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1.
Artigo em Inglês | MEDLINE | ID: mdl-38637214

RESUMO

The anatomically complex craniofacial skeleton demands special consideration when caring for cases of polytrauma or medically compromised patients with craniofacial fractures. This paper utilises a systematic review and multidisciplinary opinions to create an algorithm for the hospital-based care of patients with craniofacial fractures (base of skull, orbit, paranasal sinus, and mandible) who require non-invasive ventilation (NIV). Each fracture location has a unique predisposition to a different type of emphysema and associated morbidity. The risk of developing emphysema, combined with its potential severity, is stratified against the harm of not providing NIV for the holistic care of the patient. The aim of this paper is to synthesise evidence from a systematic review of existing literature with multidisciplinary opinions to develop a concise algorithm that outlines the optimal treatment of patients with craniofacial fractures who require NIV.

2.
Health Phys ; 122(6): 673-684, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35394472

RESUMO

ABSTRACT: Presented are design considerations for a potential detection and measurement technique that could provide operational awareness of high power microwave (HPM) directed energy weapon exposure for force health protection applications, leveraging thermoacoustic (TA) wave generation as the field interaction mechanism. The HPM electromagnetic frequency (EMF) regime, used in applications in both the counter-materiel and non-lethal counter-personnel design space, presents real-time personnel exposure warning challenges due to the potentially wide variation in time and frequency domain characteristics of the incident beam. As with other EM-thermal interactions, the thermoacoustic wave effect provides the potential to determine EM energy and power deposition without the need to measure ambient field intensity values or overload-sensitive EMF survey equipment. Following measurement of relevant EM, thermal, and elastic material property values, a carbon-filled polytetrafluoroethylene (CF-PTFE) lossy dielectric medium subject to pulsed HPM was computationally modeled using the commercial finite element method multi-physics simulation software package COMSOL. The simulation was used to explore the impacts of various material properties on TA signal output as a function of simulated incident field power density, EM frequency, and pulse length, thereby informing the selection of system components for the further development of a full TA-based HPM detection chain.


Assuntos
Micro-Ondas , Polímeros , Simulação por Computador
3.
Pathogens ; 10(11)2021 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-34832546

RESUMO

We conducted an experimental evaluation of treatments to limit Heterobasidion occidentale infection of white fir (Abies concolor) stumps and wounds in California mixed conifer forests. We tested the efficacy of urea, borate, and a mixture of two locally collected Phlebiopsis gigantea strains in preventing pathogen colonization of fir stumps and separately, urea and borate as infection controls on experimental stem wounds. These were paired with a laboratory test on ~100 g wood blocks with and without a one-week delay between inoculation and treatment. Urea, borates, and Phlebiopsis treatments all significantly reduced the stump surface area that was colonized by H. occidentale at 84%, 91%, and 68%, respectively, relative to the controls. However, only the borate treatments significantly lowered the number of stumps that were infected by the pathogen. The laboratory study matched the patterns that were found in the stump experiment with a reduced area of colonization for urea, borates, or P. gigantea treatments relative to the controls; delaying the treatment did not affect efficacy. The field wound experiment did not result in any Heterobasidion colonization, even in positive control treatments, rendering the experiment uninformative. Our study suggests treatments that are known to limit Heterobasidion establishment on pine or spruce stumps elsewhere in the world may also be effective on true firs in California.

4.
Microorganisms ; 8(6)2020 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-32580470

RESUMO

It is commonly assumed that asexual lineages are short-lived evolutionarily, yet many asexual organisms can generate genetic and phenotypic variation, providing an avenue for further evolution. Previous work on the asexual plant pathogen Phytophthora ramorum NA1 revealed considerable genetic variation in the form of Structural Variants (SVs). To better understand how SVs arise and their significance to the California NA1 population, we studied the evolutionary histories of SVs and the forest conditions associated with their emergence. Ancestral state reconstruction suggests that SVs arose by somatic mutations among multiple independent lineages, rather than by recombination. We asked if this unusual phenomenon of parallel evolution between isolated populations is transmitted to extant lineages and found that SVs persist longer in a population if their genetic background had a lower mutation load. Genetic parallelism was also found in geographically distant demes where forest conditions such as host density, solar radiation, and temperature, were similar. Parallel SVs overlap with genes involved in pathogenicity such as RXLRs and have the potential to change the course of an epidemic. By combining genomics and environmental data, we identified an unexpected pattern of repeated evolution in an asexual population and identified environmental factors potentially driving this phenomenon.

5.
Philos Trans R Soc Lond B Biol Sci ; 374(1776): 20180283, 2019 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-31104598

RESUMO

Epidemiological models are powerful tools for evaluating scenarios and visualizing patterns of disease spread, especially when comparing intervention strategies. However, the technical skill required to synthesize and operate computational models frequently renders them beyond the command of the stakeholders who are most impacted by the results. Participatory modelling (PM) strives to restructure the power relationship between modellers and the stakeholders who rely on model insights by involving these stakeholders directly in model development and application; yet, a systematic literature review indicates little adoption of these techniques in epidemiology, especially plant epidemiology. We investigate the potential for PM to integrate stakeholder and researcher knowledge, using Phytophthora ramorum and the resulting sudden oak death disease as a case study. Recent introduction of a novel strain (European 1 or EU1) in southwestern Oregon has prompted significant concern and presents an opportunity for coordinated management to minimize regional pathogen impacts. Using a PM framework, we worked with local stakeholders to develop an interactive forecasting tool for evaluating landscape-scale control strategies. We find that model co-development has great potential to empower stakeholders in the design, development and application of epidemiological models for disease control. This article is part of the theme issue 'Modelling infectious disease outbreaks in humans, animals and plants: epidemic forecasting and control'. This theme issue is linked with the earlier issue 'Modelling infectious disease outbreaks in humans, animals and plants: approaches and important themes'.


Assuntos
Doenças Transmissíveis Emergentes , Previsões , Modelos Biológicos , Doenças das Plantas/prevenção & controle
6.
Phytopathology ; 109(5): 760-769, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30303771

RESUMO

Invasive forest pathogens can harm cultural, economic, and ecological resources. Here, we demonstrate the potential of endemic tree pathogen resistance in forest disease management using Phytophthora ramorum, cause of sudden oak death, in the context of management of tanoak (Notholithocarpus densiflorus), an ecologically unique and highly valued tree within Native American communities of northern California and southern Oregon in the United States. We surveyed resistance to P. ramorum on the Hoopa Valley Indian Reservation and Yurok Indian Reservation in a set of study sites with variable management intensities. Variation in resistance was found at all sites with similar mean and variation across stands, and resistance tended to have a random spatial distribution within stands but was not associated with previous stand management (thinning or prescribed fire) or structural characteristics such as tree density, basal area, or pairwise relatedness among study trees. These results did not suggest host, genetic, management, or environment interactions that could be easily leveraged into treatments to increase the prevalence of resistant trees. We applied epidemiological models to assess the potential application of endemic resistance in this system and to examine our assumption that in planta differences in lesion size-our measure of resistance-reflect linkages between mortality and transmission (resistance) versus reduced mortality with no change in transmission (tolerance). This assumption strongly influenced infection dynamics but changes in host populations-our conservation focus-was dependent on community-level variation in transmission. For P. ramorum, slowing mortality rates (whether by resistance or tolerance) conserves host resources when a second source of inoculum is present; these results are likely generalizable to pathogens with a broader host range. However, when the focal host is the sole source of inoculum, increasing tolerant individuals led to the greatest stand-level pathogen accumulation in our model. When seeking to use variation in mortality rates to affect conservation strategies, it is important to understand how these traits are linked with transmission because tolerance will be more useful for management in mixed-host stands that are already invaded, compared with single-host stands with low or no pathogen presence, where resistance will have the greatest conservation benefits.


Assuntos
Fagaceae/microbiologia , Phytophthora/patogenicidade , Doenças das Plantas/microbiologia , California , Conservação dos Recursos Naturais , Resistência à Doença , Oregon , Árvores/microbiologia
7.
New Phytol ; 218(1): 15-28, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29488280

RESUMO

Accumulating evidence highlights increased mortality risks for trees during severe drought, particularly under warmer temperatures and increasing vapour pressure deficit (VPD). Resulting forest die-off events have severe consequences for ecosystem services, biophysical and biogeochemical land-atmosphere processes. Despite advances in monitoring, modelling and experimental studies of the causes and consequences of tree death from individual tree to ecosystem and global scale, a general mechanistic understanding and realistic predictions of drought mortality under future climate conditions are still lacking. We update a global tree mortality map and present a roadmap to a more holistic understanding of forest mortality across scales. We highlight priority research frontiers that promote: (1) new avenues for research on key tree ecophysiological responses to drought; (2) scaling from the tree/plot level to the ecosystem and region; (3) improvements of mortality risk predictions based on both empirical and mechanistic insights; and (4) a global monitoring network of forest mortality. In light of recent and anticipated large forest die-off events such a research agenda is timely and needed to achieve scientific understanding for realistic predictions of drought-induced tree mortality. The implementation of a sustainable network will require support by stakeholders and political authorities at the international level.


Assuntos
Secas , Florestas , Árvores/fisiologia , Previsões , Geografia , Modelos Teóricos , Probabilidade
8.
Nat Ecol Evol ; 1(9): 1285-1291, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29046541

RESUMO

Widespread tree mortality associated with drought has been observed on all forested continents and global change is expected to exacerbate vegetation vulnerability. Forest mortality has implications for future biosphere-atmosphere interactions of carbon, water and energy balance, and is poorly represented in dynamic vegetation models. Reducing uncertainty requires improved mortality projections founded on robust physiological processes. However, the proposed mechanisms of drought-induced mortality, including hydraulic failure and carbon starvation, are unresolved. A growing number of empirical studies have investigated these mechanisms, but data have not been consistently analysed across species and biomes using a standardized physiological framework. Here, we show that xylem hydraulic failure was ubiquitous across multiple tree taxa at drought-induced mortality. All species assessed had 60% or higher loss of xylem hydraulic conductivity, consistent with proposed theoretical and modelled survival thresholds. We found diverse responses in non-structural carbohydrate reserves at mortality, indicating that evidence supporting carbon starvation was not universal. Reduced non-structural carbohydrates were more common for gymnosperms than angiosperms, associated with xylem hydraulic vulnerability, and may have a role in reducing hydraulic function. Our finding that hydraulic failure at drought-induced mortality was persistent across species indicates that substantial improvement in vegetation modelling can be achieved using thresholds in hydraulic function.


Assuntos
Carbono/deficiência , Secas , Transpiração Vegetal/fisiologia , Árvores/fisiologia , Xilema/fisiologia , Mudança Climática , Cycadopsida/fisiologia , Magnoliopsida/fisiologia , Dinâmica Populacional , Estresse Fisiológico
9.
New Phytol ; 215(4): 1314-1332, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28649741

RESUMO

Contents 1314 I. 1315 II. 1316 III. 1322 IV. 1323 V. 1325 VI. 1326 VII. 1326 VIII. 1327 1328 References 1328 SUMMARY: Invasions of alien plants are typically studied as invasions of individual species, yet interactions between plants and symbiotic fungi (mutualists and potential pathogens) affect plant survival, physiological traits, and reproduction and hence invasion success. Studies show that plant-fungal associations are frequently key drivers of plant invasion success and impact, but clear conceptual frameworks and integration across studies are needed to move beyond a series of case studies towards a more predictive understanding. Here, we consider linked plant-fungal invasions from the perspective of plant and fungal origin, simplified to the least complex representations or 'motifs'. By characterizing these interaction motifs, parallels in invasion processes between pathogen and mutualist fungi become clear, although the outcomes are often opposite in effect. These interaction motifs provide hypotheses for fungal-driven dynamics behind observed plant invasion trajectories. In some situations, the effects of plant-fungal interactions are inconsistent or negligible. Variability in when and where different interaction motifs matter may be driven by specificity in the plant-fungal interaction, the size of the effect of the symbiosis (negative to positive) on plants and the dependence (obligate to facultative) of the plant-fungal interaction. Linked plant-fungal invasions can transform communities and ecosystem function, with potential for persistent legacies preventing ecosystem restoration.


Assuntos
Fungos/patogenicidade , Plantas/microbiologia , Ecossistema , Fungos/fisiologia , Especificidade de Hospedeiro , Interações Hospedeiro-Patógeno/fisiologia , Simbiose
11.
Prim Dent J ; 6(3): 51-55, 2017 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-30188317

RESUMO

There are a number of conditions that can present as a lump on the face. The general dental practitioner is uniquely trained in head and neck anatomy and pathology and should be able to identify these important conditions and consider appropriate investigations. Understanding what requires urgent specialist assessment and what can be referred routinely can be difficult, but is crucial to high quality patient outcomes. This article aims to simplify common conditions that may present as a lump on the face or be an incidental finding within the primary dental care setting. It is by no means an exhaustive description of all the pathology that may be encountered within this anatomical region, however it should form a useful and practical framework for common presentations.


Assuntos
Face , Neoplasias de Cabeça e Pescoço/diagnóstico , Dermatopatias/diagnóstico , Doenças Estomatognáticas/diagnóstico , Diagnóstico Diferencial , Odontologia Geral , Humanos
12.
Oecologia ; 182(1): 265-76, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27164911

RESUMO

Fire and forest disease have significant ecological impacts, but the interactions of these two disturbances are rarely studied. We measured soil C, N, Ca, P, and pH in forests of the Big Sur region of California impacted by the exotic pathogen Phytophthora ramorum, cause of sudden oak death, and the 2008 Basin wildfire complex. In Big Sur, overstory tree mortality following P. ramorum invasion has been extensive in redwood and mixed evergreen forests, where the pathogen kills true oaks and tanoak (Notholithocarpus densiflorus). Sampling was conducted across a full-factorial combination of disease/no disease and burned/unburned conditions in both forest types. Forest floor organic matter and associated nutrients were greater in unburned redwood compared to unburned mixed evergreen forests. Post-fire element pools were similar between forest types, but lower in burned-invaded compared to burned-uninvaded plots. We found evidence disease-generated fuels led to increased loss of forest floor C, N, Ca, and P. The same effects were associated with lower %C and higher PO4-P in the mineral soil. Fire-disease interactions were linear functions of pre-fire host mortality which was similar between the forest types. Our analysis suggests that these effects increased forest floor C loss by as much as 24.4 and 21.3 % in redwood and mixed evergreen forests, respectively, with similar maximum losses for the other forest floor elements. Accumulation of sudden oak death generated fuels has potential to increase fire-related loss of soil nutrients at the region-scale of this disease and similar patterns are likely in other forests, where fire and disease overlap.


Assuntos
Carbono , Solo , Incêndios , Florestas , Phytophthora , Doenças das Plantas , Árvores
13.
Proc Natl Acad Sci U S A ; 113(20): 5640-5, 2016 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-27140631

RESUMO

Sudden oak death, caused by Phytophthora ramorum, has killed millions of oak and tanoak in California since its first detection in 1995. Despite some localized small-scale management, there has been no large-scale attempt to slow the spread of the pathogen in California. Here we use a stochastic spatially explicit model parameterized using data on the spread of P. ramorum to investigate whether and how the epidemic can be controlled. We find that slowing the spread of P. ramorum is now not possible, and has been impossible for a number of years. However, despite extensive cryptic (i.e., presymptomatic) infection and frequent long-range transmission, effective exclusion of the pathogen from large parts of the state could, in principle, have been possible were it to have been started by 2002. This is the approximate date by which sufficient knowledge of P. ramorum epidemiology had accumulated for large-scale management to be realistic. The necessary expenditure would have been very large, but could have been greatly reduced by optimizing the radius within which infected sites are treated and careful selection of sites to treat. In particular, we find that a dynamic strategy treating sites on the epidemic wave front leads to optimal performance. We also find that "front loading" the budget, that is, treating very heavily at the start of the management program, would greatly improve control. Our work introduces a framework for quantifying the likelihood of success and risks of failure of management that can be applied to invading pests and pathogens threatening forests worldwide.


Assuntos
Florestas , Phytophthora , Doenças das Plantas/terapia , Quercus/parasitologia , California , Epidemias , Doenças das Plantas/prevenção & controle , Risco , Fatores de Tempo
14.
Ecol Modell ; 324: 28-32, 2016 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-27019546

RESUMO

Plant and animal disease outbreaks have significant ecological and economic impacts. The spatial extent of control is often informed solely by administrative geography - for example, quarantine of an entire county or state once an invading disease is detected - with little regard for pathogen epidemiology. We present a stochastic model for the spread of a plant pathogen that couples spread in the natural environment and transmission via the nursery trade, and use it to illustrate that control deployed according to administrative boundaries is almost always sub-optimal. We use sudden oak death (caused by Phytophthora ramorum) in mixed forests in California as motivation for our study, since the decision as to whether or not to deploy plant trade quarantine is currently undertaken on a county-by-county basis for that system. However, our key conclusion is applicable more generally: basing management of any disease entirely upon administrative borders does not balance the cost of control with the possible economic and ecological costs of further spread in the optimal fashion.

15.
Ann Thorac Surg ; 97(2): 588-95, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24360089

RESUMO

BACKGROUND: Endovascular treatments of Stanford type B aortic dissection may help to promote aortic remodeling and reduce the incidence of aortic-related complications. The aim of this study was to review published literature describing aortic remodeling after endovascular treatment of aortic dissection. METHODS: A systematic review of the literature was performed which was compliant with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The type of aortic morphology measurements made and the methods used to make them were characterized. The endpoints of interest were the change in these measurements over time. RESULTS: After initial screening, 77 articles were identified; 16 of which met the inclusion criteria. Few studies used three-dimensional reconstruction software and none had validated their measurement protocol. True lumen (TL) and false lumen (FL) diameters, areas, and in some cases volumes were measured. Studies assessed the aorta at a variety of different levels and over different periods of follow-up. Acute dissection patients displayed more consistent degree of remodeling (thoracic FL thrombosis in 80% to 90%) than chronic dissection patients (38% to 91%). Less remodeling was seen below the diaphragm in both groups. CONCLUSIONS: Aortic remodeling after treatment for dissection is described in a highly heterogeneous manner. Despite this there appears to be a greater degree of complete FL resolution in patients with acute dissection than chronic. Factors such as length of aortic coverage and timing of treatment may explain the variation seen in the chronic dissection group. Consensus-based reporting standards are required to synthesize evidence and inform clinical decisions regarding patient selection and operative timing.


Assuntos
Aneurisma da Aorta Torácica/cirurgia , Dissecção Aórtica/cirurgia , Procedimentos Endovasculares/métodos , Dissecção Aórtica/classificação , Aneurisma da Aorta Torácica/classificação , Humanos , Resultado do Tratamento
17.
New Phytol ; 200(2): 422-431, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23790136

RESUMO

Few studies have quantified pathogen impacts to ecosystem processes, despite the fact that pathogens cause or contribute to regional-scale tree mortality. We measured litterfall mass, litterfall chemistry, and soil nitrogen (N) cycling associated with multiple hosts along a gradient of mortality caused by Phytophthora ramorum, the cause of sudden oak death. In redwood forests, the epidemiological and ecological characteristics of the major overstory species determine disease patterns and the magnitude and nature of ecosystem change. Bay laurel (Umbellularia californica) has high litterfall N (0.992%), greater soil extractable NO3 -N, and transmits infection without suffering mortality. Tanoak (Notholithocarpus densiflorus) has moderate litterfall N (0.723%) and transmits infection while suffering extensive mortality that leads to higher extractable soil NO3 -N. Redwood (Sequoia sempervirens) has relatively low litterfall N (0.519%), does not suffer mortality or transmit the pathogen, but dominates forest biomass. The strongest impact of pathogen-caused mortality was the potential shift in species composition, which will alter litterfall chemistry, patterns and dynamics of litterfall mass, and increase soil NO3 -N availability. Patterns of P. ramorum spread and consequent mortality are closely associated with bay laurel abundances, suggesting this species will drive both disease emergence and subsequent ecosystem function.


Assuntos
Interações Hospedeiro-Patógeno , Ciclo do Nitrogênio , Phytophthora/fisiologia , Doenças das Plantas/parasitologia , Quercus/fisiologia , Umbellularia/fisiologia , Carbono/metabolismo , Ecologia , Ecossistema , Nitrogênio/metabolismo , Quercus/parasitologia , Estações do Ano , Sequoia/parasitologia , Sequoia/fisiologia , Solo/química , Especificidade da Espécie , Árvores , Umbellularia/parasitologia
18.
J Gastrointest Surg ; 16(10): 1993-2004, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22810297

RESUMO

BACKGROUND: Appendectomy is one of the most common emergency operations performed in the pediatric population. The aim of this pooled analysis is to compare the outcome from complicated appendicitis (CA) and uncomplicated appendicitis (UA) following laparoscopic appendectomy (LA) and open appendectomy (OA) in children. METHODS: A systematic literature search was performed. Primary outcome measures were incidence of complications, intra-abdominal abscess, and wound infection. Secondary outcomes were length of operation, length of hospital stay, incidence of bowel obstruction, and readmission. RESULTS: Seventy-three thousand one hundred fifty appendectomies for UA and 34,474 appendectomies for CA were included. For UA, the only significant difference between the groups was a reduced length of hospital stay following LA. LA in CA was associated with reduced complications (pooled odds ratio [POR] = 0.53; P < 0.05), wound infections (POR = 0.42; P < 0.05), length of hospital stay (WMD = -0.67; P < 0.05), and bowel obstruction episodes (POR = 0.8; P < 0.05), but an increased incidence of intra-abdominal abscess and length of operation. CONCLUSION: Pooled analysis demonstrates that, in children with uncomplicated acute appendicitis, LA is associated with a reduced hospital stay but broad equivalence in postoperative morbidity when compared with the conventional approach. Although overall morbidity is reduced when the laparoscopic approach is utilized, in cases of CA, the risk of intra-abdominal abscess is increased.


Assuntos
Apendicectomia/métodos , Apendicite/cirurgia , Laparoscopia , Abscesso Abdominal/epidemiologia , Abscesso Abdominal/etiologia , Apendicite/complicações , Criança , Humanos , Incidência , Tempo de Internação/estatística & dados numéricos , Duração da Cirurgia , Readmissão do Paciente/estatística & dados numéricos , Complicações Pós-Operatórias/epidemiologia , Resultado do Tratamento
19.
PLoS Comput Biol ; 8(1): e1002328, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22241973

RESUMO

Exotic pathogens and pests threaten ecosystem service, biodiversity, and crop security globally. If an invasive agent can disperse asymptomatically over long distances, multiple spatial and temporal scales interplay, making identification of effective strategies to regulate, monitor, and control disease extremely difficult. The management of outbreaks is also challenged by limited data on the actual area infested and the dynamics of spatial spread, due to financial, technological, or social constraints. We examine principles of landscape epidemiology important in designing policy to prevent or slow invasion by such organisms, and use Phytophthora ramorum, the cause of sudden oak death, to illustrate how shortfalls in their understanding can render management applications inappropriate. This pathogen has invaded forests in coastal California, USA, and an isolated but fast-growing epidemic focus in northern California (Humboldt County) has the potential for extensive spread. The risk of spread is enhanced by the pathogen's generalist nature and survival. Additionally, the extent of cryptic infection is unknown due to limited surveying resources and access to private land. Here, we use an epidemiological model for transmission in heterogeneous landscapes and Bayesian Markov-chain-Monte-Carlo inference to estimate dispersal and life-cycle parameters of P. ramorum and forecast the distribution of infection and speed of the epidemic front in Humboldt County. We assess the viability of management options for containing the pathogen's northern spread and local impacts. Implementing a stand-alone host-free "barrier" had limited efficacy due to long-distance dispersal, but combining curative with preventive treatments ahead of the front reduced local damage and contained spread. While the large size of this focus makes effective control expensive, early synchronous treatment in newly-identified disease foci should be more cost-effective. We show how the successful management of forest ecosystems depends on estimating the spatial scales of invasion and treatment of pathogens and pests with cryptic long-distance dispersal.


Assuntos
Ecossistema , Modelos Biológicos , Doenças das Plantas/prevenção & controle , Doenças das Plantas/parasitologia , Árvores/parasitologia , California , Simulação por Computador
20.
Eur Arch Otorhinolaryngol ; 269(11): 2415-22, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22274693

RESUMO

Salvage laryngectomy carries a high risk of post-operative infection with reported rates of 40-61%. The purpose of this study was to analyse infections in our own patients and review the potential impact of our current antibiotic prophylaxis (AP). A retrospective analysis of infection in 26 consecutive patients between 2000 and 2010 undergoing salvage total laryngectomy (SL) following recurrent laryngeal cancer after failed radiotherapy or chemo-radiation was undertaken. The antibiotic prophylaxis was intravenous teicoplanin, cefuroxime and metronidazole at induction and for the following 24 h. Infection was defined by Tabet and Johnson's grade 5, categorized as pharyngocutaneous fistula. Fifteen patients (58%) developed a post-operative wound infection, which occurred on average at 12 days after surgery. Univariate analysis demonstrated three risk variables that had a significant correlation with infection: alcohol consumption (p = 0.01), cN stage of tumour (p < 0.01), and pre-operative albumin levels <3.2 g/L (p = 0.012). There was a trend, though not significant, for increased infection in patients with high or low BMIs. The most common organisms isolated from clinical samples from infected patients were methicillin-resistant Staphylococcus aureus MRSA (43%), Pseudomonas aeruginosa (36%), Serratia marcescens, Proteus mirabilis and Enterococcus faecalis (7% each). All these organisms are typical hospital-acquired pathogens. Pseudomonas and Serratia were not covered by the prophylactic regime we used. The current antibiotic regime following SL is inadequate as the rate of infection is high. It would therefore seem logical to trial a separate antibiotic protocol of AP for patients undergoing SL that would include an extended course of antibiotics after the standard prophylaxis. In addition, infection rates may also be reduced by improving the metabolic state of patients pre-operatively by multi-disciplinary action. Steps should also be taken to reduce cross-infection with nosocomial pathogens in these patients. Other aspects of surgical management should be also taken in consideration.


Assuntos
Antibacterianos/uso terapêutico , Antibioticoprofilaxia , Cefuroxima/uso terapêutico , Neoplasias Laríngeas/cirurgia , Laringectomia , Metronidazol/uso terapêutico , Infecção da Ferida Cirúrgica/prevenção & controle , Teicoplanina/uso terapêutico , Administração Intravenosa , Estudos de Coortes , Fístula Cutânea/etiologia , Fístula Cutânea/prevenção & controle , Quimioterapia Combinada , Enterococcus faecalis , Feminino , Fístula/etiologia , Fístula/prevenção & controle , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Doenças Faríngeas/etiologia , Doenças Faríngeas/prevenção & controle , Proteus mirabilis , Pseudomonas aeruginosa , Estudos Retrospectivos , Serratia marcescens , Infecção da Ferida Cirúrgica/complicações , Infecção da Ferida Cirúrgica/microbiologia
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