bluuebunny/crossref_metadata_2025 huggingface dataset:
Human neural stem cell grafts in the spinal cord of SOD1 transgenic rats: Differentiation and structural integration into the segmental motor circuitry
Authors: Xu Leyan , Ryugo David K. , Pongstaporn Tan , Johe Karl , Koliatsos Vassilis E.
Published: February 2009

Cell replacement strategies for degenerative and traumatic diseases of the nervous system depend on the functional integration of grafted cells into host neural circuitry, a condition necessary for the propagation of physiological signals and, perhaps, targeting of trophic support to injured neurons. We have recently shown that human neural stem cell (NSC) grafts ameliorate motor neuron disease in SOD1 transgenic rodents. Here we study structural aspects of integration of neuronally differentiated human NSCs in the motor circuitry of SOD1 G93A rats. Human NSCs were grafted into the lumbar protuberance of 8‐week‐old SOD1 G93A rats; the results were compared to those on control Sprague‐Dawley rats. Using pre‐embedding immuno‐electron microscopy, we found human synaptophysin (+) terminals contacting the perikarya and proximal dendrites of host α motor neurons. Synaptophysin (+) terminals had well‐formed synaptic vesicles and were associated with membrane specializations primarily in the form of symmetrical synapses. To analyze the anatomy of motor circuits engaging differentiated NSCs, we injected the retrograde transneuronal tracer Bartha‐pseudorabies virus (PRV) or the retrograde marker cholera toxin B (CTB) into the gastrocnemius muscle/sciatic nerve of SOD1 rats before disease onset and also into control rats. With this tracing, NSC‐derived neurons were labeled with PRV but not CTB, a pattern suggesting that PRV entered NSC‐derived neurons via transneuronal transfer from host motor neurons but not via direct transport from the host musculature. Our results indicate an advanced degree of structural integration, via functional synapses, of differentiated human NSCs into the segmental motor circuitry of SOD1‐G93A rats. J. Comp. Neurol. 514:297–309, 2009. © 2009 Wiley‐Liss, Inc.
The GABAergic system in the retina of neonate and adultOctodon degus, studied by immunohistochemistry and electroretinography
Authors: Delgado Luz M. , Vielma Alex H. , Kähne Thilo , Palacios Adrián G. , Schmachtenberg Oliver
Published: February 2009

In the vertebrate retina, gamma‐aminobutyric acid (GABA) mediates inhibitory processes that shape the visual response and is also thought to have neurotrophic functions during retinal development. To investigate the role of GABAergic signaling at the beginning of visual experience, we used immunohistochemistry to compare the distribution of GABA, the two isoforms of glutamic acid decarboxylase GAD65/67, and the GABA receptor types A, B, and C, in neonate versus adultOctodon degus, a native South American rodent with diurnal‐crepuscular activity and a high cone‐to‐rod ratio. In parallel, we used electroretinography to evaluate retinal functionality and to test the contribution of fast GABAergic transmission to light responses at both developmental stages. NeonateO. degusopened their eyes on postnatal day (P)0 and displayed an adult‐like retinal morphology at this time. GABA, its biosynthetic sources, and receptors had a similar cellular distribution in neonates and adults, but labeling of the outer plexiform layer and of certain amacrine and ganglion cells was more conspicuous at P0. In neonates, retinal sensitivity was 10 times lower than in adults, responses to ultraviolet light could not be detected, and oscillatory potentials were reduced or absent. Blockade of GABAA/Creceptors by bicuculline and TPMPA had no noticeable effect in neonates, while it significantly altered the electroretinogram response in adults. Conclusion: In spite of modest differences regarding retinal morphology and GABAergic expression, overall light response properties and GABAergic signaling are undeveloped in neonateO. deguscompared to adults, suggesting that full retinal functionality requires a period of neural refinement under visual experience. J. Comp. Neurol. 514:459–472, 2009. © 2009 Wiley‐Liss, Inc.
Leptin targets in the mouse brain
Authors: Scott Michael M. , Lachey Jennifer L. , Sternson Scott M. , Lee Charlotte E. , Elias Carol F. , Friedman Jeffrey M. , Elmquist Joel K.
Published: February 2009

The central actions of leptin are essential for homeostatic control of adipose tissue mass, glucose metabolism, and many autonomic and neuroendocrine systems. In the brain, leptin acts on numerous different cell types via the long‐form leptin receptor (LepRb) to elicit its effects. The precise identification of leptin's cellular targets is fundamental to understanding the mechanism of its pleiotropic central actions. We have systematically characterized LepRb distribution in the mouse brain using in situ hybridization in wildtype mice as well as by EYFP immunoreactivity in a novel LepRb‐IRES‐Cre EYFP reporter mouse line showing high levels of LepRb mRNA/EYFP coexpression. We found substantial LepRb mRNA and EYFP expression in hypothalamic and extrahypothalamic sites described before, including the dorsomedial nucleus of the hypothalamus, ventral premammillary nucleus, ventral tegmental area, parabrachial nucleus, and the dorsal vagal complex. Expression in insular cortex, lateral septal nucleus, medial preoptic area, rostral linear nucleus, and in the Edinger‐Westphal nucleus was also observed and had been previously unreported. The LepRb‐IRES‐Cre reporter line was used to chemically characterize a population of leptin receptor‐expressing neurons in the midbrain. Tyrosine hydroxylase and Cre reporter were found to be coexpressed in the ventral tegmental area and in other midbrain dopaminergic neurons. Lastly, the LepRb‐IRES‐Cre reporter line was used to map the extent of peripheral leptin sensing by central nervous system (CNS) LepRb neurons. Thus, we provide data supporting the use of the LepRb‐IRES‐Cre line for the assessment of the anatomic and functional characteristics of neurons expressing leptin receptor. J. Comp. Neurol. 514:518–532, 2009. © 2009 Wiley‐Liss, Inc.
Ultrastructure of the subventricular zone in Macaca fascicularis and evidence of a mouse‐like migratory stream
Authors: Gil‐Perotin Sara , Duran‐Moreno María , Belzunegui Silvia , Luquin Maria Rosario , Garcia‐Verdugo Jose Manuel
Published: February 2009

Recent publications have shown that the lateral wall of the lateral ventricles in the Macaca fascicularis brain, in particular the subventricular zone (SVZ), contains neural stem cells throughout adulthood that migrate through a migratory pathway (RMS) to the olfactory bulb (OB). To date, a detailed and systematic cytoarchitectural and ultrastructural study of the monkey SVZ and RMS has not been done. We found that the organization of the SVZ was similar to that of humans, with the ependymal layer surrounding the lateral ventricles, a hypocellular GAP layer formed by astrocytic and ependymal expansions, and the astrocyte ribbon, composed of astrocytic bodies. We found no cells corresponding to the type C proliferating precursor of the rodent brain. Instead, proliferating cells, expressed as Ki‐67 immunoreactivity, were predominantly young neurons concentrated in the anterior regions, and occasional astrocytes of the ribbon. We observed displaced ependymal cells of still unknown significance. New neurons tended to organize in chain‐like structures, which were surrounded by astrocytes. This pattern was highly reminiscent of that observed in rodent RMS, but not in humans. These chains spread from the frontal SVZ along a GAP‐like layer, uniquely composed of astrocytic expansions, to the olfactory bulb (OB). The number of neuronal chains and the number of chain‐forming cells decreased gradually upon reaching the OB. The purpose of this work is to provide a reference for future studies in the field of adult neurogenesis that may lead to an understanding of the fate and functionality of newborn neurons in primates, and ultimately in humans. J. Comp. Neurol. 514:533–554, 2009. © 2009 Wiley‐Liss, Inc.
Combined extrinsic and intrinsic manipulations exert complementary neuronal enrichment in embryonic rat neural precursor cultures: An in vitro and in vivo analysis
Authors: Furmanski Orion , Gajavelli Shyam , Lee Jeung Woon , Collado Maria E. , Jergova Stanislava , Sagen Jacqueline
Published: February 2009

Numerous central nervous system (CNS) disorders share a common pathology in dysregulation of γ‐aminobutyric acid (GABA) inhibitory signaling. Transplantation of GABA‐releasing cells at the site of disinhibition holds promise for alleviating disease symptoms with fewer side effects than traditional drug therapies. We manipulated fibroblast growth factor (FGF)‐2 deprivation and mammalian achaete‐scute homolog (MASH)1 transcription factor levels in an attempt to amplify the default GABAergic neuronal fate in cultured rat embryonic neural precursor cells (NPCs) for use in transplantation studies. Naïve and MASH1 lentivirus‐transduced NPCs were maintained in FGF‐2 or deprived of FGF‐2 for varying lengths of time. Immunostaining and quantitative analysis showed that GABA‐ and β‐III‐tubulin‐immunoreactive cells generally decreased through successive passages, suggesting a loss of neurogenic potential in rat neurospheres expanded in vitro. However, FGF‐2 deprivation resulted in a small, but significantly increased population of GABAergic cells derived from passaged neurospheres. In contrast to naïve and GFP lentivirus‐transduced clones, MASH1 transduction resulted in increased bromodeoxyuridine (BrdU) incorporation and clonal colony size. Western blotting showed that MASH1 overexpression and FGF‐2 deprivation additively increased β‐III‐tubulin and decreased cyclic nucleotide phosphodiesterase (CNPase) expression, whereas FGF‐2 deprivation alone attenuated glial fibrillary acidic protein (GFAP) expression. These results suggest that low FGF‐2 signaling and MASH1 activity can operate in concert to enrich NPC cultures for a GABA neuronal phenotype. When transplanted into the adult rat spinal cord, this combination also yielded GABAergic neurons. These findings indicate that, even for successful utilization of the default GABAergic neuronal precursor fate, a combination of both extrinsic and intrinsic manipulations will likely be necessary to realize the full potential of NSC grafts in restoring function. J. Comp. Neurol. 515:56–71, 2009. © 2009 Wiley‐Liss, Inc.
Embryonic substantia nigra grafts in the mesencephalon send neurites to the host striatum in non‐human primate after overexpression of GDNF
Authors: Redmond D.E. , Elsworth J.D. , Roth R.H. , Leranth C. , Collier T.J. , Blanchard B. , Bjugstad K.B. , Samulski R.J. , Aebischer P. , Sladek J.R.
Published: February 2009

In spite of partial success in treating Parkinson's disease by using ectopically placed grafts of dopamine‐producing cells, restoration of the original neuroanatomical circuits, if possible, might work better. Previous evidence of normal anatomic projections from ventral mesencephalic (VM) grafts placed in the substantia nigra (SN) has been limited to neonatal rodents and double grafting or bridging procedures. This study attempted to determine whether injection of a potent growth‐promoting factor, glial cell line‐derived neurotrophic factor (GDNF), into the target regions or placement of fetal striatal co‐grafts in the nigrostriatal pathway might elicit neuritic outgrowth to the caudate nucleus. Four adult St. Kitts green monkeys received embryonic VM grafts into the rostral mesencephalon near the host SN, and injections of adeno‐associated virus 2 (AAV2)/GDNF or equine infectious anemia virus (EIAV)/GDNF into the caudate. Three adult monkeys were co‐grafted with fetal VM tissue near the SN and fetal striatal grafts (STR) 2.5 mm rostral in the nigrostriatal pathway. Before sacrifice, the striatal target regions were injected with the retrograde tracer Fluoro‐Gold (FG). FG label was found in tyrosine hydroxylase‐labeled neurons in VM grafts in the SN of only those monkeys that received AAV2/GDNF vector injections into the ipsilateral striatum. All monkeys showed FG labeling in the host SN when FG labeling was injected on the same side. These data show that grafted dopaminergic neurons can extend neurites to a distant target releasing an elevated concentration of GDNF, and suggest that grafted neurons can be placed into appropriate loci for potential tract reconstruction. J. Comp. Neurol. 515:31–40, 2009. © 2009 Wiley‐Liss, Inc.
Drosophila DHR38 nuclear receptor is required for adult cuticle integrity at eclosion
Authors: Kozlova Tatiana , Lam Geanette , Thummel Carl S.
Published: February 2009

DHR38 is the only Drosophila member of the NR4A subclass of vertebrate nuclear receptors, which have been implicated in multiple biological pathways, including neuronal function, apoptosis, and metabolism. Although an earlier study identified three point mutations in DHR38, none of these were shown to be a null allele for the locus, leaving it unclear whether a complete loss of DHR38 function might uncover novel roles for the receptor. Here we show that a specific DHR38 null allele, DHR38Y214, leads to fully penetrant pharate adult lethality, similar to the most severe phenotype associated with the EMS‐induced mutations. DHR38Y214 mutants display minor effects on ecdysone‐regulated transcription at the onset of metamorphosis. In contrast, cuticle gene expression is significantly reduced in DHR38Y214 mutant pupae. These studies define the essential functions of DHR38 and provide a genetic context for further characterization of its roles during development. Developmental Dynamics 238:701–707, 2009. © 2009 Wiley‐Liss, Inc.
Presynaptic secretion of mind‐the‐gap organizes the synaptic extracellular matrix‐integrin interface and postsynaptic environments
Authors: Rushton Emma , Rohrbough Jeffrey , Broadie Kendal
Published: February 2009

Mind‐the‐Gap (MTG) is required during synaptogenesis of the Drosophila glutamatergic neuromuscular junction (NMJ) to organize the postsynaptic domain. Here, we generate MTG::GFP transgenic animals to demonstrate MTG is synaptically targeted, secreted, and localized to punctate domains in the synaptic extracellular matrix (ECM). Drosophila NMJs form specialized ECM carbohydrate domains, with carbohydrate moieties and integrin ECM receptors occupying overlapping territories. Presynaptically secreted MTG recruits and reorganizes secreted carbohydrates, and acts to recruit synaptic integrins and ECM glycans. Transgenic MTG::GFP expression rescues hatching, movement, and synaptogenic defects in embryonic‐lethal mtg null mutants. Targeted neuronal MTG expression rescues mutant synaptogenesis defects, and increases rescue of adult viability, supporting an essential neuronal function. These results indicate that presynaptically secreted MTG regulates the ECM‐integrin interface, and drives an inductive mechanism for the functional differentiation of the postsynaptic domain of glutamatergic synapses. We suggest that MTG pioneers a novel protein family involved in ECM‐dependent synaptic differentiation. Developmental Dynamics 238:554–571, 2009. © 2009 Wiley‐Liss, Inc.
Tendons and muscles of the mouse forelimb during embryonic development
Authors: Watson Spences S. , Riordan Timothy J. , Pryce Brian A. , Schweitzer Ronen
Published: February 2009

The range and precision of limb movements are dependent on the specific patterns of muscles and tendons. To facilitate analyses of tendon and muscle phenotypes we compiled a description of these tissues in the forelimb of developing mouse embryos. Individual tendons, muscles, and ligaments were annotated in a series of transverse sections through the forelimb of an embryo at day 18.5 of embryonic development (E18.5). Transverse sections present a distinctive and highly reproducible pattern of the muscles and tendons at different limb levels that can be used as a simple reference in analyses of mutant phenotypes. A comparable set of sections from an embryo at E14.5 was included to highlight structural features that change during the maturation of the musculoskeletal system. The ability to define the precise position of transverse sections along the proximal–distal axis of the limb may also be useful in studies of other features in developing limbs. Developmental Dynamics 238:693–700, 2009. © 2009 Wiley‐Liss, Inc.
FRS2α is required for the separation, migration, and survival of pharyngeal‐endoderm derived organs including thyroid, ultimobranchial body, parathyroid, and thymus
Authors: Kameda Yoko , Ito Masataka , Nishimaki Toshiyuki , Gotoh Noriko
Published: February 2009

The docking protein FRS2α plays an important role in fibroblast growth factor (FGF)‐induced intracellular signal transduction by linking FGF receptors (FGFRs) to a variety of intracellular signaling pathways. In FRS2α2F/2F mutant mice at embryonic day (E)18.5, in which the Shp2‐binding sites of FRS2α were disrupted, the thyroid glands were aplastic or hypoplastic. C cells were absent or present in low numbers and rarely formed a compact mass of cells. Parathyroid glands were mostly connected to thymus tissues. At E10.5, the formations of pharyngeal pouches and thyroid primordium were normally initiated in the mutant mice. At E11.5 to E12.5, the thyroid primordium of wild‐type embryos was located close to the aortic sac, and the epithelial buds of pharyngeal‐derived organs, including the parathyroid gland, thymus and ultimobranchial body, were separated from the epithelium and began to migrate to their final destinations. In the FRS2α2F/2F mutants, however, the thyroid primordium became hypoplastic and the pharyngeal‐derived organ primordia remained affiliated with the pharyngeal epithelium. At these stages, organ‐specific differentiation markers (i.e., Nkx2‐1/TTF1 for the thyroid lobe and ultimobranchial body; Pax8 for the thyroid lobe; parathormone (PTH), chromogranin A, P75NTR, and S100 protein for the parathyroid gland; and p63 for the thymus) were normally expressed in the mutant tissues. Thus, the separation, migration, and survival of the pharyngeal organs were impaired in the FRS2α2F/2F mutants. Developmental Dynamics 238:503–513, 2009. © 2009 Wiley‐Liss, Inc.
The homeobox gene Mohawk represses transcription by recruiting the sin3A/HDAC co‐repressor complex
Authors: Anderson Douglas M. , Beres Brian J. , Wilson‐Rawls Jeanne , Rawls Alan
Published: February 2009

Mohawk is an atypical homeobox gene expressed in embryonic progenitor cells of skeletal muscle, tendon, and cartilage. We demonstrate that Mohawk functions as a transcriptional repressor capable of blocking the myogenic conversion of 10T1/2 fibroblasts. The repressor activity is located in three small, evolutionarily conserved domains (MRD1–3) in the carboxy‐terminal half of the protein. Point mutation analysis revealed six residues in MRD1 are sufficient for repressor function. The carboxy‐terminal half of Mohawk is able to recruit components of the Sin3A/HDAC co‐repressor complex (Sin3A, Hdac1, and Sap18) and a subset of Polymerase II general transcription factors (Tbp, TFIIA1 and TFIIB). Furthermore, Sap18, a protein that bridges the Sin3A/HDAC complex to DNA‐bound transcription factors, is co‐immunoprecipitated by MRD1. These data predict that Mohawk can repress transcription through recruitment of the Sin3A/HDAC co‐repressor complex, and as a result, repress target genes required for the differentiation of cells to the myogenic lineage. Developmental Dynamics 238:572–580, 2009. © 2009 Wiley‐Liss, Inc.
Regulation of the Caenorhabditis elegans posterior hox gene egl‐5 by microRNA and the polycomb‐like gene sop‐2
Authors: Zhang Hongjie , Emmons Scott W.
Published: February 2009

In Caenorhabditis elegans, the domains of Hox gene expression are controlled by the novel global regulatory gene sop‐2. We identified a region located 3′ of the Hox gene egl‐5 that promotes ectopic expression of an egl‐5 reporter gene in a sop‐2 mutant. SOP‐2 could directly block positive regulatory factors acting in this region, or it could block their expression. We identified three possible miRNA binding sites within the egl‐5 3′ untranslated region (UTR). Cognate microRNAs are expressed in relevant tissues and can block egl‐5 expression when expressed from a transgene. Mutation of the putative binding sites in the egl‐5 3′UTR resulted in a modest degree of misexpression of a minimal egl‐5 reporter gene, suggesting that microRNAs may contribute to the tight restriction of egl‐5 expression to particular cell lineages. Developmental Dynamics 238:595–603, 2009. © 2009 Wiley‐Liss, Inc.
Recapitulation of zebrafish sncga expression pattern and labeling the habenular complex in transgenic zebrafish using green fluorescent protein reporter gene
Authors: Chen Yi‐Chung , Cheng Chia‐Hsiung , Chen Gen‐Der , Hung Chin‐Chun , Yang Chung‐Hsiang , Hwang Sheng‐Ping L. , Kawakami Koichi , Wu Bo‐Kai , Huang Chang‐Jen
Published: February 2009

Human synuclein family consists of α‐, β‐, and γ‐synucleins. Here, we cloned three genes, sncb, sncga and sncgb from zebrafish. They encode β‐, γ1‐, and γ2‐synucleins, respectively. The zSyn‐β, zSyn‐γ1, and zSyn‐γ2 proteins display 69%, 47%, and 50% identity to human β‐synuclein and γ‐synuclein, respectively. By reverse transcriptase‐polymerase chain reaction, we demonstrated that sncb and sncga mRNA were abundant in brain and eye, while sncgb expression was moderate in brain, kidney, ovary and testis. The 1.8‐kb 5′‐upstream/promoter region of the sncga gene was sufficient to direct green fluorescent protein (GFP) expression in the central nervous system and cranial ganglions. A transgenic line, Tg(sncga:GFP), was generated and its GFP expression is similar to that of endogenous sncga mRNA. Moreover, this line also labels the habenular complex and the domain of GFP expression is larger in the left than in the right habenula. Thus, this line can be used to study sncga gene regulation and for left–right asymmetry study in zebrafish brain. Developmental Dynamics 238:746–754, 2009. © 2009 Wiley‐Liss, Inc.
Genetic disruption of CYP26B1 severely affects development of neural crest derived head structures, but does not compromise hindbrain patterning
Authors: Maclean Glenn , Dollé Pascal , Petkovich Martin
Published: February 2009

Cyp26b1 encodes a cytochrome‐P450 enzyme that catabolizes retinoic acid (RA), a vitamin A derived signaling molecule. We have examined Cyp26b1−/− mice and report that mutants exhibit numerous abnormalities in cranial neural crest cell derived tissues. At embryonic day (E) 18.5 Cyp26b1−/− animals exhibit a truncated mandible, abnormal tooth buds, reduced ossification of calvaria, and are missing structures of the maxilla and nasal process. Some of these abnormalities may be due to defects in formation of Meckel's cartilage, which is truncated with an unfused distal region at E14.5 in mutant animals. Despite the severe malformations, we did not detect any abnormalities in rhombomere segmentation, or in patterning and migration of anterior hindbrain derived neural crest cells. Abnormal migration of neural crest cells toward the posterior branchial arches was observed, which may underlie defects in larynx and hyoid development. These data suggest different periods of sensitivity of anterior and posterior hindbrain neural crest derivatives to elevated levels of RA in the absence of CYP26B1. Developmental Dynamics 238:732–745, 2009. © 2009 Wiley‐Liss, Inc.
Cardiac cushions modulate action potential phenotype during heart development
Authors: Polo‐Parada Luis , Zhang Xiaolin , Modgi Amol
Published: February 2009

The extracellular matrix plays an important role in cardiac function. Its role in the generation and modulation of electrical activity in the early stages of heart development has not been studied extensively. Our study demonstrates that the extracellular matrix in cardiac cushions can alter the action potential phenotype by direct contact with cardiomyocytes from different regions of the heart. We also demonstrate that fibronectin, an important and abundant component of the cardiac extracellular matrix, partially mimics the effects of the cushion tissue in altering the changes in action potential. Fibronectin increases ICa2+ and acutely increases cytosolic calcium. These findings suggest that the composition of the cardiac extracellular matrix during development plays an important role in defining patterns of electrical activity in the developing heart. Developmental Dynamics 238:611–623, 2009. © 2009 Wiley‐Liss, Inc.
Comprehensive spatiotemporal analysis of early chick neural crest network genes
Authors: Khudyakov Jane , Bronner‐Fraser Marianne
Published: February 2009

Specification of neural crest progenitors begins during gastrulation at the neural plate border, long before migration or differentiation. Neural crest cell fate is acquired by progressive activation of discrete groups of transcription factors that appear to be highly conserved in vertebrates; however, comprehensive analysis of their expression has been lacking in chick, an important model system for neural crest development. To address this, we analyzed expression of 10 transcription factors that are known specifiers of neural plate border and neural crest fate and compared them across developmental stages from gastrulation to neural crest migration. Surprisingly, we find that most neural crest specifiers are expressed during gastrulation in chick, concomitant with and in similar domains as neural plate border specifiers. This finding suggests that interactions between these molecules may occur much earlier than previously thought, an important consideration for interpretation of functional studies. Developmental Dynamics 238:716–723, 2009. © 2009 Wiley‐Liss, Inc.
Fibroblast growth factor expression during skeletal fracture healing in mice
Authors: Schmid Gregory J. , Kobayashi Chikashi , Sandell Linda J. , Ornitz David M.
Published: February 2009

Fibroblast growth factors (FGFs) are important signaling molecules that regulate many stages of endochondral bone development. During the healing of a skeletal fracture, several features of endochondral bone development are reactivated. To better understand the role of FGFs in skeletal fracture healing, we quantitatively evaluated the temporal expression patterns of Fgfs, Fgf receptors (Fgfrs), and molecular markers of bone development over a 14‐day period following long bone fracture in a mouse model. These studies identify distinct groups of FGFs that are differentially expressed and suggest active stage‐specific roles for FGF signaling during the fracture repair process. Developmental Dynamics 238:766–774, 2009. © 2009 Wiley‐Liss, Inc.
Do weight and shape concerns exhibit genetic effects? Investigating discrepant findings
Authors: Spanos Alexia , Burt S. Alexandra , Klump Kelly L.
Published: February 2009

Objective:

Unlike twin studies of general weight and shape concerns, studies examining the heritability of the undue influence of weight and shape concerns on self‐evaluation have found little evidence for genetic effects. The present study sought to resolve these discrepancies by examining the heritability of both types of weight and shape concerns in a young adult twin sample.

Method:

Participants included 270 female twins from the Michigan State University Twin Registry. General weight and shape concerns were assessed with subscales from the Eating Disorder Examination Questionnaire (EDEQ). Similar to previous research, the undue influence of weight and shape on self‐evaluation was assessed using averaged scores from two EDEQ items.

Results:

The heritability of all weight and shape measures was estimated at 49–66%.

Discussion:

General weight and shape concerns and the undue influence of these concerns on self‐evaluation are influenced by genetic factors in young adult female twins. © 2009 by Wiley Periodicals, Inc. Int J Eat Disord 2010
An examination of the overlap between genetic and environmental risk factors for intentional weight loss and overeating
Authors: Wade Tracey D. , Treloar Susan A. , Heath Andrew C. , Martin Nicholas G.
Published: February 2009

Objective:

To further our understanding of how intentional weight loss (IWL) and overeating are related, we examined the shared genetic and environmental variance between lifetime IWL and overeating.

Method:

Interview data were available for 1,976 female twins (both members of 439 and 264 pairs of monozygotic and dizygotic twins, respectively), mean age = 40.61, SD = 4.72. We used lifetime diagnostic data for eating disorders obtained from a semistructured psychiatric telephone interview, examined in a bivariate twin analysis. Both lifetime behaviors were measured on a 3‐point scale, where absence of IWL or overeating formed one anchor on the scale and lifetime anorexia nervosa (AN) and bulimia nervosa (BN) formed the opposite anchors, respectively.

Results:

In line with previous findings, a higher body mass index was significantly associated with the lifetime presence of IWL and/or overeating (odds ratio = 1.13, 95% confidence interval (CI): 1.08–1.19). The best fitting twin model contained additive genetic and nonshared environmental influence influencing both IWL and overeating, with correlations between these influences of 0.61 (95% CI: 0.35–0.92) and 0.24 (95% CI: 0.07–0.42), respectively.

Discussion:

About 37% of genetic risk factors were considered to overlap between IWL and overeating, and with only 6% of overlap between environmental risk factors. Thus, considerable independence of risk factors was indicated. © 2009 by Wiley Periodicals, Inc. Int J Eat Disord 2009
Effects of Concentration of Some Lanthanide(III) Complexes of 1,7‐Bis(carboxymethyl)‐1,4,7,10‐tetraazacyclododecane on Bis(p‐nitrophenyl)phosphate Hydrolysis
Authors: Chang C. Allen , Wu Bo Hong , Hsiao Chih‐Hsiang
Published: February 2009

A detailed study of the effects of the concentration of some lanthanide(III) complexes [LnDO2A+; DO2A = 1,7‐bis(carboxymethyl)‐1,4,7,10‐tetraazacyclododecane] on the hydrolysis of the phosphodiester bond of the compound BNPP [sodium bis(4‐nitrophenyl)phosphate] is reported at 25 °C and pH 7.90 (Ln = Eu), 9.35 (Ln = Eu), and 9.90 (Ln = Eu, Er and Yb). The reaction is found to be first order with respect to BNPP concentration at pH 7.90 and 9.35 and to increase to 1.78 ± 0.09, 1.64 ± 0.07, and 1.63 ± 0.09 with respect to [EuDO2A+] concentration at pH 7.90, 9.35, and 9.90, respectively, thereby indicating that dinuclear species are involved in the reactions. Similar observations were found for the other two LnDO2A+ complexes at pH 9.90 [1.63 ± 0.11 (Er) and 1.49 ± 0.09 (Yb)]. The kobs data obtained by the initial rate method could be fitted to a monomer‐dimer reaction model for all LnDO2A+ complexes at pH 7.90, 9.35, and 9.90 in the [LnDO2A+] concentration range 1.0–20.0 mM. The dinuclear species, namely the mono‐hydroxo‐bridged complexes [Ln2(DO2A)2(μ‐OH)(OH)(H2O)n = 1–3] and the di‐hydroxo‐bridged complexes [Ln2(DO2A)2(μ‐OH)2(H2O)n = 0–2] are found to be more reactive, with reactivities in the order Eu > Yb > Er. The overall formation constants for [Ln2(DO2A)2(μ‐OH)2(H2O)n]‐BNPP are around 104 M–1. The EuDO2A+‐promoted BNPP hydrolysis rates are similar to, or up to two orders of magnitude faster than, most of those reported for other lanthanide and transition‐metal complexes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
A Versatile Synthesis of 5′‐Functionalized Nucleosides Through Regioselective Enzymatic Hydrolysis of Their Peracetylated Precursors
Authors: Bavaro Teodora , Rocchietti Silvia , Ubiali Daniela , Filice Marco , Terreni Marco , Pregnolato Massimo
Published: February 2009

We describe a chemo‐enzymatic synthesis of modified nucleosides through lipase‐catalyzed hydrolysis of their peracetylated precursors. It was found from screening of a large number of substrates that these enzymes' regioselectivities were affected by the sugar and the nucleobase structures. By selecting the best enzyme for each substrate in terms of activity and regioselectivity, we prepared a small library of differently monodeprotected purine and pyrimidine nucleosides useful as intermediates for the synthesis of high‐value nucleosides and mononucleotides. By this approach, the chemo‐enzymatic preparation of doxifluridine (14) anduridine 5′‐monophosphate (5′‐UMP,15) from peracetylated uridine1was carried out. Elimination of many of the processing stages associated with existing methods was achieved, and higher yields and products of increased purity were generated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Fluorescent Switches Based on Photochromic Compounds
Authors: Cusido Janet , Deniz Erhan , Raymo Françisco M.
Published: February 2009

The photochemical transformations associated with photochromic compounds can be exploited to switch the emission of complementary fluorophores under the influence of optical stimulations. Specifically, fluorescent and photochromic components can be integrated within the same molecular or supramolecular assembly and the significant changes in thestereoelectronic properties associated with the photoinduced interconversion of one component can be designed to modulate the emission intensity and/or wavelength of the other. In particular, the modifications in absorption properties, conjugation, dipole moment, redox potentials and shape of a photochrome can all be transduced effectively into reversible alterations of the emissive behavior of a fluorophore. Furthermore, some of these ingenious mechanisms for fluorescence modulation can be extended from relatively small molecular and supramolecular assemblies to large macromolecular, nanostructured and biomolecular constructs. In fact, a diversity of chemical systems with photoswitchable luminescence have already emerged on the basis of these operating principles and choice of functional components. Ultimately, these fundamental studies on the photochemical and photophysical signature of multicomponent assemblies might well lead to a new generation of photonic materials with unique properties for possible applications in biomedical imaging and sensing as well as in information processing and storage.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Domino or Single‐Step Tsuji–Trost/Heck Reactions and Their Application in the Synthesis of 3‐Benzazepines and Azepino[4,5‐b]indole Ring Systems
Authors: Stewart Scott G. , Heath Charles H. , Ghisalberti Emilio L.
Published: February 2009

A series of methods for palladium‐mediated single‐step and domino Tsuji–Trost/Heck reactions are described. These methods are applied to the synthesis of both 3‐benzazepines and azepino[4,5‐b]indoles in the category of complex 6‐7‐6 and 6‐5‐7 ring heterocycles. In addition, a domino Heck/Heck sequence of reactions that produces the azepinobenzindolizine tetracyclic ring system fromN‐diallylated precursors is described. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Screening the Structural Space of Bicyclo‐DNA: Synthesis and Thermal Melting Properties of bc4,3‐DNA (Eur. J. Org. Chem. 8/2009)
Authors: Stauffiger Andrea , Leumann Christian J.
Published: February 2009

The cover picture shows two low‐energy conformations of monomeric units of [4.3.0]bicyclo‐DNA, a conformationally restricted DNA analogue. In an energy‐minimized double helix containing a fully modified strand paired against its complementary DNA, the [4.3.0]bicyclo‐DNA sugar arranges in such a way that O(5′) adopts a pseudoaxial orientation. In the article by A. Stauffiger and C. J. Leumann on p. 1153 ff the synthesis of the modified DNA building block, the X‐ray structure of the monomeric unit as well as thermal melting properties of oligonucleotides are discussed. The authors would like to thank Michael Eggli for his help in designing the cover picture.
Highly Selective and Sensitive Tin(II) Membrane Electrode Based on a New Synthesized Schiff's Base
Authors: Hosseini Morteza , Bagheri Sadeghi Hayedeh , Rahimi Mohammad , Salavati‐Niasari Masoud , Dehghan Abkenar Shiva , Alizadeh Kamal , Reza Ganjali Mohammad
Published: February 2009

Studies on complex formation of tris(3‐(2‐hydroxybenzophenone)propyl)amine (THPA) with a number of metal ions in acetonitrile solution revealed the occurrence of a selective 1 : 1 complexation of the proposed ligand with Sn2+ ion. Consequently, THPA was used as a suitable neutral ionophore for the preparation of a polymeric membrane‐selective electrode. The electrode exhibits a Nernstian behavior with a slope of 29.4±0.3 mV per decade and a detection limit of 2.0×10−7 M. It also showed a good selectivity for Sn2+ ions in comparison with some of group A and B metal ions over a wide concentration range of 5.0×10−7–1.0×10−1 M. Improved selectivity was achieved compared to the best selectivity recently reported by other authors for tin(II). The electrode was successfully applied to the determination of Sn2+ ion in waste water and various canned products.
Fabrication and Characterization of Carbon Nanotube‐Hydroxyapatite Nanocomposite: Application to Anodic Stripping Voltammetric Determination of Cadmium
Authors: Pan Dawei , Wang Yuane , Chen Zhaopeng , Yin Tanji , Qin Wei
Published: February 2009

A novel chemically modified electrode for stripping determination of cadmium is presented in this paper, based on carbon nanotube‐hydroxyapatite (CNT‐HAP) nanocomposite, which can be prepared by an easy and effective one‐step sonication. The newly synthesized nanocomposite was characterized with FTIR, TEM, and electrochemical methods. Due to the combination of the strong absorption ability of HAP and excellent electroanalytical properties of CNTs, the GC/CNT‐HAP electrode has been successfully used for determination of Cd2+ by anodic stripping voltammetry with a linear range of 20 nM–3 μM. The sensitivity and detection limit are 25.6 μA/μM and 4 nM, respectively. The practical application of the proposed electrode has been carried out for the determination of trace levels of Cd2+ in real water samples.
Lead Sensor Using Gold Nanostructured Screen‐Printed Carbon Electrodes as Transducers
Authors: Martínez‐Paredes Graciela , González‐García María Begoña , Costa‐García Agustín
Published: February 2009

Gold nanostructured screen‐printed carbon electrodes are demonstrated to be suitable transducers for the determination of lead using square‐wave voltammetry. Reproducible gold nanostructures have been obtained by direct electrochemical deposition. A calibration plot from 2.5 to 250 μg/L was obtained in acidic solutions of Pb(II) with a reproducibility of 4% (n=10). The detection limit was 0.09 μg/L of lead. The method is then applied to perform a blood lead analysis by adjusting square‐wave parameters in capillary or venous blood with a minimum sample pretreatment and excellent accuracy and reproducibility.
Fe(CN)$\rm{ {_{6}^{4-}}}$‐Doped‐Glutaraldehyde‐Cross‐Linked Poly‐L‐Lysine Film Electrode. Part 1: Electrochemical Characterization and Its Electrocatalytic Activity Towards Oxidation of Ascorbic Acid
Authors: Wu Yu‐Ching , Thangamuthu R. , Chen Shen‐Ming
Published: February 2009

The present work describes preparation, characterization, and electrocatalytic behavior of a hexacyanoferrate‐doped‐glutaraldehyde‐cross‐linked poly‐L‐lysine (PLL‐GA‐Fe(CN)$\rm{ {_{6}^{4-}})}$film modified glassy carbon electrode. The modified electrode has been successfully prepared by electrostatically binding negatively charged Fe(CN)$\rm{ {_{6}^{4-}}}$mediator into cross‐linked poly‐L‐lysine cationic film. The dependence of the peak current of the modified electrode in pure supporting electrolyte (pH 6.8 phosphate buffer solution; PBS) shows that the charge transport in the film is fast and relatively unimpeded at lower scan rates. Cyclic voltammetry and rotating disk electrode (RDE) techniques are used to investigate the electrocatalytic activity of modified electrode towards oxidation of ascorbic acid. The rate constant (k), of catalytic reaction between electrogenerated Fe(CN)$\rm{ {_{6}^{3-}}}$ions and ascorbic acid, obtained from RDE analysis was found to be 5.53×105 cm3mol−1s−1. Finally, the PLL‐GA‐Fe(CN)$\rm{ {_{6}^{4-}}}$film electrodes are successfully used for the individual estimation of ascorbic acid in the concentration range of physiological interest.
Polyaniline Film Based Amperometric pH Sensor Using A Novel Electrochemical Measurement System
Authors: Gao Wei , Song Junfeng
Published: February 2009

A polyaniline based amperometric pH sensor has been developed using a novel electrochemical measurement system. A polyaniline film (PANI) coated pencil graphite electrode (PGE) is connected in series between the working and counter electrodes of a potentiostat, and immersed in the solution together with a reference electrode. When an external potential is applied, the resulting current varies with the solution pH, which provides the basis for the amperoemtric pH sensor. Equations describing the measurement principle are presented. Based on pH dependent emeraldine salt–emeraldine base transition of PANI film, the pH sensor exhibits high stability, accuracy, selectivity, sensitivity and a short time.
Electrodeposition of TiO2 Nanoparticles on Multiwalled Carbon Nanotube Arrays for Hydrogen Peroxide Sensing
Authors: Jiang Liao‐Chuan , Zhang Wei‐De
Published: February 2009

In this work, an amperometric H2O2 sensor based on TiO2/MWCNTs electrode is reported. TiO2 nanoparticles were synthesized on vertically aligned multiwalled carbon nanotube (MWCNT) arrays by electrodeposition. The morphology of the TiO2/MWCNTs was characterized by scanning electron microscopy (SEM). The electrochemical performance of the TiO2/MWCNTs electrode for detection of H2O2 was investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and chronoamperometry. The TiO2/MWCNTs electrode displays high electrocatalytic activity towards oxidation of H2O2 in 0.1 M phosphate buffer solution (PBS, pH 7.4). At an applied potential of +0.40 V, the TiO2/MWCNTs electrode exhibits a linear dependence (R=0.998) in the H2O2 concentration up to 15.0×10−3 M with a sensitivity of 13.4 μA mM−1 and detection limit of 4.0×10−7 M with signal/noise=3. The optimal response time is less than 5 s with addition of 1 mM H2O2. The TiO2/MWCNTs electrode presents stable, high sensitivity and also exhibits fast amperometric response to the detection of H2O2, which is promising for the development of H2O2 sensor.
Determination of Total Phenols in Foods by Boron Doped Diamond Electrode
Authors: Dejmkova Hana , Scampicchio Matteo , Zima Jiri , Barek Jiri , Mannino Saverio
Published: February 2009

A robust electrochemical method to measure the total phenol content in food samples is presented. Under optimal condition, BDD electrode showed excellent performance to detect the oxidation of several phenols and does not present the drawback due to electrode fouling. The analytical method used to perform such measurement has been optimized and successfully applied in different food samples. The results obtained were compared with the standard Folin–Ciocalteau method.
Electrochemical Characterization of Epigallocatechin Gallate Using Square‐Wave Voltammetry
Authors: Novak Ivana , Šeruga Marijan , Komorsky‐Lovrić Šebojka
Published: February 2009

Electrochemical oxidation of (−)‐epigallocatechin gallate (EGCG), the main monomer flavanol found in green tea, has been investigated over a wide pH range at a glassy‐carbon electrode using square‐wave voltammetry (SWV). Square‐wave voltammograms of (−)‐epigallocatechin (EGC) and gallic acid have been studied as well. The I–E profile of EGCG, i.e. the oxidation potentials and the current responses of the first and the second peak, is pH dependent. The oxidation of EGCG is a quasireversible process over the studied pH range, which was also confirmed by the non‐linear relationship between the peak currents and squre root of frequency. The best SWV responses for EGCG were obtained at pH 2.0, frequency of 100 Hz, step of 2 mV and amplitude of 50 mV. Under these conditions, linear responses for EGCG were obtained for concentrations from 1×10−7 M to 1×10−6 M, and calculated LOD and LOQ for the first oxidation peak were 6.59×10−8 M and 2.19×10−7 M, respectively. The proposed electroanalytical procedure was applied for the determination of EGCG content in green tea. Developed SWV methodology represents a potential analytical tool in determination of catechins in tea samples.
Hemoglobin‐Titanate Composite Based Biosensor for the Amperometric Determination of Hydrogen Peroxide in Acidic Medium
Authors: Wu Yihua , Gao Qiuming , Shi Linpu , Gao Lu
Published: February 2009

A hemoglobin‐titanate composite based biosensor was chosen for determination of H2O2 in an acidic medium. CV results of the Hb‐titanate modified pyrolytic graphite electrode showed a pair of well‐defined, quasi‐reversible redox peaks centered at −246 mV (vs. Ag/AgCl) in a pH 5.0 HAc‐NaAc buffer solution. The modified electrode exhibited good electrocatalytic response for monitoring H2O2 and had a large linear detection range from 20 μM to 3.2 mM with a detection limit of 8 μM (S/N=3) and a sensitivity of 29.7 mA M−1 cm−2 in the pH 5.0 solution. The biosensor also possessed good long term storage stability.
A New Indirect Electroanalytical Method to Monitor the Contamination of Natural Waters with 4‐Nitrophenol Using Multiwall Carbon Nanotubes
Authors: Moraes Fernando Cruz , Tanimoto Sonia Tomie , Salazar‐Banda Giancarlo Richard , Machado Sergio Antonio Spinola , Mascaro Lucia Helena
Published: February 2009

The electrochemical detection of the hazardous pollutant 4‐nitrophenol (4‐NP) at low potentials, in order to avoid matrix interferences, is an important research challenge. This study describes the development, electrochemical characterization and utilization of a multiwall carbon nanotube (MWCNT) film electrode for the quantitative determination of 4‐NP in natural water. Electrochemical impedance spectroscopy measurements showed that the modified surface exhibits a decrease of ca. 13 times in the charge transfer resistance when compared with a bare glassy carbon (GC) surface. Voltammetric experiments showed the possibility to oxidize a hydroxylamine layer (produced by the electrochemical reduction of 4‐NP on the GC/MWNCT surface) in a potential region which is approximately 700 mV less positive than that needed to oxidize 4‐NP, thus minimizing the interference of matrix components. The limit of detection for 4‐NP obtained using square‐wave voltammetry (0.12 μmol L−1) was lower than the value advised by EPA. A natural water sample from a dam located in São Carlos (Brazil) was spiked with 4‐NP and analyzed by the standard addition method using the GC/MWCNT electrode, without any further purification step. The recovery procedure yielded a value of 96.5% for such sample, thus confirming the suitability of the developed method to determine 4‐NP in natural water samples. The electrochemical determination was compared with that obtained by HPLC with UV‐vis detection.
Cox processes for estimating temporal variation in disease risk
Authors: Paez Marina Silva , Diggle Peter J.
Published: February 2009

We propose a class of Cox processes as models for the times of occurrence of cases of a disease, and develop associated methods of Bayesian inference for parameter estimation and for prediction of the temporal variation in disease risk. The data may consist of either incidence times of individual cases or counts of the numbers of incident cases in disjoint time‐intervals. We explore the consequences of working with different levels of temporal aggregation of the data. We use a simulated example to demonstrate the feasibility of our methodology, which we then apply to data giving daily counts of incident cases of gastrointestinal infections in the county of Hampshire, UK. Copyright © 2009 John Wiley & Sons, Ltd.