Subject(s)
Legislation, Medical/history , Clinical Competence/legislation & jurisprudence , Evidence-Based Medicine/history , History, 17th Century , History, 18th Century , History, 19th Century , History, 20th Century , Physicians/history , Quality of Health Care/history , Quality of Health Care/legislation & jurisprudence , Societies, Medical/history , SwedenABSTRACT
Phytosterols (PS) are naturally occurring compounds present in food products of plant origin. Due to reported positive health effects, some food products are also enriched with PS. In the same way as cholesterol is oxidised, PS also oxidise to a variety of oxidation products (POPs). The biological effects and safety aspects of POPs are still unclear. This study investigated whether POPs are genotoxic in vivo, using a flow cytometer-based micronucleus assay in mice. The highest dose of oxidation products administered was 67mg/kg b.w. for epoxides and 9.4mg/kg b.w. for triols. Synthesised and separated triols and epoxides from a mixture of sitosterol and campesterol were investigated. The frequency of micronucleated polychromatic erythrocytes (fMNPCE) in POP-exposed mice did not significantly differ from the control values in either of two experiments performed. The flow cytometer-based method also allows for restriction of the analysis to micronuclei with a high DNA content, indicating an aneugenic potency. Even with this approach, there was no significant increase in the frequency of micronucleated erythrocytes among POP-treated mice compared with control mice. Furthermore, no significant deviation in cell proliferation rate (%PCE) was observed.
Subject(s)
Epoxy Compounds/toxicity , Erythrocytes/drug effects , Micronuclei, Chromosome-Defective , Mutagens/toxicity , Phytosterols/toxicity , Animals , Cell Proliferation/drug effects , Cholesterol/analogs & derivatives , Cholesterol/toxicity , Dose-Response Relationship, Drug , Epoxy Compounds/metabolism , Flow Cytometry , Male , Mice , Mice, Inbred CBA , Micronucleus Tests/methods , Mutagens/metabolism , Oxidation-Reduction , Phytosterols/metabolism , Sitosterols/toxicityABSTRACT
The number of characterized phytosterol oxidation products (POPs) from both ring- and side-chain structures has increased during recent decades, resulting in difficulties in the separation of POPs on different gas chromatography (GC) capillary columns. The main objective of this study was to separate a mixture of 29 purified and characterized oxidation products from sito-, campe- and stigmasterol using GC capillary columns with different polarity. For the first time in the area of POPs analysis, the separation efficiency of the combination of two capillary GC columns with different polarities was investigated. A non-polar 5% phenyl coated (DB5-MS) and a mid-polar 35% phenyl coated (DB35-MS) column was combined with a pressfit connector. The main improvement was enhanced base line separation for many of the analyzed POPs, compared with the separations achieved using the individual columns. However, three pairs of POPs co-eluted: 24-hydroxysitosterol/campesterol-5beta,6beta-epoxide, stigmasterol-5beta,6beta-epoxide/campesterol-5alpha,6alpha-epoxide and stigmasterol-5alpha,6alpha-epoxide/campestanetriol.
Subject(s)
Chromatography, Gas/instrumentation , Phytosterols/chemistry , Oxidation-ReductionABSTRACT
In the present study, quantitative analysis of the cochlear neurons in the osseous spiral lamina, the modiolus and the internal auditory canal of the same cochlea was performed. Forty-five temporal bones were obtained from 25 patients and prepared by means of microdissection. Ten patients had age-related normal hearing (ARNH) assuming that the 5 children without audiogram had normal hearing. Fifteen patients had sensorineural hearing loss due to various causes. The present study has shown that in young individuals the numbers of cochlear neurons are almost identical at all 3 sites. In patients over 60 years with ARNH, the loss of peripheral nerve processes is always severer than the loss of central nerve processes. This finding suggests that the central processes degenerate at a much slower rate or not at all. Furthermore, 4 different peripheral degeneration patterns were described. The factors responsible for the different degeneration behaviors are still not understood and need further investigation.
