An oral developmental neurotoxicity study of decabromodiphenyl ether (DecaBDE) in rats

BACKGROUND: Decabromodiphenyl ether (DecaBDE; CASRN 1163‐19‐5) is a flame retardant used in a variety of manufactured products. A single oral dose of 20.1 mg/kg administered to mice on postnatal day 3 has been reported to alter motor activity at 2, 4, and 6 months of age. METHODS: To further evaluate these results, a developmental neurotoxicity study was conducted in the most commonly used species for studies of this type, the rat, according to international validated testing guidelines and Good Laboratory Practice Standards. DecaBDE was administered orally via gavage in corn oil to dams from gestation day 6 to weaning at doses of 0, 1, 10, 100, or 1,000 mg/kg/day. Standard measures of growth, development, and neurological endpoints were evaluated in the offspring. Motor activity was assessed at 2 months of age. Additional motor activity assessments were conducted at 4 and 6 months of age. Neuropathology and morphometry evaluations of the offspring were performed at weaning and adulthood. RESULTS: No treatment‐related neurobehavioral changes were observed in detailed clinical observations, startle response, or learning and memory tests. No test substance‐related changes were noted in motor activity assessments performed at 2, 4, or 6 months of age. Finally, no treatment‐related neuropathological or morphometric alterations were found. CONCLUSIONS: Under the conditions of this study, the no‐observed‐adverse‐effect level for developmental neurotoxicity of DecaBDE was 1,000 mg/kg/day, the highest dose tested. Birth Defects Res (Part B) 92:17–35, 2011.© 2011 Wiley‐Liss, Inc.     

Bioinformatics and data-intensive scientific discovery in the beginning of the 21st century

This article is a summary of the bioinformatics issues and challenges of data-intensive science as discussed in the NSF-funded Data-Intensive Science (DIS) workshop in Seattle, September 19-20, 2010.     

Analysis of the expression of retinoic acid metabolising genes during Xenopus laevis organogenesis

Retinoic acid (RA) is a known teratogen that is also required endogenously for normal development of the embryo. RA can act as a morphogen, through direct binding to receptors and RA response elements in the genome, and classical studies of limb development and regeneration in amphibians have shown that it is likely to provide positional information. Availability of RA depends on both metabolic synthesis and catabolic degradation, and specific binding proteins act to further modulate the binding of RA to response elements. Here, we describe the expression of seven genes involved in metabolism (Raldh1-3), catabolism (Cyp26a and b) and binding of RA (Crabp1 and 2) during organogenesis in the clawed frog Xenopus laevis. Taken together, this data indicates regions of the embryo that could be affected by RA mediated patterning, and identifies some differences with other vertebrates.     

Advanced methods for the study of the chemistry and the metabolism of lichens

Lichens are compound entities of a fungal partner (“mycobiont”) and one or more photosynthetically active algae or cyanobacteria (“photobionts”). The organisms live in an intimate, symbiotic association which has been classified as a mutualistic or controlled parasitic relationship. Several metabolites from lichens display unique structures with unknown functions, and only a few model species have been analysed comprehensively. The complex metabolic interplay between the organisms in lichens is also incompletely understood. Earlier experiments with ¹⁴C-labelled precursors indicated that the photobionts produce from CO₂ glucose or sugar alcohols (e.g. ribitol and arabitol) which are then transferred to the mycobionts. In the fungi, these compounds are believed to be converted into mannitol serving as the carbon and energy source in the downstream metabolic processes. Recent methodological developments in spectroscopy and “systems biology” now enable a concise analysis of the metabolite profiles, networks and fluxes by non-targeted quantitative approaches. In this review, we summarize the current knowledge about lichen metabolism and report on the potential of the advanced methods to reinvestigate lichen chemistry and metabolism on a quantitative basis.     

Socio-economic status and z-score standardized height-for-age of U.S.-born children (ages 2–6)

This study explores socio-economic gradients in height (stature-for-age) among a nationally representative sample of 2–6 year old children in the United States. We use NHANES III (1988–1994) Youth data linked with a special Natality Data supplement which contains information from birth certificates among sampled NHANES III Youth who are <7 years of age. Our results indicate significant socio-economic gradients for both maternal education and family income, net of controls for confounders, including: birth weight, gestational age, family size, and parental heights. These results are in stark contrast to those from other developed countries that seem to indicate diminished or eliminated socio-economic disparities, net of known confounders. In the United States, it appears that socio-economic gradients have an effect on birth outcomes, and continue to have an additional direct and independent effect on height, even in early childhood.     

Trophic niche partitioning of cryptic species of long-eared bats in Switzerland: implications for conservation

Dietary niche partitioning is postulated to play a major role for the stable coexistence of species within a community, particularly among cryptic species. Molecular markers have recently revealed the existence of a new cryptic species of long-eared bat, Plecotus macrobullaris, in the European Alps. We studied trophic niches as well as seasonal and regional variations of diet in eight colonies of the three Plecotus species occurring in Switzerland. Faeces were collected monthly from individuals returning to roost after foraging. Twenty-one arthropod categories were recognized from the faeces. All three species fed predominantly on Lepidoptera, which made up 41%, 87% and 88% (means across colonies) of the diet composition of P. auritus, P. macrobullaris and P. austriacus, respectively. The occurrence of numerous fragments of both diurnal and flightless insects in the diet of P. auritus (but rarely in the diet of the other two species) indicates that this species mostly gleans prey from substrates. P. austriacus and P. macrobullaris are more typical aerial feeders. The latter two species have narrow trophic niches, whilst P. auritus has a much broader diet. Comparison of intraspecific and interspecific niche overlaps in P. auritus and P. macrobullaris in sympatry suggests dietary niche partitioning between these two species. In contrast, the high similarity of the trophic niches of P. austriacus and P. macrobullaris, associated with a typical parapatric distribution, indicates competitive exclusion. The best conservation measures are preservation and restoration of habitats offering a high abundance of moths, the major prey of the three Plecotus species.     

Regulation of cathepsin G reduces the activation of proinsulin-reactive T cells from type 1 diabetes patients

Autoantigenic peptides resulting from self-proteins such as proinsulin are important players in the development of type 1 diabetes mellitus (T1D). Self-proteins can be processed by cathepsins (Cats) within endocytic compartments and loaded to major histocompatibility complex (MHC) class II molecules for CD4(+) T cell inspection. However, the processing and presentation of proinsulin by antigen-presenting cells (APC) in humans is only partially understood. Here we demonstrate that the processing of proinsulin by B cell or myeloid dendritic cell (mDC1)-derived lysosomal cathepsins resulted in several proinsulin-derived intermediates. These intermediates were similar to those obtained using purified CatG and, to a lesser extent, CatD, S, and V in vitro. Some of these intermediates polarized T cell activation in peripheral blood mononuclear cells (PBMC) from T1D patients indicative for naturally processed T cell epitopes. Furthermore, CatG activity was found to be elevated in PBMC from T1D patients and abrogation of CatG activity resulted in functional inhibition of proinsulin-reactive T cells. Our data suggested the notion that CatG plays a critical role in proinsulin processing and is important in the activation process of diabetogenic T cells.     

Natural Selection and Material Culture

Natural selection is the basis of all evolutionary applications in biology as well as studies of cultural process in archaeology. Natural selection is important because it allows us the tools to talk not only about variation in biological systems but also material culture that are the by-products of the human decision-making processes. In this paper, we provide a baseline of the concept of natural selection and explanatory application in evolutionary archaeology.     

6th Annual European Antibody Congress 2010: November 29–December 1, 2010, Geneva,Switzerland

The 6^th European Antibody Congress (EAC), organized by Terrapinn Ltd., was held in Geneva, Switzerland, which was also the location of the 4^th and 5^th EAC.^1,2 As was the case in 2008 and 2009, the EAC was again the largest antibody congress held in Europe, drawing nearly 250 delegates in 2010. Numerous pharmaceutical and biopharmaceutical companies active in the field of therapeutic antibody development were represented, as were start-up and academic organizations and representatives from the US Food and Drug Administration (FDA). The global trends in antibody research and development were discussed, including success stories of recent marketing authorizations of golimumab (Simponi^®) and canakinumab (Ilaris^®) by Johnson & Johnson and Novartis, respectively, updates on antibodies in late clinical development (obinutuzumab/GA101, farletuzumab/MORAb-003 and itolizumab/T1 h, by Glycart/Roche, Morphotek and Biocon, respectively) and success rates for this fast-expanding class of therapeutics (Tufts Center for the Study of Drug Development). Case studies covering clinical progress of girentuximab (Wilex), evaluation of panobacumab (Kenta Biotech), characterization of therapeutic antibody candidates by protein microarrays (Protagen), antibody-drug conjugates (sanofi-aventis, ImmunoGen, Seattle Genetics, Wyeth/Pfizer), radio-immunoconjugates (Bayer Schering Pharma, Université de Nantes) and new scaffolds (Ablynx, AdAlta, Domantis/GlaxoSmithKline, Fresenius, Molecular Partners, Pieris, Scil Proteins, Pfizer, University of Zurich) were presented. Major antibody structural improvements were showcased, including the latest selection engineering of the best isotypes (Abbott, Pfizer, Pierre Fabre), hinge domain (Pierre Fabre), dual antibodies (Abbott), IgG-like bispecific antibodies (Biogen Idec), antibody epitope mapping case studies (Eli Lilly), insights in FcγRII receptor (University of Cambridge), as well as novel tools for antibody fragmentation (Genovis). Improvements of antibody druggability (Abbott, Bayer, Pierre Fabre, Merrimack, Pfizer), enhancing IgG pharmacokinetics (Abbott, Chugai), progress in manufacturing (Genmab, Icosagen Cell Factory, Lonza, Pierre Fabre) and the development of biosimilar antibodies (Biocon, Sandoz, Triskel) were also discussed. Last but not least, identification of monoclonal antibodies (mAbs) against new therapeutic targets (Genentech, Genmab, Imclone/Lilly, Vaccinex) including Notch, cMet, TGFβRII, SEMA4D, novel development in immunotherapy and prophylaxis against influenza (Crucell), anti-tumor activity of immunostimulatory antibodies (MedImmune/Astra Zeneca) and translations to clinical studies including immunogenicity issues (Amgen, Novartis, University of Debrecen) were presented.Key words: therapeutic antibodies, antibody-drug conjugates, protein scaffolds, biosimilars, bioproduction

• MAbs. 2011 Mar-Apr; 3(2): 111–132.
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• Day 1: November 29, 2010

2011 Mar-Apr; 3(2): 111–132. Published online 2011 Mar 1. doi: 10.4161/mabs.3.2.14788

Day 1: November 29, 2010

Alain Beck Copyright and License information DisclaimerCopyright notice The EAC chairman, Alain Beck (Centre d''Immunologie Pierre Fabre), opened the meeting with a presentation on strategies and challenges for the next generation of therapeutic antibodies.³ By analyzing the regulatory approvals of IgG-based biotherapeutic agents in the past ten years, we can gain insights into the successful strategies used by pharmaceutical companies so far to bring innovative drugs to the market. Strategies to optimize the structure of IgG antibodies and to design related or new structures with additional functions were presented. A detailed knowledge of antibody structure and activity now allows researchers to engineer primary antibodies on a more rational basis. Most approved antibodies are chimeric, humanized or human IgGs with similar constant domains. Numerous studies looking at the structure-function relationships of these antibodies have been published in the past five years with the aim of identifying antibody microvariants⁴ and investigating the influence of these variants on antigen binding, stability, pharmacokinetics (PK) and pharmacodynamics (PD). This knowledge is now being used to increase homogeneity and mitigate the chemistry, manufacture and control (CMC) liabilities of preclinical antibody candidates by genetic engineering. The removal by mutation of instability or aggregation hot spots in the antibody complementarity-determining regions (CDRs), and the use of hinge-stabilized or aglycosylated IgG4, are just a few examples of antibodies with improved pharmacological properties, including decreased heterogeneity, that are currently in development.Dr. Beck explained that the variable fragment (Fv) of an antibody is responsible for interactions with antigens and dictates essential properties such as binding affinity and target specificity. The origin of the Fv in therapeutic antibodies can be diverse, e.g., hybridomas, human antibody libraries, rodents with a human antibody repertoire or primatized or humanized antibodies from various species. Affinity maturation allows the binding affinity of the Fv to be improved or target selectivity to be modulated. The constant fragment (Fc) of an antibody is responsible for interactions with immune cells, and the associated properties of the Fc can also be modulated by engineering at several levels:⁵ altering the glycosylation status to regulate anti- and pro-inflammatory properties, modulating antibody-dependent cellular cytotoxicity (ADCC) by site-directed mutagenesis to alter binding to Fc receptors, increasing the serum half-life by Fc engineering to increase binding to the neonatal Fc receptor (FcRn), thereby preventing IgG degradation, and increasing complement activation by isotype chimerism. Additional functions can be endowed on antibodies by conjugation to other drugs. To date, the clinical success of antibody-drug conjugates (ADCs) has been limited. Nevertheless, promising new ADCs that include linkers with optimized properties (e.g., hydrolysable in the cytoplasm, resistant or susceptible to proteases or resistant to multi-drug resistance efflux pumps) and highly cytotoxic drugs are being studied in advanced clinical trials (e.g., trastuzumab emtansine, inotuzumab ozogamicin and brentuximab vedotin).⁶ IgGs have also been engineered to contain unique drug conjugation positions to obtain uniform and more homogeneous drug conjugates, such as ThioMab-drug conjugates, which have a uniform stoichiometry of approximately two coupled drugs per antibody molecule. Collectively, these advances should open new therapeutic avenues to deliver highly cytotoxic drugs with increased tolerability.