Neutrophil extracellular traps kill bacteria

Neutrophils engulf and kill bacteria when their antimicrobial granules fuse with the phagosome. Here, we describe that, upon activation, neutrophils release granule proteins and chromatin that together form extracellular fibers that bind Gram-positive and -negative bacteria. These neutrophil extracellular traps (NETs) degrade virulence factors and kill bacteria. NETs are abundant in vivo in experimental dysentery and spontaneous human appendicitis, two examples of acute inflammation. NETs appear to be a form of innate response that binds microorganisms, prevents them from spreading, and ensures a high local concentration of antimicrobial agents to degrade virulence factors and kill bacteria.     

Intraoperative use of ultrasonography during continuous dorsal laminectomy in two dogs with caudal cervical vertebral instability and malformation ("Wobbler syndrome")

OBJECTIVE: To describe an intraoperative ultrasound imaging technique during dorsal laminectomy in 2 dogs with caudal cervical vertebral instability and malformation (CCVIM, "Wobbler syndrome"). STUDY DESIGN: Clinical case report. SAMPLE POPULATION: Two dogs with CCVIM. RESULTS: On neurologic examination there was tetraparesis with upper motor neuron signs in the thoracic limbs and lower motor neuron signs in the pelvic limbs in dog 1, and hyperreflexia of the rear limbs, normoreflexia of the right front limb, and hyporeflexia of the left front limb of dog 2. Both dogs had signs of marked cervical pain and radiographic signs of cervical spinal cord compression. Intraoperative ultrasonography of the spinal cord revealed protruding intervertebral disc at C5-6 (dog 1) and C6-7 (dog 2), and the parallel borders of the spinal cord and central canal after decompression. Continuous dorsal laminectomy (CDL) resulted in improvement over 16 months (dog 1) and 20 months (dog 2). CONCLUSIONS: Intraoperative ultrasonographic imaging of the cervical spinal cord after CDL was helpful in determining adequate decompression (postlaminectomy) of the spinal cord in relation to the ventral and lateral compressive component(s) and to image the protruding intervertebral disc. CLINICAL RELEVANCE: Intraoperative ultrasonography can be used to provide valuable information on the spinal cord and surrounding soft tissues for the neurosurgeon.     

Black locust (<Emphasis Type="Italic">Robinia pseudoacacia</Emphasis> L.) as a multi-purpose tree species in Hungary and Romania: a review

Black locust (Robinia pseudoacacia L.) was the first North-American tree species imported to Europe at the beginning of the seventeenth century. It is commonly planted worldwide because of its adaptability to environmental stresses, its valuable wood, easy propagation, frequent and abundant seed production, excellent coppicing, high seedling survival, and relatively high wood yield. In Europe, Romania and Hungary have the most highly-developed black locust growing techniques and experiences. As a result of increasing interest in black locust in many countries, this review aims to provide a comprehensive overview of state-of-the-art site requirements, propagation, improvement and management (including growth and yield as well as use in energy plantations).     

Effect of growing medium water content on the biological control of root pathogens in a closed soilless system

Summary

The water content of the growing medium and its interaction with a biocontrol agent was studied in a closed soilless culture system in order to identify factors that could increase the efficiency and decrease the variability of biocontrol agents. Pumice was chosen as the growing medium because of its high water-holding capacity and in view of the high water content required for the growth of the root pathogen. The commercial biocontrol agent Binab T (active strains Trichoderma polysporum and T. harzianum) was evaluated at 50% and 70% water content. Studies were carried out in a controlled environment, in a climate chamber, using tomato as the model plant and Pythium ultimum as the model pathogen. Pathogen levels were affected by the water content of the medium and the biocontrol treatment, while the amount of biocontrol agent was not affected by the water content of the growing medium. The Trichoderma strains in Binab T were able to reduce the amount of pathogen and the incidence of disease at both water contents tested. The biocontrol activity of Binab T against P. ultimum, as indicated by the level of glucanase production, was affected by variations in the water content of the growing medium. The pathogen, the biocontrol agent, and the water content of the growing medium, all had an impact on the microbial communities resident in the system.     

What is the SMARTest way to breed plants and increase agrobiodiversity?

The evaluation and use of the vast diversity contained in plant genetic resources (PGR) is a main challenge for today’s plant breeding. The use of molecular markers has hugely increased the knowledge about genetic diversity and great hopes are raised about the potential of marker assisted selection [MAS; sometimes also termed SMART breeding (Selection with Markers and Advanced Reproductive Technologies)] to help increasing the use of PGR and maintaining crop genetic diversity. Another approach growing attention has been paid to over the past two decades and which also aims to increase variation in crops is evolutionary and participatory breeding (EPB). In this paper we discuss both the potential of marker-assisted breeding strategies and the potential of EPB breeding to contribute to the maintenance, increase and development of agrobiodiversity. The potentials of molecular markers in the evaluation and use of PGR and their documented contribution to agrobiodiversity are reviewed and results from guided interviews with scientists and breeders are given. Despite tremendous research efforts involving molecular markers, it is still difficult to obtain a clear picture how molecular markers contribute to the use of PGR in plant breeding. Minor and major crops do not benefit to the same degree from recent developments in marker technology. It therefore depends at least in part on economic considerations whether SMART breeding or EPB strategies or both are implemented in the breeding process of a crop. A general decision in favor or against MAS or EPB when breeding for diversity would not yield optimum results.     

Concentrations of Some Metabolites Produced by Fungi of the Genus Fusarium and Selected Elements in Spring Spelt Grain

The aim of this study was to determine the content of selected elements and metabolites produced by fungi of the genus Fusarium in spelt (Triticum spelta L.) grain and husks and common wheat (T. aestivum L.) grain. Concentrations of trichothecenes, a volatile metabolite trichodiene (TRICH), as well as ergosterol (ERG) and adenosine 5′‐triphosphate (ATP) (a total microbial biomass indicator), were assessed. Toxin concentrations in spelt grain and husks harvested in 2003 and 2004 were comparable. Average deoxynivalenol concentrations reached 450 and 523 μg/kg in grain and 2,162 and 855 μg/kg in husks, respectively. Spelt grain, in comparison with common wheat grain, contained significantly higher concentrations of P, S, Mg, Zn, and Cu and a lower concentration of Al, whereas the concentrations of Ca, Fe, and Pb were significantly higher in the husks than in the grain of this cereal. A comparison of concentrations of Fusarium spp. metabolites in the grain of spelt and common wheat showed that the total concentration of mycotoxins and TRICH was slightly lower in T. spelta, whereas common wheat grain contained lower concentrations of ERG and ATP. The obtained results indicate that spelt husks contain considerable concentrations of trichothecenes.     

Maximum likelihood inference for seed and pollen dispersal distributions

Seed and pollen dispersal are both important factors in the demography and population genetic structure of plant populations. How does one model and infer dispersal patterns? One approach is to map the locations of individuals in a population and use genetic information to suggest which parents generated which offspring. This article develops models and a maximum likelihood inference framework for data of this type. The procedure will be illustrated on data from a population of Chamaelirium luteum, an herbacious plant of the forest floor. This article shows how the proposed method avoids some of the problems found in the original analysis of these data. The approach also allows us to uncover some additional patterns in the data: differencesin the seed dispersal distributions between years.     

Chemical and microbial properties in a greenhouse loamy soil after steam disinfestation alone or combined with CaO addition

Steam disinfestation represents an increasingly attractive strategy to control soil-borne pathogens and weeds both in greenhouses and field crops. Beyond pest control, steam injection has the potential to alter soil nutrient dynamics and composition of bacterial communities. This study investigated the impact of a soil-steaming method (the Bioflash™ system) on main chemical (total organic C, TOC; total N, TN; cation exchange capacity, CEC; exchangeable Na, K, Mg and Ca; KCl-extractable ammonium and nitrate, DTPA-exchangeable Mn) and microbial (microbial biomass C, MBC; genetic structure of bacterial communities) properties in a greenhouse loamy soil. Treatments were carried out by using a self-propelled soil-steaming machine operating at two steaming modes (deep or shallow) in combination or not with addition of an exothermically reacting compound (CaO at a 1000 kg ha⁻¹ rate). Soils from a five-treatment (NS, non-steamed soil, DS, deep steam injection; DS + E, deep steam injection plus CaO; SS, shallow steam injection; SS + E, shallow steam injection plus CaO) plot block were sampled before steaming and after 8, 19, 54 and 91 days. Compositional shifts in the structure of soil bacterial communities were monitored by denaturing gradient gel electrophoresis (DGGE) fingerprinting of soil-extracted 16S rRNA gene fragments, using primers specific for Bacteria and Actinobacteria. Maximum soil temperature reached 70 °C (DS) and 82 °C (DS + E) in the 10-20 cm layer; and 50 °C (SS) and 53 °C (SS + E) in the 0-10 cm layer. TOC, TN, CEC, exchangeable Na, Mg and Ca were not statistically affected by soil steaming, CaO addition, depth of injection or their interactions. Conversely, SS promoted a large release of exchangeable K, notwithstanding CaO addition. Steam disinfestation significantly stimulated ammonium release, which further increased in CaO-treated steamed soils. Generally ammonium and nitrate pools varied oppositely, being the latter markedly reduced at the end of the observation period. Available Mn was significantly increased by soil steaming, but it was depressed when steaming was combined with CaO addition. Soil steaming markedly reduced the MBC, especially in DS-treated and SS-treated plots. The genetic structure of soil bacterial and actinobacterial communities was largely unresponsive to the steaming treatments. Even though the Bioflash™ system did not cause bacterial eradication or compositional shifts in bacterial community structure, soil steaming stimulated an increased release of soluble nutrients (K⁺, Mn²⁺, NH₄⁺-N). Over a longer perspective, excessive soil resources exploitation and potential risks of Mn toxicity should be cautiously considered especially in repeatedly (and eventually acid) steamed soils.     

Various Circumstances Regarding Initial Allergen Exposure and Their Influence on Development of Insect Bite Hypersensitivity in Horses

Insect bite hypersensitivity (IBH), an allergic reaction to the saliva of Culicoides, occurs in all horse breeds and is a severe problem. In this study, we aimed at exploring whether exterior conditions, such as duration of allergenic exposure during the first summer and age of the horses at the time of import, influence the development of IBH. Additionally, data were analyzed regarding the period IBH started after birth and after import. Datasets for 582 horses were collected. The horses were locally born Icelandic horses and horses of other breeds with IBH, as well as imported Icelandic horses, both affected and nonaffected. For locally born horses, time of birth and duration of allergen exposure during the first summer had no influence on the prevalence of IBH. The disease started mostly in their third year of life. The majority of the imported horses affected caught IBH during their first year in Central Europe. Older imported horses seemed to develop IBH quicker than younger animals. Animals imported in their first winter are exposed to the allergen when they are at least 7 months old. They experienced approximately the same low risk of developing IBH as locally bred horses. The risk of IBH increased with the horses’ age at import. From our data, we conclude that the period to develop successful immune tolerance goes beyond the perinatal phase and is longer than formerly supposed.