A pilot to examine the logistical and feasibility issues in testing deceased tissue donors for vCJD using tonsil as the analyte

Transplanted tissues have transmitted transmissible spongiform encephalopathies and in the UK there have been more cases of variant Creutzfeldt-Jakob disease (vCJD) than elsewhere in the world. A pilot study was undertaken to look at the feasibility of testing for vCJD in deceased donors using tonsillar tissue. This pilot showed that obtaining consent for removal and testing tonsil tissue was feasible. Donor eligibility for inclusion in the pilot was limited to tissue donors from the National Health Service Blood and Transplant, Tissue Services and to donors shared with the Corneal Transplant Service Eye Banks. Obtaining tonsillar tissue in the immediate post–mortem period was limited by the presence of rigor mortis. Tonsillar tissue was suitable for routine analysis for the presence of prion associated with vCJD in deceased tissue donors. Production and processing of tissue was straightforward and a low assay background was obtained from most samples. Since palatine and lingual tonsil tissue can be obtained in pairs it was possible, in the majority of cases, to set aside an intact sample for confirmatory testing if required. In one instance a sample was reactive by Western blot. However, the pattern of reactivity was not typical for that obtained from vCJD patients. Unfortunately the sample was not of sufficient quality for the confirmatory test to provide a conclusive result.     

Imaging of metabolites using secondary ion mass spectrometry

This article provides an overview of the technique of secondary ion mass spectrometry imaging and highlights some current and future areas of application relevant to the field of metabolomics. The approach benefits from label-free analysis of molecular species up to ~1500 Da with minimal sample preparation. Offering the highest spatial resolution of current mass spectrometry imaging methodologies, the technique is well-suited to metabolite imaging in both biological tissue and cells, in both 2D and 3D.

     

Differences in the diurnal and nocturnal use of intertidal feeding grounds by Redshank Tringa totanus

Capsule Redshank used more sites and had larger ranges at night than during the day.

Aims To determine whether there were differences in how wintering Redshank used intertidal feeding grounds during the day and night.

Methods The movements of 38 Redshank caught and radiotagged at two neighbouring sites on the Severn Estuary were monitored during four different study periods between January 1997 and October 1999.

Results Individuals used a greater number of sites at night than in the day (on average, two as opposed to one). Kernel home range analyses also indicated that individuals used larger core areas and home ranges at night. In addition, there was a significant difference between the sizes of ranges of birds caught at two neighbouring sites. One foraging site was almost entirely avoided during the day, probably due to disturbance from an adjacent heliport, but was used by the majority of individuals at night when the heliport was unused. This site was rich in invertebrates as a result of the high organic and nutrient input from a sewage outfall pipe. Redshank also used riverine mudflats less during the night, preferring more open mudflats – perhaps to avoid nocturnal predators.

Conclusions Comparison with previous studies suggests that the importance of sites predominantly used at night and the total extent of the areas used by waders may be underestimated by studies that rely on daytime surveys alone. It is important, therefore, that information on nocturnal distributions should be available to inform decisions on site management and protection.     

Conformation of MeAla6-cyclosporin A by NMR. Relationship of sidechain orientation of the MeBmt-1, MeLeu-9, and MeLeu-10 residues to immunosuppressive activity

MeAla6-cyclosporin A (MeAla6-CsA) is a unique CsA analog that shows weak immunosuppressive activity and yet binds strongly to the proposed cytosolic protein receptor, cyclophilin (CyP). Preliminary 1H NMR data showed significant chemical shift differences between spectra of MeAla6-CsA and CsA, suggesting different preferred conformations. A more detailed study, however, revealed that the backbone conformations of the two molecules are essentially identical, and that the differences can be accounted for, principally, by the sidechain motions of the MeBmt-1, MeLeu-9, and -10 residues. ROE and coupling constant data show that in MeAla6-CsA, the preferred chi 1 rotamers for MeLeu-9 and -10 are + 180 degrees (T), whereas in CsA there is a more even distribution of rotamer populations for MeLeu-10, and a preferred -60 degrees (G-) chi 1 rotamer for MeLeu-9. Similar data argue that the sidechain of MeBmt-1 is more restricted in its motion in MeAla-CsA than in CsA. Temperature studies suggest that these preferred rotamers for MeAla6-CsA may increase the stability of the hydrogen bond between NH(7) and CO(11), but prevent particular residues, especially the essential MeBmt-1 sidechain, from adopting orientations required to elicit immunosuppressive activity. The significant changes observed in the preferred orientations for the sidechains of the MeBmt-1, MeLeu-9, and MeLeu-10 residues in MeAla6-CsA argue that the particular orientations which they assume in CsA are not essential for cyclophilin binding.     

Factors affecting corticosteroid concentrations in yellow-bellied marmots.

1. Bound and total corticosteroid concentrations of yellow-bellied marmots (Marmota flaviventris) were lowest in May after emergence from hibernation and peaked in August prior to immergence. 2. Total corticosteroids were affected by age but not by sex or reproductive status. 3. There was no consistent relationship between measures of population density and concentrations of corticosteroids; when a significant relationship occurred, only 22-34% of the variation was explained. 4. Social status and social behavior were the major factors affecting corticosteroid concentrations.     

Comparison of the fecundity of three species of grain store mites on fungal diets

The egg production of isolated pairs ofAcarus siro, Glycyphagus destructor andTyrophagus longior fed on a control diet of wheatgerm and yeast was compared with that on mycelial pellets from shake cultures ofCladosporium cladosporiodes, Aspergillus repens, A. ruber andPenicillium cyclopium as well as spores ofP. cyclopium andA. repens. The mites always produced fewer eggs on the fungal diets than on the ideal diet.Tyrophagus longior usually did best of the three mite species on the fungal diets, andG. destructor worst.Aspergillus ruber proved the most suitable fungus for all mite species, whileC. cladosporiodes was the least suitable. Spores were a less suitable diet than mycelial pellets from shake cultures, which were predominantly mycelium.