ObjectiveTo investigate the changes of fibrinogen and classical markers of collagen metabolism [carboxy-terminal propeptide of type Ⅰ procollagen (PICP) and carboxy-terminal cross-linked peptide of type Ⅰ collagen (ICTP)] in peripheral blood and pericardial drainage after coronary artery bypass grafting (CABG) and/or heart valve replacement (VR), and to evaluate their relationship with postoperative atrial fibrillation (POAF) after cardiac surgery. MethodsPatients who underwent CABG and/or VR in the Heart Center of Beijing Chao-Yang Hospital from March to June 2021 were included. Peripheral blood and pericardial drainage fluid samples were collected before surgery and at 0 h, 6 h, 24 h and 48 h after surgery to detect PICP, ICTP and fibrinogen levels, and preoperative, intraoperative and postoperative confounding factors were also collected. PICP, ICTP and fibrinogen levels were measured by enzyme-linked immunosorbent assay (ELISA). ResultsA total of 26 patients with 125 blood samples and 78 drainage samples were collected. There were 18 males and 8 females with an average age of 64.04±7.27 years. The incidence rate of POAF was 34.6%. Among the factors, the fibrinogen level in pericardial drainage showed two peaks within 48 h after operation (0 hand 24 h after operation) in the POAF group, while it showed a continuous downward trend in the sinus rhythm (SR) group, and the change trend of fibrinogen in pericardial drainage was significantly different over time between the two groups (P=0.022). Fibrinogen in blood, PICP and ICTP in blood and drainage showed an overall decreasing trend, and their trends over time were not significantly different between the two groups of patients (P>0.05). Univariate analysis showed that fibrinogen at 24 h and 48 h after pericardial drainage, fibrinogen in preoperative blood, PICP immediately after surgery and right atrial long axis diameter were significantly higher or longer in the POAF group than those in the SR group. Multiple regression showed that fibrinogen≥11.47 ng/mL in pericardial drainage 24 h after surgery (OR=14.911, 95%CI 1.371-162.122, P=0.026), right atrial long axis diameter≥46 mm (OR=10.801, 95%CI 1.011-115.391, P=0.049) were independent predictors of POAF. ConclusionThis study finds the regularity of changes in fibrinogen and collagen metabolic markers after CABG and/or VR surgery, and to find that fibrinogen in pericardial drainage 24 h after surgery is a potential novel and predictive factor for POAF. The results provide a new idea for exploring the mechanism of POAF, and provide a research basis for the accurate prediction and prevention of clinical POAF.
Objective To observe the biocompatibil ity of self-assembled FGL peptide nano-fibers scaffold with neural stem cells (NSCs). Methods FGL peptide-amphiphile (FGL-PA) was synthesized by sol id-phase peptide synthesistechnique and thereafter It was analyzed and determined by high-performance l iquid chromatography (HPLC) and massspectrometry (MS). The diluted hydrochloric acid was added into FGL-PA solution to reduce the pH value and accordinglyinduce self-assembly. The morphological features of the assembled material were studied by transmission electron microscope (TEM). NSCs were cultured and different concentrations of FGL-PA assembled material were added with the terminal concentrations of 0, 50, 100, 200, 400 mg/L, respectively. CCK-8 kit was used to test the effect of FGL assembled material on prol iferation of NSCs. NSCs were added into differentiation mediums (control group: DMEM/F12 medium containing 2% B27 supplement and 10% FBS; experimental group: DMEM/F12 medium containing 2% B27 supplement, 10% FBS and 100 mg/L FGL-PA, respectively). Immunofluorescence was appl ied to test the effect of FGL-PA assembled material on differentiation of NSCs. Results FGL-PA could be self-assembled to form a gel. TEM showed the self-assembled gel was nano-fibers with diameter of 10-20 nm and length of hundreds nanometers. After NSCs were incubated for 48 hours with different concentrations of FGL-PA assembled material, the result of CCK-8 assay showed that FGL-PA with concentrations of 50, 100 or 200 mg/L could promote the prol iferation of NSCs and absorbance of them was increased (P lt; 0.05). Immunofluorescence analysis notified that the differentiation ratio of neurons from NSCs in control group and experimental group were 46.35% ± 1.27% and 72.85% ± 1.35%, respectively, when NSCs were induced to differentiation for 14 days, showing significant difference between 2 groups (P lt; 0.05). Conclusion FGL-PA can self-assemble to nano-fiber gel, which has good biocompatibil ity and neural bioactivity.
Objectives To summarize the regulation of glucagon-like peptide-1（GLP-1） level by metabolism of gastrointestinal nutrients. Methods Domestic and international publications online involving regulation of GLP-1 level by metabolism of gastrointestinal nutrients in recent years were collected and reviewed. Results GLP-1 influenced insulin secretion and sensitivity， and played a leading role in recovery of glucose metabolism. Metabolism of gastrointestinal nutrients regulated GLP-1 level. Studies had shown that GLP-1 was a candidate mediator of the effects of gastric bypass （GBP） for type 2 diabetes mellitus（T2DM）. Conclusions It plays an important role in anti-T2DM effects of GBP that metabolism of gastrointestinal nutrients regulated GLP-1 level. The corresponding studies can provide a novel clinical field to treat T2DM.
Objective To obtain the polypeptides specifically binding to gastric cancer BGC823 cell from a Ph.D-12 TM phage display peptide library (PDPL), to search the markers of gastric cancer for early diagnosis and treatment. Methods The gastric cancer BGC823 cell was used as the antigen and the immortalized gastric epithelial GES cell was used as control for 3 rounds subtraction biopanning from PDPL at room temperature. The positive and specific binding clones were identified by cell enzyme-linked immunosorbent assay (ELISA) and immunochemistry staining. Those DNA sequences of identified clones were sequenced, polypeptides were marked by fluorescein FITC peptide tag, and polypeptides affinity and specificity of gastric cancer cells and tissues were identified. Results After 3 rounds of panning, 20 phage clones were identified by ELISA, one of which （GC-11） was specially binding to the BGC823. Cell and tissue immunofluorescence assay further presented a high affinity of fluorescein-labeled peptide FITC-GC-11 with BGC823 and gastric cancer tissue.Conclusion A peptide GC-11 which is specific binding to gastric cancer BGC823 cell and gastric cancer tissue has been selected from PDPL.
Objective To investigate the changes and clinical relationship of plasma adrenomedullin( ADM) , atrial natriuretic polypeptide( ANP) , and heart rate variability( HRV) in patients with obstructive sleep apnea-hypopnea syndrome ( OSAHS) . Methods Seventy-five inpatients with OSAHS were enrolled in this study. According to the apnea hypopnea index ( AHI) by polysomnography, the subjects were divided into a mild group, a moderate group, and a severe group. Meanwhile, HRV was screened bydynamic electrocardiogram in sleep laboratory. HRV parameters were obtained including LF ( low frequency power) , HF( high frequency power) , pNN50( percentage of NN50 in the total number of N-N intervals) ,SDNN( standard deviation of the N-N intervals) , rMSSD( square root of the mean squared differences of successive N-N intervals ) . Plasma levels of ADM/ANP were measured by radioimmunoassay. Results The levels of SDNN ( P lt;0. 05) , rMSSD, pNN50, LF ( P lt; 0. 05) and HF were gradually reduced, and the levels of ADM ( P lt;0. 05) and ANP ( P lt; 0. 05) were increased with increasing severity of OSAHS. Linear correlation analysis demonstrated that SDNN was negatively correlated with ADM( r = - 0. 423, P lt;0. 05)and ANP( r = - 0. 452, P lt; 0. 05) , and LF was also negatively correlated with ADM( r = - 0. 348, P lt;0. 05) . Conclusion Lower HRV is associated with more sever OSAHS, and it may be modulated neurohumorally by ADM and ANP.
Objective We investigated the effect of supplementation with alanyl-glutamine dipeptide on insulin resistance and outcome in patients with chronic obstructive pulmonary disease (COPD) and respiratory failure. Methods A prospective, randomized, open and controlled trial was conducted. Patients with COPD and respiratory failure were recruited between Jan 2005 to Feb 2006 and randomly assigned to a trial group (n=14) with glutamine dipeptide supplmented parenteral nutrition and a control group (n=16) with isocaloric, isonitrogenic parenteral nutrition. On the third day and fifth day of nutrition treatment, blood glucose was clamped at level of 4.4 to 6.1 mmol/L by intravenously bumped insulin. Blood gas, blood glucose level, insulin dosage were recorded everyday. The outcomes were mortality, length of stay (LOS) in hospital and in ICU, mechanical ventilation times and the costs of ICU and hospital.Results Thirty patients successfully completed the trial. There was no difference in blood gas between two groups, but PaO2 increased gradually. Compared with control group, blood glucose level had trend to decrease in trial group. The average insul in consumption decreased significantly in trial group on the fifth day. There was no statistical difference between two groups in mortality, length of stay in hospital and the costs of hospital. But compared with control group, length of stay in ICU and mechanical ventilation days had trend to decrease in trial group. Conclusion Alanyl-glutamine dipeptide do not improve pulmonary function of patients with COPD and respiratory failure. However, alanyl-glutamine dipeptide attenuated insul in resistance and stabilized blood glucose. This trial does not confirm alanyl-glutamine di peptide can improve outcome in critically ill patients with COPD and respiratory failure between two groups in mortality at the end of 30 days, length of stay in hospital and the costs of hospital. But the length of stay in ICU and the duration of mechanical ventilation does decrease, but not significantly, in the trial group.
Objective To observe whether Cyclo-RGDfK (Arg-Gly-Asp-D-Phe-Lys) could enhance the adhesion of myofibroblast to decellularized scaffolds and upregulate the expression of Integrin αVβ3 gene. Methods Myofibroblast from the rat thoracic aorta was acquired by primary cell culture. The expression of Vimentin and α-smooth muscle actin(α-SMA) has been detected by immunoflurescent labeling. Decellularized valves have been randomly divided into three groups (each n=7). Group A (blank control): valves do not receive any pretreatment; Group B: valves reacted with linking agent NEthylN(3dimethylaminopropyl)carbodiimide hydrochloride (EDC) for 36 hours before being seeded; Experimental group: Cyclo-RGD peptide has been covalently immobilized onto the surface of scaffolds by linking agent EDC. The fifth generation of myofibroblast has been planted on the scaffolds of each group. The adhesion of myofibroblast to the scaffolds was evaluated by HE staining and electron scanning microscope. The expression of Integrin αVβ3 was quantified by halfquantitative reverse transcriptionpolymerase china reaction (RT-PCR). Results We can see that myofibroblast has exhibited b positive staining for Vimentin and α-SMA. Besides, it has been shown that the expression of Integrin αVβ3 was much higher in the experimental group than that of the group A and group B(Plt;0.05). There was no statistically difference in group A and group B (P=0.900). Conclusion RGD pretreatment does enhance the adhesive efficiency of seeding cells to the scaffolds and this effect may be related to the upregulation of Integrin αVβ3.
Objective To observe the effect of pilose antler polypeptides(PAP)on the apoptosis of rabbit marrow mesenchymal stem cells (MSCs) differentiated into chondrogenic phenotype by interleukin 1β (IL-1β) so as to optimize the seeding cells in cartilage tissue engineering. Methods The MSCs were separated from the nucleated cells fraction of autologus bone marrow by density gradient centrifuge and cultured in vitro. The MSCs were induced into chondrogenic phenotype by transforming growth factor β1(TGF-β1) and basic fibroblast growth factor(bFGF). According to different medias, the MSCs were randomly divided into four groups: group A as black control group, group B(100 ng IL-1β)，group C(10 μg/ml PAP+100 ng IL-1β) and group D(100 ng/ml TGF-β1 +100 ng IL-1β). The samples were harvested and observed by morphology, flow cytometry analysis, RT-PCR and ELISA at 24, 48 and 72 hours. Results The intranuclear chromatin agglutinated into lump and located under nulear membranes which changed into irregular shapeat 24 hours. The intranuclear chromatin agglutinated intensifily at 48 hours. Then the nucear fragments agglutinated into apoptosic corpuscles at 72 hours in group B. The structure change of cells in groups C and D was later than that in group B, and the number of cells changed shape was fewer than that in group B. The structure change of cells in group A was not significant. The apoptosic rate of cells, the mRNA expression of Caspase-3 and the enzymatic activity of Caspase-3 gradually increased in group B, and there were significant differences compared with groups A,C and D(Plt;0.01). Conclusion Caspase-3 is involved in aoptosis of the MSCs differentiated into chondrogenic phenotype cultured in vitro. PAP could prevent from or reverse apoptosis of these MSCs by decreasing the expression of Caspase-3 and inhibiting the activity of Caspase-3.
Objective To evaluate the effects of the polypeptide growth factors on the periodontal ligament cell(PDLC) based on a comprehensive review onthe literature concerned. Methods The recent literature related to the effects of the polypeptide growth factors on the PDLC were extensivelyand comprehensively reviewed and a corresponding evaluation was made. Results The proliferation and the multidirectional differentiation of thePDLC were found to be the basis for the regeneration of the periodontal tissues. The effects of the polypeptide growth factors on the function of the PDLC became a hot issue of the research on the regeneration of the periodontal tissues. The polypeptide growth factors were found to play an important role in the migration, growth, proliferation, differentiation, and synthesis of protein and matrixof the PDLC. Conclusion The polypeptide growth factors can beused in the periodontal regeneration treatment, but a further research is stillrequired to improve this kind of treatment.
Abstract： Objective To investigate the influence of vasoactive intestinal peptide （VIP) on the sling fibers and the clasp fibers of the lower esophageal sphincter （LES） and the difference， and explore whether VIP belongs to a nonadrenergic and noncholinergic （NANC） neurotransmitter. Methods Thirty LES specimens were obtained from 30 patients with high-position carcinoma of the middle thoracic esophagus who underwent esophagectomy from March to August 2010 in Fourth Affiliated Hospital of Hebei Medical University. There were 14 male patients and 16 female patients with their average age of 58.0±6.1 years. The clasp fibers and sling fibers were isolated and suspended in perfusion. Exogenous VIP was added to the two kinds of strips to draw a concentration-effect curve. Electric field stimulation （EFS） or exogenous VIP was applied to clasp fibers and sling fibers， and the influence of VIP （10-28） on LES was compared. Results ExogenousVIP in different concentration caused concentration-dependent relaxation of the sling fibers and clasp fibers of LES in vitro. There was statistical difference in relaxation between the sling fibers and clasp fibers under same VIP concentration （P＜0.05）， and the relaxation of sling fibers was more significant than that of clasp fibers. VIP （10-28） transiently inhibited the relaxationof the sling fibers and clasp fibers caused by exogenous VIP. VIP （10-28） also transiently inhibited the relaxation of the sling fibers and clasp fibers after the activation of EFS. Conclusion The relaxation of sling fibers and clasp fibers induced by EFS is related to VIP. VIP is a kind of NANC neurotransmitter in human LES.