Environmental DNA methods for biosecurity and invasion biology in terrestrial ecosystems: Progress, pitfalls, and prospects

Analysis of environmental DNA (eDNA) enables indirect detection of species without the need to directly observe and sample them. For biosecurity and invasion biology, eDNA-based methods are useful to address biological invasions at all phases, from detecting arrivals to confirming eradication of past invasions. We conducted a systematic review of the literature and found that in biosecurity and invasion biology, eDNA has primarily been used to detect new incursions and monitor spread in marine and freshwater ecosystems, with much slower uptake in terrestrial ecosystems, reflecting a broader trend common to the usage of eDNA tools. In terrestrial ecosystems, eDNA research has mostly focussed on the use of eDNA metabarcoding to characterise biodiversity, rather than targeting biosecurity threats or non-native populations. We discuss how eDNA-based methods are being applied to terrestrial ecosystems for biosecurity and managing non-native populations at each phase of the invasion continuum: transport, introduction, establishment, and spread; across different management options: containment, control, and eradication; and for detecting the impact of non-native organisms. Finally, we address some of the current technical issues and caveats of eDNA-based methods, particularly for terrestrial ecosystems, and how these might be solved. As eDNA-based methods improve, they will play an increasingly important role in the early detection and adaptive management of biological invasions, and the implementation of effective biosecurity controls.

Intraspecific leaf trait variation mediates edge effects on litter decomposition rate in fragmented forests

There is strong trait dependence in species-level responses to environmental change and their cascading effects on ecosystem functioning. However, there is little understanding of whether intraspecific trait variation (ITV) can also be an important mechanism mediating environmental effects on ecosystem functioning. This is surprising, given that global change processes such as habitat fragmentation and the creation of forest edges drive strong trait shifts within species. On 20 islands in the Thousand Island Lake, China, we quantified intraspecific leaf trait shifts of a widely distributed shrub species, Vaccinium carlesii, in response to habitat fragmentation. Using a reciprocal transplant decomposition experiment between forest edge and interior on 11 islands with varying areas, we disentangled the relative effects of intraspecific leaf trait variation versus altered environmental conditions on leaf decomposition rates in forest fragments. We found strong intraspecific variation in leaf traits in response to edge effects, with a shift toward recalcitrant leaves with low specific leaf area and high leaf dry matter content from forest interior to the edge. Using structural equation modeling, we showed that such intraspecific leaf trait response to habitat fragmentation had translated into significant plant afterlife effects on leaf decomposition, leading to decreased leaf decomposition rates from the forest interior to the edge. Importantly, the effects of intraspecific leaf trait variation were additive to and stronger than the effects from local environmental changes due to edge effects and habitat loss. Our experiment provides the first quantitative study showing that intraspecific leaf trait response to edge effects is an important driver of the decrease in leaf decomposition rate in fragmented forests. By extending the trait-based response-effect framework toward the individual level, intraspecific variation in leaf economics traits can provide the missing functional link between environmental change and ecological processes. These findings suggest an important area for future research on incorporating ITV to understand and predict changes in ecosystem functioning in the context of global change.

Complex battlefields favor strong soldiers over large armies in social animal warfare

In social animals, success can depend on the outcome of group battles. Theoretical models of warfare predict that group fighting ability is proportional to two key factors: the strength of each soldier in the group and group size. The relative importance of these factors is predicted to vary across environments [F. W. Lanchester, Aircraft in Warfare, the Dawn of the Fourth Arm (1916)]. Here, we provide an empirical validation of the theoretical prediction that open environments should favor superior numbers, whereas complex environments should favor stronger soldiers [R. N. Franks, L. W. Partridge, Anim. Behav. 45, 197-199 (1993)]. We first demonstrate this pattern using simulated battles between relatively strong and weak soldiers in a computer-driven algorithm. We then validate this result in real animals using an ant model system: In battles in which the number of strong native meat ant Iridomyrmex purpureus workers is constant while the number of weak non-native invasive Argentine ant Linepithema humile workers increases across treatments, fatalities of I. purpureus are lower in complex than in simple arenas. Our results provide controlled experimental evidence that investing in stronger soldiers is more effective in complex environments. This is a significant advance in the empirical study of nonhuman warfare and is important for understanding the competitive balance among native and non-native invasive ant species.

Genomics reveals the history of a complex plant invasion and improves the management of a biological invasion from the South African-Australian biotic exchange

Many plants exchanged in the global redistribution of species in the last 200 years, particularly between South Africa and Australia, have become threatening invasive species in their introduced range. Refining our understanding of the genetic diversity and population structure of native and alien populations, introduction pathways, propagule pressure, naturalization, and initial spread, can transform the effectiveness of management and prevention of further introductions. We used 20,221 single nucleotide polymorphisms to reconstruct the invasion of a coastal shrub, Chrysanthemoides monilifera ssp. rotundata (bitou bush) from South Africa, into eastern Australia (EAU), and Western Australia (WAU). We determined genetic diversity and population structure across the native and introduced ranges and compared hypothesized invasion scenarios using Bayesian modeling. We detected considerable genetic structure in the native range, as well as differentiation between populations in the native and introduced range. Phylogenetic analysis showed the introduced samples to be most closely related to the southern‐most native populations, although Bayesian analysis inferred introduction from a ghost population. We detected strong genetic bottlenecks during the founding of both the EAU and WAU populations. It is likely that the WAU population was introduced from EAU, possibly involving an unsampled ghost population. The number of private alleles and polymorphic SNPs successively decreased from South Africa to EAU to WAU, although heterozygosity remained high. That bitou bush remains an invasion threat in EAU, despite reduced genetic diversity, provides a cautionary biosecurity message regarding the risk of introduction of potentially invasive species via shipping routes.

Revealing the Introduction History and Phylogenetic Relationships of Passiflora foetida sensu lato in Australia

Genomic analysis can be a valuable tool to assistmanagement of non-native invasive species, through determining source and number of introductions as well as clarifying phylogenetic relationships. Here, we used whole chloroplast sequencing to investigate the introduction history of Passiflora foetida sensu lato in Australia and clarify its relationship with other Passiflora species present. Phylogenetic analysis of chloroplast genome data identified three separate genetic lineages of P. foetida s. l. present in Australia, indicating multiple introductions. These lineages had affinities to samples from three separate areas within the native range in Central and South America that represented phylogenetically distinct lineages. These results provide a basis for a targeted search of the native range of P. foetida s. l. for candidate biological control agents that have co-evolved with this species and are thus better adapted to the lineages that are present in Australia. Results also indicated that the Passiflora species native to Australia are in a separate clade to that of P. foetida s. l. and other introduced Passiflora species cultivated in Australia. This knowledge is important to assess the likelihood of finding biological control agents for P. foetida s. l. that will be sufficiently host-specific for introduction in Australia. As P. foetida s. l. is a widespread non-native invasive species across many regions of the world, outcomes from this work highlight the importance of first evaluating the specific entities present in a country before the initiation of a biological control program.

Disentangling biotic and abiotic drivers of intraspecific trait variation in woody plant seedlings at forest edges

In fragmented forests, edge effects can drive intraspecific variation in seedling performance that influences forest regeneration and plant composition. However, few studies have attempted to disentangle the relative biotic and abiotic drivers of intraspecific variation in seedling performance. In this study, we carried out a seedling transplant experiment with a factorial experimental design on three land-bridge islands in the Thousand Island Lake, China, using four common native woody plant species. At different distances from the forest edge (2, 8, 32, 128 m), we transplanted four seedlings of each species into each of three cages: full-cage, for herbivore exclusion; half-cage, that allowed herbivore access but controlled for caging artifacts; and no-cage control. In the 576 cages, we recorded branch architecture, leaf traits, and seedling survival for each seedling before and after the experimental treatment. Overall, after one full growing season, edge-induced abiotic drivers and varied herbivory pressure led to intraspecific variation in seedling performance, including trade-offs in seedling architecture and resource-use strategies. However, responses varied across species with different life-history strategies and depended on the driver in question, such that the abiotic and biotic effects were additive across species, rather than interactive. Edge-induced abiotic variation modified seedling architecture of a shade-tolerant species, leading to more vertical rather than lateral growth at edges. Meanwhile, increased herbivory pressure resulted in a shift toward lower dry matter investment in leaves of a light-demanding species. Our results suggest that edge effects can drive rapid directional shifts in the performance and intraspecific traits of some woody plants from early ontogenetic stages, but most species in this study showed negligible phenotypic responses to edge effects. Moreover, species-specific responses suggest the importance of interspecific differences modulating the degree of trait plasticity, implying the need to incorporate individual-level responses when understanding the impact of forest fragmentation on plant communities.

Global change impacts on arid zone ecosystems: Seedling establishment processes are threatened by temperature and water stress

Recruitment for many arid-zone plant species is expected to be impacted by the projected increase in soil temperature and prolonged droughts associated with global climate change. As seed dormancy is considered a strategy to avoid unfavorable conditions, understanding the mechanisms underpinning vulnerability to these factors is critical for plant recruitment in intact communities, as well as for restoration efforts in arid ecosystems. This study determined the effects of temperature and water stress on recruitment processes in six grass species in the genus Triodia R.Br. from the Australian arid zone. Experiments in controlled environments were conducted on dormant and less-dormant seeds at constant temperatures of 25°C, 30°C, 35°C, and 40°C, under well-watered (Ψsoil = -0.15 MPa) and water-limited (Ψsoil = -0.35 MPa) conditions. Success at three key recruitment stages-seed germination, emergence, and survival-and final seed viability of ungerminated seeds was assessed. For all species, less-dormant seeds germinated to higher proportions under all conditions; however, subsequent seedling emergence and survival were higher in the more dormant seed treatment. An increase in temperature (35-40°C) under water-limited conditions caused 95%-100% recruitment failure, regardless of the dormancy state. Ungerminated seeds maintained viability in dry soil; however, when exposed to warm (30-40°C) and well-watered conditions, loss of viability was greater from the less-dormant seeds across all species. This work demonstrates that the transition from seed to established seedling is highly vulnerable to microclimatic constraints and represents a critical filter for plant recruitment in the arid zone. As we demonstrate temperature and water stress-driven mortality between seeds and established seedlings, understanding how these factors influence recruitment in other arid-zone species should be a high priority consideration for management actions to mitigate the impacts of global change on ecosystem resilience. The knowledge gained from these outcomes must be actively incorporated into restoration initiatives.

Long term monitoring of recruitment dynamics determines eradication feasibility for an introduced coastal weed

Bitou bush (Chrysanthemoides monilifera subsp. rotundata) is a Weed of National Significance in Australia and has impacted a significant portion of the eastern coastline. Its discovery in Western Australia was, therefore, a cause for concern. Assessment and control of the isolated and well-defined population began in 2012. To assess the feasibility of eradication in Western Australia as a management outcome for bitou bush, we applied a rigorous data-driven quantification and prediction process to the control program. Between 2012 and 2018 we surveyed over 253 ha of land and removed 1766 bitou bush plants. Approximately 97 person-days were spent over the six years of survey. We measured the seed bank viability for five years starting in 2013, with the 2017 survey results indicating a decline of mean viable seeds/m2 from 39.3 ± 11.4 to 5.7 ± 2.2. In 2018 we found only ten plants and no newly recruited seedlings in the population. No spread to other areas has been recorded. Soil core studies indicate that the soil seed bank is unlikely to persist beyond eight years. Eradication of the population in Western Australia, defined as five years without plants being detected, therefore remains a realistic management goal. The information generated from the documentation of this eradication program provides invaluable insight for weed eradication attempts more generally: novel detection methods can be effective in making surveys more efficient, all survey methods are not entirely accurate and large plants can escape detection, bitou bush seeds persist in the soil but become effectively undetectable at low densities, and migration of seed was unquantifiable, possibly compromising delimitation. Continued monitoring of the Western Australian population will determine how much of a risk these factors represent to eradication as the outcome of this management program.

Invasion trajectory of alien trees: the role of introduction pathway and planting history

Global change is driving a massive rearrangement of the world's biota. Trajectories of distributional shifts are shaped by species traits, the recipient environment and driving forces with many of the driving forces directly due to human activities. The relative importance of each in determining the distributions of introduced species is poorly understood. We consider 11 Australian Acacia species introduced to South Africa for different reasons (commercial forestry, dune stabilization and ornamentation) to determine how features of the introduction pathway have shaped their invasion history. Projections from species distribution models (SDMs) were developed to assess how the reason for introduction influences the similarity between climatic envelopes in native and alien ranges. A lattice model for an idealized invasion was developed to assess the relative contribution of intrinsic traits and introduction dynamics on the abundance and extent over the course of simulated invasions. SDMs show that alien populations of ornamental species in South Africa occupy substantially different climate space from their native ranges, whereas species introduced for forestry occupy a similar climate space in native and introduced ranges. This may partly explain the slow spread rates observed for some alien ornamental plants. Such mismatches are likely to become less pronounced with the current drive towards 'eco gardens' resulting in more introductions of ornamental species with a close climate match between native and newly introduced regions. The results from the lattice model showed that the conditions associated with the introduction pathway (especially introduction pressure) dominate early invasion dynamics. The placement of introduction foci in urban areas limited the extent and abundance of invasive populations. Features of introduction events appear to initially mask the influence of intrinsic species traits on invasions and help to explain the relative success of species introduced for different purposes. Introduction dynamics therefore can have long-lasting influences on the outcomes of species redistributions, and must be explicitly considered in management plans.

Histologic evaluation of the depth of necrosis produced by argon beam coagulation: implications for use as adjuvant treatment of bone tumors

Argon beam coagulation (ABC) has been advocated as adjuvant treatment after curettage of aggressive benign bone tumors. This study was done to evaluate the depth of necrosis in cancellous bone treated with ABC. A 6-month-old pig was sacrificed and 20 1.5-cm cortical windows were created in the metaphyseal areas of the humeri, femora, and tibiae, exposing the underlying cancellous bone. The defects were randomly assigned to four groups: A, control; B, ABC at 50 W; C, 100 W; and D, 150 W. Histologic evaluation determined the depth of necrosis at each setting: A, 0.1 +/- 0.1 mm; B, 1.0 +/- 0.5 mm; C, 2.9 +/- 1.0 mm; and D, 4.2 +/- 0.7 mm. There were statistically significant differences between each of the experimental groups and the control (p < .0001), between groups B and C (p < .0001), and groups C and D (p = .0002).

Multilevel bilateral calcified thoracic spinal synovial cysts

Synovial cysts of the thoracic spine are quite rare. Bilateral presentation is even less frequent, and to the authors' knowledge multilevel occurrence and consistent calcification have not been reported so far. The pathogenesis of these cysts is unknown and their histological features have not been studied. They may be overlooked as the cause of myelopathy. The authors report a series of 4 cases of bilateral, multilevel, consistently calcified thoracic synovial cysts. The details of clinical, radiological, and histological findings are presented, along with a review of the literature, and a hypothesis on the pathogenesis of these lesions is formulated based on results of the clinical and pathological studies performed in these patients.

Intra-plant variation in cyanogenesis and the continuum of foliar plant defense traits in the rainforest tree Ryparosa kurrangii (Achariaceae)

At the intra-plant level, temporal and spatial variations in plant defense traits can be influenced by resource requirements, defensive priorities and storage opportunities. Across a leaf age gradient, cyanogenic glycoside concentrations in the rainforest understory tree Ryparosa kurrangii B.L. Webber were higher in young expanding leaves than in mature leaves (2.58 and 1.38 mg g(-1), respectively). Moreover, cyanogens, as an effective chemical defense against generalist herbivores, contributed to a defense continuum protecting foliar tissue during leaf development. Chemical (cyanogens and phenolic compounds) and phenological (delayed greening) defense traits protected young leaves, whereas mature leaves were largely protected by physical defense mechanisms (lamina toughness; explained primarily by leaf mass per area). Cyanogen concentration was considerably higher in floral tissue than in foliar tissue and decreased in floral tissue during development. Across contrasting tropical seasons, foliar cyanogenic concentration varied significantly, being highest in the late wet season and lowest during the pre-wet season, the latter coinciding with fruiting and leaf flushing. Cyanogens in R. kurrangii appear to be differentially allocated in a way that maximizes plant fitness but may also act as a store of reduced nitrogen that is remobilized during flowering and leaf flushing.

Constitutive polymorphic cyanogenesis in the Australian rainforest tree, Ryparosa kurrangii (Achariaceae)

Cyanogenesis, the liberation of volatile hydrogen cyanide from endogenous cyanide-containing compounds, is a proven plant defence mechanism and the particular cyanogens involved have taxonomic utility. The cyclopentenoncyanhydrin glycoside gynocardin was the only cyanogen isolated from foliar tissue of the rare Australian rainforest tree, Ryparosa kurrangii (Achariaceae). Mechanical damage simulating foliar herbivory did not induce a significant increase in the expression of cyanogenesis over a 24h period, indicating cyanogenic herbivore defence in R. kurrangii is constitutive. The cyanogenic potential of mature leaves was quantitatively polymorphic between trees in a natural population, ranging from 0.54 to 4.77 mg CN g(-1) dry wt leaf tissue.

Myrmecophilic food body production in the understorey tree, Ryparosa kurrangii (Achariaceae), a rare Australian rainforest taxon

Plant food bodies are rarely observed in the field, because of continual harvesting, and are often first documented on isolated glasshouse plants. Little is known about the genus Ryparosa (Achariaceae), and the appearance of outgrowths on leaves and stems of glasshouse-raised R. kurrangii seedlings suggested that the species may produce food bodies. Detailed macroimaging and histological techniques were used to characterize chemomorphological variation in food body material gathered from glasshouse plants. Two distinct types of food body were observed. Multicellular pearl bodies derived from epidermal and mesophyll tissue were produced on young leaves and stems, and contained lipids and glycogen-like carbohydrates. A unique form of lipid-rich multicellular food body that 'opens' during development was found exclusively on mature plant tissue. A filament network was associated with food body lipid droplets. This is the first detailed documentation of food body production in an understorey genus adapted to low light conditions. We suggest that the distinctive spatial deployment of Ryparosa food rewards, and the ants attracted to them, may be invaluable for keeping long-lived leaves free from epiphyllous communities.

Intraneural perineurioma of the third cranial nerve: occurrence and identification

✓Intraneural perineurioma is a true but rare neoplasm that originates from perineurial cells and mainly affects peripheral nerves. It must be distinguished from other hypertrophic neuropathies that are either inflammatory or demonstrate an onion-bulb formation that originates from Schwann cells. Complying with this strict definition, only three additional cases of cranium-related perineurioma have been identified: two lesions arose extracranially and involved cranial nerves, and one occurred intracranially but did not involve a nerve.

The authors describe a 27-year-old woman who presented with left third cranial nerve palsy and was found to harbor a mass lesion in the superior orbital fissure and cavernous sinus. After subtotal resection had been performed, pathological studies confirmed the presence of perineurial tumor cells in a pseudo–onion bulb formation. The cells stained positively for epithelial membrane antigen but not for S100 protein, clearly distinguishing the disease from one that originates in Schwann cells.

Part-of relations in anatomy ontologies: a proposal for RDFS and OWL formalisations

Part-of relations are central to anatomy. However, the definition, formalisation and use of part-of in anatomy ontologies is problematic. This paper surveys existing formal approaches, as well as the use of part-of in the Open Biological Ontologies (OBO) anatomies of model species. Based on this analysis, we propose a minimal ontology for anatomy which is expressed in the Semantic Web languages RDFS and OWL-Full. The paper concludes with a description of the context of this work in capturing cross-species tissue homologies and analogies.

Cassowary frugivory, seed defleshing and fruit fly infestation influence the transition from seed to seedling in the rare Australian rainforest tree, Ryparosa sp. nov. 1 (Achariaceae)

The rare Australian rainforest tree Ryparosa sp. nov. 1 aff. javanica (sensu Webber & Curtis, BW-017; Achariaceae) has large fleshy fruits that undergo a distinctive colour change during ripening. Fruit seem highly suited to frugivore interactions with large ground-dwelling avian or marsupial frugivores, a role primarily filled by the endangered cassowary. We found that fruits had chemical defence traits that closely paralleled morphological ripening signals. Young fruit seeds had amongst the highest concentrations of plant tissue cyanogens ever recorded (some in excess of 12 mg g^-1 dw), yet the flesh of ripe fruits had negligible cyanogen defence. A seed treatment trial found that cassowary gut passage significantly improved germination from 4% to 92%, and we were not able to replicate this result with simulated treatments. While high levels of fruit fly larval infestation accounted for reduced seed viability, this predation was apparently reduced by cassowary gut passage. Post-germination seedling traits such as haustorial cryptocotylar cotyledons and epigeal germination may increase the chance of survival for establishing seedlings. We conclude that the range of traits seen in Ryparosa recruitment is particularly suited to interactions with frugivores and survival in a rainforest ecosystem.

An objective analysis of process errors in trauma resuscitations

OBJECTIVE

A computer-based system to apply trauma resuscitation protocols to patients with penetrating thoracoabdominal trauma was previously validated for 97 consecutive patients at a Level 1 trauma center by a panel of the trauma attendings and further refined by a panel of national trauma experts. The purpose of this article is to describe how this system is now used to objectively critique the actual care given to those patients for process errors in reasoning, independent of outcome.

METHODS

A chronological narrative of the care of each patient was presented to the computer program. The actual care was compared with the validated computer protocols at each decision point and differences were classified by a predetermined scoring system from 0 to 100, based on the potential impact on outcome, as critical/noncritical/no errors of commission, omission, or procedure selection.

RESULTS

Errors in reasoning occurred in 100% of the 97 cases studied, averaging 11.9/case. Errors of omission were more prevalent than errors of commission (2. 4 errors/case vs 1.2) and were of greater severity (19.4/error vs 5. 1). The largest number of errors involved the failure to record, and perhaps observe, beside information relevant to the reasoning process, an average of 7.4 missing items/patient. Only 2 of the 10 adverse outcomes were judged to be potentially related to errors of reasoning.

CONCLUSIONS

Process errors in reasoning were ubiquitous, occurring in every case, although they were infrequently judged to be potentially related to an adverse outcome. Errors of omission were assessed to be more severe. The most common error was failure to consider, or document, available relevant information in the selection of appropriate care.

Natural language generation in health care

Good communication is vital in health care, both among health care professionals, and between health care professionals and their patients. And well-written documents, describing and/or explaining the information in structured databases may be easier to comprehend, more edifying, and even more convincing than the structured data, even when presented in tabular or graphic form. Documents may be automatically generated from structured data, using techniques from the field of natural language generation. These techniques are concerned with how the content, organization and language used in a document can be dynamically selected, depending on the audience and context. They have been used to generate health education materials, explanations and critiques in decision support systems, and medical reports and progress notes.

Undifferentiated sarcomas of children: pathology and clinical behavior--an Intergroup Rhabdomyosarcoma study

Undifferentiated soft tissue sarcoma (UND-STS) is the most poorly defined tumor eligible for intergroup Rhabdomyosarcoma Studies (IRS). Recent IRS UND-STS experience was reviewed to assess the histologic characteristics and clinical behavior of undifferentiated sarcomas. Of the 1,527 patients entered on IRS-III and IRS pilot-IV, 96 had tumors classified by the IRS Pathology Committee as UND-STS. Of these, 52 had adequate histologic material for this study. After application of immunohistochemistry, 18 tumors were reclassified, mostly as embryonal rhabdomyosarcomas (RMS), primitive neuroectodermal tumors, and intraabdominal desmoplastic small found cell tumors. The remaining 34 UND-STS had a diffuse hypercellular histologic pattern made up of sheets of medium-sized cells. The tumor cells had a minimal to moderate amount of cytoplasm and a variable nuclear morphology, predominately vesicular with finely granular chromatin. Except for reactivity with antibodies against vimentin, most tumors had a negative immunohistochemical profile. The 5 year Kaplan-Meier survival estimate for patients with non-metastatic disease was 72%, a significant improvement when contrasted with patients diagnosed to have UND-STS in IRS-I and IRS-II.

On-line quality [corrected] assurance in the initial definitive management of multiple trauma: evaluating system potential

The TraumAID system has been designed to provide on-line decision support throughout the initial definitive management of injured patients. Here we describe its retrospective evaluation and the use we subsequently made of judges comments on the validation data to evaluate TraumaTIQ, a new critiquing interface for TraumAID, investigating the question of whether, with timely recording of information, a system could produce commentary in line with that of human experts. Our results show that (1) comparable commentary can be produced, and (2) validation studies, which take great time and effort to conduct, can produce useful data beyond their original design goals.

Simulated casualties and medics for emergency training

The MediSim system extends virtual environment technology to allow medical personnel to interact with and train on simulated casualties. The casualty model employs a three-dimensional animated human body that displays appropriate physical and behavioral responses to injury and/or treatment. Medical corpsmen behaviors were developed to allow the actions of simulated medical personnel to conform to both military practice and medical protocols during patient assessment and stabilization. A trainee may initiate medic actions through a mouse and menu interface; a VR interface has also been created by Stansfield's research group at Sandia National Labs.

Herpes virus-like sequences are specifically found in Kaposi sarcoma lesions

AIM

To detect the prevalence of herpes virus-like DNA sequences in AIDS associated Kaposi sarcoma (KSHV) lesions and normal tissue.

METHODS

KSHV detection was performed by polymerase chain reaction (PCR) using four different sets of primers. PCR products were cloned, sequenced, and analysed.

RESULTS

All of four biopsies of Kaposi sarcoma lesions and all of three paraffin embedded Kaposi sarcoma tissues were positive for KSHV, while normal tissue from the same patients was negative. Sequence analysis of amplification products revealed polymorphisms that result in amino acid changes of the predicted sequence.

CONCLUSIONS

KSHV is prevalent in tissues from Kaposi sarcoma, suggesting a role in the development of the tumour. On this basis, anti-herpes virus agents should be considered to control Kaposi sarcoma.

Casualty modeling for real-time medical training

We present a model for simulating casualties in virtual environments for real-time medical training. It allows a user to choose diagnostic and therapeutic actions to carry out on a simulated casualty who will manifest appropriate physiological, behavioral, and physical responses. Currently, the user or a "stealth instructor" can specify one or more injuries that the casualty has sustained. The model responds by continuously determining the state of the casualty, responding appropriately to medical assessment and treatment procedures. So far, we have modeled four medical conditions and over 20 procedures. The model has been designed to handle the addition of other injuries and medical procedures.

Classification of rhabdomyosarcomas and related sarcomas. Pathologic aspects and proposal for a new classification--an Intergroup Rhabdomyosarcoma Study

BACKGROUND

There is a need to develop a single prognostically significant classification of rhabdomyosarcomas (RMS) and other related tumors of children, adolescents, and young adults which would be a current guide for their diagnosis, allow valid comparison of outcomes between protocols carried out anywhere in the world, and should enhance recognition of prognostic subsets.

METHOD

Sixteen pathologists from eight pathology groups, representing six countries and several cooperative groups, classified by four histopathologic classification schemes 800 representative tumors of the 999 eligible cases treated on Intergroup Rhabdomyosarcoma Study II. Each tumor was classified according to each of the four systems by each of the pathologists. In addition, two independent subsamples of 200 of the 800 patients were reviewed according to the new system, so that 343 distinct patients were reviewed once, and 57 of these twice.

RESULTS

A study of the survival rates of all subtypes in the sample of 800 patients led to the formation of a new system. This was tested on two independent subsets of 200 of the original cases and found to be reproducible and predictive of outcome by univariate analysis. A multivariate analysis of the 343 patients classified according to the new system indicated that a survival model including pathologic classification and known prognostic factors of primary site, clinical group, and tumor size was significantly better at predicting survival than a model with only the known prognostic factors.

CONCLUSION

This new classification, termed International Classification of Rhabdomyosarcoma (ICR) by the authors, was reproducible and predictive of outcome among patients with differing histologies treated uniformly on the Intergroup Rhabdomyosarcoma II protocols. We believe it should be utilized by all pathologists and cooperative groups to classify rhabdomyosarcomas in order to provide comparability among and within multi-institutional studies.

Nonrhabdomyosarcomatous soft tissue sarcomas of childhood: formulation of a simplified system for grading

Because of the rarity of pediatric nonrhabdomyosarcomatous soft tissue sarcomas, it is difficult to test standardized treatment protocols for individual tumor entities. Grading has been used successfully to predict outcome of adult sarcomas, but pediatric soft tissue tumors display a notable difference in clinical behavior when compared to older patients. To test systematically a standardized treatment strategy for pediatric nonrhabdomyosarcomastous soft tissue sarcomas devised by the Pediatric Oncology Group, the authors devised a grading schema using concepts of adult grading systems and integrating the unique clinical and morphologic features of pediatric sarcomas. Three grading tiers were devised: Grade I, which includes certain pediatric tumors with little propensity for malignancy; Grade II, which is composed of tumors excluded from Grades I or III by virtue of histologic diagnosis and having <5 mitoses/10 high-power fields or <15% geographic necrosis; and Grade III, which comprises certain tumors known to be clinically aggressive by virtue of histologic diagnosis and non-Grade I tumors with >4 mitoses/10 high-power fields or > 15% necrosis. An initial retrospective analysis on a series of lesions treated at a single institution indicated a strong predictive value for grading. Subsequent prospective studies by the Pediatric Oncology Group continue to verify the prognostic value of pediatric nonrhabdomyosarcomatous soft tissue sarcoma grading, and studies on individual pediatric nonrhabdomyosarcomatous soft tissue sarcomas, such as synovial sarcoma, also indicate the relatively poor outcome of higher grade lesions. Grade can be used to predict outcome of pediatric nonrhabdomyosarcomatous soft tissue sarcomas and to devise treatment strategies for experimental protocols.

Use of monoclonal antibody 1H1, anticortactin, to distinguish normal and neoplastic smooth muscle cells: comparison with anti-alpha-smooth muscle actin and antimuscle-specific actin

In preliminary experiments, we found that 1H1, a monoclonal antibody directed against the v-src substrate cortactin, reacts with smooth muscle, myoepithelium, myofibroblasts, and macrophages in formaldehyde-fixed human tissues. To evaluate the use of this antibody as a diagnostic reagent, we tested the immunohistochemical distribution of cortactin in 61 mesenchymal neoplasms, 11 neuroectodermal neoplasms, and eight embryonal epithelial neoplasms. The results were compared with those obtained using antibodies against alpha-smooth muscle actin and muscle-specific actin on a similar set of tissues. With the exception of positive staining in rhabdomyosarcoma, in this series only tumors with smooth muscle differentiation appeared to contain cortactin (16 of 19 leiomyosarcomas, one infantile fibrosarcoma, one malignant fibrous histiocytoma). Immunoelectron microscopy localized cortactin to the actin-associated dense bodies of the microfilament network. We conclude that cortactin may be a useful adjunct to alpha-smooth muscle actin and muscle-specific actin as a marker for the study and diagnosis of smooth muscle neoplasms and related lesions.

Multiplex RT-PCR assay for the differential diagnosis of alveolar rhabdomyosarcoma and Ewing's sarcoma

Cytogenetic analysis has defined specific translocations associated with two of the most common small round cell tumors of childhood, t(11;22) in Ewing's sarcoma and t(2;13) in alveolar rhabdomyosarcoma. We and others have previously demonstrated the diagnostic utility of a reverse transcriptase polymerase chain reaction (RT-PCR) assay for the detection of the t(11;22) encoded EWS/FLI-1 chimeric message in Ewing's sarcoma. More recently, we have cloned the t(2;13)(q35;q14) translocation and have shown that it results in the fusion of the PAX3 gene on chromosome 2 to FKHR, a novel member of the fork-head family of transcription factors on chromosome 13. To define the morphological spectrum of childhood sarcomas that express the t(2;13) encoded PAX3/FKHR chimeric message, we have performed RT-PCR analysis on samples from 44 primary pediatric sarcomas and 8 sarcoma cell lines. PAX3/FKHR chimeric messages were detected in 24 of 27 alveolar, 2 of 12 embryonal, and 0 of 1 pleomorphic rhabdomyosarcoma and in 1 of 2 ectomesenchymomas. In contrast, none of 8 Ewing's sarcomas or 2 undifferentiated sarcomas expressed this message. Chimeric transcripts were detected in all cases with cytogenetic evidence of the (2;13) translocation, and in each case the chimeric PAX3/FKHR message had the identical junction sequence, suggesting that genomic chromosome breaks were clustered in a single intron in both genes. By combining the PAX3/FKHR RT-PCR assay with primers for detection of the Ewing's sarcoma t(11;22) encoded EWS/FLI-1 chimeric transcript, we have developed a multiplex RT-PCR reaction that allows the rapid and accurate identification of either translocation in a biopsy sample.

Agreement among and within groups of pathologists in the classification of rhabdomyosarcoma and related childhood sarcomas. Report of an international study of four pathology classifications

BACKGROUND

An International Pathology study was conducted to measure the agreement demonstrated among and within groups of pathologists involved in the categorization of childhood rhabdomyosarcoma according to four pathology classifications. Data concerning agreement and survival experience according to patho-new subtypes were used as a basis for selection of a proposed new pathologic classification.

METHODS

A random sample of 800 eligible patients was chosen from the Intergroup Rhabdomyosarcoma Study II (IRS-II) and was reviewed by pathologists representing eight institutions. A 20% sample of the 800 patients was then reviewed by the pathologists to determine the level of agreement with their original classification. In each instance the patients were classified according to four pathology systems: the conventional system, the International Society for Pediatric Oncology system (SIOP), the National Cancer Institute (NCI) system, and the cytohistologic system.

RESULTS

Among the groups of pathologists, the highest measure of agreement was a Kappa value of K = 0.451 for the conventional system, followed by K = 0.406 for the SIOP system, K = 0.384 for the NCI system, and K = 0.328 for the cytohistologic system. For reproducibility within the groups of pathologists, the highest measure of agreement was K = 0.605 for the conventional system, followed by K = 0.579 for the NCI system, K = 0.573 for the SIOP system, and K = 0.508 for the cytohistologic system.

CONCLUSIONS

There was a general similarity between the agreement reached within the modified conventional, STOP, and NCI systems, with the modified conventional system having the highest Kappa values, and thus the highest measure of agreement, both among and within the groups of pathologists. Also, the subtypes of the conventional system demonstrated a highly significant relationship to survival time. Hence, based on criteria of reproducibilty and prognostic significance, the proposed classification will essentially be a modification of the conventional system with elements of the SIOP and NCI systems.

Solid alveolar rhabdomyosarcomas with the t(2;13). Report of two cases with diagnostic implications

Two patients having rhabdomyosarcomas with the recently described "solid variant" pattern of alveolar rhabdomyosarcoma are reported. Both tumors had aggressive cytologic features with monotonous sheets of round nuclei, but without fibrous septa, and both had been initially classified as embryonal rhabdomyosarcomas. Cytogenetic analyses of tumor explants from both cases revealed the t(2;13) chromosomal aberration typical of alveolar rhabdomyosarcoma. Both patients died of metastases, despite aggressive surgical and adjuvant therapy. This report represents the first karyotypic analyses of solid alveolar rhabdomyosarcomas and supports the inclusion of these tumors in the alveolar category despite the lack of fibrous septa.

Rhabdomyosarcoma. A new classification scheme related to prognosis

We classified 159 cases of rhabdomyosarcoma (RMS) according to the conventional scheme adopted by the World Health Organization and a modified conventional scheme established at the National Cancer Institute (NCI), Bethesda, Md. The major modification in the NCI scheme was the inclusion of compact round-cell RMS with scant myogenesis in the group of alveolar RMS despite lack of an alveolar architecture. These tumors were previously considered to be embryonal RMS, but their cytologic features are quite different from those seen in embryonal RMS and are indistinguishable from those encountered in alveolar RMS. These tumors are referred to as "solid alveolar RMS." Survival curves were constructed with the method of Kaplan-Meier and compared with the unstratified and stratified methods of Mantel-Haenszel (with stratification factors being stage, site, and age) and with the Cox regression analysis. Both histologic schemes showed a statistically significant prognostic value in unstratified analyses, but the NCI scheme demonstrated prognostic value even in stratified analyses and in the Cox regression analysis in our series of cases. The data indicate that the NCI scheme can serve as a highly predictive, independent prognostic factor in RMS and that the alveolar category should be expanded to include the solid round-cell RMS, even in the absence of a classic alveolar architecture.

Relationship of tumor-cell ploidy to histologic subtype and treatment outcome in children and adolescents with unresectable rhabdomyosarcoma

Clinical and histopathologic features are often inadequate for accurate prediction of relapse or survival of individual patients with rhabdomyosarcoma (RMS). We therefore studied the cellular DNA content (ploidy) of RMS cells in relation to histology and response to therapy in 37 patients with unresectable tumors. Using flow cytometric techniques, we found that about one third of patients had diploid tumor stem lines, regardless of the histologic subtype. In the group with abnormal ploidy, a hyperdiploid classification (1.10 to 1.80 times the DNA content of normal diploid cells) was exclusively associated with embryonal histology (P = .001). By contrast, near-tetraploidy (1.80 to 2.60 times the DNA content of normal cells) was strongly associated with alveolar histology (P = .001). Thus, in these histologic subtypes of RMS, abnormal ploidy appears to arise through different mechanisms. Tumor-cell ploidy had a significant impact on survival that was especially apparent in patients with unresectable, nonmetastatic (group III) tumors. In this subgroup, hyperdiploidy conferred the best prognosis and diploidy the worst (P less than .0001). None of the eight patients with diploid tumors survived for more than 18 months. Tumor-cell ploidy was the best predictor of treatment outcome for patients with either embryonal (P less than .001; relative risk, 25.5) or alveolar (P = .073; relative risk 7.1) RMS and contributed significantly after adjustment for disease stage and anatomic site. Patients with unresectable diploid RMS have an unacceptably high risk of treatment failure, justifying new therapeutic approaches for this distinct subgroup.