OBJECTIVE To investigate the ameliorative effect and mechanism of short-acting exenatide on diabetic cognitive dysfunction. METHODS Spontaneously diabetic db / db mice were randomly divided into model group （normal saline） and exenatide group （50 μg/kg）， with db / m mice as the normal control group （normal saline）， with 8 mice in each group. Mice in each group were subcutaneously injected with corresponding drugs or normal saline twice daily for 8 consecutive weeks. Body weight and fasting blood glucose were measured at a fixed time every week. Cognitive function was evaluated by Morris water maze test. The levels of oxidative st ress indicators [malondialdehyde （MDA）， superoxide dismutase （SOD）， glutathione （GSH） ] ， cyclic adenosine monophosphate （cAMP） and protein kinase A （PKA） were detected in hippocampus tissue of mice. The hippocampal neuronal HT22 cells of mice were divided into control group （25 mmol/L glucose）， high glucose group （125 mmol/L glucose）， high glucose+exenatide group （125 mmol/L glucose+20 nmol/L exenatide）， high glucose+exenatide+H89 （PKA inhibitor） group （125 mmol/L glucose+20 nmol/L exenatide+10 μmol/L H89）， and high glucose+H89 group （125 mmol/L glucose+10 μmol/L H89）. After 48 h of intervention with corresponding solutions/culture medium， the levels of oxidative stress indicators， cAMP and PKA， the activities of mitochondrial respiratory enzymes Ⅱ and Ⅳ， and the phosphorylation level of dynamin-related protein 1 （Drp1） were measured. RESULTS Animal experiments showed that compared with the normal control group， the model group exhibited significantly increased body weight， fasting blood glucose and MDA level in the hippocampus （ P ＜0.05）， as well as significantly prolonged escape latency （ P ＜0.05）； swimming speed significantly slowed down， the time spent in the target quadrant， the number of platform crossings， and the levels of SOD， GSH， cAMP and PKA in the hippocampus were significantly decreased （ P ＜0.05）. Compared with model group， all the above indicators （except for swimming speed） in the exenatide group were significantly reversed （ P ＜0.05）. Cell experiments showed that compared with high glucose group， the high glucose+exenatide group had significantly decreased MDA level （ P ＜0.05）， and significantly increased levels of SOD， GSH， cAMP and PKA， the activities of mitochondrial respiratory enzymes Ⅱ and Ⅳ， and phosphorylation level of Drp1 （ P ＜0.05）. Compared with high glucose+exenatide group， the above indicators in the high glucose+exenatide+H89 group were significantly reversed （ P ＜0.05）. CONCLUSIONS Short-acting exenatide can activate the cAMP/PKA pathway， promote Drp1 phosphorylation， and increase the activities of mitochondrial respiratory enzymes， thereby maintaining mitochondrial stability， reducing oxidative stress injury， and ultimately improving diabetic cognitive dysfunction.

Objective:To investigate the clinicopathological characteristics and genetic alterations of undifferentiated embryonal sarcoma of the liver (UESL).Methods:Three cases of UESL diagnosed in the Department of Pathology, the Third Affiliated Hospital of Sun Yat-sen University from 2020 to 2023 were retrospectively collected. The clinical, histomorphological, immunohistochemical, and genetic profiles were reviewed and analyzed.Results:The cohort comprised of three patients, including one male and two females, aged 7, 9, and 15 years, respectively. Tumor locations were in the right lobe of the liver in two cases, and in both the right and left lobes in one case. One case exhibited tumor rupture with hemorrhage. Gross examination revealed solid tumors in gray-red fleshy appearance, with areas of hemorrhage and necrosis. Microscopically, the tumor was composed of irregularly shaped spindle and polygonal cells arranged in bundles or sheets with varying density, scattered within a myxoid matrix containing giant tumor cells and eosinophilic globules. The tumor cells were positive for Vimentin, CD56, CD68, and bcl-2, with a Ki-67 index of 30%-80%. INI1 expression was retained, while p53 exhibited a mutant pattern. CKpan, CK7, CK19, EMA, HepPar-1, Arginase-1, AFP, CD34, S-100, Myogenin, and MyoD1 were negative. All three cases harbored TP53 missense mutations. Case 1 also showed MDM2 copy number amplification (class Ⅰ mutation), and case 2 exhibited a frameshift mutation in exon 10 of TSC2 (class Ⅱ mutation). Additionally, several class Ⅲ mutations were identified in all three cases. Germline testing for tumor-related genetic variants in case 2 revealed a missense mutation in exon 12 of DICER1, an in-frame insertion mutation in exon 8 of MSH2, and a missense mutation in exon 30 of TSC2.Conclusion:UESL is a rare malignant mesenchymal tumor of the liver, predominantly affecting children, with distinctive clinicopathological features and genetic alterations. TP53 mutations may play a key role in the pathogenesis of this tumor.

Echinocandin B (ECB) is a key precursor of the antifungal drug anidulafungin. It is a secondary metabolite of Aspergillus nidulans, and its titer in fermentation is significantly affected by the ECB synthesis pathway and cell morphology. In this study, the key genes related to the transcription activation, hydroxylation, and cell morphology during ECB biosynthesis were investigated to increase the fermentation titer of ECB and to change the cell morphology of Aspergillus nidulans to reduce the viscosity of the fermentation broth. The results indicated that after overexpression of ecdB and ecdK, the ECB titer increased by 25.8% and 23.7%, respectively, compared with that of the wild-type strain, reaching (2 030.5±99.2) mg/L and (1 996.4±151.4) mg/L. However, the deletion of fksA associated with cell wall synthesis resulted in damage to the cell wall, affecting strain growth and product synthesis. The engineered strain overexpressing ecdB was fermented in a 50-L bioreactor, in which the ECB titer reached 2 234.5 mg/L. The findings laid a research foundation for the subsequent metabolic engineering of this strain.
Fermentation ; Aspergillus nidulans/genetics* ; Echinocandins/genetics* ; Bioreactors/microbiology* ; Fungal Proteins/biosynthesis* ; Metabolic Engineering

Objective:To investigate the clinicopathological characteristics and genetic alterations of undifferentiated embryonal sarcoma of the liver (UESL).Methods:Three cases of UESL diagnosed in the Department of Pathology, the Third Affiliated Hospital of Sun Yat-sen University from 2020 to 2023 were retrospectively collected. The clinical, histomorphological, immunohistochemical, and genetic profiles were reviewed and analyzed.Results:The cohort comprised of three patients, including one male and two females, aged 7, 9, and 15 years, respectively. Tumor locations were in the right lobe of the liver in two cases, and in both the right and left lobes in one case. One case exhibited tumor rupture with hemorrhage. Gross examination revealed solid tumors in gray-red fleshy appearance, with areas of hemorrhage and necrosis. Microscopically, the tumor was composed of irregularly shaped spindle and polygonal cells arranged in bundles or sheets with varying density, scattered within a myxoid matrix containing giant tumor cells and eosinophilic globules. The tumor cells were positive for Vimentin, CD56, CD68, and bcl-2, with a Ki-67 index of 30%-80%. INI1 expression was retained, while p53 exhibited a mutant pattern. CKpan, CK7, CK19, EMA, HepPar-1, Arginase-1, AFP, CD34, S-100, Myogenin, and MyoD1 were negative. All three cases harbored TP53 missense mutations. Case 1 also showed MDM2 copy number amplification (class Ⅰ mutation), and case 2 exhibited a frameshift mutation in exon 10 of TSC2 (class Ⅱ mutation). Additionally, several class Ⅲ mutations were identified in all three cases. Germline testing for tumor-related genetic variants in case 2 revealed a missense mutation in exon 12 of DICER1, an in-frame insertion mutation in exon 8 of MSH2, and a missense mutation in exon 30 of TSC2.Conclusion:UESL is a rare malignant mesenchymal tumor of the liver, predominantly affecting children, with distinctive clinicopathological features and genetic alterations. TP53 mutations may play a key role in the pathogenesis of this tumor.

To explore the safety and efficacy of left atrial appendage (LAA) occlusion under the guidance of local anesthesia and modified transseptal puncture technology by coronary sinus assisted positioning in patients with nonvavular atrial fibrillation (NVAF). Methods: A total of 16 NVAF patients received local anesthesia and percutaneous LAmbre or Amplatzer cardiac plug occluder implantation. There were 12 males and the patients mean age was at (71.0±6.0) years with CHA2DS2-VASc score at (4.1±1.5); all patients had walfarin contradiction or with walfarin related side effect. Transseptal puncture was conducted by coronary sinus catheter as the anatomic location marker. Results: All 16 patients finished transseptal puncture and no relevant complication occurred. 15/16 (93.8%) patients had successful LAA occlusion, 1 patient was abandoned because of LAA anatomic structure variation. The mean operative time was (65.0±23.0) min and the mean X-ray exposure time was (12.0±3.0) min. The mean diameter of occluder was (32.5±6.0)mm. Conclusion: LAA occlusion was safe and effective with local anesthesia and modified transseptal puncture technology by coronary sinus assisted positioning in relevant patients.

Objective To evaluate the efficacy and safety of biliary stent loaded with 125I seeds in treatment of hilar cholangiocarcinoma with malignant obstructive jaundice.Methods Totally 43 patients with malignant obstructive jaundice caused by cholangiocarcinoma were included.All the patients underwent percutaneous transhepatic puncture of the left and right side branch of the bile duct.In the hilar stenosis,the biliary stent with 125I seeds were implanted,and the biliary drainage tube had been kept in 3 to 5 days after procedures.The drainage tube was removed and the puncture road was closed after the patency of stents were confirmed by cholangiography.The changes of liver function before and after procedures were recorded,and the survival time was observed.Results Five biliary stents loaded with 125I seeds were implanted in type I (n=5),36 in type Ⅱ (n=18),8 in type Ⅲ (n=4) and 25 in type Ⅳ (n=16).The serum total bilirubin and direct bilirubin of patients before procedures were (145.54 ± 65.35) μmol/L and (124.73 ± 35.04) μmol/L,respectively,and (65.91±29.43)μmol/L and (35.50±15.12)μmol/L respectively after procedures.Compared with preoperative,the total bilirubin,direct bilirubin,alanine aminotransferase,aspartate aminotransferase,alkaline phosphatase,C-reactive protein and gamma glutamic transaminase decreased significantly (all P＜0.05).The lactate dehydrogenase had no significant difference before and after operation (P=1.050).The median survival time was 13 months (3.0 to 22.5 months).The serious complications such as biliary puncture,pancreatitis,severe biliary tract infection or biliary bleeding were not occurred.Conclusion Biliary stent loaded with 125 I seeds is an effective therapy to alleviate symptoms of jaundice and prolong the survival time of patients with malignant obstructive jaundice caused by hilar cholangiocarcinoma.