Toxin immunosensors and sensor arrays for food quality control

The global efforts to improve consumer protection and public health lead to an increasing number of analytical approaches applicable to food analysis and process control. Biosensor systems are efficient analytical tools to monitor production processes or storage of nutrition and to control contamination outbreaks as they are easy-to-use, fast, and with minimal effort on sample preparation. Relevant targets of immunosensors implemented to food safety are prevalent bacterial toxins (staphylococcal enterotoxins and clostridial toxins), plant toxins (Ricin), mycotoxins (aflatoxins and ochratoxin A), marine toxins, and other pathogenic bacterial contaminations (Listeria, Salmonella, Staphylococcus aureus, or Escherichia coli). These cause acute intoxication and also chronic diseases in humans consuming contaminated food. Promising approaches for the determination of different types of toxins in food matrices will be outlined. The corresponding sensor systems use immunological receptor units such as antibodies or antigens and include optical (fluorescence and surface plasmon resonance), electrochemical, or acoustical readout methods. This review is focused on recent developments of sensor formats devoted to food safety control and is structured according to the type of toxin or contaminant that is recognized. It is intended to give an overview on emerging sensor technologies and their potential applications for the rapid analysis of the most important food poisoning agents.     

On the morality of vaccination tourism

Vaccination tourism (whereby citizens of one nation travel to a different, usually more developed nation to receive a vaccine unavailable or with little availability at home) during the COVID pandemic raises a host of moral issues and is usually met with criticism. From the perspective of the society of origin, the criticism is that those who use their socio-economic privileges to go abroad and receive the vaccine ahead of other citizens instead of ‘making the line’ act objectionably because in doing so they use their purchasing power to obtain a benefit that should not be distributed like any other product in the market. From the perspective of the society of destination, the criticism is that citizens and residents should receive the vaccines first; after all, their government purchased vaccines (with their taxes) to immunize the local population. The paper calls into question both objections to vaccination tourism. There might be other reasons to oppose it, but this pair of objections cannot ground a moral criticism of the practice.     

First record of Alucita danunciae (Lepidoptera: Alucitidae) in Peru

ABSTRACT

The little-known Alucita danunciae Vargas, 2011 (Lepidoptera: Alucitidae) is recorded for the first time from Peru, expanding its altitudinal, geographic and host plant ranges. Its larvae were found on fruits of Tecoma fulva arequipensis (Bignoniaceae) at 2900 m elevation in Pocsi, Arequipa, on the western slopes of the Andes of southern Peru. Genetic divergence between the Chilean (type locality) and Peruvian DNA barcode haplotypes was 0.6–0.9% K2P.     

Induction of cytochrome P-450-dependent drug metabolism by juvenile hormone mimics in mammalian cell culture

The monooxygenase activity of fetal hepatocytes in culture shows a differential response toward juvenile hormone I and analogs. Juvenile hormone I, R-20458, and Methoprene increase the deethyiation of 7-ethoxyresorufin while not affecting or even inhibiting the N-demethylation of p-chloro-N-methylaniline. RO-203600, a 1,3-benzodioxole-containing analog, increases both the deethylase and the N-demethylase, whereas Hydroprene does not affect either activity. The inductive effect with juvenile hormone I is obtained with exposure periods of at least 30 min and is maximum when the concentration of the hormone is 14 μM in the medium. This amount results in the covalent binding to cellular macromolecules of 1.3 × 19^?18 moles/cell. The induction requires continuous protein synthesis but RNA synthesis only for a short initial period. It is concluded that juvenile hormone and mimics induce specific cytochrome P-450 species in fetal liver cells even if the culture conditions are not optimal. The toxicological implications of these results are briefly discussed.