Endo-beta-N-acetylglucosaminidase (ENGase) is widely distributed in various organisms. The first reported ENGase activity was detected in Diplococcus pneumoniae in 1971. The protein (Endo D) was purified and its peptide sequence was determined in 1974. Three ENGases (Endo F1-F3) were discovered in Flavobacterium meningosepticum from 1982 to 1993. After that, the activity was detected from different species of bacteria, yeast, fungal, plant, mice, human, etc. Multiple ENGases were detected in some species, such as Arabidopsis thaliana and Trichoderma atroviride. The first preliminary crystallographic analysis of ENGase was conducted in 1994. But to date, only a few ENGases structures have been obtained, and the structure of human ENGase is still missing. The currently identified ENGases were distributed in the GH18 or GH85 families in Carbohydrate-Active enZyme (CAZy) database. GH18 ENGase only has hydrolytic activity, but GH85 ENGase has both hydrolytic and transglycosylation activity. Although ENGases of the two families have similar (β/α)8-TIM barrel structures, the active sites are slightly different. ENGase is an effective tool for glycan detection andglycan editing. Biochemically, ENGase can specifically hydrolyze β‑1,4 glycosidic bond between the twoN-acetylglucosamines (GlcNAc) on core pentasaccharide presented on glycopeptides and/or glycoproteins. Different ENGases may have different substrate specificity. The hydrolysis products are oligosaccharide chains and a GlcNAc or glycopeptides or glycoproteins with a GlcNAc. Conditionally, it can use the two products to produce a new glycopeptides or glycoprotein. Although ENGase is a common presentation in cell, its biological function remains unclear. Accumulated evidences demonstrated that ENGase is a none essential gene for living and a key regulator for differentiation. No ENGase gene was detected in the genomes of Saccharomyces cerevisiae and three other yeast species. Its expression was extremely low in lung. As glycoproteins are not produced by prokaryotic cells, a role for nutrition and/or microbial-host interaction was predicted for bacterium produced enzymes. In the embryonic lethality phenotype of the Ngly1-deficient mice can be partially rescued by Engase knockout, suggesting down regulation of Engase might be a solution for stress induced adaptation. Potential impacts of ENGase regulation on health and disease were presented. Rabeprazole, a drug used for stomach pain as a proton inhibitor, was identified as an inhibitor for ENGase. ENGases have been applied in vitro to produce antibodies with a designated glycan. The two step reactions were achieved by a pair of ENGase dominated for hydrolysis of substrate glycoprotein and synthesis of new glycoprotein with a free glycan of designed structure, respectively. In addition, ENGase was also been used in cell surface glycan editing. New application scenarios and new detection methods for glycobiological engineering are quickly opened up by the two functions of ENGase, especially in antibody remodeling and antibody drug conjugates. The discovery, distribution, structure property, enzymatic characteristics and recent researches in topical model organisms of ENGase were reviewed in this paper. Possible biological functions and mechanisms of ENGase, including differentiation, digestion of glycoproteins for nutrition and stress responding were hypothesised. In addition, the role of ENGase in glycan editing and synthetic biology was discussed. We hope this paper may provide insights for ENGase research and lay a solid foundation for applied and translational glycomics.

Objective:To explore the clinical application of preimplantation genetic testing for monogenic disorders (PGT-M) in an unique case with Spinal muscular atrophy (SMA) type 2+ 0.Methods:A special SMA family presented at the Third Affiliated Hospital of Guangzhou Medical University on October 19, 2020 was selected as the study subject. Multiple ligation-dependent probe amplification (MLPA) and molecular tagging linkage analysis were carried out to identify the SMN1 genotype of the couple and their fetus. Subsequently, next-generation sequencing (NGS), molecular tagging linkage analysis, and chromosomal microarray analysis were employed to determine the haplotypes and validate the result of PGT-M on the 11 embryos derived for the couple. Results:The female partner was identified as a carrier of the rare SMN1[2+ 0] variant, and prenatal diagnosis confirmed the fetus to be affected by SMA. Ultimately, PGT-M has successfully selected four embryos free from the pathogenic SMN1 variants and X chromosome deletion. Conclusion:PGT-M can effectively prevent the transmission of rare genetic variants such as the SMA 2+ 0 subtype in the families. Above finding has provided guidance for genetic counseling and family planning for the couple.

Objective To investigate the risk factors for bronchopulmonary dysplasia(BPD)in twin preterm infants with a gestational age of<34 weeks,and to provide a basis for early identification of BPD in twin preterm infants in clinical practice.Methods A retrospective analysis was performed for the twin preterm infants with a gestational age of<34 weeks who were admitted to 22 hospitals nationwide from January 2018 to December 2020.According to their conditions,they were divided into group A(both twins had BPD),group B(only one twin had BPD),and group C(neither twin had BPD).The risk factors for BPD in twin preterm infants were analyzed.Further analysis was conducted on group B to investigate the postnatal risk factors for BPD within twins.Results A total of 904 pairs of twins with a gestational age of<34 weeks were included in this study.The multivariate logistic regression analysis showed that compared with group C,birth weight discordance of>25%between the twins was an independent risk factor for BPD in one of the twins(OR=3.370,95%CI:1.500-7.568,P<0.05),and high gestational age at birth was a protective factor against BPD(P<0.05).The conditional logistic regression analysis of group B showed that small-for-gestational-age(SGA)birth was an independent risk factor for BPD in individual twins(OR=5.017,95%CI:1.040-24.190,P<0.05).Conclusions The development of BPD in twin preterm infants is associated with gestational age,birth weight discordance between the twins,and SGA birth.

Spinal intradural (subdural and subarachnoid) hematoma following percutaneous kyphoplasty is an extremely rare complication. In this report, we described a case of 2 episodes of subarachnoid hemorrhage with delayed paralysis after kyphoplasty. A 73-year-old man underwent percutaneous kyphoplasty in our hospital an osteoporotic vertebral fracture at the T12 level. On the 55 h after kyphoplasty for T12 osteoporotic vertebral fracture, he developed paralysis of the lower limbs. An emergency posterior decompression from T8 to L2 was performed. And the subarachnoid hematomas were removed. Postoperatively, the neurological symptoms improved rapidly. However, 2 weeks after the operation, the patient experienced a setback with severe neurological decline (paraplegia with sensory and autonomic dysfunction). An emergency posterior decompression from T5 to L2 was performed. The subarachnoid hematomas were removed. This case reflects the cause and progression of spinal subdural hematoma. Previous literature has debated the best treatment approach for spinal subarachnoid hemorrhage, but the prognosis of patients is heavily dependent on precise symptom evaluation and localization.

Objectives: To construct a nomogram for prediction of intrahepatic cholangiocarcinoma (ICC) lymph node metastasis based on inflammation-related markers,and to conduct its clinical verification. Methods: Clinical and pathological data of 858 ICC patients who underwent radical resection were retrospectively collected at 10 domestic tertiary hospitals in China from January 2010 to December 2018. Among the 508 patients who underwent lymph node dissection,207 cases had complete variable clinical data for constructing the nomogram,including 84 males,123 females,109 patients≥60 years old,98 patients<60 years old and 69 patients were pathologically diagnosed with positive lymph nodes after surgery. Receiver operating characteristic curve was drawn to calculate the accuracy of preoperative imaging examinations to determine lymph node status,and the difference in overall survival time was compared by Log-rank test. Partial regression squares and statistically significant preoperative variables were screened by backward stepwise regression analysis. R software was applied to construct a nomogram,clinical decision curve and clinical influence curve,and Bootstrap method was used for internal verification. Moreover,retrospectively collecting clinical information of 107 ICC patients with intraoperative lymph node dissection admitted to 9 tertiary hospitals in China from January 2019 to June 2021 was for external verification to verify the accuracy of the nomogram. 80 patients with complete clinical data but without lymph node dissection were divided into lymph node metastasis high-risk group and low-risk group according to the score of the nomogram among the 858 patients. Log-rank test was used to compare the overall survival of patients with or without lymph node metastasis diagnosed by pathology. Results: The area under the curve of preoperative imaging examinations for lymph node status assessment of 440 patients was 0.615,with a false negative rate of 62.8% (113/180) and a false positive rate of 14.2% (37/260). The median survival time of 207 patients used to construct a nomogram with positive or negative postoperative pathological lymph node metastases was 18.5 months and 27.1 months,respectively (P<0.05). Five variables related to lymph node metastasis were screened out by backward stepwise regression analysis,which were combined calculi,neutrophil/lymphocyte ratio,albumin,liver capsule invasion and systemic immune inflammation index,according to which a nomogram was constructed with concordance index(C-index) of 0.737 (95%CI: 0.667 to 0.806). The C-index of external verification was 0.674 (95%CI:0.569 to 0.779). The calibration prediction curve was in good agreement with the reference curve. The results of the clinical decision curve showed that when the risk threshold of high lymph node metastasis in the nomogram was set to about 0.32,the maximum net benefit could be obtained by 0.11,and the cost/benefit ratio was 1∶2. The results of clinical influence curve showed that when the risk threshold of high lymph node metastasis in the nomogram was set to about 0.6,the probability of correctly predicting lymph node metastasis could reach more than 90%. There was no significant difference in overall survival time between patients with high/low risk of lymph node metastasis assessed by the nomogram and those with pathologically confirmed lymph node metastasis or without lymph node metastasis (Log-rank test:P=0.082 and 0.510,respectively). Conclusion: The prediction accuracy of preoperative nomogram for ICC lymph node metastasis based on inflammation-related markers is satisfactory,which can be used as a supplementary method for preoperative diagnosis of lymph node metastasis and is helpful for clinicians to make personalized decision of lymph node dissection for patients with ICC.

OBJECTIVE: To explore the carrier rate, genotype and phenotype of α-thalassemia fusion gene in Huadu district of Guangzhou, Guangdong province of China, and provide data reference for the prevention and control of thalassemia. METHODS: A total of 10 769 samples who were screened for thalassemia in Maternal and Child Health Hospital of Huadu District from July 2019 to November 2020 were analyzed retrospectively. Blood cell analysis and hemoglobin (Hb) electrophoresis were performed. Thalassemia genes were analyzed by gap-PCR and PCR-reverse dot blot hybridization (PCR-RDB). RESULTS: A total of 9 cases with α-thalassemia fusion gene were detected in 10 769 samples (0.08%). There were 7 cases with fusion gene heterozygote, 1 case with compound of α-thalassemia fusion gene and Hb G-Honolulu, 1 case with compound of α-thalassemia fusion gene and Hb QS. The MCV results of 4 samples of blood cell analysis were within the reference range, the Hb A2 value of 1 case was decreased, and there were no other abnormalities found. CONCLUSION The α-thalassemia fusion gene is common in Huadu district of Guangzhou, and heterozygotes are more common, and current screening methods easily lead to misdiagnosis.
Humans ; alpha-Thalassemia/genetics* ; Retrospective Studies ; beta-Thalassemia/genetics* ; Genotype ; Phenotype ; Heterozygote ; China ; Mutation

AIM: To evaluate the necessity of slit-lamp biomicroscopy(referred to here as “slit-lamp”)training from the student's perspective and reach a consensus on slit-lamp training in medical students during ophthalmology clerkship.METHODS: A controlled before-after clerkship study was performed on 117 students of the class of 2017 enrolled in clinical medicine at Sun Yat-sen University. All medical students underwent slit-lamp training during ophthalmology clerkship. We evaluated the students' cognition, perceived need and recommendations for slit-lamp teaching, using a self-completed questionnaire survey and compared the students' scores in these aspects before and after their ophthalmology clerkships. Additionally, the efficiency of slit-lamp training was evaluated by subjective student assessment after the ophthalmology clerkship. Each item was scored on a five-point Likert Scale. Statistical analysis was performed by IBM SPSS(Version 20.0; SPSS Inc., Chicago, IL, USA).RESULTS: A total of 116(99.1%)medical students completed the survey. The average score before clerkship was 19.99±3.03, which indicated a high level of cognition regarding slit-lamp utility; However, this score significantly increased to 22.97±2.37 after clerkship(P<0.001). The average score regarding perceived need was also higher for post-clerkship students than for pre-clerkship students(24.62±3.15 vs. 23.60±2.36, P=0.009). Moreover, 86.2% of post-clerkship students reported that hands-on slit-lamp practice could help promote clerkship quality. More than three-quarters of the surveyed students tended to agree that slit-lamp practice time should be increased(76.7% and 77.6% before and after clerkship, respectively).CONCLUSION: A hands-on approach to slit-lamp training is more favored by medical students in ophthalmology clerkships, and this training should be recommended in ophthalmology clerkships given its potential usefulness for improving clerkship quality.

BACKGROUND: Human umbilical cord mesenchymal stem cells (hUCMSCs) have emerged as promising therapy for immune and inflammatory diseases. However, how to maintain the activity and unique properties during cold storage and transportation is one of the key factors affecting the therapeutic efficiency of hUCMSCs. Schisandrin B (SchB) has many functions in cell protection as a natural medicine. In this study, we investigated the protective effects of SchB on the hypothermic preservation of hUCMSCs. METHODS: hUCMSCs were isolated from Wharton’s jelly. Subsequently, hUCMSCs were exposed to cold storage (4 °C) and 24-h re-warming. After that, cells viability, surface markers, immunomodulatory effects, reactive oxygen species (ROS), mitochondrial integrity, apoptosis-related and antioxidant proteins expression level were evaluated. RESULTS: SchB significantly alleviated the cells injury and maintained unique properties such as differentiation potential, level of surface markers and immunomodulatory effects of hUCMSCs. The protective effects of SchB on hUCMSCs after hypothermic storage seemed associated with its inhibition of apoptosis and the anti-oxidative stress effect mediated by nuclear factor erythroid 2–related factor 2 signaling. CONCLUSION These results demonstrate SchB could be used as an agent for hypothermic preservation of hUCMSCs.

Objectives: To investigated the safety and efficacy of treating patients with acute non-ST-segment elevation myocardial infarction (NSTEMI) and elevated levels of N-terminal pro-hormone B-type natriuretic peptide (NT-proBNP) with levosimendan within 24 hours of first medical contact (FMC). Methods: This multicenter, open-label, block-randomized controlled trial (NCT03189901) investigated the safety and efficacy of levosimendan as an early management strategy of acute heart failure (EMS-AHF) for patients with NSTEMI and high NT-proBNP levels. This study included 255 patients with NSTEMI and elevated NT-proBNP levels, including 142 males and 113 females with a median age of 65 (58-70) years, and were admitted in the emergency or outpatient departments at 14 medical centers in China between October 2017 and October 2021. The patients were randomly divided into a levosimendan group (n=129) and a control group (n=126). The primary outcome measure was NT-proBNP levels on day 3 of treatment and changes in the NT-proBNP levels from baseline on day 5 after randomization. The secondary outcome measures included the proportion of patients with more than 30% reduction in NT-proBNP levels from baseline, major adverse cardiovascular events (MACE) during hospitalization and at 6 months after hospitalization, safety during the treatment, and health economics indices. The measurement data parameters between groups were compared using the t-test or the non-parametric test. The count data parameters were compared between groups using the χ² test. Results: On day 3, the NT-proBNP levels in the levosimendan group were lower than the control group but were statistically insignificant [866 (455, 1 960) vs. 1 118 (459, 2 417) ng/L, Z=-1.25,P=0.21]. However, on day 5, changes in the NT-proBNP levels from baseline in the levosimendan group were significantly higher than the control group [67.6% (33.8%,82.5%)vs.54.8% (7.3%,77.9%), Z=-2.14, P=0.03]. There were no significant differences in the proportion of patients with more than 30% reduction in the NT-proBNP levels on day 5 between the levosimendan and the control groups [77.5% (100/129) vs. 69.0% (87/126), χ²=2.34, P=0.13]. Furthermore, incidences of MACE did not show any significant differences between the two groups during hospitalization [4.7% (6/129) vs. 7.1% (9/126), χ²=0.72, P=0.40] and at 6 months [14.7% (19/129) vs. 12.7% (16/126), χ²=0.22, P=0.64]. Four cardiac deaths were reported in the control group during hospitalization [0 (0/129) vs. 3.2% (4/126), P=0.06]. However, 6-month survival rates were comparable between the two groups (log-rank test, P=0.18). Moreover, adverse events or serious adverse events such as shock, ventricular fibrillation, and ventricular tachycardia were not reported in both the groups during levosimendan treatment (days 0-1). The total cost of hospitalization [34 591.00(15 527.46,59 324.80) vs. 37 144.65(16 066.90,63 919.00)yuan, Z=-0.26, P=0.80] and the total length of hospitalization [9 (8, 12) vs. 10 (7, 13) days, Z=0.72, P=0.72] were lower for patients in the levosimendan group compared to those in the control group, but did not show statistically significant differences. Conclusions: Early administration of levosimendan reduced NT-proBNP levels in NSTEMI patients with elevated NT-proBNP and did not increase the total cost and length of hospitalization, but did not significantly improve MACE during hospitalization or at 6 months.
Male ; Female ; Humans ; Aged ; Natriuretic Peptide, Brain ; Simendan/therapeutic use* ; Non-ST Elevated Myocardial Infarction ; Heart Failure/drug therapy* ; Peptide Fragments ; Arrhythmias, Cardiac ; Biomarkers ; Prognosis

Objective To study the optimal amount of chloropropane combined with low-dose bupivacaine during elective mixed hemorrhoidectomy and to observe the incidence of urinary retention under the combined anesthetic regimen.Methods Prospectively recruited patients with mixed hemorrhoids,L3-L5 subarachnoid nerve block anesthesia was used,the first patient was experimentally applied 3％chloropropane hydrochloride injection 3.0 mL slowly pushed in,after 5 min observation,3％chloropropane hydrochloride 6.0 mL was formally injected,when the visual analogue scale(VAS)was ≤2,the second patient had 1/6 probability of receiving a lower dose(1.0 mL decrease)or 5/6 probability of maintaining the current dose;when the VAS score was＞2,the second case had a 1/6 probability of receiving a higher dose(1.0 mL increase)or a 5/6 probability of maintaining the current dose.The 90％effective dose(ED90)value of chloropropane hydrochloride,the incidence of postoperative urinary retention,the saved dose of chloropropane hydrochloride,the VAS score of analgesic effect within 15 d after surgery,and the safety evaluation.Isotonic regression equation was used to calculate the ED90,95％confidence interval for chloroprocaine hydrochloride.Results The overall incidence of postoperative urinary retention was 19.18％(14 cases/73 cases),incidence of urinary retention between the initial dosage groups possessed statistical differences(P＜0.05).The incidence of urinary retention were 57.14％,0 and 42.86％in 8.0-13.0 mL,14.0-16.0 mL and 17.0-18.0 mL groups,respectively;compared with the population without urinary retention in the same dose group,the 14.0-16.0 mL and 17.0-18.0 mL had statistical difference(P＜0.05),8.0-13.0 mL group did not have statistical difference(P＞0.05).The mean salvage dose was(13.44±1.57)mL,and no significant linear trend was seen in the salvage dose of chloropropane hydrochloride with increasing initial dose(P＞0.05).The VAS scores at 0,4,12 and 24 h postoperatively were 1.55±0.90,6.55±0.44,2.95±0.93 and 1.78±0.69,respectively;a linear decreasing trend in VAS scores was observed in the 4-24 h postoperative period(P＞0.05).The overall incidence of adverse drug reactions was 16.44％(12 cases/73 cases).Conclusion ED90 of chloropropane hydrochloride combined with low-dose bupivacaine anesthesia in L3-L5 subarachnoid nerve block anesthesia for mixed hemorrhoids surgery was 11.76 mL.The combined anesthesia scheme can reduce the incidence of postoperative urinary retention and the total dose of anesthesia rescue.The incidence of adverse drug reactions is low and has certain clinical safety.