bluuebunny/crossref_metadata_2025_split huggingface dataset:
Susceptibility of neonatal T cells and adult thymocytes to peripheral tolerance to allogeneic stimuli
Authors: Do Canto Fábio B. , Junior Celso Lima , Teixeira Ivan A. , Bellio Maria , Nóbrega Alberto , Fucs Rita 
Published: May 2008

SummaryWe studied the tolerization of neonatal thymocytes (NT), neonatal splenocytes (NS) and adult thymocytes (AT), transferred to syngeneic nude (nu/nu) hosts previously injected with semi‐allogeneic splenocytes, without any supportive immunosuppressive treatment. This protocol allows the study of peripheral tolerance in the absence of the thymus. BALB/c neonatal T cells and ATs were able to expand in syngeneic BALB/c nu/nu mice and functionally reconstituted an allogeneic response, rejecting (BALB/c × B6.Ba) F1 splenocytes transferred 3–4 weeks after injection of BALB/c cells. However, if (BALB/c × B6.Ba) F1 cells were injected into BALB/c nude hosts 30 days before transfer of NT, NS or AT cells, the F1 population was preserved and specific tolerance to B6 allografts was established. Furthermore, transfer to lymphopenic F1 nu/nu showed that tolerance could be established only for neonatal populations, showing that unique properties of neonatal T cells allow their tolerization in both lymphopenic and non‐lymphopenic conditions, in the absence of suppressive immunotherapy. These results bring empirical support to the possibility of T‐cell engraftment in immunodeficient patients showing partial identity with donor major histocompatibility complex (MHC) genes; the manipulation of immunological maturity of donor T cells may be the key for successful reconstitution of immunocompetence without induction of graft‐versus‐host disease.
Targeted deletion of SAP1 abolishes the expression of infectivity factors necessary for successful malaria parasite liver infection
Authors: Aly Ahmed S. I. , Mikolajczak Sebastian A. , Rivera Hilda Silva , Camargo Nelly , Jacobs‐Lorena Vanessa , Labaied Mehdi , Coppens Isabelle , Kappe Stefan H. I. 
Published: May 2008

SummaryMalaria parasite sporozoites prepare for transmission to a mammalian host by upregulation of UIS (Upregulated in Infectious Sporozoites) genes. A number of UIS gene products are essential for the establishment of the intrahepatocytic niche. However, the factors that regulate the expression of genes involved in gain of infectivity for the liver are unknown. Herein, we show that a conserved Plasmodium sporozoite low‐complexity asparagine‐rich protein, SAP1 (Sporozoite Asparagine‐rich Protein 1), has an essential role in malaria parasite liver infection. Targeted deletion of SAP1 in the rodent malaria parasite Plasmodium yoelii generated mutant parasites that traverse and invade hepatocytes normally but cannot initiate liver‐stage development in vitro and in vivo. Moreover, immunizations with Pysap1(−) sporozoites confer long‐lasting sterile protection against wild‐type sporozoite infection. Strikingly, lack of SAP1 abolished expression of essential UIS genes including UIS3, UIS4 and P52 but not the constitutively expressed genes encoding, among others, sporozoite proteins CSP and TRAP. SAP1 localization to the cell interior but not the nucleus of sporozoites suggests its involvement in a post‐transcriptional mechanism of gene expression control. These findings demonstrate that SAP1 is essential for liver infection possibly by functioning as a selective regulator controlling the expression of infectivity‐associated parasite effector genes.
There is no heterotic effect upon developmental stability in the ventral side of the skull within the house mouse hybrid zone
Authors: MIKULA O. , MACHOLÁN M. 
Published: May 2008

AbstractFluctuating asymmetry (FA) of a body is expected to be related to an organism’s developmental instability. We studied patterns of FA in the ventral side of the skull along a transect across the central‐European portion of the hybrid zone between two house mouse subspecies,Mus musculus musculusandMus musculus domesticus. We found that FA was not significantly different between introgression classes relative to differences between localities within those classes and that the within‐class differences were much larger than differences between individual‐signed asymmetries within localities. However, if year was added to the same analysis as another factor, FA was not significantly different among localities within the same introgression class. When individual asymmetries were plotted against individual hybrid indices, hybrids appeared more asymmetric than individuals from outside of the zone. Thus contrary to previous studies, we did not find lower FA indicating heterotic effect in hybrids for the traits studied. It is suggested that the impact of hybridization on FA in the ventral side of the mouse skull is negligible or overwhelmed by other factors.
Variation in genetic architecture of olfactory behaviour among wild‐derived populations of Drosophila melanogaster
Authors: LAVAGNINO N. J. , ANHOLT R. R. H. , FANARA J. J. 
Published: May 2008

AbstractOdour‐guided behaviour is a quantitative trait determined by many genes that are sensitive to gene–environment interactions. Different natural populations are likely to experience different selection pressures on the genetic underpinnings of chemosensory behaviour. However, few studies have reported comparisons of the quantitative genetic basis of olfactory behaviour in geographically distinct populations. We generated isofemale lines of Drosophila melanogaster from six populations in Argentina and measured larval and adult responses to benzaldehyde. There was significant variation within populations for both larval and adult olfactory behaviour and a significant genotype × sex interaction (GSI) for adult olfactory behaviour. However, there is substantial variation in the contribution of GSI to the total phenotypic variance among populations. Estimates of evolvability are orders of magnitude higher for larvae than for adults. Our results suggest that the potential for evolutionary adaptation to the chemosensory environment is greater at the larval feeding stage than at the adult reproductive stage.
Normal Development of the Muscular Region of the Interventricular Septum – I. The Significance of the Ventricular Trabeculations
Authors: Contreras‐Ramos A. , Sánchez‐Gómez C. , García‐Romero H. L. , Cimarosti L. O. 
Published: May 2008

SummaryThe structures that participate in normal ventricular septation, and to what extent they do so, are questions not yet clarified. Even less is known about how much each of the embryonic structures contributes to the topography of the mature interventricular septum (IVS). The aim of the present paper is to investigate the significance of ventricular trabeculations in the normal development of the muscular region (the middle and apical thirds) of the IVS and to determine the direction in which it grows during cardiac septation. Anatomical studies and in vivo labelling were carried out in chicken embryo hearts at stage 18HH, tracing the labels up to stage 36HH. We analysed the results by measuring the distance between the labelled structures at the beginning and end of the experiments. We demonstrate that the muscular region of the septum originates by the fusion of the ventricular trabeculations with evidence that during cardiac development, the IVS as well as the ventricular cavities grow in opposite direction to the atria.
Modelling the Spread in Space and Time of An Airborne Plant Disease
Authors: Soubeyrand Samuel , Held Leonhard , Höhle Michael , Sache Ivan 
Published: May 2008

SummaryA spatiotemporal model is developed to analyse epidemics of airborne plant diseases which are spread by spores. The observations consist of measurements of the severity of disease at different times, different locations in the horizontal plane and different heights in the vegetal cover. The model describes the joint distribution of the occurrence and the severity of the disease. The three-dimensional dispersal of spores is modelled by combining a horizontal and a vertical dispersal function. Maximum likelihood combined with a parametric bootstrap is suggested to estimate the model parameters and the uncertainty that is attached to them. The spatiotemporal model is used to analyse a yellow rust epidemic in a wheatfield. In the analysis we pay particular attention to the selection and the estimation of the dispersal functions.
A Multi-Resolution Census Algorithm for Calculating Vortex Statistics in Turbulent Flows
Authors: Whitcher Brandon , Lee Thomas C. M. , Weiss Jeffrey B. , Hoar Timothy J. , Nychka Douglas W. 
Published: May 2008

Summary
The fundamental equations that model turbulent flow do not provide much insight into the size and shape of observed turbulent structures. We investigate the efficient and accurate representation of structures in two-dimensional turbulence by applying statistical models directly to the simulated vorticity field. Rather than extract the coherent portion of the image from the background variation, as in the classical signal-plus-noise model, we present a model for individual vortices using the non-decimated discrete wavelet transform. A template image, which is supplied by the user, provides the features to be extracted from the vorticity field. By transforming the vortex template into the wavelet domain, specific characteristics that are present in the template, such as size and symmetry, are broken down into components that are associated with spatial frequencies. Multivariate multiple linear regression is used to fit the vortex template to the vorticity field in the wavelet domain. Since all levels of the template decomposition may be used to model each level in the field decomposition, the resulting model need not be identical to the template. Application to a vortex census algorithm that records quantities of interest (such as size, peak amplitude and circulation) as the vorticity field evolves is given. The multiresolution census algorithm extracts coherent structures of all shapes and sizes in simulated vorticity fields and can reproduce known physical scaling laws when processing a set of vorticity fields that evolve over time.
Conditional Asset Pricing and Stock Market Anomalies in Europe
Authors: Bauer Rob , Cosemans Mathijs , Schotman Peter C. 
Published: May 2008

Abstract This study provides European evidence on the ability of static and dynamic specifications of the Fama‐French (1993) three‐factor model to price 25 size‐B/M portfolios. In contrast to US evidence, we detect a small‐growth premium and find that the size effect is still present in Europe. Furthermore, we document strong time variation in factor risk loadings. Incorporating these risk fluctuations in conditional specifications of the three‐factor model clearly improves its ability to explain time variation in expected returns. However, the model still fails to completely capture cross‐sectional variation in returns as it is unable to explain the momentum effect.
Forced Displacement in Darfur, Sudan: Dilemmas of Classifying the Crimes
Authors: Mulaj Klejda 
Published: May 2008

ABSTRACTThe ongoing forced displacement in Darfur has occasioned renewed interest in the phenomena of genocide and ethnic cleansing. Whereas the international response to the conflict has been considered promptly and elaborately by various analysts, few have paid sufficient attention, in the first instance, to the controversy surrounding the debate about the definition of the situation and the classification of crimes involved. Following an overview of the current conflict, the unfolding analysis seeks to show that the terminological debate reveals discrepancies in legal definitions and interpretations that may suggest that existing law may be inadequate to fully capture the nature of the crimes committed in Darfur. Confusion with the terminology has contributed to making the conflict more intractable. In addition, disagreement on a common definition of the situation has tended to justify inaction or limited involvement on the part of the international community. This article suggests that it is therefore necessary to resolve the terminological debate in order to ensure that no energy is wasted in arguing about the indeterminacy of the terms in the future and effective responses to mass violations of human rights are crafted in a timely fashion.
Gram‐negative outer membrane vesicles: beyond the cell surface
Authors: MASHBURN‐WARREN L , MCLEAN R. J. C. , WHITELEY M 
Published: May 2008

ABSTRACTConsiderable interest has recently mounted regarding the biological roles of Gram‐negative outer membrane vesicles (MVs). The first discovery of MVs was made over four decades ago, and it is now clear that most Gram‐negative bacteria produce MVs, with Pseudomonas aeruginosa and Escherichia coli as the most extensively studied. Much of our knowledge of the biological roles of MVs and mechanism of MV formation is due to T.J. Beveridge and colleagues. Beveridge pioneered the field of MV research not only by enhancing our understanding of MV function, but also through the application of a wide variety of physical, chemical, and genetic techniques to complement his elegant electron microscopy investigations. Here we review the contributions of Beveridge's group to our understanding of MV biology.
Prevalence of pressure ulcers on hospital admission among nursing home residents transferred to the hospital
Authors: Keelaghan Eithne , Margolis David , Zhan Min , Baumgarten Mona 
Published: May 2008

ABSTRACTThe purpose of this study was to compare the prevalence of pressure ulcers among newly hospitalized nursing home residents and among newly hospitalized patients from nonnursing home settings. Study participants were at least 65 years old and admitted through the emergency department to one of two study hospitals. Research nurses ascertained the presence of pressure ulcers (stage 1–4) by visual skin assessment on the third day following admission to the hospital unit. Other data were collected by clinical examination, interview, and medical record review. The prevalence of preexisting pressure ulcers at the time of admission was 26.2% among those admitted from a nursing home and 4.8% among those admitted from another living situation (odds ratio 5.5, 95% confidence interval 4.3–7.1). After adjustment for confounders, the association between admission from a nursing home and pressure ulcer prevalence on admission was reduced (odds ratio 1.51, 95% confidence interval 1.03–2.23). These results indicate that admission from a nursing home is a potent marker for pressure ulcer risk and that the excess risk is largely mediated by the higher prevalence of pressure ulcer risk factors among patients admitted from a nursing home. The results highlight the importance of continuity of care across transitions between care settings.
Differentiation of the pericyte in wound healing: The precursor, the process, and the role of the vascular endothelial cell
Authors: Xueyong Li , Shaozong Chen , Wangzhou Li , Yuejun Li , Xiaoxing Lv , Jing Li , Yanli Wei , Jinqing Li 
Published: May 2008

ABSTRACTPericytes play a crucial role in the homeostasis and maturation of newly formed vessels, but their precursor and the process of their differentiation remain unclear. In this study, we show that in vivo, pericytes in human granulation tissue taken from burn patients expressed CD13 and collagen I, which are cell markers of peripheral blood fibrocytes (PBFCs). Mouse PBFCs, ex vivo labeled by PKH‐26 and administered intravenously back to mice, formed lumens in the granulation tissue and expressed pericyte marker NG2. Furthermore, in cell culture, human PBFCs in co‐culture with human umbilical vascular endothelial cells or human dermal microvascular endothelial cells (HDMECs) expressed pericyte markers desmin and myosin heavy chain of smooth muscle cell, and some migrated to the membrane of human umbilical vascular endothelial cells or HDMECs to form PBFC/vascular endothelial cell clusters, or formed round PBFC only clusters with their nuclei aligned along a circle. The formation of PBFC/vascular endothelial cell clusters and round PBFC clusters were inhibited by an antibody against monocyte chemotactic protein‐1. PBFCs cultured with homogenate of granulation tissue also expressed desmin and myosin heavy chain of smooth muscle cell. Our findings support that the PBFC is a precursor of pericytes, the differentiation of PBFCs is induced by vascular endothelial cells in a paracrine fashion.
Connective tissue growth factor stimulates renal cortical myofibroblast‐like cell proliferation and matrix protein production
Authors: Gao Xuxia , Li Jingzi , Huang Haichang , Li Xiaomei 
Published: May 2008

ABSTRACTMyofibroblasts primarily contribute to the pathogenesis of renal interstitial fibrosis by unregulated cell proliferation and synthesis of excessive amounts of extracellular matrix (ECM) proteins. We used cultured myofibroblast‐like cells obtained by outgrowth from explants of rat kidney cortex to study the effects and relevant signaling pathway of connective tissue growth factor (CTGF) on cell proliferation and ECM production. Exogenous CTGF stimulated proliferation of myofibroblast‐like cells in a dose‐ and time‐dependent manner. CTGF also increased the secretion of fibronectin and collagen I protein in the supernatant medium. Nevertheless, CTGF did not affect matrix‐degrading metalloproteinases‐2 and ‐9 activities in supernatant medium measured by gelatin zymography. CTGF induced activation of extracellular signal‐regulated protein kinase (ERK)1/2 mitogen‐activated protein kinase pathway as early as 5 minutes. Inhibition of ERK1/2 activation with PD98059 completely blocked CTGF‐induced cell proliferation as well as secretion of fibronectin and collagen I protein. The above results indicate that CTGF triggers cell proliferation and production of ECM proteins in cultured myofibroblast‐like cells through the ERK1/2 mitogen‐activated protein kinase pathway.
Mechanisms of wound healing responses in lupus‐prone New Zealand White mouse strain
Authors: Campos Paula P. , Bakhle Yeshwant S. , Andrade Silvia P. 
Published: May 2008

ABSTRACTHost responses to synthetic implants are analogous to healing, the process of repair that follows injury. Normally, the processes of wound healing follow well‐established patterns but conditions such as autoimmune diseases profoundly affect tissue repair. We have analyzed sponge‐induced wound healing responses in lupus‐prone New Zealand White and control (Balb/c) mouse strains by measuring inflammation, extracellular matrix deposition, angiogenesis, and cytokine production in polyether–polyurethane sponge implanted subcutaneously in male mice of these two strains. Although there was no difference in the gross appearance of the implants, further analysis of the wound healing responses, induced from 7 to 21 days post implantation, disclosed important differences between the New Zealand White and Balb/c strains. The intensity of inflammation (circulating tumor necrosis factor‐α and inflammatory leukocytes levels) was lower but implant fibrosis (collagen and transforming growth factor‐β1) was higher in New Zealand White, compared with Balb/c mice. Angiogenesis (hemoglobin, vascular endothelial growth factor, and vascularity) in New Zealand White implants peaked earlier than in Balb/c mice. In conclusion, we have shown that wound healing responses are clearly different in this strain of lupus‐prone mice and suggest that this pattern of repair was critically influenced by impaired inflammation and accelerated angiogenesis in the New Zealand White strain.
Effect of chitosan acetate bandage on wound healing in infected and noninfected wounds in mice
Authors: Burkatovskaya Marina , Castano Ana P. , Demidova‐Rice Tatiana N. , Tegos George P. , Hamblin Michael R. 
Published: May 2008

ABSTRACTHemCon® bandage is an engineered chitosan acetate preparation designed as a hemostatic dressing, and is under investigation as a topical antimicrobial dressing. We studied its effects on healing of excisional wounds that were or were not infected with Staphylococcus aureus, in normal mice or mice previously pretreated with cyclophosphamide (CY). CY significantly suppressed wound healing in both the early and later stages, while S. aureus alone significantly stimulated wound healing in the early stages by preventing the initial wound expansion. CY plus S. aureus showed an advantage in early stages by preventing expansion, but a significant slowing of wound healing in later stages. In order to study the conflicting clamping and stimulating effects of chitosan acetate bandage on normal wounds, we removed the bandage from wounds at times after application ranging from 1 hour to 9 days. Three days application gave the earliest wound closure, and all application times gave a faster healing slope after removal compared with control wounds. Chitosan acetate bandage reduced the number of inflammatory cells in the wound at days 2 and 4, and had an overall beneficial effect on wound healing especially during the early period where its antimicrobial effect is most important.
Early Recurrences After Atrial Fibrillation Ablation: Prognostic Value and Effect of Early Reablation
Authors: LELLOUCHE NICOLAS , JAÏS PIERRE , NAULT ISABELLE , WRIGHT MATTHEW , BEVILACQUA MICHELA , KNECHT SÉBASTIEN , MATSUO SEIICHIRO , LIM KANG‐TENG , SACHER FREDERIC , DEPLAGNE ANTOINE , BORDACHAR PIERRE , HOCINI MÉLÈZE , HAÏSSAGUERRE MICHEL 
Published: May 2008

Introduction: Early arrhythmia recurrences are common within the first month after atrial fibrillation (AF) ablation. The long‐term consequences of these early recurrences (ER) are controversial. We investigated whether ER were predictive of late recurrences and the impact of early reablation on clinical outcome.
Methods: Three hundred two consecutive patients with paroxysmal or persistent AF were studied. Arrhythmia recurrence was defined as documented episode of AF or atrial tachycardia. Of 151 patients with ER, a subset of 61 patients had reablation within the first month following the index ablation (early reablation). In the remaining 90 patients, a repeat procedure was only performed for later arrhythmia recurrences occurring beyond 1 month. Patients were followed with clinical interview and ambulatory 24 hours monitoring.
Results: Patients with and without early reablation had similar baseline characteristics including echocardiographic parameters and type of AF. During a mean follow‐up of 11 ± 11 months, 82 patients (91%) without early reablation experienced late clinical recurrences. In contrast, patients with early reablation had lower rate of clinical recurrences (51% vs 91%, P < 0.0001) and fewer additional procedures (36% vs 91%, P < 0.0001). However, the total number of procedures over the entire follow‐up was greater in those patients with early reablation (2.5 ± 0.7 vs 2.2 ± 0.6, P = 0.02).
Conclusion: An overwhelming majority of patients with recurrences within the first month after ablation have late recurrences. An early reablation reduces the incidence of further recurrences. However, the overall number of procedures is higher in the medium‐term follow‐up. The optimal timing for the second procedure remains to be defined.