Sand fly synthetic sex-aggregation pheromone co-located with insecticide reduces the incidence of infection in the canine reservoir of visceral leishmaniasis: A stratified cluster randomised trial

OBJECTIVE

To evaluate the efficacy of a synthetic sex-aggregation pheromone of the sand fly vector Lu. longipalpis, co-located with residual insecticide, to reduce the infection incidence of Leishmania infantum in the canine reservoir.

METHODS

A stratified cluster randomised trial was designed to detect a 50% reduction in canine incident infection after 24 months in 42 recruited clusters, randomly assigned to one of three intervention arms (14 cluster each): synthetic pheromone + insecticide, insecticide-impregnated dog collars, or placebo control. Infection incidence was measured by seroconversion to anti-Leishmania serum antibody, Leishmania parasite detection and canine tissue parasite loads. Changes in relative Lu. longipalpis abundance within households were measured by setting three CDC light traps per household.

RESULTS

A total 1,454 seronegative dogs were followed-up for a median 15.2 (95% C.I.s: 14.6, 16.2) months per cluster. The pheromone + insecticide intervention provided 13% (95% C.I. 0%, 44.0%) protection against anti-Leishmania antibody seroconversion, 52% (95% C.I. 6.2%, 74·9%) against parasite infection, reduced tissue parasite loads by 53% (95% C.I. 5.4%, 76.7%), and reduced household female sand fly abundance by 49% (95% C.I. 8.2%, 71.3%). Variation in the efficacy against seroconversion varied between trial strata. Equivalent protection attributed to the impregnated-collars were 36% (95% C.I. 14.4%, 51.8%), 23% (95% C.I. 0%, 57·5%), 48% (95% C.I. 0%, 73.4%) and 43% (95% C.I. 0%, 67.9%), respectively. Comparison of the two interventions showed no statistically consistent differences in their efficacies; however, the errors were broad for all outcomes. Reductions in sand fly numbers were predominant where insecticide was located (chicken and dog sleeping sites), with no evidence of insecticide-induced repellence onto humans or dogs.

CONCLUSION

The synthetic pheromone co-located with insecticide provides protection particularly against canine L. infantum parasite transmission and sand fly vector abundance. The effect estimates are not dissimilar to those of the insecticide-impregnated collars, which are documented to reduce canine infection incidence, human infection and clinical VL disease incidence, in different global regions. The trialled novel lure-and-kill approach is a low-cost potential vector control tool against ZVL in the Americas.

Susceptibility of wild-caught Lutzomyia longipalpis (Diptera: Psychodidae) sand flies to insecticide after an extended period of exposure in western São Paulo, Brazil

BACKGROUND

In Brazil, members of the sand fly species complex Lutzomyia longipalpis transmit Leishmania infantum, a protist parasite that causes visceral leishmaniasis. Male Lu. longipalpis produce a sex pheromone that is attractive to both females and males. During a cluster randomised trial, to determine the combined effect of synthetic sex-aggregation pheromone and insecticide on Le. infantum transmission Lu. longipalpis had been continuously exposed to insecticide for 30 months. The objective of this study was to determine the effect of continuous exposure to the insecticides used in the trial on the susceptibility of Lu. longipalpis population.

METHODS

During the trial the sand flies had been exposed to either lambda-cyhalothrin [pheromone + residual insecticide spray (PI)], deltamethrin [dog collars (DC)] or no insecticide [control (C)], for 30 months (November 2012 to April 2015). The insecticide treatment regime was kept in place for an additional 12 months (May 2015-April 2016) during this susceptibility study. Sand flies collected from the field were exposed to WHO insecticide-impregnated papers cyhalothrin (0.05%), deltamethrin (0.5%) and control (silicone oil) in a modified WHO insecticide exposure trial to determine their susceptibility.

RESULTS

We collected 788 Lu. longipalpis using CDC-light traps in 31 municipalities across the three trial arms. Probit analysis showed that the knockdown times (KDTs) of Lu. longipalpis collected from the lambda-cyhalothrin exposed PI-arm [KDT50: 31.1 min, confidence interval (CI): 29.6-32.6 and KDT90: 44.2 min, CI: 42.1-46.7] were longer than the KDTs from the non-insecticide-treated C-arm (KDT50: 26.3 min, CI: 25.1-27.6 and KDT90: 38.2, CI: 36.5-40.2) (no-overlapping 95% CIs). KDTs of Lu. longipalpis collected from the deltamethrin exposed DC-arm had similar values (KDT50: 13.7 min, CI: 10.1-16.2 and KDT90: 26.7 min, CI: 21.8-30.6) to those for the C-arm (KDT50: 13.5 min; CI: 12.2-14.8 and KDT90: 23.2 min, CI: 21.4-25.4) (overlapping CIs). The wild-caught unexposed Lu. longipalpis (C-arm), took approximately twice as long to knock down as laboratory-colonised specimens for both insecticides.

CONCLUSIONS

Our study reveals slight changes in KDT, in sand flies after prolonged exposure to lambda-cyhalothrin in the presence of pheromone. These changes are not considered to have reached the reference levels indicative of resistance in sand flies suggesting that pheromone and insecticide treatment at the level indicated in this study do not constitute a significant risk of increased insecticide resistance. Prolonged exposure to deltamethrin in dog collars did not result in changes to KDT.

Attraction of Lutzomyia longipalpis to synthetic sex-aggregation pheromone: Effect of release rate and proximity of adjacent pheromone sources

In South America, the Protist parasite that causes visceral leishmaniasis, a potentially fatal human disease, is transmitted by blood-feeding female Lutzomyia longipalpis sand flies. A synthetic copy of the male produced sex-aggregation pheromone offers new opportunities for vector control applications. We have previously shown that the pheromone placed in plastic sachets (lures) can attract both females and males to insecticide treated sites for up to 3 months. To use the pheromone lure in a control program we need to understand how the application of lures in the field can be optimised. In this study we investigated the effect of increasing the number of lures and their proximity to each other on their ability to attract Lu. longipalpis. Also for the first time we applied a Bayesian log-linear model rather than a classic simple (deterministic) log-linear model to fully exploit the field-collected data. We found that sand fly response to pheromone is significantly related to the quantity of pheromone and is not influenced by the proximity of other pheromone sources. Thus sand flies are attracted to the pheromone source at a non-linear rate determined by the amount of pheromone being released. This rate is independent of the proximity of other pheromone releasing traps and indicates the role of the pheromone in aggregation formation. These results have important implications for optimisation of the pheromone as a vector control tool and indicate that multiple lures placed in relatively close proximity to each other (5 m apart) are unlikely to interfere with one another.

Lutzomyia longipalpis sand flies are the insect vectors of the Protist parasite Leishmania infantum which causes visceral leishmaniasis (VL) in Brazil. Control of VL has focussed on vector and infected reservoir control, but despite the sustained efforts of the Brazilian Health authorities the disease burden doubled between 1990 to 2016. New approaches to VL control are urgently needed. We previously demonstrated that Lu. longipalpis synthetic sex-aggregation pheromone placed alongside insecticide sprayed surfaces can attract and kill female sand flies. However, before the synthetic pheromone can be effectively exploited in any VL control program it is essential to understand how it might be deployed. In this study we investigated the effect of different amounts of pheromone and the spatial relationship between different pheromone sources on Lu. longipalpis catches. We developed a robust Bayesian analysis to fully exploit the field data which showed that optimal use of the pheromone could be achieved by placing individual or small numbers of pheromone releasing devices (lures) within the peridomestic environment and these can be positioned relatively closely without competing with each other. The results also revealed the significance of the pheromone in maintaining aggregations of Lu. longipalpis and suggested that Lu. longipalpis may be more evenly distributed in the peridomestic environment than previously recognised.

Does the diurnal pattern of enteric methane emissions from dairy cows change over time?

Diet manipulation and genetic selection are two important mitigation strategies for reducing enteric methane (CH4) emissions from ruminant livestock. The aim of this study was to assess whether the diurnal pattern of CH4 emissions from individual dairy cows changes over time when cows are fed on diets varying in forage composition. Emissions of CH4 from 36 cows were measured during milking in an automatic (robotic) milking station in three consecutive feeding periods, for a total of 84 days. In Periods 1 and 2, the 36 cows were fed a high-forage partial mixed ration (PMR) containing 75% forage, with either a high grass silage or high maize silage content. In Period 3, cows were fed a commercial PMR containing 69% forage. Cows were offered PMR ad libitum plus concentrates during milking and CH4 emitted by individual cows was sampled during 8662 milkings. A linear mixed model was used to assess differences among cows, feeding periods and time of day. Considerable variation was observed among cows in daily mean and diurnal patterns of CH4 emissions. On average, cows produced less CH4 when fed on the commercial PMR in feeding Period 3 than when the same cows were fed on high-forage diets in feeding Periods 1 and 2. The average diurnal pattern for CH4 emissions did not significantly change between feeding periods and as lactation progressed. Emissions of CH4 were positively associated with dry matter (DM) intake and forage DM intake. It is concluded that if the management of feed allocation remains constant then the diurnal pattern of CH4 emissions from dairy cows will not necessarily alter over time. A change in diet composition may bring about an increase or decrease in absolute emissions over a 24-h period without significantly changing the diurnal pattern unless management of feed allocation changes. These findings are important for CH4 monitoring techniques that involve taking measurements over short periods within a day rather than complete 24-h observations.

A temporal comparison of sex-aggregation pheromone gland content and dynamics of release in three members of the Lutzomyia longipalpis (Diptera: Psychodidae) species complex

Background

Lutzomyia longipalpis is the South American vector of Leishmania infantum, the etiologic agent of visceral leishmaniasis (VL). Male L. longipalpis produce a sex-aggregation pheromone that is critical in mating, yet very little is known about its accumulation over time or factors involved in release. This laboratory study aimed to compare accumulation of pheromone over time and determine factors that might influence release in three members of the L. longipalpis species complex.

Methodology/Principal findings

We investigated male sex-aggregation pheromone gland content at different ages and the release rate of pheromone in the presence or absence of females under different light conditions by gas chromatography-mass spectrometry (GC-MS). Pheromone gland content was determined by extraction of whole males and pheromone release rate was determined by collection of headspace volatiles. Pheromone gland content appeared age-related and pheromone began to accumulate between 6 to 12 h post eclosion and gradually increased until males were 7–9 days old. The greatest amount was detected in 9-day old Campo Grande males ((S)-9-methylgermacrene-B; X ± SE: 203.5 ± 57.4 ng/male) followed by Sobral 2S males (diterpene; 199.9 ± 34.3) and Jacobina males ((1S,3S,7R)-3-methyl-α-himachalene; 128.8 ± 30.3) at 7 days old. Pheromone release was not continuous over time. During a 4-hour period, the greatest quantities of pheromone were released during the first hour, when wing beating activity was most intense. It was then substantially diminished for the remainder of the time. During a 24 h period, 4–5 day old male sand flies released approximately 63 ± 11% of the pheromone content of their glands, depending on the chemotype. The presence of females significantly increased pheromone release rate. The light regime under which the sand flies were held had little influence on pheromone release except on Sobral 2S chemotype.

Conclusions/Significance

Accumulation of pheromone appears to occur at different rates in the different chemotypes examined and results in differing amounts being present in glands over time. Release of accumulated pheromone is not passive, but depends on biotic (presence of females) and abiotic (light) circumstances. There are marked differences in content and release between the members of the complex suggesting important behavioural, biosynthetic and ecological differences between them.

The Dipteran subfamily Phlebotominae includes the genera Lutzomyia and Phlebotomus among which several species are important vectors of parasitic and bacterial pathogens. The sand fly Lutzomyia longipalpis is considered the main vector of visceral leishmaniasis (VL) in the New World. Based on the main component of the male sex-aggregation pheromone gland, different sex pheromone-producing populations (chemotypes) of L. longipalpis are recognized in Brazil. Given the importance of the sex-aggregation pheromones in the biology of this species complex, we present here the first attempt to study how pheromone accumulates in the glands over time and factors that might influence its release in the three most common chemotypes from Brazil. Our results demonstrated that pheromone first starts to accumulate a few hours post-eclosion (6–12 h) and this continues over 15 days. Pheromone release is a dynamic process which varies between the 3 chemotypes depending on biotic factors, such as light regime and presence/absence of conspecific females. This work provides valuable information, critical to our understanding of the behaviour and ecology of L. longipalpis sand flies and which will contribute to investigations to improve field-based pheromone control and monitoring of L. longipalpis sand flies.

Limb reconstruction in Ollier's disease

We present our experience of lengthening and correction of complex deformities in the management of patients with Ollier’s dysplasia (multiple enchondromatosis) from 1985 and 2002. All patients were under 18 years with a minimum follow-up time of 2 years (mean 9.6 years, range 2–15 years). There were a total of ten patients of which seven were male and three female. The mean age at presentation was 10.7 years (range 5–17 years; SD 3.7 years). The total length gain was 42.3 mm (range 30–110 mm; SD 28.9 mm). The number of days in external fixation was 164.8 days (range 76–244 days; SD 42.9 days). The bone healing index was 32.5 days/cm (18–50 days/cm; SD 10.3 days/cm). Patients with Ollier’s disease have limb length inequality and angular deformities and require multiple reconstructive procedures owing to a high incidence of recurrence. We identified a tendency for the osteotomy to prematurely consolidate and advise the latency period after surgery to be 4–5 days and for distraction to proceed at a faster rate.

Nitrous oxide emissions from cattle excreta applied to a Scottish grassland: effects of soil and climatic conditions and a nitrification inhibitor

Dung and urine excreted onto grasslands are a major source of nitrous oxide (N2O). These N2O emissions stem from inefficient utilisation of nitrogen (N) ingested by ruminants, and the inability of pasture to utilise the deposited N. Predicted growth in dairy and meat consumption means that there is a requirement to quantify N2O emissions, and investigate emission reduction mechanisms. Three 12 month 'seasonal' experiments were undertaken at Crichton, SW Scotland, where N2O emissions were measured from applications of cattle urine, dung, artificial urine and urine+a nitrification inhibitor (NI), dicyandiamide (DCD). The three application timings were 'spring', 'summer' and 'autumn', representative of early-, mid- and late grazing seasons. N2O emissions were measured from static chambers for 12 months. The aim was to quantify emissions from cattle excreta, and determine their dependence on the season of application, and the respective contribution of dung and urine to total excreta emissions. Measurement from NI amended urine was made to assess DCD's potential as an emission mitigation tool. Emissions were compared to the IPCC's default emission factor (EF) of 2% for cattle excreted N. Mean annual cumulative emissions from urine were the highest when applied in summer (5034 g N2O-N ha(-1)), with lower emissions from spring (1903 g N2O-N ha(-1)) and autumn (2014 g N2O-N ha(-1)) application, most likely due to higher temperatures and soil moisture conducive to both nitrification and denitrification in the summer months. Calculated EFs were significantly greater from urine (1.1%) than dung (0.2%) when excreta was applied in summer, and EFs varied with season of application, but in all experiments were lower than the IPCC default of 2%. These results support both lowering and disaggregating this EF into individual EFs for dung and urine. Addition of DCD to urine caused no significant reduction in emissions, suggesting that more research is required into its use as a mitigation option.

Glycaemic control is harder to achieve than blood pressure or lipid control in Irish adults with type 1 diabetes

We sought to determine the attainment of targets for glycaemic control and vascular risk reduction in an Irish cohort of T1DM adults. Of 797 patients (53% male, mean age 40.3 ± 14.8 years, HbA1c 8.5 ± 1.6% (69.6 ± 17.8 mmol mol(-1))), 15%, 68% and 62% achieved targets for HbA1c, blood pressure and LDL cholesterol, respectively.

Increased CSF concentrations of myelin basic protein after TBI in infants and children: absence of significant effect of therapeutic hypothermia

BACKGROUND

The objectives of this study were to determine effects of severe traumatic brain injury (TBI) on cerebrospinal fluid (CSF) concentrations of myelin basic protein (MBP) and to assess relationships between clinical variables and CSF MBP concentrations.

METHODS

We measured serial CSF MBP concentrations in children enrolled in a randomized controlled trial evaluating therapeutic hypothermia (TH) after severe pediatric TBI. Control CSF was obtained from children evaluated, but found not to be having CNS infection. Generalized estimating equation models and Wilcoxon Rank-Sum test were used for comparisons of MBP concentrations.

RESULTS

There were 27 TBI cases and 57 controls. Overall mean (± SEM) TBI case MBP concentrations for 5 days after injury were markedly greater than controls (50.49 ± 6.97 vs. 0.11 ± 0.01 ng/ml, p < 0.01). Mean MBP concentrations were lower in TBI patients <1 year versus >1 year (9.18 ± 1.67 vs. 60.22 ± 8.26 ng/ml, p = 0.03), as well as in cases with abusive head trauma (AHT) versus non-abusive TBI (14.46 ± 3.15 vs. 61.17 ± 8.65 ng/ml, p = 0.03). TH did not affect MBP concentrations.

CONCLUSIONS

Mean CSF MBP increases markedly after severe pediatric TBI, but is not affected by TH. Infancy and AHT are associated with low MBP concentrations, suggesting that age-dependent myelination influences MBP concentrations after injury. Given the magnitude of MBP increases, axonal injury likely represents an important therapeutic target in pediatric TBI.

The effect of improving cow productivity, fertility, and longevity on the global warming potential of dairy systems

This study compared the environmental impact of a range of dairy production systems in terms of their global warming potential (GWP, expressed as carbon dioxide equivalents, CO(2)-eq.) and associated land use, and explored the efficacy of reducing said impact. Models were developed using the unique data generated from a long-term genetic line × feeding system experiment. Holstein-Friesian cows were selected to represent the UK average for milk fat plus protein production (control line) or were selected for increased milk fat plus protein production (select line). In addition, cows received a low forage diet (50% forage) with no grazing or were on a high forage (75% forage) diet with summer grazing. A Markov chain approach was used to describe the herd structure and help estimate the GWP per year and land required per cow for the 4 alternative systems and the herd average using a partial life cycle assessment. The CO(2)-eq. emissions were expressed per kilogram of energy-corrected milk (ECM) and per hectare of land use, as well as land required per kilogram of ECM. The effects of a phenotypic and genetic standard deviation unit improvement on herd feed utilization efficiency, ECM yield, calving interval length, and incidence of involuntary culling were assessed. The low forage (nongrazing) feeding system with select cows produced the lowest CO(2)-eq. emissions of 1.1 kg/kg of ECM and land use of 0.65 m(2)/kg of ECM but the highest CO(2)-eq. emissions of 16.1t/ha of the production systems studied. Within the herd, an improvement of 1 standard deviation in feed utilization efficiency was the only trait of those studied that would significantly reduce the reliance of the farming system on bought-in synthetic fertilizer and concentrate feed, as well as reduce the average CO(2)-eq. emissions and land use of the herd (both by about 6.5%, of which about 4% would be achievable through selective breeding). Within production systems, reductions in CO(2)-eq. emissions per kilogram of ECM and CO(2)-eq. emissions per hectare were also achievable by an improvement in feed utilization. This study allowed development of models that harness the biological trait variation in the animal to improve the environmental impact of the farming system. Genetic selection for efficient feed use for milk production according to feeding system can bring about reductions in system nutrient requirements, CO(2)-eq. emissions, and land use per unit product.

Charcoal addition to soils in NE England: a carbon sink with environmental co-benefits?

Interest in the application of biochar (charcoal produced during the pyrolysis of biomass) to agricultural land is increasing across the world, recognised as a potential way to capture and store atmospheric carbon. Its interest is heightened by its potential co-benefits for soil quality and fertility. The majority of research has however been undertaken in tropical rather than temperate regions. This study assessed the potential for lump-wood charcoal addition (as a substitute for biochar) to soil types which are typically under arable and forest land-use in North East England. The study was undertaken over a 28 week period and found: i) No significant difference in net ecosystem respiration (NER) between soils containing charcoal and those without, other than in week 1 of the trial. ii) A significantly higher dissolved organic carbon (DOC) flux from soils containing large amounts of charcoal than from those untreated, when planted with ryegrass. iii) That when increased respiration or DOC loss did occur, neither was sufficiently large to alter the carbon sink benefits of charcoal application. iv) That charcoal incorporation resulted in a significantly lower nitrate flux in soil leachate from mineral soils. v) That charcoal incorporation caused significant increases in soil pH, from 6.98 to 7.22 on bare arable soils when 87,500 kg charcoal/ha was applied. Consideration of both the carbon sink and environmental benefits observed here suggests that charcoal application to temperate soils typical of North East England should be considered as a method of carbon sequestration. Before large scale land application is encouraged, further large scale trials should be undertaken to confirm the positive results of this research.

Allelic polymorphism in the T cell receptor and its impact on immune responses

In comparison to human leukocyte antigen (HLA) polymorphism, the impact of allelic sequence variation within T cell receptor (TCR) loci is much less understood. Particular TCR loci have been associated with autoimmunity, but the molecular basis for this phenomenon is undefined. We examined the T cell response to an HLA-B*3501-restricted epitope (HPVGEADYFEY) from Epstein-Barr virus (EBV), which is frequently dominated by a TRBV9*01(+) public TCR (TK3). However, the common allelic variant TRBV9*02, which differs by a single amino acid near the CDR2beta loop (Gln55-->His55), was never used in this response. The structure of the TK3 TCR, its allelic variant, and a nonnaturally occurring mutant (Gln55-->Ala55) in complex with HLA-B*3501(HPVGEADYFEY) revealed that the Gln55-->His55 polymorphism affected the charge complementarity at the TCR-peptide-MHC interface, resulting in reduced functional recognition of the cognate and naturally occurring variants of this EBV peptide. Thus, polymorphism in the TCR loci may contribute toward variability in immune responses and the outcome of infection.

Assessing the probability of carbon and greenhouse gas benefit from the management of peat soils

This study proposes a method for assessing the probability that land management interventions will lead to an improvement in the carbon sink represented by peat soils. The method is able to: combine studies of different carbon uptake and release pathways in order to assess changes on the overall carbon or greenhouse gas budget; calculate the probability of the management or restoration leading to an improvement in the budget; calculate the uncertainty in that probability estimate; estimate the equivalent number of complete budgets available from the combination of the literature; test the difference in the outcome of different land management interventions; and provide a method for updating the predicted probabilities as new studies become available. Using this methodology, this study considered the impact of: afforestation, managed burning, drainage, drain-blocking, grazing removal; and revegetation, on the carbon budget of peat soils in the UK. The study showed that afforestation, drain-blocking, revegetation, grazing removal and cessation of managed burning would bring a carbon benefit, whereas deforestation, managed burning and drainage would bring a disbenefit. The predicted probabilities of a benefit are often equivocal as each management type or restoration often leads to increase in uptake in one pathway while increasing losses in another.

Strains of Epstein-Barr virus infecting multiple sclerosis patients

Both epidemiological and experimental studies have indicated that the ubiquitous herpesvirus Epstein-Barr virus (EBV) plays a role in the pathogenesis of multiple sclerosis (MS). Some features of MS epidemiology, such as the decline in risk among migrants from high to low MS prevalence areas, suggest the presence of variant EBV strains that increase MS risk. The objective of this study was to investigate whether genetic variability in EBV is associated with MS. Genes encoding for two EBV antigens (EBNA1 and BRRF2) were sequenced in EBV isolates from 40 MS patients and a similar number of control subjects. These viral antigens were chosen for analysis because they are known to stimulate atypical immune responses in MS. Extensive sequence polymorphism was observed within the EBNA1 and BRRF2 genes in isolates from both MS patients and controls. Interestingly, several single nucleotide polymorphisms within the EBNA1 gene, and one within the BRRF2 gene, were found to occur at marginally different frequencies in EBV strains infecting MS patients versus controls. Although this study does not find a simple causal relationship between EBV strains and the occurrence of MS, the existence of haplotypes that occur at different frequencies in MS patients versus controls may provide an area for future study of the role of EBV strain variation in multiple sclerosis.

The shaping of T cell receptor recognition by self-tolerance

During selection of the T cell repertoire, the immune system navigates the subtle distinction between self-restriction and self-tolerance, yet how this is achieved is unclear. Here we describe how self-tolerance toward a trans-HLA (human leukocyte antigen) allotype shapes T cell receptor (TCR) recognition of an Epstein-Barr virus (EBV) determinant (FLRGRAYGL). The recognition of HLA-B8-FLRGRAYGL by two archetypal TCRs was compared. One was a publicly selected TCR, LC13, that is alloreactive with HLA-B44; the other, CF34, lacks HLA-B44 reactivity because it arises when HLA-B44 is coinherited in trans with HLA-B8. Whereas the alloreactive LC13 TCR docked at the C terminus of HLA-B8-FLRGRAYGL, the CF34 TCR docked at the N terminus of HLA-B8-FLRGRAYGL, which coincided with a polymorphic region between HLA-B8 and HLA-B44. The markedly contrasting footprints of the LC13 and CF34 TCRs provided a portrait of how self-tolerance shapes the specificity of TCRs selected into the immune repertoire.

The peptide length specificity of some HLA class I alleles is very broad and includes peptides of up to 25 amino acids in length

The major ligands presented by MHC class I molecules after natural antigen processing are peptides of eight to ten residues in length, and it is widely accepted that the binding preferences of MHC class I molecules play a dominant role in dictating this classic feature of antigen presentation. In this report, we have reassessed the peptide size specificity of class I human leukocyte antigens (HLAs). By lengthening previously defined T cell epitopes by central amino acid insertion, we demonstrate that the peptide length specificity of some common HLA class I alleles (HLA-B*3501, B*0702 and A*2402) is very broad, and includes peptides of up to 25 residues. These data suggest that the length limitation of naturally processed MHC class I-associated peptides is primarily controlled by peptide availability after antigen processing rather than the binding specificity of MHC class I molecules. Furthermore, the findings provide an explanation for recent reports highlighting that epitopes of >10 amino acids play a minor but significant role in virus-specific immune surveillance by CD8(+) T cells.

Natural micropolymorphism in human leukocyte antigens provides a basis for genetic control of antigen recognition

Human leukocyte antigen (HLA) gene polymorphism plays a critical role in protective immunity, disease susceptibility, autoimmunity, and drug hypersensitivity, yet the basis of how HLA polymorphism influences T cell receptor (TCR) recognition is unclear. We examined how a natural micropolymorphism in HLA-B44, an important and large HLA allelic family, affected antigen recognition. T cell–mediated immunity to an Epstein-Barr virus determinant (EENLLDFVRF) is enhanced when HLA-B*4405 was the presenting allotype compared with HLA-B*4402 or HLA-B*4403, each of which differ by just one amino acid. The micropolymorphism in these HLA-B44 allotypes altered the mode of binding and dynamics of the bound viral epitope. The structure of the TCR–HLA-B*4405^EENLLDFVRF complex revealed that peptide flexibility was a critical parameter in enabling preferential engagement with HLA-B*4405 in comparison to HLA-B*4402/03. Accordingly, major histocompatibility complex (MHC) polymorphism can alter the dynamics of the peptide-MHC landscape, resulting in fine-tuning of T cell responses between closely related allotypes.

Widespread sequence variation in Epstein-Barr virus nuclear antigen 1 influences the antiviral T cell response

Epstein-Barr virus (EBV) nuclear antigen (EBNA) 1 is perhaps the most widely studied EBV protein, because of its critical role in maintaining the EBV episome and its expression in all EBV-associated malignancies. Much of this research has focused exclusively on the EBV wild-type (wt) strain (B95-8). Sequence analysis of the gene encoding for EBNA1 in EBV isolates from 43 Caucasians has now revealed considerable EBNA1 sequence divergence from the EBV wt strain in the majority of isolates from this population group. Importantly, T cell recognition of an endogenously processed HLA-B8 - binding EBNA1 epitope was greatly influenced by this sequence polymorphism.

The development, implementation and testing of a lameness control programme based on HACCP principles and designed for heifers on dairy farms

This paper describes the development and testing of a lameness control programme (LCP) for heifers on dairy farms. The LCP, which is based on the analysis of hazards and critical control points (HACCP), was tested via a randomised intervention study on 60 farms. Tangible hazards for each farm were identified, allotted to 11 categories of proximate hazard and scored on each farm to quantify the risks presented by each hazard. Feet were inspected for signs of claw horn disease and infection, such as digital dermatitis. Intervention was generally ineffective, primarily through failure to implement the LCP. However, retrospective analysis was able to demonstrate highly significant associations between risks attached to proximate hazards and probabilities of lameness and foot lesions, allowing the severity of these hazards to be ranked. The most significant proximate hazards of environmental origin were prolonged standing on concrete, standing in wet slurry and factors that cause claw trauma. The most severe proximate hazards however were those associated with failures of management, especially poor claw condition and inadequate foot care. Overall farm risks (OFR) were estimated by summing the products of the generic severity for proximate hazards with on-farm risks. Changes in OFR were significantly related to changes in outcome (lameness and lesions).

Preferential binding of unusually long peptides to MHC class I and its influence on the selection of target peptides for T cell recognition

A classic feature of antigen presentation for CD8+ T cell recognition is that MHC class I molecules generally present peptides of 8-10 amino acids in length. However, recent studies have demonstrated that peptides of >10 residues play a significant role in immune surveillance by T cells restricted by some HLA class I alleles. In the present study, we describe several examples of unusually long viral peptides of 11 or 12 residues, recognized by CTLs in the context of HLA-B35. Interestingly, all these immunogenic peptides completely encompass shorter canonical length sequences that conform to the HLA-B35 binding motif, but which fail to stimulate detectable T cell responses. The mechanism for this phenomenon appears to involve the preferential binding to HLA-B35 of the atypically long CD8+ T cell target peptides over the overlapping canonical length sequences. These data suggest that the peptide length specificity of some HLA class I alleles is broad, allowing peptides of >10 residues to sometimes dominate over canonical length class I ligands as targets for T cell recognition.

The impact of uterine infection on a dairy cow's performance

The aim of this study was to assess the predisposing factors leading to uterine infection in dairy cows and evaluate its impact on the cow's performance. Performance indicators included feed intake, milk fat and protein composition, milk yield, fertility and culling. Data were studied from 2914 completed lactations from the Holstein Friesian Langhill Dairy herd between January 1990 and August 2005. There were 402 cases of uterine infection (from 321 cows) in the Langhill herd, a level of 13.8% during the study period. Calving assistance was highly associated with the incidence of uterine infection (chi(2)=106.63, P<0.001). Failure to conceive (chi(2)=3.89, P<0.05; chi(2)=11.20, P<0.001) and culling (chi(2)=13.66, P<0.001, chi(2)=8.55, P<0.01) were also implicated with calving assistance and uterine infection, respectively. The main predisposing factors related to an incidence of uterine infection were calving assistance, twin births, malpresented calves, and retained placenta. First-time calvers and cows with a shorter gestation length were associated with more cases of uterine infections. Additionally, lower daily dry matter intakes and milk yields during the first 100 days in milk (DIM) were associated with higher incidence levels of uterine infection. Also, a higher incidence level of uterine infection was related to lower milk protein composition from 1 to 21 DIM and a poorer body condition from 101 to 300 DIM. Cows with poorer drying off body condition scores and longer lactation lengths were associated with a higher incidence level of uterine infection. Calving assistance was associated with male and twin births, first-time calvers and cows with oversized calves. Cows with an assisted calving were also associated with an increased number of days from calving to first service. The predisposing factors influencing the occurrence of calving assistance can be influenced by suitable management to reduce the chances of oversized calves, the detrimental effects of twin births (such as calving assistance and retained placentas) and prenatal knowledge of the calf's sex. The occurrence of uterine infection can be reduced by minimising the need for assistance at calving. Assistance should only be carried out when necessary and appropriate hygiene should be used to decrease the incidence of uterine infections from intervention and involuntary culling due to cows failing to conceive.

The impact of HLA-B micropolymorphism outside primary peptide anchor pockets on the CTL response to CMV

The factors controlling epitope selection in the T cell response to persistent viruses are not fully understood, and we have examined this issue in the context of four HLA-B*35-binding peptides from the pp65 antigen of human cytomegalovirus, two of which are previously undescribed. Striking differences in the hierarchy of immunodominance between these four epitopes were observed in healthy virus carriers expressing HLA-B*3501 versus B*3508, two HLA-B allotypes that differ by a single amino acid at position 156 (HLA-B*3501, (156)Leucine; HLA-B*3508, (156)Arginine) that projects from the alpha2 helix into the centre of the peptide-binding groove. While HLA-B*3501(+) individuals responded most strongly to the (123)IPSINVHHY(131) and (366)HPTFTSQY(373) epitopes, HLA-B*3508(+) individuals responded preferentially to (103)CPSQEPMSIYVY(114) and (188)FPTKDVAL(195). By comparing peptide-MHC association and disassociation rates with peptide immunogenicity, it was clear that dissociation rates correlate more closely with the hierarchy of immunodominance among the four pp65 peptides. These findings demonstrate that MHC micropolymorphism at positions outside the primary anchor residue binding pockets can have a major impact on determinant selection in antiviral T cell responses. Such influences may provide the evolutionary pressure that maintains closely related MHC molecules in diverse human populations.

Predictable alphabeta T-cell receptor selection toward an HLA-B*3501-restricted human cytomegalovirus epitope

Human cytomegalovirus (HCMV) elicits a very large burden on the immune system, with approximately one in ten T cells being reserved solely to manage this infection. However, information on the clonotypic composition of these vast T-cell populations is limited. In this study, we sequenced 116 T-cell receptor (TcR) alpha/beta-chains specific for the highly immunogenic HLA-B*3501-resticted epitope IPSINVHHY from the pp65 antigen. Interestingly, T cells recovered from all donors bore an identical or near-identical TRBV28/TRBJ1-4/TRAV17/TRAJ33 TcR. The ability to predict the responding alphabeta TcR repertoire before viral infection should prove a powerful tool for basic and clinical immunology.

Characterization of the Methoxy Carbonyl Radical Formed via Photolysis of Methyl Chloroformate at 193.3 nm

This study investigates two features of interest in recent work on the photolytic production of the methoxy carbonyl radical and its subsequent unimolecular dissociation channels. Earlier studies used methyl chloroformate as a photolytic precursor for the CH3OCO, methoxy carbonyl (or methoxy formyl) radical, which is an intermediate in many reactions that are relevant to combustion and atmospheric chemistry. That work evidenced two competing C-Cl bond fission channels, tentatively assigning them as producing ground- and excited-state methoxy carbonyl radicals. In this study, we measure the photofragment angular distributions for each C-Cl bond fission channel and the spin-orbit state of the Cl atoms produced. The data shows bond fission leading to the production of ground-state methoxy carbonyl radicals with a high kinetic energy release and an angular distribution characterized by an anisotropy parameter, beta, of between 0.37 and 0.64. The bond fission that leads to the production of excited-state radicals, with a low kinetic energy release, has an angular distribution best described by a negative anisotropy parameter. The very different angular distributions suggest that two different excited states of methyl chloroformate lead to the formation of ground- and excited-state methoxy carbonyl products. Moreover, with these measurements we were able to refine the product branching fractions to 82% of the C-Cl bond fission resulting in ground-state radicals and 18% resulting in excited-state radicals. The maximum kinetic energy release of 12 kcal/mol measured for the channel producing excited-state radicals suggests that the adiabatic excitation energy of the radical is less than or equal to 55 kcal/mol, which is lower than the 67.8 kcal/mol calculated by UCCSD(T) methods in this study. The low-lying excited states of methylchloroformate are also considered here to understand the observed angular distributions. Finally, the mechanism for the unimolecular dissociation of the methoxy carbonyl radical to CH3 + CO2, which can occur through a transition state with either cis or, with a much higher barrier, trans geometry, was investigated with natural bond orbital computations. The results suggest donation of electron density from the nonbonding C radical orbital to the sigma* orbital of the breaking C-O bond accounts for the additional stability of the cis transition state.

TCR alpha genes direct MHC restriction in the potent human T cell response to a class I-bound viral epitope

The underlying generic properties of alphabeta TCRs that control MHC restriction remain largely unresolved. To investigate MHC restriction, we have examined the CTL response to a viral epitope that binds promiscuously to two human leukocyte Ags (HLAs) that differ by a single amino acid at position 156. Individuals expressing either HLA-B*3501 (156Leucine) or HLA-B*3508 (156Arginine) showed a potent CTL response to the 407HPVGEADYFEY417 epitope from EBV. Interestingly, the response was characterized by highly restricted TCR beta-chain usage in both HLA-B*3501+ and HLA-B*3508+ individuals; however, this conserved TRBV9+ beta-chain was associated with distinct TCR alpha-chains depending upon the HLA-B*35 allele expressed by the virus-exposed host. Functional assays confirmed that TCR alpha-chain usage determined the HLA restriction of the CTLs. Structural studies revealed significant differences in the mobility of the peptide when bound to HLA-B*3501 or HLA-B*3508. In HLA-B*3501, the bulged section of the peptide was disordered, whereas in HLA-B*3508 the bulged epitope adopted an ordered conformation. Collectively, these data demonstrate not only that mobile MHC-bound peptides can be highly immunogenic but can also stimulate an extremely biased TCR repertoire. In addition, TCR alpha-chain usage is shown to play a critical role in controlling MHC restriction between closely related allomorphs.

Herd health planning: farmers' perceptions in relation to lameness and mastitis

Between December 2002 and December 2003, the herd health planning activities on 61 dairy farms in the uk were compared with several measures of lameness and mastitis. Lameness had been reported as a problem in 53 of the herds directly by the farm and in the other eight by the nominating local veterinary practice; 54 of the farms also reported having a mastitis problem. Fifty-three (87 per cent) of the farms had some form of written herd health plan, of which 21 (40 per cent) had been in place for 12 months or less. All the farms were recording mastitis in some way, although 38 (62 per cent) of the farmers did not review these records and only four retained the results of a comprehensive record review. Farms defined as having a high incidence of mastitis were more likely to be reviewing their health records, but farms defined as having a high prevalence of lameness in a sentinel group of early lactation heifers were less likely to be reviewing their health records.

Housing System, Milk Production, and Zero-Grazing Effects on Lameness and Leg Injury in Dairy Cows

The aim of this study was to assess the effect of grazing (G) vs. zero-grazing (ZG), level of milk production, and quality and type of housing system [free stalls (FS) and straw yards (SY)] on the prevalence of lameness and leg injuries in dairy cows. Observations were made on 37 commercial dairy farms across Great Britain. A single visit of 5 d duration was made to each farm. During this visit, lameness scores and the incidence of swellings, rubs, and injuries to hocks and knees were recorded on all the peak- or mid-lactation cows. Aspects of the quality of housing and management that were likely to affect foot and leg health were recorded. There were more lame cows on ZG farms (39 +/- 0.02%) than on grazing (G) farms (15 +/- 0.01%), and lameness scores were higher on FS farms compared with SY farms (0.25 +/- 0.01 vs. 0.05 +/- 0.01). Cows on SY farms had fewer hock and knee injuries compared with FS farms. The frequency of knee swellings was higher on ZG farms (0.31 +/- 0.02) than on G farms (0.15 +/- 0.01). Aspects of the free-stall design affected foot and leg health. The number of hock swellings increased with increasing stall gradient (0.16 +/- 0.01 with no slope vs. 0.39 +/- 0.02 at a 0 to 1.5% slope). There was an interaction between the length of the free-stall lunging space and the hip width of the cow, indicating that the incidence of lameness is generally highest on farms with small free stalls and heavy cows. High levels of milk production did not affect lameness or leg injury. The results indicate that housing cows throughout the year potentially has a detrimental effect on foot and leg health. However, good free-stall design may reduce lameness and leg lesions.

The socio-economical impact of paediatric fracture clinic appointments

The aim of our study was to quantify the indirect cost of a paediatric fracture clinic appointment on society. Our study took place in a paediatric outpatients department using two questionnaires, completed at the time of attendance. The primary measures were days off work and pay lost for the carer and time out from education of the patient. One hundred consecutive patients were asked to complete a after their appointment. Seventy-one were completed. A second clinic evaluation sheet was completed by the surgeons seeing the patients, to assess the appropriateness of the attendance. The results showed that for every 100 appointments 25 working days were lost and 18 people lost pay. Fifty-four days of school were missed as a direct result of attending clinic for review. We showed that 93% of the clinic attendances were thought to be appropriate from the perspective of the surgeon seeing the patient. Streamlining the aftercare of fractures can relieve this considerable socioeconomic burden.

Transfer of pectoralis major in arthrogryposis to restore elbow flexion: deteriorating results in the long term

We present the long-term results of pectoralis major transfer to restore elbow flexion in seven patients (ten procedures). The early results in all the patients were encouraging but with longer follow-up a gradual and progressive flexion deformity was observed with a decrease in the arc of flexion in eight elbows, reaching > or = 90 degrees in all cases. The results of pectoralis major transfer deteriorate with time due to the development of a recalcitrant flexion deformity of the elbow. With bilateral involvement we now recommend that the procedure be undertaken on one side only to allow the hand to reach the mouth for feeding, while the opposite side remains in extension for perineal toilet.

Posterior sternoclavicular joint dislocation in children-role of spiral computed tomography

Traumatic posterior dislocation of the sternoclavicular joint is an uncommon injury in children. It is not normally well seen on plain films. We report 2 cases where spiral computed tomography with intravenous contrast confirmed the clinical suspicion of sternoclavicular joint dislocation and also allowed assessment of the adjacent mediastinum for possible complications. Emergency physicians should be aware that the use of spiral computed tomography is the procedure of choice in posterior sternoclavicular joint dislocation. This is particularly helpful in allowing multiplanar reconstruction to show complications arising in the mediastinum.

Evaluation of WOMAC 20, 50, 70 response criteria in patients treated with hylan G-F 20 for knee osteoarthritis

OBJECTIVE

A secondary analysis of a previously conducted one year randomised controlled trial to evaluate the capacity of responder criteria based on the WOMAC index to detect between treatment group differences.

METHODS

255 patients with knee osteoarthritis were randomised to "appropriate care with hylan G-F 20" (AC+H) or "appropriate care without hylan G-F 20" (AC). In the original analysis, two definitions of patient response from baseline to month 12 were used: (1) at least a 20% reduction in WOMAC pain score (WOMAC 20P); (2) at least a 20% reduction in WOMAC pain score and at least a 20% reduction in either WOMAC function or stiffness score (WOMAC 20PFS). For this analysis, a responder was identified using 50% and 70% minimum clinically important response levels to investigate how increasing response affects the ability to detect treatment group differences.

RESULTS

The hylan G-F 20 group had numerically more responders using all patient responder criteria. Increasing the response level from 20% to 50% detected similar differences between treatment groups (25% to 29%). Increasing the response level to 70% reduced the differences between treatment groups (11% to 12%) to a point where the differences were not significant after Bonferroni adjustment.

CONCLUSIONS

These results provide evidence for incorporating response levels (WOMAC 50) in clinical trials. While differences at the highest threshold (WOMAC 70) were not statistically detectable, an appropriately powered study may be capable of detecting differences even at this very high level of improvement.

Limb lengthening and correction of deformity in the lower limbs of children with osteogenesis imperfecta

We performed limb lengthening and correction of deformity of nine long bones of the lower limb in six children (mean age, 14.7 years) with osteogenesis imperfecta (OI). All had femoral lengthening and three also had ipsilateral tibial lengthening. Angular deformities were corrected simultaneously. Five limb segments were treated using a monolateral external fixator and four with the Ilizarov frame. In three children, lengthening was done over previously inserted femoral intramedullary rods.

The mean lengthening achieved was 6.26 cm (mean healing index, 33.25 days/cm). Significant complications included one deep infection, one fracture of the femur and one anterior angulation deformity of the tibia. The abnormal bone of OI tolerated the external fixators throughout the period of lengthening without any episodes of migration of wires or pins through the soft bone. The regenerate bone formed within the time which is normally expected in limb-lengthening procedures performed for other conditions.

We conclude that despite the abnormal bone characteristics, distraction osteogenesis to correct limb-length discrepancy and angular deformity can be performed safely in children with OI.

Increased adenosine in cerebrospinal fluid after severe traumatic brain injury in infants and children: association with severity of injury and excitotoxicity

OBJECTIVES

To measure adenosine concentration in the cerebrospinal fluid of infants and children after severe traumatic brain injury and to evaluate the contribution of patient age, Glasgow Coma Scale score, mechanism of injury, Glasgow Outcome Score, and time after injury to cerebrospinal fluid adenosine concentrations. To evaluate the relationship between cerebrospinal fluid adenosine and glutamate concentrations in this population.

DESIGN

Prospective survey.

SETTING

Pediatric intensive care unit in a university-based children's hospital.

PATIENTS

Twenty-seven critically ill infants and children who had severe traumatic brain injury (Glasgow Coma Scale < 8), who required placement of an intraventricular catheter and drainage of cerebrospinal fluid as part of their neurointensive care.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients ranged in age from 2 months to 14 yrs. Cerebrospinal fluid samples (n = 304) were collected from 27 patients during the first 7 days after traumatic brain injury. Control cerebrospinal fluid samples were obtained from lumbar puncture on 21 infants and children without traumatic brain injury or meningitis. Adenosine concentration was measured by using high-pressure liquid chromatography. Adenosine concentration was increased markedly in cerebrospinal fluid of children after traumatic brain injury vs. controls (p < .001). The increase in cerebrospinal fluid adenosine was independently associated with Glasgow Coma Scale < or = 4 vs. > 4 and time after injury (both p < .005). Cerebrospinal fluid adenosine concentration was not independently associated with either age (< or = 4 vs. > 4 yrs), mechanism of injury (abuse vs. other), or Glasgow Outcome Score (good/moderately disabled vs. severely disabled, vegetative, or dead). Of the 27 patients studied, 18 had cerebrospinal fluid glutamate concentration previously quantified by high-pressure liquid chromatography. There was a strong association between increases in cerebrospinal fluid adenosine and glutamate concentrations (p < .005) after injury.

CONCLUSIONS

Cerebrospinal fluid adenosine concentration is increased in a time- and severity-dependent manner in infants and children after severe head injury. The association between cerebrospinal fluid adenosine and glutamate concentrations may reflect an endogenous attempt at neuroprotection against excitotoxicity after severe traumatic brain injury.

The orthopaedic presentation of acute leukaemia in childhood

In children, acute leukaemia can mimic several orthopaedic pathologies and this variable presentation creates difficulties in achieving the correct diagnosis. Four consecutive cases are reported, all of which initially presented via the orthopaedic department, representing 17% of all new cases of leukaemia presenting to our hospital. This series is presented to highlight the need to place acute leukaemia on the list of differential diagnoses of acute joint pathology in children: the associated literature is reviewed.

Interstitial brain adenosine and xanthine increase during jugular venous oxygen desaturations in humans after traumatic brain injury

OBJECTIVE

Adenosine decreases the cerebral metabolic rate for oxygen and increases cerebral blood flow, and it may play an important role in cerebrometabolic and cerebrovascular responses to hypoperfusion after traumatic brain injury. Jugular venous oxygen saturation is monitored after traumatic brain injury to assess brain oxygen extraction, and desaturations may reflect secondary brain insults. We hypothesized that brain interstitial adenosine and related purine metabolites would be increased during jugular venous oxygen saturation desaturations (<50%) and determined associations between the purines, lactate, and glucose to assess the role of adenosine during secondary insults in humans.

DESIGN

Study of critically ill adults with severe traumatic brain injury.

SETTING

Adult neurointensive care unit.

PATIENTS

We prospectively defined periods of normal saturation and desaturation in six patients after severe traumatic brain injury.

INTERVENTIONS

During these periods, cerebral microdialysis samples of brain interstitial fluid were collected, and adenosine and purine metabolites were measured by high-pressure liquid chromatography.

MEASUREMENTS AND MAIN RESULTS

Adenosine increased 3.1-fold and xanthine increased 2.5-fold during desaturation periods (both p <.05 vs. normal saturation period, signed rank). Adenosine, xanthine, hypoxanthine, and cyclic-adenosine monophosphate correlated with lactate over both study periods (r(2) =.32,.14,.31,.07, and.26, respectively, all p <.05, Pearson product moment correlation).

CONCLUSION

The marked increases in interstitial brain adenosine that occur during jugular venous oxygen desaturations suggest that adenosine may play an important role during periods of secondary insults after traumatic brain injury. The correlation of these metabolites with lactate further suggests that adenosine is increased during periods of enhanced glycolytic metabolism.

Improvements following short term home based physical therapy are maintained at one year in people with moderate to severe rheumatoid arthritis

OBJECTIVE

We previously demonstrated the efficacy of a 6 week home based physical therapy (PT) intervention for people with moderate to severe rheumatoid arthritis (RA). This followup study determined if short term improvements were maintained to one year.

METHODS

Participants in the short term study were randomly assigned to receive a PT intervention (education, exercise, and pain relief modalities) delivered by physiotherapists with advanced rheumatology training (Weeks 0 to 6) or to a wait list control group. The control group received the intervention between Weeks 6 to 12. Outcome measures included the Stanford Arthritis Self-Efficacy Scale (SES), the Arthritis Community Research and Evaluation Unit Rheumatoid Arthritis Knowledge Questionnaire (KQ), and a visual analog scale for pain. Disease activity measures (tender joints, grip strength, and morning stiffness) were also included. MANOVA was used to compare within-subject scores at baseline and at 12 and 52 weeks. Paired t tests were used to determine if 12 week changes were maintained at 52 weeks.

RESULTS

Of the 127 protocol completers, 117 (92.1%) were available for the one year followup. For those measures that showed significant improvement in the randomized controlled trial (SES, KQ, morning stiffness), improvements at 12 weeks were maintained at 52 weeks (p > 0.010).

CONCLUSION

Subjects who participated in a short term home based PT intervention delivered by specially trained therapists reported improved outcomes following treatment, and these improvements were maintained at one year followup. Future studies need to explore the relative contributions of education, exercise, home based care, therapist training, and reinforcement strategies in improving longterm outcomes in RA.

Excitatory amino acid concentrations in ventricular cerebrospinal fluid after severe traumatic brain injury in infants and children: the role of child abuse

BACKGROUND

Excitotoxicity is an important mechanism in secondary neuronal injury after traumatic brain injury (TBI). Excitatory amino acids (EAAs) are increased in cerebrospinal fluid (CSF) in adults after TBI; however, studies in pediatric head trauma are lacking. We hypothesized that CSF glutamate, aspartate, and glycine would be increased after TBI in children and that these increases would be associated with age, child abuse, poor outcome, and cerebral ischemia.

METHODS

EAAs were measured in 66 CSF samples from 18 children after severe TBI. Control samples were obtained from 19 children who received lumbar punctures to rule out meningitis.

RESULTS

Peak and mean CSF glycine and peak CSF glutamate levels were increased versus control values. Subgroups of patients with TBI were compared by using univariate regression analysis. Massive increases in CSF glutamate were found in children <4 years old and in child abuse victims. Increased CSF glutamate and glycine were associated with poor outcome. A trend toward an association between high glutamate concentration and ischemic blood flow was observed.

CONCLUSIONS

CSF EAAs are increased in infants and children with severe TBI. Young age and child abuse were associated with extremely high CSF glutamate concentrations after TBI. A possible role for excitotoxicity after pediatric TBI is supported.

Hydroxychloroquine neuromyotoxicity

Hydroxychloroquine (HCQ) is commonly prescribed for treatment of inflammatory arthritis. The most frequently observed serious side effect is retinal toxicity; however, case reports have described HCQ induced neuromyotoxicity. We describe a case of HCQ neuromyotoxicity and a literature review from 1965 to September 1998 using Medline and Embase. Including our patient, there are 10 reported cases of HCQ neuromyotoxicity. Muscle biopsy consistently reveals curvilinear bodies and muscle fiber atrophy with vacuolar changes. Most cases manifest as insidious onset proximal myopathy that may be associated with peripheral neuropathy and cardiac myotoxicity. Resolution of symptoms is slow after discontinuation of therapy and may be incomplete. Possible predisposing factors include Caucasian race and concomitant renal failure. Patients treated with HCQ who develop a proximal myopathy, cardiomyopathy, or neuropathy, especially in the setting of worsening renal function, should be evaluated for possible HCQ neuromyotoxicity.

Leg lengthening for short stature in Turner's syndrome

We describe ten patients with Turner's syndrome (karyotype 45, XO) who had leg lengthening for short stature. A high incidence of postoperative complications was encountered and many patients required intramedullary fixation as a salvage procedure. We discuss the reasons for this and highlight the differences between our findings and those of a similar series recently reported. In view of the considerable difficulties encountered, we do not recommend leg lengthening in Turner's syndrome.

Increases in bcl-2 protein in cerebrospinal fluid and evidence for programmed cell death in infants and children after severe traumatic brain injury

OBJECTIVES

To determine whether bcl-2, a protein that inhibits apoptosis, would be increased in cerebrospinal fluid (CSF) in infants and children after traumatic brain injury (TBI) and to examine the association of bcl-2 concentration with clinical variables.

STUDY DESIGN

Bcl-2 was measured in CSF from 23 children (aged 2 months-16 years) with severe TBI and from 19 children without TBI or meningitis (control subjects) by enzyme-linked immunosorbent assay. CSF oligonucleosome concentration was also determined as a marker of DNA degradation. Brain samples from 2 patients undergoing emergent decompressive craniectomies were analyzed for bcl-2 with Western blot and for DNA fragmentation with TUNEL (terminal deoxynucleotidyl-transferase mediated biotin-dUTP nick-end labeling).

RESULTS

CSF bcl-2 concentrations were increased in patients with TBI versus control subjects (P =.01). Bcl-2 was increased in patients with TBI who survived versus those who died (P =.02). CSF oligonucleosome concentration tended to be increased after TBI (P =.07) and was not associated with bcl-2. Brain tissue samples showed an increase in bcl-2 in patients with TBI versus adult brain bank control samples and evidence of DNA fragmentation within cells with apoptotic morphology.

CONCLUSIONS

Bcl-2 may participate in the regulation of cell death after TBI in infants and children. The increase in bcl-2 seen in patients who survived is consistent with a protective role for this anti-apoptotic protein after TBI.

Interleukin-8 is increased in cerebrospinal fluid of children with severe head injury

OBJECTIVE

To determine interleukin (IL)-8 concentrations in ventricular cerebrospinal fluid from children with severe traumatic brain injury (TBI).

DESIGN

Prospective study.

SETTING

University children's hospital.

PATIENTS

Twenty-seven children hospitalized with severe TBI (Glasgow Coma Scale score < or =8), seven children with cerebrospinal fluid culture-positive bacterial meningitis, and twenty-four age-equivalent controls.

INTERVENTIONS

Placement of an intraventricular catheter and continuous drainage of cerebrospinal fluid.

MEASUREMENTS AND MAIN RESULTS

Median [range] cerebrospinal fluid IL-8 concentration in children with TBI (0-12 hrs) (4,452.5 [0-20,000] pg/mL) was markedly greater than that in controls (14.5 [0-250]) (p < .0001) and equivalent to concentrations in children with meningitis (5,300 [1,510-22,000] pg/mL) (p = .33). Cerebrospinal fluid IL-8 remained increased in children with severe TBI for up to 108 hrs after injury. Univariate logistic regression analysis demonstrated an association between cerebrospinal fluid IL-8 and child abuse (p = .07) and mortality (p = .01). Multivariate analysis demonstrated a strong, independent association between cerebrospinal fluid IL-8 and mortality (p = .01).

CONCLUSIONS

The data are consistent with an acute inflammatory component of TBI in children and suggest an association between cerebrospinal fluid IL-8 and outcome after TBI. IL-8 may represent a potential target for anti-inflammatory therapy.

Quinolinic acid in the cerebrospinal fluid of children after traumatic brain injury

OBJECTIVE

To measure quinolinic acid, a macrophage-derived neurotoxin, in the cerebrospinal fluid (CSF) of children after traumatic brain injury (TBI) and to correlate CSF quinolinic acid concentrations to clinically important variables.

DESIGN

A prospective, observational study.

SETTING

The pediatric intensive care unit in Children's Hospital of Pittsburgh, a tertiary care, university-based children's hospital.

PATIENTS

Seventeen critically ill children following severe TBI (Glasgow Coma Scale score <8) whose care required the placement of an intraventricular catheter for continuous drainage of CSF.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients ranged in age from 2 mos to 16 yrs (mean 6.0 yrs). CSF was collected immediately on placement of the ventricular catheter and daily thereafter. Quinolinic acid concentration was measured by gas chromatography/mass spectroscopy in 69 samples (4.0 +/- 0.4 [SEM] samples per patient). CSF quinolinic acid concentration progressively increased after injury (p = .034, multivariate analysis) and was increased in nonsurvivors vs. survivors (p = .002, multivariate analysis). CSF quinolinic acid concentration was not associated with age. Although overall CSF quinolinic acid concentration was not associated with shaken injury (p = .16, multivariate analysis), infants suffering with shaken infant syndrome had increased admission CSF quinolinic acid concentrations compared with children with accidental mechanisms of injury (p = .027, Mann-Whitney Rank Sum test).

CONCLUSIONS

A large and progressive increase in the macrophage-derived neurotoxin quinolinic acid is seen following severe TBI in children. The increase is strongly associated with increased mortality. Increased CSF quinolinic acid concentration on admission in children with shaken infant syndrome could reflect a delay in presentation to medical attention or age-related differences in quinolinic acid production. These findings raise the possibility that quinolinic acid may play a role in secondary injury after TBI in children and suggest an interaction between inflammatory and excitotoxic mechanisms of injury following TBI.

Surgical stabilisation of the lower limb in osteogenesis imperfecta using the Sheffield Telescopic Intramedullary Rod System

The Sheffield Expanding Intramedullary Rod System was developed after experiencing problems with existing rod systems in the management of osteogenesis imperfecta. Between 1986 and 1996 we treated 74 bones in the lower limb in 28 children at a median follow-up of 5.25 years. We have reviewed 24 children with a total of 60 rods. Before surgery, all children had had multiple fractures of the lower limb. At review eight patients had experienced no further fractures, but three had suffered five or more subsequently. Before initial stabilisation, 15 children had never walked, and only three (13%) used walking as their main means of mobility. After surgery, half of those who showed motor arrest were able to walk (p = 0.016). The number of patients able to walk, with or without aids, increased to 17 (p = 0.0001). We have experienced no evidence of epiphyseal damage after the procedure, and complication rates requiring rod exchange have been low (7%).

Postradiation morphea

We describe a 54-year-old woman who developed right breast morphea after radiotherapy following a lumpectomy for infiltrating lobular carcinoma. Skin biopsy confirmed the histological features of morphea. Treatment was initiated with both topical and intralesional steroid, resulting in marked improvement. Morphea following radiotherapy is an infrequently recognized phenomenon. However, when diagnosed early it may be effectively managed with local steroid treatment.

A case of Stevens-Johnson syndrome associated with oxaprozin therapy

We describe a case of Stevens-Johnson syndrome (SJS) associated with oxaprozin ("Daypro"), a relatively new nonsteroidal antiinflammatory drug (NSAID) of the propionic acid group. Our literature review shows that among the NSAID associated with SJS, oxicams have the highest risk. The risk is low for the propionic acid group. Indeed, the prevalence of their use was too low to permit an analysis of individual drugs. This is the first reported case of SJS associated with oxaprozin. Although the patient we describe survived the reaction, we think it is important to report such a potentially fatal reaction to a relatively newly available medication.

Soluble adhesion molecules in CSF are increased in children with severe head injury

Leukocyte-endothelial adhesion molecules, critical to the development of acute inflammation, are expressed in brain as part of the acute inflammatory response to traumatic brain injury (TBI). We measured the concentrations of the adhesion molecules P-selectin, ICAM-1, E-selectin, L-selectin, and VCAM-1 in ventricular cerebrospinal fluid (CSF) from children with severe TBI (Glasgow coma score < 8) and compared these findings with those from children with bacterial meningitis. P-selectin, an adhesion molecule associated with ischemia/reperfusion, was increased in children with TBI versus meningitis and control. Univariate and multivariate regression analyses demonstrated associations between CSF P-selectin and child abuse and age of < 4 years, and a significant, independent association between CSF intercellular adhesion molecule-1 (ICAM-1) and child abuse. These results are consistent with a specific acute inflammatory component to TBI in children. Future studies of secondary injury mechanisms and therapy after TBI should assess on the roles of P-selectin and ICAM-1 in injury and repair processes in brain after TBI.

Perthes disease affecting three female first-degree relatives

Perthes disease has an incidence of 1 in 4,750 live births (1 in 3,000 boys, but only 1 in 11,800 girls). Although there is evidence for a genetic predisposition to Perthes disease, more than two family members are rarely affected. We report the first recorded case of Perthes disease affecting three female first-degree relatives.

Quinolinic acid is increased in CSF and associated with mortality after traumatic brain injury in humans

We tested the hypothesis that quinolinic acid, a tryptophan-derived N-methyl-D-aspartate agonist produced by macrophages and microglia, would be increased in CSF after severe traumatic brain injury (TBI) in humans, and that this increase would be associated with outcome. We also sought to determine whether therapeutic hypothermia reduced CSF quinolinic acid after injury. Samples of CSF (n = 230) were collected from ventricular catheters in 39 patients (16 to 73 years old) during the first week after TBI, (Glasgow Coma Scale [GCS] < 8). As part of an ongoing study, patients were randomized within 6 hours after injury to either hypothermia (32 degrees C) or normothermia (37 degrees C) treatments for 24 hours. Otherwise, patients received standard neurointensive care. Quinolinic acid was measured by mass spectrometry. Univariate and multivariate analyses were used to compare CSF quinolinic acid concentrations with age, gender, GCS, time after injury, mortality, and treatment (hypothermia versus normothermia). Quinolinic acid concentration in CSF increased maximally to 463 +/- 128 nmol/L (mean +/- SEM) at 72 to 83 hours after TBI. Normal values for quinolinic acid concentration in CSF are less than 50 nmol/L. Quinolinic acid concentration was increased 5- to 50-fold in many patients. There was a powerful association between time after TBI and increased quinolinic acid (P < 0.00001), and quinolinic acid was higher in patients who died than in survivors (P = 0.003). Age, gender, GCS, and treatment (32 degrees C versus 37 degrees C) did not correlate with CSF quinolinic acid. These data reveal a large increase in quinolinic acid concentration in CSF after TBI in humans and raise the possibility that this macrophage-derived excitotoxin may contribute to secondary damage.