Biomedical subjects

Wei Ouyang

Publications and source records attributed to Wei Ouyang.

21 records · Page 2Linked to original sources

PubMed2002

[Relationship between risk factors for coronary artery disease and thallium-201 myocardial scintigraphy].

OBJECTIVE: To investigate the relation of 5 major risk factors (hypertension, diabetes, hyperlipidemia, overweight, smoking) of coronary artery disease (CAD) to the findings from thallium-201 single photon emission computed tomography. METHODS: Exercise 201TI myocardial scintigraphy was performed in 346 patients with clinically suspected CAD, who were divided into no risk, low risk, moderate risk, and high risk groups, based on CAD risk scores. RESULTS: The rate of thallium-201 perfusion abnormalities in no risk, low risk, moderate risk, and high risk groups were 48.1%, 70.6%, 89% and 100%, respectively, showing significant difference between them (X2=49.6, P=0.000 1). In patients with CAD risk factors, significant relation was found between the risk scores and semiquantitative scores, lung-to-heart ratios or segment abnormalities (0.133 r 0.450, 0.000 1 P 0.031). CONCLUSION: A close relation between CAD risk factors and thallium-201 myocardial scintigraphy is found. Routine thallium-201 myocardial scintigraphy should be performed in patients clinically suspected of coronary artery disease with CAD risk factors, especially those with moderate to high risk factors.

Adult↗

PubMed2001

Thallium-201 myocardial scintigraphy in hypertensive patients with and without left ventricular hypertrophy: a clinical study.

OBJECTIVE: To evaluate the myocardial perfusion in hypertensive patients with and without left ventricular hypertrophy using thallium-201 (201TI) myocardial scintigraphy and explore the mechanism that causes the perfusion abnormalities. METHODS: Thallium-201 myocardial scintigraphy was performed in 85 patients with clinically suspected coronary artery disease to assess the myocardial perfusion status. For patients with myocardial perfusion abnormalities as indicated by the scintigraphy, coronary angiography was ordered within 1 month. RESULTS: The incidence of 201TI myocardial perfusion abnormalities in hypertensive patients with ventricular hypertrophy (85.7%) was significantly higher than that in the normotensive (39.3%, P<0.01) and hypertensive patients not complicated with hypertrophy (61.2%, P<0.05). The semiquantitative score was higher in the hypertensive patients with hypertrophy than in the normotensive (P<0.01) and hypertensive patients without hypertrophy (P<0.05). More hypertensive patients with hypertrophy (9/18) had normal results of coronary angiography than the normotensive (0/13, P=0.044) and hypertensive patients without hypertrophy did (3/19, P<0.05). CONCLUSIONS: A higher rate of 201TI perfusion abnormalities occurs in the hypertensive patients with ventricular hypertrophy, which may be attributed to the pathological changes in the major coronary vessels and to the coronary microvascular diseases as well.

Journal Article↗

PubMedDate not supplied

Superior cell delivery features of poly(ethylene glycol) incorporated alginate, chitosan, and poly-L-lysine microcapsules.

Microencapsulation is an emerging technology in the development of bioartificial organs for drug, protein, and delivery systems. One of the advancements in establishing an appropriate membrane material for live cell and tissue encapsulation is the incorporation of poly(ethylene glycol) (PEG) to the widely studied alginate microcapsules. The current study investigates the properties of integrating PEG to microcapsules coated with poly-L-lysine (PLL) and chitosan as well as a novel microcapsule membrane which combines both PLL and chitosan. Results show that microcapsules containing PEG can support cell viability and protein secretion. The addition of PEG to PLL and chitosan-coated microcapsules improves the stability of microcapsules when exposed to a hypotonic solution. We also compared the novel microcapsule with two other previously used microcapsules including alginate-chitosan-PEG and alginate-PLL-PEG-alginate. Results show that all three membranes are capable of providing immunoprotection to the cells and have the potential for long-term storage at -80 degrees C. The novel membrane containing PEG, chitosan, and PLL, however, revealed the highest cell viability and mechanical strength when exposed to external rotational force, but it was unable to sustain osmotic pressure. The study revealed the potential of using PEG-incorporated alginate, chitosan, and PLL microcapsules for encapsulating live cells producing proteins and hormones for therapy.

Alginates↗