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BACKGROUND/OBJECTIVES: Hope is a universal, multidimensional, and nuanced concept that may have specific meaning for young people living with chronic health conditions anticipated to last into adulthood. We previously identified definitions of hope for youth living with chronic health conditions derived from young peoples and their caregivers own words. Here, we aimed to develop a hope assessment tool to facilitate the future evaluation of interventions to support wellness and health for young people growing up with chronic health conditions; Methods: We developed Likert-type scale questions using the young peoples and caregivers definitions of hope and applied the think-aloud cognitive interview method to assess understanding and to inform sequential iteration. Interviews were recorded and insights from participant interviews were analyzed thematically. RESULTS: In total, 11 youth (age 12-16 years) with various chronic health conditions completed surveys and interviews over three iteration cycles. Responses to the six-point Likert-scale questions ranged from 1 (none of the time) to 6 (all of the time) (median 5). All of the young people (n = 11) reported that they do things they enjoy, either all of the time or most of the time. In contrast, only 36% felt energetic, either all or most of the time. Three themes were identified: my body and hope; my identity, self-image, and hope; and my world and hope. CONCLUSIONS: In addition to gaining important feedback that allowed us to improve item word choice to maximize assessment tool understanding, we gained valuable insights into the multidimensional construct of hope. Thematic analysis revealed the importance of physical symptoms and identity to the meaning of hope in the context of a young persons life. Our new hope assessment tool derived from the young peoples own definition of hope has face and content validity for use in clinical and research settings to evaluate hope among pediatric patients living with chronic health conditions.

Background/objectiveWe sought to understand healthcare utilization and barriers to care among youth with chronic illness who interact frequently with the healthcare system.MethodsThis was a retrospective analysis of healthcare utilization for youth ≤25 years of age with chronic illness during one calendar year (1 January 2021-31 December 2021) in a single urban academic healthcare system. Inclusion criteria were (1) having at least one healthcare encounter in the calendar year of 2021 and (2) having at least six healthcare encounters over the preceding 3-year period or having a qualifying chronic illness. Demographic and clinical characteristics were collected along with self-reported and derived social determinants of health. Univariable and multivariable regression models were created to identify predictors of missed clinic visits, telehealth use, and activated patient portal accounts.ResultsThe cohort (N = 14,245) was demographically, clinically, and socioeconomically diverse. The youth had frequent clinic visits (median 9, IQR 4-18), multiple subspecialty care referrals (median 4, 1-8), were prescribed multiple medications (median 6, 3-10), and a high proportion received emergency department (18%) or inpatient treatment (15%). Race and public insurance were significant predictors of missed clinic visits and telehealth use. Primary language was a significant predictor of patient portal activation.ConclusionsYouth with chronic illness who are high users of the healthcare system face a high burden of clinic, emergency room, and hospital visits, referrals, and medications. Systematic efforts to lower the healthcare burden and improve care access should address existing racial and socioeconomic disparities affecting this patient population, who are likely to need frequent healthcare over their lifetime.

BackgroundWe report follow-up data from an ongoing prospective cohort study of COVID-19 in pediatric kidney transplantation through the Improving Renal Outcomes Collaborative (IROC).MethodsPatient-level data from the IROC registry were combined with testing, indication, and outcomes data collected to describe the epidemiology of COVID testing, treatment, and clinical outcomes; determine the incidence of a positive COVID-19 test; describe rates of COVID-19 testing; and assess for clinical predictors of a positive COVID-19 test.ResultsFrom September 2020 to February 2021, 21 centers that care for 2690 patients submitted data from 648 COVID-19 tests on 465 patients. Most patients required supportive care only and were treated as outpatients, 16% experienced inpatient care, and 5% experienced intensive care. Allograft complications were rare, with acute kidney injury most common (7%). There was 1 case of respiratory failure and 1 death attributed to COVID-19. Twelve centers that care for 1730 patients submitted complete testing data on 351 patients. The incidence of COVID-19 among patients at these centers was 4%, whereas the incidence among tested patients was 19%. Risk factors to predict a positive COVID-19 test included age > 12 years, symptoms consistent with COVID-19, and close contact with a confirmed case of COVID-19.ConclusionsDespite the increase in testing and positive tests over this study period, the incidence of allograft loss or death related to COVID-19 remained extremely low, with allograft loss or death each occurring in

The definitive treatment for end-stage renal disease is kidney transplantation, which remains limited by organ availability and post-transplant complications. Alternatively, an implantable bioartificial kidney could address both problems while enhancing the quality and length of patient life. An implantable bioartificial kidney requires a bioreactor containing renal cells to replicate key native cell functions, such as water and solute reabsorption, and metabolic and endocrinologic functions. Here, we report a proof-of-concept implantable bioreactor containing silicon nanopore membranes to offer a level of immunoprotection to human renal epithelial cells. After implantation into pigs without systemic anticoagulation or immunosuppression therapy for 7 days, we show that cells maintain >90% viability and functionality, with normal or elevated transporter gene expression and vitamin D activation. Despite implantation into a xenograft model, we find that cells exhibit minimal damage, and recipient cytokine levels are not suggestive of hyperacute rejection. These initial data confirm the potential feasibility of an implantable bioreactor for renal cell therapy utilizing silicon nanopore membranes.

There are limited data on the impact of COVID-19 in children with a kidney transplant (KT). We conducted a prospective cohort study through the Improving Renal Outcomes Collaborative (IROC) to collect clinical outcome data about COVID-19 in pediatric KT patients. Twenty-two IROC centers that care for 2732 patients submitted testing and outcomes data for 281 patients tested for SARS-CoV-2 by PCR. Testing indications included symptoms and/or potential exposures to COVID-19 (N = 134, 47.7%) and/or testing per hospital policy (N = 154, 54.8%). Overall, 24 (8.5%) patients tested positive, of which 15 (63%) were symptomatic. Of the COVID-19-positive patients, 16 were managed as outpatients, six received non-ICU inpatient care and two were admitted to the ICU. There were no episodes of respiratory failure, allograft loss, or death associated with COVID-19. To estimate incidence, subanalysis was performed for 13 centers that care for 1686 patients that submitted all negative and positive COVID-19 results. Of the 229 tested patients at these 13 centers, 10 (5 asymptomatic) patients tested positive, yielding an overall incidence of 0.6% and an incidence among tested patients of 4.4%. Pediatric KT patients in the United States had a low estimated incidence of COVID-19 disease and excellent short-term outcomes.

Many metazoan organs are comprised of branching trees of epithelial tubes; how patterning occurs in these trees is a fundamental problem of development. Commonly, branch tips fill the volume of the organ approximately uniformly, e.g., in mammalian lung, airway branch tips are dispersed roughly uniformly throughout the volume of the lung. In contrast, in the developing metanephric kidney, the tips of the ureteric bud tree are located close to the outer surface of the kidney rather than filling the kidney. Here, we describe a simple alteration in the branching rules that accounts for the difference between the kidney pattern that leads to tips near the organ surface versus previously known patterns that lead to the branch tips being dispersed throughout the organ. We further use a simple toy model to deduce from first principles how this rule change accounts for the differences in the two types of trees.

Active transport by renal proximal tubules plays a significant role in drug disposition. During drug development, estimates of renal excretion are essential to dose determination. Kidney bioreactors that reproduce physiologic cues in the kidney, such as flow-induced shear stress, may better predict in vivo drug behavior than do current in vitro models. In this study, we investigated the role of shear stress on active transport of 4-(4-(dimethylamino)styryl)-N-methylpyridinium iodide (ASP+) by Madin-Darby canine kidney cells exogenously expressing the human organic cation transporters organic cation transporter 2 (OCT2) and multidrug and toxin extrusion protein 1 (MATE1). Cells cultured in a parallel plate under continuous media perfusion formed a tight monolayer with a high barrier to inulin. In response to increasing levels of shear stress (0.2-2 dynes/cm2), cells showed a corresponding increase in transport of ASP+, reaching a maximal 4.2-fold increase at 2 dynes/cm2 compared with cells cultured under static conditions. This transport was inhibited with imipramine, indicating active transport was present under shear stress conditions. Cells exposed to shear stress of 2 dynes/cm2 also showed an increase in RNA expression of both transfected human and endogenous OCT2 (3.7- and 2.0-fold, respectively). Removal of cilia by ammonium sulfate eliminated the effects of shear on ASP+ transport at 0.5 dynes/cm2 with no effect on ASP+ transport under static conditions. These results indicate that shear stress affects active transport of organic cations in renal tubular epithelial cells in a cilia-dependent manner.

Active transport by renal proximal tubules plays a significant role in drug disposition. During drug development, estimates of renal excretion are essential to dose determination. Kidney bioreactors that reproduce physiologic cues in the kidney, such as flow-induced shear stress, may better predict in vivo drug behavior than do current in vitro models. In this study, we investigated the role of shear stress on active transport of 4-(4-(dimethylamino)styryl)-N-methylpyridinium iodide (ASP+) by Madin-Darby canine kidney cells exogenously expressing the human organic cation transporters organic cation transporter 2 (OCT2) and multidrug and toxin extrusion protein 1 (MATE1). Cells cultured in a parallel plate under continuous media perfusion formed a tight monolayer with a high barrier to inulin. In response to increasing levels of shear stress (0.2-2 dynes/cm2), cells showed a corresponding increase in transport of ASP+, reaching a maximal 4.2-fold increase at 2 dynes/cm2 compared with cells cultured under static conditions. This transport was inhibited with imipramine, indicating active transport was present under shear stress conditions. Cells exposed to shear stress of 2 dynes/cm2 also showed an increase in RNA expression of both transfected human and endogenous OCT2 (3.7- and 2.0-fold, respectively). Removal of cilia by ammonium sulfate eliminated the effects of shear on ASP+ transport at 0.5 dynes/cm2 with no effect on ASP+ transport under static conditions. These results indicate that shear stress affects active transport of organic cations in renal tubular epithelial cells in a cilia-dependent manner.

ObjectivesAs acute kidney injury and elevated cumulative fluid balance commonly co-occur in pediatric acute respiratory distress syndrome, we aimed to identify risk factors for their development and evaluate their independent relationships with mortality. We hypothesized that acute kidney injury and elevated cumulative fluid balance would be associated with markers of inflammation and that children with elevated cumulative fluid balance and concomitant acute kidney injury would have worse outcomes than other children.DesignProspective observational study using the pediatric Risk, Injury, Failure, Loss, End-Stage acute kidney injury classification.SettingFive academic PICUs.PatientsTwo-hundred sixty patients 1 month to 18 years old meeting the Berlin definition of acute respiratory distress syndrome between 2008 and 2014.InterventionsNone.Measurements and resultsPICU mortality was 13% (34/260). Relative to survivors, nonsurvivors had greater cumulative fluid balance on day 3 of acute respiratory distress syndrome (+90.1 mL/kg; interquartile range 26.6-161.7 vs +44.9 mL/kg; interquartile range 10.0-111.3; p = 0.008) and also had higher prevalence of acute kidney injury on day 3 of acute respiratory distress syndrome (50% vs 23%; p = 0.001). On stratified analysis, greater cumulative fluid balance on day 3 of acute respiratory distress syndrome was associated with mortality among patients with concomitant acute kidney injury (+111.5 mL/kg for nonsurvivors; interquartile range 82.6-236.8 vs +58.5 mL/kg for survivors; interquartile range 0.9-176.2; p = 0.041) but not among patients without acute kidney injury (p = 0.308). The presence of acute kidney injury on acute respiratory distress syndrome day 3 was associated with mortality among patients with positive cumulative fluid balance (29.1% vs 10.4% mortality; p = 0.001) but not among patients with even or negative cumulative fluid balance (p = 0.430). Day 1 plasma interleukin-6 levels were associated with the development of day 3 positive cumulative fluid balance, day 3 acute kidney injury, and PICU mortality and the association between elevated day 1 interleukin-6 and PICU mortality was partially mediated by the interval development of day 3 positive cumulative fluid balance and day 3 acute kidney injury (p < 0.001).ConclusionsIn pediatric acute respiratory distress syndrome, elevated cumulative fluid balance on day 3 of acute respiratory distress syndrome is associated with mortality specifically in patients with concomitant acute kidney injury. Plasma interleukin-6 levels are associated with the development of positive cumulative fluid balance and acute kidney injury, suggesting a potential mechanism by which inflammation might predispose to mortality.

In many types of tubules, continuity of the lumen is paramount to tubular function, yet how tubules generate lumen continuity in vivo is not known. We recently found that the F-actin-binding protein afadin is required for lumen continuity in developing renal tubules, though its mechanism of action remains unknown. Here, we demonstrate that afadin is required for lumen continuity by orienting the mitotic spindle during cell division. Using an in vitro 3D cyst model, we find that afadin localizes to the cell cortex adjacent to the spindle poles and orients the mitotic spindle. In tubules, cell division may be oriented relative to two axes: longitudinal and apical-basal. Unexpectedly, in vivo examination of early-stage developing nephron tubules reveals that cell division is not oriented in the longitudinal (or planar-polarized) axis. However, cell division is oriented perpendicular to the apical-basal axis. Absence of afadin in vivo leads to misorientation of apical-basal cell division in nephron tubules. Together, these results support a model whereby afadin determines lumen placement by directing apical-basal spindle orientation, resulting in a continuous lumen and normal tubule morphogenesis.

Evaluate laser acupuncture (LA) as an adjuvant therapy in pain management during percutaneous kidney biopsy procedure in children and adolescents. This prospective, double-blinded, randomized controlled trial enrolled patients aged 7 to 26 years admitted to a children's hospital for percutaneous kidney biopsy. Patients received LA to treatment points (acupuncture group) or sham points (control group) before the procedure. The laser delivered a dose of 42 J/cm over 10 acupoints. Patients and parents rated the pain during and after the biopsy, and change in pain scores were calculated for each patient. Anxiety, vital signs, sedation medication, and patient's biopsy experience were secondary outcomes. Sixty-nine treatments (33 in the acupuncture group and 36 in the control group) were eligible for analysis. Patients in the acupuncture group reported a significantly improved change in the pain score after the biopsy compared with the controls (0.8 vs -0.5, P = 0.044). Patients in the acupuncture group had a statistically significant decrease in procedure vital signs including heart rate (-1.8 vs 5.6, P = 0.043) and respiratory rate (-2.4 vs 0.4, P = 0.045) when compared with controls. Parents also perceived a correspondingly greater improvement in their child's pain for those in the acupuncture group compared with the controls (2.3 vs 0.3, P = 0.04). Adjunctive LA significantly improved pain after pediatric percutaneous kidney biopsies.

Most current microfluidic cell culture systems are integrated single use devices. This can limit throughput and experimental design options, particularly for epithelial cells, which require significant time in culture to obtain a fully differentiated phenotype. In addition, epithelial cells require a porous growth substrate in order to fully polarize their distinct apical and basolateral membranes. We have developed a modular microfluidic system using commercially available porous culture inserts to evaluate polarized epithelial cells under physiologically relevant fluid flow conditions. The cell-support for the bioreactor is a commercially available microporous membrane that is ready to use in a 6-well format, allowing for cells to be seeded in advance in replicates and evaluated for polarization and barrier function prior to experimentation. The reusable modular system can be easily assembled and disassembled using these mature cells, thus improving experimental throughput and minimizing fabrication requirements. The bioreactor consists of an apical microfluidic flow path and a static basolateral chamber that is easily accessible from the outside of the device. The basolateral chamber acts as a reservoir for transport across the cell layer. We evaluated the effect of initiation of apical shear flow on short-term intracellular signaling and mRNA expression using primary human renal epithelial cells (HRECs). Ten min and 5 h after initiation of apical fluid flow over a stable monolayer of HRECs, cells demonstrated increased phosphorylation of extracellular signal-related kinase and increased expression of interleukin 6 (IL-6) mRNA, respectively. This bioreactor design provides a modular platform with rapid experimental turn-around time to study various epithelial cell functions under physiologically meaningful flow conditions.

Silicon nanopore membranes (SNMs) with compact geometry and uniform pore size distribution have demonstrated a remarkable capacity for hemofiltration. These advantages could potentially be used for hemodialysis. Here, we present an initial evaluation of the SNM's mechanical robustness, diffusive clearance, and hemocompatibility in a parallel plate configuration. Mechanical robustness of the SNM was demonstrated by exposing membranes to high flows (200 ml/min) and pressures (1,448 mm Hg). Diffusive clearance was performed in an albumin solution and whole blood with blood and dialysate flow rates of 25 ml/min. Hemocompatibility was evaluated using scanning electron microscopy and immunohistochemistry after 4 hours in an extracorporeal porcine model. The pressure drop across the flow cell was 4.6 mm Hg at 200 ml/min. Mechanical testing showed that SNM could withstand up to 775.7 mm Hg without fracture. Urea clearance did not show an appreciable decline in blood versus albumin solution. Extracorporeal studies showed blood was successfully driven via the arterial-venous pressure differential without thrombus formation. Bare silicon showed increased cell adhesion with a 4.1-fold increase and 1.8-fold increase over polyethylene glycol (PEG)-coated surfaces for tissue plasminogen factor (t-PA) and platelet adhesion (CD41), respectively. These initial results warrant further design and development of a fully scaled SNM-based parallel plate dialyzer for renal replacement therapy.

The mucosal epithelium consists of polarized cells with distinct apical and basolateral membranes that serve as functional and physical barriers to external pathogens. The apical surface of the epithelium constitutes the first point of contact between mucosal pathogens, such as Pseudomonas aeruginosa, and their host. We observed that binding of P. aeruginosa aggregates to the apical surface of polarized cells led to the striking formation of an actin-rich membrane protrusion with inverted polarity, containing basolateral lipids and membrane components. Such protrusions were associated with a spatially localized host immune response to P. aeruginosa aggregates that required bacterial flagella and a type III secretion system apparatus. Host protrusions formed de novo underneath bacterial aggregates and involved the apical recruitment of a Par3/Par6α/aPKC/Rac1 signaling module for a robust, spatially localized host NF-κB response. Our data reveal a role for spatiotemporal epithelial polarity changes in the activation of innate immune responses.

Background: Coronavirus disease of 2019 (COVID-19) has disproportionately affected adults with kidney disease. Data regarding outcomes among children with kidney disease are limited. The North American Pediatric Renal Trials Collaborative Studies Registry (NAPRTCS) has followed children with chronic kidney disease (CKD) since 1987 at 87 participating centers. This study aimed to evaluate the impact of COVID-19 among participants enrolled in the three arms of the registry: CKD, dialysis, and transplant. Methods: This was a retrospective cohort study of COVID-19 among participants in the NAPRTCS CKD, dialysis, and transplant registries from 2020 to 2022. Where appropriate, t-tests, chi-square analyses, and univariate logistic regression were used to evaluate the data. Results: The cohort included 1505 NAPRTCS participants with recent data entry; 260 (17%) had documented COVID-19. Infections occurred in all three registry arms, namely, 10% (n = 29) in CKD, 11% (n = 67) in dialysis, and 26% (n = 164) in transplant. The majority of participants (75%) were symptomatic. Hospitalizations occurred in 17% (n = 5) of participants with CKD, 27% (n = 18) maintenance dialysis participants, and 26% (n = 43) of transplant participants. Fourteen percent (n = 4) of CKD participants and 10% (n = 17) of transplant participants developed acute kidney injury (AKI), and a total of eight participants (one CKD, seven transplant) required dialysis initiation. Among transplant participants with moderate to severe illness, 40–43% developed AKI and 29–40% required acute dialysis. There were no reported deaths. Conclusions: COVID-19 was documented in 17% of active NAPRTCS participants. While there was no documented mortality, the majority of participants were symptomatic, and a quarter required hospitalization. [ABSTRACT FROM AUTHOR]

A fundamental process in biology is the de novo formation and morphogenesis of polarized tubules. Although these processes are essential for the formation of multiple metazoan organ systems, little is known about the molecular mechanisms that regulate them. In this study, we have characterized several steps in tubule formation and morphogenesis using the mouse kidney as a model system. We report that kidney mesenchymal cells contain discrete Par3-expressing membrane microdomains that become restricted to an apical domain, coinciding with lumen formation. Once lumen formation has been initiated, elongation occurs by simultaneous extension and additional de novo lumen generation. We demonstrate that lumen formation and elongation require afadin, a nectin adaptor protein implicated in adherens junction formation. Mice that lack afadin in nephron precursors show evidence of Par3-expressing membrane microdomains, but fail to develop normal apical-basal polarity and generate a continuous lumen. Absence of afadin led to delayed and diminished integration of nectin complexes and failure to recruit R-cadherin. Furthermore, we demonstrate that afadin is required for Par complex formation. Together, these results suggest that afadin acts upstream of the Par complex to regulate the integration and/or coalescence of membrane microdomains, thereby establishing apical-basal polarity and lumen formation/elongation during kidney tubulogenesis.

The formation of epithelial tissues requires both the generation of apical-basal polarity and the coordination of this polarity between neighbouring cells to form a central lumen. During de novo lumen formation, vectorial membrane transport contributes to

Development of the nephron requires conversion of the metanephric mesenchyme into tubular epithelial structures with specifically organized intercellular junctions. The nectin proteins area family of transmembrane proteins that dimerize to form intercellular junctional complexes between epithelial cells. In this study, we demonstrate that nectin junctions appear during the earliest stages of epithelial cell morphogenesis in the murine nephron concurrently with the transition of mesenchymal cells into epithelial cells. We have defined the role of nectin during epithelial cell morphogenesis by studying nectin in a three-dimensional culture of Madin-Darby canine kidney (MDCK) cells. In a three-dimensional culture of MDCK cells grown in purified type 1 collagen, expression of a dominant negative form of nectin causes disruption of the formation of cell polarity and disruption of tight junction (TJ) formation, as measured by zonula occludens-1 (ZO-1) localization. In MDCK cells cultured in Matrigel, exogenous expression of nectin-1 causes disruption of normal epithelial cell cyst formation and decreased apoptosis. These data demonstrate that nectins play an important role in normal epithelial cell morphogenesis and may play a role in mesenchyrnal-to-epithelial transition during nephrogenesis by providing an antiapoptotic signal and promoting the formation of TJs and cell polarity. cell polarity; three-dimensional cell culture: PAR-3

Epithelial cells are characterized by the ability to form sheets of cells that surround fluid-filled lumens. Cells in these sheets exhibit a characteristic subcellular polarity, with an apical pole that faces the lumen and a basolateral pole that is in contact with other cells and the extracellular matrix (ECM). To investigate the signaling events required for polarization and lumen formation, we have taken advantage of the ability of Madin-Darby canine kidney (MDCK) cells to dynamically remodel their polarity in response to changes in ECM cues. When MDCK cells are grown in suspension culture, they form multicellular 'inside-out' cysts with apical proteins found on the peripheral surface and basolateral markers on the interior surface. When these inside-out cysts are embedded in ECM, they rapidly reorient their polarity: apical proteins become localized to the inside surface, and basolateral proteins are found on the surface that contacts ECM. Here we have characterized the signaling requirements for these early molecular reorientation events. Specifically, expression of a dominant-negative form of Rac1 (DN-Rac1) blocks the reorientation of polarity. Phosphoinositide 3'-kinase is required for apical membrane protein remodeling from the initial apical membrane surface. Cells expressing DN-Rac1 fail to detectably activate the PI 3-kinase/protein kinase B pathway. Last, we found that atypical protein kinase C (aPKC) is also required for reorientation of polarity, since an inhibitor of atypical PKC blocks reorientation. This effect cannot be overcome by constitutively active Rac1, demonstrating that both Rac1 and atypical PKC are required for reorientation of cellular polarity. cell polarity; three-dimensional cell culture; Rac1; phosphoinositide 3-kinase; atypical protein kinase C