bluuebunny/crossref_metadata_2025 huggingface dataset:
Desflurane-induced Preconditioning Alters Calcium-induced Mitochondrial Permeability Transition
Authors: Piriou Vincent , Chiari Pascal , Gateau-Roesch Odile , Argaud Laurent , Muntean Danina , Salles Delphine , Loufouat Joseph , Gueugniaud Pierre-Yves , Lehot Jean-Jacques , Ovize Michel
Published: February 2004

Background

Recent investigations have focused on the pivotal role of the mitochondria in the underlying mechanisms volatile anesthetic-induced myocardial preconditioning. This study aimed at examining the effect of anesthetic preconditioning on mitochondrial permeability transition (MPT) pore opening.

Methods

Anesthetized open chest rabbits were randomized to one of four groups and underwent 10 min of ischemia, except for the sham 1 group (n = 12). Before this, they underwent a treatment period consisting of (1) no intervention (ischemic group; n = 12), (2) 30 min of desflurane inhalation (8.9% end-tidal concentration) followed by a 15-min washout period (desflurane group; n = 12), or (3) ischemic preconditioning (IPC group; n = 12). A second set of experiments was performed to evaluate the effect of a putative mitochondrial adenosine triphosphate-sensitive potassium channel antagonist, 5-hydroxydecanoate (5-HD). The animals underwent the same protocol as previously, plus pretreatment with 5 mg/kg 5-HD. They were randomized to one of five groups: the sham 2 group, receiving no 5-HD (n = 12); the sham 5-HD group (n = 12); the ischemic 5-HD group (n = 12), the desflurane 5-HD group (n = 12), and the IPC 5-HD group (n = 12). At the end of the protocol, the hearts were excised, and mitochondria were isolated. MPT pore opening was assessed by measuring the amount of calcium required to trigger a massive calcium release indicative of MPT pore opening.

Results

Desflurane and IPC group mitochondria needed a higher calcium load than ischemic group mitochondria (362 +/- 84, 372 +/- 74, and 268 +/- 110 microM calcium, respectively; P < 0.05) to induce MPT pore opening. The sham 1 and sham 2 groups needed a similar amount of calcium to trigger mitochondrial calcium release (472 +/- 70 and 458 +/- 90 microM calcium, respectively). 5-HD preadministration had no effect on sham animals (458 +/- 90 and 440 +/- 128 microM calcium without and with 5-HD, respectively) and ischemic group animals (268 +/- 110 and 292 +/- 102 microM calcium without and with 5-HD, respectively) but abolished the effects of desflurane on calcium-induced MPT pore opening (362 +/- 84 microM calcium without 5-HD vs. 238 +/- 96 microM calcium with 5-HD; P < 0.05) and IPC (372 +/- 74 microM calcium without 5-HD vs. 270 +/- 104 microM calcium with 5-HD; P < 0.05).

Conclusion

Like ischemic preconditioning, desflurane improved the resistance of the transition pore to calcium-induced opening. This effect was inhibited by 5-HD, suggesting a link between mitochondrial adenosine triphosphate-sensitive potassium and MPT.
Reduced Efficacy of Volatile Anesthetic Preconditioning with Advanced Age in Isolated Rat Myocardium
Authors: Sniecinski Roman , Liu Hong
Published: February 2004

Background

Ischemic preconditioning and anesthetic preconditioning (APC) are reported to decrease myocardial infarct size during ischemia-reperfusion injury. However, the beneficial effects of ischemic preconditioning have been shown to decrease with advancing age. Although the mechanisms of ischemic preconditioning and APC are thought to be similar, it is not known whether the beneficial effects of APC are also reduced in the aged myocardium.

Methods

Male Fischer 344 rats of three age groups (2-4, 10-12, and 20-24 months) were used. Hearts were Langendorff perfused. Six hearts in each age group were pretreated with 10 min of sevoflurane and a 5-min washout before 25 min of ischemia and 60 min of reperfusion. Six control hearts in each age group received no treatment before ischemia. Nuclear magnetic resonance was used to measure intracellular Na, intracellular Ca, and intracellular pH, respectively. Left ventricular developed pressure, creatine kinase, and infarct size were measured.

Results

Ischemia decreases intracellular pH and increases intracellular Na and intracellular Ca in all age groups. APC blunts the pH decreases in young adult and middle-aged rats, but not in aged rats. APC decreased intracellular Na and intracellular Ca accumulation during ischemia in young adult and middle-aged hearts. APC improved adenosine triphosphate recovery in young rats but not in aged rats. Creatine kinase and infarct sizes were significantly reduced and left ventricular developed pressure was improved with APC in the young adult and middle-aged groups but not the aged group.

Conclusions

The benefits of APC are significantly reduced with advanced age in an isolated rat heart model.
Sequential Effects of Increasing Propofol Sedation on Frontal and Temporal Cortices as Indexed by Auditory Event-related Potentials
Authors: Heinke Wolfgang , Kenntner Ramona , Gunter Thomas C. , Sammler Daniela , Olthoff Derk , Koelsch Stefan
Published: February 2004

Background

It is an open question whether cognitive processes of auditory perception that are mediated by functionally different cortices exhibit the same sensitivity to sedation. The auditory event-related potentials P1, mismatch negativity (MMN), and early right anterior negativity (ERAN) originate from different cortical areas and reflect different stages of auditory processing. The P1 originates mainly from the primary auditory cortex. The MMN is generated in or in the close vicinity of the primary auditory cortex but is also dependent on frontal sources. The ERAN mainly originates from frontal generators. The purpose of the study was to investigate the effects of increasing propofol sedation on different stages of auditory processing as reflected in P1, MMN, and ERAN.

Methods

The P1, the MMN, and the ERAN were recorded preoperatively in 18 patients during four levels of anesthesia adjusted with target-controlled infusion: awake state (target concentration of propofol 0.0 microg/ml), light sedation (0.5 microg/ml), deep sedation (1.5 microg/ml), and unconsciousness (2.5-3.0 microg/ml). Simultaneously, propofol anesthesia was assessed using the Bispectral Index.

Results

Propofol sedation resulted in a progressive decrease in amplitudes and an increase of latencies with a similar pattern for MMN and ERAN. MMN and ERAN were elicited during sedation but were abolished during unconsciousness. In contrast, the amplitude of the P1 was unchanged by sedation but markedly decreased during unconsciousness.

Conclusion

The results indicate differential effects of propofol sedation on cognitive functions that involve mainly the auditory cortices and cognitive functions that involve the frontal cortices.
Influence of Chronic Phenytoin Administration on the Pharmacokinetics and Pharmacodynamics of Vecuronium
Authors: Wright Peter M. C. , McCarthy Gerald , Szenohradszky Janos , Sharma Manohar L. , Caldwell James E.
Published: February 2004

Background

The duration of action of vecuronium is reduced in patients receiving phenytoin. In this study, the authors examined, simultaneously, the influence of phenytoin on both the pharmacokinetics and the pharmacodynamics of vecuronium.

Methods

This study was approved by the institutional review board of the University of California, San Francisco, and patients gave written informed consent. Twenty-two patients, 11 taking phenytoin and all scheduled to undergo prolonged neurosurgical procedures with general anesthesia, participated in the study. In 12 patients (6 phenytoin, 6 control), vecuronium was infused at 7.5 microg x kg(-1) x min(-1) until the first response (T1) of each train-of-four decreased by 50%; in the remaining 10 patients (5 phenytoin, 5 control), 200 microg/kg vecuronium was infused over 10 min. Arterial blood samples were drawn at intervals over the next 5-7 h. Plasma concentrations of vecuronium and 3-desacetylvecuronium were measured by capillary gas chromatography. Pharmacokinetic and pharmacodynamic modeling was used to characterize the disposition of vecuronium and patient responses to it in the two groups.

Results

Clearance was typically increased by 138% (95% confidence interval, 93-183%) in patients taking phenytoin. The effect of vecuronium was well described using a sigmoid Emax model. The concentration of vecuronium giving 50% twitch depression was increased 124% (45-202%) in patients taking phenytoin.

Conclusions

Chronic phenytoin therapy reduces the effect of vecuronium by mechanisms that include both increased vecuronium metabolism and reduced sensitivity of the patient to circulating concentrations of vecuronium.
Performance Evaluation of Two Published Closed-loop Control Systems Using Bispectral Index Monitoring
Authors: Struys Michel M. R. F. , De Smet Tom , Greenwald Scott , Absalom Anthony R. , Bingé Servaas , Mortier Eric P.
Published: February 2004

Background

Although automated closed-loop control systems may improve quality of care, their safety must be proved under extreme control conditions. This study describes a simulation methodology to test automated controllers and its application in a comparison of two published controllers for Bispectral Index (BIS)-guided propofol administration.

Methods

A patient simulator was developed to compare controllers. Using input scripts to dictate patient characteristics, target BIS values, and the time course of surgical events, the simulator continuously monitors the infusion pump under control and generates BIS values as a composite of modeled response to drug, perceived stimulation, and random noise. The simulator formats the output stream of BIS data as input to the controller under test to emulate the serial output of the actual BIS monitor. A published model-based controller and a classic proportional integral derivative controller were compared when using the BIS value as a controlled variable. Each controller was tested using a set of 10 virtual patients undergoing a fixed surgical profile that was repeated with BIS targets set at 30, 50, and 70. Controller performance was assessed using median (absolute) prediction error, divergence, wobble, and percentage time within BIS target range metrics.

Results

The median prediction error was significantly smaller for the proportional integral derivative controller than for the model-based controller. The median absolute prediction error was smaller for the model-based controller than for the proportional integral derivative controller for each BIS target, reaching statistical significance for targets 30 and 50.

Conclusions

When simulating closed-loop control of BIS using propofol, the use of a patient-individualized, model-based adaptive closed-loop system with effect site control resulted in better control of BIS compared with a standard proportional integral derivative controller with plasma site control. Even under extreme conditions, the modeled-based controller exhibited no behavioral problems.
Current Concepts of Hemostasis
Authors: Roberts Harold R. , Monroe Dougald M. , Escobar Miguel A. , Weiskopf Richard B.
Published: February 2004

The revised model of coagulation has implications for therapy of both hemorrhagic and thrombotic disorders. Of particular interest to anesthesiologists is the management of clotting abnormalities before, during, and after surgery. Most hereditary and acquired coagulation factor deficiencies can be managed by specific replacement therapy using clotting factor concentrates. Specific guidelines have also been developed for perioperative management of patients using anticoagulant agents that inhibit platelet or coagulation factor functions. Finally, recombinant factor VIIa has been used off-label as a hemostatic agent in some surgical situations associated with excessive bleeding that is not responsive to conventional therapy.
Digital cultural heritage projects in Europe: an overview of TRIS and the take‐up trial projects
Authors: Tariffi Flavio , Morganti Barbara , Segbert Monika
Published: February 2004

TRIS (trials support measure) is a European Commission (EC)‐funded activity involved with co‐ordinating 25 EC‐funded “take‐up trial projects” to increase their impact and exploit their results. The take‐up trial projects, all of them now completed, involved the application of new technologies in 80 cultural institutions in Europe and have contributed to cultural innovation. After introducing the general context of the EC’s cultural heritage sector within which TRIS and the take‐up trial projects have been funded, this article describes a selection of these projects, clustered according to their particular relevance to the world of museums, open‐air sites, libraries and archive institutions. The paper then provides an overview of the technologies with which the projects have experimented.
Force control for industrial applications using a fuzzy PI controller
Authors: Norberto Pires J. , Godinho Tiago , Araújo Ricardo
Published: February 2004

In this paper, a small revision on force control strategies is presented, stressing the implementation requirements of each strategy with the objective of clarifying the reasons of their poor practical utilization in industry. Furthermore, recognizing that direct force control approaches require system changes on actual robot control systems, which calls for manufacturer cooperation, an indirect force control approach is presented. The controller is introduced along with implementation description. The system is tested with an industrial deburring application that is also briefly introduced. Research experimental results of the proposed controller obtained in the laboratory, and experimental results obtained with the industrial deburring application are presented and discussed.
The impact of marketing/HR interactions on marketing strategy implementation
Authors: Chimhanzi Jacqueline
Published: February 2004

It is increasingly being recognised that cross‐unit working relationships have a key role to play in the successful implementation of marketing decisions. Although there is a substantial body of literature on marketing's interactions with other functions, particularly technical units such as R&D, within the context of the new product development (NPD) process, linkages between marketing and human resources (HR) have not been empirically investigated although they are widely advocated in both the marketing and HR management literatures. The conceptual model presented and tested in this paper focuses on the antecedents of effective marketing/HR interactions and posits successful marketing strategy implementation as an outcome of these. Results from a study of UK service organisations suggest that implementation effectiveness is affected negatively by conflict and positively by communication and specifically, interpersonal, not written. In turn, these interdepartmental dynamics are affected by senior management support, joint reward systems, and informal integration. A number of conclusions are drawn which have important implications for managers and researchers alike.
Sustained monopolistic business relationships
Authors: Humphries Andrew , Wilding Richard
Published: February 2004

Business‐to‐business relationships within sustained monopolies, such as those within UK defence procurement, have received scant attention by management researchers. This is unusual because under these market circumstances there appear to be few incentives to achieve mutually beneficial outcomes despite their strategic policy importance. This paper argues that an understanding of the monopolistic environment using a transaction cost economics theoretical framework and relationship marketing concepts provides an approach to solving this problem as well as testing aspects of these disciplines empirically in a novel area. This plan is supported by the results from a pilot study and the paper concludes by proposing a substantial research project to test this hypothesis in the UK defence procurement situation.
Market orientation: an antecedent to the industrial manufacturer's power
Authors: Enrique Bigné J. , Blesa Andreu , Küster Inés , Andreu Luisa
Published: February 2004

This study looks at the relationships between the market orientation of the manufacturer and the sources of his or her power over the distributor. The effect these power bases have on the distributor's satisfaction with the relationship is also analysed. The aricle offers the results of a study, conducted in the ceramic tile sector in Spain, aimed at measuring the market orientation of manufacturers, their power bases as perceived by their distributors, and the latter's satisfaction with the relationship. The results show that manufacturers' market orientation has a positive effect on their reward power but not on their referent power, nor on their power of coercion. However, the reward, expert and referent powers of the manufacturer have a positive effect on the distributor's satisfaction
Antecedents and outcomes of new product development speed
Authors: Menon Ajay , Lukas Bryan A.
Published: February 2004

The objective of this paper is to extend the study of new product development speed in the marketing discipline. The article outlines a conceptual framework to organize and guide future theoretical and empirical research. A set of propositions is developed which focus on the antecedents and outcomes of new product development speed germane to the discipline of marketing. The article discusses how both infrastructural factors (bureaucratic structure and adhocratic culture) and procedural factors (organizational control and interfunctional coordination) affect new product development speed. It also discusses the impact of new product development speed on performance factors internal to the organization (organizational learning and organizational stress). Research contributions and research directions are addressed.
Silence of the brands
Authors: Salzer‐Mörling Miriam , Strannegård Lars
Published: February 2004

Since the late 1980s, brands have gained centre stage in marketing and in the managerial discourse. From having been a mere marker that identifies the producer or the origin of a product, the brand is today increasingly becoming the product that is consumed. For the corporation, the brand is conceptualised as the essence of the firm, its most crucial “asset”. In the literature, branding is described as a process of expressing core values through the use of persuasive stories. By questioning the conception of brands as corporately managed stories, the article aims to re‐conceptualise branding as a process of aesthetic expression, where the conventional distinctions between senders and receivers become blurred. The paper looks into how brands have become depicted in the branding literature, and thereafter discusses the narrative and pictorial modes of communication. On the basis of this, the article finally discusses how images are used and reused in the joint construction of brands, thus challenging the idea of brands as stories crafted and controlled by the corporation.
Refinement and validation of a French in‐patient experience questionnaire
Authors: Labarère José , Fourny Magali , Jean‐Phillippe Vittoz , Marin‐Pache Stéphanie , Patrice François
Published: February 2004

The objective of this study was to check psychometric properties of a French‐language in‐patient experience questionnaire in a test sample different from the development sample. The questionnaire was sent out to 5,736 in‐patients, within two to four weeks of discharge from a teaching hospital of 2,200 beds. Overall 4,095 questionnaires (71.4 per cent) were returned. Of these, 3,879 questionnaires were analyzed. In principal component analysis, seven principal components accounted for 62.4 per cent of the total variance. Cronbach’s alpha coefficient ranged from 0.62 to 0.90, with the exception of the seventh scale (convenience scale, two items, Cronbach=0.39). The overall patient experience score increased with increasing patient age (except for patients older than 65), male sex, low education level, use of a single room, and prior stay in the department. It also differed with respect to patients’ behavioral intentions, answers to an overall satisfaction item, and open‐ended comments.
Reflow profile study of the Sn‐Ag‐Cu solder
Authors: Salam B. , Virseda C. , Da H. , Ekere N.N. , Durairaj R.
Published: February 2004

A study of the Sn‐Ag‐Cu lead‐free solder reflow profile has been conducted. The purpose of the work was to determine the Sn‐Ag‐Cu reflow profile that produced solder bumps with a thin intermetallic compound (IMC) layer and fine microstructure. Two types of reflow profiles were studied. The results of the experiment indicated that the most significant factor in achieving a joint with a thin IMC layer and fine microstructure was the peak temperature. The results suggest that the peak temperature for the Sn‐Ag‐Cu lead‐free solder should be 230°C. The recommended time above liquidus is 40 s for the RSS reflow profile and 50‐70 s for the RTS reflow profile.
Thermal fatigue cracking of surface mount conductive adhesive joints
Authors: Mo Zhimin , Lai Zonghe , Li Shiming , Liu Johan
Published: February 2004

Electrically conductive adhesives are considered to be strong candidates for replacing toxic lead‐based solders. The present work has focused on thermal fatigue cracking of isotropic conductive adhesive (ICA) joints. The initiation and propagation of cracks in the ICA joints were investigated with scanning electron microscopy. A linear elastic finite element analysis has been performed to analyse the stress distribution in the ICA joint and correlate the critical stress concentrations with the observed crack initiation sites. The effect of joint configurations on thermal stresses was also evaluated with numerical calculations.
Mapping Hsp47 binding site(s) using CNBr peptides derived from type I and type II collagen
Authors: Thomson Christy A. , Tenni Ruggero , Ananthanarayanan Vettai S.
Published: February 2004

As a crucial molecular chaperone in collagen biosynthesis, Hsp47 interacts with the nascent form as well as the mature triple‐helical form of procollagen. The location(s) of Hsp47 binding sites on the collagen molecule are, as yet, unknown. We have examined the substrate specificity of Hsp47 in vitro using well‐characterized CNBr peptide fragments of type I and type II collagen along with radiolabeled, recombinant Hsp47. Interaction of these peptides with Hsp47 bound to collagen‐coated microtiter wells showed several binding sites for Hsp47 along the length of the α1 and α2 chains of type I collagen and the α1 chain of type II collagen, with the N‐terminal regions showing the strongest affinities. The latter observation was also supported by the results of a ligand‐blot assay. Except for two peptides in the α2(I) chain, peptides that showed substantial binding to Hsp47 did so in their triple‐helical and not random‐coil form. Unlike earlier studies that used peptide models for collagen, the results obtained here on fragments of type I and type II collagen identify, for the first time, binding of Hsp47 to specific regions of the collagen molecule. They also point to additional structural requirements for Hsp47 binding besides the known preference for third‐position Arg residues and the triple‐helical conformation.
Structure‐based phenotyping predicts HIV‐1 protease inhibitor resistance
Authors: Shenderovich Mark D. , Kagan Ron M. , Heseltine Peter N.R. , Ramnarayan Kal
Published: February 2004

Mutations in HIV‐1 drug targets lead to resistance and consequent therapeutic failure of antiretroviral drugs. Phenotypic resistance assays are time‐consuming and costly, and genotypic rules‐based interpretations may fail to predict the effects of multiple mutations. We have developed a computational procedure that rapidly evaluates changes in the binding energy of inhibitors to mutant HIV‐1 PR variants. Models of WT complexes were produced from crystal structures. Mutant complexes were built by amino acid substitutions in the WT complexes with subsequent energy minimization of the ligand and PR binding site residues. Accuracy of the models was confirmed by comparison with available crystal structures and by prediction of known resistance‐related mutations. PR variants from clinical isolates were modeled in complex with six FDA‐approved PIs, and changes in the binding energy (ΔEbind) of mutant versus WT complexes were correlated with the ratios of phenotypic 50% inhibitory concentration (IC50) values. The calculated ΔEbind of five PIs showed significant correlations (R2 = 0.7–0.8) with IC50 ratios from the Virco Antivirogram assay, and the ΔEbind of six PIs showed good correlation (R2 = 0.76–0.85) with IC50 ratios from the Virologic PhenoSense assay. ΔEbind cutoffs corresponding to a four‐fold increase in IC50 were used to define the structure‐based phenotype as susceptible, resistant, or equivocal. Blind predictions for 78 PR variants gave overall agreement of 92% (kappa = 0.756) and 86% (kappa = 0.666) with PhenoSense and Antivirogram phenotypes, respectively. The structural phenotyping predicted drug resistance of clinical HIV‐1 PR variants with an accuracy approaching that of frequently used cell‐based phenotypic assays.
The characterization of mutant Bacillus subtilis adenylosuccinate lyases corresponding to severe human adenylosuccinate lyase deficiencies
Authors: Palenchar Jennifer Brosius , Crocco Jennifer M. , Colman Roberta F.
Published: February 2004

Adenylosuccinate lyase is a homotetramer that catalyzes two discrete reactions in the de novo synthesis of purines: the cleavage of adenylosuccinate and succinylaminoimidazole carboxamide ribotide (SAICAR). Several point mutations in the gene encoding the enzyme have been implicated in human disease. Bacillus subtilis adenylosuccinate lyase was used as a model system in which mutations were constructed corresponding to those mutations associated with severe human adenylosuccinate lyase deficiency. Site‐directed mutagenesis was utilized to construct amino acid substitutions in B. subtilis adenylosuccinate lyase; Met10, Ile123, and Thr367 were replaced by Leu, Trp, and Arg, respectively, and the altered enzymes were expressed in Escherichia coli. These purified enzymes containing amino acid substitutions were found to have substantial catalytic activity and exhibit relatively small changes in their kinetic parameters. The major deviations from the wild‐type‐like behavior were observed upon biophysical characterization. All of these enzymes with amino acid replacements are associated with marked thermal instability. I123W adenylosuccinate lyase exhibits notable changes in the circular dichroism spectra, and a native gel electrophoresis pattern indicative of some protein aggregation. T367R also exhibits alterations at the quarternary level, as reflected in native gel electrophoresis. Experimental results, combined with homology modeling, suggest that the altered enzymes are primarily structurally impaired. The enzyme instability was found to be lessened by subunit complementation with the wild‐type enzyme, under mild conditions; these studies may have implications for the in vivo behavior of adenylosuccinate lyase in heterozygous patients. Residues Met10, Ile123, and Thr367 appear to be located in regions of the enzyme important for maintaining the structural integrity required for a stable, functional enzyme.
Competitive binding of fatty acids and the fluorescent probe 1‐8‐anilinonaphthalene sulfonate to bovine β‐lactoglobulin
Authors: Collini Maddalena , D'Alfonso Laura , Molinari Henriette , Ragona Laura , Catalano Maddalena , Baldini Giancarlo
Published: February 2004

The use of spectroscopy in the study of fatty acids binding to bovine β‐lactoglobulin (BLG) appears to be a difficult task, as these acid compounds, assumed as the protein natural ligands, do not exhibit favorable optical response such as, for example, absorption or fluorescence. Therefore, the BLG fatty‐acid equilibrium has been tackled by exploiting the competition between fatty acids and ANS, a widely used fluorescent hydrophobic probe, whose binding sites on the protein have been characterized recently. Two lifetime decays of the ANS–BLG complex have been found; the longer one has been attributed to the internal binding site and the shorter one to the external site. At increasing fatty acids concentration, the fractional weight associated with ANS bound to the internal site drops, in agreement with a model describing the competition of the dye with fatty acids, whereas the external site occupancy appears to be unaffected by the fatty acids binding to BLG. This model is supported by docking studies. An estimate of the acid‐binding affinities for BLG has been obtained by implementing the fitting of the bound ANS intensities with a competitive binding model. A relevant dependence has been found upon the solution pH, in the range from 6 to 8, which correlates with the calyx accessibility modulated by the conformation of the EF loop. Fatty acids with longer aliphatic chains (palmitate and laurate) are found to display larger affinities for the protein and the interaction free energy nicely correlates with the number of contacts inside the protein calyx, in agreement with docking simulations.
Exploring the conformational space of membrane protein folds matching distance constraints
Authors: Faulon Jean‐Loup , Sale Ken , Young Malin
Published: February 2004

Herein we present a computational technique for generating helix‐membrane protein folds matching a predefined set of distance constraints, such as those obtained from NMR NOE, chemical cross‐linking, dipolar EPR, and FRET experiments. The purpose of the technique is to provide initial structures for local conformational searches based on either energetic considerations or ad‐hoc scoring criteria. In order to properly screen the conformational space, the technique generates an exhaustive list of conformations within a specified root‐mean‐square deviation (RMSD) where the helices are positioned in order to match the provided distances. Our results indicate that the number of structures decreases exponentially as the number of distances increases, and increases exponentially as the errors associated with the distances increases. We also found the number of solutions to be smaller when all the distances share one helix in common, compared to the case where the distances connect helices in a daisy‐chain manner. We found that for 7 helices, at least 15 distances with errors up to 8 Å are needed to produce a number of solutions that is not too large to be processed by local search refinement procedures. Finally, without energetic considerations, our enumeration technique retrieved the transmembrane domains of Bacteriorhodopsin (PDB entry1c3w), Halorhodopsin (1e12), Rhodopsin (1f88), Aquaporin‐1 (1fqy), Glycerol uptake facilitator protein (1fx8), Sensory Rhodopsin (1jgj), and a subunit of Fumarate reductase flavoprotein (1qlaC) with Cα level RMSDs of 3.0 Å, 2.3 Å, 3.2 Å, 4.6 Å, 6.0 Å, 3.7 Å, and 4.4 Å, respectively.
The effect of dexamethasone on human mucin 1 expression and antibody‐dependent complement sensitivity in a prostate cancer cell line in vitro and in vivo
Authors: Imai Masaki , Hwang Hee‐Young , Norris James S. , Tomlinson Stephen
Published: February 2004

Dexamethasone has been shown to up‐regulate human mucin 1 (MUC1) expression in certain types of cancer cell lines in vitro, suggesting that this gluocorticoid may enhance MUC1‐based immunotherapies. Here we investigated the effect of dexamethasone on MUC1 expression in the DU145 human prostate cancer cell line in terms of antibody‐mediated complement‐dependent cell lysis. Cells treated with 1 × 10−8 m dexamethasone in vitro expressed maximal levels of MUC1 after 6 days, with an approximately 3‐fold increase over MUC1 levels on untreated cells. DU145 cells were highly resistant to lysis by anti‐MUC1 antibody and complement, and their susceptibility to antibody and complement was unaffected by dexamethasone treatment. However, dexamethasone also induced expression of the complement inhibitor decay accelerating factor (DAF) on DU145 cells. Blocking or overcoming the function of DAF resulted in enhanced complement‐dependent lysis of dexamethasone‐treated cells with anti‐MUC1 antibodies, indicating that the failure of dexamethasone to enhance the complement susceptibility of DU145 cells was caused by the up‐regulated expression of DAF. We also investigated MUC1 expression in vivo and found that MUC1 expression was significantly up‐regulated on tumour cells isolated from immune‐deficient mice that had been injected with dexamethasone. However, in contrast to in vitro data, there was no difference between the levels of DAF expressed on tumour‐derived DU145 cells isolated from either phosphate buffered saline (PBS)‐treated or dexamethasone‐treated mice, and tumour cells isolated from dexamethasone‐treated mice were more sensitive to complement‐mediated lysis. In the broad context of immunotherapy, the in vivo data support the use of dexamethasone as an adjunct treatment. Up‐regulated DAF expression would not be a favourable outcome of dexamethasone treatment in terms of complement‐dependent antibody therapy, but the in vivo data caution against extrapolation of in vitro data with regard to the modulation of complement inhibitors reported here and elsewhere.
Anthropological Perspectives on the Trafficking of Women for Sexual Exploitation
Authors: Long Lynellyn D.
Published: February 2004

Abstract The sexual exchange of girls and women embodies deep cultural practices and is historically embedded in many family and kinship systems. Contemporary trafficking operations transform traditional bride wealth and marriage exchanges (prestations) by treating women's sexuality and bodies as commodities to be bought and sold (and exchanged again) in various Western capitals and Internet spaces. Such operations are also global with respect to scale, range, speed, diversity, and flexibility. Propelling many trafficking exchanges are political economic processes, which increase the trafficking of women in times of stress, such as famine, unemployment, economic transition, and so forth. However, the disparity between the global market operations, which organize trafficking, and the late nineteenth century social/public welfare system of counter‐trafficking suggests why the latter do not effectively address women's risks and may even expose them to increased levels of violence and stress. Drawing on historical accounts, anthropological theory, and ethnographic work in Viet Nam and Bosnia and Herzegovina, this essay examines how specific cultural practices embedded in family and kinship relations encourage and rationalize sexual trafficking of girls and young women in times of stress and dislocation. The essay also analyses how technologies of power inform both trafficking and counter‐trafficking operations in terms of controlling women's bodies, sexuality, health, labour, and migration. By analysing sexual trafficking as a cultural phenomenon in its own right, such an analysis seeks to inform and address the specific situations of girls and young women, who suffer greatly from the current migration regimes.
The Irregular Migrant as Homo Sacer: Migration and Detention in Australia, Malaysia, and Thailand
Authors: Rajaram Prem Kumar , Grundy‐Warr Carl
Published: February 2004

Abstract This paper looks at aspects of the detention of irregular migrants in Australia, Malaysia, and Thailand. The principle intention of the paper is to study detention of irregular migrants as a means of understanding politics and how notions of political participation and of sovereignty are affected by the detention of certain sorts of individual. What does the identification of certain “forms of life” to be detained say about the political norms of different societies? The conduit for this examination will be the Italian philosopher Giorgio Agamben's concept of homo sacer. Homo sacer is a term Agamben extrapolates from “ancient Roman law”. It denotes a naked or bare life that is depoliticized. Homo sacer is the excess of processes of political constitution that create a governable form of life. Homo sacer is thus exempt or excluded from the normal limits of the state. At the same time, however, homo sacer is not simply cast out but is held in particular relation to the norm: it is through the exclusion of the depoliticized form of life that the politicized norm exists. This essay seeks to contextualize aspects of Agamben's argument by looking at detention as a form of exclusion in three different contexts.
The Child Care Arrangements of Preschool‐Age Children in Immigrant Families in the United States
Authors: Brandon Peter D.
Published: February 2004

This study examined the child care arrangements of children in immigrant families. Using data from the Survey of Income and Program Participation (SIPP), the study found great diversity in the child care arrangements of children according to their nativity status. Children in immigrant families, especially those in low‐income immigrant families, were found less likely to use centre‐based child care. Mexican, Asian, and other Hispanic children are also less likely to use centre‐based child care. Because quality centre‐based child care has been shown to benefit preschool‐age children and help prepare them for school, both scholastically and psychologically, less use of centre‐based child care among children in immigrant families compared to children in non‐immigrant families is a potentially troubling finding. Public policies promoting greater access to and more use of centre‐based child care, especially for low‐income immigrant families and two‐parent immigrant families, may make a significant difference to their children's long‐term adaptation, and their children's school readiness and achievement.
Light microscopy and computer three‐dimensional reconstruction of the blood capillaries of the enamel organ of rat molar tooth germs
Authors: Cerri Paulo Sérgio , De Faria Flávio Paulo , Villa Ricardo Gazoni , Katchburian Eduardo
Published: February 2004

We performed a light microscope and a computer three‐dimensional reconstruction study of serial sections of the molar enamel organ of 3‐ and 5‐day‐old rats perfused with Indian ink through the arterial system. The tooth germs were fixed in Bouin's solution, embedded in paraffin, sectioned and stained with haematoxylin and eosin. For the three‐dimensional reconstruction, light micrographs of the serial sections were digitized, and aligned using the serial EM Align software downloaded from http://synapses.bu.edu/tools/. After alignment, the boundaries of the India‐ink‐filled blood vessels were manually traced with a mouse using the software IGL trace (version 1.26b), also downloaded from the above website. After tracing, a three‐dimensional representation of the blood vessel contours was generated in a VRML format and visualized with the help of the software Cortona Web3D viewer (version 4.0) downloaded from http://www.parallelgraphics.com/products/cortona/. Our results showed that in regions where ameloblasts are polarized the capillaries are arranged in three distinct levels: (1) penetrating and leaving capillaries in relation to the outer enamel epithelium; (2) capillaries crossing and branching inside the stellate reticulum; and (3) capillaries branching and anastomosing profusely within the stratum intermedium, thereby forming an extensive capillary plexus intimately associated with the cells of the stratum intermedium. The existence of a conspicuous capillary plexus intermingled with cells of the stratum intermedium, as shown in our results, suggests that some molecules produced by cells of the stratum intermedium could be released into the capillary plexus and thereafter carried to the dental follicle.
Aromatase immunolocalization in human ductuli efferentes and proximal ductus epididymis
Authors: Carpino A. , Romeo F. , Rago V.
Published: February 2004

Cytochrome P450 aromatase is a terminal enzyme that catalyses the conversion of androgens into oestrogens. This study investigated the immunohistochemical localization of aromatase in human efferent ductules and proximal ductus epididymis using a mouse anti‐human monoclonal P450arom IgG as primary antibody and a goat anti‐mouse biotinylated IgG as secondary antibody. A strong immunoreaction was observed in the epithelial cell cytoplasm of both ductuli efferentes and proximal ductus epididymis, whereas the smooth muscle cells were immunonegative in the two regions. The results show, for the first time in humans, that epithelial cells of ductuli efferentes and proximal caput epididymis express aromatase, suggesting that locally produced oestrogens may have a role in epididymal function.
The Chinese Visible Human (CVH) datasets incorporate technical and imaging advances on earlier digital humans
Authors: Zhang Shao‐Xiang , Heng Pheng‐Ann , Liu Zheng‐Jin , Tan Li‐Wen , Qiu Ming‐Guo , Li Qi‐Yu , Liao Rong‐Xia , Li Kai , Cui Gao‐Yu , Guo Yan‐Li , Yang Xiao‐Ping , Liu Guang‐Jiu , Shan Jing‐Lu , Liu Ji‐Jun , Zhang Wei‐Guo , Chen Xian‐Hong , Chen Jin‐Hua , Wang Jian , Chen Wei , Lu Ming , You Jian , Pang Xue‐Li , Xiao Hong , Xie Yong‐Ming , Cheng Jack Chun‐Yiu
Published: February 2004

We report the availability of a digitized Chinese male and a digitzed Chinese female typical of the population and with no obvious abnormalities. The embalming and milling procedures incorporate three technical improvements over earlier digitized cadavers. Vascular perfusion with coloured gelatin was performed to facilitate blood vessel identification. Embalmed cadavers were embedded in gelatin and cryosectioned whole so as to avoid section loss resulting from cutting the body into smaller pieces. Milling performed at −25 °C prevented small structures (e.g. teeth, concha nasalis and articular cartilage) from falling off from the milling surface. The male image set (.tiff images each of 36 Mb) has a section resolution of 3072 × 2048 pixels (∼170 µm, the accompanying magnetic resonance imaging and computer tomography data have a resolution of 512 × 512, i.e. ∼440 µm). The Chinese Visible Human male and female datasets are available at http://www.chinesevisiblehuman.com. (The male is 90.65 Gb and female 131.04 Gb). MPEG videos of direct records of real‐time volume rendering are at: http://www.cse.cuhk.edu.hk/~crc
Complexity of Family Life Among the Low‐Income and Working Poor: Introduction to the Special Issue
Authors: Dyk Patricia Hyjer
Published: February 2004

Like all families, low‐income and working‐poor families need economic stability, safety, good health, and engagement in the larger community. However, the complexity of their lives is greatly impacted by limited economic resources. Three primary themes are explored by the 12 articles in this special issue: competing stressors and tensions, effective parenting, and economic stability and financial decision making. Key findings and program and policy implications identified by each set of authors are discussed. This body of work provides research‐based practice and policy suggestions to guide future efforts in partnering with families to strengthen their families and communities for successful enhancement of child well‐being.
How has a shortage of census and geological information impeded the regularization of artisanal and small‐scale mining?
Authors: Hilson Gavin , Maponga Oliver
Published: February 2004

There is growing consensus that a combination of laissez‐faire policies, ad hoc regulation and debilitating support services has perpetuated socio‐economic and environmental deterioration in the artisanal and small‐scale mining (ASM) industry. However, a lack of anthropological and geological information on ASM prevents many governments both from improving the policy environment of the industry, and from providing more robust extension services to its operators. This article aims to examine more precisely how a deficiency of baseline census and geological data has inhibited industry formalization and undermined many of the measures implemented to address pressing problems at ASM sites. Specifically, it is argued that insufficient knowledge of artisanal mining populations — including their demographic structure — and of areas suitable for ASM activities affects the ability of a government to regularize, as well as to improve, the organization of this largely informal sector of industry. Case studies of Ghana and Zimbabwe are used to illustrate how the undertaking of low‐budget projects in areas of geological prospecting and population analysis could improve the efficiency of ASM assistance.
Thermoregulatory strategies in two closely related sympatric Scarabaeus species (Coleoptera: Scarabaeinae)
Authors: Verdú José R. , Díaz Alfonso , Galante Eduardo
Published: February 2004

Abstract.  The thermoregulation strategies of Scarabaeus sacer L. and Scarabaeus cicatricosus Lucas were studied in the Doñana National Park, Spain. In this area, both species coexist, showing the same habitat and food preferences. However, S. cicatricosus is active during warmer parts of the day compared to S. sacer. Both species thermoregulate their thoracic temperature but, whereas the abdomen of S. sacer is a passive thermal window, S. cicatricosus actively thermoregulates abdominal temperature by increasing heat transfer from the thorax to the abdomen at high Ta values. In the case of S. sacer, their endothermy indicates an adaptive capacity to thorax heat retention, as occurs mainly in winter‐flying insects. This mechanism, possibly related to the aerodynamic flight posture in Scarabaeinae, could be an effective barrier to retard the rate of abdominal heat loss during flight. This endothermic strategy makes flight difficult at higher temperatures, although it allows flight during cooler periods of the day. On the other hand, S. cicatricosus showed a different adaptive behaviour to S. sacer. In this case, a significant decrease in abdominal heat loss at higher ambient temperatures would indicate a decrease in heat transfer from the thorax to the abdomen, as occurs in some desert and semiarid insects. This ‘heat exchanger’ mechanism observed in S. cicatricosus could be due to the irregular posture adopted during flight, with the posterior legs clearly extended and separate from the body. This behaviour increases turbulence and convective cooling, favouring exposure of the soft abdominal tergal cuticle and, subsequently, water loss. Thus, for S. cicatricosus, the well‐adapted ‘heat exchanger’ permits flight during periods of the day when temperatures would possibly be lethal for those species with high endothermy. From an adaptive viewpoint, these mechanisms of thermoregulation may explain how both closely‐related sympatric species respond in different ways to environmental temperature, favouring their coexistence.