Biomedical subjects

Xue-jun Yu

Publications and source records attributed to Xue-jun Yu.

6 recordsLinked to original sources

PubMed2006

[Beneficial effects of probucol on endothelial function in patients with acute coronary syndrome].

OBJECTIVE: The study investigate the antioxidant probucol on endothelial function in patients with acute coronary syndrome (ACS). METHODS: A total of 49 ACS patients randomly received standard therapy plus probucol (P, n = 24) or standard therapy (C, n = 25). Plasma oxidized low-density lipoprotein (ox-LDL), nitric oxide (NO) and circulating endothelial cells (CEC) were measured. The brachial arterial hyperemia-induced flow mediated dilation (FMD) and sublingual nitroglycerin (NTG) mediated vasodilatations were measured by high resolution ultrasound. These variables were analyzed before and after 3 months therapy. RESULTS: Plasma NO and FMD was significantly increased after 3 months therapy than before therapy [(80.46 +/- 10.24) micromol/Lvs (48.46 +/- 12.24) micromol/L, P < 0.01; (13.46 +/- 1.20)% vs (7.45 +/- 1.02)%, P < 0.05, respectively], while the number of CEC and ox-LDL were significantly decreased (P < 0.01) in P group. These values were similar before and after 3 months in C group. The linear correlation analysis showed that plasma ox-LDL negatively correlated with NO (r = -0.574, P < 0.01) and FMD (r = -0.517, P < 0.01) and positively correlated with CEC (r = 0.385, P < 0.01) in patients received 3 months probucol therapy. CONCLUSIONS: Chronic antioxidant probucol therapy could improve endothelial function in patients with ACS.

Adult↗

PubMed2005

[Effects of paclitaxel combined with bone marrow stromal stem cells implantation on vascular endothelial repair and smooth muscle cells growth in vitro].

OBJECTIVE: To investigate the effects of paclitaxel combined with bone marrow stromal stem cells (MSCs) implantation on inhibiting the smooth muscle cells (SMCs) growth and promoting endothelial repair by developing an endothelial repair model in vitro. METHODS: In a cell coculture system, rabbit endothelial cells (ECs) and human MSCs were seeded in the lower chamber and rabbit SMCs were seeded in the upper chamber. 3H-TdR incorporation and PCNA protein expression were used to evaluate SMCs proliferation at the 10th day after paclitaxel application (1, 10, 100 nmol/L; 20 min). Fluorescence immunocytochemistry was employed to observe the Flk-1 and vWF protein expression on MSCs. RESULTS: The SMCs 3H-TdR incorporation of the MSCs implant group was significantly lower than that of the proliferative ECs group (1 nmol/L: 12 265 +/- 991 vs. 14 505 +/- 1013 cpm/well; 10 nmol/L: 8401 +/- 783 vs. 10 511 +/- 934 cpm/well; 100 nmol/L: 5880 +/- 569 vs. 7457 +/- 768 cpm/well, n = 6, P < 0.05), but higher than that of the confluent ECs group (1 nmol/L: 12 265 +/- 991 vs. 8671 +/- 642 cpm/well; 10 nmol/L: 8401 +/- 783 vs. 6175 +/- 743 cpm/well; 100 nmol/L: 5880 +/- 569 vs. 4423 +/- 406 cpm/well, n = 6, P < 0.05). The expression of SMCs PCNA protein in MSCs implant group was lower than that of the proliferative ECs group (1 nmol/L: 0.92 +/- 0.06 vs. 1.15 +/- 0.07; 10 nmol/L: 0.97 +/- 0.07 vs. 1.07 +/- 0.08; 100 nmol/L: 0.91 +/- 0.05 vs. 1.18 +/- 0.11, n = 6, P < 0.05), but higher than that of the confluent ECs group (1 nmol/L: 0.92 +/- 0.06 vs. 0.74 +/- 0.07; 10 nmol/L: 0.97 +/- 0.07 vs. 0.78 +/- 0.06; 100 nmol/L: 0.91 +/- 0.05 vs. 0.71 +/- 0.05, n = 6, P < 0.05). The MSCs did not express vWF or Flk-1 protein before coculture. Although none cell expressed vWF, some of the MSCs began to express Flk-1 protein after cocultured with mature ECs for 10 days. CONCLUSION: MSCs implantation can partly inhibit the delayed SMCs proliferation. The MSCs cocultured with paclitaxel-treated mature ECs have the ability to differentiate into ECs.

Bone Marrow Cells↗

PubMed2005

[The relationship between circulating endothelial progenitor cells and the risk factors of CHD as well as the severity of coronary lesions, and its clinical significance].

OBJECTIVE: To investigate the correlation between circulating endothelial progenitor cells (EPCs) and the risk factors of coronary heart disease (CHD) as well as the severity of coronary lesions, and its clinical significance. METHODS: 42 patients with CHD and 36 patients excluding CHD (control) were studied. Total mononuclear cells were isolated from peripheral blood by Ficoll density gradient centrifugation, and were cultured in M199 medium supplemented with 20% fetal bovine serum, 50 ng/ml vascular endothelial growth factor (VEGF). After 14 days cultured, the numbers of colony-forming units of EPCs were counted by phase-contrast microscope. The relationship between the number of colony-forming units of EPCs and the risk factors of CHD (such as age, gender, hypertension, hypercholesterolemia, diabetes, smoking, positive family history of CHD) as well as the severity of coronary lesions were assessed. RESULTS: The number of risk factors of CHD was significantly correlated with a reduction of EPCs levels (r = -0.436, P = 0.014). Smoking was associated with significantly lower EPCs levels, whereas a minor but nonsignificant reduction of EPCs levels was detected in the presence of gender, hypertension, and a positive family history of CHD. It was observed that low density lipoprotein (LDL) and uric acid were negatively correlated with the number of colony-forming units of circulating EPCs (P < 0.05). A correlation existed between age, high density lipoprotein, apoprotein A and levels of circulating EPCs, however, this relation was not statistically significant. The number of colony-forming units of circulating EPCs in CHD groups was significantly lower than those in control group (12.8 +/- 6.34 versus 37.0 +/- 5.5, P < 0.001); and the circulating EPCs level of coronary artery lesion group (including single, double, triple vessels disease) was significantly lower than that of control group (P < 0. 01). CONCLUSIONS: The level of circulating EPCs was inversely associated with the risk factor scores of CHD and the severity of coronary artery lesion. These finding imply that endothelial injury in the absence of sufficient circulating EPCs may affect the degree of the heart disorder and the clinical situation.

Aged↗

PubMed2003

[Research in space environmental medicine: review and future].

The investigation progress of space environmental medicine in China is summarized. Then, the application of space environmental medicine to formulating medical requirements for the crew module design, and performing medical evaluation for Shenzhou spaceship are addressed. Additionally, the medical and engineering means for the protection from harmful agents during spaceflight is illustrated. Finally, the objective and challenge of space environment medicine faced in the future research in China are presented.

Aerospace Medicine↗

PubMed2002

[Effects of head-down bedrest on surface temperature distribution and non-evaporative heat dissipation].

OBJECTIVE: To study effect of simulated weightlessness on non-evaporative heat dissipation from different parts of the human body. METHOD: Body surface temperature distribution of five subjects was measured under -6 degrees head down bedrest for 7 d with HR-II infrared thermography. Non-evaporative heat dissipation was calculated with the heat exchange equations based on surface temperature. RESULT: The temperature difference between torso and extremities increased during bed rest, and the largest was 6.7 degrees C higher than the control on the 3rd day of bed rest. The part of non-evaporative heat dissipation from the torso increased about 6% and that from head-neck increased 2%. At the same time, the parts of heat dissipation from the upper and lower extremities decreased about 3% and 5% respectively. CONCLUSION: The parts of non-evaporative heat dissipation from different areas of the human body changed during simulated weightlessness. This result provided a basis for the flow distribution design of liquid cooling garment of EVA suit.

Arm↗

PubMed2002

[Body temperature changes during 7 d -6 degrees head-down bed rest].

Objective. To investigate body temperature changes in man during 7-day -6 degrees head-down bed rest (BR). Method. Body temperatures were measured in the morning (6:00), afternoon (16:00) and evening (20:00) during 7 d BR in 18 healthy males (18-22 years old). Result. Rectal temperature (Tre) in the morning gradually decreased as time (d) of BR increased: after the 4th day of BR (BR4d), Tre significantly reduced compared with the supine control (SC, 36.50 +/- 0.03 degrees C) before BR, and it consistently declined to 36.38 +/- 0.04 degrees C on BR7d; But Tre significantly increased in the afternoon after BR5d and in the evening after BR1d, with the final increments of 0.12 +/- 0.05 degrees C and 0.25 +/- 0.03 degrees C respectively on BR7d. Mean body temperature (Tsk) in the morning was significantly higher from BR2d than its SC, with a final net increase (delta Tsk) of 0.38 +/- 0.14 degrees C on BR7d. And Tsk significantly increased in the afternoon and evening from BR4d, BR2d respectively. Skin temperature on the forehead (Tforehead) elevated in the morning during BR. While in the afternoon and evening, Tforehead were significantly higher from BR7d and BR6d than their SC. Conclusion. Both the difference in time of recording at a BR day and the time (d) of BR have significant influence on Tre, Tsk , and Tforehead (P<0.01). These data suggest that body temperature rhythm, body fluid loss and headward distribution, hypokinesis etc. induced by BR have an impact on human thermal regulation during BR.

Adolescent↗