Erythropoietin in children with hemolytic uremic syndrome: a pilot randomized controlled trial.

BACKGROUND: The efficacy of recombinant human erythropoietin (rHuEPO) in sparing red blood cell (RBC) transfusions in children with hemolytic uremic syndrome related to Shiga toxin-producing Escherichia coli (STEC-HUS) is uncertain. METHODS: We conducted a pilot randomized controlled open trial between December 2018 and January 2021. Children were randomized to the intervention (subcutaneous rHuEPO 50 U/kg three times weekly until discharge + RBC transfusion if hemoglobin ≤ 7 g/dL and/or hemodynamic instability) or to the control arm (RBC transfusion if hemoglobin ≤ 7 g/dL and/or hemodynamic instability). Primary outcome was the number of RBC transfusions received during hospitalization. Secondary outcomes were to explore whether baseline EPO levels were adequate to the degree of anemia, to correlate selected acute phase parameters with the number of RBC transfusions, and to assess possible adverse events. RESULTS: Twelve patients per arm were included; they were comparable at recruitment and throughout the disease course. Median number of RBC transfusions was similar between groups (1.5, p = 0.76). Most patients had baseline EPO levels adequate to the degree of anemia, which did not correlate with the number of transfusions (r = 0.19, p = 0.44). Conversely, baseline (r = 0.73, p = 0.032) and maximum lactic dehydrogenase levels (r = 0.78, p = 0.003), creatinine peak (r = 0.71, p = 0.03) and dialysis duration (r = 0.7, p = 0.04) correlated significantly with RBC requirements. No side effects were recorded. CONCLUSION: In children with STEC-HUS, the administration of rHuEPO did not reduce the number of RBC transfusions. Larger studies addressing higher doses and similar severity of kidney failure at rHuEPO initiation (e.g. at start of dialysis) are warranted. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03776851. A higher resolution version of the Graphical abstract is available as Supplementary information.

Prevalencia de Hipertensión Arterial en una unidad de cuidados intensivos neonatales / Prevalence of Arterial Hypertension in a neonatal intensive care unit

INTRODUCCIÓN: La prevalencia de hipertensión arterial neonatal en las unidades de cuidados intensivos neonatales (UCIN) varía entre el 3 y el 9%, sin embargo, no existe información actualizada de Latinoamérica. OBJETIVO: Estimar la prevalencia de hipertensión arterial y evaluar su asociación con causas previa mente relacionadas con esta condición. PACIENTES Y MÉTODO: Estudio transversal que incluyó a todos los niños internados en una UCIN durante un año, excluidos aquellos trasladados a cirugía cardio vascular. Se registraron variables maternas y neonatales, hipertensión arterial materna, vía de parto, edad gestacional, edad, sexo, peso de nacimiento, Apgar, antecedente de maduración pulmonar con corticoides y cateterismo de vasos umbilicales. Se consignó motivo de ingreso a UCIN, medicamen tos y complicaciones durante la hospitalización. La tensión arterial se registró con oscilómetro au tomatizado considerando hipertensión arterial según tablas para edad gestacional. La prevalencia se expresó como porcentaje (intervalo de confianza 95%, IC95%). La estadística descriptiva se presenta como mediana (rango) o frecuencia de presentación (porcentajes) y se buscó asociación con el Test de Wilcoxon, Chi2 o Fisher según correspondiera (p < 0,05). RESULTADOS: Se reclutaron 169 pacientes (60% sexo masculino). Edad gestacional: 38 semanas (rango 26-42), 38% prematuros. Peso 3.000 g (rango 545-4.950), 32% bajo peso. Ocho pacientes presentaron hipertensión arterial (prevalencia 4,7%, IC95% 2,4-9). La presencia de hipertensión arterial se asoció con prematurez (p = 0,0003), bajo peso (p = 0,01), maduración pulmonar con corticoides (p = 0,002), cateterismo umbilical (p = 0,03), uso de ≥ 2 drogas nefrotóxicas (p = 0,02), tratamiento con cafeína (p = 0,0001), injuria renal aguda (p = 0,02) e hipertensión intracraneal (p = 0,04). Solo un paciente requirió medicación antihiper- tensiva y en todos los casos se normalizó durante el seguimiento. CONCLUSIÓN: La prevalencia de hipertensión arterial neonatal fue de 4,7% y en todos los casos se presentó en niños prematuros con factores previamente reconocidos como asociados a esta condición.

INTRODUCTION: The prevalence of neonatal hypertension in neonatal intensive care units (NICU) ranges between 3 and 9%. However, there is no current data on Latin America. Objective: To estimate the prevalence of neonatal hypertension and to assess its association with causes previously related to this condi tion. PATIENTS AND METHOD: cross-sectional study. All patients admitted to the NICU during one year were included, excluding those transferred to the cardiovascular NICU. The following maternal and neonatal variables were registered: maternal arterial hypertension, type of delivery, gestational age, age, sex, birth weight, Apgar score, history of pulmonary maturation with corticosteroids, and umbilical vessel catheterization as well as the reason for admission to the NICU, medications, and complications during hospitalization. Blood pressure was measured with an automated oscillometric device, defining neonatal hypertension according to standards in gestational age. Prevalence was ex pressed as percentage (confidence interval 95%, CI95%). Descriptive data were reported as median (range) and frequency of presentation (percentage). Finally, we used the Wilcoxon, Chi2 o Fisher exact test to identify factors related to NH as applicable (p < 0.05). RESULTS: 169 patients were in cluded (60% males). Gestational age was 38 weeks (range 26-42 weeks), 38% were preterm. Birth weight was 3000 g (range 545-4950 g) and 32% presented low birth weight. Eight patients presented hypertension during hospitalization (4.7% prevalence, CI95% 2.4-9). The presence of hypertension was associated with prematurity (p = 0.0003), low birth weight (p = 0.01), prenatal corticosteroid treatment (p = 0.002), umbilical catheterization (p = 0.03), administration of ὅ 2 nephrotoxic drugs (p = 0.02), caffeine treatment (p = 0.0001), acute kidney injury (p = 0.02), and intracranial hyper tension (p = 0.04). Only one patient required antihypertensive pharmacologic treatment and in all cases, hypertension was resolved during follow-up. CONCLUSION: Prevalence of neonatal hypertension in our NICU was 4.7% and in all cases occurred in preterm newborns with previously recognized factors associated with this condition.

[Prevalence of Arterial Hypertension in a neonatal intensive care unit]. / Prevalencia de Hipertensión Arterial en una unidad de cuidados intensivos neonatales.

INTRODUCTION: The prevalence of neonatal hypertension in neonatal intensive care units (NICU) ranges between 3 and 9%. However, there is no current data on Latin America. OBJECTIVE: To estimate the prevalence of neonatal hypertension and to assess its association with causes previously related to this condi tion. PATIENTS AND METHOD: cross-sectional study. All patients admitted to the NICU during one year were included, excluding those transferred to the cardiovascular NICU. The following maternal and neonatal variables were registered: maternal arterial hypertension, type of delivery, gestational age, age, sex, birth weight, Apgar score, history of pulmonary maturation with corticosteroids, and umbilical vessel catheterization as well as the reason for admission to the NICU, medications, and complications during hospitalization. Blood pressure was measured with an automated oscillometric device, defining neonatal hypertension according to standards in gestational age. Prevalence was ex pressed as percentage (confidence interval 95%, CI95%). Descriptive data were reported as median (range) and frequency of presentation (percentage). Finally, we used the Wilcoxon, Chi2 o Fisher exact test to identify factors related to NH as applicable (p < 0.05). RESULTS: 169 patients were in cluded (60% males). Gestational age was 38 weeks (range 26-42 weeks), 38% were preterm. Birth weight was 3000 g (range 545-4950 g) and 32% presented low birth weight. Eight patients presented hypertension during hospitalization (4.7% prevalence, CI95% 2.4-9). The presence of hypertension was associated with prematurity (p = 0.0003), low birth weight (p = 0.01), prenatal corticosteroid treatment (p = 0.002), umbilical catheterization (p = 0.03), administration of ὅ 2 nephrotoxic drugs (p = 0.02), caffeine treatment (p = 0.0001), acute kidney injury (p = 0.02), and intracranial hyper tension (p = 0.04). Only one patient required antihypertensive pharmacologic treatment and in all cases, hypertension was resolved during follow-up. CONCLUSION: Prevalence of neonatal hypertension in our NICU was 4.7% and in all cases occurred in preterm newborns with previously recognized factors associated with this condition.

Role of Late DMSA Renal Scan in Detecting High-Grade Vesicoureteral Reflux.

OBJECTIVE: To determine the performance of late dimercaptosuccinic acid (DMSA) renal scans in identifying high-grade (III-V) vesicoureteral reflux (VUR) in children aged over 3 y with a febrile urinary tract infection (fUTI) history that has not been timely investigated. METHODS: In this retrospective study of diagnostic accuracy, the clinical records of children aged between 3 and 18 y with fUTI history evaluated consecutively at Nephrology Unit of Hospital General de Niños Pedro de Elizalde, Argentina between 2006 and 2016 were reviewed. Patients with previously diagnosed renal or urinary tract abnormalities or who underwent previous postnatal genitourinary imaging were excluded. Only those assessed by renal and bladder ultrasound (RBUS), voiding cystourethrogram (VCUG) and late 6-mo DMSA scan were analyzed. The ability of the scintigraphy in identifying high-grade VUR was determined by comparing its findings with those of VCUG. RESULTS: In 122 children (median age 5.37 y, 88.5% girls) RBUS was abnormal in 53 (43.4%) and 58 (47.5%) had VUR (30 of high-grade). Abnormal DMSA scan findings (70 patients, 57.4%) were associated with all grade (p = 0.00001) and with high-grade VUR (p = 0.00001). Sensitivity, specificity, negative (NPV) and positive (PPV) predictive values of late DMSA scans for all grades VUR were 93.1%, 75%, 92.3% and 77.1%, respectively. Only 4 patients with low-grade VUR had normal scans. For high-grade VUR, sensitivity and NPV reached 100%. CONCLUSIONS: In older children, the normal late DMSA scan predicted the absence of high-grade VUR, obviating the need for a VCUG. This approach could be a possible strategy for children not studied at acute infection time.

Diagnosis of vesicoureteral reflux according to the 1999 and 2011 guidelines of the Subcommittee on Urinary Tract Infection of the American Academy of Pediatrics.

INTRODUCTION: In 1999, the American Academy of Pediatrics (AAP) recommended perform a renal ultrasonography and avoiding cystourethrography to all infants between 2 and 24 months of age after their first urinary tract infection (UTI). In 2011, the AAP restricted voiding cystourethrography to children with a pathological ultrasonography, recurrent and/ or atypical infections. Our objective was to compare, in patients with vesicoureteral reflux (VUR) and normal renal ultrasonography, the prevalence of a relevant pathology as if patients had been studied as per the 1999 guidelines (for first UTI) or the 2011 guidelines (for recurrent and/or atypical UTI). POPULATION AND METHODS: We conducted a retrospective analysis of patients with UTI, aged between 2 and 24 months old, seen at our department between January 2010 and August 2014 and who had a normal renal ultrasonography and VUR. A relevant pathology was defined as a finding of grade III VUR or higher and/or pathological renal scintigraphy. RESULTS: Forty-five patients (31 girls) were included and were grouped as if they had been treated as per the 1999 or 2011 guidelines. The prevalence of a relevant pathology among patients studied as per the 1999 guidelines (9 out of 24 cases, 3 with atypical UTI) or as per the 2011 guidelines (11 out of 21 cases) was similar (37.5% versus 52%, respectively; p= 0.31). Six patients (25%) with a relevant pathology diagnosed as per the 1999 guidelines would not have been identified in a timely manner with the 2011 version. CONCLUSIONS: The prevalence of a relevant pathology identified in children with VUR and normal renal ultrasonography was similar with both guidelines. However, considering the present guidelines, one out of four patients would have been exposed to a delayed or potentially missed diagnosis if recurrence would have been expected to complete the assessment.

INTRODUCCIÓN: En 1999, la Academia Americana de Pediatría recomendó realizar una ecografía renal y una cistouretrografía miccional a todos los niños de entre 2 y 24 meses con un primer episodio de infección del tracto urinario (ITU). En 2011, limitó la cistouretrografía miccional a aquellos con ecografía patológic infecciones recurrentes y/o atípicas. Nuestro objetivo fue comparar, en pacientes con reflujo vesicoureteral (RVU) y ecografía renal normal, la prevalencia de patología relevante según hubieran sido estudiados con las guías de 1999 (en la primera ITU) o de 2011 (ante ITU recurrente y/o atípica). POBLACIÓN Y MÉTODOS: Estudiamos retrospectivamente pacientes con ITU de entre 2 y 24 meses atendidos entre enero de 2010 y agosto de 2014 con ecografía renal normal y RVU. Consideramos patología relevante al hallazgo de RVU > grado III y/o centellograma renal patológico. RESULTADOS: Incluimos 45 pacientes (31 niñas), que fueron agrupados según hubieran sido estudiados con las guías de 1999 o de 2011. La prevalencia de patología relevante entre los estudiados con las guías de 1999 (9 de 24 casos, 3 con ITU atípica) o de 2011 (11 de 21 casos) fue comparable (37,5% vs. 52%, respectivamente; p= 0,31). Seis pacientes (25%) con patología relevante diagnosticados con las guías de 1999 no se hubieran identificado oportunamente con las de 2011. CONCLUSIONES: La prevalencia de patología relevante identificada en niños con RVU y ecografía renal normal con ambas guías fue comparable. Sin embargo, con las guías actuales, uno de cada cuatro pacientes hubiera estado expuesto a la demora o eventual pérdida diagnóstica si se hubiera esperado la recurrencia para completar la evaluación.

Diagnóstico de reflujo vesicoureteral según las guías de 1999 y de 2011 del Subcomité de Infección Urinaria de la Academia Americana de Pediatría / Diagnosis of vesicoureteral reflux according to the 1999 and 2011 guidelines of the Subcommittee on Urinary Tract Infection of the American Academy of Pediatrics

Introducción. En 1999, la Academia Americana de Pediatría recomendó realizar una ecografía renal y una cistouretrografía miccional a todos los niños de entre 2 y 24 meses con un primer episodio de infección del tracto urinario (ITU). En 2011, limitó la cistouretrografía miccional a aquellos con ecografía patológica, infecciones recurrentes y/o atípicas. Nuestro objetivo fue comparar, en pacientes con reflujo vesicoureteral (RVU) y ecografía renal normal, la prevalencia de patología relevante según hubieran sido estudiados con las guías de 1999 (en la primera ITU) o de 2011 (ante ITU recurrente y/o atípica). Población y métodos. Estudiamos retrospectivamente pacientes con ITU de entre 2 y 24 meses atendidos entre enero de 2010 y agosto de 2014 con ecografía renal normal y RVU. Consideramos patología relevante al hallazgo de RVU > grado III y/o centellograma renal patológico. Resultados. Incluimos 45 pacientes (31 niñas), que fueron agrupados según hubieran sido estudiados con las guías de 1999 o de 2011. La prevalencia de patología relevante entre los estudiados con las guías de 1999 (9 de 24 casos, 3 con ITU atípica) o de 2011 (11 de 21 casos) fue comparable (37,5% vs. 52%, respectivamente; p= 0,31). Seis pacientes (25%) con patología relevante diagnosticados con las guías de 1999 no se hubieran identificado oportunamente con las de 2011. Conclusiones. La prevalencia de patología relevante identificada en niños con RVU y ecografía renal normal con ambas guías fue comparable. Sin embargo, con las guías actuales, uno de cada cuatro pacientes hubiera estado expuesto a la demora o eventual pérdida diagnóstica si se hubiera esperado la recurrencia para completar la evaluación.

Introduction. In 1999, the American Academy of Pediatrics (AAP) recommended perform a renal ultrasonography and avoiding cystourethrography to all infants between 2 and 24 months of age after their first urinary tract infection (UTI). In 2011, the AAP restricted voiding cystourethrography to children with a pathological ultrasonography, recurrent and/ or atypical infections. Our objective was to compare, in patients with vesicoureteral reflux (VUR) and normal renal ultrasonography, the prevalence of a relevant pathology as if patients had been studied as per the 1999 guidelines (for first UTI) or the 2011 guidelines (for recurrent and/or atypical UTI). Population and methods. We conducted a retrospective analysis of patients with UTI, aged between 2 and 24 months old, seen at our department between January 2010 and August 2014 and who had a normal renal ultrasonography and VUR. A relevant pathology was defined as a finding of grade III VUR or higher and/or pathological renal scintigraphy. Results. Forty-five patients (31 girls) were included and were grouped as if they had been treated as per the 1999 or 2011 guidelines. The prevalence of a relevant pathology among patients studied as per the 1999 guidelines (9 out of 24 cases, 3 with atypical UTI) or as per the 2011 guidelines (11 out of 21 cases) was similar (37.5% versus 52%, respectively; p= 0.31). Six patients (25%) with a relevant pathology diagnosed as per the 1999 guidelines would not have been identified in a timely manner with the 2011 version. Conclusions. The prevalence of a relevant pathology identified in children with VUR and normal renal ultrasonography was similar with both guidelines. However, considering the present guidelines, one out of four patients would have been exposed to a delayed or potentially missed diagnosis if recurrence would have been expected to complete the assessment.

Reversal of the extreme coenzyme selectivity of Clostridium symbiosum glutamate dehydrogenase.

Active-site mutants of glutamate dehydrogenase from Clostridium symbiosum have been designed and constructed and the effects on coenzyme preference evaluated by detailed kinetic measurements. The triple mutant F238S/P262S/D263K shows complete reversal in coenzyme selectivity from NAD(H) to NADP(H) with retention of high levels of catalytic activity for the new coenzyme. For oxidized coenzymes, k(cat) /K(m) ratios of the wild-type and triple mutant enzyme indicate a shift in preference of approximately 1.6 × 10(7) -fold, from ∼ 80,000-fold in favour of NAD(+) to ∼ 200-fold in favour of NADP(+). For reduced coenzymes the corresponding figure is 1.7 × 10(4) -fold, from ∼ 1000-fold in favour of NADH to ∼ 17-fold in favour of NADPH. A fourth mutation (N290G), previously identified as having a potential bearing on coenzyme specificity, did not engender any further shift in preference when incorporated into the triple mutant, despite having a significant effect when expressed as a single mutant.

Re-engineering the discrimination between the oxidized coenzymes NAD+ and NADP+ in clostridial glutamate dehydrogenase and a thorough reappraisal of the coenzyme specificity of the wild-type enzyme.

Clostridial glutamate dehydrogenase mutants, designed to accommodate the 2'-phosphate of disfavoured NADPH, showed the expected large specificity shifts with NAD(P)H. Puzzlingly, similar assays with oxidized cofactors initially revealed little improvement with NADP(+) , although rates with NAD(+) were markedly diminished. This article reveals that the enzyme's discrimination in favour of NAD(+) and against NADP(+) had been greatly underestimated and has indeed been abated by a factor of > 16,000 by the mutagenesis. Initially, stopped-flow studies of the wild-type enzyme showed a burst increase of A(340) with NADP(+) but not NAD(+), with amplitude depending on the concentration of the coenzyme, rather than enzyme. Amplitude also varied with the commercial source of the NADP(+). FPLC, HPLC and mass spectrometry identified NAD(+) contamination ranging from 0.04 to 0.37% in different commercial samples. It is now clear that apparent rates of NADP(+) utilization mainly reflected the reduction of contaminating NAD(+), creating an entirely false view of the initial coenzyme specificity and also of the effects of mutagenesis. Purification of the NADP(+) eliminated the burst. With freshly purified NADP(+), the NAD(+) : NADP(+) activity ratio under standard conditions, previously estimated as 300 : 1, is 11,000. The catalytic efficiency ratio is even higher at 80,000. Retested with pure cofactor, mutants showed marked specificity shifts in the expected direction, for example, 16 200 fold change in catalytic efficiency ratio for the mutant F238S/P262S, confirming that the key structural determinants of specificity have been successfully identified. Of wider significance, these results underline that, without purification, even the best commercial coenzyme preparations are inadequate for such studies.