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Introduction Autosomal recessive forms of pseudohypoaldosteronism are caused by genetic defects in the epithelial sodium channel. Little is known about the long-term outcome and medication needs during childhood and adolescence. Objective This study reports a single-centre experience of children affected with this ultra-rare condition over a 37-year period. Methods We report the clinical presentation, growth, neuro-development, associated conditions, mortality and medication dosing and administration for 12 affected children from eight families. Results All children were presented within the first 2 weeks of life with life-threatening, severe hyperkalaemia and hyponatraemia. All parents were consanguineous and of South Asian, Middle Eastern or African ethnic origin. Eight children had homozygous mutations in the SCNN1A and SCNN1G genes, encoding the epithelial sodium channel subunits alpha and gamma, respectively, including one novel mutation. Three children died (25%) and two (16%) had severe neurological impairment post-cardiac arrest secondary to hyperkalaemia. One affected female had a successful pregnancy at the age of 28 years. Conclusion Despite high mortality and morbidity in this condition, survival with normal physical and neurological outcome is possible, justifying intensive management to prevent electrolyte imbalance.

Introduction Capturing the patient experience of living with a rare disease such as X-linked hypophosphataemia (XLH) is critical for a holistic understanding of the burden of a disease. The complexity of the disease coupled with the limited population makes elicitation of the patient burden methodologically challenging. This study used qualitative information direct from patient and caregiver statements to assess the burden of XLH. Methods A thematic analysis was conducted on statements received during a National Institute for Health and Care Excellence (NICE) online public open consultation from 15 June to 6 July 2018. Researchers and clinical experts generated themes and codes based on expected aspects of XLH burden. Statements were independently coded by two reviewers, adding additional codes as required, and analysed by frequency and co-reporting across age groups. Results The majority of responses were submitted from UK-based patients with some from the USA and Australia, and the statements related to children, adolescents and adults. The findings suggest that the greatest burden experienced by children is associated with conventional therapy, co-reported with dosing regimen, adherence, distress and pain. During adolescence, the burden becomes increasingly complex and multi-factorial, with an increasing psychological burden. In adults, conventional therapy co-reported with bone deformity and orthopaedic surgery, as well as pain, mobility, fatigue and dental problems, featured highly. Discussion Whilst our study was opportunistic in nature, it has highlighted the clear and distinctive evolution of the burden of XLH, transitioning from being therapy-oriented in childhood to multi-factorial in adolescence, and finally to adulthood with its high impact on need for other interventions, function and mobility. This qualitative thematic analysis enhances the understanding of the symptom and treatment burden of XLH.

Various food constituents have been proposed as disease-modifying agents for Alzheimer's disease (AD), due to epidemiological evidence of their beneficial effects, and for their ability to ameliorate factors linked to AD pathogenesis, namely by: chelating iron, copper and zinc; scavenging reactive oxygen species; and suppressing the fibrillation of amyloid-beta peptide (Aβ). In this study, nine different food constituents (l-ascorbic acid, caffeic acid, caffeine, curcumin, (-)-epigallocatechin gallate (EGCG), gallic acid, propyl gallate, resveratrol, and α-tocopherol) were investigated for their effects on the above factors, using metal chelation assays, antioxidant assays, and assays of Aβ42 fibrillation. An assay method was developed using 5-Br-PAPS to examine the complexation of Zn(II) and Cu(II). EGCG, gallic acid, and curcumin were identified as a multifunctional compounds, however their poor brain uptake might limit their therapeutic effects. The antioxidants l-ascorbic acid and α-tocopherol, with better brain uptake, deserve further investigation for specifically addressing oxidative stress within the AD brain.

Background Bile acids (BAs) are known mediators of glucose metabolism that are altered in type 2 diabetes mellitus (T2DM) and gestational diabetes mellitus (GDM). We hypothesised that post-prandial BA fractions are changed in women with Insulin resistance (IR) after recovery from GDM using homeostatic model assessment (HOMA-IR). Methods 45 women median age 44(31–47) with previous GDM, including 20 with HOMA-IR >2.8 and 25 age-matched controls with HOMA-IR ≤ 2.8 were studied. After an overnight fast, all underwent an oral glucose tolerance test . Blood samples were collected at baseline and every 30 min for 120 min and analysed for glucose on automated platform and for total BAs, their conjugates and fractions using liquid-chromatography tandem mass-spectrometry. Baseline samples were analysed for insulin on automated platform. Delta (Δ) change (difference between baseline and maximal post-prandial response) were calculated. Data is presented as median (IQR). Results Fasting primary and unconjugated BAs were higher in women with HOMA-IR >2.8 vs. those with HOMA-IR ≤ 2.8 [0.24 (0.16–0.33) vs 0.06(0.04–0.22) μmol/L and 0.91(0.56–1.84) μmol/L vs. 0.69(0.32–0.89) μmol/L respectively. ∆ taurine-conjugated BAs was higher in women with HOMA-IR ≤ 2.8 than those with HOMA-IR > 2.8 [0.33(0.20–0.54) vs 0.23(0.13–0.34) μmol/L]. Fasting glucose and non-12α-hydroxylated BAs were negatively correlated in women with HOMA-IR >2.8 (all p Conclusions Following GDM, individuals with HOMA-IR >2.8 have altered conjugated and non-12α-hydroxylated fractions of BAs. It remains to be elucidated if the altered BA metabolism is a contributing factor to the pathogenesis or a consequence of GDM.

Genetic forms of vitamin D-dependent rickets (VDDRs) are due to mutations impairing activation of vitamin D or decreasing vitamin D receptor responsiveness. Here we describe two unrelated patients with early-onset rickets, reduced serum levels of the vitamin D metabolites 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D, and deficient responsiveness to parent and activated forms of vitamin D. Neither patient had a mutation in any genes known to cause VDDR; however, using whole exome sequencing analysis, we identified a recurrent de novo missense mutation, c.902T>C (p.I301T), in CYP3A4 in both subjects that alters the conformation of substrate recognition site 4 (SRS-4). In vitro, the mutant CYP3A4 oxidized 1,25-dihydroxyvitamin D with 10-fold greater activity than WT CYP3A4 and 2-fold greater activity than CYP24A1, the principal inactivator of vitamin D metabolites. As CYP3A4 mutations have not previously been linked to rickets, these findings provide insight into vitamin D metabolism and demonstrate that accelerated inactivation of vitamin D metabolites represents a mechanism for vitamin D deficiency.

The determination of both the water-soluble and lipid-soluble vitamin D compounds in human biological fluids is necessary to illuminate potentially significant biochemical mechanisms. The lack of analytical methods to quantify the water-soluble forms precludes studies on their role and biological functions; currently available liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods are able to determine only a single sulfated form of Vitamin D. We describe here a highly sensitive and specific LC-MS/MS method for the quantification of four sulfated forms of vitamin D: vitamins D2- and D3-sulfate (D2-S and D3-S) and 25-hydroxyvitamin D2- and D3-sulfate (25(OH)D2-S and 25(OH)D3-S). A comparative evaluation showed that the ionization efficiencies of underivatized forms in negative ion mode electrospray ionisation (ESI) are superior to those of the derivatized (using 4-phenyl-l,2,4-triazoline-3,5-dione (PTAD)) forms in positive ion mode ESI. Separation was optimised to minimise co-elution with endogenous matrix compounds, thereby reducing ion suppression/enhancement effects. Isotopically labelled analogues of each compound were used as internal standards to correct for ion suppression/enhancement effects. The method was validated and then applied for the analysis of breastmilk and human serum. The detection limits, repeatability standard deviations, and recoveries ranged from 0.20 to 0.28fmol, 2.8 to 10.2%, and 81.1 to 102%, respectively.

Mango fruit contain many bioactive compounds, some of which are transcription factor regulators. Estrogen receptor alpha (ERα) and beta (ERβ) are two regulators of gene transcription that are important in a variety of physiological processes and also in diseases including breast cancer. We examined the ability of the mango constituents quercetin, mangiferin, and the aglycone form of mangiferin, norathyriol, to activate both isoforms of the estrogen receptor. Quercetin and norathyriol decreased the viability of MCF-7 breast cancer cells whereas mangiferin had no effect on MCF-7 cells. We also determined that quercetin and mangiferin selectively activated ERα whereas norathyriol activated both ERα and ERβ. Despite quercetin, mangiferin and norathyriol having similar polyphenolic structural motifs, only norathyriol activated ERβ, showing that bioactive agents in mangoes have very specific biological effects. Such specificity may be important given the often-opposing roles of ERα and ERβ in breast cancer proliferation and other cellular processes.

Forty-five strains from two different species (Salinispora arenicola and Salinispora pacifica) were isolated from three different marine sponge species in the Great Barrier Reef region of Australia. We found that two of the strains of Salinispora arenicola (MV0335 and MV0029) produced mevinolin, a fungus-derived cholesterol-lowering agent. Compound structure was determined using an integrated approach: (a) high performance liquid chromatography-quadrupole time-of-flight-mass spectrometric analysis with multimode ionization (electrospray ionization and atmospheric pressure chemical ionization) and fast polarity switching; and (b) database searching and matching of monoisotopic masses, retention times and mass spectra of the precursor and product ions of the compounds of interest and the authentic reference standards thereof.

The occurrence of vitamin D deficiency has become an issue of serious concern in the worldwide population. As a result numerous analytical methods have been developed, for a variety of matrices, during the last few years to measure vitamin D analogs and metabolites. This review employs a comprehensive search of all vitamin D methods developed during the last 5 years for all applications, using ISI Web of Science®, Scifinder®, Science Direct, Scopus and PubMed. Particular emphasis is given to sample-preparation methods and the different forms of vitamin D measured across different fields of applications such as biological fluids, food and pharmaceutical preparations. This review compares and critically evaluates a wide range of approaches and methods, and hence it will enable readers to access developments across a number of applications and to select or develop the optimal analytical method for vitamin D for their particular application.

The controlled release of diflunisal and fluconazole from tablets made of novel polymers, poly(acrylic acid) (PAA) crosslinked with either β-cyclodextrin (βCD) or hydroxypropyl-βCD (HPβCD), was investigated and Carbopol 934P (Carbopol) was used as a highly crosslinked PAA for comparison. Diflunisal strongly associates with βCD-PAA and HPβCD-PAA polymers (Ka of 486 and 6,055 M(-1) respectively); thus, it was physically mixed into the conjugates and also precomplexed to identify whether decomplexation has any influence on release kinetics. Fluconazole has poor complexing ability (Ka of 34 M(-1) with HPβCD-PAA); thus, it was only tested as a physical mixture. Swelling and adhesion studies were conducted on all tablet combinations and adhesivity of the CD-PAA polymer tablets was maintained. Diflunisal release was much slower from HPβCD-PAA tablets than from βCD-PAA, suggesting that a higher degree of complexation retards release. The precomplexed diflunisal release was also slower than the physically mixed diflunisal of the corresponding conjugate. The release closely followed zero-order kinetics for HPβCD-PAA, but was more sigmoidal for βCD-PAA and especially Carbopol. Conversely, poorly associating fluconazole released in almost exactly the same way across both polymers and Carbopol, indicating that the release kinetics of poorly associating drugs are not influenced by the presence of cyclodextrins. In view of the varying profiles and release rates shown with diflunisal for the different polymers, the fluconazole data support the concept that adequate complexation can indeed modulate the release kinetics of drugs.

The developmental cycle of the obligate marine antibiotic producer actinobacterium Salinispora arenicola isolated from a Great Barrier Reef marine sponge was investigated in relation to mycelium and spore ultrastructure, synthesis of rifamycin antibiotic compounds, and expression of genes correlated with spore formation and with rifamycin precursor synthesis. The developmental cycle of S. arenicola M413 on solid agar medium was characterized by substrate mycelium growth, change of colony color, and spore formation; spore formation occurred quite early in colony growth but development of black colonies occurred only at late stages, correlated with a change in spore maturity in relation to cell wall layers. Rifamycins were detected throughout the growth cycle, but changed in relative quantity at particular phases in the cycle, with a marked increase after 32 days. Expression of the spore division gene ssgA and the rifK gene for 3-amino-5-hydroxybenzoate synthase responsible for rifamycin precursor synthesis was seen even at early stages of the growth cycle. ssgA expression significantly increased between days 26 and 31, but rifK expression effectively remained constant throughout the growth cycle, consistent with the early synthesis of rifamycin. Factors other than precursor synthesis may be responsible for an observed late increase in rifamycin production. A useful approach for measuring and exploring the regulation of antibiotic synthesis and gene expression in the marine natural product producer S. arenicola has been established.

The retention behaviour of a series of 28 monosubstituted benzenes, representing a diverse range of functional groups and substituent shape, were investigated using porous graphitic carbon (PGC) and octadecyl-bonded silica (ODS) stationary phases. For the majority of analytes retention on PGC was greater than on ODS, and in most cases this effect occurred at both pH 2.5 and 7.0. The main trends observed on PGC (in comparison with ODS) were: (i) similar or reduced retention of low polarity molecules such as the hydrocarbon and halogenated analytes; (ii) increased retention of conjugated analytes with extended planarity; (iii) increased retention of polar and charged species; and (iv) substantial increases in retention for selected polar and negatively charged analytes, including some ionised and unionised acid analytes. Poor retention of positively charged analytes was observed on both stationary phases. Molecular modelling studies have explored the geometry of π – π stacking interactions in retention on PGC and have highlighted the strong retention of large conjugated analytes, with extended planar conformations, which can interact with the graphite surface with cofacial geometry. Quantitative structure–retention relationships showed the importance of hydrophobic ( π ) and electronic factors (e.g. mean polarisability and LUMO energy) in retention on PGC, whilst retention on ODS was correlated to hydrophobicity (log P and π ).

A study was undertaken to investigate the enzyme-sensitive cleavage sites of β-END (1-31) in serum and in peripheral inflamed tissue. Inflammatory rat paw tissue was homogenized either with PBS (pH 7 .4) or MES (pH 5.5) buffer (1 mg tissue: 10ml buffer) and centrifuged. Rat β-END ( 1-31) was added to the resultant supenatants of the inflamed tissue extracts (to a final concentration of 0.1 mM) and to rat serum (to a final concentration of 74 μM). All samples were incubated at 37°C. Following incubation periods ranging from 0 min to 120 min, a sample (100 μL) was withdrawn and the protein precipitated by the addition of trichloroacetic acid. Each sample was centrifuged and resultant supernatant was analyzed with LC-MS (total ion current spectra) and LC-MS- MS (fragmented ion spectra). The primary enzymatic cleavage of β-END in rat serum occurs mainly at 16- 17-18-19-20 region that represents the amino acids Thr-Leu-Phe-Lys-Asn. For all primary fragments, the cleavage sites observed at pH 7.4 with inflamed tissue (except Lys-Ser at 9-10 position) were similar to those observed with rat serum. At pH 5.5, in addition to the cleavage sites detected in serum and in inflamed tissue at pH 7 .4, other sites were detected. These fragments were produced as a result of hydrolysis of β-END ( 1-31) by a variety of enzymes in the serum and inflammatory tissue. It is possible that the additional cleavage sites detected at pH 5.5 may be due to the enhanced enzymatic activity generated by the acidic environment of the inflammatory matrix.

In this manuscript, we present a simple and reliable method for the quantitation of para-aminohippuric acid (PAH; 2-(4-aminobenzamido)acetic acid) in human plasma and urine using liquid chromatography coupled to electrospray ionisation low-energy collision-induced dissociation tandem mass spectrometry (HPLC-ESI-CID-MS/MS) analysis (negative ion mode) via multiple reaction monitoring (MRM). Sample preparation involved protein precipitation of plasma samples with acetonitrile and subsequent dilution of urine samples with the mobile phase. The internal standard (IS) adopted was para-aminosalicylic acid (PAS; 4-amino-2-hydroxybenzoic acid). Chromatographic separation was achieved on a Cosmosil HILIC column using an isocratic mobile phase consisting of ammonium acetate buffer (20mM) and acetonitrile (45:55, v/v) at a flow rate of 200microl/min. The transactions monitored were m/z 192.9-->149.1 for PAH and m/z 152.1-->108.1 for IS. Linear calibration curves were generated over the PAH concentration range of 0.2-100mg/L in human plasma and urine. The method was validated for selectivity, accuracy, precision, recovery and stability according to USFDA criteria, and has been successfully applied to a pharmacokinetic study in healthy volunteers administered an intravenous dose of 440mg PAH.

HPLC-MS-MS has been used for the identification and characterisation of rifamycin B and rifamycin SV in various strains of the marine sponge-derived bacterium Salinispora. Gradient elution using acetonitrile/water/ammonium acetate was used to separate the rifamycins from the matrix and negative ion-electrospray mass spectrometry was used for detection and confirmation. The presence of rifamycin in bacterial extracts was confirmed by matching retention times, parent ion spectra and the fragmentated parent ion spectra of the standard compounds and the bacterial extracts. All strains of the marine sponge bacterium Salinispora tested were found to contain rifamycin thus an alternate actinobacterial source of rifamycin was established.

Background: Wolcott-Rallison syndrome is a rare autosomal recessive condition characterized by early infancy onset diabetes mellitus and multiple epiphyseal dysplasia. So far, 17 children have been described in the world literature. Recently, mutations in the gene encoding EIF2AK3 have been shown to segregate with the syndrome in three affected families. Aims: We aimed to describe the clinical characterization and mutation analysis of a further child, and full clinical and follow-up details on our first family including the longest surviving child. Methods: Retrospective case notes review of three children presenting to the diabetic unit at our institution; mutation analysis of the EIF2AK3 gene in our most recent patient; and review of the literature on Wolcott-Rallison syndrome. Results: Previously unreported phenotypic features in our patients included developmental regression after episodes of hepatic failure, and pachygyria on brain imaging. We have identified a novel 4-base pair deletion (nt 3021–3024 del GAGA) in exon 13, which results in a frameshift and premature stop codon (R908 F/S +22X), causing premature truncation of the protein and abolition of the carboxy- segment of the catalytic domain. Conclusions: Wolcott-Rallison syndrome causes early-onset diabetes and acute hepatic failure, before epiphyseal dysplasia is manifest. We have identified a novel mutation in EIF2AK3, and prenatal diagnosis may now be offered to affected families.

A quantitative liquid chromatography positive ion electrospray tandem mass spectrometric method for the simultaneous determination of sulforaphane, iberin and their metabolites in human urine and plasma is described. The stability of the metabolites was determined in aqueous solution and in human plasma. Gradient liquid chromatographic separation was performed on a Zorbax SB-Aq 3.5 microm (100 x 2.1mm) column, using a mobile phase (flow rate 0.25 mL/min) consisting of ammonium acetate buffer at pH 4 and acetonitrile. Butyl thiocarbamoyl l-cysteine was used as internal standard. The assay was linear (r(2)>0.99) over the range of 0.03-300 microM in urine and 0.03-15 microM in plasma with intra- and inter-day assay precision (

Hydrogen sulfide (H2S) has been shown to have a potential protective role in a number of disease states including diabetes and various kidney disorders; however, the mechanisms involved are still unclear. The aim of this study was to investigate if H2S effects the expression of the antioxidant enzyme heme oxygenase-1 (HO-1) in human kidney cells. Human mesangial cells and human podocytes were cultured at normal physiological glucose concentration (5.5 mM) and then treated with different H2S donors for a 24-h period. Protein was then extracted from the cells, and the expression levels of HO-1 determined by Western blotting. There was a significant increase in HO-1 expression after treatment with the H2S donors in both mesangial and podocyte cells. These results suggest that H2S has a role in the regulation of HO-1 expression, and the ability to upregulate this antioxidant enzyme maybe a potential mechanism by which H2S exerts its protective effects.

Five chiral stationary phases were prepared by coating the surface of porous graphitic carbon with a series of N-substituted l -proline chiral selectors. The N-substituents served as anchor molecules for immobilization of chiral selectors on the support material. The effect of the alkyl (C7, C9, C12) and aryl (naphthylmethyl, anthrylmethyl) anchor molecules on retention and enantioselectivity were studied using thirty-six amino acid enantiomers as probe compounds. The surface concentrations of the chiral selectors, determined using the breakthrough method, were found to be in the range 0.39–0.68 μmol m−2. The coated PGC phases all showed appreciable enantioselectivity for both non-polar and acidic amino acids with the naphthylmethyl- l -proline showing the greatest overall values. The N-substituents were shown to have strong influence on retention and enantioselectivity. An increase in the chain length of the alkyl N-substituents resulted in improved enantioselectivity whereas the retention decreased. However, with the aryl N-substituents, both the retention and enantioselectivity decreased with an increase in the ring number of the aryl substituent. The retention order for the majority of the amino acids examined was the same on all the columns, that is d > l . These behaviours were interpreted in terms of the involvement of the N-substituent in intramolecular hydrophobic interactions responsible for the observed chiral recognition.

Six chiral stationary phases were prepared by coating the surface of porous graphitic carbon (PGC) with a series of N-substituted l -phenylalanine chiral selectors. The N-substituents served as anchor molecules for immobilization of chiral selectors on the support material. The effect of the alkyl (C7, C9, C12) and aryl (methoxybenzyl, naphthylmethyl, anthrylmethyl) anchor molecules on retention and enantioselectivity was studied using 36 amino acid enantiomers as probe compounds. The surface concentrations of the chiral selectors, determined using the breakthrough method, were found to be in the range 0.55–1.26 μmol/m2. The coated PGC phases all showed appreciable enantioselectivity for both non-polar and acidic amino acids, but basic amino acids were predominantly unretained. The order of retention of a pair of amino acid enantiomers was l > d on the alkyl- l -phenylalanine phases but a reversed retention order ( d > l ) was observed aryl-substituted l -phenylalanine phases. The chromatographic properties of each of the chiral stationary phases were compared in terms of retention order, enantioselectivity and diastereomeric complex stability. The reversal of the elution order on these two types of phases is discussed in relation to competitive intramolecular interactions involved in transient diasteriomeric complexes.

The effect of the chain length (C 1 –C 18 ) of η-alkyl bonded-phase silica packing materials on retention behavior is investigated using three series of substituted test solutes: biphenyls (neutral), barbitu­ rates (weakly acidic), and pyridines (weakly basic). An excellent correlation between the capacity factor (k) and alkyl chain length is observed in the majority of cases. However, deviations from this re­ lationship occur when the alkyl chain length is increased beyond C 8 for certain groups of solutes or when there is significant solute in­ teraction at secondary sites on the packing material. Log k plots showed that the neutral and barbiturate solutes have similar reten­ tion mechanisms at all the alkyl chain lengths. However, the basic solutes show significant evidence of secondary interactions, which are confirmed by the peak asymmetry data and the lack of correla­ tion between the log 10 octanol-water partition coefficient (log P) values of the solutes and retention. There is a significant trend to­ wards improved peak symmetry for the basic solutes when the packing materials having the highest alkyl surface density (C l ,C 2, and C3 alkyl chain lengths) are used; this suggests that residual silanols are more effectively masked by the shorter alkyl chain lengths. The neutral biphenyl solutes show a progressive increase in efficiency as the chain length increases, but consistent trends are not observed for the acidic and basic solutes. The results show that the length of the bonded alkyl chain is of primary, though not sole, importance in governing the retention of acidic, basic, and neutral compounds on a series of monofunctional n-alkyl-bonded reversedphase packing materials. Retention mechanisms that might explain the observed separation behavior are discussed.

Dysosteosclerosis (DSS) is the form of osteopetrosis distinguished by the presence of skin findings such as red-violet macular atrophy, platyspondyly and metaphyseal osteosclerosis with relative radiolucency of widened diaphyses. At the histopathological level, there is a paucity of osteoclasts when the disease presents. In two patients with DSS, we identified homozygous or compound heterozygous missense mutations in SLC29A3 by whole-exome sequencing. This gene encodes a nucleoside transporter, mutations in which cause histiocytosis-lymphadenopathy plus syndrome, a group of conditions with little or no skeletal involvement. This transporter is essential for lysosomal function in mice. We demonstrate the expression of Slc29a3 in mouse osteoclasts in vivo. In monocytes from patients with DSS, we observed reduced osteoclast differentiation and function (demineralization of calcium surface). Our report highlights the pleomorphic consequences of dysfunction of this nucleoside transporter, and importantly suggests a new mechanism for the control of osteoclast differentiation and function.

A total synthesis of (±)-9-mercaptodethiobiotin 3via the aldehyde 9 is described. Compound (±)-3 does not function as a biotin replacement factor for an E. coli mutant (SA291) lacking the entire biotin synthesis operon (bioABFCD–) but supports growth of an E. coli bioA mutant. Compound (±)-3 also supports growth of transformed cells of SA291 carrying a plasmid encoding the E. coli biotin synthase (bioB) gene indicating that the compound may be able to substitute for dethiobiotin 2 as a substrate for biotin synthase.

Homochiral ethynyl tyrosine 2, designed as a potential dopamine β-hydroxylase irreversible inhibitor prodrug, has been synthesised asymmetrically in 15-steps, using the alkylation and azidation of acylated oxazolidones to establish relative and absolute stereochemistry.

ATP-citrate lyase is the primary enzyme responsible for the synthesis of cytosolic acetyl-CoA in many tissues. Inhibitors of the enzyme represent a potentially novel class of hypolipidemic agent, which are anticipated to have combined hypocholesterolemic and hypotriglyceridemic properties. A series of 2-substituted butanedioic acids have been designed and synthesized as inhibitors of the enzyme. The best compounds, 58, 68, 71, 74 have reversible Ki's in the 1-3 microM range against the isolated rat enzyme. As representative of this compound class, 58, has been shown to exert its inhibitory action through a mainly competitive mechanism with respect to citrate and a noncompetitive one with respect to CoA. None of the inhibitors were able to inhibit cholesterol and/or fatty acid synthesis in HepG2 cells. This has been attributed to the adverse physicochemical properties of the molecules leading to a lack of cell penetration. Despite this, a lead structural class of compound has been identified with the potential for modification into potent, cell-penetrant, and efficacious inhibitors of ATP-citrate lyase.

The retention behaviour of a series of 15 n-alkylbenzenes and pentylbenzene structural isomers and benzene were investigated using porous graphitic carbon (PGC) and octadecyl-bonded silica (ODS) stationary phases. Shorter chain n-alkylbenzenes and benzene (n = 0-6), and all the pentylbenzene isomers were more strongly retained on ODS, although the selectivity was greater with PGC. For the pentylbenzene analytes the degree of branching in the alkyl chain at the position adjacent to the aromatic ring affects retention on PGC, with higher retention in less branched molecules. Molecular modelling studies have provided new insights into the geometry of aromatic pi-pi stacking interactions in retention on PGC. For alkylbenzenes with high branching at the position adjacent to the ring, the preferred geometry of association with the surface is with the branched chain directed away from the surface, a geometry not seen in the other alkylbenzenes. The most energetically favoured orientation for interaction between analytes and the PGC surface was found to be cofacial for toluene and ethylbenzene, whereas for other analytes this interaction was in a face-edge orientation. The alternative geometry of association observed with both toluene and ethylbenzene may explain the enhanced retention of these two analytes on PGC compared with their longer chain analogues. Quantitative structure-retention relationships revealed the importance of compactness in analyte structure during retention on PGC, with decreased compactness (associated with longer chain length and reduced chain branching) improving retention. (c) 2010 Elsevier B.V. All rights reserved.

ObjectiveGH insensitivity (GHI) is caused in the majority of cases by impaired function of the GH receptor (GHR). All but one knownGHRmutation are in the coding sequence or the exon/intron boundaries. We identified and characterised the first intronic defect occurring in the polypyrimidine tract of theGHRin a patient with severe GHI.DesignWe investigated the effect of the novel defect on mRNA splicing using anin vitrosplicing assay and a cell transfection system.MethodsGHRwas analysed by direct sequencing. To assess the effect of the novel defect, two heterologous minigenes (wild-type and mutant L1-GHR8-L2) were generated by insertingGHRexon 8 and its flanking wild-type or mutant intronic sequences into a well-characterised splicing reporter (Adml-par L1–L2).32P-labelled pre-mRNA was generated from the two constructs and incubated in HeLa nuclear extracts or HEK293 cells.ResultsSequencing of theGHRrevealed a novel homozygous defect in the polypyrimidine tract of intron 7 (IVS7-6T>A). This base change does not involve the highly conserved splice site sequences, and is not predictedin silicoto affect GHR mRNA splicing. Nevertheless, skipping of exon 8 from the mutant L1-GHR8-L2 mRNA was clearly demonstrated in thein vitrosplicing assay and in transfected HEK293 cells.ConclusionDisruption of theGHRpolypyrimidine tract causes aberrant mRNA splicing leading to a mutant GHR protein. This is predicted to lack its transmembrane and intracellular domains and, thus, be incapable of transducing a GH signal.

The hypoparathyroidism-deafness-renal (HDR) dysplasia syndrome is an autosomal dominant disorder caused by mutations of the dual zinc finger transcription factor, GATA3. We investigated 21 HDR probands and 14 patients with isolated hypoparathyroidism for GATA3 abnormalities. Thirteen different heterozygous germline mutations were identified in patients with HDR. These consisted of three nonsense mutations, six frameshifting deletions, two frameshifting insertions, one missense (Leu348Arg) mutation and one acceptor splice site mutation. The splice site mutation was demonstrated to cause a pre-mRNA processing abnormality leading to the use of an alternative acceptor site 8 bp downstream of the normal site, resulting in a frameshift and prematurely terminated protein. Electrophoretic mobility shift assays (EMSAs) revealed three classes of GATA3 mutations: those that lead to a loss of DNA binding which represent over 90% of all mutations, and involved a loss of the carboxy-terminal zinc finger; those that resulted in a reduced DNA-binding affinity; and those (e.g. Leu348Arg) that did not alter DNA binding or the affinity but likely altered the conformational change that occurs during binding in the DNA major groove as predicted by a three-dimensional modeling. These results elucidate further the molecular mechanisms underlying the altered functions of mutants of this zinc finger transcription factor and their role in causing this developmental anomaly. No mutations were identified in patients with isolated hypoparathyroidism, thereby indicating that GATA3 abnormalities are more likely to result in two or more of the phenotypic features of the HDR syndrome and not in one, such as isolated hypoparathyroidism.

A simple, rapid and sensitive reversed-phase liquid chromatography method coupled to electrospray ionization mass spectrometry has been developed for studying the in vitro metabolism of the long-chain quaternary ammonium compounds dodecyltrimethylamine, tetradecyltrimethylamine and hexadecyltrimethylamine. Samples were prepared from the biological matrix by a simple protein precipitation stage. The separation was performed using a BDS Hypersil C8 3 microm particle size (100 x 3 mm i.d.) column with a fast gradient separation (60% B to 100% B) using a mobile phase of 10 mm aqueous ammonium acetate (pH 4.0, with 0.06% triethylamine; (A)-acetonitrile (B) at 0.7 mL min(-1). To minimize contamination of the MS source a switching value was used to divert the solvent front to waste. Decylammonium bromide was used as the internal standard and analytes were identified and quantified by positive ion electrospray selected ion monitoring of their intact molecular cations. The assay had a limit of quantitation of 0.25 microm (6.25 pmol on column) and was linear over the range 0.25--100 microm assay concentration for this series of long-chain quaternary amines. The precision of intra- and inter-day assays was better than 19% and the accuracy was between 93 and 109%. The method was used to assess the in vitro metabolism of the quaternary amines by wild-type cytochrome P450 enzyme CYP 4 A 1 and mutants in an artifical membrane system.

Biotechnology has become an indispensable tool for the production of fine chemicals. The choice of route, chemical or biotechnological, for the manufacture of a given fine chemical is crucial. In general terms, biotechnology is the method of choice for large molecules with a high degree of functionalisation and multiple stereocentres. Most of LONZA's biotechnological bioprocesses for the production of fine chemicals are whole cell processes using microorganisms which form very specific enzymes. Process improvement at LONZA is discussed in this paper on three levels: upstream processing, biotransformation/biosynthesis, and downsteam processing.

C-S lyase enzymes catalyse the generation of mutagenic and/or cytotoxic thiols from cysteine conjugated xenobiotics. These cysteine conjugates are produced subsequent to glutathione conjugations as a metabolic step in the mercapturic acid pathway, traditionally thought of as a pathway solely associated with detoxification. Human Chang liver (HCL) cells were challenged with a range of cysteine conjugates demonstrated to be substrates for human hepatic C-S lyases. The cellular toxicity of these compounds was determined and it was observed that the rank order of substrate toxicity obtained for the HCL cells followed the rank order of C-S lyase activity of the substrates in a freshly isolated mitochondrial fraction of human tissue. The presence of C-S lyase activity was also established in this cell line.

The C-S lyase enzymes are responsible for the generation of mutagenic and cytotoxic metabolites via aberrant drug-metabolising pathways in mammalian tissues. We have examined human hepatic cytosolic, mitochondrial and microsomal fractions for evidence of C-S lyase activity. The cytosolic enzyme was purified using fast protein liquid chromatography over FFQ Sepharose, Mono P and Superose 12. An homogeneous protein (monitored by SDS-PAGE) was obtained following purification, and an 11-fold increase in C-S lyase specific activity was observed. The molecular weight of the enzyme was found to be 37 kDa in denaturing conditions, 82.3 kDa in non-denaturing conditions, and the C-S lyase activity was shown to co-purify with kynurenine aminotransferase activity when the transaminase activity of the enzyme was examined with kynurenine as the substrate.

The enzyme cysteine conjugate /.I-lyase (C-S lyase, EC 4.4.1.13) from rat renal tissue has been identified as a transaminase: glutamine transaminase K (GTK) [l]. This is one member of a family of enzymes which effect a transamination reaction on amino acid substrates. Other members of this family include glutamine transaminase L (GTL, isolated from rat liver, but which has a structure-activity profile broadly overlapping that of GTK), kynurenine aminotransferase (KAT), and aspartate aminotransferase. Rat hepatic cytosolic C-S lyase co-purifies as kynureninase, an enzyme which is involved in anthranilic acid biosynthesis [2], but antibodies raised against this purified protein did not crossreact with the renal cytosolic enzyme (i.e. with GTK). In one study with human hepatic cytosolic C-S lyase [3], kynurenine was not a substrate for the enzyme. These workers did not establish whether the C-S lyase enzyme had a physiological role, and if it co-purified with a protein which had been previously characterized. We have recently established that human hepatic cytosolic C-S lyase co-purifies as an aminotransferase: KAT [4]. In this article, we discuss the structureactivity relationships displayed by human C-S lyases obtained from both the cytosolic and mitochondrial sub-cellular fractions of kidney, liver and lung tissue. Elsewhere

To explore a pharmacy school curriculum for opportunities for student engagement and to determine how these might shape student identity as pharmacists.The learning aims and objectives and methods of assessment from the curriculum of a bachelor of pharmacy (BPharm) program were collected and a concept map was generated. The concept map was interpreted using Barnett and Coates' curricular domains of knowing, acting and being.The key concepts within the intended curriculum that were identified from the concept map were drugs, pharmacy, understanding, practice, and skills. Concepts such as patient and consumer, which would indicate a patient-centered approach to the curriculum, were limited. The main form of assessment used in the curriculum was multiple-choice and short-answer examinations.There was an emphasis in the curriculum on student acquisition of knowledge and this was reinforced by the use of theoretical examinations. The content of the curriculum was drug-centered rather than patient-centered and the emergence of students' identity as pharmacists may be fragmented as a result.