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Despite its critical role in neurodevelopment and brain function, vitamin D (vit-D) homeostasis, metabolism, and kinetics within the central nervous system remain largely undetermined. Thus, it is of critical importance to establish an accurate, highly sensitive, and reproducible method to quantitate vit-D in brain tissue. Here, we present a novel liquid chromatography tandem mass spectrometry (LC-MS/MS) method and for the first time, demonstrate detection of seven major vit-D metabolites in brain tissues of C57BL/6J wild-type mice, namely 1,25(OH)2D3, 3-epi-1,25(OH)2D3, 1,25(OH)2D2, 25(OH)D3, 25(OH)D2, 24,25(OH)2D3, and 24,25(OH)2D2. Chromatographic separation was achieved on a pentaflurophenyl column with 3 mM ammonium formate water/methanol [A] and 3 mM ammonium formate methanol/isopropanol [B] mobile phase components. Detection was by positive ion electrospray tandem mass spectrometry with the EVOQ elite triple quadrupole mass spectrometer with an Advance ultra-high-performance liquid chromatograph and online extraction system. Calibration standards of each metabolite prepared in brain matrices were used to validate the detection range, precision, accuracy, and recovery. Isotopically labelled analogues, 1,25(OH)2D3-d3, 25(OH)D3-c5, and 24,25(OH)2D3-d6, served as the internal standards for the closest molecular-related metabolite in all measurements. Standards between 1 fg/mL and 10 ng/mL were injected with a resulting linear range between 0.001 and 1 ng, with an LLOD and LLOQ of 1 pg/mL and 12.5 pg/mL, respectively. The intra-/inter-day precision and accuracy for measuring brain vit-D metabolites ranged between 0.12–11.53% and 0.28–9.11%, respectively. Recovery in acetonitrile ranged between 99.09 and 106.92% for all metabolites. Collectively, the sensitivity and efficiency of our method supersedes previously reported protocols used to measure vit-D and to our knowledge, the first protocol to reveal the abundance of 25(OH)D2, 1,25(OH)D2, and 24,25(OH)2D2, in brain tissue of any species. This technique may be important in supporting the future advancement of pre-clinical research into the function of vit-D in neurophysiological and neuropsychiatric disorders, and neurodegeneration. Graphical Abstract

Chemical pollution arising from heavy metals and metalloids is a growing global concern and a major cause of pollution-related diseases in the world today, especially in low- and middle-income countries. The present study investigated the urinary concentrations of metals and metalloids in primary school-aged children (N = 142), living in three different industrialised areas, namely the textile, tannery, and multiple industries dominated areas of Dhaka, Bangladesh and compared with a control area. The accurate measurement of urinary concentrations of twenty-two elements was accomplished using a simple and robust ICP-MS method; hydration variations were adjusted by osmolality. Results revealed that children living in these industrialised areas were exposed to a greater extent the environmental pollutants arsenic, chromium, iron, selenium, molybdenum, tin, caesium, thallium, and lead when compared to control children, after adjusting of confounding factors such as age, sex, and nutritional status. The higher concentrations of manganese in urine (3.81 µg/L, p < 0.0001) and in drinking water samples (131.0 µg/L, p < 0.05) of the textile area, suggest an elevated risk of adverse health effects for the exposed children noting that about 70% of the drinking water samples exceeded the national recommended limit. In addition, the concentration of copper was positively correlated between drinking water and urine samples which may potentially indicate the source of exposure. This study represents the prevailing situation of metals and metalloid pollution in industrialised areas where children may be at a higher risk of heavy metal-induced health problems.

The Earth’s subsurface not only provides a wide range of natural resources but also contains large pore volume that can be used for storing both anthropogenic waste and energy. For example, geothermal energy may be extracted from hot water contained or injected into deep reservoirs and disused coal mines; CO2may be stored within depleted petroleum reservoirs and deep saline aquifers; nuclear waste may be disposed of within mechanically stable impermeable strata; surplus heat may be stored within shallow aquifers or disused coal mines. Using the subsurface in a safe manner requires a fundamental understanding of the physiochemical processes which occur when decarbonising technologies are implemented and operated. Here, thermal, hydrological, mechanical and chemical perturbations and their dynamics need to be considered. Consequently, geoscience will play a central role in Society’s quest to reduce greenhouse gas emissions. This contribution provides a review of the physiochemical processes related to key technologies that utilize the subsurface for reducing greenhouse gas emissions and the resultant challenges associated with these technologies. Dynamic links between the geomechanical, geochemical and hydrological processes differ between technologies and the geology of the locations in which such technologies are deployed. We particularly focus on processes occurring within the lithologies most commonly considered for decarbonisation technologies. Therefore, we provide a brief comparison between the lithologies, highlighting the main advantages and disadvantages of each, and provide a list of key parameters and properties which have first order effects on the performance of specific rock types, and consequently should be considered during reservoir evaluation for decarbonising technology installation. The review identifies several key knowledge gaps that need to be filled to improve reservoir evaluation and performance prediction to be able to utilize the subsurface efficiently and sustainably. Most importantly, the biggest uncertainties emerge in prediction of fracture pattern development and understanding the extent and timescales of chemical reactions that occur within the decarbonising applications where external fluid or gas is cyclically injected and invariably causes disequilibrium within the system. Furthermore, it is clear that whilst geoscience can show us the opportunities to decarbonise our cities and industries, an interdisciplinary approach is needed to realize these opportunities, also involving social science, end-users and stakeholders.

Essential and nonessential element concentrations in human blood provide important information on the nutritional status of individuals and can assist in the screening or diagnosis of certain disorders and their association with other causative factors. A simple and sensitive method, suitable for use with small sample volumes, for quantification of multiple trace element concentrations in whole blood and plasma has been developed using inductively coupled plasma-mass spectrometry. Method validation was performed using standard reference materials of whole blood and serum using varying sample treatments with nitric acid, water and hydrogen peroxide. The method was applied to quantify the trace element concentrations in whole blood and plasma samples (0.1 mL) from 50 adult blood donors in Queensland. The whole blood sample (5 mL) was collected in Vacutainer tubes with K2EDTA as anticoagulant. The developed method was able to quantify, in blood and plasma samples over a wide range of concentrations, several essential elements: cobalt, copper, zinc, iron, manganese and selenium; the nutritionally probably essential elements vanadium and strontium; and nonessential elements including lead, cadmium, arsenic, caesium, barium, thallium and uranium. Significant differences (P

Distinct neural stem cells (NSCs) reside in different regions of the subventricular zone (SVZ) and generate multiple olfactory bulb (OB) interneuron subtypes in the adult brain. However, the molecular mechanisms underlying such NSC heterogeneity remain largely unknown. Here, we show that the basic helix-loop-helix transcription factor Olig2 defines a subset of NSCs in the early postnatal and adult SVZ. Olig2-expressing NSCs exist broadly but are most enriched in the ventral SVZ along the dorsoventral axis complementary to dorsally enriched Gsx2-expressing NSCs. Comparisons of Olig2-expressing NSCs from early embryonic to adult stages using single cell transcriptomics reveal stepwise developmental changes in their cell cycle and metabolic properties. Genetic studies further show that cross-repression contributes to the mutually exclusive expression of Olig2 and Gsx2 in NSCs/progenitors during embryogenesis, but that their expression is regulated independently from each other in adult NSCs. Finally, lineage-tracing and conditional inactivation studies demonstrate that Olig2 plays an important role in the specification of OB interneuron subtypes. Altogether, our study demonstrates that Olig2 defines a unique subset of adult NSCs enriched in the ventral aspect of the adult SVZ.

This article explores the intersections between propaganda, intelligence and covert action through the experience of Britain’s Regional Information Office (RIO) in Singapore. RIO defined its functi...

Traditional heating using non-renewable energy resources contributes up to 50% of current carbon emission level. Different sources of renewable energy are being exploited and developed to lower the carbon emission level for continuity of healthy living environment. It is found that thermal energy is stored in minewater flooding abandoned mines. The minewater can be extracted through newly drilled boreholes or existing mineshafts. To ensure successful and sustainable operation, mineshafts have to be structurally stable. When the mines are abandoned, the water level tends to recover. Some of the configurations of the minewater heat recovery may change the temperature of part of the shaft wall. This research aims to provide some insight on the stability of mineshafts for minewater heat recovery through numerical sensitivity analyses on: (a) water level, (b) temperature fluctuations. In the presented research work, rock masses with different properties have been analyzed. Change in temperature is found to mainly change the static Young’s Modulus of intact rock and the joint roughness. However, the joint roughness is expressed indirectly using the Geological Strength Index, which has direct relationship with joint roughness and is used in stability analysis. It is found that an increase in water level reduces the integrity of the whole shaft. The degrees of stability deterioration are different at different depths and depend on the in situ stress state. Findings of this analyses can be assist in making a decision on the selection of the appropriate configuration for minewater heat recovery.

Background: Independent peer review of healthcare services can complement existing internal-, institutional-, and national-level regulatory mechanisms aimed at improving quality of healthcare. However, this has not been reported for paediatric endocrinology services in the UK. We aimed to test feasibility and acceptability through a first cycle of a national peer review of paediatric endocrine services. Methods: Tertiary centres in paediatric endocrinology across the UK were assessed against 54 quality standards, developed by the British Society for Paediatric Endocrinology and Diabetes (BSPED) in five domains of healthcare by a team comprising paediatric endocrinologists and specialist nurses. The evaluation was supported by a self-assessment. A post-peer-review questionnaire was used as feedback. Results: All 22 centres in the UK underwent independent peer review between 2011 and 2017. Each served a median population of 2.6 million (range 1–8 million) and offered 1,872 (range 779–6,738) outpatient consultations annually. A total of 43 (range 30–49) standards were met in combined evaluation of all centres. Variance of adherence for essential standards ranged from 52 to 97% at individual centres with 90% adherence demonstrated by 32% of centres. Post-review feedback showed 20/22 (95%) validating the utility of the peer review. Conclusions: The BSPED peer review of all UK centres providing paediatric endocrine services is shown to be feasible and provides a quality benchmark for replication by national services.

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.

Purpose Middle leaders play an important role in the education landscape, first and foremost as teachers, and second as leaders. The purpose of this paper is to identify the expectations and challenges experienced by first-time middle leaders in New Zealand primary schools, and identify the leadership development and support they were provided with. Design/methodology/approach This was a small qualitative study designed to collect data from the perspectives of first-time middle leaders and principals in New Zealand primary schools. Three methods were employed. Semi-structured interviews were conducted with six middle leaders who had been in the role for one to three years. These participants were identified through an analysis of recent public appointment records and then e-mailed with an invitation. Four principals from a local principals’ association were invited to comprise a focus group and relevant documents were analysed. Findings The findings from this study are presented in three sections: expectations, challenges and leadership development and support. Whilst the principals described wide and varied role expectations the middle leaders highlighted the importance of their teaching role with leadership responsibilities as secondary. From both perspectives time to do the administrative work was an overwhelming difficulty. A key finding was related to a lack of confidence to undertake the role in spite of efforts to provide and receive support. Overall, there was agreement that further development for new middle leaders was essential. Research limitations/implications This small, limited study highlights the central role that middle leaders play in leading learning and teaching, and the existence of a lack of confidence. Further research is needed to delve into conditions that would enable new middle leaders to manage the challenges of time and confidence. Practical implications The research recommends that practitioners who are new to a middle leadership role be allocated dedicated time for performing the administrative tasks and participating in an ongoing induction programme. The middle leaders themselves and their schools would benefit from efforts to strengthen middle leadership development. Originality/value Although a great deal has been written about middle leadership, there is only a small amount of research about primary schools. This research adds valuable new information in a primary school context and breaks new ground in researching early career, first-time middle leaders in this context.

Background Knowledge of trace element stability during sample handling and preservation is a prerequisite to produce reliable test results in clinical trace element analysis. Method An alkaline dissolution method has been developed using inductively coupled plasma mass spectrometry to quantify eighteen trace element concentrations: vanadium, chromium, manganese, cobalt, nickel, copper, zinc, arsenic, selenium, bromine, molybdenum, cadmium, antimony, iodine, mercury, thallium, lead, and bismuth in human blood, using a small sample volume of 0.1 mL. The study evaluated the comparative effects of storage conditions on the stability of nutritionally essential and non-essential elements in human blood and plasma samples stored at three different temperatures (4 °C, −20 °C and −80 °C) over a one-year period, and analysed at multiple time points. The distribution of these elements between whole blood and plasma and their distribution relationships are illustrated using blood samples from 66 adult donors in Queensland. Results The refrigeration and freezing of blood and plasma specimens proved to be suitable storage conditions for many of the trace elements for periods up to six months, with essentially unchanged concentrations. Substantially consistent recoveries were obtained by preserving specimens at −20 °C for up to one year. Ultra-freezing of the specimens at −80 °C did not improve stability; but appeared to result in adsorption and/or precipitation of some elements, accompanied by a longer sample thawing time. A population sample study revealed significant differences between the blood and plasma concentrations of six essential elements and their relationships also varied significantly for different elements. Conclusion Blood and plasma specimens can be reliably stored at 4 °C for six months or kept frozen at −20 °C up to one year to obtain high quality test results of trace elements.

Cytochrome P450s (CYP450s) are a rapidly evolving family of enzymes, making it difficult to identify bona fide orthologs with notable lineage-specific exceptions. In ecdysozoans, a small number of the most conserved orthologs include enzymes which metabolize ecdysteroids. Ecdysone pathway components were recently shown in a decapod crustacean but with a notable absence of shade, which is important for converting ecdysone to its active form, 20-hydroxyecdysone (20HE), suggesting that another CYP450 performs a similar function in crustaceans. A CYPome temporal expression analysis throughout metamorphosis performed in this research highlights several un-annotated CYP450s displaying differential expression and provides information into expression patterns of annotated CYP450s. Using the expression patterns in the Eastern spiny lobster Sagmariasus verreauxi, followed by 3D modelling and finally activity assays in vitro, we were able to conclude that a group of CYP450s, conserved across decapod crustaceans, function as the insect shade. To emphasize the fact that these genes share the function with shade but are phylogenetically distinct, we name this enzyme system Shed.

Context Osteogenesis imperfecta (OI) is associated with reduced muscle size, dynamic muscle function, and mobility. Objective To assess the effect of whole body vibration (WBV) on bone density and geometry, muscle size and function, mobility, and balance in children with OI. Design Randomized controlled pilot trial. Setting Tertiary pediatric research center. Participants Twenty-four children (5 to 16 years) with OI types 1, 4, and limited mobility [Child Health Assessment Questionnaire (CHAQ) score ≥ 0.13] recruited in sex- and pubertal stage-matched pairs. Incident fractures in two boys (WBV arm) led to exclusion of two prepubertal pairs. Intervention Five months of WBV training (3 × 3 minutes twice daily) or regular care. Main Outcome Measures Bone and muscle variables measured by dual-energy X-ray absorptiometry (spine, hip, total body) and peripheral quantitative computed tomography (tibia). Mobility assessed by 6-minute walk tests and CHAQ; dynamic muscle function by mechanography. Results All participants had reduced walking distances and muscle function (P < 0.001). Body mass index z score was associated with higher CHAQ scores (ρ + 0.552; P = 0.005) and lower walking and two-leg jumping performance (ρ − 0.405 to −0.654, P < 0.05). The WBV and control groups did not differ in the 5-month changes in bone. Total lean mass increased more in the WBV group [+1119 g (+224 to +1744)] compared with controls [+635 g (−951 to +1006)], P = 0.01, without improving mobility, muscle function, or balance. Conclusions The increase in lean mass without changes in muscle function or bone mass suggests reduced biomechanical responsiveness of the muscle-bone unit in children with OI.

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.

The increasing use of dual-energy X-ray absorptiometry (DXA) in children has led to the need for robust reference data for interpretation of scans in daily clinical practice. Such data need to be representative of the population being studied and be "future-proofed" to software and hardware upgrades. The aim was to combine all available pediatric DXA reference data from seven UK centers to create reference curves adjusted for age, sex, ethnicity, and body size to enable clinical application, using in vivo cross-calibration and making data back and forward compatible. Seven UK sites collected data on GE Lunar or Hologic Scanners between 1996 and 2012. Males and females aged 4 to 20 years were recruited (n = 3598). The split by ethnic group was white 2887; South Asian 385; black Afro-Caribbean 286; and mixed heritage 40. Scans of the total body and lumbar spine (L1 to L4 ) were obtained. The European Spine Phantom was used to cross-calibrate the 7 centers and 11 scanners. Reference curves were produced for L1 to L4 bone mineral apparent density (BMAD) and total body less head (TBLH) and L1 to L4 areal bone mineral density (aBMD) for GE Lunar Prodigy and iDXA (sex- and ethnic-specific) and for Hologic (sex-specific). Regression equations for TBLH BMC were produced using stepwise linear regression. Scans of 100 children were randomly selected to test backward and forward compatibility of software versions, up to version 15.0 for GE Lunar and Apex 4.1 for Hologic. For the first time, sex- and ethnic-specific reference curves for lumbar spine BMAD, aBMD, and TBLH aBMD are provided for both GE Lunar and Hologic scanners. These curves will facilitate interpretation of DXA data in children using methods recommended in ISCD guidelines. The databases have been created to allow future updates and analysis when more definitive evidence for the best method of fracture prediction in children is agreed. © 2016 American Society for Bone and Mineral Research.

This paper uses recently-released material from the ‘migrated archives’ to provide an original counterinsurgency analysis of the TNKU revolt in Brunei and Sarawak from December 1962 to May 1963. It argues that, despite a failure to act upon intelligence predicting the outbreak of insurgency, Britain developed a highly effective counterinsurgency organisation. These records also indicate that decision-makers drew inspiration from the Malayan Emergency to inform success in Brunei. Although Malaya has been challenged as a counterinsurgency paradigm, the Brunei operations show the utility of striking a balance between inappropriately copying from past campaigns and developing best practices applicable to the unique environment of Borneo. In turn, the evolution of effective operational practices in Brunei informed their successful application to the subsequent Indonesian Confrontation.

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.

This article challenges traditional accounts of the 1946 Cold War Crisis in Iran by moving beyond Soviet–American confrontation to focus on British policy. In contrast to the United States, Britain was a major stake-holding power in Iran due to the valuable holdings of the Anglo–Iranian Oil Company (AIOC). By comparing the reactions of the AIOC and Foreign Office, continuity between the events of the 1946 Crisis and later developments in the Mosaddegh premiership becomes apparent. Soviet interference in Azerbaijan prompted great concern from representatives in Iran, but the central Foreign Office pursued a more cautious policy. Only concerns relating to the growth of domestic Iranian communism in the form of the Tudeh Party and the threat this entailed to the British concession prompted the Foreign Office and AIOC to take measures rendering them partially complicit in the internationalization of Iranian politics, setting an important precedent for future action. This article evaluates the policy-m...

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.

Premature infants are the main recipients of pasteurised donor human milk (PDHM), when their mothers are unable to provide their own. In this study, we evaluated the effect of pasteurisation on the concentrations of vitamin D compounds in donor breastmilk. Milk samples were obtained pre- and post-Holder pasteurisation. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to analyse the samples for vitamins D2 and D3 (D2 and D3) and 25-hydroxyvitamins D2 and D3 (25(OH)D2 and 25(OH)D3). The significance of differences in vitamin D concentrations between the two groups of milk samples was assessed using the Wilcoxon matched-pairs signed rank test, in which p

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.

Milk is an important source of nutrients for various risk populations, including infants. The accurate measurement of vitamin D in milk is necessary to provide adequate supplementation advice for risk groups and to monitor regulatory compliance. Currently used liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods are capable of measuring only four analogues of vitamin D in unfortified milk. We report here an accurate quantitative analytical method for eight analogues of vitamin D: Vitamin D2 and D3 (D2 and D3), 25-hydroxy D2 and D3, 24,25-dihydroxy D2 and D3, and 1,25-dihydroxyD2 and D3. In this study, we compared saponification and protein precipitation for the extraction of vitamin D from milk and found the latter to be more effective. We also optimised the pre-column derivatisation using 4-phenyl-l,2,4-triazoline-3,5-dione (PTAD), to achieve the highest sensitivity and accuracy for all major vitamin D forms in milk. Chromatography was optimised to reduce matrix effects such as ion-suppression, and the matrix effects were eliminated using co-eluting stable isotope labelled internal standards for the calibration of each analogue. The analogues, 25-hydroxyD3 (25(OH)D3) and its epimer (3-epi-25(OH)D3) were chromatographically resolved, to prevent over-estimation of 25(OH)D3. The method was validated and subsequently applied for the measurement of total vitamin D levels in human, cow, mare, goat and sheep milk samples. The detection limits, repeatability standard deviations, and recovery ranges were from 0.2 to 0.4 femtomols, 6.30-13.5%, and 88.2-105%, respectively.

In the UK, vitamin D deficiency in children is recognized as a growing problem. There is a clear need for practice nurses to focus on prevention strategies to reduce the number of children presenting with vitamin D deficiency

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.

Introduction: 5-Fluorouracil is a commonly prescribed antineoplastic drug. Historically, methods to determine this compound in biological fluids have been time consuming or not sensitive enough.

Intravenous pamidronate has been used in the treatment of osteogenesis imperfecta (OI) in children for over 20 years. The more potent zoledronate is an attractive alternative as it is administered less frequently. This study compares the clinical efficacy of intravenous pamidronate (1.5 mg/kg/day over 2 days, every 3 months) versus zoledronate (0.05 mg/kg/dose every 6 months) in 40 children (20 per group) with mild to moderate OI and the treatment costs of the two drugs in a tertiary centre for children with osteoporosis. Lumbar spine bone mineral density and fracture rate did not differ between drug groups following 1 and 2 years of treatment, respectively. Total cost per treatment course per patient was £1157 for pamidronate and £498 for zoledronate. Therefore, zoledronate is a considerably cheaper alternative to pamidronate with comparable efficacy, resulting in substantial annual savings for healthcare providers and a more convenient option for patients due to fewer hospital visits.

Vitamin D is essential for healthy bones and optimizes good health and growth. In the UK, vitamin D deficiency in children is recognized as a growing problem; this is concerning as the condition is preventable. Vitamin D deficiency can cause seizures and cardiomyopathy in infants, rickets in children and muscle weakness at any age. Few foods naturally contain vitamin D; therefore, the main source is sun exposure. During the winter, between the months of October to April, the UK population does not produce adequate vitamin D, owing to the lack of ultraviolet B (UVB) spectrum from sunlight. There is a clear need for health professionals to focus on strategies for prevention to reduce the number of children presenting with vitamin D deficiency. Primary prevention is vital; health professionals should advise safe sun exposure and a dietary intake rich in vitamin D and calcium, and recommend that high-risk groups take a multivitamin supplement containing vitamin D.

Among the high bone mass disorders, the osteopetroses reflect osteoclast failure that prevents skeletal resorption and turnover, leading to reduced bone growth and modeling and characteristic histopathological and radiographic findings. We report an 11-year-old boy with a new syndrome that radiographically mimics osteopetrosis (OPT), but features rapid skeletal turnover. He presented at age 21 months with a parasellar, osteoclast-rich giant cell granuloma. Radiographs showed a dense skull, generalized osteosclerosis and cortical thickening, medullary cavity narrowing, and diminished modeling of tubular bones. His serum alkaline phosphatase was >5000 IU/L (normal

Context: Acid labile subunit (ALS) deficiency, caused by IGFALS mutations, is a subtype of primary IGF-I deficiency (PIGFD) and has been associated with insulin resistance (IR) and osteopenia. Whether patients respond to recombinant human IGF-I (rhIGF-I) is unknown. Objective and Design: This study determined the 14-hour pharmacokinetic response of free and total IGF-I and IGF binding protein 3 (IGFBP-3) to a single sc dose of rhIGF-I (120 μg/kg) in four ALS-deficient patients, compared with severe PIGFD, moderate PIGFD, and controls. Intravenous glucose tolerance tests, fasting blood levels, dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, and metacarpal radiogrammetry were performed in the four patients and 12 heterozygous family members. Results: IGF-I and IGFBP-3 increased above baseline (P < .05) for 2.5 hours, returning to baseline 7 hours after rhIGF-I injection. Mean (SD) IGF-I Z-score increased by 2.49 (0.90), whereas IGFBP-3 Z-score increased by 0.57 (0.10) only. IGF-I elimination rates in ALS deficiency were similar, but the IGF-I increment was lower than those for severe PIGFD. Significant gene dosage effects were found for all IGF-I peptides, height, forearm muscle size, and metacarpal width. Bone analysis showed that ALS deficiency creates a phenotype of slender bones with normal size-corrected density. Abnormal glucose handling and IR was found in three of four patients and 6 of 12 carriers. Conclusions: These gene dosage effects demonstrate that one functional IGFALS allele is insufficient to maintain normal ALS levels, endocrine IGF-I action, full growth potential, muscle size, and periosteal expansion. Similar gene dosage effects may exist for parameters of IR. Despite similar IGF-I elimination compared with severe PIGFD, ALS-deficient patients cannot mount a similar response. Alternative ways of rhIGF-I administration should be sought.

The ability to measure creatinine with good accuracy is essential as its urinary concentration is used to quantify other analytes in urinalysis. In this study, an assay for the determination of creatinine in human urine by hydrophilic interaction liquid chromatography and electrospray ionization tandem mass spectrometry was developed and validated. Hydrophilic interaction chromatography provided retention of creatinine well away from the early eluting impurities that can reduce sensitivity by suppression of the mass spectrometry signal. Ion suppression effects were further eliminated by using a co-eluting, stable-isotope labeled creatinine as the internal standard. The resultant limit of detection was 1.5 picomoles, requiring a sample size of less than 10 µL of urine. The use of tandem mass spectrometry with a stable isotope labeled internal standard provided high specificity, accuracy, and precision for this assay resulting a recovery of 93.9% and a repeatability standard deviation of 3.78%.

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.