Monogenic disorders as mimics of juvenile idiopathic arthritis.

Background: Juvenile idiopathic arthritis is the most common chronic rheumatic disease of childhood. The term JIA encompasses a heterogenous group of diseases. The variability in phenotype of patients affected by the disease means it is not uncommon for mimics of JIA to be misdiagnosed.

A review of O labelling Studies to probe the mechanism of aromatase (CYP191A).

Our previous studies, using precursors for two classes of estrogens, estrone and estriol, have highlighted the following facets of aromatase. The overall reaction, converting androgens into estrogens, occurs in three steps, each requiring NADPH and O. In Step 1, a 19-hydroxy intermediate is produced, which in Step 2, is converted into a 19-oxo derivative via a gem -diol intermediate with the stereospecific loss of H.

A Neuroimaging Preparation Protocol Tailored for Autism.

This paper describes the key basic elements required for a successful multi-parametric MRI data acquisition in awake children with autism. The procedure was designed by taking into account methodological challenges arising from the acquisition of Resting State fMRI (RS fMRI) data, and factors such as cost, time, and staff availability. The ultimate aim was to prepare an imaging preparation protocol with high transferability to the whole autism spectrum, adaptable for use in a multi-site research with multiple time points.

Thyroid scintigraphy differentiates subtypes of congenital hypothyroidism.

Introduction: UK screening for congenital hypothyroidism (CH) is based on dried blood spot Thyroid Stimulating Hormone (TSH). Scintigraphy may identify CH subtypes classified as dysplasia, gland in situ (GIS) and ectopia, but is not performed in all centres. We retrospectively investigated the role of scintigraphy to identify CH subtypes in a single tertiary centre cohort.

Patterns and frequency of renal abnormalities in Fanconi anaemia: implications for long-term management.

Background: Fanconi anaemia (FA) is an inherited disease with bone marrow failure, variable congenital and developmental abnormalities, and cancer predisposition. With improved survival, non-haematological manifestations of FA become increasingly important for long-term management. While renal abnormalities are recognized, detailed data on patterns and frequency and implications for long-term management are sparse.

A heterozygous microdeletion of 20p12.2-3 encompassing PROKR2 and BMP2 in a patient with congenital hypopituitarism and growth hormone deficiency.

Congenital growth hormone deficiency is a rare disorder with an incidence of approximately 1 in 4,000 live births. Pituitary development is under the control of a multitude of spatiotemporally regulated signaling molecules and transcription factors. Mutations in the genes encoding these molecules can result in hypopituitarism but for the majority of children with congenital hypopituitarism, the aetiology of their disease remains unknown.

Quantification of structural changes in the corpus callosumin children with profound hypoxic-ischaemic brain injury.

Background: Birth-related acute profound hypoxic-ischaemic brain injury has specific patterns of damage including the paracentral lobules.

Objective: To test the hypothesis that there is anatomically coherent regional volume loss of the corpus callosum as a result of this hemispheric abnormality.

Materials And Methods: Study subjects included 13 children with proven acute profound hypoxic-ischaemic brain injury and 13 children with developmental delay but no brain abnormalities.

Central nervous system abnormalities in Fanconi anaemia: patterns and frequency on magnetic resonance imaging.

Objective: Fanconi anaemia (FA) is an inherited disease associated with congenital and developmental abnormalities resulting from the disruption of a multigenic DNA damage response pathway. This study aimed to define the MRI appearances of the brain in patients with FA in correlation with their genetic and clinical features.

Methods: A review of the brain MRI in 20 patients with FA was performed.

Multiple synchronous sites of origin of vestibular schwannomas in neurofibromatosis Type 2.

Background: Neurofibromatosis Type 2 (NF2) is a dominantly inherited tumour syndrome with a phenotype which includes bilateral vestibular (eighth cranial nerve) schwannomas. Conventional thinking suggests that these tumours originate at a single point along the superior division of the eighth nerve.

Methods: High resolution MRI was performed in children genetically proven to have NF2.

Acyl-Carbon Bond Cleaving Cytochrome P450 Enzymes: CYP17A1, CYP19A1 and CYP51A1.

Cytochrome P450 (P450 or CYP) enzymes in their resting state contain the heme-iron in a high-spin FeIII state. Binding of a substrate to a P450 enzyme allows transfer of the first electron, producing a Fe(II) species that reacts with oxygen to generate a low-spin iron superoxide intermediate (FeIII-O-O•) ready to accept the second electron to produce an iron peroxy anion intermediate (a, FeIII-O-O-). In classical monooxygenation reactions, the peroxy anion upon protonation fragments to form the reactive Compound I intermediate (Por•+FeIV=O), or its ferryl radical resonance form (FeIV-O•).

Insulinoma in childhood: clinical, radiological, molecular and histological aspects of nine patients.

Background: Insulinomas are a rare cause of hyperinsulinaemic hypoglycaemia (HH) in children. The clinical features, investigations, management and histology of these rare pancreatic tumours in children have not been described in a large cohort of patients.

Methods: We conducted a retrospective review of cases diagnosed between 2000 and 2012, presenting to two referral centres in the United Kingdom.

A review of mechanistic studies on aromatase (CYP19) and 17α-hydroxylase-17,20-lyase (CYP17).

In the conventional P-450 dependent hydroxylation reaction, the Fe(III) resting state of the enzyme, by a single electron transfer, is reduced to Fe(II), which reacts with O(2) to produce a Fe(III)-O-O intermediate. The latter following the transfer of another electron furnishes a ferric-peroxyanion, Fe(III)-O-O(-), which after protonation leads to the fission of the O-O bond resulting in the formation of Fe(V)O, the key player in the hydroxylation process. Certain members of the P-450 family, including CYP17 and CYP19, catalyze, at the same active site, not only the hydroxylation process but also an acyl-carbon bond cleavage reaction which has been interpreted to involve the nucleophilic attack of the ferric-peroxyanion, Fe(III)-O-O(-), on the acyl carbon to furnish a tetrahedral intermediate which fragments, leading to acyl-carbon cleavage.

Inventory of 'slow exchanging' hydrogen atoms in human proinsulin and its derivatives: observations on the mass spectrometric analysis of deuterio-proteins in D(2)O.

Secondary structure elements of human proinsulin and of its tryptic products were compared by H/D exchange, in a single-pot, using mass spectrometry. Human proinsulin containing an N-terminal methionine, M-proinsulin, was engineered and converted into a perdeuterio derivative, which using an optimized mass spectrometric protocol and manual calculations gave a mass of 9669.6 (+/-1) Da showing the replacement, with deuterium of 146.

Fluorescence quenching methods to study lipid-protein interactions.

This unit describes how fluorescence quenching methods can be used to determine binding constants for phospholipids binding to intrinsic membrane proteins. Reconstitution of a Trp-containing intrinsic membrane protein with bromine-containing phospholipids leads to quenching of the Trp fluorescence of the protein; the extent of quenching depends on the strength of binding of the phospholipid to the protein. Protocols are included for the synthesis of bromine-containing phospholipids from phospholipids containing carbon-carbon double bonds in their fatty acyl chains and for the reconstitution of membrane proteins into bilayers containing bromine-containing phospholipids.

Successful renal transplantation in children in the presence of thrombosis of the inferior vena cava.

Thrombosis of the inferior vena cava (IVC) has previously been considered to be a contraindication to renal transplantation in children because of the technical difficulties associated with surgery and the increased risk of graft thrombosis. We report three children with previous IVC thrombosis who underwent renal transplantation at our institution over the last 5 years. The pretransplant imaging of these patients included direct venography or magnetic resonance venography to evaluate venous outflow.

Maternal low protein diet restricted to the preimplantation period induces a gender-specific change on hepatic gene expression in rat fetuses.

It has been shown previously that maternal low protein diet (LPD) throughout rat gestation altered hepatic gene expression and enzyme activities in offspring. Here, we investigate the effect of maternal LPD (9% casein vs. 18% control) exclusively during the preimplantation period (switched diet group) or provided throughout gestation on hepatic gene expression in day 20 fetuses.

Identification of the hydrophobic thickness of a membrane protein using fluorescence spectroscopy: studies with the mechanosensitive channel MscL.

The hydrophobic thickness of a membrane protein is an important parameter, defining how the protein sits within the hydrocarbon core of the lipid bilayer that surrounds it in a membrane. Here we show that Trp scanning mutagenesis combined with fluorescence spectroscopy can be used to define the hydrophobic thickness of a membrane protein. The mechanosensitive channel of large conductance (MscL) contains two transmembrane alpha-helices, of which the second (TM2) is lipid-exposed.

The cationic charges on Arg347, Arg358 and Arg449 of human cytochrome P450c17 (CYP17) are essential for the enzyme's cytochrome b5-dependent acyl-carbon cleavage activities.

CYP17 (17alpha-hydroxylase-17,20-lyase; also P450c17 or P450(17alpha)) catalyses the17alpha-hydroxylation of progestogens and the subsequent acyl-carbon cleavage of the 17alpha-hydroxylated products (lyase activity) in the biosynthesis of androgens. The enzyme also catalyses another type of acyl-carbon cleavage (direct cleavage activity) in which the 17alpha-hydroxylation reaction is by-passed. Human CYP17 is heavily dependent on the presence of the membrane form of cytochrome b(5) for both its lyase and direct cleavage activities.

Optic nerve size evaluated by magnetic resonance imaging in children with optic nerve hypoplasia, multiple pituitary hormone deficiency, isolated growth hormone deficiency, and idiopathic short stature.

Objective: To objectively define criteria for intracranial optic nerve (ON) size in ON hypoplasia (ONH) on magnetic resonance imaging (MRI) scans.

Study Design: Intracranial ON sizes from MRI were compared between 46 children with ONH diagnosed by ophthalmoscopy (group 1, isolated ONH, 8 children; and group 2, ONH associated with abnormalities of the hypothalamic-pituitary axis and septum pellucidum, 38 children) and children with multiple pituitary hormone deficiency (group 3, multiple pituitary hormone deficiency, 14 children), isolated growth hormone deficiency (group 4, isolated growth hormone deficiency, 15 children), and idiopathic short stature (group 5, idiopathic short stature, 10 children). Intracranial ON size was determined by the cross-sectional area, calculated as [pi x (1/2) height x (1/2) width].

Glyceraldehyde phosphate dehydrogenase oxidation during cardiac ischemia and reperfusion.

Objectives: Protein S-glutathiolation is a predicted mechanism by which protein thiol groups are oxidized during the oxidative stress of ischaemia and reperfusion. We measured protein S-thiolation during ischaemia and reperfusion and investigated the effect of this oxidative modification on the function of GAPDH.

Methods: Glutathione was biotinylated (biotin-GSH) and used to probe for protein S-glutathiolation in isolated rat hearts using non-reducing Western blots and streptavidin-HRP.