Co-detection of azoxystrobin and thiabendazole fungicides in mold and mildew resistant wallboards and in children.

The study measured the levels of azoxystrobin (AZ) and thiabendazole (TBZ) in wallboards and metabolite levels of these fungicides in children. The paper covering of wallboard samples contained a higher concentration of AZ and TBZ than the gypsum core, and similar amounts (w/w) of these two fungicides were present in the samples. These data suggest that commercial products containing a 1:1 (w/w) amount of AZ and TBZ, such as Sporgard® WB or Azo Tech™, were applied to the wallboard paper. This is the first detection of TBZ in mold-and-mildew resistant wallboards. The TBZ metabolite, 5OH-TBZ, was detected in 48% of urine samples collected from children aged 40-84 months, and was co-detected with AZ-acid, a common AZ metabolite, in 37.5% of the urine samples. The detection frequency of 5OH-TBZ was positively associated with the detection frequency of AZ-acid. These findings suggest that certain types of wallboards used in homes and commercial buildings may be a potential source of co-exposure to AZ and TBZ in humans.

The amazing and anomalous axolotls as scientific models.

Ambystoma mexicanum (axolotl) embryos and juveniles have been used as model organisms for developmental and regenerative research for many years. This neotenic aquatic species maintains the unique capability to regenerate most, if not all, of its tissues well into adulthood. With large externally developing embryos, axolotls were one of the original model species for developmental biology. However, increased access to, and use of, organisms with sequenced and annotated genomes, such as Xenopus laevis and tropicalis and Danio rerio, reduced the prevalence of axolotls as models in embryogenesis studies. Recent sequencing of the large axolotl genome opens up new possibilities for defining the recipes that drive the formation and regeneration of tissues like the limbs and spinal cord. However, to decode the large A. mexicanum genome will take a herculean effort, community resources, and the development of novel techniques. Here, we provide an updated axolotl-staging chart ranging from one-cell stage to immature adult, paired with a perspective on both historical and current axolotl research that spans from their use in early studies of development to the recent cutting-edge research, employment of transgenesis, high-resolution imaging, and study of mechanisms deployed in regeneration.