Only recently, d-amino acids have been identified in mammals. Of these, d-serine has been most extensively studied. d-Serine was found to play an important role as a neurotransmitter in the human central nervous system (CNS) by binding to the N-methyl-d-aspartate receptor (NMDAr), similar to glycine. Therefore, d-serine may well play a role in all physiological and pathological processes in which

Aim: To determine the incidence of late intracranial vitamin K deficiency bleeding (VKDB) in The Netherlands using the Dutch Pediatric Intensive Care Evaluation (PICE) registry. Methods: The PICE registry was used to identify all infants who were admitted to a Dutch pediatric intensive care unit (PICU) with intracranial bleeding between 1 January 2004 and 31 December 2007. Cases of confirmed late

3-Phosphoglycerate dehydrogenase (3-PGDH) deficiency is considered to be a rare cause of congenital microcephaly, infantile onset of intractable seizures and severe psychomotor retardation. Here, we report for the first time a very mild form of genetically confirmed 3-PGDH deficiency in two siblings with juvenile onset of absence seizures and mild developmental delay. Amino acid analysis showed se

BACKGROUND: Hypoglycemia is one of the most common metabolic derangements in childhood. To establish the cause of hypoglycemia, fasting tolerance tests can be used. Currently available reference values for fasting tolerance tests have limitations in their use in daily practice. OBJECTIVE: The aim of this study was to determine the reference values of metabolites involved in glucose homeostasis dur

Background Phenylketonuria (PKU) causes irreversible central nervous system damage unless a phenylalanine (PHE) restricted diet with amino acid supplementation is maintained. To prevent growth retardation, a protein/amino acid intake beyond the recommended dietary protein allowance is mandatory. However, data regarding disease and/or diet related changes in body composition are inconclusive and re

Two young girls without a notable medical history except for asthma presented with an acute toxic encephalopathy with very low serine concentrations both in plasma and cerebrospinal fluid (CSF) comparable to patients with 3-phosphoglycerate dehydrogenase (3-PGDH) deficiency. Clinical symptoms and enzyme measurement (in one patient) excluded 3-PGDH deficiency. Deficiencies in other serine biosynthe

OBJECTIVES:: Vitamin K deficiency (VKD) may cause life-threatening haemorrhages, especially in breast-fed infants with unrecognised cholestasis. Interestingly, hypoallergenic formulas appear overrepresented in reported cases of VKD bleeding (VKDB) in formula-fed infants. We therefore assessed whether the risk of VKD in formula-fed infants with cholestasis is associated with hypoallergenic formulas

Hypomyelination is observed in the context of a growing number of genetic disorders that share clinical characteristics. The aim of this study was to determine the possible role of magnetic resonance imaging pattern recognition in distinguishing different hypomyelinating disorders, which would facilitate the diagnostic process. Only patients with hypomyelination of known cause were included in thi

The disorders of serine biosynthesis are a group of inborn errors of metabolism characterised by congenital microcephaly, seizures and severe psychomotor retardation. Although these disorders are rare the prompt recognition of serine deficiency is important as these disorders are treatable. The diagnosis is based on decreased concentrations of serine in cerebrospinal fluid (CSF). It has previously

In this clinical case, the importance of early detection of Hurler syndrome for outcomes of stem cell transplantation in this patient population is illustrated. Nowadays, children with Hurler syndrome can be treated with stem cell transplantation, but the results largely depend on the moment of treatment. If the procedure is initiated in an early stage of disease, better results can be obtained. T

Deficiency of subunit 6 of the conserved oligomeric Golgi (COG6) complex causes a new combined N-and O-glycosylation deficiency of the congenital disorders of glycosylation, designated as CDG-IIL (COG6-CDG). The index patient presented with a severe neurologic disease characterized by vitamin K deficiency, vomiting, intractable focal seizures, intracranial bleedings and fatal outcome in early infa

Hurler syndrome (HS), the most severe phenotype in the spectrum of mucopolysaccharidosis type I, is caused by a deficiency of the lysosomal enzyme alpha-L-iduronidase (IDUA). At present, hematopoietic stem cell transplantation (HSCT) is the only treatment able to prevent disease progression in the central nervous system, and therefore considered the treatment of choice in HS patients. Because IDUA

Background: Analysis of sialic acid (SA) metabolites in cerebrospinal fluid (CSF) is important for clinical diagnosis. In the present study, a high-performance liquid chromatography-tandem mass spectrometry (HPLC/MS/MS) method for free sialic acid (FSA) and total sialic acid (TSA) in human CSF was validated. Methods: The method utilized a simple sample-preparation procedure of protein precipitatio

As continuous access to energy is necessary for survival, the level of energy stores has a strong effect on fitness and survival. Behaviors by which energy stores are acquired and built up are known as foraging, and this is a very common topic in animal behavior studies. It is especially important for flying organisms to finely tune the level of energy reserves they carry. While most animals will

Many animals store food outside of their own bodies for later consumption, not only birds and mammals, but also invertebrates such as honeybees. I refer to such food storage as hoarding, to distinguish it from internal storage such as in fat deposits. There are two distinct food-hoarding strategies: larder hoarding (all food is stored in one or a few central larders) and scatter hoarding (storage

In the present paper, the effectiveness of a vibration isolation mat for a railway slab track system is studied using a finite element model of the railway track. The finite elements are formulated in a moving frame of reference following the moving load at a particular speed. The rails are modeled using Bernoulli beams, whereas the track slab and an underlying supporting plate are modeled using K

The traditional way to capture rate and amplitude dependence of filled rubbers is by a branched model containing elastic, viscous, and frictional branches, leading to a decoupling of the rate and amplitude dependence. In order to capture the experimentally observed phenomena with a steeper increasing dynamic modulus with frequency, for small amplitudes, a model by Besseling (1958) is revisited. In

The extraordinary adaptability of invertebrates is in no small part due to their sense organs, and particularly their eyes, which help them to find food, locate mates, escape predators and migrate to new habitats. Even though most invertebrates do not see as sharply as we do, many see much better in dim light, can experience many more colours, can see polarised light and can clearly distinguish ex