48 research outputs found

    The peppermint breath test benchmark for PTR-MS and SIFT-MS

    Get PDF
    18openInternationalInternational coauthor/editorA major challenge for breath research is the lack of standardization in sampling and analysis. To address this, a test that utilizes a standardized intervention and a defined study protocol has been proposed to explore disparities in breath research across different analytical platforms and to provide benchmark values for comparison. Specifically, the Peppermint Experiment involves the targeted analysis in exhaled breath of volatile constituents of peppermint oil after ingestion of the encapsulated oil. Data from the Peppermint Experiment performed by proton transfer reaction mass spectrometry (PTR-MS) and selected ion flow tube mass spectrometry (SIFT-MS) are presented and discussed herein, including the product ions associated with the key peppermint volatiles, namely limonene, α- and ÎČ-pinene, 1,8-cineole, menthol, menthone and menthofuran. The breath washout profiles of these compounds from 65 individuals were collected, comprising datasets from five PTR-MS and two SIFT-MS instruments. The washout profiles of these volatiles were evaluated by comparing the log-fold change over time of the product ion intensities associated with each volatile. Benchmark values were calculated from the lower 95% confidence interval of the linear time-to-washout regression analysis for all datasets combined. Benchmark washout values from PTR-MS analysis were 353 min for the sum of monoterpenes and 1,8-cineole (identical product ions), 173 min for menthol, 330 min for menthofuran, and 218 min for menthone; from SIFT-MS analysis values were 228 min for the sum of monoterpenes, 281 min for the sum of monoterpenes and 1,8-cineole, and 370 min for menthone plus 1,8-cineole. Large inter- and intra-dataset variations were observed, whereby the latter suggests that biological variability plays a key role in how the compounds are absorbed, metabolized and excreted from the body via breath. This variability seems large compared to the influence of sampling and analytical procedures, but further investigations are recommended to clarify the effects of these factors.openHenderson, Ben; Slingers, Gitte; Pedrotti, Michele; Pugliese, Giovanni; MalĂĄskovĂĄ, Michaela; Bryant, Luke; Lomonaco, Tommaso; Ghimenti, Silvia; Moreno, Sergi; Cordell, Rebecca; Harren, Frans J M; Schubert, Jochen; Mayhew, Chris A; Wilde, Michael; Di Francesco, Fabio; Koppen, Gudrun; Beauchamp, Jonathan D; Cristescu, Simona MHenderson, B.; Slingers, G.; Pedrotti, M.; Pugliese, G.; MalĂĄskovĂĄ, M.; Bryant, L.; Lomonaco, T.; Ghimenti, S.; Moreno, S.; Cordell, R.; Harren, F.J.M.; Schubert, J.; Mayhew, C.A.; Wilde, M.; Di Francesco, F.; Koppen, G.; Beauchamp, J.D.; Cristescu, S.M

    Scoliosis and dental occlusion: a review of the literature

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Idiopathic scoliosis is a deformity without clear etiology. It is unclear wether there is an association between malocclusion and scoliosis. Several types of occlusion were described in subjects with scoliosis, mostly case-reports.</p> <p>Objectives</p> <p>The aim of this review was to evaluate the type of occluslins more prevalent in subjects with scoliosis</p> <p>Search strategy</p> <p>All randomised and controlled clinical trials identified from the Cochrane Oral Health Group Trials Register, a MEDLINE search using the Mesh term scoliosis, malocclusion, and relevant free text words, and the bibliographies of papers and review articles which reported the outcome of orthodontic treatment in subjects with scoliosis that were published as abstracts or papers between 1970 and 2010.</p> <p>Selection criteria</p> <p>All randomised and controlled clinical trials published as full papers or abstracts which reported quantitative data on the outcomes malocclusion in subjects with scoliosis.</p> <p>Data collection and analysis</p> <p>Data were extracted without blinding to the authors, age of patients or type of occlusion.</p> <p>Main results</p> <p>Using the search strategy eleven observational longitudinal studies were identified. No randomized clinical trials were recorded. Twenty-three cross-sectional studies were recorderd, and the others studies were reviews, editorials, case-reports, or opinions. The clinical trials were often not controlled and were about the cephalometric evaluation after treatment with the modified Milwuakee brace, followed by the orthodontic treatment of the class II relationship with a functional appliance. Clinical trials also included the study of the associations between scoliosis and unilateral crossbite, in children with asymmetry of the upper cervical spine. This association was also investigated in rats, pigs and rabbits in clinical trials. The other associations between scoliosis and occlusion seems to be based only on cross-sectional studies, case-reports, opinions.</p> <p>Authors' conclusions</p> <p>Based on selected studies, this review concludes that there is plausible evidence for an increased prevalence of unilateral Angle Class II malocclusions associated with scoliosis, and an increased risk of lateral crossbite, midline deviation in children affected by scoliosis. Also, documentation of associations between reduced range of lateral movements and scoliosis seem convincing. Data are also mentioned about the association between plagiocephaly and scoliosis.</p

    The SUV4-20H Histone Methyltransferases in Health and Disease

    No full text
    The post-translational modification of histone tails is a dynamic process that provides chromatin with high plasticity. Histone modifications occur through the recruitment of nonhistone proteins to chromatin and have the potential to influence fundamental biological processes. Many recent studies have been directed at understanding the role of methylated lysine 20 of histone H4 (H4K20) in physiological and pathological processes. In this review, we will focus on the function and regulation of the histone methyltransferases SUV4-20H1 and SUV4-20H2, which catalyze the di- and tri-methylation of H4K20 at H4K20me2 and H4K20me3, respectively. We will highlight recent studies that have elucidated the functions of these enzymes in various biological processes, including DNA repair, cell cycle regulation, and DNA replication. We will also provide an overview of the pathological conditions associated with H4K20me2/3 misregulation as a result of mutations or the aberrant expression of SUV4-20H1 or SUV4-20H2. Finally, we will critically analyze the data supporting these functions and outline questions for future research

    The Iceman's lithic toolkit: Raw material, technology, typology and use.

    No full text
    The Tyrolean Iceman, a 5,300-year-old glacier mummy recovered at the Tisenjoch (South Tyrol, Italy) together with his clothes and personal equipment, represents a unique opportunity for prehistoric research. The present work examines the Iceman's tools which are made from chert or are related to chert working - dagger, two arrowheads, endscraper, borer, small flake and antler retoucher - and considers also the arrowhead still embedded in the shoulder of the mummy. The interdisciplinary results achieved by study of the lithic raw material, technology, use-wear analysis, CT analysis and typology all add new information to Ötzi's individual history and his last days, and allow insights into the way of life of Alpine Copper Age communities. The chert raw material of the small assemblage originates from at least three different areas of provenance in the Southalpine region. One, or possibly two, sources derive from outcrops in the Trentino, specifically the Non Valley. Such variability suggests an extensive provisioning network, not at all limited to the Lessini mountains, which was able to reach the local communities. The Iceman's toolkit displays typological characteristics of the Northern Italian tradition, but also comprises features typical of the Swiss Horgen culture, which will come as no surprise in the toolkit of a man who lived in a territory where transalpine contacts would have been of great importance. Ötzi was not a flintknapper, but he was able to resharpen his tools with a medium to good level of skill. Wear traces reveal that he was a right-hander. Most instruments in the toolkit had reached their final stage of usability, displaying extensive usage, mostly from plant working, resharpenings and breaks. Evidently Ötzi had not had any access to chert for quite some time, which must have been problematic during his last hectic days, preventing him from repairing and integrating his weapons, in particular his arrows. Freshly modified blade tools without any wear suggest planned work which he never carried out, possibly prevented by the events which made him return to the mountains where he was killed by a Southern Alpine archer

    The Iceman’s lithic toolkit: Raw material, technology, typology and use - Fig 19

    Get PDF
    <p>a-b) Arrowhead 12 (Scaglia Variegata Alpina, Trento Plateau). a) pale brown patina. The true grey to green chert color is visible in places; b) Microcrystalline chert matrix with planktic foraminifers - the species <i>Rotalipora cushmani</i> (1) and <i>Preglobotruncana</i> g<i>ibba</i> (2) are clearly recognizable - and radiolarians. Some microfossils have light reddish to brown fillings. c) Arrowhead 14 (Maiolica, Trento Plateau). Very clean and fine crystalline chert matrix incorporating whitish radiolarians.</p
    corecore