323,439 research outputs found
Cholinesterase activities in the scallop Pecten jacobaeus: characterization and effects of exposure to aquatic contaminants
No full textNearshore marine environments of industrialized countries are increasingly threatened by anthropogenic pollution. It is therefore a priority task to investigate the sensitivity of new ecotoxicological warning signals of the occurrence and effects of aquatic pollutants. The main aims of the present study were: 1) to characterize the biochemical properties of ChEs in tissues of the bivalve Pecten jacobaeus, using different specific substrates and selective inhibitors; 2) to measure sensitivity of ChE activities to in vitro exposure to the OPs azamethiphos and DFP and to the heavy metals cadmium and zinc. Our final aim was to carry out a preliminary evaluation of the suitability of ChEs measurement in tissues of the scallop for monitoring marine environmental quality and neurotoxic compounds contamination in the Mediterranean Sea. Responses to specific inhibitors have suggested that ChEs in adductor muscle share many characteristics with vertebrate acetylcholinesterase. Dose-dependent inhibition of ChE was observed in response to in vitro exposure to environmental contaminants such as cadmium and azamethiphos. Sensitivity to zinc and DFP was lower. ChEs in P. jacobaeus might therefore have potential as a sensitive biomarker for monitoring marine pollution. Results of the present study will be useful to focus further experiment of exposure to pollutants under in vivo conditions. Capsule: Cholinesterase activities in scallop Pecten jacobaeus were observed to be sensitive to contaminants in vitro and may therefore have potential as biomarkers for monitoring water pollution. © 2007 Elsevier B.V. All rights reserved
Characterization and sensitivity to pollutants of cholinesterases in the Antarctic scallop Adamussium colbecki
No full textAntarctica is affected by man-made contamination and development of sensitive ecotoxicological tools for impact assessment is a priority task. The aims of the present study were to characterize cholinesterase (ChE) activities in an Antarctic key species, the scallop Adamussium colbecki, and to investigate their sensitivity as biological markers (biomarkers) of exposure to pollutants and of their effects. Our results show that ChEs in gills share most characteristics with true acetylcholinesterase. The present results show that ChE activities in A. colbecki are significantly inhibited by organophosphates (OPs) and somehow affected by in vitro exposure to mixtures of marine contaminants such as polycyclic aromatic hydrocarbons (PAHs), even if no concentration-dependent pattern of response was observed and no effect was elicited by polychlorinated biphenyls (PCBs). The present results do not demonstrate ChEs in A. colbecki as sensitive tools to measure exposure to the above chemicals, but they may be worthy of further study considering the importance of the scallop in Antarctic marine ecosystems and its suitability as a sentinel species. © 2009 Elsevier Inc. All rights reserved
Cholinesterase activities in the adductor muscle of the Antarctic scallop Adamussium colbecki
No full textAntarctica is regarded as one of the most pristine parts of the Earth but even this remote ecosystem is affected by contamination and high levels of certain heavy metals, such as cadmium, which may occur naturally in Antarctic waters. The bivalve scallop Adamussium colbecki is considered a key species of Antarctic benthic ecosystems and a sensitive target for bioaccumulation of xenobiotics and metals. Since cholinesterases (ChEs) in the adductor muscle of A. colbecki presumably play a prominent physiological role through regulation of swimming movements, the main aims of this study was to characterize ChE activities in adductor Muscle of A. colbecki and to investigate their sensitivity to organophosphate pesticides and heavy metals. The results suggest that an acetylcholinesterase-like enzyme in the adductor muscle of the scallop has low sensitivity to organophosphates but was significantly inhibited by exposure to cadmium
Dyck Paths Enumerated by the Q-bonacci Numbers
No full textWe consider Dyck paths having height at most two with some constraints on the number of consecutive valleys at height one which must be followed by a suitable number of valleys at height zero. We prove that they are enumerated by so-called Q-bonacci numbers (recently introduced by Kirgizov) which generalize the classical q-bonacci numbers in the case where q is a positive rational.In Proceedings GASCom 2024, arXiv:2406.1458
Aging populations: the health and quality of life of the elderly.
No full textThe progressive tendency for the age structure of the population to shift towards the elderly has been observed in all developed countries and this has important implications for health, society, economics and epidemiology. According to the most recent estimates for the world, the number of persons aged over 60 years will double from the present number, 756 to 1400 millions by 2030. In Italy, by the year 2050, 34.6% of the population will be aged more than 65 years. This will have important implications for health. There are medical conditions that occur almost exclusively among the elderly and these are sometimes referred to as syndromes or geriatric pathologies; other conditions that can occur at younger ages, may present with different symptoms, and cause complications in the elderly. More than just the single pathologies, the presence of two or more conditions simultaneously may have a critical impact on the health status of the elderly. As their ages increase, the elderly may be considered "frail"; factors, not only physical but also psychological cognitive and social, contribute to this syndrome and all must be considered together in the diagnosis and treatment of the elderly patient. These subjects are at greater risk of physical and cognitive decline, disability and death. As the elderly are an increasing fraction of the total patient load, their problems require that the structure and organization of health services be accordingly adjusted and also that the cultural and professional training of doctors and other medical personnel is appropriate. As a consequence, the objective of governments should be to promote the health and the quality of life of the elderly and this would include primary secondary and tertiary prevention applied in a variety of different settings. The choice of the preventive measures should be determined by the general health status of the elderly individuals, of whom 60-75% are classified as healthy, 20-30% are diagnosed as suffering chronic diseases, and 2-10% are regarded as "frail". For pathologies which do not require hospitalization, among the other existing services there is also Integrated Home Help (Assistenza Domiciliare Integrata, ADI) and Medically Assisted Residences (Residenze Sanitarie Assistenziale, RSA)
Induction of EROD activity in European eel (Anguilla anguilla) experimentally exposed to B(a)P and βNP
No full textThe induction of liver ethoxyresorufin O-deethylase (EROD) activity was investigated in the European eel, Anguilla anguilla, collected from a Mediterranean brackish environment and experimentally exposed to benzo[a]pyrene (B[a]P) and h-naphthoflavone (BNF). Eels were injected intraperitoneally at increasing doses (0.1, 1, 10, and 50 mg/kg wet body weight) using corn oil as a carrier and sacrificed after 7 days. The main objectives of the present study are: (1) to assess of the sensitivity of EROD induction as a biomarker to polycyclic aromatic hydrocarbon (PAH) exposure; (2) to determine an EROD dose–response relationship of the contaminants used; and (3) to compare the efficiency of B[a]P and BNF as inducers of EROD activity. Results showed that both chemicals resulted in a dose-dependent EROD induction, but increases were not linear. EROD activity seemed to reach a plateau at the exposure of 10 mg/kg in both treatment groups; B[a]P was a more potent inducer than BNF was at the higher doses (10 and 50 mg/kg), while the opposite result was observed at the lower ones (0.1 and 1 mg/kg). The greatest induction occurred in eels treated with 10 mg/kg B[a]P, in which a 261-fold increase in EROD activity was observed. Results showed that EROD activity in A. anguilla is significantly induced by B[a]P and BNF exposure, responding to a wide range of concentrations of these contaminants. We infer that this tool may be suited as a diagnostic biomarker for biomonitoring PAHs pollution in Mediterranean brackish environments and further field research is suggeste
Induction of EROD activity in European eel (Anguilla anguilla) experimentally exposed to benzo(a)pyrene and b-naphtoflavone.
No full textCholinesterase activities in the Antarctic scallop Adamussium colbecki: sensitivity to pollutants
No full textPCB muscle content and liver EROD activity in the European eel (Anguilla anguilla) treated with Aroclor 1254.
No full textComparative induction of liver EROD and BaPMO activities in European eel (Anguilla anguilla) by benzo[a]pyrene and 2,3,7,8-tetrachlorodibenzo-p-dioxin: a laboratory study
No full textThe objective of the present study was to assess and compare the sensitivity of EROD and BaPMO enzymatic activities as biomarkers of exposure to increasing doses of benzo[a]pyrene (B[a]P) and polychlorinated 2,3,7,8-tetrachloro dibenzo-para-dioxin (2,3,7,8-TCDD) in Anguilla anguilla. Eels collected from a Mediterranean brackish environment were experimentally exposed to chemicals by intraperitoneal injection and sacrificed seven days later. Both EROD and BaPMO activities showed close dose-response relationships to chemicals, even, if the Presence of a plateau in EROD induction at concentrations above 10 mg/kg B[a]P is suggested. Higher induction occurred for EROD than for BaPMO activity in almost all the groups of exposure. Both EROD and BaPMO activities in A. anguilla appear to be suitable biomarkers to PAHs and PCDDs exposure and a higher sensitivity is suggested for EROD induction as biomarker of exposure to such chemicals
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