ABSTRACT
The influence of ultraviolet radiation (UV) on cadmium availability to freshwater mussel (Unio tumidus) in the presence of organic matter was investigated. Water solutions containing 1000, 500, and 250 microg x L(-1) of cadmium and 28.8 mg x L(-1) of total organic carbon (TOC) were exposed to ecologically relevant biologically effective UV-A and UV-B irradiances of 1.73 x 10(-6) W x cm(-2) and 1.50 x 10(-5) W x cm(-2) respectively for 12 h. The availability of cadmium was measured directly as Cd concentration in gills, mantle, digestive gland and foot, and indirectly as its impact on the content of essential cations. The concentration of cadmium ions, soluble forms of cadmium, pH and conductivity in UV irradiated solutions were also measured. UV exposures resulted in a decrease of the TOC to 25.9 mg x L(-1), followed by a decrease in the total concentration of Cd soluble forms, increase in the concentration of cadmium bound to particulate matter, and increase in the concentration of free cadmium ions in comparison to non-irradiated mixtures. Mussels from mixtures exposed to UV accumulated more cadmium than specimens from non-irradiated mixtures. This was confirmed by the fluctuations of essential cations, i.e. decreases in the contents of Zn, Ca, Fe and increase of the Cu content. Na/K molar ratios in gills were negatively correlated with cadmium content, while a positive trend occurred in other organs. We suggest that in UV-exposed water more ionic forms of cadmium occur. On the other hand more cadmium is also bound to particulate matter. Our research indicate that the increase of cadmium accumulation in mussels grown in humic acid solutions exposed to UV were most probably related to the increase in the concentration of cadmium bound to particulate matter.
Subject(s)
Cadmium/metabolism , Humic Substances/analysis , Ultraviolet Rays , Unio/metabolism , Unio/radiation effects , Animals , Biological Availability , Cadmium/analysis , Carbon/analysis , Cations/metabolism , Digestive System/metabolism , Fresh Water/analysis , Fresh Water/chemistry , Gills/metabolismABSTRACT
Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in cystic fibrosis transport regulator (CFTR) gene. The clinical picture is characterized mainly by: bronchopulmonary disease (BPD), exocrine pancreatic insufficiency, hepatobiliary disease, meconium ileus, malnutrition and congenital bilateral absence of vas deferens. Life-span is closely related to respiratory system status, thus making the treatment of the BPD the key element of the management of CF. BPD is characterized by progressive destruction of bronchopulmonary tissues. It is due to chronic inflammation which, in turn, is caused chronic colonization/infection by typical pathogens, such as Pseudomonas aeruginosa, Staphylococcus aureus and Burkholderia cepacia. The end stage of the BPD is respiratory insufficiency and death. The diagnosis of cystic fibrosis is based on the clinical picture, sweat chloride test, molecular analysis and measurement of nasal potential difference.
Subject(s)
Cystic Fibrosis/diagnosis , Bacterial Infections/diagnosis , Bacterial Infections/etiology , Cystic Fibrosis/complications , Cystic Fibrosis/genetics , HumansABSTRACT
Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in cystic fibrosis transport regulator (CFTR) gene. The clinical picture is characterized mainly by: bronchopulmonary disease (BPD), exocrine pancreatic insufficiency, hepatobiliary disease, meconium ileus, malnutrition and congenital bilateral absence of vas deferens. Life-span is closely related to respiratory system status, thus the treatment of the BPD is the key element of the management of CF. BPD is characterized by progressive destruction of bronchopulmonary tissues. It is due to chronic inflammation which, in turn, is caused by chronic colonization/infection by typical pathogens, such as Pseudomonas aeruginosa, Staphylococcus aureus and Burkholderia cepacia. The end stage of the BPD is the respiratory insufficiency and death. Management of BPD is complex, but two main aspects can be distinguished: treatment of exacerbations and chronic therapy. The first one is based on aggressive antibiotic treatment. The second one includes: chronic antibiotic administration, mucolytic therapy, control of bronchial hyperreactivity, anti-inflammatory treatment, oxygen supplementation and physiotherapy. The huge progress in management of cystic fibrosis achieved in last years can be proved by the fact that the mean life-span of patients increased from about 20 years in early seventies to nearly 50 years nowadays.