pH-sensitive resist materials for combined photolithographic patterning of proteins and fluid lipid bilayers

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2008.Includes bibliographical references (p. 33-34).Photolithography of a pH-sensitive photoresist polymer was performed to pattern both lipid bilayers and proteins onto the same surface. The motivation behind this was to create a substrate mimicking an array of antigen- presenting cells. The substrate would consist of signaling ligand, biotin anti- CD3, bound to a lipid bilayer in a regular array of patches. The fluidity of the lipid bilayer would impart mobility to the signaling ligand. It was found that under appropriate substrate fabrication conditions, lipid bilayers and their associated ligand do segregate to the desired signaling patches. Additionally, the bilayer in these regions is fluid, and is potentially bioactive. This bodes well for our system as a future platform to study the actions of the helper T cell and antigen- presenting cell at the immunological synapse.by Mirat Shah.S.B

Follow-up of the re-evaluation of polyglycerol esters of fatty acids (E 475) as a food additive

Polyglycerol esters of fatty acids (PEFA, E 475) was re-evaluated in 2017 by the former EFSA Panel on Food Additives and Nutrient sources added to Food (ANS). As a follow-up to this assessment, in this opinion, the Panel on Food Additives and Flavouring (FAF) addresses the data gaps identified to support an amendment of the EU specifications for E 475. The Panel performed a risk assessment of undesirable impurities and constituents potentially present in E 475. The Panel concluded that the maximum limits in the EU specifications for the 4 toxic elements (arsenic, lead, mercury and cadmium) should be lowered based on actual levels in the commercial food additive E 475. The Panel also concluded that maximum limits for erucic acid, 3-monochloropropanediol and glycidyl esters should be included in the EU specifications for E 475. Alternatively, the Panel recommends an amendment of the definition of E 475 to include a requirement that the fats and oils used in the manufacturing of E 475 comply with the respective EU legislation regarding suitability for human consumption. Further, the Panel concluded that there is no need for setting a specification limit for the content of trans-fatty acids in E 475 as a limit is established in the Regulation (EU) No 2019/649, i.e. 2 g of trans-fat per 100 g fat in food for the final consumer. Finally, the Panel recommends a modification of the definition of E 475 indicating that polyglycerol used for the manufacturing of E 475 should be produced from glycerol meeting the specifications for E 422 (Commission Regulation (EU) No 231/2012). In this case, respective specification limits for epichlorohydrin, acrolein and butanetriol would not be needed for E 475

Follow-up of the re-evaluation of glycerol (E 422) as a food additive

Glycerol (E 422) was re-evaluated in 2017 by the former EFSA Panel on Food Additives and Nutrient sources added to Food (ANS). As a follow-up to that assessment, in this opinion, the Panel on Food Additives and Flavourings (FAF) addresses the data gaps identified to support an amendment of the EU specifications for E 422 in Commission Regulation (EU) No 231/2012. The Panel performed a risk assessment of undesirable impurities present in E 422. The Panel concluded that the maximum limits in the EU specifications for the four toxic elements (arsenic, lead, mercury and cadmium) should be lowered based on actual levels in the commercial food additive E 422. The Panel recommended setting a numerical limit value for acrolein in the specifications for E 422. The potential exposure to free 3-monochloropropanediol at the maximum limit of 0.1 mg/kg, as laid out in the specifications for E 422, does not give rise to a health concern. The Panel recommended to consider modifying the definition of E 422 in Commission Regulation (EU) No 231/2012 indicating that E 422 is obtained only from vegetable oils and fats and undergoes purification processes that involve distillation, and other clean up steps to obtain refined glycerol. Overall, the Panel concluded that the technical data provided support an amendment of the specifications for glycerol (E 422)

Follow-up of the re-evaluation of polyglycerol polyricinoleate (E 476) as a food additive

Polyglycerol polyricinoleate (PGPR, E 476) was re-evaluated in 2017 by the former EFSA Panel on Food Additives and Nutrient sources added to Food (ANS). As a follow-up to this assessment, in this opinion, the Panel on Food Additives and Flavouring (FAF) addresses the data gaps identified to support an amendment of the EU specifications for E 476. Additionally, this opinion deals with the assessment of the proposed extension of use for E 476 in edible ices and a revision of the maximum permitted level in emulsified sauces. The Panel concluded that the proposed extension of use, if authorised, would not give rise to a safety concern. Additionally, the Panel performed a risk assessment of undesirable impurities potentially present in E 476. The Panel concluded that the maximum limits in the EU specifications for the four toxic elements (arsenic, lead, mercury, cadmium) should be lowered based on actual levels in the commercial food additive E 476. The Panel also concluded that maximum limits for glycidyl esters and 3-monochloropropanediol should be included in the EU specifications for E 476. Alternatively, the Panel recommends an amendment of the definition of E 476 to include a requirement that the fats and oils used in the manufacturing of E 476 comply with the respective EU legislation regarding suitability for human consumption. Further, the Panel recommends a modification of the definition of E 476 indicating that polyglycerol used for the manufacturing of E 476 should be produced from glycerol meeting the specifications for E 422 (Commission Regulation (EU) No 231/2012). In this case, respective specification limits for epichlorohydrin, acrolein and butanetriol would not be needed for E 476. Finally, the Panel concluded that the proposed method based on the determination of ricinoleic acid is suitable for the determination of E 476 content in food

Economic Value of Dengue Vaccine in Thailand

With several candidate dengue vaccines under development, this is an important time to help stakeholders (e.g., policy makers, scientists, clinicians, and manufacturers) better understand the potential economic value (cost-effectiveness) of a dengue vaccine, especially while vaccine characteristics and strategies might be readily altered. We developed a decision analytic Markov simulation model to evaluate the potential health and economic value of administering a dengue vaccine to an individual (≤ 1 year of age) in Thailand from the societal perspective. Sensitivity analyses evaluated the effects of ranging various vaccine (e.g., cost, efficacy, side effect), epidemiological (dengue risk), and disease (treatment-seeking behavior) characteristics. A ≥ 50% efficacious vaccine was highly cost-effective [< 1× per capita gross domestic product (GDP) ($4,289)] up to a total vaccination cost of$60 and cost-effective [< 3× per capita GDP ($12,868)] up to a total vaccination cost of$200. When the total vaccine series was $1.50, many scenarios were cost saving

Follow-up of the re-evaluation of sulfur dioxide (E 220), sodium sulfite (E 221), sodium bisulfite (E 222), sodium metabisulfite (E 223), potassium metabisulfite (E 224), calcium sulfite (E 226), calcium bisulfite (E 227) and potassium bisulfite (E 228)

Sulfur dioxide-sulfites (E 220-228) were re-evaluated in 2016, resulting in the setting of a temporary ADI of 0.7 mg SO2 equivalents/kg bw per day. Following a European Commission call for data, the present follow-up opinion assesses data provided by interested business operators (IBOs) and additional evidence identified in the publicly available literature. No new biological or toxicological data addressing the data gaps described in the re-evaluation were submitted by IBOs. Taking into account data identified from the literature search, the Panel concluded that there was no substantial reduction in the uncertainties previously identified in the re-evaluation. Therefore, the Panel considered that the available toxicity database was inadequate to derive an ADI and withdrew the current temporary group acceptable daily intake (ADI). A margin of exposure (MOE) approach was considered appropriate to assess the risk for these food additives. A lower confidence limit of the benchmark dose of 38 mg SO2 equivalents/kg bw per day, which is lower than the previous reference point of 70 mg SO2 equivalents/kg bw per day, was estimated based on prolonged visual evoked potential latency. An assessment factor of 80 was applied for the assessment of the MoE. At the estimated dietary exposures, when using a refined exposure scenario (Data set D), MOEs at the maximum of 95th percentile ranges were below 80 for all population groups except for adolescents. The dietary exposures estimated using the maximum permitted levels would result in MOEs below 80 in all population groups at the maximum of the ranges of the mean, and for most of the population groups at both minimum and maximum of the ranges at the 95th percentile. The Panel concluded that this raises a safety concern for both dietary exposure scenarios. The Panel also performed a risk assessment for toxic elements present in sulfur dioxide-sulfites (E 220-228), based on data submitted by IBOs, and concluded that the maximum limits in the EU specifications for arsenic, lead and mercury should be lowered and a maximum limit for cadmium should be introduced

IMPACT OF VOLATILE ORGANIC COMPOUNDS ON CHROMIUM CONTAINING ATMOSPHERIC PARTICULATE: INSIGHTS FROM MOLECULAR DYNAMICS SIMULATIONS

The effect of volatile organic compounds (VOCs) on chromium-containing atmospheric particles remains obscured because of difficulties in experimental measurements. Moreover, several ambiguities exist in the literature related to accurate measurements of atmospheric chromium concentration to evaluate its toxicity. We investigated the interaction energies and diffusivity for several VOCs in chromium (III)-containing atmospheric particles using classical molecular dynamics simulations. We analyzed xylene, toluene, ascorbic acid, carbon tetrachloride, styrene, methyl ethyl ketone, naphthalene, and anthracene in Cr(III) solutions, with and without air, to compare their effects on solution chemistry. The interaction energy between Cr(III) and water changed from 48 to 180% for different VOCs, with the highest change with anthracene and the lowest change with naphthalene. The results revealed no direct interactions between Cr(III) particles and the analyzed volatile organic compounds, except ascorbic acid. Interactions of Cr(III) and ascorbic acid differ significantly between the solution phase and the particulate phase. The diffusion of Cr(III) and all the VOCs also were observed in a similar order of magnitude (~ 10−5 cm2/s). The results can further assist in exploring the variation in chromium chemistry and reaction rates in the atmospheric particles in the presence of VOCs

Results of the Croatian primary percutaneous coronary intervention network for patients with ST-segment elevation acute myocardial infarction

The Republic of Croatia, with a gross domestic product per capita of US$11,554 in 2008, is an economically less-developed Western country. The goal of the present investigation was to prove that a well-organized primary percutaneous coronary intervention network in an economically less-developed country equalizes the prospects of all patients with acute ST-segment elevation myocardial infarction at a level comparable to that of more economically developed countries. We prospectively investigated 1,190 patients with acute ST-segment elevation myocardial infarction treated with primary PCI in 8 centers across Croatia (677 nontransferred and 513 transferred). The postprocedural Thrombolysis In Myocardial Infarction flow, in-hospital mortality, and incidence of major adverse cardiovascular events (ie, mortality, pectoral angina, restenosis, reinfarction, coronary artery bypass graft, and cerebrovascular accident rate) during 6 months of follow-up were compared between the nontransferred and transferred subgroups and in the subgroups of older patients, women, and those with cardiogenic shock. In all investigated patients, the average door-to-balloon time was 108 minutes, and the total ischemic time was 265 minutes. Postprocedural Thrombolysis In Myocardial Infarction 3 flow was established in 87.1% of the patients, and the in-hospital mortality rate was 4.4%. No statistically significant difference was found in the results of treatment between the transferred and nontransferred patients overall or in the subgroups of patients >75 years, women, and those with cardiogenic shock. In conclusion, the Croatian Primary Percutaneous Coronary Intervention Network has ensured treatment results of acute ST-segment elevation myocardial infarction comparable to those of randomized studies and registries of more economically developed countries