Hepatocellular carcinoma: An analysis of the expression status of stress granules and their prognostic value.

BACKGROUND: Hepatocellular carcinoma (HCC) is a global popular malignant tumor, which is difficult to cure, and the current treatment is limited. AIM: To analyze the impacts of stress granule (SG) genes on overall survival (OS), survival time, and prognosis in HCC. METHODS: The combined The Cancer Genome Atlas-Liver Hepatocellular Carcinoma (TCGA-LIHC), GSE25097, and GSE36376 datasets were utilized to obtain genetic and clinical information. Optimal hub gene numbers and corresponding coefficients were determined using the Least absolute shrinkage and selection operator model approach, and genes for constructing risk scores and corresponding correlation coefficients were calculated according to multivariate Cox regression, respectively. The prognostic model's receiver operating characteristic (ROC) curve was produced and plotted utilizing the time ROC software package. Nomogram models were constructed to predict the outcomes at 1, 3, and 5-year OS prognostications with good prediction accuracy. RESULTS: We identified seven SG genes (DDX1, DKC1, BICC1, HNRNPUL1, CNOT6, DYRK3, CCDC124) having a prognostic significance and developed a risk score model. The findings of Kaplan-Meier analysis indicated that the group with a high risk exhibited significantly reduced OS in comparison with those of the low-risk group (P < 0.001). The nomogram model's findings indicate a significant enhancement in the accuracy of OS prediction for individuals with HCC in the TCGA-HCC cohort. Gene Ontology and Gene Set Enrichment Analysis suggested that these SGs might be involved in the cell cycle, RNA editing, and other biological processes. CONCLUSION: Based on the impact of SG genes on HCC prognosis, in the future, it will be used as a biomarker as well as a unique therapeutic target for the identification and treatment of HCC.

Supramolecular interaction of methotrexate with cucurbit[7]uril and analytical application.

The supramolecular interaction between cucurbit[7]uril (CB[7]) as the host and the anti-cancer drug methotrexate (MTX) as the guest was studied using fluorescence spectroscopy, UV-visible absorption spectroscopy, 1H NMR, 2D NOESY, and theoretical calculations. The experimental results confirmed the formation of 1:2 inclusion complex with CB[7] and indicated a simple and sensitive competitive method for the fluorescence detection of MTX. It was found that the fluorescence intensities of CB[7]-palmatine, CB[7]-berberine and CB[7]-coptisine were quenched linearly upon the addition of MTX. The linear ranges obtained in the detection of MTX were 0.1-15µgmL-1, 0.2-15µgmL-1, and 0.4-15µgmL-1 with detection limits of 0.03µgmL-1, 0.06µgmL-1, and 0.13µgmL-1, respectively. This method can be used for the determination of MTX in biological fluids. These results suggested that cucurbit[7]uril is a promising drug carrier for targeted MTX delivery and monitoring, with improved efficacy and reduced toxicity in normal tissues.

Determination of phenformin hydrochloride employing a sensitive fluorescent probe.

A complexation of non-fluorescent phenformin hydrochloride (PFH) with cucurbit [7]uril (CB [7]) in aqueous solution was investigated using the fluorescent probe of palmatine (PAL) coupled with CB [7]. The fluorescent probe of CB [7]-PAL exhibited strong fluorescence in aqueous solution, which was quenched gradually with the increase of PFH. This effect is observed because when PFH was added to the host-guest system of CB [7]-PAL, PFH and PAL competed to occupy the CB [7] cavity. Portions of the PAL molecule were expelled from the CB [7] cavity owing to the introduction of PFH. Based on the significant quenching of the supramolecular complex fluorescence intensity, a fluorescence method of high sensitivity and selectivity was developed to determine PFH with good precision and accuracy for the first time. The linear range of the method was 0.005-1.9 µg mL(-1) with a detection limit of 0.003 µg mL(-1). In this work, association constants (K) of PFH with CB [7] were also determined. KCB [7]-PFH=(2.52±0.05)×10(5) L mol(-1). The ability of PFH to bind with CB [7] is stronger than that of PAL. The results of a density functional theory calculation authenticated that the moiety of PFH was embedded in the hydrophobic cavity of CB [7] tightly, and the nitrogen atom is located in the vicinity of a carbonyl-laced portal in the energy-minimized structure. The molecular modelling of the interaction between PFH and CB [7] was also confirmed by (1)H NMR spectra (Bruker 600 MHz).

A competitive strategy based on cucurbit[7]uril supramolecular interaction for simple and sensitive detection of dibucaine.

In this work, the competitive interaction between dibucaine and three fluorescent probes (i.e., berberine, palmatine, and coptisine) for occupancy of the cucurbit[7]uril (CB[7]) cavity was studied by fluorescence spectra, UV-visible absorption spectra, (1)H NMR spectra, and theoretical calculations in acidic aqueous solution. Based on the fluorescence enhancement of berberine, palmatine, and coptisine upon binding with CB[7], respectively, a series of fluorescence detection methods for dibucaine were proposed. At the optimized conditions, the fluorescence intensity of berberine-CB[7], palmatine-CB[7], and coptisine-CB[7] complexes showed negative correlation to the concentration of dibucaine, which led to a series of simple and sensitive fluorescence methods for the determination of dibucaine for the first time. Linear ranges obtained in the detection of the dibucaine were 0.018-3.34 µmol L(-1), 0.032-4.47 µmol L(-1), and 0.079-4.42 µmol L(-1) with detection limits of 6.0 nmol L(-1), 12.0 nmol L(-1), and 25.0 nmol L(-1), respectively. Moreover, the proposed method was successfully applied for the determination of the drug in biological fluids. The competitive mode based on CB[7] superstructure provided a promising assay strategy for fluorescence detection in various potential applications.

Anionic surfactant micelle-mediated extraction coupled with dispersive magnetic microextraction for the determination of phthalate esters.

A novel and easy two-step microextraction technique combining anionic surfactant coacervation phase (CAP) extraction and dispersive microsolid-phase extraction (D-µ-SPE) was developed for the high-performance liquid chromatography-ultraviolet detection to determination of phthalate esters (PEs) in water samples. The method started with the phase separation of sodium dodecylbenzenesulfonic acid (SDBSA) obtained by adding NaCl, whereas the target analytes were extracted in the CAP. The CAP was then retrieved using diatomaceous earth-supported magnetite nanoparticles. The effects of solution acidity, SDBSA, and electrolyte concentration, extraction time, magnetic material quantity, and elution solvent volume were discussed. Under optimal extraction conditions, the extraction recoveries ranged from 48.6 to 84.8%, and relative standard deviations ranged from 3.9 to 5.7% (n = 10). The detection limits ranged from 0.5 to 5.0 ng mL(-1) for the five PEs. The proposed method was used to determine the five PEs in the water samples and recoveries between 85.7 and 105.5%.

Supramolecular interaction of two tryptophans with p-sulfonated calix[4,6,8]arene.

The complex characteristics of p-sulfonated calix[n]arene (SCnA) and two tryptophans N-[(tert-butoxy) carbonyl]-tryptophan (trp-A) and N-carbobenzoxy-tryptophane (trp-B) were examined through various techniques. Spectrofluorimetry was performed at different temperatures to determine the stability constants and evaluate the thermodynamic parameters of the two complexes. The effect of pH on complex formation was estimated. According to the fluorescence data, the assumption about the steric hindrance of the tert-butyl group of trp-A and the phenyl group of trp-B was put forward. (1)H NMR was also performed to determine the binding interaction mechanism. Results showed that the indole benzene rings of the two tryptophans partly penetrated into the cavity of p-sulfonated calix[n]arene. The shift in Ha, Hb and Hc, Hd positions became more significant as the number of phenolic units of the calixarene ring increased. Molecular modeling of the complexes elucidated the assumption about the steric hindrance of the tert-butyl group of trp-A and the phenyl group of trp-B. These observations of molecular modeling computation are consistent with previous fluorescence data and (1)H NMR results.

A rapid shaking-based ionic liquid dispersive liquid phase microextraction for the simultaneous determination of six synthetic food colourants in soft drinks, sugar- and gelatin-based confectionery by high-performance liquid chromatography.

A novel and simple rapid shaking-based method of ionic liquid dispersive liquid phase microextraction for the determination of six synthetic food colourants (Tartrazine, Amaranth, Sunset Yellow, Allura Red, Ponceau 4R, and Erythrosine) in soft drinks, sugar- and gelatin-based confectionery was established. High-performance liquid chromatography coupled with an ultraviolet detector was used for the determinations. The extraction procedure did not require a dispersive solvent, heat, ultrasonication, or additional chemical reagents. 1-Octyl-3-methylimidazolium tetrafluoroborate ([C8MIM][BF4]) was dispersed in an aqueous sample solution as fine droplets by manual shaking, enabling the easier migration of analytes into the ionic liquid phase. Factors such as the [C8MIM][BF4] volume, sample pH, extraction time, and centrifugation time were investigated. Under the optimum experimental conditions, the proposed method showed excellent detection sensitivity with limits of detection (signal-to-noise ratio=3) within 0.015-0.32 ng/mL. The method was also successfully used in analysing real food samples. Good spiked recoveries from 95.8%-104.5% were obtained.

Determination of amantadine and rimantadine using a sensitive fluorescent probe.

Amantadine hydrochloride (AMA) and rimantadine hydrochloride (RIM) are non-fluorescent in aqueous solutions. This property makes their determination through direct fluorescent method difficult. The competing reactions and the supramolecular interaction mechanisms between the two drugs and coptisine (COP) as they fight for occupancy of the cucurbit[7]uril (CB[7]) cavity, were studied using spectrofluorimetry, (1)H NMR, and molecular modeling calculations. Based on the significant quenching of the supramolecular complex fluorescence intensity, a fluorescent probe method of high sensitivity and selectivity was developed to determine AMA or RIM in their pharmaceutical dosage forms and in urine samples with good precision and accuracy. The linear range of the method was from 0.0040 to 1.0 µg mL(-1) with a detection limit ranging from 0.0012 to 0.0013 µg mL(-1). This shows that the proposed method has promising potential for therapeutic monitoring and pharmacokinetics and for clinical application.

Determination of ranitidine, nizatidine, and cimetidine by a sensitive fluorescent probe.

A validated, simple, and sensitive fluorescence quenching method for the determination of ranitidine, nizatidine, and cimetidine in tablets and biological fluids is presented. This is the first single fluorescence method reported for the analysis of all three H(2) antagonists. The competitive reaction between the investigated drug and the palmatine probe for the occupancy of the cucurbit[7]uril (CB[7]) cavity was studied using spectrofluorometry. CB[7] was found to react with the probe to form a stable complex. The fluorescence intensity of the complex was also enhanced greatly. However, the addition of the drug dramatically quenched the fluorescence intensity of the complex. Accordingly, a new fluorescence quenching method for the determination of the studied drugs was established. The different experimental parameters affecting the fluorescence quenching intensity were studied carefully. At optimum reaction conditions, the rectilinear calibration graphs between the fluorescence quenching values (ΔF) and the medicament concentration were obtained in the concentration range of 0.04-1.9 µg mL(-1) for the investigated drugs. The limits of detection ranged from 0.013 to 0.030 µg mL(-1) at 495 nm using an excitation wavelength of 343 nm. The proposed method can be used for the determination of the three H(2) antagonists in raw materials, dosage forms and biological fluids.

Ionic liquid sensitized fluorescence determination of four isoquinoline alkaloids.

The fluorescence spectra of berberine, palmatine, jatrorrhizine, and coptisine in ionic liquids were studied and found to increase significantly in ionic liquids, with [C(8)MIM][PF(6)] having the greatest increase. Further studies showed that these drugs could be extracted from an aqueous solution by [C(8)MIM][PF(6)] using the temperature-assisted ionic liquid dispersive liquid phase microextraction method. The enrichment factors were 81.8-82.3, and the extraction recovery was 98.5%, 98.1%, 98.3%, and 98.8% for berberine, palmatine, jatrorrhizine, and coptisine, respectively. Based on the [C(8)MIM][PF(6)] preconcentration, separation, and sensitized fluorescence for these drugs, a new selective and sensitive method for the determination of concentration of these four drugs in aqueous samples was presented. At optimum conditions, the linear relationship was obtained in the ranges of 0.8-130 ng mL(-1), 0.9-160 ng mL(-1), 0.7-140 ng mL(-1), and 0.6-110 ng mL(-1), respectively. The proposed method was successfully applied for the determination of the drugs in pharmaceutical preparations, urine, and plasma samples.

Determination of ethambutol by a sensitive fluorescent probe.

The competitive reaction between ethambutol and two fluorescent probes (i.e., berberine and palmatine) for occupancy of the cucurbit[7]uril (CB[7]) cavity was studied by spectrofluorometry. The CB[7] reacts with these probes to form stable complexes, and the fluorescence intensity of the complexes is greatly enhanced. In addition, the excitation and emission wavelengths of their complexes moved to wavelengths of 343 nm and 495 nm, respectively. However, the addition of ethambutol dramatically quenches the fluorescence intensity of the two complexes. Accordingly, a couple of new fluorescence quenching methods for the determination of ethambutol were established. The methods can be applied for quantifying ethambutol. A linear relationship between the fluorescence quenching values (ΔF) and ethambutol concentration exists in the range of 5.0-1000.0 ng mL(-1), with a correlation coefficient (r) of 0.9997. The detection limit is 1.7 ng mL(-1). The fluorescent probe of berberine has higher sensitivity than palmatine. This paper also discusses the mechanism of fluorescence indicator probes.

Determination of ofloxacin and gatifloxacin by mixed micelle-mediated cloud point extraction-fluorimetry combined methodology.

A cloud point extraction process using mixed micelle of the anionic surfactant sodium dodecyl sulfate (SDS) and the non-ionic surfactant polyoxyethylene(7.5)nonylphenylether (PONPE 7.5) to extract two fluoroquinolone antimicrobial agents, ofloxacin and gatifloxacin, from aqueous media was investigated. The method is based on the mixed micelle-mediated extraction of fluoroquinolones in the presence of NaCl as an inducing agent in phase separation, followed by spectrofluorimetric determination. The effect of different variables such as pH, PONPE7.5 concentration, SDS concentration, NaCl concentration, cloud point temperature, and time was investigated, and optimum conditions were established. At optimum conditions, the rectilinear calibration graphs were obtained in the concentration range of 0.1-150 and 0.1-250ngmL(-1) for ofloxacin and gatifloxacin, and the limits of detection were 0.04 and 0.06ngmL(-1), respectively. The proposed procedure was applied successfully for the detection of the investigated drugs in their pharmaceutical dosage forms, in spiked plasma, spiked urine, and urine samples, with good precision and accuracy.

Supramolecular interaction of cucurbit[n]urils and coptisine by spectrofluorimetry and its analytical application.

The supramolecular interaction of a homologous series of cucurbit[n]uril (CB[n], n=5, 6, 7, 8) hosts and coptisine (COP) was studied by spectrofluorimetry. All of the CB[n]s were found to react with COP to form 1:1 host-guest stable complexes and the fluorescence intensity of the complexes was greatly enhanced. The apparent association constants of the complexes were 1.44 x 10(4), 1.28 x 10(4), 1.86 x 10(4) and 1.26 x 10(4)L mol(-1) for CB[5], CB[6], CB[7] and CB[8], respectively. In addition, CB[5] and CB[7] exhibited a higher fluorescence signal than CB[6] and CB[8]. The fluorescence intensity of the complex with CB[7] was enhanced 70-fold compared to that of the studied drug itself. Based on the significant enhancement of fluorescence intensity of supramolecular complex, a simple, rapid, highly sensitive, and selective spectrofluorimetric method was developed for the determination of COP in aqueous solution in the presence of CB[7]. At the optimum reaction conditions, a linear relationship was obtained in the range from 0.05 to 1700 ng mL(-1) with a detection limit of 0.012 ng mL(-1). The proposed method was successfully applied for the determination of the drug in urine and serum samples.

Study on the inclusion interaction of cucurbit[n]urils with sanguinarine by spectrofluorimetry and its analytical application.

The characteristics of host-guest complexation between cucurbit[n]uril (CB[n], n=5, 6, 7, 8) and sanguinarine (SA) were investigated by spectrofluorimetry. The result showed that CB[n] (n=5, 6, 7, 8) reacted with SA to form an inclusion complex. At the optimum reaction conditions, the rectilinear calibration graphs were obtained in the range from 0.1 to 2800 ng mL(-1) for the investigated drug, with correlation coefficients 0.9998, 0.9997, 0.9999 and 0.9997 and detection limits 0.052, 0.26, 0.03 and 0.058 ng mL(-1) using CB[5], CB[6], CB[7], and CB[8], respectively. The apparent association constants of the complexes were 1.23 x 10(4), 6.73 x 10(3), 4.53 x 10(4) and 1.21 x 10(4) L mol(-1), for the reagents in the same order. The result demonstrated that CB[7] exhibited a higher fluorescence signal than CB[5], CB[6], and CB[8]. The proposed method was successfully applied for the determination of the drug in human urine and serum samples.

[Artificial neural networks for the identification of infrared spectra of Ilex Kudingcha].

In order to identify Ilex Kudingcha, two kinds of models of artificial neural networks (ANN), i.e. competitive neural network and back propagation neural network, were used to analyze their infrared spectra. Ilex Kudingcha samples were collected by Fourier transform infrared (FTIR) spectra. Twenty five samples were gathered as a train set, and 11 samples as a test set, then their training was performed using two networks each. The results show that the identification of Ilex Kudingcha from different areas can be effectively performed with the competitive neural network and BP network, but the competitive neural network is used in the identification of different grades of Ilex Kudingcha. The results were better in training speed and accuracy with the competitive neural network. In conclusion, the competitive neural network combined with FTIR spectroscopy is a good method for the identification of Ilex Kudingcha.

[Spectroscopic study on binding of indomethacin to bovine serum albumin].

The interaction between indomethacin (IM) and bovine serum albumin (BSA) under physiological condition was studied using fluorescence and absorption spectra. It was proved that fluorescence quenching of BSA by IM is deduced by combining static quenching with nonradiative energy transfer. The binding constants were obtained by fluorescence quenching method. The main sorts of binding force were determined according to the thermodynamic parameters. The binding distances and energy transfer efficiencies between indomethacin and bovine serum albumin were obtained based on the theory of Forster nonradiative energy transfer. Combining the results of UV absorption and fluorescence spectroscopic methods, the binding mode of IM with BSA was discussed.

[Common and variant peak ratios in IR fingerprint of ilex kudingcha with duel-index sequence analysis].

In the present article, two new indexes, common peak ratio and variant peak ratio, were applied and their values were calculated by means of sequential analysis, in which each Ilex Kudingcha sample s IR fingerprint spectra were set up and the common peak ratio sequences were arranged in order of size in comparision with other samples. As a result, the method could be used to distinguish Ilex Kudingcha of different areas and classes. The duel-index sequential analysis enables us to distinct two or more herb's IR fingerprints. It is a new method to analyze IR fingerprint spectra, and can used in line with the characteristics of traditional Chinese medicine.

[Spectrophotometric determination of codeine through charge-transfer reaction].

The charge-transfer reaction of 7,7,8,8-tetracyano-quinodimethane (TCNQ) as a pi-electron acceptor with codeine as electron donors was investigated by spectrophotometry. TCNQ was found to react with codeine to produce stable charge-transfer complexes in acetone. Meanwhile, the studied drugs suffer a considerable bathochromic shift (from 216 to 843 nm). The influential factor of charge-transfer reaction and the optimum conditions for the determination of codeine were investigated in detail. Therefore a simple, rapid and accurate method with a good selectivity for the determination of codeine has been developed. The results show that Beer's law is obeyed in the ranges 0.1-1.6 microg x mL(-1) for codeine. The apparent molar absorptivity of the complex at 843 nm is 1.7 x 10(4) L x mol(-1) x cm(-1). Furthermore, the association constants and standard free energy changes were studied, and the mechanism of charge-transfer reaction was explored elementarily. The proposed method has been applied successfully to the determination of codeine in pharmaceutical preparations. The recoveries are from (98.94+/-0.96)% to (99.12+/-1.21)%.

Spectrophotometric determination of anilines based on charge-transfer reaction.

The molecular interactions between aniline, p-toluidines, benzidine and p-phenylenediamine as electron donors and 7,7,8,8-tetracyanoquinodimethane (TCNQ) as acceptor have been investigated by spectrophotometric method. Different variables affecting the reaction were studies and optimized. At the optimum reaction conditions Beer's law was obeyed in a concentration limit of 0.6-3.0, 0.3-3.0, 0.3-3.0 and 0.3-2.7 microg ml(-1) for aniline, p-toluidines, benzidine and p-phenylenediamine. The developed methods were applied successfully for the determination of the studied compounds in waste water and relative standard deviation of the methods were 0.8-3.0%. Percentage recoveries ranged from 97.22% to 102.78%.

[Ultraviolet spectral characteristics of charge-transfer reaction complex in micellar system and its application].

Charge-transfer (CT) reaction of chloranil (TCBQ) as a pi-electron acceptor with fleroxacin (FLX) as an electron donor has been studied by ultraviolet spectrophotometry method. Experiment showed that FLX reacted with TCBQ in sodium dodecyl sulfate (SDS) micellar systems, and a stable complex was formed and the absorbency was remarkably enhanced. Therefore, a simple, rapid, accurate and sensitive method for the determination of FLX has been developed. Beer's law is obeyed in the range of 0.6-24 mg x L(-1) of FLX and r = 0.9993. The apparent molar absorptivity of CT complexes at 326 nm is 3.3 x 10(4) L x mol(-1) x cm(-1). The composition of CT complex was found to be 1:1 by Bent-French and curved intersection methods. The proposed method has been applied to the determination of ESL in tablets. The recoveries are 99.2%-99.7%. The relative standard deviation is 0.7%-2.1%. The proposed methods are suitable for the routine quality control of drug alone and in tablets or capsules without fear of interference caused by the excipients expected to be present in tablets or capsules.