摘要:

Twenty-nine human adult and eight monkey tissues were studied in culture. The addition of prednisolone to growth media restricted the growth to epithelial-like cells and also provided a slight growth stimulus. Thirty-four specimens of acute hepatitis origin failed to provide indications of virus. Detroit-6 cells were cultured in synthetic media supplemented with sheep serum. Sixteen experiments were inoculated with 82 specimens of acute hepatitis origin. There were no conclusive results with this line of cells.

ISSN:0008-4166    

DOI:10.1139/m59-068

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

The trypanosomid flagellate,Crithidia fasciculata, has been shown to have, in the absence of exogenous substrate, a long-sustained oxygen consumption (R.Q. 0.85) accompanied by the production of ammonia. Ribose, xylose, fructose, glucose, galactose, mannose, maltose, cellobiose, sucrose, raffinose, glycerol, and dihydroxyacetone abolish this oxygen consumption while increasing the rate of respiration up to fivefold. Glucose is incompletely oxidized (R.Q. 1.06) with the consumption of 2.6 moles of oxygen and production of 0.6 moles succinate and 0.4 moles ethanol and traces of pyruvate per mole of glucose consumed. Ethanol and a variety of other alcohols can be metabolized when presented as the only exogenous substrate. These results are discussed with respect to the metabolic activities of other members of the family Trypanosomatidae and to the hypothesis that the end products accumulate as a result of limiting amounts, rather than complete absence, of certain enzymes.

ISSN:0008-4166    

DOI:10.1139/m59-069

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

As part of a study of the microflora developing on plant roots, analyses were made of the fungal populations of non-sterilized barley, flax, and wheat seed and of their primary roots 2 days after seeding in natural soil and at short intervals thereafter over a period of 3 weeks. It was found that fungi associated with the seed played little part in the colonization of roots in the soil. Species ofAspergillus,Penicillium, andAlternaria, abundant on the seed, were rarely obtained from root samples. The young roots (2 days after seeding) were relatively free from fungi; however, those which were colonized at this time yielded species ofPythiumandFusariumpredominantly. In subsequent samples the percentage incidence ofPythiumdeclined markedly, the predominating types being species ofFusarium,Phoma,Pullularia,Periconia, andCylindrocarpon, the latter genus assuming greater prominence on wheat than on either barley or flax.

ISSN:0008-4166    

DOI:10.1139/m59-070

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

Respiration-deficient mutants can be induced in populations ofSaccharomycesgrowing in the presence of the cysteine antagonist, allyl glycine. Mutations occur, however, only among cells which had been cultivated anaerobically so as to be unadapted to aerobic respiration prior to exposure to the antagonist. The mutagenicity of allyl glycine is relieved by cysteine, and to a lesser extent by homocysteine, methionine, or alpha-amino-n-butyric acid. It is accentuated by homoserine. Evidence is presented indicating that the ability of allyl glycine to induce respiratory mutants is distinct from its general growth-inhibiting properties. It is concluded that the maintenance of the genetic determinant of respiration inSaccharomycesdepends upon a particular metabolic function in which cysteine participates. In cells cultivated anaerobically that function is so limited that it can be rendered effectively inactive by growth in the presence of allyl glycine.

ISSN:0008-4166    

DOI:10.1139/m59-071

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

Studies were carried out to determine the effect of the products of acid hydrolysis of agar on the growth ofEscherichia coli. The inhibitory effect was associated with the degree of hydrolysis of the agar. This inhibition has been obtained at two very different levels of concentration. When the hydrolysis was complete, the inhibitory pattern was similar to that of 5-hydroxymethyl-2-furaldehyde. Under conditions of mild acid hydrolysis, the inhibitory effect was caused by a heat-labile degradation product of 3,6-anhydro-L-galactose.

ISSN:0008-4166    

DOI:10.1139/m59-072

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

A detailed study of the influence of the age factor upon the susceptibility of the white mouse to experimental infection with a standard strain of Coxsackie B-3 virus has been undertaken. A fairly accurate assessment of the susceptibility of the brain, heart, and brown fat tissues has been achieved by examining sufficiently large groups of animals inoculated at ages varying from 4 days to 182 days by histological and virological procedures.The contrasting patterns of changing susceptibility in the brain and heart were quite remarkable. Brain lesions were not found in mice inoculated after 12 days of age but heart lesions were severest in animals inoculated between 12 and 23 days of age. In both heart and brown fat tissue lesions could be found in adult animals infected with Coxsackie B-3 virus. Attention is drawn to the fact that the pathological response in the brown fat tissue is different in sucklings, weanlings, and adult mice.

ISSN:0008-4166    

DOI:10.1139/m59-073

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

Myocarditis has been produced in both young and adult mice by the inoculation of Coxsackie B-3 virus. Newborn mice were not as susceptible to myocardial damage as 12-day-old mice and the susceptibility increased up to the age of 23 days; thereafter there was a decline but 6-month-old animals were moderately susceptible.Both the strain of animal used and the age at which it was inoculated appeared to be significant factors. Other factors such as route of inoculation, sex, virus concentration, or nature of the inoculating material did not greatly affect the outcome. The lesions produced were very similar to those described in human myocarditis of the newborn.The importance of these findings lies in the fact that myocarditis due to Coxsackie virus can be produced regularly in both young and adult mice without the aid of cortisone or other extrinsic factors.

ISSN:0008-4166    

DOI:10.1139/m59-074

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

The total amount of nitrogen fixed and the efficiency of nitrogen fixation, by strainClostridium pasieurianumW5 have been increased by using improved cultural conditions. Also, consistent growth of the organism in shake culture has been obtained. Evidence is presented supporting the view that hydrogen is a specific, competitive inhibitor of nitrogen fixation in this organism. TheKmfor nitrogen fixation is around 0.03 atmosphere and the estimatedKifor hydrogen inhibition is 0.5 ± 0.05 atmosphere, a value considerably higher than that found in the other nitrogen-fixing systems studied.

ISSN:0008-4166    

DOI:10.1139/m59-075

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

A number of molds, streptomycetes, and bacteria, obtained from culture collections and by enrichment techniques, were tested for their ability to degrade rutin. The molds, particularlyAspergillus fiavusandA.niger, appeared to be more active than either the streptomycetes or bacteria. The aspergilli when grown on either rutin or quercetin produced extracellular enzymes that degraded both rutin and quercetin but not quercitrin. Rutinose, protocatechuic acid, phloroglucinol carboxylic acid, and a phloroglucmo! carboxylic acid – protocatechuic acid ester were identified by paper chromatography as the products.

ISSN:0008-4166    

DOI:10.1139/m59-076

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

The proteolytic specificity of a purified proteinase, Nagarse, ofBacillus subtilisN′ towards denatured lysozyme was compared with that of the organism growing in a model soil system consisting of a heat-denatured lysozyme–kaolinite complex in a paste form which represents the natural habitat of soil organisms. The use of a sterile technique and a specially designed apparatus permitted periodic withdrawal of nonadsorbed and nonassimilated proteolysis products from the medium; such products were formed by the proteolytic activity of exoenzymes excreted byB.subtilisN′. A chromatographic comparison was made between the proteolysis products ofB.subtilisN′ growing in the lysozyme–kaolinite system and those of the proteinase Nagarse acting on denatured lysozyme in solution; some differences were observed. The growth rate studies indicated that the lag period of growth ofB.subtilisN′ in the lysozyme–kaolinite complex extended up to one day. The bacteria excreted exoenzymes during this lag period, which hydrolyzed the substrate protein, but the proteolysis products were not assimilated until the exponential growth period started.

ISSN:0008-4166    

DOI:10.1139/m59-077

出版商:NRC Research Press    

年代:1959

数据来源: NRC