Abstract
Numerous plant extracts are abundant in biomolecules that can be employed in the biogenic synthesis of metallic nanoparticles owing to their potent reducing capabilities. The mechanism by ...which biomolecules act as reducers and expedite the reduction of silver ions remains poorly understood. This study presents an instantaneous and environmentally friendly synthesis of silver nanoparticles (AgNPs) using varying concentrations of commercially available green tea and concentrations of a dextrose-reducing solution. The AgNPs formed instantaneously, likely due to the competitive reaction between the polyphenols present in green tea and the dextrose. The best AgNPs produced using a diluted green tea solution at a concentration of 0.05 g of tea/ml and 100
μ
l of dextrose solution exhibited high stability over a period of 90 days, as confirmed by UV–vis spectroscopy and dynamic light scattering. The results of antioxidant properties from diluited tea showed 2,2-diphenyl-1-picrylhydrazyl (DPPH) 0.013 ± (0.1)
μ
mol Trolox Equivalent Anyioxidant Capacity (TEAC) TEAC/g, Ferric Reducing Antioxidant Power (FRAP) 10.3 ± (0.1)
μ
mol TEAC/g and Total Polyphenol Content (TPC) 0.12 ± (.001)
μ
gGAE(Galic Acid Equivalent)/g). The resulting nanoparticles are extremely small, measuring approximately 30 to 50 nm in size, and exhibit a spherical morphology as evidenced by SEM imaging. The plasmon bandwidth is better in more diluted tea and higher proportions of dextrose added than the others condition of synthesis. Probably, the results of 2nd extraction of green tea diluted can be evidence that phenolic compounds, mainly, caffeine and gallic acid, are contributing to forming and stabilizing the silver nanoparticles. This fundamental knowledge showed the method employed is ecologically sound and adheres to green principles.
Background Lower esophageal sphincter (LES) electrical stimulation therapy (EST) has been shown to improve outcome in gastroesophageal reflux disease (GERD) patients at 1 year. The aim of this ...open-label extension trial (NCT01578642) was to study the 2-year safety and efficacy of LES-EST in GERD patients. Methods GERD patients responsive partially to proton pump inhibitors (PPI) with off-PPI GERD health-related quality of life (HRQL) of ≥20, 24-hour esophageal pH ≤4.0 for >5% of the time, hiatal hernia ≤3 cm, and esophagitis LA grade C or lower participated in this trial. Bipolar stitch electrodes and a pulse generator (EndoStim BV, The Hague, The Netherlands) were implanted laparoscopically. LES-EST at 20 Hz, 215 μs, 3-8 mAmp was delivered over 30-minute sessions, 6-12 sessions per day, starting on day 1 after implantation. Patients were evaluated using GERD-HRQL, symptom diaries, Short Form-12, and esophageal pH testing at regular intervals. Stimulation sessions were optimized based on residual symptoms and esophageal pH at follow-up. Results Twenty-five patients (mean age SD = 52 12 years; 14 men) were implanted successfully; 23 patients participated in the 2-year extension trial, and 21 completed their 2-year evaluation. At 2 years, there was improvement in their median GERD-HRQL on LES-EST compared with both their on-PPI (9 vs 0; P = .001) and off-PPI (23.5 vs 0; P < .001) baseline scores. Median 24-hour distal esophageal acid exposure improved from 10% at baseline to 4% (per-protocol analysis; P < .001) at 2 years with 71% demonstrating either normalization or a ≥50% decrease in their distal esophageal acid exposure. All except 5 patients (16/21) reported complete cessation of PPI use; only 2 patients were using a PPI regularly (≥50% of days). There was significant improvement in sleep quality and daily symptoms of heartburn and regurgitation on LES-EST. At baseline, 92% of the subjects (22/24) reported that they were “unsatisfied” with their condition off-PPI and 71% (17/24) on-PPI compared with 0% (0/21) “unsatisfied” at the 24-month visits on LES-EST. There were no device- or therapy-related serious adverse events and no untoward sensation or dysphagia reported with LES-EST. Conclusion LES-EST is safe and effective for treating patients with GERD over a period of 2 years. LES-EST resulted in a significant and sustained improvement in GERD symptoms, and esophageal acid exposure and eliminated PPI use in majority of patients (16 of 21). Further, LES-EST was not associated with any gastrointestinal side effects or adverse events.
Melipona marginata is an endangered species of stingless bee from Brazil that produces honey with particular physicochemical features and a remarkable exotic flavor. To the best of our knowledge, ...this is the first report devoted to exploring the medicinal potential of this honey. Thus, the aim of this paper was to investigate the potential anti-inflammatory activity of honey extract from M. marginata on skin inflammation. The honey sample was classified as a monofloral honey of Mimosa scabrella. The presence of 11 phenolic compounds as kaempferol and caffeic acid was detected using the high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-UV-ESI-MS) method. The anti-inflammatory activity was measured using a 12-O-tetradecanoylphorbol-13-acetate-induced ear edema model of inflammation in mice. The topical application of the M. marginata honey extract (1.0 mg/ear) was able to reduce ear edema with an inhibitory effect of 54±5%. This extract decreased the myeloperoxidase activity in 75±3%, which suggests a lower leucocyte infiltration that was confirmed by histological analysis. This extract also provided a reduction of 55±14% in the production of reactive oxygen species. This anti-inflammatory activity could be due to a synergic effect of the phenolic compounds identified in the honey sample. Taken together, these results open up new possibilities for the use of M. marginata honey extract in skin disorders.
Abstract Mucosal immune responses induced by HIV-1 vaccines are likely critical for prevention. We report a Phase 1 safety and immunogenicity trial in eight participants using the vaccinia -based ...TBC-3B vaccine given subcutaneously to determine the relationship between HIV-1 specific systemic and gastrointestinal mucosal responses. Across all subjects, detectable levels of blood vaccinia - and HIV-1-specific antibodies were elicited but none were seen mucosally. While the vaccinia component was immunogenic for CD8+ T lymphocyte (CTL) responses in both blood and mucosa, it was greater in blood. The HIV-1 component of the vaccine was poorly immunogenic in both blood and mucosa. Although only eight volunteers were studied intensively, the discordance between mucosal and blood responses may highlight mechanisms contributing to recent vaccine failures.
The host immune factors that determine susceptibility to HIV-1 infection are poorly understood. We compared multiple immunologic parameters in three groups of HIV-1-seronegative men: 14 highly ...exposed (HR10), 7 previously reported possibly to have sustained transient infection (PTI), and a control group of 14 low risk blood bank donors (BB). Virus-specific cellular immune assays were performed for CD4(+) T helper cell responses, CD8(+) cytotoxic T lymphocyte activity, CD8(+) cell chemokine release, and CD8(+) cell-derived antiviral soluble factor activity. General immune parameters evaluated included CCR5 genotype and phenotype, interferon alpha production by PBMCs, leukocyte subset analysis, and detailed T lymphocyte phenotyping. Comparisons revealed no detectable group-specific differences in measures of virus-specific immunity. However, the HR10 group differed from the BB group in several general immune parameters, having higher absolute monocyte counts, higher absolute CD8(+) T cell counts and percentages, lower naive and higher terminal effector CD8(+) cells, and lower levels of CD28(+)CD8(+) cells. These changes were not associated with seropositivity for other chronic viral infections. The PTI men appeared to have normal levels of monocytes and slightly elevated levels of CD8(+) T cells (also with increased effector and decreased naive cells). Although we cannot entirely exclude the contribution of other chronic viral infections, these findings suggest that long-lived systemic cellular antiviral immunity as detected by our assays is not a common mechanism for resistance to infection, and that resistance may be multifactorial. General immune parameters reflected by CD8(+) T cell levels and activation, and monocyte concentrations may affect the risk of infection with HIV-1, and/or serve as markers of exposure.
Mucosal immune responses induced by HIV-1 vaccines are likely critical for prevention. We report a Phase 1 safety and immunogenicity trial in eight participants using thevaccinia-based TBC-3B vaccine ...given subcutaneously to determine the relationship between HIV-1 specific systemic and gastrointestinal mucosal responses. Across all subjects, detectable levels of bloodvaccinia- and HIV-1-specific antibodies were elicited but none were seen mucosally. While thevacciniacomponent was immunogenic for CD8+T lymphocyte (CTL) responses in both blood and mucosa, it was greater in blood. The HIV-1 component of the vaccine was poorly immunogenic in both blood and mucosa. Although only eight volunteers were studied intensively, the discordance between mucosal and blood responses may highlight mechanisms contributing to recent vaccine failures.
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