OBJECTIVE To investigate the stability of 5-fluorouracil （5-FU） in human blood and to establish a standardized clinical sampling and delivery procedure for therapeutic drug monitoring （TDM） of 5-FU. METHODS The EDTA-anticoagulated whole blood was used as the matrix to prepare stability assessment samples of 5-FU at both low （200 ng/mL） and high （5 000 ng/mL） concentrations （with groups without stabilizer and with 1% volume ratio of stabilizer）. The stability assessment samples were placed under room temperature （[ 25±2） ℃] and refrigerated （2-8 ℃） conditions， with sampling at 0， 0.5， 1， 2， 4， 7， and 24 h. After vortexing and centrifugation， the upper plasma layer was collected； proteins were precipitated using methanol， and the concentration of 5-FU in plasma was determined by liquid chromatography-tandem mass spectrometry. Based on the whole blood stability results， clinical sampling and delivery procedures were established. RESULTS The concentration of 5-FU in blank whole blood samples without stabilizers was significantly lower than that in samples with stabilizers （P＜0.05）. However， varying volumes （10， 25， 50 μL） of stabilizers had no significant effect on the measured concentrations of 5-FU in stability assessment samples with low and high concentrations （P＞0.05）. Without the addition of a stabilizer， low- and high-concentration 5-FU whole blood samples remained stable at room temperature for 0.5 h and 1 h， respectively， and under refrigeration for 2 h and 7 h， respectively. After the addition of a 1% stabilizer， the whole blood samples remained stable for up to 24 h under both room temperature and refrigerated conditions. Based on these findings， the following procedure was established： after collection， whole blood samples could be temporarily stored at room temperature （≤0.5 h） or at 4　℃ （≤2 h）， and transported at 2-8　℃. Upon delivery to the laboratory， a 1% volume ratio of stabilizer must be added immediately， followed by centrifugation within 24 h. The resulting plasma should be stored at －20 ℃ . CONCLUSIONS 5-FU in whole blood exhibits poor stability at room temperature. Refrigeration at 2-8　℃ slightly improves stability ， but degradation still occurs rapidly. Adding a stabilizer at a 1% volume ratio significantly prolongs the refrigerated storage time. The established sampling and transport procedure for 5-FU TDM innovatively introduces the stabilizer addition step at the laboratory sample reception stage （rather than immediately after blood draw）. This approach ensures analytical quality while offering greater adaptability to real-world clinical sampling conditions， significantly improving practical feasibility.

Severe open tibiofibular fractures account for approximately 28.1% of all open fractures. Among them, Gustilo-Anderson type IIIB/C fractures present significant clinical challenges due to associated bone and soft tissue defects, high infection rates, and risk of amputation. Inadequate preoperative assessment may lead to suboptimal emergency surgical planning or intraoperative complications. Historically, external fixation was often preferred, but this approach has been associated with limitations such as restricted joint mobility, delayed bone union, joint stiffness, and disuse osteoporosis, resulting in poor functional recovery. With advancements of debridement techniques, standardization of antibiotic use, and popularization of early soft tissue coverage, early internal fixation has gained broader acceptance. Nevertheless, controversies persist regarding the choice of fixation method, timing of definitive fixation, use of reamed versus unreamed intramedullary nailing, and necessity of fibular fixation. To standardize the diagnosis and early management of severe open tibiofibular fractures, reduce complication rates, and improve functional recovery, the Society of Microsurgery of the Chinese Medical Association organized a panel of domestic experts to develop the Evidence-based guideline for the diagnosis and early fixation of severe open tibiofibular fractures ( version 2025), using evidence-based methodology. The guidelines provided 12 recommendations covering diagnostic and early fixation strategies of severe open tibiofibular fractures, aiming to provide clinicians with scientifically grounded and standardized guidance.

Severe open tibiofibular fractures account for approximately 28.1% of all open fractures. Among them, Gustilo-Anderson type IIIB/C fractures present significant clinical challenges due to associated bone and soft tissue defects, high infection rates, and risk of amputation. Inadequate preoperative assessment may lead to suboptimal emergency surgical planning or intraoperative complications. Historically, external fixation was often preferred, but this approach has been associated with limitations such as restricted joint mobility, delayed bone union, joint stiffness, and disuse osteoporosis, resulting in poor functional recovery. With advancements of debridement techniques, standardization of antibiotic use, and popularization of early soft tissue coverage, early internal fixation has gained broader acceptance. Nevertheless, controversies persist regarding the choice of fixation method, timing of definitive fixation, use of reamed versus unreamed intramedullary nailing, and necessity of fibular fixation. To standardize the diagnosis and early management of severe open tibiofibular fractures, reduce complication rates, and improve functional recovery, the Society of Microsurgery of the Chinese Medical Association organized a panel of domestic experts to develop the Evidence-based guideline for the diagnosis and early fixation of severe open tibiofibular fractures ( version 2025), using evidence-based methodology. The guidelines provided 12 recommendations covering diagnostic and early fixation strategies of severe open tibiofibular fractures, aiming to provide clinicians with scientifically grounded and standardized guidance.

Objective:To analyze the clinical characteristics of patients with inflammatory bowel disea-ses(IBD)in pre-pregnancy,pregancy and loctation.Methods:The clinical data of pregnancy compli-cated with IBD in Department of Obstetrics and Gynecology of Peking University Third Hospital and deli-very from September 2011 to June 2022 were collected.The clinical characteristics of the patients were analyzed retrospectively.According to the state of diseases during pre-pregnancy,pregnancy and lactation,the patients were divided into active and remission group,and the two groups were compared interms of pre-pregnancy counseling,nutritional status,pregnancy and delivery complications,gestational week,mode of delivery,and neonatal outcome.Results:A total of 33 pregnant women with IBD were included in this study,of which 7 delivered a second child,for a total of 40 deliveries,with 36 natural pregnan-cies(90.0％)and 4 assisted reproductions(10.0％).Among the 40 cases,21 cases(52.5％)were sustained in remission in pre-pregnancy,pregnancy and lactation,and 19 cases(47.5％)in disease ac-tivity,of which 8 cases(42.1％)were due to self-withdrawal of drugs or failure to take medicine regu-larly.Compared with the activity group,the disease remission group had a higher rate of pre-pregnancy counseling(57.1％vs.15.8％,P=0.010),and higher levels of hemoglobin[(112.67±8.53)g/L vs.(102.84±5.23)g/L,P＜0.001],serum total protein[(66.58±6.34)g/L vs.(60.83±6.25)g/L,P=0.006],serum albumin[36.4(35.1,38.3)g/L vs.34.3(31.1,35.6)g/L,P=0.006],se-rum calcium[(2.25±0.10)μmol/L vs.(2.13±0.15)μmol/L,P=0.004],but a lower incidence of gestational hypertensive disorders(0 vs.31.6％,P=0.007).In 40 deliveries,there were 27 cases of vaginal delivery(67.5％),13 cases of cesarean section(32.5％).The analysis of neonatal outcomes showed 38 full-term deliveries and 2 preterm deliveries;1 case of macrosomia,1 case of small-for-gesta-tional-age,1 case of low birth weight and 3 cases of birth defects.There were 10 newborns admitted to neonatal intensive care unit,including 4 cases of neonatal infections and 2 cases of neonatal jaundice.Conclusion:Pre-pregnancy counseling and evaluation of IBD patients are very important,and good preg-nancy outcomes can be obtained through careful management during pregnancy in the most of the pa-tients.

Bone defects caused by different causes such as trauma, severe bone infection and other factors are common in clinic and difficult to treat. Usually, bone substitutes are required for repair. Current bone grafting materials used clinically include autologous bones, allogeneic bones, xenografts, and synthetic materials, etc. Other than autologous bones, the major hurdles of rest bone grafts have various degrees of poor biological activity and lack of active ingredients to provide osteogenic impetus. Bone marrow contains various components such as stem cells and bioactive factors, which are contributive to osteogenesis. In response, the technique of bone marrow enrichment, based on the efficient utilization of components within bone marrow, has been risen, aiming to extract osteogenic cells and factors from bone marrow of patients and incorporate them into 3D scaffolds for fabricating bone grafts with high osteoinductivity. However, the scientific guidance and application specification are lacked with regard to the clinical scope, approach, safety and effectiveness. In this context, under the organization of Chinese Orthopedic Association, the Expert consensus for the clinical application of autologous bone marrow enrichment technique for bone repair ( version 2023) is formulated based on the evidence-based medicine. The consensus covers the topics of the characteristics, range of application, safety and application notes of the technique of autologous bone marrow enrichment and proposes corresponding recommendations, hoping to provide better guidance for clinical practice of the technique.

Infectious bone defect is bone defect with infection or as a result of treatment of bone infection. It requires surgical intervention, and the treatment processes are complex and long, which include bone infection control,bone defect repair and even complex soft tissue reconstructions in some cases. Failure to achieve the goals in any step may lead to the failure of the overall treatment. Therefore, infectious bone defect has been a worldwide challenge in the field of orthopedics. Conventionally, sequestrectomy, bone grafting, bone transport, and systemic/local antibiotic treatment are standard therapies. Radical debridement remains one of the cornerstones for the management of bone infection. However, the scale of debridement and the timing and method of bone defect reconstruction remain controversial. With the clinical application of induced membrane technique, effective infection control and rapid bone reconstruction have been achieved in the management of infectious bone defect. The induced membrane technique has attracted more interests and attention, but the lack of understanding the basic principles of infection control and technical details may hamper the clinical outcomes of induced membrane technique and complications can possibly occur. Therefore, the Chinese Orthopedic Association organized domestic orthopedic experts to formulate An evidence-based clinical guideline for the treatment of infectious bone defect with induced membrane technique ( version 2023) according to the evidence-based method and put forward recommendations on infectious bone defect from the aspects of precise diagnosis, preoperative evaluation, operation procedure, postoperative management and rehabilitation, so as to provide useful references for the treatment of infectious bone defect with induced membrane technique.

Objective: To investigate the effects of lactoprotein iron chelates on rats with iron deficiency anaemia (IDA), so as to provide insights into developing and utilizing novel iron supplements. Methods: Seventy weaning female SPF-graded rats of the SD strain were randomly divided into the control group (A), model group (B), ferrous sulfate group (C), lactoferrin group (D), lactoferrin iron chelate group (E), Casein oligopeptide iron chelate group (F) and whey protein oligopeptide iron chelate group (G), with 10 rats in each group. The rats in group A were fed with normal diet, and the others were fed with poor iron diet for IDA modeling. The corresponding interventions were given by intragastric administration once a day. The iron ion concentrations of group C, E, F and G were 2.0 mg/kg, and the protein and oligopeptide concentrations of group D, E, F and G were 2 000 mg/kg. Body weight and hemoglobin of rats were measured weekly during 21-day intervention. At the end, peripheral blood samples were collected, and blood routine, iron metabolism and liver function indicators were determined. Results: After the intervention, among blood routine indicators, the rats in group C, E, F and G showed elevated hemoglobin, red blood cell, mean corpuscular volume and hematocrit, and decreased free protoporphyrin and mean corpuscular hemoglobin concentration when compared with the rats in group B (all P<0.05); among iron metabolism indicators, the rats in group C, E and G showed elevated serum ferritin, the rats in group C, E, F and G showed elevated serum iron, the rats in group C, D, E, F and G showed decreased unsaturated iron binding capacity and total iron binding capacity when compared with the rats in group B (all P<0.05); among liver function indicators, the rats in group E and G showed decreased alanine transaminase when compared with the rats in group B (both P<0.05). Conclusions Lactoprotein alone could not completely improve IDA in rats compared with traditional iron supplement (ferrous sulfate). Lactoprotein iron chelate, especially whey protein oligopeptide iron chelate, could significantly improve IDA, iron reserve and liver function damage in rats.

Background: Domestic yaks are the most important livestock species on the Qinghai-Tibetan Plateau. Adult female yaks normally breed in the warm season (July to September) and enter anestrous in the cold season (November to April). Nevertheless, it is unclear how ovarian activity is regulated at the molecular level. Objectives: The peculiarities of yak reproduction were assessed to explore the molecular mechanism of postpartum anestrus ovaries in yaks after pregnancy and parturition. Methods: Sixty female yaks with calves were observed under natural grazing in Haiyan County, Qinghai Province. Three yak ovaries in pregnancy and postpartum anestrus were collected. RNA sequencing and quantitative proteomics were employed to analyze the pregnancy and postpartum ovaries after hypothermia to identify the genes and proteins related to the postpartum ovarian cycle. Results: The results revealed 841 differentially expressed genes during the postpartum hypoestrus cycle; 347 were up-regulated and 494 genes were down-regulated. Fifty-seven differential proteins were screened: 38 were up-regulated and 19 were down-regulated. The differential genes and proteins were related to the yak reproduction process, rhythm process, progesterone-mediated oocyte maturation, PI3K/AKT signaling pathway, and MAPK signaling pathway categories. Conclusions Transcriptome and proteomic sequencing approaches were used to investigate postpartum anestrus and pregnancy ovaries in yaks. The results confirmed that BHLHE40, SF1IX1, FBPX1, HSPCA, LHCGR, BMP15, and ET-1R could affect postpartum hypoestrus and control the state of estrus.

Background: Interferon lambda receptor 1 (IFNLR1) is a type II cytokine receptor that clings to interleukins IL-28A, IL29B, and IL-29 referred to as type III IFNs (IFN-λs). IFN-λs act through the JAK-STAT signaling pathway to exert antiviral effects related to preventing and curing an infection. Although the immune function of IFN-λs in virus invasion has been described, the molecular mechanism of IFNLR1 in that process is unclear. Objectives: The purpose of this study was to elucidate the role of IFNLR1 in the pathogenesis and treatment of porcine reproductive and respiratory syndrome virus (PRRSV). Methods: The effects of IFNLR1 on the proliferation of porcine alveolar macrophages (PAMs) during PRRSV infection were investigated using interference and overexpression methods. Results: In this study, the expressions of the IFNLR1 gene in the liver, large intestine, small intestine, kidney, and lung tissues of Dapulian pigs were significantly higher than those in Landrace pigs. It was determined that porcine IFNLR1 overexpression suppresses PRRSV replication. The qRT-PCR results revealed that overexpression of IFNLR1 upregulated antiviral and IFN-stimulated genes. IFNLR1 overexpression inhibits the proliferation of PAMs and upregulation of p-STAT1. By contrast, knockdown of IFNLR1 expression promotes PAMs proliferation. The G0/G1 phase proportion in IFNLR1-overexpressing cells increased, and the opposite change was observed in IFNLR1-underexpressing cells. After inhibition of the JAK/STAT signaling pathway, the G2/M phase proportion in the IFNLR1-overexpressing cells showed a significant increasing trend. In conclusion, overexpression of IFNLR1 induces activation of the JAK/STAT pathway, thereby inhibiting the proliferation of PAMs infected with PRRSV. Conclusion Expression of the IFNLR1 gene has an important regulatory role in PRRSVinfected PAMs, indicating it has potential as a molecular target in developing a new strategy for the treatment of PRRSV.

Background: Interferon lambda receptor 1 (IFNLR1) is a type II cytokine receptor that clings to interleukins IL-28A, IL29B, and IL-29 referred to as type III IFNs (IFN-λs). IFN-λs act through the JAK-STAT signaling pathway to exert antiviral effects related to preventing and curing an infection. Although the immune function of IFN-λs in virus invasion has been described, the molecular mechanism of IFNLR1 in that process is unclear. Objectives: The purpose of this study was to elucidate the role of IFNLR1 in the pathogenesis and treatment of porcine reproductive and respiratory syndrome virus (PRRSV). Methods: The effects of IFNLR1 on the proliferation of porcine alveolar macrophages (PAMs) during PRRSV infection were investigated using interference and overexpression methods. Results: In this study, the expressions of the IFNLR1 gene in the liver, large intestine, small intestine, kidney, and lung tissues of Dapulian pigs were significantly higher than those in Landrace pigs. It was determined that porcine IFNLR1 overexpression suppresses PRRSV replication. The qRT-PCR results revealed that overexpression of IFNLR1 upregulated antiviral and IFN-stimulated genes. IFNLR1 overexpression inhibits the proliferation of PAMs and upregulation of p-STAT1. By contrast, knockdown of IFNLR1 expression promotes PAMs proliferation. The G0/G1 phase proportion in IFNLR1-overexpressing cells increased, and the opposite change was observed in IFNLR1-underexpressing cells. After inhibition of the JAK/STAT signaling pathway, the G2/M phase proportion in the IFNLR1-overexpressing cells showed a significant increasing trend. In conclusion, overexpression of IFNLR1 induces activation of the JAK/STAT pathway, thereby inhibiting the proliferation of PAMs infected with PRRSV. Conclusion Expression of the IFNLR1 gene has an important regulatory role in PRRSVinfected PAMs, indicating it has potential as a molecular target in developing a new strategy for the treatment of PRRSV.