bluuebunny/crossref_metadata_2025 huggingface dataset:
Polyurethane–poly(methyl methacrylate) block copolymer dispersions through polyurethane macroiniferters
Authors: Kim Byung Kyu , Lee Jeong Sam , Lee Mun Cheul , Yoon Koo Sik
Published: March 2003

Polyurethane macroiniferter/poly(methyl methacrylate) block copolymer dispersions with inverse core‐shell morphologies were obtained from 1,1,2,2,‐tetraphenylethane‐1,2‐diol, dimethylol propionic acid, 4,4′‐diphenylmethane diisocyanate, and poly(propylene glycol) via a living radical mechanism. Molecular weight, particle size and dispersion viscosity, and thermal, mechanical, and dynamic mechanical properties of the dispersion cast films are reported as a function of copolymerization time. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1971–1975, 2003
Studies on the conductivity properties of a family of cyanoethylated amine cured epoxy resin matrices
Authors: Banerjee M. , Mukherjee G. S.
Published: March 2003

A group of epoxy matrices having a varied amount of crosslink densities have been prepared by curing diglycidyl ether of bisphenol A (DGEBA)–epoxy resin with the help of a family of cyanoethylated amine hardeners based on the adducts of 1 mole of triethylenetetramine and x moles of acrylonitrile, where x = 1, 2, and 3, to effect increasing level of cyanoethylation of triethylenetetramine. The electrical conductivities of such epoxy matrices having increasing crosslink densities were evaluated by a two‐probe a.c. technique in the frequency range of 100 Hz to 13 MHz using an impedance analyzer in the temperature range from 299 to 495 K. It was observed that the conductivity increased with an increased level of cyanoethyl (CH2CH2CN) moiety in the matrix resin, while the activation energy (Ec) of conductivity in the elastomeric region above Te generally showed a reversed trend with respect to Ev from 1.11 to 0.83 eV, where Te is defined by Te = (Tg + ΔT), the 〈ΔT 〉 for this family of matrix resin being 44.83°C. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1627–1631, 2003
Synthesis of multiblock copolymers of poly(2‐vinylpyridine) and polyoxyethylene
Authors: Wang Chaoyang , Cui Minhui
Published: March 2003

Telechelic dihydroxy poly(2‐vinylpyridine) (THPVP) samples with different molecular weights were synthesized by using lithium α‐methylnaphthalene as an anionic initiator in mixed solvents of benzene and tetrahydrofuran (THF). Then multiblock copolymers of poly(2‐vinylpyridine) (P2VP) and polyoxyethylene (PEO) were obtained by condensing THPVP and PEO with dichloromethane in the presence of potassium hydroxide. The effects of reaction time, molecular weight of PEO and THPVP, and raw meal ratio PEO/THPVP (w/w) were investigated. The best conditions were found. The copolymers can be purified by water and toluene. The purified copolymers were characterized by infrared (IR) and 1H nuclear magnetic resonance (1H‐NMR). The PEO segment content was calculated from the integral curve of 1H‐NMR spectra. The results showed that these multiblock copolymers were connected through oxymethylene. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1632–1636, 2003
Influence of the preparation on the mechanical, thermal, and gas permeation properties of polypropylene/oligopinene thin films
Authors: Mendes Luis C. , Miranda Fernanda C. , Ferreira Anderson F. , Dias Fabiano M. , F. Garcia M. Elizabeth
Published: March 2003

The mechanical, thermal, and gas permeation properties of polypropylene (PP)/oligopinene systems in the form of compression thin films 10 μm thick, which were prepared by quenching (with liquid nitrogen) and slow‐cooling (15°C/min) techniques, were examined. The addition of oligopinene to PP changed the stress–strain curve of the polyolefin. Both for quenching and slow‐cooling films, with a higher oligomer content, no more yielding was observed, and the elongation at break abruptly decreased with greater than 10% oligomer. The elastic modulus and stress at break changed according to the thermal conditions of the film preparation. Thermal analysis revealed that the blend system had two glass‐transition temperatures for both types of films. The values of permeation to CO2were independent of the film preparation and were practically unchangeable with the oligomer content in the blends, indicating that the overall decrease in the crystallinity was counterbalanced by the rigidity of the two amorphous phases. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2253–2260, 2003
Interface development and encapsulation in simultaneous coinjection molding of disk. II. Two‐dimensional simulation and experiment
Authors: Li C. T. , Lee D. J. , Isayev A. I.
Published: March 2003

Two‐dimensional simulation and experimental studies of flow‐rate‐controlled coinjection molding were carried out. Skin polymer was injected first, and then both skin and core polymers were injected simultaneously into a center‐gated disk cavity through a two‐channel nozzle to obtain an encapsulated sandwich structure. The physical modeling and simulation developed, reported in Part I of this series, were based on the Hele–Shaw approximation and the kinematics of the interface to describe the multilayer flow, and the interface development was used to predict the skin/core distribution in the moldings. The effects of rheological properties and processing conditions on the material distribution, penetration behavior, and breakthrough phenomena were investigated. The predicted and measured results were found to be in a good agreement. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2310–2318, 2003
Organic–inorganic polymer hybrids and porous materials obtained on their basis
Authors: Cazacu Maria , Dragan Stela , Vlad Angelica
Published: March 2003

Tetramethoxysilane (TMOS) or tetraethoxysilane (TEOS), an organic monomer [methylmethacrylate (MMA) or styrene (St)] and either α‐propylmethacryloxy‐ω‐trimethylsiloxy‐oligo(dimethylsiloxane) (OMS), as a compatibilizing agent, or α,ω‐bis(vinyl) oligo(dimethylsiloxane) (OVS), as compatibilizing and crosslinking agent, were allowed to undergo a sol–gel reaction under acidic condition and in the presence of 2,2′‐azoisobutyronitrile (AIBN) as a free‐radical initiator. The hydrolysis‐condensation and in situ free‐radical polymerization occur independently, to give a hybrid consisting of both inorganic and organic components. The conversion of the monomers to the proper polymers was monitored by IR spectroscopy and TGA. The resistance of the organic polymers to solvent extraction was also studied. The hybrids were pyrolyzed in an oxidative atmosphere. By decomposition, the organic polymer generated pores in the inorganic matrix. A quantitative evaluation of the characteristics for the resulting porous material was made by determination of the specific area, pore volume, and average radius. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2060–2067, 2003
Preparation of novel gold‐coated syndiotactic poly(vinyl alcohol) microfibrils by sputtering
Authors: Do Ghim Han , Pil Kim Jae , Ho Kim Joon , Koo Kang , Soo Kim Sam , Seok Lyoo Won
Published: March 2003

To prepare a syndiotactic poly(vinyl alcohol) (PVA)/gold complex for various biomedical applications, ultrahigh‐molecular‐weight syndiotactic PVA microfibrils were directly prepared by the saponification of poly(vinyl pivalate) that was obtained through bulk polymerization of vinyl pivalate at 30°C. PVA microfibrils with a number‐average degree of polymerization, syndiotactic diad content, and degree of saponification of 14,300, 61.7%, and 99.9%, respectively, were gold‐coated by sputtering at 140 and 150 W (Watt) for 1, 2, and 3 min, respectively. A weight gain of up to 7% by the gold atoms for the PVA microfibrils treated at 150 W for 3 min was found. Morphological changes at the surface were observed by a microscopic method. A mechanism of gold coating on PVA microfibrils is suggested. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2369–2372, 2003
Silicone elastomers for electronic applications. I. Analyses of the noncrosslinked fractions
Authors: Andersson L. H. U. , Hjertberg T.
Published: March 2003

In a study about silicone contamination on surfaces, crosslinked polydimethylsiloxanes have been examined focusing on the curing process and the noncrosslinked part in the bulk of the material. Curing was studied by following the development of gel as a function of curing time and temperature using Soxhlet extraction and differential scanning calorimetry (DSC) measurements. Gas chromatography–mass spectroscopy (GC‐MS), size exclusion chromatography (SEC), and thermogravimetric analysis (TGA) analyses gave information about the composition and size of the noncrosslinked fraction. The experiments demonstrate that the curing kinetics are of Arrhenius type with a strong temperature dependence. Interestingly, we find that 5–20% of the material does not undergo crosslinking reactions, although only 0–1% of the total sample mass is volatile at ambient temperature and pressure. It is likely that the volatile components mainly give rise to problems when they are confined to closed compartments or when they are in direct contact with a cold surface so that condensation on the surface occurs. Most likely, surface contamination originates from the nonvolatile fraction of the noncrosslinked portion of the material. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2073–2081, 2003
The nutrient status of the agriculturally impacted Gamtoos Estuary, South Africa, with special reference to the river‐estuarine interface region (REI)
Authors: Scharler U.M. , Baird D.
Published: March 2003

Ecological water reserves are part of the new water management philosophy in South Africa. The estuaries are threatened by excessive water abstraction from their rivers and the consequent reduction in freshwater input. This study was conducted to further improve our understanding of freshwater requirements in terms of nutrients for South African estuaries.

The Gamtoos Estuary was sampled between November 1996 and November 1998 to determine its nutrient status and freshwater input rates. Furthermore, the possible existence of a distinct river‐estuarine interface (REI) in terms of nutrients has been investigated. Nutrients analysed included phosphate, nitrate, nitrite, ammonia, dissolved organic nitrogen (DON), dissolved organic carbon (DOC), particulate organic nitrogen (PON) as Kjieldahl nitrogen, total particulate phosphorus and total particulate carbon.

The Gamtoos River was found not to be the ultimate source of nutrients to the estuary, but non‐point sources such as the seepage of fertilisers from adjacent agricultural fields determined to a great extent the nutrient status of the estuary.

Results showed that it was not possible to identify a defined river‐estuarine interface region for all nutrients. Most were measured in higher concentrations in the lower salinity reaches (<17‰) where we observed the combined effect of inputs from the Gamtoos River, an agricultural drainage pipe, and fertilizer seepage from non‐point sources on nutrient concentration.

Prolonged water withdrawal for human use impacts the continuous renewal of the nutrient pool so important to other South African estuaries with relative pristine catchment areas. However, reduced fresh water inputs could enhance eutrophication in polluted estuaries due to a decreased flushing potential of the estuary. In this case the Gamtoos Estuary has a freshwater requirement for freshets and floods to “clean” the estuary of accumulated nutrients and other organic material.

This should be a consideration in further freshwater abstraction policies. Conservation issues arise since the Gamtoos Estuary is one of the few permanently open estuaries along the South African coast and serve in this study as an example and as a first attempt to relate freshwater requirements to nutrient dynamics in a South African context.

Copyright © 2002 John Wiley & Sons, Ltd.
Quantification of serpulid biogenic reef coverage of the sea bed (Polychaeta: Serpulidae) using a video transect technique
Authors: Moore Colin G. , Harries Dan B. , Lyndon Alastair R. , Saunders Graham R. , Conway Terence R.
Published: March 2003

The large size, patchiness and fragility of serpulid reefs present difficulties for the measurement of reef coverage for mapping and monitoring studies. Video transect measures of cover are assessed in terms of accuracy and sensitivity of the method for the identification of spatial or temporal changes.

By comparison with direct in situ measurement of reef cover, it was found that still photography was capable of providing an accurate means for the measurement of the seabed coverage by individual reefs.

By comparison of video and still photographic measurement of reef cover, it was found that video transects were capable of providing cover estimates of sufficient accuracy for conservation purposes, differing from still photographic estimates by 0.3% cover.

Power analysis was employed on replicate video estimates of reef cover in order to determine the degree of replication required to identify different levels of spatial or temporal change in cover using video transects of different lengths. The modest level of replication required to identify changes in coverage as small as 25% of the initial value suggests that the use of video transects offers great potential in monitoring and mapping studies.

Copyright © 2002 John Wiley & Sons, Ltd.
Inhibition of the cardiac α‐actin gene in embryonic cardiac myocytes by dominant‐negative serum response factor
Authors: Zhu Xiaolei , McAllister Donna , Lough John
Published: March 2003

Serum response factor (SRF), a transcription factor ubiquitously involved in the processes of cellular proliferation and differentiation, has been implicated in cardiac and skeletal muscle development because of its strong expression in embryonic muscle lineages, and its necessity for the transcription of transiently transfected muscle genes that contain SRF binding sites. This study was designed to ascertain whether SRF is required for the expression of an endogenous SRF‐dependent gene during differentiation of early embryonic cardiac myocytes by introducing a dominant‐negative SRF construct via retroviral delivery. Although no effect on overt cellular differentiation was detected, semi‐quantitative RT‐PCR revealed that expression of the SRF‐dependent gene cardiac α‐actin was inhibited, whereas expression of the non‐SRF‐dependent genes glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) and cardiac troponin‐C was unaffected. No effect on myocyte proliferation was detected. Curiously, immunohistochemical localization of SRF protein suggested that whereas endogenous SRF was homogeneously dispersed throughout the cytoplasm and nucleus, the dominant‐negative SRF protein was concentrated in the nucleus. These results extend previous findings using transiently transfected genes to the endogenous level, indicating that SRF is required for the full expression of muscle genes that contain SRF binding sites during cardiac myocyte differentiation. Anat Rec Part A 271A:315–321, 2003. © 2003 Wiley‐Liss, Inc.
Frontonasal dysplasia in 3H1 Br/Br mice
Authors: McBratney Brandeis M. , Margaryan Edith , Ma Wenbin , Urban Zsolt , Lozanoff Scott
Published: March 2003

The adult Brachyrrhine (3H1 Br/+) mouse displays severe midfacial retrognathia, with a “pugnose” external appearance, but information concerning craniofacial morphology of the homozygote (3H1 Br/Br) mutant is lacking. This study characterized craniofacial phenotype and genotypic features of the homozygous condition. Segregation analysis was performed by phenotypic scoring of offspring from 3H1 Br/+ reciprocal matings. Whole‐mount staining was undertaken to determine the presence or absence of cranial base structures in newborn and adult mice, while features of cranial base chondrification were examined using light microscopy and type II collagen immunohistochemistry. Karyotype analysis was performed to determine whether gross chromosomal aberrations were present. Finally, microsatellite mapping analysis was undertaken to provide further resolution of the Br locus. Results showed that Br was inherited as an autosomal semidominant feature. 3H1 Br/Br mice consistently lacked a presphenoid (with its lateral projections, including a preoptic root, postoptic root, and lesser wing). Karyotyping did not reveal major gross aberrations; however, microsatellite analysis localized Br to distal mouse chromosome 17 in the vicinity of D17Mit155. These results indicated that 3H1 Br/Br mice show characteristic features of frontonasal dysplasia, including median facial clefting and bifid cranium, as well sphenoidal malformations. Furthermore, this mutant should serve as a useful model for examining mechanisms of frontonasal dysplasia. Anat Rec Part A 271A:291–302, 2003. © 2003 Wiley‐Liss, Inc.
Ultrastructural morphometry of capillary basement membrane thickness in normal and transgenic diabetic mice
Authors: Carlson Edward C. , Audette Janice L. , Veitenheimer Nicole J. , Risan Jessica A. , Laturnus Donna I. , Epstein Paul N.
Published: March 2003

Capillary basement membrane (CBM) thickening is an ultrastructural hallmark in diabetic patients and in animal models of diabetes. However, the wide variety of tissues sampled and diverse methods employed have made the interpretation of thickness data difficult. We showed previously that acellular glomerular BMs in OVE26 transgenic diabetic mice were thickened beyond normal age‐related thickening, and in the current study we hypothesized that other microvascular BMs likewise would show increased widths relative to age‐matched controls. Accordingly, a series of tissues, including skeletal and cardiac muscle, ocular retina and choriod, peripheral nerve, lung, pancreas, and renal glomerulus was collected from 300–350‐day‐old normal and transgenic mice. Transmission electron micrographs of cross sections through capillary walls were prepared, and CBM thickness (CBMT) was determined by the “orthogonal intercept” method. Morphometric analyses showed highly variable transgene‐related BMT increases in the sampled tissues, with glomerular BM showing by far the greatest increase (+87%). Significant thickness increases were also seen in the retina, pulmonary alveolus, and thoracoabdominal diaphragm. BMT increases were not universal; however, most were modestly widened, and those that were thickest in controls generally showed the greatest increase. Although the pathogenesis of diabetes‐related increases in CBM is poorly understood, data in the current study showed that in OVE26 transgenic mice increased BMT was a frequent concomitant of hyperglycemia. Accordingly, it seems likely that hyperglycemia‐induced microvascular damage may be a contributing factor in diabetic BM disease, and that microvessel cellular and extracellular heterogeneity may limit the extent of CBM thickening in diverse tissues. Anat Rec Part A 271A:332–341, 2003. © 2003 Wiley‐Liss, Inc.
Ultrastructure indicative of ion transport in tectal, Deiters, and tunnel cells: Differences between gerbil and chinchilla basal and apical cochlea
Authors: Spicer Samuel S. , Smythe Nancy , Schulte Bradley A.
Published: March 2003

Ultrastructural examination revealed an epithelium of about five tectal cells (TCs) roofing the outer tunnel (OT) in the mid to upper, but not the basal, region of gerbil and chinchilla cochlea. Structures in TCs that are apparently specialized for retrieval of K+ released into tunnel fluid from outer hair cells (OHCs) include surface fimbriae in the gerbil and canalicular reticulum in the chinchilla. A tunnel roof of organelle‐rich TCs appeared to be better equipped for ion resorption than a roof composed of organelle‐poor Hensen cells (HCs). Fimbriae, filopodia, and the cell body of TCs descended to contact the third Deiters cell (DC3) in the gerbil, and the hypertrophied DC3 phalanx rose to contact TCs in the chinchilla, which suggests a solute exchange between TCs and DCs. Previously unrecognized structures that are speculated to provide ATP ligand for cochlear purinoreceptors occurred in the chinchilla DC and gerbil TC. The observation of a microtubule stalk in DCs indicated that they also function in cochlear mechanics. A newly delineated lateral tunnel cell (LTC) intervened between the DC3 and HC in both species. The apicomedial plasmalemma of all DCs fitted closely to the base of OHCs and enveloped afferent nerves. The morphologic specializations reported here provide further support for the proposed transcellular lateral flow route for K+ currents generated by sound exposure and neural activity. The previously demonstrated expansion of Boettcher cells, outer sulcus cell roots, type Il and IV fibrocytes, and apical microvilli on HCs and Claudius cells (CCs) in the base of the cochlea is postulated here to mediate a basal parallel current that could supply the increased K+ transport required for the basally elevated electric potential (EP). Anat Rec Part A 271A:342–359, 2003. © 2003 Wiley‐Liss, Inc.
Ectodysplasin receptor‐mediated signaling is essential for embryonic submandibular salivary gland development
Authors: Jaskoll Tina , Zhou Yan‐Min , Trump Gary , Melnick Michael
Published: March 2003

Hypohidrotic (anhidrotic) ectodermal dysplasia (HED), the most common of the ∼150 described ectodermal dysplasias, is a disorder characterized by abnormal hair, teeth, sweat glands, and salivary glands. Mutations in the EDA (ectodysplasin‐A) and EDAR (ectodysplasin‐A receptor) genes are responsible for X‐linked and autosomal HED, respectively. Abnormal phenotypes similar to HED are seen in Tabby (EdaTa) and downless (Edardl) mutant mice. Although recent studies have focused on the role of Eda/Edar signaling during hair and tooth development, very little is known about its role during embryonic submandibular salivary gland (SMG) development. To this end, we analyzed the SMG phenotypes in Tabby (Ta) and downless (dl) mutant mice and determined that Ta SMGs are hypoplastic, whereas dl SMGs are severely dysplastic. The absence of SMG ducts and acini in dl SMGs suggests that Eda/Edar signaling is essential for lumina formation and glandular histodifferentiation. Our localization of Eda and Edar proteins at sites of lumen and acini formation supports this conclusion. Moreover, the presence of SMGs in both Ta and dl mutant mice, as well as the absence of immunodetectable Eda and Edar protein in Initial Bud and Early Pseudoglandular stage SMGs, indicate that Eda/Edar‐mediated signaling is important for branching morphogenesis and histodifferentiation, but not for initial gland formation. To initially delineate the morphoregulatory role of Eda/Edar‐mediated signaling during embryonic SMG development, we cultured embryonic day 14 SMGs with enhanced or abrogated Eda/Edar signaling. Eda supplementation induced a significant increase in SMG branching, and enhanced activation of NF‐κB. Abrogating Eda/Edar signaling by adding the soluble form of Edar to bind endogenous ligand in embryonic SMGs results in a significant dose‐dependent decrease in branching morphogenesis. Taken together, our results suggest that the Eda/Edar/NF‐κB pathway exerts its effect on SMG epithelial cell proliferation, lumina formation, and histodifferentiation. Anat Rec Part A 271A:322–331, 2003. © 2003 Wiley‐Liss, Inc.
Variability of Broca's area homologue in African great apes: Implications for language evolution
Authors: Sherwood Chet C. , Broadfield Douglas C. , Holloway Ralph L. , Gannon Patrick J. , Hof Patrick R.
Published: March 2003

The cortical circuits subserving neural processing of human language are localized to the inferior frontal operculum and the posterior perisylvian region. Functional language dominance has been related to anatomical asymmetry of Broca's area and the planum temporale. The evolutionary history of these asymmetric patterns, however, remains obscure. Although testing of hypotheses about the evolution of language areas requires comparison to homologous regions in the brains of our closest living relatives, the great apes, to date little is known about normal interindividual variation of these regions in this group. Here we focus on Brodmann's area 44 in African great apes (Pan troglodytes and Gorilla gorilla). This area corresponds to the pars opercularis of the inferior frontal gyrus (IFG), and has been shown to exhibit both gross and cytoarchitectural asymmetries in humans. We calculated frequencies of sulcal variations and mapped the distribution of cytoarchitectural area 44 to determine whether its boundaries occurred at consistent macrostructural landmarks. A considerable amount of variation was found in the distribution of the inferior frontal sulci among great ape brains. The inferior precentral sulcus in particular was often bifurcated, which made it impossible to determine the posterior boundary of the pars opercularis. In addition, the distribution of Brodmann's area 44 showed very little correspondence to surface anatomy. We conclude that gross morphologic patterns do not offer substantive landmarks for the measurement of Brodmann's area 44 in great apes. Whether or not Broca's area homologue of great apes exhibits humanlike asymmetry can only be resolved through further analyses of microstructural components. Anat Rec Part A 271A:276–285, 2003. © 2003 Wiley‐Liss, Inc.
A clinician's view of spinal cord injury
Authors: Harkey H.Louis , White Elbert A. , Tibbs Robert E. , Haines Duane E.
Published: March 2003

The primary cause of spinal cord injury (SCI) is automobile collisions, followed by violence, falls, and injuries in sporting events. The patient is most frequently a young male. Regardless of cause and age, SCI is a potentially catastrophic injury. The unique anatomical relationship of the spinal cord, being enclosed in the dural sac within the bony vertebral column, make it venerable to a wide range of traumatic insults. SCI is classified as complete or incomplete with several subclasses arranged under each of these respective headings. The probability of recovery to a functional state is usually better for patients with incomplete injuries. Treatment for SCI involves initially immobilizing the injured vertebral column, medications to prevent secondary injury, and potential surgery to release pressure on the spinal cord and restore stability to the vertebral column. Postsurgical care is directed toward prevention and treatment of secondary complications of SCI such as respiratory failure, deep venous thrombosis, and decubitus ulcers. Advances in these areas are providing patients with a greater probability of recovery, a longer life, and a better quality of life. Research in the clinical and basic sciences is opening new avenues of hope for the spinal cord injury patient. Anat Rec (Part B: New Anat) 271BB:41–48, 2003. © 2003 Wiley‐Liss, Inc.
Use of a cell line to investigate olfactory ensheathing cell‐enhanced axonal regeneration
Authors: DeLucia Tracey A. , Conners James J. , Brown Todd J. , Cronin Colleen M. , Khan Talat , Jones Kathryn J.
Published: March 2003

Olfactory ensheathing cells (OECs), a unique type of macroglia required for normal olfactory axonal regeneration throughout the lifetime of an individual, have been shown to have regeneration‐enhancing properties when used to treat various neuronal injuries. Availability of OECs is a hurdle facing future clinical use of the cells for spinal cord injury (SCI) therapy. The number of OECs that can realistically be harvested from each animal is limited, and ensuring a pure cell population is difficult. We have begun to characterize a nonsyngeneic strain of OECs, i.e., from a homogenous OEC clonal cell line (nOECs). The purpose of this study was to determine whether nOECs have the same properties and provide the same functional recovery after SCI, as primary cultures of OECs. The results indicate that nOECs survive in vivo, produce growth‐promoting proteins, and possess regeneration‐promoting capabilities. Spinal cord injured rats that were treated with nOECs performed significantly better on functional tests than injured control animals beginning at 5 weeks after operation. In summary, evidence of nOEC regeneration‐promoting capabilities suggests that this cell line can be used as potential therapy in SCI research. Anat Rec (Part B: New Anat) 271B:61–70, 2003. © 2003 Wiley‐Liss, Inc.
Mapping the HLA association in Behçet's disease: A role for tumor necrosis factor polymorphisms?
Authors: Ahmad Tariq , Wallace Graham R. , James Teifi , Neville Matt , Bunce Mike , Mulcahy‐Hawes Kim , Armuzzi Alessandro , Crawshaw Jonathan , Fortune Farida , Walton Robert , Stanford Miles R. , Welsh Ken I. , Marshall Sara E. , Jewell Derek P.
Published: March 2003

Objective

Experimental evidence suggests that inappropriate regulation of tumor necrosis factor α (TNFα) may play a role in the pathogenesis of Behçet's disease (BD). This is supported by recent reports highlighting the efficacy of anti‐TNFα agents in the treatment of this disease. The TNF gene is encoded in the class III region of the HLA complex adjacent to HLA–B. This genetic proximity to a gene that is already widely implicated in disease susceptibility led us to investigate the association between TNF promoter polymorphisms and susceptibility to BD.

Methods

We studied 133 UK white Caucasoid patients with BD and 354 healthy controls. We attempted to dissect the contribution of individual polymorphisms in this gene‐dense region by linkage disequilibrium mapping across 6 adjacent genes.

Results

We report a novel association with the TNF promoter allele TNF‐1031C. Subsequent analysis identified 2 extended HLA haplotypes associated with BD. One of them contained the previously recognized susceptibility gene HLA–B*51, while the other was defined by HLA–B*5701. Both of these haplotypes contained the TNF promoter polymorphism −1031C, an allele that was associated with disease even in individuals who did not carry either HLA–B*51 or HLA–B*5701.

Conclusion

The TNF‐1031C allele is independently associated with susceptibility to BD in Caucasoid patients. Further studies will be required to determine the functional effects of this polymorphism, its influence in disease pathogenesis, and its role in other ethnic groups.
An index of the three core data set patient questionnaire measures distinguishes efficacy of active treatment from that of placebo as effectively as the American College of Rheumatology 20% response criteria (ACR20) or the Disease Activity Score (DAS) in a rheumatoid arthritis clinical trial
Authors: Pincus T. , Strand V. , Koch G. , Amara I. , Crawford B. , Wolfe F. , Cohen S. , Felson D.
Published: March 2003

Objective

To evaluate the capacity of a pooled index of only the 3 patient self‐report questionnaire measures among the 7 American College of Rheumatology (ACR) core data set (Core Data Set) measures to distinguish efficacy of active treatment of rheumatoid arthritis (RA) with leflunomide or methotrexate versus placebo in a randomized, controlled clinical trial, and to compare the results with those obtained using the ACR 20% response criteria (ACR20), Disease Activity Score (DAS), and other pooled indices.

Methods

The 7 ACR Core Data Set measures of 1) joint swelling, 2) joint tenderness, 3) physician global assessment, 4) erythrocyte sedimentation rate (ESR), 5) functional disability, 6) pain, and 7) patient global assessment were combined into the following 5 pooled indices: “All Core Data Set” (all 7 measures), “Assessor Only” (measures 1–3), “Assessor + ESR” (measures 1–4), “Patient Only” (measures 5–7), and “Patient + ESR” (measures 4–7). The capacity of each of these 5 indices to detect differences between active treatment and placebo treatment was compared with that of the ACR20 and the DAS using 4 different analytic methods, each of which presented advantages and limitations. Agreement of the indices with one another and with the ACR20 and the DAS was analyzed according to pairwise kappa statistics and Z scores in multivariate logistic regression models.

Results

Each of the 5 indices, including “Patient Only,” had a similar capacity to detect greater efficacy of leflunomide and methotrexate versus placebo in this clinical trial, according to each of 4 methods, at similar levels of statistical and clinical significance.

Conclusion

A pooled index of patient self‐report questionnaire Core Data Set measures appears to be as informative as ACR20 responses, DAS scores, and pooled indices of all and assessor‐derived Core Data Set measures for distinguishing between active treatment and placebo treatment in this RA clinical trial.
Heterogeneity of response of rheumatoid synovium cell subsets to interleukin‐18 in relation to differential interleukin‐18 receptor expression
Authors: Kawashima Masanori , Miossec Pierre
Published: March 2003

Objective

To examine the differential response of rheumatoid arthritis (RA) synovium cell subsets to interleukin‐18 (IL‐18), the effect of IL‐18 on Th1‐cytokine production, and the regulation of IL‐18 by IL‐18 binding protein (IL‐18BP).

Methods

RA fibroblast‐like synoviocytes were stimulated with IL‐1β, IL‐12, and IL‐18, and levels of IL‐6 were measured by enzyme‐linked immunosorbent assay (ELISA). Expression of IL‐18 receptor α and β chains (IL‐18Rα and IL‐18Rβ, respectively), interferon‐γ (IFNγ), and IL‐17 messenger RNA (mRNA) by peripheral blood mononuclear cells, by total RA synovium cells containing T cells obtained after collagenase digestion, and by RA fibroblast‐like synoviocytes was determined by reverse transcription–polymerase chain reaction. Levels of IFNγ were measured by ELISA.

Results

IL‐1β and, less effectively, IL‐12 could induce RA fibroblast‐like synoviocytes to produce IL‐6, but IL‐18 failed to have an effect. Although IL‐18Rα mRNA was constitutively expressed by RA fibroblast‐like synoviocytes, IL‐18Rβ could not be detected, either with or without stimulation with IL‐1 or IL‐12. Total RA synovium cells containing T cells showed a strong expression of both IL‐18Rα and IL‐18Rβ mRNA, and only IL‐18Rβ was up‐regulated by IL‐12. The combination of IL‐12 and IL‐18 synergistically up‐regulated IFNγ mRNA expression by total RA synovium cells containing T cells, but down‐regulated that of IL‐17. IL‐12–induced IFNγ production by total RA synovium cells containing T cells was increased by additional IL‐18 and decreased by IL‐18BP.

Conclusion

These results indicate that IL‐18 plays an important role in RA inflammation and joint destruction via T cells and macrophages, but it does not have a direct effect on fibroblast‐like synoviocytes. IL‐18BP may be a tool for RA therapy because of its ability to neutralize endogenous IL‐18.
Down‐regulation of Th1‐mediated pathology in experimental arthritis by stimulation of the Th2 arm of the immune response
Authors: Mauri Claudia , Feldmann Marc , Williams Richard O.
Published: March 2003

Objective

To assess whether systemic administration of recombinant interferon‐γ (rIFNγ), a proinflammatory cytokine that influences the differentiation of naive T cells into Th1 cells, promotes the induction of arthritis in DBA/1 mice immunized with type II collagen (CII) in Freund's incomplete adjuvant (IFA) and to determine the antiarthritic effect of treatment with CII in IFA.

Methods

DBA/1 mice were immunized with CII in IFA and injected intraperitoneally with rIFNγ (8,000 units/mouse/day) or with recombinant interleukin‐12 (rIL‐12; 100 ng/mouse/day). In another experiment, mice were immunized with CII in Freund's complete adjuvant (CFA) and treated with a single dose of CII in IFA on the day of immunization or on the day of disease onset. Mice were monitored to assess the effect of the treatment on the severity of disease. Th1/Th2 cytokines and anti‐CII antibodies were measured by enzyme‐linked immunosorbent assay.

Results

The administration of rIL‐12 or rIFNγ to mice immunized with CII in IFA restored the Th1 response and resulted in the development of arthritis. We then determined whether immunization with CII in IFA had the capacity to prevent and/or ameliorate collagen‐induced arthritis. A single intraperitoneal injection of CII in IFA prevented arthritis when given at the time of immunization with CII in CFA and reduced disease severity when given at the time of arthritis onset. The administration of CII in IFA resulted in a profound down‐regulation of IFNγ production and an up‐regulation of IL‐10 in cultures of draining lymph node cells.

Conclusion

These findings demonstrate that it is possible to deflect an ongoing pathogenic Th1 response to an antigen by reimmunization of the same antigen with a Th2‐polarizing adjuvant.
Leonard Trask: The wonderful invalid: The first American description of ankylosing spondylitis
Authors: Jayson Malcolm I. V.
Published: March 2003

This report describes the first published clinical account of a case of ankylosing spondylitis in the United States. The patient progressively developed very severe kyphosis with resultant severe disability. The condition apparently started after an accident, and the report has interesting medicolegal implications.
Selective stimulation of collagen synthesis in the presence of costimulatory insulin signaling by connective tissue growth factor in scleroderma fibroblasts
Authors: Gore‐Hyer Elizabeth , Pannu Jaspreet , Smith Edwin A. , Grotendorst Gary , Trojanowska Maria
Published: March 2003

Objective

To examine the mechanism of collagen induction by connective tissue growth factor (CTGF), a profibrotic cytokine overexpressed in the skin of patients with systemic sclerosis (SSc).

Methods

Dermal fibroblasts from 7 SSc patients and 7 matched healthy adult donors were stimulated with CTGF in the presence or absence of the culture‐medium supplement, insulin–transferrin–selenium (ITS). Expression of collagen protein was analyzed by a 3H‐proline incorporation assay. To identify the signaling pathways mediating CTGF induction of collagen, pharmacologic inhibitors were used, including rottlerin, a protein kinase Cδ (PKCδ) inhibitor.

Results

Collagen levels in both SSc and normal fibroblasts were increased after treatment with transforming growth factor β in serum‐free medium, whereas no stimulation was observed following addition of CTGF. In the presence of ITS, CTGF (2.5 ng/ml) potently stimulated collagenous protein levels in SSc cell lines (n = 5); however, CTGF was not stimulatory in the majority of normal fibroblasts (n = 6). ITS alone induced collagen levels in normal fibroblasts to the levels observed in SSc skin fibroblasts, thereby diminishing the hallmark difference in basal collagen levels in these cell types. Insulin was the ITS component responsible for promoting the basal and CTGF stimulation of collagenous proteins. Rottlerin, the PKCδ inhibitor, down‐regulated collagen synthesis in normal and SSc fibroblasts cultured in ITS, and inhibited the stimulatory effects of CTGF in cooperation with insulin or of insulin (500 ng/ml) alone.

Conclusion

Increased responsiveness of SSc fibroblasts to CTGF‐mediated collagen synthesis requires the costimulatory activation of insulin signaling pathways to induce matrix production. Blockade of this effect via rottlerin may suggest that PKCδ is a downstream signaling molecule necessary for CTGF stimulation of collagen synthesis.
Specific increase in enzymatic activity of adenosine deaminase 1 in rheumatoid synovial fibroblasts
Authors: Nakamachi Yuji , Koshiba Masahiro , Nakazawa Takashi , Hatachi Saori , Saura Ryuichi , Kurosaka Masahiro , Kusaka Hideaki , Kumagai Shunichi
Published: March 2003

Objective

Adenosine deaminase (ADA; EC 3.5.4.4) activity is elevated in the synovial fluid (SF) of patients with rheumatoid arthritis (RA). Since the antiinflammatory effect of methotrexate is reportedly associated with increased levels of extracellular adenosine, the present study was undertaken to clarify the role of 2 ADA isozymes, ADA1 and ADA2, in the pathogenesis of RA.

Methods

The activities of ADA1 and ADA2 were measured in SF from RA and osteoarthritis (OA) patients, in sera from RA patients, and in lysates prepared from mononuclear and polymorphonuclear cells from SF from RA patients, peripheral blood from RA patients, and fibroblast‐like synoviocytes (FLS) from RA and OA patients. Also measured were the effects of proinflammatory cytokines on ADA1 activity and ADA messenger RNA (mRNA) expression in RA FLS, as determined using real‐time polymerase chain reaction. The adenosine concentration in RA SF was measured by radioimmunoassay.

Results

The adenosine concentration in RA SF ranged from 0.027 μM to 0.508 μM (mean ± SD 0.156 ± 0.132 μM). At those concentrations, ADA1 would be expected to be functionally dominant due to its higher affinity for adenosine. ADA1 activity in RA SF (mean ± SD 14.4 ± 8.5 IU/liter) was significantly higher than that in OA SF (3.0 ± 1.1 IU/liter) or RA sera (3.0 ± 0.6 IU/liter); moreover, ADA1 activity in RA FLS lysate was the highest among the cell lysates tested. Proinflammatory cytokines did not affect ADA1 activity or ADA mRNA expression in RA FLS.

Conclusion

Elevated ADA1 activity is an intrinsic characteristic of RA FLS, which likely contributes to the pathogenesis of RA by neutralizing the antirheumatic properties of endogenous adenosine.
The role of electronic preprints in chemical communication: Analysis of citation, usage, and acceptance in the journal literature
Authors: Brown Cecelia
Published: March 2003

This study characterizes the usage and acceptance of electronic preprints (e‐prints) in the literature of chemistry. Survey of authors of e‐prints appearing in the Chemistry Preprint Server (CPS) at http://preprints.chemweb.com indicates use of the CPS as a convenient vehicle for dissemination of research findings and for receipt of feedback before submitting to a peer‐reviewed journal. Reception of CPS e‐prints by editors of top chemistry journals is very poor. Only 6% of editors responding allow publication of articles that have previously appeared as e‐prints. Concerns focus on the lack of peer review and the uncertain permanence of e‐print storage. Consequently, it was not surprising to discover that citation analysis yielded no citations to CPS e‐prints in the traditional literature of chemistry. Yet data collected and posted by the CPS indicates that the e‐prints are valued, read, and discussed to a notable extent within the chemistry community. Thirty‐two percent of the most highly rated, viewed, and discussed e‐prints eventually appear in the journal literature, indicating the validity of the work submitted to the CPS. This investigation illustrates the ambivalence with which editors and authors view the CPS, but also gives an early sense of the potential free and rapid information dissemination, coupled with open, uninhibited discussion and evaluation, has to expand, enrich, and vitalize the scholarly discourse of chemical scientists.
A Stochastic Compartmental Model with Long Lasting Infusion
Authors: Ferrante L. , Bompadre S. , Leone L.
Published: March 2003

Most of the compartmental models in current use to model pharmacokinetic systems are deterministic. Stochastic formulations of pharmacokinetic compartmental models introduce stochasticity through either a probabilistic transfer mechanism or the randomization of the transfer rate constants. In this paper we consider a linear stochastic differential equation (LSDE) which represents a stochastic version of a one‐compartment linear model when input function undergoes random fluctuations. The solution of the LSDE, its mean value and covariance structure are derived. An explicit likelihood function is obtained either when the process is observed continuously over a period of time or when sampled data are available, as it is generally feasible. We discuss some asymptotic properties of the maximum likelihood estimators for the model parameters. Furthermore we develop expressions for two random variables of interest in pharmacokinetics: the area under the time‐concentration curve, M0(T), and the plateau concentration, xss. Finally the estimation procedure is illustrated by an application to real data.
Ratio Estimators in Stratified Random Sampling
Authors: Kadilar C. , Cingi H.
Published: March 2003

This paper considers some ratio‐type estimators and their properties are studied in stratified random sampling. The results are supported by an application with original data.
A Revisit on Comparing the Asymptotic Interval Estimators of Odds Ratio in a Single 2 × 2 Table
Authors: Lui Kung‐Jong , Lin Chii‐Dean
Published: March 2003

It is well known thatCornfield's confidence interval of the odds ratio with the continuity correction can mimic the performance of the exact method. Furthermore, because the calculation procedure of using the former is much simpler than that of using the latter,Cornfield's confidence interval with the continuity correction is highly recommended by many publications. However, all these papers that draw this conclusion are on the basis of examining the coverage probability exclusively. The efficiency of the resulting confidence intervals is completely ignored. This paper calculates and compares the coverage probability and the average length forWoolfs logit interval estimator,Gart's logit interval estimator of adding 0.50,Cornfield's interval estimator with the continuity correction, andCornfield's interval estimator without the continuity correction in a variety of situations. This paper notes thatCornfield's interval estimator with the continuity correction is too conservative, whileCornfield's method without the continuity correction can improve efficiency without sacrificing the accuracy of the coverage probability. This paper further notes that when the sample size is small (say, 20 or 30 per group) and the probability of exposure in the control group is small (say, 0.10) or large (say, 0.90), usingCornfield's method without the continuity correction is likely preferable to all the other estimators considered here. When the sample size is large (say, 100 per group) or when the probability of exposure in the control group is moderate (say, 0.50),Gart's logit interval estimator is probably the best.
Simple and efficient solid support scavenging of excess acyl donors after enzymatic acylations in organic solvents
Authors: Usyatinsky Alexander Ya. , Astakhova Nadezhda M. , Khmelnitsky Yuri L.
Published: March 2003

A simple and efficient method for removing excess acyl donors following enzymatic acylations in organic solvents was developed. This method is based on selective chemical scavenging of acyl donors using an amino‐functionalized solid support, and does not affect the desired acylated product. A wide variety of different acyl donors, including vinyl and trifluoroethyl esters and vinyl carbonates, can be quantitatively removed by this method, thus providing a simple and highly efficient tool for purification of reaction products after enzymatic acylation. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 82: 379–385, 2003.
Monitoring of a sequencing batch reactor using adaptive multiblock principal component analysis
Authors: Lee Dae Sung , Vanrolleghem Peter A.
Published: March 2003

Multiway principal component analysis (MPCA) for the analysis and monitoring of batch processes has recently been proposed. Although MPCA has found wide applications in batch process monitoring, it assumes that future batches behave in the same way as those used for model identification. In this study, a new monitoring algorithm, adaptive multiblock MPCA, is developed. The method overcomes the problem of changing process conditions by updating the covariance structure recursively. A historical set of operational data of a multiphase batch process was divided into local blocks in such a way that the variables from one phase of a batch run could be blocked in the corresponding blocks. This approach has significant benefits because the latent variable structure can change for each phase during the batch operation. The adaptive multiblock model also allows for easier fault detection and isolation by looking at the relationship between blocks and at smaller meaningful block models, and it therefore helps in the diagnosis of the disturbance. The proposed adaptive multiblock monitoring method is successfully applied to a sequencing batch reactor for biological wastewater treatment. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 82: 489–497, 2003.