Supported exercise TrAining for Men wIth prostate caNcer on Androgen deprivation therapy (STAMINA): study protocol for a randomised controlled trial of the clinical and cost-effectiveness of the STAMINA lifestyle intervention compared with optimised usual care, including internal pilot and parallel process evaluation.

BACKGROUND: UK national clinical guidance recommends that men with prostate cancer on androgen deprivation therapy are offered twice weekly supervised aerobic and resistance exercise to address iatrogenic harm caused by treatment. Very few NHS trusts have established adequate provision of such services. Furthermore, interventions fail to demonstrate sustained behaviour change. The STAMINA lifestyle intervention offers a system-level change to clinical care delivery addressing barriers to long-term behaviour change and implementation of new prostate cancer care pathways. This trial aims to establish whether STAMINA is clinically and cost-effective in improving cancer-specific quality of life and/or reducing fatigue compared to optimised usual care. The process evaluation aims to inform the interpretation of results and, if the intervention is shown to benefit patients, to inform the implementation of the intervention into the NHS. METHODS: Men with prostate cancer on androgen deprivation therapy (n = 697) will be identified from a minimum of 12 UK NHS trusts to participate in a multi-centre, two-arm, individually randomised controlled trial. Consenting men will have a 'safety to exercise' check and be randomly allocated (5:4) to the STAMINA lifestyle intervention (n = 384) or optimised usual care (n = 313). Outcomes will be collected at baseline, 3-, 6- and 12-month post-randomisation. The two primary outcomes are cancer-specific quality of life and fatigue. The parallel process evaluation will follow a mixed-methods approach to explore recruitment and aspects of the intervention including, reach, fidelity, acceptability, and implementation. An economic evaluation will estimate the cost-effectiveness of the STAMINA lifestyle intervention versus optimised usual care and a discrete choice experiment will explore patient preferences. DISCUSSION: The STAMINA lifestyle intervention has the potential to improve quality of life and reduce fatigue in men on androgen deprivation therapy for prostate cancer. Embedding supervised exercise into prostate cancer care may also support long-term positive behaviour change and reduce adverse events caused by treatment. Findings will inform future clinical care and could provide a blueprint for the integration of supervised exercise and behavioural support into other cancer and/or clinical services. TRIAL REGISTRATION: ISRCTN 46385239, registered on 30/07/2020. Cancer Research UK 17002, retrospectively registered on 24/08/2022.

Parasympathetic and sympathetic control of emmetropization in chick.

Emmetropization can be altered by temporal visual stimulation and the spectral properties of the visual environment. The goal of the current experiment is to test the hypothesis that there is an interaction between these properties and autonomic innervation. For that purpose, selective lesions of the autonomic nervous system were performed in chickens followed by temporal stimulation. Parasympathetic lesioning involved transection of both the ciliary ganglion and the pterygopalatine ganglion (PPG_CGX; n = 38), while sympathetic lesioning involved transection of the superior cervical ganglion (SCGX; n = 49). After one week of recovery, chicks were then exposed to temporally modulated light (3 days, 2 Hz, Mean: 680 lux) that was either achromatic (with blue [RGB], or without blue [RG]), or chromatic (with blue [B/Y] or without blue [R/G]). Control birds with lesions, or unlesioned, were exposed to white [RGB] or yellow [RG] light. Ocular biometry and refraction (Lenstar and a Hartinger refractometer) was measured before and after exposure to light stimulation. Measurements were statistically analyzed for the effects of a lack of autonomic input and the type of temporal stimulation. In PPG_CGX lesioned eyes, there was no effect of the lesions one-week post-surgery. However, after exposure to achromatic modulation, the lens thickened (with blue) and the choroid thickened (without blue) but there was no effect on axial growth. Chromatic modulation thinned the choroid with R/G. In the SGX lesioned eye, there was no effect of the lesion 1-week post-surgery. However, after exposure to achromatic modulation (without blue), the lens thickened and there was a reduction in vitreous chamber depth and axial length. Chromatic modulation caused a small increase in vitreous chamber depth with R/G. Both autonomic lesion and visual stimulation were necessary to affect the growth of ocular components. The bidirectional responses observed in axial growth and in choroidal changes suggest that autonomic innervation combined with spectral cues from longitudinal chromatic aberration may provide a mechanism for homeostatic control of emmetropization.

Mitochondrial Haemoglobin Is Upregulated with Hypoxia in Skeletal Muscle and Has a Conserved Interaction with ATP Synthase and Inhibitory Factor 1.

The globin protein superfamily has diverse functions. Haemoglobin has been found in non-erythroid locations, including within the mitochondria. Using co-immunoprecipitation and in silico methods, we investigated the interaction of mitochondrial haemoglobin with ATP synthase and its associated proteins, including inhibitory factor 1 (IF1). We measured the expression of mitochondrial haemoglobin in response to hypoxia. In vitro and in silico evidence of interactions between mitochondrial haemoglobin and ATP synthase were found, and we report upregulated mitochondrial haemoglobin expression in response to hypoxia within skeletal muscle tissue. Our observations indicate that mitochondrial pH and ATP synthase activity are implicated in the mitochondrial haemoglobin response to hypoxia.

The epidemiology of paediatric burn injuries in Johannesburg, South Africa.

BACKGROUND: Children remain the most common victim of burns in Sub-Saharan Africa. This study describes the epidemiology of paediatric burn injury among patients admitted to Chris Hani Baragwanath Academic Hospital. METHODS: Hospital based cross-sectional, prospective study. RESULTS: 509 patients were admitted to the unit over a 12-month period, with 482 patients included for baseline analysis. 50% of admitted patients were between 15 and 47 months with a median age of 25 months. 58% of participants were male. The predominant mechanism of injury was scalding (84%), in the winter season (32%). The most common site of burn was upper limb (75%). 63% of all admissions received first aid. Among those who received first aid, a described first aid method was provided in 74% of the cases. 226 out of 482 participants (47%) provided sociodemographic information. Access to basic amenities was high, with most admissions coming from households with access to electricity (91%). 90% of caregivers held at least a high school leaving certificate. Migrant caregivers made 19% of the caregivers, which was four times the proportion of foreign nationals counted in the national census. Most admissions (79%) were referrals from other centres as opposed to walk-ins. Severe burns were associated with thermal mechanism of injury, multiple burn sites, and receiving first aid prior to admission. CONCLUSION: Children under two years of age and children of minority groups are at greatest risk for burn injury and should therefore be targeted for injury prevention strategies and education on appropriate first aid. LEVEL OF EVIDENCE: According to the Journal of pediatric Surgery, this research corresponds to Level II evidence as a prospective study with less than 80% follow-up.

Discriminators of pseudoprogression and true progression in high-grade gliomas: A systematic review and meta-analysis.

High-grade gliomas remain the most common primary brain tumour with limited treatments options and early recurrence rates following adjuvant treatments. However, differentiating true tumour progression (TTP) from treatment-related effects or pseudoprogression (PsP), may critically influence subsequent management options. Structural MRI is routinely employed to evaluate treatment responses, but misdiagnosis of TTP or PsP may lead to continuation of ineffective or premature cessation of effective treatments, respectively. A systematic review and meta-analysis were conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses method. Embase, MEDLINE, Web of Science and Google Scholar were searched for methods applied to differentiate PsP and TTP, and studies were selected using pre-specified eligibility criteria. The sensitivity and specificity of included studies were summarised. Three of the identified methods were compared in a separate subgroup meta-analysis. Thirty studies assessing seven distinct neuroimaging methods in 1372 patients were included in the systematic review. The highest performing methods in the subgroup analysis were DWI (AUC = 0.93 [0.91-0.95]) and DSC-MRI (AUC = 0.93 [0.90-0.95]), compared to DCE-MRI (AUC = 0.90 [0.87-0.93]). 18F-fluoroethyltyrosine PET (18F-FET PET) and amide proton transfer-weighted MRI (APTw-MRI) also showed high diagnostic accuracy, but results were based on few low-powered studies. Both DWI and DSC-MRI performed with high sensitivity and specificity for differentiating PsP from TTP. Considering the technical parameters and feasibility of each identified method, the authors suggested that, at present, DSC-MRI technique holds the most clinical potential.

Single-stage procedures for anorectal malformations: A systematic review and meta-analysis.

BACKGROUND: The purpose of this study is to describe all published studies of single-stage procedures for anorectal malformations and to perform a meta-analysis of studies that compared single-stage to staged procedures. METHODS: Searches were conducted in Pubmed, Medline, Embase and CENTRAL. Meta-analysis was performed in RevMan and expressed as forest plots with odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Thirty-eight studies were included in the narrative synthesis. Nine studies were included in the meta-analysis, representing 537 patients. The majority (70%) of patients included in this meta-analysis had either perineal or vestibular fistulas. Surgical site infection (SSI) was defined as any reported infection involving the neoanus (both superficial infection and dehiscence) and occurred in 51 of the 291 patients who underwent single-stage procedures, and 26 of the 244 patients who underwent staged procedure. Meta-analysis showed a 2.2 times higher risk of surgical site infection (SSI) amongst patients who undergo single-stage procedures (OR 2.22, 95% CI 1.26, 3.92). Six of the 293 patients (2%) who underwent single-stage procedures required a rescue ostomy for wound dehiscence. In LMIC the risk of wound dehiscence was three-fold higher in single-stage (36/202) compared to staged procedures (12/126) (OR 3.07, 95% CI 1.42, 6.63). In HIC there was no evidence of an increased risk of wound dehiscence in patients who underwent a single-stage (15/91) compared to a staged procedure (14/118) (OR 1.51, 95% CI 0.65, 3.51). There is no evidence of a difference between single-stage versus staged procedures with regards to functional outcomes including voluntary bowel movements (79/90 versus 111/128), soiling (24/165 versus 20/203) or constipation (27/90 versus 36/128). CONCLUSION: This systematic review provides further evidence that single-stage procedures for selected patients with anorectal malformations are safe. Whilst there is evidence of an increased risk of SSI, this did not translate to a significant difference in long-term functional outcomes. LEVELS OF EVIDENCE: Level II.

Globalization in Pediatric Surgical Training: The Benefit of an International Fellowship in a Low-to-Middle-Income Country Academic Hospital.

OBJECTIVE: A relative oversupply of pediatric surgeons led to increasing difficulties in surgical training in high-income countries (HIC), popularizing international fellowships in low-to-middle-income countries (LMIC). The aim of this study was to evaluate the benefit of an international fellowship in an LMIC for the training of pediatric surgery trainees from HICs. METHODS: We retrospectively reviewed and compared the prospectively maintained surgical logbooks of international pediatric surgical trainees who completed a fellowship at Chris Hani Baragwanath Academic Hospital in the last 10 years. We analyzed the number of surgeries, type of involvement, and level of supervision in the operations. Data are provided in mean differences between South Africa and the respective home country. RESULTS: Seven fellows were included. Operative experience was higher in South Africa in general (Δx̅ = 381; 95% confidence interval [CI]: 236-656; p < 0.0001) and index cases (Δx̅ = 178; 95% CI: 109-279; p < 0.0001). In South Africa, fellows performed more index cases unsupervised (Δx̅ = 71; 95% CI: 42-111; p < 0.0001), but a similar number under supervision (Δx̅ = -1; 95% CI: -25-24; p = 0.901). Fellows were exposed to more surgical procedures in each pediatric surgical subspecialty. CONCLUSION: An international fellowship in a high-volume subspecialized unit in an LMIC can be highly beneficial for HIC trainees, allowing exposure to higher caseload, opportunity to operate independently, and to receive a wider exposure to the different fields of pediatric surgery. The associated benefit for the local trainees is some reduction in their clinical responsibilities due to the additional workforce, providing them with the opportunity for protected academic and research time.

Paediatric Anogenital Condylomata Acuminata: An assessment of patient characteristics and the need for surgical intervention.

BACKGROUND: Anogenital Condylomata Acuminata (AGCA) are caused by Human Papilloma Virus (HPV), which is one of the most common sexually transmitted illnesses in adults. Although commonly seen in the paediatric population, especially in the setting of immunocompromise, literature regarding transmission, viral type and management in this population is scant. The aim of this study was to assess the profile of patients presenting with anogenital warts in light of associated immunocompromise with Human Immunodeficiency Virus (HIV). METHODS: Three years of patient records from Chis Hani Baragwanath Academic Hospital were reviewed (January 2017 - December 2019). Information collected included: gender, age of presentation, age at intervention, type and duration of medical treatment, type and number of surgical interventions, HIV status, and histology results. Fisher's and Pearson's test were used to assess correlation between immune status and surgical interventions necessary. RESULTS: In the time frame considered, we treated 66 patients with AGCA . The average age was 4 years old (1-14). HIV status was recorded in 30 patients (15 positive and 15 negative). Only one patient out of 66 had a history of sexual abuse. Whilst the proportion of patients who required surgical intervention in the HIV negative and HIV positive groups was equal (2:1), the total number of surgical interventions needed to achieve clearance was significantly more in those with HIV (p = 0.03). CONCLUSIONS: HIV positive patients with AGCA require more surgical interventions compared to HIV negative individuals. Further research will be conducted to ascertain the sub-type of HPV infection in this subset of patients and to assess if this impacts follow-up for future malignancy. Further research also needs to be conducted to ascertain whether surgical intervention should be instituted earlier in the treatment protocol for HIV positive children.

Posterior Cloacal Variant with Clitorolabial Transposition and a Rectoperineal Fistula.

We present a case and discuss the management of a posterior cloacal variant not as yet described in the literature. A 5-week-old infant presented to our institution with a posterior cloacal variant and transposition of the clitoris and labia. After initial radiological investigations, staged operative intervention was performed over a 1-year period. This included an initial laparotomy (with drainage of hydrocolpos and formation of a colostomy), a left ureteric reimplantation and a posterior sagittal anorectoplasty due to a rectoperineal fistula. The child is under continued long-term follow-up by our specialist pediatric surgical team.

Treating pediatric colorectal patients in low and middle income settings: Creative adaptation to the resources available.

Colorectal disease profiles for children in low- and middle-income settings (LMIC) are characterized by late presentation, increased complications and limited follow-up in many cases. There is a high prevalence of infectious conditions causing secondary colorectal disease such as Mycobacterium Tuberculosis(TB), Human Immunodeficiency Virus(HIV) and Human Papilloma Virus(HPV), which also impact the management of other primary colorectal conditions, such as wound-healing and intestinal anastomosis. Perineal trauma from sexual assault, motor vehicle or pedestrian accidents, burns, and traditional enemas are commonly encountered and may require adaptation of principles used in treatment of congenital anomalies such as Hirschsprung's disease and Anorectal Malformations for reconstruction. Endemic conditions in certain LMIC require further research to delineate underlying causes and optimize management, such as "African" degenerative visceral leiomyopathy, congenital pouch colon in the Indian subcontinent, and congenital H-type rectal fistulae prevalent in Asia. These unique disease profiles require creative adaptations of resources within poor healthcare infrastructure settings. These special challenges and pitfalls in colorectal care and complications of adverse socioeconomic conditions, are discussed.

Partial catalytic Cys oxidation of human GAPDH to Cys-sulfonic acid.

Background: n-Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) catalyses the NAD +-dependent oxidative phosphorylation of n-glyceraldehyde-3-phosphate to 1,3-diphospho-n-glycerate and its reverse reaction in glycolysis and gluconeogenesis. Methods: Four distinct crystal structures of human n-Glyceraldehyde-3-phosphate dehydrogenase ( HsGAPDH) have been determined from protein purified from the supernatant of HEK293F human epithelial kidney cells. Results: X-ray crystallography and mass-spectrometry indicate that the catalytic cysteine of the protein ( HsGAPDH Cys152) is partially oxidised to cysteine S-sulfonic acid. The average occupancy for the Cys152-S-sulfonic acid modification over the 20 crystallographically independent copies of HsGAPDH across three of the crystal forms obtained is 0.31±0.17. Conclusions: The modification induces no significant structural changes on the tetrameric enzyme, and only makes aspecific contacts to surface residues in the active site, in keeping with the hypothesis that the oxidising conditions of the secreted mammalian cell expression system result in HsGAPDH catalytic cysteine S-sulfonic acid modification and irreversible inactivation of the enzyme.

Potential role of gut microbiota, the proto-oncogene PIKE (Agap2) and cytochrome P450 CYP2W1 in promotion of liver cancer by alcoholic and nonalcoholic fatty liver disease and protection by dietary soy protein.

We have previously demonstrated promotion of diethylnitrosamine (DEN) initiated liver tumorigenesis after feeding diets high in fat or ethanol (EtOH) to male mice. This was accompanied by hepatic induction of the proto-oncogene PIKE (Agap2). Switch of dietary protein from casein to soy protein isolate (SPI) significantly reduced tumor formation in these models. We have linked EtOH consumption in mice to microbial dysbiosis. Adoptive transfer studies demonstrate that microbiota from mice fed ethanol can induce hepatic steatosis in the absence of ethanol suggesting that microbiota or the microbial metabolome play key roles in development of fatty liver disease. Feeding SPI significantly changed gut bacteria in mice increasing alpha diversity (P < 0.05) and levels of Clostidiales spp. Feeding soy formula to piglets also resulted in significant changes in microbiota, the pattern of bile acid metabolites and in inhibition of the intestinal-hepatic FXR/FGF19-SHP pathway which has been linked to both steatosis and hepatocyte proliferation. Moreover, feeding SPI also resulted in induction of hepatic PPARα signaling and inhibition of PIKE mRNA expression coincident with inhibition of steatosis and cancer prevention. Feeding studies in the DEN model with differing dietary fats demonstrated tumor promotion specific to the saturated fat, cocoa butter relative to diets containing olive oil or corn oil associated with microbial dysbiosis including dramatic increases in Lachnospiraceae particularly from the genus Coprococcus. Immunohistochemical analysis demonstrated that tumors from EtOH-fed mice and patients with alcohol-associated HCC also expressed high levels of a novel cytochrome P450 enzyme CYP2W1. Additional adoptive transfer experiments and studies in knockout mice are required to determine the exact relationship between soy effects on the microbiota, expression of PIKE, CYP2W1, PPARα activation and prevention of tumorigenesis.

Devastating Outcomes of Traditional Enemas: Unusual Indications for Well-Known Operations.

Background Despite serious health risks having been described, traditional enemas are still often used in African traditional medicine. We aim to report two cases of complications secondary to traditional enemas, to illustrate how severe the injuries can be, and to describe the use of a Swenson type endoanal pull-through and a posterior sagittal anorectoplasty (PSARP) as surgical options. Case Description A 2-year-old girl presented with a necrotic rectum after a traditional enema administration. At admission, she required a laparotomy, colostomy fashioning, and extensive debridement of her rectum and perineum. She subsequently had a pull-through of the descending colon using a PSARP approach, a covering loop ileostomy, and a Malone Antegrade Continence Enema. The ileostomy was reversed at the age of 3 years of age and she is now clean with rectal washouts. The second case was a one- and a half-year-old boy with full-thickness burns to the perineum and rectum secondary to a hot-water enema. A colostomy was initially brought out and pulled through 7 months post the initial surgery. He is now growing well and is fully continent to stools. Conclusions The potential complications associated with the practice of administering at-home enemas can be quite devastating. A transanal pull-through and a PSARP have been proven to be successful techniques in patients who have suffered rectal burns due to traditional enemas.

Treatment of Urinary Urgency Incontinence Using a Rechargeable SNM System: 6-Month Results of the ARTISAN-SNM Study.

PURPOSE: Sacral neuromodulation is a guideline recommended treatment of urinary dysfunction and fecal incontinence in patients in whom conservative treatments have failed. Historically sacral neuromodulation has been delivered using a nonrechargeable device with an average life span of 4.4 years. Surgery is required to replace the implanted neurostimulator due to battery depletion. Implantation of a long-lived implanted neurostimulator can eliminate the need for replacement surgeries, potentially reducing patient surgical risks and health care costs. The Axonics r-SNM System™ is a miniaturized, rechargeable sacral neuromodulation system designed to deliver therapy for at least 15 years. The ARTISAN-SNM (Axonics® Sacral Neuromodulation System for Urinary Urgency Incontinence Treatment) study is a pivotal study using rechargeable sacral neuromodulation therapy to treat urinary urgency incontinence. Six-month results are presented. MATERIALS AND METHODS: A total of 129 eligible patients with urinary urgency incontinence were treated. All participants were implanted with a tined lead and the rechargeable sacral neuromodulation system in a nonstaged procedure. Efficacy data were collected using a 3-day bladder diary, the validated ICIQ-OABqol (International Consultation on Incontinence Questionnaire Overactive Bladder quality of life) questionnaire and a participant satisfaction questionnaire. Therapy responders were identified as participants with a 50% or greater reduction in urinary urgency incontinence episodes compared to baseline. We performed an as-treated analysis in all implanted participants. RESULTS: At 6 months 90% of participants were therapy responders. The mean ± SE number of urinary urgency incontinence episodes per day was reduced from 5.6 ± 0.3 at baseline to 1.3 ± 0.2. Participants experienced a clinically meaningful 34-point improvement on the ICIQ-OABqol questionnaire. There were no serious device related adverse events. CONCLUSIONS: The Axonics r-SNM System is safe and effective with 90% of participants experiencing clinically and statistically significant improvements in urinary urgency incontinence symptoms.

A reciprocal feedback between the PDZ binding kinase and androgen receptor drives prostate cancer.

Elucidation of mechanisms underlying the increased androgen receptor (AR) activity and subsequent development of aggressive prostate cancer (PrCa) is pivotal in developing new therapies. Using a systems biology approach, we interrogated the AR-regulated proteome and identified PDZ binding kinase (PBK) as a novel AR-regulated protein that regulates full-length AR and AR variants (ARVs) activity in PrCa. PBK overexpression in aggressive PrCa is associated with early biochemical relapse and poor clinical outcome. In addition to its carboxy terminus ligand-binding domain, PBK directly interacts with the amino terminus transactivation domain of the AR to stabilise it thereby leading to increased AR protein expression observed in PrCa. Transcriptome sequencing revealed that PBK is a mediator of global AR signalling with key roles in regulating tumour invasion and metastasis. PBK inhibition decreased growth of PrCa cell lines and clinical specimen cultured ex vivo. We uncovered a novel interplay between AR and PBK that results in increased AR and ARVs expression that executes AR-mediated growth and progression of PrCa, with implications for the development of PBK inhibitors for the treatment of aggressive PrCa.

Analysis of NRAS RNA G-quadruplex binding proteins reveals DDX3X as a novel interactor of cellular G-quadruplex containing transcripts.

RNA G-quadruplexes (rG4s) are secondary structures in mRNAs known to influence RNA post-transcriptional mechanisms thereby impacting neurodegenerative disease and cancer. A detailed knowledge of rG4-protein interactions is vital to understand rG4 function. Herein, we describe a systematic affinity proteomics approach that identified 80 high-confidence interactors that assemble on the rG4 located in the 5'-untranslated region (UTR) of the NRAS oncogene. Novel rG4 interactors included DDX3X, DDX5, DDX17, GRSF1 and NSUN5. The majority of identified proteins contained a glycine-arginine (GAR) domain and notably GAR-domain mutation in DDX3X and DDX17 abrogated rG4 binding. Identification of DDX3X targets by transcriptome-wide individual-nucleotide resolution UV-crosslinking and affinity enrichment (iCLAE) revealed a striking association with 5'-UTR rG4-containing transcripts which was reduced upon GAR-domain mutation. Our work highlights hitherto unrecognized features of rG4 structure-protein interactions that highlight new roles of rG4 structures in mRNA post-transcriptional control.

Supine posture changes lung volumes and increases ventilation heterogeneity in cystic fibrosis.

INTRODUCTION: Lung Clearance Index (LCI) is recognised as an early marker of cystic fibrosis (CF) lung disease. The effect of posture on LCI however is important when considering longitudinal measurements from infancy and when comparing LCI to imaging studies. METHODS: 35 children with CF and 28 healthy controls (HC) were assessed. Multiple breath washout (MBW) was performed both sitting and supine in triplicate and analysed for LCI, Scond, Sacin, and lung volumes. These values were also corrected for the Fowler dead-space to create 'alveolar' indices. RESULTS: From sitting to supine there was a significant increase in LCI and a significant decrease in FRC for both CF and HC (p<0.01). LCI, when adjusted to estimate 'alveolar' LCI (LCIalv), increased the magnitude of change with posture for both LCIalv and FRCalv in both groups, with a greater effect of change in lung volume in HC compared with children with CF. The % change in LCIalv for all subjects correlated significantly with lung volume % changes, most notably tidal volume/functional residual capacity (Vtalv/FRCalv (r = 0.54,p<0.001)). CONCLUSION: There is a significant increase in LCI from sitting to supine, which we believe to be in part due to changes in lung volume and also increasing ventilation heterogeneity related to posture. This may have implications in longitudinal measurements from infancy to older childhood and for studies comparing supine imaging methods to LCI.