Temperature-dependence of early development of zebrafish and the consequences for laboratory use and animal welfare

by Angelina Miller, Katja Lisa Schröder, Karsten Eike Braun, Caitlin Steindorf, Richard Ottermanns, Martina Roß-Nickoll, Henner Hollert, Thomas Backhaus

Zebrafish (Danio rerio) are widely used in biological research, but the impact of incubation temperatures on developmental endpoints is still insufficiently studied. This study quantifies developmental differences in zebrafish embryos incubated at 26°C and 28°C, focusing on key endpoints (heartbeat onset, hatching time, eye size, yolk sac consumption, and body length). For this purpose, we recorded a high-resolution time series comprising hourly observations of early developmental stages and key events and bi-hourly observations of body length until 120 hours post fertilization. Additionally, we recorded a low-resolution time series at 72, 96, and 119 hours post fertilization for detailed measurements of eye size, yolk sac area, and body length. Embryos incubated at 26°C showed consistent delays in developmental stages compared to those at 28°C, with delays becoming more pronounced at later stages. Yolk sac consumption was delayed by about 19.8 hours at 26°C by 119 hours post fertilization, suggesting a delayed onset of independent feeding. These findings suggest that time-based regulatory limits for rearing zebrafish, such as the 120-hour threshold in German regulations (TierSchVerV), do not fully account for temperature-dependent development. The results emphasize the need for guidelines linking incubation temperatures to developmental progress.

Redirecting patients from the pediatric emergency department to community locations for care: A qualitative study of healthcare professional and leader perspectives

by Erica Qureshi, Quynh Doan, Jessica Moe, Steven P. Miller, Garth Meckler, Brett Burstein, Jehannine (J9) Austin

Objectives

Emergency department (ED) to community (ED2C) programs, which redirect patients from the pediatric ED to community healthcare professionals represent a promising strategy to reduce the impact of non-urgent visits on the pediatric ED. Given an ED2C program’s potential impact on various care professionals, we completed a qualitative study to explore key informants’ attitudes and perceptions of pediatric ED2C programs.

Methods

We conducted one-on-one semi-structured interviews with key informants in British Columbia, Canada. Participants included: pediatric ED staff – triage nurses and physicians; community professionals – pediatricians and family physicians; and health system leaders responsible for pediatric and emergency care in British Columbia. Interviews were recorded, transcribed verbatim, de-identified, and analyzed using reflexive thematic analysis within an interpretive description framework. A visual model was developed to depict key themes in attitudes and perceptions towards pediatric ED2C programs.

Results

We interviewed 24 participants: 6 community professionals, 11 pediatric ED professionals, and 7 healthcare leaders. Participants viewed the ED2C program as a valuable solution to address pediatric system strain provided that systemic barriers are addressed, and both emergency and community settings are equipped with adequate training and resources. Participants emphasized the need for clear guidelines on eligibility and operations to build confidence and enhance program effectiveness.

Conclusions

Our findings suggest there is support for ED2C programs as a means to reduce the impact of non-urgent pediatric ED visits and strengthen community-based care. Successful implementation will require coordinated planning, resource investment, and clear operational frameworks.

Design, 3D printing, and preclinical validation of an extraglottic ramp to facilitate blind orotracheal intubation in emergency airway management

by Jorman H. Tejada-Perdomo, Valentina Gutierrez-Perdomo, Juana V. Agudelo-Castro, Jorge A. Pérez-Gamboa, Alejandro Weinstein, Sebastián San Martín, Rodrigo Salas, Jorge A. Ramos-Castaneda

The use of devices that facilitate rapid airway isolation is essential when managing critical patients in emergencies. In recent years, additive manufacturing has emerged as an innovative, versatile, and accessible technology for developing medical devices. This study presents the design, development, and validation of an extraglottic medical device created using computer-aided design tools and stereolithographic 3D printing to facilitate blind intubation by first responders. The device was iteratively modeled and fabricated with biocompatible materials; validation in airway simulators and human cadaveric specimens assessed dimensions, friction, intubation technique, and learning curve, and ease of use was rated with a Likert scale. Ten iterations led to a final design with low friction and minimal cervical manipulation; ramp angle, cup geometry, and distal tip were optimized for tube passage, and BioMed Flex 80A showed high strength and anatomical compatibility. The final version is a safe, reusable, and functional alternative for airway management and blind orotracheal intubation, particularly in emergencies and resource-limited settings; clinical validation in live patients is still needed.