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Biomedical subjects

L Edebo

Publications and source records attributed to L Edebo.

At least 73 records · Page 4Linked to original sources
PubMed1973

Characterization of mutants of Salmonella typhimurium by counter-current distribution in an aqueous two-polymer phase system.

An aqueous, two-polymer phase system was employed in an attempt to separate and characterize a series of R mutants, derived from Salmonella typhimurium 395 MS, with differing lengths of lipopolysaccharide chains on their surfaces. R mutants with varying degrees of virulence and phagocytic resistance were unresolved in this system. However, the smooth MS bacteria were clearly separated from the rough cells and showed a high affinity for the polyethylene glycol-rich top phase. A uridine 5'-diphosphate-gal-4-epimeraseless mutant, phenotypically in R or S form depending on the growth medium, partitioned as the R mutants and S bacteria, respectively. These results demonstrate the great influence of long polysaccharide chains on the physicochemical properties of the cell surface.

Bacteriological Techniques↗
PubMed1970

Conditions affecting the viability of spheroplasts in urine.

Penicillin-induced spheroplasts from Escherichia coli and Proteus vulgaris, which at neutral pH had little resistance to osmotic lysis, retained viability in media of low osmolality at pH 5.0 to 5.5. In the presence of 1,000 IU of penicillin per ml (pH 5.0) in liquid media, E. coli remained in rod form without conspicuous growth. On hypotonic agar media at pH 5.2 with 1,000 IU of penicillin per ml, the bacteria grew out as L-type colonies. These findings are discussed in relation to penicillin therapy.

Journal Article↗
PubMed1969

Production of photons in the bactericidal effect of transient electric arcs in aqueous systems.

The radiation in the visible and ultraviolet regions from submerged, transient electrical arcs was measured with a K(3)Fe(C(2)O(4))(3) chemical actinometer and was compared to the bactericidal effect obtained with the same electrical arrangements. Photon production and bactericidal effect were obtained at lower voltages with a smaller electrode separation than with a wider one. At higher voltages, both increased with wider electrode separations. The voltages at maximal photon production efficiency coincided with those of maximal bactericidal efficiency. However, the same photon radiation produced by different electrical arrangements did not always yield the same bactericidal effect in the small discharge vessel usually employed. In a larger discharge vessel, the bactericidal effect was closely correlated with the photon production. The efficiency of photon production by transient arcs was smaller than that of germicidal mercury lamps, particularly with respect to wavelengths of great bactericidal activity. The mechanisms of inactivation and their use for practical disinfection purposes are discussed.

Bacteria↗
PubMed1969

Virucidal effect of transient electric arcs in aqueous systems.

Bacterial and animal viruses were inactivated by high voltage electrical discharges in water. The sensitivity of phages to the immediate component of this effect was correlated to the sensitivity to ultraviolet radiation. Transient electrical arcs in weak electrolytes also generated chemical compounds which were virucidal against phages T3, T5, and varphiX174 but were only slightly virucidal against phages T2 and T4.

Coliphages↗
PubMed1969

Influence of the conductivity of the discharge liquid on the microbicidal effect of transient electric arcs in aqueous systems.

The microbicidal effect of electrical discharges on microorganisms suspended in the discharge liquid was reduced when the liquid contained high concentrations of inorganic salts (conductivity k >/= 5 mmho/cm). A higher discharge voltage and a smaller distance between the submerged electrodes counteracted this reduction. The decrease in the microbicidal effect was accompanied by a change in the electrical current and by a decreased yield of microbicidal photons from the electric discharge.

Electric Conductivity↗