Biomedical subjects

Xue-Min Cheng

Publications and source records attributed to Xue-Min Cheng.

3 recordsLinked to original sources

PubMed2006

Ketopiperazine-based renin inhibitors: optimization of the "C" ring.

A systematic investigation of the S3 sub-pocket activity requirements was conducted. It was observed that linear and sterically small side chain substituents are preferred in the S3 sub-pocket for optimal renin inhibition. Polar groups in the S3-sub-pocket were not well tolerated and caused a reduction in renin inhibitory activity. Further, compounds with clog P's < or = 3 demonstrated a dramatic reduction in CYP3A4 inhibitory activity.

Crystallography, X-Ray↗

PubMed2006

[Research in the relation between telomerase reverse transcriptase expression in spermatogenic cells and serum levels of estradiol of fluorotic rats].

OBJECTIVE: To study the relation between telomerase reverse transcriptase (TERT) activity expression in spermatogenic cells and serum levels of estradiol of fluorotic rats. METHODS: We randomly divided thirty SD male rats into control group, low-dose group and high-dose group, then inject sodium fluoride (0, 10, 20 mg/kg bw) into celiac of rats. We respectively observed changes of estrogen and TERT using methods of radioimmunoassay, in situ hybridization. In addition, we observed the quality of spermatozoa. RESULTS: The level of estrogen, the expression of telomerase and the number and the livability of the spermatozoon in low-dose and high-dose fluorotic rats were lower than those of control rats (P < 0.05). Therefore,the above indexes decreased with the increase of dosage. In addition, sperm aberration of each fluorotic group was higher than control group (P < 0.05). And it increased with the increase of dosage. The content of E2 in serum of different fluoride treatment groups was positively correlated with the expression of telomerase in seminiferous tubule significantly, respectively (low-dose fluoride treatment groups, r = 0.941, P < 0.01, high-dose fluoride treatment groups, r = 0.929, P < 0.01). CONCLUSION: NaF possibly damaged the male reproductive system by the approach of E2/ER-TERT-spermatozoon, relation between TERT expression in spermatogenic cells and serum levels of estradiol is positive correlation.

Animals↗

PubMed2005

[Relationship between spermatogenic cell apoptosis and serum estradiol level in rats exposed to fluoride].

OBJECTIVE: To observe the relationship between spermatogenic cell apoptosis and serum estradiol level in rats exposed to fluoride. METHODS: A total of 30 male Wistar rats were allocated into six groups randomly. The six experimental groups were 28-day control group, 28-day low-dose fluoride treatment group, 28-day high-dose fluoride treatment group, 38-day control group, 38-day low-dose fluoride treatment group, and 38-day high-dose fluoride treatment group. The fluorosis model was acquired by subcutaneous injection of NaF solution. The content of NaF in testis was measured by using fluorine selective electrode. The serum estradiol level was radioimmunochemically detected. And the apoptotic spermatogenic cells were quantitatively measured by TUNEL. RESULTS: The content of NaF in testis and the ratio of apoptotic spermatogenic cell in fluoride treatment groups significantly increased with increased experimental dosage and prolonged experimental period (P < 0.05). Meanwhile, the serum estradiol level significantly decreased (P < 0.05), which was negatively correlated with the content of NaF in testis as well as the ratio of apoptotic spermatogenic cell (P < 0.05). CONCLUSION: Excessive fluoride could lead disturbance to serum estradiol level during some range of dose and time, which is an important factor to spermatogenic cell apoptosis.

Animals↗