Loss of incretin effect contributes to postprandial hyperglycaemia in cystic fibrosis-related diabetes.

AIM: To investigate the incretin axis in people with cystic fibrosis. METHODS: Adults with cystic fibrosis-related diabetes, cystic fibrosis without diabetes, and controls (adults without cystic fibrosis and without diabetes) underwent an oral glucose tolerance test and then a closely matched isoglycaemic i.v. glucose infusion. On each occasion, glucose, insulin, C-peptide, total and active glucagon-like peptide-1 and gastric inhibitory polypeptide responses were recorded and incremental areas under curves were calculated for 60 and 240 min. RESULTS: Five adults with cystic fibrosis-related diabetes, six with cystic fibrosis without diabetes and six controls, matched for age and BMI, completed the study. Glucose during oral glucose tolerance test closely matched those during isoglycaemic i.v. glucose infusion. The calculated incretin effect was similar in the control group and the cystic fibrosis without diabetes group (28% and 29%, respectively), but was lost in the cystic fibrosis-related diabetes group (cystic fibrosis-related diabetes vs control group: -6% vs 28%; p=0.03). No hyposecretion of glucagon-like peptide-1 or gastric inhibitory polypeptide was observed; conversely, 60-min incremental area under the curve for total glucagon-like peptide-1 was significantly higher in the cystic fibrosis-related diabetes group than in the control group [1070.4 (254.7) vs 694.97 (308.1); p=0.03] CONCLUSIONS: The incretin effect was lost in cystic fibrosis-related diabetes despite adequate secretion of the incretin hormones. These data support the concept that reduced incretin hormone insulinotropic activity contributes significantly to postprandial hyperglycaemia in cystic fibrosis-related diabetes.

Comparison of real time diagnostic chemistries to detect Pseudomonas aeruginosa in respiratory samples from cystic fibrosis patients.

BACKGROUND: Early eradication therapy is key to keeping the airways Pseudomonas aeruginosa infection-free and rapid identification is essential. METHODS: We used rapid DNA extraction and qPCR assays to detect bacterial, P. aeruginosa and strain-specific targets in samples using two qPCR chemistries. Using 459 respiratory samples from adult and children CF patients, we compared two qPCR methods to culture-based methods in terms of sensitivity and time to result. RESULTS: For adult samples, there was 100% concordance between methods. There was no clear pattern in fluctuations in P. aeruginosa number during exacerbation. In child samples, qPCR methods identified additional P. aeruginosa positive samples. The time-to-result was reduced by over 24h and copy number and colony forming unit could differ dramatically in some samples. CONCLUSION: If adopted, these methods could significantly improve early P. aeruginosa detection in diagnostic laboratories and therefore play a pivotal role in prolonging infection-free airways in CF patients.

Transmission of Pseudomonas aeruginosa epidemic strain from a patient with cystic fibrosis to a pet cat.

Chronic infection with Pseudomonas aeruginosa is common in cystic fibrosis (CF) and certain strains are more transmissible and virulent than others. Of these, the Liverpool Epidemic Strain (LES) is highly transmissible and cross infection has been reported between patients with CF and healthy non-CF relatives. However, the risk of transmission from humans to animals is unknown. The first report of interspecies transmission of the LES strain of P aeruginosa from an adult patient with CF to a pet cat is described. This development further complicates the issue of infection control policies required to prevent the spread of this organism.

Does breastfeeding method influence infant weight gain?

OBJECTIVE: To compare the effect of traditional and "baby-led" breastfeeding advice on early infant weight gain and exclusive breastfeeding rates. DESIGN: Longitudinal cohort study: part prospective, part retrospective. SETTING: One UK general practice. PARTICIPANTS: 63 exclusively breastfed infants in two cohorts: 32 babies born before and 31 babies born after a change in breastfeeding advice. INTERVENTION: A change from baby-led to traditional breastfeeding advice. MAIN OUTCOME MEASURES: Primary analysis: comparison of the effectiveness of the intervention (ie, weight gain expressed as standard deviation score gain (SDSG) between birth and 6-8 weeks) and exclusive breastfeeding rates between babies whose mothers received traditional advice and those whose mothers received baby-led advice. Secondary analysis: relevance of feed length (ie, weight gain expressed as SDSG between birth and 6-8 weeks in babies feeding for 10 min or less from the first breast and those feeding for longer than 10 min). RESULTS: The two groups were equivalent with respect to birth weight, gestational age, and parity. PRIMARY OUTCOME: babies whose mothers received the traditional advice were more likely to be exclusively breast fed up to 12 weeks (log rank chi2 = 9.68, p = 0.002) and gained more weight up to 6-8 weeks than those given baby-led advice (mean SDSG 0.41 (95% CI 0.13 to 0.69) vs -0.23 (95% CI -0.72 to 0.27)). Secondary outcome: irrespective of feeding advice given, babies feeding for 10 min or less from the first breast gained more weight by 6-8 weeks than babies feeding for longer than 10 min (mean SDSG 0.42 (95% CI 0.11 to 0.73) vs -0.19 (95% CI -0.64 to 0.26)). CONCLUSIONS: In this study, traditional breastfeeding advice resulted in increased weight gain and increased exclusive breastfeeding rates compared with baby-led advice. Exclusively breastfed babies who had shorter feeds (10 min or less from the first breast) gained more weight.

Environmental contamination with an epidemic strain of Pseudomonas aeruginosa in a Liverpool cystic fibrosis centre, and study of its survival on dry surfaces.

We conducted an environmental survey in the Liverpool adult cystic fibrosis (CF) centre in order to determine the extent of environmental contamination with an epidemic strain of Pseudomonas aeruginosa that colonizes most CF patients in Liverpool, and to identify possible reservoirs and routes of cross-infection. In addition, we studied the survival of this strain on dry surfaces, compared with that of other CF P. aeruginosa strains, to explore factors that might contribute to its high transmissibility. Samples were collected from staff, patients and the environment (drains, bath tubs, showers, dry surfaces, respiratory equipment and air) in the inpatient ward and outpatient clinic. P. aeruginosa strains were tested using a new polymerase chain reaction amplification assay specific for the Liverpool epidemic strain (LES). LES was isolated from patients' hands, clothes and bed linen. Environmental contamination with LES was only detected in close proximity to colonized patients (external surfaces of their respiratory equipment, and spirometry machine tubing and chair) and was short-lived. No persistent environmental reservoirs were found. LES was detected in the majority of air samples from inside patients' rooms, the ward corridor and the outpatient clinic. Survival of LES on dry surfaces was significantly longer than that for some other strains tested, but not compared with other strains shown not to be transmissible. Improved environmental survival on its own, therefore, cannot explain the high transmissibility of this epidemic strain. Our study suggests that airborne dissemination plays a significant role in patient-to-patient spread of LES, and confirms the need to segregate those patients colonized by epidemic P. aeruginosa strains from all other CF patients.

Renal impairment in cystic fibrosis patients due to repeated intravenous aminoglycoside use.

Although there are reports of cases of acute renal failure occurring in cystic fibrosis (CF) patients, usually in association with the use of nephrotoxic antibiotic therapy, there have been no studies of renal function in this patient group. We hypothesized that long-term use of intravenous (IV) nephrotoxic antibiotics (aminoglycosides and colistin sulphomethate) may contribute to renal disease in CF patients. In a prospective study, we assessed creatinine clearance as an index of renal function with two techniques (24-hr urine collections and the Cockroft-Gault formula) in a group of 80 stable adult CF outpatients chronically infected with Pseudomonas aeruginosa but with no history of preceding renal disease. Using a multiple linear regression model, we evaluated their renal function in terms of their lifetime IV use of aminoglycosides and colistin. Between 31% (Cockroft-Gault formula method) and 42% (24-hr urine collection method) of patients had a creatinine clearance below normal range. Using either method, there was a strong correlation between aminoglycoside use and diminishing renal function (r=- 0.32, P=0.0055), which was potentiated by the coadministration of colistin (r=- 0.42, P <0.0002). However, there was no correlation with colistin when used in combination with other antibiotics alone (r=0.18, P=NS). Repeated IV aminoglycoside use in CF is associated with long-term renal damage. Although this effect is potentiated by colistin, colistin on its own in moderate doses does not appear to be nephrotoxic. IV aminoglycosides should be used cautiously in CF patients, with regular monitoring of renal function.

Increased morbidity associated with chronic infection by an epidemic Pseudomonas aeruginosa strain in CF patients.

BACKGROUND: Chronic pulmonary infection with transmissible Pseudomonas aeruginosa strains in individuals with cystic fibrosis (CF) has been reported, raising issues of cross infection and patient segregation. The first such strain to be described (the Liverpool epidemic strain, LES) is now widespread in many UK CF centres. However, whether such infection carries a worse prognosis is unknown. To address this, the clinical course of a group of CF patients chronically infected by LES was compared with that in patients harbouring unique strains. METHODS: Using P aeruginosa strain genotyping, two cohorts of CF patients attending the Liverpool CF service were identified who were LES positive or negative in 1998 and remained so until 2002. From these, two groups of 12 patients were matched in 1998 for age, spirometric parameters, and nutritional state and their clinical course was followed for 5 years. Patients chronically infected with Burkholderia cepacia were excluded. RESULTS: Patients chronically infected with LES had a greater annual loss of lung function than those not chronically infected by LES (mean difference between groups -4.4% (95% CI -8.1 to -0.9; p<0.02)), and by 2002 their percentage predicted forced expiratory volume in 1 second (FEV1) was worse (mean 65.0% v 82.6%, p<0.03). Their nutritional state also deteriorated over the study period (mean difference between groups in body mass index -0.7 (95% CI -1.2 to -0.2; p<0.01)), such that by 2002 they were malnourished compared with LES negative patients (mean BMI 19.4 v 22.7, p<0.02). CONCLUSIONS: Chronic infection with the Liverpool epidemic P aeruginosa strain in CF patients confers a worse prognosis than infection with unique strains alone, confirming the need for patient segregation. Since this strain is common in many CF units, strain identification in all CF centres is essential. This can only be carried out using genomic typing methods.

Bronchoscopic insertion of Gianturco stents for the palliation of malignant lung disease: 10 year experience.

Malignant large airway obstruction is life threatening and may not be amenable to urgent radiotherapy. Palliative airway stenting is difficult and traditionally carried out under general anaesthesia and fluoroscopy. We have shown that self expanding Gianturco metal stents can be placed under local anaesthesia using fibreoptic bronchoscopy and direct vision for the treatment of malignant airway tumours, and report our 10 year experience. All referrals for stenting referred to our unit between 1990 and 1999 were included, looking for histological type, number and site of stents, complications of the procedure, other interventions, and survival. One hundred and sixty two patients (average age 64 years, (range 21-89)) had 307 stents inserted during 167 procedures (144 primary lung tumours, 18 secondary malignancy). There were no operative deaths, but three patients developed a pneumothorax, one requiring intercostal drain insertion. Average survival following stent insertion was less for primary lung cancer than for secondary disease (103 vs. 431 days, P<0.001). There were no excess complications in a subgroup of 64 patients treated locally by oncologists, even when stenting was the primary procedure. This technique is useful in palliating life threatening airway obstruction, particularly for secondary cancer, and can be used in any centre undertaking fibreoptic bronchoscopy.

Bacterial diversity in cases of lung infection in cystic fibrosis patients: 16S ribosomal DNA (rDNA) length heterogeneity PCR and 16S rDNA terminal restriction fragment length polymorphism profiling.

The leading cause of morbidity and mortality in cystic fibrosis (CF) patients stems from repeated bacterial respiratory infections. Many bacterial species have been cultured from CF specimens and so are associated with lung disease. Despite this, much remains to be determined. In the present study, we characterized without prior cultivation the total bacterial community present in specimens taken from adult CF patients, extracting DNA directly from 14 bronchoscopy or sputum samples. Bacterial 16S ribosomal DNA (rRNA) gene PCR products were amplified from extracted nucleic acids, with analyses by terminal restriction fragment length polymorphism (T-RFLP), length heterogeneity PCR (LH-PCR), and sequencing of individual cloned PCR products to characterize these communities. Using the same loading of PCR products, 12 distinct T-RFLP profiles were identified that had between 3 and 32 T-RFLP bands. Nine distinct LH-PCR profiles were identified containing between one and four bands. T-RFLP bands were detected in certain samples at positions that corresponded to pathogens cultured from CF samples, e.g., Burkholderia cepacia and Haemophilus influenzae. In every sample studied, one T-RFLP band was identified that corresponded to that produced by Pseudomonas aeruginosa. A total of 103 16S rRNA gene clones were examined from five patients. P. aeruginosa was the most commonly identified species (59% of clones). Stenotrophomonas species were also common, with eight other (typically anaerobic) bacterial species identified within the remaining 17 clones. In conclusion, T-RFLP analysis coupled with 16S rRNA gene sequencing is a powerful means of analyzing the composition and diversity of the bacterial community in specimens sampled from CF patients.

Intratracheal cocaine induced myocardial infarction: an unusual complication of fibreoptic bronchoscopy.

A 73 year old man developed chest pains 5 minutes after fibreoptic bronchoscopy. The procedure had been performed without sedation following an intratracheal injection of 5 ml 2.5% cocaine solution and xylocaine spray to the pharynx for topical anaesthesia. A 12-lead electrocardiogram showed an evolving anterior myocardial infarction. Cardiac catheterisation revealed coronary artery spasm in the proximal left anterior descending artery at the site of non-significant plaque disease. The risk factors, mechanisms, and treatment of cocaine induced myocardial infarction following intratracheal injections are discussed.

Fosfomycin therapy for multiresistant Pseudomonas aeruginosa in cystic fibrosis.

BACKGROUND: Increasing resistance to standard antibiotics has been demonstrated in CF patients colonised by Pseudomonas aeruginosa. The antibiotic Fosfomycin has a unique mode of action against this organism, and may protect against aminoglycoside mediated renal and ototoxic effects. However, there is little published experience of this drug in IV form, and it is not licensed for use in the UK. METHODS: In combination with other antibiotics, we used Fosfomycin to treat 30 pulmonary exacerbations in 15 adult CF patients colonised by P. aeruginosa, mainly multiresistant strains. All patients gave informed consent. We cultured sputum prior to treatment and measured spirometry, renal function, and symptoms before and after treatment, and recorded any side effects. RESULTS: One patient developed nausea and Fosfomycin treatment was withdrawn. The remaining patients showed clinical resolution of their chest exacerbations (mean FEV1% predicted: pre 41.1 vs. post 49.4, P<0.001). Although there was a statistical increase in plasma urea (pre 3.9 mmol/l vs. post 4.3, P<0.03), this was still within the normal range. Plasma creatinine was unchanged. CONCLUSIONS: This study shows that IV Fosfomycin is well tolerated by adult patients with CF and can be useful in the treatment of those colonised with multiresistant P. aeruginosa.

Spread of an epidemic Pseudomonas aeruginosa strain from a patient with cystic fibrosis (CF) to non-CF relatives.

Colonisation with Pseudomonas aeruginosa is common in adults with cystic fibrosis (CF) and there is increasing evidence that transmissible strains may cross colonise patients. However, transmission of these strains by social contact to healthy non-CF individuals has not been described. A case is presented where an adult CF patient colonised by an epidemic P aeruginosa strain infected her parents with subsequent morbidity.

Outcome of Burkholderia cepacia colonisation in an adult cystic fibrosis centre.

BACKGROUND: Colonisation with Burkholderia cepacia is a poor prognostic indicator in subjects with cystic fibrosis (CF), but outcome prediction is impossible since patients are colonised by different strains with differing pathogenicity. The clinical course of a large cohort of CF patients colonised with UK epidemic (ET12) B cepacia was followed for 5 years and compared with that of the remaining patients in the clinic. METHODS: Pulmonary function, nutritional state, and lung pathogen colonisation were recorded for 5 years before December 1997 or death for all 107 patients who had attended the Liverpool adult CF clinic since 1993. For each patient a time line from study entry to date of death or 1997 was constructed. In 1993 potential risk factors including age and sex were subjected to Cox proportional hazards analysis using the end point of mortality as the outcome variable. The analysis was supplemented by time varying covariables that described the change in FEV(1), BMI, and colonisation status across time, and the excess risk associated with B cepacia colonisation was calculated. Subsequently, in those patients who died between 1993 and 1997, predictive factors for death were compared within groups using complete 5 year data. RESULTS: Thirty seven patients had been colonised by epidemic B cepacia and these patients had four times the mortality of the remainder (p<0.01). In 1993 univariate predictors of mortality were age (alive 19.6 (0.64) v dead 23.8 (1.44); p<0.005) and baseline FEV(1) (alive 68.6 (2.5)% predicted v dead 43.2 (4.8)%; p<0.001) with a trend for BMI (p=0.07). However, following time varying covariate Cox proportional hazards analysis, only lower FEV(1) (hazards ratio 1.1, 95% confidence limits 1.06 to 1.14; p<0.001) and colonisation with B cepacia (hazards ratio 7.92, confidence limits 2.65 to 23.69; p<0.001) were identified as significant factors for death. Surviving B cepacia patients had similar initial lung function to the remaining surviving patients but had an accelerated loss of lung function over the study period (colonised -1.9% predicted per year v non-colonised -0.3% predicted per year; p<0.05). Deceased patients colonised with B cepacia had better spirometric results than the remaining deceased patients 5 years before death (p<0.05) but lost lung function at a greater rate than non-colonised patients (colonised -6.2% predicted per year v non-colonised -1.9% predicted per year; p<0.05). CONCLUSIONS: This study confirms the excess mortality associated with epidemic B cepacia colonisation and shows that those with poor spirometric values are at the greatest risk.

Superinfection with a transmissible strain of Pseudomonas aeruginosa in adults with cystic fibrosis chronically colonised by P aeruginosa.

Infection with transmissible strains of Pseudomonas aeruginosa can occur in uncolonised patients, but cross infection (superinfection) of patients already colonised withP aeruginosa has not been reported. With genotypic identification, we found superinfection by a multiresistant transmissible strain of P aeruginosa in four patients with cystic fibrosis (CF) who were already colonised by unique strains of P aeruginosa. No evidence of environmental contamination was found, but all patients became superinfected after contact with colonised individuals during inpatient stays. Inpatients with CF who are colonised with P aeruginosa should be separated by strain type. Such strain typing can only be reliably done by genomic methods, but this has resource implications.

Cancer-specific genomic instability in bronchial lavage: a molecular tool for lung cancer detection.

We examined genomic instability in DNA from 80 bronchial lavage samples from patients with lung cancer and individuals with no malignant lung disease. We used a multiplex assay of eight fluorescent-tagged microsatellite markers that have a very high incidence of allelic imbalance in lung tumors. When genomic instability at individual loci was analyzed statistically against diagnosis, markers D3S1289 (P = 0.033), D3S1300 (P = 0.001), D13S171 (P = 0.009), and D17S2179E (P = 0.017) demonstrated significantly higher frequency of instability in bronchial lavage specimens from lung cancer cases than those with nonmalignant conditions. In contrast, markers D9S157, D9S161, D13S153, and D5S644 demonstrated lower specificity (P > 0.05) for lung tumors. These results suggest that genomic instability in some loci may be related to high proliferation rates but not necessarily to cell commitment to malignancy. When genomic instability was scored with only the four cancer-specific markers, the assay produced a sensitivity of 73.9% and a specificity of 76.5%. On combining the results from the cytological examination and the molecular assay, the sensitivity reached 82.6%. These results indicate that in our efforts to investigate genomic instability as a potential marker for the early detection of lung cancer, we need to identify cancer-specific genomic instability markers. This paper has shown that these first four markers may be considered to form an individual set of cancer-specific genomic instability markers.