Reading tea leaves worldwide: Decoupled drivers of initial litter decomposition mass-loss rate and stabilization

The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large-scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass-loss rates and stabilization factors of plant-derived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easy-to-degrade components accumulate during early-stage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial mass-loss rates and stabilization, notably in colder locations. Using TBI improved mass-loss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during early-stage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models.

Leaf decomposition and flammability are largely decoupled across species in a tropical swamp forest despite sharing some predictive leaf functional traits

Decomposition and fire are major carbon pathways in many ecosystems, yet potential linkages between these processes are poorly understood. We test whether variability in decomposability and flammability across species are related to each other and to key plant functional traits in tropical swamp forests, where habitat degradation is elevating decomposition and fire regimes. Using senesced and fresh leaves of 22 swamp tree species in Singapore, we conducted an in situ decomposition experiment and a laboratory flammability experiment. We analysed 16 leaf physical and biochemical traits as predictors of decomposability and components of flammability: combustibility, ignitability and sustainability. Decomposability and flammability were largely decoupled across species, despite some shared predictive traits such as specific leaf area (SLA). Physical traits predicted that thicker leaves with a smaller SLA and volume decomposed faster, while various cation concentrations predicted flammability components, particularly ignitability. We show that flammability and decomposability of swamp forest leaves are decoupled because flammability is mostly driven by biochemical traits, while decomposition is driven by physical traits. Our approach identifies species that are slow to decompose and burn (e.g. Calophyllum tetrapterum and Xanthophyllum flavescens), which could be planted to mitigate carbon losses in tropical swamp reforestation.

Women's Understanding of Windows of Susceptibility and the Role of the Environment in Breast Cancer Risk

Emerging evidence suggests women who are exposed to harmful environmental exposures, especially during certain critical periods across the lifespan, may increase their breast cancer risk. Such windows of susceptibility (WoS) occur throughout a woman's lifetime, during which she is especially vulnerable to the effects of harmful environmental exposures. This interaction makes the reduction of harmful environmental toxicants during those time periods a priority for community health promotion. Communicating about environmental exposures and their impact on women's health requires an assessment of sense-making around, and understanding of, the link between breast cancer and the environment. To that end, focus groups were conducted to assess the themes that emerge when women make sense of (a) their own breast cancer risk, (b) the environment-cancer connection, and (c) WoS. Results provide insight into how women understand these issues which can inform messaging strategies focused on reducing harmful environmental exposures. Implications are discussed within the context of communication efforts tailored to educate women, particularly mothers with daughters in the prepubertal and pubertal WoS who are particularly vulnerable to harmful environmental exposures.

The road to recovery: a synthesis of outcomes from ecosystem restoration in tropical and sub-tropical Asian forests

Current policy is driving renewed impetus to restore forests to return ecological function, protect species, sequester carbon and secure livelihoods. Here we assess the contribution of tree planting to ecosystem restoration in tropical and sub-tropical Asia; we synthesize evidence on mortality and growth of planted trees at 176 sites and assess structural and biodiversity recovery of co-located actively restored and naturally regenerating forest plots. Mean mortality of planted trees was 18% 1 year after planting, increasing to 44% after 5 years. Mortality varied strongly by site and was typically ca 20% higher in open areas than degraded forest, with height at planting positively affecting survival. Size-standardized growth rates were negatively related to species-level wood density in degraded forest and plantations enrichment settings. Based on community-level data from 11 landscapes, active restoration resulted in faster accumulation of tree basal area and structural properties were closer to old-growth reference sites, relative to natural regeneration, but tree species richness did not differ. High variability in outcomes across sites indicates that planting for restoration is potentially rewarding but risky and context-dependent. Restoration projects must prepare for and manage commonly occurring challenges and align with efforts to protect and reconnect remaining forest areas. The abstract of this article is available in Bahasa Indonesia in the electronic supplementary material. This article is part of the theme issue 'Understanding forest landscape restoration: reinforcing scientific foundations for the UN Decade on Ecosystem Restoration'.

Global maps of soil temperature

Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km2 resolution for 0-5 and 5-15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1-km2 pixels (summarized from 8519 unique temperature sensors) across all the world's major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (-0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications.

SoilTemp: A global database of near-surface temperature

Current analyses and predictions of spatially explicit patterns and processes in ecology most often rely on climate data interpolated from standardized weather stations. This interpolated climate data represents long-term average thermal conditions at coarse spatial resolutions only. Hence, many climate-forcing factors that operate at fine spatiotemporal resolutions are overlooked. This is particularly important in relation to effects of observation height (e.g. vegetation, snow and soil characteristics) and in habitats varying in their exposure to radiation, moisture and wind (e.g. topography, radiative forcing or cold-air pooling). Since organisms living close to the ground relate more strongly to these microclimatic conditions than to free-air temperatures, microclimatic ground and near-surface data are needed to provide realistic forecasts of the fate of such organisms under anthropogenic climate change, as well as of the functioning of the ecosystems they live in. To fill this critical gap, we highlight a call for temperature time series submissions to SoilTemp, a geospatial database initiative compiling soil and near-surface temperature data from all over the world. Currently, this database contains time series from 7,538 temperature sensors from 51 countries across all key biomes. The database will pave the way toward an improved global understanding of microclimate and bridge the gap between the available climate data and the climate at fine spatiotemporal resolutions relevant to most organisms and ecosystem processes.

P3608Long-term mortality and mode of death among patients with type 1 and 2 myocardial infarction

Background

Few studies address long-term outcomes among patients with type 2 myocardial infarction (T2MI). It has been suggested that patients with T2MI with concomitant stable ischemic heart disease are at higher-risk.

Purpose

Our goals were two-fold. First, to examine 5-year mortality rates and mode of death among patients with type 1 (T1MI) and T2MI. Second, to evaluate the prognostic impact of coronary artery disease (CAD) on long-term outcomes among patients with T2MI.

Methods

Post-hoc analysis of UTROPIA (NCT02060760), a prospective, observational cohort study involving 1,640 consecutive emergency department patients with serial cardiac troponin (cTn) I measurements obtained on clinical indication. 5-year death rates, including mode of death, were examined among patients with T1MI and T2MI. CAD was defined as the presence of any of the following: history of CAD, prior MI, prior coronary artery bypass graft surgery, prior percutaneous coronary intervention, prior coronary stenting, or documented CAD (≥50%) on index admission angiography.

Results

Among 1640 patients, acute MI was diagnosed in 217 patients, including 77 (4.7%) classified as T1MI and 140 (8.5%) as T2MI. At 5-years, 23% (n=18) of patients with T1MI had died, with 61% (n=11) categorized as cardiac deaths. For T2MI, 37% (n=52) had died at 5-years, with 36% (n=19) categorized as cardiac deaths. Patients with T2MI had a higher 5-year mortality than T1MI (37% vs 23%, p=0.038) (Figure, Panel A), with T2MI more likely than T1MI to die from non-cardiac causes (64% vs. 39%, p=0.04). CAD was present in 22% (n=31) of patients with T2MI and associated with worse outcomes (p=0.0496) (Figure, Panel B).

Conclusion

T2MI has worse long term outcomes than T1MI. The predominant mode of death among patients with T2MI is non-cardiac. However, approximately 40% of deaths are cardiac. Further, we confirm the presence of CAD identifies a subset of patients with T2MI at high-risk.

Acknowledgement/Funding

Abbott Diagnostics and Hennepin Healthcare Research Institute (formerly MMRF)

P851Incidence and prognostic impact of acute infection among patients with type 1 and 2 myocardial infarction

Background

The incidence and impact of acute infection among patients with type 1 (T1MI) and 2 myocardial infarction (T2MI) is not well known. Inflammation and increased procoagulant activity can lead to T1MI, whereas cytokine release can cause hemodynamic alterations affecting myocardial oxygen consumption and contribute to T2MI.

Purpose

Determine the incidence and prognostic impact of acute infection among patients with T1MI and T2MI.

Methods

Post-hoc analysis of UTROPIA (NCT02060760), a prospective, observational cohort study involving 1,640 consecutive emergency department patients with serial cardiac troponin (cTn) I measurements obtained on clinical indication. The incidence of acute infection, antibiotic use, and/or laboratory evidence of infection were examined among patients with T1MI and T2MI. 5-year cumulative survival curves were plotted using the Kaplan-Meier method, frequencies were compared via Chi-Square, and a multivariate cox-proportional hazards model was used to assess the impact of infection on mortality.

Results

Among 217 patients with acute MI (T1MI, n=77 and T2MI, n=140), acute infection occurred in 63 (29%) of patients. Acute infection was more common in patients with T2MI than T1MI (35% vs. 18%, p=0.009). The predominant source of infection was pneumonia (59%), followed by urinary tract infections (11%). Patients with T2MI were also more likely than T1MI to have sepsis (11% vs. 1%, p=0.012), bacteremia (30% vs. 18%, p=0.057), and antibiotic use (35% vs. 17%, p=0.005). At 5-years, patients with acute MI and acute infection had a higher mortality rate than patients without infection (49% vs. 25%, p=0.0006) (Figure). Among the 31 deaths in MI patients with acute infection, most deaths were non-cardiac (65%) and occurred in those with T2MI (77%). Following adjustment for age, sex, and comorbidities in a Cox proportional hazards model, acute infection was an independent predictor of death (hazard ratio: 2.2, 95% CI: 1.3–3.5, p=0.0016).

Conclusion

Acute infection occurs in almost a third of patients that are diagnosed with acute MI during the index hospitalization. Most infections are due to pneumonia and occur most often in patients classified as having T2MI. Acute infection is an independent risk factor for 5-year mortality, with nearly half of all patients with acute MI in whom concomitant acute infection is present during the index hospitalization dead at 5-years. Most deaths are non-cardiac and the vast majority occur in patients with T2MI.

Acknowledgement/Funding

Abbott Diagnostics and Hennepin Healthcare Research Institute (formerly MMRF)e

Adult minimal-change disease: observational data from a UK centre on patient characteristics, therapies, and outcomes

Background

Minimal change disease (MCD) is a common cause of the nephrotic syndrome in adults with limited evidence on its treatment and prognosis. We examined the presenting characteristics, treatments, and outcomes of adult patients with MCD in our centre.

Methods

This was an observational cohort study using retrospectively-collected data. All patients who had a renal biopsy reported as MCD between 1996 and 2012 were included, and data were collected at baseline and during follow-up. Statistical analysis included Cox-regression analysis to examine which factors were associated with risk of relapse.

Results

Seventy-eight patients were included, and had a median age of 36 years, and were 60% male and 73% white. Median follow-up time was 72 months. 37% were in AKI at presentation, which was significantly associated with a lower serum albumin and older age. Although 10% were steroid-resistant, 98% achieved remission at a median time of 5 weeks. 61% relapsed, at a median time of 11 months, and patients had a median number of 2 relapses during follow-up. A higher eGFR was associated with an increased risk of relapse (hazard ratio 1.18 [1.03–1.36] per 10 mL/min increase in eGFR), and females were significantly more likely than males to have an early relapse. Nearly half of the cohort required an additional immunosuppressive agent on top of glucocorticoids, the most commonly used being calcineurin inhibitors. Five patients subsequently developed FSGS: these patients had a lower baseline creatinine, a higher serum albumin, a longer time to remission, and were more likely to be steroid-resistant. Follow-up renal function was generally preserved, but follow-up creatinine was higher in those who had presented with AKI, and in those who had been commenced on a RAS inhibitor after biopsy. Infection requiring admission, diabetes mellitus and venous thromboembolism developed in 14%, 12%, and 12% of patients respectively.

Conclusions

Nearly all adults with MCD achieve remission, but relapses and disease- and therapy-related complications are common. In our cohort, eGFR and gender were associated with risk of relapse, and these previously undescribed associations could be explored further in future work.

The efficacy of rituximab in adult frequently relapsing minimal change disease

Background

Corticosteroids are the basis of treatment for nephrotic syndrome due to minimal change disease (MCD), but 25% of patients have frequently relapsing nephrotic syndrome (FRNS) and 30% become steroid dependent. Prolonged use of conventional immunosuppressants causes significant toxicity. Rituximab (RTX) is now included in guidelines for childhood MCD. Evidence for use in adult MCD is limited. We describe a single-centre experience of RTX use in adult MCD.

Methods

Outcomes of all adult MCD patients treated with RTX for FRNS between 2008 and 2015 were retrospectively analysed.

Results

Thirteen patients received RTX; 11/13 had childhood-onset MCD. All had FRNS and 10 were steroid dependent. Eleven patients experienced one or more major treatment side effect from conventional therapy. At the time of RTX treatment, six patients were relapsing. All entered remission after RTX. The median length of follow-up after the first RTX treatment was 20 months (range 6–85). After RTX, the rate of relapse was reduced from 4 to 0.4/year (Wilcoxon signed rank P ≤ 0.05). Seven patients relapsed after RTX after a median of 10 months (range 1–11). All seven relapsing patients were successfully re-treated with RTX and none developed RTX-resistant nephrosis. The median number of courses of RTX per patient was 1 (range 1–5). The number of additional immunosuppressants, steroid dependency and antihypertensive agents were also reduced. At the last follow-up, two patients remained on low-dose steroids. No RTX-related adverse events were observed.

Conclusion

RTX is safe and effective in adults with FRNS due to MCD. The median rate of relapse is significantly reduced following RTX treatment and additional immunosuppressant exposure is minimized.

Epidemiology and risk factors for nosocomial bloodstream infections in solid organ transplants over a 10-year period

BACKGROUND

Bloodstream infections (BSIs) are a leading cause of morbidity and mortality in solid organ transplantation (SOT). We sought to determine the types of nosocomial BSIs and risk factors for them in SOT.

METHODS

Prospectively collected databases of all SOT and nosocomial BSIs occurring at our institution for a 10-year period were reviewed.

RESULTS

From 2003-2012, we observed 157 nosocomial BSI episodes in 2257 SOTs, the majority of which were caused by staphylococci and enterococci (67.5%). The most common sources of BSI were central line, organ space, respiratory, and gastrointestinal. Kidney transplant patients had the lowest risk of acquiring a BSI compared with other SOT types. Lung transplant patients were at increased risk of methicillin-resistant Staphylococcus aureus BSI and heart transplant patients were at increased risk of a Candida albicans BSI, when compared to other organ transplant types. When coagulase-negative Staphylococcus (CoNS) or C. albicans was isolated, the central line was most often the source. The implementation of central-line bundles during the study period correlated temporally with a decreased rate of CoNS BSI. Over the 10-year period, vancomycin-resistant enterococci became the most common enterococcal BSI. Donor-positive cytomegalovirus status was associated with an increased risk of BSI, when compared to donor-negative patients.

CONCLUSIONS

This study demonstrates the common sources, risk factors, and causative organisms of BSI, which can guide empiric antibiotic choices, and highlights areas where preventative interventions could be targeted to prevent nosocomial BSI in SOT.

Combination of herbivore removal and nitrogen deposition increases upland carbon storage

Ecosystem carbon (C) accrual and storage can be enhanced by removing large herbivores as well as by the fertilizing effect of atmospheric nitrogen (N) deposition. These drivers are unlikely to operate independently, yet their combined effect on aboveground and belowground C storage remains largely unexplored. We sampled inside and outside 19 upland grazing exclosures, established for up to 80 years, across an N deposition gradient (5-24 kg N ha(-1) yr(-1) ) and found that herbivore removal increased aboveground plant C stocks, particularly in moss, shrubs and litter. Soil C storage increased with atmospheric N deposition, and this was moderated by the presence or absence of herbivores. In exclosures receiving above 11 kg N ha(-1) year(-1) , herbivore removal resulted in increased soil C stocks. This effect was typically greater for exclosures dominated by dwarf shrubs (Calluna vulgaris) than by grasses (Molinia caerulea). The same pattern was observed for ecosystem C storage. We used our data to predict C storage for a scenario of removing all large herbivores from UK heathlands. Predictions were made considering herbivore removal only (ignoring N deposition) and the combined effects of herbivore removal and current N deposition rates. Predictions including N deposition resulted in a smaller increase in UK heathland C storage than predictions using herbivore removal only. This finding was driven by the fact that the majority of UK heathlands receive low N deposition rates at which herbivore removal has little effect on C storage. Our findings demonstrate the crucial link between herbivory by large mammals and atmospheric N deposition, and this interaction needs to be considered in models of biogeochemical cycling.

Root traits predict decomposition across a landscape-scale grazing experiment

Root litter is the dominant soil carbon and nutrient input in many ecosystems, yet few studies have considered how root decomposition is regulated at the landscape scale and how this is mediated by land-use management practices. Large herbivores can potentially influence below-ground decomposition through changes in soil microclimate (temperature and moisture) and changes in plant species composition (root traits). To investigate such herbivore-induced changes, we quantified annual root decomposition of upland grassland species in situ across a landscape-scale livestock grazing experiment, in a common-garden experiment and in laboratory microcosms evaluating the influence of key root traits on decomposition. Livestock grazing increased soil temperatures, but this did not affect root decomposition. Grazing had no effect on soil moisture, but wetter soils retarded root decomposition. Species-specific decomposition rates were similar across all grazing treatments, and species differences were maintained in the common-garden experiment, suggesting an overriding importance of litter type. Supporting this, in microcosms, roots with lower specific root area (m(2) g(-1)) or those with higher phosphorus concentrations decomposed faster. Our results suggest that large herbivores alter below-ground carbon and nitrogen dynamics more through their effects on plant species composition and associated root traits than through effects on the soil microclimate.

Parasitic plant litter input: a novel indirect mechanism influencing plant community structure

Parasitic plants have major impacts on plant community structure through their direct negative influence on host productivity and competitive ability. However, the possibility that these parasites may also have indirect impacts on community structure (via the mechanism of nutrient-rich litter input) while long hypothesized, has remained unsupported until now. Using the hemiparasite Rhinanthus minor, we established experimental grassland mesocosms to quantify the impacts of Rhinanthus litter and parasitism across two soil fertility levels. We measured the biomass and tissue nutrient concentration of three functional groups within these communities to determine their physiological response to resource abstraction and litter input by the parasite. We show that Rhinanthus alters the biomass and nutrient status of co-occurring plants with contrasting effects on different functional groups via the mechanism of nutrient-rich litter input. Critically, in the case of grass and total community biomass, this partially negates biomass reductions caused directly by parasitism. This demonstrates that the influence of parasitic plant litter on plant community structure can be of equal importance to the much-reported direct impacts of parasitism. We must consider both positive indirect (litter) and negative direct (parasitism) impacts of parasitic plants to understand their role in structuring plant communities.

Kidney pericytes: a novel therapeutic target in interstitial fibrosis

Chronic Kidney Disease affects approximately 8% of the population and contributes considerably to premature morbidity and mortality. Recently reported studies have highlighted an important role for resident microvascular pericytes in the pathogenesis of kidney fibrosis. Pericytes are emerging as the predominant source of the activated, matrix depositing, stromal cell population seen in progressive fibrosis. Further, pericyte activation leads to their detachment from the vasculature, triggers unstable microvasculature and leads to rarefaction. Strategies to modulate pericyte function in these processes are therefore therapeutically attractive. In this review we will first describe our current understanding of the structure and function of the pericyte and the role these cells play in angiogenesis and the pathogenesis of renal fibrosis. Novel therapeutic approaches targeting pericytes in murine models of renal disease will then be considered.

Biology of the renal pericyte

Pericytes are cells of mesenchymal origin that are intimately involved in the development and stabilization of vascular networks. Novel studies of their role in inflammation have identified that pericytes are not only major contributors to the activated matrix depositing myofibroblast populations seen in progressive renal fibrosis but perhaps even more importantly, the detachment of renal pericytes from the vasculature contributes to the microvasculature rarefaction and subsequent hypoxia associated with chronic kidney disease. In this review, our current understanding of the functioning of renal pericytes will be considered and set in the context of the wider literature that is currently available on this neglected population of cells.

TGFβ modulates cell-to-cell communication in early epithelial-to-mesenchymal transition

AIMS/HYPOTHESIS

A key pathology in diabetic nephropathy is tubulointerstitial fibrosis. The condition is characterised by increased deposition of the extracellular matrix, fibrotic scar formation and declining renal function, with the prosclerotic cytokine TGF-β1 mediating many of these catastrophic changes. Here we investigated whether TGF-β1-induced epithelial-to-mesenchymal transition (EMT) plays a role in alterations in cell adhesion, cell coupling and cell communication in the human renal proximal tubule.

METHODS

Whole-cell and cell compartment abundance of E-cadherin, N-cadherin, snail, vimentin, β-catenin and connexin-43 was determined in human kidney cell line (HK)2 and human proximal tubule cells with or without TGF-β1, using western blotting and immunocytochemistry, followed by quantification by densitometry. The contribution of connexin-43 in proximal tubule cell communication was quantified using small interfering RNA knockdown, while dye-transfer was used to assess gap junctional intercellular communication (GJIC). Functional tethering was assessed by single-cell force spectroscopy with or without TGF-β1, or by immunoneutralisation of cadherin ligation.

RESULTS

High glucose (25 mmol/l) increased the secretion of TGF-β1 from HK2 cells. Analysis confirmed early TGF-β1-induced morphological and phenotypical changes of EMT, with altered levels of adhesion and adherens junction proteins. These changes correlated with impaired cell adhesion and decreased tethering between coupled cells. Impaired E-cadherin-mediated adhesion reduced connexin-43 production and GJIC, these effects being mimicked by neutralisation of E-cadherin ligation. Upregulation of N-cadherin failed to restore adhesion or connexin-43-mediated GJIC.

CONCLUSIONS/INTERPRETATION

We provide compelling evidence that TGF-β1-induced EMT instigates a loss of E-cadherin, cell adhesion and ultimately of connexin-mediated cell communication in the proximal tubule under diabetic conditions; these changes occur ahead of overt signs of renal damage.

ANCA-associated vasculitis is linked to carriage of the Z allele of α₁ antitrypsin and its polymers

BACKGROUND

Small studies have linked α1 antitrypsin (α1AT) deficiency to patients with antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV).

OBJECTIVE

To test the validity and the mechanism of this association between α1AT and AAV.

METHODS

The distribution of α1AT deficiency alleles Z and S was compared between 856 White Europeans with AAV and 1505 geographic and ethnically matched healthy controls. Genotyping was performed by allelic discrimination assay.

RESULTS

were compared between cases and controls using χ(2) tests. The serum and renal biopsies for α1AT polymers were compared using the polymer-specific 2C1 antibody. The role of α1AT polymers in promoting inflammation was investigated by examining their ability to prime neutrophils for ANCA activation as assessed by CD62L shedding, superoxide production and myeloperoxidase degranulation. Results The Z but not the S allele was over-represented in the patients compared with controls (HR=2.25, 95% CI 1.60 to 3.19). Higher concentrations of polymers of α1AT were detected in serum from patients carrying the Z allele than in those not carrying the Z allele (median (IQR) 1.40 (0.91-3.32) mg/dl vs 0.17 (0.06-0.28) mg/dl, p<0.001); polymers of α1AT were also seen in the renal biopsy of a patient with vasculitic glomerulonephritis. Polymers of α1AT primed neutrophils with CD62L shedding and increased superoxide production following ANCA activation. Carriage of the Z allele was not associated with disease severity, survival or relapse.

CONCLUSIONS

The Z but not the S deficiency allele is associated with AAV. Polymers of α1AT are present in the serum and glomeruli of at least some patients with the Z allele, which may promote inflammation through priming of neutrophils.

Long- term outcome of paediatric patients with ANCA vasculitis

BACKGROUND

Primary systemic vasculitis presenting in childhood is an uncommon but serious condition. As these patients transfer to adult clinics for continuing care, defining long term outcomes with emphasis on disease and treatment- related morbidity and mortality is important. The aim of this study is to describe the long- term clinical course of paediatric patients with ANCA vasculitis.

METHODS

The adult patients in our vasculitis clinics who had presented in childhood, with a follow up time of greater than 10 years were included. We also reviewed the literature for articles describing the clinical outcome of paediatric patients with ANCA vasculitis.

RESULTS

We describe the clinical course of 8 adults who presented in childhood with ANCA vasculitis. 7 patients had Wegener's granulomatosis and 1 had microscopic polyangiitis. The median age at presentation was 11.5 years, and follow up time ranged form 11 to 30 years. Induction therapy for all patients was steroids and/or cyclophosphamide. Maintenance therapy was with azathioprine or mycophenolate mofetil. Biological agents were used in 3 patients for relapsed disease in adulthood only.Seven patients achieved complete remission. All patients experienced disease relapse, with a median of 4 episodes. Kidney function was generally well preserved, with median eGFR 76 ml/min. Only one patient developed end-stage renal failure and one patient died after 25 years of disease. Treatment-related morbidity rates were high; 7 suffered from infections, 4 were infertile, 2 had skeletal complications, and 1 developed malignancy.

CONCLUSION

Close long- term follow up of paediatric patients with ANCA vasculitis is imperative, as this patient cohort is likely to live long enough to develop significant treatment and disease- related morbidities. Prospective cohort studies with novel therapies including paediatric patients are crucial to help us determine the best approach to managing this complex group of patients. In addition, although not yet observed in our series, late cardiovascular morbidity remains a major longer-term potential concern for adult survivors of paediatric vasculitis.

The haemodynamic responses to venesection and the effects of cardiovascular disease

The haemodynamic effects of the venesection of one unit (450 ml) of blood over 9 min were measured using non-invasive techniques, in 14 healthy controls and 18 patients with coronary heart disease or hypertension. Venesection was associated with significant reductions in supine and standing systolic and diastolic blood pressure, stroke volume index and cardiac index, and increases in standing heart rate, in both patient groups. No significant differences were observed between the responses of subjects with and without cardiovascular disease. The authors conclude that, in contrast to established teaching, blood loss can be detected in its early stages by careful haemodynamic monitoring and that venesection can be performed safely without volume replacement in patients with stable cardiovascular disease.

Relapsed Wegener's granulomatosis after rituximab therapy--B cells are present in new pathological lesions despite persistent 'depletion' of peripheral blood

Wegener's granulomatosis (WG) is a chronic, relapsing, systemic autoimmune disease. Rituximab, a monoclonal antibody against human CD20, has shown promise as a novel treatment for WG. The monitoring of therapeutic B-cell 'depletion' by peripheral blood flow cytometry has been proposed to help monitor rituximab therapy. We report the case of a patient with known WG and granulomatous disease, successfully treated with rituximab, who relapsed whilst peripheral blood monitoring apparently indicated persistent B-cell depletion. Further investigations demonstrated CD20(+) B cells in tissue at sites of active disease. The implications for disease pathogenesis and clinical monitoring of disease are discussed.

3-D ultrasound guidance of surgical robotics using catheter transducers: feasibility study

The goal of this study was to test the feasibility of using a real-time 3-D (RT3D) ultrasound scanner with matrix array catheter probes to guide a surgical robot. We tested the accuracy of using 3-D catheter transducers with the 3-D measurement software of the scanner to direct automatically a robot arm that touched two needle tips together within a water tank and inside a vascular graft. RMS measurement error ranged from 2.4 to 3.4 mm for two catheter designs.

Nurse anaesthetic care during cataract surgery: a comparative quality assurance study

BACKGROUND

We studied whether a new model of nurse-provision of conscious sedation for cataract surgery maintained patient satisfaction and safety.

METHODS

We prospectively and non-randomly studied 106 patients who had outpatient cataract surgery on a day when an anaesthetist was present at the UBC, Vancouver Hospital Eye Care Centre, and 105 patients with no anaesthetist, but instead a surgical suite nurse trained to give conscious sedation was present. Questionnaires determined patient perception of well-being, pain, and anxiety before surgery, before discharge, at 48 hours and at 6 weeks postoperative. Hospital records and a surgeon questionnaire were used to determine complications. Ophthalmology records were used to determine visual acuity (preoperative and at 6 weeks).

RESULTS

No anaesthetic complications were reported in either group and there were no significant differences in surgical complications. Patient responses to assessments of discomfort, well-being, and anxiety, preoperatively and postoperatively, were very similar on the nurse days and anaesthetist days.

INTERPRETATION

Conscious sedation of cataract surgery patients can be safely and effectively provided by a trained nurse for selected patients. This nursing role is likely replicable in similar operating room settings.

Real-time three-dimensional transesophageal echocardiography for guiding interventional electrophysiology: feasibility study

At present, there are limited methods of acquiring three-dimensional visualization of cardiac structure and function in real-time during interventional electrophysiology procedures. Images acquired for integration of computerized tomography and magnetic resonance imaging with electroanatomic mapping systems are static and are obtained earlier in time. The purpose of this study was to test the feasibility of real-time three-dimensional transesophageal echocardiography for the guidance of interventional electrophysiological studies. A matrix array transducer with 504 channels operating at 5 MHz in a 1 cm diameter steerable esophageal probe was used in conjunction with a scanner capable of real-time 3D scanning of pyramidal volumes from 65 degrees to 120 degrees at rates up to 30 volumes per second. This device has a spatial resolution of approximately 3 mm at 5 cm depth. The authors acquired real-time three-dimensional images of anatomic landmarks of value for electrophysiological procedures in five closed chest canines. Real-time, three-dimensional ultrasound imaging was also used for visualization and guidance of interventional catheter devices within the canine heart. Real-time three-dimensional images of the atria, pulmonary veins, and coronary sinus were acquired. Real-time 3-D color flow Doppler was employed to confirm patency. Multiple image planes of image volumes and rendered views were used to track catheter position and orientation. Images of left veno-atrial junctions have been confirmed by dissection. This study has demonstrated the feasiblity of using real-time three-dimensional transesophageal echocardiography for guiding interventional electrophysiology. The technology has the potential to fill a niche as an adjunct modality for cost-effective real-time interventional guidance and assessment, providing catheter and pacing lead visualization simultaneously with functional volumetric cardiac imaging.

Integrated endoscope for real-time 3D ultrasound imaging and hyperthermia: feasibility study

The goal of this research is to determine the feasibility of using a single endoscopic probe for the combined purpose of real-time 3D (RT3D) ultrasound imaging of a target organ and the delivery of ultrasound therapy to facilitate the absorption of compounds for cancer treatment. Recent research in ultrasound therapy has shown that ultrasound-mediated drug delivery improves absorption of treatments for prostate, cervical and esophageal cancer. The ability to combine ultrasound hyperthermia and 3D imaging could improve visualization and targeting of cancerous tissues. In this study, numerical modeling and experimental measurements were developed to determine the feasibility of combined therapy and imaging with a 1 cm diameter endoscopic RT3D probe with 504 transmitters and 252 receive channels. This device operates at 5 MHz and has a 6.3 mm x 6.3 mm aperture to produce real time 3D pyramidal scans of 60-120 degrees incorporating 64 x 64 = 4096 image lines at 30 volumes/sec interleaved with a 3D steerable therapy beam. A finite-element mesh was constructed with over 128,000 elements in LS-DYNA to simulate the induced temperature rise from our transducer with a 3 cm deep focus in tissue. Quarter-symmetry of the transducer was used to reduce mesh size and computation time. Based on intensity values calculated in Field II using the transducer's array geometry, a minimum I(SPTA) of 3.6 W/cm2 is required from our endoscope probe in order to induce a temperature rise of 4 degrees C within five minutes. Experimental measurements of the array's power output capabilities were conducted using a PVDF hydrophone placed 3 cm away from the face of the transducer in a watertank. Using a PDA14 Signatec data acquisition board to capture full volumes of transmitted ultrasound data, it was determined that the probe can presently maintain intensity values up to 2.4 W/cm2 over indefinite times for therapeutic applications combined with intermittent 3D scanning to maintain targeting. These values were acquired using 8 cycle bursts at a prf of 6 kHz. Ex vivo heating experiments of excised pork tissue yielded a maximum temperature rises of 2.3 degrees C over 5 minutes of ultrasound exposure with an average rise of 1.8 +/- 0.2 degrees C over 5 trials. Modifications to the power supply and transducer array may enable us to reach the higher intensities required to facilitate drug delivery therapy.

Real-time 3D transesophageal echocardiography

Transesophageal echocardiography (TEE) is an essential diagnostic tool in patients with poor transthoracic echocardiographic windows or when detailed imaging of structures distant from the chest wall is necessary. A real-time 3D TEE probe has been fabricated in our laboratory in order to increase the amount of information available during a transesophageal procedure. The 1 cm diameter esophageal probe utilizes a 2-dimensional, 5 MHz array at its tip with a 6.3 mm diameter aperture, including 504 active channels. The array has a periodic vernier geometry with an element pitch of 0.18 mm, built onto a multilayer flexible (MLF) interconnect circuit. In order to accommodate 504 channels within the device, a 1 m long Gore MicroFlat cable was utilized for wiring the MLF to the corresponding system connectors. Pulse-echo tests in a water tank have yielded a -6 dB bandwidth of 25.3%. Fully connected to the system through 3 m of cable, the probe shows an average 50 omega insertion loss of-85 dB with a standard deviation of 4 dB, as determined through pitch-catch measurements for a sampling of 10 elements. Using the completed 3D TEE probe with the Volumetrics Medical Imaging 3D scanner, real-time volumetric images of in vivo canine cardiac anatomy have been acquired, displaying atrial views, mitral valve function and interventional catheter guidance.

Behavioral correction of Parkinsonian rats following the transplantation of immortalized fibroblasts genetically modified with TH and GCH genes

Eukaryotic plasmid vectors encoding the tyrosine hydroxylase (TH) gene and GTP cyclohydrolase-1 (GCH) gene were constructed and introduced into immortalized fibroblasts obtained from SV40 large antigen (LT(AG)) transformed rat primary fibroblasts. TH and GCH positive clones were selected and identified by immunohistochemistry and RT-PCR, respectively. Hemi-parkinsonian rats created using 6-hydroxydopamine (6-OHDA) were used to assess the therapeutic effect created by the co-implantation of immortalized fibroblasts genetically modified by TH or GCH genes. Animal behavior was significantly improved two weeks following implantation and behavioral correction was maintained for over 14 weeks. Behavioral improvement was paralleled by exogenous TH gene expression, identified by TH immunohistochemistry and RT-PCR analyses. The transplanted cells survived for at least 38 weeks as demonstrated by fibronectin immunohistochemical staining. Tumor formation or host reaction was not seen, although TH expression was negative for 20 weeks after the implantation. This work demonstrates that the co-transplantation of immortalized fibroblasts genetically modified by TH and GCH genes may be developed as a valuable approach to the treatment of Parkinson's disease.

Real-time cylindrical curvilinear 3-D ultrasound imaging

In patients who are obese or exhibit signs of pulmonary disease, standard transthoracic scanning may yield poor quality cardiac images. For these conditions, two-dimensional transesophageal echocardiography (TEE) is established as an essential diagnostic tool. Current techniques in transesophageal scanning, though, are limited by incomplete visualization of cardiac structures in close proximity to the transducer. Thus, we propose a 2D curvilinear array for 3D transesophageal echocardiography in order to widen the field of view and increase visualization close to the transducer face. In this project, a 440 channel 5 MHz two-dimensional array with a 12.6 mm aperture diameter on a flexible interconnect circuit has been molded to a 4 mm radius of curvature. A 75% element yield was achieved during fabrication and an average -6dB bandwidth of 30% was observed in pulse-echo tests. Using this transducer in conjunction with modifications to the beam former delay software and scan converter display software of the our 3D scanner, we obtained cylindrical real-time curvilinear volumetric scans of tissue phantoms, including a field of view of greater than 120 degrees in the curved, azimuth direction and 65 degrees phased array sector scans in the elevation direction. These images were achieved using a stepped subaperture across the cylindrical curvilinear direction of the transducer face and phased array sector scanning in the noncurved plane. In addition, real-time volume rendered images of a tissue mimicking phantom with holes ranging from 1 cm to less than 4 mm have been obtained. 3D color flow Doppler results have also been acquired. This configuration can theoretically achieve volumes displaying 180 degrees by 120 degrees. The transducer is also capable of obtaining images through a curvilinear stepped subaperture in azimuth in conjunction with a rectilinear stepped subaperture in elevation, further increasing the field of view close to the transducer face. Future work includes development of an array for adapting these modifications to a 6 mm diameter endoscope probe.

High expression of nicotinamide N-methyltransferase in patients with idiopathic Parkinson's disease

We have previously speculated that elevated levels of nicotinamide N-methyltransferase (NNMT), the primary catabolic enzyme of nicotinamide, may result in reduced Complex I activity in idiopathic Parkinson's disease (IPD) in two ways: (1) reduction in the levels of nicotinamide available for nicotinamide adenine dinucleotide synthesis; and (2) increased methylation of compounds such as tetrahydroisoquinolines and beta-carbolines, which are potent Complex I inhibitors. Expression of NNMT was assessed in 91 cerebella (53 IPD, 38 control) using immunohistochemistry coupled with quantitative digital image analysis. Control cerebella showed a distribution of expression ascribed to low, intermediate and high expressors with ratios of 1:2:1 categories. Expression in the parkinsonian cerebella was significantly higher than in the control group (control group median expression 17%, mean expression 16.6%, range 0-51%, standard deviation 11.4%, standard error 1.9%; IPD group median expression 46%, mean expression 53.7%, range 21-100%, standard deviation 23.4%, standard error 3.2%; P<0.0001; unpaired t-test with Welch correction (parametric) and Mann-Whitney U-test (non-parametric)). These results confirm that NNMT expression is elevated in IPD, which may ultimately lead to neurodegeneration via a reduction in Complex I activity.

Electrostatic micromachine scanning mirror for optical coherence tomography

Compact electrostatic micromirror structures for use in the scanning arm of an optical coherence tomography (OCT) system are described. These devices consist of millimeter-scale mirrors resting upon micrometer-scale polyimide hinges that are tilted by a linear micromachine actuator, the integrated force array (IFA). The IFA is a network of deformable capacitor cells that electrostatically contract with an applied voltage. The support structures, hinges, and actuators are fabricated by photolithography from polyimide-upon-silicon wafers. These devices were inserted into the scanning arm of an experimental OCT imaging system to produce in vitro and in vivo images at frame rates of 4 to 8 Hz.

Droperidol vs. prochlorperazine for benign headaches in the emergency department

OBJECTIVE

To compare the efficacy of droperidol with that of prochlorperazine for the treatment of benign headaches in emergency department (ED) patients.

METHODS

Prospective, randomized clinical trial in an urban ED. Patients were given either droperidol, 5 mg intramuscular (IM) or 2.5 mg intravenous (IV), or prochlorperazine, 10 mg IM or 10 mg IV. Measurements included side effects and the patient's pain perception as measured on a 100-mm visual analog scale (VAS) at baseline, 30, and 60 minutes after the medication was given. Data were analyzed using chi-square, two-tailed t-tests, and two-way analysis of variance (ANOVA) when appropriate.

RESULTS

During an eight-month period, 168 patients were enrolled. Eighty-two (48.8%) of the patients received droperidol; 86 (51.2%) received prochlorperazine. In the droperidol group, 49 (59.6%) received IM administration and 33 (40.4%) IV. In the prochlorperazine group, 57 (66.3%) received IM administration and 29 (33.7%) IV. Sixty minutes after the medication, the mean decrease in the VAS scores was 81.4% for droperidol and 66.9% for prochlorperazine (p = 0.001). At 30 minutes, 60.9% of the patients receiving droperidol and 44.2% of the patients receiving prochlorperazine had obtained at least a 50% reduction in their VAS scores (p = 0.09). At 60 minutes, 90.2% of the patients receiving droperidol and 68.6% of the patients receiving prochlorperazine had at least a 50% reduction in their VAS scores (p = 0.017). No difference between IM dosing and IV dosing was detected. Side effects, including dystonia, akathisia, and decreased level of consciousness, were seen in 15.2% of the patients receiving droperidol and 9.61% of the patients receiving prochlorperazine. No significant or persisting morbidity was detected.

CONCLUSIONS

Droperidol was more effective than prochlorperazine in relieving pain associated with benign headaches.

Real-time three-dimensional intracardiac echocardiography

Using catheter-mounted 2-D array transducers, we have obtained real-time 3-D intracardiac ultrasound (US) images. We have constructed several transducers with 64 channels inside a 12 French catheter lumen operating at 5 MHz. The transducer configuration may be side-scanning or beveled, with respect to the long axis of the catheter lumen. We have also included six electrodes to acquire simultaneous electrocardiograms. Using an open-chest sheep model, we inserted the catheter into the cardiac chambers to study the utility of in vivo intracardiac 3-D scanning. Images obtained include a cardiac four-chamber view, mitral valve, pulmonic valve, tricuspid valve, interatrial septum, interventricular septum and ventricular volumes. We have also imaged two electrophysiological interventional devices in the right atrium, performed an in vitro ablation study, and viewed the pulmonary veins in vitro.

Adverse events, including death, associated with the use of 1,4-butanediol

BACKGROUND

1,4-Butanediol is an industrial solvent that, when ingested, is converted to gamma-hydroxybutyrate, a drug of abuse with depressant effects, primarily on the central nervous system. After reports of toxic effects of gamma-hydroxybutyrate and its resultant regulation by the federal government, 1,4-butanediol and gamma-butyrolactone, another precursor of gamma-hydroxybutyrate and an industrial solvent, began to be marketed as dietary supplements. We investigated reports of toxic effects due to the ingestion of 1,4-butanediol and reviewed the related health risks.

METHODS

From June 1999 through December 1999, we identified cases of toxic effects of 1,4-butanediol involving patients who presented to our emergency departments with a clinical syndrome suggesting toxic effects of gamma-hydroxybutyrate and a history of ingesting 1,4-butanediol and patients discovered through public health officials and family members. We used gas chromatography-mass spectrometry to measure 1,4-butanediol or its metabolite, gamma-hydroxybutyrate, in urine, serum, or blood.

RESULTS

We identified nine episodes of toxic effects in eight patients who had ingested 1,4-butanediol recreationally, to enhance bodybuilding, or to treat depression or insomnia. One patient presented twice with toxic effects and had withdrawal symptoms after her second presentation. Clinical findings and adverse events included vomiting, urinary and fecal incontinence, agitation, combativeness, a labile level of consciousness, respiratory depression, and death. No additional intoxicants were identified in six patients, including the two who died. The doses of 1,4-butanediol ingested ranged from 5.4 to 20 g in the patients who died and ranged from 1 to 14 g in the nonfatal cases.

CONCLUSIONS

The health risks of 1,4-butanediol are similar to those of its counterparts, gamma-hydroxybutyrate and gamma-butyrolactone. These include acute toxic effects, which may be fatal, and addiction and withdrawal.

Phase II trial evaluating triplet chemotherapy using gemcitabine, paclitaxel, and carboplatin in the treatment of patients with advanced non-small cell lung cancer

The purpose of this study was to evaluate the combination of gemcitabine, paclitaxel, and carboplatin in patients with advanced non-small cell lung cancer. Previously untreated patients with stage IIIB or IV non-small cell lung cancer were enrolled into this trial. Sixty-nine patients from the phase II portion and eight patients from the phase I portion were treated with gemcitabine 1,000 mg/m2 intravenously on days I and 8, paclitaxel 200 mg/m2 as a 1-hour infusion on day 1, and carboplatin at an area under the curve of 5.0 intravenously on day 1. Treatment courses were repeated every 21 days. The phase II component of the study was completed at 13 community-based practices in the Minnie Pearl Cancer Research Network. Thirty-four of 71 fully evaluable patients had an objective response (48%, two complete and 32 partial responses). Twenty-five patients (35%) were stable and 12 (17%) progressed. The median response duration was 6 months (range, 3 to 14 months) and the median survival was 9.9 months, with 1- and 2-year survival rates of 47% and 21%, respectively. The combination of gemcitabine, paclitaxel, and carboplatin has been shown to be safe and effective; thus, this three-drug regimen will be compared with a standard two-drug regimen, paclitaxel/carboplatin, in a phase III study.

High-density flexible interconnect for two-dimensional ultrasound arrays

We present a method for fabricating flexible multilayer circuits for interconnection to 2-D array ultrasound transducers. In addition, we describe four 2-D arrays in which such flexible interconnect is implemented, including transthoracic arrays with 438 channels operating at up to 7 MHz and intracardiac catheter arrays with 70 channels operating at up to 7 MHz. We employ thin and thick film microfabrication techniques to batch produce the interconnect circuits with minimum dimensions of 12-mum lines, 40-mum vias, and 150-mum array pitch. The arrays show 50-Omega insertion loss of -60 to -84 dB and a fractional bandwidth of 27 to 67%. The arrays are used to obtain real time, in vivo volumetric scans.