bluuebunny/crossref_metadata_2025_split huggingface dataset:
Specific inhibition of mouse oocyte nuclear protein phosphatase‐1 stimulates germinal vesicle breakdown
Authors: Swain Jason E. , Wang Xia , Saunders Thomas L. , Dunn Rodney , Smith Gary D. 
Published: March 2003

AbstractOkadaic acid (OA)‐induced germinal vesicle breakdown (GVBD) and localization of protein phosphatase‐1 (PP1) in oocyte nuclei are suggestive of PP1's role in regulating oocyte GVBD. To explore this possibility, we microinjected protein phosphatase (PP) inhibitors OA, anti‐PP1 antibody (anti‐PP1), PP1 inhibitor I2, and anti‐PP2A antibody (anti‐PP2A) into nuclei of roscovitine (ROSC)‐arrested mouse oocytes. Oocytes were also injected with recombinant PP1 in the absence of ROSC. Oocytes were assessed for GVBD and metaphase II (MII) development at 2 and 18 hr post‐injection. Data were analyzed using Cochran‐Mantel‐Haenszel Statistics adjusted for time. Microinjection of OA significantly enhanced GVBD in comparison to controls at 2 and 18 hr (P < 0.01), yet had no effect on MII development. Similarly, microinjection of anti‐PP1 resulted in significantly higher levels of GVBD compared to controls at 2 and 18 hr (P < 0.01). Interestingly, anti‐PP1 microinjection also tended to enhance MII development at 18 hr in comparison to controls (P < 0.09). Microinjection of I2, anti‐PP2A, and PP1 had no effect on GVBD or MII development. If reduction of PP1 activity was important for GVBD, one would anticipate an endogenous means of regulating PP1 activity at this developmental stage. In somatic cells, phosphorylation of PP1 at Thr320 causes PP1 inactivation. Germinal vesicle‐intact oocytes did not contain phosphorylated PP1, as determined using a specific Thr320‐Phospho‐PP1 antibody, Western blot analysis, and confocal immunocytochemistry. At or around the time of GVBD, oocyte PP1 became phosphorylated at Thr320, which remained phosphorylated through MII development. These data indicate that inhibition of intra‐nuclear PP1, through specific antibody neutralization, mimics OA‐stimulated GVBD, providing the first direct evidence that nuclear PP1 is involved in regulation of oocyte nuclear membrane integrity. In addition, phosphorylation of PP1 occurs at/or around GVBD indicating that inactivation of PP1 is an important intracellular event in regulation of nuclear envelope dissolution at GVBD. Mol. Reprod. Dev. 65: 96–103, 2003. © 2003 Wiley‐Liss, Inc.
Immunohistochemical localization of steroidogenic enzymes in human follicle following xenotransplantation of the human ovarian cortex into NOD‐SCID mice
Authors: Sato Yumi , Terada Yukihiro , Utsunomiya Hiroki , Koyanagi Yoshio , Ito Mamoru , Miyoshi Ichiro , Suzuki Takashi , Sasano Hironobu , Murakami Takashi , Yaegashi Nobuo , Okamura Kunihiro 
Published: March 2003

AbstractThere have been reports of successful follicular growth following xenogenic transplantation of the human ovarian cortex into immunodeficient mice. In this study, we examined the immunohistochemical expression and localization of steroidogenic enzymes in the graft of nonpathological human ovary following xenogenic transplantation into nonobese diabetic severe combined immune deficient (NOD‐SCID) mice. We studied human follicles following xenotransplantation into NOD‐SCID mice using immunohistochemistry antibodies against the cell proliferation marker (Ki 67), steroidogenic enzymes P450 cholesterol side chain cleavage (P450 scc), 3β‐hydroxysteroid dehydrogenase (3β‐HSD), cytochrome P450 17α hydroxylase (P450 c17), cytochrome P450 aromatase (P450 arom), androgen receptor (AR), estrogen receptor (ER), and Ad4‐binding protein (Ad4BP), a transcription factor for all steroidogenic P450 genes. In the pre‐antral follicles of these grafts, Ki 67 and Ad4BP were detected in both the theca and granulosa cell layer. P450 scc, P450 c17, 3β‐HSD, and AR were present in only the theca cell layer, observations of which were consistent with the findings of nonpathological human ovarian cortex. P450 arom and ER were not detected in these grafts, however, and these follicles did not possess any specific feature of a dominant follicle. These findings suggest that the expression of steroidogenic enzymes in human follicles following xenogenic transplantation into NOD‐SCID mice is similar to that of nonpathological human ovaries. However, these follicles do not possess any features of dominant follicles, which are known to develop into the corpus luteum. Mol. Reprod. Dev. 65: 67–72, 2003. © 2003 Wiley‐Liss, Inc.
TUNEL analyses of bovine blastocysts after culture with EGF and IGF‐I
Authors: Sirisathien S. , Brackett B.G. 
Published: March 2003

AbstractExperiments were carried out to investigate the beneficial effects of IGF‐I or EGF on bovine embryo development in chemically defined embryo culture media and resultant incidences of nuclear DNA fragmentation as an indication of embryo quality. Presumptive IVF zygotes were randomly cultured in either control (with no added growth factor) or treatment groups, i.e., with 50 ng/ml IGF‐I (experiment 1) or 5 ng/ml EGF (experiment 2). IGF‐I supplemented to culture media significantly improved proportions of blastocysts from oocytes inseminated compared to untreated controls (38.0% vs. 28.5%). Only embryos reaching the blastocyst stage on day 8 showed significant effects of IGF‐I treatment by resulting in higher blastocyst cell numbers (162 vs. 141) and lower percentages of TUNEL positive nuclei (2.1% vs. 3.3%) when compared to controls. Blastocyst development from oocytes was also improved by EGF supplementation compared to untreated controls (38.5% vs. 30.7%). Cell numbers of either day 7 or day 8 blastocysts were not affected by EGF treatment, nor were percentages of TUNEL positive nuclei when compared with controls. Similar proportions of parthenogenetically activated oocytes developed to blastocysts as for inseminated oocytes (28.8%). Parthenogenetic blastocysts contained fewer cells (93) and an increased percentage of TUNEL positive nuclei (5.7%) than were found for IVF embryos. Mol. Reprod. Dev. 65: 51–56, 2003. © 2003 Wiley‐Liss, Inc.
Amplification of representative cDNA pools from single human oocytes and pronucleate embryos
Authors: Metcalfe Anthony D. , Bloor Debra J. , Lieberman Brian A. , Kimber Susan J. , Brison Daniel R. 
Published: March 2003

AbstractIn the human embryo, gene expression studies have been hindered by the scarcity of material and the fact that in vitro fertilisation (IVF) embryos available for research are usually of poor quality and are, therefore, not representative of normal development. This has led most authors to study individual human embryos, using conventional RT‐PCR strategies, which permit analysis of only a few genes. Variability in the expression of genes between individual embryos is characteristic of these studies. In this study, a global RT‐PCR strategy has been used, allowing the analysis of an almost infinite number of genes from a single embryo. We have used oocytes, which failed to fertilise and representative pronucleate embryos donated from cycles in which the patient conceived, to investigate possible variability in transcript abundance between individual embryos. We have screened oocytes and embryos for a panel of genes including β‐actin (expressed in 24/28 oocytes, 6/6 pronuclear embryos), the integrins β1 (17/28 oocytes, 6/6 pronuclear embryos) and β5 (8/28 oocytes, 5/6 pronuclear embryos), and the apoptotic regulators BCL‐2 (20/28 oocytes, 2/6 pronuclear embryos) and BAX (21/28 oocytes, 5/6 pronuclear embryos). The expression of the pro‐apoptotic regulator BAX increased in human oocytes following prolonged periods of culture. Overall, patterns of gene transcript presence showed variation between embryos and this was independent of either zona removal or lysis conditions. Pronucleate embryos showed less variation, however, even sibling embryos from the patient did not express an identical subset of genes. Mol. Reprod. Dev. 65: 1–8, 2003. © 2003 Wiley‐Liss, Inc.
Decrement in area of muscle responses to repetitive nerve stimulation
Authors: Lo Y.L. , Dan Y.F. , Leoh T.H. , Tan Y.E. , Ratnagopal P. 
Published: March 2003

AbstractMeasurement of the decremental muscle response to repetitive nerve stimulation (RNS) has low yields for the diagnosis of neuromuscular transmission defects compared with single fiber electromyography (SFEMG). We compared area and amplitude of muscle responses to RNS in 87 patients and 30 controls, using SFEMG as the reference standard. Decrement of response area provided additional diagnostic yields of 5.3% to 30% depending on the muscle examined and disease severity, and is recommended as a diagnostic adjunct to measurement of amplitude decrement during RNS. Muscle Nerve 27: 494–496, 2003
Decrement of compound muscle action potential is related to mutation type in myotonia congenita
Authors: Colding‐Jørgensen Eskild , DunØ Morten , Schwartz Marianne , Vissing John 
Published: March 2003

AbstractDecrement of the compound muscle action potential (CMAP) during 10‐HZ repetitive nerve stimulation is thought to be an unusual finding in dominant myotonia congenita, and has not previously been reported in patients with the genetically verified disorder. It was the purpose of the present study to elucidate the relation between decrement and CLCN1 mutation type in myotonia congenita. Decrement and genotypes were studied in eight Danish families with myotonia congenita. Six patients with the known dominant mutation P480L had decrements of 30–84%. Patients heterozygous for the R894X mutation had decrements of 20–47%. Three novel CLCN1 mutations (two dominant and one recessive) were found segregating with the Thomsen/Becker phenotypes. In families with the novel dominant mutations M128V and E193K, decrement was absent in all family members tested. In conclusion, CMAP decrement may be pronounced in dominant myotonia congenita, and the presence of decrement is related to mutation type. Muscle Nerve 27:449–455, 2003
Inherited polyneuropathy in Leonberger dogs: A mixed or intermediate form of Charcot‐Marie‐Tooth disease?
Authors: Shelton G. Diane , Podell Michael , Poncelet Luc , Schatzberg Scott , Patterson Edward , Powell Henry C. , Mizisin Andrew P. 
Published: March 2003

AbstractA spontaneous distal, symmetrical polyneuropathy in related Leonberger dogs with onset between 1 to 9 years of age was characterized clinically, electrophysiologically, histologically, and morphometrically. Exercise intolerance and weakness was associated with a high‐steppage pelvic‐limb gait, a loss or change in the pitch of the bark, and dyspnea. Neurological examination revealed marked atrophy of the distal limb muscles, depressed spinal and cranial nerve reflexes, and weak or absent movement of the laryngeal and pharyngeal muscles. Electrophysiological evaluation was consistent with denervation and was characterized by loss or marked attenuation of compound muscle action potentials and slowed motor nerve conduction velocity. Muscle biopsy specimens showed neurogenic atrophy. Chronic nerve fiber loss associated with decreased myelinated fiber density and a shift of the axonal size–frequency distribution toward smaller fibers was the predominant finding in peripheral nerve specimens. Pedigree analysis of a large multigenerational family, including nine sibships with at least one affected individual, suggested X‐linked inheritance. Mutational and linkage analysis of this family may aid in identification of the chromosomal loci and gene responsible for this inherited axonal neuropathy. Further characterization of this inherited axonal neuropathy may establish the Leonberger dog as a spontaneous animal model of inherited axonal neuropathy and possibly lead to the discovery of a new gene or genes associated with axonal variants. Muscle Nerve 27: 471–477, 2003
Phrenic nerve palsy as a feature of chronic inflammatory demyelinating polyradiculoneuropathy
Authors: Stojkovic Tanya , De Seze Jérôme , Hurtevent Jean‐François , Fourrier François , Vermersch Patrick 
Published: March 2003

AbstractWe report four patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) who presented with phrenic nerve palsy, which was unilateral in two instances. The two patients with bilateral phrenic nerve involvement required mechanical ventilation. After treatment with intravenous immunoglobulins (IVIg) or steroids, the sensorimotor deficit and respiratory parameters improved in three patients, but the fourth patient remained ventilator dependent and died from pulmonary infection. Although rare, phrenic nerve palsy may be a feature of CIDP and may be responsive to treatment with IVIg or steroids. Muscle Nerve 27: 497–499, 2003
Surface‐initiated polymerization from poly(ethylene terephthalate)
Authors: Roux Stephane , Demoustier‐Champagne Sophie 
Published: March 2003

AbstractThe free‐radical polymerization of styrene initiated from a functionalized poly(ethylene terephthalate) (PET) surface yielded a tethered polymer layer. The anchoring of the initiator species on the PET surface was performed from surface‐reactive groups easily generated by an alkaline hydrolysis of PET. After each surface modification, PET films were characterized by X‐ray photoelectron spectroscopy, measurements of water contact angles, and time‐of‐flight secondary‐ion mass spectrometry. The influence of the polymerization duration, the grafted initiator density, and the grafting mode on the efficiency of the surface‐initiated polymerization of styrene was investigated. In some cases, the tethering of the polystyrene layer on PET could be a reversible process. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1347–1359, 2003
Surface methacrylation and graft copolymerization of ultrafine cellulose fibers
Authors: Liu Haiqing , Hsieh You‐Lo 
Published: March 2003

AbstractUltrafine fibrous (ϕ from 100 to 450 nm) cellulose membranes were generated by electrospinning of cellulose acetate [degree of substitution (DS): 2.45, weight‐average molecular weight: 30,000 Da], followed by alkaline deacetylation. Reaction of these ultrahigh surface‐area cellulose fibers with methacrylate chloride (MACl) produced activated surfaces without altering the fiber morphology. Surface methacrylation of these fibers was confirmed by the acquired hydrophobicity (θwater = 84°) as compared to the originally hydrophilic (θwater = 56°) cellulose. Changing the MACl:OH molar ratios could vary the overall DS of methacrylation. The very low overall DS values indicate the surface nature of the methacrylation reaction. At a DS of 0.17, the thermal properties of the surface methacrylated cellulose resemble those of cellulose derivatives at much higher DS values, an unusual behavior of the ultrafine fibers. The methacrylated cellulose could be further copolymerized with vinyl monomers (methyl methacrylate, acrylamide, and N‐isopropylacrylamide) as linear grafts or three‐dimensional (3D) networks. The morphology of cellulose fibers and the interfiber pore structure were not altered at 15–33% graft levels. This study demonstrates that either linear or 3D networks of vinyl polymers could be efficiently supported on ultrafine cellulose fibrous membranes via surface methacrylation. Through these surface reactions the chemical, thermal, and liquid wetting and absorbent properties of these ultrafine fibrous membranes were significantly altered with no change to the fiber dimensions or interfiber pore morphology. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 953–964, 2003
Real‐time orientation and crystallinity measurements during the isotactic polypropylene film‐casting process
Authors: Lamberti Gaetano , Brucato Valerio 
Published: March 2003

AbstractA method based on Fourier transform infrared (FTIR) transmission spectra is proposed to measure the crystallinity of isotactic polypropylene (iPP) samples. The method parameters were tuned as compared with wide‐angle X‐ray scattering measurements performed on test samples characterized by different crystallinity values obtained by solidification of thin iPP films under several cooling rates in a homemade device. The FTIR dichroic ratio measurements were adopted to measure crystalline and average Hermans' orientation factors of iPP samples obtained by film casting. The crystalline orientation measurement method was validated as compared with the birefringence measurement. The techniques were successfully used in real time during some film‐casting runs with a suitably modified FTIR system made of a spectrometer equipped with two optical guidelines and an external detector. Real‐time measurements are reported and discussed. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 998–1008, 2003
Crystallization kinetics of PGBG4: A sequential poly(ester amide) derived from glycine, 1,4‐butanediol, and adipic acid
Authors: Botines Emma , Franco Lourdes , Rodríguez‐Galán Alfonso , Puiggalí Jordi 
Published: March 2003

AbstractIsothermal crystallization kinetics of a new sequential poly(ester amide) derived from glycine, 1,4‐butanediol, and adipic acid was investigated with differential scanning calorimetry and optical microscopy. The Avrami analysis was performed to obtain the kinetic parameters of primary and secondary crystallization. The experimental data indicate a heterogeneous nucleation with spherical growth geometry for the primary crystallization, whereas a linear growth within formed spherulites is characteristic of the last crystallization stages. The Lauritzen–Hoffman analysis was also undertaken to determine the different crystallization regimes, having estimated the corresponding nucleation constants. Temperature dependence of the normalized crystallization‐rate constants was tested with different theoretical equations. These allow an estimation of a temperature close to 90 °C for the maximum crystallization rate. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 903–912, 2003
Theoretical simulation of thermally induced phase separation in a main‐chain liquid‐crystalline polymer solution
Authors: Kim Doe , Kyu Thein 
Published: March 2003

AbstractPhase diagrams of main‐chain liquid‐crystalline polymer (MCLCP) solutions have been calculated self‐consistently on the basis of a simple addition of the Flory–Huggins free energy for isotropic mixing, the Maier–Saupe free energy for nematic ordering, and the Flory free energy for chain rigidity of the MCLCP backbone. The calculated phase diagram is an upper critical solution type overlapping with the nematic–isotropic transition. The phase diagram consists of liquid–liquid, liquid–nematic, and pure nematic regions. Subsequently, the dynamics of thermally induced phase separation and morphology development have been investigated by the incorporation of the combined free energy density into the coupled time‐dependent Ginzburg–Landau (model C) equations, which involve conserved compositional and nonconserved orientational order parameters. The numerical calculations reveal a variety of the morphological patterns arising from the competition between liquid–liquid phase separation and nematic ordering of the liquid‐crystalline polymer. Of particular interest is the observation of an inflection in the growth dynamic curve, which may be attributed to the nematic ordering of the MCLCP component, which leads to the breakdown of the interconnected domains. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 913–926, 2003
Permafrost aggradation followed by brutal degradation during the upper pleniglacial in Mongolia: the probable response to the H2 Heinrich event at 21 kyr BP
Authors: Bertran Pascal , Fontugne Michel , Jaubert Jacques 
Published: March 2003

AbstractUpper pleniglacial loess and slope deposits in Europe frequently show an intensely cryoturbated gley horizon used as a stratigraphic benchmark level (the Nagelbeek Tongue Horizon). An equivalent horizon has been found in Mongolia, suggesting that it may characterize the whole Eurasiatic continent between latitudes 45° and 50° north. This horizon reflects a very cold episode marked by the aggradation of permafrost, followed by a sudden warming and a probable increase in snowfall, that gave rise to permafrost degradation. The latter episode is indicated by cryoturbation on gentle slopes and plug‐like solifluction or active‐layer sliding on steeper slopes. We correlate these processes to the Heinrich H2 cold event at ca. 21 kyr 14C BP and the following interstade that has been recognized in high‐resolution ice and marine records. Copyright © 2003 John Wiley & Sons, Ltd.
Winter streamflow, ground temperature and active‐layer thickness in Northeast China
Authors: Liu Jingshi , Hayakawa Norio , Lu Mingjiao , Dong Shuhua , Yuan Jinying 
Published: March 2003

AbstractSeasonal freezing and thawing influence the hydrological regimes of winter streamflow in northeast China where abrupt increases of 1.3° C and 2.8° C in the annual and winter air temperatures have occurred since the 1990s. Correlation between winter discharge and soil freezing is based upon hydrometeorological and geocryological data for the last 40 years. A mountainous watershed is used. The active‐layer temperature is estimated by a statistical model derived from annual air temperature, its annual range and the maximum depth of snow cover in January. Results indicate an asymptotic curve between winter streamflow and both thickness of the active layer and winter temperature. They imply that winter streamflow increases with a thickening of the active layer and a decrease in the depth of seasonal frost penetration in winter. Copyright © 2003 John Wiley & Sons, Ltd.
The Singularity Principle and Property of Stewart Parallel Manipulator
Authors: Huang Z. , Chen L. H. , Li Y. W. 
Published: March 2003

AbstractBased on the kinematic relationship of rigid body, this paper presents a new principle and method to analyze the singularity of a Stewart parallel manipulator. We study the sufficient and necessary condition that three velocities of three non‐collinear points in a body can determine a screw motion. All singularities of the Stewart parallel mechanism are classified into three different linear‐complex singularities. The various algebraic and geometrical properties as well as kinematics ones are analyzed in detail in different singular configurations. With the condition above, the singularity loci and distribution characteristics of a 3/6—Stewart parallel manipulator for some orientations of the mobile are studied in an oblique plane and in three‐dimensional space. © 2003 Wiley Periodicals, Inc.
Application of a Service Climbing Robot with Motion Planning and Visual Sensing
Authors: Zhu Jian , Sun Dong , Tso Shiu‐Kit 
Published: March 2003

AbstractThis paper describes an application of a service climbing robot aimed to clean the glass wall of high‐rise buildings. The robot utilizes suction cups to adhere to the glass and moves with a translational mechanism to follow a predetermined path in cleaning the whole glass surface. By a flexible waist, the robot can adjust its posture. The robot has the ability to cross the window frame to clean different sections of the glass wall. A visual sensing system, composed of an omnidirectional CCD camera and two laser diodes, enables the robot to measure its orientation and the distance between the robot and the window frame. The real‐time applications and some experimental results demonstrate the effectiveness of the developed system. © 2003 Wiley Periodicals, Inc.