bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of non‐HLA genetic polymorphisms in graft‐versus‐host disease after haematopoietic stem cell transplantation
Authors: Bertinetto F. E. , Dall’Omo A. M. , Mazzola G. A. , Rendine S. , Berrino M. , Bertola L. , Magistroni P. , Caropreso P. , Falda M. , Locatelli F. , Busca A. , Amoroso A. 
Published: September 2006

SummaryGraft‐versus‐host disease (GvHD) is the main complication after haematopoietic stem cells transplantation (HSCT) and acute forms (aGvHD) occur in 20–40% of cases even after donor (D) and recipient (R) HLA matching, apparently because of D/R minor histocompatibility antigen (mHA) mismatches and cytokine polymorphisms. The genotype of cytokines and mHA of 77 haematological R following HSCT from HLA identical siblings were determined to detect genetic polymorphisms correlated with GvHD. We analysed TNFA (−863 C/A, −857 C/T and G/A at positions −574, −376, −308, −244, −238), IL‐10 (−1082 G/A, −819 C/A, −592 C/T), IL‐1B (T/C +3953), IL‐1RA (VNTR), HA‐1 (H/R allele) and CD‐31 (C/G at codon 125, A/G at codon 563). Allele frequencies were in Hardy–Weinberg equilibrium and similar to those of 77 healthy controls. We observed positive correlations between a lower risk of clinically significant aGvHD and both the presence of −1082G −819C −592C IL‐10 haplotype when both R and D are considered together and the absence of R IL‐1RA allele 2. Furthermore, we observed an association between the absence of TNF‐A −238 A allele and the risk of extensive chronic GvHD. mHA and cytokines genotyping would thus seem a valid source of information for the prior identification of recipients with a higher risk of aGvHD.
A NUMERICAL APPROACH WITH VARIABLE TEMPERATURE BOUNDARY CONDITIONS TO DETERMINE THE EFFECTIVE HEAT TRANSFER COEFFICIENT VALUES DURING BAKING OF COOKIES
Authors: DEMIRKOL EREN , ERDOGDU FERRUH , PALAZOGLU T. KORAY 
Published: September 2006

ABSTRACT The increasing trade of ready‐to‐eat foods such as cookies highlights an interest in quality defects during baking. Heat (h and thermal diffusivity) and mass (mass transfer and diffusion coefficients) transfer parameters are significant parameters affecting the quality changes. Therefore, it is important to determine these parameters for modeling and process optimization studies. Among these, the h is important, revealing the relationship between the heating medium and product surface. As baking involves a simultaneous heat and mass transfer involving moisture diffusion and heat conduction inside and convective heat and mass transfer outside, a lumped system method may not be an accurate choice to determine the h value. Changes in the product volume and contact heating from bottom of the product also bring extra challenges to the determination of h. Therefore, the objective of this study was to use realistic approaches including simultaneous heat and mass transfer to determine the changes in h. The heffvalues for the bottom and top surface of the cookies were then determined, applying a numerical procedure where the surface temperature changes were the boundary conditions with evaporation on the surface. The hband ht values increased with baking temperature and varied with baking time. The results of this study showed that evaporative mass flux for the top surface, heat flux for the bottom surface and the product's volume changes were significant in the variation of h values.
ASSESSMENT OF AN EXPONENTIAL MODEL FOR ULTRAFILTRATION OF APPLE JUICE
Authors: ÇETİNKAYA ÖZGE , GÖKMEN VURAL 
Published: September 2006

ABSTRACTThe clarification of apple juice by ultrafiltration has been commercially used for many years. A common phenomenon in membrane processes is the decline of permeate flux (J) with time (t), called “membrane fouling.” The phenomenon of membrane fouling is very complex and difficult to describe theoretically, and model studies are limited. A number of semiempirical and empirical models have been proposed to explain flux behavior during membrane filtration processes. Using these models, typicaltversusJcurve observed in membrane filtration applications was examined in two or three periods. However, the boundaries between each period could not be accurately determined and were specific to the system under investigation. Thus, these semiempirical and empirical models are valid only for the system investigated. In this article, the applicability of an exponential model to ultrafiltration of apple juice was studied. The results showed that the exponential model can be successfully applied to analyze the raw filtrate volumeVversustdata of ultrafiltration of apple juice,and initial fluxJ0, membrane resistanceRmand exponential fouling coefficientkvalues can easily be determined from the raw data.
Effects of
ompA
Deletion on Expression of Type 1 Fimbriae in
Escherichia coli
K1 Strain RS218 and on the Association of
E. coli
with Human Brain Microvascular Endothelial Cells
Authors: Teng Ching-Hao , Xie Yi , Shin Sooan , Di Cello Francescopaolo , Paul-Satyaseela Maneesh , Cai Mian , Kim Kwang Sik 
Published: September 2006

ABSTRACT

We have previously shown that outer membrane protein A (OmpA) and type 1 fimbriae are the bacterial determinants involved in
Escherichia coli
K1 binding to human brain microvascular endothelial cells (HBMEC), which constitute the blood-brain barrier. In investigating the role of OmpA in
E. coli
K1 binding to HBMEC, we showed for the first time that
ompA
deletion decreased the expression of type 1 fimbriae in
E. coli
K1. Decreased expression of type 1 fimbriae in the
ompA
deletion mutant was largely the result of driving the
fim
promoter toward the type 1 fimbrial phase-OFF orientation. mRNA levels of
fimB
and
fimE
were found to be decreased with the OmpA mutant compared to the parent strain. Of interest, the
ompA
deletion further decreased the abilities of
E. coli
K1 to bind to and invade HBMEC under the conditions of fixing type 1 fimbria expression in the phase-ON or phase-OFF status. These findings suggest that the decreased ability of the OmpA mutant to interact with HBMEC is not entirely due to its decreased type 1 fimbrial expression and that OmpA and type 1 fimbriae facilitate the interaction of
E. coli
K1 with HBMEC at least in an additive manner.
Optimization of the Delivery of Heterologous Proteins by theSalmonella entericaSerovar Typhimurium Type III Secretion System for Vaccine Development
Authors: Chen Li-Mei , Briones Gabriel , Donis Ruben O. , Galán Jorge E. 
Published: September 2006

ABSTRACTType III protein secretion systems, which are organelles with the capacity to deliver bacterial proteins into host cells, have been adapted to deliver heterologous antigens for vaccine development. A limitation of these antigen delivery systems is that some proteins are not amenable to secretion through this pathway. We show here that proteins from the simian and human immunodeficiency viruses that are not permissive for secretion through aSalmonella entericaserovar Typhimurium type III secretion system can be modified to travel this secretion pathway by introduction of discrete mutations. Proteins optimized for secretion were presented more efficiently via the major histocompatibility complex class I pathway and were able to induce a better immune response.
Overexpression, Purification, Characterization, and Pathogenicity of
Vibrio harveyi
Hemolysin VHH
Authors: Zhong Yingbin , Zhang Xiao-Hua , Chen Jixiang , Chi Zhenghao , Sun Boguang , Li Yun , Austin Brian 
Published: September 2006

ABSTRACT

Vibrio harveyi
VHH hemolysin is a putative pathogenicity factor in fish. In this study, the hemolysin gene
vhhA
was overexpressed in
Escherichia coli
, and the purified VHH was characterized with regard to pH and temperature profiles, phospholipase activity, cytotoxicity, pathogenicity to flounder, and the signal peptide.
Actin Cytoskeleton-Dependent and -Independent Host Cell Invasion byTrypanosoma cruziIs Mediated by Distinct Parasite Surface Molecules
Authors: Ferreira Daniele , Cortez Mauro , Atayde Vanessa D. , Yoshida Nobuko 
Published: September 2006

ABSTRACTThe disassembly of host cell actin cytoskeleton as a facilitator ofTrypanosoma cruziinvasion has been reported by some authors, while other workers claim that it instead inhibits internalization of the parasite. In this study we aimed at elucidating the basis of this discrepancy. We performed experiments with metacyclic trypomastigotes ofT. cruzistrains G and CL, which differ markedly in infectivity and enter target cells by engaging the surface molecules gp35/50 and gp82, respectively, which have signaling activity. Treatment of HeLa cells with the F-actin-disrupting drug cytochalasin D or latrunculin B inhibited the invasion by strain G but not the invasion by strain CL. In contrast to cells penetrated by strain CL, which were previously shown to have a disrupted actin cytoskeleton architecture, no such alteration was observed in HeLa cells invaded by strain G, and parasites were found to be closely associated with target cell actin. Coinfection with enteroinvasiveEscherichia coli(EIEC), which recruits host cell actin for internalization, drastically reduced entry of strain CL into HeLa cells but not entry of strain G. In contrast to gp82 in its recombinant form, which induces disruption of F-actin and inhibits EIEC invasion, purified mucin-like gp35/50 molecules promoted an increase in EIEC uptake by HeLa cells. These data, plus the finding that drugs that interfere with mammalian cell signaling differentially affect the internalization of metacyclic forms of strains G and CL, indicate that the host cell invasion mediated by gp35/50 is associated with signaling events that favor actin recruitment, in contrast to gp82-dependent invasion, which triggers the signaling pathways leading to disassembly of F-actin.
Reversible Deficiency of Antimicrobial Polypeptides in Bacterial Vaginosis
Authors: Valore Erika V. , Wiley Dorothy J. , Ganz Tomas 
Published: September 2006

ABSTRACTBacterial vaginosis is a common condition associated with increased risk of sexually transmitted diseases, including human immunodeficiency virus infections. In contrast, vulvovaginal candidiasis has a much weaker association with sexually transmitted diseases. We found that vaginal lavage fluid from women with bacterial vaginosis is deficient in antimicrobial polypeptides and antimicrobial activity compared to fluid from healthy women or women with vulvovaginal candidiasis. Effective treatment normalized the concentrations of antimicrobial polypeptides in both bacterial vaginosis and in vulvovaginal candidiasis, suggesting that the abnormalities were a result of the diseases. Unlike in vulvovaginal candidiasis, the neutrophil attractant chemokine interleukin-8 (IL-8) was not increased in bacterial vaginosis, accounting for low concentrations of neutrophil-derived defensins in vaginal fluid. In organotypic cultures of human vaginal epithelium containing dendritic cells, treatment withLactobacillus jensenii, a typical vaginal resident, induced the synthesis of IL-8 mRNA and the epithelial human β-defensin-2 mRNA, but a typical bacterial vaginosis pathogen,Gardnerella vaginalis, had no effect. When the two bacteria were combined,Gardnerella vaginalisdid not interfere with the immunostimulatory effect ofLactobacillus jensenii. The loss of normal immunostimulatory flora in bacterial vaginosis is thus associated with a local deficiency of multiple innate immune factors, and this deficiency could predispose individuals to sexually transmitted diseases.
A DNA Prime-Modified Vaccinia Virus Ankara Boost Vaccine Encoding Thrombospondin-Related Adhesion Protein but Not Circumsporozoite Protein Partially Protects Healthy Malaria-Naive Adults against
Plasmodium falciparum
Sporozoite Challenge
Authors: Dunachie S. J. , Walther M. , Epstein J. E. , Keating S. , Berthoud T. , Andrews L. , Andersen R. F. , Bejon P. , Goonetilleke N. , Poulton I. , Webster D. P. , Butcher G. , Watkins K. , Sinden R. E. , Levine G. L. , Richie T. L. , Schneider J. , Kaslow D. , Gilbert S. C. , Carucci D. J. , Hill A. V. S. 
Published: September 2006

ABSTRACT

The safety, immunogenicity, and efficacy of DNA and modified vaccinia virus Ankara (MVA) prime-boost regimes were assessed by using either thrombospondin-related adhesion protein (TRAP) with a multiple-epitope string ME (ME-TRAP) or the circumsporozoite protein (CS) of
Plasmodium falciparum
. Sixteen healthy subjects who never had malaria (malaria-naive subjects) received two priming vaccinations with DNA, followed by one boosting immunization with MVA, with either ME-TRAP or CS as the antigen. Immunogenicity was assessed by ex vivo gamma interferon (IFN-γ) enzyme-linked immunospot assay (ELISPOT) and antibody assay. Two weeks after the final vaccination, the subjects underwent
P. falciparum
sporozoite challenge, with six unvaccinated controls. The vaccines were well tolerated and immunogenic, with the DDM-ME TRAP regimen producing stronger ex vivo IFN-γ ELISPOT responses than DDM-CS. One of eight subjects receiving the DDM-ME TRAP regimen was completely protected against malaria challenge, with this group as a whole showing significant delay to parasitemia compared to controls (
P
= 0.045). The peak ex vivo IFN-γ ELISPOT response in this group correlated strongly with the number of days to parasitemia (
P
= 0.033). No protection was observed in the DDM-CS group. Prime-boost vaccination with DNA and MVA encoding ME-TRAP but not CS resulted in partial protection against
P. falciparum
sporozoite challenge in the present study.
Effects of Psa and F1 on the Adhesive and Invasive Interactions ofYersinia pestiswith Human Respiratory Tract Epithelial Cells
Authors: Liu Fengzhi , Chen Huaiqing , Galván Estela M. , Lasaro Melissa A. , Schifferli Dieter M. 
Published: September 2006

ABSTRACTYersinia pestis, the causative agent of plague, expresses the Psa fimbriae (pH 6 antigen) in vitro and in vivo. To evaluate the potential virulence properties of Psa for pneumonic plague, anEscherichia colistrain expressing Psa was engineered and shown to adhere to three types of human respiratory tract epithelial cells. Psa binding specificity was confirmed with Psa-coated polystyrene beads and by inhibition assays. IndividualY. pestiscells were found to be able to express the capsular antigen fraction 1 (F1) concomitantly with Psa on their surface when analyzed by flow cytometry. To better evaluate the separate effects of F1 and Psa on the adhesive and invasive properties ofY. pestis, isogenic Δcaf(F1 genes), Δpsa, and ΔcafΔpsamutants were constructed and studied with the three respiratory tract epithelial cells. The Δpsamutant bound significantly less to all three epithelial cells compared to the parental wild-type strain and the Δcafand Δcaf Δpsamutants, indicating that Psa acts as an adhesin for respiratory tract epithelial cells. An antiadhesive effect of F1 was clearly detectable only in the absence of Psa, underlining the dominance of the Psa+phenotype. Both F1 and Psa inhibited the intracellular uptake ofY. pestis. Thus, F1 inhibits bacterial uptake by inhibiting bacterial adhesion to epithelial cells, whereas Psa seems to block bacterial uptake by interacting with a host receptor that doesn't direct internalization. The Δcaf Δpsadouble mutant bound and invaded all three epithelial cell types well, revealing the presence of an undefined adhesin(s) and invasin(s).
Down-Regulation of Key Virulence Factors Makes theSalmonella entericaSerovar TyphimuriumrfaHMutant a Promising Live-Attenuated Vaccine Candidate
Authors: Nagy Gábor , Danino Vittoria , Dobrindt Ulrich , Pallen Mark , Chaudhuri Roy , Emödy Levente , Hinton Jay C. , Hacker Jörg 
Published: September 2006

ABSTRACTMutants ofSalmonella entericaserovar Typhimurium that lack the transcriptional regulator RfaH are efficient as live oral vaccines against salmonellosis in mice. We show that the attenuation of the vaccine candidate strain is associated with reduced net growth in epithelial and macrophage cells. In order to identify the relevant RfaH-dependent genes, the RfaH regulon was determined withS. entericaserovars Enteritidis and Typhimurium using whole-genomeSalmonellamicroarrays. As well as impacting the expression of genes involved in lipopolysaccharide (LPS) core and O-antigen synthesis, the loss of RfaH results in a marked down-regulation of SPI-4 genes, the flagellum/chemotaxis system, and type III secretion system 1. However, a proportion of these effects could have been the indirect consequence of the altered expression of genes required for LPS biosynthesis. Direct and indirect effects of therfaHmutation were dissociated by genome-wide transcriptional profiling of a structural deep-rough LPS mutant (waaG). We show that truncation of LPS itself is responsible for the decreased intracellular yield observed for ΔrfaHstrains. LPS mutants do not differ in replication ability; rather, they show increased susceptibility to antimicrobial peptides in the intracellular milieu. On the other hand, evidence that deletion ofrfaH, as well as some other genes involved in LPS biosynthesis, results in enhanced invasion of various mammalian cells is shown. Exposure of common minor antigens in the absence of serovar-specific antigens might be responsible for the observed cross-reactive nature of the elicited immune response upon vaccination. Increased invasiveness of theSalmonella rfaHmutant into antigen-presenting cells, combined with increased intracellular killing and the potential for raising a cross-protective immune response, renders therfaHmutant an ideal vaccine candidate.
Differential Role of Lipooligosaccharide ofNeisseria meningitidisin Virulence and Inflammatory Response during Respiratory Infection in Mice
Authors: Zarantonelli Maria Leticia , Huerre Michel , Taha Muhamed-Kheir , Alonso Jean-Michel 
Published: September 2006

ABSTRACTMeningococcal lipooligosaccharide (LOS) induces a strong proinflammatory response in humans during meningococcal infection. We analyzed the role of LOS in the inflammatory response and virulence during the early infectious process in a mouse model of meningococcal respiratory challenge. AnlpxAmutant strain (serogroup B) devoid of LOS (strain Z0204) could not persist in the lungs and did not invade the blood. The persistence in the lungs and invasion of the bloodstream by arfaDmutant expressing truncated LOS with only lipid A and 3-deoxy-d-manno-2-octulosonic acid molecules (strain Z0401) was intermediate between those of the wild-type and Z0204 strains. Both LOS mutants induced acute pneumonia with the presence of infiltrating polymorphonuclear leukocytes in lungs. Although tumor necrosis factor alpha production was reduced in mice infected with the mutant of devoid LOS, both LOS mutants induced production of other proinflammatory cytokines, such as interleukin-1β (IL-1β), IL-6, and the murine IL-8 homolog KC. Together, these results suggest that meningococcal LOS plays a role during the early infectious and invasive process, and they further confirm that other, nonlipopolysaccharide components ofNeisseria meningitidismay significantly contribute to the inflammatory reaction of the host.
Measurement of Effector Protein Injection by Type III and Type IV Secretion Systems by Using a 13-Residue Phosphorylatable Glycogen Synthase Kinase Tag
Authors: Torruellas Garcia Julie , Ferracci Franco , Jackson Michael W. , Joseph Sabrina S. , Pattis Isabelle , Plano Lisa R. W. , Fischer Wolfgang , Plano Gregory V. 
Published: September 2006

ABSTRACT

Numerous bacterial pathogens use type III secretion systems (T3SSs) or T4SSs to inject or translocate virulence proteins into eukaryotic cells. Several different reporter systems have been developed to measure the translocation of these proteins. In this study, a peptide tag-based reporter system was developed and used to monitor the injection of T3S and T4S substrates. The glycogen synthase kinase (GSK) tag is a 13-residue phosphorylatable peptide tag derived from the human GSK-3β kinase. Translocation of a GSK-tagged protein into a eukaryotic cell results in host cell protein kinase-dependent phosphorylation of the tag, which can be detected with phosphospecific GSK-3β antibodies. A series of expression plasmids encoding Yop-GSK fusion proteins were constructed to evaluate the ability of the GSK tag to measure the injection of Yops by the
Yersinia pestis
T3SS. GSK-tagged YopE, YopH, LcrQ, YopK, YopN, and YopJ were efficiently phosphorylated when translocated into HeLa cells. Similarly, the injection of GSK-CagA by the
Helicobacter pylori
T4SS into different cell types was measured via phosphorylation of the GSK tag. The GSK tag provides a simple method to monitor the translocation of T3S and T4S substrates.
Inhibition of Matrix Metalloproteinases Protects Mice from Ascending Infection and Chronic Disease Manifestations Resulting from UrogenitalChlamydia muridarumInfection
Authors: Imtiaz Muhammad T. , Schripsema Justin H. , Sigar Ira M. , Kasimos John N. , Ramsey Kyle H. 
Published: September 2006

ABSTRACTMatrix metalloproteinases (MMP) are a family of host-derived enzymes involved in the turnover of extracellular matrix molecules. We have previously reported enhanced expression of matrix metalloproteinases inChlamydia muridarumurogenital tract infection of female mice. Kinetics and patterns of MMP expression as well as enhanced expression in susceptible strains of mice in the prior study implied a role for MMP in pathogenesis. To explore this further, we infected a susceptible strain of mice (C3H/HeN) withC. muridarumand treated two groups of mice with either one of two chemical inhibitors of MMP (MMPi; captopril and a chemically modified tetracycline) and reserved infected sham-treated mice as controls. Neither of the treatments affected shedding of viable chlamydiae from the lower urogenital tract, but the administration of either MMPi protected mice from the formation of hydrosalpinx—a surrogate marker of oviduct occlusion and infertility. Interestingly, the mechanism of protection for mice treated with chemically modified tetracycline 3, appeared to be related to prevention of ascending upper genital tract infection. These results imply that MMP are involved in pathogenesis of chlamydial infection in this model by mediating ascension of the infection into the upper genital tract.
Protective Antigen as a Correlative Marker for Anthrax in Animal Models
Authors: Kobiler David , Weiss Shay , Levy Haim , Fisher Morly , Mechaly Adva , Pass Avi , Altboum Zeev 
Published: September 2006

ABSTRACT

The most aggressive form of anthrax results from inhalation of airborne spores of
Bacillus anthracis
and usually progresses unnoticed in the early stages because of unspecific symptoms. The only reliable marker of anthrax is development of bacteremia, which increases with disease progress. Rapid diagnosis of anthrax is imperative for efficient treatment and cure. Herein we demonstrate that the presence and level of a bacterial antigen, the protective antigen (PA), a component of
B. anthracis
toxins, in host sera can serve as a reliable marker of infection. This was tested in two animal models of inhalation anthrax, rabbits and guinea pigs infected by intranasal instillation of Vollum spores. In both models, we demonstrated qualitative and quantitative correlations between levels of bacteremia and PA concentrations in the sera of sick animals. The average time to death in infected animals was about 16 h after the appearance of bacteremia, leaving a small therapeutic window. As the time required for immunodetection of PA can be very short, the use of this marker will be beneficial for faster diagnosis and treatment of inhalation anthrax.