Global patterns and drivers of plant-soil microbe interactions

Plant-soil feedback (PSF) is an important mechanism determining plant community dynamics and structure. Understanding the geographic patterns and drivers of PSF is essential for understanding the mechanisms underlying geographic plant diversity patterns. We compiled a large dataset containing 5969 observations of PSF from 202 studies to demonstrate the global patterns and drivers of PSF for woody and non-woody species. Overall, PSF was negative on average and was influenced by plant attributes and environmental settings. Woody species PSFs did not vary with latitude, but non-woody PSFs were more negative at higher latitudes. PSF was consistently more positive with increasing aridity for both woody and non-woody species, likely due to increased mutualistic microbes relative to soil-borne pathogens. These findings were consistent between field and greenhouse experiments, suggesting that PSF variation can be driven by soil legacies from climates. Our findings call for caution to use PSF as an explanation of the latitudinal diversity gradient and highlight that aridity can influence plant community dynamics and structure across broad scales through mediating plant-soil microbe interactions.

Effects of the invasive leafy spurge (Euphorbia esula L.) on plant community structure are altered by management history

Invasive species threaten biodiversity and ecosystem functioning, often causing changes in plant community composition and, thus, the functional traits of that community. Quantifying changes in traits can help us understand invasive species impacts on communities; however, both the invader and the plant community may be responding to the same environmental drivers. In North America, leafy spurge (Euphorbia esula L.) is a problematic invader that reduces plant diversity and forage production for livestock. Its documented effects on plant communities differ amongst studies, however, potentially due to differences in productivity or land management. To identify the potential effects of leafy spurge on plant communities, we quantified leafy spurge abundance, plant species richness, forage production, functional group composition and community weighted mean traits, intensively at a single site and extensively across ten sites differing in management. We then tested how leafy spurge abundance related to these variables as a function of site management activities. Leafy spurge abundance was consistently associated with fewer plant species, reduced forage production and more invasive grass. Community-weighted specific root length also consistently increased with leafy spurge abundance, suggesting that belowground competition may be important in determining co-existence with leafy spurge. Other changes were dependent on management. Native forbs were excluded as leafy spurge became more abundant, but only in grazed sites as these species were already absent from ungrazed sites. Taller plants better persisted in dense leafy spurge patches, but only in grazed sites, consistent with either facilitation of taller species via associational defences or competitive exclusion of shorter species in ungrazed sites and dense leafy spurge patches. These results show that, despite some emergent properties of invasion, management context can alter invasion impacts by causing changes in the plant community and its interactions with the invader.

Plant responses to soil biota depend on precipitation history, plant diversity, and productivity

Soil biota are critical drivers of plant growth, population dynamics, and community structure and thus have wide-ranging effects on ecosystem function. Interactions between plants and soil biota are complex, however, and can depend on the diversity and productivity of the plant community and environmental conditions. Plant-soil biota interactions may be especially important during stressful periods, such as drought, when plants can gain great benefits from beneficial biota but may be susceptible to antagonists. How soil biota respond to drought is also important and can influence plant growth following drought and leave legacies that affect future plant responses to soil biota and further drought. To explore how drought legacies and plant community context influence plant growth responses to soil biota and further drought, we collected soils from 12 grasslands varying in plant diversity and productivity where precipitation was experimentally reduced. We used these soils as inoculum in a growth chamber experiment testing how precipitation history (ambient or reduced) and soil biota (live or sterile soil inoculum) mediate plant growth and drought responses within an experimental plant community. We also tested whether these responses differed with the diversity and productivity of the community where the soil was collected. Plant growth responses to soil biota were positive when inoculated with soils from less diverse and productive plant communities and became negative as the diversity and productivity of the conditioning community increased. At low diversity, however, positive soil biota effects on plant growth were eliminated if precipitation had been reduced in the field, suggesting that diversity loss may heighten climate change sensitivity. Differences among species within the experimental community in their responses to soil biota and drought suggest that species benefitting from less drought sensitive soil biota may be able to compensate for some of this loss of productivity. Regardless of the plant species and soil origin, further drought eliminated any effects of soil biota on plant growth. Consequently, soil biota may be unable to buffer the effects of drought on primary productivity or other ecosystem functions as extreme events increase in frequency.

The complex and often confusing history, histology and histogenesis of mesonephric, STK11 adnexal tumour and mesonephric-like neoplasms of the upper female genital tract (including broad ligament)

Mesonephric lesions in the female genital tract are uncommon, with those arising from the upper tract being much less frequent than those developing in the lower tract (mesonephric hyperplasia and carcinoma). The most common upper tract lesions include rete cyst/cystadenoma and female adnexal tumour of Wolffian origin (FATWO). The integration of morphological, immunohistochemical and molecular studies on FATWOs has enabled recognition of a novel entity, the STK11 adnexal tumour, which is often associated with Peutz-Jeghers syndrome (~50%) and frequently has a salivary gland morphology but an unknown origin. Similarly, 'mesonephric-like' adenocarcinoma, an entity with striking similarities to mesonephric carcinoma but currently favoured to be of Müllerian derivation based on its association with other Müllerian tumours and molecular findings, has also been recently described, and may histologically mimic both FATWOs and STK11 adnexal tumours. In this review, we provide a historical overview of upper female genital tract mesonephric proliferations and discuss mesonephric lesions, STK11 adnexal tumour, mesonephric-like adenocarcinoma, and mimickers, the most common being endometrioid carcinoma.

Assessing the dual-mycorrhizal status of a widespread tree species as a model for studies on stand biogeochemistry

Viewing plant species by their mycorrhizal type has explained a range of ecosystem processes. However, mycorrhizal type is confounded with plant phylogeny and the environments in which mycorrhizal partners occur. To circumvent these confounding effects, "dual-mycorrhizal" plant species may be potential models for testing the influence of mycorrhizal type on stand biogeochemistry. To assess their use as models, duality in mycorrhizas within a single host species must be confirmed and factors underlying their variation understood. We surveyed roots, soils, and leaves of mature aspen (Populus tremuloides) across 27 stands in western Canada spanning two biomes: boreal forest and parklands. Aspen roots were mostly ectomycorrhizal with sporadic and rare occurrences of arbuscular mycorrhizas. We further tested whether a climate moisture index predicted abundance of ectomycorrhizal roots (number of ectomycorrhizal root tips m^-1 root length) surveyed at two depths (0-20 cm and 20-40 cm) and found that ectomycorrhizal root abundance in subsoils (20-40 cm) was positively related to the index. We subsequently examined the relationships between ectomycorrhizal root abundance, leaf traits, and slow and fast pools of soil organic carbon and nitrogen. The ratio of leaf lignin:N, but not its components, increased along with ectomycorrhizal root abundance in subsoils. Soil carbon and nitrogen pools were independent of ectomycorrhizal root abundance. Our results suggest that (1) categorizing aspen as dual-mycorrhizal may overstate the functional importance of arbuscular mycorrhizas in this species and life stage, (2) water availability influences ectomycorrhizal root abundance, and (3) ectomycorrhizal root abundance coincides with leaf quality.

Resistance of soil biota and plant growth to disturbance increases with plant diversity

Plant diversity is critical to the functioning of ecosystems, potentially mediated in part by interactions with soil biota. Here, we characterised multiple groups of soil biota across a plant diversity gradient in a long-term experiment. We then subjected soil samples taken along this gradient to drought, freezing and a mechanical disturbance to test how plant diversity affects the responses of soil biota and growth of a focal plant to these disturbances. High plant diversity resulted in soils that were dominated by fungi and associated soil biota, including increased arbuscular mycorrhizal fungi and reduced plant-feeding nematodes. Disturbance effects on the soil biota were reduced when plant diversity was high, resulting in higher growth of the focal plant in all but the frozen soils. These results highlight the importance of plant diversity for soil communities and their resistance to disturbance, with potential feedback effects on plant productivity.

Mechanisms of plant-soil feedback: interactions among biotic and abiotic drivers

Contents Summary 91 I. Introduction 91 II. Primary PSF mechanisms 91 III. Factors mediating the mechanisms of PSF 93 IV. Conclusions and future directions 94 Acknowledgements 95 Author contributions 95 References 95 SUMMARY: Plant-soil feedback (PSF) occurs when plants alter soil properties that influence the performance of seedlings, with consequent effects on plant populations and communities. Many processes influence PSF, including changes in nutrient availability and the accumulation of natural enemies, mutualists or secondary chemicals. Typically, these mechanisms are investigated in isolation, yet no single mechanism is likely to be completely responsible for PSF as these processes can interact. Further, the outcome depends on which resources are limiting and the other plants and soil biota in the surrounding environment. As such, understanding the mechanisms of PSF and their role within plant communities requires quantification of the interactions among the processes influencing PSF and the associated abiotic and biotic contexts.

Species pools, community completeness and invasion: disentangling diversity effects on the establishment of native and alien species

Invasion should decline with species richness, yet the relationship is inconsistent. Species richness, however, is a product of species pool size and biotic filtering. Invasion may increase with richness if large species pools represent weaker environmental filters. Measuring species pool size and the proportion realised locally (completeness) may clarify diversity-invasion relationships by separating environmental and biotic effects, especially if species' life-history stage and origin are accounted for. To test these relationships, we added seeds and transplants of 15 native and alien species into 29 grasslands. Species pool size and completeness explained more variation in invasion than richness alone. Although results varied between native and alien species, seed establishment and biotic resistance to transplants increased with species pool size, whereas transplant growth and biotic resistance to seeds increased with completeness. Consequently, species pools and completeness represent multiple independent processes affecting invasion; accounting for these processes improves our understanding of invasion.

Predicting species establishment using absent species and functional neighborhoods

Species establishment within a community depends on their interactions with the local environment and resident community. Such environmental and biotic filtering is frequently inferred from functional trait and phylogenetic patterns within communities; these patterns may also predict which additional species can establish. However, differentiating between environmental and biotic filtering can be challenging, which may complicate establishment predictions. Creating a habitat‐specific species pool by identifying which absent species within the region can establish in the focal habitat allows us to isolate biotic filtering by modeling dissimilarity between the observed and biotically excluded species able to pass environmental filters. Similarly, modeling the dissimilarity between the habitat‐specific species pool and the environmentally excluded species within the region can isolate local environmental filters. Combined, these models identify potentially successful phenotypes and why certain phenotypes were unsuccessful. Here, we present a framework that uses the functional dissimilarity among these groups in logistic models to predict establishment of additional species. This approach can use multivariate trait distances and phylogenetic information, but is most powerful when using individual traits and their interactions. It also requires an appropriate distance‐based dissimilarity measure, yet the two most commonly used indices, nearest neighbor (one species) and mean pairwise (all species) distances, may inaccurately predict establishment. By iteratively increasing the number of species used to measure dissimilarity, a functional neighborhood can be chosen that maximizes the detection of underlying trait patterns. We tested this framework using two seed addition experiments in calcareous grasslands. Although the functional neighborhood size that best fits the community's trait structure depended on the type of filtering considered, selecting these functional neighborhood sizes allowed our framework to predict up to 50% of the variation in actual establishment from seed. These results indicate that the proposed framework may be a powerful tool for studying and predicting species establishment.

Applying the dark diversity concept to nature conservation

Linking diversity to biological processes is central for developing informed and effective conservation decisions. Unfortunately, observable patterns provide only a proportion of the information necessary for fully understanding the mechanisms and processes acting on a particular population or community. We suggest conservation managers use the often overlooked information relative to species absences and pay particular attention to dark diversity (i.e., a set of species that are absent from a site but that could disperse to and establish there, in other words, the absent portion of a habitat-specific species pool). Together with existing ecological metrics, concepts, and conservation tools, dark diversity can be used to complement and further develop conservation prioritization and management decisions through an understanding of biodiversity relativized by its potential (i.e., its species pool). Furthermore, through a detailed understanding of the population, community, and functional dark diversity, the restoration potential of degraded habitats can be more rigorously assessed and so to the likelihood of successful species invasions. We suggest the application of the dark diversity concept is currently an underappreciated source of information that is valuable for conservation applications ranging from macroscale conservation prioritization to more locally scaled restoration ecology and the management of invasive species.

Macroecology of biodiversity: disentangling local and regional effects

Contents 404 I. 404 II. 404 III. 405 IV. 406 V. 407 VI. 408 409 References 409 SUMMARY: Macroecology of biodiversity disentangles local and regional drivers of biodiversity by exploring large-scale biodiversity relationships with environmental or biotic gradients, generalizing local biodiversity relationships across regions, or comparing biodiversity patterns among species groups. A macroecological perspective is also important at local scales: a full understanding of local biodiversity drivers, including human impact, demands that regional processes be taken into account. This requires knowledge of which species could inhabit a site (the species pool), including those that are currently absent (dark diversity). Macroecology of biodiversity is currently advancing quickly owing to an unprecedented accumulation of biodiversity data, new sampling techniques and analytical methods, all of which better equip us to face current and future challenges in ecology and biodiversity conservation.

Response to Comment on "Worldwide evidence of a unimodal relationship between productivity and plant species richness"

Tredennick et al. criticize one of our statistical analyses and emphasize the low explanatory power of models relating productivity to diversity. These criticisms do not detract from our key findings, including evidence consistent with the unimodal constraint relationship predicted by the humped-back model and evidence of scale sensitivities in the form and strength of the relationship.

Worldwide evidence of a unimodal relationship between productivity and plant species richness

The search for predictions of species diversity across environmental gradients has challenged ecologists for decades. The humped-back model (HBM) suggests that plant diversity peaks at intermediate productivity; at low productivity few species can tolerate the environmental stresses, and at high productivity a few highly competitive species dominate. Over time the HBM has become increasingly controversial, and recent studies claim to have refuted it. Here, by using data from coordinated surveys conducted throughout grasslands worldwide and comprising a wide range of site productivities, we provide evidence in support of the HBM pattern at both global and regional extents. The relationships described here provide a foundation for further research into the local, landscape, and historical factors that maintain biodiversity.

Callosal disconnection and limb-kinetic apraxia

According to Liepmann, patients with limb-kinetic apraxia (LKA) have a loss of upper limb deftness-dexterity. Prior studies have revealed in right-handed patients that, whereas injury of the left hemisphere induces an ipsilesional LKA, injury to the right hemisphere does not induce an ipsilesional LKA. There are at least two possible means by which the left hemisphere may influence the deftness of the left hand, either by callosal connections or by ipsilesional corticospinal projections. The purpose of this study was to learn whether a patient with a focal lesion of the corpus callosum had a callosal disconnection LKA. This 57-year-old right-handed man had a memory impairment, and upon brain imaging, was found to have a septum pellucidum cyst, which was causing mild ventricular obstruction to the occipital and temporal horns. He underwent an endoscopic-assisted fenestration of the septum pellucidum. Postoperative imaging revealed a lesion of the mesial portion of his corpus callosum and an assessment of praxis revealed that he had both a limb-kinetic and ideomotor apraxia of his left but not his right hand. The observation that this man had a callosal disconnection LKA of his left hand suggests that in some people it is the left hemisphere's premotor or motor cortex that enables the right hemisphere's motor system to program deft movements of the left hand.

Impact + resistance training improves bone health and body composition in prematurely menopausal breast cancer survivors: a randomized controlled trial

Our randomized controlled trial in prematurely menopausal breast cancer survivors showed that impact + resistance training prevented increases in percentage of body fat compared with controls and also improved BMD at the hip and prevented BMD loss at the spine among exercise-trained women who were menopausal for >1 year.

INTRODUCTION

Cancer treatment-related menopause worsens bone health and body composition in breast cancer survivors (BCS). We investigated whether impact + resistance training could improve bone mineral density (BMD), reduce bone turnover, build muscle, and decrease fat mass in BCS with premature menopause.

METHODS

We conducted a randomized controlled trial in 71 BCS (mean age, 46.5 years) within 5 years of treatment-related menopause. Women were randomly assigned to one of two groups: (1) impact + resistance training (prevent osteoporosis with impact + resistance (POWIR)) or (2) exercise placebo (FLEX) 3×/week for 1 year. Outcomes were hip and spine BMD (in grams per square centimeter) and body composition (percent body fat (%BF) and lean and fat mass (in kilograms)) by DXA and bone turnover markers (serum osteocalcin (in nanograms per milliliter) and urinary deoxypryrodinoline (in nanomoles per milliliter).

RESULTS

There were no significant group × time interactions for bone outcomes when using an intent-to-treat approach on the full sample. In analyses restricted to BCS who were menopausal for ≥1 year, POWIR increased BMD at the hip and slowed BMD loss at the spine compared with FLEX (femoral neck-POWIR, 0.004 ± 0.093 g/cm(2) vs. FLEX, -0.010 ± 0.089 g/cm(2); p < 0.01; spine-POWIR, -0.003 ± 0.114 g/cm(2) vs. FLEX, -0.020 ± 0.110 g/cm(2); p = 0.03). POWIR prevented increases in %BF (POWIR, 0.01 % vs. FLEX, 1.3 %; p < 0.04). Women with attendance to POWIR at ≥64 % had better improvements in %BF than women attending less often (p < 0.03).

CONCLUSION

Impact + resistance training may effectively combat bone loss and worsening body composition from premature menopause in BCS.

New insight into transient contrast enhancement on computed tomography after endovascular treatment of stroke

Transient contrast enhancement on computed tomography following endovascular treatment of stroke is a recognized entity that has been previously reported. Technological advances in brain imaging now have the potential to explore and refine its proposed etiology. We describe three patients in whom the location of contrast enhancement correlates with decreased cerebral blood volume on pre-therapeutic CT perfusion studies and with restricted diffusion on MRI. In this regard, contrast enhancement demarcated areas of completed cerebral infarction. The diagnostic and etiological implications are discussed.

Evaluating the relationship between competition and productivity within a native grassland

Ideas about how plant competition varies with productivity are rooted in classic theories that predict either increasing (Grime) or invariant (Tilman) competition with increasing productivity. Both predictions have received experimental support, although a decade-old meta-analysis supports neither. Attempts to reconcile the conflicting predictions and evidence include: expanding the theory to include other conditions (e.g. stress gradient hypothesis), development of indices to differentiate either the 'intensity' or 'importance' of competition, a focus on resource supply and demand, and explicit recognition that both growth and survival may exhibit different relationships with productivity. To determine which of these theories accurately predict how competition varies with productivity within a native grassland site, we estimated competitive intensity and relative competitive importance using 22 species across the range of productivity naturally occurring within that site. Plant performance was measured as survival and size with and without neighbours and the local environment was quantified according to variability in standing crop, gross water supply, and net water supply. On average, neighbours weakly facilitated seedling survival, but strongly reduced seedling growth. For both seedling survival and growth, relative competitive importance and competitive intensity declined with some measure of productivity; neighbour effects on survival declined with standing crop, while effects on growth declined with gross water supply. These results add to the growing evidence that plant-plant interactions vary among life history components with different life history components contingent upon separate environmental factors. Although the range of productivity measured in this study was not large, our results do not support the theories of Grime or Tilman. However, our results are consistent with the meta-analysis and parts of other theories, although no single theory is capable of explaining the entirety of these results. This suggests that, at least in moderately productive grasslands, new theory needs to be developed.

The Role of Multi Detector Computed Tomographic Imaging Prior to Clinic Consultation in Patients Suspected to Have Lung Cancer

Background

Scanning patients early in their diagnostic journey helps in differentiating benign from malignant aetiology. There is increasing pressure on diagnostic practices for rapid diagnoses and thereby early commencement of treatment in patients suspected to have lung cancer (LC). In our practice, multi detector computed tomography (MDCT) imaging is performed in selected patients referred to the LC service prior to them seeing a chest physician in the LC clinic. This study evaluates the role of such practice and reviews its potential impact on LC services.

Methods

Prospective review of our practice from January 2007 to Apr 2007 was performed. Consecutive patients referred to the service with suspected LC were included. Chest radiograph (CXR) report and clinical information from general practitioners were reviewed and graded as high, medium or low risk for presence of LC. Patients with sufficient clinical and/or radiological concern underwent MDCT imaging prior to their clinic. Combined risk scores and modified risk scores were formulated and assessed against MDCT findings.

Results

A total of 139 patients were referred to the service, 124 of these had pre-clinic MDCT. Fifty-three patients (43%) had malignancy, 39 (31%) had non-malignant significant abnormalities, 17 (14%) had other incidental findings and 15 (12%) were normal. Modified combined risk score was the best predictor of presence of cancer.

Conclusion

Pre-clinic MDCT scanning in patients with suspected LC is feasible and has a promising role in the modern care of LC patients. It also empowers physicians with additional information at the primary consultation.

Abstract P4-06-24: KLF8 Induction of Mammary Epithelial Stem Cell Formation and Tumorigenesis by Regulating EMT-Associated MicroRNAs

Although it is well established that the epithelial-mesenchymal transition (EMT) generates cells with properties of stem cells, the molecularmechanisms responsible for this change remain largely undefined. We set out to identify the mechanisms by examining the expression of stem cell markers as well as microRNAs in MCF-10A cells during EMT induction. By immunostaining and FACS analysis, we found that during EMT induction by either TGF-β treatment or overexpression of KLF8, both the expression of CD44high/CD24low and the activity of aldehyde dehydrogenase (ALDH) were dramatically increased. Using microRNA PCR array, we identified a microRNA signature associated with the EMT. Using microRNA inhibitor, We further demonstrated that one of the microRNAs, miR-146a, is upregulated and plays an important role in keeping the stem cell percentage during EMT induced by both TGF-β and KLF8, as revealed by manipulation of miR-146a expression, analysis of the stem cell markers and mammosphere growth. Taken together, these results highlight a novel role for miR-146a in regulating the stem-like cell induction from MCF-10A cells by EMT. Experiments are in progress to investigate the contribution of KLF8-regulated expression of miR146a and its targets to the stem cell induction and transformation. Supported by: NIH, ACS, Komen and NYSTEM grants to J.Z.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-06-24.

Thoracic ultrasound prior to medical thoracoscopy improves pleural access and predicts fibrous septation

BACKGROUND AND OBJECTIVE

Medical thoracoscopy (MT) is indicated for the investigation of unexplained pleural exudates. Not all MT units create artificial pneumothoraces because of time. Difficult pleural space access and thick fibrous adhesions may prevent MT and pleurodesis, respectively. The potential role of thoracic ultrasound (TUS) pre-MT has not been fully evaluated. We hypothesized TUS would reduce failure to access the pleural space and enable detection of thick fibrous adhesions.

METHODS

Thirty patients underwent single port MT consecutively for investigation of pleural exudates without pre-MT TUS over a 6-month period. Over the following 6 months, 30 consecutive patients underwent TUS immediately prior to MT. Pleural access rate and thick fibrous adhesion detection at both MT and TUS were recorded.

RESULTS

In the non-TUS cohort, pleural space access failure occurred in 16.7% (leading to five extra procedures), versus no failures in the TUS cohort (P = 0.0522). There were no differences in prevalence of MT fibrous adhesions between cohorts. TUS identified all cases of fibrous septation versus only 12.5% identified by CT in the non-TUS cohort (P = 0.001). All identified cases of thick fibrous septation on TUS did not receive pleurodesis at MT. TUS detected useful ancillary features in 43% of cases.

CONCLUSIONS

A strong trend to reduction in single port MT pleural access failure was noted with pre-MT TUS thus reducing extra procedures and the need for artificial pneumothoraces. Pre-MT TUS also reliably detects thick fibrous adhesions at MT. TUS may also detect useful ancillary features. This study provides a rationale for ultrasound-guided single port MT if a pneumothorax is not created.

Current status of medical pleuroscopy

Medical pleuroscopy (MP) offers a safe and minimally invasive tool for interventional pulmonologists. It allows diagnosis of unexplained effusion, while at the same time allowing drainage and pleurodesis. It can also help in the diagnosis of diffuse interstitial disease or associated peripheral lung abnormality in the presence of effusion. It can have a therapeutic role in pneumothorax and hyperhidrosis or chronic pancreatic pain. This article reviews the technical aspects and range of applications of MP.

Endobronchial ultrasound guided transbronchial needle aspiration

Staging for non-small cell lung cancer (NSCLC) requires accurate assessment of the mediastinal lymph nodes which determines treatment and outcome. As radiological staging is limited by its specificity and sensitivity, it is necessary to sample the mediastinal nodes. Traditionally, mediastinoscopy has been used for evaluation of the mediastinum especially when radical treatment is contemplated, although conventional transbronchial needle aspiration (TBNA) has also been used in other situations for staging and diagnostic purposes. Endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA) offers a minimally invasive alternative to mediastinoscopy with additional access to the hilar nodes, a better safety profile, and it removes the costs and hazards of theatre time and general anaesthesia with comparable sensitivity, although the negative predictive value of mediastinoscopy (and sample size) is greater. EBUS-TBNA also obtains larger samples than conventional TBNA, has superior performance and theoretically is safer, allowing real-time sampling under direct vision. It can also have predictive value both in sonographic appearance of the nodes and histological characteristics. EBUS-TBNA is therefore indicated for NSCLC staging, diagnosis of lung cancer when there is no endobronchial lesion, and diagnosis of both benign (especially tuberculosis and sarcoidosis) and malignant mediastinal lesions. The procedure is different than for flexible bronchoscopy, takes longer, and requires more training. EBUS-TBNA is more expensive than conventional TBNA but can save costs by reducing the number of more costly mediastinoscopies. Revenue based tariff systems have been slow to reflect the innovation of techniques such as EBUS-TBNA. In the future, endobronchial ultrasound may have applications in airways disease and pulmonary vascular disease.

A prospective study of conventional transbronchial needle aspiration: performance and cost utility

BACKGROUND

Conventional transbronchial needle aspiration (TBNA) is a cheap, minimally invasive tool for lung cancer staging and diagnosis. Endobronchial ultrasound-guided TBNA (EBUS-TBNA) is more sensitive but is more expensive and less widely available. We describe a prospective analysis of TBNA diagnostic, staging and cost utility in a centre in the UK.

OBJECTIVES

To illustrate the potential diagnostic, staging and cost utility of a low cost conventional TBNA service.

METHODS

A prospective analysis of 79 TBNA procedures over a 2-year period was performed looking at performance and cost utility in a 'mixed' cohort with variable pre-test probability of malignancy (year 1) followed by a high probability cohort (year 2).

RESULTS

TBNA avoided mediastinoscopy in 25% of the cases overall (37% in high probability vs. 13% in the 'mixed' cohort, p = 0.03). The overall prevalence of malignancy was 84%, sensitivity 79%, negative predictive value 58% and accuracy 85%. Diagnostic utility varied with pre-test probability and nodal station. TBNA down-staged 8% of lung cancer patients to receive surgery and confirmed the pre-treatment stage (inoperability) in 74%. TBNA led to theoretical cost savings of GBP 560 per patient.

CONCLUSIONS

TBNA can achieve a high diagnostic sensitivity for cancer in high probability patients and stage the majority appropriately, thereby avoiding unnecessary mediastinoscopies and reducing costs. It may also down-stage a minority to have surgery. TBNA is cheap, routinely available and learnable. As EBUS-TBNA will take time to develop due to its costs, all respiratory centres should perform TBNA at flexible bronchoscopy in suspected lung cancer with accessible mediastinal adenopathy.

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA): applications in chest disease

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) offers a minimally invasive option for staging the mediastinum in suspect lung cancer but also in the diagnosis of mediastinal lesions accessible from the airway. This review is aimed at centres considering establishing an EBUS service that may not be so familiar with the technique. It focuses primarily on technical aspects of EBUS-TBNA, training issues, cost considerations, indications, advantages and disadvantages compared with other mediastinal sampling techniques as well as some reference to its performance in clinical studies. In summary, EBUS-TBNA is primarily used for staging non-small cell lung cancer, especially for bulky mediastinal disease and discrete N2 or N3 disease on CT, but also used for the diagnosis of unexplained mediastinal lymphadenopathy. For radical treatment staging, mediastinoscopy is still used at many centres and negative EBUS-TBNA results should be corroborated by mediastinoscopy. In the future, EBUS-TBNA may be used for staging the radiologically normal mediastinum and in re-staging. It is a procedure that can be taught with ease by an experienced operator, has numerous advantages over mediastinoscopy and is potentially cost saving by reducing the number of mediastinoscopies and associated peri-operative support required.

A local anaesthetic video-assisted thoracoscopy service: prospective performance analysis in a UK tertiary respiratory centre

INTRODUCTION

Local anaesthetic video-assisted thoracoscopy (LAVAT) is a safe, reliable and therapeutic procedure used by respiratory physicians in the management of pleural disease, especially pleural malignancy. We describe a prospective analysis of a UK LAVAT service set up in a tertiary respiratory centre to complement an existing large surgical video-assisted thoracic surgery (VATS) service.

METHODS

A prospective analysis of 125 LAVAT procedures over a 34-month period was performed looking at a variety of quality control endpoints comparing them to national thoracic surgical VATS standards.

RESULTS

Talc pleurodesis was effective in over 86% of cases and this did not significantly lengthen bed stay (median 4.5 days). Bed stay was also unchanged between the ages of 60-89 years. Over 77% of the 48 patients with proven metastatic pleural lung malignancy or mesothelioma received either surgical decortication or oncological treatment (palliative chemotherapy in 57%). In only 6% were biopsies not possible because of technical factors. LAVAT biopsies had a diagnostic accuracy of 97.4%, sensitivity 95.4%, specificity 100%, positive predictive value 100%, and negative predictive value 94.7%. Our complication rate was 4% and mortality rate 0.8%.

DISCUSSION

Our LAVAT service meets surgical VATS standards for diagnosis and safety with a good pleurodesis efficacy rate. It complements our surgical VATS service, offering a pleural diagnostic service for patients with non-complex pleural exudates or too frail for VATS. Our data demonstrate there is a demand and potential for respiratory physicians dealing with pleural malignancy to develop LAVAT and enhance their local lung cancer and pleural diagnostic pathway.

A performance and theoretical cost analysis of endobronchial ultrasound-guided transbronchial needle aspiration in a UK tertiary respiratory centre

BACKGROUND

New innovative techniques can improve patient care but may not be appropriately funded. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS) offers a minimally invasive mediastinal staging and diagnostic method for suspected lung cancer.

AIM

We report the performance and cost analysis of a newly established EBUS service in a prospective real world cohort of patients to assess the impact of Payment by Results (PbR).

DESIGN

Prospective cohort study.

METHODS

Fifty-four patients between June 2008 and April 2009 underwent EBUS for evaluation of unexplained mediastinal lymphadenopathy on CT. Cost analysis was performed from local Trust financial data and 2008-09 tariffs.

RESULTS

EBUS had an 89% sensitivity, 75% negative predictive value and 92% accuracy for malignancy. EBUS coding was inaccurate in 15.6% of cases. The actual cost of an EBUS is 1252-1433 pounds but is coded as a standard bronchoscopy (561 pounds). EBUS reduces health community costs by 107824 pounds/year, as a result of a Primary Care Trust cost saving of 113968 pounds/year and a Trust cost deficit of 6144 pounds/year. Coding inaccuracies further alter the Primary Care Trust costs.

CONCLUSION

Medical innovation is fundamental to improved patient care. EBUS can potentially reduce morbidity for lung cancer patients and save health community costs. However, with PbR the service provider delivers this at a loss as the tariffs do not reflect innovation and because of coding inaccuracies. We suggest tariffs for innovative procedures need to reflect the true cost.

Changes in lung cancer incidence in South Asians in Leicester, 1990-2005

BACKGROUND

A previous study showed that lung cancer incidence in Leicester's South Asian (SA) population had increased between 1990 and 1999. We expanded the original data set to determine if this increase had continued in recent years.

METHODS

All patients diagnosed with lung cancer in Leicester between 1990 and 2005 were identified. Ethnicity was assigned using Nam Pechan software, deprivation by Townsend score. Using Poisson regression, incidence rate ratios (IRRs) were calculated to assess variations in incidence by ethnicity, deprivation and period of diagnosis.

RESULTS

Comparing patients diagnosed in 2000-2005 with those in 1990-1994, the risk of lung cancer increased in the SA men (IRR: 1.67 (95% CI: 0.99, 2.78)) whereas in the non-South Asian (NSA) men, it had fallen (IRR: 0.84 (95% CI: 0.76, 0.94)). Comparing patients diagnosed in 2000-2005 with those in 1995-1999 an increase continued in the SA men (IRR: 1.11 (95% CI: 0.71-1.74)). A significant rise was observed in the NSA women comparing those diagnosed from 2000-2005 to 1995-1999 (IRR: 1.16 (95% CI: 1.01, 1.33)).

CONCLUSION

Lung cancer is an important public health issue amongst SAs in Leicester and has increased significantly since the early 1990s, with rates sustained in the more recent years of 2000-2005. Changes in the rates of lung cancer in SA and NSA populations are likely to be due to changing smoking habits.

Investigating the diet of the omnivorous mirid Dicyphus hesperus using stable isotopes

Omnivory involves numerous feeding relationships and a complex web of interactions. When using omnivores in biocontrol, these interactions need to be understood to maximize feeding on the target species and minimize non-target interactions. Dicyphus hesperus is used along with Encarsia formosa for biocontrol of whiteflies in greenhouse tomato crops. Dicyphus hesperus is a generalist omnivore which feeds on all components of the system. To quantify these interactions, stable isotope analysis was used to identify trophic position with nitrogen isotopes (delta15N) and plant sources with carbon isotopes (delta13C). Feeding trials were used to establish baseline isotopic data for D. hesperus and their diet, including Verbascum thapsus, an alternative plant food. Cage trials were used to monitor population abundances and the isotopic signature of D. hesperus. In feeding trials, D. hesperus were enriched relative to their food, suggesting an elevated trophic position. However, large amounts of isotopic variation were found within all diet components, with only V. thapsus exhibiting a distinct signature. In cage trials, the average delta15N and delta13C of the omnivore declined over time, coinciding with declines in total available prey, though it may be confounded by changes in temperature. The range of delta13C, but not the range of delta15N, also declined over time. This suggests a change in the plant source within the diet, but also some unquantified variability within the population. We suggest that diet variability exists within D. hesperus populations, declining as prey become less abundant.

Mediastinal staging procedures in lung cancer: EBUS, TBNA and mediastinoscopy

PURPOSE OF REVIEW

There is increasing awareness of minimally invasive endoscopic techniques for mediastinal staging in lung cancer. Traditionally, cervical mediastinoscopy has been utilized. Endobronchial ultrasound-guided fine needle aspiration (EBUS) has recently emerged as a potential alternative.

RECENT FINDINGS

EBUS has sensitivity for lung cancer which is at least equivalent (if not superior) to cervical mediastinoscopy. However, cervical mediastinoscopy remains superior to EBUS and other techniques in its high negative predictive value. More recent data suggest EBUS may have a role in presurgical staging of radiologically normal subcentimetre nodes and its negative predictive value may be equivalent to surgical staging. Ongoing comparative studies between EBUS and cervical mediastinoscopy may well clarify relative performance and cost analyses.

SUMMARY

Currently, insufficient data are present to recommend replacing cervical mediastinoscopy with EBUS for lung cancer staging; the negative predictive value of EBUS requires validation. However, EBUS can be recommended for initial staging as a minimally invasive option provided negative results are followed by cervical mediastinoscopy. This would also allow cervical mediastinoscopy to be reserved for re-staging. Conventional transbronchial needle aspiration has a limited role only as a first-line staging procedure but may aid diagnosis. In the future, EBUS may have a role in presurgical staging of the radiologically normal mediastinum and re-staging if prior staging is done by cervical mediastinoscopy.

Retrospective analysis of Healthcare Resource Group coding allocation for local anaesthetic video-assisted 'medical' thoracoscopy in a UK tertiary respiratory centre

BACKGROUND

Correct service costing is essential but may not always be done accurately.

AIM

To assess the accuracy of Healthcare Resource Group (HRG) coding allocation for patients undergoing local anaesthetic video-assisted thoracoscopy (LAVAT) against predicted codes under Payment by Results (PbR).

DESIGN

Single centre retrospective study. Tertiary respiratory centre in Leicestershire.

METHODS

One hundred twenty-five patients undergoing LAVAT from July 2005 to July 2008.

MAIN OUTCOME MEASURES

Predicted and actual revenue per LAVAT episode based on predicted and actual HRG codes allocated.

RESULTS

Among 125 patients undergoing LAVAT, the actual HRG code matched the predicted code in only 39 cases (31.2%), odds ratio (OR) 0.002, 95% confidence intervals (CIs) 0.0001-0.03, P < 0.0001. In 51 cases (40.8%), this resulted in a median (interquartile range) excess of PbR revenue of 574 pounds (574-1366) per episode; a total estimated overspend of 29,274 pounds. In 35 cases (28.0%), this resulted in a median underspend of --1093 pounds (-1285 to -851) per episode; a total estimated underspend of 38,529 pounds, with a total estimated financial error of 67,529 pounds. The net median (interquartile range) difference for PbR-related revenue was 0 pounds (-89 to + 574). Factors associated with coding discrepancy were longer length of stay (OR = 2.52, 95% CIs = 1.09-5.81, P = 0.03) and talc pleurodesis (OR = 2.25, 95% CI = 1.01-4.99, P = 0.06).

CONCLUSION

HRG coding allocation errors occur frequently. The potential financial implications of this are significant for providers and commissioners. Future strategies are required at multiple levels (NHS Trust, Primary Care Trust and Department of Health) to minimize future discrepancies and financial error.

An alpha-fetoprotein-derived peptide reduces the uterine hyperplasia and increases the antitumour effect of tamoxifen

Tamoxifen (Tam) is effective for the treatment and prevention of breast cancer. However, it has toxic drawbacks and has limited-duration utility because, over time, human tumours become refractory to Tam. Recently, a new nontoxic peptide, alpha-fetoprotein-derived peptide (AFPep) has been proposed for the treatment and prevention of breast cancer. The purpose of this paper is to determine whether combining AFPep with Tam would increase efficacy and reduce toxicity in experimental models of breast cancer. Low doses of AFPep and Tam were more effective in combination than either agent alone against breast cancer growth in cell culture, in tumour-xenografted mice, and in carcinogen-exposed rats. alpha-Fetoprotein-derived peptide interfered with Tam-induced uterine hyperplasia in immature mice, and showed no toxic effects. Unlike Tam, AFPep did not inhibit binding of oestradiol (E(2)) to oestrogen receptor (ER). Thus, these two agents utilise different mechanisms to interfere with ER functionality, yet work cooperatively to reduce breast cancer growth and alleviate Tam's troubling toxicity of uterine hyperplasia and appear to be a rational combination for the treatment of ER-positive breast cancer.

Synthetic peptide derived from alpha-fetoprotein inhibits growth of human breast cancer: investigation of the pharmacophore and synthesis optimization

Asynthetic peptide that inhibits the growth of estrogen receptor positive (ER+) human breast cancers, growing as xenografts in mice, has been reported. The cyclic 9-mer peptide, cyclo[EMTOVNOGQ], is derived from alpha-fetoprotein (AFP), a safe, naturally occurring human protein produced during pregnancy, which itself has anti-estrogenic and anti-breast cancer activity. To determine the pharmacophore of the peptide, a series of analogs was prepared using solid-phase peptide synthesis. Analogs were screened in a 1-day bioassay, which assessed their ability to inhibit the estrogen-stimulated growth of uterus in immature mice. Deletion of glutamic acid, Glu1, abolished activity of the peptide, but glutamine (Gln) or asparagine (Asn) could be substituted for Glu1 without loss of activity. Methionine (Met2) was replaced with lysine (Lys) or tyrosine (Tyr) with retention of activity. Substitution of Lys for Met2 in the cyclic molecule resulted in a compound with activity comparable with the Met2-containing cyclic molecule, but with a greater than twofold increase in purity and corresponding increase in yield. This Lys analog demonstrated anti-breast cancer activity equivalent to that of the original Met-containing peptide. Therefore, Met2 is not essential for biologic activity and substitution of Lys is synthetically advantageous. Threonine (Thr3) is a nonessential site, and can be substituted with serine (Ser), valine (Val), or alanine (Ala) without significant loss of activity. Hydroxyproline (Hyp), substituted in place of the naturally occurring prolines (Pro4, Pro7), allowed retention of activity and increased stability of the peptide during storage. Replacement of the first Pro (Pro4) with Ser maintains the activity of the peptide, but substitution of Ser for the second Pro (Pro7) abolishes the activity of the peptide. This suggests that the imino acid at residue 7 is important for conformation of the peptide, and the backbone atoms are part of the pharmacophore, but Pro4 is not essential. Valine (Val5) can be substituted only with branched-chain amino acids (isoleucine, leucine or Thr); replacement by d-valine or Ala resulted in loss of biologic activity. Thus, for this site, the bulky branched side chain is essential. Asparagine (Asn6) is essential for activity. Substitution with Gln or aspartic acid (Asp), resulted in reduction of biologic activity. Removal of glycine (Gly8) resulted in a loss of activity but nonconservative substitutions can be made at this site without a loss of activity indicating that it is not part of the pharmacophore. Cyclization of the peptide is facilitated by addition of Gln9, but this residue does not occur in AFP nor is it necessary for activity. Gln9 can be replaced with Asn, resulting in a molecule with similar activity. These data indicate that the pharmacophore of the peptide includes side chains of Val5 and Asn6 and backbone atoms contributed by Thr3, Val5, Asn6, Hyp7 and Gly8. Met2 and Gln9 can be modified or replaced. Glu1 can be replaced with charged amino acids, and is not likely to be part of the binding site of the peptide. The results of this study provide information that will be helpful in the rational modification of cyclo[EMTOVNOGQ] to yield peptide analogs and peptidomimetics with advantages in synthesis, pharmacologic properties, and biologic activity.

Gene frequencies of human platelet antigens 1-5 in indigenous Australians in Western Australia

The frequencies of human platelet antigen (HPA) systems vary between different racial groups; however, HPA frequency data for some racial groups are still incomplete. We report the distribution of HPA 1-5 systems in Australian Aborigines from a remote community in the north-west of Australia and compare our findings with HPA observed in a Western Australian blood donor population. Using a polymerase chain reaction (PCR) with sequence-specific primers, 185 indigenous Australians and 1000 Western Australian blood donors were genotyped for each of the HPA 1-5 systems. Comparison of gene frequencies of alleles from HPA-1, -2, -3 and -5 systems showed significant differences between Aboriginal people and Western Australian blood donors (P < 0.001). In particular, the frequency of HPA-3b (0.068) in the Australian Aboriginals, from this study, was one of the lowest reported, whilst the frequency of HPA-5b (0.246) was one of the highest for this allele. Gene frequencies were similar to those reported for central Australian Aborigines but with no other ethnic group. In conclusion, this study confirms significant differences in HPA distributions between indigenous Australians, Australian blood donors and other racial groups. These results indicate a higher potential risk of alloimmunization to HPA-1, -2 and -3 in Australian Aborigines receiving transfusion therapy from a Caucasian blood donor population, thereby having practical implications for transfusion and pregnancy risks in people of Aboriginal origin.

Development of a synthetic cyclized peptide derived from alpha-fetoprotein that prevents the growth of human breast cancer

The peptide, EMTPVNPG, derived from alpha-fetoprotein, inhibits estrogen-stimulated growth of immature mouse uterus and estrogen-dependent proliferation of human breast cancer cells. However, the biological activities of the peptide diminish over time in storage, even when in the lyophilized state, probably because of peptide aggregation through hydrophobic interaction among monomers. Two analogs of EMTPVNPG were designed with the intent of minimizing aggregation and retaining biological activity during prolonged storage. EMTOVNOG, where O is 4-hydroxyproline, is a linear peptide generated by substituting 4-hydroxyproline for the two prolines, thereby increasing peptide hydrophilicity. This analog exhibited a dose-dependent inhibition of estrogen-stimulated growth of immature mouse uterus similar to that of EMTPVNPG (maximal activity at 1 microg/mouse). A second analog, cyclo-(EMTOVNOGQ), a hydrophilic, cyclic analog with increased conformational constraint, was as potent as the other peptides in its inhibition of estrogen-dependent growth of immature mouse uterus, and had an expanded effective dose range. Both linear and cyclized hydroxyproline-substituted analogs exhibited indefinite shelf-life. Furthermore, both analogs inhibited the estrogen-dependent growth of MCF-7 human breast cancer growing as a xenograft in SCID mice. These analogs may become significant, novel agents for the treatment of breast cancer.

Two new loci affecting cell division identified as suppressors of an ftsQ-null mutation in Streptomyces coelicolor A3(2)

Mutations in fts genes partially or completely block both vegetative cell division and sporulation septation in the filamentous bacterium Streptomyces coelicolor A3(2). Using a novel screen, we independently isolated two double-mutant strains, each containing a spontaneous suppressor mutation, which partially restores division to an ftsQ-null mutant. Genetic complementation experiments revealed that the suppressor mutations alone confer no observable defect in sporulation. The suppressor mutations were genetically mapped to regions of the chromosome, distinct from each other and the division and cell wall cluster containing ftsQ. Therefore, the genes identified by the suppressor mutations were named sqnA and sqnB (suppressor of ftsQ-null) and may be representatives of a novel class of genes involved in cell division or the regulation of cell division in this mycelial organism.