Perspectives for integrated insect pest protection in oilseed rape breeding

In the past, breeding for incorporation of insect pest resistance or tolerance into cultivars for use in integrated pest management schemes in oilseed rape/canola (Brassica napus) production has hardly ever been approached. This has been largely due to the broad availability of insecticides and the complexity of dealing with high-throughput phenotyping of insect performance and plant damage parameters. However, recent changes in the political framework in many countries demand future sustainable crop protection which makes breeding approaches for crop protection as a measure for pest insect control attractive again. At the same time, new camera-based tracking technologies, new knowledge-based genomic technologies and new scientific insights into the ecology of insect-Brassica interactions are becoming available. Here we discuss and prioritise promising breeding strategies and direct and indirect breeding targets, and their time-perspective for future realisation in integrated insect pest protection of oilseed rape. In conclusion, researchers and oilseed rape breeders can nowadays benefit from an array of new technologies which in combination will accelerate the development of improved oilseed rape cultivars with multiple insect pest resistances/tolerances in the near future.

Morphological and olfactory tree traits influence the susceptibility and suitability of the apple species Malus domestica and M. sylvestris to the florivorous weevil Anthonomus pomorum (Coleoptera: Curculionidae)

The florivorous apple blossom weevil, Anthonomus pomorum (Coleoptera: Curculionidae), is the most economically relevant insect pest of European apple orchards in early spring. Neither efficient monitoring nor ecologically sustainable management of this insect pest has yet been implemented. To identify heritable traits of apple trees that might influence the host selection of A. pomorum, we compared the susceptibility of apple tree species using infestation rates of the domesticated apple, Malus domestica (Rosaceae: Pyreae), and the European crab apple, M. sylvestris. We evaluated the suitability of the two apple species for A. pomorum by quantifying the mass of weevil offspring. Because volatile organic compounds (VOCs) emitted from flower buds of the domesticated apple have previously been suggested to mediate female weevil preference via olfactory cues, we conducted bioassay experiments with blossom buds of both apple species to explore the olfactory preference of adult weevils and, furthermore, identified the headspace VOCs of blossom buds of both apple species through GC-MS analysis. The infestation analysis showed that A. pomorum infested the native European crab apple more prevalently than the domesticated apple, which originated from Central Asia. The European crab apple also appeared to be better suited for weevil larval development than the domesticated apple, as weevils emerging from M. sylvestris had a higher body mass than those emerging from M. domestica. These field observations were supported by olfactory bioassays, which showed that A. pomorum significantly preferred the odor of M. sylvestris buds compared to the odor of M. domestica buds. The analysis of headspace VOCs indicated differences in the blossom bud volatiles separating several M. domestica individuals from M. sylvestris individuals. This knowledge might be employed in further studies to repel A. pomorum from M. domestica blossom buds.

Effects of temperature and soil fauna on the reduction and leaching of deoxynivalenol and zearalenone from Fusarium graminearum-infected maize stubbles

A microcosm study was conducted at two different temperatures under laboratory conditions to investigate the regulatory capacity and the interactive performance of two soil fauna species (Aporrectodea caliginosa, earthworms, and Proisotoma minuta, collembolans) on the reduction of Fusarium toxins in contaminated maize stubbles. Single and mixed species treatments were exposed to artificially infected maize stubbles highly contaminated with the mycotoxins deoxynivalenol (DON) (10,462 µg kg⁻¹) and zearalenone (ZEN) (2,780 µg kg⁻¹) at 17 °C and 25 °C for time periods of 3 and 6 weeks. Immediately after the respective end of incubation, the microcosms were heavily watered to determine the leaching potential of DON and ZEN from contaminated maize stubbles. Maize residues, soil, and eluted water (percolate) samples were analysed for mycotoxin content using liquid chromatography coupled to mass spectrometry. The biomass of introduced earthworms and number of collembolans were monitored to get information about their adaptability to the experimental conditions. While the decline of ZEN was temperature-dependent, but not influenced by faunal activities, a reduction of DON due to faunal impact was observed by trend. In the leaching experiment, 67–82% of the DON content in the residual maize stubbles leached from the plant material by irrigation and was detected in the soil (1.9–3.4 µg kg⁻¹) and in the percolate (12–295 µg L⁻¹). In the case of ZEN, 27–50% of the mycotoxin leached from the residual maize stubbles due to watering but was only occasionally detected in traces in the soil and not found in the percolate. The results clearly reveal a leaching potential of both DON and ZEN, respectively, but a mobilisation with water was only observed for DON. Temperature confirmed to be a key factor, affecting the fate of the mycotoxins in the soil by driving the interaction between different soil fauna members as well as functional and trophic levels within the soil food web.

Chemical defence in Brassicaceae against pollen beetles revealed by metabolomics and flower bud manipulation approaches

Divergence of chemical plant defence mechanisms within the Brassicaceae can be utilized to identify means against specialized pest insects. Using a bioassay-driven approach, we (a) screened 24 different Brassica napus cultivars, B. napus resyntheses and related brassicaceous species for natural plant resistance against feeding adults of the pollen beetle (Brassicogethes aeneus), (b) tested for gender-specific feeding resistance, (c) analysed the flower bud metabolomes by a non-targeted approach and (d) tested single candidate compounds for their antifeedant activity. (a) In no-choice assays, beetles were allowed to feed on intact plants. Reduced feeding activity was mainly observed on Sinapis alba and Barbarea vulgaris but not on B. napus cultivars. (b) Males fed less and discriminated more in feeding than females. (c) Correlation of the metabolite abundances with the beetles' feeding activity revealed several glucosinolates, phenylpropanoids, flavonoids and saponins as potential antifeedants. (d) These were tested in dual-bud-choice assays developed for medium-throughput compound screening. Application of standard compounds on single oilseed rape flower buds revealed highly deterrent effects of glucobarbarin, oleanolic acid and hederagenin. These results help to understand chemical plant defence in the Brassicaceae and are of key importance for further breeding strategies for insect-resistant oilseed rape cultivars.

Metabolomics Approaches for Analyzing Effects of Geographic and Environmental Factors on the Variation of Root Essential Oils of Ferula assa-foetida L

Environmental factors shape the production and accumulation processes of plant secondary metabolites in medical and aromatic plants and thus their pharmacological and biological activity. Using an environmental metabolomics approach, we determined chemotypes and specific compounds on the basis of essential oils (EOs) from roots of 10 Iranian Ferula assa-foetida L. populations and related them to geographical, climate, and edaphic data. GC-MS revealed three distinct chemotypes characterized by (I) monoterpenes and Z-1-propenyl sec-butyl disulfide; (II) eudesmane sesquiterpenoids and α-agarofuran; and (III) Z- and E-1-propenyl sec-butyl disulfide. NIRS measurements indicated a similar but less distinct pattern. Structural equation models showed that EO constituents and content were directly influenced by edaphic factors (texture, pH, and iron, potassium, and aluminum content) and temperature and predominantly indirectly by latitude, longitude, and altitude. Predicting EO constituents or chemotypes by geographical, climate, and soil factors can be used in F. assa-foetida to select populations with specific EO characteristics.

Variation of Secondary Metabolite Profile of Zataria multiflora Boiss. Populations Linked to Geographic, Climatic, and Edaphic Factors

Geographic location and connected environmental and edaphic factors like temperature, rainfall, soil type, and composition influence the presence and the total content of specific plant compounds as well as the presence of a certain chemotype. This study evaluated whether geographic, edaphic, and climatic information can be utilized to predict the presence of specific compounds from medicinal or aromatic plants. Furthermore, we tested rapid analytical methods based on near infrared spectroscopy (NIR) coupled with gas chromatography/flame ionization (GC/FID) and gas chromatography/mass spectrometry (GC/MS) analytical methods for characterization and classification metabolite profiling of Zataria multiflora Boiss. populations. Z. multiflora is an aromatic, perennial plant with interesting pharmacological and biological properties. It is widely dispersed in Iran as well as in Pakistan and Afghanistan. Here, we studied the effect of environmental factors on essential oil (EO) content and the composition and distribution of chemotypes. Our results indicate that this species grows predominantly in areas rich in calcium, iron, potassium, and aluminum, with mean rainfall of 40.46 to 302.72 mm·year^-1 and mean annual temperature of 14.90°C to 28.80°C. EO content ranged from 2.75% to 5.89%. Carvacrol (10.56-73.31%), thymol (3.51-48.12%), linalool (0.90-55.38%), and p-cymene (1.66-13.96%) were the major constituents, which classified 14 populations into three chemotypes. Corresponding to the phytochemical cluster analysis, the hierarchical cluster analysis (HCA) based on NIR data also recognized the carvacrol, thymol, and linalool chemotypes. Hence, NIR has the potential to be applied as a useful tool to determine rapidly the chemotypes of Z. multiflora and similar herbs. EO and EO constituent content correlated with different geographic location, climate, and edaphic factors. The structural equation models (SEMs) approach revealed direct effects of soil factors (texture, phosphor, pH) and mostly indirect effects of latitude and altitude directly affecting, e.g., soil factors. Our approach of identifying environmental predictors for EO content, chemotype or presence of high amounts of specific compounds can help to select regions for sampling plant material with the desired chemical profile for direct use or for breeding.

Elm leaves 'warned' by insect egg deposition reduce survival of hatching larvae by a shift in their quantitative leaf metabolite pattern

Plants may take insect eggs on their leaves as a warning of future herbivory and intensify their defence against feeding larvae. Responsible agents are, however, largely unknown, and little knowledge is available on this phenomenon in perennial plants. We investigated how egg deposition affects the anti-herbivore defence of elm against the multivoltine elm leaf beetle. Prior egg deposition caused changes in the quality of feeding-damaged leaves that resulted in increased larval mortality and reduced reproductive capacity of the herbivore by harming especially female larvae. Chemical analyses of primary and secondary leaf metabolites in feeding-damaged, egg-free (F) and feeding-damaged, egg-deposited (EF)-leaves revealed only small differences in concentrations when comparing metabolites singly. However, a pattern-focused analysis showed clearly separable patterns of (F) and (EF)-leaves because of concentration differences in especially nitrogen and phenolics, of which robinin was consumed in greater amounts by larvae on (EF) than on (F)-leaves. Our study shows that insect egg deposition mediates a shift in the quantitative nutritional pattern of feeding-damaged leaves, and thus might limit the herbivore's population growth by reducing the number of especially female herbivores. This may be a strategy that pays off in a long run particularly in perennial plants against multivoltine herbivores.

Chemical ecology and evolution of plant-insect interactions: a multitrophic perspective

Gaining a better understanding of infochemical-mediated host plant/host location behaviour of herbivores and their natural enemies in complex and heterogeneous chemical environments provides a multitrophic perspective on the chemical ecology and evolution of plant-insect interactions. Here I focus on the sources of chemical complexity formed primarily by both host and non-host plants in their interaction with higher trophic levels and on the effect of this complexity on herbivores and their natural enemies. Future research should define the patterns and processes involved in these interactions, which are often complex, dynamic and intricately unique. Studying multitrophic interactions under more realistic conditions will help to identify mechanisms with evolutionary potential and patterns that can be used in biological control practice.

Phenotypic plasticity in a willow leaf beetle depends on host plant species: release and recognition of beetle odors

Aggregation behavior of herbivorous insects is mediated by a wide range of biotic and abiotic factors. It has been suggested that aggregation behavior of the blue willow leaf beetle Phratora vulgatissima is mediated by both host plant odor and by odor released by the beetles. Previous studies show that the beetles respond to plant odors according to their prior host plant experiences. Here, we analyzed the effect of the host plant species on odor released and perceived by adult P. vulgatissima. The major difference between the odor of beetles feeding on salicin-rich and salicin-poor host plants was the presence of salicylaldehyde in the odor of the former, where both males and females released this compound. Electrophysiological studies showed that the intensity of responses to single components of odor released by beetles was sex specific and dependent on the host plant species with which the beetles were fed. Finally, behavioral studies revealed that males feeding on salicin-rich willows were attracted by salicylaldehyde, whereas females did not respond behaviorally to this compound, despite showing clear antennal responses to it. Finally, the ecological relevance of the influence of a host plant species on the plasticity of beetle odor chemistry, perception, and behavior is discussed.

Choosing and using diversity indices: insights for ecological applications from the German Biodiversity Exploratories

Biodiversity, a multidimensional property of natural systems, is difficult to quantify partly because of the multitude of indices proposed for this purpose. Indices aim to describe general properties of communities that allow us to compare different regions, taxa, and trophic levels. Therefore, they are of fundamental importance for environmental monitoring and conservation, although there is no consensus about which indices are more appropriate and informative. We tested several common diversity indices in a range of simple to complex statistical analyses in order to determine whether some were better suited for certain analyses than others. We used data collected around the focal plant Plantago lanceolata on 60 temperate grassland plots embedded in an agricultural landscape to explore relationships between the common diversity indices of species richness (S), Shannon's diversity (H'), Simpson's diversity (D1), Simpson's dominance (D2), Simpson's evenness (E), and Berger-Parker dominance (BP). We calculated each of these indices for herbaceous plants, arbuscular mycorrhizal fungi, aboveground arthropods, belowground insect larvae, and P. lanceolata molecular and chemical diversity. Including these trait-based measures of diversity allowed us to test whether or not they behaved similarly to the better studied species diversity. We used path analysis to determine whether compound indices detected more relationships between diversities of different organisms and traits than more basic indices. In the path models, more paths were significant when using H', even though all models except that with E were equally reliable. This demonstrates that while common diversity indices may appear interchangeable in simple analyses, when considering complex interactions, the choice of index can profoundly alter the interpretation of results. Data mining in order to identify the index producing the most significant results should be avoided, but simultaneously considering analyses using multiple indices can provide greater insight into the interactions in a system.

EU-OPENSCREEN-chemical tools for the study of plant biology and resistance mechanisms

EU-OPENSCREEN is an academic research infrastructure initiative in Europe for enabling researchers in all life sciences to take advantage of chemical biology approaches to their projects. In a collaborative effort of national networks in 16 European countries, EU-OPENSCREEN will develop novel chemical compounds with external users to address questions in, among other fields, systems and network biology (directed and selective perturbation of signalling pathways), structural biology (compound-target interactions at atomic resolution), pharmacology (early drug discovery and toxicology) and plant biology (response of wild or crop plants to environmental and agricultural substances). EU-OPENSCREEN supports all stages of a tool development project, including assay adaptation, high-throughput screening and chemical optimisation of the 'hit' compounds. All tool compounds and data will be made available to the scientific community. EU-OPENSCREEN integrates high-capacity screening platforms throughout Europe, which share a rationally selected compound collection comprising up to 300,000 (commercial and proprietary compounds collected from European chemists). By testing systematically this chemical collection in hundreds of assays originating from very different biological themes, the screening process generates enormous amounts of information about the biological activities of the substances and thereby steadily enriches our understanding of how and where they act.

Habitats as complex odour environments: how does plant diversity affect herbivore and parasitoid orientation?

Plant diversity is known to affect success of host location by pest insects, but its effect on olfactory orientation of non-pest insect species has hardly been addressed. First, we tested in laboratory experiments the hypothesis that non-host plants, which increase odour complexity in habitats, affect the host location ability of herbivores and parasitoids. Furthermore, we recorded field data of plant diversity in addition to herbivore and parasitoid abundance at 77 grassland sites in three different regions in Germany in order to elucidate whether our laboratory results reflect the field situation. As a model system we used the herb Plantago lanceolata, the herbivorous weevil Mecinus pascuorum, and its larval parasitoid Mesopolobus incultus. The laboratory bioassays revealed that both the herbivorous weevil and its larval parasitoid can locate their host plant and host via olfactory cues even in the presence of non-host odour. In a newly established two-circle olfactometer, the weeviĺs capability to detect host plant odour was not affected by odours from non-host plants. However, addition of non-host plant odours to host plant odour enhanced the weeviĺs foraging activity. The parasitoid was attracted by a combination of host plant and host volatiles in both the absence and presence of non-host plant volatiles in a Y-tube olfactometer. In dual choice tests the parasitoid preferred the blend of host plant and host volatiles over its combination with non-host plant volatiles. In the field, no indication was found that high plant diversity disturbs host (plant) location by the weevil and its parasitoid. In contrast, plant diversity was positively correlated with weevil abundance, whereas parasitoid abundance was independent of plant diversity. Therefore, we conclude that weevils and parasitoids showed the sensory capacity to successfully cope with complex vegetation odours when searching for hosts.

[Total hip arthroplasty by neuromuscular impairment: functional outcome]

INTRODUCTION

Studies which deal with the problems of total hip arthoplasty (THA) in patients with neuromuscular impairments are rare. The aim of this study was to examine whether THA for painful coxarthrosis in such patients relieved pain and improved functional outcome and how high the complication rate was.

MATERIAL AND METHODS

For this study 10 patients (13 hips) with neuromuscular impairment who had received a total hip arthroplasty for painful coxarthrosis were retrospectively identified. A chart review determined the preoperative functional level. For postoperative evaluation all patients completed a questionnaire, including a self-created modified hip score.

RESULTS

The average age of the patients at the time of follow-up was 42.1 years (range 26.5-62.2 years, standard deviation SD 9.9 years) and the minimum follow-up was 24 months (average 80.3 months, range 24-143 months, SD 47 months). Pain relief was obtained for all patients but two patients had a postoperative dislocation and four patients had a major complication (infection) requiring removal of the implant. Therefore, the follow-up rate at the final examination with completed questionnaires was 69% (9 out of 13 excluding patients with removal of THA). These patients showed an improved function from 42.2-83.66 points in the hip score (p=0.0006) and there was general satisfaction with the procedure.

DISCUSSION

Total hip arthroplasty can provide improved function in patients with neuromuscular impairment and severe coxarthrosis. The rate of complications was moderate in this series; however, the high infection rate in these patients should be kept in mind.

An elm EST database for identifying leaf beetle egg-induced defense genes

Background

Plants can defend themselves against herbivorous insects prior to the onset of larval feeding by responding to the eggs laid on their leaves. In the European field elm (Ulmus minor), egg laying by the elm leaf beetle ( Xanthogaleruca luteola) activates the emission of volatiles that attract specialised egg parasitoids, which in turn kill the eggs. Little is known about the transcriptional changes that insect eggs trigger in plants and how such indirect defense mechanisms are orchestrated in the context of other biological processes.

Results

Here we present the first large scale study of egg-induced changes in the transcriptional profile of a tree. Five cDNA libraries were generated from leaves of (i) untreated control elms, and elms treated with (ii) egg laying and feeding by elm leaf beetles, (iii) feeding, (iv) artificial transfer of egg clutches, and (v) methyl jasmonate. A total of 361,196 ESTs expressed sequence tags (ESTs) were identified which clustered into 52,823 unique transcripts (Unitrans) and were stored in a database with a public web interface. Among the analyzed Unitrans, 73% could be annotated by homology to known genes in the UniProt (Plant) database, particularly to those from Vitis, Ricinus, Populus and Arabidopsis. Comparative in silico analysis among the different treatments revealed differences in Gene Ontology term abundances. Defense- and stress-related gene transcripts were present in high abundance in leaves after herbivore egg laying, but transcripts involved in photosynthesis showed decreased abundance. Many pathogen-related genes and genes involved in phytohormone signaling were expressed, indicative of jasmonic acid biosynthesis and activation of jasmonic acid responsive genes. Cross-comparisons between different libraries based on expression profiles allowed the identification of genes with a potential relevance in egg-induced defenses, as well as other biological processes, including signal transduction, transport and primary metabolism.

Conclusion

Here we present a dataset for a large-scale study of the mechanisms of plant defense against insect eggs in a co-evolved, natural ecological plant–insect system. The EST database analysis provided here is a first step in elucidating the transcriptional responses of elm to elm leaf beetle infestation, and adds further to our knowledge on insect egg-induced transcriptomic changes in plants. The sequences identified in our comparative analysis give many hints about novel defense mechanisms directed towards eggs.

Multisensory non-photoperiodic cue advances the onset of seasonal breeding in Island canaries (Serinus canaria)

In most temperate zone vertebrates, photoperiodic change plays the major role in the timing of seasonal breeding. However, direct environmental stimuli such as temperature, rainfall, or availability of food are thought to be important for fine-tuning breeding activities. Building on evidence from wild Island canaries (Serinus canaria), the authors had shown advancing effects of green vegetation on breeding under captive, short-day conditions. So far, the precise, sensory modalities of this stimulatory cue are unknown. Here the authors present new data that confirm advanced breeding activities in the presence of green vegetation and narrow its stimulatory components. They found that direct exposure of the birds to fresh green vegetation represented the strongest stimulus and advanced breeding by up to 2 months compared to controls. In contrast, access to artificial green vegetation, extracts from green vegetation, or olfactory components alone had no such effects. This is, to the best of the authors' knowledge, the first experiment that examines sensory components of an effective, supplementary, non-photoperiodic cue in a temperate zone species. The data suggest that in order to use non-photoperiodic information to time breeding, birds must be able to integrate and process multisensory stimuli. Single non-photoperiodic sensory cues are insufficient to affect the timing of seasonal breeding.

Plants and insect eggs: how do they affect each other?

Plant-insect interactions are not just influenced by interactions between plants and the actively feeding stages, but also by the close relationships between plants and insect eggs. Here, we review both effects of plants on insect eggs and, vice versa, effects of eggs on plants. We consider the influence of plants on the production of insect eggs and address the role of phytochemicals for the biosynthesis and release of insect sex pheromones, as well as for insect fecundity. Effects of plants on insect oviposition by contact and olfactory plant cues are summarised. In addition, we consider how the leaf boundary layer influences both insect egg deposition behaviour and development of the embryo inside the egg. The effects of eggs on plants involve egg-induced changes of photosynthetic activity and of the plant's secondary metabolism. Except for gall-inducing insects, egg-induced changes of phytochemistry were so far found to be detrimental to the eggs. Egg deposition can induce hypersensitive-like plant response, formation of neoplasms or production of ovicidal plant substances; these plant responses directly harm the eggs. In addition, egg deposition can induce a change of the plant's odour and leaf surface chemistry which serve indirect plant defence with the help of antagonists of the insect eggs. These egg-induced changes lead to attraction of egg parasitoids and their arrestance on a leaf, respectively. Finally, we summarise knowledge of the elicitors of egg-induced plant changes and address egg-induced effects on the plant's transcriptional pattern.

Enemies in low places - insects avoid winter mortality and egg parasitism by modulating oviposition height

Oviposition site selection in insects is essential in terms of low egg mortality, high offspring survival and therefore a high reproductive output. Although oviposition height could be a crucial factor for the fitness of overwintering eggs, it has rarely been investigated. In this study the oviposition height of a polyphagous leaf beetle, Galeruca tanaceti Linnaeus in different habitats and at different times of the season was examined and its effect on egg clutch mortality was recorded. The leaf beetle occurs as an occasional pest on several agricultural plants. It deposits its eggs within herbaceous vegetation in autumn. Eggs are exposed to numerous biotic and abiotic mortality factors summarized as egg parasitism and winter mortality. Oviposition height of the leaf beetle was not uniform, but changed significantly with the structure of the habitat and during the season. Mean oviposition height per site (70.2+/-4.9 cm) was significantly higher than mean vegetation height (28.4+/-2.4 cm). Height of plants with egg clutches attached and oviposition height were significantly positively correlated. The results suggest that females try to oviposit as high as possible in the vegetation and on the plants selected. In accordance with this, the probability of egg parasitism and of winter egg clutch mortality significantly declined with increasing oviposition height. A preference of G. tanaceti for oviposition sites high up in the vegetation might therefore have evolved due to selection pressures by parasitoids and winter mortality.

Early Herbivore Alert: Insect Eggs Induce Plant Defense

Plants are able to "notice" insect egg deposition and to respond by activating direct and indirect defenses. An overview of these defenses and the underlying mechanisms is given from a tritrophic perspective. First, the interface between plant and eggs is addressed with respect to the mode of attachment of eggs on the plant surface. It is elucidated which plant cells might respond to components from insect eggs or the egg deposition. The scarce knowledge on the elicitors associated with the eggs or the egg-laying female is outlined. Since endosymbiotic microorganisms are often present on the eggs, and microorganisms are also abundant on the leaf surface, the role of these hidden players for eliciting oviposition-induced plant responses is considered. Furthermore, the question of which physiological and molecular processes are induced within the plant in response to egg deposition is addressed. Second, studies on the response of the herbivorous insect to oviposition-induced plant defenses are outlined. Third, the importance of oviposition-induced plant volatiles and contact cues for host and prey location of parasitoids and predators is discussed in the context of other informative chemicals used by carnivores when searching for food. Finally, physiological and ecological costs of oviposition-induced plant responses are addressed.

Determining the tick scutal index allows assessment of tick feeding duration and estimation of infection risk with Borrelia burgdorferi sensu lato in a person bitten by an Ixodes ricinus nymph

The risk of Borrelia burgdorferi sensu lato transmission from an infected vector tick to a host increases with increasing duration of tick feeding. In Ixodes ricinus nymphs, the main vector of B. burgdorferi s.l. in most parts of Europe, the transmission risk appears low to moderate within the first 24h of feeding but increases to >70% after only 36 h. In this study, the so-called scutal index, the ratio between tick abdominal length and scutum width, a very good measure of the level of tick engorgement, was investigated for its potential to assess the feeding duration of detached I. ricinus nymphs, thereby indicating the level of human infection risk with B. burgdorferi s.l. I. ricinus nymphs were allowed to feed in capsules on tick-naive Mongolian gerbils for 0, 12, 24, 36 h, or to repletion, in groups of up to 9 individuals. After tick removal, the scutal index of each tick (n=516) was determined using a stereomicroscope with an ocular micrometer. This was also possible, if the tick mouthparts were damaged. Although the scutal indices determined at 24 h versus 36 h post-attachment (a critical interval for B. burgdorferi transmission) differ significantly, there was some overlap between the two groups. However, by choosing a scutal index of 1.1 as a cut-off, it was possible to assign 93.2% of the ticks attached for 24h (n=310) to one group (low-risk group ticks) and 85.6% of those attached for 36 h (n=97) to the other (high-risk group ticks). This means that those people from whom I. ricinus nymphs with a scutal index >1.1 detached have a distinctly elevated risk of Borrelia infection and therefore more likely require medical attention.

[Surgery for fractures of the lower extremities in cases of chronic spinal cord injury]

According to the literature, the need for surgical treatment of fractures of the lower extremity in patients with chronic spinal cord injury (SCI) is very limited. Conservative management is usually presented as the treatment of choice. We present the results of a retrospective review of 55 fractures in 44 patients from 1996 to 2000 which were managed surgically. Rating of the outcome was based on basic clinical and radiological criteria. The results of the radiological investigation on bone remodeling and bone positioning after healing were rated as good or excellent in 43 and fair in five limbs. In five cases, the treatment failed. For 53 of the 55 fractures, the patients regained their normal level of independence. Comparing our results to those presented in the literature, we clearly had fewer complications as well as better clinical and radiological results. We therefore advocate surgical treatment as an appropriate choice of treatment for lower extremity fractures of patients with chronic SCI.

[Analysis of FIM-values during the hospital treatment of patients with acute spinal cord injury]

The cost pressures in the German health care system continue to rise. In the context of the introduction of the DRG system, adequate treatment of paraplegic and tetraplegic patients within the financial limits will become even more difficult. In dispute with health care insurance companies, scientifically sound studies have been lacking to justify a treatment lasting up to six months as an in-patient of individuals with acute spinal cord injury or disease. The FIM (Functional Independence Measurement), established as a reliable tool in the evaluation of the functional development of patients presenting with acute spinal cord lesions, has been used as the basic tool in our study. Under the conditions of a specialized spinal cord injury centre the FIM showed a statistically highly significant increase of functional independence during the entire course of treatment. No therapeutic standstill could be detected in order to determine a point of discharge. Even in the last six weeks of treatment significant progress in functional independence can be observed.

LC-MS determination of Taxus alkaloids in biological specimens

A semi-quantitative LC-MS method was developed for the detection of the pseudo alkaloids of Taxus baccata (yew) from human body fluids and tissue samples. This method was used to examine the cause of death of a 43-year-old man who died several hours after he drank a decoction of taxus leaves. Autopsy and histology demonstrated early signs of myocardial hypoxia. Since investigation of the stomach content did not yield evidence of taxus ingestion, the taxus alkaloids were determined in blood, stomach content and tissue samples of the deceased by LC-MS. The samples were prepared by solid phase extraction on RP-18 columns. Chromatographic separation was achieved by HPLC on a RP-8 column, coupled to an ion trap mass spectrometer (Finnigan LCQ). An atmospheric pressure electrospray ionisation was performed. Spectra of the alkaloids were recorded in the single MS mode and in the MS-MS mode and compared with reference spectra obtained from an extract of yew leaves. In the stomach content, the kidneys, the liver and a heart blood sample of the deceased, alkaloids of Taxus baccata, predominantly taxine B and iso-taxine B, were identified. The semi-quantitative evaluation of the heart blood revealed a taxine concentration of 11 micro g taxine/g. As far as we know this is the first case in which a semi-quantitative analysis of taxine alkaloids has been performed.

Use of a latissimus dorsi flap for treatment of infection in a neuropathic shoulder joint

STUDY DESIGN

Case report.

OBJECTIVES

To demonstrate the difficulties that can be encountered in diagnosis and treatment of an infected neuropathic shoulder in a paraplegic man.

SETTING

Spinal cord injury center in Germany.

METHOD

Ultimately, radical debridement and transplantation of a latissimus dorsi muscle flap.

RESULTS

Successful treatment of the infection, partial weight bearing, and limited restriction of range of motion in the affected shoulder.

CONCLUSION

The latissimus dorsi muscle flap can resolve the infection of a neuropathic shoulder.

[Suggestions for implementation of DRG in the fields of Orthopaedics and Trauma Surgery for 2004]

OBJECTIVE

The Implementation of a DRG-Variant in Germany - voluntarily since January 1 st, 2003 and obligatory from January 1 st, 2004 - has been leading to uncertainty, particularly in the hospitals, due to fears that currently practised German diagnostic and therapeutic measures will not be financed properly by a DRG-Variant. The G-DRG-Version 1.0 that was drawn up in connection with an executive order law is to a large degree identical to the Australian AR-DRG-Version 4.1. Adjustments to German requirements were made only marginally. Therefore it is necessary for every medical field to investigate by stock-taking to what extent currently practised German diagnostic and therapeutic measures are considered in the G-DRG-Version 1.0 and whether and where modifications and adaptations need to be made. In order to make qualified statements scientific evaluations of possible problems have to be made based German data. Therefore an evaluation was made of the mapping of the medical fields of orthopaedics and trauma surgery. The German Society of Trauma Surgery (DGU), the German Society of Orthopaedy and Orthopaedic Surgery (DGOOC) in cooperation with the DRG-Research-Group of the University Hospital Muenster, the German Hospital Federation (DKG) and the German Medical Association carried out a DRG evaluation project in order to investigate the medical and economical homogeneity of the case groups.

METHOD

12,645 orthopaedic and trauma surgery cases from 23 hospitals - 11 university hospitals and 12 non-university hospitals - were collected within an period of three months and were scientifically evaluated with regard to their performance homogeneity and length of stay homogeneity.

RESULTS

The data formed the basis for the proof of suspected deficiencies of mapping of orthopaedic and trauma surgery cases within the G-DRG-Variant. Based on the data and additionally on conclusions of medical experts when the number of cases were small, 14 suggestions for adaptation were proposed and submitted by the deadline of March 31 st, 2003 to the InEK.

CONCLUSION

The results of the DRG-Evaluation Project demonstrate the problems of mapping the very heterogenous and complex medical performances of orthopaedy and trauma surgery to a flat rate financing system that is not adapted properly to German conditions. The G-DRG-Variant Version 1.0 does not offer the sufficient possibilities of differentiation that are needed to map the various orthopaedical and trauma surgical measures in Germany.

Parasitic wasps learn and report diverse chemicals with unique conditionable behaviors

Parasitoids exploit numerous chemical cues to locate hosts and food. Whether they detect and learn chemicals foreign to their natural history has not been explored. We show that the parasitoid Microplitis croceipes can associate, with food or hosts, widely different chemicals outside their natural foraging encounters. When learned chemicals are subsequently detected, this parasitoid manifests distinct behaviors characteristic with expectations of food or host, commensurate with prior training. This flexibility of parasitoids to rapidly link diverse chemicals to resource needs and subsequently report them with recognizable behaviors offers new insights into their foraging adaptability, and provides a model for further dissection of olfactory learning related processes.

Management of degenerative changes and stenosis of the lumbar spinal canal secondary to cervical spinal cord injury

We describe the case of a 47-year-old female who sustained a C5/6 fracture with C6 complete spinal cord injury 26 years ago. She presented with increased spasticity of the lower extremities, the abdominal wall and episodes of autonomic dysreflexia. Imaging of the spine revealed post-traumatic kyphosis at the level of the injury and degenerative changes of the lumbar spine with marked facet joint hypertrophy at the level of L4/5 causing severe spinal canal stenosis. Discussants of this case comment on the possible pathophysiological mechanisms causing autonomic dysreflexia, especially the development of degenerative changes, Charcot arthropathy and the role of tethering mechanisms. The diagnostic options and management approaches are also discussed.

Use of the ring fixator in the treatment of fractures of the lower extremity in long-term paraplegic and tetraplegic patients

STUDY DESIGN

Retrospective study.

OBJECTIVES

To examine the value of operative fracture stabilization by means of the ring fixator in fractures of the lower extremity in the presence of chronic paralysis caused by transverse lesions of the spinal cord.

SETTING

A specialist center for the treatment of spinal cord injuries in Germany.

METHODS

Clinical examination of the lower extremities with side-for-side comparison, radiological investigation of the fractures, patient survey.

PATIENTS

In 21 patients with chronic spinal cord lesions, 22 fractures of the lower extremities were treated with the ring fixator.

RESULTS

At follow-up a mean of 41.5 months after fracture healing it could be shown that movement in the knee and ankle joints on the same side as the fracture was not restricted by more than 10 degrees in any of our patients. No losses affecting activities of daily living were reported, and 19 of the 21 patients were satisfied with the result achieved with this technique. After four of the 22 operations there were complications. Malalignments were visible radiologically following five of the fractures.

CONCLUSIONS

In osteoporosis-induced fractures of the lower extremities in chronically paraplegic and tetraplegic patients, fracture stabilization with the ring fixator, with fewer complications and better results in terms of joint mobility, is superior to the conservative treatment so far given preference in the literature. It should be offered as an alternative to conservative treatment in the case of pathological fractures.

Associative learning of complex odours in parasitoid host location

In this paper we address the question how hymenopteran parasitoids deal with complex odour bouquets, using Microplitis croceipes (Cresson) (Hymenoptera: Braconidae) as a model. We examined the capacity of Microplitis croceipes to respond to individual compounds in flight chamber experiments after conditioning parasitoids with a mixture consisting of 2-octanone, methyl jasmonate and beta-caryophyllene. Parasitoids were given a choice between single compounds from the training mixture and beta-ocimene as an unrewarded alternative. When compared with control individuals lacking experience with the odour mixture, parasitoids trained to the odour blend showed an increased preference for 2-octanone and beta-caryophyllene, but not for methyl jasmonate. However, when trained with methyl jasmonate alone, parasitoids were able to respond to this compound. This demonstrates that parasitoids can learn to respond to individual compounds following experience with an odour mixture. However, for certain compounds of a mixture, learning can be blocked by other mixture components. Further experiments in which parasitoids were conditioned and challenged with two compound mixes confirmed that the olfactory background can affect recognition of individual compounds.

[Sequelae of diabetes mellitus in the vertebral column and spinal cord]

Diffuse idiopathic skeletal hyperostosis (DISH) is a chronic disease of the spine characterized by a significant association with metabolic alterations such as diabetes mellitus. Diabetes decreases the immunocompetence and increases the susceptibility to infections such as spondylitis, spondylodiscitis, and epidural abscess with spinal cord lesions in a high percentage of the cases. Microangiopathic changes of the intrinsic vasculature of the spinal cord are rare and mild. In a retrospective study of 784 acute spinal cord lesions, suspected diabetes could be found in only 13 patients. Neurophysiological and animal experiments as well as pathological studies have provided proof for the presence of diabetic myelopathy. Diabetic neuroarthropathy of the spine is rare, but important in the differential diagnosis of spinal disorders.

Improvements in activities of daily living following functional hand surgery for treatment of lesions to the cervical spinal cord: self-assessment by patients

STUDY DESIGN

Tetraplegic patients were tested for hand strength before and after hand surgery. They also answered questions about how they rated the results of surgery.

OBJECTIVES

Presentation of the efficacy of reconstruction of hand raising, lateral grip, and cylindrical grip in the tetraplegic hand.

SETTING

The study was conducted in the Werner Wicker Clinic, Bad Wildungen, Germany, from 1991 to 1998.

METHODS

The results of reconstruction surgery performed on 23 tetraplegic hands, as reflected in lifting the hand (n=3), lateral grip (n=21), and cylindrical grip (n=14), are presented. In a follow-up study in 22 patients, their management of activities of daily living 34.1 months (9-51 months) after the surgery is compared with the preoperative situation. Subjective satisfaction levels were elicited for each of the 22 patients by means of a questionnaire.

RESULTS

The gain in force corresponded to 893 g (150-1500 g) for cyclindrical grip and 488 g (100-1200 g) for lateral grip, while they were able to develop grade 4 force for lifting the hand. After the operation 28 aids/appliances that patients had formerly used regularly were no longer necessary. There were 75 separate activities listed in the questionnaire, and on average the 22 patients were able to perform 8.7 (0-20) more of these. Most patients (19) said they would advise others to have the operation and 18, that they would have the operation again. There were 12 complications in nine patients.

CONCLUSION

Reconstructive surgery on the hands of tetraplegic patients leads to gains in both cylindrical grip and lateral grip force and to increased manual dexterity. Patient satisfaction with the procedure is high.

The effect of molecular structure on olfactory discrimination by the parasitoid Microplitis croceipes

Flight chamber experiments were conducted to examine the capacity of the larval parasitoid Microplitis croceipes (Hymenoptera: Braconidae) to learn to distinguish between structurally related aliphatic alcohols differing in the carbon chain-length and the position of the functional group, and between an alcohol and the respective aldehyde. The parasitoid's ability to discriminate between the components depended on the chain-length of the alcohol to which they had been conditioned. Discrimination improved with increasing difference in carbon chain-length, e.g. the parasitoids made clear distinction between 1-hexanol and 1-octanol. Microplitis croceipes could also distinguish different isomers of six-carbon alcohols on the basis of the position of the alcoholic group as well as between 1-hexanol and 1-hexanal. The learning abilities of M. croceipes correspond to the specificity of antennal odour receptors towards aliphatic alcohols and aldehydes in previous electrophysiological studies of M. croceipes and other insects. Differences in perception or processing of single compounds might reflect differences of their ecological relevance.

Pressure distribution measurements in wheelchair use

There is a growing number of mobility-impaired and wheelchair-dependent patients caused by diseases and injuries of the central nervous system. The risk is high for pressure sores to develop due to disturbances of the motor, sensory, and autonomic nervous system. Numerous seating systems for prophylaxis and treatment of decubitus ulcer are available. To identify risk parameters, the literature on animal experiments regarding pressure ulcers was reviewed. A study on the reproducibility of the analysis method with capacitive sensors tested in ten paraplegics with 470 measurements is presented. It shows the reliability of the procedure.

[Amputation of the lower extremity in paraplegic patients. Etiology, sequelae and patient management]

Up to now, there are not many reports about indications and guidelines for prosthetic fitting in amputated paraplegics and tetraplegics. In a review of 35 spinal cord patients with 42 amputations of the lower extremity, data on the neurological level, cause of injury, level of amputation, long-term complications, prosthetic fitting, and usage of the prostheses in daily life are presented. Everyday usage of the prostheses is reported for 15 patients.

Analysis of volatiles induced by oviposition of elm leaf beetle Xanthogaleruca luteola on Ulmus minor

Egg deposition of the elm leaf beetle Xanthogaleruca luteola causes the emission of volatiles from its food plant, Ulmus minor. These volatiles are exploited by the egg parasitoid, Oomyzus gallerucae, to locate its host. In contrast to other tritrophic systems, the release of volatiles is not induced by feeding but by egg deposition. Previous investigations showed that the release is systemic and can be triggered by jasmonic acid. Comparison of headspace analysis revealed similarities in the blend of volatiles emitted following egg deposition and feeding. The mixture consists of more than 40 compounds; most of the substances are terpenoids. Leaves next to those carrying eggs emit fewer compounds. When treated with jasmonic acid, leaves emit a blend that consists almost exclusively of terpenoids. Dichloromethane extracts of leaves treated with jasmonic acid were also investigated. After separation of extracts of jasmonate induced elm leaves on silica, we obtained a fraction of terpenoid hydrocarbons that was attractive to the parasitoids. This indicates that jasmonic acid stimulates the production of terpenoid hydrocarbons that convey information of egg deposition to the parasitoid.

Electromyogram-controlled functional electrical stimulation for treatment of the paralyzed upper extremity

Spinal cord lesions at level C5 to C6 lead to loss of hand functions and lesions at C4 to additional deficits of arm functionality. The presented dual channel surface stimulator with dual channel electromyogram (EMG) measurement was developed to investigate control strategies for an EMG-controlled implantable stimulation system and serves in addition as a therapy device for patients with partial innervation but weak muscle force. Four different control strategies for stimulation amplitude are available. The amplitude can be preset manually or can follow the preprocessed EMG signals proportionally. The shoulder control program allows proportional control of both stimulation channels with one EMG channel while the second EMG channel serves as the channel selector. Finally, a special feedback training program triggers a stimulation burst when EMG activity is detected. During a 2 year patient study, 18 patients from 2 hospitals and 1 rehabilitation center performed the feedback training. Almost all patients obtained an improvement of functionality. Apart from muscle strengthening, the feedback effect led to an improvement of proprioception and supported relearning of motions. For the documentation of the training status, functional muscle test (British Medical Research Council) and measurements of power, angle, torque, muscle fatigue, and EMG were performed. Obviously, EMG triggered stimulation provides several advantages compared to conventional passive electrical stimulation.

Residual deformity of the spinal canal in patients with traumatic paraplegia and secondary changes of the spinal cord

INTRODUCTION

The effect of spinal deformity with posttraumatic kyphosis and stenosis of the spinal canal in producing secondary changes of the spinal cord has been discussed for quite some time. Since the advent of magnetic resonance imaging (MRI), 20-40% of patients with posttraumatic paraplegia are found to develop hydromyelia. PURPOSE OF OUR STUDY: To evaluate the influence of residual spinal deformity, defined by the extent of the posttraumatic kyphosis and stenosis, in the development of posttraumatic hydromyelia.

MATERIAL AND METHODS

Two hundred and seven cases of traumatic paraplegia with MRI follow-up were reviewed retrospectively. A minimum of 3 years duration between trauma and MRI study was required (mean 10.6 years [3.2-38.3]). For statistical analysis two groups of patients were formed: with hydromyelia and without hydromyelia. After healing of the fracture, the extent of the kyphosis and stenosis, as well as the characteristics of the paraplegia were noted.

RESULTS

We found that 53 patients had hydromyelia. A highly significant correlation was found for the extent of spinal stenosis and the amount of kyphosis. Cluster analysis indicated that patients with more than 15 degrees of posttraumatic kyphosis and more than 25% of stenosis were twice as likely to develop hydromyelia. The level of the lesion and the remaining neurological function was not proven to have any influence towards the development of hydromyelia.

CONCLUSIONS

These results support the idea that chronic mechanical stress to the spinal cord increases the risk for the development of hydromyelia. Surgical reconstruction should be considered for all patients to prevent secondary changes of the spinal cord.

Resection of heterotopic ossification of the hip in spinal cord injured patients

Twenty nine spinal cord injury patients were treated by resection of heterotopic ossification in 41 hips. The average follow-up period after surgery was 4.2 years. The mean time to surgery after injury was 82.1 months. The indications for surgery were seating problems, loss of function, pressure sores and pain. The average preoperative motion in flexion and extension was 21.95 degrees, the average intraoperative motion was 94.51 degrees. The average motion at follow-up evaluation was 82.68 degrees. Clinical relevant recurrence occurred in three patients. Complications excluding recurrence occurred in 10 hips, including deep and superficial wound infections, fracture, aneurysm and pressure ulcer. The operation was followed by a specific regime of physiotherapy and radiation therapy.