TY  - JOUR
AU  - Krtolica-Žikić, Koviljka
AU  - Krajnović, Milena M.
AU  - Usaj-Knežević, Slavica
AU  - Babić, Dragan
AU  - Jovanovic, Dusan
AU  - Dimitrijević, Bogomir B.
PY  - 2007
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3184
AB  - AIM: To investigate the significance of p16 and O-6- methylguanine-DNA methyltransferase (MGMT) genes promoter hypermethylation and K-ras mutations on colorectal tumorigenesis and progression. METHODS: p16 and MGMT methylation status was examined on 47 tumor samples, and K-ras mutational status was examined on 85 tumor samples. For methylation analysis, a methylation specific PCR (MS-PCR) method was used. RESULTS: p16 and MGMT promoter methylation was found in 51% (24/47) and 43% (20/47) of CRCS, respectively, and the K-ras mutation was found in 44% (37/85) of CRCs. Comethylation of p16 and MGMT genes was significantly associated with lower aggressiveness of the disease within a two-year period of observation. Only 27% of patients with simultaneous p16 and MGMT methylation showed the detectible occurrence of metastasis and/or death, compared to 67% of patients without double methylation or with no methylation (3/11 vs 22/33, P LT 0.05, chi(2)-test). In addition, p16 and MGMT comethylation showed a trend toward an association with longer survival in patients with CRCs (35.5 +/- 6.0 mo vs 23.1 +/- 3.2 mo, P = 0.072, Log-rank test). Progression of the disease within a two-year period was observed in 66% of patients carrying the K-ras mutation, compared to only 19% of patients with wild type K-ras (29/44 vs 7/37, P LT 0.001, chi(2)-test). The presence of the K-ras mutation significantly correlated to shortened overall survival (20.0 +/- 1.9 mo vs 37.0 +/- 1.8 mo, P LT 0.001, Log-rank test). The comethylation of p16 and MGMT genes was significantly associated with lower aggressiveness of the disease even when K-ras mutations were included in the analysis as an independent variable. CONCLUSION: Our data suggest that comethylation of promoters of p16 and MGMT genes could have a prognostic value in patients with CRC. Specifically, concurrent methylation of both genes correlates with better prognosis. (C) 2007 The WJG Press. All rights reserved.
T2  - World Journal of Gastroenterology
T1  - Comethylation of p16 and MGMT genes in colorectal carcinoma: Correlation with clinicopathological features and prognostic value
VL  - 13
IS  - 8
SP  - 1187
EP  - 1194
DO  - 10.3748/wjg.v13.i8.1187
ER  - 

@article{
author = "Krtolica-Žikić, Koviljka and Krajnović, Milena M. and Usaj-Knežević, Slavica and Babić, Dragan and Jovanovic, Dusan and Dimitrijević, Bogomir B.",
year = "2007",
abstract = "AIM: To investigate the significance of p16 and O-6- methylguanine-DNA methyltransferase (MGMT) genes promoter hypermethylation and K-ras mutations on colorectal tumorigenesis and progression. METHODS: p16 and MGMT methylation status was examined on 47 tumor samples, and K-ras mutational status was examined on 85 tumor samples. For methylation analysis, a methylation specific PCR (MS-PCR) method was used. RESULTS: p16 and MGMT promoter methylation was found in 51% (24/47) and 43% (20/47) of CRCS, respectively, and the K-ras mutation was found in 44% (37/85) of CRCs. Comethylation of p16 and MGMT genes was significantly associated with lower aggressiveness of the disease within a two-year period of observation. Only 27% of patients with simultaneous p16 and MGMT methylation showed the detectible occurrence of metastasis and/or death, compared to 67% of patients without double methylation or with no methylation (3/11 vs 22/33, P LT 0.05, chi(2)-test). In addition, p16 and MGMT comethylation showed a trend toward an association with longer survival in patients with CRCs (35.5 +/- 6.0 mo vs 23.1 +/- 3.2 mo, P = 0.072, Log-rank test). Progression of the disease within a two-year period was observed in 66% of patients carrying the K-ras mutation, compared to only 19% of patients with wild type K-ras (29/44 vs 7/37, P LT 0.001, chi(2)-test). The presence of the K-ras mutation significantly correlated to shortened overall survival (20.0 +/- 1.9 mo vs 37.0 +/- 1.8 mo, P LT 0.001, Log-rank test). The comethylation of p16 and MGMT genes was significantly associated with lower aggressiveness of the disease even when K-ras mutations were included in the analysis as an independent variable. CONCLUSION: Our data suggest that comethylation of promoters of p16 and MGMT genes could have a prognostic value in patients with CRC. Specifically, concurrent methylation of both genes correlates with better prognosis. (C) 2007 The WJG Press. All rights reserved.",
journal = "World Journal of Gastroenterology",
title = "Comethylation of p16 and MGMT genes in colorectal carcinoma: Correlation with clinicopathological features and prognostic value",
volume = "13",
number = "8",
pages = "1187-1194",
doi = "10.3748/wjg.v13.i8.1187"
}

Krtolica-Žikić, K., Krajnović, M. M., Usaj-Knežević, S., Babić, D., Jovanovic, D.,& Dimitrijević, B. B.. (2007). Comethylation of p16 and MGMT genes in colorectal carcinoma: Correlation with clinicopathological features and prognostic value. in World Journal of Gastroenterology, 13(8), 1187-1194.
https://doi.org/10.3748/wjg.v13.i8.1187

Krtolica-Žikić K, Krajnović MM, Usaj-Knežević S, Babić D, Jovanovic D, Dimitrijević BB. Comethylation of p16 and MGMT genes in colorectal carcinoma: Correlation with clinicopathological features and prognostic value. in World Journal of Gastroenterology. 2007;13(8):1187-1194.
doi:10.3748/wjg.v13.i8.1187 .

Krtolica-Žikić, Koviljka, Krajnović, Milena M., Usaj-Knežević, Slavica, Babić, Dragan, Jovanovic, Dusan, Dimitrijević, Bogomir B., "Comethylation of p16 and MGMT genes in colorectal carcinoma: Correlation with clinicopathological features and prognostic value" in World Journal of Gastroenterology, 13, no. 8 (2007):1187-1194,
https://doi.org/10.3748/wjg.v13.i8.1187 . .

TY  - JOUR
AU  - Lazarevic, Slavica
AU  - Jankovic-Častvan, Ivona
AU  - Jovanovic, Dusan
AU  - Milonjić, Slobodan K.
AU  - Janaćković, Đorđe T.
AU  - Petrović, Rada
PY  - 2007
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3206
AB  - The adsorption mechanisms of Ph2+, Cd2+ and Sr2+ ions on natural sepiolite and the influence of acid treatment on the adsorption capacity of sepiolite were investigated. The point of zero charge pH(pzc), is 7.4 +/- 0.1 for natural sepiolite and 6.9 +/- 0.1 for partially acid-activated sepiolite. The shift of the pH(pzc) of sepiolites toward lower pH values in solutions of Ph2+ and Cd2+ ions indicates that specific adsorption of these cations on natural and acid-activated sepiolites occurred, which was more pronounced for Pb2+ ions than for Cd2+ ions. There was no shift of the pH(pzc) in Solution containing Sr2+ ions, suggesting that specific adsorption of this cation did not occur. The affinity for ion exchange with the Mg2+ ions from the sepiolite structure was the highest for Pb2+ ions, then Cd2+, whereas the affinity for Sr2+ ions was negligible. The adsorption isotherms suggest that the sequence of the efficiency of the sepiolites adsorption is Ph2+ GT Cd2+ GT Sr2+. The retention of Pb2+ and Cd2+ ions by sepiolite occurs dominantly by specific adsorption and exchange of Mg2+ ions from the sepiolite structure. The concentration in the external outer sphere of the Stem layer by electrostatic forces is the dominant mechanism for the retention of Sr2+ ions on the surface of sepiolites. Despite increases in the surface areas upon acid activation, improvements in the adsorption were not observed, as a result of the decreasing number of Mg-OH groups, as main centers for specific adsorption, and the number of Mg2+ ions available for ion exchange with Pb2+, Cd2+ and Sr2+ ions. The removal of Mg-OH groups from the sepiolite also resulted in a decrease in the point of zero charge and an increase of the relative surface acidity, from 2.6 +/- 0.1 for the natural to 6.4 +/- 0.1 for the acid-activated sepiolite. (C) 2006 Elsevier B.V. All rights reserved.
T2  - Applied Clay Science
T1  - Adsorption of Pb2+, Cd2+ and Sr2+ ions onto natural and acid-activated sepiolites
VL  - 37
IS  - 1-2
SP  - 47
EP  - 57
DO  - 10.1016/j.clay.2006.11.008
ER  - 

@article{
author = "Lazarevic, Slavica and Jankovic-Častvan, Ivona and Jovanovic, Dusan and Milonjić, Slobodan K. and Janaćković, Đorđe T. and Petrović, Rada",
year = "2007",
abstract = "The adsorption mechanisms of Ph2+, Cd2+ and Sr2+ ions on natural sepiolite and the influence of acid treatment on the adsorption capacity of sepiolite were investigated. The point of zero charge pH(pzc), is 7.4 +/- 0.1 for natural sepiolite and 6.9 +/- 0.1 for partially acid-activated sepiolite. The shift of the pH(pzc) of sepiolites toward lower pH values in solutions of Ph2+ and Cd2+ ions indicates that specific adsorption of these cations on natural and acid-activated sepiolites occurred, which was more pronounced for Pb2+ ions than for Cd2+ ions. There was no shift of the pH(pzc) in Solution containing Sr2+ ions, suggesting that specific adsorption of this cation did not occur. The affinity for ion exchange with the Mg2+ ions from the sepiolite structure was the highest for Pb2+ ions, then Cd2+, whereas the affinity for Sr2+ ions was negligible. The adsorption isotherms suggest that the sequence of the efficiency of the sepiolites adsorption is Ph2+ GT Cd2+ GT Sr2+. The retention of Pb2+ and Cd2+ ions by sepiolite occurs dominantly by specific adsorption and exchange of Mg2+ ions from the sepiolite structure. The concentration in the external outer sphere of the Stem layer by electrostatic forces is the dominant mechanism for the retention of Sr2+ ions on the surface of sepiolites. Despite increases in the surface areas upon acid activation, improvements in the adsorption were not observed, as a result of the decreasing number of Mg-OH groups, as main centers for specific adsorption, and the number of Mg2+ ions available for ion exchange with Pb2+, Cd2+ and Sr2+ ions. The removal of Mg-OH groups from the sepiolite also resulted in a decrease in the point of zero charge and an increase of the relative surface acidity, from 2.6 +/- 0.1 for the natural to 6.4 +/- 0.1 for the acid-activated sepiolite. (C) 2006 Elsevier B.V. All rights reserved.",
journal = "Applied Clay Science",
title = "Adsorption of Pb2+, Cd2+ and Sr2+ ions onto natural and acid-activated sepiolites",
volume = "37",
number = "1-2",
pages = "47-57",
doi = "10.1016/j.clay.2006.11.008"
}

Lazarevic, S., Jankovic-Častvan, I., Jovanovic, D., Milonjić, S. K., Janaćković, Đ. T.,& Petrović, R.. (2007). Adsorption of Pb2+, Cd2+ and Sr2+ ions onto natural and acid-activated sepiolites. in Applied Clay Science, 37(1-2), 47-57.
https://doi.org/10.1016/j.clay.2006.11.008

Lazarevic S, Jankovic-Častvan I, Jovanovic D, Milonjić SK, Janaćković ĐT, Petrović R. Adsorption of Pb2+, Cd2+ and Sr2+ ions onto natural and acid-activated sepiolites. in Applied Clay Science. 2007;37(1-2):47-57.
doi:10.1016/j.clay.2006.11.008 .

Lazarevic, Slavica, Jankovic-Častvan, Ivona, Jovanovic, Dusan, Milonjić, Slobodan K., Janaćković, Đorđe T., Petrović, Rada, "Adsorption of Pb2+, Cd2+ and Sr2+ ions onto natural and acid-activated sepiolites" in Applied Clay Science, 37, no. 1-2 (2007):47-57,
https://doi.org/10.1016/j.clay.2006.11.008 . .