| 1. |
- Eick, Sigrun, et al.
(författare)
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Honey - a potential agent against Porphyromonas gingivalis: an in vitro study
- 2014
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Ingår i: BMC Oral Health. - : Springer Science and Business Media LLC. - 1472-6831. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Background Honey has been discussed as a therapeutic option in wound healing since ancient time. It might be also an alternative to the commonly used antimicrobials in periodontitis treatment. The in-vitro study was aimed to determine the antimicrobial efficacy against Porphyromonas gingivalis as a major periodontopathogen. Methods One Manuka and one domestic beekeeper honey have been selected for the study. As a screening, MICs of the honeys against 20 P. gingivalis strains were determined. Contents of methylglyoxal and hydrogen peroxide as the potential antimicrobial compounds were determined. These components (up to 100 mg/l), propolis (up to 200 mg/l) as well as the two honeys (up to 10% w/v) were tested against four P. gingivalis strains in planktonic growth and in a single-species biofilm. Results 2% of Manuka honey inhibited the growth of 50% of the planktonic P. gingivalis, the respective MIC50 of the German beekeeper honey was 5%. Manuka honey contained 1.87 mg/kg hydrogen peroxide and the domestic honey 3.74 mg/kg. The amount of methylglyoxal was found to be 2 mg/kg in the domestic honey and 982 mg/kg in the Manuka honey. MICs for hydrogen peroxide were 10 mg/l - 100 mg/l, for methylglyoxal 5 – 20 mg/l, and for propolis 20 mg/l – 200 mg/l. 10% of both types of honey inhibited the formation of P. gingivalis biofilms and reduced the numbers of viable bacteria within 42 h-old biofilms. Neither a total prevention of biofilm formation nor a complete eradication of a 42 h-old biofilm by any of the tested compounds and the honeys were found. Conclusions Honey acts antibacterial against P. gingivalis. The observed pronounced effects of Manuka honey against planktonic bacteria but not within biofilm can be attributed to methylglyoxal as the characteristic antimicrobial component.
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| 2. |
- Hall, James P., et al.
(författare)
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Guanine Can Direct Binding Specificity of Ru-dipyridophenazine (dppz) Complexes to DNA through Steric Effects
- 2017
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Ingår i: Chemistry - A European Journal. - : Wiley-VCH Verlagsgesellschaft. - 0947-6539 .- 1521-3765. ; 23:21, s. 4981-4985
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Tidskriftsartikel (refereegranskat)abstract
- X-ray crystal structures of three -[Ru(L)(2)dppz](2+) complexes (dppz=dipyridophenazine; L=1,10-phenanthroline (phen), 2,2-bipyridine (bpy)) bound to d((5BrC)GGC/GCCG) showed the compounds intercalated at a 5-CG-3 step. The compounds bind through canted intercalation, with the binding angle determined by the guanine NH2 group, in contrast to symmetrical intercalation previously observed at 5-TA-3 sites. This result suggests that canted intercalation is preferred at 5-CG-3 sites even though the site itself is symmetrical, and we hypothesise that symmetrical intercalation in a 5-CG-3 step could give rise to a longer luminescence lifetime than canted intercalation.
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| 3. |
- Reinke, Beth A, et al.
(författare)
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Diverse aging rates in ectothermic tetrapods provide insights for the evolution of aging and longevity
- 2022
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Ingår i: Science. - : American Association for the Advancement of Science. - 0036-8075 .- 1095-9203. ; 376:6600, s. 1459-1466
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Tidskriftsartikel (refereegranskat)abstract
- Comparative studies of mortality in the wild are necessary to understand the evolution of aging; yet, ectothermic tetrapods are underrepresented in this comparative landscape, despite their suitability for testing evolutionary hypotheses. We present a study of aging rates and longevity across wild tetrapod ectotherms, using data from 107 populations (77 species) of nonavian reptiles and amphibians. We test hypotheses of how thermoregulatory mode, environmental temperature, protective phenotypes, and pace of life history contribute to demographic aging. Controlling for phylogeny and body size, ectotherms display a higher diversity of aging rates compared with endotherms and include phylogenetically widespread evidence of negligible aging. Protective phenotypes and life-history strategies further explain macroevolutionary patterns of aging. Analyzing ectothermic tetrapods in a comparative context enhances our understanding of the evolution of aging.
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