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1.
Indoor Air ; 27(5): 988-1000, 2017 09.
Article in English | MEDLINE | ID: mdl-28303606

ABSTRACT

Fluorescent particles can be markers of bioaerosols and are therefore relevant to nosocomial infections. To date, little research has focused on fluorescent particles in occupied indoor environments, particularly hospitals. In this study, we aimed to determine the spatial and temporal variation of fluorescent particles in two large hospitals in Brisbane, Australia (one for adults and one for children). We used an Ultraviolet Aerodynamic Particle Sizer (UVAPS) to identify fluorescent particle sources, as well as their contribution to total particle concentrations. We found that the average concentrations of both fluorescent and non-fluorescent particles were higher in the adults' hospital (0.06×106 and 1.20×106  particles/m3 , respectively) than in the children's hospital (0.03×106 and 0.33×106  particles/m3 , respectively) (P<.01). However, the proportion of fluorescent particles was higher in the children's hospital. Based on the concentration results and using activity diaries, we were able to identify sources of particle production within the two hospitals. We demonstrated that particles can be easily generated by a variety of everyday activities, which are potential sources of exposure to pathogens. Future studies to further investigate their role in nosocomial infection are warranted.


Subject(s)
Aerosols/analysis , Air Microbiology , Air Pollution, Indoor/analysis , Cross Infection/transmission , Fluorescence , Hospitals/classification , Australia , Environmental Monitoring , Time Factors
2.
Eur J Cancer Care (Engl) ; 23(6): 721-7, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25244252

ABSTRACT

The traditional roles of Australian cancer registries have been incidence, mortality and survival surveillance although increasingly, roles are being broadened to include data support for health-service management and evaluation. In some Australian jurisdictions, cancer stage and other prognostic data are being included in registry databases and this is being facilitated by an increase in structured pathology reporting by pathology and haematology laboratories. Data linkage facilities are being extended across the country at national and jurisdictional level, facilitating data linkage between registry data and data extracts from administrative databases that include treatment, screening and vaccination data, and self-reported data from large population cohorts. Well-established linkage protocols exist to protect privacy. The aim is to gain better data on patterns of care, service outcomes and related performance indicators for health-service management and population health and health-services research, at a time of increasing cost pressures. Barriers include wariness among some data custodians towards releasing data and the need for clearance for data release from large numbers of research ethics committees. Progress is being made though, and proof of concept is being established.


Subject(s)
Delivery of Health Care/organization & administration , Health Services Research/organization & administration , Medical Record Linkage , Neoplasms/therapy , Registries , Australia , Databases, Factual , Evidence-Based Medicine , Humans
3.
Eur J Clin Microbiol Infect Dis ; 32(12): 1583-92, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23832143

ABSTRACT

Pseudomonas aeruginosa is the leading cause of morbidity and mortality in cystic fibrosis (CF). This study examines the role of organism-specific factors in the pathogenesis of very early P. aeruginosa infection in the CF airway. A total of 168 longitudinally collected P. aeruginosa isolates from children diagnosed with CF following newborn screening were genotyped by pulsed-field gel electrophoresis (PFGE) and phenotyped for 13 virulence factors. Ninety-two strains were identified. Associations between virulence factors and gender, exacerbation, persistence, timing of infection and infection site were assessed using multivariate regression analysis. Persistent strains showed significantly lower pyoverdine, rhamnolipid, haemolysin, total protease, and swimming and twitching motility than strains eradicated by aggressive antibiotic treatments. Initial strains had higher levels of virulence factors, and significantly higher phospholipase C, than subsequent genotypically different strains at initial isolation. Strains from males had significantly lower pyoverdine and swimming motility than females. Colony size was significantly smaller in strains isolated during exacerbation than those isolated during non-exacerbation periods. All virulence factors were higher and swimming motility significantly higher in strains from bronchoalveolar lavage (BAL) and oropharyngeal sites than BAL alone. Using unadjusted regression modelling, age at initial infection and age at isolation of a strain showed U-shaped profiles for most virulence factors. Among subsequent strains, longer time since initial infection meant lower levels of most virulence factors. This study provides new insight into virulence factors underpinning impaired airway clearance seen in CF infants, despite aggressive antibiotic therapy. This information will be important in the development of new strategies to reduce the impact of P. aeruginosa in CF.


Subject(s)
Bacterial Proteins/biosynthesis , Cystic Fibrosis/microbiology , Pseudomonas Infections/microbiology , Pseudomonas aeruginosa/metabolism , Virulence Factors/biosynthesis , Bacterial Proteins/genetics , Child, Preschool , Female , Genotype , Humans , Infant , Male , Pseudomonas Infections/complications , Pseudomonas aeruginosa/genetics , Pseudomonas aeruginosa/isolation & purification , Pseudomonas aeruginosa/pathogenicity , Randomized Controlled Trials as Topic , Virulence Factors/genetics
4.
Clin Microbiol Infect ; 19(3): 266-72, 2013 Mar.
Article in English | MEDLINE | ID: mdl-22329595

ABSTRACT

Studies of the type 3 secretion system (T3SS) in Pseudomonas aeruginosa isolates from chronically infected older children and adults with cystic fibrosis (CF) show a predominantly exoS+/exoU- (exoS+) genotype and loss of T3SS effector secretion over time. Relatively little is known about the role of the T3SS in the pathogenesis of early P. aeruginosa infection in the CF airway. In this longitudinal study, 168 P. aeruginosa isolates from 58 children diagnosed with CF following newborn screening and 47 isolates from homes of families with or without children with CF were genotyped by pulsed-field gel electrophoresis (PFGE) and T3SS genotype and phenotype determined using multiplex PCR and western blotting. Associations were sought between T3SS data and clinical variables and comparisons made between T3SS data of clinical and environmental PFGE genotypes. Seventy-seven of the 92 clinical strains were exoS+ (71% secretors (ExoS+)) and 15 were exoU+ (93% secretors (ExoU+)). Initial exoS+ strains were five times more likely to secrete ExoS than subsequent exoS+ strains at first isolation. The proportion of ExoS+ strains declined with increasing age at acquisition. No associations were found between T3SS characteristics and gender, site of isolation, exacerbation, a persistent strain or pulmonary outcomes. Fourteen of the 23 environmental strains were exoS+ (79% ExoS+) and nine were exoU+ (33% ExoU+). The exoU+ environmental strains were significantly less likely to secrete ExoU than clinical strains. This study provides new insight into the T3SS characteristics of P. aeruginosa isolated from the CF airway early in life.


Subject(s)
Bacterial Secretion Systems/genetics , Bronchopneumonia/microbiology , Cystic Fibrosis/complications , Pseudomonas Infections/microbiology , Pseudomonas aeruginosa/genetics , Pseudomonas aeruginosa/metabolism , Virulence Factors/genetics , Virulence Factors/metabolism , ADP Ribose Transferases/genetics , ADP Ribose Transferases/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Bacterial Toxins/genetics , Bacterial Toxins/metabolism , Blotting, Western , Child , Child, Preschool , Electrophoresis, Gel, Pulsed-Field , Female , Genotype , Humans , Infant , Infant, Newborn , Longitudinal Studies , Male , Molecular Typing , Multiplex Polymerase Chain Reaction , Phenotype , Pseudomonas aeruginosa/isolation & purification
5.
Pflugers Arch ; 463(5): 679-84, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22371140

ABSTRACT

The aim of the study was to examine features of the myogenic response of a conduit artery to the presence and absence of pulsatile pressure. The iliac arteries of 16 anaesthetised pigs (10 in control conditions, 6 under sympathetic blockade) were instrumented with flowmeter, sonomicrometry crystals for diameter measurement, a micro-tip manometer for pressure measurement and snares placed proximally and distally to the crystals to isolate a test segment from the remainder of the arterial system. When the snares were tightened to occlude the test segment, systemic arterial pressure remained constant. There was a large shift in the pressure-diameter relationship, in that there was a rapid decline in test segment pressure for the same diameter. This indicated arterial wall smooth muscle relaxation in response to removal of pulsatility of arterial pressure. The difference in mean pressure between pulsatility present and absent was significant (p < 0.0001, paired t test, n = 10). Before proximal and distal occlusion, test segment pressure was (mean ± SD) 92.26 ± 12.39 mmHg, whereas after distal and proximal occlusion at the same diameter, it was 42.34 ± 10.87 mmHg. We conclude that in the presence of pulsatile pressure, there is a large proportion of arterial wall smooth muscle tone related to stretch of the arterial wall during the cardiac cycle, indicating that, under normal pulsatile pressure conditions, much of the normal tone can be attributed to the pulsatile component of the arterial myogenic response.


Subject(s)
Blood Pressure/physiology , Iliac Artery/physiology , Muscle Tonus/physiology , Muscle, Smooth, Vascular/physiology , Animals , Female , Muscle Relaxation/physiology , Swine
6.
J Bone Joint Surg Br ; 93(10): 1411-5, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21969444

ABSTRACT

We compared revision and mortality rates of 4668 patients undergoing primary total hip and knee replacement between 1989 and 2007 at a University Hospital in New Zealand. The mean age at the time of surgery was 69 years (16 to 100). A total of 1175 patients (25%) had died at follow-up at a mean of ten years post-operatively. The mean age of those who died within ten years of surgery was 74.4 years (29 to 97) at time of surgery. No change in comorbidity score or age of the patients receiving joint replacement was noted during the study period. No association of revision or death could be proven with higher comorbidity scoring, grade of surgeon, or patient gender. We found that patients younger than 50 years at the time of surgery have a greater chance of requiring a revision than of dying, those around 58 years of age have a 50:50 chance of needing a revision, and in those older than 62 years the prosthesis will normally outlast the patient. Patients over 77 years old have a greater than 90% chance of dying than requiring a revision whereas those around 47 years are on average twice as likely to require a revision than die. This information can be used to rationalise the need for long-term surveillance and during the informed consent process.


Subject(s)
Arthroplasty, Replacement, Hip/mortality , Arthroplasty, Replacement, Knee/mortality , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , Comorbidity , Epidemiologic Methods , Female , Hip Prosthesis , Humans , Knee Prosthesis , Male , Middle Aged , New Zealand/epidemiology , Prosthesis Failure , Reoperation/statistics & numerical data , Young Adult
7.
J Cyst Fibros ; 10(4): 234-42, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21441078

ABSTRACT

BACKGROUND: Previous aztreonam for inhalation solution (AZLI) studies included patients with cystic fibrosis, Pseudomonas aeruginosa (PA) airway infection, and forced expiratory volume in 1s (FEV(1)) 25% to 75% predicted. This double-blind, multicenter, randomized, placebo-controlled trial enrolled patients (≥6 years) with FEV(1)>75% predicted. METHODS: AZLI 75 mg (n=76) or placebo (n=81) was administered 3-times daily for 28days with a 14-day follow-up. RESULTS: Day 28 treatment effects were 1.8points for CFQ-R-Respiratory Symptoms Scale (95%CI: -2.8, 6.4; p=0.443; primary endpoint); -1.2 for log(10) sputum PA colony-forming units (p=0.016; favoring AZLI), and 2.7% for relative FEV(1)% predicted (p=0.021; favoring AZLI). Treatment effects favoring AZLI were larger for patients with baseline FEV(1) <90% predicted compared to ≥90% predicted. AZLI was well-tolerated. CONCLUSIONS: Effects on respiratory symptoms were modest; however, FEV(1) improvements and bacterial density reductions support a possible role for AZLI in these relatively healthy patients.


Subject(s)
Anti-Bacterial Agents/administration & dosage , Aztreonam/administration & dosage , Cystic Fibrosis/microbiology , Pseudomonas Infections/drug therapy , Pseudomonas aeruginosa/drug effects , Administration, Inhalation , Adolescent , Anti-Bacterial Agents/adverse effects , Aztreonam/adverse effects , Child , Female , Forced Expiratory Volume/drug effects , Humans , Male , Placebos , Severity of Illness Index , Therapeutics , Young Adult
8.
Clin Microbiol Infect ; 17(9): 1403-8, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21129101

ABSTRACT

Pseudomonas aeruginosa genotyping relies mainly upon DNA fingerprinting methods, which can be subjective, expensive and time-consuming. The detection of at least three different clonal P. aeruginosa strains in patients attending two cystic fibrosis (CF) centres in a single Australian city prompted the design of a non-gel-based PCR method to enable clinical microbiology laboratories to readily identify these clonal strains. We designed a detection method utilizing heat-denatured P. aeruginosa isolates and a ten-single-nucleotide polymorphism (SNP) profile. Strain differences were detected by SYBR Green-based real-time PCR and high-resolution melting curve analysis (HRM10SNP assay). Overall, 106 P. aeruginosa sputum isolates collected from 74 patients with CF, as well as five reference strains, were analysed with the HRM10SNP assay, and the results were compared with those obtained by pulsed-field gel electrophoresis (PFGE). The HRM10SNP assay accurately identified all 45 isolates as members of one of the three major clonal strains characterized by PFGE in two Brisbane CF centres (Australian epidemic strain-1, Australian epidemic strain-2 and P42) from 61 other P. aeruginosa strains from Australian CF patients and two representative overseas epidemic strain isolates. The HRM10SNP method is simple, is relatively inexpensive and can be completed in <3 h. In our setting, it could be made easily available for clinical microbiology laboratories to screen for local P. aeruginosa strains and to guide infection control policies. Further studies are needed to determine whether the HRM10SNP assay can also be modified to detect additional clonal strains that are prevalent in other CF centres.


Subject(s)
Cystic Fibrosis/microbiology , Pseudomonas Infections/microbiology , Pseudomonas aeruginosa/genetics , Real-Time Polymerase Chain Reaction/methods , Australia , Base Sequence , Electrophoresis, Gel, Pulsed-Field , Humans , Molecular Sequence Data , Polymorphism, Single Nucleotide , Pseudomonas aeruginosa/isolation & purification
9.
Br J Pharmacol ; 160(7): 1573-6, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20649560

ABSTRACT

British Journal of Pharmacology (BJP) is pleased to publish a new set of guidelines for reporting research involving animals, simultaneously with several other journals; the 'ARRIVE' guidelines (Animals in Research: Reporting In Vivo Experiments). This editorial summarizes the background to the guidelines, gives our view of their significance, considers aspects of specific relevance to pharmacology, re-states BJP's guidelines for authors on animal experiments and indicates our commitment to carrying on discussion of this important topic. We also invite feedback via the British Pharmacological Society website.


Subject(s)
Animal Experimentation/standards , Editorial Policies , Guidelines as Topic , Animal Experimentation/statistics & numerical data , Animals , Biomedical Research/standards , Pharmacology/standards , United Kingdom
10.
Br J Pharmacol ; 158(2): 393-4, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19732059

ABSTRACT

A themed section in this issue of Br J Pharmacol, on 'Advances in Nutritional Pharmacology', provides a valuable and timely update on progress in this area. The value of dietary components to improvement in health and, particularly, to prevention of cardiovascular disease and cancer, is frequently reported in the media and therefore often captures the attention of the wider public. Understanding the pharmacological mechanisms by which nutritional elements confer their health benefits enables us to keep the public informed, but also aids in the identification of new targets for drug development. In recent years there has been significant progress in this field. Four rapidly developing areas are reviewed. Vosper (2009) covers the identification of a receptor for niacin and the subsequent development of selective agonists as lipid lowering agents. Wu-Wong (2009) describes the development of new Vitamin D analogues for the treatment of cardiovascular disease. de Roos et al. (2009) provide detailed insight into how omega-3 fatty acids, also known as longchain n-3 polyunsaturated fatty acids (PUFAs) protect against cardiovascular disease. Zhou et al. (2009) cover the mechanisms underlying the beneficial effects of resveretrol in protection against cancer. These reviews are complimented by three key original articles focusing on endogenous mechanisms of weight control involving endocannabinoids (Izzo et al., 2009), a circulating protein, the soluble leptin receptor (Zhang & Scarpace, 2009) and a treatment, zinc plus cyclo-(His-Pro) (CHP), known to increase insulin metabolism (Song et al., 2009).


Subject(s)
Cardiovascular Diseases/prevention & control , Neoplasms/prevention & control , Nutrition Therapy , Animals , Drug Design , Humans
11.
J Bone Joint Surg Br ; 91(7): 859-64, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19567847

ABSTRACT

We reviewed the results at nine to 13 years of 125 total hip replacements in 113 patients using the monoblock uncemented Morscher press-fit acetabular component. The mean age at the time of operation was 56.9 years (36 to 74). The mean clinical follow-up was 11 years (9.7 to 13.5) and the mean radiological follow-up was 9.4 years (7.7 to 13.1). Three hips were revised, one immediately for instability, one for excessive wear and one for deep infection. No revisions were required for aseptic loosening. A total of eight hips (7.0%) had osteolytic lesions greater than 1 cm, in four around the acetabular component (3.5%). One required bone grafting behind a well-fixed implant. The mean wear rate was 0.11 mm/year (0.06 to 0.78) and was significantly higher in components with a steeper abduction angle. Kaplan-Meier survival curves at 13 years showed survival of 96.8% (95% confidence interval 90.2 to 99.0) for revision for any cause and of 95.7% (95% confidence interval 88.6 to 98.4) for any acetabular re-operation.


Subject(s)
Acetabulum/surgery , Arthroplasty, Replacement, Hip/methods , Hip Joint/surgery , Prosthesis-Related Infections/surgery , Acetabulum/diagnostic imaging , Adult , Aged , Equipment Failure Analysis , Female , Follow-Up Studies , Hip Joint/diagnostic imaging , Hip Prosthesis , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Prosthesis Design , Prosthesis-Related Infections/diagnostic imaging , Radiography , Reoperation/statistics & numerical data
12.
Auton Autacoid Pharmacol ; 29(3): 73-84, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19566747

ABSTRACT

1 Mast cells have classically been regarded as the 'bad guys' in the setting of acute myocardial ischaemia, where their released contents are believed to contribute both to tissue injury and electrical disturbances resulting from ischaemia. Recent evidence suggests, however, that if mast cell degranulation occurs in advance of ischaemia onset, this may be cardioprotective by virtue of the depletion of mast cell contents that can no longer act as instruments of injury when the tissue becomes ischaemic. 2 Many peptides, such as ET-1, adrenomedullin, relaxin and atrial natriuretic peptide, have been demonstrated to be cardioprotective when given prior to the onset of myocardial ischaemia, although their physiological functions are varied and the mechanisms of their cardioprotective actions appear to be diverse and often ill defined. However, one common denominator that is emerging is the ability of these peptides to modulate mast cell degranulation, raising the possibility that peptide-induced mast cell degranulation or stabilization may hold the key to a common mechanism of their cardioprotection. 3 The aim of this review was to consolidate the evidence implying that mast cell degranulation could play both a detrimental and protective role in myocardial ischaemia, depending upon when it occurs, and that this may underlie the cardioprotective effects of a range of diverse peptides that exerts physiological effects within the cardiovascular system.


Subject(s)
Cardiotonic Agents , Heart Diseases/physiopathology , Mast Cells/physiology , Neuropeptides/pharmacology , Neuropeptides/physiology , Animals , Cell Degranulation , Heart Diseases/pathology , Humans , Myocardial Ischemia/pathology , Myocardial Ischemia/physiopathology , Myocardium/pathology
13.
Thorax ; 64(11): 926-31, 2009 Nov.
Article in English | MEDLINE | ID: mdl-19574243

ABSTRACT

BACKGROUND: Pseudomonas aeruginosa is the most common bacterial pathogen in patients with cystic fibrosis (CF). Current infection control guidelines aim to prevent transmission via contact and respiratory droplet routes and do not consider the possibility of airborne transmission. It was hypothesised that subjects with CF produce viable respirable bacterial aerosols with coughing. METHODS: A cross-sectional study was undertaken of 15 children and 13 adults with CF, 26 chronically infected with P aeruginosa. A cough aerosol sampling system enabled fractioning of respiratory particles of different sizes and culture of viable Gram-negative non-fermentative bacteria. Cough aerosols were collected during 5 min of voluntary coughing and during a sputum induction procedure when tolerated. Standardised quantitative culture and genotyping techniques were used. RESULTS: P aeruginosa was isolated in cough aerosols of 25 subjects (89%), 22 of whom produced sputum samples. P aeruginosa from sputum and paired cough aerosols were indistinguishable by molecular typing. In four cases the same genotype was isolated from ambient room air. Approximately 70% of viable aerosols collected during voluntary coughing were of particles

Subject(s)
Cough/microbiology , Cystic Fibrosis/microbiology , Gram-Negative Bacteria/isolation & purification , Gram-Negative Bacterial Infections/microbiology , Adolescent , Adult , Child , Chronic Disease , Cross-Sectional Studies , Female , Forced Expiratory Volume , Gram-Negative Bacterial Infections/transmission , Humans , Inhalation Exposure , Male , Middle Aged , Sputum/microbiology , Young Adult
14.
Br J Pharmacol ; 157(5): 716-23, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19422371

ABSTRACT

BACKGROUND AND PURPOSE: The aim of this study was to investigate whether the previously reported anti-arrhythmic effect of endothelin-1 (ET-1) is mediated by degranulation of cardiac mast cells prior to myocardial ischaemia. EXPERIMENTAL APPROACH: Male Sprague-Dawley rats received either ET-1 (1.6 nmolxkg(-1)) in the presence or absence of disodium cromoglycate (DSCG; 20 mgxkg(-1)xh(-1)) prior to coronary artery occlusion (CAO). In separate experiments rats were given compound 48/80 (50 microgxkg(-1)) to compare the effects of ET-1 with those of a known mast cell degranulator. Ischaemia-induced ventricular arrhythmias were detected through continuous monitoring of a lead I electrocardiogram. After 30 min of CAO, the hearts were removed and mast cell degranulation determined by histological analysis. A parallel series of sham groups were performed to determine the direct effects of ET-1 and compound 48/80 on mast cell degranulation in the absence of ischaemia. KEY RESULTS: ET-1 and compound 48/80 both exerted profound anti-arrhythmic effects, significantly reducing the total number of ventricular ectopic beats (P < 0.001) and the incidence of ventricular fibrillation (P < 0.05). These anti-arrhythmic effects were abolished by concomitant DSCG infusion prior to CAO. In sham animals ET-1 and compound 48/80 both induced mast cell degranulation (P < 0.001), an effect which was abolished by DSCG, confirming their ability to induce degranulation of mast cells. CONCLUSIONS AND IMPLICATIONS: These results demonstrate for the first time that when given prior to ischaemia ET-1 mediates its anti-arrhythmic effects, at least in part, via cardiac mast cell degranulation.


Subject(s)
Cell Degranulation , Endothelin-1/metabolism , Heart Rate , Histamine Release , Mast Cells/immunology , Myocardial Ischemia/immunology , Ventricular Fibrillation/prevention & control , Ventricular Premature Complexes/prevention & control , Animals , Anti-Arrhythmia Agents/administration & dosage , Blood Pressure , Cell Degranulation/drug effects , Cromolyn Sodium/administration & dosage , Disease Models, Animal , Electrocardiography , Endothelin-1/administration & dosage , Heart Rate/drug effects , Histamine Release/drug effects , Injections, Intravenous , Male , Mast Cells/drug effects , Myocardial Ischemia/complications , Myocardial Ischemia/physiopathology , Rats , Rats, Sprague-Dawley , Ventricular Fibrillation/etiology , Ventricular Fibrillation/immunology , Ventricular Fibrillation/physiopathology , Ventricular Premature Complexes/immunology , Ventricular Premature Complexes/physiopathology , p-Methoxy-N-methylphenethylamine/administration & dosage
15.
Acta Physiol (Oxf) ; 194(3): 207-13, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18577181

ABSTRACT

AIM: We tested the hypothesis that dilatation of a feeding artery may be elicited by transmission of a signal through the tissue of the arterial wall from a vasodilated peripheral vascular bed. METHODS: In eight pentobarbital anaesthetized pigs, acetylcholine (ACh, an endothelium-dependent vasodilator) was injected intra-arterially above (upstream) and below (downstream) a test segment of the left iliac artery, the diameter of which was measured continuously by sonomicrometry. RESULTS: Under control conditions, ACh injections upstream and downstream of the test segment caused dilatation. Downstream injection dilated the peripheral arterioles, resulting in increased blood flow and proximal dilatation. This is a shear stress, nitric oxide (NO)-dependent response. The experiment was then repeated after applying a stenosis to prevent the increased flow caused by downstream injection of ACh; the stenosis was placed either above the site of diameter measurement to allow retrograde conduction, or below that site to prevent distally injected ACh reaching the measurement site. Under these conditions, downstream injection of ACh had a minimal effect on the shear stress of the test segment with no increase in test segment diameter. This was not due to endothelial damage or dysfunction as injection of ACh upstream still caused a large increase in test segment diameter. CONCLUSIONS: Our results indicate that dilatation of the feeding artery of a vasodilated bed is caused by increased shear stress within the feeding artery and not via a signal transmitted through the arterial wall from below.


Subject(s)
Femur/blood supply , Iliac Artery/physiology , Vasodilation/physiology , Acetylcholine/pharmacology , Anesthesia, General , Animals , Blood Pressure/drug effects , Female , Regional Blood Flow/drug effects , Stress, Mechanical , Sus scrofa , Vasodilation/drug effects , Vasodilator Agents/pharmacology
16.
Eur Respir J ; 30(3): 487-95, 2007 Sep.
Article in English | MEDLINE | ID: mdl-17537764

ABSTRACT

Four randomised, placebo-controlled trials have previously documented the clinical benefits of azithromycin (AZM) in cystic fibrosis (CF) patients. The present study examined whether the beneficial effect of AZM is equivalent when administered daily or weekly. A double-blind, randomised study was carried out in 208 CF patients aged 6-58 yrs who were assigned to AZM either 250 mg daily (n = 103) or 1,200 mg weekly (n = 105) for 6 months, with assessments at baseline and at 1, 3, 6 and 7 months. Patients were taken from five adult and children CF centres in South-east Queensland, Australia. Equivalence was demonstrated between the two groups (daily versus weekly) with respect to improvements in lung function (forced expiratory volume in one second and forced vital capacity), C-reactive protein, days spent in hospital, admission rates and nutrition (body mass index, z-scores) using 95% confidence intervals with a tolerance interval of +/-10%. In patients aged <18 yrs the daily group had significantly better improvements in z-scores for height and weight after 6 months. In children, a nutritional advantage for daily administration was found. Gastro-intestinal adverse effects were more common with weekly therapy. Apart from these findings, daily and weekly administered azithromycin demonstrated similar outcomes for cystic fibrosis patients.


Subject(s)
Anti-Bacterial Agents/administration & dosage , Azithromycin/administration & dosage , Cystic Fibrosis/drug therapy , Adolescent , Adult , Child , Dose-Response Relationship, Drug , Double-Blind Method , Drug Administration Schedule , Female , Follow-Up Studies , Forced Expiratory Volume/drug effects , Humans , Male , Middle Aged , Opportunistic Infections/prevention & control , Pneumonia, Bacterial/prevention & control , Vital Capacity/drug effects
17.
J Pharmacol Exp Ther ; 320(1): 419-26, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17005918

ABSTRACT

Statins possess anti-inflammatory effects that may contribute to their ability to slow atherogenesis, whereas nitric oxide (NO) also influences inflammatory cell adhesion. This study aimed to determine whether a novel NO-donating pravastatin derivative, NCX 6550 [(1S-[1alpha(betaS*,deltaS*),2alpha,6alpha,8beta-(R*),8a alpha]]-1,2,6,7,8,8a-hexahydro-beta,delta,6-trihydroxy-2-methyl-8-(2-methyl-1-oxobutoxy)-1-naphthalene-heptanoic acid 4-(nitrooxy)butyl ester)], has greater anti-inflammatory properties compared with pravastatin in normal and atherosclerotic apolipoprotein E receptor knockout (ApoE-/-) mice. C57BL/6 and ApoE-/- mice were administered pravastatin (40 mg/kg), NCX 6550 (48.5 mg/kg), or vehicle orally for 5 days. Ex vivo studies assessed splenocyte adhesion to arterial segments and splenocyte reactive oxygen species (ROS) generation. NCX 6550 significantly reduced splenocyte adhesion to artery segments in both C57BL/6 (8.8 +/- 1.9% versus 16.6 +/- 6.7% adhesion; P < 0.05) and ApoE-/- mice (9.3 +/- 2.9% versus 23.4 +/- 4.6% adhesion; P < 0.05) concomitant with an inhibition of endothelial intercellular adhesion molecule-1 expression. NCX 6550 also significantly reduced phorbol 12-myristate 13-acetate-induced ROS production that was enhanced in isolated ApoE-/- splenocytes. Conversely, pravastatin had no significant effects on adhesion in normal or ApoE-/- mice but reduced the enhanced ROS production from ApoE-/- splenocytes. In separate groups of ApoE-/- mice, NCX 6550 significantly enhanced endothelium-dependent relaxation to carbachol in aortic segments precon-tracted with phenylephrine (-logEC(50), 6.37 +/- 0.37) compared with both vehicle-treated (-logEC50, 5.81 +/- 0.15; P < 0.001) and pravastatin-treated (-logEC50, 5.57 +/- 0.45; P < 0.05) mice. NCX 6550 also significantly reduced plasma monocyte chemoattractant protein-1 levels (648.8 pg/ml) compared with both vehicle (1191.1 pg/ml; P < 0.001) and pravastatin (847 +/- 71.0 pg/ml; P < 0.05) treatment. These data show that NCX 6550 exerts superior anti-inflammatory actions compared with pravastatin, possibly through NO-related mechanisms.


Subject(s)
Atherosclerosis/metabolism , Nitrates/pharmacology , Nitric Oxide Donors/pharmacology , Pravastatin/analogs & derivatives , Reactive Oxygen Species/metabolism , Spleen/drug effects , Animals , Apolipoproteins E/physiology , Cell Adhesion/drug effects , Chemokine CCL2/blood , Cholesterol/blood , Endothelium, Vascular/drug effects , Endothelium, Vascular/physiology , Female , Intercellular Adhesion Molecule-1/analysis , Male , Mice , Mice, Inbred C57BL , Pravastatin/pharmacology , Spleen/cytology , Spleen/metabolism , Thrombin/pharmacology
18.
Br J Pharmacol ; 149(5): 591-9, 2006 Nov.
Article in English | MEDLINE | ID: mdl-16981001

ABSTRACT

BACKGROUND AND PURPOSE: Protease-activated receptor-2 (PAR-2) is expressed on lymphocytes and endothelial cells, and plays a significant role in inflammatory reactions. Since leukocyte-endothelial cell interaction and reactive oxygen species (ROS) generation are hallmarks of the development of inflammation, the effects of PAR-2 activation by trypsin on lymphocyte adhesion and ROS generation was examined utilising PAR-2 wild type and knockout (PAR-2-/-) mice. EXPERIMENTAL APPROACH: Lymphocyte adhesion to the luminal surface of mouse isolated aortae was measured using 51Cr-labelled leukocytes and ROS generation from isolated lymphocytes was quantified using chemiluminescence. KEY RESULTS: Trypsin induced adhesion of lymphocytes when added exogenously to the endothelial surface of the aorta for 30 min. Similarly, increased lymphocyte adhesion was also observed when mice were injected with trypsin intravenously 24 h prior to the adhesion assay, an effect which was partly ICAM-1 mediated. Trypsin also increased ROS generation from isolated mouse lymphocytes in a dose-dependent manner. The increase in lymphocyte adhesion and ROS production in response to trypsin were abolished in PAR-2-/- mice indicating a PAR-2 dependent mechanism. Superoxide dismutase had a greater inhibitory effect in PAR-2-/- mice compared to wild type mice when lymphocytes were stimulated with PMA but not trypsin. CONCLUSIONS AND IMPLICATIONS: The present study indicates that activation of PAR-2 may be an important factor in modulating lymphocyte adhesion and ROS generation. The results have implications for developing anti-inflammatory strategies.


Subject(s)
CD4-Positive T-Lymphocytes/metabolism , Reactive Oxygen Species/metabolism , Receptor, PAR-2/physiology , Animals , Aorta, Thoracic/cytology , Aorta, Thoracic/drug effects , Aorta, Thoracic/metabolism , B-Lymphocytes/cytology , B-Lymphocytes/drug effects , B-Lymphocytes/metabolism , CD11b Antigen/analysis , CD4-Positive T-Lymphocytes/cytology , CD4-Positive T-Lymphocytes/drug effects , Cell Adhesion/drug effects , Cell Adhesion/physiology , Dose-Response Relationship, Drug , Female , Flow Cytometry , In Vitro Techniques , Intercellular Adhesion Molecule-1/metabolism , Luminescent Measurements/methods , Male , Mice , Mice, Knockout , Myeloid Cells/cytology , Myeloid Cells/drug effects , Myeloid Cells/metabolism , P-Selectin/metabolism , Receptor, PAR-2/genetics , Receptor, PAR-2/metabolism , Spleen/cytology , Spleen/drug effects , Spleen/metabolism , Superoxide Dismutase/pharmacology , Tetradecanoylphorbol Acetate/pharmacology , Trypsin/pharmacology
19.
Thorax ; 61(2): 146-54, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16384878

ABSTRACT

BACKGROUND: A study was undertaken to observe the gains in bone mass in children and adolescents with cystic fibrosis (CF) over 24 months and to examine the relationship between areal bone mineral density (aBMD) and associated clinical parameters including physical activity, nutrition, and 25-hydroxyvitamin D (25OHD). METHODS: Areal BMD of the total body (TB), lumbar spine (LS), and total femoral neck (FNt) were repeatedly measured in 85 subjects aged 5-18 years with CF and 100 age and sex matched controls over 2 years. At each visit anthropometric variables, nutritional parameters, pubertal status, disease severity, physical activity, dietary calcium, caloric intake, and serum 25OHD were assessed and related to aBMD. RESULTS: After adjusting for age, sex, and height Z-score, gains in LS aBMD in children (5-10 years) and TB and FNt aBMD in adolescents (11-18 years) with CF were significantly less than in controls. Lean tissue mass was significantly associated with TB and LS aBMD gains in children and adolescents and explained a significant proportion of the aBMD deficit observed. Lung function parameters were significantly associated with aBMD gains in adolescents with CF. CONCLUSIONS: Inadequate bone mass accrual during childhood and adolescence contributes to the low bone mass observed in adults with CF. Accounting for the height discrepancy which is frequently observed in those with CF, in addition to age and sex, is important when assessing low bone mass in children and adolescents with CF. To optimise an individual's potential to acquire maximal bone mass, it is necessary to maximise nutritional status and limit the progression of chronic suppurative lung disease.


Subject(s)
Bone Density/physiology , Cystic Fibrosis/physiopathology , Adolescent , Age Factors , Case-Control Studies , Child , Child, Preschool , Female , Femur Neck , Forced Expiratory Volume/physiology , Humans , Longitudinal Studies , Lumbar Vertebrae , Male , Sex Characteristics , Vital Capacity/physiology
20.
J Pharmacol Exp Ther ; 316(3): 1107-14, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16260580

ABSTRACT

The aim of this study was to assess the effect of chronic administration of NCX4016 [2 acetoxy-benzoate 2-(2-nitroxymethyl)-phenyl ester], a nitric oxide-releasing aspirin derivative on the consequences of coronary artery occlusion in streptozotocin-diabetic rats. Rats were made diabetic by injection of streptozotocin (60 mg kg(-1)) and received insulin (2.5 U kg(-1) s.c.) daily for 4 weeks. Animals received vehicle (1 ml kg(-1) polyethylene glycol), aspirin (65.2 mg kg(-1)), NCX4016 (60 mg kg(-1)), or (iv) NCX4016 (120 mg kg(-1)) orally, once daily for the last 5 days before coronary artery occlusion (CAO). One hour after the last dose, pentobarbital-anesthetized rats were subjected to CAO for 30 min followed by 120-min reperfusion. Neither drug significantly modified initial hemodynamics or plasma glucose levels compared with vehicle treatment in either nondiabetic or diabetic rats. Neither drug modified the total ventricular premature beat (VPB) count in normal animals, although NCX4016, but not aspirin, reduced the total VPB count and the incidence of ventricular tachycardia in diabetic rats. In nondiabetic animals, both aspirin and NCX4016 reduced infarct size. However, in diabetic rats, infarct size was reduced only by the larger dose of NCX4016 (120 mg kg(-1)) but not by aspirin or the lower dose of NCX4016. These results demonstrate that the cardioprotective effects of NCX4016 are reduced in the presence of diabetes compared with the effects seen in nondiabetic animals. In summary, the present study confirms the protective effect of NCX4016 against ischemia-reperfusion injury in the normal rat heart and demonstrates for the first time its protective effect in the heart of streptozotocin-diabetic rats.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Aspirin/analogs & derivatives , Diabetes Mellitus, Experimental/physiopathology , Myocardial Ischemia/drug therapy , Myocardial Reperfusion Injury/prevention & control , Animals , Aspirin/pharmacology , Aspirin/therapeutic use , Blood Pressure/drug effects , Calcimycin/pharmacology , Heart Rate/drug effects , Male , Nitric Oxide/physiology , Rats , Rats, Sprague-Dawley , Streptozocin
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