bluuebunny/crossref_metadata_2025 huggingface dataset:
Selectivity of Molecular Recognition Displayed by Monoclonal Antibodies as Compared to Receptors – a New Approach to Screen Combinatorial Libraries
Authors: Lack Oliver , Huber Walter , Woggon Wolf‐D.
Published: December 2003

Photolabeled monoclonal antibodies generated against a potent antagonist of the glycoprotein receptor GPIIb‐IIIa have been used to demonstrate that antibodies can be employed to replace receptors for on‐bead screening of combinatorial libraries.
Synthesis and Evaluation as Glycosidase Inhibitors of Isoquinuclidines Mimicking a Distorted β‐Mannopyranoside
Authors: Böhm Matthias , Lorthiois Edwige , Meyyappan Muthuppalaniappan , Vasella Andrea
Published: December 2003

Racemic and enantiomerically pure manno‐configured isoquinuclidines were synthesized and tested as glycosidase inhibitors. The racemic key isoquinuclidine intermediate was prepared in high yield by a cycloaddition (tandem Michael addition/aldolisation) of the 3‐hydroxy‐1‐tosyl‐pyridone 10 to methyl acrylate, and transformed to the racemic N‐benzyl manno‐isoquinuclidine 2 and the N‐unsubstituted manno‐isoquinuclidine 3 (twelve steps; ca. 11% from 10). Catalysis by quinine of the analogous cycloaddition of 10 to (−)‐8‐phenylmenthyl acrylate provided a single diastereoisomer in high yield, which was transformed to the desired enantiomerically pure D‐manno‐isoquinuclidines (+)‐2 and (+)‐3 (twelve steps; 23% from 10). The enantiomers (−)‐2 and (−)‐3 were prepared by using a quinidine‐promoted cycloaddition of 10 to the enantiomeric (+)‐8‐phenylmenthyl acrylate. The N‐benzyl D‐manno‐isoquinuclidine (+)‐2 is a selective and slow inhibitor of snail β‐mannosidase. Its inhibition strength and type depends on the pH (at pH 4.5: Ki=1.0 μM, mixed type, α=1.9; at pH 5.5: Ki=0.63 μM, mixed type, α=17). The N‐unsubstituted D‐manno‐isoquinuclidine (+)‐3 is a poor inhibitor. Its inhibition strength and type also depend on the pH (at pH 4.5: Ki=1.2⋅103 μM, mixed type, α=1.1; at pH 5.5: Ki=0.25⋅103 μM, mixed type, α=11). The enantiomeric N‐benzyl L‐manno‐isoquinuclidine (−)‐2 is a good inhibitor of snail β‐mannosidase, albeit noncompetitive (at pH 4.5: Ki=69 μM). The N‐unsubstituted isoquinuclidine (−)‐2 is a poor inhibitor (at pH 4.5: IC50=7.3⋅103 μM). A comparison of the inhibition by the pure manno‐isoquinuclidines (+)‐2 and (+)‐3, (+)‐2/(−)‐2 1 : 1, and (+)‐3/(−)‐3 1 : 1 with the published data for racemic 2 and 3 led to a rectification of the published data. The inhibition of snail β‐mannosidase by the isoquinuclidines 2 and 3 suggests that the hydrolysis of β‐D‐mannopyranosides by snail β‐mannosidase proceeds via a distorted conformer, in agreement with the principle of stereoelectronic control.
The role of employee reactions in predicting training effectiveness
Authors: Tan James A. , Hall Rosalie J. , Boyce Carol
Published: December 2003

Reactions to training programs tend to be poor predictors of training success, yet most training programs are
evaluated based solely on trainee reactions. In this study, we proposed that distinguishing between affective and
cognitive employee reactions may improve the prediction of trainee learning. Our results indicated that cognitive
employee reactions are related to both employee learning and employee behavior. Moreover, contrary to popular
notion, negative affective reactions best predicted employee learning. Implications and future research directions
of the results are discussed.
In the wake of the Gulf War: assessing family spending of compensation money in Sri Lanka
Authors: Gamburd Michele Ruth
Published: December 2003

Between 1997 and 2000, the United Nations Compensation Commission delivered US$4000 apiece to roughly 87,000 Sri Lankan citizens who suffered displacement and loss of employment due to Iraq's military actions in Kuwait during the Gulf War. Using qualitative ethnographic data, this essay examines 11 case studies of Kuwait returnees in the village of Naeaegama, in southern Sri Lanka. Like the majority of Sri Lankans caught in the Gulf War, these returnees are women from poor rural families who worked as domestic servants in Kuwait. The paper compares how the 11 households have spent compensation money and migrants' remittances. Spending choices reveal a clear hierarchy of priorities: buying land and building a house, providing a dowry for unmarried women, and starting a viable business. These goals reflect family‐based considerations, and use of the money illustrates the family's role as an economic as well as a social unit. The paper also explores the role of family in facilitating migration and depressing women's wages on the global market. Data reveal the local values, motives, and cultural contexts that shape individual and family decision‐making on matters of finance and migration. Family choices are products of and adaptations to globalised contexts. Copyright © 2003 John Wiley & Sons, Ltd.
Wife or worker? Worker or wife? Marriage and cross‐border migration in contemporary Japan
Authors: Piper Nicola
Published: December 2003

The global trend of increasing numbers of international couples can also be witnessed in Japan where Southeast and Northeast Asian women dominate numerically. This paper reviews the existing literature on marriage and migration exploring the connections between international migration for work and international marriage. It is argued that a dichotomous approach analysing migrant women as either migrants for marriage or overseas contract workers needs to be questioned. Based on a lack of theorising as well as a lack of empirical studies of the link between migration and marriage, the aim is to set out a new conceptual framework highlighting marriage either as the result of cross‐border migration or the cause thereof and to give some directions for future research. Copyright © 2003 John Wiley & Sons, Ltd.
Gendered structural barriers to job attainment for skilled Chinese emigrants in Canada
Authors: Salaff Janet , Greve Arent
Published: December 2003

Our study examines the career achievements of 50 professional couples that immigrated from China to Canada. We compare their job attainment when they left China with that years after immigration. We apply concepts of human capital and institutional theory to understand why the job status of the majority drops after immigrating. Human capital concepts account for most career advancement in China. Human capital theory falls short in explaining the structural barriers to achievement that affect those in the controlled professions, and especially women, in Canada. The institutional framework views immigrants' unemployment and a drop in job levels and wages as a status change. Structural concepts handle job deterioration, and in particular women's loss of status, in terms of social recognition of career paths. Structural concepts explain why immigrants' past career paths are poorly understood or are blocked in a new context. We conclude that institutional theory is more widely applicable than human capital theory for understanding the loss of job status for our sample of skilled immigrants from China. Copyright © 2003 John Wiley & Sons, Ltd.
Mediation of bone ingrowth in porous hydroxyapatite bone graft substitutes
Authors: Hing Karin A. , Best Serena M. , Tanner K. Elizabeth , Bonfield William , Revell Peter A.
Published: December 2003

Previous investigations have shown that both the early biological response and the mechanical properties of a porous hydroxyapatite bone graft substitute are highly sensitive to its pore structure. The objective of this study was to evaluate whether the pore structure continued to influence bone integration in the medium to long term. Two screened batches of porous hydroxyapatite (PHA) designated as batch A and batch B, with porosities of ∼60 and 80%, respectively, were selected for this study and implanted for periods of 5, 13, and 26 weeks into the lower femur of New Zealand White rabbits. Histomorphometric analysis of the absolute volume of bone ingrowth within batch A and B implants from 5 to 26 weeks showed that the absolute volume of bone ingrowth was consistently lower in batch A (10–21%), compared to batch B implants (24–31%). However, when the volume of bone ingrowth was normalised for the available pore space, this difference was reduced (23–47% and 32–42% for batches A and B, respectively). These observations suggest that differences in the volume of bone ingrowth initially depended on pore interconnectivity rather than pore size, whereas the volume or morphology of the PHA influenced the volume and morphology of bone ingrowth at later time points. Compression testing showed that bone ingrowth had a strong reinforcing effect on PHA bone graft substitutes, and a strong correlation was identified between mechanical properties and the absolute volume of ingrowth for both batches A and B. Furthermore, at 13 and 26 weeks, there was no significant variation in the ultimate compressive strength of integrated batch A and B implants. This similarity in ultimate mechanical properties indicated that the absolute volume of ingrowth may be mediated by the PHA structure through its impact on the dynamics of the local biomechanical environment. The results of push‐out testing showed that fixation of PHA bone graft substitutes was independent of density within the range studied, with no significant difference in the interfacial shear stress between batches A and B at each time point throughout the study. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 187–200, 2004
In vitro degradation and biocompatibility of poly(DL‐lactide‐ϵ‐caprolactone) nerve guides
Authors: Meek Marcel F. , Jansen Koen , Steendam Rob , Oeveren Wim. van , van Wachem Pauline B. , van Luyn Marja J.A.
Published: December 2003

Bridging nerve gaps by means of autologous nerve grafts involves donor nerve graft harvesting. Recent studies have focused on the use of alternative methods, and one of these is the use of biodegradable nerve guides. After serving their function, nerve guides should degrade to avoid a chronic foreign body reaction. The in vitro degradation, in vitro cytotoxicity, hemocompatibility, and short‐term in vivo foreign body reaction of poly(65/35 (85/15L/D) lactide‐ϵ‐caprolactone) nerve guides was studied. The in vitro degradation characteristics of poly(DLLA‐ϵ‐CL) nerve guides were monitored at 2‐week time intervals during a period of 22 weeks. Weight loss, degree of swelling of the tube wall, mechanical strength, thermal properties, and the intrinsic viscosity of the nerve guides were determined. Cytotoxicity was studied by measuring the cell proliferation inhibition index (CPII) on mouse fibroblasts in vitro. Cell growth was evaluated by cell counting, while morphology was assessed by light microscopy. Hemocompatibility was evaluated using a thrombin generation assay and a complement convertase assay. The foreign body reaction against poly(DLLA‐ϵ‐CL) nerve guides was investigated by examining toluidine blue stained sections. The in vitro degradation data showed that poly(DLLA‐ϵ‐CL) nerve guides do not swell, maintain their mechanical strength and flexibility for a period of about 8–10 weeks, and start to lose mass after about 10 weeks. Poly(DLLA‐ϵ‐CL) nerve guides were classified as noncytotoxic, as cytotoxicity tests demonstrated that cell morphology was not affected (CPII 0%). The thrombin generation assay and complement convertase assay indicated that the material is highly hemocompatible. The foreign body reaction against the biomaterial was mild with a light priming of the immunesystem. The results presented in this study demonstrate that poly(65/35 (85/15L/D) lactide‐ϵ‐caprolactone) nerve guides are biocompatible, and show good in vitro degradation characteristics, making these biodegradable nerve guides promising candidates for bridging peripheral nerve defects up to several centimeters. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 43–51, 2004
Neovascularization of poly(ether ester) block‐copolymer scaffolds in vivo: Long‐term investigations using intravital fluorescent microscopy
Authors: Druecke Daniel , Langer Stefan , Lamme Evert , Pieper Jeroen , Ugarkovic Marija , Steinau Hans Ulrich , Homann Heinz Herbert
Published: December 2003

Poly(ether ester) block‐copolymer scaffolds of different pore size were implanted into the dorsal skinfold chamber of balb/c mice. Using intravital fluorescent microscopy, the temporal course of neovascularization into these scaffolds was quantitatively analyzed. Three scaffold groups (diameter, 5 mm; 220–260 thickness, μm; n = 30) were implanted. Different pore sizes were evaluated: small (20–75 μm), medium (75–212 μm) and large pores (250–300 μm). Measurements were performed on days 8, 12, 16, and 20 in the surrounding normal tissue, in the border zone, and in the center of the scaffold. Standard microcirculatory parameters were assessed (plasma leakage, vessel diameter, red blood cell velocity, and functional vessel density). The large‐pored scaffolds showed significantly higher functional vessel density in the border zone and in the center (days 8 and 12) compared with the scaffold with the small and medium‐sized pores. These data correlated with a larger vessel diameter and a higher red blood cell velocity in the large‐pored scaffold group. Interestingly, during the evaluation period the microcirculatory parameters on the edge of the scaffolds returned to values similar to those found in the surrounding tissue. In the center of the scaffold, however, neovascularization was still active 20 days after implantation. Plasma leakage and vessel diameter were higher in the center of the scaffold. Red blood cell velocity and functional vessel density were 50% lower than in the surrounding tissue. In conclusion, the dorsal skinfold chamber model in mice allows long‐term study of blood vessel growth and remodeling in porous biomedical materials. The rate of vessel ingrowth into poly(ether ester) block‐copolymer scaffolds is influenced by pore size and was highest in the scaffold with the largest pores. The data generated with this model contribute to knowledge about the development of functional vessels and tissue ingrowth into biomaterials. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 10–18, 2004
Novel bioactive and biodegradable glass ceramics with high mechanical strength in the CaOSiO2B2O3 system
Authors: Ryu Hyun‐Seung , Lee Jung‐Kun , Seo Jun‐Hyuk , Kim Hwan , Hong Kug Sun , Kim Deug Joong , Lee Jae Hyup , Lee Dong‐Ho , Chang Bong‐Soon , Lee Choon‐Ki , Chung Sung‐Soo
Published: December 2003

Novel bioactive and biodegradable glass ceramics with high mechanical strength in the (50‐x/2)CaO · SiO2xB2O3 (4.2 ≤ x ≤ 17.2) system were investigated. The systems consisted of three phases: monoclinic wollastonite, calcium metaborate, and amorphous borosilicate matrix. The glass ceramics containing 4.2 mol% and 8.4 mol% B2O3 showed high bulk density and a dense microstructure. Mechanical strengths of the glass ceramics were higher than those of other bioactive ceramics: high compressive strength (2813 MPa), bending strength of 212 MPa, and fracture toughness of 3.12 MPa · m1/2. The glass‐ceramic formed apatite layer on their surface in the simulated body fluid and showed significant biodegradation. The degree of apatite formation in the glass ceramics depended on the calcium metaborate content and borosilicate glassy matrix. Additional calcium metaborate and borosilicate glassy matrix increased the apatite formation rate on the surface. It might be likely that calcium metaborate causes supersaturation of Ca ions, for its high solubility in SBF and the water‐reactive borosilicate glassy matrix formed SiOH groups on the surface to provide nucleation sites for apatite formation. Also, through in vitro test for the biocompatibility of the CaOSiO2B2O3 glass ceramics, no cytotoxicity of the glass ceramics were found. The results on bioactivity and noncytotoxicity indicated that glass ceramics in the (50‐x/2)CaO · SiO2xB2O3 (4.2 ≤ x ≤ 17.2) system could be useful as a biodegradable bone replacement material. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 79–89, 2004
Ultrasound degradation of novel polymer contrast agents
Authors: El‐Sherif Dalia M. , Lathia Justin D. , Le Ngocyen T. , Wheatley Margaret A.
Published: December 2003

This report describes an investigation into factors affecting the degradation of novel poly(lactic‐co‐glycolic acid) (PLGA) contrast agents. Contrast agents fabricated by two different methods and varying in acoustic properties were compared. The effect of ultrasound frequency (5 and 10 MHz) on degradation of the microcapsules was also studied. High‐performance liquid chromatography was used to quantify the production of lactic and glycolic acid to monitor agent degradation. The degradation pattern from the microcapsules was found to be closely related to capsule morphology; the more acoustically efficient capsules (maximum enhancement of 25 dB at 5 MHz with 0.004 mg/mL) degraded at a faster rate than those with lower acoustical efficiency (maximum enhancement of 25 dB at 5 MHz only achieved with 0.6 mg/mL). The capsules also degraded fastest when insonated at the frequency at which they gave highest backscatter. In addition, despite the use of a 50:50 PLGA copolymer, more glycolic than lactic acid was released at early time points, which reflects the greater hydrophilicity of the glycolic acid residues, and greater degradation rate of glycolic acid repeat units. The results from this study provided unique insight into the degradation behavior of hollow PLGA microcapsules, and their potential in ultrasound diagnosis and therapy. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 71–78, 2004
Fracture associated with hydrogen absorption of sustained tensile‐loaded titanium in acid and neutral fluoride solutions
Authors: Yokoyama Ken'ichi , Kaneko Kazuyuki , Miyamoto Youji , Asaoka Kenzo , Sakai Jun'ichi , Nagumo Michihiko
Published: December 2003

The fracture of commercial pure titanium in acid and neutral fluoride solutions has been examined by a sustained tensile‐loading test and hydrogen thermal desorption analysis. It was found that the fracture of titanium occurred in neutral 2.0% NaF solution as well as in 2.0% acidulated phosphate fluoride (APF) solution. The time to fracture decreased with increasing applied stress in both 2.0% APF and 2.0% NaF solutions. In the case of the same applied stress, the time to fracture in the 2.0% APF solution was shorter than that in the 2.0% NaF solution. General corrosion was exhibited on the side surface of the tested specimens. The formation of sodium titanium fluoride was observed on the surface of the immersed specimens in the 2.0% APF solution. Hydrogen desorption of the tested specimen in the 2.0% APF solution was observed with a peak at approximately 600°C. The amount of absorbed hydrogen was >300 mass ppm in the 2.0% APF solution under an applied stress for 24 h. The results of the present study imply that applying stress to titanium by immersing in fluoride solutions leads to the degradation of its mechanical properties. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 150–158, 2004
Protein Synthesis Is Required for the Transition to Ca2+‐Dependent Regulated Secretion in Progesterone‐Matured Xenopus Oocytes
Authors: Kohan Sirus A. , Gundersen Cameron B.
Published: December 2003

Calcium (Ca) ionophores trigger cortical granule exocytosis in progesterone‐matured Xenopus oocytes (eggs), but not in immature oocytes. Prior work suggested that this secretory transition involved a Ca‐dependent isoform of protein kinase C (PKC). To address this possibility, we treated eggs with several different inhibitors of Ca‐dependent PKCs. Although these agents (eg., staurosporine, Ro31–8220) completely blocked cortical granule exocytosis that is triggered in eggs by phorbol esters, they had no impact on ionomycin‐evoked secretion of cortical granule lectin. These data suggest that Ca‐dependent PKCs do not mediate secretory triggering in eggs. Instead, further investigation revealed that protein synthesis (but not RNA synthesis) was required for eggs to secrete in response to ionomycin. Moreover, we observed that when oocytes were matured by injection of maturation promoting factor (MPF), they failed to secrete in response to ionomycin. Collectively, these results suggest that the progesterone‐dependent maturation pathway induces these cells either to synthesize de novo, a protein that mediates Ca‐dependent secretory triggering, or that intrinsic Ca‐sensing machinery is modified in a protein‐synthesis‐dependent fashion. Initial efforts to distinguish between these possibilities (using Ca overlay, pharmacological and immunoblot strategies) revealed that such Ca‐binding proteins as calmodulin, synaptotagmin1, CAPS, rabphilin–3A and calcineurin were unlikely to transduce the secretory effects of ionomycin in eggs. Thus, the cortical reaction in these cells may rely on a novel mechanism for initiating Ca‐dependent exocytosis. J. Exp. Zool. 300A:113–125, 2003. © 2003 Wiley‐Liss, Inc.
Development of the adenohypophysis in the lamprey: Evolution of epigenetic patterning programs in organogenesis
Authors: Uchida Katsuhisa , Murakami Yasunori , Kuraku Shigehiro , Hirano Shigeki , Kuratani Shigeru
Published: December 2003

In gnathostomes, the adenohypophysis, a component of the hypothalamo‐hypophysial complex, is believed to develop through hierarchically organized epigenetic interactions based primarily on the topographical relationships between tissues. From a comparison of developmental processes and gene expression patterns of pituitary‐related genes between the agnathan species, lampreys and gnathostomes, we speculate on the evolutionary pathway of the vertebrate adenohypophysis. In the lamprey, this is derived from the nasohypophysial placode (NHP) that develops anterior to the oral ectoderm. The NHP can be identified by the expression of LjPitxA, before actual histogenesis, but it is initially distant from the future hypothalamic region. Subsequently, the NHP expresses both LjFgf8/17 and LjBmp2/4a gene transcripts, and grows caudally to establish a de novo contact with the hypothalamic region by the mid‐pharyngula stage. Later, the NHP gives rise to both the adenohypophysis and an unpaired nasal organ. Thus, the topographical relationship between the NHP and the hypothalamic region is established secondarily in the lamprey, unlike gnathostomes in which the equivalent relationship appears early in development. Comparing the developmental pattern of the amphioxus homologue of the adenohypophysis, we hypothesize that a modification of the regulation of the growth factor encoding gene lies behind the evolutionary changes recognized as heterochrony and heterotopy, which leads to the gnathostome hypophysial developmental pattern. J. Exp. Zool. (Mol. Dev. Evol.) 300B:32–47, 2003. © 2003 Wiley‐Liss, Inc.
K‐linked graphs with girth condition
Authors: Kawarabayashi Ken‐ichi
Published: December 2003

Recently, Mader [7] proved that every 2k‐connected graph with girth g(G) sufficiently large is k‐linked. We show here that g(G ≥ 11 will do unless k = 4,5. If k = 4,5, then g(G) ≥ 19 will do. © 2003 Wiley Periodicals, Inc. J Graph Theory 45: 48–50, 2004
Defective choosability of graphs with no edge‐plus‐independent‐set minor
Authors: Woodall Douglas R.
Published: December 2003

It is proved that, if s ≥ 2, a graph that does not have K2 + Ks = K1 + K1, s as a minor is (s, 1)*‐choosable. This completes the proof that such a graph is (s + 1 − d,d)*‐choosable whenever 0 ≤ d ≤ s −1 © 2003 Wiley Periodicals, Inc. J Graph Theory 45: 51–56, 2004
Intramolecular electrophilic aromatic substitution in gas‐phase‐protonated difunctional compounds containing one or two arylmethyl groups
Authors: Edelson‐Averbukh M. , Mandelbaum A.
Published: December 2003

A variety of dibenzyl esters and ethers undergo a rearrangement process upon isobutane chemical ionization and collision‐induced dissociation of their MH+ ions, whereby a new bond is formed between the two benzyl groups, giving rise to abundant [C14H13]+ (m/z 181) ions. This rearrangement has been explained as an intramolecular electrophilic substitution in the gas phase occurring in an ion–neutral complex formed by the cleavage of one of the benzyl–oxygen bonds. A similar highly efficient intramolecular electrophilic substitution takes place in di‐α‐ and β‐naphthylmethyl adipates affording m/z 281 [C22H17]+ ions, but not in the sterically hindered di‐9‐anthracylmethyl adipate. An analogous efficient rearrangement occurs in benzyl α‐ and β‐naphthylmethylcyclohexane‐1,4‐dicarboxylates and in benzyl α‐ and β‐phenylethylcyclohexane‐1,4‐dimethanol ethers. The analogous rearrangement is much less efficient in benzylallyl, benzylpropargyl and benzyl‐9‐anthracylmethyl derivatives, even less in benzylisopropyl and benzylacetyl analogs, and it is absent in benzyltetrahydropyranyl derivatives. The distinctive behavior of the protonated difunctional benzyl derivatives is interpreted in terms of the energy requirements of the O—R bond heterolysis of the protonated functionalities, the ability of the neutral R′ groups (non‐dissociated from the oxygen atom) to play the role of the nucleophile in the intramolecular electrophilic substitution processes and the electrophilicity of the R+ ions. Copyright © 2003 John Wiley & Sons, Ltd.
Liquid chromatography/electrospray ionization tandem mass spectrometric screening and confirmation methods for β2‐agonists in human or equine urine
Authors: Thevis Mario , Opfermann Georg , Schänzer Wilhelm
Published: December 2003

Electrospray ionization (ESI) mass spectra of 19 common β2‐agonists were investigated in terms of fragmentation pattern and dissociation behavior of the analytes, proving the origin of fragment ions and indicating mechanisms of charge‐driven and charge‐remote fragmentation. Based on these data, liquid chromatographic/ESI tandem mass spectrometric (LC/ESI‐MS/MS) screening and confirmation methods were developed for doping control purposes. These procedures employ established sample preparation steps including either acidic or enzymatic hydrolysis, alkaline extraction and, in the case of equine urine specimens, acidic re‐extraction of the analytes. In addition, a degradation product of formoterol caused by acidic hydrolysis during sample preparation could be identified and utilized as target compound in screening and also confirmation methods. The screening procedures cover 18 or 19β2‐agonists, the estimated limits of detection of which for equine and human urine samples vary between 2 and 100 ng ml−1 and between 2 and 50 ng ml−1, respectively. A single LC/MS/MS analysis can be performed in 9 min. Copyright © 2003 John Wiley & Sons, Ltd.
Two types of VIP neuronal components in rat suprachiasmatic nucleus
Authors: Kawamoto Kunihiko , Nagano Mamoru , Kanda Fumio , Chihara Kazuo , Shigeyoshi Yasufumi , Okamura Hitoshi
Published: December 2003

Vasoactive intestinal peptide (VIP) neurons constitute a large group in the suprachiasmatic nucleus (SCN) and it is thought that they are involved in the generation and entrainment of circadian rhythm. We have characterized these VIP‐expressing neurons in rat SCN by their ability to induce the mammalian Period1 (Per1) gene in response to light exposure, innervation of retinal afferents, day‐night variations in VIP mRNA, and coexpression of gastrin releasing peptide (GRP). VIP neurons in the ventrolateral SCN (SCNVL) were subdivided into two groups, light‐evoked Per1‐inducible main SCNVL (SCNVLmain) and non‐Per1‐inducible medially located SCNVL (SCNVLmed). Retinal innervation was abundant in the SCNVLmain but nearly absent in the SCNVLmed. Day‐night variation in VIP mRNA expression level was observed in the SCNVLmain but not in the SCNVLmed. GRP mRNA was seen in rarely SCNVLmed but abundant in SCNVLmain, where some neurons coexpressed VIP mRNA. These findings indicate that VIP neurons in the SCN can be divided into two topographically and functionally distinct groups. © 2003 Wiley‐Liss, Inc.
Glutamate uptake inhibitor L‐trans‐pyrrolidine 2,4‐dicarboxylate becomes neurotoxic in the presence of subthreshold concentrations of mitochondrial toxin 3‐nitropropionate: Involvement of mitochondrial reducing activity and ATP production
Authors: García Octavio , Massieu Lourdes
Published: December 2003

An increased concentration of extracellular glutamate is associated with neuronal damage induced by cerebral ischemia. We have demonstrated previously that exposure of cultured cerebellar granule neurons to L‐trans‐pyrrolidine‐2,4‐dicarboxylate (PDC), a glutamate uptake inhibitor, increases extracellular glutamate levels but does not induce neuronal damage. Coincubation of PDC, however, with a subthreshold concentration of the mitochondrial toxin, 3‐nitropropionic acid (3‐NP), results in severe damage to these neurons. We have investigated the time course of changes in mitochondrial reducing capacity and ATP levels in cerebellar granule cells after simultaneous exposure to 3‐NP and PDC, and its relation to cell viability and nuclear condensation. Although individually, 3‐NP and PDC treatments are not harmful to neurons, the simultaneous exposure to both compounds results in a progressive decline in mitochondrial reducing capacity during the first 4 hr, and a rapid decrease in ATP levels. At 4 hr, cells lose plasma membrane integrity and show condensed nuclei. In the presence of the energy substrates pyruvate and acetoacetate, the N‐methyl‐D‐apartate (NMDA) receptor antagonist, MK‐801, and the spin trapper α‐phenyl‐N‐tert‐butylnitrone (PBN), the decline in mitochondrial activity and ATP levels is prevented, the number of condensed nuclei is reduced, and plasma membrane integrity is preserved. In contrast, the broad‐spectrum caspase inhibitor Z‐Asp‐DCB (Z‐Asp‐CH2‐DCB) prevents nuclear condensation but has no effect on mitochondrial reducing capacity or cell survival. Our results show that glutamate uptake impairment rapidly induces neuronal death during inhibition of succinate dehydrogenase by a mechanism involving mitochondrial dysfunction that, if not prevented, leads to cell death. © 2003 Wiley‐Liss, Inc.
Tissue inhibitor of metalloproteinase (TIMP)‐1: The TIMPed balance of matrix metalloproteinases in the central nervous system
Authors: Gardner Jessica , Ghorpade Anuja
Published: December 2003

Astrocytes are intimately involved in the mechanisms of neural injury and repair. They participate in a variety of homeostatic functions and elicit repair responses as balance mechanisms. Currently, there is a growing appreciation of a more active role of astrocytes in neuronal signaling and function. One key homeostatic mechanism of astrocytes in tissue repair is maintained through their production of tissue inhibitors of metalloproteinases (TIMPs). The family of TIMPs (1–4) plays a central regulatory role as inhibitors of matrix metalloproteinases (MMPs), enzymes involved in extracellular matrix maintenance and remodeling. Recently, TIMP‐1, the inducible form, has been identified as a multifunctional molecule with divergent functions. It participates in wound healing and regeneration, cell morphology and survival, tumor metastasis, angiogenesis, and inflammatory responses. An imbalance of MMP/TIMP regulation has been implicated in several inflammatory diseases of the central nervous system (CNS). Here we review the conundrums of TIMP‐1 regulation in CNS pathophysiology. We propose that astrocyte‐TIMP‐1 may play an important role in CNS homeostasis and disease. Astrocyte TIMP‐1 expression is differentially regulated in inflammatory neurodegenerative diseases and may have significant therapeutic relevance. © 2003 Wiley‐Liss, Inc.
Constitutive expression of p21H‐Rasval12 in neurons induces increased axonal size and dendritic microtubule density in vivo
Authors: Seeger Gudrun , Gärtner Ulrich , Holzer Max , Arendt Thomas
Published: December 2003

The small G protein p21Ras is a key signal transducer mediating cellular growth and proliferation responses to extracellular stimuli. We investigated by electron microscopy the effects of augmented p21Ras activity on neuronal processes and microtubule arrangement in vivo. We used transgenic mice with a neuron‐specific overexpression of p21H‐RasVal12, which starts postnatally around Day 15. Axonal and dendritic diameters and the numerical density of dendritic microtubules were analyzed at postnatal Day 12 before the onset of transgene expression and in adult mice. In adult transgenic mice, calibers of both axons (corpus callosum) and dendrites (layers II/III of somatosensory cortex) were enlarged by about 57% and 79%, respectively. The increase in dendritic calibers was associated with an increment in the amount of microtubules. Even in dendrites of equivalent diameters, the number of microtubules was higher in transgenic mice compared to that in wild‐type mice suggesting an elevated microtubule density. Changes in process diameters or microtubule density were not observed at postnatal Day 12 before relevant transcription of transgenic p21H‐RasVal12. The present results extend previous findings on neuronal hypertrophy as a consequence of p21H‐RasVal12 expression and suggest a profound influence on the dendritic microtubule network. © 2003 Wiley‐Liss, Inc.
Purification and characterisation of carrot (Daucus carota L) pectinesterase
Authors: Alonso Jesús , Canet Wenceslao , Howell Nazlin , Alique Rafael
Published: December 2003

A pectinesterase isoform with an alkaline isoelectric point of over 8.66 was detected in crude extracts of carrot. The enzyme was purified by ion exchange and molecular exclusion chromatography. The molecular weight of the isoform was 25 kDa, determined in native conditions by filtration through Sephadex G‐75 SF. The enzyme showed a high affinity for its substrate, with Km and Vmax values of 0.031 mg ml−1 and 6.77 units respectively for apple pectin. The pectinesterase activity exhibited an optimum around pH 7.4 and was activated by metallic ions, with optimum activities at NaCl concentrations between 130 and 330 mM and at CaCl2 concentrations between 15 and 50 mM. The enzyme was activated most by Ca2+ and exhibited a greater tolerance of high concentrations of Na+. Comparison of its heat stability with other pectinesterases of vegetable origin indicated that the purified isoform was very thermolabile, being rendered inactive by heating for 5 min at 70 °C. The enzyme was inhibited by high concentrations of polygalacturonic acid and competitively inhibited by D‐galacturonic acid, with a Ki value of 1 mM. Copyright © 2003 Society of Chemical Industry
A new methodology for studying the performance of products against ruminal acidosis
Authors: Zamarreño Angel M , García‐Mina Jose M , Cantera Rodrigo G
Published: December 2003

This paper describes a new and convenient methodology for studying the performance of products used in the treatment of ruminal acidosis. The method is based on potentiometric titration of the increase in buffer capacity and acid consuming capacity after the addition of products to a suitable medium at physiological rumen pH values. The testing medium is a mixture of buffer substances (phosphate, maleate and volatile fatty acids) that mimics real ruminal fluid in chemical composition, pH and temperature, providing useful experimental results allowing easy testing of antacids. This methodology was applied to the testing of four raw materials (sodium bicarbonate, two calcium carbonates and magnesium oxide). Results in good agreement with theoretical predictions and field experience were obtained. Copyright © 2003 Society of Chemical Industry
Epimerisation of tea polyphenols in tea drinks
Authors: Xu Jin Ze , Leung Lai Kwok , Huang Yu , Chen Zhen‐Yu
Published: December 2003

The present study was carried out to quantify green tea epicatechin (GTE) derivatives and to investigate the origin of epicatechin epimers present in 18 selected canned or bottled tea drinks. The major GTEs present in tea are (−)‐epigallocatechin gallate (EGCG), (−)‐epigallocatechin (EGC), (−)‐epicatechin gallate (ECG) and (−)‐epicatechin (EC). HPLC analysis showed that the content of total GTEs was lower (16.4–268.3 mg l−1) in the canned and bottled tea drinks than in tea traditionally prepared as a beverage in a cup or teapot (3–5 g l−1). The major finding was that they contained higher levels of epicatechin epimers, namely (−)‐gallocatechin gallate (GCG), (−)‐gallocatechin (GC), catechin gallate (CG) and (−)‐catechin (C), than of GTEs, ranging from 7.6 to 331.8 mg l−1. To investigate the origin of these epimers, GTEs were extracted from longjing green tea and autoclaved at various temperatures for 10–60 min. It was found that at least 50% of GTEs were epimerised to their corresponding epimers when autoclaved at 120 °C for 20 min. It is concluded that epicatechin epimers in tea drinks are not originally present in green tea leaf but are instead derived from thermal conversion of GTEs. Copyright © 2003 Society of Chemical Industry
Prognostic value of intratumoral CD8+ T lymphocyte in extrahepatic bile duct carcinoma as essential immune response
Authors: Oshikiri Taro , Miyamoto Masaki , Shichinohe Toshiaki , Suzuoki Masato , Hiraoka Kei , Nakakubo Yoshihiro , Shinohara Toshiya , Itoh Tomoo , Kondo Satoshi , Katoh Hiroyuki
Published: December 2003

Background and Objectives

Tumor‐infiltrating lymphocytes form an important aspect of the host defense against an expanding neoplasm. CD8+ T cells have been identified as a prognostic factor in several cancers. Here, we investigate that the influence of CD8+ T cells on extrahepatic bile duct carcinoma (EBDC) patient survival.

Methods

CD8+ T cell immunoreactivity in 58 surgically resected EBDC specimens was investigated. The relationship between CD8+ T cell immunoreactivity and clinical and histopathologic features was analyzed.

Results

Thirty‐two tumors (55%) possessed intratumoral CD8+ T cells. The degree of intratumoral CD8+ T cell immunoreactivity demonstrated a significant relationship to lower numbers of lymph node metastasis, reduced venous invasion, decreased perineural invasion, and better pTNM staging. Intratumoral CD8+ T cells were also associated with increased patient survival. Multivariate analysis indicated that the presence of intratumoral CD8+ T cells was an independent prognostic factors.

Conclusions

The infiltration of a cancer cell nest by CD8+ T cells is a reliable marker predicting increased survival of patients with EBDC. J. Surg. Oncol. 2003;84:224–228. © 2003 Wiley‐Liss, Inc.
Randomized trial comparing neo‐adjuvant versus adjuvant chemotherapy in operable locally advanced breast cancer (T4b N0‐2 M0)
Authors: Deo S.V.S. , Bhutani Manisha , Shukla Nootan K. , Raina Vinod , Rath Goura K. , Purkayasth Joydeep
Published: December 2003

Background and Objectives

Locally advanced breast cancer (LABC) remains a major problem in developing countries. While trials utilizing neo‐adjuvant chemotherapy demonstrate superior survival rates compared to historic controls, randomized studies evaluating the precise role of neo‐adjuvant chemotherapy in LABC are lacking. In the present trial, neo‐adjuvant chemotherapy was compared against adjuvant chemotherapy to assess survival advantage in operable T4b N0‐2 M0 breast cancer.

Methods

A total of 101 women with operable LABC (T4b N0‐2 M0) were randomized. In arm A, 50 patients received 3 cycles of CEF chemotherapy before and 3 cycles following surgery. In arm B, 51 patients had primary surgery followed by 6 cycles of CEF chemotherapy. In both arms, loco‐regional radiotherapy was given after completion of CEF.

Results

The response of primary tumor to neo‐adjuvant chemotherapy was 66%, complete response (CR) 14% and partial response (PR) 52%. Clinical nodal response occurred in 95% of node positive patients. Only two (4%) patients had pathologic CR both in tumor and axilla. There was a significant (P = 0.02) increase in incidence of pathologically negative nodes in arm A. At a median follow up of 25 months, there was no significant difference in overall and disease free survival (DFS) in both arms (P = 0.42 and 0.18). Patients showing a response to neo‐adjuvant chemotherapy had better DFS (P = 0.04) compared to those who had no response.

Conclusions

Early results of the study indicate no survival benefit with the inclusion of neo‐adjuvant chemotherapy in LABC (T4b N0‐2 M0). Neo‐adjuvant chemotherapy resulted in significant down staging; good responders had a better DFS compared to those who did not respond. J. Surg. Oncol. 2003;84:192–197. © 2003 Wiley‐Liss, Inc.
Factors influencing adoption of soil and water conservation measures in southern Mali
Authors: Bodnár F. , De Graaff J.
Published: December 2003

A soil and water conservation (SWC) extension programme, promoting erosion control measures and soil fertility measures, has been going on in southern Mali since 1986. Five factors that influence farmer adoption of SWC measures were analysed: land pressure, cotton‐growing area, possession of ploughing equipment, possession of a donkey cart and farmer training in SWC. Interviews were carried out with 298 farmers and two to three fields per farmer were visited, in 30 representative villages and 30 villages with high SWC adoption. Correlation, regression and factor analysis led to the following conclusions:

Farmers in the high land‐pressure area adopt more soil fertility measures.

Farmers in the cotton‐growing area adopt less SWC measures.

Farmers with more ploughing equipment adopt more SWC measures.

Farmers with a donkey cart adopt more soil fertility measures.

Trained farmers adopt more erosion control measures.

There is a strong correlation between the adoption of erosion control measures and soil fertility measures that could not be explained by these five factors only. This suggests that there are additional factors that trigger the adoption of SWC measures. Copyright © 2003 John Wiley & Sons, Ltd.
Rigid‐Rod Polymers: Synthesis, Processing, Simulation, Structure, and Properties
Authors: Hu Xiao‐Dong , Jenkins Shawn E. , Min Byung G. , Polk Malcolm B. , Kumar Satish
Published: December 2003

Synthesis, structure, and properties of rigid‐rod polymers with special emphasis on poly(p‐phenylene benzobisoxazole) (PBO) and poly(p‐phenylene benzobisthiazole) (PBZT) have been reviewed. Recent studies on chemical modifications and molecular simulations have also been given. After nearly 20 years of research and development, PBO fiber was commercialized in the late 1990s. However, due to processing difficulties, the concept of the so called molecular composites has not been successful. Development of the high compressive strength M5 and dihydroxy‐PBI fibers clearly suggest that there is potential for further developing properties of this class of materials. Opto‐electronic properties have also been reviewed.

Synthesis of PBZT.

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Synthesis of PBZT.
Does brand name imprinting in memory increase brand information retention?
Authors: Baker William E.
Published: December 2003

This article introduces and explores the concept of brand name imprinting. Brand name imprinting is the process of creating and strengthening the brand name node in the brand memory network through brand name exposure. Brand name imprinting at a time prior to the presentation of specific brand information is posited to improve the retention of that information by strengthening the association between the brand name and brand information. The effect is proposed to be automatic and independent of other known means to strengthen memory associations (e.g., level of attention, cognitive elaboration, stimuli vividness, and stimuli distinctiveness). This research also proposes that brand names with neutral meaning better facilitate the imprinting effect, because they do not carry perceptual baggage that can interfere with the creation of new brand name–information associations. An experiment involving brand name imprinting and the learning of brand information supports these assertions. Implications for communication strategy and brand name selection are discussed. © 2003 Wiley Periodicals, Inc.
Isolation of highly pure and viable primordial germ cells from rainbow trout by GFP‐dependent flow cytometry
Authors: Kobayashi Terumasa , Yoshizaki Goro , Takeuchi Yutaka , Takeuchi Toshio
Published: December 2003

A highly pure and viable primordial germ cell (PGC) population appears to be an essential tool for establishing a cell line that can differentiate into a germ cell lineage and for studying the molecular biology and biochemistry of fish PGCs. Therefore, the aim of the present study was to establish a flow cytometric method for isolating highly pure and viable PGCs. As the material for PGC isolation, we used transgenic rainbow trout possessing the green fluorescent protein (GFP) gene driven by trout vasa‐gene regulatory sequences (pvasa‐GFP). Four independent transgenic strains were subjected to fluorescence microscopy and GFP‐dependent flow cytometric analyses. We found that some of the pvasa‐GFP transgenic strains exhibited ectopic background green fluorescence in the somatic cells aside from strong fluorescence in PGCs. Although flow cytometric analysis of genital ridge somatic cells in the four pvasa‐GFP transgenic strains revealed a wide range of GFP intensities, we proved that somatic cell contamination of the GFP‐positive cell population was markedly reduced if transgenic strains without the ectopic background green fluorescence were used. In addition, the forward light‐scattering (FS) property, which is an indication of relative cell size, and the side light‐scattering (SS) property, which is determined by cell shape and granularity, were employed to remove non‐PGC contaminants from the GFP‐positive cell population. By isolating GFP‐positive cells with high FS/SS values, we were able to effectively remove cell blebs and the apoptotic fraction. Consequently, the purities and survival rates of isolated PGCs were greatly improved compared with those using GFP intensity as a single indicator. Thus, our flow cytometric method, in combination with the selection of suitable transgenic strains without the ectopic background green fluorescence, is capable of isolating highly pure and viable PGCs from rainbow trout. By using this method in combination with cell‐cryopreservation and cell transplantation techniques, the isolated PGCs may also be used for preserving the genetic resources of endangered fish species and domesticated fish strains carrying commercially valuable traits. Mol. Reprod. Dev. 67: 91–100, 2004. © 2004 Wiley‐Liss, Inc.