Objective: To compare quality control (relative purity and specific activity) and process control [plasminogen (Pg) antigen recovery and potency recovery] indexes of samples before and after adding the Q chromatography step to the full chromatography process of human Pg, thereby determining whether the addition of this step could improve Pg recovery by affinity chromatography. Methods: A Q chromatography step was added before the Pg affinity chromatography in the original Pg chromatography process. The loading solution, flow through solution and eluate of Q chromatography and Pg affinity chromatography were collected. The potency of coagulation factor Ⅱ (FⅡ), Ⅶ (FⅦ), Ⅷ (FⅧ), Ⅸ (FⅨ), and Ⅹ(FⅩ) were detected by the coagulation method, the total protein content was detected by the BCA method, and the Pg potency was detected by the chromogenic substrate method. The content of specific plasma proteins was detected by immunoturbidimetry, the potency recovery of coagulation factors was calculated, and the flow direction of coagulation factors was analyzed. The recovery of different plasma protein antigens were calculated, and the distribution of impurity proteins was analyzed. The relative purity and specific activity of Pg, antigen content, and potency recovery in the target fractions were calculated and compared with the original process indicators, so as to determine the effect of adding Q chromatography on the original process. Furthermore, the reproducibility after process modification was assessed. Results: 100% of FⅡ, FⅩ, and FⅨ, 87.81% of FⅧ, and 40.44% of FⅦ in filtered plasma were removed by Q chromatography. The residual FⅦ (53.26%) and FⅧ (13.30%) in Q flow-through fraction were completely removed by Pg affinity chromatography. In both the original process (without Q-chromatography) and the modified process (with Q-chromatography), non-target plasma proteins mainly existed in the flow-through fraction of Pg affinity chromatography. The antigen recovery of IgM, ceruloplasmin (CER), and fibronectin (FNC) in Q-chromatography flow-through fraction were reduced. In contrast, antigen recovery of other plasma proteins [IgG, IgA, Pg, albumin (AlB), alpha-1-antitrypsin (AAT), and fibrinogen (Fg)] were all >90%, which were consistent with the protein composition and proportion in the original affinity chromatography loading solution. Compared with the recovery rate of Pg antigen in the original process (74.4%), the total recovery of Pg antigen in the modified process was significantly increased (89.97%). Compared with the recovery of IgG (97.48%) and Fg (95.32%) in the Pg affinity flows-through fraction of the original process, the modified process resulted in a slight reduction in the recovery of IgG (94.60%), while the recovery of Fg was not affected (95.05%). The potency recovery rate, specific activity, and relative purity of Pg after Q chromatography were 99.3%, 0.016 U/mg, and 0.15%. These values were the same as those of Pg affinity chromatography loading solution by the original process, indicating that introduction of Q chromatography did not affect subsequent Pg affinity chromatography. Compared with the recovery of Pg antigen in three batches of the original process (66.49±1.02)%, the recovery of Pg antigen in the affinity chromatography eluent of the modified process [five batches; (77.43±4.43)%] was significantly improved. Furthermore, the potency recovery was (86.80±4.28)%, the relative purity was (81.99±1.25)%, the specific activity was (8.679±1.073)U/mg, and the process was reproducible. Conclusion: The addition of Q chromatography could improve the recovery of Pg affinity chromatography in the full chromatography process.

Objective:To explore medical students'cognition,current status,and demands regarding practical skills training in a medical college under the background of new medical science.Methods:A cross-sectional survey was conducted among medical undergraduates from Year 1 to Year 5 in a medical college.A self-designed scale was used to investigate the cognition,current status,and demands related to new medical education concepts.Pearson correlation analysis was used to analyze the relationship between satisfaction with practical teaching facilities and variables including understanding of new medical education,curriculum design,and proportion of practical teaching.Multiple linear regression was conducted to investigate the factors influencing satisfaction.Results:Among 1 253 participants,70.71%acquired new medical science information through online media,while 52.99%learned about it via school courses.Over 80%endorsed"whole-cycle health management"(preventive care before disease onset 91.94%,disease treatment 81.72%,and post-illness rehabilitation 82.60%).Experimental courses(85.16%),clinical skills training(66.88%),and social practice(66.24%)were primary practical forms,but the participation rates of research practice(40.78%)and innovation/entrepreneurship practice(34.72%)was comparatively lower.The satisfaction with practical teaching was positively correlated with adequacy of faculty guidance(r=0.707)and curriculum rationality(r=0.522)(P＜0.01).The multiple linear regression analysis showed that faculty guidance(β=0.436)and the proportion of practical teaching(β=0.319)were the key predictors of satisfaction.Conclusion:Medical students'cognition of practical skills training,curriculum optimization,and adequacy of faculty guidance significantly influence satisfaction with practical teaching,with faculty guidance and rationality of practical process playing key roles.

Objective:To explore medical students'cognition,current status,and demands regarding practical skills training in a medical college under the background of new medical science.Methods:A cross-sectional survey was conducted among medical undergraduates from Year 1 to Year 5 in a medical college.A self-designed scale was used to investigate the cognition,current status,and demands related to new medical education concepts.Pearson correlation analysis was used to analyze the relationship between satisfaction with practical teaching facilities and variables including understanding of new medical education,curriculum design,and proportion of practical teaching.Multiple linear regression was conducted to investigate the factors influencing satisfaction.Results:Among 1 253 participants,70.71%acquired new medical science information through online media,while 52.99%learned about it via school courses.Over 80%endorsed"whole-cycle health management"(preventive care before disease onset 91.94%,disease treatment 81.72%,and post-illness rehabilitation 82.60%).Experimental courses(85.16%),clinical skills training(66.88%),and social practice(66.24%)were primary practical forms,but the participation rates of research practice(40.78%)and innovation/entrepreneurship practice(34.72%)was comparatively lower.The satisfaction with practical teaching was positively correlated with adequacy of faculty guidance(r=0.707)and curriculum rationality(r=0.522)(P＜0.01).The multiple linear regression analysis showed that faculty guidance(β=0.436)and the proportion of practical teaching(β=0.319)were the key predictors of satisfaction.Conclusion:Medical students'cognition of practical skills training,curriculum optimization,and adequacy of faculty guidance significantly influence satisfaction with practical teaching,with faculty guidance and rationality of practical process playing key roles.

Objective To analyze the current status and influencing factors of occupational burnout among medical staff in Dongguan City. Methods A total of 1 007 medical staff from eight hospitals in Dongguan City were selected as the study subjects using the stratified sampling method. The Maslach Burnout Inventory-Human Service Survey and Moral Injury Symptom Scale (Healthcare Professionals Edition) were used to assess occupational burnout and moral injury among these study subjects. Binary logistic regression analysis was conducted to identify the influencing factors of occupational burnout. Results The detection rate of occupational burnout among the medical staff was 46.2%, and the detection rate of moral injury was 48.1%. The result of binary logistic regression analysis showed that after controlling for confounding factors such as age, marriage status, educational level, religious belief, professional title, and hospital characteristics, male medical staff had a higher risk of occupational burnout than female staff (P<0.01). Medical staff with ≤10 years of work experience had a higher risk of occupational burnout than those with >10 years of work experience(P<0.01). Additionally, medical staff with moral injury had a higher risk of occupational burnout than those without moral injury (P<0.01). Conclusion Occupational burnout is relatively common among medical staff in Dongguan City and is influenced by factors such as gender, working years, moral injury, and others.

Objective To investigate the risk factors for the formation of infectious stones among residents in western Fujian Province and construct a nomogram model for preoperative prediction of the risk of infectious stones. Methods Clinical data of 204 patients who received treatment for urinary tract stones at Longyan People′s Hospital Affiliated to Xiamen Medical University from October 2021 to November 2023 were analyzed. All patients underwent stone composition analysis. Univariate and multivariate Logistic regression analysis were used to screen independent risk factors for infectious stones, construct a nomogram model for predicting the risk of infectious stones, and the discriminative power and accuracy of the model was evaluated. Results Based on the results of stone composition analysis, 204 patients were divided into infectious stone group(56 cases) and non-infectious stone group(148 cases). Univariate and multivariate Logistic regression analysis showed that female (OR=2.602, 95%CI, 0.766 to 8.842, P=0.039), diabetes (OR=9.751, 95%CI, 2.547 to 17.332, P=0.001), long diameter of stones (OR=1.123, 95%CI, 1.046 to 4.207, P=0.031), moderate to severe hydronephrosis (OR=4.173, 95%CI, 1.256 to 13.865, P=0.020), high urine pH value (OR=6.078, 95%CI, 1.922 to 19.216, P=0.002), and positive urine culture (OR=6.060, 95%CI, 1.398 to 16.262, P=0.016) were independent risk factors for infectious stones. A nomogram model for predicting the risk of infectious stones was constructed based on independent risk factors. The area under the curve of this model for predicting infectious stones was 0.860, which was significantly larger than the area under the curve predicted by gender, diabetes, stone long diameter, degree of hydronephrosis, urine pH value, and urine culture results (P < 0.05). The model was validated by 1 000 internal resampling, with an average absolute error of 1.8%, indicating a high consistency between the predicted risk of infectious stones and the actual situation. Conclusion Female, diabetes, long diameter of stones, moderate to severe hydronephrosis, high urine pH value, and positive urine culture are independent risk factors for infectious stones among residents in western Fujian Province. The nomogram model constructed based on these factors can predict the risk of infectious stones preoperatively with high predictive efficiency.

OBJECTIVE: To investigate the perioperative electrolyte imbalance in patients undergoing gastrointestinal surgery. METHODS: Retrospective case analysis was used in this study. Patients who underwent gastrointestinal surgery under general anesthesia at the Sixth Affiliated Hospital of Sun Yat-sen University from January to April 2018 were selected through electronic medical records system. Blood gas analysis during surgery must be carried out in the enrolled patients. Patients with excessive fluid infusion, critical conditions or patients who had been enrolled in other clinical trials were excluded. A total of 999 patients were enrolled. The preoperative, intraoperative and postoperative concentrations of serum sodium, potassium and calcium were collected by the last biochemical examination before surgery, arterial blood gas analysis within 1 h after anesthesia and another biochemical examination within 24 hours after surgery respectively. The type and incidence of electrolyte imbalance were then analyzed, and logistic regression analysis was used to investigate the risk factors. RESULTS: In the 999 patients, 683 cases were male (63.9%) and 361 cases were female(36.1%), with an average age of (56.9±14.6) years old. Fifty-eight patients (5.8%) underwent emergency surgery and 941 patients (94.2%) underwent elective surgery; Sixty-two patients were treated with laxatives at least 3 times and 115 patients were treated with enema at least 3 times before operation. The incidence of hypokalemia was 49.6%(496/999) intraoperatively and decreased to 15.2%(152/999) postoperatively. No hyperkalemia cases were found. The incidence of hypocalcemia was 53.8%(537/999) intraoperatively and increased to 79.7% (796/999) postoperatively. The incidence of hypokalemia in ileus patients was 33.3%(17/51) before surgery, which was higher than that in patients with colorectal cancer [12.3%(86/703)], patients with gastric cancer [7.8%(8/104)] and patients with other gastrointestinal diseases[10.6%(15/141)] (all P<0.05). Similarly, the preoperative and intraoperative incidence of hyponatremia in ileus patients were both 15.7%(8/51), which were higher than those in patients with colorectal cancer [3.0% (21/703) and 2.3% (16/703)] and patients with gastric cancer [2.9%(3/104) and 1.9%(2/104)]. The incidence of hypocalcemia in ileus patients was 31.4%(16/51) preoperatively, which were also higher than those in patients with colorectal cancer [7.4%(52/703)] and patients with gastric cancer [8.7%(9/104)] (all P<0.05). Logistic regression analysis showed that ileus and emergency surgery were risk factors for patients with preoperative electrolyte imbalance; preoperative electrolyte imbalance was a risk factor for intraoperative electrolyte imbalance; intraoperative electrolyte imbalance was a risk factor for postoperative electrolyte imbalance; preoperative electrolyte imbalance was a risk factor for postoperative imbalance of sodium and potassium. CONCLUSIONS The incidence of electrolyte imbalance is high in patients undergoing gastrointestinal surgery, especially hypocalcemia and hypokalemia. It is necessary to recognize the electrolyte abnormality timely and give active intervention and correction.
Adult ; Aged ; Digestive System Surgical Procedures ; Electrolytes ; Female ; Humans ; Hyponatremia ; Ileus ; Male ; Middle Aged ; Postoperative Complications ; prevention & control ; Retrospective Studies ; Risk Factors ; Water-Electrolyte Imbalance

Objective To evaluate the clinical values of acoustic radiation force impulse(ARFI) elastography for liver fibrosis on hepatopath patients.Methods ARFI elastography was prospectively performed on 99 patients prepared to undergo hepatic surgery to get a shear wave velocity(Vs) which was the representative of liver stiffness.The fibrosis stages,inflammation grades and steatosis grades were evaluated histologically after surgery.Values of Vs were compared with the histological results.Results Values of Vs with fibrosis stage 0-4 was (1.14 ± 0.22) m/s,(1.30 ± 0.22) m/s,(1.36 ± 0.38) m/s,(1.47 ± 0.37)m/s and (1.87 ± 0.08) m/s,respectively.A significant difference was observed among them (P ＜0.001).There was a certain correlation between Vs and fibrosis stage(r =0.541,P ＜0.001).Vs was a significant predictor of stage ≥3 fibrosis with an area under the ROC curve of 0.812,sensitivity 73.2％ and specificity 81.4％ when 1.40 m/s was the cutoff value (P ＜ 0.001).Values of Vs with inflammation grade 0-3 was (1.17 ± 0.16)m/s,(1.43 ± 0.36) m/s,(1.59 ± 0.53) m/s and (1.89 ± 0.59) m/s,respectively,which were significantly different (P ＜ 0.001).A certain correlation was observed between Vs and inflammation grade(r =0.383,P ＜0.001).Values of Vs with steatosis grade 0-4 was (1.61 ±0.42) m/s,(1.47±0.58) m/s,(1.56 ± 0.71)m/s,1.13 m/s and (0.94 ± 0.95) m/s.Obvious difference didn't exist between Vs and steatosis grade (P =0.286).Obvious correlation wasn't observed between them,either (r =-0.177,P =0.080).Conclusions ARFI elastography has a certain value for the evaluation of liver fibrosis,while inflammation grade may affect its performance.

BACKGROUND: Studies have demonstrated that intermittent high glucose can have a more severe impact on vascular endothelial function in comparison with persistent hyperglycemia.OBJECTIVE: To investigate the effect of intermittent high glucose on the proliferation and apoptosis of endothelial progenitor cells (EPCs) from human peripheral blood in vitro as well as the production of malondialdehyde (MDA) and antioxidant. METHODS: Total mononuclear cells were isolated from human peripheral blood by Ficoll density gradient centrifugation and then the cells were placed on fibronectin-coated culture dishes. After 7 days of culture, the adherent cells were identified as EPCs by laser scanning confocal microscope. The cells were synchronized and then stimulated with glucose 5.5 mmol/L (normal control group), 20 mmol/L (constant high glucose group), and 5.5/20 mmol/L (intermittent high glucose group, 5.5 and 20 mmol/L glucose culture solution was changed every 8 hours) for 72 hours. EPCs proliferation and apoptosis was measured by MTT assay and flow cytometry, respectively. The content of MDA and the activity of superoxide dismutase (SOD) in culture solution were detected with colorimetry.RESULTS AND CONCLUSION: After EPCs were exposed to constant high glucose (20 mmol/L) and intermittent high glucose (5.5/20 mmol/L) for 72 hours, proliferated cells were significantly reduced and the apoptosis rate was significantly increased compared with those exposed to normal glucose (P < 0.01). Furthermore, there was a significant increase in MDA contents as well as a significant reduce in SOD activities in the constant high glucose and intermittent high glucose group (P < 0.01), especially in the latter group. These findings indicated that both intermittent high glucose and constant glucose could inhibit the proliferation and promote the apoptosis of EPCs; however, intermittent high glucose appears to worsen the effects on EPCs. This is maybe due to the increased oxidative stress.

Objective To investigate the clinical significance of serum amyloid A protein in patients with chronic hepatitis C (HCV) infection. Methods Serum amyloid A (SAA) levels were detected by ELISA in 131 patients with HCV infection and 20 normal controls. The expression of SAA-mRNA in peripheral blood mononuclear cells (PBMC) was detected by RT-PCR from some blood samples of HCV patients and normal controls. Results The SAA levels in the patients with chronic HCV infection were markedly higher than those in normal controls (t = 17. 14, P < 0. 01 ). The expression of SAA-mRNA detected by RT-PCR was closely correlated with concentrations of SAA measured by ELISA ( r = 0.86, P <0.01 ). No correlation was found between SAA expression and serum HCV RNA titers, as well as between SAA and serum ALT in patients with chronic HCV infection. Conclusion SAA levels are increased in patients with chronic HCV infection, which is not correlated with HCV RNA titers and serum ALT levels.

BACKGROUND: The study of isolation, purification, culture, cell labeling, inducing factors, effects of gene transfection on cytobiology, cell carrier construction, and time window for back transplantation of cell compound pertaining to marrow stromal cells (MSCs) is still in its infancy. OBJECTIVE: To search for an in vitro culture method that can be simply and effectively obtained. DESIGN, TIME AND SETTING: The present cytological in vitro experiment was performed at the Beijing Institute of Genome, Chinese Academy of Sciences between June 2006 and July 2007. MATERIALS: Eight specific pathogen-free New Zealand rabbits, aged 6 weeks, were provided by the Laboratory Animal Center, Institute of Genetics and Development, Chinese Academy of Sciences. METHODS: Under sterile condition, 1 mL rabbit bone marrow was taken and diluted with D-Hanks solution. Following centrifugation and subsequent supernatant removal, bone marrow was re-suspended using dulbecco's modified eagle's medium (DMEM) for single cell suspension. Next, single cell suspension was dropped onto the liquid surface of equal-volume lymphocyte separation medium (density: 1.077). Subsequent to centrifugation, cloudlike mononuclear cell layer was collected and re-suspended with DMEM containing 20% fetal bovine serum. The cells were inoculated at lxl0/cm2 and purified by adherent method. When 70%-80% of flask bottom was covered, cell digestion and passage was performed.MAIN OUTCOME MEASURES: Cell growth was observed with an operating microscope. Surviving cells were counted by Trypan blue viability test. Cell identification was performed by hematoxylin-eosin staining. Through the use of 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay, cell viability was detected to observe the cellular resuscitation of the cultured cells following cryopreservation. RESULTS: Twenty-four hours after inoculation, cells began to adhere to the wall, exhibiting short shuttle- or triangle-shaped appearance with different sizes of cellular processes. Three days later, adherent cells began to divide, and cell clusters could be found in some areas; One week later, most of cells exhibited scattered fibroblast-like growth; After passage, cells were evenly distributed with long shuttle-shaped appearance and arranged orderly. Following 3 passages, there wound be 5×106-1×107 adherent cells in 1 mL MSC suspension. Approximately 90% of MSCs survived and identified as mononuclear cells. Cells vigorously grew at days 1-6 after inoculation and reached a peak level at day 8, followed by a viability decline. After 56 days of resuscitation, frozen cells displayed a good and rapid growth. CONCLUSION: Highly purified MSCs can be acquired by gradient centrifugation of lymphocyte separation medium. Enough seeded cells can be obtained by in vitro culture and the cellular viability does not change after frozen preservation and resuscitation.