bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Characterization of Lipooligosaccharide-Based Conjugate Vaccines for Serotype B
Moraxella catarrhalis
Authors: Yu Shengqing , Gu Xin-Xing 
Published: April 2005

ABSTRACT

Moraxella catarrhalis
is an important cause of otitis media in children and respiratory tract infections in the elderly. Lipooligosaccharide (LOS) is a major surface antigen of the bacterium that elicits bactericidal antibodies. Serological studies show that three major LOS types (A, B, and C) have been identified among clinical isolates. Our previous studies demonstrated that the type A LOS-based conjugates were immunogenic in animals. In this study, LOS from type B strain 26397 was detoxified and conjugated to tetanus toxoid (TT) or a cross-reactive mutant (CRM) of diphtheria toxin to form detoxified LOS (dLOS)-TT and dLOS-CRM, respectively, as vaccine candidates. The molar ratios of dLOS to TT and CRM in the conjugates were 43:1 and 19:1, respectively, while both weight ratios were around 0.9. The antigenicity of the conjugates was similar to that of the LOS, as determined by enzyme-linked immunosorbent assay using a rabbit antiserum to strain 26397. Subcutaneous immunization with each conjugate elicited a 180- to 230-fold rise of serum anti-LOS immunoglobulin G in mice and >2,000-fold rise in rabbits. In addition, both mouse and rabbit antisera showed elevated complement-mediated bactericidal activity against the homologous strain, and a representative rabbit antiserum showed bactericidal activity against nine of twelve clinical isolates studied. The bactericidal activity of the rabbit antiserum can be fully inhibited by the type B LOS but not the A or C LOS. These results indicate that the type B LOS-based conjugates can be used as vaccine components for further investigation.
Rapid Acquisition of Isolate-Specific Antibodies to Chondroitin Sulfate A-Adherent
Plasmodium falciparum
Isolates in Ghanaian Primigravidae
Authors: Cox Sharon E. , Staalsoe Trine , Arthur Paul , Bulmer Judith N. , Hviid Lars , Yeboah-Antwi Kojo , Kirkwood Betty R. , Riley Eleanor M. 
Published: April 2005

ABSTRACT

Recent evidence suggests that pregnancy-associated malaria (PAM), associated with maternal anemia and low birth weight, results from preferential sequestration of parasitized red blood cells (pRBC) in the placenta via binding of variant surface antigens (VSA) expressed on the surface of pRBC to chondroitin sulfate A (CSA). The VSA mediating CSA binding (VSA
CSA
) and thus sequestration of pRBC in the placenta are antigenically distinct from those that mediate pRBC sequestration elsewhere in the body, and it has been suggested that VSA
CSA
are relatively conserved and may thus constitute an attractive target for vaccination against PAM. Using flow cytometry, levels of antibody to VSA and VSA
CSA
expressed on the surface of red blood cells infected with
Plasmodium falciparum
isolates were measured during pregnancy and lactation in Ghanaian primigravid women enrolled in a trial of maternal vitamin A supplementation. Antibody responses to VSA
CSA
were detected within the first trimester of pregnancy and increased with increasing duration of pregnancy, and they seemed to be isolate specific, indicating that different CSA-adherent parasite lines express antigenically distinct VSA and thus may not be as antigenically conserved as has been previously suggested. Levels of anti-VSA
CSA
were not significantly associated with placental malarial infection determined by histology, indicating that primary immune responses to VSA
CSA
may not be sufficient to eradicate placental parasitemia in primigravidae.
Laccase Expression in Murine Pulmonary
Cryptococcus neoformans
Infection
Authors: Garcia-Rivera Javier , Tucker Stephanie C. , Feldmesser Marta , Williamson Peter R. , Casadevall Arturo 
Published: April 2005

ABSTRACT

Cryptococcus neoformans
laccase expression during murine infection was investigated in lung tissue by immunohistochemistry and immunogold electron microscopy. Laccase was detected in the fungal cell cytoplasm, cell wall, and capsule in vivo. The amount of laccase found in different sites varied as a function of the time of infection.
Surface Analyses and Immune Reactivities of Major Cell Wall-Associated Proteins of Group A Streptococcus
Authors: Cole Jason N. , Ramirez Ruben D. , Currie Bart J. , Cordwell Stuart J. , Djordjevic Steven P. , Walker Mark J. 
Published: April 2005

ABSTRACT

A proteomic analysis was undertaken to identify cell wall-associated proteins of
Streptococcus pyogenes
. Seventy-four distinct cell wall-associated proteins were identified, 66 of which were novel. Thirty-three proteins were immunoreactive with pooled
S. pyogenes
-reactive human antisera. Biotinylation of the GAS cell surface identified 23 cell wall-associated proteins that are surface exposed.
Regulation of the Mitogen-Activated Protein Kinases byBrucellaspp. Expressing a Smooth and Rough Phenotype: Relationship to Pathogen Invasiveness
Authors: Jiménez de Bagüés María P. , Gross Antoine , Terraza Annie , Dornand Jacques 
Published: April 2005

ABSTRACTBy comparing smooth wild-typeBrucellaspp. to their rough mutants, we show that the LPS O chain restricted the activation of the ERK1/2 and p38 mitogen-activated protein kinase (MAPK) pathways, thus preventing the synthesis of immune mediators that regulate host defense. We conclude that the MAPKs are a target for immune intervention by virulent smoothBrucella.
The Purinergic P2X7 Receptor Is Not Required for Control of Pulmonary
Mycobacterium tuberculosis
Infection
Authors: Myers Amy J. , Eilertson Brandon , Fulton Scott A. , Flynn JoAnne L. , Canaday David H. 
Published: April 2005

ABSTRACT

The importance in vivo of P2X7 receptors in control of virulent
Mycobacterium tuberculosis
was examined in a low-dose aerosol infection mouse model. P2X7
−/−
mice controlled infection in lungs as well as wild-type mice, suggesting that the P2X7 receptor is not required for control of pulmonary
M. tuberculosis
infection.
Patient-Active Prevention in Primary Dental Care: A Characterisation of General Practices in Northern Ireland
Authors: Freeman Ruth , Kerr Gail , Salmon Kathy , Speedy Patti 
Published: April 2005

Aim To investigate the preventive orientation of general dental practices by examining their patient-active prevention activities, practice policies for prevention and employment strategies. Method All general dental practices located within the region of the Eastern Health and Social Services Board (EHSSB) in Northern Ireland were contacted and invited to participate. A questionnaire assessed practice characteristics, patient-active prevention, practice policies and employment strategies. The principal general dental practitioner (GDP) was invited to complete the questionnaire. Results Seventy-seven per cent of practices participated. Nearly all the practices provided patient-active prevention; however, lower proportions of dentists provided advice on diet for dental caries (3%), oral hygiene instruction, fluoride toothpaste use and interdental cleaning (7%) with each new course of dental treatment. ‘Patient-active’ prevention practices were 5.8 times more likely to employ a hygienist and 5.3 times more likely to have a practice policy to screen for oral cancer. Conclusions These findings suggest that the employment of a hygienist is central to the reorientation of primary dental care. The Government must be encouraged to provide the financial means to allow primary care to shift from being disease-centred to health-focused.
Effects of Activated Platelet Concentrates on Human Primary Cultures of Fibroblasts and Osteoblasts
Authors: Cenni E. , Ciapetti G. , Pagani S. , Perut F. , Giunti A. , Baldini N. 
Published: April 2005

Background: Platelet alpha granules contain growth factors released into the surrounding environment during activation. This property has been used in clinical medicine to accelerate the repair process by activating in vitro autologous platelets with thrombin and has also been proposed to promote the proliferation of bone cells. The aim of this research was to assess the effect of platelet concentrates activated with thrombin on human gingival fibroblasts and human osteoblasts from trabecular bone.Methods: Platelet concentrates, activated with bovine thrombin, were added to the cells in serum‐free medium. The cultures were assessed for proliferation by vital stain and cell count after 72‐hour incubation. Alkaline phosphatase activity was tested after 72‐hour incubation on the osteoblast lysates by a colorimetric assay. After 21 days the formation of mineral nodules was tested in the osteoblast cultures by alizarin red staining. The effects of the activated platelet concentrates (APC) were compared with the serum‐free medium (SF), or with platelet‐poor plasma added medium (PPP).Results: The fibroblast growth in the presence of APC was higher, though not significantly, than SF. APC resulted in a nonsignificant decrease in proliferation and alkaline phosphatase expression in osteoblasts, compared both to serum free medium, and PPP. Mineralization was only modestly increased after incubation with APC in comparison with serum‐free medium.Conclusions: There were no statistical differences in fibroblast proliferation, or in osteoblast growth and functions between serum‐free conditions and the platelet gel treatment. Therefore, neither fibroblast proliferation nor osteoblast growth and functions were affected by the activated platelet concentrates in vitro. J Periodontol 2005;76:323‐328.
Inhibitory Effects of Areca Nut Extracts on Phagocytosis of Actinobacillus actinomycetemcomitans ATCC 33384 by Neutrophils
Authors: Hung Shan‐Ling , Cheng Yi‐Yun , Peng Ji‐Lung , Chang Lien‐Yu , Liu Tsung‐Yun , Chen Yen‐Ting 
Published: April 2005

Background: Areca quid chewers have a higher prevalence of periodontal disease than non‐chewers. Little is known about the influence of areca quid on the immune system. This study was to determine the possible effects of the areca nut on phagocytic activity of human neutrophils.Methods: Aqueous extracts of ripe areca nut without husk (rANE), fresh and tender areca nut with husk (tANE), a major alkaloid (arecoline), and a phenolic component ([+]‐catechin) of areca nut were examined for their effects on cellular viability using trypan blue exclusion assay. The possible effects on the phagocytic activity of neutrophils against a periodontal pathogen, Actinobacillus actinomycetemcomitans ATCC 33384, were determined using flow cytometry and confocal laser scanning microscopy.Results: At the concentrations tested, rANE, tANE, arecoline, and (+)‐catechin did not significantly affect viability of neutrophils. However, rANE, tANE, arecoline, and (+)‐catechin inhibited the phagocytic activity of neutrophils in a dose‐dependent manner. Approximately 50% of the relative phagocytic activity of neutrophils was affected when 50 µg/ml of rANE, 400 µg/ml of tANE, 20,000 µg/ml of arecoline, or 2,500 µg/ml of (+)‐ catechin was used. Decreased levels of internalized fluorescent bacteria were also demonstrated. However, arecoline or (+)‐catechin alone could not be used to explain the inhibitory effects observed for rANE and tANE.Conclusions: Components of areca nut reduced the uptake of A. actinomycetemcomitans ATCC 33384 by human neutrophils. The inhibition of areca nut on phagocytosis of neutrophils may be one possible mechanism by which the areca nut compromises the periodontal health of areca quid chewers. J Periodontol 2005;76:373‐379.
Depletion of Polyamines and Increase of Transforming Growth Factor‐β1, c‐myc, Collagen‐Type I, Matrix Metalloproteinase‐1, and Metalloproteinase‐2 mRNA in Primary Human Gingival Fibroblasts
Authors: Stabellini Giordano , Moscheni Claudia , Gagliano Nicoletta , Dellavia Claudia , Calastrini Carla , Ferioli Maria Elena , Gioia Magda 
Published: April 2005

Background: The polyamines spermidine, spermine, and putrescine are known to be deeply linked with growth processes, gene expression, and extracellular matrix synthesis. Their cellular content depends primarily on the activity of the enzyme ornithine decarboxylase. High levels of ornithine decarboxylase and polyamines have been found in proliferative, inflammatory, and neoplastic pathologies of the oral cavity and in gingival fluid. Difluoromethylornithine (DFMO) selectively inhibits ornithine decarboxylase, thus depleting polyamine content and preventing cell proliferation and synthesis activity. The aim of this study was to investigate whether DFMO treatment could modify the genes involved in cell proliferation and extracellular matrix turnover.Methods: Fibroblasts derived from non‐inflamed gingiva were maintained in Dulbecco's modified Eagle's medium (DMEM) plus α‐difluoromethylornithine for 4 days. At 0, 24, 48, 72, and 96 hours cell number was assessed, polyamine levels were quantified with high performance liquid chromatography (HPLC) method, and transforming growth factor‐β1 (TGF‐β1), c‐myc, matrix metalloproteinases (MMP)‐1 and 2, collagen type I (COL‐I) and tissue inhibitor of matrix metalloproteinases (TIMP)‐1 were evaluated by reverse transcriptionpolymerase chain reaction (RT‐PCR).Results: Fibroblasts treated with DFMO significantly decreased cell proliferation, ornithine decarboxylase activity, and putrescine levels at all treatment times, spermidine after 72 and 96 hours, and spermine after 96 hours of culture. Total polyamines decreased (P ≤0.01) at 96 hours after DFMO treatment, while c‐myc, TGF‐β1, MMP‐1 and 2, COL‐I mRNA significantly increased. Conversely, TIMP‐1 did not show any significant change. The polyamines trend was not correlated to c‐myc, TGF‐β1, MMP‐1 and ‐2, and TIMP‐1 mRNA levels. Transforming growth factor‐β1 and c‐myc mRNA expression were related and correlated to MMP‐1 and 2, COL‐I and TIMP‐1 mRNA trend after DFMO treatment.Conclusions: Our data show that as the polyamine content decreases, TGF‐β1, c‐myc, MMP‐1 and ‐2, and COL‐I mRNA levels increase, therefore a negative regulatory role of the polyamines on the mRNA expression could be suggested. J Periodontol 2005;76:443‐449.
On efficiently solving a class of atmospheric radiative transfer problems using discrete ordinates models for bidirectional functions: the uppermost layer
Authors: de Abreu Marcos Pimenta 
Published: April 2005

AbstractWe derive discrete models for bidirectional functions defined for the uppermost layer of a multislab model atmosphere. These models can be used to solve efficiently a set of multislab transfer problems characterized by an optically stationary uppermost layer. We illustrate with numerical results for a representative set of multislab problems. Copyright © 2005 Royal Meteorological Society
Synthesis, Structural Features, Absorption Spectra, Redox Behaviour and Luminescence Properties of Ruthenium(II) Rack‐Type Dinuclear Complexes with Ditopic, Hydrazone‐Based Ligands
Authors: Stadler Adrian‐Mihail , Puntoriero Fausto , Campagna Sebastiano , Kyritsakas Nathalie , Welter Richard , Lehn Jean‐Marie 
Published: April 2005

AbstractThe isomeric bis(tridentate) hydrazone ligand strands 1 a–c react with [Ru(terpy)Cl3] (terpy=2,2′:6′,2′′‐terpyridine) to give dinuclear rack‐type compounds 2 a–c, which were characterised by several techniques, including X‐ray crystallography and NMR methods. The absorption spectra, redox behaviour and luminescence properties (both in fluid solution at room temperature and in rigid matrix at 77 K) of the ligand strands 1 a–c and of the metal complexes 2 a–c have been studied. Compounds 1 a–c exhibit absorption spectra dominated by intense π–π* bands, which, in the case of 1 b and 1 c, extend within the visible region, while the absorption spectra of the rack‐type complexes 2 a–c show intense bands both the in the UV region, due to spin‐allowed ligand‐centred (LC) transitions, and in the visible, due to spin‐allowed metal‐to‐ligand charge‐transfer (MLCT) transitions. The energy position of these bands strongly depends on the ligand strand: in the case of 2 a, the lowest energy MLCT band is around 470 nm, while in 2 b and 2 c, it lies beyond 600 nm. Ligands 1 a–c undergo oxidation processes that involve orbitals based mainly on the CH3NN fragments. The complexes 2 a–c undergo reversible metal‐centred oxidation, while reductions involve the hydrazone‐based ligands: in 2 b and 2 c, the bridging ligand is reduced twice and in 2 a once before reduction of the peripheral terpy ligands takes place. Ligands 1 a–c exhibit luminescence from the lowest‐lying 1π–π* level. Only for complex 2 a does emission occur; this may be attributed to a 3MLCT state involving the bridging ligand. Taken together, the results clearly indicate that the structural variations introduced translate into interesting differences in the spectroscopic, luminescence and redox properties of the ligand strands as well as of the rack‐type metal complexes.
EPR, ENDOR, and DFT Studies on (β‐Octahalo‐meso‐tetraarylporphyrin)copper Complexes: Characterization of the Metal(d)−Porphyrin(a2u) Orbital Interaction
Authors: Shao Junlong , Steene Erik , Hoffman Brian M. , Ghosh Abhik 
Published: April 2005

AbstractA series of planar (porphyrin)copper(II) complexes and their β‐octahalogenated saddled derivatives have been studied by Electron Paramagnetic Resonance (EPR) spectroscopy, Electron Nuclear DOuble Resonance (ENDOR) spectroscopy, and Density Functional Theoretical (DFT) calculations. Both EPR/ENDOR spectroscopy and DFT calculations indicate a decrease in spin density on the central copper(II) ion and on the nitrogen atoms in the saddled compounds relative to the planar complexes. The EPR/ENDOR measurements show that the hyperfine coupling decreases by 12% on the nitrogen atoms and 9% on the copper ion, in going from planar (5,10,15,20‐tetraphenylporphyrin)copper (Cu[TPP]) to saddled (2,3,7,8,12,13,17,18‐octabromo‐5,10,15,20‐tetraphenylporphyrin)copper (Cu[Br8TPP]). Accordingly, saddling results in a decrease in the spin density on the copper ion and on the nitrogen atoms. DFT calculations on Cu[Br8TPP] yield spin populations of 42.4% on the copper ion, 9.9% on each nitrogen atom and 4.9% on each meso carbon atom, relative to DFT spin populations of 62, 10.2 and 0.3% on the copper ion, each nitrogen and each meso carbon atom, respectively, for porphinecopper (Cu[P]). These calculations further indicate that the decrease in spin density on the copper ion in the saddled complexes results from a saddling‐induced Cu(d)−porphyrin(a2u) orbital overlap whereby some of the Cu spin density is delocalized onto the porphyrin ring. The decrease in nitrogen spin population with saddling appears to be a more subtle effect caused by a superposition of two opposing factors. Saddling decreases the overlap between the nitrogen lone pairs and the Cu d orbital on one hand and enhances the overlap between the copper d orbital and the porphyrin a2u HOMO on the other. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
A Copper‐Metalated, Hybrid Inorganic–Organic Polymer as an Oxidative Nuclease
Authors: Chandrasekhar Vadapalli , Athimoolam Arunachalampillai , Krishnan Venkatasubbaiah , Azhakar Ramachandran , Madhavaiah C. , Verma Sandeep 
Published: April 2005

AbstractThis study describes nucleolytic activity of a copper‐metalated, multisite‐coordinating, hybrid polymer CPPL‐Cu under oxidative conditions. Rapid relaxation of supercoiled plasmid DNA was observed and mechanistic probing by chemical and enzymatic assays revealed involvement of singlet‐oxygen‐derived reactive species. The heterogeneous nature of the catalyst allowed a facile recycling of the artificial nuclease. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Synthesis, Structure, and Luminescent Properties of Guanidinate‐Based Terbium Complexes
Authors: Pang Xingan , Sun Hongmei , Zhang Yong , Shen Qi , Zhang Hongjie 
Published: April 2005

AbstractTwo guanidinate‐based terbium complexes [iPrNC(NiPr2)NiPr]mTbCl3–m [m = 3 (1), 2 (2)] were synthesized, and the crystal structure of 1 was determined by single‐crystal X‐ray diffraction. Complexes 1 and 2 were further characterized by elemental analysis, IR, and 1H NMR spectroscopy. In complex 1 the guanidinate ligand coordinates to the terbium atom through the nitrogen atoms in a bidentate chelating coordination mode. As a result of an efficient energy transfer from the guanidinate ligand to the central Tb3+, both 1 and 2 have been found to exhibit strong green emission corresponding to Tb3+ 5D4‐7FJ (J = 6, 5, 4, 3) transitions. Among them, the emission 5D4‐7F5 (550 nm) is the most prominent. The lifetimes of the 5D4 Tb3+ excited levels of the two complexes were determined to be around 0.90 ms. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Mixed f‐d Metallomesogens with an Extended Rigid Core
Authors: Binnemans Koen , Lodewyckx Katleen , Donnio Bertrand , Guillon Daniel 
Published: April 2005

AbstractThe liquid‐crystalline behaviour of copper(II) and nickel(II) complexes of a mesogenic Schiff‐base ligand derived from N,N'‐disalicylidene‐1,2‐phenylenediamine (salophenH2) and of the corresponding trinuclear mixed copper(II)/lanthanum(III) and nickel(II)/lanthanum(III) complexes was investigated. High‐temperature X‐ray diffraction studies revealed that both the parent transition metal complexes and the mixed f‐d complexes exhibit a hexagonal columnar phase (Colh) over an extended temperature range. Complex formation with lanthanum(III) nitrate resulted in an increase of the transition temperatures. The geometrical parameters (lattice parameters and column cross‐section) of all the metal complexes are very similar, which indicates that the local organisation in the mesophase is the same despite their structural differences. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Reductive Isopropyl Radical Elimination from (dpp‐bian)Mg‐iPr(Et2O)
Authors: Fedushkin Igor L. , Skatova Alexandra A. , Hummert Markus , Schumann Herbert 
Published: April 2005

AbstractThe reaction of (dpp‐bian)Na(Et2O) with one equiv. of iPrMgCl in hexane affords (dpp‐bian)Mg‐iPr(Et2O) (1) whereas (dpp‐bian)Mg(Et2O)2 (2) is formed when this reaction is carried out in Et2O as a result of isopropyl radical elimination. Compound 1 which is stable in hexane and Et2O also decomposes in THF with elimination of isopropyl radicals yielding (dpp‐bian)Mg(THF)2. The reaction of (dpp‐bian)Na2(Et2O)3 with two equiv. of iPrMgCl in Et2O produces 2 and iPr2Mg, which then interact to give (dpp‐bian)(Mg‐iPr)2(Et2O) (3) when treated with hexane or toluene. Compounds 1–3 were characterized by elemental analysis, UV/Vis and NMR spectroscopy, as well as by single‐crystal X‐ray diffraction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)