Fate of natural organic matter and oxidation/disinfection by-products formation at a full-scale drinking water treatment plant.

This paper investigates the fate of natural organic matter (NOM) during the full-scale drinking water treatment plant supplied by Danube river bank filtration. After the recent reconstruction of the plant, special attention was devoted to the effects of ozone dose and granulated activated carbon (GAC) filtration on the formation and behaviour of oxidation by-products (carbonyl compounds and bromate), as well as carbonaceous and nitrogenous chlorination by-products. For the oxidation of aromatic NOM moieties that absorb light at UV254, a lower ozone dose (1.0 g O3/m3) is sufficient, whereas to achieve a measurable reduction (about 20%) of total organic carbon, an ozone dose of 1.5 g O3/m3 is required. The content of carbonyl compounds in the water after ozonation increases relative to the content before oxidation treatment, and is up to 12 times higher in the case of aldehydes and up to 2 times higher in the case of carboxylic acids. Seasonal variations, including changes in temperature and the amount of precipitation, were also shown to affect the content of organic matter in the raw water, with slight effects on the quality of the treated water. In the winter, the organic matter content is slightly higher, meaning their transformation products aldehydes and carboxylic acids, are also higher during the winter than the summer.

Safety profile of temsirolimus in patients with metastatic renal cell carcinoma.

PURPOSE: Various targeted disease-specific therapeutics are currently approved, demonstrating a survival benefit over therapy with interferon-alpha (IFN-α) in patients with metastatic renal cell carcinoma (mRCC). Temsirolimus, a highly specific inhibitor of the mammalian target of rapamycin (mTOR), improves the overall and progression-free survival of high-risk patients with mRCC. The purpose of this study was to estimate the effects of temsirolimus on several laboratory parameters and to report the potential adverse events (AEs) in patients with mRCC. METHODS: This research was a controlled, open, prospective and partly retrospective randomized study that included 60 patients up to 65 years of age, divided into the experimental and control group, each containing 30 patients. Patients in the experimental group were treated with temsirolimus. The control group comprised patients in the same stage of disease, treated with IFN-α. The effect of therapy in both groups was monitored during the first year of administration. RESULTS: The overall incidence of AEs was 40% in both groups. Sixteen laboratory parameters were analyzed and the total number of deviations from the reference range was 263 in the experimental group and 229 in the control group. The total number of AEs regarding patient general clinical condition in the experimental group was 193 (asthenia 53.3%, urinary infection 43.3% and pyrexia 40%) and 175 in the control group (pyrexia 76.7%, asthenia 50% and tremor 50%). CONCLUSION: Monitoring the renal function parameters during the temsirolimus administration has proved that the therapy had no significant influence on the remaining kidney function. By evaluating the AEs we concluded that there was no significant difference in the number of AEs of all grades between the groups, while the laboratory parameters and physical status deterioration differed qualitatively.

Effects of a recombinant gene expression on ColE1-like plasmid segregation in Escherichia coli.

BACKGROUND: Segregation of expression plasmids leads to loss of recombinant DNA from transformed bacterial cells due to the irregular distribution of plasmids between the daughter cells during cell division. Under non-selective conditions this segregational instability results in a heterogeneous population of cells, where the non-productive plasmid-free cells overgrow the plasmid-bearing cells thus decreasing the yield of recombinant protein. Amongst the factors affecting segregational plasmid instability are: the plasmid design, plasmid copy-number, host cell genotype, fermentation conditions etc. This study aims to investigate the influence of transcription and translation on the segregation of recombinant plasmids designed for constitutive gene expression in Escherichia coli LE392 at glucose-limited continuous cultivation. To this end a series of pBR322-based plasmids carrying a synthetic human interferon-gamma (hIFNγ) gene placed under the control of different regulatory elements (promoter and ribosome-binding sites) were used as a model. RESULTS: Bacterial growth and product formation kinetics of transformed E. coli LE392 cells cultivated continuously were described by a structured kinetic model proposed by Lee et al. (1985). The obtained results demonstrated that both transcription and translation efficiency strongly affected plasmid segregation. The segregation of plasmid having a deleted promoter did not exceed 5% after 190 h of cultivation. The observed high plasmid stability was not related with an increase in the plasmid copy-number. A reverse correlation between the yield of recombinant protein (as modulated by using different ribosome binding sites) and segregational plasmid stability (determined by the above model) was also observed. CONCLUSIONS: Switching-off transcription of the hIFNγ gene has a stabilising effect on ColE1-like plasmids against segregation, which is not associated with an increase in the plasmid copy-number. The increased constitutive gene expression has a negative effect on segregational plasmid stability. A kinetic model proposed by Lee et al. (1985) was appropriate for description of E. coli cell growth and recombinant product formation in chemostat cultivations.