Linking Genes to Microbial Biogeochemical Cycling Lessons from Arsenic

The biotransformation of arsenic is highly relevant to the arsenic biogeochemical cycle. Identification of the molecular details of microbial pathways of arsenic biotransformation coupled with analyses of microbial communities by meta -omits can provide insights into detailed aspects of the complexities of this biocycle. Arsenic transformations couple to other biogeochemical cycles, and to the fate of both nutrients and other toxic environmental contaminants. Microbial redox metabolism of iron, carbon, sulfur, and nitrogen affects the redox and bioavailability of arsenic species. In this critical review we illustrate the biogeochemical processes and genes involved in arsenic biotransformations. We discuss how current and future metagenomie-, metatranscriptornic-, inetaproteomie-, arid inetabolothic-based methods will help to decipher individual microbial arsenic transformation processes, and their connections to other biogeochemical cycle. These insights will allow future use of microbial metabolic capabilities for biotechnological solutions to environmental problems. To understand the complex nature of inorganic and organic arsenic species and the fate of environmental arsenic will require integrating systematic approaches with biogeochemical modeling., Finally, from the lessons learned from these studies of arsenic biogeochemistry, we will be able to predict how the environment changes arsenic, and, in response, how arsenic biotransformations change the environment. [GRAPHICS

Assessment of possible environmental effects of space shuttle operations

The potential of shuttle operations to contribute to atmospheric pollution is investigated. Presented in this interim report are results of the study to date on rocket exhaust inventory, exhaust interactions, dispersion of the ground cloud, detection and measurement of hydrochloric acid and aluminum oxide, environmental effects of hydrochloric acid and aluminum oxide, stratospheric effects of shuttle effluents, and mesospheric and ionospheric effects of orbiter reentry. The results indicate space shuttle operation will not result in adverse environmental effects if appropriate launch constraints are met

Recent Advances in Molecular Toxicology of Cadmium and Nickel

Cadmium (Cd) and nickel (Ni) are two toxic elements which are widespread in the human environment, but less recognized as hazardous by the general public. Herein, we describe molecular mechanisms of their toxicity towards humans, in the context of general chemical and toxicological properties of these metals. Following the introductory remarks, the routes of exposure are outlined. The next chapter covers the health hazards posed by cadmium and nickel with the main stress placed on diseases like cadmium induced nephropathy, reproductive disorders due to cadmium exposure, cadmium related COPD and cadmium carcinogenesis. In respect to nickel, acute toxicity, nickel allergy and nickel carcinogenicity were described. This overall description provides the basis for a detailed account of molecular mechanisms of cadmium and nickel toxicity. They include the involvement of metallothioneins and their role in the transport of Cd(II) ions, and the role of oxidative damage and DNA repair inhibition in cadmium carcinogenesis. The final issue covered in respect to molecular mechanisms of cadmium toxicity is its influence on cellular junctions. Molecular mechanisms of nickel toxicity are divided into subjects of nickel allergy and several mechanisms related to its carcinogenicity. The discussion is completed by the presentation of nickel and cadmium interactions with zinc fingers as a possible common ground of their molecular toxicity

Health impact of nanotechnologies in food production

Geen RIVM rapportnummer in publicatieInventory study on the current use of nanotechnology in food products and advise on the most relevant safety evaluation issues. This report describes the results of this study. The report is set up in two parts. First you will find an aggregation of the results in the answer to 10 questions. In this part you will also find our suggestions for prioritizing the research that is needed. The second document is a scientific background document

Cyclin B1/CDK1-regulated mitochondrial bioenergetics in cell cycle progression and tumor resistance.

A mammalian cell houses two genomes located separately in the nucleus and mitochondria. During evolution, communications and adaptations between these two genomes occur extensively to achieve and sustain homeostasis for cellular functions and regeneration. Mitochondria provide the major cellular energy and contribute to gene regulation in the nucleus, whereas more than 98% of mitochondrial proteins are encoded by the nuclear genome. Such two-way signaling traffic presents an orchestrated dynamic between energy metabolism and consumption in cells. Recent reports have elucidated the way how mitochondrial bioenergetics synchronizes with the energy consumption for cell cycle progression mediated by cyclin B1/CDK1 as the communicator. This review is to recapitulate cyclin B1/CDK1 mediated mitochondrial activities in cell cycle progression and stress response as well as its potential link to reprogram energy metabolism in tumor adaptive resistance. Cyclin B1/CDK1-mediated mitochondrial bioenergetics is applied as an example to show how mitochondria could timely sense the cellular fuel demand and then coordinate ATP output. Such nucleus-mitochondria oscillation may play key roles in the flexible bioenergetics required for tumor cell survival and compromising the efficacy of anti-cancer therapy. Further deciphering the cyclin B1/CDK1-controlled mitochondrial metabolism may invent effect targets to treat resistant cancers