Retinal aging in the diurnal Chilean rodent (Octodon degus): histological, ultrastructural and neurochemical alterations of the vertical information processing pathway

BACKGROUND: The retina is sensitive to age-dependent degeneration. To find suitable animal models to understand and map this process has particular importance. The degu (Octodon degus) is a diurnal rodent with dichromatic color vision. Its retinal structure is similar to that in humans in many respects, therefore, it is well suited to study retinal aging. Histological, cell type-specific and ultrastructural alterations were examined in 6, 12 and 36 months old degus. The characteristic layers of the retina were present at all ages, but slightly loosened tissue structure could be observed in 36-month-old animals both at light and electron microscopic levels. Elevated glial fibrillary acidic protein expression was observed in Müller glial cells in aging retinas. The number of rod bipolar cells and the ganglion cells was reduced in the aging specimens, while that of cone bipolar cells remained unchanged. Other age-related differences were detected at ultrastructural level: alteration of the retinal pigment epithelium and degenerated photoreceptor cells were evident. Ribbon synapses were sparse and often differed in morphology from those in the young animals. These results support our hypothesis that (i) the rod pathway seems to be more sensitive than the cone pathway to age-related cell loss; (ii) structural changes in the basement membrane of pigment epithelial cells can be one of the early signs of degenerative processes; (iii) the loss of synaptic proteins especially from those of the ribbon synapses are characteristic and (iv) the degu retina may be a suitable model for studying retinal aging

Biofilm-forming capacity in biogenic amine-producing bacteria isolated from dairy products.

Biofilms on the surface of food industry equipment are reservoirs of potentially food-contaminating bacteria - both spoilage and pathogenic. However, the capacity of biogenic amine (BA)-producers to form biofilms has remained largely unexamined. BAs are low molecular weight, biologically active compounds that in food can reach concentrations high enough to be a toxicological hazard. Fermented foods, especially some types of cheese, accumulate the highest BA concentrations of all. The present work examines the biofilm-forming capacity of 56 BA-producing strains belonging to three genera and 10 species (12 Enterococcus faecalis, 6 Enterococcus faecium, 6 Enterococcus durans, 1 Enterococcus hirae, 12 Lactococcus lactis, 7 Lactobacillus vaginalis, 2 Lactobacillus curvatus, 2 Lactobacillus brevis, 1 Lactobacillus reuteri and 7 Lactobacillus parabuchneri), all isolated from dairy products. Strains of all the tested species - except for L. vaginalis - were able to produce biofilms on polystyrene and adhered to stainless steel. However, the biomass produced in biofilms was strain-dependent. These results suggest that biofilms may provide a route via which fermented foods can become contaminated by BA-producing microorganisms

Q69, an E. faecalis-infecting bacteriophage, as a biocontrol agent for reducing tyramine in dairy products

Biogenic amines (BAs) are low molecular weight nitrogenous compounds with biological activity, formed from amino acids by decarboxylation. BAs are naturally present in all living organisms playing essential roles. However, their accumulation in food through the metabolic activity of certain microorganisms constitutes a toxicological hazard. Among foods, cheeses accumulate some of the highest concentrations of BAs since they provide an ideal environment for their accumulation. Most of the methods proposed for reducing BAs in cheese, such as milk pasteurisation, have not only failed to completely solve the problem, they also affect non-BA producing lactic acid bacteria (LAB), i.e., the bacteria that participate in the development of the organoleptic characteristics of cheese. Novel technologies specifically targeted against BA producers are therefore needed to control BA accumulation. Bacteriophages have been proposed as agents for specifically controlling the presence of foodborne pathogens in food. Due to its specificity, they could be used as a biotechnological tool targeted to reduce the population of BA-producing bacteria. The present work reports the isolation, from cheese, and the characterisation of bacteriophage Q69, which infects specifically Enterococcus faecalis, the species mainly responsible of the accumulation of the BA tyramine in foods. Furthermore, its capacity to reduce the accumulation of tyramine in different conditions –including a model cheese- was proven. The obtained results open up the possibility of use bacteriophages to prevent BA accumulation in fermented foods

Room temperature and sensitive determination of haloanisoles in wine using vacuum-assisted headspace solid-phase microextraction

Summarization: Headspace solid-phase microextraction (HSSPME) is a widespread technique used to extract trace amounts of haloanisoles from wine samples. A major challenge to overcome is the high ethanol content in wines that affects the solubilities of haloanisoles and reduces their headspace abundance. To overcome this obstacle and meet sensitivity requirements, reported HSSPME procedures typically suggest heating the wine samples and/or sampling for extended times. The present work proposes the use of vacuum-assisted HSSPME (Vac-HSSPME) to accelerate the extraction kinetics whilst sampling at room temperature. Although ethanol affected the physico-chemical properties of the target analytes, these changes were not sufficient to prevent the positive effect of vacuum on HSSPME sampling. To demonstrate the benefits of adopting the vacuum approach, Vac-HSSPME and regular HSSPME methods were independently optimized and the results were compared at all times. The effect of ethanol under each pressure condition was also discussed. Under the optimum conditions found, Vac-HSSPME sampling for 30 min at room temperature at 25 °C yielded lower detection limits (0.13 to 0.19 ng L−1) than those obtained with regular HSSPME sampling for 30 min at 55 °C (0.26 to 0.76 ng L−1). The proposed Vac-HSSPME method was successfully applied to quantify haloanisoles in bottled red wines and a discussion on the effect of wine volatiles was included. The standard addition method was used to minimize matrix effects. The increase in total pressure due to the presence of ethanol and other volatile wine components did not reduce the positive effect of vacuum on HSSPME. Nonetheless, in accordance to past HSSPME methods, the limits of detection and quantification were affected due to the noise level increase and analyte interaction with matrix. The proposed Vac-HSSPME procedure was applied to twelve bottled red wines and one sample was found positive on 2,4,6-trichloronanisole.Παρουσιάστηκε στο: Journal of Chromatography

A comprehensive study on the leaching of metals from heated tobacco sticks and cigarettes in water and natural waters

Summarization: The leaching behavior of Al, Cr, Ni, Cu, Zn, As, Se, Cd, Ba, Hg and Pb in water from two types of heat-not-burn tobacco sticks is presented here, and compared to that from conventional cigarettes. The total concentration of each metal in solid tobacco products was initially determined. Concentrations in used and unused tobacco sticks were similar and generally, lower than those in unused conventional cigarettes. Studies on the contribution of paper, filter and tobacco revealed that tobacco was the major source of metal contamination. Smoking conventional cigarettes reduced the total metal concentrations since a substantial amount of metals was retained in the ash; a post-consumption waste that is difficult to collect. Batch leaching tests were performed to determine dissolved concentrations as a function of time. With the exceptions of As and (in most cases) Hg that were not detected, metals were released at varying rates. At 24 h of soaking the percentage of metals leached ranged from 0.2–43%. The contribution of paper, filter and tobacco to the dissolved concentrations at 24 h of leaching was investigated and in almost all cases tobacco was the major source of metal contamination. The dissolved concentrations from ash were low as metals were strongly bound. Varying the pH, ionic strength and humic acids content at environmentally relevant values did not affect leaching of metals at 24 h of soaking. The use of river water, rain water and seawater as leachants was also not found to alter dissolved concentrations at 24 h compared to ultrapure water. The results presented here suggest that the consequences of improper disposal of tobacco products in the environment are two-sided and that next to the generation of plastic litter, discarded tobacco products can also act as point sources of metal contamination. Public education campaigns focusing on the environmental impact and best disposal practices are urgently needed.Presented on: Science of the Total Environmen

Unexpected online gambling disorder in late-life:A case report

Background.The lifetime prevalence of problem or Gambling disorder (GD) in the elderly (i.e., those over 60 years old) is reported to range from 0.01% to 10.9%. Research has identified several specific risk factors and vulnerabilities in the elderly. Since the late 1990s, an increase in online GD has been observed in the youth population, whereas casinos, slot machines, and bingo seem to be the activities of choice among the elderly. Interestingly, online GD has not been described in the elderly to date.Case Description.We report an 83-year-old man who started online casino gambling from the age of 80 years, leading to debts that exceeded €30,000. He underwent a full clinical and neuropsychological assessment, without any evidence of cognitive impairment or any associated neurodegenerative disease. However, he had risk factors for GD, including adjustment disorder, stressful life events, previous offline casino GD when 50 years old, and dysfunctional personality traits. The change to online GD may have been due to his isolation, movement difficulties, and his high level of education, which facilitated his access to the Internet. Care management focused on individual cognitive-behavioral therapy.Conclusion.The prevalence of online GD may be underestimated among the elderly, and may increase among isolated old people with movement difficulties and ready access to the Internet. However, late-life GD should be considered a diagnosis of elimination, requiring a full medical, psychiatric (including suicide risk), and cognitive assessment. Specific therapeutic approaches need to be proposed and developed

Neural processing of emotions in traumatized children treated with Eye Movement Desensitization and Reprocessing therapy: A hdEEG study

Eye Movement Desensitization and Reprocessing (EMDR) therapy has been proven efficacious in restoring affective regulation in Post–Traumatic Stress Disorder (PTSD) patients. However, its effectiveness on emotion processing in children with complex trauma has yet to be explored. High density Electroencephalography (hdEEG) was used to investigate the effects of EMDR on brain responses to adults’ emotions on children with histories of early maltreatment. Ten school–aged children were examined before (T0) and within one month after the conclusion of EMDR (T1). hdEEGs were recorded while children passively viewed angry, afraid, happy, and neutral faces. Clinical scales were administered at the same time. Correlation analyses were performed to detect brain regions whose activity was linked to children’s traumatic symptom–related and emotional–adaptive problem scores. In all four conditions, hdEEG showed similar significantly higher activity on the right medial prefrontal and fronto–temporal limbic regions at T0, shifting towards the left medial and superior temporal regions at T1. Moreover, significant correlations were found between clinical scales and the same regions whose activity significantly differed between pre– and post–treatment. These preliminary results demonstrate that, after EMDR, children suffering from complex trauma show increased activity in areas implicated in high–order cognitive processing when passively viewing pictures of emotional expressions. These changes are associated with the decrease of depressive and traumatic symptoms, and with the improvement of emotional–adaptive functioning over time