Hypouricemia with hypercalciuria: Longitudinal study and review of the topic.

BACKGROUND AND OBJECTIVE: The association of hypouricemia and hypercalciuria is rare. In 1974 a new syndrome named Hypouricemia with hypercalciuria and decreased bone density was described. Afterwards, some cases with such association were published in which the fractional excretion of urate was higher than 20ml/100ml FGR. We have analyzed a series of children who were diagnosed with hypouricemia and hypercalciuria and who were monitored. The aim of this study was to determine whether our patients could be affected by the aforementioned syndrome or be carriers of a variant of idiopathic hypercalciuria. PATIENTS AND METHODS: Retrospective longitudinal study in which the medical records of eight patients (5V, 3M) diagnosed with hypouricemia and hypercalciuria in childhood. Clinical features at diagnosis, ultrasound and densitometric findings and selected biochemical variables were noted, with special emphasis on renal tubular handling of urate. Results were compared with 36 children with idiopathic hypercalciuria without hypouricemia (14V, 22M). RESULTS: In the hypouricemia group baseline urate levels were 1.9 (0.3) mg/dl (range: 1.5-2) and first day urine calcium/creatinine ratio 0.27 (0.05) mg/mg (range: 0.23-0.31). In all cases fractional urate excretion was less than 20ml/100ml FGR. The z-DMO values were less than -1 in 4/8 cases. At the last follow-up only three cases still had an elevated calcium/creatinine ratio and in all of them the urates levels was greater than 2mg/dl. The z-DMO value had improved in five cases and worsened in three others. In relation to the group without hypouricemia, no differences were observed between the various parameters studied including the z-DMO value, with the exception of fractional excretion and tubular urate reabsorption although plasmatic uric acid levels were still significantly lower. CONCLUSION: Our patients with hypercalciuria and hypouricemia would be affected by a variant of idiopathic hypercalciuria in which, due to an unknown cause, the proximal tubular reabsorption of urate is modestly reduced and improves over time. Hypouricemia with hypercalciuria and decreased bone density may not be a specific entity.

Hipouricemia con hipercalciuria. Estudio longitudinal y revisión del tema / Hypouricemia with hypercalciuria: Longitudinal study and review of the topic

Antecedentes y objetivo: La asociación de hipouricemia e hipercalciuria es poco frecuente. En 1974 se describió un nuevo síndrome nominado Hipouricemia con hipercalciuria y reducción de la densidad ósea. Posteriormente, se publicaron algunos casos con esa asociación en los que la excreción fraccional de urato era superior a 20/100ml FGR. Hemos analizado una serie de niños que fueron diagnosticados de hipouricemia e hipercalciuria y que fueron controlados evolutivamente. El objetivo del trabajo es intentar conocer si nuestros pacientes podrían estar afectos del síndrome antes mencionado o ser portadores de una variante de hipercalciuria idiopática. Pacientes y métodos: Estudio retrospectivo longitudinal en el que se estudiaron las historias clínicas de 8 pacientes (5V y 3M) diagnosticados de hipouricemia e hipercalciuria en la infancia. Se anotaron la clínica al diagnóstico, los hallazgos ecográficos y densitométricos, y determinadas variables bioquímicas, con especial hincapié en el manejo tubular renal del urato. Los resultados se compararon con los de 36 niños afectos de hipercalciuria idiopática sin hipouricemia (14V y 22M). Resultados: En el grupo con hipouricemia los niveles iniciales de uricemia fueron 1,9 (0,3) mg/dl (rango: 1,5-2) y los del cociente calcio/creatinina en primera orina del día, 0,27 (0,05) mg/mg (rango: 0,23-0,31). En todos los casos la excreción fraccional de urato fue inferior a 20ml/100ml FGR. Los valores de z-DMO fueron menores de −1 en 4/8 casos. En el último control, solo en 3 casos persistía el cociente calcio/creatinina elevado, y en todos la uricemia era superior a 2mg/dl. El valor de z-DMO había mejorado en 5 casos y empeorado en otros 3... (AU)

Background and objective: The association of hypouricemia and hypercalciuria is rare. In 1974 a new syndrome named Hypouricemia with hypercalciuria and decreased bone density was described. Afterwards, some cases with such association were published in which the fractional excretion of urate was higher than 20/100ml FGR. We have analyzed a series of children who were diagnosed with hypouricemia and hypercalciuria and who were monitored. The aim of this study was to determine whether our patients could be affected by the aforementioned syndrome or be carriers of a variant of idiopathic hypercalciuria. Patients and methods: Retrospective longitudinal study in which the medical records of eight patients (5V and 3M) diagnosed with hypouricemia and hypercalciuria in childhood. Clinical features at diagnosis, ultrasound and densitometric findings and selected biochemical variables were noted, with special emphasis on renal tubular handling of urate. Results were compared with 36 children with idiopathic hypercalciuria without hypouricemia (14V and 22M). Results: In the hypouricemia group baseline urate levels were 1.9 (0.3)mg/dl (range: 1.5-2) and first day urine calcium/creatinine ratio 0.27 (0.05)mg/mg (range: 0.23-0.31). In all cases fractional urate excretion was less than 20/100ml FGR. The z-DMO values were less than −1 in 4/8 cases. At the last follow-up only three cases still had an elevated calcium/creatinine ratio and in all of them the urates levels was greater than 2mg/dl. The z-DMO value had improved in five cases and worsened in three others. In relation to the group without hypouricemia, no differences were observed between the various parameters studied including the z-DMO value, with the exception of fractional excretion and tubular urate reabsorption although plasmatic uric acid levels were still significantly lower... (AU)

Entrenamiento de la marcha con la cinta rodante antigravitatoria en pacientes con Parkinson / Gait training with the anti-gravity treadmill in Parkinson's patients / Treinamento de marcha com fita rolante antigravitatoria em pacientes com Parkinson

La enfermedad de Parkinson (EP) es una condición neurodegenerativa caracterizada por alteraciones motoras que afectan principalmente el desarrollo de la marcha, produciéndose generalmente el fenómeno del congelamiento de la marcha con la posibilidad del riesgo de caída. Objetivo: Analizar los beneficios del entrenamiento de la marcha con la cinta rodante antigravitatoria en pacientes con EP. Materiales y métodos: Es un estudio pre-experimental con un solo grupo de intervención. Se llevó a cabo el entrenamiento de la marcha a través de una cinta rodante antigravitatoria (AlterG) durante un mes dividido en 2 sesiones por semana. Los parámetros de la marcha arrojados por el equipo AlterG fueron la descarga de peso, cadencia, tiempo de apoyo y longitud del paso; además se valoró el congelamiento de la marcha con el cuestionario (FOGQ) y el riesgo de caída con el test Timed Up and Go (TUG). Resultados: En los parámetros de la marcha y en el FOGQ se encontró diferencias significativas (p<0,05) entre los valores de pre y post intervención, exceptuando a la variable cadencia. El riesgo de caída disminuyó 4,6 y 4,3 segundos promedio en el test TUG en hombres y mujeres respectivamente. Conclusión: El entrenamiento de la marcha en la cinta rodante antigravitatoria mejora las condiciones de la marcha y reduce el riesgo de caídas en pacientes con EP.

Parkinson's disease (PD) is a neurodegenerative condition characterized by motor alterations that mainly affect the development of gait, generally producing the phenomenon of freezing of gait with the possibility of risk of falling. Objective: To analyze the benefits of gait training with the antigravity treadmill in patients with PD. Materials and methods: It is a pre-experimental study with a single intervention group. Gait training was carried out using an antigravity treadmill (AlterG) for one month divided into 2 sessions per week. The gait parameters returned by the AlterG team were weight unloading, cadence, support time and step length; Furthermore, freezing of gait was assessed with the questionnaire (FOGQ) and the risk of falling with the Timed Up and Go test (TUG). Results: In the gait parameters and in the FOGQ, significant differences (p<0.05) were found between the pre- and post-intervention values, except for the cadence variable. The risk of falling decreased by 4.6 and 4.3 seconds on average in the TUG test in men and women respectively. Conclusion: Antigravity treadmill gait training improves walking conditions and reduces the risk of falls in PD patients.

A doença de Parkinson (DP) é uma condição neurodegenerativa caracterizada por alterações motoras que afetam principalmente o desenvolvimento da marcha, geralmente produzindo o fenômeno de congelamento da marcha com possibilidade de risco de queda. Objetivo: Analisar os benefícios do treino de marcha com esteira antigravitacional em pacientes com DP. Materiais e métodos: Trata-se de um estudo pré-experimental com um único grupo de intervenção. O treinamento de marcha foi realizado em esteira antigravitacional (AlterG) durante um mês dividido em 2 sessões semanais. Os parâmetros de marcha retornados pela equipe AlterG foram descarga de peso, cadência, tempo de apoio e comprimento do passo; Além disso, o congelamento da marcha foi avaliado com o questionário (FOGQ) e o risco de queda com o teste Timed Up and Go (TUG). Resultados: Nos parâmetros da marcha e no FOGQ foram encontradas diferenças significativas (p<0,05) entre os valores pré e pós-intervenção, exceto na variável cadência. O risco de queda diminuiu em média 4,6 e 4,3 segundos no teste TUG em homens e mulheres respectivamente. Conclusão: O treino de marcha em esteira antigravitacional melhora as condições de marcha e reduz o risco de quedas em pacientes com DP.

Evaluación del riesgo de caídas en adultos mayores con Diabetes Mellitus tipo 2 / Evaluation of fall risk assessmentin in older adults with Type 2 Diabetes Mellitus / Avaliação do risco de quedas em idosos com Diabetes Mellitus tipo 2

Introducción: La diabetes mellitus 2 es una enfermedad frecuente en adultos mayores, con múltiples complicaciones que pueden llegar a afectar el equilibrio y la marcha e incrementar el riesgo de caída. Objetivo: Determinar el riesgo de caídas en dos grupos de adultos mayores, uno con padecimiento de DM2 y otro sin este padecimiento. Metodología: Estudio de enfoque cuantitativo, alcance descriptivo, diseño observacional, y de cohorte transversal; muestra poblacional de 120 adultos mayores en la ciudad de Guayaquil divididos en dos grupos: grupo A con 60 adultos mayores que no padecían DM2 y grupo B con 60 adultos mayores con DM2; que cumplen con los criterios de inclusión y a quienes se evalúan mediante las técnicas: observación, evaluación y entrevista; y los instrumentos: Escala de Berg, Mini-BESTest y formulario estándar. Se utilizó la prueba estadística Chi cuadrado para la comparación de los resultados obtenidos. Resultados: Los resultados indican que, en la determinación del riesgo de caídas, se encontraron diferencias estadísticamente significativas (p0.05). El estudio además encontró que los resultados obtenidos, en las dos pruebas de riesgo de caídas, difieren entre sí. Conclusiones: Los adultos mayores diabéticos presentan un mayor riesgo de caída a comparación de adultos mayores no diabéticos.

Introduction: Diabetes mellitus 2 is a common disease in older adults, with multiple complications that can affect balance and gait and increase the risk of falling. Objective: To determine the risk of falls in two groups of older adults, one with and the other without DM2. Methodology: Quantitative approach study, descriptive scope, observational design, and cross-sectional cohort; population sample of 120 older adults in the city of Guayaquil divided into two groups: group A with 60 older adults who did not suffer from DM2 and group B with 60 older adults with DM2; who meet the inclusion criteria and who are evaluated by means of the techniques: observation, evaluation and interview; and the instruments: Berg scale, Mini-BESTestest and standard form. The Chi-square statistical test was used to compare the results obtained. Results: The results indicate that, in the determination of the risk of falls, statistically significant differences (p0.05) were found. The study further found that the results obtained, in the two fall risk tests, differed from each other. Conclusions: Diabetic older adults present a higher risk of falling compared to non-diabetic older adults.

Introdução: O diabetes mellitus tipo 2 é uma doença comum em idosos, com múltiplas complicações que podem afetar o equilíbrio e a marcha e aumentar o risco de quedas. Objetivo: Determinar o risco de quedas em dois grupos de idosos, um com DM2 e outro sem essa condição. Metodologia: Estudo com abordagem quantitativa, escopo descritivo, desenho observacional e coorte transversal; amostra populacional de 120 idosos da cidade de Guayaquil dividida em dois grupos: grupo A com 60 idosos que não sofriam de DM2 e grupo B com 60 idosos com DM2; que atendam aos critérios de inclusão e que sejam avaliados pelas técnicas: observação, avaliação e entrevista; e os instrumentos: Escala de Berg, Mini-BESTest e formulário padrão. O teste estatístico Qui-quadrado foi utilizado para comparação dos resultados obtidos. Resultados: Os resultados indicam que, na determinação do risco de quedas, foram encontradas diferenças estatisticamente significativas (p0,05). O estudo também constatou que os resultados obtidos nos dois testes de risco de queda diferem entre si. Conclusões: Idosos diabéticos apresentam maior risco de queda em comparação aos idosos não diabéticos.

Renal diseases that course with hypomagnesemia. Comments on a new hereditary hypomagnesemic tubulopathy.

Renal diseases associated with hypomagnesemia are a complex and diverse group of tubulopathies caused by mutations in genes encoding proteins that are expressed in the thick ascending limb of the loop of Henle and in the distal convoluted tubule. In this paper, we review the initial description, the clinical expressiveness and etiology of four of the first hypomagnesemic tubulopathies described: type 3 Bartter and Gitelman diseases, Autosomal recessive hypomagnesemia with secondary hypocalcemia and Familial hypomagnesemia with hypercalciuria and nephrocalcinosis. The basic biochemical patterns observed in renal tubular hypomagnesemias and the modalities of transport and interaction that occur between the transporters involved in the reabsorption of magnesium in the distal convoluted tubule are described below. Finally, the recent report of a new renal disease with hypomagnesemia, type 2 hypomagnesemia with secondary hypocalcemia caused by reduced TRPM7 channel activity is described.

Enfermedades renales que cursan con hipomagnesemia. Comentarios acerca de una nueva tubulopatía hipomagnesémica de origen genético / Renal diseases that course with hypomagnesemia. Comments on a new hereditary hypomagnesemic tubulopathy

Las enfermedades renales que cursan con hipomagnesemia son un grupo complejo y variopinto de tubulopatías producidas por mutaciones en genes que codifican proteínas que se expresan en la rama gruesa ascendente del asa de Henle y en el túbulo contorneado distal. En el presente artículo revisamos la descripción inicial, la expresividad clínica y la etiología de cuatro de las primeras causas de tubulopatías hipomagnesémicas que se describieron: las enfermedades de Bartter tipo 3 y Gitelman, la hipomagnesemia con hipocalcemia secundaria autosómica recesiva y la hipomagnesemia familiar con hipercalciuria y nefrocalcinosis. A continuación, se describen los patrones bioquímicos básicos que se observan en las hipomagnesemias tubulares renales y las modalidades de transporte e interacción que concurren entre los transportadores implicados en la reabsorción de magnesio en el túbulo contorneado distal. Finalmente, se comunica la reciente descripción de una nueva tubulopatía hipomagnesémica, la hipomagnesemia con hipocalcemia secundaria tipo 2 causada por una reducción de la actividad del canal TRPM7 (AU)

Renal diseases associated with hypomagnesemia are a complex and diverse group of tubulopathies caused by mutations in genes encoding proteins that are expressed in the thick ascending limb of the loop of Henle and in the distal convoluted tubule. In this paper, we review the initial description, the clinical expressiveness and etiology of four of the first hypomagnesemic tubulopathies described: Type 3 Bartter and Gitelman diseases,Autosomal recessive hypomagnesemia with secondary hypocalcemia and Familial hypomagnesemia with hypercalciuria and nephrocalcinosis. The basic biochemical patterns observed in renal tubular hypomagnesemias and the modalities of transport and interaction that occur between the transporters involved in the reabsorption of magnesium in the distal convoluted tubule are described below. Finally, the recent report of a new renal disease with hypomagnesemia, Type 2 hypomagnesemia with secondary hypocalcemia caused by reduced TRPM7 channel activity is described (AU)

II Congreso Nacional de Pediatría. La lucha contra la mortalidad infantil / II National Congress of Paediatrics: The fight against child mortality

En el presente trabajo se presenta una aproximación a los contenidos de las ponencias del IICongreso Nacional de Pediatría, celebrado en San Sebastián en 1923, con ocasión del centenario del mismo. Se destaca como hilo conductor de las mismas el problema de la mortalidad infantil, que en aquellos años era muy elevada en España y era una preocupación de políticos, de intelectuales y de la clase médica. Se constata que alguna de las propuestas y preocupaciones de los pediatras que asistieron a dicho congreso siguen vigentes hoy en día.(AU)

In this work, we present an overview of the contents of the communications presented at the Second National Congress of Paediatrics, held in San Sebastian in 1923, on the occasion of the 100th year anniversary. The problem of infant mortality stands out as a common thread, which in those years was very high in Spain and was a concern of politicians, intellectuals and the medical profession. It is worth noting that some of the proposals and concerns of the paediatricians who attended that congress continue to be relevant today.(AU)

II National Congress of Paediatrics: The fight against child mortality.

In the present work, we present an overview of the contents of the communications presented at the Second National Congress of Paediatrics, held in San Sebastian in 1923, on the occasion of the 100th year anniversary. The problem of infant mortality stands out as a common thread, which in those years was very high in Spain and was a concern of politicians, intellectuals and the medical profession. It is worth noting that some of the proposals and concerns of the paediatricians who attended that congress continue to be relevant today.

Uso de dispositivos móviles y alteraciones cervicales en estudiantes universitarios / Use of mobile devices and cervical disorders in university students / Uso de dispositivos móveis e distúrbios cervicais em estudantes universitários

Las alteraciones cervicales son un problema multifactorial que afecta a la sociedad moderna. Posturas viciosas, traumatismos y defectos congénitos relacionados con la columna cervical pueden desarrollar inestabilidad, pinzamiento radicular, cervicoartrosis y cervicalgias. Objetivo. Relacionar el uso de dispositivos móviles con las alteraciones cervicales en estudiantes universitarios. Materiales y métodos. Estudio descriptivo, observacional, que se realizó entre los meses de mayo y julio del 2023, cuya muestra fue de 172 estudiantes universitarios que se obtuvo aplicando la fórmula para el cálculo muestral de poblaciones conocidas, mediante un muestreo no probabilístico. Se utilizó el test goniométrico para medir el rango articular, el test postural para identificar las alteraciones posturales, la técnica de palpación para identificar dolor inespecífico, prueba de resistencia para los músculos flexores (NFMET) y extensores (NEET), por último, se realizó la prueba de Spurling para identificar casos de radiculopatías. Resultados. Aunque las relaciones estadísticas no fueron consistentes, se observó que quienes utilizaron más tiempo los teléfonos celulares (87,0%) mostraron más limitaciones cervicales que los usuarios menos frecuentes (73,5%). La movilidad articular fue limitada en el 84,3% de la población, especialmente en varones (93,5%); la resistencia muscular normal en extensión fue más prevalente en el caso de los hombres (84,9%), mientras que la resistencia alterada en flexión fue más prevalente en mujeres (94,9%). Conclusiones. Según los resultados obtenidos en esta investigación, no se encontró suficiente evidencia para determinar una relación estadísticamente significativa (P˃0,05) entre las alteraciones cervicales y el uso de teléfonos celulares, aunque se observó una mayor limitación en el caso de quienes más tiempo utilizaban el dispositivo móvil.

Cervical disorders are a multifactorial problem affecting modern society. Vicious postures, trauma and congenital defects related to the cervical spine can develop instability, radicular impingement, cervicoarthrosis and cervicalgia. Objective. To relate the use of mobile devices with cervical disorders in university students. Materials and methods. Descriptive, observational study carried out between May and July 2023, with a sample of 172 university students obtained by applying the formula for the sample calculation of known populations, by means of non-probabilistic sampling. The goniometric test was used to measure joint range, the postural test to identify postural alterations, the palpation technique to identify non-specific pain, resistance test for flexor (NFMET) and extensor (NEET) muscles, and finally, the Spurling test was performed to identify cases of radiculopathy. Results. Although the statistical relationships were not consistent, it was observed that those who used cell phones longer (87.0%) showed more cervical limitations than less frequent users (73.5%). Joint mobility was limited in 84.3% of the population, especially in men (93.5%); normal muscular endurance in extension was more prevalent in men (84.9%), while impaired endurance in flexion was more prevalent in women (94.9%). Conclusions. According to the results obtained in this investigation, there was not enough evidence to determine a statistically significant relationship (P˃0.05) between cervical alterations and cell phone use, although a greater limitation was observed in the case of those who used the mobile device the longest.

Os distúrbios cervicais são um problema multifatorial que afeta a sociedade moderna. Posturas viciosas, traumas e defeitos congênitos relacionados à coluna cervical podem levar a instabilidade, impacto radicular, cervicoartrose e cervicalgia. Objetivo. Relacionar o uso de dispositivos móveis com distúrbios cervicais em estudantes universitários. Materiais e métodos. Estudo descritivo, observacional, realizado entre maio e julho de 2023, com uma amostra de 172 estudantes universitários obtida pela aplicação da fórmula para o cálculo de amostras de populações conhecidas, por meio de amostragem não probabilística. Foram utilizados o teste goniométrico para medir a amplitude articular, o teste postural para identificar alterações posturais, a técnica de palpação para identificar dores inespecíficas, o teste de resistência para músculos flexores (NFMET) e extensores (NEET) e o teste de Spurling para identificar casos de radiculopatia. Resultados. Embora as relações estatísticas não tenham sido consistentes, observou-se que aqueles que usavam telefones celulares por mais tempo (87,0%) apresentavam mais limitações cervicais do que os usuários menos frequentes (73,5%). A mobilidade articular foi limitada em 84,3% da população, especialmente no sexo masculino (93,5%); a resistência muscular normal em extensão foi mais prevalente no sexo masculino (84,9%), enquanto a resistência prejudicada em flexão foi mais prevalente no sexo feminino (94,9%). Conclusões. De acordo com os resultados obtidos nesta pesquisa, não houve evidências suficientes para determinar uma relação estatisticamente significativa (P˃0,05) entre os distúrbios cervicais e o uso de telefones celulares, embora tenha sido observada uma limitação maior no caso daqueles que usaram o dispositivo móvel por períodos mais longos.

Autosomal dominant distal renal tubular acidosis in two pediatric patients with mutations in the SLC4A1 gene. Can the maximum urinary pCO2 test be normal?

Primary distal renal tubular acidosis (dRTA) is a rare tubulopathy characterised by the presence of hyperchloremic metabolic acidosis. It is caused by the existence of a defect in the function of the H+ -ATPase located on the luminal side of the α-intercalated cells or the Cl - HCO3- (AE1) anion exchanger located on the basolateral side. Patients do not acidify the urine after acid overload (NH4Cl) or after stimulating H+ secretion by obtaining a high intratubular concentration of an anion such as chlorine (pH is measured) or HCO3- (urinary pCO2 is measured). We present a family with autosomal dominant dRTA produced by a heterozygous mutation in the SLC4A1 gene in which the two paediatric members showed a test of normal maximum urinary pCO2. Our hypothesis is that since the H + -ATPase is intact, at least initially, the stimulation induced by intratubular electronegativity to secrete H + could be effective, which would allow the maximum urinary pCO2 to be paradoxically normal, which could explain the onset, moderate presentation of symptoms and late diagnosis in patients with this mutation. This is the first documented case of a dominant dRTA in Mexico.

Acidosis tubular renal distal autosómica dominante en dos pacientes pediátricos con mutaciones en el gen SLC4A1. ¿La prueba de la pCO2 urinaria máxima puede ser normal? / Autosomal dominant distal renal tubular acidosis in two pediatric patients with mutations in the SLC4A1 gene. Can the maximum urinary pCO2 test be normal?

La acidosis tubular renal distal (ATRd) primaria es una tubulopatía poco frecuente caracterizada por la presencia de acidosis metabólica hiperclorémica. Está generada por la existencia de un defecto en la función de la H+-ATPasa situada en el lado luminal de las células α-intercaladas o del intercambiador de aniones Cl−-HCO3− (AE1) ubicado en el lado basolateral. Los pacientes no acidifican la orina tras una sobrecarga ácida (NH4Cl) o tras estimular la secreción de H+ mediante la obtención de una elevada concentración intratubular de un anión como cloro (se mide el pH) o HCO3− (se mide la pCO2 urinaria). Se presenta una familia con ATRd autosómica dominante producida por una mutación heterocigota en el gen SLC4A1 en la que los 2 miembros en edad pediátrica mostraron una prueba de la pCO2 urinaria máxima normal. Nuestra hipótesis es que al estar intacta, al menos inicialmente, la H+-ATPasa, podría ser efectivo el estímulo inducido por la electronegatividad intratubular para secretar H+ lo que permitiría que la pCO2 urinaria máxima fuera paradójicamente normal, lo que pudiera explicar el inicio tardío, la presentación moderada de los síntomas y el diagnóstico en edades más avanzadas, en los pacientes con dicha mutación. Este es el primer caso documentado de una ATRd dominante en México. (AU)

Primary distal renal tubular acidosis (dRTA) is a rare tubulopathy characterized by the presence of hyperchloremic metabolic acidosis. It is caused by the existence of a defect in the function of the H+-ATPase located on the luminal side of the α-intercalated cells or the Cl− HCO3− (AE1) anion exchanger located on the basolateral side. Patients do not acidify the urine after acid overload (NH4Cl) or after stimulating H+ secretion by obtaining a high intratubular concentration of an anion such as chlorine (pH is measured) or HCO3− (urinary pCO2 is measured). We present a family with autosomal dominant dRTA produced by a heterozygous mutation in the SLC4A1 gene in which the two pediatric members showed a test of normal maximum urinary pCO2. Our hypothesis is that since the H+-ATPase is intact, at least initially, the stimulation induced by intratubular electronegativity to secrete H+ could be effective, which would allow the maximum urinary pCO2 to be paradoxically normal, which could explain the onset, moderate presentation of symptoms and late diagnosis in patients with this mutation. This is the first documented case of a dominant dRTA in Mexico. (AU)

Pathogenic Variants of SLC22A12 (URAT1) and SLC2A9 (GLUT9) in Spanish Patients with Renal Hypouricemia: Founder Effect of SLC2A9 Variant c.374C>T; p.(T125M).

Renal hypouricemia (RHUC) is a rare inherited disorder characterized by impaired urate reabsorption in the proximal tubule resulting in low urate serum levels and increased urate excretion. Some patients may present severe complications such as exercise-induced acute renal failure and nephrolithiasis. RHUC is caused by inactivating mutations in the SLC22A12 (RHUC type 1) or SLC2A9 (RHUC type 2) genes, which encode urate transporters URAT1 and GLUT9, respectively. In this study, our goal was to identify mutations associated with twenty-one new cases with RHUC through direct sequencing of SLC22A12 and SLC2A9 coding exons. Additionally, we carried out an SNPs-haplotype analysis to determine whether the rare SLC2A9 variant c.374C>T; p.(T125M), which is recurrent in Spanish families with RHUC type 2, had a common-linked haplotype. Six intragenic informative SNPs were analyzed using PCR amplification from genomic DNA and direct sequencing. Our results showed that ten patients carried the SLC22A12 mutation c.1400C>T; p.(T467M), ten presented the SLC2A9 mutation c.374C>T, and one carried a new SLC2A9 heterozygous mutation, c.593G>A; p.(R198H). Patients carrying the SLC2A9 mutation c.374C>T share a common-linked haplotype, confirming that it emerged due to a founder effect.

Effectiveness of diaphragmatic ultrasound as a predictor of successful weaning from mechanical ventilation: a systematic review and meta-analysis.

BACKGROUND: Several measurements have been used to predict the success of weaning from mechanical ventilation; however, their efficacy varies in different studies. In recent years, diaphragmatic ultrasound has been used for this purpose. We conducted a systematic review and meta-analysis to evaluate the effectiveness of diaphragmatic ultrasound in predicting the success of weaning from mechanical ventilation. METHODS: Two investigators independently searched PUBMED, TRIP, EMBASE, COCHRANE, SCIENCE DIRECT, and LILACS for articles published between January 2016 and July 2022. The methodological quality of the studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool; additionally, the certainty of the evidence is evaluated using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) methodology. Sensitivity and specificity analysis was performed for diaphragmatic excursion and diaphragmatic thickening fraction; positive and negative likelihood ratios and diagnostic odds ratios (DOR) with their confidence intervals (95% CI) were calculated by random effects analysis, summary receiver operating characteristic curve was estimated. Sources of heterogeneity were explored by subgroup analysis and bivariate meta-regression. RESULTS: Twenty-six studies were included, of which 19 were included in the meta-analysis (1204 patients). For diaphragmatic excursion, sensitivity was 0.80 (95% CI 0.77-0.83), specificity 0.80 (95% CI 0.75-0.84), area under the summary receiver operating characteristic curve 0.87 and DOR 17.1 (95% CI 10.2-28.6). For the thickening fraction, sensitivity was 0.85 (95% CI 0.82-0.87), specificity 0.75 (95% CI 0.69-0.80), area under the summary receiver operating characteristic curve 0.87 and DOR 17.2 (95% CI 9.16-32.3). There was heterogeneity among the included studies. When performing a subgroup analysis and excluding studies with atypical cutoff values, sensitivity and specificity increased for diaphragmatic thickening fraction; sensitivity increased and specificity decreased for diaphragmatic excursion; when comparing studies using pressure support (PS) versus T-tube, there was no significant difference in sensitivity and specificity; bivariate meta-regression analysis shows that patient position at the time of testing was a factor of heterogeneity in the included studies. CONCLUSIONS: Measurement of diaphragmatic excursion and diaphragmatic thickening fraction predict the probability of successful weaning from mechanical ventilation with satisfactory diagnostic accuracy; however, significant heterogeneity was evident in the different included studies. Studies of high methodological quality in specific subgroups of patients in intensive care units are needed to evaluate the role of diaphragmatic ultrasound as a predictor of weaning from mechanical ventilation.

Reflections on TRP and TP/GFR in the definition of renal phosphate loss: conceptual review.

BACKGROUND: Fractional tubular reabsorption of phosphate (TRP) has been used for over 60 years to establish the existence of renal phosphate loss. It is a parameter of corrected volume per decilitre of glomerular filtration rate (GFR). Later, a mass parameter per dl GFR called TP/GFR (tubular PO4 reabsorption per dl GFR) was devised which some authors have sought to substitute for TRP. The aim of the present work is to attempt to demonstrate that TRP and TP/GFR are similar parameters and, in certain aspects, TRP is more effective for diagnosis. METHODS: Data were gathered on the metabolism of phosphate corresponding to a group of healthy children without hypophosphatemia (n = 47), a group of patients with idiopathic hypercalciuria (n = 27), and ten patients diagnosed with X-linked hypophosphatemia (XLH). The TRP, the TP/GFR, and the percent tubular reabsorption of phosphate were calculated. RESULTS: All the patients with XLH presented TRP values lower than 95 ml/dl GFR and of TP/GFR equal to or lower than 2.8 mg/dl GFR. In the total sample, a direct correlation was observed between TRP and TP/GFR (r = 0.65; p = 0.01). The TRP and the percent tubular reabsorption of phosphate values were the same in the three groups (r = 1; p = 0.01). CONCLUSIONS: TRP and TP/GFR are similar parameters. TRP is more effective than TP/GFR given that in renal hypophosphatemia it is always below 95% and above 95% in reduced phosphatemia and normal kidney proximal tubular function. There is no solid reason for using TP/GFR rather than TRP. A higher resolution version of the Graphical abstract is available as Supplementary information.