Biomedical subjects

Junying Xu

Publications and source records attributed to Junying Xu.

5 recordsLinked to original sources

PubMed2006

Postconditioning's protection of THSG on cardiac ischemia-reperfusion injury and mechanism.

2,3,5,4'-tetra-hydroxystilbene-2-O-glucoside (THSG), the water-soluble active components extracted from dried tuber root of Polygonum multiflorum (Polygonaceae), can promote the release of nitric oxide (NO) from vascular endothelial cells and has strong antioxidation. The postconditioning's protection of THSG on cardiac ischemia-reperfusion injury and the mechanism were investigated. After reperfusion for 3 h following occlusion of rat left anterior descending coronary artery (LAD) for 30 min, SalphaT recovery speed, arrhythmia and cardiac infarct size were observed. The ischemic size and infarct size was identified by using Evans blue and TTC staining methods respectively. The results showed that the infarct size in THSG 7. 5 mg/kg postconditioning group was significantly decreased from 43.6% +/- 9.1% in mode group to 16.5% +/- 6.5% (P < 0.01). SalphaT recovery was quicker and the incidence of arrhythmia (55.6% vs 100%, P < 0.05) was significantly lower than in control group. The infarct size in THSG+glybenclamide group was greater than in THSG group, but equivalent to that in control group (46.8% +/- 9.8% vs 43.6% +/- 9.1%, P > 0.05), SalphaT recovery speed slower and the incidence of arrhythmia also lower (33.3% vs 100%, P < 0.01), suggesting that glybenclamide could abolish the effects of THSG postconditioning reducing the cardiac infart size. It was concluded that THSG administration before reperfusion could effectively alleviate the cardiac reperfusion injury and possessed the postconditioning effects of reducing cardiac infarct size, which might be related with the K(ATP) channel opening.

Animals↗

PubMed2006

Peripheral mechanisms of sibutramine involving proximal gastric motility in dogs.

OBJECTIVE: Sibutramine, a serotonin-norepinephrine uptake inhibitor, has been used for treating obesity. However, its possible mechanisms involving gastric motility have not been reported. The aim of this study was to evaluate the effects of sibutramine on gastric accommodation and antral motility. RESEARCH METHODS AND PROCEDURES: The study was performed in seven dogs with a stomach cannula and composed of two separate experiments: antral contractions and gastric tone. Each experiment included two sessions on 2 separate days in a randomized order: a control session and a treatment session with sibutramine (5 mg/kg per os) administrated 2 hours before the study. RESULTS: Sibutramine significantly increased fasting gastric tone; the gastric volume in the fasting state at baseline was 103.8 +/- 12.3 mL and significantly decreased to 35.3 +/- 16.0 mL with sibutramine (p = 0.0075). Sibutramine also impaired gastric accommodation. The average postprandial gastric volume was 472.1 +/- 16.7 mL in the control session and reduced to 302.2 +/- 53.6 mL with sibutramine (p = 0.013). The average postprandial increase in gastric volume during the 60-minute postprandial period with sibutramine was significantly lower than the corresponding values in the control session: 266.8 +/- 46.1 vs. 393.9 +/- 15.3 mL (p = 0.03). Sibutramine had no effects on postprandial antral contractions. DISCUSSION: Sibutramine increases gastric tone and impairs gastric accommodation to an orally ingested meal. The inhibitory effect of sibutramine on gastric accommodation may partially explain the reduced food intake with sibutramine in patients with obesity.

Animals↗

PubMed2003

Temporal response of a random medium from speckle intensity frequency correlations.

We reconstruct the temporal response of a random medium by using speckle intensity frequency correlations. When the scattered field from a random medium is described by circular complex Gaussian statistics, we show that third-order correlations permit retrieval of the Fourier phase of the temporal response with bispectral techniques. Our experimental results for random media samples in the diffusion regime are in excellent agreement with the intensity temporal response measured directly with an ultrafast pulse laser and a streak camera. Our speckle correlation measurements also demonstrate sensitivity to inhomogeneous samples, highlighting the potential application for imaging within a scattering medium.

Journal Article↗

PubMed2002

Characteristics of acid reflux in Barrett's esophagus.

To determine the relationship between Barrett's esophagus (BE) and features of gastroesophageal acid reflux, 24 h esophageal pH monitoring was performed in 90 patients. The patients were divided into 3 groups: 31 subjects with BE, 21 with mild esophagitis and 38 with severe esophagitis. The following parameters were evaluated: the percentage time of pH < 4; the number of reflux episodes over 5 min; the duration of longest episodes and DeMeester score over total period and the auterior three parameters in erect and supine position. All these parameters in BE were significantly different from those with mild esophagitis (P < 0.01) and not significantly different from those with severe esophagitis (P > 0.05). During supine position all the above parameters in BE were significantly different from those with reflux esophagitis (P < 0.05). It is concluded that the quantity of acid reflux is not an important factor in development of BE in gastroesophageal reflux (GER), and the acid reflux in supine position might be important in development of BE in GER.

Adult↗

PubMed2002

Analysis on the causes for refractory GERD.

To analyze the causes of failure in conventional treatment to refractory gastroesophageal reflux diseases (GERD) patients, 16 refractory GERD patients (group R) and 16 cases of GERD primarily diagnosed (group P) were studied. Endoscopy, pathologic examination and 14C urea breath test were conducted in every patient. 24 h ambulatory pH and bilirubin monitoring were performed with Digitrapper MK III and Synetics Bilitec 2000. It was found that esophagitis in group R was more severe than in group P. The rate of Helicobacter pylori infection in group R was significantly lower than in group P. Fraction time pH below 4.00 was not longer while the bile reflux represented by fraction time abs above 0.14 was greater for patients in the group R as compared with those in the group P. The mixed refluxes and pure bile refluxes between the two groups had significant difference. The reflux episodes in the group R mainly occurred during nights. These results indicated that severe esophagitis, especially Barrett's esophagus with complications makes it difficult to control GERD. Severe duodenogastroesophageal refluxes (DGER) are often accompanied by refractory GERD. Mixed refluxes aggravate the esophageal injuries. Pure bile refluxes and nocturnal refluxes may cause failure of administration of proton pump inhibitors (PPI) in the morning. Helicobacter pylori infection and acid refluxes may not be the direct cause of refractoriness. Individual refractory GERD patient without abnormal results on pH or bile reflux recently should be diagnosed again.

Adult↗