Publications by authors named "Alvaro Martin Rivada"

Ornithine transcarbamylase deficiency (OTCD) is the most common disorder of the urea cycle and is caused by a mutation of the gene, located on chromosome X. Its prevalence is estimated at 1 in 80,000 to 56,500 births, but this X-chromosomal inheritance results in males being more affected than females. In neonates affected with this disorder, hyperammonemia after birth can lead to neurological and liver damage that can be fatal.

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Introduction: Eating disorders (EDs) develop more frequently in young females. Following the COVID-19 pandemic, there has been evidence of an increase in children and adolescents, with an earlier onset and a worse body weight and nutritional status. The aim of this study was to determine whether this trend has also been observed in our region over the past 6 years.

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Context: Anomalies in the growth hormone (GH)/insulin-like growth factor (IGF) axis, are common in children with type 1 diabetes mellitus (T1DM), even in those reaching a normal or near-normal final height. However, concentrations of the IGF bioavailability regulatory factors (pappalysins [PAPP-As] and stanniocalcins [STCs]) have not been reported in children with T1DM.

Objective: To determine serum concentrations of PAPP-As and STCs in children at diagnosis of T1DM and after insulin treatment and the correlation of these factors with other members of the GH/IGF axis, beta-cell insulin reserve, auxology, and nutritional status.

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Background: Prepubertal children with obesity frequently have enhanced growth, accelerated skeletal maturation and changes in the GH-IGF axis. However, the involvement of pappalysins (PAPP-A, PAPP-A2) and stanniocalcins (STC1, STC2) as regulators of IGF bioavailability has not been studied in obesity.

Objective: We aimed to determine the effects of childhood obesity and weight reduction on serum levels of PAPP-A, PAPP-A2, STC1 and STC2 and their relationship with IGF bioavailability, growth, and other components of the GH-IGF system.

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Context: Prader-Willi syndrome (PWS) is associated with impaired growth hormone (GH) secretion and decreased insulin-like growth factor (IGF)-I levels. Pappalysins (PAPP-A, PAPP-A2) and stanniocalcins (STC-1, STC-2) regulate IGF binding-protein (IGFBP) cleavage and IGF bioavailability, but their implication in PWS is unknown.

Objective: We determined serum levels of PAPP-As and STCs in association with IGF axis components in prepubertal and pubertal patients with PWS, also analyzing the effect of GH treatment.

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Context: Anorexia nervosa (AN) can cause severe undernutrition associated with alterations in the IGF axis. Pappalysins (PAPP-A, PAPP-A2) and stanniocalcins (STC-1, STC-2) modulate IGF binding-protein (IGFBP) cleavage and IGF bioavailability, but their implications in AN are unknown.

Objective: We determined serum levels of PAPP-As and STCs in relationship with classical IGF axis parameters in female adolescents with AN and their association with nutritional status and secondary amenorrhea.

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Introduction: Nutritional status assessment in anorexia nervosa (AN) includes the evaluation and monitoring of body composition throughout the treatment period. The gold standard for the study of body composition is dual-energy X-ray absorptiometry (DEXA), although electrical bioimpedance (BIA) is a more accessible, cheaper and faster method that does not involve exposure to radiation.

Material And Methods: We recruited 33 female adolescents with AN (age, 11.

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Context: Successful rates of hematopoietic stem cell transplantation (HSCT) face paralleled escalation of late endocrine and metabolic effects.

Objective: This work aimed to characterize these sequelae distinguishing between the underlying pathologies and treatments received.

Methods: A retrospective descriptive study was conducted in 157 children post-HSCT (hematopoietic pathology [N = 106], solid tumors [N = 40], and rare entities [N = 11]) followed at a single endocrine department between 2009 and 2019.

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Introduction: Development of cystic fibrosis-related diabetes (CFRD) is associated with worsening of nutritional status and lung function, as well as increased mortality. The relevance of diagnosing the «pre-diabetic» status in these patients has not been addressed and the utility of HbA1c measurement in these patients is under discussion.

Aim: To study and characterise the different categories of carbohydrate metabolism impairment in paediatric patients with cystic fibrosis.

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Objectives: We present the results of our experience in the diagnosis and follow up of the positive cases for propionic, methylmalonic acidemias and cobalamin deficiencies (PA/MMA/MMAHC) since the Expanded Newborn Screening was implemented in Madrid Region.

Methods: Dried blood samples were collected 48 h after birth. Amino acids and acylcarnitines were quantitated by MS/MS.

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Context: Pappalysins (PAPP-A, PAPP-A2) modulate body growth by increasing insulin-like growth factor I (IGF-I) bioavailability through cleavage of insulin-like growth factor binding proteins (IGFBPs) and are inhibited by stanniocalcins (STC1, STC2). Normative data on these novel factors, as well as on free IGF-I and uncleaved fractions of IGFBPs, are not well established.

Objective: This work aimed to determine serum concentrations of PAPP-A, PAPP-A2, STC1, and STC2 in relationship with other growth hormone (GH)-IGF axis parameters during development.

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Leptin is involved in the modulation of insulin signaling in peripheral tissues, being closely associated with changes in lipid metabolism. This adipokine modifies inflammatory pathways that can interact with insulin targets in peripheral organs; however, the mechanisms remain unclear. Inflammatory and insulin signaling targets, cytokines, adiponectin, irisin and non-esterified fatty acid (NEFA) levels and enzymes of fatty acid anabolism were studied in the gastrocnemius of chronic centrally infused leptin (L), pair-fed and control rats.

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Article Synopsis
  • The study analyzes the outcomes of diagnosing inborn errors of metabolism (IEM) in newborns following the implementation of Expanded Newborn Screening from 2011 to 2019, where over 592,000 children were screened.
  • Among those screened, 902 had abnormal results, and 222 confirmed cases of IEM were identified, including various conditions like aminoacidopathies, fatty acid oxidation (FAO) defects, and organic acidurias.
  • Only 8.5% of the affected infants showed symptoms at the time of the newborn screening, and genetic testing confirmed the diagnosis in all except two cases of hyperphenylalaninemia (HPA).
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Article Synopsis
  • The GH/IGF axis is crucial for development and aging, involving various proteins and receptors that are tightly regulated, although this regulation isn't fully understood.
  • Recent findings have identified mutations in the gene for the PAPP-A2 protease, which plays a key role in releasing IGFs from binding proteins to enable their action on IGF receptor 1.
  • This review discusses the effects of PAPP-A2 on growth physiology, drawing insights from studies on genetically modified animals and patients lacking PAPP-A2.
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Limited therapeutic tools and an overwhelming clinical demand are the major limiting factors in pediatric obesity management. The optimal protocol, environment, body mass index (BMI) change targets and duration of obesity-oriented interventions remain to be elucidated. We aimed to characterize the singularities of follow-up, anthropometric and metabolic evolution of a large cohort of pediatric patients with obesity in a specialized university hospital outpatient obesity unit.

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Leptin modulates insulin signaling and this involves the Akt pathway, which is influenced by changes in the inflammatory environment and with leptin regulating cytokine synthesis. We evaluated the association between activation of the insulin-signaling pathway and alterations in pro- and anti-inflammatory cytokine levels in inguinal fat and liver of chronic central leptin infused (L), pair-fed (PF), and control rats. Signal transducer and activator of transcription 3 (STAT3) phosphorylation was increased in inguinal fat and reduced in liver of L rats.

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PAPP-A2 deficiency is a novel syndrome characterized by short stature due to low IGF bioactivity, skeletal abnormalities and decreased bone mineral density (BMD). Treatment with recombinant human IGF-1 (rhIGF-1) for 1 year demonstrated to increase growth velocity and BMD, without reported adverse effects, but data regarding the long-term efficacy and safety of rhIGF-1 administration in this entity has not yet been reported. Two Spanish siblings with short stature due to a homozygous loss-of-function mutation in the PAPP-A2 gene (p.

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In 2016 a new syndrome with postnatal short stature and low IGF1 bioavailability caused by biallelic loss-of-function mutations in the gene encoding the metalloproteinase pregnancy-associated plasma protein A2 (PAPP-A2) was described in two families. Here we report two siblings of a third family from Saudi Arabia with postnatal growth retardation and decreased IGF1 availability due to a new homozygous nonsense mutation (p.Glu886* in exon 7) in PAPPA2.

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Introduction: Primary autosomal recessive microcephalies (MCPHs) are characterized by primary dwarfism with MCPH and may present delayed psychomotor development and visual impairment. Biallelic loss of function variants in the PLK4 gene, which encodes the polo-like kinase 4 protein involved in centriole biogenesis, has been recently identified in several patients with MCPH and various ethnic backgrounds.

Case Presentation: Here, we describe 2 siblings of different sex from Equatorial Guinea harboring a homozygous frameshift mutation in PLK4 (c.

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Article Synopsis
  • Tandem mass spectrometry (MS/MS) has been used since 2011 in the Community of Madrid for newborn screening, detecting metabolic disorders from dried blood samples, covering 13 conditions related to amino acids and fatty acids.
  • Over 592,000 newborns were screened between 2011 and 2019, resulting in 901 positive cases, with 230 diagnosed with 30 different inborn errors of metabolism, leading to an overall positive predictive value of 25.6%.
  • The screening program was successful in identifying 93% of cases in the presymptomatic stage, demonstrating its effectiveness as a public health initiative.
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Purpose: Rasmussen's encephalitis (RE) is a chronic neurological disorder characterized by inflammation of the cerebral cortex, mainly unilateral, that leads to drug-resistant epilepsy and progressive neurological impairment. Central Precocious Puberty (CPP) is uncommon, albeit increased in frequency in patients with neurological conditions and the physiopathological bases of these associations remains unclear in most cases. Epilepsy has been proposed to play a role, as well as the accumulation of substances produced as a result of metabolism or tissue degeneration in some neurodegenerative diseases.

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Article Synopsis
  • Hyperammonemic encephalopathy is a serious side effect of the antiepileptic drug sodium valproate (VPA) observed in a study of 25 pediatric patients, primarily females aged around 7.6 years.
  • The patients were treated with carglumic acid (CA), which effectively reduced elevated ammonia levels and resolved related symptoms over an average treatment duration of about 2.17 days.
  • Despite the initial success of CA treatment, 68% of patients discontinued VPA, and 62% of those who continued VPA experienced recurrent hyperammonemia episodes.
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Background Aldosterone deficiency (hypoaldosteronism) or aldosterone resistance (pseudohypoaldosteronism) both result in defective aldosterone activity. Case presentation A 42-day-old man presented with failure to thrive, hyponatremia, high urine sodium output, severe hyperkalemia and high plasma renin activity and aldosterone levels. NR3C2, SCNN1A, B and G sequencing showed no variants.

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Background: Central precocious puberty (CPP) has been associated with loss-of-function mutations in 2 paternally expressed genes (MKRN3 and DLK1). Rare defects in the DLk1 were also associated with poor metabolic phenotype at adulthood.

Objective: Our aim was to investigate genetic and biochemical aspects of DLK1 in a Spanish cohort of children with CPP without MKRN3 mutations.

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