Genetic complexity of diagnostically unresolved Ehlers-Danlos syndrome.

BACKGROUND: The Ehlers-Danlos syndromes (EDS) are heritable disorders of connective tissue (HDCT), reclassified in the 2017 nosology into 13 subtypes. The genetic basis for hypermobile Ehlers-Danlos syndrome (hEDS) remains unknown. METHODS: Whole exome sequencing (WES) was undertaken on 174 EDS patients recruited from a national diagnostic service for complex EDS and a specialist clinic for hEDS. Patients had already undergone expert phenotyping, laboratory investigation and gene sequencing, but were without a genetic diagnosis. Filtered WES data were reviewed for genes underlying Mendelian disorders and loci reported in EDS linkage, transcriptome and genome-wide association studies (GWAS). A genetic burden analysis (Minor Allele Frequency (MAF) <0.05) incorporating 248 Avon Longitudinal Study of Parents and Children (ALSPAC) controls sequenced as part of the UK10K study was undertaken using TASER methodology. RESULTS: Heterozygous pathogenic (P) or likely pathogenic (LP) variants were identified in known EDS and Loeys-Dietz (LDS) genes. Multiple variants of uncertain significance where segregation and functional analysis may enable reclassification were found in genes associated with EDS, LDS, heritable thoracic aortic disease (HTAD), Mendelian disorders with EDS symptomatology and syndromes with EDS-like features. Genetic burden analysis revealed a number of novel loci, although none reached the threshold for genome-wide significance. Variants with biological plausibility were found in genes and pathways not currently associated with EDS or HTAD. CONCLUSIONS: We demonstrate the clinical utility of large panel-based sequencing and WES for patients with complex EDS in distinguishing rare EDS subtypes, LDS and related syndromes. Although many of the P and LP variants reported in this cohort would be identified with current panel testing, they were not at the time of this study, highlighting the use of extended panels and WES as a clinical tool for complex EDS. Our results are consistent with the complex genetic architecture of EDS and suggest a number of novel hEDS and HTAD candidate genes and pathways.

National Pediatrician-Scientist Collaborative Workgroup comment on new ACGME requirements' impact on pediatric physician-scientists.

BACKGROUND: The ACGME recently released its recommendation for updates to the program requirements for pediatrics. These updates proposed changes to allocation of resident clinical time and a greater emphasis on individualization. The potential impact of these changes on the training of physician-scientists is discussed. METHODS: Discussion of the proposed changes was held within the members of the National Pediatrician-Scientist Collaborative Workgroup, a group that represents scientists, trainees, program directors, chairs, and physician-scientist educators at nearly 30 residency programs from across the US with a focus on understanding and developing optimal approaches to physician-scientist training. Consideration was given to the both the personal and institutional impact of the proposal for physician-scientist development. RESULTS: Both threats and opportunities were identified. Key opportunities include the enhanced individualized training time that could be used to explore research. Threats include re-allocation of clinical training time that may strain institutions financially, expand clinical service requirements for other early career stage individuals, and alter exposure to a broad range of pediatric specialists and sub-specialists that impact career development. CONCLUSION: The NPSCW encourages consideration of the impact of changing program requirements on physician-scientist development to include ongoing discussion amongst mentors, programs, and trainees to understand and mitigate impact of new program requirements on the development of pediatrician-scientists.

Evidence of heat sensitivity in people with Parkinson's disease.

Examining how heat affects people with Parkinson's disease is essential for informing clinical decision-making, safety, well-being, and healthcare planning. While there is evidence that the neuropathology associated with Parkinson's disease affects thermoregulatory mechanisms, little attention has been given to the association of heat sensitivity to worsening symptoms and restricted daily activities in people with this progressive disease. Using a cross-sectional study design, we examined the experiences of people diagnosed with Parkinson's disease in the heat. Two-hundred and forty-seven people completed an online survey (age: 66.0 ± 9.2 years; sex: male = 102 (41.3%), female = 145 (58.7%)), of which 195 (78.9%) reported becoming more sensitive to heat with Parkinson's disease. Motor and nonmotor symptoms worsened with heat in 182 (73.7%) and 203 (82.2%) respondents, respectively. The most commonly reported symptoms to worsen included walking difficulties, balance impairment, stiffness, tremor, fatigue, sleep disturbances, excess sweating, difficulty concentrating, and light-headedness when standing. Concerningly, over half indicated an inability to work effectively in the heat, and nearly half reported that heat impacted their ability to perform household tasks and social activities. Overall, heat sensitivity was common in people with Parkinson's disease and had a significant impact on symptomology, day-to-day activities and quality of life.

Mechano-chemical feedback mediated competition for BMP signalling leads to pattern formation.

Developmental patterning is thought to be regulated by conserved signalling pathways. Initial patterns are often broad before refining to only those cells that commit to a particular fate. However, the mechanisms by which pattern refinement takes place remain to be addressed. Using the posterior crossvein (PCV) of the Drosophila pupal wing as a model, into which bone morphogenetic protein (BMP) ligand is extracellularly transported to instruct vein patterning, we investigate how pattern refinement is regulated. We found that BMP signalling induces apical enrichment of Myosin II in developing crossvein cells to regulate apical constriction. Live imaging of cellular behaviour indicates that changes in cell shape are dynamic and transient, only being maintained in those cells that retain vein fate competence after refinement. Disrupting cell shape changes throughout the PCV inhibits pattern refinement. In contrast, disrupting cell shape in only a subset of vein cells can result in a loss of BMP signalling. We propose that mechano-chemical feedback leads to competition for the developmental signal which plays a critical role in pattern refinement.

Underpinning the Food Matrix Regulation of Postexercise Myofibrillar Protein Synthesis by Comparing Salmon Ingestion With the Sum of Its Isolated Nutrients in Healthy Young Adults.

BACKGROUND: Protein is most commonly consumed as whole foods as opposed to single nutrients. However, the food matrix regulation of the postprandial muscle protein synthetic response has received little attention. OBJECTIVES: The purpose of this study was to assess the effects of eating salmon (SAL) and of ingesting the same nutrients as an isolated mixture of crystalline amino acids and fish oil (ISO) on the stimulation of postexercise myofibrillar protein synthesis (MPS) and whole-body leucine oxidation rates in healthy young adults. METHODS: Ten recreationally active adults (24 ± 4 y; 5 men, 5 women) performed an acute bout of resistance exercise, followed by the ingestion of SAL or ISO in a crossover fashion. Blood, breath, and muscle biopsies were collected at rest and after exercise during primed continuous infusions of L-[ring-2H5]phenylalanine and L-[1-13C]leucine. All data are presented as means ± SD and/or mean differences (95% CIs). RESULTS: Postprandial essential amino acid (EAA) concentrations peaked earlier (P = 0.024) in the ISO group than those in the SAL group. Postprandial leucine oxidation rates increased over time (P < 0.001) and peaked earlier in the ISO group (1.239 ± 0.321 nmol/kg/min; 63 ± 25 min) than those in the SAL group (1.230 ± 0.561 nmol/kg/min; 105 ± 20 min; P = 0.003). MPS rates for SAL (0.056 ± 0.022 %/h; P = 0.001) and ISO (0.046 ± 0.025 %/h; P = 0.025) were greater than the basal rates (0.020 ± 0.011 %/h) during the 0- to 5-h recovery period, with no differences between conditions (P = 0.308). CONCLUSION: We showed that the postexercise ingestion of SAL or ISO stimulate postexercise MPS rates with no differences between the conditions. Thus, our results indicate that ingesting protein from SAL as a whole-food matrix is similarly anabolic to ISO in healthy young adults. This trial was registered at www. CLINICALTRIALS: gov as NCT03870165.

Greater plasma essential amino acids and lower 3-methylhistidine with higher protein intake during endurance training: a randomised control trial.

Endurance exercise alters amino acid (AA) metabolism that necessitates greater AA intake in the post exercise recovery period to support recovery. Thus, daily AA ingestion during a period of endurance training may affect the metabolically active plasma free AA pool, which is otherwise maintained during periods of inadequate protein intake by the breakdown of skeletal muscle proteins. Nine endurance-trained males completed a 4-day running protocol (20 km, 5 km, 10 km and 20 km on days 1-4, respectively) on three occasions with a controlled diet providing different protein intakes [0.94(LOW), 1.20(MOD) or 1.83gprotein kgbody mass-1 day-1 (HIGH)]. Urine collected over 24 h on day-4 and plasma collected after an overnight fast on day-5 were analyzed for free AA (plasma) and 3-methylhistidine (3MH; plasma and urine), a marker of myofibrillar protein breakdown. There was an effect of protein intake (HIGH > MOD/LOW; P < 0.05) on fasted plasma essential AA, branched chain AA and 3MH but no effect on 24-h urinary 3-MH excretion. Consuming a previously determined optimal daily protein intake of 1.83 g kg-1 day-1 during endurance training maintains fasted plasma free AA and may attenuate myofibrillar protein catabolism, although this latter effect was not detected in 24-h urinary excretion. The maintenance of the metabolically active free plasma AA pool may support greater recovery from exercise and contribute to the previously determined greater whole-body net protein balance in this athletic population. TRN: NCT02801344 (June 15, 2016).

Leucine ingestion promotes mTOR translocation to the periphery and enhances total and peripheral RPS6 phosphorylation in human skeletal muscle.

The activation of the mechanistic target of rapamycin complex 1 (mTORC1), a master regulator of protein synthesis, by anabolic stimuli (such as muscle contraction or essential amino acids) involves its translocation to the cell periphery. Leucine is generally considered the most anabolic of amino acids for its ability to independently modulate muscle protein synthesis. However, it is currently unknown if free leucine impacts region-specific mTORC1-mediated phosphorylation events and protein-protein interactions. In this clinical trial (NCT03952884; registered May 16, 2019), we used immunofluorescence methods to investigate the role of dietary leucine on the postprandial regulation of mTORC1 and ribosomal protein S6 (RPS6), an important downstream readout of mTORC1 activity. Eight young, healthy, recreationally active males (n = 8; 23 ± 3 yrs) ingested 2 g of leucine with vastus lateralis biopsies collected at baseline, 30, 60, and 180 min postprandial. Leucine promoted mTOR translocation to the periphery (~ 18-29%; p ≤ 0.012) and enhanced mTOR localization with the lysosome (~ 16%; both p = 0.049) at 30 and 60 min post-feeding. p-RPS6Ser240/244 staining intensity, a readout of mTORC1 activity, was significantly elevated at all postprandial timepoints in both the total fiber (~ 14-30%; p ≤ 0.032) and peripheral regions (~ 16-33%; p ≤ 0.014). Additionally, total and peripheral p-RPS6Ser240/244 staining intensity at 60 min was positively correlated (r = 0.74, p = 0.036; r = 0.80, p = 0.016, respectively) with rates of myofibrillar protein synthesis over 180 min. The ability of leucine to activate mTORC1 in peripheral regions favors an enhanced rate of MPS, as this is the intracellular space thought to be replete with the cellular machinery that facilitates this anabolic process.

Estimation of skeletal muscle mass in 4-year-old children using the D3-creatine dilution method.

BACKGROUND: Given limited experience in applying the creatine-(methyl-D3) (D3Cr) dilution method to measure skeletal muscle mass (SMM) in young children, the feasibility of deployment in a fielding setting and performance of the method was assessed in a cohort of 4-year-old children in Dhaka, Bangladesh. METHODS: Following D3Cr oral dose (10 mg) administration, single fasting urine samples were collected at 2-4 days (n = 100). Twenty-four-hour post-dose collections and serial spot urine samples on days 2, 3 and 4 were obtained in a subset of participants (n = 10). Urinary creatine, creatinine, D3Cr and D3-creatinine enrichment were analyzed by liquid chromatography-tandem mass spectrometry. Appendicular lean mass (ALM) was measured by dual-energy x-ray absorptiometry and grip strength was measured by a hand-held dynamometer. RESULTS: SMM was measured successfully in 91% of participants, and there were no adverse events. Mean ± SD SMM was greater than ALM (4.5 ± 0.4 and 3.2 ± 0.6 kg, respectively). Precision of SMM was low (intraclass correlation = 0.20; 95% CI: 0.02, 0.75; n = 10). Grip strength was not associated with SMM in multivariable analysis (0.004 kg per 100 g of SMM; 95% CI: -0.031, 0.038; n = 91). CONCLUSIONS: The D3Cr dilution method was feasible in a community setting. However, high within-child variability in SMM estimates suggests the need for further optimization of this approach. IMPACT: The D3-creatine (D3Cr) stable isotope dilution method was considered a feasible method for the estimation of skeletal muscle mass (SMM) in young children in a community setting and was well accepted among participants. SMM was weakly associated with both dual-energy x-ray absorptiometry-derived values of appendicular lean mass and grip strength. High within-child variability in estimated values of SMM suggests that further optimization of the D3Cr stable isotope dilution method is required prior to implementation in community research settings.

Methane Emissions from Municipal Wastewater Collection and Treatment Systems.

Municipal wastewater collection and treatment systems are critical infrastructures, and they are also identified as major sources of anthropogenic CH4 emissions that contribute to climate change. The actual CH4 emissions at the plant- or regional level vary greatly due to site-specific conditions as well as high seasonal and diurnal variations. Here, we conducted the first quantitative analysis of CH4 emissions from different types of sewers and water resource recovery facilities (WRRFs). We examined variations in CH4 emissions associated with methods applied in different monitoring campaigns, and identified main CH4 sources and sinks to facilitate carbon emission reduction efforts in the wastewater sector. We found plant-wide CH4 emissions vary by orders of magnitude, from 0.01 to 110 g CH4/m3 with high emissions associated with plants equipped with anaerobic digestion or stabilization ponds. Rising mains show higher dissolved CH4 concentrations than gravity sewers when transporting similar raw sewage under similar environmental conditions, but the latter dominates most collection systems around the world. Using the updated data sets, we estimated annual CH4 emission from the U.S. centralized, municipal wastewater treatment to be approximately 10.9 ± 7.0 MMT CO2-eq/year, which is about twice as the IPCC (2019) Tier 2 estimates (4.3-6.1 MMT CO2-eq/year). Given CH4 emission control will play a crucial role in achieving net zero carbon goals by the midcentury, more studies are needed to profile and mitigate CH4 emissions from the wastewater sector.

Underestimation of Sector-Wide Methane Emissions from United States Wastewater Treatment.

An increasing percentage of US waste methane (CH4) emissions come from wastewater treatment (10% in 1990 to 14% in 2019), although there are limited measurements across the sector, leading to large uncertainties in current inventories. We conducted the largest study of CH4 emissions from US wastewater treatment, measuring 63 plants with average daily flows ranging from 4.2 × 10-4 to 8.5 m3 s-1 (<0.1 to 193 MGD), totaling 2% of the 62.5 billion gallons treated, nationally. We employed Bayesian inference to quantify facility-integrated emission rates with a mobile laboratory approach (1165 cross-plume transects). The median plant-averaged emission rate was 1.1 g CH4 s-1 (0.1-21.6 g CH4 s-1; 10th/90th percentiles; mean 7.9 g CH4 s-1), and the median emission factor was 3.4 × 10-2 g CH4 (g influent 5 day biochemical oxygen demand; BOD5)-1 [0.6-9.9 × 10-2 g CH4 (g BOD5)-1; 10th/90th percentiles; mean 5.7 × 10-2 g CH4 (g BOD5)-1]. Using a Monte Carlo-based scaling of measured emission factors, emissions from US centrally treated domestic wastewater are 1.9 (95% CI: 1.5-2.4) times greater than the current US EPA inventory (bias of 5.4 MMT CO2-eq). With increasing urbanization and centralized treatment, efforts to identify and mitigate CH4 emissions are needed.

Offsetting environmental impacts beyond climate change: the Circular Ecosystem Compensation approach.

Since the Paris Agreement entered into force, climate neutrality and associated compensation schemes are even more on the agenda of politics and companies. Challenges of existing offsetting schemes include the rather theoretical saving scenario and the limited scope of considered impacts. To address some of these limitations, this paper proposes the Circular Ecosystem Compensation (CEC) approach based on monetization of LCA results and Ecosystem Valuation. CEC consists of six steps: i) carrying out a life cycle assessment, ii) reducing the environmental impacts, iii) determining environmental costs applying monetization methods, iv) deriving the environmental value based on restoration costs methods, v) implementing the ecological restoration of ecosystems and vi) monitoring of the renaturation measures. Thus, CEC allows to offset a broad set of environmental impacts beyond climate change (e.g., acidification, eutrophication, land use, water use) in a real ecosystem by renaturation of degraded ecosystems. Environmental burdens and environmental benefits are balanced on a monetary basis, as the renaturation measures are monetized and used to compensate the monetized LCA results, e.g., of a product, organization or individual. In a case study, the implementation of the approach is presented to show the practical implementation of the CEC. The challenges of CEC include the integration of further impact categories, the availability of up-to-date and reliable monetization methods, the asynchrony and time-lag of the compensation from an ecosystem and biodiversity perspective and the proof of cost-efficiency of the renaturation measures. It is further discussed, if CEC can be a step beyond "climate neutrality" towards "environmental neutrality". The proposed approach should be further tested and is intended to foster progress in more comprehensive and robust offsetting of environmental impacts beyond climate change.

RPS6 phosphorylation occurs to a greater extent in the periphery of human skeletal muscle fibers, near focal adhesions, after anabolic stimuli.

Following anabolic stimuli (mechanical loading and/or amino acid provision), the mechanistic target of rapamycin complex 1 (mTORC1), a master regulator of protein synthesis, translocates toward the cell periphery. However, it is unknown if mTORC1-mediated phosphorylation events occur in these peripheral regions or before translocation (i.e., in central regions). We therefore aimed to determine the cellular location of a mTORC1-mediated phosphorylation event, RPS6Ser240/244, in human skeletal muscle following anabolic stimuli. Fourteen young, healthy males either ingested a protein-carbohydrate beverage (0.25 g/kg protein and 0.75 g/kg carbohydrate) alone [n = 7; 23 ± 5 yr; 76.8 ± 3.6 kg; and 13.6 ± 3.8% body fat (BF), FED] or following a whole body resistance exercise bout (n = 7; 22 ± 2 yr; 78.1 ± 3.6 kg; and 12.2 ± 4.9%BF, EXFED). Vastus lateralis muscle biopsies were obtained at rest (PRE) and 120 and 300 min following anabolic stimuli. RPS6Ser240/244 phosphorylation measured by immunofluorescent staining or immunoblot was positively correlated (r = 0.76, P < 0.001). Peripheral staining intensity of p-RPS6Ser240/244 increased above PRE in both FED and EXFED at 120 min (∼54% and ∼138%, respectively, P < 0.05) but was greater in EXFED at both poststimuli time points (P < 0.05). The peripheral-to-central ratio of p-RPS6240/244 staining displayed a similar pattern, even when corrected for total RPS6 distribution, suggesting RPS6 phosphorylation occurs to a greater extent in the periphery of fibers. Moreover, p-RPS6Ser240/244 intensity within paxillin-positive regions, a marker of focal adhesion complexes, was elevated at 120 min irrespective of stimulus (P = 0.006) before returning to PRE at 300 min. These data confirm that RPS6Ser240/244 phosphorylation occurs in the region of human muscle fibers to which mTOR translocates following anabolic stimuli and identifies focal adhesion complexes as a potential site of mTORC1 regulation in vivo.

Identification of underexplored mesenchymal and vascular-related cell populations in human skeletal muscle.

Skeletal muscle repair and maintenance are directly and indirectly supported by interstitial cell populations such as vascular cells and fibro-adipogenic progenitors (FAPs), a subset of which express Twist2 and possess direct myogenic potential. Furthermore, work in rodents has highlighted the potential of pericytes to act as progenitor cells, giving rise to muscle cells and transdifferentiating into endothelial cells. However, less is understood about these populations in human skeletal muscle. Here, we performed single-cell RNA sequencing (scRNAseq) on ∼2,000 cells isolated from the human semitendinosus muscle of young individuals. This demonstrated the presence of a vascular-related cell type that expressed pericyte and pan-endothelial genes that we localized to large blood vessels within skeletal muscle cross sections and termed endothelial-like pericytes (ELPCs). RNA velocity analysis indicated that ELPCs may represent a "transition state" between endothelial cells and pericytes. Analysis of published scRNAseq data sets revealed evidence for ELPCs in trunk and heart musculature, which showed transcriptional similarity. In addition, we identified a subset of FAPs expressing TWIST2 mRNA and protein. Human TWIST2-expressing cells were anatomically and transcriptionally comparable to mouse Twist2 cells as they were restricted to the myofiber interstitium, expressed fibrogenic genes but lacked satellite cell markers, and colocalized with the FAPs marker PDGFRα in human muscle cross sections. Taken together, these results highlight the complexity of stromal cells residing in human skeletal muscle and support the utility of scRNAseq for discovery and characterization of poorly described cell populations.

Challenges of rapamycin repurposing as a potential therapeutic candidate for COVID-19: implications for skeletal muscle metabolic health in older persons.

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged as the causative agent of the ongoing coronavirus disease 2019 (COVID-19) pandemic that has spread worldwide, resulting in over 6 million deaths as of March 2022. Older people have been disproportionately affected by the disease, as they have a greater risk of hospitalization, are more vulnerable to severe infection, and have higher mortality than younger patients. Although effective vaccines have been rapidly developed and administered globally, several clinical trials are ongoing to repurpose existing drugs to combat severe infection. One such drug, rapamycin, is currently under study for this purpose, given its immunosuppressant effects that are mediated by its inhibition of the mechanistic target of rapamycin (mTOR), a master regulator of cell growth. Consistent with this premise, acute rapamycin administration in young healthy humans blocks or attenuates mTOR and its downstream effectors, leading to the inhibition of muscle protein synthesis (MPS). Skeletal muscle mass declines when MPS is chronically lower than muscle protein breakdown. This is consequential for older people who are more susceptible to anabolic resistance (i.e., the blunting of MPS) due to reduced activity, sedentariness, or bed rest such as that associated with COVID-19 hospitalization, and who have also demonstrated a delayed or blunted ability to regain inactivity-induced muscle loss. The lack of studies investigating rapamycin administration on skeletal muscle in older people, and the emergence of effective antiviral medications against severe infection, may indicate the reduced relevance of drug repurposing for present or future pandemics.

A pragmatic low carbohydrate diet intervention changes neither carbohydrate consumption nor glycemia in adolescents and young adults with type 1 diabetes in a randomized trial.

OBJECTIVE: Despite enthusiasm for low carbohydrate diets (LCDs) among patients with type 1 diabetes (T1DM), no prospective study has investigated outcomes in adolescent T1DM. We aimed to quantify a pragmatic LCD intervention's impact on glycemia, lipidemia, and quality of life (QOL) in adolescents with T1DM. RESEARCH DESIGN AND METHODS: At an academic center, we randomized 39 patients with T1DM aged 13-21 years to one of three 12-week interventions: an LCD, an isocaloric standard carbohydrate diet (SCD), or general diabetes education without a prescriptive diet. Glycemic outcomes included glycosylated hemoglobin (HbA1c) and continuous glucose monitoring. RESULTS: There were no significant differences in glycemic, lipidemic, or QOL parameters between groups at any timepoint. Median HbA1c was similar at baseline between groups and did not change appreciably (7.9%-8.4% in LCDs, 7.9%-7.9% in SCDs, and 8.2%-7.8% in controls). Change in carbohydrate consumption was minimal with only one participant reaching target carbohydrate intake. CONCLUSIONS: This pragmatic LCD intervention did not alter carbohydrate consumption or glycemia. Although this study was unable to evaluate a highly controlled LCD, it indicates that adolescents are unlikely to implement an educational LCD intervention in routine clinic settings. Thus, this approach is unlikely to effectively mitigate hyperglycemia in adolescents.

Deep learning-based pancreas volume assessment in individuals with type 1 diabetes.

Pancreas volume is reduced in individuals with diabetes and in autoantibody positive individuals at high risk for developing type 1 diabetes (T1D). Studies investigating pancreas volume are underway to assess pancreas volume in large clinical databases and studies, but manual pancreas annotation is time-consuming and subjective, preventing extension to large studies and databases. This study develops deep learning for automated pancreas volume measurement in individuals with diabetes. A convolutional neural network was trained using manual pancreas annotation on 160 abdominal magnetic resonance imaging (MRI) scans from individuals with T1D, controls, or a combination thereof. Models trained using each cohort were then tested on scans of 25 individuals with T1D. Deep learning and manual segmentations of the pancreas displayed high overlap (Dice coefficient = 0.81) and excellent correlation of pancreas volume measurements (R2 = 0.94). Correlation was highest when training data included individuals both with and without T1D. The pancreas of individuals with T1D can be automatically segmented to measure pancreas volume. This algorithm can be applied to large imaging datasets to quantify the spectrum of human pancreas volume.

Coupling between dynamic 3D tissue architecture and BMP morphogen signaling during Drosophila wing morphogenesis.

At the level of organ formation, tissue morphogenesis drives developmental processes in animals, often involving the rearrangement of two-dimensional (2D) structures into more complex three-dimensional (3D) tissues. These processes can be directed by growth factor signaling pathways. However, little is known about how such morphological changes affect the spatiotemporal distribution of growth factor signaling. Here, using the Drosophila pupal wing, we address how decapentaplegic (Dpp)/bone morphogenetic protein (BMP) signaling and 3D wing morphogenesis are coordinated. Dpp, expressed in the longitudinal veins (LVs) of the pupal wing, initially diffuses laterally within both dorsal and ventral wing epithelia during the inflation stage to regulate cell proliferation. Dpp localization is then refined to the LVs within each epithelial plane, but with active interplanar signaling for vein patterning/differentiation, as the two epithelia appose. Our data further suggest that the 3D architecture of the wing epithelia and the spatial distribution of BMP signaling are tightly coupled, revealing that 3D morphogenesis is an emergent property of the interactions between extracellular signaling and tissue shape changes.

Image quality improvement and motion degradation reduction in shoulder MR imaging: comparison of BLADE and rectilinear techniques at 3-Tesla scanning.

OBJECTIVE: MR imaging of joints, particularly shoulder, requires a high degree of spatial resolution to ascertain anatomy and pathology. Unfortunately, motion artifacts can reduce the clinical quality of the examinations. BLADE sequence reduces motion degradation improving overall diagnostic imaging quality. The objective was to compare standard, rectilinear k-space coverage turbo spin echo (TSE), and BLADE sequences. MATERIAL AND METHODS: Over a 4-month period, fifty-seven consecutive patients (22 males, 35 females; mean age: 48.5 years, range: 23-64 years) were scanned using traditional intermediate-weighted spin echo and BLADE sequences. Qualitative evaluation was performed by three musculoskeletal fellowship trained radiologists, each with more than 5 years of experience. Image sequences were evaluated using a Likert scale for each of the following five categories: motion degradation, ghosting/phase misregistration artifacts, star/radial encoding artifacts, fat suppression quality, and overall diagnostic quality. Additionally, image sequences were evaluated for signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) using manually drawn regions of interest (ROI) analysis. RESULTS: Ghosting and phase artifacts were lower within BLADE sequence while streak artifacts were higher (p < 0.001). Image fat suppression, tendon and labral appearances, and the overall SNR and CNR were comparable on both sequences (p > 0.05). CONCLUSION: Addition of BLADE reduces motion degradation and improves overall diagnostic imaging quality. Application of BLADE in patient scans suspected of motion artifacts can reduce the frequency of repeat imaging in patients with claustrophobia or those where motion is a concern. By reducing overall imaging time and call backs, it could reduce the cost burden to patients and healthcare system.

Screening for Obstructive Sleep Apnea in Adults: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force.

Importance: Obstructive sleep apnea (OSA) is associated with adverse health outcomes. Objective: To review the evidence on screening for OSA in asymptomatic adults or those with unrecognized OSA symptoms to inform the US Preventive Services Task Force. Data Sources: PubMed/MEDLINE, Cochrane Library, Embase, and trial registries through August 23, 2021; surveillance through September 23, 2022. Study Selection: English-language studies of screening test accuracy, randomized clinical trials (RCTs) of screening or treatment of OSA reporting health outcomes or harms, and systematic reviews of treatment reporting changes in blood pressure and apnea-hypopnea index (AHI) scores. Data Extraction and Synthesis: Dual review of abstracts, full-text articles, and study quality. Meta-analysis of intervention trials. Main Outcomes and Measures: Test accuracy, excessive daytime sleepiness, sleep-related and general health-related quality of life (QOL), and harms. Results: Eighty-six studies were included (N = 11 051). No study directly compared screening with no screening. Screening accuracy of the Multivariable Apnea Prediction score followed by unattended home sleep testing for detecting severe OSA syndrome (AHI ≥30 and Epworth Sleepiness Scale [ESS] score >10) measured as the area under the curve in 2 studies (n = 702) was 0.80 (95% CI, 0.78 to 0.82) and 0.83 (95% CI, 0.77 to 0.90). Five studies assessing the accuracy of other screening tools were heterogeneous and results were inconsistent. Compared with inactive control, positive airway pressure was associated with a significant improvement in ESS score from baseline (pooled mean difference, -2.33 [95% CI, -2.75 to -1.90]; 47 trials; n = 7024), sleep-related QOL (standardized mean difference, 0.30 [95% CI, 0.19 to 0.42]; 17 trials; n = 3083), and general health-related QOL measured by the 36-Item Short Form Health Survey (SF-36) mental health component summary score change (pooled mean difference, 2.20 [95% CI, 0.95 to 3.44]; 15 trials; n = 2345) and SF-36 physical health component summary score change (pooled mean difference, 1.53 [95% CI, 0.29 to 2.77]; 13 trials; n = 2031). Use of mandibular advancement devices was also associated with a significantly larger ESS score change compared with controls (pooled mean difference, -1.67 [95% CI, 2.09 to -1.25]; 10 trials; n = 1540). Reporting of other health outcomes was sparse; no included trial found significant benefit associated with treatment on mortality, cardiovascular events, or motor vehicle crashes. In 3 systematic reviews, positive airway pressure was significantly associated with reduced blood pressure; however, the difference was relatively small (2-3 mm Hg). Conclusions and Relevance: The accuracy and clinical utility of OSA screening tools that could be used in primary care settings were uncertain. Positive airway pressure and mandibular advancement devices reduced ESS score. Trials of positive airway pressure found modest improvement in sleep-related and general health-related QOL but have not established whether treatment reduces mortality or improves most other health outcomes.

Early resistance training-mediated stimulation of daily muscle protein synthetic responses to higher habitual protein intake in middle-aged adults.

KEY POINTS: The ingestion of protein potentiates the stimulation of myofibrillar protein synthesis rates after an acute bout of resistance exercise. Protein supplementation (eating above the protein Recommended Dietary Allowance) during resistance training has been shown to maximize lean mass and strength gains in healthy young and older adults. Here, contractile, oxidative, and structural protein synthesis were assessed in skeletal muscle in response to a moderate or higher protein diet during the early adaptive phase of resistance training in middle-aged adults. The stimulation of myofibrillar, mitochondrial or collagen protein synthesis rates during 0-3 weeks of resistance training is not further enhanced by a higher protein diet. These results show that moderate protein diets are sufficient to support the skeletal muscle adaptive response during the early phase of a resistance training programme. ABSTRACT: Protein ingestion augments muscle protein synthesis (MPS) rates acutely after resistance exercise and can offset age-related loss in muscle mass. Skeletal muscle contains a variety of protein pools, such as myofibrillar (contractile), mitochondrial (substrate oxidation), and collagen (structural support) proteins, and the sensitivity to nutrition and exercise seems to be dependent on the major protein fraction studied. However, it is unknown how free-living conditions with high dietary protein density and habitual resistance exercise mediates muscle protein subfraction synthesis. Therefore, we investigated the effect of moderate (MOD: 1.06 ± 0.22 g kg-1  day-1 ) or high (HIGH: 1.55 ± 0.25 g kg-1  day-1 ) protein intake on daily MPS rates within the myofibrillar (MyoPS), mitochondrial (MitoPS) and collagen (CPS) protein fractions in middle-aged men and women (n = 20, 47 ± 1 years, BMI 28 ± 1 kg m-2 ) during the early phase (0-3 weeks) of a dietary counselling-controlled resistance training programme. Participants were loaded with deuterated water, followed by daily maintenance doses throughout the intervention. Muscle biopsies were collected at baseline and after weeks 1, 2 and 3. MyoPS in the HIGH condition remained constant (P = 1.000), but MOD decreased over time (P = 0.023). MitoPS decreased after 0-3 weeks when compared to 0-1 week (P = 0.010) with no effects of protein intake (P = 0.827). A similar decline with no difference between groups (P = 0.323) was also observed for CPS (P = 0.007). Our results demonstrated that additional protein intake above moderate amounts does not potentiate the stimulation of longer-term MPS responses during the early stage of resistance training adaptations in middle-aged adults.