Transcriptional silencing of a transgene by RNAi in the soma of C. elegans

The silencing of transgene expression at the level of transcription in the soma of Caenorhabditis elegans through an RNAi-dependent pathway has not been previously characterized. Most gene silencing due to RNAi in C. elegans occurs at the post-transcriptional level. We observed transcriptional silencing when worms containing the elt-2::gfp/LacZ transgene were fed RNA produced from the commonly used L4440 vector. The transgene and the vector share plasmid backbone sequences. This transgene silencing depends on multiple RNAi pathway genes, including dcr-1, rde-1, rde-4, and rrf-1. Unlike post-transcriptional gene silencing in worms, elt-2::gfp/LacZ silencing is dependent on the PAZ-PIWI protein Alg-1 and on the HP1 homolog Hpl-2. The latter is a chromatin silencing factor, and expression of the transgene is inhibited at the level of intron-containing precursor mRNA. This inhibition is accompanied by a decrease in the acetylation of histones associated with the transgene. This transcriptional silencing in the soma can be distinguished from transgene silencing in the germline by its inability to be transmitted across generations and its dependence on the rde-1 gene. We therefore define this type of silencing as RNAi-induced Transcriptional Gene Silencing (RNAi-TGS). Additional chromatin-modifying components affecting RNAi-TGS were identified in a candidate RNAi screen

Use of Remifentanil for Open in utero Fetal Myelomeningocele Repair Maintains Uterine Relaxation with Reduced Volatile Anesthetic Concentration

IntroductionOpen fetal repair of myelomeningocele (MMC) is an option for prenatally diagnosed spina bifida. Historically, high-dose volatile anesthetic was used for uterine relaxation but is associated with fetal cardiovascular depression. We examined the impact of administering a supplemental remifentanil infusion on the concentration of inhaled anesthetic required for intraoperative uterine relaxation.MethodsWe retrospectively analyzed 22 consecutive patients who underwent open fetal MMC repair with desflurane anesthesia from 2014 to 2018. The anesthetic protocol was modified to include high-dose opioid with remifentanil in 2016. We examined intraoperative end-tidal desflurane concentrations, vasopressor use, incidence of umbilical artery Doppler abnormalities, and incidence of preterm labor and delivery.ResultsPatients (n = 11) who received desflurane and remifentanil (Des/Remi) were compared to patients (n = 11) who received desflurane (Des) alone. Intraoperatively, the maximum end-tidal desflurane required to maintain uterine relaxation was lower in the Des/Remi group (7.9 ± 2.2% vs. 13.1 ± 1.2%, p < 0.001). The mean phenylephrine infusion rate was also lower in the Des/Remi group (36 ± 14 vs. 53 ± 10 mcg/min, p = 0.004).DiscussionUse of opioid with supplemental remifentanil was associated with lower volatile anesthetic dosing and decreased vasopressor use; fetal outcomes were not different. Remifentanil may allow for less volatile anesthetic use while maintaining adequate uterine relaxation

Drivers of Well-Being and Burnout in Anesthesiology Residents.

BACKGROUND: With more than 50% of anesthesiology residents reporting burnout, many residency programs have begun creating wellness programs to address burnout and promote well-being. However, to date, many wellness initiatives have focused on individual strategies rather than systems approaches to improve the learning environment. Individual-focused interventions in the absence of systematic efforts can lead to resentment, resistance, and worsening burnout and precipitate a loss of trust in leadership and the organization. Here, we describe a process to engage anesthesiology residents, who are key stakeholders, by exploring their perspectives on burnout and well-being to better inform systematic interventions to improve the clinical work and learning environments. METHODS: We conducted semistructured interviews with second- and third-year clinical anesthesia residents at the University of California, San Francisco, using the areas of worklife model as sensitizing concepts. We conducted a thematic analysis on transcribed interviews grounded in constructivist orientation. RESULTS: We identified the following 3 major categories of themes based on interviews with 10 residents: (1) definition of well-being, (2) challenges to well-being, and (3) strategies for coping with challenges and burnout. Challenges described by anesthesiology residents align with the areas of the worklife model, with the coronavirus disease 2019 pandemic precipitating additional threats in the domains of workload and community. CONCLUSIONS: Anesthesiology residents definition of well-being includes both individual (resilience) and systemic (meaning in work, job autonomy, and control) factors, reaffirming that positive work and learning environments are critical to professional well-being