DNA interaction studies of a platinum(II) complex containing L-histidine and 1,10-phenanthroline ligands

The aim of this study was developing coordination complexes that can be used as inorganic medicinal agents. The water soluble [Pt(phen)(His)]NO(3)·3H(2)O complex in which phen=1,10-phenantheroline and His=L-histidine was synthesized and characterized using physicochemical methods. Binding interaction of this complex with calf thymus (CT) DNA was investigated by emission, absorption, circular dichroism, and viscosity measurement techniques. Upon addition of CT-DNA, changes were observed in the characteristic ultraviolet-visible (UV-Vis) bands (hypochromism) of the complex. The complex binds to CT-DNA in an intercalative mode. The calculated binding constant, K(b), was 8 ± 0.2 × 10(4) M(-1). In addition, circular dichroism (CD) study showed that the phenanthroline ligand was inserted between the base pair stack of the double-helical structure of DNA. Also, the fluorescence spectral characteristics showed an increase in fluorescence intensity of the platinum complex in the presence of increasing amounts of DNA solution. The experimental results showed that the platinum complex binds to DNA via intercalative and hydrogen bonding mode.     

Effects of road-traffic pollutants (lead and cadmium) on tree fine-roots along a motor road

The aim of this investigation was to study the effects of lead and cadmium pollutants from road traffic on fine roots and mycorrhiza and their accumulation in soil. The effects of salt and phosphorus, calcium and pH were furthermore included in the study. Soil sampling was carried out in a Norway spruce (Picea abies (L.) Karsten stand along the European road E18 in the neighbourhood of Västerås. Cylindrical soil samples were taken along two parallel lines at a distance of 20 and 200 m from the about 10 m open area on both sides of the road. There were more root tips per soil core in the FH-horizon 200 m from the road than near the road. The amount of fine roots (dry weight and length) was furthermore higher in the FH-layer in the forest than adjacent to the road. The estimated pH was higher in the FH- and mineral soil horizon near the road than in the forest. The lead concentration was highest in the FH-layer near the road, in spite of the high pH and calcium concentration in the soil. The lead and cadmium concentrations in dead fine-roots were higher close to the road than in the forest. In relation to lead the related cadmium concentration in the soil was very low.     

Estimating Root Longevity at Sites with Long Periods of Low Root Mortality

Minirhizotron technique is capable of providing median root longevity. The use of the median longevity might overestimate root longevity if the distribution of survival times is very skewed or irregular, as is the case at sites where root mortality is very low during the long winter. In this paper we illustrate the case theoretically and compare that with field observation in northern Sweden to show an alternative procedure for such sites. Hypothetical root cohorts were constructed to investigate and show some technical problems with estimating median root longevity at a Swedish northern site where root mortality is very low during long winter time (8 months), and to investigate whether these problems could be overcome by discarding winter time from the survival analysis and include only the growing season in which the roots are at risk of mortality. Authentic root data, gathered in a minirhizotron study at such a site, were analysed on a whole year basis and on season basis. By analysing longevity based only on the season when there is a risk for root death, the median longevity became a more reliable estimate of the true mean longevity. When this method was applied to root data from northern Sweden, the estimated root longevity in different treatments became between 17% lower and 8% higher compared to the longevity estimated on a whole year basis.We conclude that the reliability of the median longevity as an estimate of the true mean longevity can be increased by basing the survival analysis only on the parts of the year when fine roots are at risk of mortality at sites with long winter and low root mortality.     

Biodegradation kinetics of trans-4-methyl-1-cyclohexane carboxylic acid

Naphthenic acids are a complex mixture of organic compounds which naturally occur in crude oil. Low molecular weight components of the naphthenic acids are known to be toxic in aquatic environments and there is a need to better understand the factors controlling the kinetics of their biodegradation. In this study, a relatively low molecular weight naphthenic acid compound (trans-isomer of 4-methyl-1-cyclohexane carboxylic acid) and a microbial culture developed in our laboratory were used to study the biodegradation of this naphthenic acid and to evaluate the kinetics of the process in batch cultures. The initial concentration of trans-4-methyl-1-cyclohexane carboxylic acid (50–750 mg l⁻¹) did not affect the maximum specific growth rate of the bacteria at 23°C (0.52 day⁻¹) to the maximum biodegradable concentration (750 mg l⁻¹). The maximum yield observed at this temperature and at a neutral pH was 0.21 mg of biomass per milligram of substrate. Batch experiments indicated that biodegradation can be achieved at low temperatures; however, the biodegradation rate at room temperature (23°C) and neutral pH was 5 times faster than that observed at 4°C. Biodegradation at various pH conditions indicated a maximum specific growth rate of 1.69 day⁻¹ and yield (0.41 mg mg⁻¹) at a pH of 10.     

The effect of diabetes mellitus on pharmacokinetics,pharmacodynamics and adverse drug reactions of anticancer drugs

Diabetes mellitus (DM) and cancer are global problems carrying huge human, social, and economic impact. Type 2 diabetes (T2DM) is associated with an increased risk for a number of cancers, including breast, pancreatic, and liver cancer. Moreover, adverse drug reactions are higher in paitents with cancer with T2DM compared to cancer patients without T2DM. Cellular mechanisms of hyperglycemia and chemotherapy efficacy may be different depending upon the particular cancer type and the condition of the patient. This review evaluates the effect of DM on the pharmacokinetic, pharmacodynamic, and adverse drug reactions of commonly used anticancer drugs such as cisplatin, methotrexate, paclitaxel, doxorubicin, and adriamycin in both clinical and animal models. A literature search was conducted in scientific databases including Web of Science, PubMed, Scopus, and Google Scholar including the relevant keywords. The results of the effectiveness of anticancer therapies in patients with DM are, however, inconsistent because DM can negatively impact multiple diverse entities including nerves and vascular structures, insulin-like growth factor 1, the function of the innate immune system, drug pharmacokinetics, the expression levels of hepatic CYP₄₅₀, Mdr _1b and enzymes that then lead to drug toxicity. However, in a few circumstances, DM led to attenuation of the toxicity of anticancer drugs secondary to attenuation of the energy-dependent renal uptake process. Overall, the impact of DM on patients with cancer is variable because of the diverse types of cancers and the spectrum of anticancer drugs. With respect to the evidence for cancer involvement in DM pathophysiology and the response to anticancer treatment in patients with DM, many questions still remain and further clinical trials are needed.     

PML-Regulated Mitochondrial Metabolism Enhances Chemosensitivity in Human Ovarian Cancers

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Characterisation of Arthrobacter sp. S1 that can degrade α and β-haloalkanoic acids isolated from contaminated soil

A bacterium identified as Arthrobacter sp. S1 by 16S rRNA was isolated from contaminated soil. This is the first reported study that Arthrobacter could utilize both α-halocarboxylix acid (αHA) [2,2-dichloropropionic acid (2,2-DCP) and D,L-2-chloropropionic acid (D,L-2-CP)] and β-halocarboxylix acid (βHA) [3-chloropropionic acid (3CP)] as sole source of carbon with cell doubling times of 5?±?0.2, 7?±?0.1, and 10?±?0.1 h, respectively. More than 85 % chloride ion released was detected in the growth medium suggesting the substrates used were utilized. To identify the presence of dehalogenase gene in the microorganism, a molecular tool that included the use of oligonucleotide primers specific to microorganisms that can grow in halogenated compounds was adapted. A partial putative dehalogenase gene was determined by direct sequencing of the PCR-amplified genomic DNA of the bacterium. A comparative analysis of the deduced amino acid sequence data revealed that the amino acid sequence has a low identity of less than 15 % to both group I and group II dehalogenases, suggesting that the current putative dehalogenase amino acid sequence was completely distinct from both α-haloacids and β-haloacids dehalogenases. This investigation is useful in studying the microbial populations in order to monitor the presence of specific dehalogenase genes and to provide a better understanding of the microbial populations that are present in soil or in water systems treating halogenated compounds.     

Biodegradation of surrogate naphthenic acids and electricity generation in microbial fuel cells: bioelectrochemical and microbial characterizations

Bioprocess and Biosystems Engineering - Waters contaminated with naphthenic acids (NAs) and associated tailings are one of the major environmental challenges associated with the processing of oil...