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Biomedical subjects

E Eylan

Publications and source records attributed to E Eylan.

At least 37 records · Page 2Linked to original sources
PubMed1979

Resistance transfer factor in E. coli strains isolated from human and water sources.

Conjugation experiments with a recipient E. coli strain F-lac-NaR were performed in order to determine the extent to which transferable drug resistance is prevalent among Gram-negative bacteria isolated from the following sources: healthy infants both treated and untreated with antibiotic drugs; healthy adults previously exposed to antibiotics; water sources; and nosocomial infections. Transferable drug resistance was demonstrated in 56.6% of E. coli isolates from the antibiotic-treated infant group, in 53.2% of isolates from untreated infants, and in 43% of isolates from the adult group. R factor was carried by only 8.3% of the strains isolated from water sources, and by 26.7% of the nosocomial strains. A positive correlation between transferable antibiotic drug resistance and resistance to mercury ions was found in donor and conjugate strains. Acridine and several of its derivatives were found to be active in preventing transfer of R factor.

Acridines↗
PubMed1978

Biological characteristics of a stimulatory factor for viral replication detected in egg fluids.

Yolk sac and allantoic fluids and albumen from uninfected chicken eggs contain a low-molecular weight factor which, after 90 minutes of contact with cell cultures, significantly enhances viral replication. Of several viruses tested, Semliki Forest virus exhibited the highest (10(5)-fold) responsiveness to this enhancing factor. Maximal enhancement was obtained with cells subjected to low multiplicities of infection. The stimulation of viral replication was linear with the age of the cells in culture. The enhancing factor did not operate through an anti-interferon mechanism. However, it exerted a boosting effect on the low-grade cellular metabolism of ageing cell monolayers. Some of the physico-chemical features of the enhancing factor were determined and conjectures concerning its chemical makeup are discussed.

Allantois↗
PubMed1978

Chicken egg yolk stabilizes the reverse transcriptase activity in type C particles produced by cultured MOPC-315 murine myeloma cells.

Type C particles released from cultured murine myeloma MOPC-315 cells were significantly protected when the purification steps were all conducted in the presence of 10% chicken egg yolk fluid. The yolk fluid also slowed down the inactivation of viral particles during incubation at 37 degrees C and enabled full recovery of viral particles through several cycles of freezing and thawing. The purification of viral particles in the presence of yolk fluid did not affect the capability of the viral DNA polymerase to reverse-transcribe the virion RNA in vitro, nor that of the viral RNA to act as a functional template.

Animals↗
PubMed1978

Establishment and characterization of a cell line derived from human colon adenocarcinoma (HuCCL-14).

A continuous human colon carcinoma cell line (HuCCL-14) was established whose cells possess an epithelial-like morphology and are capable of growing in soft agar and on monolayers of normal cells. HuCCL-14 cells yielded high levels of carcinoembryonic antigen, and the analysis of their chromosomal constitution revealed a mode of 70 chromosomes per cell. HuCCL-14 cells produce malignant tumors when injected into nude mice. Preliminary virologic studies indicate the release of RNA particles having a density of 1.15--1.19 g/ml.

Adenocarcinoma↗
PubMed1978

Immunological relations of proteins from four salmonellae sharing an "O" factor 8.

The proteins from S. virginia, with the sole 8 "O" factor, precipitated against homologous and related heterologous sera by a conspicuous, homogenous line of serological identity, with proteins from: S. newport (6.8), S. blockley (6.8), S. emek (8.20). The proteins, however, were not involved in the bacterial agglutinations since the absorptions, which removed the common precipitins from the sera, did not modify the homologous agglutinations. The results with anti-S. newport and anti-S. blockley sera sharing identical "O" factors while displaying different immunochemical compositions as well as the strong immunochemical relations found between S. virginia and S. newport belonging to the different subgroups C2 and C3 underline the non-relatedness of agglutinins and precipitins.

Agglutination Tests↗
PubMed1978

Stimulated production of interferon by a low-molecular-weight factor from chicken-egg fluids.

Exposure of five-year-old L-929 cell monolayers to low-molecular-weight factor obtaiend from chicken egg-yolk fluids stimulated the production of Semliki Forest virus (SFV)-induced interferon, particularly when the cells were infected with a low-input multiplicity of SFV. The stimulatory effect on interferon production was not expressed in polyriboinosinic acid:polycytidylic acid-induced interferon. Furthermore, the high yield of interferon was correlated with and followed the increase in viral yield, thus suggesting that the yolk factor stimulates the growth of SFV, which in turn triggers the higher production of interferon. The outstanding feature of the yolk factor is its ability to stimulate the production of virus-induced interferon during the lytic cycle of virus replication.

Animals↗
PubMed1978

Induction of oncornavirus-like particles from a spontaneously transformed hamster cell line.

A spontaneously transformed hamster cell line, designated Clone B (Cl B), has been activated by halogenated pyrimidines to produce oncornavirus-like particles. The optimal conditions for virus induction were studied by the analysis of culture fluids for particles with polymerase activity. Maximal enzymatic activity was induced when exponentially growing Cl B cells were treated with 20 to 30 microgram/ml 5-iodo-2'-deoxyrudine for a 24-h period. Under these conditions, the kinetics of particle release reached a maximal level between 48 and 72 h following removal of the drug, and then decreased rapidly. The induced particles exhibited features characteristic of oncogenic RNA viruses: actinomycin D was found to inhibit their induction; the particles band in sucrose gradients at a density of 1.15 g/ml; nonionic detergent treatment releases the virion core component exhibiting a buoyant density of 1.21 g/ml in sucrose gradients; the viral particles contain high molecular weight RNA species with sedimentation coefficients of 65 S and 35 S; and the polymerase associated with Cl B particles efficiently transcribes synthetic templates preferred by the reverse transcriptases of known RNA tumor viruses, but demonstrates a very low endogenous activity.

Animals↗
PubMed1978

Immunochemistry of S. kentucky (8.20); its relations with S. emek (8.20), S. virginia (8) and S. newport (6.8).

Immunochemical studies of S. kentucky showed that the strain has an identical polysaccharide with S. emek with which it shares the same "O" factors 8.20, and a common proteinic carrier of the polysaccharide. Absorptions of anti-S. kentucky sera with proteins from S. virginia ("O" factor 8) did not influence the homologous precipitations or agglutinations, nor the cross-reactions with S. emek. In contrast, the absorptions of the anti-S. Kentucky sera with proteins from S. newport (6.8) caused a conspicuous modification in the precipitations of S. emek proteins against the absorbed serum; this coincided with a drastic fall in the agglutinating titer for the heterologous S. emek strain while the homologous agglutination was unchanged. The results underlined the role of the specific proteins as agglutinogens and, in addition, sustain Kauffmann's recommendation for the preparation of the, empirically established, monofactor serum 20.

Agglutination↗
PubMed1978

Behaviour of S. paratyphi A in mice immunized with homologous and heterologous bacterial proteins.

Mice immunized with proteins from S. typhimurium and from S. paratyphi C resisted the toxicity of a concentration of S. paratyphi A which killed the controls; this is in contrast to the results found in mice immunized with the same amount of proteins from the homologous S. paratyphi A. For the neutralization of the S. paratyphi A toxicity a higher quantity of homologous proteins was necessary in the immunizations. It is assumed that either S. paratyphi A synthesizes--on artificial media--a small amount of proteins responsible for the induction of neutralizing antibodies or that it is an intrinsic weak immunogen. In the sera of mice in which sufficient neutralizing antibodies were induced, the proteins of S. paratyphi A cross-reacted in agar-gel, with the proteins from S. typhimurium and from S. paratyphi C.

Animals↗
PubMed1977

Tumor-specific transplantation antigens in spontaneously transformed hamster cell lines.

Spontaneously transformed hamster cells were examined for the presence of TSTA by employing the tumor rejection test. It was demonstrated that each of the spontaneously transformed cell lines as well as cells derived from tumors induced by these cells possess an individual distinct antigen, capable of evoking a significant anti-tumor immunity. The immunizing potential of these antigens and their specificity were not affected by either in vivo or in vitro environment. The results suggest that the spontaneously transformed hamster cells undergo antigenic modification, which resembles the TSTA of chemical-carcinogen induced tumors.

Animals↗
PubMed1977

Inhibition of herpes simplex virus strains isolated from herpetic keratitis by polyinosinic acid-polycytidylic acid.

Fifty strains of herpes simplex virus, isolated from patients with herpetic keratitis, were examined in vitro for susceptibility to polyinosinic acid-polycytidylic acid [poly(I:C)] in the presence of a constant concentration of diethylaminoethyl-dextran. The minimal inhibitory concentration of poly(I:C) for 44 of these strains ranged from 0.0001 to 0.1 mug/ml; for the remaining six strains, the minimal inhibitory concentration stood at 1 to 2 mug/ml. Fifteen isolates from primary infections were more susceptible to poly(I:C) than 35 isolates from recurrent infections. Isolates acquired at different points of a given clinical episode showed similar susceptibilities to poly(I:C). In two patients, isolates from consecutive recurrences of infection exhibited reduced susceptibilities. The implications of the above observations for the therapeutic use of poly(I:C) are discussed.

DEAE-Dextran↗
PubMed1977

Lysozyme tear level in patients with herpes simplex virus eye infection.

The lysozyme level in tears of patients with HSV eye infection was examined and correlated with the clinical findings and presence of virus. The concentration of the enzyme in tears of patients during acute attack was 2.83 mg./ml. This value was significantly lower than that in tears from healthy controls (6.1 mg./ml.) and tears from the patient's healthy eye (4.46 mg./ml.). After termination of treatment with either IUDR or poly I:C, the lysozyme level rose to an average of 4.34 mg./ml. During the latent period of the disease the level increased (5.34 mg./ml.), but it remained lower than in healthy subjects who had never suffered from HSV eye infection. This may be an indicator of possible future recurrences.

Acute Disease↗
PubMed1977

Production of precipitating antibodies in chickens infected with Salmonella gallinarum.

Vaccination of 10 days old chicken with a live relatively avirulent S. gallinarum induced antibodies against the main antigens of the pathogen, namely, its proteins. Precipitations in agar gel were obtained against the free proteins and the protein conjugated in the somatic antigen of S. gallinarum and against antigens from the related S. enteritidis. Antipolysaccharide antibodies were induced in small quantities which were however sufficient to allow their identification with the agar-gel-diffusion technique.

Animals↗