TREX1 degrades the 3' end of the small DNA oligonucleotide products of nucleotide excision repair in human cells.

The nucleotide excision repair (NER) machinery removes UV photoproducts from DNA in the form of small, excised damage-containing DNA oligonucleotides (sedDNAs) ∼30 nt in length. How cells process and degrade these byproducts of DNA repair is not known. Using a small scale RNA interference screen in UV-irradiated human cells, we identified TREX1 as a major regulator of sedDNA abundance. Knockdown of TREX1 increased the level of sedDNAs containing the two major UV photoproducts and their association with the NER proteins TFIIH and RPA. Overexpression of wild-type but not nuclease-inactive TREX1 significantly diminished sedDNA levels, and studies with purified recombinant TREX1 showed that the enzyme efficiently degrades DNA located 3' of the UV photoproduct in the sedDNA. Knockdown or overexpression of TREX1 did not impact the overall rate of UV photoproduct removal from genomic DNA or cell survival, which indicates that TREX1 function in sedDNA degradation does not impact NER efficiency. Taken together, these results indicate a previously unknown role for TREX1 in promoting the degradation of the sedDNA products of the repair reaction. Because TREX1 mutations and inefficient DNA degradation impact inflammatory and immune signaling pathways, the regulation of sedDNA degradation by TREX1 may contribute to photosensitive skin disorders.

"The Story I Will Never Forget": Critical Incident Narratives in Surgical Residency.

OBJECTIVE: We sought to better understand what defines a critical incident experience for the surgical trainee. SUMMARY BACKGROUND DATA: Critical incidents are formative moments stamped indelibly on one's memory that shape professional identity. The critical incident technique-using participants' narratives to identify patterns and learn from their perceptions-has been explored in some healthcare settings, but there has been no inquiry within surgery. METHODS: Surgical residents at 5 residency programs (1 community, 1 university-affiliated, 3 university) were surveyed using an online questionnaire from November to December 2020. Convenience sampling was used to identify the study population. Participants were invited to write about formative, impactful experiences in training. Interpretive description was the qualitative methodology used to locate information, analyze, and record patterns in the data. Individual responses were categorized and assessed for overlying themes. RESULTS: Overall, 28 narratives were collected from surgery residents in 3 specialties (general surgery, plastic surgery, and urology), with postgraduate year representation of post-graduate years 1 to 6. Respondents were 40% female. Nineteen of the narratives reported a negative experience. Four themes were identified from responses: 1) growth through personal self-reflection, 2) difficult interpersonal interactions, 3) positive team dynamics as a psychological safety net, and 4) supportive program cultures that promote learning. CONCLUSIONS: Critical incident narratives among surgical residents indicate that unforgettable and formative experiences-both positive and negative- occur in 4 domains: within the individual, within a relationship, among a team, and within a program. Further exploring these domains in surgical training will inform optimal educational programming to support trainee development and wellbeing.

The Demands of Surgery Residency: More Than Just Duty Hours?

INTRODUCTION: Efforts to improve surgical resident well-being could be accelerated with an improved understanding of resident job demands and resources. In this study, we sought to obtain a clearer picture of surgery resident job demands by assessing how residents distribute their time both inside and outside of the hospital. Furthermore, we aimed to elucidate residents' perceptions about current duty hour regulations. METHODS: A cross-sectional survey was sent to 1098 surgical residents at 27 US programs. Responses regarding work hours, demographics, well-being (utilizing the physician well-being index), and perceptions of duty hours in relation to education and rest, were collected. Data were evaluated using descriptive statistics and content analysis. RESULTS: A total of 163 residents (14.8% response rate) were included in the study. Residents reported a median total patient care hours per week of 78.0 h. Trainees spent 12.5 h on other professional activities. Greater than 40% of residents were "at risk" for depression and suicide based on physician well-being index scores. Four major themes associated with education and rest were identified: 1) duty hour definitions and reporting mechanisms do not completely reflect the amount of work residents perform, 2) quality patient care and educational opportunities do not fit neatly within the duty hour framework, 3) resident perceptions of duty hours are impacted the educational environment, and 4) long work hours and lack of adequate rest negatively affect well-being. CONCLUSIONS: The breadth and depth of trainee job demands are not accurately captured by current duty hour reporting mechanisms, and residents do not believe that their current work hours allow for adequate rest or even completion of other clinical or academic tasks outside of the hospital. Many residents are unwell. Duty hour policies and resident well-being may be improved with a more holistic accounting of resident job demands and greater attention to the resources that residents have to offset those demands.

Assessment of Determinants of Value in Carotid Endarterectomy.

BACKGROUND: Over 150,000 carotid endarterectomies (CEA) are performed annually worldwide, accounting for $900 million in the United States alone. How cost/spending and quality are related is not well understood but remain essential components in maximizing value. We sought to identify determinants of variability in hospital 90-day episode value for CEA. METHODS: Medicare and private-payer admissions for CEA from January 2, 2014 to August 28, 2020 were linked to retrospective clinical registry data for hospitals in Michigan performing vascular surgery. Hospital-specific, risk-adjusted, 30-day composite complications (defined as reoperation, new neurologic deficit, myocardial infarction, additional procedure including CEA or carotid artery stenting, readmission, or mortality) and 30-day risk-adjusted, price-standardized total episode payments were used to categorize hospitals into low or high value by defining the intersection between complications and spending. RESULTS: A total of 6,595 patients across 39 hospitals were identified across both datasets. Patients at low-value hospitals had a higher rate of 30-day composite complications (17.9% vs. 10.1%, P < 0.001) driven by a significantly higher rate of reoperation (3.0% vs. 1.4%, P = 0.016), readmission (10.7% vs. 6.2%, P = 0.012), new neurologic deficit (4.6% vs. 2.3%, P = 0.017), and mortality (1.6% vs. 0.6%, P < 0.049). Mean total episode payments were $19,635 at low-value hospitals compared to $15,709 at high-value hospitals driven by index hospitalization ($10,800 vs. $9,587, P = 0.002), professional ($3,421 vs. $2,827, P < 0.001), readmission ($3,011 vs. $1,826, P < 0.001), and post-acute care payments ($2,335 vs. $1,486, P < 0.001). Findings were similar when only including patients who did not suffer a complication. CONCLUSIONS: There is tremendous variation in both quality and payments across hospitals included for CEA. Importantly, costs were higher at low-value hospitals independent of postoperative complication. There appears to be little to no relationship between total episode spending and surgical quality, suggesting that improvements in value may be possible by decreasing total episode cost without affecting surgical outcomes.

Age and insulin-like growth factor-1 impact PCNA monoubiquitination in UVB-irradiated human skin.

Nonmelanoma skin cancers occur primarily in individuals over the age of 60 and are characterized by an abundance of ultraviolet (UV) signature mutations in keratinocyte DNA. Though geriatric skin removes UV photoproducts from DNA less efficiently than young adult skin, it is not known whether the utilization of other prosurvival but potentially mutagenic DNA damage tolerance systems such as translesion synthesis (TLS) is altered in older individuals. Using monoubiquitination of the replicative DNA polymerase clamp protein PCNA (proliferating cell nuclear antigen) as a biochemical marker of TLS pathway activation, we find that UVB exposure of the skin of individuals over the age of 65 results in a higher level of PCNA monoubiquitination than in the skin of young adults. Furthermore, based on previous reports showing a role for deficient insulin-like growth factor-1 (IGF-1) signaling in altered UVB DNA damage responses in geriatric human skin, we find that both pharmacological inhibition of the IGF-1 receptor (IGF-1R) and deprivation of IGF-1 potentiate UVB-induced PCNA monoubiquitination in both human skin ex vivo and keratinocytes in vitro. Interestingly, though the TLS DNA polymerase Pol eta can accurately replicate the major photoproducts induced in DNA by UV radiation, we find that it fails to accumulate on chromatin in the absence of IGF-1R signaling and that this phenotype is correlated with increased mutagenesis in keratinocytes in vitro. Thus, altered IGF-1/IGF-1R signaling in geriatric skin may predispose epidermal keratinocytes to carry out a more mutagenic form of DNA synthesis following UVB exposure.

Hardship and Humanity: A Closer Qualitative Look at Surgical Training and Its Effects on Trainees From the Perspectives of Loved Ones.

OBJECTIVE: The aim of this study was to obtain novel perspectives regarding the effects that surgical training has on the well-being of trainees. SUMMARY BACKGROUND DATA: Improving trainee well-being is a national concern given high rates of burnout, depression, and suicide among physicians. Supporters of surgical trainees may offer new perspectives regarding the effects of surgical training and point to strategies to optimize trainee wellness. METHODS: This qualitative study employs semi-structured interviews of 32 support persons of trainees at a single tertiary care center with multiple surgical training programs. Interviews focused on perspectives related to supporting a surgical trainee. Interview transcripts underwent qualitative analysis with semantic and conceptual coding. Themes related to effects of training on trainee wellness are reported. RESULTS: Four themes were identified: Who Can Endure the Most Hardship?-trainee attributes and programmatic factors contribute to trainees feeling the need to constantly endure the most hardship; Consequences of Hardship-constantly enduring hardships has significant negative effects on wellness; Trainees are Humans-trainees are people with basic human needs, especially the need for worth; Research Time as Refuge-dedicated research time is treated as an oasis away from clinical hardships. CONCLUSIONS: Perspectives from support persons can offer valuable insight into the wellness needs of surgical trainees. According to support persons, surgical training profoundly negatively impacts trainee wellness. Unlike during clinical training, dedicated research time is a period during which wellness can be prioritized. Programs should provide greater attention to mitigating the negative ramifications of surgical training and promoting wellness in a longitudinal fashion throughout training.

Reliability of hospital-level mortality in abdominal aortic aneurysm repair.

OBJECTIVE: The relationship between volume and surgical outcomes has been shown for a variety of surgical procedures. The effects in abdominal aortic aneurysm repair have continued to be debated. Reliability adjustment has been used as a method to remove statistical noise from hospital-level outcomes. However, its impact on aortic aneurysm repair is not well understood. METHODS: We used prospectively collected data from the Vascular Quality Initiative to identify all patients who had undergone abdominal aortic aneurysm repair from 2003 to 2019. We first calculated the hospital-level risk-adjusted 30-day mortality rates. We subsequently used hierarchical logistic regression modeling to adjust for measurement reliability using empirical Bayes techniques. The effect of volume on risk- and reliability-adjusted mortality rates was then assessed using linear regression. RESULTS: Between 2003 and 2019, 67,073 abdominal aortic aneurysms were repaired, of which 11,601 (17.3%) were repaired with an open approach. The median annual volume was 7.4 (interquartile range, 3.0-13.3) for open repairs and 35.4 (interquartile range, 18.8-59.8) for endovascular repairs. Of the 223 hospitals that had performed open repairs during the study period, only 11 (4.9%) had performed ≥15 open repairs annually, and the risk-adjusted mortality rates varied from 0% to 75% across all centers. After reliability adjustment, the variability of the risk-adjusted mortality rates had decreased significantly to 1.3% to 8.2%. The endovascular repair risk-adjusted mortality rate variability had decreased from 0% to 14.3% to 0.3% to 2.8% after reliability adjustment. A decreasing trend in mortality was found with increasing an annual case volume for open repair with each additional annual case associated with a 0.012% decrease in mortality (P = .05); however, the relationship was not significant for endovascular repair (P = .793). CONCLUSIONS: We found that most hospitals do not perform a sufficient number of annual cases to generate a reliable center-specific mortality rate for open aneurysm repair. Center-specific mortality rates for low-volume centers should be viewed with caution, because a substantial proportion of the variation for these outcomes will be statistical noise rather than true center-level differences in the quality of care.

Testing for syphilis.

Syphilis is no longer a disease headed for the history books but a disease on the resurgence. Its rising prevalence in populations of all sexualities has moved it from an unlikely differential diagnosis to an important one not to miss. With a latency to symptoms of sometimes many years, syphilis is a key disease to consider and does not need the clinician to attempt to risk assess the patient. This article seeks to equip the jobbing neurologist to recognise the manifestations of syphilis, and to understand the tests available, the interpretation of results and the limitations of testing. We provide an overview approach to assessing and managing these cases, what to expect and where to seek expert opinion and advice.

Not Just Bystanders: A Qualitative Study on the Vicarious Effects of Surgical Training on the Wellness of Support Persons for Trainees.

OBJECTIVE: To obtain insights into the effects of surgical training on the well-being of support persons. SUMMARY BACKGROUND DATA: Surgical trainee wellness is a critical priority among surgical educators and leaders. The impact of surgical training on the wellness of loved ones who support trainees has not been previously studied. METHODS: This qualitative study employs semi-structured interviews of 32 support persons of surgical trainees at a single tertiary care center with multiple surgical specialty training programs. Interviews focused on perceptions about supporting a surgical trainee. Transcripts underwent thematic analysis with semantic and conceptual coding. Key themes regarding the effects that caring for a trainee has on support persons are reported. RESULTS: Three key themes were identified: (1) Sacrifices-support persons report significant tangible and intangible sacrifices, (2) Delaying life-life is placed on hold to prioritize training, and (3) A disconnect-there is a disconnect and a lack of recognition of support person needs that require greater awareness and targeted interventions. CONCLUSIONS: The impact of surgical training can extend beyond trainees and can affect the wellness of their support persons who endure the effects of training alongside trainees. Programs should be aware of these effects and develop meaningful strategies to aid trainees and their support persons.

Surgery Provider Perceptions on Telehealth Visits During the COVID-19 Pandemic: Room for Improvement.

BACKGROUND: COVID-19 has mandated rapid adoption of telehealth for surgical care. However, many surgical providers may be unfamiliar with telehealth. This study evaluates the perspectives of surgical providers practicing telehealth care during COVID-19 to help identify targets for surgical telehealth optimization. MATERIALS AND METHODS: At a single tertiary care center with telehealth capabilities, all department of surgery providers (attending surgeons, residents, fellows, and advanced practice providers) were emailed a voluntary survey focused on telehealth during the pandemic. Descriptive statistics and Mann-Whitney U analyses were performed as appropriate on responses. Text responses were thematically coded to identify key concepts. RESULTS: The completion rate was 41.3% (145/351). Providers reported increased telehealth usage relative to the pandemic (P < 0.001). Of respondents, 80% (116/145) had no formal telehealth training. Providers estimated that new patient video visits required less time than traditional visits (P = 0.001). Satisfaction was high for several aspects of video visits. Comparatively lower satisfaction scores were reported for the ability to perform physical exams (sensitive and nonsensitive) and to break bad news. The largest barriers to effective video visits were limited physical exams (55.6%; 45/81) and lack of provider or patient internet access/equipment/connection (34.6%; 28/81). Other barriers included ineffective communication and difficulty with fostering rapport. Concerns regarding video-to-telephone visit conversion were loss of physical exam/visual cues (34.3%; 24/70), less personal interactions (18.6%; 13/70), and reduced efficiency (18.6%; 13/70). CONCLUSIONS: Telehealth remains a new experience for surgical providers despite its expansion. Optimization strategies should target technology barriers and include specialized virtual exam and communication training.

Valproic Acid Protects Against Acute Kidney Injury in Hemorrhage and Trauma.

INTRODUCTION: Trauma is the leading cause of death among young people. These patients have a high incidence of kidney injury, which independently increases the risk of mortality. As valproic acid (VPA) treatment has been shown to improve survival in animal models of lethal trauma, we hypothesized that it would also attenuate the degree of acute kidney injury. METHODS: We analyzed data from two separate experiments where swine were subjected to lethal insults.  Model 1: hemorrhage (50% blood volume hemorrhage followed by 72-h damage control resuscitation). Model 2: polytrauma (traumatic brain injury, 40% blood volume hemorrhage, femur fracture, rectus crush and grade V liver laceration). Animals were resuscitated with normal saline (NS) +/- VPA 150 mg/kg after a 1-h shock phase in both models (n = 5-6/group). Serum samples were analyzed for creatinine (Cr) using colorimetry on a Liasys 330 chemistry analyzer. Proteomic analysis was performed on kidney tissue sampled at the time of necropsy. RESULTS: VPA treatment significantly (P < 0.05) improved survival in both models. (Model 1: 80% vs 20%; Model 2: 83% vs. 17%). Model 1 (Hemorrhage alone): Cr increased from a baseline of 1.2 to 3.0 in NS control animals (P < 0.0001) 8 h after hemorrhage, whereas it rose only to 2.1 in VPA treated animals (P = 0.004). Model 2 (Polytrauma): Cr levels increased from baseline of 1.3 to 2.5 mg/dL (P = 0.01) in NS control animals 4 h after injury but rose to only 1.8 in VPA treated animals (P = 0.02). Proteomic analysis of kidney tissue identified metabolic pathways were most affected by VPA treatment. CONCLUSIONS: A single dose of VPA (150 mg/kg) offers significant protection against acute kidney injury in swine models of polytrauma and hemorrhagic shock.

Assessment of the Cytoprotective Effects of High-Dose Valproic Acid Compared to a Clinically Used Lower Dose.

OBJECTIVE: Valproic acid (VPA) treatment improves survival in animal models of injuries on doses higher than those allowed by Food and Drug Administration (FDA). We investigated the proteomic alterations induced by a single high-dose (140mg/kg) of VPA (VPA140) compared to the FDA-approved dose of 30mg/kg (VPA30) in healthy humans. We also describe the proteomic and transcriptomic changes induced by VPA140 in an injured patient. We hypothesized that VPA140 would induce cytoprotective changes in the study participants. METHODS: Serum samples were obtained from healthy subjects randomized to two groups; VPA140 and VPA30 at 3 timepoints: 0h(baseline), 2h, and 24h following infusion(n = 3/group). Samples were also obtained from an injured patient that received VPA140 at 0h, 6h and 24h following infusion. Proteomic analyses were performed using liquid chromatography-mass spectrometry (LC-MS/MS), and transcriptomic analysis was performed using RNA-sequencing. Differentially expressed (DE) proteins and genes were identified for functional annotation and pathway analysis using iPathwayGuide and gene set enrichment analysis (GSEA), respectively. RESULTS: For healthy individuals, a dose comparison was performed between VPA140 and VPA30 groups at 2 and 24 h. Functional annotation showed that top biological processes in VPA140 versus VPA30 analysis at 2 h included regulation of fatty acid (P = 0.002) and ATP biosynthesis (P = 0.007), response to hypoxia (P = 0.017), cell polarity regulation (P = 0.031), and sequestration of calcium ions (P = 0.031). Top processes at 24 h in VPA140 versus VPA30 analysis included amino acid metabolism (P = 0.023), collagen catabolism (P = 0.023), and regulation of protein breakdown (P = 0.023). In the injured patient, annotation of the DE proteins in the serum showed that top biological processes at 2 h included neutrophil chemotaxis (P = 0.002), regulation of cellular response to heat (P = 0.008), regulation of oxidative stress (P = 0.008) and regulation of apoptotic signaling pathway (P = 0.008). Top biological processes in the injured patient at 24 h included autophagy (P = 0.01), glycolysis (P = 0.01), regulation of apoptosis (P = 0.01) and neuron apoptotic processes (P = 0.02). CONCLUSIONS: VPA140 induces cytoprotective changes in human proteome not observed in VPA30. These changes may be responsible for its protective effects in response to injuries.

Twelve tips for the integration of medical students into telemedicine visits.

The use of telemedicine in clinical care has grown significantly in the last few years and has only increased during the COVID-19 pandemic. Given that many physicians will be expected to deliver virtual care moving forward, it is important for medical students to gain exposure via this modality during their clinical training. Many medical schools are actively working to integrate students into telemedicine. This article aims to provide guidance for readers incorporating medical students in telemedicine visits at an institutional or departmental level. This article covers essential topics such as coordinating key stakeholders, conducting needs assessments, addressing technological or software considerations, and creating appropriate workflows for students and physicians.

The Impact of the Circadian Clock on Skin Physiology and Cancer Development.

Skin cancers are growing in incidence worldwide and are primarily caused by exposures to ultraviolet (UV) wavelengths of sunlight. UV radiation induces the formation of photoproducts and other lesions in DNA that if not removed by DNA repair may lead to mutagenesis and carcinogenesis. Though the factors that cause skin carcinogenesis are reasonably well understood, studies over the past 10-15 years have linked the timing of UV exposure to DNA repair and skin carcinogenesis and implicate a role for the body's circadian clock in UV response and disease risk. Here we review what is known about the skin circadian clock, how it affects various aspects of skin physiology, and the factors that affect circadian rhythms in the skin. Furthermore, the molecular understanding of the circadian clock has led to the development of small molecules that target clock proteins; thus, we discuss the potential use of such compounds for manipulating circadian clock-controlled processes in the skin to modulate responses to UV radiation and mitigate cancer risk.

Calcineurin inhibitor (CNI)-associated skin cancers: New insights on exploring mechanisms by which CNIs downregulate DNA repair machinery.

The use of the calcineurin inhibitors (CNI) cyclosporine (CsA) and tacrolimus remains a cornerstone in post-transplantation immunosuppression. Although these immunosuppressive agents have revolutionized the field of transplantation medicine, its increased skin cancer risk poses a major concern. A key contributor to this phenomenon is a reduced capacity to repair DNA damage caused by exposure to ultraviolet (UV) wavelengths of sunlight. CNIs decrease DNA repair by mechanisms that remain to be fully explored. Though CsA is known to decrease the abundance of key DNA repair enzymes, less is known about how tacrolimus yields this effect. CNIs hold the capacity to inhibit both of the main catalytic calcineurin isoforms (CnAα and CnAß). However, it is unknown which isoform regulates UV-induced DNA repair, which is the focus of this review. It is with hope that this insight spurs investigative efforts that conclusively addresses these gaps in knowledge. Additionally, this research also raises the possibility that newer CNIs can be developed that effectively blunt the immune response while mitigating the incidence of skin cancers with immunosuppression.

Unmuting Medical Students' Education: Utilizing Telemedicine During the COVID-19 Pandemic and Beyond.

Due to the coronavirus disease (COVID-19) pandemic, medical schools have paused traditional clerkships, eliminating direct patient encounters from medical students' education for the immediate future. Telemedicine offers opportunities in a variety of specialties that can augment student education during this time. The projected growth of telemedicine necessitates that students learn new skills to be effective providers. In this viewpoint, we delineate specific telehealth opportunities that teach core competencies for patient care, while also teaching telemedicine-specific skills. Schools can further augment student education through a variety of telemedicine initiatives across multiple medical fields. The explosion of telemedicine programs due to the pandemic can be a catalyst for schools to integrate telemedicine into their current curricula. The depth and variety of telemedicine opportunities allow schools to continue providing high-quality medical education while maintaining social distancing policies.

Interaction between DUE-B and Treslin is required to load Cdc45 on chromatin in human cells.

A key step in the initiation of eukaryotic DNA replication is the binding of the activator protein Cdc45 to promote MCM helicase unwinding of the origin template. We show here that the c-myc origin DNA unwinding element-binding protein, DUE-B, interacts in HeLa cells with the replication initiation protein Treslin to allow Cdc45 loading onto chromatin. The chromatin loading of DUE-B and Treslin are mutually dependent, and the DUE-B-Treslin interaction is cell cycle-regulated to peak as cells exit G1 phase prior to the initiation of replication. The conserved C-terminal domain of DUE-B is required for its binding to TopBP1, Treslin, Cdc45, and the MCM2-7 complex, as well as for the efficient loading of Treslin, Cdc45, and TopBP1 on chromatin. These results suggest that DUE-B acts to identify origins by MCM binding and serves as a node for replication protein recruitment and Cdc45 transfer to the prereplication complex.

Plasmodium cynomolgi as Cause of Malaria in Tourist to Southeast Asia, 2018.

We report human infection with simian Plasmodium cynomolgi in a tourist from Denmark who had visited forested areas in peninsular Malaysia and Thailand in August and September 2018. Because P. cynomolgi may go unnoticed by standard malaria diagnostics, this malaria species may be more common in humans than was previously thought.

And-1 coordinates with Claspin for efficient Chk1 activation in response to replication stress.

The replisome is important for DNA replication checkpoint activation, but how specific components of the replisome coordinate with ATR to activate Chk1 in human cells remains largely unknown. Here, we demonstrate that And-1, a replisome component, acts together with ATR to activate Chk1. And-1 is phosphorylated at T826 by ATR following replication stress, and this phosphorylation is required for And-1 to accumulate at the damage sites, where And-1 promotes the interaction between Claspin and Chk1, thereby stimulating efficient Chk1 activation by ATR. Significantly, And-1 binds directly to ssDNA and facilitates the association of Claspin with ssDNA. Furthermore, And-1 associates with replication forks and is required for the recovery of stalled forks. These studies establish a novel ATR-And-1 axis as an important regulator for efficient Chk1 activation and reveal a novel mechanism of how the replisome regulates the replication checkpoint and genomic stability.