Porphyridium purpureum microalga physiological and ultrastructural changes under copper intoxication.

The present work assessed the effect of copper (Cu) on cell dynamics and structure of the microalga Porphyridium purpureum (Rhodophyta, Bangiophycidae). Ultrastructure of the microalga was investigated and fluorescence of chlorophyll a and phycoerythrin, and content of reactive oxygen species (ROS) were estimated by flow cytometry. The number of cells did not show statistically significant differences at concentrations of 50 and 100 µg/L of Cu compared to the control, whereas 150 µg/L of Cu inhibited population growth. The fluorescence of chlorophyll a increased following exposure to Cu 100 µg/L and fluorescence of phycoerythrin enhanced by Cu 150 µg/L. There was no alteration in the above indicators at other concentrations. The content of ROS increased with increasing Cu concentration in a dose-dependent manner. The population size structure was also changed by Cu as the number of cells sized 4-6 µm was increased in the presence of Cu, especially with Cu 150 µg/L. Changes in the topography of thylakoids grew larger with Cu concentration.

Assessing microbiological quality of ready-to-eat prepacked sandwiches, in Crete, Greece.

The microbiological quality of pre-packed sandwiches, prepared by a company which had implemented the Hazard Analysis Critical Control Points system, was assessed at retail level, in Crete, Greece. Totally, we analyzed 225 sandwiches (S1: ham, cheese; S2: ham, cheese, tomato; S3: tuna salad), for specific pathogens (Listeria monogytenes, Salmonella spp, Staphylococcus aureus) and hygiene indicators (Escherichia coli, Enterobacteriaceae, Aerobic Colony Count-ACC). Pathogens were not detected. The E. coli numbers enumerated in day 0 (factory level) were found within acceptable levels < 100 cfu/g; limited samples had unsatisfactory values at the 3rd day of retailing storage (7%, 7%, and 27% > 100 cfu/g for S1, S2, and S3, respectively), which were further increased at the 7th day (20%, 33% and 53% > 100 cfu/g for S1, S2, and S3, respectively). The Enterobacteriaceae numbers mean log CFU/g were in the satisfactory or acceptable category with an increase in the range of 19.5-49.5% at the 7th day, nevertheless never exceeded the borderline of 4 log CFU/g. All ACC values were satisfactory or acceptable as no value higher than 7 log CFU/g was recorded. Overall there was a difference between the three sandwiches types, with S2 and S3, exhibiting higher levels than S1, possibly due to the extra ingredients. A number of corrective actions can be applied, as i.e. revision of cooking-chilling times, sanitizing procedures, staff hygiene practices and training etc.

Carcinogenic, ethanol, acetaldehyde and noncarcinogenic higher alcohols, esters, and methanol compounds found in traditional alcoholic beverages. A risk assessment approach.

Greek fermentation and distillation industries produce traditional spirit beverages, such as tsipouro and tsikoudia, consumed both in bottles and bulk quantities by the general population or tourists. The same spirits are also produced by individuals at home since previous centuries, as a part of the local culture but mainly due to the Greek agricultural sector unique characteristics (small cultivation areas with great number of farmers). In this study, the concentrations of carcinogenic compounds: ethanol and acetaldehyde; and noncarcinogenic: higher alcohols (1-propanol, isobutanol, and isoamyl alcohol), esters (ethyl acetate), and methanol were measured to estimate the potential cancer risk and daily intake of these compounds. The margin of exposure (MOE) of carcinogenic compounds was found to be less than 500 (mean value), well below the toxic threshold of 10,000, above which there is not public concern, as suggested by the European Food Safety Authority. Additionally, through risk assessment of noncarcinogenic compounds, we identified two specific compounds in-bulk spirits (produced by individuals), namely ethyl acetate and isobutanol, with health risk index (HRI) greater than 1 (indicating a possibility to induce side effects by consumption of high amounts). Our results indicate that bottled spirits, which are produced in a controlled environment (alcohol industries), showed higher human safety level in terms of both carcinogenic and noncarcinogenic risk assessment studies, comparing to bulk beverages produced by individuals (with out strict regulations).

The toxic influence and biodegradation of carbon nanofibers in freshwater invertebrates of the families Gammaridae, Ephemerellidae, and Chironomidae.

Carbon nanofibers (CNFs) are widely used in consumer products today. In this study, we assessed the effects of CNFs on the digestive system of three freshwater invertebrate species (Gammaridae, Ephemerellidae, and Chironomidae). The aquatic insects Diamesa sp., Drunella cryptomeria, and Gammarus suifunensis were incubated with the CNFs at the concentration of 100 mg/L during the 7-days period. Histological examination of the whole specimens and the longitudinal sections revealed no toxic effects of CNFs. However, a noticeable change in the structure of the CNFs accumulated in the intestines of the aquatic insects was found by Raman spectroscopy. The registered decrease in the relative proportion of amorphous carbon included in the CNF sample was found in the intestines of Diamesa sp. and D. cryptomeria. The registered effect can indicate a biodegradation of amorphous carbon in the digestive tract of these two insect species. In contrast, the decrease of highly structured carbons and the decrease of G-bonds intensity were registered in the digestive tract of G. suifunensis. This observation demonstrates the partial biodegradation of CNFs in the digestive tract of G. suifunensis.

Health risk assessment of aflatoxin M1 in infant formula milk in IR Iran.

In this study, two accurate, precise, selective and sensitive methods were developed for determining aflatoxin M1 (AFM1) in infant formula milk using immunoaffinity column clean-up followed by high performance liquid chromatography (HPLC) with fluorescence detection. The validated methods were used for determination of AFM1 in 29 samples of 6 different infant formula milk brands and the risk of AFM1 in infants aged zero to 6 months old was assessed using cancer risk, Margin of Exposure (MOE) and Hazard Index (HI). Only one sample (3.4%) was contaminated with AFM1. Although the results showed that MOE values for the mean and median exposure to AFM1 was <10,000 in infants, the additional cancer risk due to mean and median exposure to AFM1 in infant <6 months were 0.00010 and 0.00012 additional cases per year per 105 individuals, respectively, which indicates no health concern. In addition, HI values for the mean and median exposure to AFM1 for infants were quite below one which indicates no health concern. To the best of our knowledge, this is the first report on risk assessment of AFM1 in infant formula milk consumed by Iranian infants <6 months old, presenting a low risk for the evaluated groups.

Grape Stem Extracts From Three Native Greek Vine Varieties Exhibit Strong Antioxidant and Antimutagenic Properties.

BACKGROUND/AIM: The winemaking procedure results in the generation of stems, a by-product that is harmful to the environment. Concomitantly, stems are rich in polyphenols and, hence, they are putatively beneficial for human health. MATERIALS AND METHODS: In this study, the grape stem extracts derived from three native Greek vine varieties, namely Mavrodaphne, Muscat and Rhoditis were examined for their chemical composition and antioxidant and antimutagenic properties using a battery of in vitro biomarkers. RESULTS: All extracts are rich in polyphenols. Moreover, they exhibit potent antioxidant and antimutagenic properties with the extract of Mavrodaphne being the strongest in reducing the DPPH• and O2 -• radicals and the Fe3+ and in protecting plasmid DNA from peroxyl radical-induced oxidative modification. CONCLUSION: Therefore, although they are serious pollutants, grape stems contain phytochemicals with important biological properties and can be used as (ingredients of) bio-functional foods to improve certain aspects of human health.

Multiresidue analysis of insecticides and fungicides in apples from the Greek market. Applying an alternative approach for risk assessment.

Pesticides are widely used in agriculture and their proven high toxicity makes the need of monitoring their presence in food imperative. A multi residue method is applied in apples samples (81) collected from the Greek market for the monitoring of 40 analytes. Pesticides levels were evaluated by gas and liquid chromatography-mass spectrometry using a QuEChERs protocol. Risk for consumers was assessed by a newly developed methodology, employing the source related Hazard Quotient (HQs) and the adversity specific Hazard Index (HIA). The 84% of the apple's samples were positive for at least one pesticide, 21% for one pesticide, 55.6% for two to four pesticide residues and 7.4% for more than 4 pesticide residues. The most frequently detected compound was carbendazim (45.7%) followed by chlorpyrifos (44.4.0%). The mean detected concentration levels varied from 0.169 ppm (fluopyram) to 0.005 ppm (triazophos). 19 of the 40 investigated pesticides were not detected in any apple sample. For all individual pesticides, the source related Hazard Quotient (HQs) was <1 indicating no risk. HIA, resulting from the sum of all HQs was found HIA < 1 in nine out of ten toxicity groups, except to the neurotoxicity group, which presented HIA 2.258, indicating moderate risk.

Intestinal microbiota and colorectal cancer: a new aspect of research.

Colon holds a complex microbial community, which is crucial for maintaining homeostasis and regulating metabolic functions, supporting the intestinal barrier and controlling immune responses. Previous studies have supported a link between intestinal microbiota and colorectal cancer (CRC). Based on these fndings, the present review analyzed the numerous interactions that occur between microbiota and CRC, starting from the role of intestinal microbiota in colonic homoeostasis. Intestinal microbiota is a cause of CRC and involves various mechanisms such as chronic inflammation, the production of genotoxins causing DNA impairment and/or the biosynthesis of toxic compounds. Moreover, basic metabolic factors such as short-chain fatty acids (SCFAs) and bile acids are included in CRC pathogenesis. Different pathogenic pathways have been reported among different CRC regions (proximal or distal). Variations in the microbial populations are reported between the CRC from these colonic sites, possibly reflecting the bacterial dysbiosis and bioflm distribution. Bowel preparation is essential prior to colonoscopy and surgery; there is, however, minor consensus on the effects of this procedure on intestinal microbiota, notably with regard to the long-term outcomes. With regard to the therapeutic strategy in CRC, the intestinal microbiota is further involved in the modulation of the host response to chemotherapeutic agents (5-fluorouracil and irinotecan) by the interference with drug efcacy and by adverse effects and associated toxicity. In addition, the newly emerged research on CRC immunotherapy reveals an important interplay between intestinal microbiota and the immune system, which includes the possibility of targeting microbiota for the enhancement of anticancer treatment. Additional studies will further clarify the interaction between microbiota and CRC, resulting in the development of alternative therapeutic strategies by manipulating microbiota composition.

Biomonitoring of dialkylphosphate metabolites (DAPs) in urine and hair samples of sprayers and rural residents of Crete, Greece.

PURPOSE: The aim of this study was to evaluate the exposure of rural residents (control group) and occupational exposed population group of sprayers to organophosphorus pesticides (OPs) by measuring their non-specific dialkylphosphate metabolites (DAPs) in hair and in urine samples. All subjects (n=120) were residents of the municipality of Ierapetra, an area of intensive cultivation in Crete, Greece. METHODS: The determined OPs metabolites were DMP, DEP, DETP and DEDTP. Two different approaches were used for the analysis of the collected samples; solid-liquid extraction with sonication for hair and liquid-liquid extraction for urine. Gas chromatography-mass spectrometry (GC-MS) analysis was performed after derivatization of the isolated analytes. RESULTS AND DISCUSSION: The detection rates of DMP, DEP and DETP for both control and sprayers groups were high in both matrices, ranging from 91% to 100%. DEDTP was detected only in 9% of sprayers hair samples, while its detection rates in urine samples ranged from 83% to 90% for both population groups. Data analysis revealed significantly higher sumDAPs levels in urine of sprayers than in the urine of control group (p<0.001) and this is justified since sampling occurred during spraying periods. SumDAPs levels in hair samples of the sprayers were also significantly higher than in the hair of control group (p<0.001), confirming the long-term exposure to OPs. SumDAPs found levels in urine and hair samples of subjects were significantly correlated (Spearman׳s rho=0.728, p<0.001). Our study confirmed the elevated levels of DAPs in hair and urine samples in occupationally exposed group of sprayers in comparison to control group, even detected levels were similar in logarithmic scale.