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1.
BMC Infect Dis ; 21(1): 4, 2021 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-33397312

RESUMO

BACKGROUND: Tuberculous pleural effusion (TPE) is the most common extrapulmonary manifestation and may have lasting effect on lung function. However conventional diagnostic tests for TPE register multiple limitations. This study estimates diagnostic efficacy of the interferon gamma release assay (IGRA: T-SPOT.TB) in TPE patients of different characteristics. METHODS: We performed a prospective, single-centre study including all suspected pleural effusion patients consecutively enrolled from June 2015 to October 2018. Through receiver operating characteristic (ROC) curves, technical cut-offs and the utility of T-SPOT on pleural fluid (PF) were determined and analysed. Logistic regression analysis was performed to obtain the independent risk factors for TPE, and evaluated the performance of the T-SPOT assay stratified by risk factors in comparison to ADA. RESULTS: A total of 601 individuals were consecutively recruited. The maximum spot-forming cells (SFCs) of early secretory antigenic target-6 (ESAT-6) and culture filtrate protein-10 (CFP-10) in the PF T-SPOT assay had the best diagnostic efficiency in our study, which was equal to ADA (0.885 vs 0.887, P = 0.957) and superior to peripheral blood (PB), with a sensitivity of 83.0% and a specificity of 83.1% (The cut-off value was 466 SFCs/106 mononuclear cells). Among the TPE patients with low ADA (< 40 IU/L), the sensitivity and specificity of PF T-SPOT were still 87.9 and 90.5%, respectively. The utility of ADA was negatively related to increasing age, but the PF T-SPOT test had a steady performance at all ages. Age (< 45 yrs.; odds ratio (OR) = 5.61, 95% confidence interval (CI) 3.59-8.78; P < 0.001), gender (male; OR = 2.68, 95% CI 1.75-2.88; P < 0.001) and body mass index (BMI) (< 22; OR = 1.93, 95% CI 1.30-2.88; P = 0.001) were independently associated with the risk of TB by multivariate logistic regression analysis. Notably, when stratified by risk factor, the sensitivity of PF T-SPOT was superior to the sensitivity for ADA (76.5% vs. 23.5%, P = 0.016) and had noninferior specificity (84.4% vs. 96.9%, P = 0.370). CONCLUSIONS: In conclusion, the PF T-SPOT assay can effectively discriminate TPE patients whose ADA is lower than 40 IU/L and is superior to ADA in unconventional TPE patients (age ≥ 45 yrs., female or BMI ≥ 22). The PF T-SPOT assay is an excellent choice to supplement ADA to diagnose TPE.


Assuntos
Adenosina Desaminase/análise , Testes Diagnósticos de Rotina/métodos , Testes de Liberação de Interferon-gama/métodos , Mycobacterium tuberculosis/genética , Derrame Pleural/diagnóstico , Derrame Pleural/epidemiologia , Tuberculose Pleural/diagnóstico , Tuberculose Pleural/epidemiologia , Adenosina Desaminase/sangue , Adulto , Idoso , Pequim/epidemiologia , Exsudatos e Transudatos/química , Exsudatos e Transudatos/microbiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/isolamento & purificação , Derrame Pleural/microbiologia , Prevalência , Estudos Prospectivos , Curva ROC , Fatores de Risco , Sensibilidade e Especificidade , Escarro/química , Escarro/microbiologia , Tuberculose Pleural/microbiologia
2.
Sci Total Environ ; 764: 144436, 2021 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-33401039

RESUMO

Root exudates could influence the bioavailability of polycyclic aromatic hydrocarbons (PAHs), provide nutrients for soil microorganisms, and affect PAH biodegradation. However, it remains unclear how a bacterial community and its PAH-degrading genes play crucial roles in PAH biodegradation and respond to root exudates. In this study, a 32-day soil microcosm study was conducted to explore the impacts of artificial and actual root exudates on PAH degradation, degrading genes, and bacterial community structure. The results showed that 10-100 mg DOC/kg artificial and actual root exudates promoted the degradation of naphthalene, phenanthrene, and pyrene in soils, and their percent removal increased initially and then decreased with the increasing root exudates. Quantitative polymerase chain reaction analysis and 16S rRNA gene high-throughput sequencing suggested that the artificial root exudates significantly promoted the Nocardioides and Arthrobacter genera, which may harbor the nidA gene (the representative PAH-degrading gene from Gram-positive bacteria). In contrast, actual root exudates significantly stimulated the Pseudomonas genus that may harbor the nahAc gene (the representative PAH-degrading gene from Gram-negative bacteria). The correlation analysis further indicated that the absolute abundance of PAH degraders and degrading genes had strong correlations with PAH degradation efficiency. Therefore, these findings suggest that root exudates enhanced PAH biodegradation probably due to increases in abundance of both PAH-degraders and their degrading genes.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes do Solo , Biodegradação Ambiental , Exsudatos e Transudatos/química , Hidrocarbonetos Policíclicos Aromáticos/análise , RNA Ribossômico 16S/genética , Solo , Microbiologia do Solo
3.
Appl Environ Microbiol ; 86(17)2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32591378

RESUMO

The number of sustainable agriculture techniques to improve pest management and environmental safety is rising, as biological control agents are used to enhance disease resistance and abiotic stress tolerance in crops. Here, we investigated the capacity of the Photorhabdus luminescens secondary variant to react to plant root exudates and their behavior toward microorganisms in the rhizosphere. P. luminescens is known to live in symbiosis with entomopathogenic nematodes (EPNs) and to be highly pathogenic toward insects. The P. luminescens-EPN relationship has been widely studied, and this combination has been used as a biological control agent; however, not much attention has been paid to the putative lifestyle of P. luminescens in the rhizosphere. We performed transcriptome analysis to show how P. luminescens responds to plant root exudates. The analysis highlighted genes involved in chitin degradation, biofilm regulation, formation of flagella, and type VI secretion system. Furthermore, we provide evidence that P. luminescens can inhibit growth of phytopathogenic fungi. Finally, we demonstrated a specific interaction of P. luminescens with plant roots. Understanding the role and the function of this bacterium in the rhizosphere might accelerate the progress in biocontrol manipulation and elucidate the peculiar mechanisms adopted by plant growth-promoting rhizobacteria in plant root interactions.IMPORTANCE Insect-pathogenic Photorhabdus luminescens bacteria are widely used in biocontrol strategies against pests. Very little is known about the life of these bacteria in the rhizosphere. Here, we show that P. luminescens can specifically react to and interact with plant roots. Understanding the adaptation of P. luminescens in the rhizosphere is highly important for the biotechnological application of entomopathogenic bacteria and could improve future sustainable pest management in agriculture.


Assuntos
Quimiotaxia , Photorhabdus/fisiologia , Raízes de Plantas/microbiologia , Raízes de Plantas/fisiologia , Rizosfera , Agentes de Controle Biológico , Exsudatos e Transudatos/química , Fungos/fisiologia , Perfilação da Expressão Gênica , Genes Bacterianos , Photorhabdus/genética , RNA-Seq
4.
Am J Med Sci ; 360(3): 236-242, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32423747

RESUMO

BACKGROUND: The etiology of pleural effusions often remained unknown notwithstanding surgical pleural biopsy and further clinical observation. A better understanding of clinical characteristics of patients with idiopathic pleural effusion (IPE) may improve the ability to differentiate between IPEs and cytology-negative malignant pleural effusions (MPEs) and facilitate the identification of patients requiring invasive investigation. However, little is known about the clinical factors that can help distinguish patients with IPE from those with cytology-negative MPE. MATERIALS AND METHODS: Patients who were diagnosed with IPE or cytology-negative MPE between 2010 and 2017 were enrolled in this retrospective study. Clinical, laboratory and radiologic characteristics were compared between patients with IPE and cytology-negative MPE. Diagnostic performances of predictors for IPE were assessed using receiver operating characteristic curves. RESULTS: Of 146 patients undergoing pleural biopsy owing to cytology-negative pleural effusion of uncertain cause, MPE was confirmed in 54 patients. IPE was ultimately diagnosed in 22 patients. Multivariate analysis demonstrated that a minimal amount of pleural effusion (odds ratio [OR] = 12.41, P = 0.039), presence of pleural nodularity (OR = 0.01, P < 0.001) and pleural fluid carcinoembryonic antigen levels less than 14 ng/mL (OR = 87.59, P = 0.002) were independent factors for distinguishing IPEs from cytology-negative MPEs. A combination of the absence of pleural nodularity with pleural fluid carcinoembryonic antigen levels less than 14 ng/mL yielded an area under the curve of 0.94 (sensitivity = 91% and specificity = 96%). CONCLUSIONS: Using these readily available parameters to identify IPE in patients with cytology-negative exudative effusion of unknown cause can help guide decision-making when choosing to perform an invasive pleural biopsy or to take a conservative approach.


Assuntos
Derrame Pleural Maligno/diagnóstico , Derrame Pleural/diagnóstico , Idoso , Biópsia , Antígeno Carcinoembrionário/análise , Diagnóstico Diferencial , Exsudatos e Transudatos/química , Exsudatos e Transudatos/citologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Derrame Pleural/patologia , Derrame Pleural Maligno/patologia , Curva ROC , Radiografia Torácica , Estudos Retrospectivos , Toracentese , Toracoscopia , Tomografia Computadorizada por Raios X
5.
Heart ; 106(7): 541-544, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31422364

RESUMO

OBJECTIVE: Biochemical analysis of pericardial fluid (PF) is commonly performed for the initial assessment of PF, and the results are usually interpreted according to Light's traditional criteria for the differential diagnosis of transudates versus exudates. However, Light's criteria have been formulated for the biochemical analysis of pleural fluid. The aim of the present paper is to evaluate the normal composition of PF in candidates for cardiac surgery. METHODS: Cohort study with analysis of PF from candidates for cardiac surgery. Exclusion criteria were previous pericardial disease or cardiac surgery, prior myocardial infarction within 3 months, systemic disease (eg, systemic inflammatory diseases, uremia) or drug with potentiality to affect the pericardium. RESULTS: Fifty patients (mean age was 67 years; 95% CI 64 to 71, 29 males, 58.0%) were included in the present analysis. Levels of small molecules were similar in blood and PF. Total proteins in PF was, on average, 0.5 times lower than corresponding plasma levels (p=0.041), while the level of pericardial lactate dehydrogenase was, on average, 1.06 times higher than plasma (p=0.55). Moreover, mononuclear cells were more concentrated in PF than plasma (p=0.17). Traditional Light's criteria misclassified all PFs as exudates. CONCLUSIONS: Traditional Light's criteria misclassified normal PFs in candidates for cardiac surgery as exudates. This study suggests their futility for the biochemical analysis of PF in clinical practice.


Assuntos
Líquido Pericárdico/química , Idoso , Testes de Química Clínica , Estudos de Coortes , Exsudatos e Transudatos/química , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
6.
Laryngoscope ; 130(3): 806-811, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31021431

RESUMO

OBJECTIVES: Otitis media with effusion (OME) is a common disease of childhood that is largely asymptomatic. However, middle ear fluid can persist for months and negatively impact a child's quality of life. Many cases of OME remain chronic and require surgical intervention. Because biofilms are known to contribute to the persistence of many diseases, this study examined effusions collected from children with chronic OME for the presence of essential biofilm structural components, members of the DNABII family of bacterial DNA-binding proteins. METHODS: Middle ear effusions were recovered from 38 children with chronic OME at the time of tympanostomy tube insertion. A portion of each specimen was submitted for microbiology culture. The remaining material was assessed by immunoblot to quantitate individual DNABII proteins, integration host factor (IHF), and histone-like protein (HU). RESULTS: Sixty-five percent of effusions (24 of 37) were culture-positive for bacterial species or yeast, whereas 35% (13 of 37) were culture-negative. IHF was detected in 95% (36 of 38) at concentrations from 2 to 481 ng/µL effusion. HU was detected in 95% (36 of 38) and quantitated from 13 to 5,264 ng/µL effusion (P ≤ 0.05 compared to IHF). CONCLUSION: Because DNABII proteins are essential structural components of bacterial biofilms, these data lend further support to our understanding that biofilms are present in the vast majority of chronic middle ear effusions, despite negative culture results. The presence and ubiquity of DNABII proteins in OME specimens indicated that these proteins can serve as an important clinical target for our novel DNABII-directed strategy to treat biofilm diseases such as chronic OME. LEVEL OF EVIDENCE: NA Laryngoscope, 130:806-811, 2020.


Assuntos
Proteínas de Bactérias/análise , Biofilmes , Exsudatos e Transudatos/química , Otite Média com Derrame , Adolescente , Estruturas Bacterianas , Criança , Pré-Escolar , Exsudatos e Transudatos/microbiologia , Feminino , Humanos , Lactente , Masculino , Otite Média com Derrame/microbiologia , Adulto Jovem
7.
Wounds ; 32(1): 22-29, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31730507

RESUMO

INTRODUCTION: Frostbite is well documented in the military and countries with extreme temperatures, and it is most likely due to increased exposure to cold temperatures and/or risk-taking behavior. Severity of injury depends on absolute temperature, wind chill, duration of exposure, wet or dry cold, immersion, clothing quality, and substance use. Hyperbaric oxygen therapy (HBOT) has been described as a treatment option but only in small case series. OBJECTIVE: The aim of this retrospective study is to describe the usage patterns, side effects, and outcomes of HBOT used as an adjunct to wound care at a single major Canadian university hospital. MATERIALS AND METHODS: A retrospective review of patients with frostbite injury admitted and treated with HBOT between January 2000 and March 2015 was performed. A total of 22 patients were studied. Available data included patient demographics, duration of exposure to cold temperature, severity of injury, time to HBOT, duration of therapy, side effects of therapy, concurrent therapies (dressing, anticoagulation, antibiotics), bone scan results, and consequent level of amputation. RESULTS: The cohort consisted mostly of men (18, 81.8%) and patient mean age of 40 years (range, 13-70 years). Ten patients (45.5%) were intoxicated at the time of injury, and psychiatric illness was implicated in 9 (40.9%) patients. Of the presented injuries, 17 (77.3%) had frostbite to the upper extremity. Bone scans were performed on 16 (72.7%) patients. In 4 patients, the absence of radiotracer activity correlated with a protective effect on subsequent amputation levels. All patients received anticoagulant therapy. Of the 22 patients, 16 (72.7%) experienced at least 1 side effect of HBOT, including otologic barotrauma, nausea, vomiting, anxiety, oxygen toxicity seizure, and myopic changes. All study patients recovered without permanent sequelae; it is unclear whether HBOT reduced soft-tissue damage or amputation rates. CONCLUSIONS: This is the largest cohort reported in the literature of patients with frostbite injuries treated with HBOT. Hyperbaric oxygen therapy may show positive impact on the demarcation level of frostbite and, despite the common side effects, it generally causes no long-term sequelae.


Assuntos
Bandagens , Prata/análise , Prata/química , Exsudatos e Transudatos/química , Troca Iônica , Íons/análise , Íons/química , Teste de Materiais , Poliésteres/química , Polietilenos/química , Soroalbumina Bovina/química , Temperatura
8.
Biochem Med (Zagreb) ; 30(1): 010502, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31839720

RESUMO

Extravascular body fluids (EBF) analysis can provide useful information in the differential diagnosis of conditions that caused their accumulation. Their unique nature and particular requirements accompanying EBF analysis need to be recognized in order to minimize possible negative implications on patient safety. This recommendation was prepared by the members of the Working group for extravascular body fluid samples (WG EBFS). It is designed to address the total testing process and clinical significance of tests used in EBF analysis. The recommendation begins with a chapter addressing validation of methods used in EBF analysis, and continues with specific recommendations for serous fluids analysis. It is organized in sections referring to the preanalytical, analytical and postanalytical phase with specific recommendations presented in boxes. Its main goal is to assist in the attainment of national harmonization of serous fluid analysis and ultimately improve patient safety and healthcare outcomes. This recommendation is intended to all laboratory professionals performing EBF analysis and healthcare professionals involved in EBF collection and processing. Cytological and microbiological evaluations of EBF are beyond the scope of this document.


Assuntos
Líquidos Corporais/química , Técnicas de Laboratório Clínico/normas , Líquidos Corporais/metabolismo , Exsudatos e Transudatos/química , Exsudatos e Transudatos/metabolismo , Guias como Assunto , Humanos , Segurança do Paciente , Derrame Pleural/diagnóstico , Garantia da Qualidade dos Cuidados de Saúde , Sociedades Médicas , Manejo de Espécimes/normas
9.
J Bronchology Interv Pulmonol ; 27(1): 4-13, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31373905

RESUMO

BACKGROUND: The behavior of pleural fluid cytokine (PFCs) levels and their association with pleurodesis after indwelling pleural catheter (IPC) placement is unknown. OBJECTIVE: A prospective exploratory study was conducted to obtain preliminary data on PFC levels after IPC placement. METHODS: The PFC panel consisted of 4 cytokines [interleukin -8 (IL-8), vascular endothelial growth factor, total (but not activated) transforming growth factor betas, and basic fibroblast growth factor], measured across 5 time points (T0: insertion; T1: 24 to 48 h; T2: 72 to 96 h; T3: 1 wk; and T4: 2 wk). Profile plots were used to identify patterns of change of PFC levels. Correlation matrices for each PFC over time were computed, and area under the curve (AUC) categories were used to compare the cumulative incidence of IPC removal. Auto pleurodesis was defined as elective catheter removal because of decreased drainage within 90 days of insertion. RESULTS: A total of 22 patients provided complete data. Except for IL-8, the majority of PFCs demonstrated strong positive correlations across measurement time points. Patients with high AUCs for IL-8, basic fibroblast growth factor, and vascular endothelial growth factor had a higher cumulative incidence of IPC removal by 90 days than did patients with low AUCs. CONCLUSION: This is the first study to evaluate longitudinal changes of pleural cytokine levels with respect to the likelihood of IPC removal and provide early evidence that the cytokine profile may be associated with the outcome of pleurodesis induced by IPCs. However, this is an exploratory study and further studies are needed to assess if these findings can be validated in further studies.


Assuntos
Cateteres de Demora , Citocinas/análise , Remoção de Dispositivo , Exsudatos e Transudatos/química , Pleura , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pleurodese , Estudos Prospectivos , Fatores de Tempo , Adulto Jovem
10.
Medicine (Baltimore) ; 98(45): e17843, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31702640

RESUMO

BACKGROUND: Acupuncture therapy is frequently used to treat Knee Osteoarthritis (KOA) in clinic, and usually used local acupoints near the diseased knees as therapeutic targets. Some local acupoints appeared sensitization phenomenon which was called sensitized acupoints, which were regarded as important therapeutic targets to get better therapeutic effect on clinic. Therefore, it is necessary to explore the biological basis of acupoint sensitization. Meanwhile, there is a lack of an analysis of the metabolism for sensitized acupoints in KOA patients. Considering that acupuncture effect could be multi-targeted, omics (such as metabolomics) may be a useful method to reveal the relationship between sensitized acupoints and clinical efficacy of acupuncture. METHODS AND ANALYSIS: This study is a parallel design trial. Thirty KOA patients and 30 healthy volunteers will be recruited in this study. Mechanical pain threshold will be measured by Electron Von frey in order to confirm the highest sensitized acupoints. Then collect tissue fluid from the highest sensitized acupoints by micro dialysis technical, then apply electro-acupuncture method on the highest sensitized acupoints to treat KOA patients, after 20 sessions treatments, measure and collect again. Liquid chromatography-tandem mass spectrometry method will be used to analyze the metabonomics of dialysate. RESULTS: This study will provide a high-quality evidence to reveal the local molecular mechanism of acupuncture sensitized acupoints for patient with KOA. CONCLUSION: This study will provide up-date evidence of whether acupuncture sensitized acupoints have local molecular mechanism for KOA. TRIAL REGISTRATION NUMBER: NCT03599180 (24 Jul. 2018).


Assuntos
Terapia por Acupuntura/métodos , Exsudatos e Transudatos/química , Metabolômica/métodos , Osteoartrite do Joelho/terapia , Pontos de Acupuntura , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Microdiálise , Pessoa de Meia-Idade , Osteoartrite do Joelho/metabolismo , Projetos Piloto
11.
Int J Parasitol ; 49(13-14): 999-1003, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31726058

RESUMO

Plant root exudates are compositionally diverse, plastic and adaptive. Ethylene signalling influences the attraction of plant parasitic nematodes, presumably through the modulation of root exudate composition. Understanding this pathway could lead to new sources of crop parasite resistance. Here we used Virus-Induced Gene Silencing to knock down the expression of two Ethylene Response Factor (ERF) genes, ERF-E2 and ERF-E3, in tomato. Root exudates were significantly more attractive to the PPNs Meloidogyne incognita and Globodera pallida following knockdown of ERF-E2, which had no impact on the attraction of Meloidogyne javanica. Knockdown of ERF-E3 had no impact on the attraction of Meloidogyne or Globodera spp. Gas Chromatography Mass Spectrometry analysis revealed major changes in root exudate composition relative to controls. However, these changes did not alter the attraction of rhizosphere microbes Bacillus subtilis or Agrobacterium tumefaciens. This study further supports the potential of engineering plant root exudate for parasite control, through the modulation of plant genes.


Assuntos
Fatores Biológicos/análise , Proteínas de Ligação a DNA/metabolismo , Etilenos/metabolismo , Exsudatos e Transudatos/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Animais , Proteínas de Ligação a DNA/genética , Exsudatos e Transudatos/química , Cromatografia Gasosa-Espectrometria de Massas , Regulação da Expressão Gênica de Plantas , Técnicas de Silenciamento de Genes , Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Lycopersicon esculentum/parasitologia , Doenças das Plantas/parasitologia , Proteínas de Plantas/genética , Transdução de Sinais , Tylenchoidea/efeitos dos fármacos
12.
Respir Med ; 157: 7-13, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31454675

RESUMO

A chylothorax, also known as chylous pleural effusion, is an uncommon cause of pleural effusion with a wide differential diagnosis characterized by the accumulation of bacteriostatic chyle in the pleural space. The pleural fluid will have either or both triglycerides >110 mg/dL and the presence of chylomicrons. It may be encountered following a surgical intervention, usually in the chest, or underlying disease process. Management of a chylothorax requires a multidisciplinary approach employing medical therapy and possibly surgical intervention for post-operative patients and patients who have failed medical therapy. In this review, we aim to discuss the anatomy, fluid characteristics, etiology, and approach to the diagnosis of a chylothorax.


Assuntos
Quilotórax/etiologia , Derrame Pleural/patologia , Ducto Torácico/lesões , Antineoplásicos Hormonais/uso terapêutico , Quilotórax/diagnóstico por imagem , Quilotórax/terapia , Diagnóstico Diferencial , Exsudatos e Transudatos/química , Exsudatos e Transudatos/citologia , Exsudatos e Transudatos/metabolismo , Humanos , Linfografia/métodos , Linfocintigrafia/métodos , Octreotida/uso terapêutico , Período Pós-Operatório , Radiografia Torácica/métodos , Sucção/métodos , Toracentese/métodos , Ducto Torácico/diagnóstico por imagem , Ducto Torácico/fisiopatologia , Ducto Torácico/cirurgia , Tomografia Computadorizada por Raios X/métodos , Triglicerídeos/análise
14.
Ecotoxicology ; 28(4): 429-434, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30904977

RESUMO

Root exudate autotoxicity (i.e. root exudates from a given plant have toxic effects on itself) has been recognized to be widespread. Here we examined how plant species identity and soil phosphorus (P) availability influenced this autotoxicity and the possible stoichiometric mechanisms. We conducted an experiment with three species (Luctuca sativa, Sesbania cannabina, and Solidago canadensis), which were subject to four treatments consisting of activated carbon (AC) and soil P. AC addition increased the whole-plant biomass of each species under high P conditions and this AC effect varied strongly with species identity. For Solidago, the relative increase in whole-plant biomass due to AC addition was larger in the low P than in the high P. Root exudate autotoxicity differed between roots and shoots. AC addition decreased root N:P ratios but failed to influence shoot N:P ratios in three species. These findings suggest that soil P enrichment might mediate root exudate autotoxicity and that this P-mediated autotoxicity might be related to root N and P stoichiometry. These patterns and their implications need to be addressed in the context of plant communities.


Assuntos
Exsudatos e Transudatos , Alface/efeitos dos fármacos , Fósforo/metabolismo , Raízes de Plantas/química , Sesbania/efeitos dos fármacos , Poluentes do Solo/metabolismo , Solidago/efeitos dos fármacos , Disponibilidade Biológica , Biomassa , Monitoramento Ambiental , Exsudatos e Transudatos/química , Alface/metabolismo , Raízes de Plantas/metabolismo , Sesbania/metabolismo , Solidago/metabolismo
15.
Pest Manag Sci ; 75(9): 2474-2481, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30828973

RESUMO

BACKGROUND: One of the roles of plant trichomes is thought to be reducing feeding damage from herbivores. Among trichomes, glandular trichomes play a role in chemical defense systems in plants by means of stored biologically active phytochemicals. These phytochemicals act as pest repellents. They show antimicrobial and insecticidal activities, and they have also been isolated and identified from wild plants. RESULTS: The Asteraceae species Heterotheca subaxillaris has many glandular trichomes on the leaf surface, and these contain sesquiterpene carboxylates, which show insect antifeedant activity. Because these sesquiterpene carboxylates are major constituents of glandular trichomes, they may act as a chemical defense in H. subaxillaris. The Orobanchaceae species Parentucellia viscosa also has many glandular trichomes on the leaf surface and produces an insect antifeedant clerodane-type diterpene, kolavenic acid, in these trichomes. Additionally, two other Orobanchaceae species, Bellardia trixago and Parentucellia latifolia, also have many glandular trichomes, but the constituents of these glandular trichomes did not show biological activities against test insects. However, the seco-labdane diterpene alcohol trixagol and its hemi-malonate were major constituents in B. trixago, and these terpenes may act as physical defenses against herbivores by interfering with feeding due to their viscosity. CONCLUSION: The secondary metabolites from glandular trichomes of H. subaxillaris and P. viscosa showed insect antifeedant activity, and these secondary metabolites were presumed to act as chemical defenses for these plant species. On the other hand, non-biologically active secondary metabolites produced by two other Orobanchaceae, B. trixago and P. latifolia, were presumed to act as physical defenses due to their viscosity. Defense systems such as these may be applicable to new crop breeding to enhance protection against insect pests. © 2019 Society of Chemical Industry.


Assuntos
Asteraceae/química , Agentes de Controle Biológico/farmacologia , Inseticidas/farmacologia , Orobanchaceae/química , Spodoptera/efeitos dos fármacos , Animais , Agentes de Controle Biológico/química , Exsudatos e Transudatos/química , Inseticidas/química , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Folhas de Planta/química , Spodoptera/crescimento & desenvolvimento , Tricomas/química
17.
Int Wound J ; 16(2): 503-510, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30604928

RESUMO

In this study, we evaluated a new aspect of negative pressure wound therapy (NPWT) as an analytical tool for pharmacokinetic studies. Twenty-one patients with soft tissue defects scheduled to receive NPWT were included in this study. Concomitant to NPWT, all patients received intravenous moxifloxacin (MX). At different time intervals, blood plasma levels of MX were sampled and compared with synchronous concentrations of MX in the exudate obtained from the NPWT drainage system. Serial measurements were performed upon initiation of the therapy as well as in the steady state (after 5 days). At steady state, wound tissue was obtained intraoperatively. High-performance liquid-chromatography (HPLC) was used for analysis. At 1 hour post-administration, the exudate/plasma levels (mg/L) were 1.92/3.07; at 12 hours, 0.80/1.14; at 24 hours, 0.26/0.43; and at 120 hours (steady state), 0.42/0.47. There was a correlation between exudate and plasma levels reaching approximately 0.75. Until now, methods for pharmacokinetic studies concerning interstitial fluid are difficult to apply in the clinical context. The presented method showed limitations, but we believe that, after methodological improvements, measurements of substances in the interstitial fluid by means of NPWT are feasible.


Assuntos
Antibacterianos/análise , Antibacterianos/farmacocinética , Exsudatos e Transudatos/química , Moxifloxacina/análise , Moxifloxacina/farmacocinética , Tratamento de Ferimentos com Pressão Negativa/métodos , Ferimentos e Lesões/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , Feminino , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade , Moxifloxacina/uso terapêutico , Cicatrização/fisiologia
18.
Stroke ; 50(2): 328-335, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30661497

RESUMO

Background and Purpose- Cerebral amyloid angiopathy (CAA) is a common small vessel disease that independently effects cognition in older individuals. The pathophysiology of CAA and CAA-related bleeding remains poorly understood. In this postmortem study, we explored whether blood-brain barrier leakage is associated with CAA and microvascular lesions. Methods- Eleven CAA cases (median [IQR] age=69 years [65-79 years], 8 males) and 7 cases without neurological disease or brain lesions (median [IQR] age=77 years [68-92 years], 4 males) were analyzed. Cortical sections were sampled from each lobe, and IgG and fibrin extravasation (markers of blood-brain barrier leakage) were assessed with immunohistochemistry. We hypothesized that IgG and fibrin extravasation would be increased in CAA cases compared with controls, that this would be more pronounced in parietooccipital brain regions compared with frontotemporal brain regions in parallel with the posterior predilection of CAA, and would be associated with CAA severity and number of cerebral microbleeds and cerebral microinfarcts counted on ex vivo magnetic resonance imaging of the intact brain hemisphere. Results- Our results demonstrated increased IgG positivity in the frontotemporal ( P=0.044) and parietooccipital ( P=0.001) cortex in CAA cases compared with controls. Within CAA cases, both fibrin and IgG positivity were increased in parietooccipital brain regions compared with frontotemporal brain regions ( P=0.005 and P=0.006, respectively). The percentage of positive vessels for fibrin and IgG was associated with the percentage of amyloid-ß-positive vessels (Spearman ρ=0.71, P=0.015 and Spearman ρ=0.73, P=0.011, respectively). Moreover, the percentage of fibrin and IgG-positive vessels, but not amyloid-ß-positive vessels, was associated with the number of cerebral microbleeds on magnetic resonance imaging (Spearman ρ=0.77, P=0.005 and Spearman ρ=0.70, P=0.017, respectively). Finally, we observed fibrin deposition in walls of vessels involved in cerebral microbleeds. Conclusions- Our results raise the possibility that blood-brain barrier leakage may be a contributory mechanism for CAA-related brain injury.


Assuntos
Barreira Hematoencefálica , Angiopatia Amiloide Cerebral/patologia , Idoso , Idoso de 80 Anos ou mais , Peptídeos beta-Amiloides/análise , Autopsia , Proteínas Sanguíneas/análise , Permeabilidade Capilar , Angiopatia Amiloide Cerebral/fisiopatologia , Córtex Cerebral/química , Exsudatos e Transudatos/química , Feminino , Fibrina/análise , Humanos , Imunoglobulina G/análise , Imagem por Ressonância Magnética , Masculino , Microvasos/patologia , Neuroimagem
19.
Environ Microbiol ; 21(1): 402-415, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30421582

RESUMO

Chemotaxis to plant root exudates is supposed to be a prerequisite for efficient root colonization by rhizobacteria. This is a highly multifactorial process since root exudates are complex compound mixtures of which components are recognized by different chemoreceptors. Little information is available as to the key components in root exudates and their receptors that drive colonization related chemotaxis. We present here the first global assessment of this issue using the plant growth-promoting rhizobacterium (PGPR) Bacillus velezensis SQR9 (formerly B. amyloliquefaciens). This strain efficiently colonizes cucumber roots, and here, we show that chemotaxis to cucumber root exudates was essential in this process. We conducted chemotaxis assays using cucumber root exudates at different concentrations, individual exudate components as well as recomposed exudates, taking into account their concentrations detected in root exudates. Results indicated that two key chemoreceptors, McpA and McpC, were essential for root exudate chemotaxis and root colonization. Both receptors possess a broad ligand range and recognize most of the exudate key components identified (malic, fumaric, gluconic and glyceric acids, Lys, Ser, Ala and mannose). The remaining six chemoreceptors did not contribute to exudate chemotaxis. This study provides novel insight into the evolution of the chemotaxis system in rhizobacteria.


Assuntos
Bacillus amyloliquefaciens/metabolismo , Quimiotaxia/fisiologia , Cucumis sativus/crescimento & desenvolvimento , Cucumis sativus/microbiologia , Raízes de Plantas/microbiologia , Exsudatos e Transudatos/química , Desenvolvimento Vegetal
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