342 research outputs found

    Synthesis and evaluation of symmetrical biphenyltetrols as aggregation inhibitors for Alzheimer’s amyloid-β peptide

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    Inhibiting the aggregation of amyloid-beta peptide (Aβ) is one therapeutic target for the prevention and treatment of Alzheimer’s disease. We have previously demonstrated that biphenyl-3,3′,4,4′-tetrol (3,4-BPT) effectively abrogates Aβ aggregation at stoichiometric concentrations. To investigate molecular architecture and determine how the positioning of the hydroxyl hydrogen-bond donors impacts inhibitor efficacy, we have synthesized four additional symmetrical biphenyltetrols (2,3-, 2,4- 2,5- and 3,5-BPT). We have evaluated these inhibitors by means of Congo red and Thioflavin T dye-binding assays to monitor Aβ aggregation as a function of time and to determine inhibitor IC50 values for reducing equilibrium levels of aggregation. 2,3- and 2,5-BPT were observed to be promising inhibitors of Aβ aggregation: we have qualitatively assessed their IC50 values to be approximately 7X and 3-4X, respectively. In contrast, 2,4- and 3,5-BPT showed little to no inhibition. Thus, 2,5-BPT was the most successful of the four inhibitors evaluated, however; it was not as effective as 3,4-BPT, studied previously (IC50 = 1.0 ± 0.3X). The four isomers we have characterized exhibit a range of IC50 values spanning more than one order of magnitude, likely due to varying abilities to bind to A assemblies. Future work will involve further evaluation of the symmetrical biphenyltetrols, by methods including circular dichroism and transmission electron microscopy, which will afford greater insight into the Aβ assemblies formed in the presence and absence of inhibitors. These results will aid in the rational design of additional small-molecule aggregation inhibitors, including unsymmetrical biphenyltetrols and other architectures bearing hydroxyl substituents in those positions associated with the greatest inhibitory efficacy

    ”Musta se on vaa kiva, että se ylipäätään tulee sinne luokkaan”:opettajien ja oppilaiden käsityksiä koira-avusteisesta pedagogiikasta

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    Tiivistelmä. Tämän pro gradu -tutkielman tavoitteena on tarkastella koulukoiratoiminnan toteutusta sekä oppilaiden ja opettajien käsityksiä koulukoiratoiminnasta eräässä pohjoissuomalaisessa yhtenäiskoulussa. Tutkielman teoreettisessa viitekehyksessä esitellään eläinavusteisen ja koira-avusteisen toiminnan muotoja ja vaikutuksia sekä koiran roolia ja merkitystä kasvatustyössä aiemman tutkimuskirjallisuuden perusteella. Tutkimus toteutettiin fenomenografisena tapaustutkimuksena. Aineisto kerättiin tutkimuskoulun oppilailta, opettajilta ja koulukoiran ohjaajana toimivalta oppilashuollon työntekijältä teemahaastattelujen avulla. Haastatteluja toteutettiin yhteensä kymmenen, joista neljä oli oppilaiden ryhmähaastatteluja. Aineisto analysoitiin aineistolähtöisellä sisällönanalyysillä. Tutkimustulosten perusteella voidaan todeta, että sekä opettajien että oppilaiden käsitykset koulukoirasta ovat hyvin positiivisia ja koulukoira on saanut koululla myönteisen vastaanoton. Koulukoiran nähtiin parantavan oppilaan henkistä hyvinvointia, lisäävän iloa ja mielekkyyttä koulunkäyntiin, vahvistavan lapsen tunne- ja vuorovaikutustaitoja ja vähentävän häiriökäyttäytymistä. Opettajien mukaan koira luo hyväksyvää ja lämmintä tunnelmaa, mikä helpottaa vaikeistakin asioista puhumista ja siten tukee lapsen ja aikuisen välisen keskusteluyhteyden syntymistä. Koiran myös nähtiin tukevan tuntityöskentelyä, lisäävän motivaatiota sekä helpottavan erityisesti ääneen lukemista. Toisaalta erityisesti oppilaat kokivat koiran läsnäolon ja siitä johtuvan innostuksen myös jossain määrin heikentävän työrauhaa ja keskittymistä tuntitilanteissa. Tutkimuksen tulokset olivat suurimmalta osin linjassa aiemman tutkimustiedon kanssa. Tulosten perusteella voidaan päätellä, että koulukoiratoiminnan avulla on mahdollista tukea monipuolisesti oppilaan oppimista ja koulunkäyntiä sekä psyykkistä ja sosiaalista hyvinvointia. Lisäksi koulukoiran läsnäolo voi tutkimustulosten perusteella parantaa myös opettajan työhyvinvointia

    First measurements of the number size distribution of 1-2nm aerosol particles released from manufacturing processes in a cleanroom environment

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    This study was conducted to observe a potential formation and/or release of aerosol particles related to manufacturing processes inside a cleanroom. We introduce a novel technique to monitor airborne sub 2nm particles in the cleanroom and present results from a measurement campaign during which the total particle number concentration (>1nm and >7 nm) and the size resolved concentration in the 1 to 2nm size range were measured. Measurements were carried out in locations where atomic layer deposition (ALD), sputtering, and lithography processes were conducted, with a wide variety of starting materials. During our campaign in the clean room, we observed several time periods when the particle number concentration was 10(5) cm(-3) in the sub 2nm size range and 10(4) cm(-3) in the size class larger than 7nm in one of the sampling locations. The highest concentrations were related to the maintenance processes of the manufacturing machines, which were conducted regularly in that specific location. Our measurements show that around 500cm(-3) sub 2nm particles or clusters were in practice always present in this specific cleanroom, while the concentration of particles larger than 2nm was less than 2cm(-3). During active processes, the concentrations of sub 2nm particles could rise to over 10(5) cm(-3) due to an active new particle formation. The new particle formation was most likely induced by a combination of the supersaturated vapors, released from the machines, and the very low existing condensation sink, leading to pretty high formation rates J(1.4 nm) = (9 4) cm(-3) s(-1) and growth rates of particles (GR(1.1-1.3 nm) = (6 +/- 3) nm/h and GR(1.3-1.8 nm) = (14 +/- 3) nm/h).Copyright (c) 2017 American Association for Aerosol ResearchPeer reviewe

    Recent advances in the research of an endemic osteochondropathy in China: Kashin-Beck disease

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    SummaryKashin-Beck disease (KBD) is an endemic chronic osteochondral disease, which has a high prevalence and morbidity in the Eastern Siberia of Russia, and in the broad diagonal, northern-east to southern-west belt in China and North Korea. In 1990's, it was estimated that in China 1–3 million people had some degree of symptoms of the disease, although even higher estimates have been presented. In China, the extensive prevalence peaked in the late 1950's, but since then, in contrast to the global trend of the osteoarthritis (OA), the number of cases has been dramatically falling. Up to 2013, there are 0.64 millions patients with the KBD and 1.16 millions at risk in 377 counties of 13 provinces or autonomous regions. This is obviously thanks to the preventive efforts carried out, which include providing millions of people with dietary supplements and clean water, as well as relocation of whole villages in China. However, relatively little is known about the molecular mechanisms behind the cartilage damage, the genetic and the environmental risk factors, and the rationale of the preventive effects. During the last decade, new data on a cellular and molecular level has begun to accumulate, which hopefully will uncover the grounds of the disease

    Extra virgin olive oil phenol extracts exert hypocholesterolemic effects through the modulation of the LDLR pathway: In vitro and cellular mechanism of action elucidation

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    This study was aimed at investigating the hypocholesterolemic effects of extra virgin olive oil (EVOO) phenols and the mechanisms behind the effect. Two phenolic extracts were prepared from EVOO of different cultivars and analyzed using the International Olive Council (IOC) official method for total phenols, a recently validated hydrolytic procedure for total hydroxytyrosol and tyrosol, and 1H-NMR analysis in order to assess their secoiridoid profiles. Both of the extracts inhibited in vitro the 3-hydroxy-3-methylglutaryl co-enzyme A reductase (HMGCoAR) activity in a dose-dependent manner. After the treatment of human hepatic HepG2 cells (25 µg/mL), they increased the low-density lipoprotein (LDL) receptor protein levels through the activation of the sterol regulatory element binding proteins (SREBP)-2 transcription factor, leading to a better ability of HepG2 cells to uptake extracellular LDL molecules with a final hypocholesterolemic effect. Moreover, both of the extracts regulated the intracellular HMGCoAR activity through the increase of its phosphorylation by the activation of AMP-activated protein kinase (AMPK)-pathways. Unlike pravastatin, they did not produce any unfavorable effect on proprotein convertase subtilisin/kexin 9 (PCSK9) protein level. Finally, the fact that extracts with different secoiridoid profiles induce practically the same biological effects suggests that the hydroxytyrosol and tyrosol derivatives may have similar roles in hypocholesterolemic activity

    Extra virgin olive oil phenol extracts exert hypocholesterolemic effects through the modulation of the LDLR pathway: In vitro and cellular mechanism of action elucidation

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    This study was aimed at investigating the hypocholesterolemic effects of extra virgin olive oil (EVOO) phenols and the mechanisms behind the effect. Two phenolic extracts were prepared from EVOO of different cultivars and analyzed using the International Olive Council (IOC) official method for total phenols, a recently validated hydrolytic procedure for total hydroxytyrosol and tyrosol, and1 H-NMR analysis in order to assess their secoiridoid profiles. Both of the extracts inhibited in vitro the 3-hydroxy-3-methylglutaryl co-enzyme A reductase (HMGCoAR) activity in a dose-dependent manner. After the treatment of human hepatic HepG2 cells (25 µg/mL), they increased the low-density lipoprotein (LDL) receptor protein levels through the activation of the sterol regulatory element binding proteins (SREBP)-2 transcription factor, leading to a better ability of HepG2 cells to uptake extracellular LDL molecules with a final hypocholesterolemic effect. Moreover, both of the extracts regulated the intracellular HMGCoAR activity through the increase of its phosphorylation by the activation of AMP-activated protein kinase (AMPK)-pathways. Unlike pravastatin, they did not produce any unfavorable effect on proprotein convertase subtilisin/kexin 9 (PCSK9) protein level. Finally, the fact that extracts with different secoiridoid profiles induce practically the same biological effects suggests that the hydroxytyrosol and tyrosol derivatives may have similar roles in hypocholesterolemic activity

    Lupin protein exerts cholesterol-lowering effects targeting PCSK9: from clinical evidences to elucidation of the in vitro molecular mechanism using HepG2 cells

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    PCSK9 inhibition is a novel approach for cholesterol reduction because of its crucial pathophysiological role in cholesterol metabolism. This work aimed at evaluating whether lupin protein/peptides may modulate PCSK9 production. Mild hypercholesterolaemic subjects consumed lupin protein or casein (30 g/day) for 4 weeks. The final level of circulating PCSK9, measured by ELISA, was reduced by 8.5% (p = 0.0454) versus baseline value, whereas it remained unchanged in the control group (casein). For investigating the mechanism of action, HepG2 cells were treated with peptic and tryptic peptides from lupin protein: reductions of PCSK9 production and secretion were observed as well as a decrease of hepatic nuclear factor 1-alpha (HNF1-alpha). For the first time, this work provides evidences that lupin protein/peptides may modulate the PCSK9 protein level production and secretion, contributing to explain the beneficial effects observed in animal and human studies and opening a completely new area of investigation on plant proteins

    Virgin olive oil extracts reduce oxidative stress and modulate cholesterol metabolism: Comparison between oils obtained with traditional and innovative processes

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    This study was aimed at demonstrating the substantial equivalence of two extra virgin olive oil samples extracted from the same batch of Coratina olives with (OMU) or without (OMN) using ultrasound technology, by performing chemical, biochemical, and cellular investigations. The volatile organic compounds compositions and phenolic profiles were very similar, showing that, while increasing the extraction yields, the innovative process does not change these features. The antioxidant and hypocholesterolemic activities of the extra virgin olive oil (EVOO) phenol extracts were also preserved, since OMU and OMN had equivalent abilities to scavenge the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radicals in vitro and to protect HepG2 cells from oxidative stress induced by H2 O2, reducing intracellular reactive oxygen species (ROS) and lipid peroxidation levels. In addition, by inhibiting 3-hydroxy-3-methylglutarylcoenzyme a reductase, both samples modulated the low-density lipoprotein receptor (LDLR) pathway leading to increased LDLR protein levels and activity

    Repair of osteochondral defects with recombinant human type II collagen gel and autologous chondrocytes in rabbit

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    SummaryObjectiveRecombinant human type II collagen (rhCII) gels combined with autologous chondrocytes were tested as a scaffold for cartilage repair in rabbits in vivo.MethodAutologous chondrocytes were harvested, expanded and combined with rhCII-gel and further pre-cultivated for 2 weeks prior to transplantation into a 4 mm diameter lesion created into the rabbit's femoral trochlea (n = 8). Rabbits with similar untreated lesions (n = 7) served as a control group.ResultsSix months after the transplantation the repair tissue in both groups filled the lesion site, but in the rhCII-repair the filling was more complete. Both repair groups also had high proteoglycan and type II collagen contents, except in the fibrous superficial layer. However, the integration to the adjacent cartilage was incomplete. The O'Driscoll grading showed no significant differences between the rhCII-repair and spontaneous repair, both representing lower quality than intact cartilage. In the repair tissues the collagen fibers were abnormally organized and oriented. No dramatic changes were detected in the subchondral bone structure. The repair cartilage was mechanically softer than the intact tissue. Spontaneously repaired tissue showed lower values of equilibrium and dynamic modulus than the rhCII-repair. However, the differences in the mechanical properties between all three groups were insignificant.ConclusionWhen rhCII was used to repair cartilage defects, the repair quality was histologically incomplete, but still the rhCII-repairs showed moderate mechanical characteristics and a slight improvement over those in spontaneous repair. Therefore, further studies using rhCII for cartilage repair with emphasis on improving integration and surface protection are required

    Phenolic extracts from extra virgin olive oils inhibit dipeptidyl peptidase iv activity: In vitro, cellular, and in silico molecular modeling investigations

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    Two extra virgin olive oil (EVOO) phenolic extracts (BUO and OMN) modulate DPP-IV activity. The in vitro DPP-IV activity assay was performed at the concentrations of 1, 10, 100, 500, and 1000 μg/mL, showing a dose-dependent inhibition by 6.8 ± 1.9, 17.4 ± 6.1, 37.9 ± 2.4, 57.8 ± 2.9, and 81 ± 1.4% for BUO and by 5.4 ± 1.7, 8.9 ± 0.4, 28.4 ± 7.2, 52 ± 1.3, and 77.5 ± 3.5% for OMN. Moreover, both BUO and OMN reduced the DPP-IV activity expressed by Caco-2 cells by 2.9 ± 0.7, 44.4 ± 0.7, 61.2 ± 1.8, and 85 ± 4.2% and by 3 ± 1.9, 35 ± 9.4, 60 ± 7.2, and 82 ± 2.8%, respectively, at the same doses. The concentration of the most abundant and representative secoiridoids within both extracts was analyzed by nuclear magnetic resonance ((1)H-NMR). Oleuropein, oleacein, oleocanthal, hydroxytyrosol, and tyrosol, tested alone, reduced the DPP-IV activity, with IC(50) of 472.3 ± 21.7, 187 ± 11.4, 354.5 ± 12.7, 741.6 ± 35.7, and 1112 ± 55.6 µM, respectively. Finally, in silico molecular docking simulations permitted the study of the binding mode of these compounds
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