Heavy metal biosorption by biomass of Ochrobactrum anthropi producing exopolysaccharide in activated sludge

The removal of chromium, cadmium and copper, toxic metals of high environmental priority due to their toxicity, from dilute aqueous solutions has been studied in the present work, applying a dead exopolysaccharide producing bacterium, Ochrobactrum anthropi, isolated from activated sludge. Particularly, the effect of pH, metal concentration and the effects of contact time were considered. Optimum adsorption pH values of chromium(VI), cadmium(II) and copper(II) were 2.0, 8.0 and 3.0 respectively. Experimental results also showed the influence of initial metal concentration on the metal uptake for dried biomass. Both the Freundlich and Langmuir adsorption models were suitable for describing the short-term biosorption of chromium(VI), cadmium(II) and copper(II) by O. anthropi.     

TBARS,carnitine, and reduced glutathione levels in human bladder carcinoma

In this study, we investigated tissue levels of reduced glutathione (GSH) and carnitine as well as thiobarbituric acid reactive substances (TBARS, as a marker of lipid peroxidation) levels in bladder carcinoma and control group of patients. The average GSH, carnitine and TBARS levels for tumor group were respectively 7.11 ± 3.3 g/mg protein, 1.81 ± 0.39 nmol/mg protein, and 4.29 ± 3.2 mol/mg protein, versus 14.45 ± 4.11 g/mg protein, 2.14 ± 0.66 nmol/mg protein, and 2.3 ± 0.6 mol/mg protein for normal bladder tissues. Thus, tissue reduced glutathione levels (GSH) were significantly lower in patients as compared with the control group (p < 0.001) whereas average TBARS levels in the tumor group were found to be higher than those in control group. The average tissue carnitine levels in the patient group were found to be lower compared with the control group but the difference was not statistically significant (p > 0.05).     

A simple PCR/RFLP analysis can differentiate between Candida albicans,Aspergillus niger,and Aspergillus fumigatus

The clinical management of immunocompromised patients depends on the rapid identification of infectious agents such as fungal pathogens. The procedure described here for accomplishing this uses a sensitive polymerase chain reaction method, previously reported, combined with restriction-enzyme digestion to distinguish between Candida and Aspergillus species and to classify Aspergillus strains.     

Investigation of the relationship between nitric oxide metabolites' levels and adenosine deaminase activity in 7,12-dimethylbenz[a]anthracene induced mouse liver

7,12-Dimethylbenz[a]anthracene (7,12-DMBA) is a member of the polycyclic aromatic hydrocarbons with a severe carcinogenic effect. In this study, nitrate levels and ADA (Adenosine deaminase) activity in the liver homogenates of mice were measured and the effect of free radicals induced by 7,12-DMBA on inducible nitric oxide synthase (iNOS) and ADA activity were investigated. Antioxidant effects of melatonin were also compared. Three groups of mice were included in the study. The first served as control, the second was treated only with 7,12-DMBA and the third was treated with 7,12-DMBA + melatonin. Spectrophotometric methods were used at all measurements. Data were analyzed using Kruskal-Wallis Variance Analysis Test and Mann-Whitney U Test that were applied to the groups. The nitrate concentrations of mouse liver were as follows: 4.98 +/- 0.63 micro mol/L in the control group (n = 10), 8.23 +/- 1.58 micro mol/L (higher than control group, p < 0.05) in the 7,12-DMBA-treated group (n = 10), and 6.43 +/- 0.57 micro mol/L (lower than 7,12-DMBA-treated group, p < 0.05) in the 7,12-DMBA + melatonin-treated group (n = 10). Liver ADA activities were measured to be 4.14 +/- 0.674 U/L in the control group, 6.25 +/- 1.261 U/L (higher than control group, p < 0.05) in the 7,12-DMBA-treated group, and 4.93 +/- 0.916 U/L (lower than 7,12-DMBA-treated group, p < 0.05) in the 7,12-DMBA+melatonin-treated group. Differences between free nitrite levels were no significantly. Results demonstrated that nitrate levels and ADA activities were increased by means of free radicals induced by 7,12-DMBA. Melatonin inhibited the 7,12-DMBA induced increase that was observed in the activities of ADA enzyme and nitrate levels. It is concluded that determination of ADA activity and nitrate levels can be useful in the assessment of liver damage caused by toxic chemicals.     

Depurination of ribosomal RNA and inhibition of viral RNA translation by an antiviral protein of Celosia cristata

An antiviral protein (25 kD) isolated from leaves of Celosia cristata (CCP 25) was tested for depurination study on ribosomal RNA from yeast. Ribosomal RNA yielded 360 nucleotide base fragment after treatment with CCP 25 indicating that CCP 25 was a ribosome inactivating protein. CCP 25 also inhibited translation of brome mosaic virus (BMV) and pokeweed mosaic virus (PMV) RNAs in rabbit reticulocyte translation system. The radioactive assay showed that incorporation of [35S]-methionine was less in translation proteins of BMV nucleic acid when CCP 25 was added to translation system. This indicated that antiviral protein from Celosia cristata not only depurinated ribosomal RNA but also inhibited translation of viral RNA in vitro.     

A non-toxic pokeweed antiviral protein mutant inhibits pathogen infection via a novel salicylic acid-independent pathway

Pokeweed antiviral protein (PAP), a ribosome-inactivating protein isolated from Phytolacca americana, is characterized by its ability to depurinate the sarcin/ricin (S/R) loop of the large rRNA of prokaryotic and eukaryotic ribosomes. In this study, we present evidence that PAP is associated with ribosomes and depurinates tobacco ribosomes in vivo by removing more than one adenine and a guanine. A mutant of pokeweed antiviral protein, PAPn, which has a single amino acid substitution (G75D), did not bind ribosomes efficiently, indicating that Gly-75 in the N-terminal domain is critical for the binding of PAP to ribosomes. PAPn did not depurinate ribosomes and was non-toxic when expressed in transgenic tobacco plants. Unlike wild-type PAP and a C-terminal deletion mutant, transgenic plants expressing PAPn did not have elevated levels of acidic pathogenesis-related (PR) proteins. PAPn, like other forms of PAP, did not trigger production of salicylic acid (SA) in transgenic plants. Expression of the basic PR proteins, the wound-inducible protein kinase and protease inhibitor II, was induced in PAPn-expressing transgenic plants and these plants were resistant to viral and fungal infection. These results demonstrate that PAPn activates a particular SA-independent, stress-associated signal transduction pathway and confers pathogen resistance in the absence of ribosome binding, rRNA depurination and acidic PR protein production.