Poly(HEMA) brushes emerging as a new platform for direct detection of food pathogen in milk samples

Surface plasmon resonance (SPR) biosensors capable of in real time detection of Cronobacter at concentrations down to 10? cells mL?1 in samples of consumer fresh-whole fat milk, powder whole-fat milk preparation, and powder infant formulation were developed for the first time. Antibodies against Cronobacter were covalently attached onto polymer brushes of poly(2-hydroxyethyl methacrylate) (poly(HEMA)) grafted from the SPR chip surface. The lowest detection limit, 10? cells mL?1, was achieved in phosphate buffered saline (pH 7.4) with sensors prepared by covalent immobilization of the same antibodies onto a self assembled monolayer (SAM) of hexa(ethylene glycol) undecanethiol (EG?). However, when the EG? based sensors were challenged with milk samples the non-specific response due to the deposition of non-targeted compounds from the milk samples was much higher than the specific response to Cronobacter hampering the detection in milk. Similar interfering fouling was observed on antifouling polymer brushes of hydroxy-capped oligoethylene glycol methacrylate and even a 10 times higher fouling was observed on the widely used SAM of mixed hydroxy- and carboxy-terminated alkanethiols. Only poly(HEMA) brushes totally suppressed the fouling from milk samples. The robust well-controlled surface initiated atom transfer radical polymerization of HEMA allowed the preparation of highly dense brushes with a minimal thickness so that the capture of antigens by the antibodies immobilized on the brush layer could take place close to the gold SPR surface to provide a stronger optical response while the fouling was still suppressed. A minimum thickness of 19 nm of poly(HEMA) brush layer was necessary to suppress completely non-specific sensor response to fouling from milk.     

Differentiation-Dependent Effects of a New Recombinant Manganese Superoxide Dismutase on Human SK-N-BE Neuron-Like Cells

Neurochemical Research - We have recently isolated a new isoform of recombinant manganese superoxide dismutase (rMnSOD) which provides a potent antitumor activity and strongly counteracts the...     

Female choice for sick males over healthy males: Consequences for offspring

Sexual selection theory indicates that ornament expression in males is in close relation to their condition. This “honesty” relationship serves as the basis for female choice: Females would mate with healthy males over sick males after assessing male ornament signal expression and derive benefits for their progeny. Here, we investigated female mate choice for infected and non‐infected males, male survival after infection (to corroborate the negative effect of infection), and fitness consequences of female preferences using Tenebrio molitor beetles. Male infection was produced having two types of challenges as follows: males infected with entomopathogenic fungi and males infected with nylon implants. Similar to previous studies, we corroborated that females preferred fungus‐infected males over positive control, negative control, and nylon‐challenged males. Survival was the lowest for fungus‐treated males followed by nylon‐treated and control males. Females mated with fungus‐treated males laid fewer and smaller eggs, and the laid eggs had less lipid content with a reduced eclosion success compared to females mated with non‐challenged males. Our interpretation is that fungus‐treated males invested their energetic resources to increase their attractiveness at the risk of survival, in a terminal investment fashion. Females, however, would have corrected their choice by investing less in their offspring.     

Magnetic Resonance Examinations of Patients With Implanted Active Devices. A Low‐Cost Approach in Slew Rate Evaluation

Time‐varying magnetic field gradients involved in magnetic resonance examinations can damage implanted electronic systems. The quantity related to this side effect is the gradient slew rate, which is usually not directly available on magnetic resonance console. The present study proposes a low‐cost approach in slew rate assessment, which is useful in risks versus benefits evaluation as well as in sequences optimization. The experimental method is based on an analog circuit, which senses the output voltage of the scanner waveform generator. This allows taking easy and reliable slew rate measurements, even during clinical examinations on patients. Whereas previous studies required managing a considerable amount of data, the present work addresses only the maximal slew rate of any clinical sequence. Experimental results show that the smooth gradient mode, selectable on the two scanners examined, is very effective in patient safety improvement. In particular, it reduces slew rate values in the range from 52.4 up to 132.4 T m^‐1 s^‐1, i.e. far below the interval 216–346 T m^‐1 s^‐1, indicated as slew rate tolerance limit of modern implanted electronic devices. Bioelectromagnetics. 2019;40:512–521. © 2019 Bioelectromagnetics Society     

Phylogenetic incongruence inferred with two mitochondrial genes in Mepraia spp. and Triatoma eratyrusiformis(Hemiptera,Reduviidae)

Mitochondrial DNA (mtDNA) is widely used to clarify phylogenetic relationships among and within species, and to determine population structure. Due to the linked nature of mtDNA genes it is expected that different genes will show similar results. Phylogenetic incongruence using mtDNA genes may result from processes such as heteroplasmy, nuclear integration of mitochondrial genes, polymerase errors, contamination, and recombination. In this study we used sequences from two mitochondrial genes (cytochrome b and cytochrome oxidase subunit I) from the wild vectors of Chagas disease, Triatoma eratyrusiformis and Mepraia species to test for topological congruence. The results showed some cases of phylogenetic incongruence due to misplacement of four haplotypes of four individuals. We discuss the possible causes of such incongruence and suggest that the explanation is an intra-individual variation likely due to heteroplasmy. This phenomenon is an independent evidence of common ancestry between these taxa.     

The Economic Crisis and Acute Myocardial Infarction: New Evidence Using Hospital-Level Data

Objective

This research sought to assess whether and to what extent the ongoing economic crisis in Italy impacted hospitalizations, in-hospital mortality and expenditures associated with acute myocardial infarction (AMI).

Methods

The data were obtained from the hospital discharge database of the Italian Health Ministry and aggregated at the hospital level. Each hospital (n = 549) was observed for 4 years and was geographically located within a “Sistema Locale del Lavoro” (SLL, i.e., clusters of neighboring towns with a common economic structure). For each SLL, the intensity of the crisis was determined, defined as the 2012–2008 increase in the area-specific unemployment rate. A difference-in-differences (DiD) approach was employed to compare the increases in AMI-related outcomes across different quintiles of crisis intensity.

Results

Hospitals located in areas with the highest intensity of crisis (in the fifth quintile) had an increase of approximately 30 AMI cases annually (approximately 13%) compared with hospitals in area with lower crisis intensities (p<0.001). A significant increase in total hospital days was observed (13%, p<0.001) in addition to in-hospital mortality (17%, p<0.001). As a consequence, an increase of around €350.000 was incurred in annual hospital expenditures for AMI (approximately 36%, p<0.001).

Conclusions

More attention should be given to the increase in health needs associated with the financial crisis. Policies aimed to contrast unemployment in the community by keeping and reintegrating workers in jobs could also have positive impacts on adverse health outcomes, especially in areas of high crisis intensity.     

Canine Antibodies against Salivary Recombinant Proteins of Phlebotomus perniciosus: A Longitudinal Study in an Endemic Focus of Canine Leishmaniasis

BackgroundPhlebotomine sand flies are vectors of Leishmania parasites. During blood feeding, sand flies deposit into the host skin immunogenic salivary proteins which elicit specific antibody responses. These anti-saliva antibodies enable an estimate of the host exposure to sand flies and, in leishmaniasis endemic areas, also the risk for Leishmania infections. However, the use of whole salivary gland homogenates as antigen has several limitations, and therefore, recombinant salivary proteins have been tested to replace them in antibody detection assays. In this study, we have used for the first time sand fly salivary recombinant proteins in a longitudinal field study on dogs.ConclusionsThese results suggest that P. perniciosus rSP03B protein is a valid alternative to whole saliva and could be used in large-scale serological studies. This novel method could be a practical and economically-sound tool to detect the host exposure to sand fly bites in CanL endemic areas.     

Suppression of a Field Population of Aedes aegypti in Brazil by Sustained Release of Transgenic Male Mosquitoes

The increasing burden of dengue, and the relative failure of traditional vector control programs highlight the need to develop new control methods. SIT using self-limiting genetic technology is one such promising method. A self-limiting strain of Aedes aegypti, OX513A, has already reached the stage of field evaluation. Sustained releases of OX513A Ae. aegypti males led to 80% suppression of a target wild Ae. aegypti population in the Cayman Islands in 2010. Here we describe sustained series of field releases of OX513A Ae. aegypti males in a suburb of Juazeiro, Bahia, Brazil. This study spanned over a year and reduced the local Ae. aegypti population by 95% (95% CI: 92.2%-97.5%) based on adult trap data and 81% (95% CI: 74.9-85.2%) based on ovitrap indices compared to the adjacent no-release control area. The mating competitiveness of the released males (0.031; 95% CI: 0.025-0.036) was similar to that estimated in the Cayman trials (0.059; 95% CI: 0.011 – 0.210), indicating that environmental and target-strain differences had little impact on the mating success of the OX513A males. We conclude that sustained release of OX513A males may be an effective and widely useful method for suppression of the key dengue vector Ae. aegypti. The observed level of suppression would likely be sufficient to prevent dengue epidemics in the locality tested and other areas with similar or lower transmission.     

In Vitro Protective Effect and Antioxidant Mechanism of Resveratrol Induced by Dapsone Hydroxylamine in Human Cells

Dapsone (DDS) hydroxylamine metabolites cause oxidative stress- linked adverse effects in patients, such as methemoglobin formation and DNA damage. This study evaluated the ameliorating effect of the antioxidant resveratrol (RSV) on DDS hydroxylamine (DDS-NHOH) mediated toxicity in vitro using human erythrocytes and lymphocytes. The antioxidant mechanism was also studied using in-silico methods. In addition, RSV provided intracellular protection by inhibiting DNA damage in human lymphocytes induced by DDS-NHOH. However, whilst pretreatment with RSV (10–1000 μM significantly attenuated DDS-NHOH-induced methemoglobinemia, but it was not only significantly less effective than methylene blue (MET), but also post-treatment with RSV did not reverse methemoglobin formation, contrarily to that observed with MET. DDS-NHOH inhibited catalase (CAT) activity and reactive oxygen species (ROS) generation, but did not alter superoxide dismutase (SOD) activity in erythrocytes. Pretreatment with RSV did not alter these antioxidant enzymes activities in erythrocytes treated with DDS-NHOH. Theoretical calculations using density functional theory methods showed that DDS-NHOH has a pro-oxidant effect, whereas RSV and MET have antioxidant effect on ROS. The effect on methemoglobinemia reversion for MET was significantly higher than that of RSV. These data suggest that the pretreatment with resveratrol may decrease heme-iron oxidation and DNA damage through reduction of ROS generated in cells during DDS therapy.