Exploring transitions of sewer wastewater infrastructure towards decentralisation using the modular model TURN-Sewers.

We present a new modular model called TURN-Sewers for exploring different adaptations of centralised wastewater infrastructure towards more decentralised wastewater systems under different urban development scenarios. The modular model is flexible and computationally efficient in exploring transitions at the city scale, allowing for the comparison of different policies and management strategies for sanitary wastewater infrastructure. TURN-Sewers includes independent modules that simulate the generation, dimensioning, deterioration, management, and calculation of performance indicators for different wastewater systems. This model can use readily available spatial information to support infrastructure planners and other stakeholders in exploring different transition pathways from centralised to decentralised wastewater infrastructure. An illustrative example demonstrates how TURN-Sewers can generate multiple future alternatives, define different infrastructure management strategies regarding system expansion, rehabilitation and transition, and assess the economic, hydraulic and structural impacts.

When does infrastructure hybridisation outperform centralised infrastructure paradigms? - Exploring economic and hydraulic impacts of decentralised urban wastewater system expansion.

We explore the dynamics of centralised and decentralised wastewater infrastructure across various scenarios and introduce novel insights into their performance regarding structural vulnerability, hydraulic capacity, and costs. This study determines circumstances under which infrastructure hybridisation outperforms traditional centralised infrastructure paradigms. We combined system analysis to map out the modelling problem with the model-based exploration of the transition space using the novel TURN-Sewers model. System diagramming was used to identify the parameters or combinations of parameters that significantly influence the performance indicators being assessed. This allowed the creation of relevant simulation scenarios to identify circumstances where a decentralised sewer system could outperform a centralised one. TURN-Sewers was applied to model the infrastructure maintenance and generation of new infrastructure over 20 years for a municipality on the Swiss Plateau, considering a population growth rate of 0.03 a-1. Results show that decentralisation in expansion areas with higher densification can outperform the hydraulic performance and structural vulnerability of expanding centralised sanitary wastewater infrastructure. Decentralised systems can also offer economic advantages when capital expenditure costs for small-scale wastewater treatment plants are significantly reduced compared to current costs, particularly at higher discount rates, e.g. reaping effects of economies of scale. The findings of this study emphasise the potential of transition pathways towards decentralisation in urban water infrastructures and the value of models that allow the exploration of this transition space.

The Burden of Suboptimal Insulin Dosing in People with Diabetes in Spain: Barriers and Solutions from the Physician Perspective.

Background: This study aimed to determine physicians' perceptions of the extent of suboptimal insulin dosing and the barriers and solutions to optimal dosing in people with diabetes (PwD) treated with insulin. Methods: A cross-sectional online survey was conducted in four countries with primary care physicians and endocrinologists treating PwD using insulin pens, which included 53 questions on physicians' characteristics and their perceptions of the behaviors of PwD in relation to insulin dosing routines, unmet needs and potential solutions. Analyses were descriptive. Results: Of the 160 physicians (80 primary care physicians, 80 specialists) surveyed in Spain, 58.1% were male and 88.8% had been qualified to practice for more than five years. Most physicians (>65%) indicated that 0-30% of PwD missed or skipped, mistimed, or miscalculated an insulin dose in the last 30 days. Common reasons for these actions were that PwD forgot, were out of their normal routine, were too busy or distracted, or were unsure of how much insulin to take. To optimize insulin dosing, over 75% of physicians considered it very helpful for PwD to have real-time insulin dosing calculation guidance, mobile app reminders, a device automatically recording glucose measurements and/or insulin, having insulin and glucose data in one place, and having the time for more meaningful conversations about insulin dosing routines. Conclusion: According to physicians' perspectives, suboptimal insulin dosing remains common among PwD. This survey highlights the need for integrated and automated insulin dosing support to manage the complexity of insulin treatment, improve communications between PwD and physicians, and ultimately improve outcomes for PwD.

Which people with diabetes are treated with a disposable, half-unit insulin pen? A real-world, retrospective, database study in Spain.

INTRODUCTION: Insulin lispro 100 units/mL Jr KwikPen is the first prefilled, disposable, half-unit insulin pen that delivers 0.5-30 units in increments of 0.5 units for the treatment of patients with diabetes. This study describes the profile of patients in Spain who initiated insulin therapy with Jr KwikPen in a real-world setting. METHODS: This retrospective, observational study based on IQVIA's electronic medical records database included patients with Type 1 (T1D) or Type 2 (T2D) diabetes who initiated therapy with Jr KwikPen between May 2018 and December 2020. Sociodemographic, clinical, and treatment characteristics at treatment initiation were analysed descriptively. RESULTS: A total of 416 patients were included. The main characteristics of the T1D/T2D groups (N = 326/90), respectively were as follows: female sex, 61.7%/65.6%; mean age (standard deviation [SD]), 32.5 (20.7)/55.5 (16.6) years; body mass index, 20.9 (4.2)/25.2 (4.6) kg/m2 (N = 239/77); HbA1c, 7.8 (1.7)%/8.0 (1.5)% (N = 141/64); and presence of diabetes-associated comorbidities, 27.9%/64.4%. Only 32.8% of patients with T1D were < 18 years old. Among Jr KwikPen users, 12.3% (T1D/T2D, 7.7%/28.9%) were ≥ 65 years old, 17.1% patients were newly diagnosed, and 3.8% were pregnant women. The mean (SD) total insulin dose pre-index for T1D/T2D was 43.1 (23.6) and 40.7 (21.6) UI/day, respectively. The mean (SD) insulin dose at the start of Jr KwikPen use was 26.63 (16.56) and 22.58 (13.59) UI/day for T1D/T2D, respectively. Jr KwikPen was first prescribed mainly by endocrinologists (58.7%) or paediatricians (22.6%). CONCLUSIONS: The profile of patients who initiated therapy with Jr KwikPen in routine practice was broad with many patients being adults. Most of these patients had T1D, inadequate glycemic control, and multiple associated comorbidities. These results suggest that Jr KwikPen is prescribed in patients who may benefit from finer insulin dose adjustments, namely children, adolescents, adults, older individuals, or pregnant women with T1D or T2D.

Profile of Patients with Diabetes Treated with Insulin Lispro 200 U/ml: A Real-World Study from Spain.

INTRODUCTION: Insulin lispro 200 U/ml (IL200) is a rapid-acting concentrated insulin used for the treatment of adults with diabetes requiring daily doses of > 20 units of rapid-acting insulin. The aim of this study was to describe the clinical/demographic and treatment characteristics of patients who initiated insulin IL200 therapy in Spain in a real-world setting (PROFILE-IL200). METHODS: This retrospective observational study based on the IQVIA database included adult (≥ 18 years) patients with type 1 (T1D) or type 2 (T2D) diabetes who initiated IL200 between June 2015 and December 2019. Demographic and clinical characteristics were analyzed descriptively. RESULTS: Main characteristics for the T1D/T2D groups (N = 65/167) were as follows: male, 63.1/55.7%; mean (standard deviation [SD]) age, 46.5 (15.5)/62.6 (12.8) years; time since first diabetes record, 6.6 (4.2)/7.9 (2.9) years; body mass index (BMI), 30.9 (5.8)/33.1 (5.5) kg/m2; glycated hemoglobin, 8.3 (2.1)/8.8 (1.8)%; and diabetes-associated comorbidity, 55.4/92.8%. Among patients with T1D/T2D and a prior diagnosis (N = 54/164), 96.3/90.2% had received previous insulin (rapid insulin in 81.5/62.2%), and 13.0/97.6% had received previous noninsulin antihyperglycemic therapy. The mean (SD) total insulin dose before IL200 initiation for T1D/T2D was 98.0 (73.9)/95.2 (59.8) U/day; IL200 was initiated at a dose of 56.3 (43.8)/51.5 (34.3) U/day, with basal insulin in 86.2/83.2% of the patients. IL200 was first prescribed by an endocrinologist or a primary care physician in 48.7% and 46.6% of patients, respectively. CONCLUSIONS: PROFILE-IL200 described the profile of patients treated with IL200 in clinical practice in Spain. Patients were middle-aged, with poor glycemic control, high BMI and associated comorbidities, and received high doses of insulin at IL200 initiation.

Insulin is one of the main treatments for people with diabetes. More concentrated versions of a fast-acting insulin such as insulin lispro 200 U/ml (IL200) can be better for people with diabetes who need large daily amounts of a fast-acting insulin to keep their blood glucose at appropriate levels, because the injection volume is smaller, and so one IL200 insulin pen lasts longer than other pens. However, there is limited information on the types of patients who start treatment with this type of insulin in the real world. By using a database of medical records, we studied the profile of patients who started treatment with IL200 between 2015 and 2019 in Spain. The study found that patients starting treatment with IL200 were middle-aged, overweight or obese, and with a poor control of blood glucose levels. The patients also had other conditions common in patients with diabetes, such as high blood pressure, high cholesterol and triglycerides, and heart disease, and were receiving high doses of insulin before starting treatment with IL200. Patients were generally prescribed IL200 by their diabetes specialist or general practitioner. The findings of this study could help identify the patients who may benefit the most from the characteristics of IL200, such as a smaller injection volume and longer duration of use for each insulin pen, which may result in patients using IL200 as directed for longer.

A Simplified Sanitary Sewer System Generator for Exploratory Modelling at City-Scale.

Future climatic, demographic, technological, urban and socio-economic challenges call for more flexible and sustainable wastewater infrastructure systems. Exploratory modelling can help to investigate the consequences of these developments on the infrastructure. In order to explore large numbers of adaptation strategies, we need to re-balance the degree of realism of sewer network and ability to reflect key performance characteristics against the model's parsimony and computational efficiency. We present a spatially explicit algorithm for creating sanitary sewer networks that realistically represent key characteristics of a real system. Basic topographic, demographic and urban characteristics are abstracted into a squared grid of 'Blocks' which are the foundation for the sewer network's topology delineation. We compare three different pipe dimensioning approaches and found a good balance between detail and computational efficiency. With a basic hydraulic performance assessment, we demonstrate that we attain a computationally efficient and high-fidelity wastewater sewer network with adequate hydraulic performance. A spatial resolution of 250 m Block size in combination with a sequential Pipe-by-Pipe (PBP) design algorithm provides a sound trade-off between computational time and fidelity of relevant structural and hydraulic properties for exploratory modelling. We can generate a simplified sewer network (both topology and hydraulic design) in 18 s using PBP, versus 36 min using a highly detailed model or 1 s using a highly abstract model. Moreover, this simplification can cut up to 1/10th to 1/50th the computational time for the hydraulic simulations depending on the routing method implemented. We anticipate our model to be a starting point for sophisticated exploratory modelling into possible infrastructure adaptation measures of topological and loading changes of sewer systems for long-term planning.

Agreement between biopsy and renal function in pediatric patients with lupus nephritis. A retrospective study / Acuerdo entre biopsia y función renal en pacientes pediátricos con nefritis lúpica. Un estudio retrospectivo

ABSTRACT Introduction: Lupus nephritis (LN) is a consequence of Systemic Lupus Erythematosus (SLE). Renal biopsy is a potential prognostic biomarker for renal function. Objective: To correlate histopathological findings and renal function in children with LN. Materials and methods: A retrospective observational study was conducted on children with a histopathological diagnosis of NL. Patients with no follow-up registered were excluded. The kidney biopsy at diagnosis was evaluated using the ISN/RPS scale. The Kappa index was used to determine the level of agreement between renal failure (Glomerular Filtration Rate [GFR] < 60 mL/min/1.73 m2) and presence or absence of each index on the modified ISN/RPS scale. Results: A total of 57 patients with NL were treated from 2011 to 2018 at the institution. Of these, 40 (70%) met inclusion criteria, and 10 (25%) were male. The median age of NL diagnosis was 12.9 years (IQR, 11.1-14.9). Follow-up time was 2.3 years (IQR, 1.0-5.16). At diagnosis, karyorrhexis was the characteristic with highest level of agreement with renal failure (k = 0.1873 SE = 0.0759 P = .0068) and at the last follow-up, it was global segmental sclerosis (k = 0.1481 SE = 0.078 P = .0287). There was no difference in the GFR at the last follow-up and the presence of proteinuria at diagnosis (P = .3936). Conclusion: Renal biopsy findings may be an insufficient tool to predict renal function. Treat ment and prognosis of patients with NL should be done using other biomarkers and clinical signs. Prospective studies should be performed to confirm this hypothesis.

RESUMEN Introducción: La nefritis lúpica (NL) es una consecuencia del lupus eritematoso sistémico (LES). La biopsia renal es un potencial biomarcador de pronóstico de función renal. Objetivo: Correlacionar hallazgos histopatológicos y la función renal de los pacientes pediátricos con la NL. Materiales y métodos: Estudio observacional retrospectivo. Se incluyeron pacientes pediátricos con diagnóstico histopatológico de NL. Se excluyeron pacientes sin seguimiento por la institución. Se evaluó la biopsia renal al diagnóstico con la escala modificada de la International Society of Nephrology and the Renal Pathology Society (ISN/RPS). Se usó el índice kappa para determinar el nivel de acuerdo entre la falla renal (tasa de filtración glomerular [TFG] < 60 mL/min/1,73 m2) y la presencia o ausencia de cada índice de la escala modificada de la ISN/RPS. Resultados: Entre el 2011 y el 2018, 57 pacientes con NL fueron atendidos en la institución, 40 cumplieron con los criterios de inclusión, 10 (25%) eran de sexo masculino. La mediana de edad de diagnóstico de NL fue 12,9 arios (IQR 11,1 a 14,9). El tiempo de seguimiento fue de 2,3 años (IQR 1,0 a 5,16). Al diagnóstico, la cariorexis fue la característica de la escala con mayor nivel de acuerdo con la falla renal (k = 0,1873, EE = 0,0759, p = 0,0068) y al último seguimiento lo fue la esclerosis segmentaria global (k = 0,1481, EE = 0,078, p = 0,0287). No hubo diferencia en la TFG al último seguimiento y presencia de proteinuria al diagnóstico (p = 0,3936). Conclusión: La biopsia renal puede ser insuficiente para evaluar la predicción de la función renal. El tratamiento de pacientes con NL debe realizarse utilizando otros biomarcadores y signos clínicos. Deben hacerse estudios prospectivos que puedan confirmar esta hipótesis.

Nefropatía por inmunoglobulina A en pediatría, desenlaces clínicos con diferentes esquemas de manejo / IgA nephropathy in pediatric patients, clinical outcomes with three types of management

Resumen Introducción: la nefropatía por inmunoglobulina A (NIgA) es la enfermedad glomerular más común en el mundo. En Colombia, el 11-22 % de las glomerulonefritis primarias en niños corresponden a NIgA y de estos casos, el 30 % progresa a enfermedad renal terminal. Objetivo: describir las características paraclínicas e histopatológicas de la NIgA, así como los resultados clínicos según tres tipos de tratamiento en pacientes pediátricos con esta enfermedad atendidos en un hospital de alta complejidad del suroccidente colombiano. Materiales y métodos: estudio retrospectivo realizado en pacientes pediátricos de entre 1 mes y 18 años de edad con diagnóstico de NIgA. Las variables categóricas se presentaron como proporciones y las continuas con medianas y rango intercuartílico. Se usó la prueba de Fisher para comparar los tres esquemas de tratamiento. Resultados: se incluyeron 58 pacientes pediátricos atendidos entre 1996 y 2013. La media de edad al inicio de síntomas fue 7,5±4,2 años y al momento de la biopsia renal, 10±3,8 años. El 77,6 % de los pacientes presentó hematuria microscópica y el 27,6 %, macroscópica. Además, el 81 % tuvo proteinuria, siendo severa el 29 %. Histológicamente, el 10 % se clasificó como grado I, el 62 % como grado II, el 21 % como grado III y el 7 % como grado IV. Tres pacientes requirieron diálisis y dos, trasplante renal. Los esquemas terapéuticos evaluados fueron: solo prednisona (n=20, 34,5 %), prednisona y mofetil micofenolato (MMF) (n=13, 22,4 %) y sin prednisona ni MMF (n=25, 43,1 %). La diferencia en la presencia de hematuria entre los grupos fue significativa (p>0,001), siendo más frecuente en el grupo sin prednisona ni MMF (68 %). No hubo diferencia entre los grupos de proteinuria, hipertensión arterial y valor de creatinina. La mediana de años entre la biopsia renal y el ultimo control fue de 4 años (RIC 1-7). La supervivencia de la función renal fue del 89,1 % a los 5 años. Conclusión: la NIgA amerita reconocimiento temprano y seguimiento estricto, ya que puede tener desenlaces ominosos como enfermedad renal crónica.

Abstract Introduction: IgA nephropathy (IgAN) is the most common glomerular disease in the world, in Colombia belongs to 11-22 % of primary glomerulonephritis in pediatric patients. Of these, 30 % progress to chronic kidney disease. Materials and methods : It is a retrospective descriptive study. We used median and IRQ for continuous variables, and proportions for categorical variables, Fisher test to compare clinical outcomes. Results: Between 1996 to 2013 58 patients were diagnosed. The mean age at symptoms onset was 7.5 years (SD±4.2) and at the time of renal biopsy was 10 years (SD±3.8). At diagnosis, 77.6 % of the patients showed microscopic hematuria, 27.6 % gross hematuria and 81 % proteinuria, classified as severe in 29 %. Three patients required dialysis and two needed kidney transplant. Three groups with different therapeutic regimens were evaluated: first group only prednisone 34.5 % (n = 20), second group prednisone and mycophenolate mofetil (MMF) 22.4 % (n = 13) and third group without prednisone neither MMF 43.1 % (n = 25). The difference in the presence of hematuria among the groups was significant (p> 0.001), being more frequent in the group without prednisone neither MMF (68 %). There were no significant differences in proteinuria, hypertension or creatinine among the groups. The median of years between the renal biopsy and the last control was 4 years RI 1-7. At five years, the renal function survival probability (GFR >90 ml/min/1.73m2) was 89.1 %. Conclusion: IgAN needs early recognition and strict follow-up, since it may have ominous outcomes.

Real-World Use of Insulin Glargine U100 and U300 in Insulin-Naïve Patients with Type 2 Diabetes Mellitus: DosInGlar Study.

INTRODUCTION: In the EDITION clinical trial programme, patients with type 2 diabetes mellitus (T2DM) receiving insulin glargine (IGlar) U300 required 10-15% more insulin than those receiving IGlar U100. This study sought to determine whether this difference was apparent in real-world practice. METHODS: In this observational, retrospective cohort study, electronic medical records in the Big-Pac® database (Real Life Data) relating to adult insulin-naïve patients with T2DM who initiated IGlar U100 or U300 treatment in Spain in 2016-2017 and remained on treatment for 18 months were selected. IGlar U100- and U300-treated patients were matched 1:1 (propensity score matching). The primary analysis compared changes from baseline in mean daily IGlar dose (U and U/kg) at 6 (± 2), 12 (± 2) and 18 (± 2) months between cohorts (paired t tests). Changes in glycated haemoglobin (HbA1c) and weight were analysed descriptively. RESULTS: The IGlar U100 and U300 cohorts included 556 matched pairs (46.9% female) with the following mean (standard deviation) values at baseline, respectively: age 63.6 (12.8) versus 63.7 (11.9) years; years since diagnosis 9.5 (1.4) versus 9.5 (1.3); HbA1c 8.8 (1.3) versus 8.7 (1.5) %; weight 84.6 (16.9) versus 84.7 (17.1) kg. Mean IGlar dose at baseline was 0.19 U/kg/day (both cohorts). Patients receiving IGlar U300 showed a greater increase from baseline in IGlar dose at 6, 12 and 18 months [mean dose (U/kg/day) 5.1%, 10.3% and 12.8% greater, respectively, in IGlar U300-treated patients]. Mean HbA1c was 8.1% in both cohorts at 18 months. Mean (SD) weight at 18 months with IGlar U100 and IGlar300 was 86.8 (17.0) kg and 85.0 (17.1) kg, respectively. CONCLUSION: In real-world practice, insulin dose was significantly higher in IGlar U300-treated than U100-treated patients at 6, 12 and 18 months, with similar reductions in HbA1c. At equal IGlar price/unit in Spain, the increased dose requirements of IGlar U300 would result in higher costs.

New PAX2 Mutation Associated with Polycystic Kidney Disease: A Case Report.

BACKGROUND: Congenital anomalies of the kidney and urinary tract (CAKUT) are the leading cause of end stage renal disease in children. Diagnosis by genetic testing has proven challenging due to its genetic and phenotypic heterogeneity, as well as incomplete penetrance. We report a case on a 16-months old female with a history of renal cysts and a PAX2 mutation. CASE PRESENTATION: The patient presented with a prenatal diagnosis of Potter sequence and a postnatal diagnosis of renal cysts. An ultrasound at 20 weeks gestation revealed right renal agenesis and possible left renal dysplasia. Post natal genetic analyses identified a novel mutation in PAX2. CONCLUSION: Cystic kidney disease is often underdiagnosed due to its variable expressivity and wide range of clinical manifestations; PAX2 genetic screening should be considered for all patients with CAKUT.

Review of the renal endpoints used in cardiovascular safety clinical trials in type 2 diabetes mellitus patients and their importance in primary care.

Chronic kidney disease (CKD) is one of the most common complications of type 2 diabetes mellitus (T2DM). Furthermore, CKD confers a considerable increase in the risk of cardiovascular (CV) morbidity and mortality. In line with the need to improve knowledge in this field, this article aims to describe the renal endpoints used in the different cardiovascular outcome trials (CVOTs). The objective is to better know the renal variables used in the different CVOTs in order to optimize the implementation of advances in the prevention of progressive diabetic kidney disease in patients with T2DM in clinical practice.

Renovascular hypertension secondary to congenital hypoplasia of renal arteries in middle adult patient. About a case / Hipertensión renovascular secundaria a hipoplasia congénita de arterias renales en un paciente adulto joven. A propósito de un caso

Abstract The tubular hypotrophy of the renal arteries constitutes a rare clinical entity, that is associated with the appearance of renovascular hypertension. Its diagnostic approach is complex and requires the availability of angiography to determine the features of the renal vessels. The following case exemplifies the diagnostic process of a patient with this special clinical situation.

Resumen La hipotrofia de aspecto tubular de las arterias renales constituye una rara entidad clínica asociada a la aparición de hipertensión renovascular. Su enfoque diagnóstico es complejo y exige la disponibilidad de angiografía para determinar las características propias del contorno de la vasculature renal. El caso clínico considerado en este artículo ejemplifica el proceso diagnóstico de un paciente con esta particular situación.

Visualization and clustering of sleep states in a frequency domain feature space.

Sleep studies assess the recurrent manifestation of stereotype configurations of relevant biosignals. These configurations are known as states (Wake, REM sleep and NonREM sleep) and stages (N1-N3 within NREM sleep). These two fundamental descriptive domains, time course and variable configuration, can be readily rendered available through improved visualization techniques. Time course is summarized by EEG spectrograms, instantaneous frequency analysis of cardio-respiratory signals and other sleep dependent variables. State and stage configurations can be further evidenced as clusters in 2D or 3D spaces whose axis are sleep-relevant extracted variables. The latter techniques also allows for visualization of transition process as pathways from one cluster to another.

Proapoptotic Fas ligand is expressed by normal kidney tubular epithelium and injured glomeruli.

Fas ligand (FasL) is a cell membrane cytokine that can promote apoptosis through activation of Fas receptors. Fas receptor activation induces glomerular cell apoptosis in vivo and participates in tubular cell death during acute renal failure. However, there is little information on the expression of FasL in the kidney. This study reports that FasL mRNA and protein are present in normal mouse and rat kidney. In situ hybridization and immunohistochemistry showed that proximal tubular epithelium is the main site of FasL expression in the normal kidney. In addition, increased total kidney FasL mRNA and de novo FasL protein expression by glomerular cells were observed in two different models of glomerular injury : rat immune-complex proliferative glumerulonephritis and murine lupus nephritis. Both full-length and soluble FasL were increased in the kidneys of the mice with nephritis. Cultured murine proximal tubular epithelial MCT cells and primary cultures of murine tubular epithelial cells expressed FasL mRNA and protein. Tubular epithelium-derived FasL induced apoptosis in Fassensitive lymphoid cell lines but not in Fas-resistant lymphoid cell lines. By contrast, MCT cells grown in the presence of the survival factors of serum were resistant to FasL, and only became partially sensitive to apoptosis induced by high concentrations (100 ng/ml) of FasL upon serum deprivation. However, MCT cells stimulated with inflammatory mediators (tumor necrosis factor-alpha, interferon-gamma, and lipopolysaccharide) increased cell surface Fas expression and were sensitized to apoptosis induced by FasL (FasL 55 +/- 5% versus control 8.3 +/- 4.1% apoptotic cells at 24 h, P < 0.05). Cytokine-primed primary cultures of tubular epithelial cells also acquired sensitivity to FasL-induced apoptosis. These results suggest that FasL expression by intrinsic renal cells may play a role in cell homeostasis in the normal kidney and during renal injury.