A common approach for ranking of microbiological and chemical hazards in foods based on risk assessment - useful but is it possible?

This article compares and contrasts microbial and chemical risk assessment methodologies in order to evaluate the potential for a common framework for ranking of risk of chemical and microbiological hazards, and developments needed for such a framework. An overview of microbial (MRA) and chemical (CRA) risk assessment is presented and important differences are highlighted. Two microbiological and two chemical hazard-food combinations were ranked based on both a margin of exposure and a risk assessment approach. The comparisons illustrated that it is possible to rank chemical and microbiological hazard-food combinations with traditional approaches from each domain and indicated that the rank order but not the absolute measures is similar using either approach. Including severity in the assessment using DALY reduced differences between hazards and affected the outcome more than which approach was used. Ranking frameworks should include assessment of uncertainty as an integral part of the ranking, and be based on assessment of risk, not safety, and expressed in a common health metric such as disease burden. Necessary simplifications to address data gaps can involve the use of default scenarios. Challenges include comparisons of case-based vs. non-case-based health-endpoints, e.g. biomarker concentration, and integration of the severity of health effects into ranking.

Inorganic arsenic in food products on the Swedish market and a risk-based intake assessment

Inorganic arsenic (iAs) and total arsenic (tAs) were determined in common food from the Swedish market. Special focus was on rice, fish and shellfish products. For the speciation of iAs the European standard EN:16802 based on anion exchange chromatography coupled to ICP-MS was used. The two market basket food groups cereals (including rice), and sweets and condiments (a mixed group of sugar, sweets, tomato ketchup and dressings), contained the highest iAs levels (means 9 and 7 μg iAs/kg), whereas other food groups, including fish, did not exceed 2 μg iAs/kg. Varying levels of iAs were found in separate samples of tomato ketchup, 2.4-26 μg/kg, and is suggested to be one reason of the rather high average level of iAs in the food group sweets and condiments. Some specific food products revealed iAs levels much higher, i.e. rice crackers 152 and Norway lobster 89 μg iAs/kg. The intake of iAs via food was estimated by data from two national consumption surveys, performed in 2010-11 (1797 adults) and 2003 (2259 children). The estimated median iAs intakes in adults and children were 0.047 and 0.095 μg/kg body weight and day, respectively. The iAs intake for rice eaters was about 1.4 times higher than for non-rice eaters. Validation of the consumption survey-based iAs intake, using food purchase and market basket data mainly from 2015, resulted in a per capita intake of a similar magnitude, i.e. 0.056 μg/kg body weight and day. The estimated cancer risk for adults using low-dose linear extrapolation is <1 per 100,000 per year.

Risk ranking of chemical and microbiological hazards in food

Risk ranking is a versatile tool used to prioritise activities performed by public health regulatory bodies. It also allows efficient communication between all stakeholders in the process of risk analysis. However, risk ranking methods are still not optimal. Because of the different approaches employed in the risk assessment of microbiological agents and chemicals, it is difficult to rank them together using the same metrics. In our work, we first discuss differences and commonalities between chemical and microbiological risk assessment to provide a starting point for consideration of a common risk ranking platform. In the second part, we perform risk ranking of contaminants and regulated chemicals using the recently developed Risk Thermometer tool. In this approach, chemicals are not ranked solely on the basis of the margin of exposure between a reference value and the exposure, but also by considering the severity of the critical health effects used. The results show that ranking using both methods provides different results from the use of either method alone. Overall, specific chemical groups (i.e. heavy metals, pesticides, etc.) do not generally rank higher or lower, but individual compounds are scattered in the rankings from low to high. Risk ranking methods demand further development to gain wide acceptability and recognition.

A KRAS variant is a biomarker of poor outcome, platinum chemotherapy resistance and a potential target for therapy in ovarian cancer

Germ-line variants in the 3′ untranslated region (3′UTR) of cancer genes disrupting microRNA (miRNA) regulation have recently been associated with cancer risk. A variant in the 3′UTR of the KRAS oncogene, referred to as the KRAS-variant, is associated with both cancer risk and altered tumor biology. Here we test the hypothesis that the KRAS-variant can act as a biomarker of outcome in epithelial ovarian cancer (EOC), and investigate the cause of altered outcome in KRAS-variant positive EOC patients. As this variant appears to be associated with tumor biology, we additionally test the hypothesis that this variant can be directly targeted to impact cell survival.

EOC patients with complete clinical data were genotyped for the KRAS-variant and analyzed for outcome (n=536), response to neoadjuvant chemotherapy (n=125), and platinum resistance (n=306). Outcome was separately analyzed for women with known BRCA mutations (n=79). Gene expression was analyzed on a subset of tumors with available tissue. Cell lines were employed to confirm altered sensitivity to chemotherapy with the KRAS-variant. The KRAS-variant was directly targeted through siRNA/miRNA oligonucleotides in cell lines and survival was measured.

Post-menopausal EOC patients with the KRAS-variant were significantly more likely to die of ovarian cancer by multivariate analysis (HR=1.67, 95% CI=1.09–2.57, p=0.019, n=279). Possibly explaining this finding, EOC patients with the KRAS-variant were significantly more likely to be platinum resistant (OR=3.18, CI=1.31–7.72, p=0.0106, n=291). Additionally, direct targeting of the KRAS-variant led to a significant reduction in EOC cell growth and survival in vitro.

These findings confirm the importance of the KRAS-variant in EOC, and indicate that the KRAS-variant is a biomarker of poor outcome in EOC likely due to platinum resistance. In addition, this work supports the hypothesis that these tumors have continued dependence on such 3′UTR lesions, and that direct targeting may be a viable future treatment approach.

Magnetic Resonance Imaging quantification of breast density in BRCA carriers following gonadotropin releasing hormone agonist (GnRHA)-based hormonal chemoprevention

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Background: Breast tissue density limits the usefulness of mammography as a surveillance tool in young women. Breast Magnetic Resonance Imaging (MRI) provides high tissue contrast and three-dimensional structural information not impaired by high breast density. We developed a volumetric “MR density” measure of breast structural composition that may be complementary to mammographic breast density. We tested this MR density measure in unaffected women with known high risk of breast cancer due to a BRCA gene mutation (or empiric risk > 30% lifetime), who were recruited in a phase II trial to study the effects of a hormonal chemoprevention regimen. Methods: Nine premenopausal high-risk women age 21 to 48 were treated with intranasal GnRHA (deslorelin), low-dose estradiol, and testosterone daily for 10 months. All patients underwent one contrast-enhanced breast MRI exam before and after treatment. We measured MR density as the ratio of fibroglandular tissue volume to total volume of the breast, at both time points. Our technique involved the semi-automated delineation of the breast and the automated segmentation of fibroglandular from adipose tissue. An “MR index” was also defined to quantify partial voluming effects due to the presence of adipose/fibroglandular edges in the MR data. Results: Eight out of nine patients showed a reduction in MR density (p = 0.026) with treatment. Three patients had less than 5% MR density at baseline, making it difficult to quantitate a change with treatment. All of the remaining six patients had reduced MR density after treatment (mean reduction 35.5%; p = 0.035). Conclusions: We have demonstrated the use of breast MR density as a robust volumetric quantitative measure of breast tissue composition. Our findings suggest that MR could be used to measure hormonal chemoprevention effects in BRCA carriers.

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Delivering mental health care to HIV-positive individuals. A comparison of two models

Data on initial psychiatric evaluations performed in 1995 were compared to assess whether psychiatric consultation for human immunodeficiency virus (HIV)-positive/acquired immunodeficiency syndrome (AIDS) patients provided on-site in an infectious disease (ID) clinic improved compliance and were preferred by staff to evaluations performed in a specialized AIDS psychiatric program. Compliance with initial appointments remained below 50% in both settings, but more patients seen in the ID clinic had received prior psychiatric treatment and medication and they were more likely to receive a psychotropic prescription at this initial visit. The ID clinic staff preferred on-site consultations. Stationing psychiatric consultants in the ID clinic may reach a more impaired population but did not improve compliance with the initial visit.