Pregnancy Loss and Maternal Methemoglobin Levels: An Indirect Explanation of the Association of Environmental Toxics and Their Adverse Effects on the Mother and the Fetus

The aim of this epidemiologic study was to point out a relationship between the exposure to products of coal combustion, and complications in pregnancy where one third of causes of stillbirth are still unknown. In the town of Labin (Croatia) a coal-powered thermoelectric power plant is the single major air polluter. We compared the records of miscarriages, premature births and stillbirths in two periods: the control and the exposure period. Data on reproductive loss was based on the records of pregnant women visiting for regular monthly pregnancy checkups. At the time of the epidemiological prospective study, 260 women (n = 138 in the clean period and n = 122 in the dirty period) were considered representative. The data were processed using Chi square and correlation tests. The frequencies of miscarriages and stillbirths were significantly lower in the control than in the exposure period (p < 0.05). Methemoglobinemia and stillbirths recorded over the “exposure” period are significantly higher than in the “control” period (p = 0.0205). The level of methemoglobin in the bloodstream is an worthy biomarker, predictor and precursor of environmental toxics’ adverse effects on the mother and fetus, and can indirectly explain the unrecognized level of fetal methemoglobin. Methemoglobin and heme, having prooxidant properties, also cause the early and late endothelial dysfunction of vital organs. Despite our retrospective epidemiological study findings, we emphasize that the rate of reproductive loss represents a hypothetical risk, which needs to be confirmed with further fetal clinical and anatomopatholgical researches about the effects of methemoglobin catabolism products on the fetal CNS

Influence of tumor thickness and vascularity on survival in cutaneous melanoma.

Eighty-eight cases of cutaneous melanoma (CM) were analyzed in order to elucidate the relationship between thickness, angiogenesis, and prognosis. The thickness of the tumor was measured according to the Breslow method, and the microvessels were identified by an immunohistochemical study using anti-factor VIII monoclonal antibody on specimens from 40 patients with superficial spreading melanoma (SSM), and 48 with nodular type (NM). Microvessels were counted in the area of highest density. The overall survival and disease-free period were analyzed retrospectively. The proportion of patients with thicker CMs (&#62; 1.5 mm) increased with age in both sexes. Mean vascular count was statistically significant different only between thinner and thicker tumors in the SSM group (P &#60; 0.05). Prognosis was correlated with the thickness of CM (P = 0.0002), mean vascular count alone (P = 0.004), mean vascular count in association with CM thickness less than 1.5 mm (P = 0.0005), and with mean vascular count in NM (P = 0.02). These findings suggest that increasing microvessel density indicates a worsening prognosis.</p

Ecotoxicological Characterization of Marine Sediment in Kostrena Coastal Area

Samples of marine sediment were taken on 4 selected sites close to the shipyard industry in Kostrena coastal area. Concentration of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and heavy metals (Cu, Pb, Zn, Hg, Fe) were analyzed from chemical-analytical and toxicological aspect. For toxicity detection, the bacterial bioluminescence test (Vibrio fisheri) was used. Concentration of total PAHs varied in the range from 697 to 7807 mg/kg dry weight in marine sediments. The concentration of PCBs in sediment was 1.1 mg/kg dry weight. The highest concentrations of heavy metals were found at the station within the shipyard. PAH toxicity was not correlated with the toxic potential of sediments. The obtained results indicate a high degree of environmental risk, especially at stations within the shipyard, with the 54% possibility of toxic effects. Chemical determination of the concentration of conventional pollutants is not sufficient for assessing the quality of themarine environment and it is necessary to use other approaches in order to evaluate the biological impact

Ecotoxicological Characterization of Marine Sediment in Kostrena Coastal Area

Samples of marine sediment were taken on 4 selected sites close to the shipyard industry in Kostrena coastal area. Concentration of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and heavy metals (Cu, Pb, Zn, Hg, Fe) were analyzed from chemical-analytical and toxicological aspect. For toxicity detection, the bacterial bioluminescence test (Vibrio fisheri) was used. Concentration of total PAHs varied in the range from 697 to 7807 mg/kg dry weight in marine sediments. The concentration of PCBs in sediment was 1.1 mg/kg dry weight. The highest concentrations of heavy metals were found at the station within the shipyard. PAH toxicity was not correlated with the toxic potential of sediments. The obtained results indicate a high degree of environmental risk, especially at stations within the shipyard, with the 54% possibility of toxic effects. Chemical determination of the concentration of conventional pollutants is not sufficient for assessing the quality of themarine environment and it is necessary to use other approaches in order to evaluate the biological impact

The effects of acutely and subchronically applied DL-methionine on plasma oxidative stress markers and activity of acetylcholinesterase in rat cardiac tissue

© 2020 Inst. Sci. inf., Univ. Defence in Belgrade. All rights reserved. Background/Aim. Chronically induced hypermethioninemia leads to hyperhomocysteinemia which causes oxidative stress, atherogenesis, neurodegeneration and cancer. However, little is known about the acute and subchronic effects of DL-methionine (Met). The aim of study was to assess the effects of acutely and subchronically applied Met on oxidative stress parameters in rat plasma [enzymes: catalase (CAT), glutathione peroxidise (GPx), superoxide dismutase (SOD) and index of lipid peroxidation, malondialdehyde (MDA)], and acetylcholinesterase (AChE) activity in rat cardiac tissue. Methods. The enzymes activities, as well as MDA concentration were evaluated following acute (n = 8) and subchronic (n = 10) application of Met [i.p. 0.8 mmoL/kg body weight (b.w.) in a single dose in the acute overload or daily during three weeks in the subchronic overload]. The same was done in the control groups following application of physiological solution [i.p. 1 mL 0.9% NaCl (n = 8) in the acute overload and 0.1–0.2 mL 0.9% NaCl, daily during three weeks (n =10) in the subchronic overload]. Tested parameters were evaluated 60 minutes after application in acute experiments and after three weeks of treatment in subchronic experiments. Results. There were no difference in homocysteine values between the groups treated with Met for three weeks and the control group. Met administration significantly increased the activity of CAT and GPx after 1 h compared to the control group (p = 0.008 for both enzymes), whereas the activity of SOD and MDA concentrations were unchanged. Subchronically applied Met did not affect activity of antioxidant enzymes and MDA level. AChE activity did not show any change in rat cardiac tissue after 1 h, but it was significantly decreased after the subchronic treatment (p = 0.041). Conclusion. Results of present research indicate that Met differently affects estimated parameters during acute and subchronic application. In the acute treatment Met mobilizes the most part of antioxidant enzymes while during the subchronic treatment these changes seems to be lost. On the contrary, the acute Met overload was not sufficient to influence on the AChE activity, while longer duration of Met loading diminished function of the enzyme. These findings point out that methionine can interfere with antioxidant defense system and cholinergic control of the heart function