Fenestrated endovascular aortic repair of a superior mesenteric artery aneurysm using carbon dioxide angiography and intravascular ultrasound.

Superior mesenteric artery aneurysms are rare; however, current guidelines suggest they all require repair due to the high rupture and mortality rates, and endovascular repair is an effective management strategy. Iodinated contrast traditionally used in endovascular repair can cause significant complications, including severe allergic reactions and contrast-induced nephropathy in patients with chronic renal disease. Therefore, other imaging methods should be used during endovascular procedures to reduce these risks. We describe a unique and innovative approach using carbon dioxide angiography and intravascular ultrasound during fenestrated endovascular repair of an uncommon superior mesenteric artery aneurysm in a patient with severe contrast allergies.

FROST 2.0: Factors Predicting Orthopaedic Trauma Volumes - A Validation Study.

The anecdotal relationship between weather, season, and orthopaedic trauma volumes is understood by patients and healthcare providers: when the winter ground is icy, people fall. Previous research established that winter and summer months as well as ice and snow were significant predictors of orthopaedic trauma and surges in volumes. The current study validates the previously established predictive model in one Canadian city; the original methods were repeated using a new, yet geographically similar dataset. The effect of month and ice were consistent, which suggests the proposed model has sufficient external validity to guide resource allocation and primary prevention strategies.

Orthopaedic trauma on the weekend: Longer surgical wait times, and increased after-hours surgery.

INTRODUCTION: Orthopaedic trauma does not present in a linear fashion. Fluctuations in trauma volumes, after-hours surgery and surgical wait times impact orthopaedic surgeons and patients. There is little research focussing on how surgical trauma volumes change throughout the week. This study investigated the relationship between day of the week and surgical orthopaedic trauma volumes, after-hours surgery, and wait times for orthopaedic trauma patients. METHODS: All unscheduled surgical orthopaedic trauma cases presenting to one level I and three level IV urban adult trauma centers between 2008 and 2018 were retrospectively reviewed. Fluctuations in orthopaedic trauma volumes and amount of after-hours surgeries completed were investigated using Multivariable Poisson regression. Fluctuations in patient wait times were investigated using linear regression. RESULTS: Weekends were associated with increased surgical wait times (8.9%, p<0.001) despite decreased surgical trauma volumes (9.1%, p<0.001). Surgical orthopaedic trauma volumes were elevated on weekdays and decreased on weekends. More after-hours surgeries were performed from Thursday to Saturday with most performed on Friday night (26.6%, p<0.001). Surgical wait times increased midweek and remained high until Saturday. CONCLUSION: With a lack of dedicated trauma resources on the weekend, a significant increase in after-hours surgery and surgical wait times was identified following surgical volumes peaking on Thursday and Friday. We suggest adapting resource allocation to reflect surgical volumes. Dedicated weekend orthopaedic trauma resources or an adaptable schedule during increased orthopaedic trauma have the potential to ease this bottleneck, improve patient care, and decrease hospital costs.

Inhibition of Oocyte Maturation by Malathion and Structurally Related Chemicals in Zebrafish (Danio rerio) After In Vitro and In Vivo Exposure.

Oogenesis is the process by which a primary oocyte develops into a fertilizable oocyte, making it critical to successful reproduction in fish. In zebrafish (Danio rerio), there are five stages of oogenesis. During the final step (oocyte maturation), the maturation-inducing hormone 17α,20ß-dihydroxy-4-pregnen-3-one (MIH) activates the membrane progestin receptor, inducing germinal vesicle breakdown. Using in vitro assays, it has been shown that anthropogenic stressors can dysregulate MIH-induced oocyte maturation. However, it is unknown whether the in vitro assay is predictive of reproductive performance after in vivo exposure. We demonstrate that a known inhibitor of oocyte maturation, malathion, and a structurally related chemical, dimethoate, inhibit oocyte maturation. However, malaoxon and omethoate, which are metabolites of malathion and dimethoate, did not inhibit oocyte maturation. Malathion and dimethoate inhibited maturation to a similar magnitude when oocytes were exposed for 4 h in vitro or 10 days in vivo, suggesting that the in vitro zebrafish oocyte maturation assay might be predictive of alterations to reproductive performance. However, when adult zebrafish were exposed to malathion for 21 days, there was no alteration in fecundity or fertility in comparison with control fish. Our study supports the oocyte maturation assay as being predictive of the success of in vitro oocyte maturation after in vivo exposure, but it remains unclear whether inhibition of MIH-induced oocyte maturation in vitro correlates to decreases in reproductive performance. Environ Toxicol Chem 2022;41:1381-1389. © 2022 SETAC.

The brominated flame retardant, TBCO, impairs oocyte maturation in zebrafish (Danio rerio).

The brominated flame retardant, 1,2,5,6-tetrabromocyclooctane (TBCO), has been shown to decrease fecundity in Japanese medaka (Oryzias latipes) and there is indirect evidence from analysis of the transcriptome and proteome that this effect might be due to impaired oogenesis. An assay for disruption of oocyte maturation by chemical stressors has not been developed in Japanese medaka. Thus, using zebrafish (Danio rerio) as a model, objectives of the present study were to determine whether exposure to TBCO has effects on maturation of oocytes and to investigate potential mechanisms. Sexually mature female zebrafish were given a diet of 35.3 or 628.8 µg TBCO / g food for 14 days after which, stage IV oocytes were isolated to assess maturation in response to maturation inducing hormone. To explore potential molecular mechanisms, abundances of mRNAs of a suite of genes that regulate oocyte maturation were quantified by use of quantitative real-time PCR, and abundances of microRNAs were determined by use of miRNAseq. Ex vivo maturation of oocytes from fish exposed to TBCO was significantly less than maturation of oocytes from control fish. The percentage of oocytes which matured from control fish and those exposed to low and high TBCO were 89, 71, and 67%, respectively. Among the suite of genes known to regulate oocyte maturation, mRNA abundance of insulin like growth factor-3 was decreased by 1.64- and 3.44-fold in stage IV oocytes from females given the low and high concentrations of TBCO, respectively, compared to the control group. Abundances of microRNAs regulating the expression of proteins that regulate oocyte maturation, including processes related to insulin-like growth factor, were significantly different in stage IV oocytes from fish exposed to TBCO. Overall, results of this study indicated that impaired oocyte maturation might be a mechanism of reduced reproductive performance in TBCO-exposed fish. Results also suggested that effects of TBCO on oocyte maturation might be due to molecular perturbations on insulin-like growth factor signaling and expression of microRNAs.

Effects of the brominated flame retardant, TBCO, on development of zebrafish (Danio rerio) embryos.

Brominated flame retardants (BFRs) can enter aquatic environments where they can have adverse effects on organisms. The BFR, 1,2,5,6-Tetrabromocyclooctane (TBCO), has been introduced as a potential replacement for the major use BRF, Hexabromocyclododecane (HBCD). However, little is known about effects of TBCO on aquatic organisms. Using zebrafish (Danio rerio) as a model species, objectives of this study were to determine whether TBCO has adverse effects on early life-stages and to investigate the molecular and biochemical mechanisms of any effects on development. Exposure to TBCO caused a concentration dependant increase in mortality, decrease in heart rate, and increase in incidences of spinal curvature and uninflated swim bladders. Neither peroxidation of lipids or mRNA abundances of genes important for the response to oxidative stress were greater in embryos exposed to TBCO suggesting effects were not caused by oxidative stress. The mRNA abundance of cytochrome p4501a was not greater in embryos exposed to TBCO suggesting that effects were not caused by activation of the aryl hydrocarbon receptor. Finally, mRNA abundances of genes important for development and inflation of the swim bladder were not affected by TBCO. Overall, TBCO causes adverse effects on early life-stages of zebrafish, but mechanisms of effects require further investigation.