Survey of current trends in the management of traumatic subcutaneous emphysema in dogs.

BACKGROUND: Subcutaneous emphysema (SCE) is a common occurrence in emergency veterinary practice, but published information regarding treatment and management strategies is lacking. This study examined trends in diagnostic and treatment recommendations. STUDY DESIGN: An internet-based survey with cross-sectional analysis. There were 129 respondents: board-certified and nonboard-certified veterinarians in private practice and university settings. KEY FINDINGS: Significant differences in the choice of diagnostics and treatment were found based on the etiology and severity of SCE and between respondent groups. Computed tomography (CT) was selected more frequently for SCE resulting from blunt or penetrating traumas by the board-certified veterinarians practicing in a teaching hospital (VTH group; P < 0.001). All veterinarians were more likely to select tracheobronchoscopy as part of their workup for SCE as a result of endotracheal intubation trauma (P = 0.0093 [penetrating traumas]; P = 0.0002 [blunt force traumas]). Intermittent SC drainage and ventral cervical exploratory surgery were more likely to be chosen as treatments when SCE was classified as severe generalized (P < 0.0001). SIGNIFICANCE: There is significant variation in the treatment of SCE in veterinary medicine as well as associated diagnostics to determine severity and treatment options. Further studies are indicated to determine the optimal approach and provide guidance to clinicians.

Acute and endothelial-specific Robo4 deletion affect hematopoietic stem cell trafficking independent of VCAM1.

Hematopoietic stem cell (HSC) trafficking is regulated by a number of complex mechanisms. Among them are the transmembrane protein Robo4 and the vascular cell adhesion molecule, VCAM1. Endothelial VCAM1 is a well-known regulator of hematopoietic cell trafficking, and our previous studies revealed that germline deletion of Robo4 led to impaired HSC trafficking, with an increase in vascular endothelial cell (VEC) numbers and downregulation of VCAM1 protein on sinusoidal VECs. Here, we utilized two Robo4 conditional deletion models in parallel with Robo4 germline knockout mice (R4KO) to evaluate the effects of acute and endothelial cell-specific Robo4 deletion on HSC trafficking. Strikingly similar to the R4KO, the acute deletion of Robo4 resulted in altered HSC distribution between the bone marrow and blood compartments, despite normal numbers of VECs and wild-type levels of VCAM1 cell surface protein on sinusoidal VECs. Additionally, consistent with the R4KO mice, acute loss of Robo4 in the host perturbed long-term engraftment of donor wild-type HSCs and improved HSC mobilization to the peripheral blood. These data demonstrate the significant role that endothelial Robo4 plays in directional HSC trafficking, independent of alterations in VEC numbers and VCAM1 expression.