A Life Cycle Assessment of Reusable and Disposable Surgical Caps.

INTRODUCTION: Surgical cap attire plays an important role in creating a safe and sterile environment in procedural suites, thus the choice of reusable versus disposable caps has become an issue of much debate. Given the lack of evidence for differences in surgical site infection (SSI) risk between the two, selecting the cap option with a lower carbon footprint may reduce the environmental impact of surgical procedures. However, many institutions continue to recommend the use of disposable bouffant caps. METHODS: ISO-14044 guidelines were used to complete a process-based life cycle assessment to compare the environmental impact of disposable bouffant caps and reusable cotton caps, specifically focusing on CO2 equivalent (CO2e) emissions, water use and health impacts. RESULTS: Reusable cotton caps reduced CO2e emissions by 79% when compared to disposable bouffant caps (10 kg versus 49 kg CO2e) under the base model scenario with a similar reduction seen in disability-adjusted life years. However, cotton caps were found to be more water intensive than bouffant caps (67.56 L versus 12.66 L) with the majority of water use secondary to production or manufacturing. CONCLUSIONS: Reusable cotton caps have lower total lifetime CO2e emissions compared to disposable bouffant caps across multiple use scenarios. Given the lack of evidence suggesting a superior choice for surgical site infection prevention, guidelines should recommend reusable cotton caps to reduce the environmental impact of surgical procedures.

The Carbon Footprint of Residency Interview Travel.

BACKGROUND: Over the last decade, medical student residency applicants have shown a substantial increase in the number of interviews attended, which is associated with a significant increase in travel. The carbon footprint associated with residency interviews has not been well documented prior to this investigation, and is a critical issue related to climate health. OBJECTIVE: The purpose of this study is to document the carbon footprint associated with travel to residency interviews of the applicants from a single institution. METHODS: Graduating medical students from the University of Michigan Medical School were surveyed in 2020 to gather information regarding travel related to residency interviews. A validated carbon emissions calculator was used to determine the associated carbon footprint. RESULTS: Response rate was 103 of 174 (59%). Average interviews per student across all specialties was 14.39 interviews per student. The overall class average for total carbon footprint per student was calculated as 3.07 metric tons CO2, making the class average carbon footprint per interview 0.21 metric tons CO2. If we extrapolate the results of our study to all residents, the resulting CO2 emissions approach 51 665 metric tons CO2 per year, which is equivalent to the amount of CO2 produced by 11 162 passenger cars in 1 year. CONCLUSIONS: Medical education leaders could help reduce the carbon footprint by encouraging a reduction in number of in-person interviews attended by applicants.

A comparative carbon footprint analysis of disposable and reusable vaginal specula.

BACKGROUND: Healthcare systems in the United States have increasingly turned toward the use of disposable medical equipment in an attempt to save time, lower costs, and reduce the transmission of infections. However, the use of disposable instruments is associated with increased solid waste production and may have negative impacts on the environment, such as increased greenhouse gas emissions. OBJECTIVE: The purpose of this study was to inform this discussion; we applied life cycle assessment methods to evaluate the carbon footprints of 3 vaginal specula: a single-use acrylic model and 2 reusable stainless steel models. STUDY DESIGN: The functional unit of the study was defined as the completion of 20 gynecologic examinations by either type of speculum. The greenhouse gas emissions (eg, carbon dioxide, methane, nitrous oxide) across all life cycle stages, which includes material production and manufacturing, transportation, use and reprocessing, and end-of-life, were analyzed with the use of SimaPro life cycle assessment software and converted into carbon dioxide equivalents. RESULTS: The reusable stainless steel grade 304 speculum was found to have a lesser carbon footprint over multiple model scenarios (different reprocessing techniques, autoclave loading/efficiency, and number of uses) than either the reusable stainless steel grade 316 or the disposable acrylic specula. The material production and manufacturing phase contributed most heavily to the total life cycle carbon footprint of the acrylic speculum, whereas the use and reprocessing phase contributed most to the carbon footprints of both stainless steel specula. CONCLUSION: The use of disposable vaginal specula is associated with increased greenhouse gas equivalents compared with reusable alternatives with no significant difference in clinical utility. These findings can be used to inform decision-making by healthcare systems, because they weigh a wide range of considerations in making final purchase decisions; similar analytic methods can and should be applied to other components of health systems' waste streams.

CD2-associated protein (CD2AP) enhances casitas B lineage lymphoma-3/c (Cbl-3/c)-mediated Ret isoform-specific ubiquitination and degradation via its amino-terminal Src homology 3 domains.

Ret is the receptor tyrosine kinase for the glial cell line-derived neurotrophic factor (GDNF) family of neuronal growth factors. Upon activation by GDNF, Ret is rapidly polyubiquitinated and degraded. This degradation process is isoform-selective, with the longer Ret51 isoform exhibiting different degradation kinetics than the shorter isoform, Ret9. In sympathetic neurons, Ret degradation is induced, at least in part, by a complex consisting of the adaptor protein CD2AP and the E3-ligase Cbl-3/c. Knockdown of Cbl-3/c using siRNA reduced the GDNF-induced ubiquitination and degradation of Ret51 in neurons and podocytes, suggesting that Cbl-3/c was a predominant E3 ligase for Ret. Coexpression of CD2AP with Cbl-3/c augmented the ubiquitination of Ret51 as compared with the expression of Cbl-3/c alone. Ret51 ubiquitination by the CD2AP·Cbl-3/c complex required a functional ring finger and TKB domain in Cbl-3/c. The SH3 domains of CD2AP were sufficient to drive the Cbl-3/c-dependent ubiquitination of Ret51, whereas the carboxyl-terminal coiled-coil domain of CD2AP was dispensable. Interestingly, activated Ret induced the degradation of CD2AP, but not Cbl-3/c, suggesting a potential inhibitory feedback mechanism. There were only two major ubiquitination sites in Ret51, Lys(1060) and Lys(1107), and the combined mutation of these lysines almost completely eliminated both the ubiquitination and degradation of Ret51. Ret9 was not ubiquitinated by the CD2AP·Cbl-3/c complex, suggesting that Ret9 was down-regulated by a fundamentally different mechanism. Taken together, these results suggest that only the SH3 domains of CD2AP were necessary to enhance the E3 ligase activity of Cbl-3/c toward Ret51.