Serum proteomics of early postoperative cognitive dysfunction in elderly patients

Background Studies on postoperative cognitive dysfunction （POCD） have attracted extensive attention and achieved significant progress. However, the diagnosis of POCD is not very satisfactory as no specific biomarkers have been classified. The aim of the present study was to evaluate differences in serum protein composition between POCD and Non-POCD patients, identify potential biomarkers associated with early POCD, and study the mechanism underlying POCD. Methods Sixty-eight elderly patients （age 〉65 years） received isoflurane inhalation anesthesia for arthroplasty surgeries. One day before and seven days after the surgery, these patients were subjected to a neuropsychological test and venous blood sample collection. Postoperative cognitive dysfunction was determined using Z test scores. Based on the results, the patients were divided into POCD and non-POCD groups. Twenty-five randomly chosen blood samples obtained seven days after the surgery from each group were analyzed on a Bruker ultraFlexTM time of flight （TOF）/TOF mass spectrophotometer. The resulting peptide fingerprints were compared with those from the pre-surgery samples to identify differences in serum protein composition. The model designed to distinguish between a non-POCD group and a POCD group were established and validated. Three proteins with the most significant changes were selected for further characterization. Results Thirty-three cases were diagnosed as POCD. Using the Clinprotools software, 58 polypeptides were found to display differential expression （P 〈0.05）. Using a support vector algorithm method, seven differential peaks were isolated to establish a diagnostic model to distinguish POCD patients from normal individuals. The prediction rate and recognition rate were 96.89% and 100%, respectively. Validation of this model showed that the accuracy rates were 100% and 85% using samples from the POCD and non-POCD groups, respectively. Protein analysis also led to the identification of fibrinopeptide A （FPA） as a potential biomarker for POCD. Conclusions Arthroplastic surgery under isoflurane inhalation anesthesia causes differential serum protein expression in elderly patients. These differentially expressed proteins may contribute to the diagnosis of early POCD, which may provide a basis for identifying the underlying mechanism of POCD development.

Diagnostic application of serum proteomic patterns in early gastric cancer patients by SELDI-TOF-MS

Objective:Surface-enhanced laser desorption/ionization time-of-flight mass spectrometry(SELDI-TOF-MS) is one of the currently used techniques to identify biomarkers for cancers.This study was planned to make a proteomic analysis on the serum of stage I gastric cancer patients and establish a early diagnostic model for identifying stage I gastric cancer preliminarily.Methods:A total of 229 serum samples including 169 pathologically confirmed gastric cancer patients(stage I:n = 47;stage II:n = 39;stage III:n = 46;stage IV:n = 37) and 60 gastritis patients were analyzed by SELDI-TOF-MS Protein Chip array technology.The resulting SELDI-TOF-MS spectral data were analyzed using the Biomarker WizardTM and Biomarker Patterns software to find differential proteins and develop a classification tree for early gastric cancer.Results:Twelve proteins were significantly over expressed(P<0.05,Student t-test) in patients with gastric cancer compared to patients with gastritis.Among them,three protein masses with 2873,6121 and 7778 m/z was found to be differentially expressed solely in patients suffering from stage I gastric cancer.The three protein masses construct the decision tree which could effectively distinguish stage I gastric cancer samples from control samples,achieving a sensitivity and specificity of 89.36(42/47) and 97.32%(182/187),respectively.Conclusion:Serum Proteomic Patterns can be used for the quick diagnosis of stage I gastric cancer.SELDI-TOF-MS is a useful tool for the detection and identification of new protein markers in serum.

The Proteomic Research of the Cure of Experimental Diabetes Deafness by Granules of Eliminating Phlegm and Removing Blood Stasis

Objective: Observing the expression changes of serum proteome in model rats after intervention of the Granules of Eliminating Phlegm and Removing Blood Stasis (豁痰祛瘀颗粒 also known as GEPRB), screening out and identifying the differentially expressed proteins by mass spectrometry and bioinformatics analysis, discussing the molecular mechanism of control the Diabetes deafness by GEPRB. Methods: By use of proteomics technology, the serum protein serum proteome of the control group, model control group, Duxil and each observation group were observed for 2-DE gel pattern matching, and the difference in the relative content of 2 times was chosen for the differentially expressed proteins. Identification of differentially expressed proteins by MALDI-TOF MS/MS, the authors further analysis the phosphorylation, subcellular localization, interaction, direct regulation, and transmembrane of the differences proteins by the way of bioinformatics analysis. Sixty SPF level SD rats elected in diabetic rats model group (abbreviated as DM group) were be randomly divided into 5 groups based on random number sheet, namely model control group, positive drug control group (Du-ke-xi group) and Mai-tong-fang high, medium and low dose group respectively. In addition, set of normal control group. 10 rats in each group. Results: By Coomassie brilliant blue staining, identified 51 differential protein spots dug from 2-D gel by mass spectrometry, successfully identified 13 non-redundant proteins. Most of the identified proteins were secreted protein and belong to different protein families. There were about 12 proteins have the transmembrane region from the authors’ result, ten of them were plasma membrane proteins. Conclusion: It’s suggesting that 13 differential proteins is most likely the protein response to GEPRB in vivo, these proteins may play key role for the treatment of GEPRB to Diabetes deafness. The two highly differentially expressed proteins Apolipoprotein E (apoE) and C3 may be a potential drug target of GEPRB.