Multifractal characterization of the Coniacian-Santonian OAE3 in lacustrine and marine deposits based on spectral gamma ray logs.

Limited to the Atlantic and its surrounding basins, the expression of the Coniacian-Santonian oceanic anoxic event (OAE3) was discovered in the non-marine Cretaceous Songliao Basin, Eastern Asia not long ago. In this study, based on spectral gamma ray logs data recorded in three basins, the self-similarity of the OAE3 was studied through the analysis of the scaling properties of thorium-potassium and thorium-uranium distributions both in marine and terrestrial environments using the multifractal detrending fluctuation analysis. The results indicate that, in both marine and terrestrial systems, the OAE3 intervals are characterized by their multifractal nature due to long-range correlation. However, the multifractal features of the studied OAE3 intervals are different in the three basins, although some common trends were observed. By comparing the degree of multifractality of the OAE3 deposits with the clay minerals and the redox conditions, it appears that the changes of the multifractal features are controlled by local changes such as clay mineralogy and redox conditions in both milieus under different sedimentation patterns. At all sites, the left side shortened spectrum of the thorium-potassium distribution suggests the presence of local fluctuations with minor amplitudes during the OAE3. Furthermore, the shortened singularity spectrum of the thorium-uranium distribution reflects the existence of small-scale fluctuations with large amplitudes at marine sites while in the non-marine Songliao Basin, the thorium-uranium distribution suggests the presence of local fluctuations with small amplitudes during the OAE3. Therefore, a more local behavior of the event is considered although the regional character is not neglected.

Gas hydrate saturations estimated from pore-and fracture-filling gas hydrate reservoirs in the Qilian Mountain permafrost, China.

Accurate calculation of gas hydrate saturation is an important aspect of gas hydrate resource evaluation. The effective medium theory (EMT model), the velocity model based on two-phase medium theory (TPT model), and the two component laminated media model (TCLM model), are adopted to investigate the characteristics of acoustic velocity and gas hydrate saturation of pore- and fracture-filling reservoirs in the Qilian Mountain permafrost, China. The compressional wave (P-wave) velocity simulated by the EMT model is more consistent with actual log data than the TPT model in the pore-filling reservoir. The range of the gas hydrate saturation of the typical pore-filling reservoir in hole DKXX-13 is 13.0~85.0%, and the average value of the gas hydrate saturation is 61.9%, which is in accordance with the results by the standard Archie equation and actual core test. The P-wave phase velocity simulated by the TCLM model can be transformed directly into the P-wave transverse velocity in a fracture-filling reservoir. The range of the gas hydrate saturation of the typical fracture-filling reservoir in hole DKXX-19 is 14.1~89.9%, and the average value of the gas hydrate saturation is 69.4%, which is in accordance with actual core test results.

Acoustic velocity log numerical simulation and saturation estimation of gas hydrate reservoir in Shenhu area, South China Sea.

Gas hydrate model and free gas model are established, and two-phase theory (TPT) for numerical simulation of elastic wave velocity is adopted to investigate the unconsolidated deep-water sedimentary strata in Shenhu area, South China Sea. The relationships between compression wave (P wave) velocity and gas hydrate saturation, free gas saturation, and sediment porosity at site SH2 are studied, respectively, and gas hydrate saturation of research area is estimated by gas hydrate model. In depth of 50 to 245 m below seafloor (mbsf), as sediment porosity decreases, P wave velocity increases gradually; as gas hydrate saturation increases, P wave velocity increases gradually; as free gas saturation increases, P wave velocity decreases. This rule is almost consistent with the previous research result. In depth of 195 to 220 mbsf, the actual measurement of P wave velocity increases significantly relative to the P wave velocity of saturated water modeling, and this layer is determined to be rich in gas hydrate. The average value of gas hydrate saturation estimated from the TPT model is 23.2%, and the maximum saturation is 31.5%, which is basically in accordance with simplified three-phase equation (STPE), effective medium theory (EMT), resistivity log (Rt), and chloride anomaly method.

Comparing the effect of ATRA, 4-HPR, and CD437 in bladder cancer cells.

Clinical trials have explored the use of natural and synthetic retinoids for the prevention of bladder cancer recurrence. Natural retinoids have been shown to inhibit bladder cancer growth. Here, we compared the effects of natural and synthetic retinoids in bladder cancer cells. Bladder cancer cell lines were treated with all-trans-retinoid acid (ATRA), N-4-hydroxyphenyl-retinamide (4-HPR) and 6-[3-(1-adamantyl)-4 hydroxyphenyl]-2-naphthalene carboxylic acid (CD437). Their effects on cell growth, apoptosis, cell cycle, gene expression, and retinoid acid receptors (RARs) and the JWA-retinoid response gene were assessed. Most of the bladder cancer cells were resistant to ATRA (1 and 10 microM). 4-HPR inhibited cell growth by 90% at 10 microM; however, CD437 showed the same effect at 1 microM. 4-HPR and CD437 increased G1 and decreased S phase. The three retinoids differentially affected p53, RARs, and JWA. Only CD437 increased Caspase 3 expression. The results demonstrated that 4-HPR and CD437 were more potent growth inhibitors and apoptosis inducers than ATRA. However, 4-HPR was effective at a concentration at least 10 microM. The in vitro results suggested the higher dose of 4-HPR in chemoprevention trial be considered.

Effect of retinoic acid and interferon alpha-2a on transitional cell carcinoma of bladder.

PURPOSE: Retinoids modulate the growth and differentiation of normal and malignant epithelial cells in vitro and in vivo. Retinoids and their analogues have been used in animal models and clinical trials of chemoprevention and superficial bladder cancer treatment. Interferons are cytokines that have antiviral, antiproliferative and immunomodulatory function. They are used in many clinical trials for the treatment of different cancers. To identify new effective agents and develop novel approaches for the chemoprevention and treatment of superficial bladder cancer we investigated the effects of a combination of retinoids and interferon alpha-2a (IFN) on growth and apoptosis in bladder cancer cell lines. MATERIALS AND METHODS: The 4 bladder cancer cell lines UM-UC-6, UM-UC-9, UM-UC-10 and UM-UC-13 were treated with 2 retinoids, namely all-trans-retinoic acid (ATRA) and 9-cis retinoic acid (9cRA), as well as with IFN or with combinations of retinoids and IFN. The ability of these agents used alone and in combination to inhibit growth, induce apoptosis and modulate gene expression was investigated. The effects of retinoids on an INF related gene were also examined. RESULTS: Most bladder cancer cell lines were resistant to growth inhibition and apoptosis induction by ATRA and 9cRA, even at a high concentration. The effects of these retinoids on cell growth and apoptosis were enhanced by IFN. The combination of ATRA and IFN induced retinoic acid receptor beta, and signal transducer and activator of transcription 1 expression in 3 bladder cancer cell lines, as detected by reverse transcriptase-polymerase chain reaction and Western blot analysis. Retinoids increased IFN-related gene expression detected by microarray analysis and real-time reverse transcriptase-polymerase chain reaction. CONCLUSIONS: The results demonstrate that IFN acts synergistically with ATRA and 9cRA in the growth and apoptosis of bladder cancer cells in vitro and suggest that this combination has a potential for the treatment of transitional cell carcinoma of the bladder.

N-(4-hydroxyphenyl)retinamide (4-HPR) modulates GADD45 expression in radiosensitive bladder cancer cell lines.

We previously demonstrated that N-(4-hydroxyphenyl)retinamide (4-HPR) and gamma-irradiation, when used in combination, had a synergistic effect in inducing apoptosis in bladder cancer cells, suggesting that 4-HPR may increase radiosensitivity in bladder cancer cells. To unravel molecular correlates in this radiosensitizing effect of 4-HPR, we examined the baseline and 4-HPR-induced expression of GADD45 to elucidate possible mechanisms by which 4-HPR enhanced the effect of gamma-irradiation in three bladder cancer cell lines. To investigate the role of p53 in mediating the radiosensitizing effect of 4-HPR, we also examined mutations in exons 5-9 by using direct sequencing and the levels of p53 expression by using RT-PCR and Western blot, before and after treatment with 4-HPR in these bladder cancer cell lines. Two cell lines had low expression of GADD45, and a dose-dependent increase in GADD45 expression induced by 4-HPR was found in bladder cancer cell lines without p53 mutations in exons 5-9. A combination of gamma-irradiation and 4-HPR showed a significantly greater effect in enhancing GADD45 expression than either agent used alone. The results indicate that the combined treatment with 4-HPR and gamma-irradiation has a stronger effect on GADD45 expression than the treatment with either agent alone, which suggests that the two agents may have an additive/synergistic effect. However, a normal p53 function appears to be necessary for the dose-dependent induction of GADD45 by 4-HPR. Once our results are verified and replicated by other investigators, 4-HPR may have a potential clinical implication in effectively treating bladder cancer in combination with low-gamma-irradiation therapy.

Growth inhibition and apoptosis induction by retinoic acid and interferon combined use on transitional cell carcinoma of bladder / 中华泌尿外科杂志

Objective To investigate the effects of combination of retinoids and interferon ?-2a on growth inhibition and apoptosis induction in bladder cancer cell lines. Methods Four bladder cancer cell lines and two retinoids,all-trans-retinoic acid (ATRA),9-cis retinoic acid (9cRA),combined with interferon ?-2a(IFN),were used in the study.The abilities of these agents to inhibit growth,induce apoptosis were compared and the expression of nuclear retinoid receptors,Stat1 protein were measured by means of TUNEL,FCM,RT-PCR and Western blot. Results Most of the bladder cancer cell lines were resistant to the effect of ATRA and 9cRA on growth inhibition and apoptosis induction.The effects of ATRA and 9cRA on cell growth and apoptosis were enhanced by IFN ?-2a.Combination of ATRA and IFN ?-2a induced RAR? and Stat 1 expression in three bladder cancer cell lines. Conclusions INF ?-2a synergizes with the inhibitory effect of ATRA and 9cRA on the growth inhibition and apoptosis of bladder cancer cells in vitro,up-regutation of Stat1 gene expression could be the main molecular mechanism.