Negative air ions as a source of superoxide

The physico-chemical characteristics and possible formation mechanisms of negative air ions are considered. It was found that the products of oxygen and nitrogen negative ionization reduce ferricytochromec and nitroblue tetrazolium, and that these reactions were inhibited by superoxide dismutase. The interaction of negatively ionized oxygen with water led to hydrogen peroxide accumulation, which was inhibited by tetranitromethane or catalase. Nitrogen ionization under these conditions caused the formation of the hydrated electron e _aq ^— and the superoxide anion O ₂ ^— . The data obtained indicate that the biological activity of negative air ions may be dependent on superoxide. The generation of reactive oxygen ions in the gas phase and also at a gas/water interface is described. A scheme for superoxide production under oxygen and nitrogen ionization is proposed.     

Variability in host plant resistance of Sorghum to Striga Hermonthica infestation in West Africa

Fourteen elite sorghum lines were evaluated for their resistance to Striga hermonthica at three locations in Nigeria and Mali. Results showed that many of the lines especially MALISOR 84-1, SAMSORG 41, 97-SB-F5DT-64 (Keninkédié) and the check SRN 39 remained resistant to Striga in all locations with low emerged Striga counts, while SAMSORG 14 had the highest Striga infestation in all locations. Considerable variation in reaction to Striga infestation was observed on Séguètana, 97-SB-F5DT-63 (Wasa), 97-SB-F5DT-65, CMDT 38, CMDT 39 and CMDT 45 which were susceptible to Striga at Samaru, Nigeria but were resistant to Striga at both locations in Mali. Based on low Striga resistance and high grain yield, lines MALISOR 84-1, SAMSORG 41, 97-SB-F5DT-64, 97-SB-F5DT-65, CMDT 39 and SAMSORT 14 have been nominated for wider evaluation across more West African countries.     

Quantitative Ultrasound Spectroscopic Imaging for Characterization of Disease Extent in Prostate Cancer Patients

Three-dimensional quantitative ultrasound spectroscopic imaging of prostate was investigated clinically for the noninvasive detection and extent characterization of disease in cancer patients and compared to whole-mount, whole-gland histopathology of radical prostatectomy specimens. Fifteen patients with prostate cancer underwent a volumetric transrectal ultrasound scan before radical prostatectomy. Conventional-frequency (~ 5 MHz) ultrasound images and radiofrequency data were collected from patients. Normalized power spectra were used as the basis of quantitative ultrasound spectroscopy. Specifically, color-coded parametric maps of 0-MHz intercept, midband fit, and spectral slope were computed and used to characterize prostate tissue in ultrasound images. Areas of cancer were identified in whole-mount histopathology specimens, and disease extent was correlated to that estimated from quantitative ultrasound parametric images. Midband fit and 0-MHz intercept parameters were found to be best associated with the presence of disease as located on histopathology whole-mount sections. Obtained results indicated a correlation between disease extent estimated noninvasively based on midband fit parametric images and that identified histopathologically on prostatectomy specimens, with an r² value of 0.71 (P < .0001). The 0-MHz intercept parameter demonstrated a lower level of correlation with histopathology. Spectral slope parametric maps offered no discrimination of disease. Multiple regression analysis produced a hybrid disease characterization model (r² = 0.764, P < .05), implying that the midband fit biomarker had the greatest correlation with the histopathologic extent of disease. This work demonstrates that quantitative ultrasound spectroscopic imaging can be used for detecting prostate cancer and characterizing disease extent noninvasively, with corresponding gross three-dimensional histopathologic correlation.     

Two common nonsynonymous paraoxonase 1 (<Emphasis Type="Italic">PON1</Emphasis>) gene polymorphisms and brain astrocytoma and meningioma

Background  

Human serum paraoxonase 1 (PON1) plays a major role in the metabolism of several organophosphorus compounds. The enzyme is encoded by the polymorphic gene PON1, located on chromosome 7q21.3. Aiming to identify genetic variations related to the risk of developing brain tumors, we investigated the putative association between common nonsynonymous PON1 polymorphisms and the risk of developing astrocytoma and meningioma.     

Long-term effects of graduated compression stockings on cardiorespiratory performance

The use of graduated compression stockings (GCS) in sport has been increasing in the last years due to their potential positive effects for athletes. However, there is little evidence to support whether these types of garments actually improve cardiorespiratory performance. The aim of this study was to examine the cardiorespiratory responses of GCS during running after three weeks of regular use. Twenty recreational runners performed three tests on different days: test 1) – a 5-min maximal effort run in order to determine the participants’ maximal aerobic speed; and tests 2) and 3) – a fatigue running test of 30 minutes at 80% of their maximal aerobic speed with either GCS or PLACEBO stockings at random. Cardiorespiratory parameters (minute ventilation, heart rate, relative oxygen consumption, relative carbon dioxide production, ventilatory equivalents for oxygen and carbon dioxide, and oxygen pulse) were measured. Before each test in the laboratory, the participants trained with the randomly assigned stockings (GCS or PLACEBO) for three weeks. No significant differences between GCS and PLACEBO were found in any of the cardiorespiratory parameters. In conclusion, the present study provides evidence that running with GCS for three weeks does not influence cardiorespiratory parameters in recreational runners.     

Is a robust phylogeny of the enterobacterial plant pathogens attainable?

Sequences from gapA, gyrA and ompA were used to evaluate the relationships of the enterobacterial plant pathogens, and assess whether a robust phylogeny can be ascertained using this group of housekeeping genes. Up to 48 taxa were included in a combined phylogenetic analysis to explore the evolutionary distribution of plant pathogenic species across the family Enterobacteriaceae. Phylogenies were reconstructed from gapA, gyrA and ompA gene sequences using maximum parsimony and maximum likelihood algorithms, and phylogenetic congruence was evaluated by the incongruence length difference test and the partition addition bootstrap alteration approach. The resulting gene trees were found to be incongruent, with gapA supporting a monophyletic origin for the plant pathogenic species. In contrast, gyrA and ompA supported multiple polyphyletic origins of Erwinia, Brenneria, Pectobacterium and Pantoea in conjunction with a previously published 16S rDNA phylogeny. However, none of the trees (not even the published 16S rDNA gene tree) supports the current taxonomic classification of these genera into four clades, with Pantoea forming the only monophyletic group in the gapA, gyrA and 16S rDNA trees. Finally, the gapA, gyrA and previously published 16S rDNA phylogenies differ in the taxonomic placement of several bacterial strains which are separated in the three trees. The observed incongruence among the four gene histories is likely to be the result of horizontal transfer events, confounding the search for a robust set of housekeeping genes with a shared evolutionary history that could be used to confidently characterize the relationships of the plant pathogenic enterobacteria. © The Willi Hennig Society 2010.     

Non-secretory exocytoses in the brain.

Regulated exocytosis, the process by which the membrane of specific cytoplasmic organelles fuse with the plasma membrane in response to adequate stimulation, is most often considered to serve only for the discharge of secretory products, in the brain especially neurotransmitters and peptides. Growing evidence demonstrates however that non-secretory exocytoses, aimed at the insertion at the cell surface of the organelle membrane, are of great physiological importance and may also have critical roles in specific diseases. Recently, two groups of non-secretory exocytoses have been identified: those aimed at the transfer to the cell surface of specific proteins, that we have proposed to be called the protein-exposing exocytoses; and those aimed at the enlargement of the surface itself, the expansive exocytoses. Here we present the existing knowledge about three types of non-secretory exocytoses that occur in the brain: the protein-exposing exocytoses that transfer ionic receptors to the postsynaptic membrane, the best known example being that of the glutamatergic AMPA receptor, a main actor of synaptic plasticity; the expansive exocytosis necessary for the growth of nerve fibres; and the rapid exocytosis of enlargeosomes, that can induce considerable expansion of the cell surface area in a variety of cells types, including the astrocytes.     

Assessment of radiation exposure of murine rodents at the EURT territories

The study provides data on contemporary levels of radiation exposure of organs and tissues of murine rodents (several species of mice and voles) inhabiting the East-Ural Radioactive Trace. The estimation procedure involves the most advanced approach based on application of appropriate voxel phantom and biokinetic model. Input data for dose assessment are the results of measurements of skeletal ⁹⁰Sr activity concentration. Maximal internal dose to skeleton, accumulated during 45 days, is 303 mGy. Median internal dose rates on the last day before trapping were 0.83, 0.092 and 0.023 mGy/day for animals trapped at the sites with initial (1957) ⁹⁰Sr surface contamination >37 MBq/m², 18.5–37 MBq/m² and 0.074–18.5 MBq/m² respectively. Taking to account internal and external exposures, upper boundary of the ICRP Derived Consideration Reference Level (DCRL) is exceeded on the territory with maximal level of the initial ⁹⁰Sr surface contamination. On the territory with 18.5–37 MBq/m², whole body mean dose rates to murine rodents exceed the lower boundary of DCRL. On the areas with lower level of surface contamination, even the 90-th percentile of dose rate is below the DCRL.