Workshop to identify critical windows of exposure for children's health: immune and respiratory systems work group summary.

Fetuses, infants, and juveniles (preadults) should not be considered simply "small adults" when it comes to toxicological risk. We present specific examples of developmental toxicants that are more toxic to children than to adults, focusing on effects on the immune and respiratory systems. We describe differences in both the pharmacokinetics of the developing immune and respiratory systems as well as changes in target organ sensitivities to toxicants. Differential windows of vulnerability during development are identified in the context of available animal models. We provide specific approaches to directly investigate differential windows of vulnerability. These approaches are based on fundamental developmental biology and the existence of discrete developmental processes within the immune and respiratory systems. The processes are likely to influence differential developmental susceptibility to toxicants, resulting in lifelong toxicological changes. We also provide a template for comparative research. Finally, we discuss the application of these data to risk assessment

Xenbase: a Xenopus biology and genomics resource

Xenbase (www.xenbase.org) is a model organism database integrating a diverse array of biological and genomic data on the frogs, Xenopus laevis and Xenopus (Silurana) tropicalis. Data is collected from other databases, high-throughput screens and the scientific literature and integrated into a number of database modules covering subjects such as community, literature, gene and genomic analysis. Gene pages are automatically assembled from data piped from the Entrez Gene, Gurdon Institute, JGI, Metazome, MGI, OMIM, PubMed, Unigene, Zfin, commercial suppliers and others. These data are then supplemented with in-house annotation. Xenbase has implemented the Gbrowse genome browser and also provides a BLAST service that allows users to specifically search either laevis or tropicalis DNA or protein targets. A table of Xenopus gene synonyms has been implemented and allows the genome, genes, publications and high-throughput gene expression data to be seamlessly integrated with other Xenopus data and to external database resources, making the wealth of developmental and functional data from the frog available to the broader research community

Cold Inactivation of l-Threonine Deaminase from Rhodospirillum rubrum

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66171/1/j.1432-1033.1971.tb01491.x.pd

Minimum information for reporting on the TEER (trans-epithelial/endothelial electrical resistance) assay (MIRTA)

© 2024 The Author(s). This is an open access article distributed under the Creative Commons Attribution License, to view a copy of the license, see: https://creativecommons.org/licenses/by/4.0/Standard information reporting helps to ensure that assay conditions and data are consistently reported and to facilitate inter-laboratory comparisons. Here, we present recommendations on minimum information for reporting on the TEER (trans-epithelial/endothelial electrical resistance) assay (MIRTA). The TEER assay is extensively used to evaluate the health of an epithelial/endothelial cell culture model and as an indicator of the potential toxicity of a test substance. This publication is the result of an international collaboration─called the RespTox (Respiratory Toxicity) Collaborative─through which twelve laboratories shared their protocols for assessing the barrier function of respiratory epithelial cells using the TEER assay following exposure to substances. The protocols from each laboratory were reviewed to identify general steps for performing the TEER assay, interlaboratory differences between steps, the rationale for differences, whether these differences impact results or cross-laboratory comparisons between TEER measurements. While the MIRTA recommendations are focused on respiratory epithelial cell systems, these recommendations can be adapted for other cell systems that form barriers. The use of these recommendations will support data transparency and reproducibility, reduce challenges in data interpretation, enable cross-laboratory comparisons, help assess study quality, and facilitate the incorporation of the TEER assay into national and international testing guidance.Peer reviewe

Pathway-based predictive approaches for non-animal assessment of acute inhalation toxicity

New approaches are needed to assess the effects of inhaled substances on human health. These approaches will be based on mechanisms of toxicity, an understanding of dosimetry, and the use of in silico modeling and in vitro test methods. In order to accelerate wider implementation of such approaches, development of adverse outcome pathways (AOPs) can help identify and address gaps in our understanding of relevant parameters for model input and mechanisms, and optimize non-animal approaches that can be used to investigate key events of toxicity. This paper describes the AOPs and the toolbox of in vitro and in silico models that can be used to assess the key events leading to toxicity following inhalation exposure. Because the optimal testing strategy will vary depending on the substance of interest, here we present a decision tree approach to identify an appropriate non-animal integrated testing strategy that incorporates consideration of a substance's physicochemical properties, relevant mechanisms of toxicity, and available in silico models and in vitro test methods. This decision tree can facilitate standardization of the testing approaches. Case study examples are presented to provide a basis for proof-of-concept testing to illustrate the utility of non-animal approaches to inform hazard identification and risk assessment of humans exposed to inhaled substances

X-ray powder diffraction data for BaPbO₃

Crystal and X-ray powder diffraction data are presented for BaPbO3. The powder pattern was indexed and refined on an orthorhombic cell with a=6.0264(3)Å , b=8.5078(3)Å , c=6.0629(2)Å, Z=4, space group Imma. The phase may actually be monoclinic with space group I2/m, but no distortion from the orthorhombic cell was evident in the powder patterns, suggesting a β angle very close to 90.0°.</jats:p