bluuebunny/crossref_metadata_2025_split huggingface dataset:
Platelet Aggregation Induced by Serotype Polysaccharides fromStreptococcus mutans
Authors: Chia Jean-San , Lin Ya-Lin , Lien Huei-Ting , Chen Jen-Yang 
Published: April 2004

ABSTRACTPlatelet aggregation plays an important role in the pathogenesis of infective endocarditis induced by viridans streptococci or staphylococci. Aggregation induced in vitro involves direct binding of bacteria to platelets through multiple surface components. Using platelet aggregometry, we demonstrated in this study that twoStreptococcus mutanslaboratory strains, GS-5 and Xc, and two clinical isolates could aggregate platelets in an irreversible manner in rabbit platelet-rich plasma preparations. The aggregation was partially inhibited by prostaglandin I2(PGI2) in a dose-dependent manner. Whole bacteria and heated bacterial cell wall extracts were able to induce aggregation. Cell wall polysaccharides extracted from the wild-type Xc strain, containing serotype-specific polysaccharides which are composed of rhamnose-glucose polymers (RGPs), could induce platelet aggregation in the presence of plasma. Aggregation induced by the serotype-specific RGP-deficient mutant Xc24R was reduced by 50% compared to the wild-type strain Xc. In addition, cell wall polysaccharides extracted from Xc24R failed to induce platelet aggregation. The Xc strain, but not the Xc24R mutant, could induce platelet aggregation when preincubated with plasma. Both Xc and Xc24R failed to induce platelets to aggregate in plasma depleted of immunoglobulin G (IgG), but aggregation was restored by replenishment of anti-serotype c IgG. Analysis by flow cytometry showed thatS. mutansRGPs could bind directly to rabbit and human platelets. Furthermore, cell wall polysaccharides extracted from the Xc, but not the Xc24R, strain could induce pseudopod formation of both rabbit and human platelets in the absence of plasma. Distinct from the aggregation of rabbit platelets, bacterium-triggered aggregation of human platelets required a prolonged lag phase and could be blocked completely by PGI2. RGPs also trigger aggregation of human platelets in a donor-dependent manner, either as a transient and reversible or a complete and irreversible response. These results indicated that serotype-specific RGPs, a soluble product ofS. mutans, could directly bind to and activate platelets from both rabbit and human. In the presence of plasma containing IgG specific to RGPs, RGPs could trigger aggregation of both human and rabbit platelets, but the degree of aggregation in human platelets depends on the donors.
Prevention of Pneumococcal Disease in Mice Immunized with Conserved Surface-Accessible Proteins
Authors: Hamel Josée , Charland Nathalie , Pineau Isabelle , Ouellet Catherine , Rioux Stéphane , Martin Denis , Brodeur Bernard R. 
Published: April 2004

ABSTRACT

The development of a vaccine against
Streptococcus pneumoniae
has been complicated by the existence of at least 90 antigenically distinct capsular serotypes. Common protein-based vaccines could represent the best strategy to prevent pneumococcal infections, regardless of serotype. In the present study, the immunoscreening of an
S. pneumoniae
genomic library allowed the identification of a novel immune protein target, BVH-3. We demonstrate that immunization of mice with BVH-3 elicits protective immunity against experimental sepsis and pneumonia. Sequence analysis revealed that the
bvh-3
gene is highly conserved within the species. Since the BVH-3 protein shows homology at its amino-terminal end with other pneumococcal proteins, it was of interest to determine if protection was due to the homologous or to the protein-specific regions. Immunoprotection studies using recombinant BVH-3 and BVH-3-related protein fragments as antigens allowed the localization of surface-exposed and protective epitopes at the protein-specific carboxyl termini, thus establishing that BVH-3 is distinct from other previously reported protective protein antigens. Immunization with a chimeric protein comprising the carboxyl-terminal regions of BVH-3 and of a BVH-3-related protein improved the protection by targeting two surface pneumococcal components. Thus, BVH-3 and the chimeric protein hold strong promise as vaccine components to control pneumococcal disease.
pagPIs Required for Resistance to Antibody-Mediated Complement Lysis duringBordetella bronchisepticaRespiratory Infection
Authors: Pilione Mylisa R. , Pishko Elizabeth J. , Preston Andrew , Maskell Duncan J. , Harvill Eric T. 
Published: April 2004

ABSTRACTTo efficiently colonize and persist in the lower respiratory tract, bacteria must survive multiple host immune mechanisms.Bordetella bronchisepticais a gram-negative respiratory pathogen that naturally infects mice and persists in the lower respiratory tract for up to 49 days postinoculation. In this work, we examined the effect of mutation of thepagPgene on the persistence ofB. bronchisepticain the lower respiratory tract of mice. ThepagPgene encodes a palmitoyl transferase that is responsible for the addition of a palmitoyl group to the lipid A region ofB. bronchisepticalipopolysaccharide. Data presented here confirm that aB. bronchisepticaΔpagPmutant demonstrates defective persistence in the lower respiratory tract of wild-type mice. We hypothesized that the defective persistence of theB. bronchisepticaΔpagPmutant was due to an increased susceptibility of this mutant to a host immune response. In vivo data indicate that both B cells and the complement component C3 are required for the reduced bacterial numbers of the ΔpagPmutant on day 14 postinoculation. In addition, an in vitro complement killing assay demonstrated thatB. bronchisepticaexhibitspagP-dependent resistance to antibody-mediated complement killing at low concentrations of immune serum. Taken together, these results suggest thatpagPis required forB. bronchisepticato resist antibody-mediated complement lysis during respiratory infection.
Glycosylation of
Anaplasma marginale
Major Surface Protein 1a and Its Putative Role in Adhesion to Tick Cells
Authors: Garcia-Garcia Jose C. , de la Fuente José , Bell-Eunice Gianna , Blouin Edmour F. , Kocan Katherine M. 
Published: April 2004

ABSTRACT

Anaplasma marginale
, the causative agent of bovine anaplasmosis, is a tick-borne rickettsial pathogen of cattle that multiplies in erythrocytes and tick cells. Major surface protein 1a (MSP1a) and MSP1b form the MSP1 complex of
A. marginale
, which is involved in adhesion of the pathogen to host cells. In this study we tested the hypothesis that MSP1a and MSP1b were glycosylated, because the observed molecular weights of both proteins were greater than the deduced molecular masses. We further hypothesized that the glycosylation of MSP1a plays a role in adhesion of
A. marginale
to tick cells. Native and
Escherichia coli
-derived recombinant MSP1a and MSP1b proteins were shown by gas chromatography to be glycosylated and to contain neutral sugars. Glycosylation of MSP1a appeared to be mainly O-linked to Ser/Thr residues in the N-terminal repeated peptides. Glycosylation may play a role in adhesion of
A. marginale
to tick cells because chemical deglycosylation of MSP1a significantly reduced its adhesive properties. Although the MSP1a polypeptide backbone alone was adherent to tick cell extract, the glycans in the N-terminal repeats appeared to enhance binding and may cooperatively interact with one or more surface molecules on host cells. These results demonstrated that MSP1a and MSP1b are glycosylated and suggest that the glycosylation of MSP1a plays a role in the adhesion of
A. marginale
to tick cells.
PheP, a Putative Amino Acid Permease of
Staphylococcus aureus
, Contributes to Survival In Vivo and during Starvation
Authors: Horsburgh Malcolm J. , Wiltshire Michael D. , Crossley Howard , Ingham Eileen , Foster Simon J. 
Published: April 2004

ABSTRACT

PheP, a putative amino acid permease in
Staphylococcus aureus
, contributes to starvation survival under glucose-limiting conditions and virulence. A
pheP
mutation led to poor growth after microaerobic or anaerobic incubation on pig serum agar, which was recovered by phenylalanine addition. Genetic complementation of
pheP
restored growth and starvation survival.
The Influence of Cooling Rate on the Fracture Properties of a Thermoplastic-Based Fibre-Metal Laminate
Authors: Guillén J. F. , Cantwell W. J. 
Published: April 2004

This paper investigates the effect of varying cooling rate on the mechanical properties of a novel fibre metal laminate based on glass-fibre polypropylene. Differential scanning calorimetry (DSC) and polarised light microscopy have been used to identify differences in the matrix morphology resulting from varying the processing conditions. Additionally, the residual stresses in simple bi-material samples manufactured under different cooling conditions were quantified in order to understand the effect of the cooling rate on the mechanical properties of these multilayered materials. The results indicate that the residual stresses were greater in the fast cooled samples, whereas the degree of crystallinity was higher in slow cooled samples. The results highlight a strong link between processing conditions and mechanical properties under both fibre and matrix-dominated modes of loading. The flexural properties of the plain composites and the fibre-metal laminates were greater at the low cooling rates. Conversely, the tensile strength and interlaminar toughness for both types of material were greater for specimens manufactured using high cooling rates. Finally, faster cooling was shown to yield laminates with a superior impact resistance. It is believed that the rapid cooling of the laminates enhanced their resistance to interlaminar fracture, which in turn resulted in smaller damage areas after impact.
Effects of Moisture Conditioning Methods on Mechanical Properties of Injection Molded Nylon 6
Authors: Jia Nanying , Fraenkel Howard A. , Kagan Val A. 
Published: April 2004

The influence of various standard (ASTM, ISO) and experimental moisture conditioning methods on mechanical performance of injection molded nylon 6 is discussed as a result of an in-depth, comprehensive investigation. These methods covered a wide range for two basic process parameters for conditioning: temperature (from 23 to 100 C) and relative humidity (from 50% RH to water immersion). The variation of these parameters may result in significantly different moisture absorption rates, equilibrium levels and mechanical properties. The kinetics of mechanical performance and microstructure were evaluated prior to tests and during conditioning in this comprehensive analysis. The results from this investigation may provide comprehensive, up-to-date information and recommendations concerning accelerated nylon conditioning methods for test specimens and various molded parts, preselection of nylon based plastic for design, and prediction and optimization of mechanical performance.
Effect of peak expiratory flow data quantity on diagnostic sensitivity and specificity in occupational asthma
Authors: Anees W. , Gannon P.F. , Huggins V. , Pantin C.F.A. , Burge P.S. 
Published: April 2004

Serial peak expiratory flow records are recommended in the first-line investigation of suspected occupational asthma.The effects of sequentially reducing the numbers of working weeks, consecutive days at work and readings taken per day on diagnostic sensitivity and specificity were investigated, using good quality peak expiratory flow records from 81 workers with independently confirmed occupational asthma and 60 asthmatics without occupational exposure.Sensitivity was 81.8% for records of 4 weeks' duration and 70% for those of 2 weeks' duration (specificity 93.8 and 82.4% respectively). The sensitivity fell to 56.7% if there were only 2 consecutive workdays in each work period. Although best at 8 readings·day−1, sensitivity and specificity were acceptable with four daily readings (82.4 and 87%). The effect of defining a record as being of adequate quality if it was of ≥2.5 weeks' duration, with ≥4 readings·day−1and ≥3 consecutive workdays in each work period, was tested in records not used in the initial data reduction process. The sensitivity and specificity respectively of adequate records were 78.1 and 91.8versus63.6 and 83.3% for inadequate records.Peak expiratory flow records for the diagnosis of occupational asthma should be interpreted with caution if they do not satisfy the suggested minimum data quantity criteria.
Differential effects of emphysema on skeletal muscle fibre atrophy in hamsters
Authors: Mattson J.P. , Delp M.D. , Poole D.C. 
Published: April 2004

Patients afflicted with emphysema demonstrate altered peripheral skeletal muscle fibre composition and atrophy. It is unknown whether these alterations are general to all skeletal muscles independent of function, phenotype or oxidative capacity. Therefore, the purpose of this investigation was to determine whether emphysema induces alterations in muscle fibre composition or atrophy in respiratory and locomotory muscles with diverse fibre types and metabolic profiles.Fibre composition and cross-sectional area were measured in selected hindlimb muscles and diaphragm of hamsters following saline (control, n=7) or elastase (emphysema, n=15) instillation.Excised lung volume increased 145% with emphysema. Fibre composition was largely unaltered, with the exception of a 13% reduction in IIB fibres in the tibialis anterior muscle of emphysema animals. Type I fibre size was also mainly unaltered, except for a diminished cross-sectional area in plantaris muscle. However, fibre cross-sectional area of fast-twitch types IIA, IIX and/or IIB fibres was reduced in the caudal biceps femoris, vastus lateralis, tibialis anterior, gastrocnemius and plantaris muscles of emphysema animals. In contrast, there was a trend for emphysema to increase the cross-sectional area of type IIA fibres in the diaphragm.These data demonstrate that emphysema-induced atrophy primarily affects locomotory muscles, independent of phenotype or oxidative capacity.
Clarithromycin reduces the severity of bronchial hyperresponsiveness in patients with asthma
Authors: Kostadima E. , Tsiodras S. , Alexopoulos E.I. , Kaditis A.G. , Mavrou I. , Georgatou N. , Papamichalopoulos A. 
Published: April 2004

A randomised double-blind placebo-controlled study was designed to evaluate the effects of a semisynthetic macrolide antibiotic, clarithromycin, on bronchial hyperresponsiveness to methacholine in patients with a diagnosis of asthma.Adult asthma patients undergoing treatment with budesonide 400 µgb.i.d.and salbutamol 200 µgp.r.n.less than twice weekly were studied. Arm A (16 males/six females, aged 48±16 yrs) received clarithromycin 250 mgb.i.d.for 8 weeks, arm B (eight males/12 females, aged 42±12 yrs) clarithromycin 250 mgt.i.d.and arm C (six males/15 females, aged 41±16 yrs) placebo dextrose tablets. Bronchial hyperresponsiveness was quantified by measurement of the provocative dose of methacholine causing a 20% fall in forced expiratory volume in one second (PD20).Median (interquartile range) PD20in the three groups before and after treatment with clarithromycin were: arm A: 0.3 (0.1–1) and 1.3 (0.6–2) mg; arm B: 0.4 (0.1–0.9) and 2 (2–2) mg; and arm C: 0.4 (0.1–0.9) and 0.3 (0.1–0.6) mg, respectively. Serum free cortisol levels were determined and remained unchanged from baseline in the clarithromycin-treated patients.It is concluded that clarithromycin reduces the degree of bronchial hyperresponsiveness in patients with asthma.
Impact of preventing exacerbations on deterioration of health status in COPD
Authors: Spencer S. , Calverley P.M.A. , Burge P.S. , Jones P.W. 
Published: April 2004

Exacerbations of chronic obstuctive pulmonary disease (COPD) are associated with worse health status. The Inhaled Steroids in Obstructive Lung Disease in Europe (ISOLDE) study showed that treatment with fluticasone propionate (FP) reduced exacerbation frequency and the rate of deterioration in health status as compared with placebo. The present study analysed these data to test whether the effect of FP on health status was attributable to its effect on exacerbations.Rates of deterioration in St George's Respiratory Questionnaire (SGRQ) total score were obtained for 613 patients with moderate to severe COPD followed for a maximum of 3 yrs. Exacerbation rates were skewed and could not be normalised, therefore, patients were stratified into three exacerbation groups: none, infrequent (<1.65 exacerbations·yr−1) and frequent (>1.65 exacerbations·yr−1).There were 91 patients with no exacerbations, 285 with infrequent exacerbations and 235 with frequent exacerbations. Frequent exacerbations were independently associated with a worse baseline SGRQ score (p<0.0001) and a more rapid rate of deterioration in health status (p=0.0003). Exacerbation frequency and rate of decline in forced expiratory volume in one second were independently related to the rate of deterioration in SGRQ score.Statistical modelling showed the beneficial effect of fluticasone propionate on deterioration in health status to be largely due to its effect on exacerbation frequency.
Diabetic Nephropathy
Authors: Jones Stephen C. , Marshall Sally M. , Bilous Rudy W. 
Published: April 2004

AbstractDiabetic kindney disease affects up to one third of patients withtype 1 and type 2 diabetes and is anow the commonest single cause of end‐stage renal failure in the western world. The cumulative incidence of diabetic nephropathy continues to increase as type 2 diabetes becomes more prevalent. Managing increasing numbers of patients requiring renal replacement therapy is a major challenge for health services throughout the world. Diagnosis is usually made upon clinical grounds and is based on the detection of albuminuria. If the diagnosis is in doubt renal biopsy should be considered. The major clinical phases of diabetic kidney disease are microalbuminuria, proteniuria or overt nephropathy, progressive renal impairment, and end‐stagerenal failure. Not all patients progress to end‐stage renal afailure because of an associated excess cardiac mortality. Major risk factors for diabetic kidney disease are poor glycemic control and hypertension. Genetic factors also appear to play an important role in determining an individuals predisposition, but the gene(s) responsible have not yet been unequivocallly identified. Treatment is based upon primary prevention with good glycaemic control and treatment of hypertension. Secondary prevention with antihypertensive therapy, particularly with agents acting on the renin‐‐angiotensin system, can slow the rate of progression of diabetic nephropathy and delay the onset of end‐stage renal failure. Coexisting cardiovascular risk factors should also be aggressively managed. Patients with advanced diabetic kidney disease often have multiple problems that require the input of a large number of health care professionals.
Clinical and genetic heterogeneity in Desbuquois dysplasia
Authors: Faivre Laurence , Le Merrer Martine , Zerres Klaus , Hariz Mongi Ben , Scheffer Déborah , Young Ian D. , Maroteaux Pierre , Munnich Arnold , Cormier‐Daire Valérie 
Published: April 2004

AbstractDesbuquois dysplasia is a rare chondrodysplasia of autosomal recessive inheritance characterized by short stature, joint laxity, facial anomalies, a “Swedish key” appearance of the proximal femur, and advanced carpal and tarsal bone age. Patients with Desbuquois dysplasia can be divided in two groups, depending on whether hand changes include an extra ossification center distal to the second metacarpal and whether phalangeal dislocations are present or absent. We have recently reported linkage of a Desbuquois dysplasia gene to 17q25.3 in a group of patients with typical hand abnormalities. Here, we report on the exclusion of the 17q25.3 locus in three inbred Desbuquois families originated from Turkey, Asia, and Morocco without typical hand abnormalities. Microsatellite DNA markers from the 17q25.3 region were used at an average spacing of 2 cM, and the three affected individuals from families 1 to 3 were heterozygous for the 17q25.3 region. These results allow us to exclude this region as the locus in Desbuquois families with no hand anomalies and demonstrate genetic heterogeneity. Ongoing studies will hopefully lead to the identification of the responsible genes. © 2004 Wiley‐Liss, Inc.
Cardiomyopathy in Coffin–Lowry syndrome
Authors: Facher Jennifer J. , Regier Elizabeth J. , Jacobs Gretta H. , Siwik Ernest , Delaunoy Jean‐Pierre , Robin Nathaniel H. 
Published: April 2004

AbstractCoffin–Lowry syndrome (CLS) is a rare but well‐documented X‐linked disorder characterized by small size, developmental delay/mental retardation, and characteristic facial and skeletal findings in affected males. The phenotype in affected females is far more variable and can include developmental differences, obesity, and characteristic facial and skeletal differences. Cardiac anomalies are reported in less than 20% of affected males, with cardiomyopathy being one of the rare but reported complications of this disorder. However, cardiomyopathy is not well characterized in CLS. Here, we report on a 14‐year‐old boy with physical and developmental findings consistent with CLS who presented with a relatively sudden onset of signs of congestive heart failure due to a restrictive cardiomyopathy; an endomyocardial biopsy demonstrated non‐specific hypertrophic myocyte alterations consistent with cardiomyopathy. This is the first description of the histology and electron microscopy of cardiomyopathy in CLS. © 2004 Wiley‐Liss, Inc.
A new patient with pure trisomy 4p resulting from isochromosome formation and whole arm translocation
Authors: Zahed L. , Oreibi G. , El‐Amine H. , Obeid M. , Bitar F.F. 
Published: April 2004

AbstractShort arm isochromosome formation with translocation of the entire long arm of the same chromosome is an unusual constitutional abnormality that has been observed, to our knowledge, in 18 cases. Only one of these previously reported cases involved chromosome 4, resulting in pure trisomy 4p. Pure trisomy 4p has been reported in a number of cases, the majority of them due to familial chromosome rearrangements, and is associated with a distinct pattern of abnormal findings. We report here a second case of a de novo chromosome 4 whole arm translocation with short‐arm isochromosome formation, which we have delineated further by FISH studies. © 2004 Wiley‐Liss, Inc.
Surface properties of cationic ultraviolet‐curable coatings containing a siloxane structure
Authors: Sangermano M. , Bongiovanni R. , Malucelli G. , Priola A. , Pollicino A. , Recca A. , Jönsson S. 
Published: April 2004

AbstractA polysiloxane diglycidyl ether was used as a comonomer of epoxy resins to obtain coatings through the ultraviolet curing technique. Notwithstanding its very low concentration (<1 wt %), the siloxane monomer caused a change in the surface properties of the films. Selective surface stratification was evidenced by X‐ray photoelectron spectroscopy analysis, and an interesting surface modification was achieved without changing the bulk properties of the films or the rate of polymerization. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 584–589, 2004
Effect of static magnetic field on growth and sporulation of some plant pathogenic fungi
Authors: Nagy P. , Fischl G. 
Published: April 2004

AbstractGrowth and sporulation of phytopathogenic microscopic fungi were studied under a static magnetic field. The applied flux densities were 0.1, 0.5, and 1 mT. The magnetic field decreased the growth of colonies by 10% using this flux density region. At 0.1 mT flux density, the deviations are significant, P = .001, while in other cases the deviations generally are not significant. At the same time, the number of the developed conidia of Alternaria alternata and Curvularia inaequalis increased by 68–133%, but the number of Fusarium oxysporum conidia decreased by 79–83%. The deviations are generally significant at the P = .05 level. Bioelectromagnetics 25:316–318, 2004. © 2004 Wiley‐Liss, Inc.