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Hip pain in children is common, with causes ranging from the benign to destructive. This article reviews slipped capital femoral epiphysis (SCFE), one of the most common hip pathologies in preadolescents and adolescents, which often is missed or delayed in diagnosis because of its vague, atypical presentation.

People who identify as African Americans, Latinos, or from indigenous backgrounds, are dramatically underrepresented in the U.S. physician workforce. It is critical for academic health centers to recognize racial and ethnic diversity at the residency level and implement changes to enhance diversity among trainees.The Office of Graduate Medical Education (GME) at the University of Pennsylvania Health System (UPHS) developed a multipronged approach to enhance diversity and inclusion (DI) among residency trainees. The approach included the development of an underrepresented in medicine (UIM) professional network; UIM-focused visiting clerkship programs; holistic review implementation by selection committees; and targeted outreach to UIM candidates, overseen by an associate designated institutional official for UIM Affairs. The authors reported demographic data on residency applicants invited for interviews and matching for all programs at UPHS from 2014-2015 (baseline) to 2020-2021. They also reported data on maximum ranking number programs reached to fill their positions and the average United States Medical License Examination (USMLE) Step 1 scores of matched candidates. Finally, they discussed the implications for leaders who wish to enhance DI at academic health centers.During the baseline year (2014-2015), UIMs represented 12.1% of interviewees and 8.7% of all matched candidates into UPHS residency programs. Over the successive 6 years after incremental implementation of the approach, UIM representation steadily increased. In 2020-2021, UIMs represented 23.2% of interviewees and 26.4% of matched candidates. Programs' maximum rank number to fill and USMLE Step 1 scores of matched candidates remained relatively unchanged.The UPHS Office of GME incorporated a purposeful approach to enhance the DI of its residents. Across 6 years of implementation, UIM representation among resident matches tripled while quantitative program and candidate metrics remained unchanged. Similar efforts should be given further consideration for implementation and evaluation nationwide.

NOTCH1 mutant clones occupy the majority of normal human esophagus by middle age but are comparatively rare in esophageal cancers, suggesting NOTCH1 mutations drive clonal expansion but impede carcinogenesis. Here we test this hypothesis. Sequencing NOTCH1 mutant clones in aging human esophagus reveals frequent biallelic mutations that block NOTCH1 signaling. In mouse esophagus, heterozygous Notch1 mutation confers a competitive advantage over wild-type cells, an effect enhanced by loss of the second allele. Widespread Notch1 loss alters transcription but has minimal effects on the epithelial structure and cell dynamics. In a carcinogenesis model, Notch1 mutations were less prevalent in tumors than normal epithelium. Deletion of Notch1 reduced tumor growth, an effect recapitulated by anti-NOTCH1 antibody treatment. Notch1 null tumors showed reduced proliferation. We conclude that Notch1 mutations in normal epithelium are beneficial as wild-type Notch1 favors tumor expansion. NOTCH1 blockade may have therapeutic potential in preventing esophageal squamous cancer.

Background Preoperative goals of care (GOC) and code status (CS) discussions are important in achieving an in-depth understanding of the patient's care goals in the setting of a serious illness, enabling the clinician to ensure patient autonomy and shared decision making. Past studies have shown that anesthesiologists are not formally trained in leading these discussions and may lack the necessary skill set. We created an innovative online video curriculum designed to teach these skills. This curriculum was compared to a traditional method of learning from reading the medical literature. Methods In this bi-institutional randomized controlled trial at 2 major academic medical centers, 60 anesthesiology trainees were randomized to receive the educational content in 1 of 2 formats: (1) the novel video curriculum (video group) or (2) journal articles (reading group). Thirty residents were assigned to the experimental video curriculum group, and 30 were assigned to the reading group. The content incorporated into the 2 formats focused on general preoperative evaluation of patients and communication strategies pertaining to GOC and CS discussions. Residents in both groups underwent a pre- and postintervention objective structured clinical examination (OSCE) with standardized patients. Both OSCEs were scored using the same 24-point rubric. Score changes between the 2 OSCEs were examined using linear regression, and interrater reliability was assessed using weighted Cohen's kappa. Results Residents receiving the video curriculum performed significantly better overall on the OSCE encounter, with a mean score of 4.19 compared to 3.79 in the reading group. The video curriculum group also demonstrated statistically significant increased scores on 8 of 24 rubric categories when compared to the reading group. Conclusions Our novel video curriculum led to significant increases in resident performance during simulated GOC discussions and modest increases during CS discussions. Further development and refinement of this curriculum are warranted.

Skin cancer risk varies substantially across the body, yet how this relates to the mutations found in normal skin is unknown. Here we mapped mutant clones in skin from high- and low-risk sites. The density of mutations varied by location. The prevalence of NOTCH1 and FAT1 mutations in forearm, trunk, and leg skin was similar to that in keratinocyte cancers. Most mutations were caused by ultraviolet light, but mutational signature analysis suggested differences in DNA-repair processes between sites. Eleven mutant genes were under positive selection, with TP53 preferentially selected in the head and FAT1 in the leg. Fine-scale mapping revealed 10% of clones had copy-number alterations. Analysis of hair follicles showed mutations in the upper follicle resembled adjacent skin, but the lower follicle was sparsely mutated. Normal skin is a dense patchwork of mutant clones arising from competitive selection that varies by location. Significance: Mapping mutant clones across the body reveals normal skin is a dense patchwork of mutant cells. The variation in cancer risk between sites substantially exceeds that in mutant clone density. More generally, mutant genes cannot be assigned as cancer drivers until their prevalence in normal tissue is known. See related commentary by De Dominici and DeGregori, p. 227. This article is highlighted in the In This Issue feature, p. 211

Effective methods for engaging clinicians in continuing education for learning-based practice improvement remain unknown.To determine whether a smartphone-based app using spaced education with retrieval practice is an effective method to increase evidence-based practice.A prospective, unblinded, single-center, crossover randomized clinical trial was conducted at a single academic medical center from January 6 to April 24, 2020. Vanderbilt University Medical Center clinicians prescribing intravenous fluids were invited to participate in this study.All clinicians received two 4-week education modules: 1 on prescribing intravenous fluids and 1 on prescribing opioid and nonopioid medications (counterbalancing measure), over a 12-week period. The order of delivery was randomized 1:1 such that 1 group received the fluid management module first, followed by the pain management module after a 4-week break, and the other group received the pain management module first, followed by the fluid management module after a 4-week break.The primary outcome was evidence-based clinician prescribing behavior concerning intravenous fluids in the inpatient setting and pain medication prescribing on discharge from the hospital.A total of 354 participants were enrolled and randomized, with 177 in group 1 (fluid then pain management education) and 177 in group 2 (pain management then fluid education). During the overall study period, 16 868 questions were sent to 349 learners, with 11 783 (70.0%) being opened: 10 885 (92.4%) of those opened were answered and 7175 (65.9%) of those answered were answered correctly. The differences between groups changed significantly over time, indicated by the significant interaction between educational intervention and time (P = .002). Briefly, at baseline evidence-concordant IV fluid ordered 7.2% less frequently in group 1 than group 2 (95% CI, -19.2% to 4.9%). This was reversed after training at 4% higher (95% CI, -8.2% to 16.0%) in group 1 than group 2, a more than doubling in the odds of evidence-concordant ordering (OR, 2.56, 95% CI, 0.80-8.21). Postintervention, all gains had been reversed with less frequent ordering in group 1 than group 2 (-9.5%, 95% CI, -21.6% to 2.7%). There was no measurable change in opioid prescribing behaviors at any time point.In this randomized clinical trial, use of smartphone app learning modules resulted in statistically significant short-term improvement in some prescribing behaviors. However, this effect was not sustained over the long-term. Additional research is needed to understand how to sustain improvements in care delivery as a result of continuous professional development at the institutional level.ClinicalTrials.gov Identifier: NCT03771482.

Repeated serosurveys are an important tool for understanding trends in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and vaccination. During 1 September 2020–20 March 2021, the NYC Health Department conducted a population-based SARS-CoV-2 antibody prevalence survey of 2096 NYC adults who either provided a blood specimen or self-reported the results of a previous antibody test. The serosurvey, the second in a series of surveys conducted by the NYC Health Department, aimed to estimate SARS-CoV-2 antibody prevalence across the city and for different groups at higher risk for adverse health outcomes. Weighted citywide prevalence was 23.5% overall (95% confidence interval (CI) 20.1–27.4) and increased from 19.2% (95% CI 14.7–24.6) before coronavirus disease 2019 vaccines were available to 31.3% (95% CI 24.5–39.0) during the early phases of vaccine roll-out. We found no differences in antibody prevalence by age, race/ethnicity, borough, education, marital status, sex, health insurance coverage, self-reported general health or neighbourhood poverty. These results show an overall increase in population-level seropositivity in NYC following the introduction of SARS-CoV-2 vaccines and highlight the importance of repeated serosurveys in understanding the pandemic's progression.

Epithelial stem cells accumulate mutations throughout life. Some of these mutants increase competitive fitness and may form clones that colonize the stem cell niche and persist to acquire further genome alterations. After a transient expansion, mutant stem cells must revert to homeostatic behavior so normal tissue architecture is maintained. Some positively selected mutants may promote cancer development, whereas others inhibit carcinogenesis. Factors that shape the mutational landscape include wild-type and mutant stem cell dynamics, competition for the niche, and environmental exposures. Understanding these processes may give new insight into the basis of cancer risk and opportunities for cancer prevention. Significance: Recent advances in sequencing have found somatic mutations in all epithelial tissues studied to date. Here we review how the mutational landscape of normal epithelia is shaped by clonal competition within the stem cell niche combined with environmental exposures. Some of the selected mutant genes are oncogenic, whereas others may be inhibitory of transformation. Discoveries in this area leave many open questions, such as the definition of cancer driver genes, the mechanisms by which tissues constrain a high proportion of oncogenic mutant cells, and whether clonal fitness can be modulated to decrease cancer risk.

Ongoing research seeks to identify blood-based biomarkers able to predict onset and progression of Alzheimer's disease (AD).The unfolded conformational variant of p53 (U-p53AZ), previously observed in AD individuals, was evaluated in plasma samples from individuals participating in the Australian Imaging, Biomarkers and Lifestyle (AIBL) cohort for diagnostic and prognostic assessment, validated on a neuropsychological-based diagnosis, over the course of six years.Retrospective Longitudinal Prognostic biomarker study.Single-center study based on the AIBL cohort.482 participants of the AIBL cohort, aged 60-85 years, without uncontrolled diabetes, vascular disease, severe depression or psychiatric illnesses.The AlzoSure® Predict test, consisting of immunoprecipitation (IP) followed by liquid chromatography (LC) tandem mass spectrometry (MS/MS), was performed to quantify the AZ 284® peptide as readout of U-p53AZ and compared with an independent neuropsychological diagnosis. The amyloid load via amyloid β-positron emission tomography (Aβ-PET) and supporting clinical information were included where possible.U-p53AZ diagnostic and prognostic performance was assessed in both time-independent and time-dependent (36, 72 and 90 months following initial sampling) analyses. Prognostic performance of Aβ-PET and survival analyses with different risk factors (gender, Aβ-PET and APOE ε4 allele status) were also performed. U-p53AZ differentiated neuropsychologically graded AD from non-AD samples, and its detection at intermediate/high levels precisely identified present and future symptomatic AD. In both time-independent and time-dependent prognostic analyses U-p53AZ achieved area under the curve (AUC)98%, significantly higher than Aβ-PET AUCs (between 84% and 93%, P respectively0.0001 and0.001). As single factor, U-p53AZ could clearly determine the risk of AD neuropsychological diagnosis over time (low versus intermediate/high U-p53AZ hazard ratio=2.99). Proportional hazards regression analysis identified U-p53AZ levels as a major independent predictor of AD onset.These findings support use of U-p53AZ as blood-based biomarker predicting whether individuals would reach neuropsychologically-defined AD within six years prior to AD diagnosis. Integration of U-p53AZ in screening processes could support refined participant stratification for interventional studies.

The Muller muscle-conjunctival resection is a common technique used to treat blepharoptosis, but there is variability with the target surgical resection and expected postoperative outcomes measured by marginal reflex distance-1 (MRD1). A Levator-Mullerectomy is a novel surgical approach described by Morris et al to incorporate the levator palpebrae superioris in the same incision as the classic Muller muscle-conjunctival resection in the treatment of blepharoptosis. This a retrospective study of patients who underwent Levator-Mullerectomy for ptosis repair showing the clinical outcomes based on MRD1. Statistical analysis was performed using analysis of variance and a nonparametric Kruskal-Wallis test. One hundred-twelve eyes of 83 patients (29 bilateral cases) with a mean age 64.6 years (7-92 years) were included. The types and prevalence of blepharoptosis were involutional (83%), neurogenic (8.0%), traumatic (3.6%), apraxia (2.7%), and congenital (2.7%). There was no significant difference in clinical outcome based on type of blepharoptosis (P = 0.7). Target resection lengths of 8 mm, 10 mm, and 12 mm were compared with postoperative MRD1 change. The mean change in MRD 1 between 8 mm and 10 mm was found to be statistically significant (P = 0.001 for both) but was not statistically significant for the 12 mm resection (P = 0.8). In patients with blepharoptosis and a positive response to 2.5% phenylephrine can benefit from Levator-Mullerectomy with either an 8 mm or 10 mm resection. This novel surgical approach allows surgeons to produce a more predictable and consistent clinical outcome.

DNA double-strand break (DSB) repair by homologous recombination is confined to the S and G

DNA double-strand break (DSB) repair by homologous recombination (HR) is thought to be restricted to the S- and G2- phases of the cell cycle in part due to 53BP1 antagonizing DNA end resection in G1-phase and non-cycling quiescent (G0) cells. Here, we show that LIN37, a component of the DREAM transcriptional repressor, functions in a 53BP1-independent manner to prevent DNA end resection and HR in G0 cells. Loss of LIN37 leads to the expression of HR proteins, including BRCA1, BRCA2, PALB2, and RAD51, and promotes DNA end resection in G0 cells even in the presence of 53BP1. In contrast to 53BP1-deficiency, DNA end resection in LIN37-deficient G0 cells depends on BRCA1 and leads to RAD51 filament formation and HR. LIN37 is not required to protect DNA ends in cycling cells at G1-phase. Thus, LIN37 regulates a novel 53BP1-independent cell phase-specific DNA end protection pathway that functions uniquely in quiescent cells.

Problem In an ideal learning health care system (LHS), clinicians learn from what they do and do what they learn, closing the evidence-to-practice gap. In operationalizing an LHS, great strides have been made in knowledge generation. Yet, considerable challenges remain to the broad uptake of identified best practices. To bridge the gap from generating actionable knowledge to applying that knowledge in clinical practice, and ultimately to improving outcomes, new information must be disseminated to and implemented by frontline clinicians. To date, the dissemination of this knowledge through traditional avenues has not achieved meaningful practice change quickly. Approach Vanderbilt University Medical Center (VUMC) developed QuizTime, a smartphone application learning platform, to provide a mechanism for embedding workplace-based clinician learning in the LHS. QuizTime leverages spaced education and retrieval-based practice to facilitate practice change. Beginning in January 2020, clinician-researchers and educators at VUMC designed a randomized, controlled trial to test whether the QuizTime learning system influenced clinician behavior in the context of recent evidence supporting the use of balanced crystalloids rather than saline for intravenous fluid management and new regulations around opioid prescribing. Outcomes Whether spaced education and retrieval-based practice influence clinician behavior and patient outcomes at the VUMC system level will be tested using the data currently being collected. Next steps These findings will inform future directions for developing and deploying learning approaches at scale in an LHS, with the goal of closing the evidence-to-practice gap.

To address the need for simple, safe, sensitive, and scalable SARS-CoV-2 tests, we validated and implemented a PCR test that uses a saliva collection kit use at home. Individuals self-collected 300 μl saliva in vials containing Darnell Rockefeller University Laboratory (DRUL) buffer and extracted RNA was assayed by RT-PCR (the DRUL saliva assay). The limit of detection was confirmed to be 1 viral copy/μl in 20 of 20 replicate extractions. Viral RNA was stable in DRUL buffer at room temperature up to seven days after sample collection, and safety studies demonstrated that DRUL buffer immediately inactivated virus at concentrations up to 2.75x106 PFU/ml. Results from SARS-CoV-2 positive nasopharyngeal (NP) swab samples collected in viral transport media and assayed with a standard FDA Emergency Use Authorization (EUA) test were highly correlated with samples placed in DRUL buffer. Direct comparison of results from 162 individuals tested by FDA EUA oropharyngeal (OP) or NP swabs with co-collected saliva samples identified four otherwise unidentified positive cases in DRUL buffer. Over six months, we collected 3,724 samples from individuals ranging from 3 months to 92 years of age. This included collecting weekly samples over 10 weeks from teachers, children, and parents from a pre-school program, which allowed its safe reopening while at-risk pods were quarantined. In sum, we validated a simple, sensitive, stable, and safe PCR-based test using a self-collected saliva sample as a valuable tool for clinical diagnosis and screening at workplaces and schools.

With the approach of respiratory virus season in the Northern Hemisphere, clinical microbiology and public health laboratories will need rapid diagnostic assays to distinguish severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from influenza virus and respiratory syncytial virus (RSV) infections for diagnosis and surveillance. In this study, the clinical performance of the Xpert Xpress SARS-CoV-2/Flu/RSV test (Cepheid, Sunnyvale, CA, USA) for nasopharyngeal swab specimens was evaluated in four centers: Johns Hopkins Medical Microbiology Laboratory, Northwell Health Laboratories, NYC Public Health Laboratory, and Los Angeles County/University of Southern California (LAC+USC) Medical Center., With the approach of respiratory virus season in the Northern Hemisphere, clinical microbiology and public health laboratories will need rapid diagnostic assays to distinguish severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from influenza virus and respiratory syncytial virus (RSV) infections for diagnosis and surveillance. In this study, the clinical performance of the Xpert Xpress SARS-CoV-2/Flu/RSV test (Cepheid, Sunnyvale, CA, USA) for nasopharyngeal swab specimens was evaluated in four centers: Johns Hopkins Medical Microbiology Laboratory, Northwell Health Laboratories, NYC Public Health Laboratory, and Los Angeles County/University of Southern California (LAC+USC) Medical Center. A total of 319 nasopharyngeal swab specimens, positive for SARS-CoV-2 (n = 75), influenza A virus (n = 65), influenza B virus (n = 50), or RSV (n = 38) or negative (n = 91) by the standard-of-care nucleic acid amplification tests at each site, were tested using the Cepheid panel test. The overall positive percent agreement for the SARS-CoV-2 target was 98.7% (n = 74/75), and the negative agreement was 100% (n = 91), with all other analytes showing 100% total agreement (n = 153). Standard-of-care tests to which the Cepheid panel was compared included the Cepheid Xpert Xpress SARS-CoV-2, Cepheid Xpert Xpress Flu/RSV, GenMark ePlex respiratory panel, BioFire respiratory panel 2.1 and v1.7, DiaSorin Simplexa COVID-19 Direct, and Hologic Panther Fusion SARS-CoV-2 assays. The Xpert Xpress SARS-CoV-2/Flu/RSV test showed high sensitivity and accuracy for all analytes included in the test. This test will provide a valuable clinical diagnostic and public health solution for detecting and differentiating SARS-CoV-2, influenza A and B virus, and RSV infections during the current respiratory virus season.

Despite continued efforts, recurrence after ventral hernia repair (VHR) remains a common problem. Biosynthetic PhasixAdult patients (≥ 18 years old) undergoing VHR with P4HB mesh between 10/2015 and 01/2018 by a single surgeon were retrospectively identified. Patients with 36 months of follow-up were excluded unless they had a documented recurrence. Clinical outcomes and quality of life using the Hernia-Related Quality of Life Survey (HerQLes) were assessed.Seventy-one patients were included with a median age and body mass index of 61.2 and 31 kg/mLongitudinal clinical and quality of life outcomes after clean and contaminated VHR with P4HB are limited. Here, we conclude that P4HB is an effective and versatile mesh option for use in abdominal wall reinforcement.

Next-generation sequencing technologies are being rapidly adopted as a tool of choice for diagnostic and outbreak investigation in public health laboratories. However, costs of operation and the need for specialized staff remain major hurdles for laboratories with limited resources for implementing these technologies. This project aimed to assess the feasibility of using Oxford Nanopore MinION whole-genome sequencing data of Mycobacterium tuberculosis isolates for species identification, in silico spoligotyping, detection of mutations associated with antimicrobial resistance (AMR) to accurately predict drug susceptibility profiles, and phylogenetic analysis to detect transmission between cases. The results were compared prospectively in real time to those obtained with our current clinically validated Illumina MiSeq sequencing assay for M. tuberculosis and phenotypic drug susceptibility testing results when available. Our assessment of 431 sequenced samples over a 32-week period demonstrates that, when using the proper quality controls and thresholds, the MinION can achieve levels of genotyping analysis and phenotypic resistance predictions comparable to those of the Illumina MiSeq at a very competitive cost per sample. Our results indicate that nanopore sequencing can be a suitable alternative to, or complement, currently used sequencing platforms in a clinical setting and has the potential to be widely adopted in public health laboratories in the near future.

Enterotoxigenic Escherichia coli (ETEC) is a well-established cause of traveller's diarrhoea and occasional domestic foodborne illness outbreaks in the USA. Although ETEC are not detected by conventional stool culture methods used in clinical laboratories, syndromic culture-independent diagnostic tests (CIDTs) capable of detecting ETEC have become increasingly prevalent in the last decade. This study describes the epidemiology of ETEC infections reported to the Minnesota Department of Health (MDH) during 2016–2017. ETEC-positive stool specimens were submitted to MDH to confirm the presence of ETEC DNA by polymerase chain reaction (PCR). Cases were interviewed to ascertain illness and exposures. Contemporaneous Salmonella cases were used as a comparison group in a case-case comparison analysis of risk factors. Of 222 ETEC-positive specimens received by MDH, 108 (49%) were concordant by PCR. ETEC was the sixth most frequently reported bacterial enteric pathogen among a subset of CIDT-positive specimens. Sixty-nine (64%) laboratory-confirmed cases had an additional pathogen codetected with ETEC, including enteroaggregative E. coli (n = 40) and enteropathogenic E. coli (n = 39). Although travel is a risk factor for ETEC infection, only 43% of cases travelled internationally, providing evidence for ETEC as an underestimated source of domestically acquired enteric illness in the USA.

Objectives To inform the design of a clinical trial of a targeted screening programme for relatives of individuals affected by thoracic aortic disease, we performed a consensus exercise as to the acceptability of screening, the optimal sequence and choice of tests, long-term patient management, and choice of trial design. Methods Working with the Aortic Dissection Awareness UK & Ireland patient association, we performed a Delphi exercise with clinical experts, patients, and carers, consisting of three rounds of consultation followed by a final multi-stakeholder face-to-face workshop. Results Thirty-five experts and 84 members of the public took part in the surveys, with 164 patients and clinicians attending the final workshop. There was substantial agreement on the need for a targeted screening pathway that would employ a combined approach (imaging + genetic testing). The target population would include the first- and second-degree adult (> 15 years) relatives, with no upper age limit of affected patients. Disagreement persisted about the screening process, sequence, personnel, the imaging method to adopt, computed tomography (CT) scan vs magnetic resonance imaging (MRI), and the specifics of a potential trial, including willingness to undergo randomisation, and measures of effectiveness and acceptability. Conclusion A Delphi process, initiated by patients, identified areas of uncertainty with respect to behaviour, process, and the design of a targeted screening programme for thoracic aortic disease that requires further research prior to any future trial.

Lower respiratory tract infections, including hospital-acquired and ventilator-associated pneumonia, are common in hospitalized patient populations. Standard methods frequently fail to identify the infectious etiology due to the polymicrobial nature of respiratory specimens and the necessity of ordering specific tests to identify viral agents. The potential severity of these infections combined with a failure to clearly identify the causative pathogen results in administration of empirical antibiotic agents based on clinical presentation and other risk factors., Lower respiratory tract infections, including hospital-acquired and ventilator-associated pneumonia, are common in hospitalized patient populations. Standard methods frequently fail to identify the infectious etiology due to the polymicrobial nature of respiratory specimens and the necessity of ordering specific tests to identify viral agents. The potential severity of these infections combined with a failure to clearly identify the causative pathogen results in administration of empirical antibiotic agents based on clinical presentation and other risk factors. We examined the impact of the multiplexed, semiquantitative BioFire FilmArray Pneumonia panel (PN panel) test on laboratory reporting for 259 adult inpatients submitting bronchoalveolar lavage (BAL) specimens for laboratory analysis. The PN panel demonstrated a combined 96.2% positive percent agreement (PPA) and 98.1% negative percent agreement (NPA) for the qualitative identification of 15 bacterial targets compared to routine bacterial culture. Semiquantitative values reported by the PN panel were frequently higher than values reported by culture, resulting in semiquantitative agreement (within the same log10 value) of 43.6% between the PN panel and culture; however, all bacterial targets reported as >105 CFU/ml in culture were reported as ≥105 genomic copies/ml by the PN panel. Viral targets were identified by the PN panel in 17.7% of specimens tested, of which 39.1% were detected in conjunction with a bacterial target. A review of patient medical records, including clinically prescribed antibiotics, revealed the potential for antibiotic adjustment in 70.7% of patients based on the PN panel result, including discontinuation or de-escalation in 48.2% of patients, resulting in an average savings of 6.2 antibiotic days/patient.

Nucleic acid amplification tests (NAATs) are the primary means of identifying acute infections caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Accurate and fast test results may permit more efficient use of protective and isolation resources and allow rapid therapeutic interventions. We evaluated the analytical and clinical performance characteristics of the Xpert Xpress SARS-CoV-2 (Xpert) test, a rapid, automated molecular test for SARS-CoV-2. Analytical sensitivity and specificity/interference were assessed with infectious SARS-CoV-2; other infectious coronavirus species, including SARS-CoV; and 85 nasopharyngeal swab specimens positive for other respiratory viruses, including endemic human coronaviruses (hCoVs)., Nucleic acid amplification tests (NAATs) are the primary means of identifying acute infections caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Accurate and fast test results may permit more efficient use of protective and isolation resources and allow rapid therapeutic interventions. We evaluated the analytical and clinical performance characteristics of the Xpert Xpress SARS-CoV-2 (Xpert) test, a rapid, automated molecular test for SARS-CoV-2. Analytical sensitivity and specificity/interference were assessed with infectious SARS-CoV-2; other infectious coronavirus species, including SARS-CoV; and 85 nasopharyngeal swab specimens positive for other respiratory viruses, including endemic human coronaviruses (hCoVs). Clinical performance was assessed using 483 remnant upper- and lower-respiratory-tract specimens previously analyzed by standard-of-care (SOC) NAATs. The limit of detection of the Xpert test was 0.01 PFU/ml. Other hCoVs, including Middle East respiratory syndrome coronavirus, were not detected by the Xpert test. SARS-CoV, a closely related species in the subgenus Sarbecovirus, was detected by a broad-range target (E) but was distinguished from SARS-CoV-2 (SARS-CoV-2-specific N2 target). Compared to SOC NAATs, the positive agreement of the Xpert test was 219/220 (99.5%), and the negative agreement was 250/261 (95.8%). A third tie-breaker NAAT resolved all but three of the discordant results in favor the Xpert test. The Xpert test provided sensitive and accurate detection of SARS-CoV-2 in a variety of upper- and lower-respiratory-tract specimens. The high sensitivity and short time to results of approximately 45 min may impact patient management.

BACKGROUND The Accreditation Council of Graduate Medical Education requires monitoring of resident clinical and educational hours but does not require tracking daily work patterns or duty hour equity. Lack of such monitoring may allow for inequity that affects resident morale. No defined system for resident relief of weekday operating room (OR) clinical duties existed at our institution, leaving on-call residents to independently decide daily relief order. We developed an automated decision support tool (DST) to improve equitable decision making for clinical relief and assessed its impact on real and perceived relief equity. METHODS The DST sent a daily e-mail to the senior resident responsible for relief decisions. It contained a prioritized relief list of noncall residents who worked in the OR beyond 5 PM the prior clinical day. We assessed actual relief equity using the number of times a resident worked in the OR past 5:30 PM on 2 consecutive weekdays as our outcome, adjusting for the mean number of open ORs each day between 5:00 PM and 6:59 PM in our main OR areas. We analyzed 14 months of data before implementation and 16 months of data after implementation. We assessed perceived relief equity before and after implementation using a questionnaire. RESULTS After implementing the DST, the percentage of residents held 2 consecutive weekdays over the total of resident days worked decreased from 1.33% to 0.43%. The percentage of residents held beyond 5:30 PM on any given day decreased from 18.09% to 12.64%. Segmented regression analysis indicated that implementation of the DST was associated with a reduction in biweekly time series of residents kept late 2 days in a row, independent of the mean number of ORs in use. Surveyed residents reported the DST aided their ability to make equitable relief decisions (pre 60% versus post 94%; P = .0003). Eighty-five percent of residents strongly agreed that a prioritized relief list based on prior day work hours after 5 PM aided their decision making. After implementation, residents reported fewer instances of working past 5 PM within the past month (P < .005). CONCLUSIONS A DST systematizing the relief process for anesthesiology residents was associated with a lower frequency of residents working beyond 5:30 PM in the OR on 2 consecutive days. The DST improved the perceived ability to make equitable relief decisions by on-call senior residents and residents being relieved. Success with this tool allows for broader applications in resident education, enabling enhanced monitoring of resident experiences and support for OR assignment decisions.

Optical coherence tomography angiography (OCT-A) provides rapid, flow-based imaging of the retinal and choroidal vasculature in a noninvasive manner. This review contrasts this novel technique with conventional angiography and discusses its current uses and limitations in the management of age-related macular degeneration (AMD).Initial work with OCT-A has focused on its ability to identify choriocapillaris flow alterations in dry AMD and to sensitively detect choroidal neovascular membranes (CNVs) in neovascular AMD. Reduced choriocapillaris flow beyond the borders of geographic atrophy seen on OCT-A suggests a primary vascular cause in geographic atrophy. Longitudinal OCT-A analysis of CNV morphology has demonstrated the transition from an immature to mature CNV phenotype following treatment. Current clinical applications of OCT-A include identification of asymptomatic CNV and monitoring for CNV development in the setting of an acquired vitelliform lesion.OCT-A remains a promising diagnostic tool but one still very much in evolution. Larger studies will be needed to more accurately describe its sensitivity and specificity for CNV detection and to better characterize longitudinal CNV morphologic changes. Anticipated hardware and software updates including swept-source light sources, automated montaging, and manual adjustment of interscan timing should enhance the capabilities of OCT-A in the management of AMD.

Nontyphoidal Salmonella enterica is a common cause of illness in humans ranging from gastroenteritis to invasive disease. National surveillance programs continually monitor trends in antimicrobial resistance patterns and mechanisms of resistance to identify emerging public health threats. Our study shows the emergence of nonsusceptibility to both levofloxacin and ceftriaxone, a concerning phenotype that threatens first-line antibiotic therapy, in Salmonella isolates recovered between 2014 and 2015. From 2010 to 2013 the rate of resistance increased from 0.0% (0/1181) to 1.5% (9/593) in 2014 and 2015. The isolates with this phenotype were found to be from multiple serotypes, including Typhimurium, Newport, and Enteritidis. Resistance to ceftriaxone was attributed to the presence of either an AmpC or extended-spectrum β-lactamase, and resistance to fluoroquinolones was attributable to the presence of mutations in the quinolone resistance-determining region or the presence of plasmid-mediated quinolone resistance genes. As this resistance pattern was seen in a variety of Salmonella serotypes harboring varied resistance mechanisms, it indicates a worrying trend in the spread of isolates resistant to both first-line treatment options.

Nasal and nasopharyngeal swab specimens tested by the Cepheid Xpert Xpress SARS-CoV-2 were analyzed by whole-genome sequencing based on impaired detection of the N2 target. Each viral genome had at least one mutation in the N gene, which likely arose independently in the New York City and Pittsburgh study sites.

Aims and objectives To examine international studies that specifically focus on transition to practice for graduate registered nurses in rural and remote areas. Background Supportive graduate nursing programmes are essential for enabling nursing graduates’ transition to practice and reducing attrition rates. Literature examining support measures for nursing graduates within metropolitan areas is abundant. However, there is a paucity of evidence on effective graduate programmes for rural and remote-based nursing graduates. Design A systematic approach was used to identify robust research within appropriate electronic databases. Method Eligible articles were critically reviewed using the Mixed Method Appraisal Tool critical appraisal tool. Eligible articles were thematically analysed using the Braun and Clark approach. Results Eight articles met the selection criteria for inclusion. Findings revealed that while most graduate nurses survived the transition process, they often felt overwhelmed and abandoned with intense feelings of frustration. Many suffered transition shock and did not feel ready for the role. Socialisation of graduates to the clinical environment was lacking. Support offered in many graduate programmes was ad hoc and unstructured. Senior staff were inadequately supported in their roles as preceptors to assist with the transition. Critical support measures recommended included both debrief sessions and regular one-on-one support. Conclusions Graduate programmes need to be structured yet flexible to accommodate the needs of rural and remote nurse graduates. Graduates need to be transitioned into practice with decremental support processes for both workloads and education. Preceptors require education on how to mentor before they can provide the appropriate support for graduates. Without these measures in place, a decrease in transition shock may not be possible. Relevance to clinical practice Graduate programmes need to be structured yet flexible, including assistance with both clinical skills and socialisation. Senior staff require education before they can adequately support new graduates.

We analyzed the effects of different cefepime MIC breakpoints on Enterobacteriaceae cefepime susceptibility and the presence of AmpC and extended-spectrum β-lactamase (ESBL) genes within the cefepime MIC interpretative categories.Using Enterobacteriaceae susceptibility data from 2013 comparisons of MIC breakpoints were performed using Pearson's chi-squared test. Molecular testing on a subset of isolates was done.Among 3784 non-duplicate clinical isolates, cefepime susceptibility decreased from 97.6% to 96.1% to 93.7% for CLSI 2013, CLSI 2014, and EUCAST 2011, respectively. In ceftriaxone non-susceptible isolates, cefepime susceptibility decreased from 79% to 66% (P0.0001) using CLSI 2013 and 2014, respectively, which was greater and statistically significant for Escherichia coli and Klebsiella spp. but not for Enterobacter spp. (P=0.06). Isolates with MIC ≤1μg/mL more often harbored AmpC (77%) than ESBL (18%) genes.Lower cefepime MIC breakpoints decrease cefepime susceptibility for isolates harboring ESBLs, while sparing the majority of those with AmpCs.

Increased expression of the c-jun transcription factor occurs in a variety of human neuropathies and is critical in promoting Schwann cell (SC) dedifferentiation and loss of the myelinated phenotype. Using cell culture models, we previously identified KU-32 as a novobiocin-based C-terminal heat shock protein 90 (Hsp90) inhibitor that decreased c-jun expression and the extent of demyelination. Additional chemical optimization has yielded KU-596 as a neuroprotective novologue whose mechanistic efficacy to improve a metabolic neuropathy requires the expression of Hsp70. The current study examined whether KU-596 therapy could decrease c-jun expression and improve motor function in an inducible transgenic model of a SC-specific demyelinating neuropathy (MPZ-Raf mice). Treating MPZ-Raf mice with tamoxifen activates the MAPK kinase pathway, increases c-jun expression and produces a profound demyelinating neuropathy characterized by a loss of motor function and paraparesis. KU-596 therapy did not interfere with MAPK activation but reduced c-jun expression, significantly improved motor performance, and ameliorated the extent of peripheral nerve demyelination in both prevention and intervention studies. Hsp70 was necessary for the drug’s neuroprotective efficacy since MPZ-Raf × Hsp70 knockout mice did not respond to KU-596 therapy. Collectively, our data indicate that modulating Hsp70 may provide a novel therapeutic approach to attenuate SC c-jun expression and ameliorate the onset of certain demyelinating neuropathies in humans.

The American Academy of Otolaryngology-Head and Neck Surgery Foundation has published a supplement to this issue of Otolaryngology-Head and Neck Surgery featuring the "Clinical Practice Guideline: Evaluation of the Neck Mass in Adults." To assist in implementing the guideline recommendations, this article summarizes the rationale, purpose, and key action statements. The 12 recommendations developed emphasize reducing delays in diagnosis of head and neck squamous cell carcinoma; promoting appropriate testing, including imaging, pathologic evaluation, and empiric medical therapies; reducing inappropriate testing; and promoting appropriate physical examination when cancer is suspected.

Objective Although duplex ultrasound (DUS) imaging is the current gold standard in the diagnosis of femoropopliteal deep venous thrombosis, it is not an optimal diagnostic modality to diagnose iliocaval occlusion. Screening for iliocaval occlusion thus remains a challenge for clinicians because of the lack of a reliable noninvasive technique. This challenge results in most patients undergoing computed tomography venography or magnetic resonance venography or invasive venography and intravascular ultrasound imaging. This study reports a novel, yet simple, reproducible and intuitive, surface DUS finding of physiologic flow reversal within the superficial epigastric vein (SEV) as a sign of proximal iliocaval occlusion (ICO). Methods This was a retrospective study of 15 patients who were diagnosed with ICO based on the finding of SEV flow reversal on DUS imaging. Patient demographics, presenting CEAP C scores, ICO characteristics, correlation with advanced imaging, and short-term follow-up findings are reported. Results Physiologic reversal of the SEV resulted in confirmation of ICO in all patients who underwent advanced imaging, including computed tomography venography or traditional venogram along with intravascular ultrasound imaging. All patients who underwent follow-up DUS scans demonstrated normalization of the SEV flow after ICO recanalization. Conclusions ICO can result in deep venous thrombosis, post-thrombotic syndrome, and chronic venous insufficiency. Physiologic flow reversal in SEV is diagnostic of ICO. To the best of our knowledge, this is the first report of this novel DUS finding.

The ability to provide timely identification of the causative agents of lower respiratory tract infections can promote better patient outcomes and support antimicrobial stewardship efforts. Current diagnostic testing options include culture, molecular testing, and antigen detection. These methods may require collection of various specimens, involve extensive sample treatment, and can suffer from low sensitivity and long turnaround times. This study assessed the performance of the BioFire FilmArray Pneumonia Panel (PN panel) and Pneumonia Plus Panel (PNplus panel), an FDA-cleared sample-to-answer assay that enables the detection of viruses, atypical bacteria, bacteria, and antimicrobial resistance marker genes from lower respiratory tract specimens (sputum and bronchoalveolar lavage [BAL] fluid)., The ability to provide timely identification of the causative agents of lower respiratory tract infections can promote better patient outcomes and support antimicrobial stewardship efforts. Current diagnostic testing options include culture, molecular testing, and antigen detection. These methods may require collection of various specimens, involve extensive sample treatment, and can suffer from low sensitivity and long turnaround times. This study assessed the performance of the BioFire FilmArray Pneumonia Panel (PN panel) and Pneumonia Plus Panel (PNplus panel), an FDA-cleared sample-to-answer assay that enables the detection of viruses, atypical bacteria, bacteria, and antimicrobial resistance marker genes from lower respiratory tract specimens (sputum and bronchoalveolar lavage [BAL] fluid). Semiquantitative results are also provided for the bacterial targets. This paper describes selected analytical and clinical studies that were conducted to evaluate performance of the panel for regulatory clearance. Prospectively collected respiratory specimens (846 BAL and 836 sputum specimens) evaluated with the PN panel were also tested by quantitative reference culture and molecular methods for comparison. The PN panel showed a sensitivity of 100% for 15/22 etiologic targets using BAL specimens and for 10/24 using sputum specimens. All other targets had sensitivities of ≥75% or were unable to be calculated due to low prevalence in the study population. Specificity for all targets was ≥87.2%, with many false-positive results compared to culture that were confirmed by alternative molecular methods. Appropriate adoption of this test could provide actionable diagnostic information that is anticipated to impact patient care and antimicrobial stewardship decisions.

The accumulation of brain amyloid β (Aβ) is one of the main pathological hallmarks of Alzheimer’s disease (AD). However, the role of brain amyloid deposition in the development of AD and the genetic variants associated with this process remain unclear. In this study, we sought to identify associations between Aβ deposition and an a priori evidence based set of 1610 genetic markers, genotyped from 505 unrelated individuals (258 Aβ+ and 247 Aβ−) enrolled in the Australian Imaging, Biomarker & Lifestyle (AIBL) study. We found statistically significant associations for 6 markers located within intronic regions of 6 genes, including AC103796.1-BDNF, PPP3R1, NGFR, KL, ABCA7 & CALHM1. Although functional studies are required to elucidate the role of these genes in the accumulation of Aβ and their potential implication in AD pathophysiology, our findings are consistent with results obtained in previous GWAS efforts.

Background Chronic venous disease (CVD) is a common vascular disorder with manifestations ranging from asymptomatic spider veins to venous ulcers. Elevated right atrial pressure, otherwise called central venous pressure (CVP), can also result in edema and hyperpigmentation similar to chronic venous insufficiency. Obstructive sleep apnea (OSA) is a known risk factor for elevation of CVP. Prevalence rates of elevated CVP or OSA are unknown in patients presenting with a diagnosis of CVD. Methods This is a single-center, retrospective, descriptive study of patients referred to our tertiary care center with a diagnosis of CVD. Each patient was evaluated by simultaneous venous duplex ultrasound (to assess venous reflux) and limited echocardiography of the right side of the heart (to assess elevated CVP). We assessed the prevalence and predictors of elevated CVP in this cohort using multivariate logistic regression. Results A total of 264 patients with CVD were evaluated, and of these, 22.7% had elevated CVP and 26.9% had OSA. There was no significant difference in the prevalence of OSA or elevated body mass index in the group with elevated CVP compared with patients with normal CVP. The predictors of elevated CVP were age >64.6 years (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.003-1.05; P = .026), diabetes mellitus (OR, 2.19; 95% CI, 1.05-4.5; P = .035), and right lower extremity Venous Clinical Severity Score of ≥8.5 (OR, 1.098; 95% CI, 1.011-1.193; P = .026). Other predictors included prior history of pulmonary embolism and renal insufficiency. Conclusions Compared with the general population, the prevalence of elevated CVP and OSA is significant in this cohort of patients. Age, diabetes, and right lower extremity chronic venous insufficiency symptoms seem to be predictors of elevated CVP. Larger, population-based prevalence studies are needed to confirm these findings.

Infantile globoid cell leukodystrophy (GLD, Krabbe disease) is a fatal demyelinating disorder caused by a deficiency in the lysosomal enzyme galactosylceramidase (GALC). GALC deficiency leads to the accumulation of the cytotoxic glycolipid, galactosylsphingosine (psychosine). Complementary evidence suggested that psychosine is synthesized via an anabolic pathway. Here, we show instead that psychosine is generated catabolically through the deacylation of galactosylceramide by acid ceramidase (ACDase). This reaction uncouples GALC deficiency from psychosine accumulation, allowing us to test the long-standing “psychosine hypothesis.” We demonstrate that genetic loss of ACDase activity (Farber disease) in the GALC-deficient mouse model of human GLD (twitcher) eliminates psychosine accumulation and cures GLD. These data suggest that ACDase could be a target for substrate reduction therapy (SRT) in Krabbe patients. We show that pharmacological inhibition of ACDase activity with carmofur significantly decreases psychosine accumulation in cells from a Krabbe patient and prolongs the life span of the twitcher (Twi) mouse. Previous SRT experiments in the Twi mouse utilized l-cycloserine, which inhibits an enzyme several steps upstream of psychosine synthesis, thus altering the balance of other important lipids. Drugs that directly inhibit ACDase may have a more acceptable safety profile due to their mechanistic proximity to psychosine biogenesis. In total, these data clarify our understanding of psychosine synthesis, confirm the long-held psychosine hypothesis, and provide the impetus to discover safe and effective inhibitors of ACDase to treat Krabbe disease.

Purpose In the lungs of cystic fibrosis patients, Pseudomonas aeruginosa is exposed to a myriad of antibiotics leading to alterations in antibiotic susceptibility. This study identifies mutations resulting in hypersusceptibility in isogenic mutants of a P. aeruginosa clinical isolate, PA34. Methods PA34 was exposed to subinhibitory concentrations of doripenem or meropenem during growth to mid‐log phase. Antibiotic susceptibility of surviving colonies was determined by agar dilution. Two carbapenem‐resistant colonies hypersusceptible to non‐carbapenem antibiotics were selected for further analysis. Antibiotic resistance gene expression was evaluated by RT‐rtPCR and OprD production by SDS‐PAGE. PA34 and isogenic mutants were evaluated with whole genome sequencing. Sequence variants were confirmed by Sanger sequencing, and cognate genes in eight carbapenem‐resistant clinical isolates hypersusceptible to non‐carbapenem antibiotics were sequenced. Lipopolysaccharide preparations of PA34 and hypersusceptible mutants were evaluated with ProQ‐Emerald stain. Results Isogenic mutants showed 4‐ to 8‐fold MIC increase for imipenem, meropenem, and doripenem. However, they were hypersusceptible (≥4‐fold MIC decrease) to aminoglycosides, fluoroquinolones, and non‐carbapenem β‐lactams. Expression of ampC or mex‐opr efflux pumps was unchanged, but OprD production was decreased. Mutations causing Q86H AlgU and G77C LptG amino acid substitutions and nonsense mutations within OprD were observed in both mutants. Lipopolysaccharide modifications were observed between isogenic mutants and PA34. Non‐synonymous mutations in LptF or LptG were observed in 6/8 hypersusceptible clinical isolates resistant to carbapenem antibiotics. Conclusion Evaluation of hypersusceptible mutants identified the association between lptG and a hypersusceptible phenotype. Modifications in lipopolysaccharide profiles suggests LptG modification interferes with lipopolysaccharide transport and contributes to hypersusceptibility., This study identifies mutations resulting in hypersusceptibility in isogenic mutants and clinical isolates of Pseudomonas aeruginosa. Mutations in the gene encoding the LptG subunit of the LptFG heterodimer were found to alter lipopolysaccharide (LPS) profiles in isogenic mutants. Modifications in LPS profiles suggest LptG modification interferes with LPS transport and contributes to hypersusceptibility.

STUDY OBJECTIVE: A challenge in reducing unwanted care variation is effectively managing the wide variety of performed surgical procedures. While an organization may perform thousands of types of cases, privacy and logistical constraints prevent review of previous cases to learn about prior practices. To bridge this gap, we developed a system for extracting key data from anesthesia records. Our objective was to determine whether usage of the system would improve case planning performance for anesthesia residents. DESIGN: Randomized, cross-over trial. SETTING: Vanderbilt University Medical Center MEASUREMENTS: We developed a web-based, data visualization tool for reviewing de-identified anesthesia records. First year anesthesia residents were recruited and performed simulated case planning tasks (e.g., selecting an anesthetic type) across six case scenarios using a randomized, cross-over design after a baseline assessment. An algorithm scored case planning performance based on care components selected by residents occurring frequently among prior anesthetics, which was scored on a 0–4 point scale. Linear mixed effects regression quantified the tool effect on the average performance score, adjusting for potential confounders. MAIN RESULTS: We analyzed 516 survey questionnaires from 19 residents. The mean performance score was 2.55 ± SD 0.32. Utilization of the tool was associated with an average score improvement of 0.120 points (95% CI 0.060 to 0.179; p < 0.001). Additionally, a 0.055 point improvement due to the “learning effect” was observed from each assessment to the next (95% CI 0.034 to 0.077; p < 0.001). Assessment score was also significantly associated with specific case scenarios (p < 0.001). CONCLUSIONS: This study demonstrated the feasibility of developing of a clinical data visualization system that aggregated key anesthetic information and found that the usage of tools modestly improved residents’ performance in simulated case planning.

The Anderson–May model of human parasite infections and specifically that for the intestinal worm Ascaris lumbricoides is reconsidered, with a view to deriving the observed characteristic negative binomial distribution which is frequently found in human communities. The means to obtaining this result lies in reformulating the continuous Anderson–May model as a stochastic process involving two essential populations, the density of mature worms in the gut, and the density of mature eggs in the environment. The resulting partial differential equation for the generating function of the joint probability distribution of eggs and worms can be partially solved in the appropriate limit where the worm lifetime is much greater than that of the mature eggs in the environment. Allowing for a mean field nonlinearity, and for egg immigration from neighbouring communities, a negative binomial worm distribution can be predicted, whose parameters are determined by those in the continuous Anderson–May model; this result assumes no variability in predisposition to the infection.\ud

Residency programs often struggle with strategies to formally teach leadership and communications skills. To provide a catalyst for professional development, Vanderbilt University Medical Center implemented a curriculum aimed at addressing this gap. Starting in 2014, the authors implemented a 2-week professional development rotation for first-year anesthesiology residents. Experts provided a series of didactic and experiential sessions focused on various professional development topics. Outcomes were assessed using pre- and postrotation surveys. Sixty-nine residents completed the rotation over a 4-year period, and 82% (54 of 66) strongly agreed that nonclinical professional development should be a component of training.

The mutational burden of aging As people age, they accumulate somatic mutations in healthy cells. About 25% of cells in normal, sun-exposed skin harbor cancer driver mutations. What about tissues not exposed to powerful mutagens like ultraviolet light? Martincorena et al. performed targeted gene sequencing of normal esophageal epithelium from nine human donors of varying age (see the Perspective by Chanock). The mutation rate was lower in esophagus than in skin, but there was a strong positive selection of clones carrying mutations in 14 cancer-associated genes. By middle age, more than half of the esophageal epithelium was colonized by mutant clones. Interestingly, mutations in the cancer driver gene NOTCH1 were more common in normal esophageal epithelium than in esophageal cancer. Science , this issue p. 911 ; see also p. 893

INTRODUCTION: Decisions regarding adjuvant chemotherapy in women with oestrogen receptor positive, human epidermal growth factor receptor 2 negative, node negative, early invasive breast cancer are unclear. The Recurrence Score(®) (RS) from Oncotype DX(®) (ODX) testing guides decisions based on individual cancer genomics. The aim of this study was to evaluate the impact of introducing ODX results on adjuvant treatment decisions and its potential economic benefits. METHODS: Patients offered the test were identified from the ODX requesting system. Information on reasons behind chemotherapy treatment decisions were collected from clinical letters and the pathology system. The Nottingham prognostic index (NPI) scores were calculated for each individual patient. RESULTS: A total of 101 patients were identified as having undergone ODX testing over 21 months. The median age was 57 years (range: 41–72 years), the median NPI was 3.70 (range: 3.40–5.26) and the median RS was 17 (range: 0–59). NPI did not predict the risk category. All of the patients in the high risk group, 35.1% in the intermediate risk group and 5.4% in the low risk group received chemotherapy. The majority of low risk patients who received chemotherapy made a decision prior to the ODX result. CONCLUSIONS: In our unit, RS aided our decision making regarding adjuvant chemotherapy. Patients with a higher RS were more likely to receive chemotherapy. If NPI had been used alone, more women would have been offered chemotherapy. Good communication with patients prior to testing is important to ensure it is cost effective.

Summary The access-repair-restore model for the role of chromatin in DNA repair infers that chromatin is a mere obstacle to DNA repair. However, here we show that blocking chromatin assembly, via knockdown of the histone chaperones ASF1 or CAF-1 or a mutation that prevents ASF1A binding to histones, hinders Rad51 loading onto ssDNA during homologous recombination. This is a consequence of reduced recruitment of the Rad51 loader MMS22L-TONSL to ssDNA, resulting in persistent RPA foci, extensive DNA end resection, persistent activation of the ATR-Chk1 pathway, and cell cycle arrest. In agreement, histones occupy ssDNA during DNA repair in yeast. We also uncovered DNA-PKcs-dependent DNA damage-induced ASF1A phosphorylation, which enhances chromatin assembly, promoting MMS22L-TONSL recruitment and, hence, Rad51 loading. We propose that transient assembly of newly synthesized histones onto ssDNA serves to recruit MMS22L-TONSL to efficiently form the Rad51 nucleofilament for strand invasion, suggesting an active role of chromatin assembly in homologous recombination.

Single stem cells, including those in human epidermis, have a remarkable ability to reconstitute tissues in vitro, but the cellular mechanisms that enable this are ill-defined. Here we used live imaging to track the outcome of thousands of divisions in clonal cultures of primary human epidermal keratinocytes. Two modes of proliferation were seen. In 'balanced' mode, similar proportions of proliferating and differentiating cells were generated, achieving the 'population asymmetry' that sustains epidermal homeostasis in vivo. In 'expanding' mode, an excess of cycling cells was produced, generating large expanding colonies. Cells in expanding mode switched their behaviour to balanced mode once local confluence was attained. However, when a confluent area was wounded in a scratch assay, cells near the scratch switched back to expanding mode until the defect was closed. We conclude that the ability of a single epidermal stem cell to reconstitute an epithelium is explained by two interconvertible modes of proliferation regulated by confluence.

Nanoparticles are increasingly being utilised in the innovation of consumer product formulations to improve their characteristics; however, established links between their properties, dose and cytotoxicity are not well defined. The purpose of this study was to screen four different nanomaterials of interest to oral care product development in the absence of stabilisers, alongside their respective bulk equivalents, within a non-keratinised oral epithelial cell model (H376). Particle morphology and size were characterised using scanning electron microscopy (SEM) and dynamic light scattering (DLS). The H376 model showed that zinc oxide (ZnO) was the most cytotoxic material at concentrations exceeding 0.031% w/v, as assessed using the lactate dehydrogenase (LDH) and dimethylthiazolyl-diphenyl-tetrazolium-bromide (MTT) assays. ZnO cytotoxicity does not appear to be dependent upon size of the particle; a result supported by SEM of cell-particle interactions. Differences in cytotoxicity were observed between the bulk and nanomaterial forms of hydroxyapatite and silica (SiO2); titanium dioxide (TiO2) was well tolerated in both forms at the doses tested. Overall, nano-size effects have some impact on the cytotoxicity of a material; however, these may not be as significant as chemical composition or surface properties. Our data highlights the complexities involved at the nano-scale, in both the characterisation of materials and in relation to cytotoxic properties exerted on oral epithelial cells.

Pseudomonas aeruginosa is a versatile opportunistic pathogen that causes chronic infections in immunocompromised hosts. Multiple porins modulate outer membrane permeability under various environmental conditions. The lung environment of cystic fibrosis (CF) patients is unique with changes occurring in nutrient availability, osmolarity, and oxygen content. Although P. aeruginosa gene expression is modified under these conditions, little is known about how they influence porin regulation. In this study, we evaluated the regulation of the outer membrane porin OpdQ, a member of the OprD family of porins, with regard to oxygen, nitrate, and/or NaCl levels. We demonstrated using promoter::fusion clones of P. aeruginosa PAO1 and clinical strains collected from CF patients that OpdQ was transcriptionally repressed under low oxygen but increased in the presence of nitrate. The nitrate‐induced regulation of OpdQ was found to be dependent on the transcription factor NarL via the NarXL two‐component system. In addition, NaCl‐induced osmotic stress increased OpdQ production among most of the clinical strains evaluated. In conclusion, these data identify for the first time that specific environmental cues associated with the CF microenvironment influence porin regulation, and that the nitrate‐induced regulation of OpdQ is associated with nitrate metabolism via the NarXL two‐component system of P. aeruginosa.

Summary Salmonella Typhi is the cause of typhoid fever, a major global health concern. An essential virulence factor of this pathogen is typhoid toxin. In contrast to most AB-type toxins, typhoid toxin is exclusively expressed by intracellular bacteria. The regulatory networks that ensure this unique gene expression pattern are unknown. Here, we developed FAST-INSeq, a genome-wide screening approach to identify S . Typhi genes required for typhoid toxin expression within infected cells. We find that typhoid toxin expression is controlled by a silencing and counter-silencing mechanism through the opposing actions of the PhoP/PhoQ two-component regulatory system and the histone-like protein H-NS. The screen also identified bacterial mutants that alter the proportion of intracellular S . Typhi that reside within an intravacuolar environment, which was essential for toxin expression. Collectively, these data describe a regulatory mechanism that allows a bacterial pathogen to exclusively express a virulence factor when located within a specific intracellular compartment.

Background Therapeutic mammaplasty, which combines breast reduction and mastopexy techniques with tumour excision, may extend the boundaries of breast-conserving surgery and improve outcomes for patients, but current practice is unknown and high-quality outcome data are lacking. This prospective multicentre cohort study aimed to explore the practice and short-term outcomes of the technique. Methods Consecutive patients undergoing therapeutic mammaplasty at participating centres between 1 September 2016 and 30 June 2017 were recruited to the study. Demographic, preoperative, operative, oncological and complication data were collected. The primary outcome was unplanned reoperation for complications within 30 days of surgery. Secondary outcomes included re-excision rates and time to adjuvant therapy. Results Overall, 880 patients underwent 899 therapeutic mammaplasty procedures at 50 centres. The most common indications were avoidance of poor cosmetic outcomes associated with standard breast-conserving surgery (702 procedures, 78·1 per cent) or avoidance of mastectomy (379, 42·2 per cent). Wise-pattern skin incisions were the most common (429 of 899, 47·7 per cent), but a range of incisions and nipple–areola pedicles were used. Immediate contralateral symmetrization was performed in one-third of cases (284 of 880, 32·3 per cent). In total, 205 patients (23·3 per cent) developed a complication, but only 25 (2·8 per cent) required reoperation. Median postoperative lesion size was 24·5 (i.q.r. 16–38) mm. Incomplete excision was seen in 132 procedures (14·7 per cent), but completion mastectomy was required for only 51 lesions (5·7 per cent). Median time to adjuvant therapy was 54 (i.q.r. 42–66) days. Conclusion Therapeutic mammaplasty is a safe and effective alternative to mastectomy or standard breast-conserving surgery. Further work is required to explore the impact of the technique on quality of life, and to establish cost-effectiveness.

Objective Neck masses are common in adults, but often the underlying etiology is not easily identifiable. While infections cause most of the neck masses in children, most persistent neck masses in adults are neoplasms. Malignant neoplasms far exceed any other etiology of adult neck mass. Importantly, an asymptomatic neck mass may be the initial or only clinically apparent manifestation of head and neck cancer, such as squamous cell carcinoma (HNSCC), lymphoma, thyroid, or salivary gland cancer. Evidence suggests that a neck mass in the adult patient should be considered malignant until proven otherwise. Timely diagnosis of a neck mass due to metastatic HNSCC is paramount because delayed diagnosis directly affects tumor stage and worsens prognosis. Unfortunately, despite substantial advances in testing modalities over the last few decades, diagnostic delays are common. Currently, there is only 1 evidence-based clinical practice guideline to assist clinicians in evaluating an adult with a neck mass. Additionally, much of the available information is fragmented, disorganized, or focused on specific etiologies. In addition, although there is literature related to the diagnostic accuracy of individual tests, there is little guidance about rational sequencing of tests in the course of clinical care. This guideline strives to bring a coherent, evidence-based, multidisciplinary perspective to the evaluation of the neck mass with the intention to facilitate prompt diagnosis and enhance patient outcomes. Purpose The primary purpose of this guideline is to promote the efficient, effective, and accurate diagnostic workup of neck masses to ensure that adults with potentially malignant disease receive prompt diagnosis and intervention to optimize outcomes. Specific goals include reducing delays in diagnosis of HNSCC; promoting appropriate testing, including imaging, pathologic evaluation, and empiric medical therapies; reducing inappropriate testing; and promoting appropriate physical examination when cancer is suspected. The target patient for this guideline is anyone ≥18 years old with a neck mass. The target clinician for this guideline is anyone who may be the first clinician whom a patient with a neck mass encounters. This includes clinicians in primary care, dentistry, and emergency medicine, as well as pathologists and radiologists who have a role in diagnosing neck masses. This guideline does not apply to children. This guideline addresses the initial broad differential diagnosis of a neck mass in an adult. However, the intention is only to assist the clinician with a basic understanding of the broad array of possible entities. The intention is not to direct management of a neck mass known to originate from thyroid, salivary gland, mandibular, or dental pathology as management recommendations for these etiologies already exist. This guideline also does not address the subsequent management of specific pathologic entities, as treatment recommendations for benign and malignant neck masses can be found elsewhere. Instead, this guideline is restricted to addressing the appropriate work-up of an adult patient with a neck mass that may be malignant in order to expedite diagnosis and referral to a head and neck cancer specialist. The Guideline Development Group sought to craft a set of actionable statements relevant to diagnostic decisions made by a clinician in the workup of an adult patient with a neck mass. Furthermore, where possible, the Guideline Development Group incorporated evidence to promote high-quality and cost-effective care. Action Statements The development group made a strong recommendation that clinicians should order a neck computed tomography (or magnetic resonance imaging) with contrast for patients with a neck mass deemed at increased risk for malignancy. The development group made the following recommendations: (1) Clinicians should identify patients with a neck mass who are at increased risk for malignancy because the patient lacks a history of infectious etiology and the mass has been present for ≥2 weeks without significant fluctuation or the mass is of uncertain duration. (2) Clinicians should identify patients with a neck mass who are at increased risk for malignancy based on ≥1 of these physical examination characteristics: fixation to adjacent tissues, firm consistency, size1.5 cm, or ulceration of overlying skin. (3) Clinicians should conduct an initial history and physical examination for patients with a neck mass to identify those with other suspicious findings that represent an increased risk for malignancy. (4) For patients with a neck mass who are not at increased risk for malignancy, clinicians or their designees should advise patients of criteria that would trigger the need for additional evaluation. Clinicians or their designees should also document a plan for follow-up to assess resolution or final diagnosis. (5) For patients with a neck mass who are deemed at increased risk for malignancy, clinicians or their designees should explain to the patient the significance of being at increased risk and explain any recommended diagnostic tests. (6) Clinicians should perform, or refer the patient to a clinician who can perform, a targeted physical examination (including visualizing the mucosa of the larynx, base of tongue, and pharynx) for patients with a neck mass deemed at increased risk for malignancy. (7) Clinicians should perform fine-needle aspiration (FNA) instead of open biopsy, or refer the patient to someone who can perform FNA, for patients with a neck mass deemed at increased risk for malignancy when the diagnosis of the neck mass remains uncertain. (8) For patients with a neck mass deemed at increased risk for malignancy, clinicians should continue evaluation of patients with a cystic neck mass, as determined by FNA or imaging studies, until a diagnosis is obtained and should not assume that the mass is benign. (9) Clinicians should obtain additional ancillary tests based on the patient's history and physical examination when a patient with a neck mass is deemed at increased risk for malignancy who does not have a diagnosis after FNA and imaging. (10) Clinicians should recommend evaluation of the upper aerodigestive tract under anesthesia, before open biopsy, for patients with a neck mass deemed at increased risk for malignancy and without a diagnosis or primary site identified with FNA, imaging, and/or ancillary tests. The development group recommended against clinicians routinely prescribing antibiotic therapy for patients with a neck mass unless there are signs and symptoms of bacterial infection.