Zero the hero: Evidence for involvement of the ventromedial prefrontal cortex in affective bias for free items

Recent evidence from psycho-economics shows that when the price of an item decreases to the extent that it becomes available for free, one can observe a remarkable increase of subjective utility toward this item. This phenomenon, which is not observed for any other price but zero, has been termed the zero-price effect (ZPE). The ZPE is attributed to an affective heuristic where the positive affect elicited by the free status of an item provides a mental shortcut biasing choice towards that item. Given that the ZPE relies on affective processing, a key role of the ventromedial prefrontal cortex (vmPFC) has been proposed, yet neuroscientific studies of the ZPE remain scarce. This study aimed to explore the role of the vmPFC in the ZPE using a novel, within-subject assessment in participants with either an acquired (lesion patients) or degenerative (behavioural-variant frontotemporal dementia patients) lesion of the vmPFC, and age-matched healthy controls. All participants were asked to make a series of choices between pairs of items that varied in price. One choice trial involved an equal decrease of both item prices, such that one of the items was priced zero. In contrast to controls, patients with both vmPFC-lesion and behavioural-variant frontotemporal dementia showed marked reductions in zero-related changes of preference in pairs of gift-cards, but not for pairs of food items. Our findings suggest that affective evaluations driving the ZPE are altered in patients with focal or degenerative damage to the vmPFC. This supports the notion of a key role of the vmPFC in the ZPE and, more generally, the importance of this region in value-based affective decision-making. Our findings also highlight the potential utility of affective heuristic tasks in future clinical assessments.

COVID-19: Extensive epithelial damage and ciliary dyskinesia in hospitalised patients

Infection with SARS-CoV-2 can cause severe respiratory disease and it is predicted that the COVID-19 pandemic will leave a substantial number of patients with long-term respiratory complications (1).

Promoting the get healthy information and coaching service (GHS) in Australian-Chinese communities: facilitators and barriers

Obesity and being overweight are major public health concerns that health coaching can assist people to manage through encouraging self-management and behaviour change. The Get Healthy Information and Coaching Service (GHS) is a telephone health coaching service in Australia that has effectively improved the health of the general population but has had less participation of culturally and linguistically diverse (CALD) populations. The Chinese population is the largest migrant group in Australia with increased risk of diabetes but had reduced access to the GHS program due to communication barriers. The GHS developed a pilot program for Chinese (Mandarin and Cantonese-speaking) communities using bilingual coaches and translated material to address these barriers. Qualitative research was undertaken with Chinese stakeholders (14 interviews) and 11 program participants from the group which had completed the program (2 focus groups in Mandarin and Cantonese) to understand their experiences and the success of promotional activities. This research does not contain the experiences of the people that withdrew from the program. The bilingual program was culturally and linguistically appropriate and addressed risk factors for chronic conditions. Participants formed positive relationships with bilingual coaches who they preferred to interpreters. They felt the program promoted healthy eating, weight and physical activity. Although Chinese stakeholders had concerns about participants' ability to goal set, participants said they met their health goals and were committed to the GHS program. Strategies to enhance the program included promoting the bilingual GHS to the communities and stakeholders. Factors to consider beyond language in adapting the program to the Australian Chinese communities include meeting the heterogenous needs of the older population, ensuring community engagement and addressing cultural beliefs and practices.

326 Student Perceptions of Neurosurgery: Evaluating the Role of Undergraduate Neuroscience Societies

Introduction

Many institutions lack an organized system of informal network for medical students wishing to explore neurosurgery. We sought to evaluate the role of extracurricular neurosurgical events in influencing student perceptions of neurosurgery.

Method

Participants for this study were recruited from a neurosurgical careers seminar and practical workshop. Responses were collected prospectively using a multi-method strategy consisting of closed and open-ended questions. Additionally, semi-structured interviews were conducted to gain a deeper insight of students’ evaluation of these events and their perceptions of neurosurgery.

Results

A total of 124 students attended our extracurricular neurosurgery events. These events showed benefits in clinical knowledge and career planning. Students perceived the practical workshops to be useful in improving their basic surgical skills. Semi-structured interviews revealed that students felt their opportunities in exploring clinical neurosciences to be limited, which was seen as contributing towards the wider culture of neurophobia.

Conclusions

Undergraduate neuroscience societies provide useful educational platforms for students interested in neurosurgery, even in regions lacking institutional neuroscience networks. To help mitigate the wider culture of neurophobia, undergraduate neuroscience societies should focus on non-academic aspects of neurosurgery that are more personal and engaging, in an effort to spark interest in those who have had little exposure to the specialty.

Hypertension as a predictor of advanced colorectal cancer outcome and cetuximab treatment response

Background

Adrenergic receptor stimulation is involved in the development of hypertension (htn) and has been implicated in cancer progression and dissemination of metastases in various tumours, including colon cancer. Adrenergic antagonists such as beta-blockers (bbs) demonstrate inhibition of invasion and migration in colon cancer cell lines and have been associated with decreased mortality in colorectal cancer (crc). We examined the association of baseline htn and bb use with overall (os) and progression-free survival (pfs) in patients with pretreated, chemotherapy refractory, metastatic crc (mcrc). We also examined baseline htn as a predictor of cetuximab efficacy.

Methods

Using data from the Canadian Cancer Trials Group co.17 study [cetuximab vs. best supportive care (bsc)], we coded baseline htn and use of anti-htn medications, including bbs, for 572 patients. The chi-square test was used to assess the associations between those variables and baseline characteristics. Cox regression models were used for univariate and multivariate analyses of os and pfs by htn diagnosis and bb use.

Results

Baseline htn, bb use, and anti-htn medication use were not found to be prognostic for improved os. Baseline htn and bb use were not significant predictors of cetuximab benefit.

Conclusions

In chemorefractory mcrc, neither baseline htn nor bb use is a significant prognostic factor. Baseline htn and bb use are not predictive of cetuximab benefit. Further investigation to determine whether baseline htn or bb use have a similarly insignificant impact on prognosis in patients receiving earlier lines of treatment remains warranted.

Nurse Triage in an Irish Out-of-hours General Practice Co-Operative

Specially trained triage nurses play a crucial role in the operation of out-of-hours GP co-operatives. This study aimed to establish the proportion of all patient contacts with the out-of-hours GP co-operative based in the Mid-West of Ireland (Shannondoc), which were managed by triage nurses. A retrospective, descriptive analysis was conducted on the database of contacts to the Shannondoc urgent, out-of-hours primary care co-operative. Of the 110,039 contacts to the service in 2013, 19,147 (17.4%) were classified as being managed by nurses and 14.2% were managed by nurse telephone triage alone. Twenty-four percent of the 19,147 calls managed by nurses involved children under six years. Triage nurses play an important role in administering safe medical advice over the phone. This has implications for the training of triage nurses and the future planning of urgent out-of-hours primary care services.

Co-percolation to tune conductive behaviour in dynamical metallic nanowire networks

Nanowire networks act as self-healing smart materials, whose sheet resistance can be tuned via an externally applied voltage stimulus. This memristive response occurs due to modification of junction resistances to form a connectivity path across the lowest barrier junctions in the network. While most network studies have been performed on expensive noble metal nanowires like silver, networks of inexpensive nickel nanowires with a nickel oxide coating can also demonstrate resistive switching, a common feature of metal oxides with filamentary conduction. However, networks made from solely nickel nanowires have high operation voltages which prohibit large-scale material applications. Here we show, using both experiment and simulation, that a heterogeneous network of nickel and silver nanowires allows optimization of the activation voltage, as well as tuning of the conduction behavior to be either resistive switching, memristive, or a combination of both. Small percentages of silver nanowires, below the percolation threshold, induce these changes in electrical behaviour, even for low area coverage and hence very transparent films. Silver nanowires act as current concentrators, amplifying conductivity locally as shown in our computational dynamical activation framework for networks of junctions. These results demonstrate that a heterogeneous nanowire network can act as a cost-effective adaptive material with minimal use of noble metal nanowires, without losing memristive behaviour that is essential for smart sensing and neuromorphic applications.

Recent advances in anti-neutrophil cytoplasmic antibody-associated vasculitis

Anti-neutrophil cytoplasmic antibody-associated vasculitis is an uncommon inflammatory disease of small to medium-sized vessels that frequently presents with rapidly progressive glomerulonephritis and renal failure though it can affect any organ system. If untreated, the vast majority of patients will die within a year. Current treatments improve prognosis but affected patients remain at a substantially higher risk of death and adverse outcomes. We review the classification of the disease, our understanding of the pathogenesis and epidemiology, and propose future directions for research. We also evaluate the evidence supporting established treatment regimens and the progress of clinical trials for newer treatments to inform the design of future studies.

Tissue-Engineered Tracheal Replacement in a Child: A 4-Year Follow-Up Study

In 2010, a tissue-engineered trachea was transplanted into a 10-year-old child using a decellularized deceased donor trachea repopulated with the recipient's respiratory epithelium and mesenchymal stromal cells. We report the child's clinical progress, tracheal epithelialization and costs over the 4 years. A chronology of events was derived from clinical notes and costs determined using reference costs per procedure. Serial tracheoscopy images, lung function tests and anti-HLA blood samples were compared. Epithelial morphology and T cell, Ki67 and cleaved caspase 3 activity were examined. Computational fluid dynamic simulations determined flow, velocity and airway pressure drops. After the first year following transplantation, the number of interventions fell and the child is currently clinically well and continues in education. Endoscopy demonstrated a complete mucosal lining at 15 months, despite retention of a stent. Histocytology indicates a differentiated respiratory layer and no abnormal immune activity. Computational fluid dynamic analysis demonstrated increased velocity and pressure drops around a distal tracheal narrowing. Cross-sectional area analysis showed restriction of growth within an area of in-stent stenosis. This report demonstrates the long-term viability of a decellularized tissue-engineered trachea within a child. Further research is needed to develop bioengineered pediatric tracheal replacements with lower morbidity, better biomechanics and lower costs.

Tissue-Engineered Tracheal Replacement in a Child: A 4-Year Follow-Up Study

In 2010, a tissue-engineered trachea was transplanted into a 10-year-old child using a decellularized deceased donor trachea repopulated with the recipient's respiratory epithelium and mesenchymal stromal cells. We report the child's clinical progress, tracheal epithelialization and costs over the 4 years. A chronology of events was derived from clinical notes and costs determined using reference costs per procedure. Serial tracheoscopy images, lung function tests and anti-HLA blood samples were compared. Epithelial morphology and T cell, Ki67 and cleaved caspase 3 activity were examined. Computational fluid dynamic simulations determined flow, velocity and airway pressure drops. After the first year following transplantation, the number of interventions fell and the child is currently clinically well and continues in education. Endoscopy demonstrated a complete mucosal lining at 15 months, despite retention of a stent. Histocytology indicates a differentiated respiratory layer and no abnormal immune activity. Computational fluid dynamic analysis demonstrated increased velocity and pressure drops around a distal tracheal narrowing. Cross-sectional area analysis showed restriction of growth within an area of in-stent stenosis. This report demonstrates the long-term viability of a decellularized tissue-engineered trachea within a child. Further research is needed to develop bioengineered pediatric tracheal replacements with lower morbidity, better biomechanics and lower costs.

Inner dynein arm defects causing primary ciliary dyskinesia: repeat testing required

Primary ciliary dyskinesia (PCD) results in chronic nasal symptoms and chest disease leading to bronchiectasis. We noted a number of patients referred for diagnostic testing whose initial results suggested PCD due to an inner dynein arm or radial spoke defect but in whom no abnormality was found on retesting. The present study was an audit of all patients referred for PCD diagnostic testing over a 3-yr period whose initial electron microscopy (EM) and beat pattern analysis suggested an inner dynein arm or radial spoke defect. 21 patients referred for diagnostic testing for PCD suspected of an inner dynein arm defect and six suspected of a radial spoke defect on initial EM and beat pattern analysis had repeat testing performed. On repeat testing, five patients initially suspected of an inner dynein arm defect and one with a radial spoke defect had normal EM and beat pattern, leading to the initial diagnosis being questioned. Patients suspected of PCD due to an inner dynein arm defect or radial spoke defect should have the diagnosis reassessed if it has been based on only one diagnostic sample.

Salt supplementation blunts the blood pressure response to telmisartan with or without hydrochlorothiazide in hypertensive patients with type 2 diabetes

AIMS/HYPOTHESIS

We assessed the effects of sodium chloride (NaCl) supplementation on the blood pressure response to treatment with telmisartan with or without hydrochlorothiazide in hypertensive patients with type 2 diabetes and habitually high (HDS, sodium excretion >200 mmol/24 h on two out of three consecutive occasions) or low (LDS, sodium excretion <100 mmol/24 h on two out of three consecutive occasions) salt intake.

METHODS

Patients received 4 weeks of telmisartan followed by 4 weeks of telmisartan plus hydrochlorothiazide. In a double-blind randomised fashion, patients received sodium chloride (NaCl, 100 mmol/24 h) or placebo capsules in addition to their habitual salt intake during the last 2 weeks of telmisartan and telmisartan plus hydrochlorothiazide therapy. The protocol was repeated with NaCl and placebo capsules administered in reverse order to allow each participant to act as his or her own control. At 0, 4, 8, 14, 18 and 22 weeks, 24 h ambulatory blood pressure (ABP) and 24 h urine collections were performed.

RESULTS

No statistically significant differences were seen in the ABP response in the LDS vs HDS groups to any of the interventions (p = 0.58). NaCl supplementation reduced the effect of telmisartan with or without hydrochlorothiazide on systolic BP by approximately 50% (-5.8 mmHg during NaCl supplementation vs -11.3 mmHg during placebo, mean difference 5.6 mmHg [95% CI 1.7-9.4 mmHg], p = 0.005), irrespective of habitual salt intake. By contrast, addition of hydrochlorothiazide increased the antihypertensive effect of telmisartan on systolic BP by approximately 35% (p = 0.048) in both groups of patients.

CONCLUSIONS/INTERPRETATION

NaCl supplementation blunts the effectiveness of telmisartan with or without hydrochlorothiazide in hypertensive patients with type 2 diabetes, independently of habitual low or high salt intake.

Factors influencing age at diagnosis of primary ciliary dyskinesia in European children

Primary ciliary dyskinesia (PCD) is a hereditary disorder of mucociliary clearance causing chronic upper and lower airways disease. We determined the number of patients with diagnosed PCD across Europe, described age at diagnosis and determined risk factors for late diagnosis. Centres treating children with PCD in Europe answered questionnaires and provided anonymous patient lists. In total, 223 centres from 26 countries reported 1,009 patients aged < 20 yrs. Reported cases per million children (for 5-14 yr olds) were highest in Cyprus (111), Switzerland (47) and Denmark (46). Overall, 57% were males and 48% had situs inversus. Median age at diagnosis was 5.3 yrs, lower in children with situs inversus (3.5 versus 5.8 yrs; p < 0.001) and in children treated in large centres (4.1 versus 4.8 yrs; p = 0.002). Adjusted age at diagnosis was 5.0 yrs in Western Europe, 4.8 yrs in the British Isles, 5.5 yrs in Northern Europe, 6.8 yrs in Eastern Europe and 6.5 yrs in Southern Europe (p < 0.001). This strongly correlated with general government expenditures on health (p < 0.001). This European survey suggests that PCD in children is under-diagnosed and diagnosed late, particularly in countries with low health expenditures. Prospective studies should assess the impact this delay might have on patient prognosis and on health economic costs across Europe.

Factors influencing age at diagnosis of primary ciliary dyskinesia in European children

Primary ciliary dyskinesia (PCD) is a hereditary disorder of mucociliary clearance causing chronic upper and lower airways disease. We determined the number of patients with diagnosed PCD across Europe, described age at diagnosis and determined risk factors for late diagnosis. Centres treating children with PCD in Europe answered questionnaires and provided anonymous patient lists. In total, 223 centres from 26 countries reported 1,009 patients aged < 20 yrs. Reported cases per million children (for 5-14 yr olds) were highest in Cyprus (111), Switzerland (47) and Denmark (46). Overall, 57% were males and 48% had situs inversus. Median age at diagnosis was 5.3 yrs, lower in children with situs inversus (3.5 versus 5.8 yrs; p < 0.001) and in children treated in large centres (4.1 versus 4.8 yrs; p = 0.002). Adjusted age at diagnosis was 5.0 yrs in Western Europe, 4.8 yrs in the British Isles, 5.5 yrs in Northern Europe, 6.8 yrs in Eastern Europe and 6.5 yrs in Southern Europe (p < 0.001). This strongly correlated with general government expenditures on health (p < 0.001). This European survey suggests that PCD in children is under-diagnosed and diagnosed late, particularly in countries with low health expenditures. Prospective studies should assess the impact this delay might have on patient prognosis and on health economic costs across Europe.

High prevalence of primary ciliary dyskinesia in a British Asian population

Determining the prevalence of primary ciliary dyskinesia (PCD) in different populations has proved difficult, with estimates varying between one in 4000 to one in 40,000. The aim of this study was to determine the incidence of PCD in a well-defined highly consanguineous Asian population in the UK. Over a 15-year period all patients suspected of having PCD in the Asian population of Bradford, UK, were tested by measurement of ciliary beat pattern, frequency and electron microscopy. The prevalence of PCD in the population studied was one in 2265. 52% of the patients' parents were first cousins. All patients had a history of chronic cough and nasal symptoms from the first year of life. 73% had a history of neonatal respiratory distress. Clinical suspicion of PCD should be high in populations in which it is possible that high levels of consanguinity may result in an increase in those with PCD. In these communities the combination of chronic cough and nasal symptoms should prompt early diagnostic testing.

Hypertension and TIA

Transient ischemic attack is a medical emergency because early stroke risk after transient ischemic attack is high. Hypertension is the most important modifiable risk factor for stroke and transient ischemic attack. The aims of this review are to provide a summary of the current knowledge concerning the relationship between blood pressure and transient ischemic attack, as well as outline issues regarding diurnal variation and the potential of chronotherapy (timing medications to accord with diurnal patterns of blood pressure). There is a strong relationship between hypertension and the incidence of transient ischemic attack and the subsequent short-term risk for stroke. Ambulatory blood pressure monitoring is a reliable diagnostic and monitoring tool for hypertension and provides additional information about diurnal variation in blood pressure. Different diurnal blood pressure patterns may confer variable stroke risk. Patients with stroke commonly have abnormal diurnal blood pressure patterns and this may relate, in part, to autonomic nervous system dysfunction. However, blood pressure patterns have not been systematically studied in patients with transient ischemic attack. Blood pressure remains poorly controlled in a large proportion of patients after transient ischemic attack and under-treatment and poor adherence are important factors. Chronotherapy for blood pressure may result in more effective blood pressure control. More research is needed in this area. Hypertension is strongly associated with transient ischemic attack. Diurnal blood pressure patterns may influence subsequent stroke risk after transient ischemic attack and more evidence is needed to inform clinical practice to improve blood pressure management for transient ischemic attack patients.

Respiratory medicines for children: current evidence, unlicensed use and research priorities

This European Respiratory Society task force has reviewed the evidence for paediatric medicines in respiratory disease occurring in adults and children. We describe off-licence use, research priorities and ongoing studies. Off-licence and off-label prescribing in children is widespread and potentially harmful. Research areas in asthma include novel formulations and regimens, and individualised prescribing. In cystic fibrosis, future studies will focus on screened infants and robust outcome measures are needed. Other areas include new enzyme and antibiotic formulations and the basic defect. Research into pneumonia should include evaluation of new antibacterials and regimens, rapid diagnostic tests and, in pleural infection, antibiotic penetration, fibrinolytics and surveillance. In uncommon conditions, such as primary ciliary dyskinesia, congenital pulmonary abnormalities or neuromuscular disorders, drugs indicated for other conditions (e.g. dornase alfa) are commonly used and trials are needed. In neuromuscular disorders, the beta-agonists may enhance muscle strength and are in need of evaluation. Studies of antibiotic prophylaxis, immunoglobulin and antifungal drugs are needed in immune deficiency. We hope that this summary of the evidence for respiratory medicines in children, highlighting gaps and research priorities, will be useful for the pharmaceutical industry, the paediatric committee of the European Medicines Agency, academic investigators and the lay public.

Surveillance of acute bacterial meningitis among children admitted to a district hospital in rural Mozambique

BACKGROUND

Acute bacterial meningitis (ABM) remains an important cause of mortality among African children. Epidemiologic data with regard to ABM infection are necessary for prioritizing public health interventions.

METHODS

We strengthened hospital-based surveillance of ABM among children admitted to Manhiça District Hospital (Maputo, Mozambique). Cerebrospinal fluid (CSF) samples were collected from children admitted to the hospital who met clinical criteria of ABM. Laboratory determinations were performed. Clinical information and outcome of cases were recorded.

RESULTS

During the first 12 months of surveillance, which began in January 2006, CSF samples were collected from 642 children <15 years of age with suspected meningitis (18% of all pediatric patients admitted to the hospital during that time). ABM was confirmed in 43 (7%) of the 642 cases. Haemophilus influenzae type b (Hib) (14 cases), pneumococcus (9 cases), and meningococcus (7 cases) represented approximately 70% of confirmed cases. Four of the 9 pneumococci were serotypes covered by the 7-valent pneumococcal conjugate vaccine. The case fatality rate among patients with ABM was 24% (8 of 33 with known outcome); an additional 8 patients left the hospital before discharge. The incidence of ABM was 85 per 100,000 population, which peaked at 2-12 months of age at 1078 cases per 100,000 population. All 9 pneumococci isolates were susceptible to chloramphenicol, and 8 were susceptible to penicillin (the additional 1 had intermediate resistance). For the 10 Hib isolates tested, only 1 was susceptible to chloramphenicol, and 5 were susceptible to ampicillin.

CONCLUSION

These data reinforce the importance of ABM as a cause of hospital admission and death in rural sub-Saharan Africa. Most observed ABM cases could have been prevented by current pneumococcal and Hib conjugate vaccines.

PACAP27 regulates ciliary function in primary cultures of rat brain ependymal cells

Ependymal cells line the brain ventricles and separate the CSF from the underlying neuronal tissue. The function of ependymal cilia is largely unclear however they are reported to be involved in the regulation of CSF homeostasis and host defence against pathogens. Here we present data that implicates a role of pituitary adenylate cyclase-activating polypeptide (PACAP) in the inhibition of ependymal ciliary function, and also that the PACAP effects are not entirely dependent on adenylyl cyclase activation. Primary ependymal cultures were treated with increasing doses of PACAP27 or adenylyl cyclase toxin (ACT), and ciliary beating was recorded using high-speed digital video imaging. Ciliary beat frequency (CBF) and amplitude were determined from the videos. Ependymal CBF and ciliary amplitude were attenuated by PACAP27 in a concentration- and time-dependent manner. The peptide antagonist PACAP6-27 blocked PACAP27-induced decreases in amplitude and CBF. Treatment with ACT caused a decrease in amplitude but had no effect on CBF, this suggests that the inhibition of CBF and amplitude seen with PACAP27 may not be completely explained by G(s)-AC-cAMP pathway. We present here the first observational study to show that activation of PAC1 receptors with PACAP27 has an important role to play in the regulation of ependymal ciliary function.

Music therapy as a non-pharmacological anxiolytic for paediatric radiotherapy patients

Outpatient radiotherapy treatment in the paediatric cancer patient can be a traumatic and an anxiety-provoking experience for both the patient and the family. Music therapy has been widely reported to have psychosocial, educational and physical benefits for the paediatric cancer patient. Using individual case reports, this paper shows the successful use of music therapy as a non-pharmacological anxiolytic in the paediatric radiotherapy, outpatient waiting room setting, by providing the patient and the family with a means of communication, self-expression and creativity.

Effect of sleeping position on nasal patency in newborns

Sleeping posture has been implicated in the pathophysiology of sudden infant death syndrome. The effect of supine and lateral sleeping positions on nasal patency was investigated using acoustic rhinometry in 11 healthy newborns. The implications of the findings in sudden infant death syndrome are discussed.

Effect of Oropharyngeal Length in Drug Lung Delivery via Suspension Pressurized Metered Dose Inhalers

PURPOSE

To determine the effect of the oropharyngeal length in adults on the lung dose of a suspension pressurized metered dose inhaler, and whether employing small volume spacers can alter this role.

METHODS

Depositions of Ventolin Evohaler (100) microg in the oropharyngeal models of two healthy adult subjects with 17.1 cm (short cast) and 19.9 cm (long cast) centerline lengths via three small volume spacers [two spacers with 3 cm effective length but one with 6.5 cm2 (L3) and the other with 24.6 cm2 (L3W) cross sections, and the Optimiser] were studied.

RESULTS

Without using spacers, lung dose of the long cast (19.52 +/- 2.32 microg, mean +/- standard deviation) was significantly larger than that for the short cast (8.08 +/- 1.01 microg, p < 0.006). However, using the L3 spacer with the short cast made the lung dose (18.59 +/- 3.33 microg) similar to that for the long cast alone. Lung doses of the short cast (20.43 +/- 1.42 microg) and the long cast (30.81 +/- 1.84 microg) with the L3W spacer were similar to those with the L3 spacer. However, using the Optimiser spacer increased the lung dose for the short cast (22.27 +/- 6.03 microg) and significantly for the long cast (35.61 +/- 2.19 microg, p < 0.006) compared to those for the L3 spacer. Using spacers increased drug deposition in the oropharynx part of the short cast, and this reduced the lung dose compared to that for the long cast.

CONCLUSION

The oropharyngeal length in adults may affect the lung dose via the pMDIs, which may not be eliminated by using small volume spacers.

Delivery of nebulized budesonide is affected by nebulizer type and breathing pattern

The aim of this study was to determine the output in-vitro of budesonide from two different nebulizers under simulated breathing conditions. The BimboNeb and Nebula nebulizers were used to nebulize 2 mL of budesonide (500 microg) suspension. Particle size was determined by inertial impaction after a 5-min nebulization. Total outputs of the drug from both nebulizers were measured using a sinus flow pump to create simulated breathing conditions. Paediatric and adult breathing patterns were used, with drug output measured after 5 and 10 min nebulization. The mass median aerodynamic diameter of budesonide using the BimboNeb (4.5 microm) was significantly greater than that from the Nebula (3.4 microm) (P<0.01). With the simulated adult breathing pattern, the total drug output after 5 min with the BimboNeb (61.5 microg) was twice that from the Nebula (30.7 microg). For the paediatric breathing pattern, total outputs were very similar for both nebulizers. In all cases, nebulizing for 10 min produced greater drug outputs compared with those after 5 min, particularly for the paediatric breathing pattern. The amount of aerosolized drug available for inhalation needs to be assessed for each nebuliser used and the effect of the patient's breathing pattern should also be taken into account.

Recovery of the ciliated epithelium following acute bronchiolitis in infancy

BACKGROUND

Little is known about the longitudinal changes in the ciliated respiratory epithelium of infants following viral bronchiolitis. A study was undertaken to investigate the time required for the ciliated epithelium to return to normal following bronchiolitis in infants treated with inhaled steroids or placebo.

METHODS

Thirty one previously healthy term infants were studied as part of a clinical trial to determine the effect of 12 weeks of treatment with inhaled fluticasone (FP) or placebo via a spacer device (17 FP, 14 placebo). Nineteen healthy children aged 0-6 years previously studied in our department were used as controls. Nasal biopsy specimens were taken from infants with bronchiolitis and ciliary beat frequency (CBF) was measured before treatment and repeated 3, 6, 12, and 24 weeks later. The epithelial ultrastructure was examined by transmission electron microscopy and a normal errors mixed model based on normal controls was used to examine the time for cilia to return to normal in bronchiolitic infants.

RESULTS

The mean CBF of infants with bronchiolitis (in Hz) at weeks 0, 3, 6, 12, and 24 were 0.5 (n = 4), 10.9 (n = 4), 12.0 (n = 9), 11.9 (n = 8), and 12.1 (n = 7) in the placebo group and 10.6 (n = 6), 11.4 (n = 9), 8.8 (n = 8), 10.9 (n = 4), and 13.2 (n = 7) in the FP group. The time for the epithelial ultrastructure to normalise was as follows: epithelial integrity score (13.1 weeks), % ciliated cells with loss of cilia (14.0 weeks), and % epithelial cells with abnormalities in projection (16.7 weeks) or mitochondria (15.9 weeks). Inhaled steroids had no significant effects on CBF or epithelial ultrastructure.

CONCLUSION

Ciliary loss and epithelial abnormalities persist on average for 13-17 weeks following acute bronchiolitis in infancy.

Suitability of the Upper Airway Models Obtained from MRI Studies in Simulating Drug Lung Deposition from Inhalers

PURPOSE

In this study, the suitability of the upper airway models, obtained by applying a magnetic resonance imaging method, in simulating in vivo aerosol deposition data is determined.

METHODS

Depositions of salbutamol sulfate from two nebulizers in two models, one with constriction at the oropharynx (the constricted cast) and another model without that constriction (the wide cast), were determined.

RESULTS

For the Sidestream and Ventstream nebulizer, 76 +/- 3% (mean +/- standard deviation) and 81 +/- 2% of the emitted dose deposited in the constricted cast, whereas 51 +/- 2% and 49 +/- 3% of the emitted dose deposited in the wide cast, respectively. These values were in good agreement with in vivo data. Mostly, increasing nebulizer charge volume (by normal saline) from 2.5 ml to 5 ml increased significantly the lung dose. However, the lung doses from the Sidestream and Ventstream nebulizer with 2.5 ml charge volume via the wide cast were (1.37 +/- 0.06 and 1.38 +/- 0.05 mg) significantly larger than those for the constricted cast with 5 ml charge volume (0.87 +/- 0.15 and 0.86 +/- 0.21 mg, respectively) (p = 0.005).

CONCLUSIONS

The upper airway models closely simulated the in vivo deposition data. Optimizing the upper airway posture during inhalation via the nebulizers would be more efficient in increasing drug lung delivery than diluting their contents.

What effect does isoflurane have upon ciliary beat pattern: an in vivo study

The effect of anaesthetic gases given via laryngeal mask on nasal ciliary beat pattern and frequency has not been studied. Anaesthetic gases such as isoflurane, halothane and enflurane are known to reduce ciliary beat frequency, but it is unknown whether they also cause cilia to beat in a dyskinetic fashion. Brush biopsies of nasal mucosa were taken pre- and post-anaesthesia with isoflurane, given via a laryngeal mask, from patients undergoing nasal surgery. The samples were observed by light microscopy, and high-speed digital video recordings were made to determine ciliary beat frequency. Using slow-motion playback, the ciliary beat pattern was scored for dysmotility, and the proportion of immotile cilia in the sample was determined. We found that ciliary beat frequency decreased significantly (P < 0.01) after exposure to isoflurane (10.24 Hz compared to 9.20 Hz). However, isoflurane did not alter the ciliary beat pattern or the proportion of immotile cilia.

A randomised crossover trial of facemask efficacy

The efficacy of different facemasks that can be used in the delivery of aerosol medication to children with recurrent wheeze or asthma was investigated. The results showed a statistically significant difference between some of the masks used, which has important implications for current clinical practice