The Impact of COVID-19 Confinement on Substance Use and Mental Health in Portuguese Higher Education Students.

The mental health of higher education students is a constant concern, and the pandemic situation caused by COVID-19 has intensified this concern. The social measures imposed to control and minimize the disease have led, among other things, to the reconfiguration of higher education students' academic life habits, which has naturally altered their emotional balance, mental health, and substance abuse. This cross-sectional, descriptive, and correlational study assesses the influence of higher education students' personal characteristics on their (self-reported) use of addictive substances (alcohol, tobacco, drugs, and pharmaceutical drugs) before and during their first compulsory confinement in Portugal, as well as its relationship with mental health. An online questionnaire was applied between 15 April and 20 May 2020, to students from various study cycles of higher education institutions in one region of Portugal (northern area of Alentejo), which included the Mental Health Inventory in its reduced version (MHI-5) and questions (constructed by the authors) on personal characterization and on the use of addictive substances before and during confinement. The convenience sample included 329 mostly female health care students between the ages of 18 and 24. In our results, we found a statistically significant decrease in tobacco, alcohol, and drug use; however, there was an increase in tobacco use among older students and an increase in anxiolytic use among students with higher academic achievement and among students who exhibited more active social behavior in the period prior to confinement. Students who took anxiolytics during confinement had higher MHI-5 scores and students who used the most addictive substances during confinement had lower MHI-5 scores than the other students.

Portuguese Version of the HLS-EU-Q6 and HLS-EU-Q16 Questionnaire: Psychometric Properties.

Health literacy refers to the competencies of individuals and the general population to navigate all the areas of health care, making health decisions. Health professionals need a set of skills and information to adapt to people's health literacy. To succeed, it is crucial to determine the health literacy level of a population, in this case, the Portuguese. This study aims to measure the psychometric properties of the Portuguese version of HLS-EU-Q16 and HLS-EU-Q6 from the long form of HLS-EU-Q47, already validated for Portugal. To analyse these results, a comparison was made with the HLS-EU-PT index. Spearman correlation analysis was performed between the single items and scale scores. Cronbach's alphas for all the indexes were calculated. For the statistical analysis, SPSS (version 28.0) was used. Cronbach's alpha coefficient for HLS-EU-PT-Q16 internal consistency was 0.89 overall, and for HLS-EU-PT-Q6 was 0.78 overall. Indexes were not normally distributed, and the Spearman correlation was computed. The correlation between G HL47 and G HL16 indexes was ρ = 0.95 (p < 0.001), and between G HL6 and HLS-EU-PT-Q6 was perfect. The HLS-EU-PT-Q16 and HLS-EU-PT-Q6 are concise and present adequate psychometric properties to measure the HL level of the Portuguese population. However, more similarities are found between the 47-item and the 16-item forms.

Depigmenting topical therapy based on a synergistic combination of compounds targeting the key pathways involved in melasma pathophysiology.

Melasma has a complex pathophysiology with different cell types and signalling pathways involved. Paracrine factors secreted by keratinocytes, fibroblasts and endothelial cells act on melanocytes and stimulate melanogenesis. These paracrine factors are involved in the oxidative stress, inflammatory, vascular and hormonal pathways, among others. Damage of the dermoepidermal barrier also occurs and facilitates melanin deposition in the dermis, also known as dermal or mixed melasma. We used artificial intelligence tools to define the best combination of compounds for skin pigmentation inhibition. Mathematical models suggested the combination of retinol, diosmin and ferulic acid to be the most effective one. In vitro cellular tyrosinase activity assay proved that this combination had a synergistic depigmenting effect. Further assays proved that the combination could inhibit key pathways involved in melasma by downregulating ET-1 and COX-2 gene expression and IBMX-induced dendricity in human melanocytes, and upregulated the gene expression of IL-1b, TIMP3 and several endogenous antioxidant enzymes. The combination also reduced melanin levels in a phototype VI 3D epidermis model. These results indicate that the combination of retinol, diosmin and ferulic acid is an effective synergistic complex for the treatment of melasma by regulating the key molecular pathways involved in skin hyperpigmentation pathophysiology.

Literacy and Mental Health of Portuguese Higher Education Students and Their Use of Health Promotion Strategies during Confinement in the COVID-19 Pandemic.

The pandemic of COVID-19 caused significant changes in economies and societies with a major impact on the entire education process. However, these changes did not invalidate a constant effort of adaptation. This cross-sectional, descriptive, and correlational study used an online questionnaire administered to students from various study cycles at higher education institutions in Portugal, with the aim of exploring the influence of literacy and mental health on the use of mental health promotion strategies during COVID-19 confinement. A total of 329 students from higher education institutions participated in this study, mostly from the age group 18-24 years (n = 272; 82.7%) and female (n = 265, 80.5%). The most mentioned health promotion strategies during this period included studying (n = 170; 51.7%); physical activities (n = 151, 45.9%); social networking (n = 124, 37.7%); cooking activities (n = 120, 36.5%); and listening to music (n = 118, 35.9%). Academic success is self-reported, and it is weakly correlated with the MHI5 (r = 0.103, p = 0.063). Students in the pre-graduate programs studied more during the times of the pandemic and used this activity as a mental-health-promoting strategy with a statistically significant difference (p = 0.033). Although it was difficult to improve health literacy related to COVID-19 in such a short period of time, there was a very strong motivation to access, understand, evaluate, communicate, synthesize, and apply information and knowledge to maintain mental health through self-care using health promotion strategies.

Advancements in the Use of Hydrogels for Regenerative Medicine: Properties and Biomedical Applications.

Due to their particular water absorption capacity, hydrogels are the most widely used scaffolds in biomedical studies to regenerate damaged tissue. Hydrogels can be used in tissue engineering to design scaffolds for three-dimensional cell culture, providing a novel alternative to the traditional two-dimensional cell culture as hydrogels have a three-dimensional biomimetic structure. This material property is crucial in regenerative medicine, especially for the nervous system, since it is a highly complex and delicate structure. Hydrogels can move quickly within the human body without physically disturbing the environment and possess essential biocompatible properties, as well as the ability to form a mimetic scaffold in situ. Therefore, hydrogels are perfect candidates for biomedical applications. Hydrogels represent a potential alternative to regenerating tissue lost after removing a brain tumor and/or brain injuries. This reason presents them as an exciting alternative to highly complex human physiological problems, such as injuries to the central nervous system and neurodegenerative disease.

Social Media Use and Its Association with Mental Health and Internet Addiction among Portuguese Higher Education Students during COVID-19 Confinement.

The use of social media was one of the most common way to keep in touch with friends and family during confinement. For higher education students, the fact that their universities were closed was a major change in their lives. The aim of this study is to relate the prevalence and type of social media with Internet addiction and mental health of university students in a district of Portugal during COVID-19 confinement. Mental health was studied by applying the reduced version of the Mental Health Inventory (MHI-5) and to measure the Internet use and dependence, the Internet Addiction Test (IAT) was used. The study (cross-sectional, descriptive, and correlational) used an online questionnaire, conducted on Google® Forms and the link was sent to 4450 students, in the months of April to June 2020, during the confinement. A total of 329 valid questionnaires were obtained. We can conclude that regarding mental health, students in the 18-24 age group, single or divorced and who are not in a relationship, and with worse academic results, show worse levels of mental health. It is noteworthy that the students with the same characteristics also have the highest levels of addiction to internet.

Association Between Food Choices Motivators and Physical Activity in Body Image (dis)Satisfaction in Portuguese Adolescents.

Concerns about weight and body image are common among adolescents since they are particularly vulnerable to body-image dissatisfaction due to the normal physiological, social, and psychological changes they are going through. This study aims to analyse the relationship between food choice motivations and physical activity in body-image perception among adolescents. Twelve to sixteen years old adolescents were recruited from three school districts. The Portuguese version of the Food Choices Questionnaire (FCQ) was used to assess food choice motivators, and the Quantification de l'Activité Physique en Altitude Chez les Enfants was used to assess physical activity and to calculate daily energy expenditure (DEE). Body image perception was measured using Collins' sequence of seven silhouettes. Body image (dis)satisfaction was estimated by the present body shape minus the desired body shape. ANOVA and Kruskal-Wallis tests were performed to compare groups, and the post-hoc Bonferroni test was used to compare target groups. A multinominal logistic regression was performed to analyse the association between gender, age, hours of sport's competition, FCQ, and body dissatisfaction. All analyses were performed in IBM SPSS Statistics 26.0. The sample comprised 286 adolescents (51.4% females). Means of FCQ categories varied between 0.33 and 0.97 (range: -2 to 2). Regarding the categories of FCQ, statistically significant differences were found in the category of body satisfaction and weight control among the three groups (p = 0.004). A preventive effect was found of choosing food regarding body satisfaction and weight control, on body-image dissatisfaction.

Overfeeding During Lactation in Rats is Associated with Cardiovascular Insulin Resistance in the Short-Term.

Childhood obesity is associated with metabolic and cardiovascular comorbidities. The development of these alterations may have its origin in early life stages such as the lactation period through metabolic programming. Insulin resistance is a common complication in obese patients and may be responsible for the cardiovascular alterations associated with this condition. This study analyzed the development of cardiovascular insulin resistance in a rat model of childhood overweight induced by overfeeding during the lactation period. On birth day, litters were divided into twelve (L12) or three pups per mother (L3). Overfed rats showed a lower increase in myocardial contractility in response to insulin perfusion and a reduced insulin-induced vasodilation, suggesting a state of cardiovascular insulin resistance. Vascular insulin resistance was due to decreased activation of phosphoinositide 3-kinase (PI3K)/Akt pathway, whereas cardiac insulin resistance was associated with mitogen-activated protein kinase (MAPK) hyperactivity. Early overfeeding was also associated with a proinflammatory and pro-oxidant state; endothelial dysfunction; decreased release of nitrites and nitrates; and decreased gene expression of insulin receptor (IR), glucose transporter-4 (GLUT-4), and endothelial nitric oxide synthase (eNOS) in response to insulin. In conclusion, overweight induced by lactational overnutrition in rat pups is associated with cardiovascular insulin resistance that could be related to the cardiovascular alterations associated with this condition.

Controlled trial of an mHealth intervention to promote healthy behaviours in adolescence (TeenPower): Effectiveness analysis.

AIM: To evaluate the effectiveness on lifestyle change of an mHealth intervention to promote healthy behaviours in adolescence (TeenPower) and to analyse the predictors of the mHealth intervention effectiveness. DESIGN: This study is designed as a non-randomized controlled trial with a two-arm structure. METHODS: Adolescents of 12-16-year old were recruited from three school districts, with access to the Internet and smartphone/tablet devices. The intervention group was invited to engage in the mHealth intervention (TeenPower) for 6 months in addition to a school-based intervention. The control group only followed the school-based intervention. A repeated measures factorial ANOVA was used and the main effectiveness outcome was the lifestyle change measured by the adolescent lifestyle profile. RESULTS: The outcomes of the mHealth intervention (TeenPower) show a significant effect on nutrition (ƞ2 p  = 0.03, p = .03), positive life perspective (ƞ2 p  = 0.04, p = .01), and global lifestyle (ƞ2 p  = 0.02, p = .05), with a dropout rate of 62.1%. The analysis of the effectiveness predictors of the mHealth intervention suggested that older adolescents tended to show a significant increase in the rates of stress management (r = .40; p < .05). CONCLUSIONS: Although the considerable dropout rate, the mHealth intervention presented significant impact on multiple lifestyle domains, providing support for the effectiveness of mHealth interventions for health promotion as an add-on to standard interdisciplinary interventions. IMPACT: Adolescents must have the necessary and appropriate knowledge for the correct and responsible decision-making regarding their health and lifestyle. Innovative strategies (mHealth intervention) were used to promote healthy behaviours. This study evaluates the effectiveness of an mHealth intervention (TeenPower) specifically designed for adolescents. We found a significant impact in several lifestyle domains such as health responsibility, nutrition, positive life perspective, and global lifestyle.

Association of rs712 polymorphism in a let-7 microRNA-binding site of KRAS gene with colorectal cancer in a Mexican population.

OBJECTIVES: The rs712 polymorphism in a let-7 microRNA-binding site at KRAS gene has been associated with cancer. To examine its association with rs712 polymorphism, we analyzed Mexican individuals with colorectal cancer (CRC) and healthy subjects. MATERIALS AND METHODS: Genotyping of the rs712 polymorphism was performed by polymerase chain reaction in 281 controls and 336 CRC patients. RESULTS: The observed frequencies of rs712 polymorphism indicated an associated protective factor for CRC (P=0.032). An association between genotype and the disease was evident in: colon localization (allele T, odds ratio (OR) 3.82, 95% confidence Intervals (CI) 2.77-5.28, P=0.0001), node metastasis (genotype TT, OR 2.49, 95% CI 1.45-4.28, P=0.0009), poor differentiation (genotype GT, OR 2.35, 95% CI 1.35-4.1, P=0.0033), and poor chemotherapy response (genotype GT, OR 2.6, 95% CI 1.7-4.24, P=0.0001). CONCLUSION: Comparison of the data from patients with control group showed that polymorphism of rs712 in KRAS gene was protective factor, which was associated with susceptibility for CRC. However, the genotypes TT and GT of rs712 polymorphism in KRAS could contribute significantly to colon localization, node metastasis, poor differentiation and poor chemotherapy response in CRC patients in this sample population.

An mHealth intervention programme to promote healthy behaviours and prevent adolescent obesity (TeenPower): A study protocol.

AIM: This paper describes the design and rationale of multicenter practice-based research that aims to develop and evaluate an innovative mobile health (mHealth) intervention programme directed to promote healthy behaviours and prevent adolescent obesity. DESIGN: This study is designed as a non-randomized controlled trial with a three-arm structure. METHODS: Twelve to 16 years old participants will be recruited from schools, with access to the Internet and smartphone/tablet devices. The intervention group will be invited to engage in the TeenPower mHealth programme and divided into two subgroups: Group A (additionally engaged in a structured school-based intervention programme) and Group B (only engaged in the mHealth programme). The mHealth app includes educational resources, self-monitoring, social support, interactive training modules and motivational tools. The control group will only follow the structured school-based intervention programme. The intervention length will be 3 months, including the direct support of an interdisciplinary team (nursing, nutrition, sports, psychology, among others). This research was approved and funded in August 2017. DISCUSSION: The positive evaluation of the intervention programme will stimulate the inclusion of technologies in the promotion of salutogenic behaviours and obesity prevention. IMPACT: Adolescent obesity reached epidemic proportions. It is urgent to find effective prevention strategies to induce change at the individual, family and community level. If effective, this protocol can be used by health and exercise professionals in improving community interventions tailored to teenagers.

Validation of the EuroSCORE model in patients undergoing heart surgery in Regional Hospital of High Speciality of Bajio / Validación del modelo EuroSCORE en pacientes sometidos a cirugía cardiaca en el Hospital Regional de Alta Especialidad del Bajío

Abstract: Introduction: EuroSCORE is a probabilistic model with good performance in the prognosis of mortality in heart surgery in many latitudes. It is recommendable to validate it in hospitals where it is employed. Objective: To validate the EuroSCORE model in adult patients at the Hospital Regional de Alta Especialidad del Bajío (HRAEB) of León, Guanajuato, Mexico. Material and methods: We conducted an observational transversal, and retrospective study, accomplishing this through the review of the clinical files of patients submitted to heart surgery with and without extracorporeal circulation pump from 01/01/2008 to 12/31/2013 at the HRAEB. This included mortality up to hospital discharge, utilizing the on-line calculator of the EuroSCORE program to estimate risk of death. In order to validate the EuroSCORE model, we assessed discrimination and calibration through the Area Under the receiver operating characteristics (ROC) curve and χ2 test with Hosmer-Lemeshow (H-L) goodness-of-fit, respectively. Results: A total of 342 patients, aged 50.02 ± 16.66 years, 181 males (52.9%) and 161 women (47.1%). The area under the ROC curve of the additive model was 0.763, and of the Hosmer-Lemeshow test was 5.30, with p = 0.62. The area under the ROC curve of the logistic model was 0.761 and of the Hosmer-Lemeshow test, 8.78, with p = 0.36. Conclusion: The EuroSCORE model is a reliable score for estimating the probabilities of death in adult patients submitted to heart surgery with or without the pump at the HRAEB.

Resumen: Introducción: EuroSCORE es un modelo probabilístico con buen desempeño en el pronóstico de mortalidad en cirugía cardiaca en muchas latitudes. Es recomendable validarlo en los hospitales donde se emplea. Objetivo: Validar el modelo EuroSCORE en pacientes adultos en el Hospital Regional de Alta Especialidad del Bajío (HRAEB) de León, Guanajuato, México. Material y métodos: Se realizó un estudio observacional transversal y retrospectivo, que se completó con la revisión de los expedientes clínicos de pacientes sometidos a cirugía cardiaca con y sin bomba de circulación extracorpórea desde el 01/01/2008 hasta el 31/12/2013 en el HRAEB. Esto incluyó la mortalidad hasta el alta hospitalaria, utilizando la calculadora en línea del programa EuroSCORE para estimar el riesgo de muerte. Para validar el modelo EuroSCORE, evaluamos la discriminación y la calibración a través de la curva de características de operación del receptor (ROC) y la prueba de χ2 con la efectividad de ajuste de Hosmer-Lemeshow (H-L), respectivamente. Resultados: Un total de 342 pacientes, de 50.02 ± 16.66 años, 181 hombres (52.9%) y 161 mujeres (47.1%). El área bajo la curva ROC del modelo aditivo fue de 0.763, y la de la prueba Hosmer-Lemeshow fue de 5.30, con p = 0.62. El área bajo la curva ROC del modelo logístico fue 0.761 y de la prueba Hosmer-Lemeshow, 8.78, con p = 0.36. Conclusión: El modelo EuroSCORE es una herramienta confiable para estimar las probabilidades de muerte en pacientes adultos sometidos a cirugía cardiaca con o sin bomba en el HRAEB.

Effects of emerging contaminants on neurotransmission and biotransformation in marine organisms - An in vitro approach.

The effects of gold (ionic form and nanoparticles - AuNPs) and pharmaceuticals (carbamazepine and fluoxetine) on enzymes involved in neurotransmission (acetylcholinesterase - AChE) and biotransformation (glutathione S-transferases - GST) were assessed by their incubation with Mytilus galloprovincialis' hemolymph and subcellular fraction of gills, respectively. AuNPs did not alter enzymatic activities unlike ionic gold that inhibited AChE and GST activities at 2.5 and 0.42mg·L(-1), respectively. Carbamazepine inhibited AChE activity at 500mg·L(-1) and fluoxetine at 1000mg·L(-1). GST was inhibited by carbamazepine at 250mg·L(-1) and by fluoxetine at 125mg·L(-1). Increased AChE activity was found in simultaneous exposures to fluoxetine and bovine serum albumin coated AuNPs (BSA-AuNPs). Concerning GST, in the simultaneous exposures, AuNPs revealed protective effects against carbamazepine (citrate and polyvinylpyrrolidone coated) and fluoxetine (citrate and BSA coated) induced inhibition. However, BSA-AuNPs increased the inhibition caused by carbamazepine. AuNPs demonstrated ability to interfere with other chemicals toxicity justifying further studies.

In vitro study of the effect of an essential oil and a delmopinol mouth rinse on dental plaque bacteria.

CONTEXT: Mouthrinses are used, by many of our patients, as a complement to daily dental hygiene routine. The use of a toothbrush and an interproximal cleaning method may not be enough to control dental plaque. Essential oils and delmopinol mouth rinses are effective for the prevention of dental caries and gingivitis. To study the effect of an essential oil and a delmopinol mouth rinse on dental plaque bacteria, an in vitro study was developed. AIMS: The objective of this study was to determine the antibacterial activity of an essential oil and a delmopinol mouth rinse on Streptococcus mutans, Lactobacilli, and aerobic and anaerobic dental plaque nonspecific bacteria. DESIGN: Samples of human dental plaque were collected from consenting participants and bacteria isolated. Disk-diffusion tests were performed to obtain the minimum concentration of the mouth rinses necessary to inhibit bacterial growth. The ability of the commercial mouth rinses to inhibit bacterial growth was studied in comparison to a positive control (0.2% chlorhexidine) and a negative laboratorial control (sterilized water). RESULTS: The minimum inhibitory concentration was found to be inferior to the commercial essential oils and delmopinol mouth rinses concentrations. Delmopinol and essential oils have significant antibacterial properties shown in vitro only for aerobic bacteria, and for S. mutans, Lactobacillus, and anaerobic bacteria, the results were not statistically significant. CONCLUSIONS: Essential oils and chlorhexidine are statistically similar and better than delmopinol for aerobic bacteria growth inhibition. For the other bacteria, essential oils and delmopinol are not statistically promising. Results show that essential oils only may help patients to maintain good oral health as a complement to daily brushing and interproximal cleaning.

Oral health habits, attitudes and behaviors of Portuguese adolescents.

PURPOSE: Oral health has a profound impact on the health of adolescents. The aim of the present study was to obtain information on habits, knowledge and oral hygiene attitudes of Portuguese teenagers and to study the gender differences concerning these issues. METHODS: A total of 1203 adolescents participated in the study (55.8% females; mean age, 14.9 years). To recruit participants, a national network of community dental hygienists, working in the health centers, was created, and adolescents were contacted at the schools. A questionnaire was applied in the classroom, during school hours, under supervision of one researcher and the classroom teacher, after collection of informed consent forms. RESULTS: Portuguese adolescents do not seem to have dental fear but have some anxiety when at the dental office; girls are more anxious than boys. Girls are also more concerned with esthetics and aware of dental problems and care about oral health of family and friends. Parental supervision is more relevant for boys in order to obtain better compliance with dental care; however, 97.2% of the adolescents do not consider maintaining teeth throughout the lifetime as relevant. CONCLUSION: Teenagers recognize dental professionals as educators and oral health as relevant in their lives. It is possible to assume that gender has an influence on adolescent's habits, behavior and attitudes regarding oral hygiene. There is a difference between boys and girls concerning their habits, knowledge and attitudes in dental hygiene; this difference may show the need to create different strategies for oral health promotion for these two groups of adolescents.

Does the presence of microplastics influence the acute toxicity of chromium(VI) to early juveniles of the common goby (Pomatoschistus microps)? A study with juveniles from two wild estuarine populations.

Toxicological interactions between microplastics (MP) and other environmental contaminants are of grave concern. Here, the potential influence of MP in the short-term toxicity of chromium to early juveniles of Pomatoschistus microps was investigated. Three null hypotheses were tested: (1) exposure to Cr(VI) concentrations in the low ppm range does not induce toxic effects on juveniles; (2) the presence of microplastics in the water does not influence the acute toxicity of Cr(VI) to juveniles; (3) the environmental conditions of the natural habitat where fish developed do not influence their sensitivity to Cr(VI)-induced acute stress. Fish were collected in the estuaries of Minho (M-est) and Lima (L-est) Rivers (NW Iberian Peninsula) that have several abiotic differences, including in the water and sediment concentrations of various environmental contaminants. After acclimatization to laboratory conditions, two 96h acute bioassays were carried out with juveniles from both estuaries to: (i) investigate the effects of Cr(VI) alone; (ii) investigate the effects of Cr(VI) in the presence of MP (polyethylene spheres 1-5µm ∅). Cr(VI) alone induced mortality (96h-LC50s: 14.4-30.5mg/l) and significantly decreased fish predatory performance (≤74%). Thus, in the range of concentrations tested (5.6-28.4mg/l) Cr(VI) was found to be toxic to P. microps early juveniles, therefore, we rejected hypothesis 1. Under simultaneous exposure to Cr(VI) and MP, a significant decrease of the predatory performance (≤67%) and a significant inhibition of AChE activity (≤31%) were found. AChE inhibition was not observed in the test with Cr(VI) alone and MP alone caused an AChE inhibition ≤21%. Mixture treatments containing Cr(VI) concentration ≥3.9mg/l significantly increased LPO levels in L-est fish, an effect that was not observed under Cr(VI) or MP single exposures. Thus, toxicological interactions between Cr(VI) and MP occurred, therefore, we rejected hypothesis 2. In the presence of MP, the negative effect caused by high concentrations of Cr(VI) on the predatory performance was significantly reduced in L-est fish but not in M-est fish, and Cr(VI) concentrations higher than 3.9mg/l caused oxidative damage in L-est fish but not in M-est fish. The acclimatization and test conditions were similar for fish from the two estuaries and these ecosystems have environmental differences. Thus, long-term exposure to distinct environmental conditions in the natural habitat during previous developmental phases influenced the sensitivity and responses of juveniles to Cr(VI), therefore, we rejected hypothesis 3. Overall, the results of this study indicate toxicological interactions between MP and Cr(VI) highlighting the importance of further investigating the combined effects of MP and other common contaminants.

Effects of microplastics on juveniles of the common goby (Pomatoschistus microps): confusion with prey, reduction of the predatory performance and efficiency, and possible influence of developmental conditions.

Microplastics (MP) are ubiquitous contaminants able to cause adverse effects on organisms. Three hypotheses were tested here: early Pomatoschistus microps juveniles can ingest MP; the presence of MP may reduce fish predatory performance and efficiency; developmental conditions may influence the preyselection capability of fish. Predatory bioassays were carried out with juveniles from two estuaries with differences in environmental conditions: Minho (M-est) and Lima (L-est) Rivers (NW Iberian coast). Polyethylene MP spheres (3 types) alone and in combination with Artemia nauplii were offered as prey.All the MP types were ingested, suggesting confusion with food. Under simultaneous exposure to MP and Artemia, L-est fish showed a significant reduction of the predatory performance (65%) and efficiency (upto 50%), while M-est fish did not, suggesting that developmental conditions may influence the preyselection capability of fish. The MP-induced reduction of food intake may decrease individual and population fitness.

Comparative analyses of the ß-tubulin gene and molecular modeling reveal molecular insight into the colchicine resistance in kinetoplastids organisms.

Differential susceptibility to microtubule agents has been demonstrated between mammalian cells and kinetoplastid organisms such as Leishmania spp. and Trypanosoma spp. The aims of this study were to identify and characterize the architecture of the putative colchicine binding site of Leishmania spp. and investigate the molecular basis of colchicine resistance. We cloned and sequenced the ß-tubulin gene of Leishmania (Viannia) guyanensis and established the theoretical 3D model of the protein, using the crystallographic structure of the bovine protein as template. We identified mutations on the Leishmania ß-tubulin gene sequences on regions related to the putative colchicine-binding pocket, which generate amino acid substitutions and changes in the topology of this region, blocking the access of colchicine. The same mutations were found in the ß-tubulin sequence of kinetoplastid organisms such as Trypanosoma cruzi, T. brucei, and T. evansi. Using molecular modelling approaches, we demonstrated that conformational changes include an elongation and torsion of an α-helix structure and displacement to the inside of the pocket of one ß-sheet that hinders access of colchicine. We propose that kinetoplastid organisms show resistance to colchicine due to amino acids substitutions that generate structural changes in the putative colchicine-binding domain, which prevent colchicine access.

Short-term toxic effects of naphthalene and pyrene on the common prawn (Palaemon serratus) assessed by a multi-parameter laboratorial approach: mechanisms of toxicity and impairment of individual fitness.

The short-term (96 h) toxic effects of two polycyclic aromatic hydrocarbons (PAHs), naphthalene (NAP) and pyrene (PYR), on the common prawn (Palaemon serratus) were investigated in laboratory bioassays, including a fitness related assay based on the post-exposure swimming velocity. Other effect criteria were biomarkers of neurotoxicity, oxidative stress and bioenergetics, and mortality. In the range of concentrations tested (NAP: 0.13-8 mg/L; PYR: 0.006-0.4 mg/L), both PAHs impaired the swimming velocity, induced oxidative stress and damage, and changed the activity of lactate dehydrogenase and isocitrate dehydrogenase. NAP also caused mortality (96 h-LC50=3.5 mg/L). Thus, both PAHs were able to cause toxic effects on P. serratus after a short period of exposure through the water, including the reduction of individual fitness. PYR was five folds more effective in reducing the swimming velocity of P. serratus than NAP. These findings are of interest for the marine ecological risk assessment of oil spills.