Percorrer por autor "Oliveira, Ana Cebola"
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- Assessment of toxigenic fungi in poultry feedPublication . Viegas, Carla; Pacífico, Cátia; Faria, Tiago; Oliveira, Ana Cebola; Gomes, Anita Quintal; Viegas, SusanaIntroduction - Feed supplies the necessary nutrients for the growth of healthy animals, which are a part of the human diet. The presence of toxigenic fungi in animal feed such as Aspergillus spp. may contribute to 1) the loss of nutritional value of feedstuff, since fungi will assimilate the most readily available nutrients present in the feed, and 2) the development of mycotoxicoses and chronic conditions, which can raise economic issues due to animal disease and contamination of animal derived products. Aim of the study - The goal of this work was to evaluate the incidence of Aspergilli, particularly from the Circumdati, Flavi and Fumigati sections, through real-time quantitative PCR (qPCR) in 11 feed samples.
- Exposure to chemical mixtures in occupational settings: a reality in oncology day services?Publication . Viegas, Susana; Oliveira, Ana Cebola; Pádua, MárioAntineoplastic drugs are essential to cancer treatment. Its widespread use in hospitals leads to an increased probability of occupational exposure of the healthcare professionals that manipulate the drugs. The fact that chemotherapy involves administration of multiple drugs only amplifies the problem resulting in the possible occupational exposure to a misture of these chemicals.The aim of this study was to determine the surfaces contamination by antineoplastic drugs in one Oncology Day Service and understand if it promotes exposure to chemical mixtures. Selected workplaces surfaces were wipe-sampled. 5-Fluorouracil, Paclitaxel (TM) and Cyclophosphamide in the samples were simultaneously analyzed by HPLC-DAD. Of the 45 collected samples, 4.4% were not contaminated, 40% presented contamination by only one drug and 55.6% showed contamination by more than one drug. The study allows the recognition that workers are exposed to mixtures of drugs. Interactions between drugs can be a reality and this justifies further research to support a cumulative risk assessment.
- Fungal contamination in coffee samples: a public health concernPublication . Viegas, Carla; Pacífico, Cátia; Faria, Tiago; Oliveira, Ana Cebola; Gomes, Anita Quintal; Viegas, SusanaIntroduction - Fungi are natural coffee contaminants and under certain environmental conditions have the potential to produce toxins. Many studies revealed that the important toxigenic fungal genera (Aspergillus and Penicillium) are natural coffee contaminants, and are present from the field to storage. Aspergilli from the Circumdati and Nigri sections are known to produce high levels of ochratoxin A, a mycotoxin known as nephrotoxic for animals and humans. This work aimed to evaluate fungal distribution and also the prevalence of Aspergillus sections Fumigati, Flavi, Nigri and Circumdati from Coffea arabica (Arabica coffee) and Coffea canephora (Robusta coffee) green samples.
- Fungal contamination in green coffee beans samples: a public health concernPublication . Viegas, Carla; Pacífico, Cátia; Faria, Tiago; Oliveira, Ana Cebola; Caetano, Liliana Aranha; Carolino, Elisabete; Gomes, Anita Quintal; Viegas, SusanaStudies on the microbiology of coffee cherries and beans have shown that the predominant toxigenic fungal genera (Aspergillus and Penicillium) are natural coffee contaminants. The aim of this study was to investigate the distribution of fungi in Coffea arabica L. (Arabica coffee) and Coffea canephora L. var. robusta (Robusta coffee) green coffee samples obtained from different sources at the pre-roasting stage. Twenty-eight green coffee samples from different countries of origin (Brazil, Timor, Honduras, Angola, Vietnam, Costa Rica, Colombia, Guatemala, Nicaragua, India, and Uganda) were evaluated. The fungal load in the contaminated samples ranged from 0 to 12330 colony forming units (CFU)/g, of which approximately 67% presented contamination levels below 1500 CFU/g, while 11% exhibited intermediate contamination levels between 1500 and 3000 CFU/g. Contamination levels higher than 3000 CFU/g were found in 22% of contaminated coffee samples. Fifteen different fungi were isolated by culture-based methods and Aspergillus species belonging to different sections (complexes). The predominant Aspergillus section detected was Nigri (39%), followed by Aspergillus section Circumdati (29%). Molecular analysis detected the presence of Aspergillus sections Fumigati and Circumdati. The% coffee samples where Aspergillus species were identified by culture-based methods were 96%. Data demonstrated that green coffee beans samples were contaminated with toxigenic fungal species. Since mycotoxins may be resistant to the roasting process, this suggests possible exposure to mycotoxins through consumption of coffee. Further studies need to be conducted to provide information on critical points of coffee processing, such that fungal contamination may be reduced or eliminated and thus exposure to fungi and mycotoxins through coffee handling and consumption be prevented.
- Fungi distribution in poultry feedPublication . Viegas, Carla; Pacífico, Cátia; Faria, Tiago; Oliveira, Ana Cebola; Gomes, Anita Quintal; Viegas, SusanaFeed can easily be contaminated and colonized by fungi that use up the nutrients for their own metabolism and growth, producing secondary metabolites such as mycotoxins that are not eliminated throughout the feed processing. The major problems associated with mycotoxin contaminated animal feed are metabolic disturbances resulting in poor animal productivity. In addition, handling contaminated animal feed can also raise health issues regarding workers exposure to fungi and mycotoxins. The scope of this work was to characterize fungal distribution in 11 poultry feed samples. Twenty grams of feed were suspended in 180 mL of distilled water and homogenized during 20 minutes at 200 rpm. The washed supernatant was plated in malt extract agar (MEA) and dichloran glycerol agar base (DG18) media for morphological identification of the mycobiota present. Using macro- and microscopic analysis of the colonies, fungal contamination was evident in 72.7% of the analyzed poultry feed samples. Fungal load ranged from 0 to 13140 CFU/g, and the most prevalent species/genera were F. graminearum complex (71.1%), Penicillium sp. (11.6%), Cladosporium sp. (8.8%), and Fusarium poae (3.6%). In addition to these species, we also isolated Aspergillus sections Circumdati, Nigri and Aspergilli, and Mucor and Rhizopus genus albeit at a lower abundance. The data obtained showed that, besides high fungal contamination, mycotoxins contamination is probably a reality, particularly in the final product since mycotoxins resist to all the processing operations including thermal treatment. Additionally, data claimed attention for the probable co-exposure to fungi and mycotoxins of the workers in feed industries.
- Hospital surfaces contamination with antineoplastic drugs: influence of cleaning proceduresPublication . Oliveira, Ana Cebola; Pádua, Mário; Viegas, SusanaIntroduction: The raising frequency of cancer diseases is leading to a widespread application of antineoplastic drugs, thus increasing the probability of workplace surfaces contamination. Most of these drugs are classified by the International Agency for Research on Cancer as known or suspected human carcinogens. Skin absorption is the main route for antineoplastic drugs exposure in occupational settings, therefore cleaning protocols have paramount influence in surfaces contamination and, consequently, in exposure. The aim of this study was to assess surfaces contamination in a Portuguese chemotherapy unit before and during drug administration, in both preparation and administration facilities. Methods: Samples were collected by wipe-sampling from potentially contaminated surfaces selected by previous protocol observation. Samples were analyzed by HPLCDAD. Cyclophosphamide (CP), 5-fluorouracil (5FU), and paclitaxel (PTX) were used as surrogate markers for surfaces contamination for all cytotoxic drugs. Results: From the 34 samples collected before any preparation and administration activities, 41.2% were contaminated with 5-FU (4.0-84.7 ng/cm2) and 23.5% of the samples were contaminated with CP (19.8-139.6 μg/cm2). Only 2 samples presented contamination by PTX (5.9%) with a maximum value of 3.7 ng/cm2. Of the 37 samples collected during preparation and administration of antineoplastic drugs, 48.7% were contaminated with 5-FU (1.9-88.7 ng/cm2) and 24.3% with CP (12.0-93.9 μg/cm2). None of the samples showed contamination with PTX. Discussion: Data showed differences in contamination levels before and after the handling of antineoplastic drugs in preparation and in administration settings. These results point out the importance of cleaning procedures. This is well in accordance to previous studies that showed how the type of cleaning procedures and products used can be determinant for surfaces decontamination.
- Sterigmatocystin in foodstuffs: higher concern due to climate changesPublication . Viegas, Susana; Oliveira, Ana Cebola; Nurme, Janne; Viegas, CarlaThe Food and Agriculture Organization of the United Nations (FAO) estimated that approximately 25% of the cereals produced in the world are contaminated with mycotoxins. There are many factors involved in mycotoxins production by fungi but the climate is the most important. The climate of some countries will probably become warmer reaching temperatures of 33 ºC, which is, for instance, a temperature very close to the optimal for several mycotoxins production. This is the case of sterigmatocystin (STC), produced mainly by Aspergillus versicolor. Although its toxicity is lower than AFB1, STC is classified as being carcinogenic classified by IARC as group 2B, with immunomodulatory activity, mutagenicity in mammalian cells after metabolic activation, inhibition of the cell cycle and mitosis, and an increase in the formation of reactive oxygen species and lipid peroxidation in vivo. This review intended to collect information present in scientific papers about STC presence in foodstuffs and an exhaustive search was made for papers from January 2010 available on online scientific databases. Papers reported the occurrence of STC in basic daily foods at low levels such as wheat, rye, corn, barley and by-products, bread, soy, groundnuts, rice, cocoa beans, vegetables and pistachio, and at high levels in red pepper, caraway, cumin (18-23 μg.kg-1) and coffee beans (12 000 μg.kg-1). Although in most of the foods the levels found are low, there is still a concern since it can lead to a chronic exposure that, in some countries, can result in higher exposure to the presence in several foodstuffs. So, further studies are needed in order to assess exposure considering different diet regimes. Additionally, research projects should be dedicated to understanding if the contamination by STC in different crops and products is expected to increase due to climate change. This will allow recognizing the most suitable measures to avoid contamination and prevent consumers exposure.
- Task-based approach used on surfaces sampling strategy definition: the case of antineoplastic occupational exposurePublication . Viegas, Susana; Oliveira, Ana Cebola; Pádua, MárioTask-based approach implicates identifying all the tasks developed in each workplace aiming to refine the exposure characterization. The starting point of this approach is the recognition that only through a more detailed and comprehensive understanding of tasks is possible to understand, in more detail, the exposure scenario. In addition allows also the most suitable risk management measures identification. This approach can be also used when there is a need of identifying the workplace surfaces for sampling chemicals that have the dermal exposure route as the most important. In this case is possible to identify, through detail observation of tasks performance, the surfaces that involves higher contact (frequency) by the workers and can be contaminated. Identify the surfaces to sample when performing occupational exposure assessment to antineoplasic agents. Surfaces selection done based on the task-based approach.
- Toxigenic fungi in coffee samples: a menace to public healthPublication . Viegas, Carla; Pacífico, Cátia; Oliveira, Ana Cebola; Gomes, Anita Quintal; Viegas, SusanaIntroduction - Mycotoxin contamination was reported to occur in some food and commodities, such as coffee, particularly due to the presence of toxigenic fungi such as Aspergillus, Penicillium and Fusarium spp. Aspergilli are known to produce high levels of mycotoxins, such as ochratoxin and aflatoxin. Aspergillus ochraceus has been proposed as the major cause of ochratoxin A contamination in coffee beans. Aim of the study - The aim of this work was to evaluate the prevalence of Aspergillus sections Circumdati, Flavi and Fumigati in 28 green coffee samples to be used by Portuguese coffee industry, from Coffea arabica (Arabica coffee) and Coffea canephora (Robusta coffee) species from different origins.
- Unacylated ghrelin does not seem to influence glucose homeostasis in obese womenPublication . Silva-Nunes, José; Brito, Miguel; Silva, Carina; Oliveira, Ana Cebola; Veiga, LuísaBackground and Aim: Unacylated ghrelin (UAG) is the major form of circulating ghrelin. Initially considered as a non-functional peptide, soon after UAG has been associated with a negative action on energy balance, suppression of hepatic glucose production and a decrease in circulating levels of insulin. The aim of this study was to analyze the association between the serum levels of UAG and glucose metabolism parameters in obese women, independently from the eventual interference of adiposity. Material and Methods: One hundred lean and 254 obese Caucasian women were studied. Each woman was characterized for total body weight, body mass index (BMI), waist and hip circumferences, glucose at fasting and 2 hours after an oral glucose tolerance test (OGTT), fasting insulin, glycated hemoglobin (HbA1c), and UAG. Insulin resistance was assessed by the homeostasis model assessment (HOMA-IR). Obese women were classified into three glycemic status subgroups (normoglycemia, prediabetes, and diabetes) according to HbA1c and glucose values. Results: When compared with the lean group, significantly lower UAG levels were observed in obese women when compared with the lean group (350.2±251.9 vs 219.2±149.7 pg/ml; P<0.001). However, no significant difference was observed through obesity classes I to III. UAG levels were not significantly different among glycemic status subgroups and did not show any direct association with glucose, insulin, HOMA-IR, or HbA1c values. Conclusions: Although the level of the unacylated form of ghrelin shows an association with anthropometrics it seems not to be involved in glucose homeostasis.