bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recovery of cellular E‐cadherin precedes replenishment of estrogen receptor and estrogen‐dependent proliferation of breast cancer cells rescued from a death stimulus
Authors: Malaguti Claudia , Rossini Gian Paolo 
Published: October 2002

AbstractLoss of estrogen‐responsiveness and impaired E‐cadherin expression/function has been linked to increased metastatic potential of breast cancer cells. In this study, we report that proliferation of breast cancer cells can resume following removal of a toxic stimulus causing severe impairment of cell adhesion and estrogen responsiveness. This type of response was induced by okadaic acid (OA) in MCF‐7 cells, and was accompanied by an almost complete block of DNA synthesis, loss of cell–cell contact and cell detachment from culture dishes, loss of estrogen receptor (ER), progesterone receptor (PR) and E‐cadherin, whereas only a weak, if any, inhibition of protein synthesis could be observed. These responses were detected in MCF‐7 cells after a 1‐day treatment with 50 nM OA, and could be reversed if OA‐treated cells were recovered in a culture medium devoid of the toxin, so that rescued cells resumed growth 8–12 days after replating. By pulse‐chase experiments, we found that protein synthesis was not significantly affected in rescued cells, whose DNA synthesis, instead, was almost completely blocked during the first days of MCF‐7 cell rescue from OA treatment. We also analyzed E‐cadherin, mitogen activated protein kinase isoforms ERK1 and ERK2, Bcl‐2 and BAX proteins during the rescue of MCF‐7 cells from OA‐induced cell death, and found that their expression followed temporally defined patterns. Cellular levels of E‐cadherin returned to control levels within the first days of the rescue, followed by ER, ERK1, and ERK2, and finally by Bcl‐2 and BAX proteins. Under our experimental conditions, restoration of cell adhesion did not require a functional ER system, but recovery of a normal ER pool accompanied resumption of estrogen‐dependent proliferation of OA‐treated MCF‐7 cells. © 2002 Wiley‐Liss, Inc.
Heparan sulfate depletion within pulmonary fibroblasts: Implications for elastogenesis and repair
Authors: Buczek‐Thomas Jo Ann , Chu Chia L. , Rich Celeste B. , Stone Phillip J. , Foster Judith A. , Nugent Matthew A. 
Published: October 2002

AbstractWe investigated the role of sulfated proteoglycans in regulating extracellular matrix (ECM) deposition in pulmonary fibroblast cultures. Fibroblast cultures were subject to pharmacologic and enzymatic interventions to modify sulfated proteoglycan levels. Native and proteoglycan‐depleted fibroblasts were treated with porcine pancreatic elastase at 2–4‐day intervals and the elastase‐mediated release of fibroblast growth factor 2 (FGF‐2) and glycosaminoglycans was determined. Elastase treatment released significantly less FGF‐2 and glycosaminoglycans (GAG) from PG‐depleted fibroblasts with respect to native cells. Equilibrium ligand binding studies indicated that 125I FGF‐2 binding at both cell surface receptor and heparan sulfate proteoglycan sites was reduced to different extents based on the method of proteoglycan depletion. Quantitation of elastin protein and message levels indicated that biological sulfation is required for the proper incorporation of tropoelastin into the extracellular matrix. These results suggest that sulfated proteoglycans play a central role in modulating pulmonary fibroblast extracellular matrix composition and are important mediators of elastolytic injury. © 2002 Wiley‐Liss, Inc.
Recent progress in the neurobiology of the vomeronasal organ
Authors: Takami Shigeru 
Published: October 2002

AbstractIn many terrestrial tetrapodes, a pair of vomeronasal organs (VNOs), which are chemosensory apparatuses, are situated at the base of the nasal septum in the anterior nasal cavity. The purposes of this review are to summarize comparative neuroanatomy and to introduce recent progress in neurobiological studies of the VNO. Five types of VNOs can be identifiable in terms of anatomical organization; snakes possess the most complex one. Sensory cells in the VNO, vomeronasal receptor neurons (VRNs), are located in its neuroepithelium, vomeronassal sensory epithelium. The VRNs retain the characteristic of epithelial cells in that they are born continuously from progenitor cells. They contain two prominent subcellular structures: microvilli and extraordinarily large amounts of smooth endoplasmic reticulum and a few unique glycoconjugates. The VRNs express two types of G‐protein ‐subunits: Giα2 and Goα and each of them is coupled with putative pheromone receptors, V1Rs and V2Rs, respectively. Recent physiological and biochemical studies have demonstrated that pheromones depolarize the V1R‐Giα2 and V2R‐Goα VRNs via IP3‐mediated mechanisms. The VRNs do not show adaptation and are ultrasensitive to putative pheromones. Other than being a chemosensory organ, the VNO and its primordium might play important roles for brain development; hypothalamic neurons that produce gonadotropin‐releasing hormone are born in the VNO primordium and a few other neuron‐like cells may be born in the VNO primordium and VNO. In human fetuses, anatomical findings strongly suggest that their VNOs contain a neuroepithelium. By contrast, it is unlikely that adult human VNO serves as a chemosensory organ. Microsc. Res. Tech. 58:228–250, 2002. © 2002 Wiley‐Liss, Inc.
Morphological aspects of particle uptake by lung phagocytes
Authors: Geiser Marianne 
Published: October 2002

AbstractMacrophages residing on the inner epithelial surfaces of airways and alveoli are the only lung phagocytes exposed directly to the environment. Their phagocytic and microbicidal activities are essential for maintaining this organ in a clean and sterile state. The morphology of these phagocytes can be investigated in situ only after implementing special techniques, which involve intravascular triple‐perfusion of aqueous fixatives or instillation of nonpolar ones. Such studies have revealed the engulfment of particles by these cells to be rapid, the process being essentially complete within a day. Particles are entrapped within phagosomes and the host cells eventually transported out of the lungs by mucociliary action, macrophages with higher loads being more rapidly eliminated than those with lower ones. Very small particles or those persisting on the epithelial surfaces may be taken up by the eponymous cells. Translocation of particles into the underlying connective tissue and their subsequent phagocytosis by interstitial macrophages prolongs their retention time in the lungs. The still poorly studied pleural macrophages might be involved in cell‐mediated immune responses within the pleural space. Intravascular pulmonary macrophages figure largely in the phagocytosis of circulating particles. The role played by dendritic cells in particle uptake by the lungs is not well understood. Airway and alveolar macrophages are the primary phagocytes of the lung. In nonoverload situations and for particles >1 μm, a small proportion of those recruited suffices to remove material from the epithelial surface before other phagocytes, with an apparently greater immunological potential, gain access to it. Microsc. Res. Tech. 57:512–522, 2002. © 2002 Wiley‐Liss, Inc.
Behavior of graft and host cells in underlying subchondral bone after transplantation of osteochondral autograft
Authors: Oshima Yasushi , Watanabe Nobuyoshi , Matsuda Ken‐Ichi , Takenaka Nobuyuki , Kawata Mitsuhiro , Takai Shinro 
Published: October 2002

AbstractTransplantation of osteochondral autograft is widely used as a therapeutic strategy for the defect of articular cartilage. In the repair process, although underlying subchondral bone becomes necrotic and then is followed by bone reconstruction, the fate of graft and host cells during remodeling of underlying subchondral bone has not been elucidated. The objectives of this study were to establish a method to follow graft and host cells after transplantation of osteochondral autograft, and to elucidate the fate of both graft and host cells during remodeling of underlying subchondral bone. For these purposes, autologous transplantation models employing transgenic rats and wild‐type rats, which were genetically identical to each other except for transgenes, were used. Two transplantation models were designed so that either the graft or the host cells had transgenes. Model I: transgenic rats were the donor, and wild‐type rats were the recipient; model II: conversely, wild‐type rats were the donor, and transgenic rats were the recipient. The grafted bone marrow cells and osteocytes in the trabeculae survived in the graft at 3 weeks after transplantation. Invasion of the host bone marrow cells into the graft was also found. Thus, bone marrow cells in the host as well as both bone marrow cells and osteocytes in the graft could potentially participate in the remodeling of underlying subchondral bone. Furthermore, the interface between graft and host was consisted with both graft and host derived cells. Since new bone formation was found in this space, both graft and host cells could have the potential to contribute to remodeling of underlying subchondral bone. The two models of the transplantations using the transgenic rats were found to be beneficial in following graft cells as well as host cells and in understanding their function on healing after autologous transplantation. Microsc. Res. Tech. 58:19–24, 2002. © 2002 Wiley‐Liss, Inc.
Response of donor and recipient cells after transplantation of cells to the ligament and tendon
Authors: Hildebrand Kevin A. , Jia Fengyan , Woo Savio L.‐Y. 
Published: October 2002

AbstractThe mechanical properties of healing ligaments and tendons are not comparable to those of normal tissue. To improve the quality of the ligament healing, therapeutic strategies include gene transfer or placement of mesenchymal stem cells at the healing site. Studies show that marker genes, growth factors, and antisense oligonucleotides can be delivered to both normal and healing ligaments and tendons by gene transfer. Cells with and without genetic modification have been successfully transplanted to ligaments and tendons and remain viable. Tendon healing can be improved using collagen gel implants seeded with autologous mesenchymal stem cells. Even though these early results are encouraging, more work is required regarding the response of the recipient site to donor cells or vectors. Microsc. Res. Tech. 58:34–38, 2002. © 2002 Wiley‐Liss, Inc.
Method for preparing thin sections of untreated equine hoof horn for electron microscopic examination
Authors: Budras Klaus‐Dieter , Schiel Christina , Mülling Christoph Karl Wolfgang , Patan Bianca 
Published: October 2002

AbstractThe preparation of hard tissues such as the equine hoof horn for electron microscopic examination is very difficult. In particular the penetration of fixatives and chemicals used during fixation and embedding is a problem. The objective of this study was to find and implement an alternative method enabling the preparation of high‐quality thin sections of hoof horn and other hard tissue, which maintains the hard tissue ultrastructure and can be used for immuno‐labeling. Compared to commonly used fixation and embedding techniques, the preparation of thin sections from untreated material method saves time and material and provides equivalent ultrastructural information. Furthermore, thin sections from untreated material are significantly larger and more homogeneous, more resistant to the electron ray, as well as more suitable for sectioning. The electron microscopical pictures obtained allow a comparison to previous test results achieved with fixed and embedded material. Using the preparation of thin sections from untreated material method, fixation and embedding artifacts are avoided, providing a clearer interpretation of the electron microscopical findings. Considerable advantages are achieved by using immunohistochemical techniques with untreated horn specimens because fixation invariably decreases antigenicity. Microsc. Res. Tech. 58:114–120, 2002. © 2002 Wiley‐Liss, Inc.
Neurotrophins and their receptors in the primary olfactory neuraxis
Authors: Carter Lindsay A. , Roskams A. Jane 
Published: October 2002

AbstractThe primary olfactory pathway is an elegant and simple system in which to study neurogenesis and neuronal plasticity because of the simple fact that olfactory receptor neurons (ORNs) are continually generated throughout the adult lifetimes of vertebrates. Thus, neuronal birth, differentiation, survival, axon pathfinding, target recognition, synapse formation, and cell death are developmental events that can be examined in the mature olfactory epithelium (OE). Neurotrophins (nerve growth factor, brain‐derived neurotrophic factor, and neurotrophin 3, and 4/5) are a family of bioactive peptides that exert their effects by interacting with high‐ and low‐affinity receptors on the surfaces of responsive cells, and have been implicated in several stages of neuronal development throughout the central and peripheral nervous system (CNS and PNS). There has been significant interest within the olfactory community as to how these multifunctional peptides might regulate the cycle of degeneration and regeneration of olfactory receptor neurons. The focus of this review is to highlight what is known about the actions of neurotrophins in the primary olfactory pathway, and to pinpoint future directions that will enable us to further understand their role in olfactory receptor neuron development and turnover. Microsc. Res. Tech. 58:189–196, 2002. © 2002 Wiley‐Liss, Inc.
Experimental manipulation of steroid concentrations in circulation and in egg yolks of turtles
Authors: JANZEN FREDRIC J. , WILSON MATTHEW E. , TUCKER JOHN K. , FORD STEPHEN P. 
Published: October 2002

AbstractSteroid hormones in egg yolks are increasingly recognized as an important component of maternal and offspring fitness in oviparous vertebrates. Yet, except for in birds, the mechanism by which females allocate these resources is poorly understood. We manipulated systemic levels of hormones in reproductively mature female red‐eared slider turtles (Trachemys scripta elegans) with silastic implants to test the hypothesis that hormones are allocated to developing follicles as a quantitative function of circulating levels in the females. Turtles exhibited similar amounts (<1 ng/ml) of circulating steroids (dihydrotestosterone, estradiol‐17β, or testosterone) in early September immediately prior to experimental manipulation. After treatment with silastic implants, circulating levels of steroids increased markedly. By the following April after hibernation, circulating levels of dihydrotestosterone had returned to preimplantation levels, but circulating levels of estradiol‐17β and testosterone in estradiol‐17β‐ and testosterone‐treated turtles, respectively, remained substantially elevated through April. Focusing on testosterone, we detected nearly six‐fold higher concentrations in yolk from mature follicles from testosterone‐treated turtles than in yolk from mature follicles from control turtles. Our results provide support for the hypothesis that concentrations of steroids in egg yolks of turtles reflect circulating concentrations of steroids during follicular development rather than the hypothesis that females selectively allocate specific amounts of steroid hormones to each egg separately. Our findings also highlight an unambiguous physiological mechanism by which nongenetic maternal effects in oviparous species can directly influence the nutritional milieu experienced by developing embryos. © 2002 Wiley‐Liss, Inc.
Maternally derived yolk hormones vary in follicles of the painted turtle, Chrysemys picta
Authors: BOWDEN RACHEL M. , EWERT MICHAEL A. , FREEDBERG STEVEN , NELSON CRAIG E. 
Published: October 2002

AbstractThe transfer of hormones from a female to her offspring is known to occur in egg laying vertebrates, and the potential for these early, maternally derived hormones to influence sex determination in reptiles with temperature‐dependent sex determination is intriguing. In the present study, we examine variation in the concentrations of progesterone, testosterone, and estradiol among three follicle size classes within a female painted turtle (Chrysemys picta) and among females across four periods that span the pre‐ to post‐nesting season. Females were collected, and both follicles and shelled eggs (when present) were harvested for hormone analysis. Progesterone levels did not vary seasonally. However, the concentration of progesterone did vary among and within follicle classes, and was primarily dependent upon ovulatory state: Recently ovulated follicles (as yolks within shelled eggs) contained significantly more progesterone than unovulated follicles. Concentrations of testosterone were low and did not vary either among size classes or across the season. Estradiol levels decreased with increasing follicle size and were higher later in the nesting season. Thus, hormone concentrations varied among follicle sizes and states but in patterns that differed among hormones. This variation has the potential to influence sex determination. © 2002 Wiley‐Liss, Inc.
Elevated levels of trimethylamine oxide in deep‐sea fish: evidence for synthesis and intertissue physiological importance
Authors: TREBERG JASON R. , DRIEDZIC WILLIAM R. 
Published: October 2002

AbstractTissue levels of trimethylamine oxide (TMAO) were compared for seven teleost and two elasmobranch species captured from three depth ranges: shallow (<150 m), moderate (500–700 m), and deep (1,000–1,500 m). Within the teleosts, the deep‐caught species had significantly greater TMAO content than shallow‐ or moderate‐caught species. In all teleosts, muscle had substantially more TMAO than all other tissues. Kidney or, in some cases, liver had elevated trimethylamine (TMA) content, 2.20–9.65 mmol/kg, along with appreciable trimethylamine oxidase (TMAoxi) activity, suggesting active TMAO synthesis. No correlation was found between TMAoxi activity and TMAO content. The elasmobranchs in this study, Squalus acanthias and Centroscyllium fabricii from shallow and deep water, respectively, were both squaliform sharks. The deep‐caught species had significantly more TMAO in all tissues than the shallow species. Furthermore, urea was significantly less in the deep species in all tissues except liver, while the urea:TMAO ratio was significantly less in all tissues. As with teleosts, the TMAO content of muscle was substantially higher for both elasmobranchs than in all other tissues. TMAoxi was below levels of detection in both elasmobranch species, suggesting that TMAO is obtained solely from the diet. This study expands the trend of increased muscle TMAO in deep‐sea fish to a variety of other tissues. The accumulation of TMAO in various tissues in deep‐sea teleosts and the accumulation of TMAO and concurrent urea decrease in a deep‐sea elasmobranch in comparison to a shallow water species strongly support the contention that TMAO is of physiological importance in deep‐sea fish. © 2002 Wiley‐Liss, Inc.
Aperture pattern ontogeny in angiosperms
Authors: Ressayre Adrienne , Godelle Bernard , Raquin Christian , Gouyon Pierre Henri 
Published: October 2002

AbstractPollen grains display a wide range of variation in aperture number and arrangement (pattern) in angiosperms. Apertures are well‐defined areas of the pollen wall surface that permit pollen tube germination. For low aperture numbers, aperture patterns are characteristic of the major taxonomic divisions of angiosperms. This paper presents a developmental model that explains most of the aperture patterns that are recorded in angiosperms. It is based on the analysis of the different events that occur during meiosis and lead to microspore differentiation. It demonstrates that variation occurring during meiosis in angiosperms is sufficient to produce the core morphological set of the most commonly observed pollen morphologies. J. Exp. Zool. (Mol. Dev. Evol.) 294:122–135, 2002. © 2002 Wiley‐Liss, Inc.
Separation index of a graph
Authors: Vince Andrew 
Published: October 2002

AbstractThe concepts of separation index of a graph and of a surface are introduced. We prove that the separation index of the sphere is 3. Also the separation index of any graph faithfully embedded in a surface of genus g is bounded by a funtion of g. © 2002 Wiley Periodicals, Inc. J Graph Theory 41: 53–61, 2002
Aspects of outreach: a framework for discussion of the social benefits of microfinance
Authors: Schreiner Mark 
Published: October 2002

AbstractWide agreement about the goal of microfinance—to improve the welfare of the poor—has not led to wide agreement about how best to achieve that goal. To aid discussion, I propose a framework for outreach—the social benefits of microfinance—in terms of six aspects: worth, cost, depth, breadth, length, and scope. The framework encompasses both the poverty approach to microfinance and the self‐sustainability approach. The poverty approach assumes that great depth of outreach can compensate for narrow breadth, short length, and limited scope. The self‐sustainability approach assumes that wide breadth, long length, and ample scope can compensate for shallow depth. I show how to use the framework for BancoSol of Bolivia. Copyright © 2002 John Wiley & Sons, Ltd.
Synthesis of [18F]‐labeled 2′‐deoxy‐2′‐fluoro‐5‐methyl‐1‐β‐D‐arabinofuranosyluracil ([18F]‐FMAU)
Authors: Alauddin Mian M. , Conti Peter S. , Fissekis John D. 
Published: October 2002

AbstractSynthesis of 2′‐deoxy‐2′‐[18F]fluoro‐5‐methyl‐1‐β‐D‐arabinofuranosyluracil ([18F]‐FMAU) is reported. 2‐Deoxy‐2‐[18F]fluoro‐1,3,5‐tri‐O‐benzoyl‐α‐D‐arabinofuranose 2 was prepared by the reaction of the respective triflate 1 with tetrabutylammonium[18F]fluoride. The fluorosugar 2 was converted to its 1‐bromo‐derivative 3 and coupled with protected thymine 4. The crude product mixture (5a and 5b) was hydrolyzed in base and purified by HPLC to obtain the radiolabeled FMAU 6a. The radiochemical yield of 6a was 20–30% decay corrected (d.c.) in four steps with an average of 25% in four runs. Radiochemical purity was >99% and average specific activity was 2300 mCi/μmol at the end of synthesis (EOS). The synthesis time was 3.5–4.0 h from the end of bombardment (EOB). Copyright © 2002 John Wiley & Sons, Ltd.
Identification of epitope‐like consensus motifs using mRNA display
Authors: Baggio Rick , Burgstaller Petra , Hale Stephen P. , Putney Andrew R. , Lane Meghan , Lipovsek Dasa , Wright Martin C. , Roberts Richard W. , Liu Rihe , Szostak Jack W. , Wagner Richard W. 
Published: October 2002

AbstractThe mRNA display approach to in vitro protein selection is based upon the puromycin‐mediated formation of a covalent bond between an mRNA and its gene product. This technique can be used to identify peptide sequences involved in macromolecular recognition, including those identical or homologous to natural ligand epitopes. To demonstrate this approach, we determined the peptide sequences recognized by the trypsin active site, and by the anti‐c‐Myc antibody, 9E10. Here we describe the use of two peptide libraries of different diversities, one a constrained library based on the trypsin inhibitor EETI‐II, where only the six residues in the first loop were randomized (6.4 × 107 possible sequences, 6.0 × 1011 sequences in the library), the other a linear‐peptide library with 27 randomized amino acids (1.3 × 1035 possible sequences, 2 × 1013 sequences in the library). The constrained library was screened against the natural target of wild‐type EETI, bovine trypsin, and the linear library was screened against the anti‐c‐myc antibody, 9E10. The analysis of selected sequences revealed minimal consensus sequences of PR(I,L,V)L for the first loop of EETI‐II and LISE for the 9E10 epitope. The wild‐type sequences, PRILMR for the first loop of EETI‐II and QKLISE for the 9E10 epitope, were selected with the highest frequency, and in each case the complete wild‐type epitope was selected from the library. Copyright © 2002 John Wiley & Sons, Ltd.