BACKGROUND: Acidic peptide is the tripeptide composed of 3 glutamic acids, which cannot bring excitatory nerve signal transmission into playlike single glutamic acid through presynaptic release and integration withpostsynaptic NMDA receptor directly as excitable neurotransmitter. It is quite possible that acidic peptide plays its actions by integrating with multiple metabolic glutamic acidic receptors so as to promote neuron proliferation or release nerve growth factor (NGF). OBJECTIVE: To probe into whether acidic peptide induces changes in learning and memory of model rats with Alzheimer disease (AD).DESIGN: Randomized controlled single experiment was designed.SETTING: Teaching-Research Room of Biochemistry and Molecular Biology of Basic Medical College of Zhengzhou University.MATERIALS: The experiment was performed in 2nd Research Room and Experimental Animal Room of Teaching-Research Room of Biochemistry and Molecular Biology of Basic Medical College of Zhengzhou University.Totally 100 SD male rats were selected and some of them were excluded due to retarded response in step down test. Totally 84 rats were included in the experiment and randomized into 7 groups, named normal control,model group, physiological saline group (PS group), piracetam group, acidic peptide groups of 60, 30 and 15 mg/kg, 12 rats in each group. Acidic peptide is a new small molecular peptide separated from bovine brain in this research team and is tripeptide composed of three glutamic acids.METHODS: Except normal control, in the rest groups, after 1 week routine breeding, cerebral stereotactic microinjection was used to inject 5 μg ibotenic acid in hippocampus of rats to destroy bilateral Meynert's basal ganglia to establish AD model. In normal control and model group, no medication was applied. In PS group, physiological saline was used for gastric perfusion. In piracetam group, piracetam of 0.3 g/kg was used for gastric perfusion and in acidic peptide groups of 15, 30 and 60 mg/kg,acidic peptide of 60, 30 and 15 mg/kg was applied for gastric perfusion successively, continuously for 20 days, once per day, 2 mL/time. On the expiration of gastric perfusion, learning and memory of rats were examined with step down test in every group. The animal was placed on the safe table on step down platform to adapt to the environment for 3 minutes, afterwards, 36 V electric current was given. Error response was recorded if the animal jumped to the copper railings after electric shock and correct response was recorded if the animal jumped back the safe area. Step-up latent phase and frequency of correct response were recorded in 3 minutes.MAIN OUTCOME MEASURES: Comparison of learning and memory of rats in every group. RESULTS: Totally 84 rats were all included in the result analysis. ①Comparison of learning in every group: Compared with model group, stepup latent phase was shortened remarkably in every acidic peptide group[(102.03±5.33), (71.77±4.38), (68.28±9.53), (69.13±8.79) s, P ＜ 0.01] and the frequency of correct response was improved remarkably [(12.92±2.91),(16.17±2.79), (15.83±3.27), (16.33±2.53) times, P ＜ 0.01]. ② Comparison of memory in every group: Compared with model group, step-up latent phase was shortened remarkably in every acidic peptide group [(43.17±4.66),(29.78±4.48), (26.20±3.28), (22.09±4.43) s, P ＜ 0.01] and the frequency of correct response was improved remarkably [(15.67±2.15), (20.92±2.68),(20.83±2.29), (20.25±2.05) times, P ＜ 0.01].CONCLUSION: Acidic peptide can shorten remarkably the step-up latent phase of AD rats in step down test and improve the frequency of correct response. It is indicated that acidic peptide provides good intervention on learning and memory of rat model of Alzheimer disease.

BACKGROUND: It is pointed in some experiment that acidic peptide improves learning and memory of model rat with Alzheimer disease (AD) by inhibiting the synthesis of toxic compounds of nitric oxide (NO).OBJECTIVE: Animal model with Alzheimer disease was established to observe the changes in the levels of NO, nitric oxide synthase (NOS) and acetylcholinesterase (AChE) treated with acidic peptide of various dose concentration.DESIGN: Randomized control and single experiment.SETTING: Teaching-Research Room of Biochemistry and Molecular Biology of Basic Medical College of Zhengzhou University.MATERIALS: The experiment was performed in 2nd Research Room and Experimental Animal Room of Teaching-Research Room of Biochemistry and Molecular Biology of Basic Medical College of Zhengzhou University.Totally 100 SD male rats were selected and some of them were excluded due to retarded response in step down test. Totally 84 rats were included in the experiment and randomized into 7 groups, named normal control,model group, physiological saline group (PS group), Piracetam group, acidic peptide groups of 15, 30 and 60 mg/kg, 12 rats in each group. Acidic peptide was a new small molecular peptide separated from bovine brain and is tripeptide composed of three glutamic acids.METHODS: Except normal control, in the rest groups, after 1 week routine breeding, cerebral stereotactic microinjection was used to inject 5 μg ibotenic acid in hippocampus of rats to destroy bilateral Meynert's nucleus basalis to establish AD model. In normal control and model group, no medication was applied. In PS group, physiological saline was used for gastric perfusion. In piracetam group, piracetam of 0.3 g/kg was used for gastric perfusion and in acidic peptide groupsof 15, 30 and 60 mg/kg,acidic peptide of 15, 30 and 60 mg/kg was applied for gastric perfusion successively, continuously for 20 days, once per day, 2 mL/time. On the expiration of gastric perfusion, the rats were sacrificed after anesthetized and the brain was collected on ice plate to prepare tissue homogenate. After centrifugated at 1 000 r/minute, 4℃ for 10 minutes, the supernatant was collected to assay the levels of NO, NOS and AChE with NO, NOS and AChE kits successively.MAIN OUTCOME MEASURES: Levels of NO, NOS and AChE in brain of rat in each groupRESULTS: Totally 84 rats were employed in the experiment and all entered result analysis. Comparison of levels of NO, NOS and AChE in rat brain of each group: compared with model group, NO levels in acidic peptide groups of 15, 30 and 60 mg/kg were reduced remarkably[(1.95±0.20), (1.39±0.10), (1.25±0.07), (1.00±0.04) mmoL/kg, P ＜ 0.05],NOS levels were reduced remarkably [(4.53±0.18), (3.39±0.09), (3.10±0.06),(2.97±0.06) μmol/kg, P ＜ 0.05] and AChE did not change remarkably[(0.67±0.12), (0.71±0.11), (0.72±0.08), (0.72±0.07) mmol/L, P ＞ 0.05].CONCLUSION: Acidic peptide reduces significantly the synthesis of NO and NOS in brain of AD rat, but it dose not affect AChE activity remarkably. It is suggested that acidic peptide improves learning and memory of rat with Alzheimer disease probably by inhibiting the synthesis of toxic compound of NO or its toxicity.

Objective:To compare the patient-reported outcomes and short-term clinical outcomes between robotic-assisted and laparoscopic-assisted radical gastrectomy for locally advanced gastric cancer.Methods:This single-center prospective randomized controlled trial was conducted in the Department of Gastrointestinal Surgery, Affiliated Hospital of Qingdao University from October 2020 to August 2022. Patients with locally advanced gastric cancer who were to undergo radical gastrectomy were selected and randomly divided into two groups according to 1∶1, and received robotic surgery and laparoscopic surgery, respectively. Patient-reported outcomes and short-term clinical outcomes (including postoperative complications, surgical quality and postoperative short-term recovery) were compared between the two groups by independent sample t test, Mann-Whitney U test, repeated ANOVA, generalized estimating equation, χ2 test and Fisher′s exact test. Results:A total of 237 patients were enrolled for modified intention-to-treat analysis (120 patients in the robotic group, 117 patients in the laparoscopic group). There were 180 males and 59 females, aged (63.0±10.2) years (range: 30 to 85 years). The incidence of postoperative complications was similar between the robotic group and laparoscopic group (16.7% (20/120) vs. 15.4% (18/117), χ2=0.072, P=0.788). The robotic group had higher patient-reported outcomes scores in general health status, emotional, and social domains compared to the laparoscopic group, differences in time effect, intervention effect, and interaction effect were statistically significant (general health status: χ2 value were 275.68, 3.91, 6.38, P value were <0.01, 0.048, 0.041; emotional: χ2 value were 77.79, 6.04, 6.15, P value were <0.01, 0.014, 0.046; social: χ2 value were 148.00, 7.57, 5.98, P value were <0.01, 0.006, 0.048). However, the financial burden of the robotic group was higher, the differences in time effect, intervention effect and interaction effect were statistically significant ( χ2 value were 156.24, 4.08, 36.56, P value were <0.01, 0.043,<0.01). Conclusion:Compared to the laparoscopic group, the robotic group could more effectively relieve postoperative negative emotions and improve recovery of social function in patients.

Objective:To compare the patient-reported outcomes and short-term clinical outcomes between robotic-assisted and laparoscopic-assisted radical gastrectomy for locally advanced gastric cancer.Methods:This single-center prospective randomized controlled trial was conducted in the Department of Gastrointestinal Surgery, Affiliated Hospital of Qingdao University from October 2020 to August 2022. Patients with locally advanced gastric cancer who were to undergo radical gastrectomy were selected and randomly divided into two groups according to 1∶1, and received robotic surgery and laparoscopic surgery, respectively. Patient-reported outcomes and short-term clinical outcomes (including postoperative complications, surgical quality and postoperative short-term recovery) were compared between the two groups by independent sample t test, Mann-Whitney U test, repeated ANOVA, generalized estimating equation, χ2 test and Fisher′s exact test. Results:A total of 237 patients were enrolled for modified intention-to-treat analysis (120 patients in the robotic group, 117 patients in the laparoscopic group). There were 180 males and 59 females, aged (63.0±10.2) years (range: 30 to 85 years). The incidence of postoperative complications was similar between the robotic group and laparoscopic group (16.7% (20/120) vs. 15.4% (18/117), χ2=0.072, P=0.788). The robotic group had higher patient-reported outcomes scores in general health status, emotional, and social domains compared to the laparoscopic group, differences in time effect, intervention effect, and interaction effect were statistically significant (general health status: χ2 value were 275.68, 3.91, 6.38, P value were <0.01, 0.048, 0.041; emotional: χ2 value were 77.79, 6.04, 6.15, P value were <0.01, 0.014, 0.046; social: χ2 value were 148.00, 7.57, 5.98, P value were <0.01, 0.006, 0.048). However, the financial burden of the robotic group was higher, the differences in time effect, intervention effect and interaction effect were statistically significant ( χ2 value were 156.24, 4.08, 36.56, P value were <0.01, 0.043,<0.01). Conclusion:Compared to the laparoscopic group, the robotic group could more effectively relieve postoperative negative emotions and improve recovery of social function in patients.