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  • 1970-1974  (657)
  • 1965-1969  (384)
  • 1890-1899
  • Biochemistry and Biotechnology  (853)
  • Electron Microscopy
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Erscheinungszeitraum
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  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 364 (1974), S. 111-127 
    ISSN: 1432-2307
    Schlagwort(e): Electron Microscopy ; Coronary Arteries ; Atherosclerosis ; Aging ; Smooth Muscle
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The coronary arteries were studied by electron microscopy in normal rats weighing 65 to 535 gm; fixation was accomplished by perfusion for 20 min at 110–130 mm Hg. In rats of all ages (but especially in the oldest) the arterial wall contained deposits of abnormal intercellular material, consisting of granules, vesicles, myelin figures and other debris. These deposits were present in the intima and media, but rare in the adventitia; there was suggestive evidence that medial cells phagocytized some of the material. The adventitia was characterized by 1–4 layers of cells with extremely thin protoplasmic expansions wrapped around the vessel (“veil cells”) and containing lysosome-like bodies as well as phagosomes. These findings, taken as a whole, suggest the following sequence of events. During normal life, the media produces cellular debris, by cell death as well as by fragmentation of cellular processes; part of these debris are phagocytized by smooth muscle cells, part diffuse outward to the adventitia where they are taken up by specialized cells (the “veil cells”). However, due to relative inadequacy of phagocytosis in the media, the debris continue to accumulate and form intercellular deposits that increase with age. It is possible that this natural phenomenon may by itself set a maximal limit to the life-span of the arterial wall.
    Materialart: Digitale Medien
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 363 (1974), S. 249-258 
    ISSN: 1432-2307
    Schlagwort(e): Hypertensin (Angiotensin) ; Catecholamins ; So-Called Epinephrine Myocarditis ; Rat Heart ; Optical Microscopy ; Electron Microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Pathomorpliological comparative studies on structural damage to rat cardiac muscle following administration of hypertensin and arterenol, with and without pretreatment with reserpine to empty the catecholamine reserves were performed. The question is whether and to what degree angiotensin induced cardiac damage, which is viewed microscopically as the so-called epinephrine myocarditis, can be regarded as an indirect catecholamine effect. The following could be deduced: 1. Hypertensin causes a damage pattern similar to that of arterenol as seen under the light microscope and corresponds to the so-called epinephrine myocarditis. 2. The electron microscope demonstrates definite differences in the pattern of damage to the myocardium: hypertensin affects primarily the mitochondria, while arterenol affects the myofibrils. 3. Hypertensin and arterenol damage mainly the subendocardial tissue of the left heart: hypertensin affects more the region of the base of the left ventricle, arterenol more the region of the left ventricle apex. 4. Pretreatment with reserpine blocks the damaging effects of hypertensin in the rat heart for 12 hours. After 24 hours the full picture of the damage pattern has reappeared. Arterenol is lethal to animals pretreated with reserpine. 5. The pathogenesis of the damaging effects of hypertensin on rat cardiac muscle is discussed.
    Materialart: Digitale Medien
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Lung 150 (1974), S. 185-189 
    ISSN: 1432-1750
    Schlagwort(e): Paraquat Poisoning ; Morphology ; Electron Microscopy ; Light Microscopy ; Letal Course ; Human Lung ; Lung Fibrosis ; Proliferative Alterations ; Degenerative Alterations ; Pathogenesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Morphological alterations in the lungs of 3 cases of paraquat intoxication with prolonged lethal course (10, 11, and 25 days) are reported. Combined light-and electronmicroscopic studies reveal that 10 and 11 days after the ingestion of paraquat the endothelium of the occassionally congested capillaries is intact. The basal membranes have only scarce alterations. They are sometimes naked because of shadding of both types of pneumocytes with severe alterations, e.g. lipid accumulation in the cytoplasm. In the vast alveolar edema, red blood cells, some round cells, strands of fibrin, and lamellar cell debris are seen. There are also varying amounts of polymorphnuclear leucocytes and alveolar macrophages with many phagolysosomes and cytosegresomes. Fibroblasts with lipid droplets between the extensive RER form varying amounts of collagen fibrils in the alveolar and sometimes in the very edematous interstitial space. Sometimes surrounded by collagenous material, they thus devoured by macrophages. 25 days after paraquat intoxication a severe alveolar fibrosis, focal interstitial fibrosis, and areas with atelectasis are found. Due to artificial respiration and changed ventilation mechanics, there were large areas with hemorrhage and a honeycomb-like structure of the remaining lung parenchyma. The pathogenesis of the degenerative and proliferative lung alterations is briefly discussed.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 16 (1974), S. 109-127 
    ISSN: 1432-0827
    Schlagwort(e): Dentinogenesis ; Diphosphonates ; Calcification ; Collagen ; Electron Microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Abstract The effects of high doses of ethylene-1-hydroxy-1,1-diphosphonate (EHDP) were investigated at the light microscopic and subcellular level. The administration of EHDP at a concentration of 7.5–10 mg P/kg body weight/day over a short period of time resulted in complete inhibition of crystal formation in predentin and pre-enamel. An increased predentin width was observed and within newly-formed predentin areas the formation ofcollagen fibrils was grossly disturbed. In addition, fine precipitates appeared in the ground substance. The presence of unusual thread-like elements within specific bodies in the cytoplasm of the odontoblastic processes may be indicative of an interference by EHDP in e.g. the synthesis of precollagen. The possibility of an inhibition by EHDP of the extracellular aggregation of collagen molecules is also discussed. EHDP further inhibited crystal formation within dentinal globules. Functioning ameloblasts were grossly affected in EHDP-treated rats, and it is suggested that this is related to an inhibition of crystal formation in pre-enamel.
    Materialart: Digitale Medien
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Archives of microbiology 98 (1974), S. 271-274 
    ISSN: 1432-072X
    Schlagwort(e): Proteus vulgaris ; Bacteriocin ; Electron Microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The intracellular development of a bacteriocin in a strain of Proteus vulgaris was investigated. Particles which resemble the bacteriocin make their appearance in the cell after 60 min induction with mitomycin C. At this stage they appear as broad bands of tightly-packed phage tail-like structures. With longer periods of induction the bands are disrupted to liberate individual phage tail-like particles.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 30 (1974), S. 33-41 
    ISSN: 1432-0533
    Schlagwort(e): Organic Mercury Compound ; Late Pathological Changes in Peripheral Nerves ; Electron Microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Wistar strain of male rats of 100–110 g were used, 5 for an experimental and 5 for control group. 1 mg of organic mercury (methyl methylmercuric sulfide: CH3HgSCH3) was given by mouth each day for 10 days (total dose 9–10 mg) to the experimental group. 600 days afterwards the experimental and control rats were killed. Only the peripheral nerves showed changes, small myelinated nerve fibres with thick myelin sheaths in groups. Around these fibres occurred extremely small myelinated nerve fibres and isolated large unmyelinated fibres, and appeared to be regenerated fibres. Destruction of myelin sheaths and cavity formation in the axons were observed in these fibres. The changes in the axons were remarkable at the nodes of Ranvier.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 30 (1974), S. 11-24 
    ISSN: 1432-0533
    Schlagwort(e): Ataxia ; Rabbit ; Degeneration ; Cochlear Nuclei ; Electron Microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary This hereditary animal ataxia is selective in its sites of involvement within the nervous system, which include principally the central cerebellar, vestibular and cochlear nuclei. Ultrastructural detail has been described for central cerebellar and vestibular nuclei. Herein the cochlear complex of 18 rabbits with this ataxic condition (ax/ax from the strain AX of the Jackson Laboratory) have been examined. The gene is a lethal one, but the animals were used before they became moribund and between 7 and 57 days after the onset of symptoms. By light microscopy nine cell types (Osen, 1969a, b; 1970) have been identified in the cochlear nuclei of the cat. That distribution can also be identified in electron micrographs of rabbit cochlear nuclei, providing there is a singular opportunity to compare cellular vulnerabilities within the ataxic condition, and establish the principal features of associated neuropil alterations. The cochlear nuclei, cerebellar cortex and central nuclei, and the vestibular nuclei, arise from the ependyma of the rhombic lip of the fourth ventricle, making them close allies in their genetic origins. Pathological alterations were evident in scattered neurons from all nuclear sources by 7–15 days following symptom onset. At 15 days the number of altered neurons evident in electronmicrographs had increased markedly, cells becoming involved at a more rapid pace than those already affected could be removed. Much glycogen is evident from 7 days onwards in both neuropil and neurons. It occurs in considerable amounts in astrocytic processes and less abundantly in endbulbs and somata. By 20 to 25 days spongioform changes in neuropil are prominent, and thereafter the extracellular spaces coalesce to produce a lacunar appearance showing little glycogen. It would appear, therefore, that all neuron types, the endbulbs, and the astrocytic processes are markedly involved simultaneously in the spongioform transformation which features this type of ataxia. Involvement of cochlear nuclei only differs in pathological detail from that found at the other involved sites, and the differences seen relate principally to the architectonics of the nuclei, including size and density of the packing of contained elements.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 30 (1974), S. 73-84 
    ISSN: 1432-0533
    Schlagwort(e): GM1 Gangliosidosis ; Friesian Calves ; Inborn Metabolic Error ; Histochemistry ; Electron Microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Histoenzymic and ultrastructural alterations in the brains of seven calves with GM1 gangliosidosis are described. A decreased oxidative enzyme activity in neurons was accompanied by an increase in acid phosphatase activity. Membranous cytoplasmic bodies were present in neurons and glia. The periodicity of the membranes was about 5.5 to 6.0 nm. Electron-dense, membrane-bound inclusions were present in perithelial cells. The lesions were compared with those of gangliosidoses in other species.
    Materialart: Digitale Medien
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  • 9
    ISSN: 1432-0533
    Schlagwort(e): Progressive Multifocal Leukoencephalopathy ; Hirano Bodies ; Papova Virus ; Paramyxovirus-like ; Nuclear Bodies ; Electron Microscopy ; Neurofibrillary Tangles
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We have identified three structures that have not previously been reported in electron microscopic examinations of brain from patients with PML: 1. coiled nuclear bodies that may possibly represent tubular paramyxovirus nucleocapsids, 2. Hirano bodies and 3. Neurofibrillary tangles. The paramyxovirus-like material is interesting in view of reports of a transition between nuclear bodies and tubular paramyxovirus nucleocapsids and because of a possible interaction between syncytiogenic paramyxoviruses and Papova viruses in the pathogenesis of SSPE and PML. A study of the Hirano bodies in this case, taken in conjunction with the findings of others leads us to believe that these structures are formed from an overgrowth of neurofilaments. The presence of tangled masses of neurofilaments in the processes of neurons also seen in the present case is consistent with this hypothesis.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 27 (1974), S. 201-213 
    ISSN: 1432-0533
    Schlagwort(e): Infantile Neuroaxonal Dystrophy ; Spheroids ; Perikaryon ; Electron Microscopy ; Membranous Profiles ; Dense Bodies ; Protein Syntheses
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Electron microscopic findings of a cortical biopsy from a four-year-old child suffering from muscular weakness and psychomotor retardation are presented. Morphological evidence obtained in this study suggests a unique pathogenetic mechanism underlying INAD. The spheroids appear to be caused by an accumulation of a macromolecular substance synthesized in the neuron and transported to the nerve endings. The abnormal substance initially takes the form of an amorphous material, it eventually aggregates into highly characteristic angulated membranous profiles. The selective involvement of the nerve endings, synapses and motor end plates in this disease suggests a derangement of the metabolic pathway in the synthesis or packaging of the neurotransmitters or their receptors.
    Materialart: Digitale Medien
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  • 11
    Digitale Medien
    Digitale Medien
    Springer
    Archives of microbiology 97 (1974), S. 27-38 
    ISSN: 1432-072X
    Schlagwort(e): Mass Mating ; Electron Microscopy ; Cell Fusion ; Membrane Structure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The process of mating reaction of Saccharomyces cerevisiae was studied by electron microscopy. Prior to the dissolution of the part of the cell walls separating the conjugating pair of cells, the thinning of the electron transparent layer of the cell wall occurs at the part toward which the nuclei are migrating. After the dissolution of the cell walls of the conjugating cells, the cell membranes become associated with each other, then to be broken and rejoined. The first diploid bud emerges from about the middle of the zygote. The morphological changes during the mating reaction are discussed in relation to the biochemical changes so far known.
    Materialart: Digitale Medien
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  • 12
    Digitale Medien
    Digitale Medien
    Springer
    Archives of microbiology 98 (1974), S. 311-329 
    ISSN: 1432-072X
    Schlagwort(e): Dictyostelium discoideum ; Inorganic Polyphosphate ; Electron Microscopy ; Enzymes ; Polyphosphate Metabolism ; Cellular Slime Mold ; Polyphosphatase ; Polyphosphate-ADP-Phosphotransferase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The concentration of inorganic polyphosphates in Dictyostelium discoideum was low in the amoebae. A ca 5-fold increase took place during the early stages of multicellular development and was followed by a decrease during the intermediate stages. Electron micrographs showed the presence of electron dense material in all parts of the differentiating cells. The substance was most frequently observed in various types of vacuoles. Two enzymes of polyphosphate metabolism were identified and studied in cell-free extracts: a polyphosphatase and a polyphosphate-ADP-phosphotransferase. No polyphosphate-glucose-phosphotransferase or polyphosphate-AMP-phosphotransferase activities were observed in the extracts. The specific activity of the polyphosphatase, pH optimum 7.6, was ca 30 nmol Pi·min-1·mg protein-1 at all stages of development. The enzyme activity was not inhibited by 0.01 M orthophosphate. The polyphosphate-ADP-phosphotransferase, pH optimum ca 7.7, was studied in the direction of ATP. The enzyme specific activities were very low, about 0.2 nmol P·min-1·mg protein-1, and rather constant during differentiation. The enzyme activity was inhibited by orthophosphate and by excess ADP. It was concluded that the polyphosphate-ADP-phosphotransferase did not contribute significantly to the formation of ATP during multicellular development, and that polyphosphate did not act as a phosphagen in the differentiating cellular slime mold. It was suggested that polyphosphate served as a phosphate store and as a means of regulating the intracellular orthophosphate concentration during development.
    Materialart: Digitale Medien
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  • 13
    Digitale Medien
    Digitale Medien
    Springer
    Archives of microbiology 99 (1974), S. 281-294 
    ISSN: 1432-072X
    Schlagwort(e): Spirochete ; Artemia ; Brine Shrimp ; Electron Microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract 1. A spirochete which occurs in tissues of the brine shrimp,Artemia salina, was studied by light microscopy and transmission electron microscopy. A total of seven infected shrimps were encountered. 2. Under darkfield illumination, most spirochete cells inArtemia blood were 6–13 μ long and 0.3–0.4 μ wide. Coiling was variable and often irregular. 3. When tissues of the maxillary gland (kidney) and nearby organs were examined by electron microscopy, spirochete cells were found in both extracellular and intracellular locations. These microbes possessed the ultrastructural features typical of members of the Order Spirochaetales: a) a slender protoplasmic cylinder (0.18 μ average diameter), b) axial fibrils (150 A average diameter), and c) an outer envelope or sheath (approximately 75 A thick). 4. Counts made of the number of axial fibrils evident in transverse sections of spirochete cells were consistent with the hypothesis that this spirochete has a 1-2-1 arrangement of axial fibrils. 5. Non-spiral forms were observed in the haemocoel and in the lumen of the maxillary gland.
    Materialart: Digitale Medien
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  • 14
    Digitale Medien
    Digitale Medien
    Springer
    Archives of microbiology 100 (1974), S. 145-162 
    ISSN: 1432-072X
    Schlagwort(e): Complex Flagella ; Fine Structure ; Electron Microscopy ; Optical Diffraction ; Flagellin ; Flagellar Motion
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Zellen von Rhizobium lupini H 13-3 besitzen 5–10 peritrich inserierte komplexe Geißeln, deren Feinstruktur durch Hochauflösungs-Elektronenmikroskopie und lichtoptische Diffraktion analysiert wurde. Das Geißelfilament hat einen Durchmesser von 160 Å und besteht aus einem zylindrischen Kern (Durchmesser ca. 110 Å), der fest von drei Bändern einer helikalen Scheide umgeben ist. Die Scheidenbänder sind 49 Å breit, durch 49 Å-Intervalle voneinander getrennt und haben eine Steigung von 31°. Die komplexen Geißelfilamente bestehen aus einem 43 000-Dalton-Protein, das den Kern und die helikale Scheide aufbaut. Beide gehen übergangslos aus dem proximalen Geißelhaken hervor, der einen Durchmesser von 150 Å und eine Länge von 600 bis 800 Å hat. Die Diffraktionsanalyse des Geißelhakens zeigte eine helikale Grundanordnung von globulären Untereinheiten, die ein Oberflächengitter von 5 parallelen Schrauben (Steigung 29° bzw. 33°) bilden, von denen jede fast 11 Untereinheiten pro Helixungang trägt. Die komplexen Geißeln von R. lupini H 13-3 und Pseudomonas rhodos [Schmitt et al.: J. Bact. 117, 844–857 (1974)] sind ein neuer Typ von Bakteriengeißeln. Sie zeigen deutliche Übereinstimmung in der Feinstruktur, der festen Verbindung von helikaler Scheide und Geißelhaken sowie in der Fragilität ihrer Filamente; sie unterscheiden sich deutlich im Molekulargewicht der Flagellinmonomeren (43 000 bzw. 55 000). Zellen von R. lupini H 13-3 führen schnelle, vibrierende Translationsbewegungen aus. Mögliche Mechanismen der Bewegung komplexer Geißeln werden diskutiert.
    Notizen: Abstract Cells of Rhizobium lupini H 13-3 possess 5 to 10 peritrichously inserted complex flagella, which were analyzed by high resolution electron microscopy and by optical diffraction. The flagellar filament has a diameter of 160 Å; it consists of a cylindrical core (diameter approximately 110 Å) surrounded by three close-fitting bands of a helical sheath. The helical bands are 49 Å wide, separated by axial intervals, 49 Å wide, and run at an angle of 31°. Complex filaments consist of a 43 000-dalton protein representing the core and the helical sheath. These originate from the proximal hook, which has a diameter of 150 Å and a length of 600 to 800 Å. The diffraction analysis of the hook showed a helical arrangement of globular subunits forming a surface of 5 parallel “small-scale” helices (pitch-angles 29° and 33°, respectively), each carrying almost 11 subunits per period. The complex flagella of R. lupini H 13-3 and Pseudomonas rhodos [Schmitt, et al.: J. Bact. 117, 844–857 (1974)] represent a novel type of bacterial flagella. There is agreement in their fine structures, in the intimate connection of the helical sheath and the core, and in the fragility of their filaments. Thery are clearly distinguished by the molecular weights of their flagellin monomers (43 000 and 55 000, respectively). Cells of R. lupini H 13-3 show fast, vibrating, translational motions. Possible mechanisms of complex flagellar motion are discussed.
    Materialart: Digitale Medien
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  • 15
    ISSN: 1432-072X
    Schlagwort(e): Bdellovibrio bacteriovorus ; Spirillum serpens ; Freeze Fracture ; Electron Microscopy ; Ultrastructure ; Membrane Damage ; Organismic Associations
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The freeze-fracture technique and electron microscopy have been used to demonstrate that localized damage is inflicted upon the cytoplasmic membrane of Spirillum serpens VHL within 20 to 30 min after the start of its association with Bdellovibrio bacteriovorus 109D. This damage is not observed in uninfected Spirillum cells, nor in infected cells within the first 10 min. This damage takes the form of a “blister” which, when viewed stereoscopically in electron micrographs, is seen to project toward the interior of the Spirillum cell. Shortly after its formation, the blister becomes elaborated into a series of ridges which may assume forms ranging from an elaborate spiral to a series of loops or knots. The formation of a blister is shown to involve both the inner and outer leaves of the membrane bilayer, and evidence is presented to indicate that the blister site corresponds to the site of attachment of the Bdellovibrio cell. The hypothesis is proposed that this ultrastructural damage is the cytological basis for the controlled and localized leakage through the cytoplasmic membrane into the periplasmic space of the Spirillum cell at locations adjacent to the Bdellovibrio cell. It is suggested that this localized membrane damage may be the ultrastructural basis for the high efficiency with which bdellowvibrios are known to incorporate cytoplasmic materials from the other bacteria in whose periplasmic spaces they develop.
    Materialart: Digitale Medien
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  • 16
    Digitale Medien
    Digitale Medien
    Springer
    Archives of microbiology 100 (1974), S. 307-328 
    ISSN: 1432-072X
    Schlagwort(e): Citrate Lyase ; Subunit Structure ; Electron Microscopy ; Reaction Inactivation ; Rhodopseudomonas gelatinosa ; Phototrophic Bacteria
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract 1. Citrate lyase (EC 4.1.3.6) from Rhodopseudomonas gelatinosa has been purified to homogeneity by protamine sulfate fractionation, chromatography on DEAE-Cellulose and gel filtration. The final enzyme preparation had a specific activity of 138 units per mg of protein and was purified 43-fold over the crude extract. Analysis of citrate lyase by sedimentation equilibrium experiments and gel filtration gave molecular weights of 530000 and 560000, respectively. 2. Electron microscopic investigations of negatively stained enzyme molecules and image analysis showed that citrate lyase is composed of six large and six small subunits; they are arranged in two hexagonal rings lying face to face, each containing, in alternating sequence, three large and three small subunits. The enzyme molecule is 160 Å in diameter and about 100 Å thick. 3. Treatment with sodium dodecylsulfate and mercaptoethanol dissociated citrate lyase into three proteins. Protein III (small subunit) had a molecular weight of 30000 and contained the pantothenate; protein II (large subunit) had a molecular weight of 61000; protein I (M r =97000) was probably an aggregate of II and III. 4. Based on the results obtained a model of citrate lyase was constructed. 5. Purified citrate lyase was obtained from R. gelatinosa in a deacetylated and largely oxidized form. The enzyme was activated by reduction with dithiothreitol (3 mM) and subsequent acetylation with acetic anhydride (1.75 mM). 6. The enzyme was subject to reaction inactivation, the extent of which depended on the concentration of Mg2+.
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  • 17
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 30 (1974), S. 271-276 
    ISSN: 1432-0533
    Schlagwort(e): Intracranial Teratoma ; Electron Microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A massive congenital benign teratoma grossly replacing the cerebral hemispheres has been examined by light and electron microscopy. The tumor contained tissues derived from all three germ layers. The cerebellum showed morphological features suggesting a state of maturation equivalent to that of 20 to 25 weeks of gestation. The tumor is discussed in the light of present theories on the pathogenesis of teratomas.
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  • 18
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 30 (1974), S. 315-328 
    ISSN: 1432-0533
    Schlagwort(e): Human Adenovirus Type 12 ; Sprague-Dawley Rats ; Intracerebral Inoculation ; Medulloepitheliomatous Neoplasm ; Giant Tumor Cells ; Electron Microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Solid medullary brain and spinal cord neoplasms developed in all 10 offspring of an outbred Sprague-Dawley rat, between 37 and 99 days after a single postnatal (within 24 hrs) inoculation of 0.05 ml of human adenovirus type 12, 103.5–104.5 TCID50 HeLa cells/0.1 ml in the left frontal lobe. Seven rats developed multicentric neoplasms in both hemispheres and in peri-aqueductal areas of the brain stem, one of which was associated with an incipient spinal cord tumor in the sacral segment. One rat developed a solid tumor involving the right parieto-occipital region. The remaining two cases were solid spinal cord tumors arising from the dorsal half of the thoracolumbar segments. The remarkably uniform microscopic appearance was designated as a counterpart of human embryonic neuronal neoplasms. Characteristic neuronal and multinucleated giant cells emerged throughout the tumor tissue with argentaffine, neurofibril-like cytoplasmic expansions and a unique cilium (a 9+0 pattern of tubules) associated with a pair of centrioles. This cilium morphology was also a hallmark of the majority of tumor cells that formed characteristic pseudorosettes. The occasional emergence of two sets of cilia and centrioles in monstrous cells suggested probable modes of cytogenesis in relation to cessation of abnormal cell division.
    Materialart: Digitale Medien
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  • 19
    ISSN: 1432-0533
    Schlagwort(e): Myxopapillary Ependymoma ; Tissue and Organ Culture ; Electron Microscopy ; Basement Membrane
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Explants of a myxopapillary ependymoma were grown on collagen-coated coverslips and in organ culture systems using gelfoam sponge matrices and Millipore filter platforms. The tumor cultured on collagen-coated coverslips initially exhibited the cytologic features of simple uni- and bipolar glial cells and later developed an epithelial-like pattern. Delicate branching of argyrophilic cell processes was demonstrated in Bodian preparations. In organ cultures, the tumor architecture was well preserved for approximately 4 weeks, and mitotic figures were present. Invasion of the sponge foam matrix was seen. Later cultures demonstrated progressive perivascular sclerosis and hyalinization. By electron microscopy, the tumor cells in organ culture systems retained the major fine structural characteristics of the original neoplasm up to 27 daysin vitro. The most striking feature in the late stages was the extensive increase and reduplication of basement membrane material, which appeared related to the increase of collagen fibrils in the extracellular space.
    Materialart: Digitale Medien
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  • 20
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 27 (1974), S. 43-53 
    ISSN: 1432-0533
    Schlagwort(e): Oncocytes ; Adenohypophysis ; Pituitary Adenoma ; Secretory Granules ; Electron Microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A light and electron microscopic study was undertaken on 3 surgically removed non-tumorous adenohypophyses and 16 pituitary adenomas. Numerous oncocytes have been found in 2 non-tumorous adenohypophyses and in 6 pituitary adenomas including 1 chromophobe adenoma which was composed almost exclusively of oncocytes. Thus, it seems that the occurrence of oncocytes in the anterior pituitary cannot be considered a rare finding. The distinctive feature of oncocytes is the abundance of mitochondria in their cytoplasm. This alteration can be so extensive that the entire cytoplasm is filled with mitochondria leaving only a small area for the remaining cytoplasmic organelles. Oncocytes arise from adenohypophysial cells. This transformation is gradual and is not restricted to one particular cell type. In the early phases of development of oncocytes the secretory granules are well preserved. Thus, hormone secretion is presumably maintained. It seems conceivable, however, that in the more advanced phases of evolution of oncocytes, when the secretory granules decrease in number, hormone production is diminished or stopped. Further investigations are, however, required to elucidate in detail the functional activity of oncocytes. It remains to be established whether mitochondrial accumulation is principally due to increased formation or delayed breakdown. As some mitochondria show signs indicating division it appears that multiplication of mitochondria is the underlying mechanism resulting in their significant increase. However, the possibility cannot be excluded that the life span of mitochondria is prolonged and mitochondrial longevity plays an important role in causing transformation of adenohypophysiocytes into oncocytes.
    Materialart: Digitale Medien
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  • 21
    ISSN: 1432-0533
    Schlagwort(e): Neuroaxonal Dystrophy ; Infantile Autonomi Nervous System ; Electron Microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The autonomic nervous system is studied by electron microscopy for the first time in two siblings born of North African consanguineous parents and affected by infantile neuroaxonal dystrophy. The changes already reported in dystrophic axons of the central and peripheral nervous system, are seen in the myenteric plexus of rectum mucosa. The authors stress the diffuse involvement of the nervous tissue in this degenerative disorder of still unknown nature.
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  • 22
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 28 (1974), S. 331-341 
    ISSN: 1432-0533
    Schlagwort(e): Craniopharyngioma ; Tissue Culture ; Electron Microscopy ; Enzyme Histochemistry ; Keratine ; Enamel ; Rosenthal Fibers
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Electron optical and enzyme histochemical investigations carried out on four craniopharyngiomas and their tissue cultures demonstrated that the tumour elements are keratinizing epithelial cells, plenty of tonofilaments, glycogen granules, mitochondria and desmosomes. Their ultrastructural and histochemical characteristics are the same in every part of the tumour (solid; cystic; “adamantinoma-like”). In the keratinizing cells, the reactions for non-specific esterases were high positive. The ultrastructural characteristics of the tumour cells grownin vitro are the same as thosein situ; the cells remain attached to one another by desmosomes and retain their capacity to produce keratine. This therefore seems to be a primary characteristic of the tumour cells and not a secondary dysmetabolic disturbance. Calcium was found onlyin situ. That the tumour cells may produce enamelin situ seems to be possible, but it could not be confirmed with certainty. The glial proliferation which is always presentin situ, is reactive and not neoplastic; thein vitro new built cell colonies consist only of epithelial elements.
    Materialart: Digitale Medien
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  • 23
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 29 (1974), S. 45-55 
    ISSN: 1432-0533
    Schlagwort(e): Experimental Neural Tumours ; Ethylnitrosourea ; Electron Microscopy ; Lysosomes ; Acid Phosphatase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A single intravenous injection of 30 mg of N-ethyl-N-nitrosourea per kg of body weight was administered to pregnant BD-IX rats on the 15th day of gestation. The neural tumours which developed in 97.5% of the offspring were gliomas and schwannomas. The demonstration of acid phosphatase in the neoplastic and reacting cells of these tumours was carried out at fine structural level. The enzyme activity was localised in lysosomes and in the innermost cisternae of the Golgi complexes. High acid phosphatase activity was related not only to degeneration, necrosis and phagocytosis but also to cellular differentiation and anaplasia.
    Materialart: Digitale Medien
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  • 24
    ISSN: 1432-0533
    Schlagwort(e): Steele-Richardson-Olszewski Syndrome ; Progressive Supranuclear Palsy ; Neurofibrillary Tangles ; Electron Microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The neurofibrillary tangles found in the neurons of a case of Steele-Richardson-Olszewski syndrome were studied by electron microscopy. Both the flame-shaped and globose type of tangles were present. The neurofibrillary tangles were composed of bundles of straight tubules measuring approximately 150 Å in diameter. This ultrastructural appearance of the tangles in Steele-Richardson-Olszewski syndrome is different from the appearance of tangles found in other neurological disorders and is probably indicative of intraneuronal accumulation of a new type of fibrous protein.
    Materialart: Digitale Medien
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  • 25
    ISSN: 1432-0533
    Schlagwort(e): Polyneuropathy Associated with Adie's Syndrome ; Sural Nerve ; Electron Microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The sural nerve of a woman of 35 with chronic polyneuropathy and Adie's syndrome was examined by electron microscopy. Myelinated nerve fibres were absent and there was marked reduction in the number of unmyelinated fibres. Onion bulb formation was not observed. Collagen fibres occupied the intercellular spaces.
    Materialart: Digitale Medien
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  • 26
    ISSN: 1432-0533
    Schlagwort(e): Experimental Neural Tumours ; Ethylnitrosourea ; Electron Microscopy ; Thiamine Pyrophosphatase ; Adenosine Triphosphatase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The fine structural localisation of thiamine pyrophosphatase and adenosine triphosphatase was carried out in gliomas and schwannomas induced transplacentally by N-ethyl-N-nitrosourea. The activity of thiamine pyrophosphatase was observed in the Golgi complexes and appeared to be directly related to cellular differentiation and reactive changes. The Mg2+-dependent adenosine triphosphatase was localised at the cell membrane, in the pinocytotic vesicles of various cells and in the basement membrane of some capillaries. This enzyme, showing high activity in differentiated cells, indicated the activity of membrane-bound cellular transport.
    Materialart: Digitale Medien
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  • 27
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 29 (1974), S. 211-222 
    ISSN: 1432-0533
    Schlagwort(e): Experimental Gliomas ; Ethylnitrosourea ; Electron Microscopy ; Virus-like Particles
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Two unusual, intracytoplasmic structures, resembling viruses, are described in experimental gliomas which were induced transplacentally on the 15th day of gestation in BD-IX rats by a single intravenous injection of 30 mg of N-ethyl-N-nitrosourea per kg of body weight. These structures are tubules within the lumen of the endoplasmic reticulum and large coated vesicles in the Golgi region. The tubules are of indeterminate length and have inner and outer walls of 9–11 nm and 20–22 nm respectively. The large coated vesicles are 80–90 nm in diameter and their outer surface is covered by regular, equidistant spikes of 12–15 nm in length. The vesicles are closely related to the Golgi complexes, from which they appear to originate. The intracisternal tubules and large coated vesicles share certain morphological features both with viruses and with normal cell organelles. The origin and significance of these structures are discussed.
    Materialart: Digitale Medien
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  • 28
    ISSN: 1432-0533
    Schlagwort(e): Jimpy Mouse ; Electron Microscopy ; Mouse Mutant ; Myelination ; Axonal Growth
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A quantitative study of the myelination and axonal growth in the corpus callosum and posterior columns of the spinal cord in the Jimpy mouse gave the following results: The reduction in the number of myelinated fibers is much more important in regions with late myelination, e.g. corpus callosum and pyramidal tracts than in the previously myelinated fascicles of Goll and Burdach. There is an important delay in the increase in volume of axons particularly within the structures of late myelination. The importance of the lacking axonal growth in relation to myelination is discussed.
    Materialart: Digitale Medien
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  • 29
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 30 (1974), S. 145-154 
    ISSN: 1432-0533
    Schlagwort(e): Aseptic Meningitis ; Atheromatous Material ; Hypersensitivity ; Electron Microscopy ; Macrophages ; Pia-Arachnoid ; Granuloma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary 500 mg of sterile pooled human atheromatous material was injected into the cisterna magna of 6 mongrel dogs. Repeated cisternal punctures were done at various intervals until sacrifice from 1 day to 28 days following injection. CSF was obtained for cell count, sugar, protein and analysis in the Technicon 6/60 which measured 14 additional chemical and enzymatic variables. All 6 animals showed a prompt cerebrospinal fluid (CSF) pleocytosis which largely subsided during the first 2 weeks after injection. Increased CSF protein content developed more slowly, but was more prolonged than the pleocytosis. There was a variable decrease in CSF sugar and increase in CSF lactate dehydrogenase, calcium and inorganic phosphorous. Light and electron microscopic studies showed an intense acute inflammatory reaction with marked phagocytosis of the foregin material, probably by arachnoidal cells and moderate edematous changes in the astrocytic processes at the site of injection. During the first 2 weeks after the injection the inflammatory reaction became chronic and the edematous changes in the medulla subsided.
    Materialart: Digitale Medien
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  • 30
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 30 (1974), S. 175-181 
    ISSN: 1432-0533
    Schlagwort(e): Reacting Astrocytes ; Phagocytosis ; Experimental Gliomas ; Ethylnitrosourea ; Electron Microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The fine structure of reacting astrocytes in experimental gliomas has been described. These tumours were induced transplacentally by 30 mg of N-ethyl-N-nitrosourea per kg of body weight injected into the tail vein of pregnant BD-IX rats on the 15th day of gestation. In tumour-bearing animals astrocytes undergo striking morphological changes and show increased mitotic activity. Reacting astrocytes around gliomas display large, eccentric, irregular nuclei and the abundant cytoplasm contains an increased number of cell organelles. The most dramatic increase is in glial filaments: these form thick bundles at the periphery of the cells and in the processes which are frequently seen around demyelinated axons. Reacting astrocytes engulf and break down myelin sheaths: their remnants, lamellar inclusion bodies and lipid droplets, are present in the cytoplasm. Extravasated erythrocytes are also surrounded by and digested in reacting astrocytes. Numerous lysosomes could provide the necessary enzymes for the phagocytic activity of these cells.
    Materialart: Digitale Medien
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  • 31
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 30 (1974), S. 155-173 
    ISSN: 1432-0533
    Schlagwort(e): GM1-Gangliosidosis ; Glycoproteins ; β-Galactosidase ; Lysosomal Disease ; Electron Microscopy ; Genetics of GM1-Gangliosidosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Post-mortem studies on a 6-year old boy with GM1-gangliosidosis, Type II revealed no evidence of accumulation of residual bodies nor of gangliosides or glycoproteins in liver and spleen. In brain tissue the ganglioside GM1 accounted for 70% of the ganglioside fraction and ganglioside-NANA was increased 3.6 fold over controls. In addition, the brain tissue contained large amounts of glycoprotein, glycoprotein derived galactose being increased 2.5 times. The neuronal accumulation of tertiary lysosomes exhibited a characteristic distributional pattern: in general the large neuronal perikarya were more consistently involved with the exception of the motor cells of the cranial nerve nuclei, III, IV, and VI. In addition to characteristic MCB's, the nerve cells contained residual bodies with a granulo-floccular matrix, presumed to represent glycoproteins. The distribution of the mutant gene was studied among 30 blood relatives of the proband at risk and 6 carriers could be ascertained on the basis of a reduced leukocytic β-galactosidase activity. The partly purified enzyme from the patient's liver revealed 20% activity as compared to that of normal controls. All three fractions obtained by DEAE cellulose column chromatography exhibited markedly reduced activity at pH 3.6, but nearly normal activity at pH 6.6. The reduced activity corresponded to the B component of the enzyme as shown by electrophoretic separation. It is pointed out that this case cannot be diagnosed as “generalized gangliosidosis” for the process of ganglioside accumulation was restricted to nervous tissue.
    Materialart: Digitale Medien
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  • 32
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 30 (1974), S. 189-196 
    ISSN: 1432-0533
    Schlagwort(e): Lafore Bodies ; Polysaccharidosis ; Electron Microscopy ; Epilepsia ; Histochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Cerebral biopsies of three patients aged 22, 18 and 16 years with myoclonic epilepsy contained Lafory bodies. Two were a brother and sister of consanguineous parents. The Lafora bodies occurred in most neurons but not in glial cells. The ultrastructure of these bodies showed a fibrillar and granular material in the perikaryon and neuropile. In some neurons small Lafora bodies were delimited by a double membrane, suggesting that in early phases they have a membrene which disappears when they become more developed. Other non-specific neuron alterations are described. One of the cases presented in the liver PAS positive bodies of a structure different from the Lafora bodies.
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  • 33
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 28 (1974), S. 93-103 
    ISSN: 1432-0533
    Schlagwort(e): Hexachlorophene Intoxication ; Toxic Encephalopathy ; Optic Nerve Necrosis ; Cerebral Edema ; Status Spongiosus ; Electron Microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary This is the first report of neuropathologic findings following oral ingestion of hexachlorophene in the human. The patient was a 7 year old boy who accidentally ingested 45 ml (approx.) of pHisoHex (hexachlorophene).Toxic reactions included nausea, vomiting, anorexia, diarrhea, decrease in visual acuity, blurred vision blindness, somnolence and disorientation. He developed cardiac arrhythmia, fever, isoelectric EEG and finally respiratory and cardiac arrest 61 h after admission. Autopsy findings showed interstitial myocarditis, pneumonitis and acute bronchiolitis. The brain was edematous. Light microscopy revealed mild diffuse vacuolization of white matter, occasional neuronal degeneration, most prominent on deepest layers of the visual cortex. Disintegration of myelin sheaths and necrosis of axon cylinders were present throughoutoptic pathways. Electron microscopy revealed large, empty extracellular and intramyelinic spaces formed by splitting and separation of the myelin lamellae. These changes are known to occur in experimental animals intoxicated with hexachlorophene, triethyltin, isonicotinic acid hydrazide and cuprizone. However, with respect to hexachlorophene, the localization of lesions to be optic pathways appears to be dependent upon an oral route of administration.
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  • 34
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 27 (1974), S. 1-10 
    ISSN: 1432-0533
    Schlagwort(e): Leprosy ; Lepromatous ; Axonal Bacillation ; Schwann Cells ; Electron Microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary M. leprae bacilli in nerves of 3 patients with lepromatous leprosy were found in the axoplasm of myelinated and unmyelinated nerve fibers. Axonal bacillation occurred in as much as 2% of myelinated axons. Bacilli within Schwann cells were a more common finding in lepromatous leprosy that intra-axonal bacilli. Intra-axonal bacillation probably represents a late stage phenomenon in lepromatous leprosy. Intra-axonal bacilli may contribute to the dissemination of leprosy by migration of bacilli within the axon, and may contribute directly to nerve fiber destruction.
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  • 35
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 27 (1974), S. 69-82 
    ISSN: 1432-0533
    Schlagwort(e): Chronic Nerve Compression ; Median Nerve ; Guinea-Pig ; Electron Microscopy ; Degeneration ; Regeneration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In guinea-pigs with chronic median nerve compression at the wrist the electron microscopic changes at level of the lesion and both proximal and distal to it have been studied. At the level of the lesion in animals with prolonged motor latency there was a loss of large myelinated fibres. Remaining large fibres had disproportionately thin myelin sheaths or were demyelinated. Regenerating clusters containing myelinated fibres were present. Evidence of degeneration and regeneration of unmyelinated fibres was present in the more severely affected nerves of this group. Distal to the wrist myelinated fibre density recovered, with regenerating clusters and many axons having disproportionately thin myelin sheaths. Midforearm and upper arm levels were normal. In nerves in which no muscle response to electrical stimulation could be recorded in the palm, a few fibres devoid of myelin remained at the wrist. Immediately proximal to it myelinated fibres were rare, the main feature being Schwann cells containing axons devoid of myelin some of which were degenerating. Degeneration of myelinating fibres within regenerating clusters was seen. At the mid-forearm level large myelinated fibres were reduced and increased numbers of regenerating clusters were seen. Evidence of regeneration of unmyelinated fibres was found. The upper arm was normal.
    Materialart: Digitale Medien
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  • 36
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 27 (1974), S. 247-256 
    ISSN: 1432-0533
    Schlagwort(e): Werdnig-Hoffmann's Disease ; Electron Microscopy ; Muscle Biopsy ; Myotube-like Cells
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary An ultrastructural study was carried out on muscle biopsies of 7 children with Werdnig-Hoffmann's disease. The muscle fibres were classified into 3 categories: 1. Muscle cells of normal diameter without any distinct or only slight changes. 2. Small muscle cells with a large central nucleus with the appearance of myoblast at a later stage of development. 3. Cells resembling myotubes containing in a common basement membrane two to four cells at different stages of maturation. Myoblast and myotube-like cells seemed to resemble foetal muscle fibres. Such fibres appear to represent an arrest in maturation rather than muscle atrophy.
    Materialart: Digitale Medien
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  • 37
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 333-343 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: One of the main reasons for immobilizing an enzyme is to enable its reuse, or continuous use, in a reactor. Consequently immobilized enzyme stability is an important factor in enzyme reactor design. The performance of the reactor will decrease if during operation the support material disintegrates into smaller particles that pass out of the reactor system.When β-galactosidase is immobilized by covalent attachment to AE-cellulose, the smaller particles have a higher activity. After subjection of the immobilized enxyme to a shear stress the average particle size decreases and the total enzymic activity increases. A loss of small particles from the reactor, although constituting a small weight percent loss of support, will result in a disproportionately large loss in activity. The relevance of these observations to reactor performance is discussed.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
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  • 38
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 345-360 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: A tubular membrane reactor offers many advantages over a solid wall reactor to carry out an enzyme catalyzed reaction. With proper membrane selectivity, the product, may be separated from the reacting stream and the enzyme recycled for continuous reuse. In most cases, enzyme reuse contributes to the economic feasibility of a continuous enzyme catalyzed process. Furthermore, the efficiency and performance of a membrane reactor is greater than that of a solid wall reactor.Continuous hydrolysis of starch by the enzyme β-amylase, carried out in a commercially available tubular membrane unit, is studied at different starch and enzyme concentrations for a given system pressure and inlet flow rate. Results show that the performance of the membrane reactor is in all cases greater than that of the solid wall reactor. A steady state in performance of permeation rate is, however, not reached by the membrane reactor, which shows a continuous decline within the periods examined in this study. This decline is caused in part by the aging of the starch solution, but mostly by the formation of a concentrated, or gel, layer at the membrane surface. This appears to be the main limiting factor for this process since the decline in reaction and permeation rate results in a severe decrease in the amount of maltose in the permeate.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
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  • 39
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 371-383 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The disintegration of baker's yeast (Saccharomyces cerevisiae) by a high pressure homogenizer, to a pressure of 25,000 psi. (172.37 MNm-2) is described, together with details of the methods of measurement used to obtain information on the valve movement and pressure transients. The theory of the mechanism of cell disintegration is discussed.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
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  • 40
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 279-284 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
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  • 41
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 285-287 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 1 Tab.
    Materialart: Digitale Medien
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  • 42
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 757-770 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The mixing of the anaerobic digester contents significantly influences the efficiency of this operation; in particular, hydraulic dead zones are extremely detrimental to the reaction kinetics involved in anaerobic digestion. An analysis of the relative importance of thermal fluid movement in the digester to those caused by fluid inflow and outflow is presented. As an example, these principles are applied to a digester at the South Bend Wastewater Treatment Plant. Experimental measurements, which have general applicability for the measurement of digester mixing volume, confirm the theoretical conjectures. Various types of optimizations can be attempted on this mixing operation. One such optimization applied to gas lift mixers, as employed in the South Bend Treatment Plant, is illustrated.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
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  • 43
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 807-826 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Activated sludge is a widely used aerobic biological waste-water treatment process. A rational approach to least cost design of an integrated system is described which includes the following processes: activated sludge reactor, final settling tanks, gravity thickening, and aerobic sludge digestion. Both capital and operation and maintenance costs are considered. Biological reactor design is based on microbial kinetic concepts and continuous culture of microorganisms theory. Biological solids retention time (θc) is utilized as the primary independent design variable to which system performance is related, e.g., effluent quality, ammonia oxidation, and excess sludge production. Liquid-biomass separation is based on the batch flux technique, a rational approach to design of gravity separators (final settling tanks). Trade-offs among reactor volume, clarifier size, recycle pumping capacity, thickener capacity, digester volume, air requirements, and sludge production are discussed. The optimum design is taken as the combination of these parameters within the acceptable design domain, determined by effluent quality criteria, that results in minimum cost. While the method described is general, design of a given treatment system depends on availability, from lab or pilot studies, of system specific numerical values for biological growth coefficients and biomass setting characteristics. A design example illustrates the approach.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
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  • 44
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 863-865 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
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  • 45
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 789-805 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: It has been demonstrated that ozone dosages of 0.06 lb and 0.78 lb per pound of lignin can reduce the optical density (in the visible range) of the latter by 82% and 92%, respectively. The reduction in color is accompanied by a shift in the molecular weight distribution of lignin from a broad peak of between 20,000 and 70,000 to lower molecular weight, species including substantial amounts possessing a molecular weight of 1000 or less. The cost of decolorizing a typical kraft paper bleach effluent is estimated to be under 50¢/1000 gal which compares favorably with competitive decolorizing processes. Lignin ozonation results in the production of a series of decolorized products which can serve as the sole source of carbon for a variety of microorganisms. Feasibility studies indicated that at least 40% of the ozonated material can be transferred into microbial biomass (protein) as well as other products of commercial interest such as fumaric acid and penicillin.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
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  • 46
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The consideration of fermentation principles in the treatment of industrial and sanitary waste waters leads to substantial process improvements. In particular, the rate of reaction can be improved by several fold by establishing the proper environmental conditions for microbial growth in a fermentation system. Recent work on the concentric cylinder air lift has shown it to be an economical fermentor with many advantages over conventional fermentors. An attempt to improve the economical performance of this system led to the development of the thin channel rectangular air lift fermentor. This was based upon a theoretical analysis of performance parameters. The analysis indicates decreased bubble coalescence, increased bubble entrainment, decreased power costs, increased mass transfer coefficients, and decrease capital costs. Experience using a prototype thin channel rectangular air lift system with sanitary and industrial waste-water treatment systems has demonstrated exceptionally high rates of BOD removal at low operating and capital costs.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 47
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1261-1272 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: A tubular loop batch fermentor has been designed and constructed, and was found to behave in a similar manner to a conventional stirred tank reactor. It appeared that foaming could be greatly reduced as no air ever encountered the impeller. The fluid mechanics of pipe flow are considerably simpler than tank flow patterns. On this basis a design procedure for a large scale tubular fermentor was outlined, which had considerable advantages over the more complex scale-up problems of a tank fermentor.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 48
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1283-1297 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: System response data for step changes in input tracer concentration have been obtained for two different impeller agitated continuous flow mixing systems containing aqueous polysaccharide solutions. The vessel volumes were 1.6 and 10.9 liters. Polysaccharide concentration, dilution rate, and impeller speed were varied according to a plan devised using dimensional analysis and assuming that bulk motion is the predominant mass transport mechanism in the system. The data show that this is not true and that serious errors may occur if scale-up calculations are based on assuming that bulk motion predominates. Under the operating conditions used, perfect mixing was not observed.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 49
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1359-1372 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: A column reactor with an annular cross section was formed by rolling up DEAE cellulose paper and a screening spacer. Glucoamylase was attached by ion adsorption. For the spacer used, pressure drop was very low, suggesting that this form may be useful with feed streams that are not completely particle-free. Tests of this reactor at the high substrate concentrations characteristic of commercial reactors showed very little diffusional resistance, exhibiting zero-order behavior over most of the concentration range. At low concentrations, the reactor had an apparent “half-order” behavior caused by diffusional limitation in the paper. In this range, flow rate influenced the reaction rate, showing that mass transfer in the main stream also is a contributing factor in this range. Because of the high concentrations and the low Michaelis constant (0.0011 M) the reactor does not show first-order behavior, even at very high conversions. The design of a plant-scale reactor was formulated from these data. The increase in the quantity of enzyme necessary to compensate for the effects of diffusion was only a few percent.Two reactors were formed with sheets nonporous to the enzyme, binding the enzyme with cyanogen bromide after forming the reactor. The amount of enzyme bound was about one monolayer, and there appeared to be no diffusional limitations, even at low substrate concentrations.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 50
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1413-1418 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 51
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1433-1447 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: A high molecular weight intracellular enzyme of Bacillus brevis ATCC 9999 is released when the organism is disrupted by sonication of homogenization. However, both processes also degrade the enzyme. Assays for protein release and specific enzymatic activity of the released protein indicate that both release and degradation can be represented by first-order kinetic models. Utilization of the difference between the kinetics of release and degradation allows optimization in the recovery of this enzyme for both the sonication and homogenization processes.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 52
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1565-1565 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 53
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Several microorganisms having higher L-histidine ammonia-lyase activity were immobilized into polyacrylamide gel lattice. The yield of enzyme activity by immobilization was highest in Achromobacter liquidum IAM 1667. As A. liquidum has urocanase activity, the cells were heat-treated at 70°C for 30 min to inactivate the urocanase.Enzymatic properties of the immobilized A. liquidum cells were investigated and compared with those of the intact cells. No difference was observed between the pH activity curve and optimal temperature for the intact and immobilized cells. The permeability of substrate or product through the cell wall was increased by immobilization of the cells.When an aqueous solution of 0.25M L-histidine (pH 9.0) containing 1mM Mg2+ was passed through a column packed with the immobilized A. liquidum cells at a flow rate of SV = 0.06 at 37°C, L-histidine was completely converted to urocanic acid. The L-histidine ammonia-lyase activity of the immobilized cell column was stable over 40 days at 37°C. From the effluent of the immobilized cell column, Urocanic acid was easily obtained in a good yield.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 54
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1675-1680 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 55
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1681-1687 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 56
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 21-39 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: An apparatus is described which is designed for preparative freeze concentration experiments by the technique of normal freezing. It has a capacity of approximately 22 liters distributed over twelve vessels. The influence of various geometrical and chemical parameters such as stirring speed, crystallization rate, and sample composition on the normal freezing of protein solutions are discussed. For dilute protein solutions (〈0.1%) the concentration factor generally was 8- to 10-fold with recoveries of 90-100 percent. With higher protein concentrations and at ionic strengths higher than approximately 0.05, the recovery was decreased. No loss of activity was detected when concentrating enzyme solutions.
    Zusätzliches Material: 14 Ill.
    Materialart: Digitale Medien
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  • 57
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 555-557 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 58
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 567-577 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: β-Amylase (EC 3.2.1.2), obtained from barley, was chemically attached to a crosslinked copolymer of acrylamide-acrylic acid using a water-soluble carbodiimide. The derivative showed 23% β-amylase activity in relation to that of free enzyme with a coupling yield of 40% based on the amount of added β-amylase. In order to find optimal coupling conditions, the effect of pH and different carbodiimide concentrations was investigated. The enzymic activity associated with different β-amylase concentrations was further outlined. A slightly increased operational stability for the enzyme upon immobilization was observed. Markedly improved operational stability has been obtained by coupling in the presence of reduced glutathione of bovine serum albumin.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 59
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 159-168 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Glucose oxidase (EC 1.1.3.4, from Aspergillus niger) has been entrapped in a crosslinked 2-hydroxycthyl methaerylate gel containing 20% poly(vinyl pyrrolidone). The kinetic behavior and thermal stability of the entrapped enzyme were found to closely approximate that of the free enzyme. The entrapped glucose oxidase shows a broadened pH profile which is attributed to a buffering effect of the gel. Stability of gel entrapped glucose oxidase is extremely good at room temperature, suggesting a variety ofanalytical and control uses for this system.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 60
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 275-277 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 1 Tab.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 61
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 289-291 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 1 Tab.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 62
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 251-260 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The effects of wall growth are described for a mixed methane-utilizing bacterial population growing in both batch and continuous culture. These effects are similar to those predicted previously by a theoretical analysis (Topiwala and Hamer, 1971).
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 63
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: A new and simple method for immobilization of enzymes by the aerobic radio-polymerization of acrylamide was developed. Irradiation treatment of acrylamide in the frozen state produces a spongy immobilized enzyme membrane without the addition of carriers. Aerobic polymerization yields of acrylamide in the frozen state were increased by the addition of starch and also by lyophilization.Glucose oxidase (activity recovery was 12.3-33.7%), invertase (69.2%), D-amono acid oxidase (25.0-70.5%), aminoacylase (39.2-43.7%), mold α-amylase (18.0%), malt β-amylase (4.1%), glucoamylase (6.5%), alkaline protease (5.3%), and neutral protease (10.5%) were immobilized by this method. Invertase entrapped by this method had a wider optium pH range and was active at higher temperatures.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
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  • 64
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 65
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 859-862 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 66
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 881-896 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Spirulina maxima, a high protein alga, was grown in effluents from the London municipal waste treatment plant. Optimum growth conditions were developed, the composition of algae and the removal of nitrogen and phosphorus in effluents were studied. The advantages of this process in tertiary waste-water treatment and the quality of the single cell protein were investigated.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 67
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 997-1003 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 68
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1025-1044 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Studies were carried out on the production of Sindbis, influenza and vesicular stomatitis viruses in suspensions of chicken embryo and rat embryo cells. The yield of Sindbis virus in chicken embryo cell suspensions was independent of the multiplicity of infection over the range 0.0001 to 0.01 although reduction in multiplicity caused a delay in virus production. With influenza virus the use of higher multiplicities gave increased virus yields possibly due to the very slow production at low multiplicities. In both monolayer and suspension cultures of chicken embryo cells addition of serum or use of media richer than minimum essential medium (Eagle) had little effect on Sindbis virus production, but if the glucose were omitted the virus yield was markedly reduced. In cell suspensions, a marked reduction in virus yield occurred if infection were delayed more than 24 hr after cell preparation whereas in monolayers the delay of infection allowed cell propagation and hence a higher yield of virus. It was also shown that vesicular stomatitis virus can be produced in chicken embryo cell suspensions, and that rat embryo primary cell suspensions can be used to prepare both Sindbis and vesicular stomatitis viruses. Sindbis virus obtained from chicken embryo cell suspensions was purified by polyethylene glycol precipitation and sucrose density gradient centrifugation and shown to contain only those proteins previously identified as viral, without any contamination from chicken cell proteins. The relative ease and economics of virus production by cell suspension and monolayer methods is compared.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
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  • 69
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1081-1093 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Numerical solutions to the equations describing simultaneous mass transfer and enzymic reaction within porous spherical particles have been used to examine the effect of enzyme content and other parameters on the kinetic behavior of immobilized enzymes. These solutions have also been compared with experimental data for enzymes immobilized to DEAE-cellulose particles. The influence of particle size and enzyme content on catalyst design is discussed.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 70
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1123-1133 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Degradation of UNA by endogenous RNase in cell suspensions of Saccharomyces cerevisiae was found to be achieved by mechanical disintegration followed by incubation in the presence of NaCl. The incubation parameters pH, temperature, time, and concentration of NaCl were investigated. Protein concentrates with a low content of RNA were obtained by precipitation of the incubated suspensions and separation of the degradation products.On a pilot plant scale the incubation was performed at 50°C and pH 5.6 in the presence of 3% NaCl for 20 min. Kilogram quantities of protein concentrates containing 1.4% RNA and 8.2% nitrogen were obtained. The RNA reduction and the nitrogen yield was 85 and 60%, respectively. The yield of amino acids was about 75%. The process described can probably be applied for large-scale production.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
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  • 71
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1213-1225 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: When the effect of catabolite repression is eliminated Saccharomyces cerevisiae prefers an aerobic metabolism. The potential for completely aerobic catabolism exists even in circumstances where its action is limited by the oxygen available. When the oxygen absorption in the medium is adequate, yeast uses a solely oxidative metabolism for energy-yielding reactions. The changes observed in the activity of malate dehydrogenase can be described as a function of two isoenzymes, both of which are affected by oxygen; the isoenzyme participating in the glyoxylate cycle shows variations in activity similar to that observed in isocitrate lyase. NAD-linked glutamate dehydrogenase activity roughly follows that of malate dehydrogenase and isocitrate lyase; in cultivations with the same growth rate the NADP-linked dehydrogenase is insensitive to the oxygen level. The cytochromes aa3, b, and c have a clear maximum at low oxygen tension, the most sensitive being cytochrome aa3. The imbalance between cytochrome c:oxygen oxidoreductase activity and the amount of cytochrome aa3, and the correlation observed between respiration rate and the activities of cytochrome c oxidase and NADH2:cytochroine c oxidoreductase are discussed. Methods used for estimation of cytochromes are compared.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
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  • 72
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: An electronic particle counter has been used to estimate the disintegration by freeze-pressing baker's yeast. A counter threshold level which just yielded the maximum count for intact cells was selected. The conductivity of the suspending medium was chosen such that maximum counts were obtained. Under these conditions, the electronic counts agreed well with the visual counts. At a certain threshold level the maximum count was obtained at a lower resistivity (higher conductivity) in the suspending solution with the freeze-pressed suspension than with untreated cells, indicating that damage to the permeability barrier may occur without disruntion of the cell envelope.Fresh baker's yeast cells do not behave as nonconducting particles. This has to be taken into account when volume determinations with electronic particle counters are performed.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
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  • 73
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1495-1506 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The soluble components in disintegrated cells of Saccharomyces cereivisiae have been characterized by means of extraction, centrifugation, dialysis, and gel filtration. The influence of alkali and heat treatment on the protein and RNA in the soluble fraction from disintegrated yeast cells and on functional properties of protein concentrates have been studied.After water extraction and centrifugation at 100000 g 42% of the nitrogen containing components of the disintegrated cells were recovered in the supernatant. By extraction at pH 11.5 an additional 31% of the nitrogen was solubilized. Half of the water-soluble nitrogen-containing components has a molecular weight lower than 5000. In the water- and alkali-soluble fractions about 80% of each amino acid was recoveredThe water-soluble protein was separated into 3 fractions by gel filtration on Sephadex G 200. The major portion of the protein had a molecular weight about 100,000. The amount of protein in this fraction was decreased after treatment at increasing pH and temperature. No degradation of protein to low molecular peptides occurred. The amount of RNA in the soluble fraction was only slightly influenced by alkali treatment and by heat treatment at pH 7.5 in the presence of 5% NaCl. RNA was not degraded to low molecular components of the treatments.The solubility of protein concentrates decreased after treatment at alkaline pH and after heat precipitation.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
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  • 74
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1529-1536 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: A simple system for the control of oxygen transfer in laboratory fermentation units has been devised. This system employs pure oxygen to elevate the driving force for oxygen transfer. In addition, the aeration is controlled in a closed loop manner in order to minimize total exit flow of the gas from the fermentor. Fermentation study using Bacillus stearothermophilus grown on n-dodecane at 55°C illustrates excellent carbon recovery as well as the ease of controlling oxygen transfer.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 75
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 419-422 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 76
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1103-1112 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: β-Galactosidase has been purified from an ammonium sulfate precipitate of E. coli strain ML308 by biospecific adsorption on a column of agarose gel substituted with p-aminophenyl-β-D-thiogalactopyranoside. The system described using a 1.8 liter column has a useful processing capacity of 3.8 × 106 units of β-galactosidase per 2 hr cycle. This corresponds to about 5 g of pure enzyme. An electromechanical timing device operates a set of six solenoid valves and carries out a preset program consisting of sample application, washing, and elation operations.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 77
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1113-1122 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Porous hollow cellulose fibers have been used to separate a nonflowing enzyme solution of alkaline phosphatase from a continuous flow of substrate. The porosity of the hollow fiber membrane allows the substrate and product to diffuse freely through the membrane while restricting the permeation of the enzyme. The resulting “immobilized” enzyme system has been shown to behave as a continuous reactor - converting p-nitrophenylphosphate to p-nitrophenol. By varying the concentrations, flow rate, etc., either diffusion or enzyme kinetics can be studied. The continual influx of product and removal of substrate at steady state allows the study of kinetics of relatively short half-life enzymes and unstable systems.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 78
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974) 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 79
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 41-59 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The growth of a mixed methane-utilizing culture in a continuous flow fermenter has been studied under both methane and oxygen limitation. Small additions of methanol have been shown to inhibit the methane-utilizing moiety in the culture and it has been shown that the Hyphomicrobium sp. in the mixed culture removes any inhibitory methanol. The interaction between the methane-utilizing Pseudomonas sp., and the Hyphomicrobium sp. has been explained and a model of the continuous mixed culture under oxygen limitation has been formulated. Qualitative predictions of transient phenomena by the model have been verified experimentally.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 80
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 119-134 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: L-Asparaginase has been attached by chemical means to the inner surface of nylon tubing. An experimental study has been carried out of the flow kinetics for such a system, asparagine solutions at various concentrations being passed through two lengths of tubing at various flow rates. Measurements were made of the concentration of the product ammonia at the tube exit, and of the rate of formation of ammonia, under the various conditions. Apparent Michaelis constants, Km(app), were some three orders of magnitude higher than the Km for the enzyme in free solution (∼13 × 10-6JM). The results were analyzed with respect to the theoretical treatment described in the preceding paper (Kobayashi and Laidler), three different methods being employed. It is concluded that at lower substrate concentrations and flow rates the reactions are largely diffusion-controlled, the enhanced Km(app) values being largely if not entirely due to the diffusion control; ionic strength studies showed electrostatic repulsion effects to be unimportant. At high concentrations and high flow rates (when the diffusion layer is of negligible thickness) the diffusional effects are minimized, and Km(app) approaches the true Km value for the immobilized enzyme.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 81
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 135-147 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: An α-galactosidase which will hydrolyze the oligosaccharides melibiose, raffinose, and stachyose has been immobilized on nylon microfibrils suitable for use in large flow-through reactors. This catalyst system is stable for many months, both under use and storage conditions. The immobilized enzyme behaves similarly to the enzyme in solution, characteristically exhibiting both product and substrate inhibition. The catalyst is prepared in situ and a large, 8-liter reactor has been made. The catalyst has been used to reduce the raffinose concentration in beet sugar molasses.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 82
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 231-250 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Evolutionary operation (EVOP) was used to experimentally investigate the optimum steady state operating conditions for a step aeration activated sludge waste treatment process. A laboratory scale two tank step aeration activated sludge unit with fixed total volume, total influent flow rate, recycle flow rate, and sludge wasting rate was employed. The volume ratio and flow rate ratio which minimized effluent chemical oxygen demand were determined. The results indicate that EVOP is a useful technique for improving the performance of biological processes.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 83
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 385-396 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Trypsin (EC 3.4.4.4) was immobilized in low yield on aminoalkylsilylated magnetite (Fe3O4). Better results were obtained when trypsin was immobilized by crosslinking with glutaraldehyde on magnetite. The preparation contained 36 mg protein/g magnetite and the enzyme retained 46% and 11% of esterase and proteolytic activity. Immobilized trypsin was more heat stable than trypsin. Invertase (β-D-fructofuranoside fructohydrolase, EC 3.2.1.26) was cross-linked on magnetite with glutaraldehyde in low yield due to the inactivation of the enzyme. However in the presence of 1% sucrose, the total activity recovered was 79% of the initial activity and the preparation contained 4.4 mg/g of active invertase. Immobilized invertase was less active than invertase when acting on oligosaccharides of the raffinose family. The immobilized enzymes could be easily recovered, from solutions or suspensions, magnetically.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
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  • 84
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 431-454 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: A general model of the kinetics of microbial growth has been developed involving the kinetics of incorporation of substrate into biomass and the maintenance energy requirements.Results obtained from batch cultures of the yeast Saccharomyces cerevisiae growing in synthetic media at pH 5.1 and 30°C permitted all biological parameters in the model to be calculated.Values obtained for these parameters were: maximum specific glucose uptake rate (μSm), 2.08 g/g biomass/hr; apparent Michaelis constant for glucose (KS), 0.1 g/liter (5.5 × 10-4M) apparent Michaelis constant for oxygen (KL), 1.4% O2 (3.2 × 10-6 M) quantitative index of the Pasteur effect (b), 4.9 × 10-4%-1 O2 (207 M -1). Under conditions of strongly substrate-repressed respiration the values obtained for YATP and P/O were constant over the course of the exponential phase of growth (YATP = 10.4 g biomass/mole ATP; P/O = 3 moles ATP/atom 0). Mass balances for aerobic and anaerobic cultures confirmed the results obtained form the generalized model. Results presented suggested the operation of a mechanism for regulating energy-yielding metabolism which involved an equilibrium between the systems of oxidative phosphorylation and dephosphorylation and was dependent upon the level of catbolite repression.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
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  • 85
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 501-511 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Invertase was entrapped in cellulose triacetate fibers and the properties of the insoluble derivative were studied. Fiber-entrapped invertase was found very stable under operating conditions. For some insoluble preparations a half-life value of 5,300 days was calculated; a sample of invertase fibers, continuously hydrolyzing sucrose, maintained unchanged its activity for five years. The activity displayed by invertase fibers was 15-65% of that of the free enzyme, depending on the amount of entrapped enzyme and on the porosity of the fibers. At very high substrate concentrations the activity of the entrapped invertase approximated to that of the free enzyme. The pH optimum for activity was around 4.5 for the free and entrapped invertase. The native and entrapped enzyme was unstable at temperatures higher than 35°C.The continuous hydrolysis of sucrose using invertase fiber was studied and the potential industrial application of entrapped enzyme is discussed.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
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  • 86
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 545-550 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 87
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 525-529 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 88
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 539-543 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 89
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 559-563 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 90
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 593-607 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: An immunoadsorbent process has been devised for removing serum hepatitis antigen (HAA), from blood, blood plasma, and plasma products.The immunoadsorbent complexes specifically with HAA and the complex is removed from the plasma by filtration. The complex is dissociated with 0.23M NH4OH. The immunoadsorbant is regenerated for further processing, while the purified HAA by-product my be used to produce more antibody in animals.The rate of complexing is such that HAA is reduced one log cycle each 2hr. Since available tests can only detect HAA to about 109 particles per ml, it is proposed that HAA negative plasma and plasma products can be processed to reduce HAA to a probability of less than one HAA particle per plasma pool.A gibbon injected with infectious commercial Factor IX that was subjected to the immunoadsorbent process showed no sign of infection after 8 months. However 14 weeks after injection with unprocessed Factor IX, the gibbon showed signs of infection.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 91
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 659-673 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The time course of release of intact labile material from cells by cavitating ultrasound is examined. Curves are presented which show the yield of intact subcellular components obtainable from cells as a function of sonication time for various values of the ratio of inactivation rate to release rate. The general cases where inactivation of released product is concentration dependent (chemical) and concentration independent (mechanical) are considered.For a flow system the time of attainment of equilibrium concentration of active product is analyzed as a function of flow rate, release rate, inactivation rate, and volume of chamber. Curves of optimal yields to be expected for batch and flow systems are presented. It is shown that sonochemical inactivation can be made negligible by sonication of high cell concentration suspensions.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
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  • 92
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 675-687 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Among the methods used for the rupture of cells by means of solid shear, the Hughes press is best known. It operates by forcing an aqueous suspension of cells previously frozen at -27°C under pressure through a narrow circumferential gap. The mode of action requires a knowledge of the isentropic compression of the solid phase and its possible involvement with a phase change from ice I to ice III. It is shown that the mechanical properties of the solid mixture are relevant. A model is proposed of the plastic flow for the geometry of the press and it is shown that cell breakage is proportional to the velocity of the plunger and inversely proportional to gap width.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 93
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974) 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 94
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1015-1023 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The CO2 mass balance for a suspension of algae cultivated in the region of neutral pH of the suspension on an open cultivation surface with a flowing suspension was assessed. From this balance an analytical expression for the course of free CO2 dissolved in the suspension along the flow of the suspension is obtained. Relations for the rate of CO2 decrease in the suspension and the utilization of CO2 supplied to the cultivation surface are derived.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
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  • 95
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1055-1068 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Films of highly polymerized collagen, prepared in industrial conditions, were chosen for surface covalent binding of enzymes because of their insolubility, mechanical resistance, proteic nature, hydrophilic properties and for their abundance in chemically activable —COOH. Untanned films, previously acid- methylated, were activated by acyl azide formation. After removal of reagents by repeated washing, the coupling of enzyme was performed by immersion of the activated film in the enzyme solutions (2 to 3 hr, 0°C). The procedure is particularly mild since the enzymes never come into contact with chemical reagents, and thus avoid all denaturing processes. All the enzymes tested were successfully bound: glutamate dehydrogenase, lactate dehydrogenase, malate dehydrogenase, aspartate aminotransferase, glutamate pyruvate transaminase, creatine kinase, hexokinase, trypsin, and urease. As tested with aspartate amino transferase, enzymatic activity remained constant for months (100% after 5 months) in spite of repeated use of the film at 30°C, washing and storage in buffer at 4°C between assays.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
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  • 96
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1161-1177 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Highly charged water-soluble conjugates of amyloglucosidase with a copolymer of ethylene-maleic acid or styrene-maleic acid were prepared and adsorbed on DEAE-cellulose and other cationic resins. Negatively charged enzyme conjugates were also obtained by means of succinylation. The polyanionic conjugates of amyloglucosidase adsorbed on the cationic carriers show higher temperature stability than the native enzyme adsorbed on the same carriers under the same experimental conditions. The insoluble enzyme conjugate-carrier complexes could be reused and retained their full activity while working continuously for three weeks. The application of the insoluble enzyme preparations with the above characteristics which could possibly satisfy the requirements for industry are discussed.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 97
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1507-1516 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Ribulose-1,5-diphosphate carboxylase from spinach has been bound to arylamine porous glass with a diazo linkage and to alklamine porous glass with glutaraldehyde. Stability at elevated temperatures and responses to changes of pH and ribulose-1,5-diphosphate, Mg2+, and dithiothreitol concentrations were not significantly different from the soluble enzyme, though stability at 4°C was somewhat improved.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
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  • 98
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1545-1547 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 99
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1557-1564 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 100
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1611-1631 
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Continuous fermentation of grape juice was studied in three basic kinds of nonmechanically stirred fermentors, classified according to the direction in which flow is applied against settling: upward-flow, slant-flow, and horizontal-flow.Fermentation kinetics were found to be zero-order, thus rate was directly proportional to cell density.Completeness of fermentation depends upon yeast characteristics (growth rate flocculation), fermentor geometry (settling depth, flow path length), and upon flow velocity.Fermentor analysis demonstrated that to achieve complete fermentation in the minimum juice holding time, efficient cell retention as well as rapid yeast growth and fermentation rates are required. Fermentor design and operation are discussed in the light of this analysis.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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