Biomedical subjects

You-Qin Chen

Publications and source records attributed to You-Qin Chen.

6 recordsLinked to original sources

PubMed2005

Differences in platelet endothelial cell adhesion molecule-1 expression between peripheral circulation and pancreatic microcirculation in cerulein-induced acute edematous pancreatitis.

AIM: To investigate the changes of platelet endothelial cell adhesion molecule-1 (PECAM-1) expression on polymorphonuclear leukocytes (PMNs) in peripheral circulation and pancreatic microcirculation in cerulein-induced acute edematous pancreatitis (AEP). METHODS: Fifty Wistar rats were randomly divided into control group (n = 10) and AEP group (n = 40). A model of AEP was established by subcutaneous injection of cerulein 5.5 and 7.5 mug/kg at 0 and 1 h after the beginning of experiment respectively. PECAM-1 expression on PMNs from splenic vein and inferior vena cava was determined by RT-PCR at mRNA level and determined by flow cytometry at protein level. RESULTS: In experimental rats, an increased PECAM-1 mRNA expression was seen from 4 to 8 h of AEP in peripheral circulation (0.77+/-0.25%, 0.76+/-0.28%, 0.89+/-0.30%, 1.00+/-0.21%), while in pancreatic microcirculation, expression decreased from 2 h and reached the lowest level at 6 h of AEP (0.78+/-0.29%, 0.75+/-0.26%, 0.62+/-0.28%, 0.66+/-0.20%). There were significant differences at 8-h time point of AEP between peripheral circulation and pancreatic microcirculation (1.00+/-0.21% vs 0.66+/-0.20%, P<0.05). Meanwhile, the difference at protein level was also found. CONCLUSION: A reverse expression of PECAM-1 on PMNs was found between peripheral circulation and pancreatic microcirculation, suggesting that inhibition of PECAM-1 expression may improve the pathological change of AEP.

Acute Disease↗

PubMed2005

Sulfasalazine inhibits activation of nuclear factor-kappaB in patients with ulcerative colitis.

BACKGROUND: Although sulfasalazine is widely used to treat inflammatory bowel disease, its mechanisms of action remain unclear. Activation of transcription factor nuclear factor (NF)-kappaB, which controls transcription of various pro-inflammatory cytokine genes, has been shown to play a critical role in the pathogenesis of inflammatory bowel disease. The purpose of the present study was to determine whether sulfasalazine therapy affected NF-kappaB activation and the expression of pro-inflammatory cytokines in patients with ulcerative colitis. METHODS: A total of 38 patients with moderate ulcerative colitis were investigated. Twenty-one patients received sulfasalazine. Seventeen patients did not receive any medication. Biopsy specimens were obtained from inflamed mucosa and analyzed for NF-kappaB DNA binding activity, NF-kappaBp65/IkappaBalpha protein expression and the levels of pro-inflammatory cytokine mRNA using electrophoretic mobility shift assay, western blot analysis, immunohistochemical staining and reverse transcription-polymerase chain reaction (RT-PCR) analysis, respectively. RESULTS: Increased activation of NF-kappaB and high levels of the expression of interleukin (IL)-1beta mRNA and IL-8 mRNA were detected in biopsy specimens from patients with ulcerative colitis. Therapeutic administration of sulfasalazine effectively downregulated the activation of NF-kappaB and the expression of IL-1beta mRNA and IL-8 mRNA while IkappaBalpha levels were stable. CONCLUSION: The therapeutic benefits for ulcerative colitis of sulfasalazine might at least in part be attributed to its ability to inhibit NF-kappaB activation, resulting in the downregulation of pro-inflammatory cytokine mRNA expression.

Adult↗

PubMed2004

Changes of cytosolic [Ca2+]i in neutrophils in pancreatic microcirculation of rats with caerulein-induced acute pancreatitis under fluid shear stress.

AIM: To investigate the fluid shear stress induced changes of (Ca(2+))i in neutrophils in pancreatic microcirculation of experimental acute pancreatitis (AP). METHODS: Wistar rats (n = 36) were randomized into three groups. A model of AP was established by subcutaneous injection of caerulein. Low-shear 30 viscometer was used to provide steady fluid shear stress on separated neutrophils. The mean fluorescent intensity tested by flow cytometry was used as the indication of [Ca(2+)]i quantity. RESULTS: Under steady shear, cytosolic [Ca(2+)]i showed biphasic changes. The shear rate changed from low to high, [(Ca(2+)]i in different groups decreased slightly and then increased gradually to a high level (P<0.05). A close correlation was observed between the cytosolic [Ca(2+)]i level and the alteration of fluid shear stress in regional microcirculation of AP. CONCLUSION: The increase of [Ca(2+)]i is highly related to the activation of neutrophils, which contributes to neutrophil adhesion to endothelium in the early phase of AP. The effect of fluid shear stress on [Ca(2+)]i may play a crucial role in pancreatic microcirculatory failure of AP.

Acute Disease↗

PubMed2004

Effect of inducible cyclooxygenase expression on local microvessel blood flow in acute interstitial pancreatitis.

OBJECTIVE: To investigate the role of inducible cyclooxygenase (COX-2) mRNA expression in local microvessels in rats with acute interstitial pancreatitis (AIP) induced by caerulein injection. METHODS: The reverse transcription polymerase chain reaction (RT-PCR) was used to detect COX-2 gene expression in pancreatic tissue. Parameters of acute pancreatitis, such as serum amylase (AMS) and plasma myeloperoxidase (MPO) activities, were assayed using spectrophotometry. Intravital fluorescence microscopy with fluorescein isothiocyanate-labelled erythrocytes was used to study the pancreatic microvessels of rats with AIP and normal control rats. RESULTS: Highly significant increases in COX-2 expression and AMS and MPO activity were seen in rats with AIP compared with controls. After caerulein injection, pancreatic capillary blood flow was decreased (4 hours, p > 0.05; 8 hours, p < 0.001), functional capillary density was reduced (4 hours, p > 0.05; 8 hours, p < 0.001), and there was irregular and intermittent capillary perfusion at 8 hours. There was also a positive correlation between the level of COX-2 expression and MPO activity (plasma, r = 0.5449, p < 0.05; tissue, r = 0.5698, p < 0.05). CONCLUSIONS: The correlations between increased COX-2 expression and decreased capillary perfusion and blood flow and increased oedema following AIP may show that COX-2 expression can induce neutrophil sequestration to the pancreas, which may be one of the cascading inflammatory factors in the development of AIP.

Acute Disease↗

PubMed2004

Effects of TCMP-1 on the changes of platelet endothelial cell adhesion molecule-1 expression in acute edematous pancreatitis.

BACKGROUND: Traditional Chinese medicine is a potent agent in the management of clinical and experimental acute pancreatitis (AP), but the molecular mechanism of its therapeutic action is unclear. Numerous experimental and clinical studies have shown that platelet endothelial cell adhesion molecule-1 (PECAM-1) is pivotal to leukocyte recruitment, which results in microcirculatory injury during inflammation, but its role in acute pancreatitis is poorly understood. We investigated the effects of a compound of traditional Chinese medicine pancreatitis-1 (TCMP-1) on the changes of platelet endothelial cell adhesion molecule-1 (PECAM-1) expression on polymorphonuclear leukocytes (PMNs) in acute edematous pancreatitis (AEP). METHODS: The model of acute pancreatitis was established by subcutaneous injection of caerulein, and TCMP-1 treated groups were given TCMP-1 by catheterization from mouth to stomach (20 ml/kg) immediately after first time subcutaneous injection of caerulein. The changes of expression of PECAM-1 on leukocytes from the blood of the splenic vein and inferior vena cava were determined by flow cytometry. RESULTS: In the AEP group, expression of PECAM-1 on PMNs was not significantly different between pancreatic microcirculation and systemic circulation at AEP2h and AEP4h time point. Then from AEP4h time point to AEP8h time point, expression of PECAM-1 was up-regulated in systemic circulation while it was down-regulated in pancreatic microcirculation and was significantly different between pancreatic microcirculation and systemic circulation at AEP8h time point (P<0.05). In the TCMP-1 treated group, compared with the AEP group, expression of PECAM-1 on PMNs decreased in different levels between pancreatic microcirculation and systemic circulation and was of significant difference at AEP8h time point (P<0.05). CONCLUSION: Inhibition of PECAM-1 expression on PMNs may prevent PMNs from transmigration through the endothelium and may be one of the treatment mechanisms of TCMP-1 decoction on AEP.

Acute Disease↗

PubMed2003

Expression of platelet endothelial cell adhesion molecule-1 between pancreatic microcirculation and peripheral circulation in rats with acute edematous pancreatitis.

OBJECTIVE: To study the changes of platelet endothelial cell adhesion molecule-1 (PECAM-1) expression on polymorphonuclear leukocytes (PMNs) in peripheral circulation and pancreatic microcirculation in rats with acute edematous pancreatitis (AEP). METHODS: The model of AEP was established with 50 Wistar rats, and the changes of PECAM-1 expression on PMNs from the splenic vein and inferior vena cava were determined by flow cytometry. RESULTS: PECAM-1 expression on PMNs showed no significant difference between pancreatic microcirculation and peripheral circulation at AEP2h and AEP4h time points. From the AEP4h to the AEP8h time point, PECAM-1 expression in peripheral circulation was up-regulated, but PECAM-1 expression in pancreatic microcirculation was down-regulated. PECAM-1 expression had a significant difference between pancreatic microcirculation and peripheral circulation at the AEP8h time point (P<0.05). CONCLUSION: PECAM-1 expression on PMNs is in a converse way between pancreatic microcirculation and peripheral circulation in AEP.

Acute Disease↗