Acetylcholinesterase activity in muscle tissue of Norway lobster Nephrops norvegicus: Importance of body size, season, sex and naturally occurring metals.

The aim of the present study was to determine the levels of acetylcholinesterase (AChE) activity in the tail muscle tissue of wild populations of Nephrops norvegicus from the Northern Adriatic, and correlate it to body size, seasons, sex and the content of mercury, arsenic, cadmium, lead and copper. The animals of both sexes were collected in spring and autumn from two relatively distant fishing grounds. A marked variability of muscle AChE activity was found (0.49 to 11.22 nmol/min/mg prot.), displaying the opposite seasonal trend between two sampling sites. Small, but significant negative correlation has been found between AChE activity and carapace length (rs = - 0.35, p < 0.05). Data reported here provide an essential baseline for future studies of neurotoxicity in crustaceans. The study highlights the necessity for continuous monitoring of potentially toxic metals in edible marine species to avoid possible repercussions of seafood consumption on human health.

Arsenic (As), copper (Cu), zinc (Zn) and selenium (Se) in northwest Croatian seafood: A health risks assessment.

This study focuses on the health risk assessment of arsenic (As), copper (Cu), zinc (Zn), and selenium (Se) concentrations in seafood species commonly consumed in the northwestern region of Croatia. By measuring the concentrations of these elements coupled with data on seafood consumption, the health risks were evaluated using Target Hazard Quotients and Hazard Indexes. The results indicate a slightly increased health risks linked to seafood consumption for As, Cu and Zn in some of the tested seafood species. The findings of this study highlight the critical need for stronger food quality control measures, especially targeting certain types of seafood.

Atmospheric parameters play an important role in driving hydrogen sulphide concentrations in ambient air near waste management centres.

Emissions of odorous compounds are major contributors to public opposition when siting waste management facilities. Thus, it is essential to understand how to minimise the concentration of odour-causing chemicals in ambient air surrounding such facilities. Although the concentration of pollutants in the atmosphere is a function of meteorology, there is limited data on the atmospheric parameters that drive ambient air concentrations of odour-causing substances in settlements near waste management facilities. Here, we analysed how temperature, wind direction, wind speed, atmospheric pressure and humidity impact the concentrations of hydrogen sulphide (H2S) in the ambient air, a potentially toxic chemical and a chief contributor to noxious odours. The relative contribution of each variable was assessed using multivariate statistical analysis applied to an extensive data set of over 7,000 data points collected during 2021. Our results show that all tested atmospheric parameters significantly affected H2S concentrations in ambient air. Wind direction had the greatest impact on H2S concentrations, followed by temperature, humidity, atmospheric pressure and wind speed. Specifically, the concentration of H2S was positively correlated with humidity and atmospheric pressure and had a U-shaped correlation with temperature. Atmospheric variables were able to explain 15% of variation in H2S concentrations (R2 = 15%), indicating the presence of other factors affecting H2S ambient air concentrations. Our study shows that proper consideration of atmospheric parameters, especially wind direction and temperatures, is of uttermost importance when siting waste management facilities. The conclusions are broadly applicable to odorous compounds near waste management facilities, so adverse effects to human health and the environment can be minimised.

Exploring the link between sulphur-containing compounds and noxious odours at waste management facilities: implications for odour monitoring and mitigation strategies.

With this study we challenge the widely held assumption that sulphur-containing compounds in ambient air are good indicators of the presence noxious odours near waste management facilities. We analysed an extensive set of olfactometric data and data on the concentrations of hydrogen sulphide and trace sulphur compounds (TSCs) near a waste management facility in Croatia in 2021. The results show that the presence of noxious odours significantly correlates only with the concentrations of hydrogen sulphide and methyl mercaptan in ambient air but not with other measured TSCs. Thus, in addition to the measurement of pollutants in ambient air, Integrated Pollution and Prevention Control (IPPC) permits should mandate olfactometric measurements to detect and mitigate noxious odours near waste management facilities.

Assessment of health risks associated with heavy metal concentration in seafood from North-Western Croatia.

The following study aims at assessing the health risks associated with the consumption of the most commonly consumed seafood in the north-western part of Croatia due to the presence of heavy metals. Samples of seafood were collected and analysed for lead (Pb), cadmium (Cd), and mercury (Hg) content. Analyses of Cd and Pb were carried out by inductively coupled plasma mass spectrometry (ICP-MS) whereas Hg content was measured using atomic absorption spectrometry (AAS). Metal concentrations were in the following order Hg > Pb > Cd for the gilthead seabream, European hake, sardines, and tuna fish whereas in the Patagonian squid cadmium (Cd) was the heavy metal with the highest concentration, with the order of other metals being Cd > Hg > Pb. The heavy metal concentrations have been used to address the health risks using the Estimated Weekly Intake (EWI), Target Hazard Quotients (THQ), and Hazard Indices (HI). The findings revealed that the concentrations of the tested heavy metals, expressed on a per wet weight basis, did not exceed the Maximum Residue Levels (MRL) for those compounds mandated by national Croatian legislation. However, the HI for Hg was above 1, indicating a risk of adverse health effects due to the presence of this heavy metal in the consumed seafood. We conclude that the consumption of certain type of seafood such as the tuna fish should be limited when sensitive segments of the population such as children, elderly and pregnant women are concerned. Our results strongly advocate for a more stringent seafood quality control in the region.

Model of calculating a composite environmental index for assessing the impact of port processes on environment: a case study of container terminal.

Environmental standards are not harmonized in ports and neither are the instruments used for the assessing the condition of environmental efficiency of a port system. The purpose of the research conducted in the framework of this paper is to propose the methodology for calculating the Port Environmental Index (IE) which synthesizes all environmental aspects of port operations into a single value. The goals of the paper were the following: (1) to integrate the relevant environmental aspects of port activities and evaluate the impact of port terminal processes on the environment by calculating the IE and (2) to validate the index by applying it to a container terminal in the north-western part of Croatia. IE was constructed using the compound index method where compilation and aggregation of individual indicators were used to form a compound index of the overall effect of port processes on the environment. The validation of IE by applying it to a container terminal (Port of Rijeka, north-western part of Croatia) showed that the IE can be easily applied and its application allows monitoring the overall changes in environmental performance of port areas. In addition, IE can be used to test different pollution abatement strategies including testing interventions in the port processes and determining their share in the overall impact on the environment. In addition, the potential constraints to using such an approach are discussed in the paper.

Management of municipal solid waste in Croatia: Analysis of current practices with performance benchmarking against other European Union member states.

The European Commission has adopted a very ambitious circular economy package and has consequently revised many legislative proposals on waste. The new targets include achieving a recycling rate of 65% by 2030 and imposing a cap on landfilled waste to no more than 10% (as a percentage of weight). Using available European and national databases on municipal solid waste indicators, we have analysed municipal solid waste production trends for Croatia and have benchmarked the indicators against other EU member states and EU averages. Our analysis points out that the production of municipal solid waste has steadily risen over the last two decades. Although Croatia produces a relatively low amount of municipal solid waste compared with other EU countries and EU averages, gross domestic product adjusted waste production reveals that for every euro of gross domestic product Croatia produces substantial amounts of municipal solid waste. As a matter of fact, among all the EU member states, only Bulgaria had a worse performance than Croatia. Regarding recycling rates, Croatia recycles 15% of its municipal solid waste and incinerates approximately 3% (by weight). The rest (82% by weight) is currently being landfilled. Regarding the treatment of waste, Croatia has implemented mechanical-biological treatment technology, but our analysis reveals that the initial number of mechanical-biological treatment plants will likely have to be scaled down taking into consideration the new EU waste management targets.

A baseline study of the metallothioneins content in digestive gland of the Norway lobster Nephrops norvegicus from Northern Adriatic Sea: Body size, season, gender and metal specific variability.

Metallothioneins content was investigated in digestive gland of two wild-caught Norway lobster Nephrops norvegicus populations from the Northern Adriatic Sea, in relation to body size, season and gender. Concomitant accumulation of cadmium, mercury, arsenic, lead, chromium and manganese, reactive oxygen species concentration and energy reserves in digestive gland were also assessed. While differences between genders were not recorded, metallothioneins content seasonal trends were affected by body size. Most of parameters displayed inconsistent trends across sampling sites. Significant correlation between metallothioneins content and cadmium, arsenic and mercury concentrations was recorded only for larger lobsters. A negative correlation of reactive oxygen species concentration and metallothioneins content was observed for small, but not large lobsters. Energy reserves, in particular lipids, could considerably influence biochemical and chemical parameters variations. The present results constitute the essential baseline for future studies aimed at evaluating the N. norvegicus health in relation to metal contamination of coastal sediments.

Ungual fibroma in 12-year-old boy with hypomelanotic macules, intellectual disability and attention deficit hyperactivity disorder-possible tuberous sclerosis.

OBJECTIVE: To report a case of a 12-year-old boy with intellectual disability and attention deficit hyperactivity disorder, who came to surgery for an examination due to a minor bulge on the left thumb, which had been growing for the previous month. His mother denied any trauma. METHODS: After the removal of the clinically ambiguous bulge and a pathohistological confirmation that it was a periungual fibroma, complete patient analysis was performed due to the presence of hypomelanotic macules and a suspected tuberous sclerosis. RESULTS: Considering the presence of hypomelanotic macules, as one of the main criteria, possible TS diagnosis was set. CONCLUSION: Early detection of the symptoms of TS enables a timely provision of protocols for further patient monitoring, which affects the patient's morbidity and mortality.

Historical trends (1998-2012) of nickel (Ni), copper (Cu) and chromium (Cr) concentrations in marine sediments at four locations in the Northern Adriatic Sea.

Historical trends (1998-2012) nickel (Ni), copper (Cu) and chromium (Cr) concentrations in marine sediments were assessed at four locations in the Northern Adriatic Sea (Croatia) in the proximity of an oil refinery. Ecological risks were characterized by benchmarking the dataset against Sediment Quality Guidelines (SQG). A significant number of samples had Ni values above ERL with no exceedance of the ERL values for Cu and Cr. Weak positive historical trends were found for only for Cu. At all sites there were statistically significant correlations between Ni and Cr indicating a common origin of these heavy metals in the investigated marine sediments. There were statistically significant differences between the sites under the direct influence of the oil refinery compared to the control site indicating the possibility that the oil refinery is contributing to the concentration of these heavy metals in the marine sediments.

The specific NK cell response in concert with perforin prevents CD8(+) T cell-mediated immunopathology after mouse cytomegalovirus infection.

Natural killer (NK) and CD8(+) T cells play a crucial role in the control of mouse cytomegalovirus (MCMV) infection. These effector cells exert their functions by releasing antiviral cytokines and by cytolytic mechanisms including perforin activation. In addition to their role in virus control, NK cells play an immunoregulatory role since they shape the CD8(+) T cell response to MCMV. To investigate the role of perforin-dependent cytolytic mechanism in NK cell modulation of CD8(+) T cell response during acute MCMV infection, we have used perforin-deficient C57BL/6 mice (Prf1(-/-)) and have shown that virus control by CD8(+) T cells in Prf1(-/-) mice is more efficient if NK cells are activated by the engagement of the Ly49H receptor with the m157 MCMV protein. A lack of perforin results in severe liver inflammation after MCMV infection, which is characterized by immunopathological lesions that are more pronounced in Prf1(-/-) mice infected with virus unable to activate NK cells. This immunopathology is caused by an abundant infiltration of activated CD8(+) T cells. The depletion of CD8(+) T cells has markedly reduced pathohistological lesions in the liver and improved the survival of Prf1(-/-) mice in spite of an increased viral load. Altogether, the results of our study suggest that a lack of perforin and absence of the specific activation of NK cells during acute MCMV infection lead to an unleashed CD8(+) T cell response that is detrimental for the host.

Sources, trends and ecotoxicological risks of PAH pollution in surface sediments from the northern Adriatic Sea (Croatia).

In this study, the levels, sources and historical trends (2007-2012) of PAH pollution in surface sediments in the northern Adriatic Sea (Croatia) have been assessed. In addition, ecotoxicological risks have been estimated by evaluating the PAH dataset against Sediment Quality Guidelines (SQGs). The results indicate that PAH in surface sediments are of pyrolitic origin with no clear positive or negative trend in PAH concentration over the investigated period. Evaluations against SQG and mSQGq indicate that surface sediments at all sampling sites have a low to medium ecotoxicological risk. In order to improve trend analysis and characterization of PAH pollution in surface sediments in this region an increase in spatial resolution of sampling points is recommended.

The responses of the hepatosomatic index (HSI), 7-ethoxyresorufin-O-deethylase (EROD) activity and glutathione-S-transferase (GST) activity in sea bass (Dicentrarchus labrax, Linnaeus 1758) caged at a polluted site: implications for their use in environmental risk assessment.

The present study investigates the response of three hepatic biomarkers in adult sea bass (Dicentrarchus labrax, Linnaeus 1758) caged at a wastewater outlet of an oil refinery with fish caged at a pristine site used as controls. The biomarkers that were investigated were the hepatosomatic index (HSI), 7-ethoxyresorufin-O-deethylase (EROD) activity and glutathione-S-transferase (GST) activity. In addition, we have measured the levels of polycyclic aromatic hydrocarbons (PAHs) and selected heavy metals (lead, cadmium, mercury, copper and zinc) in sediment samples at the polluted site. Although the polluted site had high environmental levels of PAHs and heavy metals, there was no difference in hepatic EROD activity and HSI between fish caged at the polluted site and controls. On the other hand, GST activity was significantly lower in fish caged at the polluted site compared to controls. Our results point out that the studied biomarkers have limited use in environmental risk assessment studies, at least when caged adult sea bass is used as the sentinel species and complex toxicant mixtures are involved.

Innate immunity regulates adaptive immune response: lessons learned from studying the interplay between NK and CD8+ T cells during MCMV infection.

Natural killer (NK) cells play a crucial role in early immune response against cytomegalovirus infection. A large and mounting body of data indicate that these cells are involved in the regulation of the adaptive immune response as well. By using mouse cytomegalovirus (MCMV) as a model, several groups provided novel insights into the role of NK cells in the development and kinetics of antiviral CD8(+) T cell response. Depending on infection conditions, virus strain and the genetic background of mice used, NK cells are either positive or negative regulators of the CD8(+) T cell response. At present, there is no unique explanation for the observed differences between various experimental systems used. In this review we discuss the mechanisms involved in the interplay between NK and CD8(+) T cells in the early control of MCMV infection.

Aporrectodea caliginosa, a suitable earthworm species for field based genotoxicity assessment?

There is a growing interest for the application of biomakers to field-collected earthworms. Therefore we have evaluated the usability of native populations of endogeic, widely distributed earthworm Aporrectodea caliginosa in the assessment of soil genotoxicity using the Comet assay. Validation of the Comet assay on earthworm coelomocytes has been established using commercially available Eisenia fetida exposed to copper, cadmium, and pentachlorophenol, along with A. caliginosa exposed to copper in a filter paper contact test. Neutral red retention time (NRRT) assay was conducted on copper exposed and field-collected earthworms. Significant DNA and lysosomal damage was measured using Comet and NRRT assays in native populations of A. caliginosa sampled from the polluted soils in the urban area in comparison to the earthworms from the reference site. The results of this study confirm the employment of A. caliginosa as a suitable species for the in situ soil toxicity and genotoxicity field surveys.

Genotoxicity of marine sediments in the fish hepatoma cell line PLHC-1 as assessed by the Comet assay.

The main goal of this study was to test the usefulness of the Comet assay in the PLHC-1 hepatoma fish cell line as a tool for detecting the presence of genotoxic compounds in contaminated marine sediments. The system has been tested using both model chemicals (benzo[a]pyrene (B[a]P) and ethyl methanesulfonate (EMS)) and extracts of sediment samples obtained with solvent dichloromethane/methanol. For all of the analysed sediment extracts as well as for the model chemicals a concentration dependent genotoxic effect was observed. The sediment with the highest observed genotoxic potential was additionally extracted using various solvents in order to test which class of compounds, according to their polarity, is most responsible for the observed genotoxic effect. Non-polar solvents (cyclohexane and dichloromethane) yielded stronger genotoxic effect but the highest level of DNA damage was determined after exposure to sediment extract obtained with the solvent mixture dichloromethane/methanol which extracts a wide range of contaminants. Our results indicate that the PLHC-1 cell line is a suitable in vitro model in sediment genotoxicity assessment and encourage the use of fish cell lines as versatile tools in ecogenotoxicology.

CYP1A induction potential and the concentration of priority pollutants in marine sediment samples--in vitro evaluation using the PLHC-1 fish hepatoma cell line.

The use of in vitro biotests in combination with chemical determination of priority pollutants is considered a promising approach in environmental risk assessment. The main goal of this study was to evaluate the relationship between the CYP1A induction potential and the concentration of priority pollutants (PAHs, PCBs and heavy metals) in contaminated marine sediments. Six sediment samples characterized by different types of pollution were collected from the Bay of Kvarner, Croatia. CYP1A induction potency was determined in vitro by the measurement of ethoxyresorufin-O-deethylase (EROD) activity in PLHC-1 fish hepatoma cells. The results were compared to the potency of the model CYP1A inducer 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and expressed in 2,3,7,8-TCDD equivalents. All of the tested sediment samples were able to induce CYP1A activity in a dose-dependent manner. On a general scale, there was a good correlation between CYP1A induction and the concentration of priority pollutants in the tested samples. However, some samples, which had relatively low levels of priority pollutants, exhibited a strong CYP1A induction response. Therefore, apart from the confirmed usability and sensitivity of the EROD determination in the PLHC-1 cells as a suitable in vitro model in ecotoxicology, the results of this study indicate that the list of priority pollutants usually determined in the attempt to evaluate the risk of adverse effects to marine wildlife should be reconsidered.

Murine cytomegalovirus regulation of NKG2D ligands.

Human cytomegalovirus (HCMV) is a ubiquitous pathogen that causes morbidity risk in immunologically suppressed and immunodeficient patients including congenital infections. Approaches to curb the consequences of HCMV infections are restricted by a lack of complete understanding of viral pathogenesis. The infection of mice with murine cytomegalovirus (MCMV) as a model of HCMV infection has been particularly useful in elucidating the role of innate and adaptive immune response mechanisms. A large number of cytomegalovirus genes modulate the innate and the adaptive host immune response. The products of several MCMV genes are involved in subverting the natural killer (NK) cell response by down-modulating cellular ligands for the NKG2D receptor expressed on NK cells and CD8(+) T cells. Mutant viruses lacking these immunoevasion genes are attenuated with respect to virus growth in vivo. Given the importance of the NKG2D receptor in controlling both NK- and T cell-mediated immunity, it is of tremendous importance to understand the molecular mechanisms and consequences of viral regulation of the NKG2D ligands.