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  • 1
    ISSN: 1432-0827
    Keywords: Osteoporosis ; Immobilization ; Rats ; Vitamin D
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The therapeutic effects of vitamin D analogs, 1,24(R)-dihydroxycholecalciferol [1,24(R)(OH)2D3], 1,24(S)-dihydroxycholecalciferol [1,24(S)(OH)2D3], and 1,25-dihydroxycholecalciferol [1,25(OH)2D3] on immobilization osteoporosis were studied in rats. The right hind limb was immobilized through application of a plaster cast following the section of the sciatic nerve. The left hind limb was intact. Vitamin D analogs were orally administered for 6 weeks at dose levels of 0.02 and 0.10µg/kg/day, respectively. The mean lengths of the immobilized femurs were not significantly different from those of the intact femurs in all the experimental groups. In the immobilized femur of animals treated with 1,24(R)(OH)2D3, 0.10µg/kg, dry and ash weights were heavier and calcium and phosphorus contents greater than those in the nontreated group. Furthermore, the amount of calcified bone mass and the cortical thickness of the femurs of the immobilized limb in 1,24(R)(OH)2D3-treated animals were greater than those in the nontreated animals. Treatment with 1,25(OH)2D3 at 0.10µg/kg caused an increase of the bone mass in both immobilized and intact femurs when compared with those of the control group. It was concluded that the administration of 1,24(R)(OH)2D3 diminished the effect of immobilization in the development of osteoporosis without any side effects.
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  • 2
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    Calcified tissue international 10 (1972), S. 82-90 
    ISSN: 1432-0827
    Keywords: Calcium ; Phosphate ; Precipitation ; Kinetics ; Chemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé La cinétique de la formation et de la transformation des précipités de phosphate de calcium, obtenus en mélangeant de volumes égaux de solutions à 6×10−3 M de calcium total et/ou phosphate total est étudiée à 25°C. Les solutions de phosphate sont préajustées à un pH de 7.4. Les changements de pH et de turbidité des solutions sont suivis simultanément en fonction du temps. Les précipités sont isolés à des intervalles de temps variables et caractérisés par diverses méthodes physico-chimiques. Initialement un précipité avec un rapport molaire Ca/P de 1.5, amorphe aux rayons X et en diffraction électronique, est formé. Le spectre IR indique la présence de PO 4 3− et de HPO 4 2− . Après une période métastable, on observe la précipitation d'un matériel cristallin dans ou sur la phase amorphe. Vingt quatre heures après préparation de l'échantillon les précipités présentent surtout les caractères du phosphate octocalcique.
    Abstract: Zusammenfassung Die Kinetik der Bildung und Transformation von Calciumphosphat-Niederschlägen wurde bei 25°C untersucht. Es wurden dazu gleiche Volumen von Lösungen gemischt, bei einer Konzentration von 6×10−3M totales Calcium und/oder totales Phosphat. Die Phosphatlösungen wurden zuerst auf pH 7,4 eingestellt. Veränderungen des pH und Trübung der Lösungen wurden gleichzeitig als eine Funktion der Zeit aufgezeichnet. Niederschläge wurden in verschiedenen Zeitintervallen isoliert und mit verschiedenen physiko-chemischen Methoden charakterisiert. Am Anfang wurde ein Niederschlag mit einem molaren Ca/P-Verhältnis von 1,5, im Röntgenbild und in der Elektronendiffraktion amorph, gebildet. Infrarotspektren deuteten die Anwesenheit von PO 4 3− - und HPO 4 2− -Ionen an. Nach einer metastabilen Periode erfolgte ein Niederschlag aus kristallinem Material innerhalb oder auf der amorphen Substanz. 24 Std nach der Herstellung der Proben zeigten die Niederschläge in der Hauptsache die Charakteristiken von Octocalciumphosphat.
    Notes: Abstract The kinetics of the formation and transformation of calcium phosphate precipitates obtained by mixing equal volumes of solutions, 6×10−3 M in total calcium and/or total phosphate was investigated at 25°. The phosphate solutions were preadjusted to pH 7.4. Changes of the pH and turbidity of the solutions were followed simultaneously as a function of time. Precipitates were isolated at various time intervals and characterized by different physicochemical methods. Initially a precipitate with a molar Ca/P ratio of 1.5, amorphous to X-ray and electron diffraction was formed. IR spectra indicated the presence of PO 4 3− and HPO 4 2− ions. After a period of metastability, precipitation of a crystalline material within or upon the amorphous matter occurred. Twenty four hours after sample preparation the precipitates showed mainly the characteristics of octacalcium phosphate.
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  • 3
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    Calcified tissue international 16 (1974), S. 145-152 
    ISSN: 1432-0827
    Keywords: EHDP ; Bone ; Chemistry ; Serum ; Rabbits
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract The effects of disodium ethane-1-hydroxy-1,1-diphosphonate (EHDP) on bone and serum chemistry were investigated in adult rabbits. EHDP was administered by subcutaneous injection at doses of 0.25, 2.5 and 10 mg/kg body weight/day for of 28 days. Blood samples were obtained weekly from each rabbit and serum levels of total calcium, ionized calcium, inorganic phosphate and alkaline phosphatase were determined. At the end of the treatment period all rabbits were sacrificed and the tibiae removed for chemical analysis and histological evaluation. The effect of EHDP administration on serum chemistry was both dose- and time-related. The highest of the three doses, 10 mg/kg/day, resulted in a time-related decrease in total serum calcium. This dose also caused a rapid but transient reduction in serum ionized calcium. The effect of EHDP on serum inorganic phosphate was biphasic. Administration of 2.5 mg/kg/day resulted in a time-related elevation in this parameter, whereas the 10 mg/kg/day dose resulted in a time-related hypophosphatemic response. There were no significant drug-related changes in tibial fat-free dry weight, ash weight, total calcium or total phosphorus values. However, administration of 2.5 and 10 mg/kg/day EHDP resulted in increased osteoid tissue as measured histologically. These results are compared with data from other EHDP studies, and discussed in relation to the maturity and growth-state of the experimental animals.
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  • 4
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    Calcified tissue international 34 (1982), S. 547-552 
    ISSN: 1432-0827
    Keywords: Rats ; Osteoporosis ; Anorganic ; Femur ; Castrate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The study describes the SEM appearances of endosteal and periosteal surfaces of anorganic femoral diaphyses from 16-month-old normal and castrate male rats. Different types of surfaces could be recognized in both groups. Percentage areas occupied by each surface type were analyzed with a Ladd Data Analyzing Digitizer. Endosteal surfaces were composed of significantly more (P〈0.05) incompletely mineralized, forming surface and significantly less (P〈0.05) completely mineralized, resting surface in castrates than in controls. Both endosteal and periosteal surfaces from experimental bone demonstrated significantly more (P〈0.05) osteoblast lucunae than did control surfaces, and vascular canal entrances were significantly wider (P〈0.001) on castrate endosteal surfaces than on control endosteal surfaces. There was a greater proportion of small nodule forming surface/large nodule forming surface in castrate endosteal bone than in control, and a greater proportion prolonged resting surface/fibrous resting surface in control periosteal bone than in castrate. The results indicate that, when viewed in the SEM, anorganic endosteal and periosteal bone surfaces from femoral diaphyses of old castrate male rats demonstrate appearances characteristic of changes in bone turnover that occur with osteoporosis.
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  • 5
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    Calcified tissue international 9 (1972), S. 17-27 
    ISSN: 1432-0827
    Keywords: Periosteal Hyperplasia ; Osteomyelosclerosis ; Magnesium ; Parathyroid ; Rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Un régime contenant 0.8 à 2 mg de Mg pour 100 g, administré à des rats jeunes ou adultes pendant 18 à 21 jours, provoque une croissance généralisée d'os médullaire (ostéomyélosclérose), ainsi que des tumeurs périostées de type desmoide, au niveau de la linea aspera du fémur. Ces modifications s'accompagnent d'une décroissance du magnésium osseux de 52 à 71%, déterminée par spectrophotométrie d'absorption atomique. Au niveau des tumeurs périostées, la parathyroidectomie favorise la formation de cartilage. L'administration d'extrait parathyroidien inhibe la formation de cartilage en faveur de la formation de tissue fibreux et d'os. L'adjonction de magnésium au régime restitue rapidement l'apparence normale des tissus.
    Abstract: Zusammenfassung Eine Nahrung mit 0,8–2 mg Mg per 100 g wurde jungen oder ausgewachsenen Ratten während 18–21 Tagen verfüttert; sie verursachte ein generalisiertes medulläres Knochenwachstum (Osteomyelosklerose) und ebenso desmoidartige Tumoren, des Periosts an der femoralen Linea aspera. Diese Veränderungen waren von einer Abnahme von 52–71% der Magnesium-Konzentration im Knochen begleitet (Bestimmung am Atomabsorptions-Spektrophotometer). Bei Tumoren des Periosts wurde die Knorpelbildung durch Parathyreoidektomie begünstigt. Durch Verabreichung von Parathyreoidea-Extrakt wurde die Knorpelbildung gehemmt und an deren Stell fibröses Gewebe und Knochen gebildet. Wurde der Nahrung Magnesium zugesetzt, so bekamen die Gewebe rasch ein normales Aussehen.
    Notes: Abstract A diet containing from 0.8 to 2 mg Mg/100 g, fed to young or adult rats for 18 to 21 days produced generalized medullary bone growth (osteomyelosclerosis) and also periosteal tumours of the desmoid type, at the femoral linea aspera. These changes were accompanied by decreases in bone magnesium concentration of 52 to 71% as measured by atomic absorption spectrophotometry. In the periosteal tumours, parathyroidectomy favoured cartilage formation. The administration of parathyroid extract inhibited cartilage formation in favour of fibrous tissue and bone production. The addition of magnesium to the diet quickly restored the normal appearance of the tissues.
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  • 6
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    Journal of molecular evolution 15 (1980), S. 79-101 
    ISSN: 1432-1432
    Keywords: Molecules ; Interstellar ; Chemistry ; Isotopes ; Solar system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The study of interstellar molecules broadly includes two areas of interest. One area uses the unique ability of molecules to act as probes of the physical conditions in the cold, dense, visually opaque component of the interstellar medium. The physical properties of this and other components of the interstellar medium are summarized. The other area deals with the chemistry of interstellar molecules, recent aspects of which are emphasized in this review. Gas-phase chemistry, shock chemistry, and grain surface chemistry are discussed in the context of recent observations. No present observations suggest that surface reactions are relevant, but neither can they be ruled out. Ion-molecule reactions are clearly operative, at least for the simpler species. Chemical isotope fractionation is reviewed, andd it is concluded that the complexities of the chemistry allow no cosmological conclusions to be drawn from observations of deuterium in interstellar molecules, while the presence of13C in interstellar molecules permits an estimate of the12C/13C ratio which is consistent with the current concepts of the nucleosynthesis history of the Galaxy. Possible connections between interstellar molecules and the early molecular history of the solar system are discussed.
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  • 7
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    Mycopathologia 121 (1993), S. 65-75 
    ISSN: 1573-0832
    Keywords: Bones ; Candida albicans ; Experimental arthritis ; Radiography ; Rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Sprague-Dawley rats were inoculated intravenously (i.v.) withCandida albicans, and limb joints showing signs ofCandida-induced arthritis were subjected to radiographic and histologic examination. New bone formation and bone resorption were morbidly enhanced in bones sampled from the arthritic joints. Sparsely distributed needle-shaped calcified deposits began to be formed on bony surfaces in parallel with the onset of joint swelling. The calcified deposits gradually became denser and then covered the bony surfaces almost entirely, giving rise to an exostosis-like profile. In addition to the new bone formation, bone resorption was also observed in regions adjacent to the sites of new bone formation, and punched-out bone lesions were produced. Eventually, severe deformation of joint bones due to new bone formation and bone resorption was evident. Reflecting these unusual radiographic changes, abundant osteoblasts and osteoclasts were demonstrated histologically in the bones. On the basis of these results, possible mechanisms for the induction of arthritis byCandida infection are discussed.
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  • 8
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    Pure and applied geophysics 118 (1980), S. 128-151 
    ISSN: 1420-9136
    Keywords: Galactic cosmic rays ; Solar proton events ; Particle precipitation ; Chemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract An assessment is made of the relative contribution of certain classes of energetic particle precipitation to the chemical composition of the middle atmosphere with emphasis placed on the production of odd nitrogen and odd hydrogen species and their subsequent role in the catalytic removal of ozone. Galactic cosmic radiation is an important source of odd nitrogen in the lower stratosphere but since the peak energy deposition occurs below the region where catalytic removal of O3 is most effective, it is questionable whether this mechanism is important in the overall terrestrial ozone budget. The precipitation of energetic solar protons can periodically produce dramatic enhancement in upper stratospheric NO. The long residence time of NO in this region of the atmosphere, where catalytic interaction with O3 is also most effective, mandates that this mechanism be included in future modelling of the global distribution of O3. Throughout the mesosphere the precipitation of energetic electrons from the outer radiation belt (60°≲Λ≲70°) can sporadically act as a major local source of odd hydrogen and odd nitrogen leading to observable O3 depletion. Future satellite studies should be directed at simultaneously measuring the precipitation flux and the concomitant atmosphere modification, and these results should be employed to develop more sophisticated models of this important coupling.
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  • 9
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    Calcified tissue international 14 (1974), S. 3-14 
    ISSN: 1432-0827
    Keywords: Hydroxyapatite ; Mineral ; Phase ; Chemistry ; Synthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Des diagrammes de phase d'équilibre ont été déterminés pour le système CaO-P2O5-H2O en utilisant des techniques de synthèse hydrothermique au cours de variatio nsde température allant de 300–600° et 2 Kb H2O de pression. De l'hydroxyapatite bien cristallisé a été synthétisé et caractérisé. De faibles variations de paramètres de la maille cristalline, liées à la température de synthèse et composition globale du matériel initial, ont été déterminées. Des conditions chimiques précises sont nécessaires pour obtenir de l'apatite, en tant que seule phase solide en équilibre dans la solution. Les résultats de diagramme de phase d'équilibre sont comparés avec ceux obtenus dans des milieux synthétiques.
    Abstract: Zusammenfassung Es wurden Gleichgewichts-Phasendiagramme für das System CaO-P2O5-H2O bestimmt, indem hydrothermale Synthese-Techniken im Temperaturbereich von 300–600° und bei einem Druck von 2 Kb H2O verwendet wurden. Es wurde gut-kristallisiertes Hydroxyapatit erzeugt und charakterisiert. Es wurden geringe Unterschiede in den Parametern der Zelleinheiten festgestellt, welche von der angewandten Temperatur und der Zusammensetzung des Startmaterials abhingen. Es waren genaue chemische Bedingungen nötig, um Apatit als die einzige feste Phase im Gleichgewicht mit der Lösung zu erhalten. Die Resultate der Gleichgewichts-Phasendiagramme werden mit früheren Untersuchungen mit der Synthesetechnik verglichen.
    Notes: Abstract Equilibrium phase diagrams have been determined for the system CaO-P2O5-H2 using hydrothermal synthesis techniques in the temperature range 300–600° and 2 Kb H2O pressure. Well-crystallized hydroxyapatite has been produced and characterized. Small variations in unit cell parameters dependent on temperature of synthesis and bulk composition of the starting materials have been determined. Precise chemical conditions were required to obtain apatite as the only solid phase in equilibrium with solution. Equilibrium phase diagram results are compared with previous synthetic investigations.
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  • 10
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    Calcified tissue international 50 (1992), S. 80-87 
    ISSN: 1432-0827
    Keywords: PGE2 ; Ovariectomy ; Rats ; New bone trabeculae ; Positive balance ; Accelerated bone turnover
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Serum chemistry and bone morphometry of the proximal tibial metaphysis were performed in 3-month-old double fluorescent-labeled, female Sprague-Dawley rats subjected to bilateral ovariectomy or sham surgery for 4 months prior to treatment with 0, 0.3, 1, 3, or 6 mg of prostaglandin E2 (PGE2)/kg/day subcutaneously for 30 days. The 4-month postovariectomized rats possessed an osteopenic proximal tibial metaphysis with 7% trabecular area compared with controls (19%). PGE2 treatment elevated osteocalcin levels and augmented proximal tibial metaphyseal bone area in ovariectomized and sham-operated rats. Osteopenic, ovariectomized rats treated with 6 mg PGE2/kg/day for 30 days restored bone area to levels of agematched sham-operated rats. Morphometric analyses showed increased woven and lamellar bone area, fluorescent-labeled perimeter (osteoblastic recruitment), mineral apposition rate (osteoblastic activity), bone formation rate (BFR/BV), and longitudinal bone growth. These dramatic bone changes were all significantly increased at the doseresponse manner. This study showed that in vivo PGE2 is a powerful activator of bone remodeling, it increases both bone resorption and bone formation, and produces an anabolic effect by shifting bone balance to the positive direction. Furthermore, PGE2-induced augmentation of metaphyseal bone area in ovariectomized rats was at least two times greater than in sham-operated rats.
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  • 11
    ISSN: 1432-0827
    Keywords: Insulinlike growth factor I ; Interleukin 1 ; Oophorectomy ; Estrogen ; Rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Oophorectomy (OOX) has been known to increase bone turnover, but its precise mechanism is not fully understood. In order to further investigate the mechanism, we determined insulinlike growth factor I (IGF-I) concentrations in serum and bone tissue and interleukin 1 (IL-1) release from spleen macrophages in oophorectomized rats because it has been demonstrated that IGF-I stimulates bone formation and IL-1 stimulates bone resorption. Female 8-week-old Wistar rats were divided into four groups: (1) control, (2) OOX, (3) OOX given estradiol, and (4) control given estradiol. Ten μg/kg of 17β-estradiol was given daily by subcutaneous injection. After 5 weeks of treatment, IGF-I concentrations in the extract from right femur and in serum were determined by specific radioimmunoassay. IL-1 activity released from lipopolysaccharide (LPS)-stimulated spleen macrophages was determined by bioassay. IGF-I contents in the femur and IGF-I concentrations in serum in oophorectomized rats were significantly higher than those in control rats. Treatment by estradiol inhibited the increase in IGF-I concentrations both in femur and in serum. IL-1 release from LPS-stimulated spleen macrophages in oophorectomized rats was increased, and treatment by estradiol also inhibited the stimulated IL-1 release. The ash weights and the calcium contents of left femur in oophorectomized rats were lower than those in control rats. These results suggest that both IGF-I and IL-1 may be involved in the mechanism of the regulation of bone turnover in oophorectomized rats.
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  • 12
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    Calcified tissue international 7 (1971), S. 150-162 
    ISSN: 1432-0827
    Keywords: Uranium ; Bone ; Distribution ; Fission ; Chemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Une concentration moyenne de 2.4×10−8 g U/g de cendre a été obtenue à partir de l'os humain normal. La microdistribution de l'uranium dans l'os indique que cet élément est surtout limité à surface de l'endoste et, en particulier, aux surfaces de l'os lamellaire et aux parois des canaux de Havers, ouverts dans l'os corticol. Cette répartition suggère que l'uranium se présente sous une forme chimique impropre à son incorporation dans l'apatite osseux: il ne semble donc pas exister une distribution diffuse significative de l'uranium dans l'os.
    Abstract: Zusammenfassung Eine mittlere Konzentration von 2,4×10−8 g Uran/g Asche wurde in normalen menschlichen Knochen gefunden. Die Feinverteilung von Uran im Knochen zeigt, daß dieses Element hauptsächlich an der endostalen Oberfläche vorkommt, insbesondere an der Oberfläche des trabeculären Knochens und an den Wänden der offenen Haversschen Kanäle im kortikalen Knochen. Diese Verteilung läßt vermuten, daß Uran in einer chemischen Form vorliegt, welche sich für den Einbau in das Knochenapatit nicht eignet. Daraus folgt, daß keine signifikante diffuse Verteilung des Urans innerhalb des Knochens vorliegt.
    Notes: Abstract A mean concentration of 2.4×10−8 g U/g ash has been obtained for normal human bone The microdistribution of uranium in bone indicates that this element is mainly restricted to endosteal surfaces; in particular the surfaces of trabecular bone and the walls of open Haversian canals in cortical bone. This distribution suggests that uranium is present in a chemical form that is not acceptable for incorporation into bone apatite and consequently there does not appear to be a significant diffuse distribution of uranium throughout bone.
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  • 13
    ISSN: 1432-0827
    Keywords: Morphology ; Glycosaminoglycans ; Cartilage ; Chemistry ; Audioradiography ; Healing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Une perte de substance ostéo-cartilagineuse, de taille limitée et identique, est réalisée chez le lapin adulte et la cicatrisation est étudiée histologiquement et par autoradiographie après marquagein vitro au35S-sulfate. Une analyse microchimique est pratiquée pour le contenu et la composition en glycosaminoglycanes. 1. Entre la première semaine et la 4ème et 8ème semaine, un tissu conjonctif non-métachromatique se différencie en un cartilage métachromatique et la quantité de sulfate de chondroitine augmente de façon significative aux dépens des glycoprotéines. 2. Jusqu'à la 4ème semaine, la perte de substance est surtout comblée par de l'os néoformé: après cette période, la région est comblée au delà de la limite de la surface articulaire. 3. Le cartilage hyalin, ressemblant morphologiquement, autoradiographiquement et chimiquement au cartilage articulaire, en ce qui concerne la distribution en glycosaminoglycanes, constitute la surface articulaire de la perte de substance comblée dans un tiers des cas après 8 semaines. Le cartilage hyalin s'observe surtout dans les régions où de l'os néoformé a comblé la cavité médullaire. 4. Dans les deux tiers des cas, après 8 semaines, les surfaces articulaires des zones comblées comportent, non seulement du cartilage, mais aussi du tissu fibreux se formant essentiellement sur les parties latérales et dans les régions, où la cavité médullaire, fliant face, à la surface articulaire, n'a pas été comblée par du tissue osseux. La fraction glycoprotéique augmente par rapport à la fraction chondroitine sulfate. 5. Dans la majorité des cas, après 20 semaines, le cartilage néoformé subit des phénomènes dégénératifs, qui se traduisent par une diminution en chondroitine sulfate.
    Abstract: Zusammenfassung Bei ausgewachsenen Kaninchen wurde ein begrenzter, standardisierter, osteochondraler Defekt hervorgerufen, und das regenerierte Gewebe wurde histologisch und autoradiographisch durch Markierung in vitro mit35S-Sulfat und durch mikrochemische Bestimmung des Gehaltes und der Zusammensetzung der Glykosaminglykane untersucht. Die wichtigsten Befunde waren: 1. Zwischen 1 und 4–8 Wochen veränderte sich nichtmetachromatisches Bindegewebe zu metachromatisch gefärbtem Knorpel, und der Anteil an Chondroitin-Sulfat nahm auf Kosten der Glykoproteine signifikant zu. 2. Bis zu 4 Wochen war der Hauptteil des defekten Gebietes mit neugebildetem Knochen gefüllt; nach dieser Zeit lag dieser Bezirk oberhalb der Verknöcherungsgrenze in Richtung der Gelenkoberfläche. 3. Nach 8 Wochen bestand die Gelenkoberfläche des defekten Gebietes in einem Drittel der Fälle aus hyalinem Knorpel, der morphologisch, autoradiographisch und chemisch dem Gelenkknorpel in Bezug auf die Verteilung von Glykosaminoglykanen glich. Hyaliner Knorpel wurde hauptsächlich an Stellen beobachtet, wo neugebildeter Knochen die Markhöhle geschlossen hatte. 3. Nach 8 Wochen bestand die Gelenkoberfläche des defekten Gebietes in einem Drittel der Fälle aus hyalinem Knorpel, der morphologisch, autoradiographisch und chemisch dem Gelenkknorpel in Bezug auf die Verteilung von Glykosaminoglykanen glich. Hyaliner Knorpel wurde hauptsächlich an Stellen beobachtet, wo neugebildeter Knochen die Markhöhle geschlossen hatte. 4. Nach 8 Wochen bestanden Teile der Gelenkoberfläche des Defektes in zwei Dritteln der Fälle nicht nur aus Knorpel, sondern auch aus fibrösem Gewebe, welches vor allem in den seitlichen Teilen des Defektes und an Stellen vorlag, wo die Markhöhle gegenüber der Gelenkoberfläche nicht mit Knochengewebe verschlossen worden war. Die Glykoproteinfraktion nahm im Vergleich zur Chondroitin-Sulfatfraktion zu. 5. Nach 20 Wochen zeigten sich in den meisten Fällen bei neugebildetem Knorpel degenerative Veränderungen, welche durch eine gewisse Abnahme des Chondroitin-Sulfats wiedergegeben wurden.
    Notes: Abstract A limited, standardized osteochondral defect was created in adult rabbits and the regenerated tissue was examined histologically and autoradiographically after labellingin vitro with35S-sulphate, and microchemically for its content and composition of glycosaminoglycans. The principal findings were: 1. Between 1 week and 4 to 8 weeks, non-metachromatic connective tissue differentiated to metachromatically stained cartilage, and the proportion of the chondroitin sulphate increased significantly at the expense of the glycoproteins. 2. Up to 4 weeks, the major part of the defect area was filled with newly formed bone; after this time, the area lay above the level of the “tidemark”, towards the articular surface. 3. Hyaline cartilage with morphological, autoradiographic and chemical resemblance to the articular cartilage in terms of the distribution of glycosaminoglycans constituted the articular surface of the defect area in one-third of the cases at observation times after 8 weeks. Hyaline cartilage was observed mainly in areas where newly formed bone had closed the medullary cavity. 4. In two-thirds of the cases, after 8 weeks, parts of the articular surface of the defect consisted not only of cartilage but also of fibrous tissue, occurring mainly in the lateral parts of the defect and in areas where the medullary cavity facing the articular surface had not been sealed by bone tissue. The glycoprotein fraction increased relative to the chondroitin sulphate fraction. 5. In most cases after 20 weeks, newly-formed cartilage underwent degenerative changes, which were reflected in some reduction of the chondroitin sulphate.
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  • 14
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    Calcified tissue international 8 (1971), S. 228-236 
    ISSN: 1432-0827
    Keywords: Skin ; Calcinosis ; Keratin ; Chemistry ; X-ray diffraction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Des études histologiques antérieures ont montré que le follicle pileux est particulièrement susceptible de se calcifier, lorsque la peau de rats hypercalcémiques est lésée. Des analyses chimiques et par diffraction aux rayons X du follicule ont confirmé ce résultat. — En se basant sur l'augmentation du calcium et du phosphore, les calcifications débutent dans le tissue folliculaire 6–12 h après une blessure d'intensité moyenne de la peau de rats, ayant reçu du dihydrotachysterol (DHT), et 24–48 h après une blessure similaire chez des rats non injectés. Les diagrammes de diffraction aux rayons X sont diffus. Trois heures après la blessure, on note une augmentation du calcium du tissu folliculaire qui ne semble pas en rapport avec le DHT qui traduit probablement une liaison de calcium plutôt qu'un dépot minéral.
    Abstract: Zusammenfassung Frühere histologische Untersuchungen haben gezeigt, daß der Haarfollikel besonders anfällig für Verkalkungen ist, wenn die Haut von hypercalcämischen Ratten verletzt wird. Dieses Resultat wurde nun durch direkte chemische Bestimmungen und Röntgendiffraktions-analysen von Follikelgewebe bestätigt. Aufgrund der erhöhten Calcium- und Phosphatwerte kann gesagt werden, daß nach einer leichten Quetschung der Haut von Ratten, die mit Dihydrotachysterol (DHT) behandelt wurden, im Haarfollikelgewebe nach 6–12 Std Mineral-ablagerungen stattfanden, wogegen Kontrollratten mit der gleichen leichten Hautverletzung diese Ablagerungen erst nach 24–48 Std zeigten. Röntgendiffraktionsanalysen ergaben ein diffuses Apatit-Muster. Innerhalb 3 Std nach der Verletzung wurde ein Anstieg des Calcium-gehaltes im Follikelgewebe beobachtet, der nicht im Zusammenhang mit der DHT-Behandlung stand, also nicht eine Mineralablagerung, sondern eher eine Bindung von Calcium widerspiegelte.
    Notes: Abstract Previous histological investigations have shown that the hair follicle is particularly susceptible to mineralization when the skin of hypercalcaemic rats is injured. Direct chemical and X-ray diffraction analyses of follicle tissue have now confirmed this finding. As judged by increases in both calcium and phosphorus, mineral deposits began to form in hair follicle tissue 6–12 h after a mild crush injury to the skin of rats dosed with dihydrotachysterol (DHT), and 24–48 h after a similar injury to the skin of non-dosed rats. X-ray diffraction gave a diffuse apatite pattern. Within 3 h of injury there was a rise in the calcium content of follicle tissue which was not related to DHT-dosing and which was probably a reflection of calcium binding rather than mineral deposition.
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  • 15
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    Calcified tissue international 8 (1971), S. 304-319 
    ISSN: 1432-0827
    Keywords: Chemistry ; Calcium ; Phosphate ; Solubility ; Computer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Un programme d'ordinateur a été mis au point pour calculer les activités ioniques du calcium et l'orthophosphate dans un grand nombre de solutions. Dans le cas de solutions synthétiques, les calculs sont vérifiés en comparant les valeurs de pH, obtenues par ordinateur, avec celles observées expérimentalement. Des essais de ce type, avec des solutions possèdant des concentrations de calcium et d'orthophosphate trouvées dans les liquides biologiques et à des valeurs de pH variant de 3.00 à 10.00, indiquent que le programme est adapté pour des applications biologiques. Le programme n'est pas effectif pour des solutions, dans les lesquelles l'ion bromure est la source principale de la force ionique, sans doute, par manque d'équation étendue de Debye-Hückel dans ces circonstances. Aucune formation de complexe de phosphate de sodium n'a été notée à des concentrations biologiques normales.
    Abstract: Zusammenfassung Es wurde ein Computer-Programm ausgearbeitet, um die Ionenaktivitäten von Calcium und Orthophosphat in einer breiten Varietät von Lösungen zu berechnen. Die Berechnungen wurden bei synthetischen Lösungen durch Vergleiche zwischen den auf diese Weise errechneten pH-Werten und den experimentell gefundenen kontrolliert. Diese Art Kontrollen mit Calcium-und Orthophosphatkonzentrationen, wie sie in biologischen Flüssigkeiten gefunden werden, und mit pH-Werten zwischen 3,0 und 10,0 wies darauf hin, daß das Programm für biologische Anwendungen geeignet war. Das Programm konnte nicht benützt werden für solche Lösungen, bei welchen hauptsächlich das Bromidion zur Einstellung der Ionenstärke verwendet wurde, vermutlich weil die erweiterte Debye-Hückel-Gleichung unter diesen Umständen nicht anwendbar ist. Die Bildung eines Natriumphosphat-Komplexes unter normalen biologischen Konzentrationen konnte nicht nachgewiesen werden.
    Notes: Abstract A computer program has been designed to calculate the ionic activities of calcium and orthophosphate in a wide variety of solutions. In the case of synthetic solutions the calculations were checked by comparing the computed pH values with those observed experimentally. Tests of this type with solutions having the concentrations of calcium and orthophosphate found in biological fluids and with pH values ranging from pH 3.0–10.0 indicated that the program was suitable for biological applications. The program was not effective for solutions in which the bromide ion was a principal source of ionic strength probably because of the failure of the extended Debye-Hückel equation under those circumstances. No evidence for the formation of any sodium phosphate complex at normal biological concentrations could be found.
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  • 16
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    Calcified tissue international 10 (1972), S. 171-197 
    ISSN: 1432-0827
    Keywords: Amorphous ; Crystalline ; Calcium phosphate ; Chemistry ; Composition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Des échantillons non lavés de phosphate de calcium amorphe (ACP) contiennent une fraction labile, non remplaçable, riche en phosphate acide avec un rapport Ca/P faible: cette fraction est perdue de façon irréversible au cours du lavage. De l'ACP frais, précipité entre pH 6.6–10.6, varie dans un rapport molaire Ca/P de 1.18 à 1.50 et dans un rapport HPO 4 2− /P total de 33.0% à 10.1%. A pH 7.40, de l'ACP frais a un rapport molaire Ca/P de 1.36±0.02 et contient 22.8 (±2.2)% HPO 4 2− . Les résultats obtenus avec du précipité non lavé ne peuvent s'expliquer par du Ca2+ emprisonné et de l'HPO 4 2− ou du Na+, Cl− et CO 3 2− exogènes. Les phosphates de calcium amorphes constituent une classe de sels ayant des caractères chimiques variables et des propriétés physiques identiques, comparables au verre. Le CaHPO4·xH2O non cristallin peut être un ACP, surtout au cours des phases précoces de formation. A des pH physiologiques, l'ACP se transforme en petits cristaux applatis contenant de fortes quantités de phosphate acide facilement remplaçable. Le fait de laver la couche de surface produit un changement chimique dans les nouveaux cristaux: des cristaux non lavés donnent des diagrammes de diffraction d'apatite peu cristallins, ainsi que des spectres infra-rouges peu nets, intermédiaires entre des apatites et du phosphate octocalcique. Des explications structurales sont proposées et les compositions minérales amorphe/cristalline de l'os et du cartilage sont recalculées.
    Abstract: Zusammenfassung Ungewaschene Proben von amorphem Calciumphosphat (ACP) enthalten eine unersetzliche labile Fraktion, welche reich an saurem Phosphat ist und ein niederes Ca/P-Verhältnis hat und welche während des Waschprozesses unwiderruflich verloren geht. Natives ACP, welches im pH-Bereich 6,6–10,6 ausgefällt wurde, variierte im molaren Ca/P-Verhältnis zwischen 1,18 und 1,50 und in HPO 4 2− /totales P zwischen 33,0 und 10,1%. Bei pH 7,40 hatte natives ACP ein molares Ca/P-Verhältnis von 1,36±0,02 und enthielt 22,8 (±2,2)% HPO 4 2− . Die Werte beim ungewaschenen Niederschlag rühren weder von aus dem Überstand aufgenommenem Ca2+ und HPO2−, noch von außen kommendem Na+, Cl− und CO 3 2− her. Die amorphen Calciumphosphate werden als eine Klasse von Salzen erkannt, welche veränderliche chemische, aber identische glasartige physicochemische Eigenschaften haben. Nicht kristallines CaHPO4·xH2O kann auch ein ACP sein, besonders in den frühen Bildungsstadien. Bei physiologischem pH verwandelt sich ACP in kleine plattenförmige Kristalle, welche große Mengen von leicht ersetzbarem saurem Phosphat enthalten. Das Waschen dieser Oberflächenschicht erzeugte chemische Veränderungen in den resultierenden Kristallen; ungewaschene Kristalle zeigten ein Diffraktionsmuster, das nur schwach demjenigen des kristallinen Aspatites glich, aber ein schlecht aufgelöstes Infrarotspektrum, welches zwischen Apatit und Octocalciumphosphat war. Es werden strukturelle Erklärungen für alle diese Phenomena diskutiert, und revidierte amorph/kristalline Mineralzusammensetzungen von Knochen und Knorpel wurden neu berechnet.
    Notes: Abstract Unwashed samples of amorphous calcium phosphate (ACP) contain an irreplaceable labile fraction, rich in acid phosphate and low in Ca/P ratio, which is irreversibly lost during the washing process. Native ACP precipitated in the pH range 6.6–10.6 varied in Ca/P molar ratio from 1.18 to 1.50 and in HPO 4 2− /total P from 33.0% to 10.1%. At pH 7.40, native ACP had a Ca/P molar ratio of 1.36±0.02 and contained 22.8 (±2.2)% HPO 4 2− . Unwashed precipitate data could not be attributed to either trapped supernatant Ca2+ and HPO 4 2− or extraneous Na+, Cl−, and CO 3 2− . The amorphous calcium phosphates are recognized as a class of salts having variable chemical but identical glass-like, physicochemical properties. Non-crystalline CaHPO4·xH2O may also be an ACP, especially during early formative stages. At physiological pH, ACP transforms to small platy crystals containing large amounts of readily-replaceable acid phosphate. Washing this surface layer produced chemical alterations in the resultant crystals; unwashed crystals had poorly-crystalline apatitic diffraction patterns but exhibited poorly-resolved infrared spectra intermediate between apatite and octacalcium phosphate. Structural explanations for all these phenomena are discussed, and revised bone and cartilage amorphous/crystalline mineral compositions have been re-calculated.
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  • 17
    ISSN: 1432-0827
    Keywords: Boen ; Metabolism ; Rats ; Strontium ; Tooth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé L'on a procédé à une étude approfondie sur l'incorporation et l'enlèvement du strontium des os et des dents de rats dans les cas de régimes alimentaires à forte et faible teneur en strontium. Dans le cas d'un régime par ailleurs en tous points satisfaisant, l'adjonction d'une quantité de strontium de masse égale à celle du calcium provoque un phénomene débilitant très severe chez le jeune rat en pleine croissance, et peut même conduire à la mort du sujet. Les effets pathogéniques du strontium ont été découverts par des méthodes utilisées seulement en recherche dans les tissus durs. L'excédent de cellules osseuses, formées à l'origine du fait de la présence de grandes quantités de strontium dans l'alimentation, se résorbe si l'on passe à un regime à faible teneur en strontium. Il apparait qu'il y a deux types d'élimination dustrontium de l'organisme: a) par excrétion, et b) par assimilation dans les tissus durs. L'on n'a plus à démontrer que le strontium s'intègre par transfert dans les incisives. L'on a également observé, chez les sujets expérimentaux aussi bien que chez ceux du groupe de vérification, que des différences dans le taux de sodium et de potassium apparaissent dans les semi-mandibules.
    Abstract: Zusammenfassung Die Einlagerung sowie die Resorption von Strontium wurde an Rattenknochen und-zähnen mittels Zugabe von niedrigen und hohen Strontiumdosen zu der Diät untersucht. Wird bei einer sonst befriedigenden Diät Calcium durch äquimolare Strontiummengen ersetzt, so entsteht eine Schwächung bei jungen wachsenden Ratten, die bis zum Tode führen kann. Die pathologischen, durch Strontium entstandenen Veränderungen wurden nur mit denjenigen Methoden verfolgt, die zur Untersuchung der harten Gewebe angewendet werden. Das Übermaß an osteoidem Gewebe, welches ursprünglich bei Zugabe großer Strontiummengen zu der Nahrung entsteht, wird in einer darauffolgenden strontiumarmen Diätperiode resorbiert. Die Resorption des Strontiums scheint an zwei physiologische Prozesse gebunden zu sein: a) Ausscheidung aus dem Organismus; b) Eingliederung in die harten Gewebe. Der Strontiumtransport in den Schneidezähnen ist bewiesen worden. Es wurden auch Unterschiede im Natrium- und Kaliumgehalt des halben Unterkiefers bei Experiment- und Kontrollgruppen beobachtet.
    Notes: Abstract The incorporation and removal of strontium from the bones and teeth of rats under conditions of low and high dietary levels of strontium were investigated. In an otherwise satisfactory diet, an amount of strontium equimolar to that of calcium seriously debilitates the young growing rat and may culminate in death. The pathology due to strontium was found by the methods used only in the hard tissues. The excess osteoid formed originally in the presence of large amounts of dietary strontium is removed during a subsequent period of feeding on a low strontium regimen. Strontium removal from participation in physiologic processes appears to be of two types, (a) excretion from the body, and (b) incarceration within the hard tissues. The translocation of strontium to the incisor teeth has been demonstrated. Differences of sodium and potassium contents of the hemi-mandibulae of the experimental and control groups were also observed.
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  • 18
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    Calcified tissue international 31 (1980), S. 45-47 
    ISSN: 1432-0827
    Keywords: Dermestid beetles ; Cleaning bones ; Rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Various parts of the skeleton of normal and osteoporotic rats were compared with respect to their dry weight, ash weight, and calcium content when the bones were cleaned byDermestes maculatus beetles or manually. Both techniques gave similar results. This was also true when whole body calcium measured by neutron activation and total skeletal calcium from bones cleaned by the beetles were compared. Thus dermestid beetles are useful as a technique to clean bones, especially for the parts of the skeleton which are difficult to dissect by hand.
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  • 19
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    Calcified tissue international 32 (1980), S. 77-82 
    ISSN: 1432-0827
    Keywords: Osteoporosis ; Castration ; Density ; Femur ; Rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Forty young (23-day-old) and thirty old (1-year-old) male rats were castrated and sacrificed with controls at intervals up to 18 months of age. No differences were observed between femurs or mandibles of rats castrated at 23 days and those of controls. Year-old castrate rats developed femoral osteoporosis after 2 months, which became more pronounced 4 months after castration. This was characterized by reductions in femoral density, dry weight, dry weight per unit length, and ash weight, and by the appearance of resorption cavities in diaphyseal walls and a sparsity of trabeculae in metaphyses and epiphyses of castrate femurs. These results indicate that the year-old castrate male rat may be a valuable experimental model for studies of the treatment of osteoporosis.
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  • 20
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    Calcified tissue international 34 (1982), S. 510-514 
    ISSN: 1432-0827
    Keywords: Rats ; Osteopenia of oophorectomy ; 1,25-Dihydroxyvitamin D3 ; Parathyroid hormone ; Osteoporosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The effect of ovarian insufficiency on calcium metabolism has been thought to involve an increased bone resorptive effect of parathyroid hormone and possible impaired synthesis of 1,25-dihydroxyvitamin D3. In the present study a rat model allowing for controlled serum levels of parathyroid hormone and 1,25-dihydroxyvitamin D3 was used. Oophorectomy in this species is associated with increased serum levels of 1,25-dihydroxyvitamin D3 and decreased bone mass. Although thyroparathyroidectomy increased bone mass, an increased sensitivity of bone to parathyroid hormone in oophorectomized rats was not observed. Thus the development of the osteopenia did not seem to be related to increased parathyroid hormone sensitivity or to reduced levels of 1,25-dihydroxyvitamin D3. Exogenous 1,25-dihydroxyvitamin D3 increased bone mass in oophorectomized as well as intact rats. Intestinal calcium transport was increased by moderate doses of 1,25-dihydroxyvitamin D3. Intestinal calcium transport was also reduced by thyroparathyroidectomy and increased by the administration of parathyroid extract. A tendency for increased accumulation of 1,25-dihydroxyvitamin D3 in blood in oophorectomized rats has been noted. It is suggested that the tendency to hypercalcemia in ovarian-insufficient females given 1-hydroxylated vitamin D compounds may be related to a diminished metabolism of 1,25-dihydroxyvitamin D3.
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  • 21
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    Calcified tissue international 8 (1971), S. 197-210 
    ISSN: 1432-0827
    Keywords: Fluorescence ; Calcium ; Collagen ; Chemistry ; Bone ; Dentine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Des composants fluorescents de l'os et la dentine sont séparés des hydrolysats alcalins de leur marice sur des colonnes Sephadex C25 CM d'échange cationique. Les concentrations en fluorescence et le spectre d'excitation (λ max 330 nm) et d'émission (λ max 395 nm) sont les mêmes que ceux observés au niveau des matrices intactes et gélatinisées. Les paramètres de fluorescence ne sont pas altérés par hydrolyse. La filtration sur gel à l'aide de colonnes Sephadex G 10 perment de différencier le matériel isolé en deux composants, ayant la même fluorescence et la même absorption UV. La fluorescence est indépendante de pH de 3.5–9.5. Des études de dialyse et de filtration sur gel de matrices gélatinisées indiquent une association étroite du matériel fluorescent avec les chaines polypeptidiques de collagène.
    Abstract: Zusammenfassung Fluorescierende Bestandteile aus Knochen und Dentin wurden in Sephadex C25 CM Kationen-Austauschersäulen von alkalischen Hydrolysaten ihrer Matrices getrennt. Die Fluorescenzintensitäten sowie die Erregungs- (λ max 330 nm) und Emissions- (λ max 395 nm) Spektren waren dieselben wie bei intakten und gelatinisierten Matrices. Die Fluorescenzparameter wurden durch die Hydrolyse nicht verändert. Eine Gelfiltration über Sephadex-G10-Säulen trennte das isolierte Material in 2 Komponenten auf, welche gleiche Fluorescenz- und UV-Absorptionseigenschaften zeigten. Im pH-Bereich zwischen 3,5 und 9,5 war die Fluorescenz unabhängig vom pH. Dialysierversuche sowie Gelfiltrationsexperimente mitden gelatinisierten Matrices zeigten eine starkgefügte Bindung des fluorescierenden Materials mit den Polypeptidketten des Kollagens.
    Notes: Abstract Fluorescent components in bone and dentine were separated from alkaline hydrolysates of their matrices on Sephadex C25 CM cationic exchange columns. The fluorescence levels, and the excitation (λ max 330 nm) and emission (λ max 395 nm) spectra, were the same as those observed in the intact and gelatinised matrices. The fluorescence parameters were unaltered by the hydrolysis procedure. Gel filtration on Sephadex G. 10 columns further resolved the isolated material into two components with the same fluorescence and UV absorption properties. The fluorescence was independent of pH over the range 3.5–9.5. Dialysis and gel filtration studies on the gelatinised matrices indicated a firmly-bonded association of the fluorescent material with the collagen polypeptide chains.
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  • 22
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    Calcified tissue international 33 (1981), S. 129-134 
    ISSN: 1432-0827
    Keywords: Matrix vesicles ; Young/adult ; Rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The occurrence of matrix vesicles in the maxillary bone of normal young and adult rats was demonstrated by both ultrastructural and enzymatic studies. Transmission electron microscopy revealed that the vesicles are invested in trilaminar membranes. Occasionally, crystals were found both within the vesicles and in the surrounding matrix. Separated fractions of vesicles, membranes, and cells were studied biochemically. The amounts of vesicular protein and enzymatic activity per gram bone in the adult rats were significantly lower than in the young. This coincides with the higher number of vesicles observed in the TEM specimens of young rats when compared to that in the old ones. The specific activities of all enzymes examined in the three bone fractions obtained from both young and adult rats were similar. This indicates that no significant difference exists in the enzymatic characteristics of matrix vesicles from the maxillary bone of young and adult rats.
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  • 23
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    Calcified tissue international 12 (1973), S. 125-136 
    ISSN: 1432-0827
    Keywords: Mineralization ; Molt ; Isopod ; Chemistry ; Light microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Au cours de la phase inhabituelle de mue d'un isopode d'eau courante,Lirceuts brachyrus, la moitié postérieure de l'exosquelette est éliminée 24 heures avant la moitié antérieure. A ce stade, une reminéralisation se développe dans la partie postérieure alors que la partie antérieure est dans un stade de pré-mue. Le pourcentage de différence en calcium dans les deux moitiés à mi-mue et mue complète est respectivement de 22% (p〈0.01) et 33% (p〈0.01), indiquant une complexation du calcium pendant la mue. La rapidité de la reminéralisation est illustrée par le fait que le contenu minéral total double dans la partie postérieure entre la mi-mue et la mue totale et dans la partie antérieure entre la fin de la mue et un jour après. Le carbonate de calcium, sous forme de calcite, a pu être identifié par diffraction électronique de coupes fines des téguments.
    Abstract: Zusammenfassung Während der ungewöhnlichen Häutungssequenz des Frischwasser-IsopodenLirceus brachyurus (Harger) wird die hintere Hälfte des äußeren Skeletts 24 Std vor der vorderen Hälfte abgestoßen. In der halbgehäuteten Phase erfolgt Remineralisation im hinteren Teil, während der vordere Teil in einem Vorhäutungszustand ist. Der prozentuale Unterschied des Calciums in den zwei Hälften bei Halb- und Vollhäutungszustand ist 22% (p〈0,01) bzw. 33% (p〈0,01), was andeutet, daß Calcium während der Häutung abgesondert wird. Die Geschwindigkeit der Remineralisation erhellt aus der Tatsache, daß sich der Gesamtmineralgehalt im hinteren Teil zwischen Halt- und Vollhäutung, in der vorderen Hälfte jedoch zwischen Endhäutung und einem Tag nach der Häutung verdoppelt. Calciumcarbonat in kristalliner Calcitform wurde mittels Elektronendiffraktion von dünnen Hautschnitten nachgewiesen.
    Notes: Abstract During the unusual molt sequence of the fresh-water isopod,Lirceus brachyrus (Harger), the posterior half of the exoskeleton is shed 24 hours before the anterior half. At the half-molt stage, occurs in the posterior part while the anterior portion is in a pre-molt condition. The percentage difference in calcium in the two halves at half-molt and full-molt is22 (p〈0.01) and33 (p〈0.01) respectively, an indication that calcium is sequestered during The rapidity of remineralization is illustrated by the fact that the total mineral content doubles in the posterior part between half and full molt and in the anterior half between the end of molt and one day after ecdysis. Calcium carbonate in the calcite cystalline form was demonstrated by electron diffraction of thin sections of the integument.
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  • 24
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    Calcified tissue international 2 (1968), S. 60-66 
    ISSN: 1432-0827
    Keywords: Fluorides ; Topical/Pharmacodynamics ; Penicillin/Pharmacodynamics ; Calcification ; Physiologic/Drug Effects ; Rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé L'objet de ce travail était de comparer le phénomène de la maturation postéruptive dans les molaires des rats ordinaires et sans germes à qui on a donné à manger un régime «non-cariogène». On a étudié les effets de l'application topique du fluorure et de la nourriture de la penicilline sur la maturation. Les molaires des rats ordinaires (nourris d'un régime «chow» — aliment mixte pour les animaux préparé d'habitude sous la forme d'une farine ou en boulettes) traités topiquement avec une solution à 1% de NaF et les molaires des rats ordinaires nourris d'un régime «chow» complété avec la penicilline à 1% ont montré un degré de maturation significativement plus grand que les molaires des rats de la même portée nourris de «chow» et traités avec de l'eau. De l'autre côté, les molaires des rats sans germes traités topiquement avec une solution à 1% de NaF n'ont montré aucune différence significative dans le degré de maturation des molaires de rats de contrôle semblables traités topiqument avec l'eau. Ces résultats sont en accord avec l'hypothèse que dans un milieu normal le procédé de minéralisation (maturation) est opposé par un procédé de déminéralisation. Le procédé de déminéralisation est un résultat de la production d'acide par des bactéries qui métabolisent les aliments encastrés dans les «sulci» des molaires. On propose que dans les animaux ordinaires le fluorure et la penicilline peuvent influencer la maturation en empêchant le procédé de déminéralisation. Dans les animaux sans germes le procédé de déminéralisation est absent parce que la microflore orale est absente.
    Abstract: Zusammenfassung Der Zweck dieser Arbeit war ein Vergleich des nach dem Durchbruch auftretenden Reifungsphänomens der Backenzähne von gewöhnlich und von keimfrei gehaltenen Ratten, die mit einer nicht-cariogenen Diät ernährt wurden. Es wurden die Auswirkungen von topisch angewendetem Fluorid, verbunden mit Penicillin-Fütterung auf die Reifung untersucht. Die Backenzähne der gewöhnlich gehaltenen Ratten (mit “Chow”-Diät ernährt), die mit einer 1%igen Na-Fluoridlösung topisch behandelt wurden, und solchen deren “Chow”-Diät zu 1% mit Penicillin versetzt wurde, zeigten einen erheblich größeren Reifungsgrad als die Backenzähne von Tieren des gleichen Wurfes, die nur mit der “Chow”-Diät und Wasser ernährt wurden. Diese Resultate stimmen mit der Hypothese überein, daß in einer normalen Umgebung dem Mineralisationsprozeß (Reifung) ein Demineralisationsprozeß entgegenwirkt. Der Demineralisationsprozeß ist durch eine Säureproduktion von Bakterien bedingt, welche die in die Zahnfurchen eingepreßten Nahrungsbestandteile metabolisieren. Es wird die Annahme vorgeschlagen, daß Fluoride und Penicillin bei den gewöhnlich gehaltenen Tieren die Reifung durch eine Inhibition des Demineralisationsprozesses beeinflussen. Bei keimfrei gehaltenen Tieren findet dagegen kein Demineralisationsprozeß statt, da die orale Mikroflora fehlt.
    Notes: Abstract The purpose of this work was to compare the phenomenon of post-eruptive maturation in molars of conventional and germfree rats fed non-cariogenic diets. The effects of topical application of fluoride and feeding penicillin on maturation were studied. The molars of conventional rats (fed a chow diet) treated topically with a 1% NaF solution and the molars of conventional rats fed a chow diet supplemented with 1% penicillin showed a significantly greater degree of maturation than did the molars of littermate rats fed chow and treated with water. On the other hand, the molars of germfree rats treated topically with a 1% NaF solution showed no significant difference in degree of maturation from the molars of similar control rats topically treated with water. These data are consistent with an hypothesis that in a normal environment the mineralization (maturation) process is opposed by a demineralization process. The demineralization process is a result of production of acid by bacteria metabolizing the diet impacted in the sulci of molars. It is proposed that in conventional animals fluoride and penicillin may influence maturation by inhibiting the demineralization process. In the germfree animals the demineralization process is absent because the oral microflora is absent.
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    Calcified tissue international 13 (1973), S. 259-270 
    ISSN: 1432-0827
    Keywords: Fluorapatite ; Exchange ; Chemistry ; Crystallography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Un échantillon minéral provenant de Burgess, Canada s'est révélé être un speciment exceptionnellement pur de fluoroapatite après analyse chimique et cristallographique. La composition globale de cet échantillon est la suivante: $$(Ca^2 )9.98(Sr^{2 + } ,Na^ + ,K^ + ,Mg^{2 + } )0.02(PO_4^{3 - } )5.98(HCO_3^ - ,CO_3^{2 - } )0.02(F^ - )2$$ . L'axe cristallographique C est de 6.865 A et l'axe a de 9.374 A. Des expériences d'échanges réalisés à l'aide de45Ca,32P et18F indiquent la présence de gros cristallites de surface spécifique de l'ordre de 1 m2/g. Il apparait que l'interprétation physique des processus d'échange ne nécessite pas l'existence de compartiments séparés, avec chacun son propre facteur cinétique, les échanges semblent être simplement liés à un changement exponentiel dans l'énergie libre de la réaction. Pour la réaction suivante: $$(Ca)_5 (PO_4 )_3 OH solide + (F^ - ) \rightleftarrows (Ca)_5 (PO_4 )_3 F solide + (OH^ - )$$ , la constante thermodynamique de 101.26 a été calculée, suggérant que le fluorapatite se forme toujours aux dépens de l'hydroxyapatite dans des conditions physiologiques. Cette transformation se continue en abaissant le pH.
    Abstract: Zusammenfassung Eine Mineralprobe aus Burgess, Kanada, erwies sich nach chemischer und kristallographischer Analyse als außergewöhnlich reines Fluorapatit. Die Gesamtzusammensetzung entspricht: $$(Ca^{2 + } )_{9,98} (Sr^{2 + } ,Na^ + ,K^ + ,Mg^{2 + } )_{0,02} (PO_4^{3 - } )_{5,98} (HCO_3^ - ,CO_3^{2 - } )_{0,02} (F^ - )_2 $$ . Die kristallographische c-Achse wurde bestimmt und ergab 6,865 Å, und die a-Achse ergab 9,374 Å. Austauschwerte, welche durch Anwendung von45Ca,32P und18F erhalten wurden, deuteten auf große Kristalliten mit einer spezifischen Oberfläche von ca. 1 m2/g. Die Befunde deuten darauf hin, daß für die physikalische Erklärung des Austauschvorganges keine separaten Kompartimente mit eigenen kinetischen Faktoren nötig sind, sondern daß der Austausch mit dem exponentiellen Wechsel in der freien Energie der Reaktion in einfacher Beziehung steht. Für die Reaktion $$(Ca)_5 (PO_4 )_3 OH_{in fester Form} + (F^ - ) \rightleftarrows (Ca)_5 (PO_4 )_3 F_{in fester Form} + (OH^ - )$$ wurde als thermodynamische Konstante 101,26 errechnet, was darauf deutet, daß unter physiologischen Bedingungen immer Fluorapatit auf Kosten von Hydroxyapatit entsteht. Diese Umwandlung wird erhöht, wenn das pH erniedrigt wird.
    Notes: Abstract A mineral specimen from Burgess, Canada, proved upon chemical and crystallographic analyses to be an exceptionally pure sample of fluorapatite. The over-all composition corresponds to $$(Ca^{2 + } )_{9.98} (Sr^{2 + } ,Na^ + ,K^ + ,Mg^{2 + } )_{0.02} (PO_4^{3 - } )_{5.98} (HCO_3^ - ,CO_3^{2 - } )_{0.02} (F^ - )_2 $$ . The crystallographic c-axis was determined to be 6.865 Å, and the a-axis 9.374 A. Exchange data obtained by employing45Ca,32P, and18F indicate the presence of large crystallites with a specific surface of the order of 1 m2/g. It is indicated that the physical interpretation of the exchange process does not require the existence of separate departments, each with its own kinetic factor, but that the exchange may be simply related to the exponential change in the free energy of the reaction. For the reaction $$(Ca)_5 (PO_4 )_3 OH_{solid} + (F^ - ) \rightleftarrows (Ca)_5 (PO_4 )_3 F_{solid} + (OH^ - )$$ the thermodynamic constant has been calculated to be 101.26, implying that fluorapatite always will form at the expense of hydroxyapatite under physiologic conditions. This transformation will be furthered by lowering the pH.
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  • 26
    ISSN: 1432-0827
    Keywords: Bacterial amphophile ; Purification ; Chemistry ; Resorption ; Ca influx ; Cyclic AMP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The bone resorptive factor and amphipathic antigen (AcA) previously identified by us in preparations fromActinomyces viscosus have been partially purified, characterized chemically, and compared. They elute at the same location on chromatography with Ac 22. The fatty acid composition of AcA and the bone resorptive factor is the same. Some differences in carbohydrate composition are observed. TheActinomyces factor does not affect calcium influx or cyclic AMP in isolated bone cells. Therefore it is concluded that AcA stimulates resorption either by gaining entrance into bone cells or by way of a yet undetermined second messenger.
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    Cell & tissue research 135 (1972), S. 211-228 
    ISSN: 1432-0878
    Keywords: Osteoclasts ; Rats ; Bone resorption ; Lysosomes ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Osteoclasts in metaphyses from young rats were systematically sectioned at different levels. Two types of osteoclasts were recognized. One type had no ruffled border while the other, and predominant type contained a ruffled border in a part of its length; some of the latter contained two ruffled borders. The closest contact between osteoclast and bone occurred at the level of the ruffled border and this bone under the border showed characteristic changes indicative of resorption. In some osteoclasts the ruffled border consisted of numerous slender cytoplasmic projections separated by very narrow spaces or channels while in other osteoclasts it was more open. The ruffled border was commonly surrounded by a transitional zone containing numerous thin filaments. The osteoclast usually had its greatest dimension at the level of the ruffled border and the cytoplasm here contained many bodies and vacuoles but a sparse endoplasmic reticulum. Away from the level of the ruffled border the cytoplasmic vacuoles and bodies were fewer while the endoplasmic reticulum was often more pronounced. Parts of the osteoclasts were usually situated close to a vessel. It is suggested that there is a correlation between the development of the ruffled border and the degree of bone resorption and that osteoclasts without a ruffled border are, at least temporarily, inactive with respect to bone resorption. The numerous cytoplasmic bodies, interpreted as lysosomes, are presumed to be important in the resorption process. The closely adjacent positioning of osteoclasts and vessels may facilitate the transport of resorption products to the blood.
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    Cell & tissue research 125 (1972), S. 306-331 
    ISSN: 1432-0878
    Keywords: Parenchyma of organs ; Rats ; Regeneration ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die sowohl nach singulärer 3H-Thymidin-Injektion als auch nach kontinuierlicher 3H-Thymidin-Dauerinfusion an Ratten erhobenen autoradiographischen Befunde lassen folgende Schlüsse ziehen: 1. Die während des Wachstums im Vergleich zum Ende der Foetalperiode ganz auffällige, unmittelbar postpartal nachweisbare Depression des 3H-Thymidin-Markierungs-Index im Parenchym von Leber, Niere und Pankreas wird auf eine funktionelle Umstellung und zumindest in der Leber auch auf eine strukturelle Umgestaltung bezogen. Schon am 30. Tag ergeben sich Anhaltspunkte für eine Umschaltung auf einen langsamen Proliferationsmodus, die bei 60 und 120 Tagen mit Halbierung der DNS-Syntheserate vollends abgeschlossen ist. 2. In der kompensatorisch regenerierenden Leber nach 2/3-Teilhepatektomie wird der Anteil nicht proliferierender Zellen — d.h. die non growth fraction — von juvenilen über eben ausgewachsene bis zu senilen Tieren kontinuierlich größer. 3. Bei der reparativen Regeneration in der unterbundenen Niere nach temporärer 1stündiger Ischämie ist der Proliferationsumfang in den am stärksten geschädigten Nephronabschnitten auch am größten. Es führt das Stratum subcorticale, dann folgt die Zona intermedia, das Stratum labyrinthicum und die Zona basalis. 4. Demgegenüber weist die Topik proliferierender Zellen bei kompensatorischer Nierenregeneration nach kontralateraler Ischämie bzw. Nephrektomie wohl quantitative aber keine qualitativen Unterschiede zu der beim physiologischen Zellersatz von Kontrollen auf. Das Stratum labyrinthicum zeigt die höchsten Werte und dann stellt sich eine stufenweise erfolgende Abnahme der prozentualen Markierung über das Stratum subcorticale zur Zona intermedia und Zona basalis ein. 5. Anhand der autoradiographischen Daten wird ein Modell für die Proliferation von Leberepithelien juveniler und ausgewachsener Ratten entworfen. Weiter befaßt sich dieses Modell mit der Zellneubildung nach Teilhepatektomie im Verlauf und nach Abschluß der Regeneration. Nach den entwickelten Vorstellungen wirkt eine partielle Hepatektomie an ausgewachsenen und senilen Tieren durch Verkleinerung der non growth fraction und Vergrößerung des proliferating pools im Sinne einer Verjüngerung der proliferatorischen Potenz des Leberepithels.
    Notes: Summary The autoradiographic results reported, are obtained on rats after single injections of 3H-thymidine as well as continuous 3H-thymidine infusions. They lead to the following conclusions: 1. Compared to the end of embryonic development the 3H-labelling index in parenchyma of liver (epithelium), kidney (tubule), and exocrine pancreas (acinus) is depressed during the first day of postnatal growth. From 1–4 days postpartal fluctuations occur, afterwards the labelling index increases between 7 and 12 days and from there on a decrease is observed up to 120 days. This depression and fluctuation of the labelling index is probably connected with a functional transposition and, especially in the liver, with a structural transformation. The reduction of the mean grain density of labelled nuclei by about a factor of 2, begins already at day 30 and is completed on day 60 and 120. It depends on a reduction of the rate of DNA synthesis. This might be explained as a consequence of a commutation from the rapid to the slow mode of cellular proliferation. 2. In the compensatory regenerating liver after 2/3 partial hepatectomy the portion of non labelled nuclei—i.e. the non growth fraction—increases continuously from juvenile to young adult and especially up to senile animals after a postoperative continuous 3H-thymidine infusion. 3. During reparative regeneration in the ligatured kidney following temporal (1 h) ischaemia the extent of proliferation after postoperative continuous 3H-thymidine infusion is hightest in those regions of the nephron with the largest postischaemic damage. The percentage of labelled nuclei decreases from the stratum subcorticale to the zona intermedia, stratum labyrinthicum, and zona basalis. 4. On the other hand only quantitative but not qualitative differences exist in the topic of proliferating cells between compensatory regeneration in the unligaturated kidney after contralateral temporal ischaemia or nephrectomy and the physiological cell renewal of controls. After continuous 3H-thymidine infusions the highest percentage of labelled cells is observed within the stratum labyrinthicum and then a gradual decrease occurs from there to the stratum subcorticale, zona intermedia and basalis. Thus, cellular proliferation in compensatory regeneration of the kidney is only an enhanced form of those proliferative processes occuring during physiological cell renewal. 5. With the autoradiographic data a model concerning proliferation of liver epithelia in juvenile and adult rats has been constructed. Furthermore this model deals with cell renewal during and after regeneration following partial hepatectomy. The conclusion is, that partial hepatectomy diminishes the non growth fraction and enlarges the proliferating pool. Thus this operation acts as a rejuvenating process in the proliferating potency of liver epithelia.
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    Cell & tissue research 234 (1983), S. 679-689 
    ISSN: 1432-0878
    Keywords: Odontogenesis ; Rats ; Cyclophosphamide ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cyclophosphamide-induced changes in rodent odontogenesis were investigated by light and electron microscopy in four-day-old Sprague Dawley rats given one injection of 40 mg/kg of body weight of cyclophosphamide and killed at intervals of one hour, one day, one week and two weeks. Incisor and molar teeth were dissected from the animals, fixed in 2.0% glutaraldehyde in 0.1 M sodium cacodylate with 3.4% sucrose, and subsequently some were incubated for alkaline phosphatase reaction, and embedded in Spurr's medium for sectioning at light- and electron-microscopic levels. From three days a cell-sparse zone was created in the pulp in the growing end of the tooth and progressive cellular changes were observed which became more severe in the one-week and two-week specimens. Subodontoblast and adjacent pulpal cells were the most affected showing nuclear changes, damage to, or loss of, organelles, and inclusion bodies. Odontogenic epithelium was less affected and odontoblasts appeared to be unaffected by the drug. A new irregular matrix was laid down in the defect area and seemed to be the product of depolarized odontoblasts. This new matrix showed alkaline phosphatase activity, as did the cells embedded in it, and later it became mineralized. It is speculated that the polarity of odontoblasts might be maintained by an intact subodontoblastic layer; when this is lost the odontoblasts become depolarized and capable of secreting matrix from both ends.
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  • 30
    ISSN: 1432-0878
    Keywords: Rats ; Radioautography ; Cholesterol-3H ; Steroids (biosynthesis) ; Adrenal glands
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the zona reticularis of the rat adrenal cortex three types of cells are to be observed: light, dark, and very dark cells. A time study of the incorporation of cholesterol-3H into these elements has been made. The data obtained from autoradiographic study are discussed in relation to the hypothesis that the light cells are elements in active steroido-synthesis, the dark cells are resting elements, and the very dark cells are elements in degeneration.
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    Cell & tissue research 217 (1981), S. 11-21 
    ISSN: 1432-0878
    Keywords: Intestinal mucosa ; Small intestinal epithelium ; Ultrastructure ; Duodenum ; Jejunum ; Stereology ; Rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Quantitative macroscopic, light-microscopic and electron-microscopic studies were performed on the small intestine of fasted and non-fasted adult, male Sprague-Dawley rats. In non-fasted rats the small intestine was longer than in fasted rats. Due to the presence of villi the surface area in the duodenum and the jejunum was enlarged about six times. The microvilli on the villous crests caused a surface enlargement by 13 times in the duodenum (value corrected for overestimation due to section thickness), and 19 times in the jejunum of the fasted rats. At the base of the villi these values were about 50% lower. It was calculated that, in the fasted rats, the total enlargement of the luminal surface area — due to villi and microvilli — was 63 times in the duodenum and 81 times in the jejunum (corrected for section thickness). Differences between the villous crest epithelium and the villous base epithelium were also found with regard to the mean cell height, and the volume densities of the absorptive cell nuclei, the mitochondria, and the paracellular channels.
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    Plant systematics and evolution 171 (1990), S. 1-14 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Compositae ; Chemistry ; systematics ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The broad knowledge of the chemistry of theCompositae allows the discussion of its relevance for the systematics and evolution within the family. Furthermore a separation into subfamilies can be supported by the observed differences in the distribution of the main constituents in the tribes.
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    ISSN: 1741-0444
    Keywords: Drugs ; Psychology ; Rats ; Rotameter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
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    Biotechnology and Bioengineering 7 (1965), S. 6-8 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
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    Biotechnology and Bioengineering 7 (1965), S. 10-13 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
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    Biotechnology and Bioengineering 7 (1965), S. 435-443 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Many antimicrobial agents are available for commercial use, but only a few are truly sporicidal and can be used as chemosterilizers. The action of ethylene oxide, propylene oxide, and β-propiolactone is well documented. Strong acids, e.g., hydrochloric acid, or alkalis may be used as chemosterilizers but their use is extremely limited. The synthetic phenolics accompanied by boiling were recommended, but heat cannot always be employed. Chlorine and iodine have been used in higher concentrations. The use of 8% formaldehyde or 20% formalin was suggested by Spaulding.17 Other aldehydes possess antimicrobial potency. According to work performed in our laboratories, the sporicidal activity of certain alcoholic, saturated dialdehyde solutions equalled or surpassed that of formaldehyde. These included glyoxal, succinaldehyde, and glutaraldehyde. Aqueous alkaline glutaraldehyde solutions killed the most resistant bacterial spores, e.g., B. subtilis and Cl. tetani, within a few hours (Borick1,2). Glutaraldehyde, a 5-carbon dialdehyde, was shown to be a chemosterilizer when tested by various methods, destroying bacteria, including M. tuberculosis, fungi, and viruses. Acid glutaraldehyde solutions stored at room temperature are highly stable, whereas alkaline solutions show a significant change in pH and a diminution of glutaraldehyde concentration on alkalinization. For this reason, fresh (not over 2 weeks old) alkaline glutaraldehyde solutions can be used as chemosterilizers.
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    Biotechnology and Bioengineering 7 (1965), S. 3-6 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
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    Biotechnology and Bioengineering 7 (1965), S. 54-58 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
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    Biotechnology and Bioengineering 8 (1966), S. 371-378 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Previous studies indicated that when cells grown in a NaCl-free glucose medium were subjected to a high salt concentration, cellular constituents were released which were metabolized by the cells in preference to glucose. In the present study, cells grown on glucose in high salt medium were subjected to a shock loading of salt-free medium. In this case, the resulting lysate was not used in preference to glucose; the lysate was metabolized only after an acclimation period following glucose utilization. It was shown by injecting chloramphenicol into the reaction liquor during glucose metabolism that new protein synthesis was required in order to metabolize the lysate. This response represents an additional way in which a rapid change in salt concentration can adversely affect biological treatment of waste waters, and a new type of situation in which sequential removal of substrates occurs.
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    Biotechnology and Bioengineering 7 (1965), S. 245-268 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In order to find effective methods to isolate microorganisms that excrete large amounts of amino acids, a number of mutants of Escherichia coli ATCC 4157 were prepared and characterized. The majority were isolated for resistance to amino acid analogs. The penicillin method was also employed to select potential producer strains devoid of a biosynthetic enzyme in one case and a catabolic enzyme (tryptophanase) in another. Both of these enzymes were suspected of reducing the yield of an excerted amino acid. The identification of amino acid excreting colonies was aided by the use of pigmented auxotrophic test bacteria.Amino acid analog resistance was frequently found to increase amino acid production. In particular, excretion of valine and glutamic acid could be achieved with comparative ease. Conditions of culture were of extreme importance for the amount and kind of amino acid produced. Under certain conditions a norvaline-resistant strain and even better a leucine-requiring derivative of it excreted more than 2 mg./ml. of valine into the culture medium. The acetolactate-forming enzyme of this strain was not repressible by leucine in contrast to the same enzyme in the wild type. Reversal of the growth inhibitory effects of amino acid analogs by amino acids was studied on agar plates. This method gave too complex results to be a simple guide in the selection of analogs suitable for the isolation of a particular type of production mutant.
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    Biotechnology and Bioengineering 7 (1965), S. 129-132 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A procedure for sterilization of microbiological media with β-propiolactone has been developed. Special attention was paid to the maintenance of mild conditions to enable the treatment of media sensitive to high temperature or low pH. The maximum temperature allowed was 40°C. and automatic neutralization of acid produced during hydrolysis was effected by the use of titration unit. The apparatus could be used for several successive sterilization cycles without disconnection.
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    Biotechnology and Bioengineering 7 (1965) 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
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    Biotechnology and Bioengineering 7 (1965), S. 8-10 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
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    Biotechnology and Bioengineering 7 (1965), S. 13-16 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
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  • 45
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    Biotechnology and Bioengineering 7 (1965), S. 21-29 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
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  • 46
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    Biotechnology and Bioengineering 9 (1967), S. 329-342 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Notes: A process for manufacturing disodium 5′-guanylate was devised. 5′-Amino 4-imidazole carboxamide riboside (AICA-R) was accumulated with an amount over 100 times those reported in the literature by fermentation of D-glucose with a non-exacting purineless mutant derived from Bacillus megaterium JAM 1245) by x-ray irradiation. The influence of RNA, amino acids, and salts on AICA-R accumulation was clarified. Appropriate aeration and agitation was found necessary. The (60-hr, cultivation of the medium containing 8% of D-glucose gave AICA-R in the concentration above, 11 g/l. AICA-R thus accumulated was separated from the fermentation broth by ion-exchange technique and subjected to synthetic processes to yield disodium 5′-guanylatc with the yield over 40%, based on AICA-R.
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  • 47
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    Biotechnology and Bioengineering 8 (1966), S. 337-352 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Oxygen uptake of Penicillium chrysogenum hyphae growing in automatically aerated deep cultures was the subject of local and periodical change. The change depended on the concentration of carbon dioxide which accumulated in the gas phase of system during the evolution of foam bubbles, and which was suddenly liberated when the foam was destroyed. The actual concentration of sunflower oil added as an antifoaming agent also influenced the oxygen uptake of culture.
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  • 48
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    Biotechnology and Bioengineering 8 (1966), S. 405-431 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
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  • 49
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    Biotechnology and Bioengineering 8 (1966), S. 456-460 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
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  • 50
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    Biotechnology and Bioengineering 8 (1966), S. 465-471 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The addition of as little as 2 ppb of manganese to ferrocyanide-treated beet molasses during citric acid fermentation by Aspergillus niger NRC A-1-233 caused a 10% reduction in acid yield and undesirable change in the morphology of the organism from the normal pelletlike form to the filamentous from. Still smaller additions (0.4-2ppb) caused undesirable pellet clumping, while greater additions (2-100 ppb) gave further decreases in yield. The yield obtained at 100 ppb was less than 25% of that obtained at 1 ppb or less. None of the other metals tested (Al3+, Ca2+, Co2+, Cu2+, Fe2+, Mg2+, Ni2+, Zn2+) visibly changed pellet morphology, and only Al3+, Fe2+, and Zn2+ at relatively higher concentrations (5-25ppm) reduced acid yield. The adverse effect of manganese on growth and acid production was not affected by addition of the other metals.
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  • 51
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    Notes: Oxygen Utilization as a scale-up parameter is evaluated in two antibiotic-producing fermentations. This method of scale-up was used in tank-to-tank and in flash-to-flash scale-up studies. Antibiotic yields and cell weight trends were generally duplicated in the replicate runs, with some discrepancy noted in chlortetracycline yields at high aeration levels. The apparatus for measuring oxygen consumption rates and for automatically controlling oxygen utilization, according to a predetermined pattern, is described.
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  • 52
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    Biotechnology and Bioengineering 8 (1966), S. 581-593 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Biological systems can be used in three types of fuel cell: depolarization (or concentration) cell, product cell, and redox cell. The possibilities and theoretical limitations of each type of cell have been considered in terms of the metabolic activities of microorganisms and the coupling of these to electrochemical systems. The use of cell extracts and enzymes, particularly in an insoluble form, has been discussed.
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  • 53
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    Biotechnology and Bioengineering 8 (1966), S. 195-215 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In three series of experiments, 3-l., 20-l., and 150-l. bacterial cultures were grown in stirred, deep culture vessels to average bacterial cell densities of 71 × 108, 63 × 108, and 43 × 108 viable organisms per milliliter, respectively, and then infected with phage. The average yield of progeny phage in each case was ca. 3000 mpfu (minimum plaque-forming units) per cell. Thus, the average mass of phage obtained in the 3-l. experiments was not less than 124 mg./l., calculated from the plaque counts, assuming a particle size of 3.6 × 106 Daltons for the μ2 phage. This is about twentyfold higher than is obtainable by conventional methods in aerated, shaken culture flasks. The actual phage yields are probably much higher than the minimum values calculated from plaque counts. For example, in the case of one of our culture lysates which was purified at King's College, the efficiency of plating was shown to be only 19%. The carbon dioxide evolution rate of cultures was measured and used as a guide to the time at which phage should be added. In this way, greater control of cultural conditions was obtained than is possible in shaken flasks. For the best yield of phage per milliliter of culture, the optimum time for phage infection was such that bacterial lysis just prevented the carbon dioxide evolution rate from reaching its potential maximum. The major factor influencing the phage yield per milliliter of culture was the aeration capacity of the culture vessel used. All had maximum aeration capacities much higher than those obtainable in shaken culture flasks. Cultures grown and infected in 3-l. Vessel operated under conditions of low aeration gave poor yields of phage. The reason for this are discussed.
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  • 54
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    Biotechnology and Bioengineering 10 (1968), S. 205-232 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A generalized logistic equation is proposed for the mathematical representation of batch culture kinetic data. Properties of the equation are discussed. A computer program is used to fit the generalized equation to both artificial and actual batch culture data. The equation is shown to be capable of fitting data exhibiting lag, exponential, deceleration, stationary, and death phases, as well as diauxic growth. The fitted equation is useful for differentiation, interpolation, and other manipulations of the data, and it is a convenient means of data storage.
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    Biotechnology and Bioengineering 10 (1968), S. 252-254 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
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  • 56
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    Biotechnology and Bioengineering 10 (1968), S. 277-289 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Notes: Micrococcus sodonensis KY 3765 and Arthrobacter citreus KY 3155 were found capable of accumulating IMP in media supplemented with hypoxanthine as a precursor. High concentrations of phosphate and magnesium salts were required for high yields of IMP. Manganese deficiency in the media was also essential. Excessive Mn2+ effects were also seen in the IMP fermentation carried out with an adenineless mutant, of Cornynebacterium glutamicum. In M. sodonensis, R5P-like substances, 5-phosphoribose pyrophosphokinase and IMP pyrophosphorylase, were leaked out, of the cells grown in suboptimal Mn2+ levels. This excretion was inhibited by high levels of Mn2+. Such a phenomenon was not noted in A. citreus. An adenineless mutant (KY 7208) of Brevibacterium ammoniagenes was found to accumulate an appreciable amount of IMP. The chemical changes in this fermentation showed that, hypoxanthine was first produced de novo, excreted, and then reconverted into IMP by a salvage pathway. When hypoxanthine was added to 7208 culture, IMP yield was increased appreciably. In fact exogenous 14C-hypoxanthine was incorporated into 14C-IMP. Subsequent experiments showed that indeed Br. ammoniagenes ATCC 6872, a parent culture of KY 7208, was able to produce IMP, GMP, and AMP, in good yield from hypoxanthine, guanine, and adenine, respectively.
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    Biotechnology and Bioengineering 10 (1968), S. 331-358 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Notes: The mechanism of oxygen transfer through a pure culture floc of Zoogloea ramigera I-16M has been described quantitatively. Oxygen uptake rates for both blended and nonblended floc particles indicated that, at a certain dissolved oxygen concentration, diffusion of oxygen through the floc matrix was the mechanism controlling the rate of oxygen utilization by the floc. This mechanism was quantitatively described by determining the oxygen diffusivity values for the floc. The diffusional distances of the floc particles along with the oxygen utilization rates of the floc were measured on floc grown under various conditions. Anoxic core equations were then used to calculate the oxygen diffusivity values for each experiment. These diffusivity values were then used to estimate the oxygen concentrations necessary in activated sludge plants.
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    Biotechnology and Bioengineering 10 (1968) 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
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    Biotechnology and Bioengineering 10 (1968), S. 445-455 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Notes: Many hyphomyceteous fungi have been found to produce closely related toxic metabolites which form the class of compounds called scirpenes. The structures of those compounds are reviewed and current studies on their biological activity and possible implication in moldy corn poisoning are discussed.
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    Biotechnology and Bioengineering 9 (1967), S. 357-364 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Notes: The design and operational characteristics of a sell-priming aerator are described. The aerator works without a compressor. H sucks the desired air quantity into the tank and distributes it, uniformly and in very fine bubbles over a certain cross-section. The design and operational characteristics of a mechanical defoamer are described. The defoamer is mounted to the top of the fermentation tank and separates foam by centrifugal force into air and liquid. It is capable of handling foams of different composition and quality without, the addition of anti foam agents. Using submerged vinegar fermentation, production of baker's yeast., and industrial waste, water treatment as examples, the performance of aerators and defoamers of different, sizes is discussed.
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    Biotechnology and Bioengineering 9 (1967), S. 413-427 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Notes: The alcoholic fermentation of grape juice by a wine yeast was studied batchwise at pH 3.6 and 4.05 to develop kinetic equations relating cell concentration, N, to product concentration, P. In the exponential growth phase \documentclass{article}\pagestyle{empty}\begin{document}$$ dP/dt + BP = A{\rm ln}N/\mu - C $$\end{document} where A, B, and C are constants, and μ is the specific growth rate. In the stationary phase, where the cell population is constant, \documentclass{article}\pagestyle{empty}\begin{document}$$ dP/dt = B(P_m - P) $$\end{document} was found to apply. This equation, which incorporates a stoichiometric constant, Pm, predicted correctly the operation of a continuous fermentor at pH 3.6 and at 4.05. To study more fully the effect of alcohol concentration on yeast growth, a continuous fermentor was used in which the grape juice feed was supplemented with pure alcohol. At pH 3.6 the specific growth rate varied as, \documentclass{article}\pagestyle{empty}\begin{document}$$ ({\rm 1}/N)(dN/dt) = \mu _{{\rm max}} [{\rm 1} - 0.235(P - 2.6)] $$\end{document} There was no growth inhibition below an alcohol concentration of 2.6 g./100 cc., but inhibition was complete above 6.85 g./100 cc. This is a modified form of the relation suggested by Hinshelwood.1 The data suggest that growth in batch culture was limited not only by alcohol but also by some other factor, probably a nutritional deficiency.
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    Biotechnology and Bioengineering 9 (1967), S. 443-447 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Notes: A description is given of a large glass vessel suitable for growing algae and other microorganisms in shaken culture. The main feature of the flask is the coneshaped base around which water circultes when the flask is shaken on a reciprocal mechanism.
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    Biotechnology and Bioengineering 9 (1967), S. 471-485 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Notes: In bacterial extraction of copper from low-grade copper sulfide ores, at least three contributions are made by Thiobacillus ferrooxidans. They are: (1) enzymatic oxidation and consequent solubilization of insoluble sulfides; (2) regeneration of ferric lixiviant for chemical oxidation and solubilization of insoluble sulfides; and (3) partial fixation of externally introduced iron in the ore. Although it is not possible at the present time to measure each of these contributions separately, it is possible to measure the combined contributions. Such measurements reveal a strong dependence of extraction efficiency on various physical, chemical, and biological factors. The following physical factors may affect the rate of bacterial copper extraction: particle-size of ore, oxygen and carbondioxide supply, oxidation-reduction potential, pH, temperature, adsorption and ion exchange capacity of ore, and surface tension effects. The following chemical factors may influence the rate of copper extraction: the mineralogy of the ore, the nature of the gangue, the distribution of the sulfide minerals in the host rock, the external supply of ferrous or ferric iron, and the availability of inorganic and organic nutrients. Finally, the following biological agents in addition to T. ferrooxidans may influence the rate of copper extraction: fungi, protozoa, Thiobacillus thiooxidans, and heterotrophic bacteria. Proper control of these various factors is essential for efficient bacterial extraction of copper from low-grade ore. It is recognized that the foregoing environmental factors also influence chemical copper extraction.
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    Biotechnology and Bioengineering 9 (1967), S. 545-558 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Interfacial phenomena are directly involved in the adhesion of a strain of Chlorella, a unicellular alga, to glass surfaces in simple ionic solutions. The principal mechanisms governing the adhesion appear to be electrostatic interaction between electrical double layers and various specific surface interactions resulting from surface heterogeneity and ion adsorption. Under most conditions the algal cells and glass surfaces have negative zeta potentials, and adhesion to glass will not occur; but if, for example, FeCl3 is added to an algal-glass system immersed in 0.05M NaCl, the algal and glass surfaces will possess very different zeta potentials, and adhesion will be strongest under those conditions which produce the greatest, difference in zeta poentials. Prior pretreatment and usage of glass apparatus greatly affect the glass zeta potentials and the adhesion of algal cells to glass. An apparatus for measuring a relative set of numbers representing the force of adhesion of algal cells is described.
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    Biotechnology and Bioengineering 9 (1967), S. 623-625 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
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    Biotechnology and Bioengineering 10 (1968) 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
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    Biotechnology and Bioengineering 10 (1968), S. 787-800 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Notes: Growth of Saccharomyces cerevisiae LBG H 1022 on ethanol under transient-state conditions was studied. As a cultivation device, an aerated Chemap fermentor combined with continuously working gas analyzers for oxygen and carbon dioxide was used. Yeast cell dry matter, substrate concentration, specific oxygen uptake, specific carbon dioxide release, and respiration quotient were measured during the different transient states. Depending on which range of the dilution rate the initial steady state was found, we obtain different responses to the shift experiment. For the lower range, up to D = 0.07, we deal with damped oscillations ranging above and below the steady-state values. For the higher specific growth rates, the rate of damping is strongly enhanced and the shape of the curves becomes an asymptotic approach to the final steady states.
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    Biotechnology and Bioengineering 10 (1968), S. 891-894 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
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    Notes: For centuries, diverse plant and animal materials have been fermented by various bacteria, yeasts, and fungi to make excellent foods. The kinds of micro organisms used in traditional fermentation are restricted to a relatively few genera, including Aspergillus, Rhizopus, Mucor, Actinomucor, Monascus, Saccharomyces, Neurospora, Acetobacler, Bacillus, and Lactobacillus. The two principal advantages of food fermentations over other processes are to add flavor and to prevent spoilage. Fermented fish is a common food in the Orient and may have been the first product made by fermentation. Flavor is especially important in vegetable diets based on bland foods such as rice. Shoyu is the best, known oriental food fermentation, and it is very widely used as a flavoring agent. Be sides this fermentation, there are a large number of additional ones not so well known outside the Orient, whose products serve as seasoning or flavoring agents. Miso and natto are prepared from soybeans in Japan. Sufu is a cheese like product made from soybean milk in China. Tempeh and ontjom are Indonesian foods prepared from soybeans and peanuts, respectively. These food fermentations are discussed with emphasis on how they are produced and the flavor formed.
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    Biotechnology and Bioengineering 9 (1967), S. 305-319 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Various biochemical transformations involved in vinous fermentations are reviewed from the point of view of their formal ion of volatile aroma or flavor compounds in fermented beverages. In addition to the recently elucidated processes for the formation of aliphatic primary alcohols of molecular weight greater than that of ethanol, Nordström's mechanism for the formation of esters during fermentation is discussed. Experimental evidence supporting this mechanism in vinous fermentation is presented; the White Riesling grape is found to contain insignificant, quantities of esters while the wine prepared from these grapes, analyzed immediately after fermentation, shows relatively large amounts of several volatile esters. In addition, in an investigation of an older California sherry, ethyl acid malate is found to be nearly all the single isomer with the hydroxyl group on the carbon adjacent, to the free carboxyl group. This finding suggests an enzymatic (presumably vinous fermentative) production rather than simple chemical esterification in the wine after fermentation. An extension of Nordström's mechanism for ester production is proposed to explain the formation of certain secondary amides found in wines.
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    Biotechnology and Bioengineering 9 (1967), S. 365-374 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Notes: Mannitol has long been known as a product of glucose metabolism by some strains of Aspergillus. Apparently no concerted effort, has been made to develop a practical fermentation process to make mannitol. Work at the Northern Laboratory has shown that nearly all strains of white Aspergillus produce significant amounts of mannitol; many strains of black Aspergillus also have this characteristic. Aspergillus candidus NRRL 305 is an exceptionally good mannitol producer. Studies on a fermentation process were conducted in 20-1, stainless steel fermentors, without baffles. Czapek-Dox medium, modified by addition of corn meal, yeast extract, and enzymatically hydrolyzed casein was the most satisfactory medium tested. Suitable increments of glucose were fed daily to the fermentors. The duration of the fermentation was from 10 to 16 days. The effects of agitation, aeration, temperature, and pH of the medium were studied. Under optimal conditions yields of mannitol approached 50% of the glucose consumed.
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    Biotechnology and Bioengineering 9 (1967), S. 439-442 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
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    Biotechnology and Bioengineering 9 (1967), S. 457-470 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Eutrophication, or fertilization, has become a major water pollution problem associated with the discharge of mineral-rich sewage eflluent. A metabolic process to remove dissolved phosphate from sewage through the action of sewage microorganisms is under development. The process, unlike other proposed solutions to the problem, would not require tertiary treatment of the sewage. Laboratory studies have produced promising data. Early reports from municipal sewage treatment plants confirm the expectation that the process may be feasible for widespread use.
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    Biotechnology and Bioengineering 9 (1967), S. 515-531 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Notes: A method for the control of dissolved oxygen tension in growing microbial cultures is described. The apparatus consists of a motor-driven air sparge pipe which may be lowered or raised to give a variable point of entry of the air stream into the culture liquid and hence a variable gas dispersion and gas-liquid contact time. Control of the sparge pipe position is by means of a feedback control loop consisting of a dissolved oxygen probe, an on/off controller, and a reversing electric motor which drives the sparge pipe. The difficulty presented by the relatively slow response of the oxygen probe has been overcome by incorporating an adjustable rate of control action.
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    Biotechnology and Bioengineering 10 (1968), S. 83-88 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A mathematical model based on the Einstein law of photochemical equivalence is proposed to describe the batch growth of unicellular algae. The model was applied in an integrated form to cell concentration versus growth time data taken over an extended range of cell concentrations which include both the regions of “exponential” and “linear” growth. It is shown that a certain function of cell concentration contained in the integrated form of the model is linearly dependent on the growth time over both the “exponential” and “linear” growth regions.
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    Biotechnology and Bioengineering 10 (1968) 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 77
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    Biotechnology and Bioengineering 10 (1968), S. 159-176 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Growth of Saccharomyces cerevisiae LBG H 1022 on ethanol under steady-state conditions was studied. As a cultivation device, an aerated Chemap fermentor combined with continuously working gas analyzers for oxygen and carbon dioxide was used. Dry matter, substrate concentration, yield, specific oxygen uptake, specific carbon dioxide release, and respiration quotient, as well as nitrogen, carbon, phosphorus, hydrogen, and protein content of the cells were measured in dependence on the dilution rate. Cell size distribution, as a function of the specific growth rate, was determined with the aid of a Celloscope 202. A fair agreement with the theory of continuous culture for all metabolic curves could be established. An increased turnover rate resulted from the addition of glutamic acid to the synthetic growth medium. The primary effect of this supplement could be a rise in the flow rate of the tricarboxylic acid cycle.
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  • 78
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    Biotechnology and Bioengineering 10 (1968), S. 238-242 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: We have recently constructed a 10-mm, light path quartz cuvet which will accept a Clark oxygen electrode; it is temperature controlled and is suitable for use in a Unicam (Cambridge, England) SP 800 recording spectrophotometer. Several enquiries have prompted this publication, although such an apparatus was mentioned much earlier by Chance and Williams,1 and has been used extensively.Figure 1a, b, c, and d and their legends provide sufficient detail for the construction of the cuvet and provision of the commercially available electrode, quartz faces, stirring motor and disk magnet. Circuit diagrams for temperature control (range 22-38°C., ± 0.2°C.) and stirrer speed control are shown in Figure 2a and b. The cuvet is shown situated in the spectrophotometer cell housing in Figure 3, and the cuvet with its associated equipment is shown in Figure 4.
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  • 79
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    Biotechnology and Bioengineering 10 (1968), S. 815-828 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The intracellular levels of seven enzymes in mouse LS cells growing in suspension culture at controlled dissolved oxygen partial pressures (pO2) have been measured. During the growth of each culture large fluctuations were observed in the levels of some enzymes, particularly aldolase and cytochrome oxidase. Mean values for the concentration of each enzyme during the growth phase have been calculated. These results are discussed in relation to previous observations made on the growth of mouse LS cells.
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  • 80
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    Biotechnology and Bioengineering 10 (1968), S. 865-875 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Continuous cultivation of the yeast Candida lipolytica on gas oil was studied from the viewpoint of biomass production and oil deparaffination. Optimum conditions wore found at the dilution rate D = 0.16-0.19 when biomass productivity 1.7 g/l/hr and yield coefficient. y = 0.92 were achieved. At deparaffination to the same freezing point, more than double the production of biomass and deparaffined oil during a given time unit was achieved in a continuous process than in batch cultivation. Consumption of substrate was followed in both cultivation processes and it was confirmed that individual n-alkanes of gas oil were degraded at various rates and yields. Results proved optimum cultivation conditions to depend on concentration and composition of the paraffinic fraction of gas oil used. To achieve these conditions the continuous process may be controlled by choice; of suitable dilution rate and concentration of gas oil.
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  • 81
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    Biotechnology and Bioengineering 11 (1969), S. 19-36 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Kinetic, studies were made on continuous cultivation applying the theory of microbial cell growth that was derived previously by the authors introducing the concepts of critical concentration and coefficient of consumption activity. General equations for microbial cell concentration for continuous cultivation in continuous-stirred tank and tubular type reactors were derived theoretically. Productivity of cell mass in continuous cultivation was analyzed kinetically and the behavior of mutant populations in continuous cultivation is briefly discussed.
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  • 82
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    Biotechnology and Bioengineering 12 (1970) 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 83
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    Biotechnology and Bioengineering 12 (1970), S. 51-61 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A model of oxygen absorption in microbiological systems of zero order reaction rate is proposed. The partial differential equation was solved to predict the profile of the oxygen concentration boundary layer next to a gas-liquid interface. Generally speaking, the presence of microbial cells always helps to increase the oxygen absorption rate over that of physical absorption. Only when the microbiological reaction is slow as judged by the fact that the reaction time, tr, is much larger than the diffusion time, tD, can one rightfully approximate the oxygen absorption in microbiological suspensions by physical absorption.
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  • 84
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    Biotechnology and Bioengineering 12 (1970), S. 85-92 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Glucoamylase bound to DEAE-cellulose in 0.05 M sodium acetate, pH 4.0, is active in the conversion of starch to glucose. The activity of the DEAE-cellulose-bound enzyme ranges from 16 to 55% of the activity of the free enzyme. Binding of the enzyme narrows the pH optimum to approximately 4.0 and lowers the temperature optimum to 40-50°C as compared to a 60°C temperature optimum for the free enzyme. Concentrations of acetate buffer above 0.1 M disrupt the DEAE-cellulose-enzyme complex. Columns were used with some success for the continuous conversion of starch. Pretreatment of the starch with α-amylase and clarification were necessary to prevent blocking of the column. Columns maintained activity for more than 3 weeks of continuous operation.
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  • 85
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    Biotechnology and Bioengineering 11 (1969), S. 605-622 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The oxygen transfer coefficient has been investigated in S. noursci and S. lavendulae fermentation broths obtained from fermentors of different operating volumes (61., 30001., 20,0001.). Fermentors had KLas values ranging from 1.0 to 17.0 min-1, calculated from sulphite oxidation rates. The dynamic measurement of the volumetric oxygen transfer coefficient. (KLa) has been performed in the different fermenting systems. As the fermentation progressed, especially in the first stages, KLa values have decreased in both fermentations and in each system of fermentors. In order to characterise the whole fermenting system an average KLas was calculated from the obtained KLa values. The average KLa grew with increasing KLas values and ranged from 0.03 to 3.72 min-l. Some factors possibly having an influence on the, change of KLa have been studied.The oxygen transfer coefficients of the broths have been measured in falling films and ranged from 0.05 to 0.4 cm min-1. The flow conditions have been characterized by Reynolds numbers of broths varying between 1.0 and 60.0. The average thickness of the falling films have been measured and plotted against Reynolds number. The Re+ which is the breaking-point of the plot increased as the fermentation proceeded. In the region of Re+ the values of the oxygen transfer coefficient increased rapidly. An approximate correlation could be established between the Re+ and the physical properties of fermentation broth.
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  • 86
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    Biotechnology and Bioengineering 11 (1969), S. 647-681 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The presence of microorganisms have been shown to increase by over 40% the mass transfer rates from small oxygen bubbles at low Reynolds number flow. This increase was found to be due only to the microbe cells as inert particles disrupting the quasi-static liquid surface film surrounding the gas bubble and thus decreasing the gas-liquid interfacial resistance. The observed increase in oxygen mass transfer rates was not dependent on cell viability, no effect was noted due to cell-liquid interfacial resistance, nor was the phenomenon due to altering the physical properties of the liquid during cell propagation. These results were obtained in a unique plexiglass apparatus designed for observing under a microscope a small (0.4 mm dia.) stationary oxygen bubble collapsing into a flowing fluid. The oxygen bubble was injected by a small hypodermic needle and the fluid was suspensions of the yeast Candida intermedia, the bacterium Pseudomonas ovalis, 0.3μ alumina, as well as base points of cell free broth and pure water. Several well-known chemical inhibitors of oxidative phosphorylation were used to limit cell oxygen uptake. Calculations of oxygen mass transfer rates were compared with the semi-empirical model of Frössling, the circulating sphere model of Levich, and the rigid sphere concentration boundary layer model of Fried-lander, the latter two showing strong Reynolds number dependence that may be due to radial fluid motion.
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  • 87
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    Biotechnology and Bioengineering 12 (1970), S. 541-560 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A continuous symbiotic algal-bacterial system was developed consisting essentially of a mixed Chlorella-activated sludge culture which would efficiently remove nutrients from wastewater under aerobic conditions without supplementary aeration. Oxygen decline data were fitted to a mathematical model used to predict respiratory rates, photosynthetic oxygenation, and steady-state oxygen concentrations. Stable relative biological populations and a dissolved oxygen concentration of about 2 mg/1 were maintained during steady-state operation with daily harvesting of excess biomass. Respiratory and physiological relationships indicated that the carbon dioxide-oxygen balance is a primary control that governs the steady-state operation of a symbiotic algal-bacterial culture. The close association of the algae and bacteria resulted in an algal-bacterial floc with settled rapidly yielding a clear supernatant.
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    Keywords: Chemistry ; Biochemistry and Biotechnology
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    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Dialysis was attempted as a means to alleviate the product-activated controls presumed to limit the formation of threonine by an auxotrophic mutant of Escherichia coli strain W. The occurrence of inhibition rather than enhancement of yields by dialysis was traced to the fact that threonine actually was not inhibiting its own synthesis. Instead, α,ε-diaminopimelic acid became depleted, but the imbalance could not be corrected by exogenous replacement.
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    Biotechnology and Bioengineering 12 (1970), S. 641-644 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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    Biotechnology and Bioengineering 12 (1970), S. 771-801 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Biotechnology and Bioengineering 12 (1970) 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
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    Biotechnology and Bioengineering 12 (1970), S. 873-887 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The removal of cellular material from fermentation broths is of importance in many fermentation processes. The present work compares the performance of recently developed polyelectrolyte flocculating additives with traditionally available additives. Objectives are to establish criteria for the choice of a flocculating additive and establish optimum conditions for the formation of stable, fast settling floe, and for quantitative separation of cellular material from the medium. Fermentation broths of actively growing Candida intermedia were used to evaluate the effectiveness of fifty commercial flocculating additives at different dosages and pH values. Certain strong anionic and strong cationic polyelectrolytes and mineral hydrocolloids were found to be most effective in their enhancement of settling rates. Some differences in behavior exist between glucose grown cells, hydrocarbon grown cells, and washed cells in buffer suspension. Flocculation of cells from fermentation broths is concluded to be highly dependent upon adsorbed material. A high charge density to interact or compete with adsorbed material and a solubility in the adsorbed material are important factors in choosing an additive for a given application. The fluid mechanics of a flocculating suspension is an important variable since low shear does not provide adequate contacting between cells for floe formation and high shear leads to floe breakup. An apparatus was constructed to grow floe under constant fluid mechanical conditions both in laminar and turbulent flow regimes. Turbulent shear was found to be very important in forming large, compact floe in cases where irreversible ionic bridging is the mechanism as for the strong anionic polyelectrolyte, polystyrene sulfonate. Adequate mixing is required to disperse the flocculating additive, but the level of turbulence is relatively unimportant in cases where reversible colloidal bridging is the mechanism as for the mineral hydrocolloid, bentonite.
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    Biotechnology and Bioengineering 12 (1970), S. 947-959 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In order to isolate proteins from microalgae, yeasts and bacteria, cell disintegration in a special ball-mill was performed. The degree of disintegration of the different microorganisms was compared. The dependence of disintegration on bead size and on the ratio between the volume of suspension and the volume of glass beads was also investigated. Nondisintegrated and disintegrated cells were extracted with sodium hydroxide and the amount of extractable nitrogen and the amount of nitrogen precipitable at pH 4.0 were determined. The dependence of yield on the sodium hydroxide concentration, extraction time, and temperature was studied. When extracting undisintegrated cells, very low yields were obtained and the nitrogen extracted was mostly nonproteinous. For disintegrated cells high yields were obtained. An optimum was found after extraction with 0.3-0.5% sodium hydroxide; at pH 11.0-11.5. The precipitate obtained represented 60-70% of the cell nitrogen. The nitrogen content of the precipitate was 12-14% of the dry weight.
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    Biotechnology and Bioengineering 12 (1970), S. 1081-1098 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Optimization methods based on the continuous maximum principle and the calculus of variations were used to calculate optimum temperature profiles for batch penicillin fermentations. These methods were first applied to several general models to develop effective techniques for the numerical solution of the equations. Subsequently, these methods were applied to two particular models, derived from experimental data, and the optimum temperature profiles were determined. The results indicated that an improvement, in penicillin yield of about 15% was possible if the optimum temperature profiles were followed.
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    Biotechnology and Bioengineering 12 (1970), S. 1-17 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The precipitation of proteins with heteropolyacids has been studied for the purpose of large scale primary purification. A precipitate will form if the pH of the reaction between purified ovalbumin, hemoglobin, trypsin, pepsin, bovine serum albumin, ovomucoid, gelatin or ribonuclease and tungstrophosphoric, tungstosilicic or molybdosilicic acid is close to the isoelectric point of the protein and does not cause the dissociation of the heteropolyacid. Below the isoelctric point, the percent precipitation depends on the conformational changes of the protein. The precipitation of ovalbumin with tungstophosphoric decreases as the ionic strength of the buffer increases and is independent, of the protein concentration. Mixtures of ovalbumin and bovine serum albumin, though having close isoelectric points, can be separated by varying the concentration of the precipitant. The electropositive groups which combine with the tungstophosphoric acid are guanidino, ε-amino and imidazole. No precipitation is given by the α-amino groups. Filtrates of microbial fermentations containing lactase, glucose aerode-hydrogenase, alkaline protease, amyloglucosidase, and transglucosylase have been purified by precipitation with heteropolyacids.
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    Biotechnology and Bioengineering 12 (1970), S. 63-74 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A pilot-plant process has been developed for the continuous extraction and partial purification of prolyl-tRNA synthetase from mung bean. The bean slurry was wet ground in a hammer mill, clarified by two-stage centrifugation, and the protein in the effluent fractionated by precipitation at pH values of 5.2 and 4.2. The throughput was 13 kg dry bean/hr. The improved extraction process and reduced processing time resulted in an enzyme product with a specific activity 16 × that previously obtained in the batch process. The yield was also 50-60 times higher.
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  • 97
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    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The processing of fermentor-grown, edible yeast involves the removal of water. This can be accomplished through concentration followed by drum or spray drying. This study presents the essential physical properties of yeast solutions necessary for calculation of production economics. In addition, our initial studies of vacuum concentration show that some of the cell leakage necessary for good drying characteristics occurs. The residence time during concentration is also sufficient, to yield 1-2 log cycles of kill which are mandatory since the final product, should contain no viable cells.
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    Biotechnology and Bioengineering 12 (1970) 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Biotechnology and Bioengineering 12 (1970), S. 273-290 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The concept of a “critical oxygen concentration” is conventionally considered to hold for the submerged aerobic fermentation of glucose to gluconic acid. Above the critical level the fermentation rate is supposedly independent of oxygen concentration. In this work it is shown that, at a given agitation rate, the fermentation is independent of dissolved oxygen when above the critical. However, an increase in the agitation rate results in an increase in the fermentation rate. This increase was shown to be accompanied by an increase in the gluconolactone concentration in the broth. Gluconolactone, an intermediate in the reaction pathway, is hydrolyzed nonenzymatically to gluconic acid. Evidence is presented to suggest that the increased gas-liquid interfacial area brought about by increased agitation causes an increased net rate of lactone formation. This in turn results in an increased rate of hydrolysis of the lactone to gluconic acid. A model is presented hypothesizing that negatively charged cells adsorb at the gas-liquid interface. These cells attract hydrogen ions, causing a lowering of the pH in the film around the bubbles. It is this lowered pH which is considered to bring about increased fermentation rates when the interfacial area is increased. Supporting evidence is presented.
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    Biotechnology and Bioengineering 12 (1970) 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
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    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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