50 research outputs found
Infection with carcinogenic helminth parasites and its production of metabolites induces the formation of DNA-adducts
Background: Infections classified as group 1 biological carcinogens include the helminthiases caused by Schistosoma haematobium and Opisthorchis viverrini. The molecular mediators underlying the infection with these parasites and cancer remain unclear. Although carcinogenesis is a multistep process, we have postulated that these parasites release metabolites including oxysterols and estrogen-like metabolites that interact with host cell DNA. How and why the parasite produce/excrete these metabolites remain unclear. A gene encoding a CYP enzyme was identified in schistosomes and opisthorchiids. Therefore, it is reasonable hypothesized that CYP 450 might play a role in generation of pro-inflammatory and potentially carcinogenic compounds produced by helminth parasites such as oxysterols and catechol estrogens. Here, we performed enzymatic assays using several isoforms of CYP 450 as CYP1A1, 2E1 and 3A4 which are involved in the metabolism of chemical carcinogens that have been associated with several cancer. The main aim was the analysis of the role of these enzymes in production of helminth-associated metabolites and DNA-adducts.
Method: The effect of cytochrome P450 enzymes CYP 1A1, 2E1 and 3A4 during the interaction between DNA, glycocholic acid and taurochenodeoxycholate sodium on the formation of DNA-adducts and metabolites associated with urogenital schistosomiasis (UGS) and opisthorchiasis was investigated in vitro. Liquid chromatography/mass spectrometry was used to detect and identify metabolites.
Main findings: Through the enzymatic assays we provide a deeper understanding of how metabolites derived from helminths are formed and the influence of CYP 450. The assays using compounds similar to those previously observed in helminths as glycocholic acid and taurochenodeoxycholate sodium, allowed the detection of metabolites in their oxidized form and their with DNA. Remarkably, these metabolites were previously associated with schistosomiaisis and opisthorchiasis. Thus, in the future, it may be possible to synthesize this type of metabolites through this methodology and use them in cell lines to clarify the carcinogenesis process associated with these diseases.
Principal conclusions: Metabolites similar to those detected in helminths are able to interact with DNA in vitro leading to the formation of DNA adducts. These evidences supported the previous postulate that imply helminth-like metabolites as initiators of helminthiases-associated carcinogenesis. Nonetheless, studies including these kinds of metabolites and cell lines in order to evaluate its potential carcinogenic are required.This work was financed by FEDER - Fundo Europeu de Desenvolvimento
Regional funds through the COMPETE 2020 - Operacional Programme for
Competitiveness and Internationalisation (POCI), Portugal 2020, and by
Portuguese funds through FCT - Fundação para a Ciência e a Tecnologia, in
the framework of the project, Institute for Research and Innovation in Health
Sciences” (POCI-01-0145-FEDER-007274). The FCT and FEDER (European
Union) also supported these studies through project number IF/00092/2014/CP1255/CT0004info:eu-repo/semantics/publishedVersio
Human-robot collaboration (HRC) with vision inspection for PCB assembly
Flexibility and speed in the development of new industrial machines are essential factors for the success of capital goods industries. When assembling a printed circuit board (PCB), since all the components are surface-mounted devices (SMD), the whole process is automatic. However, in many PCBs, it is necessary to place components that are not SMDs, called pin through-hole components (PTH), having to be inserted manually, which leads to delays in the production line. This work proposes and validates a prototype work cell based on a collaborative robot and vision systems whose objective is to insert these components in a completely autonomous or semi-autonomous way. Different tests were made to validate this work cell, showing the correct implementation and the possibility of replacing the human worker on this PCB assembly task.ERDF - European Regional Development Fund(45070
Study of Tau-pair Production in Photon-Photon Collisions at LEP and Limits on the Anomalous Electromagnetic Moments of the Tau Lepton
Tau-pair production in the process e+e- -> e+e-tau+tau- was studied using
data collected by the DELPHI experiment at LEP2 during the years 1997 - 2000.
The corresponding integrated luminosity is 650 pb^{-1}. The values of the
cross-section obtained are found to be in agreement with QED predictions.
Limits on the anomalous magnetic and electric dipole moments of the tau lepton
are deduced.Comment: 20 pages, 9 figures, Accepted by Eur. Phys. J.
CP asymmetry in in a general two-Higgs-doublet model with fourth-generation quarks
We discuss the time-dependent CP asymmetry of decay in an
extension of the Standard Model with both two Higgs doublets and additional
fourth-generation quarks. We show that although the Standard Model with
two-Higgs-doublet and the Standard model with fourth generation quarks alone
are not likely to largely change the effective from the decay of
, the model with both additional Higgs doublet and
fourth-generation quarks can easily account for the possible large negative
value of without conflicting with other experimental
constraints. In this model, additional large CP violating effects may arise
from the flavor changing Yukawa interactions between neutral Higgs bosons and
the heavy fourth generation down type quark, which can modify the QCD penguin
contributions. With the constraints obtained from processes
such as and , this model can lead to the
effective to be as large as in the CP asymmetry of .Comment: 13 pages, 5 figures, references added, to appear in Eur.Phys.J.
Energy dependence of Cronin momentum in saturation model for and collisions
We calculate dependence of Cronin momentum for and
collisions in saturation model. We show that this dependence is consistent with
expectation from formula which was obtained using simple dimentional
consideration. This can be used to test validity of saturation model (and
distinguish among its variants) and measure dependence of saturation
momentum from experimental data.Comment: LaTeX2e, 12 pages, 8 figure
A Precise Measurement of the Tau Lifetime
The tau lepton lifetime has been measured with the e+e- -> tau+tau- events
collected by the DELPHI detector at LEP in the years 1991-1995. Three different
methods have been exploited, using both one-prong and three-prong tau decay
channels. Two measurements have been made using events in which both taus decay
to a single charged particle. Combining these measurements gave tau_tau (1
prong) = 291.8 +/- 2.3 (stat) +/- 1.5 (sys) fs. A third measurement using taus
which decayed to three charged particles yielded tau_tau (3 prong) = 288.6 +/-
2.4 (stat) +/- 1.3 (sys) fs. These were combined with previous DELPHI results
to measure the tau lifetime, using the full LEP1 data sample, to be tau_tau =
290.9 +/- 1.4 (stat) +/- 1.0 (sys) fs.Comment: 27 pages, 7 figure
Priming with mindfulness affects our capacity to self-regulate brain activity?
Self-regulation (SR) is a vital adaptation process to environmental and social challenges. Indispensable in our growing hyper-technological and hyper-stimulative society. SR deficits are associated with diverse behavioral problems and mental disorders such as depression, rumination, distraction, anxiety, stress, and attention control. Neurofeedback Training (NFT) is one of the techniques to train brain self-regulation (BSR). In the current protocols, the benefits from NFT greatly differ between subjects, with a high percentage of inefficacy. Therefore, understanding how to prime self-regulation could be the key to unlock predictors and optimize the success of Neurofeedback modulation, and vice-versa. Literature hypothesizes that the 'optimal' state of SR learning is reached when irrelevant associations between internal states and external reward are avoided, and when the learner stays engaged, focused and undistracted. Thus, suggesting a close relation to focused attention forms of mindfulness meditation (MM). As such, to promote this 'optimal' self-regulation on an NFT protocol, we implemented a human-computer framework to assist the subject to voluntary modulate their brain activity. The assistance was done by priming the subject with mindfulness guided instructions right before the NFT. In conclusion, conducting this intervention was the first step to determine if priming with external neurostimulation would enhance Neurofeedback self-regulation.INCT-EN - Instituto Nacional de Ciência e Tecnologia para Excitotoxicidade e Neuroproteção(PD/BD/114033/2015)The author was supported by Fundação Para a Ciência e Tecnologia
(FCT) grant number PD/BD/114033/2015 (in the scope of the MIT PhD
Program in Bioengineering Systems). This work has been partially supported
by COMPETE: POCI-01-0145-FEDER-007043 and by FCT – Fundação
para a Ciência e Tecnologia within the R&D Units Project Scope:
UIDB/00319/2020
Solution behaviour of lead(II) carboxylates in organic solvents
The solution behaviour has been studied of a series of even chain length lead(II) carboxylates (octanoate to octadecanoate) and the odd chain length lead(II) heptadecanoate in a variety of non-complexing organic solvents and in alcohols. In agreement with previous studies, solubility increases dramatically above a certain temperature, which depends on solute concentration, chain length and solvent. This solution temperature is also affected by traces of water. These results are complemented by studies using vapour pressure osmometry, dynamic light scattering, 1H and 13NMR spectroscopy. The results in water-free systems are consistent with the formation of rather ill-defined, polydisperse aggregates, which increase in size with concentration and decrease with temperature. These show similar local structure to lamellar mesophases in the pure lead(II) carboxylates, and are suggested to be formed by solvent induced swelling and break-up of these mesophases. In the presence of water, a more ordered structure is formed, in which a few water molecules are suggested to be bound to the lead(II) carboxylate headgroup.http://www.sciencedirect.com/science/article/B6TFR-4DBSWVR-4/1/1d162aa4a64b22ac874987e1f7c9cb3