A limited survey of aflatoxins and fumonisins in retail maizebased products in the UK using immunoassay detection

A total of 27 maize-based products destined for human consumption were collected from retail outlets within the city of Glasgow in the UK and were analysed for the presence of aflatoxins using immunoaftinity column chromatography with fluorescence detection and for fumonisins by competitive ELISA. Aflatoxins were detected at a trace level below 4 in eight (30%) of the 27 samples tested, no sample contained aflatoxins at a high level although one sample of sweetcorn did contain aflatoxins at a level of 5-10 Fumonisins were detected in eight (30%) of the samples at levels from 1 to 8mgkg^-1 and a further eight samples contained fumonisin at a level below 1 mgkg^-1 but above the detectable level. The highest concentration of fumonisins was found in a sample of fine corn meal at 8-12mgkg^-1.     

Scats and den contents as indicators of the diet of stoats (Mustela erminea) in the Tasman Valley,South Canterbury,New Zealand

Stoats are significant predators of native fauna in New Zealand. They occur in many habitat types and consume a wide range of prey. The diet of stoats in the Tasman River, South Canterbury, was studied by analysis of scats and den contents. Analysis of 206 scats showed that stoats ate mainly lagomorphs, birds and invertebrates. Minor components included mice, lizards, fish and hedgehogs. Stoats ate more birds in spring than in autumn, and female stoats ate more invertebrates than did males. The contents of 219 dens collected in the same area at the same time provided further information. Birds and lagomorphs occurred at high frequency in dens, and other components were minor. Remains in dens were larger than in scats and allowed identification of many more prey items to species level. Den contents revealed a potentially substantial impact of stoats on threatened shorebirds locally; this impact was not detected by analysis of scats.     

Phospholipid composition of human monocytes and alterations occurring due to culture and stimulation by C3b

The phospholipid composition of human peripheral blood monocytes has not been previously reported, due to difficulty in isolating these cells in a purified state. In this study, monocytes were purified by counterflow centrifugation without selective adherence, and were characterized with the use of fluorescent monoclonal antibodies to T and B lymphocytes and monocytes by flow cytometry. These platelet-free cell preparations contained less than 5% T cells and less than 3% B cells. Isolated monocytes, which were rapidly frozen after isolation, contained phospholipids (in order of decreasing concentrations) as follows: phosphatidylcholine greater than phosphatidylethanolamine greater than sphingomyelin greater than phosphatidylserine greater than phosphatidylinositol greater than cardiolipin. A small amount of lyso-PC, but no lyso-PE, phosphatidic acid or lyso-PI, was found. The effect of culturing these cells in the presence or absence of a known stimulant of monocyte prostaglandin E and thromboxane release, the C3b fragment of the third component of human complement (C3), was studied with regard to phospholipid composition. Monocytes cultured without stimulant for 24 h contained 3-4% more sphingomyelin than did uncultured cells, and lyso-PC concentrations were consistently elevated. The addition of the stimulant C3b to cultured cells resulted in enhancement of release of immunoreactive prostaglandin E into culture supernatants, without affecting the release of lysosomal enzymes. Analysis of the phospholipid content of cells cultured in the presence of C3b revealed that there was a significant decrease in total PI compared to cells cultured in the absence of C3b, in addition to an increased concentration of sphingomyelin and lyso-PC when compared to freshly isolated cells. These changes occurred in the absence of elevated concentrations of phosphatidic acid.     

Lack of correlation of central nervous system inflammation and neuropathology with the development of seizures following acute virus infection

Infection of C57BL/6 mice by the intracerebral route with the Daniels (DA) strain of Theiler's murine encephalomyelitis virus (TMEV) resulted in acute behavioral seizures in approximately 50% of the mice. By titration, the viral dose correlated with the percentage of mice developing seizures; however, neuropathological changes were similar over the dose range, and viral clearance from the brains occurred uniformly by day 14 postinfection (p.i.). Other TMEV strains and mutants (GDVII, WW, BeAn 8386 [BeAn], DApBL2M, H101) induced seizures in C57BL/6 mice to various degrees. The BeAn strain and DApBL2M mutant were similar to the DA strain in the percentages of mice developing seizures and neuropathological changes and in the extent of infected cells. The GDVII and WW strains caused 100% mortality by days 5 and 6 p.i., respectively, at which time neuropathological changes and neuronal infection were extensive. The H101 mutant induced seizures and caused 100% mortality by day 7 p.i.; however, only minor neuropathological changes and few infected cells were observed. Thus, in H101 mutant infections, it appears that elevated levels of cytokines, rather than neuronal cell death, play the dominant role in seizure induction.     

A large-subunit mitochondrial ribosomal DNA sequence translocated to the nuclear genome of two stone crabs (Menippe)

Two DNA sequences that appear to be homologous to large-subunit mitochondrial ribosomal RNA genes have been identified in the stone crabs Menippe mercenaria and M. adina. Amplification from whole genomic DNA by polymerase chain reaction (PCR) with oligonucleotide primers based on conserved portions of large-subunit mitochondrial rRNA genes consistently amplified two products of similar length (565 and 567 bp). These products differed at 3% of their nucleotide bases, and could be distinguished by a HindIII site. Only one of these sequences (designated the A sequence) was detected by PCR in purified mitochondrial DNA. The other (designated the B sequence) hybridized to total genomic DNA at a level consistent with a nuclear genome location. It is unlikely that the type B product would have been recognized as a nuclear copy by examination of its sequence alone. This is the first report of a mitochondrial gene sequence translocated into the nuclear genome of a crustacean.      

Effects of carbon dioxide sequestration on California margin deep-sea foraminiferal assemblages

Deep-sea sequestration of CO₂ is being considered as a possible mitigation tool to decrease atmospheric CO₂ concentrations and its associated negative effects. This study investigated potential effects of liquid carbon dioxide (CO₂) injection on deep-sea foraminiferal assemblages. Foraminifera are ideal for this ecological impact investigation because of differing test composition (calcareous and non-calcareous) and thickness, and diverse epifaunal and infaunal depth preferences. The experiment was conducted on August–September 2003, at 3600 m off the coast of Monterey Bay, California, aboard the R/V Western Flyer using the ROV Tiburon. The pH of the site was monitored throughout the experiment. Sediment push-cores were collected (both from the experimental and control sites) and stained to distinguish live (stained) from dead (unstained) individuals. Effects of CO₂ injection on assemblages have been tracked both vertically (to 10 cm depth below sea floor) and horizontally (up to 10 m from CO₂ injection sites), as well as between live and dead individuals. Within corrals (containing the injected CO₂) and their underlying sediments, severe pH changes (near 4.0 units) were recorded. This compares with a record of small average reductions in ocean pH (− 0.05 units) combined with large episodic excursions (− 1.7 units) over the experimental area due to the injection of CO₂. Exposure to this gradient of low pH caused increased mortality and dissolution of calcareous forms within corrals, as far as 5 m from the injection site, and to at least 10 cm depth in the sediments.This experiment revealed several major effects of CO₂ injection on foraminiferal assemblages in surficial sediments: 1) total number of foraminifera in a sample decreases; 2) foraminiferal species richness decreases in both stained and unstained specimens; and 3) relative percentage of stained (live) forms in the remaining tests increases. Down-core trends (to 10 cm below sea floor) have revealed: 1) percent agglutinated forms decline and calcareous forms increase with depth; 2) agglutinated species richness decreases with depth; and 3) experimental core assemblages become increasingly similar with depth to those in control cores not subjected to CO₂ injection. These results imply almost complete initial mortality and dissolution in the upper 10 cm throughout the corrals following liquid CO₂ injection. Since calcareous foraminifera represent more than 50% of the total assemblages, this clearly indicates that emplacement of CO₂ will result in negative effects to diversity and survivorship of the deep-sea benthic meiofauna.     

Made in America: Immigrant Students in Our Public Schools

Made in America: Immigrant Students in Our Public Schools. Laurie Olsen New York: The New Press, 1997. 276 pp.