bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interleukin‐13 and ‐4 induce death of activated microglia
Authors: Yang Myung‐Soon , Park Eun Jung , Sohn Seonghyang , Kwon Hyuk Jae , Shin Won‐Ho , Pyo Han Kyung , Jin Byungkwan , Choi Kyeong Sook , Jou Ilo , Joe Eun‐Hye 
Published: October 2004

AbstractWhen the brain suffers injury, microglia migrate to the damaged sites and become activated. These activated microglia are not detected several days later and the mechanisms underlying their disappearance are not well characterized. In this study, we demonstrate that interleukin (IL)‐13, an anti‐inflammatory cytokine, selectively induces cell death of activated microglia in vitro. Cell death was detected 4 days after the coaddition of IL‐13 with any one of the microglial activators, lipopolysaccharide (LPS), ganglioside, or thrombin. This cell death occurred in a time‐dependent manner. LPS, ganglioside, thrombin, or IL‐13 alone did not induce cell death. Among anti‐inflammatory cytokines, IL‐4 mimicked the effect of IL‐13, while TGF‐β did not. Cells treated with IL‐13 plus LPS, or IL‐13 plus ganglioside, showed the characteristics of apoptosis when analyzed by electron microscopy and terminal deoxynucleotidyl transferase‐mediated dUTP nick end labeling staining. Electron micrographs also showed microglia engulfing neighboring dead cells. We propose that IL‐13 and IL‐4 induce death of activated microglia, and that this process is important for prevention of chronic inflammation that can cause tissue damage. GLIA 38:273–280, 2002. © 2002 Wiley‐Liss, Inc.
Platelet‐derived growth factor‐b expression induced after rat peripheral nerve injuries
Authors: Oya Takeshi , Zhao Ying‐Luan , Takagawa Kiyoshi , Kawaguchi Makoto , Shirakawa Kamon , Yamauchi Tadakazu , Sasahara Masakiyo 
Published: October 2004

AbstractSchwann cells are crucially important for peripheral nerve regeneration. These cells synthesize several factors that are supposed to enhance axonal regeneration when injured. Platelet‐derived growth factor (PDGF) B‐chain and its β‐receptor are expressed in Schwann cells in both normal peripheral nerves and culture. To elucidate the role of PDGF‐B in peripheral nerve regeneration, we investigated its expression in cut or crush‐injured rat sciatic nerves for up to 28 days. Northern blotting identified substantial increase of PDGF B‐chain transcripts in injured nerves. Immunohistochemistry demonstrated that protein products of the transcripts were augmented at the distal tip of swollen axons in proximal nerve segments and in regenerating axons. Soon after both types of injury, considerable amounts of PDGF‐B accumulated in numerous Schwann cells in distal segments of both models. With restoration of the axon–Schwann cell relationship in the crush model, levels of PDGF‐B tended to decrease, eventually returning to normal. In the cut model in which the relationship cannot be restored, the PDGF‐B was depleted to a very low level. The spatiotemporal correlation between PDGF‐B and cell proliferation was very close throughout the study. These results differed strikingly from those of our previous study of rat optic nerve transection, in which PDGF‐B was expressed only in a few recruited macrophages and glial cells. Augmented PDGF‐B expression after sciatic nerve injury might contribute to peripheral nerve regeneration because PDGF‐B is a mitogen and survival factor for Schwann cells and because it has trophic activity on neurons. GLIA 38:303–312, 2002. © 2002 Wiley‐Liss, Inc.
Exact multivariate tests for brain imaging data
Authors: Almeida Rita , Ledberg Anders 
Published: October 2004

AbstractIn positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) data sets, the number of variables is larger than the number of observations. This fact makes application of multivariate linear model analysis difficult, except if a reduction of the data matrix dimension is performed prior to the analysis. The reduced data set, however, will in general not be normally distributed and therefore, the usual multivariate tests will not be necessarily applicable. This problem has not been adequately discussed in the literature concerning multivariate linear analysis of brain imaging data. No theoretical foundation has been given to support that the null distributions of the tests are as claimed. Our study addresses this issue by introducing a method of constructing test statistics that follow the same distributions as when the data matrix is normally distributed. The method is based on the invariance of certain tests over a large class of distributions of the data matrix. This implies that the method is very general and can be applied for different reductions of the data matrix. As an illustration we apply a test statistic constructed by the method now presented to test a multivariate hypothesis on a PET data set. The test rejects the null hypothesis of no significant differences in measured brain activity between two conditions. The effect responsible for the rejection of the hypothesis is characterized using canonical variate analysis (CVA) and compared with the result obtained by using univariate regression analysis for each voxel and statistical inference based on size of activations. The results obtained from CVA and the univariate method are similar. Hum. Brain Mapping 16:24–35, 2002. © 2002 Wiley‐Liss, Inc.
Carcinoma of the supraglottic larynx: Treatment results with radiotherapy alone or with planned neck dissection
Authors: Hinerman Russell W. , Mendenhall William M. , Amdur Robert J. , Stringer Scott P. , Villaret Douglas B. , Robbins K. Thomas 
Published: October 2004

AbstractPurposeTo present the results of radiotherapy with or without neck dissection for squamous cell carcinoma of the supraglottic larynx treated at the University of Florida and to compare these data with those obtained after conservation surgery.Methods and MaterialsContinuous‐course radiotherapy alone or combined with a planned neck dissection was used to treat 274 patients with squamous cell carcinoma of the supraglottic larynx between 1964 and 1998. All patients had follow‐up for a minimum of 2 years, and 250 (91%) had follow‐up for 5 years or more.ResultsAt 5 years, the actuarial probability of local control after radiotherapy according to T stage was as follows: T1, 100%; T2, 86%; T3, 62%; and T4, 62%. The probability of cause‐specific survival at 5 years by AJCC stage was as follows: stage I, 100%; II, 93%; III, 81% IVA, 50%; and IVB, 13%. The risk of severe late complications was 4%. Of 57 patients undergoing planned postradiotherapy neck dissection, 7% experienced a severe complication.ConclusionsOn the basis of our data and the literature, early or moderately advanced supraglottic carcinomas may be treated successfully with either supraglottic laryngectomy or radiotherapy. Supraglottic laryngectomy probably produces a higher initial local control rate but, based on anatomic and coexisting medical constraints, is suitable for a smaller subset of patients and has a higher risk of complications compared with radiotherapy. © 2002 Wiley Periodicals, Inc.
Anaerobic thyroid abscess from a thyroid cyst after fine‐needle aspiration
Authors: Sun Jui‐Hung , Chang Hung‐Yu , Chen Kwang‐Wen , Lin Koan‐Day , Lin Jen‐Der , Hsueh Chuen 
Published: October 2004

AbstractBackgroundAnaerobic abscess formation within a thyroid cyst is rare but still possible, although aerobic thyroid abscess formation in the thyroid gland after fine‐needle aspiration (FNA) has been observed in immunocompromised patients.MethodsThis study describes the clinical manifestations, thyroid echography, cytologic finding, culture outcome, and treatment course of an anaerobic abscess formation within a thyroid cyst after FNA in a healthy subject.ResultsA 53‐year‐old male subject had rapid enlargement of a left thyroid cyst develop after second FNA. Frank pus was obtained through third FNA. The culture outcome was Propionibacterium acnes, which was rich in saliva and one of the pathogens causing periodontitis and gingivitis. After adequate antimicrobial therapy, the abscess gradually diminished.ConclusionsThis article reported, for the first time, on the formation of an anaerobic thyroid abscess after FNA in a healthy subject. We recommended careful aseptic procedure and adequate isolation processes, such as wearing a mask to avoid an unfavorable outcome as a result of a bacterial infection. © 2002 John Wiley & Sons, Inc. Head Neck 24: 84–86, 2002.
Effect of perforations in burr hole covers on cranial bone regeneration in rabbits
Authors: Leiggener Christoph S. , Curtis Raymond , Pfluger Dominik , Rahn Berton A. 
Published: October 2004

AbstractThe reconstruction of bone defects is a significant problem in cranio‐maxillofacial surgery. In an effort to avoid the known disadvantages of autogenous bone grafting, alternatives have been investigated. Bone substitute materials, degradable or nondegradable, aim at facilitating bone regeneration, while they take over load‐bearing functions for a period of time. In this study, the healing of cranial defects in rabbits was assessed using polylactide guiding covers with and without perforations. Bilateral circular cranial defects were produced in 16 New Zealand white rabbits. The defects were covered with extruded and laser cut polylactide burr hole covers, each animal receiving a perforated burr hole cover on one side and a nonperforated one on the contralateral side. Bone seeking fluorochromes were administered at regular intervals. After an observation period of 8 weeks the amount of bone regeneration in the area of the defects was quantified from contact radiographs, and the dynamics of bone formation were assessed by fluorescence microscopy. Stained sections were used to analyze morphologic differences. No signs of adverse tissue reactions or osteolysis were observed. A bone‐guiding function was observed for both covers with or without perforations. Intracranial tissue herniation into the defect hindered the regeneration process. Wide intraindividual and interindividual variation became apparent and average defect filling was only 40% within the 8‐week observation period. In this model the perforated covers offered no advantage over nonperforated covers. It can be concluded from this study, that the use of external burr hole covers alone does not guarantee a full thickness regeneration of the cranial defect, but it provides a guiding function for promotion of structured bone regeneration. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 61: 131–137, 2002
In vitro and in vivo dissolution behavior of a dysprosium lithium borate glass designed for the radiation synovectomy treatment of rheumatoid arthritis
Authors: Conzone Samuel D. , Brown Roger F. , Day Delbert E. , Ehrhardt Gary J. 
Published: October 2004

AbstractDysprosium lithium borate (DyLB) glass microspheres were investigated for use in the radiation synovectomy treatment of rheumatoid arthritis. In vitro testing focused on weight loss and cation dissolution from glass microspheres immersed in simulated synovial fluid (SSF) at 37°C for up to 64 days. In vivo testing was performed by injecting glass microspheres into the stifle joints of Sprague‐Dawley rats and monitoring the biodegradability of the microspheres and the tissue response within the joints. The DyLB microspheres reacted nonuniformly in SSF with the majority of lithium and boron being dissolved, whereas nearly all of the dysprosium (>99.7%) remained in the reacted microspheres. Because the DyLB glasses released negligible amounts of dysprosium while reacting with SSF, they are considered safe for radiation synovectomy from the standpoint of unwanted radiation release from the joint capsule. Furthermore, the DyLB microspheres fragmented, degraded, and reacted with body fluids while in the joints of rats without histologic evidence of joint damage. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 60: 260–268, 2002; DOI 10.1002/jbm.10047
Resorbability and solubility of zinc‐containing tricalcium phosphate
Authors: Ito Atsuo , Kawamura Haruo , Miyakawa Shunpei , Layrolle Pierre , Kanzaki Noriko , Treboux Gabin , Onuma Kazuo , Tsutsumi Sadao 
Published: October 2004

AbstractUsing zinc‐containing tricalcium phosphate (ZnTCP) as the zinc carrier for zinc‐releasing calcium phosphate ceramic implants promoted bone formation around the implants. Because no quantitative information was available on the equilibrium solubility and resorbability of ZnTCP,in vitroequilibrium solubility andin vivoresorbability of ZnTCP were determined and compared quantitatively in this study. The solubility of ZnTCP decreased with increasing zinc content. The negative logarithm of the solubility product (Ksp) of ZnTCP was expressed as pKsp= 28.686 + 1.7414C− 0.42239C2+ 0.063911C3− 0.0051037C4+ 0.0001595C5in air, whereCis the zinc content in ZnTCP (mol %). The solubility of ZnTCP containing a nontoxic level of zinc (<0.63 wt %) decreased to 52–92% of the solubility of pure tricalcium phosphate (TCP) in the pH range 5.0–7.4. However, thein vivoresorbed volume of ZnTCP containing the same amount of zinc was much lower than that expected from thein vitrosolubility, becoming as low as 26–20% of that of TCP. Cellular resorption of TCP is substantially a process of dissolution in a fluid with an acidic pH that is maintained by the activities of cells. Therefore, the reduction of the resorbability of ZnTCP could be attributable principally to its lowered cellular activation property relative to that associated with pure TCP. © 2002 John Wiley & Sons, Inc. J Biomed Mater Res 60: 224–231, 2002; DOI 10.1002/jbm.10068
Degradation characteristics of α and β tri‐calcium‐phosphate (TCP) in minipigs
Authors: Wiltfang J. , Merten H. A. , Schlegel K. A. , Schultze‐Mosgau S. , Kloss F. R. , Rupprecht S. , Kessler P. 
Published: October 2004

AbstractIn seven Goettingen minipigs 3.5–4.7‐ml cancellous bone defects were created in the area of the tibial head on both sides. The defects were filled with α‐TCP or β‐TCP (tricalciumphosphate). ITI implants (Straumann, Freiburg, Germany) of 3.2 × 12‐mm length were inserted into the underlying ceramic substitutes. Two additional pigs were used as control. Within the periods of observation (4, 16, 20, 28, 46, 68, and 86 weeks) fluorescent dyes were applied. Nondecalcified thin‐sliced sections were examined by means of light and fluorescence microscopy. In addition microangiography and microradiography were performed. Bony regeneration occurred basally and on the sides of the defect according the angiogenetic reossification pattern. Resorption was due to a hydrolytic and cellular degradation process. After 46 weeks histomorphological evaluation showed an incomplete osseointegration of the simultaneously implanted dental implants. The bone contact surface ratio was lower than 25%. After 86 weeks 95–97% of both α‐ and β‐TCP were resorbed. Ceramic residuals stayed within the newly formed trabeculae thus resisting further degradation until remodeling occurred. Both α‐ and β‐TCP show a comparable degradation process. At the 86‐week postoperative point only small residuals of the ceramic can be found. These residuals stay within the newly formed trabeculae, which show a functional orientation. In comparison control defects showed only sparse reossification. The β‐TCP material shows an accelerated degradation mode and has an optimal reactivity with the surrounding tissues. According to the results of this animal experiment both materials can be classified as bone‐rebuilding materials. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 115–121, 2002; DOI 10.1002/jbm.10084
Fixation strength of tapered versus bicylindrical hydroxyapatite‐coated external fixation pins: An animal study
Authors: Moroni Antonio , Faldini Cesare , Pegreffi Francesco , Giannini Sandro 
Published: October 2004

AbstractThe purpose of this study was to comparatively measure the bone–pin interface strength in two types of hydroxyapatite‐coated pins that differed in shape, diameter, and implantation technique. Both pin types are commonly used for tibia fixation. Thirty bicylindrical 5/4‐mm stainless‐steel pins (Group A) and 30 tapered 6/5‐mm stainless‐steel pins (Group B) were implanted in the left tibiae of 10 adult sheep. A monolateral fixator was mounted on the pins after implantation. A 5‐mm‐long bone segment was removed from the tibial mid‐diaphysis to ensure high load at the bone–pin interface. Pin insertion torque was 830 ± 446 N/mm in Group A and 3415 ± 743 N/mm in Group B (p<0.0001, one‐way ANOVA). Six weeks after surgery, the sheep were euthanized and pin extraction torque measured. Pin extraction torque was 1237 ± 499 N/mm in Group A and 3367 ± 1512 N/mm in Group B (p<0.0001, Mann‐Whitney test). Morphological analysis performed at 60× magnification showed a direct bone–pin contact in both groups. Despite challenging biomechanical conditions, this study showed both pin types to be well‐fixed and osteointegrated. Therefore, both pin types are recommended for tibial fixation. However, the tapered pins showed higher extraction torque, an important result for external fixation treatments. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 61–64, 2002
Characterization of damage modes in dental ceramic bilayer structures
Authors: Deng Yan , Lawn Brian R. , Lloyd Isabel K. 
Published: October 2004

AbstractResults of contact tests using spherical indenters on flat ceramic coating layers bonded to compliant substrates are reported for selected dental ceramics. Critical loads to produce various damage modes, cone cracking, and quasiplasticity at the top surfaces and radial cracking at the lower (inner) surfaces are measured as a function of ceramic‐layer thickness. It is proposed that these damage modes, especially radial cracking, are directly relevant to the failure of all‐ceramic dental crowns. The critical load data are analyzed with the use of explicit fracture‐mechanics relations, expressible in terms of routinely measurable material parameters (elastic modulus, strength, toughness, hardness) and essential geometrical variables (layer thickness, contact radius). The utility of such analyses in the design of ceramic/substrate bilayer systems for optimal resistance to lifetime‐threatening damage is discussed. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 137–145, 2002; DOI 10.1002/jbm.10091
Characterization of new acrylic bone cements prepared with oleic acid derivatives
Authors: Vázquez Blanca , Deb Sanjukta , Bonfield William , Román Julio San 
Published: October 2004

AbstractAcrylic bone‐cement formulations were prepared with the use of a new tertiary aromatic amine derived from oleic acid, and also by incorporating an acrylic monomer derived from the same acid with the aim of reducing the leaching of toxic residuals and improving mechanical properties. 4‐N,N dimethylaminobenzyl oleate (DMAO) was used as an activator in the benzoyl‐peroxide radical cold curing of polymethyl methacrylate. Cements that contained DMAO exhibited much lower polymerization exotherm values, ranging between 55 and 62 °C, with a setting time around 16–17 min, depending on the amine/BPO molar ratio of the formulation. On curing a commercial bone cement, Palacos® R with DMAO, a decrease of 20 °C in peak temperature and an increase in setting time of 7 min were obtained, the curing parameters remaining well within limits permitted by the standards. In a second stage, partial substitution of MMA by oleyloxyethyl methacrylate (OMA) in the acrylic formulations was performed, the polymerization being initiated with the DMAO/BPO redox system. These formulations exhibited longer setting times and lower peak temperatures with respect to those based on PMMA. The glass transition temperature of the experimental cements were lower than that of PMMA cement because of the presence of long aliphatic chains of both activator and monomer in the cement matrix. Number average molecular weights of the cured cements were in the range of 1.2×105. PMMA cements cured with DMAO/BPO revealed a significant (p<0.001) increase in the strain to failure and a significant (p<0.001) decrease in Young's modulus in comparison to Palacos® R, whereas ultimate tensile strength remained unchanged. When the monomer OMA was incorporated, low concentrations of OMA provided a significant increase in tensile strength and elastic modulus without impairing the strain to failure. The results demonstrate that the experimental cements based on DMAO and OMA have excellent promise for use as orthopaedic and/or dental grouting materials. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 88–97, 2002; DOI 10.1002/jbm.10092
Deposition of 90YPO4 and 144CePO4 radioisotopes on polymer surfaces for radiation delivery devices
Authors: Qu Xin , Weinberger Judah 
Published: October 2004

AbstractIntravascular irradiation with β emitters inhibits restenosis in arteries after balloon angioplasty or stent implantation. Yttrium‐90 (90Y, T1/2=64 h) and cerium‐144 (144Ce, T1/2=286 d) emit beta particles (Emax=2.28–3.50 MeV) having an ideal energy range for brachytherapy delivery system. In this article, a previously reported method for depositing 32P on poly(ethylene terephtalate) (PET) surfaces is generalized and modifications that allow deposition of other β‐emitting radioisotopes, such as 90Y and 144Ce, are demonstrated. PET films were first coated with chitosan hydrogel and then adsorbed different amounts of phosphoric acid (PA) in aqueous solutions. Yttrium was deposited onto the surface as YPO4 after the films were immersed in YCl3 solutions. 1 μCi 90YCl3 (2×10−9 g) was used in each sample as a tracer for measuring the deposition efficiency, which is defined as the percentage of YCl3 deposited on the surface compared to the amount of YCl3 in solutions before the deposition. In order to improve the safety of brachytherapy treatments, polyurethanes were used to seal the deposited radioisotopes on the surface to minimize the leakage of the isotopes into the patients. The generality of this method presented here for a wide variety of particular radioisotopic components allows design of a broad range of versatile radioisotope sources. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 98–105, 2002; DOI 10.1002/jbm.10095
The effect of processing conditions on the properties of poly(methyl methacrylate) fibers
Authors: Wright Debra D. , Lautenschlager Eugene P. , Gilbert Jeremy L. 
Published: October 2004

AbstractBrittle failure of bone cement remains a problem for the long‐term stability of hip prostheses. Fibers have been developed from poly(methyl methacrylate) (PMMA) that retain the chemistry of bone cement, but improve the mechanical properties greatly. To fabricate the fibers, a polymer melt is extruded out of a small die (spinneret) and pulled onto a take‐up wheel. Varying the speed of extrusion and temperature of the melt can control the viscosity of the molten polymer. This study examines the effect of melt viscosity on the resultant properties of fibers fabricated from PMMA. The goals are to optimize fiber processing and determine processing‐structure–property relationships. Resultant fibers had moderate to high levels of retained molecular orientation, and ultimate tensile strengths (UTS) ranging from 60 to 225 MPa, moduli from 1.5 to 3.5 GPa, and strain to failure from 10 to 40%. Fibers fabricated at a constant viscosity and draw velocity had identical properties, whereas decreasing the viscosity generally increased the mechanical properties and retained orientation. Linear regression models were constructed to predict how the processing variables affect the structure (orientation) of the fiber and how the structure affects the UTS. This can be used to design efficient processing methods for PMMA fibers. © 2002 John Wiley & Sons, Inc. J Biomed Mater Res (Appl Biomater) 63: 152–160, 2002