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Ying Nie

Publications and source records attributed to Ying Nie.

4 recordsLinked to original sources
PubMed2005

Platelet cryopreservation using a trehalose and phosphate formulation.

Long-term storage of platelets is infeasible due to platelet activation at low temperatures. In an effort to address this problem, we evaluated the effectiveness of a formulation combining trehalose and phosphate in protecting platelet structure and function following cryopreservation. An annexin V binding assay was used to quantify the efficacy of the trehalose and phosphate formulation in suppressing platelet activation during cryopreservation. Of the platelets cryopreserved with the trehalose plus phosphate formulation, 23% +/- 1.2% were nonactivated, compared with 9.8% +/- 0.26% nonactivated following cryopreservation with only trehalose. The presence of both trehalose and phosphate in the cryopreservation medium is critical for cell survival and preincubation in trehalose plus phosphate solutions further enhances viability. The effectiveness of trehalose plus phosphate in preserving platelets in a nonactivated state is comparable to 6% dimethyl sulfoxide (Me(2)SO). Measurements of platelet metabolic activity using an alamarBlue assay also established that trehalose plus phosphate is superior to trehalose alone. Finally, platelets protected by the trehalose plus phosphate formulation exhibit similar aggregation response upon thrombin addition as fresh platelets, but an increase of cytosolic calcium concentration upon thrombin addition was not observed in the cryopreserved platelets. These results suggest that trehalose and phosphate protect several aspects of platelet structure and function during cryopreservation, including an intact plasma membrane, metabolic activity, and aggregation in response to thrombin, but not intracellular calcium release in response to thrombin.

Annexin A5↗
PubMed2005

Glucose dependence of the regulated secretory pathway in alphaTC1-6 cells.

We have investigated the effects of chronically elevated glucose concentrations on the pancreatic alpha-cell line alphaTC1-6. We show that basal glucagon secretion and proglucagon gene expression were increased in response to high glucose levels. The extent of acute stimulated secretion of glucagon was also increased in response to high glucose, as was the transcription of the prohormone processing enzymes PC1/3 and PC2. The secretion of GLP-1, a proglucagon-derived peptide produced by cleavage of proglucagon by PC1/3, was also increased in response to high glucose. Gene expression profiling experiments showed that a number of components of the regulated secretory pathway were up-regulated at high glucose concentrations, including processing enzymes and exocytotic proteins. Immunoblot analysis showed that the expression of the exocytotic SNARE proteins, as well as that of PC1/3, chromogranin A, and 7B2, were all increased after chronic exposure to high glucose levels. Immunocytochemistry showed no changes in the expression of the mature alpha-cell markers glucagon and brn-4 and no induction of the immature alpha-cell marker pdx-1. We conclude that chronically elevated glucose concentrations up-regulate the regulated secretory response of the alpha-cell.

Animals↗
PubMed2004

[Factors related to false positive results of treadmill electrocardiogram test for the detection of coronary heart disease].

OBJECTIVE: To investigate the clinical factors related to false positive results of electrocardiogram treadmill exercise test (TET) for the detection of coronary heart disease (CHD). METHODS: 258 patients with chest pain undergoing TET and coronary angiography (CAG) were on rolled. The case history and various clinical parameters were collected. (1) The results of TET and CAG were compared to evaluate the sensitivity, specificity and accuracy of TET; (2) Clinical informations of the true positive group and the false positive group were compared and a statistic analysis was carried out. RESULTS: The sensitivity, specificity and accuracy of TET for diagnosing CHD was 77.3%, 65.9%, and 69.8% respectively. The number of female in the false positive group was larger than that in the true positive group; The number of patients with typical chest pain, hyperlipidemic history, smoking history and family history of CHD was smaller than that in the true positive group. In the false positive group, the change of ST segment was mainly in II, III, aVF. The number of patients with change of more than 0.2 mV in ST and with angina induced during exertion was lower in the false positive group than in the true positive group. The difference was significant. CONCLUSION: Factors including sex, typical chest pain, risk factors of CHD, the location and extent of ECG changes and angina induced by exertion are closely related to false positive results of TET.

Adult↗