Enzymatic and cellular responses in relation to body burden of PAHs in bivalve molluscs: a case study with chronic levels of North Sea and Barents Sea dispersed oil.

Mytilus edulis and Chlamys islandica were exposed to nominal dispersed crude oil concentrations in the range 0.015-0.25 mg/l for one month. Five biomarkers (enzymatic and cellular responses) were analysed together with bioaccumulation of PAHs at the end of exposure. In both species, PAH tissue residues reflected the exposure concentration measured in the water and lipophilicity determined the bioaccumulation levels. Oil caused biomarker responses in both species but more significant alterations in exposed C. islandica were observed. The relationships between exposure levels and enzymatic responses were apparently complex. The integrated biomarker response related against the exposure levels was U-shaped in both species and no correlation with total PAH body burden was found. For the monitoring of chronic offshore discharges, dose- and time-related events should be evaluated in the selection of biomarkers to apply. From this study, cellular damages appear more fitted than enzymatic responses, transient and more complex to interpret.

Cerebellar leukoencephalopathy: most likely histiocytosis-related.

BACKGROUND: Histiocytosis, both Langerhans and non-Langerhans cell type, can be associated with cerebellar white matter abnormalities, thought to be paraneoplastic. The associated clinical picture consists of ataxia, spasticity, and cognitive decline. Hormonal dysfunction is frequent. MRI shows cerebellar white matter abnormalities, as well as brainstem and basal ganglia abnormalities. This so-called "neurodegenerative syndrome" may occur years before or during manifest histiocytosis and also years after cure. We discovered similar MRI abnormalities in 13 patients and wondered whether they could have the same syndrome. METHODS: We reviewed the clinical and laboratory information of these 13 patients and evaluated their brain MRIs. Seven patients underwent spinal cord MRI. RESULTS: All patients were isolated cases; 10 were male. They had signs of cerebellar and pyramidal dysfunction, behavioral problems, and cognitive decline. MRI showed abnormalities of the cerebellar white matter, brainstem, basal ganglia, and, to a lesser extent, cerebral white matter. Three patients had spinal cord lesions. Three patients had laboratory evidence of hormonal dysfunction. No evidence was found of an underlying metabolic defect. In two patients biopsy of nodular brain lesions revealed histiocytic infiltrates. CONCLUSIONS: Considering the striking clinical and MRI similarities between our patients and the patients with this neurodegenerative syndrome in the context of proven histiocytosis, it is likely that they share the same paraneoplastic syndrome, although we cannot exclude a genetic disorder with certainty. The fact that we found histiocytic lesions in two patients substantiates our conclusion. Patients with cerebellar white matter abnormalities should be monitored for histiocytosis.

The adult plant rust resistance loci Lr34/Yr18 and Lr46/Yr29 are important determinants of partial resistance to powdery mildew in bread wheat line Saar.

Powdery mildew, caused by Blumeria graminis f. sp. tritici is a major disease of wheat (Triticum aestivum L.) that can be controlled by resistance breeding. The CIMMYT bread wheat line Saar is known for its good level of partial and race non-specific resistance, and the aim of this study was to map QTLs for resistance to powdery mildew in a population of 113 recombinant inbred lines from a cross between Saar and the susceptible line Avocet. The population was tested over 2 years in field trials at two locations in southeastern Norway and once in Beijing, China. SSR markers were screened for association with powdery mildew resistance in a bulked segregant analysis, and linkage maps were created based on selected SSR markers and supplemented with DArT genotyping. The most important QTLs for powdery mildew resistance derived from Saar were located on chromosomes 7DS and 1BL and corresponded to the adult plant rust resistance loci Lr34/Yr18 and Lr46/Yr29. A major QTL was also located on 4BL with resistance contributed by Avocet. Additional QTLs were detected at 3AS and 5AL in the Norwegian testing environments and at 5BS in Beijing. The population was also tested for leaf rust (caused by Puccinia triticina) and stripe rust (caused by P. striiformis f. sp. tritici) resistance and leaf tip necrosis in Mexico. QTLs for these traits were detected on 7DS and 1BL at the same positions as the QTLs for powdery mildew resistance, and confirmed the presence of Lr34/Yr18 and Lr46/Yr29 in Saar. The powdery mildew resistance gene at the Lr34/Yr18 locus has recently been named Pm38. The powdery mildew resistance gene at the Lr46/Yr29 locus is designated as Pm39.

An ecotoxicoproteomic approach (SELDI-TOF mass spectrometry) to biomarker discovery in crab exposed to pollutants under laboratory conditions.

Ciphergen ProteinChip Technology is a proteomic tool, used for the discovery of new and sensitive biomarkers. This approach was used to evaluate the protein profile of crabs exposed to various pollutants. Two different exposure experiments were performed: spider crabs (Hyas araneus) were exposed for 3 weeks to diallyl phatalate (DAP), bisphenol A (BisA) and polybrominated diphenyl ether (PBDE-47), while shore crabs (Carcinus maeanas) were exposed to crude oil, crude oil spiked with alkylphenols (APs) and 4-nonylphenol (NP). Gender and species-related protein pattern alterations were observed and compared to controls. Results showed different responses to pollutants by the two species. Major disruption in protein peak expression was observed in samples exposed to mixtures of pollutants, i.e. oil spiked with APs. Compared to shore crab, spider crab species showed a lower degree of response in terms of number of altered protein peaks following exposure. In general, female individuals of both species showed a larger number of significantly altered proteins compared to males. Data analysis by non-metric multi-dimensional scaling (MDS) was performed. Bi-dimesional-MDS plots revealed a good separation of groups for both spider and shore crabs. In some cases, a good discrimination can also be observed between the two genders within each treatment. Results highlight the potential of crabs as sentinel organisms for the aquatic environment. The results indicate that SELDI-ToF technology is a powerful tool to discover protein expression signatures for different pollutants and sex dependent responses.

The potential of ecotoxicoproteomics in environmental monitoring: biomarker profiling in mussel plasma using ProteinChip array technology.

New global technologies, allowing simultaneous analysis of thousands of genes, proteins, and metabolites (so-called "omics" technologies), are being adopted rapidly by industry, academia, and regulatory agencies. This study evaluated the potential of proteomics in ecotoxicological research (i.e., ecotoxicoproteomics). Filter-feeding mussels (Mytilus edulis) were exposed continuously for 3 wk to oil, or oil spiked with alkylphenols and extra polycyclic aromatic hydrocarbons. The influence of chronic exposure on mussel plasma protein expression was investigated utilizing ProteinChip array technology in combination with surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI TOF MS). Results indicated that exposure to spiked oil had a more significant effect on protein expression in mussels than oil alone. In total, 83 mass peaks (intact or modified proteins/peptides) were significantly altered by spiked oil, while 49 were altered by oil. In exposed organisms, the majority of peaks were upregulated compared to controls (i.e., 69% in oil and 71% in spiked oil). Some peaks (32 in total) were affected by both treatments; however, the degree of response was higher in the spiked oil group for 25 of the 32 commonly affected features. Additionally, certain peaks revealed exposure- or gender-specific responses. Multivariate analysis with regression tree-based methods detected protein patterns associated with exposure that correctly classified masked samples with 90-95% accuracy. Similarly, 92% of females and 85% of males were correctly classified (independent of exposure). Results indicate that proteomics have the potential to make a valuable contribution to environmental monitoring and risk assessment.

Resistance to barley scald (Rhynchosporium secalis) in the Ethiopian donor lines 'Steudelli' and 'Jet', analyzed by partial least squares regression and interval mapping.

The resistance of barley (Hordeum vulgare L.) to Rhynchosporium secalis (scald) has been investigated in two crosses between the susceptible cv. 'Ingrid' and two resistant Ethiopian landraces, 'Steudelli' and 'Jet'. Doubled haploids were inoculated in replicated tests using two isolates of R. secalis, '4004' and 'WRS1872'. Expression of resistance differed widely between replicated tests. AFLP, SSR and RFLP markers were used to develop chromosome maps. Results have been analysed using partial least squares regression (PLSR) and interval mapping. In PLSR the major covariance structures or 'latent variables' between X (markers) and Y (isolates, tests) are modelled as principal components and their optimal number determined by cross-validation. In 'Steudelli' two QTL were detected, one on each of chromosomes 3H and 7H, in 4 out of 5 tests, while in 'Jet' only one (different) allele at the 3H locus was found. The validated R(2) varied between 11.0% and 64.9% in the replicated tests with '4004'.With isolate 'WRS1872' the 7H locus and another 3H locus were detected. By interval mapping the QTL detected were less stable and generally gave lower R(2) values than PLSR. PLSR does not depend on maps, but interval mapping based on values predicted by PLSR had R(2) around 90%. It is suggested that PLSR may be a useful tool in QTL analysis.

Resistance to Scald (Rhynchosporium secalis) in Barley (Hordeum vulgare) Studied by Near-Isogenic Lines: I. Markers and Differential Isolates.

ABSTRACT Near-isogenic lines (NILs) with resistance for scald in seventh generation backcross with 'Ingrid' as recurrent parent (RP) were tested with seven differential isolates of Rhynchosporium secalis in Norway and Canada. NILs of 'Turk', 'Brier', 'CI 8162', 'La Mesita', 'Hispont', 'Atlas 46', 'Modoc', 'Hudson', 'Abyssinian', 'Steudelli', and 'CI 2222' also were evaluated for field reactions. The genetic characterization of the NILs (degree of isogeneity with Ingrid) and with each other was carried out. The molecular marker pattern shows that the backcrossing program has resulted in from 86.3 to 100% RP genome in the NILs, depending on the marker system. On an average, 96% RP genome was found in the NILs. There were certain consistent (pairwise) differences between the NILs and RP on chromosomes 3H and 7H. Both chromosomes are known to contain loci conferring resistance to R. secalis, indicating successful introgression from the donors into the NILs. Approximately two-thirds of the observed RP-NIL polymorphisms were linked to the assumed resistance in the NIL. Based on the marker and phenotypic analyses of the NILs, suggestions for a more appropriate and updated terminology of genes for resistance to R. secalis in barley are made. The proposed changes in nomenclature also indicate the differentials that are available as NILs and those lacking.

[Ischemic stroke in children--a diagnostic challenge]. / Iskemiske hjerneslag hos barn--en diagnostisk utfordring.

BACKGROUND, MATERIAL AND METHODS: Ischaemic cerebral infarctions are relatively uncommon in childhood, and the aetiologies seen in this age group are different from those commonly seen in adults. This study presents clinical findings, investigation results and outcome in a five-year material collected between 1994 and 1999 in our department. It includes 22 children with ischaemic strokes aged three months to 13 year at the first or only stroke episode. RESULTS: The symptoms caused by ischaemic strokes in this age group vary and are often combined. Motor symptoms dominate, and we found hemiplegia, facial palsy, visual disturbances and reduced consciousness, listed according to decreasing occurrence. Infections and cardiac diseases or procedures were the most common aetiologies, both occurring with 22%. Other groups were autoimmune diseases (14%), malignancies (5%) and dissection of the a. carotis after trauma (5%). None of the patients in this material died as a result of the ischaemic stroke; 27% recovered completely. 41% had light sequela, 18% moderate sequela, and 14% ended up severely disabled. 18% had recurrent stroke episodes. INTERPRETATION: Appropriate examination after stroke in childhood is of great importance, since some of the aetiologies are associated with recurrence risk. Based on our clinical experiences and literature studies, we suggest a plan for diagnostic evaluation and treatment strategies for children who undergo an acute cerebral vascular disease.

Analysis of genetic diversity and structure in Ethiopian populations of Phytolacca dodecandra using RAPD.

The genetic diversity and structure in 17 wild populations (249 individuals) of Phytolacca dodecandra (endod) sampled along altitudinal gradients of 1600-3000 meters above sea level (m.a.s.l.) in Ethiopia was studied using random amplified polymorphic DNA (RAPD). A total of 70 polymorphic loci (P) scored from 12 RAPD primers were used to calculate different diversity indices within and between populations, habitats, geographical regions, climatic zones and altitude groups. The number of polymorphic loci and overall Shannon information measure (H) in the populations varied from 30 to 55 and from 0.228 to 0.418, respectively. In general, differences in population variability were found significantly correlated to effective population size. Both P and H were significantly higher in an undisturbed than in a disturbed habitat, and in the lowland and central-highland than in the highland altitude group. However, for both parameters the differences were not statistically significant between regions and climatic zones. Genetic distance between populations varied from 0.301 to 0.628. Cluster analysis performed using the genetic distance matrix revealed a clear separation of the highland populations (2501-3000 m.a.s.l.) from those of the lowland/central-highlands (1600-2500 m.a.s.l.) irrespective of their geographical regions and climatic zones. Analysis of molecular variance (AMOVA) indicated that differences in habitat, geographical regions and climatic zones explained 4.6%, 2.5% and 4.6%, respectively. But none of these differences were significant. Altitude explained 17.2% of the total variance and was highly significant. The data, therefore, clearly indicated the association of genetic structure in endod with altitude. The proportion of RAPD variation found among populations (21.2-35.0%) was somewhat intermediate between values reported for selfing and outcrossing species. The fixation index (FST) values (0.350 to 0.384) indicated very high genetic differentiation among populations.

Influence of medium and cold pretreatment on androgenetic response in Lolium perenne L.

Genotypes of Lolium perenne L. with different androgenetic responses were used to test effects of induction medium composition. The media tested were potato II (pII), 190-2, and modified Linsmaier and Skoog media, LS-1, LS-2, and LS-3. The effect of different gelling agents, activated charcoal in a 'double layer' design, and casein hydrolysate were also studied. From 36,696 anthers, 25,906 embryo-like structures, 1,959 albino and 173 green plants were generated. Significant differences were found between media, genotypes and medium-genotype interactions studied. All three media commonly used, pII, 190-2, and LS-3, were equivalent in production of green plants. Cold pretreatment of the anthers (4°C) significantly increased the number of embryo-like structures, the number and proportion of albino plants produced, but not the production of green plants.