Célia Antunes | Universidade de Évora (original) (raw)

Papers by Célia Antunes

Synthesis, Jun 8, 2022

Twenty-three new quercetin-1,2,3-triazole hybrids were synthesized in good to quantitative yields... more Twenty-three new quercetin-1,2,3-triazole hybrids were synthesized in good to quantitative yields via Cu(I)-catalyzed azidealkyne cycloaddition reaction under microwave irradiation. These new hybrids contain a 1,4-disubstituted 1,2,3-triazole ring at the 3-OH position of quercetin whilst the remaining hydroxyl groups were either protected as methyl or benzyl groups or left unprotected. All the quercetin-1,2,3-triazole hybrids I-IV were evaluated against REM-134 canine mammary cancer cell line, which is used as a translational model for human breast cancer. These new analogues exhibit potent antiproliferative activity against this cancer cell line. Furthermore, the results show that some of the new quercetin-1,2,3-triazole hybrids have better activity than quercetin. Our best inhibitors displayed IC 50 values in the range of 41-180 nM, and undoubtedly will have an important impact on the treatment of both canine and human breast cancer.

Diabetes, Dec 1, 2000

Although isolated rat islets are widely used to study in vitro insulin secretion and the underlyi... more Although isolated rat islets are widely used to study in vitro insulin secretion and the underlying metabolic and ionic processes, knowledge on the properties of glucose-induced electrical activity (GIEA), a key step in glucose-response coupling, has been gathered almost exclusively from microdissected mouse islets. Using a modified intracellular recording technique, we have now compared the patterns of GIEA in collagenase-isolated rat and mouse islets. Resting membrane potentials of rat and mouse ␤-cells were approximately-50 and-60 mV, respectively. Both rat and mouse ␤-cells displayed prompt membrane depolarizations in response to glucose. However, whereas the latter exhibited a bursting pattern consisting of alternating hyperpolarized and depolarized active phases, rat ␤-cells fired action potentials from a nonoscillating membrane potential at all glucose concentrations (8.4-22.0 mmol/l). This was mirrored by changes in the intracellular Ca 2+ concentration ([Ca 2+ ] i), which was oscillatory in mouse and nonoscillatory in rat islets. Stimulated rat ␤-cells were strongly hyperpolarized by diazoxide, an activator of ATP-dependent K + channels. Glucose evoked dosedependent depolarizations and [Ca 2+ ] i increases in both rat (EC 50 5.9-6.9 mmol/l) and mouse islets (EC 50 8.3-9.5 mmol/l), although it did not affect the burst plateau potential in the latter case. We conclude that there are important differences between ␤-cells from both species with respect to early steps in the stimulussecretion coupling cascade based on the following findings: 1) mouse ␤-cells have a larger resting K + conductance in 2 mmol/l glucose, 2) rat ␤-cells lack the compensatory mechanism responsible for generating membrane potential oscillations and holding the depolarized plateau potential in mouse ␤-cells, and 3) the electrical and [Ca 2+ ] i dose-response curves in rat ␤-cells are shifted toward lower glucose concentrations. Exploring the molecular basis of these differences may clarify several a priori assumptions on the electrophysiological properties of rat ␤-cells, which could foster the development of new working models of pancreatic ␤-cell function.

Antibiotics

Antimicrobial resistance is a serious problem for the control of infections and infectious diseas... more Antimicrobial resistance is a serious problem for the control of infections and infectious diseases. Propolis is a substance produced by honeybees with antimicrobial and antibiofilm properties. To consider propolis as an alternative to the use of antimicrobials for infection control, we assessed its antimicrobial and antibiofilm activities. To assess propolis for topical medical use, toxicological studies were also performed. A Portuguese 70% propolis ethanolic extract was chemically evaluated and studied for antimicrobial activity on staphylococcal field isolates (n = 137) and antibiofilm action (n = 45). Cell toxicological assessment was performed using keratinocytes and fibroblasts. Pinobanksin, chrysin, acacetin, apigenin, pinocembrin, and kaempferol-dimethyl-ether were detected. All 137 isolates were susceptible to 6.68 mg/mL or lower propolis concentration (80% isolates were susceptible to <1 mg/mL). The mean percentage of biofilm inhibition was 71%, and biofilm disruption ...

BioChem

Skin is one of the organs most tested for toxicity and safety evaluation during the process of dr... more Skin is one of the organs most tested for toxicity and safety evaluation during the process of drug research and development and in the past has usually been performed in vivo using animals. Over the last few years, non-animal alternatives have been developed and validated epidermis models for human and rat skin are already available. Our goal was to develop a histotypical canine skin analog, suitable for non-animal biocompatibility and biosafety assessment. Canine keratinocytes were seeded in an air-lift culture using an adapted version of the CELLnTEC protocol. Corrosion and irritation protocols were adapted from human EpiSkinTM. For histological analysis, sample biopsies were fixed in neutral-buffered formalin, and paraffin slices were routinely processed and stained with hematoxylin and eosin. A canine multilayer and stratified epidermal-like tissue (cEpiderm), confirmed by histological analysis, was obtained. The cEpiderm tissue exhibited normal morphological and functional cha...

Aerobiologia

Pollen monitoring has traditionally been carried out using manual methods first developed in the ... more Pollen monitoring has traditionally been carried out using manual methods first developed in the early 1950s. Although this technique has been recently standardised, it suffers from several drawbacks, notably data usually only being available with a delay of 3–9 days and usually delivered at a daily resolution. Several automatic instruments have come on to the market over the past few years, with more new devices also under development. This paper provides a comprehensive overview of all available and developing automatic instruments, how they measure, how they identify airborne pollen, what impacts measurement quality, as well as what potential there is for further advancement in the field of bioaerosol monitoring.

Trends in Food Science & Technology, 2019

Background: Before introducing proteins from new or alternative dietary sources into the market, ... more Background: Before introducing proteins from new or alternative dietary sources into the market, a compressive risk assessment including food allergic sensitization should be carried out in order to ensure their safety. We have recently proposed the adverse outcome pathway (AOP) concept to structure the current mechanistic understanding of the molecular and cellular pathways evidenced to drive IgE-mediated food allergies. This AOP framework offers the biological context to collect and structure existing in vitro methods and to identify missing assays to evaluate sensitizing potential of food proteins. Scope and approach: In this review, we provide a state-of-the-art overview of available in vitro approaches for assessing the sensitizing potential of food proteins, including their strengths and limitations. These approaches are structured by their potential to evaluate the molecular initiating and key events driving food sensitization. Key findings and conclusions: The application of the AOP framework offers the opportunity to anchor existing testing methods to specific building blocks of the AOP for food sensitization. In general, in vitro methods evaluating mechanisms involved in the innate immune response are easier to address than assays addressing the adaptive immune response due to the low precursor frequency of allergen-specific T and B cells. Novel ex vivo culture strategies may have the potential to become useful tools for investigating the sensitizing potential of food proteins. When applied in the context of an integrated testing strategy, the described approaches may reduce, if not replace, current animal testing approaches.

Clinical and Translational Allergy, 2018

Background: Ambient air quality monitoring is a governmental duty that is widely carried out in o... more Background: Ambient air quality monitoring is a governmental duty that is widely carried out in order to detect non-biological ("chemical") components in ambient air, such as particles of < 10 µm (PM 10 , PM 2.5), ozone, sulphur dioxide, and nitrogen oxides. These monitoring networks are publicly funded and air quality data are open to the public. The situation for biological particles that have detrimental effects on health, as is the case of pollen and fungal spores, is however very different. Most pollen and spore monitoring networks are not publicly funded and data are not freely available. The information regarding which biological particle is being monitored, where and by whom, is consequently often not known, even by aerobiologists themselves. This is a considerable problem, as local pollen data are an important tool for the prevention of allergic symptoms. Objective: The aim of this study was to review pollen monitoring stations throughout the world and to create an interactive visualization of their distribution. Methods: The method employed to collect information was based on: (a) a review of the recent and historical bibliography related to pollen and fungal spore monitoring, and (b) personal surveys of the managers of national and regional monitoring networks. The interactive application was developed using the R programming language. Results: We have created an inventory of the active pollen and spore monitoring stations in the world. There are at least 879 active pollen monitoring stations in the world, most of which are in Europe (> 500). The prevalent monitoring method is based on the Hirst principle (> 600 stations). The inventory is visualised as an interactive and on-line map. It can be searched, its appearance can be adjusted to the users' needs and it is updated regularly, as new stations or changes to those that already exist can be submitted online. Conclusions: The map shows the current situation of pollen and spore monitoring and facilitates collaboration among those individuals who are interested in pollen and spore counts. It might also help to improve the monitoring of biological particles up to the current level employed for non-biological components.

Toxicology Letters, 2015

Background: The introduction of whole new foods in a population may lead to sensitization and foo... more Background: The introduction of whole new foods in a population may lead to sensitization and food allergy. This constitutes a potential public health problem and a challenge to risk assessors and managers as the existing understanding of the pathophysiological processes and the currently available biological tools for prediction of the risk for food allergy development and the severity of the reaction are not sufficient. There is a substantial body of in vivo and in vitro data describing molecular and cellular events potentially involved in food sensitization. However, these events have not been organized in a sequence of related events that is plausible to result in sensitization, and useful to challenge current hypotheses. The aim of this manuscript was to collect and structure the current mechanistic understanding of sensitization induction to food proteins by applying the concept of adverse outcome pathway (AOP). Main body: The proposed AOP for food sensitization is based on information on molecular and cellular mechanisms and pathways evidenced to be involved in sensitization by food and food proteins and uses the AOPs for chemical skin sensitization and respiratory sensitization induction as templates. Available mechanistic data on protein respiratory sensitization were included to fill out gaps in the understanding of how proteins may affect cells, cell-cell interactions and tissue homeostasis. Analysis revealed several key events (KE) and biomarkers that may have potential use in testing and assessment of proteins for their sensitizing potential. Conclusion: The application of the AOP concept to structure mechanistic in vivo and in vitro knowledge has made it possible to identify a number of methods, each addressing a specific KE, that provide information about the food allergenic potential of new proteins. When applied in the context of an integrated strategy these methods may reduce, if not replace, current animal testing approaches. The proposed AOP will be shared at the www.aopwiki.org platform to expand the mechanistic data, improve the confidence in each of the proposed KE and key event relations (KERs), and allow for the identification of new, or refinement of established KE and KERs.

Introduction. Exposure to allergens is pivotal in determining sensitization and allergic symptoms... more Introduction. Exposure to allergens is pivotal in determining sensitization and allergic symptoms in individuals. Pollen grain counts in ambient air have traditionally been assessed to estimate airborne allergen exposure. however, the exact allergen content in ambient air is unknown. hIALINE therefore monitored atmospheric concentrations of Betula, Poaceae and Olea pollen grains and matched their major allergens Bet v1, Phl p5 and Ole e1 across Europe. Monitoring the allergens themselves together with pollen in ambient air might be an improvement in allergen exposure assessment. New knowledge through the use of new experimental approaches in the field of aerobiological monitoring will enable better in the prevention and clinical management of pollinosis. In order to disseminate the knowledge of the project we present the results of first year of birch pollen grains and the matched major pollen allergen Bet v1 monitored in Parma (UNIPR), Italy with a short reference to the results obtained by the other participants and about developing models of dissemination and forecasts of pollen and allergens. Materials and methods. The pollen was sampled by a hirst pollen trap. Allergens was collected with a ChEMVOL ® high-volume cascade impactor, extracted from pollen and quantified by ELISA. Antibodies for analysis of Bet v1 are delivered by the industrial partner in this project. Quality control has been carried out for the monitoring pollen activities and allergen concentrations. Results. The project has highlighted that it is possible also to measure pollen allergen in ambient air in different European areas. The results obtained from the center of Parma and other European partners have highlighted the different allergenic powers of pollen of Betula, in different geographical areas. Moreover, daily in each area the allergenic power of pollen grains was very variable. Discussion. hIALINE has been a very important project to understand the mechanisms of sensitization, clinical management of pollinosis and to improve immunotherapy towards a tailored immunotherapy. The results of the project will help medical doctors, authorities and patients, to better manage the different aspects related to pollinosis.

Antunes, CM (Depto. Química, Universidade de Évora; CNBC, Coimbra); Caldeira, T.(Depto. Química, ... more Antunes, CM (Depto. Química, Universidade de Évora; CNBC, Coimbra); Caldeira, T.(Depto. Química, Centro de Química; Universidade de Évora) Martins, MR (Depto. Química, ICAM, Universidade de Évora; Munhoz, V.(Universidade de Évora, Portugal) Thibaudon, M.( ...

Date: August 25 Place: Room 5234 (oral), Room 6310 (poster) Organizers: Norio Sahashi, Jae-Won Oh... more Date: August 25 Place: Room 5234 (oral), Room 6310 (poster) Organizers: Norio Sahashi, Jae-Won Oh, Carmen Galán & Teiji Kondo Contact email address: sahashi@phar.toho-u.ac.jp Purpose: 1. Clarify correlation with annual change and the seasonal variation of the allergenic pollen and spore, and the climate factors. 2. Compare the latest scattering tendency in the different location, and the characteristic scattering pattern by the area exists or not. 3. Explore the compatibility from comparison of the scattering pattern by the gravitational method and the volumetric one. 4. Verify correlation by hourly scattering pattern by automatic monitoring device and climate factor

Allergy, 2013

Pollen is routinely monitored, but it is unknown whether pollen counts represent allergen exposur... more Pollen is routinely monitored, but it is unknown whether pollen counts represent allergen exposure. We therefore simultaneously determined olive pollen and Ole e 1 in ambient air in Córdoba, Spain, and Évora, Portugal, using Hirst‐type traps for pollen and high‐volume cascade impactors for allergen.Pollen from different days released 12‐fold different amounts of Ole e 1 per pollen (both locations P < 0.001). Average allergen release from pollen (pollen potency) was much higher in Córdoba (3.9 pg Ole e 1/pollen) than in Évora (0.8 pg Ole e 1/pollen, P = 0.004). Indeed, yearly olive pollen counts in Córdoba were 2.4 times higher than in Évora, but Ole e 1 concentrations were 7.6 times higher. When modeling the origin of the pollen, >40% of Ole e 1 exposure in Évora was explained by high‐potency pollen originating from the south of Spain. Thus, olive pollen can vary substantially in allergen release, even though they are morphologically identical.

Atmospheric Environment, 2012

Introduction: Cutaneous adverse food reactions are a current problem in dogs, with beef, dairy pr... more Introduction: Cutaneous adverse food reactions are a current problem in dogs, with beef, dairy products, chicken and wheat as the most implicated food components. As in humans, cutaneous and serological tests do not show enough individual diagnostic reliability for the diagnosis of food allergy. A wider diagnosis approach, including dietary restriction-provocation trials, is often necessary. Methods: From 85 dogs attending the Veterinary Hospital of the University of Évora (Portugal) and Rof Codina University Hospital (Lugo, Spain) outpatient consultations, 11 (5 males and 6 females) were selected by means of clinical inquiry and IDT for probable food allergy. All of them presented with pruritic dermatitis and at least 6 of the Favrot’s criteria for atopic dermatitis. None of them showed noticeable digestive signs. IDT were performed for D. glomerata, P. pratense, D. farinae, D. pteronyssinus, A. siro, T. putrescentiae, L. destructor, beef, pork, lamb, chicken, egg and milk. Specific IgE panels were determined in a commercial lab for pollens, molds and mites. Assessment of specific IgE for beef, pork, lamb, chicken, egg and milk was performed in Dot Blots with mouse anti-dog IgE McAb. Results: Mean specific IgE (EAU) was Dac g=547, Phl p=601, Der f=1665, Der p=297, Aca s=2063, Tyr p=1644 and Lep d=105. IDT were found positive in 4 patients (Dac g), 3 (Phl p), 5 (Der f), 6 (Der p), 4 (Aca s), 1 (Tyr p), 3 (Lep d), 10 (beef), 5 (pork), 5 (lamb), 6 (chicken), 4 (egg) and 2 (milk). Specific IgE Dot Blots showed positive for all patients to beef, pork and lamb, and in 8 of them to chicken. Semi-quantitation was found possible in Dot Blots. Strong positive correlation was observed between specific IgE and IDT to Der p (p=0.048), IDT and Dot Blots to beef (p=0.015) and to chicken (p=0.0003), and the intensity of Dot Blots between beef and lamb (p=0.006). Semi-quantitative difference was found between meat sources for mean IDT/Dot Blots scores: beef (3.2/3.73), pork (3/3.27), lamb (1.8/2.91) and chicken (1.8/1.3). In dogs presenting positive IDT to beef, pork, lamb or chicken, avoidance of those specific meats was recommended, with significant clinical improvement, especially when beef or chicken were implicated. Conclusion: IDT and specific IgE as less invasive and quicker diagnosis tools, may, along with dietary restriction-provocation trials, be useful for the diagnosis of food allergy as in several clinical cases positive results revealed to be predictive

Case Reports in Radiology

Ovarian cancer is the most fatal gynecologic malignancy. The incidence of ovarian cancer among fe... more Ovarian cancer is the most fatal gynecologic malignancy. The incidence of ovarian cancer among female-to-male transsexuals receiving treatment with testosterone is unknown, and few cases have been reported in the literature. We report a recent case in our institution, a 23-year-old female-to-male transsexual patient who received testosterone supplementation. The patient underwent a pelvic magnetic resonance imaging to study an ovarian complex cyst that revealed the presence of a bilateral ovarian tumor with imaging features of borderline serous tumor. These masses were surgically removed and the pathology report confirmed the diagnosis associated with noninvasive peritoneal implants and the presence of numerous androgen receptors in the tumor cells. Although there is still insufficient data to validate a direct correlation between hormonotherapy and ovarian cancer in these patients, this case may reinforce previous reports on this association and highlights the relevance of radiolog...

Munhoz, V. (Universidade de Évora, Portugal); Martins, R. (Depto. Química, ICAM, Universidade de ... more Munhoz, V. (Universidade de Évora, Portugal); Martins, R. (Depto. Química, ICAM, Universidade de Évora); Caldeira, A. (Depto. Química, Centro de Química; Universidade de Évora); Antunes, C.M. (Depto. Química, Universidade de Évora; CNBC, Coimbra); Caeiro, E. (Depto. Biologia, Universidade de Évora), Carvalho, E. (Bertin Technologies, France); Brandao, R. (Depto. Biologia, ICAM, Universidade de Évora); Email Adress: ruibrand@uevora.pt Correspondence address: Depto. Biologia, Universidade de Évora, P-7000 Évora, Portugal

Poster: "ECR 2010 / C-1677 / Volvulus characterization in radiology: A review" by: &quo... more Poster: "ECR 2010 / C-1677 / Volvulus characterization in radiology: A review" by: "C. Antunes, M. Seco, A. Canelas, C. Ruivo, C. Paulino, F. Cruz, F. Caseiro Alves; Coimbra/PT"