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Yuzhu Hu

Publications and source records attributed to Yuzhu Hu.

11 recordsLinked to original sources
PubMed2025

Genome-wide DNA methylation and transcriptome sequencing analyses of lens tissue in an age-related mouse cataract model.

DNA methylation is known to be associated with cataracts. In this study, we used a mouse model and performed DNA methylation and transcriptome sequencing analyses to find epigenetic indicators for age-related cataracts (ARC). Anterior lens capsule membrane tissues from young and aged mice were analyzed by MethylRAD-seq to detect the genome-wide methylation of extracted DNA. The young and aged mice had 76,524 and 15,608 differentially methylated CCGG and CCWGG sites, respectively. The Pearson correlation analysis detected 109 and 33 differentially expressed genes (DEGs) with negative methylation at CCGG and CCWGG sites, respectively, in their promoter regions. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analyses showed that DEGs with abnormal methylation at CCGG sites were primarily associated with protein kinase C signaling (Akap12, Capzb), protein threonine kinase activity (Dmpk, Mapkapk3), and calcium signaling pathway (Slc25a4, Cacna1f), whereas DEGs with abnormal methylation at CCWGG sites were associated with ribosomal protein S6 kinase activity (Rps6ka3). These genes were validated by pyrosequencing methylation analysis. The results showed that the ARC group (aged mice) had lower Dmpk and Slc25a4 methylation levels and a higher Rps6ka3 methylation than the control group (young mice), which is consistent with the results of the joint analysis of differentially methylated and differentially expressed genes. In conclusion, we confirmed the genome-wide DNA methylation pattern and gene expression profile of ARC based on the mouse cataract model with aged mice. The identified methylation molecular markers have great potential for application in the future diagnosis and treatment of ARC.

Animals↗
PubMed2006

Single-based resolution for oligodeoxynucleotides and their phosphorothioate modifications by replaceable capillary gel electrophoresis.

A replaceable capillary gel electrophoretic (replaceable CGE) method was developed for the separation of two sets of model compounds of single-stranded oligodeoxynucleotide mixtures (18-20 mers), phosphodiester oligodeoxynucleotides (PO-ODNs) and their phosphorothioate modifications (PS-ODNs), with equal sequences differing in a single base. Polyethylene glycol (PEG) 35000 was chosen as the sieving matrix. It was confirmed that PEG polymer solution less influenced resolutions of the PS-ODNs compared with those of the PO-ODNs, while acetonitrile used as an additive in the system improved the separation significantly. It was also noticed that the effect of temperature on separation was much larger than that of denaturant urea.

Acetonitriles↗
PubMed2006

[Study of blending method for the extracts of herbal plants].

The irregularity in herbal plant composition is influenced by multiple factors. As for quality control of traditional Chinese medicine, the most critical challenge is to ensure the dosage content uniformity. This content uniformity can be improved by blending different batches of the extracts of herbal plants. Nonlinear least-squares regression was used to calculate the blending coefficient, which means no great absolute differences allowed for all ingredients. For traditional Chinese medicines, even relatively smaller differences could present to be very important for all the ingredients. The auto-scaling pretreatment was used prior to the calculation of the blending coefficients. The pretreatment buffered the characteristics of individual data for the ingredients in different batches, so an improved auto-scaling pretreatment method was proposed. With the improved auto-scaling pretreatment, the relative. differences decreased after blending different batches of extracts of herbal plants according to the reference samples. And the content uniformity control of the specific ingredients could be achieved by the error control coefficient. In the studies for the extracts of fructus gardeniae, the relative differences of all the ingredients is less than 3% after blending different batches of the extracts. The results showed that nonlinear least-squares regression can be used to calculate the blending coefficient of the herbal plant extracts.

Drugs, Chinese Herbal↗
PubMed2005

[Similarity system theory to evaluate similarity of chromatographic fingerprints of traditional Chinese medicine].

The similarity evaluation of the fingerprints is one of the most important problems in the quality control of the traditional Chinese medicine (TCM). Similarity measures used to evaluate the similarity of the common peaks in the chromatogram of TCM have been discussed. Comparative studies were carried out among correlation coefficient, cosine of the angle and an improved extent similarity method using simulated data and experimental data. Correlation coefficient and cosine of the angle are not sensitive to the differences of the data set. They are still not sensitive to the differences of the data even after normalization. According to the similarity system theory, an improved extent similarity method was proposed. The improved extent similarity is more sensitive to the differences of the data sets than correlation coefficient and cosine of the angle. And the character of the data sets needs not to be changed compared with log-transformation. The improved extent similarity can be used to evaluate the similarity of the chromatographic fingerprints of TCM.

Chemical Fractionation↗
PubMed2004

HPLC determination of sertraline in bulk drug, tablets and capsules using hydroxypropyl-beta-cyclodextrin as mobile phase additive.

A sensitive and stereospecific high-performance liquid chromatography (HPLC) method for determination of sertraline in bulk drug, tablets and capsules was developed. Chromatography resolution of the sertraline enantiomeric forms and trans diastereoisomers was performed on Alltima C18 (250 mm x 4.6mm i.d., 5 microm) column with hydroxypropyl-beta-cyclodextrin (HP-beta-CD) as mobile phase additive. The composition of the mobile phase was 68:32 (v/v) aqueous 170 mM phosphate buffer, pH 3.0 (adjusted with 85% phosphoric acid) containing 18 mM HP-beta-CD/acetonitrile at a flow rate of 1.0 ml x min(-1). The UV detector was set at 225 nm. Calibration curves were linear (r=0.9999, n=9) in the range of 1-120 microgml (-1) for sertraline. Limit of detection and quantitation for sertraline was 0.029 and 0.097 microg x ml (-1). The values of R.S.D. of repeatability and intermediate precision for bulk drug, tablets and capsules of sertraline hydrochloride were less than 1.0%.

2-Hydroxypropyl-beta-cyclodextrin↗
PubMed2004

[Study on chiral selective inclusion and retention characteristics of cis-trans isomers and enantiomers of sertraline with HP-beta-CD as a mobile phase modifier].

The effect of the inclusion complex formation of cis-trans isomers and enantiomers of sertraline with added hydroxypropyl-beta-cyclodextrin (HP-beta-CD) in the reversed-phase high performance liquid chromatographic (RP-HPLC) mobile phase on the retention and selectivity has been investigated. Graphs of 1/k vs [HP-beta-CD] in different experimental conditions gave good linear relationships, indicating the stoichiometry ratio of 1:1. The binding constants between HP-beta-CD and cis-trans isomers and enantiomers of sertraline were calculated by using the liquid chromatographic retention values. Meanwhile, the influences of pH value, buffer ionic strength, concentration of organic modifier and temperature on the binding constant have been studied in detail. Quantitative equations were obtained for the correlations between the binding constants and the above influencing parameters. On the other hand, the thermodynamic parameters of the inclusion complexes were determined for the four inclusion complexes. The study characterized the chiral recognition selectivity between sertraline isomers and HP-beta-CD. It was demonstrated that the chiral selectivity values were in the same sequence as delta(j,i) deltaH and delta(j,i) deltaS and opposite order against the binding constants of inclusion complexes. Both enthalpic and entropic terms were negative for cis-trans isomers and enantiomers of sertraline. It was confirmed that enthalpy-driven separations occurred in consistency with the results. The influence of temperature on retention behavior showed that the process of inclusion was exothermic, in consistency with the calculated thermodynamic parameters.

2-Hydroxypropyl-beta-cyclodextrin↗
PubMed2003

Determination of cetylpyridinium chloride and tetracaine hydrochloride in buccal tablets by RP-HPLC.

The HPLC method for simultaneous determination of cetylpyridinium chloride (CPC), tetracaine hydrochloride (TTC) in Xipiluan buccal tablets was developed and validated. The HPLC method was performed on a CN column (150 x 4.6 mm i.d., 5 microm particle size); the mobile phase was methanol-tetramethylammonium hydroxide (20 mM)-potassium dihydrogen phosphate (3 mM) (90:10:3, v/v/v) (pH* 5.0), pumped at a flow rate 1.5 ml min(-1). The UV detector was set at 230 nm. The retention time for CPC and TTC was 3.52 and 3.10 min, respectively. Calibration curves were linear (r=0.9999, n=6) in the range of 5-2000 microg ml(-1) for CPC and 1-500 microg ml(-1) for TTC. Limit of detection and quantitation for CPC was 0.033 and 0.11 microg ml(-1), for TTC were 0.0056 and 0.019 microg ml(-1). The R.S.D. of repeatability and intermediate precision for CPC and TTC were less than 2.0%.

Administration, Buccal↗
PubMed2002

Determination of laser-induced thymine-thymine dimer in DNA by LC.

A new simple and selective high-performance liquid chromatography (HPLC) method has been developed for the determination of thymine-thymine (T-T) dimer in deoxyribonucleic acid (DNA) for the study of relationship between the yield of T-T dimer and laser irradiation conditions. The HPLC method is not disturbed by other hydrolysate formed in DNA with the good stability and reproducility. The detection of limit of the method is about 8.8 ng of T-T dimer in DNA blank. Three lever of laser intensity to irradiate DNA were selected for calf thymine to test the influence of the pulse number. The mechanism of DNA lesion and repair caused by laser irradiating was studied.

Animals↗
PubMedDate not supplied

A new method to evaluate the similarity of chromatographic fingerprints: weighted pearson product-moment correlation coefficient.

The Pearson product-moment correlation coefficient is being used to evaluate the similarity of the high-performance liquid chromatographic fingerprints of traditional Chinese medicine (TCM) in China. It is confirmed that a large range of peak areas produced the wrong results. A new algorithm concerning weighted Pearson product-moment correlation coefficient is proposed in this article. The results for both real cases and simulated data sets show that the weighted Pearson product-moment correlation coefficients allow relatively larger differences for large values, smaller differences for small values, and more reliable results than the unweighted Pearson product-moment correlation coefficients. Weight selection depends on the specific scientific problem.

Journal Article↗
PubMedDate not supplied

Determination of amantadine sulfate in sodium chloride injection by capillary gas chromatography.

This paper describes a new method to determine amantadine sulfate in sodium chloride injection by capillary gas chromatography. The chromatographic conditions of the methods employed a SGE BP-1 capillary column (30 m x 0.53 mm i.d., 1.0-microm film thickness); isothermal elution with N2 at a pressure of 100 KPa; injector, oven, and detector temperatures at 220 degrees C, 110 degrees C, and 220 degrees C, respectively; a split-less mode; and a 1-microL injection volume. Naphthalene was used as the internal standard. Peak purity testing with a Varian Saturn 2200 capillary gas chromatography- mass spectrometry system (Varian, Inc.) equipped with a DB-5 capillary column (30 m x 0.25 mm i.d., 0.25-microm film thickness) was performed for the investigation of specificity. There was a linear relationship between peak area ratios of analyte to the internal standard and concentration of analyte over the concentration range 0.1-2.0 mg/mL. The recovery was 97.8 approximately 100.7%. The relative standard deviation (%) of intermediate precision was less than 0.8. The limits of detection and quantitation were 0.2 microg/mL with a signal-to-noise ratio of 3, and 0.7 microg/mL with a signal-to-noise ratio of 10, respectively. The results of determination were similar to the titration method.

Amantadine↗