Childhood-Onset Lupus Nephritis in the Childhood Arthritis and Rheumatology Research Alliance Registry: Short-Term Kidney Status and Variation in Care

OBJECTIVE

The goal was to characterize short-term kidney status and describe variation in early care utilization in a multicenter cohort of patients with childhood-onset systemic lupus erythematosus (cSLE) and nephritis.

METHODS

We analyzed previously collected prospective data from North American patients with cSLE with kidney biopsy-proven nephritis enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry from March 2017 through December 2019. We determined the proportion of patients with abnormal kidney status at the most recent registry visit and applied generalized linear mixed models to identify associated factors. We also calculated frequency of medication use, both during induction and ever recorded.

RESULTS

We identified 222 patients with kidney biopsy-proven nephritis, with 64% class III/IV nephritis on initial biopsy. At the most recent registry visit at median (interquartile range) of 17 (8-29) months from initial kidney biopsy, 58 of 106 patients (55%) with available data had abnormal kidney status. This finding was associated with male sex (odds ratio [OR] 3.88, 95% confidence interval [95% CI] 1.21-12.46) and age at cSLE diagnosis (OR 1.23, 95% CI 1.01-1.49). Patients with class IV nephritis were more likely than class III to receive cyclophosphamide and rituximab during induction. There was substantial variation in mycophenolate, cyclophosphamide, and rituximab ever use patterns across rheumatology centers.

CONCLUSION

In this cohort with predominately class III/IV nephritis, male sex and older age at cSLE diagnosis were associated with abnormal short-term kidney status. We also observed substantial variation in contemporary medication use for pediatric lupus nephritis between pediatric rheumatology centers. Additional studies are needed to better understand the impact of this variation on long-term kidney outcomes.

Intraarticular steroids as DMARD-sparing agents for juvenile idiopathic arthritis flares: Analysis of the Childhood Arthritis and Rheumatology Research Alliance Registry

BACKGROUND

Children with juvenile idiopathic arthritis (JIA) who achieve a drug free remission often experience a flare of their disease requiring either intraarticular steroids (IAS) or systemic treatment with disease modifying anti-rheumatic drugs (DMARDs). IAS offer an opportunity to recapture disease control and avoid exposure to side effects from systemic immunosuppression. We examined a cohort of patients treated with IAS after drug free remission and report the probability of restarting systemic treatment within 12 months.

METHODS

We analyzed a cohort of patients from the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry who received IAS for a flare after a period of drug free remission. Historical factors and clinical characteristics and of the patients including data obtained at the time of treatment were analyzed.

RESULTS

We identified 46 patients who met the inclusion criteria. Of those with follow up data available 49% had restarted systemic treatment 6 months after IAS injection and 70% had restarted systemic treatment at 12 months. The proportion of patients with prior use of a biologic DMARD was the only factor that differed between patients who restarted systemic treatment those who did not, both at 6 months (79% vs 35%, p < 0.01) and 12 months (81% vs 33%, p < 0.05).

CONCLUSION

While IAS are an option for all patients who flare after drug free remission, it may not prevent the need to restart systemic treatment. Prior use of a biologic DMARD may predict lack of success for IAS. Those who previously received methotrexate only, on the other hand, are excellent candidates for IAS.

Social determinants of health influence disease activity and functional disability in Polyarticular Juvenile Idiopathic Arthritis

BACKGROUND

Social determinants of health (SDH) greatly influence outcomes during the first year of treatment in rheumatoid arthritis, a disease similar to polyarticular juvenile idiopathic arthritis (pJIA). We investigated the correlation of community poverty level and other SDH with the persistence of moderate to severe disease activity and functional disability over the first year of treatment in pJIA patients enrolled in the Childhood Arthritis and Rheumatology Research Alliance Registry.

METHODS

In this cohort study, unadjusted and adjusted generalized linear mixed effects models analyzed the effect of community poverty and other SDH on disease activity, using the clinical Juvenile Arthritis Disease Activity Score-10, and disability, using the Child Health Assessment Questionnaire, measured at baseline, 6, and 12 months.

RESULTS

One thousand six hundred eighty-four patients were identified. High community poverty (≥20% living below the federal poverty level) was associated with increased odds of functional disability (OR 1.82, 95% CI 1.28-2.60) but was not statistically significant after adjustment (aOR 1.23, 95% CI 0.81-1.86) and was not associated with increased disease activity. Non-white race/ethnicity was associated with higher disease activity (aOR 2.48, 95% CI: 1.41-4.36). Lower self-reported household income was associated with higher disease activity and persistent functional disability. Public insurance (aOR 1.56, 95% CI 1.06-2.29) and low family education (aOR 1.89, 95% CI 1.14-3.12) was associated with persistent functional disability.

CONCLUSION

High community poverty level was associated with persistent functional disability in unadjusted analysis but not with persistent moderate to high disease activity. Race/ethnicity and other SDH were associated with persistent disease activity and functional disability.

First Direct Detection Constraints on Planck-Scale Mass Dark Matter with Multiple-Scatter Signatures Using the DEAP-3600 Detector

Dark matter with Planck-scale mass (≃10^{19}  GeV/c^{2}) arises in well-motivated theories and could be produced by several cosmological mechanisms. A search for multiscatter signals from supermassive dark matter was performed with a blind analysis of data collected over a 813 d live time with DEAP-3600, a 3.3 t single-phase liquid argon-based detector at SNOLAB. No candidate signals were observed, leading to the first direct detection constraints on Planck-scale mass dark matter. Leading limits constrain dark matter masses between 8.3×10^{6} and 1.2×10^{19}  GeV/c^{2}, and ^{40}Ar-scattering cross sections between 1.0×10^{-23} and 2.4×10^{-18}  cm^{2}. These results are interpreted as constraints on composite dark matter models with two different nucleon-to-nuclear cross section scalings.

Pulse-shape discrimination against low-energy Ar-39 beta decays in liquid argon with 4.5 tonne-years of DEAP-3600 data

The DEAP-3600 detector searches for the scintillation signal from dark matter particles scattering on a 3.3 tonne liquid argon target. The largest background comes from 39 Ar beta decays and is suppressed using pulse-shape discrimination (PSD). We use two types of PSD estimator: the prompt-fraction, which considers the fraction of the scintillation signal in a narrow and a wide time window around the event peak, and the log-likelihood-ratio, which compares the observed photon arrival times to a signal and a background model. We furthermore use two algorithms to determine the number of photons detected at a given time: (1) simply dividing the charge of each PMT pulse by the mean single-photoelectron charge, and (2) a likelihood analysis that considers the probability to detect a certain number of photons at a given time, based on a model for the scintillation pulse shape and for afterpulsing in the light detectors. The prompt-fraction performs approximately as well as the log-likelihood-ratio PSD algorithm if the photon detection times are not biased by detector effects. We explain this result using a model for the information carried by scintillation photons as a function of the time when they are detected.

Enhancements in laser-generated hot-electron production via focusing cone targets at short pulse and high contrast

We report on the increase in the accelerated electron number and energy using compound parabolic concentrator (CPC) targets from a short-pulse (∼150 fs), high-intensity (>10^{18} W/cm^{2}), and high-contrast (∼10^{8}) laser-solid interaction. We report on experimental measurements using CPC targets where the hot-electron temperature is enhanced up to ∼9 times when compared to planar targets. The temperature measured from the CPC target is 〈T_{e}〉=4.4±1.3 MeV. Using hydrodynamic and particle in cell simulations, we identify the primary source of this temperature enhancement is the intensity increase caused by the CPC geometry that focuses the laser, reducing the focal spot and therefore increasing the intensity of the laser-solid interaction, which is also consistent with analytic expectations for the geometrical focusing.

Production of relativistic electrons at subrelativistic laser intensities

Relativistic electron temperatures were measured from kilojoule, subrelativistic laser-plasma interactions. Experiments show an order of magnitude higher temperatures than expected from a ponderomotive scaling, where temperatures of up to 2.2 MeV were generated using an intensity of 1×10^{18}W/cm^{2}. Two-dimensional particle-in-cell simulations suggest that electrons gain superponderomotive energies by stochastic acceleration as they sample a large area of rapidly changing laser phase. We demonstrate that such high temperatures are possible from subrelativistic intensities by using lasers with long pulse durations and large spatial scales.

Plasma Collision in a Gas Atmosphere

We present a study on the impact of a gas atmosphere on the collision of two counterpropagating plasmas (gold and carbon). Imaging optical Thomson scattering data of the plasma collision with and without helium in between have been obtained at the Omega laser facility. Without gas, we observed large scale mixing of colliding gold and carbon ions. Once ambient helium is added, the two plasmas remain separated. The difference in ionic temperature is consistent with a reduction of the maximum Mach number of the flow from M=7 to M=4. It results in a reduction of a factor ∼10 of the counterstreaming ion-ion mean free path. By adding a low-density ambient gas, it is possible to control the collision of two high-velocity counterstreaming plasma, transitioning from an interpenetrating regime to a regime in agreement with a hydrodynamic description.

The causal web of foetal alcohol spectrum disorders: a review and causal diagram

Foetal alcohol spectrum disorders (FASDs) are a leading cause of developmental disability. Prenatal alcohol use is the sole necessary cause of FASD, but it is not always sufficient. Multiple factors influence a child's susceptibility to FASD following prenatal alcohol exposure. Much of the FASD risk factor literature has been limited to discussions of association, rather than causation. While knowledge of predictor variables is important for identifying who is most at risk of FASD and for targeting interventions, causal knowledge is important for identifying effective mechanisms for prevention and intervention programmes. We conducted a systematic search and narrative synthesis of the evidence and used this to create a causal diagram (directed acyclic graph; DAG) to describe the causal pathways to FASD. Our results show that the aetiology of FASD is multifaceted and complex. FASD risk is determined by a range of lifestyle, sociodemographic, maternal, social, gestational, and genetic factors. The causal diagram that we present in this review provides a comprehensive summary of causal risk factors for FASD and can be used as a tool to inform data collection and statistical modelling strategies to minimise bias in future studies of FASD.

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

First Results from the DEAP-3600 Dark Matter Search with Argon at SNOLAB

This Letter reports the first results of a direct dark matter search with the DEAP-3600 single-phase liquid argon (LAr) detector. The experiment was performed 2 km underground at SNOLAB (Sudbury, Canada) utilizing a large target mass, with the LAr target contained in a spherical acrylic vessel of 3600 kg capacity. The LAr is viewed by an array of PMTs, which would register scintillation light produced by rare nuclear recoil signals induced by dark matter particle scattering. An analysis of 4.44 live days (fiducial exposure of 9.87 ton day) of data taken during the initial filling phase demonstrates the best electronic recoil rejection using pulse-shape discrimination in argon, with leakage <1.2×10^{-7} (90% C.L.) between 15 and 31  keV_{ee}. No candidate signal events are observed, which results in the leading limit on weakly interacting massive particle (WIMP)-nucleon spin-independent cross section on argon, <1.2×10^{-44}  cm^{2} for a 100  GeV/c^{2} WIMP mass (90% C.L.).

Development and validation of a physical model to investigate the biomechanics of infant head impact

Head injury in childhood is the single most common cause of death or permanent disability from injury. However, despite its frequency and significance, there is little understanding of the response of a child's head to injurious loading. This is a significant limitation when making early diagnoses, informing clinical and/or forensic management or injury prevention strategies. With respect to impact vulnerability, current understanding is predominantly based on a few post-mortem-human-surrogate (PMHS) experiments. Researchers, out of experimental necessity, typically derive acceleration data, currently an established measure for head impact vulnerability, by calculation. Impact force is divided by the head mass, to produce a "global approximation", a single-generalised head response acceleration value. A need exists for a new experimental methodology, which can provide specific regional or localised response data. A surrogate infant head, was created from high resolution computer tomography scans with properties closely matched to tissue response data and validated against PMHS head impact acceleration data. The skull was 3D-printed from co-polymer materials. The brain, represented as a lumped mass, comprised of an injected gelatin/water mix. High-Speed Digital-Image-Correlation optically measured linear and angular velocities and accelerations, strains and strain rates. The "global approximation" was challenged by comparison with regional and local acceleration data. During impacts, perpendicular (at 90°) to a surface, regional and local accelerations were up to three times greater than the concomitant "global" accelerations. Differential acceleration patterns were very sensitive to impact location. Suture and fontanelle regions demonstrated ten times more strain (103%/s) than bone, resulting in skull deformations similar in magnitude to those observed during child birth, but at much higher rates. Surprisingly, perpendicular impacts produced significantly greater rotational velocities and accelerations, which are closer to current published injury thresholds than expected, seemingly as a result of deformational changes to the complex skull geometry. The methodology has proven a significant new step in characterising and understanding infant head injury mechanics.

Ultrafast probing of magnetic field growth inside a laser-driven solenoid

We report on the detection of the time-dependent B-field amplitude and topology in a laser-driven solenoid. The B-field inferred from both proton deflectometry and Faraday rotation ramps up linearly in time reaching 210 ± 35 T at the end of a 0.75-ns laser drive with 1 TW at 351 nm. A lumped-element circuit model agrees well with the linear rise and suggests that the blow-off plasma screens the field between the plates leading to an increased plate capacitance that converts the laser-generated hot-electron current into a voltage source that drives current through the solenoid. ALE3D modeling shows that target disassembly and current diffusion may limit the B-field increase for longer laser drive. Scaling of these experimental results to a National Ignition Facility (NIF) hohlraum target size (∼0.2cm^{3}) indicates that it is possible to achieve several tens of Tesla.

Zika virus disease: a public health emergency

No abstract available.

Selecting children for head CT following head injury

OBJECTIVE

Indicators for head CT scan defined by the 2007 National Institute for Health and Care Excellence (NICE) guidelines were analysed to identify CT uptake, influential variables and yield.

DESIGN

Cross-sectional study.

SETTING

Hospital inpatient units: England, Wales, Northern Ireland and the Channel Islands.

PATIENTS

Children (<15 years) admitted to hospital for more than 4 h following a head injury (September 2009 to February 2010).

INTERVENTIONS

CT scan.

MAIN OUTCOME MEASURES

Number of children who had CT, extent to which NICE guidelines were followed and diagnostic yield.

RESULTS

Data on 5700 children were returned by 90% of eligible hospitals, 84% of whom were admitted to a general hospital. CT scans were performed on 30.4% of children (1734), with a higher diagnostic yield in infants (56.5% (144/255)) than children aged 1 to 14 years (26.5% (391/1476)). Overall, only 40.4% (984 of 2437 children) fulfilling at least one of the four NICE criteria for CT actually underwent one. These children were much less likely to receive CT if admitted to a general hospital than to a specialist centre (OR 0.52 (95% CI 0.45 to 0.59)); there was considerable variation between healthcare regions. When indicated, children >3 years were much more likely to have CT than those <3 years (OR 2.35 (95% CI 2.08 to 2.65)).

CONCLUSION

Compliance with guidelines and diagnostic yield was variable across age groups, the type of hospital and region where children were admitted. With this pattern of clinical practice the risks of both missing intracranial injury and overuse of CT are considerable.

Epidemiology of children with head injury: a national overview

BACKGROUND

The National Confidential Enquiry describes the epidemiology of children admitted to hospital with head injury.

METHOD

Children (<15 years old) who died or were admitted for >4 h with head injury were identified from 216 UK hospitals (1 September 2009 to 28 February 2010). Data were collected using standard proformas and entered on to a database. A descriptive analysis of the causal mechanisms, child demographics, neurological impairment, CT findings, and outcome at 72 h are provided.

RESULTS

Details of 5700 children, median age 4 years (range 0-14.9 years), were analysed; 1093 (19.2%) were <1 year old, 3500 (61.4%) were boys. There was a significant association of head injury with social deprivation 39.7/100 000 (95% CI 37.0 to 42.6) in the least deprived first quintile vs. 55.1 (95% CI 52.1 to 58.2) in the most deprived fifth quintile (p<0.01). Twenty-four children died (0.4%). Most children were admitted for one night or less; 4522 (79%) had a Glasgow Coma Scale score of 15 or were Alert (on AVPU (Alert, Voice, Pain, Unresponsive)). The most common causes of head injury were falls (3537 (62.1%); children <5 years), sports-related incidents (783 (13.7%); median age 12.4 years), or motor vehicle accidents (MVAs) (401 (7.1%); primary-school-aged children). CT scans were performed in 1734 (30.4%) children; 536 (30.9%) were abnormal (skull fracture and/or intracranial injury or abnormality): 269 (7.6%) were falls, 82 (10.5%) sports related and 100 (25%). A total of 357 (6.2%) children were referred to social care because of child protection concerns (median age 9 months (range 0-14.9 years)).

CONCLUSIONS

The data described highlight priorities for targeted age-specific head injury prevention and have the potential to provide a baseline to evaluate the effects of regional trauma networks (2012) and National Institute of Health and Care Excellence (NICE) head injury guidelines (2014), which were revised after the study was completed.

Abstract P1-13-16: Women commencing with anastrozole, letrozole or tamoxifen: The impact of comorbidity and demographics on initial choice

Background: Australian clinical guidelines recommend post-surgical endocrine therapy for all women with early, hormone-dependent breast cancer. Guidelines specify tamoxifen as first-line therapy for pre-menopausal women, and either tamoxifen or an aromatase inhibitor for post-menopausal women depending on their risk of recurrence which is based on tumour size and other prognostic indicators. Tamoxifen and the aromatase inhibitors have different side effect profiles and therefore comorbidity may also influence choice of therapy. We examined comorbidities, and the clinical and demographic characteristics of women initiated on different endocrine therapies for breast cancer in Australian practice.

Method: We identified the first dispensing of tamoxifen, anastrozole or letrozole for women diagnosed with invasive breast cancer in the 45 and Up Study between January 2003 and December 2009 (n = 1383). Unit-level pharmacy and medical service claims, hospital separations, and Cancer Registry records were linked to self-reported data to determine menopause status at diagnosis, tumour size, age, change in subsidy restrictions, and specified comorbidities which may affect choice of therapy (i.e. arthritis, endometrial cancer, osteoporosis, thromboembolism). Chi-square tests and multivariate generalised linear models were used to compare the characteristics of post-menopausal women initiated on different therapies.

Results: The majority of pre-menopausal women commenced therapy with tamoxifen (93%). Tamoxifen was the predominant therapy for post-menopausal women with tumours ≤1cm (54%), and anastrozole most common for those with larger tumours (49%). Post-menopausal women with osteoporosis were less likely to commence an aromatase inhibitor compared with tamoxifen (anastrozole RR = 0.7, 95%CI = 0.5-0.9, P = 0.019; letrozole RR = 0.6, 95%CI = 0.3-0.9, P = 0.033) and those with arthritis were 1.6-times more likely to commence with letrozole than anastrozole (95%CI = 1.6-2.3, P = 0.004). Tamoxifen was more likely to be initiated in women with large tumours who also had comorbid arthritis or were aged ≥75 years. Changes in subsidy restrictions were associated with significant increases in the proportion of post-menopausal women commencing an aromatase inhibitor rather than tamoxifen (anastrozole RR = 7.0; letrozole RR = 18.5).

Conclusions: The findings show clinical guidelines regarding endocrine therapies are being followed in Australian practice, particularly in relation to menopause status and tumour size as a recurrence risk factor. The findings also indicate there is interplay of comorbidity and choice of therapy for older women and those with arthritis or osteoporosis.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-13-16.

Rift valley Fever in Kruger national park: do buffalo play a role in the inter-epidemic circulation of virus?

Rift Valley fever (RVF) is a zoonotic mosquito-borne virus disease of livestock and wild ruminants that has been identified as a risk for international spread. Typically, the disease occurs in geographically limited outbreaks associated with high rainfall events and can cause massive losses of livestock. It is unclear how RVF virus persists during inter-epidemic periods but cryptic cycling of the virus in wildlife populations may play a role. We investigated the role that free-living African buffalo (Syncerus caffer caffer) might play in inter-epidemic circulation of the virus and looked for geographic, age and sex patterns of Rift Valley fever virus (RVFV) infection in African buffalo. Buffalo serum samples were collected (n = 1615) in Kruger National Park (KNP), South Africa, during a period of 1996-2007 and tested for antibodies to RVF. We found that older animals were more likely to be seropositive for anti-RVFV antibody than younger animals, but sex was not correlated with the likelihood of being anti-RVFV antibody positive. We also found geographic variation within KNP; herds in the south were more likely to have acquired anti-RVFV antibody than herds farther north - which could be driven by host or vector ecology. In all years of the study between 1996 and 2007, we found young buffalo (under 2 years of age) that were seropositive for anti-RVFV antibody, with prevalence ranging between 0 and 27% each year, indicating probable circulation. In addition, we also conducted a 4-year longitudinal study on 227 initially RVFV seronegative buffalo to look for evidence of seroconversion outside known RVF outbreaks within our study period (2008-2012). In the longitudinal study, we found five individuals that seroconverted from anti-RVFV antibody negative to anti-RVFV antibody positive, outside of any detected outbreak. Overall, our results provide evidence of long-term undetected circulation of RVFV in the buffalo population.

Ebola virus outbreaks in Africa: past and present

Ebola haemorrhagic fever (EHF) is a zoonosis affecting both human and non-human primates (NHP). Outbreaks in Africa occur mainly in the Congo and Nile basins. The first outbreaks of EHF occurred nearly simultaneously in 1976 in the Democratic Republic of the Congo (DRC, former Zaire) and Sudan with very high case fatality rates of 88% and 53%, respectively. The two outbreaks were caused by two distinct species of Ebola virus named Zaire ebolavirus (ZEBOV) and Sudan ebolavirus (SEBOV). The source of transmission remains unknown. After a long period of silence (1980-1993), EHF outbreaks in Africa caused by the two species erupted with increased frequency and new species were discovered, namely Côte d'Ivoire ebolavirus (CIEBOV) in 1994 in the Ivory Coast and Bundibugyo ebolavirus (BEBOV) in 2007 in Uganda. The re-emergence of EHF outbreaks in Gabon and Republic of the Congo were concomitant with an increase in mortality amongst gorillas and chimpanzees infected with ZEBOV. The human outbreaks were related to multiple, unrelated index cases who had contact with dead gorillas or chimpanzees. However, in areas where NHP were rare or absent, as in Kikwit (DRC) in 1995, Mweka (DRC) in 2007, Gulu (Uganda) in 2000 and Yambio (Sudan) in 2004, the hunting and eating of fruit bats may have resulted in the primary transmission of Ebola virus to humans. Human-to-human transmission is associated with direct contact with body fluids or tissues from an infected subject or contaminated objects. Despite several, often heroic field studies, the epidemiology and ecology of Ebola virus, including identification of its natural reservoir hosts, remains a formidable challenge for public health and scientific communities.

Mapping the ionization state of laser-irradiated Ar gas jets with multiwavelength monochromatic x-ray imaging

Two-dimensional monochromatic images of fast-electron stimulated Ar Kα and He-α x-ray self-emission have recorded a time-integrated map of the extent of Ar(≈6+) and Ar(16+) ions, respectively, within a high density (10(20) cm(-3) atomic density) Ar plasma. This plasma was produced by irradiating a 2 mm wide clustering Ar gas jet with an ultrahigh intensity (10(19) W/cm(2), 50 TW) Ti:sapphire laser operating at 800 nm. Spherically bent quartz crystals in the 200 (for Kα) and 201 (for He-α) planes were used as near-normal incidence reflective x-ray optics. We see that a large (830 μm long) region of plasma emits Kα primarily along the laser axis, while the He-α emission is confined to smaller hot spot (230 μm long) region that likely corresponds to the focal volume of the f/8 laser beam. X-ray spectra from a Bragg spectrometer operating in the von Hamos geometry indicate that the centroids of the Kα and He-α emission regions are separated by approximately 330 μm along the laser axis.

Influence of metals on the activity of a bradykinin-destroying enzyme kininase

Kininase prepared from guinea-pig serum was inhibited by cysteine at pH 7.4 to 7.6. A similar effect was found with edetic acid. The enzyme blocked by edetic acid was reactivated immediately by addition of Mn(++), Co(++) and Zn(++). These findings indicate that kininase is a metal-activated enzyme.

The incidence and aetiology of epistaxis in infants: a population-based study

OBJECTIVE

To estimate the incidence and describe the aetiology of epistaxis in infants.

DESIGN

Population-based study including a retrospective hospital admission database analysis and a postal questionnaire to clinicians.

SETTING

Wales, United Kingdom.

METHODS

Cases of epistaxis over a 6-year period (1999-2004) were identified from the Patient Episode Dataset for Wales (PEDW) and validated using clinical information to calculate the population-based incidence and ascertain the causes of epistaxis in infants in Wales.

RESULTS

36 confirmed cases were identified over the 6-year period giving an estimated annual incidence of epistaxis of 19.3 (95% CI 14.0 to 26.7) per 100,000 infants. The median age at admission was 12 weeks (interquartile range 4-33) (min 1 week, max 49 weeks). 23 of the infants had a recognised cause for their epistaxis (trauma (five), coagulation disorder (four), congenital anomaly (two), acute rhinitis or coryza (11), abusive smothering event (one)). No cause for the epistaxis was identified for 13 cases. Coagulation disorder was excluded in seven of these 13 infants but in the other six no attempt was made to exclude this disorder. Child abuse was suspected but excluded in four of the 13 cases.

CONCLUSION

Hospital admission for epistaxis is a rare event. In the majority of cases in this study a simple explanation was available and proven physical abuse was rare. A bleeding disorder should always be considered and, if additional evidence suggests physical abuse, this must be excluded.

Malplacement of endocardial pacemaker electrodes in the middle cardiac vein

Endocardial transvenous pacemaker electrodes have been implanted in 246 patients owing to symptomatic bradycardia. The electrode was malplaced in the middle cardiac vein in 12 patients. All the patients were on stable ventricular pacing at the time of implantation. The electrodes were still in function in six patients after 5-96 months (average 55). The electrode was replaced in three patients owing to the occurrence of exit block. Three patients died during the period under study. Right-sided bundle branch block (RBBB) configuration of paced QRS complexes was observed on the ECG when the electrode was malplaced in the middle cardiac vein. As RBBB only occurs with malplacement, the ECG can be employed to ensure correct positioning of the electrode.

High contrast Kr gas jet K alpha x-ray source for high energy density physics experiments

A high contrast 12.6 keV Kr K alpha source has been demonstrated on the petawatt-class Titan laser facility using strongly clustering Kr gas jet targets. The contrast ratio (K alpha to continuum) is 65, with a competitive ultrashort pulse laser to x-ray conversion efficiency of 10(-5). Filtered shadowgraphy indicates that the Kr K alpha and K beta x rays are emitted from a roughly 1x2 mm(2) emission volume, making this source suitable for area backlighting and scattering. Spectral calculations indicate a typical bulk electron temperature of 50-70 eV (i.e., mean ionization state 13-16), based on the observed ratio of K alpha to K beta. Kr gas jets provide a debris-free high energy K alpha source for time-resolved diagnosis of dense matter.

Amygdala and ventral anterior cingulate activation predicts treatment response to cognitive behaviour therapy for post-traumatic stress disorder

BACKGROUND

Although cognitive behaviour therapy (CBT) is the treatment of choice for post-traumatic stress disorder (PTSD), approximately half of patients do not respond to CBT. No studies have investigated the capacity for neural responses during fear processing to predict treatment response in PTSD.

METHOD

Functional magnetic resonance imaging (fMRI) responses of the brain were examined in individuals with PTSD (n=14). fMRI was examined in response to fearful and neutral facial expressions presented rapidly in a backwards masking paradigm adapted for a 1.5 T scanner. Patients then received eight sessions of CBT that comprised education, imaginal and in vivo exposure, and cognitive therapy. Treatment response was assessed 6 months after therapy completion.

RESULTS

Seven patients were treatment responders (defined as a reduction of 50% of pretreatment scores) and seven were non-responders. Poor improvement after treatment was associated with greater bilateral amygdala and ventral anterior cingulate activation in response to masked fearful faces.

CONCLUSIONS

Excessive fear responses in response to fear-eliciting stimuli may be a key factor in limiting responses to CBT for PTSD. This excessive amygdala response to fear may reflect difficulty in managing anxiety reactions elicited during CBT, and this factor may limit optimal response to therapy.

Absorption of short laser pulses on solid targets in the ultrarelativistic regime

We report the first direct measurements of total absorption of short laser pulses on solid targets in the ultrarelativistic regime. The data show an enhanced absorption at intensities above 10(20) W/cm(2), reaching 60% for near-normal incidence and 80%-90% for 45 degrees incidence. Two-dimensional particle-in-cell simulations demonstrate that such high absorption is consistent with both interaction with preplasma and hole boring by the intense laser pulse. A large redshift in the second harmonic indicates a surface recession velocity of 0.035c.

Fast-electron-relaxation measurement for laser-solid interaction at relativistic laser intensities

We present measurements of the fast-electron-relaxation time in short-pulse (0.5 ps) laser-solid interactions for laser intensities of 10(17), 10(18), and 10(19) Wcm2, using a picosecond time-resolved x-ray spectrometer and a time-integrated electron spectrometer. We find that the laser coupling to hot electrons increases as the laser intensity becomes relativistic, and that the thermalization of fast electrons occurs over time scales on the order of 10 ps at all laser intensities. The experimental data are analyzed using a combination of models that include Kalpha generation, collisional coupling, and plasma expansion.

Asthma onset prior to multiple sclerosis and the contribution of sibling exposure in early life

Higher sibling exposure is associated with a reduced risk of asthma and other T helper 2 (Th2)-type disorders, possibly through a beneficial effect of higher infection load. The effect on Th1 disorders such as multiple sclerosis (MS) is less clear. Here we examine the association between asthma and MS, taking into account early life sibling exposure. A population-based case-control study in Tasmania, Australia based on 136 cases of magnetic resonance imaging (MRI)-confirmed MS and 272 community controls, matched on sex and year of birth. Study measures include cumulative exposure to total, older or younger siblings by age 6 years, history of doctor-diagnosed asthma and serological IgG responses to herpes viruses. MS cases were more likely (P = 0.02) than controls to have asthma which began before age of onset of MS symptoms compared to the corresponding age for controls. The absence of younger sibling exposure by age 6 years potentiated (P = 0.04) the association between asthma and MS. Compared to those with younger sibling exposure and no asthma, the adjusted odds ratio for MS for those with asthma and no younger sibling exposure was 7.22 (95% CI: 2.52, 20.65). Early life sibling exposure was associated with altered IgG serological responses to Epstein-Barr virus (EBV) and herpes simplex virus 1 (HSV1) in adulthood. Reduced early life sibling exposure appeared to contribute to the excess of asthma among MS cases by the time of MS onset. MS development may reflect factors that relate to a general immuno-inflammatory up-regulation of immune activity as well as disease specific factors. The link between early life sibling exposure and the immune response to herpes group viral antigens is consistent with a protective role for early life infections.

Modification of the home environment for the reduction of injuries

BACKGROUND

Injury in the home is extremely common, accounting for around a third of all injuries. The majority of injuries of children under five and people aged 75 and over, occur at home. Multifactorial injury prevention interventions have been shown to reduce injuries in the home. However, few studies have focused specifically on the impact of physical adaptations to the home environment and the effectiveness of such interventions needs to be ascertained.

OBJECTIVES

To review the evidence for the effect on injuries of modification of the home environment with a primary focus on interventions to reduce physical hazards.

SEARCH STRATEGY

We searched The Cochrane Library, MEDLINE, EMBASE, National Research Register and other specialised databases. We also scanned conference proceedings and reference lists. In addition, we contacted experts and trialists in the field. The searches were not restricted by language or publication status. The searches were last updated in December 2004.

SELECTION CRITERIA

Randomised controlled trials.

DATA COLLECTION AND ANALYSIS

All abstracts were screened by two authors for relevance, outcome and design. Two authors independently assessed methodological quality and extracted data from each eligible study.

MAIN RESULTS

We found 18 published and one unpublished trials. Trials were not sufficiently similar to allow pooling of data by statistical analyses, so this review takes a narrative form. Studies were divided into three groups based on the primary population sample; children (five studies), older people (14 studies) and the general population/mixed age group (no studies). None of the studies focusing on children demonstrated a reduction in injuries that might have been due to environmental adaptation in the home; one study reported a reduction in injuries and in hazards but the two could not be linked. Of the 14 included studies in older people, none demonstrated a reduction in injuries due to hazard reduction, although two demonstrated a reduction in falls that could be due to hazard reduction.

AUTHORS' CONCLUSIONS

There is insufficient evidence to determine the effects of interventions to modify environmental home hazards. Further interventions to reduce hazards in the home should be evaluated by adequately designed randomised controlled trials measuring injury outcomes. Recruitment of large study samples to measure effect must be a major consideration for future trials.

A prospective study of the immediate and delayed adverse events following intravenous immunoglobulin infusions

AIM

To document the incidence of immediate and delayed adverse events (AE) following intravenous immunoglobulin (IVIG) infusion in children.

METHODS

Immediate and delayed adverse events were prospectively recorded for 345 infusions in 58 children receiving IVIG for immunodeficiency (n = 33) or immunomodulation (n = 25). For each infusion adverse events were documented during the infusion and by follow up interview 4-7 days later.

RESULTS

Immediate adverse events occurred in 10.3% and delayed adverse events in 41.4% of children treated during the study period. Three and a half per cent of the infusions were associated with immediate AE and 20.9% with delayed adverse events. Headache was the most common delayed AE, occurring in 24.1% of patients and 12.8% of infusions.

CONCLUSIONS

Delayed adverse events to IVIG infusions are common in children. They occur more frequently than immediate adverse events and are the cause of significant morbidity. Recognition of the high frequency of delayed adverse events is important in the care of children receiving IVIG therapy.

Assessment of bone strength at differentially-loaded skeletal regions in adolescent middle-distance runners

Bone adaptations to loading extend beyond mineral accrual to geometric markers of bone strength. Available technology and regional differences in cortical bone dictate how bone strength is reported. Examination of bone strength at two differentially-loaded skeletal sites using hip structure analysis (HSA) and bone strength index (BSI) is under-explored in adolescent sporting populations. The purpose of this study was to compare HSA at the femoral neck and BSI at the distal tibia in adolescent middle-distance runners and age- and gender-matched controls. Four groups of 20 adolescents aged 14-18 years were composed of male and female middle-distance runners, and male and female controls. Distal tibial BSI was calculated using data from dual energy X-ray absorptiometry (DXA) and magnetic resonance imaging (MRI). Calculations for femoral neck strength were acquired from DXA-derived HSA software. Female athletes displayed greater distal tibial BSI than controls t(38)=3.4, p=0.002, but femoral neck bone measures did not differ. In males, no group differences were found at either the distal tibia or femoral neck. In conclusion, exposure to similar high training loads may advantage female adolescent athletes more than male adolescent athletes compared with less active peers in bone strength at the distal tibia.

Microstructure of pharyngeal tooth enameloid in the parrotfish Scarus rivulatus (Pisces: Scaridae)

The microstructure of parrotfish pharyngeal teeth was examined using scanning electron microscopy to infer possible mechanical properties of the dentition with respect to their function. Parrotfish tooth enameloid is formed from fluorapatite crystals grouped into bundles. In the upper and lower pharyngeal jaw, the majority of the crystal bundles are orientated either perpendicularly or vertically to the enameloid surface. The only exception is in the trailing apical enameloid in which the majority of bundles are orientated perpendicularly or horizontally to the trailing surface. A distinct transition occurs through the middle of the apex between the leading and trailing enameloid in teeth of the lower pharyngeal jaw. This transition appears less distinct in the teeth of the upper pharyngeal jaw. Enameloid microstructure indicates that shear forces predominate at the apex of the teeth. In the remainder of the enameloid, the microstructure indicates that wear is predominant, and the shear forces are of less importance.