Preliminary exploration of animal models of congenital choledochal cysts.

BACKGROUND: Various animal models have been used to explore the pathogenesis of choledochal cysts (CCs), but with little convincing results. Current surgical techniques can achieve satisfactory outcomes for treatment of CCs. Consequently, recent studies have focused more on clinical issues rather than basic research. Therefore, we need appropriate animal models to further basic research. AIM: To establish an appropriate animal model that may contribute to the investigation of the pathogenesis of CCs. METHODS: Eighty-four specific pathogen-free female Sprague-Dawley rats were randomly allocated to a surgical group, sham surgical group, or control group. A rat model of CC was established by partial ligation of the bile duct. The reliability of the model was confirmed by measurements of serum biochemical indices, morphology of common bile ducts of the rats as well as molecular biology experiments in rat and human tissues. RESULTS: Dilation classified as mild (diameter, ≥ 1 mm to < 3 mm), moderate (≥ 3 mm to < 10 mm), and severe (≥ 10 mm) was observed in 17, 17, and 2 rats in the surgical group, respectively, while no dilation was observed in the control and sham surgical groups. Serum levels of alanine aminotransferase, aspartate aminotransferase, total bilirubin, direct bilirubin, and total bile acids were significantly elevated in the surgical group as compared to the control group 7 d after surgery, while direct bilirubin, total bilirubin, and gamma-glutamyltransferase were further increased 14 d after surgery. Most of the biochemical indices gradually decreased to normal ranges 28 d after surgery. The protein expression trend of signal transducer and activator of transcription 3 in rat model was consistent with the human CC tissues. CONCLUSION: The model of partial ligation of the bile duct of juvenile rats could morphologically simulate the cystic or fusiform CC, which may contribute to investigating the pathogenesis of CC.

Clinical characteristics of choledochal cysts with intrahepatic bile duct dilatations: an observational study.

Purpose: Whether a dilated intrahepatic bile duct (IHBD) has any effect on the prognosis of choledochal cyst (CC) remains controversial. We aimed to summarize the clinical characteristics and prognosis of CC with IHBD dilatation. Methods: One hundred ninety-two children diagnosed with CC were identified, including 127 without IHBD dilatation (group A) and 65 with IHBD dilatation (group B). A retrospective analysis was performed to explore the clinical characteristics and prognosis of CC with IHBD dilatation based on clinical indices, symptoms, and complications. Results: Compared with group A, incidences of jaundice and fever were higher in group B (P = 0.010 and P = 0.033). Preoperative total bilirubin, direct bilirubin, and indirect bilirubin were increased in group B compared to group A (P = 0.005, P < 0.001, and P = 0.014), as were preoperative ALT, AST, γ-GT, and total bile acid (P = 0.006, P = 0.025, P < 0.001, and P = 0.024). The risk of liver fibrosis or cirrhosis was significantly increased for group B compared with group A (P = 0.012) and also occurred earlier in group B (P = 0.006). In the dilated IHBDs, 95.4% (62 of 65) recovered to normal, and more than half of dilated IHBDs (37 of 65) recovered to normal in 1 week. Conclusion: Most IHBDs can recover to normal postoperatively in a short time, and proactive treatment is recommended for CC patients with IHBD dilatation for significant abnormal liver functions.

Sugarcane breeding: a fantastic past and promising future driven by technology and methods.

Sugarcane is the most important sugar and energy crop in the world. During sugarcane breeding, technology is the requirement and methods are the means. As we know, seed is the cornerstone of the development of the sugarcane industry. Over the past century, with the advancement of technology and the expansion of methods, sugarcane breeding has continued to improve, and sugarcane production has realized a leaping growth, providing a large amount of essential sugar and clean energy for the long-term mankind development, especially in the face of the future threats of world population explosion, reduction of available arable land, and various biotic and abiotic stresses. Moreover, due to narrow genetic foundation, serious varietal degradation, lack of breakthrough varieties, as well as long breeding cycle and low probability of gene polymerization, it is particularly important to realize the leapfrog development of sugarcane breeding by seizing the opportunity for the emerging Breeding 4.0, and making full use of modern biotechnology including but not limited to whole genome selection, transgene, gene editing, and synthetic biology, combined with information technology such as remote sensing and deep learning. In view of this, we focus on sugarcane breeding from the perspective of technology and methods, reviewing the main history, pointing out the current status and challenges, and providing a reasonable outlook on the prospects of smart breeding.

Enzymatic Degradation of Deoxynivalenol with the Engineered Detoxification Enzyme Fhb7.

In the era of global climate change, the increasingly severe Fusarium head blight (FHB) and deoxynivalenol (DON) contamination have caused economic losses and brought food and feed safety concerns. Recently, an FHB resistance gene Fhb7 coding a glutathione-S transferase (GST) to degrade DON by opening the critical toxic epoxide moiety was identified and opened a new window for wheat breeding and DON detoxification. However, the poor stability of Fhb7 and the elusiveness of the catalytic mechanism hinder its practical application. Herein, we report the first structure of Fhb7 at 2.41 Å and reveal a unique catalytic mechanism of epoxide opening transformation in GST family proteins. Furthermore, variants V29P and M10 showed that 5.5-fold and 266.7-fold longer half-life time than wild-type, respectively, were identified. These variants offer broad substrate scope, and the engineered biosafe Bacillus subtilis overexpressing the variants shows excellent DON degradation performance, exhibiting potential at bacterium engineering to achieve DON detoxification in the feed and biomedicine industry. This work provides a profound mechanistic insight into the enzymatic activities of Fhb7 and paves the way for further utilizing Fhb7-related enzymes in crop breeding and DON detoxification by synthetic biology.

Robotic-Assisted and Laparoscopic Splenectomy in Children: A Single Center Comparative Study.

Background: To explore the safety, efficacy, advantages, and disadvantages of robotic-assisted splenectomy (RS) in children by analyzing and comparing the clinical data of RS and laparoscopic splenectomy (LS). Methods: The clinical data of 35 children who underwent laparoscopic or RS or partial splenectomy from February 2010 to October 2022 were included. A retrospective analysis based on general information, clinical data, and prognosis were performed. Results: Among 35 cases, 14 cases, and 21 cases underwent RS and LS, respectively. The average operation time was 167 (120-224) minutes in the RS group and 176 (166-188) minutes in the LS group. The intraoperative blood loss was significantly larger in LS group than RS group (P = .0009). The length of hospital stay was significantly longer in LS group than RS group (P = .0015), and the hospitalization cost was significantly higher in RS group than LS group (P < .0001). There were no cases of conversion to laparotomy in the RS group, but two cases in the LS group. In terms of postoperative complications, there were one and three cases in the RS and LS groups, respectively. Conclusion: The Robotic Surgical System was safe and feasible in pediatric splenectomy or partial splenectomy which was an alternative to laparoscopic surgery.

Genome-wide DNase I-hypersensitive site assay reveals distinct genomic distributions and functional features of open chromatin in autopolyploid sugarcane.

The characterization of cis-regulatory DNA elements (CREs) is essential for deciphering the regulation of gene expression in eukaryotes. Although there have been endeavors to identify CREs in plants, the properties of CREs in polyploid genomes are still largely unknown. Here, we conducted the genome-wide identification of DNase I-hypersensitive sites (DHSs) in leaf and stem tissues of the auto-octoploid species Saccharum officinarum. We revealed that DHSs showed highly similar distributions in the genomes of these two S. officinarum tissues. Notably, we observed that approximately 74% of DHSs were located in distal intergenic regions, suggesting considerable differences in the abundance of distal CREs between S. officinarum and other plants. Leaf- and stem-dependent transcriptional regulatory networks were also developed by mining the binding motifs of transcription factors (TFs) from tissue-specific DHSs. Four TEOSINTE BRANCHED 1, CYCLOIDEA, and PCF1 (TCP) TFs (TCP2, TCP4, TCP7, and TCP14) and two ethylene-responsive factors (ERFs) (ERF109 and ERF03) showed strong causal connections with short binding distances from each other, pointing to their possible roles in the regulatory networks of leaf and stem development. Through functional validation in transiently transgenic protoplasts, we isolate a set of tissue-specific promoters. Overall, the DHS maps presented here offer a global view of the potential transcriptional regulatory elements in polyploid sugarcane and can be expected to serve as a valuable resource for both transcriptional network elucidation and genome editing in sugarcane breeding.

Robot-assisted abdominal surgery in children less than 5 months of age: retrospective cohort study.

BACKGROUND: Robot-assisted surgery is increasingly used in children. While robot-assisted surgery in children has been proved to be safe and feasible, use in infants is controversial. The purpose of this study was to present a study of robot-assisted abdominal surgery in children less than5 months of age. MATERIALS AND METHODS: A retrospective analysis of 111 patients less than 5 months of age who underwent abdominal surgery from April 2020 to December 2022 in our hospital. The data included clinical information, operative details, and postoperative outcomes. RESULTS: Among these 111 patients, 67 underwent robot-assisted surgery and 44 underwent laparoscopic-assisted surgery, the robot-assisted group includes 40 patients with Hirschsprung disease, 20 patients with choledochal cysts, and 7 patients with intestinal duplication, the laparoscopic-assisted group includes 26 patients with Hirschsprung disease, 9 patients with choledochal cysts, and 9 patients with intestinal duplication. For Hirschsprung disease, the operation time was significantly longer ( P =0.013) and the intraoperative bleeding was significantly less ( P =0.000) in the robot-assisted group than the laparoscopic assisted group. For choledochal cysts, the median operation time of 180 mins for the robot-assisted group was not significantly longer than the laparoscopic assisted surgery group at 160 mins ( P =0.153). For intestinal duplication, the operation time was significantly longer ( P =0.002) in the robot-assisted group than the laparoscopic assisted group. For these three diseases, the hospitalization expense was significantly higher ( P <0.05) in the robot-assisted group than the laparoscopic assisted group, there were no significant differences in complications, and postoperative fasting time between two groups ( P >0.05). CONCLUSION: Robot-assisted abdominal surgery in children less than 5 months of age is safe and feasible. This study showed that the surgical indications for the Da Vinci robot system in children can be extended to infants.

Robot-assisted resection of benign splenic tumors in children.

PURPOSE: Robotic surgery is becoming increasingly widely used in the field of pediatric surgery. The present study aimed to evaluate the safety and feasibility of robot-assisted resection of benign pediatric splenic tumors and to discuss the technical points. METHODS: A total of 32 patients who were diagnosed with benign splenic tumors and underwent minimally invasive surgery from January 2017 to September 2023 were included in the study. The clinical data including demographic criteria, operative details, and postoperative outcomes were analyzed retrospectively. RESULTS: Thirteen patients underwent robot-assisted surgery, and 19 patients underwent laparoscopic surgery. The median operation time was 150 min, with an interquartile range (IQR) of 120 to 200 min for the robot-assisted group and 140 min with an IQR of 105 to 180 min in the laparoscopic group (P = 0.318). Despite four cases in the laparoscopic group (21%) being converted to laparotomy because of intraoperative bleeding, compared with none in the robot-assisted group, there was no significant difference between two groups (P = 0.128). The intraoperative volume of blood loss was significantly less (P = 0.041), and the hospitalization expense was significantly higher (P = 0.000) in the robot-assisted group than for the laparoscopic group. There was no significant difference in patients' age, tumor size, postoperative feeding time, and the postoperative hospitalization time between two groups (P > 0.05). CONCLUSION: Robot-assisted benign splenic tumor resection was safe and feasible, and it reduced surgical trauma for the pediatric patient.

Molecular basis for the catalytic mechanism of human neutral sphingomyelinases 1 (hSMPD2).

Enzymatic breakdown of sphingomyelin by sphingomyelinase (SMase) is the main source of the membrane lipids, ceramides, which are involved in many cellular physiological processes. However, the full-length structure of human neutral SMase has not been resolved; therefore, its catalytic mechanism remains unknown. Here, we resolve the structure of human full-length neutral SMase, sphingomyelinase 1 (SMPD2), which reveals that C-terminal transmembrane helices contribute to dimeric architecture of hSMPD2 and that D111 - K116 loop domain is essential for substrate hydrolysis. Coupled with molecular docking, we clarify the binding pose of sphingomyelin, and site-directed mutagenesis further confirms key residues responsible for sphingomyelin binding. Hybrid quantum mechanics/molecular mechanics (QM/MM) molecular dynamic (MD) simulations are utilized to elaborate the catalysis of hSMPD2 with the reported in vitro substrates, sphingomyelin and lyso-platelet activating fator (lyso-PAF). Our study provides mechanistic details that enhance our knowledge of lipid metabolism and may lead to an improved understanding of ceramide in disease and in cancer treatment.

Comparation of robotic-assisted surgery and laparoscopic­assisted surgery in children with Hirschsprung's disease: a single-centered retrospective study.

BACKGROUND: There are few studies comparing robotic-assisted surgery (RAS) and laparoscopic-assisted surgery (LAS) in Hirschsprung's disease (HSCR). This study aimed to compare intraoperative and postoperative outcomes between RAS and LAS performed during the same period. METHODS: All consecutive 75 patients with pathologically diagnosed as HSCR who underwent Swenson pull-through surgery from April 2020 to Nov 2022, were included. Patients were divided into RAS group and LAS group and a retrospective analysis was performed based on clinical indexes and prognosis. RESULTS: A total of 75 patients were included, among which, 31 patients received RAS and 44 received LAS. The RAS and LAS groups had similar ages, sex, weight, postoperative hospital stays, and fasting times. Compared with LAS, blood loss (p = 0.002) and the incidence of Hirschsprung-associated enterocolitis (p = 0.046) were significantly lower in the RAS group. The first onset of Hirschsprung-associated enterocolitis in patients younger than 3 months occurred significantly earlier (p = 0.043). Two patients experienced anastomotic leakage in the LAS group and one patient experienced incisional hernia in the RAS group. The cost of RAS was significantly higher than that of LAS (p < 0.0001). CONCLUSIONS: RAS is a safe and effective alternative for HSCR children, and a delaying primary surgery until later in infancy (> 3 months) may improve outcomes.

Structural insights into the oligomeric effects on catalytic activity of a decameric feruloyl esterase and its application in ferulic acid production.

Oligomeric feruloyl esterase (FAE) has great application prospect in industry due to its potentially high stability and fine-tuned activity. However, the relationship between catalytic capability and oligomeric structure remains undetermined. Here we identified and characterized a novel, cold-adapted FAE (BtFae) derived from Bacteroides thetaiotaomicron. Structural studies unraveled that BtFae adopts a barrel-like decameric architecture unique in esterase families. By disrupting the interface, the monomeric variant exhibited significantly reduced catalytic activity and stability toward methyl ferulate, potentially due to its impact on the flexibility of the catalytic triad. Additionally, our results also showed that the monomerization of BtFae severely decreased the ferulic acid release from de-starched wheat bran and insoluble wheat arabinoxylan by 75 % and 80 %, respectively. Collectively, this study revealed novel connections between oligomerization and FAE catalytic function, which will benefit for further protein engineering of FAEs at the quaternary structure level for improved industrial applications.

Robot-assisted resection of choledochal cyst in children.

Background: The emergence of the robotic surgery system has assisted the further development of minimally invasive surgery by facilitating more delicate and precise complex procedures. The purpose of this study was to present a study of robot-assisted resection of the choledochal cyst and to discuss the technical points. Methods: In total, 133 patients who were diagnosed with a choledochal cyst and underwent surgery from April 2020 to February 2022 in the Children's Hospital, Zhejiang University School of Medicine, were retrospectively analyzed. The data were collected including the clinical information of the patients, operative details, and postoperative outcomes. Results: Among these 133 patients, 99 underwent robot-assisted surgery and 34 underwent laparoscopic assisted surgery. The median operation time was 180 min, with an interquartile range (IQR) of 170-210 min for the robot-assisted group and 180 min with an IQR of 157.5-220 min in the laparoscopic assisted group (P = 0.290). The detection rate of 82.5% for the distal opening of the cystic type of choledochal cyst was higher in the robot-assisted group than that in the laparoscopic assisted group at 34.8% (P = 0.000). The postoperative hospital stay was shorter (P = 0.009) and the hospitalization expense was higher (P = 0.000) in the robot-assisted group than that of the laparoscopic assisted group. There was no significant difference between the two groups in terms of complications, postoperative indwelling days of the abdominal drainage tube, intraoperative blood loss, and postoperative fasting time (P > 0.05). Conclusions: Robot-assisted resection of choledochal cyst is safe and feasible, it is ideal for the patient requiring a meticulous operation, and its postoperative recovery was shorter than for traditional laparoscopy.

Climate Variations in the Low-Latitude Plateau Contribute to Different Sugarcane (Saccharum spp.) Yields and Sugar Contents in China.

In China, the main sugarcane (Saccharum spp.) planting areas can be found in the low-latitude plateau (21° N-25° N, 97° E-106° E), which has most of the natural ecological types. However, there is limited information on the climate conditions of this region and their influence on sugarcane yield and sucrose content. Monthly variations in the main climate factors, namely, average air temperature (AAT), average relative humidity (ARH), average rainfall amount (ARA), and average sunshine duration (ASD), from 2000 to 2019 and sugarcane yield and sucrose content of 26 major sugarcane-producing areas from 2001/2002 to 2018/2019 were collected from the low-latitude plateau in Yunnan for studying the impact of climate variations on sugarcane yield and sucrose content. The results showed that AAT in the mid-growth season had a significant positive correlation with sucrose content (p < 0.05), and AAT in the late-growth season had a very significant positive correlation with sucrose content (p < 0.01). ARH in the mid-growth season had a significant positive correlation with sugarcane yield (p < 0.05). ARA in the early-growth season showed a significant positive correlation with sugarcane yield (p < 0.05). ASD in the late-growth season had a significant positive correlation with sugarcane yield (p < 0.05) and sucrose content (p < 0.01). The rainy and humid sugarcane areas were characterized by high ARA and ARH during the entire growth period, low AAT and ASD in the mid-growth season, and low AAT in the late-growth season, contributing to a high sugarcane yield, but not a high sucrose content. The low temperature and sunshine semi-humid sugarcane areas were characterized by the lowest AAT in the early and middle stages of sugarcane growth, less ASD in the early and middle stages, and less ARA in the early and late stages, which are unfavorable for sugarcane yield and sucrose content. The high temperature and humidity sugarcane areas were characterized by higher AAT and ARA, and moderate ASD during the entire growth period, resulting in good sugarcane growth potential and contributing to the sugarcane yield and sucrose content. The semi-humid and multi-sunshine sugarcane areas were characterized by the lowest ARH in the entire growth period, the lowest ARA in the middle and late seasons, and the longest ASD, contributing to an increase in sucrose content. The humid and sunny areas were characterized by the longest ASD and high ARH in the early and late seasons of sugarcane growth and moderate AAT and ARA during the entire growth season, which are beneficial for high sugarcane yield and sucrose content. Overall, these findings suggest that the sugarcane variety layout should be based on the climate type (of which there are five in the plateau), and corresponding cultivation practices should be used to compensate for the climatic conditions in various growth stages.

Acetylation coordinates the crosstalk between carbon metabolism and ammonium assimilation in Salmonella enterica.

Enteric bacteria use up to 15% of their cellular energy for ammonium assimilation via glutamine synthetase (GS)/glutamate synthase (GOGAT) and glutamate dehydrogenase (GDH) in response to varying ammonium availability. However, the sensory mechanisms for effective and appropriate coordination between carbon metabolism and ammonium assimilation have not been fully elucidated. Here, we report that in Salmonella enterica, carbon metabolism coordinates the activities of GS/GDH via functionally reversible protein lysine acetylation. Glucose promotes Pat acetyltransferase-mediated acetylation and activation of adenylylated GS. Simultaneously, glucose induces GDH acetylation to inactivate the enzyme by impeding its catalytic centre, which is reversed upon GDH deacetylation by deacetylase CobB. Molecular dynamics (MD) simulations indicate that adenylylation is required for acetylation-dependent activation of GS. We show that acetylation and deacetylation occur within minutes of "glucose shock" to promptly adapt to ammonium/carbon variation and finely balance glutamine/glutamate synthesis. Finally, in a mouse infection model, reduced S. enterica growth caused by the expression of adenylylation-mimetic GS is rescued by acetylation-mimicking mutations. Thus, glucose-driven acetylation integrates signals from ammonium assimilation and carbon metabolism to fine-tune bacterial growth control.

Cryo-EM structure of the cytosolic AhR complex.

Aryl hydrocarbon receptor (AhR) is an important ligand-activated transcription factor involved in the regulation of various important physiological functions. Here, we report the cryo-EM structures of the Hsp90-AhR-p23 complex with or without bound XAP2, where the structure of the mouse AhR PAS-B domain is resolved. A highly conserved bridge motif of AhR is responsible for the interaction with the Hsp90 dimeric lumen. The ligand-free AhR PAS-B domain is attached to the Hsp90 dimer and is stabilized in the complex with bound XAP2. In addition, the DE-loop and a group of conserved pocket inner residues in the AhR PAS-B domain are found to be important for ligand binding. These results reveal the structural basis of the biological functions of AhR. Moreover, the protein purification method presented here allows the isolation of stable mouse AhR protein, which could be used to develop high-sensitivity biosensors for environmental pollutant detection.

Developing new sugarcane varieties suitable for mechanized production in China: principles, strategies and prospects.

The sugar industry, which relates to people's livelihood, is strategic and fundamental in the development of agricultural economy. In China, sugar derived from sugarcane accounts for approximately 85% of total sugar production. Mechanization is the "flower" of sugarcane industry. As the saying goes "when there are blooming flowers, there will be sweet honey." However, due to limitations in land resources, technology, equipment, organization, and management, mechanization throughout the sugarcane production process has not yet brought about the economic benefits that a mechanized system should provide and has not reached an ideal yield through the integration of agricultural machinery and agronomic practice. This paper briefly describes how to initiate the mechanization of Chinese sugarcane production to promote the sound, healthy, and rapid development of the sugarcane industry, and how to ultimately achieve the transformation of sugarcane breeding in China and the modernization of the sugarcane industry from three perspectives, namely, requirements of mechanized production for sugarcane varieties, breeding strategies for selecting new sugarcane varieties suitable for mechanized production, and screening for sugarcane varieties that are suitable for mechanization and diversification in variety distribution or arrangement in China. We also highlight the current challenges surrounding this topic and look forward to its bright prospects.

Laparoscopic management of benign splenic tumors in children.

Background: The splenic tumor is relatively rare in children. However, diagnosing and managing this disease remain controversial. This study aimed to evaluate the clinical characteristics and pathological features of benign splenic tumors and to explore the feasibility and safety of laparoscopic splenectomy in children. Methods: The clinical data of all patients who were diagnosed with benign splenic tumors and admitted to our center between January 2014 and December 2020 were analyzed retrospectively. Factors that were documented included demographic criteria, clinical manifestations, preoperative examinations, surgical methods, histopathological characteristics, postoperative complications and outcomes. Results: Totally, 24 consecutive patients with a mean age of 10.21±2.59 years were operated laparoscopically. Nine patients presented with recurrent abdominal pain, vomiting or backache. The remaining 15 cases were asymptomatic and were identified incidentally. Laparoscopic total splenectomy (LTS) was performed in 12 cases, laparoscopic partial splenectomy (LPS) in 9 cases and deroofing of splenic cyst in 3 cases. No significant differences were observed in operation time, intraoperative bleeding and postoperative abdominal drainage between the LTS and LPS groups. Histopathology examination reported 12 cases of splenic epithelial cyst, 5 cases of splenic lymphangioma or lymphatic malformation, 3 cases of splenic hamartoma, 3 cases of splenic littoral cell angioma and 1 case of splenic hemangioma. No postoperative complications and tumor recurrence were observed. Conclusions: It is still difficult to precisely diagnose the splenic tumor preoperatively. Laparoscopic splenectomy is safe and feasible in treating the benign splenic tumors, and partial splenectomy is of great significance in preserving the immune function in children.

The rational design of iron-sulfur cluster binding site for prolonged stability in magnetoreceptor MagR.

Iron-sulfur proteins play essential roles in a wide variety of cellular processes such as respiration, photosynthesis, nitrogen fixation and magnetoreception. The stability of iron-sulfur clusters varies significantly between anaerobic and aerobic conditions due to their intrinsic sensitivity to oxygen. Iron-sulfur proteins are well suited to various practical applications as molecular redox sensors or molecular "wires" for electron transfer. Various technologies have been developed recently using one particular iron-sulfur protein, MagR, as a magnetic tag. However, the limited protein stability and low magnetic sensitivity of MagR hindered its wide application. Here in this study, the iron-sulfur binding site of pigeon clMagR was rationally re-designed. One such mutation, T57C in pigeon MagR, showed improved iron-sulfur binding efficiency and higher iron content, as well as prolonged thermostability. Thus, clMagRT57C can serve as a prototype for further design of more stable and sensitive magnetic toolbox for magnetogenetics in the future.