1,721,129 research outputs found
A rationale for glutatione therapy. Is antioxidant therapy a promising strategy to improve human reproduction?
No full textStudio degli effetti di molecole antiossidanti in un modello di senescenza cutanea foto-accelerata
No full textLipids of Sperm Plasma Membrane: from polyunsaturated fatty acid considered as markers of Sperm Function to Possible Scavenger Therapy.» :,
No full textThis article is, in part, a review of present knowledge regarding the lipid metabolism of the sperm cell and the lipid composition of the sperm plasma membrane. It is also a summary of our research on this topic, reporting published and unpublished data. The article tries to cover both basic and clinical research. Sperm cells use lipid metabolic pathways for the production of part of their energy. The double leaflets of the membrane are not simply a passive, bilayer, lipidic film in which the receptors receive their molecular specific signals, but are a very specialized structure. Complete maturation of the lipids of the sperm cell membrane is reached after passage of the spermatozoon through the epididymis. A specific composition of phospholipids and a significant concentration of polyunsaturated fatty acids (PUFA) have been shown to be present in sperm membranes. Plasmalogen is a special kind of phospholipid found exclusively in spermatozoa and other cells with the capacity to react promptly to stimuli. In addition, we have found a high concentration of the n-3 PUFA family in the sperm membrane. Seminal plasma has a highly specialized scavenger system that defends the sperm membrane against lipoperoxidation. Various pathologies and systemic predisposition can lead to an antioxidant/pro-oxidant disequilibrium. Clinical trials with natural scavengers could be a useful research area in which to seek a treatment for these pathologies. Of the natural scavengers, glutathione has been shown to restore the physiological constitution of PUFA in the cell membrane under certain condition
Direct immersion SPME-GC-MS method for polycyclic aromatic hydrocarbons determination in edible oil
No full textPolycyclic aromatic hydrocarbons (PAHs) are a group of organic compounds produced through incomplete combustion or pyrolysis of organic matter. The occurrence of PAHs in food is due to environmental contamination, technological processing and from contaminated packaging material. Since they have been proven to present carcinogenic and genotoxic effect, the rapid and reliable determination of these compounds in food is very important. Solid-phase microextraction is an easy preparation technique, which allows to minimize solvent consumption and reduce sample manipulation. A Carbopack Z/ polydimethylsiloxane fiber, particularly suitable for extraction of planar compounds, was employed to extract PAHs. The method was first developed by direct immersion of the fiber in a diluted oil sample in hexane. Although very good results were obtained in terms of repeatability, accuracy, limit of detection, and limit of quantification, the method was never routinely applied since required frequent ion source cleaning and shortened the column life. Therefore a preliminary purification step was added to eliminate most of the triglycerides before the immersion of the fiber into the final hexane solution. A rapid extraction of PAHs from oil was performed using a low amount of acetonitrile, then the compounds were back-extracted in hexane. Despite the non-quantitative extraction of polycyclic aromatic hydrocarbons from oil using acetonitrile, the signal-to-noise ratio was significantly improved obtaining a limit of detection largely below the performance criteria required by the European Union legislation
Biomimetic nitration of the linoleic acid metabolite 13-hydroxyoctadecadienoic acid: isolation and spectral characterization of novel chain-rearranged epoxy nitro derivatives.
No full textNitration of unsatd. fatty acids is a (patho)physiol. important pathway of lipid modification induced by nitric oxide-derived species. We report herein on the unexpected chain rearrangement undergone by (13S,9Z,11E)-13-hydroxyoctadeca-9,11-dienoic acid (I), a linoleic acid metabolite, when exposed to nitrating agents of biol. relevance. At pH 7.4 and at room temp., reaction of I with peroxynitrite (ONOO-) as well as Fe2+-EDTA/H2O2/NO2- and horseradish peroxidase/H2O2/NO2- led to the formation of two nitration products, which could be isolated as the Me esters and were identified as diastereoisomeric Me (12S)-10,11-epoxy-12-hydroxy-9-(nitromethyl)heptadecanoates by extensive 1H, 13C, 15N NMR and MS anal
In vivo data non-invasive methods for vitiligo evaluation electron microscopy
No full textCore Messages: The extension and severity of vitiligo guide prognosis and help making therapeutic choices. However, in spite of attempts to standardise clinical judgment, wide variations exist both in assessment rules and interpretation of their use, making intra-and inter-observer variations unavoidable. Ultraviolet (UV)-light examination and UV photography remain useful tools for the assessment of Caucasoid patients. Non-invasive instruments that use reflectance spectroscopy provide a convenient and reproducible methodology for the study of vitiligo patients and their follow-up. Reflectance confocal microscopy provides microscopical informations in vivo about changes in achromic macules both in repig-mented areas after treatments and in clinically normal-appearing skin of vitiligo patients
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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Anti-HPV vaccination: a review of recent economic data for Italy
No full textThe total cost of HPV-related diseases accounts for euro 200-250 million of which euro 210 million is absorbed by the prevention and treatment of precancerous lesions and cervical cancer. Although both available HPV vaccines are below the threshold value for economic convenience (euro 9,569 and euro 26,361 per QALY-gained for the quadrivalent and bivalent vaccines, respectively), at this point in time long-term economic models developed for Italy seem to indicate the quadrivalent vaccine as the most cost-effective option. Recent publications by official bodies, including the World Health Organization and the Supervisory Authority for Public Contracts in Italy, recommend that the decision-making process be based on both the quality of goods and services as well as the best achievable price
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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