A dual-mode "signal-on" split-type aptasensor for bisphenol A via target-induced hybridization chain reaction amplification.

Herein, a dual-mode detection system was constructed for efficient and accurate detection of bisphenol A (BPA) with the assistance of the BPA-induced hybridization chain reaction (HCR). The captured DNA (cDNA) was first modified on the surface of magnetic spheres modified with gold nanoparticles and polydopamine and then hybridized with the BPA aptamer to form double-stranded DNA (dsDNA). In the presence of the BPA target, the BPA aptamer was released from the surface of the magnetic sphere. The free cDNA triggered a HCR to construct a DNA duplex. Methylene blue (MB), as a bifunctional probe, was intercalated into the double-stranded DNA to amplify the photocurrent (IPEC) of the CdS-modified electrode and generate an electrochemical current (IEC) at the same time. Under the optimized conditions, the PEC and EC signal responses of the system were linear to the logarithm of BPA concentration in the range of 1.0 × 10-10 M to 1.0 × 10-5 M. The detection limits were found to be 1.27 × 10-11 M and 3.0 × 10-11 M using the PEC and EC methods, respectively. The constructed dual-mode biosensor exhibited good performance for real sample analysis, demonstrating its promising potential for practical applications. In addition, this dual-mode detection strategy provides more accurate and reliable detection results.

Competitive Displacement Triggering DBP Photoelectrochemical Aptasensor via Cetyltrimethylammonium Bromide Bridging Aptamer and Perovskite.

Here, a label-free perovskite-based photoelectrochemical (PEC) aptasensor was rationally designed for the displacement assay of dibutyl phthalate (DBP), a well-known endocrine disruptor, with the aid of cetyltrimethylammonium bromide (CTAB). In this method, CTAB significantly enhanced the PEC response and humidity resistance of the CH3NH3PbI3 perovskite by forming a protecting layer and passivating the X- and A-sites vacancies of CH3NH3PbI3. In addition, CTAB facilitated the immobilization of an aptamer through van der Waals and hydrophobicity forces, as well as the electrostatic interactions between the phosphate group of the aptamer and the cationic group of CTAB. When exposed to DBP in the affinity solution, the DBP aptamer was released from the electrode because the affinity between DBP and its aptamer competes with the interaction of the aptamer and CTAB. The displacement of the aptamer from the perovskite surface relieves the block effect and thus enhances the photoelectric signal of perovskite. By virtue of the good photoelectrochemical characters of CH3NH3PbI3 and the specific recognition ability of aptamer, the linear range of the PEC sensor was 1.0 × 10-13 to 1.0 × 10-8 M and the detection and quantification limits were down to 2.5 × 10-14 and 8.2 × 10-14 M (S/N = 3), respectively. This work offers a novel strategy for designing aptasensors for the detection of various targets and exhibits the marvelous potential of organic-inorganic perovskite in the field of PEC analysis.

High-sensitivity photo-electrochemical heterostructure of the cuprous oxide-metal organic framework for a dioctyl phthalate molecularly imprinted sensor.

This work designed a novel dioctyl phthalate (DOP) photoelectrochemical (PEC) sensor based on a molecularly imprinted polymer (MIP) modified Cu3(BTC)2@Cu2O heterostructure. In this work, a metal organic framework (MOF), Cu3(BTC)2, was coated on Cu2O through a simple immersion method to form a Cu3(BTC)2@Cu2O heterostructure. The heterostructure exhibited strong light adsorption ability, good stability and enhanced photocurrent under visible light irradiation. Using the Cu3(BTC)2@Cu2O heterostructure as the photoelectric converter, a PEC sensor was constructed by imprinting DOP on the heterostructure. Under the optimal experimental conditions, the PEC sensor showed a wide linear range from 25.0 pM-0.1 µM and a low detection limit of 9.15 pM. This method with good sensitivity, stability, selectivity and reproducibility in actual sample analyses showed promising applications of the MOF-based heterostructure in photoelectrochemical analysis fields.

CPAP treatment in REM-related obstructive sleep apnea: a distinct clinical phenotype of sleep disordered breathing.

PURPOSE: REM-related obstructive sleep apnea (REM-OSA), as defined using revised apnea-hypopnea index (AHI) criteria, might represent a specific OSA phenotype. However, there is a lack of data on outcomes of treatment in this population. This study evaluated the effects of CPAP treatment over 12 months on clinical outcomes for patients with the polysomnography phenotype of REM-OSA. METHODS: We conducted a prospective observational study with the following inclusion criteria: subjective sleepiness and diagnostic polysomnography demonstrating AHIREM≥15 events/h, AHINREM<5 events/h, and ≥ 30 min of REM sleep. Clinical outcomes assessed included Epworth Sleepiness Scale (ESS), psychomotor vigilanc test reaction time (PVT-RT), and CPAP adherence at baseline, 1, 3, 6, and 12 months; Functional Outcomes of Sleep Questionnaire (FOSQ) and Depression Anxiety Stress Scales (DASS-21) at baseline, 1, 3 and 12 months. The reason is the first 3 outcomes (ESS, PVT, adherence) were assessed at baseline, 1, 3, 6, and 12 months, while the next 2 outcomes (FOSQ, DASS) were assessed at baseline, 1, 3, and 12 months. The edited version is not as clear in separating these outcomes into 2 groups; Functional Outcomes of Sleep Questionnaire (FOSQ); and Depression Anxiety Stress Scales (DASS-21) at baseline, 1, 3, and 12 months. Linear mixed effects models were used to investigate the joint effects of time and average CPAP adherence on our outcomes of interest. RESULTS: Twenty participants completed a minimum of 1 month of CPAP treatment and were included for analysis. During the trial, 8 participants discontinued CPAP (4 before 3 months, 1 before 6 months, 3 before 12 months), and 19 participants completed 12 months of treatment. Baseline ESS was elevated at 12.6 units. Average CPAP usage for all 27 participants over 12 months was 2.9 ± 2.4 h. There was a significant decrease in ESS and increase in FOSQ at all time points, and the decrease in ESS was only seen in the CPAP-adherent subgroup. Decreases in DASS-21 and PVT-RT were not sustained. CONCLUSIONS: CPAP treatment in sleepy patients with moderate to severe REM-OSA is associated with reduced sleepiness and improved quality of life. TRIAL REGISTRATION: The trial was registered in the Australian New Zealand Clinical Trials Registry: ACTRN12620000576921, 18/05/2020 (retrospectively registered).

A generalizable sensing platform based on molecularly imprinted polymer-aptamer double recognition and nanoenzyme assisted photoelectrochemical-colorimetric dual-mode detection.

Developing highly sensitive and selective methods that incorporate specific recognition elements is crucial for detecting small molecules because of the limited availability of small molecule antibodies and the challenges in obtaining sensitive signals. In this study, a generalizable photoelectrochemical-colorimetric dual-mode sensing platform was constructed based on the synergistic effects of a molecularly imprinted polymer (MIP)-aptamer sandwich structure and nanoenzymes. The MIP functionalized peroxidase-like Fe3O4 (Fe3O4@MIPs) and alkaline phosphatase mimic Zr-MOF labeled aptamer (Zr-mof@Apt) were used as the recognition elements. By selectively accumulating dibutyl phthalate (DBP), a small molecule target model, on Fe3O4@MIPs, the formation of Zr-MOF@Apt-DBP- Fe3O4@MIPs sandwich structure was triggered. Fe3O4@MIPs oxidized TMB to form blue-colored oxTMB. However, upon selective accumulation of DBP, the catalytic activity of Fe3O4@MIPs was inhibited, resulting in a lighter color that was detectable by the colorimetric method. Additionally, Zr-mof@Apt effectively catalyzed the hydrolysis of L-Ascorbic acid 2-phosphate sesquimagnesium salt hydrate (AAPS), generating ascorbic acid (AA) that could neutralize the photogenerated holes to decrease the photocurrent signals for PEC sensing and reduce oxTMB for colorimetric testing. The dual-mode platform showed strong linearity for different concentrations of DBP from 1.0 pM to 10 µM (PEC) and 0.1 nM to 0.5 µM (colorimetry). The detection limits were 0.263 nM (PEC) and 30.1 nM (colorimetry) (S/N = 3), respectively. The integration of dual-signal measurement mode and sandwich recognition strategy provided a sensitive and accurate platform for the detection of small molecules.

ß-Bi2O3 Nanosheets Functionalized with Bisphenol A Synthetic Receptors: A Novel Material for Sensitive Photoelectrochemical Platform Construction.

In this study, ß-Bi2O3 nanosheets functionalized with bisphenol A (BPA) synthetic receptors were developed by a simple molecular imprinting technology and applied as the photoelectric active material for the construction of a BPA photoelectrochemical (PEC) sensor. BPA was anchored on the surface of ß-Bi2O3 nanosheets via the self-polymerization of dopamine monomer in the presence of a BPA template. After the elution of BPA, the BPA molecular imprinted polymer (BPA synthetic receptors)-functionalized ß-Bi2O3 nanosheets (MIP/ß-Bi2O3) were obtained. Scanning electron microscopy (SEM) of MIP/ß-Bi2O3 revealed that the surface of ß-Bi2O3 nanosheets was covered with spherical particles, indicating the successful polymerization of the BPA imprinted layer. Under the best experimental conditions, the PEC sensor response was linearly proportional to the logarithm of BPA concentration in the range of 1.0 nM to 1.0 µM, and the detection limit was 0.179 nM. The method had high stability and good repeatability, and could be applied to the determination of BPA in standard water samples.

Ultrasensitive alkaline phosphatase activity assay based on controllable signal probe production coupled with the cathodic photoelectrochemical analysis.

A highly sensitive and selective split-type perovskite-based photoelectrochemical (PEC) platform was developed for measuring alkaline phosphatase (ALP) activity in milk and serum samples. ALP in the test sample hydrolyzed 2-phosphate sesquimagnesium salt hydrate (AAPS) in a 96-microwell plate to produce ascorbic acid (AA), a PEC electron donor. The resulting AA, which could preferentially annihilate the photogenerated holes, indirectly reflects ALP activity. The PEC used a cetyltrimethylammonium bromide (CTAB)-functionalized CH3NH3PbI3 (CTAB@CH3NH3PbI3) film as the cathode to monitor the controlled AA production. Due to the excellent photoelectric characteristics of the CH3NH3PbI3 perovskite and the split-type assay, excellent sensitivity and selectivity for ALP detection were obtained. Under the optimum experimental conditions, ALP activity with a limit of detection (LOD) of 2.6 × 10-4 U/L in a linear dynamic range of 10-3 âˆ¼ 102 U/L was obtained. With its sensitive, rapid, and high-throughput detection capabilities, this split-type and label-free PEC platform has great potential for use in food and biomedical analysis.

Flexible Electrochemical Platform Coupled with In Situ Prepared Synthetic Receptors for Sensitive Detection of Bisphenol A.

A flexible electrochemical sensor based on the carbon felt (CF) functionalized with Bisphenol A (BPA) synthetic receptors was developed. The artificial Bisphenol A receptors were grafted on the CF by a simple thermal polymerization molecular imprinting process. Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and electrochemical characterizations were used to analyze the receptors. Characterization results demonstrated that the Bisphenol A synthetic receptors successfully formed on the CFs surface. Because the synthetic receptor and the porous CFs were successfully combined, the sensor displayed a better current response once Bisphenol A was identified. The sensor's linear range was determined to be from 0.5 to 8.0 nM and 10.0 to 300.0 nM, with a detection limit of 0.36 nM. Even after being bent and stretched repeatedly, the electrode's performance was unaffected, demonstrating the robustness, adaptability and viability of installing the sensor on flat or curved surfaces for on-site detection. The designed electrochemical sensor has been used successfully to identify Bisphenol A in milk samples with satisfactory results. This work provided a promising platform for the design of implantable, portable and miniaturized sensors.

A highly-specific photoelectrochemical platform based on carbon nanodots and polymers functionalized organic-inorganic perovskite for cholesterol sensing.

Herein, we reported the introduction of carbon nanodots (CNDs) and polyvinylidene fluoride (PVDF) as additives into perovskite CH3NH3PbI3 through in situ synthesis to prepare PVDF-CH3NH3PbI3@CNDs composite, which demonstrated improved water tolerance and mechanical stability. The application of PVDF-CH3NH3PbI3@CNDs for photoelectrochemical sensing was then explored. A molecularly imprinted polymer (MIP) that could specifically recognize cholesterol (CHO) was anchored to PVDF-CH3NH3PbI3@CNDs via a simple thermal polymerization process, followed by elution with hexane. A label-free and sensitive photoelectrochemical method for CHO detection was achieved by using the MIPs@PVDF-CH3NH3PbI3@CNDs platform. The detection limit for CHO was 2.1 × 10-14 mol/L, lower than most of the existing CHO detection methods. In our perception, this platform can be extended to numerous other analytes. This research result may provide a new understanding to improve the performance and broaden the application range of organic-inorganic perovskites.

[Risk factors for ventilator-associated pneumonia in neonates and the changes of isolated pathogens].

OBJECTIVE: To study the risk factors for neonatal ventilator-associated pneumonia (VAP) and the changes of isolated pathogens in the last eight years. METHODS: The clinical data of 230 neonates who were admitted into the neonatal intensive care unit (NICU) and received mechanical ventilation for equal to or longer than 48 hrs in 2008 were retrospectively reviewed. The isolated pathogens were compared with those of eight years ago. RESULTS: The incidence of VAP (25.2%) in the year 2008 was lower than that of eight years ago (36.1%; P<0.05). The development of VAP was negatively correlated with the gestational age and the birth weight, but positively correlated with the duration of mechanical ventilation, intubation times, duration of hospitalization, presence of gastrointestinal bleeding and need for blood products transfusion. The main isolated pathogens were opportunistic antibiotics resistant bacteria, and the majority was gram negative bacilli (77%). The most frequently detected gram negative bacilli were Klebsiella (20%), Stenotrophomonas maltophilia (18%) and Acinetobacter (13%). Streptococcus mitis was the most frequently detected gram positive bacilli (14%). The distribution pattern of pathogens isolated in the same NICU eight years ago was somewhat different: Klebsiella (23%), Pseudomonas aeruginosa (17%), Acinetobacter (16%), Streptococcus mitis (11%), Fungi (1%) and Candida albicans (1%). CONCLUSIONS: The incidence of VAP is correlated with gestational age, birth weight, duration of mechanical ventilation and hospitalization, intubation times, presence of gastrointestinal bleeding and need for blood products transfusion. The main isolated pathogens are usually antibiotic resistant opportunistic bacteria. The detection rate of Stenotrophomonas maltophilia increased and that of Pseudomonas aeruginosa decreased when compared with eight years ago.

A flexible rGO electrode: a new platform for the direct voltammetric detection of salicylic acid.

Flexible sensors are of considerable interest for the development of wearable smart miniature devices. This work reported a flexible electrochemical platform based on reduced graphene oxide (rGO) for the detection of salicylic acid (SA). The free-standing and flexible rGO electrode was prepared via a simple extruded process. Dynamic mechanical deformation and bending studies illustrated the resilience and compliance of the flexible electrode against extreme mechanical deformations. Quantitative analysis of SA was performed by using differential pulse voltammetry (DPV) with this flexible rGO electrode. Linearity ranges for SA were obtained from 1.0 × 10-10 M to 1.0 × 10-5 M with the detection limit of 2.3 × 10-11 M (S/N = 3). This strategy provided a new insight into the design and application of flexible electrodes. It will extend the applications of rGO in sensing, bio-electronics and lab-on-chip devices.

Monolithic silica xerogel capillary column for separations in capillary LC and pressurized CEC.

Monolithic capillary columns were prepared by the reaction of a mixture of potassium silicate solution and formamide. The surface of the monolith was coated with a thin film formed by a sol-gel method to increase the surface area of the monolith and simultaneously covered with C8 as stationary phase for reversed-phase separation. The morphology of the monolithic column was investigated by SEM. Monolithic columns prepared in this manner showed high permeability and can be operated in capillary LC (CLC) mode at a pressure of 20 psi. PAHs were used to evaluate the separation performance of the stationary phase using CLC and pressurized CEC (pCEC). Efficiencies of 20 000 and 28 000 plates per meter for naphthalene were obtained in CLC and pCEC modes, respectively. Improvement in column efficiency and reduction in analysis time over CLC and improvement in operation facility and separation selectivity over CLC were found using pCEC mode.

Antidepressant effect of venlafaxine in chronic unpredictable stress: Evidence of the involvement of key enzymes responsible for monoamine neurotransmitter synthesis and metabolism.

A number of studies have linked abnormalities in the function of the serotonergic and noradrenergic systems to the pathophysiology of depression. It has been reported that selective serotonin reuptake inhibitors promote the expression of tryptophan hydroxylase (TPH), which is involved in the synthesis of serotonin. However, limited evidence of TPH alteration has been found in selective serotonin and noradrenaline reuptake inhibitors (SNRIs), and more key enzymes need to be investigated. The aim of the present study was to determine whether venlafaxine (VLX; a classical SNRI) regulates TPH and other key enzymes responsible for the synthesis and metabolism of monoaminergic transmitters in rats with chronic unpredictable stress (CUS). The present results suggested that CUS­exposed rats exhibited decreased locomotor activity in the open­field test and increased immobility time in the forced swim test, as compared with the controls. Pretreatment with VLX (20 mg/kg) significantly increased locomotor activity and reduced immobility time in the CUS­exposed rats. In addition, VLX (20 mg/kg) treatment prevented the CUS­induced reduction in tyrosine hydroxylase and TPH expression in the cortex and hippocampus. Furthermore, VLX alleviated the CUS­induced oxidative stress in the serum, cortex and hippocampus. However, VLX administration did not have an effect on indoleamine­2,3­dioxygenase overexpression in the hippocampus. It was therefore concluded that the regulation of abnormalities in the synthesis and metabolism of monoaminergic transmitters may be associated with the antidepressant effects of VLX, suggesting that multimodal pharmacological treatments can efficiently treat depression.

Antidepressant mechanisms of venlafaxine involving increasing histone acetylation and modulating tyrosine hydroxylase and tryptophan hydroxylase expression in hippocampus of depressive rats.

Venlafaxine (VEN) is a widely used antidepressant as a serotonin-reuptake and norepinephrine-reuptake inhibitor. It is used primarily in depression, especially with generalized anxiety disorder or chronic pain. This medicine is of interest because its mechanisms involved multiple aspects. In the current study, the antidepressant action of VEN was investigated by studying the histone acetylation and expression of tyrosine hydroxylase (TH) and tryptophan hydroxylase (TPH) in rats exposed to chronic unpredicted stress (CUS) for 28 days. Male Sprague-Dawley rats were divided into a control group, VEN-treated control group, CUS group, and VEN-treated CUS group. VEN (23.4 mg/kg once daily) was administered to rats by intragastric gavage, whereas the same volume of vehicle was given to rats in the control and model groups. Rat behaviors, acetylated H3 at lysine 9 (acH3K9), acetylated H3 at lysine 14 (acH3K14), acetylated H4 at lysine 12 (acH4K12), histone deacetylase 5, and TH and TPH expression in the hippocampus were determined. Chronic VEN treatment significantly relieved the anxiety- and depression-like behaviors, prevented the increase of histone deacetylase 5 expression and decrease of acH3K9 level, and promoted TH and TPH protein expression in the hippocampus of CUS rats. The results suggest that the preventive antidepressant mechanism of VEN is partly involved in the blocking effects on histone de-acetylated modification and then increasing TH, TPH expression.

Gold microspheres modified with octadecanethiol for capillary liquid chromatography.

Monodispersed spherical gold particles synthesized and modified with n-octadecanethiol (C18-Au) were packed into a 100 microm I.D. capillary column and tested in capillary high-performance liquid chromatography (microHPLC). To the best of our knowledge, this represents the first report on the actual use of micron gold particles as stationary phase in a packed column microHPLC. As measured by scanning electron microscopy, the average diameter of these gold microspheres was 3.5 microm and the surface area, average pore diameter, and average pore volume were 49.4m(2)/g, 4.8 nm, and 0.12 cm(3)/g, respectively. The retention behavior of neutral compounds on the n-octadecanethiol-modified gold microspheres was investigated by separating a mixture of small organic compounds using microHPLC. The results from the experiments show that C18-Au behaves basically as a reversed phase. The test of chemical stability of the C18-Au stationary phase under alkaline condition demonstrates that it is stable with the flushing of a mobile phase at pH 12 for at least 140 h. The C18-Au particles are also mechanically strong enough to withstand pressure up to 52 MPa. The preliminary results in this work prove the feasibility of the fabrication of C18-Au micron particles as a novel stationary phase for packed column microHPLC.

Pressurized capillary electrochromatographic assay of trimethoprim impurities using 1 microm particle-based columns.

One micrometre silica particles, derivatized with C18, were electrokinetically packed into a 75-microm-i.d. capillary. The resulting column was evaluated for the separation of trimethoprim (TMP) and its impurities using pressurized capillary electrochromatography (pCEC), starting from a capillary liquid chromatographic (CLC) separation. These samples require gradient elution when separated by high performance liquid chromatography (HPLC), but with the new columns isocratic elution suffices for their separation by CLC or pCEC. Only 70,000 theoretical plates/m for impurity C were achieved using CLC mode at relative low pressure (78 bar) although very small particles were utilized. When a voltage above 2 kV (50 V/cm) was applied, unknown peaks appeared, which was assumed due to an electrophoretic effect with the unknown peaks resolving as a result of the applied voltage. In order to minimize these unfavorable contributions, only a low voltage was applied, still leading to higher separation performances and shorter separation times than in CLC. The optimal analyzing conditions in pCEC included a pressure of 78 bar, an applied voltage of 1 kV, and a mobile phase consisting of 80 mM sodium perchlorate (pH 3.1)/methanol (60/40, v/v). These conditions were used to separate and quantify four major impurities in TMP within 22 min. The obtained calibration curves were linear (r>0.9980) in concentration ranges between 0.005 and 0.1 mg/mL for impurities A and C; 0.02 and 0.10 mg/mL for impurity F; and 0.01 and 0.10 mg/mL for impurity H. The detection limits (S/N=3) for impurities A, C, F, and H were 0.52, 0.84, 3.18, and 2.41 microg/mL, respectively. The calibration curves were successfully applied to analyze spiked bulk samples, with mean recoveries ranging from 92% to 110%. The developed method can therefore be considered simple, rapid, and repeatable.

The simultaneous separation and determination of six flavonoids and troxerutin in rat urine and chicken plasma by reversed-phase high-performance liquid chromatography with ultraviolet-visible detection.

The method of high-performance liquid chromatography (HPLC) with UV-vis detection was used and validated for the simultaneous determination of six flavonoids (puerarin, rutin, morin, luteolin, quercetin, kaempferol) and troxerutin in rat urine and chicken plasma. Chromatographic separation was performed using a VP-ODS column (150 mm x 4.6 mm, 5.0 microm) maintained at 35.0 degrees C. The mobile phase was a mixture of water, methanol and acetic acid (57:43:1, v/v/v, pH 3.0) at the flow rate of 0.8 mL/min. Six flavonoids and troxerutin were analyzed simultaneously with good separation. On optimum conditions, calibration curves were found to be linear with the ranges of 0.10-70.00 microg/mL (puerarin, rutin, morin, luteolin, quercetin, kaempferol) and 0.50-350.00 microg/mL (troxerutin). The detection limits were 0.010-0.050 microg/mL. The method was validated for accuracy and precision, and it was successfully applied to determine drug concentrations in rat urine and chicken plasma samples from rat and chicken that had been orally administered with six flavonoids and troxerutin.

Knockdown of UHRF1 by lentivirus-mediated shRNA inhibits ovarian cancer cell growth.

Human UHRF1 (ubiquitin-like PHD and RING finger domain-containing 1) has been reported to be over-expressed in many cancers, but its role in ovarian cancer remains elusive. Here, we determined whether knockdown of UHRF1 by lentivirus-mediated shRNA could inhibit ovarian cancer cell growth. Lentivirus- mediated short hairpin RNAs (lv-shRNAs-UHRF1) were designed to trigger the gene silencing RNA interference (RNAi) pathway. The efficiency of lentivirus-mediated shRNA infection into HO-8910 and HO-8910 PM cells was determined using fluorescence microscopy to observe lentivirus-mediated GFP expressionand was confirmed to be over 80 percent. UHRF1 expression in infected HO-8910 and HO-8910 PM was evaluated by real-time PCR and Western blot analysis. The Cell Counting Kit-8 (CCK-8) assay was used to measure cell viability; flow cytometry and Hoechst 33342 assay was applied to measure cell cycle arrest and apoptosis. Cell invasion was assessed using transwell chambers. Our results demonstrated that the loss of UHRF1 promoted HO-8910 and HO-8910 PM cell apoptosis, while inhibiting cell proliferation. In addition, UHRF1 knockdown significantly inhibited the invasion of human ovarian cancer cells. In the present study, we also showed that depleting HO-8910 cells of UHRF1 caused activation of the DNA damage response pathway, with the cell cycle arrested in G2/M-phase. The DNA damage response in cells depleted of UHRF1 was illustrated by phosphorylation of CHK (checkpoint kinase) 2 on Thr68, phosphorylation of CDC25 (cell division control 25) on Ser 216 and phosphorylation of CDK1 (cyclin-dependent kinase 1) on Tyr 15.

Enhancing tyrosine hydroxylase and tryptophan hydroxylase expression and improving oxidative stress involved in the antidepressant effect of sodium valproate on rats undergoing chronic unpredicted stress.

Depression is a common worldwide mental disorder whose etiology remains unclear; there is also a lack of effective therapeutic agents. Sodium valproate (VPA) is a traditional antiepileptic drug with mood-stabilization effect and is increasingly being used to treat bipolar disorders and depression, but its antidepressant mechanism remains unknown. The aim of the present study was to investigate the possible mechanisms of antidepressant action by studying malondialdehyde level, catalase, and superoxide dismutase activities in the serum and the mRNA and protein expression of tyrosine hydroxylase (TH) and tryptophan hydroxylase (TPH) in the prefrontal cortex of rats exposed to chronic unpredicted stress (CUS). Male Sprague-Dawley rats were used to establish a depression model by CUS. VPA (300 mg/kg once daily) and an equivalent volume of vehicle were administered to rats by an intragastric gavage. Rat behaviors, serum malondialdehyde level, serum catalase and superoxide dismutase activities, and the mRNA and protein expressions of TH and TPH in the prefrontal cortex were determined. The results showed that VPA treatment led to a significant decrease in depression-like behaviors, improvement in oxidative stress imbalance, and enhancement of TH, TPH mRNA, and protein expression in stressed rats, but failed to show any significant changes in control rats. This could indicate that the antidepressant mechanism of VPA is perhaps linked to upregulation of TH and TPH expression and inhibition of oxidative damage in CUS rats.

Differential pulse adsorption voltammetry for determination of procaine hydrochloride at a pumice modified carbon paste electrode in pharmaceutical preparations and urine.

Procaine hydrochloride was determined by the differential pulse voltammetry (DPV) using a 6% (m/m) pumice modified carbon paste electrode in 1.25 x 10(-3) mol x l(-1) KH(2)PO(4) and Na(2)HPO(4) buffer solution (pH 6.88, 25 degrees C). The anodic peak potential used was +0.980 V (vs. SCE). A good linear relationship was realized between the anodic peak current and procaine concentration in the range of 9.0 x 10(-7)-2.6 x 10(-5) mol x l(-1) with the detection limit of 5.0 x 10(-8) mol x l(-1). The recovery was 95.2-104.8% with the relative standard deviation of 3.2% (n=10). The pharmaceutical preparations, procaine hydrochloride injection and the urine samples were determined with the desirable results.