Selected miRNA levels are associated with IKZF1 microdeletions in pediatric acute lymphoblastic leukemia.

The clinical outcome of children with high-risk relapsed B-cell precursor acute lymphoblastic leukemia (BCP-ALL) is poor. The present study assessed the utility and prognostic value of selected microRNA (miRNA/miR) in BCP-ALL. The changes in the expression levels of these miRNAs regarding known gene lesions affecting lymphoid development [early B-cell factor 1 (EBF1), ETS variant 6 (ETV6), IKAROS family zinc finger 1 (IKZF1), paired box 5 (PAX5), cyclin dependent kinase inhibitor (CDKN) 2A/CDKN2B, retinoblastoma 1 (RB1), pseudoautosomal region 1 (PAR1), B-cell translocation gene 1 protein (BTG1)] were analyzed. The following miRNAs were analyzed: miR-24, miR-31, miR-128, miR-542, and miR-708. The present study focused on patients with deletions of the IKAROS transcriptional factor gene IKZF1, which is currently considered to be an independent negative prognostic factor for ALL outcome. It was demonstrated that the expression level of miR-128 was significantly lower in patients with IKZF1 deletion compared with patients without IKZF1 deletion. Additionally, low expression of miR-542 was associated with CDKN2A/B and miR-31deletions, and low expression of miR-24 was associated with miR-31 deletion. Low expression of miR-31, miR-24, miR-708 and miR-128 was associated with PAX5 deletion, high expression of miR-24 and miR-542 was associated with PAR1 deletion and high expression of miR-708 was associated with ETV6 deletion. The expression of the selected miRNAs was not associated with deletions of BTG1, EBF1 and RB1. These data, by emphasizing the association of miRNAs expression level with microdeletions, may assist to elucidate ALL biology and contribute to future studies on the possible applications of the miRNA profile for diagnosis.

Modeling the effect of temperature on survival rate of Listeria monocytogenes in yogurt.

The aim of the study was to (i) evaluate the behavior of Listeria monocytogenes in a commercially produced yogurt, (ii) determine the survival/inactivation rates of L. monocytogenes during cold storage of yogurt and (iii) to generate primary and secondary mathematical models to predict the behavior of these bacteria during storage at different temperatures. The samples of yogurt were inoculated with the mixture of three L. monocytogenes strains and stored at 3, 6, 9, 12 and 15°C for 16 days. The number of listeriae was determined after 0, 1, 2, 3, 5, 7, 9, 12, 14 and 16 days of storage. From each sample a series of decimal dilutions were prepared and plated onto ALOA agar (agar for Listeria according to Ottaviani and Agosti). It was found that applied temperature and storage time significantly influenced the survival rate of listeriae (p<0.01). The number of L. monocytogenes in all the samples decreased linearly with storage time. The slowest decrease in the number of the bacteria was found in the samples stored at 6°C (D-10 value = 243.9 h), whereas the highest reduction in the number of the bacteria was observed in the samples stored at 15°C (D-10 value = 87.0 h). The number of L. monocytogenes was correlated with the pH value of the samples (p<0.01). The natural logarithm of the mean survival/inactivation rates of L. monocytogenes calculated from the primary model was fitted to two secondary models, namely linear and polynomial. Mathematical equations obtained from both secondary models can be applied as a tool for the prediction of the survival/inactivation rate of L. monocytogenes in yogurt stored under temperature range from 3 to 15°C, however, the polynomial model gave a better fit to the experimental data.

Effects of high hydrostatic pressure on Campylobacter jejuni in poultry meat.

Campylobacter jejuni inactivation by high pressure processing (HPP) in poultry meat (chicken breast) was investigated. The pressure was created by high hydrostatic pressure piston-cylinder food processor. Contaminated with C. jejuni (108 CFU g-1) samples of ground poultry meat were hermetically sealed in a polyamide-polyethylene bags and exposed to HPP for 9 different combinations of pressure (200 MPa, 300 MPa and 400 MPa) and time (5 min, 10 min and 15 min). Quantitative bacteriological analysis was carried out in order to determine the number of surviving C. jejuni cells. The obtained results showed that C. jejuni is relatively sensitive to high pressure treatment as compared to other food-borne pathogens. The loss of C. jejuni viability increased in a dose- and time-dependent manner. On the basis of the results, D-values were calculated. For reduction C. jejuni in poultry meat by 6 log units (6D-values), considered as sufficient for consumer protection, the application of 300 MPa for 8.73 min, or 400 MPa for 4.37 min is needed. The linear regression equations, which has been calculated on the basis of this study, allows to determine the degree of C. jejuni reduction in poultry meat for any selected duration of pressurization in a given pressure range.

Modeling the effect of temperature on survival rate of Salmonella Enteritidis in yogurt.

The aim of the study was to determine the inactivation rates of Salmonella Enteritidis in commercially produced yogurt and to generate primary and secondary mathematical models to predict the behaviour of these bacteria during storage at different temperatures. The samples were inoculated with the mixture of three S. Enteritidis strains and stored at 5 degrees C, 10 degrees C, 15 degrees C, 20 degrees C and 25 degrees C for 24 h. The number of salmonellae was determined every two hours. It was found that the number of bacteria decreased linearly with storage time in all samples. Storage temperature and pH of yogurt significantly influenced survival rate of S. Enteritidis (p < 0.05). In samples kept at 5 degrees C the number of salmonellae decreased at the lowest rate, whereas at 25 degrees C the reduction in number of bacteria was the most dynamic. The natural logarithm of mean inactivation rates of Salmonella calculated from primary model was fitted to two secondary models: linear and polynomial. Equations obtained from both secondary models can be applied as a tool for prediction of inactivation rate of Salmonella in yogurt stored under temperature range from 5 to 25 degrees C; however, polynomial model gave the better fit to the experimental data.

Genetic variability of GCKR alters lipid profiles in children with monogenic and autoimmune diabetes.

PURPOSE: Mutations in the glucokinase (GCK) gene are associated with altered blood glucose and lipid concentrations. Our aim was to assess the effects on HbA1c and serum lipid levels of single nucleotide polymorphisms (SNPs) in 2 genes encoding proteins that interact with glucokinase: glucose-6-phospatase catalytic subunit 2 (G6PC2) and glucokinase regulatory protein (GCKR). METHODS: The study group included 129 children with GCK-MODY from the Polish Registry of Monogenic Diabetes and 395 with type 1 diabetes (T1DM), in whom we genotyped 2 SNPs in G6PC2 (rs560887) and GCKR (rs1260326). Lipid concentrations were assessed in fasting serum samples. RESULTS: Total and HDL cholesterol concentrations were significantly lower in the GCK-MODY group than in patients with T1DM (167.5±32.5 mg/dl vs. 174.4±31.1 mg/dl, p=0.0435 and 48.42±14.3 mg/dl vs. 58.7±12.7 mg/dl, p<0.0001, respectively). No differences in genotype distributions were found except for underrepresentation of GCKR TT homozygotes among GCK-MODY patients (10.9% in GCK-MODY vs. 17.7% in T1DM, p=0.0651). GCKR genotypes showed significant associations with lipid profiles and HbA1c levels, whereas no such associations were noted for G6PC2. After adjustment for confounders, TT homozygotes were shown to have higher total cholesterol and marginally higher LDL cholesterol and triglyceride levels (p=0.0245, p=0.0657 and p=0.0550, respectively). The difference between TT homozygotes and other genotypes was similar in magnitude within the GCK-MODY and T1DM groups. No significant interactions between the type of diabetes and the GCKR or G6PC2 genotype were detected. CONCLUSIONS: Individuals who are homozygous TT at rs1260326 of the GCKR gene have higher triglyceride, total and LDL cholesterol levels regardless of the presence of GCK mutations.

Survival of Staphylococcus aureus exposed to UV radiation on the surface of ceramic tiles coated with TiO2.

The aim of this study was to determine and compare the antimicrobial activity of UV radiation of wavelength 253.7 nm (used in typical germicidal lamps) against Staphylococcus aureus on the surfaces of conventionally produced white ceramic wall tiles (matt and shiny) and the same tiles coated with TiO2 using three different methods: RF diode sputtering, atmospheric pressure chemical vapour deposition (APCVD) and spray pyrolysis deposition (SPD). Results clearly indicate that the bactericidal action of UV radiation is much stronger on the surfaces of tiles coated with TiO2 than on the tiles uncovered. The strongest bactericidal effect of UV radiation was found for film prepared by APCVD. Results of experiments for shiny and matt tiles did not differ statistically. The use of ceramic wall tiles coated with TiO2 films in hospitals, veterinary clinics, laboratories, food processing plants and other places where UV radiation is applied for disinfection should greatly improve the efficiency of this treatment.