Determination of phthalate esters in bottled beverages by direct immersion solid-phase microextraction with a porous boron nitride coated fiber followed by gas chromatography-mass spectrometry.

A porous boron nitride with a large surface area was synthesized by a one-step grinding method with melamine, urea, and boric acid as the precursors. The prepared porous boron nitride was used as the fiber coating material for the solid-phase microextraction of seven phthalate esters (diethyl phthalate, diallyl phthalate, diisobutyl phthalate, dibutyl phthalate, butylbenzyl phthalate, dicyclohexyl phthalate, and di-2-ethylhexyl phthalate) prior to their gas chromatography-mass spectrometric detection. The important experimental parameters including the extraction time, extraction temperature, salt concentration, and stirring rate were optimized by both single factor and central composite design methods. Under the optimized experimental conditions, the linear response range for the analytes was from 0.030 to 30.0 µg/L, and the limits of detection were from 0.010 to 0.040 µg/L, respectively. The relative recoveries of the analytes for spiked samples at two concentration levels were 83.0-109% with the relative standard deviations less than 12%. The established method was successfully applied for the determination of the phthalate esters in bottled juice beverage samples.

A novel porphyrin-based conjugated microporous nanomaterial for solid-phase microextraction of phthalate esters residues in children's food.

A novel porphyrin-based conjugated microporous polymer (PCMP) with microporous structure and nitrogen-rich pyrrole building blocks was synthesized. The PCMP was used as a coating material to prepare solid-phase microextraction (SPME) fibers by sol-gel technique. Due to the toxicity of the phthalate esters (PAEs) and the necessity for their sensitive determinations in some food samples, the SPME fiber was investigated for the extraction of eleven PAEs from six different children's milk beverages prior to their detection by gas chromatography-mass spectrometry. Under the optimal conditions, the linear response range for the PAEs was in the range from 0.03 to 200 µg L-1 and the limits of detection (S/N = 3) for the analytes were 0.01-3.00 µg L-1. The method recoveries for the PAEs were between 80% and 120%, with the relative standard deviations varying from 1.3% to 9.8%. The method was successfully applied for the determination of PAEs in children's milk beverages.

Efficient solid-phase microextraction of twelve halogens-containing environmental hormones from fruits and vegetables by triazine-based conjugated microporous polymer coating.

A triazine-based conjugated microporous polymer (TCMP) was generated by introduced 1, 3, 5-triazine into conjugated microporous polymer network via Friedel-Crafts reaction. Under the optimum synthesis conditions, the obtained TCMP has a loose and porous structure. It was then used as a fiber coating material for solid-phase microextraction (SPME) of halogens-containing environmental hormones. It showed a strong adsorption capability due to the halogen bond, electrostatic, π-π stacking and hydrophobicity interactions. An analytical method combining the TCMP coated fiber-based SPME with gas chromatography-electron capture detection was developed to determine twelve halogens-containing environmental hormones in vegetable and fruit samples. A wide linear range (0.07-100.0 ng g-1) with the determination coefficients in the range of 0.9907-0.9996 and low limits of detection (0.02-0.04 ng g-1, S/N = 3) were achieved under optimized experimental conditions. The applicability of the established method was evaluated by the determination of the environmental hormones from three different fruit samples (apple, nectarine and pear) and five vegetable samples (Chinese cabbage, pakchoi, baby cabbage, rape and round lettuce). The resulting relative recoveries ranged from 76.6% to 123% with the relative standard deviations less than 10%. This research demonstrates the application potential of the TCMP coated fiber in the analysis of the halogens-containing environmental hormones in real vegetable and fruit samples.

Solid-phase microextraction of eleven organochlorine pesticides from fruit and vegetable samples by a coated fiber with boron nitride modified multiwalled carbon nanotubes.

A boron nitride modified multiwalled carbon nanotube material (BN@MWCNTs) was synthesized, and the synthesis conditions were optimized. The BN@MWCNTs was then used as the SPME fiber coating adsorbent for the extraction of eleven organochlorine pesticides (OCPs) from fruit and vegetable samples. Under the optimal conditions, the SPME coupled with the detection by GC-ECD had a linear response for the determination of the target analytes in the range of 0.03 to 200 ng g-1 with the coefficients of determination (r2) ≥ 0.9977. Based on the signal-to-noise ratios of 3 and 10, the limits of detection and the limits of quantification were measured to be 0.01-0.20 ng g-1 and 0.03-0.67 ng g-1, respectively. The relative recoveries of the analytes for spiked samples under three concentration levels (1.0, 10.0 and 100 ng g-1) were between 83.7% and 124% with the relative standard deviations ≤ 10.9%. The established method was successfully applied to the determination of OCPs in real fruit and vegetable samples.

Solid phase microextraction of polycyclic aromatic hydrocarbons from water samples by a fiber coated with covalent organic framework modified graphitic carbon nitride.

A covalent organic framework modified graphitic carbon nitride (g-C3N4@TpBD) was synthesized by modifying the graphitic carbon nitride (g-C3N4) with a covalent organic framework (COF-TpBD). The synthesis conditions including the mass ratio between g-C3N4 and benzidine (BD), solvent type, reaction temperature and reaction time were optimized. Under the optimal synthetic conditions, a novel spiny dendritic g-C3N4@TpBD adsorbent was obtained. The g-C3N4@TpBD was then coated on stainless-steel wire by sol-gel technique and the coated fiber was used for the solid phase microextraction of polycyclic aromatic hydrocarbons prior to gas chromatography-mass spectrometric detection. The established method was successfully applied to determine eight PAHs in six environmental water samples. Under the optimal extraction conditions, a wide linear quantification range for the analytes was obtained from 0.07 to 60.0 ng mL-1 with the coefficients of determination varying from 0.9979 to 0.9998, and the limits of detection (S/N = 3) ranged from 0.02 to 0.05 ng mL-1. The relative recoveries of the analytes for the six environmental water samples at the spiked concentrations of 0.2, 0.5, 3.0 and 30.0 ng mL-1 were between 83.6% and 118% with the relative standard deviations ranging from 2.4% to 11.3%.

Carbon nanospheres as solid-phase microextraction coating for the extraction of polycyclic aromatic hydrocarbons from water and soil samples.

A solid-phase microextraction with carbon nanospheres coated fiber coupled with gas chromatographic detection was established for the determination of eight polycyclic aromatic hydrocarbons (naphthalene, biphenyl, acenaphthene, fluorine, phenanthrene, anthracene, fluoranthene, and pyrene) in water and soil samples. The experimental parameters (extraction temperature, extraction time, stirring rate, headspace volume, salt content, and desorption temperature) which affect the extraction efficiency were studied. Under the optimized conditions, good linearity between the peak areas and the concentrations of the analytes was achieved in the concentration range of 0.5-300 ng/mL for water samples, and in the concentration range of 6.0-2700 ng/g for soil samples. The detection limits for the analytes were in the range of 0.12-0.45 ng/mL for water samples, and in the range of 1.53-2.70 ng/g for soil samples. The method recoveries of the polycyclic aromatic hydrocarbons for spiked water samples were 80.10-120.1% with relative standard deviations less than 13.9%. The method recoveries of the analytes for spiked soil samples were 80.40-119.6% with relative standard deviations less than 14.4%. The fiber was reused over 100 times without a significant loss of extraction efficiency.

Solid-phase microextraction of organophosphorous pesticides from food samples with a nitrogen-doped porous carbon derived from g-C3N4 templated MOF as the fiber coating.

A nitrogen-doped metal organic framework (MOF) based porous carbon (C-(C3N4@MOF)) was produced by the carbonization of a graphitic carbon nitride (g-C3N4) templated MOF (NH2-MIL-125). The C-(C3N4@MOF) was then coated on a stainless steel wire by sol-gel technique to serve as a solid-phase microextraction (SPME) fiber coating. The coated fiber was studied for the extraction of fourteen organophosphorous pesticides (OPPs) from different fruit and vegetable samples followed by gas chromatography-mass spectrometer (GC-MS) detection. The C-(C3N4@MOF) coated fiber exhibited a high extraction capability for the OPPs. Both single factor optimization and response surface analysis (Box-Behnken Design) methods were implemented to optimize the experiment conditions for the extraction. The results indicated that the linear response for the fourteen OPPs was in the range from 0.69 to 3000 ng g-1 and the coefficients of determination (r2) ranged from 0.9981 to 0.9998. The limits of detection (LODs, S/N = 3) ranged from 0.23 to 7.5 ng g-1. The method recoveries (R) of the fourteen OPPs for spiked fruit and vegetable samples were between 82.6% and 118%, with the relative standard deviations (RSDs) varying from 2.8% to 11.7%. The fiber can be reused over 100 times without a significant loss of extraction efficiency.

Fibrous boron nitride nanocomposite for magnetic solid phase extraction of ten pesticides prior to the quantitation by gas chromatography.

A fibrous magnetic boron nitride nanocomposite was synthesized and is shown to be a viable adsorbent for the magnetic solid phase extraction of pesticides prior to their quantitation by gas chromatography with electron capture detection. The optimum conditions were obtained by both single factor optimization and response surface analysis (Box-Behnken design). Under the optimized conditions, the response to the ten pesticides (dicofol, α-endosulfan, p,p'-DDE, nitrofen, ß-endosulfan, p,p'-DDD, p,p'-DDT, bifenthrin, permethrin and fenvalerate) is linear in the 0.03-40 ng·mL-1 concentration range with the coefficients of determination ranging from 0.9970 to 0.9992. The relative standard deviations at concentration levels of 0.5 ng·mL-1, 20 ng·mL-1 and 40 ng·mL-1 were below 8.7%. The recoveries of the analytes from spiked tea water and tea beverage samples varied between 84.5% and 122%, with relative standard deviations ranging from 4.8 to 12%. The limits of detection are between 0.01 and 0.05 ng·mL-1. The adsorbent can be reused over 50 times without significant loss of extraction efficiency. Graphical abstract A novel fibrous-shape magnetic boron nitride nanocomposite (Fe3O4@f-BN) was used as the adsorbent for the magnetic solid phase extraction (MSPE) of ten pesticides from tea water and tea beverage samples prior to their determination by gas chromatography (GC).

Covalent Organic Framework as Fiber Coating for Solid-Phase Microextraction of Chlorophenols Followed by Quantification with Gas Chromatography-Mass Spectrometry.

Headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry was adopted for the simultaneous determination of seven chlorophenols (CPs) from honey and canned-yellow-peach samples. A covalent organic framework made of 1,3,5-triformylphloroglucinol (Tp) and benzidine (BD) was used as the SPME fiber coating to preconcentrate the acetylation derivatives of the CPs. The main experimental parameters including derivatization conditions, extraction temperature and time, headspace volume, salt concentration, and desorption temperature were investigated. The fiber showed a high extraction capability for the CPs. The limits of detection (LODs) for the analytes were 0.3-0.7 µg kg-1 for honey and 0.8-1.8 µg kg-1 for canned-yellow-peach samples, suggesting good sensitivity for the method. The response linearity was 2.4-250 µg kg-1 for 2-CP and 3,4-CP and 1.0-150 µg kg-1 for the other remaining analytes in the honey samples. For the canned-yellow-peach samples, the response linearity was 6.0-300 µg kg-1 for 2-CP and 3,4-CP and 3.0-200 µg kg-1 for the others. The correlation coefficients were higher than 0.9919. Good repeatability (RSD < 11.9%) for the method and high recoveries (70.2-113%) of the analytes were observed under the optimal conditions. The established method was satisfactorily applied for the analysis of honey and canned-yellow-peach samples.

Determination of pesticides residues in vegetable and fruit samples by solid-phase microextraction with a covalent organic framework as the fiber coating coupled with gas chromatography and electron capture detection.

In this study, a covalent organic framework designated as TpPaNO2 was synthesized by a mechanochemical grinding method and then coated on stainless steel wire by a sol-gel technique to prepare a solid-phase microextraction fiber. The TpPaNO2 fiber based solid-phase microextraction coupled with gas chromatography-electron capture detection was applied to determine the residues of 11 pesticides (trlfuralln, dicofol, α-endosulfan, 1-chloro-4-[2,2-dichloro-1-(4-chlorophenyl)ethenyl]benzene, nitrofen, ß-endosulfan, 1-chloro-4-[2,2-dichloro-1-(4-chlorophenyl)ethyl]benzene, 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane, bifenthrin, permethrin and fenvalerate) in vegetable and fruit samples. The effects of extraction time, extraction temperature, sample pH, stirring rate and desorption temperature on the extraction efficiency were investigated. Under the optimized conditions, the limits of detection for the eleven pesticides were in the range of 0.04-0.25 µg/kg. The recoveries of the eleven pesticides in the vegetable and fruit samples were 81.5-111% with the relative standard deviations less than 11.2%.

Determination of volatile organic compounds in pen inks by a dynamic headspace needle trap device combined with gas chromatography-mass spectrometry.

Some harmful volatile organic compounds (VOCs), such as methylbenzene, ethylbenzene, xylene, chlorobenzene and bromobenzene, are the commonly found chemicals in pen inks. In this work, a dynamic headspace needle-trap device (D-HS-NTD) with a ZIF-8-derived nanoporous carbon (ZIF-8-NPC) as the adsorbent was developed for the extraction of some VOCs in different pen inks prior to GC-MS detection. The main important influencing experimental parameters including the flow rate of the purge gas N2, extraction temperature, extraction time, desorption temperature and desorption time for the extraction were optimized to obtain a high extraction efficiency. Under the optimized conditions, a good linearity was obtained in the concentration range of 0.1-400µgkg-1 with the correlation coefficients (r) ranging from 0.9911 to 0.9990 for the eleven VOCs. The LODs at a signal-to-noise ratio of 3 (S/N=3) were measured to be 10-20ngkg-1 for the VOCs. The developed method was applied to determine the VOCs from 20 pen inks. The recoveries of the VOCs for the method at the spiking levels of 0.5 and 20.0µgkg-1 fell in the range from 80.0% to 108%.

Micro-solid phase extraction of chlorophenols using reduced graphene oxide functionalized with magnetic nanoparticles and graphitic carbon nitride as the adsorbent.

A magnetic micro-solid phase extraction method was applied for the extraction of trace levels of various chlorophenols prior to their determination by high performance liquid chromatography. The reduced graphene oxide functionalized with magnetic iron oxide nanoparticles and graphitic carbon nitride was prepared and used as adsorbent. It was characterized by scanning electron microscope, X-ray diffraction and vibrating sample magnetometer. Placed in a polypropylene hollow tube, the material was applied to the extraction of 3-chlorophenol, 2,3-dichlorophenol, 2,4-dichlorophenol, and 2,4,6-trichlorophenol in cosmetic samples. Several experimental parameters that affect extraction efficiency were optimized. Following desorption with alkaline methanol, the chlorophenols were quantified by high performance liquid chromatography. A linear response was observed in the 1.0-200 µg·kg-1 CP concentration ranges. The detection limits (at a signal-to-noise ratio of 3) are between 0.20 and 0.30 µg·kg-1. The relative recoveries of the CPs from spiked cosmetics samples were in the range from 80.5 to 104%, with relative standard deviations lower than 12%. The filled extraction tube is high durable and stable. It can be used for 120 extraction cycles without a significant loss of extraction efficiency. The good adsorption ability of the sorbent was attributed to the strong π stacking interaction between the graphitic carbon nitride functionalized reduced graphene oxide and the aromatic rings in the CPs. Graphical abstract A magnetic micro-solid phase extraction (M-µSPE) method was applied to the extraction of various trace chlorophenols prior to their determination by high performance liquid chromatography. The M-µSPE method combines the advantages of both MSPE and µSPE.

Metal-organic framework UiO-67-coated fiber for the solid-phase microextraction of nitrobenzene compounds from water.

A sol-gel coating technique was applied for the preparation of a solid-phase microextraction fiber by coating the metal-organic framework UiO-67 onto a stainless-steel wire. The prepared fiber was explored for the headspace solid-phase microextraction of five nitrobenzene compounds from water samples before gas chromatography with mass spectrometric detection. The effects of the extraction temperature, extraction time, sample solution volume, salt addition, and desorption conditions on the extraction efficiency were optimized. Under the optimal conditions, the linearity was observed in the range of 0.015-12.0 µg/L for the compounds in water samples, with the correlation coefficients (r) of 0.9945-0.9987. The limits of detection of the method were 5.0-10.0 ng/L, and the recoveries of the analytes from spiked water samples for the method were in the range of 74.0-102.0%. The precision for the measurements, expressed as the relative standard deviation, was less than 11.9%.

Late-onset temperature reduction can retard the aging process in aged fish via a combined action of an anti-oxidant system and the insulin/insulin-like growth factor 1 signaling pathway.

Two different mechanisms are considered to be related to aging. Cumulative molecular damage caused by reactive oxygen species (ROS), the by-products of oxidative phosphorylation, is one of these mechanisms (ROS concept). Deregulated nutrient sensing by the insulin/insulin-like growth factor 1 (IGF-1) signaling (IIS) pathway is the second mechanism (IIS concept). Temperature reduction (TR) is known to modulate aging and prolong life span in a variety of organisms, but the mechanisms remain poorly defined. Here we first demonstrate that late-onset TR from 26 °C to 22 °C extends mean life span and maximum life span by approximately 5.2 and 3 weeks, respectively, in the annual fish Nothobranchius guentheri. We then show that TR is able to decrease the accumulation of the histological aging markers senescence-associated ß-galactosidase (SA-ß-Gal) in the epithelium and lipofuscin (LF) in the liver and to reduce protein oxidation and lipid peroxidation levels in the muscle. We also show that TR can enhance the activities of catalase, glutathione peroxidase, and superoxide dismutase, and stimulate the synthesis of SirT1 and FOXO3A/FOXO1A, both of which are the downstream regulators of the IIS pathway. Taken together, our findings suggest that late-onset TR, a simple non-intrusion intervention, can retard the aging process in aged fish, resulting in their life span extension, via a synergistic action of an anti-oxidant system and the IIS pathway. This also suggests that combined assessment of the ROS and IIS concepts will contribute to providing a more comprehensive view of the anti-aging process.

[The mRNA expression of BRCA1, ERCC1, TUBB3, PRR13 genes and their relationship with clinical chemosensitivity in primary epithelial ovarian cancer].

OBJECTIVE: To evaluate the expression of BRCA1, ERCC1, TUBB3 and PRR13 mRNA and their relationship with clinical chemosensitivity in primary ovarian cancer, and to assess the predictive value of joint detection of both BRCA1 and ERCC1 genes for the treatment of primary ovarian cancer. METHODS: Primary epithelial ovarian tumor samples were collected from 46 patients who underwent cytoreductive surgery. Real-time quantitative PCR was used to analyze the relative expression of BRCA1, ERCC1, TUBB3 and PRR13 mRNA in those cases. The correlation of clinical chemosensitivity and the test results was statistically analyzed. The efficacy of the joint prediction of clinical chemosensitivity by combining the two drug resistance gene detection was evaluated. RESULTS: The BRCA1 mRNA relative expression logarithm in the clinical-resistant group was 0.673±2.143, and clinical-sensitive group -1.436±2.594 (P=0.008). The ERCC1 mRNA relative expression logarithm in the clinical-resistant group was -0.529±1.982 and clinical-sensitive group -3.188±2.601 (P=0.001). BRCA1 and ERCC1 expression level is negatively correlated with platinum-based chemosensitivity. The PRR13 expressions in the two groups were not significantly different (P=0.074), and the TUBB3 expressions between the two groups were also not significantly different (P=0.619). When the intercept point value BRCA1 mRNA expression logarithm was -0.6, the predictive sensitivity, specificity, positive predictive value and negative predictive value were 73.3%, 75.0%, 84.6% and 60.0%, respectively, with the best comprehensive assessment. When the intercept point value of ERCC1 mRNA expression logarithm was -1, the predictive sensitivity, specificity, positive predictive value and negative predictive value were 80.0%, 68.8%, 82.8% and 64.7%, respectively, with the best comprehensive assessment. The combination detection of BRCA1 and ERCC1 can improve the chemotherapeutic sensitivity, specificity, positive predictive value and negative predictive value to 86.7%, 68.8%, 83.9% and 73.3%, respectively. CONCLUSIONS: BRCA1 and ERCC1 mRNA expression has a negative correlation with the clinical sensitivity of platinum-based chemotherapy. Combination detection of the two drug-resistance associated genes can improve the predictive efficacy of ovarian cancer chemosensitivity and beneficial to individual treatment of ovarian cancer.

[Predicting clinical chemo-sensitivity of primary ovarian cancer using adenosine triphosphate-tumor chemosensitivity assay combined with detection of drug resistance genes].

OBJECTIVE: To predict clinical chemotherapy sensitivity of primary ovarian cancer by jointing adenosine triphosphate (ATP)-tumor chemo-sensitivity assay (TCA) method in vitro and detection of drug resistance genes, provide reference for clinical treatment. METHODS: Forty-seven primary epithelial ovarian tumor samples were collected from the patients who received cytoreductive surgery. Viable ovarian cancer cells obtained from malignant tissue were tested for their sensitivity to carboplatin (CBP), cisplatin (DDP), paclitaxel (PTX) and CBP + PTX using ATP-TCA method in vitro; at same time, real-time quantitative PCR was used to analysis BRCA1 and ERCC1 mRNA relative expression in forty-six specimens (1 frozen tumor samples mRNA were not detected due to serious degradation). The relationship between ATP-TCA test results, clinical indicators, and the effectiveness of the joint prediction on clinical chemo-sensitivity by combining these two methods were statistically analyzed using chi-square test. RESULTS: (1) The results showns that three programs of DDP, CBP and PTX + CBP were significantly related with clinical results (P < 0.05) in vitro, in which the compliance rate in PTX + CBP program was the highest 83% (39/47), and the predictive sensitivity, predictive specificity, positive predictive value, negative predictive value and predictive accurate rate were 90%, 71%, 84% and 80%, respectively. PTX + CBP combined in vitro test results was also related with residual tumor size and neoadjuvant chemotherapy, which was more prone to drug resistance with residual tumor larger than 2 cm (P = 0.023) and with neoadjuvant chemotherapy (P = 0.011). (2) BRCA1 mRNA expression levels in the clinical-resistant group and the clinical-sensitive group was 0.673 ± 2.143 and -1.436 ± 2.594 (P = 0.008), ERCC1 mRNA expression levels in the clinical-resistant group and the clinical-sensitive group was -0.529 ± 1.982 and -3.188 ± 2.601 (P = 0.001). There were also significant correlation among the expression levels of BRCA1, ERCC1 mRNA and clinical efficacy (P < 0.01). (3) ATP-TCA and detection of drug resistance genes combined to predict the clinical application of PTX + CBP resistance may occur in 8/9 cases. CONCLUSIONS: ATP-TCA may be an ideal method of in vitro drug sensitivity testing method, which could effectively predict clinical chemotherapy sensitivity. Combination of the drug-resistant associated genes detection method and the ATP-TCA method can increase the predictive effectiveness of ovarian cancer chemosensitivity and guide individual chemotherapy of ovarian cancer.

Ultrasound-assisted surfactant-enhanced emulsification microextraction for the determination of carbamate pesticides in water samples by high performance liquid chromatography.

A novel ultrasound-assisted surfactant-enhanced emulsification microextraction (UASEME) coupled with high performance liquid chromatography-diode array detection has been developed for the extraction and determination of six carbamate pesticides (metolcarb, carbofuran, carbaryl, pirimicarb, isoprocarb and diethofencarb) in water samples. In the UASEME technique, Tween 20 was used as emulsifier, and chlorobenzene and chloroform were used as dual extraction solvent without using any organic dispersive solvent that is normally required in the previously described common dispersive liquid-liquid microextraction method. Parameters that affect the extraction efficiency, such as the kind and volume of the extraction solvent, the type and concentration of the surfactant, ultrasound emulsification time and salt addition, were investigated and optimized for the method. Under the optimum conditions, the enrichment factors were in the range between 170 and 246. The limits of detection of the method were 0.1-0.3 ng mL(-1) and the limits of quantification were between 0.3 and 0.9 ng mL(-1), depending on the compounds. The linearity of the method was obtained in the range of 0.3-200 ng mL(-1) for metolcarb, carbaryl, pirimicarb, and diethofencarb, 0.6-200 ng mL(-1) for carbofuran, and 0.9-200 ng mL(-1) for isoprocarb, with the correlation coefficients (r) ranging from 0.9982 to 0.9998. The relative standard deviations varied from 3.2 to 4.8% (n=5). The recoveries of the method for the six carbamates from water samples at spiking levels of 1.0, 10.0, 50.0 and 100.0 ng mL(-1) were ranged from 81.0 to 97.5%. The proposed UASEME technique has demonstrated to be simple, practical and environmentally friendly for the determination of carbamates residues in river, reservoir and well water samples.

[Application of ATP-tumor chemosensitivity assay in recurrent epithelial ovarian cancer].

OBJECTIVE: To explore the value of adenosine triphosphate-tumor chemosensitivity assay (ATP-TCA) in individualized treatment of recurrent epithelial ovarian cancer (REOC), and to evaluate the correlation between the in vitro chemosensitivity assay and clinical drug sensitivity. METHODS: Sixty-nine REOC specimens were tested by ATP-TCA assay retrospectively. The patients were divided into strong sensitive, moderate sensitively and resistant groups according to the ATP-TCA assay results. The clinical results were evaluated according to imaging and serum CA125 analysis. The correlation between in vitro ATP-TCA assay and clinical outcome was statistically analyzed by χ(2) test. The progression free survival (PFS) and overall survival (OS) of each group were analyzed using Kaplan-Meier method. RESULTS: The results of ATP-TCA assay had significant correlation with clinical outcome. The clinical chemotherapy outcome became better with increased drug sensitivity in vitro (χ(2) = 9.066, P = 0.004). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy rate for ATP-TCA method to predict the clinical chemotherapy sensitivity of REOC were 87.5%, 45.9%, 58.3%, 80.9% and 65.2%, respectively. The mean PFS of strong sensitive group, moderately sensitive group and resistant group were 187.1 days, 195.0 days and 60.3 days, respectively. The mean OS were 476.7, 335.7 and 237.5 days, respectively, following the start of TCA-directed therapy. The PFS and OS of the two sensitivity groups in vitro were significantly longer than that of the in vitro-resistant group (P < 0.01). CONCLUSION: The results of ATP-TCA assay are well correlated with clinical treatment responses. The assay may be an important and useful method for individualized chemotherapy for recurrent ovarian cancer.

Efficient disinfection of Escherichia coli in water by silver loaded alumina.

The catalytic inactivation of Escherichia coli (E. coli) in water by silver loaded alumina as catalyst was investigated. Ag/Al(2)O(3) and AgCl/Al(2)O(3) catalysts exhibited high bactericidal activity at room temperature in water with no need for any light or electrical power input. Dissolved oxygen which can be catalyzed to reactive oxygen species (ROS) was found to be essential for the strong bactericidal activities of the catalysts. Decomposition of the cell wall leading to leakage of the intracellular component and the complete lysis of the whole cell were directly observed by transmission electron microscopy (TEM). The resultant change in cell permeability was confirmed by potassium ion leakage. The different morphological changes between E. coli cells treated with the catalysts and Ag(+) were also observed. The formation of ROS involved in the bactericidal process by AgCl/Al(2)O(3) was confirmed by addition of catalase and ()OH scavenger. Higher temperature and pH value were found to have positive effect on the bactericidal activity of AgCl/Al(2)O(3). All these results indicated that the bactericidal effect of the catalyst was a synergic action of ROS and Ag(+), not an additive one. A possible mechanism is proposed.

Bactericidal activity of a Ce-promoted Ag/AlPO4 catalyst using molecular oxygen in water.

The catalytic inactivation of Escherichia coli in water by a cerium (Ce)-promoted silver-loaded aluminum phosphate (Ag/ AlPO4) catalyst using molecular oxygen was investigated. With optimum Ce content, the Ag(Ce)/AlPO4 catalyst exhibited strong bactericidal activity. The process of decomposition of the cell wall and cell membrane was directly observed by TEM. The different morphological changes of E. coli cells treated with the Ag(Ce)/AlPO4 catalyst and those treated with Ag+ suggested that the Ag+ eluted from the catalyst surface did not play an important role during the bactericidal process. Results of DMPO spin-trapping measurements by electron spin resonance (ESR) indicated the formation of the reactive oxygen species (ROS) *OH and *O2-, which caused the considerable bactericidal activity. The formation of H2O2 acted as an important intermediate; this was confirmed by addition of catalase as the scavenger. A possible catalytic oxidation bactericidal mechanism using molecular oxygen was proposed for the Ag(Ce)/AlPO4 catalyst.