caused the deletion of the macrochaetae of the posterior of the hemitergite. Cautery of the ventral nest deleted the hemisternite and the pleura, whereas cautery of the spiracular anlagen deleted the spiracle. Results of cautery also revealed that no macrochaetae formed on the tergite in the absence of adjacent microchaetae. Clonal analysis revealed that there were no clonal restrictions within a hemitergite at pupariation. Cautery of polytene epidermal cells other than those of the intersegmental margin failed to affect tergite development. However, cautery of polytene epidermal cells of the intersegmental margin adjacent to either dorsal histoblast nest caused mirror-image duplications of the anterior or posterior of the hemitergite in 10% of the hemitergites. Forty percent of the damaged presumptive hemitergites formed complete hemitergites, indicating extensive pattern regulation and regeneration. Pattern duplication and regeneration were accounted for in terms of intercalation and a model of epimorphic pattern regulation (French et al., 1976). Histoblasts in adjacent segments normally develop independently, but if they are enabled to interact by deleting the polytene epidermal cells of the intersegmental margin, they undergo intercalation which results in duplication or regeneration. The possible role of the intersegmental margin cells of insects in development was analyzed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848591
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    cell clones and pattern formation: Studies onsevenless, a mutant ofDrosophila melanogaster (1979)
    Springer
    Development genes and evolution 186 (1979), S. 27-50 
    Details
    ISSN: 1432-041X
    Keywords: Compound eye ; Development ; Determination of R7 cells ; sevenless mutant analysis ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary sev LY3,the only existing allele at thesev locus (1–33,2±0,2), behaves as strongly hypomorph or even as amorph. Ommatidia in asev compound eye have only seven receptor cells, the position of the R7 pattern element being vacant. Various criteria showing that the missing cell is R7 have been verified. These include (i) anatomical characteristics ofsev ommatidia; (ii) behaviour of central R cells insev rdgB double mutants; (iii) medullary projection of central R cell axons; and (iv) mitotic pattern ofsev imaginal discs. The analysis of morphogeneticsev-sev + mosaics has shown thatsev is expressed autonomously by R7 cells, indicating that thesev phenotype is not due to asev genotype of ommatidial pattern elements other than R7. The study of third instarsev imaginal discs has not brought any direct evidence for death of clustered presumptive R7 cells; however, clonal analysis of the developingsev compound eye has given evidence of developmental parameters comparable to those ofsev +, therefore favouring the hypothesis that R7 cells die insev mutants. On the other hand,sev + seems to be required for the determination of the R7 cells, since thesev phenotype cannot be uncovered during the last mitoses of heterozygous mutant cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848106
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Regulative interaction of mature imaginal disc Fragments with embryonic and immature disc tissues inDrosophila (1979)
    Springer
    Development genes and evolution 187 (1979), S. 1-11 
    Details
    ISSN: 1432-041X
    Keywords: Imaginal discs ; Drosophila ; Pattern regulation embryos
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary These experiments examined whether inDrosophila immature imaginal disc tissue and tissues from embryonic stages can influence pattern regulation in a disc fragment in the same way as can mature imaginal discs. Immature imaginal discs, or the cells of whole embryos, were mixed with a test fragment (presumptive notum) from a mature wing disc. The immature tissues in each mixture were genetically marked and had been heavily irradiated (25 Kr gamma) prior to mixing to prevent growth and maturation during subsequent culture in vivo. Alteration of the regulative behavior of the test fragment (that is, regeneration of wing) thus provided an assay for the communication of positional information by the immature tissues. The results suggest that this capacity arises well before competence to metamorphose, as early as the 16th hour of embryonic development, whereas prior to 16 h, essentially no stimulation of regeneration occurred. It is suggested that the imaginal disc (or presumptive disc) cells of the embryo may have been responsible for this early stimulatory capacity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848162
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    A comparative study of embryonic gene expression inDrosophila andEphestia (1979)
    Springer
    Development genes and evolution 187 (1979), S. 81-88 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Ephestia ; Allozymes ; Gene activation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ontogeny of allozyme patterns has been studied in embryos ofDrosophilamelanogaster, which are doubly heterozygous for alleles specifying the slow and fast forms of alcohol dehydrogenase (ADH) and α-glycerophosphate dehydrogenase (GPDH). The ontogeny of esterase-2 was studied in embryos and young larvae of the flour mothEphestia kühniella, which are heterozygous for two of the three existing esterase-2 alleles. In freshly laidDrosophila eggs only the maternal enzyme forms are present and during the first 15 hours of development the staining of these forms becomes progressively fainter. After 16 and 17 h, the paternal and hybrid bands of ADH and GPDH respectively become obvious. Before hatching, the intensity distribution in the three-banded pattern of reciprocal hybrids is asymmetric in favour of the persisting maternal enzyme form. InEphestia embryos, however, there is no persistence of the maternal esterases. In all reciprocal heterozygotes a three-banded pattern suddenly appears 96 h after egg deposition, indicating synchronous activation of both parental alleles. The relative intensity distribution in the hybrid patterns approaches that of the mature larvae stepwise and in an allele-specific manner. This result and the fact that the various heterozygous types exhibit unequal total activities suggest that the Esterase-2 alleles have different activities, which are fixed late in embryogenesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848169
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    In vitro development of theDrosophila chorion in a chemically defined organ culture medium (1979)
    Springer
    Development genes and evolution 186 (1979), S. 351-362 
    Details
    ISSN: 1432-041X
    Keywords: Eggshell ; Chorion ; In vitro development ; Drosophila ; Tissue culture media
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary TheDrosophila chorion is produced normally in isolated follicles in Robb's chemically defined culture medium. The complex architecture of the shell developed in vitro from follicles as young as early stage 10 is completely normal morphologically. In addition, the time required for in vitro development closely approximates that observed for in vivo development. Comparisons of insect culture media developed by Robb, Grace, Schneider, and Echalier show large variations in their ability to supportDrosophila chorion development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848458
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Pattern as a function of cell number and cell size on the second-leg basitarsus ofDrosophila (1979)
    Springer
    Development genes and evolution 187 (1979), S. 105-127 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Pattern formation ; Leg ; Bristle ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The bristle pattern of the second-leg basitarsus inDrosophila melanogaster was studied as a function of the number and size of the cells on this segment in well-fed and starved wild-type flies, in triploid flies, and in two mutants (dachs andfour-jointed) that have abnormally short basitarsi. The second-leg basitarsi of well-fed, wild-type flies from 22 otherDrosophila species were studied in a similar manner. There are typically 8 longitudinal rows of evenly-spaced bristles on the second-leg basitarsus, and in each row the number of bristles was consistently found to vary in proportion to the estimated number of cells along the segment, and the interval between bristles was found to vary in proportion to the average cell diameter on the segment. These correlations are interpreted to mean that the spacing of the bristles within each row is controlled developmentally, whereas the number of bristles is not. The interval between bristles is evidently measured either as a fixed number of cells or as a distance which indirectly depends upon cell diameter.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848266
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    A comparative ultrastructural study of ‘glue’ production and secretion of the salivary glands in different species of theDrosophila melanogaster group (1979)
    Springer
    Development genes and evolution 187 (1979), S. 329-354 
    Details
    ISSN: 1432-041X
    Keywords: Glue proteins ; Secretory proteins ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Salivary gland cells of members of theDrosophila melanogaster group (from four different subgroups) were examined electron microscopically and histochemically during the late larval period of development. The secretory product, which is supposed to be utilized as ‘glue’ at the time of puparium formation, appears, by analogy to Palade and Jamieson's results, to be synthesized partially in the rough endoplasmic reticulum (RER) and partially in the Golgi complex. The latter is also the usual site of the packaging of the product into secretory granules, except in the case of one of the secretory granule components ofD. lucipennis. The phylogenetic relationships among the subgroups, implied by the morphological appearance of the secretory granules, fit well with the existing phylogenetic relationships within the group. The secretory granules of each species have their own morphological features; granules of species of the same subgroup share some of these features. Secretion occurs from the cells via exocytosis during which the morphology of the secretory granules changes. Light microscope examination of PAS (Periodic Acid-Schiff reaction) stained glands shows a strong positive reaction in most species, with the exception of the species of thesuzukii subgroup which show a weak, or a negative reaction (D. rajasekari). Electron histochemical localization of polysaccharides in the secretory granules was possible inD. melanogaster and the species of theananassae subgroup.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848468
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Autonomous yolk protein synthesis in ovaries ofDrosophila cultured in vivo (1979)
    Springer
    Development genes and evolution 187 (1979), S. 255-266 
    Details
    ISSN: 1432-041X
    Keywords: Yolk proteins ; Hormonal control ; Electrophoresis ; In vivo culture ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Immature ovaries ofDrosophila mercatorum were injected into young larvae and into adult males ofD. mercatorum, D. melanogaster, D. hydei, D. virilis, andZaprionius vittiger. These homo- and heteroplastic transplantations allow normal vitellogenesis to occur in the donor ovary. By SDS gel electrophoresis, we identified the major species-specific yolk proteins of mature eggs (stage 14) which were exclusively of donor-specific origin. Other experiments withD. hydei andZ. vittiger showed that, when females were used as hosts, the host-specific yolk proteins became incorporated into the donor eggs. When two immature ovaries, one ofD. mercatorum and one ofD. hydei, were co-cultured in males, again only the donor-specific yolk proteins were found in the mature eggs implying that these yolk proteins were not released into the host hemolymph. A parthenogenetic strain ofD. mercatorum was used to demonstrate the ability of transplanted immature ovaries to produce viable eggs which can give rise to fertile adults. The role of the species-specific yolk proteins is discussed with respect to the dual origin of these proteins during normal vitellogenesis, i.e., an autonomous synthesis within the ovary itself in addition to the well-known production by the fat body. Further experiments with pupae as hosts indicate that even in the absence of juvenile hormone and in the presence of high doses of ecdysone, vitellogenesis can proceed within the donor ovary. Based on these experiments, a new hyopthesis on the hormonal control of vitellogenesis inDrosophila is presented. We propose that yolk proteins derived from the fat body are controlled by juvenile hormone, whereas the independent and autonomous vitellogenesis within the ovary itself is controlled by endogenously synthesized ecdysone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848621
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Early development of the thoracic discs ofDrosophila (1979)
    Springer
    Development genes and evolution 187 (1979), S. 375-379 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Segmentation ; Primordial size ; Gynandromorphs ; Bithorax mutants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We estimate the number of blastoderm cells which generate the thoracic imaginal discs ofDrosophila. At hatching the wing disc is twice the size of the haltere disc, but the results suggest that both discs develop from a similar number of blastoderm cells. Two homeotic mutations, which transform the haltere into wing, affect embryonic growth but not the primordial number. All the segmental primordia may be of similar size and each may be similarly subdivided into a larger anterior, and a smaller posterior polyclone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848471
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Fusion ofDrosophila eye-antennal imaginal discs during differentiation in vitro (1979)
    Springer
    Development genes and evolution 185 (1979), S. 363-370 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Imaginal discs ; Pattern formation ; β-ecdysone ; Tissue culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Pairs of eye-antennal discs, attached to the cephalic ganglia, were cultured in vitro with a concentration of β-ecdysone optimal for imaginal differentiation. The eye-antennal discs fused to form a vesicle inside which the antennae were partially everted, and on the inner surface of which imaginal structures differentiated. The epithelium of the discs was continuous, and an integrated pattern of bristles and hairs differentiated in vitro. In particular, the median ocellus, a unified structure derived partially from each disc, differentiated normally.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848522
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Pattern specification in imaginal discs ofDrosophila melanogaster (1979)
    Springer
    Development genes and evolution 186 (1979), S. 1-25 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Leg imaginal disc ; Pattern duplication ; Genetic mosaics ; Compartments
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary l(1)su(f)mad-ts (mad) is a new temperature-sensitive (ts) lethal mutant ofDrosophila melanogaster which produces duplicated legs after temperature pulse treatment during larval development. The ts-lethality was studied in temperature experiments and genetic mosaics. Temperature pulses given during two distinct TSPs of larval development result in two different types of leg pattern duplication. “Total” differ from “partial” duplications with respect to the affected leg compartments and the orientation of the planes of symmetry which are perpendicular to the dorso-ventral and the proximo-distal leg axes in total and partial duplications, respectively. Genetic mosaic studies indicate (i) disc autonomy of leg pattern duplication, (ii) clonal separation of the anlagen of the two pattern copies, and (iii) clonal restriction along the antero-posterior compartment border in the two pattern copies of totally duplicated legs. The results suggest thatmad leg pattern duplication is caused by a change in positional information rather than by cell death and subsequent regeneration. Our data are compatible with the assumption that during normal development the leg disc cells acquire information about their position within the disc with respect to the different leg axes independently and at different times.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848105
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    A clonal analysis of the relationship of duplicated bristles inDrosophila (1979)
    Springer
    Development genes and evolution 186 (1979), S. 267-271 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Bristle formation ; Differential divisions ; Clonal analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Two possible mechanisms are considered for the occurrence of experimentally or genetically induced duplications of bristles: extra cell division of a bristle mother cell versus determination of more than one mother cell. From a clonal analysis it appears that duplications induced by actinomycin-D arise by the latter mechanism, whereas those found in the mutantspl seem to arise by the former mechanism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848592
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    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
    Keywords: Chick embryo ; Bone ; Organ culture ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441158
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    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
    Keywords: Bone ; Bone formation ; Calcification ; Calcification nodule ; EM
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441162
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    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
    Keywords: Bone ; Femur ; Strength ; Density ; Age
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441170
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    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
    Keywords: Bone ; Rickets ; Hypophosphatemia ; Microradiography ; D-resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441169
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    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
    Keywords: Oxygen uptake ; Bone ; Oxygen tension ; Carbon dioxide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441180
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    X-ray diffraction of the calcified tissues inPolypterus (1979)
    Springer
    Calcified tissue international 28 (1979), S. 37-42 
    Details
    ISSN: 1432-0827
    Keywords: X-ray diffraction ; Hydroxyapatite ; Whitlockite ; Fish (Pisces) ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441216
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    Disordered mineral metabolism produced by ketogenic diet therapy (1979)
    Springer
    Calcified tissue international 28 (1979), S. 17-22 
    Details
    ISSN: 1432-0827
    Keywords: Anticonvulsant ; Ketogenic diet ; Calcium ; Vitamin D ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441213
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    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
    Keywords: Bone ; Bone cells ; Cyclic AMP ; Osteoclast activating factor ; Lymphokine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441214
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Bone metabolism, parathyroid hormone, and calcitonin in paraplegia (1979)
    Springer
    Calcified tissue international 27 (1979), S. 199-204 
    Details
    ISSN: 1432-0827
    Keywords: Bone ; Parathyroid hormone ; Calcitonin ; Osteoporosis ; Paraplegia ; Hydroxyproline
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441186
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    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
    Keywords: Bone ; Vitamin D ; Acidosis ; Phosphate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441191
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    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
    Keywords: Proline ; Cartilage ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441197
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    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
    Keywords: Bone ; Bending rigidity ; Disuse atrophy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441171
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    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
    Keywords: Anticonvulsants ; Calcium ; Vitamin D ; Parathyroid hormone ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441155
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    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
    Keywords: Calcium ; PTH ; 1,25(OH)2D ; Acid ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441241
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    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
    Keywords: Glycosaminoglycans ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02408073
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    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
    Keywords: Bone ; Culture ; Resorption ; Acidosis ; Alkalosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02408049
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Purification and properties of the enzymes from Drosophila melanogaster that catalyze the synthesis of sepiapterin from Dihydroneopterin triphosphate (1979)
    Springer
    Biochemical genetics 17 (1979), S. 371-390 
    Details
    ISSN: 1573-4927
    Keywords: sepiapterin ; Drosophila ; biosynthesis ; pteridines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Sepiapterin synthase, the enzyme system responsible for the synthesis of sepiapterin from dihydroneopterin triphosphate, has been partially purified from extracts of the heads of young adult fruit flies (Drosophila melanogaster). The sepiapterin synthase system consists of two components, termed “enzyme A” (MW 82,000) and “enzyme B” (MW 36,000). Some of the properties of the enzyme system are as follows: NADPH and a divalent cation, supplied most effectively as MgCl2, are required for activity; optimal activity occurs at pH 7.4 and 30 C; the K m for dihydroneopterin triphosphate is 10 µm; and a number of unconjugated pterins, including biopterin and sepiapterin, are inhibitory. Dihydroneopterin cannot be used as substrate in place of dihydroneopterin triphosphate. Evidence is presented in support of a proposed reaction mechanism for the enzymatic conversion of dihydroneopterin triphosphate to sepiapterin in which enzyme A catalyzes the production of a labile intermediate by nonhydrolytic elimination of the phosphates of dihydroneopterin triphosphate, and enzyme B catalyzes the conversion of this intermediate, in the presence of NADPH, to sepiapterin. An analysis of the activity of sepiapterin synthase during development in Drosophila revealed the presence of a small amount of activity in eggs and young larvae and a much larger amount in late pupae and young adults. Sepiapterin synthase activity during development corresponds with the appearance of sepiapterin in the flies. Of a variety of eye color mutants of Drosophila melanogaster tested for sepiapterin synthase activity, only purple (pr) flies contained activity that was significantly lower than that found in the wild-type flies (22% of the wild-type activity). Further studies indicated that the amount of enzyme A activity is low in purple flies, whereas the amount of enzyme B activity is equal to that present in wild-type flies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00498976
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Genetic and cytogenetic studies of four glycolytic enzymes in Drosophila melanogaster: Aldolase, triosephosphate isomerase, 3-phosphoglycerate kinase, and phosphoglucomutase (1979)
    Springer
    Biochemical genetics 17 (1979), S. 769-783 
    Details
    ISSN: 1573-4927
    Keywords: Drosophila ; aldolase ; triosephosphate isomerase ; glycolysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Four glycolytic enzymes in Drosophila melanogaster have been genetically and/or cytogenetically mapped. The structural gene for aldolase (Ald) has been genetically mapped to 3-91.5 and cytogenetically localized to 97A-B. Tpi, the structural gene for triosephosphate isomerase, has been genetically mapped to 3-101.3 and cytogenetically localized to 99B-E. Utilizing closer-flanking markers than the previous mapping, Pgk, the structural gene for 3-phosphoglycerate kinase, has been mapped to 2-5.9; cytogenetically it was found to lie in the interval between 22D and 23E3. The cytogenetic location of Pgm, the structural gene for phosphoglucomutase which has been located genetically at 3-43.4, was determined to be in 72D1-5.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00502135
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    Ontogeny, cell distribution, and the physiological role of NADP-malic enzyme in Drosophila melanogaster (1979)
    Springer
    Biochemical genetics 17 (1979), S. 867-879 
    Details
    ISSN: 1573-4927
    Keywords: malic enzyme ; development ; NADP enzymes ; Drosophila ; nutrition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract NADP-malic enzyme (NADP-ME) (E.C. 1.1.1.40) is situated in the cytosol of Drosophila melanogaster. Both the tissue activity and CRM level of NADP-ME parallel changes in the dosage of a gene, Men +, located in region 87C2-3 to 87D1-2 of the third chromosome. The tissue activity of NADP-ME is very high in early third instar larvae, providing about 33% of the NADPH at this life stage. The tissue activity declines during pupal development but increases as the adult ages. The concentration of NADP-ME CRM and tissue activity are coordinately increased in third instar larvae by dietary carbohydrate and decreased by dietary lipid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00504309
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Genetic and biochemical aspects of sucrase from Drosophila melanogaster (1979)
    Springer
    Biochemical genetics 17 (1979), S. 897-907 
    Details
    ISSN: 1573-4927
    Keywords: sucrase ; Drosophila ; segmental aneuploidy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Isoelectrofocusing of abdominal extracts of Drosophila melanogaster revealed the existence of two forms of sucrase (E.C. 3.2.1.26). One form exhibited an isoelectric point of 4.63±0.02 while the other form exhibited an isoelectric point of 4.83±0.02. The localization of the structural gene for sucrase is proposed on the basis of enzyme determinations in a series of duplication- and deletion-bearing aneuploids. We suggest that the sucrase structural gene lies between 31CD and 31EF on the left arm of chromosome 2 and that the two forms of abdominal sucrase derive from a common protein coded for by a single sucrase gene designated Sucr +.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00504311
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Genetic and cytogenetic studies of the malate dehydrogenases of Drosophila melanogaster (1979)
    Springer
    Biochemical genetics 17 (1979), S. 947-956 
    Details
    ISSN: 1573-4927
    Keywords: malate dehydrogenase ; cytoplasmic ; mitochondrial ; cytogenetic ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Genetic and cytogenetic locations of the structural genes for the NAD-dependent malate dehydrogenases have been studied. The mitochondrial form (mMDH) is coded for by a gene (Mdh) found at 62.6 on the third chromosome and included in Df(3R)P14, which includes 90C2–91A3 in the salivary gland chromosomes. Based on its inclusion within several J (Jammed; 2–41.0) deficiencies, the structural gene (cMdh) for the cytoplasmic form (cMDH) was determined to lie in region 31B-E, confirming the earlier finding of Grell. Flies lacking any cMDH activity (cMdhn-γ10069/ Df(2L)J-der-27) were both viable and fertile.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00504314
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Drosophila alcohol dehydrogenase activity in vitro and in vivo: Effects of acetone feeding (1979)
    Springer
    Biochemical genetics 17 (1979), S. 553-563 
    Details
    ISSN: 1573-4927
    Keywords: alcohol dehydrogenase ; Drosophila ; acetone ; multiple forms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract When adult Drosophila are placed on medium containing 0.5% acetone, their level of alcohol dehydrogenase activity drops rapidly. At the same time, the proportion of activity in the various electrophoretic forms of the enzyme shifts; most of the activity becomes localized in what is ordinarily a minor form of the enzyme. Moreover, the loss of enzyme activity occurs in vivo as well, as shown by sensitivity to ethanol poisoning, insensitivity to pentenol treatment, and inability to utilize ethanol as an energy source. These observations are discussed in light of a model advanced for the origin of the multiple forms of alcohol dehydrogenase in Drosophila.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00498890
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    Form II DNA-dependent RNA polymerase from Drosophila melanogaster: General in vitro catalytic properties and template interactions (1979)
    Springer
    Biochemical genetics 17 (1979), S. 77-95 
    Details
    ISSN: 1573-4927
    Keywords: Drosophila ; form II RNA polymerase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Several in vitro properties of partially purified form II RNA polymerase from Drosophila melanogaster embryo nuclei are described. The enzyme preparation is free from contaminating RNase, protein kinase, and polyphosphate kinase activities and can be used to study the incorporation of γ-32P-labeled nucleoside triphosphates. The enzyme exhibits a biphasic heat inactivation pattern which is probably related to differential lability of its two subforms. However, a considerable protection against heat inactivation is provided by the nucleoside triphosphates present in the in vitro reaction system such that the enzyme catalyzes RNA synthesis in a nearly linear mode for over 2 hr at 30 C. Two initiation inhibitors, rifamycin AF/013 and polyriboinosinic acid (poly[I]), were tested against this enzyme. Rifamycin AF/013 was found unsuitable for critical studies because of the high concentrations necessary for total inhibition (200 µg/ml) and particularly because of the obligate use of solvents which secondarily have a destabilizing effect on native DNA. Poly[I] was found to effectively block initiation at very low concentrations (1 µg/ml). The enzyme rapidly forms poly[I]-resistant preinitiation complexes on both double- and single-stranded DNA. These complexes decay with a half-life of 2.5–3 min. RNA synthesis from poly[I]-resistant complexes amounts to 10% of the total potential synthesis on both double- and single-stranded DNA. Enzyme-DNA saturation experiments indicate that the form II enzyme discriminates two types of sites on Drosophila DNA, tight binding and weak binding, from which RNA synthesis proceeds slowly and rapidly, respectively. The tight-binding sites appear to be analogous to those sites with which the enzyme is able to form poly[I]-resistant complexes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00484475
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Allozyme genotype-environment relationships in natural populations of Drosophila buzzatii (1979)
    Springer
    Biochemical genetics 17 (1979), S. 105-126 
    Details
    ISSN: 1573-4927
    Keywords: Drosophila ; electrophoresis ; enzyme polymorphism ; genotype-environment associations ; natural selection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Allozyme frequency data from natural populations of Drosophila buzzatii were analyzed for genotype-environment relationships. Allele frequency and heterozygosity at six loci polymorphic throughout eastern Australia and a number of environmental factors (both means and variabilities) were examined by a variety of multivariate techniques. Significant genotype-environment associations were found for five of the six loci, and after correcting for geographic location significant associations remained for Est-2 and Adh-1 gene frequencies and heterozygosities and for Pgm gene frequencies. The results are discussed in relation to selection and gene flow and provide the basis for laboratory studies to disentangle confounded effects of (1) environmental means and environmental variabilities and (2) allele frequency and heterozygosity, and thus to further test for and determine the nature of any natural selection at particular allozyme loci.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00484477
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Studies of esterase 6 in Drosophila melanogaster. I. The genetics of a posttranslational modification (1979)
    Springer
    Biochemical genetics 17 (1979), S. 167-183 
    Details
    ISSN: 1573-4927
    Keywords: esterase 6 ; Drosophila ; enzyme modification ; leucine aminopeptidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A locus has been found, an allele of which causes a modification of some allozymes of the enzyme esterase 6 in Drosophila melanogaster. There are two alleles of this locus, one of which is dominant to the other and results in increased electrophoretic mobility of affected allozymes. The locus responsible has been mapped to 3-56.7 on the standard genetic map (Est-6 is at 3-36.8). Of 13 other enzyme systems analyzed, only leucine aminopeptidase is affected by the modifier locus. Neuraminidase incubations of homogenates altered the electrophoretic mobility of esterase 6 allozymes, but the mobility differences found are not large enough to conclude that esterase 6 is sialylated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00484483
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    The α-glycerophosphate dehydrogenase (α-gpdh) polymorphism in Drosophila melanogaster: adult survival under temperature stress (1979)
    Springer
    Theoretical and applied genetics 54 (1979), S. 235-237 
    Details
    ISSN: 1432-2242
    Keywords: Drosophila ; α-Glycerophosphate dehydrogenase ; Polymorphism ; Temperature selection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary As a test of the hypothesis that adult temperature stress is an important component of natural selection maintaining the α-gpdh polymorphism, we have looked for differential survival among genotypes subjected to (i) heat shock and (ii) cold shock. Factorial ANOVAR, taking account of genotype, sex and temperature-stress indicated that genotype did not contribute to the variance of survival proportion per vial. We have not therefore found evidence to support our hypothesis. Incidental to the above was a significant sex-temperature interaction. Thus, adult females showed higher survival than males under heat stress, while under cold stress, there was no indication of a survival difference between the sexes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00267713
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    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
    Keywords: Nachw. von Carbamatpesticiden in biolog. Material ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00481656
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    Information content and equivocation of TLC identification procedures (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 361-365 
    Details
    ISSN: 1618-2650
    Keywords: Chromatographie, Dünnschicht ; Informationsgehalt und »Äquivokation«
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 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.
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00468523
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    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
    Keywords: Trenn. von Arylbenzolsulfonylthiocarbamiden ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00468534
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Universelle, halogenfreie DC-Fließmittel für Arzneisubstanzen (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 398-401 
    Details
    ISSN: 1618-2650
    Keywords: Analyse von pharmazeut. Produkten ; Chromatographie, Dünnschicht ; halogenfreie Fließmittelsysteme
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 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.
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00539712
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    Zur Veränderung der Fluorescenzintensität polycyclischer Aromaten auf Dünnschichtplatten (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 24-29 
    Details
    ISSN: 1618-2650
    Keywords: Best. von Polycyclen in Wasser ; Chromatographie, Dünnschicht ; Änderung der Fluorescenzintensität
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 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.
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00490944
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Zur Chromatographie von Metallchelaten (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 297 (1979), S. 138-143 
    Details
    ISSN: 1618-2650
    Keywords: Trenn, der Metallchelate von 8-Mercaptochinolin ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 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.
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00483594
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    Zur Chromatographie von Metallchelaten (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 297 (1979), S. 144-147 
    Details
    ISSN: 1618-2650
    Keywords: Trenn. der Metallchelate von 1-Hydroxy-2-pyridinthion ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 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.
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00483595
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    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
    Keywords: Trenn. von Guanylpyrazolnitraten ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00470050
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    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
    Keywords: Synaptic contacts ; Neurosecretion ; Lymnaea stagnalis ; Tilting stage electron microscopy ; Serial section reconstruction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00232006
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    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
    Keywords: Neurosecretion ; Ground squirrel (Citellus erythrogenys Brandt) ; Seasonal changes ; Hibernation ; Quantitative analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234197
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    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
    Keywords: Olfactory bulb ; Giant cells ; Neurosecretion ; Electron microscopy ; Labyrinth fish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236086
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    Diphenylamin im DC-Fließmittel als universelles Detektionsmittel (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 296 (1979), S. 45-45 
    Details
    ISSN: 1618-2650
    Keywords: Chromatographie, Dünnschicht ; Diphenylamin als Detektionsmittel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00481170
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    Vollautomatische rechnergesteuerte Auswertung von Dünnschicht-Chromatogrammen (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 296 (1979), S. 369-373 
    Details
    ISSN: 1618-2650
    Keywords: Chromatographie, Dünnschicht ; vollautomat. Auswertung von Chromatogrammen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 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.
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00479975
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Preparation of cell cultures fromDrosophila melanogaster embryos (1979)
    Springer
    Methods in cell science 5 (1979), S. 1019-1022 
    Details
    ISSN: 1573-0603
    Keywords: cell cultures ; Drosophila ; cell differentiation ; embryos
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00919723
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    Preparative isolation and short-term organ culture of imaginal discs ofDrosophila melanogaster (1979)
    Springer
    Methods in cell science 5 (1979), S. 1055-1062 
    Details
    ISSN: 1573-0603
    Keywords: Drosophila ; imaginal discs ; ecdysteroids ; morphogenesis ; organ culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00919788
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    Oviposition site preference inDrosophila (1979)
    Springer
    Behavior genetics 9 (1979), S. 233-241 
    Details
    ISSN: 1573-3297
    Keywords: Drosophila ; oviposition site preference ; ethanol ; Darwininian fitness
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Comparative studies of oviposition site preference (OSP) inDrosophila suggest that choice of oviposition site is an important adaptive behavior which influences individual fitness and the potential of populations for speciation. OSP has been investigated under conditions which provided females with a choice of standard medium or medium containing ethanol for oviposition. OSP is an extremely labile behavior in the laboratory, but a technique has been developed which minimizes variation between replicates and allows the detection of OSP differences between semispecies of a single species. An analysis of the OSP of 14Drosophila species shows that this behavior is not correlated with phylogenetic relationships. OSP with respect to ethanol may be correlated with the presence of ethanol in the environment and the activity of alcohol dehydrogenase in the species tested.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01071304
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Inbreeding and heterogamic mating: An alternative to Averhoff and Richardson (1979)
    Springer
    Behavior genetics 9 (1979), S. 249-256 
    Details
    ISSN: 1573-3297
    Keywords: mating speed ; sexual vigor ; inbreeding ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract An alternative explanation to the pheromonal control of mating through chemoreceptor saturation proposed by Averhoff and Richardson (1974) is offered for the apparent rise in heterogamic mating in their experiments, after several generations of full-sib mating. In a multiple-choice mating between two genotypic strains differing in their level of sexual vigor, there is a sequence from heterogamic to homogamic mating. It is proposed that, by reducing mating speed, inbreeding changes the rate of this sequence but not its pattern, so the apparent level of heterogamic mating will increase during inbreeding, for a fixed observation period. This hypothesis was tested using the Kence-Bryant model of mating success.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01068204
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Preference for ethanol inDrosophila melanogaster associated with the alcohol dehydrogenase polymorphism (1979)
    Springer
    Behavior genetics 9 (1979), S. 359-365 
    Details
    ISSN: 1573-3297
    Keywords: ethanol preference ; ADH ; behavior ; genetics ; Drosophila ; Adh electromorphs ; oviposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Two alcohol dehydrogenase genotypes (Adh F /Adh F andAdh S /Adh S ) exhibit different behavioral responses when presented with a choice between ethanol and nonethanol environments at the larval stage but not at the adult stage. The larval preferences are correlated with alcohol dehydrogenase activity, which also differs between genotypes. Since ethanol is important in the ecology of this species, the preference may be related to microhabitat selection in nature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01066974
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Genetic analysis of lines selected for wing vibration inDrosophila melanogaster (1979)
    Springer
    Behavior genetics 9 (1979), S. 579-584 
    Details
    ISSN: 1573-3297
    Keywords: Drosophila ; courtship behavior ; artificial selection ; genetic analysis ; heritability ; wing vibration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Selection for the wing vibration component of courtship in the Oregon-R stock ofD. melanogaster was practiced for 44 generations. Selection was successful, indicating that there is genetic variation for the trait in the Oregon-R stock. The mean realized heritability of the trait, based on the first 11 generations of selection, was 15%. Biometrical analysis showed that there is some additive genetic variance for the trait with the possibility of some ambidirectional dominance. No maternal effects for the trait were found.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01067354
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Adaptiveness of a rare male mating advantage under heterosis (1979)
    Springer
    Behavior genetics 9 (1979), S. 51-54 
    Details
    ISSN: 1573-3297
    Keywords: rare male mating advantages ; sexual selection ; heterosis ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract It is shown that minority mating advantages, so commonly observed inDrosophila, would be selectively advantageous in a heterotic system. When an allele is below the equilibrium frequency maintained by heterosis, females mating with that homozygote produce offspring of highest mean fitness.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01067121
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    Genetics of phototactic behavior inDrosophila ananassae, a member of theMelanogaster species group (1979)
    Springer
    Behavior genetics 9 (1979), S. 61-67 
    Details
    ISSN: 1573-3297
    Keywords: phototaxis maze ; sex-linked behavior ; Drosophila ; chromosomal homologies ; species differences
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Using Hirsch-Hadler phototaxis mazes, selection for photopositive and photonegative behavior was carried out for 21 generations inDrosophila ananassae. The chromosomes that are important in influencing photomaze behavior inD. ananassae are different from what has been observed for other members of themelanogaster species group, and the differences cannot be entirely attributed to the chromosome rearrangements which have occurred during the evolution of these related species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01067123
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    A maximum likelihood statistical method for analyzing frequency-dependent fitness experiments (1979)
    Springer
    Behavior genetics 9 (1979), S. 7-21 
    Details
    ISSN: 1573-3297
    Keywords: frequency-dependent fitness ; statistical analysis ; logistic regression models ; maximum likelihood estimation ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Experiments on frequency-dependent fitness often consist of forming pairwise mixtures of distinguishable types at several frequency combinations. These mixtures are allowed to undergo competition, after which the performance of each type is enumerated. A statistical method for analyzing such experiments is described in this article. This method, suggested previously for other purposes, is superior to the statistical procedures now commonly employed. It involves the maximum likelihood estimation of parameters for two logistic regression models: one which assumes that fitness is frequency-dependent, the other that fitness is constant over changing frequency. Estimators for both models can be calculated without difficulty using an iterative numerical algorithm implemented in a Fortran computer program available from the authors. Fitting both models allows for the construction of a likelihood ratio statistical test for whichever model is more appropriate. The method is illustrated by application to publishedDrosophila data from differential mating success experiments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01067118
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    In vitro induced pinocytotic activity by a juvenile hormone analogue in oocytes of Drosophila melanogaster (1979)
    Springer
    Cell & tissue research 203 (1979), S. 241-247 
    Details
    ISSN: 1432-0878
    Keywords: Pinocytotic activity ; Juvenile hormone ; Drosophila ; Oocytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Pinocytotic activity has been analyzed in Drosophila oocytes following either in vivo or in vitro exposure to horseradish peroxidase. The enzyme tracer gains access to the yolk spheres only when supplied to the oocyte in vivo. In oocytes cultured in vitro, peroxidase remains restricted to the residual coated vesicles and to the tubular profiles formed in excess in the cortical ooplasm. In an attempt to induce peroxidase uptake by oocytes cultured in vitro, various incubations were tested. Among these, hemolymph from both sexes is capable of promoting peroxidase uptake up to a level comparable to that detectable in vivo. On the other hand, fat body extracts fail to promote such cellular activity. Finally, the juvenile hormone analogue ZR-515 is shown to be the only factor required to promote pinocytotic activity under the experimental conditions tested. The observations are interpreted to indicate that vitellogenin has no inductive role on pinocytosis but simply acts by adhering to the forming coated vesicles which in turn are produced by the oolemma in response to the action of juvenile hormone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237238
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    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
    Keywords: Neurohemal organ ; Neurosecretion ; Moulting gland ; Ultrastructure ; Crustaceans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: 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.
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233270
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    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
    Keywords: Neurosecretion ; Immunofluorescence ; Crustacea ; X-organ ; Hyperglycemic Hormone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233650
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    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
    Keywords: Neurosecretion ; Corpus cardiacum ; Corpus allatum ; Acheta domesticus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00232004
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    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
    Keywords: Neurosecretion ; Hypothalamo-hindbrain pathway ; Rat ; Blood pressure ; Milk ejection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00240105
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    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
    Keywords: Trenn. von Benzodiazepinen ; Chromatographie, Dünnschicht ; Metaboliten
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 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.
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00523935
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Dünnschicht-chromatographischer Nachweis von IOXYNIL in biologischem Material (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 288-288 
    Details
    ISSN: 1618-2650
    Keywords: Nachw. von Ioxynil in Biolog. Material ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00481657
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    Alcohol separation by thin-layer chromatography. II (1979)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 263-265 
    Details
    ISSN: 1618-2650
    Keywords: Trenn. von Alkoholen ; Chromatographie, Dünnschicht ; C1-C20, 6 Trennsysteme, Dinitrobenzoate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 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.
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00481489
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    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
    Keywords: Trenn. von Arylazopyraolen ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00481495
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    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
    Keywords: Trenn. von Antimikrobiellen Verbindungen ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 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.
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00694659
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    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
    Keywords: Trenn. von anorg. Ionen ; Chromatographie, Dünnschicht ; DCTA-imprägniert
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00694660
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    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
    Keywords: Identifizierung von Arylhydrazin-benzylsulfonylmethylpyrazolinonen ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00468541
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    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
    Keywords: Analyse von Sulfonamiden ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00581378
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    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
    Keywords: Bone ; Strain
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02447060
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Scanning electron microscope study of separated calcospherites from the matrices of different mineralizing systems (1978)
    Springer
    Calcified tissue international 26 (1978), S. 47-49 
    Details
    ISSN: 1432-0827
    Keywords: Matrix vesicles ; Calcospherites ; Mineralization ; Bone ; Dentin ; Cartilage ; SEM
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Mineral particle cluster, corresponding to calcospherites or matrix vesicle-initiated clusters in calcifying cartilage and dentin and to collagen bundle-related mineralization in lamellar bone, have been isolated from NaOCl solutions used to dissolve the organic matrix in preparation of anorganic mineralizing fronts for scanning electron microscopy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02013233
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Mechanism of osteoclastic bone resorption: A new hypothesis (1978)
    Springer
    Calcified tissue international 26 (1978), S. 81-84 
    Details
    ISSN: 1432-0827
    Keywords: Osteoclasts ; Bone ; Resorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Osteoclastic bone resorption involves the solubilization of the mineral salts and the degradation of noncollagen bone matrix and collagen fibrils. As no recognizable collagen fibrils have ever been reported within cytoplasmic vacuoles in osteoclasts, it is generally assumed that the collagen fibrils are digested extracellularly in the resorption zone. The extent to which lysis occurs extracellularly and whether or not the osteoclasts phagocytose the degradation products remain to be established. In the present communication, a hypothesis is presented suggesting the possibility that osteoclastic resorption of bone involves the participation of two different cell types. According to this hypothesis, osteoclastic bone resorption is initiated by osteoclasts that demineralize areas of bone and degrade noncollagen bone matrix. After the osteoclasts have moved away or become partially detached from the demineralized site, the exposed collagen fibrils are phagocytosed by mononuclear, fibroblast-like or monocyte-derived cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02013238
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    Plasma disappearance of rabbit α2 HS-glycoprotein and its uptake by bone tissue (1978)
    Springer
    Calcified tissue international 26 (1978), S. 155-161 
    Details
    ISSN: 1432-0827
    Keywords: Plasma protein ; Glycoprotein ; Bone ; Glucosamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Plasmaα 2HS-glycoprotein is specifically accumulated in calcified tissues. In the present studies this glycoprotein was isolated from plasma and after iodination with iodine-125 was injected intravenously into young rabbits. The tissue distribution and plasma disappearance rate of this radioactively labeled material were determined. Of the various tissues studied, bone showed the greatest retention of labeled glycoprotein expressed as percentage of the injected dose per gram tissue relative to the plasma content. The rate of loss of iodinatedα 2HS-glycoprotein from plasma was similar to that ofα 2HS-glycoprotein labeled endogenously by using14C-glucosamine or3H-glucosamine. The uptake of exogenously labeled3I-α 2HS-glycoprotein into bone tissue expressed as a percentage of the injected dose was similar to that of endogenously labeled14C-α 2HS-glycoprotein. These results suggest that the125I-labeled material can be used to study further the metabolism ofα 2HS-glycoprotein by bone tissue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02013251
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    Effect of mithramycin on boneβ-glucuronidase and resorption (1978)
    Springer
    Calcified tissue international 26 (1978), S. 209-213 
    Details
    ISSN: 1432-0827
    Keywords: Mithramycin ; Bone ; β-Glucuronidase ; KT medium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Mithramycin suppresses bone resorption. Its effect on the synthesis and release of β-glucuronidase (a referent for lysosomal enzymes) in mouse calvarial explants was studied in an in vitro culture system. A newly described medium (designated as KT medium) was introduced in this specific study. Mithramycin initially inhibited the release of β-glucuronidase into the medium and resulted in an ultimate accumulation of this enzyme in the bone. These results suggest that inhibition of bone resorption by mithramycin may be attributed to interference in release of lysosomal enzymes from bone cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02013260
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Differentiation in vitro of larval and adult muscles from embryonic cells ofDrosophila (1978)
    Springer
    Development genes and evolution 184 (1978), S. 233-249 
    Details
    ISSN: 1432-041X
    Keywords: Tissue culture ; Muscles ; Metamorphosis ; Ecdysone ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The differentiation of muscles in primary cultures of cells fromDrosophila melanogaster embryos was investigated. In early cultures, and in the absence of exogenous ecdysone, two main classes of muscle were found. Comparison, by light and electron microscopy, of one of these classes (the “myotube” class) with muscles from third instar larvae shows that this class corresponds to the muscles of the body wall of the larva. When α- or β-ecdysone is added to the cultures, these undergo a number of metamorphic changes. Most of the larval muscles disappear, and two new types of muscle form. Ultrastructural and light microscopic examination of these two types indicates that they correspond to the two classes of skeletal muscle (fibrillar and tubular) found in adult flies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848256
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    Experimental analysis of sensory nerve pathways inDrosophila (1978)
    Springer
    Development genes and evolution 184 (1978), S. 273-283 
    Details
    ISSN: 1432-041X
    Keywords: Nervous system ; Development ; Imaginal discs ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The pathway of adult sensory nerves has been analysed in three experimental situations: (i) in flies with grossly abnormal thoracic morphology resulting from X-irradiation early during development, (ii) in flies which had been subjected to surgical operations late in the larval period, (iii) in homoeotic mutants. The results provide experimental support for a simple mechanism in which developing adult axons join the nearest larval nerve and are guided by it up to the central nervous system. In particular, experimental interference with normal development can result in nerves from different segments, or from dorsal and ventral appendages, joining each other and entering the central nervous system together.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848386
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    Cell clones and pattern formation: Developmental restrictions in the compound eye ofDrosophila (1978)
    Springer
    Development genes and evolution 184 (1978), S. 155-170 
    Details
    ISSN: 1432-041X
    Keywords: Developmental restrictions ; Compound eye ; Pattern formation ; Genetic mosaics ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Five regions of the compound eye have been found to be preferential boundaries for clones of labelledMinute + cells, and to act restrictively on the growth of cell clones after a given developmental stage. One of these regions is topographically related to the line of pattern inversion existing at the level of the equator. The results of experiments showing independency of origin of restriction lines and line of pattern inversion are reported.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848224
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    fs(1)K10, a germline-dependent female sterile mutation causing abnormal chorion morphology inDrosophila melanogaster (1978)
    Springer
    Development genes and evolution 184 (1978), S. 75-82 
    Details
    ISSN: 1432-041X
    Keywords: Egg shape ; Pole cell transplantation ; Sterility ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Females homozygous for a newly isolated mutation induced by ethyl methane sulphonate,fs(1)K10, lay abnormally shaped eggs in which the dorsal appendages of the chorion are enlarged and fused ventrally. The eggs are usually not fertilized and development is never normal beyond the blastoderm stage. The mutant was mapped to the tip of the X-chromosome with a meiotic position of 1–0.5 and a cytological location between 2B17 and 3A3. Using germ line mosaics constructed by transplantation of pole cells, it was shown that the abnormal morphology and the sterility are obtained only when the germ line is homozygous for the mutant.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848670
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    The embryonic organization of the genital disc studied in genetic mosaics ofDrosophila melanogaster (1978)
    Springer
    Development genes and evolution 185 (1978), S. 249-270 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Gynandromorphs ; Cell lineage ; Sexual dimorphism ; Genital discs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The embryonic organization of the sexually dimorphic genital disc was studied in genetic mosaics resulting (a) from early loss of a chromosome or (b) from mitotic recombination. (a) Early Loss of a Chromosome. Three types of mosaics were produced — purely female mosaics, purely male mosaics, and gynandromorphs. They show that the genital disc arises from a group of cells in the ventral region of the embryo somewhat larger than that giving rise to a single foreleg (Table 2). Within this group of cells three regions can be distinguished that are present in both sexes: an anterior, a medial, and a posterior one, with distances of only 3–4 sturts between adjacent regions. The anterior region gives rise to the female genitalia, the medial region to the male genitalia, and the posterior region forms the analia of both sexes and the parovaria of the female (Figs. 2 and 3). The relative positions of the three regions were deduced from sturt distances (Tables 1 and 5), and from frequencies of mosaicism (Table 2). (b) Mitotic recombination was induced at the blastoderm stage in order to produce twin spots in the external genitalia and analia of purely male and female flies. Clone sizes indicate that these structures arise from a small number of precursor cells (Table 4). Clones overlapped right and left sides, but no clones were found extending over analia and genitalia. However, within either the analia or the genitalia of each sex, no clonal restrictions could be observed, and the clones comprised structures that were up to 12 sturts apart. A comparison of clone sizes and sturt distances in the foreleg and in the genital disc indicates that equal gynandromorph distances involve equal numbers of cells in different regions on the ellipsoid egg (Fig. 5). The results obtained from all mosaics provide a consistent picture of the embryonic organization of the genital disc. This becomes apparent in the summarized fate maps (Fig. 4), where the map derived from normal gynandromorphs can be produced by a simple superposition of the male and the female maps. The data are also discussed with respect to mechanisms of sexual differentiation in the genital disc.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848355
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Positional information in imaginal discs transformed by homoeotic mutations (1978)
    Springer
    Development genes and evolution 185 (1978), S. 271-292 
    Details
    ISSN: 1432-041X
    Keywords: Homeotic mutations ; Imaginal disc ; Positional Information ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Mutations of the bithorax complex result in segmental transformations in the thorax and abdomen ofDrosophila. The haltere discs from larvae homozygous forbx 3 orpbx are transformed so that the discs contain cells that will produce wing cuticle as well as cells that produce haltere cuticle. The pattern regulation behavior of these discs has been examined. The fate maps of the two discs were established, and then the regulative behavior of a number of fragments from both types of mutant discs was established by culturing the fragments in vivo prior to metamorphosis. The most important conclusion from this work is that the cells producing, haltere cuticle and wing cuticle within the same disc share the same positional information and that they communicate during pattern regulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848356
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Radiogenic free radicals as molecular probes in bone (1978)
    Springer
    Calcified tissue international 25 (1978), S. 37-43 
    Details
    ISSN: 1432-0827
    Keywords: ESR ; Radiation free radicals ; CO3-Apatites ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Exposure of bone mineral to X-rays generates free radicals. These are usually very labile, but can be stabilized at liquid nitrogen temperatures for study by electron spin resonance spectroscopy. The free radicals thus detected in the present study included one with resonances arising from an electron excess center and 2 species with electron-deficit centers: a phosphate anion radical and a radical associated with carbonate. Each of these radicals seemed to be located chiefly at the mineral surface and was sensitive to the surface environment. Presence of an organic phase, as in whole bone, modified free radical production in a manner that suggests interference with the formation of electron deficit centers. Comparison with other synthetic minerals suggests that precipitated carbonateapatites are good models for bone mineral.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02010749
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Selective stimulation of net calcium efflux from chick embryo tibiae by parathyroid hormone in vitro (1978)
    Springer
    Calcified tissue international 25 (1978), S. 227-232 
    Details
    ISSN: 1432-0827
    Keywords: Parathyroid hormone ; Bone ; Calcium ; Chick embryo ; Organ culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The purpose of this study was to measure in an in vitro system the movement of Ca and phosphate (Pi) out of bone when treated with parathyroid hormone (PTH). Tibiae from 13-day chick embryos were incubated for up to 8 h in a defined medium containing 1.8 mM Ca. Medium samples were collected every 2 h and were analyzed for Ca, Pi and lactate. Net effluxes from the bones were calculated. When bones were incubated with PTH in the medium (1 U/ml), net Ca efflux was increased 44, 60 and 100% at 4, 6 and 8 h, respectively. At no time was net Pi efflux affected by the hormone. The well known PTH-stimulated lactate production was not seen until 8 h. Lower doses of PTH (0.1 and 0.3 U/ml) were also effective. Comparing PTH (1 U/ml) responsiveness at higher (2.2 mM) and lower (0.9 mM) medium Ca concentrations, showed that with 2.2 mM Ca no increased Ca efflux was seen, while with 0.9 mM Ca significant elevation in medium Ca occurred 2 h sooner than in the experiments using 1.8 mM Ca. In another experiment, varying the medium Pi level from 1 to 2 mM had no effect on the Ca response to PTH. In neither experiment was Pi release affected by PTH. The results of this study have led to the following conclusions: (1) PTH acts on bone to cause an early dose related increase in net Ca efflux; (2) the effect is specific for Ca, since it is not accompanied by an increased Pi efflux, and may be saturated by raising the medium Ca level; and (3) PTH-stimulated Ca efflux in this system is not correlated with, and is probably not a result of increased lactate production.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02010774
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    A bone resorbing substance from bovine serum albumin (brA) (1978)
    Springer
    Calcified tissue international 25 (1978), S. 233-240 
    Details
    ISSN: 1432-0827
    Keywords: Bone ; Bone resorption ; Albumin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary A fraction (brA), which causes resorption of fetal rat bones in vitro, has been concentrated from bovine serum albumin by anion exchange column chromatography on DEAE Sephadex. This active fraction has also been prepared using DEAE Sephadex A-50 by a batch method with a 0.09M NaCl, 0.1M TRIS buffer, pH 8.35. BrA was 10–30 times more potent than the original albumin. The retained material, which constitutes the bulk of the protein and has less activity than the original albumin, elutes with 0.45M NaCl. Similar treatment of serumα,β or γ globulins does not yield brA. Further enhancement of the bone resorbing activity of brA can be obtained with (NH4)2SO4 fractionation or extraction with CH3OH∶CHCl3. Heating at 55° C for 2 h or at 100° C for 10 min does not affect the activity; overnight incubation with protease destroys the bone resorbing effect. The bone resorbing activity is not removed by dialysis and does not correlate with the protease activity of the fraction. The action of brA is inhibited by 3 mM PO4, 1 μg/ml calcitonin or glucagon, 10−7 M dexamethasone or 0.02 μg/ml actinomycin D. The bone resorbing activity of brA is partially inhibited by 10−7–10−5 M indomethacin. PTH did not elicit bone resorption when added to cultures incubated in chemically defined medium supplemented with 0.1 mg/ml brA. However, brA did not inhibit PTH-induced resorption.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02010775
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    Oestrogen binding proteins in bone cell cytosol (1978)
    Springer
    Calcified tissue international 25 (1978), S. 249-254 
    Details
    ISSN: 1432-0827
    Keywords: Bone ; Oestrogens ; Oestrogen receptors ; Binding proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Attempts were made to demonstrate the presence of specific oestrogen binding proteins (“receptors”) in bone cells. High speed cytosol preparations of bone were incubated with several concentrations of radioactive oestradiol alone and with radioactive oestradiol in the presence of a specific antioestrogen, Nafoxidine. Separation of bound and free oestradiol was carried out by dextran coated charcoal treatment and by sucrose gradient ultracentrifugation. Several types of bones likely to be oestrogen-sensitive were investigated: human femoral heads, human phalanx, rat and rabbit calvaria, humeri and femora of female rats. In all experiments we were unable to demonstrate the presence of specific oestrogen receptors in bone cell cytosol indicating that the direct effect of oestrogens on bone, if present, is not mediated by specific oestrogen receptors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02010778
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    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
    Keywords: Bone ; Histology ; Microradiography ; Densitometry ; Computer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary A comparatively simple quantitative method for assessing bone morphology has been evolved. Microradiographs of thin sections of mandible have been scanned with a Joyce-Loebl double beam recording microdensitometer with a scanning autodensidater attachment, using a white beam. For each image the optical densities for all the pixels (picture elements) were divided into 10 groups. The limits of the division were fixed by the maximum and minimum densities occurring within the image. A computer generated map was produced which indicated the spatial distribution of the pixels within each group to which an arbitrarily chosen shading was attached. The number of pixels within each group is also shown on the map. The computer map was compared with the photomicrograph and, where necessary, the original section. The fractional area of hard tissue was then readily determined using the numerical values of each group of pixels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02013239
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    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
    Keywords: Chemisorption ; Surface area ; Hydroxyapatite ; Bone ; Enamel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The surface areas of three different samples of hydroxyapatite, samples of deproteinized bone, and samples of whole and deproteinized enamel were determined by adsorption of an adduct (the diglycidyl ether of bisphenol A with N-phenylglycine) from methylene chloride solution. In all cases, the surface areas of these samples agree well with those obtained by the BET (N2) method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02013248
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    Effect of sex steroids on bone collagen synthesis in vitro (1978)
    Springer
    Calcified tissue international 25 (1978), S. 105-110 
    Details
    ISSN: 1432-0827
    Keywords: Progesterone ; 17β estradiol ; Testosterone ; Tissue culture ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Although sex steroids are known to affect skeletal metabolism, their effects on bone collagen synthesis have not been studied. We have examined the direct effects of progesterone, 17β estradiol, testosterone, 5α dihydrotestosterone and dehydroepiandrosterone on bone collagen and noncollagen protein synthesis in cultures of calvaria obtained from 21-day fetal rats. Bones were incubated for 24 to 168 h and3H-proline was added for the last 2 h of culture. Incorporation of the label into collagenase-digestible protein (CDP)1 and noncollagen protein (NCP) was determined using repurified bacterial collagenase. Progesterone caused a dose dependent inhibition of the labeling of CDP at concentrations of 3×10−7 M to 10−5 M after 96 h of culture. A smaller inhibitory effect was observed on NCP. The inhibitory effect was slow in onset and persisted when bones were incubated for 48 h with progesterone and then transferred to control medium for 48 h. Progesterone also inhibited the incorporation of3H-thymidine and3H-uridine into fetal rat calvaria. After 24 h of culture, 17β estradiol and testosterone had no effects on the labeling of CDP and NCP. After 96 h, 17β estradiol had a small and inconsistent stimulatory effect on the labeling of CDP but testosterone had no effect. Neither hormone altered the inhibitory effects of parathyroid hormone, cortisol and progesterone. Dihydrotestosterone and dehydroepiandrosterone had no effects after 24 h and 96 h of culture. 17β estradiol, testosterone and dihydrotestosterone did not affect the incorporation of3H-uridine or3H-thymidine into fetal rat calvaria. Our studies indicate that progesterone is an inhibitor of bone collagen synthesis and estrogens and androgens are not major regulators of bone formation in vitro.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02010758
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...