Characterization of hsa_circ_0000594 as a new biomarker and therapeutic target for hepatoblastoma.

OBJECTIVE: Various studies have shown that aberrant expression of circular RNAs (circRNAs) has a pivotal role in multifarious cancers. However, the role of circRNAs in hepatoblastoma (HB) is not clearly understood. In the present study, we attempted to explore the underlying mechanism of hsa_cric_0000594 in HB along with its clinical importance. PATIENTS AND METHODS: In our research, the expression pattern of hsa_circ_0000594 in HB tissues and matched normal liver tissues was determined by in situ hybridization and RT-qPCR. Proliferation, viability, migration, and apoptosis of HB cell lines were detected via Cell Counting Kit-8 (CCK-8), colony formation, transwell, and flow cytometry assays. The interaction of hsa_circ_0000594 with miR-217 was investigated by Dual-Luciferase reporter assay. RESULTS: Expression levels of hsa_circ_0000594 were significantly upregulated in HB tissues compared with those in paired normal liver tissues and showed a clear association with the subtype of HB. The knockdown of hsa_circ_0000594 inhibited the malignant phenotype of HB. Bioinformatics analysis suggests that sirtuin 1 (SIRT1) may serve as a target gene of miR-217. CONCLUSIONS: Mechanically, hsa_circ_0000594 was identified to have a critical role in HB development through the hsa_circ_0000594/mir-217/SIRT1 regulatory axis, which might become a novel diagnostic marker and potential therapeutic target in HB.

[Knee stability after anterior cruciate ligament reconstruction with weight-bearing magnetic resonance imaging].

Objective: To investigate the application value of the weight-bearing magnetic resonance imaging (MRI) in evaluating the stability of knee joint after anterior cruciate ligament reconstruction. Methods: From July 2011 to August 2013, a total of 25 patients with anterior cruciate ligament rupture and reconstruction surgery in the Second Affiliated Hospital of Soochow University were enrolled in this study, including 18 males and 7 females, with an average age of (32±5) years. All the patients underwent the weight-bearing MRI, knee joint passive relaxation test (Kneelax 3), and Lysholm score before the surgery and 3 and 6 months after the surgery. The three examinations before and after the operation were analyzed by repeated measures of general linear model, and paired t test was used to compare the results before and after the operation. The correlation between the three preoperative examinations was statistically analyzed. Results: The relaxation data measured by Kneelax 3 after the surgery was significantly lower than that before the operation [(1.1±0.9) mm vs (6.1±1.3) mm, t=16.9, P<0.01]. The post-operative lateral tibial plateau anterior shift score was less than the pre-operative score [(3.0±0.7) mm vs (4.8±1.2) mm, t=6.2, P<0.01]. The post-operative Lysholm score was significantly higher than that before the operation (89±6 vs 64±14, t=-8.3, P<0.05). There was a negative correlation between the anterior displacement of the lateral platform and Lysholm score (r=-0.902, P<0.01). There was no correlation between anterior displacement and passive relaxation of the lateral platform in preoperative weight-bearing MRI. Conclusions: Anterior cruciate ligament reconstruction can improve the knee stability. The stability of knee joint can be evaluated by weight-bearing MRI. The anterior tibial displacement measured by the weight-bearing MRI is correlated with the clinical score.

Effect of hypertonic sodium chloride hydroxyethyl starch 40 on ET, TXB2, 6-keto-PGF1α, and ANP of preeclampsia in caesarean section.

OBJECTIVE: Preeclampsia is a unique disease of pregnancy. Delivery via caesarean section is the most important way of terminating the pregnancy and treating preeclampsia. Perioperative fluid therapy is performed to maintain the circulatory volume and reduce tissue edema. This study evaluated the effects of hypertonic sodium chloride hydroxyethyl starch 40 (HSH40) as perioperative fluid therapy for preeclampsia patients. MATERIALS AND METHODS: Forty preeclamptic women were randomly divided into two groups: the Ringer's solution group and the HSH40 group. Their ECG, HR, MAP, and SPO2 were monitored. Their MVP and HR were recorded at five, eight, and ten minutes after anesthesia induction and at the end of the caesarean section. The corresponding volume of infusion, blood loss, and urine output during the operation were also recorded. Venous samples were collected before HSH40 infusion and 30 min after infusion to measure the plasma concentrations of ET, TXB2, 6-keto-PGF1α, and ANP via a radioimmunoassay. RESULTS: HSH40 infusion significantly decreased the plasma ET levels (p < 0.01), significantly changed the plasma ANP and TXB2 levels (p < 0.05), and significantly increased the plasma 6-keto-PGF1α levels (p < 0.01) in the experimental group compared with those before infusion. The plasma levels of ET, ANP, TXB2, and 6-keto-PGF1α did not significantly change in the control group. Compared with T1, MAP decreased significantly at T2, T3, T4, and T5 within groups (p < 0.05) and between the two groups. MAP significantly changed at T2, T3, T4, and T5 (p < 0.05). HR did not significant change at T1, T2, T3, T4, and T5 within or between groups. Volume of infusion and urine volume significantly differed between groups (p < 0.05). CONCLUSION: Low-dose HSH40 lowers the plasma levels of vasoconstrictor substances (ET and TXB2) and increases the levels of vasodilator substances (6-keto-PGF1α and ANP) during preeclampsia. It effectively maintains and stabilizes the circulating blood volume, increasing renal blood flow, which improves renal function and increases urine output.

Realization of improved efficiency on nanostructured multicrystalline silicon solar cells for mass production.

We report the realization of both excellent optical and electrical properties of nanostructured multicrystalline silicon solar cells by a simple and industrially compatible technique of surface morphology modification. The nanostructures are prepared by Ag-catalyzed chemical etching and subsequent NaOH treatment with controllable geometrical parameters and surface area enhancement ratio. We have examined in detail the influence of different surface area enhancement ratios on reflectance, carrier recombination characteristics and cell performance. By conducting a quantitative analysis of these factors, we have successfully demonstrated a higher-than-traditional output performance of nanostructured multicrystalline silicon solar cells with a low average reflectance of 4.93%, a low effective surface recombination velocity of 6.59 m s(-1), and a certified conversion efficiency of 17.75% on large size (156 × 156 mm(2)) silicon cells, which is ∼0.3% higher than the acid textured counterparts. The present work opens a potential prospect for the mass production of nanostructured solar cells with improved efficiencies.

Characterization and in vitro cellular uptake of PEG coated iron oxide nanoparticles as MRI contrast agent.

Monodisperse magnetic iron oxide nanoparticles (MNPs), coated with PEG at different molecular weight, were prepared via self-assembly method. The particle diameters were measured by dynamic light scattering and transmission electron microscope. Increasing the molecular weight of PEG in the coating polymer increased the overall particles diameter. As coating thickness increased, the saturation magnetization (Ms) and T2 relaxivity decreased. The interactions of these MNPs with macrophage cells were also investigated. The results showed that cellular uptakes of MNPs depended on nanoparticle concentration and surface chemistry. The results of this study will have implications on the chemical design of nanomaterials for bio-imaging and bio-detection.

Development of a sensitive and rapid liquid chromatography/tandem mass spectrometry method for the determination of apomorphine in canine plasma.

A sensitive, rapid and specific quantitative liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed and validated for the determination of apomorphine (APO) in canine plasma. The analytes were prepared using one-step liquid-liquid extraction, and analyzed on a Waters Symmetry C(18) column interfaced with triple quadrupole tandem mass spectrometer. A mixture of methanol/0.1% formic acid in water (70: 30, v/v) was employed as the isocratic mobile phase. Positive electrospray ionization was utilized as the ionization source. The analyte and clenbuterol (internal standard) were both detected using multiple reaction monitoring (MRM) mode. The limit of detection (LOD) obtained was 0.03 ng/mL. The assay was linear over the concentration range of 0.1-100 ng/mL, and provided good precision (RSD) and good accuracy (RE). The analyte was stable by using antioxidants throughout the whole study. The experimental results show that LC/MS/MS is a rapid and sensitive method to analyze APO in plasma. Finally, the proposed method was successfully applied to a pharmacokinetic study of APO after intranasal administration of 0.5 mg apomorphine to 10 healthy beagle dogs.

Transverse evolution of a plasma channel in air induced by a femtosecond laser.

We investigate the evolution of filamentation in air by using a longitudinal diffraction method and a plasma fluorescence imaging technique. The diameter of a single filament in which the intensity is clamped increases as the energy of the pump light pulse increases, until multiple filaments appear.

Pharmacokinetics and bioavailability of sustained release and conventional formulation of acyclovir.

The pharmacokinetics and relative bioavailability of a new sustained release formulation (200mg) of acyclovir (ACV) in comparison with a 100mg reference was investigated. The studies were conducted in two-way crossover design, as single and multiple oral administration in twelve healthy volunteers. Serum samples were assayed for ACV using a high-performance liquid chromatography (HPLC) method with UV detection. The bioavailability of sustained release tablets relative to conventional tablets following single and multiple dosing was 105.9 +/- 12.0% and 95.2 +/- 8.4%, respectively. ANOVA and the two-sided t-test procedures showed significant difference in Cmax and tmax but no difference was found in AUC both in single and multiple dose studies. The results of this study indicated that the new sustained release tablets and the reference are bioequivalent.

Phylogenetic analysis of the S7 gene does not segregate Chinese strains of bluetongue virus into a single topotype.

Bluetongue virus (BTV) infection of ruminants is endemic throughout tropical and subtropical regions of the world. The S7 gene segments of prototype Chinese strains of BTV serotypes 1, 2, 3, 4, 12, 15, and 16 were sequenced and compared to the same genes of prototype strains of BTV from the US, Australia, and South Africa. The S7 genes and predicted VP7 proteins of the Chinese viruses were relatively conserved, with the notable exception of serotype 15. Furthermore, phylogenetic analysis of the S7 genes did not predict geographic origin of the various strains of BTV.

[Preparation of sterically stabilized liposomes containing all-trans retinoic acid].

AIM: To prepare sterically stabilized liposomes containing all-trans retinoic acid, and to study its physicochemical properties. METHODS: The microstructure, the particle size and its distribution was determined by DSC, 1HNMR and 90 Plus Particle Size Analyzer and a TEM photo was taken. RESULTS: The size of conventional liposomes and sterically stabilized liposomes were about 0.35 and 0.42 micron. The sterically stabilized structure can be confirmed by TEM photo. CONCLUSION: The stericallly stabilized liposomes containing all-trans retinoic acid can be prepared by combination of film-casting and freeze-drying.

A novel method to prepare liposomes containing amikacin.

This work describes a novel method to prepare liposomal amikacin composed of soyabean lecithin and cholesterol; these were also prepared using two other methods (cast film method and proliposome method). Encapsulation efficiency was evaluated. Liposomes prepared by the new method, which combines the method of preparing proliposomes with freeze-drying, had the highest encapsulation efficiency. The influence of drug to lipid ratio on the encapsulation efficiency was investigated. The in vitro efflux of amikacin from liposomes with different lecithin: cholesterol ratios was also investigated.

Body distribution in mice of intravenously injected camptothecin solid lipid nanoparticles and targeting effect on brain.

The objective of the present study was to investigate the specific drug targeting of anticarcinogenic drugs, such as camptothecin (CA), after intravenous (i.v.) injection by incorporation into solid lipid nanoparticles (SLN). A CA loaded SLN suspension consisted of 0.1% (w/w) camptothecin, 2.0% (w/w) stearic acid, 1.5% (w/w) soybean lecithin and 0.5% (w/w) polyoxyethylene-polyoxypropylene copolymer (Poloxamer 188) was prepared by high pressure homogenization. In vitro drug release was investigated in pH 7.4 phosphate-buffered saline at 37 degrees C. The concentrations of camptothecin in various organs were determined using reversed-phase high-performance liquid chromatography with a fluorescence detector after i.v. administration of CA-SLN and a camptothecin control solution (CA-Sol). The results showed that the CA-SLN had an average diameter 196.8 nm with a Zeta potential of -69.3 mV and in vitro drug release was achieved for up to a week. In tested organs, the AUC/dose and the mean residence times (MRT) of CA-SLN were much higher than those of CA-Sol, especially in brain, heart and reticuloendothelial cells containing organs. The brain AUC ratio of CA-SLN to CA-Sol was the highest among the tested organs. These results indicate that SLN are a promising sustained release and drug targeting system for lipophilic antitumour drugs, and may also allow a reduction in dosage and a decrease in systemic toxicity.

Studies on drug release kinetics from ibuprofen-carbomer hydrophilic matrix tablets: influence of co-excipients on release rate of the drug.

Controlled-release (CR) matrix tablets of ibuprofen (IBF) and Carbopol(R) 934P, and blended mixture of Carbopol(R) 934P and 971P resins, at different drug to polymers ratios, were prepared by the direct compression method. The investigation focuses on the influence of the proportion of the matrix material, and several co-excipients (lactose, microcrystalline cellulose (MCC), and starch) on the mechanism and release rate of the drug from the tablets. In vitro drug release in pH 7.2 phosphate buffer solution appears to occur both by diffusion and a swelling-controlled mechanism, exhibiting either anomalous or Case II type transport. The release process could be described by plotting the fraction released versus time and fitting data to the simple exponential model: Mt/Minfinity=ktn. The release kinetics were modified when the blended mixtures of Carbopol(R) 934P and 971P resins were used as the matrix materials. In general, all of the co-excipients, used in this study, enhanced the release rate of IBF. However, lactose demonstrated slower and more linear release behavior as compared to microcrystalline cellulose or starch. The dissolution T50 and T90 values for the three co-excipients were in the order of lactose>microcrystalline cellulose>starch.

Ibuprofen release kinetics from controlled-release tablets granulated with aqueous polymeric dispersion of ethylcellulose II: influence of several parameters and coexcipients.

The objective of this study was to investigate the mechanism of ibuprofen (IBF) release from tablets prepared by wet granulation method, using Surelease as a granulating agent. The influence of certain parameters such as the levels of Surelease solids content (SSC), pH of dissolution media, selected dissolution method, and agitation speed on the release profiles of IBF was investigated. The effect of partial replacement of lactose (primary excipient) by various coexcipients such as microcrystalline cellulose, starch, polyvinylpyrrolidone (PVP), sodium alginate, hydroxypropylmethylcellulose (HPMC), and sodium carboxymethyl cellulose (CMC-Na) was also studied. Tablets prepared with surelease as a granulating agent were non-disintegrating and exhibited prolonged release rates as compared to control tablets. The release of IBF from the tablets appears to occur either via water-filled pores or by diffusion through membrane, depending on the levels of SSC. At higher SSC levels pH independent release profiles for IBF were achieved. Dissolution method and agitation speed exhibited no significant effect on the release profiles. All the coexcipients studied enhanced the release rates, irrespective of whether the coexcipients were water-soluble or water-insoluble.

Progesterone receptor immunoreactivity at the maternofetal interface of first trimester pregnancy: a study of the trophoblast population.

The aim of our study was to localize oestrogen receptor (ER) and progesterone receptor (PR) in the trophoblast population at the maternofetal interface in early pregnancy. Rat monoclonal antibodies to human ER and PR were used to study 44 cases of chorionic villi and 82 cases of decidua using an immunocytochemical method. The PR-immunoreactive products were localized in the nuclei of syncytiotrophoblast and cytotrophoblast cells of the villi. Specific staining was also present in the cytoplasm. Villous stroma and vessels were stained occasionally. Using cytokeratin staining in an adjacent section or double staining with PR and cytokeratin, the distribution of invading trophoblast cells and their PR expression were examined. In decidual stroma, a type of interstitial cell was identified which simultaneously expressed cytokeratin and PR in the cytoplasm, indicating that the invading trophoblast cells may express PR. All extravillous populations at the interface were positive for PR, including the syncytial lining of the decidual surface, the cytotrophoblast column, the cytotrophoblast shell and the interstitial trophoblast. The immunoreactivity of PR was also localized in the nuclei of vascular endothelial cells, whereas Factor VIII was localized in the cytoplasm of the same cells, thus confirming their endothelial nature. In contrast to PR, little ER could be detected in the trophoblast cell population using anti-ER antibody D75 in our study.

Immunocytochemical colocalization of progesterone receptor and prolactin in individual stromal cells of human decidua.

Progesterone stimulates decidual PRL production. However, decidualized tissue, in which a high level of PRL is present, features a relatively low level of progesterone receptor (PR) expression. The discrepancy has to be explored at the individual cell level. The present study employed a double labeling method to colocalize PR and PRL in human decidua to examine the correlation between these two proteins. In frozen sections, decidual stroma presented two kinds of cell, which differed in PRL staining. Decidualized cells were positively stained with PRL in cytoplasm and displayed a large cell size and a clear cell outline. Nondecidualized cells showed no specific PRL staining and no clear cell boundary. In decidual stroma, PR staining was exclusively localized in the nuclei, with variations in intensity. When double staining with PR and PRL was performed, these two types of cells demonstrated diverse staining patterns. The PRL-producing cells exhibited weak PR staining, whereas PRL-negative cells evidenced stronger PR staining. In RU 486-treated samples, decidual stroma became less stained with PRL, compared with the control, and fewer cells displayed typical morphology of decidualization, whereas PR staining in the tissue became more extensive and intensive. Double labeling disclosed that the cells with enhanced PR staining were coupled to weaker PRL immunoreaction. Our data suggested an inverse relationship between PRL and PR in individual stromal cells in vivo, which could be reversed by antiprogestin treatment. A possible autocrine mechanism controlling this phenomenon was proposed and deserves further study.

Evidence that the nodulation regulatory gene nodD3 of Rhizobium meliloti is transcribed from two separate promoters.

The Bgl II fragment carried in plasmid pMH903, which covers the nodD3 region of Rhizobium meliloti, has been sequenced. By using both S1 nuclease mapping and primer extension, two transcription start sites were demonstrated in the sequence. After the first transcription start site, there were two open reading frames (ORF) followed by the nodD3 coding sequence which was also preceded by the second promoter. The nodD3 gene under the first promoter mediated high, constitutive expression of nodC-lacZ fusion, and the gene under the second promoter required the product of nodD1 and alfalfa (Medicago sativa) seed exudate for the activation of fusion. Nodulation experiments showed that the nodD3 gene under either promoter was functional in eliciting nodules on alfalfa. The deletion of part of the two ORFs after the first promoter or deletion of the second promoter did not block the constitutive expression of nodC-lacZ fusion, whereas the deletion of the first promoter region or a polar insertion mutation between the two promoters did cause nodD3 to activate nodC only in the presence of the inducer. It indicates that nodD3 can be transcribed from the first promoter as well as from a separate second promoter.

[Pharmacokinetics and pharmacodynamics of diltiazem floating tablets].

Floating tablet is a new type of delayed-action preparations. The present study was aimed at pharmacokinetic and hemodynamic effects of diltiazem floating tablet in 8 healthy volunteers. Each subject received po 90 mg diltiazem floating and normal tablets in a crossover design. For floating tablets the T1/2 (6.4 +/- 4.4 h) and Cmax (56 +/- 23 ng.ml-1) were longer and lower than those of normal tablets (2.3 +/- 1.1 h and 96 +/- 30 ng.ml-1, P < 0.01), respectively. AUC of the 2 forms were similar, suggesting that they had same bioavailability. Diltiazem lowered the blood pressure of the subjects. Although there was no significant difference between the 2 formulations in maximal decreases of systolic and diastolic blood pressures, the duration of hypotension was longer with floating tablets than that with normal ones. There was a positive correlation between diltiazem concentration and its hypotensive action. Thus, administration of floating tablets twice a day may be effective in controlling the blood pressure of hypertensive patients.

[Development of rapid-dissolution armillarisin-A tablet and study on its choleretic action in rats].

For increasing the choleretic action of armillarision-A, a new formulation of rapid-dissolution tablet (A) was developed. The effect of A, a marketed amillarisin-A tablet (B) and a armillarisin-A Na sterile power (C) on rats biliation in vivo were investigated. The dissolution rates of A and B were also determined. The results demonstrate that the choleretic action of A is equal to C but superior to B, and the dissolution rate of A is higher than B. Moreover, the armillarisin-A dissolved percentage of A in vitro at time t was well correlated with the biliation net accumulative amount in vivo at time 3t.

Studies on heterologous expression of Rhizobium meliloti nifA gene and oxygen sensitivity of its product.

When the R. meliloti (Rm) nifA'-lacZ fusion-carrying plasmids were introduced into the strains of Agrobacterium tumefaciens, R. trifolii and R. astragalus, beta-galactosidase activity was demonstrated. However, activity was not induced by microaerobiosis. Furthermore, R. meliloti nifA'-lacZ fusion was also not expressed in the nodule bacteroids of R. trifolii and R. astragalus. We speculate that some factor(s) important for the induction of Rm nifA presumed to be the fixLJ regulatory system would not be operative in these bacteria. Experiments using R. meliloti nifH'-lacZ/K. Pneumoniae nifH'-lacZ fusion and the constitutive Rm nifA system to test the nifA-dependent expression of nifH'-lacZ under aerobic and microaerobic conditions in E. coli were performed. The inhibition of the Rm nifA activation of nifH'-lacZ expression in the bacteria grown in the aerobic condition was shown. Assays on the Rm nifA-m RNA produced by the constitutive Rm nifA in E. coli under aerobic and microaerobic conditions with the cloned nifA as a probe for dot blot hybridization showed a marked decrease of Rm nifA mRNA when the bacteria were grown under aeration.