Library

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
  • Electronic Resource  (13)
  • Life and Medical Sciences  (5)
  • Biochemistry and Biotechnology  (2)
  • Cholesterol  (2)
  • Inulin  (2)
  • Liesegang rings  (2)
Source
Material
  • Electronic Resource  (13)
Years
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Enzyme-based fiber-optic device for the determination of total and free cholesterol
    Amsterdam : Elsevier
    Analytica Chimica Acta 256 (1992), S. 263-268 
    Details
    ISSN: 0003-2670
    Keywords: Biosensor ; Blood ; Cholesterol ; Enzyme reactor ; Fibre-optic sensor ; Serum
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0003-2670(92)85353-8
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Flow-injection analysis for total cholesterol with photometric detection
    Amsterdam : Elsevier
    Analytica Chimica Acta 287 (1994), S. 59-64 
    Details
    ISSN: 0003-2670
    Keywords: Cholesterol ; Enzymatic methods ; Flow injection ; Serum ; Spectrophotometry
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0003-2670(94)85101-8
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Pulmonary uptake of bupivacaine in isolated perfused rat lung (1995)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 351 (1995), S. 99-106 
    Details
    ISSN: 1432-1912
    Keywords: Lung perfusion ; Bupivacaine ; Fluorochrome-labeled capillaries ; First-pass retention ; Inulin ; Tritium-labeled water
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The ability of rat lung to remove the local anaesthetic drug bupivacaine from the blood was studied in isolated organs which were perfused either in an open (single-pass mode) or in a closed system (recirculating medium). Isolated perfused rat lungs exhibited a very low capacity to metabolize bupivacaine within 3 h during which the drug circulated continuously through the organ. The clearance values differed only by 0.2 ml/min from the control parameters in sham perfusions. The calculated extraction ratio was 0.2% and the elimination half-life was about 210 min. The volume of distribution of bupivacaine was 133 ml which remarkably surmounted the reference values obtained for sham perfusions. The distribution of bupivacaine into the pulmonary tissue was investigated applying the multiple indicator dilution technique to isolated lungs perfused in the single-pass mode. The mean elimination time of model compounds for distribution into the intravascular space, 14C-inulin, and the total water space, 3H-water, were 68 and 75 s at a flow rate of 6 ml/min. The volume of distribution was 5.9 ml for inulin and 6.5 ml for water. The mean transit time for concomitantly injected bupivacaine was 221 s and the volume of distribution was 14.4 ml. The respective parameters of sham perfusions performed without an isolated organ were substantially lower, i.e. mean elimination time 50, 50 and 61 s and distribution volume 4.9, 5.0 and 6.1 ml for inulin, water and bupivacaine. The volume of distribution during single-pass contact of bupivacaine to lung was not substantially influenced by an increase of the flow rate from 6 to 9 and 12 ml/min whereas the mean transit time dropped from 221 to 121 and 108 s, respectively. These results support the assumption that bupivacaine is extensively retained by the pulmonary tissue and that elimination of bupivacaine by metabolism can be neglegted for lung. The hemodynamic parameters of bronchiolar perfusion in the artificially perfused lung were determined using two fluorochrome-labeled macromolecular proteins, i.e. fluorescein-isothiocyanate (FITC)- and lissamine-rhodamine-B 200 (RB 200)-labeled globulin. After 10 min of perfusion at a flow rate of 12 ml/min in the closed system an area of 10.8070 of the peribronchiolar tissue area contained the dye-label FITC. A very similar index (10.1%) of dye-coloured capillaries was obtained when the lungs of anaesthetized rats were examined 10 min after intravenous injection of the fluorochrome into the pulmonary artery in vivo. In isolated perfused rat lungs receiving both FITC and RB 200 59.5% of FITC-labeled capillaries were reached by the second fluorochrome within 2 s. This fraction accounted for 93.3% after 10 s of circulation time. This proves that isolated rat lungs were well perfused in vitro.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00169070
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Morphological instabilities in pattern formation by precipitation and crystallization processes (1996)
    Springer
    International journal of earth sciences 85 (1996), S. 19-28 
    Details
    ISSN: 1437-3262
    Keywords: Anastomoses ; Crystal zoning ; Snow bands ; Liesegang rings ; Ostwald ripening ; Self organization ; Siderite ; Supersaturation theory ; Zebra rock
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract Morphological instabilities in periodic patterns occurring both in precipitation and crystallization processes (Liesegang rings and crystal zoning) are investigated and compared with similar patterns in geological samples (zebra rocks and mud bands in snow sediments). In classical Liesegang systems, undisturbed parallel or concentric precipitation bands are emanated from even or concentric diffusion sources in homogeneous diffusion matrices of gelatine or other gels. In the case of superposing diffusion sources, sources with undulatory curvatures or local diffusion barriers there may occur several types of instabilities within the sequence of regular patterns: (a) gaps within the bands forming radial alleys free of precipitate, (b) transition from broken bands to speckled patterns and (c) apparent branching of bands linked together by so-called anastomoses. Calculations with a competitive particle growth (CPG) model show that lateral instabilities in Liesegang bands (gaps and radial alleys of gaps) are the result of Ostwald ripening effects taking place after precipitation. Apparent branching of bands or formation of anastomoses can be simulated with a prenucleation model according to Ostwald's supersaturation theory. Similar irregularities can be observed in zebra rocks (e.g. banded siderite) whose bandings are commonly explained by sequential sedimentation processes. A very different mechanism is assumed to be responsible for the origin of mud bands in snow sediments. An initially homogeneous distribution of intrinsic mud in snow sediments can be arranged into parallel bands according to a crystal zoning mechanism which is based on repeated thawing and freezing of the snow sediment due to the daily alternation of sun and darkness.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00192056
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Pulmonary uptake of bupivacaine in isolated perfused rat lung (1994)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 351 (1994), S. 99-106 
    Details
    ISSN: 1432-1912
    Keywords: Key words Lung perfusion ; Bupivacaine ; Fluorochrome-labeled capillaries ; First-pass retention ; Inulin ; Tritium-labeled water
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The ability of rat lung to remove the local anaesthetic drug bupivacaine from the blood was studied in isolated organs which were perfused either in an open (single-pass mode) or in a closed system (recirculating medium). Isolated perfused rat lungs exhibited a very low capacity to metabolize bupivacaine within 3 h during which the drug circulated continuously through the organ. The clearance values differed only by 0.2 ml/min from the control parameters in sham perfusions. The calculated extraction ratio was 0.2% and the elimination half-life was about 210 min. The volume of distribution of bupivacaine was 133 ml which remarkably surmounted the reference values obtained for sham perfusions. The distribution of bupivacaine into the pulmonary tissue was investigated applying the multiple indicator dilution technique to isolated lungs perfused in the single-pass mode. The mean elimination time of model compounds for distribution into the intravascular space, 14C-inulin, and the total water space, 3H-water, were 68 and 75 s at a flow rate of 6 ml/min. The volume of distribution was 5.9 ml for inulin and 6.5 ml for water. The mean transit time for concomitantly injected bupivacaine was 221 s and the volume of distribution was 14.4 ml. The respective parameters of sham perfusions performed without an isolated organ were substantially lower, i.e. mean elimination time 50, 50 and 61 s and distribution volume 4.9, 5.0 and 6.1 ml for inulin, water and bupivacaine. The volume of distribution during single-pass contact of bupivacaine to lung was not substantially influenced by an increase of the flow rate from 6 to 9 and 12 ml/min whereas the mean transit time dropped from 221 to 121 and 108 s, respectively. These results support the assumption that bupivacaine is extensively retained by the pulmonary tissue and that elimination of bupivacaine by metabolism can be neglegted for lung. The hemodynamic parameters of bronchiolar perfusion in the artificially perfused lung were determined using two fluorochrome-labeled macromolecular proteins, i.e. fluorescein-isothiocyanate (FITC)- and lissamine-rhodamine-B 200 (RB 200)-labeled globulin. After 10 min of perfusion at a flow rate of 12 ml/min in the closed system an area of 10.8% of the peribronchiolar tissue area contained the dye-label FITC. A very similar index (10.1%) of dye-coloured capillaries was obtained when the lungs of anaesthetized rats were examined 10 min after intravenous injection of the fluorochrome into the pulmonary artery in vivo. In isolated perfused rat lungs receiving both FITC and RB 200 59.5% of FITC-labeled capillaries were reached by the second fluorochrome within 2 s. This fraction accounted for 93.3% after 10 s of circulation time. This proves that isolated rat lungs were well perfused in vitro.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00169070
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Morphological instabilities in pattern formation by precipitation and crystallization processes (1996)
    Springer
    Geologische Rundschau 85 (1996), S. 19-28 
    Details
    ISSN: 0016-7835
    Keywords: Key words Anastomoses ; Crystal zoning ; Snow bands ; Liesegang rings ; Ostwald ripening ; Self organization ; Siderite ; Supersaturation theory ; Zebra rock
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract  Morphological instabilities in periodic patterns occurring both in precipitation and crystallization processes (Liesegang rings and crystal zoning) are investigated and compared with similar patterns in geological samples (zebra rocks and mud bands in snow sediments). In classical Liesegang systems, undisturbed parallel or concentric precipitation bands are emanated from even or concentric diffusion sources in homogeneous diffusion matrices of gelatine or other gels. In the case of superposing diffusion sources, sources with undulatory curvatures or local diffusion barriers there may occur several types of instabilities within the sequence of regular patterns: (a) gaps within the bands forming radial alleys free of precipitate, (b) transition from broken bands to speckled patterns and (c) apparent branching of bands linked together by so-called anastomoses. Calculations with a competitive particle growth (CPG) model show that lateral instabilities in Liesegang bands (gaps and radial alleys of gaps) are the result of Ostwald ripening effects taking place after precipitation. Apparent branching of bands or formation of anastomoses can be simulated with a prenucleation model according to Ostwald's supersaturation theory. Similar irregularities can be observed in zebra rocks (e.g. banded siderite) whose bandings are commonly explained by sequential sedimentation processes. A very different mechanism is assumed to be responsible for the origin of mud bands in snow sediments. An initially homogeneous distribution of intrinsic mud in snow sediments can be arranged into parallel bands according to a crystal zoning mechanism which is based on repeated thawing and freezing of the snow sediment due to the daily alternation of sun and darkness.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00192056
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Filament formation and ethanol production by Zymomonas mobilis in adsorbed cell bioreactors (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 27 (1985), S. 626-631 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Zymomonas mobilis immobilized on microporous ion exchange resins has previously been shown to allow the attainment of high ethanol productivities in packed-bed bioreactors. The formation of bacterial filaments after several days of continuous operation, however, had resulted in excessive pressure increases across the reactor bed. The present work examines techniques for controlling filament formation by Z. mobilis in two reactor sizes (161 mL and 7.85 L) and a feed glucose concentration of 100 g/L. By controlling the fermentation temperature at 20-25°C it has been possible to eliminate filament formation by Z. mobilis and to operate the larger bioreactor for 232 h with an ethanol productivity of 50 g/L h (based on total reactor volume). The rate of ethanol production has been shown to be very sensitive to temperature in the range 20-30°C, and it is likely that slightly higher temperatures than those used in this study will improve ethanol productivity while still permitting long-term operation.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260270512
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Morphogenesis of precursor subpopulations of chicken limb mesenchyme in three dimensional collagen gel culture (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 226 (1990), S. 91-107 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Although homogeneous in appearance, several lines of evidence suggest early (stage 17 - 19) limb mesenchymal cells are committed to particular cell lineages, e.g., myogenic or chondrogenic. However, subsequent expression of cell or tissue phenotype in the developing limb does not occur in a randomized process but rather in a spatially specific pattern. The potential regulatory mechanisms controlling the “patterned” expression of tissue phenotype in the limb have not been resolved. The purpose of this study was to determine if, prior to the formation of an apical ectodermal ridge, nondissociated limb mesenchyme has inherent morphogenetic potential to form nonrandomized patterns of tissue organization. The hypotheses to be tested were that, if provided a spatially permissive culture environment, (1) mesenchymal cells committed to a particular lineage would segregate into precursor (sub)populations prior to overt expression of phenotype and (2) the ultimate expression of a tissue phenotype may be regulated, in part, by histogenic interactions between the precursor cell groups. For these studies, mesoblasts (intact mesenchyme minus ectoderm) from stage 17 - 19 hindlimb buds were explanted intact to the surface of a 1 - 3 mm thick hydrated lattice of repolymerized type I collagen and incubated for 2 - 11 days. Examination of cultures at variable intervals revealed three distinct temporal sequences (periods) which were arbitrarily termed early morphogenesis (0 - 3 days), cytodifferentiation (3 - 5.5 days), and primitive tissue formation (5.5 - 11 days) based on similarities to in situ limb development. By the end of the first period, the mesenchymal cells had sorted into three distinct precursor populations: (1) an epithelial-like outgrowth of premyogenic and prefibrogenic cells at the surface of the gel lattice (termed the “surface subset”) which circumscribed, (2) a centrally positioned prechondrogenic condensate (“central subset”), and overlaid (3) a dispersed, population of free cells that invaded the collagen lattice (“seeded subset”). Subsequent cytodifferentiation led to the appearance of multinucleated myotubes within the surface subset and chondrification of the central subset. Cells of the seeded subset remained dispersed within the collagen lattice. Primitive histogenic events were initiated during the final period of development including (1) at sites where surface cells established boundaries with the central subset, collectives or “bundles” of variable sized myotubes were formed which became partially ensheathed by the attenuated processes of fibroblastlike cells; and (2) a secondary site of chondrogenic activity was initiated within the gel lattice at the boundary between the central and seeded cell populations. Transformation of seeded fibroblasts into chondroblasts accompanied expansion of the secondary chondrogenic element within the gel lattice. Remaining cells of the seeded population which did not become incorporated (transformed) into the secondary site of chondrogenesis persisted as a dense stratified network of fibrous connective tissue. Removing the central subset after 2 days of culture inhibited the transformation of seeded fibroblasts into chondrogenic cells.These findings indicate that intact limb mesenchyme prior to the formation of a mature apical ridge and in the absence of dorsal/ventral ectoderm has the endogenous potential to segregate, cytodifferentiate, and interact to intiate tissue formation similar to that seen in the intact limb.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092260111
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Multiple glycoproteins localize to a particulate form of extracellular matrix in regions of the embryonic heart where endothelial cells transform into mesenchyme (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 232 (1992), S. 285-292 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Cells derived from an epithelial-mesenchymal transformation within the atrioventricular canal and outflow tract are involved in the partitioning of the early embryonic heart into a four-chambered organ. This transformation process has been shown to proceed from an inductive interaction between the myocardium and competent, target endothelial cells within these regions of the heart. Interestingly, immunohistochemistry revealed the presence of fibronectinpositive particulates within the matrix of mesenchyme-forming regions (Mjaatvedt et al., 1987). This particulate matrix is extractable by EDTA and can elicit the epithelial-mesenchymal transformation in culture (Mjaatvedt and Markwald, 1989). Analysis of EDTA extracts of embryonic heart tissue revealed the presence of fibronectin and about 40 unidentified proteins, 6 of which appeared to be enriched in the biologically active 100,000g pellet fraction (Mjaatvedt and Markwald, 1989). Based on these and other data we have proposed that the particulate matrix is composed of a multicomponent complex of fibronectin and one or more of the low-molecular-weight proteins in this pellet. The purpose of the present study was to begin a biochemical characterization of the nonfibronectin proteins thought to be present in the matrix particulates. Given that many matrix constituents are glycoproteins, lectins were used to initially characterize the particulate constituents. Of the lectins tested, soybean agglutinin (SBA) was found to be specific only for matrix particulates. Histochemical analyses showed that SBA and antibodies against fibronectin colocalized regionally and temporally to the same matrix particulates in embryonic heart tissue. SBA-agarose affinity chromatography resulted in the isolation of two major (56 and 69 kDa) and six minor (28, 46, 50, 53, 126, 220 kDa) proteins from EDTA extractable heart matrix. Temporal lectin histochemical studies indicate that SBA-positive particulates are present in the matrix prior to mesenchyme formation, but are absent shortly after the transformation event. These observations support our hypothesis that one or more of these SBA-positive glycoproteins participate in the endothelial-mesenchymal transformation of cardiac endothelium.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092320213
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Identification of transferrin as one of multiple EDTA-extractable extracellular proteins involved in early chick heart morphogenesis (1994)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 54 (1994), S. 207-218 
    Details
    ISSN: 0730-2312
    Keywords: EDTA soluble proteins ; chick embryo ; purification ; epithelial-mesenchymal interactions ; transferrin ; conalbumin ; extracellular matrix ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: It was demonstrated previously that a polyclonal antibody (ES1) raised against EDTA extractable proteins from embryonic chicken heart blocks cardiac endothelial-mesenchymal transformation in a culture bioassay and stains extracellular matrix at sites of embryonic inductive interactions, e.g., developing heart, limb buds, and neural crest forming region (Krug et al., 1987, Dev Biol 120:348-355; Mjaatvedt et al., 1991, Dev Biol 145:219-230). In the present study, by using an antiserum (ES3) to a similar immunogen, we affinity purified four major EDTA-soluble proteins. These proteins migrated as 27, 44, 63, and 70 kD molecules under reduced conditions and 27, 41, 52, and 59 kD under nonreduced conditions, respectively, on SDS-PAGE. Based on several criteria, the protein migrating at 70/59 kD (reduced/nonreduced) was indistinguishable from chicken transferrin (conalbumin): (1) amino acid sequencing showed that eight N-terminal residues were identical to those of chicken transferrin, (2) acid hydrolysates of both proteins had nearly identical compositions, (3) the protein co-migrated exactly with chicken transferrin under both reduced and nonreduced conditions, and (4) ES3 IgG recognized both the 70/59 kD protein and chicken transferrin by western blot analysis of nonreduced samples, but not with reduced samples. Immunohistochemistry of chicken embryonic heart with antibodies against transferrin demonstrated that anti-transferrin immunoreactivity is present in myocardium but absent in cardiac endothelium before the initiation of cardiac endothelial-mesenchymal formation. However, both cardiac endothelium and migrating mesenchymal cells became immunoreactive with anti-transferrin at the time transformation occurred. These findings suggest a possible involvement of transferrin in the inductive process of cardiac endothelial-mesenchymal transformation.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240540209
    Library Location Call Number Volume/Issue/Year 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...