Heavy metal contamination of water and fish in peri-urban dams around Bulawayo,Zimbabwe

Urban effluents are significant sources of heavy metal pollution in fresh water. Metal contamination in dams around the city of Bulawayo, Zimbabwe, were monitored during October 2014 to assess ecological and public health risks. Heavy metals were measured in water, sediment and fish in dams located downstream of effluent discharge zones in Bulawayo and were compared to those in a pristine upstream dam. Water conductivity indicated pollution of downstream dams. Levels of lead (0.13–0.28 ppm) and cadmium (0.02–0.06 ppm) in water from downstream dams exceeded WHO safe limits for drinking water. Cadmium levels in polluted dams also exceeded the safe limit for agricultural use. Sediments of effluent-polluted dams had metal contamination factors ranging from 8.8 to 31.2 relative to the control, and fish from the dams had higher metal content and were unfit for human consumption. Metal levels were also measured along an urban stream to establish the sources of metals. The city’s industrial zone had the highest levels of metals, suggesting that industrial effluents were major sources of contamination. The environmental consequences and human health risks of the pollution of peri-urban water bodies from urban effluents are discussed.     

Interactions of Cd with Zn, Cu, Mn and Fe for lettuce (Lactuca sativa L.) in hydroponic culture

Abstract. The effect and accumulation of cadmium (Cd) in lettuce grown by means of the hydroponic technique was investigated by multivariate analysis, and was found to be affected by the concentration of other trace elements. Particularly iron acted in a strongly antagonistic way against Cd. Consequently, no absolute toxicity limits for Cd can be drawn without considering other trace elements.     

Expression of senescence-associated genes in multipotent mesenchymal stromal cells during long-term cultivation at various hypoxic levels

The expression of several genes which functions are associated with cellular senescence was analyzed in multipotent mesenchymal stromal cells during long-term cultivation at different oxygen levels (20, 5, and 1%) using the RT² Profiler? PCR Array Human Cellular Senescence system (Qiagen, United States). It was established that replicative senescence processes develop most actively in the cells cultured under the standard conditions (20% O₂). The most significant changes were observed in the expression of CCND1, ID1, IGF1, PIK3CA, and SERPINE1 genes.     

The use of pharmacological screening for characterizing the toxicity of pertussis vaccines

The influence of pertussis preparations, introduced by oral and parenteral routes, on the detoxifying function of the liver and the state of the nervous system of the animals was studied by methods used in pharmacology and toxicology. The use of these methods made it possible to find out side effects produced by corpuscular pertussis vaccine, introduced parenterally, on the detoxifying function of the liver and the state of the nervous system of the animals. The negative influence on the nervous system was more pronounced after the injection of the commercial adsorbed diphtheria-pertussis-tetanus vaccine used in this investigation than after the injection of pertussis monovaccine. The oral administration of corpuscular pertussis vaccine exerted no negative influence on the above-mentioned body functions of the animals.     

Antibodies to synthetic fragments of nucleophosmin for the specific detection of its monomeric and oligomeric forms

Immunoactive fragments corresponding to the N-terminal (19–36) and C-terminal (283–294) regions of the NPM1.1 isoform of nucleophosmin and their shortened fragments were chosen and synthesized. Rabbits were immunized with free full-size peptides and their protein conjugates. Antibodies produced against the 19–36 and 283–294 peptides were purified by affinity chromatography on cyan-bromide activated sepharose that was preliminary conjugated with the synthetic peptides. An analysis of immunoblots of lysates of the HeLa and Ramos cells demonstrated that the antibodies produced against the 19–36 peptide detected the monomeric form of nucleophosmin, whereas the antibodies against the 283–294 peptide predominantly revealed its oligomeric form. It was established by immunocytochemical analysis that the antibodies induced by the 19–36 peptide stained the nucleoplasm and perinuclear space of the cytoplasm of the HeLa and Ramos cells, but did not stain the nucleoli, while the antibodies against the 283–294 peptide stained only the nucleoli of the same cells. On the basis of these results, one could propose that the monomeric and oligomeric forms of nucleophosmin were located in the nucleoplasm and nucleoli of the examined cells, respectively. Thus, antibodies which can predominantly detect monomeric and oligomeric forms of nucleophosmin were produced for the first time. An analysis of the monomeric-oligomeric state and the localization of the nucleophosmin in tumor cells could be performed using these antibodies.     

State of oncomarker protein B23/nucleophosmin in HeLa cells

Western blot after SDS-PAGE for protein separation showed two immunoreactive bands corresponding to monomers (38–40 kDa) and oligomers (210–230 kDa) of nucleophosmin in HeLa cell lysates. Decreasing the buffer ionic strength during the incubation of cells and nuclei destabilized these oligomers. We also showed the existence of two B23/nucleophosmin pools in nuclei of HeLa cells with different sensitivity to hypotonic buffer treatment: one extractable from the nucleus and the other non-extractable and tightly bound to the nucleus. A detailed structural analysis of the extractable B23 pool was carried out: two closely related nucleophosmin isoforms (B23.1 and B23.2) were identified as a result of analysis of C-terminal amino acid sequences using carboxypeptidase hydrolysis; the N-termini of both isoforms are blocked by an acetyl group. As a result of sequencing of the deacetylated proteins, it has been established that the N-terminal amino acid sequence of nucleophosmin in these preparations is truncated by nine amino acid residues and the acetylated residue is Ser. The truncated monomer of nucleophosmin (represented only by the extractable part of the protein) on addition of magnesium ions to low ionic strength buffer or increase in buffer ionic strength was shown to form oligomers with molecular weights (210–230 kDa) similar to those revealed in the total cell lysate. It should be noted that the set of oligomers in this case differs from the one in total cell lysate. Our strategy of characterization of B23 forms for HeLa cells can be applied for other tumor cells.     

Seed characteristics and fatty acid composition of castor (<i>Ricinus communis</i> L.) varieties in Northeast China

Oil content and fatty acid composition were investigated on 12 castor varieties and strains by using the soxhlet extraction method and capillary gas chromatography. This was made to provide a reference and theoretical basis for castorbean breeding with high oil content, determine variability of seed compounds for breeding purposes, and broaden chemical material choices. Results revealed that crude fat percentage in seeds ranged from 18.91 to 35.84% with an average of 25.91%; the absolute content of ricinoleic acid varied between 171.65 g/kg and 314.03 g/kg with an average of 222.43 g/kg, and kernel crude fat percentage was between 24.28 and 46.97% with an average of 34.30%. All these study variables were highest in the 2129 strain. The percentage of ricinoleic acid in crude fat was between 83.85 to 87.62%, and the highest value was found in the zhebi4 accession. The other fatty acids appeared in small concentrations, and showed small amplitude: 1.12 to 1.61%, 1.21 to 1.61%, 3.53 to 4.80%, 5.35 to 6.38%, 0.52 to 0.79%, 0.05 to 0.08% and 0.43 to 0.55%, for palmitic, stearic, oleic, linolic, linolenic, arachidic, and arachidonic acids, respectively. One hundred seed weight was determined for each accession. One hundred seed weight ranged from 25.7 g to 34.0 g with an average of 29.9 g. There was a significant correlation between seed weight and oil content, but the correlation value was low (r=0.51). Cluster analysis by SSPS based on the content of fatty acid composition revealed that the accessions were divided into three independent clusters. These findings will clearly provide useful information for further research in breeding and utilization of castor oil.