ÉTUDE D'UNE LIGNÉE DE CELLULES KB INFECTÉES CHRONIQUEMENT PAR LE VIRUS PARA-INFLUENZAE TYPE 3 : I. ASPECTS DE LA PRODUCTION VIRALE

1962 ◽  
Vol 8 (5) ◽  
pp. 709-718 ◽  
Author(s):  
Philippe Daniel ◽  
Charles Chany
Keyword(s):  
Culture Medium ◽  
Virus Production ◽  
Plaque Formation ◽  
The Other ◽  
Cell Resistance ◽  
Carrier System ◽  
Type 3

A strain of cells chronically infected with type 3 para-influenzae virus was obtained. The proportion of virus-producing ceils in this carrier system, called KB.EA, was measured by two different technics. Only a fraction of KB.EA cells, varying from one experiment to the other, was found to produce the virus. Virus production did not seem to take place simultaneously in all the cells, which apparently yielded the virus at varying times, and occasionally only after 10 days of incubation.The titer of total virus yielded by cultures of KB.EA cells incubated at 37 °C and 41 °C was determined at fixed intervals over a period of 4 days.The titer showed marked variations during the course of both types of cultures. The amount of total virus harvested at 41 °C was about a tenth of that obtained from the culture incubated at 37 °C. No "hot-mutant" could be detected after 4 days of incubation at 41 °C.The addition of a potent antiserum in the culture medium did not sterilize the KB.EA strain although the same serum inhibited the plaque formation induced by type 3 para-influenzae virus on normal KB cells.From the results obtained, several hypotheses meant to explain the cell resistance and the persistence of virus in cultures of KB.EA cells are discussed.

scholarly journals The equations applicable to simple hœmolytic reactions

1926 ◽  
Vol 100 (702) ◽  
pp. 199-222 ◽  
Keyword(s):  
Elementary Theory ◽  
The Other ◽  
Considerable Degree ◽  
Fundamental Importance ◽  
Cell Resistance ◽  
Frequency Curve ◽  
Secondary Reactions ◽  
Sigmoid Curve

The purpose of this paper is to develop and to consider in detail some of the expressions which may be applied to reactions involving simple hæmolytic systems. In doing so, a number of rather unusual conditions have to be considered; these may first be set down. 1. It has been shown (1) that the curves obtained by plotting the amount of hæmolysis, expressed as a percentage of the total, against time, are sigmoid in form, the sigmoid curve often presenting a considerable degree of skewness in one or the other direction. In explanation of this form, it was suggested that the cells of the system present different degrees of resistance to the action of the lysin, these resistances being distributed according to a symmetrical frequency curve, and that the skewness encountered is due to the presence of secondary reactions, principally the reaction of the liberated cell-contents with the lysin. Such suggestions are, in general, in agreement with the findings of Brooks (2), of Fulmer and Buchanan (3), and of other workers on hæmolysis and the allied problem of bacteriolysis. To the two papers mentioned the reader is referred for excellent discussions of both facts and elementary theory, as well as for reviews of the literature. It appears that the bulk of the recent investigation has shown that these variations in cell resistance, and the distribution of these resistances, are of fundamental importance in problems of this kind, and that it is completely fallacious to deal with such problems without allowing for the heterogeneity of the material involved.

Comparing the Arrangements of Governance and Sustainable Development in OECD Countries: Coupled or Decoupled?

2019 ◽  
Vol 34 (1) ◽  
pp. 99-117
Author(s):  
Huh Taewook
Keyword(s):  
Sustainable Development ◽  
Oecd Countries ◽  
The Other ◽  
Type Analysis ◽  
Ideal Types ◽  
Type 3 ◽  
Relationship Of ◽  
The Relationship

This study attempts to analyze to what extent governance and sustainable development (SD) empirically appear compatible in the thirtyfive OECD countries through the fuzzy-set ideal type analysis, and identify which ideal types appear coupled or decoupled, and then reveal which countries belong to the coupled types or to the decoupled types. In short, twenty-two countries (including Sweden (fuzzy score, 0.953), Denmark (0.920), Finland (0.914), Norway (0.911) in Type 1 (G*S, ‘strong G-S coupled countries’); and Turkey (0.906), Greece (0.833), Mexico (0.828) in Type 4 (g*s, ‘lite g-s coupled countries’) are in line with the accepted conventions regarding the compatible relationship between governance and SD. On the other hand, the rest of thirteen countries (including USA (fuzzy score, 0.815), Luxembourg (0.721), Australia (0.660) in Type 2 (G*s, ‘G-s decoupled countries’); and Slovenia (0.728), France (0.644), Czech Rep. (0.625) in Type 3 (g*S, ‘g-S decoupled countries’) may indicate that the relationship of governance and SD is in fact experiencing tensions in the national contexts. These findings are characterized by the substance (of SD) and procedure (of governance) divide. Considering the results, this study focuses on the idea of reflexivity or reflexive capacity.

scholarly journals Evaluation of Cytotoxicity of Dentin Desensitizing Products

2015 ◽  
Vol 40 (5) ◽  
pp. 503-514 ◽  
Author(s):  
GB Eyüboğlu ◽  
C Yeşilyurt ◽  
M Ertürk
Keyword(s):  
Culture Medium ◽  
The Other ◽  
Dentin Hypersensitivity ◽  
Gingival Fibroblast ◽  
Fibroblast Cells ◽  
Cell Culture Medium ◽  
Cytotoxic Effects ◽  
Diphenyltetrazolium Bromide ◽  
Different Thickness ◽  
Very High

SUMMARY Objectives To evaluate the cytotoxic effects of the dentin desensitizing products (DDPs) used in the treatment of dentin hypersensitivity on cultured human gingival and pulpal fibroblast cells. Methods and Materials The cytotoxic effects of DDPs (Smart Protect, Systemp Desensitizer, Seal & Protect, Aqua-Prep F, Isodan, Gluma, BisBlock, D/Sense Crystal, UltraEZ, Colgate Sensitive Pro-Relief, Topex, and Clinpro White Varnish) on cultured human gingival- and pulp-derived fibroblast cells were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test (Serva, Heidelberg, Germany) under two different conditions. In the first test, different dilutions of the DDPs were directly applied onto cultured gingival fibroblast cells, and in the second test, the products were applied onto different-thickness dentin discs (0.5 and 1 mm) placed above cell culture medium, which contained pulp fibroblast cells. Results According to the cytotoxicity evaluations of gingival fibroblast cells, the cytotoxicity of all of the DDPs was very high at 50% concentrations (p<0.05). Colgate Sensitive Pro-Relief, Clinpro White Varnish, and Topex showed higher cytotoxicity than did the other products (p<0.05), decreasing with further dilutions, and these products were found to be less cytotoxic to both types of cells (p<0.05) than were the other products with further dilutions. The cytotoxicity to human gingival and pulpal fibroblast cells of Systemp Desensitizer, Aqua-Prep F, Isodan, and Gluma did not show any decrease with further dilutions, and these products were found to be more cytotoxic than the other products (p<0.05). Conclusions According to the findings of this study, Colgate Sensitive Pro-Relief, Topex, and Clinpro White Varnish were less cytotoxic than the other DDPs used in this study.

scholarly journals Secretion of β-N-acetylglucosaminidase isoenzymes by normal human fibroblasts

1978 ◽  
Vol 173 (2) ◽  
pp. 433-439 ◽  
Author(s):  
P Willcox
Keyword(s):  
Lysosomal Enzyme ◽  
Human Fibroblast ◽  
Lysosomal Enzymes ◽  
Culture Medium ◽  
Human Fibroblasts ◽  
The Other ◽  
Normal Human Fibroblast ◽  
Acid Hydrolases ◽  
Human Fibroblast Cultures ◽  
Normal Human

1. Secretion of the lysosomal enzyme beta-N-acetylglucosaminidase (EC 3.2.1.30) by normal human fibroblast cultures was linear with respect to time up to 96h. 2. Two forms of the A isoenzyme of beta-N-acetylglucosaminidase were found in the culture medium. One form was similar to the isoenzyme found in other extracellular fluids, such as plasma and tears, the other resembled the intracellular (lysosomal) enzyme. The presence of the two isoenzymes in the culture medium appears to reflect two distinct secretory processes. 3. It is suggested that plasma acid hydrolases may be destined for incorporation into lysosomes in a manner analogous to that described for the packaging of lysosomal enzymes by fibroblasts.

Production and control of extracellular enzymes in Micrococcus sodonensis

1974 ◽  
Vol 20 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Cecily Mills ◽  
J. N. Campbell
Keyword(s):  
Alkaline Phosphatase ◽  
Inorganic Phosphate ◽  
Culture Medium ◽  
Extracellular Enzymes ◽  
Synthetic Medium ◽  
Culture Conditions ◽  
The Other ◽  
Organic Nutrients ◽  
And Control ◽  
Logarithmic Growth

Micrococcus sodonensis has been shown to produce several extracellular enzymes: an alkaline phosphatase, at least two forms of phosphodiesterase, a 5′-nucleotidase, and an alkaline proteinase. The quantitative release of these enzymes into the culture medium during logarithmic growth under all the various culture conditions tested indicates that these enzymes are truly extracellular in nature. Inorganic phosphate repressed the production of the alkaline phosphatase in synthetic as well as in complex media, whereas, the repression of the production of active diesterase and 5′-nucleotidase by inorganic phosphate was partly reversed by the addition of supplemental organic nutrients to the culture medium. Proteinase production was independent of the culture conditions used. A mutant strain of M. sodonensis with an altered production of diesterase was obtained; the other extracellular enzymes were unaffected. These results suggest that the extracellular enzymes of M. sodonensis are not produced in a pleiotropic fashion since the level of one of the enzymes can be changed without affecting a corresponding change in the levels of the other enzymes. An extracellular high molecular weight carbohydrate fraction was shown to be produced by M. sodonensis in synthetic medium. The fraction was also shown to contain glycoprotein.

Exogenous dTMP utilization by a novel tup mutant of Saccharomyces cerevisiae

1982 ◽  
Vol 152 (1) ◽  
pp. 111-119
Author(s):  
L F Bisson ◽  
J Thorner
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Culture Medium ◽  
De Novo ◽  
The Other ◽  
Normal Cells ◽  
Pyrimidine Bases

The rate and extent of entry of dTMP were measured in strains of Saccharomyces cerevisiae carrying two new tup mutations (tup5 and tup7) and most of the other tup mutations which have been reported previously by others. The tup7 mutation allowed dramatically greater accumulation of dTMP than any of the other mutations tested. Specific labeling of DNA by [CH3-3H]dTMP, fate of the dTMP pool inside of the cells, and degradation of the dTMP in the culture medium were investigated in strains carrying the tup7 mutation. The extracellular dTMP was not appreciably degraded, and that accumulated intracellularly was readily phosphorylated to dTDP and dTTP. Under optimum labeling conditions, 60 to 80% of the total thymidylate residues in newly synthesized DNA were derived from the exogenously provided dTMP, even in the absence of a block in de novo dTMP biosynthesis. An apparent Km for entry of 2 mM dTMP was found. The tup7 mutation increased permeability to dTMP (and some other 5'-mononucleotides), but did not affect uptake of nucleosides and purine and pyrimidine bases. Uptake of dTMP could be almost completely inhibited by moderate concentrations of Pi. These findings and other observations suggest that entry of dTMP in strains carrying the tup7 mutation is mediated by a permease whose function in normal cells is the transport of Pi.

scholarly journals Collagen binding by vaginal aggregative lactobacilli

2015 ◽  
Vol 46 (No. 4) ◽  
pp. 89-94
Author(s):  
I. Štyriak ◽  
V. Demečková ◽  
B. Žatkovič ◽  
V. Kmeť
Keyword(s):  
Hyaluronic Acid ◽  
Lactobacillus Acidophilus ◽  
Culture Medium ◽  
Heparan Sulphate ◽  
The Other ◽  
Collagen Binding ◽  
Vaginal Lactobacillus ◽  
Gene Coding ◽  
Vaginal Swabs

Ten autoaggregating vaginal Lactobacillus strains (five of these strains were selected among isolates from sows‘ vaginal swabs and the other five among isolates from cows‘ vaginal swabs) were investigated for their ability to bind type Icollagen (Cn-I). All 10 autoaggregating strains in the range of A<sub>570nm</sub> readings 0.118–1.806 bound to immobilised Cn-I (at concentration of 100 μg/ml) in wells of microtitre plates, however, Lactobacillus acidophilus SV31 was much more adherent than the rest of the tested strains. The influence of culture medium on Cn-I binding was confirmed only in 50% of the tested strains when agar-grown cells bound significantly more Cn-I than broth-grown cells. The specificity of the binding was confirmed since the Cn-I binding by lactobacilli was abolished after their preincubation with this protein. The effect of heparan sulphate and hyaluronic acid was tested on 5 vaginal strains displaying the best Cn-I binding in microtitre plates after their cultivationon MRS agar plates. Both selected inhibitors significantly (P &lt; 0.001 or P &lt; 0.01) reduced Cn-I binding by the majority of strains. The presence of the gene coding APF (aggregation-promoting factor) was detected in seven strains (all five sows‘ and two cows‘ Lactobacillus strains) by PCR.

Mischkolonien auxotropher und Wildtypzellen nach Behandlung von Esdierichia coli-Zellen mit salpetriger Säure

1963 ◽  
Vol 18 (3) ◽  
pp. 245-252 ◽  
Author(s):  
F. Kaudewitz ◽  
K. Moebus ◽  
H. Kneser
Keyword(s):  
Experimental Evidence ◽  
Nitrous Acid ◽  
Single Cells ◽  
The Other ◽  
Mathematical Treatment ◽  
E Coli ◽  
Type 3 ◽  
Good Agreement ◽  
Hybrid Dna ◽  
In Cells

Cells of E. coli incubated in nitrous acid give rise 1. to unchanged wildtype colonies, 2. to colonies composed of wildtype and auxotrophic cells and 3. to colonies consisting of auxotrophic cells only. The mixed colonies are considered to originate from single cells each of them harbouring hybrid DNA with one subunit, probably a sisterstrand, changed by deamination of a cytosine or adenine, the other one with unchanged wildtype composition. In cells producing type 3 colonies this wildtype strand is mutated lethally by a separate deamination of a cytosine or adenine. A mathematical treatment of this hypothesis leads to predictions which are in good agreement with experimental evidence. The data obtained are used for an estimation of the number of gene-loci of E. coli.

Métabolisme de l'acide indolyl-3-acétique dans les cultures de cellules d'Acer pseudoplatanus cultivés in vitro

1977 ◽  
Vol 55 (19) ◽  
pp. 2530-2534 ◽  
Author(s):  
F. Maillard ◽  
J.-P. Zrÿd
Keyword(s):  
Cell Wall ◽  
Acetic Acid ◽  
Culture Medium ◽  
Degradation Products ◽  
Cell Suspensions ◽  
The Other ◽  
Acer Pseudoplatanus ◽  
Kinetics Of

Incubation of cell suspensions of sycamore (Acer pseudoplatanus) with β-indoyl-3-acetic acid (IAA) first led to the formation of IAA-glycosides, then to that of IAA-aspartate. Great differences are observed between the kinetics of IAA transformed by two distinct strains: one, auxin dependent (S), the other, auxin independent (MB). Other degradation products are only found in the culture medium. The localization of IAA-degrading systems in the cell wall is postulated. The auxin requirement of the S strain is discussed.

Determination of susceptibility/resistance to antifungal drugs ofTrichophyton mentagrophytesisolates by a macrodilution method

2005 ◽  
Vol 51 (11) ◽  
pp. 983-987 ◽  
Author(s):  
Maria Elisabete da Silva Barros ◽  
Júnia Soares Hamdan
Keyword(s):  
Human Population ◽  
Culture Medium ◽  
Susceptibility Testing ◽  
Trichophyton Mentagrophytes ◽  
Antifungal Drugs ◽  
The Other ◽  
Minimal Inhibitory Concentrations ◽  
Adult Human

Onychomycosis is a common adult human mycosis, and dermatophytes of the Trichophyton genera are the most frequently isolated microorganism. Globally, from 3% to 10% of the human population is attacked by ony cho mycosis, and many cases involve toenails. The aim of this work was to determine the minimal inhibitory concentrations (MICs) of antifungal drugs (fluconazole, ketoconazole, itraconazole, terbinafine, and griseofulvin) often used for the treatment of ungueal dermatophytosis caused by Trichophyton mentagrophytes. The MICs were determined by the broth medium macrodilution method. The results showed that activities of terbinafine and itraconazole were significantly higher (MIC <0.007–0.015 µg·mL–1and MIC = 0.062–1.000 µg·mL–1, respectively). All isolates had reduced susceptibility to fluconazole (MIC = 16 to >64 µg·mL–1). The MICs of ketoconazole and griseofulvin varied among strains, ranging from 0.125 to 2.000 µg·mL–1for ketoconazole and from 0.25 to 2.00 µg·mL–1for griseofulvin. These MICs were higher than those of other studies cited, possibly because of differences in culture medium used in the other studies.Key words: dermatophytes, susceptibility testing, macrodilution, onychomycosis, antifungal drugs.

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