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1.
The objective of this study comprises of developing novel co-spray dried rifampicin phospholipid lipospheres (SDRPL) to investigate its influence on rifampicin solubility and oral bioavailability. Solid-state techniques were employed to characterize the liposphere formulation. SDRPL solubility was determined in distilled water. BACTEC 460TB System was employed to evaluate SDRPL antimycobacterial activity. The oral bioavailability of the lipospheres was evaluated in Sprague Dawley rats. Lipospheres exhibited amorphous, smooth spherical morphology with a significant increase (p?<?0.001) in solubility of SDRPL (2:1), 350.9?±?23 versus 105.1?±?12 μg/ml and SDRPL (1:1) 306.4?±?20 versus 105.1?±?12 μg/ml in comparison to rifampicin (RMP). SDRPL exhibited enhanced activity against Mycobacterium tuberculosis, H37Rv strain, with over twofolds less minimum inhibitory concentration (MIC) than the free drug. Lipospheres exhibited higher peak plasma concentration (109.92?±?25 versus 54.31?±?18 μg/ml), faster T max (two versus four hours), and enhanced area under the curve (AUC0–∞) (406.92?±?18 versus 147.72?±?15 μg h/L) in comparison to pure RMP. Thus, SDRPL represents a promising carrier system exhibiting enhanced antimycobacterial activity and oral bioavailability of rifampicin.  相似文献   

2.
Raloxifene (RLX) has been strongly recommended for postmenopausal women at high risk of invasive breast cancer and for prevention of osteoporosis. However, low aqueous solubility and reduced bioavailability hinder its clinical application. The objective of this study was to explore the potential of RLX loaded mixed micelles (RLX-MM) using Pluronic F68 and Gelucire 44/14 for enhanced bioavailability and improved anticancer activity on human breast cancer cell line (MCF-7). RLX-MM were prepared by solvent evaporation method and optimized using 32 factorial design. The average size, entrapment efficiency and zeta potential of the optimized formulation were found to be 190?±?3.3 nm, 79?±?1.3%, 13?±?0.8 mV, respectively. In vitro study demonstrated 74.68% drug release from RLX-MM in comparison to 42.49% drug release from RLX dispersion. According to the in vitro cytotoxicity assay, GI50 values on MCF-7 breast cancer cell line for RLX-MM and free RLX were found to be 22.5 and 94.71 μg/mL, respectively. Significant improvement (P?<?0.05) in the anticancer activity on MCF-7 cell line was observed in RLX-MM over RLX pure drug. Additionally, oral bioavailability of RLX-MM was improved by 1.5-fold over free RLX when administered in female Wistar rats. Incorporation of RLX in the hydrophobic core and improved solubility of the drug due to hydrophilic shell attributed to the enhanced cytotoxicity and bioavailability of RLX-MM. This research establishes the potential of RLX loaded mixed micelles of Pluronic F68 and Gelucire 44/14 for improved bioavailability and anticancer activity on MCF-7 cell line.  相似文献   

3.
The current study aimed to develop a prolonged-release pramipexole (PPX) transdermal patch for the treatment of Parkinson’s disease. Permeation parameters of PPX were investigated using human cadaver skin. Pramipexole patches were prepared using DURO-TAK® pressure-sensitive-adhesive (PSA) and evaluated for drug stability, drug loading, in vitro drug release, and in vitro permeation through mouse skin. The results indicated that blends of DURO-TAK® 87-2852 and DURO-TAK® 87-2510 were suitable for creating a prolonged-release PPX patch due to their advantages in drug release, drug loading, and stability. The final formulation consisted of 87-2852/87-2510 (70:30), 10% PG, and 15% PPX and showed a cumulative permeation amount of 1497.19?±?102.90 μg/cm2 with a continuous flux over 6.0 μg/(cm2·h) across human cadaver skin for 7 days. In vivo studies in rats indicated that PPX patch produced a significantly longer (p?<?0.001) half-life (t 1/2, 75.16?±?17.37 h) and mean residence time (MRT, 135.89?±?24.12 h) relative to oral tablets (Sifrol®) and had a relative bioavailability of 51.64?±?21.32%. Therefore, this study demonstrated the feasibility of developing a prolonged-release PPX patch, which proposed the potential to serve as an alternate to conventional oral tablets and may therefore improve patient compliance.  相似文献   

4.
Lutein is widely used as diet supplement for prevention of age-related macular degeneration. However, the application and efficacy of lutein in food and nutritional products has been hampered due to its poor solubility and low oral bioavailability. This study aimed to develop and evaluate the formulation of oral fast-dissolving film (OFDF) containing lutein nanocrystals for enhanced bioavailability and compliance. Lutein nanocrystals were prepared by anti-solvent precipitation method and then encapsulated into the films by solvent casting method. The formulation of OFDF was optimized by Box-Behnken Design (BBD) as follows: HPMC 2.05% (w/v), PEG 400 1.03% (w/v), Cremophor EL 0.43% (w/v). The obtained films exhibited uniform thickness of 35.64 ± 1.64 μm and drug content of 0.230 ± 0.003 mg/cm2 and disintegrated rapidly in 29 ± 8 s. The nanocrystal-loaded films with reconstituted particle size of 377.9 nm showed better folding endurance and faster release rate in vitro than the conventional OFDFs with raw lutein. The microscope images, thermograms, and diffractograms indicated that lutein nanocrystals were highly dispersed into the films. After administrated to SD rats, t max was decreased from 3 h for oral solution formulation to less than 0.8 h for OFDF formulations, and C max increased from 150 ng/mL for solution to 350 ng/mL for conventional OFDF or 830 ng/mL for nanocrystal OFDF. The AUC 0-24h of conventional or nanocrystal OFDF was 1.37 or 2.08-fold higher than that of the oral solution, respectively. These results suggested that drug nanocrystal-loaded OFDF can be applied as a promising approach for enhanced bioavailability of poor soluble drugs like lutein.  相似文献   

5.
An effective protocol was developed for in vitro regeneration of the Melothria maderaspatana via indirect organogenesis in liquid and solid culture systems. Organogenesis was achieved from liquid culture calluses derived from leaf and petiole explants of mature plants. Organogenic calluses (98.2?±?0.36 and 94.8?±?0.71%) were induced from both leaf and petiole explants on Murashige and Skoog (MS) liquid medium containing 6.0 µM 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 µM thidiazuron (TDZ); and 6.0 µM 2,4-D and 1.0 µM benzyladenine (BA) combinations, respectively. Adventitious shoot regeneration (68.2?±?0.06 shoots per explant) was achieved on MS medium supplemented with 2.0 µM BA, 4.0 µM TDZ, 10% v/v coconut water and 0.06 mM glutamine from leaf-derived calluses. Petiole-derived calluses produced adventitious shoots (45.4?±?0.09 shoots per explant) on MS medium fortified with 2.0 µM BA, 4.0 µM TDZ, 10% v/v coconut water, and 0.08 mM glutamine. Elongation of shoots occurred in MS medium with 2.0 µM gibberellic acid (GA3). Regenerated shoots (2–3 cm in length) rooted (74.2?±?0.38%) and hardened (85?±?1.24%) when they were transferred to 1/2-MS medium supplemented with 3.0 µM indole-3-butyric acid (IBA) followed by garden soil, vermiculate, and sand (2:1:1 ratio) mixture. The elongated shoots (4–5 cm in length) were exposed simultaneously for rooting as well as hardening (100%) in moistened [(1/8-MS basal salt solution with 5 µM IBA and 100 mg l?1 Bavistin® (BVN)] garden soil, vermiculate, and sand (2:1:1 ratio) mixture. Subsequently, the plants were successfully established in the field. The survival percentage differed with seasonal variations.  相似文献   

6.
The present work evaluated biomass productivity, carbon dioxide fixation rate, and biochemical composition of two microalgal species, Phaeodactylum tricornutum (Bacillariophyta) and Tetradesmus obliquus (Chlorophyta), cultivated indoors in high-technology photobioreactors (HT-PBR) and outdoors both in pilot ponds and low-technology photobioreactors in a greenhouse in southern Italy. Microalgae were grown in standard media, under nitrogen starvation, and in two liquid digestates obtained from anaerobic digestion of agro-zootechnical and vegetable biomass. P. tricornutum, cultivated in semi-continuous mode in indoor HT-PBRs with standard medium, showed a biomass productivity of 21.0?±?2.3 g m?2 d?1. Applying nitrogen starvation, the lipid productivity increased from 2.3 up to 4.5?±?0.5 g m?2 d?1, with a 24 % decrease of biomass productivity. For T. obliquus, a biomass productivity of 9.1?±?0.9 g m?2 d?1 in indoor HT-PBR was obtained using standard medium. Applying liquid digestates as fertilizers in open ponds, T. obliquus gave a biomass productivity (10.8?±?2.0 g m?2 d?1) not statistically different from complete medium such as P. tricornutum (6.5?±?2.2 g m?2 d?1). The biochemical data showed that the fatty acid composition of the microalgal biomass was affected by the different cultivation conditions for both microalgae. In conclusion, it was found that the microalgal productivity in standard medium was about doubled in HT-PBR compared to open ponds for P. tricornutum and was about 20 % higher for T. obliquus.  相似文献   

7.
The objective of this study was to investigate the potential of liposomes as an ophthalmic delivery system for brinzolamide (Brz) to enhance the local glaucomatous therapeutic effect. The liposomes of Brz (Brz-LPs) were produced by the thin-film dispersion method with a particle size of 84.33?±?2.02 nm and an entrapment efficiency of 98.32?±?1.61%. Differential scanning calorimetry (DSC) and X-ray powder diffraction (XRD) analysis proved that Brz was successfully entrapped into Brz-LPs. Brz-LPs displayed a biphasic release pattern in vitro with burst release initially and sustained release afterwards. The corneal permeability was measured using modified Franz-type diffusion cells, and Brz-LPs showed 6.2-fold increase in the apparent permeability coefficient when compared with the commercial available formulation (B rz-Sus). Moreover, Brz-LPs (1 mg/mL Brz) showed a more sustained and effective intraocular pressure reduction (5–10 mmHg) than Brz-Sus (10 mg/mL Brz) in white New Zealand rabbits. Therefore, Brz-LPs were a hopeful formulation of Brz for glaucoma treatment and worthy of further investigation.  相似文献   

8.
The objective of this study was to develop an ocular drug delivery system built on the cationic liposomes, a novel bioadhesive colloidal system, which could enhance the precorneal residence time, ocular permeation, and bioavailability of ibuprofen. The optimal formulation of cationic liposomes prepared by ethanol injection method was ultimately confirmed by an orthogonal L9 (33) test design. In addition, γ-scintigraphic technology and the microdialysis technique were utilized in the assessment of in vivo precorneal retention capability and ocular bioavailability individually. In the end, we acquired the optimal formulation of ibuprofen cationic liposomes (Ibu-CL) by orthogonal test design, and the particle size and entrapment efficiency (EE%) were 121.0 ± 3.5 nm and 72.9 ± 3.4%, respectively. In comparison to ibuprofen eye drops (Ibu-ED), Ibu-CL could significantly prolong the T max to 100 min and the AUC to 1.53-folds, which indicated that the Ibu-CL could improve the precorneal retention time and bioavailability of ibuprofen. Consequently, these outcomes designated that the ibuprofen cationic liposomes we researched probably are a promising application in ocular drug delivery system.  相似文献   

9.
This study examined the co-immobilization of the cyanobacterium Synechococcus elongatus with the plant growth-promoting bacterium Azospirillum brasilense in alginate beads and its potential application for the removal of phosphorus from aquaculture wastewater. Co-immobilization of both microorganisms significantly increased the cell density of S. elongatus (2852.5?×?104 cells mL?1) compared with that of immobilization of cyanobacteria alone (1325.2?×?104 cells mL?1). Chlorophyll a content was similar in co-immobilized (11.1?±?3.5 pg cell?1) and immobilized S. elongatus (14.5?±?4.9 pg cell?1). Azospirillum brasilense showed continuous growth until day 2, after which its cell concentration declined until the end of the assay. Co-immobilized S. elongatus removed more phosphorus (44.8 %) than immobilized cyanobacteria cells alone (32.0 %). In conclusion, phosphate removal was greater with free cells of S. elongatus but overlapped with the values that were obtained with the treatment of co-immobilization of cells. Our results demonstrate that A. brasilense enhances the growth of S. elongatus and improves its removal of phosphorus when they are co-immobilized in alginate beads compared with only immobilization of cyanobacteria cells alone.  相似文献   

10.
Poor oral bioavailability is the single most important challenge in drug delivery. Prominent among the factors responsible for this is metabolic activity of the intestinal and hepatic cytochrome P450 (CYP450) enzymes. In preliminary studies, it was demonstrated that 8-arm-PEG was able to inhibit the felodipine metabolism. Therefore, this report investigated the oral bioavailability-enhancing property of 8-arm-PEG employing detailed in vitro, in vivo, and in silico evaluations. The in vitro metabolism of felodipine by cytochrome P450 3A4-expressed human liver microsomes (HLM) was optimized yielding a typical Michaelis–Menten plot through the application of Enzyme Kinetic Module software from where the enzyme kinetic parameters were determined. In vitro investigation of 8-arm-poly(ethylene glycol) against CYP3A4-catalyzed felodipine metabolism employing human liver microsomes compared closely with naringenin, a typical grapefruit flavonoid, yielding IC50 values of 7.22 and 121.97 μM, respectively. The investigated potential of 8-arm-poly(ethylene glycol) in oral drug delivery yielded satisfactory in vitro drug release results. The in vivo studies of the effects of 8-arm-poly(ethylene glycol) on the oral bioavailability of felodipine as performed in the Large White pig model showed a >100% increase in plasma felodipine levels compared to controls, with no apparent effect on systemic felodipine clearance. The outcome of this research presents a novel CYP3A4 inhibitor, 8-arm-poly(ethylene glycol) for oral bioavailability enhancement.  相似文献   

11.
The objectives of the current investigation are (1) to prepare and characterize (particle size, surface charge (potential zeta), surface morphology by transmission electron microscopy, drug content, and drug release) the azithromycin (AZM, 100 mg)-loaded oil-in-water (o/w) macroemulsion, (2) to assess the toxicity of macroemulsion with or without AZM using RBC lysis test in comparison with AZM in phosphate buffer solution of pH 7.4, (3) to compare the in vitro antimicrobial activity (in Escherichia coli using zone inhibition assay) of AZM-loaded macroemulsion with its aqueous solution, and (4) to assess the in vitro anti-inflammatory effect (using egg albumin denaturation bioassay) of the AZM-loaded macroemulsion in comparison with diclofenac sodium in phosphate buffer solution of pH 7.4. The AZM-loaded macroemulsion possessed the dispersed oil droplets with a mean diameter value of 52.40?±?1.55 μm. A reversal in the zeta potential value from negative (?2.16?±?0.75 mV) to positive (+6.52?±?0.96 mV) was noticed when AZM was added into the macroemulsion. At a 1:5 dilution ratio, 2.06?±?0.03 mg of drug was released from macroemulsion followed by 1.01?±?0.01 and 0.25?±?0.08 mg, respectively, for 1:10 and 1:40 dilution ratios. Antimicrobial activity maintenance and significant reduction of RBC lysis property were noticed for AZM after loaded in the macroemulsion. However, an increment in the absorbance values for emulsion-treated samples in comparison to the control samples was noticed in the anti-inflammatory test. This speculates the potential of the AZM-loaded emulsion to manage inflammatory conditions produced at Acne vulgaris.  相似文献   

12.
The aim of this work was to establish a method for preparing stable and controllable solid self-microemulsifying drug delivery system (S-SMEDDS) by spherical crystallization technique, which was explored for promoting the dissolution, oral bioavailability, and process efficiency. Solubility test, preparation of liquid self-microemulsifying drug delivery system (L-SMEDDS), and the obtained ternary phase diagrams test have been performed to screen and optimize the composition of LSMEDDS. The optimized formulation was used to prepare puerarin solid self-microemulsifying drug delivery system (Pue-SSMEDDS) by spherical crystallization technique. Droplet size and morphological analysis of the optimal Pue-SSMEDDS were determined to evaluate the final formulation. And the Pue-SSMEDDS was also assessed by flowability study, angle of repose, Carr’s index, and flow velocity. Furthermore, the vitro dissolution and pharmacokinetic profile in vivo were analyzed. The study in vitro showed the Pue-SSMEDDS could disperse in the dispersion medium within 60 s and was spherical with the particle size of 19.66 nm and zeta potential of ?28.3 mV. It could keep stable at low temperature and seal condition for 3 months. In vivo pharmacokinetic experiments of rats, the mean plasma concentration of self-microemulsion group was much higher than that of conventional tablets and could play a long-lasting efficacy, while there was no significant difference between the LSMEDDS and S-SMEDDS. The results suggested the potential of S-SMEDDS could improve the oral bioavailability of poorly water-soluble drug, such as puerarin.  相似文献   

13.
A Gram-stain negative, aerobic, motile by flagella, rod-shaped strain (THG-T16T) was isolated from rhizosphere of Hibiscus syriacus. Growth occurred at 10–40 °C (optimum 28–30 °C), at pH 6.0–8.0 (optimum 7.0) and at 0–1.0% NaCl (optimum 0%). Based on 16S rRNA gene sequence analysis, the near phylogenetic neighbours of strain THG-T16T were identified as Nibribacter koreensis KACC 16450T (98.6%), Rufibacter roseus KCTC 42217T (94.7%), Rufibacter immobilis CCTCC AB 2013351T (94.5%) and Rufibacter tibetensis CCTCC AB 208084T (94.4%). The DNA G+C content of strain THG-T16T was determined to be 46.7 mol%. DNA–DNA hybridization values between strain THG-T16T and N. koreensis KACC 16450T, R. roseus KCTC 42217T, R. immobilis CCTCC AB 2013351T, R.tibetensis CCTCC AB 208084T were 33.5?±?0.5% (31.7?±?0.7% reciprocal analysis), 28.1?±?0.2% (25.2?±?0.2%), 17.1?±?0.9% (10.2?±?0.6%) and 8.1?±?0.3% (5.2?±?0.1%). The polar lipids were identified as phosphatidylethanolamine, two unidentified aminophospholipids, an unidentified aminolipid and three unidentified lipids. The quinone was identified as MK-7 and the polyamine as sym-homospermidine. The major fatty acids were identified as C16:1 ω5c, C17:1 ω6c, iso-C15:0, summed feature 3 (C16:1 ω7c and/or C16:1 ω6c) and summed feature 4 (iso-C17:1 I and/or anteiso-C17:1 B). On the basis of the phylogenetic analysis, chemotaxonomic data, physiological characteristics, and DNA–DNA hybridization data, strain THG-T16T represents a novel species of the genus Nibribacter, for which the name Nibribacter flagellatus sp. nov. is proposed. The type strain is THG-T16T(=?KACC 19188T?=?CCTCC AB 2016246T).  相似文献   

14.
The present study reports the in vitro biological nature of the pigment produced by Staphylococcus gallinarum KX912244, isolated as the gut microflora bacterium of the insect Bombyx mori. The purified pigment was characterized as Staphyloxanthin based on bio-physical characterization techniques like Fourier transform infrared spectroscopy, high performance liquid chromatography, Proton nuclear magnetic resonance spectroscopy (1H NMR), Liquid chromatography-Mass spectroscopy and Gas chromatography-Mass spectroscopy. The Staphyloxanthin pigment presented considerable biological properties including in vitro antimicrobial activity against pathogens Staphylococcus aureus, Escherichia coli and Candida albicans; in vitro antioxidant activity by % DPPH free radical scavenging activity showing IC50 value of 54.22 µg/mL; DNA damage protection activity against reactive oxygen species and anticancer activity evaluated by cytotoxicity assay against 4 different cancer cell lines like the Dalton’s lymphoma ascites with IC50 value 6.20?±?0.02 µg/mL, Ehrlich ascites carcinoma having IC50 value 6.48?±?0.15 µg/mL, Adenocarcinomic human alveolar basal epithelial cells (A549 Lung carcinoma) bearing IC50 value 7.23?±?0.11 µg/mL and Mus mucus skin melanoma (B16F10) showing IC50 value 6.58?±?0.38 µg/mL and less cytotoxicity towards non-cancerous human fibroblast cell lines (NIH3T3) with IC50 value of 52.24 µg/mL. The present study results suggest that Staphyloxanthin acts as a potential therapeutic agent especially due to its anticancer property.  相似文献   

15.
The expression of nine functional candidates for QT abdominal fat weight and relative abdominal fat content was investigated by real-time polymerase chain reaction (PCR) in the liver, adipose tissue, colon, muscle, pituitary gland and brain of broilers. The high mobility group AT-hook 1 (HMG1A) gene was up-regulated in liver with a ratio of means of 2.90 (P?≤?0.01) in the «fatty» group (relative abdominal fat content 3.5?±?0.18%, abdominal fat weight 35.4?±?6.09 g) relative to the «lean» group (relative abdominal fat content 1.9?±?0.56%, abdominal fat weight 19.2?±?5.06 g). Expression of this gene was highly correlated with the relative abdominal fat content (0.70, P?≤?0.01) and abdominal fat weight (0.70, P?≤?0.01). The peroxisome proliferator-activated receptor gamma (PPARG) gene was also up-regulated in the liver with a ratio of means of 3.34 (P?≤?0.01) in the «fatty» group relative to the «lean» group. Correlation of its expression was significant with both the relative abdominal fat content (0.55, P?≤?0.05) and the abdominal fat weight (0.57, P?≤?0.01). These data suggest that the HMG1A and PPARG genes were candidate genes for abdominal fat deposition in chickens. Searching of rSNPs in regulatory regions of the HMG1A and PPARG genes could provide a tool for gene-assisted selection.  相似文献   

16.
The aim of this work was to evaluate the effects of co-inoculation with phosphate-solubilizing and nitrogen-fixing rhizobacteria on growth promotion, yield, and nutrient uptake by wheat. Out of twenty-five bacteria isolated from the rhizosphere soils of cereal, vegetable, and agro-forestry plants in eastern Uttar Pradesh, three superior most plant growth-promoting (PGP) isolates were characterized as Serratia marcescens, Microbacterium arborescens, and Enterobacter sp. based on their biochemical and 16S rDNA gene sequencing data and selected them for evaluating their PGP effects on growth and yield of wheat. Among them, Enterobacter sp. and M. arborescens fixed significantly higher amounts (9.32?±?0.57 and 8.89?±?0.58 mg Ng?1 carbon oxidized, respectively) of atmospheric nitrogen and produced higher amounts (27.06?±?1.70 and 26.82?±?1.63 TP 100 µg mL?1, respectively) of IAA in vitro compared to S. marcescens (8.32?±?0.39 mg Ng?1 carbon oxidized and 21.29?±?0.99 TP 100 µg mL?1). Although both M. arborescens and S. marcescens solubilized remarkable amounts of phosphate from tricalcium phosphate likely through production of organic acids, however, Enterobacter sp. was inactive. The effects of these three rhizobacteria were evaluated on wheat in alluvial soils of the Indo-Gangetic Plain by inoculation of plants with bacterial isolates either alone or in combinations in both pot and field conditions for two successive years. Rhizobacterial inoculation either alone or in consortium of varying combinations significantly (P?≤?0.05) increased growth and yield of wheat compared to mock inoculated controls. A consortium of two or three rhizobacterial isolates also significantly increased plant height, straw yield, grain yield, and test weight of wheat in both pot and field trials compared to single application of any of these isolates. Among the rhizobacterial treatment, co-inoculation of three rhizobacteria (Enterobacter, M. arborescens and S. marcescens) performed best in promotion of growth, yield, and nutrient (N, P, Cu, Zn, Mn, and Fe) uptake by wheat. Taken together, our results suggest that co-inoculation of Enterobacter with S. marcescens and M. arborescens could be used for preparation of an effective formulation of PGP consortium for eco-friendly and sustainable production of wheat.  相似文献   

17.
The objective of this study was to evaluate the efficacy of three eco-friendly control agents, either singly or in a pairwise combination, for the control of the tomato leafminer, Tuta absoluta (Meyrick) (Lep: Gelechiidae). They include the naturally derived pesticide spinosad, a commercially available formulation of Bacillus thuringiensis var. Kurstaki (Bt), and a native population of Trichogramma brassicae Bezdenko (Hym: Trichogrammatidae). Tomato plants containing the T. absoluta were treated with one of the seven following treatments in a greenhouse: (1) a single release of T. brassicae against the eggs; (2) two applications of Bt (2 kg ha?1); (3) and (4) one application of spinosad at two rates (60 and 120 g a.i. ha?1); (5) T. brassicae release?+?Bt spray; (6) T. brassicae release?+?spinosad spray; and (7) spinosad spray?+?Bt spray. The highest mortality rate was recorded for the spinosad?+?Bt (88.33?±?1.43%) and T. brassicae?+?spinosad (78.33?±?3.74%) combinations, respectively; while the lowest mortality rate was obtained through the single application of T. brassicae (31.67?±?4.84%). Based on our results, the Bt and spinosad seem to be suitable candidates for combination with other biological and cultural techniques towards an integrated management of the tomato leafminer.  相似文献   

18.
Schizotetranychus oryzae Rossi de Simons (Acari: Tetranychidae) is considered one of the most important phytophagous mite in rice cultivation in the Americas South, Central, and North. This study aimed to examine some biological aspects of S. oryzae developing on leaves of three different cultivars of rice [Oryza sativa (L.)—Poaceae] produced in the state of Rio Grande do Sul, Brasil. The plants were kept in a room at 25?±?1°C, with natural light (photophase of approximately 14 h) and 70?±?5% relative humidity. During the immature stages, observations were carried out daily at 7 am, 1 pm, and 7 pm. The results showed that the mean duration of the egg–adult period in days were similar between cultivars evaluated (Irga 424, 11.27?±?0.13; Taim, 11.21?±?0.14 and Sinuelo, 11.13?±?0.15). Egg–adult viability on Irga 424, Sinuelo, and Taim was 61.9, 85.71, and 90.48%, respectively, being lowest on Irga 424 (χ2?=?28.62, p?<?0.0001). The duration of the immature stages was not affected by cultivar, but on Irga 424, egg–adult viability and female longevity were lower. The results of this study can help select O. sativa cultivar resistant to S. oryzae. However, historically, the IRGA 424 has lower populations of S. oryzae in field conditions.  相似文献   

19.
Although Streptococcus parauberis is the major bacterial pathogen affecting olive flounder, the translocation and dissemination of this pathogen in infected fish are not well understood. Therefore, we conducted real-time PCR and histopathologic examination to monitor the intensity of infection in multiple organs of the olive flounder after challenge with S. parauberis through subcutaneous injection. The bacterial burden in the fish kidney, when sampled at 0, 3, and 7 dpc, was 0, 6.2?±?4.5?×?105, and 6.7?±?5.5?×?106 CFU/100 mg of tissue, respectively, indicating that the infection progressed rapidly over time. Of the ten different tissues sampled, the heart and the brain were the major target organs of S. parauberis based on highest copy number as detected by our modified real-time PCR method. Histopathologic examination also showed that S. parauberis caused severe inflammation accompanied by leucocyte infiltration, connective tissue expansion, and a loss of cardiomyocytes in the brain and heart of fish sampled at dpc 7. However, the number of S. parauberis-positive fish at 3 dpc was much higher in the spleen (6/8 fish) than in the remaining organs, suggesting that the spleen is targeted in the early stages of infection relative to the heart (2/8 fish) or brain (3/8 fish). This study provides essential information for studies to find treatments for the effective elimination of S. parauberis in target organs (i.e., the brain and heart) of olive flounder.  相似文献   

20.
Direct somatic embryogenesis is favoured over indirect methods for the in vitro propagation of Coffea canephora, as the frequency of somaclonal variation is usually reduced. Ethylene action inhibitors improve the tissue culture response and thus silver nitrate (AgNO3) is used for direct somatic embryogenesis in coffee. It was observed that silver thiosulphate (STS) that is a more potent ethylene action inhibitor, induced a much robust response in C. canephora cotyledonary leaf explants with 7.49?±?0.57 and 7.08?±?0.12 embryos/explant at 60 and 80 µM AgNO3, respectively compared to 3.3?±?0.18 embryos/explant at 40 µM AgNO3. Transient transformation indicated that STS improved the transformation potential of embryos by enhancing Agrobacterium tumefaciens adherence to surfaces. In vitro adherence assays demonstrated that the cell wall material from STS-derived embryos provide a better substratum for adherence of Agrobacterium. Furthermore, blocking this substratum with anti-mannan hybridoma supernatant negatively effects the adherence. The presence of galactose and mannose residues in the decomposed cellulose fraction of STS treated somatic embryos are indicative of de-branching and re-modelling of galactomannan in response to ethylene inhibition. Genes of mannan biosynthesis, degradation and de-branching enzyme were affected to different extents in embryos derived in AgNO3 and STS containing somatic embryogenesis medium. The results indicate that ethylene-mediated cell wall galactomannan remodelling is vital for improving the transgenic potential in coffee.  相似文献   

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