Critical period for a teratogenic VLA-4 antagonist: Developmental effects and comparison of embryo drug concentrations of teratogenic and non-teratogenic VLA-4 antagonists.

Background: Integrins such as VLA-4 (Very late antigen 4, integrin alpha4beta1) play key roles in cell-cell interactions that are critical for development. Homozygous null knockouts of the VLA-4 alpha4-subunit or VCAM-1 (VLA-4 cell surface ligand) in mice result in failure of the allantois and chorion to fuse leading to interrupted placentation and cardiac development and embryo lethality. Embryo-fetal studies of three VLA-4 antagonists, IVL745, IVL984, and HMR1031 [Crofts et al.

Different embryo-fetal toxicity effects for three VLA-4 antagonists.

Background: VLA-4 (Very late antigen 4, integrin alpha4beta1) plays an important role in cell-cell interactions that are critical for development. Homozygous null knockouts of the alpha4 subunit of VLA-4 or VCAM-1 (cell surface ligand to VLA-4) in mice result in abnormal placental and cardiac development and embryo lethality. Objectives of the current study were to assess and compare the teratogenic potential of three VLA-4 antagonists.

Harmonization of rat fetal external and visceral terminology and classification. Report of the Fourth Workshop on the Terminology in Developmental Toxicology, Berlin, 18-20 April 2002.

This article is a report on the Fourth Berlin Workshop on Terminology in Developmental Toxicology, which was held in April 2002. The workshop is part of an international project in the field of harmonization of terminology in developmental toxicology supported by IPCS. The goal of the Harmonization Project is to ensure better chemical risk assessment.

Future improvements and implementation of animal care practices within the animal testing regulatory environment.

Animal welfare is an increasingly important concern when considering biomedical experimentation. Many of the emerging regulations and guidelines specifically address animal welfare in laboratory animal care and use. The current revision of the appendix of the European Convention, ETS123 (Council of Europe), updates and improves on the current animal care standardization in Europe.