bluuebunny/crossref_metadata_2025_split huggingface dataset:
High Level of Low‐density Lipoprotein Receptors Enhance Hypericin Uptake by U‐87 MG Cells in the Presence of LDL
Authors: Kascakova Slavka , Nadova Zuzana , Mateasik Anton , Mikes Jaromir , Huntosova Veronika , Refregiers Matthieu , Sureau Franck , Maurizot Jean‐Claude , Miskovsky Pavol , Jancura Daniel 
Published: October 2007

AbstractThe dependence of the uptake of hypericin (Hyp) by human glioma U‐87 MG cells on the level of expression of low‐density lipoprotein (LDL) receptors has been studied in this work. A special role of the LDL receptor‐pathway for Hyp delivery to U‐87 MG cells in the presence of LDL was revealed by the substantial increase of Hyp uptake in the situation, when the number of LDL receptors on the cell surface was elevated. Moreover, the colocalization experiments showed the lysosomal localization of Hyp following the uptake and that the concentration of Hyp in these organelles was enhanced in the cells with elevated number of LDL receptors when the incubation medium contained LDL. Both these findings suggest that LDL and LDL receptor‐pathway play an important role in the delivery and accumulation of Hyp into the cells.
The Influence of the Loop between Residues 223‐235 in Beetle Luciferase Bioluminescence Spectra: A Solvent Gate for the Active Site of pH‐Sensitive Luciferases
Authors: Viviani Vadim R. , Silva Neto Antonio J. , Arnoldi Frederico G. C. , Barbosa João A. R. G. , Ohmiya Yoshihiro 
Published: October 2007

AbstractBeetle luciferases emit a wide range of bioluminescence colors, ranging from green to red. Firefly luciferases can shift the spectrum to red in response to pH and temperature changes, whereas click beetle and railroadworm luciferases do not. Despite many studies on firefly luciferases, the origin of pH‐sensitivity is far from being understood. Through comparative site‐directed mutagenesis and modeling studies, using the pH‐sensitive luciferases (Macrolampis and Cratomorphus distinctus fireflies) and the pH‐insensitive luciferases (Pyrearinus termitilluminans, Phrixotrix viviani and Phrixotrix hirtus) cloned by our group, here we show that substitutions dramatically affecting bioluminescence colors in both groups of luciferases are clustered in the loop between residues 223‐235 (Photinus pyralis sequence). The substitutions at positions 227, 228 and 229 (P. pyralis sequence) cause dramatic redshift and temporal shift in both groups of luciferases, indicating their involvement in labile interactions. Modeling studies showed that the residues Y227 and N229 are buried in the protein core, fixing the loop to other structural elements participating at the bottom of the luciferin binding site. Changes in pH and temperature (in firefly luciferases), as well as point mutations in this loop, may disrupt the interactions of these structural elements exposing the active site and modulating bioluminescence colors.
Development and validation of an approach to produce large‐scale quantities of CpG‐methylated plasmid DNA
Authors: Fletcher Bradley S. 
Published: October 2007

SummaryThe prokaryotic CpG‐specific DNA methylase from Spiroplasma, SssI methylase, has been extensively used to methylate plasmid DNA in vitro to investigate the effects of methylation in vertebrate systems. Currently available methods to produce CpG‐methylated plasmid DNA have certain limitations and cannot generate large quantities of methylated DNA without cost or problems of purity. Here we describe an approach in which the SssI methylase gene has been introduced into the Escherichia coli bacterial genome under the control of an inducible promoter. Plasmid DNA propagated in this bacterium under conditions which induce the methylase gene result in significant (> 90%) CpG methylation. Methylated DNA produced by this approach behaves similarly to methylated DNA produced in vitro using the purified methylase. The approach is scalable allowing for the production of milligram quantities of methylated plasmid DNA.
Mutant HbpR transcription activator isolation for 2‐chlorobiphenyl via green fluorescent protein‐based flow cytometry and cell sorting
Authors: Beggah Siham , Vogne Christelle , Zenaro Elena , Van Der Meer Jan Roelof 
Published: October 2007

SummaryMutants were produced in the A‐domain of HbpR, a protein belonging to the XylR family of σ54‐dependent transcription activators, with the purpose of changing its effector recognition specificity from 2‐hydroxybiphenyl (2‐HBP, the cognate effector) to 2‐chlorobiphenyl (2‐CBP). Mutations were introduced in the hbpR gene part for the A‐domain via error‐prone polymerase chain reaction, and assembled on a gene circuitry plasmid in Escherichia coli, permitting HbpR‐dependent induction of the enhanced green fluorescent protein (egfp). Cells with mutant HbpR proteins responsive to 2‐CBP were enriched and separated in a flow cytometry‐assisted cell‐sorting procedure. Some 70 mutants were isolated and the A‐domain mutations mapped. One of these had acquired true 2‐CBP recognition but reacted hypersensitively to 2‐HBP (20‐fold more than the wild type), whereas others had reduced sensitivity to 2‐HBP but a gain of 2‐CBP recognition. Sequencing showed that most mutants carried double or triple mutations in the A‐domain gene part, and were not located in previously recognized conserved residues within the XylR family members. Further selection from a new mutant pool prepared of the hypersensitive mutant did not result in increased 2‐CBP or reduced 2‐HBP recognition. Our data thus demonstrate that a one‐step in vitro ‘evolutionary’ adaptation of the HbpR protein can result in both enhancement and reduction of the native effector recognition.
Self and Attitude Strength Parallels: Focus on Accessibility
Authors: DeMarree Kenneth G. , Petty Richard E. , Briñol Pablo 
Published: October 2007

AbstractNumerous parallels exist between the literatures on attitudes and the self, yet they are generally considered in isolation. In this paper, we focus on some parallels with respect to the concept of self‐strength – that is, aspects of self‐esteem and the self‐concept that impart the qualities of durability and impactfulness. Using research on attitude strength as our foundation, we first introduce some relevant strength variables such as accessibility, certainty, and ambivalence. Then, as a case study we review existing research on self‐view accessibility. Our review is organized based on parallel findings on attitude accessibility in order to demonstrate the utility of this approach. By considering research on attitude strength, we are able to organize, and in some cases reinterpret, previous self‐related findings, make new predictions regarding the self, and increase the precision of predictions. We believe that this approach can foster integration between the areas of attitudes and the self, advancing theory and research on both.
Induction of Cross-Serovar Protection against Genital Chlamydial Infection by a Targeted Multisubunit Vaccination Approach
Authors: Li Weidang , Guentzel M. Neal , Seshu J. , Zhong Guangming , Murthy Ashlesh K. , Arulanandam Bernard P. 
Published: October 2007

ABSTRACTAn important consideration for antichlamydial vaccine development is the induction of cross-serovar protection, since multiple serovars (D to L) ofChlamydia trachomatiscause genital infections. We have shown previously that vaccination withC. trachomatis-derived recombinant chlamydial protease-like activity factor (rCPAF) induced significant earlier resolution ofChlamydia muridaruminfection and reduced oviduct pathology. However, the vaccinated mice continued to shed chlamydiae for up to 2 weeks after challenge. In this study,C. trachomatisserovar D recombinant proteins, such as recombinant major outer membrane protein (rMOMP), recombinant inclusion membrane protein A (rIncA), and rCPAF were administered intranasally, individually or in combinations, with murine interleukin-12 (IL-12) as an adjuvant, and cross-species immunity against intravaginalC. muridaruminfection was examined. Immunization with rCPAF plus IL-12 (rCPAF+IL-12), compared to immunization with rIncA+IL-12 or rMOMP+IL-12, induced the greatest antigen-specific gamma interferon production from purified CD4+T cells and concurrently enhanced serum antibody production. All (100%) the animals vaccinated with rCPAF+IL-12 alone or in any combination completely resolved the infection by day 18 after challenge compared to animals vaccinated with rIncA+IL-12 (50%), rMOMP+IL-12 (33%), or phosphate-buffered saline (mock vaccinated; 0%). Moreover, oviduct pathology in mice vaccinated by any regimen that included rCPAF, but not rMOMP+IL-12 or rIncA+IL-12 alone, was markedly reduced compared to mock-immunized animals. The addition of rMOMP and/or rIncA did not significantly enhance the rCPAF+IL-12-induced effect on bacterial clearance or oviduct pathology. These results suggest a greater conservation of protective linear antigenic epitopes within CPAF than MOMP or IncA across the examined serovars and the need to identify other highly conserved antigens for use with rCPAF in a multisubunit recombinant vaccine.
Prevalence and Protein Specificity of Human Antibodies to Inkoo Virus Infection
Authors: Putkuri Niina , Vaheri Antti , Vapalahti Olli 
Published: October 2007

ABSTRACT

Inkoo virus (INKV), a member of the California serogroup orthobunyaviruses, is circulating widely in northern Europe. Although the virus was discovered over 40 years ago, the disease associations and immune responses in human infection are poorly characterized. We first developed an immunofluorescence assay (IFA) for the detection of INKV antibodies in humans, and then we studied a panel of 1,292 sera in patients with a febrile illness in Finland. We found four acute (immunoglobulin M [IgM] positive) INKV infections and an IgG seroprevalence of 51.3%. The data indicate that the infection has become more common than it was in the 1960s, especially in southern Finland. Two distinct IgG IFA fluorescence patterns were observed: a granular pattern in sera from patients with acute INKV infection and a diffuse pattern in those with long-standing immunity. Further analysis with a panel of INKV-positive sera (
n
= 18; verified by neutralization assay) of protein-specific responses, using immunoprecipitation and IFA based on baculovirus-expressed INK N, Gn, and Gc proteins, demonstrated a strong IgG response predominantly towards N protein in the acute phase. In contrast, in patients with long-standing immunity, the Gc response was more prominent and the N response was weaker. In conclusion, a diagnostic IgG IFA pattern distinguishing between acute infection and long-standing immunity was observed. N protein seems to be the optimal antigen for the serodiagnosis of acute infection, and the Gc protein could be appropriate for the serosurveillance of INKV.
Use of a Newly Developed β-Mercaptoethanol Enzyme-Linked Immunosorbent Assay To Diagnose Visceral Leishmaniasis in Patients in Eastern Sudan
Authors: Mansour Durria , Abass Elfadil M. , el Mutasim Mohamed , Mahamoud Abdelhafeiz , el Harith Abdallah 
Published: October 2007

ABSTRACTCorroboration of serology results is essential for restricting the risk of inappropriate antileishmanial prescription. A direct agglutination test (DAT) and a recently developed β-mercaptoethanol-modified enzyme-linked immunosorbent assay (β-ME ELISA) based on the use of antigen prepared as described for the DAT were applied to 416 sera from two Sudanese populations with and without clinical evidence of visceral leishmaniasis (VL). Of 285 sera with the lowest antileishmanial DAT titers (≤1:100 to 1:1,600), 270 (94.7%) scored comparable minimum β-ME ELISA absorbance values (≤0.1 to 0.26). In 117 sera that demonstrated the highest DAT titers (1:12,800 to ≥1:25,600), 86 (73.5%) scored maximum (0.81 to ≥1.35) and 30 (25.6%) medium (0.27 to 0.80) β-ME ELISA absorbance values. VL diagnosis was established for 142 (44.1%) patients in the VL-symptomatic group (n= 322), based on positive microscopy forLeishmania donovaniin lymph node aspirates or positive DAT (titer, ≥1:3,200). Of the 125 sera from the symptomatic patients for whom microscopy was positive for VL, 111 (88.8%) had comparable positive DAT and β-ME ELISA readings. In all 17 sera from the symptomatic DAT-positive patients for whom leishmaniasis was not established by microscopy but who responded favorably to antileishmanial therapy, absorbance values (≥0.27) indicative of VL were obtained by β-ME ELISA. Of 197 symptomatic patients for whom microscopy was negative for VL, 172 (87.3%) tested negative in β-ME ELISA and 180 (91.4%) in DAT. Based on the high reliability demonstrated here for VL detection, β-ME ELISA fulfills the requirement of confirming DAT results in patients manifesting suspected VL.
Development of an Effective Whole-Spore Vaccine To Protect against Microsporidial Gill Disease in Rainbow Trout (Oncorhynchus mykiss) by Using a Low-Virulence Strain ofLoma salmonae
Authors: Speare D. J. , Markham R. J. F. , Guselle N. J. 
Published: October 2007

ABSTRACTIn determining the effective vaccine spore dose of a low-virulence strain ofLoma salmonaeto limit microsporidial gill disease in trout, we found that fish receiving 103to 105killed spores had the best protection against experimental infection, with 85% fewer xenomas in their gills than in the controls. Intraperitoneal delivery of the vaccine was effective, and the addition of adjuvant did not improve vaccine performance against this disease-causing microsporidian.
AvrACXcc8004, a Type III Effector with a Leucine-Rich Repeat Domain fromXanthomonas campestrisPathovar campestris Confers Avirulence in Vascular Tissues ofArabidopsis thalianaEcotype Col-0
Authors: Xu Rong-Qi , Blanvillain Servane , Feng Jia-Xun , Jiang Bo-Le , Li Xian-Zhen , Wei Hong-Yu , Kroj Thomas , Lauber Emmanuelle , Roby Dominique , Chen Baoshan , He Yong-Qiang , Lu Guang-Tao , Tang Dong-Jie , Vasse Jacques , Arlat Matthieu , Tang Ji-Liang 
Published: October 2007

ABSTRACTXanthomonas campestrispathovar campestris causes black rot, a vascular disease on cruciferous plants, includingArabidopsis thaliana. The gene XC1553 fromX. campestrispv. campestris strain 8004 encodes a protein containing leucine-rich repeats (LRRs) and appears to be restricted to strains ofX. campestrispv. campestris. LRRs are found in a number of type III-secreted effectors in plant and animal pathogens. These prompted us to investigate the role of the XC1553 gene in the interaction betweenX. campestrispv. campestris andA. thaliana. Translocation assays using the hypersensitive-reaction-inducing domain ofX. campestrispv. campestris AvrBs1 as a reporter revealed that XC1553 is a type III effector. Infiltration ofArabidopsisleaf mesophyll with bacterial suspensions showed no differences between the wild-type strain and an XC1553 gene mutant; both strains induced disease symptoms on Kashmir and Col-0 ecotypes. However, a clear difference was observed when bacteria were introduced into the vascular system by piercing the central vein of leaves. In this case, the wild-type strain 8004 caused disease on the Kashmir ecotype, but not on ecotype Col-0; the XC1553 gene mutant became virulent on the Col-0 ecotype and still induced disease on the Kashmir ecotype. Altogether, these data show that the XC1553 gene, which was renamedavrACXcc8004, functions as an avirulence gene whose product seems to be recognized in vascular tissues.
Crystal Structure of the NADH:Quinone Oxidoreductase WrbA from
Escherichia coli
Authors: Andrade Susana L. A. , Patridge Eric V. , Ferry James G. , Einsle Oliver 
Published: October 2007

ABSTRACT

The flavoprotein WrbA, originally described as a tryptophan (
W
)
r
epressor-
b
inding protein in
Escherichia coli
, has recently been shown to exhibit the enzymatic activity of a NADH:quinone oxidoreductase. This finding points toward a possible role in stress response and in the maintenance of a supply of reduced quinone. We have determined the three-dimensional structure of the WrbA holoprotein from
E. coli
at high resolution (1.66 Å), and we observed a characteristic, tetrameric quaternary structure highly similar to the one found in the WrbA homologs of
Deinococcus radiodurans
and
Pseudomonas aeruginosa
. A similar tetramer was originally observed in an iron-sulfur flavoprotein involved in the reduction of reactive oxygen species. Together with other, recently characterized proteins such as YhdA or YLR011wp (Lot6p), these tetrameric flavoproteins may constitute a large family with diverse functions in redox catalysis. WrbA binds substrates at an active site that provides an ideal stacking environment for aromatic moieties, while providing a pocket that is structured to stabilize the ADP part of an NADH molecule in its immediate vicinity. Structures of WrbA in complex with benzoquinone and NADH suggest a sequential binding mechanism for both molecules in the catalytic cycle.
Aggregatibacter actinomycetemcomitansand Its Relationship to Initiation of Localized Aggressive Periodontitis: Longitudinal Cohort Study of Initially Healthy Adolescents
Authors: Fine Daniel H. , Markowitz Kenneth , Furgang David , Fairlie Karen , Ferrandiz Javier , Nasri Cebile , McKiernan Marie , Gunsolley John 
Published: October 2007

ABSTRACTAggregatibacter actinomycetemcomitansis frequently associated with localized aggressive periodontitis (LAP); however, longitudinal cohort studies relatingA. actinomycetemcomitansto initiation of LAP have not been reported. A periodontal assessment was performed on 1,075 primarily African-American and Hispanic schoolchildren, ages 11 to 17 years. Samples were taken from each child forA. actinomycetemcomitans. A cohort of 96 students was established that included a test group of 38A. actinomycetemcomitans-positive students (36 periodontally healthy and 2 with periodontal pockets) and 58 healthyA. actinomycetemcomitans-negative controls. All clinical and microbiological procedures were repeated at 6-month intervals. Bitewing radiographs were taken annually for definitive diagnosis of LAP. At the initial examination, clinical probing attachment measurements indicated that 1.2% of students had LAP, while 13.7% carriedA. actinomycetemcomitans, including 16.7% of African-American and 11% of Hispanic students (P= 0.001, chi-square test).A. actinomycetemcomitansserotypes a, b, and c were equally distributed among African-Americans; Hispanic students harbored predominantly serotype c (P= 0.05, chi-square test). In the longitudinal phase, survival analysis was performed to determine whetherA. actinomycetemcomitans-positive as compared toA. actinomycetemcomitans-negative students remained healthy (“survived”) or progressed to disease with attachment loss of >2 mm or bone loss (failed to “survive”). Students withoutA. actinomycetemcomitansat baseline had a significantly greater chance to remain healthy (survive) compared to theA. actinomycetemcomitans-positive test group (P= 0.0001). Eight of 38A. actinomycetemcomitans-positive and none of 58A. actinomycetemcomitans-negative students showed bone loss (P= 0.01).A. actinomycetemcomitansserotype did not appear to influence survival. These findings suggest that detection ofA. actinomycetemcomitansin periodontally healthy children can serve as a risk marker for initiation of LAP.
Bivalvular
Bartonella henselae
Prosthetic Valve Endocarditis
Authors: Vikram Holenarasipur R. , Bacani A. Kirstin , DeValeria Patrick A. , Cunningham Scott A. , Cockerill Franklin R. 
Published: October 2007

ABSTRACT

Prosthetic valve endocarditis is an uncommon manifestation of infection with
Bartonella
species. Herein, we report a case of
Bartonella henselae
endocarditis involving prosthetic mitral and aortic valves. The patient had a favorable outcome with combined medical and surgical therapy. Concomitant crescentic glomerulonephritis led to an initial mistaken diagnosis of Wegener's granulomatosis.
Prevalence of Methicillin-Resistant
Staphylococcus aureus
Nasal Colonization among Taiwanese Children in 2005 and 2006
Authors: Huang Yhu-Chering , Hwang Kao-Pin , Chen Po-Yen , Chen Chih-Jung , Lin Tzou-Yien 
Published: October 2007

ABSTRACT

From July 2005 to October 2006, a total of 3,046 children, of ages between 2 months and 5 years, presented for a well-child health care visit to one of three medical centers, which are located in the northern, central, and southern parts of Taiwan, and were surveyed for nasal carriage of methicillin-resistant
Staphylococcus aureus
(MRSA). The overall prevalences of
S. aureus
and MRSA nasal carriage among the children were 23% and 7.3%, respectively (18% and 4.8% in the central region, 25% and 6.7% in the southern region, and 27% and 9.5% in the northern region). Of the 212 MRSA isolates (96%) available for analysis, a total of 10 pulsed-field gel electrophoresis (PFGE) patterns with two major patterns (C [61%] and D [28%]) were identified. One hundred forty-nine isolates (70%) contained type IV staphylococcal cassette chromosome
mec
(SCC
mec
) DNA, and 55 isolates (26%) contained SCC
mec
V
T
. The presence of Panton-Valentine Leukocidin (PVL) genes was detected in 60 isolates (28%). Most MRSA isolates belonged to one of two major clones, characterized as sequence type 59 (ST59)/PFGE C/SCC
mec
IV/absence of PVL genes (59%) and ST59/PFGE D/SCC
mec
V
T
/presence of PVL genes (25%). We concluded that between 2005 and 2006, 7.3% of healthy Taiwanese children were colonized by MRSA in nares. MRSA harbored in healthy children indicates an accelerated spread in the community.
Prevalence of
Chlamydia trachomatis
Infection among Low- and High-Risk Filipino Women and Performance of
Chlamydia
Rapid Tests in Resource-Limited Settings
Authors: Saison Francis , Mahilum-Tapay Lourdes , Michel Claude-Edouard E. , Buttress Nigel D. , Nadala Elpidio Cesar B. , Magbanua Jose Paolo V. , Harding-Esch Emma M. , Villaruel M. Odeta , Canong Lorna , Celis Rey L. , Lee Helen H. 
Published: October 2007

ABSTRACT

The prevalence of urogenital
Chlamydia trachomatis
infection was determined with a PCR-based test of women from low- and high-risk populations in Iloilo City, Philippines, between August 2002 and March 2006. Two rapid tests for
C. trachomatis
, Clearview Chlamydia MF and the
Chlamydia
Rapid Test (CRT), were also evaluated in these resource-limited settings. Specimens were obtained from female sex workers (FSWs;
n
= 1,484) attending a social hygiene clinic (SHC) and from women (
n
= 838) attending an obstetrics-gynecology (OB-GYN) clinic. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the rapid tests were determined, with PCR as the gold standard. The PCR positivity rate for SHC participants (72% asymptomatic) ranged from 17.9 to 32.0% during the study period. Compared with those of PCR, the sensitivities and specificities of the Clearview test were 53.5 and 99.1%, respectively, with endocervical swab specimens (CS;
n
= 822) from the FSWs and 31.1 and 95.2%, respectively, with vaginal swab specimens (VS;
n
= 333) from these women. The sensitivity, specificity, PPV, and NPV of the CRT with VS from the FSWs were 71.0, 99.0, 97.1, and 87.9%, respectively. At the OB-GYN site, the PCR positivity rate with VS was 6.3%. The sensitivity, specificity, PPV, and NPV of the CRT with these specimens were 86.8, 99.6, 93.9, and 99.1%, respectively. The performance of the Clearview test at the SHC was thus markedly lower with VS than with CS, whereas the CRT performed well with VS from both populations.