Advances in coupling a commercial total organic carbon analyser with an isotope ratio mass spectrometer to determine the isotopic signal of the total dissolved nitrogen pool.

A new method has been developed to analyse 15N of the total dissolved nitrogen (TDN) pool. The method operates on a commercial total organic carbon (TOC) analyser coupled to an elemental analyser/isotope ratio mass spectrometer (EA-IRMS). Nitrogen compounds are combusted to nitric oxide (NO) and nitrogen dioxide (NO2) by high-temperature catalytic oxidation (HTCO), after which the NOx gas is transferred to an EA-IRMS for isotopic nitrogen analysis. The system is described, including five modifications of the system in order to overcome analytical problems. First, flow paths were modified to run both systems on helium as carrier gas, while complete sample oxidation was maintained. Secondly, the catalyst structure was adapted to allow high injection volumes at the given backpressures delivered by the EA system. Thirdly, we installed a Permapure dehumidification system as the standard Peltier element did not satisfy dehumidification requirements. Finally, we prevented the inflow of atmospheric nitrogen into the system. In a final stage, we are planning to automate the coupled system in order to run a continuous batch of up to 60 samples. We have obtained satisfactory results on the accuracy and precision of 180+/-1 per thousand potassium nitrate samples (IAEA, USGS-32). Running a batch of five samples resulted in a mean isotopic value of 178.8 per thousand with a standard deviation of 2.8 per thousand. Some important issues could not yet be addressed here, and will have to be evaluated once the system is running on a continuous base. However, the results appear promising and this system has the potential to become a method for TD15N analysis. An appropriate TD15N analysis method might open new challenges in aquatic and terrestrial ecosystem nitrogen studies, including a more comprehensive study of the dissolved organic nitrogen pool.

The role of distance learning in specialist medical training.

The Quality Assurance Agency for Higher Education (QAA) defines distance learning (DL) as "a way of providing higher education that involves the transfer to the student's location of the materials that form the main basis of study, rather than the student moving to the location of the resource provider".

Community paediatrics moves on--an analysis of changing work patterns 1994-97.

OBJECTIVES: To describe the current clinical workload of the modern community paediatrician; to outline the changes in this role over recent years and examine the reasons for these. DESIGN AND SETTING: The design is a retrospective analysis of data routinely collected for contracting purposes. Nottingham community paediatric service 1994-97 is the setting. MAIN OUTCOME MEASURES: These are the characteristics of patients seen, sources of referral, locations of clinical contact, referral rates by area. RESULTS: 36,710 appointments were offered over the time period studied. The non-attendance rate was 17%. Pre-school children made up the largest group seen. Most referrals were from health visitors (23%) and school nurses (29%). There has been a small but significant increase in the numbers of children seen who have developmental problems and disability, and due to child protection issues between the time periods. There has been a shift in the proportions of children seen in a local health centre referral clinic (9.8% increase during 1994-97) rather than in a school setting. Twice as many children are referred to the community paediatrician from inner city areas than from the surrounding county areas. CONCLUSION: The transfer of child health surveillance to the primary health care team and the increased training of community paediatricians, has resulted in community paediatricians developing an increasingly specialised role particularly in the areas of child growth and development, disability, social and behavioural paediatrics.

Appraisal system for community child health doctors.

An appraisal system for Community Child Health Doctors in Nottingham is described and evaluated. All staff are invited to an annual meeting with their consultant, preparation documents having been filled in by both appraisee and appraiser beforehand. These form the basis of the session, which is predominantly a self-assessment. A written report of the appraisal is produced, with sections on current performance (kept by appraiser and appraise only), training needs, and objectives (copies sent to the academic team and the medical manager). The system was assessed by questionnaires to both appraisers and appraisees. There was general agreement that the system had been adequately explained, and that the preparation documents and the appraisal time were useful. The written report was generally accepted as being a reliable record of the appraisal. Three of the fifteen appraisees were unhappy with the system, feeling it was a negative experience which concentrated on weaknesses. Others made positive comments. It was not always possible to achieve protected time. Some of the reports were delayed. The appraisal system described was found to be acceptable and workable by most people involved. The need for adequate administrative and clerical support was noted.

A randomised single blind trial of a combined mumps measles rubella vaccine to evaluate serological response and reactions in the UK population.

Four hundred and twenty children were randomly assigned to receive either mumps measles rubella (MMR) vaccine (207) or measles vaccine (213) in a single blind study, to investigate the reactogenicity and serology of the MMR vaccine. There was no significant difference between the number of children developing symptoms after MMR vaccination to those developing symptoms after measles vaccination. Both vaccines are associated with a rash, temperature and restlessness five to thirteen days after vaccination. The serological response to measles vaccine was similar in both groups with 92-6% seroconverting with MMR, and 96-8% with measles. Seroconvertion against mumps and rubella with the MMR vaccine was 88% and 96% respectively. This study confirms the safety and efficacy of the MMR vaccine in a UK population.

Routine immunisation of preterm infants.

Fifty one preterm infants (26-36 weeks' gestation) were enrolled in a study of their immunological responses to diphtheria, tetanus, pertussis, and polio antigens eight to 12 weeks after their primary courses had been completed. Samples from 21 infants born at full term were also analysed. Many infants were able to start immunisation at 3 months of age. Premature infants who are immunised as soon as possible after 3 months of age develop adequate antibody responses.

Staffing and structure for paediatric audiology services in hospital and community units.

The component functions of a paediatric audiology service are outlined on the basis of the main broad categories of patient and their requirements, as seen from a 'good practice' standpoint; a service structure is offered in terms of patient flow. This leads to a distinction between the small, specifically medical requirement, and the large, specifically audiological testing requirement. Indications are given of the scale of audiology requiring to be done by community staff not specializing in audiology. Notional incidence figures (and acceptable screen failure rates) allow the number of audiological posts or sessions required for screening and related community paediatric audiology work to be estimated per million population served. This totals about 9.75 FTE professional posts of varying grades per million population plus 1.5 FTE support, but in nearly all circumstances there will be many more incumbents than this, each with diverse other duties. The recommended staffing of audiologists doing hospital-based assessment and rehabilitation work and requiring specialized audiology training totals about 7.0 full-time equivalent (FTE) audiology posts and 2.5 support posts in a hospital paediatric audiology department, per million population; this is above the currently prevailing level of provision. The resource requirements would be raised by the widespread introduction of a non-standard screen (other than for the standard 6 to 9 month screen and the school-entry screen) by about 40% for community services and 15% for consequential increases in hospital services. In hospital units, the staffing will usually be interleaved with that of adult audiology, even where the served population may be large enough (e.g. 0.5 million, three to four paediatric audiology staff) to make a separate section worthwhile. In community units, there does not appear to be a particularly good rationale for community doctors specializing full-time in audiology, although some medical staff time is needed to undertake the specifically medical components. A partial degree of specialization among health visitors (or at least greater audiological training and experience) would probably achieve better performance of screens and simplify the attainment and maintenance of testing standards. Activities in hospital and community units have strong mutual implications: adding an intermediate-age screen to the established first-year and school-entry screens, and adding an at-risk neonatal screen would together increase consequent demands upon hospital paediatric audiology about 35%, although in neither case would the screening activity itself be undertaken in the hospital audiology unit.(ABSTRACT TRUNCATED AT 400 WORDS)

Deprivation hands and feet.

A survey of preschool children in three inner city day nurseries serving deprived areas found 13 children with pink oedematous hands and feet--'deprivation hands and feet'. The children and their families were compared with similar children in the nurseries. Growth and development were poor compared with accepted norms, but not notably different from controls. The families of the affected children were exceptional in being at a considerable social disadvantage. Other children in the families of these children also showed the sign.

Cell-mediated immunity in respiratory syncytial virus disease.

Systemic cell-mediated responses to respiratory syncytial (RS) virus were detected, using a whole blood transformation assay, in 10 of 28 infants and children with RS virus infections during the period 1-14 days postadmission. Cell-mediated responses were unrelated to the age of the patient or the severity of illness. No correlation was found between cellular responses and fourfold or greater rises in antibody titre to RS virus, as determined by a membrane immunofluorescence technique. Patients under 6 months of age had significantly lower levels of IgA and IgG antibody to RS virus compared to older patients, although cell-mediated responses were similar in both groups. The presence of cell-mediated reactivity to RS virus was also demonstrated in 5 of 95 samples of cord blood examined, and cellular responses failed to correlate with the levels of IgG antibody to RS virus.

Pneumothorax in the neonatal period.

The incidence of pneumothorax in the neonatal period is reviewed. Most infants who developed a pneumothorax were undergoing intermittent positive pressure ventilation. The most common underlying pathology associated with pneumothorax was idiopathic respiratory distress syndrome. This was the only condition in which a pneumothorax occurred in spontaneously breathing patients. The development of a pneumothorax was not significantly related to gestational age, birth weight, high ventilator inflation pressure, maximum fractional inspired oxygen concentration or the method of delivery. Evidence is presented to suggest that the development of a pneumothorax is not primarily a complication of ventilation but is due to the more severe pulmonary pathology of infants who require ventilatory assistance. Whatever the mechanism, prompt diagnosis and treatment mean that this common complication does not necessarily increase mortality.

Muscular tension dysphonia.

Muscular tension dysphonia (MTD) is a condition commonly seen in young and middle aged females. It is manifest by excess tension in the paralaryngeal and suprahyoid muscles, an open posterior glottic chink, larynx rise, and frequently mucosal changes on the vocal cords. These mucosal changes are usually fleshy vocal nodules. About 8% of vocal nodules are found in patients not exhibiting features of MTD. The two types of vocal nodules require different therapeutic approaches. One hundred patients out of 500 seen consecutively at the Voice Clinic at the University of British Columbia exhibited the features of MTD. These patients are discussed and an etiology hypothesis is presented.

Wheezing, asthma, and pulmonary dysfunction 10 years after infection with respiratory syncytial virus in infancy.

Of the 180 children admitted to hospitals in Tyneside in the first year of life with proved respiratory syncytial virus lower respiratory tract infection, 130 were seen for review 10 years later and 34 of the remaining 50 children accounted for. Skin tests, lung function tests, and histamine-challenge and exercise tests for bronchial lability were undertaken in over 100 of the index children and a similar number of control children. A total of 55 (42%) of the 130 index children had had further episodes of wheeze, while only 21 (19%) out of 111 controls had ever wheezed; but few (6.2% v 4.5%) had troublesome symptoms at the age of 10. There was a threefold increase in the incidence of bronchial lability in the index children but no excess of atopy. Maximum expiratory air flow was reduced throughout the vital capacity manoeuvre in the index children, even when those with a history of recurrent wheeze were excluded. Results of single-breath nitrogen washout tests were normal, however, suggesting that ventilation was not appreciably uneven, even though expiratory flow was restricted. These differences might have been caused by infection damaging the growing lung but might also be explained by pre-existing differences in the airway, rendering certain children more susceptible to symptomatic infection when first challenged by the virus in infancy.

Breast-feeding and respiratory syncytial virus infection.

The pattern of breast-feeding in 127 infants admitted to hospital with respiratory syncytial virus infection was compared with that in 503 age-matched controls. Thirty per cent of children with infection had been breast-fed compared with 49% of controls. The approximate relative risk of being admitted to hospital with respiratory syncytial virus infection if not breast-fed was 2.2. Several other factors were also considered, including an assessment of maternal care and home environment; the mother's age, marital state, and smoking habits; the number of siblings; and gestation. Adverse factors were all associated with an increased risk of admission with infection, but breast-feeding still appeared to provide protection after controlling for these other factors in turn. These findings provide further support for encouraging mothers to breast-feed their infants and should prompt further studies into the immune status of mothers and into the nature of the protective factors in their breast milk.

Protective effect of inhaled salbutamol powder in children assessed by histamine challenge.

A double-blind placebo-controlled trial of 100, 400, and 800 micrograms inhaled salbutamol powder was conducted on 12 children. The protective effect at 10 minutes, two hours, and four hours was assessed by histamine challenge. At 10 minutes there was good protection with all doses, but by four hours there was significant protection only with 800 micrograms (p less than 0.01). Salbutamol powder may need to be taken at least every four hours for complete protection. There was a dose-related effect with a single dose of up to 800 micrograms; increasing the dose increased the effect and duration of action. Currently advertised dose regimens of salbutamol powder for children (200 micrograms three or four times a day) are apparently submaximal. Histamine challenge is a satisfactory method of assessing the proective effect of a drug in asthmatic children.

Secretion of respiratory syncytial virus inhibitors and antibody in human milk throughout lactation.

Neutralising inhibitors to respiratory syncytial (RS) virus have been demonstrated in the whey of most samples of human milk tested. Although high titres were secreted in colostra of some mothers (1/10-1/2,560; median 1/40) inhibitor levels in milk collected after the first week of lactation were uniformly low (median 1/10). High neutralising titres correlated with high colostral levels of specific antiviral IgA but, unlike neutralising activity, IgA antiviral antibody persisted in the milk of only four of 18 mothers. Similarly, antiviral IgG and IgM antibodies were not generally detected after the first post-partum week. Differences in antibody secretion among mothers did not correlate with differences in total protein or total immunoglobulin secretion, and appeared to reflect maternal immune status. In one mother a marked rise in specific antiviral IgA and IgG secretions during the second and third months of lactation suggested a response to virus infection. The relevance of maternal immunity and colostral and milk antiviral antibody to protection of breast-fed babies from RS-virus bronchiolitis is discussed.

Viruses and acute abdominal pain in childhood.

Children aged at least 4 years admitted to hospital with acute abdominal pain, excluding appendicitis, were investigated for the presence of viruses. Out of 181 children 29 were found with viruses of whom 18 had nonspecific abdominal pain. Eight others were found to have virus-like particles on electron microscopical examination of their faeces. Virus infections contribute to a small extent to nonspecific abdominal pain in childhood, but in many cases the cause remains unknown.

Aneurysmal bone cyst: a report of three cases.

Three children presenting with aneurysmal bone cysts are described. The first patient was 10 months old with a cyst of the scapula. The second was more typical but his cyst was treated initially as a malignant tumour. In the third child the second cervical vertebra was affected which posed considerable problems of management; it was treated by radiotherapy. Despite the problems all 3 children have made a good recovery.