bluuebunny/crossref_metadata_2025 huggingface dataset:
Disulfide‐crosslinked hyaluronan–gelatin sponge: Growth of fibrous tissue in vivo
Authors: Liu Yanchun , Shu Xiao Zheng , Gray Steven D. , Prestwich Glenn D.
Published: December 2003

The modification of hyaluronan (HA) and gelatin using dithiobis(propanoic dihydrazide) (DTP) has provided two thiolated macromolecular components of the extracellular matrix (ECM), specifically HA–DTPH and gelatin–DTPH. Blends of these thiolated ECM components were crosslinked in air to form hydrogels that were interpenetrating disulfide‐crosslinked networks. Lyophilization of the hydrogels afforded sponge‐like macroporous scaffolds suitable for cell attachment and proliferation. Increasing percentages of gelatin–DTPH (0, 25, 50, and 75%) were blended with HA–DTPH, and the resulting sponges were evaluated in vitro and in vivo as scaffolds for tissue engineering by seeding with human tracheal scar (HTS) fibroblasts. While cells failed to attach and grow in HA‐only sponges, the gelatin‐modified HA sponges promoted cell adhesion, proliferation, and spreading in vitro. Optimal attachment and growth was observed with 50% gelatin–HA sponges. Cell attachment to the gelatin–HA sponge could be blocked by preincubation of cells with a soluble fibronectin peptide Gly‐Arg‐Gly‐Asp (GRGD). Finally, HTS fibroblast‐seeded gelatin–HA sponges were implanted into the flanks of nude mice and evaluated at 2 and 8 weeks postimplantation. The sponges were fully biocompatible and new fibrous tissue formed, gradually replacing the sponge‐like scaffold. The gelatin–HA sponges act as synthetic, macroporous, covalent mimics of the ECM and constitute novel scaffolds for cell growth and tissue augmentation. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 142–149, 2004
Attachment of hyaluronan to metallic surfaces
Authors: Pitt William G. , Morris Robert N. , Mason Mitchell L. , Hall Matthew W. , Luo Yi , Prestwich Glenn D.
Published: December 2003

Metal implants are in general not compatible with the tissues of the human body, and in particular, blood exhibits a severe hemostatic response. Herein we present results of a technique to mask the surface of metals with a natural biopolymer, hyaluronan (HA). HA has minimal adverse interactions with blood and other tissues, but attachment of bioactive peptides can promote specific biological interactions. In this study, stainless steel was cleaned and then surface‐modified by covalent attachment of an epoxy silane. The epoxy was subsequently converted to an aldehyde functional group and reacted with hyaluronan through an adipic dihydrazide linkage, thus covalently immobilizing the HA onto the steel surface. Fluorescent labeling of the HA showed that the surface had a fairly uniform covering of HA. When human platelet rich plasma was placed on the HA‐coated surface, there was no observable adhesion of platelets. HA derivatized with a peptide containing the RGD peptide sequence was also bound to the stainless steel. The RGD‐containing peptide was bioactive as exemplified by the attachment and spreading of platelets on this surface. Furthermore, when the RGD peptide was replaced with the nonsense RDG sequence, minimal adhesion of platelets was observed. This type of controlled biological activity on a metal surface has potential for modulating cell growth and cellular interactions with metallic implants, such as vascular stents, orthopedic implants, heart valve cages, and more. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 95–106, 2004
Matrix metalloproteinases MMP‐2, ‐9 and tissue inhibitors TIMP‐1, ‐2 expression and secretion by primary human osteoblast cells in response to titanium, zirconia, and alumina ceramics
Authors: Oum'hamed Z. , Garnotel R. , Josset Y. , Trenteseaux C. , Laurent‐Maquin D.
Published: December 2003

Osteogenic properties of bone cells are a key parameter governing osseointegration of implant devices. In this context, osteoblasts have a central role via extracellular matrix synthesis and remodeling that they regulate through different protease activity. In this study, we have analyzed the expression of two matrix metalloproteinases (MMPs): MMP‐2 (72 kDa) and MMP‐9 (92 kDa) and their specific tissue inhibitors TIMP‐1 and TIMP‐2 in primary human osteoblastic cells. The effect of titanium, zirconia, and alumina ceramics on the synthesis of these proteases was assessed using reverse transcriptase‐polymerase chain reaction, enzyme‐linked immunosorbent assay, and zymographic analysis. Our results showed that osteoblasts express MMP‐2 and ‐9 mRNA. Furthermore, MMP‐2 mRNA expression was decreased by titanium and increased by alumina whereas zirconia did not have any significant effect. Conversely, MMP‐9 mRNA expression was stimulated by titanium but decreased with zirconia, whereas alumina induced no significant changes. Zymographic analysis has evidenced pro‐MMP‐2 gelatinolytic activity in all cell populations with time‐dependent increase profile; pro‐MMP‐9, however, was not detected. Enzyme‐linked immunosorbent assay data confirmed the production of MMP‐2 and very low levels of MMP‐9. In addition, TIMP‐1 was secreted in 24‐h‐cultured cells and increased to maximal level at 48–72 h whereas TIMP‐2 levels were very low. The interactions between human osteoblasts and the studied biomaterials altered both MMP‐2, ‐9 and TIMP‐1expression indicating that biomaterials may influence osseointegration and bone remodeling. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 114–122, 2004
Peripheral blood cell separation through surface‐modified polyurethane membranes
Authors: Higuchi Akon , Yamamiya Shin‐ichi , Yoon Boo Ok , Sakurai Masaru , Hara Mariko
Published: December 2003

Cell separation from peripheral blood was investigated using surface‐modified polyurethane (PU) membranes with different functional groups. Both red blood cells and platelets could pass through unmodified PU and PU‐SO3H membranes, whereas the red blood cells preferentially passed through PU‐N(C2H5)2 and PU‐NHC2H4OH membranes. The permeation ratio of T and B cells was <25% for the surface‐modified and unmodified PU membranes. CD34+ cells have been recognized as various kinds of stem cells including hematopoietic and mesenchymal stem cells. The adhesiveness of CD34+ cells on the PU membranes was found to be higher than that of red blood cells, platelets, T cells, or B cells. Overall, the adhesiveness of blood cells on the PU membranes increased in the following order: red blood cells ≤ platelets < T cells ≤ B cells < CD34+ cells. Treatment of PU‐COOH membranes with a human albumin solution to detach adhered blood cells, allowed recovery of mainly CD34+ cells in the permeate, whereas both red blood cells and platelets could be isolated in the permeate using unmodified PU membranes. The PU membranes showed different permeation and recovery ratios of specific cells depending on the functional groups attached to the membranes. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 34–42, 2004
Microstructural disassembly of calcium phosphates
Authors: Wang Haibo , Lee Jong‐Kook , Moursi Amr M. , Anderson David , Winnard Phillip , Powell Heather , Lannutti John
Published: December 2003

Microstructural factors may play a role in the osseointegration of calcium phosphates. In this paper, direct microstructural interactions between crystalline calcium phosphates and the biological milieu are reported. Degradation via exposure to osteoblast culture closely resembles in vivo interactions with subcutaneous tissues in a bovine model at early time periods. That these interactions were common to both experiments constitutes one of the few known examples of in vitro–in vivo correspondence. Interestingly, the degradation of phase pure hydroxyapatite (HA) in vitro was more rapid than that of biphasic HA in vivo. In both cases, grain extraction/pullout was frequently observed. This suggests a connection to smaller‐scale observations of epitaxial CHA nucleation and growth on pre‐existing HA grains. A microstructure in which the grain boundary is dissolving/corroding can apparently be disassembled by forces transmitted through biological structures. These observations are distinct from those of simple non‐biological solutions and prove that biological environments can interact with the material beneath the ceramic‐cell/ceramic‐tissue interface. Many often ignored microstructural factors—grain size, shape, grain boundary strength and the presence of impurity phases—may in fact control degradation. We also suggest that even relatively modest initial grain sizes will, in combination with the mild/absent foreign body response to calcium phosphates, result in lengthy in vivo particle resistence. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 61–70, 2004
Numerical failure analysis of glass‐fiber‐reinforced composites
Authors: Tanimoto Yasuhiro , Nishiwaki Tsuyoshi , Nemoto Kimiya
Published: December 2003

The purpose of this work was to propose a new numerical model for glass‐fiber‐reinforced composites. The proposed numerical model was constructed with orthotropic shell, isotropic shell, and beam elements representing glass fiber cloth, silica filler, and the remaining matrix resin, respectively. The proposed model was applied to failure analysis under three‐point bending conditions. The validity of the numerical model was checked through comparisons with experimental results. Four types of specimens were used: composite resin, and composite resin with neutral, upper, and lower glass‐fiber cloth reinforcement insertions. For all types, close agreement between the analytical and experimental results was confirmed. This indicates that the proposed numerical model is effective for evaluating the mechanical behaviors of glass‐fiber‐reinforced composites. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 107–113, 2004
Is re‐feeding efficiency compromised by prolonged starvation during aestivation in the green striped burrowing frog, Cyclorana alboguttata?
Authors: Cramp Rebecca L. , Franklin Craig E.
Published: December 2003

We examined several morphological parameters of the gastrointestinal tract, digesta passage rates, and nutrient assimilation efficiencies of Green‐striped Burrowing frogs (Cyclorana alboguttata) following prolonged fasting during three months of aestivation and compared these with frogs that had been continuously fed. Whole animal digesta passage rates were significantly reduced following three months aestivation as a result of a decreased digesta evacuation rate from the stomach. Furthermore, food was selectively retained in the small intestine for an increased time following three months of aestivation. Overall digestibility of food and nitrogen, carbon, and energy extraction efficiencies were not significantly different from control values following three months of aestivation. These findings suggest that C. alboguttata employs reduced digesta passage rates so as to maximize nutrient assimilation efficiency following prolonged food deprivation during aestivation. J. Exp. Zool. 300A:126–132, 2003. © 2003 Wiley‐Liss, Inc.
Ultrastructural localization of spicule matrix proteins in normal and metalloproteinase inhibitor‐treated sea urchin primary mesenchyme cells
Authors: Ingersoll Eric P. , Mcdonald Kent L. , Wilt Fred H.
Published: December 2003

Studies of the sea urchin larval skeleton have contributed greatly to our understanding of the process of biomineralization. In this study we have undertaken an investigation of the morphology of skeleton formation and the localization of proteins involved in the process of spicule formation at the electron microscope level. Sea urchin primary mesenchyme cells undergo a number of morphological changes as they synthesize the larval skeleton. They form a large spicule compartment that surrounds the growing spicule and, as spicule formation comes to an end, the density of the cytoplasm decreases. Inhibition of spicule formation by specific matrix metalloproteinase inhibitors or serum deprivation has some subtle effects on the morphology of cells and causes the accumulation of specific classes of vesicles. We have localized proteins of the organic matrix of the spicule and found that one protein, SM30, is localized to the Golgi apparatus and transport vesicles in the cytoplasm as well as throughout the occluded protein matrix of the spicule itself. This localization suggests that SM30 is an important structural protein in the spicule. Another spicule matrix protein, SM50, has a similar cytoplasmic localization, but in the spicule much of it is localized at the periphery of the spicule compartment, and consequently it may play a role in the assembly of new material onto the growing spicule or in the maintenance of the integrity of the matrix surrounding the spicule. J. Exp. Zool. 300A:101–112, 2003. © 2003 Wiley‐Liss, Inc.
Muscle enzyme activities in a deep‐sea squaloid shark, Centroscyllium fabricii, compared with its shallow‐living relative, Squalus acanthias
Authors: Treberg Jason R. , Martin R. Aidan , Driedzic William R.
Published: December 2003

The activities of several enzymes of energy metabolism were measured in the heart, red muscle, and white muscle of a deep and a shallow living squaloid shark, Centroscyllium fabricii and Squalus acanthias, respectively. The phylogenetic closeness of these species, combined with their active predatory nature, similar body form, and size makes them well matched for comparison. This is the first time such a comparison has been made involving a deep‐sea elasmobranch. Enzyme activities were similar in the heart, but generally lower in the red muscle of C. fabricii. Paralleling the trend seen in deep‐sea teleosts, the white muscle of C. fabricii had substantially lower activities of key glycolytic enzymes, pyruvate kinase and lactate dehydrogenase, relative to S. acanthias or other shallow living elasmobranchs. Unexpectedly, between the squaloid sharks examined, creatine phosphokinase activity was higher in all tissues of the deep living C. fabricii. Low white muscle glycolytic enzyme activities in the deep‐sea species coupled with high creatine phosphokinase activity suggests that the capacity for short burst swimming is likely limited once creatine phosphate supplies have been exhausted. J. Exp. Zool. 300A:133–139, 2003. © 2003 Wiley‐Liss, Inc.
Estimate and production of milk energy in two subspecies of red deer: Cervus elaphus hispanicus and C. e. scoticus
Authors: Landete‐Castillejos Tomás , Molina Pilar , Garcia Andrés , Gomez Jose Angel , Gallego Laureano
Published: December 2003

This study estimates the caloric value of red deer milk as assessed relating bomb calorimetry data with the main milk nutrients. The study also examines milk energy estimates and lactation variables to compare Iberian red deer hinds (Cervus elaphus hispanicus) and the most studied Scottish red deer (C. e. scoticus). The final model predicted energy value (Ecal) in kcal/g of fresh milk from fat (F) and protein (P) content of milk, but not lactose: Ecal = 0.345 + 8.332 F + 5.403 P. Energy content per gram of milk increased with lactation stage but there was no difference between subspecies. However, subspecies differed in the daily and total energy production. Although milk energy values appeared to differ with estimates following the most used model developed from livestock, milk energy of deer estimated by both methods showed a very high correlation with each other, and both yielded also similar correlation coefficients with the remaining lactation variables. Calf gains showed a greater correlation with mean protein content and total protein yield, than with total energy yield or other milk nutrients. Milk protein appears to be more relevant to calf growth than gross energy yield. J. Exp. Zool. 300A:152–157, 2003 © 2003 Wiley‐Liss, Inc.
How many disjoint 2‐edge paths must a cubic graph have?
Authors: Kelmans Alexander , Mubayi Dhruv
Published: December 2003

In this paper we show that every simple cubic graph on n vertices has a set of at least ⌈ n/4 ⌉ disjoint 2‐edge paths and that this bound is sharp. Our proof provides a polynomial time algorithm for finding such a set in a simple cubic graph. © 2003 Wiley Periodicals, Inc. J Graph Theory 45: 57–79, 2003
Detoxification of 4‐hydroxynonenal (HNE) in keratinocytes: characterization of conjugated metabolites by liquid chromatography/electrospray ionization tandem mass spectrometry
Authors: Aldini Giancarlo , Granata Paola , Orioli Marica , Santaniello Enzo , Carini Marina
Published: December 2003

Keratinocytes are potential targets of lipid peroxidation products (α,β‐unsaturated aldehydes) generated in the skin following UV exposure, among which the most abundant and toxic product is 4‐hydroxy‐trans‐2,3‐nonenal (HNE). The aim of this study was to investigate the ability of keratinocytes (NCTC2544 cell lines) to detoxify HNE, through characterization of metabolites, until now never demonstrated, using a combined analytical approach (liquid chromatography (LC) and liquid chromatography/mass spectrometry (LC/MS)). Incubation of cells with HNE (up to 200 µM) was performed in order to evaluate the ability of the cells to detoxify this toxic aldehyde, and indicated that the cell viability was maintained under these conditions. LC analysis of the extracellular media from keratinocytes incubated with 100 µM HNE shows a time‐dependent decrease of HNE, disappearance from the medium within 2 h and concomitant formation of two unconjugated (phase I) metabolites, 4‐hydroxy‐2‐nonenoic acid (HNA) and 1,4‐dihydroxy‐2‐nonene (DHN), which were both identified and quantified by LC and accounted for 48.8 ± 4.6% of the HNE dose. Four additional metabolites were identified in the extracellular medium by reversed‐phase LC coupled with electrospray ionization tandem mass spectrometry (LC/ESI‐MS/MS) with positive and negative ion detection as Michael adducts (phase II metabolites), arising by the addition of the nucleophilic sulfur of glutathione (GSH) to the electrophilic C‐3 of HNE, followed by oxidation–reduction enzymatic processes. The GSH–HNE conjugates were (a) S‐(4‐hydroxynonanal‐3‐yl)glutathione, (b) S‐(1,4‐dihydroxy‐nonane‐3‐yl)glutathione, (c) S‐(4‐oxononanal‐3‐yl)glutathione and (d) S‐(4‐oxo‐nonan‐1‐ol‐3‐yl)glutathione, and accounted for 52.3 ± 5.8% of the HNE dose (35 nmol mg−1 protein), as estimated indirectly by measuring the extent of cellular GSH consumption (18.7 ± 1.8 nmol mg−1 protein). The time course of HNE biotransformation was then determined by monitoring the formation of metabolites inside and outside the cell at different times after HNE addition (5–120 min). A time‐dependent and almost linear formation inside the cell was observed for all the metabolites (plateau after 15 min of incubation), followed by a rapid decay and a concomitant increase in the extracellular medium (plateau of formation after 60 min). This confirms that HNE diffuses into the cell where is totally metabolized through phase I and phase II reactions to unreactive products, which are then exported outside the cell. This is the first demonstration that skin epidermal cells are able to detoxify the cytotoxic products of lipid peroxidation. Copyright © 2003 John Wiley & Sons, Ltd.
Changing sensitivity to cell death during development of retinal photoreceptors
Authors: Chiarini Luciana B. , Leal‐Ferreira Mona Lisa , de Freitas Fabíola G. , Linden Rafael
Published: December 2003

Photoreceptor cell death occurs during both normal and pathological retinal development. We tested for selective induction and blockade of cell death in either retinal photoreceptors or their precursors. Organotypical retinal explants from rats at postnatal days 3–11 were treated in vitro for 24 hr with thapsigargin, okadaic acid, etoposide, anisomycin, or forskolin. Explant sections were examined for cell death, and identification of either photoreceptors or proliferating/immediate postmitotic cells followed imunohistochemistry for either rhodopsin or bromodeoxyuridine and proliferating cell nuclear antigen, respectively. Photoreceptor cell death was selectively induced by either thapsigargin or okadaic acid, whereas death of proliferating/immediate postmitotic cells was induced by etoposide. Prelabeling of proliferating precursors allowed direct demonstration of changing sensitivity of photoreceptors to various chemicals. Degeneration of both photoreceptors and proliferating/immediate postmitotic cells depended on protein synthesis. Increase of intracellular cyclic AMP blocked degeneration of postmitotic, but not of proliferating, photoreceptor precursors. The selective induction and blockade of cell death show that developing photoreceptors undergo progressive changes in mechanisms of programmed cell death associated with phenotypic differentiation. © 2003 Wiley‐Liss, Inc.
Dual role of cyclic AMP‐dependent protein kinase in neuritogenesis and synaptogenesis during neuronal differentiation
Authors: Tojima Takuro , Kobayashi Suguru , Ito Etsuro
Published: December 2003

To create precise neural circuits in the nervous system, neuritogenesis and synaptogenesis are the critical cellular processes during neuronal differentiation. We examined the cyclic AMP (cAMP)‐responsible signaling pathways for regulating neuritogenesis and synaptogenesis in NG108‐15 cells. A rise in intracellular cAMP concentration by a membrane‐permeable cAMP analog, dibutyryl cAMP (DBcAMP), led to an increase in the number of neurites and varicosities. Inhibition of cAMP‐dependent protein kinase (PKA) activity by a PKA inhibitor (H89) accelerated this neuritogenesis and neurite outgrowth rate. Treatment with H89, however, decreased the number of varicosities and the frequency of postsynaptic miniature current recorded in the cultured cells, resulting in suppression of synaptogenesis. Immunoblot analyses revealed that PKA activity mediates phosphorylation of a gene transcription factor, cAMP‐response element binding protein (CREB). On the other hand, inhibition of a mitogen‐activated protein kinase (MAPK)/extracellular signal‐regulated kinase (ERK) pathway by a MAPK/ERK kinase (MEK) inhibitor (PD98059) suppressed both neuritogenesis and neurite outgrowth without CREB phosphorylation. These results suggest strongly that PKA simultaneously plays two different roles in neuronal differentiation: inhibition of neuritogenesis and stimulation of synaptogenesis, via CREB‐mediated gene expression. © 2003 Wiley‐Liss, Inc.
Proteasome inhibition arrests neurite outgrowth and causes “dying‐back” degeneration in primary culture
Authors: Laser Heike , Mack Till G.A. , Wagner Diana , Coleman Michael P.
Published: December 2003

Proteasome inhibitors such as lactacystin were first isolated when assaying their ability to stimulate neurite outgrowth in neuronal‐like cell lines; however, their effect on neurites in primary culture has been largely neglected. We report here that lactacystin causes immediate arrest of nerve growth factor (NGF)‐stimulated neurite outgrowth in sympathetic and sensory explant cultures. This is followed by neurite degeneration that in sympathetic cultures has a distinctive “dying‐back” morphology. Remarkably, this occurs even at concentrations below that required to induce neurite outgrowth in PC12 cells. Thus, lactacystin opposes rather than potentiates the effect of NGF on sympathetic neurite outgrowth and the role of the ubiquitin proteasome pathway in growth and long‐term maintenance of axons and dendrites differs from that in neuritogenesis in neuronal‐like cell lines. Retrograde degeneration caused by blocking of the ubiquitin proteasome pathway may mimic some aspects of gracile axonal dystrophy, a dying‐back axonopathy in mice caused by ubiquitin hydrolase (Uch‐l1) deficiency, and may be relevant to human neurodegenerative diseases involving ubiquitination or proteasome abnormalities. © 2003 Wiley‐Liss, Inc.
Elevation of mitochondrial glutathione by γ‐glutamylcysteine ethyl ester protects mitochondria against peroxynitrite‐induced oxidative stress
Authors: Drake Jennifer , Sultana Rukhsana , Aksenova Marina , Calabrese Vittorio , Butterfield D. Allan
Published: December 2003

Mitochondria under oxidative stress are thought to play a key role in various neurodegenerative disorders by directing neurons to cell death. Protection by antioxidants against oxidative stress to mitochondria may prove to be beneficial in delaying onset or progression of these diseases. We have investigated the ability of γ‐glutamylcysteine ethyl ester (GCEE) to upregulate mitochondrial glutathione (GSH) in vivo or in vitro and protect against subsequent in vitro peroxynitrite (ONOO−) damage. Mitochondria pretreated in vitro with GCEE were protected against oxidative damage induced by peroxynitrite, as assessed by mitochondrial swelling, changes in mitochondrial membrane potential, 3‐nitrotyrosine formation, protein carbonyl formation, and cytochrome c release. Loss of mitochondrial function in neuronal cell cultures by the oxidants 2,2,′Azobis(2‐amidino‐propane)dihydrochloride (AAPH) and ONOO− was ameliorated by treatment with GCEE. In vivo studies showed that mitochondria isolated from animals injected intraperitoneally with GCEE were protected partially against oxidative modifications induced by ONOO−. Taken together, these results suggest that GCEE may be effective in increasing mitochondrial GSH and may be prove to have therapeutic relevance in neurodegenerative disorders associated with oxidative stress and mitochondrial dysfunction. © 2003 Wiley‐Liss, Inc.
Iridoids from Scrophularia buergeriana attenuate glutamate‐induced neurotoxicity in rat cortical cultures
Authors: Kim So Ra , Koo Kyung Ah , Sung Sang Hyun , Ma Choong Je , Yoon Jeong Seon , Kim Young Choong
Published: December 2003

In previous work, we isolated 7 neuroprotective iridoid glycosides from the 90% MeOH fraction of Scrophularia buergeriana (Scrophulariaceae). We therefore investigated the mode of action of 8‐O‐E‐p‐methoxycinnamoyl‐harpagide (8‐MCA‐Harp), the most potent neuroprotective iridoid, and its aglycone, harpagide (Harp) using primary cultures of rat cortical cells in vitro. 8‐MCA‐Harp only revealed its neuroprotective activity in a pretreatment paradigm; this iridoid had more selectivity in protecting neurons against N‐methyl‐D‐aspartate (NMDA)‐induced neurotoxicity as opposed to that induced by kainic acid (KA). On the other hand, Harp exerted significant neuroprotective activity when it was administered either before or after glutamate insult and protected cultured neuronal cells from neurotoxicity induced by NMDA or KA. Furthermore, Harp significantly prevented the decrease of glutathione, an antioxidative compound in the brain, in our cultures. Finally, 8‐MCA‐Harp and Harp could successfully reduce the overproduction of nitric oxide and the level of cellular peroxide in cultured neurons. Collectively, these results suggested that Harp and 8‐MCA‐Harp protected primary cultured neurons against glutamate‐induced oxidative stress primarily by acting on the antioxidative defense system and on glutamatergic receptors, respectively. © 2003 Wiley‐Liss, Inc.
Microglial cell cycle‐associated proteins control microglial proliferation in vivo and in vitro and are regulated by GM‐CSF and density‐dependent inhibition
Authors: Koguchi Ken , Nakatsuji Yuji , Okuno Tatsusada , Sawada Makoto , Sakoda Saburo
Published: December 2003

Hyperplasia of microglia is one characteristic of reactive gliosis, which is observed in various pathologic conditions in the central nervous system (CNS). To investigate the regulation mechanisms of microglial proliferation, the effect of granulocyte macrophage colony‐stimulating factor (GM‐CSF) on the expression of cell cycle‐associated proteins was examined in the microglial cell line GMI‐M6‐3. After GM‐CSF administration, cyclins D1, E, and A and cyclin‐dependent kinase inhibitor p21Cip1 were increased, and another cyclin‐dependent kinase inhibitor, p27Kip1, was decreased with morphologic transformation into ameboid form. By contrast, downregulation of these cyclins and p21Cip1, and strong upregulation of p27Kip1 accompanied by ramification were observed with GM‐CSF deprivation. We also found that GMI‐M6‐3 exhibited homotypic contact inhibition of proliferation without any morphologic transformation. The increase of p27Kip1 and the decrease of cyclin A were suggested to play an important role in microglial contact inhibition. In addition, the direct effect of p27Kip1 to inhibit microglial proliferation was demonstrated both in vitro and in vivo by overexpression of p27Kip1. © 2003 Wiley‐Liss, Inc.
Atypical antipsychotics attenuate neurotoxicity of β‐amyloid(25–35) by modulating Bax and Bcl‐Xl/s expression and localization
Authors: Wei Zelan , Mousseau Darrell D. , Richardson J. Steven , Dyck Lillian E. , Li Xin‐Min
Published: December 2003

We have demonstrated recently that atypical antipsychotics possess neuroprotective actions in H2O2‐mediated and serum‐withdrawal models of cell death. In the present study, we compared the ability of atypical and typical antipsychotics to protect against an insult mediated by Aβ(25–35), an apoptogenic fragment of the Alzheimer's disease‐related β‐amyloid (Aβ) peptide. Treatment of PC12 cell cultures with Aβ(25–35) did not significantly alter total cellular expression levels of Bax, a proapoptotic Bcl‐2 family member, or levels of Bcl‐XL, an antiapoptotic analogue. Treatment with Aβ(25–35), however, did result in mitochondrial translocation of Bax, which effectively increased the mitochondrial ratio of Bax to Bcl‐XL. This relative increase in proapoptotic molecules was reduced by pretreatment with atypical (quetiapine and olanzapine) and typical (haloperidol) antipsychotics. We also observed a selective increase in proapoptotic Bcl‐XS immunodetection in haloperidol‐treated cells, which was evident particularly in the mitochondrial compartment. This increase in proapoptotic molecules may account for the lower neuroprotective potential of haloperidol, as determined by the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium (MTT) reduction assay. The disparate neuroprotective effects of atypical and typical antipsychotics/neuroleptics may be due to their respective abilities to regulate pro‐ and anti‐apoptotic protein translocation and expression. © 2003 Wiley‐Liss, Inc.
Isolation and characterization of neural progenitor cells from post‐mortem human cortex
Authors: Schwartz Philip H. , Bryant Peter J. , Fuja Tannin J. , Su Hailing , O'Dowd Diane K. , Klassen Henry
Published: December 2003

Post‐mortem human brain tissue represents a vast potential source of neural progenitor cells for use in basic research as well as therapeutic applications. Here we describe five human neural progenitor cell cultures derived from cortical tissue harvested from premature infants. Time‐lapse videomicrography of the passaged cultures revealed them to be highly dynamic, with high motility and extensive, evanescent intercellular contacts. Karyotyping revealed normal chromosomal complements. Prior to differentiation, most of the cells were nestin, Sox2, vimentin, and/or GFAP positive, and a subpopulation was doublecortin positive. Multilineage potential of these cells was demonstrated after differentiation, with some subpopulations of cells expressing the neuronal markers β‐tubulin, MAP2ab, NeuN, FMRP, and Tau and others expressing the oligodendroglial marker O1. Still other cells expressed the classic glial marker glial fibrillary acidic protein (GFAP). RT‐PCR confirmed nestin, SOX2, GFAP, and doublecortin expression and also showed epidermal growth factor receptor and nucleostemin expression during the expansion phase. Flow cytometry showed high levels of the neural stem cell markers CD133, CD44, CD81, CD184, CD90, and CD29. CD133 markedly decreased in high‐passage, lineage‐restricted cultures. Electrophysiological analysis after differentiation demonstrated that the majority of cells with neuronal morphology expressed voltage‐gated sodium and potassium currents. These data suggest that post‐mortem human brain tissue is an important source of neural progenitor cells that will be useful for analysis of neural differentiation and for transplantation studies. © 2003 Wiley‐Liss, Inc.
Functional properties and retrogradation behaviour of native and chemically modified starch of mucuna bean (Mucuna pruriens)
Authors: Adebowale Kayode O , Lawal Olayide S
Published: December 2003

Mucuna bean (Mucuna pruriens) starch was isolated and subjected to chemical modification by oxidation and acetylation. The proximate analysis of the non‐starch components of the native starch on a dry weight basis was 92 g kg−1 moisture, 5 g kg−1 ash, 2 g kg−1 fat, 7 g kg−1 crude fibre and 19 g kg−1 protein. Chemical modification reduced the values for all the non‐starch components except the moisture level. For all the samples, swelling power and solubility increased as the temperature increased in the range 50–90 °C. The swelling power of mucuna native starch (MNS) and mucuna acetylated starch (MAS) increased with increasing acidity and alkalinity, while that of mucuna oxidised starch (MOS) only increased with increasing pH in the acidic range. The maximal solubility of all the starches was observed at pH 12. All the starch samples absorbed more oil than water. The lowest gelation concentration followed the trend MAS < MNS < MOS. Chemical modification reduced the gelatinisation temperature (Tp), while peak viscosity (Pv), hot paste viscosity (Hv) and cold paste viscosity (Cv) decreased after oxidation but increased following acetylation. The setback tendency of the native starch was reduced significantly after chemical modification. However, the breakdown value of MNS, 65 BU (Brabender units), was lower than that of MOS (78 BU) but higher than that of MAS (40 BU). Differential scanning calorimetry studies of gelatinisation and retrogradation revealed that chemical modification reduced the onset temperature (To), peak temperature (Tp) and conclusion temperature (Tc). Oxidation and acetylation reduced the gelatinisation and retrogradation enthalpies of the native starch. The enthalpy of retrogradation of the starches increased as the length of storage increased. Copyright © 2003 Society of Chemical Industry
Kinetics of ultraviolet light inactivation of Escherichia coli O157:H7 in liquid foods
Authors: Ngadi Michael , Smith James P , Cayouette Bernard
Published: December 2003

The effects of pH, depth of food medium and ultraviolet (UV) light dose on the inactivation of Escherichia coli O157:H7 in UV‐opaque products such as apple juice (pH 3.5) and egg white (pH 9.1) were investigated. The applied UV dose ranged from 0 to 6.5 mW min cm−2, while the depths of the medium were 1, 3.5, 5 and 10 mm. The pH of the medium did not affect the inactivation of E coli O157:H7, since similar inactivation characteristics were obtained for both apple juice and liquid egg white. As expected, decreasing the depth of the medium increased the inactivation of E coli O157:H7. More than a 5‐log reduction was obtained when the fluid depth and UV dose were 1 mm and 6.5 mW min cm−2 respectively. However, less than a 1‐log reduction was obtained when the fluid depth was 10 mm. A two‐phase kinetic model was used to model the inactivation of E coli O157:H7. This model indicated that at higher fluid depths the inactivation rate was controlled by the second, slower inactivation phase, resulting in a lower overall inactivation. The visual appearance of the treated apple juice and egg white did not show any discolouration changes during 4 weeks of storage at ambient temperature (25 °C). Copyright © 2003 Society of Chemical Industry
Changes in physicochemical properties and microstructure of dried squid during softening treatment
Authors: Konishi Fumiko , Fukunaga Yoshiko , Yoneda Chie , Shimomura Michiko , Kasai Midori , Hatae Keiko
Published: December 2003

Dried squid were prepared at 4 or 40 °C and softened first in water and then in alkaline solution. The physicochemical and structural changes in the dried squid during the softening treatment were examined. A significantly higher wet weight was observed for the 4 °C‐dried squid during the softening treatment compared with the 40 °C‐dried squid. The rupture stress and rupture energy of the 40 °C‐dried squid were significantly higher than those of the 4 °C‐dried squid during the softening treatment. The sodium dodecyl sulphate polyacrylamide slab gel electrophoresis (SDS‐PAGE) pattern of the 4 °C‐dried squid was almost the same as that of raw squid. The SDS‐PAGE pattern of the 40 °C‐dried squid showed many fragments of lower molecular weight. After soaking in distilled water the SDS‐PAGE pattern of the 40 °C‐dried squid did not change significantly; however, the SDS‐PAGE pattern of the 4 °C‐dried squid became the same as that of the 40 °C‐dried squid. Histological analysis by light microscopy showed the formation of muscle fibre bundles in the 40 °C‐dried squid. A higher water permeation was observed among the muscle fibres of the alkali‐softened 4 °C‐dried squid when compared with the alkali‐softened 40 °C‐dried squid. Copyright © 2003 Society of Chemical Industry
Immunodetection of legume proteins resistant to small intestinal digestion in weaned piglets
Authors: Salgado Paulo , Freire João PB , Ferreira Ricardo B , Teixeira Artur , Bento Ofélia , Abreu Manuel C , Toullec René , Lallès Jean‐Paul
Published: December 2003

Experiments were conducted to investigate the biochemistry of digestion of the major storage proteins from soya bean, pea, faba bean, blue lupin, and chickpea seeds in the ileum of piglets. Hyperimmune plasmas against the crude protein extracts and the purified 11S and 7S globulin fractions of each legume seed and an anti‐pea albumin PA2 and lectin antibody were used. They served to probe immunoblots of feed protein extracts and ileal digesta samples. Globally, the recognition by plasmas of intact or partially digested proteins in ileal digesta was rather faint, in agreement with the fairly high in vivo digestibility data obtained with these legume seed proteins. Nevertheless, immunoreactive polypeptides found in digesta of piglets fed pea, faba bean and chickpea belonged mainly to proteins of the 7S family, and to other proteins including low‐molecular weight components such as PA2 albumin and lectin in the case of pea. In piglets fed lupin, nearly intact polypeptides from the 11S family were detected. To conclude, the present immunochemical study conducted on ileal digesta of piglets revealed a few dietary legume proteins of the vicilin and albumin families. Legumin proteins were demonstrated unequivocally in the case of lupin and white chickpea. Copyright © 2003 Society of Chemical Industry
Trypsin inhibitor activity of soybean as affected by genotype and fertilisation
Authors: Vollmann Johann , Grausgruber Heinrich , Wagentristl Helmut , Wohleser Heinrich , Michele Pavel
Published: December 2003

The presence of protease inhibitors in soybean prohibits the utilisation of the raw beans for food and feed. However, little information is available about environmental influences and the effects of nitrogen and sulphur supply on the antinutritional constituents of soybean. As these factors may influence protease inhibitors, soybean genotypes segregated according to the presence or absence of the Kunitz trypsin inhibitor have been evaluated for trypsin inhibitor activity (TIA) in field trials. TIA was affected significantly by environment (geographical location), fertilisation treatment and genotype. Environmental means of TIA were between 69.5 and 104.8 mg g−1. Nitrogen application, which caused an increase in seed protein content, resulted in a reduction in TIA by about 15% as compared with the control. Remarkably, simultaneous application of nitrogen and sulphur in the form of ammonium sulphate had a similar reductive effect on TIA to that of nitrogen application alone, although soybean protease inhibitors are rich in sulphur amino acids. Significant genetic variation in TIA was found both within the genotype class with the Kunitz inhibitor present as well as within the class lacking this inhibitor. The results suggest that TIA of soybean may be modified considerably by genetic improvement and appropriate agronomic management. Copyright © 2003 Society of Chemical Industry
Compositional changes in seeds influenced by their positions in different whorls of mature sunflower head
Authors: Munshi SK , Kaushal Babita , Bajaj RK
Published: December 2003

The physicochemical characteristics of seeds located in different whorls of the sunflower (Helianthus annuus L) head at maturity have been studied. The proportion of filled seeds decreased from the peripheral to the central whorl, with a 10‐fold decrease in filled/unfilled seed ratio. The dry weight of seeds and kernels and the oil content of kernels decreased from the peripheral towards the middle and central whorls. However, the dry weight of seeds and kernels in the seed crop was significantly higher and the oil content lower than in the oil crop. The contents of starch, total soluble sugars and reducing sugars were lower in the oil crop than in the seed crop. The starch content of peripheral whorls in the seed crop was much lower than that of central whorls, with accumulation of total soluble sugars and reducing sugars, whereas much less variability was observed with respect to the position of seeds on the sunflower head in the oil crop. The mean proportion of membrane lipids was higher and that of triacylglycerols lower in the seed crop than in the oil crop. The proportions of 16:0 and 18:1 were higher in the seed crop, while that of 18:2 was higher in the oil crop. Copyright © 2003 Society of Chemical Industry
[F‐18] Fluorodeoxyglucose positron emission tomography as a tool for early recognition of incomplete tumor destruction after radiofrequency ablation for liver metastases
Authors: Donckier Vincent , Van Laethem Jean Luc , Goldman Serge , Van Gansbeke Daniel , Feron Pascale , Ickx Brigitte , Wikler David , Gelin Michel
Published: December 2003

Background and Objectives

To assess the value of FDG positron emission tomography (PET) for early detection of incomplete tumor destruction after radiofrequency ablation (RFA) for liver metastasis.

Methods

Twenty‐eight unresectable liver metastases in 17 patients were treated by RFA. Patients underwent computed tomography (CT) and FDG‐PET preoperatively, at 1 week, 1 month, and 3 months postoperatively. Postoperative CT and FDG‐PET at 1 week and 1 month were analyzed to identify hypervascular and hypermetabolic residual tumors at the RFA site. These results were correlated with follow‐up CT and, in case of reintervention, with pathologic results.

Results

In 24/28 of RFA‐treated metastases, CT and FDG‐PET at 1 week and 1 month showed no tumor residues. During follow‐up, none of these 13 patients developed local recurrence at RFA site. In four patients, FDG‐PET at 1 week and 1 month showed peripheral hypermetabolic residue after RFA, whereas CT did not revealed residual tumor. In three patients, local persistence of viable tumor cells was biopsy‐proven at reintervention. In the fourth, follow‐up CT showed subsequent development of a local recurrence.

Conclusions

FDG‐PET accurately monitors the local efficacy of RFA for treatment of liver metastases, as it early recognizes incomplete tumor ablation, not detectable on CT. J. Surg. Oncol. 2003;84:215–223. © 2003 Wiley‐Liss, Inc.
High incidence of urinary bladder involvement in carcinomas of the sigmoid and rectum: A retrospective review of 580 patients with colorectal carcinoma
Authors: Kobayashi Takashi , Kamoto Toshiyuki , Sugino Yoshio , Takeuchi Hideo , Habuchi Tomonori , Ogawa Osamu
Published: December 2003

Background and Objectives

It is not uncommon for colorectal carcinomas to invade the urinary bladder. However, the actual incidence of urinary bladder invasion of colorectal carcinomas and the common sites of the original tumors are still unclear.

Methods

The clinical records of 580 patients diagnosed with colorectal carcinoma were retrospectively reviewed. A further review of patients with urinary bladder invasion was performed.

Results

Of the 580 patients, 17 (2.9%) had a diagnosis of urinary bladder invasion intraoperatively. The incidence of bladder involvement was significantly higher in carcinomas of the sigmoid and rectum than in carcinomas of other colon segments (4.1 vs. 0.5%, P = 0.017). Although a combination of computed tomography (CT) and cystoscopy predicted 80% of the bladder involvement, preoperative diagnostic modalities could not provide information for the differentiation between macroscopic and pathological invasion or the necessity for total cystectomy.

Conclusions

The sigmoid colon and rectum were common sites of the original tumors invading the urinary bladder compared with other colon segments. CT and cystoscopy are recommended for preoperative screening of the bladder involvement of sigmoid colon and rectal cancer. However, it appeared to be difficult to predict the pathological invasion of malignant cells and the necessity for total cystectomy preoperatively. J. Surg. Oncol. 2003;84:209–214. © 2003 Wiley‐Liss, Inc.
Development policies and tropical deforestation in the southern Yucatán peninsula: centralized and decentralized approaches
Authors: Klepeis P.
Published: December 2003

It is well established that for multiple biophysical contexts there are legacies of past government policies in present land conditions. Despite this recognition, however, investigation of ongoing tropical deforestation dynamics often de‐emphasizes the past. The case of the southern Yucatán peninsula demonstrates the need for historical analysis in identifying key drivers of deforestation. The most important land‐use changes in the region over the past 100 years are connected to shifts in national development policies. These shifts represent tensions between centralized and decentralized approaches to land management—as represented by the policies of Presidents Díaz (1876–1910) and Cárdenas (1934–40)—that persisted throughout the 20th century. The legacies of these reoccurring development strategies include depleted hardwood reserves, large areas of permanently cleared forest, a complicated system of land allocation, and long‐standing tensions between economic, social welfare, and environmental conservation goals. These findings suggest that while centralized and decentralized approaches to development both focus on natural resource exploitation, the rates of deforestation tend to be faster, the patterns of forest clearing more pronounced, and land‐use decision making less democratic under systems of centralized control. These conclusions hold implications for land‐use decision making today. Copyright © 2003 John Wiley & Sons, Ltd.
Terpyridine‐Functionalized TentaGel Microbeads: Synthesis, Metal Chelation and First Sequential Complexation
Authors: Schubert Ulrich S. , Alexeev Alexander , Andres Philip R.
Published: December 2003

The functionalization of polystyrene/poly(ethylene glycol) TentaGel® microbeads (d = 20 μm) with 2,2′:6′,2″‐terpyridine units is described resulting in a material with easily accessible ligands which possess an excellent affinity for transition metal ions. The subsequent loading with different metal ions via metal‐to‐ligand complexation yielded the corresponding CoII, NiII, FeII, and CuII modified beads. The isolated materials were investigated in detail utilizing UV/vis spectroscopy, optical microscopy, atomic absorption spectroscopy (AAS), scanning electron microscopy (SEM), and atomic force microscopy (AFM). Moreover, grafting of free terpyridine moieties via ruthenium(II)/ruthenium(III)‐chemistry onto the beads is demonstrated. This opens‐up new pathways for the selective modification of such microbeads and the preparation of functional materials.

Scheme of the formation of bis‐terpyridine‐metal complexes bound to polystyrene/poly(ethylene glycol) TentaGel® microbeads.

magnified image

Scheme of the formation of bis‐terpyridine‐metal complexes bound to polystyrene/poly(ethylene glycol) TentaGel® microbeads.
Numerical analysis of reaction front propagation model under Boussinesq approximation
Authors: Agouzal A. , Allali K.
Published: December 2003

This paper deals with numerical analysis of system coupling Navier–Stokes equations with two non‐linear reaction–diffusion equations. This system modelize a propagation of reaction front at the case of polymerization. A finite elements approximation is presented, the existence and uniqueness are established. Optimal error estimates are given. Copyright © 2003 John Wiley & Sons, Ltd.