bluuebunny/crossref_metadata_2025_split huggingface dataset:
Drosophila melanogaster as a complementary system for studying HIV‐1‐related genes and proteins
Authors: Spresser Cole R. , Carlson Kimberly A. 
Published: March 2005

AbstractHuman immunodeficiency virus type 1 (HIV‐1) persists as a pandemic even though new information about the virus is being discovered on a daily basis. If the brain becomes infected, HIV‐1 encephalitis or HIV‐1‐associated dementia may develop. There is much to be learned about the modes of action and mechanisms of genes and proteins, and their interactions that underlie HIV‐1 infection. Drosophila melanogaster has been used successfully to study genes and proteins related to HIV‐1 infection, including but not limited to the disturbance of antimicrobial responses by viral protein U and the identification of D. melanogaster analogs to the serine palmitoyltransferase 5 and 6 proteins that play a role in activation of transcription by the HIV‐1 Tat protein in human cells. We believe that utilizing D. melanogaster as a complementary system for the study of genes and proteins related to HIV‐1 infection will provide useful information that will lead to new studies designed to enhance our understanding of the mechanistic roles of these molecules. In the present study, we focus on the utilization of D. melanogaster as a complementary system for studying HIV‐1 related genes and proteins, why this research should be extended, and why this complementary system is an important method for enhancing our understanding of the genetics involved in HIV‐1 infection. © 2005 Wiley‐Liss, Inc.
Selective caspase activation may contribute to neurological dysfunction after experimental spinal cord trauma
Authors: Knoblach S.M. , Huang X. , VanGelderen J. , Calva‐Cerqueira D. , Faden A.I. 
Published: March 2005

AbstractCaspases are implicated in apoptotic cell death after spinal cord injury (SCI), but the relative contribution of these proteases to the secondary injury process has been only partially described. We examined the activation of caspases 1, 2, 3, 6, 8, and 9 from 1 hr to 7 days after moderate contusion injury induced by a weight‐drop method in the rat. Tissue homogenates from a 1‐cm segment of cord that contained the site of impact were processed by fluorometric enzymatic activity assays and/or immunoblotting methods. Caspases 3, 8, and 9 were activated from 1 to 72 hr after injury, whereas caspases 1, 2, and 6 were not. Double‐label immunohistochemistry utilizing antibodies for CNS cell‐type‐specific markers and active subunits of caspases 3, 8, or 9 showed that, at 4 and 72 hr after injury, these caspases were primarily activated in neurons and oligodendrocytes, rather than in astrocytes. Active caspase subunits were present in neurons within the necrotic lesion core at 4 hr after injury and in cells more than several segments away at 4 or 72 hr after injury. Intrathecal injection of the pan‐caspase inhibitor Boc‐Asp (OMe)‐fluoromethylketone (Boc‐d‐fmk) at 15 min after injury improved locomotor function 21 and 28 days later. Treatment with the selective caspase 3 inhibitor N‐benzyloxycarbonyl‐Asp‐Glu‐Val‐Asp‐fluoromethyl ketone (z‐DEVD‐fmk) improved function at 21 days after injury. These data suggest that caspases 3, 8, and 9 may be differentially activated in white and gray matter after spinal cord trauma and that such activation may contribute to subsequent neurological dysfunction. © 2005 Wiley‐Liss, Inc.
Systematic administration of iptakalim, an ATP‐sensitive potassium channel opener, prevents rotenone‐induced motor and neurochemical alterations in rats
Authors: Yang Yong , Liu Xing , Long Yan , Wang Fang , Ding Jian‐Hua , Liu Su‐Yi , Sun Ye‐Hong , Yao Hong‐Hong , Wang Hai , Wu Jie , Hu Gang 
Published: March 2005

AbstractOur previous studies revealed that iptakalim, a novel ATP‐sensitive potassium channel opener, has a significant neuroprotective function against ischemia in vivo or rotenone‐induced neurotoxicity in vitro. To investigate the potential pharmaceutical benefit of ATP‐sensitive potassium channel openers on neurodegenerative diseases, we studied the effects of iptakalim and diazoxide, a selective mitochondrial ATP‐sensitive potassium channel opener, on the rotenone‐induced nigrostriatal degeneration in rats. Iptakalim (1.5 mg/kg/day, orally) or diazoxide (1.5 mg/kg/day, orally) alone was administered to rats for 3 days, and then for 4 weeks was used daily with an injection of rotenone (2.5 mg/kg/day, subcutaneously) 1 hr later each time. The results showed that rotenone‐infused rats exhibited parkinsonian symptoms and had dopamine depletion in the striatum and substantia nigra. Pretreatment with iptakalim or diazoxide prevented rotenone‐induced catalepsy and the reduction of striatum dopamine contents. Moreover, iptakalim and diazoxide reduced the enzymatic activities and mRNA levels of inducible nitric oxide synthase elicited by chronic administration of rotenone. These neuroprotective effects of iptakalim and diazoxide were abolished by 5‐hydroxydecanoate, a selective mitochondrial ATP‐sensitive potassium channel blocker. In conclusion, our data suggested that mitochondrial ATP‐sensitive potassium channels might play a key role in preventing both parkinsonian symptoms and neurochemistry alterations induced by rotenone in rats. The selective activation of mitochondrial ATP‐sensitive potassium channels may provide a new therapeutic strategy for prevention and treatment of neurodegenerative disorders such as Parkinson's disease. © 2005 Wiley‐Liss, Inc.
Class groups of dihedral extensions
Authors: Lemmermeyer Franz 
Published: April 2005

AbstractLet L/F be a dihedral extension of degree 2p, where p is an odd prime. Let K/F and k/F be subextensions of L/F with degrees p and 2, respectively. Then we will study relations between the p‐ranks of the class groups Cl(K) and Cl(k). (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Minimal regularity of the solution of some boundary value problems of Signorini's type in polygonal domains
Authors: Mercier Denis , Nicaise Serge 
Published: April 2005

AbstractWe study the regularity in Sobolev spaces of the solution of transmission problems in a polygonal domain of the plane, with unilateral boundary conditions of Signorini's type in a part of the boundary and Dirichlet or Neumann boundary conditions on the remainder part. We use a penalization method combined with an appropriated lifting argument to get uniform estimates of the approximated solutions in order to obtain some minimal regularity results for the exact solution. The same method allows us to consider problems with thin obstacles. It can be easily extended to 3D problems. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bounding Poincaré‐Hopf indices and Milnor numbers
Authors: Soares Marcio G. 
Published: April 2005

AbstractWe use Mather's finite determinacy theory and Baum‐Bott's theorem to give sharp bounds for the Poincaré‐Hopf index of a germ of homolorphic vector field with an isolated zero. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Distal enhancer of the mouse FGF‐4 gene and its human counterpart exhibit differential activity: Critical role of a GT box
Authors: Boer Brian , Luster Troy A. , Bernadt Cory , Rizzino Angie 
Published: April 2005

AbstractPrevious studies have shown that there is a strict requirement for fibroblast growth factor‐4 (FGF‐4) during mammalian embryogenesis, and that FGF‐4 expression in embryonic stem (ES) cells and embryonal carcinoma (EC) cells are controlled by a powerful downstream distal enhancer. More recently, mouse ES cells were shown to express significantly more FGF‐4 mRNA than human ES cells. In the work reported here, we demonstrate that mouse EC cells also express far more FGF‐4 mRNA than human EC cells. Using a panel of FGF‐4 promoter/reporter gene constructs, we demonstrate that the enhancer of the mouse FGF‐4 gene is approximately tenfold more active than its human counterpart. Moreover, we demonstrate that the critical difference between the mouse and the human FGF‐4 enhancer is a 4 bp difference in the sequence of an essential GT box. Importantly, we demonstrate that changing 4 bp in the human enhancer to match the sequence of the mouse GT box elevates the activity of the human FGF‐4 enhancer to the same level as that of the mouse enhancer. We extended these studies by examining the roles of Sp1 and Sp3 in FGF‐4 expression. Although we demonstrate that Sp3, but not Sp1, can activate the FGF‐4 promoter when artificially tethered to the FGF‐4 enhancer, we show that Sp3 is not essential for expression of FGF‐4 mRNA in mouse ES cells. Finally, our studies with human EC cells suggest that the factor responsible for mediating the effect of the mouse GT box is unlikely to be Sp1 or Sp3, and this factor is either not expressed in human EC cells or it is not sufficiently active in these cells. Mol. Reprod. Dev. © 2005 Wiley‐Liss, Inc.
Unequal segregation of parental chromosomes in embryonic stem cell hybrids
Authors: Matveeva Natalia M. , Pristyazhnyuk Inna E. , Temirova Symbat A. , Menzorov Alexey G. , Vasilkova Anna , Shilov Alexander G. , Smith Austin , Serov Oleg L. 
Published: April 2005

AbstractChromosome segregation was studied in 14 intra‐ and 20 inter‐specific hybrid clones generated by fusion of Mus musculus embryonic stem (ES) cells with fibroblasts or splenocytes of DD/c mice or Mus caroli. As a control for in vitro evolution of tetraploid karyotype we used a set of hybrid clones obtained by fusion of ES cells (D3) with ES cells (TgTP6.3). Identification of the parental chromosomes in the clones was performed by microsatellite analysis and in situ hybridization with labeled species‐specific probes. Both analyses have revealed three types of clones: (i) stable tetraploid, observed only for ES × ES cell hybrids; (ii) bilateral loss of chromosomes of both ES and somatic partners; (iii) unilateral segregation of chromosomes of the somatic partner. Observed unilateral segregation was extensive in ES–splenocyte cell hybrids, but lower in ES–fibroblast hybrid clones. Developmental state of the somatic partner is presumably responsible for directional chromosome loss. Nonrandom segregation implies that initial differences in the parental homologous chromosomes were not immediately equalized implying at least transient persistence of the differentiated epigenotype. Mol. Reprod. Dev. © 2005 Wiley‐Liss, Inc.
PLAC1 expression increases during trophoblast differentiation: Evidence for regulatory interactions with the fibroblast growth factor‐7 (FGF‐7) axis
Authors: Massabbal Eltayab , Parveen Shanaz , Weisoly D.L. , Nelson D. Michael , Smith S.D. , Fant Michael 
Published: April 2005

AbstractPLAC1 is a recently described, trophoblast‐specific gene that localizes to a region of the X‐chromosome important in placental development. Immunohistochemical analysis demonstrated that PLAC1 polypeptide localizes to the differentiated syncytiotrophoblast throughout gestation (8–41 weeks) as well as a small population of villous cytotrophoblasts. Consistent with these observations, quantitative RT‐PCR demonstrated that PLAC1 mRNA increases more than 300‐fold during cytotrophoblast differentiation in culture to form syncytiotrophoblasts. Agents known to be relevant to trophoblast differentiation were then tested for the ability to influence PLAC1 expression. Fibroblast growth factor‐7 (FGF‐7), also known as keratinocyte growth factor (KGF), stimulated PLAC1 mRNA expression approximately two‐fold in the BeWob30 trophoblast cell line. FGF‐7 stimulation was significantly inhibited by PD‐98059 and wortmannin suggesting mediation via MAP kinase and PI‐3 kinase‐dependent signaling pathways. Interestingly, epidermal growth factor (EGF) treatment of trophoblasts had no effect on PLAC1 expression alone, but potentiated the effect of FGF‐7, suggesting the presence of a regulatory interaction of the two growth factors. FGF‐7 and its receptor, FGFR‐2b, exhibited spatial overlap with PLAC1 suggesting these regulatory interactions are physiologically relevant during gestation. These data demonstrate PLAC1 expression is upregulated during trophoblast differentiation, localizing primarily to the differentiated syncytiotrophoblast. Furthermore PLAC1 expression is specifically regulated by peptide growth factors relevant to trophoblast differentiation. Mol. Reprod. Dev. © 2005 Wiley‐Liss, Inc.
Actions of progesterone on uterine immunosuppression and endometrial gland development in the uterine gland knockout (UGKO) ewe
Authors: Padua Maria B. , Tekin Şaban , Spencer Thomas E. , Hansen Peter J. 
Published: April 2005

AbstractIn ewes, the uterine gland knockout (UGKO) phenotype is caused by neonatal exposure to norgestomet to arrest uterine gland development and produce an adult which has a uterus characterized by the lack of endometrial glands. Since endometrial glands in the sheep produce the lymphocyte‐inhibitory protein, ovine uterine serpin (OvUS), an experiment was conducted with ewes of the UGKO phenotype to evaluate whether the inhibitory actions of progesterone on tissue rejection responses in utero are dependent upon the presence of endometrial glands. Control and UGKO ewes were ovariectomized and subsequently treated with either 100 mg/day progesterone or corn oil vehicle for 30 days. An autograft and allograft of skin were then placed in each uterine lumen and treatments were continued for an additional 30 days before grafts were examined for survival. All autografts survived and had a healthy appearance after histological analysis. Allografts were generally rejected in ewes treated with vehicle but were present for hormone‐treated ewes, regardless of uterine phenotype. Analysis of the histoarchitecture and protein synthetic capacity of the uterus revealed that progesterone induced differentiation of endometrial glands and synthesis and secretion of OvUS in UGKO ewes. The UGKO ewes had reduced density of CD45R+ lymphocytes in the endometrial epithelium and there was a tendency for progesterone to reduce this effect in luminal epithelium. Taken together, results confirm the actions of progesterone to inhibit graft rejection response in utero. Responses of UGKO ewes to progesterone indicate that the hormone can induce de novo development and differentiation of endometrial glands, at least when skin grafts are in the uterus. Mol. Reprod. Dev. © 2005 Wiley‐Liss, Inc.
Developmental capability of denuded bovine oocyte in a Co‐culture system with intact cumulus‐oocyte complexes: Role of cumulus cells, cyclic adenosine 3′,5′‐monophosphate, and glutathione
Authors: Luciano Alberto M. , Lodde Valentina , Beretta Matteo S. , Colleoni Silvia , Lauria Antonio , Modina Silvia 
Published: April 2005

AbstractCumulus oophorus cells have been implicated in the regulation of female gamete development, meiotic maturation, and oocyte‐sperm interaction. Nevertheless, the specific role of cumulus cells (CCs) during the final stages of oocyte maturation and fertilization processes still remains unclear. Several studies have been conducted in order to clarify the role of follicular cells using culture systems where denuded oocytes (DOs) were co‐cultured with isolated CCs, or in the presence of conditioned medium. However, those attempts were ineffective and the initial oocyte competence to become a blastocyst after fertilization was only partially restored. Aim of the present study was to analyze the effect of the interactions between somatic cells and the female gamete on denuded oocyte developmental capability using a system of culture where CCs were present as dispersed CCs or as intact cumulus‐oocyte complexes (COCs) in co‐culture with oocytes freed of CC investment immediately after isolation from the ovary. Moreover, we analyzed the specific role of cyclic adenosine 3′–5′ monophosphate (cAMP) and glutathione (GSH) during FSH‐stimulated maturation of denuded oocyte co‐cultured with intact COCs. Our data confirm that denuded oocyte has a scarce developmental capability, and the presence of dispersed CCs during in vitro maturation (IVM) does not improve their developmental competence. On the contrary, the co‐presence of intact COCs during denuded oocyte IVM partially restores their developmental capability. The absence of CCs investment causes a drop of cAMP content in DOs at the beginning of IVM and the addition of a cAMP analog in the culture medium does not restore the initial oocyte developmental competence. The relative GSH content of denuded oocyte matured in presence of intact COCs is consistent with the partial recovery of their developmental capability. However, the complete restoration of a full embryonic developmental potential is achieved only when DOs are co‐cultured with intact COCs during both IVM and in vitro fertilization (IVF). Our results suggest that the direct interaction between oocyte and CCs is not essential during IVM and IVF of denuded oocyte. We hypothesize that putative diffusible factor(s), produced by CCs and/or by the crosstalk between oocyte and CCs in the intact complex, could play a key role in the acquisition of developmental competence of the denuded female gamete. Mol. Reprod. Dev. © 2005 Wiley‐Liss, Inc.
Ophthalmoplegia due to mitochondrial DNA disease: The need for genetic diagnosis
Authors: Schaefer Andrew M. , Blakely Emma L. , Griffiths Philip G. , Turnbull Douglass M. , Taylor Robert W. 
Published: March 2005

AbstractWe describe a patient with chronic progressive external ophthalmoplegia (CPEO) who underwent muscle biopsy for suspected mitochondrial disease. In spite of normal histocytochemical cytochrome c oxidase (COX) activity and respiratory chain enzyme measurements in muscle, subsequent molecular genetic analysis revealed the presence of a single, large‐scale deletion of mitochondrial DNA (mtDNA). The case serves to illustrate the importance of pursuing the proposed mitochondrial genetic abnormality, even in patients with normal biopsy findings. Muscle Nerve, 2005
Fluctuations in motor output during steady contractions are weakly related across contraction types and between hands
Authors: Shinohara Minoru , Keenan Kevin G. , Enoka Roger M. 
Published: March 2005

AbstractThe presence of differences in motor unit activity across contraction types and between hands suggests that the magnitude of fluctuations in motor output is only weakly related when these conditions are compared. Twenty right‐handed young (24.1 ± 5.3 years) and old (72.5 ± 4.9 years) adults performed three levels (≤40% of maximal force) of isometric and anisometric contractions with the first dorsal interosseous muscle of each hand. The fluctuations in motor output were quantified by the coefficient of variation for force during isometric contractions, and as the standard deviations of acceleration and position during anisometric contractions. There was no effect of age on fluctuations in motor output. The magnitude of the fluctuations in motor output was weakly related across contraction types (r2 < 0.325) and between hands (r2 < 0.262). Furthermore, the standard deviations of acceleration and position during shortening and lengthening contractions were largely unrelated to one another. Because the activity in a motor unit population differed across contraction types and hands during steady contractions, the central nervous system likely employed distinct strategies to accomplish these different tasks. Muscle Nerve, 2005
Influence of knee joint angle on muscle properties of paralyzed and nonparalyzed human knee extensors
Authors: Gerrits Karin H. , Maganaris Constantinos N. , Reeves Neil D. , Sargeant Anthony J. , Jones David A. , de Haan Arnold 
Published: March 2005

AbstractMuscles of individuals with a spinal cord injury (SCI) exhibit an unexpected leftward shift in the force (torque)–frequency relationship. We investigated whether differences in torque–angle relationships between SCI and able‐bodied control muscles could explain this shift. Electrically stimulated knee‐extensor contractions were obtained at knee flexion angles of between 30° and 90°. Torque–frequency relationships were obtained at 30°, 90°, and optimum angle. Optimum angle was not different between groups but SCI‐normalized torques were lower at the extreme angles. At all angles, SCI muscles produced higher relative torques at low stimulation frequencies. Thus, there was no evidence of a consistent change in the length of paralyzed SCI muscles, and the anomalous leftward shift in the torque–frequency relationship was not the result of testing the muscle at a relatively long length. The results provide valuable information about muscle changes occurring in various neurological disorders. Muscle Nerve, 2005
Kinetics of styrene emulsion polymerization above the critical micelle concentration: Effect of the initial monomer concentration on the molecular weight
Authors: Herrera‐Ordonez Jorge , Rivera Oscar , Maldonado‐Textle Hortensia , Ramirez Jorge C. 
Published: March 2005

AbstractThe emulsion polymerization of styrene above the critical micelle concentration has been experimentally studied from a low final polymer content up to a high polymer content (∼50%). A maximum in the molecular weight (M) evolution has been observed in all cases. The presence or absence of such a maximum depends on the relative values of the rate of free‐radical entry (ρ) and the rate of chain transfer to the monomer (KtrCMp, where Ktr is the chain transfer to monomer rate coefficient and CMp is the monomer concentration in particles). If ρ ≪ KtrCMp, M is constant and equal to Kp/Ktr (where Kp is the propagation rate coefficient), except at very low particles sizes typical of the early stages of the reaction, in which the chain length is limited by the particle size. On the other hand, if ρ ≫ KtrCMp, M is determined by both CMp and ρ. It is proposed that ρ is determined by the sum of the entry of the oligomeric radicals formed in the aqueous phase and those contained in particles that undergo limited coagulation. This coagulative entry can become very significant; therefore, reactor hydrodynamics can play a major role in the kinetic behavior observed. Disagreement between Clay and Gilbert's model and molecular weight distribution data can be ascribed, to a lesser or greater extent, to the degree of correctness of the quasi‐steady‐state and instantaneous‐termination approaches. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1963–1972, 2005
The CFTR gene and regulation of its expression
Authors: McCarthy Victoria A. , Harris Ann 
Published: April 2005

AbstractThe cystic fibrosis transmembrane conductance regulator gene (CFTR) shows clear temporal and developmental regulation of its expression. However, there are few well‐defined regulatory elements that control this pattern of expression, and their mechanism of action is poorly understood. We review the structure and organization of the CFTR gene and what is known about its regulation. The CFTR gene promoter is clearly important for maintaining levels of CFTR gene expression, but apparently it does not contain any tissue‐specific elements. Thus tissue‐specificity is probably controlled by sequences lying elsewhere in this large gene. We discuss data from our group and others implicating additional regions of CFTR in regulatory functions, and evaluate candidate transcription factors that may be involved. Further, we summarize aspects of the regulation of the developmental expression of CFTR. Definition of CFTR gene regulatory elements could be of considerable therapeutic significance, since only a small increase in CFTR expression in the correct cell type could alleviate the disease phenotype. Pediatr Pulmonol © 2005 Wiley‐Liss, Inc.