Disposition and metabolism of 2,3,7,8-tetrachlorodibenzofuran by rainbow trout (Oncorhynchus mykiss).

The disposition and metabolism of 2,3,7,8-tetrachlorodibenzofuran (TCDF) was investigated in rainbow trout (Oncorhynchus mykiss) in order to better understand the metabolic and physiological factors that modulate the fate of this extremely toxic compound in rainbow trout compared to other species. The fish were dosed orally with [3H]TCDF (1 microgram/kg); fish were terminated at 1-19 days for the determination of whole body half-life or at 0.3-28 days for determination of tissue distribution. Unassimilated TCDF (51.5% of the dose) was eliminated with a half-life of 0.84 days. The assimilated body burden of TCDF equivalents decreased with a half-life of 14.8 days (determined between 3 and 19 days). Trout muscle showed a relatively high capacity to accumulate and retain (unmetabolized) TCDF, accounting, at 3 days, for 32% of the body burden of TCDF equivalents (half-life in muscle, 15.2 days). Trout liver, on the other hand, showed a relatively low capacity to accumulate and metabolize TCDF. At 3 days, the concentrations of TCDF equivalents in liver and bile were, respectively, 0.37 ng/g liver (0.88% of the body burden) and 4.8 ng/ml bile. The data suggest that the relatively high affinity of lipid-rich trout muscle for TCDF limits the ability of the liver to accumulate and metabolize TCDF. The major TCDF metabolites found in trout liver and bile were, respectively, 4-OH-TCDF and TCDF-4-O-glucuronide.

Disposition and metabolism of 2,3,7,8-tetrachlorodibenzofuran by channel catfish (Ictalurus punctatus).

The disposition and metabolism of 2,3,7,8-tetrachlorodibenzofuran (TCDF) was was investigated in channel catfish (Ictalurus punctatus) in order to better understand the metabolic and physiological factors that modulate the fate of this extremely toxic compound in channel catfish compared to other species. The fish were dosed orally with [3H]TCDF (1 microgram/kg); tissue were harvested at 3, 7, and 14 days for radioassay. The body burden of TCDF equivalents in catfish at 3 days was 0.36 microgram/kg, which was decreasing with a half-life of 3.6 days. Catfish muscle showed a relatively low capacity to accumulate and retain TCDF, accounting, at 3 days, for only 19.0% of the body burden of TCDF equivalents (half-life in muscle, 5.0 days). Catfish liver, on the other hand, showed a high capacity to accumulate and metabolize TCDF and to secrete TCDF metabolites into the bile. At 3 days, the concentrations of TCDF equivalents in liver and bile were, respectively, 5.7 ng/g liver (19% of the body burden) and 129 ng/ml bile. However, the concentration of TCDF equivalents in liver decreased with a half-life of 1.8 days to 0.04 ng/g (2.0% of the body burden) at 14 days. Thus, the capacity of catfish liver to retain TCDF decreased dramatically as the body burden decreased. The data suggest that the low affinity of lipid poor catfish muscle for TCDF may allow catfish liver to accumulate a concentration of TCDF sufficient to induce the metabolism of this compound by liver monooxygenases. The major TCDF metabolites found in catfish liver and bile were, respectively, 4-OH-TCDF and TCDF-4-O-glucuronide.

[Effect of feeding methods in infants on serum lipid profile]. / Wplyw sposobu zywienia niemowlat na profil lipidów surowicy krwi.

Mothers very often do not start to breast feed their children, or stop very quickly and introduce various formulas based either on modified or unmodified cow's milk. These infant formulas differ from human milk in their chemical composition. Breast milk is the most suitable source of all nutrients required for the development of a newborn or infant. The serum levels of total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides and phospholipids were determined. The influence of the type of feeding on the levels of the above-mentioned lipids was analyzed. Higher serum levels of triglycerides in babies fed formulas based on modified cow's milk than in those fed formulas based on unmodified milk were found. Higher serum levels of phospholipids were found in breast-fed babies than in those fed formulas based on unmodified cow's milk.

[Effect of treatment at a health resort in a plains climate on peak expiratory flow values in preschool children with respiratory disorders]. / Wplyw leczenia sanatoryjnego w klimacie podgórskim na wartosc szczytowego przeplywu wydechowego u dzieci w wieku przedszkolnym z chorobami dróg oddechowych.

PEF is the most widely used parameter to assess airflow limitations of the airways. The aim of the study was to assess the value of climatic treatment in the sub-mountainous region on PEF values in pre school age children with various respiratory diseases, inhabitants of the upper silesian industrial region. In 113 children (age 4-6) PEF values were recorded at the beginning and end of the 21 day stay at the sanatorium. PEF was recorded using the Vitalo-graph meter. The results of the study revealed an increase of PEF values was statistically significant.

[Normal values of peak expiratory flow in children from an environment with high degree of atmospheric air pollution]. / Wartosci nalezne (normy) szczytowego przeplywu wydechowego u dzieci ze srodowiska o wysokim stopniu zanieczyszczenia powietrza atmosferycznego.

Peak expiratory flow (PEF) has been measured with Vitalograph (in liters per minute) in 2,512 school-children aged between 7 and 15 years in Upper Silesian Industrial Region. Five hundred eighty one children from Zarki near Czestochowa served as a control group. The results have been analysed statistically. Determined PEF values for children from the Upper Silesian Industrial Region are considered as a biological reference values for assessment of PEF in both health and disease. PEF values calculated for children from Zarki were higher than those in the examined group, except the value for a 14-year old children.

Evaluation of elastin metabolism in children from families with high risk of atherosclerosis.

Markers of elastin metabolism were estimated in sera of children from families with a high risk of atherosclerosis (ATH). There was no statistically significant difference in the serum elastase-like activity between the groups studied. The concentration of elastin-derived peptides was statistically significantly elevated in the ATH group. Anti-elastin antibodies were found to be present in 73% of ATH children, while they circulated in 5% of control subjects only. Antibodies observed in the youngest ATH children were of the IgM type, suggesting the initial stage of the autoimmunization to elastin. The data obtained in this study may indicate an enhanced metabolism of elastin in ATH children.

Magnetooptical modulator with crystal in a separated auxiliary field.

The classical magnetooptic modulator based on Faraday rotation is improved by using the separated auxiliary field instead of a perpendicular one. Theoretical analysis indicates an improvement in some modulator parameters. Experiments have confirmed growth of the modulation depth and reduction in nonlinear characteristics of the modulator.