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Publication
Journal: International Journal of Immunopathology and Pharmacology
March/6/2006
Abstract
Pseudomonas aeruginosa and Burkholderia cenocepacia are predominant opportunistic pathogens in cystic fibrosis (CF) patients. In healthy humans the lower respiratory tract as well as all mucosa, contains a very low free iron concentration (10(-18) M), while in CF patients sputum iron concentration is very high, showing a median value of 63x10(-6) M. Accumulation of catalytic reactive iron heavily contributes to subsequent clinical complications in the lung disorders by the production of reactive oxygen species and increases bacterial growth and virulence. The data reported in this study indicate that low iron concentration (Fe3+ 1 microM)induced free-living forms and motility both in P. aeruginosa and B. cenocepacia, while high iron concentrations (Fe3+ 10 and 100 microM) stimulated aggregation and biofilm formation already in the fluid phases, so demonstrating that aggregation and biofilm formation are positively iron-modulated in these bacteria. Moreover, the different morphological forms (free-living, aggregates and biofilm) showed different capabilities of adhering and invading the bronchial cell line A549. P. aeruginosa PAO1 aggregates, and mostly biofilm, exerted the highest adhesion efficiency, while B. cenocepacia PV1 aggregates or biofilm the lowest. A significant reduction in invasion efficiency by P. aeruginosa biofilm and a significant increase in cell internalization by B. cenocepacia biofilm has been reported. Therefore, the iron availability is an important signal to which P. aeruginosa and B. cenocepacia counteract by leaving the motile free-living forms and entering into a new lifestyle, i.e. biofilm. These data could contribute to explain that the iron-overload of the sputum of CF patients, inducing nonmotile forms, aggregates and biofilm, may facilitate penetration of host epithelial barriers contributing to the establishment of infection, colonization, persistence and systemic spread of these opportunistic pathogens.
Publication
Journal: Glycobiology
October/11/2010
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that affects immunocompromised individuals and causes life-threatening infections in cystic fibrosis (CF) patients. Colonization of CF lung by P. aeruginosa involves a biofilm mode of growth, which is promoted by the production of exopolysaccharides. These polymers are essential components of the extracellular biofilm matrix. P. aeruginosa possesses several clusters contributing to the formation of the matrix, including the pel or psl genes. In the present study, we identified anionic cyclic glucans produced by P. aeruginosa, which are associated with the matrix of strains PAKDeltaretS and PA14. Their structure has been elucidated using chemical analysis, 1- and 2D nuclear magnetic resonance techniques and mass spectrometry. They belong to a family of cyclic beta-(1-->3)-linked glucans of 12-16 glucose residues with 30-50% of glucose units substituted by 1-phosphoglycerol at O-6. These glucans were also recovered in pel mutant strains, which indicated that their biosynthesis was pel independent. In an effort to understand the biogenesis of these glucans, we analyzed the matrix components of a previously characterized P. aeruginosa PA14 mutant, the PA14::ndvB mutant strain. The ndvB gene was predicted to be involved in the synthesis of perisplasmic glucans, capable of physically interacting with aminoglycoside antibiotics. We revealed that the highly glycerol-phosphorylated beta-(1-->3)-glucans are lacking in the ndvB mutant, and we showed that these glucans are capable of direct binding with the aminoglycoside antibiotic kanamycin. This observation fills a gap in our understanding of the relationship between biofilm, cyclic glucans and high-level antibiotic resistance.
Publication
Journal: Journal of Heart and Lung Transplantation
March/15/2011
Abstract
BACKGROUND
Pre-operative infection with organisms from the Burkholderia cepacia complex (BCC), particularly B cenocepacia, has been linked with a poorer prognosis after transplantation compared to patients with cystic fibrosis (CF) without this infection. Therefore, many transplant centers do not list these patients for transplantation.
METHODS
We report the early and long-term results of a cohort of lung transplant recipients with CF and pre-operative BCC infection. Patients with pre-transplantation BCC infection were identified by case-note review. BCC species status was assigned by polymerase chain reaction (PCR)-based techniques. Survival rates were compared to recipients with CF without BCC infection. Survival rates in BCC subgroups were also compared, and then further analyzed pre- and post-2001, when a new immunosuppressive and antibiotic regime was introduced for such patients.
RESULTS
Two hundred sixteen patients with CF underwent lung transplantation and 22 had confirmed pre-operative BCC infection, with 12 of these being B cenocepacia. Nine B cenocepacia-infected recipients died within the first year, and in 8 BCC sepsis was considered to be the cause of death. Despite instituting a tailored peri-operative immunosuppressive and microbiologic care approach for such patients, post-transplantation BCC septic deaths occurred frequently in those with pre-transplantation B cenocepacia infection. In contrast, recipients infected with other BCC species had significantly better outcomes, with post-transplantation survival comparable to other recipients with CF.
CONCLUSIONS
Mortality in patients with B cenocepacia infection was unacceptably high and has led to our center no longer accepting patients with this condition onto the lung transplant waiting list. Long-term survival in the non-B cenocepacia BCC group was excellent, without high rates of acute rejection or bronchiolitis obliterans syndrome (BOS) longer term, and these patients continue to be considered for lung transplantation.
Publication
Journal: Emerging Infectious Diseases
August/31/1998
Abstract
In the past 2 decades, Burkholderia cepacia has emerged as a human pathogen causing numerous outbreaks, particularly among cystic fibrosis (CF) patients. One highly transmissible strain has spread across North America and Britain, and another between hospitalized CF and non-CF patients. Meanwhile, the organism has been developed as a biopesticide for protecting crops against fungal diseases and has potential as a bioremediation agent for breaking down recalcitrant herbicides and pesticides. However, B. cepacia is inherently resistant to multiple antibiotics; selection of strains "safe" for environmental application is not at present possible phenotypically or genotypically; molecular epidemiology and phylogenetic studies demonstrate that highly transmissible strains emerge randomly; and the organism has a capacity for rapid mutation and adaptation (facilitated by numerous insertion sequences), and a large, complex genome divided into separate chromosomes. Therefore, the widespread agricultural use of B. cepacia should be approached with caution.
Publication
Journal: Journal of Clinical Microbiology
February/13/2002
Abstract
The recently described genus Pandoraea contains five named species (Pandoraea apista, Pandoraea pulmonicola, Pandoraea pnomenusa, Pandoraea sputorum, and Pandoraea norimbergensis) and four unnamed genomospecies. Pandoraea spp. have mainly been recovered from the respiratory tracts of cystic fibrosis (CF) patients. Accurate genus- and species-level identification by routine clinical microbiology methods is difficult, and differentiation from Burkholderia cepacia complex organisms may be especially problematic. This can have important consequences for the management of CF patients. On the basis of 16S ribosomal DNA sequences, PCR assays for the identification of Pandoraea spp. were developed. A first PCR assay was developed for the identification of Pandoraea isolates to the genus level. PCR assays for the identification of P. apista and P. pulmonicola as a group, P. pnomenusa, P. sputorum, and P. norimbergensis were also developed. All five assays were evaluated with a panel of 123 bacterial isolates that included 69 Pandoraea sp. strains, 24 B. cepacia complex strains, 6 Burkholderia gladioli strains, 9 Ralstonia sp. strains, 5 Alcaligenes xylosoxidans strains, 5 Stenotrophomonas maltophilia strains, and 5 Pseudomonas aeruginosa strains. The use of these PCR assays facilitates the identification of Pandoraea spp. and avoids the misidentification of a Pandoraea sp. as a B. cepacia complex isolate.
Publication
Journal: Journal of Antimicrobial Chemotherapy
October/23/2012
Abstract
OBJECTIVE
Triazole resistance in Aspergillus fumigatus due to a single azole resistance mechanism (TR/L98H) is increasingly reported in European countries. Data from patients with cystic fibrosis (CF) are limited. Our study aimed to investigate the prevalence and molecular mechanisms of azole resistance in A. fumigatus in a cohort of patients with CF.
METHODS
Eighty-five A. fumigatus isolates from 50 CF patients, collected between January 2010 and April 2011, were retrospectively analysed for azole resistance using agar plates containing 4 mg/L itraconazole. MICs of itraconazole, voriconazole and posaconazole were determined according to EUCAST methodology for each isolate able to grow on this medium. Species identification was performed by sequencing of the β-tubulin gene. Sequencing analysis of the cyp51A gene and its promoter region was conducted.
RESULTS
Nine isolates (four patients, 8% prevalence) were able to grow on itraconazole-containing agar plates. Itraconazole resistance was confirmed by EUCAST methodology (MICs >2 mg/L). All isolates had mutations in the cyp51A gene at residues previously involved in azole resistance: L98H (n = 5), M220T (n = 4) and G54R (n = 1). One patient had three genetically distinct azole-resistant isolates identified during the study. The isolates with L98H that were recovered from three patients (6% prevalence) also had the 34 bp tandem repeat in the promoter region of cyp51A (TR/L98H) and displayed multiazole resistance.
CONCLUSIONS
We report an 8% prevalence of itraconazole resistance in CF patients in our centre, mostly driven by TR/L98H (6%). Our data confirm that TR/L98H occurs in France and can be highly prevalent in CF patients.
Publication
Journal: Applied and Environmental Microbiology
March/20/1997
Abstract
The physicochemical interaction of pediocin PA-1 with target membranes was characterized using lipid vesicles made from the total lipids extracted from Listeria monocytogenes. Pediocin PA-1 caused the time- and concentration-dependent release of entrapped carboxyfluorescein (CF) from the vesicles. The pediocin-induced CF efflux rates were higher under acidic conditions than under neutral and alkaline conditions and were dependent on both pediocin and lipid concentrations. A binding isotherm constructed on the basis of the Langmuir isotherm gave an apparent binding constant of 1.4 x 10(7) M-1 at pH 6.0. The imposition of a transmembrane potential (inside negative) increased the CF efflux rate by 88%. Pediocin PA-1 also permeablized synthetic vesicles composed only of phosphatidylcholine. Sequence alignments and secondary-structure predictions for the N terminus of pediocin PA-1 and other class IIa bacteriocins predicted that pediocin PA-1 contained two beta-sheets maintained in a hairpin conformation stabilized by a disulfide bridge. The structural model also revealed patches of positively charged residues, consistent with the argument that electrostatic interactions play an important role in the binding of pediocin PA-1 to the lipid vesicles. This study demonstrates that pediocin PA-1 can function in the absence of a protein receptor and provides a structural model consistent with these results.
Publication
Journal: Autoimmunity Reviews
June/11/2018
Abstract
Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a frequent and severe chronic disease drastically impairing life quality. The underlying pathomechanism is incompletely understood yet but there is convincing evidence that in at least a subset of patients ME/CFS has an autoimmune etiology. In this review, we will discuss current autoimmune aspects for ME/CFS. Immune dysregulation in ME/CFS has been frequently described including changes in cytokine profiles and immunoglobulin levels, T- and B-cell phenotype and a decrease of natural killer cell cytotoxicity. Moreover, autoantibodies against various antigens including neurotransmitter receptors have been recently identified in ME/CFS individuals by several groups. Consistently, clinical trials from Norway have shown that B-cell depletion with rituximab results in clinical benefits in about half of ME/CFS patients. Furthermore, recent studies have provided evidence for severe metabolic disturbances presumably mediated by serum autoantibodies in ME/CFS. Therefore, further efforts are required to delineate the role of autoantibodies in the onset and pathomechanisms of ME/CFS in order to better understand and properly treat this disease.
Publication
Journal: Human Genetics
November/20/1990
Abstract
In this collaborative European study, a total of 4871 cystic fibrosis (CF) chromosomes and 3539 normal chromosomes have been characterized for the haplotypes defined by the 2 extragenic polymorphic sequences revealed by XV2c and KM19. The association between one of these haplotypes (B haplotype) and the most frequent CF mutation, delta F508, suggests for the latter a single origin and a subsequent diffusion according to a South East-North West gradient. The linkage disequilibrium data between CF and the B haplotype in different European populations are compatible with a relatively more recent appearance of the mutation in Northern Europe whereas in Southern Europe a longer history of the same mutation would have allowed time for recombination with other haplotypes. This model is also compatible with a selective advantage of carriers but does not account for (1) the excess of B haplotypes observed among both normal and non-delta F508 CF chromosomes; (2) the correlation between the B haplotype and the severity of the phenotypic effect caused by CF mutations, as measured by pancreatic insufficiency and meconium ileus.
Publication
Journal: Seminars in Respiratory and Critical Care Medicine
August/6/2007
Abstract
People with cystic fibrosis (CF) have chronic airway infection and frequent exposure to antibiotics, which often leads to the emergence of resistant organisms. In addition to the development of multiresistance in common CF pathogens such as Pseudomonas aeruginosa, several newer, inherently resistant gram-negative species are becoming more common, including Burkholderia cepacia complex, Stenotrophomonas maltophilia, Achromobacter (Alcaligenes) xylosoxidans, certain Ralstonia species, and those within the new genus Pandoraea. Many of these are closely related and have similar phenotypes, making accurate laboratory identification challenging. Although their role in contributing to pulmonary disease in CF is not clear, some, such as those of the B. cepacia complex, are clearly linked to an adverse prognosis, and both treatment and infection control issues can pose a real challenge.
Publication
Journal: Plant Cell
February/18/2017
Abstract
The Cf-9 gene encodes an extracytoplasmic leucine-rich repeat protein that confers resistance in tomato to races of the fungus Cladosporium fulvum that express the corresponding avirulence gene Avr 9. We investigated whether the genomic Cf-9 gene functions in potato and tobacco. Transgenic tobacco and potato plants carrying Cf-9 exhibit a rapid hypersensitive cell death response (HR) to Avr 9 peptide injection. Cf 9 tobacco plants were reciprocally crossed to Avr 9-producing tobacco. A developmentally regulated seedling lethal phenotype occurred in F1 progeny when CfCfCf 9 tobacco leaves revealed that (1) most mesophyll cells died within 3 hr (compared with 12 to 16 hr in tomato); (2) the macroscopic HR was visible at an Avr 9 titer five times lower than that which caused visible symptoms in tomato; (3) the HR invariably extended into noninjected panels of the tobacco leaf; (4) no HR occurred in leaves of young tobacco plants; (5) in older plants, the HR was dramatically enhanced by sequential Avr 9 challenges; and (6) coexpression of a salicylate hydroxylase transgene (nahG) from Pseudomonas putida reduced the severity of the macroscopic leaf HR and also restored germination to Cf 9 x 35S:Avr 9 F1 seedlings. Simultaneous introduction of Cf-9 homologs (Hcr 9-9 genes A and B or D) along with the native Cf-9 gene did not alter the responses that were specifically induced by Avr 9. Various ways to use the Cf-9-Avr 9 gene combination to engineer broad-spectrum disease resistance in several solanaceous species are discussed.
Publication
Journal: Hypertension
July/24/2014
Abstract
Angiotensin II induces cardiovascular injury, in part, by activating inflammatory response; however, the initial factors that trigger the inflammatory cascade remain unclear. Microarray analysis of cardiac tissue exposed to systemic angiotensin II infusion revealed that extracellular heterodimeric proteins S100a8/a9 were highly upregulated. The increase in S100a8/a9 mRNA of CD11b(+)Gr1(+) neutrophils isolated from both the peripheral blood and heart was highest on day 1 of angiotensin II infusion and decreased to baseline at day 7. Immunostaining showed that S100a8/a9 was primarily present in infiltrating CD11b(+)Gr1(+) neutrophils in the heart. The receptor for advanced glycation end products, an S100a8/a9 receptor, was expressed in cardiac fibroblasts (CFs). Microarray analysis and Bio-Plex protein array showed that treatment of CFs with recombinant S100a8/a9 activated multiple chemokine and cytokines released. Luciferase reporter assay indicated S100a8/a9-activated nuclear factor-κ B pathway in CFs. Consequently, recombinant S100a8/a9-treated CFs promoted migration of monocytes and CFs, whereas neutralizing S100a9 antibody blocked S100a9 or receptor for advanced glycation end products-suppressed cellular migration. Finally, administration of a neutralizing S100a9 antibody prevented angiotensin II infusion-induced nuclear factor-κ B activation, inflammatory cell infiltration, cytokine production, subsequent perivascular and interstitial fibrosis, and hypertrophy in heart. Our findings identify neutrophil-produced S100a8/a9 as an initial proinflammatory factor needed to trigger inflammation and cardiac injury during acute hypertension.
Publication
Journal: Cellular Microbiology
February/10/2008
Abstract
In cystic fibrosis (CF), infection with Burkholderia cepacia complex (Bcc) strains may cause long-term asymptomatic airway colonization, or severe lung infection leading to rapid pulmonary decline. To assess the virulence of Bcc strains, we established a lung infection model in mice with a null allele of the gene involved in X-linked chronic granulomatous disease (CGD). CGD mice, challenged intratracheally with 10(3) cells of the epidemic Burkholderia cenocepacia strain J2315, died within 3 days from sepsis after bacteria had multiplied to 3.3 x 10(8) cells. Infected mice developed neutrophil-dominated lung abscesses. Other B. cenocepacia strains and a B. cepacia strain were less virulent and one B. multivorans and one B. vietnamensis CF isolate were both avirulent. Bcc mutants, defective in exopolysaccharide synthesis or quorum sensing revealed diminished or no abscess formation and mortality. Immunofluorescence staining of Bcc-infected murine and CF lung tissues revealed colocalization of Bcc and neutrophils, suggesting Bcc persistence within neutrophils in CGD and CF. In vitro, Bcc cells were rapidly killed during aerobic neutrophil phagocytosis; however, the pathogens survived in neutrophils with blocked nicotinamide adenine dinucleotide phosphate oxidase activity and under anaerobic conditions. We conclude that the Bcc infection model in CGD mice is well suited for the assessment of Bcc virulence.
Publication
Journal: Journal of Cystic Fibrosis
November/20/2014
Abstract
BACKGROUND
Airway inflammation, mediated in part by LTBCF). LTB(4)-receptor inhibition may reduce airway inflammation. We report the results of a randomized, double-blind, placebo-controlled study of the efficacy and safety of the leukotriene B(4) (LTB(4))-receptor antagonist BIIL 284 BS in CF patients.
METHODS
CF patients aged ≥6 years with mild to moderate lung disease were randomized to oral BIIL 284 BS or placebo once daily for 24 weeks. Co-primary endpoints were change in FEV(1) and incidence of pulmonary exacerbation.
RESULTS
After 420 (155 children, 265 adults) of the planned 600 patients were randomized, the trial was terminated after a planned interim analysis revealed a significant increase in pulmonary related serious adverse events (SAEs) in adults receiving BIIL 284 BS. Final analysis revealed SAEs in 36.1% of adults receiving BIIL 284 BS vs. 21.2% receiving placebo (p = 0.007), and in 29.6% of children receiving BIIL 284 BS vs. 22.9% receiving placebo (p = 0.348). In adults, the incidence of protocol-defined pulmonary exacerbation was greater in those receiving BIIL 284 BS than in those receiving placebo (33.1% vs. 18.2% respectively; p = 0.005). In children, the incidence of protocol-defined pulmonary exacerbation was 19.8% in the BIIL 284 BS arm, and 25.7% in the placebo arm (p = 0.38).
CONCLUSIONS
While the cause of increased SAEs and exacerbations due to BIIL 284 BS is unknown, the outcome of this trial provides a cautionary tale for the administration of potent anti-inflammatory compounds to individuals with chronic infections, as the potential to significantly suppress the inflammatory response may increase the risk of infection-related adverse events.
Publication
Journal: Journal of Molecular and Cellular Cardiology
September/25/2016
Abstract
Chronic activation of the myocardial renin angiotensin system (RAS) elevates the local level of angiotensin II (Ang II) thereby inducing pathological cardiac hypertrophy, which contributes to heart failure. However, the precise underlying mechanisms have not been fully delineated. Herein we report a novel paracrine mechanism between cardiac fibroblasts (CF)s and cardiomyocytes whereby Ang II induces pathological cardiac hypertrophy. In cultured CFs, Ang II treatment enhanced exosome release via the activation of Ang II receptor types 1 (AT1R) and 2 (AT2R), whereas lipopolysaccharide, insulin, endothelin (ET)-1, transforming growth factor beta (TGFβ)1 or hydrogen peroxide did not. The CF-derived exosomes upregulated the expression of renin, angiotensinogen, AT1R, and AT2R, downregulated angiotensin-converting enzyme 2, and enhanced Ang II production in cultured cardiomyocytes. In addition, the CF exosome-induced cardiomyocyte hypertrophy was blocked by both AT1R and AT2R antagonists. Exosome inhibitors, GW4869 and dimethyl amiloride (DMA), inhibited CF-induced cardiomyocyte hypertrophy with little effect on Ang II-induced cardiomyocyte hypertrophy. Mechanistically, CF exosomes upregulated RAS in cardiomyocytes via the activation of mitogen-activated protein kinases (MAPKs) and Akt. Finally, Ang II-induced exosome release from cardiac fibroblasts and pathological cardiac hypertrophy were dramatically inhibited by GW4869 and DMA in mice. These findings demonstrate that Ang II stimulates CFs to release exosomes, which in turn increase Ang II production and its receptor expression in cardiomyocytes, thereby intensifying Ang II-induced pathological cardiac hypertrophy. Accordingly, specific targeting of Ang II-induced exosome release from CFs may serve as a novel therapeutic approach to treat cardiac pathological hypertrophy and heart failure.
Publication
Journal: Clinical Endocrinology
November/19/2007
Abstract
BACKGROUND
There is increasing reliance on consensus criteria for decision making. Recent criteria state that acromegaly is excluded by a nadir GH during an oral glucose tolerance test (OGTT) of < 1 microg/l and a normal level of IGF-I.
OBJECTIVE
To study GH and IGF-I assay performance close to cut-off values for active acromegaly.
METHODS
Two serum samples known to give borderline results were sent to all centres participating in the UK National External Quality Assessment Service (NEQAS). Sample A was assigned to be a nadir during an OGTT and sent for GH assessment to 104 centres. Sample B, with a clinical scenario, was sent to 23 centres that measure IGF-I, and these centres were asked to measure IGF-I, interpret the result and provide the source of their reference ranges (RRs).
RESULTS
For sample A, the median GH was 2.6 mU/l (range 1.04-3.5 mU/l). Applying a conversion factor (CF) of 2.0 (1 microg/l = 2 mU/l), the most negatively biased method classified 10% of the values consistent with acromegaly, while the most positively biased method classified all values as consistent with the diagnosis. Applying a CF of 3.0 (1 microg/l = 3 mU/l), only 11% of results were consistent with acromegaly. For sample B, the median IGF-I was 50.8 nmol/l (range 24.3-60.9 nmol/l). All centres used age-related RRs. There was a 50% variation in the upper limit of the RRs between centres. Overall, 30% of the IGF-I results were against the diagnosis. There was little agreement in the RRs quoted by centres using the same method.
CONCLUSIONS
Variability in assay performance, coupled with use of inappropriate CFs and RRs, undermines the applicability of international consensus criteria to local practice.
Publication
Journal: Current Opinion in Psychiatry
May/6/2009
Abstract
OBJECTIVE
The aim of this paper is to review recent findings on inflammatory and oxidative and nitrosative stress (IO&NS) pathways in chronic fatigue and somatization disorder.
RESULTS
Activation of IO&NS pathways is the key phenomenon underpinning chronic fatigue syndrome (CFS): intracellular inflammation, with an increased production of nuclear factor kappa beta (NFkappabeta), cyclo-oxygenase-2 (COX-2) and inducible NO synthase (iNOS); and damage caused by O&NS to membrane fatty acids and functional proteins. These IO&NS pathways are induced by a number of trigger factors, for example psychological stress, strenuous exercise, viral infections and an increased translocation of LPS from gram-bacteria (leaky gut). The 'psychosomatic' symptoms experienced by CFS patients are caused by intracellular inflammation (aches and pain, muscular tension, fatigue, irritability, sadness, and the subjective feeling of infection); damage caused by O&NS (aches and pain, muscular tension and fatigue); and gut-derived inflammation (complaints of irritable bowel). Inflammatory pathways (monocytic activation) are also detected in somatizing disorder.
CONCLUSIONS
'Functional' symptoms, as occurring in CFS and somatization, have a genuine organic cause, that is activation of peripheral and central IO&NS pathways and gut-derived inflammation. The development of new drugs, aimed at treating those disorders, should target these IO&NS pathways.
Publication
Journal: Antimicrobial Agents and Chemotherapy
December/3/2001
Abstract
Endogenous peptide antibiotics are under investigation as inhaled therapeutic agents for cystic fibrosis (CF) lung disease. The bactericidal activities of five cathelicidin peptides (LL37 [human], CAP18 [rabbit], mCRAMP [mouse], rCRAMP [rat], and SMAP29 [sheep]), three novel alpha-helical peptides derived from SMAP29 and termed ovispirins (OV-1, OV-2, and OV-3), and two derivatives of CAP18 were tested by broth microdilution assays. Their MICs were determined for multiply antibiotic-resistant Pseudomonas aeruginosa (n = 24), Burkholderia cepacia (n = 5), Achromobacter xylosoxidans (n = 5), and Stenotrophomonas maltophilia (n = 5) strains isolated from CF patients. SMAP29 was most active and inhibited mucoid and nonmucoid P. aeruginosa strains (MIC, 0.06 to 8 microg/ml). OV-1, OV-2, and OV-3 were nearly as active (MIC, 0.03 to 16 microg/ml), but CAP18 (MIC, 1.0 to 32 microg/ml), CAP18-18 (MIC, 1.0 to >32 microg/ml), and CAP18-22 (MIC, 0.5 to 32 microg/ml) had variable activities. LL37, mCRAMP, and rCRAMP were least active against the clinical isolates studied (MIC, 1.0 to >32 microg/ml). Peptides had modest activities against S. maltophilia and A. xylosoxidans (MIC range, 1.0 to>> 32 microg/ml), but none inhibited B. cepacia. However, CF sputum inhibited the activity of SMAP29 substantially. The effects of peptides on bacterial cell membranes and eukaryotic cells were examined by scanning electron microscopy and by measuring transepithelial cell resistance, respectively. SMAP29 caused the appearance of bacterial membrane blebs within 1 min, killed P. aeruginosa within 1 h, and caused a dose-dependent, reversible decrease in transepithelial resistance within 5 h. The tested cathelicidin-derived peptides represent a novel class of antimicrobial agents and warrant further development as prophylactic or therapeutic agents for CF lung disease.
Publication
Journal: Journal of Clinical Oncology
October/26/2005
Abstract
OBJECTIVE
To describe total fatigue (TF) and chronic fatigue (CF) in 476 long-term Hodgkin's disease survivors (HDSs). The development in CF over time was explored in 280 of the patients who had also been assessed 8 years earlier.
METHODS
In 2003, the Fatigue Questionnaire was mailed to 610 successfully treated HDSs at the Norwegian Radium Hospital from 1971 to 1997. Mean TF scores and occurrence of CF were compared with general population (GP) values.
RESULTS
Four hundred seventy-six complete forms (81%) were received (median age, 46 years; 56% males, median follow-up time, 195 months). There was a positive association between age and TF (P < .05), whereas presence of B symptoms at diagnosis and treatment before 1980 were associated with CF. Mean TF scores were elevated in HDSs compared with the GP (mean TF score, 14.6; 95% CI, 14.1 to 15.7 v 12.1; 95% CI, 11.9 to 12.3, respectively; P < .001), as was the proportion of persons with CF (30% v 11%, respectively; odds ratio = 3.6; P < .001). The 70 patients with CF 8 years earlier still reported higher TF at follow-up than the 210 patients without CF at the previous assessment (mean TF score, 17.0; 95% CI, 15.6 to 18.3 v 13.1; 95% CI, 12.9 to 14.1, respectively; P < .001). Significantly more patients with persisting CF had B symptoms at diagnosis compared with patients who had recovered (P = .05). No significant association with treatment modality and intensity was found.
CONCLUSIONS
Fatigue remains a major complaint in HDSs several years after treatment, but the association between treatment and fatigue still remains unclear. Many HDSs may recover from CF, particularly patients without B symptoms at diagnosis.
Publication
Journal: European Respiratory Journal
September/19/2001
Abstract
Burkholderia cepacia is a plant phytogen and is known as a hardy and versatile organism. Over the past two decades it has emerged as a pathogen in the cystic fibrosis (CF) community, with devastating effects. Pulmonary colonisation can lead to an accelerated decline in lung function. In some cases, it causes a rapid and progressive pneumonic illness termed "cepacia syndrome", which is untreatable and fatal. B. cepacia is inherently resistant to multiple antibiotics and highly transmissible and virulent strains have been identified. CF patients colonised with the organism have to be segregated from their peers to try to prevent cross-infection. However, the pathogenicity of B. cepacia is not limited to CF. Other groups, such as individuals with chronic granulomatous disease and immunocompromised patients are vulnerable and it has caused disease in healthy individuals. However, the agricultural and petrochemical industries are attempting to exploit properties of B. cepacia for use as a biopesticide and biodegradation agent. This article provides an up to date review of clinically based literature on the Burkholderia cepacia complex, highlighting clinical management issues for both cystic fibrosis and non-cystic fibrosis patients. The article also addresses the potential conflict between medicine and agriculture on plans to reintroduce strains of Burkholderia cepacia back into the environment.
Publication
Journal: Human Gene Therapy
November/22/1993
Abstract
A new adenovirus-based vector (Ad2/CFTR-1) has been constructed in which the cDNA encoding the cystic fibrosis transmembrane conductance regulator (CFTR), the cystic fibrosis (CF) gene product, replaces the early region 1 coding sequences, E1a and E1b. The virus retains the E3 region. Ad2/CFTR-1 and a related construct encoding beta-galactosidase replicate in human 293 cells which provide E1 gene functions in trans. Replication of these recombinant viruses was not detected in a variety of other cells, although very limited viral DNA synthesis and transcription from the E4 and L5 regions could be measured. These E1-deletion vectors were also deficient in cellular transformation, shut-off of host cell protein synthesis, and production of cytopathic effects, even at high multiplicities of infection. Ad2/CFTR-1 produced CFTR protein in a variety of cells including airway epithelia from CF patients. Expression of functional CFTR protein in a CF airway epithelial monolayer was detected by correction of the Cl- transport defect characteristic of CF. Surprisingly low multiplicities of infection (0.1 moi) were sufficient to generate CFTR Cl- current across a CF epithelial monolayer in vitro. These data, together with the lack of obvious toxicity, suggest that Ad2/CFTR-1 should be suitable for CF gene therapy.
Publication
Journal: The Journal of laboratory and clinical medicine
December/2/2002
Abstract
One of the hallmarks of progressive renal disease is the development of tubulointerstitial fibrosis. This is frequently preceded by macrophage infiltration, raising the possibility that macrophages relay fibrogenic signals to resident tubulointerstitial cells. The aim of this study was to investigate the potentially fibrogenic role of interleukin-1beta (IL-1beta), a macrophage-derived inflammatory cytokine, on cortical fibroblasts (CFs). Primary cultures of human renal CFs were established and incubated for 24 hours in the presence or absence of IL-1beta. We found that IL-1beta significantly stimulated DNA synthesis (356.7% +/- 39% of control, P <.003), fibronectin secretion (261.8 +/- 11% of control, P <.005), collagen type 1 production, (release of procollagen type 1 C-terminal-peptide, 152.4% +/- 26% of control, P <.005), transforming growth factor-beta (TGF-beta) secretion (211% +/- 37% of control, P <.01), and nitric oxide (NO) production (342.8% +/- 69% of control, P <.002). TGF-beta (1 ng/mL) and the phorbol ester phorbol 12-myristate 13-acetate (PMA, 25 nmol/L) produced fibrogenic effects similar to those of IL-1beta. Neither a NO synthase inhibitor (N(G)-methyl-l-arginine, 1 mmol/L) nor a protein kinase C (PKC) inhibitor (bis-indolylmaleimide 1, 1 micromol/L) altered the enhanced level of fibronectin secretion or DNA synthesis seen in response to IL-1beta treatment. However, addition of a TGF-beta-neutralizing antibody significantly reduced IL-1beta-induced fibronectin secretion (IL-1beta + IgG, 262% +/- 72% vs IL-1beta + alphaTGF-beta 156% +/- 14%, P <.02), collagen type 1 production (IL-1beta + IgG, 176% +/- 28% vs IL-1beta + alphaTGF-beta, 120% +/- 14%, P <.005) and abrogated IL-1beta-induced DNA synthesis (245% +/- 49% vs 105% +/- 21%, P <.005). IL-1beta significantly stimulated CF DNA synthesis and production of fibronectin, collagen type 1, TGFbeta, and NO. The fibrogenic and proliferative action of IL-1beta on CF appears not to involve activation of PKC or production of NO but is at least partly TGFbeta-dependent.
Publication
Journal: Infection and Immunity
March/2/2010
Abstract
Pseudomonas aeruginosa is a serious pathogen in hospitalized, immunocompromised, and cystic fibrosis (CF) patients. P. aeruginosa is motile via a single polar flagellum made of polymerized flagellin proteins differentiated into two major serotypes: a and b. Antibodies to flagella delay onset of infection in CF patients, but whether immunity to polymeric flagella and that to monomeric flagellin are comparable has not been addressed, nor has the question of whether such antibodies might negatively impact Toll-like receptor 5 (TLR5) activation, an important component of innate immunity to P. aeruginosa. We compared immunization with flagella and that with flagellin for in vitro effects on motility, opsonic killing, and protective efficacy using a mouse pneumonia model. Antibodies to flagella were superior to antibodies to flagellin at inhibiting motility, promoting opsonic killing, and mediating protection against P. aeruginosa pneumonia in mice. Protection against the flagellar type strains PAK and PA01 was maximal, but it was only marginal against motile clinical isolates from flagellum-immunized CF patients who nonetheless became colonized with P. aeruginosa. Purified flagellin was a more potent activator of TLR5 than were flagella and also elicited higher TLR5-neutralizing antibodies than did immunization with flagella. Antibody to type a but not type b flagella or flagellin inhibited TLR5 activation by whole bacterial cells. Overall, intact flagella appear to be superior for generating immunity to P. aeruginosa, and flagellin monomers might induce antibodies capable of neutralizing innate immunity due to TLR5 activation, but solid immunity to P. aeruginosa based on flagellar antigens may require additional components beyond type a and type b proteins from prototype strains.
Publication
Journal: Journal of Medical Microbiology
December/18/2002
Abstract
The Burkholderia cepacia complex presently comprises nine genomovars: B. cepacia (genomovar I), B. multivorans (genomovar II), B. cepacia genomovar III, B. stabilis (genomovar IV), B. vietnamiensis (genomovar V), B. cepacia genomovar VI, B. ambifaria (genomovar VII), B. anthina (genomovar VIII) and B. pyrrocinia (genomovar IX). Strains of each genomovar can colonise the respiratory tract of cystic fibrosis (CF) patients. However, the majority of infections in CF patients are caused by B. multivorans and B. cepacia genomovar III isolates. Accurate genomovar-level identification is best achieved through a polyphasic approach combining phenotypic and genotypic analyses. In the present study, the sensitivity and specificity of recA-based genomovar specific primer pairs were evaluated with a collection of 508 B. cepacia complex isolates representing all nine genomovars. The assays for the identification of B. multivorans (sensitivity and specificity, 100%), B. cepacia genomovar III (sensitivity, 92%; specificity, 100%), and B. ambifaria (sensitivity and specificity, 100%) were the most efficient. However, the B. cepacia genomovar I assay lacked sensitivity (72%) and cross-reacted with all B. pyrrocinia isolates examined. Several new recA RFLP types were also revealed within the B. cepacia complex. One of these profiles was shared by a clinical and an environmental B. cepacia-like isolate and by the B. ubonensis type strain. The latter organism is a recently described soil bacterium. Its relationship to the various B. cepacia complex genomovars needs further study.
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