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Previous studies indicate that limiting tyrosine and phenylalanine intake in the diet decreases tumor growth and metastasis. General health status, immune status, and platelet function were studied in nine healthy human subjects consuming low-protein foods supplemented with formula diets free of tyrosine and phenylalanine to maintain total daily intake of tyrosine at 2.4 mg/kg body wt and phenylalanine at 3.5 mg/kg body wt. This regimen decreased plasma tyrosine (p less than 0.05) but not phenylalanine. Blood indicators of protein status were not changed. Platelet aggregation decreased in response to adenosine diphosphate and platelet activating factor in seven of nine subjects. Natural killer, T-helper, and T-cytotoxic/suppressor lymphocyte numbers proportionally increased relative to neutrophils (p less than 0.05). Natural killer cell activity increased in six of nine subjects. Increased natural killer cell activity and decreased platelet aggregation are two indices associated with decreased tumor growth and metastasis.

Direct probe mass spectrometry of single colonies of different bacteria produced spectra which could be distinguished by calculations based on the intensities of 25 selected ions. Direct probe mass spectrometry has enormous potential as a rapid technique for characterizing micro-organisms.

The discrimination of a set of 53 strains, taken from four closely related Bacillus species (Bacillus subtilis, B. pumilus, B. licheniformis and B. amyloliquefaciens), was examined using pyrolysis mass spectrometry. Strains were grown on six different media to examine the effect of media variation, especially batch-to-batch variation of a single medium, on the pyrolysis mass spectra and strain discrimination achieved. Long-term reproducibility over a period of 14 months was also examined. It was shown that batch-to-batch media variation is insufficient to affect spectra and strain discrimination significantly, but different media types do affect this. It was shown that species groups could still be recovered from the data, however, with an appropriate data-handling system. It was not possible to directly compare spectra produced 14 months apart, but the strain and species discrimination achieved using each data-set were highly comparable.

The electron spin echo modulation spectrum of organic radicals in randomly oriented solids is analyzed in detail for axially symmetric hyperfine tensors. Numerical calculations of the modulation spectra are compared with experimental results from the radical cations of 15N labeled bacteriochlorophyll a and the primary donor of photosynthetic bacterium Rhodospirillum rubrum. Determination of hyperfine coupling constants from experimental spectra in the frequency domain is complicated by the anisotropy of modulation intensity, the effects of second and higher order hyperfine interactions, overlapping spectra from several nuclei, multiple quantum coherences among hyperfine levels, and the spectrometer deadtime. Nonlinear least‐squares analysis of the time domain data [Tang et al., J. Chem. Phys. 83, 4197 (1985)] is the only reliable method for extracting coupling constants from randomly oriented organic radicals.

Eight strains each of Bacillus subtilis, Bacillus pumilus, Bacillus licheniformis, and Bacillus amyloliquefaciens were analyzed by using pyrolysis gas-liquid chromatography. Statistical analysis with canonical variates gave four well-separated groups, which represented the four species. Further analysis of the same strains by deoxyribonucleic acid-deoxyribonucleic acid hybridization and API identification systems confirmed the discrimination obtained with pyrolysis gasliquid chromatography. However, analysis by biochemical tests performed in the classical way gave only three groups since it was not possible to achieve separation of the strains representing B. subtilis from those of B. amyloliquefaciens when these tests were used.

The design and operation of a time‐resolved electron spin echo spectrometer suitable for detecting transient radicals produced by 3 MeV electron radiolysis is described. Two modes of operation are available: Field swept mode which generates a normal EPR spectrum and kinetic mode in which the time dependence of a single EPR line is monitored. Techniques which may be used to minimize the effects of nonideal microwave pulses and overlapping sample tube signals are described. The principal advantages of the spin echo method over other time‐resolved EPR methods are: (1) Improved time resolution (presently ∼30–50 nsec) allows monitoring of fast changes in EPR signals of transient radicals, (2) Lower susceptibility to interference between the EPR signal and the electron beam pulse at short times, and (3) Lack of dependence of transient signals on microwave field amplitude or static field inhomogeneity at short times. The performance of the instrument is illustrated using CIDEP from acetate radical formed in puls...

SUMMARY: The existence of subgroups within Bacillus megaterium has been reported previously on the basis of DNA-DNA hybridization and DNA base composition studies. In this study the strains used to define these subgroups have been reanalysed by pyrolysis gas-liquid chromatography. The resultant two-group classification of the test strains was directly comparable with that obtained from the previous nucleic acid analyses at the between-group level. However, comparisons of the test strains at the within-group level proved less successful.

Summary. Thin sections of methane-utilizing bacteria have been examined in the electron microscope and the fine structure of the cells is described for the first time. The outstanding feature of all the isolates studied is the existence of intracellular membrane structures resembling those seen in nitrifying and photosynthetic bacteria. The possible significance of these membranes is discussed.

Summary Starch gel electrophoresis showed that Bacillus cereus esterase and catalase are not single enzymes but multimolecular species and that they undergo changes during sporulation. Heat resistant spore catalase was detected in vegetative cells before mature spores were present.

Calcium was essential for the growth of A. vinelandii, A. chroococcum, A. beijerinckii and A. insigne in the presence and absence of combined nitrogen. A. agile and A. macrocytogenes were able to grow in the absence of calcium but growth was stimulated by the cation. Calcium could be replaced by strontium at roughly the same molar concentration. The authors present evidence suggesting that the calcium sparing effect of ammonium and sodium acetates reported in the literature may be dependent on the size of inoculum used.

SUMMARY: The ‘negative contrast method’ was used to study by electron microscope four previously described Bacillus cereus bacteriophages. The main features of the structure of these phages are described and the observations corrected with similar work on phages associated with other genera.

SUMMARY: The use of pyrolysis mass spectrometry in the characterization and identification of Bacillus species was studied. Fifty-three strains of four closely related groups, Bacillus subtilis, B. pumilus, B. licheniformis and “B. amyloliquefaciens”, were used in a study of both sporulated and non-sporulated cultures. Pyrolysis was carried out using a Pyromass 8-80, a novel pyrolysis mass spectrometer specifically designed for fingerprinting complex samples. The pyrolysis data obtained were analysed using multivariate statistical techniques. All four groups could be differentiated using data from non-sporulated cultures but the data from sporulated cultures did not separate B. subtilis from “B. amyloliquefaciens” or B. pumilus. In contrast, B. licheniformis was more clearly differentiated from the other three species using these data. Culture maturity affected the mass spectra obtained from non-sporulated cultures.

Low resolution pyrolysis gas-liquid chromatography could differentiate the following groups of Clostridium botulinum and related organisms: (1) Cl. botulinum type A. proteolytic types B and F and Cl. sporogenes; (2) Cl. botulinum types C and D. and (3) Cl. botulinum type E and non-proteolytic types B and F. Toxin types A and B could be distinguished from type E and from type F.

Summary. The morphologies of 4 new bacteriophages active against various strains of Bacillus thuringiensis have been examined by electron microscopy. The sensitivity patterns to these bacteriophages of B. thuringiensis strains and of other Bacillus spp. are described.

Summary A soil perfusion apparatus is described which features an enclosed system of small size. It has been successfully used to isolate micro-organisms capable of utilizing various aromatic compounds as sole sources of carbon and energy.