Search PubMed⌕ Search

Biomedical subjects

W D Taylor

Publications and source records attributed to W D Taylor.

At least 55 records · Page 3Linked to original sources
PubMed1980

Characteristics of a new bacteriophage, Psp231a, infecting Pseudomonas phaseolicola HB10Y.

Bacteriophage Psp231a infects Pseudomonas phaseolicola, strain HB10Y, which is the host cell for the enveloped bacteriophage phi 6. This paper describes the biophysical characteristics of Psp231a and the physical properties of its nucleic acid. In electron micrographs the virion appears as an icosahedral structure, approximately 55 nm in diameter, with a short tail. The virion density is 1.48 g/cm3 in CsCl, and the sedimentation coefficient is approximately 407S. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed the presence of 12 polypeptides ranging in molecular weight from 5,000 to 117,000. The nucleic acid of Psp231a is linear, double-stranded DNA of molecular weight 28 X 10(6). Its density in CsCl is 1.716 g/cm3, and its sedimentation coefficient in 3 M CsCl is 20.0S, corresponding to an S020,W of 34S.

Bacteriophages↗
PubMed1976

Pathology of goats and sheep experimentally infected with Mycoplasma mycoides var. capri.

Twenty goats and four sheep were experimentally infected with Mycoplasma mycoides var. capri and examined histopathologically. Death occurred or a moribund state developed in most of them within a week after parenteral inoculation with mycoplasmas. Histopathological examination revealed severe serofibrinous inflammation on the serosa and interstitial connective tissue at the site of inoculation. Marked inflammatory edema with infiltrating polymorphs was found in the early stage of infection. As the infection progressed, the lesion became a cellulitis; necrosis, sometimes with focal liquefaction, was a constant feature. Organization with infiltration by lymphocytes and histiocytes had begun in some tissues. Acutely infected organs had evidence of systemic involvement. Lesions included splenitis, lymphadenitis, meningitis, metastatic foci in the intestine and urinary bladder, and parenchymatous degeneration in the liver, heart, and kidneys. Mycoplasmas were isolated from many tissues of critically ill animals. Other goats which had received mycoplasmas by instillation escaped severe illness. Even so, mycoplasmas were isolated from one or two of their tissues at necropsy. The great variation in clinical and pathological response was apparently dependent upon the route of inoculation. Recovery of mycoplasmas from two contact control goats which remained healthy is suggestive of the clinically undectable carrier state. As other workers have reported, the clinical and pathological changes in sheep were similar to those in parenterally inoculated goats.

Animals↗
PubMed1975

Near-ultraviolet light-induced strand breaks in DNA pretreated with the carcinogen, N-acetoxy-2-acetylaminofluorene.

Neutral sucrose gradients of supercoiled DNA (phiX-174 RF I) were used to measure the in vitro production of strand breaks by the carcinogen, N-acetoxy-2-acetylaminofluorene (AcO-AAF). Treatment with AcO-AAF in 10% dimethyl sulfoxide did not directly yield strand breaks. Breaks in relatively low yield appeared after alkali treatment (pH 13, 60 min) of the RF I previously reacted with AcO-AAF. The DNA treated with AcO-AAF was sensitive to single-strand breakage by 303 nm near-ultraviolet light under neutral conditions. The greater the prior AcO-AAF treatment, the greater the sensitivity to 303 nm light. Post-irradiation alkali treatment greatly enhanced the light-induced strand breakage.

Acetoxyacetylaminofluorene↗
PubMed1972

Development of bacteriophage alpha. II. Dependence on the host ribonucleic acid polymerase.

Measurements of ribonucleic acid (RNA) synthesis using (14)C-uracil uptake in rifampin-sensitive and rifampin-resistant strains of Bacillus megatherium were carried out after infection of the bacteria with bacteriophage alpha. Phage development was inhibited in the former but not the latter strain, showing that alpha phage development is dependent on the bacterial host RNA polymerase. This dependence exists at all times during eclipse. RNA polymerase extracts showed the same in vitro rifampin sensitivity as the corresponding bacterial strains.

Bacillus megaterium↗
PubMed1968

Stability of radiation-induced organic free radicals. Decay by heat.

The rate of free radical decay was measured at various temperatures using electron paramagnetic resonance spectroscopy. Rate constants determined from first-order decay kinetics were used to determine the activation energy for the process of free radical decay. The similarity between the temperature dependence of free radical decay by heat and that of electrical conductivity has led us to consider the possibility that the two processes may be related. Mechanisms by which a population of electron-hole conducting states may lead to free radical decay are outlined and experimental data relating to these mechanisms are discussed.

Alanine↗