Serum copper and zinc levels and copper/zinc ratio in patients with breast cancer

Serum copper, zinc levels, and the Cu/Zn ratio were evaluated in 31 patients with breast cancer and 35 healthy controls. Copper and zinc were determined by atomic absorbtion spectrophotometry. The mean serum copper level and the mean Cu/Zn ratio in patients with breast cancer were significantly higher than the control group (p<0.001 andp<0.001). In addition, the mean serum zinc level in patients with breast cancer was significantly lower than the control group (p<0.001). Neither serum copper and zinc levels nor the Cu/Zn ratio were of value in discriminating of the disease activity and severity. Interestingly, the Cu/Zn ratio in premenopausal patients was higher than postmenopausal patients (p<0.05) and this was not related to age. The further combined biological and epidemiological studies are necessary to investigate the roles of copper and zinc in breast cancer.     

Health of the Land,Health of the People: A Case Study on Gwich’in Berry Harvesting in Northern Canada

Many Aboriginal groups, in northern Canada and elsewhere, recognize the strong relationship between the health and well-being of people and environment. Western science, including theory and literature related to forest ecosystem management, has been slow to recognize the complex and diverse values that Aboriginal people associate with their lands and resources. Through case study research on the berry-harvesting practices of Gwich’in women from the community of Fort McPherson, Northwest Territories, Canada, we investigated the values that Teetl’it Gwich’in women associate with the land or nan kak. Nine different values, as well as a set of detailed measures, were identified during the research, including individual preference and well-being, family well-being, social connectivity, cultural continuity, land and resource use, stewardship, self-government, and spirituality. The commercial value of berries was not identified as important to women. This interdisciplinary research has the potential to contribute to several bodies of literature including that on social-ecological systems.     

Adsorbent supplemented biological treatment of pre-treated landfill leachate by fed-batch operation

Biological treatment of landfill leachate usually results in low COD removals because of high chemical oxygen demand (COD), high ammonium-N content and presence of toxic compounds. Coagulation-flocculation with lime addition and air stripping of ammonia were used as pre-treatment in this study in order to improve biological treatability of the leachate. Pre-treated leachate was subjected to adsorbent supplemented biological treatment in an aeration tank operated in fed-batch mode. COD and NH(4)-N removal performances of powdered activated carbon (PAC) and powdered zeolite (PZ) were compared during biological treatment. Adsorbent concentrations varied between 0 and 5 gl(-1). Percent COD and ammonium-N removals increased with increasing adsorbent concentrations. Percent COD removals with PAC addition were significantly higher than those obtained with the zeolite. However, zeolite performed better than the PAC in ammonium-N removal from the leachate. Nearly 87% and 77% COD removals were achieved with PAC and zeolite concentrations of 2 gl(-1), respectively. Ammonium-N removals were 30% and 40% with PAC and zeolite concentrations of 5 gl(-1), respectively at the end of 30 h of fed-batch operation.     

Modulation of photosynthetic electron transport in the absence of terminal electron acceptors: characterization of the rbcL deletion mutant of tobacco

Tobacco rbcL deletion mutant, which lacks the key enzyme Rubisco for photosynthetic carbon assimilation, was characterized with respect to thylakoid functional properties and protein composition. The Delta rbcL plants showed an enhanced capacity for dissipation of light energy by non-photochemical quenching which was accompanied by low photochemical quenching and low overall photosynthetic electron transport rate. Flash-induced fluorescence relaxation and thermoluminescence measurements revealed a slow electron transfer and decreased redox gap between Q(A) and Q(B), whereas the donor side function of the Photosystem II (PSII) complex was not affected. The 77 K fluorescence emission spectrum of Delta rbcL plant thylakoids implied a presence of free light harvesting complexes. Mutant plants also had a low amount of photooxidisible P700 and an increased ratio of PSII to Photosystem I (PSI). On the other hand, an elevated level of plastid terminal oxidase and the lack of F0 'dark rise' in fluorescence measurements suggest an enhanced plastid terminal oxidase-mediated electron flow to O2 in Delta rbcL thylakoids. Modified electron transfer routes together with flexible dissipation of excitation energy through PSII probably have a crucial role in protection of PSI from irreversible protein damage in the Delta rbcL mutant under growth conditions. This protective capacity was rapidly exceeded in Delta rbcL mutant when the light level was elevated resulting in severe degradation of PSI complexes.     

Kinetics of sequential nitrification and denitrification processes

Kinetics of nitrification and denitrification of synthetic wastewater was investigated by using two reactors in series. An activated sludge unit was used for nitrification followed by a downflow biofilter for denitrification. Glucose solution was fed to the denitrification column to supply carbon source. Reactors were operated at different operating conditions and data were collected for determination of kinetic constants. Experimental data indicated that nitrification and denitrification kinetics followed Monod kinetics. By using the experimental data, kinetic constants for nitrification were determined as k = 1.15 d(-1), K(N) = 5.14 mg/l, Y = 0.34 mgX/mgN and b = -0.021 d(-1). Similarly, kinetic constants for denitrification were determined as k = 0.23 d(-1) and K(DN) = 0.27 mg/l. Rates of nitrification and denitrification increased with increasing nitrogen loading rate.     

Biochemical characterization and DNA repair pathway interactions of Mag1-mediated base excision repair in Schizosaccharomyces pombe

The Schizosaccharomyces pombe mag1 gene encodes a DNA repair enzyme with sequence similarity to the AlkA family of DNA glycosylases, which are essential for the removal of cytotoxic alkylation products, the premutagenic deamination product hypoxanthine and certain cyclic ethenoadducts such as ethenoadenine. In this paper, we have purified the Mag1 protein and characterized its substrate specificity. It appears that the substrate range of Mag1 is limited to the major alkylation products, such as 3-mA, 3-mG and 7-mG, whereas no significant activity was found towards deamination products, ethenoadducts or oxidation products. The efficiency of 3-mA and 3-mG removal was 5–10 times slower for Mag1 than for Escherichia coli AlkA whereas the rate of 7-mG removal was similar to the two enzymes. The relatively low efficiency for the removal of cytotoxic 3-methylpurines is consistent with the moderate sensitivity of the mag1 mutant to methylating agents. Furthermore, we studied the initial steps of Mag1-dependent base excision repair (BER) and genetic interactions with other repair pathways by mutant analysis. The double mutants mag1 nth1, mag1 apn2 and mag1 rad2 displayed increased resistance to methyl methanesulfonate (MMS) compared with the single mutants nth1, apn2 and rad2, respectively, indicating that Mag1 initiates both short-patch (Nth1-dependent) and long-patch (Rad2-dependent) BER of MMS-induced damage. Spontaneous intrachromosomal recombination frequencies increased 3-fold in the mag1 mutant suggesting that Mag1 and recombinational repair (RR) are both involved in repair of alkylated bases. Finally, we show that the deletion of mag1 in the background of rad16, nth1 and rad2 single mutants reduced the total recombination frequencies of all three double mutants, indicating that abasic sites formed as a result of Mag1 removal of spontaneous base lesions are substrates for nucleotide excision repair, long- and short-patch BER and RR.     

Effects on rat testes of the thiosemicarbazone derivative Schiff base (4-(1-phenylmethylcyclobutane-3-yl)-2-(2-hydroxybenzylidenehydrazino)thiazole) and its cadmium(II) complex

The aim of this study was to investigate structural and biochemical changes in testes of rats treated with the thiosemicarbazone derivative thiazole ring Schiff base, (4-(1-phenyl-methylcyclobutane-3-yl)-2-(2-hydroxybenzylidene-hydrazino) thiazole (L), and its Cd(II) complex (CdL(2)). The animals were divided into three groups. Group I was designated as control. The rats in groups II and III were injected subcutaneously with L or CdL(2) respectively at 150-mg kg(-1) doses at 3-day intervals for 15 days. At the end of the study, blood samples were collected for biochemical analysis, and testes were removed for histological examinations. Serum levels of vitamin A, E and MDA of the L-injected group were similar to the control group. While CdL(2) treatment decreased serum vitamin A and E levels, it increased the MDA level compared to other groups. Histologically, the testes structures of L-treated animals were similar to the control. Spermatogenic cells in seminiferous tubules of CdL(2)-treated animals displayed necrosis. Nuclei of spermatogonia and primary spermatocytes were pyknotic and heterochromatic. Homogenous pink particles were present in place of the spermatids. The interstitial areas were oedematous and intertubular vessels were plugged. In conclusion, the present results indicate that L does not cause biochemical and morphological alterations, but its Cd(II) complex has degenerative effects in normal rat testes.     

Decolorization of textile dyestuffs by a mixed bacterial consortium

A mixed anaerobic bacterial culture decolorized Drimaren Orange K-GL, Everzol Red RBN and Everdirect Supra Yellow PG dyestuffs at 200 mg dyestuff l^–1 over 24 h. Improved performance with complete decolorization within 24 h was achieved by incubation with 5 g yeast extract l^–1 compared to glucose, lactose and sucrose though 50 mg yeast extract l^–1 supplemented with 5 g lactose l^–1 or 5 g sucrose l^–1 also resulted in complete decolorization within 24 h.     

Characterization and biological treatment of pickling industry wastewater

Pickling industry wastewaters present unique difficulties in biological treatment because of high salt content (3–6% salt). Conventional activated sludge cultures disintegrate or loose microbial activity as a result of plasmolysis at salt concentrations above 1%. In order to overcome adverse effects of salt in pickling wastewater, salt tolerant bacteria (Halobacter halobium) was added to activated sludge culture and used in biological treatment of the wastewater in an activated sludge unit. After characterization and nutrient balancing of the wastewater, an activated sludge unit was used in laboratory to investigate the effects of major process variables such as sludge age and hydraulic residence time on performance of the system. Single stage and two stage activated processes were used for the treatment of the pickling wastewater. More than 95% of COD removal was obtained with a single stage process at a sludge age of θ_c=10?d and hydraulic residence time of θ_H=30?h. Similar results were obtained with the two stage process, when sludge ages and hydraulic residence times for each stage were θ_c1=θ_c2=10?d, and θ_H1=θ_H2=15?h, respectively. Kinetic coefficients were determined and the design equations were developed by using the experimental data.