The polymorphisms of the tumor suppressor gene p53 in exon 4 (p53 BstUI) and in intron 6 (p53 MspI) have been suggested to be associated with the genetically determined susceptibility in diverse types of human cancer. In our hospital-based case-control study, we examined the allele and genotype incidence of these polymorphisms as well as their haplotype combinations in 60 brain tumor patients (27 males and 33 females) and 183 controls without malignancies. The genotype characteristics were determined by the PCR-based RFLP method using DNA extracted from peripheral blood. In this study we show that the p53 BstUI and the p53 MspI polymorphisms are not associated with increased risk of brain tumors. Thus, we conclude that the p53 BstUI and the p53 MspI polymorphic sites within the tumor suppressor gene p53 do not represent genetic determinants of susceptibility to brain tumors., E. Biroš, I. Kalina, A. Kohút, E. Bogyiová, J. Šalagovič, I. Šulla., and Obsahuje bibliografii
Cytochrome P450s (P450s) involved in insecticide resistance reduce the efficacy of insecticide-based vector control by rendering vector control ineffective. They are recorded in many species of vectors and have various constitutive and insecticide induction profiles. In this study, the isolation and prediction of the structure of a P450 from a strain of Aedes aegypti originating from Malaysia is reported. Quantitative mRNA expression of this gene and a previously reported P450, CYP4H28v2, in the developmental stages of the mosquito after exposure to sub-lethal concentrations of insecticides is also reported. The isolated P450, CYP4H31v2, is an allelic variant of CYP4H31 and contains several conserved motifs of P450s. The secondary structure of the protein is mostly made up of alpha helices and random coils. The tertiary structure was generated using homology modeling and was of good quality based on structure validation using protein structure assessment tools. CYP4H28v2 and CYP4H31v2 were differentially expressed in the developmental stages of the vector, with a significantly increased expression in adult males. The genes were significantly over-expressed in larvae exposed to deltamethrin and permethrin for 6 h. In the DDT-treated larvae, only CYP4H31v2 was significantly over-expressed after a 6 h exposure. Under-expression of the genes was predominant in larvae treated with the organophosphates malathion and temephos. Though the functions of these P450s are unknown, their response to induction by exposure to insecticides indicates the likely involvement of these genes in insecticide tolerance. and Fatma M. A. El-Garj, Mustafa F.F. Wajidi, Silas W. Avicor.
Leaf area estimation is an important biometrical observation recorded for evaluating plant growth in field and pot experiments. In this study, conducted in 2009, a leaf area estimation model was developed for aromatic crop clary sage (Salvia sclarea L.), using linear measurements of leaf length (L) and maximum width (W). Leaves from four genotypes of clary sage, collected at different stages, were used to develop the model. The actual leaf area (LA) and leaf dimensions were measured with a Laser Area meter. Different combinations of prediction equations were obtained from L, W, product of LW and dry mass of leaves (DM) to create linear (y = a + bx), quadratic (y = a + bx + cx2), exponential (y = aebx), logarithmic (y = a + bLnx), and power models (y = axb) for each genotype. Data for all four genotypes were pooled and compared with earlier models by graphical procedures and statistical measures viz. Mean Square Error (MSE) and Prediction Sum of Squares (PRESS). A linear model having LW as the independent variables (y = -3.4444 + 0.729 LW) provided the most accurate estimate (R 2 = 0.99, MSE = 50.05, PRESS = 12.51) of clary sage leaf area. Validation of the regression model using the data from another experiment showed that the correlation between measured and predicted values was very high (R 2 = 0.98) with low MSE (107.74) and PRESS (26.96). and R. Kumar, S. Sharma.
The accurate and nondestructive determination of individual leaf area (LA) of plants, by using leaf length (L) and width (W) measurement or combinations of them, is important for many experimental comparisons. Here, we propose reliable and simple regressions for estimating LA across different leaf-age groups of eight common evergreen broadleaved trees in a subtropical forest in Gutianshan Natural Reserve, eastern China. During July 2007, the L, W, and LA of 2,923 leaves (202 to 476 leaves for each species) were measured for model construction and the respective measurements on 1,299 leaves were used for model validation. Mean L, W, LA and leaf shape (L:W ratio) differed significantly between current and older leaves in four out of the eight species. The coefficients of one-dimension LA models were affected by leaf age for most species while those incorporating both leaf dimensions (L and W) were independent of leaf age for all the species. Therefore, the regressions encompassing both L and W (LA = a L W + b), which were independent of leaf age and also allowed reliable LA estimations, were developed. Comparison between observed and predicted LA using these equations in another dataset, conducted for model validation, exhibited a high degree of correlation (R 2 = 0.96-0.99). Accordingly, these models can accurately estimate the LA of different age groups for the eight evergreen tree species without using instruments. and L. Zhang, L. Pan.
The aim of this study was to test the hypothesis that allopurinol ingestion modifies the slow component of • VO2 kinetics and changes plasma oxidative stress markers during severe intensity exercise. Six recreationally active male subjects were randomly assigned to receive a single dose of allopurinol (300 mg) or a placebo in a double-blind, placebo-controlled crossover design, with at least 7 days washout period between the two conditions. Two hours following allopurinol or placebo intake, subjects completed a 6-min bout of cycle exercise with the power output corresponding to 75 % • VO2 max. Blood samples were taken prior to commencing the exercise and then 5 minutes upon completion. Allopurinol intake caused increase in resting xanthine and hypoxanthine plasma concentrations, however it did not affect the slow component of oxygen uptake during exercise. Exercise elevated plasma inosine, hypoxanthine, and xanthine. Moreover, exercise induced a decrease in total antioxidant status, and sulfhydryl groups. However, no interaction treatment x time has been observed. Short term severe intensity exercise induces oxidative stress, but xanthine oxidase inhibition does not modify either the kinetics of oxygen consumption or reactive oxygen species overproduction., R. A. Olek ... [et al.]., and Obsahuje seznam literatury