High Variability in Sediment Characteristics of a Neotropical Stream Impacted by Surface Mining and Gully Erosion

This study examined patterns of stream sediment granulometry, organic matter (OM) and metal concentration, and surface water characteristics in a catchment in the Brazilian Iron Quadrangle that is highly impacted by surface iron mining and gully erosion. Sediment granulometry indicated fine sediment deposition at impacted stream sites, i.e., tendencies towards bimodal particle size distributions with an additional peak in the sand fraction at impacted stream sites that did not occur at pristine reference sites, as well as towards smaller mean sediment particle sizes at impacted sites than at reference sites. Impacted sites also had significantly lower sediment OM contents than reference sites. Sediment heavy metal and arsenic concentrations did not differ between impacted and reference sites and were generally below published target or threshold effect concentrations. Impacts on surface water characteristics occurred only locally at a site that received tailings pond effluent from an iron mine and had very low pH and conductivity values. Sediment characteristics exhibited substantial spatial variability in the studied tropical catchment, showing that land use impacts can hardly be detected in routine monitoring and impact assessment studies that adopt a before–after control-impact approach and do not consider pristine reference streams. These results underline the importance of high-resolution and long-term sediment monitoring as well as integrated basin-scale sediment management programs.     

Pregnancy-associated Glycoprotein Profile during the First Trimester of Pregnancy in Egyptian Buffalo Cows

Pregnancy-associated glycoprotein (PAG) concentrations were measured in buffalo cows starting from day 28 after breeding. Oestrus was synchronized in 10 buffaloes using two injections of 25 mg prostraglandin (PG)F_{2 α} (Lutalyse^®) at a 11-day interval. Blood sampling was conducted nearly twice weekly. Results indicated that plasma PAG concentrations in non-pregnant buffaloes were low (<0.20 ng/ml) during the whole experimental period (day 28 to 103), while in pregnant animals plasma PAG levels increased from day 28 (4.48 ± 0.92 ng/ml) until day 41 (27.27 ± 6.74 ng/ml), remaining high (20.71 ± 9.20 ng/ml) until day 103. Progesterone levels were significantly (p < 0.0001) higher in pregnant (3.51–4.80 ng/ml) than in non-pregnant buffaloes (0.28–1.52 ng/ml). A significant difference (p < 0.0001) in plasma PAG concentrations between pregnant and non-pregnant animals starting at day 28 after breeding suggests that PAG-radioimmunoassay could be suitable for pregnancy diagnosis in buffaloes during this period. In conclusion, PAG test offers the advantages that it requires a single plasma sample for early pregnancy diagnosis as well as the accuracy of the test for the detection of pregnancy as early as day 28.     

Anticancer activity evaluation of kuanoniamines A and C isolated from the marine sponge Oceanapia sagittaria, collected from the Gulf of Thailand

The pyridoacridine alkaloids kuanoniamines A and C were isolated together with 24 α-methylcholestanol, p-hydroxybenzaldehyde, p-hydroxybenzoic acid, phenylacetic acid and 3-formylindole from the ethyl acetate extract of the marine sponge Oceanapia sagittaria (Sollas), collected from the Gulf of Thailand. Kuanoniamines A and C were evaluated for their effect on the growth of five human tumour and a non-tumour cell lines, as well as on the proliferation of human lymphocytes. Kuanoniamine A was found to be a potent growth inhibitor of all the tumour and a non-tumour cell lines while kuanoniamine C was less potent but showed high selectivity toward the estrogen dependent (ER+) breast cancer cell line. Kuanoniamine A has shown to be a more potent inhibitor of DNA synthesis than kuanoniamine C. Kuanoniamine A was also found to cause an extensive reduction of the MCF-7 cells in G2/M phase as well as an increase in the apoptotic cells.