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  • Articles  (240)
  • Wiley-Blackwell  (240)
  • 1980-1984
  • 1965-1969  (240)
  • 1968  (240)
  • Biology  (240)
  • Energy, Environment Protection, Nuclear Power Engineering
  • 101
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    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 10 (1968) 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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  • 102
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    Biotechnology and Bioengineering 10 (1968), S. 89-98 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The foam separation technique of microflotation was studied using A. aerogenes as the test organisms. Gas flow rate, collector and alum (when used) concentrations, and frother dose were held constant. In contrast to E. coli, previously reported, A. aerogenes are removed using both lauric acid and laurylamine as the collectors without prior coagulation with alum. The removals are improved after coagulation, with laurylamine being the more efficient collector. In all cases the removals decrease upon increasing the pH above about 8.
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  • 103
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    Biotechnology and Bioengineering 10 (1968), S. 133-150 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The rate of dissolution and dehydration of CO2 in a liquid model system was investigated. Components in the model system established the main conditions which may exist, in the extracellular space of a microbiological culture liquid. The charge in voltage of a glass electrode was measured which indicated the formation of H+ ions in the H2CO3 ⇌ HCO3- H+ reaction. The rate of CO2 hydration increased with the increase of temperature from 0 to 40°C. Likewise the equilibrium of the reaction was shifted towards the forward reaction. Similar results were observed when the tip velocity of the impeller was increased. Data suggest that agitation promotes the dissolution of CO2 in the culture liquid through the reduction of gas-liquid film resistance in the diffusion of this gas. The rate of hydration of CO2 into the bulk of the liquid was independent of pCO2 above the surface of the liquid but depended on pCO2 in the gas bubble within the liquid. The concentration of HCO3- was, furthermore, influenced by the buffer components, buffer capacity, and the viscosity of the system. Since pCO2 and the HCO3- concentration in the extracellular space depend on both physical and chemical factors, the ventilation of a culture liquid necessitates both exhaust of CO2 from the gas bubbles of the culture broth and shift of the H2CO3 ⇌ HCO3- + H+ reaction towards the backward direction.
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  • 104
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    Biotechnology and Bioengineering 10 (1968), S. 233-237 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A method for the determination of total heat generation in a fermentation tank and overall heat-transfer coefficient at the cooling surface is outlined. These data, which are essential for the design of cooling systems, are measured during the actual fermentation by dynamic analysis of controlled temperature variations. Each experiment consists of two stages: one in which cooling is cut off, and one in which cooling is constant. The necessary temperature variation is so limited that, the course of the fermentation is not affected.
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  • 105
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    Biotechnology and Bioengineering 10 (1968), S. 877-889 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A survey of interactions of membrane filters with viruses has included 28 types of membranes, 4 types of enteroviruses, and 1 reovirus. Losses of these viruses in filtration, due to adsorption to the filter membranes, appear to be governed by three factors: the chemical composition of the filter membrane, the ratio of pore diameter to the diameter of the virus particle, and the presence of substances, such as those occurring in serum, which interfere with adsorption. Membranes of cellulose triacetate and of certain other materials have a very low affinity for these viruses. Cellulose triacetate filters adsorb virtually none when the pore size exceeds the virus diameter by a factor of more than 3. At porosities nearer the virus diameter, even low-affinity membranes adsorb large quantities of virus unless serum or some other additive interferes. Cellulose nitrate membranes, in the absence of interfering substances, adsorb enterovirus significantly at a pore size 285 times the virus diameter.
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  • 106
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An interesting cholinergic compound has been isolated from the fungus Rhizoctonia leguminicola grown on extracts of red clover hay. The compound was characterized as 1-acetoxy-8-aminooctahydroindolizidine and given the name “slaframine.” It has been shown that slaframine is not the active compound but is converted to the active metabolite by liver microsomal enzymes. Physiological studies with slaframine point out that it is a potent stimulator of exocrine glands. In addition, its long duration of action and low toxicity suggest that it may have therapeutic value. Preliminary data suggest that slaframine is a potent stimulator of pancreatic activity, and its long duration of action results in a stimulation of protein synthesis by the gland.
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  • 107
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    Biotechnology and Bioengineering 10 (1968), S. 698-706 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A rocker mammalian cell culture system is described. The basic mechanical component is a special incubator with contained rocker culture trays. The system provides for precise environmental temperature regulation with intermittent rocking of contained cultures in such a manner as to permit thin fluid overlay of cells with maximum accessibility to oxygen while circumventing the problems of evaporation, substrate depiction, etc.
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  • 108
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    Biotechnology and Bioengineering 10 (1968), S. 741-763 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Mathematical models have been constructed which relate the depth of the culture fluid overlay to the oxygen available to mammalian cells cultured under static conditions. These models suggest that the maintenance of a given rate of oxygen utilization by some culture systems may be critically depended on this fluid depth and on the solubility and rate of diffusion of oxygen in the culture fluid. The importance of these concepts as applied to the isolation and growth of differentiated cells representative of the tissue of origin are noted.
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  • 109
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    Biotechnology and Bioengineering 10 (1968), S. 303-320 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A novel and convenient method for the synthesis of guanosine is described. The reaction of AICA-riboside with sodium methylxanthate gave 2-mercaptoinosine in almost quantitative yield. The latter was oxidized with hydrogen peroxide to afford inosine-2-sulfonic acids, which was readily animated to give guanosine in excellent yield. Similarly, the preparation of N2-methylguanosine and N2,N2-dimethylguanosine, minor constituents of transfer RNA, was also accomplished. Furthermore, this procedure was extended to the synthesis of 2′,3′-O-isopropylideneguanosine and the isopropylidene derivatives of various N2-substituted guanosines from 2′,3′-O-isopropylidene-AICA-riboside. Guanosine via 2′,3′-O-isopropylideneguanosine was successfully phosphorylated to give 5′-guanylic acid.
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  • 110
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A HeLa cell line was propagated in semicontinuous suspension culture, 85 liters final volume, and in continuous flow culture with a volume of 300 ml. or 5 liters in an autoclavable medium to which 8% calf serum had been added. A medium containing 0.1% Methocel and 2% calf serum was also tested. Maximum productivity was obtained at a dilution rate of 0.33 day-1 with a cell density of about 1.0 × 106 cells/ml. The same cell line was also infected with Rubella virus and the production of virus was followed at the 5-liter cultivation level.
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  • 111
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    Biotechnology and Bioengineering 10 (1968), S. 385-397 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The purpose of this experimental study was to examine the transient response of a chemostat-type continuous culture of Escherichia coli B to step changes in temperature by following transient limiting substrate concentration and calculating from it the transient growth rate. The transient response to step changes of temperature was tested for four different situations. In the first two cases, temperature was shifted down from 37 to 27°C., and 37 to 32°C. In the last two, it was shifted up from 32 to 37°C., and 27 to 37°C. When the temperature was shifted up, the growth rate increased rather rapidly to its transient maximum value and then decreased slowly until it, settled back into the steady-state value. On the other hand, when the temperature was shifted down, the growth rate decreased relatively rapidly to its transient minimum and then it slowly increased and returned gradually to the steady-state value. The magnitude of the transients was less than would be expected if the transient growth rates followed an Arrhenius function.
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  • 112
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Colisan has the formula Lys3Val4Leu3IleTyr and a molecular weight of approximately 1500. Neither N-terminal nor C-terminal group have been found. The peptide is highly resistant to hydrolysis by proteolytic enzymes (pepsin and trypsin). The ∊-amino groups of lysine are indispensable for biological activity, since either deamination or acetylation completely inactivates Colisan. A comparative study with basic peptides like polylysine demonstrated their similarity of action, on one hand, and an antagonistic effect to Colisan, on the other. The fast action of the antibiotic and the specific effect on the cell membranes of many different biological systems (Entameba, Paramecium, erythrocytes, smooth muscle, and others) support the hypothesis that the primary damage occurs in the membrane with consequent alteration of permeability. The leakage of intracellular material (histamine) from mast cells after application of Colisan is in accord with this hypothesis. The results strongly suggest that the biological activity of the peptide is based essentially, but not exclusively, on its basic character.
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  • 113
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    Biotechnology and Bioengineering 10 (1968), S. 535-549 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An automatically working test arrangement for the permanent analysis of O2 and CO2 in microbiological cultures is described. The measuring principle is based on the paramagnetic properties of oxygen and on the absorption of infrared by carbon dioxide. The preparation of the gas for measuring and the correction of the recording are indicated. The formula of correction was programmed and the values were calculated for a range of 3%. The routine correction of analysis values is done with a nomogram established on the basis of these individual values. The advantages of the described test arrangement are illustrated by two examples of growth experiments on Saccharomyces cerevisiae.
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  • 114
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    Biotechnology and Bioengineering 10 (1968), S. 551-552 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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  • 115
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    Biotechnology and Bioengineering 10 (1968), S. 497-510 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An analysis is presented of the effects on substrate utilization and cell growth of varying the volume distribution of and the input distribution to a model continuous-culture unit consisting of three stirred tanks. The model is used to establish the best volume and input distributions and to indicate the effects of mixing imperfections. The Michaelis-Menten rate expression is utilized, including an endogenous respiration term, and results are presented on unique triaxial charts. Of the distributions considered, maximum substrate utilization is achieved with 60% of the total volume in the first stage, 20% in the second stage, and 20% in the third stage and with all of the input to the first stage. At a constant fractional input to the third stage; variation in the ratio of inputs to the first and second stages has virtually no effect, except in the case that a critical dilution is exceeded. At a constant input ratio to the first two stages, an increase in the fractional input to the third stage always decreases efficiency. Three stages, regardless of relative size, are always better than one. Except for endogenous respiration effects, cell growth parallels substrate utilization.
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  • 116
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    Biotechnology and Bioengineering 10 (1968), S. 483-496 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The effect of NaCl on the yield of biological solids and on the ability of continuously cultured heterogeneous microbial populations to remove substrate was assessed by changing the salt concentration in the inflowing synthetic waste. During the period of increasing the salt concentration to 30,000 mg/l the system could not maintain a high substrate removal efficiency. However, after an acclimation period the system regained its former efficiency. Upon diluting the salt out of the system, a significant rise in cell yield was noted as the salt level passed through the range 8,000-10,000 mg/l. It was found that steady operation at a salt level of 8,000 mg/l sustained the cell yield at a high level.
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  • 117
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    Biotechnology and Bioengineering 10 (1968), S. 567-587 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Virus quantitation is discussed stressing the discrepancy between the biological titer and the physical virus particle count. When both these techniques are used in conjunction, one can more realistically catalog viral properties. The merits of this technique are exemplified in a study of the growth kinetics and properties of vesicular stomatitis virus in tissue culture.
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  • 118
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    Biotechnology and Bioengineering 10 (1968), S. 617-624 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A new concept of tissue culture equipment and procedures was developed for the mass-scale growth of several types of animal tissue cells in monolayers on multiple glass surfaces. Continuous, cell lines, primary and diploid cell strains were grown in this equipment. Cells studied include primary bovine kidney, human diploid WI-38, human foreskin, and mouse CCL1 cells. Photomicrographic comparisons of cells grown by these techniques indicate they are morphologically identical to tissue culture cells grown in glass bottles or tubes. The growth of the tissue culture cells in the propagator was monitored by carbohydrate Utilization and acid production. Large-scale production of viruses and biochemicals on cells grown in the multiple-plate tissue culture propagator was accomplished. Virus titers were equal to those obtained from conventional bottle or tube cultures for several strains of influenza, parainfluenza, and respiratory syneytial viruses. High-titred mouse interferon was also produced in this system. In addition to tissue culture cell production, Eaton agent, Mycoplasma pneumoniae was grown on the multiple glass surfaces on a mass scale.
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  • 119
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    Biotechnology and Bioengineering 10 (1968), S. 681-683 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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  • 120
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    Biotechnology and Bioengineering 10 (1968), S. 689-692 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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  • 121
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    Biotechnology and Bioengineering 10 (1968), S. 707-723 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A mathematical model is presented for both batch and continuous cultures of microorganisms utilizing inhibitory substrates. The key feature of the model is the use of a inhibition function to relate substrate concentration and specific growth rate. Simulation studies show that the primary result of inhibition by substrate in a batch culture is an increase in the lag time whereas in continuous culture inhibition by substrate may result in process instability. The model should be of value in investigations of the stability of biological processes used for the treatment of certain industrial wastes such as those containing phenols, thiocyanates, nitrates, ammonia, volatile acids, etc., which are known to be inhibitory to many of the organisms metabolizing them.
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  • 122
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    Biotechnology and Bioengineering 10 (1968), S. 33-43 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The growth of batch-cultivated yeast Candida lipolytica on three kinds of gas oil using mineral medium was studied. A linear dependence was found between the production of yeast biomass and the consumption of n-alkanes, while the decrease of freezing point of gas oil during cultivation had a distinct course. This disproportion was explained by different degradation of individual n-alkanes contained in gas oil. The rate of degradation of pentadecane, hexadecane, and heptadecane was the same during the entire cultivation. On the contrary, in the first phase the utilization of shorter chain n-alkanes, nonane to tetradecane, was more rapid while that of longer chain homologs, octadecane to pentacosane, lagged. Rapid utilization of longer chain n-alkanes did not occur before the concentration of the other n-alkanes decreased. Only then the rapid decrease of freezing point appeared.
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  • 123
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    Biotechnology and Bioengineering 10 (1968), S. 45-59 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The influence of agitation and aeration on growth and on production of glucose oxidase of Asp. niger has been studied. It was found that both rate of growth and glucose oxidase production was higher at an agitation speed of 700 rpm than at 460 rpm. Further increase in speed of agitation resulted in neither a higher rate of growth nor a higher glucose oxidase activity. Total glucose oxidase activity was highest in a medium containing 5% sugar (at an agitation speed of 700 rpm) and did not get higher when the sugar concentration of the medium was increased to 7%. When pure oxygen was bubbled through the culture the rate of growth of the culture (in the linear phase) was 95 mg. mycelial dry wt./100 ml./hr., and only 61 mg. when air was applied. The glucose oxidase activity of oxygenated culture was double the activity of aerated culture. Viscosity of the homogenized culture became higher with higher concentration of mycelia. The viscosity of oxygenated culture was found to be lower than that of aerated culture.
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  • 124
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    Biotechnology and Bioengineering 10 (1968), S. 99-101 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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  • 125
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    Biotechnology and Bioengineering 10 (1968), S. 105-131 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: As a rate equation of microbial cell growth, the Monod equation is widely used. However, this equation cannot fully correspond to real courses of microbial cell growth in many batch cultivations. Especially, predicted values based on this equation do not agree with observed values in many continuous cultivations. In this paper, which introduces new concepts of critical concentration and coefficient of consumption activity, the growth rate equation which corresponds to the whole period including lag period is newly derived and characteristics of microbial cell growth in batch cultivation are clarified. Further, applying the new rate equation to continuous cultivation, a general equation with which to calculate cell concentration is derived and characteristics of microbial cell growth in continuous cultivation are clarified. The calculated values of cell concentration based on the new theory showed quite good agreement with the observed values in both batch and continuous cultivation.
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  • 126
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    Biotechnology and Bioengineering 10 (1968), S. 177-188 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This is the first part of a systematic study on the mechanisms of the Waldhof fermentor. When an agitator is rotating in a liquid, a vortex will develop on the surface. Air is dispersed into the liquid when the vortex is deep enough to reach the agitator. This is the basic mechanism of air dispersion in a Waldhof fermentor. In this work, experimental results, empirical correlations, and theoretical equations were obtained to relate the vortex depth to a number of physical factors including agitator diameter, agitator speed, tank diameter, liquid depth, liquid viscosity, and so on. The vortex depth was found a function of both Reynolds number and Froude Number.
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  • 127
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    Biotechnology and Bioengineering 10 (1968), S. 243-246 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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  • 128
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    Biotechnology and Bioengineering 10 (1968), S. 255-255 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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  • 129
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    Biotechnology and Bioengineering 10 (1968), S. 291-302 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A major problem involved in the direct fermentation of nucleotides is their breakdown by phosphohydrolases. Thus, adenine auxotrophs of most microorganisms produce hypoxanthine and/or inosine rather than inosine 5′-monophosphate (IMP) while guanine auxotrophs excrete xanthosine rather than xanthosine 5′-monophosphate (XMP). Examination of a Bacillus subtilis mutant producing hypoxanthine plus inosine revealed at least four phosphohydrolases, three of which could attack nucleotides. Even when the extracellular nucleotide phosphohydrolase was inhibited by Cu+2 and its surface-bound alkaline phosphohydrolase was repressed and inhibited by inorganic phosphate, or removed by mutation, the breakdown products were still the only products of fermentation. Under these conditions, the third enzyme, a surface-bound non-repressible nucleotide phosphohydrolase was still active. It appears, at least in B. subtilis, that excretion is dependent upon breakdown by this enzyme and if hydrolysis does not occur, excretion of purine nucleotides is feedback inhibited by the resultant high intracellular IMP concentration. Corynebacterium glutamicum mutants, on the other hand, can excrete intact nucleotides, and direct fermentations for IMP, XMP, and GMP have been described. An examination of phosphohydrolases in a GMP-producing culture revealed no extracellular or surface enzymes. Disruption of the cells resulted in liberation of cellular phosphohydrolase activity with a substrate specificity remarkably similar to the flavorenhancing properties of the 5′-nucleotides. The order of decreasing susceptibility was GMP, IMP, XMP; AMP was not attacked.
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  • 130
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    Biotechnology and Bioengineering 10 (1968), S. 359-372 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Polyribonucleotide: orthophosphate nucleotidyl transferase, commonly known as polynucleotide phosphorylase catalyzes the reversible polymerization of ribonucleoside diphosphates with the liberation of orthophosphate. The equilibrium constant is approximately 1.0. Although isolated from a variety of sources, the enzyme occurs essentially as two types: one which does not require a primer for reaction initiation and a second which does. A parallel study of an E. coli preparation representing the first type and an M. lysodeikticus preparation representing the second showed differences other than the primer requirement. Rates of polymerization were different as were the Kms. The E. coli preparation catalyzed the synthesis of polyguanylic acid while the M. lysodeikticus preparation did not although synthesis of hetoropolymers containing guanylic acid was catalyzed by the M. lysodeikticus enzyme. Use of repurified commercial substrates made the validity of some primer-requirement experiments suspect. End group analysis of product polymers served only to raise questions concerning the reaction-initiating compounds and the reaction mechanism. A study of hetero-polymer synthesis showed not only that the rate of polymerization was different, from that of homopolymers but that uncompetitive inhibition rather than competitive inhibition occurred when two ribonucleoside diphosphates were present in the reaction mixture. Furthermore, the experiments showed a preferential uptake of one substrate over another and an “enrichment” which was constant. It has also been shown that RNA polymerase, a DNA-RNA directed polymerase, can be used to synthesize polyribonucleotides if the appropriate template is provided.
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  • 131
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    Biotechnology and Bioengineering 10 (1968), S. 413-427 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Substances which cause emesis in pigeons were extracted from corn (Zea mays) artificially inoculated with Fusarium graminearum and from liquid culture medium inoculated with F. moniliforme, F. roseum, F. poae, F. culmorum, and F. nivale. Emetic preparations were obtained also from infected wheat (Triticum aestivum L. em. Thell), (Hordeum vulgare L. em. Lam), and durum (Triticum durum Desf). Partial purification resulted from chromatography with columns of cellulose and DEAE cellulose and with thin layers of silica gel. Two active materials were obtained from liquid culture of F. moniliforme but only one from infected cereals. Emetic preparations from F. moniliforme and infected cereals contained a polypeptide as a minor component. Ultraviolet and infrared spectrums, elemental analyses, refractive indices, and amino acid composition of the emetic from corn and one of the emeties from liquid culture of F. moniliforme were similar but not identical. Attempts to crystalline these emetics and to characterize them were unsuccessful.
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  • 132
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    Biotechnology and Bioengineering 10 (1968), S. 469-482 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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  • 133
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    Biotechnology and Bioengineering 10 (1968), S. 553-553 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
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  • 134
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    Biotechnology and Bioengineering 10 (1968), S. 557-566 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A procedure to maintain genetic control of virus production in tissue cell lines, has been proposed and discussed. Both the tissue cell which replicates the virus and the virus inoculum must be homogeneous in order to produce a product with the expected characteristics. Certain philosophical and technical aspects of the problem are discussed in relation to developing and maintaining genetically homogeneous stock cultures, inoculum, and product.
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  • 135
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    Biotechnology and Bioengineering 10 (1968), S. 625-640 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Studies of the possible viral etiology of human leukemia have required large quantities of cultured cells derived from human hematopoietic tissues. Since cultures sufficiently large and free from contamination could not readily be produced according to existing methods, a pilot, cell culture plant has been constructed for the production of mammalian cells in mass quantity. 500-ml to 20-liter trophocell units have already proved to be scientifically and economically practical, as they provide good reliability, excellent growth rates, and sustained yield of human cells. 200-liter stainless steel culture units have now been added to the trophocell system. Five complete 200 liter units are now in operation. The design of the original stainless steel unit was based on that of a stainless steel, jacketed soup kettle. There are no openings in the vessel other than those in the lid, which provide convenient access points for sampling, sensor probes, etc. Environmental parameters, e.g., liquid level, temperature, and pH, are monitored and controlled with commercially available apparatus. Many initial problems connected with the new 200 liter units have been resolved, but operational and design problems remain in the areas of stable instrumentation, cell harvesting, salvaging and reuse of unspent media components, establishment of physiologic steady stale, recovery of virus-containing cells with reculture of the remaining unaffected cells, and the recovery and separation of cell components and special products such as immunoglobulins, interferons, and hormones. A definitive cell plant with culture units of 20, 50, 250, and 1250 liters is now being constructed.
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  • 136
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    Biotechnology and Bioengineering 10 (1968), S. 669-675 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: New trends and developments in vaccines emphasized the growing need for safety tests of increased complexity, rather than a need for ultrasophisticated and complex devices. The Vaccine Development Branch of the National Institute of Allergy and Infectious Diseases, operating with an annual budget of $6,000,000 has the task of expediting the collaborative efforts of 50 laboratories for developing, producing, and testing experimental vaccine lots. Rubella has a major priority; other priorities are assigned to respiratory syncytial, parainfluenza, adenoviruses, influenza, and rhinoviruses, and Mycoplasma pneumoniae. To accomplish this requires a very expensive and complex program involving rapid information exchange and increased emphasis on safety testing with regard to extraneous viruses and the oncogenic potential of the vaccines. The latter need resulted from such experience as that with the Salk vaccine and the tumorproducing potential of some adenoviruses. Electron microscopy has been useful in discovering possible viral contaminants. Of all material produced for experimental work, from 65 to 70% is used for safety tests.
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  • 137
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    Biotechnology and Bioengineering 10 (1968), S. 693-697 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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  • 138
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    Biotechnology and Bioengineering 10 (1968), S. 725-740 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: It has been demonstrated experimentally that the thickness of fluid overlay in conventional tissue culture systems limits the oxygen available to mammalian cells growing as a submerged monolayer. A rocker culture system is described which circumvents critical problems associated with thin film culture while permitting nearly unlimited access of oxygen to the cell monolayer. Good growth of primary hepatic cells as isolated sheets has been obtained.
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  • 139
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    Biotechnology and Bioengineering 10 (1968), S. 801-814 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A 3-liter culture vessel has been developed for the growth of animal cells in suspension at controlled pH and dissolved oxygen partial pressure (pO2). The culture technique allows metabolically produced CO2 to be measured; provision can be made to control the dissolved CO2 partial pressure. In cultures containing a low serum concentration, gas sparging to control pO2 was found to cause cell damage. This could be prevented by increasing the serum concentration to 10%, or by adding 0.02% of the surface-active polymer Pluronic F68. The growth of mouse LS cells in batch culture without pO2 control was found to be limited by the availability of oxygen. Maximum viable cell populations were obtained when dissolved pO2 was controlled at values within the range 40-100 mm Hg.
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  • 140
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    Biotechnology and Bioengineering 10 (1968), S. 511-533 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A Candida sp. was grown on a fraction of n-alkanes (dodecane 22%, tridecane 48%, tetradecane 28%) as sole carbon source. The growth rate was increased most markedly by using high concentrations of n-alkanes (16.7% v/v). When grown in a 5 liter fermentor, the yeast reached its highest yield (60 g. of cell dry wt/l) with a concomitant high yield of fatty acids (21 g of fatty acids/l), by using a nitrogen-deficient medium. To achieve good growth, it was essential to use an inoculum (1 part into 10) of rapidly growing cells and beneficial to increase the agitation rate gradually once growth had begun. After 108 hr maximum conversions of substrate to product were: 71.5% (w/w) for alkanes into cells and 24.8% (w/w) for alkanes into fatty acids. Of the, total fatty acids at the end of the fat-accumulating phase of growth 54% were shorter in chain length than palmitic acid (C16H32O2). When grown on glucose, as sole carbon source, less than 2% of the total fatty acids were shorter than palmitic acid. When n-alkanes were added to cells growing on glucose, short-chain fatty acids (C10 to C14) were synthesized immediately, indicating a derepressed enzyme system for hydrocarbon assimilation and the absence of diauxie. The production of these acids was at the apparent sacrifice of linoleic acid synthesis. In spite of the high conversion ratios, it is concluded that it would be uneconomical to produce fatty acids, even expensive ones such as lauric acid, by microbial transformation of n-alkanes.
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  • 141
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    Biotechnology and Bioengineering 10 (1968), S. 555-555 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
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  • 142
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    Biotechnology and Bioengineering 10 (1968), S. 601-615 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Various multisurface mass-scale tissue culture propagators ranging in capacity up to 200 liters have been developed at Abbott Laboratories. These patented units consist, of an enclosed vessel containing a multiplicity of separated glass plates or disks on which cells may attach and proliferate. Means for mixing and aeration of the medium are provided. Sample ports facilitate the addition of cultures and media, the withdrawal of samples, the washing of cell monolayers, and the harvesting of cells and cell products. The large cell growth surface per occupied volume, the provision for separating tissue cells from media simply and easily, and the minimization of the amount of labor required per cell growth area are some of the many advantages of the multisurface tissue propagator that are described.
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  • 143
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    Biotechnology and Bioengineering 10 (1968), S. 651-668 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The herpes-type virus found in certain cell cultures derived from Burkitt's lymphoma, other human leukemias, and normal human leukocytes, was concentrated and partially purified by large-volume density gradient centrifugation using zonal centrifuge systems. Using the Jiyoye (P-3) cell line as a model, rate-zonal runs on disrupted cell suspensions in sucrose gradients yielded concentrates with high virus particle counts when 10-15 ml of packed cells were processed per liter of gradient. Isolation and removal of cell nuclei or fluorocarbon treatment of cell sonicates permitted virus recovery from larger volumes of cells per experiment. Zonal centrifugation of concentrated cell-free spent media from highly infected cell cultures yielded more purified virus than obtained from cells. Viral concentrates were prepared with particle counts of 1010-1011/ml and total protein concentrations of 0.2-0.5 mg/ml. Subsequent isopyenie-zonal centrifugation of the various high-count virus fractions from the zonal centrifuge showed a heterogeneity in buoyant virus density ranging from 1.18 to 1.27 in potassium tart rate. The spread in virus density was attributed to the different morphological forms of the virus observed by electron microscopy.
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  • 144
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    Biotechnology and Bioengineering 10 (1968), S. 677-680 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The production of large quantities of microbial mass, or their by-products, frequently requires aeration and mixing of fluid media. This operation often results in copious production of foam which cannot be exhausted with the effluent air or gas. Foam is usually controlled with antifoam agents which may interfere with product purity, oxygen uptake, and with subsequent product, handling. The process herein described obviates the requirement for antifoam agents or other foam-control methods. In essence, the air (or other gases) and foam in the headspace are continuously withdrawn, entrained in the intake side of a self-priming pump, and reintroduced into the bulk of the process liquid medium. The headspace may be enriched with oxygen or other gases.
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    Biotechnology and Bioengineering 10 (1968) 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
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  • 146
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    Biotechnology and Bioengineering 10 (1968), S. 1-31 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Although the basic parameters for ethylene oxide sterilization are established, it is sometimes difficult to attain in practice where the principal limiting factor is moisture availability. There are situations which can limit or enhance the dynamics of sterilization. Such factors, if overlooked, could upset experiments and lead to erroneous conclusions, or defeat the sterilization process entirety. Such are, namely: stratification effects, diffusion barriers, moisture-reducing effects, polymerization, and temperature distribution gradients.
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    Biotechnology and Bioengineering 10 (1968) 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
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  • 148
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    Biotechnology and Bioengineering 10 (1968), S. 589-599 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Baby-hamster kidney (BHK) cell cultures grown in rolling 2-liter Baxter bottles are used for the production of foot-and-mouth disease virus (FMDV) which is subsequently purified. The bottles are held securely in round wire racks (19 per rack) and rotated on a three-tiered roller mill. The use of a strongly buffered growth medium makes changes of the medium unnecessary. A sheet of aluminum foil is used to seal the cultures. It is pressed tightly over all the bottles in a rack by means of a polyurethane foam sheeting bonded to the underside of a rigid snap-on cover. Special equipment eliminates removing the bottles from the racks at any stage in their use. The loaded racks fit directly onto headers of a glassware washer. Spent cell growth media and virus fluids are collected by inverting an entire rack of bottles-Current production is 400 BHK cultures (21 racks) containing 8 × 108 cells each after 6 days growth. About 344 of these cultures (18 racks) are used to grow virus. The purification process yields about 113 mg of pure FMDV per week; the overall recovery based on infectivity is 32%. The projected maximum production of purified virus in the present facilities is approximately 2.5 times greater than this amount.
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  • 149
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    Notes: This study reports some findings on the effects of centrifugation on the viability of mammalian cells. The authors used Burkitt lymphoma cells cultivated in a synthetic medium containing 10% fetal calf serum for all experiments. Batch centrifugations were conducted in a RC2-B centrifuge (Ivan Sorvall, Incorporated, Norwalk, Connecticut USA) operated at 0 and 25°C. During centrifugation we exposed the cells to gravitational fields ranging from 24,800 to 42.200g. The results showed that at, 0°C and 25,800 or 42,000g no loss in cell viability occurred for up to 90 min exposures in the centrifugal field. However, at 25°C and for gravitational fields of 24,800 and 42,000g, there were appreciable losses in cell viability. Continuous centrifugation studies in the Sharples supercentrifuge (Division of Penn Salt Corporation, Warminister, Pennsylvania USA) were also conducted with bowl speeds up to 28,000 rpm (19,000g) and flow rates ranging from 1.4 to 20 1, hr. Slight, losses in cell viability were noted and postulated as caused by the shear stresses encountered by the cells. Some pumping studies using the lymphoma cells substantiate this conclusion.
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    Biotechnology and Bioengineering 10 (1968), S. 684-688 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Equipment has been developed for the recovery of precipitates from rotors of industrial tubular centrifuges. A double piston is described for nonaseptic discharge of precipitates through the outlet holes of the clarifier rotor. For the aseptic resuspension or dissolving of valuable precipitates a closed-circulation system has been developed, which is applied without opening of the clarifier rotor.
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  • 151
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    Biotechnology and Bioengineering 10 (1968), S. 765-785 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Two experimental methods were used in measuring oxygen-transfer rates. The results indicate that two possible mechanisms are operating in simultaneous gas-liquid interfacial oxygen absorption and biochemical oxidation. One of the mechanisms, the direct absorption mechanism, has not been much studied in bioengineering. Mathematical equations are derived to describe the simultaneous mechanisms.
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  • 152
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    Biotechnology and Bioengineering 10 (1968), S. 829-843 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A laboratory process for the isolation of type B acid phosphatase from human erythrocytes has been scaled up 80 times. The enzyme was purified 1300-fold by adsorption on calcium phosphate gel, ammonium sulfate precipitation, and gel filtration. The yield was 27%. Results for the type A enzyme are also presented.
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  • 153
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    Biotechnology and Bioengineering 10 (1968), S. 845-864 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The inhibitory effect of ethanol concentration p in a medium on the specific rates of growth μ and ethanol production ν of a specific strain of baker's yeast was studied in a chemostat, where except for ethanol as the product, only the concentration of glucose S was controlled to limit the metabolic activity of the yeast. This was designed to supplement the previous findings from the batch experiment, in which ethanol was added artificially and no substrate components were limiting the metabolism of the same yeast, that μ = μ0e-k1p and ν = ν0e-k2p, where k1 and k2 are empirical constants and subscript the 0 denotes respective values at p = 0. The effects of p on the values of μ and ν were confirmed by the Lineweaver-Burk plot to belong to noncompetitive inhibition. The formulas here for μ and ν as affected by p, if extrapolated to the case of no limiting substrates, were in good agreement in respective forms with those derived previously from the batch experiment, though the values of corresponding coefficients in these formulas were different. The differential equations for μ and ν as functions of both p and S and, in addition for the rate of glucose consumption as correlated by the yield factors either with the cell growth rate or the rate of ethanol production, were solved properly with a digital computer. A kinetic, pattern calculated so far was discussed with reference to the data obtained in the batch experiment and those relevant to actual “sake” brewing.
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  • 154
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    Biotechnology and Bioengineering 10 (1968), S. 61-67 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A relatively simple, autoclavable medium was developed that would support the growth of the mouse fibroblast (MFL) cell line in suspension culture. This medium was prepared in three stages with decreasing quantities of serum. As the serum was reduced from 5% to none, the amount of Bacto-Peptone was increased from none to 0.5%. The reduction and finally elimination of serum did not affect proliferation adversely, but actually seemed to produce more rapid growth and higher levels of cell population.
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    Biotechnology and Bioengineering 10 (1968), S. 257-275 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Conditions for the efficient conversion of commercial RNA to nucleoside 5′-monophosphate by means of a phosphodiesterase in malt sprouts have been determined. A comparison of the enzyme content of the rootlets, stems, and kernels of various plant seedlings, including barley, rye, oat, wheat, rice, and beans shows maximum amounts in the rootlets, and minimum quantities in the ungerminated kernels. Of all the seedlings tested, (mung bean, soy bean, oat, wheat, rice, barley) barley gave the highest conversion of RNA to 5′-nucleotides. Commercial malt sprouts prepared from 6 different malted barleys including 2-rowed and 6-rowed samples all showed about the same amount of phosphodiesterase content. Besides phosphodiesterase, other enzymes capable of hydrolyzing RNA and 5′-nucleotides were found in sprouts. These included 3′-phosphodiesterases, 5′-nucleotidases, and nucleosidases. By carefully pretreating both extracts and the solid sprouts at elevated temperatures for a limited time and by the addition of minimum amounts of Zn+2, the action of these undesirable enzymes was either effectively destroyed or minimized so that the production of 5′-nucleotides was maximized. It was found that suspensions of appropriately washed and treated barley malt rootlets are substantially more effective than aqueous extracts for converting RNA to 5′-nucleotides.
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  • 156
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    Biotechnology and Bioengineering 10 (1968), S. 321-330 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Rat liver was subjected to three different, disruption procedures (homogenization, explosive decompression, and Chaikoff press) and mitochondria were subsequently isolated by conventional differential Centrifugation and by zonal Centrifugation. The properties of these mitochondria were investigated by polarographic measurement of oxygen uptake and they were examined by electron microscopy. All three methods of disruption gave mitochondria which showed respiratory control. Nitrogen cavitation gave the most reproducible conditions for cell breakage and zonal Centrifugation gave good separation of subcellular organdies in extracts produced by this method. Some separation of the heterogenous mitochondrial populations was achieved by zonal Centrifugation.
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    Biotechnology and Bioengineering 10 (1968), S. 399-402 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Biotechnology and Bioengineering 10 (1968), S. 457-467 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Toxicological investigations were conducted on two new antibiotics, Muconomycin A and Muconomycin B. These non-nitrogenous antibiotics were found to be highly toxic and capable of inducing profound inflammation in the peritoneal cavity of male albino rats. Either antibiotic produced large volumes (10-20 ml) of inflammatory exudate even when injected intraperitoneally in quantities of 1.6 × 10-10 moles. An extensive profile of the electrolytes and proteins found in inflammatory exudates was developed. Simultaneous assays of the blood serum of treated rats provided a basis for comparing the concentrations of constituents of serum with those of the exudate. The results of these assays showed that the exudate contained lower concentrations of sodium and proteins, and greater amounts of potassium, calcium, and phosphorus than the serum. Chloride ion concentrations were variable. Since previous work showed that one of the manifestations of toxicity of these substances was the production of creatinuria, further studies were carried out with ATP/Creatine Phosphotransferase. These studies show that these antibiotics are potent in vitro inhibitors of the enzyme ATP/Creatine Phosphotransferase.
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  • 159
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    Biotechnology and Bioengineering 10 (1968), S. 102-103 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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  • 160
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The epithelium lining the intrahepatic bile ducts of normal adult mice consists of a single layer of cuboidal or low columnar cells and has ultrastructure comparable to that described previously (Rouiller and Jézéquel, '65). Some of the epithelial cells, however, exhibit such particular features as dilatation of granular endoplasmic reticulum cisternae, polysome formation of ribosomes and the presence of active forms of the Golgi apparatus, numerous lysosome-like bodies and apical projections and blebs. Postnatal cholecystectomy does not induce any qualitative changes in the epithelial fine structure, but results in a significant increase in number of the particular structures mentioned. Therefore, the cholecystectomy is thought to stimulate the secretory activity of the epithelial cells, and such stimulation appears due to the absence of a possible activity of epithelial secretion in the gallbladder.
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  • 161
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    Journal of Morphology 124 (1968) 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 162
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Blastocysts from nulliparous, multiparous, superovulated, post-partum, and lactating rabbits were recovered five to nine days post-coitum (p. c.), weighed, and dissected in order to obtain the blastocoelic fluid for analysis of glucose, lactic acid, and nitrogen. The largest daily percentage of increase in the volume of blastocoelic fluid occurred between five to six days p. c., whereas, the largest absolute increase occurred between seven and eight days p. c. The weight of the blastocyst and trophoblast, and the volume of fluid was higher in the multiparous and post-partum does than in others. At eight days p. c., the concentration of glucose in the blastocoelic fluid reached a maximum comparable to the maternal blood level; subsequently a decline occurred. Lactic acid levels were similar to those of glucose. The amount of protein increased dramatically until seven days p. c. The amount of non-protein-N to total-N reached a peak at six days p. c., then declined. The chemical composition of blastocoelic fluid was influenced by the maternal condition, i. e., glucose and lactic acid were higher in superovulated (good response), overcrowded and multiparous groups than in others. While protein was lower in the overcrowded, post-partum and superovulated groups, it was higher in others.
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  • 163
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    Journal of Morphology 124 (1968), S. 187-215 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The infracerebral gland of Nereis consists of an epithelium covering the ventral surface of the posterior region of the brain. The thickness of the epithelium varies greatly in different species, and it appears especially well developed in Nereis limnicola. Cells of the most numerous type are in direct contact with the base of the brain. Their apical surfaces bound a coelomic sinus, below which is a blood plexus. Other cells are fuchsinophilic and contain many inclusions resembling elementary neurosecretory granules. A third type is rare and resembles glial elements. A number of nerve tracts run from the neuropil to the base of the brain in the region of the gland. Where they impinge upon the capsule they form swellings containing elementary granules and small vesicles. Some axons do not end on the capsule but pass through the capsule and then ramify among the cells of the gland. The swollen endings of other fibers, probably nervous in character, are packed with mitochondria and are scattered over the inner surface of the capsule in the region of the gland. The features described are suggestive of a neuroendocrine complex, and the relation between the brain and the infracerebral gland is in need of experimental analysis in view of the important endocrine functions presently ascribed to the brain in nereids.
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  • 164
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Eggs of the common snapping turtle, Chelydra serpentina serpentina were incubated at 30°C and at 20°C. The incubation period at the higher temperature was about 63 days. At the lower temperature, the period was estimated to be 140 days. Lengths of the embryos at various times of development were recorded. A series of 26 stages is described. The staging is based on timed intervals at a constant temperature, 20°C.
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  • 165
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    Journal of Cellular Physiology 71 (1968), S. 17-22 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Cultures of several cell lines convert cytidine, if present in their medium, to uridine. The reaction is rapid, being virtually complete within one hour. The enzymatic activity is that of cytidine aminohydrolase (EC 3.5.4.5). The activity is exhibited by the intact cell  -  substrate and products being found in the medium bathing the cells. The activity should be taken into account in studies involving cytidine, and other 6-amino pyrimidine nuclecsides.Of nine transformed cell lines, and nine primary and secondary cell strains screened for the presence of cytidine aminohydrolase activity, six cultures were positive. All the positive cultures were heteroploid transformed lines. No diploid strain cultures were positive, and two near diploid mouse lymphoid neoplasms were negative. PPLO contamination was not detected in the positive cultures.Within the limited series of cell cultures screened in this study, there appears to be a correlation between heteroploidy and the ability of the intact cultures to deaminate cytidine in excess of the cell requirement for the precursor.
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  • 166
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    Journal of Cellular Physiology 71 (1968), S. 43-59 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The interferon mechanism offers the hope for moderate to high level prophylactic immunity of broad antiviral spectrum but of relatively short duration. Economic and biological considerations offer little hope for utilization of exogenous interferon as a prophylactic or therapeutic substance, unless but a small part of the total molecule be found to carry the activity. The real promise for interferon application is in the administration of suitable inducers so as to cause the body to produce and distribute its own interferon. Certain ribonucleic acids (RNA's) offer hope for high level potency as inducers without adverse effect. The condition for interferon induction by ribonucleic acids appears to be double- or multistrandedness and freedom from inhibitors. These can be of biologic or synthetic origin. The mechanism of action of interferon is not fully understood but appears to fit into the Jacob-Monod model involving two phases: first, a derepression by the inducer to cause the cell to form interferon and second, a derepression by interferon to cause recipient cells to form the active substance which acts by preventing translation from viral messenger RNA. Double or multistranded RNA of viral or other origin appears to be unique to the cell and serves as the alert to it to produce interferon in phase 1. Greatest need for interferon is clearly for those diseases in which there is a multiplicity of immunologic types in excess of the numbers which could be put into a vaccine as, e.g., the common cold and enteric viruses. There might be some overall therapeutic benefit also if inducer were given early enough in infection. Special value for interferon induction might derive by administration in early life before the development of immunologic maturity, as a means for preventing infection with oncogenic or other viruses. Additionally, suitable inducers might be capable of interrupting the reinfection cycle in virus-dependent malignancies.The favorable outlook for interferon utilization must always be tempered with the realization that under certain as yet undiscovered situations, adverse rather than beneficial effects might result from indution of interferon. It is not impossible that in certain special circumstances, as in ordinary immunologic responses, it might be more beneficial to negate rather than to promote the effect.
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  • 167
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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    Topics: Biology , Medicine
    Notes: The rate of RNA synthesis in synchronously growing HeLa S3 cells was determined as a function of position in the cell generation cycle. Measurements throughout the cycle of both the rate of incorporation of radioactively-labeled uridine and of the total amount of RNA indicate that (1) the rate of RNA synthesis is constant (or increases only slightly) during G1, approximately doubles during the first half of S, and then remains constant during the remainder of S and G2, and (2) cells attain the average G1 rate of RNA synthesis very early in G1, and maintain the average G2 rate until mitosis.If the initiation of DNA synthesis is blocked, the acceleration of RNA synthesis is markedly reduced or eliminated. Further experiments in which DNA synthesis was inhibited at different times in S, or to varying degrees from the beginning of S, suggest that the extent to which RNA synthesis is accelerated depends on the amount of DNA duplicated. These data also indicate that duplication of the first half, and in particular the first few per cent, of the DNA complement results in a disproportionate acceleration of RNA synthesis.The possibility that fluctuations in the sizes of precursor pools may lead to misinterpretation of labeled-uridine incorporation data was examined. Experiments indicate that in this system pool fluctuations do not cause invalid measures of RNA synthesis.It is concluded that RNA synthesis occurs throughout interphase, but undergoes a two-fold increase in rate which is dependent on the duplication of DNA.
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  • 168
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    Journal of Cellular Physiology 71 (1968) 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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  • 169
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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    Notes: Using the hematopoietic colony technique, we have investigated the repopulating potential of bone marrow cells and leukocytes of blood from normal mice and have demonstrated that the frequency of hematopoietic stem cells in bone marrow is 50 to 150 times that of stem cells in the circulating blood. The differentiation capacity of these stem cells has also been examined. Results of comparative studies of the serial sections of hematopoietic colonies formed from marrow and blood leukocytes indicate that the differentiation capacity of stem cells from marrow and blood is similar, and that at least 80% of these cells differentiate along a single cell line. Thus, peripheral blood stem cells can effect a complete hematopoietic graft, establishing in the host, donor red cells, granulocytes, and platelets.The possibility that blood leukocytes may serve as a potential source of stem cells for hematopoietic transplants has been considered. Although blood contains stem cells, their frequency is so low as to make it unlikely that they would become a useful source of precursor cells for transplantation purposes.
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  • 170
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    Journal of Cellular Physiology 71 (1968), S. 177-184 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Visible light of moderate intensity causes two and perhaps three types of division inhibition in Euglena gracilis are related cells. Fluorescent light causes a general inhibition of growth and division which is temperature-dependent. Pigmentation or complex organic media partially lifts this inhibition. A second type of inhibition, which is transient, can be caused by either fluorescent or incandescent light, and is found with an irreversibly bleached strain of Euglena grown on a limiting concentration of acetate; this inhibition could not be demonstrated in cells grown on limiting concentrations of glucose.
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  • 171
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    Journal of Cellular Physiology 71 (1968), S. 151-159 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The specific catalase activity of human diploid cell strains increases with progressive growth of the culture, and falls again following subculture. Although the increase is small, it is readily demonstrable, and is exponential with time.The response of catalase activity to proggressive growth of the culture was studied in three abnormal human cell lines. A diploid cell strain, developed from a patient homozygous for the gene causing acatalasia I, had no detectable catalase activity throughout the life cycle of the culture. Another diploid cell strain, developed from a patient homozygous for the gene causing acatalasia II, had about 5% normal catalase activity, but the proportionate increase in specific activity as the culture grew was the same as for normal cells. Thus the mutation causing acatalasia II does not change the responsiveness of the cell in terms of catalase activity to progressive growth of the culture. The behavior of a heteroploid line was similar to that of the normal diploid strains, but when the growth of the heteroploid cultures reached a plateau, their population densities were four times higher than those of the diploid strains and they had about twice the specific catalase activity.
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  • 172
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    Notes: Hybrid cell lines have been prepared between 3T3, a line highly sensitive to contact inhibition of division, and cl 1-D, an L cell derivative which is not sensitive. A number of hybrid clones isolated were found to be quite sensitive, indicating that in this respect the 3T3 behavior is the more fully expressed in the hybrid. On serial subculture, the hybrid lines gave rise to variants less sensitive to contact inhibition.
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  • 173
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    Notes: The cellular and subcellular events in the anamnestic response were considered. Rabbits previously immunized with key hole limpet hemocyanin (KLH) were given an anamnestic challenge in the hind footpads. The popliteal lymph nodes were removed at intervals after immunization and the following correlated on a temporal basis: the changes in the number and types of cells in the lymph nodes; the formation and regression of ribosomes, polyribosomes, endoplasmic reticulum and Golgi apparatus in plasma cells; the changes in intracellular immunofluorescence for anti-hemocyanin; and, the incorporation of 14C labeled amino acids by lymph node cells into anti-KLH during a brief in vitro culture period.Maximum intracellular fluorescence for anti-KLH and the largest incorporation of 14C labeled amino acids into antibody occurred between the third and fourth day after immunization. During this interval highly differentiated plasma cells were most numerous with respect to the total cellular population. These events took place in a 12 to 24 hour period.This was followed by an abrupt decline in the synthesis of antibody. Coincident with this was a reduction in the number of recognizable plasma cells in the nodes, diminished intracellular fluorescence for anti-KLH and a simplification of the cytoplasm of the plasma cells toward a lymphocytic form.
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  • 174
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    Notes: Photoreactivation of growth and DNA synthesis in UV-irradiated cells and photoreactivating-enzyme activity of cell-free extracts can be demonstrated in a cell line derived from liver tissue of the African clawed toad, Xenopus laevis. This cell line, A8W2, is a favorable system for the quantitative study of photoreactivation in vertebrates.
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  • 175
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    Journal of Cellular Physiology 71 (1968) 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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  • 176
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    Journal of Cellular Physiology 72 (1968) 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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  • 177
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    Notes: The proliferation and differentiation of hemopoietic cells from genetically anemic Wv/Wx,W/Wv, and Wv/Wv mice, and from nonanemic carrier W/+, Wb/+, and Wv/+ mice have been evaluated in vivo by transplantation techniques and in vitro by the agar gel culture method. Marrow from anemic and carrier mice contained progenitor cells which were decreased in number and formed small, often rudimentary, colonies in the spleens of irradiated recipient mice. Proliferation and differentiation of both erythropoietic and leukopoietic progenitor cells were delayed and reduced, but erythropoiesis was more severely affected than leukopoiesis. The severity of the hemopoietic impairment was gene-dose dependent. The W gene effect on leukopoietic progenitor cells was not secondary to anemia or to abnormal erythropoiesis.The marrow cells of anemic and carrier mice which form colonies of granulocytic and mononuclear cells in vitro were neither decreased in number nor impaired in proliferation and differentiation. Hypertransfusion of red blood cells increased the frequency of in vitro colony-forming cells, but not that of in vivo progenitor cells.The data demonstrate that colony-forming cells which proliferate in the agar gel cultures in vitro are distinct from the in vivo colony-forming cells and suggest that the former are primitive members of the granulocytic cell line. Perhaps in vitro CFU are in an intermediate stage of differentiation between in vivo CFU and myeloblasts, analogous to that which has been suggested for the erythropoietin-sensitive cell in the red cell series. W mutant alleles appear to act, therefore, at or very near the beginning of hemopoietic differentiation.
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  • 178
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    Notes: Colony formation and growth in vitro by C57B1 mouse bone marrow cells were analysed following stimulation by a standard dose of serum colony stimulating factor. Under restricted conditions, colony crowding was observed to potentiate colony growth rates. The addition of thymic or lymph node lymphoid cells or nonviable bone marrow cells also potentiated colony growth. Extensive reutilisation of nuclear material by bone marrow colony cells was observed when labeled lymphoid and bone marrow cells were added to the culture system. The results provide evidence that lymphocytes can exert trephocytic effects on proliferating hematopoietic cells.
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  • 179
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    Notes: Fibroblasts transformed by oncogenic viruses were found to have greater enzymic activities of four membrane glycoprotein:glycosyl transferases on a cell or protein basis then two non-transformed fibroblastic lines. These enzymes are responsible for the synthesis of membrane glycoproteins; each of the four transferases studied, the polypeptide:N-acetylgalactosaminyl, glycoprotein:galactosyl, fetuin:fucosyl and PSM:fucosyl transferases, was more than twice as active in the transformed cell lines using both endogenous and added receptor. The most pronounced differences occurred with the doubly (SV-PY-3T3) transformed fibroblasts in all cases; with the N-acetylgalactosaminyl and galactosyl transferases the increase was 8-16 fold over the non-transformed cells. It was demonstrated that these results do not arise from a changed level of glycosidase activities.
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  • 180
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    Journal of Cellular Physiology 72 (1968) 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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  • 181
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    Journal of Cellular Physiology 72 (1968), S. 153-159 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The effect of external divalent cation salt solutions upon the association of an action potential and cessation of cytoplasmic streaming in Nitella was studied. Nitella cells remained excitable when immersed in solutions of CaCl2, MgCl2, BaCl2, and SrCl2. Cessation of streaming coincident with excitation occurred in solutions of CaCl2 or SrCl2 but not in solutions of MgCl2 or BaCl2. In cells exposed to solutions containing mixtures of MgCl2 and CaCl2, or MgCl2 and SrCl2, it was the [Ca]/[Mg] or [Sr]/[Mg] which determined the effect of an action potential upon the rate of streaming, rather than the absolute concentrations Ca++ or Sr++. The implications of these data are discussed with respect to the structure involved in the generation of cytoplasmic streaming and the relation of streaming to other types of biological motion.
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  • 182
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    Journal of Cellular Physiology 72 (1968), S. 173-183 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The pyrimidine requirements for growth of T. pyriformis and for reversal of the growth inhibition caused by folate deprivation have been studied. The effects of thymidine and 5-fluorodeoxyuridine have been shown to be quantitatively different from the effects of these compounds on growth and the rate of DNA synthesis in mammalian cells. Labelled nucleosides added to the medium have been found to be converted to the corresponding bases with the exception of deoxycytidine, which is first deaminated to deoxyuridine. As a result no deoxynucleosides other than thymidine specifically label DNA.The results allow deductions to be made concerning the enzymes involved in pyrimidine utilization by this organism. It is suggested that pyrimidine utilization is always channeled through uracil in the case of those compounds that can supply the pyrimidine requirement for growth.
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  • 183
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    Journal of Cellular Physiology 72 (1968), S. 221-228 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The probability of a colony which originated as a single stem cell to become extinct due to differentiation of all of its stem cells in any generation is closely connected to stem cell self renewal probability p. p can be determined from the coefficient of variation of the colony numbers received by reinjecting single colonies of the same age. Whole spleens containing a known average colony number can also be used with advantage for this purpose. The results of both procedures indicate a stem cell self renewal probability p =0.62 ± 0.04, which does not change significantly between the sixth and the fourteenth day of colony development, and an extinction probability ω = 0.63 ± 0.12.
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  • 184
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    Journal of Cellular Physiology 72 (1968), S. 247-249 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Notes: Rat bone marrow cells were seeded as mass cultures or for cloning together with inducer required for colony formation, and at various times after seeding, the cells were re-seeded for cloning either with or without inducer. The results indicate that the development of both macrophage (M) and granulocyte (G) colonies requires a continued supply of the inducer. No M or G colonies were produced when the inducer was replaced by erythropoietin.
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  • 185
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    Journal of Cellular Physiology 72 (1968), S. vii 
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  • 186
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    Journal of Cellular Physiology 72 (1968), S. 19-34 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Cytodifferentiation of skeletal muscle has been studied in cell cultures derived from leg muscle of 12-day chicken embryos. Myogenesis in cell culture closely simulates myogenesis in vivo, but is more highly synchronized. Massive cell fusion occurs in control cultures between the second and third days in vitro, during which time most of the myoblasts are swept into syncytia. On successive days, the syncytia mature into cross-striated muscle fibers, and the cultures are progressively overgrown by fibroblastic cells. Myosin-containing cells can be detected at any time by immunofluorescence, and myosin has been measured by quantitative immunological precipitation as early as 3 days in vitro, a few hours after fusion. Myosin in the cultures increases over the next few days, and this is reflected in the rate of incorporation of labeled amino acids into immunologically precipitable myosin. Creatine kinase, assayed spectrophotometrically by linked dehydrogenase reactions, shows a similar pattern: measurable early but rapidly increasing in activity after fusion. That this increase in myosin and creatine kinase is strictly a function of the multinuclear cells is demonstrated by experiments in which the mononuclear cell population has been drastically reduced by treatment with 5-fluorodeoxyuridine shortly after fusion. Myosin synthesis has not been detectable in cells prevented from fusing by growth in 5-bromo-deoxyuridine, but low levels of creatine kinase have been demonstrated. Newly formed muscle fibers incorporate precursors into RNA at lower rates than do mononuclear cells. The relationship of this change in RNA synthesis to the formation of muscle proteins remains obscure.
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  • 187
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    Notes: The process of vitellogenesis in oviparous vertebrates embraces a number of integrated physiological and developmental phenomena. Since this process is readily subjected to experimental control in Xenopus laevis, we have been able to undertake a preliminary survey of the pertinent mechanisms operating in this animal.The information at hand is discussed as it relates to (a) the hormonal (estrogen) induction of yolk protein synthesis by the liver, (b) the characterization of the yolk protein produced and its relationship to the proteins of the mature egg, (c) the transport of the yolk protein to the ovary and its specific uptake by the developing oocyte, and (d) the transformation of the accumulated protein into crystalline yolk platelets.
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  • 188
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    Journal of Cellular Physiology 72 (1968), S. 129-144 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Because its differentiation can be channeled into different pathways, amphibian gastrula ectoderm is a convenient test system for studying factors that control embryonic differentiation. 1Chemical nature of inducing factors: A substance that induces muscle and notochord in ectoderm has been isolated from chick embryos and other sources. The factor is protein in nature (mol. wt. in 6 m urea 25,000--30,000). Neural tissue is induced by a crude ribonucleoprotein fraction. Purified RNA has only a very weak inducing activity. The inducing factors are preferentially located in cytoplasmic particles.2Mechanism of action: Embryonic induction has to be considered as a derepression. Preliminary experiments have shown that a high-molecular-weight, water-soluble substance takes part in the inhibition of mesodermal differentiation. The inhibition of differentiation is released by the inducing factors. A close relationship between differentiation and RNA synthesis has been revealed by experiments with actinomycin D (0.5--2.5 μg/ml), which inhibits RNA synthesis. If RNA synthesis is completely stopped in the gastrula stage, the mesodermal area, which is already determined to differentiate into muscle and notochord, still forms some notochordal cells and myoblasts. The differentiation of neural tissue, however, is completely inhibited. DNA-RNA hybridization experiments at the saturation level suggest that new messenger RNA species are synthesized if differentiation proceeds. But this does not exclude that the inducing factors exert control primarily at the level of translation.
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  • 189
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    Journal of Cellular Physiology 72 (1968), S. 213-219 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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  • 190
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    Journal of Cellular Physiology 71 (1968), S. 109-120 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A sulfated glycosaminoglycan has been isolated from the acid-soluble fraction of an established line of Chinese hamster fibroblasts grown in suspension culture. This material has a molecular weight between 5000 and 10,000, contains equimolar amounts of hexosamine and uronic acid (orcinol method), and about 0.6 sulfate groups per hexosamine residue. About 80% of the sulfate groups are N-sulfates on the basis of lability of the sulfate and the formation of equivalent numbers of free amino groups upon mild acid hydrolysis. The material is completely resistant to testicular hyaluronidase but is degraded to reducing monosaccharides and small oligosaccharides upon treatment with lyophilized cells of Flavobacterium heparinum that were grown on heparin. It is thought, therefore, to be related to the known N-sulfated glycosaminoglycans heparin and heparitin sulfate.
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  • 191
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    Journal of Cellular Physiology 71 (1968), S. 161-163 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Human diploid cell strains develop progressively higher levels of specific catalase activity as they grow. Following subculture activity falls again. A diploid cell strain heterozygous for the gene for acatalasia I (acatalasemia) was found to develop specific catalase activity at proportionately the same rate as normal cell strains. Yet the mutant gene reduced the absolute level of specific catalase activity which the culture attained at any given point in time. In this respect the heterozygous acatalasia I strain resembles the homozygous acatalasia II strain previously reported.
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  • 192
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: It was shown previously that the specific catalase activity of human diploid cell strains falls immediately after subculture and then progressively rises in an exponential fashion. In this paper evidence is presented suggesting that the rise in catalase activity cannot be due to an accumulation within the cell of a small molecule which enhances enzyme activity in cell-free extracts. It is also shown that activity per cell, as well as per unit cell protein, rises as the culture grows.The rate of fall of specific catalase activity immediately after subculture is greater if the cells are at a low population density than if they are at a high one. The rate of fall can be made more sharp by increasing the frequency with which the cultures are fed.It is shown that used medium, which has previously been incubated with cultured cells of the same strain, does not significantly change either the rate of fall of specific catalase activity following subculture, or the rate of its subsequent rise. It is postulated, as one possibility, that the cells liberate into the medium an enhancer of cell catalase activity which is highly labile. The steady state concentration of this enhancer in the medium might be expected to increase as the culture grew, but to decrease when the cells are subcultured into fresh medium or when the frequency of feedings is increased.
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  • 193
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Erythropoietic activity of spleen cell grafts was measured (Fe59 uptake) in X-irradiated recipient mice under conditions in which these grafts were engaged in homograft reactions against allogeneic target cells or in graft-versus-host reactions. Such Fe59 incorporation was greatly reduced at 7 to 10 days after graft implantation relative to that of control grafts. This reduced erythropoiesis did not occur when the spleen cell graft was immunologically incompetent. Transplantation of bone marrow-lymph node cell mixtures also resulted in a relative decline in Fe59 uptake, but only when minimal numbers (105 to 106) of marrow cells were injected. The incorporation of I125 UdR in the spleen of irradiated recipients was used to assess cellular proliferation. Incorporation of this label was reduced when measured 7-10 days after implantation of the lympho-hemopoietic cell graft, but reached a peak at five days - the latter indicating stimulated lymphopoiesis. These data are consistent with the concept of depletion of a pluripotent stem cell pool (limited in size under these experimental conditions) due to excessive and concurrent functional demands for erythropoiesis and lymphopoiesis. An alternative explanation would involve cytotoxic effects on hemopoietic elements present in the milieu of the immunologic reaction.
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  • 194
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The periodic mating behavior of some stocks of Paramecium aurelia, syngen 3, exhibits features typical of circadian rhythms. In the most extensively studied stock (37p), rhythmicity persists at least four days in continuous darkness, but disappears rapidly in continuous illumination (200 foot-candles). The period of the free-running rhythm is 22.2 hours, and relatively insensitive to ambient temperature. Cycles of illumination and temperature can regulate the mating rhythm. Changes in illumination at specified times in the circadian cycle will induce shifts in the phase of the rhythm. Stock differences with respect to the persistence of the rhythm and the environmental control of its phase have been observed.
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  • 195
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    Journal of Cellular Physiology 72 (1968), S. vii 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 196
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    Journal of Cellular Physiology 72 (1968), S. 1-8 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Differential equations have been written and solved to describe the concentration gradients for the two hydra growth factors. The equations consider diffusion, catabolism and synthesis of the materials based primarily on the model of hydra growth described by A. L. Burnett. Concentration gradient profiles were obtained which correspond with the concentration gradients deduced from experimental evidence. It has also been possible to show that in areas of high mitotic rate, mitotic rate is related to the calculated concentration ratio of the two growth factors (stimulator/inhibitor). However, the correspondence of mitotic rate to growth factor concentration ratio does not hold for extreme values of the ratio indicating that very high and very low concentration ratios are not conductive to mitotic activity.
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  • 197
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Exogenous ATP can induce a marked cell enlargement in TA3 tumor cells which can be reversed or prevented by Ca and Mg. This regulatory effect on cell volume is specific for ATP. The mechanism probably involves changes in cell ionic content.
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  • 198
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Foreign plasma injection induces a profound and somewhat complex change in the size and location of the colony forming unit (CFU) cell compartment. Injection of foreign plasma before irradiation induces an increase in CFU cells as judged by endogenous colonies as well as by a modification of the endogenous method which excludes spleen colony formation from in situ spleen cells. However, the enlargement does not take place in the most populous CFU cell areas, the spleen and marrow. The concentration and/or total number of CFU cells in spleen and marrow was not increased by plasma injection whether judged by the number of transplantable cells or by the number of migrating endogenous cells.These studies emphasize the complexity of this cellular system and suggest that the use of but one type of stem cell assay may yield results which do not reflect changes within the total compartment. Evidence for cell damage in vitro as a factor influencing results in studies involving transplantation was searched for but was not forthcoming.
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  • 199
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    Journal of Cellular Physiology 72 (1968), S. 39-42 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The cytological effects of 2 mM hydroxyurea upon Chinese hamster cells at various phases of the cell cycle were examined. Cells in the G1, G2, or M phases of the generation cycle treated with hydroxyurea showed no chromosomal aberrations. Cell treated in S phase became moribund and eventually lysed. Some of these moribund S cells reached mitosis much later and were found to have chromatid aberrations. Cells in the log phase of growth, surviving exposure to 2 mM hydroxyurea for six hours, also showed no aberrations. Thus, viable (colony-forming) cells, resulting from synchrony procedures with hydroxyurea are free of chromosomal aberrations.
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  • 200
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    Journal of Cellular Physiology 72 (1968), S. 97-107 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: An investigation of the physiological effects of phenethyl alcohol (PEA) on exponentially growing yeast cells is reported. RNA, DNA, protein and aminoimidazole ribotide syntheses and glucose uptake and incorporation are inhibited by PEA at concentrations of 0.1% to 0.3%. Two classes of response curves are found and the sensitivities of processes in each class to PEA differ. Glucose incorporation and RNA synthesis are the most sensitive processes in their respective classes. The effects of PEA at 0.3% or less are largely or completely reversible. It is deduced that PEA inhibits intracellular processes as well as the cell membrane.
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