bluuebunny/crossref_metadata_2025_split huggingface dataset:
In VitroBrucella suisInfection Prevents the Programmed Cell Death of Human Monocytic Cells
Authors: Gross Antoine , Terraza Annie , Ouahrani-Bettache Safia , Liautard Jean-Pierre , Dornand Jacques 
Published: May 2009

ABSTRACTDuring the complex interaction between an infectious agent and a host organism, the pathogen can interfere with the host cell's programmed death to its own benefit. Induction or prevention of host cell apoptosis appears to be a critical step for determining the infection outcome. Members of the gram-negative bacterial genusBrucellaare intracellular pathogens which preferentially invade monocytic cells and develop within these cells. We investigated the effect ofBrucella suisinfection on apoptosis of human monocytic phagocytes. The present study provides evidence thatBrucellainfection inhibited spontaneously occurring apoptosis in human monocytes. Prevention of monocyte apoptosis was not mediated byBrucellalipopolysaccharide and required bacterial survival within infected cells. Both invaded and noninvaded cells were protected, indicating that soluble mediators released during infection were involved in the phenomenon. Analysis ofBrucella-infected monocytes revealed specific overexpression of theA1gene, a member of thebcl-2family implicated in the survival of hematopoietic cells.Brucellainfection also rendered macrophage-like cells resistant to Fas ligand- or gamma interferon-induced apoptosis, suggesting thatBrucellainfection protected host cells from several cytotoxic processes occurring at different steps of the immune response. The present data clearly show thatBrucella suismodulated the monocyte/macrophage's apoptotic response to the advantage of the pathogen, thus preventing host cell elimination. This might represent a strategy forBrucelladevelopment in infected hosts.
Toxoplasma gondii
Infection Induces Gene Expression and Secretion of Interleukin 1 (IL-1), IL-6, Granulocyte-Macrophage Colony-Stimulating Factor, and Intercellular Adhesion Molecule 1 by Human Retinal Pigment Epithelial Cells
Authors: Nagineni Chandrasekharam N. , Detrick Barbara , Hooks John J. 
Published: May 2009

ABSTRACT

We have used human retinal pigment epithelial (HRPE) cultures to investigate the primary cellular responses of retinal resident cells to intracellular
Toxoplasma gondii
replication. At 4 days postinoculation, when all of the cells were infected, the secretion of interleukin 1β (IL-1β), IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF), and intercellular adhesion molecule 1 (ICAM-1) was augmented by 23-, 10-, 8-, and 5-fold, respectively, over the control. Northern and reverse transcriptase PCR analyses showed significant upregulation of steady-state levels of mRNA for IL-1β, IL-6, GM-CSF, and ICAM-1. The secretion of these molecules by HRPE cells may play a critical immunoregulatory role in the pathophysiological processes associated with
T. gondii
-induced retinochoroiditis.
Igh-6−/−(B-Cell-Deficient) Mice Fail To Mount Solid Acquired Resistance to Oral Challenge with VirulentSalmonella entericaSerovar Typhimurium and Show Impaired Th1 T-Cell Responses toSalmonellaAntigens
Authors: Mastroeni Pietro , Simmons C. , Fowler R. , Hormaeche C. E. , Dougan G. 
Published: May 2009

ABSTRACTIn the present study we evaluated the role of B cells in acquired immunity toSalmonellainfection by using gene-targeted B-cell-deficient innately susceptible mice on a C57BL/6 background (Igh-6−/−).Igh-6−/−mice immunized with a live, attenuatedaroA Salmonella entericaserovar Typhimurium vaccine strain showed impaired long-term acquired resistance against the virulent serovar Typhimurium strain C5.Igh-6−/−mice were able to control a primary infection and to clear the inoculum from the reticuloendothelial system. However,Igh-6−/−mice, unlikeIgh-6+/+C57BL/6 controls, did not survive an oral challenge with strain C5 at 4 months after vaccination. Transfer of immune serum did not restore resistance inIgh-6−/−mice. Total splenocytes and purified CD4+T cells obtained fromIgh-6−/−mice 4 months after vaccination showed reduced ability to release Th1-type cytokines (interleukin 2 and gamma interferon) upon in vitro restimulation with serovar Typhimurium soluble cell extracts compared to cells obtained fromIgh-6+/+C57BL/6 control mice. Therefore, the impaired resistance to oral challenge with virulent serovar Typhimurium observed in B-cell-deficient mice, which cannot be restored by passive transfer ofSalmonella-immune serum, may be in part due to a reduced serovar Typhimurium-specific T-cell response following primary immunization.
Characterization of PaxA and Its Operon: a Cohemolytic RTX Toxin Determinant from Pathogenic
Pasteurella aerogenes
Authors: Kuhnert Peter , Heyberger-Meyer Bénédicte , Nicolet Jacques , Frey Joachim 
Published: May 2009

ABSTRACT

Pasteurella aerogenes
is known as a commensal bacterium or as an opportunistic pathogen, as well as a primary pathogen found to be involved in abortion cases of humans, swine, and other mammals. Using broad-range DNA probes for bacterial RTX toxin genes, we cloned and subsequently sequenced a new operon named
paxCABD
encoding the RTX toxin PaxA in
P. aerogenes
. The
pax
operon is organized analogous to the classical RTX operons containing the activator gene
paxC
upstream of the structural toxin gene
paxA
, which is followed by the secretion protein genes
paxB
and
paxD
. The highest sequence similarity of
paxA
with known RTX toxin genes is found with
apxIIIA
(82%). PaxA is structurally similar to ApxIIIA and also shows functional analogy to ApxIIIA, since it shows cohemolytic activity with the sphingomyelinase of
Staphylococcus aureus
, known as the CAMP effect, but is devoid of direct hemolytic activity. In addition, it shows to some extent immunological cross-reactions with ApxIIIA.
P. aerogenes
isolated from various specimens showed that the
pax
operon was present in about one-third of the strains. All of the
pax
-positive strains were specifically related to swine abortion cases or septicemia of newborn piglets. These strains were also shown to produce the PaxA toxin as determined by the CAMP phenomenon, whereas none of the
pax
-negative strains did. This indicated that the PaxA toxin is involved in the pathogenic potential of
P. aerogenes
. The examined
P. aerogenes
isolates were phylogenetically analyzed by 16S rRNA gene (
rrs
) sequencing in order to confirm their species. Only a small heterogeneity (<0.5%) was observed between the
rrs
genes of the strains originating from geographically distant farms and isolated at different times.
Typing of Intimin Genes in Human and Animal Enterohemorrhagic and EnteropathogenicEscherichia coli: Characterization of a New Intimin Variant
Authors: Oswald E. , Schmidt H. , Morabito S. , Karch H. , Marchès O. , Caprioli A. 
Published: May 2009

ABSTRACTEnteropathogenicEscherichia coli(EPEC) and enterohemorrhagicE. coli(EHEC) produce the characteristic “attaching and effacing” (A/E) lesion of the brush border. Intimin, an outer membrane protein encoded byeae, is responsible for the tight association of both pathogens with the host cell. Severaleaehave been cloned from different EPEC and EHEC strains isolated from humans and animals. These sequences are conserved in the N-terminal region but highly variable in the last C-terminal 280 amino acids (aa), where the cell binding activity is localized. Based on these considerations, we developed a panel of specific primers to investigate theeaeheterogeneity of the variable 3′ region by using PCR amplification. We then investigated the distribution of the known intimin types in a large collection of EPEC and EHEC strains isolated from humans and different animal species. The existence of a yet-unknown family of intimin was suspected because several EHEC strains, isolated from human and cattle, did not react with any of the specific primer pairs, although these strains wereeaepositive when primers amplifying the conserved 5′ end were used. We then cloned and sequenced theeaepresent in one of these strains (EHEC of serotype O103:H2) and subsequently designed a PCR primer that recognizes in a specific manner the variable 3′ region of this new intimin type. This intimin, referred to as “ɛ,” was present in human and bovine EHEC strains of serogroups O8, O11, O45, O103, O121, and O165. Intimin ɛ is the largest intimin cloned to date (948 aa) and shares the greatest overall sequence identity with intimin β, although analysis of the last C-terminal 280 aa suggests a greater similarity with intimins α and γ.
Can we rely on one laboratory test in detection of extended-spectrum β-lactamases among Enterobacteriaceae? An evaluation of the Vitek 2 system and comparison with four other detection methods in Kuwait: Table 1
Authors: Dashti A A , Jadaon M M , Habeeb F M 
Published: May 2009

Background and Aims:Clinical hospitals need to correctly identify extended spectrum β-lactamase (ESBL)-producing bacteria in infected patients to correctly treat the patient and avoid spreading antibiotic resistance. Kuwaiti hospitals use one laboratory test for detecting ESBL bacteria. This study evaluated whether that was sufficient to detect ESBL bacteria, and compared the Vitek system with other detection systems.Methods:(Klebsiella pneumoniae,Escherichia coli,K oxytocaandEnterobacter cloacae) were collected from five different Kuwaiti main hospitals, all of which were flagged as ESBL-positive by the Vitek 2 system. The isolates were retested by the Vitek 2 system, and were also tested by double disc diffusion (DDD), the disc approximation test, the E-test and the MicroScan system for the detection of ESBLs.Results:Retesting with the Vitek system revealed 100% compatibility with the results of the source hospitals. The MicroScan system, DDD, disc approximation test and E-test could detect ESBL in 199, 192, 178 and 205 isolates, respectively.Conclusions:Technically, the MicroScan and Vitek 2 systems were the least demanding method to detect ESBL as it is an integral part of the routine susceptibility test card. E-test strips were reliable but the most expensive of all techniques used. The DDD test and disc approximation, while relatively inexpensive, were technically subjective. The Vitek system may be very suitable in clinical laboratories, but would be better if accompanied with another test for detection of ESBL bacteria.
Acute arsenic self-poisoning for suicidal purpose in a dentist: a case report
Authors: Yilmaz Y , Armagan E , Olmez OF , Esen M , Alkis N , Dolar E 
Published: May 2009

Arsenic is a classical poison that has been historically used since ancient times for homicidal purposes. More recently, episodes of deliberate or unintentional arsenic self-poisoning have been increasingly reported. We describe here a case of a 77-year old male patient with a history of major depression, who attempted suicide by ingestion of 4 g of arsenic trioxide. The man, a dentist by profession, used arsenic preparations for pulp devitalization. The patient was admitted to our hospital 5 h after arsenic ingestion with nausea and vomiting. Plain radiograph of the abdomen showed radio-opaque material in the stomach and small intestine. Nasogastric lavage, activated charcoal, and chelators were used to remove arsenic. On day 3, endoscopy disclosed the presence of gastritis and superficial ulcers. The patient developed significant anemia (Hb: 8.7 g/dL on day 7) without significant signs of hemolysis. He gradually recovered from anemia within 5 months. The patient did not suffer any adverse outcome in spite of having ingesting 4 g of arsenic, approximately 20 times the lethal dose.
Expression of AS3MT alters transcriptional profiles in human urothelial cells exposed to arsenite
Authors: Hester SD , Drobná Z , Andrews DMK , Liu J , Waalkes MP , Thomas DJ , Stýblo M 
Published: May 2009

Inorganic arsenic (iAs) is an environmental toxicant and human carcinogen. The enzymatic methylation of iAs that is catalyzed by arsenic (+3 oxidation state)-methyltransferase (AS3MT) generates reactive methylated intermediates that contribute to the toxic and carcinogenic effects of iAs. We have shown that clonal human urothelial cells (UROtsa/F35) that express rat AS3MT and methylate iAs are more susceptible to acute toxicity of arsenite (iAsIII) than parental UROtsa cells that do not express AS3MT and do not methylate iAs. The current work examines transcriptional changes associated with AS3MT expression and identifies specific categories of genes expressed in UROtsa and UROtsa/F35 cells in response to a 24-h exposure to 1 or 50 μM iAsIII. Here, the expression of 21,073 genes was assessed using Agilent Human 1A(V2) arrays. Venn analysis showed marked concentration-dependent differences between gene expression patterns in UROtsa and UROTsa/F35 cells exposed to iAsIII. Among 134 genes altered by exposure to subtoxic 1 μM iAsIII, only 14 were shared by both cell lines. Exposure to cytotoxic 50 μM iAsIII uniquely altered 1389 genes in UROtsa/F35 and 649 genes in UROtsa cells; 5033 altered genes were associated with the chemical alone. In UROtsa, but not UROtsa/F35 cells exposure to 1 μM iAsIII altered expression of genes associated with cell adhesion. In contrast, expression of genes involved in cell cycle regulation was significantly altered in UROtsa/F35 cells at this exposure level. At 50 μM iAsIII, pathways regulating cell cycle, cell death, transcription, and metabolism were affected in both cell lines. However, only Urotsa/F35 cells showed numerous G-protein and kinase pathway alterations as well as alterations in pathways involved in cell growth and differentiation. These data link the AS3MT-catalyzed methylation of iAs to specific genomic responses in human cells exposed to iAsIII. Further analysis of these responses will help to characterize the role of AS3MT-catalyzed methylation in modulation of iAsIII toxicity.
Hospital-at-home care for exacerbations of chronic obstructive pulmonary disease: an observational cohort study of patients managed in hospital or by nurse practitioners in the community
Authors: Ansari K , Shamssain M , Farrow M , Keaney NP 
Published: May 2009

The Urgent Care Team (UCT) in Sunderland (pop. 293,000) is a unique nurse practitioner service operating a hospital at home 24/7/365 to deal promptly with patients suffering an exacerbation of their COPD (AECOPD). Treatment is according to patient group directions utilising nebulised bronchodilators, doxycycline and prednisolone. To compare the health status and pathophysiology during and two months after an AECOPD in 60 UCT patients (31 male) and 30 hospital-managed patients (16 male). The St. Georges Respiratory Questionnaire (SGRQ), Mahler Baseline Dyspnoea Index (BDI) and MRC dyspnoea score recorded health status. Spirometry, BMI and grip strength were also measured. All patients were reviewed 2–3 months after the AECOPD. Changes from BDI were measured using the Transitional Dyspnoea Index (TDI). Mean FEV1% predicted was 47%. In the recovery phase the two groups were comparable for all variables. But during their AECOPD hospitalised patients had a significantly lower BDI ( P < 0.05) and an oxygen saturation ranging from 84 to 93% compared with 87–96% for UCT patients. Paired t-tests indicated that on recovery SGRQ activity domain and TDI measures improved in both groups. No deaths occurred during these AECOPDs. A hospital-at-home scheme for AECOPDs can deal with patients who have severe COPD safely. The Mahler TDI appears to be a sensitive index of improvement after an AECOPD.
Circulating matrix metalloproteinase-9 and osteoporosis in patients with chronic obstructive pulmonary disease
Authors: Bolton CE , Stone MD , Edwards PH , Duckers JM , Evans WD , Shale DJ 
Published: May 2009

Matrix metalloproteinase-9 (MMP-9) has been implicated in airways injury in chronic obstructive pulmonary disease (COPD). Osteoporosis is common in patients with COPD, and MMP-9 is an indicator of activated osteoclasts. We hypothesized that circulating MMP-9 would be related to bone mineral density (BMD) in COPD. We explored the relationship between MMP-9, tissue inhibitors of metalloproteinases (TIMP)-1 and -2, and BMD status in patients with COPD. A total of 70 clinically stable patients with confirmed COPD and 39 control subjects underwent spirometry, dual-energy x-ray absorptiometry to determine BMD, and venous sampling for measurement of cytokines and MMP-9 and TIMP-1 and -2. In patients, circulating MMP-9 was increased: mean (SD) 38.5 (2.2) compared with control subjects 20.1 (2.0) ng/mL, P < 0.001, whereas TIMP-1 and -2 were not different. In the patients, MMP-9 was greater in those with osteoporosis, compared with those with osteopenia, no bone disease or control subjects, and patients with osteopenia had greater MMP-9 than control subjects. The adjusted receiver operating characteristics curve area for MMP-9 detecting osteoporosis was 0.86. Patients had elevated systemic inflammatory mediators compared with control subjects, but these were unrelated to bone status. Increased circulating MMP-9 in patients with COPD was related to the presence of osteoporosis and not to lung function. MMP-9 may be a biomarker of increased bone resorption.
Pelvic Fractures in Professional Cyclists: A Report of 3 Cases
Authors: Cerynik Douglas L. , Roshon Michael , Abzug Joshua M. , Harding Susan P. , Tom James A. 
Published: May 2009

Background: Professional riders demonstrate increased risk factors for such injuries including both extensive time on the bike in addition to a possible underlying osteopenia secondary to the nonimpact nature of the sport. Hypothesis: Nonoperative management of stable, nondisplaced pelvic fractures in professional cyclists offers excellent results. Study Design: Case series. Methods: Three cases of professional cyclists with pelvic fractures were reviewed. Results: All 3 cyclists were able to return to professional competition and remain symptom free. Conclusion: Accurate early diagnosis of pelvic fractures, with the aid of computed tomography, is crucial. Early non-weightbearing with a progression to weightbearing as tolerated and early return to stationary training are appropriate. Accurate diagnosis and careful nonoperative management of stable, nondisplaced pelvic fractures in professional cyclists offers excellent results. Clinical Relevance: Accurate diagnosis of pelvic fractures in high-demand athletes with few complaints and no obvious findings on plain film radiographs. Control of weightbearing and competitive status to prevent injury progression. Gauged return to competition at professional level.
Suspected Mechanisms in the Cause of Overuse Running Injuries: A Clinical Review
Authors: Ferber Reed , Hreljac Alan , Kendall Karen D 
Published: May 2009

Context: Various epidemiological studies have estimated that up to 70% of runners sustain an overuse running injury each year. Although few overuse running injuries have an established cause, more than 80% of running-related injuries occur at or below the knee, which suggests that some common mechanisms may be at work. The question then becomes, are there common mechanisms related to overuse running injuries? Evidence Acquisition: Research studies were identified via the following electronic databases: MEDLINE, EMBASE PsycInfo, and CINAHL (1980–July 2008). Inclusion was based on evaluation of risk factors for overuse running injuries. Results: A majority of the risk factors that have been researched over the past few years can be generally categorized into 2 groups: atypical foot pronation mechanics and inadequate hip muscle stabilization. Conclusion: Based on the review of literature, there is no definitive link between atypical foot mechanics and running injury mechanisms. The lack of normative data and a definition of typical foot structure has hampered progress. In contrast, a large and growing body of literature suggests that weakness of hip-stabilizing muscles leads to atypical lower extremity mechanics and increased forces within the lower extremity while running.
Return to Basketball and Soccer After Anterior Cruciate Ligament Reconstruction in Competitive School-Aged Athletes
Authors: Shelbourne K. Donald , Sullivan A. Nichole , Bohard Katie , Gray Tinker , Urch Scott E. 
Published: May 2009

Background: Little is known about the return to sports after anterior cruciate ligament reconstruction and whether sex differences exist regarding the level and timing at which athletes return. Hypotheses: Compared to school-aged girls, boys return to full sports earlier and at a higher frequency after surgery (1). Athletes who return to sports earlier will not have a higher incidence of subsequent injury to either knee after surgery (2). Study Design: Cohort. Methods: The patient population comprised 413 consecutive school-aged athletes who were injured while competing in basketball or soccer. Patients were enrolled prospectively, and activity levels were obtained through follow-up visits, surveys, phone calls, and e-mail. Results: Follow-up was obtained for 402 patients (basketball: 58 boys, 242 girls; soccer: 25 boys, 77 girls). Eighty-seven percent of girls and boys returned to high school basketball after surgery: the mean time to return to full participation in basketball was 5.2 ± 2.1 months for girls and 5.3 ± 2.2 months for boys ( P = .92). Similarly, 93% of girls and 80% of boys returned to compete in high school soccer after surgery ( P = .13); the mean time to return to full participation in soccer was 5.1 ± 1.9 months for girls and 5.1 ± 2.0 for boys ( P = 1.00). About 20% of athletes went on to compete in their sport in college. The time of return to sports was not a statistically significant factor for the incidence of subsequent anterior cruciate ligament injury. Conclusion: Of 402 athletes competing in basketball and soccer, women and men returned at the same rate and same level of sport after surgery. Athletes who returned to sports at earlier times after surgery did not have a higher incidence of subsequent anterior cruciate ligament injury than patients who returned at later times.
KLRG1 signaling induces defective Akt (ser473) phosphorylation and proliferative dysfunction of highly differentiated CD8+ T cells
Authors: Henson Sian M. , Franzese Ornella , Macaulay Richard , Libri Valentina , Azevedo Rita I. , Kiani-Alikhan Sorena , Plunkett Fiona J. , Masters Joanne E. , Jackson Sarah , Griffiths Stephen J. , Pircher Hans-Peter , Soares Maria V. D. , Akbar Arne N. 
Published: May 2009

AbstractHighly differentiated CD8+CD28−CD27− T cells have short telomeres, defective telomerase activity, and reduced capacity for proliferation, indicating that they are close to replicative senescence. In addition, these cells express increased levels of the senescence-associated inhibitory receptor KLRG1 and have poor capacity for IL-2 synthesis and defective Akt (ser473) phosphorylation after activation. It is not known whether signaling via KLRG1 contributes to any of the attenuated differentiation-related functional changes in CD8+ T cells. To address this, we blocked KLRG1 signaling during T-cell receptor activation using antibodies against its major ligand, E-cadherin. This resulted in a significant enhancement of Akt (ser473) phosphorylation and T-cell receptor–induced proliferative activity of CD8+CD28−CD27− T cells. Furthermore, the increase of proliferation was directly linked to the Akt-mediated induction of cyclin D and E and reduction in the cyclin inhibitor p27 expression. In contrast, the reduced telomerase activity in highly differentiated CD8+CD28−CD27− T cells was not altered by KLRG1 blockade, indicating the involvement of other mechanisms. This is the first demonstration of a functional role for KLRG1 in primary human CD8+ T cells and highlights that certain functional defects that arise during progressive T-cell differentiation toward replicative senescence are maintained actively by inhibitory receptor signaling.