Effect of soil texture and its organic content on the efficacy of Trichoderma harzianum (MIAU 145 C) in controlling Meloidogyne javanica and stimulating the growth of kidney beans

The efficiency of Trichoderma harzianum (MIAU 145 C) in promoting kidney bean (cv. Goli) growth in different soil texture (sandy loam, loam and clay loam) and organic matter content (0.5 and 2% of leaf litter) was assessed in a factorial experiment in the absence of Meloidogyne javanica. In another factorial experiment, the effect of soil texture, soil organic content and control measure (no control, 10?ml of T. harzianum containing 10⁶ spore ml^?1 and 2?mg ai cadusafos kg^?1 soil) was determined on nematode-infected kidney bean’s growth, fungus controlling activity and M. javanica reproduction. Except for the shoot length, the fungus improved plant growth. Clay loam was not a proper soil type for the cultivation of kidney bean plants (even in the soil without nematode), but the plant grew better in sandy loam and loam soil. The presence of leaf litter in the soil enhanced plant growth, increased fungal efficiency and increased nematode reproduction. It seems that T. harzianum can activate the plant defence system in sandy loam soil. T. harzianum was more effective in sandy loam or loam soil containing 2% organic matter (leaf litter) and reduced the reproduction factor of the nematode in the tested soil textures equally to the chemical nematicide treatment.     

Lack of association between interleukin-13 gene polymorphisms (−1055 C/T and +2044 G/A) in Iranian patients with lung cancer

Lung cancer is one of the leading causes of death from cancer. Both immune cells and tumor cells play a key role in lung cancer immunity by secretion of cytokines and developing type-2 cell-mediated immune response. IL-13 is an immunoregulatory cytokine affecting tumor immunosurveillance by deviation of immune response from Th1 to Th2. In the present study we sought to determine the association of single nucleotide polymorphisms (SNPs) of IL-13 gene at positions +2044 (G/A) and −1055 (C/T) and lung cancer. One hundred forty one patients and 113 controls were recruited; control group was subdivided into smoker and nonsmoker individuals for serum detection. Genotyping was carried out by PCR-RFLP assay and IL-13 detection by ELISA method. No statistically significant difference was found in the frequency of genotypes, alleles, and haplotypes at positions +2044 (G/A) and −1055 (C/T) of IL-13 gene between lung cancer patients and controls. Serum level of IL-13 was not detectable in both groups. The results of this study reveal that although +2044 (G/A) and −1055 (C/T) SNPs in IL-13 are implicated in some pulmonary processes, they do not confer susceptibility to lung cancer in Iranian population.     

Evaluation of antigenotoxicity effects of umbelliprenin on human peripheral lymphocytes exposed to oxidative stress

The protective properties of a prenylated coumarin, umbelliprenin (UMB), on the human lymphocytes DNA lesions were tested. Lymphocytes were isolated from blood samples taken from healthy volunteers. DNA breaks and resistance to H₂O₂-induced damage were measured using a single-cell microgel electrophoresis technique under alkaline conditions (comet assay). Human lymphocytes were incubated in UMB (10, 25, 50, 100, 200, and 400 μM) alone or a combination of different concentrations of UMB (10, 25, 50, 100, 200, and 400 μM) and 25 μM H₂O₂. Untreated cells, ascorbic acid (AA; 25, 50, 100, 200, and 400 μM) and H₂O₂ (25 μM) were considered as negative control, positive control, and the standard antioxidant agent for our study, respectively. Single cells were analyzed with “TriTek Cometscore version 1.5” software. The DNA damage was expressed as percent tail DNA. UMB exhibited a concentration-dependent increase in protection activity against DNA damage induced by 25 μM H₂O₂ (from 67.28% to 39.17%). The antigenotoxic activity of AA, in the range 0–50 μM, was greater than that of UMB. However, no significant difference (p > 0.05) in the protective activity was found between UMB and AA at concentrations of approximately higher than 50 μM.     

Mucor hiemalis: a new source for uricase production

Summary One hundred and sixty-five strains of microorganisms with the ability to grow in a medium containing uric acid as a major source of nitrogen were isolated from soil samples during a screening program. Among them, a zygomycete fungus with well-developed columellae was recognized to produce high levels of the enzyme in a short time. Classification of the isolated fungus was carried out according to the morphological and culture characteristics of the organism, and it was identified as Mucor hiemalis. The fungus was able to produce an intracellular urate oxidase in a fermentation medium mainly containing uric acid. Optimized composition of the medium consisted of (l⁻¹ of distilled water) uric acid, 7.0 g; maltose, 6.0 g; Vogel stock solution, 20 and 1 ml of 0.5 M copper sulphate. The optimum pH and temperature for uricase production in the optimized medium were pH 6 and 30 °C, respectively.     

The application of musculoskeletal modeling to investigate gender bias in non-contact ACL injury rate during single-leg landings

The central tenet of this study was to develop, validate and apply various individualised 3D musculoskeletal models of the human body for application to single-leg landings over increasing vertical heights and horizontal distances. While contributing to an understanding of whether gender differences explain the higher rate of non-contact anterior cruciate ligament (ACL) injuries among females, this study also correlated various musculoskeletal variables significantly impacted by gender, height and/or distance and their interactions with two ACL injury-risk predictor variables; peak vertical ground reaction force (VGRF) and peak proximal tibia anterior shear force (PTASF). Kinematic, kinetic and electromyography data of three male and three female subjects were measured. Results revealed no significant gender differences in the musculoskeletal variables tested except peak VGRF (p = 0.039) and hip axial compressive force (p = 0.032). The quadriceps and the gastrocnemius muscle forces had significant correlations with peak PTASF (r = 0.85, p < 0.05 and r = ? 0.88, p < 0.05, respectively). Furthermore, hamstring muscle force was significantly correlated with peak VGRF (r = ? 0.90, p < 0.05). The ankle flexion angle was significantly correlated with peak PTASF (r = ? 0.82, p < 0.05). Our findings indicate that compared to males, females did not exhibit significantly different muscle forces, or ankle, knee and hip flexion angles during single-leg landings that would explain the gender bias in non-contact ACL injury rate. Our results also suggest that higher quadriceps muscle force increases the risk, while higher hamstring and gastrocnemius muscle forces as well as ankle flexion angle reduce the risk of non-contact ACL injury.     

Generation of an enriched pool of DNA aptamers for an HER2-overexpressing cell line selected by Cell SELEX

Overexpression of human epidermal growth factor receptor 2 (HER2) occurs in a large percentage of breast cancers. Monoclonal antibodies targeting HER2 are vastly used for both diagnostic and therapeutic aims. However, identifying a new molecular probe against HER2 with improved diagnostic and therapeutic features is of great importance. In this report, we have applied the cell systematic evolution of ligands by exponential enrichment (SELEX) strategy for 16 selection rounds to generate an enriched pool of aptamers that specifically recognize the HER2 positive cell line. During the Cell SELEX procedure, a human HER2-overexpressing breast cancer cell line and a human HER2 negative breast cancer cell line were used. Our results reveal that polymerase chain reaction (PCR) amplification of random DNA libraries and the selected single-stranded DNA pool in different Cell SELEX rounds are different from what we expect from PCR amplification of homologous DNA. Our results also confirmed previous studies describing positive HER2 status of SK-BR3 and the absence of the HER2 expression in the MDA-MB468. We also developed a new method, Cell enzyme-linked assay, to monitor the enrichment of aptamers in a given round of Cell SELEX. This method would also be useful in other experiments using live cell enzyme-linked immunosorbent assay on adherent cells.     

Thionine increases electricity generation from microbial fuel cell using Saccharomyces cerevisiae and exoelectrogenic mixed culture

Microbial fuel cells (MFCs) have been shown to be capable of clean energy production through the oxidation of biodegradable organic waste using various bacterial species as biocatalysts. In this study we found Saccharomyces cerevisiae, previously known electrochemcially inactive or less active species, can be acclimated with an electron mediator thionine for electrogenic biofilm formation in MFC, and electricity production is improved with facilitation of electron transfer. Power generation of MFC was also significantly increased by thionine with both aerated and non-aerated cathode. With electrochemically active biofilm enriched with swine wastewater, MFC power increased more significantly by addition of thionine. The optimum mediator concentration was 500 mM of thionine with S. cerevisae in MFC with the maximum voltage and current generation in the microbial fuel cell were 420 mV and 700 mA/m(2), respectively. Cyclic voltametry shows that thionine improves oxidizing and reducing capability in both pure culture and acclimated biofilm as compared to non-mediated cell. The results obtained indicated that thionine has great potential to enhance power generation from unmediated yeast or electrochemically active biofilm in MFC.     

First report of a bifunctional chitinase/lysozyme produced by Bacillus pumilus SG2

Bacillus pumilus SG2 isolated from high salinity ecosystem in Iran produces two chitinases (ChiS and ChiL) and secretes them into the medium. In this study, chiS and chiL genes were cloned in pQE-30 expression vector and were expressed in the cytoplasm of Escherichia coli strain M15. The recombinant proteins were purified using Ni-NTA column. The optimum pH and optimum temperature for enzyme activity of ChiS were pH 6, 50°C; those of ChiL were pH 6.5, 40°C. The purified chitinases showed antifungal activity against Fusarium graminearum, Rhizoctonia solani, Magnaporthe grisea, Sclerotinia sclerotiorum, Trichoderma reesei, Botrytis cinerea and Bipolaris sp. Moreover, purified ChiS was identified as chitinase/lysozyme, which are capable of degrading the chitin component of fungal cell walls and the peptidoglycan component of cell walls with many kinds of bacteria (Xanthomonas translucens pv. hordei, Xanthomonas axonopodis pv. citri, Bacillus licheniformis, E. coli C600, E. coli TOP10, Pseudomonas aeruginosa and Pseudomonas putida). Strong homology was found between the three-dimensional structures of ChiS and a chitinase/lysozyme from Bacillus circulans WL-12. This is the first report of a bifunctional chitinase/lysozyme from B. pumilus.