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Biomedical subjects

Yi Feng

Publications and source records attributed to Yi Feng.

59 records · Page 4Linked to original sources
PubMed2003

[Preparation and identification of the monoclonal antibody against human endostatin].

AIM: To prepare monoclonal antibody against human endostatin for the in depth study on the mechanism of anti-tumor effect of endostatin. METHODS: Monoclonal antibody specific for endostatin was prepared using hybridoma technique and screened with ELISA. Ascites fluids were produced in BALB/c mice following in sequentical intraperitoneal injection of pristine and hybridoma cells. The mAb was purified by affinify chromatography with protein A sepharose CL-4B. RESULTS: One hybridoma cell line 4E7 was established, which could produce mAb against human endostatin. The titers of mAb 4E7 in culture supernatant and ascites fluid were 1:128-1:516 and 1:10(-4)-1:10(-6), respectively. The mAb 4E7 belonged to IgG1 (lambda type). Western blot analysis showed that the mAb 4E7 could react to the human endostatin expressed by yeast and E.coli, but it had no cross reaction to other cytokines such as bFGF. CONCLUSION: The mAb 4E7 is able to react specifically with human endostatin and can be used for further investigation.

Animals↗
PubMed2002

[Clinical study on treatment of HIV infected persons based on viral load detection and CD4+ T lymphocyte counting].

OBJECTIVE: To study the usage of viral load and CD4+ cell count methods in evaluating the effects of clinical treatment in HIV infected people. METHODS: Totally 73 cases of HIV infected persons were studied with clinical observation and laboratory examinations, six cases were treated with cocktail therapy, 36 cases with chinese herbs and the other 31 cases were untreated. RESULTS: The results indicated that the viral load levels in cocktail therapy group were significantly lower than the other two groups within 3 months and then kept at very low level. The CD4+ T lymphocyte levels showed a significant increase after 3 months and kept rising up. The chinese herb group, however, had no significant difference in viral load level and CD4+ T lymphocyte level as compared with untreated group. But in clinical observation chinese herbs showed the effect of improving clinical status in some cases. CONCLUSIONS: The authors conclude that the viral load and CD4+ count are efficient methods in clinical evaluation of HIV treatment, especially in routine anti-HIV therapy. As for the chinese herbs treatment, these two monitors did not reflect changes in clinical status.

Anti-HIV Agents↗
PubMed2002

[The CXC-chemokine platelet factor 4 (PF4) increases KG1a cells adherence and modulates actin polymerization of KG1a cells].

OBJECTIVE: To study the effects on adherence of hematopoietic stem/progenitor cells, PF4 was assessed alone or in combination with IL-3 for effects on the total adherence and various kinds of adhesion molecules of KG1a cells as well as actin polymerization in KG1a cells. METHODS: The total adherence was assayed by crystal violet dye staining. The adhesion molecule expression was determined by FACS analysis. These adhesion molecule monoclonal antibodies individually blocked total adherence by MTT. F-actin content was monitored by fluorospectrophotometry. RESULTS: 100 ng/ml PF4 could increase the total adherence of KG1a cells by 80%. 20 ng/ml IL-3 could increase the total adherence of KG1a cells by 96%. When PF4 and IL-3 were combined, the total adherence could be promoted by 97%. Exposure of 1 x 10(6) cells/ml of KG1a cells to 100 ng/ml PF4 the increased total adherence of KG1a cells was mediated by PECAM-1 (CD31), CD44, LFA-1 (CD11a) and Mac-1 (CD11b) but not by P-selectin (CD62P) and E-selectin (CD62E). These adhesion molecule monoclonal antibodies could individually block total adherence for 34%-43%. Similar phenomenon was observed when IL-3 was added onto KG1a cells. Further study found that PF4 induced actin polymerization of KG1a cells. CONCLUSIONS: Our study indicated that PF4 promoted total adherence, as well as several adhesion molecule expression and actin polymerization of KG1a cells. The results suggest that PF4 may have therapeutic utility along with other cytokines by enhancing the total adhesion of hematopoietic stem/progenitor cells to promote the homing.

Actins↗
PubMedDate not supplied

Magnetic resonance imaging of acute reperfused myocardial infarction: intraindividual comparison of ECIII-60 and Gd-DTPA in a swine model.

PURPOSE: To compare a necrosis-avid contrast agent (NACA) bis-Gd-DTPA-pamoic acid derivative (ECIII-60) after intracoronary delivery with an extracellular agent Gd-DTPA after intravenous injection on magnetic resonance imaging (MRI) in a swine model of acute reperfused myocardial infarction (MI). METHODS: Eight pigs underwent 90 min of transcatheter coronary balloon occlusion and 60 min of reperfusion. After intravenous injection of Gd-DTPA at a dose of 0.2 mmol/kg, all pigs were scanned with T1-weighted MRI until the delayed enhancement of MI disappeared. Then they were intracoronarily infused with ECIII-60 at 0.0025 mmol/kg and imaged for 5 hr. Signal intensity, infarct-over-normal contrast ratio and relative infarct size were quantified, compared, and correlated with the results of postmortem MRI and triphenyltetrazolium chloride (TTC) histochemical staining. RESULTS: A contrast ratio over 3.0 was induced by both Gd-DTPA and ECIII-60. However, while the delayed enhancement with Gd-DTPA virtually vanished in 1 hr, ECIII-60 at an 80x smaller dose depicted the MI accurately over 5 hr as proven by ex vivo MRI and TTC staining. CONCLUSION: Both Gd-DTPA and ECIII-60 strongly enhanced acute MI. Comparing with fading contrast in a narrow time window with intravenous Gd-DTPA, intracoronary ECIII-60 persistently demarcated the acute MI, indicating a potential method for postprocedural assessment of myocardial viability after coronary interventions.

Animals↗