Background: Cytomegalovirus (CMV) infection remains a major cause of morbidity, mortality, and increased healthcare burden in recipients of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Its clinical manifestations range from asymptomatic CMV replication to end-organ diseases such as pneumonia, gastroenteritis, and retinitis, all of which are associated with a higher rate of nonrelapse mortality. Methods: We reviewed case records of children who underwent allo-HSCT at our center between April 2013 and October 2024. CMV monitoring was performed weekly until at least day +100 post-HSCT using a quantitative polymerase chain reaction assay. All patients received acyclovir prophylaxis. Pre-emptive intravenous ganciclovir therapy was initiated when CMV-DNA levels exceeded 500 IU/mL Results: A total of 150 consecutive patients (58% male) were included. The median age at HSCT was 6.3 years (interquartile range [IQR], 3.4–11.3 years). Indications for HSCT were hematologic malignancy (n=81, 54.0%), inborn errors of immunity and bone marrow failure (n=46, 30.7%), and hemoglobinopathy (n=23, 15.3%). Donor and recipient CMV seropositivity rates were 86.7% and 94.0%, respectively. CMV infection occurred in 43.4% of patients, with a median onset of 30 days post-HSCT (IQR, 21–47 days). There were five (3.3%) cases of CMV disease, resulting in one (0.7%) CMV-related death. Human leukocyte antigen (HLA)-haploidentical donor status (odds ratio [OR], 5.00; 95% confidence interval [CI], 2.43–10.29; P<0.001) and the use of serotherapy in the conditioning regimen (OR, 2.87; 95% CI, 1.47–5.60; P=0.002) were significantly associated with an increased risk of CMV infection. Conclusions CMV infection was a common occurrence, particularly among patients with HLA-haploidentical donors. Preventive strategies such as weekly surveillance and pre-emptive ganciclovir therapy proved effective in preventing overt CMV disease.

Inteins are unique protein insertion sequences capable of self-excision, enabling the covalent ligation of flanking extein peptides via amide bond formation. This process proceeds spontaneously without requiring external enzymes, cofactors, or chemical reagents, granting inteins exceptional biocompatibility and traceless performance in protein engineering applications. Split inteins represent a specialized and versatile subclass whose splicing domains are encoded by two separate gene fragments rather than a single continuous open reading frame. These fragments, known as the N-terminal (IntN) and C-terminal (IntC) split inteins, associate through non-covalent interactions including hydrophobic forces, hydrogen bonds, and van der Waals forces to assemble into an active three-dimensional structure, which then drives efficient extein ligation and enables protein trans-splicing. Protein trans-splicing mediated by split inteins has become a cornerstone for traceless protein ligation owing to its high specificity and irreversibility, fundamentally reshaping strategies for protein modification, assembly, and functional regulation. Compared with traditional chemical ligation methods, split intein systems require no complex chemical derivatization of peptide fragments and can operate efficiently at micromolar concentrations under physiological conditions, thus avoiding structural and functional damage caused by organic reagents. In contrast to enzymatic ligation tools such as sortase, split inteins eliminate the need for additional enzymes or cofactors, simplifying reaction systems, reducing costs, and minimizing non-specific side products. These distinctive advantages render split inteins highly promising for applications in chemical biology, synthetic biology, and biopharmaceutical development. In recent years, deepened mechanistic understanding has established structure-guided rational design as the primary approach to overcoming key limitations of split inteins, including intrinsic aggregation propensity, strict extein sequence dependence, and limited splicing efficiency. Bioinformatic tools have been used to identify aggregation-prone regions in the IntN fragment, and site-directed mutagenesis of hydrophobic residues, relocation of split sites, or removal of misfolding-prone sequences has substantially reduced in vitro aggregation and improved soluble expression and assembly activity. Rational engineering of catalytic residues and adjacent flexible loops has relaxed strict amino acid preferences at extein junctions, enhancing sequence tolerance and reducing the risk of functional impairment in target proteins. Consensus design based on multiple sequence alignments has yielded ultra-fast splicing variants such as Cfa DnaE and Cat-TerL, which exhibit significantly accelerated kinetics and improved tolerance to denaturing conditions. Meanwhile, advances in structural biology have further clarified the conformational dynamics and catalytic mechanisms of splicing, supporting the precise design of high-performance intein modules. On this basis, electrostatic interaction tuning and metagenomic screening have yielded multiple mutually orthogonal split intein pairs, enabling selective multi-fragment protein ligation and providing new routes for the efficient synthesis of large multi-domain functional proteins. With these engineered split inteins offering continuously improved performance and expanded applicability, protein trans-splicing has been widely applied in numerous cutting-edge areas of protein research and biomedicine. In gene delivery, split intein-based systems overcome the packaging limit of adeno-associated viral vectors, enabling the accurate reconstitution of large therapeutic proteins and base editors in target cells, thereby enhancing the efficacy and scope of gene therapy for genetic diseases. In internal protein sequence editing, split inteins mediate precise sequence replacement and modification in flexible regions or loops of target proteins, without the need for complex multi-step ligation and protein refolding involved in traditional protein semisynthesis. In protein-protein interaction studies, intein-mediated splicing covalently captures transient and weak intracellular complexes, enabling sensitive, high-throughput interaction detection and drug screening. In synthetic biology, conditionally controllable splicing systems support the construction of diverse intracellular and cell-surface biological logic gates for the precise regulation of cellular behavior. In mechanistic biochemical research, split inteins enable photocatalytic proximity labeling and site-specific tagging, allowing the preparation of homogeneous protein samples carrying precise post-translational modifications such as ubiquitination and polyglutamylation for chromatin interactome analysis and epigenetic studies. Moreover, covalent trapping strategies using split inteins stabilize transient enzymatic intermediates, providing unprecedented insights into molecular mechanisms such as nucleosome ubiquitination that are difficult to elucidate using conventional methods. This review systematically summarizes key technological advances in split inteins over the past decade, highlighting engineering strategies, mechanistic insights, and the development of orthogonal components. It comprehensively surveys emerging applications at the frontiers of protein research, analyzes current core challenges, and proposes future directions, particularly emphasizing artificial intelligence-driven de novo design and novel splicing pathways to break existing technical bottlenecks. By enabling traceless, efficient, and versatile protein manipulation, split inteins continue to serve as indispensable tools that drive innovation in protein engineering and fundamental life science research.

Objective To evaluate the effectiveness of preoperative immunosuppressive therapy combined with surgical intervention for Behçet's disease. Methods A retrospective study was conducted on Behçet's disease patients who underwent cardiovascular surgery at Guangdong Provincial People's Hospital from 2012 to 2021. Patients were divided into an immunosuppressive group and a non-immunosuppressive group based on whether they received immunosuppressive therapy before surgery. The complications and long-term survival rates of the two groups were analyzed. Results A total of 28 patients were included, among which 2 patients underwent reoperation, a total of 30 surgeries were performed, including 16 males (53.3%), and the age at diagnosis was 37 (31, 45) years. There were 15 surgeries in the immunosuppressive group and 15 surgeries in the non-immunosuppressive group. Compared with the non-immunosuppressive group, the incidence of complications during hospitalization in the immunosuppressive group was lower (13.3% vs. 53.3%, P=0.008). One patient died in hospital, and the rest were discharged and followed up, with a median follow-up time of 38.7 (15.1, 57.3) months, and there was no statistically significant difference in long-term survival rate between the two groups (73.3% vs. 93.3%, P=0.158). There was no statistical difference in the cumulative incidence of complications one month (20% vs. 53%, P=0.058) and one year (27% vs. 60%, P=0.065) after surgery between the immunosuppressive group and the non-immunosuppressive group, but there was a statistical difference in the cumulative incidence of complications three years after surgery (47% vs. 92%, P=0.002). Conclusion Surgical treatment can save lives in Behçet's disease patients with cardiovascular diseases, but the incidence of postoperative complications is high. Timely use of immunosuppressants before cardiovascular surgery can reduce the incidence of postoperative complications.

ObjectiveTo investigate the protective effect and mechanism of action of flavonoid combination of Alpiniae Officinarum Rhizoma （A. officinarum） against Helicobacter pylori （H. pylori） gastritis in mice. MethodsAfter acclimatization for one week， 56 SPF-grade healthy C57BL/6J mice were gavaged with mixed antibiotics for three consecutive days. They were randomly divided into a normal group， model group， positive drug group （triple therapy group）， and low- and high-dose groups （100， 200 mg·kg^-1） of flavonoid combination of A. officinarum. The H. pylori gastritis mice model was established by gavage with H. pylori bacterial suspension in each group except for the normal group. After successful modeling， mice were administrated with corresponding drugs once a day for two weeks. Hematoxylin-eosin （HE） staining was used to observe the pathological changes in gastric tissue. Rapid urease test paper was used to detect the positive rate of H. pylori. Silver staining was used to observe the H. pylori adherence on the surface of gastric tissue. Immunohistochemistry was used to detect the protein expression of interleukin-8 （IL）-8 and myeloid differentiation factor （MyD88） in gastric tissue. The serum levels of IL-6， tumor necrosis factor-α （TNF-α）， IL-8， and IL-1β were detected by enzyme-linked immunosorbent assay （ELISA）. The expressions of phosphatidylinositol 3-kinase/protein kinase B （PI3K/Akt） protein were detected by Western blot. ResultsCompared with those in the normal group， mice in the model group had lower gastric weight coefficients， higher pH of gastric juice， 100% H. pylori infection rate， and significantly changed gastric histopathology. The expressions of IL-8 and MyD88 proteins in the gastric tissue of mice in the model group were significantly elevated， and the serum levels of inflammatory factors IL-6， TNF-α， IL-8， and IL-1β were significantly up-regulated in mice. Compared with that in the model group， the gastric weight coefficient of mice in each treatment group of the flavonoid combinations of A. officinarum was elevated （P<0.01）， and the pH of gastric juice was reduced （P<0.01）. The infection rate of H. pylori was reduced. The expressions of IL-8 and MyD88 proteins in the gastric tissue of mice in the treatment groups were significantly reduced （P<0.01）， and the serum levels of inflammatory factors IL-6， TNF-α， IL-8， and IL-1β were significantly reduced in a dose-dependent manner （P<0.01）. The flavonoid combinations of A. officinarum down-regulated the expression of PI3K and Akt proteins in H. pylori gastritis-infected cells （P<0.01）. ConclusionThe protective effect of flavonoid combinations of A. officinarum against H. pylori gastritis is associated with the inhibition of H. pylori infection rate and regulation of PI3K/Akt signaling pathway， resulting in inhibiting the release of inflammatory factors.

[Objective] To establish a cryopreservation protocol for small-volume (≤1 mL) red blood cells (RBCs) and to evaluate the reactivity and stability of blood group antigens after cryopreservation, so as to explore its potential application in immunohematology reference laboratories. [Methods] Small-volume RBCs were cryopreserved for 120 days, followed by thawing and deglycerolization to restore the RBC components. The quality of the RBCs was assessed. Serum antibodies were serially diluted and reacted with RBCs before and after cryopreservation, and agglutination scores were recorded to quantitatively evaluate the reactivity and stability of blood group antigens such as Rh, Duffy, Lewis, Kidd, M, and H. Flow cytometry was used to analyze the percentage and mean fluorescence intensity of ABO antigen expression on RBCs before and after cryopreservation to assess the usability of cryopreserved RBCs in flow immunophenotyping and blood group subtype studies. [Results] The hemolysis rate of thawed and deglycerolized RBCs was (0.27±0.10)%, with a supernatant free hemoglobin level of (0.52±0.14) g/L, and the RBC recovery rate was (69.12±7.91)%. The direct antiglobulin test (DAT) was negative for all thawed RBCs. There was no difference in the reactivity of blood group antigens before and after cryopreservation, and no difference in the percentage and mean fluorescence intensity of A and B antigen expression on RBCs before and after cryopreservation. [Conclusion] The small-volume RBC cryopreservation protocol can be applied to immunohematology analysis in reference laboratories and is expected to be widely used in blood group identification, antibody screening, identification, and blood group-related research.

ObjectiveTo investigate the processing technology of calcined Haematitum based on the concept of quality by design（QbD） and to assess its health risk. MethodsTaking whole iron content， Fe²⁺ dissolution content and looseness as critical quality attributes（CQAs）， and calcination temperature， calcination time， spreading thickness and particle size as critical process parameters（CPPs） determined by the failure mode and effect analysis（FMEA）， the processing technology of calcined Haematitum was optimized by orthogonal test combined with analytic hierarchy process-criteria importance through intercriteria correlation（AHP-CRITIC） hybrid weighting method. The contents of heavy metals and harmful elements were determined by inductively coupled plasma mass spectrometry， and the health risk assessment was carried out by daily exposure（EXP）， target hazard quotient（THQ） and lifetime cancer risk（LCR）， and the theoretical value of the maximum limit was deduced. ResultsThe optimal processing technology for calcined Haematitum was calcination at 650 ℃， calcination time of 1 h， particle size of 0.2-0.5 cm， spreading thickness of 1 cm， and vinegar quenching for 1 time［Haematitum-vinegar（10：3）］. The contents of 5 heavy metals and harmful elements in 13 batches of calcined Haematitum were all decreased with reductions of up to 5-fold. The cumulative THQ of 2 batches of samples was>1， while the cumulative THQ of all batches of Haematitum was>1. The LCR of As in 1 batches of Haematitum was 1×10^-6-1×10^-4， and the LCR of the rest was<1×10^-6， and the LCRs of calcined Haematitum were all<1×10^-6， indicating that the carcinogenic risk of calcined Haematitum was low， but special attention should still be paid to Haematitum medicinal materials. Preliminary theoretical values of the maximum limits of Cu， As， Cd， Pb and Hg were formulated as 1 014， 25， 17， 27， 7 mg·kg^-1. ConclusionThe optimized processing technology of calcined Haematitum is stable and feasible， and the contents of heavy metals and harmful elements are reduced after processing. Preliminary theoretical values of the maximum limits of Cu， As， Cd， Pb and Hg are formulated to provide a scientific basis for the formulation of standards for the limits of harmful elements in Haematitum.

ObjectiveTo investigate the processing technology of calcined Haematitum based on the concept of quality by design（QbD） and to assess its health risk. MethodsTaking whole iron content， Fe²⁺ dissolution content and looseness as critical quality attributes（CQAs）， and calcination temperature， calcination time， spreading thickness and particle size as critical process parameters（CPPs） determined by the failure mode and effect analysis（FMEA）， the processing technology of calcined Haematitum was optimized by orthogonal test combined with analytic hierarchy process-criteria importance through intercriteria correlation（AHP-CRITIC） hybrid weighting method. The contents of heavy metals and harmful elements were determined by inductively coupled plasma mass spectrometry， and the health risk assessment was carried out by daily exposure（EXP）， target hazard quotient（THQ） and lifetime cancer risk（LCR）， and the theoretical value of the maximum limit was deduced. ResultsThe optimal processing technology for calcined Haematitum was calcination at 650 ℃， calcination time of 1 h， particle size of 0.2-0.5 cm， spreading thickness of 1 cm， and vinegar quenching for 1 time［Haematitum-vinegar（10：3）］. The contents of 5 heavy metals and harmful elements in 13 batches of calcined Haematitum were all decreased with reductions of up to 5-fold. The cumulative THQ of 2 batches of samples was>1， while the cumulative THQ of all batches of Haematitum was>1. The LCR of As in 1 batches of Haematitum was 1×10^-6-1×10^-4， and the LCR of the rest was<1×10^-6， and the LCRs of calcined Haematitum were all<1×10^-6， indicating that the carcinogenic risk of calcined Haematitum was low， but special attention should still be paid to Haematitum medicinal materials. Preliminary theoretical values of the maximum limits of Cu， As， Cd， Pb and Hg were formulated as 1 014， 25， 17， 27， 7 mg·kg^-1. ConclusionThe optimized processing technology of calcined Haematitum is stable and feasible， and the contents of heavy metals and harmful elements are reduced after processing. Preliminary theoretical values of the maximum limits of Cu， As， Cd， Pb and Hg are formulated to provide a scientific basis for the formulation of standards for the limits of harmful elements in Haematitum.

Objective: For patients with elevated hematocrit (Hct), platelet-rich plasma (PRP) apheresis is prone to red blood cell contamination—commonly referred to as “flushing” or erythrocyte carryover—which compromises product quality and therapeutic efficacy. This study reports two clinicaly derived measures to mitigate this issue. Methods: For 21 patients with Hct ≥53%, intravenous 0.9% sodium chloride infusion before apheresis process (replacement method, n=13) or 0.9% sodium chloride fluids hemodilution within the centrifuge bowl during PRP apheresis process (dilution method, n=8) were given, respectively. The collection time, adverse reactions, and the celluar composition of PRP—including white blood cells, red blood cells, and platelet counts—were recorded and compared. Results: Neither method resulted in visible RBC contamination (“flushing”). The red blood cell counts [(0.021±0.014)×10 /L vs (0.019±0.011)×10 /L, P>0.05], white blood cell counts [(2.258±3.288) ×10 /L vs (0.557 5±1.203) ×10 /L, P>0.05], and platelet counts [(1 140±308.2)×10 /L vs (1 105±309.9)×10 /L, P>0.05] in the PRP products obtained by two methods all met the control standards of PRP. There was no significant difference [(2.268±0.927) vs (2.438±0.762) mL/min, P=0.669 2] between the two methods in terms of the speed of PRP collection. One case of adverse reaction occurred with the fluid replacement method, while no adverse reaction occurred with the dilution method. Conclusion: For patients with elevated Hct, both fluid replacement and dilution methods can effectively prevent RBC contamination during PRP collection, yielding products that meet clinical quality standards.

Receptor-interacting protein kinase 1 (RIPK1) plays an essential role in regulating the necroptosis and apoptosis in cerebral ischemia-reperfusion (I/R) injury. However, the regulation of RIPK1 kinase activity after cerebral I/R injury remains largely unknown. In this study, we found the downregulation of protein arginine methyltransferase 1 (PRMT1) was induced by cerebral I/R injury, which negatively correlated with the activation of RIPK1. Mechanistically, we proved that PRMT1 directly interacted with RIPK1 and catalyzed its asymmetric dimethylarginine, which then blocked RIPK1 homodimerization and suppressed its kinase activity. Moreover, pharmacological inhibition or genetic ablation of PRMT1 aggravated I/R injury by promoting RIPK1-mediated necroptosis and apoptosis, while PRMT1 overexpression protected against I/R injury by suppressing RIPK1 activation. Our findings revealed the molecular regulation of RIPK1 activation and demonstrated PRMT1 would be a potential therapeutic target for the treatment of ischemic stroke.

Two novel diketopiperazines (1 and 5), along with ten known compounds (2-4, 6-12) demonstrating significant skin inflammation inhibition, were isolated from a marine-derived fungus identified as Aspergillus sp. FAZW0001. The structural elucidation and configurational reassessments of compounds 1-5 were established through comprehensive spectral analyses, with their absolute configurations determined via single crystal X-ray diffraction using Cu Kα radiation, Marfey's method, and comparison between experimental and calculated electronic circular dichroism (ECD) spectra. Compounds 1, 2, and 8 exhibited significant anti-inflammatory activities in Propionibacterium acnes (P. acnes)-induced human monocyte cell lines. Compound 8 demonstrated the ability to down-regulate interleukin-1β (IL-1β) expression by inhibiting Toll-like receptor 2 (TLR2) expression and modulating the activation of myeloid differentiation factor 88 (MyD88), mitogen-activated protein kinase (MAPK), and nuclear factor κB (NF-κB) signaling pathways, thus reducing the cellular inflammatory response induced by P. acnes. Additionally, compound 8 showed the capacity to suppress mitochondrial reactive oxygen species (ROS) production and nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome activation, thereby reducing IL-1β maturation and secretion. A three-dimensional quantitative structure-activity relationships (3D-QSAR) model was applied to compounds 5-12 to analyze their anti-inflammatory structure-activity relationships.
Humans ; Aspergillus/chemistry* ; Diketopiperazines/isolation & purification* ; Anti-Inflammatory Agents/isolation & purification* ; Interleukin-1beta/genetics* ; Toll-Like Receptor 2/immunology* ; Propionibacterium acnes/drug effects* ; NF-kappa B/genetics* ; Molecular Structure ; Myeloid Differentiation Factor 88/immunology* ; Monocytes/immunology* ; NLR Family, Pyrin Domain-Containing 3 Protein/genetics* ; Cell Line