bBacteria use a chemical communication process called quorum sensing to control transitions between individual and group behaviors. In the Vibrio harveyi quorum-sensing circuit, two master transcription factors, AphA and LuxR, coordinate the quorum-sensing response. Here we show that AphA regulates 167 genes, LuxR regulates 625 genes, and they coregulate 77 genes. LuxR strongly controls genes at both low cell density and high cell density, suggesting that it is the major quorum-sensing regulator. In contrast, AphA is absent at high cell density and acts to fine-tune quorum-sensing gene expression at low cell density. We examined two loci as case studies of coregulation by AphA and LuxR. First, AphA and LuxR directly regulate expression of the genes encoding the quorum-regulatory small RNAs Qrr2, Qrr3, and Qrr4, the consequence of which is a specifically timed transition between the individual and the group life-styles. Second, AphA and LuxR repress type III secretion system genes but at different times and to different extents. The consequence of this regulation is that type III secretion is restricted to a peak at midcell density. Thus, the asymmetric production of AphA and LuxR coupled with differences in their strengths and timing of target gene regulation generate a precise temporal pattern of gene expression.

SummaryBackgroundAlternate‐day‐fasting (ADF) has been proposed as an effective dieting method. Studies have found that it also can increase life span in rodents, and reduce inflammation in humans. The aim of this paper was to systematically review the efficacy of ADF compared to very‐low‐calorie dieting (VLCD) in terms of weight loss, and reduction of fat mass and fat‐free mass.Methods Systematic review: PubMed literature searches were performed. Fixed review procedures were applied. Studies were evaluated for quality. Twenty‐eight studies were included. Meta‐analysis: 10/28 studies (four ADF and six matched VLCD) were further analyzed.ResultsAfter adjustment for BMI and duration, there was no significant difference in mean body weight loss (VLCD 0.88 kg more weight loss than ADF, 95% CI: −4.32, 2.56) or fat‐free mass (VLCD 1.69 kg more fat‐free mass loss than ADF, 95% CI: −3.62, 0.23); there was a significant difference observed in fat mass (ADF 3.31 kg more fat mass loss than VLCD, 95% CI: 0.05, 6.56). Meta‐analysis showed that, among ADF studies, the pooled change in body weight, fat mass and fat‐free mass was 4.30 kg (95% CI: 3.41, 5.20), 4.06 kg (95% CI: 2.99, 5.13) and 0.72 kg (95% CI: −0.07, 1.51), respectively, while among VLCD studies, the pooled change was 6.28 kg (95% CI: 6.08, 6.49), 4.22 kg (95% CI: 3.95, 4.50) and 2.24 kg (95% CI: 1.95, 2.52), respectively.ConclusionsOur results from both the systematic review and the meta‐analysis suggest that ADF is an efficacious dietary method, and may be superior to VLCD for some patients because of ease of compliance, greater fat‐mass loss and relative preservation of fat‐free mass. Head‐to‐head randomized clinical trials are needed to further assess relative efficacy of these two approaches.

Timing of surgery is an important factor to consider when planning vault remodeling in syndromic craniosynostosis. Based on our institution's experience, when there is no concern for elevated intracranial pressure the ideal operative window for these procedures in the syndromic population appears to be 6 to 9 months of age.

Background The purpose of this study was to define patterns of injury and treatment for condylar and subcondylar fractures and evaluate short-term outcomes in the pediatric population. Methods A retrospective chart review was performed on pediatric patients with mandibular condylar fractures who presented between 1990 and 2010. Computed tomographic imaging was reviewed for all patients to assess fracture characteristics. Mandibular fractures were codified using the Strasbourg Osteosynthesis Research Group and Lindahl classification methods. Results Sixty-four patients with 92 condylar fractures were identified. Of these patients, 29 had isolated condylar fracture and 35 had a condylar fracture associated with an additional mandibular arch fracture. The most common fracture patterns were diacapitular fracture in the Strasbourg Osteosynthesis Research Group system (n = 46) and vertical condylar head fracture in the Lindahl system (n = 14). Condylar fracture with additional mandibular arch fractures were treated with maxillomandibular fixation more often than patients with condylar fracture [n = 40 (74.1 percent) versus n = 14 (25.9 percent); p = 0.004]. No condylar fracture was treated in an open fashion. Forty-three patients returned for follow-up. The median follow-up period was 81 days (interquartile range, 35 to 294 days). Ten patients had complications (23.3 percent). The most common complication was malocclusion (n = 5). Nine of 10 patients with complications had condylar fracture with an additional mandibular arch fracture. Conclusions Closed treatment of condylar fractures yields satisfactory results in pediatric patients. Pediatric patients with condylar fractures combined with additional arch fractures experience a higher rate of unfavorable outcomes.

OBJECTIVE Due to the changing properties of the infant skull, there is still no clear consensus on the ideal time to surgically intervene in cases of nonsyndromic craniosynostosis (NSC). This study aims to shed light on how patient age at the time of surgery may affect surgical outcomes and the subsequent need for reoperation. METHODS A retrospective cohort review was conducted for patients with NSC who underwent primary cranial vault remodeling between 1990 and 2013. Patients' demographic and clinical characteristics and surgical interventions were recorded. Postoperative outcomes were assessed by assigning each procedure to a Whitaker category. Multivariate logistic regression analysis was performed to determine the relationship between age at surgery and need for minor (Whitaker I or II) versus major (Whitaker III or IV) reoperation. Odds ratios (ORs) for Whitaker category by age at surgery were assigned. RESULTS A total of 413 unique patients underwent cranial vault remodeling procedures for NSC during the study period. Multivariate logistic regression demonstrated increased odds of requiring major surgical revisions (Whitaker III or IV) in patients younger than 6 months of age (OR 2.49, 95% CI 1.05–5.93), and increased odds of requiring minimal surgical revisions (Whitaker I or II) in patients older than 6 months of age (OR 2.72, 95% CI 1.16–6.41). CONCLUSIONS Timing, as a proxy for the changing properties of the infant skull, is an important factor to consider when planning vault reconstruction in NSC. The data presented in this study demonstrate that patients operated on before 6 months of age had increased odds of requiring major surgical revisions.

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SBNETs are frequently multifocal and most commonly located within 100 cm of the ICV. SBNETs are less prevalent proximally in the small bowel, which may result from anatomic differences in enterochromaffin cell density, hormonal factors, or environmental exposures in the distal SB.

To support the global restart of elective surgery, data from an international prospective cohort study of 8492 patients (69 countries) was analysed using artificial intelligence (machine learning techniques) to develop a predictive score for mortality in surgical patients with SARS-CoV-2. We found that patient rather than operation factors were the best predictors and used these to create the COVIDsurg Mortality Score (https://covidsurgrisk.app). Our data demonstrates that it is safe to restart a wide range of surgical services for selected patients.