bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some new psychoactive substances: Precursor chemicals and synthesis‐driven end‐products
Authors: Collins Michael 
Published: July 2011

AbstractThis paper describes some of the new classes of ‘designer drugs’ being encountered today by forensic scientists and law enforcement agencies in Europe, the United States, and Australia. In particular, it concentrates on new cathinone derivatives, the tryptamines, new‐generation phenethylamines, and some of the synthetic cannabinoids. The synthetic approaches towards many of these designer drugs including a discussion of the chemical precursors used in the syntheses are presented. Many of today's so‐called designer drugs exist as a result of legitimate research into medical conditions and the natural product chemistry. A link between synthetic approaches published in the open scientific and medical literature and the exploitation of this research by clandestine manufacture of drugs for illicit purposes is drawn. Copyright © 2011 John Wiley & Sons, Ltd.
Developmental expression of the fermitin/kindlin gene family in Xenopus laevis embryos
Authors: Canning Claire A. , Chan Jessica Sze Ki , Common John E. A. , Lane E. Birgitte , Jones C. Michael 
Published: July 2011

AbstractFermitin genes are highly conserved and encode cytocortex proteins that mediate integrin signalling. Fermitin 1 (Kindlin1) is implicated in Kindler syndrome, a human skin blistering disorder. We report the isolation of the three Fermitin orthologs from Xenopus laevis embryos and describe their developmental expression patterns. Fermitin 1 is expressed in the skin, otic and olfactory placodes, pharyngeal arches, pronephric duct, and heart. Fermitin 2 is restricted to the somites and neural crest. Fermitin 3 is expressed in the notochord, central nervous system, cement gland, ventral blood islands, vitelline veins, and myeloid cells. Our findings are consistent with the view that Fermitin 1 is generally expressed in the skin, Fermitin 2 in muscle, and Fermitin 3 in hematopoietic lineages. Moreover, we describe novel sites of Fermitin gene expression that extend our knowledge of this family. Our data provide a basis for further functional analysis of the Fermitin family in Xenopus laevis. Developmental Dynamics 240:1958–1963, 2011. © 2011 Wiley‐Liss, Inc.
Cell biological regulation of division fate in vertebrate neuroepithelial cells
Authors: Willardsen Minde I. , Link Brian A. 
Published: July 2011

AbstractThe developing nervous system derives from neuroepithelial progenitor cells that divide to generate all of the mature neuronal types. For the proper complement of cell types to form, the progenitors must produce postmitotic cells, yet also replenish the progenitor pool. Progenitor divisions can be classified into three general types: symmetric proliferative (producing two progenitors), asymmetric neurogenic (producing one progenitor and one postmitotic cell), and symmetric neurogenic (producing two postmitotic cells). The appropriate ratios for these modes of cell division require intrinsic polarity, which is one of the characteristics that define neuroepithelial progenitor cells. The type of division an individual progenitor undergoes can be influenced by cellular features, or behaviors, which are heterogeneous within the population of progenitors. Here we review three key cellular parameters, asymmetric inheritance, cell cycle kinetics, and interkinetic nuclear migration, and the possible mechanisms for how these features influence progenitor fates. Developmental Dynamics 240:1865–1879, 2011. © 2011 Wiley‐Liss, Inc.
V‐ATPase‐dependent ectodermal voltage and ph regionalization are required for craniofacial morphogenesis
Authors: Vandenberg Laura N. , Morrie Ryan D. , Adams Dany Spencer 
Published: July 2011

AbstractUsing voltage and pH reporter dyes, we have discovered a never‐before‐seen regionalization of the Xenopus ectoderm, with cell subpopulations delimited by different membrane voltage and pH. We distinguished three courses of bioelectrical activity. Course I is a wave of hyperpolarization that travels across the gastrula. Course II comprises the appearance of patterns that match shape changes and gene expression domains of the developing face; hyperpolarization marks folding epithelium and both hyperpolarized and depolarized regions overlap domains of head patterning genes. In Course III, localized regions of hyperpolarization form at various positions, expand, and disappear. Inhibiting H+‐transport by the H+‐V‐ATPase causes abnormalities in: (1) the morphology of craniofacial structures; (2) Course II voltage patterns; and (3) patterns of sox9, pax8, slug, mitf, xfz3, otx2, and pax6. We conclude that this bioelectric signal has a role in development of the face. Thus, it exemplifies an important, under‐studied mechanism of developmental regulation. Developmental Dynamics 240:1889–1904, 2011. © 2011 Wiley‐Liss, Inc.
Analysis of Cdh22 expression and function in the developing mouse brain
Authors: Saarimäki‐Vire Jonna , Alitalo Annamari , Partanen Juha 
Published: July 2011

AbstractClassical cadherins are important cell adhesion molecules specifying and separating brain nuclei and developmental compartments.Cadherin‐22(Cdh22) belongs to type II subfamily of classical cadherins, and is expressed at the midbrain‐hindbrain boundary during early embryogenesis. InFgfr1mutant mouse embryos, which have a disturbed midbrain‐hindbrain border,Cdh22is down‐regulated. Here, we studied expression ofCdh22in developing mouse brain in more detail and compared it to expression of related family members. This revealed both complementary and overlapping patterns ofCdh22, Cdh11, Cdh8, andCdh6expression in distinct regions of the forebrain and midbrain. We used a mutated allele ofCdh22to study its function in brain development. Loss of Cdh22 caused reduced postnatal viability. Despite strongCdh22expression in the developing brain, we did not observe defects in compartmentalization or abnormalities in the midbrain and forebrain nuclei inCdh22mutants. This may be explained by functional redundancy between type II cadherins. Developmental Dynamics 240:1989–2001, 2011. © 2011 Wiley‐Liss, Inc.
Planar cell movements and oriented cell division during early primitive streak formation in the mammalian embryo
Authors: Halacheva Viktoriya , Fuchs Mathias , Dönitz Jürgen , Reupke Tobias , Püschel Bernd , Viebahn Christoph 
Published: July 2011

AbstractFormation of the mammalian primitive streak appears to rely on cell proliferation to a minor extent only, but compensating cell movements have not yet been directly observed. This study analyses individual cell migration and proliferation simultaneously, using multiphoton and differential interference contrast time‐lapse microscopy of late pregastrulation rabbit blastocysts. Epiblast cells in the posterior gastrula extension area accumulated medially and displayed complex planar movements including U‐turns and a novel type of processional cell movement. In the same area metaphase plates tended to be aligned parallel to the anterior–posterior axis, and statistical analysis showed that rotations of metaphase plates causing preferred orientation were near‐complete 8 min before anaphase onset; in some cases, rotations were strikingly rapid, achieving up to 45° per min. The mammalian primitive streak appears to be formed initially with its typically minimal anteroposterior elongation by a combination of oriented cell divisions with dedicated planar cell movements. Developmental Dynamics 240:1905–1916, 2011. © 2011 Wiley‐Liss, Inc.
Primer and interviews: Promises and realities of induced pluripotent stem cells
Authors: Kiefer Julie C. 
Published: July 2011

AbstractIn 2006, Yamanaka's group announced they had discovered the proverbial “fountain of youth” for human cells, forever changing the field of stem cell research. After misexpressing within them a cocktail of four genes, adult somatic cells revert into an embryonic stem cell (ESC)‐like state. These so‐called induced pluripotent stem cells (iPSCs) can differentiate into a wide variety of cell types, seemingly bypassing the need for politically charged ESCs. However, iPSCs differ from ESCs in potentially deleterious ways, precluding their use in regenerative medicine. In this primer and adjoining discussion with iPSC biologists William Lowry, PhD, and Clive Svendsen, PhD, we explore these issues as well how iPSCs promise to contribute to the understanding of developmental biology and the etiology, and treatment, of human diseases. Developmental Dynamics 240:2034–2041, 2011. © 2011 Wiley‐Liss, Inc.
Zebrafish nephrogenesis involves dynamic spatiotemporal expression changes in renal progenitors and essential signals from retinoic acid and irx3b
Authors: Wingert Rebecca A. , Davidson Alan J. 
Published: July 2011

AbstractKidney nephrons are composed of proximal and distal tubule segments that perform unique roles in excretion. The developmental pathways that establish nephron segment identities from renal progenitors are poorly understood. Here, we used the zebrafish pronephros to study nephron segmentation. We found that zebrafish nephron progenitors undergo elaborate spatiotemporal expression changes of many genes before adopting a segment fate. Initially, two domains of nephron progenitors are established, then are subdivided and demarcate individual nephron segments. Using genetic and chemical genetic models of retinoic acid (RA) deficiency, we discovered that RA modulates rostral progenitor formation. To delineate downstream pathways, we knocked down the irx3b transcription factor and found it regulates proximal tubule segment size and distal segment differentiation. Our results suggest a model whereby RA patterns the early field of nephron progenitors, with subsequent factors like irx3b acting to refine later progenitor subdomains and ensure activation of segment‐specific gene programs. Developmental Dynamics 240:2011–2027, 2011. © 2011 Wiley‐Liss, Inc.
Quantitative three‐dimensional imaging of live avian embryonic morphogenesis via micro‐computed tomography
Authors: Henning Alyssa L. , Jiang Michael X. , Yalcin Huseyin C. , Butcher Jonathan T. 
Published: July 2011

AbstractMany clinically relevant congenital malformations arise during mid to late embryonic stages. This period is challenging to image quantitatively in live embryos, necessitating the use of multiple specimens with increased experimental variability. Here we establish X‐ray and blood‐pool computed tomography (CT) contrast agent toxicity and teratogenesis thresholds for 3D Micro‐CT imaging of live avian embryos. Day 4 chick embryos micro‐injected with Visipaque™ (VP) developed for an additional 6 days without defect. X‐ray radiation up to 798 mGy was nontoxic. Peak average contrast of 1,060 HU occurred within 1 hr of imaging at 50 μm resolution. VP‐enhanced contrast persisted past 24 hr with delayed accumulation in the allantois. Regional volumes of VP‐injected embryos were statistically identical to those of fixed embryos perfused with osmium tetroxide. We further quantified longitudinal volumetric morphogenesis of the allantois over 30 hr. These results demonstrate the safety and efficacy of contrast enhanced quantitative micro‐CT imaging for live embryos. Developmental Dynamics 240:1949–1957, 2011. © 2011 Wiley‐Liss, Inc.
A transgenic zebrafish model of targeted oocyte ablation and de novo oogenesis
Authors: White Yvonne A. R. , Woods Dori C. , Wood Antony W. 
Published: July 2011

AbstractWe describe here a novel transgenic zebrafish, Tg(zpc:G4VP16/UAS:nfsB‐mCherry) that effectively demonstrates the targeted oocyte ablation in the adult zebrafish ovary. This transgenic line expresses bacterial nitroreductase enzyme (nfsB) under the control of the oocyte‐specific zona pellucida C (zpc) gene promoter. Adult transgenic females exposed to the prodrug metronidazole demonstrated near‐complete ablation of growing oocytes, resulting in ovarian degeneration and complete cessation of reproductive function. Within 4 weeks of prodrug removal, treated fish demonstrated complete anatomical regeneration of the ovary and, within 7 weeks, ovarian function (fertility) was fully restored. Together, these results demonstrate functional renewal of the oocyte pool in the adult zebrafish ovary. Accordingly, this transgenic zebrafish model system provides a novel means to investigate ovarian growth dynamics in a genetically tractable vertebrate, and may be useful for evaluating signaling interactions that regulate gonadal development processes such as de novo oogenesis. Developmental Dynamics 240:1929–1937, 2011. © 2011 Wiley‐Liss, Inc.
Expression of metanephric nephron‐patterning genes in differentiating mesonephric tubules
Authors: Georgas K.M. , Chiu H.S. , Lesieur E. , Rumballe B.A. , Little Melissa H. 
Published: July 2011

AbstractSchematic illustrating the murine urogenital tract at 13.5 dpc. The early tubules of the metanephros (kidney) and mesonephric tubules of the mesonephros are highlighted in blue. Below are examples of gene expression in the early tubules of the kidney (Lhx1, centre) and in the mesonephric tubules of the male mesonephroi (Gpd1) detected using wholemount in situ hybridization. From Georgas et al., Developmental Dynamics 240:1600–1612, 2011.
DNA Cleavage by Structurally Characterized Dinuclear Copper(II) Complexes Based on Triazine
Authors: Massoud Salah S. , Louka Febee R. , Xu Wu , Perkins Richard S. , Vicente Ramon , Albering Jörg H. , Mautner Franz A. 
Published: July 2011

AbstractThe reaction of 2‐chloro‐4,6‐bis(di‐2‐picolylamino)‐1,3,5‐triazine (bdpaTCl) with copper(II) perchlorate and copper(II) chloride afforded two dinuclear complexes [Cu2(μ‐bdpaTCl)(μ‐OH)2(H2O)0.5(ClO4)0.5](ClO4)1.5·(H2O)1.5 (1) and [Cu2(μ‐bdpaTCl)Cl4]·2CH3OH (2), respectively. These complexes were characterized by IR, UV/Vis, and EPR spectroscopy, single‐crystal X‐ray crystallography, and temperature dependence magnetic susceptibility measurements (2–300 K) as well as by electrochemical and molar conductivity measurements. In 1, each of the three N‐donor atoms of the binucleating bdpaTCl ligand coordinate to CuII ions, which are further bridged by two OH– anions in a distorted five‐coordinate geometry. In addition, each CuII ion forms a Cu–O semicoordinate bond with an aqua ligand or perchlorato anion. The Cu···Cu distance across the hydroxido bridges is 2.9698(11) Å. In 2, the bdpaTCl ligand acts as bis‐tridentate ligand connecting the two CuII ions, and the five‐coordinate geometry around each copper center is achieved by two terminal chloro ligands. Magnetic measurements revealed strong antiferromagnetic coupling in 1 (J = –311.2 cm–1) and very weak coupling in 2 (J = –2.4 cm–1). DNA cleavage by these two complexes has been investigated (pH = 7.0, 37 °C). Although the bridged dihydroxido complex 1 did not show any detectable cleavage for DNA, significant cleavage was observed with the tetrachloro complex 2. Under pseudo‐Michaelis–Menten kinetic conditions, the kinetic parameters kcat = 2.53 × 10–5 s–1 and KM = 1.44 × 10–4 M were determined for 2. The kcat value corresponds to a 2.5 × 106 fold rate enhancement over noncatalyzed DNA. Electrophoretic experiments conducted in the presence and absence of oxidative scavengers DMSO, KI, and NaN3, and radical promoter H2O2 provide evidence for the oxidative cleavage of DNA by hydroxy radicals and hydrogen peroxide species.
Bone mineral imaged in vivo by 31P solid state MRI of human wrists
Authors: Wu Yaotang , Reese Timothy G. , Cao Haihui , Hrovat Mirko I. , Toddes Steven P. , Lemdiasov Rostislav A. , Ackerman Jerome L. 
Published: July 2011

AbstractPurpose:To implement solid state 31P MRI (31P SMRI) in a clinical scanner to visualize bone mineral.Materials and Methods:Wrists of seven healthy volunteers were scanned. A quadrature wrist 31P transmit/receive coil provided strong B1 and good signal‐to‐noise ratio (SNR). A 1H‐31P frequency converter was constructed to enable detection of the 31P signal by means of the 1H channel. Data points lost in the receiver dead time were recovered by a second acquisition with longer dwell time and lower gradient strength.Results:Three‐dimensional 31P images, showing only bone mineral of the wrist, were obtained with a clinical 3 Tesla (T) scanner. In the best overall case an image with isotropic resolution of ∼5.1 mm and SNR of 30 was obtained in 37 min. 31P NMR properties (resonance line width 2 kHz and T1 17–19 s) of in vivo human bone mineral were measured.Conclusion:In vivo 31P SMRI visualization of human wrist bone mineral with a clinical MR scanner is feasible with suitable modifications to circumvent the scanners' limitations in reception of short‐T2 signals. Frequency conversion methodology is useful for implementing 31P SMRI measurements on scanners which do not have multinuclear capability or for which the multinuclear receiver dead time is excessive. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Monitoring neoadjuvant chemotherapy in breast cancer patients: Improved MR assessment at 3 T?
Authors: Heldahl Mariann G. , Lundgren Steinar , Jensen Line R. , Gribbestad Ingrid S. , Bathen Tone F. 
Published: July 2011

AbstractPurpose:To investigate possible improvements in predicting the response to neoadjuvant chemotherapy (NAC) at 3 T for locally advanced breast cancer (LABC).Materials and Methods:Dynamic contrast‐enhanced magnetic resonance (DCE‐MR) images acquired before and during NAC were retrospectively analyzed in 85 patients. Tumor volume and diameter, three volumes based on the shape of the enhancement curve, relative signal intensity, area under the curve, and the signal‐to‐noise ratio were extracted. Differences between responders and nonresponders at the same and between MR timepoints during treatment were evaluated.Results:A higher signal‐to‐noise ratio was observed on 3 T images compared to 1.5 T, and 3 T revealed more significant findings related to response compared to 1.5 T. The DCE‐MRI‐derived volume parameters were the earliest predictors of response at both 1.5 and 3 T.Conclusion:Our results show that 3 T provides an improved assessment of the response to NAC in LABC patients, where the MR determined tumor volume reduction before the second cycle of NAC was the strongest and earliest predictor of a response. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Ventilation/perfusion imaging of the lung using ultra‐short echo time (UTE) MRI in an animal model of pulmonary embolism
Authors: Togao Osamu , Ohno Yoshiharu , Dimitrov Ivan , Hsia Connie C. , Takahashi Masaya 
Published: July 2011

AbstractPurpose:To test the feasibility of ultra‐short echo time (UTE) MRI for assessment of regional pulmonary ventilation/perfusion in a standard 3 Tesla clinical MRI system.Materials and Methods:MRI of the lungs was conducted with an optimized three‐dimensional UTE sequence in normal rats and in a rat model of pulmonary embolism (PE) induced by a blood clot. Changes in signal intensities (SIs) due to inhalation of molecular oxygen or intravenous (i.v.) injection of Gd, which represents the distribution of ventilation and perfusion, respectively, were assessed in the lung parenchyma.Results:The UTE MRI with a TE of 100 μs could detect and map the changes in SI of the lung parenchyma due to the inhalation of 100% oxygen or i.v. injection of Gd in normal rats. Reduced T1 resulting from oxygen inhalation was also quantified. These changes were not observed on the images that were obtained simultaneously with a conventional range of TE (2.3 ms). Furthermore, the method could delineate the embolized lesions where the lung ventilation and perfusion were mismatched in a rat model with PE.Conclusion:These results show the feasibility and diagnostic potential of UTE MRI for the assessment of pulmonary ventilation and perfusion which is essential for the evaluation of a variety of lung diseases. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Age‐related and regional changes of aortic stiffness in the marfan syndrome: Assessment with velocity‐encoded MRI
Authors: Westenberg Jos J.M. , Scholte Arthur J.H.A. , Vaskova Zuzana , van der Geest Rob J. , Groenink Maarten , Labadie Gerda , van den Boogaard Pieter J. , Radonic Teodora , Hilhorst‐Hofstee Yvonne , Mulder Barbara J.M. , Kroft Lucia J.M. , Reiber Johan H.C. , de Roos Albert 
Published: July 2011

AbstractPurpose:To study age‐related change in aortic stiffness in patients with Marfan syndrome (MFS) versus healthy volunteers using velocity‐encoded (VE) MRI.Materials and Methods:Twenty‐five MFS patients (age range, 18–63 years; mean age 36 ± 14 years, 13 men) and 25 age‐/gender‐matched healthy volunteers were examined with VE‐MRI. Aortic stiffness was expressed by pulse wave velocity (PWV), assessed in the proximal and distal part of the aorta and in the total aorta. PWV was compared between patients and volunteers and age‐relation was determined by linear regression.Results:PWV was significantly higher in all parts of the aorta in patients when compared with healthy volunteers (proximal aorta 5.7 ± 1.5 m/s versus 4.8 ± 0.9 m/s, distal aorta 6.4 ± 2.4 m/s versus 5.0 ± 1.2 m/s and total aorta 5.9 ± 1.7 m/s versus 4.9 ± 1.1 m/s, all P < 0.004). PWV correlated significantly with age (Pearson R between 0.45 and 0.94). Only in the proximal aorta, the increase in PWV with age was significantly higher in patients (7 ± 2 cm/s increase with age) than in volunteers (3 ± 1 cm/s increase, P = 0.03); in the distal or total aorta, the increase in PWV with age was not different between patients and volunteers.Conclusion:Velocity‐encoded MRI detects more pronounced age‐related aortic stiffening in the proximal aorta in MFS patients versus healthy volunteers, suggesting more severe wall disease in MFS. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Quantitative contrast‐enhanced first‐pass cardiac perfusion MRI at 3 tesla with accurate arterial input function and myocardial wall enhancement
Authors: Breton Elodie , Kim Daniel , Chung Sohae , Axel Leon 
Published: July 2011

AbstractPurpose:To develop, and validate in vivo, a robust quantitative first‐pass perfusion cardiovascular MR (CMR) method with accurate arterial input function (AIF) and myocardial wall enhancement.Materials and Methods:A saturation‐recovery (SR) pulse sequence was modified to sequentially acquire multiple slices after a single nonselective saturation pulse at 3 Tesla. In each heartbeat, an AIF image is acquired in the aortic root with a short time delay (TD) (50 ms), followed by the acquisition of myocardial images with longer TD values (∼150–400 ms). Longitudinal relaxation rates (R1 = 1/T1) were calculated using an ideal saturation recovery equation based on the Bloch equation, and corresponding gadolinium contrast concentrations were calculated assuming fast water exchange condition. The proposed method was validated against a reference multi‐point SR method by comparing their respective R1 measurements in the blood and left ventricular myocardium, before and at multiple time‐points following contrast injections, in 7 volunteers.Results:R1 measurements with the proposed method and reference multi‐point method were strongly correlated (r > 0.88, P < 10−5) and in good agreement (mean difference ±1.96 standard deviation 0.131 ± 0.317 / 0.018 ± 0.140 s−1 for blood/myocardium, respectively).Conclusion:The proposed quantitative first‐pass perfusion CMR method measured accurate R1 values for quantification of AIF and myocardial wall contrast agent concentrations in 3 cardiac short‐axis slices, in a total acquisition time of 523 ms per heartbeat. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.