Design and commissioning of resistive foil bolometer diagnostics on the ST40 tokamak.

Following successful campaigns on the compact high field spherical tokamak ST40, resistive gold foil bolometers have now been installed to measure the radiated power profile. Positioned on the midplane, two bolometer cameras offer perspectives of the horizontal and vertical planes, while the third camera, situated above the midplane, provides a vertical view of the top divertor plates, including the X-point and the strike points. These cameras use a commercial off-the-shelf data acquisition platform with modules specifically designed for bolometers in a Wheatstone bridge configuration, providing both phase sensitive detection and in situ calibration. This paper presents an overview of the design and functionality of all three cameras and the commissioning of the horizontal plane camera. The commissioning of the horizontal camera shows data from a range of plasma pulses, presenting a positive correlation between the relative profiles measured from the bolometer camera and an absolute extreme ultraviolet diode camera viewing along similar lines of sight.

Detection of Xanthomonas fragariae and presumptive detection of Xanthomonas arboricola pv. fragariae, from strawberry leaves, by real-time PCR.

Real-time (TaqMan) PCR assays were developed to detect the strawberry angular leaf spot pathogen Xanthomonas fragariae (Xf) and the strawberry bacterial blight pathogen Xanthomonas arboricola pv. fragariae (Xaf). The Xf PCR (Xf gyrB) was designed within regions of the gyraseB gene, unique to Xf, after generating gyraseB DNA sequence data from Xf and other closely related strains. The Xaf PCR (Xaf pep) was designed within regions of the pep prolyl endopeptidase gene that were unique to Xaf, after generating pep DNA sequence data from Xf and Xaf strains. The Xf gyrB PCR detected only Xf strains amongst a panel of 20 Xanthomonas-related spp. and pathovars. The Xaf pep PCR assay detected all Xaf strains tested plus two other (of three tested) X. arboricola pathovars. An existing genomic DNA extraction protocol was modified to facilitate detection of both pathogens to 10(3) cells per strawberry leaf disc.

The effects of tropospheric ozone on the species dynamics of calcareous grassland.

Although ozone has been shown to reduce the growth of individual species and to alter the composition of simple species mixtures, there is little understanding of its long-term effects on species dynamics and composition in real communities. Intact turfs of calcareous grassland were exposed to four different ozone regimes in open-top chambers over three consecutive summers. Treatments provided a mean seasonal AOT40 ranging from approximately zero to 15 ppm h. Cumulative ozone exposure was a significant factor in compositional change, but only explained 4.6% of the variation. The dominant grass species (Festuca rubra) showed a consistent decline in cover in the high ozone treatment over time and the forb Campanula rotundifolia was lost from all three ozone treatments. The frequency of some species (Galium verum and Plantago lanceolata) increased with ozone exposure. Long-term effects of ozone on species composition in chalk grassland may be a function of both the sensitivity of individual species and the response of the dominant species.

DT5aP-Hib-IPV and MCC vaccines: preterm infants' response to accelerated immunisation.

AIMS: To describe the immune response of preterm infants to combined diphtheria/tetanus/5 component acellular pertussis-Haemophilus influenzae type b inactivated polio vaccine (DT5aP-Hib-IPV) and meningococcal serogroup C conjugate vaccine (MCC) under accelerated schedule. To compare results with term infants immunised with DT5aP-Hib-IPV and with historical data from preterm infants immunised with a DT3 component aP-Hib vaccine. METHODS: Prospective observational study in preterm infants born at <32 weeks gestation with comparison to contemporary cohort of term infants. DT5aP-Hib-IPV and MCC vaccines were given at 2, 3, and 4 months. RESULTS: Fifty preterm infants (mean gestational age 28.5 weeks) completed the study. After three doses of vaccines Hib polysaccharide IgG geometric mean concentration (GMC) was 1.21 microg/ml with 80% > or =0.15 microg/ml; MCC serum bactericidal assay geometric mean titre (GMT) was 1245 with 100% > or =8. All infants achieved protective titres to diphtheria, tetanus, and the three poliovirus types with > or =80% achieving protective rises in IgG against the five pertussis antigens. CONCLUSION: Preterm infants immunised with DT5aP-Hib-IPV and MCC vaccines show IgG responses to Hib and MCC greater than seen historically in both term and preterm infants with a DT3aP-Hib vaccine, and for pertussis antigens and poliovirus type 1 responses similar to that seen in term infants immunised with DT5aP-Hib-IPV. Responses to poliovirus types 2 and 3 are reduced, but all infants achieved protective titres.

Transcriptional regulation of components of the type III secretion system and effectors in Pseudomonas syringae pv. phaseolicola.

Quantitative real-time polymerase chain reaction was used with specific TaqMan probes to examine transcription of selected hrp and effector genes in Pseudomonas syringae pv. phaseolicola strains 1448A (race 6) and 1449B (race 7). Transcripts examined were from genes encoding the regulators hrpR and hrpL, core structural components of the type III secretion system (TTSS) hrcC, hrcJ, hrcN, hrcU, and hrpA; the first open-reading frame of each hrp operon, including hrpF, hrpJ, hrpP, and hrpY, and also secreted effectors hrpZ, avrPphE, avrPphF, and virPphA. All genes were induced by incubation in a minimal medium and showed patterns of expression indicating regulation by HrpRS and HrpL. Basal mRNA levels and the timing of accumulation of transcripts after induction differed significantly, suggesting the operation of additional regulatory elements. However, no clear transcriptional hierarchy emerged to explain the ordered construction of the TTSS. Quantitative analysis confirmed that the rates and levels of transcript accumulation within the first 2 h after inoculation were considerably higher in planta than in vitro, and indicated that plant cell wall contact may enhance transcription of TTSS and effector genes in P. syringae pv. phaseolicola. The low-abundance hrcU mRNA had a half-life of 16.5 min, whereas other transcripts had half-lives between 3 and 8 min.

Identification and mapping of AFLP markers linked to peanut (Arachis hypogaea L.) resistance to the aphid vector of groundnut rosette disease.

Groundnut rosette disease is the most destructive viral disease of peanut in Africa and can cause serious yield losses under favourable conditions. The development of disease-resistant cultivars is the most effective control strategy. Resistance to the aphid vector, Aphis craccivora, was identified in the breeding line ICG 12991 and is controlled by a single recessive gene. Bulked segregant analysis (BSA) and amplified fragment length polymorphism (AFLP) analysis were employed to identify DNA markers linked to aphid resistance and for the development of a partial genetic linkage map. A F(2:3) population was developed from a cross using the aphid-resistant parent ICG 12991. Genotyping was carried out in the F2 generation and phenotyping in the F3 generation. Results were used to assign individual F2 lines as homozygous-resistant, homozygous-susceptible or segregating. A total of 308 AFLP (20 EcoRI+3/MseI+3, 144 MluI+3/MseI+3 and 144 PstI+3/MseI+3) primer combinations were used to identify markers associated with aphid resistance in the F(2:3) population. Twenty putative markers were identified, of which 12 mapped to five linkage groups covering a map distance of 139.4 cM. A single recessive gene was mapped on linkage group 1, 3.9 cM from a marker originating from the susceptible parent, that explained 76.1% of the phenotypic variation for aphid resistance. This study represents the first report on the identification of molecular markers closely linked to aphid resistance to groundnut rosette disease and the construction of the first partial genetic linkage map for cultivated peanut.

Responses to a fourth dose of Haemophilus influenzae type B conjugate vaccine in early life.

OBJECTIVE: To describe the immune response of preterm infants, with a reduced response to primary Haemophilus influenzae type B (Hib) immunisation, to a fourth dose of Hib conjugate vaccine given in early life. DESIGN: Prospective observational study. SETTING: Five Wessex Neonatal Units. PATIENTS: Infants born at < 32 weeks and immunised with three doses of combined acellular pertussis-Hib vaccine, with a Hib IgG geometric mean concentration (GMC) < 1.0 microg/ml after these primary immunisations. INTERVENTIONS: An additional fourth dose of Hib conjugate vaccine given before 1 year of age. Blood taken to assess Hib IgG concentration and avidity after immunisation. MAIN OUTCOME MEASURES: Hib IgG GMC and avidity index. RESULTS: Ninety six infants (mean gestational age at birth 29.1 weeks) received a fourth dose of Hib at a mean age of 7.8 months. Hib IgG GMC after the primary immunisations was 0.17 microg/ml (95% confidence interval (CI) 0.14 to 0.20) rising to 4.68 microg/ml (95% CI 3.36 to 6.57) after the fourth dose (p < 0.0001). The IgG response to the fourth dose correlated positively with the response after the primary immunisations (p < 0.001). Hib IgG geometric mean avidity index (GMAI) after the primary immunisations was 30.87 (95% CI 20.40 to 46.73). This increased to 124.73 (95% CI 109.93 to 141.51) after the fourth dose (p < 0.0001). CONCLUSION: Preterm infants with very low IgG responses to Hib after primary immunisations with a combined acellular pertussis-Hib vaccine mount a good response to a fourth dose of Hib. This study suggests that all infants will benefit from a fourth dose of Hib, regardless of the age at which it is given.

Nosocomial respiratory syncytial virus infection in neonatal units in the United Kingdom.

Nosocomial Respiratory Syncytial Virus infections are frequently reported and tend to be more severe, because of comorbidity, such reports, however, are frequently from a single centre. The incidence and outcomes of nosocomial Respiratory Syncytial Virus infection in UK neonatal units over a five year period were estimated by interrogating the Capse Health Care Knowledge Systems database, which contains anonymised details of 55% of UK hospital admissions. A total of 79,642 admissions commenced on the infants' date of birth and contained an ICD-10 code for low birth weight or immaturity. Thirty-seven of the 79,642 admissions also contained a Respiratory Syncytial Virus code. Two (5.4%) with Respiratory Syncytial Virus and 2,736 (3.4%) without Respiratory Syncytial Virus died. Survivors with Respiratory Syncytial Virus codes experienced significantly increased length of stay. In the extreme immaturity sub-group the length of stay was 117.5 days with Respiratory Syncytial Virus and 51.3 days without Respiratory Syncytial Virus (p = 0.0002). In the low birth weight or other preterm sub-group the length of stay with Respiratory Syncytial Virus was 69.2 and without Respiratory Syncytial Virus 14.7 days (p < 0.0001). The observed low rate for nosocomial Respiratory Syncytial Virus (0.46/1000 admissions) should be regarded as a minimum. The increased length of stay in infants with Respiratory Syncytial Virus infection emphasises that units should have guidelines to prevent and deal with Respiratory Syncytial Virus outbreaks.

Acellular pertussis vaccine given by accelerated schedule: response of preterm infants.

OBJECTIVE: To describe the immune response of preterm infants to a diphtheria/tetanus/three component acellular pertussis (DTaP) vaccine, under an accelerated schedule, and the effects of steroids on this response. To compare responses with those of term infants. DESIGN: Prospective observational study. SETTING: Five Wessex neonatal units; Hertfordshire immunisation clinics. PATIENTS: Infants born at < 32 weeks; term controls. INTERVENTIONS: DTaP-Haemophilus influenzae type b vaccine given at 2, 3, and 4 months. Blood taken to assess antibody responses to vaccines. MAIN OUTCOME MEASURES: IgG geometric mean concentrations (GMC) to vaccines. RESULTS: A total of 130 preterm (mean gestational age 29.1 weeks) and 54 term infants were recruited. After the third immunisation, preterm infants had similar GMCs to controls to diphtheria, tetanus, filamentous haemagglutinin (FHA), and pertactin (PRN), but a significantly lower GMC to pertussis toxin (PT). Responses to tetanus and PRN increased with age at the third immunisation, and those to tetanus, FHA, PRN, and PT increased with gestational age at birth. Response to tetanus correlated negatively with the number of doses of antenatal steroids received. There was no association between responses and postnatal steroids. CONCLUSION: When immunised with a combined acellular pertussis- H influenzae type b vaccine under an accelerated schedule, IgG GMC of preterm infants to PT was reduced. GMCs to tetanus, FHA, PRN, and PT increased with gestational age at birth, and GMCs to tetanus and PRN increased with age at the third immunisation. There is, however, no benefit in delaying immunisation. Anti-tetanus IgG decreased with increasing number of doses of antenatal steroids. There was no effect for postnatal steroids.

Congenital adrenal hypoplasia presenting as a chronic respiratory condition.

We describe two children with oxygen dependence, which resolved when congenital adrenal hypoplasia was diagnosed and treatment initiated. Chronic respiratory distress can be a symptom of adrenal hypoplasia and this should be taken into consideration when investigating a child with unexplained chronic respiratory difficulties. Respiratory symptoms resolve very quickly when the underlying condition is recognised and treated.

Detection of heat-stable antigens of Campylobacter jejuni and C. coli by direct agglutination and passive hemagglutination.

The two serotyping schemes for the detection of heat-stable antigens of Campylobacter jejuni and Campylobacter coli use the same strains for antiserum production but differ in the detection systems used for identifying agglutination. The Penner method uses passive hemagglutination (PHA) while the Laboratory of Enteric Pathogens method uses the same antisera but in a whole-bacterial-cell direct agglutination (DA) protocol. C. jejuni produces a polysaccharide capsule, which is antigenic, and is the main component detected by the PHA method. The DA method will detect both capsule antigens and lipopolysaccharide (LPS) or lipooligosaccharide (LOS) surface antigens. Comparison of both methods by using a selection of isolates from human infection has shown a range of variation in agglutination specificity, reflecting the differences in antigens detected by the two methods. While 27.4% of the 416 C. jejuni isolates reacted with the antisera raised against the same type strains by either method, the majority showed a range of more complex relationships. None of the 37 C. coli isolates reacted with the same antiserum by both methods. Together the two schemes gave a total of 102 distinct combined serogroups for C. jejuni and 16 for C. coli. Thus, while some clonally related isolates share the same capsule and LOS or LPS antigens, other strains appear to have a common capsule antigen but differ in their LPS or LOS structures or vice versa.

Immune response of premature infants to meningococcal serogroup C and combined diphtheria-tetanus toxoids-acellular pertussis-Haemophilus influenzae type b conjugate vaccines.

To determine the immune response of premature infants to meningococcal serogroup C capsular polysaccharide (MCC) and combined diphtheria-tetanus toxoids-acellular pertussis-Haemophilus influenzae type b (DTaP-Hib) conjugate vaccines, 105 infants born at <32 weeks' gestation had Hib IgG geometric mean concentrations (GMCs) and MCC serum bactericidal antibody (SBA) geometric mean titers (GMTs) measured 1 month after the third immunization. Term infants served as control subjects. Premature infants had Hib GMCs of 0.27 microg/mL, with 21% achieving GMCs >1.0 microg/mL, compared with 0.81 microg/mL and 46% in term infants (P<.001 and P=.003, respectively). The MCC SBA GMT was 398, with 99% achieving an SBA > or =8, compared with 380 and 98% in term infants (P=.84 and P=1.0, respectively). Hib IgG was associated with age at third immunization (P<.001). When combined with the DTaP vaccine used in this study, the Hib GMC of premature infants was extremely low. The SBA GMT to MCC was similar to that of term infants.

Coinfection with Campylobacter species: an epidemiological problem?

AIMS: To determine the frequency of coinfection with multiple strains in sporadic cases of human Campylobacter infection. METHOD AND RESULTS: During 1999 10 single colonies of Campylobacter were cultured from each of 53 positive faecal samples. Five isolates were taken from nonselective agar after passive filtration of faecal suspensions and five isolates were taken from selective agar plates. All isolates were sero- and phage typed and their antibiotic resistance determined. Pulsed-field gel electrophoresis and flagellin gene typing were performed on selected isolates. One patient was infected with Camp. coli, the remainder with strains of Camp. jejuni. The majority of patients was infected with a single strain of Campylobacter, but from each of four samples, 7.5%, two strains of Camp. jejuni, confirmed by molecular typing, were identified. CONCLUSION: Coinfection occurs in sporadic cases of campylobacteriosis. SIGNIFICANCE AND IMPACT OF THE STUDY: This study has implications in outbreak investigation when distinct strains have been isolated from epidemiologically related patients and/or the suspected source or vehicle.

Cost-effectiveness of salmeterol/fluticasone propionate combination product 50/250 microg twice daily and budesonide 800 microg twice daily in the treatment of adults and adolescents with asthma. International Study Group.

Despite a good understanding of the disease and its treatments, asthma continues to place a large economic burden on healthcare systems. As such, it is important to consider the economic impact of alternative therapeutic options for the treatment of this condition to ensure that scarce resources are used in the most efficient manner possible. Thus, the aim of asthma management from an economic perspective is to reduce the burden of this disease through maximizing health gain with available resources. A prospective economic analysis was conducted as part of a multicentre, randomized, double-blind, comparative trial of salmeterol/fluticasone propionate combination product (SFC) 50/250 microg twice daily vs. budesonide (800 microg twice daily) in adults and adolescents with asthma who were symptomatic despite treatment with inhaled corticosteroids at doses of 800-1200 microg day(-1). Treatment effectiveness was measured in terms of successfully-treated weeks, defined as a > or =5% improvement in morning peak expiratory flow, episode-free days (a day without the need for rescue medication, no nocturnal awakening or adverse events) and symptom-free days. Cost-effectiveness analyses were performed using direct healthcare and drug costs, from the perspective of the Swedish healthcare system (1998 prices), with appropriate sensitivity analyses to test the robustness of the findings. Overall, SFC produced significantly higher (P<0.001) proportions of successfully-treated weeks, episode-free days and symptom-free days. Direct asthma management costs were similar between the two groups [SEK19.6 ($US2.4) for SFC vs. SEK18.5 (SUS2.2) for budesonide]. The cost per successfully-treated week was lower for SFC than for budesonide [SEK204 ($US24.8) vs. SEK300 ($US36.4) per week], as were the costs per episode-free day [SEK51.1 ($US6.2) vs. SEK75.1 ($US9.1) per day] and symptom-free day [SEK42.2 ($US5.1) vs. SEK53.0 ($US6.4) per day]. Incremental cost-effectiveness ratios showed that the additional costs to achieve additional benefits with SFC were minimal. Costs per additional successfully-treated week, symptom-free day and episode-free day with SFC were SEK31.6 ($US3.9), SEK9.2 ($US1.1) and SEK7.7 ($US0.9), respectively, relative to budesonide. Sensitivity analysis showed that the results were stable over a wide range of assumptions. The results suggest that SFC is a more cost-effective treatment than budesonide in the management of moderate to severe asthma.

Children with neurological disorders do not always need fundoplication concomitant with percutaneous endoscopic gastrostomy.

Whether antireflux surgery should be routinely performed at the time of gastrostomy in children with neurological disorders is debatable because of the risk of gastroesophageal reflux. Some argue that these children should be screened for occult gastroesophageal reflux as this will determine the need for fundoplication. This study retrospectively examines outcome in 29 children with neurological disorders who underwent percutaneous endoscopic gastrostomy (PEG) without concomitant fundoplication. Children were included if they had no clinical evidence of severe gastroesophageal reflux before PEG insertion. The median age of children at PEG insertion was 5.6 years (range 1.1 to 18.0). The children were followed for a median of 2.6 years (range 0.4 to 4.9). Insertion of PEG was technically impossible in two children; and an asymptomatic gastrocolic fistula in another child led to subsequent tube removal. Fourteen of the 26 remaining children developed symptomatic gastroesophageal reflux after PEG; five of these showed no reflux on pH monitoring prePEG. Control of symptoms was achieved by medical intervention in 12, but two required fundoplication. Our findings indicate that in the child with neurological disabilities without symptoms indicating severe gastroesophageal reflux, fundoplication is unlikely to be necessary as a consequence of PEG insertion. We conclude that routine investigation for gastroesophageal reflux in the child without severe vomiting can be avoided and the number of antireflux procedures reduced.

Cost-efficacy comparison of inhaled fluticasone propionate and budesonide in the treatment of asthma.

BACKGROUND: The results of a recent meta-analysis comparing 2 inhaled corticosteroids, fluticasone propionate (FP) and budesonide, demonstrated that FP had an improved efficacy-to-safety ratio compared with budesonide. However, limited data are available on the relative economic benefits of these 2 regimens. OBJECTIVE: This pharmacoeconomic analysis used individual patient data from studies in the meta-analysis to compare the relative cost-efficacy of 2 asthma regimens from the perspective of a US third-party payer. METHODS: This analysis included all 7 studies in the meta-analysis that compared budesonide with FP dosed at approximately half the dose of budesonide and that included measurement of daily morning peak expiratory flow (PEF). RESULTS: The total daily per-person cost of asthma management was higher for patients treated with budesonide than with FP ($3.00 vs $2.25, respectively). Treatment with FP had greater cost-efficacy than treatment with budesonide, based on a range of outcome measures that included improvement in morning PEF, symptom-free days, and episode-free days. The daily cost per effectively treated patient (an increase in PEF of > or = 10%) was $5.62 with FP and $10.05 with budesonide. The cost per symptom-free day was $4.36 with FP, compared with $6.67 with budesonide. The cost per episode-free day was $5.60 with FP and $9.42 with budesonide. The pharmacoeconomic difference continued to favor FP as the criteria for success were made more stringent and the cost of budesonide was lowered. CONCLUSION: Based on data from the 7 randomized, controlled trials, treatment of asthma with FP was more effective and less expensive, using US health care assumptions and costs, than treatment with budesonide.

Timing of immunisation of premature infants on the neonatal unit and after discharge to the community.

Premature infants discharged to the community are having their primary immunisations delayed and this delay increases with subsequent doses. The importance and safety of immunising premature infants should be stressed to parents, health visitors, and general practitioners.