Formation and stability of impurity "snakes" in tokamak plasmas

New observations of the formation and dynamics of long-lived impurity-induced helical "snake" modes in tokamak plasmas have recently been carried out on Alcator C-Mod. The snakes form as an asymmetry in the impurity ion density that undergoes a seamless transition from a small helically displaced density to a large crescent-shaped helical structure inside q<1, with a regularly sawtoothing core. The observations show that the conditions for the formation and persistence of a snake cannot be explained by plasma pressure alone. Instead, many features arise naturally from nonlinear interactions in a 3D MHD model that separately evolves the plasma density and temperature.

Chemiluminescence of luminol catalyzed by electrochemically oxidized ferrocenes

Ferrocenes oxidized at an indium tin oxide-coated glass electrode catalyze the chemiluminescent reaction of luminol with hydrogen peroxide. The catalytic reaction has been studied with ferrocene derivatives in solution and covalently attached to ovalbumin adsorbed on the electrode. It is shown that chemiluminescence is initiated by electrochemical oxidation of the ferrocene derivative.

Preclinical development of CAT-354, an IL-13 neutralizing antibody, for the treatment of severe uncontrolled asthma

BACKGROUND AND PURPOSE

IL-13 is a pleiotropic Th2 cytokine considered likely to play a pivotal role in asthma. Here we describe the preclinical in vitro and in vivo characterization of CAT-354, an IL-13-neutralizing IgG4 monoclonal antibody (mAb), currently in clinical development.

EXPERIMENTAL APPROACH

In vitro the potency, specificity and species selectivity of CAT-354 was assayed in TF-1 cells, human umbilical vein endothelial cells and HDLM-2 cells. The ability of CAT-354 to modulate disease-relevant mechanisms was tested in human cells measuring bronchial smooth muscle calcium flux induced by histamine, eotaxin generation by normal lung fibroblasts, CD23 upregulation in peripheral blood mononuclear cells and IgE production by B cells. In vivo CAT-354 was tested on human IL-13-induced air pouch inflammation in mice, ovalbumin-sensitization and challenge in IL-13 humanized mice and antigen challenge in cynomolgus monkeys.

KEY RESULTS

CAT-354 has a 165 pM affinity for human IL-13 and functionally neutralized human, human variant associated with asthma and atopy (R130Q) and cynomolgus monkey, but not mouse, IL-13. CAT-354 did not neutralize human IL-4. In vitro CAT-354 functionally inhibited IL-13-induced eotaxin production, an analogue of smooth muscle airways hyperresponsiveness, CD23 upregulation and IgE production. In vivo in humanized mouse and cynomolgus monkey antigen challenge models CAT-354 inhibited airways hyperresponsiveness and bronchoalveolar lavage eosinophilia.

CONCLUSIONS AND IMPLICATIONS

CAT-354 is a potent and selective IL-13-neutralizing IgG4 mAb. The preclinical data presented here support the trialling of this mAb in patients with moderate to severe uncontrolled asthma.

Does the positive influence of an undergraduate rural placement persist into postgraduate years?

INTRODUCTION

Medical schools worldwide are playing a role in addressing the shortage of rural health practitioners. Selection of rural-origin students and long-term rural undergraduate placements have been shown to have a positive influence on a subsequent career choice of rural health. Evidence for the impact of short-term rural placements is less clear. In New Zealand, the Otago University Faculty of Medicine introduced a 7 week rural undergraduate placement at the Dunedin School Of Medicine, one of its three clinical schools, in 2000. A study of the first two annual cohorts showed a positive influence of the course on student attitudes to rural health and their intention to practise in a rural setting. The purpose of this study was to test whether or not these effects persisted into postgraduate years.

METHOD

The original study cohorts were posted a questionnaire (questions worded identically to the original survey) in 2009 (5th and 6th postgraduate years). Non-responders were followed up after 2 months. Graduates from the same year cohort at the two other Otago clinical schools (Christchurch and Wellington) were also surveyed. In addition to analysis by question, principal component analysis (PCA) identified 3 questions which represented the influence of the medical undergraduate program on students' attitudes towards rural general practice. This was used as an index of influence of the undergraduate curriculum.

RESULTS

There was a statistically significant difference among graduates from Dunedin and the other two schools in reporting a positive influence towards rural practice from the undergraduate course.When asked how the medical undergraduate program influenced their attitude towards a career in rural practice, 56% of respondents from Dunedin reported a positive influence compared with 24% from Christchurch and 15% Wellington. This effect was less strong than that obtained immediately after the rural placement where 70% of Dunedin based students reported a positive influence. The index value for positive effect on attitudes was significantly higher for respondents who studied at Dunedin than at Wellington (mean index value 0.552 for Dunedin, -0.374 for Wellington t=4.172, p=0.000) or Christchurch (mean index value -0.083 for Christchurch t=2.606, p=0.011). There was no significant difference between Christchurch and Wellington (t=1.420, p=0.160). There was no significant difference among schools in the proportion of graduates who had worked or intended to work in rural general practice at any point in their career (24% Dunedin, 31% Christchurch, 16% Wellington (Phi=0.160, p=0.178).

CONCLUSION

Most of the literature on the influence of rural undergraduate placements, especially short term placements, examines immediate changes. This study adds to the evidence by showing that positive effects from a rural undergraduate placement persist into the postgraduate years, although that in isolation is unlikely to result in a significant workforce effect. Further investigation is warranted into which features of the undergraduate placement result in an extended positive effect on student attitudes.

A comparison of the accuracy of film-screen mammography, full-field digital mammography, and digital breast tomosynthesis

AIM

To measure the change in diagnostic accuracy of conventional film-screen mammography and full-field digital mammography (FFDM) with the addition of digital breast tomosynthesis (DBT) in women recalled for assessment following routine screening.

MATERIALS AND METHODS

Ethics approval for the study was granted. Women recalled for assessment following routine screening with screen-film mammography were invited to participate. Participants underwent bilateral, two-view FFDM and two-view DBT. Readers scored each lesion separately for probability of malignancy on screen-film mammography, FFDM, and then DBT. The scores were compared with the presence or absence of malignancy based on the final histopathology outcome.

RESULTS

Seven hundred and thirty-eight women participated (93.2% recruitment rate). Following assessment 204 (26.8%) were diagnosed as malignant (147 invasive and 57 in-situ tumours), 286 (37.68%) as benign, and 269 (35.4%) as normal. The diagnostic accuracy was evaluated by using receiving operating characteristic (ROC) and measurement of area under the curve (AUC). The AUC values demonstrated a significant (p = 0.0001) improvement in the diagnostic accuracy with the addition of DBT combined with FFDM and film-screen mammography (AUC = 0.9671) when compared to FFDM plus film-screen mammography (AUC = 0.8949) and film-screen mammography alone (AUC = 0.7882). The effect was significantly greater for soft-tissue lesions [AUC was 0.9905 with the addition of DBT and AUC was 0.9201 for FFDM with film-screen mammography combined (p = 0.0001)] compared to microcalcification [with the addition of DBT (AUC = 0.7920) and for FFDM with film-screen mammography combined (AUC = 0.7843; p = 0.3182)].

CONCLUSION

The addition of DBT increases the accuracy of mammography compared to FFDM and film-screen mammography combined and film-screen mammography alone in the assessment of screen-detected soft-tissue mammographic abnormalities.

Measurement of the neutron radius of 208Pb through parity violation in electron scattering

We report the first measurement of the parity-violating asymmetry A(PV) in the elastic scattering of polarized electrons from 208Pb. A(PV) is sensitive to the radius of the neutron distribution (R(n)). The result A(PV)=0.656±0.060(stat)±0.014(syst) ppm corresponds to a difference between the radii of the neutron and proton distributions R(n)-R(p)=0.33(-0.18)(+0.16) fm and provides the first electroweak observation of the neutron skin which is expected in a heavy, neutron-rich nucleus.

New precision limit on the strange vector form factors of the proton

The parity-violating cross-section asymmetry in the elastic scattering of polarized electrons from unpolarized protons has been measured at a four-momentum transfer squared Q2 = 0.624  GeV2 and beam energy E(b) = 3.48  GeV to be A(PV) = -23.80 ± 0.78(stat) ± 0.36(syst) parts per million. This result is consistent with zero contribution of strange quarks to the combination of electric and magnetic form factors G(E)(s) + 0.517G(M)(s) = 0.003 ± 0.010(stat) ± 0.004(syst) ± 0.009(ff), where the third error is due to the limits of precision on the electromagnetic form factors and radiative corrections. With this measurement, the world data on strange contributions to nucleon form factors are seen to be consistent with zero and not more than a few percent of the proton form factors.

The clinical effectiveness and cost-effectiveness of different surveillance mammography regimens after the treatment for primary breast cancer: systematic reviews registry database analyses and economic evaluation

BACKGROUND

Following primary breast cancer treatment, the early detection of ipsilateral breast tumour recurrence (IBTR) or ipsilateral secondary cancer in the treated breast and detection of new primary cancers in the contralateral breast is beneficial for survival. Surveillance mammography is used to detect these cancers, but the optimal frequency of surveillance and the length of follow-up are unclear.

OBJECTIVES

To identify feasible management strategies for surveillance and follow-up of women after treatment for primary breast cancer in a UK setting, and to determine the effectiveness and cost-effectiveness of differing regimens.

METHODS

A survey of UK breast surgeons and radiologists to identify current surveillance mammography regimens and inform feasible alternatives; two discrete systematic reviews of evidence published from 1990 to mid 2009 to determine (i) the clinical effectiveness and cost-effectiveness of differing surveillance mammography regimens for patient health outcomes and (ii) the test performance of surveillance mammography in the detection of IBTR and metachronous contralateral breast cancer (MCBC); statistical analysis of individual patient data (West Midlands Cancer Intelligence Unit Breast Cancer Registry and Edinburgh data sets); and economic modelling using the systematic reviews results, existing data sets, and focused searches for specific data analysis to determine the effectiveness and cost-utility of differing surveillance regimens.

RESULTS

The majority of survey respondents initiate surveillance mammography 12 months after breast-conserving surgery (BCS) (87%) or mastectomy (79%). Annual surveillance mammography was most commonly reported for women after BCS or after mastectomy (72% and 53%, respectively). Most (74%) discharge women from surveillance mammography, most frequently 10 years after surgery. The majority (82%) discharge from clinical follow-up, most frequently at 5 years. Combining initiation, frequency and duration of surveillance mammography resulted in 54 differing surveillance regimens for women after BCS and 56 for women following mastectomy. The eight studies included in the clinical effectiveness systematic review suggest surveillance mammography offers a survival benefit compared with a surveillance regimen that does not include surveillance mammography. Nine studies were included in the test performance systematic review. For routine IBTR detection, surveillance mammography sensitivity ranged from 64% to 67% and specificity ranged from 85% to 97%. For magnetic resonance imaging (MRI), sensitivity ranged from 86% to 100% and specificity was 93%. For non-routine IBTR detection, sensitivity and specificity for surveillance mammography ranged from 50% to 83% and from 57% to 75%, respectively, and for MRI from 93% to 100% and from 88% to 96%, respectively. For routine MCBC detection, one study reported sensitivity of 67% and specificity of 50% for both surveillance mammography and MRI, although this was a highly select population. Data set analysis showed that IBTR has an adverse effect on survival. Furthermore, women experiencing a second tumour measuring >20 mm in diameter were at a significantly greater risk of death than those with no recurrence or those whose tumour was <10 mm in diameter. In the base-case analysis, the strategy with the highest net benefit, and most likely to be considered cost-effective, was surveillance mammography alone, provided every 12 months at a societal willingness to pay for a quality-adjusted life-year of either £20,000 or £30,000. The incremental cost-effectiveness ratio for surveillance mammography alone every 12 months compared with no surveillance was £4727.

LIMITATIONS

Few studies met the review inclusion criteria and none of the studies was a randomised controlled trial. The limited and variable nature of the data available precluded any quantitative analysis. There was no useable evidence contained in the Breast Cancer Registry database to assess the effectiveness of surveillance mammography directly. The results of the economic model should be considered exploratory and interpreted with caution given the paucity of data available to inform the economic model.

CONCLUSIONS

Surveillance is likely to improve survival and patients should gain maximum benefit through optimal use of resources, with those women with a greater likelihood of developing IBTR or MCBC being offered more comprehensive and more frequent surveillance. Further evidence is required to make a robust and informed judgement on the effectiveness of surveillance mammography and follow-up. The utility of national data sets could be improved and there is a need for high-quality, direct head-to-head studies comparing the diagnostic accuracy of tests used in the surveillance population.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Patient and public involvement

The involvement of patients and the public in the development of clinical research initiatives in the UK has been central and is increasing. Whilst initially developed in relation to cancer research and cancer care, this activity has now generalized to all of healthcare research particularly through organizations such as INVOLVE (www.invo.org.uk). Patients and Public Involvement (PPI) has been evaluated and shown to be established across the NHS in the UK. The National Institute for Health Research in England has made PPI central in its development. More recently evidence is accumulating that PPI has significant impact on the quality and delivery of clinical research in healthcare but more work on the evaluation of its impact is required.

Research-intensive cancer care in the NHS in the UK

In the late 1990 s, in response to poor national cancer survival figures, government monies were invested to enhance recruitment to clinical cancer research. Commencing with England in 2001 and then rolling out across all four countries, a network of clinical cancer research infrastructure was created, the new staff being linked to existing clinical care structures including multi-disciplinary teams. In parallel, a UK-wide co-ordination of cancer research funders driven by the 'virtual' National Cancer Research Institute, combined to create a 'whole-system approach' linking research funders, researchers and NHS clinicians all working to the same ends. Over the next 10 years, recruitment to clinical trials and other well-designed studies, increased 4-fold, reaching 17% of the incident cancer population, the highest national rate world-wide. The additional resources led to more studies opened, and more patients recruited across the country, for all types of cancers and irrespective of additional clinical research staff in some hospitals. In 2006, a co-ordinated decision was made to increasingly focus on randomized trials, leading to increased recruitment, without any fall-off in accrual to non-randomized and observational studies. The National Cancer Research Network has supported large successful trials which are changing clinical practice in many cancers.

The hepatitis B e antigen suppresses IL-1β-mediated NF-κB activation in hepatocytes

Previous clinical studies have demonstrated an association between the hepatitis B e antigen and Toll-like receptor (TLR) expression and signalling. Therefore, the aim of this study was to develop an in vitro assay to measure the effect of hepatitis B virus proteins, including the precore protein, on signalling mediated by members of the Toll-like/interleukin 1 (TIR) superfamily, by measuring NF-κB promoter activity. The basal level of NF-κB reporter activity was measured in three hepatocyte cell lines (Huh7, HepG2 and PH5CH8) and one kidney cell line (HEK293) using a luciferase assay. All cell lines were virtually refractory to stimulation with lipopolysaccharide; however, PH5CH8 cells had a robust activation of NF-κB in response to IL-1β stimulation, with ∼ 40-fold higher activation than the unstimulated control, a higher degree of activation than that observed in either Huh7 and HepG2, or HEK293 and HEK293-TLR2 cells. In PH5CH8 cells transfected with pCI expression constructs and stimulated with IL-1β, we showed that the precursor form of the precore protein, p25, inhibits NF-κB activation by up to 30% and the cytosolic form, p22, inhibits NF-κB activation by 70%. The core protein, p21, which shares significant homology with the precore protein except for a 10-amino acid extension at the N-terminus, had no effect on NF-κB activation. We hypothesize that the inhibition of IL-1β-mediated NF-κB activation by the precore protein may be a mechanism that allows the virus to persist, suggesting a role for the pool of precore protein that remains intracellular.

Mercury exposure and risks from dental amalgam in the US population, post-2000

Dental amalgam is 50% metallic mercury (Hg) by weight and Hg vapour continuously evolves from in-place dental amalgam, causing increased Hg content with increasing amalgam load in urine, faeces, exhaled breath, saliva, blood, and various organs and tissues including the kidney, pituitary gland, liver, and brain. The Hg content also increases with maternal amalgam load in amniotic fluid, placenta, cord blood, meconium, various foetal tissues including liver, kidney and brain, in colostrum and breast milk. Based on 2001 to 2004 population statistics, 181.1 million Americans carry a grand total of 1.46 billion restored teeth. Children as young as 26 months were recorded as having restored teeth. Past dental practice and recently available data indicate that the majority of these restorations are composed of dental amalgam. Employing recent US population-based statistics on body weight and the frequency of dentally restored tooth surfaces, and recent research on the incremental increase in urinary Hg concentration per amalgam-filled tooth surface, estimates of Hg exposure from amalgam fillings were determined for 5 age groups of the US population. Three specific exposure scenarios were considered, each scenario incrementally reducing the number of tooth surfaces assumed to be restored with amalgam. Based on the least conservative of the scenarios evaluated, it was estimated that some 67.2 million Americans would exceed the Hg dose associated with the reference exposure level (REL) of 0.3 μg/m(3) established by the US Environmental Protection Agency; and 122.3 million Americans would exceed the dose associated with the REL of 0.03 μg/m(3) established by the California Environmental Protection Agency. Exposure estimates are consistent with previous estimates presented by Health Canada in 1995, and amount to 0.2 to 0.4 μg/day per amalgam-filled tooth surface, or 0.5 to 1 μg/day/amalgam-filled tooth, depending on age and other factors.

Role of prophylactic uterine artery balloon catheters in the management of women with suspected placenta accreta

BACKGROUND

Placenta praevia and accreta are leading causes of major obstetric haemorrhage and peripartum hysterectomy. Detection is largely based on a high index of clinical suspicion, though the diagnostic accuracy of radiological imaging is improving. Interventional radiological techniques can reduce blood loss and the incidence of hysterectomy.

METHODS

We have reviewed our experience with bilateral prophylactic uterine artery balloon occlusion in the management of women with suspected placenta accreta. Thirteen women at high risk of major haemorrhage due to placenta praevia or suspected placenta accreta were retrospectively studied. Uterine artery balloons were placed prophylactically under neuraxial anaesthesia in the angiography suite followed by caesarean delivery in the obstetric operating theatre.

RESULTS

Intraoperative blood loss and transfusion requirements were low in our case series. There were no hysterectomies or admissions to the intensive care unit. Fetal bradycardia necessitating immediate caesarean delivery occurred in two women (15.4%).

CONCLUSION

In our case series in women with suspected placenta accreta, prophylactic use of uterine artery balloons was associated with a low requirement for blood transfusion but with possible increased risk of fetal compromise. Performing the interventional procedure at a different site from the operative room complicated management.

Functional relationships of phytoene synthase 1 alleles on chromosome 7A controlling flour colour variation in selected Australian wheat genotypes

Flour colour measured as a Commission Internationale de l'Eclairage (CIE) b* value is an important wheat quality attribute for a range of end-products, with genes and enzymes of the xanthophyll biosynthesis pathway providing potential sources of trait variation. In particular, the phytoene synthase 1 (Psy1) gene has been associated with quantitative trait loci (QTL) for flour b* colour variation. Several Psy1 alleles on chromosome 7A (Psy-A1) have been described, along with proposed mechanisms for influencing flour b* colour. This study sought to identify evolutionary relationships among known Psy-A1 alleles, to establish which Psy-A1 alleles are present in selected Australian wheat genotypes and establish their role in controlling variation for flour b* colour via QTL analysis. Phylogenetic analyses showed seven of eight known Psy-A1 alleles clustered with sequences from T. urartu, indicating the majority of alleles in Australian germplasm share a common evolutionary lineage. In this regard, Psy-A1a, Psy-A1c, Psy-A1e and Psy-A1p were common in Australian genotypes with flour b* colour ranging from white to yellow. In contrast Psy-A1s was found to be related to A. speltoides, indicating a possible A-B genome translocation during wheat polyploidisation. A new allele Psy-A1t (similar to Psy-A1s) was discovered in genotypes with yellow flour, with QTL analyses indicating Psy-A1t strongly influences flour b* colour in Australian germplasm. QTL LOD value maxima did not coincide with Psy-A1 gene locus in two of three populations and, therefore, Psy-A1a and Psy-A1p may not be involved in flour colour. Instead two other QTL were identified, one proximal and one distal to Psy-A1 in Australian wheat lines. Comparison of Psy-A1t and Psy-A1p predicted protein sequences suggests differences in putative sites for post-translational modification may influence enzyme activity and subsequent xanthophyll accumulation in the wheat endosperm. Psy-A1a and Psy-A1p were not involved in flour b* colour variation, indicating other genes control variation on chromosome 7A in some wheat genotypes.

Effects of Atenolol, Labetalol and Methyldopa on Endogenous Antioxidants In-vitro

The aim of this study was to investigate whether atenolol, labetalol and methyldopa, which are commonly used for the treatment of hypertension in pregnancy, can induce antioxidant activity.

Reactive oxygen species scavengers (plasma thiol, red cell lysate thiol, red cell superoxide dismutase, red cell membrane thiol and plasma glutathione) were measured after incubation of peripheral blood with atenolol and methyldopa, respectively.

The results showed that atenolol and labetalol could significantly raise the levels of plasma thiol and membrane thiol but had no effects on lysate thiol, superoxide dismutase and glutathione. The effects on membrane thiol occurred after 60 min incubation and on plasma thiol after 120 min incubation.

The data also suggest that atenolol and labetalol at lower concentrations tend to have additive effects on reactive oxygen species scavengers but at higher concentrations do not.

Methyldopa had no significant effect on any of the parameters measured.

These findings suggest that atenolol and labetalol are able to induce higher levels of antioxidant activity.

Digital infrared thermal imaging (DITI) of breast lesions: sensitivity and specificity of detection of primary breast cancers

AIM

To determine the sensitivity and specificity of digital infrared thermal imaging (DITI) in a series of women who underwent surgical excision or core biopsy of benign and malignant breast lesions presenting through the symptomatic clinic.

MATERIALS AND METHODS

DITI was evaluated in 63 symptomatic patients attending a one-stop diagnostic breast clinic.

RESULTS

Thermography had 90 true-negative, 16 false-positive, 15 false-negative and 5 true-positive results. The sensitivity was 25%, specificity 85%, positive predictive value 24%, and negative predictive value 86%.

CONCLUSION

Despite being non-invasive and painless, because of the low sensitivity for breast cancer, DITI is not indicated for the primary evaluation of symptomatic patients nor should it be used on a routine basis as a screening test for breast cancer.

Strengthening clinical cancer research in the United Kingdom

BACKGROUND

In 1999, 270,000 cases of cancer were registered in the United Kingdom, placing a large burden on the NHS. Cancer outcome data in 1999 suggested that UK survival rates were poorer than most other European countries. In the same year, a Department of Health review noted that clinical trials accrual was poor (<3.5% of incident cases) and hypothesised that increasing research activity might improve outcomes and reduce the variability of outcomes across England. Thus, the National Cancer Research Network (NCRN) was established to increase participation in cancer clinical research.

METHODS

The NCRN was established in 2001 to provide a robust infrastructure for cancer clinical research and improvements in patient care. Remit of NCRN is to coordinate, support and deliver cancer clinical research through the provision of research support staff across England. The NCRN works closely with similar networks in Scotland, Wales and the Northern Ireland. A key aim of NCRN is to improve the speed of research and this was also assessed by comparing the speed of study delivery of a subset of cancer studies opening before and after NCRN was established.

RESULTS

Patient recruitment increased through NCRN, with almost 32,000 (12% of annual incident cases) cancer patients being recruited each year. Study delivery has improved, with more studies meeting the recruitment target - 74% compared with 39% before NCRN was established.

CONCLUSION

The coordinated approach to cancer clinical research has demonstrated increased accrual, wide participation and successful trial delivery, which should lead to improved outcomes and care.

In Situ Simulation Training for Paediatric Cardiorespiratory Arrest: Initial Observations and Identification of Latent Errors

In response to a successful, although difficult resuscitation in one of our paediatric wards, we developed and implemented an educational program to improve the resuscitation skills, teamwork and safety climate in our multidisciplinary acute-care paediatric service. The program is ongoing and consists of didactic presentations, high-fidelity in situ simulation and facilitated debriefing to encourage reflective learning. The underlying goal, to provide this training to all staff over a two-year period, should be achieved by late 2011. In this preliminary report we describe teamwork difficulties that are commonly found during such training. These included inconsistent leadership behaviours, inadequate delegation of areas of responsibility, failure to communicate problems during the execution of technical tasks (such as difficulty opening the resuscitation trolley) and failure to challenge inadequate or inappropriate therapy (such as poor chest expansion during bag-mask ventilation). In addition, we unexpectedly discovered seven latent errors in our clinical environment during the first nine months of course delivery. The most disturbing of these was that participants repeatedly struggled to identify and overcome the locking-mechanism and tamper-proof device on a newly introduced resuscitation trolley.

Hydrogeophysical imaging of deposit heterogeneity and groundwater chemistry changes during DNAPL source zone bioremediation

Robust characterization and monitoring of dense nonaqueous phase liquid (DNAPL) source zones is essential for designing effective remediation strategies, and for assessing the efficacy of treatment. In this study high-resolution cross-hole electrical resistivity tomography (ERT) was evaluated as a means of monitoring a field-scale in-situ bioremediation experiment, in which emulsified vegetable oil (EVO) electron donor was injected into a trichloroethene source zone. Baseline ERT scans delineated the geometry of the interface between the contaminated alluvial aquifer and the underlying mudstone bedrock, and also the extent of drilling-induced physical heterogeneity. Time-lapse ERT images revealed major preferential flow pathways in the source and plume zones, which were corroborated by multiple lines of evidence, including geochemical monitoring and hydraulic testing using high density multilevel sampler arrays within the geophysical imaging planes. These pathways were shown to control the spatial distribution of the injected EVO, and a bicarbonate buffer introduced into the cell for pH control. Resistivity signatures were observed within the preferential flow pathways that were consistent with elevated chloride levels, providing tentative evidence from ERT of the biodegradation of chlorinated solvents.

Upper airway 2: Bronchiectasis, cystic fibrosis and sinusitis

The nose and paranasal sinuses are contiguous with the lower respiratory tract. Patients with bronchiectasis and cystic fibrosis commonly have sinonasal disease, which is thought to have the same aetiology and pathophysiology as the chronic lung disease. Despite this, the conditions are rarely considered together and there is very little literature on the treatment of sinonasal disease in bronchiectasis. In addition to being a common cause of comorbidity, there is evidence suggesting that sinonasal disease may directly influence the bronchial condition. This article reviews sinonasal disease in bronchiectasis and cystic fibrosis and addresses the possible interactions between the health and disease of the upper and lower airways.

Assessment of survival in a 2-year comparative study of lanthanum carbonate versus standard therapy

OBJECTIVE

Epidemiological data link elevated levels of serum phosphorus with increased mortality among patients with chronic kidney disease. Recent data also suggest improved survival with the use of dietary phosphate binders in patients on dialysis. However, few studies have comprehensively evaluated the survival benefit associated with different phosphate binders. A post-hoc survival analysis was undertaken of lanthanum carbonate (Fosrenol *) versus standard therapy.

RESEARCH DESIGN AND METHODS

Patients on dialysis enrolled in a phase 3, 2-year, comparative safety study were randomized 1:1 to lanthanum carbonate or standard therapy to treat serum phosphorus to a target of < or =5.9 mg/dL (1.90 mmol/L). Patients (N = 1354) were followed up for survival status during, or after completion of or discontinuation from the study.

MAIN OUTCOME MEASURES

Survival was measured by time from first dose of study medication to all-cause mortality or last contact.

RESULTS

The distribution of follow-up time was similar in the lanthanum carbonate and standard therapy groups (mean 23.7 versus 23.9 months [median 27.0 versus 26.0 months], respectively). Serum phosphorus levels were similar across treatment groups, as patients were treated to target. At follow-up, 19.9% (135/680) of patients treated with lanthanum carbonate had died versus 23.3% (157/674) on standard therapy (log-rank p = 0.18). In the subgroup of patients aged >65 years (n = 336), 27.0% (44/163) of lanthanum-carbonate-treated patients had died compared with 39.3% (68/173) on standard therapy (log-rank p = 0.04).

CONCLUSION

In these survival analyses, overall mortality was similar in the lanthanum carbonate and standard therapy groups, but results suggest that there was a survival benefit associated with lanthanum carbonate treatment for patients aged >65 years, who are likely to carry the greatest burden of vascular calcification. These results were similar to those observed in the Dialysis Clinical Outcomes Revisited study, a prospective trial of sevelamer hydrochloride designed to assess survival.