bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and characterization of submicron PMMA particles containing rare earth ions on the surface
Authors: Hu Jun , Zhao Hui , Zhang Qijin , He Weidong
Published: May 2003

Emulsifier‐free emulsion polymerization was adopted to synthesize rare earth containing submicron polymer particles under microwave irradiation. To control the size and distribution of the particle, the relationship between reaction time, monomer content, and particle radius was studied for the polymerization of methyl methacrylate (MMA) in the absence and presence of rare earth ions, in which water was used as solvent, and potassium persulfate was used as initiator. In the latter polymerization, the solution of MMA and europium octanoate (EOA) was used instead of MMA itself as EOA can be dissolved in MMA within certain concentrations, and the result shows that the polymerization process is affected by existence of EOA except when the amount of MMA is 2 ml. For particles containing rare earth ions, characterization shows that mole percentage of Eu(III) ion in the surface layer with a thickness of 5 nm, which is estimated from X‐ray photo electron spectroscopy (XPS), is always larger than the value estimated by inductively coupled plasma atomic emission spectrometer (ICP‐AES) for the whole particle, indicating that surface enrichment of rare earth ions took place during the polymerization. Further characterization by XPS depth measurement after Ar+ sputtering shows the same result. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1124–1131, 2003
Grafting of itaconic acid onto LDPE by the reactive extrusion: Effect of neutralizing agents
Authors: Krivoguz Y. M. , Pesetskii S. S. , Jurkowski B.
Published: May 2003

Grafting of itaconic acid (IA) onto low‐density polyethylene (LDPE) was performed by reactive extrusion where the initiator was dicumyl peroxide, and the neutralizing agents (NAs) were zinc oxides and hydroxides as well as magnesium oxides and hydroxides. The carboxyl groups were neutralized in molten LDPE directly in the course of acid grafting, and in prefabricated functionalized polyethylene (LDPE‐g‐IA). It was found that neutralizing agents introduced into the initial reaction mixture increase the yield of LDPE‐g‐IA while the carboxyl groups were neutralized partially or totally through chemical reactions. The physical structure of LDPE‐g‐IA did not in fact suffer any substantial changes. From the standpoint of neutralization activity, the NAs studied could be arranged as follows: Zn(OH)2 > ZnO > Mg(OH)2 > MgO. NA, added into the initial reaction mixture improved the grafting efficiency of IA onto LDPE. In case of the one‐step process (neutralization simultaneously with grafting), the neutralizing effect appears stronger than that in the two‐step process (neutralization of prepared LDPE‐g‐IA). This means that neutralization of carboxyl groups in IA was less effective when NA was introduced into LDPE‐g‐IA than for the case of the initial reactive mixture. Chemical neutralization of grafted IA results in products of improved resistance to thermal oxidation and thermal stability of melt. This result is of practical importance to the opportunities for widening the application range for PE modified by grafting IA, while preparing polymer blends to be compounded, processed, and used at elevated temperatures. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 828–836, 2003
Solid‐phase microextraction (SPME) in polymer characterization—Long‐term properties and quality control of polymeric materials
Authors: Hakkarainen Minna , Gröning Mikael , Albertsson Ann‐Christine
Published: May 2003

Solid‐phase microextraction (SPME) in combination with GG‐MS was applied to quality control polyamide 6.6 collected for recycling and to study the long‐term properties and degradation of nitrile rubber, polyethylene, and polyamide 6.6. The migration of plasticizer and other additives reduces the service‐life and changes the properties of the material. It is also a possible health hazard, for example, legislation against the use of brominated flame retardants in plastic materials, is under discussion, and fast and reliable methods are required to detect such compounds in plastic materials collected for recycling. SPME rapidly and effectively extracted several brominated compounds from in‐plant collected polyamide 6.6. Migration of tris(2‐butoxyethyl)phosphate plasticizer and its degradation products from nitrile rubber during long‐term thermal ageing at 60 and 80°C was shown by SPME‐GC‐MS, while the plasticizer was not volatile enough to be detected by traditional HS‐GC‐MS. In accordance the number of degradation products extracted from thermo‐oxidized PE by HS‐SPME was three times larger than the number detected after HS‐GC‐MS analysis. SPME‐GC‐MS could also detect early signs of degradation in thermo‐oxidized virgin and in‐plant recycled polyamide 6.6 before any signs of degradation were observed by, for example, tensile testing or FTIR. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 867–873, 2003
Study of polypropylene/poly(ethylene terephthalate) bicomponent melt‐blowing process: The fiber temperature and elongational viscosity profiles of the spinline
Authors: Zhao Ron (Rongguo) , Wadsworth Larry C.
Published: May 2003

Although there are significant differences between high‐speed melt spinning and melt blowing (MB), they are similar in many important components. This study, motivated by the need to better understand the bicomponent MB process, used the basic theories of high‐speed melt spinning to estimate the fiber temperature and elongation viscosity profiles of the polypropylene/poly(ethylene terephthalate) (PP/PET) bicomponent MB process. During the MB process, the filament temperature decreased dramatically within the first 2 in. from the MB die. The fiber temperature‐decay profiles of PP, PET monocomponent, and PP/PET bicomponent filaments followed similar trends. PP filaments attenuated faster than PET filaments and the bicomponent filaments attenuated at a medium rate between that of PP and PET. Accordingly, the elongational viscosity increased significantly in the first 2 in. from the die. PET filaments exhibited higher elongational viscosity than that of 100% PP filaments. The elongational viscosity profile of 75%PP/25%PET was between that of PP and PET monocomponent filaments. These data provided important information on understanding the MB process and filament attenuation. It also suggested that the filament elongational viscosity profile is the key factor in production of finer bicomponent MB fibers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1145–1150, 2003
Electroactive characteristics of interpenetrating polymer network hydrogels composed of poly(vinyl alcohol) and poly(N‐isopropylacrylamide)
Authors: Kim Seon Jeong , Park Sang Jun , Lee Sang Min , Lee Young Moo , Kim Hee Chan , Kim Sun I.
Published: May 2003

An interpenetrating polymer network (IPN) composed of poly(vinyl alcohol) (PVA) and poly(N‐isopropylacrylamide) (PNIPAAm) was prepared by the sequential IPN method. The equilibrium swelling ratio and bending behavior under electric fields of the IPN hydrogel were measured in an aqueous NaCl solution. The IPN exhibited a high equilibrium swelling ratio, in the range 280–380%. When the IPN in aqueous NaCl solution was subjected to an electric field, the IPN showed significant and quick bending toward the cathode. The IPN hydrogel also showed stepwise bending behavior, depending on the electric stimulus. In addition, the ionic conductivity of the IPN hydrogel was measured using dielectric analysis, and its conductive behavior followed the Arrhenius equation. The conductivity of the IPN hydrogel and the activation energy for the form of the IPN were 1.68 × 10−5 S/cm at 36°C and 61.0 kJ/mol, respectively. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 890–894, 2003
Dynamic percolation phenomenon of poly(methyl methacrylate)/surface fluorinated carbon black composite
Authors: Katada A. , Konishi Y. , Isogai T. , Tominaga Y. , Asai S. , Sumita M.
Published: May 2003

The electrical resistivity of polymer filled with conductive filler, such as carbon black (CB) particles, is greatly decreased by incorporating the conductive filler. This is called the percolation phenomenon and the critical CB concentration is called the percolation threshold concentration (Φ*). For CB particle–filled insulating polymer composite at lower than Φ*, the conductive CB network is constructed in the polymer matrix when the composite is maintained at a temperature higher than the glass‐transition temperature or the melting temperature of the polymer matrix. This phenomenon is called dynamic percolation and the time to reach the substantial decrease in resistivity is called percolation time (tp). To investigate the relationship between the dynamic percolation process and the surface state of CB particles, we used three kinds of carbon black particles such as original carbon black (CB0) and fluorinated carbon black (FCB010 and FCB025)–filled poly(methyl methacrylate) (PMMA). It was observed that the dynamic percolation curves for CB0‐filled PMMA and FCB‐filled PMMA composites shifted to a shorter percolation time with increases in both the annealing temperature and the filler concentration. However, the dynamic percolation curves of FCB‐filled PMMA showed a gradually decreasing trend compared to that of CB0‐filled PMMA composites. The activation energy calculated from an Arrhenius plot of the tp against the inverse of the annealing temperature was decreased by surface fluorine treatment. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1151–1155, 2003
Cell and organ printing 1: Protein and cell printers
Authors: Wilson W. Cris , Boland Thomas
Published: May 2003

We have developed several devices for positioning organic molecules, molecular aggregates, cells, and single‐cell organisms onto solid supports. These printers can create stable, functional protein arrays using an inexpensive technology. The cell printer allows us to create cell libraries as well as cellular assemblies that mimic their respective position in organs. The printers are derived from commercially available ink‐jet printers that are modified to dispense protein or cell solutions instead of ink. We describe here the modifications to the print heads, and the printer hardware and software that enabled us to adapt the ink‐jet printers for the manufacture of cell and protein arrays. The printers have the advantage of being fully automated and computer controlled, and allow for the high‐throughput manufacture of protein and cell arrays. Anat Rec Part A 272A:491–496, 2003. © 2003 Wiley‐Liss, Inc.
Histomorphometric assessment of Haversian canal and osteocyte lacunae in different‐sized osteons in human rib
Authors: Qiu Shijing , Fyhrie David P. , Palnitkar Saroj , Rao D. Sudhaker
Published: May 2003

There is no detailed information available concerning the variations in bone, the Haversian canal, and osteocyte populations in different‐sized osteons. In this study a total of 398 secondary osteons were measured in archived rib sections from nine white men (20–25 years old). The sections were stained with basic fuchsin. The parameters included the osteon area (On.Ar), Haversian canal area (HC.Ar) and perimeter (HC.Pm), bone area (B.Ar), and osteocyte lacunar number (Lc.N). From these primary measurements the following indices were deduced: 1) lacunar number per bone area (Lc.N/B.Ar) and per osteon (Lc.N/On); 2) the ratio between Haversian canal perimeter and bone area (HC.Pm/B.Ar); and 3) the fraction of Haversian canal area (HC.Ar/On.Ar) and its complement, the fraction of bone area (B.Ar/On.Ar). The results showed that the osteons varied greatly in size, but very little in the fraction of bone area. Regression analyses showed that HC.Ar, HC.Pm, and Lc.N/On were positively associated with On.Ar (P < 0.001 for all). A significant negative correlation was found between On.Ar and Lc.N/B.Ar (P < 0.05) and HC.Pm/B.Ar (P < 0.0001). HC.Ar and HC.Pm increased significantly with increasing Lc.N/On (both P < 0.0001) rather than Lc.N/B.Ar. Lc.N/B.Ar had a significant positive correlation with HC.Ar/On.Ar (P < 0.05) and HC.Pm/B.Ar (P < 0.01). We conclude that: 1) the size of the osteon is determined by the quantum of bone removed by osteoclasts, 2) the osteon is well designed for molecular exchange, and 3) a well designed osteon may be produced via the regulation of bone apposition by osteocytes during the process of osteon refilling. Anat Rec Part A 272A:520–525, 2003. © 2003 Wiley‐Liss, Inc.
Cell and organ printing 2: Fusion of cell aggregates in three‐dimensional gels
Authors: Boland Thomas , Mironov Vladimir , Gutowska Anna , Roth Elisabeth. A. , Markwald Roger R.
Published: May 2003

We recently developed a cell printer (Wilson and Boland, 2003) that enables us to place cells in positions that mimic their respective positions in organs. However, this technology was limited to the printing of two‐dimensional (2D) tissue constructs. Here we describe the use of thermosensitive gels to generate sequential layers for cell printing. The ability to drop cells on previously printed successive layers provides a real opportunity for the realization of three‐dimensional (3D) organ printing. Organ printing will allow us to print complex 3D organs with computer‐controlled, exact placing of different cell types, by a process that can be completed in several minutes. To demonstrate the feasibility of this novel technology, we showed that cell aggregates can be placed in the sequential layers of 3D gels close enough for fusion to occur. We estimated the optimum minimal thickness of the gel that can be reproducibly generated by dropping the liquid at room temperature onto a heated substrate. Then we generated cell aggregates with the corresponding (to the minimal thickness of the gel) size to ensure a direct contact between printed cell aggregates during sequential printing cycles. Finally, we demonstrated that these closely‐placed cell aggregates could fuse in two types of thermosensitive 3D gels. Taken together, these data strongly support the feasibility of the proposed novel organ‐printing technology. Anat Rec Part A 272A:497–502, 2003. © 2003 Wiley‐Liss, Inc.
Development of the human Müllerian duct in the sexually undifferentiated stage
Authors: Hashimoto Ryozo
Published: May 2003

An embryological explanation for the development of the Müllerian duct still poses a major challenge. The development of this duct was investigated systematically in human embryos. Seven embryos (Carnegie stages 18–23) were serially sectioned in the frontal, sagittal, and transversal planes at a thickness of 10 μm and stained with hematoxylin and eosin (H&E) for histological analysis. In all observed embryos, the caudal end of the Müllerian duct was found to be intimately connected to the Wolffian duct. The opening of the Müllerian duct to the coelomic cavity was formed as the result of an invagination of the coelomic epithelium at Carnegie stage 18. The duct grew independently from the invagination during stages 19–23. The fused duct (uterovaginal canal) bifurcated at the caudal portion at Carnegie stages 22 and 23. This is the first description of the caudal portion of the fused Müllerian ducts separating again and returning to each of the Wolffian ducts in human embryos. Anat Rec Part A 272A:514–519, 2003. © 2003 Wiley‐Liss, Inc.
General suitability of techniques for in situ detection of apoptosis in small intestinal epithelium
Authors: Groos Stephanie , Reale Enrico , Luciano Liliana
Published: May 2003

The present study was designed to evaluate different techniques for the in situ detection of apoptosis in human and rat small intestinal epithelium. The techniques included light microscopy (LM) and transmission electron microscopy (TEM) observation of epoxy resin‐embedded tissue, scanning electron microscopy (SEM), TUNEL assay, and antibodies directed against caspase cleavage products of caspase 3, cytokeratin 18 (CK 18), and apoptotic single‐strand DNA (ssDNA). All techniques, if the labeling was positive, showed apoptotic cells exclusively at the villus tip. LM and TEM were the most reliable and revealed morphological signs typical of cells that have died via apoptosis. SEM indicated the extension of the process. The antibody recognizing cleaved caspase 3 could be considered an appropriate marker for apoptotic epithelial cells in human and rat small intestine. However, the majority of epithelial cells lining the proximal small intestinal villus contained only low levels of intact CK 18. Therefore, sufficient amounts of cleaved CK 18 for immunohistochemical detection were not generated during apoptosis, rendering the application of the antibody inappropriate. The antibody detecting formamide‐denatured ssDNA in apoptotic cells was both suitable and reliable; however, the particular staining procedure used compromised the tissue preservation. In comparison to this, the TUNEL assay was less reliable. Although it was performed with a commercially available ready‐to‐use kit, its application conditions had to be adjusted for each specimen on the basis of the findings produced by other techniques. Anat Rec Part A 272A:503–513, 2003. © 2003 Wiley‐Liss, Inc.
Morphologies and projections of defined classes of neurons in the submucosa of the guinea‐pig small intestine
Authors: Furness John B. , Alex George , Clark Melanie J. , Lal Varsha V.
Published: May 2003

Four types of neurons have previously been identified by neurochemical markers in the submucosal ganglia of the guinea‐pig small intestine, and functional roles have been ascribed to each type. However, morphological differences among the classes have not been determined, and there is only partial information about their projections within the submucosa. In the present work, we used intracellular microelectrodes to fill neurons of each type with biocytin, which was then converted to a permanent dye, so that the shapes of the neurons could be determined and their projections within the submucosa could be followed. Cell bodies of noncholinergic secretomotor/ vasodilator neurons had Dogiel type I morphology. These neurons, which are vasoactive intestinal peptide immunoreactive, had single axons that ran through many ganglia without providing terminals around other neurons. Cholinergic secretomotor neurons with neuropeptide Y immunoreactivity had Stach type IV morphology, and cholinergic secretomotor/vasodilator neurons had stellate cell bodies. The axons of these two types ran short distances in the plexus and did not innervate other submucosal neurons. Neurons of the fourth type, intrinsic primary afferent neurons, had cell bodies with Dogiel type II morphology and their processes supplied networks of varicose processes around other nerve cells. It is concluded that each functionally defined type of submucosal neuron has a characteristic morphology and that intrinsic primary afferent neurons synapse with secretomotor neurons to form monosynaptic secretomotor reflex circuits. Anat Rec Part A 272A:475–483, 2003. © 2003 Wiley‐Liss, Inc.
Rat anterior pituitary cells in vitro can partly reconstruct in vivo topographic affinities
Authors: Noda Takahiro , Kikuchi Motoshi , Kaidzu Sachiko , Yashiro Takashi
Published: May 2003

Hormone‐producing cells in the rat anterior pituitary gland are not randomly distributed; rather, there are specific topographic affinities among five cell types (Noda et al., Acta Histochem. Cytochem. 2001;34:313–319). In this study we reconstructed these affinities, at least partially, in primary monolayer culture. Pituitary cells collected from adult male rats were enzymatically dispersed and cultured for 72 hr at a density of 1 × 105 cells/cm2. We double‐immunostained cells using antibodies against hormones, and then used confocal laser microscopy to examine the ability of the cells to attach to each other. We also statistically analyzed the affinity of all combinations of the five types of hormone‐producing cells. We observed clusters by electron microscopy to identify junctional complexes between the cells. Confocal laser microscopy indicated that the features and attachment patterns of hormone‐producing cells in vivo were similar to those in vitro. Statistical analyses revealed that the rates at which the five types of hormone‐producing cells attached to growth hormone (GH)‐, prolactin (PRL), and luteinizing hormone (LH)‐producing cells were unequal, which suggests there are specific topographic affinities. The specific rates of adrenocorticotropic hormone (ACTH)‐producing cell attachment to GH cells, LH to PRL cells, and PRL to LH cells were high, whereas that of PRL attachment to PRL cells was low. In addition, the rates correlated with the data from our previous in vivo study. Ultrastructural observations revealed few junctional complexes between hormone‐producing cells. These results indicate that anterior pituitary hormone‐producing cells can attach to specific types of cells by means of specific and/or nonspecific adhesion factors, and can reconstruct the topographic nature of the pituitary gland. Anat Rec Part A 272A:548–555, 2003. © 2003 Wiley‐Liss, Inc.
Giant mitochondria in the retina cone inner segments of shrews of genus Sorex (Insectivora, Soricidae)
Authors: Lluch Sara , López‐Fuster María José , Ventura Jacint
Published: May 2003

The retinas of three species of shrews (Sorex araneus, S. coronatus, and S. minutus) were analyzed. Two kinds of photoreceptors were identified according to (among other characteristics) the traits of the mitochondria of their inner segments. The rod inner segments contained several round or oval mitochondria distributed longitudinally inside the ellipsoid. The cone inner segment showed a few mitochondria, which we classified as megamitochondria (maximum length = 4.22 μm in S. araneus, 5.68 μm in S. coronatus, and 2.42 μm in S. minutus). An analysis of serial thin sections in S. coronatus showed that these large organelles occurred in the apical and central portions of the ellipsoid. In the peripheral and basal regions of the ellipsoid, megamitochondria were frequently accompanied by smaller mitochondria. The giant mitochondria were irregular in form and densely packed, and a reduced cytosol was observed between each mitochondria. In general, they exhibited an electron‐dense matrix and a complex system of cristae, which varied in length and array. In mammalian retina, megamitochondria have only been described in the ellipsoid of the tree shrews Tupaia glis and T. belangeri, two diurnal Scandentia with a rich‐cone retina. In general terms, Sorex megamitochondria are morphologically very similar to those reported for Tupaia, especially in their arrangement in the cone ellipsoid. However, they differ in the orientation of the cristae. We propose that the ellipsoid of Sorex may serve two functions: as a source of energy for receptor cells, and as a device for improving the cone outer segment optics. Anat Rec Part A 272A:484–490, 2003. © 2003 Wiley‐Liss, Inc.
Morphology of aging lung in F344/N rat: Alveolar size, connective tissue, and smooth muscle cell markers
Authors: Yamamoto Yoshio , Tanaka Akiko , Kanamaru Arata , Tanaka Shin , Tsubone Hirokazu , Atoji Yasuro , Suzuki Yoshitaka
Published: May 2003

This study investigated the morphological changes of lungs in F344/N rats (9–36 months old). We initially examined general and quantitative morphological changes, and then we used immunohistochemistry to detect distributional changes in collagen subtypes (types I, III, and IV) and smooth muscle cell (SMC) markers (α‐smooth muscle actin (ASMA), γ‐smooth muscle actin (GSMA), desmin, and vimentin) in the lungs. In 24‐month‐old rats, alveolar ducts and alveolar sacs were enlarged, and alveoli were wider and shallower than in younger animals. In old rats (≥27 months), terminal and respiratory bronchioles and alveolar ducts were dilated and alveoli were more extended than in 24‐month‐old rats. No age‐related distributional changes were observed for collagen types I, III, and IV as revealed by immunohistochemistry, or elastin as revealed by resorsin fuchsin. SMCs in the extra‐ and intrapulmonary bronchi were immunoreactive for ASMA, GSMA, and desmin, but not for vimentin at all ages. In old rats (≥27 months), SMCs were loosely arranged in comparison with younger animals, and stainability for GSMA and desmin was decreased. In the respiratory bronchioles and alveolar ducts, a few cells immunoreactive for ASMA and vimentin were observed in the smooth muscle aggregations of the alveolar orifice in rats younger than 12 months. In older rats (>20 months), cells immunoreactive for ASMA and vimentin were increased in septal tips. In conclusion, extension of distal airways and immunohistochemical changes of SMC markers in F344/N rat lungs were evident by ∼24 months of age, but there was no apparent change in connective tissue morphology. Anat Rec Part A 272A:538–547, 2003. © 2003 Wiley‐Liss, Inc.
Proteoglycan degradation after injurious compression of bovine and human articular cartilage in vitro: Interaction with exogenous cytokines
Authors: Patwari Parth , Cook Michael N. , DiMicco Michael A. , Blake Simon M. , James Ian E. , Kumar Sanjay , Cole Ada A. , Lark Michael W. , Grodzinsky Alan J.
Published: May 2003

Objective

Traumatic joint injury leads to an increased risk of osteoarthritis (OA), but the progression to OA is not well understood. We undertook this study to measure aspects of proteoglycan (PG) degradation after in vitro injurious mechanical compression, including up‐regulation of enzymatic degradative expression and cytokine‐stimulated degradation.

Methods

Articular cartilage tissue explants were obtained from newborn bovine femoropatellar groove and from adult normal human donor knee and ankle tissue. Following injurious compression of the cartilage, matrix metalloproteinase 3 (MMP‐3) and MMP‐13 messenger RNA (mRNA) expression levels were measured by Northern analysis, and PG loss to the medium after cartilage injury was measured in the presence and absence of added exogenous cytokine (interleukin‐1α [IL‐1α] or tumor necrosis factor α [TNFα]).

Results

During the first 24 hours after injury in bovine cartilage, MMP‐3 mRNA levels increased 10‐fold over the levels in control cartilage (n = 3 experiments), whereas MMP‐13 mRNA levels were unchanged. PG loss was significantly increased after injury, but only by 2% of the total PG content and only for the first 3 days following injury. However, compared with injury alone or cytokine treatment alone, treatment of injured tissue with either 1 ng/ml IL‐1α or 100 ng/ml TNFα caused marked increases in PG loss (35% and 54%, respectively, of the total cartilage PG content). These interactions between cytokine treatment and injury were statistically significant. In human knee cartilage, the interaction was also significant for both IL‐1α and TNFα, although the magnitude of increase in PG loss was lower than that in bovine cartilage. In contrast, in human ankle cartilage, there was no significant interaction between injury and IL‐1α.

Conclusion

The cytokines IL‐1α and TNFα can cause a synergistic loss of PG from mechanically injured bovine and human cartilage. By attempting to incorporate interactions with other joint tissues that may be sources of cytokines, in vitro models of mechanical cartilage injury may explain aspects of the interactions between mechanical forces and degradative pathways which lead to OA progression.
One of two chondrocyte‐expressed isoforms of cartilage intermediate‐layer protein functions as an insulin‐like growth factor 1 antagonist
Authors: Johnson Kristen , Farley David , Hu Shou‐Ih , Terkeltaub Robert
Published: May 2003

Objective

Aging and osteoarthritic (OA) cartilage commonly demonstrate enhanced expression of the large, transforming growth factor β (TGFβ)–inducible glycoprotein cartilage intermediate‐layer protein (CILP) as well as enhanced extracellular inorganic pyrophosphate (PPi) that promotes the deposition of calcium pyrophosphate dihydrate crystals. In normal chondrocytes, TGFβ induces elevated chondrocyte extracellular PPi. Insulin‐like growth factor 1 (IGF‐1) normally blocks this response and reduces extracellular PPi. However, chondrocyte resistance to IGF‐1 is observed in OA and aging. Because CILP was reported to chromatographically fractionate with PPi‐generating nucleotide pyrophosphatase phosphodiesterase (NPP) activity, it has been broadly assumed that CILP itself has NPP activity. Our objective was to directly define CILP functions and their relationship to IGF‐1 in chondrocytes.

Methods

Using primary cultures of articular chondrocytes from the knee, we defined the function of the previously described CILP (CILP‐1) and of a recently described 50.6% identical protein that we designated the CILP‐2 isoform.

Results

Both CILP isoforms were constitutively expressed by primary cultured articular chondrocytes, but only CILP‐1 expression was detectable in cultured knee meniscal cartilage cells. Neither CILP isoform had intrinsic NPP activity. But CILP‐1 blocked the ability of IGF‐1 to decrease extracellular PPi, an activity specific for the CILP‐1 N‐terminal domain. The CILP‐1 N‐terminal domain also suppressed IGF‐1–induced (but not TGFβ‐induced) proliferation and sulfated proteoglycan synthesis, and it inhibited ligand‐induced IGF‐1 receptor autophosphorylation.

Conclusion

Two CILP isoforms are differentially expressed by chondrocytes. Neither CILP isoform exhibits PPi‐generating NPP activity. But, increased expression of CILP‐1, via N‐terminal domain–mediated inhibitory effects of CILP‐1 on chondrocyte IGF‐1 responsiveness, could impair chondrocyte growth and matrix repair and indirectly promote PPi supersaturation in aging and OA cartilage.
Epstein‐Barr virus load in the peripheral blood of patients with rheumatoid arthritis: Accurate quantification using real‐time polymerase chain reaction
Authors: Balandraud Nathalie , Meynard Jean Baptiste , Auger Isabelle , Sovran Helene , Mugnier Benedicte , Reviron Denis , Roudier Jean , Roudier Chantal
Published: May 2003

Objective

To determine whether patients with rheumatoid arthritis (RA) have elevated Epstein‐Barr virus (EBV) load in their peripheral blood mononuclear cells (PBMCs) and whether it is correlated with the HLA–DR genes they express, we developed an accurate EBV DNA quantitative assay using real‐time polymerase chain reaction (PCR) with fluorescent probes.

Methods

We studied the EBV DNA load in the PBMCs of 84 patients with RA, 69 normal controls, and 22 patients with rheumatic conditions other than RA. A 214‐bp segment from the long internal repeat of EBV was amplified from 500 ng of PBMC DNA (150,000 cells) and quantified by real‐time PCR with fluorescent probes.

Results

We demonstrated that in patients with RA, the EBV DNA load in PBMCs is increased almost 10‐fold compared with that in normal controls. The EBV load is stable over time and is not obviously influenced by disease‐modifying antirheumatic drugs or HLA–DR.

Conclusion

Patients with RA have elevated EBV load in their peripheral blood.
Meta‐analysis of four rheumatoid arthritis genome‐wide linkage studies: Confirmation of a susceptibility locus on chromosome 16
Authors: Fisher S. A. , Lanchbury J. S. , Lewis C. M.
Published: May 2003

Objective

Susceptibility to rheumatoid arthritis (RA) is likely to involve several genes of weak effect, and consequently, individual studies may have insufficient power to detect linkage. Four major RA genome‐wide linkage studies have been carried out, but apart from the well‐established HLA susceptibility locus, none of the reported significant regions of linkage has been replicated. We applied a genome‐search meta‐analysis to 4 RA genome searches to assess linkage across studies, using published results.

Methods

For each study, 120 genomic bins of ∼30 cM were defined and ranked according to the maximum evidence for linkage within each bin. Ranks were summed across studies and each bin was assessed empirically by the magnitude of summed rank, using a permutation test. A high summed rank indicated a region in which evidence for linkage was consistent across several studies.

Results

In addition to the HLA locus (P < 0.00002), the strongest evidence for an RA susceptibility locus was found on chromosome 16 (P = 0.004). This locus was not identified as statistically significant in any of the 4 individual RA genome searches. In total, 12 regions achieved a significant (P < 0.05) summed rank, compared with the 6 bins expected by random chance. Four of these regions (on chromosomes 6p, 16cen, 6q, and 12p) reached a significance value of P < 0.01, suggesting that a subset of these regions contains RA susceptibility loci.

Conclusion

Using a meta‐analysis approach, we have identified existing and novel putative RA susceptibility loci. These results can provide a basis for further positional and functional candidate‐gene studies, and may prove useful in other complex rheumatic diseases.
Daily pain and symptoms in children with polyarticular arthritis
Authors: Schanberg Laura E. , Anthony Kelly K. , Gil Karen M. , Maurin Elana C.
Published: May 2003

Objective

To analyze patterns of daily pain, stiffness, and fatigue related to juvenile arthritis; to examine the relationships of demographics, disease severity, and psychological adjustment to daily disease symptoms; and to examine daily disease symptoms as predictors of reduced participation in school and social activity.

Methods

For a 2‐month period, 41 children with polyarticular juvenile arthritis completed daily diaries that included measures of symptoms and function. Children also underwent an initial evaluation and 4 followup evaluations that included a joint count, laboratory testing, and completion of questionnaires assessing physical and psychosocial functioning.

Results

Children reported having pain an average of 73% of days, with the majority of children (76%) reporting pain on >60% of all days. On average, children described the intensity of their daily pain as being in the mild to moderate range; however, a significant subgroup (31%) reported pain in the severe range. Higher physician global assessment ratings, increased functional disability, and increased anxiety were significantly associated with increased daily pain and other daily symptoms. Multilevel random‐effects analyses indicated that increased daily symptoms of pain, stiffness, and fatigue were significant predictors of reduced participation in school and social activities.

Conclusion

Physicians should consider treating pain more aggressively in children with arthritis, in order to preserve function in school and social domains, as well as physical function. Moreover, optimal pain management in children with arthritis should include therapeutic regimens addressing anxiety as well as standard pharmacologic interventions.
A state space model for rub‐off triangles
Authors: Alpuim Teresa , Ribeiro Isabel
Published: May 2003

In this paper we suggest a distribution‐free state space model to be used with the Kalman filter in run‐off triangles. It works with original incremental amounts and relates the triangle with a column of observed values, which can be chosen in order to describe better the risk volume in each year. On the traditional application of run‐off triangles (the paid claims run‐off), this model relates the amount paid j years after the accident year with a column of observed values, that can be the claims paid on the first year, the number of claims, premiums, number of risks, etc. Two advantages of this model are the perfect split between observed values and random variables and the capacity to incorporate the changes in the speed of the company's reality into the model and in its projections.

Particular care is taken on the evaluation of the final forecast mean square error as well as on the estimation of the model parameters, specially the error variances. Also, two sets of claims data are analysed. In comparison with other methods, namely, the chain ladder, the analysis of variance, the Hoerl curves and the state space modelling with the chain ladder linear model, the proposed model gave a final reserve with a mean square error within the smallest. Copyright © 2003 John Wiley & Sons, Ltd.
Batch process and transfer decisions in foreign market: a real options model
Authors: Lin Chin‐Tsai , Wu Cheng‐Ru
Published: May 2003

This investigation extends the constant elasticity of substitution (CES) batch process production model of Lin et al. (J. Management syst. 2002; 9: 173) for an uncertain exchange rate by considering an export‐oriented manufacturer who can decide to switch freely between domestic and foreign locations. The export‐oriented manufacturer is risk averse and has rational expectations. As the entry cost declines, the export‐oriented manufacturer's entry trigger for the CES production function increases for transferring from a domestic and to a foreign location. Additionally, the manufacturer's exit trigger for CES production function increases for transferring from a foreign and to a domestic location. Moreover, the exit cost resembles the entry cost. Copyright © 2002 John Wiley & Sons, Ltd.
Mixture models in econometric duration analysis
Authors: Mosler Karl
Published: May 2003

Econometric duration analysis has become an important part of methodology in econometrics, bringing forth a plenty of applications. The probability distribution of the duration of a time span is modelled through its conditional hazard rate given the covariates. When some of the covariates are unobservable, the duration, given the observable covariates, has a mixture distribution. The paper surveys and discusses recent developments in the specification, estimation, diagnosis and economic application of proportional hazard models with unobservables. Copyright © 2003 John Wiley & Sons, Ltd.
A risk model driven by Lévy processes
Authors: Morales Manuel , Schoutens Wim
Published: May 2003

We present a general risk model where the aggregate claims, as well as the premium function, evolve by jumps. This is achieved by incorporating a Lévy process into the model. This seeks to account for the discrete nature of claims and asset prices. We give several explicit examples of Lévy processes that can be used to drive a risk model. This allows us to incorporate aggregate claims and premium fluctuations in the same process. We discuss important features of such processes and their relevance to risk modeling. We also extend classical results on ruin probabilities to this model. Copyright © 2003 John Wiley & Sons, Ltd.
Effect of an intervention to prevent unwanted pregnancy in adolescents. A randomized, prospective study from Nordland County, Norway, 1999–2001
Authors: Træen Bente
Published: May 2003

The aim of this study is to evaluate the effect of an intervention designed to prevent unwanted pregnancy in adolescents. A stratified sample of 74 compulsory schools was drawn at random from all compulsory schools in the county of Nordland in northern Norway. Of these 54 schools were willing to participate. The participating schools were assigned to four different groups according to a Solomon four‐group design. A total of 1183 pupils gave their informed consent for participation. For the intervention, a textbook in sex education was developed and handed out to pupils and teachers participating in the intervention groups. Data collections were carried out 1999–2001. The results from this study stem from data collected at post‐test 1. The individual was used as unit of analysis. Among adolescents who made their coital debut between the pre‐test and post‐test 1, more of those in the intervention group than in the pre‐test group reported use of contraception during first sexual intercourse. No other statistically significant effect of the intervention was found. The reason may be biased drop‐out. Copyright © 2003 John Wiley & Sons, Ltd.
Homelessness in the US and Germany: a cross‐national analysis
Authors: Tompsett Carolyn J. , Toro Paul A. , Guzicki Melissa , Schlienz Natascha , Blume Marc , Lombardo Sylvie
Published: May 2003

A public opinion survey was administered by telephone to nationally representative samples in the US and Germany to assess prevalence of homelessness as well as attitudes, opinions and knowledge regarding homelessness. Lower prevalence rates were found in Germany as compared with the US. German respondents demonstrated higher levels of general compassion, greater support for the public rights of the homeless, a greater tendency to view the homeless as trustworthy, and were more likely to view economic factors and less likely to view personal failings as integral to the problem of homelessness. Respondent age, gender, and political affiliation predicted many public opinion variables. Copyright © 2003 John Wiley & Sons, Ltd.
Myosin localization during meiosis I of crane‐fly spermatocytes gives indications about its role in division
Authors: Silverman‐Gavrila Rosalind V. , Forer Arthur
Published: May 2003

We showed previously that in crane‐fly spermatocytes myosin is required for tubulin flux [Silverman‐Gavrila and Forer, 2000a: J Cell Sci 113:597–609], and for normal anaphase chromosome movement and contractile ring contraction [Silverman‐Gavrila and Forer, 2001: Cell Motil Cytoskeleton 50:180–197]. Neither the identity nor the distribution of myosin(s) were known. In the present work, we used immunofluorescence and confocal microscopy to study myosin during meiosis‐I of crane‐fly spermatocytes compared to tubulin, actin, and skeletor, a spindle matrix protein, in order to further understand how myosin might function during cell division. Antibodies to myosin II regulatory light chain and myosin II heavy chain gave similar staining patterns, both dependent on stage: myosin is associated with nuclei, asters, centrosomes, chromosomes, spindle microtubules, midbody microtubules, and contractile rings. Myosin and actin colocalization along kinetochore fibers from prometaphase to anaphase are consistent with suggestions that acto‐myosin forces in these stages propel kinetochore fibres poleward and trigger tubulin flux in kinetochore fibres, contributing in this way to poleward chromosome movement. Myosin and actin colocalization at the cell equator in cytokinesis, similar to studies in other cells [e.g., Fujiwara and Pollard, 1978: J Cell Biol 77:182–195], supports a role of actin‐myosin interactions in contractile ring function. Myosin and skeletor colocalization in prometaphase spindles is consistent with a role of these proteins in spindle formation. After microtubules or actin were disrupted, myosin remained in spindles and contractile rings, suggesting that the presence of myosin in these structures does not require the continued presence of microtubules or actin. BDM (2,3 butanedione, 2 monoxime) treatment that inhibits chromosome movement and cytokinesis also altered myosin distributions in anaphase spindles and contractile rings, consistent with the physiological effects, suggesting also that myosin needs to be active in order to be properly distributed. Cell Motil. Cytoskeleton 55:97–113, 2003. © 2003 Wiley‐Liss, Inc.
Higher order structure of the PCM adjacent to the centriole
Authors: Ou Young Y. , Zhang Meifeng , Chi Simon , Matyas John R. , Rattner Jerome B.
Published: May 2003

The centrosome is the major microtubule organizing center in most animal cells. This cytoplasmic organelle consists of two components : a mature centriole (or a pair of centrioles) and a mass of pericentriolar material (PCM). The PCM has been described as either a cloud of material that encases the entire centriole or as a cluster of proteins divided into two subsets, one that adheres to the lateral surface of the centriole and another that extends outward from this region as a cloud of material. In contrast to these protein distribution patterns, we demonstrated in a previous study that a subset of proteins present within the PCM is integrated together to form a tube (PCM tube) with an open and closed end that is duplicated in concert with centrosome duplication. The present study was undertaken to determine if this tubular conformation represents proteins that are confined to the surface of the centriole or if it represents a subset of proteins within the cloud of material that extends outward from the centriole. We document that : (1) the PCM tube represents a portion of the PCM directly associated with the centriole; (2) the PCM tube has a specific and reproducible relationship to the polar structure of the centriole; (3) the tube is a site of cytoplasmic microtubule organization, and has a structure that influences the initial pattern of microtubule assembly within the juxta‐centriolar region; and (4) the PCM tube has a structural relationship with respect to the centriole, which allows the simultaneous expression of centriole‐ and PCM‐based functions (e.g., ciliogenesis and cytoplasmic microtubule organization). Based on these findings, we propose a new model of the PCM at the centriole. This model highlights the role played by the proximal end of the centriole in the nucleation and organization of centriole‐associated PCM, and indicates that the centrosome has an overall polarity in the region of the centriole. Cell Motil. Cytoskeleton 55:125–133, 2003. © 2003 Wiley‐Liss, Inc.
Class III β‐tubulin in human development and cancer
Authors: Katsetos Christos D. , Herman Mary M. , Mörk Sverre J.
Published: May 2003

The differential cellular expression of class III β‐tubulin isotype (βIII) is reviewed in the context of human embryological development and neoplasia. As compared to somatic organs and tissues, βIII is abundant in the central and peripheral nervous systems (CNS and PNS) where it is prominently expressed during fetal and postnatal development. As exemplified in cerebellar and sympathoadrenal neurogenesis, the distribution of βIII is neuron‐associated, exhibiting distinct temporospatial gradients according to the regional neuroepithelia of origin. However, transient expression of this protein is also present in the subventricular zones of the CNS comprising putative neuronal‐ and/or glial precursor cells, as well as in Kulchitsky neuroendocrine cells of the fetal respiratory epithelium. This temporally restricted, potentially non‐neuronal expression may have implications in the identification of presumptive neurons derived from embryonic stem cells. In adult tissues, the distribution of βIII is almost exclusively neuron‐specific. Altered patterns of expression are noted in cancer. In “embryonal”‐ and “adult‐type” neuronal tumors of the CNS and PNS, βIII is associated with neuronal differentiation and decreased cell proliferation. In contrast, the presence of βIII in gliomas and lung cancer is associated with an ascending histological grade of malignancy. Thus, βIII expression in neuronal tumors is differentiation‐dependent, while in non‐neuronal tumors it is aberrant and/or represents “dedifferentiation” associated with the acquisition of progenitor‐like phenotypic properties. Increased expression in various epithelial cancer cell lines is associated with chemoresistance to taxanes. Because βIII is present in subpopulations of neoplastic, but not in normal differentiated glial or somatic epithelial cells, the elucidation of mechanisms responsible for the altered expression of this isotype may provide insights into the role of the microtubule cytoskeleton in tumorigenesis and tumor progression. Cell Motil. Cytoskeleton 55:77–96, 2003. © 2003 Wiley‐Liss, Inc.
Contractile cochlear frame in the gecko Teratoscincus scincus
Authors: Ganeshina Olga , Vorobyev Misha
Published: May 2003

It is generally accepted that the cartilaginous frame of the reptilian cochlea has only a passive supportive function. In this study, a ribbon of contractile tissue was revealed within the cartilaginous frame of the cochlea of the gecko Teratoscincus scincus. It consisted of tightly packed cells and received an extensive blood supply. The cytoplasm of the cells was filled with cytoskeletal filaments 5–7 nm thick as revealed by electron microscopy. Isolated tissue permeabilized with Triton X‐100 or glycerol reversibly contracted in the presence of ATP. Noradrenaline caused slow relaxation of the freshly isolated tissue placed in artificial perilymph. We suggest that slow motility of the contractile tissue may adjust passive cochlear mechanics to sounds of high intensities. J. Comp. Neurol. 461:539–547, 2003. © 2003 Wiley‐Liss, Inc.