Metabolism of mevalonic acid to phosphorylated intermediates in a cell-free extract from Nepeta cataria leaves

A cell-free extract has been prepared from leaves of Nepeta cataria plants which converts mevalonic acid (MVA) to mevalonic acid phosphate (MVAP), mevalonic acid pyrophosphate (MVAPP) and isopentenylpyrophosphate (IPP). These enzymes are found in the 30 000 g supernatant. The activities are maximal at pH 7 and the formation of mevalonic acid pyrophosphate and isopentenyl-pyrophosphate reaches a maximal level after an incubation time of 180 min whereas the level of mevalonic acid phosphate begins to decrease after 90 min.     

Newly Discovered Ebola Virus Associated with Hemorrhagic Fever Outbreak in Uganda

Over the past 30 years, Zaire and Sudan ebolaviruses have been responsible for large hemorrhagic fever (HF) outbreaks with case fatalities ranging from 53% to 90%, while a third species, Côte d''Ivoire ebolavirus, caused a single non-fatal HF case. In November 2007, HF cases were reported in Bundibugyo District, Western Uganda. Laboratory investigation of the initial 29 suspect-case blood specimens by classic methods (antigen capture, IgM and IgG ELISA) and a recently developed random-primed pyrosequencing approach quickly identified this to be an Ebola HF outbreak associated with a newly discovered ebolavirus species (Bundibugyo ebolavirus) distantly related to the Côte d''Ivoire ebolavirus found in western Africa. Due to the sequence divergence of this new virus relative to all previously recognized ebolaviruses, these findings have important implications for design of future diagnostic assays to monitor Ebola HF disease in humans and animals, and ongoing efforts to develop effective antivirals and vaccines.     

Pulmonary injury after combined exposures to low-dose low-LET radiation and fungal spores

Exposure to infectious microbes is a likely confounder after a nuclear terrorism event. In combination with radiation, morbidity and mortality from an infection may increase significantly. Pulmonary damage after low-dose low-LET irradiation is characterized by an initial diffuse alveolar inflammation. By contrast, inhaled fungal spores produce localized damage around pulmonary bronchioles. In the present study, we assessed lung injury in C57BL/6 mice after combined exposures to whole-body X radiation and inhaled fungal spores. Either animals were exposed to Aspergillus spores and immediately irradiated with 2 Gy, or the inoculation and irradiation were separated by 8 weeks. Pulmonary injury was assessed at 24 and 48 h and 1, 2, 4, 8, and 24 weeks later using standard H&E-stained sections and compared with sham-treated age-matched controls. Immunohistochemistry for invasive inflammatory cells (macrophages, neutrophils and B and T lymphocytes) was performed. A semi-quantitative assessment of pulmonary injury was made using three distinct parameters: local infiltration of inflammatory cells, diffuse inflammation, and thickening and distortion of alveolar architecture. Radiation-induced changes in lung architecture were most evident during the first 2 weeks postexposure. Fungal changes were seen over the first 4 weeks. Simultaneous combined exposures significantly increased the duration of acute pulmonary damage up to 24 weeks (P < 0.01). In contrast, administration of the fungus 8 weeks after irradiation did not produce enhanced levels of acute pulmonary damage. These data imply that the inhalation of fungal spores at the time of a radiation exposure alters the susceptibility of the lungs to radiation-induced injury.     

A GROWTH ADVANTAGE FOR MICROCYSTIN PRODUCTION BY MICROCYSTIS PCC7806 UNDER HIGH LIGHT1

Batch cultures of both Microcystis PCC7806 and a mcyA^? knockout mutant (MT) of PCC7806 were cultured at three different light intensities and five media treatments, so as to vary cellular N:C ratios and concentrations and sampled daily over 5 d for analysis of microcystin concentration, cell numbers, and residual nitrate in the growth medium. A competitive survival advantage was noted at a high‐light level (37 μmol photons · m^?2 · s^?1), where the toxic strain survived while the nontoxic strain became chlorotic. A strong correlation (r² = 0.91, P < 0.001, N = 22) between microcystin concentration and growth rate was observed at high‐light conditions. No advantage was observed at optimal or low‐light conditions, and media composition had no significant effect on the relationship between toxicity and survival at high‐light conditions. These data suggest a possible role for microcystin in protection against photooxidation.