bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel technique to prevent prolapse of the Amplatzer septal occluder through large atrial septal defect
Authors: Wahab H. Abdul , Bairam Amjad R. , Cao Qi‐Ling , Hijazi Ziyad M. 
Published: November 2003

AbstractWe report on a new technique (holding the left atrial disk in the left atrium by a dilator) to prevent prolapse of the left atrial disk of the Amplatzer septal occluder during deployment in large atrial septal defects (ASDs). Two patients underwent successful closure of their ASDs using this new technique. Catheter Cardiovasc Interv 2003;60:543–545. © 2003 Wiley‐Liss, Inc.
An unusual cause of claudication
Authors: Shaw James A. , Gravereaux Edwin C. , Winters Gayle L. , Eisenhauer Andrew C. 
Published: November 2003

AbstractWe describe a case of a patient who presented with claudication 3 months following a coronary angiogram in which the femoral arterial puncture site had been closed with an AngioSeal. The lesion was found to be due to the anchor of the AngioSeal, which embolized during attempted percutaneous revascularization and had to be snared and retrieved to the level of the sheath in the left femoral artery and was then surgically removed. Catheter Cardiovasc Interv 2003;60:562–565. © 2003 Wiley‐Liss, Inc.
Percutaneous recanalization of chronic subclavian artery occlusion using optical coherence reflectometry‐guided radiofrequency ablation guidewire
Authors: Lee Pui‐Yin , Chen Wai‐Hong , Ng William , Lau Chu‐Pak 
Published: November 2003

AbstractSubclavian artery lesion that is associated with low complication rate could be treated by percutaneous intervention effectively. However, the success of endovascular therapy for occlusive lesion may be limited by failure to cross with a guidewire. We describe the use of a system using optical coherence reflectometry for navigation and radiofrequency ablation to enable wire passage through subclavian artery occlusion that could not be crossed by conventional guidewires. Catheter Cardiovasc Interv 2003;60:558–561. © 2003 Wiley‐Liss, Inc.
Cloning of the zebra finch androgen synthetic enzyme CYP17: A study of its neural expression throughout posthatch development
Authors: London Sarah E. , Boulter Jim , Schlinger Barney A. 
Published: November 2003

AbstractMale zebra finches develop a robust neural song system that supports singing, but females have a minimal song circuit and do not sing. Estrogens masculinize the song circuit and are especially potent during the first 3 weeks of posthatch development. The gonads do not seem to supply the masculinizing steroids, implying that another tissue synthesizes steroids. Evidence suggests that the brain is capable of synthesizing neurosteroids, which in developing zebra finches may be required for song system differentiation. Aromatase, the enzyme that synthesizes estrogen from androgen, is equally abundant in male and female brains. To investigate further the potential for neurosteroidogenesis in the zebra finch brain, we cloned and examined the expression of 17α‐hydroxylase/17,20 lyase (CYP17), the enzyme that synthesizes the androgenic substrate for aromatase. We used Northern blots, reverse transcription‐polymerase chain reaction, and in situ hybridization to show that CYP17 is transcribed in developing and adult brains. CYP17 is transcribed at developmental stages and in brain areas potentially important to aspects of the developing song system, although no sex difference was detected in mRNA levels. Our results support the hypothesis that neurosteroids may act to influence brain organization and function in the zebra finch. J. Comp. Neurol. 467:496–508, 2003. © 2003 Wiley‐Liss, Inc.
The visual pulvinar in tree shrews II. Projections of four nuclei to areas of visual cortex
Authors: Lyon David C. , Jain Neeraj , Kaas Jon H. 
Published: November 2003

AbstractPatterns of thalamocortical connections were related to architectonically defined subdivisions of the pulvinar complex and the dorsolateral geniculate nucleus (LGN) in tree shrews (Tupaia belangeri). Tree shrews are of special interest because they are considered close relatives of primates, and they have a highly developed visual system. Several distinguishable tracers were injected within and across cortical visual areas in individual tree shrews in order to reveal retinotopic patterns and cortical targets of subdivisions of the pulvinar. The results indicate that each of the three architectonic regions of the pulvinar has a distinctive pattern of cortical connections and that one of these divisions is further divided into two regions with different patterns of connections. Two of the pulvinar nuclei have similar retinotopic patterns of projections to caudal visual cortex. The large central nucleus of the pulvinar (Pc) projects to the first and second visual areas, V1 and V2, and an adjoining temporal dorsal area (TD) in retinotopic patterns indicating that the upper visual quadrant is represented dorsal to the lower quadrant in Pc. The smaller ventral nucleus (Pv) which stains darkly for the Cat‐301 antigen, projects to these same cortical areas, with a retinotopic pattern. Pv also projects to a temporal anterior area, TA. The dorsal nucleus (Pd), which densely expresses AChE, projects to posterior and ventral areas of temporal extrastriate cortex, areas TP and TPI. A posterior nucleus, Pp, projects to anterior areas TAL and TI, of the temporal lobe, as well as TPI. Injections in different cortical areas as much as 6 mm apart labeled overlapping zones in Pp and double‐labeled some cells. These results indicate that the visual pulvinar of tree shrews contains at least four functionally distinct subdivisions, or nuclei. In addition, the cortical injections revealed that the LGN projects topographically and densely to V1 and that a significant number of LGN neurons project to V2 and TD. J. Comp. Neurol. 467:607–627, 2003. © 2003 Wiley‐Liss, Inc.
Regionally restricted expression of the transcription factor c‐myc intron 1 binding protein during brain development
Authors: Campbell Daniel B. , Levitt Pat 
Published: November 2003

AbstractTranscription factors regulate proliferation, differentiation, and regionalization of the central nervous system. In a screen of developing cerebral cortex, we identified the transcription factor c‐myc intron 1 binding protein (mibp1) due to its abundant expression. In this study, we analyzed the temporal and spatial expression patterns of mibp1 mRNA in developing mouse brain to address the putative role of this transcription factor in neural differentiation. Northern hybridization studies revealed that mibp1 is expressed first in the mouse dorsal telencephalon at embryonic day (E) 14.5, during peak neuronal production. In situ hybridization experiments revealed that mibp1 expression in the cerebral wall is most abundant in postmitotic cells of the cortical plate and absent from proliferative zones. Moreover, mibp1 is restricted to dorsal telencephalon during embryogenesis with expression only in the cerebral wall, olfactory bulb, and hippocampus. N‐myc, a potential target of mibp1 regulation, exhibited complementary, nonoverlapping expression patterns in the telencephalon with greatest expression in proliferating cells of the ventricular zone from E12.5 to E14.5; N‐myc was absent from the telencephalon by E15.5. The specificity and timing of mibp1 expression in the cerebral cortex suggests a role in maintaining a state of neuronal differentiation in the dorsal telencephalon. J. Comp. Neurol. 467:581–592, 2003. © 2003 Wiley‐Liss, Inc.
Outstanding neuroprotective efficacy of dexrazoxane in mice subjected to sequential common carotid artery sectioning
Authors: Rodriguez Rodolfo , Santiago‐Mejia Jacinto , Fuentes‐Vargas Monica , San‐Juan Eduardo Ramirez 
Published: November 2003

AbstractWe evaluated the efficacy of the iron chelator, dexrazoxane, to reduce the neurological alterations and mortality produced by sequential common carotid artery sectioning (SCAS) in mice. Deferoxamine (32 and 128 mg/kg), dexrazoxane (32 and 128 mg/kg), dizolcipine (0.8 and 3.2 mg/kg), or nimodipine (0.4 and 1.6 mg/kg) were injected ip 15 min after the second artery sectioning. Animals were evaluated at 24, 48, and 72 h after compound or vehicle injection using three procedures: neurological examination, spontaneous locomotor activity, and motor coordination. Based on neurological evaluation, we designed and used a disability status scale (NDSS) to determine the degree of functional incapacity after brain ischemia for each animal. The scale comprises 10 progressive grades or steps beyond 0 (normal), extending to status 10 (death due to SCAS). In this scale, the higher the number, the greater is the neurological dysfunction. For the vehicle‐treated animals, the survival rate ranged from 41 to 30% and the neurological scores ranged from 6.6 to 7.8 between 24 and 72 h after the second surgery. The survival rate was significantly increased with low and high doses of dexrazoxane (ranges, 57–52% and 66–60%, respectively). Total neurological scores with 32 and 128 mg/kg of dexrazoxane (ranges, 4.5–5.4 and 3.3–4.0, respectively) were significantly lower (P<0.05) than its corresponding solvent. Dexrazoxane administration also avoided hypolocomotion and motor incoordination produced by SCAS. None of three known putative neuroprotective agents tested in this study reduced the mortality and/or consistently diminished neurological deficits. We conclude that dexrazoxane has very important neuroprotective properties and that our scale is useful to quantify the degree of neurological impairment after brain ischemia. Drug Dev. Res. 60:294–302, 2003. © 2003 Wiley‐Liss, Inc.
Holocene dust accumulation and the formation of polycyclic cinnamon soils (luvisols) in the Chinese Loess Plateau
Authors: Huang Chun Chang , Pang Jiangli , Chen Shu'e , Zhang Zhanping 
Published: November 2003

AbstractChinese loess–palaeosol sequences are well known for their records of monsoonal climatic variations. However, the modern processes of dust accumulation and soil formation remain poorly understood. A high‐resolution investigation on modern soils, including the measurement of magnetic susceptibility, particle‐size distribution, total Fe, total organic carbon, CaCO3 content, and optical stimulated luminescence (OSL) dating was carried out on the Zhouyuan loess tableland in the southern Loess Plateau. The results indicate that modern cinnamon soils (luvisols) have developed on contemporarily accumulated aeolian dust during the Holocene. The aeolian loess accumulated during the Younger Dryas was identiﬁed in the top part of the Malan Loess that underlay the modern soil by OSL dating and proxy climatic data. It indicates that the Malan Loess accumulated during the last glaciation (marine isotope stages 2–4) does not serve as the parent material for the modern soils. Pedogenesis of the soils started with the increased precipitation and soil moisture that have occurred on the loess tableland since the early Holocene. Precipitation‐driven pedogenesis and organic activities are responsible for the leaching of CaCO3, decomposition of mineral dust and the production of clay and ferromagnetic minerals. Drier intervals have interrupted soil formation several times, and therefore proﬁles with multiple soils have been developed at many sites on the loess tableland. At places where soil erosion was relatively strong, either a single soil or welded soils are preserved in the Holocene proﬁles. This does not necessarily mean, however, that modern soils over the plateau have been developed without interruption under a constantly warmer, moister climate. This is signiﬁcant for understanding the surface processes and climatic variation during the formation of the numerous palaeosols over the Loess Plateau in the Quaternary. Copyright © 2003 John Wiley & Sons, Ltd.
Plasma‐treated, collagen‐anchored polylactone: Its cell affinity evaluation under shear or shear‐free conditions
Authors: Yang Jian , Wan Yuqing , Yang Junlin , Bei Jianzhong , Wang Shenguo 
Published: November 2003

AbstractPoly(L‐lactic acid)(PLLA) and poly(L‐lactic‐co‐glycolic acid) (PLGA) (85/15) were modified by plasma treatment. Then they were collagen anchored (PT/CA), and the cell affinity was evaluated by cell culture under shear or shear‐free conditions. A convenient and “intuitionistic” dyeing method has been proposed for measuring the modified depth when plasma treatment is applied for the treatment of porous scaffolds. A parallel plate flow chamber was developed in order to study the cell affinity of a material under shear stress. Our results show that a porous scaffold can be modified by plasma treatment and that a depth of about 4.0 mm for this modification can be reached with NH3 plasma treatment (50 w, 20 Pa, 5 min). PT/CA modification is an effective surface modification method for facilitating cell transplantation and improving the cell affinity of three‐dimensional porous cell scaffolds in tissue engineering. It can solve the problem of non‐uniform cell distribution in most synthetic porous cell scaffolds. Using the flow chamber system, a series of quantitative data, including cell adherent fraction, cell area, and mean shape, were compared to evaluate the cell affinity of PLLA before and after PT/CA modification. The results indicate that the quality of cell attachment on PT/CA‐modified PLLA apparently is better than that on unmodified PLLA. The flow chamber system potentially may be a tool for evaluating surface modification methods. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 1139–1147, 2003
Biocompatibility and surface structure of chemically modified immunoisolating alginate‐PLL capsules
Authors: Bünger C. M. , Gerlach C. , Freier T. , Schmitz K. P. , Pilz M. , Werner C. , Jonas L. , Schareck W. , Hopt U. T. , de Vos P. 
Published: November 2003

AbstractGrafting of encapsulated living cells has the potential to cure a wide variety of diseases. Large‐scale application of the technique, however, is hampered by insufficient biocompatibility of the capsules. A major factor in the biocompatibility of capsules is inadequate covering of the inflammatory poly‐L‐lysine (PLL) on the capsules' surface. In the present study, we investigate whether tissue responses against alginate‐PLL capsules can be reduced by crosslinking the surface of the capsules with heparin or polyacrylic acid. Our transplant study in rats shows a tissue response composed of fibroblasts and macrophages on alginate‐PLL‐alginate and alginate‐PLL‐heparin capsules that was completely absent on alginate‐PLL‐polyacrylic acid capsules. Atomic force microscopy analyses of the capsules demonstrates that the improved biocompatibility of alginate‐PLL‐capsules by polyacrylic acid coating should not only be explained by a more adequate binding of PLL but also by the induction of a smoother surface. This study shows for the first time that biologic responses against capsules can be successfully deleted by chemically crosslinking biocompatible molecules on the surface of alginate‐PLL capsules. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 1219–1227, 2003
Osteoblast function on nanophase alumina materials: Influence of chemistry, phase, and topography
Authors: Price Rachel L. , Gutwein Luke G. , Kaledin Leonid , Tepper Frederick , Webster Thomas J. 
Published: November 2003

AbstractAlumina is a material that has been used in both dental and orthopedic applications. It is with these uses in mind that osteoblast (bone‐forming cell) function on alumina of varying particulate size, chemistry, and phase was tested in order to determine what formulation might be the most beneficial for bone regeneration. Specifically, in vitro osteoblast adhesion, proliferation, intracellular alkaline phosphatase activity, and calcium deposition was observed on delta‐phase nanospherical, alpha‐phase conventional spherical, and boehmite nanofiber alumina. Results showed for the first time increased osteoblast functions on the nanofiber alumina. Specifically, a 16% increase in osteoblast adhesion over nanophase spherical alumina and a 97% increase over conventional spherical alumina were found for nanofiber alumina after 2 h. A 29% increase in cell number after 5 days and up to a 57% greater amount of calcium was found on the surface of the nanofiber alumina compared with other alumina surfaces. Some of the possible explanations for such enhanced osteoblast behavior on nanofiber alumina may be attributed to chemistry, crystalline phase, and topography. Increased osteoblast function on nanofiber alumina suggests that it may be an ideal material for use in orthopedic and dental applications. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 1284–1293, 2003
Glucose stabilizes collagen sterilized with gamma irradiation
Authors: Ohan Mark P. , Dunn Michael G. 
Published: November 2003

AbstractGamma irradiation sterilization (γ‐irradiation) fragments and denatures collagen, drastically decreasing critical physical properties. Our goal was to maintain strength and stability of γ‐irradiated collagen by adding glucose, which in theory can initiate crosslink formation in collagen during exposure to γ‐irradiation. Collagen films prepared with and without glucose were γ‐irradiated with a standard dose of 2.5 Mrad. Relative amounts of crosslinking and denaturation were approximated based on solubility and the mechanical properties of the films after hydration, heat denaturation, or incubation in enzymes (collagenase and trypsin). After exposure to γ‐irradiation, collagen films containing glucose had significantly higher mechanical properties, greater resistance to enzymatic degradation, and decreased solubility compared with control films. The entire experiment was repeated with a second set of films that were exposed first to ultraviolet irradiation (254 nm) to provide higher initial strength and then γ‐irradiated. Again, films containing glucose had significantly greater mechanical properties and resistance to enzymatic degradation compared with controls. Gel electrophoresis showed that glucose did not prevent peptide fragmentation; therefore, the higher strength and stability in glucose‐incorporated films may be due to glucose‐derived crosslinks. The results of this study suggest that glucose may be a useful additive to stabilize collagenous materials or tissues sterilized by γ‐irradiation. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 1188–1195, 2003
Hydroxyapatite accelerates differentiation and suppresses growth of MC3T3‐E1 osteoblasts
Authors: Shu R. , McMullen R. , Baumann M. J. , McCabe L. R. 
Published: November 2003

AbstractHydroxyapatite describes both the natural mineral phase of bone as well as the widely used calcium–phosphate implant substitute. Given that hydroxyapatite is a major component of the in vivo surface with which osteoblasts interact, it is surprising that most studies examining the regulation of osteoblast growth and differentiation utilize plastic surfaces. Here we demonstrate that the phenotype of mouse MC3T3‐E1 osteoblasts is significantly altered on hydroxyapatite compared with plastic surfaces. Specifically, alkaline phosphatase activity and messenger RNA levels, markers of early stages of osteoblast differentiation, are increased in osteoblasts cultured on hydroxyapatite. The precocious appearance of alkaline phosphatase activity on the hydroxyapatite surface suggests that osteoblast differentiation is activated earlier compared with plastic surfaces. Osteocalcin expression, a marker of late‐stage differentiation, is also increased on hydroxyapatite and further demonstrates enhanced differentiation. Cell counts indicate that fewer osteoblasts are present on hydroxyapatite versus plastic surfaces 24 h after plating. Measurement of osteoblast attachment, apoptosis, and necrosis indicated no differences between surfaces. In contrast, the number of bromodeoxyuridine‐incorporating cells was significantly decreased on hydroxyapatite compared with plastic surfaces. Taken together, our findings indicate that hydroxyapatite enhances osteoblast differentiation while also suppressing growth. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 1196–1204, 2003
Fibrous encapsulation of single polymer microfibers depends on their vertical dimension in subcutaneous tissue
Authors: Sanders J. E. , Rochefort J. R. 
Published: November 2003

AbstractThe purpose of this research was to investigate possible explanations for why small‐diameter microfiber implants do not experience encapsulation in subcutaneous tissue as do large‐diameter fiber implants. Single polypropylene microfibers of approximately rectangular cross‐section with rounded edges were twisted about their longitudinal axes and affixed at their ends to polycarbonate frames. The frames were implanted in rat subcutaneous dorsum for a 5‐week period, then removed and processed for light microscopy analysis. Fibrous capsule presence/absence and thickness around the implants were assessed, and their relationships to geometric features of the fibers investigated. A logistic regression analysis between presence/absence of a fibrous capsule and geometric features of interest demonstrated strong predictive ability (92.4% correct predictions) for implant height and a well‐defined threshold separating the presence and absence of a fibrous capsule at 5.9 μm (p < 0.001). Implant height was defined as the vertical distance between the most superficial and deepest level of the implant. This 5.9‐μm threshold value of implant height is comparable to the 6.0‐μm diameter threshold for capsule presence/absence in fibers of circular cross‐section [Sanders et al. J Biomed Mater Res 2000; 52(1):231–237]. Fiber major axis length, minor axis length, aspect ratio, surface area per unit length, implant width, and implant angle did not show similar predictive ability or a well‐defined threshold separating the presence and absence of a fibrous capsule. It is reasoned that for fibers greater than the threshold height of 5.9 μm, separation of collagen fibers in the extracellular matrix creates dead space regions adjacent to the fibers that attract inflammatory cells and stimulate fibrous capsule formation. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 1181–1187, 2003
Intermittent versus continuous stretching effects on osteoblast‐like cells in vitro
Authors: Winter L. C. , Walboomers X. F. , Bumgardner J. D. , Jansen J. A. 
Published: November 2003

AbstractThe objective of this study was to quantify and compare stretch‐mediated responses of primary rat osteoblast‐like cells to uniform cyclic strain applied intermittently or continuously. Primary rat osteoblast‐like cells were seeded and cultured in silicone rubber dishes for 2 days. They were then subjected to 1000 microstrains at 1 Hz for periods of 60 consecutive minutes or to a series of 15‐min stretch followed by 15‐min rest, until a total stretch of 60 min. After stretching, cells were incubated and assayed on days 4, 8, 16, and 24 for DNA content, alkaline phosphatase (ALP) activity, and calcium (Ca) content. Additionally, qualitative information was obtained via scanning electron and confocal laser scanning micrographs. Significant increases in DNA were observed for cells stretched intermittently versus cells stretched continuously and versus controls. Results showed significant decreases (p < 0.05) in ALP for cells between stretched groups and between both stretched groups versus controls. Additionally, Ca content was greater in cells stretched intermittently versus controls on days 4 and 8 and versus cells stretched continuously on day 24. In conclusion, intermittently strained cells demonstrated significant decreases in ALP and increases in DNA and Ca versus cells strained continuously. This supports the theory that cells respond to mechanical loading in a “trigger‐like” response. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 1269–1275, 2003