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Biomedical subjects

S Q Yan

Publications and source records attributed to S Q Yan.

9 recordsLinked to original sources
PubMed1999

Tradescantia bioassays for the determination of genotoxicity of water in the Panlong River, Kunming, People's Republic of China.

The Panlong river passes through Kunming City and receives a large quantity of municipal sewage and wastewater from industrial effluent. Along the river, 20 sites were selected to collect water samples to assess the genotoxicity using two Tradescantia assays, the micronucleus (Trad-MCN) and the stamen-hair-mutation (Trad-SHM) assays. The lowest frequencies in the Trad-MCN assay and the Trad-SHM assay are 3.19 MCN/100 tetrads and 1.32 M/1000 stamen hairs, respectively. In the water samples obtained from the Songhua Reservoir, the MCN frequencies and mutation rates are not statistically significantly different from the data found for the negative control (2.49 MCN/100 tetrads and 0.71 M/1000 stamen hairs). Among the other water samples, 19 in Trad-MCN assay and 17 in Trad-SHM assay show significantly higher genotoxicity than the control. The highest genotoxicity was in samples No. 19 for the MCN assay (8.73 MCN/100 cells), over three times higher than the negative control, and in sample No. 11 for the SHM assay (4.30 M/1000), six times higher than the negative control, and were about the same as for the positive control (10.0 mg/l NaN3, 9.28 MCN/100 tetrads and 7.44 SHM/1000 stamen hairs), respectively. The peak frequencies for the Trad-MCN assays were observed in the water samples obtained from the sites that were near industrial and municipal wastewater that ran into the river as effluent. In general, the frequency of MCN and SHM mutations increased where the river passed through Kunming. The Trad-MCN assay seemed more sensitive than that of the Trad-SHM assay in detecting genotoxicity of the river water pollution.

Biological Assay↗
PubMed1995

[Protective effect of "wei tong ling" on gastric mucosa and influence on quality of gastric ulcer healing].

The acute gastric ulcer rat models were induced by dehydrated alcohol, 0.6 N hydrochloric acid and 0.6 N sodium hydroxide, and the chronic gastric ulcer rat models were established by means of acetic acid, the protective effect of Chinese medicine "Wei Tong Ling" (WTL) on gastric mucous membrane was studied. Using histochemical mucin stain, AgNOR stain and immunohistochemical technique the regenerated mucosa of healed gastric ulcer induced by acetic acid in rats was observed quantitatively. They were compared with that of WTL. The results showed that the regenerated mucosa of healed gastric ulcer might be the morphological basis for the recurrence of gastric ulcer and be associated with canceration. WTL could not only accelerate the healing of ulcer but also raise the quality of gastric ulcerous healing which was beneficial for the prevention of ulcer recurrence and canceration. The protective effect of WTL on gastric mucosa was confirmed by various assays.

Animals↗
PubMed1994

Effects of pollen from Typha angustata on the osteoinductive potential of demineralized bone matrix in rat calvarial defects.

Typha angustata Bony et Chaub. is a traditional Chinese medicine, commonly used in China for a variety of clinical disorders, including atherosclerosis, cardiovascular diseases, uterus contraction, and wound healing. The effect of the pollen of Typha angustata on the bone inductive capacity of demineralized bone matrix is studied here. Demineralized bone matrix soaked with saline solution was implanted in 8-mm defects in rat calvaria. After surgery all rats received a 0.2-ml injection in the defect sites of Typha angustata extract, plasma, or saline 3 times weekly for 2 to 4 weeks. The repair of bone defects was evaluated by radiography and by histology at 2 and 4 weeks after surgery. Results indicated that the 3% Typha angustata extract and demineralized bone matrix combination produced substantially more bone than demineralized bone matrix alone, while plasma plus demineralized bone matrix induced the same amount of bone formation as Typha angustata extract plus demineralized bone matrix. The osteoinductive potential increased in a dose dependent manner, 3% Typha angustata extract plus demineralized bone matrix produced more bone than the 0.6% Typha angustata extract plus demineralized bone matrix at 2 and 4 weeks. This study demonstrates that an extract of the pollen of Typha angustata is capable of enhancing the osteoinductive potential of demineralized bone matrix.

Animals↗
PubMed1992

[Advanced prostate cancer--an analysis of 17 cases].

Prostate cancer is a disease mostly effecting aged men. The incidence rate of this disease is much lower in China than in Europe and America. However, certain data have been accumulated indicating an increasing tendency in this country in recent years. The present report also supports this view and suggest the importance of strengthening of epidemiological research in this area in future. The problem how to treat patients with advanced prostate cancer is of essential importance since most cases are diagnosed in III or IV stage of the disease. In the present study, 10 out of 26 suspected cases (38.5%) was diagnosed by needle aspiration biopsy, being 90.9% of 11 cases confirmed histopathologically. The elevation of tumor maker acid phosphatase activity was positive in 8 out of 17 cases (47.1%). In this group, 11/17 (64.7%) received bilateral orchidectomy plus estrogenic hormones. The effective rate was 81.9% (9/11). Relapse occurred in 4 out of the 9 cases (44.4%), probably due to estrogenic hormone-dependence.

Acid Phosphatase↗
PubMed1989

[Studies on antibacterial constituents from Gerbera anandria (L.) Sch Bip. IV].

Thirteen compounds have been isolated from Gerbera anandria (L.) Sch Bip. Among them, three new compounds were elucidated by chemical correlations and spectral analyses. They are 3.8-dihydroxy-4-methoxy-coumarin (XIX), 3,8-dihydroxy-4-methoxy-2-oxo-2H-1-benzopyran-5-carboxylic acid (XVII), and 5,8-dihydroxy-7-(4-hydroxy-5-methyl-coumarin-3-)coumarin (XXI).

4-Hydroxycoumarins↗