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F KLEIN

Publications and source records attributed to F KLEIN.

At least 19 recordsLinked to original sources
PubMed1965

QUANTITATIVE ASSAY FOR CRUDE ANTHRAX TOXINS.

Haines, Bertram W. (U.S. Army Biological Laboratories, Frederick, Md.), Frederick Klein, and Ralph E. Lincoln. Quantitative assay for crude anthrax toxins. J. Bacteriol. 89:74-83. 1965.-The whole crude toxins of Bacillus anthracis, although apparently responsible for the death of animals with anthrax, had never been quantitated. A total of 14 lots of the toxic culture filtrate of B. anthracis were pooled into one large lot of crude anthrax toxins. An extensive assay of this reference material was conducted in four laboratories by use of the time-to-death of the intravenously challenged Fischer 344 rat as the response variable. Doses of the material were varied factorially by concentration, dilution, and volume. The data from this study were used to define a potency unit of the crude anthrax toxins. Procedures were developed and illustrated for the assay of unknown lots of the toxins by comparing the rat time-to-death response to the unknown with either (i) the responses reported in this study, or (ii) directly with the rat responses to a new sample of the reference toxins. The possibilities and limitations of this standardization and of the statistical procedure through which it was developed are discussed.

Animals↗
PubMed1963

DUAL NATURE OF RESISTANCE MECHANISMS AS REVEALED BY STUDIES OF ANTHRAX SEPTICEMIA.

Klein, Frederick (Fort Detrick, Frederick, Md.), Bertram W. Haines, Bill G. Mahlandt, Ira A. DeArmon, Jr., and Ralph E. Lincoln. Dual nature of resistance mechanisms as revealed by studies of anthrax septicemia. J. Bacteriol. 85:1032-1038. 1963.-From studies of septicemic anthrax, resistance was described in relation to toxin and to growth of bacilli. This description was based on the observations that the terminal concentrations of bacilli in the blood were influenced primarily by the susceptibility of the host to toxin, whereas the death-response time of the host was dependent on both resistance to bacilli and toxin susceptibility. Resistance to the establishment and growth of infecting organisms and susceptibility to the toxin produced by growth of the bacilli are separate aspects of pathogenesis. A complete description of pathogenesis must accordingly treat of both these phenomena as individual entities.

Animals↗
PubMed1962

Anthrax toxin: causative agent in the death of rhesus monkeys.

Anthrax toxin was present in the blood obtained from rhesus monkeys at the terminal stage of anthrax and was also present in increasing amounts in the lymph as death approached. When sterile toxin produced in vitro was injected in sufficient amounts, monkeys died unless they were injected with specific antiserum. Death with symptoms of toxemia occurred within 2 hours after injection of 10(11) spores, whereas 10(10) spores or less required 20 or more hours of growth in vivo to cause death.

Animals↗
PubMed1962

Viability and estimation of shelf-life of bacterial populations.

Mathematical concepts associated with the exponential and probit models are developed, and the similarity of the two methods is discussed. Because of its greater flexibility in design, the probit method was used to estimate the shelf-life for four bacterial populations, wet and dry spores of Bacillus anthracis and wet and dry cells of Pasteurella tularensis. On the basis of data gained by storing these organisms at high temperature, the probit method was used to predict the time at which 50% viability would occur for cells stored at 3 C. A plane passing through a three-space showing change in percentage viability of bacteria was formulated by a multiple regression method. With this functional technique, the percentage viability, expressed as a probit, was linearily related to a logarithm of storage time and storage temperature. The use of this method to study the effect of controlled variables on the viability of cells is demonstrated by comparing the effect of viability associated with three additives used prior to drying. The results of the test gave shelf-life estimates which were too low for all additives; however, the order of stability was ranked properly as confirmed by long-term tests.

Bacillus anthracis↗