Polyacetylenes from the fruits of Hedera helix

The fruits of Hedera helix afforded, in addition to the known polyacetylenes falcarinone and falcarinol, a polyacetylenic epoxide closely related to panaxydol. The structure of the epoxide was determined by spectral methods to be (Z)-9,10-epoxy-1-heptadecene-4,6-diyn-3-one.     

Strong Seasonality of Marine Microbial Eukaryotes in a High-Arctic Fjord (Isfjorden,in West Spitsbergen,Norway)

The Adventfjorden time series station (IsA) in Isfjorden, West Spitsbergen, Norway, was sampled frequently from December 2011 to December 2012. The community composition of microbial eukaryotes (size, 0.45 to 10 μm) from a depth of 25 m was determined using 454 sequencing of the 18S V4 region amplified from both DNA and RNA. The compositional changes throughout the year were assessed in relation to in situ fjord environmental conditions. Size fractionation analyses of chlorophyll a showed that the photosynthetic biomass was dominated by small cells (<10 μm) most of the year but that larger cells dominated during the spring and summer. The winter and early-spring communities were more diverse than the spring and summer/autumn communities. Dinophyceae were predominant throughout the year. The Arctic Micromonas ecotype was abundant mostly in the early-bloom and fall periods, whereas heterotrophs, such as marine stramenopiles (MASTs), Picozoa, and the parasitoid marine alveolates (MALVs), displayed higher relative abundance in the winter than in other seasons. Our results emphasize the extreme seasonality of Arctic microbial eukaryotic communities driven by the light regime and nutrient availability but point to the necessity of a thorough knowledge of hydrography for full understanding of their succession and variability.     

Progressive atrophy of the thymus in mice carrying Lewis lung carcinoma grafts

Summary A rapid and progressive thymus atrophy in B₆D₂ mice following transplantation of Lewis lung carcinoma cells is reported. Spleen weight, however, increased in tumor-carrying animals. Tumor extracts failed to induce these alterations. The mechanism of these perturbations of the immune system in tumor-carrying animals is discussed.This work was supported by the Norwegian Cancer Society     

Stereological estimates of nuclear volume correlated with histopathological grading and prognosis of bladder tumour

The aim of this retrospective study is to provide morphometric data which make grading of urinary bladder tumours objective and reproducible by stereological estimation of nuclear volume using the principle of estimating of the volume of particles of arbitrary shape. The study includes 92 specimens: 12 from normal bladder mucosa, and 80 from bladder tumours (15 grade I, 45 grade II, 19 grade III and one grade IV according to Bergkvist et al. 1965). After standard fixation, embedding, sectioning and hematoxylin-eosin staining, an unbiased estimate of the mean volume of nuclei sampled with a change proportional to the volume: (Formula: see text) was calculated. Here l0 is the length of the intercept through a test point hitting a nucleus measured in a random direction through the test point. The weighted means of nuclear volume in bladder tumours are spread over a wide range and show a strong correlation with the Bergkvist grade. Moreover, the relationship between the weighted mean volume of nuclei in bladder tumours and the prognosis is very good. Only one of 35 patients with a mean nuclear volume below 300 micron 3 died of bladder cancer whereas 18 of 19 patients with a mean nuclear volume above 500 micron 3 developed invasives tumours or died of their disease. This simple and fast estimate of nuclear volume seems to provide objective data of high prognostic value.     

Adult polyphagous coleopterans overwintering in cereal boundaries: winter mortality and susceptibility to the entomopathogenic fungus Beauveria bassiana

Autumn-collected Bembidion lampros and Agonum dorsale were kept outdoors under semi field conditions to determine winter mortality. On three occasions (autumn, mid-winter and late winter) sub-samples of the population were incubated in the laboratory at room temperature and mortality was recorded. Generally the mortality was low in autumn and mid-winter, not exceeding 5%. A more pronounced post-winter mortality of up to 30% was observed at the end of hibernation. Only a negligible number were infected by the entomopathogenic fungi Beauveria bassiana and Paecilomyces farinosus. Infection experiments with B. bassiana isolates from Sitona lineatus, Tachyporus hypnorum and three species of ground beetles showed a similarly low susceptibility of B. lampros and A. dorsale to B. bassiana and, although Tachyporus spp. showed a distinct mycophagy and a significantly higher mortality, this could not be related to mycosis.     

Affinity maturation of a novel antagonistic human monoclonal antibody with a long VH CDR3 targeting the Class A GPCR formyl-peptide receptor 1

Therapeutic monoclonal antibodies targeting G-protein-coupled receptors (GPCRs) are desirable for intervention in a wide range of disease processes. The discovery of such antibodies is challenging due to a lack of stability of many GPCRs as purified proteins. We describe here the generation of Fpro0165, a human anti-formyl peptide receptor 1 (FPR1) antibody generated by variable domain engineering of an antibody derived by immunization of transgenic mice expressing human variable region genes. Antibody isolation and subsequent engineering of affinity, potency and species cross-reactivity using phage display were achieved using FPR1 expressed on HEK cells for immunization and selection, along with calcium release cellular assays for antibody screening. Fpro0165 shows full neutralization of formyl peptide-mediated activation of primary human neutrophils. A crystal structure of the Fpro0165 Fab shows a long, protruding V_H CDR3 of 24 amino acids and in silico docking with a homology model of FPR1 suggests that this long V_H CDR3 is critical to the predicted binding mode of the antibody. Antibody mutation studies identify the apex of the long V_H CDR3 as key to mediating the species cross-reactivity profile of the antibody. This study illustrates an approach for antibody discovery and affinity engineering to typically intractable membrane proteins such as GPCRs.