Features of the highway road network that generate or retain tyre wear particles

The environmental accumulation of microplastics poses a formidable global challenge, with tyre wear particles (TWPs) emerging as major and potentially harmful contributors to this particulate pollution. A critical pathway for TWPs to aquatic environments is via road drainage. While drainage assets are employed worldwide, their effectiveness in retaining microplastics of highly variable densities (TWP ~ 1-2.5 g cm3) remains unknown. This study examines their ability to impede the transfer of TWPs from the UK Strategic Road Network (SRN) to aquatic ecosystems. Samples were collected from the influent, effluent and sediments of three retention ponds and three wetlands. The rate of TWP generation is known to vary in response to vehicle speed and direction. To ascertain the significance of this variability, we further compared the mass of TWPs in drainage from curved and straight sections of the SRN across eight drainage outfalls. Pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) was used to quantify tyre wear using benzothiazole as a molecular marker for TWPs (with an internal standard benzothiazole-D4). Tyre wear was present in drainage from the SRN at concentrations of 2.86 ± 6 mg/L and was found within every sample analysed. Drainage from curved sections of the SRN contained on average a 40% greater TWP mass than straight sections but this was not significant. The presence of wetlands and retention ponds generally led to a reduction in TWP mass (74.9% ± 8.2). This effect was significant for retention ponds but not for wetlands; most probably due to variability among sites and sampling occasions. Similar drainage assets are used on a global scale; hence our results are of broad relevance to the management of TWP pollution.

Biogeochemical consequences of a changing Arctic shelf seafloor ecosystem

Unprecedented and dramatic transformations are occurring in the Arctic in response to climate change, but academic, public, and political discourse has disproportionately focussed on the most visible and direct aspects of change, including sea ice melt, permafrost thaw, the fate of charismatic megafauna, and the expansion of fisheries. Such narratives disregard the importance of less visible and indirect processes and, in particular, miss the substantive contribution of the shelf seafloor in regulating nutrients and sequestering carbon. Here, we summarise the biogeochemical functioning of the Arctic shelf seafloor before considering how climate change and regional adjustments to human activities may alter its biogeochemical and ecological dynamics, including ecosystem function, carbon burial, or nutrient recycling. We highlight the importance of the Arctic benthic system in mitigating climatic and anthropogenic change and, with a focus on the Barents Sea, offer some observations and our perspectives on future management and policy.

Quantifying the release of tyre wear particles to the marine environment via multiple pathways

Desk-based studies have suggested tyre wear particles contribute a substantial portion of microplastic emissions to the environment, yet few empirical studies report finding tyre wear. Samples were collected from three pathways to the marine environment: atmospheric deposition, treated wastewater effluent, and untreated surface runoff. Pyrolysis coupled to gas chromatography-mass spectrometry was used to detect benzothiazole, a molecular marker for tyres. Benzothiazole was detected in each pathway, emitting tyre wear in addition to other sources of microplastics. Release via surface water drainage was the principle pathway in the regions examined. Laboratory tests indicated larger particles likely settle close to their entry points, whereas smaller particles have potential for longer-range transport and dispersal. The previous lack of reports are likely a consequence of inadequate methods of detection, rather than a low environmental presence. Further work is required to establish distribution, transport potential, and potential impacts once within the marine environment.

Does Arctic warming reduce preservation of organic matter in Barents Sea sediments?

Over the last few decades, the Barents Sea experienced substantial warming, an expansion of relatively warm Atlantic water and a reduction in sea ice cover. This environmental change forces the entire Barents Sea ecosystem to adapt and restructure and therefore changes in pelagic-benthic coupling, organic matter sedimentation and long-term carbon sequestration are expected. Here we combine new and existing organic and inorganic geochemical surface sediment data from the western Barents Sea and show a clear link between the modern ecosystem structure, sea ice cover and the organic carbon and CaCO₃ contents in Barents Sea surface sediments. Furthermore, we discuss the sources of total and reactive iron phases and evaluate the spatial distribution of organic carbon bound to reactive iron. Consistent with a recent global estimate we find that on average 21.0 ± 8.3 per cent of the total organic carbon is associated to reactive iron (fOC-Fe_R) in Barents Sea surface sediments. The spatial distribution of fOC-Fe_R, however, seems to be unrelated to sea ice cover, Atlantic water inflow or proximity to land. Future Arctic warming might, therefore, neither increase nor decrease the burial rates of iron-associated organic carbon. However, our results also imply that ongoing sea ice reduction and the associated alteration of vertical carbon fluxes might cause accompanied shifts in the Barents Sea surface sedimentary organic carbon content, which might result in overall reduced carbon sequestration in the future. This article is part of the theme issue 'The changing Arctic Ocean: consequences for biological communities, biogeochemical processes and ecosystem functioning'.

Benthic-pelagic coupling in the Barents Sea: an integrated data-model framework

The Barents Sea is experiencing long-term climate-driven changes, e.g. modification in oceanographic conditions and extensive sea ice loss, which can lead to large, yet unquantified disruptions to ecosystem functioning. This key region hosts a large fraction of Arctic primary productivity. However, processes governing benthic and pelagic coupling are not mechanistically understood, limiting our ability to predict the impacts of future perturbations. We combine field observations with a reaction-transport model approach to quantify organic matter (OM) processing and disentangle its drivers. Sedimentary OM reactivity patterns show no gradients relative to sea ice extent, being mostly driven by seafloor spatial heterogeneity. Burial of high reactivity, marine-derived OM is evident at sites influenced by Atlantic Water (AW), whereas low reactivity material is linked to terrestrial inputs on the central shelf. Degradation rates are mainly driven by aerobic respiration (40-75%), being greater at sites where highly reactive material is buried. Similarly, ammonium and phosphate fluxes are greater at those sites. The present-day AW-dominated shelf might represent the future scenario for the entire Barents Sea. Our results represent a baseline systematic understanding of seafloor geochemistry, allowing us to anticipate changes that could be imposed on the pan-Arctic in the future if climate-driven perturbations persist. This article is part of the theme issue 'The changing Arctic Ocean: consequences for biological communities, biogeochemical processes and ecosystem functioning'.

Transformation of organic matter in a Barents Sea sediment profile: coupled geochemical and microbiological processes

Process-based, mechanistic investigations of organic matter transformation and diagenesis directly beneath the sediment-water interface (SWI) in Arctic continental shelves are vital as these regions are at greatest risk of future change. This is in part due to disruptions in benthic-pelagic coupling associated with ocean current change and sea ice retreat. Here, we focus on a high-resolution, multi-disciplinary set of measurements that illustrate how microbial processes involved in the degradation of organic matter are directly coupled with inorganic and organic geochemical sediment properties (measured and modelled) as well as the extent/depth of bioturbation. We find direct links between aerobic processes, reactive organic carbon and highest abundances of bacteria and archaea in the uppermost layer (0-4.5 cm depth) followed by dominance of microbes involved in nitrate/nitrite and iron/manganese reduction across the oxic-anoxic redox boundary (approx. 4.5-10.5 cm depth). Sulfate reducers dominate in the deeper (approx. 10.5-33 cm) anoxic sediments which is consistent with the modelled reactive transport framework. Importantly, organic matter reactivity as tracked by organic geochemical parameters (n-alkanes, n-alkanoic acids, n-alkanols and sterols) changes most dramatically at and directly below the SWI together with sedimentology and biological activity but remained relatively unchanged across deeper changes in sedimentology. This article is part of the theme issue 'The changing Arctic Ocean: consequences for biological communities, biogeochemical processes and ecosystem functioning'.

Cretaceous dinosaur bone contains recent organic material and provides an environment conducive to microbial communities

Fossils were thought to lack original organic molecules, but chemical analyses show that some can survive. Dinosaur bone has been proposed to preserve collagen, osteocytes, and blood vessels. However, proteins and labile lipids are diagenetically unstable, and bone is a porous open system, allowing microbial/molecular flux. These 'soft tissues' have been reinterpreted as biofilms. Organic preservation versus contamination of dinosaur bone was examined by freshly excavating, with aseptic protocols, fossils and sedimentary matrix, and chemically/biologically analyzing them. Fossil 'soft tissues' differed from collagen chemically and structurally; while degradation would be expected, the patterns observed did not support this. 16S rRNA amplicon sequencing revealed that dinosaur bone hosted an abundant microbial community different from lesser abundant communities of surrounding sediment. Subsurface dinosaur bone is a relatively fertile habitat, attracting microbes that likely utilize inorganic nutrients and complicate identification of original organic material. There exists potential post-burial taphonomic roles for subsurface microorganisms.

Exploring the geochemical distribution of organic carbon in early land plants: a novel approach

Terrestrialization depended on the evolution of biosynthetic pathways for biopolymers including lignin, cutin and suberin, which were concentrated in specific tissues, layers or organs such as the xylem, cuticle and roots on the submillimetre scale. However, it is often difficult, or even impossible especially for individual cells, to resolve the biomolecular composition of the different components of fossil plants on such a scale using the well-established coupled techniques of gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry. Here, we report the application of techniques for surface analysis to investigate the composition of Rhynia gwynne-vaughanii. X-ray photoelectron spectroscopy of two different spots (both 300 µm × 600 µm) confirmed the presence of carbon. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) revealed ‘chemical maps’ (imaging mode with 300 nm resolution) of aliphatic and aromatic carbon in the intact fossil that correlate with the vascular structures observed in high-resolution optical images. This study shows that imaging ToF-SIMS has value for determining the location of the molecular components of fossil embryophytes while retaining structural information that will help elucidate how terrestrialization shaped the early evolution of land plant cell wall biochemistry.

This article is part of a discussion meeting issue ‘The Rhynie cherts: our earliest terrestrial ecosystem revisited’.

Determination of Asphaltene Critical Nanoaggregate Concentration Region Using Ultrasound Velocity Measurements

Asphaltenes constitute the heaviest, most polar and aromatic fraction of petroleum crucial to the formation of highly-stable water-in-crude oil emulsions. The latter occur during crude oil production as well as spills and cause difficulties to efficient remediation practice. It is thought that in nanoaggregate form, asphaltenes create elastic layers around water droplets enhancing stability of the emulsion matrix. Ultrasonic characterisation is a high-resolution non-invasive tool in colloidal analysis shown to successfully identify asphaltene nanoaggregation in toluene. The high sensitivity of acoustic velocity to molecular rearrangements and ease in implementation renders it an attractive method to study asphaltene phase properties. Currently, aggregation is thought to correspond to an intersection of two concentration-ultrasonic velocity regressions. Our measurements indicate a variation in the proximity of nanoaggregation which is not accounted for by present models. We attribute this uncertainty to physico-chemical heterogeneity of the asphaltene fraction driven by variation in molecular size and propose a critical nanoaggregation region. We treated asphaltenes from North and South American crude oils with ruthenium ion catalysed oxidation to characterize their n-alkyl appendages attached to aromatic cores. Principal component analysis was performed to investigate the coupling between asphaltene structures and velocity measurements and their impact on aggregation.

Deterioration of the Hanson Logboat: chemical and imaging assessment with removal of polyethylene glycol conserving agent

The state of preservation of wood in two samples from the Hanson Logboat, currently on display in Derby Museum and Art Gallery, was analysed using elemental analysis (EA), pyrolysis–gas chromatography/flame ionisation detection (Py-GC/FID), pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS) and scanning electron microscopy (SEM). The samples were collected in 2003, after the boat had undergone conservation, and in 2011 after the condition of the boat began to deteriorate. Solvent extraction enabled removal of polyethylene glycol, with which the wood had been impregnated during conservation, allowing the degradation of the cellulose and lignin polymeric components of the woods to be assessed. Elemental compositions (C, H, N, O, S), Py–GC/FID, Py-GC/MS and SEM imaging reveal extensive degradation of the wood polymers during the eight year period since conservation.

Contrasting temperature responses of dissolved organic carbon and phenols leached from soils

BACKGROUND AND AIMS

Plant-derived phenols are a major input to the terrestrial carbon cycle that might be expected to contribute substantially to dissolved organic carbon (DOC) losses from soils. This study investigated changes in DOC and phenols in leachates from soil treated with individual plant litter types under seasonal temperature change.

METHODS

Senescing grass, buttercup, ash and oak litters were applied to soil lysimeters. Leachates were collected over 22 months and analysed for DOC and phenols. Phenols in litter and DOC were analysed using on-line thermally assisted hydrolysis and methylation with tetramethylammonium hydroxide (TMAH).

RESULTS

Mass loss differed between litter type (buttercup>ash>grass>oak). Phenol concentrations in the senescing litters (<2 % TOC) were small, resulting in minor losses to water. Seasonal soil temperature positively correlated with DOC loss from litter-free soils. An initial correlation between temperature change and total phenol concentration in grass and ash litter treatment leachates diminished with time. Dissolved phenol variety in all litter-amended soil leachates increased with time.

CONCLUSIONS

Plant-derived phenols from senescing litter made a minor contribution to DOC loss from soils. The strength of the relationship between seasonal temperature change and phenol type and abundance in DOC changed with time and was influenced by litter type.

Kerogen-bound and free hopanoic acids in the messel oil shale kerogen

The distribution of the free and bound hopanoic acids in both unheated and heated (350 degrees C for 50 h) kerogens, isolated from the Messel oil shale, were analyzed by GC-MS. The bound acids were released by subjecting the kerogen to three different treatments, namely, thermochemolysis in the presence of tetramethylammonium hydroxide (TMAH), as well as basic and acidic hydrolyses. All of these methods gave a series of hopanoic acids ranging from C(30) to C(34), in which the biological 17beta, 21beta(H) configuration is prominent. Both 22R and 22S epimers are present for the C(30) acid, whereas the others are dominated by the sidechain 22R-configuration. Thermochemolysis in the presence of TMAH was the most efficient in releasing kerogen-bound hopanoids. Following pyrolysis, the acids are generated and released into the free fraction with apparent epimerization occurring at C-17, C-21, and C-22. The bound hopanoic acids may be both chemically bonded as well as possibly being physically encapsulated within the macromolecular fraction of sedimentary organic matter. They are therefore either generated by breaking the bonds which bind them to the kerogen or they are released as a result of the macromolecular cage being broken apart.

Degradation of lignin in wheat straw during growth of the oyster mushroom (Pleurotus ostreatus) using off-line thermochemolysis with tetramethylammonium hydroxide and solid-state (13)C NMR

The oyster mushroom (Pleurotus ostreatus) is widely cultivated on wheat straw (Triticum aestivum); however, there is a need to better understand the relationship between the chemical composition of the compost and mushroom growth. Wheat straw was degraded over a period of 63 days by P. ostreatus during which time it was sampled at weekly intervals. Off-line thermochemolysis with tetramethylammonium hydroxide and solid-state (13)C NMR were then used in the molecular characterization of the undegraded wheat straw and the degraded samples. The degraded wheat straw samples had a lower proportion of syringyl- to guaiacyl-derived moieties and cinnamyl- to guaiacyl-derived moieties than the undegraded control. There were increases in both guaiacyl and syringyl acid to aldehyde ratios with composting time, which showed that side-chain oxidation has been mediated by P. ostreatus. The (13)C NMR spectra confirmed the increase in carboxyl content but indicated that the overall lignin and methoxyl contents remained relatively constant, although some nonsystematic variations were observed. The spectra also showed a decrease in amorphous noncellulosic polysaccharides in relation to the crystalline cellulose upon degradation.

Morbidity associated with gastrostomy placement in children demands an ongoing integrated approach to care

AIMS

To evaluate the short and long term morbidity of gastrostomy insertion, and to identify ongoing management requirements.

METHODS

A retrospective review was undertaken of the hospital casenotes of children aged up to fifteen years who had a gastrostomy placed in Christchurch over a six year period to March 1998.

RESULTS

42 children had a gastrostomy fashioned, 35 in the last three years of the period reviewed. The most common underlying diagnosis was neurological disease (48%), and the most common indication for tube placement was failure to feed orally. Complications were frequent but minor. Morbidity was related to local erythema and infection around the stoma (85 episodes in 23 children), persistent and major gastric fluid leakage (three episodes), and mechanical failure of the tube (21 episodes). Gastro-oesophageal reflux was seen in fourteen children, nine of whom had primary neurological disease. Complications were seen more after open gastrostomy than after percutaneous endoscopic placement (6.6:4.7). There was no mortality related directly to the gastrostomy tube or tube placement.

CONCLUSIONS

An increase in the frequency of gastrostomy placements has been seen over this period. As the number of children with a gastrostomy increases, so too have the demands on medical and nursing staff to care for and manage the devices. The frequency of minor ongoing problems necessitates ongoing support of the child and care of the gastrostomy. A close working relationship between outreach nursing staff, stoma therapists and medical staff is required if morbidity is to be minimised. Education, audit and review remain important additional aspects of care.

Outcome of primary vesicoureteric reflux detected following fetal renal pelvic dilatation

OBJECTIVE

Postnatal investigation of mild degrees of fetal hydronephrosis has allowed subsequent detection of infants with vesicoureteric reflux (VUR). This study was designed to provide short to medium term information on such infants who had primary VUR, the rates of renal damage and progression over time, the risk factors for such damage and to compare the characteristics of those who had mild dilatation of the fetal renal pelvis (4-9 mm) with those who had moderate-severe dilatation (> or = 10 mm).

METHODOLOGY

Since June 1989, infants whose antenatal sonography had identified a fetal renal pelvis with an anteroposterior diameter of > 4 mm were investigated postnatally with renal ultrasonography and micturating cystourethrogram (MCU), and placed on antimicrobial prophylaxis. Those with VUR received 99mTc-dimercaptosuccinic acid (DMSA) scintigraphy. Infants were followed until discharge based on resolution of VUR, surgery, or low grade VUR. A 5.5 year cohort between June 1989 and December 1994 formed the study population. A review of notes and clinical review (if still under follow up) was undertaken. Vesicoureteric reflux on MCU was regraded according to the International Classification, and reflux nephropathy on DMSA scans was regraded according to criteria proposed by Goldraich. Regression analysis was used to assess risk factors for renal damage.

RESULTS

There were 69 infants (37 girls, 32 boys) who were identified with primary VUR, with 37/69 having bilateral reflux. Eight had a urinary tract infection during the follow-up period. There was a broad distribution of grades of reflux detected (Grades I-3, Grades II-23, Grades III-19, Grades IV - 17, Grades V-7). 99m-Tc-dimercaptosuccinic acid scans on 57/69 (83%) demonstrated renal damage in eight infants (14%). This was predominantly global contraction of function. No progression of renal damage was seen over 2-7 years. Regression analysis showed a strong association between Grades IV, V reflux and the presence of renal damage (P < 0.001). Review of the degrees of fetal renal pelvic dilatation showed that 60/69 infants were detected because of mild (4-9 mm) dilatation. The majority (43/60) had lower grades of reflux (Grades I, II, 3), but there was no obvious cut-off between 4 and 9 mm that could predict high grade VUR (Grades IV, V).

CONCLUSIONS

The use of 4 mm to define an abnormal fetal renal pelvis allows a much larger group of infants with high grade primary VUR to be detected than if a higher cut-off measurement is used. Although it also detects many more infants with low grade primary VUR, there is no obvious cut-off point at which this effect predominates. Progressive renal damage was not seen in follow up of up to 7 years of age. Renal damage on DMSA scanning in this group is almost exclusively a pattern of global contraction of function. The presence of high-grade VUR appears to be the only important factor in predicting the presence of renal damage.

Anti-endomysial and anti-gliadin antibodies in screening for coeliac disease in children at greater risk of developing coeliac disease

AIMS

To determine the prevalence of coeliac disease in selected groups of children presenting to a paediatric department.

METHODS

Children presenting to the Paediatric Department at Christchurch Hospital were enrolled upon identification of one or more factors associated with increased risk of coeliac disease. All subjects were screened with anti-endomysial antibody and antigliadin antibody tests. Those children with positive tests underwent small bowel biopsy.

RESULTS

36 of 153 children had abnormal antibody tests. Seven (4.5%) of 34 children who underwent small bowel biopsies were found to have histological findings consistent with coeliac disease. Five of these children had presented with symptoms not classically ascribed to coeliac disease (failure to gain weight or non-specific abdominal pain).

CONCLUSIONS

The possibility of coeliac disease should be considered in children with atypical symptoms and the diagnosis excluded by appropriate testing. Recognition of the variable presentations associated with coeliac disease in children is clinically relevant.

Femoral growth lines: bony birthmarks in infants

OBJECTIVE

During a study of infants who were being examined for antenatal renal dilatation, we noted that many had growth lines in their proximal femur on postnatal radiographs. We decided to determine the prevalence of growth lines in healthy infants.

MATERIALS AND METHODS

Voiding cystourethrograms of 791 neonates and infants, 0-6 months old, were reviewed. All who had documented severe illness or no reasonable view of the proximal femur were excluded, resulting in a cohort of 633 healthy infants. Each study was coded for presence or absence of a growth line in the proximal femur, and the distance of the growth line from the metaphyseal edge was measured to the nearest 0.5 mm. Radiographs were obtained on a unit with fixed tube-film distance. Data on the mode of delivery were collected for 136 infants.

RESULTS

Of 633 eligible infants, 247 (39%) of 633 had a discernible growth line. The distance of the growth line from the metaphysis, in millimeters, correlated significantly with age in days (r = .81, p < .01). Infants delivered vaginally were more likely to have a growth line than were those born by cesarean delivery (p = .049).

CONCLUSION

A growth line in the proximal femur is common in healthy infants. The rate of longitudinal growth of the proximal femoral metaphysis, on radiographs, is approximately 1 mm per 11 days (1 mm per 13 days when corrected for magnification). Approximation of the timing of prenatal and postnatal stressful events that result in a growth disturbance line may be possible.

D-lactic acidosis in short bowel syndrome

Short bowel syndrome can present many complex management issues and may be complicated by various metabolic problems. D-lactic acidosis in the setting of short bowel syndrome has been described only rarely in children. A further case is presented with a review of typical clinical manifestations of D-lactic acidosis and reported management options. Early recognition and appropriate management is essential to avoid morbidity secondary to this complication of short bowel syndrome. Probiotic therapies may have an increasing role in prevention and management of this complication.

Simultaneous presentation of coeliac disease and ulcerative colitis in a child

Coeliac disease and inflammatory bowel disease (IBD) individually are not uncommon in children, but the occurrence of both conditions together is rare. The combined presentation of coeliac disease and IBD in a girl of 7 years is presented with a review of the related literature. The occurrence of coeliac disease with IBD should be considered at the time of diagnosis and at relapse, or where there is difficulty maintaining remission in established IBD. Screening with serum antibody tests may be helpful.

Vesicoureteric reflux in the newborn: relationship to fetal renal pelvic diameter

There has been a low yield of primary vesicoureteric reflux (VUR) from screening the fetal urinary tract during obstetric sonography. We sought to determine whether changing the cut-off level of fetal renal pelvic diameter from 10 mm to 4 mm would improve the yield of VUR. In a prospective community-based study, a fetal renal pelvic diameter of 4 mm or more on a transverse view of the fetal renal hilum at obstetric sonography after 16 weeks' gestation was found in 426 fetuses from 9,800 consecutive pregnancies. After birth, renal sonography was performed on 386 of the 426 babies. Of the 386 babies, 264 (187 boys) had a voiding cystourethrogram (VCUG) at a mean age of 9 weeks. Primary VUR was detected in 33 (16 boys) of the 264 infants (13%), and secondary VUR in another 5 (2%). Only 5 of the 33 (15%) babies with primary VUR would have been detected if a cut-off point of 10 mm for fetal renal pelvic diameter had been used. The prevalence of reflux was similar at each cut-off level of antenatal renal pelvic diameter from 4 to 10 mm. Neither calyceal nor ureteric dilatation was helpful in differentiating those with from those without VUR. The postnatal renal sonogram did not distinguish whether reflux was present or not. More infants with primary VUR, particularly girls, were found by changing the cut-off point for fetal renal pelvic diameter from 10 mm to 4 mm, and performing a VCUG on all such infants even if the postnatal renal sonogram was normal. Of the 33 infants with primary VUR, 9 (27%, 5 boys) had an abnormal dimercaptosuccinic acid scan. Our findings support the screening of the obstetric population for a fetal renal pelvic diameter of 4 mm or more, and then investigating the infants for VUR after birth.

Unravelling the genetics of vesicoureteric reflux: a common familial disorder

Primary vesicoureteric reflux (VUR) is one of the more common genetic disorders. Little is yet known about the genetics of this potentially manageable childhood condition, which is characterised by regurgitation of urine from the bladder to the kidney. The VUR phenotype is associated with shortness of the submucosal segment of the ureter due to congenital lateral ectopia of the ureteric orifice. VUR is found in 30-50% of infants and young children with a urinary tract infection. A serious concern in families with an affected patient is that approximately one half of siblings or offspring will be affected, but up to a half of these affected siblings and offspring may be asymptomatic in childhood. If left untreated, these patients may present later in life with proteinuria, hypertension or renal failure. VUR is the commonest cause of end-stage renal failure in children, and an important cause in adults. As the kidney damage resulting from severe VUR is preventable, early detection is desirable. The techniques for clinical diagnosis are invasive and costly, reinforcing the importance of identification of a gene for VUR to facilitate genetic screening. Although family studies suggest a major dominant gene, the inheritance pattern is still a matter of debate. In rare instances, VUR occurs in association with other diseases, such as the coloboma-ureteric-renal syndrome, which is caused by a PAX2 gene mutation. In this review, we present evidence that this common disorder may be caused by mutations in the developmental pathway of which the PAX2 gene forms a part.

Aerodigestive tract foreign bodies in children: one year's experience at Christchurch Hospital emergency department

AIM

To review the children who presented to Christchurch Hospital emergency department with aerodigestive tract foreign bodies during 1994.

METHOD

The emergency department, and impatient notes were retrospectively reviewed for all children presenting with a complaint of an aspirated or ingested foreign body, for the period 1 January 1994 to 31 December 1994. One hundred and thirty-nine children were identified as being eligible for study. A telephone followup interview to determine outcome was also conducted.

RESULTS

The 139 children had a median age of 3 years, 2 months and an even gender-distribution. The foreign bodies implicated were 47 coins, 23 sharp objects, 4 button batteries and a wide variety of blunt, noncorrosive foreign bodies. Twelve of the foreign bodies required removal (5 oesophagoscopies, 4 bronchoscopies, 2 indirect laryngoscopies and 1 laparotomy). Forty-five of 139 children had no significant symptoms at any time and these children had a total of 43 x-rays and 5 followup visits, none of which changed management. No child assessed by followup interviews had suffered complications requiring further evaluation or treatment.

CONCLUSION

Children who have ingested blunt, noncorrosive foreign bodies, and who have had no significant symptoms at anytime require no investigations after exclusion of oesophageal impaction but should be reviewed if symptoms develop.

IGF-1 and IGFBP-3 screening for disorders of growth hormone secretion

AIM

To assess the value of plasma assays of insulin like growth factor (IGF-1) and insulin like growth factor binding protein 3 (IGFBP-3) in the diagnosis of growth hormone disorders in children and adults.

METHODS

Plasma IGF-1 and IGFBP-3 were measured in 47 children referred for the assessment of short stature, 26 adult subjects with hypopituitarism and in 10 adult subjects with acromegaly. Findings were compared with results obtained in 148 normal children and 124 normal adult subjects who comprised the reference range.

RESULTS

Levels of both growth factors and especially IGF-1 are highly age dependent in normal children and adults. Six of 47 short children had growth hormone deficiency and in these cases both IGF-1 and IGFBP-3 were close to the lower limit or below the normal reference range. In young children ( < 10 yr) IGFBP-3 was more informative than IGF-1, distinguishing normal short children from those with growth hormone deficiency. IGF-1 levels were raised in all 10 acromegalic adults, eight of whom had normal levels of IGFBP-3. Similarly growth hormone deficient adults were better identified (23 of 26 patients) by IGF-1 whereas IGFBP-3 was subnormal in only eight cases.

CONCLUSIONS

Provided results are reviewed in relation to an age related normal reference range, both IGF-1 and IGFBP-3 are simple and convenient screening tests for assessing growth hormone deficiency in children. In adults plasma IGF-1 is the diagnostic test for a disorder of growth hormone excess. Low IGF-1 in an adult with a history of pituitary disease strongly suggests the presence of growth hormone deficiency.

Growth patterns and outcomes in congenital adrenal hyperplasia; effect of chronic treatment regimens

AIM

To assess outcome (final height and sexual maturation), growth patterns and blood pressure in 16 children with congenital adrenal hyperplasia treated at one institution over a 30 year period.

METHODS

Growth patterns and maturation were determined by retrospective review (median follow up period 14 years). Dose adjustment of corticosteroid replacement treatment, sufficient to maintain normal levels of adrenal precursor secretion, was determined using assays of urinary pregnanetriol excretion (up to 1975) or early morning measurements of plasma 17 hydroxy progesterone and plasma renin activity at intervals of 4-6 months.

RESULTS

In 7 of 15 patients the growth pattern during infancy was retarded--13 not exceeding the population mean. Catchup growth as steroid dose fell with age was not usually observed. In boys, height potential was further compromised by a significant reduction in growth velocity during puberty. None of nine patients evaluated at final height had attained the target height. During the first year of life, plasma renin activity was suppressed below the reference range in six of nine infants. Despite this, and lower than normal levels of plasma renin activity in childhood, most children were normotensive.

CONCLUSIONS

Avoiding salt depletion in infancy and excessive androgen secretion during childhood do not ensure normal growth patterns or normal final height. Impaired final height in congenital adrenal hyperplasia is more likely to be due to over treatment, particularly in infancy when lower doses of corticosteroids may improve height prognosis.

Pregnancy in renal transplant recipients: the Christchurch experience

AIM

Assess the pregnancies of our female renal transplant recipients and to document long term maternal and fetal outcome.

METHODS

Between 7 June 1972 and 31 December 1992 112 females had at least one renal transplant. Sixty-four of these 112 women were in the reproductive age and had a functioning graft.

RESULTS

Nine women had 16 pregnancies which resulted in 11 live births and three first trimester abortions. Two unplanned pregnancies were terminated. Mean age at transplantation was 17.2 yr [range 16-22.5 yr] and mean interval from transplant to pregnancy was 6.8 yr [range 1.8-9.0 yr]. Prednisone and azathioprine were used in all patients and cyclosporin in five. For seven of the successful pregnancies plasma creatinine remained < or = 0.10 mmol/L. One of these women developed allograft nephropathy 5 years after delivery and returned to dialysis 9 years later. For the other four successful pregnancies the preconception plasma creatinine was 0.12-0.14 mmol/L. The woman with two successful pregnancies had a halving of glomerular filtration rate during the second pregnancy, but it has remained stable for 15 years; one was poorly compliant with her immunosuppressive regimen and reached endstage renal failure two years after delivery; one developed cyclosporin nephrotoxicity, but 18 months later renal function was stable after a dosage reduction. Ten infants were delivered by caesarean section, four of them urgently. Three babies were preterm and five growth retarded. One died of sudden infant death syndrome at four months. All other infants developed normally.

CONCLUSION

There is no contraindication to pregnancy in female transplant recipients who have stable graft function and controlled blood pressure. Management of such pregnancies should be by shared obstetrical/nephrological/paediatric care.

Diagnosis of obstructive hydronephrosis in infants: comparison sonograms performed 6 days and 6 weeks after birth

OBJECTIVE

The purpose of this study was to compare the usefulness of renal sonograms obtained 6 days and 6 weeks after birth in differentiating obstruction from nonobstruction in patients with antenatal pyelocaliceal dilatation shown by sonography and to establish sonographic criteria to determine the degree of postnatal pyelocaliceal dilatation that warrants further investigation.

MATERIALS AND METHODS

Criteria for an infant to enter the study were fetal pyelectasis of 4 mm or greater, two postnatal sonograms with the second showing persisting pyelectasis extending at least into the infundibula, and a voiding cystourethrogram showing normal findings. One hundred thirty kidneys in 100 infants met the study criteria. The first postnatal sonogram was obtained at a mean age of 6 days (range, 1-14 days) and the second at a mean age of 6.6 weeks (range, 3-16 weeks). The degree of pyelectasis was measured in the anteroposterior direction on the transverse postnatal sonograms. The diagnosis of obstruction was made by excretory urography in 99 infants and nephrostography in one infant. Kidneys were categorized as definitely obstructed, possibly obstructed (anatomic features of obstruction on excretory urogram but functionally not obstructed), or not obstructed. Receiver-operating-characteristic (ROC) curves based on renal pelvic diameters were plotted for both sonograms; the ability to detect definite obstruction or possible obstruction was compared for the two time periods; and optimal cutoff points were determined.

RESULTS

The mean diameter of the renal pelvis was not significantly different between the sonogram obtained at 6 days and the sonogram obtained at 6 weeks for the 86 nonobstructed kidneys. For the 27 kidneys that were obstructed, the mean pelvic diameter increased from 18 mm (range, 5-54 mm) on the sonogram obtained at 6 days to 22 mm (range, 11-60 mm) on the sonogram obtained at 6 weeks. The mean pelvic diameter of 17 kidneys categorized as possibly obstructed increased from 6 mm (range, 0-11 mm) to 10 mm (range, 6-20 mm) between the first and second sonograms. The ROC curves for all sonograms obtained at 6 weeks provided cutoff points with greater sensitivity and specificity than did the curves for the sonograms obtained at 6 days. The optimal cutoff points were 6 mm for possible obstruction (sensitivity, 100%; specificity, 57%) and 11 mm for definite obstruction (sensitivity, 100%; specificity, 57%) and 11 mm for definite obstruction (sensitivity, 100%; specificity, 96%).

CONCLUSION

Renal obstruction may be underestimated or missed on a renal sonogram obtained 6 days after birth. A sonogram obtained 6 weeks after birth is more specific for detecting obstruction.

Pyloric stenosis: the Christchurch experience

OBJECT

Evaluation of the performance of a general paediatric unit in diagnosis and treatment of infantile hypertrophic pyloric stenosis, including morbidity and measurable outcomes in relationship to changing management.

METHODS

Retrospective case note audit.

RESULTS

In the 11 year period 1980-91, 103 infants underwent surgical correction of pyloric stenosis, after correction of metabolic disturbance. There was a predominance of males (82.5%), but the incidence of first born infants affected was no greater than the population birth order. While the clinical diagnosis was firm in the majority of infants, over 75% had at least one radiologic imaging procedure. On objective criteria, 80% of patients were less than 5% dehydrated, despite having electrolyte and acid-base derangement. The relatively high incidence of mucosal perforation (31.1%) did not lead to further morbidity. The incidence of postoperative vomiting (19.4%) was significantly less than in previously reported series. There were no deaths, one patient suffered longterm neurologic deficit following profound hypoglycaemia. A change in preoperative management to aggressive rehydration did not reduce morbidity, and was associated with an increased median postoperative stay.

CONCLUSIONS

Pyloric stenosis remains a relatively common surgical problem of infancy. The cornerstone of diagnosis remains a clinical one; however there is a place for radiology. Operative repair is elective, following correction of metabolic derangement. In a general paediatric unit, long term sequelae of initial morbidity are rare.

Ceftriaxone for paediatric bacterial meningitis: a report of 62 children and a review of the literature

AIM

The purpose of this prospective study was to document the efficacy of ceftriaxone in the treatment of childhood bacterial meningitis in a general paediatric unit.

METHODS

All children presenting with bacterial meningitis to Christchurch Hospital between January 1987 and June 1991 were enrolled in this prospective study and received ceftriaxone 100 mg/kg/d for seven days. Outcome was defined by parameters including mean time to fever defervescence, prolonged fever, days in hospital, seizures, and other acute neurological sequelae, requirement for ventilation, mortality and morbidity. Audiology was performed at six weeks and again at three months if abnormal. Neurodevelopmental assessment was performed at three months. Side effects were recorded.

RESULTS

There were 62 evaluable children. The mortality rate was 4.8% (3 children). Two children (3.4%) had clinically detectable neurological sequelae at the three month assessment. The mean duration of stay was 8.7 nights. Five children (8%) required ventilation. Mild self limiting diarrhoea occurred in 29%.

CONCLUSIONS

Ceftriaxone is an effective, safe and well tolerated antimicrobial for the treatment of childhood meningitis. It compares favourably with other equipotent antimicrobials. With a relatively long half life once daily administration is possible with a cost advantage.

Neuroendocrine protein 7B2 in Prader-Willi syndrome

7B2 is a neuroendocrine polypeptide of unknown function, the gene for which is sited near or within the chromosomal region deleted in Prader-Willi syndrome and Angelman's syndrome. Plasma immunoreactive 7B2 levels were measured in 26 individuals with Prader-Willi syndrome, and appropriate controls. Plasma 7B2 levels were within normal limits compared to the control groups, in adults with Prader-Willi syndrome. 7B2 levels in children with Prader-Willi syndrome were higher, this age-dependent variation having been previously reported in normal children.

Ondansetron antiemetic therapy for chemotherapy and radiotherapy induced vomiting in children

AIM

To evaluate ondansetron as the sole antiemetic in children treated with emetogenic chemotherapy and irradiation.

METHODS

Fifteen children aged 3-11 years were studied. Seven had acute lymphoblastic leukaemia, two acute myeloid leukaemia, two lymphoma and four had other tumours. Ondansetron 5 mg/m2 IV or 4 mg by mouth was given immediately before chemotherapy or radiation treatment and continued eight hourly for 24 hours. Nausea and vomiting was assessed during treatment and for the next 48 hours, and graded using WHO criteria.

RESULTS

Thirty-eight courses of chemotherapy were assessed, 27 severely emetogenic and 11 moderately emetogenic. Two included total body irradiation. The most severe nausea and vomiting was grade 2 (transient vomiting) reported in six children. Nausea and vomiting was abolished on subsequent courses in four of these children by increasing the ondansetron dose frequency to six hourly. The remaining children experienced no nausea or vomiting (n = 7) or only nausea (n = 2). Nausea and vomiting were each completely controlled in 27 courses.

CONCLUSIONS

Ondansetron is a cost effective and safe antiemetic in children receiving chemotherapy and total body irradiation, minimises weight loss on treatment and enables outpatient chemotherapy in some cases.

Aplastic anaemia in Christchurch Hospital 1979-89

We have reviewed the records of all patients referred to our departments with aplastic anaemia during the 11 years from 1979 to 1989. Of the 22 patients identified, 19 fulfilled the standard criteria for severe aplastic anaemia. There were 11 females and 11 males. Their mean age was 35 (range 2-85 years). Five cases followed exposure to drugs known to cause aplastic anaemia and one had a recent history of viral hepatitis. A variety of treatments were used. Four patients received an allogeneic bone marrow transplant (BMT) from matched sibling donors and two of these were alive and well 65 and 120 months post BMT. Antithymocyte globulin (ATG) treatment has been followed by lasting complete remission in two of the six patients treated and a partial response was seen in one other patient. Cyclosporin therapy was associated with unmaintained complete remission in one of the three patients given this drug after ATG had failed. The remaining 13 patients received only supportive care with or without androgens and six (46%) had early recovery of bone marrow function with lasting complete remission. These patients illustrate some of the therapeutic options available for aplastic anaemia.

A paediatric day ward: parental expectations, perceptions, and satisfaction

OBJECT

to evaluate an acute paediatric day ward service from the parental perspective.

METHODS

parental interview using structured questionnaire.

RESULTS

overall satisfaction with the day ward concept and practice was high. Specific delays in the admission and management process were highlighted, as were concerns over practical issues such as parking facilities, pharmacy support, and perceived staff workload.

CONCLUSIONS

the broad aims of the unit are being met. Areas for potential improvement are defined and discussed.

A paediatric day unit: the first year's experience

In June 1989 a day unit was introduced into the paediatric department of Christchurch Hospital. Over the subsequent year, 1308 admissions occurred to the unit. Five hundred and thirty (40.6%) of the children were discharged home on the day of referral, only 22 (4%), were readmitted to the inpatient facility within a week of their first assessment. The common conditions dealt with were asthma and acute respiratory tract infection and the pattern generally reflected that normally seen in the inpatient wards. The average stay in the day unit was four hours thirty minutes. The day unit has proved to be effective in reducing overnight inpatient admissions but it requires a higher staff ratio than allocated to ensure rapid and efficient turnover. Utilisation on the weekends and wider use by other specialities dealing with children would increase the units effectiveness further.

Bacterial meningitis in childhood: a 13 year review

One hundred and forty-five episodes of acute bacterial meningitis in children seen over a 13 year period are reviewed. The mortality rate was 1.4%. Over the study period H influenzae type b remained as the dominant causative organism, with 11% of the isolates being beta-lactamase positive. The difficulties in diagnosis in children, the sequelae of sensorineural deafness and continued morbidity in this disorder are stressed.

A mesoblastic nephroma with hypercalcaemia

A 14 week old female infant who presented with a mesoblastic nephroma was found to be hypercalcaemic. This was corrected prior to removal of the tumour and serum calcium concentrations remained within the normal range postoperatively. Hypercalcaemia is a life threatening complication of mesoblastic nephromas and should be investigated in all cases.

Single dose gentamicin treatment of urinary infections in children

Sixty-nine children with urinary tract infections were randomly allocated to single dose gentamicin therapy (n = 39) or a seven day course of an appropriate antibiotic (n = 30). During the following six weeks the response to treatments did not differ and this was not altered by the child's clinical diagnosis, past history of infection or presence of radiological abnormalities. The poorest response was in those children with a history of recurrent infections (p less than 0.01) and/or radiological abnormality (p less than 0.02). Single dose therapy had significantly less suppression upon rectal (p less than 0.001) and periurethral (p less than 0.02) flora. There was a tendency for those not cured by single dose treatment to relapse whereas those treated by conventional therapy tended to be reinfected.

A protocol for the investigation of infants and children with urinary tract infection

An investigation protocol, designed to reduce invasive procedures to a minimum, is described for the detection of reflux nephropathy in infants and children. Intravenous urography and voiding cysto-urethrography is necessary in patients up to the age of 2 years presenting with urinary tract infection, but in children over 2 years of age the protocol limits the investigation to an intravenous urogram unless this is abnormal. A review of this policy after 5 years has indicated that it is appropriate provided that children who continue to have infections have further evaluation including a voiding cysto-urethrogram.

An evaluation of a structured case record in a paediatric department

Two hundred and thirty-four paediatric medical records from August 1985 and 257 from August 1986, were evaluated and compared by criteria audit in order to assess the effects of the introduction of a structured admission form. The presence or absence of predetermined items of clinical relevance were recorded. A statistically significant improvement in the recording of 12 of 23 key items occurred following the introduction of a structured format. However, two of these items were recorded less frequently in the new notes. Changing working hours for house officers and an increase in overseas graduates had no significant influence on the results. Structured case records can improve information gathering, but careful design and reevaluation are important.

Co-trimoxazole red cell aplasia in leukaemia

A 4 year old boy with acute lymphoblastic leukaemia developed a pure red cell aplasia 13 months after entering remission and while on maintenance chemotherapy. Co-trimoxazole was also being administered for prophylaxis against Pneumocystis carinii infection. When co-trimoxazole was stopped the red cell aplasia resolved.

Should a lateral chest radiograph be routine in suspected pneumonia?

A study was undertaken on the chest X-rays of 414 children suspected clinically of having pneumonia, to ascertain whether the lateral film provided additional diagnostic information. In only nine cases the lateral film confirmed the diagnostic value of the frontal film and it is suggested that a routine lateral chest film should not be taken for children suspected of having pneumonia.

Allogeneic bone marrow transplantation at Christchurch 1979-1985

Twelve bone marrow transplants have been carried out at Christchurch since 1979 in five patients with aplastic anaemia and seven with acute leukaemia. Five patients are currently alive at 77, 69, 63, 45, and seven months post-transplant. Acute and chronic graft versus host disease have been major problems and its clinical features and management are described. Long term follow-up data is presented on the four patients currently alive at between three to six years post-transplant. The practical problems we have experienced by carrying out bone marrow transplants without special funding have been considerable and the implications of this are discussed.

Acute epiglottitis in childhood, Christchurch 1970-84

The case records of 31 children presenting to Christchurch Hospital with acute epiglottitis over the last 15 years have been reviewed. There has been a significant increase in incidence over this period (p less than 0.05). Despite generally classical presenting features the disease was recognised in only 26% of children when seen by general practitioners prior to admission. The increasing problem of ampicillin resistance to Haemophilus influenzae type b locally has resulted in a change in first line antibiotic therapy in recent years. Changes have also occurred in methods of airway management with elective nasotracheal intubation now the usual procedure.

Acute respiratory tract infections of children in hospital: a viral and Mycoplasma pneumoniae profile

Respiratory specimens and blood were collected from all infants and children admitted with acute respiratory illness to a paediatric unit in Christchurch from May to November (late autumn, winter and spring) 1983, to define the viral aetiological agents involved. A virus or Mycoplasma pneumoniae was identified in 160 (50%) of 317 children studied by the rapid indirect immunofluorescence, virus culture and/or serological techniques. Aetiological agents were detected in 71% of children with bronchiolitis, 57% with pneumonia, 53% with bronchitis, 40% with laryngotracheitis (croup), and 45% with upper respiratory tract illness. Respiratory syncytial virus was the most frequently identified virus, confirming the importance of this virus as a cause of respiratory illness requiring hospitalisation of young children in Christchurch. An epidemic due to influenza A/Dunedin/7/83 (HINI) and A/New Caledonia/4/83 (HINI) viruses occurred during the study period.

Vesicoureteric reflux: segregation analysis

Complex segregation analysis was applied to data from 88 families containing at least one person with vesicoureteric reflux. Analysis showed that a single major locus was the most important causal factor in this condition, with the mutant allele being dominant to the normal allele and having a gene frequency of about 0.16%. Forty-five percent of gene carriers will have vesicoureteric reflux and/or reflux nephropathy as adults and 15% will develop renal failure, compared to 0.05% and 0.001%, respectively, for those not carrying the gene. This analysis confirms the importance of screening close relatives of persons with proven vesicoureteric reflux or reflux nephropathy.

Radiological abnormalities in infants with urinary tract infections

An intravenous urogram and micturating cystourethrogram were carried out in 100 infants presenting with documented urinary tract infections. Ninety three cases were identified by suprapubic aspiration and 7 by culture of two voided urine samples containing greater than 100 X 10(6) organisms per litre. The urinary tract abnormalities were analysed in respect of their clinical importance, patient's age, sex, and prematurity (in the 10 preterm infants). Radiological abnormalities were found in 47% of the infants (40% of boys; 63% of girls). Twenty nine per cent of the infants had a urinary tract abnormality regarded as clinically important--namely grade 3 or 4 vesicoureteric reflux, reflux nephropathy, or obstructive lesions requiring surgery. Six of the 10 preterm infants had radiological abnormalities. Spontaneous resolution or improvement occurred within 6 months of birth in three of the four preterm infants with severe vesicoureteric reflux.

Antimicrobial prescribing errors in children

During a 120 day period, the charts of patients who had received antimicrobial agents were examined. This group numbered 255 and comprised 52% of children admitted with infections. Patients treated by family doctors and/or hospital staff predominantly had respiratory infections and the ampicillin/amoxycillin group of drugs was most commonly prescribed. Of the 203 antimicrobial agents prescribed by hospital staff, 64% were considered to be prescribed appropriately. The major errors related to dosage, the most potentially serious relating to the prescribing of aminoglycosides and chloramphenicol. Of the 203 antimicrobial agents prescribed for 171 children in the community, 11% were considered to be appropriately prescribed or without error. The major error was the prescribing of these drugs for syndromes of known viral aetiology. Errors were also frequent in relation to dosage, duration and choice of antimicrobial agents.

Whooping cough: Christchurch 1982

Whooping cough continues to be a major health problem in New Zealand. In a twelve month period, 64 cases were admitted to the paediatric wards of Christchurch Hospital. Of these 64 patients, 24 (37.5%) were fully immunised. The possible explanations for the large number of children contracting whooping cough, who have been immunised according to the schedule used in New Zealand, is discussed.