Ji Chenfeng

Studies on Toxic Action on Immune System and Machanism of Toluene Diisocyanate

This studies are carried on toxic action and machanism of toluene diisocyanate on immune system. With HE pigmentation and terminal deoxynucleotide transferase- mediated dUTP nick end labeling (TUNEL), effect on Eosinophilia numbers and eosinophil apoptosis of toluene diisocyanate in mice is observed. It is still observed that effect of toluene diisocyanate on conglutinate molecule and IL-4, IL-5, GM-CSF by ELASA. Studies could make sure the safe dose or allowable dose of Toluene diisocyanateis. It will provide the solid science theories basis for executing environmental law, confirming prevention and cure counterplan, evaluating its health risk and ecosystem risk.

Determination and Analysis of Toluene Diisocyanate Metabolites in Mice

This paper is to to determine metabolites of toluene diisocyanate (TDI) in mice and deduced the pathway for toluene diisocyanate metabolism in the organism. Toluene diisocyanate was administered to mice for 2 weeks, samples of blood, feces, and urine were taken, and the structure of the toluene diisocyanate metabolites was determined using gas chromatography-mass spectrometry (GC-MS). Conditions for TDI chromatography: Supelco PTETM-5 chromatographic column (30 mm times 0.25 mm times 0.25 mum); initial column temperature: 90degC, which was maintained for 30 min, after which the temperature was increased at a rate of 40degC/min to 280degC, which temperature was then maintained for 5.25 min; temperature for the vaporizing chamber: 250degC; carrier gas: helium flowing at 1.0 mL/min. Conditions for chromatography of TDI metabolites in the organism: 94% methyl, 4% ethenyl-bonded-phase fused-silica capillary column (30 + 2 mX 0.25 + 0.02 mm); initial column temperature: 30degC, which was maintained for 5 min, after which the temperature was increased at a rate of 80degC/min to 280degC, which temperature was then maintained for 5 min; temperature for the vaporizing chamber: 250degC; carrier gas: helium flowing at 1.0 mL/min. Conditions for mass spectrometry: EI for ionization; 70 eV for ionization energy; 280degC for connecting tube temperature; 35-350 amu for range of scanning; and 1.0 muL for sample size. The results showed 2,4-toluene diisocyanate was metabolized into 2,4-diaminotoluene, which is completely the same in male and female animals. Under the conditions selected for GC-MS, TDI metabolites in the organism can be isolated. Endogenous impurities in the blood, feces, or urine of mice do not interfere with the measurements.

Species classification and bioactive ingredients accumulation of BaiJiangCao based on characteristic inorganic elements analysis by inductively coupled plasma-mass spectrometry and multivariate analysis

Background: Patrinia scabiosaefolia Fisch and Patrinia villosa (Thunb.) Juss., two species herbs with the same Chinese name “BaiJiangCao”, are important ancient herbal medicines widely used for more than 2000 years. The clinical application of two species herb is confused due to the difficult identification. Objective: The objective was to authenticate the species of BaiJiangCao and analyze the accumulation of bioactive ingredients based on characteristic inorganic elements analysis. Materials and Methods: Content of 32 inorganic elements in BaiJiangCao from different habitats were determined by inductively coupled plasma-mass spectrometry (ICP-MS), and the characteristic inorganic elements were picked to distinguish the species of the herb by principal component analysis and cluster analysis. Contents of two bioactive ingredients, luteoloside, and oleanolic acid, in the samples, were also analyzed by high-performance liquid chromatography method. Relationship between accumulation of bioactive ingredients and content of macroelements in BaiJiangCao was established by statistics. Results: A 4 macroelements (Na, Mg, K, Fe) in 32 determined inorganic elements were picked for characteristic inorganic elements. Content of Na, Mg, K and Fe showed positive correlations with that of luteoloside, content of Na, Mg showed positive correlations with that of oleanolic acid, but content of K and Fe showed negative correlations with that of oleanolic acid. Conclusion: It is for the first time to utilize the characteristic inorganic elements as an index to classify the herb species by the method of ICP-MS and multivariate analysis. And it is also the first report to investigate the influence of inorganic elements in herb on the accumulation of bioactive components which could affect the pharmacological efficacy of the herb medicine. And this method could also be utilized in research of corresponding aspects.

The Effect of Solanine on the Membrane Potential of Mitochondria in HepG2 Cells and [Ca²+]i in the Cells

To observe the effect of solanine on the membrane potential of mitochondria in HepG2 cells and [Ca24]; in the cells, and to uncover the mechanism by which solanine induces apoptosis. HepG2 cells are double stained with TMRE and Fluo- 3/AM, and both the change in membrane potential of mitochondria and that of [Ca2+]; in the cells are observed using LCSM.The results of double staining with TMRE and Fluo-3/AM show that solanine can lower membrane potential and increase the concentration of Ca2+ in the cells Solanine opens up the PT channels in the membrane by lowering the membrane potential, leading to Ca2+ being transported down its concentration gradient, which in turn leads to the rise of the concentration of Ca2+ in the cell, turning on the mechanism for apoptosis.

Effect of Asparagus Polysaccharides on Migration Time of Erythrocytes in Tumor-Bearing Organisms Using High Performance Capillary Electrophoresis

This study analyzed the effect of Asparagus polysaccharides on the migration time of erythrocytes in tumor- bearing organisms. A mouse tumor model was developed in which mice were intraperitoneally injected with high, medium, and low dosages of Asparagus polysaccharides for 7 d. The erythrocytes were collected and prepared into suspensions, and the migration time of cells were measured using high performance capillary electrophoresis (HPCE). Experimental conditions included the following: capillaries, 75 mum x 50 cm; buffer for electrophoresis, phosphate solution containing hydroxypropylmethyl cellulose (0.1 mol/L, pH 7.4); injection pressure, 3.448 kPa; injection time, 10 s; separation voltage, 20 kV; column temperature, 25 degC. It was found that Asparagus polysaccharides can decrease the migration time of erythrocytes in tumor-bearing organisms, which was 17.20 min for the control group, 14.33 min for the low-dosage group, 11.95 min for the medium-dosage group, 13.03 min for the high-dosage group, and 11.42 min for the normal group. Compared with the negative control group, all three dosage groups were significantly different (P < 0.01). It was also found that Asparagus polysaccharides can change the migration time of erythrocytes in tumor-bearing organisms with the tendency to the condition in normal organisms, which is possibly because Asparagus polysaccharides can change the charges density on erythrocytes surface.

The Effects of TDI on Mice Marrow Cells

This paper is to study the effects of TDI on mice marrow cells . The effects of TDI were studied by laser scanning confocal microscope to investigate morphologic changing of the mice bone marrow cell and genotoxicity test -chromosomal aberration test and sister chromatic exchange (SCE) test. Results showed that the 1/16LC50 and 1/8LC50 dosage of TDI had no significant effects on the fluorescence pixels rate of RNA/DNA, the chromosome aberration rate and the frequencies of sister chromatic exchange of the mice (P>0.05), but both 1/4 LC50and 1/2 LC50 dosage had significant effects on the fluorescence pixels of RNA/DNA, and the chromosome aberration rate and the frequencies of sister chromatic exchange of the mice (P<0.01). TDI has the genetic toxicity.

Study on effects of two kinds of cactus polysaccharides on the protein contents and the lipid fluidity of erythrocyte membrane in S180 mice

To study the effects of two kinds of cactus polysaccharides on band 3 protein content, cross-linking protein content, and the lipid fluidity of erythrocyte membrane in S180 mice. Membrane protein content is analyzed by SDS-PAGE, and lipid fluidity of the membrane is measured by the Skinitzky method. The two kinds of cactus polysaccharide increase the content of band 3 protein, decrease the content of cross-linking protein, and increase lipid fluidity. For medical cactus polysaccharide, the effect of the medium dosage group is significant (P><0.01); but for edible cactus polysaccharide, it is the high dosage group that has a significant effect (P<0.01). By improving the functioning of erythrocyte membrane of tumor-bearing mice, the two kinds of cactus polysaccharides enhance their immunological function, and this may be one of the anti-tumor mechanisms of cactus polysaccharides.

The Effect of Solanine on the Membrane Potential of Mitochondria in HepG2 Cells and [Ca^2+]i in the Cells

To observe the effect of solanine on the membrane potential of mitochondria in HepG₂ cells and [Ca²⁺]_i in the cells, and to uncover the mechanism by which solanine induces apoptosis. HepG2 cells are double stained with TMRE and Fluo-3/AM, and both the change in membrane potential of mitochondria and that of [Ca²⁺]_i in the cells are observed using LCSM. The results of double staining with TMRE and Fluo-3/AM show that solanine can lower membrane potential and increase the concentration of Ca²⁺ in the cells Solanine opens up the PT channels in the membrane by lowering the membrane potential, leading to Ca²⁺ being transported down its concentration gradient, which in turn leads to the rise of the concentration of Ca²⁺ in the cell, turning on the mechanism for apoptosis.

Determination and Analysis of Toluene Diisocyanate Metabolites in Mice Using Gas Chromatography-Mass Spectrometry

This paper is to determine metabolites of toluene diisocyanate (TDI) in mice and deduced the pathway for toluene diisocyanate metabolism in the organism. Toluene diisocyanate was administered to mice for 2 weeks, samples of blood, feces, and urine were taken, and the structure of the toluene diisocyanate metabolites was determined using gas chromatography-mass spectrometry (GC-MS). Conditions for TDI chromatography: Supelco PTETM-5 chromatographic column (30 mm times 0.25 mm times 0.25 mum); initial column temperature: 90degC, which was maintained for 30 min, after which the temperature was increased at a rate of 40degC/min to 280degC, which temperature was then maintained for 5.25 min; temperature for the vaporizing chamber: 250degC; carrier gas: helium flowing at 1.0 mL/min. Conditions for chromatography of TDI metabolites in the organism: 94% methyl, 4% ethenyl-bonded-phase fused-silica capillary column (30 + 2 mX 0.25 + 0.02 mm); initial column temperature: 30degC, which was maintained for 5 min, after which the temperature was increased at a rate of 80degC/min to 280degC, which temperature was then maintained for 5 min; temperature for the vaporizing chamber: 250degC; carrier gas: helium flowing at 1.0 mL/min. Conditions for mass spectrometry: EI for ionization; 70 eV for ionization energy; 280degC for connecting tube temperature; 35-350 amu for range of scanning; and 1.0 muL for sample size. The results showed 2,4-toluene diisocyanate was metabolized into 2,4-diaminotoluene, which is completely the same in male and female animals. Under the conditions selected for GC-MS, TDI metabolites in the organism can be isolated. Endogenous impurities in the blood, feces, or urine of mice do not interfere with the measurements.

Calculation of the Effect of Solanine on the Michaelis Constant and the Maximum Reaction Rate of NAT

To explore how to calculate the effect of solanine on the Michaelis constant and the maximum reaction rate of NAT, high performance liquid chromatography (HPLC) was used, with 2-AF as substrate, and the rate at which 2-AF is acetylated into 2-AAF in intact HepG2 cells or in the cytoplasm of HepG2 cells as the reaction rate. The double reciprocal plot was made, with 1/S (reciprocal of the concentration of the substrate 2-AF) plotted against 1/V (reciprocal of the reaction rate), to yield a regression equation for calculating Km and Vmax. With intact HepG2 cells, the Km and Vmax for the negative control are 2.37times10-3plusmn8.37times10-5 mM and 9.16times10-4plusmn7.54times10-5 nmol/106 cells, respectively, and that the Km and Vmax for the solanine group are 2.22times10-3plusmn9.05times10-5 mM and 5.14times10-4plusmn3.72times10-5 nmol/106 cells, respectively. For the cytoplasm of HepG2 cells, the Km and Vmax for the negative control are 8.95times10-3plusmn2.61times10-4 mM and 2.55times10-6plusmn1.92times10-8 nmol/ minmiddotmg protein, respectively, and the Km and Vmax of the solanine group are 9.48times10-3plusmn3.63times10-4 Mm and 2.43times10-6plusmn1.32times10-8 nmol/minmiddotmg protein. Statistical analysis showed that, for both intact HepG2 cells and cytoplasm of HepG2 cells, Km does not differ significantly between the negative control and the solanine groups, but Vmax does differ significantly for these groups (P<0.05). Solanine is a non-competitive inhibitor for the 2-AF substrate of NAT.