DOCSLIB.ORG

Gitelman Syndrome: Consensus and Guidance from a Kidney

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Gitelman Syndrome: Consensus and Guidance from a Kidney meeting report www.kidney-international.org Gitelman syndrome: consensus and guidance from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference OPEN Anne Blanchard1,2,3,4, Detlef Bockenhauer5,6, Davide Bolignano7, Lorenzo A. Calo` 8, Etienne Cosyns9, Olivier Devuyst10, David H. Ellison11, Fiona E. Karet Frankl12,13, Nine V.A.M. Knoers14, Martin Konrad15, Shih-Hua Lin16,17 and Rosa Vargas-Poussou2,18 1Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris, France; 2Hôpital Européen Georges Pompidou, Assistance Publique Hôpitaux de Paris, Centre d’Investigation Clinique, Paris, France; 3Centre d’Investigation Clinique 1418, Institut National de la Santé et de la Recherche Médicale, Paris, France; 4UMR 970, Institut National de la Santé et de la Recherche Médicale, Paris, France; 5Centre for Nephrology, University College London, London, UK; 6Great Ormond Street Hospital for Children National Health Service Foundation Trust, London, UK; 7Institute of Clinical Physiology, National Research Council, Reggio, Calabria, Italy; 8Department of Medicine, Nephrology, University of Padova, Padova, Italy; 9Wanze, Belgium; 10Institute of Physiology, University of Zurich, Zurich, Switzerland; 11Division of Nephrology and Hypertension, Oregon Health and Science University, Veterans Affairs Portland Health Care System, Portland, Oregon, USA; 12Department of Medical Genetics, University of Cambridge and Cambridge University Hospitals National Health Service Trust, Cambridge, UK; 13Division of Renal Medicine, University of Cambridge and Cambridge University Hospitals National Health Service Trust, Cambridge, UK; 14Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands; 15Department of General Pediatrics, University Children’s Hospital, Münster, Germany; 16Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan; 17Graduate Institute of Medical Science, National Defense Medical Center, Taipei, Taiwan; and 18Centre de Référence des Maladies Rénales Héréditaires de l’Enfant et de l’Adulte, Paris, France Gitelman syndrome (GS) is a rare, salt-losing tubulopathy an initial framework to enable clinical auditing and thus characterized by hypokalemic metabolic alkalosis with improve quality control of care. hypomagnesemia and hypocalciuria. The disease is Kidney International (2017) 91, 24–33; http://dx.doi.org/10.1016/ recessively inherited, caused by inactivating mutations in j.kint.2016.09.046 the SLC12A3 gene that encodes the thiazide-sensitive KEYWORDS: hypokalemic metabolic alkalosis; hypomagnesemia; salt-losing sodium-chloride cotransporter (NCC). GS is usually detected tubulopathy; SLC12A3; thiazide-sensitive sodium-chloride cotransporter during adolescence or adulthood, either fortuitously or in Copyright ª 2016, International Society of Nephrology. Published by association with mild or nonspecific symptoms or both. The Elsevier Inc. This is an open access article under the CC BY-NC-SA license (http://creativecommons.org/licenses/by-nc-sa/4.0/). disease is characterized by high phenotypic variability and a significant reduction in the quality of life, and it may be associated with severe manifestations. GS is usually itelman syndrome (GS), also referred to as familial managed by a liberal salt intake together with oral hypokalemia-hypomagnesemia, is a salt-losing tubul- magnesium and potassium supplements. A general G opathy characterized by hypokalemic metabolic alka- problem in rare diseases is the lack of high quality evidence losis with hypomagnesemia and hypocalciuria.1,2 With a to inform diagnosis, prognosis, and management. We prevalence at w1 to 10 per 40,000, and potentially higher report here on the current state of knowledge related to in Asia,3 GS is arguably the most frequent inherited tubulop- the diagnostic evaluation, follow-up, management, and athy.4 The disease is caused by biallelic inactivating mutations treatment of GS; identify knowledge gaps; and propose a in the SLC12A3 gene encoding the thiazide-sensitive sodium- research agenda to substantiate a number of issues related chloride cotransporter (NCC) expressed in the apical mem- to GS. This expert consensus statement aims to establish brane of cells lining the distal convoluted tubule.5 To date, >350 mutations scattered throughout SLC12A3 have been identified in GS patients.6,7 The majority of patients are com- Correspondence: Olivier Devuyst, Institute of Physiology, University of pound heterozygous for SLC12A3 mutations, but a significant Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland. E-mail: [email protected], or Nine V.A.M. Knoers, Department of Genetics, number of GS patients are found to carry only a single Center for Molecular Medicine, University Medical Center Utrecht, PO Box SLC12A3 mutation. 85090, 3508 AB, Utrecht, the Netherlands. E-mail: [email protected] The presence of both hypocalciuria and hypomagnesemia The authors contributed equally to this report and are listed is highly predictive for the clinical diagnosis of GS, although alphabetically. hypocalciuria is highly variable and hypomagnesemia may be 1,8,9 Received 4 August 2016; revised 14 September 2016; accepted 28 absent. The use of clinical and biological features to September 2016 differentiate from other salt-losing nephropathies is difficult 24 Kidney International (2017) 91, 24–33 A Blanchard et al.: Gitelman syndrome: a KDIGO conference report meeting report in some cases. A GS-like phenotype, including hypomagne- Clinical characteristics and diagnosis semia and hypocalciuria, has also been associated with GS presents mainly in adolescents and adults but can also be mutations in the CLCNKB gene encoding the chloride encountered in children, as early as in the neonatal channel ClC-Kb, the cause of classic Bartter syndrome ([cBS] period.15,18 The key clinical complaints and manifestations or Bartter syndrome type III). The localization of ClC-Kb in suggesting a diagnosis of GS (Table 1) include the following: the distal convoluted tubule explains the phenotypic overlap salt craving (i.e., preference for salty food or a salted treat with GS.10,11 Genetic testing is increasingly available for GS, during childhood); muscle weakness, fatigue, limited sport but it remains expensive. performance or endurance; episodes of fainting, cramps, GS has long been considered a benign tubulopathy, usually tetany, paresthesia, carpopedal spasms; growth retardation, detected during adolescence or adulthood. Indeed, the con- pubertal delay, short stature; thirst or abnormal drinking dition may be asymptomatic or associated with relatively mild behavior; episodes of abdominal pain. Dizziness, vertigo, or nonspecific symptoms or both such as muscular weakness, polyuria, nocturia, palpitations, joint pain, and visual prob- fatigue, salt craving, thirst, nocturia, or cramps. However, this lems may be reported in adults. view has been challenged by reports emphasizing the The proposed biochemical criteria for suspecting a diag- phenotypic variability and potential severity of the disease.12 nosis of GS (Table 2) include the following: documented Cruz et al.13 showed that GS is associated with a significant chronic hypokalemia (<3.5 mmol/l) concomitant with inap- reduction in the quality of life—similar to that associated propriate renal potassium wasting (spot urine, potassium- with congestive heart failure or diabetes. Severe manifesta- creatinine ratio >2.0 mmol/mmol [>18 mmol/g]), in tions, such as early onset (before age 6 years), growth retar- absence of potassium-lowering drugs; metabolic alkalosis; hy- dation, chondrocalcinosis, tetany, rhabdomyolysis, seizures, pomagnesemia (<0.7 mmol/l [<1.70 mg/dl], [Supplementary – and ventricular arrhythmia have been described.13 15 Of note, Table S1]); inappropriate renal magnesium wasting19 (frac- in many reports of severe complications, the diagnosis of GS tional excretion of magnesium >4%);19,20 hypocalciuria (spot was established on clinical rather than genetic grounds, urine, calcium-creatinine ratio <0.2 mmol/mmol [<0.07 potentially creating confusion with related disorders including mg/mg] in adults, [Supplementary Table S1]; normal ranges of cBS. Yet, phenotypic variability has also been documented in calcium-creatinine ratio are different in children, genetically confirmed GS patients, including in patients with [Supplementary Table S2]); high renin (activity or plasma identical SLC12A3 mutations.16 A combination of genotype, levels); fractional excretion of chloride >0.5%; normal or low sex, modifier genes, compensatory mechanisms, as well as blood pressure; normal renal ultrasound with absence of environmental factors or dietary habits might be involved in nephrocalcinosis or renal abnormalities. If plasma electrolyte such variability.17 levels are normal or close to normal in a patient taking GS is usually managed by a liberal salt (NaCl) intake, potassium or magnesium supplements or both, these sup- together with oral magnesium and potassium supplements. plements should be stopped for at least 48 hours in order to Potassium-sparing diuretics, renin angiotensin system potentially unmask the abnormalities. Plasma and urine blockers including angiotensin-converting-enzyme inhibitors samples should be obtained concomitantly. No evidence and angiotensin receptor blockers, and nonsteroidal anti- supports the need for 24-hour urine collection; spot urine inflammatory
Load more

Recommended publications
  • Causes of Short Stature Author Alan D Rogol, MD, Phd Section Editors
    Causes of short stature Author Alan D Rogol, MD, PhD Section Editors Peter J Snyder, MD Mitchell Geffner, MD Deputy Editor Alison G Hoppin, MD Contributor disclosures All topics are updated as new evidence becomes available and our peer review process is complete. Literature review current through: Mar 2016. | This topic last updated: Aug 13, 2015. INTRODUCTION — Short stature is a term applied to a child whose height is 2 standard deviations (SD) or more below the mean for children of that sex and chronologic age (and ideally of the same racial-ethnic group). This corresponds to a height that is below the 2.3rd percentile. Short stature may be either a variant of normal growth or caused by a disease. The most common causes of short stature beyond the first year or two of life are familial (genetic) short stature and delayed (constitutional) growth, which are normal non-pathologic variants of growth. The goal of the evaluation of a child with short stature is to identify the subset of children with pathologic causes (such as Turner syndrome, inflammatory bowel disease or other underlying systemic disease, or growth hormone deficiency). The evaluation also assesses the severity of the short stature and likely growth trajectory, to facilitate decisions about intervention, if appropriate. This topic will review the main causes of short stature. The diagnostic approach to children with short stature is discussed separately. (See "Diagnostic approach to children and adolescents with short stature".) NORMAL VARIANTS OF GROWTH Familial short stature — Familial or genetic short stature is most often a normal variant, termed familial or genetic short stature (figure 1).
    [Show full text]
  • Reframing Psychiatry for Precision Medicine
    Reframing Psychiatry for Precision Medicine Elizabeth B Torres 1,2,3* 1 Rutgers University Department of Psychology; [email protected] 2 Rutgers University Center for Cognitive Science (RUCCS) 3 Rutgers University Computer Science, Center for Biomedicine Imaging and Modelling (CBIM) * Correspondence: [email protected]; Tel.: (011) +858-445-8909 (E.B.T) Supplementary Material Sample Psychological criteria that sidelines sensory motor issues in autism: The ADOS-2 manual [1, 2], under the “Guidelines for Selecting a Module” section states (emphasis added): “Note that the ADOS-2 was developed for and standardized using populations of children and adults without significant sensory and motor impairments. Standardized use of any ADOS-2 module presumes that the individual can walk independently and is free of visual or hearing impairments that could potentially interfere with use of the materials or participation in specific tasks.” Sample Psychiatric criteria from the DSM-5 [3] that does not include sensory-motor issues: A. Persistent deficits in social communication and social interaction across multiple contexts, as manifested by the following, currently or by history (examples are illustrative, not exhaustive, see text): 1. Deficits in social-emotional reciprocity, ranging, for example, from abnormal social approach and failure of normal back-and-forth conversation; to reduced sharing of interests, emotions, or affect; to failure to initiate or respond to social interactions. 2. Deficits in nonverbal communicative behaviors used for social interaction, ranging, for example, from poorly integrated verbal and nonverbal communication; to abnormalities in eye contact and body language or deficits in understanding and use of gestures; to a total lack of facial expressions and nonverbal communication.
    [Show full text]
  • Leading Article the Molecular and Genetic Base of Congenital Transport
    Gut 2000;46:585–587 585 Gut: first published as 10.1136/gut.46.5.585 on 1 May 2000. Downloaded from Leading article The molecular and genetic base of congenital transport defects In the past 10 years, several monogenetic abnormalities Given the size of SGLT1 mRNA (2.3 kb), the gene is large, have been identified in families with congenital intestinal with 15 exons, and the introns range between 3 and 2.2 kb. transport defects. Wright and colleagues12 described the A single base change was identified in the entire coding first, which concerns congenital glucose and galactose region of one child, a finding that was confirmed in the malabsorption. Subsequently, altered genes were identified other aZicted sister. This was a homozygous guanine to in partial or total loss of nutrient absorption, including adenine base change at position 92. The patient’s parents cystinuria, lysinuric protein intolerance, Menkes’ disease were heterozygotes for this mutation. In addition, it was (copper malabsorption), bile salt malabsorption, certain found that the 92 mutation was associated with inhibition forms of lipid malabsorption, and congenital chloride diar- of sugar transport by the protein. Since the first familial rhoea. Altered genes may also result in decreased secretion study, genomic DNA has been screened in 31 symptomatic (for chloride in cystic fibrosis) or increased absorption (for GGM patients in 27 kindred from diVerent parts of the sodium in Liddle’s syndrome or copper in Wilson’s world. In all 33 cases the mutation produced truncated or disease)—for general review see Scriver and colleagues,3 mutant proteins.
    [Show full text]
  • Sarcoidosis, Hypercalcemia and Calcium-Sensing Receptor Mutation: a Case Report
    468 Letters to the Editor Sarcoidosis, Hypercalcemia and Calcium-sensing Receptor Mutation: A Case Report Shreya Dixit1 and Pablo Fernandez-Peñas1,2* 1Skin and Cancer Foundation Australia, 7 Ashley Lane, Westmead, NSW 2145, and 2Sydney Medical School Western, The University of Sydney, NSW, Australia. *E-mail: [email protected] Accepted October 28, 2010. Sarcoidosis is a multisystem granulomatous disease of The incidence of hypercalcaemia in patients with unknown aetiology. It predominantly affects the lungs; sarcoidosis is approximately 10% (3). It has previously however, 25% of patients have skin involvement, ranging been found that these abnormalities of calcium metabo- from non-specific maculopapular eruptions to erythema lism are due to dysregulated production of calcitriol by nodosum and lupus pernio (1). activated macrophages trapped in pulmonary alveoli and Familial hypocalciuric hypercalcaemia (FHH) results granulomatous inflammation (4). Conversion of calcidiol from an autosomal dominantly inherited inactivating to calcitriol is facilitated by 1 alpha-hydroxylase, a cyto- mutation of the calcium-sensing receptor (CaSR) gene chrome P450 enzyme. The activity of 1 alpha-hydroxyla- and is typically asymptomatic (2). Sarcoidosis has not se is tightly regulated through complex mechanisms that previously been reported in FHH. We had the opportu- depend on the circulating levels of calcium, phosphorus, nity to study a patient with sarcoidosis that has a CaSR PTH, 1,25 (OH)2D3 (calcitriol) and calcitonin. The role mutation. of CaSR in the regulation of 1 alpha-hydroxylase has not been defined, although there are suggestions that CaSR activation can repress the enzyme (5). CASE REPORT The incidence of FHH in patients with sarcoidosis A 70-year-old woman was referred by her endocrinologist with is unknown.
    [Show full text]
  • Phytoplankton As Key Mediators of the Biological Carbon Pump: Their Responses to a Changing Climate
    sustainability Review Phytoplankton as Key Mediators of the Biological Carbon Pump: Their Responses to a Changing Climate Samarpita Basu * ID and Katherine R. M. Mackey Earth System Science, University of California Irvine, Irvine, CA 92697, USA; [email protected] * Correspondence: [email protected] Received: 7 January 2018; Accepted: 12 March 2018; Published: 19 March 2018 Abstract: The world’s oceans are a major sink for atmospheric carbon dioxide (CO2). The biological carbon pump plays a vital role in the net transfer of CO2 from the atmosphere to the oceans and then to the sediments, subsequently maintaining atmospheric CO2 at significantly lower levels than would be the case if it did not exist. The efficiency of the biological pump is a function of phytoplankton physiology and community structure, which are in turn governed by the physical and chemical conditions of the ocean. However, only a few studies have focused on the importance of phytoplankton community structure to the biological pump. Because global change is expected to influence carbon and nutrient availability, temperature and light (via stratification), an improved understanding of how phytoplankton community size structure will respond in the future is required to gain insight into the biological pump and the ability of the ocean to act as a long-term sink for atmospheric CO2. This review article aims to explore the potential impacts of predicted changes in global temperature and the carbonate system on phytoplankton cell size, species and elemental composition, so as to shed light on the ability of the biological pump to sequester carbon in the future ocean.
    [Show full text]
  • Turner Syndrome (TS) Is a Genetic Disease That Affects About Physical Signs of TS May Include: 1 in Every 2,500 Female Live Births
    Notes: A Guide for Caregivers For easily accessible answers, education, and support, visit Nutropin.com or call 1-866-NUTROPIN (1-866-688-7674). 18 19 of patients with Your healthcare team is your primary source Turner Syndrome of information about your child’s treatment. Please see the accompanying full Prescribing Information, including Instructions for Use, and additional Important Safety Information througout and on pages 16-18. Models used for illustrative purposes only. Nutropin, Nutropin AQ, and NuSpin are registered trademarks, Nutropin GPS is a trademark, and NuAccess is a service mark of Genentech, Inc. © 2020 Genentech USA, Inc., 1 DNA Way, So. San Francisco, CA 94080 M-US-00005837(v1.0) 06/20 FPO Understanding Turner Syndrome What is Turner Syndrome? Turner Syndrome (TS) is a genetic disease that affects about Physical signs of TS may include: 1 in every 2,500 female live births. TS occurs when one • Short stature of a girl’s two X chromosomes is absent or incomplete. • Webbing of the neck Chromosomes are found in all cells of the human body. They contain the genes that determine the characteristics of a • Low-set, rotated ears person such as the color of hair or eyes. Every person has • Arms that turn out slightly at the elbows 22 pairs of chromosomes containing these characteristics, • Low hairline at the back of the head and one pair of sex chromosomes. • A high, arched palate in the mouth Normally cells in a female’s body contain two “X” chromosomes Biological signs of TS may include: (Fig. 1). • Underdevelopment of the ovaries In girls with TS, part or • Not reaching sexual maturity or starting all of one X chromosome a menstrual period (Fig.
    [Show full text]
  • Reduced Calcification of Marine Plankton in Response to Increased
    letters to nature Acknowledgements representatives of the coccolithophorids, Emiliania huxleyi and This research was sponsored by the EPSRC. T.W.F. ®rst suggested the electrochemical Gephyrocapsa oceanica, are both bloom-forming and have a deoxidation of titanium metal. G.Z.C. was the ®rst to observe that it was possible to reduce world-wide distribution. G. oceanica is the dominant coccolitho- thick layers of oxide on titanium metal using molten salt electrochemistry. D.J.F. suggested phorid in neritic environments of tropical waters9, whereas the experiment, which was carried out by G.Z.C., on the reduction of the solid titanium dioxide pellets. M. S. P. Shaffer took the original SEM image of Fig. 4a. E. huxleyi, one of the most prominent producers of calcium carbonate in the world ocean10, forms extensive blooms covering Correspondence and requests for materials should be addressed to D. J. F. large areas in temperate and subpolar latitudes9,11. (e-mail: [email protected]). The response of these two species to CO2-related changes in seawater carbonate chemistry was examined under controlled ................................................................. pH Reduced calci®cation 8.4 8.2 8.1 8.0 7.9 7.8 PCO2 (p.p.m.v.) of marine plankton in response 200 400 600 800 a 10 to increased atmospheric CO2 ) 8 –1 Ulf Riebesell *, Ingrid Zondervan*, BjoÈrn Rost*, Philippe D. Tortell², d –1 Richard E. Zeebe*³ & FrancËois M. M. Morel² 6 * Alfred Wegener Institute for Polar and Marine Research, P.O. Box 120161, 4 D-27515 Bremerhaven, Germany mol C cell –13 ² Department of Geosciences & Department of Ecology and Evolutionary Biology, POC production Princeton University, Princeton, New Jersey 08544, USA (10 2 ³ Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA 0 .............................................................................................................................................
    [Show full text]
  • Current Dosing of Growth Hormone in Children with Growth Hormone Deficiency: How Physiologic?
    Current Dosing of Growth Hormone in Children With Growth Hormone Deficiency: How Physiologic? Margaret H. MacGillivray, MD*; Sandra L. Blethen, MD, PhD‡; John G. Buchlis, MD*; Richard R. Clopper, ScD*; David E. Sandberg, PhD*; and Thomas A. Conboy, MS* ABSTRACT. The current doses of recombinant growth ARE THE APPROVED RECOMBINANT HUMAN GH hormone (rGH) are two to three times those used in the DOSING REGIMENS PHYSIOLOGIC? pituitary growth hormone era. These rGH doses (0.025 to A standard method for determining whether hor- 0.043 mg/kg/d) are similar to or moderately greater than mone replacement is physiologic is to compare the the physiologic requirements. Growth velocity and dose of hormone administered with the amount of height gains have been shown to be greater with 0.05 that hormone produced daily in healthy persons. For mg/kg/d of rGH than with 0.025 mg/kg/d. Larger doses of human GH, this is not an easy task because of its GH and early initiation of treatment result in greater short half-life, multicompartmental distribution, and heights at the onset of puberty and greater adult heights. Earlier onset of puberty and more rapid maturation, as episodic pulsatile pattern of secretion. In addition, indicated by bone age, were not observed in children GH has a variable secretion profile that is influenced who were given 0.18 to 0.3 mg/kg/wk of rGH. The fre- by age, diurnal rhythm, sleep, stress, nutrition, body quency of adverse events is very low, but diligent sur- weight, and sex hormones. One approach to calcu- veillance of all children who are treated with rGH is lating daily levels of endogenously produced GH essential.
    [Show full text]
  • Inherited Renal Tubulopathies—Challenges and Controversies
    G C A T T A C G G C A T genes Review Inherited Renal Tubulopathies—Challenges and Controversies Daniela Iancu 1,* and Emma Ashton 2 1 UCL-Centre for Nephrology, Royal Free Campus, University College London, Rowland Hill Street, London NW3 2PF, UK 2 Rare & Inherited Disease Laboratory, London North Genomic Laboratory Hub, Great Ormond Street Hospital for Children National Health Service Foundation Trust, Levels 4-6 Barclay House 37, Queen Square, London WC1N 3BH, UK; [email protected] * Correspondence: [email protected]; Tel.: +44-2381204172; Fax: +44-020-74726476 Received: 11 February 2020; Accepted: 29 February 2020; Published: 5 March 2020 Abstract: Electrolyte homeostasis is maintained by the kidney through a complex transport function mostly performed by specialized proteins distributed along the renal tubules. Pathogenic variants in the genes encoding these proteins impair this function and have consequences on the whole organism. Establishing a genetic diagnosis in patients with renal tubular dysfunction is a challenging task given the genetic and phenotypic heterogeneity, functional characteristics of the genes involved and the number of yet unknown causes. Part of these difficulties can be overcome by gathering large patient cohorts and applying high-throughput sequencing techniques combined with experimental work to prove functional impact. This approach has led to the identification of a number of genes but also generated controversies about proper interpretation of variants. In this article, we will highlight these challenges and controversies. Keywords: inherited tubulopathies; next generation sequencing; genetic heterogeneity; variant classification. 1. Introduction Mutations in genes that encode transporter proteins in the renal tubule alter kidney capacity to maintain homeostasis and cause diseases recognized under the generic name of inherited tubulopathies.
    [Show full text]
  • Distribution of Calcium Phosphate in the Exoskeleton of Larval Exeretonevra Angustifrons Hardy (Diptera: Xylophagidae)
    Arthropod Structure & Development 34 (2005) 41–48 www.elsevier.com/locate/asd Distribution of calcium phosphate in the exoskeleton of larval Exeretonevra angustifrons Hardy (Diptera: Xylophagidae) Bronwen W. Cribba,b,*, Ron Rascha, John Barrya, Christopher M. Palmerb,1 aCentre for Microscopy and Microanalysis, The University of Queensland, Brisbane, Qd 4072, Australia bDepartment of Zoology and Entomology, The University of Queensland, Brisbane, Qd 4072, Australia Received 28 July 2004; accepted 26 August 2004 Abstract Distribution and organisation of the mineral, amorphous calcium phosphate (ACP), has been investigated in the exoskeleton of the xylophagid fly larva Exeretonevra angustifrons Hardy. While head capsule and anal plate are smooth with a thin epicuticle, the epicuticle of the body is thicker and shows unusual micro-architecture comprised of minute hemispherical (dome-shaped) protrusions. Electron microprobe analysis and energy dispersive spectroscopy revealed heterogeneity of mineral elements across body cuticle and a concentration of ACP in the epicuticle, especially associated with the hemispherical structures. Further imaging and analysis showed the bulk of the ACP to be present in nano-sized granules. It is hypothesised that the specific distribution of ACP may enhance cuticular hardness or durability without reducing flexibility. q 2004 Elsevier Ltd. All rights reserved. Keywords: Insect; Cuticle; Integument; Hardening; Analytical electron microscopy; Electron microprobe 1. Introduction was distributed heterogeneously. Further investigation of the distribution of the mineral phase at the micron and Strengthening of biological structures through cuticular nanometre level is needed to discover where deposition is calcification is well developed in decapod crustaceans but it occurring and how this might affect exoskeletal organis- rarely occurs in insects, where it is poorly understood ation.
    [Show full text]
  • Obese Children and Adolescents: a Risk Group for Low Vitamin B12
    ARTICLE Obese Children and Adolescents A Risk Group for Low Vitamin B12 Concentration Orit Pinhas-Hamiel, MD; Noa Doron-Panush, RD; Brian Reichman, MD; Dorit Nitzan-Kaluski, MD, MPH, RD; Shlomit Shalitin, MD; Liat Geva-Lerner, MD Objective: To assess whether overweight children and Results: Median concentration of serum B12 in normal- adolescents are at an increased risk for vitamin B12 deficiency. weight children was 530 pg/mL and in obese children, Ͻ 400 pg/mL (P .001). Low B12 concentrations were noted Design: Prospective descriptive study. in 10.4% of the obese children compared with only 2.2% Ͻ of the normal weight group (P .001). Vitamin B12 defi- Setting: Two pediatric endocrine centers in Israel. ciency was noted in 12 children, 8 (4.9%) of the obese subjects and 4 (1.8%) of the normal weight group (P=.08). Participants: Three hundred ninety-two children and After we adjusted for age and sex, obesity was associ- adolescents were divided into 2 groups as follows: the ated with a 4.3-fold risk for low serum B12, and each unit normal-weight group had body mass indexes, calcu- increase in body mass index standard deviation score re- lated as weight in kilograms divided by height in meters sulted in an increased risk of 1.24 (95% confidence in- squared, under the 95th percentile (Ͻ1.645 standard de- terval, 0.99-1.56). viation scores; n=228); the obese group had body mass indexes equal to or above the 95th percentile (Ն1.645 standard deviation scores; n=164). Conclusions: Obesity in children and adolescents was associated with an increased risk of low vitamin B12 con- Intervention: We measured vitamin B12 concentra- centration.
    [Show full text]
  • Table of Contents (PDF)
    CJASNClinical Journal of the American Society of Nephrology March 2012 c Vol. 7 c No. 3 Editorials 373 Adding to the Armamentarium: Antibiotic Dosing in Extended Dialysis Bruce A. Mueller and Bridget A. Scoville See related article on page 385. 376 Albuminuria and Cognitive Impairment Linda Fried See related article on page 437. 379 Adaptation in Gitelman Syndrome: “We Just Want to Pump You Up” David H. Ellison See related article on page 472. 383 Are Maintenance Corticosteroids No Longer Necessary after Kidney Transplantation? Joshua J. Augustine and Donald E. Hricik See related article on page 494. Original Articles Acute Kidney Injury /Acute Renal Failure 385 Pharmacokinetics of Ampicillin/Sulbactam in Critically Ill Patients with Acute Kidney Injury undergoing Extended Dialysis Johan M. Lorenzen, Michael Broll, Volkhard Kaever, Heike Burhenne, Carsten Hafer, Christian Clajus, Wolfgang Knitsch, Olaf Burkhardt, and Jan T. Kielstein See related editorial on page 373. Chronic Kidney Disease 391 Efficacy and Safety of Paricalcitol Therapy for Chronic Kidney Disease: A Meta-Analysis Jun Cheng, Wen Zhang, Xiaohui Zhang, Xiayu Li, and Jianghua Chen 401 Predictors of Estimated GFR Decline in Patients with Type 2 Diabetes and Preserved Kidney Function Giacomo Zoppini, Giovanni Targher, Michel Chonchol, Vittorio Ortalda, Carlo Negri, Vincenzo Stoico, and Enzo Bonora 409 Risks of Subsequent Hospitalization and Death in Patients with Kidney Disease Kenn B. Daratha, Robert A. Short, Cynthia F. Corbett, Michael E. Ring, Radica Alicic, Randall Choka, and Katherine R. Tuttle Clinical Immunology and Pathology 417 Factor I Autoantibodies in Patients with Atypical Hemolytic Uremic Syndrome: Disease-Associated or an Epiphenomenon? David Kavanagh, Isabel Y.
    [Show full text]