Biomedical subjects

Ye Yang

Publications and source records attributed to Ye Yang.

25 records · Page 2Linked to original sources

PubMed2003

[Transplantation of fetal cardiomyocyte regenerates infarcted myocardium in rats].

OBJECTIVE: To investigate the feasibility and efficiency of fetal cardiomyocyte transplantation into the rat model of myocardial infarction. METHODS: Cardiomyocytes were isolated from aborted human embryos aged 12 - 16 weeks and cultured for 5 days to confirm their viability. Rat model of extensive myocardial infarction (MI) was established in 18 male Wistar rats by ligating the descending anterior branch of left coronary artery and the 18 rats were randomly divided into 2 groups: transplantation group (n = 7, 2 x 10(6) fetal cardiomyocytes were transplanted into the myocardial scar) and culture medium injection group (n = 6, culture medium was injected into the myocardial scar) 5 days after extensive MI was caused. Another 6 rats undergoing sham operation were used as controls. Echocardiography was performed before and 60 +/- 3 days after the implantation to assess the left ventricular (LV) remodeling and cardiac function. Then the rats were killed and their heart were harvested to undergo HE staining, immunohistochemical examination with antibody against human alpha-actin smooth muscle (SMA) isoform, and light microscopy. RESULTS: Light microscopy revealed the presence of engrafted human fetal cardiomyocytes in the infarcted myocardium and the presence of nascent intercalated disks connecting the engrafted fetal cardiomyocytes and the host myocardium. The engrafted fetal cardiomyocytes were SMA positive. Serial echocardiography revealed that cell transplantation prevented scar thinning, LV further dilatation and dysfunction while the control animals developed scar thinning, significant LV dilatation accompanied by progressive deterioration in LV contractility. CONCLUSION: Fetal cardiomyocytes can be implanted and survive in the infarcted myocardial cells, thus preventing the scar thinning, and LV further dilatation and dysfunction.

Animals↗

PubMed2003

Imaging the internal electronic structure of a surface adsorbate with low energy ions.

Time-of-flight spectra were collected for 2.5 keV 7Li+ backscattered from Fe surfaces covered with submonolayers of iodine. Li singly scattered from the adatoms has a consistently larger neutral fraction than for scattering from the substrate, implying a region of positive charge atop the iodine. The neutral fraction decreases for off-normal exit angles, indicating a nonuniform charge distribution around the polarizable adsorbates. This demonstrates that ion scattering can image the internal electronic structure of an adatom and provides an explanation for anomalous work function changes.

Journal Article↗

PubMed2003

[Study on the insulin and insulin receptor in the progression of renal ischemic and reperfusion].

OBJECTIVE: To evaluate the effect of insulin and it's receptor on the kidney of rabbit with acute ischemic/reperfusion injury. METHODS: Twenty three Japanese white rabbits were allocated randomly into the control group, ischemic/reperfusion group(IR group), and insulin treatment group(Ins-IR group). The IR group received clamping for 1 h followed by 2 h or 48 h of reperfusion. In the Ins-IR group, insulin injection (Ins 3U/kg, glucose 1.5 g/kg, K+ 4 mg/kg, Mg2+ 1.7 mg/kg) was administered intravenously twice a day for two days, whereas only normal saline in equal amount was given to the IR group and control group. At 2 h or 48 h after reperfusion, glucose and insulin in serum were determined. Rough plasma of renal tissue was prepared by repeated centrifugation. Insulin receptor in renal tissue was analyzed by radiologand binding assay. The binding data were calculated according to Scatchard using the ligand program. Statistical significance was analyzed with the paired t-test. RESULTS: The level of blood glucose increased after 2 h reperfusion in three groups, but the level in IR group increased much higher than those in control and Ins-IR groups(P < 0.05). The level of serum insulin of IR group after 2 h reperfusion was significantly higher than that of control (P < 0.05). Scatchard analysis showed curvilinear profiles, indicating that there are two classes of receptors with different affinity or the presence of a single class of receptors with a negative cooperative hormone-receptor interaction. Data analyzed by a two-site model showed that the values of Bmax1 (high affinity site), Bmax2 (low affinity site) and Kd1, Kd2 after 2 h reperfusion were significantly lower than those of control (P < 0.05). In IR-Ins group, only Bmax2 decreased (P < 0.05, compared with control). 48 h after IR there was no difference in Bmax1, Kd1 between the 3 groups, but Bmax2 of IR-Ins group was still lower than that of control (P < 0.001) and IR group (P < 0.05). The Kd2 of IR group increased (P < 0.05 compared with control and IR-Ins group). CONCLUSION: The results indicate that the effect of intrinsic insulin decreases during renal ischemic/reperfusion. The extrinsic insulin can protect renal tissue through its high affinity receptor. There exits down-regulation of low affinity receptor but none of high affinity receptor during insulin treatment.

Animals↗

PubMed2002

[The plasma levels of proinsulin and true insulin and the effects of ramipril in hypertension].

OBJECTIVE: To explore the dynamic changes of plasma proinsulin (PI) and true insulin (TI) and their relation with essential hypertension (EH) as well as to evaluate the therapeutic effect of ramipril. METHODS: PI, TI and immunoreactive insulin (IRI) were measured in 44 cases of EH, 24 normal subjects and 21 cases of EH before and after treatment with ramipril. RESULTS: The mean plasma level of PI and IRI in EH was significantly higher than that in the control group (P < 0.01); there was no significant difference in the level of TI (P > 0.05). PI was positively related to TI, There was no significant relation between PI with SBP and DBP. Plasma concentration of IRI and PI (P < 0.05), decreased remarkably, but the level of TI remained unchanged after therapy with ramipril (n = 21). CONCLUSION: The plasma concentration of PI is elevated in patients with EH due probably to impaired function of beta-cells of the pancreatic islets. Ramipril can decrease the level of PI and improve pancreatic beta cell function.

Adult↗

PubMed2002

[Influence of pH control on the production of curdlan by Alcaligenes faecalis strain].

A two-stage pH control method was employed in batch fermentation of curdlan by Alcaligenes faecalis WX-C12 where cell-growth stage was constantly controlled at pH 7.0 and stationary stage was controlled at a constant pH as well. The influence of pH control on the curdlan production was investigated. The optimal pH control of batch process for curdlan production was obtained when cell-growth stage was controlled at pH 7.0 and stationary stage was constantly controlled at pH 5.6. Production and productivity of curdlan, QP and YP/S reached 28.19 g/L, 291 mg/(L.h), 132.27 mg/(L.h.g) and 0.659, an improvement of 20.4%, 38.1%, 38.1% and 29.5% compared to a pH uncontrolled operation respectively.

Alcaligenes↗

PubMedDate not supplied

Blood cell counting and classification by nonflowing laser light scattering method.

We present a nonflowing laser light scattering method for automatically counting and classifying blood cells. A linear charge-coupled device (CCD) and a silicon photoelectric cell (which is placed behind a pinhole plate on the CCD) form a double-detector structure: the CCD is used to detect the scattered light intensity distribution of the blood cells and the silicon photoelectric cell to complete the focusing process. An isotropic sphere, with relative refractivity near 1, is used to model the blood cell. Mie theory is used to describe the scattering of white blood cells and platelets, and anomalous diffraction, red blood cells. To obtain the size distribution of blood cells from their scattered light intensity distribution, the nonnegative constraint least-squares (NNLS) method combined with the Powell method and the precision punishment method are used. Both numerical simulation and experimental results are presented. This method can be used not only to measure the mean and the distribution of red blood cell size, but also to divide the white blood cells into three classes: lymphocytes, middle-sized cells, and neutrocytes. The experimental results show a linear relationship between the blood cell (both white and red blood cells) concentration and the scattered light intensity, and therefore, the number of blood cells in a unit volume can be determined from this relationship.

Adult↗

PubMedDate not supplied

Physical activity patterns among women in rural Alabama.

OBJECTIVE: To explore factors associated with physically active women in a rural community. METHODS: Physical activity patterns were assessed in 585 women in rural Alabama. RESULTS: When combining leisure and nonleisure activities, 68% of women reported > or = 150 minutes per week. Active African American women tended to be younger (AOR 0.97), married (AOR 1.75), less likely to report arthritis (AOR 0.58), or give health (AOR 0.30) or motivational reasons (AOR 0.39) for not being more active; active white women were less likely to report lower health perception (AOR 0.51). CONCLUSION: Ethnic differences in factors associated with higher activity levels need to be considered in physical activity interventions.

Adult↗