Global birth prevalence of Robin sequence in live-born infants: a systematic review and meta-analysis

Robin sequence (RS), a congenital disorder of jaw maldevelopment and glossoptosis, poses a substantial healthcare burden and has long-term health implications if airway obstruction is suboptimally treated. This study describes the global birth prevalence of RS and investigates whether prevalence estimates differ by geographical location, ethnicity or study data source (registry versus non-registry data). The protocol was prospectively registered with PROSPERO.Databases were searched using keywords and subject terms for "Robin sequence", "epidemiology", "incidence" and "birth prevalence". Meta-analysis was performed fitting random effects models with arcsine transformation.From 34 eligible studies (n=2722 RS cases), pooled birth prevalence was 9.5 per 100 000 live births (95% CI 7.1-12.1) with statistical heterogeneity. One third of studies provided a case definition for RS and numerous definitions were used. A total of 22 countries were represented, predominantly from European populations (53% of studies). There was a trend towards higher birth prevalence in European populations and lower prevalence from registry-based studies. Only two studies reported ethnicity.This study indicates that RS occurs globally. To investigate geographical differences in prevalence, additional studies from non-European populations and reporting of ethnicity are needed. Heterogeneity of estimates may be due to variable diagnostic criteria and ascertainment methods. Recently published consensus diagnostic criteria may reduce heterogeneity among future studies.

2 Pathways to detection of non-infectious childhood uveitis in the UK: findings from the UNICORN cohort study

INTRODUCTION

Prompt detection of childhood uveitis is key to minimising negative impact. From an internationally unique inception cohort, we report pathways to disease detection.UNICORNS is a national childhood non-infectious uveitis study with longitudinal collection of a standardised clinical dataset and patient reported outcomes. Descriptive analysis of baseline characteristics are reported.Amongst 150 recruited children (51% female, 31% non-white ethnicity) age at detection ranged from 2-18yrs (median 10). In 69%, uveitis was diagnosed following onset of symptoms: time from first symptoms to uveitis detection ranged from 0-739days (median 7days), with longer time to detection for those presenting initially to their general practitioner. Non symptomatic children were detected through JIA/other disease surveillance (16%), routine optometry review (5%) or child visual health screening (1%). Commonest underlying diagnoses at uveitis detection were JIA (17%), TINU (9%, higher than pre-pandemic reported UK disease frequency) and sarcoid (1%). 60% had no known systemic disease at uveitis detection. At disease detection, in at least one eye: 34% had structural complications (associated with greater time to detection - 17 days versus 4 days for uncomplicated presentation).The larger relative proportions of children with non-JIA uveitis reported here increase the importance of improving awareness of childhood uveitis amongst the wider clinical communities. There is scope for improvement of pathways to detection. Forthcoming analysis on the full cohort (251 recruited to date across 33 hospitals and 4 nations) will provide nationally representative data on management and the determinants of visual and broader developmental/well-being outcomes.

UNICORNS: Uveitis in childhood prospective national cohort study protocol

Background: Childhood uveitis is a rare inflammatory eye disease which is typically chronic, relapsing-remitting in nature, with an uncertain aetiology (idiopathic). Visual loss occurs due to structural damage caused by uncontrolled inflammation. Understanding of the determinants of long term outcome is lacking, including the predictors of therapeutic response or how to define disease control. Aims: To describe disease natural history and outcomes amongst a nationally representative group of children with non-infectious uveitis, describe the impact of disease course on quality of life for both child and family, and identify determinants of adverse visual, structural and developmental outcomes. Methods: UNICORNS is a prospective longitudinal multicentre cohort study of children newly diagnosed with uveitis about whom a core minimum clinical dataset will be collected systematically. Participants and their families will also complete patient-reported outcome measures annually from recruitment. The association of patient (child- and treatment- dependent) characteristics with outcome will be investigated using logistic and ordinal regression models which incorporate adjustment for within-child correspondence between eyes for those with bilateral disease and repeated outcomes measurement. Discussion: Through this population based, prospective longitudinal study of childhood uveitis, we will describe the characteristics of childhood onset disease. Early (1-2 years following diagnosis) outcomes will be described in the first instance, and through the creation of a national inception cohort, longer term studies will be enabled of outcome for affected children and families.

COVID-19 in congenital heart disease (COaCHeD) study

BACKGROUND

COVID-19 has caused significant worldwide morbidity and mortality. Congenital heart disease (CHD) is likely to increase vulnerability and understanding the predictors of adverse outcomes is key to optimising care.

OBJECTIVE

Ascertain the impact of COVID-19 on people with CHD and define risk factors for adverse outcomes.

METHODS

Multicentre UK study undertaken 1 March 2020-30 June 2021 during the COVID-19 pandemic. Data were collected on CHD diagnoses, clinical presentation and outcomes. Multivariable logistic regression with multiple imputation was performed to explore predictors of death and hospitalisation.

RESULTS

There were 405 reported cases (127 paediatric/278 adult). In children (age <16 years), there were 5 (3.9%) deaths. Adjusted ORs (AORs) for hospitalisation in children were significantly lower with each ascending year of age (OR 0.85, 95% CI 0.75 to 0.96 (p<0.01)). In adults, there were 24 (8.6%) deaths (19 with comorbidities) and 74 (26.6%) hospital admissions. AORs for death in adults were significantly increased with each year of age (OR 1.05, 95% CI 1.01 to 1.10 (p<0.01)) and with pulmonary arterial hypertension (PAH; OR 5.99, 95% CI 1.34 to 26.91 (p=0.02)). AORs for hospitalisation in adults were significantly higher with each additional year of age (OR 1.03, 95% CI 1.00 to 1.05 (p=0.04)), additional comorbidities (OR 3.23, 95% CI 1.31 to 7.97 (p=0.01)) and genetic disease (OR 2.87, 95% CI 1.04 to 7.94 (p=0.04)).

CONCLUSIONS

Children were at low risk of death and hospitalisation secondary to COVID-19 even with severe CHD, but hospital admission rates were higher in younger children, independent of comorbidity. In adults, higher likelihood of death was associated with increasing age and PAH, and of hospitalisation with age, comorbidities and genetic disease. An individualised approach, based on age and comorbidities, should be taken to COVID-19 management in patients with CHD.

The association between childhood hearing loss and self-reported peer victimisation, depressive symptoms, and self-harm: longitudinal analyses of a prospective, nationally representative cohort study

BACKGROUND

Childhood hearing loss (HL) predicts poor mental health and is associated with a higher risk of communication difficulties. The relationship of childhood HL with specific types of poor mental health (such as depressive symptoms or self-harm) and peer victimisation remains unclear.

METHODS

We analysed data from the Millennium Cohort Study (MCS), a prospective observational cohort study of children living in the UK at age 9 months and born between 2000 to 2002. Data were available on the children and their families at ages 9 months, then at 3, 5, 7, 11, and 14 years. Participants were 10,858 singleton children with self-reported data on peer victimisation, depressive symptoms, and self-harm at age 14 years. Multivariable logistic regression models were fitted to estimate odds ratios (OR) for HL with peer victimisation, depressive symptoms, and self-harm. HL presence was examined in terms of any HL between ages 9 months and 14 years, as well as by HL trajectory type (defined by onset and persistence). Analyses were adjusted for potential sources of confounding, survey design, and attrition at age 14 years. Interactions between sex and HL were examined in each model and multiple imputation procedures used to address missing data.

RESULTS

Children with any HL had increased odds of depressive symptoms (OR: 1.32, 95% CI: 1.09-1.60), self-harm (1.41, 1.12-1.78) and, in girls only, peer victimisation (girls: 1.81, 1.29-2.55; boys: 1.05, 0.73-1.51), compared to those without HL. HL with later age at onset and persistence to age 14 years was the only trajectory associated with all outcomes.

CONCLUSIONS

Childhood HL may predict peer victimisation (in girls), depressive symptoms, and self-harm. Further research is needed to identify HL trajectories and methods to facilitate good mental health in children with HL.

Establishing risk factors and outcomes for congenital hypothyroidism with gland in situ using population-based data linkage methods: study protocol

INTRODUCTION

There has been an increase in the birth prevalence of congenital hypothyroidism (CH) since the introduction of newborn screening, both globally and in the UK. This increase can be accounted for by an increase in CH with gland in situ (CH-GIS). It is not known why CH-GIS is becoming more common, nor how it affects the health, development and learning of children over the long term. Our study will use linked administrative health, education and clinical data to determine risk factors for CH-GIS and describe long-term health and education outcomes for affected children.

METHODS AND ANALYSIS

We will construct a birth cohort study based on linked, administrative data to determine what factors have contributed to the increase in the birth prevalence of CH-GIS in the UK. We will also set up a follow-up study of cases and controls to determine the health and education outcomes of children with and without CH-GIS. We will use logistic/multinomial regression models to establish risk factors for CH-GIS. Changes in the prevalence of risk factors over time will help to explain the increase in birth prevalence of CH-GIS. Multivariable generalised linear models or Cox proportional hazards regression models will be used to assess the association between type of CH and school performance or health outcomes.

ETHICS AND DISSEMINATION

This study has been approved by the London Queen Square Research Ethics Committee and the Health Research Authority's Confidentiality Advisory Group CAG. Approvals are also being sought from each data provider. Obtaining approvals from CAG, data providers and information governance bodies have caused considerable delays to the project. Our methods and findings will be published in peer-reviewed journals and presented at academic conferences.

Parents' Experiences of Caring for Their Child at the Time of Discharge After Cardiac Surgery and During the Postdischarge Period: Qualitative Study Using an Online Forum

Background

Congenital heart disease (CHD) is the most common class of birth defects, which encompasses a broad spectrum of severity ranging from relatively minor to extremely complex. Improvements in surgery and intensive care have resulted in an increasing number of infants with the most complex lesions surviving after surgery until the time of discharge from the hospital, but there remain concerns about out-of-hospital mortality, variability in how services are provided at the time of discharge and beyond, and difficulties experienced by some families in accessing care.

Objective

As part of a mixed-methods program of research, this study aimed to elicit parental experiences of caring for a child with CHD after hospital discharge following a cardiac surgery and collect information to inform interviews for a subsequent stage of the project.

Methods

A closed online discussion group was set up via the main Facebook page of the Children’s Heart Federation (CHF), a national charity offering support to children with heart disease and their families. The discussion group was advertised through the charity’s webpage, and interested participants were directed to the charity’s Facebook page from where they could access the closed Facebook group and respond to questions posted. The CHF moderated the forum, and the research team provided questions to be posted on the forum. Responses were collated into a single transcript and subjected to thematic analysis.

Results

The forum was open for 4 months, and 91 participants (mean age 35 years, range 23-58 years, 89 females, 89 parents, and 2 grandparents) submitted demographic information and were given access to the closed forum group. A common experience of isolation emerged from the data, with descriptions of how that isolation was experienced (physical, social, knowledge) and its psychological impact, together with the factors that made it worse or better. Woven through this theme was the notion that parents developed expertise over time.

Conclusions

The use of an online forum provided a means for eliciting data from a large number of parents regarding their experiences of caring for their child after hospital discharge following cardiac surgery. Parents engaged with the forum and were able to articulate what went well and what went less well, together with sharing their stories and supporting each other through doing so. Some parents clearly found participating in the forum a positive experience in itself, demonstrating the potential of social media as a mechanism for providing support and reducing isolation. Information gained from the forum was used to shape questions for interviews with parents in a subsequent phase of the study. Furthermore, the themes identified in the online forum have contributed to identifying ways of improving the provision of care and support for parents of high-risk babies following discharge after cardiac surgery.

Responsiveness to oral prednisolone in severe asthma is related to the degree of eosinophilic airway inflammation

BACKGROUND

Patients with severe asthma appear relatively corticosteroid resistant. Corticosteroid responsiveness is closely related to the degree of eosinophilic airway inflammation. The extent to which eosinophilic airway inflammation in severe asthma responds to treatment with systemic corticosteroids is not clear.

OBJECTIVE

To relate the physiological and inflammatory response to systemic corticosteroids in asthma to disease severity and the baseline extent of eosinophilic inflammation.

METHODS

Patients with mild/moderate and severe asthma were investigated before and after 2 weeks of oral prednisolone (Clintrials.gov NCT00331058 and NCT00327197). We pooled the results from two studies with common protocols. The US study contained two independent centres and the UK one independent centre. The effect of oral corticosteroids on FEV₁ , Pc20, airway inflammation and serum cytokines was investigated. Baseline measurements were compared with healthy subjects.

RESULTS

Thirty-two mild/moderate asthmatics, 50 severe asthmatics and 35 healthy subjects took part. At baseline, both groups of asthmatics had a lower FEV₁ and Pc20 and increased eosinophilic inflammation compared to healthy subjects. The severe group had a lower FEV₁ and more eosinophilic inflammation compared to mild/moderate asthmatics. Oral prednisolone caused a similar degree of suppression of eosinophilic inflammation in all compartments in both groups of asthmatics. There were small improvements in FEV₁ and Pc20 for both mild/ moderate and severe asthmatics with a correlation between the baseline eosinophilic inflammation and the change in FEV₁ . There was a ~50% reduction in the serum concentration of CXCL10 (IP-10), CCL22 (MDC), CCL17 (TARC), CCL-2 (MCP-1) and CCL-13 (MCP-4) in both asthma groups after oral corticosteroids.

CONCLUSIONS AND CLINICAL RELEVANCE

Disease severity does not influence the response to systemic corticosteroids. The study does not therefore support the concept that severe asthma is associated with corticosteroid resistance. Only baseline eosinophilic inflammation was associated with the physiological response to corticosteroids, confirming the importance of measuring eosinophilic inflammation to guide corticosteroid use.

Combining qualitative and quantitative operational research methods to inform quality improvement in pathways that span multiple settings

Background

Improving integration and continuity of care across sectors within resource constraints is a priority in many health systems. Qualitative operational research methods of problem structuring have been used to address quality improvement in services involving multiple sectors but not in combination with quantitative operational research methods that enable targeting of interventions according to patient risk. We aimed to combine these methods to augment and inform an improvement initiative concerning infants with congenital heart disease (CHD) whose complex care pathway spans multiple sectors.

Methods

Soft systems methodology was used to consider systematically changes to services from the perspectives of community, primary, secondary and tertiary care professionals and a patient group, incorporating relevant evidence. Classification and regression tree (CART) analysis of national audit datasets was conducted along with data visualisation designed to inform service improvement within the context of limited resources.

Results

A ‘Rich Picture’ was developed capturing the main features of services for infants with CHD pertinent to service improvement. This was used, along with a graphical summary of the CART analysis, to guide discussions about targeting interventions at specific patient risk groups. Agreement was reached across representatives of relevant health professions and patients on a coherent set of targeted recommendations for quality improvement. These fed into national decisions about service provision and commissioning.

Conclusions

When tackling complex problems in service provision across multiple settings, it is important to acknowledge and work with multiple perspectives systematically and to consider targeting service improvements in response to confined resources. Our research demonstrates that applying a combination of qualitative and quantitative operational research methods is one approach to doing so that warrants further consideration.

Identifying improvements to complex pathways: evidence synthesis and stakeholder engagement in infant congenital heart disease

OBJECTIVES

Many infants die in the year following discharge from hospital after surgical or catheter intervention for congenital heart disease (3-5% of discharged infants). There is considerable variability in the provision of care and support in this period, and some families experience barriers to care. We aimed to identify ways to improve discharge and postdischarge care for this patient group.

DESIGN

A systematic evidence synthesis aligned with a process of eliciting the perspectives of families and professionals from community, primary, secondary and tertiary care.

SETTING

UK.

RESULTS

A set of evidence-informed recommendations for improving the discharge and postdischarge care of infants following intervention for congenital heart disease was produced. These address known challenges with current care processes and, recognising current resource constraints, are targeted at patient groups based on the number of patients affected and the level and nature of their risk of adverse 1-year outcome. The recommendations include: structured discharge documentation, discharging certain high-risk patients via their local hospital, enhanced surveillance for patients with certain (high-risk) cardiac diagnoses and an early warning tool for parents and community health professionals.

CONCLUSIONS

Our recommendations set out a comprehensive, system-wide approach for improving discharge and postdischarge services. This approach could be used to address challenges in delivering care for other patient populations that can fall through gaps between sectors and organisations.

Death and Emergency Readmission of Infants Discharged After Interventions for Congenital Heart Disease: A National Study of 7643 Infants to Inform Service Improvement

Background

Improvements in hospital‐based care have reduced early mortality in congenital heart disease. Later adverse outcomes may be reducible by focusing on care at or after discharge. We aimed to identify risk factors for such events within 1 year of discharge after intervention in infancy and, separately, to identify subgroups that might benefit from different forms of intervention.

Methods and Results

Cardiac procedures performed in infants between 2005 and 2010 in England and Wales from the UK National Congenital Heart Disease Audit were linked to intensive care records. Among 7976 infants, 333 (4.2%) died before discharge. Of 7643 infants discharged alive, 246 (3.2%) died outside the hospital or after an unplanned readmission to intensive care (risk factors were age, weight‐for‐age, cardiac procedure, cardiac diagnosis, congenital anomaly, preprocedural clinical deterioration, prematurity, ethnicity, and duration of initial admission; c‐statistic 0.78 [0.75–0.82]). Of the 7643, 514 (6.7%) died outside the hospital or had an unplanned intensive care readmission (same risk factors but with neurodevelopmental condition and acquired cardiac diagnosis and without preprocedural deterioration; c‐statistic 0.78 [0.75–0.80]). Classification and regression tree analysis were used to identify 6 subgroups stratified by the level (3–24%) and nature of risk for death outside the hospital or unplanned intensive care readmission based on neurodevelopmental condition, cardiac diagnosis, congenital anomaly, and duration of initial admission. An additional 115 patients died after planned intensive care admission (typically following elective surgery).

Conclusions

Adverse outcomes in the year after discharge are of similar magnitude to in‐hospital mortality, warrant service improvements, and are not confined to diagnostic groups currently targeted with enhanced monitoring.

Going home after infant cardiac surgery: a UK qualitative study

OBJECTIVE

To qualitatively assess the discharge processes and postdischarge care in the community for infants discharged after congenital heart interventions in the first year of life.

DESIGN

Qualitative study using semistructured interviews and Framework Analysis.

SETTING

UK specialist cardiac centres and the services their patients are discharged to.

SUBJECTS

Twenty-five cardiologists and nurses from tertiary centres, 11 primary and secondary health professionals and 20 parents of children who had either died after discharge or had needed emergency readmission.

RESULTS

Participants indicated that going home with an infant after cardiac intervention represents a major challenge for parents and professionals. Although there were reported examples of good care, difficulties are exacerbated by inconsistent pathways and potential loss of information between the multiple teams involved. Written documentation from tertiary centres frequently lacks crucial contact information and contains too many specialist terms. Non-tertiary professionals and parents may not hold the information required to respond appropriately when an infant deteriorates, this contributing to the stressful experience of managing these infants at home. Where they exist, the content of formal 'home monitoring pathways' varies nationally, and families can find this onerous.

CONCLUSIONS

Service improvements are needed for infants going home after cardiac intervention in the UK, focusing especially on enhancing mechanisms for effective transfer of information outside the tertiary centre and processes to assist with monitoring and triage of vulnerable infants in the community by primary and secondary care professionals. At present there is no routine audit for this stage of the patient journey.

"I was so worried about every drop of milk" - feeding problems at home are a significant concern for parents after major heart surgery in infancy

Increasing numbers of operations in small infants with complex congenital heart disease are being carried out in the UK year on year, with more surviving the initial operation. However, even after successful surgery some of these infants remain fragile when they are discharged home. The aim of the study was to elicit parents' experiences of caring for a child with complex needs after major congenital heart surgery. We conducted a qualitative study involving semi-structured interviews with parents of 20 children (aged <1-5 months at hospital discharge), who had undergone open heart surgery and subsequently died or been readmitted unexpectedly to intensive care following their initial discharge home. Feeding difficulties following discharge from the specialist surgical centre emerged as one of the most significant parental concerns spontaneously raised in interviews. For some parents the impact of feeding difficulties overshadowed any other cardiac concerns. Key themes centred around feeding management (particularly the practical challenges of feeding their baby), the emotional impact of feeding for parents and the support parents received or needed after discharge with respect to feeding. Caring for a child with congenital heart disease following surgery is demanding, with feeding difficulties being one of the most significant parent stressors. Local health professionals can be a good source of support for parents provided that they are well informed about the needs of a cardiac baby and have realistic expectations of weight gain. Specialist surgical centres should consider addressing issues of parental stress around feeding and weight gain prior to hospital discharge. © 2016 Blackwell Publishing Ltd.

Development of learning facilitation roles for unregistered practitioners

This article describes how unregistered practitioners, such as healthcare assistants and community-based mental health workers, can contribute to the learning, support and development of pre-registration nursing students in clinical practice. It presents the results of an unregistered practitioner co-mentoring scheme piloted in a mental health trust, and demonstrates its benefits for nursing students, unregistered practitioners and nurse mentors. The scheme delivers training and supervision for unregistered practitioners who are starting a formal role in clinical learning. It aims to recognise and develop the contribution of unregistered practitioners to student learning, and to enhance the learning environments in which nursing students train.

Enumeration of free-living aerobic n(2)-fixing h(2)-oxidizing bacteria by using a heterotrophic semisolid medium and most-probable-number technique

A heterotrophic semisolid medium was used with two sensitive assay methods, C(2)H(2) reduction and O(2)-dependent tritium uptake, to determine nitrogenase and hydrogenase activities, respectively. Organisms known to be positive for both activities showed hydrogenase activity in both the presence and absence of 1% C(2)H(2), and thus, it was possible to test a single culture for both activities. Hydrogen uptake activity was detected for the first time in N(2)-fixing strains of Pseudomonas stutzeri. The method was then applied to the most-probable-number method of counting N(2)-fixing and H(2)-oxidizing bacteria in some natural systems. The numbers of H(2)-oxidizing diazotrophs were considerably higher in soil surrounding nodules of white beans than they were in the other systems tested. This observation is consistent with reports that the rhizosphere may be an important ecological niche for H(2) transformation.

Denitrification, acetylene reduction, and methane metabolism in lake sediment exposed to acetylene

Samples of sediment from Lake St. George, Ontario, Canada, were incubated in the laboratory under an initially aerobic gas phase and under anaerobic conditions. In the absence of added nitrate (NO(3)) there was O(2)-dependent production of nitrous oxide (N(2)O), which was inhibited by acetylene (C(2)H(2)) and by nitrapyrin, suggesting that coupled nitrification-denitrification was responsible. Denitrification of added NO(3) was almost as rapid under an aerobic gas phase as under anaerobic conditions. The N(2)O that accumulated persisted in the presence of 0.4 atm of C(2)H(2), but was gradually reduced by some sediment samples at lower C(2)H(2) concentrations. Low rates of C(2)H(2) reduction were observed in the dark, were maximal at 0.2 atm of C(2)H(2), and were decreased in the presence of O(2), NO(3), or both. High rates of light-dependent C(2)H(2) reduction occurred under anaerobic conditions. Predictably, methane (CH(4)) production, which occurred only under anaerobiosis, was delayed by added NO(3) and inhibited by C(2)H(2). Consumption of added CH(4) occurred only under aerobic conditions and was inhibited by C(2)H(2).

Kinetics of inhibition of methane oxidation by nitrate, nitrite, and ammonium in a humisol

The kinetics of inhibition of CH(inf4) oxidation by NH(inf4)(sup+), NO(inf2)(sup-), and NO(inf3)(sup-) in a humisol was investigated. Soil slurries exhibited nearly standard Michaelis-Menten kinetics, with half-saturation constant [K(infm(app))] values for CH(inf4) of 50 to 200 parts per million of volume (ppmv) and V(infmax) values of 1.1 to 2.5 nmol of CH(inf4) g of dry soil(sup-1) h(sup-1). With one soil sample, NH(inf4)(sup+) acted as a simple competitive inhibitor, with an estimated K(infi) of 8 (mu)M NH(inf4)(sup+) (18 nM NH(inf3)). With another soil sample, the response to NH(inf4)(sup+) addition was more complex and the inhibitory effect of NH(inf4)(sup+) was greater than predicted by a simple competitive model at low CH(inf4) concentrations (<50 ppmv). This was probably due to NO(inf2)(sup-) produced through NH(inf4)(sup+) oxidation. Added NO(inf2)(sup-) was inherently more inhibitory of CH(inf4) oxidation at low CH(inf4) concentrations, and more NO(inf2)(sup-) was produced as the CH(inf4)-to-NH(inf4)(sup+) ratio decreased and the competitive balance shifted. NaNO(inf3) was a noncompetitive inhibitor of CH(inf4) oxidation, but inhibition was evident only at >10 mM concentrations, which also altered soil pHs. Similar concentrations of NaCl were also inhibitory of CH(inf4) oxidation, so there may be no special inhibitory mechanism of nitrate per se.

Effects of Nitrapyrin [2-Chloro-6-(Trichloromethyl) Pyridine] on the Obligate Methanotroph Methylosinus trichosporium OB3b

Nitrapyrin inhibited growth, CH(4) oxidation, and NH(4) oxidation, but not the oxidation of CH(3)OH, HCHO, or HCOONa, by Methylosinus trichosporium OB3b, suggesting that nitrapyrin acts against the methane monooxygenase enzyme system. The inhibition of CH(4) oxidation could be reversed by repeated washing of nitrapyrin-inhibited cells, indicating that its effect is bacteriostatic. The addition of Cu did not release the inhibition. Methane oxidation was also inhibited by 6-chloro-2-picoline. These data suggest that the mode of action of nitrapyrin on M. trichosporium is different from that on chemoautotrophic NH(4) oxidizers or methanogens.

Utility of exhaled nitric oxide as a noninvasive biomarker of lung inflammation in a disease model

There is a great deal of interest in developing less invasive markers for monitoring airway inflammation and the effect of possible novel anti-inflammatory therapies that may take time to impact on disease pathology. Exhaled nitric oxide (eNO) has been shown to be a reproducible, noninvasive indicator of the inflammatory status of the airway in the clinic. The aim of the present study was to determine the usefulness of measuring eNO as a marker of the anti-inflammatory impact of glucocorticoid and an inhibitor of kappaB kinase-2 (IKK-2) inhibitor 2-[(aminocarbonyl)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide (TPCA-1), in a pre-clinical model of airway inflammation. Rats were given vehicle, budesonide or TPCA-1 prior to exposure to lipopolysaccharide, previously shown to induce an increase in eNO and airway neutrophilia/eosinophilia. Comparison of the effect of the two compounds on inflammatory components demonstrated a significant correlation between the impact on eNO and inflammatory cell burden in the airway. The current study demonstrates the usefulness of profiling potential disease-modifying therapies on exhaled nitric oxide levels and the way in which an effect on this noninvasive biomarker relates to effects on pathological parameters such as lung cellularity. Information from studies such as the current one would suggest that the measurement of exhaled nitric oxide has potential for monitoring inflammatory status in lung tissue.

Twenty years of active paediatric surveillance in the the UK and Republic of Ireland

In July 2006 the British Paediatric Surveillance Unit (BPSU, http://bpsu.inopsu.com/) celebrated its twentieth year of surveillance

Newborn screening for congenital heart defects: a systematic review and cost-effectiveness analysis

OBJECTIVES

To provide evidence to inform policy decisions about the most appropriate newborn screening strategy for congenital heart defects, identifying priorities for future research that might reduce important uncertainties in the evidence base for such decisions.

DATA SOURCES

Electronic databases. Groups of parents and health professionals.

REVIEW METHODS

A systematic review of the published medical literature concerning outcomes for children with congenital heart defects was carried out. A decision analytic model was developed to assess the cost-effectiveness of alternative screening strategies for congenital heart defects relevant to the UK. A further study was then carried out using a self-administered anonymous questionnaire to explore the perspectives of parents and health professionals towards the quality of life of children with congenital heart defects. The findings from a structured review of the medical literature regarding parental experiences were linked with those from a focus group of parents of children with congenital heart defects.

RESULTS

Current newborn screening policy comprises a clinical examination at birth and 6 weeks, with specific cardiac investigations for specified high-risk children. Routine data are lacking, but under half of affected babies, not previously identified antenatally or because of symptoms, are identified by current newborn screening. There is evidence that screen-positive infants do not receive timely management. Pulse oximetry and echocardiography, in addition to clinical examination, are alternative newborn screening strategies but their cost-effectiveness has not been adequately evaluated in a UK setting. In a population of 100,000 live-born infants, the model predicts 121 infants with life-threatening congenital heart defects undiagnosed at screening, of whom 82 (68%) and 83 (69%) are detected by pulse oximetry and screening echocardiography, respectively, but only 39 (32%) by clinical examination alone. Of these, 71, 71 and 34, respectively, receive a timely diagnosis. The model predicts 46 (0.5%) false-positive screening diagnoses per 100,000 infants with clinical examination, 1168 (1.3%) with pulse oximetry and 4857 (5.4%) with screening echocardiography. The latter includes infants with clinically non-significant defects. Total programme costs are predicted of pound 300,000 for clinical examination, pound 480,000 for pulse oximetry and pound 3.54 million for screening echocardiography. The additional cost per additional timely diagnosis of life-threatening congenital heart defects ranges from pound 4900 for pulse oximetry to pound 4.5 million for screening echocardiography. Including clinically significant congenital heart defects gives an additional cost per additional diagnosis of pound 1500 for pulse oximetry and pound 36,000 for screening echocardiography. Key determinants for cost-effectiveness are detection rates for pulse oximetry and screening echocardiography. Parents and health professionals place similar values on the quality of life outcomes of children with congenital heart defects and both are more averse to neurological than to cardiac disability. Adverse psychosocial effects for parents are focused around poor management and/or false test results.

CONCLUSIONS

Early detection through newborn screening potentially can improve the outcome of congenital heart defects; however the current programme performs poorly, and lacks monitoring of quality assurance, performance management and longer term outcomes. Pulse oximetry is a promising alternative newborn screening strategy but further evaluation is needed to obtain more precise estimates of test performance and to inform optimal timing, diagnostic and management strategies. Although screening echocardiography is associated with the highest detection rate, it is the most costly strategy and has a 5% false-positive rate. Improving antenatal detection of congenital heart defects increases the cost per timely postnatal diagnosis afforded by any newborn screening strategy but does not alter the relative effects of the strategies. An improvement of timely management of screen positive infants is essential. Further research is required to refine the detection rate and other aspects of pulse oximetry, to evaluate antenatal screening strategies more directly, and to investigate the psychosocial effects of newborn screening for congenital heart defects.

An audit of forceps delivery in Trinidad

An audit of 247 consecutive forceps deliveries during a 6-year period was undertaken in order to establish trends in recourse to this instrument, maternal complications and fetal outcome. The chief indications were prolonged second stage of labour and poor maternal effort. Our overall forceps rate of 0.81% betrays a marked divergence from the practice in metropolitan countries. Although birth injuries were a major drawback, assistance with forceps still appears to be a safer alternative than caesarean section when a problem exists which impedes spontaneous delivery in the second stage. In choosing between obstetric options, we voluntarily take one course which we dislike because the alternative is more objectionable still; the unpleasantness of the choice does not destroy its reality.

Localized whole eye radiotherapy for retinoblastoma using a (125)I applicator, "claws"

PURPOSE

To treat children with retinoblastoma, who require whole eye radiotherapy, with a specially designed (125)I applicator that irradiates the eye while sparing the surrounding tissues.

METHODS AND MATERIALS

Under general anesthesia, a pericorneal ring is attached to the 4 extraocular muscles, and 4 appendages, each loaded with (125)I seeds, are inserted beneath the conjunctiva in-between each pair of muscles and attached anteriorly to the ring. Twenty-nine eyes were treated. Eighteen received a median dose of 28 Gy during 91 hours and 11 received 40 Gy during 122 hours, when the relative biologic effectiveness was taken as 1 instead of 1.5. Six had received prior chemotherapy.

RESULTS

Twenty-four eyes were followed up for 2-157 months (median 29). Although 22 eyes responded, local control was achieved in 13 patients, 3 of whom required additional treatment for new tumors; a further 3 required additional treatment for tumor recurrence as well as new tumors. One of these eyes was enucleated for neovascular glaucoma. All 6 Group I-III eyes and 6 of 18 Group V eyes were retained for 2-157 months (median 39), with good vision in 10 eyes. Three developed cataracts 7, 8, and 12 years later, 1 of which has been removed.

CONCLUSIONS

This is a new way of irradiating the whole eye with a minimal dose to the surrounding tissues. The treatment time is only 5 days. It is effective in Groups I-III, but only 33% of Group V eyes retained vision. No late cosmetic defects occurred.

Quantifying functional gene populations: comparing gene abundance and corresponding enzymatic activity using denitrification and nitrogen fixation in pulp and paper mill effluent treatment systems

The relationship between the abundance of three functional genes and their corresponding biochemical reaction rates was investigated in several activated sludge and mill effluent microbial communities. Gene probes were prepared for two key denitrification genes (nirS and nirK) and for one nitrogen-fixation gene (nifH) and were validated using a variety of strains of known nir and nif genotype. ATP-based measures of viable cell numbers were used to provide total population sizes. In certain microbial communities (activated sludge enrichment cultures and multiple samples taken from the same mill primary clarifier), a strong correlation was observed between gene abundance and biochemical activity rates. However, when comparing several different nonenriched activated sludge bioreactors and separate primary clarifier microbial communities, the ratio of specific gene abundance to biochemical activity rates varied widely. These results suggest that in cases where a microbial community is not fully induced for a given biochemical activity or when very different communities are compared, quantitative gene probing can give a better measure of a community's potential to carry out the encoded function than can the relevant biochemical assay. However, the gene quantitation method employed here probably underestimated the true number of probed genes present in the microbial communities due to nirS and nifH genes in the communities having reduced DNA sequence similarity with the probes used.

Denitrification: microbiology and ecology

The ability of some aerobic microorganisms to reduce nitrogen oxides, especially nitrate, to gaseous products enables them to grow in oxygen-limiting conditions by using the oxides as electron acceptors. Denitrifying respiration is not as efficient as oxygen respiration so growth is slower. The ability to denitrify is found in a wide variety of unrelated bacteria and even in some fungi, and biochemical mechanisms are now moderately well understood. Major factors regulating denitrification are the availability of the nitrogen oxides, the availability of reductant (mostly organic carbon compounds but inorganic compounds may be used), and decreased oxygen concentration. These three factors are in turn governed by many other factors such as water content, pH, porosity, and the presence of inhibitory compounds, which may act to cause accumulation of ionic (nitrite) or gaseous (nitric oxide, nitrous oxide) intermediates. The prediction of rates of denitrification and release of intermediates such as nitrous oxide in particular environments is proving to be difficult.

A MAGE-3 peptide recognized on HLA-B35 and HLA-A1 by cytolytic T lymphocytes

Antigens encoded by MAGE genes are of particular interest for cancer immunotherapy because of their strict tumoral specificity and because they are shared by many tumors. Antigenic peptide EVDPIGHLY encoded by MAGE-3 and known to be presented by HLA-A*0101 is currently being used in therapeutic vaccination trials. We report here that a cytolytic T-lymphocyte (CTL) clone, which is restricted by HLA-B*3501, recognizes the same peptide and, importantly, lyses HLA-B*3501 tumor cells expressing MAGE-3. These results infer that the current clinical use of peptide EVDPIGHLY can now be extended to HLA-B*3501 patients.

Electrophysiological recordings from the rat prostate gland in vitro: identified single-cell and transepithelial (lumen) potentials

OBJECTIVE

To develop a preparation for the in vitro maintenance of the rat prostate gland and thus allow intracellular and transepithelial voltage measurements.

MATERIALS AND METHODS

Ventral prostate glands from male rats were dissected free of connective tissue, separated into smaller lobes and maintained in vitro at 30 degrees C. Voltages were recorded with sharp micropipettes in identified cellular and luminal compartments, differentiated by several electrophysiological and histological parameters, including intracellular staining.

RESULTS

Intracellular epithelial membrane potentials (median -40 mV) and transepithelial or luminal potentials (mean -4.2 mV) were recorded successfully. Luminal epithelial cells were dye-coupled. Prostate tissue could be maintained in vitro with no apparent electrophysiological or structural deterioration for up to approximately 7 h.

CONCLUSION

Rat prostate tissue can be successfully maintained in vitro and electrophysiological recordings made from identified cellular compartments.

Production and consumption of nitric oxide by three methanotrophic bacteria

We studied nitrogen oxide production and consumption by methanotrophs Methylobacter luteus (group I), Methylosinus trichosporium OB3b (group II), and an isolate from a hardwood swamp soil, here identified by 16S ribosomal DNA sequencing as Methylobacter sp. strain T20 (group I). All could consume nitric oxide (nitrogen monoxide, NO), and produce small amounts of nitrous oxide (N(2)O). Only Methylobacter strain T20 produced large amounts of NO (>250 parts per million by volume [ppmv] in the headspace) at specific activities of up to 2.0 x 10(-17) mol of NO cell(-1) day(-1), mostly after a culture became O(2) limited. Production of NO by strain T20 occurred mostly in nitrate-containing medium under anaerobic or nearly anaerobic conditions, was inhibited by chlorate, tungstate, and O(2), and required CH(4). Denitrification (methanol-supported N(2)O production from nitrate in the presence of acetylene) could not be detected and thus did not appear to be involved in the production of NO. Furthermore, cd(1) and Cu nitrite reductases, NO reductase, and N(2)O reductase could not be detected by PCR amplification of the nirS, nirK, norB, and nosZ genes, respectively. M. luteus and M. trichosporium produced some NO in ammonium-containing medium under aerobic conditions, likely as a result of methanotrophic nitrification and chemical decomposition of nitrite. For Methylobacter strain T20, arginine did not stimulate NO production under aerobiosis, suggesting that NO synthase was not involved. We conclude that strain T20 causes assimilatory reduction of nitrate to nitrite, which then decomposes chemically to NO. The production of NO by methanotrophs such as Methylobacter strain T20 could be of ecological significance in habitats near aerobic-anaerobic interfaces where fluctuating O(2) and nitrate availability occur.

Malignant melanoma of the eyelid and palpebral conjunctiva treated with iodine-125 brachytherapy

OBJECTIVE

To evaluate the results on malignant melanomas of the eyelid and palpebral conjunctiva treated with iodine-125 (125I) brachytherapy with shielding of the eye.

DESIGN

Noncomparative case series.

PARTICIPANTS

Fourteen patients treated with 125I brachytherapy at an ocular oncology referral center from 1974 through 1996, all of whom had had previous debulking, incomplete resection, or recurrence after surgery.

INTERVENTION

A stainless steel pericorneal ring eyeshield was attached to the extraocular muscles, over which a lid was fitted to protect the cornea without touching it. Iodine-125 seeds in polythene tubes were inserted into the eyelid and attached to the lid margin for a single plane implant. In five cases additional seeds were glued on to the shield as well for a volume implant. A median dose of 37 Gy (range, 17.3-67.6 Gy) was given over the course of 113 hours (range, 47-190 hours) to the outer surface of target volume.

MAIN OUTCOME MEASURES

Local control is regarded as freedom from recurrence in those without measurable disease and complete clinical regression in those with measurable disease. Morbidity is assessed in terms of function and cosmesis. Survival is given from the time of the implant.

RESULTS

There was local control in 13 patients maintained from 11 to 227 months (median, 39 months). There were two recurrences at 8 and 13 months in the first patient who received 17.3 Gy. Late complications consisted of mild eyelid telangiectasia, mild eyelid atrophy, and loss of eyelashes in most patients. Five patients, four of whom had upper eyelid tumors, experienced a dry eye, which was managed with tear supplements, and one of these patients developed a cataract. A corneal ulcer developed in one eye, which later perforated after treatment of a subsequent bulbar melanoma and was exenterated. Another eye was enucleated after treatment for a subsequent melanoma in the fornix. Cosmesis was acceptable to patient and doctor in the other 12 patients. Vision was maintained in seven patients, reduced in two, and not recorded in the remaining three patients. Three patients died of hematogenous metastases at 44, 62, and 79 months after implant, one of bronchial carcinoma at 46 months and one of an astrocytoma at 39 months. All patients were clear of local disease. The remainder survived for a median of 45 months (range, 18-227 months).

CONCLUSIONS

Iodine-125 brachytherapy can be used as an alternative to wide excision or exenteration of these tumors. There was good local control, reasonable maintenance of vision, and good cosmesis.

Critical role of CD23 in allergen-induced bronchoconstriction in a murine model of allergic asthma

CD23-deficient and anti-CD23 monoclonal antibody-treated mice were used to investigate the role of the low-affinity receptor for IgE (CD23) in allergic airway inflammation and airway hyperresponsiveness (AHR). While there were no significant differences in ovalbumin (OVA)-specific IgE titers and tissue eosinophilia, evaluation of lung function demonstrated that CD23-/- mice showed an increased AHR to methacholine (MCh) when compared to wild-type mice but were completely resistant to the OVA challenge. Anti-CD23 Fab fragment treatment of wild-type mice did not affect the MCh-induced AHR but significantly reduced the OVA-induced airway constriction. These results imply a novel role for CD23 in lung inflammation and suggest that anti-CD23 Fab fragment treatment may be of therapeutic use in allergic asthma.

Notch1 inhibits neurite outgrowth in postmitotic primary neurons

Notch plays an important role in cell fate decisions in uncommitted proliferative cells, including neurogenesis, but is believed to not have a role in postmitotic cells. We have shown previously that Notch1 is highly expressed in embryonal mouse and human brain, but surprisingly it continues to be expressed at low levels in the adult brain. The function of Notch1 in postmitotic neurons in mammals is unknown. To better understand the potential role of Notch1 in mature central nervous system neurons we studied the effect of Notch1 transfection on neurite outgrowth in primary neocortex hippocampal neurons. Transfection at two days in vitro with full length Notch1 inhibited neurite outgrowth. Transfection at five to six days in vitro, after neurite outgrowth was established, led to apparent regression of neurites. These effects were enhanced when truncated constitutively active forms of Notch1 were introduced. Co-transfection with Numb, a physiological inhibitor of Notch, blocked Notch's effect on neurite outgrowth. We also examined whether Notch1 could activate C-promoter binding factor (CBF1) transcription factor using C-promoter binding factor-luciferase constructs, and demonstrated that this signal transduction pathway is present and can be activated in postmitotic neurons. Our results show that in postmitotic neurons Notch1 influences neurite morphology, and can activate its native signal transduction pathway. These data strongly suggest that Notch1 may play a physiologically important role in the central nervous system beyond neurogenesis.

Chloramphenicol inhibition of denitrifying enzyme activity in two agricultural soils

Chloramphenicol, at concentrations greater than 0.1 g/liter (0.3 mM), inhibited the denitrifying enzyme activity (DEA) of slurries of humisol and sandy loam soils by disrupting the activity of existing nitrate reductase enzymes. When the concentration of chloramphenicol was increased from 0.1 to 2.0 g/liter (6.0 mM), the rate of nitrite production from nitrate decreased by 25 to 46%. The rate of NO production from nitrate decreased by 20 to 39%, and the rate of N(2)O production from nitrate, in the presence of acetylene (DEA), decreased by 21 to 61%. The predicted values of DEA at 0 g of chloramphenicol/liter computed from linear regressions of DEA versus chloramphenicol concentration were 18 to 43% lower than DEA measurements made in the absence of chloramphenicol and within a few per cent of DEA rates measured in the presence of 0.1 g of chloramphenicol/liter. We conclude that DEA assays should be carried out with a single (0.1-g/liter) chloramphenicol concentration. Chloramphenicol at concentrations greater than 0.1 g/liter inhibits the activity of existing denitrifying enzymes and should not be used in DEA assays.

The implementation of a new parallel child health record

After a decade of research, the parent-held Personal Child Health Record was introduced in some parts of the United Kingdom in 1991, coinciding with the enforcement of the Children Act 1989. It was designed as the main record of a child's health and development, to be used until adulthood and to be held by parents. Several Health Care Trusts have since discovered a need to maintain parallel records in the best interests of children. Barnet introduced the 'Joint Professional Record' in 1995 for selected children, such as children on the Child Protection Register. The Joint Professional Record (JPR) is a single, clinic-held, parallel record for multidisciplinary use. We undertook a programme of audit and staff seminars to develop and evaluate use of the JPR. We discuss, below, the impact of this record on professional working relationships and consider the implications of its use as a confidential record and within our policy of working in partnership with parents. In our experience, the JPR has proved a useful adjunct to clinical supervision in the arena of Child Protection and is appropriately used for children in need of protection and those with 'special needs'.

The Alzheimer-related gene presenilin 1 facilitates notch 1 in primary mammalian neurons

The normal functional neurobiology of the Alzheimer's disease (AD) related gene presenilin 1 (PS1) is unknown. One clue comes from a genetic screen of Caenorhabditis elegans, which reveals that the presenilin homologue sel-12 facilitates lin-12 function [D. Levitan, I. Greenwald, Facilitation of lin-12-mediated signalling by sel-12, a Caenorhabditis elegans S182 Alzheimer's disease gene, Nature 377 (1995) 351-355]. The mammalian homologue of lin-12, Notch1, is a transmembrane receptor that plays an important role in cell fate decisions during development, including neurogenesis, but does not have a known function in fully differentiated cells. To better understand the potential role of Notch1 in mammalian postmitotic neurons and to test the hypothesis that Notch and PS 1 interact, we studied the effect of Notch1 transfection on neurite outgrowth in primary cultures of hippocampal/cortical neurons. We demonstrate that Notch1 inhibits neurite extension, and thus has a function in postmitotic mature neurons in the mammalian CNS. Furthermore, we present evidence demonstrating that there is a functional interaction between PS1 and Notch1 in mammalian neurons, analogous to the sel-12/lin-12 interaction in vulval development in C. elegans [D. Levitan, T. Doyle, D. Brousseau, M. Lee, G. Thinakaran, H. Slunt, S. Sisodia, I. Greenwald, Assessment of normal and mutant human presenilin function in Caenorhabditis elegans, Proc. Natl. Acad. Sci. U.S.A. 93 (1996) 14940-14944; D. Levitan, I. Greenwald, Effect of Sel-12 presenilin on Lin-12 localization and function in Caenorhabditis elegans, Development, 125 (1998) 3599-3606]. The inhibitory effect of Notch1 on neurite outgrowth is markedly attenuated in neurons from PS1 knockout mice, and enhanced in neurons from transgenic mice overexpressing wild type PS1, but not mutant PS1. These data suggest that PS1 facilitates Notch1 function in mammalian neurons, and support the hypothesis that a functional interaction exists between PS1 and Notch1 in postmitotic mammalian neurons.

Inhibition of nitrifiers and methanotrophs from an agricultural humisol by allylsulfide and its implications for environmental studies

Allylsulfide, an inhibitor of ammonia monooxygenase, was tested to determine its ability to inhibit nitrification and methane oxidation in pure cultures, in agricultural humisol enrichment cultures, and in humisol slurries. We confirmed that allylsulfide is a differential inhibitor of cultures of nitrifiers and methanotrophs at concentrations of 1 and 200 microM, respectively, which result in 50% inhibition. However, although a nitrifying enrichment culture added to sterilized humisol was inhibited 50% by 4 microM allylsulfide, 500 microM allylsulfide was necessary for 50% inhibition of the endogenous nitrifying activity in nonsterile humisol. We concluded that native nitrifiers were protected, possibly by being in colonial aggregates or sheltered microenvironments.

High-affinity methane oxidation by a soil enrichment culture containing a type II methanotroph

Methanotrophic bacteria in an organic soil were enriched on gaseous mixing ratios of <275 parts per million of volume (ppmv) of methane (CH4). After 4 years of growth and periodic dilution (>10(20) times the initial soil inoculum), a mixed culture was obtained which displayed an apparent half-saturation constant [Km(app)] for CH4 of 56 to 186 nM (40 to 132 ppmv). This value was the same as that measured in the soil itself and about 1 order of magnitude lower than reported values for pure cultures of methane oxidizers. However, the Km(app) increased when the culture was transferred to higher mixing ratios of CH4 (1,000 ppmv, or 1%). Denaturing gradient gel electrophoresis of the enrichment grown on <275 ppmv of CH4 revealed a single gene product of pmoA, which codes for a subunit of particulate methane monooxygenase. This suggested that only one methanotroph species was present. This organism was isolated from a sample of the enrichment culture grown on 1% CH4 and phylogenetically positioned based on its 16S rRNA, pmoA, and mxaF gene sequences as a type II strain of the Methylocystis/Methylosinus group. A coculture of this strain with a Variovorax sp., when grown on <275 ppmv of CH4, had a Km(app) (129 to 188 nM) similar to that of the initial enrichment culture. The data suggest that the affinity of methanotrophic bacteria for CH4 varies with growth conditions and that the oxidation of atmospheric CH4 observed in this soil is carried out by type II methanotrophic bacteria which are similar to characterized species.

Genetic evidence for species boundaries in frogs of the Litoria citropa species-group (Anura:Hylidae)

The Litoria citropa species-group comprises several small to medium-sized tree-frog species found from mid-eastern Queensland to eastern Victoria in a variety of habitats along streams associated with the Great Dividing Range. The smaller members of the Litoria citropa species-group, Litoria phyllochroa and L. pearsoniana, have a confused taxonomic history with the taxonomic status of several populations, some regarded as endangered, still in doubt. Multi-locus allozyme electrophoretic profiles and nucleotide sequences of a portion of the mitochondrial 16S ribosomal RNA gene were used to examine the evolutionary relationships of populations that are a geographically comprehensive and morphologically representative sample of the species-group. These data demonstrate the presence of a minimum of three species: L. nudidigitus, L. phyllochroa and a third species whose taxonomic name is yet to be resolved. This third taxon encompasses a wide range of allozyme and mitochondrial nucleotide diversity and can be divided into at least four evolutionarily significant units (ESUs) that replace each other in a linear sequence from north of the Hunter Valley in New South Wales to the Kroombit Tops in central Queensland. A possible zone of hybridisation between the southernmost pair of these ESUs was identified in northern New South Wales. The fourth ESU, a northern outlier of the range of the species-group, is confined to Kroombit Tops, central Queensland.While its phylogenetic relationship with the other three ESUs was not resolved precisely by the present analysis, it nevertheless comprises a distinct and very divergent mitochondrial lineage of considerable antiquity.Resolution of the status of a further name applied to the species-group, L. piperata, awaits a morphological analysis that includes the relevant type material.

Effect of selected monoterpenes on methane oxidation, denitrification, and aerobic metabolism by bacteria in pure culture

Selected monoterpenes inhibited methane oxidation by methanotrophs (Methylosinus trichosporium OB3b, Methylobacter luteus), denitrification by environmental isolates, and aerobic metabolism by several heterotrophic pure cultures. Inhibition occurred to various extents and was transient. Complete inhibition of methane oxidation by Methylosinus trichosporium OB3b with 1.1 mM (-)-alpha-pinene lasted for more than 2 days with a culture of optical density of 0.05 before activity resumed. Inhibition was greater under conditions under which particulate methane monooxygenase was expressed. No apparent consumption or conversion of monoterpenes by methanotrophs was detected by gas chromatography, and the reason that transient inhibition occurs is not clear. Aerobic metabolism by several heterotrophs was much less sensitive than methanotrophy was; Escherichia coli (optical density, 0.01), for example, was not affected by up to 7.3 mM (-)-alpha-pinene. The degree of inhibition was monoterpene and species dependent. Denitrification by isolates from a polluted sediment was not inhibited by 3.7 mM (-)-alpha-pinene, gamma-terpinene, or beta-myrcene, whereas 50 to 100% inhibition was observed for isolates from a temperate swamp soil. The inhibitory effect of monoterpenes on methane oxidation was greatest with unsaturated, cyclic hydrocarbon forms [e.g., (-)-alpha-pinene, (S)-(-)-limonene, (R)-(+)-limonene, and gamma-terpinene]. Lower levels of inhibition occurred with oxide and alcohol derivatives [(R)-(+)-limonene oxide, alpha-pinene oxide, linalool, alpha-terpineol] and a noncyclic hydrocarbon (beta-myrcene). Isomers of pinene inhibited activity to different extents. Given their natural sources, monoterpenes may be significant factors affecting bacterial activities in nature.

Cytokine control of PMN phagocytosis: regulatory effects of hypoxemia and hypoxemia-reoxygenation

We investigated the effects of hypoxemia and hypoxemia-reoxygenation (H/R) on interleukin-8 (IL-8), tumor necrosis factor-alpha (TNF-alpha), or IL-1beta stimulation of whole blood polymorphonuclear leukocyte (PMN) phagocytosis and bactericidal activity. Whole blood PMN were rendered hypoxemic (venous PO2 < 15 mmHg), normoxic (venous PO2 60-80 mmHg), or reoxygenated after hypoxemia (H/ R = venous PO2 150-200 mmHg) and were incubated with IL-8, TNF-alpha, or IL-1beta before sequential addition of serum-opsonized fluorescent microspheres and fluorescein isothiocyanate-conjugated mouse anti-human CD64, CD32w, CD16, CD35, or CD11b/CD18. Concomitant two-color flow cytometric analyses were then performed measuring mean channel fluorescence and the percentage of PMN positive for phagocytosis, with simultaneous subset receptor analysis on populations of PMN that exceeded control levels of phagocytosis. During hypoxemia, whole blood PMN phagocytosis in the presence of IL-8, TNF-alpha, or IL-1beta was increased compared with normoxia. Northern blot analyses revealed an increase in steady-state mRNA levels for CD32w during hypoxemia + IL-8 and CD64 during hypoxemia + IL-1beta. During reoxygenation, both whole blood PMN phagocytosis and bactericidal activity were reduced in the presence of IL-8, TNF-alpha, or IL-1beta, and in subsets of PMN with reduced phagocytosis H/R reduced CD64, CD32w, CD16, CD35, and CD11b/CD18 expression in the presence of each cytokine. Northern blot analyses revealed that H/R reduced mRNA levels for opsonic receptors primarily for IL-1beta-stimulated PMN. These results demonstrate a direct regulatory effect of hypoxemia and H/R on whole blood PMN phagocytosis, receptor expression, and steady-state mRNA levels of both Fc(gamma) and complement receptors.

Nitric oxide synthase is expressed in human macrophages during foreign body inflammation

Although nitric oxide (NO) is a well documented effector molecule in rodent macrophages, its significance in human mononuclear phagocytic cells has been controversial. The foreign body inflammatory reaction around loosened joint replacement implants leads to formation of an osteolytic granulomatous pseudo-synovial membrane rich in activated macrophages. We studied 13 specimens of interface membrane tissue collected from revision surgery of aseptically loosened hip and knee prostheses for the presence of inducible NO synthase (iNOS). The presence of iNOS was demonstrated immunohistochemically in 10 of these specimens. Within the tissue this enzyme was confined to macrophages and vascular endothelial cells. iNOS activity was demonstrated biochemically by measuring the calcium-independent generation of citrulline from L-arginine, and the presence of iNOS mRNA was demonstrated using reverse transcriptase polymerase chain reaction. NO synthesis in the interface tissue may be an important factor in the maintenance of the inflammatory and osteolytic processes.

Standardization of pain management in the postanesthesia care unit

A project is described in which a standard in the Post Anesthesia Care Unit (PACU) for managing patients with acute pain was implemented. The nurses' documentation and their perceptions concerning pain management were assessed. The data collected from the pre-questionnaires showed misconceptions about pain medication, lack of knowledge about measurement tools, and value systems that were inconsistent with recognizing a comfortable and safe "comfort level" of pain for patients. The pre-audit of PACU nursing documents showed that the assessment of pain was noted in terms of presence or absence but not quantified by the use of a measurement standard. After the implementation of a pain standard, results of the post-questionnaires showed changes in behaviors, attitudes, and knowledge that showed significant increases in the use of a numerical or visual pain tool, and an increase in documented evaluation of pain.

Nitric oxide synthase activity in malaria-infected mice

Nitric oxide (NO) is implicated in a variety of major cellular functions including defence from invasion by microbical pathogens. Evidence has been presented suggesting that it is an important mediator of protection in the early non-specific responses to malaria in mice infected with Plasmodium chabaudi (Taylor-Robinson et al. 1993). Other data from in vitro studies on the asexual stages of human parasite Plasmodium falciparum indicated that while nitric oxide itself may not be inhibitory to parasite development, its downstream products do have some anti-plasmodial activity (Rockett et al. 1991) and these could be generated by macrophages (Gyan et al. 1994). Similarly, the sexual phases of both rodent (Motard et al. 1993) and human malaria (Naotunne et al. 1993) are reportedly susceptible to the toxic effects mediated by nitric oxide generated by blood leucocytes in the course of transmission to the mosquito vector.

Hypoxemia/reoxygenation down-regulates interleukin-8-stimulated bactericidal activity of polymorphonuclear neutrophil by differential regulation of CD16 and CD35 mRNA expression

BACKGROUND

The purpose of this study was to determine the effects of hypoxemia/reoxygenation (H/R) on the regulation of interleukin-8 (IL-8)-stimulated human polymorphonuclear neutrophil (PMN) bactericidal activity.

METHODS

Venous human whole blood was rendered normoxic (Pvo2 saturation 60% to 80%), hypoxemic (Pvo2 saturation, less than 15%), or H/R (Pvo2 saturation more than 97%) by dialyzing the blood against a gas mixture of N2/H2/CO2 +/- 30% O2. Two hundred microliter aliquots from each study group were incubated with IL-8 (50 ng/ml) for 45 minutes before fluorescein isothiocyanate-conjugated mouse antihuman CD16 or CD35 antibodies were added. Bactericidal activity was measured with the release of 51Cr from labeled bacteria at 1:1, 5:1, and 10:1 PMN-target ratios. Steady-state mRNA levels for CD16 and CD35 were quantified by Northern blot analyses.

RESULTS

H/R reduced PMN bactericidal activity compared with hypoxemic levels for staphylococcus aureus (48 +/- 5.6 versus 27 +/- 3.3) and Escherichia coli (58 +/- 7.1 versus 33 +/- 4.2). H/R reduced the surface expression of CD16 but not CD35 (mean channel fluorescence CD16, 610 +/- 70 versus 310 +/- 30 for hypoxemia versus H/R; p < 0.01). After H/R was performed, IL-8 decreased mRNA levels for CD16 but not for CD35 compared with levels seen during hypoxemia + IL-8.

CONCLUSIONS

H/R down-regulates IL-8-stimulated PMN bactericidal activity by decreasing steady-state mRNA levels and surface expression of CD16. PMN bactericidal capability after H/R + IL-8 is primarily complementary and not Fc gamma receptor dependent.