Design and conduct of a randomized controlled feeding trial in a residential setting with mitigation for COVID-19.

BACKGROUND: Evaluating effects of different macronutrient diets in randomized trials requires well defined infrastructure and rigorous methods to ensure intervention fidelity and adherence. METHODS: This controlled feeding study comprised two phases. During a Run-in phase (14-15 weeks), study participants (18-50 years, BMI, ≥27 kg/m2) consumed a very-low-carbohydrate (VLC) diet, with home delivery of prepared meals, at an energy level to promote 15 ± 3% weight loss. During a Residential phase (13 weeks), participants resided at a conference center. They received a eucaloric VLC diet for three weeks and then were randomized to isocaloric test diets for 10 weeks: VLC (5% energy from carbohydrate, 77% from fat), high-carbohydrate (HC)-Starch (57%, 25%; including 20% energy from refined grains), or HC-Sugar (57%, 25%; including 20% sugar). Outcomes included measures of body composition and energy expenditure, chronic disease risk factors, and variables pertaining to physiological mechanisms. Six cores provided infrastructure for implementing standardized protocols: Recruitment, Diet and Meal Production, Participant Support, Assessments, Regulatory Affairs and Data Management, and Statistics. The first participants were enrolled in May 2018. Participants residing at the conference center at the start of the COVID-19 pandemic completed the study, with each core implementing mitigation plans. RESULTS: Before early shutdown, 77 participants were randomized, and 70 completed the trial (65% of planned completion). Process measures indicated integrity to protocols for weighing menu items, within narrow tolerance limits, and participant adherence, assessed by direct observation and continuous glucose monitoring. CONCLUSION: Available data will inform future research, albeit with less statistical power than originally planned.

Sall4 regulates posterior trunk mesoderm development by promoting mesodermal gene expression and repressing neural genes in the mesoderm.

The trunk axial skeleton develops from paraxial mesoderm cells. Our recent study demonstrated that conditional knockout of the stem cell factor Sall4 in mice by TCre caused tail truncation and a disorganized axial skeleton posterior to the lumbar level. Based on this phenotype, we hypothesized that, in addition to the previously reported role of Sall4 in neuromesodermal progenitors, Sall4 is involved in the development of the paraxial mesoderm tissue. Analysis of gene expression and SALL4 binding suggests that Sall4 directly or indirectly regulates genes involved in presomitic mesoderm differentiation, somite formation and somite differentiation. Furthermore, ATAC-seq in TCre; Sall4 mutant posterior trunk mesoderm shows that Sall4 knockout reduces chromatin accessibility. We found that Sall4-dependent open chromatin status drives activation and repression of WNT signaling activators and repressors, respectively, to promote WNT signaling. Moreover, footprinting analysis of ATAC-seq data suggests that Sall4-dependent chromatin accessibility facilitates CTCF binding, which contributes to the repression of neural genes within the mesoderm. This study unveils multiple mechanisms by which Sall4 regulates paraxial mesoderm development by directing activation of mesodermal genes and repression of neural genes.

American Radium Society Appropriate Use Criteria Postmastectomy Radiation Therapy: Executive Summary of Clinical Topics.

PURPOSE: To conduct an appropriate use criteria expert panel update on clinical topics relevant to current clinical practice regarding postmastectomy radiation therapy (PMRT). METHODS AND MATERIALS: An analysis of the medical literature from peer-reviewed journals was conducted from May 4, 2010 to May 4, 2022 using the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines to search the PubMed database to retrieve a comprehensive set of relevant articles. A well-established methodology (modified Delphi) was used by the expert panel to rate the appropriate use of procedures. RESULTS: Evidence for key questions in PMRT regarding benefit in special populations and technical considerations for delivery was examined and described. Risk factors for local-regional recurrence in patients with intermediate-risk disease that indicate benefit of PMRT include molecular subtype, age, clinical stage, and pathologic response to neoadjuvant chemotherapy. Use of hypofractionated radiation in PMRT has been examined in several recent randomized trials and is under investigation for patients with breast reconstruction. The use of bolus varies significantly by practice region and has limited evidence for routine use. Adverse effects occurred with both PMRT preimplant and postimplant exchange in 2-staged breast reconstruction. CONCLUSIONS: Most patients with even limited nodal involvement will likely benefit from PMRT with significant reduction in local-regional recurrence and potential survival. Patients with initial clinical stage III disease and/or any residual disease after neoadjuvant chemotherapy should be strongly considered for PMRT. Growing evidence supports the use of hypofractionated radiation for PMRT with equivalent efficacy and decreased acute side effects, but additional evidence is needed for special populations. There is limited evidence to support routine use of bolus in all patients. Timing of PMRT regarding completion of 2-staged breast reconstruction requires a discussion of increased risks with radiation postimplant exchange compared with increased risk of failure of reconstruction or surgical complications with radiation preimplant exchange.

Looking Back: International Practice Patterns in Breast Radiation Oncology From a Case-Based Survey Across 54 Countries During the First Surge of the COVID-19 Pandemic.

PURPOSE: The COVID-19 pandemic has profoundly affected cancer care worldwide, including radiation therapy (RT) for breast cancer (BC), because of risk-based resource allocation. We report the evolution of international breast RT practices during the beginning of the pandemic, focusing on differences in treatment recommendations between countries. MATERIALS AND METHODS: Between July and November 2020, a 58-question survey was distributed to radiation oncologists (ROs) through international professional societies. Changes in RT decision making during the first surge of the pandemic were evaluated across six hypothetical scenarios, including the management of ductal carcinoma in situ (DCIS), early-stage, locally advanced, and metastatic BC. The significance of changes in responses before and during the pandemic was examined using chi-square and McNemar-Bowker tests. RESULTS: One thousand one hundred three ROs from 54 countries completed the survey. Incomplete responses (254) were excluded from the analysis. Most respondents were from the United States (285), Japan (117), Italy (63), Canada (58), and Brazil (56). Twenty-one percent (230) of respondents reported treating at least one patient with BC who was COVID-19-positive. Approximately 60% of respondents reported no change in treatment recommendation during the pandemic, except for patients with metastatic disease, for which 57.7% (636/1,103; P < .0005) changed their palliative practice. Among respondents who noted a change in their recommendation during the first surge of the pandemic, omitting, delaying, and adopting short-course RT were the most frequent changes, with most transitioning to moderate hypofractionation for DCIS and early-stage BC. CONCLUSION: Early in the COVID-19 pandemic, significant changes in global RT practice patterns for BC were introduced. The impact of published results from the FAST FORWARD trial supporting ultrahypofractionation likely confounded the interpretation of the pandemic's independent influence on RT delivery.

The effects of an e-health brisk walking intervention in increasing moderate-to-vigorous physical activity in physically inactive older people with cognitive frailty: study protocol for a randomized controlled trial.

BACKGROUND: Cognitive frailty is a risk for many adverse health outcomes that are commonly observed in older people. Physical activity is known to be effective to reserve cognitive frailty but the prevalence of physical inactivity is still high in older people. E-health enhances behavioural change effects through an innovative way to deliver behavioural change methods that can enhance the behavioural change effects. However, its effects on older people with cognitive frailty, its effects compared with conventional behavioural change methods, and the sustainability of the effects are unclear. METHODS: This study employs a single-blinded, two-parallel-group, non-inferiority, randomized controlled trial design with a 1:1 group allocation ratio. Eligible participants are aged 60 years or above, have cognitive frailty and physical inactivity, and possess a smartphone for more than six months. The study will be conducted in community settings. In the intervention group, participants will receive a 2-week brisk-walking training followed by a 12-week e-health intervention. In the control group, participants will receive a 2-week brisk-walking training followed by a 12-week conventional behavioural change intervention. The primary outcome is minutes of moderate-to-vigorous physical activity (MVPA). This study aims to recruit a total of 184 participants. Generalized estimating equations (GEE) will be used to examine the effects of the intervention. ETHICS AND DISSEMINATION: The trial has been registered at ClinicalTrials.gov (Identifier: NCT05758740) on 7th March 2023, https://clinicaltrials.gov/ct2/show/NCT05758740 , and all items come from the World Health Organization Trial Registration Data Set. It has been approved by the Research Ethics Committee of Tung Wah College, Hong Kong (reference number: REC2022136). The findings will be disseminated in peer-reviewed journals and presented at international conferences relevant to the subject fields. TRIAL REGISTRATION: The trial has been registered at ClinicalTrials.gov (Identifier: NCT05758740) and all items come from the World Health Organization Trial Registration Data Set. The latest version of the protocol was published online on 7th March 2023.

Monitoring body composition change for intervention studies with advancing 3D optical imaging technology in comparison to dual-energy X-ray absorptiometry.

BACKGROUND: Recent 3-dimensional optical (3DO) imaging advancements have provided more accessible, affordable, and self-operating opportunities for assessing body composition. 3DO is accurate and precise in clinical measures made by DXA. However, the sensitivity for monitoring body composition change over time with 3DO body shape imaging is unknown. OBJECTIVES: This study aimed to evaluate the ability of 3DO in monitoring body composition changes across multiple intervention studies. METHODS: A retrospective analysis was performed using intervention studies on healthy adults that were complimentary to the cross-sectional study, Shape Up! Adults. Each participant received a DXA (Hologic Discovery/A system) and 3DO (Fit3D ProScanner) scan at the baseline and follow-up. 3DO meshes were digitally registered and reposed using Meshcapade to standardize the vertices and pose. Using an established statistical shape model, each 3DO mesh was transformed into principal components, which were used to predict whole-body and regional body composition values using published equations. Body composition changes (follow-up minus the baseline) were compared with those of DXA using a linear regression analysis. RESULTS: The analysis included 133 participants (45 females) in 6 studies. The mean (SD) length of follow-up was 13 (5) wk (range: 3-23 wk). Agreement between 3DO and DXA (R2) for changes in total FM, total FFM, and appendicular lean mass were 0.86, 0.73, and 0.70, with root mean squared errors (RMSEs) of 1.98 kg, 1.58 kg, and 0.37 kg, in females and 0.75, 0.75, and 0.52 with RMSEs of 2.31 kg, 1.77 kg, and 0.52 kg, in males, respectively. Further adjustment with demographic descriptors improved the 3DO change agreement to changes observed with DXA. CONCLUSIONS: Compared with DXA, 3DO was highly sensitive in detecting body shape changes over time. The 3DO method was sensitive enough to detect even small changes in body composition during intervention studies. The safety and accessibility of 3DO allows users to self-monitor on a frequent basis throughout interventions. This trial was registered at clinicaltrials.gov as NCT03637855 (Shape Up! Adults; https://clinicaltrials.gov/ct2/show/NCT03637855); NCT03394664 (Macronutrients and Body Fat Accumulation: A Mechanistic Feeding Study; https://clinicaltrials.gov/ct2/show/NCT03394664); NCT03771417 (Resistance Exercise and Low-Intensity Physical Activity Breaks in Sedentary Time to Improve Muscle and Cardiometabolic Health; https://clinicaltrials.gov/ct2/show/NCT03771417); NCT03393195 (Time Restricted Eating on Weight Loss; https://clinicaltrials.gov/ct2/show/NCT03393195), and NCT04120363 (Trial of Testosterone Undecanoate for Optimizing Performance During Military Operations; https://clinicaltrials.gov/ct2/show/NCT04120363).

Are methods of estimating fat-free mass loss with energy-restricted diets accurate?

BACKGROUND/OBJECTIVES: Fat-free mass (FFM) often serves as a body composition outcome variable in weight loss studies. An important assumption is that the proportions of components that make up FFM remain stable following weight loss; some body composition models rely on these "constants". This exploratory study examined key FFM component proportions before and following weight loss in two studies of participants with overweight and obesity. SUBJECTS/METHODS: 201 men and women consumed calorie-restricted moderate- or very-low carbohydrate diets leading to 10-18% weight loss in 9-15 weeks. Measured total body fat, lean mass, bone mineral, total body water (TBW), and body weight at baseline and follow-up were used to derive FFM and its chemical proportions using a four-component model. RESULTS: A consistent finding in both studies was a non-significant reduction in bone mineral and a corresponding increase (p < 0.001) in bone mineral/FFM; FFM density increased significantly in one group of women and in all four participant groups combined (both, p < 0.05). FFM hydration (TBW/FFM) increased in all groups of men and women, one significantly (p < 0.01), and in the combined sample (borderline, p < 0.10). The proportion of FFM as protein decreased across all groups, two significantly (p < 0.05-0.01) and in the combined sample (p < 0.05). CONCLUSION: FFM relative proportions of chemical components may not be identical before and after short-term weight loss, an observation impacting some widely used body composition models and methods. Caution is thus needed when applying FFM as a safety signal or to index metabolic evaluations in clinical trials when these body composition approaches are used.

Clinicopathologic Features, Treatment Patterns, and Disease Outcomes in a Modern, Prospective Cohort of Young Women Diagnosed with Ductal Carcinoma In Situ.

BACKGROUND: Ductal carcinoma in situ (DCIS) is uncommon and understudied in young women. The objective of this study is to describe clinicopathologic features, treatment, and oncologic outcomes in a modern cohort of women aged ≤ 40 years with DCIS. PATIENTS AND METHODS: Patients with DCIS were identified from the Young Women's Breast Cancer Study, a multisite prospective cohort of women diagnosed with stage 0-IV breast cancer at age ≤ 40 years, enrolled from 2006 to 2016. Clinical data were collected from patient surveys and medical records. Pathologic features were examined by central review. Data were summarized with descriptive statistics and groups were compared with χ2 and Fisher's exact tests. RESULTS: Among the 98 patients included, median age of diagnosis was 38 years; 36 (37%) patients were symptomatic on presentation. DCIS nuclear grade was high in 35%, intermediate in 50%, and low in 15% of lesions; 36% of lesions had comedonecrosis. The majority of patients underwent bilateral mastectomy (57%), 16 (16%) underwent unilateral mastectomy, and 26 (27%) underwent lumpectomy, most of whom received radiation. Few (13%) patients were receiving tamoxifen therapy 1 year postdiagnosis. Over a median follow-up of 8.4 years, six patients (6%) had disease recurrence, including five locoregional and one distant event. CONCLUSIONS: A high proportion of young women with DCIS underwent mastectomy with or without contralateral prophylactic mastectomy. Although DCIS was frequently symptomatic on presentation and exhibited unfavorable pathologic factors, clinicopathologic features were overall heterogeneous and few recurrences occurred. This underscores the need for careful consideration of treatment options in young women with DCIS.

Design and Development of a Digital Counseling Program for Chronic Kidney Disease.

Background: Self-management has shown to improve the quality of life in patients with chronic kidney disease (CKD). Readily accessible self-management tools are essential in promoting adherence to self-care behaviors. In recognizing that digital health facilitates efficient access to self-management programs, we developed a digital counseling program, ODYSSEE Kidney Health, to promote self-care behaviors while supporting health-related quality of life. Objective: To present the design and development of ODYSSEE Kidney Health for digital counseling for patients with CKD. Design: The study involved an iterative design process based on user-centered design principles to develop the digital counseling program, ODYSSEE Kidney Health. Setting: A sample of 10 to 15 participants were purposively sampled from nephrology clinics at the University Health Network, Toronto, Canada. Methods: Participants underwent 2 phases in the development process. In each phase, participants were presented with a component of the program, asked to perform goal-oriented tasks, and participate in the "think-aloud" process. Semi-structured interviews followed the first phase to identify feedback about the overall program. Thematic analysis of the interviews identified themes from the usability testing. Descriptive statistics were used to summarize patient demographic data. Results: We enrolled 11 participants (n = 7 males, n = 4 females, ages 30-82). The main themes generated anchored on (1) impact on nephrology care, (2) technical features, and (3) CKD content. Overall, participants reported positive satisfaction toward the navigation, layout, and content of the program. They cited the value of the program in their daily CKD care. Limitations: Study limitations included using a single center to recruit participants, most of the participants having prior technology use, and using one module as a representative of the entire digital platform. Conclusion: The acceptability of a digital counseling program for patients with CKD relies on taking the patients' perspective using a user-centered design process. It is vital in ensuring adoption and adherence to self-management interventions aimed at sustaining behavioral change.

Contexte: L'autogestion s'est avérée efficace pour améliorer la qualité de vie des patients atteints d'insuffisance rénale chronique (IRC). Des outils d'autogestion facilement accessibles sont essentiels pour favoriser l'adhésion aux comportements d'autogestion. Conscients que la santé numérique facilite l'accès efficace aux programmes d'autogestion, nous avons mis au point un programme de consultation numérique, ODYSSEE Kidney Health, afin de promouvoir les comportements d'autogestion tout en soutenant la qualité de vie liée à la santé. Objectif: Présenter la conception et le développement du programme de consultation numérique ODYSSEE Kidney Health, destiné aux patients atteints d'IRC. Conception: L'étude a impliqué un processus de conception itératif fondé sur des principes de conception axés sur l'utilisateur pour développer le programme de consultation numérique, ODYSSEE Kidney Health. Participants: Un échantillon de 10 à 15 participants choisis à dessein dans des cliniques de néphrologie du University Health Network de Toronto (Canada). Méthodologie: Les participants ont pris part à deux phases du processus de développement. À chaque phase, une composante du programme a été présentée aux participants et ceux-ci ont été invités à effectuer des tâches axées sur les objectifs et à participer à un processus de « réflexion à voix haute ¼. Des entretiens semi-structurés ont suivi la première phase pour fournir de la rétroaction sur le programme dans son ensemble. L'analyse thématique des entretiens a permis de dégager les thèmes des tests d'utilisabilité. Des statistiques descriptives ont servi à présenter les données démographiques des patients. Résultats: Nous avons inclus 11 participants (7 hommes, 4 femmes; de 30 à 82 ans). Les principaux thèmes générés sont ancrés sur: 1) l'impact sur les soins de néphrologie, 2) les caractéristiques techniques et 3) le contenu sur l'IRC. Dans l'ensemble, les participants étaient satisfaits de leur expérience de navigation, de la disposition des contenus et du contenu du programme. Ils ont mentionné la valeur du programme dans leurs soins quotidiens d'IRC. Limites: Un seul centre a été utilisé pour recruter des participants, la majorité des participants avait déjà utilisé la technologie et un seul module a été utilisé pour représenter l'ensemble de la plateforme numérique. Conclusion: L'acceptabilité d'un programme de consultation numérique destiné aux patients atteints d'IRC repose sur la prise en compte du point de vue des patients par le biais d'un processus de conception axé sur l'utilisateur. Ceci est essentiel pour garantir l'adoption et l'adhésion aux interventions d'autogestion visant à pérenniser les changements de comportement.

Breast cancer awareness among Afghan refugee women in Turkey.

Background Refugees and asylum-seekers have lower levels of cancer awareness and this contributes to low rates of screening and more advanced cancers at diagnosis, compared to non-refugee populations, due largely to reduced access to medical information and care. The global Afghan refugee population is rapidly increasing with the ongoing Afghan political crisis. The present study investigates breast cancer (BC) awareness among Afghan refugee women. Methods: A cross-sectional survey of Afghan refugee women residing in Turkey was performed in September 2021. A validated BC patient awareness assessment, the Breast Cancer Awareness Measure (BCAM), was used to assess participants' knowledge of seven domains of BC: symptoms, self-examination, ability to notice breast changes, age-related risk of BC, urgency of addressing changes in the breast, BC risk factors, and BC screening. BCAM was translated into patients' native language and administered verbally by a physician with the assistance of an official interpreter. Routine statistical methods were employed for data analysis. Findings: A total of 430 patients were recruited to the study. The response rate was 97·7% (420 patients). The median participant age was 35 years (range: 18 to 68 years). The majority of participants (84%) had no formal education. Most participants (96%) were married, and most (95%) were not employed. Awareness of warning signs of BC was low: only seven to 18% of participants recognized 11 common warning signs of BC. Participant use of breast self-exam (BSE) was low, with 82% of participants stating they rarely or never complete BSE. Zero of 420 patients reported ever seeing a physician for a change in their breasts. Awareness of risk factors for BC was also low: only 15% of participants recognized increasing age as a risk factor for BC, and other risk factors were only recognized by four to 39% of participants. Interpretation: BC awareness among Afghan refugee women is critically low. There is an urgent need to target this population for practical interventions to increase BC awareness, in addition to screening and earlier diagnosis. Evidence-based interventions include educational sessions in patients' native language and use of BSE and clinical breast examination for screening. Funding: American Society for Radiation Oncology (ASTRO) - Association of Residents in Radiation Oncology (ARRO) Global Health Scholar Grant, Dana-Farber Cancer Institute Jay Harris Junior Faculty Research Grant.

Integration of Radiation and Reconstruction After Mastectomy.

Postmastectomy radiation therapy (PMRT) is a mainstay of local therapy for many breast cancer patients. Patients undergoing mastectomy typically are offered options for breast reconstruction. For patients who are candidates for PMRT, there are ongoing challenges with combining optimal radiation technique to prioritize oncologic outcomes, against the goals of minimizing toxicity and achieving the best reconstruction outcomes. The process by which these decisions are made continues to evolve as surgical and radiation techniques have improved and expanded, and as more patients with different risk profiles for local recurrence are receiving PMRT. We review the considerations regarding the different types of reconstruction and timing with radiation treatment. We also review the technical radiation consideration such as dose-fractionation, use of bolus and scar boost, exploring the controversies associated with the nuanced decisions regarding radiation and reconstructive surgery which are influenced by variables that are under continued investigation.

RNase III-CLASH of multi-drug resistant Staphylococcus aureus reveals a regulatory mRNA 3'UTR required for intermediate vancomycin resistance.

Treatment of methicillin-resistant Staphylococcus aureus infections is dependent on the efficacy of last-line antibiotics including vancomycin. Treatment failure is commonly linked to isolates with intermediate vancomycin resistance (termed VISA). These isolates have accumulated point mutations that collectively reduce vancomycin sensitivity, often by thickening the cell wall. Changes in regulatory small RNA expression have been correlated with antibiotic stress in VISA isolates however the functions of most RNA regulators is unknown. Here we capture RNA-RNA interactions associated with RNase III using CLASH. RNase III-CLASH uncovers hundreds of novel RNA-RNA interactions in vivo allowing functional characterisation of many sRNAs for the first time. Surprisingly, many mRNA-mRNA interactions are recovered and we find that an mRNA encoding a long 3' untranslated region (UTR) (termed vigR 3'UTR) functions as a regulatory 'hub' within the RNA-RNA interaction network. We demonstrate that the vigR 3'UTR promotes expression of folD and the cell wall lytic transglycosylase isaA through direct mRNA-mRNA base-pairing. Deletion of the vigR 3'UTR re-sensitised VISA to glycopeptide treatment and both isaA and vigR 3'UTR deletions impact cell wall thickness. Our results demonstrate the utility of RNase III-CLASH and indicate that S. aureus uses mRNA-mRNA interactions to co-ordinate gene expression more widely than previously appreciated.

A functional circuit formed by the autonomic nerves and myofibroblasts controls mammalian alveolar formation for gas exchange.

Alveolar formation increases the surface area for gas exchange. A molecular understanding of alveologenesis remains incomplete. Here, we show that the autonomic nerve and alveolar myofibroblast form a functional unit in mice. Myofibroblasts secrete neurotrophins to promote neurite extension/survival, whereas neurotransmitters released from autonomic terminals are necessary for myofibroblast proliferation and migration, a key step in alveologenesis. This establishes a functional link between autonomic innervation and alveolar formation. We also discover that planar cell polarity (PCP) signaling employs a Wnt-Fz/Ror-Vangl cascade to regulate the cytoskeleton and neurotransmitter trafficking/release from the terminals of autonomic nerves. This represents a new aspect of PCP signaling in conferring cellular properties. Together, these studies offer molecular insight into how autonomic activity controls alveolar formation. Our work also illustrates the fundamental principle of how two tissues (e.g., nerves and lungs) interact to build alveoli at the organismal level.

Acquisition of cellular properties during alveolar formation requires differential activity and distribution of mitochondria.

Alveolar formation requires coordinated movement and interaction between alveolar epithelial cells, mesenchymal myofibroblasts, and endothelial cells/pericytes to produce secondary septa. These processes rely on the acquisition of distinct cellular properties to enable ligand secretion for cell-cell signaling and initiate morphogenesis through cellular contraction, cell migration, and cell shape change. In this study, we showed that mitochondrial activity and distribution play a key role in bestowing cellular functions on both alveolar epithelial cells and mesenchymal myofibroblasts for generating secondary septa to form alveoli in mice. These results suggest that mitochondrial function is tightly regulated to empower cellular machineries in a spatially specific manner. Indeed, such regulation via mitochondria is required for secretion of ligands, such as platelet-derived growth factor, from alveolar epithelial cells to influence myofibroblast proliferation and contraction/migration. Moreover, mitochondrial function enables myofibroblast contraction/migration during alveolar formation. Together, these findings yield novel mechanistic insights into how mitochondria regulate pivotal steps of alveologenesis. They highlight selective utilization of energy in cells and diverse energy demands in different cellular processes during development. Our work serves as a paradigm for studying how mitochondria control tissue patterning.

The lungs display an intricate, tree-shaped structure which enables the complex gas exchanges required for life. The end of each tiny 'branch' hosts delicate air sacs, or alveoli, which are further divided by internal walls called septa. In mammals, this final structure is acquired during the last stage of lung development. Then, many different types of cells in the immature alveoli multiply and reach the right location to start constructing additional septa. While the structural changes underlining alveoli maturation are well-studied, the energy requirements for that process remain poorly understood. In particular, the exact role of the mitochondria, the cellular compartments that power most life processes, is still unclear. Zhang et al. therefore set out to map, in detail, the role of mitochondria in alveolar development. Microscope imaging revealed how mitochondria were unevenly distributed within the lung cells of newborn mice. Mitochondria accumulated around the machinery that controls protein secretion in the epithelial cells that line the air sacs, and around the contractile apparatus in the underlying cells (the 'myofibroblasts'). Genetically altering the mice to reduce mitochondrial activity or perturb mitochondrial location in these two cell types produced defective alveoli with fewer septa, but it had no effect on lung development before alveoli formation. This suggests that the formation of alveoli requires more energy than other steps of lung development. Disrupting mitochondrial activity or location also compromised how epithelial cells produced chemical signals necessary for the contraction or migration of the myofibroblasts. Together, these results highlight the importance of tightly regulating mitochondrial activity and location during lung patterning. In the future, this insight could lay the groundwork to determine how energy requirements in various tissues shape other biological processes in health and disease.

The Role and Targets of the RNA-Binding Protein ProQ in the Gram-Negative Bacterial Pathogen Pasteurella multocida.

The Gram-negative pathogen Pasteurella multocida is the causative agent of many important animal diseases. While a number of P. multocida virulence factors have been identified, very little is known about how gene expression and protein production is regulated in this organism. One mechanism by which bacteria regulate transcript abundance and protein production is riboregulation, which involves the interaction of a small RNA (sRNA) with a target mRNA to alter transcript stability and/or translational efficiency. This interaction often requires stabilization by an RNA-binding protein such as ProQ or Hfq. In Escherichia coli and a small number of other species, ProQ has been shown to play a critical role in stabilizing sRNA-mRNA interactions and preferentially binds to the 3' stem-loop regions of the mRNA transcripts, characteristic of intrinsic transcriptional terminators. The aim of this study was to determine the role of ProQ in regulating P. multocida transcript abundance and identify the RNA targets to which it binds. We assessed differentially expressed transcripts in a proQ mutant and identified sites of direct ProQ-RNA interaction using in vivo UV-cross-linking and analysis of cDNA (CRAC). These analyses demonstrated that ProQ binds to, and stabilizes, ProQ-dependent sRNAs and transfer RNAs in P. multocida via adenosine-enriched, highly structured sequences. The binding of ProQ to two RNA molecules was characterized, and these analyses showed that ProQ bound within the coding sequence of the transcript PmVP161_1121, encoding an uncharacterized protein, and within the 3' region of the putative sRNA Prrc13. IMPORTANCE Regulation in P. multocida involving the RNA-binding protein Hfq is required for hyaluronic acid capsule production and virulence. This study further expands our understanding of riboregulation by examining the role of a second RNA-binding protein, ProQ, in transcript regulation and abundance in P. multocida.

Prolonged Glycemic Adaptation Following Transition From a Low- to High-Carbohydrate Diet: A Randomized Controlled Feeding Trial.

OBJECTIVE: Consuming ≥150 g/day carbohydrate is recommended for 3 days before an oral glucose tolerance test (OGTT) for diabetes diagnosis. For evaluation of this recommendation, time courses of glycemic changes following transition from a very-low-carbohydrate (VLC) to high-carbohydrate diet were assessed with continuous glucose monitoring (CGM). RESEARCH DESIGN AND METHODS: After achieving a weight loss target of 15% (±3%) on the run-in VLC diet, participants (18-50 years old, BMI ≥27 kg/m2) were randomly assigned for 10 weeks to one of three isoenergetic diets: VLC (5% carbohydrate and 77% fat); high carbohydrate, high starch (HC-Starch) (57% carbohydrate and 25% fat, including 20% refined grains); and high carbohydrate, high sugar (HC-Sugar) (57% carbohydrate and 25% fat, including 20% sugar). CGM was done throughout the trial (n = 64) and OGTT at start and end (n = 41). All food was prepared in a metabolic kitchen and consumed under observation. RESULTS: Glucose metrics continued to decline after week 1 in the HC-Starch and HC-Sugar groups (P < 0.05) but not VLC. During weeks 2-5, fasting and 2-h glucose (millimoles per liter per week) decreased in HC-Starch (fasting -0.10, P = 0.001; 2 h -0.10, P = 0.04). During weeks 6-9, 2-h glucose decreased in HC-Starch (-0.07, P = 0.01) and fasting and 2-h glucose decreased in HC-Sugar (fasting -0.09, P = 0.001; 2 h -0.09, P = 0.003). The number of participants with abnormal glucose tolerance by OGTT remained 10 (of 16) in VLC at start and end but decreased from 17 to 9 (of 25) in both high-carbohydrate groups. CONCLUSIONS: Physiological adaptation from a low- to high-carbohydrate diet may require many weeks, with implications for the accuracy of diabetes tests, interpretation of macronutrient trials, and risks of periodic planned deviations from a VLC diet.