A Multiplex Molecular Cell-Based Sensor to Detect Ligands of PPARs: An Optimized Tool for Drug Discovery in Cyanobacteria

Cyanobacteria produce a wealth of secondary metabolites. Since these organisms attach fatty acids into molecules in unprecedented ways, cyanobacteria can serve as a novel source for bioactive compounds acting as ligands for Peroxisome Proliferator-Activated Receptors (PPAR). PPARs (PPARα, PPARβ/δ and PPARγ) are ligand-activated nuclear receptors, involved in the regulation of various metabolic and cellular processes, thus serving as potential drug targets for a variety of pathologies. Yet, given that PPARs' agonists can have pan-, dual- or isoform-specific action, some controversy has been raised over currently approved drugs and their side effects, highlighting the need for novel molecules. Here, we expand and validate a cell-based PPAR transactivation activity biosensor, and test it in a screening campaign to guide drug discovery. Biosensor upgrades included the use of different reporter genes to increase signal intensity and stability, a different promoter to modulate reporter gene expression, and multiplexing to improve efficiency. Sensor's limit of detection (LOD) ranged from 0.36-0.89 nM in uniplex and 0.89-1.35 nM in multiplex mode. In triplex mode, the sensor's feature screening, a total of 848 fractions of 96 cyanobacteria extracts were screened. Hits were confirmed in multiplex mode and in uniplex mode, yielding one strain detected to have action on PPARα and three strains to have dual action on PPARα and -β.

The effects of COVID-19 on female and male bike sharing users: Insights from Lisbon's GIRA

Women are among the groups most affected by the pandemic as they are more likely to be dependent on public transport (PT), which was heavily restricted during COVID-19. Thus, there is a need to consider transport alternatives such as bike sharing that can ensure their mobility needs. By conducting a survey to the bike sharing system (BSS) of Lisbon, we explored differences in travel behaviour and attitudes between female and male users before and during COVID-19. We found men to have higher bike ownership rates, a higher modal share of personal bicycle regarding commuting, and more likely to use their own bikes if BSS was unavailable. Conversely, women more frequently combined BSS with PT and were more likely to use PT if BSS was unavailable. Moreover, while men were using BSS more frequently than women pre-pandemic, during COVID-19 women are using BSS as frequently as men. Our research provides evidence on the potential role of BSS as a transport alternative during pandemics, inducing women to take up cycling who otherwise would not cycle, therefore, potentially decreasing the current cycling gender gap. Findings suggest that introducing family/friend discounts and promoting BSS for exercising may increase the share of female cyclists.

Proteogenomic Characterization of the Cement and Adhesive Gland of the Pelagic Gooseneck Barnacle Lepas anatifera

We focus on the stalked goose barnacle L. anatifera adhesive system, an opportunistic less selective species for the substrate, found attached to a variety of floating objects at seas. Adhesion is an adaptative character in barnacles, ensuring adequate positioning in the habitat for feeding and reproduction. The protein composition of the cement multicomplex and adhesive gland was quantitatively studied using shotgun proteomic analysis. Overall, 11,795 peptide sequences were identified in the gland and 2206 in the cement, clustered in 1689 and 217 proteinGroups, respectively. Cement specific adhesive proteins (CPs), proteases, protease inhibitors, cuticular and structural proteins, chemical cues, and many unannotated proteins were found, among others. In the cement, CPs were the most abundant (80.5%), being the bulk proteins CP100k and -52k the most expressed of all, and CP43k-like the most expressed interfacial protein. Unannotated proteins comprised 4.7% of the cement proteome, ranking several of them among the most highly expressed. Eight of these proteins showed similar physicochemical properties and amino acid composition to known CPs and classified through Principal Components Analysis (PCA) as new CPs. The importance of PCA on the identification of unannotated non-conserved adhesive proteins, whose selective pressure is on their relative amino acid abundance, was demonstrated.

Allergic sensitization to storage dust mites: a prospective study of patients with respiratory allergy

Summary

Objectives. To describe the prevalence of allergic sensitization to Storage Dust Mites (SDM), access whether the place of living and occupational exposure were determinants for SDM sensitization and study association between Lepidoglyphus destructor and other SDM sensitization. Methods. Prospective analysis of patients evaluated for suspected allergic rhinitis and/or asthma that performed Skin Prick Tests (SPT) to SDM between January and December 2018 in our Department. Results. Two hundred consecutive patients were evaluated for rhinitis and/or asthma in our outpatient consultation: 123 (61.5%) presented positivity for at least one SDM, 68.3% were female and the mean age was 33.1 ± 12.12. Lepidoglyphus destructor (69.9%) was the most prevalent, followed by Tyrophagus putrescentiae (50.4%), Blomia tropicalis and Glycyphagus domesticus (48.8%) and Acarus siro (24.4%). Living in a rural place was not associated with a higher prevalence of sensitization to SDM, except for Acarus siro (p = 0.032), and working in a place with storage areas was not associated with sensitization to any of SDM. Sensitization to Lepidoflyphus destructor was associated with sensitization to Blomia tropicalis, Glycyphagus domesticus and Tyrophagus putrescentiae (p less than 0.005), but not with Acarus siro. Conclusions. Our study suggests that our population, independently of their occupational exposure and place of residency, are sensitized to SDM and that evaluation of sensitization to SDM should be considered as standard practice.

A silent “shipyard eye”: lessons from an epidemic keratoconjunctivitis outbreak in Portugal

Issue

Adenoviral conjunctivitis is the most common cause of conjunctivitis. Its most severe form is epidemic keratoconjunctivitis (EKC). This highly contagious disease is the only form to significantly involve the cornea and may cause visual impairing sequelae that persist for years.

Description

On January 2020, staff members at a childcare facility (CCF) alerted the Public Health Unit of Loures-Odivelas to a suspected conjunctivitis outbreak. The CCF was responsible for 57 children, separated in different rooms: a nursery (4-12 months), a pre-school (1-3 years) and a kindergarten (4-5 years). At the initial assessment, 4 cases of active disease were identified, all of which were at home and under treatment. CCF staff had previously identified 33 cases. Symptom onset of the index case had occurred more than 5 weeks before the alert. Infection control and epidemiological investigation were initiated. CCF staff was instructed to implement preventive measures, including careful disinfection of surfaces and toys, as well as frequent handwashing. Information about the disease and recommendations were sent to the children's caretakers.

Results

A total of 87 cases distributed in 8 weeks were identified: 28 at the CCF (25 children and 3 workers) and 59 close contacts (50 adults and 9 children). Average duration of disease was 14.1 days. In total, 43.9% of the children attending the CFF were affected. The highest attack rate was observed at the pre-school (69.2%, against 38.9% and 17.6% at the nursery and the kindergarten, respectively). 88.0% of the CCF children's households were affected. The average number of affected close contacts per affected child attending the CCF was 2.63. Corneal involvement was observed in 17,4% of cases.

Lessons

EKC outbreaks may go unnoticed by public health services, despite its high contagiousness and impact. Improvement of communication with organizations in the community is essential to secure future early detection and intervention.

Key messages

Epidemic keratoconjunctivitis is a highly contagious disease with potential long-term consequences. Early detection and intervention by public health services are essential to mitigate the impact of outbreaks and depend on well-established communication lines with institutions in the community.

HIV infection and AIDS reported cases in two municipalities near Lisbon between 2015 and 2019

Background

In the WHO European Region, in 2018, there were 16.2 newly diagnosed HIV infections per 100,000. In Portugal, there were 9.5 new cases per 100,000 population. The aim of this study is to analyse HIV/AIDS's notifications in the group of primary healthcare centres of Loures-Odivelas (ACES LO), with 340,000 inhabitants, between 2015 and 2019.

Methods

An observational, descriptive, retrospective, quantitative study was performed. Data was collected in March 2020, from the National System of Epidemiological Surveillance Database. Variables included were age, sex, HIV's presentation, country of probable origin of infection, probable form of transmission, partner characteristics, pregnancy at diagnosis, reason for testing/consultation, anti-retroviral therapy (ART) before diagnostic of AIDS. Descriptive analysis was performed for all variables.

Results

In ACES LO, there were 83 notified cases of HIV infection/AIDS between 2015 and 2019, with 36.1% of cases notified in 2019. The male to female ratio was 1.4. The average age was 41.7 years old. At time of notification, 56.6% of cases were asymptomatic and 25.3% had clinical criteria for AIDS. Guinea-Bissau was the probable origin of infection in 43.0% of cases (n = 23). Men having sex with men (MSM) was the probable form of transmission in 19.3% of cases. In 19.6% of cases of heterosexual contact, the partner was known to have HIV infection. Six women were pregnant at time of diagnosis. Testing was done on a routine basis in 22.2% of cases (n = 54). Among those with clinical criteria for AIDS (n = 21), 5 cases had previously taken ART.

Conclusions

There was an increase in notified cases of HIV infection/AIDS from 2015 to 2019 in ACES LO. The male to female ratio was lower than for Portugal in 2018.The proportion of cases with AIDS at time of notification was higher than for Portugal in 2018. Preventive strategies should be reinforced for people with partners diagnosed with HIV infection and perhaps for people.

Key messages

More than one third of cases were notified in 2019. Preventive strategies should be reinforced for people with partners diagnosed with HIV infection.

Notification of sexually transmitted infections: the tip of the iceberg?

Background

Sexually transmitted infections (STIs) are a major public health problem in Europe and in Portugal, their incidence has been increasing since the 90s. Although STIs are among the most frequently reported infections globally, they still go often underdiagnosed. Their under notification is also a problem in Portugal. The aim of this study is to describe STIs' notifications in the area of the groups of primary healthcare centers of Loures-Odivelas (ACES LO), between 2015-2019.

Methods

An observational, descriptive, quantitative study was performed. Data was collected in January 2020, from the National System of Epidemiological Surveillance Database. Variables included for each STIs notification were age and sex. Univariate descriptive analysis and evolution trends were performed for each variable.

Results

A total of 638 cases of STIs were reported from 2015 to 2019. The number of reported cases increased from 87 to 197 cases (126.4%). The annual mean incidence of HBV and HCV notifications were 8 and 4, respectively. There was an increase in reported cases of syphilis (33 to 57), HIV (13 to 29), chlamydia (13 to 46) and gonorrhea (18 to 51). In 2019, 30.9% of the notified cases were syphilis infections, 23.5% gonorrhea infections, 22.1% chlamydia infections and 13.2% HIV infections.Males comprised 460 cases (72.1%), and, in patients aged between 15 and 44 years old, 484 cases (75.9%) were reported. From 2015 to 2019, the co-infections of gonorrhea and chlamydia increased from 2 to 10 cases (25.0%). In 2019, 17.5% of the notified cases of gonorrhea were co-infections.

Conclusions

The modification of risk behaviors and the appropriate treatment of infected people, including infected partners, are determinant to prevent recurrent infections and to interrupt the transmission cycle. Increasing notification should facilitate the monitoring of STIs' trends, contributing to the implementation of appropriate interventions and for better decision-making in public health.

Key messages

Campaigns about sexual health promotion are important to increase safer sexual health practices. More notifications contribute to better data quality and more robust decision-making.

A retrospective study of an International Vaccination Centre in the Lisbon Metropolitan Area

Background

Vaccination is one of the most cost-effective disease prevention strategies. Trips from Portugal to other countries have increased in the past 5 years. Depending on the destination, certain vaccines are advised to travellers in order to reduce travel-related risk. We analyzed the data of an International Vaccination Centre (IVC) in the Public Health Unit of the Primary Care Centres Group (ACES) of Loures-Odivelas.

Methods

A retrospective observational study comprising data from an IVC database between 2014 and 2018. Variables included were sex, age, destination, purpose, referral, and prescriptions. Descriptive analyses were performed for all variables.

Results

Between 2014 and 2018, there was a total of 4,873 users. Regarding individual characteristics, 51% were female, 80% had between 15 and 64 years of age, and 51% were referred by general practitioners of the ACES. Africa was the leading destination (66% average for all years) with a downward trend (from 82% in 2014 to 47% in 2018) followed by South America (12%) with an upward trend (from 4% to 16% in the same period). The primary purpose of travelling was tourism (74%) followed by work (15%). A total of 7,323 vaccines were administered, with an annual increase from 1,250 administrations in 2014 to 1,862 in 2018. The yellow fever vaccine accounted for 36,9% of all administrations, followed by typhoid fever vaccine (32,3%) and hepatitis A vaccine (10,2%).

Conclusions

African countries are still the most common destination for Portuguese travellers, but changing trends might influence the vaccination strategies in the IVC. Information provided in the IVC can be optimized to suit individual profiles better.

Key messages

As travelling increases, the International Vaccination Centre has an essential role in the prevention of disease. Africa remains the most common destination, requiring pre-travel health counselling and vaccine prophylaxis.

A retrospective study of a pre-travel consultation in the Lisbon Metropolitan Area, Portugal

Background

Travel from Portugal to other countries has increased in the past 5 years. A pre-travel health consultation is advised to all travellers to raise awareness and reduce travel-related risk. We describe the experience of a pre-travel consultation centre in the public health service.

Methods

A retrospective observational study about consultations in an international vaccination centre between 2014-2018. Variables included were: sex, age, destination, purpose, referral, and prescriptions. Descriptive analyses were performed for all variables.

Results

Between 2014 and 2018, there were 1,546 consultations. Regarding individual characteristics, 54% were female, and 80% had between 15 and 64 years of age. There was no referral in 66% of the consultations, followed by 16% from general practitioners in the Primary Care Centres Group. The leading destination was Africa (54%), in a downward trend (74% in 2015 and 32% in 2018) followed by Asia (18%) with an upward trend (12% to 28% in the same period). The primary purpose was tourism (83%), followed by work (9%). In total, 3,287 vaccines were prescribed with typhoid fever vaccine accounting for 26%, hepatitis A vaccine 22%, and yellow fever vaccine 15%. Mefloquine was the primary therapeutic drug prescribed for destinations with risk for malaria (41%). Regarding destinations with low risk for malaria, in 42% of the consultations, personal protective measures were the only recommendation.

Conclusions

Our data show that pre-travel consultations seem to be valued and actively asked for by travellers, but medical referral is still insufficient. Regarding health promotion and prevention of diseases, tracking trends in the most common destinations allows to optimize the information provided in the consultation, effectively capacitating the traveller to recognize and act on the most common travel-related health risks. In further studies, a post-travel follow-up should be carried out to determine the impact of the consultation.

Key messages

Pre-travel consultation is an actively sought-after service by the community, but awareness should be promoted in the medical community. Pre-travel consultation can have an important role in the health literacy of travellers.

Tuberculosis’ surveillance in a group of primary healthcare centres of Lisbon district

Background

Tuberculosis (TB), a communicable disease, is the leading cause of death from a single infectious agent and one of the top 10 causes of death worldwide. Its burden varies among different countries. In the 31 European Economic Area member states, in 2017, the TB notification rate was 10.7/100,000 population; in Portugal, this rate was 17.5/100,000 population and the majority of the notified cases occurred in two districts: Lisbon and Oporto. The aim of this study is to analyse TB's notifications in a group of primary healthcare centres of Loures-Odivelas (ACES LO), between 2015 and 2019.

Methods

An observational, descriptive, retrospective, quantitative study was performed. Data was collected in January 2020, from the National System of Epidemiological Surveillance Database. Variables included were: age, sex, TB's presentation, antimicrobial susceptibility testing, HIV testing. Descriptive analysis was performed for all variables.

Results

In ACES LO, notified cases of TB dropped 18.0% between 2015 and 2017, having since increased by 54.8% (n = 113), a notification rate of 32.3/100,000 population in 2019. The male to female ratio was 1.7 and the most affected age group was the 30-40 year old group (n = 25). Notified cases in children <10 years old have increased from 0 in 2016 to 7 in 2019. Pulmonary TB was reported in 73.5% (n = 83) of the notified cases; in 56.6% (n = 64), antimicrobial susceptibility testing revealed that first-line treatment would be effective; HIV testing was positive in 10.6% (n = 12).

Conclusions

Surveillance is the first step towards taking action to control and eliminate TB. ACES LO has a high notification rate of TB, therefore effort should be made in order to reduce TB's incidence. More investigation should be performed in order to evaluate the possibility of reintroduction of Bacille Calmette-Guérin (BCG) vaccine to the general population, instead of only risk groups, as it happens in ACES LO since 2016.

Key messages

Surveillance is one of the ten essential Public Health operations, allowing us to measure and analyse health problems in a certain population. Tuberculosis’ incidence is still high in some populations; it is a critical issue to raise awareness about.

Do long-term care services meet the minimal requirements for the elderly?

Background

As the percentage of elderly people (aged over 65) is expected to rise, from 16.0% of the population in 2010 to 29.3% in 2060 in Europe, a quality long-term care system is of increasing priority for governments. The aim of this study is to analyse long-term care services (LTCS) in the geographical area of the group of primary healthcare centres of Loures-Odivelas.

Methods

A retrospective, observational, descriptive study comprising data from public health inspections to LTCS between 2015 and 2019. Variables included were the number of residents, nurses, orderly, cooks, kitchen helpers and medical doctors; licensing status, public health inspection results and the presence of air conditioning. Descriptive analysis was performed for all variables.

Results

Between 2015 and 2019, a total of 200 public health inspections were carried out in 106 LTCS. Only 41 (38.7%) LTCS were licensed. The total number of residents was 2,803, 168 (6.0%) of which were bedridden. Concerning the staff ratio, 79 (74.5%) LTCS fulfilled the ratio of nurse to resident of 1:40 and 67 (63.2%) the ratio of orderly to resident of 1:8. On the first inspection, 11 LTCS (10.4%) complied with the minimal requirements for health care, hygiene, food preparation and facilities conditions. After the implementation of corrective measures proposed by the Public Health Unit, the number of LTCS which had complied for the same criteria was 64 (60.4%).

Conclusions

Society needs to adapt to a growing ageing population. LCTS, while part of the solution, still have deficiencies. In this sample, the majority were illegal and lacked the appropriate conditions. Public Health interventions can contribute to improving these services.

Key messages

In an ageing society, long-term care services are essential but the majority lack the appropriate conditions. Public Health intervention is crucial in implementing corrective measures that will result in better conditions for the elderly.

Structure-Antifouling Activity Relationship and Molecular Targets of Bio-Inspired(thio)xanthones

The development of alternative ecological and effective antifouling technologies is still challenging. Synthesis of nature-inspired compounds has been exploited, given the potential to assure commercial supplies of potential ecofriendly antifouling agents. In this direction, the antifouling activity of a series of nineteen synthetic small molecules, with chemical similarities with natural products, were exploited in this work. Six (4, 5, 7, 10, 15 and 17) of the tested xanthones showed in vivo activity toward the settlement of Mytilus galloprovincialis larvae (EC₅₀: 3.53–28.60 µM) and low toxicity to this macrofouling species (LC₅₀ > 500 µM and LC₅₀/EC₅₀: 17.42–141.64), and two of them (7 and 10) showed no general marine ecotoxicity (<10% of Artemia salina mortality) after 48 h of exposure. Regarding the mechanism of action in mussel larvae, the best performance compounds 4 and 5 might be acting by the inhibition of acetylcholinesterase activity (in vitro and in silico studies), while 7 and 10 showed specific targets (proteomic studies) directly related with the mussel adhesive structure (byssal threads), given by the alterations in the expression of Mytilus collagen proteins (PreCols) and proximal thread proteins (TMPs). A quantitative structure-activity relationship (QSAR) model was built with predictive capacity to enable speeding the design of new potential active compounds.

Diets supplemented with Saccharina latissima influence the expression of genes related to lipid metabolism and oxidative stress modulating rainbow trout (Oncorhynchus mykiss) fillet composition

This study aimed to evaluate the impact of diets including increasing amounts (1, 2 and 4%) of an iodine-rich macroalgae, Saccharina latissima, on gene expression and fillet composition of commercial-sized rainbow trout. Liver and muscle expression of genes related to growth, iodine, oxidative stress, and lipid metabolism, and the fillet content of fatty acids, cholesterol, and vitamin D3 were assessed. The highest kelp inclusion led to lower final body weight and HSI, without significant differences in mRNA transcription of genes involved in growth (ghr1, ghr2 and igf1) or iodine metabolism (dio1, thra, and thrb). A significant downregulation of an oxidative stress marker, gpx1b2, was observed in fish fed 2% S. latissima, which might suggest the need for less endogenous antioxidants. Dietary inclusion of kelp impacted lipid metabolism, with a downregulation of fatty acid synthase, accompanied by a general decrease of fatty acids in fillet. The present study demonstrated that supplementation of diets with 1 or 2% S. latissima can be achieved without detrimental effects on rainbow trout final weight. Evidence suggest a lipid-lowering effect of diets that did not compromise fillet EPA and DHA concentrations, being 3.7 times above the recommended levels for human consumption.

Lung function in wind instrument players of philharmonic bands

Introduction In order to play a wind instrument one must have a good breathing control with rhythm variation, control of inspiratory and expiratory volume as well as a good control of the airflow transmitted by the musician through the different mouthpieces. The pulmonary function of the different wind instrument players has been scarcely studied generating divergent conclusions.

Objectives To characterize and compare lung function and functional capacity of musicians of different wind instruments.

Methodology One hundred and one individuals from five philharmonic bands from Aveiro and Porto districts were studied. Smokers or ex-smokers for less than one year, respiratory pathology, history of chronic pulmonary or cardiac disease were exclusion criteria. The sample was divided into three groups: "Air reed", "Reeds" and "Metals". Pulmonary function was assessed by spirometry: forced vital capacity (FVC), forced expiratory volume in first second (FEV1), Tiffeneau index (TI), peak expiratory flow (PEF) and maximal voluntary ventilation (MVV). Functional capacity was assessed using the six-minute walk test (6-MWT). Data analysis was performed in the Statistical Package for the Social Sciences with a 95% confidence interval. Chi-square test, Mann-Whitney U test, ANOVA test and Kruskal-Wallis test were used.

Results All spirometric parameters with the exception of TI were increased in "Metals" group with significant decrease in the "Air reed" parameters of FEV1 (p = 0.045) and MVV (p = 0.004). A negative correlation between FEV1 and 6-MWT was noticed in male musicians (r=-0.291; p = 0.022).

Conclusion Musicians from the “Metals” group showed better lung function when compared to other groups. There was no positive correlation between lung function and functional capacity of the studied musicians. However, there was a weak negative correlation between FEV1 of male musicians and their functional capacity.

The fatty acid elongation genes elovl4a and elovl4b are present and functional in the genome of tambaqui (Colossoma macropomum)

Long-chain (C_20-24) polyunsaturated fatty acids (LC-PUFA) are physiologically important nutrients for vertebrates including fish. Previous studies have addressed the metabolism of LC-PUFA in the Amazonian teleost tambaqui (Colossoma macropomum), an emerging species in Brazilian aquaculture, showing that all the desaturase and elongase activities required to convert C₁₈ polyunsaturated fatty acids (PUFA) into LC-PUFA are present in tambaqui. Yet, elongation of very long-chain fatty acid 4 (Elovl4) proteins, which participate in the biosynthesis of very long-chain (>C₂₄) saturated fatty acids (VLC-SFA) and very long-chain polyunsaturated fatty acids (VLC-PUFA), had not been characterized in this species. Here, we investigate the repertoire and function of two Elovl4 in tambaqui. Furthermore, we present the first draft genome assembly from tambaqui, and demonstrated the usefulness of this resource in nutritional physiology studies by isolating one of the tambaqui elovl4 genes. Our results showed that, similarly to other teleost species, two elovl4 gene paralogs termed as elovl4a and elovl4b, are present in tambaqui. Tambaqui elovl4a and elovl4b have open reading frames (ORF) of 948 and 912 base pairs, encoding putative proteins of 315 and 303 amino acids, respectively. Functional characterization in yeast showed that both Elovl4 enzymes have activity toward all the PUFA substrates assayed (18:3n-3, 18:2n-6, 18:4n-3, 18:3n-6, 20:5n-3, 20:4n-6, 22:5n-3, 22:4n-6 and 22:6n-3), producing elongated products of up to C₃₆. Moreover, both Elovl4 were able to elongate 22:5n-3 to 24:5n-3, a key elongation step required for the synthesis of docosahexaenoic acid via the Sprecher pathway.

The Quantitative Proteome of the Cement and Adhesive Gland of the Pedunculate Barnacle, Pollicipes pollicipes

Adhesive secretion has a fundamental role in barnacles’ survival, keeping them in an adequate position on the substrate under a variety of hydrologic regimes. It arouses special interest for industrial applications, such as antifouling strategies, underwater industrial and surgical glues, and dental composites. This study was focused on the goose barnacle Pollicipes pollicipes adhesion system, a species that lives in the Eastern Atlantic strongly exposed intertidal rocky shores and cliffs. The protein composition of P. pollicipes cement multicomplex and cement gland was quantitatively studied using a label-free LC-MS high-throughput proteomic analysis, searched against a custom transcriptome-derived database. Overall, 11,755 peptide sequences were identified in the gland while 2880 peptide sequences were detected in the cement, clustered in 1616 and 1568 protein groups, respectively. The gland proteome was dominated by proteins of the muscle, cytoskeleton, and some uncharacterized proteins, while the cement was, for the first time, reported to be composed by nearly 50% of proteins that are not canonical cement proteins, mainly unannotated proteins, chemical cues, and protease inhibitors, among others. Bulk adhesive proteins accounted for one-third of the cement proteome, with CP52k being the most abundant. Some unannotated proteins highly expressed in the proteomes, as well as at the transcriptomic level, showed similar physicochemical properties to the known surface-coupling barnacle adhesive proteins while the function of the others remains to be discovered. New quantitative and qualitative clues are provided to understand the diversity and function of proteins in the cement of stalked barnacles, contributing to the whole adhesion model in Cirripedia.

Comparative Analysis of the Adhesive Proteins of the Adult Stalked Goose Barnacle Pollicipes pollicipes (Cirripedia: Pedunculata)

Adhesion in barnacles is still poorly understood. The cement gland secretes an insoluble multi-protein complex, which adheres very strongly to a variety of substrates in the presence of water. This adhesion mechanism is bioinspiring for the engineering of new adhesive materials, but to replicate this adhesive system, the genes coding for the cement constitutive proteins must be identified and elucidated, and their products characterised. Here, the complete sequences of three cement protein (CP) genes (CP-100K, CP-52K, and CP-19K) isolated from the cement gland of the stalked barnacle Pollicipes pollicipes (order Scalpelliformes) were obtained using RACE PCR. The three genes were compared to the 23 other acorn barnacle CP genes so far sequenced (order Sessilia) to determine common and differential patterns and molecular properties, since the adhesives of both orders have visibly different characteristics. A shotgun proteomic analysis was performed on the cement, excreted at the membranous base of specimens, where the products of the three genes sequenced in the gland were identified, validating their function as CPs. A principal component analysis (PCA) was performed, to cluster CPs into groups with similar amino acid composition. This analysis uncovered three CP groups, each characterised by similar residue composition, features in secondary structure, and some biochemical properties, including isoelectric point and residue accessibility to solvents. The similarity among proteins in each defined group was low despite comparable amino acid composition. PCA can identify putative adhesive proteins from NGS transcriptomic data regardless of their low homology. This analysis did not highlight significant differences in residue composition between homologous acorn and stalked barnacle CPs. The characteristics responsible for the structural differences between the cement of stalked and acorn barnacles are described, and the presence of nanostructures, such as repetitive homologous domains and low complexity regions, and repetitive β-sheets are discussed relatively to self-assembly and adhesion.

Using early life stages of marine animals to screen the toxicity of priority hazardous and noxious substances

This study provides toxicity values for early life stages (ELS) of two phylogenetically distinct marine animal taxa, the sea urchin (Paracentrotus lividus), a deuterostome invertebrate, and the turbot (Scophthalmus maximus), a vertebrate (teleost), when challenged by six hazardous and noxious substances (HNS): aniline, butyl acrylate, m-cresol, cyclohexylbenzene, hexane and trichloroethylene. The aim of the study was to provide preliminary information on toxic effects of representative and relevant priority HNS to assess the risk posed by spills to marine habitats and therefore improve preparedness and the response at the operational level. Selection criteria to include each compound in the study were (1) inclusion in the HASREP (2005) list; (2) presence on the priority list established by Neuparth et al. (2011); (3) paucity of toxicological data (TOXnet and ECOTOX) for marine organisms; (4) behaviour in the water according to the categories defined by the European Behaviour classification system (GESAMP 2002), by selecting compounds with different behaviours in water; and (5) physicochemical and toxicological properties, where available, in order to anticipate the most toxic compounds. Aniline and m-cresol were the most toxic compounds with no observed apical effect concentration (NOAEC) values for sea urchin ranging between 0.01 and 0.1 mg/L, followed by butyl acrylate and cyclohexylbenzene with NOAECs ranging between 0.1 and 1.0 mg/L and trichloroethylene with NOAEC values that were in the range between 1 and 10 mg/L, reflecting their behaviour in water, mostly vapour pressure, but also solubility and log Kow. Hexane was toxic only for turbot embryos, due to its neurotoxic effects, and not for sea urchin larvae, at concentrations in the range between 1 and 10 mg/L. The concentrations tested were of the same order of magnitude for both species, and it was observed that sea urchin embryos (length of the longest arm) are more sensitive than turbot eggs larvae (hatching and cumulative mortality rates) to the HNS tested (except hexane). For this specific compound, concentrations up to 70 mg/L were tested in sea urchin larvae and no effects were observed on the length of the larvae. Both tests were found to be complementary depending on behaviour in water and toxicity target of the compounds analysed.

The white mullet (Mugil curema) as biological indicator to assess environmental stress in tropical coastal lagoons

Several coastal lagoons and estuaries in Mexico receive untreated domestic and industrial discharges which contain complex mixtures of contaminants. In order to assess the effects of chemical contamination, we used the White mullet (Mugil curema) as biological indicator. We worked in two estuaries located in Northwest Mexico: Urias (highly polluted) and Teacapan (less polluted, therefore used as reference site). We measured several endpoints at different levels of biological organization: vitellogenin transcription in males as biomarker of estrogenic contamination, as well as reproductive, morphological (deformities), morphometric, and meristic parameters. Total RNA was isolated from the liver, and a partial sequence of the mullet vitellogenin gene was obtained; gene expression was analyzed by quantitative PCR. At the same time, gonad samples were analyzed by histologic techniques to determine sex ratios and the reproductive cycle stage. The reproductive season was detected from February to June in both sites, but the gonadosomatic index was consistently higher in Teacapan. Sex ratios were female-biased in both estuaries, and one intersex gonad and several malformations were found in fish from Urias. Vitellogenin gene transcription in males was detected in both sites, although gene expression was slightly higher in Urias. The results obtained in this study indicate that biological effects of contamination are evident in fish, environmental estrogens may be present in both estuaries, and the white mullet is useful as biological indicator to identify and characterize environmental stressors in tropical coastal ecosystems.

Fate, behaviour and weathering of priority HNS in the marine environment: An online tool

Literature data and data obtained with modelling tools were compiled to derive the physicochemical behaviour of 24 priority Hazardous and Noxious Substances (HNS), as a proxy to improve environmental, public health and political issues in relation to HNS spills. Parameters that rule the HNS behaviour in water and those that determine their distribution and persistence in the environment, such as fugacity, physicochemical degradation, biodegradation, bioaccumulation/biotransformation and aquatic toxicity, were selected. Data systematized and produced in the frame of the Arcopol Platform project was made available through a public database (http://www.ciimar.up.pt/hns/substances.php). This tool is expected to assist stakeholders involved in HNS spills preparedness and response, policy makers and legislators, as well as to contribute to a current picture of the scientific knowledge on the fate, behaviour, weathering and toxicity of priority HNS, being essential to support future improvements in maritime safety and coastal pollution response before, during and after spill incidents.

Electroconvulsive therapy in elderly - a preliminary study

Introduction

Studies with electroconvulsive therapy (ECT) in elderly focus mainly on the assessment of possible side effects on the cognitive functioning; there are few studies that evaluate the effectiveness.

Objective

Evaluate the effectiveness of this treatment in the population over 65 years.

Aims

Perform a preliminary study to evaluate the response to ECT of ≥ 65 years patients with depression.

Methods

We carry out a descriptive study based on patients treated in the last 10 years in the ECT Unit of Centro Hospitalar Psiquiátrico de Lisboa.

Results

Our initial sample consisted of 457 patients. We select patients aged ≥ 65 years with depression, and with complete data, including electroconvulsive parameters, and initial and final Hamilton Rating Scale for Depression (HRSD) scores (n = 59). Of this, 81.36% (n = 48) had unipolar depression, and 18.64% (n = 11) had bipolar depression. In the first group, the mean variation between the initial and final scores in HRSD was 13.88 points, and 27.10% (n = 13) of the patients ended the treatment in the normal range of HRSD score. In the second group, the mean variation was 12.82, and 63.60% (n = 7) ended the treatment in the normal range of HRSD. Considering the initial and final HRSD scores, it appears that unipolar depression group presents higher values (severe depression) (P < 0.05). When we compare the mean variation between the initial and final HRSD scores, we didn’t observe a statistically significant difference between the two groups. There was a clinical improvement in both.

Conclusions

The acute treatment with ECT appears to improve depressive symptoms in bipolar and unipolar depression, when considering an elderly population.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

The Origin and Diversity of Cpt1 Genes in Vertebrate Species

The Carnitine palmitoyltransferase I (Cpt1) gene family plays a crucial role in energy homeostasis since it is required for the occurrence of fatty acid β-oxidation in the mitochondria. The exact gene repertoire in different vertebrate lineages is variable. Presently, four genes are documented: Cpt1a, also known as Cpt1a1, Cpt1a2; Cpt1b and Cpt1c. The later is considered a mammalian innovation resulting from a gene duplication event in the ancestor of mammals, after the divergence of sauropsids. In contrast, Cpt1a2 has been found exclusively in teleosts. Here, we reassess the overall evolutionary relationships of Cpt1 genes using a combination of approaches, including the survey of the gene repertoire in basal gnathostome lineages. Through molecular phylogenetics and synteny studies, we find that Cpt1c is most likely a rapidly evolving orthologue of Cpt1a2. Thus, Cpt1c is present in other lineages such as cartilaginous fish, reptiles, amphibians and the coelacanth. We show that genome duplications (2R) and variable rates of sequence evolution contribute to the history of Cpt1 genes in vertebrates. Finally, we propose that loss of Cpt1b is the likely cause for the unusual energy metabolism of elasmobranch.

Acetylcholinesterase in Biofouling Species: Characterization and Mode of Action of Cyanobacteria-Derived Antifouling Agents

Effective and ecofriendly antifouling (AF) compounds have been arising from naturally produced chemicals. The objective of this study is to use cyanobacteria-derived agents to investigate the role of acetylcholinesterase (AChE) activity as an effect and/or mode of action of promising AF compounds, since AChE inhibitors were found to inhibit invertebrate larval settlement. To pursue this objective, in vitro quantification of AChE activity under the effect of several cyanobacterial strain extracts as potential AF agents was performed along with in vivo AF (anti-settlement) screening tests. Pre-characterization of different cholinesterases (ChEs) forms present in selected tissues of important biofouling species was performed to confirm the predominance of AChE, and an in vitro AF test using pure AChE activity was developed. Eighteen cyanobacteria strains were tested as source of potential AF and AChE inhibitor agents. Results showed effectiveness in selecting promising eco-friendly AF agents, allowing the understanding of the AF biochemical mode of action induced by different compounds. This study also highlights the potential of cyanobacteria as source of AF agents towards invertebrate macrofouling species.

Tophaceous Gout: a tragic course for a preventable disease

A 66-year-old man, with a history of chronic tophaceous gout since the age of 30, presented with multiple tophi and significant deformity of all fingers that caused substantial function loss. Due to osteomyelitis refractory to antimicrobial therapy, he underwent disarticulation of several fingers. Finally, both his hands were amputated.

Baastrup's Disease: a poorly recognised cause of back pain

A 56-year-old male complained about progressive mechanical back pain for more than 10 years, which worsened with prolonged orthostatism and spine extension and improved in fetal position. His lumbar spine radiography revealed enlargement and sclerosis of the spinous processes which was confirmed by computed tomography, suggesting Baastrup's disease. This condition is characterized by enlargement, close approximation and impingement of one spinous process on another ("kissing spines"). There are few studies on Baastrup´s disease epidemiology and their results are inconsistent. Patients often complain of back pain, typically increased with extension and relieved by flexion. Radiographically, spinous process impingement leads to reactive sclerosis, enlargement, flattening, and remodeling of the involved vertebral spines. Physicians frequently miss it on radiographs due to lack of knowledge and overexposure of spinous processes in most X rays. Both conservative and surgical options are available for treatment. Baastrup's disease should be considered in differential diagnosis of back pain, although one must be aware the typical radiographic changes appear to be common with aging and may not be the cause of patient's symptoms.

Effects of the PPARα agonist WY-14,643 on plasma lipids, enzymatic activities and mRNA expression of lipid metabolism genes in a marine flatfish, Scophthalmus maximus

Fibrates and other lipid regulator drugs are widespread in the aquatic environment including estuaries and coastal zones, but little is known on their chronic effects on non-target organisms as marine fish. In the present study, turbot juveniles were exposed to the PPARα model agonist WY-14,643 for 21 days by repeated injections at the concentrations of 5mg/kg (lo-WY) and 50mg/kg (hi-WY), and samples taken after 7 and 21 days. Enzyme activity and mRNA expression of palmitoyl-CoA oxidase and catalase in the liver were analyzed as first response, which validated the experiment by demonstrating interactions with the peroxisomal fatty acid oxidation and oxidative stress pathways in the hi-WY treatment. In order to get mechanistic insights, alterations of plasma lipids (free cholesterol, FC; HDL associated cholesterol, C-HDL; triglycerides, TG; non-esterified fatty acids, NEFA) and hepatic mRNA expression of 17 genes involved in fatty acid and lipid metabolism were studied. The exposure to hi-WY reduced the quantity of plasma FC, C-HDL, and NEFA. Microsomal triglyceride transfer protein and apolipoprotein E mRNA expression were higher in hi-WY, and indicated an increased formation of VLDL particles and energy mobilization from liver. It is speculated that energy depletion by PPARα agonists may contribute to a higher susceptibility to environmental stressors.

Ecological modelling and toxicity data coupled to assess population recovery of marine amphipod Gammarus locusta: Application to disturbance by chronic exposure to aniline

A population agent-based model of marine amphipod Gammarus locusta was designed and implemented as a basis for ecological risk assessment of chemical pollutants impairing life-history traits at the individual level. We further used the model to assess the toxic effects of aniline (a priority hazardous and noxious substance, HNS) on amphipod populations using empirically-built dose-response functions derived from a chronic bioassay that we previously performed with this species. We observed a significant toxicant-induced mortality and adverse effects in reproductive performance (reduction of newborn production) in G. locusta at the individual level. Coupling the population model with the toxicological data from the chronic bioassay allowed the projection of the ecological costs associated with exposure to aniline that might occur in wild populations. Model simulations with different scenarios indicated that even low level prolonged exposure to the HNS aniline can have significant long-term impacts on G. locusta population abundance, until the impacted population returns to undisturbed levels. This approach may be a useful complement in ecotoxicological studies of chemical pollution to transfer individual-collected data to ecological-relevant levels.

Review on hazardous and noxious substances (HNS) involved in marine spill incidents—an online database

In this review, we have collected information on the behavior, fate, weathering, and impact of hazardous and noxious substances (HNS) accidentally spilled at sea on the marine biota. The information was compiled on a datasheet and converted into a database that can be accessed by the general public (www.ciimar.up.pt/hns). Systematization of data is important to assist stakeholders involved in HNS spill preparedness and response, facilitating the incorporation of lessons from past incidents in the decision process. The database contains 184 entries of HNS spilled in 119 incidents in marine waters around the world. Data were analyzed in terms of HNS physical behavior in water according to SEBC (Standard European Behavior Classification) codes. The most common products involved in accidental spills in the marine environment were identified and major lessons highlighted. From the analysis, it was determined that most HNS spills were poorly documented and information was mistreated. In most cases, no monitoring programs were implemented following the incident. This conduct has occurred in 24 out of 119 incidents analyzed and has consequently limited the information on fate, behavior, and weathering of HNS spilled that could have been recovered. Major gaps were identified, and priorities and recommendations were drawn as a step toward improving preparedness and response to HNS spills.

[Psoriatic Arthritis concomitant with Paget's Disease - a case report]

Paget disease of bone is a focal disorder of bone metabolism; it is characterized by an accelerated rate of bone remodeling, with profound changes in the bone structure, making it fragile. This condition affects approximately 2% to 5% of the population older than 40. The main clinical manifestations of Paget's disease are pain and bone deformity, although the majority of patients are asymptomatic. Psoriatic Arthritis is a spondyloarthritis with a prevalence of about 0,1%. It is characterized by the presence of arthritis, enthesitis and/or dactylitis associated with a familiar or personal history of psoriasis. Several clinical patterns of joint involvement in psoriatic arthritis have been identified, namely, the polyarticular pattern, similar to rheumatoid arthritis. Arthritis precedes skin disease in approximately 13 to 17 % of the cases. The authors report a clinical case of a 60 years old patient with polyarthritis and dactylitis who was diagnosed with psoriatic arthritis and Paget's disease of bone. The concomitance of the two entities, in the same individual, with so different pathogenesis and clinical features, have never been described on literature. Because of the complexity on the clinical and imaging evaluation as the result of the coexistence of both pathologies, the authors consider relevant to publish this singular case.

Sexuality in spondyloarthritis--the impact of the disease

INTRODUCTION

The impact of rheumatic diseases on patients' sexual life has been gathering the attention of the scientific community over the last decade. The existing studies are scarce, especially related to spondyloarthritis, and particularly to psoriatic arthritis. Several factors associated with the disease may condition sexual function: pain, stiffness, decreased range of motion, joint swelling and extraarticular features such as fatigue, enthesopathy and cutaneous lesions in psoriatic arthritis.

OBJECTIVES

To assess sexual satisfaction and limitations in sexual activity in a cohort of patients with spondyloarthritis.

METHODS

An anonymous questionnaire was performed, consisting in two parts. One part consisted in a questionnaire filled by the doctor with data on the disease; the other part was filled by the patient, with demographic data, multiple choice questions and questions to be answered through a visual analogic scale, including items approached in some validated indexes of sexual function and satisfaction assessment. Statistical treatment was performed using SPPS system, version 17.0.

RESULTS

76 patients with the diagnosis of spondyloarthritis were enrolled; 31 had psoriatic arthritis, 30 had ankylosing spondylitis, 9 had undifferentiated spondyloarthritis and 6 had inflammatory bowel disease spondyloarthritis. In a visual analogic scale, the perception of conditioning in the conjugal relationship was 33.68±31.56 mm; limitation on sexual activity was 32.72±31.06 mm; limitation imposed by pain, joint swelling, fatigue, stiffness, decreased range of motion, decreased libido and cutaneous lesions ranged from 29.17±28.51 mm (swelling) to 46.94±32.31 mm (fatigue); there was no significant difference between sexes, diagnose and type of involvement. A strong correlation was identified between some analysed factors and ASQoL and HAQ values, but only moderate between them and disease function and activity indexes. Most of patients did not talk about their sexual limitations with their partners or with health professionals.

CONCLUSION

This work highlights the impact of spondyloarthritis on patients' sexual function. The type of disease and joint involvement didn't imply statistically significant differences on the analyzed parameters in this cohort. This work also emphasizes the unawareness of health professionals towards this subject, whose approach is equally difficult to the patients, and might deserve greater attention.

Management of contaminated marine marketable resources after oil and HNS spills in Europe

Different risk evaluation approaches have been used to face oil and hazardous and noxious substances (HNS) spills all over the world. To minimize health risks and mitigate economic losses due to a long term ban on the sale of sea products after a spill, it is essential to preemptively set risk evaluation criteria and standard methodologies based on previous experience and appropriate scientifically sound criteria. Standard methodologies are analyzed and proposed in order to improve the definition of criteria for reintegrating previously contaminated marine marketable resources into the commercialization chain in Europe. The criteria used in former spills for the closing of and lifting of bans on fisheries and harvesting are analyzed. European legislation was identified regarding food sampling, food chemical analysis and maximum levels of contaminants allowed in seafood, which ought to be incorporated in the standard methodologies for the evaluation of the decision criteria defined for oil and HNS spills in Europe. A decision flowchart is proposed that opens the current decision criteria to new material that may be incorporated in the decision process. Decision criteria are discussed and compared among countries and incidents. An a priori definition of risk criteria and an elaboration of action plans are proposed to speed up actions that will lead to prompt final decisions. These decisions, based on the best available scientific data and conducing to lift or ban economic activity, will tend to be better understood and respected by citizens.

Diversity and history of the long-chain acyl-CoA synthetase (Acsl) gene family in vertebrates

BACKGROUND

Fatty acids, a considerable fraction of lipid molecules, participate in fundamental physiological processes. They undergo activation into their corresponding CoA esters for oxidation or esterification into complex lipids (e.g. triglycerides, phospholipids and cholesterol esters), a process that is carried out by acyl-CoA synthases (ACS). Here we analyze the evolution of the gene family encoding for the long-chain acyl-CoA synthetases (Acsl) in vertebrates.

RESULTS

By means of phylogenetics and comparative genomics we show that genome duplications (2R) generated the diversity of Acsl genes in extant vertebrate lineages. In the vertebrate ancestor two separate genes originated the current Acsl1/5/6 and the Acsl3/4 gene families, and the extra gene duplicates in teleosts are a consequence of the teleost specific third round of genome duplication (3R). Moreover, the diversity of Acsl family members is broader than anticipated. Our strategy uncovered a novel uncharacterized Acsl-like gene found in teleosts, spotted gar, coelacanth and possibly lamprey, which we designate Acsl2. The detailed analysis of the Acsl2 teleost gene locus strongly supports the conclusion that it corresponds to a retained 2R paralogue, lost in tetrapods.

CONCLUSIONS

We provide here the first evolutionary analysis of the Acsl gene family in vertebrates, showing the specific contribution of 2R/3R to the diversity of this gene family. We find also that the division of ACSL enzymes into two groups predates at least the emergence of deuterostomes. Our study indicates that genome duplications significantly contributed to the elaboration of fatty acid activation metabolism in vertebrates.

Tissue expression of PPAR-α isoforms in Scophthalmus maximus and transcriptional response of target genes in the heart after exposure to WY-14643

Peroxisome proliferator-activated receptors (PPARs) are involved in the regulation of lipid and carbohydrate metabolism and can be activated either by natural ligands as fatty acids or by synthetic ligands including several environmental chemicals. In this study, two PPARα isoforms (α1 and α2) were analyzed in turbot (Scophthalmus maximus) for a different tissue distribution. PPARα1 was ubiquitously expressed, while the PPARα2 was predominantly expressed in the heart. Following this result, turbot juveniles were exposed by injection to a synthetic selective PPARα agonist, WY-14643, for 14 days. Suppression subtractive hybridization (SSH) was performed with pools of heart samples of control and exposed fish to get insights into PPARα-regulated genes in the heart of juvenile turbot. Four genes were positively identified in the forward-subtracted and 12 genes in the reverse-subtracted cDNA SSH library, corresponding to the down-regulated and up-regulated genes in response to the WY-14643 treatment, respectively. The confirmation of these results in individual samples of juvenile turbot exposed to WY-14643 revealed a statistically significant mRNA induction of two cardiac muscle proteins (myosin light chain 2 and tropomyosin 4), which were shown to be involved in heart contraction and heartbeat regulation in other teleost species. Herewith, we showed for the first time that PPARα2 is predominantly expressed in the heart and that a PPARα agonist can induce the mRNA expression of cardiac muscle proteins in teleosts.

Normalization strategies for gene expression studies by real-time PCR in a marine fish species, Scophthalmus maximus

Thorough evaluation of normalization approaches is a fundamental aspect in real-time quantitative RT-PCR experiments to avoid artificial introduced intergroup variations. In our study, we tested three normalization strategies in an experimental data set derived from a toxicological exposure of Scophthalmus maximus to the peroxisome proliferator-activated receptor alpha (PPARα) agonist WY-14643. Juvenile turbots were exposed by repeated injections to 5 mg or 50 mg WY-14643/kg, and liver samples were taken at day 1, 7 and 21. Specifically, the mRNA expression of peroxiredoxin 5 (prdx5) was normalized to the cDNA content, to the mRNA expression of single reference genes (b-actin, b-act; elongation factor 1 α, ef1a; glyceraldehyde-3-phosphate dehydrogenase, gapdh; ribosomal protein L8, rpl8; tata-box binding protein, tbp; tubulin beta 2C chain, tubb2c; ubiquitin-conjugating enzyme E2L 3, ub2l3) or to a combination of multiple reference genes using geNorm, BestKeeper or NormFinder algorithms. Four single reference genes (ef1a, rpl8, tubb2c, tbp) did not show any significant differences between the treatment groups over time, while significant intergroup variations were observed for cDNA content, gapdh, b-act and ub2l3. The normalization of prdx5 to the valid (not altered) single reference genes led to significant up-regulated (prdx5/rpl8), not-regulated (prdx5/ef1a; prdx5/tbp) or down-regulated (prdx5/tubb2c) mRNA expression pattern. The multiple reference gene approaches resulted in different rankings and combinations of the most stable expressed reference genes (geNorm: ef1a>rpl8>b-act; BestKeeper: ub2l3>gapdh>ef1a; NormFinder: b-act>ef1a). However, the normalization with the three multiple reference gene procedures demonstrated consistent expression pattern with a significant up-regulation of prdx5 in response to the higher concentration after 21 days. Concluding, even if not yet established as "gold" standard for expression profiling in environmental toxicology or physiology using freshwater or marine fish models, the multiple reference gene approach is recommended, since it eliminates any biased results, which represented the major flaw of single reference genes.

Dynamics of PPARs, fatty acid metabolism genes and lipid classes in eggs and early larvae of a teleost

Dietary long chain polyunsaturated fatty acids (FA) have been recognized of crucial importance in early development of vertebrates, contributing to the impressive morphological and physiological changes both as building blocks and to energy production. The importance of lipids along development depends on ontogenetic, phylogenetic and environmental parameters. The expression patterns of FA metabolism genes have not been characterized in developing fish embryos nor compared to lipid class profiles. Full lipid metabolism only occurred after hatching, as revealed by alterations in lipid profiles and FA gene expression. Nonetheless, transcriptional changes of some FA genes were already present in embryos at notochord formation. Many genes displayed an expression profile opposed to the decrease of lipids along the development, while others responded solely to starvation. Transcription of most genes involved in FA metabolism had a strong correlation to PPARs' mRNA levels (α1, α2, β, γ). The comparison of mRNA expression of the genes with the lipid profiles produced new insights into the FA metabolism and regulation during the development of turbot larvae, providing the basis for future studies including comparative approaches with other vertebrate species.

Experimental and modeling analysis of Synechocystis sp. PCC 6803 growth

BACKGROUND/AIMS

The influence of different parameters such as temperature, irradiance, nitrate concentration, pH, and an external carbon source on Synechocystis PCC 6803 growth was evaluated.

METHODS

4.5-ml cuvettes containing 2 ml of culture, a high-throughput system equivalent to batch cultures, were used with gas exchange ensured by the use of a Parafilm™ cover. The effect of the different variables on maximum growth was assessed by a multi-way statistical analysis.

RESULTS

Temperature and pH were identified as the key factors. It was observed that Synechocystis cells have a strong influence on the external pH. The optimal growth temperature was 33°C while light-saturating conditions were reached at 40 µE·m⁻²·s⁻¹.

CONCLUSION

It was demonstrated that Synechocystis exhibits a marked difference in behavior between autotrophic and glucose-based mixotrophic conditions, and that nitrate concentrations did not have a significant influence, probably due to endogenous nitrogen reserves. Furthermore, a dynamic metabolic model of Synechocystis photosynthesis was developed to gain insights on the underlying mechanism enabling this cyanobacterium to control the levels of external pH. The model showed a coupled effect between the increase of the pH and ATP production which in turn allows a higher carbon fixation rate.