Studies of endovascular treatment for acute ischemic stroke have identified general anesthesia as a predictor for poor outcome in comparison with local anesthesia/sedation. This retrospective study ...attempts to identify modifiable factors associated with poor outcome, while adjusting for baseline stroke severity, in patients receiving general anesthesia.
We reviewed charts of 129 patients treated between January 2003 and September 2009. The primary outcome was the modified Rankin Score of 0-2 for 3 months poststroke. Predictors of neurologic outcome included baseline National Institutes of Health Stroke Scale score, blood glucose concentration, and age. Additional risk factors evaluated were prolonged stroke onset-treatment interval and systolic blood pressure less than 140 mmHg. Choice of local anesthesia or general anesthesia was recorded.
The study group was 96 out of 129 patients for whom modified Rankin Scale scores were available; 48 patients received general anesthesia and 48 local anesthesia. The proportion of patients with "good" outcomes were 15% and 60% in the general anesthesia group and local anesthesia group, respectively (P < 0.001). Lowest systolic blood pressure and general anesthesia were correlated (r = -0.7, P < 0.001). Independent predictors for good neurologic outcome were local anesthesia, systolic blood pressure greater than 140 mmHg, and low baseline stroke scores.
Adjusted for stroke severity, patients who received general anesthesia for treatment are less likely to have a good outcome than those managed with local anesthesia. This may be due to preintervention risk not included in the stroke severity measures. Hypotension, more frequent in the general anesthesia patients, may also contribute.
In this study, molecular (ribosomal sequence data), morphological and cross-hybridization properties were used to identify a new Steinernema sp. from Florida, USA. Molecular and morphological data ...provided evidence for placing the novel species into Clade V, or the 'glaseri-group' of Steinernema spp. Within this clade, analysis of sequence data of the rDNA genes, 28S and internal transcribed spacer (ITS), depicted the novel species as a distinctive entity and closely related to S. glaseri and S. cubanum. Additionally, cross-hybridization assays showed that the new species is unable to interbreed with either of the latter two species, reinforcing its uniqueness from a biological species concept standpoint. Key morphological diagnostic characters for S. khuongi n. sp. include the mean morphometric features of the third-stage infective juveniles: total body length (average: 1066 μm), tail length (average: 65 μm), location of the excretory pore (average: 80.5 μm) and the values of c (average: 16.4), D% (average: 60.5), E% (average: 126) and H% (average: 46.6). Additionally, males can be differentiated from S. glaseri and S. cubanum by the values of several ratios: D% (average: 68), E% (average: 323) and SW% (average: 120). The natural distribution of this species in Florida encompasses both natural areas and citrus groves, primarily in shallow groundwater ecoregions designated as 'flatwoods'. The morphological, molecular, phylogenetic and ecological data associated with this nematode support its identity as a new species in the S. glaseri-group.
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► Coarse sand in planting holes increased nematode parasitism of root weevils. ► Coarse sand increased species diversity of entomopathogenic nematodes. ► Trees grew larger, survived ...better and produced more fruit in coarse sand.
In Florida, a root weevil pest of citrus, Diaprepes abbreviatus, is more damaging and attains higher population density in some orchards on fine textured, poorly drained “flatwoods” soils than in those on the deep, coarse sandy soils of the central ridge. Previous research revealed that sentinel weevil larvae were killed by indigenous entomopathogenic nematodes (EPNs) at significantly higher rates in an orchard on the central ridge, compared to one in the flatwoods. We hypothesized that filling tree planting holes in a flatwoods orchard with sandy soil from the central ridge would provide a more suitable habitat for EPNs, thereby reducing weevil numbers and root herbivory. Fifty trees were planted in oversized planting holes filled with coarse sand and 50 trees were planted in native soil in a split plot design where whole plots were species of introduced EPNs and split plots were soil type. Each of Steinernema diaprepesi, Steinernema riobrave, Heterorhabditis indica, Heterorhabditis zealandica, or no EPNs were introduced into the rhizospheres in 10 plots of each soil type. During four years, EPN numbers in soil samples and the relative abundance of seven species of nematophagous fungi associated with nematodes were measured three times using real-time PCR. The efficacy of EPNs against sentinel weevil larvae was also measured three times by burying caged weevils in situ. EPN species richness (P=0.001) and diversity (P=0.01) were always higher in sand than native soil. Soil type had no effect on numbers of EPNs in samples, but EPNs were detected more frequently (P=0.01) in plots of sandy soil than native soil in 2011. Two nematophagous fungi species, Paecilomyces lilacinus and Catenaria sp. were significantly more abundant in nematode samples from sandy soil on all three sampling dates. Efficacy of EPNs against weevil larvae was greater in sandy soil inoculated with S. diaprepesi (P=0.03) in June 2010 and in all treatments in sandy soil in May 2011 (P=0.03). Sixty-eight percent more adult weevils (P=0.01) were trapped emerging from native soil during two years than from sandy soil. By May 2011, the cumulative number of weevils emerging from each plot was inversely related (P=0.01) to the numbers of EPNs detected in plots and to EPN efficacy against sentinels. Three trees in sandy soil died as a result of root herbivory compared to 21 trees in native soil. Surviving trees in sandy soil had trunk diameters that were 60% larger (P=0.001) and produced 85% more fruit (P=0.001) than those in native soil. Although it is not possible to characterize all of the mechanisms by which the two soil treatments affected weevils and trees, substitution of sand for native soil was an effective means of conserving EPNs and shows promise as a cultural practice to manage D. abbreviatus in flatwoods citrus orchards with a history of weevil damage to trees.
Quantitative real-time PCR (qPCR) techniques are being increasingly used to provide accurate and reliable methods to identify and quantify cryptic organisms in soil ecology. Entomopathogenic nematode ...(EPN) diversity in Florida is known to be extensive and our phylogenetic studies of the D2D3 and ITS regions showed the occurrence of an additional species-complex in the Steinernema glaseri- group in widely separated locations of the peninsula. To address ecological studies, we developed and used qPCR assays to detect and quantify six species of EPN that are naturally distributed in Florida citrus orchards (Steinernema diaprepesi, Steinernema riobrave, Heterorhabditis indica, Heterorhabditis zealandica, Heterorhabditis floridensis and an undescribed species in the S. glaseri group) and an exotic species, S. glaseri. Species-specific primers and TaqMan® probes were designed from the ITS rDNA region. No nonspecific amplification was observed in conventional or qPCR when the primers and probes were tested using several populations of each of the Florida species and other exotic EPN species. Standard curves were established using DNA from pure cultures. We optimised a protocol for extracting nematodes and DNA from soil samples that can detect one EPN added to nematode communities recovered by conventional extraction protocols. A survey of an 8-ha orchard in April 2009 compared the EPN spatial patterns derived from qPCR to that obtained by baiting soil samples with Galleria mellonella larvae. The patterns were also compared to those derived from the same site in 2000-01 by repeatedly (12 sampling events) baiting soil in situ with caged larvae of the root weevil Diaprepes abbreviatus. The qPCR assay was more efficient than the Galleria baiting method for detecting the EPN species composition in population mixtures. Moreover, the spatial patterns of EPN in this orchard were remarkably stable over the course of nearly a decade. The pattern of H. zealandica detected at the site 8 years earlier was related to those derived by qPCR (P = 0.002) and from sample baiting (P = 0.02). The spatial pattern of H. indica derived from qPCR, but not that from sample baiting, was also related to the earlier pattern (P = 0.01). The qPCR assay developed here is a fast, affordable and accurate method to detect and quantify these EPN species in soil and offers great potential for studying the ecology of EPN.
Modern agricultural systems can benefit from the application of concepts and models from applied ecology. When understood, multitrophic interactions among plants, pests, diseases and their natural ...enemies can be exploited to increase crop production and reduce undesirable environmental impacts. Although the understanding of subterranean ecology is rudimentary compared to the perspective aboveground, technologies today vastly reduce traditional obstacles to studying cryptic communities. Here we emphasize advantages to integrating as much as possible the use of these methods in order to leverage the information gained from studying communities of soil organisms. PCR-based approaches to identify and quantify species (real time qPCR and next generation sequencing) greatly expand the ability to investigate food web interactions because there is less need for wide taxonomic expertise within research programs. Improved methods to capture and measure volatiles in the soil atmosphere in situ make it possible to detect and study chemical cues that are critical to communication across trophic levels. The application of SADIE to directly assess rather than infer spatial patterns in belowground agroecosystems has improved the ability to characterize relationships between organisms in space and time. We review selected methodology and use of these tools and describe some of the ways they were integrated to study soil food webs in Florida citrus orchards with the goal of developing new biocontrol approaches.
Quantitative real‐time PCR (qPCR) is a powerful tool to study species of cryptic organisms in complex food webs. This technique was recently developed to detect and quantify several species of ...entomopathogenic nematodes (EPNs), which are widely used for biological control of insects, and some natural enemies of EPNs such as nematophagous fungi and the phoretic bacteria Paenibacillus sp. and Paenibacillus nematophilus. A drawback to the use of primers and TaqMan probes designed for Paenibacillus sp. is that the qPCR also amplified Paenibacillus thiaminolyticus and Paenibacillus popilliae, two closely related species that are not phoretically associated with EPNs. Here, we report that the detection of Paenibacillus sp. DNA in nematode samples was two orders of magnitude greater (P < 0.001) when the bacterium was added to soil together with its EPN species‐specific host Steinernema diaprepesi than when it was added concomitantly with other EPNs or with species of bacterial‐feeding nematodes. Just 6% of samples detected trace amounts of P. thiaminolyticus and P. popilliae exposed to the same experimental conditions. Thus, although the molecular assay detects Paenibacillus spp. DNA in nonphoretic associations, the levels are essentially background compared to the detection of Paenibacillus sp. in association with its nematode host.
An ‘Advanced Production System’ (APS) dramatically changed soil properties such as pH (P<0.001; panel A) compared to properties in conventional citriculture (CC). Responses by soil organisms to these ...changes included higher infestation rates by the bacterium Paenibacillus sp. on the entomopathogenic nematode Steinernema diaprepesi (P=0.05; panel B), which may have contributed to reduced numbers of infective juveniles (IJs) of native nematodes in APS plots (P=0.01; panel C). Display omitted
•‘Advanced’ system (ACP) modifies soil properties and citrus trees mature earlier.•Native entomopathogenic nematode (EPN) numbers were reduced by ACP.•Higher Paenibacillus sp. infestation rate on S. diaprepesi in APS.•Nematophagous fungal responses to EPNs depended on EPN species.•APS has the potential to exacerbate herbivory by subterranean pests.
Since its first detection in 2005, the bacterial disease huanglongbing (HLB or citrus greening) has emerged as a critical threat to the citrus industry in Florida. An “Advanced Production System” (APS) could mitigate the impact of HLB by bringing citrus trees into production more quickly and economically than conventional citriculture methods. However, unlike conventional practices, APS fertigates plants daily, thereby changing the soil properties in ways that might impact soil biota. We tested the hypothesis that changes to soil properties caused by APS would affect the abundance of native entomopathogenic nematodes (EPNs) and/or the survival of augmented EPNs. The densities of organisms at different trophic levels were measured by real-time qPCR in three experiments conducted in an ongoing field experiment. Target organisms included 6 entompathogenic nematodes, 5 nematophagous fungi (NF) and a phoretic bacterium, Paenibacillus sp. Soil properties, free-living nematodes and citrus fibrous roots were also measured. Compared to soil under conventional citriculture (CC), APS increased soil pH and Mg content, while reducing the electrical conductivity, and content of K, Mn and Fe. The naturally occurring EPN Steinernema diaprepesi was 5times less abundant in APS plots where these nematodes were more heavily encumbered by the phoretic bacterium Paenibacillus sp., which limits the foraging success of EPNs. In general, when EPNs were augmented in either treatment, fewer Steinernema riobrave than Heterorhabditis indica were recovered and recovery of both species declined rapidly over time. As seen with native S. diaprepesi, fewer augmented S. riobrave were recovered from APS plots in two of the three experiments, whereas the management system did not affect the recovery of H. indica. More of some endoparasitic and trapping NF were recovered from soil augmented with S. riobrave than with H. indica. However, variation in the responses of NF to the management systems suggests that these NF species were not primarily responsible for the steinernematid responses to APS. Although APS has the potential to reduce EPN populations and exacerbate herbivory by subterranean pests such as the root weevil Diaprepes abbreviatus, additional study of the physical causes of this effect may reveal ways to avoid the problem.
Differently from previous studies that used Transcranial Doppler (TCD) and functional MRI (fMRI) for cerebral vasomotor reactivity (CVR) assessment in patients with carotid stenosis (CS), we assessed ...CVR using an identical stimulus, the Breath-Holding Test (BHT). We included 15 patients with CS and 7 age-matched controls to verify whether fMRI responded differently to BHT between groups and to calculate the agreement rate between tests. For TCD, impaired CVR was defined when the mean percentage increase on middle cerebral artery velocities was ≤31% on 3 consecutive 30-s apnea intercalated by 4-min normal breathing intervals. For fMRI, the percent variation on blood oxygen level-dependent (BOLD) signal intensity in the lentiform nucleus (LN) ipsilateral to the CS (or both LNs for controls) from baseline breathing to apnea was measured. The Euclidian differences between the series of each subject and the series of controls and patients classified it into normal or impaired CVR. We found different percent variations on BOLD-signal intensities between groups (P=0.032). The agreement was good in Controls (85.7%; κ=0.69) and overall (77.3%; κ=0.54). We conclude that BHT was feasible for CVR assessment on fMRI and elicited different BOLD responses in patients and controls, with a good overall agreement between the tests.
Eighteen
Xenorhabdus isolates associated with Spanish entomopathogenic nematodes of the genus
Steinernema were characterized using a polyphasic approach including phenotypic and molecular methods. ...Two isolates were classified as
Xenorhabdus nematophila and were associated with
Steinernema carpocapsae. Sixteen isolates were classified as
Xenorhabdus bovienii, of which fifteen were associated with
Steinernema feltiae and one with
Steinernema kraussei. Two
X. bovienii Phase II were also isolated, one instable phase isolated from
S. feltiae strain Rioja and one stable phase from
S. feltiae strain BZ. Four representative bacterial isolates were chosen to study their pathogenicity against
Spodoptera littoralis with and without the presence of their nematode host. The four bacterial isolates were pathogenic for
S. littoralis leading to septicemia 24
h post-injection and killing around 90% of the insect larvae 36
h post-injection, except for that isolated from
S. kraussei. After 48
h of injection, this latter isolate showed a lower final population in the larval hemolymph (10
7 instead of 10
8
CFU per larvae) and a lower larval mortality (70% instead of 95–100%). The virulence of the nematode–bacteria complexes against
S. littoralis showed similar traits with a significant insect larvae mortality (80–90%) 5
days post-infection except for
S. kraussei, although this strain reached similar of larval mortality at 7
days after infection.
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