Local leukocyte mobilization in irradiated or cyclophosphamide-treated rats

Summary Sprague-Dawley rats made neutropenic by⁶⁰Co irradiation or cyclophosphamide treatment retained a limited capacity for mounting a local leukocyte mobilization (LLM) response. Rats irradiated with 700 rad⁶⁰Co lacked an LLM. Rats treated with 100 mg/kg cyclophosphamide showed no LLM following an initial low response when assayed originally.We wish to thank Mr Dane Walden for excellent technical assistance. This work was supported by Armed Forces Radiobiology Research Institute, Defense Nuclear Agency, under Research Work Unit MJ 60212. The views presented in this paper are those of the authors. No endorsement of the Defense Nuclear Agency has been given or should be inferred.     

Effects of high gravity on amoebae (Pelomyxa carolinensis). I. Division rates

Zusammenfassung Amöben (Pelomyxa carolinensis), die einem Gravitationsstress von 10 bis 54 g/h ausgesetzt wurden, waren in ihrer Teilungsrate signifikant behindert.

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We wish to acknowledge the National Aeronautics and Space Administration, USA for support of this study.     

Site attachment of a protelean parasite (Erythraeidae:Leptus sp.)

Summary Leptus sp. showed no site preference when they attached to an insect host. After the chelicera penetrated the host's cuticle a substance was secreted to cement the mite to its host.     

Backbone structure of the infectious epsilon15 virus capsid revealed by electron cryomicroscopy

A half-century after the determination of the first three-dimensional crystal structure of a protein, more than 40,000 structures ranging from single polypeptides to large assemblies have been reported. The challenge for crystallographers, however, remains the growing of a diffracting crystal. Here we report the 4.5-A resolution structure of a 22-MDa macromolecular assembly, the capsid of the infectious epsilon15 (epsilon15) particle, by single-particle electron cryomicroscopy. From this density map we constructed a complete backbone trace of its major capsid protein, gene product 7 (gp7). The structure reveals a similar protein architecture to that of other tailed double-stranded DNA viruses, even in the absence of detectable sequence similarity. However, the connectivity of the secondary structure elements (topology) in gp7 is unique. Protruding densities are observed around the two-fold axes that cannot be accounted for by gp7. A subsequent proteomic analysis of the whole virus identifies these densities as gp10, a 12-kDa protein. Its structure, location and high binding affinity to the capsid indicate that the gp10 dimer functions as a molecular staple between neighbouring capsomeres to ensure the particle's stability. Beyond epsilon15, this method potentially offers a new approach for modelling the backbone conformations of the protein subunits in other macromolecular assemblies at near-native solution states.