Interaction mechanism of benzophenone-type UV filters on bovine serum albumin: Insights from structure-affinity relationship.

Benzophenone (BP)-type UV filters can cause structural changes of carrier protein in plasma. The binding process of five BP-type UV filters with bovine serum albumin (BSA) was investigated by multiple characterization methods, along with their structure-affinity relationship involving the structure of the five BP-type UV filters and their binding affinity for BSA. The BP-type UV filters investigated bound to BSA spontaneously, and altered conformation of BSA. The binding constants and number of binding sites between BP-type UV filters and BSA were 103-106 M-1 and 0.82-1.26, respectively. These BP-type UV filters and BSA interacted with the same binding forces and went through the similar binding process, suggesting that the benzophenone skeleton structure was primarily responsible for the BP-type UV filters and BSA binding, and changes in the structure of the BSA. The BP-type UV filters with hydroxyl substituent (BP-1 and BP-9) and non-polar molecules (BP-6) had a high affinity for binding BSA and had a greater impact on BSA conformation.

A pooled analysis of risk factors of surgically treated leiomyosarcoma of the colon in adults.

BACKGROUND: This current systematic review aimed to evaluate the role of surgical management and risk factors by pooled cases from all identified patients with colonic leiomyosarcomas. METHODS: The authors searched the Ovid MEDLINE, Embase, PubMed, and Cochrane databases using the keywords "colonic," "colon," and "leiomyosarcoma." Risk factors of colonic leiomyosarcoma in the pooled cohort were also evaluated. RESULTS: Between 1923 and 2019, 41 cases of colonic leiomyosarcoma were identified in 22 (53.7%) males and 19 (46.3%) females, with a mean and median age of 58.7 ± 2.2 years and 56.0 years. According to univariate analysis, smaller tumor size < 8 cm was significantly associated with longer progression-free survival (HR = 6.957, 95% CI 1.405-34.442; p = 0.017), and younger age < 60 years was trending toward better overall survival (HR = 2.765, 95% CI 0.924-8.272; p = 0.069). CONCLUSIONS: Colonic leiomyosarcomas are rare neoplasms with aggressive clinical behaviors. Age < 60 years and tumor size < 8 cm were favorable factors for patients' better survival.

ABCA8: A potential therapeutic target in the treatment of colorectal cancer?

None.

Photolysis of polycyclic aromatic hydrocarbons on soil surfaces under UV irradiation.

Photolysis of some polycyclic aromatic hydrocarbons (PAHs) on soil surfaces may play an important role in the fate of PAHs in the environment. Photolysis of PAHs on soil surfaces under UV irradiation was investigated. The effects of oxygen, irradiation intensity and soil moisture on the degradation of the three PAHs were observed. The results showed that oxygen, soil moisture and irradiation intensity enhanced the photolysis of the three PAHs on soil surfaces. The degradation of the three PAHs on soil surfaces is related to their absorption spectra and the oxidation-half-wave potential. The photolysis of PAHs on soil surfaces in the presence of oxygen followed pseudo first-order kinetics. The photolysis half-lives ranged from 37.87 days for benzo[a]pyrene to 58.73 days for phenanthrene. The results indicate that photolysis is a successful way to remediate PAHs-contaminated soils.

Photocatalytic degradation of phenanthrene on soil surfaces in the presence of nanometer anatase TiO2 under UV-light.

The effect of nanometer anatase TiO2 was investigated on the photocatalytic degradation of phenanthrene on soil surfaces under a variety of conditions. After being spiked with phenanthrene, soil samples loaded with different amounts of TiO2 (0 wt.%, 1 wt.%, 2 wt.%, 3 wt.%, and 4 wt.%) were exposed to UV-light irradiation for 25 hr. The results indicated that the photocatalytic degradation of phenanthrene followed the pseudo first-order kinetics. TiO2 significantly accelerated the degradation of phenanthrene with the half-life reduced from 45.90 to 31.36 hr for TiO2 loading of 0 wt.% and 4 wt.%, respectively. In addition, the effects of H2O2, light intensity and humic acid on the degradation of phenanthrene were investigated. The degradation of phenanthrene increased with the concentration of H2O2, light intensity and the concentration of humic acids. It has been demonstrated that the photocatalytic method in the presence of nanometer anatase TiO2 was a very promising technology for the treatments of soil polluted with organic substances in the future.

A mutispectroscopic study on the structure-affinity relationship of the interactions of bisphenol analogues with bovine serum albumin.

Bisphenol A (BPA) is a recognized endocrine-disrupting chemical (EDC), and its analogues also exert negative effects on health. The structure-affinity relationship between the structures of nine bisphenol (BP) analogues and the conformational changes of bovine serum albumin (BSA) was studied by various characterization methods and molecular docking. BPs including BPA and its analogues, bisphenol B (BPB), bisphenol C (BPC), bisphenol AP (BPAP), bisphenol M (BPM), bisphenol P (BPP), bisphenol Z (BPZ), diethylstilbestrol (DES) and dienestrol (DS) interacted with BSA. At the concentration of 3.85 × 10-5 mol l-1, DS was found to lead to 64% quenching, while BPAP, BPM and DES quenched 60%, 59% and 55% of BSA fluorescence, respectively. The values of ΔH (-19.31-135.42 kJ mol-1) and ΔS (12.52-495.63 J mol-1 K-1) indicated that hydrophobic interactions and hydrogen bonds played important roles in the binding process. The binding constants of DS (8.87 × 104 l mol-1), DES (3.05 × 104 l mol-1), BPAP (1.52 × 104 l mol-1), BPC (1.16 × 104 l mol-1) and BPM (1.10 × 104 l mol-1) to BSA were greater than that of BPA (1.18 × 103 l mol-1) to BSA, indicating that they may exert more negative effects than BPA. The molecular structure differences of these BPs partly affected their ability to bind to BSA. The binding constants of BPB/BPP to BSA were smaller due to the steric hindrance of ethyl and benzene ring. BPs with conjugated double bond structures (DS and DES) and benzene ring structures (BPM, BPP, BPAP) had a greater influence on the conformation of BSA.

Long non-coding RNA TUG1-mediated down-regulation of KLF4 contributes to metastasis and the epithelial-to-mesenchymal transition of colorectal cancer by miR-153-1.

INTRODUCTION: Taurine up-regulated 1 (TUG1) was reported to be over-expressed and involved in various human malignancies. However, its expression status and mechanistic importance in colorectal cancer (CRC) were yet to be defined. METHODS: Relative expressions of TUG1, miR-153-1 and Kruppel-like factor 4 (KLF4) were analyzed by real-time PCR. The potential influences of TUG1-proficiency and miR-153-1-deficiency on cell proliferation, migration and viability were determined by colony formation, wound healing and CCK-8 assays, respectively. Cell invasion was evaluated by transwell chamber assay. The regulatory effect of KLF4 on miR-153-1 was interrogated by luciferase reporter assay. Direct association between KLF4 and miR-153-1 promoter was measured by chromatin immunoprecipitation (ChIP) assay. Subcellular localization of TUG1 was determined by fractionization PCR. Enrichment of EZH2 on KLF4 promoter was analyzed by ChIP-PCR. The pro-tumoral activity of TUG1 was determined using xenograft tumor model. RESULTS: We demonstrated the over-expression of TUG1 and down-regulation of miR-153-1 in CRC. Knockdown of TUG1 or ectopic over-expression of miR-153-1 in SW480 significantly suppressed cell proliferation, migration and viability. TUG1 negatively modulated miR-153-1 expression, and simultaneous expression of TUG1 completely abolished the anti-tumor effect of miR-153-1. We further identified KLF4 as a transcription factor of miR-153-1, which was negatively regulated by TUG1 along with EZH2. CONCLUSION: Our study unravels the critical involvement of TUG1/KLF4/miR-153-1 axis in CRC.

[Interaction of tributyltin (TBT) compound and bovine serum albumin (BSA)].

Tributyltin (TBT) compound is one of the main components of antifouling paint for boats and ships. The interaction of TBT compound and bovine serum albumin (BSA) was investigated by ultraviolet, fluorescence and circular dichroism (CD) spectra. The influences of concentration, acidity and organic solvent were also studied. The results showed that the interaction of TBT and BSA was dual, showing not only the hydrophobic actions of butyl groups but also the coordination action of tin cation with BSA molecule, which resulted in the exposures of aromatic amino acids residues of tryptophane and tyrosine in BSA molecule, the destruction of BSA secondary structure, the decrease in alpha-helix content, and the transformation of the conformation.

Investigation on the sonocatalytic degradation of parathion in the presence of nanometer rutile titanium dioxide (TiO2) catalyst.

The nanometer rutile titanium dioxide (TiO2) powder was adopted to act as the sonocatalyst after treatment of high-temperature activation and the ultrasound of low power was used as an irradiation source to induce heat-treated TiO2 powder performing sonocatalytic degradation of parathion. Although there are many factors influencing sonocatalytic degradation of parathion, the experimental results demonstrate that the optimal degradation condition of parathion can be obtained when the experimental conditions such as initial concentration of 50 mg/L parathion, addition amount of 1000 mg/L nanometer rutile TiO2, ultrasonic of 30-50 kHz frequency and 50 W output power, acidity of pH 10.0 and temperature of 20 degrees C are adopted. The degradation ratio of parathion surpassed 90% within 120 min ultrasonic irradiation in these optimal experiment conditions. The total degradation process of parathion has been monitored by UV-vis spectra and ion chromatography. At last, the parathions in aqueous solution are completely degraded and become some simple inorganic ions such as NO3(-), PO4(3-), SO4(2-), etc. In addition, the sonocatalytic activities of reused TiO2 catalysts were also studied and found to decline gradually along with the reused times. In this paper, the research on sonocatalytic degradation kinetics was also been performed and found to follow pseudo first-order reaction. All experiments indicated that the sonocatalytic method in the presence of nanometer rutile TiO2 powder was an advisable choice for the treatments of non- or low-transparent organic wastewaters in future.

Studies on the interaction between triphenyltin and bovine serum albumin by fluorescence and CD spectroscopy.

The interaction between triphenyltin (TPT) and bovine serum albumin (BSA) in physiological buffer (pH=7.4) was investigated by the fluorescence quenching technique. The results of fluorescence titration revealed that TPT could strongly quench the intrinsic fluorescence of BSA through a static quenching procedure. The apparent binding constants K and number of binding sites n of TPT with BSA were (7.04±0.0057)×10(2) and (0.77±0.016) which were obtained by the fluorescence quenching method. The thermodynamic parameters enthalpy change (ΔH), entropy change (ΔS) were positive, which indicated that the interaction of TPT with BSA was driven mainly by hydrophobic forces. The process of binding was a spontaneous process in which Gibbs free energy change was negative. The distance r between donor (BSA) and acceptor (TPT) was calculated to be 3.05nm based on Forster's non-radiative energy transfer theory. The results of synchronous fluorescence, three-dimensional fluorescence and Circular Dichroism (CD) spectra showed that the triphenyltin induced conformational changes of BSA.

Ageing behavior of phenanthrene and pyrene in soils: a study using sodium dodecylbenzenesulfonate extraction.

The surfactant SDBS has potential to be used as an extractant in advanced extraction methods. It was investigated if SDBS in concentrations of 10,000 mg L(-1) can be used to study the ageing behaviors of phenanthrene and pyrene in two soils. Compared to dichloromethane extraction, extraction with 10,000 mg L(-1) SDBS can improve the precision of the determination due to the low volatility of surfactant solution. In all cases tested, the amount of sorbed phenanthrene and pyrene in soils increased with contact time from 1 to 120 days, and can be applied well to both the three-domain model and the dual mode model. Redundancy analysis showed that time, organic carbon content and logK(ow) are major factors affecting the fitted Freundlich parameters and the sorption kinetics of phenanthrene and pyrene. The amount of sorbed phenanthrene and pyrene in low-concentrations samples varied more with time than the one in high concentrations, indicating that the sorption on soils is concentration-dependent. Also, the isotherms were operationally separated into a "fast" fraction and a "slow" fraction. The results imply that the adsorption sites are internal to the SOM matrix and unevenly distributed.

Investigation on the photocatalytic degradation of pyrene on soil surfaces using nanometer anatase TiO2 under UV irradiation.

Photocatalytic degradation of pyrene on soil surfaces was investigated in the presence of nanometer anatase TiO(2) under a variety of conditions. After being spiked with pyrene, soil samples loaded with different amounts of TiO(2) (0%, 1%, 2%, 3%, and 4%, w/w) were exposed to UV irradiation for 25h. The results indicated that the photocatalytic degradation of pyrene followed pseudo-first-order kinetics. TiO(2) accelerated the degradation of pyrene generally as indicated by the half-life reduction from 45.90 to 31.36h, corresponding to the TiO(2) amounts from 0% to 4%, respectively. The effects of H(2)O(2), light intensity and humic acids on the degradation of pyrene were also investigated. The degradation of pyrene increased along with increasing the concentration of H(2)O(2), light intensity and the concentration of humic acids. All results indicated that the photocatalytic method in the presence of nanometer anatase TiO(2) was an advisable choice for the treatments of PAHs polluted soil in the future.

Effects of aging and freeze-thawing on extractability of pyrene in soil.

The effects of soil freezing and thawing on the extractability by dichloromethane of pyrene from two Chinese soils are investigated. The soils were collected from the Northeast region of China where heavy pollution of soils by Polycyclic Aromatic Hydrocarbons (PAH) is common. Two soils were considered: a burozem obtained from the Shenfu irrigated region in Liaoning province and a phaeozem collected from the Hailun area in Haerbin province. The soils were collected from areas free from PAH pollution. Pyrene was aged in sterilized soil, and autoclaved deionized water was then added to adjust the soil to different moisture levels. The combined dichloromethane extractions of pyrene in soils at various periods showed that the quantity of pyrene extracted with dichloromethane could be divided into two stages: the initially rapid period and a longer, slower period. The frequency of freeze-thawing cycles had different and contradictory effects on pyrene extractability between the two soil types. Soil moisture also was found to have different and opposite effects on pyrene extractability. Freeze-thawing cycles had great influence on pyrene extractability both in aged and unaged soils. The changes in unaged soil were more significant than those in 1-year aged soil and attributed to changes in the soil organic matter. Our research shows that the effect of freezing and thawing on pyrene extraction is complicated due to the differences in physical and chemical properties of soils as well as the aging process.

[Microbial degradation of soil polycyclic aromatic hydrocarbons (PAHs) and its relations to soil bacterial population diversity].

A laboratory simulation test was conducted to study the microbial remediation of soils contaminated by medium and low concentration polycyclic aromatic hydrocarbons (PAHs), and the relationships between the degradation of PAHs and the inoculated and indigenous microbes. The addition of high-effective PAHs-degrading bacteria promoted the biodegradation of soil PAHs, and the effect was remarkable in the first two weeks. The biodegradation of test PAHs was phenanthrene < anthracene < pyrene < benzo [a] pyrene < chrysene, and negatively correlated with the diversity/abundance of soil bacterial population. In the same treatments, soil bacterial population structure varied less with time, and hence, to increase the activity of indigenous microbes would be an effective way to remediate the farmland soils contaminated by medium and low concentration PAHs.