Patterned femtosecond-laser ablation of Xenopus laevis melanocytes for studies of cell migration, wound repair, and developmental processes

Ultrafast (femtosecond) lasers have become an important tool to investigate biological phenomena because of their ability to effect highly localized tissue removal in surgical applications. Here we describe programmable, microscale, femtosecond-laser ablation of melanocytes found on Xenopus laevis tadpoles, a technique that is applicable to biological studies in development, regeneration, and cancer research. We illustrate laser marking of individual melanocytes, and the drawing of patterns on melanocyte clusters to help track their migration and/or regeneration. We also demonstrate that this system can upgrade scratch tests, a technique used widely with cultured cells to study cell migration and wound healing, to the more realistic in vivo realm, by clearing a region of melanocytes and monitoring their return over time. In addition, we show how melanocyte ablation can be used for loss-of-function experiments by damaging neighboring tissue, using the example of abnormal tail regeneration following localized spinal cord damage. Since the size, shape, and depth of melanocytes vary as a function of tadpole age and melanocyte location (head or tail), an ablation threshold chart is given. Mechanisms of laser ablation are also discussed

Control of sulphide during anaerobic treatment of S-containing wastewaters by adding limited amounts of oxygen or nitrate

Sulphide generated during anaerobic treatment of S-containing wastewaters represents an environmental problem. Adding limited amounts of oxygen or nitrate (or nitrite) to biologically (or chemically) oxidise sulphide forms a simple process level strategy to control this problem. This short review evaluates the feasibility and limitations of this strategy on the basis of the results of bioreactor studies.Sulphide generated during anaerobic treatment of S-containing wastewaters represents an environmental problem. Adding limited amounts of oxygen or nitrate (or nitrite) to biologically (or chemically) oxidise sulphide forms a simple process level strategy to control this problem. This short review evaluates the feasibility and limitations of this strategy on the basis of the results of bioreactor studies.Spanish Ministry of Education and Science; AEA Technology Environment; Nova Energie; The Swedish Gas Centre; University of Southern Denmark

Early Gnathostome Phylogeny Revisited: Multiple Method Consensus

This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.A series of recent studies recovered consistent phylogenetic scenarios of jawed vertebrates, such as the paraphyly of placoderms with respect to crown gnathostomes, and antiarchs as the sister group of all other jawed vertebrates. However, some of the hylogenetic relationships within the group have remained controversial, such as the positions of Entelognathus, ptyctodontids, and the Guiyu-lineage that comprises Guiyu, Psarolepis and Achoania. The revision of the dataset in a recent study reveals a modified phylogenetic hypothesis, which shows that some of these phylogenetic conflicts were sourced from a few inadvertent miscodings. The interrelationships of early gnathostomes are addressed based on a combined new dataset with 103 taxa and 335 characters, which is the most comprehensive morphological dataset constructed to date. This dataset is investigated in a phylogenetic context using maximum parsimony (MP), Bayesian inference (BI) and maximum likelihood (ML) approaches in an attempt to explore the consensus and incongruence between the hypotheses of early gnathostome interrelationships recovered from different methods. Our findings consistently corroborate the paraphyly of placoderms, all `acanthodians' as a paraphyletic stem group of chondrichthyans, Entelognathus as a stem gnathostome, and the Guiyu-lineage as stem sarcopterygians. The incongruence using different methods is less significant than the consensus, and mainly relates to the positions of the placoderm Wuttagoonaspis, the stem chondrichthyan Ramirosuarezia, and the stem osteichthyan LophosteusÐthe taxa that are either poorly known or highly specialized in character complement. Given that the different performances of each phylogenetic approach, our study provides an empirical case that the multiple phylogenetic analyses of morphological data are mutually complementary rather than redundant

Resolvins suppress tumor growth and enhance cancer therapy

National Cancer Institute grants RO1 01CA170549-02 (to D. Panigrahy and C.N. Serhan), ROCA148633-01A4 (to D. Panigrahy), and GM095467 (to C.N. Serhan); the Stop and Shop Pediatric Brain Tumor Fund (to M.W. Kieran); the CJ Buckley Pediatric Brain Tumor Fund (to M.W. Kieran); Alex Lemonade Stand (to M.W. Kieran); Molly’s Magic Wand for Pediatric Brain Tumors (to M.W. Kieran); the Markoff Foundation Art-In-Giving Foundation (to M.W. Kieran); the Kamen Foundation (to M.W. Kieran); Jared Branfman Sunflowers for Life (to M.W.K.); and The Wellcome Trust program 086867/Z/08 (to M. Perretti)

ALDH2 mediates 5-nitrofuran activity in multiple species

Understanding how drugs work in vivo is critical for drug design and for maximizing the potential of currently available drugs. 5-nitrofurans are a class of pro-drugs widely used to treat bacterial and trypanosome infections, but despite relative specificity 5-nitrofurans often cause serious toxic side-effects in people. Here, we use yeast, zebrafish and human in vitro systems to assess the biological activity of 5-nitrofurans, and identify a conserved interaction between aldehyde dehydrogenase (ALDH) 2 and 5-nitrofurans across these species. In addition, we show that the activity of nifurtimox, a 5-nitrofuran anti-trypanosome pro-drug, is dependent on zebrafish Aldh2 and that nifurtimox is a substrate for human ALDH2. This study reveals a conserved and biologically relevant ALDH2-5-nitrofuran interaction that may have important implications for managing the toxicity of 5nitrofuran treatment.PostprintPeer reviewe

A metaproteomic approach gives functional insights into anaerobic digestion

<br>Aims:  The objective of this work was to provide functional evidence of key metabolic pathways important for anaerobic digestion processes through the identification of highly expressed proteins in a mixed anaerobic microbial consortium.</br> <br>Methods and Results:  The microbial communities from an anaerobic industrial-like wastewater treatment bioreactor were characterized using phylogenetic analyses and metaproteomics. Clone libraries indicated that the bacterial community in the bioreactor was diverse while the archaeal population was mainly composed of Methanocorpusculum-like (76%) micro-organisms. Three hundred and eighty-eight reproducible protein spots were obtained on 2-D gels, of which 70 were excised and 33 were identified. The putative functions of the proteins detected in the anaerobic bioreactor were related to cellular processes, including methanogenesis from CO2 and acetate, glycolysis and the pentose phosphate pathway. Metaproteomics also indicated, by protein assignment, the presence of specific micro-organisms in the bioreactor. However, only a limited overlap was observed between the phylogenetic and metaproteomic analyses.</br> <br>Conclusions:  This study provides some direct evidence of the microbial activities taking place during anaerobic digestion.</br&gt