Colony attendance and censusing of Black Guillemots Cepphus grylle in Shetland

The diurnal rhythm of colony attendance by Black Guillemots varied seasonally. No tidal effects were detected but in April attendance was lower when winds exceeded force 4. Numbers were most stable during 05.00–08.00 GMT in the pre-breeding period. Counts at this time and in winds of force 4 or less provide the best estimate of adult populations. Between late March and mid-May, counts of adults associated with breeding habitat account for most birds occupying suitable nest sites and censuses in northern Britain should be conducted in this period. As the proportion of non-breeding adults varies between colonies, no universal correction factor can be used to estimate the number of breeding attempts from counts of birds. Counts aimed at detecting maximum attendance provide greater accuracy than single counts made by flushing all birds on to the sea but take longer. Monitoring units should be stretches o-f coastline that include a number of colonies of different sizes.     

Two-dimensional maps of short-term albumin uptake by the immature and mature rabbit aortic wall around branch points

In children, aortic lipid deposition develops in triangular regions of the wall downstream of branch points, whilst in adults these regions are particularly free of disease. Comparable age-related patterns occur in rabbit aortas. They may be explained by patterns of wall permeability to circulating macromolecules: along the longitudinal midline through branches, permeability is greater downstream than upstream in immature rabbits, but is greater upstream at later ages. Here we have mapped permeability in detail around such branches, not just along the midline. Short-term uptake of rhodamine-labeled albumin, measured using digital imaging fluorescence microscopy of serial sections, was greatest in an approximately triangular region downstream of immature branches, but in mature animals it was greater upstream, particularly away from the midline, and in streaks to the side of branches. Hence the maps are consistent with earlier permeability data and closely resemble the patterns of disease.     

Reversible and irreversible interactions between elastin and plasma lipoproteins

The interactions between radiolabeled, human plasma lipoproteins and elastin derived from bovine ligamentum nuchae were investigated using a washout technique. The interaction was characterised by Ki, a coefficient of irreversible binding, and Kr, the reversible partition coefficient. For both low-density lipoproteins (LDL) and high-density lipoproteins (HDL) the Ki values decreased as total lipoprotein concentration increased, suggesting that the binding is saturable, and were similar in magnitude to those measured by other workers using elastin derived from the human aorta. For both LDL and HDL the Kr values were independent of lipoprotein concentration in the range 0.1 microgram/ml-1.5 micrograms/ml. At a total protein concentration of 1.5 mg/ml in the incubation medium, the reversible interactions were comparable in magnitude to the irreversible.     

Hurler's, Hunter's and Morquio's syndromes. A biochemical study in the light of current views of the underlying defects

Glycosaminoglycans were isolated from the urine of three patients with Hurler's, Hunter's and Morquio's syndromes and also from the liver and spleen of the case of Hurler's syndrome by a procedure avoiding further degradation. A method of determining the proportions of dermatan sulphate, heparan sulphate and chondroitin sulphate in each preparation is described. The relative proportions of these glycosaminoglycans in the urine and organs of the case of Hurler's syndrome were very similar. Glycosaminoglycans from the organs were of much lower molecular weight than normal, consisting of single chains of molecular weight about 5000 together with multiples of up to four such chains attached to peptide moieties. The linkage region normally attaching glycosaminoglycan chains to protein in whole protein–polysaccharides of connective tissue was degraded progressively towards serine. The total output and relative proportions of abnormal glycosaminoglycans in the urine were compared in two brothers with Hunter's syndrome examined on two occasions 4 years apart. At comparable ages they excreted about the same amount, and the relative proportions of each glycosaminoglycan remained essentially constant. The composition and chromatographic behaviour of the glycosaminoglycan in the urine from the case of Morquio's syndrome indicated that it consisted of material containing about one-third keratan sulphate and two-thirds chondroitin sulphate as part of the same molecule, as in proteoglycans of cartilage. The total output of glycosaminoglycans, although higher than normal, was considerably less than in other types of Mucopolysaccharidoses.     

Techniques for quantifying effects of dietary antioxidants on transcription factor translocation and nitric oxide production in cultured cells

Dietary antioxidants can affect cellular processes relevant to chronic inflammatory diseases such as atherosclerosis. We have used non-standard techniques to quantify effects of the antioxidant soy isoflavones genistein and daidzein on translocation of Nuclear Factor-KB (NF-KB) and nitric oxide (NO) production, which are important in these diseases. Translocation was quantified using confocal immunofluoresecence microscopy and ratiometric image analysis. NO was quantified by an electrochemical method after reduction of its oxidation products in cell culture supernatants. Activation of the RAW 264.7 murine monocytel macrophage cell line increased the ratio of nuclear to cytoplasmic immunostaining for NF-kappaB. The increase was exacerbated by pre-treatment with genistein or daidzein. To show that decreases could also be detected, pre-treatment with the pine bark extract Pycnogenol(R) was examined, and found to reduce translocation. NO production was also increased by activation, but was reduced by pre-treatment with genistein or daidzein. In the EA.hy926 human endothelial cell line, constitutive production was detectable and was increased by thrombin. The confocal and electrochemical methods gave data that agreed with results obtained using the established electromobility shift and Griess assays, but were more sensitive, more convenient, gave more detailed information and avoided the use of radioisotopes.     

The diet of Herring Gulls (Larus argentatus) during winter and early spring on the lower Great Lakes

In the Great Lakes, the Herring Gull (Larus argentatus) is a prominent member of the aquatic bird community, and has been used to monitor spatial and temporal trends in contaminant levels. To understand more fully contaminant loading outside the breeding season, we analysed the contents of 1298 freshly regurgitated pellets and 179 fresh faeces, collected in March and early April 1978–83, and between late December and late February 1990–91, from the vicinity of breeding colonies in Lakes Ontario and Erie, the Niagara River, Detroit River, and south-eastern parts of Lake Huron. Most adult Herring Gulls from the Great Lakes population winter in these areas, but there is no published account of their food habits other than during the breeding season. Most pellets from colonies close to large urban centres contained remains of garbage, as well as various fish species. Small mammals, notably Deer Mice (Peromyscus maniculatus) dominated the early spring diet at Lake Huron colonies near agricultural areas. At all other sites fish predominated in pellets and faeces, but garbage items were also recorded regularly. The species of fish consumed varied regionally, probably reflecting local availability. In Lake Ontario, Rainbow Smelt (Osmerus mordax) and Alewife (Alosa pseudoharengus) occurred most frequently in samples, whereas Freshwater Drum (Aplodinotus grunniens) was the main fish prey in Lake Erie and the Detroit River. Dietary differences were apparent between years, within seasons, and amongst areas. While these may have reflected some real differences in food availability, interpretation of these results was confounded by various biases inherent in the sampling of pellets and faeces to determine diet in such an opportunistic species. Therefore, it would be unwise to draw rigid conclusions as to regional or seasonal differences in the diets of piscivorous birds, based upon analyses of diet from only a small sample of sites or years. Herring Gulls appear to feed mainly on fish and garbage in winter and early spring on the lower Great Lakes (much as during the breeding season), but any locally abundant food source is probably exploited opportunistically.     

Effect on Exclusion of Alterations to the Sex Pilus

Chromosomal genes from an Hfr donor, dependent for their transfer upon the integrated F factor, were not excluded by an F(+) recipient when the donor also carried an F-like R factor, and its sex pili contained, in addition to F pilin, another pilin of a different specificity.