bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling Cohesive Cracks with Meshless Method
Authors: Wu S. , Fang S.
Published: February 2009

We present a discrete rotating crack method embedded in the elementfree Galerkin method. The crack is represented by discrete cohesive crack segments only passing through nodes. The discrete crack segments are introduced when the tensile strength in the material is exceeded and the crack segments are oriented perpendicular to the direction of the maximum principal stress. The orientation of the crack segments are rotated when directional changes in the maximum principal stress occur. It will be shown that fixed crack models lead to over-smearing the crack and too stiff responses of the system. The advantage of this method is that no representation of the crack surface is needed.
Morphological Fractal Dimension Versus Power-law Exponent in the Scaling of Damaged Media
Authors: Carpinteri Alberto , Lacidogna Giuseppe , Niccolini Gianni , Puzzi Simone
Published: February 2009

Fractal Geometry has been widely used for the description of irregular phenomena in various scientific fields recently. In the subjects concerning fracture system characterization, fractals represent the fracture surfaces in two or 3D problems. In the last few years the fractal geometry of crack networks in damaged materials has been statistically characterized by two power laws, respectively, describing the spatial distribution of crack barycenters, and the crack length distribution. In this article, we explore the potential of the latter power-law. Merely using such statistical model to describe the population of cracks, besides providing a theoretical basis for explaining lower limits to the b-value both in seismicity and in acoustic emission (AE) tests, we find a simple relation between b and the fractal dimension D of the crack network. As a result, the b-value analysis in AE monitoring tests permits evaluation of the dimension D of the damaged domain. This method of evaluating D is herein applied to a concrete specimen in compression, subjected to AE monitoring, loaded up to failure. In this test, the characterization of the fracture process through analysis of AE signals emerging from the growing cracks has been performed in a post-processing environment, using two different procedures. In fact, besides the two-point correlation algorithm introduced by Grassberger and Procaccia, the damage process has been evaluated through the b-value analysis. Both procedures make it possible to evaluate the dimension D of the damaged domain, i.e., the fractal dimension of the crack network. The obtained results are consistent with our understanding of damage phenomenon.
Laboratory Evaluation of Antiphospholipid Antibodies in Patients With Venous Thromboembolism
Authors: Hirmerova J. , Ulcova-Gallova Z. , Seidlerova J. , Filipovsky J. , Bibkova K. , Micanova Z. , Mayer O.
Published: February 2009

The objective of our study was to evaluate the significance of extended antiphospholipid profile in patients with venous thromboembolism without any systemic autoimmune disease. In 140 patients (age 18-69 years; 47.1% men) with venous thromboembolism and 136 control participants we tested anticardiolipin antibodies, anti-beta 2 glycoprotein I (anti-β2-GPI) and also non-criteria antiphospholipid antibodies: antiphosphatidic acid, antiphosphatidylethanolamine, antiphosphatidylglycerol, antiphosphatidylinositol, antiphosphatidylserine. Commercial and in-house enzyme-linked immunosorbent assays were used. The antibodies with significantly higher prevalence in patients (compared to controls) were: immunoglobulin (Ig) M-anticardiolipin antibodies (12.9%; P = 0.035), IgG-anti-β2-GPI (16.4%; P = 0.0032), IgM-antiphosphatidylethanolamine (14.3%; P = 0.014). In most cases, these three antibodies did not overlap. In conclusion, of non-criteria antiphospholipid antibodies, only antiphosphatidylethanolamine were significantly more prevalent in patients with venous thromboembolism, with only minor overlapping with the criteria antiphospholipid antibodies. Our results suggest the possible utility of searching for antiphosphatidylethanolamine in the clinical suspicion of antiphospholipid syndrome and the absence of criteria antiphospholipid antibodies.
Flow Cytometric Investigation of CD40-CD40 Ligand System in Preeclampsia and Normal Pregnancy
Authors: Lukanov Tzvetan Hristoforov , Bojinova Svetla Ivanova , Popova Vanya Slavcheva , Emin Alkan Levha , Veleva Galina Lubomirova , Gecheva Svetla Penkova , Konova Emiliana Ilieva
Published: February 2009

Our aim was to investigate the CD40-CD40 ligand system in preeclamptic women. We also studied CD62P and platelet—monocyte aggregates, which have been closely linked to the CD40—CD40L system. Platelet expression of CD40L and CD62P and expression of CD40 on monocytes and platelet—monocyte aggregates were determined by flow cytometry in whole blood from 23 preeclamptic women, 23 normotensive pregnant women, and 23 nonpregnant women. The preeclamptic women showed a significant increase in CD40L and CD62P on platelets and in CD40 on monocytes when compared with normotensive pregnant women and nonpregnant women (all P < .001). There was a significant increase in platelet—monocyte aggregates in preeclamptic women (P < .001) and normotensive pregnant women (P = .003) compared with nonpregnant women. Preeclampsia is associated with activation of the CD40—CD40L system. The activation of this system may contribute to the development or maintenance of the proinflammatory and prothrombotic milieu found in preeclampsia.
Introducing Systems Biology for Nursing Science
Authors: Founds Sandra A.
Published: February 2009

Systems biology expands on general systems theory as the ``omics'' era rapidly progresses. Although systems biology has been institutionalized as an interdisciplinary framework in the biosciences, it is not yet apparent in nursing. This article introduces systems biology for nursing science by presenting an overview of the theory. This framework for the study of organisms from molecular to environmental levels includes iterations of computational modeling, experimentation, and theory building. Synthesis of complex biological processes as whole systems rather than isolated parts is emphasized. Pros and cons of systems biology are discussed, and relevance of systems biology to nursing is described. Nursing research involving molecular, physiological, or biobehavioral questions may be guided by and contribute to the developing science of systems biology. Nurse scientists can proactively incorporate systems biology into their investigations as a framework for advancing the interdisciplinary science of human health care. Systems biology has the potential to advance the research and practice goals of the National Institute for Nursing Research in the National Institutes of Health Roadmap initiative.
The Relationship Between Meaning of Working and Socioeconomic Transformations: The Case of Post-Communist Russia
Authors: Ardichvili Alexandre
Published: February 2009

The problem and the solution. This article discusses how the meaning of working is changing in Russia as a result of rapid socioeconomic transformations that started after the breakup of the Soviet Union. Results of the review of academic books and articles related to work values and meaning of working published by Russian and Western scholars are presented.The article introduces three stages of socioeconomic transformation and discusses the link between these stages and the changes in meaning of working dimensions, such as centrality of work, valued work outcomes, and attachment to work.
The Adoption and Diffusion of an NHRD Standard: A Conceptual Framework
Authors: Murphy Aileen , Garavan Thomas N.
Published: February 2009

This article proposes a conceptual framework to explain the adoption and diffusion of a national human resource development (NHRD) standard. NHRD standards are used by governments to promote training and development in organizations and increase the professionalization of practices used by organizations. Institutional theory suggests that adoption and diffusion of HRD practices can be explained using a number of institutional concepts such as structural equivalence, social cohesion, and normative and mimetic isomorphism. Social cohesion and structural equivalence create normative and mimetic pressure, which results in increased adoption and diffusion. We highlight other organizational characteristics that explain adoption and diffusion, and also the implications for both theory and research.
Protective Effect of an Extract of Emblica officinalis Against Radiation-Induced Damage in Mice
Authors: Jindal Archana , Soyal Dhanraj , Sharma Abhilasha , Goyal P.K.
Published: February 2009

The radioprotective effect of Emblica officinalis extract (EOE) was studied in mice. Swiss albino mice were exposed to γ rays (5 Gy) in the absence (control) or presence (experimental) of EOE, orally 100 mg/kg body weight, once daily for 7 consecutive days. A specimen of small intestine (jejunum) was removed from the mice and studied at different autopsy intervals from 12 hours to 30 days. In control animals, crypt cell population, mitotic figures, and villus length were markedly reduced on day 1; these later started to increase progressively but did not attain the normal level even at the last autopsy interval. The animals receiving EOE prior to irradiation had a higher number of crypt cells and mitotic figures when compared with non-drug-treated control at all the autopsy intervals. Irradiation of animals resulted in a dose-dependent elevation in lipid peroxidation and a reduction in glutathione as well as catalase concentration in the intestine at 1 hour post-irradiation. In contrast, EOE treatment before irradiation caused a significant depletion in lipid peroxidation and elevation in glutathione and catalase levels.
Influence of hot rolling and heat treatment on structure and properties of HSLA steel explosively clad with austenitic stainless steel
Authors: Rao N. Venkateswara , Sarma D. S. , Nagarjuna S. , Reddy G. Madhusudhan
Published: February 2009

The present work aims at studying structure–property correlations in an explosively clad HSLA steel with austenitic stainless steel of AISI 304L grade. The clad plate was subjected to hot rolling followed by a quenching and tempering treatment to achieve better mechanical properties in the base plate. Optical microscopy studies revealed that the interface between the two steels was wavy in the as clad plate and the waviness decreased substantially due to hot rolling. Subsequent heat treatment has not shown any significant effect either. The base plate had tempered martensite/bainite structure in as clad or heat treated conditions and ferrite-pearlite-bainite structure in hot rolled condition. The grains were finer and elongated near the interface. The stainless steel exhibited equiaxed grain structure in as clad, hot rolled or heat treated plates. Tensile properties and charpy impact energy of the base plate were lowered due to hot rolling and then increased substantially due to heat treatment. The microhardness was observed to be a maximum at the bond interface for all three conditions studied. The shear bond strength was the highest in the as clad condition and decreased for the rolled as well as heat treated conditions. Scanning electron microscopy fractography on shear bond specimens revealed the presence of predominantly equiaxed dimples with few regions of rubbed fracture. Quantitative electron probe microanalysis across the bond interface indicated linear change in concentrations of nickel, chromium and manganese between the levels appropriate to the clad layer and base metal.
Evaluation of electrochemical properties of thermally oxidised Ti–6Al–4V for bioimplant application
Authors: Biswas A. , Manna I. , Chatterjee U. K. , Bhattacharyya U. , Majumdar Dutta J.
Published: February 2009

The present study concerns development of a thin and adherent oxide film on the surface of Ti–6Al–4V by thermal oxidation and evaluation of its electrochemical properties for the possibility of its end use as coating on bio-implant. Thermal oxidation was carried out over a range of temperatures from 400 to 600°C and time ranging from 25 to 60 h. Surface oxidation leads to formation of an adherent oxide scale consisting of different oxides of titanium, mainly Ti2O3 and TiO2 (both rutile and anatase). A significant improvement in corrosion resistance (both corrosion potential and critical potential for pit formation) of the oxide layer was achieved by thermal oxidation. The oxidised surface showed a better wettability and pitting corrosion resistance against simulated body fluid.
Transmembrane voltage regulates binding of annexin V and lactadherin to cells with exposed phosphatidylserine
Authors: Smith Christina , Gibson Donald F , Tait Jonathan F
Published: February 2009

Background

Cells expose phosphatidylserine during apoptosis. The voltage across the plasma membrane also decreases or disappears during apoptosis, but the physiological significance of this is unknown.

Results

Here we show that transmembrane potential regulates membrane binding of two unrelated proteins that recognize exposed phosphatidylserine on apoptotic cells. In Jurkat T leukemia cells and K562 promyelocytic leukemia cells undergoing apoptosis, extracellular binding of annexin V was increased by decreasing membrane potential in a dose-dependent manner. Studies with phospholipid vesicles showed that the effect was mediated via an increase in binding affinity. The effect was independent of the apoptotic stimulus. The same phenomenon occurred with lactadherin, a structurally unrelated protein that also binds to apoptotic cells via phosphatidylserine and is essential for in vivo clearance of dying cells.

Conclusion

Alterations in membrane potential regulate the binding of annexin V and lactadherin to cell membranes, and may also influence the membrane binding of other classes of phosphatidylserine-binding proteins.
ER stress affects processing of MHC class I-associated peptides
Authors: Granados Diana P , Tanguay Pierre-Luc , Hardy Marie-Pierre , Caron Étienne , de Verteuil Danielle , Meloche Sylvain , Perreault Claude
Published: February 2009

Background

Viral infection and neoplastic transformation trigger endoplasmic reticulum (ER) stress. Thus, a large proportion of the cells that must be recognized by the immune system are stressed cells. Cells respond to ER stress by launching the unfolded protein response (UPR). The UPR regulates the two key processes that control major histocompatibility complex class I (MHC I)-peptide presentation: protein synthesis and degradation. We therefore asked whether and how the UPR impinges on MHC I-peptide presentation.

Results

We evaluated the impact of the UPR on global MHC I expression and on presentation of the H2Kb-associated SIINFEKL peptide. EL4 cells stably transfected with vectors coding hen egg lysozyme (HEL)-SIINFEKL protein variants were stressed with palmitate or exposed to glucose deprivation. UPR decreased surface expression of MHC I but did not affect MHC I mRNA level nor the total amount of intracellular MHC I proteins. Impaired MHC I-peptide presentation was due mainly to reduced supply of peptides owing to an inhibition of overall protein synthesis. Consequently, generation of H2Kb-SIINFEKL complexes was curtailed during ER stress, illustrating how generation of MHC I peptide ligands is tightly coupled to ongoing protein synthesis. Notably, the UPR-induced decline of MHC I-peptide presentation was more severe when the protein source of peptides was localized in the cytosol than in the ER. This difference was not due to changes in the translation rates of the precursor proteins but to increased stability of the cytosolic protein during ER stress.

Conclusion

Our results demonstrate that ER stress impairs MHC I-peptide presentation, and that it differentially regulates expression of ER- vs. cytosol-derived peptides. Furthermore, this work illustrates how ER stress, a typical feature of infected and malignant cells, can impinge on cues for adaptive immune recognition.
Short hairpin RNA-mediated knockdown of protein expression in Entamoeba histolytica
Authors: Linford Alicia S , Moreno Heriberto , Good Katelyn R , Zhang Hanbang , Singh Upinder , Petri William A
Published: February 2009

Background

Entamoeba histolytica is an intestinal protozoan parasite of humans. The genome has been sequenced, but the study of individual gene products has been hampered by the lack of the ability to generate gene knockouts. We chose to test the use of RNA interference to knock down gene expression in Entamoeba histolytica.

Results

An episomal vector-based system, using the E. histolytica U6 promoter to drive expression of 29-basepair short hairpin RNAs, was developed to target protein-encoding genes in E. histolytica. The short hairpin RNAs successfully knocked down protein levels of all three unrelated genes tested with this system: Igl, the intermediate subunit of the galactose- and N-acetyl-D-galactosamine-inhibitable lectin; the transcription factor URE3-BP; and the membrane binding protein EhC2A. Igl levels were reduced by 72%, URE3-BP by 89%, and EhC2A by 97%.

Conclusion

Use of the U6 promoter to drive expression of 29-basepair short hairpin RNAs is effective at knocking down protein expression for unrelated genes in Entamoeba histolytica, providing a useful tool for the study of this parasite.
Role of oxidative stress and intracellular glutathione in the sensitivity to apoptosis induced by proteasome inhibitor in thyroid cancer cells
Authors: Du Zhen-Xian , Zhang Hai-Yan , Meng Xin , Guan Yifu , Wang Hua-Qin
Published: February 2009

Background

The proteasome inhibitor bortezomib has shown impressive clinical activity alone and in combination with conventional and other novel agents for the treatment of multiple myeloma (MM) and some solid cancers. Although bortezomib is known to be a selective proteasome inhibitor, the downstream mechanisms of cytotoxicity and drug resistance are poorly understood.

Methods

Proteasome activity, intracellular glutathione (GSH) and ROS levels, as well as activities of GSH synthesis enzymes were measured using spectrophotometric methods. Cell death was analyzed using flow cytometry and caspase activity assay. The expression level of GSH synthesis enzymes were measured using real-time RT-PCR.

Results

At concentrations that effectively inhibited proteasome activity, bortezomib induced apoptosis in FRO cells, but not in ARO cells. Bortezomib elevated the amount of glutathione (GSH) and the treatment with bortezomib increased the level of mRNA for GCL, a rate-limiting enzyme in glutathione synthesis. Furthermore, depletion of GSH increases apoptosis induced by bortezomib, in contrast, repletion of GSH decreases bortezomib-mediated cell death.

Conclusion

GSH protects cells from proteasome inhibition-induced oxidative stress and glutathione-dependent redox system might play an important role in the sensitivity to proteasome inhibition-induced apoptosis.
Development of the forward parachute reaction and the age of walking in near term infants: a longitudinal observational study
Authors: Romeo Domenico MM , Cioni Matteo , Scoto Mariacristina , Palermo Filippo , Pizzardi Alessandra , Sorge Anna , Romeo Mario G
Published: February 2009

Background

Near term infants are a main part of preterms. They are at higher risk for mortality and morbidity than term infants and could show a quite different development of tone and reflexes from them. The aim of the present study was to describe longitudinally, in a large sample of healthy near term infants, the development of the forward parachute reaction (FPR) and its correlation with the age of acquisition of independent walking.

Methods

The assessment of FPR (as absent, incomplete or complete) was performed at 3, 6, 9, 12 months of corrected age in 484 infants, with a gestational age between 35.0 and 36.9 weeks. The age of acquisition of independent walking was monitored until its appearance. A correlation analysis was done between the age of walking and the acquisition of a complete or incomplete FPR, using the Spearman Rank correlation. The Mann-Withney U test was used to identify significant gestational age differences for the age of FPR appearance.

Results

Most of infants had a two-step development pattern. In fact, they showed at first an incomplete and then a complete FPR, which was observed more frequently at 9 months. An incomplete FPR only, without a successive maturation to a complete FPR, was present in the 21% of the whole sample. Infants with a complete FPR walked at a median age of 13 months, whereas those with an incomplete FPR only walked at a median age of 14 months.

Conclusion

We identified two groups within our sample of near term infants. The first group showed a progressive maturation of FPR, whereas the second one was characterised by the inability to get a complete pattern, within the one year observation's period. Furthermore, we observed a trend toward a delayed acquisition of independent walking in the latter group of infants.
Differential susceptibility to obesity between male, female and ovariectomized female mice
Authors: Hong Jina , Stubbins Renee E , Smith Rebekah R , Harvey Alison E , Núñez Nomelí P
Published: February 2009

Background

The prevalence of obesity has increased dramatically. A direct comparison in the predisposition to obesity between males, premenopausal females, and postmenopausal females with various caloric intakes has not been made. To determine the effects of sex and ovarian hormones on the susceptibility to obesity, we conducted laboratory studies with mice. To eliminate confounders that can alter body weight gain, such as age and food consumption; we used mice with the same age and controlled the amount of calories they consumed.

Methods

We determined sex-specific susceptibility to obesity between male, non-ovariectomized female, and ovariectomized female mice. To compare susceptibility to gaining body weight between males and females, animals from each sex were exposed to either a 30% calorie-restricted, low-fat (5% fat), or high-fat (35% fat) diet regimen. To establish the role of ovarian hormones in weight gain, the ovaries were surgically removed from additional female mice, and then were exposed to the diets described above. Percent body fat and percent lean mass in the mice were determined by dual energy x-ray absorptiometry (DEXA).

Results

In all three diet categories, male mice had a greater propensity of gaining body weight than female mice. However, ovariectomy eliminated the protection of female mice to gaining weight; in fact, ovariectomized female mice mimicked male mice in their susceptibility to weight gain. In summary, results show that male mice are more likely to become obese than female mice and that the protection against obesity in female mice is eliminated by ovariectomy.

Conclusion

Understanding metabolic differences between males and females may allow the discovery of better preventive and treatment strategies for diseases associated with body weight such as cancer and cardiovascular disease.
ErratumTo: Genotypic detection of rifampicin and isoniazid resistant Mycobacterium tuberculosis strains by DNA sequencing: a randomized trial
Authors: Abdelaal Amina , El-Ghaffar Hassan Abd , Zaghloul Mohammad Hosam Eldeen , El mashad Noha , Badran Ehab , Fathy Amal
Published: February 2009

Correction to Genotypic detection of rifampicin and isoniazid resistant Mycobacterium tuberculosis strains by DNA sequencing: a randomized trial Amina Abdelaal, Hassan Abd El-Ghaffar, Mohammad Hosam Eldeen Zaghloul, Noha El mashad, Ehab Badran, Amal Fathy Annals of Clinical Microbiology and Antimicrobials 2009, 8:4 (30 January 2009)
Novel point mutations attenuate autotaxin activity
Authors: Koh Eunjin , Bandle Russell W , Roberts David D , Stracke Mary L , Clair Timothy
Published: February 2009

Background

The secreted enzyme autotaxin (ATX) stimulates tumor cell migration, tumorigenesis, angiogenesis, and metastasis. ATX hydrolyzes nucleotides, but its hydrolysis of lysophospholipids to produce lysophosphatidic acid (LPA) accounts for its biological activities. ATX has been identified only as a constitutively active enzyme, and regulation of its activity is largely unexplored. In spite of its presence in plasma along with abundant putative substrate LPC, the product LPA is found in plasma at unexpectedly low concentrations. It is plausible that the LPA-producing activity of ATX is regulated by its expression and by access to substrate(s). For this reason studying the interaction of enzyme with substrate is paramount to understanding the regulation of LPA production.

Results

In this study we determine ATX hydrolytic activities toward several artificial and natural substrates. Two novel point mutations near the enzyme active site (H226Q and H434Q) confer attenuated activity toward all substrates tested. The Vmax for LPC compounds depends upon chain length and saturation; but this order does not differ among wild type and mutants. However the mutant forms show disproportionately low activity toward two artificial substrates, pNpTMP and FS-3. The mutant forms did not significantly stimulate migration responses at concentrations that produced a maximum response for WT-ATX, but this defect could be rescued by inclusion of exogenous LPC.

Conclusion

H226Q-ATX and H434Q-ATX are the first point mutations of ATX/NPP2 demonstrated to differentially impair substrate hydrolysis, with hydrolysis of artificial substrates being disproportionately lower than that of LPC. This implies that H226 and H434 are important for substrate interaction. Assays that rely on hydrolyses of artificial substrates (FS-3 and pNpTMP), or that rely on hydrolysis of cell-derived substrate, might fail to detect certain mutated forms of ATX that are nonetheless capable of producing LPA in the presence of sufficient exogenous substrate. H420Q-ATX could not be differentiated from WT-ATX, indicating that histidine at position 420 is not required for any of the activities of ATX tested in this study.
Serous adenocarcinoma of the fallopian tube, associated with verrocous carcinoma of the uterine cervix: a case report of synchronic rare gynecological tumors
Authors: Cantu de Leon David , Perez Montiel Delia , Tabarez Adan , Martinez Rocio Mendez , Cetina Lucely
Published: February 2009

Background

Synchronous gynecological tumors are rare; it is even rarer to find the rarest of gynecological tumors that of the fallopian tube, together with a histological sub-type as rare as verrucous cervix.

Case presentation

We report a synchronic fallopian tube adenocarcinoma and a verrucous cervical cancer. A 85-year-old woman with postmenopausal genital hemorrhage, endometrial biopsy was reported as squamous metaplasia, an exploratory laparotomy was performed finding a tubal tumor diagnosed as adenocarcinoma, a staging procedure was performed. Final staging revealed IB1 cervical carcinoma and IA G3 fallopian tube carcinoma. Adjuvant treatment with chemotherapy was not accepted by the patient. The patient has remained in follow-up, and at 9 months, there has been no documented evidence of recurrent disease.

Conclusion

Reasons for our presentation of this work are: first, due to the rarity of these, and second, because of the usefulness of possessing a case report for establishing a norm for later behavior with respect to treatment of these patients.
HIV-1 TAR miRNA protects against apoptosis by altering cellular gene expression
Authors: Klase Zachary , Winograd Rafael , Davis Jeremiah , Carpio Lawrence , Hildreth Richard , Heydarian Mohammad , Fu Sidney , McCaffrey Timothy , Meiri Eti , Ayash-Rashkovsky Mila , Gilad Shlomit , Bentwich Zwi , Kashanchi Fatah
Published: February 2009

Background

RNA interference is a gene regulatory mechanism that employs small RNA molecules such as microRNA. Previous work has shown that HIV-1 produces TAR viral microRNA. Here we describe the effects of the HIV-1 TAR derived microRNA on cellular gene expression.

Results

Using a variation of standard techniques we have cloned and sequenced both the 5' and 3' arms of the TAR miRNA. We show that expression of the TAR microRNA protects infected cells from apoptosis and acts by down-regulating cellular genes involved in apoptosis. Specifically, the microRNA down-regulates ERCC1 and IER3, protecting the cell from apoptosis. Comparison to our cloned sequence reveals possible target sites for the TAR miRNA as well.

Conclusion

The TAR microRNA is expressed in all stages of the viral life cycle, can be detected in latently infected cells, and represents a mechanism wherein the virus extends the life of the infected cell for the purpose of increasing viral replication.
Revisiting the relationship between baseline risk and risk under treatment
Authors: Wang Hao , Boissel Jean-Pierre , Nony Patrice
Published: February 2009

Background

In medical practice, it is generally accepted that the 'effect model' describing the relationship between baseline risk and risk under treatment is linear, i.e. 'relative risk' is constant. Absolute benefit is then proportional to a patient's baseline risk and the treatment is most effective among high-risk patients. Alternatively, the 'effect model' becomes curvilinear when 'odds ratio' is considered to be constant. However these two models are based on purely empirical considerations, and there is still no theoretical approach to support either the linear or the non-linear relation.

Presentation of the hypothesis

From logistic and sigmoidal Emax (Hill) models, we derived a phenomenological model which includes the possibility of integrating both beneficial and harmful effects. Instead of a linear relation, our model suggests that the relationship is curvilinear i.e. the moderate-risk patients gain most from the treatment in opposition to those with low or high risk.

Testing the hypothesis

Two approaches can be proposed to investigate in practice such a model. The retrospective one is to perform a meta-analysis of clinical trials with subgroups of patients including a great range of baseline risks. The prospective one is to perform a large clinical trial in which patients are recruited according to several prestratified diverse and high risk groups.

Implications of the hypothesis

For the quantification of the treatment effect and considering such a model, the discrepancy between odds ratio and relative risk may be related not only to the level of risk under control conditions, but also to the characteristics of the dose-effect relation and the amount of dose administered. In the proposed approach, OR may be considered as constant in the whole range of Rc, and depending only on the intrinsic characteristics of the treatment. Therefore, OR should be preferred rather than RR to summarize information on treatment efficacy.
Isolation and characterization of a genotype 4 Hepatitis E virus strain from an infant in China
Authors: Zhang Wen , Yang Shixing , Shen Quan , Liu Junfeng , Shan Tongling , Huang Fen , Ning Huibo , Kang Yanjun , Yang Zhibiao , Cui Li , Zhu Jianguo , Hua Xiuguo
Published: February 2009

In the present study, a genotype 4 HEV strain was identified in the fecal specimen from a seven months old infant with no symptom of hepatitis in Shanghai Children's hospital. The full capsid protein gene (ORF2) sequence of this strain was determined by RT-PCR method. Sequence analysis based on the full ORF2 sequence indicated that this HEV strain shared the highest sequence identity (97.6%) with another human HEV strain isolated from a Japanese patient who was infected by genotype 4 HEV during traveling in Shanghai. Phylogenetic analysis showed that this genotype 4 HEV was phylogenetically far from the genotype 4 HEV strain that was commonly prevalent in Shanghai swine group, suggesting that this strain may not come from swine group and not involved in zoonotic transmission in this area.
Analysis of adenoviral attachment to human platelets
Authors: Shimony Nilly , Elkin Gregory , Kolodkin-Gal Dror , Krasny Lina , Urieli-Shoval Simcha , Haviv Yosef S
Published: February 2009

Background

Systemic adenoviral (Ad) vector administration is associated with thrombocytopenia. Recently, Ad interaction with mouse platelets emerged as a key player determining liver uptake and platelet clearance. However, whether Ad can activate platelets is controversial. Thus, in vitro analysis of Ad attachment to platelets is of interest.

Methods

We developed a direct flow cytometry assay to specifically detect Ad particles adherent to human platelets. The method was pre-validated in nucleated cells. Blocking assays were employed to specifically inhibit Ad attachment to platelets. Platelet activation was analyzed using annexin v flow cytometry.

Results

We found in vitro that Ad binding to human platelets is synergistically enhanced by the combination of platelet activation by thrombin and MnCl2 supplementation. Of note, Ad binding could activate human platelets. Platelets bound Ad displaying an RGD ligand in the fiber knob more efficiently than unmodified Ad. In contrast to a previous report, CAR expression was not detected on human platelets. Integrins appear to mediate Ad binding to platelets, at least partially. Finally, αIIbβ3-deficient platelets from a patient with Glanzmann thrombasthenia could bind Ad 5-fold more efficiently than normal platelets.

Conclusion

The flow cytometry methodology developed herein allows the quantitative measurement of Ad attachment to platelets and may provide a useful in vitro approach to investigate Ad interaction with platelets.
KinImmerse: Macromolecular VR for NMR ensembles
Authors: Block Jeremy N , Zielinski David J , Chen Vincent B , Davis Ian W , Vinson E Claire , Brady Rachael , Richardson Jane S , Richardson David C
Published: February 2009

Background

In molecular applications, virtual reality (VR) and immersive virtual environments have generally been used and valued for the visual and interactive experience – to enhance intuition and communicate excitement – rather than as part of the actual research process. In contrast, this work develops a software infrastructure for research use and illustrates such use on a specific case.

Methods

The Syzygy open-source toolkit for VR software was used to write the KinImmerse program, which translates the molecular capabilities of the kinemage graphics format into software for display and manipulation in the DiVE (Duke immersive Virtual Environment) or other VR system. KinImmerse is supported by the flexible display construction and editing features in the KiNG kinemage viewer and it implements new forms of user interaction in the DiVE.

Results

In addition to molecular visualizations and navigation, KinImmerse provides a set of research tools for manipulation, identification, co-centering of multiple models, free-form 3D annotation, and output of results. The molecular research test case analyzes the local neighborhood around an individual atom within an ensemble of nuclear magnetic resonance (NMR) models, enabling immersive visual comparison of the local conformation with the local NMR experimental data, including target curves for residual dipolar couplings (RDCs).

Conclusion

The promise of KinImmerse for production-level molecular research in the DiVE is shown by the locally co-centered RDC visualization developed there, which gave new insights now being pursued in wider data analysis.
Celiac disease as a potential cause of idiopathic portal hypertension: a case report
Authors: Zamani Farhad , Amiri Afsaneh , Shakeri Ramin , Zare Ali , Mohamadnejad Mehdi
Published: February 2009

Introduction

Idiopathic portal hypertension is a disorder of unknown etiology, clinically characterized by portal hypertension, splenomegaly and anemia secondary to hypersplenism.

Case presentation

A 54-year-old man was admitted to our hospital for evaluation of malaise, weight loss, abdominal swelling and lower limb edema. His paraclinical tests revealed pancytopenia, large ascites, splenomegaly and esophageal varices consistent with portal hypertension. Duodenal biopsy and serologic findings were compatible with celiac disease. His symptoms improved on a gluten-free diet, but his clinical course was further complicated with ulcerative jejunoileitis, and intestinal T-cell lymphoma.

Conclusion

It seems that celiac disease, by an increased immune reaction in the splenoportal axis, can result in the development of idiopathic portal hypertension in susceptible affected patients.
Detection of lymphangiogenesis in non-small cell lung cancer and its prognostic value
Authors: Sun Jian-guo , Wang Yan , Chen Zheng-tang , Zhuo Wen-lei , Zhu Bo , Liao Rong-xia , Zhang Shao-xiang
Published: February 2009

Background

Our aim was to detect lymphatic endothelial marker podoplanin, lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) and vascular endothelial growth factor receptor-3 (VEGFR)-3 and study the prognostic relevance of lymphangiogenesis in non-small cell lung cancer (NSCLC).

Materials

82 paraffin-embedded tissues and 40 fresh frozen tissues from patients with NSCLC were studied. Tumor samples were immunostained for the lymphatic endothelial markers. Lymphangiogenesis was assessed by immunohistochemical double stains for Podoplanin and Ki-67. The prognostic relevance of lymphangiogenesis-related clinicopathological parameters in NSCLC was evaluated.

Results

We found that the number of podoplanin positive vessels was correlated positively with the number of LYVE-1 positive vessels. Most of VEGFR-3 positive, few of LYVE-1 positive and none of podoplanin positive vessels were blood vessels. Peritumoral lymphatic vessel density (ptLVD), pathologic stage, lymph node status, lymphatic vessel invasion (LVI), vascular endothelial growth factor-C (VEGF-C) expression and Ki-67 index of the endothelium cells of the micro lymphatic vessels (Ki67%) were associated significantly with a higher risk of tumor progress. ptLVD, pathologic stage, lymph-node metastasis and Ki67% were independent prognostic parameters for overall survival.

Conclusion

Podoplanin positive ptLVD might play important roles in the lymphangiogenesis and progression of NSCLC. Patients with high podoplanin+ ptLVD have a poor prognosis.
The Harvard Economic Service and the Problems of Forecasting
Authors: Friedman Walter A.
Published: February 2009

The Harvard Economic Service pioneered the business of economic forecasting by publishing a weekly newsletter on economic conditions, starting in 1922. The Harvard forecasting model, developed by the statistician and economist Warren Persons, gained international renown for its three-curve A-B-C chart, which rendered business fluctuations as the ebb and flow of speculation (A), business (B), and banking (C). The service was directed by C. J. Bullock, who promoted Harvard's forecasting service around the world by forming collaborative agreements with John Maynard Keynes, Lucien March, Corrado Gini, and other prominent economists of the time. The Harvard Economic Service, however, attracted criticism for its purely empirical approach, its failure to make consistently accurate predictions, and its pursuit of commercial objectives in a university setting. The Harvard group's efforts to build a forecasting service are an early chapter in the evolution of the social sciences, the growth of a class of financial analysts, and the commercialization of academic knowledge.
American Economic Reform in the Progressive Era: Its Foundational Beliefs and Their Relation to Eugenics
Authors: Leonard Thomas C.
Published: February 2009

This essay explores the progressive beliefs other than human hierarchy that inclined Progressive Era economic reform toward eugenics. It argues the following: that the progressives believed in a powerful, centralized state, conceiving of government as the best means for promoting the social good and rejecting the individualism of (classical) liberalism; that the progressives venerated social efficiency; that the progressives believed in the epistemic and moral authority of science, a belief that comprised their view that biology could explain and control human inheritance and that the still nascent sciences of society could explain and control the causes of economic ills; that the progressives believed that intellectuals should guide social and economic progress, a belief erected upon two subsidiary faiths, a faith in the disinterestedness and incorruptibility of the experts who would run the technocracy they envisioned, and a faith that expertise could not only serve the social good, but also identify it; and that, while antimonopoly, the progressives believed that increasing industrial consolidation was inevitable, and desirable, consistent with their faith in planning, organization, and command.
Measuring Inequality: Pareto's Ambiguous Contribution
Authors: Maccabelli Terenzio
Published: February 2009

Pareto was probably the first economist to suggest a way of measuring the inequality of incomes. But the interpretation of his index α came to be an object of contrasting judgments. This paper offers a reconstruction of the debate that involved Pareto's index, aimed at clarifying his thought on the question. The thesis is that Pareto has not made any contribution to the criteria for measuring inequality and, as such, has to be evaluated using other parameters.
Introduction: The Still Vacillating Equilibrium of the World
Authors: Connery Christopher , Spillers Hortense J.
Published: February 2009

We would like to thank Paul Bové and the editors of boundary 2 for their encouragement and support. Special thanks go to John Beverley, sixties man, not only for his work as author, editor, translator, and facilitator for this issue, but for an exemplary and inspiring career of committed, critical, and self-critical scholarship.
Black Power, Decolonization, and Caribbean Politics: Walter Rodney and the Politics of The Groundings with My Brothers
Authors: Bogues Anthony
Published: February 2009

The October 16, 1968, riot, popularly known as the “Rodney Affair,” was a watershed moment in Caribbean political history. The riot was triggered by the Jamaican government's banning of the revolutionary scholar Walter Rodney. This essay discusses the 1968 riot and the political practice and thought of Walter Rodney as one moment in the historic moment of Black Power as an international political banner under which significant sections of the Black World were mobilized.
Reasoning about physician-assisted suicide: analysis of comments by physicians and the Swedish general public
Authors: Helgesson Gert , Lindblad Anna , Thulesius Hans , Lynöe Niels
Published: February 2009

Two questionnaires directed to Swedish physicians and a sample of the Swedish population investigated attitudes towards physician-assisted suicide (PAS). The aim of the present work was to analyse qualitative data from these questionnaires in order to explore how respondents reason about PAS. Data were analysed in two steps. First, we categorized different kinds of responses and identified pro and con arguments. Second, we identified general conclusions from the responses. The data reflect the differences in attitudes towards PAS among the public and physicians, with the former mainly in favour of PAS and the latter mainly against. There was, however, considerable agreement about what requirements must be met before PAS could be considered ethical. Many arguments against PAS concerned the professional role of physicians, which indicates that it may not be assisted suicide as such that many PAS opponents disagree with, but rather that it is handled by physicians in the regular health-care system.
The Shock of the Human: how the media can change the way we think about ethical dilemmas in medicine
Authors: Barclay Sarah
Published: February 2009

The relationship between the media and the medical profession is often one of mutual mistrust. However, the media, and especially television, is a powerful tool for telling individual stories and for providing a medium for medico-ethical dilemmas to be portrayed to a wide audience. The extent to which the use of individual narratives can or should influence public opinion about complex medical issues is examined in this paper from the perspective of a former television journalist with a postgraduate degree in medical law and ethics.
When is deception in research ethical?
Authors: Athanassoulis Nafsika , Wilson James
Published: February 2009

This article examines when deceptive withholding of information is ethically acceptable in research. The first half analyses the concept of deception. We argue that there are two types of accounts of deception: normative and non-normative, and argue that non-normative accounts are preferable. The second half of the article argues that the relevant ethical question which ethics committees should focus on is not whether the person from whom the information is withheld will be deceived, but rather on the reasonableness of withholding the information from the person who is deceived. We further argue that the reasonableness of withholding information is dependent on the context. The last section examines how the context of research should shape our judgements about the circumstances in which withholding information from research participants is ethically acceptable. We argue that some important features of research make it more difficult to justify withholding information in the context of research than elsewhere.
Hope and terminal illness: false hope versus absolute hope
Authors: Garrard Eve , Wrigley Anthony
Published: February 2009

Sustaining hope in patients is an important element of health care, allowing improvement in patient welfare and quality of life. However in the palliative care context, with patients who are terminally ill, it might seem that in order to maintain hope the palliative care practitioner would sometimes have to deceive the patient about the full nature or prospects of their condition by providing a ‘false hope’. This possibility creates an ethical tension in palliative practice, where the beneficent desire to improve patient welfare through sustaining hope appears to be in conflict with an autonomy-based requirement not to deceive patients about their condition. In order to resolve this ethical tension, we provide an analysis of the concept of hope and argue that there is at least one conception – the ‘absolute’ conception of hope – which when properly understood allows practitioners to foster hope in terminally-ill patients while avoiding any need to deceive them about their condition. Practitioners therefore do not need to shy away from using the language of hope in the palliative setting, as on this understanding of hope it can be used in a way that both promotes patient welfare and respects patient autonomy.
Screening offenders for risk of drop‐out and expulsion from correctional programmes
Authors: Nunes Kevin L. , Cortoni Franca , Serin Ralph C.
Published: February 2009

Purpose. The goal of the present research was to develop a screening measure to assist in identifying offenders at risk for drop‐out or expulsion from correctional programmes.

Methods. Non‐Aboriginal male offenders (N = 5,247) were randomly divided into a development sample (N = 2,617) and a validation sample (N = 2,630). In the development sample, individual predictors were identified through univariate and multivariate analyses, weighted based on their relationship with drop‐out/expulsion, and combined into a composite measure we called the drop‐out risk screen (DRS).

Results. The DRS consists of five items, including static and dynamic risk factors for recidivism as well as motivation for intervention. It significantly predicted drop‐out/expulsion in the development sample (area under the receiver operating characteristic curve [AUC]= .72) and performed similarly in the validation sample (AUC = .70).

Conclusions. The results indicate that the DRS is a valid screening instrument for risk of drop‐out/expulsion. Prior to commencement of a treatment programme, offenders with high scores on the DRS could be more thoroughly assessed and, if necessary, targeted with pre‐treatment efforts to increase their motivation and general readiness for treatment.