A Method to Reuse Archived H&E Stained Histology Slides for a Multiplex Protein Biomarker Analysis.

Archived Hematoxylin and Eosin (H&E) stained pathology slides are routinely stored to index formalin-fixed paraffin-embedded (FFPE) sample tissue blocks. FFPE blocks are clinically annotated human tumor specimens that can be valuable in studies decades after the tissue is collected. If stored properly, they have the potential to yield a valuable number of serial sectioned slides for diagnostic or research purposes.

Fate tracing reveals the endothelial origin of hematopoietic stem cells.

Hematopoietic stem cells (HSCs) originate within the aortic-gonado-mesonephros (AGM) region of the midgestation embryo, but the cell type responsible for their emergence is unknown since critical hematopoietic factors are expressed in both the AGM endothelium and its underlying mesenchyme. Here we employ a temporally restricted genetic tracing strategy to selectively label the endothelium, and separately its underlying mesenchyme, during AGM development. Lineage tracing endothelium, via an inducible VE-cadherin Cre line, reveals that the endothelium is capable of HSC emergence.

Platelet-derived growth factor receptors direct vascular development independent of vascular smooth muscle cell function.

Complete loss of platelet-derived growth factor (PDGF) receptor signaling results in embryonic lethality around embryonic day 9.5, but the cause of this lethality has not been identified. Because cardiovascular failure often results in embryonic lethality at this time point, we hypothesized that a failure in cardiovascular development could be the cause.

Mojave toxin in venom of Crotalus helleri (Southern Pacific Rattlesnake): molecular and geographic characterization.

Mojave toxin (MT) was detected in five of 25 Crotalus helleri (Southern Pacific rattlesnake) sampled using anti-MT antibodies and nucleotide sequence analysis. All of the venoms that were positive for MT were collected from Mt San Jacinto in Riverside Co., California.

Additive effects of PDGF receptor beta signaling pathways in vascular smooth muscle cell development.

The platelet-derived growth factor beta receptor (PDGFRbeta) is known to activate many molecules involved in signal transduction and has been a paradigm for receptor tyrosine kinase signaling for many years. We have sought to determine the role of individual signaling components downstream of this receptor in vivo by analyzing an allelic series of tyrosine-phenylalanine mutations that prevent binding of specific signal transduction components. Here we show that the incidence of vascular smooth muscle cells/pericytes (v/p), a PDGFRbeta-dependent cell type, can be correlated to the amount of receptor expressed and the number of activated signal transduction pathways.