Isomeric lipid signatures reveal compartmentalized fatty acid metabolism in cancer

The cellular energy and biomass demands of cancer drive a complex dynamic between uptake of extracellular FAs and their de novo synthesis. Given that oxidation of de novo synthesized FAs for energy would result in net-energy loss, there is an implication that FAs from these two sources must have distinct metabolic fates; however, hitherto, all FAs have been considered part of a common pool. To probe potential metabolic partitioning of cellular FAs, cancer cells were supplemented with stable isotope-labeled FAs. Structural analysis of the resulting glycerophospholipids revealed that labeled FAs from uptake were largely incorporated to canonical (sn-) positions on the glycerol backbone. Surprisingly, labeled FA uptake also disrupted canonical isomer patterns of the unlabeled lipidome and induced repartitioning of n-3 and n-6 PUFAs into glycerophospholipid classes. These structural changes support the existence of differences in the metabolic fates of FAs derived from uptake or de novo sources and demonstrate unique signaling and remodeling behaviors usually hidden from conventional lipidomics.     

Functional response of Fucus vesiculosus communities to tributyltin measured in an in situ continuous flow-through system

The effects of antifouling paint leachate containing tributyltin on community metabolism and nutrient dynamics were measured in situ on natural communities dominated by Fucus vesiculosus. The measurements were made in two areas with different salinities and at various TBT concentrations up to about 5 µg 1^–1. A portable continuous flow-through system was used in which the communities were incubated for a week. Continual measurements of oxygen, temperature, light and flow rate of water were made. A Perturbation Index (PI) and an Absolute Disturbance Index (ADI) were used to describe the changes due to treatment relative to the control, and to obtain a total picture of disturbance using all measured parameters. Photosynthesis was particularly strongly affected and changes were obvious in oxygen production and nutrient uptake at TBT levels as low as 0.6 µg 1–1.     

Bird carcass detection from integrated trials at multiple wind farms

It is often necessary to estimate the number of wind turbine collision fatalities to assess impacts to birds following construction of wind farms. Detection of bird carcasses at wind turbines in the field is affected by carcass persistence and searcher detection rate. Integrated detection trials, which integrate carcass persistence and searcher detection trials into the periodic fatality search, have been proposed as an effective method for estimating these parameters. The purpose of our study was to test whether and how environmental factors affect integrated detection trial outcomes at multiple wind farms. We conducted this study at 10 wind farms in various environments of Japan. Binary data on trial outcomes in open versus forested areas served as our response variable in a generalized additive mixed model informed by days into trial, carcass body mass, season, whether snow covered the ground, and precipitation. For both ground cover types, days into trial and body mass were included in all the top models, suggesting that these factors most influenced bird carcass detection probability in integrated trials. The best model in open areas included days into trial, body mass, snow, and precipitation, and the best model in forested areas included days into trial, body mass, snow, precipitation, and season. Values of area under the curve indicated high accuracy of the best model for both ground cover types. The survey design needs to be appropriate to the size of the target species and to the environment in which the impacts will occur, such as the site's seasonality, its ground cover, and whether snow will cover the ground. Frequency of post-construction fatality monitoring should also be set cautiously, especially at wind farms located on small-bird migration routes, at wind farms in open areas, in areas with snow-covered ground in winter, or in forested areas during spring and summer because detection probabilities decline fastest under such conditions.     

Assessment of environmental contamination associated with a mammalian cell transformation assay

Summary To estimate worker exposures to, and environmental contamination from, test chemicals and organic solvents used in an in vitro assay to assess the carcinogenic potential of chemicals, sodium fluorescein, a noncarcinogenic fluorescent material, was dissolved in tissue culture medium used to maintain early passage hamster embryo cells. Personal and environmental samples were taken over a 14-d period. The assay was performed according to standard procedures in a ventilated glove box or laminar flow safety cabinet. Considerably more than 99% of the chemical contamination found was recovered from the interiors of the glove box and hood and from disposable equipment. Contamination outside the containment units (less than 1 μg) resulted from intralaboratory transport of chemicals, treated cultures, and contaminated equipment. We conclude that the standard operating practices and procedures provided adequate safeguards for personnel and the environment. Research sponsored by the National Cancer Institute under Contract N01-CO-75380, with Litton Bionetics, Inc.     

Estimating ecotoxicological risk and impact using indigenous aquatic microbial communities

Emphasis has increased on accuracy in predicting the effect that anthropogenic stress has on natural ecosystems. Although toxicity tests low in environmental realism, such as standardized single species procedures, have been useful in providing a certain degree of protection to human health and the environment, the accuracy of such tests for predicting the effects of anthropogenic activities on complex ecosystems is questionable. The use of indigenous communities of microorganisms to assess the hazard of toxicants in aquatic ecosystems has many advantages. Theoretical and practical aspects of microbial community tests are discussed, particularly in related to widely cited problems in the use of multispecies test systems for predicting hazard. Further standardization of testing protocols using microbial colonization dynamics is advocated on the basis of previous studies, which have shown these parameters to be useful in assessing risk and impact of hazardous substances in aquatic ecosystems.     

10种杀菌剂对中华蜜蜂的急性毒性测定及风险评估

明确80%代森锰锌可湿性粉剂、50%啶酰菌胺水分散型粒剂、50%腐霉利可湿性粉剂、50%烯酰吗啉可湿性粉剂、100 g/L氰霜唑悬浮剂、20%叶枯唑可湿性粉剂、2%春雷毒素水剂、12.50%腈菌唑乳油、25%丙环唑乳油和15%咪鲜胺微乳剂等10种杀菌剂对中华蜜蜂Apis cerana cerana工蜂的急性毒性,并评价其对中华蜜蜂工蜂的风险性。在室内采用摄入法和点滴法测定10种杀菌剂对中华蜜蜂工蜂的急性经口和接触毒性。结果表明代森锰锌,啶酰菌胺,腐霉利等7种杀菌剂对中华蜜蜂的急性毒性均为低毒;腈菌唑和丙环唑对中华蜜蜂的急性经口毒性和急性接触毒性均为中毒,咪鲜胺对中华蜜蜂的急性经口毒性为高毒,急性接触毒性为中毒;这3种杀菌剂且均属于中等风险性。建议禁止咪鲜胺在蜜源作物开花授粉期施用,慎重选择中等毒性杀菌剂腈菌唑和丙环唑,尽量选择对蜜蜂低毒的杀菌剂,以保护中华蜜蜂的安全。