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BACKGROUND: Acute kidney injury (AKI) occurs in up to half of infants admitted to the neonatal intensive care unit (NICU) and is associated with increased risks of death and more days of mechanical ventilation, hospitalization, and vasopressor drug support. Our objective was to build a granular relational database to study the impact that AKI has on infants admitted to Level-IV NICUs. METHODS: A relational database was created by linking data from the Children's Hospitals Neonatal Database with AKI-focused data from electronic health records from 9 centers. RESULTS: The current cohort consists of 24,870 infants with a median (IQR) gestational age of birth of 37 weeks (32 weeks, 39 weeks), and a median birth weight of 2.720 kg (1.750 kg, 3.310 kg). There was a male predominance with 14,214 (57%) males. In all, 2434 (9.8%) of the mothers were of Hispanic ethnicity. The maternal race breakdown of the cohort was as follows: 741 (3.0%) Asian, 5911 (24%) Black, and 14,945 (60%) White. Overall mortality was 5.8%. CONCLUSION: The ADVANCE relational database is an innovative research tool to rigorously study the epidemiology of AKI in a large national cohort of infants admitted to Level-IV NICUs involved in the Children's Hospital Neonatal Consortium. IMPACT: We used a biomedical informatics approach to build a relational database to study acute kidney injury in infants. We highlight our methodology linking Children's Hospital Neonatal Consortium and electronic health record data from nine neonatal intensive care units. The ADVANCE relational database is a granular and innovative research tool to study risk factors and in-hospital outcomes of acute kidney injury and mortality in a vulnerable patient population.
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Magnetic resonance imaging (MRI) of the brain is an important diagnostic tool used by neurologists. This article explores the workup and management for a patient with a brain lesion and highlights the importance of neuroimaging. Similarities and differences in MRI findings for meningioma, central nervous system lymphoma, and glioblastomas are discussed, along with common MRI sequences and their utility.
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BACKGROUND: Continuous kidney replacement therapy (CKRT) is often used for acute kidney injury (AKI) or fluid overload (FO) in children ≤ 10 kg. Intensive care unit (ICU) mortality in children ≤ 10 kg reported by the prospective pediatric CRRT (ppCRRT, 2001-2003) registry was 57%. We aimed to evaluate characteristics associated with ICU mortality using a contemporary registry. METHODS: The Worldwide Exploration of Renal Replacement Outcomes Collaborative in Kidney Disease (WE-ROCK) registry is a retrospective, multinational, observational study of children and young adults aged 0-25 years receiving CKRT (2015-2021) for AKI or FO. This analysis included patients ≤ 10 kg at hospital admission. PRIMARY AND SECONDARY OUTCOMES: ICU mortality and major adverse kidney events at 90 days (MAKE-90) defined as death, persistent kidney dysfunction, or dialysis within 90 days, respectively. RESULTS: A total of 210 patients were included (median age 0.53 years (IQR, 0.1, 0.9)). ICU mortality was 46.5%. MAKE-90 occurred in 150/207 (72%). CKRT was initiated at a median 3 days (IQR 1, 9) after ICU admission and lasted a median 6 days (IQR 3, 16). On multivariable analysis, pediatric logistic organ dysfunction score (PELOD-2) at CKRT initiation was associated with increased odds of ICU mortality (aOR 2.64, 95% CI 1.68-4.16), and increased odds of MAKE-90 (aOR 2.2, 95% CI 1.31-3.69). Absence of comorbidity was associated with lower MAKE-90 (aOR 0.29, 95%CI 0.13-0.65). CONCLUSIONS: We report on a contemporary cohort of children ≤ 10 kg treated with CKRT for acute kidney injury and/or fluid overload. ICU mortality is decreased compared to ppCRRT. The extended risk of death and morbidity at 90 days highlights the importance of close follow-up.
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RATIONALE & OBJECTIVE: There are limited studies describing the epidemiology and outcomes in children and young adults receiving continuous kidney replacement therapy (CKRT). We aimed to describe associations between patient characteristics, CKRT prescription, and survival. STUDY DESIGN: Retrospective multicenter cohort study. SETTING & PARTICIPANTS: 980 patients aged from birth to 25 years who received CKRT between 2015 and 2021 at 1 of 32 centers in 7 countries participating in WE-ROCK (Worldwide Exploration of Renal Replacement Outcomes Collaborative in Kidney Diseases). EXPOSURE: CKRT for acute kidney injury or volume overload. OUTCOMES: Death before intensive care unit (ICU) discharge. ANALYTICAL APPROACH: Descriptive statistics. RESULTS: Median age was 8.8 years (IQR, 1.6-15.0), and median weight was 26.8 (IQR, 11.6-55.0) kg. CKRT was initiated a median of 2 (IQR, 1-6) days after ICU admission and lasted a median of 6 (IQR, 3-14) days. The most common CKRT modality was continuous venovenous hemodiafiltration. Citrate anticoagulation was used in 62%, and the internal jugular vein was the most common catheter placement location (66%). 629 participants (64.1%) survived at least until ICU discharge. CKRT dose, filter type, and anticoagulation were similar in those who did and did not survive to ICU discharge. There were apparent practice variations by institutional ICU size. LIMITATIONS: Retrospective design; limited representation from centers outside the United States. CONCLUSIONS: In this study of children and young adults receiving CKRT, approximately two thirds survived at least until ICU discharge. Although variations in dialysis mode and dose, catheter size and location, and anticoagulation were observed, survival was not detected to be associated with these parameters. PLAIN-LANGUAGE SUMMARY: In this large contemporary epidemiological study of children and young adults receiving continuous kidney replacement therapy in the intensive care unit, we observed that two thirds of patients survived at least until ICU discharge. However, patients with comorbidities appeared to have worse outcomes. Compared with previously published reports on continuous kidney replacement therapy practice, we observed greater use of continuous venovenous hemodiafiltration with regional citrate anticoagulation.
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BACKGROUND: Infants with kidney failure (KF) demonstrate poor growth partly due to obligate fluid and protein restrictions. Delivery of liberalized nutrition on continuous kidney replacement therapy (CKRT) is impacted by clinical instability, technical dialysis challenges, solute clearance, and nitrogen balance. We analyzed delivered nutrition and growth in infants receiving CKRT with the Cardio-Renal, Pediatric Dialysis Emergency Machine (Carpediem™). METHODS: Single-center observational study of infants receiving CKRT with the Carpediem™ between June 1 and December 31, 2021. We collected prospective circuit characteristics, delivered nutrition, anthropometric measurements, and illness severity Score for Neonatal Acute Physiology-II. As a surrogate to normalized protein catabolic rate in maintenance hemodialysis, we calculated normalized protein nitrogen appearance (nPNA) using the Randerson II continuous dialysis model. Descriptive statistics, Spearman correlation coefficient, Mann Whitney, Wilcoxon signed rank, receiver operating characteristic curves, and Kruskal-Wallis analysis were performed using SAS version 9.4. RESULTS: Eight infants received 31.9 (22.0, 49.7) days of CKRT using mostly (90%) regional citrate anticoagulation. Delivered nutritional volume, protein, total calories, enteral calories, nPNA, and nitrogen balance increased on CKRT. Using parenteral nutrition, 90 ml/kg/day should meet caloric and protein needs. Following initial weight loss of likely fluid overload, exploratory sensitivity analysis suggests weight gain occurred after 14 days of CKRT. Despite adequate nutritional delivery, goal weight (z-score = 0) and growth velocity were not achieved until 6 months after CKRT start. Most (5 infants, 62.5%) survived and transitioned to peritoneal dialysis (PD). CONCLUSIONS: Carpediem™ is a safe and efficacious bridge to PD in neonatal KF. Growth velocity of infants on CKRT appears delayed despite delivery of adequate calories and protein.
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Lesión Renal Aguda , Terapia de Reemplazo Renal Continuo , Insuficiencia Renal , Lactante , Recién Nacido , Humanos , Niño , Diálisis Renal , Estudios Prospectivos , Estado Nutricional , Insuficiencia Renal/terapia , Nitrógeno/metabolismo , Lesión Renal Aguda/terapiaRESUMEN
While acute kidney injury (AKI) after hematopoietic cell transplant (HCT) has been well-described in pediatric patients, literature regarding the long term renal consequences of HCT-related AKI, the development of chronic kidney disease (CKD), and CKD care in pediatric patients post-HCT is limited. CKD affects almost 50% of patients after HCT with multifactorial etiology including infection, nephrotoxic medications, transplant-associated thrombotic microangiopathy, graft-versus-host disease, and sinusoidal obstruction syndrome. As renal function declines in CKD, eventually progressing to end stage kidney disease (ESKD), mortality increases and is more than 80% among patients requiring dialysis. Using society guidelines and current literature, this review summarizes definitions and etiologies of and management strategies among patients with AKI and CKD post-HCT with an emphasis on albuminuria, hypertension, nutrition, metabolic acidosis, anemia, and mineral bone disease. The goal of this review is to aid early identification and intervention in patients with renal dysfunction prior to development of ESKD, and to discuss ESKD and renal transplant in these patients post-HCT.
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Fallo Renal Crónico , Nefrología , Humanos , Femenino , Embarazo , Diálisis Renal , Feto , Atención PrenatalRESUMEN
Therapeutic apheresis utilizes apheresis procedures in the treatment of a variety of conditions including kidney disease. Therapeutic plasma exchange (TPE) is the most common modality employed with the rationale of rapid reduction of a pathogenic substance distributed primarily in the intravascular compartment; however other techniques which adsorb such pathogenic substances or alter the immune profile have been utilized in diseases affecting native and transplanted kidneys. This article discusses the modalities and technical details of therapeutic apheresis and summarizes its role in individual diseases affecting the kidney. Complications related to pediatric apheresis procedures and specifically related to apheresis in kidney disease are also discussed. Though therapeutic apheresis modalities are employed frequently in children with kidney disease, most experiences are extrapolated from adult studies. International and national registries need to be established to elucidate the role of apheresis modalities in children with kidney disease.
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Eliminación de Componentes Sanguíneos , Enfermedades Renales , Eliminación de Componentes Sanguíneos/efectos adversos , Eliminación de Componentes Sanguíneos/métodos , Niño , Femenino , Humanos , Enfermedades Renales/terapia , Masculino , Intercambio Plasmático/efectos adversos , Intercambio Plasmático/métodos , Sistema de RegistrosRESUMEN
BACKGROUND: Therapeutic plasma exchange (TPE) is used in kidney diseases as an adjunct treatment. Little has been described as to its effectiveness in kidney disorders in children. This study aimed to assess the safety, efficacy, and outcomes of patients who underwent TPE for kidney indications. METHODS: Retrospective chart review of patients receiving TPE from 2010 to 2018 for kidney indications, such as antibody-mediated rejection, bone marrow transplant-associated thrombotic microangiopathy (TA-TMA), atypical hemolytic uremic syndrome, transplant recurrence of focal segmental glomerulosclerosis, and glomerulonephritis. Outcomes assessed were trends in kidney function, mortality, and progression to stage 5 chronic kidney disease (CKD 5). Significant hypocalcemia was defined as ionized calcium < 1 mmol/L. RESULTS: A total of 641 TPE procedures were performed on 47 patients (25 male). Average age was 12.8 ± 5.9 years. Median glomerular filtration rate (GFR) improved from baseline to end of TPE treatments (pre 44.9 (19.8, 79), end 56.1 (23, 98) [p = 0.02]). Ten out of 47 children developed CKD 5. Seven out of 47 patients died; 5 had TA-TMA. Initial 7 consecutive sessions were reviewed for complications. Among 335 procedures, 41 episodes of significant hypocalcemia were noted (12.2%); only 1 was symptomatic. Of the 26 episodes (7.7%) of allergic reactions, all were associated with the use of FFP; 5 were anaphylactic. No TPE-associated mortality was noted. CONCLUSIONS: TPE is a relatively well-tolerated useful adjunct therapy in children with kidney indications. The benefit of TPE has to be balanced with risks such as hypocalcemia and allergic reactions which can occur more frequently with FFP. Graphical abstract.
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Intercambio Plasmático , Adolescente , Niño , Femenino , Humanos , Hipersensibilidad , Hipocalcemia/etiología , Hipocalcemia/terapia , Riñón , Masculino , Insuficiencia Renal Crónica/terapia , Estudios Retrospectivos , Microangiopatías Trombóticas/etiología , Microangiopatías Trombóticas/terapiaRESUMEN
Up-regulation of MMP-2 and MMP-9 plays a significant role in promoting cancer progression by degrading the components of the extracellular matrix, thereby enhancing the migration of tumor cells. Although the antiproliferative and apoptotic effect of Annona muricata is well established, its effect on MMP-2 and MMP-9, a major target in several types of cancers, has not been studied. Powdered samples of various parts of A. muricata like fruit, stem, seed, and twig extracted using aqueous methanol showed significant dose-dependent inhibition of MMP-2 and MMP-9 in a highly metastatic fibrosarcoma cell line, HT1080. Additionally, these extracts also up-regulated the expression of several endogenous inhibitors of MMP-2 and MMP-9 like REversion-inducing Cysteine-rich protein with Kazal motifs (RECK) and Tissue Inhibitor of Metalloproteinase- 2 (TIMP-2). Furthermore, primary cells developed from tumor tissues obtained from patients not exposed to chemotherapy, also exhibited similar results. Remarkably, the inhibition of MMP-2 and MMP-9 observed was tumor specific, with the A. muricata fruit extract showing only 2% inhibition in cells obtained from normal tissues, when compared to 60% inhibition observed in cells obtained from tumor samples. The present study elucidates a novel mechanism by which A. muricata extracts selectively exhibit their anti-cancer activity in tumor cells by down-regulating MMP-2 and MMP-9 that are important biomarkers in cancer.
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Annona/química , Proteínas Ligadas a GPI/genética , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/genética , Inhibidor Tisular de Metaloproteinasa-2/genética , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Matriz Extracelular/efectos de los fármacos , Fibrosarcoma/tratamiento farmacológico , Fibrosarcoma/genética , Fibrosarcoma/patología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Extractos Vegetales/química , Extractos Vegetales/farmacologíaRESUMEN
BACKGROUND: We evaluated the epidemiology of fluid balance (FB) over the first postnatal week and its impact on outcomes in a multi-center cohort of premature neonates from the AWAKEN study. METHODS: Retrospective analysis of infants <36 weeks' gestational age from the AWAKEN study (N = 1007). FB was defined by percentage of change from birth weight. OUTCOME: Mechanical ventilation (MV) at postnatal day 7. RESULTS: One hundred and forty-nine (14.8%) were on MV at postnatal day 7. The median peak FB was 0% (IQR: -2.9, 2) and occurred on postnatal day 2 (IQR: 1,5). Multivariable models showed that the peak FB (aOR 1.14, 95% CI 1.10-1.19), lowest FB in first postnatal week (aOR 1.12, 95% CI 1.07-1.16), and FB on postnatal day 7 (aOR 1.10, 95% CI 1.06-1.13) were independently associated with MV on postnatal day 7. In a similar analysis, a negative FB at postnatal day 7 protected against the need for MV at postnatal day 7 (aOR 0.21, 95% CI 0.12-0.35). CONCLUSIONS: Positive peak FB during the first postnatal week and more positive FB on postnatal day 7 were independently associated with MV at postnatal day 7. Those with a negative FB at postnatal day 7 were less likely to require MV.
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Lesión Renal Aguda/epidemiología , Recien Nacido Prematuro , Equilibrio Hidroelectrolítico , Desequilibrio Hidroelectrolítico/epidemiología , Lesión Renal Aguda/diagnóstico , Lesión Renal Aguda/fisiopatología , Lesión Renal Aguda/terapia , Peso al Nacer , Canadá/epidemiología , Femenino , Transferencias de Fluidos Corporales , Edad Gestacional , Humanos , Recién Nacido , Masculino , Pronóstico , Respiración Artificial , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Estados Unidos/epidemiología , Desequilibrio Hidroelectrolítico/diagnóstico , Desequilibrio Hidroelectrolítico/fisiopatología , Desequilibrio Hidroelectrolítico/terapiaRESUMEN
BACKGROUND: Management of chronic kidney disease mineral bone disorder (CKD-MBD) in pediatric patients with end-stage renal disease (ESRD) is challenging. While the use of calcimimetics is well-studied in adults on dialysis, few studies have been performed in pediatrics. Little is known about the use of cinacalcet in young children with ESRD. The aim of this study was to report the efficacy and safety of cinacalcet for treatment of secondary hyperparathyroidism in chronic dialysis patients younger than 5 years. MATERIALS AND METHODS: We included children aged < 5 years on chronic dialysis, either hemodialysis (HD) or peritoneal dialysis (PD), who were prescribed cinacalcet for more than 1 month. Retrospective chart review was performed to gather demographics, dialysis prescription, relevant mineral imbalance laboratory parameters, and medications. Data was collected for 6 consecutive months. RESULT: 18 patients (9 male), mean age at initiation of cinacalcet was 2.3 years; 13 PD and 5 HD. Average starting dose of cinacalcet: 6.2 mg daily, 0.55 mg/kg/day. Average time on dialysis was 14.4 months. Parathyroid hormone significantly decreased over the 1st month following initiation of cinacalcet from 929 (IQR 572 - 1,056) to 427 (IQR 256 - 778) pg/mL, p = 0.009. Three patients developed asymptomatic hypocalcemia (Ca < 9.4 mg/dL). Serum phosphorous decreased after initiation, and this was persistent at 6 months. Significant improvement in linear growth was observed while on cinacalcet and growth hormone (GH). CONCLUSION: Cinacalcet can be effectively used in young children on dialysis with minimal side effects. Good linear growth was seen in patients on cinacalcet and GH therapy. Long-term large scale data is necessary to confirm. Institution-based management algorithm incorporating cinacalcet would be helpful to maintain uniformity in role of cinacalcet for management of CKD-MBD.
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Calcimiméticos/uso terapéutico , Cinacalcet/uso terapéutico , Hiperparatiroidismo Secundario/tratamiento farmacológico , Fallo Renal Crónico/complicaciones , Preescolar , Femenino , Humanos , Lactante , Masculino , Diálisis Peritoneal , Diálisis Renal , Estudios RetrospectivosRESUMEN
Endogenous costimulatory molecules on T cells such as 4-1BB (CD137) can be leveraged for cancer immunotherapy. Systemic administration of agonistic anti-4-1BB antibodies, although effective preclinically, has not advanced to phase 3 trials because they have been hampered by both dependency on Fcγ receptor-mediated hyperclustering and hepatotoxicity. To overcome these issues, we engineered proteins simultaneously targeting 4-1BB and a tumor stroma or tumor antigen: FAP-4-1BBL (RG7826) and CD19-4-1BBL. In the presence of a T cell receptor signal, they provide potent T cell costimulation strictly dependent on tumor antigen-mediated hyperclustering without systemic activation by FcγR binding. We could show targeting of FAP-4-1BBL to FAP-expressing tumor stroma and lymph nodes in a colorectal cancer-bearing rhesus monkey. Combination of FAP-4-1BBL with tumor antigen-targeted T cell bispecific (TCB) molecules in human tumor samples led to increased IFN-γ and granzyme B secretion. Further, combination of FAP- or CD19-4-1BBL with CEA-TCB (RG7802) or CD20-TCB (RG6026), respectively, resulted in tumor remission in mouse models, accompanied by intratumoral accumulation of activated effector CD8+ T cells. FAP- and CD19-4-1BBL thus represent an off-the-shelf combination immunotherapy without requiring genetic modification of effector cells for the treatment of solid and hematological malignancies.
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Anticuerpos Biespecíficos/metabolismo , Linfocitos T CD8-positivos/metabolismo , Anticuerpos Biespecíficos/inmunología , Linfocitos T CD8-positivos/inmunología , Línea Celular , Proliferación Celular/fisiología , Neoplasias Colorrectales/inmunología , Neoplasias Colorrectales/metabolismo , Humanos , Inmunoterapia , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/metabolismo , Neoplasias/inmunología , Neoplasias/terapiaRESUMEN
BACKGROUND: In sick neonates admitted to the NICU, improper fluid balance can lead to fluid overload. We report the impact of fluid balance in the first postnatal week on outcomes in critically ill near-term/term neonates. METHODS: This analysis includes infants ≥36 weeks gestational age from the Assessment of Worldwide Acute Kidney injury Epidemiology in Neonates (AWAKEN) study (N = 645). Fluid balance: percent weight change from birthweight. PRIMARY OUTCOME: mechanical ventilation (MV) on postnatal day 7. RESULTS: The median peak fluid balance was 1.0% (IQR: -0.5, 4.6) and occurred on postnatal day 3 (IQR: 1, 5). Nine percent required MV at postnatal day 7. Multivariable models showed the peak fluid balance (aOR 1.12, 95%CI 1.08-1.17), lowest fluid balance in 1st postnatal week (aOR 1.14, 95%CI 1.07-1.22), fluid balance on postnatal day 7 (aOR 1.12, 95%CI 1.07-1.17), and negative fluid balance at postnatal day 7 (aOR 0.3, 95%CI 0.16-0.67) were independently associated with MV on postnatal day 7. CONCLUSIONS: We describe the impact of fluid balance in critically ill near-term/term neonates over the first postnatal week. Higher peak fluid balance during the first postnatal week and higher fluid balance on postnatal day 7 were independently associated with MV at postnatal day 7.
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Lesión Renal Aguda/fisiopatología , Equilibrio Hidroelectrolítico , Desequilibrio Hidroelectrolítico/fisiopatología , Lesión Renal Aguda/diagnóstico , Lesión Renal Aguda/mortalidad , Lesión Renal Aguda/terapia , Adulto , Peso al Nacer , Enfermedad Crítica , Femenino , Edad Gestacional , Mortalidad Hospitalaria , Humanos , India , Recién Nacido , Recien Nacido Prematuro , Unidades de Cuidado Intensivo Neonatal , Masculino , América del Norte , Nacimiento Prematuro , Respiración Artificial , Estudios Retrospectivos , Factores de Riesgo , Nacimiento a Término , Factores de Tiempo , Resultado del Tratamiento , Desequilibrio Hidroelectrolítico/diagnóstico , Desequilibrio Hidroelectrolítico/mortalidad , Desequilibrio Hidroelectrolítico/terapia , Aumento de Peso , Adulto JovenRESUMEN
Invasion of erythrocytes by Plasmodial merozoites is a composite process involving the interplay of several proteins. Among them, the Plasmodium falciparum Cysteine-Rich Protective Antigen (PfCyRPA) is a crucial component of a ternary complex, including Reticulocyte binding-like Homologous protein 5 (PfRH5) and the RH5-interacting protein (PfRipr), essential for erythrocyte invasion. Here, we present the crystal structures of PfCyRPA and its complex with the antigen-binding fragment of a parasite growth inhibitory antibody. PfCyRPA adopts a 6-bladed ß-propeller structure with similarity to the classic sialidase fold, but it has no sialidase activity and fulfills a purely non-enzymatic function. Characterization of the epitope recognized by protective antibodies may facilitate design of peptidomimetics to focus vaccine responses on protective epitopes. Both in vitro and in vivo anti-PfCyRPA and anti-PfRH5 antibodies showed more potent parasite growth inhibitory activity in combination than on their own, supporting a combined delivery of PfCyRPA and PfRH5 in vaccines.
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Anticuerpos Antiprotozoarios/química , Anticuerpos Antiprotozoarios/metabolismo , Antígenos de Protozoos/química , Antígenos de Protozoos/metabolismo , Vacunas contra la Malaria/química , Vacunas contra la Malaria/metabolismo , Proteínas Protozoarias/química , Proteínas Protozoarias/metabolismo , Cristalografía por Rayos X , Modelos Moleculares , Unión Proteica , Conformación ProteicaRESUMEN
Fructose-1,6-bisphosphatase (FBPase) is a key regulator of gluconeogenesis and a potential drug target for type 2 diabetes. FBPase is a homotetramer of 222 symmetry with a major and a minor dimer interface. The dimers connected via the minor interface can rotate with respect to each other, leading to the inactive T-state and active R-state conformations of FBPase. Here, the first crystal structure of human liver FBPase in the R-state conformation is presented, determined at a resolution of 2.2â Å in a tetragonal setting that exhibits an unusual arrangement of noncrystallographic symmetry (NCS) elements. Self-Patterson function analysis and various intensity statistics revealed the presence of pseudo-translation and the absence of twinning. The space group is P41212, but structure determination was also possible in space groups P43212, P4122 and P4322. All solutions have the same arrangement of three C2-symmetric dimers spaced by 1/3 along an NCS axis parallel to the c axis located at (1/4, 1/4, z), which is therefore invisible in a self-rotation function analysis. The solutions in the four space groups are related to one another and emulate a body-centred lattice. If all NCS elements were crystallographic, the space group would be I4122 with a c axis three times shorter and a single FBPase subunit in the asymmetric unit. I4122 is a minimal, non-isomorphic supergroup of the four primitive tetragonal space groups, explaining the space-group ambiguity for this crystal.
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Fructosa-Bifosfatasa/química , Hígado/enzimología , Regulación Alostérica , Cristalografía por Rayos X , Humanos , Hígado/química , Modelos Moleculares , Conformación ProteicaRESUMEN
PURPOSE OF REVIEW: Neonatal proteinuria and hematuria while not common can have potentially devastating consequences if left undiagnosed and untreated. It is important to distinguish between inherited and acquired causes of proteinuria to initiate appropriate and timely treatment. With regards to hematuria, it is critical to identify true hematuria from pseudo-hematuria to balance between thorough investigation and unnecessary laboratory work up. This review provides an overview of the common causes of hematuria and proteinuria in a neonate. RECENT FINDINGS: The identification of genetic mutations in nephrotic syndrome has improved our understanding of the role of various proteins that play an important role in maintaining the glomerular filtration barrier. With the advancement in our ability to provide care for extreme premature neonates, the incidence of acute kidney injury has increased in these neonates along with proteinuria and hematuria. SUMMARY: Persistent proteinuria after neonatal acute kidney injury would be of interest in regards to the risk of developing future chronic kidney disease and hypertension.
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Hematuria/etiología , Proteinuria/etiología , Lesión Renal Aguda/complicaciones , Glomerulonefritis/complicaciones , Enfermedades Hematológicas/complicaciones , Humanos , Recién Nacido , Infecciones/complicaciones , Riñón/fisiología , Neoplasias Renales/complicaciones , Síndrome Nefrótico/congénito , Síndrome Nefrótico/diagnóstico , Síndrome Nefrótico/genéticaRESUMEN
This study highlights the benefits of nano electrospray ionization mass spectrometry (nanoESI-MS) as a fast and label-free method not only for determination of dissociation constants (KD) of a cooperatively regulated enzyme but also to better understand the mechanism of enzymatic cooperativity of multimeric proteins. We present an approach to investigate the allosteric mechanism in the binding of inhibitors to the homotetrameric enzyme fructose 1,6-bisphosphatase (FBPase), a potential therapeutic target for glucose control in type 2 diabetes. A series of inhibitors binding at an allosteric site of FBPase were investigated to determine their KDs by nanoESI-MS. The KDs determined by ESI-MS correlate very well with IC50 values in solution. The Hill coefficients derived from nanoESI-MS suggest positive cooperativity. From single-point measurements we could obtain information on relative potency, stoichiometry, conformational changes, and mechanism of cooperativity. A new X-ray crystal structure of FBPase tetramer binding ligand 3 in a 4:4 stoichiometry is also reported. NanoESI-MS-based results match the current understanding of the investigated system and are in agreement with the X-ray structural data, but provide additional mechanistic insight on the ligand binding, due to the better dynamic resolution. This method offers a powerful approach for studying other proteins with allosteric binding sites, as well.
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Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Fructosa-Bifosfatasa/metabolismo , Bibliotecas de Moléculas Pequeñas/química , Bibliotecas de Moléculas Pequeñas/farmacología , Espectrometría de Masa por Ionización de Electrospray/métodos , Regulación Alostérica , Cristalografía por Rayos X , Descubrimiento de Drogas , Fructosa-Bifosfatasa/química , Ligandos , Modelos Moleculares , Unión Proteica , Multimerización de ProteínaRESUMEN
The proximal tubule reabsorbs most of the filtered bicarbonate which is mediated in large part by Na+/H+ exchange (NHE). We have previously demonstrated that there is an isoform switch during postnatal maturation from NHE8 to NHE3 that is concordant with the postnatal increase in serum glucocorticoid levels. To examine if glucocorticoids may be responsible for this isoform switch, we administered dexamethasone daily to mice at 7-10 days of age, a time prior to the normal isoform switch. We show that compared to vehicle treated controls, dexamethasone caused a premature increase in renal NHE3 and decrease in NHE8 mRNA, total protein and brush border membrane protein abundance. To examine if there was a direct epithelial action of dexamethasone on NHE8, we studied NRK cells in vitro which express NHE8 on their apical membrane. Dexamethasone decreased NHE8 mRNA, total protein, and apical protein abundance. Dexamethasone also decreased Na+/H+ exchanger activity. These studies provide evidence that glucocorticoids may play a role in the developmental isoform switch from NHE8 to NHE3 and cause a decrease in NHE8 expression and activity.
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aAMR is a potentially devastating complication of kidney transplantation. The incidence of aAMR in children, while thought to be rare, is not well defined, and there is a paucity of data on treatment regimens in children. We retrospectively reviewed the outcomes of our pediatric patients that were treated for aAMR between 2007 and 2009. Three adolescent Hispanic males were found to have aAMR. All three received deceased donor transplants, and all three verbalized non-adherence. Treatment consisted of rituximab, solumedrol, PE, and IVIgG in one patient, and PE, IVIgG, and bortezomib in two patients. The only side effect of therapy noted was mild hypotension with rituximab that resolved after decreasing the infusion rate. There were no reported infections two yr after treatment, and all of the viral monitoring in these patients remained negative.