Veden ja järvisedimenttien laatu Vihtamonjoen valuma-alueella Sotkamossa

The study area, Vihtamonjoki catchment area, is 55 square kilometres and a third of it has been ditched. The largest ditchings have been done in years 1959-1970. The water system in the catchment area builds up of several lake basins, brooks and rivers. This study tries to discover the water quality at present. It also tries to determine the sedimentation rate and the changes on the sediment quality during the past decades. The water samples were collected in August 2003 and in March 2004 from several places in the catchment area. On March 2004 the sediment samples were collected from four lake basins. Organic matter, total phosphorus, iron, manganese, Fe/Mn-ratio, zinc and copper were determined from sediment samples. The water quality was determined by electric conductivity, alkalinity, pH, oxygen content and the content of sodium, potassium, magnesium, calcium, sulphate, chlorine and fluoride. Also the nutrients, nitrate, ammonium and phosphate, were determined. Chemical analyses and loss on ignition analyses showed clear changes in sediment quality in samples taken from 15-25 cm depth, thus showing the time of the ditching. In most cases the forest ditching had caused increase in mineral matter, iron, zinc and copper and decrease in total phosphorus and organic matter. Sedimentation rates vary between 4,1 to 6,7 mm/year in lakes after the forest ditching. Sedimentation rates have probably increased due to the forest ditching. The Fe/Mn-ratio shows that there has been a lack of oxygen in the lakes for some years after the forest ditching. The water quality proved to be normal in the Vihtamonjoki catchment area. Oxygen content in March 2004 pointed to the conclusion that there might be lack of oxygen in winter. Other analysis showed the water quality to be typical for the Kainuu area.

Studies on the 14α-hydroxylation of progesterone in mucor piriformis

Cell-free extracts with high 14?-hydroxylase activity were prepared from induced vegetative cell cultures of Mucor piriformis by grinding in potassium phosphate buffer (0.05 M, pH 8.0) containing glucose (0.25 M), KCl (1 mM), glutathione (1.0 mM) and glycerol (10%). Although the ideal pH for preparing the cell-free extract from vegetative cells was 8.0, the pH optimum of the hydroxylase was found to be 7.6. Microsomes (2.0 mg) prepared from the crude cell-free extract hydroxylated progesterone to 14?-hydroxyprogesterone in not, vert, similar60% yields in 30 min in the presence of NADPH and O2. Microsomes prepared from the uninduced cells did not contain any 14?-hydroxylase activity. The hydroxylase activity was inhibited to a significant extent by CO and p-chloromercuribenzoate whereas moderate inhibition was noticed in the presence of SKF-525A, metyrapone and N-methylmaleimideindicating the possible involvement of the cytochromeP-450 system in the reaction. The membrane bound hydroxylase was solubilized using Triton X-100 and the solubilized fraction contained nearly 35% of the original hydroxylase activity.

Formation of a G-quadruplex at the BCL2 major breakpoint region of the t(14;18) translocation in follicular lymphoma

The t(14;18) translocation in follicular lymphoma is one of the most common chromosomal translocations. Most breaks on chromosome 18 are located at the 3'-UTR of the BCL2 gene and are mainly clustered in the major breakpoint region (MBR). Recently, we found that the BCL2 MBR has a non-B DNA character in genomic DNA. Here, we show that single-stranded DNA modeled from the template strand of the BCL2 MBR, forms secondary structures that migrate faster on native PAGE in the presence of potassium, due to the formation of intramolecular G-quadruplexes. Circular dichroism shows evidence for a parallel orientation for G-quadruplex structures in the template strand of the BCL2 MBR. Mutagenesis and the DMS modification assay confirm the presence of three guanine tetrads in the structure. 1H nuclear magnetic resonance studies further confirm the formation of an intramolecular G-quadruplex and a representative model has been built based on all of the experimental evidence. We also provide data consistent with the possible formation of a G-quadruplex structure at the BCL2 MBR within mammalian cells. In summary, these important features could contribute to the single-stranded character at the BCL2 MBR, thereby contributing to chromosomal fragility.