bluuebunny/crossref_metadata_2025 huggingface dataset:
Helicobacter pyloriinfection and gastric cancer: Facing the enigmas
Authors: Lunet Nuno , Barros Henrique
Published: August 2003

At an individual levelHelicobacter pyloriwas associated with the occurrence of gastric cancer but in some African and Asian countries its prevalence runs with low gastric cancer rates, the so‐called African and Asian enigmas. We assessed whether the association between gastric cancer andH. pyloriprevalence at an area level is modified by the level of exposure to fruits and vegetables, alcohol or tobacco. Regression models were fitted to data from 58 countries using as dependent variable log transformed gastric cancer rates and as independent covariables theH. pyloriprevalence, fruits and vegetables consumption, cigarette smoking, alcohol intake and interaction terms. The levels of alcohol consumption or cigarette smoking modified the association between gastric cancer andH. pyloriinfection. Models includingH. pyloriprevalence, alcohol consumption, cigarette smoking and the interaction termsH. pylori× alcohol orH. pylori× tobacco were used to compute gastric cancer incidence multiplying regression coefficients by aH. pyloriprevalence of 85% (the approximate median in African countries) and the median figures observed in each continent for alcohol and tobacco availability. The expected gastric cancer incidence per 100,000 would be 5.7 assuming the alcohol and tobacco availability in African countries, 7.0 in Asia and Oceania, 16.0 in America and 26.0 in Europe. The interaction betweenH. pyloriand cigarette or alcohol consumption may contribute to further explain the international variation in gastric cancer and the so‐called African and Asian enigmas. © 2003 Wiley‐Liss, Inc.
Dietary risk factors for testicular carcinoma
Authors: Garner Michael J. , Birkett Nicholas J. , Johnson Kenneth C. , Shatenstein Bryna , Ghadirian Parviz , Krewski Daniel ,   Canadian Cancer Registries Epidemiology Research Group
Published: August 2003

Although testicular cancer is a relatively rare lesion, accounting for only 1.1% of all malignant neoplasms in males in Canada, it is the most common cancer among Canadian men 20–45 years of age. Knowledge of the causes of testicular cancer risk in general, and more specifically, its association with diet, remain limited. Data from 601 cases of testicular cancer and 744 population‐based controls collected in 8 of the 10 Canadian provinces between 1994–97 were used to explore the relationship between diet and testicular cancer risk. We systematically examined 17 food groups, 15 nutrients and 4 individual foods based on data collected through a 69‐item food‐frequency questionnaire. Our results suggest that high dairy product intake, in particular high intake of cheese (odds ratio [OR] = 1.87; 95% confidence interval [CI] 1.22–2.86; p‐trend < 0.001), is associated with an elevated risk of testicular cancer in Canadian males. © 2003 Wiley‐Liss, Inc.
Loss of heterozygosity in serial plasma DNA samples during follow‐up of women with breast cancer
Authors: Wang Qiu , Larson Pamela S. , Schlechter Benjamin L. , Zahid Naila , Finnemore Erin , de las Morenas Antonio , Blanchard Rita A. , Rosenberg Carol L.
Published: August 2003

We evaluated the potential utility of occult circulating tumor DNA as a molecular marker of disease in subjects previously diagnosed with breast cancer. Using 24 microsatellite markers located at sites of frequent loss of heterozygosity (LOH) or allele imbalance in breast cancer, we analyzed DNA from 16 primary tumors (Stage IIA or more advanced) and 30 longitudinally collected plasma specimens. Clinical data at the time of plasma collection were obtained. All 16 tumors were characterized by an individual pattern of LOH. LOH was detected in 12 of 30 (40%) plasma samples, taken from 8 of 14 (57%) subjects. However, the number of LOH in plasma was small (n = 15), and the mean proportion of LOH was much lower than in the tumors (0.05 vs. 0.52). Although infrequent, 12 of 15 (80%) plasma LOH were concordant with abnormalities in the paired tumors, and the mean percent LOH was higher than in normal plasmas, suggesting that they were authentic tumor‐derived abnormalities. We found, despite this, no association, between plasma LOH and tumor stage or clinical status at time of blood collection (i.e., LOH was as common in subjects with no evident disease as in those with evident disease). In addition, detection of LOH was not consistent between serial samples from 5 of 11 subjects (45%), despite stable clinical conditions. No association with clinical outcome was evident, although the sample size was small. Microsatellite instability in plasma was infrequent, nonconcordant with paired tumor and inconsistent in serial samples. This pilot study suggests that identifying tumor‐specific LOH in the plasma of breast cancer subjects may not be useful for detecting occult metastases or for monitoring disease. Other detection techniques may be more promising, but circulating tumor DNA may not be a sufficiently accurate reflection of breast cancer clinical status or tumor activity. © 2003 Wiley‐Liss, Inc.
Incentive effects in the demand for health care: a bivariate panel count data estimation
Authors: Riphahn Regina T. , Wambach Achim , Million Andreas
Published: August 2003

This paper contributes in three dimensions to the literature on health care demand. First, it features the first application of a bivariate random effects estimator in a count data setting, to permit the efficient estimation of this type of model with panel data. Second, it provides an innovative test of adverse selection and confirms that high‐risk individuals are more likely to acquire supplemental add‐on insurance. Third, the estimations yield that in accordance with the theory of moral hazard, we observe a much lower frequency of doctor visits among the self‐employed, and among mothers of small children. Copyright © 2002 John Wiley & Sons, Ltd.
Evaluating interval forecasts of high‐frequency financial data
Authors: Clements Michael P. , Taylor Nick
Published: August 2003

A number of methods of evaluating the validity of interval forecasts of financial data are analysed, and illustrated using intraday FTSE100 index futures returns. Some existing interval forecast evaluation techniques, such as the Markov chain approach of Christoffersen (1998), are shown to be inappropriate in the presence of periodic heteroscedasticity. Instead, we consider a regression‐based test, and a modified version of Christoffersen's Markov chain test for independence, and analyse their properties when the financial time series exhibit periodic volatility. These approaches lead to different conclusions when interval forecasts of FTSE100 index futures returns generated by various GARCH(1,1) and periodic GARCH(1,1) models are evaluated. Copyright © 2003 John Wiley & Sons, Ltd.
Testing long‐run PPP with infinite‐variance returns
Authors: Falk Barry , Wang Chun‐Hsuan
Published: August 2003

This paper investigates the long‐run purchasing power parity hypothesis when exchange rate returns and inflation rates are assumed to be heavy‐tailed stochastic processes. More specifically, residual‐based and likelihood‐ratio‐based cointegration tests of PPP that explicitly allow for infinite‐variance innovations are applied to monthly data (1973:1–1999:12) for Belgium, Canada, Denmark, France, Germany, Italy, Japan, the Netherlands, Norway, Spain, Sweden, and the United Kingdom. Our test results are marginally less supportive of PPP when the innovations are assumed to be infinite‐variance, α‐stable processes. Copyright © 2003 John Wiley & Sons, Ltd.
Three‐dimensional culture of differentiating marrow stromal osteoblasts in biomimetic poly(propylene fumarate‐co‐ethylene glycol)‐based macroporous hydrogels
Authors: Behravesh Esfandiar , Mikos Antonios G.
Published: August 2003

This study assesses the ability of biomimetic poly(propylene fumarate‐co‐ethylene glycol)‐based hydrogels to sustain the differentiation of marrow stromal cells (MSCs) to the osteoblastic phenotype and to produce a mineralized matrix in vitro. Macroporous hydrogels based on poly(propylene fumarate‐co‐ethylene glycol) with and without covalently linked RGD cell‐adhesive peptide were synthesized and seeded with rat MSCs suspended in media or in a type I collagen solution. Cells suspended in media were found to adhere to RGD‐modified but not to unmodified hydrogels. Cells suspended in a collagen solution were entrapped after collagen gelation and proliferated independent of the peptide modification of the hydrogel. Hydrogel modification with RGD peptide was sufficient to allow for the adhesion and differentiation of MSCs to the osteoblastic phenotype in the presence of osteogenic culture supplements. MSCs seeded with a collagen gel onto RGD‐modified macroporous hydrogels after 28 days of culture showed a significant increase in cell numbers, from 15,200 ± 2,000 to 208,600 ± 69,700 cells (p < 0.05). Moreover, significant calcium deposition was apparent after 28 days of culture in RGD‐modified hydrogels for cells suspended in a collagen gel in comparison to cells suspended in media, 3.47 ± 0.26 compared to 0.82 ± 0.20 mg Ca2+ per scaffold (p < 0.05). Confocal microscopy revealed that MSCs suspended in a collagen gel and cultured on RGD‐modified hydrogels for 28 days were adhered to the surface of the hydrogel while MSCs suspended in a collagen gel and cultured on unmodified hydrogels were located within the pores of and not in direct contact with the hydrogel surface. The results demonstrate that these biomimetic hydrogels facilitate the adhesion and support the differentiation of MSCs to the osteoblastic phenotype in the presence of osteogenic culture media. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A: 698–706, 2003
Acceleration effect of basic fibroblast growth factor on the regeneration of peripheral nerve through a 15‐mm gap
Authors: Wang Shenguo , Cai Qing , Hou Jianwei , Bei Jianzhong , Zhang Tao , Yang Jian , Wan Yuqing
Published: August 2003

In this study, nerve guides composed of poly(D,L‐lactide) (PDLLA) were fabricated and used in the repair of transected sciatic nerves (15‐mm gaps) of rats. Nerve guides with a two‐ply structure (inner layer dense, outer layer microporous) were prepared by controlling the solvent evaporation rate. Then basic fibroblast growth factor (bFGF) was embedded in the inner layer of the nerve guides. Thus the inner dense layer not only could prevent the ingrowth of fibroblast and avoid the outgrowing nerve cable, but it also could retain the released bFGF in the guide lumen. The outer porous layer allowed vascular ingrowth and the diffusion of essential nutrients into the guide lumen. The data show that by using this nerve guide, the transected 15‐mm sciatic nerve was regenerated successfully within 4 months. The recovery of function of the regenerated nerves was significantly accelerated by bFGF, as indicated by an electrostimulation test and histologic assays. In addition, the bFGF retained its bioactivity during embedding and continuously was released from the matrix, as confirmed by the results of both the dorsal root ganglia (DRG) and the Schwann cell culture in the presence of PDLLA matrix containing bFGF. The released bFGF enhanced the ability of the nerve fibers to sprout from dorsal root ganglia, and it accelerated the proliferation of Schwann cells. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A: 522–531, 2003
Nanoscalein vivoevaluation of the stiffness ofDrosophila melanogasterintegument during development
Authors: Kohane M. , Daugela A. , Kutomi H. , Charlson L. , Wyrobek A. , Wyrobek J.
Published: August 2003

A quasistatic nanoindentation technique, enhanced by scanning probe microscopy, was used to measure cuticle stiffness of liveDrosophila melanogasterduring its larval, pupal, and early adult developmentin vivo. Stiffness was defined as the reduced elastic modulus (Er), which is a material property related to the elastic modulus.Erwas measured at the local contact while indenting the live sample at a constant loading rate using a spherical tip.Erwas derived from the resultant force‐displacement curves. Insect cuticle exhibits viscoelastic behavior. Constant loading rate quasistatic measurements were used so that the effects of viscosity and contact force adhesion introduced systematic measurement effects.Ervalues were as follows: larvae, mean (SE), 0.39 (0.01) MPa; the puparium without evidence of adult structures 15.43 (1.78) MPa; and the adult, measured in the puparium at the completion of metamorphosis, 4.37 (0.31) MPa. Thus, as expected, the puparium and adult cuticle were very much stiffer than larval cuticle. Results also indicated stiffness variation that related to developmental events. This study has shown that this quasistatic nanoindentation–scanning probe microscopy approach is a suitable method for analyzing live biological samples. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A: 633–642, 2003
Characterization of cellular carriers for use in injectable tissue‐engineering composites
Authors: McGlohorn Jonathan B. , Grimes Larry W. , Webster Shannon S. , Burg Karen J. L.
Published: August 2003

Injectable composite tissue‐engineering scaffolds are systems that incorporate individual cell carriers within a gel delivery matrix. This study assessed low‐temperature casting as a possible method to produce synthetic cell‐carrier beads. Porous poly‐L‐lactide beads were manufactured by low‐temperature casting. Two porogens, either glucose or sodium chloride, were incorporated into the beads and subsequently leached. Beads were seeded with primary culture aortic smooth muscle rat cells and were evaluated over a 13‐day period using a series of chemical, biochemical, and histological assays. Results indicate that low‐temperature casting is a viable technique to produce injectable beads on the order of 1.5–2.0 mm. The manufactured beads supported smooth muscle cell attachment and proliferation; where the beads formed with sodium chloride allowed enhanced proliferation. Differences in physical qualities, namely buoyancy and topography, were dependent on porogen selection and may provide a mechanism for bead and composite customization. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A: 441–449, 2003
A fibrin‐based arterial media equivalent
Authors: Grassl E. D. , Oegema T. R. , Tranquillo R. T.
Published: August 2003

We report here, with respect to collagen production and the mechanical properties of a fibrin‐based media equivalent (ME), on our efforts to optimize the culture conditions of neonatal SMCs entrapped in tubular fibrin gels. We examined several factors, including the concentration of fibrinolysis inhibitor, the cell source and initial number, the addition of TGF‐β and insulin to the culture medium, and the time in culture. We found that varying the concentration of ϵ‐aminocaproic acid (ACA), an inhibitor of fibrinolysis, did not affect the collagen production, but that lower concentrations resulted in a compromised physical integrity of the ME. While use of neonatal SMCs yielded superior results over adult SMCs, a higher initial cell number did not improve results. The addition of 1 ng/mL of TGF‐β to the medium increased the collagen content fourfold and the ultimate tensile strength (UTS) and modulus approximately tenfold after 3 weeks, while the addition of both TGF‐β and insulin improved collagen content sixfold and UTS and modulus almost 20‐fold. Additional TGF‐β (5 ng/mL) did not improve any of the properties measured, but additional time in culture did. Samples incubated for 6 weeks with TGF‐β and insulin contained about seven times the amount of collagen and had a three‐times higher UTS and modulus than did samples incubated for only 3 weeks. When compared to collagen MEs, the fibrin MEs compacted to a greater extent and were both stronger and stiffer when cultured under the same conditions, having after 6 weeks a tensile modulus and ultimate tensile strength similar to those of rat abdominal aorta. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A: 550–561, 2003
Ion release in stable hip arthroplasties using metal‐on‐metal articulating surfaces: A comparison between short‐ and medium‐term results
Authors: Savarino L. , Granchi D. , Ciapetti G. , Cenni E. , Greco M. , Rotini R. , Veronesi C. A. , Baldini N. , Giunti A.
Published: August 2003

The use of metallic heads articulating with metallic cups could solve the problem of polyethylene (PE) wear in total hip replacement (THR) with metal‐on‐PE bearings. A conspicuous release of metal ions from new models of metal‐on‐metal bearings has been found in the short‐term, but it is yet unclear whether the medium‐term corrosion rate is high or, on the contrary, it becomes negligible, because of the continuous surface finishing. Our purpose was to compare the serum ion values (nanograms per milliliter) in 15 patients with metal‐on‐metal stable prosthesis (Group A), in the short‐term (subgroup A1; mean follow‐up: 24 mo) and medium‐term (subgroup A2; mean follow‐up: 52 mo), in order to determine whether the ion release decreased with time of implant. Chromium (Cr), cobalt (Co), molybdenum (Mo) and aluminum (Al) were analyzed. Twenty‐two presurgical patients were used for comparison (Group B). The reference range was obtained from a population of 27 healthy subjects (Group C). Co and Cr levels in the medium‐term (subgroup A2) were not decreased in comparison with the short‐term values (subgroup A1) and were significantly higher (p < 0.001) than presurgical and reference values. Otherwise, Mo and Al concentrations were not significantly increased in comparison with reference values. In conclusion, despite the apparent advantage of metal‐on‐metal coupling, especially in younger patient populations, there is a major concern about the extent and duration of the relevant “internal” exposure to Cr and Co ions. This exposure should be carefully monitored, in order to clarify the biologic effects of ion dissemination and, consequently, to identify risks concerning long‐term toxicity of metals. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A: 450–456, 2003
Glucocorticoid‐treated sheep as a model for osteopenic trabecular bone in biomaterials research
Authors: Augat Peter , Schorlemmer Sandra , Gohl Christine , Iwabu Shohei , Ignatius Anita , Claes Lutz
Published: August 2003

The purpose of this study was to determine the alterations in ovine trabecular bone induced by a combination of ovariectomy and steroid treatment. Twenty‐four female skeletally mature Merino sheep were randomly assigned to ovariectomy alone (OVX), ovariectomy combined with glucocorticoid treatment for 6 months (OVX + GC), or no treatment (control). Biopsies of trabecular bone were harvested 6 and 12 months after the beginning of the study from the proximal tibia. The biopsies were scanned for apparent bone mineral density by quantitative computed tomography and were mechanically tested. Three‐dimensional bone reconstructions were obtained by micro‐computed tomography. Trabecular bone from the OVX + GC animals had a markedly reduced apparent bone mineral density (27% less than control), bone volume (34%), and elastic modulus (36%) at 6 months. At 12 months, the reductions in apparent bone mineral density (33%), bone volume (37%), and elastic modulus (62%) appeared to be even more pronounced. Ovariectomy alone did not result in a perceptible reduction in any parameter. The combination of ovariectomy and glucocorticoid treatment in sheep resulted in a successful induction of substantial loss of trabecular bone and thus may serve as a large‐animal model for osteopenic trabecular bone for the development and testing of orthopedic implants and techniques under osteoporotic conditions. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A: 457–462, 2003
Quadruple systems of the projective special linear group PSL(2,q), q ≡ 1 (mod 4)
Authors: Keranen M. S. , Kreher D. L. , Shiue P. J.‐S.
Published: August 2003

We determine the distribution of quadruple systems among the orbits of 4‐element subsets under the action of PSL(2,q) on the projective line when q ≡ 1 (mod 4). © 2003 Wiley Periodicals, Inc. J Combin Designs 11: 339–351, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jcd.10043
Graph homomorphisms through random walks
Authors: Daneshgar Amir , Hajiabolhassan Hossein
Published: August 2003

In this paper we introduce some general necessary conditions for the existence of graph homomorphisms, which hold in both directed and undirected cases. Our method is a combination of Diaconis and Saloff–Coste comparison technique for Markov chains and a generalization of Haemers interlacing theorem. As some applications, we obtain a necessary condition for the spanning subgraph problem, which also provides a generalization of a theorem of Mohar (1992) as a necessary condition for Hamiltonicity. In particular, in the case that the range is a Cayley graph or an edge‐transitive graph, we obtain theorems with a corollary about the existence of homomorphisms to cycles. This, specially, provides a proof of the fact that the Coxeter graph is a core. Also, we obtain some information about the cores of vertex‐transitive graphs. © 2003 Wiley Periodicals, Inc. J Graph Theory 44: 15–38, 2003
An application of the regularity lemma in generalized Ramsey theory
Authors: Sárközy Gábor N. , Selkow Stanley M.
Published: August 2003

Given graphs G and H, an edge coloring of G is called an (H,q)‐coloring if the edges of every copy of H ⊂ G together receive at least q colors. Let r(G,H,q) denote the minimum number of colors in a (H,q)‐coloring of G. In 9 Erdős and Gyárfás studied r(Kn,Kp,q) if p and q are fixed and n tends to infinity. They determined for every fixed p the smallest q (denoted by qlin) for which r(Kn,Kp,q) is linear in n and the smallest q (denoted by qquad) for which r(Kn,Kp,q) is quadratic in n. They raised the problem of determining the smallest q for which we have $r(K_{n,} K_{p,} q) = \left( {\matrix{n \cr 2 \cr } } \right) - 0(n^2 )$. In this paper by using the Regularity Lemma we show that if $q > q_{quad} + \left\lceil {{{\log _2 p} \over 2}} \right\rceil $, then we have $r(K_{n,} K_{p,} q) = \left( {\matrix{ n \cr 2 \cr } } \right) - 0(n^2 )$. © 2003 Wiley Periodicals, Inc. J Graph Theory 44: 39–49, 2003
Influence of oil‐in‐water emulsion characteristics on initial dynamic flavour release
Authors: Rabe Swen , Krings Ulrich , Berger Ralf G
Published: August 2003

Properties of oil‐in‐water (O/W) emulsions affecting initial dynamic flavour release were studied in real time considering mouth conditions. Aroma molecules from different chemical classes at concentrations typically present in beverages were used. The emulsion droplet diameter showed no significant influence on the dynamic flavour release. No barrier properties of the emulsifier were found, as the flavour release from equilibrated emulsions flavoured via either the oil phase or the aqueous phase showed no significant difference. Emulsifier concentrations above the critical micelle concentration did not influence the release. Even though the chemical composition of the lipids had considerable influence on flavour release, phase transition during equilibration from the liquid to the solid state insignificantly affected the initial dynamic release process. Copyright © 2003 Society of Chemical Industry
Chemical composition and physical properties of extruded snacks containing crab‐processing by‐product
Authors: Murphy Michael G , Skonberg Denise I , Camire Mary Ellen , Dougherty Michael P , Bayer Robert C , Briggs Jack L
Published: August 2003

The crab‐processing industries generate millions of pounds of by‐product annually, which results in a loss of edible product and presents a considerable waste disposal problem. The purpose of this research was to investigate the use of crab‐processing by‐product (CB) in the development of a calcium‐rich expanded snack. The specific objectives were to examine the effects of type of CB (wet or dry), feed composition and screw speed (150 or 250 rpm) on selected properties of extruded snacks. Product formulations consisting of 0–400 g kg−1 CB combined with corn meal and potato flakes were processed in a twin‐screw extruder. The resulting extrudates were analysed for proximate and mineral (calcium, sodium) composition, pH, water activity (aw), total plate count, bulk density, expansion ratio and colour. Both CB type and level of incorporation had significant effects (P < 0.05) on the calcium content, expansion ratio, bulk density and pH of the extrudates. Increasing the CB level resulted in increased calcium content (from 5.1 to 52.4 mg g−1) and pH (from 6.1 to 8.8). Screw speed had no significant effects (P > 0.05) on expansion ratio and bulk density. A high processing temperature (157 °C) and low aw resulted in undetectable microbial growth on the extrudates. This research demonstrates that ground crab‐processing by‐product can be successfully incorporated into an expanded snack product. Further research will evaluate consumer response to this novel value‐added product. Copyright © 2003 Society of Chemical Industry
Pectic polysaccharides during ripening of mango (Mangifera indica L)
Authors: Prasanna V , Yashoda HM , Prabha TN , Tharanathan RN
Published: August 2003

The content of pectin decreased from 2.0 to 0.7% fresh weight (FW) and there was a concomitant increase in free galacturonic acid from 36 to 168 mg% FW during ripening of mango. Ion exchange chromatography on DEAE/cellulose resolved the pectic fraction into seven distinct peaks, with all of them showing a drastic decrease in pectin content and molecular weight as fruit ripening progressed, which indicated significant depolymerisation in vivo. Fraction I appeared to be an arabinogalactan‐type polymer, while fractions II and III were heterogalacturonans containing more than 60% galacturonic acid. Hydrolases implicated in pectin depolymerisation were polygalacturonase (PG), pectin methyl esterase (PME), galactanase, arabinanase and β‐galactosidase. They all showed a climacteric peak in activity during ripening, except for PME which showed a continuous decrease in activity after an initial increase. These results are discussed in the light of fruit softening during ripening. Copyright © 2003 Society of Chemical Industry
Viscosity and emulsifying capacity in pota and octopus muscle during frozen storage
Authors: Ruiz‐Capillas C , Moral A , Morales J , Montero P
Published: August 2003

The functional quality of pota and octopus muscle during frozen storage for up to 12 months was evaluated periodically by determining viscosity and emulsifying capacity levels. In both species the effect on different anatomical locations (mantle and arms) in mature and young male and female individuals was studied. Apparent viscosity and emulsifying capacity levels were greater in octopus than in pota. While in pota a sharp decrease was observed in viscosity levels, falling to virtually nil, viscosity levels in octopus increased in the first 2 months and only slight decreases were observed at the end of storage. The change in emulsifying capacity, however, was quite similar in the two species, with not very sharp decreases. According to these results, emulsifying capacity measurement could be a suitable technique for showing the changes that occur in the muscle proteins of these species when they are stored frozen. No differences were observed by sex, but there were differences depending on the stage of maturity and anatomical location. Thus pota and octopus mantles present greater stability in frozen storage than the arms, and there is a tendency, although not always significant, that the mantles of young pota and octopus specimens are more stable in frozen storage than the mantles of adult individuals. Copyright © 2003 Society of Chemical Industry
Tourism demand modelling: some issues regarding unit roots, co‐integration and diagnostic tests
Authors: Narayan Paresh Kumar
Published: September 2003

This paper investigates the all important issue of diagnostic tests, including unit roots and cointegration, in the tourism demand modelling literature. The origins of this study lie in the apparent lack in the tourism economics literature of detail concerning the diagnostic test aspect. Study of this deficiency has suggested that previous literature on tourism demand modelling may be divided into two categories: the pre‐1995 and post‐1995 studies. It was found that the pre‐1995 and some post‐1995 studies have ignored unit root tests and co‐integration and, hence, are vulnerable to the so‐called ‘spurious regression’ problem. In highlighting the key diagnostic tests reported by post‐1995 studies, this paper contends that there is no need to report the autoregressive conditional heteroskedasticity (ARCH) test, which is applicable only to financial market analysis where the dependent variable is return on an asset. More generally, heteroskedasticity is not seen as a problem in time‐series data. However, the reporting of a greater than necessary range of diagnostic tests — some of which do not have any theoretical justification with regard to tourism demand analysis — does not diminish the precision of the results or the model. This paper should appeal to scholars involved in tourism demand modelling. Copyright © 2003 John Wiley & Sons, Ltd.
The impact of crime on tourist arrivals in Jamaica
Authors: Alleyne Dillon , Boxill Ian
Published: September 2003

This paper examines the relationship between tourist arrivals and changes in the crime rate in Jamaica over the period 1962–1999. In particular, it uses a transfer function to account for variations in total arrivals and arrivals from the European market, owing to changes in the crime rate. The transfer function allows for the modelling of the immediate and delayed effect of crime rates on tourist arrivals. The paper finds first that although crime rates have a negative impact on tourism arrivals in both markets, it is of greater concern in the European market. Secondly, the impact of crime in the overall market is relatively small, because of increased advertising and promotion and the growth of all‐inclusive hotels. Finally the level of crime, especially violent crime, has to be reduced, because although the number of crimes against tourists has declined, high violent crime rates tend to raise concerns among tourists seeking a destination. Copyright © 2003 John Wiley & Sons, Ltd.
A reliable congestion control mechanism for geocasting in mobile wireless networks
Authors: ElAarag Hala , Bassiouni Mostafa
Published: September 2003

In this paper, we present a reliable congestion control mechanism for geocasting in mobile wireless networks. Our protocol can be used as an extension to conventional multicasting protocols in order to overcome the problems associated with terminal mobility and the wireless environment. We present the architecture and implementation of the Multicast ACK Aggregation Method (MAAM). And test the performance of MAAM in various scenarios. Our simulation results show the efficiency and reliability of MAAM in wireless networks with high bit error rates. We further enhance the performance of MAAM by designing MAAM with local recovery (MAAM/LR). Copyright © 2003 John Wiley & Sons, Ltd.
Hoxa10 and Hoxd10 coordinately regulate lumbar motor neuron patterning
Authors: Lin Amy W. , Carpenter Ellen M.
Published: August 2003

The paralogous Hox genes Hoxa10 and Hoxd10 are expressed in overlapping domains in the developing lumbar spinal cord and surrounding mesoderm. Independent inactivation of these two genes alters the trajectory of spinal nerves and decreases the complement of motor neurons present in the lumbar spinal cord, whereas dual inactivation of these two genes has been shown to alter peripheral nerve growth and development in the mouse hindlimb. We have examined the organization and distribution of lumbar motor neurons in the spinal cords of Hoxa10/Hoxd10 double mutant animals. Double mutant animals have decreased numbers of lumbar motor neurons in both the medial and lateral motor columns. The anteroposterior position of the lumbar motor column is shifted caudally in double mutant animals, and the distribution of motor neurons is altered across individual spinal segments. Distinctions between classes of motor neurons based on positional specificity appear disrupted in double mutants. Double mutants also demonstrate abnormal spinal cord vasculature and altered kidney placement and size. Our observations suggest that Hoxa10 and Hoxd10 activity is required to specify the position of the lumbar motor column and to provide segmental specification and identity for the lumbar motor neurons. © 2003 Wiley Periodicals, Inc. J Neurobiol 56: 328–337, 2003
Neuroprotection by the steroids pregnenolone and dehydroepiandrosterone is mediated by the enzyme aromatase
Authors: Veiga Sergio , Garcia‐Segura Luis M. , Azcoitia Iñigo
Published: August 2003

Pregnenolone and dehydroepiandrosterone (DHEA) are sex hormone precursors and neuroprotective steroids. Effects of pregnenolone and DHEA may be in part mediated by their conversion to testosterone and by the consecutive conversion of testosterone to estradiol by the enzyme aromatase. This enzyme is induced in reactive astrocytes after different forms of neurodegenerative lesions and the resultant local production of estradiol in the brain has been shown to be neuroprotective. The participation of aromatase in the neuroprotective effect of pregnenolone and DHEA has been assessed in this study. The protective effect of different doses (12.5, 25, 50, and 100 mg/kg) of pregnenolone or DHEA, against systemic kainic acid (7 mg/kg b.w.), was assessed on hippocampal hilar neurons in gonadectomized Wistar male rats. To determine whether the neuroprotective effect of pregnenolone and DHEA was dependent on their conversion to estradiol, the aromatase inhibitor fadrozole (4.16 mg/mL) was administered using subcutaneous osmotic minipumps. The number of Nissl‐stained neurons in the hilus of the dentate gyrus of the hippocampal formation was estimated by the optical disector method. The administration of kainic acid resulted in a significant decrease in the number of hilar neurons compared to rats injected with vehicles. Pregnenolone and DHEA showed a dose‐dependent protective effect of hilar neurons against kainic acid. The administration of the aromatase inhibitor fadrozole blocked the neuroprotective effect of pregnenolone and DHEA. These findings suggest that estradiol formation by aromatase mediates neuroprotective effects of pregnenolone and DHEA against excitotoxic‐induced neuronal death in the hippocampus. © 2003 Wiley Periodicals, Inc. J Neurobiol 56: 398–406, 2003
Cathepsin B but not cathepsins L or S contributes to the pathogenesis of Unverricht‐Lundborg progressive myoclonus epilepsy (EPM1)
Authors: Houseweart Megan K. , Pennacchio Len A. , Vilaythong Alex , Peters Christoph , Noebels Jeffrey L. , Myers Richard M.
Published: August 2003

The inherited epilepsy Unverricht‐Lundborg disease (EPM1) is caused by loss‐of‐function mutations in the cysteine protease inhibitor, cystatin B. Because cystatin B inhibits a class of lysosomal cysteine proteases called cathepsins, we hypothesized that increased proteolysis by one or more of these cathepsins is likely to be responsible for the seizure, ataxia, and neuronal apoptosis phenotypes characteristic of EPM1. To test this hypothesis and to identify which cysteine cathepsins contribute to EPM1, we have genetically removed three candidate cathepsins from cystatin B‐deficient mice and tested for rescue of their EPM1 phenotypes. Whereas removal of cathepsins L or S from cystatin B‐deficient mice did not ameliorate any aspect of the EPM1 phenotype, removal of cathepsin B resulted in a 36–89% reduction in the amount of cerebellar granule cell apoptosis depending on mouse age. The incidence of an incompletely penetrant eye phenotype was also reduced upon removal of cathepsin B. Because the apoptosis and eye phenotypes were not abolished completely and the ataxia and seizure phenotypes experienced by cystatin B‐deficient animals were not diminished, this suggests that another molecule besides cathepsin B is also responsible for the pathogenesis, or that another molecule can partially compensate for cathepsin B function. These findings establish cathepsin B as a contributor to the apoptotic phenotype of cystatin B‐deficient mice and humans with EPM1. They also suggest that the identification of cathepsin B substrates may further reveal the molecular basis for EPM1. © 2003 Wiley Periodicals, Inc. J Neurobiol 56: 315–327, 2003
Significance and attributes of subpixel estimation on area‐based matching
Authors: Shimizu Masao , Okutomi Masatoshi
Published: September 2003

Area‐based matching and subpixel displacement estimation using similarity measures are common methods used in various fields. Subpixel estimation using parabola fitting over three points with their similarity measures is also a common method to increase matching resolution. However, such estimation can contain systematic error depending on image characteristics, the similarity function, and the fitting function used for subpixel estimation. In this paper, characteristics of subpixel estimation error were clarified using a simple analytical model. Although this model is quite simple, it allows us to make a theoretical analysis for general images without assuming any specific image pattern. Through this analysis, it has been shown that there are correct combinations of the similarity functions and the fitting functions. Also, the so‐called “pixel‐locking” effect, by which estimated positions tend to be biased toward integer values, has been explained. Finally, analyses were verified with an experiment using real images. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(12): 1–10, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10506
Self‐perceived psychological stress in relation to psychosocial factors and work in a random population sample of women
Authors: Jönsson Dagmar , Johansson Saga , Rosengren Annika , Lappas Georg , Wilhelmsen Lars
Published: August 2003

Objective

To investigate the relations between stress and other psychosocial factors, and to compare stress levels registered at 18 years' interval.

Methods

In 1980 1413 women aged 37 to 65 years were examined (81 per cent of a random population sample). In 1997 to 1998 909 of the women were re‐examined. Psychological stress was graded 1 to 6.

Results

Work‐related factors, i.e. employment including work leadership, demands of high concentration at work, dissatisfaction with work content and dissatisfaction with work environment were each independently associated with severe self‐perceived psychological stress in the 1980 survey (OR (95%CI) = 1.85(1.28–2.70), 1.55(1.11–2.16), 5.06(2.38–10.77) and 2.11(1.23–3.61)), respectively. Family‐related factors such as difficulties in agreeing with husband/cohabitant were also closely related to severe stress (OR (95%CI) = 3.39(1.07–10.75)). Other factors independently related to severe stress were smoking (OR (95%CI) = 1.42(1.03–1.98) and 2.40(1.24–4.65) at the first and second investigations respectively). Psychological stress was lower in physically active women (OR (95%CI) = 0.47(0.35–0.66) and 0.43(0.23–0.80) at the first and second investigations respectively). Blood pressure and serum cholesterol were lower in women at higher stress levels in several age groups. There was a general decrease of the self‐perceived stress level between the first and the second investigation. In women aged 55 to 64 years, however, the only age group that were available for analysis on both occasions, more severe stress was reported at the second investigation (13.8 versus 16.8 per cent; p < 0.0001).

Conclusions

Factors related to work conditions, as well as to family circumstances, were independently associated with psychological stress. Smoking was associated with higher stress levels, whereas leisure time physical activity was protective. Contrary to what might be expected blood pressure and to some extent serum cholesterol concentrations were lower at higher stress levels. Copyright © 2003 John Wiley & Sons, Ltd.
The AXH module: an independently folded domain common to ataxin‐1 and HBP1
Authors: de Chiara C. , Giannini C. , Adinolfi S. , de Boer J. , Guida S. , Ramos A. , Jodice C. , Kioussis D. , Pastore A.
Published: September 2003

Ataxin‐1 (ATX1), a human protein responsible for spinocerebellar ataxia type 1 in humans, shares a region of homology, named AXH module, with the apparently unrelated transcription factor HBP1. Here, we describe the first characterisation of the AXH module in terms of its structural properties and stability. By producing protein constructs spanning the AXH modules of ATX1 and HBP1 and by comparing their properties, we have identified the minimal region sufficient for forming independently folded units (domains). Knowledge of the AXH domain boundaries allows us to map many of the interactions of ATX1 with other molecules onto the AXH module. We further show that the AXH of ATX1 is a dimerisation domain and is able to recognise RNA with the same nucleotide preference previously described for the full‐length protein. AXH is therefore a novel protein–protein and RNA binding motif.
Negatively charged residues adjacent to IFM motif in the DIII–DIV linker of hNaV1.4 differentially affect slow inactivation
Authors: McCollum Isabelle J , Vilin Yuriy Y , Spackman Elizabeth , Fujimoto Esther , Ruben Peter C
Published: September 2003

The effects on slow inactivation (SI) of charge substitutions, neutralizations, and reversals were studied for the negatively charged residues D1309 and EE1314,15 surrounding the IFM motif in the DIII–DIV cytoplasmic linker – the putative fast inactivation particle – of human skeletal muscle voltage‐gated sodium channel (hNaV1.4). Changing aspartate (D) at position 1309 to glutamate (E) (substitution) did not strongly affect SI, whereas charge neutralization to glutamine (Q) and charge reversal to arginine (R) right‐shifted the midpoint of the steady‐state SI curve. Charge neutralization (D→Q) at position 1309 also reduced the apparent valence associated with SI. Glutamates (E) at positions 1314 and 1315 were similarly mutated. Charge reversal (EE→RR) right‐shifted the steady‐state SI curve and both reversal and substitution (EE→DD) reduced its apparent valence. Charge neutralization (EE→QQ) and reversal decreased the maximum probability of SI. These mutations also had differential effects on the rate of SI onset and recovery. These results suggest that charged residues in the DIII–DIV linker may interact with structures that control SI.
Differential localization of lipid phosphate phosphatases 1 and 3 to cell surface subdomains in polarized MDCK cells
Authors: Jia Yan-Jun , Kai Masahiro , Wada Ikuo , Sakane Fumio , Kanoh Hideo
Published: September 2003

Lipid phosphate phosphatases (LPPs) are integral membrane proteins with six transmembrane domains that act as ecto‐enzymes dephosphorylating a variety of extracellular lipid phosphates. Using polarized MDCK cells stably expressing human LPP1 and LPP3, we found that LPP1 was located exclusively at the apical surface whereas LPP3 was distributed mostly in the basolateral subdomain. We identified a novel apical sorting signal at the N‐terminus of LPP1 composed of F(2)DKTRL(7). In the case of LPP3, a dityrosine motif present in the second cytoplasmic portion was identified as basolateral targeting signal. Our work shows that LPP1 and LPP3 are equipped with distinct sorting signals that cause them to differentially localize to the apical vs. the basolateral subdomain, respectively.
Hyperbaric Compression in the Guinea Pig with Perilymph Fistula
Authors: Lindberg Paige E. , Parell G. Joseph , Gajewski Byron J. , Prevatt Angela R. , Antonelli Patrick J.
Published: September 2003

OBJECTIVE

The study goal was to evaluate the effects of hyperbaric therapy on the auditory and vestibular function of guinea pigs compromised by perilymph fistula (PLF).

METHODS

Twenty‐four pigmented guinea pigs underwent induction of bilateral eustachian tube dysfunction before the creation of a unilateral PLF. Half of the animals were randomly assigned to receive immediate hyperbaric compression treatment of 4 “dives” each. Hearing was tested electrocochleographically, and signs of vestibulopathy were recorded before and after compression.

RESULTS

After accounting for the effects of PLF, compression was not associated with significant hearing loss (P = 0.5411). Vestibulopathy was seen only in ears with PLF, and its incidence was similar for compression and noncompression groups.

CONCLUSION

Hyperbaric compression does not compromise auditory or vestibular function in guinea pig ears with experimental PLF.

SIGNIFICANCE

Our observations support the relative safety of recompression in patients with PLF.
Seven-Year Outcome Following Colles’ Type Distal Radial Fracture. A Comparison of Two Treatment Methods
Authors: YOUNG C. F. , NANU A. M. , CHECKETTS R. G.
Published: September 2003

Eighty-five patients were reviewed 7 years after prospective randomization to bridging external fixation or plaster immobilization for treatment of a Colles’ type distal radial fracture. The Gartland and Werley score showed that most patients in each group had an excellent or good outcome and patient satisfaction was comparable and high in both groups. The fixator group had significantly less radial shortening ( P < 0.05 ). Despite a high level of radiographic malunion (50%) overall function, range of movement and activities of daily living were not limited. Twenty-five per cent of patients had minor radiological signs of post-traumatic arthritis although only one patient was symptomatic. We conclude that, in the long term, external fixation of distal radius fractures does not confer an improved outcome when compared to plaster immobilization.
Classification of Secondary Shoulder Deformities in Obstetric Brachial Plexus Palsy
Authors: AL-QATTAN M. M.
Published: September 2003

Shoulder deformities are the most frequent sequelae of birth palsy. In this paper, previous classification systems for secondary shoulder deformities are reviewed and a new classification is offered.
Longitudinal Sliding of the Median Nerve in Patients with Carpal Tunnel Syndrome
Authors: EREL E. , DILLEY A. , GREENING J. , MORRIS V. , COHEN B. , LYNN B.
Published: September 2003

In nerve compression syndromes restricted nerve sliding may lead to increased strain, possibly contributing to symptoms. Ultrasound was used to examine longitudinal median nerve sliding in 17 carpal tunnel syndrome patients and 19 controls during metacarpophalangeal joint movement. Longitudinal movement in the forearm averaged 2.62 mm in controls and was not significantly reduced in carpal tunnel syndrome (CTS) patients (mean=2.20 mm). In contrast, CTS patients had a 40% reduction in transverse nerve movement at the wrist on the most, compared to least, affected side and nerve areas were enlarged by 34%. Normal longitudinal sliding in the patients indicates that nerve strain is not increased and will not contribute to symptoms.
Differences in Morphology, Cytoskeletal Architecture and Protease Production Between Zone II Tendon and Synovial Fibroblasts in vitro
Authors: RAGOOWANSI R. , KHAN U. , BROWN R. A. , MCGROUTHER D. A.
Published: September 2003

Fibroblast migration is an integral component of the processes resulting in the formation of restrictive adhesions in the injured tendon, especially in Zone II.

Pre-requisites for cell migration are an intact cytoskeleton and an ability to biochemically degrade the extra-cellular matrix. The relative characteristics of fibroblasts from the fibro-osseus sheath (SC), the tissue surrounding the tendon in Zone II, and the endotenon (TC) with respect to morphology, cytoskeletal structure and ability to produce matrix metalloproteinases (MMPs) 2 and 9 were compared in vitro.

It was found that SCs were larger in size and demonstrated greater amounts of intra-cellular alpha-smooth muscle actin (α-SMA) and intra-membranous vinculin. Filamentous actin (F-actin) fibres in SCs were more densely packed and concentrated, resulting in stress fibres. The SCs also produce greater amounts of MMP-2 and MMP-9 compared to TCs.

These observations imply that SCs play an active role in adhesion formation and should be specifically targeted to inhibit or treat tendon adhesions.