Wales Infants' and childreN's Genome Service (WINGS): providing rapid genetic diagnoses for unwell children

INTRODUCTION

This study reviews the first 3 years of delivery of the first National Health Service (NHS)-commissioned trio rapid whole genome sequencing (rWGS) service for acutely unwell infants and children in Wales.

METHODS

Demographic and phenotypic data were prospectively collected as patients and their families were enrolled in the Wales Infants' and childreN's Genome Service (WINGS). These data were reviewed alongside trio rWGS results.

RESULTS

From April 2020 to March 2023, 82 families underwent WINGS, with a diagnostic yield of 34.1%. The highest diagnostic yields were noted in skeletal dysplasias, neurological or metabolic phenotypes. Mean time to reporting was 9 days.

CONCLUSION

This study demonstrates that trio rWGS is having a positive impact on the care of acutely unwell infants and children in an NHS setting. In particular, the study shows that rWGS can be applied in an NHS setting, achieving a diagnostic yield comparable with the previously published diagnostic yields achieved in research settings, while also helping to improve patient care and management.

Divergent rainforest tree microbiomes between phases of the monsoon cycle, host plants and tissues

The Australian Monsoon Tropics (AMT) contain some of the most biodiverse forests on the continent. Little is known about the dynamics of rainforest plant microbiomes in general, and there have been no community-level studies on Australian rainforest endophytes, their seasonality, tissue and host specificity. We tested whether community composition of tropical tree endophytes (fungi and bacteria) differs: (i) at different points during a monsoon cycle, (ii) between leaf and stem tissues, (iii) between forest microclimates (gully/ridge), and between (iv) host plant species, and (v) host plant clade, using amplicon sequencing of the bacterial 16S and fungal ITS2 gene regions. Results indicated that the composition of rainforest plant microbiomes differs between wet and dry seasons, which may be explained by physiological shifts in host plants due to annual climate fluctuations from mesic to xeric. Endophyte microbiomes differed between leaves and stems. Distinct fungal communities were associated with host species and clades, with some trees enriched in a number of fungal taxa compared to host plants in other clades. Diversity of bacterial endophytes in plant stems increased in the dry season. We conclude that the microbiomes of tropical plants are responsive to monsoonal climate variation, are highly compartmentalised between plant tissues, and may be partly shaped by the relatedness of their host plants.

Practical considerations for laboratories: Implementing a holistic quality management system

A laboratory quality management system (LQMS) is an essential element for the effective operation of research, clinical, testing, or production/manufacturing laboratories. As technology continues to rapidly advance and new challenges arise, laboratories worldwide have responded with innovation and process changes to meet the continued demand. It is critical for laboratories to maintain a robust LQMS that accommodates laboratory activities (e.g., basic and applied research; regulatory, clinical, or proficiency testing), records management, and a path for continuous improvement to ensure that results and data are reliable, accurate, timely, and reproducible. A robust, suitable LQMS provides a framework to address gaps and risks throughout the laboratory path of workflow that could potentially lead to a critical error, thus compromising the integrity and credibility of the institution. While there are many LQMS frameworks (e.g., a model such as a consensus standard, guideline, or regulation) that may apply, ensuring that the appropriate framework is adopted based on the type of work performed and that key implementation steps are taken is important for the long-term success of the LQMS and for the advancement of science. Ultimately, it ensures accurate results, efficient operations, and increased credibility, enabling protection of public health and safety. Herein, we explore LQMS framework options for each identified laboratory category and discuss prerequisite considerations for implementation. An analysis of frameworks' principles and conformity requirements demonstrates the extent to which they address basic components of effective laboratory operations and guides optimal implementation to yield a holistic, sustainable framework that addresses the laboratory's needs and the type of work being performed.

nSeP: immune and metabolic biomarkers for early detection of neonatal sepsis-protocol for a prospective multicohort study

INTRODUCTION

Diagnosing neonatal sepsis is heavily dependent on clinical phenotyping as culture-positive body fluid has poor sensitivity, and existing blood biomarkers have poor specificity.A combination of machine learning, statistical and deep pathway biology analyses led to the identification of a tripartite panel of biologically connected immune and metabolic markers that showed greater than 99% accuracy for detecting bacterial infection with 100% sensitivity. The cohort study described here is designed as a large-scale clinical validation of this previous work.

METHODS AND ANALYSIS

This multicentre observational study will prospectively recruit a total of 1445 newborn infants (all gestations)-1084 with suspected early-or late-onset sepsis, and 361 controls-over 4 years. A small volume of whole blood will be collected from infants with suspected sepsis at the time of presentation. This sample will be used for integrated transcriptomic, lipidomic and targeted proteomics profiling. In addition, a subset of samples will be subjected to cellular phenotype and proteomic analyses. A second sample from the same patient will be collected at 24 hours, with an opportunistic sampling for stool culture. For control infants, only one set of blood and stool sample will be collected to coincide with clinical blood sampling. Along with detailed clinical information, blood and stool samples will be analysed and the information will be used to identify and validate the efficacy of immune-metabolic networks in the diagnosis of bacterial neonatal sepsis and to identify new host biomarkers for viral sepsis.

ETHICS AND DISSEMINATION

The study has received research ethics committee approval from the Wales Research Ethics Committee 2 (reference 19/WA/0008) and operational approval from Health and Care Research Wales. Submission of study results for publication will involve making available all anonymised primary and processed data on public repository sites.

TRIAL REGISTRATION NUMBER

NCT03777670.

Addition of docetaxel to hormonal therapy in low- and high-burden metastatic hormone sensitive prostate cancer: long-term survival results from the STAMPEDE trial

BACKGROUND

STAMPEDE has previously reported that the use of upfront docetaxel improved overall survival (OS) for metastatic hormone naïve prostate cancer patients starting long-term androgen deprivation therapy. We report on long-term outcomes stratified by metastatic burden for M1 patients.

METHODS

We randomly allocated patients in 2 : 1 ratio to standard-of-care (SOC; control group) or SOC + docetaxel. Metastatic disease burden was categorised using retrospectively-collected baseline staging scans where available. Analysis used Cox regression models, adjusted for stratification factors, with emphasis on restricted mean survival time where hazards were non-proportional.

RESULTS

Between 05 October 2005 and 31 March 2013, 1086 M1 patients were randomised to receive SOC (n = 724) or SOC + docetaxel (n = 362). Metastatic burden was assessable for 830/1086 (76%) patients; 362 (44%) had low and 468 (56%) high metastatic burden. Median follow-up was 78.2 months. There were 494 deaths on SOC (41% more than the previous report). There was good evidence of benefit of docetaxel over SOC on OS (HR = 0.81, 95% CI 0.69-0.95, P = 0.009) with no evidence of heterogeneity of docetaxel effect between metastatic burden sub-groups (interaction P = 0.827). Analysis of other outcomes found evidence of benefit for docetaxel over SOC in failure-free survival (HR = 0.66, 95% CI 0.57-0.76, P < 0.001) and progression-free survival (HR = 0.69, 95% CI 0.59-0.81, P < 0.001) with no evidence of heterogeneity of docetaxel effect between metastatic burden sub-groups (interaction P > 0.5 in each case). There was no evidence that docetaxel resulted in late toxicity compared with SOC: after 1 year, G3-5 toxicity was reported for 28% SOC and 27% docetaxel (in patients still on follow-up at 1 year without prior progression).

CONCLUSIONS

The clinically significant benefit in survival for upfront docetaxel persists at longer follow-up, with no evidence that benefit differed by metastatic burden. We advocate that upfront docetaxel is considered for metastatic hormone naïve prostate cancer patients regardless of metastatic burden.

Increased surfactant protein-D levels in the airways of preterm neonates with sepsis indicated responses to infectious challenges

AIM

Sepsis is multifactorial and potentially devastating for preterm neonates. Changes in surfactant protein-D (SP-D), phosphatidylcholine (PC) and PC molecular species during infection may indicate innate immunity or inflammation during sepsis. We aimed to compare these important pulmonary molecules in ventilated neonates without or with sepsis.

METHODS

Endotracheal aspirates were collected from preterm neonates born at 23-35 weeks and admitted to the neonatal intensive care unit at the John Radcliffe Hospital, Oxford, UK, from October 2000 to March 2002. Samples were collected at one day to 30 days and analysed for SP-D, total PC and PC molecular species concentrations using enzyme-linked immunosorbent assay and mass spectrometry.

RESULTS

We found that 8/54 (14.8%) neonates developed sepsis. SP-D (p < 0.0001), mono- and di-unsaturated PC were significantly increased (p = 0.05), and polyunsaturated PC was significantly decreased (p < 0.01) during sepsis compared to controls. SP-D:PC ratios were significantly increased during sepsis (p < 0.001), and SP-D concentrations were directly related to gestational age in neonates with sepsis (r²  = 0.389, p < 0.01).

CONCLUSION

Increased SP-D levels and changes in PC molecular species during sepsis were consistent with direct or indirect pulmonary inflammatory processes. Very preterm neonates we able to mount an acute inflammatory innate immune response to infectious challenges, despite low levels of surfactant proteins at birth.

Tuberculosis in HIV-infected children in Europe, Thailand and Brazil: paediatric TB-HIV EuroCoord study

SETTING

Centres participating in the Paediatric European Network for Treatment of AIDS (PENTA), including Thailand and Brazil.

OBJECTIVE

To describe the incidence, presentation, treatment and treatment outcomes of tuberculosis (TB) in human immunodeficiency virus (HIV) infected children.

DESIGN

Observational study of TB diagnosed in HIV-infected children in 2011-2013.

RESULTS

Of 4265 children aged <16 years, 127 (3%) were diagnosed with TB: 6 (5%) in Western Europe, 80 (63%) in Eastern Europe, 27 (21%) in Thailand and 14 (11%) in Brazil, with estimated TB incidence rates of respectively 239, 982, 1633 and 2551 per 100 000 person-years (py). The majority (94%) had acquired HIV perinatally. The median age at TB diagnosis was 6.8 years (interquartile range 3.0-11.5). Over half (52%) had advanced/severe World Health Organization stage immunodeficiency; 67 (53%) were not on antiretroviral therapy (ART) at TB diagnosis. Preventive anti-tuberculosis treatment was given to 23% (n = 23) of 102 children diagnosed with HIV before TB. Eleven children had unfavourable TB outcomes: 4 died, 5 did not complete treatment, 1 had recurrent TB and 1 had an unknown outcome. In univariable analysis, previous diagnosis of acquired immune-deficiency syndrome, not being virologically suppressed on ART at TB diagnosis and region (Brazil) were significantly associated with unfavourable TB outcomes.

CONCLUSION

Most TB cases were from countries with high TB prevalence. The majority (91%) had favourable outcomes. Universal ART and TB prophylaxis may reduce missed opportunities for TB prevention.

Case finding for chronic obstructive pulmonary disease in people attending long-term condition clinics in primary care

Despite increased interest and awareness of chronic obstructive pulmonary disease (COPD), nearly half of the people with COPD remain undiagnosed. Inviting people at risk for screening is unlikely to be effective as many will not attend. Co-morbidities are common in people with COPD but COPD is also a comorbidity of other long-term conditions and people with these conditions are under regular review in primary care clinics. This study aimed to develop a pilot programme to case find people with COPD among patients attending other long-term clinics in primary care. Twenty-three general practices were recruited to participate in South West England. All current or ex-smokers aged ≥35 attending a long-term condition clinic who were not known to have COPD were asked to complete a questionnaire designed to help identify people with COPD and to perform microspirometry. Practices were asked to collect data on up to 100 patients. One thousand three hundred and thirty-three patients were assessed. Four hundred and ten people (31%) were current smokers. Six hundred and thirteen (46%) had high questionnaire scores and 287 (22%) of these also had a forced expiratory volume in 1 second (FEV1) below the lower limit of normal (LLN). The mean FEV1 in these patients was 59.0% of predicted (range 22-79.0%). Two hundred and twenty-four had an FEV1 between 50% and 80% of predicted, 50 had an FEV1 between 30% and 50% of predicted. One hundred and sixteen (40%) of the people with an FEV1 below the LLN were still smoking and 55 accepted referral to cessation services. A total of 56% of the other smokers assessed but not thought to have COPD also accepted referral. Assessing symptoms and performing microspirometry in people attending long-term condition clinics in primary care is feasible and has a high yield of identifying people likely to have previously undiagnosed COPD.

Study protocol for an evaluation of the effectiveness of 'care bundles' as a means of improving hospital care and reducing hospital readmission for patients with chronic obstructive pulmonary disease (COPD)

BACKGROUND

Chronic Obstructive Pulmonary Disease is one of the commonest respiratory diseases in the United Kingdom, accounting for 10% of unplanned hospital admissions each year. Nearly a third of these admitted patients are re-admitted to hospital within 28 days of discharge. Whilst there is a move within the NHS to ensure that people with long-term conditions receive more co-ordinated care, there is little research evidence to support an optimum approach to this in COPD. This study aims to evaluate the effectiveness of introducing standardised packages of care i.e. care bundles, for patients with acute exacerbations of COPD as a means of improving hospital care and reducing re-admissions.

METHODS / DESIGN

This mixed-methods evaluation will use a controlled before-and-after design to examine the effect of, and costs associated with, implementing care bundles for patients admitted to hospital with an acute exacerbation of COPD, compared with usual care. It will quantitatively measure a range of patient and organisational outcomes for two groups of hospitals - those who deliver care using COPD care bundles, and those who deliver care without the use of COPD care bundles. These care bundles may be provided for patients with COPD following admission, prior to discharge or at both points in the care pathway. The primary outcome will be re-admission to hospital within 28 days of discharge, although the study will additionally investigate a number of secondary outcomes including length of stay, total bed days, in-hospital mortality, costs of care and patient / carer experience. A series of nested qualitative case studies will explore in detail the context and process of care as well as the impact of COPD bundles on staff, patients and carers.

DISCUSSION

The results of the study will provide information about the effectiveness of care bundles as a way of managing in-hospital care for patients with an acute exacerbation of COPD. Given the number of unplanned hospital admissions for this patient group and their rate of subsequent re-admission, it is hoped that this evaluation will make a timely contribution to the evidence on care provision, to the benefit of patients, clinicians, managers and policy-makers.

TRIAL REGISTRATION

International Standard Randomised Controlled Trials - ISRCTN13022442 - 11 February 2015.

Comparison of diagnostic clinical samples and environmental sampling for enterovirus and parechovirus surveillance in Scotland, 2010 to 2012

Human enteroviruses (EV) and parechoviruses (HPeV) within the family Picornaviridae are the most common causes of viral central nervous system (CNS)-associated infections including meningitis and neonatal sepsis-like disease. The frequencies of EV and HPeV types identified in clinical specimens collected in Scotland over an eight-year period were compared to those identified in sewage surveillance established in Edinburgh. Of the 35 different EV types belonging to four EV species (A to D) and the four HPeV types detected in this study, HPeV3 was identified as the most prevalent picornavirus in cerebrospinal fluid samples, followed by species B EV. Interestingly, over half of EV and all HPeV CNS-associated infections were observed in young infants (younger than three months). Detection of species A EV including coxsackievirus A6 and EV71 in clinical samples and sewage indicates that these viruses are already widely circulating in Scotland. Furthermore, species C EV were frequently identified EV in sewage screening but they were not present in any of 606 EV-positive clinical samples studied, indicating their likely lower pathogenicity. Picornavirus surveillance is important not only for monitoring the changing epidemiology of these infections but also for the rapid identification of spread of emerging EV and/or HPeV types.

Recombination dynamics of human parechoviruses: investigation of type-specific differences in frequency and epidemiological correlates

Human parechoviruses (HPeVs) are highly prevalent RNA viruses classified in the family Picornaviridae. Several antigenically distinct types circulate in human populations worldwide, whilst recombination additionally contributes to the genetic heterogeneity of the virus. To investigate factors influencing the likelihood of recombination and to compare its dynamics among types, 154 variants collected from four widely geographically separated referral centres (UK, The Netherlands, Thailand and Brazil) were typed by VP3/VP1 amplification/sequencing with recombination groups assigned by analysis of 3Dpol sequences. HPeV1B and HPeV3 were the most frequently detected types in each referral region, but with marked geographical differences in the frequencies of different recombinant forms (RFs) of types 1B, 5 and 6. HPeV1B showed more frequent recombination than HPeV3, in terms both of evolutionary divergence and of temporal/geographical indicators of population separation. HPeV1 variants showing between 10 and 20% divergence in VP3/VP1 almost invariably fell into different recombination groups, compared with only one-third of similarly divergent HPeV3 variants. Substitution rates calculated by beast in the VP3/VP1 region of HPeV1 and HPeV3 allowed half-lives of the RFs of 4 and 20 years, respectively, to be calculated, estimates fitting closely with their observed lifespans based on population sampling. The variability in recombination dynamics between HPeV1B and HPeV3 offers an intriguing link with their markedly different seasonal patterns of transmission, age distributions of infection and clinical outcomes. Future investigation of the epidemiological and biological opportunities and constraints on intertypic recombination will provide more information about its influence on the longer term evolution and pathogenicity of parechoviruses.

Urban/rural differences in diet and atopy in South Africa

BACKGROUND

There are large differences in the prevalence of atopic disease between urban and rural areas of developing countries, without good explanation. Diet has been associated with atopic disease, but studies of specific nutrients are contradictory, cross-sectional studies often being unsupported by trials. We investigated diet as an explanation for the difference in the prevalence of atopy between urban and rural areas in South Africa.

METHODS

A cross-sectional analysis of food frequency questionnaires and allergen skin tests from 698 children aged 8-13 years, recruited from 24 schools in Cape Province, South Africa, who were taking part in a case-control study of exercise-induced bronchospasm. Food frequency data were analysed with a principal components analysis (PCA).

RESULTS

The first two principal components of diet explained 25% of the variance, and discriminated almost perfectly between urban and rural subjects. The 'urban' component of diet was strongly associated with positive skin tests even after adjusting for urban residence. There were no significant associations between individual foods or nutrients and positive skin tests, allowing for multiple testing.

CONCLUSIONS

Diet explains part of the difference in prevalence between urban and rural areas. The ability to demonstrate this using PCA, but not by exhaustive analysis of all foods, reflects the value of reducing the number of dietary dimensions. The number of foods and nutrients which can be assessed, and the possibility of confounding and effect modification, make it difficult to identify the features of diet most directly implicated in disease. This may explain inconsistencies in dietary studies.

The role for S-carboxymethylcysteine (carbocisteine) in the management of chronic obstructive pulmonary disease

Prescription of mucoactive drugs for chronic obstructive pulmonary disease (COPD) is increasing. This development in clinical practice arises, at least in part, from a growing understanding of the important role that exacerbation frequency, systemic inflammation and oxidative stress play in the pathogenesis of respiratory disease. S-carboxymethylcysteine (carbocisteine) is the most frequently prescribed mucoactive agent for long-term COPD use in the UK. In addition to its mucoregulatory activity, carbocisteine exhibits free-radical scavenging and anti-inflammatory properties. These characteristics have stimulated interest in the potential that this and other mucoactive drugs may offer for modification of the disease processes present in COPD. This article reviews the pharmacology, in vivo and in vitro properties, and clinical trial evidence for carbocisteine in the context of guidelines for its use and the current understanding of the pathogenic processes that underlie COPD.

Surface heating by transvaginal transducers

OBJECTIVE

This safety study was designed to investigate tissue heating close to the surface of transvaginal ultrasound transducers, with the objective of assessing the validity of manufacturing safety standards set by the International Electrotechnical Commission (IEC).

METHODS

The transducers investigated in this study were held in contact with a layered soft-tissue mimicking material (TMM), and the temperature increase was measured at various depths using a miniature thermocouple. The temperature rise at 200 s was recorded, and the measured profiles of temperature rise with depth were compared with profiles predicted from both analytical and numeric models. Two transvaginal transducers of different manufacturers were investigated, operating in B-mode imaging, color-flow imaging and pulsed Doppler modes, using scanner settings giving acoustic output power towards the upper end of that available.

RESULTS

The greatest heating always occurred at the interface between the transducer and the TMM, and it reduced to about 0.1 times the surface temperature rise at a depth of 1 cm. A local maximum was observed in pulsed Doppler mode. A three-dimensional finite-element model which accounted for transducer dimensions gave a better prediction of temperature increase than a simple analytical model. The temperature profiles were compared with the depth of fetal tissue measured from a small survey of clinical scans.

CONCLUSIONS

It is provisionally concluded that the transducer surface temperature rise of 6 degrees C allowed to manufacturers by the IEC may give rise to an associated worst-case contribution to temperature rise due to the transducer, in fetal tissue, of between 0.5 and 1 degrees C at 1-cm depth. The contribution to tissue heating at 2 cm and deeper is negligible. Published by John Wiley & Sons, Ltd.

Chlamydia trachomatis infection in a colposcopy unit: an audit of a fast track referral system for infected patients to a genitourinary medicine department and a survey of patients' demography, clinical findings and partner details

We had previously shown that screening and treating patients for Chlamydia trachomatis prior to termination of pregnancy significantly reduces postoperative morbidity. Our success led us to consider screening women attending our colposcopy unit and this was introduced in 1998. However, it became apparent that a formal protocol was needed for managing women who had positive results to ensure that all patients and their partners were adequately treated. An interdepartmental protocol was devised for fast track referral of infected patients to the Genitourinary Medicine (GUM) clinic Health Advisor who arranged immediate treatment and partner notification. A re-audit, presented here, has shown that the introduction of the protocol has resulted in all infected patients receiving adequate treatment and partner notification with minimal use of doctor time or disruption of routine GUM services. We suggest that our system is effective and could be extended to other clinics where chlamydia screening is carried out.

Dementia in people with Down's syndrome

OBJECTIVES

To determine the prevalence of dementia in an Irish sample of people with Down's syndrome (DS) and to examine associated clinical characteristics of dementia in this group.

METHOD

285 people with DS (Age 35-74 years, mean age +/- SD 46.5 +/- 8.2 years) were included in this cross-sectional study. The diagnosis of dementia was made using modified DSMIV criteria. Cognitive tests used were the Down's syndrome Mental Status Examination (DSMSE), Test for Severe Impairment (TSI) and adaptive function was measured by the Daily Living Skills Questionnaire (DLSQ).

RESULTS

The overall prevalence of dementia was 13.3%. The presence of dementia was associated with epilepsy, myoclonus, and head injury. The demented DS group were significantly older (n = 38, mean age 54.7 years SD +/- 7.5) than the non-demented (n = 246, mean age 45.6, SD +/- 7.3). The TSI and DLSQ had a satisfactory spread of scores without 'floor' or 'ceiling' effects in people with moderate and severe learning disability. Median scores in demented versus the non-demented groups were significantly different for each measure of function.

CONCLUSIONS

Dementia had a prevalence of 13.3% and occurred at a mean age of 54.7 years. The combination of DLSQ score, age and presence of epilepsy were found to predict presence of dementia.

Presenilin 1 and alpha-1-antichymotrypsin polymorphisms in Down syndrome: no effect on the presence of dementia

As people with Down syndrome (DS) age, they are at greater risk for Alzheimer disease (AD) than the general population. It has been suggested that polymorphisms at the genes for presenilin-1 (PS-1) and alpha-1-antichymotrypsin (ACT) confer an increased risk for AD in the general population, and therefore potentially to AD in people with DS. We obtained DNA from 231 individuals with DS and 233 population controls. People with DS were evaluated for dementia. Allele frequencies at PS-1 and ACT polymorphisms in people with DS were compared to those in age-matched controls. There were no frequency differences between the control sample and DS sample for PS-1 or ACT alleles or genotypes. Similarly, there were no differences in allele frequencies between the demented and age-matched non-demented DS samples. However a higher frequency of PS-1 heterozygotes in the demented DS group was noted. We conclude that unlike the general population, neither PS-1 nor ACT polymorphisms appear to have a similar detrimental effect on dementia in DS. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 88:616-620, 1999.

Recombinant DNase in cystic fibrosis: a protocol for targeted introduction through n-of-1 trials. Scottish Cystic Fibrosis Group

Nebulized recombinant human deoxyribonuclease (DNase) reduces sputum viscosity and improves lung function in some cystic fibrosis patients, but individual responses are unpredictable. The aim of this study was to investigate how DNase can be targeted to those cystic fibrosis patients who would benefit most. The Scottish Cystic Fibrosis Group agreed on a randomized, double-blind, placebo-controlled n-of-1 assessment protocol. Patients underwent a maximum of three 4-week assessment periods (2 weeks saline, 2 weeks DNase each). Measurements performed at hospital (exercise, oximetry and spirometry) and home (symptom scores) were used to derive a scoring system to discriminate maximally between DNase and placebo effects. The data on 89 4-week assessments in 52 patients were reported. Twenty-four patients have completed the assessment process (12 responders and 12 nonresponders) to date. Forced expiratory volume in one second (FEVI) was the best discriminator of response, rising by >200 mL after DNase in 33 of 89 (37%) assessments compared with 3 of 89 (3%) after saline. N-of-1 trials, while laborious, permitted genuine treatment effects to be quantified within individuals with confidence, permitting appropriate treatment targeting. This provides a model of how other new expensive therapies may be introduced to maximize patient benefit.

Two regions of an avian hepadnavirus RNA pregenome are required in cis for encapsidation

We have constructed a series of deletion mutants spanning the genome of duck hepatitis B virus in order to determine which regions of the viral genome are required in cis for packaging of the pregenome into capsid particles. Deletion of sequences within either of two nonadjacent regions prevented replication of the mutant viral genomes expressed in a permissive avian hepatoma cell line in the presence of functionally active viral core and P proteins. Extraction of RNA from cells transfected with these replication-defective mutants showed that the mutants retained the capacity to be transcribed into a pregenomic-size viral RNA, but that these RNA species were not packaged into viral capsids. The two regions defined by these deletions are located 36 to 126 (region I) and 1046 to 1214 (region II) nucleotides downstream of the 5' end of the pregenome and contain sequences which are required in cis for encapsidation of the duck hepatitis B virus pregenome.

Adaptation to movement in right and left visual fields

102 subjects reported on movement aftereffects (MAEs) produced by stimuli presented in the left or right visual field. MAEs were both faster and longer when the stimuli were presented in the right visual field. Possible reasons for the asymmetry are discussed.

Gestational diabetes

The perinatal morbidity and mortality associated with gestational diabetes can be significantly reduced when cases are recognized and closely monitored. There is much controversy about the diagnosis of gestational diabetes and the practicality of universal screening.