RESUMO
Plant parasitic nematodes (PPN) are important pests of numerous agricultural crops especially vegetables, able to cause remarkable yield losses correlated to soil nematode population densities at sowing or transplant. The concern on environmental risks, stemming from the use of chemical pesticides acting as nematicides, compels to their replacement with more sustainable pest control strategies. To verify the effect of aqueous extracts of the agro-industry waste coffee silverskin (CS) and brewers' spent grain (BSG) on the widespread root-knot nematode Meloidogyne incognita, and on the physiology of tomato plants, a pot experiment was carried out in a glasshouse at 25 ± 2 °C. The possible phytotoxicity of CS and BSG extracts was assessed on garden cress seeds. Tomato plants (landrace of Apulia Region) were transplanted in an artificial nematode infested soil with an initial population density of 3.17 eggs and juveniles/mL soil. CS and BSG were applied at rates of 50 and 100 % (1L/pot). Untreated and Fenamiphos EC 240 (nematicide) (0.01 µL a.i./mL soil) treated plants were used as controls. Reactive oxygen species (ROS) and chlorophyll content of tomato plants were estimated during the experiment. CS extract, at both doses, significantly reduced nematode population in comparison to the untreated control, although it was less effective than Fenamiphos. BSG extract did not reduce final nematode population compared to the control. Ten days after the first treatment, CS 100 %, BSG 50 % and BSG 100% elicited the highest ROS values, which considerably affected the growth of tomato plants in comparison to the untreated plants. The control of these pests is meeting with difficulties because of the current national and international regulations in force, which are limiting the use of synthetic nematicides. Therefore, CS extracts could assume economic relevance, as alternative products to be used in sustainable strategies for nematode management.
RESUMO
There is significant variability in the serum concentrations of tacrolimus attained early post transplant due to drug interactions and genomic variation. We evaluated whether tacrolimus concentrations early post transplant correlated with incidence of acute GvHD in 120 consecutive patients allografted with a uniform reduced-intensity conditioning regimen. All patients received standard prophylaxis with oral tacrolimus and IV methotrexate. The primary variable of interest was mean weekly tacrolimus concentrations in the initial 4 weeks post transplant. In multivariate analysis, week 1 tacrolimus concentration was an independent predictor of acute grade 2-4 GvHD (hazard ratio (HR), 0.90; 95% confidence interval (CI), 0.84-0.97; P<0.01). This association was driven by a lower risk of acute grade 2-4 GvHD in patients with week 1 tacrolimus concentrations >12 ng/mL (HR, 0.47; 95% CI, 0.25-0.88; P=0.02). Week 1 tacrolimus concentrations were not associated with chronic GvHD, relapse or overall survival. Lower tacrolimus concentrations at weeks 2, 3 and 4 were not associated with a higher incidence of GvHD. In summary, we found that higher tacrolimus concentrations during the first week after allografting with a reduced-intensity conditioning regimen were associated with significantly reduced risk of acute grade 2-4 GvHD without increasing risk of relapse.
Assuntos
Doença Enxerto-Hospedeiro , Doenças Hematológicas , Transplante de Células-Tronco , Tacrolimo , Condicionamento Pré-Transplante , Doença Aguda , Administração Oral , Adulto , Idoso , Aloenxertos , Feminino , Doença Enxerto-Hospedeiro/sangue , Doença Enxerto-Hospedeiro/mortalidade , Doença Enxerto-Hospedeiro/prevenção & controle , Doenças Hematológicas/sangue , Doenças Hematológicas/mortalidade , Doenças Hematológicas/terapia , Humanos , Masculino , Metotrexato/administração & dosagem , Metotrexato/farmacocinética , Pessoa de Meia-Idade , Tacrolimo/administração & dosagem , Tacrolimo/farmacocinética , Fatores de TempoRESUMO
Soil is unanimously considered as one of the most important sink of heavy metals released by human activities. Heavy metal analysis of natural and polluted soils is generally conducted by the use of atomic absorption spectroscopy (AAS) or inductively coupled plasma optical emission spectroscopy (ICP-OES) on adequately obtained soil extracts. Although in recent years the emergent technique of laser-induced breakdown spectroscopy (LIBS) has been applied widely and with increasing success for the qualitative and quantitative analyses of a number of heavy metals in soil matrices with relevant simplification of the conventional methodologies, the technique still requires further confirmation before it can be applied fully successfully in soil analyses. The main objective of this work was to demonstrate that new developments in LIBS technique are able to provide reliable qualitative and quantitative analytical evaluation of several heavy metals in soils, with special focus on the element chromium (Cr), and with reference to the concentrations measured by conventional ICP spectroscopy. The preliminary qualitative LIBS analysis of five soil samples and one sewage sludge sample has allowed the detection of a number of elements including Al, Ca, Cr, Cu, Fe, Mg, Mn, Pb, Si, Ti, V and Zn. Of these, a quantitative analysis was also possible for the elements Cr, Cu, Pb, V and Zn based on the obtained linearity of the calibration curves constructed for each heavy metal, i.e., the proportionality between the intensity of the LIBS emission peaks and the concentration of each heavy metal in the sample measured by ICP. In particular, a triplet of emission lines for Cr could be used for its quantitative measurement. The consistency of experiments made on various samples was supported by the same characteristics of the laser-induced plasma (LIP), i.e., the typical linear distribution confirming the existence of local thermodynamic equilibrium (LTE) condition, and similar excitation temperatures and comparable electron number density measured for all samples. An index of the anthropogenic contribution of Cr in polluted soils was calculated in comparison to a non-polluted reference soil. Thus, the intensity ratios of the emission lines of heavy metal can be used to detect in few minutes the polluted areas for which a more detailed sampling and analysis can be useful.
Assuntos
Monitoramento Ambiental/métodos , Lasers , Metais Pesados/análise , Poluentes do Solo/análise , Análise Espectral/métodos , Cromo/análise , Humanos , Itália , Sensibilidade e Especificidade , Esgotos/química , Espectrofotometria Atômica , Análise Espectral/instrumentação , Análise Espectral/normasRESUMO
Sphagnum peat has been found to efficiently remove heavy metals, oil, detergents, dyes, pesticides and nutrients from contaminated waters since its major constituents, i.e., unesterified polyuronic acids, cellulose, and fulvic and humic acids (HA), show functional groups (e.g., alcohols, aldehydes, carboxylic acids, ketones and phenolic hydroxides) which may adsorb pollutant species. The influence of the extractant on the analytical characteristics of HA is an old but still open topic that should be studied in relation to the nature of the matrix from which they originate. While a number of works have been published on the effects of different reagents on the extraction yields and structural properties of HA from soils, relatively little attention has been devoted to peat HA. In this work, the contents of some major and trace elements (As, Ca, Cr, K, Mn, Sr, and Ti) in five Sphagnum-peat samples and in their corresponding HA fractions isolated using three common extractant solutions, i.e., 0.5M NaOH, 0.1M Na(4)P(2)O(7), and 0.5M NaOH+0.1M Na(4)P(2)O(7), where investigated by X-ray fluorescence spectroscopy. In general, Cr, Mn, and Ti concentrations of bulk peat samples were higher than those of the corresponding HA fractions regardless of the extractant used. Arsenic, Ca, K, and Sr concentrations in the HA fractions were affected by the extraction procedure, although at different extents depending on the extractant utilized. In particular, compared to both NaOH and NaOH+Na(4)P(2)O(7), the Na(4)P(2)O(7) extractant yielded HA generally richer in As, Ca, K, and Sr, and poorer in Ti. These results may be related to both the nature of each HA fraction and the physical and chemical form of each element supplied to the studied bog via atmospheric deposition.
Assuntos
Substâncias Húmicas/análise , Metais Pesados/análise , Solo/análise , Difosfatos/química , Hidróxido de Sódio/química , SoluçõesRESUMO
Pteleopsis suberosa Engl. et Diels (Combretaceae) is a tree distributed in many African countries. The decoction from the stem bark is orally administered for the treatment of gastric ulcers in traditional medicine. Previous pharmacological studies reported the anti-ulcer activity of extracts from P. suberosa stem bark. In the present study, the anti-ulcer and anti-inflammatory effects of the n-butanol fraction (RBuOH) obtained from a methanol extract of P. suberosa bark were investigated on ethanol-induced gastric ulcers in rats and carrageenan-induced paw oedema in mice. Misoprostol (0.50 mg/kg, p.o.) and indomethacin (8.00 mg/kg, p.o.) were used as positive controls for anti-ulcer and anti-inflammatory activities, respectively. Results showed that RBuOH treatment significantly reduced the incidence of gastric lesions (50 mg/kg, P<0.05; 100 and 200 mg/kg, P<0.01) and restored the decreased levels of total sulfhydryl groups (T-SH) and non-protein sulfhydryl groups (NP-SH) (50, 100 mg/kg, P<0.05; 200 mg/kg, P<0.01) in the stomach homogenate. Moreover, RBuOH treatment attenuated MDA levels as index of lipid peroxidation in gastric mucosa. Administration of RBuOH at the same dosage (50, 100 and 200 mg/kg) reduced significantly (P<0.01) carrageenan-induced paw oedema in dose-dependent manner (from 42.81% to 87.81% inhibition, 5h after carrageenan injection). The anti-inflammatory effect of RBuOH at 200 mg/kg was comparable with that of indomethacin. Finally, RBuOH proved to possess elevated free radical scavenger capacity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay (IC(50) 23.48 microg/ml) which may contribute to the observed anti-ulcer and anti-inflammatory activities.
Assuntos
Anti-Inflamatórios/farmacologia , Antiulcerosos/farmacologia , Antioxidantes/farmacologia , Combretaceae/química , Extratos Vegetais/farmacologia , Animais , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/isolamento & purificação , Antiulcerosos/administração & dosagem , Antiulcerosos/isolamento & purificação , Antioxidantes/administração & dosagem , Antioxidantes/isolamento & purificação , Relação Dose-Resposta a Droga , Radicais Livres/metabolismo , Indometacina/farmacologia , Inflamação/tratamento farmacológico , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Camundongos , Misoprostol/farmacologia , Casca de Planta/química , Extratos Vegetais/administração & dosagem , Ratos , Ratos Wistar , Úlcera Gástrica/tratamento farmacológico , Compostos de SulfidrilaRESUMO
Among several extractants used to isolate humic acids (HA) from terrestrial environments, sodium hydroxide (NaOH) and sodium pyrophosphate (Na(4)P(2)O(7)) are the most utilized. In order to evaluate the influence of these different extractant solutions on the HA quality and on their trace elements content, HA were isolated from five Sphagnum-peat samples using three different solutions: (a) 0.5M NaOH; (b) 0.1M Na(4)P(2)O(7); (c) 0.5M NaOH+0.1M Na(4)P(2)O(7). The obtained HA have been analyzed with respect to ash content, elemental composition, main atomic ratios and characterized by FT-IR and total luminescence (TL) spectroscopies. In addition, both raw peat and HA have been analyzed using X-ray fluorescence in order to determine the Br, Cu, Fe, Ni, Pb and Zn contents. Results showed that HA extracted with NaOH and NaOH+Na(4)P(2)O(7) are quite similar with respect to ash, elemental contents and spectroscopic characteristics, while Na(4)P(2)O(7) solution, which in general reduces the extraction yield, seems to affect the nature of HA, featuring a more complex and aromatic character. With respect to the contents in the corresponding raw peat samples, the HA fractions were richer in Br, Cu and Ni, regardless of the extractant used, and poorer in Fe, Pb and Zn. Further, Br, Cu, Ni and Zn were more concentrated in HA extracted with Na(4)P(2)O(7) than in those extracted with NaOH and NaOH+Na(4)P(2)O(7), probably because of the greater affinity of these elements for these more aromatic humic molecules.