PubMed Health⌕ Search

Biomedical subjects

Y F Song

Publications and source records attributed to Y F Song.

13 recordsLinked to original sources
PubMed2006

Earthworm cytochrome P450 determination and application as a biomarker for diagnosing PAH exposure.

We developed a new microsome purification method and used the Omura and Sato method to measure the total content of cytochrome (Cyt) P450 in earthworm (Eisenia fetida) microsomes. In method development, two different pretreatments, i.e. solubilization or manual separation were used to purify worm microsomes. Solubilization was more effective than manual separation and difference spectra showed a peak at 450 +/- 1 nm in microsomes received solubilization pretreatment. We conducted a 48 h contact test by exposing worms on pyrene (Py) and benzo[a]pyrene (BaP) spiked filter paper. A dose-response relationship was established between total P450 content and the concentration of Py or BaP ranging from 10(-6) mg mL(-1) to 10(-2) mg mL(-1). Results show that total Cyt P450 content in earthworms is a promising biomarker for diagnosing PAHs exposure at sublethal dose ranges.

Animals↗
PubMed2006

Polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and heavy metals (HMs) as well as their genotoxicity in soil after long-term wastewater irrigation.

A study was carried out on the residue level of major concern pollutants (PAHs, PCBs and HMs) and the assessment of their genotoxicity in soils obtained from Shenyang, northeast of China which had been subjected to wastewater irrigation for more than 40 years. Topsoils (0-20cm) in paddy fields were sampled along the upper, middle and lower reaches of the wastewater disposal channel. Sixteen USEPA PAHs were determined by High Performance Liquid Chromatography (HPLC) with fluorescence detector, eight PCBs were detected by Gas Chromatography (GC) with electron capture detector, and six heavy metals (Cd, Cu, Pb, Zn, Ni, and Cr) were measured by Atomic Absorption Spectrophotometer (AAS). The genotoxicity effect of soils was examined by Vicia faba micronucleus (MN) test. Archived soils that had undergone a similar history of wastewater irrigation provided by Technical University of Berlin, Germany were subjected to analysis of the above pollutants and Vicia faba/MN test for comparison. Results indicated elevated residues of the studied pollutants (PAHs, especially benzo (a) pyrene, the eight PCB congeners and heavy metals) in both tested and archived soils. The MN frequencies were 2.2-48.4 times higher compared with the control. However, there was no correlation between the MN frequencies and the concentration of pollutants detected. This investigation suggested a potential ecological risk even with a lower level of residual pollutants in soil matrix after long-term wastewater irrigation.

Environmental Monitoring↗
PubMed2002

Comparative study of extraction methods for the determination of PAHs from contaminated soils and sediments.

The following four methods were compared on the extraction efficiency of 16 EPA (US Environmental Protection Agency) polycyclic aromatic hydrocarbons (PAHs): German method of the Verband Deutscher Landwirtschaftlicher Untersuchungs und Forschungsanstalten (VDLUFA), two methods of the International Organization for Standardization using shaking (ISO A) and Soxhlet extraction (ISO B) and an ultrasonic method. Recovery rates of 16 PAHs were determined in two soils. Extraction efficiency was evaluated in five soils and three sediments. Effect of drying soils and sediments on extraction efficiency was tested using the VDLUFA and the ultrasonic methods. Our study shows that the number of aromatic rings, rather than extraction procedures, significantly influenced recovery rates of individual PAHs. No significant differences in extraction efficiency of the four methods were observed for less polluted samples. For highly polluted soils, extraction efficiency decreased in the following order: VDLUFA method > ISO A > ultrasonic method > ISO B. Influence of soil moisture on extraction efficiency depended to some extent on both solvent used and content of PAHs in samples. A mixture of dichloromethane/acetone (5:1) is recommended for PAH extraction from moist samples when the ultrasonic method is used.

Chemistry Techniques, Analytical↗
PubMed2001

Synthesis of novel potential antitumor agents: 2,6-dimethoxyhydroquinone-3-mercapto-acetyl peptide conjugates.

This paper reports on an ongoing study of the use of short chain peptides as carriers of a potential anti-tumor agent: 2,6-dimethoxyhydroquinone-3-mercaptoacetic acid (DMQ-MA). In an effort to carry out anti-cancer drug design, we synthesized three new peptide-DMQ-MA conjugates: DMQ-MA-Arg-Arg-Ome, DMQ-MA-Lys(Cbz)-Arg-Ome, DMQ-MA-Lys(Cbz)-Arg-Arg-Ome; two new DMQ-MA-peptide-Chlorambucil (CRB) derivatives: DMQ-MA-Lys(CRB)-Arg-Ome, DMQ-MA-Lys(DMQ-MA)-Lys(CRB)-Arg-Ome and four tripeptide-cytotoxic agent conjugates: DMQ-MA-Lys(DMQ-MA)-Phe-Arg-Ome, DMQ-MA-Lys(DMQ-MA)-Ile-Arg-Ome, DMQ-MA-Lys(DMQ-MA)-Val-Arg-Ome, DMQ-MA-Lys(DMQ-MA)-Lys(Cbz)-Arg-Ome. These conjugates were synthesized by coupling protected amino acid residues according to Pfp/DCC methods (Pfp: Pentafluorophenol, DCC:N,N'-Dicyclohexyl-carbodiimide) in solution. After deblocking the Boc- group of the Lysine, the conjugation was achieved by reaction with the pentafluorophenyl ester of DMQ-MA in DMF. The CRB in the side chain was coupled by deblocking the lysylcarbobenzyloxy protecting group Cbz and then reacting with the pentafluorophenyl ester of Chlorambucil(CRB). Further studies on cytotoxicity and sequence specificity of DNA alkylation of these five new conjugates are being investigated.

Adenocarcinoma↗
PubMed1998

A high-performance wide-range beamline for elliptically polarized undulator source.

A high-performance wide-range beamline has been designed for monochromatizing circularly polarized photons with energies from 10 to 1400 eV. A grazing SGM-based beamline with two entrance slits has been employed to optimize the performance. The degree of the circular polarization affected by the beamline optics has been analysed. The horizontal and vertical refocusing mirrors have been specially arranged to improve greatly the polarization degree in the low-energy region. By connecting this beamline to a high-efficiency elliptically polarized undulator, this beamline should be able to provide, in the entire energy range, intensive and high-resolution photons of a high degree of circular polarization.

Journal Article↗
PubMed1998

In vitro maturation of follicular oocytes of the Giant Panda (Ailuropoda melanoleuca): a case report.

The Giant Panda is an endangered species that would benefit from biotechnological assistance in reproduction. However, because there are only a few of these animals left in the world, scientists hesitate to use them for research procedures. We were fortunate to obtain ovaries from a Giant Panda that died of hepatic cirrhosis during the nonbreeding season. Oocytes were harvested within 4 h of death by dissecting the ovarian cortex in physiological saline and collecting the cumulus-oocyte complexes from the fluid, and then were classified into large (> 125 microns) and small (100 to 124 microns) follicular oocytes and placed in TCM199 supplemented with FSH (10 micrograms/mL) and LH (20 micrograms/mL). After culture for 22 h at 37 degrees C in air with 5% CO2, response was evaluated by growth of oocytes and presence of the first polar body. Of the 26 large follicular oocytes that were harvested, 12 were considered suitable for IVM, and 14 were degenerated, had a broken zona pellucida or had lost some cytoplasm. Of the 12 cultured oocytes, all grew to a mean diameter of 141.1(SD = +/- 6.7, n = 12), and 4 released the first polar body. None of the small follicular oocytes showed growth or other signs of maturation. We conclude from our preliminary results that it is possible to obtain functional Giant Panda oocytes from ovaries obtained post mortem during the nonbreeding season.

Animals↗
PubMed1998

[Studies on late replication bands of giant panda (Ailuropoda melanoleuca) chromosomes].

Using the cultured giant panda (Ailuropoda melanoleuca) lymphocytes as experimental material, we carried out the terminal marking on the chromosomes which were in replication by adding BrdU (a final concentration: 10 micrograms/ml) about four hours before harvesting the cells. The chromosomes marked by BrdU were proceeded by staining with acridine orange solution (0.05%), irradiated by ultraviolet and counter-stained by Giemsa, we obtained clear chromosomes replication patterns. According to the different replication bands, every chromosome's characteristics in late replication behavior could be identified. In the two X chromosomes of female individual, one X chromosome is obviously much later than the other one. Especially in the large area near centromere on the long arm of late replicating X chromosome. In the male individual, there is also a large area on the long arm of chromosome Y which replicates very late, but the end of long arm of chromosome Y replicates much earlier.

Animals↗
PubMed1994

[The rapid activation of human LAK cells and their inhibition on ovarian cancer at the advanced stage].

The study of generation of LAK cells from cord blood following a brief exposure to interleukin-2 (IL-2) demonstrated that a short time induction (15min-1h) of lymphocytes by a high concentration of IL-2 resulted in the maturation of LAK proceusor cells and such activated cells expressed cytolytic activity comparable to that of routinely induced (cultured continuously in IL-2 for 3-7 days) lymphocytes. Serologic test showed that this efficiency was not inhibited by autoserum. The results of experimental therapy with the two kinds of LAK cells in nude mouse model of human ovarian cancer confirmed that both types of LAK cells had remarkable inhibitory effect on tumor growth. The preliminary trial in the treatment of advanced ovarian cancer with rapid-pulsed LAK cells suggested that this method may serve as a new approach in the clinical application of tumor immunotherapy.

Animals↗
PubMed1986

Study on late effects of radioiodine on rats.

This paper describes the results observed on 850 male Wistar rats for two years after intraperitoneal injection with 131I, 132I or 125I of different radioactivities. The incidence of thyroid malignant tumor was 45.8% when the dose absorbed by the thyroid gland was 7.8 Gy in the 131I groups, and even tumors of lung and soft tissue, and malfunction of kidney and immune organs could be elicited when the radioiodine was overdosed. Both 132I and 125I have their optimal carcinogenic dose ranges and optimal doses of carcinogenesis. As the dosage decreases to a certain level, a low-limit dose incapable of inducing cancers may be present. 131I induced mainly papillary and mixed type carcinomas, 132I chiefly follicular and undifferentiated type carcinomas, while 125I induced follicular and medullary carcinomas. The paper also discusses cytochemical DNA quantitative assays of different histological types of thyroid gland carcinomas, holding that reference to such data as decreasing serum T4, elevating serum TSH and CIC may be helpful for early diagnosis of thyroid carcinomas.

Adenocarcinoma↗