Acute toxicity of triclosan, caffeine, nanoplastics, microplastics, and their mixtures on Daphnia magna.

We measured acute toxicity of triclosan, caffeine, nanoplastics, and microplastics, and their mixtures on Daphnia magna. Limitations of this study included use of a single species, acute rather than chronic toxicity testing, examination of single substances and their mixtures, and laboratory conditions that may not reflect real-world scenarios. Single compound toxicity results revealed a clear concentration-response pattern, with triclosan showing higher toxicity than caffeine, and nanoplastics displaying higher toxicity than microplastics. Combinations of triclosan with nanoplastics, and microplastics resulted in varying mortality rates, with higher rates observed with increased concentrations of triclosan and nanoplastics. Similar results were observed with caffeine, nanoplastics, and microplastics mixtures. These findings underline potential hazards posed by these pollutants to marine ecosystems and highlight the need for further studies to understand chronic effects, interactive effects of multiple substances, and the impact under more environmentally relevant conditions.

Telomerase Activity in Androgenetic Rainbow Trout with Growth Deficiency and in Normally Developed Individuals.

Role of telomerase in specimens with retarded growth (dwarfs) has not been thoroughly examined to date. Considering that some of the fish species show correlation between somatic growth and activity of telomerase, it has been tempting to assume that pattern of telomerase activity in specimens with retarded growth and these with normal growth rate may vary. In the present research, telomerase activity has been examined in liver, skin, and muscles in the androgenetic rainbow trout (Oncorhynchus mykiss) with growth deficiency and their normally developed siblings. Among the examined organs, the liver showed the highest telomerase activity in all studied fish, what may be linked to the enormous regeneration capacity of the liver tissue. Although dwarf specimens examined here displayed significantly lower body size and weight they did not exhibit any significant differences in the telomerase activity measured in liver and muscle when compared to the rainbow trout without growth deficiency. In turn, telomerase activity in skin was significantly upregulated in the normally developed androgenotes. The present study indicates that dwarfism in the androgenetic rainbow trout is neither associated with ceased telomerase activity nor its decrease throughout the ontogenetic development.

Electrochemical oxidation of landfill leachate using boron-doped diamond anodes: pollution degradation rate, energy efficiency and toxicity assessment.

Electrochemical oxidation (EO), due to high efficiency and small carbon footprint, is regarded as an attractive option for on-site treatment of highly contaminated wastewater. This work shows the effectiveness of EO using three boron-doped diamond electrodes (BDDs) in sustainable management of landfill leachate (LL). The effect of the applied current density (25-100 mA cm-2) and boron doping concentration (B/C ratio: 500 ppm, 10,000 ppm and 15,000 ppm) on the performance of EO was investigated. It was found that, of the electrodes used, the one most effective at COD, BOD20 and ammonia removal (97.1%, 98.8% and 62%, respectively) was the electrode with the lowest boron doping. Then, to better elucidate the ecological role of LLs, before and after EO, cultivation of faecal bacteria and microscopic analysis of total (prokaryotic) cell number, together with ecotoxicity assay (Daphnia magna, Thamnocephalus platyurus and Artemia salina) were combined for the two better-performing electrodes. The EO process was very effective at bacterial cell inactivation using each of the two anodes, even within 2 h of contact time. In a complex matrix of LLs, this is probably a combined effect of electrogenerated oxidants (hydroxyl radicals, active chlorine and sulphate radicals), which may penetrate into the bacterial cells and/or react with cellular components. The toxicity of EO-treated LLs proved to be lower than that of raw ones. Since toxicity drops with increased boron doping, it is believed that appropriate electrolysis parameters can diminish the toxicity effect without compromising the nutrient-removal and disinfection capability, although salinity of LLs and related multistep-oxidation pathways needs to be further elucidated.

Phytoplankton of the Curonian Lagoon as a New Interesting Source for Bioactive Natural Products. Special Impact on Cyanobacterial Metabolites.

The bioprospecting of marine and brackish water systems has increased during the last decades. In this respect, microalgae, including cyanobacteria, and their metabolites are one of the most widely explored resources. Most of the bioactive compounds are isolated from ex situ cultures of microorganisms; however, analysis of field samples could also supply valuable information about the metabolic and biotechnological potential of microalgae communities. In this work, the activity of phytoplankton samples from the Curonian Lagoon was studied. The samples were active against antibiotic resistant clinical and environmental bacterial strains as well as against serine proteases and T47D human breast adenocarcinoma cells. No significant effect was found on Daphnia magna. In addition, using LC-MS/MS, we documented the diversity of metabolites present in field samples. A list of 117 detected cyanopeptides was presented. Cyanopeptolins constituted the largest class of cyanopeptides. As complex bloom samples were analyzed, no link between the observed activity and a specific sample component can be established. However, the results of the study showed a biotechnological potential of natural products from the Curonian Lagoon.

Presence of ß-N-methylamino-L-alanine in cyanobacteria and aquatic organisms from waters of Northern Poland; BMAA toxicity studies.

BMAA (ß-N-methylamino-L-alanine) was originally found in the seeds of cycad Cycas micronesica in the 1960s. Some years later it was discovered that the amino acid is genuinely produced by endosymbiotic cyanobacteria. Further research has proven the neurotoxic activity of BMAA, leading to neurodegenerative disease diagnosed as amyotrophic lateral sclerosis/parkinsonism-dementia complex (ALS/PDC). The aim of the present work was to examine the occurrence of BMAA in samples from Polish waterbodies. Both, the field cyanobacterial samples and the isolated cyanobacterial strains were analyzed. Also mussel and fish samples were checked for the BMAA accumulation. The additional goal was to assess the biological activity of BMAA in in vivo and in vitro assays. In waters of Northern Poland, BMAA was detected in cyanobacteria from Synechococcales, Oscillatoriales and Nostocales orders. The free and protein-bound forms of BMAA were detected in 9 and 4 (of 37) environmental samples, respectively. Both forms of BMAA were also identified in 2 out of 21 cyanobacterial strains isolated from Polish waterbodies. Our analyses of cyanobacterial material did not confirm the presence of soluble protein-bound form of BMAA. The amino acid was detected neither in the tissues of fish nor in the mussels. Biological activity of BMAA was tested with the application of hippocampal neural cell line HT22 and crustaceans: Thamnocephalus platyurus, Artemia franciscana and Daphnia magna. Among them, only D. magna assay revealed toxic effects of BMAA. The results of our research did not demonstrate the widespread production of BMAA by cyanobacteria from Northern Poland waters.

Green tea extract prevents the development of nonalcoholic liver steatosis in rats fed a high-fat diet.

Green tea contains many polyphenolic constitutes, which might prevent non-alcoholic fatty liver disease (NAFLD). We aimed to investigate whether green tea extract (GTE) given at doses reflecting habitual consumption of green tea beverages prevents development of NAFLD in rats fed a high-fat diet (HFD). Twenty-four male Wistar rats were randomly divided into four equal groups (two study and two control groups). The study groups received a HFD (approximately 50% energy from fat), enriched with 1.1% and 2.0% GTE, respectively, for a total of 56 days. The control groups were fed a HFD alone and normal standardised diet (low-fat diet), respectively, for the same period of time. The percentage of hepatocytes affected by steatosis in the HFD group (median [1st-3rd quartile]: 25% [12-34%]) was higher (p < 0.033 and p < 0.050, respectively) than in the HFD-2.0%GTE group (9% [3-18%]) and normal diet group (10% [5-18%]). No significant differences were observed for the group consuming HFD-1.1%GTE, in which intermediate results were observed (15% [4-30%]). This finding points towards the hepatoprotective potential of GTE in preventing dietary-induced liver steatosis. In view of the increasing incidence of overweight and obesity a simple and cheap dietary modification, such as GTE supplementation, could prove to be useful clinically.

Morphologic, Phylogenetic and Chemical Characterization of a Brackish Colonial Picocyanobacterium (Coelosphaeriaceae) with Bioactive Properties.

Despite their cosmopolitan distribution, knowledge on cyanobacteria in the family Coelosphaeriaceae is limited. In this study, a single species culture of a coelosphaeran cyanobacterium isolated from a brackish rock pool in the Baltic Sea was established. The strain was characterized by morphological features, partial 16S rRNA sequence and nonribosomal oligopeptide profile. The bioactivity of fractionated extracts against several serine proteases, as well as protein-serine/threonine phosphatases was studied. Phylogenetic analyses of the strain suggested a close relationship with Snowella litoralis, but its morphology resembled Woronichinia compacta. The controversial morphologic and phylogenetic results demonstrated remaining uncertainties regarding species division in this cyanobacteria family. Chemical analyses of the strain indicated production of nonribosomal oligopeptides. In fractionated extracts, masses and ion fragmentation spectra of seven possible anabaenopeptins were identified. Additionally, fragmentation spectra of cyanopeptolin-like peptides were collected in several of the fractions. The nonribosomal oligopeptide profile adds another potential identification criterion in future inter- and intraspecies comparisons of coelosphaeran cyanobacteria. The fractionated extracts showed significant activity against carboxypeptidase A and trypsin. Inhibition of these important metabolic enzymes might have impacts at the ecosystem level in aquatic habitats with high cyanobacteria densities.

Nodularia spumigena peptides--accumulation and effect on aquatic invertebrates.

Thus far, the negative effects of Nodularia spumigena blooms on aquatic organisms have been mainly attributed to the production of the hepatotoxic nodularin (NOD). In the current work, the accumulation of other N. spumigena metabolites in blue mussels and crustaceans, and their effect on Thamnocephalus platyurus and Artemia franciscana, were examined. The liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses provided evidence that both blue mussels collected after a cyanobacterial bloom in the Baltic Sea and the crustaceans exposed under laboratory conditions to N. spumigena extract accumulated the cyclic anabaenopeptins (APs). In the crustaceans, the linear peptides, spumigins (SPUs) and aeruginosins (AERs), were additionally detected. Exposure of T. platyurus and A. franciscana to N. spumigena extract confirmed the negative effect of nodularin on the organisms. However, high numbers of dead crustaceans were also recorded in the nodularin-free fraction, which contained protease inhibitors classified to spumigins and aeruginosins. These findings indicate that cyanobacterial toxicity to aquatic organisms is a complex phenomenon and the induced effects can be attributed to diverse metabolites, not only to the known hepatotoxins.

Increased risk of exposure to microcystins in the scum of the filamentous cyanobacterium Aphanizomenon flos-aquae accumulated on the western shoreline of the Curonian Lagoon.

Concentration of toxic cyanobacteria blooms on the downwind shore of high recreational amenity water bodies with largely increases the risk of exposure to cyanotoxins. In this study analysis of phytoplankton structure, cyanotoxin composition and concentration was performed on cyanobacteria scum material, high- and low-density bloom samples in the Curonian Lagoon. We found that the concentration of cyanotoxins in the scum material increased from ∼30 to ∼300-fold compared to bloom samples. In Microcystis aeruginosa dominated samples microcystin-LR was present at the highest concentration, while the dominance of Planktothrix agardhii was associated with the occurrence of dmMC-RR as the major microcystin variant. The toxicological potential of cyanobacterial scums in the Curonian Lagoon is emphasized, and management by removal of these scums is proposed.

Ghrelin and obestatin in thyroid gland - immunohistochemical expression in nodular goiter, papillary and medullary cancer.

INTRODUCTION: Previous studies analyzing ghrelin and obestatin expression in thyroid gland tissue are not unanimous and are mostly related to ghrelin. The role of ghrelin and obestatin in the thyroid gland appears very interesting due to their probable involvement in cell proliferation. Furthermore, since the thyroid gland is associated with the maintenance of energy balance, the relationship between ghrelin, obestatin and thyroid function is worthy of consideration. The aim of the study was to assess ghrelin and obestatin immunocytochemical expression in nodular goiter (NG), papillary cancer (PTC) and medullary cancer (MTC). MATERIAL AND METHODS: Analyzed samples included 9 cases of NG, 8 cases of PTC and 11 cases of MTC. The analysis of ghrelin and obestatin expression was performed by use of the immunohistochemical (IHC) EnVision system and evaluated with filter HSV software (quantitative morphometric analysis). RESULTS: Quantitative ghrelin expression in MTC cells was higher than in NG (p = 0.013) and correlated negatively with the size of the tumor (r= -0.829, p < 0.05). We did not observe any differences in ghrelin expression neither between MTC and PTC nor between NG and PTC. Obestatin immunoexpression pattern in all analyzed specimens was irregular and poorly accented. The strongest immunoreactivity for obestatin was demonstrated in NG. In MTC obestatin expression was significantly weaker than in NG and PTC (p < 0.05 in both cases). In NG the intensity of obestatin immunostaining was significantly higher than that of ghrelin (p = 0.03). Conversely, ghrelin expression in MTC was definitely more evident than obestatin immunoreactivity (p < 0.01). There was no statistically significant difference between ghrelin and obestatin expression in PTC. No correlations were detected between reciprocal tissue expressions of ghrelin and obestatin in the analyzed specimens of NG, PTC or MTC. CONCLUSIONS: The differences between ghrelin expression in NG and MTC suggest that ghrelin may be involved in thyroid cell proliferation. The differences between ghrelin and obestatin immunoreactivity in benign and malignant thyroid tumors could support the theory of alternative transcription of the preproghrelin gene and independent production of ghrelin and obestatin.

Structures and Activity of New Anabaenopeptins Produced by Baltic Sea Cyanobacteria.

Anabaenopeptins, bioactive cyclic hexapeptides, were isolated by preparative reversed-phase high performance liquid chromatography from an extract of Baltic Sea cyanobacterial bloom material composed of Nodularia spumigena (50%), Aphanizomenon flos-aquae (40%) and Dolichospermum spp. (10%). Five new anabaenopeptins and nine previously known anabaenopeptins were isolated, and their putative structures were determined by tandem mass spectrometry. The activity of the peptides against carboxypeptidase A and protein phosphatase 1 as well as chymotrypsin, trypsin and thrombin was tested. All anabaenopeptins inhibited carboxypeptidase A (apart from one anabaenopeptin variant) and protein phosphatase 1 with varying potency, but no inhibition against chymotrypsin, trypsin and thrombin was observed.

Memantine - neuroprotective drug in aging brain.

Aging is the process of progressive accumulation of changes over time, which is additionally connected with increasing susceptibility to some diseases and ultimately leads to death. Aging is associated mainly with loss of permanent cells, e.g. in heart, skeletal muscle and brain. During aging neurons die mainly in the apoptotic way. Apoptosis can be divided into three phases: initiation, execution and degradation. During the execution phase activation of specific enzymes, caspases, is observed. These enzymes are responsible for initiation of the death machinery. Caspase-9 is connected with the internal pathway of apoptosis, which begins at the mitochondrium in response to apoptotic stimulants, such as free radicals, UV radiation or chemotherapeutics. Before the executive phase starts, cytochrome c leaks from the mitochondrium to the cytoplasm, where it joins to the protein Apaf-1 and procaspase-9 and forms a complex called the apoptosome. Then procaspase-9 is converted by autolysis to caspase-9, which subsequently activates procaspase-3 to the active form which ultimately leads to apoptosis. Immunohistochemical analysis demonstrated a small decrease in caspase-9 and caspase-3 activation during normal aging and an increase in this process after application of stress factors. Also increased apoptosis in the cerebrum after administration of a drug for Alzheimer disease, memantine, to aging rats was observed. Taken together, the results obtained in this study seem to confirm the neuroprotective effect of memantine on increasing levels of cells with active caspase-3 and active caspase-9. It probably improves caspase-dependent apoptosis in the aging brain.

Diversity of peptides produced by Nodularia spumigena from various geographical regions.

Cyanobacteria produce a great variety of non-ribosomal peptides. Among these compounds, both acute toxins and potential drug candidates have been reported. The profile of the peptides, as a stable and specific feature of an individual strain, can be used to discriminate cyanobacteria at sub-population levels. In our work, liquid chromatography-tandem mass spectrometry was used to elucidate the structures of non-ribosomal peptides produced by Nodularia spumigena from the Baltic Sea, the coastal waters of southern Australia and Lake Iznik in Turkey. In addition to known structures, 9 new congeners of spumigins, 4 aeruginosins and 12 anabaenopeptins (nodulapeptins) were identified. The production of aeruginosins by N. spumigena was revealed in this work for the first time. The isolates from the Baltic Sea appeared to be the richest source of the peptides; they also showed a higher diversity in peptide profiles. The Australian strains were characterized by similar peptide patterns, but distinct from those represented by the Baltic and Lake Iznik isolates. The results obtained with the application of the peptidomic approach were consistent with the published data on the genetic diversity of the Baltic and Australian populations.

[The awareness of addictive effect of nicotine --a questionnaire survey of students and employees of CM UMK]. / Swiadomosc uzalezniajacego dzialania nikotyny--badania ankietowe studentów i pracowników CM UMK.

Tobacco is one of the main factors responsible for the development of human tumors, cardiovascular diseases and non-malignant respiratory diseases. Tobacco products are harmful to health and they contain nicotine, which is highly addictive. Many studies in humans and in animal models have shown that nicotine is addictive psychoactive drug, which triggers a cascade of neurobiological events in the brain reward centers leading to the intensity of behavior what aims to enhanced use of tobacco. In Poland the number of smokers is estimated at about 9.5 million people. Among active smokers is a significant number of medical students. 480 people have joined the study (253 women and 227 men): 416 student of Collegium Medicum in Bydgoszcz of Nicolaus Copernicus University in Torun (CM UMK), 59 students of biomedical engineering at the University of Technology and Life Sciences in Bydgoszcz and 5 employees of CM UMK. 13% of all respondents admitted to smoking cigarettes. Respondents students and university staff mainly responded affirmatively to the question about psychoactive addiction by smoking-Performed questionnaire also revealed a high awareness about the use of nicotine during smoking cessation. Most people had their first contact with tobacco smoke in the early years of life, meeting with tobacco smoke in the home and in school. A much smaller percentage of the students met for the first time to tobacco smoke in the later stages of education: high school and college. Even fewer respondents had their first encounter with tobacco smoke in the workplace. In summary, we can conclude that students and workers CM UMK show considerable awareness of the dangers of smoking and the addictive properties of tobacco smoke.

[The awareness of carcinogenic effect of tobacco smoke--a questionnaire survey of students and employees of Collegium Medicum of Nicolaus Copernicus University]. / Swiadomosc rakotwórczego dzialania dymu tytoniowego--badania ankietowe studentów i pracowników CM UMK.

Smoking is currently the most significant risk factor for health according to WHO statements. It has been proven that smoking is the cause of many diseases, for example cardiovascular and respiratory tract diseases as well as impaired fertility and decreased immunity. The adverse effects of cigarette smoking on pregnancy and health of children were also proved. However, special attention is laid on impact of smoking on the development of cancer. In tobacco smoke there are over 4,000 different chemical substances and compounds, of which more than 50 are carcinogens. The present study was aimed to assess the knowledge of students and employees of Collegium Medicum of Nicolaus Copernicus University in Torun (CM UMK), first on number and types of carcinogens contained in tobacco smoke and secondly on types of diseases caused by smoking. There were 480 responders included to the study(253 women and 227 men). Among them there were 416 students of CM UMK, 59 students of biomedical engineering at the University of Technology and Life Sciences in Bydgoszcz and 5 employees of CM UMK. Among the respondents there was considerable ignorance about the number of carcinogens contained in tobacco smoke with over 50% of them indicating the incorrect answer. Among the carcinogens there were mentioned mostly tar and nicotine, and among the diseases caused by tobacco smoke most often pointed response there were lung and larynx cancer and heart and blood vessels diseases and to reduce the weight of newborns. In summary, we can conclude that the awareness of students and employees of CM UMK about the carcinogenic properties of tobacco smoke was not sufficient. Respondents were aware of the dangers of smoking, they knew the basic carcinogenic substances and pointed a few diseases caused by smoking cigarettes. Unfortunately their knowledge does not refer to a number of diseases which in common believe are not connected to cigarette smoking, but in fact tobacco smoke is very important for their development.