Predation of the newly invasive pest Megacopta cribraria (Hemiptera: Plataspidae) in soybean habitats adjacent to cotton by a complex of predators.

The kudzu bug, Megacopta cribraria (F.) (Hemiptera: Plataspidae),is a newly invasive exotic insect found primarily on kudzu, but also on soybean, in the southeastern United States. We used molecular gut-content analysis to document predation on this pest by insects and spiders in soybean, and to detect remains of crop-specific alternative prey in predators' guts as markers of predator migration between soybean and adjacent cotton. M. cribraria was found exclusively on soybean. Eight native generalist predators over both crops screened positive by specific PCR for DNA of the pest: Geocoris punctipes (Say), Geocoris uliginosus (Say), Orius insidiosus (Say), Podisus maculicentris (Say), Hippodamia convergens Guérin-Méneville, Zelus renardii (Kolenati), Oxyopes salticus Hentz, and Peucetia viridans (Hentz); a ninth predator, the exotic Solenopsis invicta Buren, also screened positive for M. cribraria DNA. P. viridans was the only arthropod that tested positive for DNA of this invasive pest in only one crop, cotton. Two plant-feeding pentatomid species, Piezodorus guildinii (Westwood) and Thyanta custator (F.), were found exclusively on soybean, and another, Euschistus tristigmus (Say), was specific to cotton in the context of this study. Detection of predation on a combination of M. cribraria and P. guildinii and T. custator in cotton and M. cribraria and E. tristigmus in soybean demonstrated that these predators dispersed between crops. These results strongly support the use of soybean habitats adjacent to cotton as part of a conservation biological control strategy against M. cribraria. This is the first report documenting predation on this exotic pest in the field via molecular gut-content analysis.

Spontaneous pneumomediastinum: a rare complication of bronchial asthma.

Pneumomediastinum is a rare complication of an acute exacerbation of asthma. We describe a 28-year-old female who was admitted to hospital with acute severe exacerbation of asthma and developed a spontaneous pneumomediastinum (SPM) with associated subcutaneous emphysema. She was successfully managed conservatively. On follow up there was resolution of the subcutaneous emphysema and the pneumomediastinum, clinically and radiologically. SPM although usually a self-limiting condition, can occasionally be life threatening. Therefore, it is important to raise the awareness of this potential complication of asthma.

Use of a screening tool for detection of sleep-disordered breathing.

BACKGROUND: Sleep apnoea, whether obstructive or central, is usually diagnosed by polysomnography. A simpler tool for screening high risk populations may be of value. METHODS: We compared a portable device using nasal pressure cannulae and a high-sensitivity pressure sensor (the ApneaLink) with our standard polysomnography technique for diagnosing sleep apnoea (using the Embletta device), in 67 patients being investigated for possible sleep apnoea. The patients' average age was 52.6, 79 per cent were male, the mean body mass index was 32.3, and the mean Epworth sleepiness score was 13.0. RESULTS: Twenty-five patients (45 per cent) were identified as having an apnoea-hypopnoea index of >15, as measured by the Embletta. The mean (standard deviation) apnoea-hypopnoea index was 21.5 +/- 23.0 as measured by the Embletta and 24.3 +/- 26.2 as measured by the ApneaLink. The sensitivity of the ApneaLink for an apnoea-hypopnoea index cut-off point of 15 was 92 per cent and the specificity was 96.7 per cent. The negative predictive value of the ApneaLink for an apnoea-hypopnoea index of < or = 15 was 94 per cent. CONCLUSIONS: The ApneaLink is a useful tool for screening patients thought to have possible sleep apnoea, and for selecting patients for definitive diagnostic testing.

Quality of life measurements and bronchodilator responsiveness in prescribing nebulizer therapy in COPD.

Nebulized bronchodilators are widely regarded as the optimal treatment for maintenance therapy in patients with severe chronic obstructive pulmonary disease (COPD). The aim of the study was to assess whether detailed physiological, functional and quality of life-related measurements can assist in determining the requirement for nebulized bronchodilator therapy in patients with moderate to severe COPD. This was an unblinded, randomized, crossover study that compared intermediate (120 mcg ipratropium bromide and 600 mcg of salbutamol using metered dose inhaler (MDI) and spacer) and high dose (nebulized 500 mcg ipratropium bromide and 2.5 mg salbutamol) bronchodilator therapy, on physiological, functional and quality of life-related measurements in patients with COPD. A total of 25 patients (12 female), mean (SD) age 68 (7) years, FEV(1) 45 (10) % predicted completed the study. There was no statistically significant difference between the treatments in the pre- and post-bronchodilator lung function values, six-minute walk distance, breathlessness score or quality of life questionnaires. Fifteen patients preferred bronchodilator therapy with nebulizer and 10 with MDI and spacer. In 20 patients at least one positive response in quality of life score, lung function or six-minute walk, was observed on the preferred treatment. Only a proportion of patients with moderate or severe COPD prefer nebulized bronchodilator therapy. This study found that none of the parameters singly or in combination were consistently predictive of patients' preference for nebulized bronchodilator therapy. Therefore, we suggest that clinicians institute a trial of stepping up to an intermediate dose of bronchodilators prior to introducing nebulized therapy.

Feeding mode and prey detectability half-lives in molecular gut-content analysis: an example with two predators of the Colorado potato beetle.

The time during which prey remains are detectable in the gut of a predator is an important consideration in the interpretation of molecular gut-content data, because predators with longer detectability times may appear on the basis of unweighted data to be disproportionately important agents of prey population suppression. The rate of decay in detectability, typically expressed as the half-life, depends on many variables; one that has not been explicitly examined is the manner in which the predator processes prey items. The influence of differences in feeding mode and digestive physiology on the half-life of DNA for a single prey species, the Colorado potato beetle Leptinotarsa decemlineata (Say), is examined in two predators that differ dramatically in these attributes: the pink ladybeetle, Coleomegilla maculata (DeGeer), which feeds by chewing and then ingesting the macerated material into the gut for digestion; and the spined soldier bug, Podisus maculiventris (Say), which physically and enzymatically processes the prey extra-orally before ingestion and further digestion in the gut. In order to standardize the amount of DNA consumed per predator, a single L. decemlineata egg was used as the prey item; all predators were third instars. The PCR assay yields estimated prey DNA half-lives, for animals maintained under field temperatures, of 7.0 h in C. maculata and 50.9 h in P. maculiventris. The difference in the prey DNA half-lives from these two predators underscores the need to determine detectabilities from assemblages of predators differing in feeding mode and digestive physiology, in order to weight positives properly, and hence determine the predators' relative impacts on prey population suppression.

Prolonged antibiotics for purulent bronchiectasis in children and adults.

BACKGROUND: The vicious cycle hypothesis for bronchiectasis predicts that bacterial colonisation of the respiratory tract perpetuates inflammatory change. This damages the mucociliary escalator preventing bacterial clearance and allowing the persistence of pro-inflammatory mediators. Conventional treatment with physiotherapy and intermittent antibiotics are felt to improve the condition of bronchiectasis patients although there are no conclusive data showing that these interventions influence the natural history of the condition. Various strategies have been tried to interrupt this cycle of infection and inflammation and one of these is to prolong antibiotic treatment in the hope of allowing the airway mucosa to heal. OBJECTIVES: This systematic review brings together the evidence and where possible presents a meta-analysis of the data available to answer the question 'Does treatment with prolonged courses of antibiotics influence the outcome in purulent bronchiectasis?' SEARCH STRATEGY: The Cochrane Airways Group trials register and reference lists of identified articles were searched. Searches were current as of January 2007. SELECTION CRITERIA: Randomised trials looking at the use of prolonged antibiotic therapy in the treatment of bronchiectasis compared with either placebo or usual care. DATA COLLECTION AND ANALYSIS: Trial quality was assessed and data extraction was carried out by the reviewers independently. Study authors were contacted for missing information. MAIN RESULTS: Nine trials met the inclusion criteria, recruiting a total of 378 participants. Antibiotics were given for between 4 weeks and one year. Only limited meta-analysis was possible due to the diversity of outcomes in the trials. Response rates showed significant effects in favour of prolonged antibiotic treatment (Peto OR (95% CI), 3.37 (1.60 to 7.09)). Conversely for exacerbation rates there was no significant difference between prolonged antibiotics and placebo (Peto OR (95% CI), 0.96 (0.27 to 3.46)). For withdrawals there was no significant difference between treatment and placebo management (Peto OR (95% CI), 1.06 (0.42 to 2.65)). Data for lung function showed no significant benefit in favour of antibiotic treatment (% predicted FEV1 mean difference -1.05 % (95% CI -6.93 to 4.83)). AUTHORS' CONCLUSIONS: The evidence available shows a small benefit for the use of prolonged antibiotics in the treatment of bronchiectasis. This review is limited by the diversity of the trials. Further randomised controlled trials with adequate power and standardised end points are required.

Inhaled hyperosmolar agents for bronchiectasis.

BACKGROUND: Mucus retention in the lungs is a prominent feature of bronchiectasis. The stagnant mucus becomes chronically colonised with bacteria, which elicit a host neutrophilic response. This fails to eliminate the bacteria, and the large concentration of host-derived protease may contribute to the airway damage. The sensation of retained mucus is itself a cause of suffering, and the failure to maintain airway sterility probably contributes to the frequent respiratory infections experienced by many patients. Hypertonic saline inhalation is known to accelerate tracheobronchial clearance in many conditions, probably by inducing a liquid flux into the airway surface, which alters mucus rheology in a way favourable to mucociliary clearance. Inhaled dry powder mannitol has a similar effect. Such agents are an attractive approach to the problem of mucostasis, and deserve further clinical evaluation. OBJECTIVES: To determine whether inhaled hyperosmolar substances are efficacious in the treatment of bronchiectasis SEARCH STRATEGY: The Cochrane Airways Group Specialised Register was searched, and leaders in the field were contacted. Searches were current as of October 2005. Search updates will be run annually. SELECTION CRITERIA: Any trial using hyperosmolar inhalation in patients with bronchiectasis not caused by cystic fibrosis. DATA COLLECTION AND ANALYSIS: Two reviewers assessed studies for suitability. MAIN RESULTS: Two small studies met the inclusion criteria of the review (28 participants). One study reported tracheobronchial clearance of a particulate radio aerosol after inhalation of dry mannitol on a single occasion, with appropriate control. Airway clearance doubled in the central and intermediate regions of the lung, but not in the peripheral region, after mannitol administration. No side effects were observed, but two patients were premedicated with nedocromil to prevent bronchospasm. Findings from one further trial indicated that one domain of a sensitive health status instrument showed a favourable response to mannitol. AUTHORS' CONCLUSIONS: Dry powder mannitol has been shown to improve tracheobronchial clearance in bronchiectasis, as well as cystic fibrosis, asthmatics, and normal subjects. Hypertonic saline has not been specifically tested in bronchiectasis, but improves clearance in these other conditions and in chronic bronchitis. The measurement of health status in one of the studies should be repeated in future longer term randomised controlled studies of mannitol and hypertonic saline. Consideration should also be given to exacerbations and symptom scores, as well as drug-related adverse events.

Molecular methods for assessing insect parasitism.

Determining insect parasitism rates is problematic due to the small size and lack of useful distinguishing morphological characters of many parasitoid taxa. To solve this problem, entomologists have employed one of four general methods to detect parasitoid protein or nucleic acid markers: serological assay; random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR); allozyme electrophoresis; or specific PCR. Serological methods, especially with monoclonal antibodies, are unrivalled for specificity, enabling discrimination at the stage as well as species level. However, they have not found favour with many workers, possibly due to complexity and expense. RAPD-PCR has been widely used, but can only be recommended for restricted applications because of its poor reproducibility. Allozyme electrophoresis provides reproducible detection and discrimination of closely related species. Specific-PCR is highly specific and reproducible, and also has the shortest latency for detection, usually 24 h or less after parasitization. The substantial existing literature on allozyme electrophoresis and specific PCR is used to support recommendations on what are apt to be fruitful enzyme systems or genomic regions for detecting and discriminating parasitoids in untried parasitoid-host assemblages.

Barcoding generalist predators by polymerase chain reaction: carabids and spiders.

Identification of arthropod predators is challenging when closely related species are found at a given locality. Identification of the immature stages is especially problematic, because distinguishing morphological features are difficult to use or have not been described. We used polymerase chain reaction (PCR) to distinguish closely related carabids and spiders, and to match eggs and larvae (or nymphs) with identified adult parents. Within the Carabidae, we amplified species-specific mitochondrial cytochrome oxidase I (COI) fragments for three species each in the genera Poecilus and Harpalus, and two each in Chlaenius and Bembidion. Within the Araneae, we amplified species-specific COI fragments for two Hibana species (Anyphaenidae), Pardosa milvina and Rabidosa rabida (Lycosidae), Frontinella communis and Grammonota texana (Linyphiidae), and Cheiracanthium inclusum (Miturgidae). We are able to correctly identify all immature stages tested--eggs, larvae (or nymphs) and pupae--by comparison of the amplified fragments with those of the adults. Using COI markers as species identifiers is a tenet of the Barcode of Life initiative, an international consortium to provide a molecular identifier for every animal species.

Prolonged antibiotics for purulent bronchiectasis.

BACKGROUND: The vicious cycle hypothesis for bronchiectasis predicts that bacterial colonisation of the respiratory tract perpetuates inflammatory change. This damages the mucociliary escalator preventing bacterial clearance and allowing the persistence of pro-inflammatory mediators. Conventional treatment with physiotherapy and intermittent antibiotics are felt to improve the condition of bronchiectasis patients although there are no conclusive data showing that these interventions influence the natural history of the condition. Various strategies have been tried to interrupt this cycle of infection and inflammation and one of these is to prolong antibiotic treatment in the hope of allowing the airway mucosa to heal. OBJECTIVES: This systematic review brings together the evidence and where possible presents a meta-analysis of the data available to answer the question 'Does treatment with prolonged courses of antibiotics influence the outcome in purulent bronchiectasis?' SEARCH STRATEGY: The Cochrane Airways Group trials register and reference lists of identified articles were searched. SELECTION CRITERIA: Randomised trials looking at the use of prolonged antibiotic therapy in the treatment of bronchiectasis. DATA COLLECTION AND ANALYSIS: Trial quality was assessed and data extraction was carried out by the reviewers independently. Study authors were contacted for missing information. MAIN RESULTS: 447 abstracts were found and reviewed for suitability. Six trials were included and 302 patients were randomised amongst these trials. 40% of the patients were contributed by one trial. Antibiotics were given for between 4 weeks and one year. There were 40 withdrawals due to treatment failure and intolerable side effects. Only limited meta-analysis was possible due to the diversity of the trials. Response rates showed significant effects in favour of prolonged antibiotic treatment (Peto OR (95% CI), 3.37 (1.60 to 7.09)). Conversely for exacerbation rates there was no significant difference between prolonged antibiotics and placebo (Peto OR (95% CI), 0.96 (0.27 to 3.46)). For withdrawals there was no significant difference between treatment and placebo management (Peto OR (95% CI), 1.06 (0.42 to 2.65)). Data for lung function showed no significant benefit in favour of antibiotic treatment (% predicted FEV1, WMD (95% CI) -1.05 (-6.93 to 4.83)). REVIEWER'S CONCLUSIONS: The evidence available shows a small benefit for the use of prolonged antibiotics in the treatment of bronchiectasis. This review is limited by the diversity of the trials. Further randomised controlled trials with adequate power and standardised end points are required.

Hospital at home for acute exacerbations of chronic obstructive pulmonary disease.

BACKGROUND: Hospital at home schemes are a recently adopted method of service delivery for the management of acute exacerbations of chronic obstructive pulmonary disease aimed at reducing demand for acute hospital in-patient beds and promoting a patient centered approach through admission avoidance. However, evidence in support of such a service is contradictory. OBJECTIVES: To evaluate the efficacy of "hospital at home" compared to hospital inpatient care in acute exacerbations of chronic obstructive pulmonary disease. SEARCH STRATEGY: The Cochrane Central Register of Controlled Trials; electronically available databases e.g. MEDLINE (1966-current), EMBASE (1980-current), PubMed, ClincalTrials, Science Citation Index and on-line individual respiratory journals; bibliographies of included trials were all searched and contact with authors was made to obtain studies. The most recent searches were carried out in August 2003. SELECTION CRITERIA: Only randomised controlled trials were considered where patients presented to the emergency department with an exacerbation of their chronic obstructive pulmonary disease. Studies must not have recruited patients that are usually deemed obligatory admissions. DATA COLLECTION AND ANALYSIS: Two reviewers independently selected articles for inclusion, evaluated methodological quality of the studies and abstracted data. MAIN RESULTS: Seven studies with 754 patients were included in the review. Studies provided data on hospital readmission and mortality both of which were not significantly different when the two study groups were compared (RR 0.89; 95%CI 0.72 to 1.12 & RR 0.61; 95%CI 0.36 to 1.05, respectively). Both the patients and the carers preferred hospital at home schemes to inpatient care (RR 1.53; 95%CI 1.23 to 1.90). Other reported outcomes included few studies. REVIEWER'S CONCLUSIONS: This review has shown that one in four carefully selected patients presenting to hospital emergency departments with acute exacerbations of chronic obstructive pulmonary disease can be safely and successfully treated at home with support from respiratory nurses. This review found no evidence of significant differences between "hospital at home" patients and hospital inpatients for readmission rates and mortality at two to three months after the initial exacerbation. Both the patients and carers preferred "hospital at home" schemes to inpatient care.

Short acting beta-2 agonists for bronchiectasis.

BACKGROUND: Bronchiectasis is a condition characterized by an abnormal and irreversible dilatation of the sub segmental airways and it may be caused by a variety of disease processes. Currently medical treatment includes physiotherapy, antibiotics and occasionally mucolytics. Many people with bronchiectasis receive bronchodilator therapy, since many people with the condition show signs of airflow obstruction and bronchial hyper-responsiveness. Evidence on effectiveness of bronchodilator therapy in bronchiectasis has only recently started to be systematically studied. OBJECTIVES: The present review examined the effectiveness of short acting beta-2 agonist therapy in bronchiectasis, as this is the most frequently used treatment for airflow obstruction in people with this condition. SEARCH STRATEGY: We systematically searched four databases: CENTRAL (Issue 2, 2002); MEDLINE (1966 to September 2002); EMBASE (1980 to September 2002); and CINAHL (1982 to September 2002). We also checked bibliographies of all identified RCTs to identify potentially relevant citations. SELECTION CRITERIA: All randomised controlled trials were considered for inclusion, whether single or double blind. The control group was placebo/no treatment or other drug/physical therapy. Participants could be children or adults diagnosed with bronchiectasis by plain-film chest radiograph, bronchography or high resolution computerized tomography. Patients were excluded if they had cystic fibrosis. Any type of short acting beta-2 agonist administered by inhalation or systemic route, used in conjunction with conventional treatment was included. DATA COLLECTION AND ANALYSIS: In the absence of any relevant RCTs, we were unable to extract or analyse data. MAIN RESULTS: We identified 48 articles by the search, the majority of which could be excluded on the basis of the abstract as they were not RCTs. Six articles were retrieved and were all excluded after careful consideration because they were either not RCTs or they did not deal with the question of interest. REVIEWER'S CONCLUSIONS: We failed to identify any RCTs investigating the role of short acting beta agonists in bronchiectasis. Since short acting beta-2 agonist therapy is the most frequently used treatment for airflow obstruction in bronchiectasis, there appears to be the need to investigate the effectiveness of this therapy using an RCT.

Long-term antibiotics in the management of non-CF bronchiectasis--do they improve outcome?

In addition to bacteria and inflammatory cells, the sputum of patients with bronchiectasis contains mediators that damage the airway epithelium and promote inflammatory change. The deleterious effects of these mediators, such as neutrophil elastase, reduce host defences and consequently perpetuate the propensity to recurrent infection. This 'vicious cycle' of infection and inflammation in bronchiectasis suggests that long-term antibiotic therapy might be beneficial in these patients by reducing microbial load and, in doing so, inhibit inflammation in the lung allowing tissue repair to occur. Short courses of antibiotics achieve clinical improvements and also have been shown to reduce the levels of harmful mediators in the sputum. This article will cite the studies reported for long-term antibiotic treatment in bronchiectasis and overall there seems to be benefits for patients with chronic sputum purulence. The evidence that supports the postulated pathological mechanisms will also be discussed. Important issues in clinical practice such as the usefulness of antibiotic sensitivities, the evolution of resistance patterns, and drug delivery will also be discussed.

Doxapram for ventilatory failure due to exacerbations of chronic obstructive pulmonary disease.

BACKGROUND: COPD is a progressive illness and in the later stages, exacerbations may lead to ventilatory failure. The combination of hypoxia and hypercapnia can lead to coma and death. Correction of these blood gas abnormalities is a medical emergency. Doxapram is a respiratory stimulant used to stimulate respiration in this setting. OBJECTIVES: The objective of this review was to assess the effects of doxapram on gas exchange and clinical outcomes in people with ventilatory failure due to acute exacerbations of chronic obstructive pulmonary disease. SEARCH STRATEGY: We searched the Cochrane Airways Group trials register and reference lists of articles. We also contacted experts in the field, study authors and drug companies. Following electronic searches conducted in November 2001 one further unpublished study has been included in the review. SELECTION CRITERIA: Randomised trials comparing doxapram with other treatments or placebo in people with ventilatory failure due to exacerbations of chronic obstructive pulmonary disease. DATA COLLECTION AND ANALYSIS: One reviewer assessed trial quality and extracted data. MAIN RESULTS: Four trials involving 176 people were included. The trials were of variable quality. Doxapram was marginally superior to placebo in preventing blood gas deterioration. In the two studies comparing doxapram and non-invasive ventilation the results were conflicting: an early small study suggested non-invasive ventilation was superior. However, a subsequent larger study in severe participants suggested doxapram was equally effective in terms of blood gases changes, with no differences observed in mortality and frequent treatment failure. REVIEWER'S CONCLUSIONS: Doxapram can improve blood gas exchange over the first few hours of treatment. Newer techniques such as non-invasive ventilation may prove to be more effective, although there is no randomised trial evidence to this effect.