Rising frequency of ozone-favorable synoptic weather patterns contributes to 2015-2022 ozone increase in Guangzhou

Objective weather classification methods have been extensively applied to identify dominant ozone-favorable synoptic weather patterns (SWPs), however, the consistency of different classification methods is rarely examined. In this study, we apply two widely-used objective methods, the self-organizing map (SOM) and K-means clustering analysis, to derive ozone-favorable SWPs at four Chinese megacities in 2015-2022. We find that the two algorithms are largely consistent in recognizing dominant ozone-favorable SWPs for four Chinese megacities. In the case of classifying six SWPs, the derived circulation fields are highly similar with a spatial correlation of 0.99 between the two methods, and the difference in the mean frequency of each SWP is less than 7%. The six dominant ozone-favorable SWPs in Guangzhou are all characterized by anomaly higher radiation and temperature, lower cloud cover, relative humidity, and wind speed, and stronger subsidence compared to climatology mean. We find that during 2015-2022, the occurrence of ozone-favorable SWPs days increases significantly at a rate of 3.2 day/year, faster than the increases in the ozone exceedance days (3.0 day/year). The interannual variability between the occurrence of ozone-favorable SWPs and ozone exceedance days are generally consistent with a temporal correlation coefficient of 0.6. In particular, the significant increase in ozone-favorable SWPs in 2022, especially the Subtropical High type which typically occurs in September, is consistent with a long-lasting ozone pollution episode in Guangzhou during September 2022. Our results thus reveal that enhanced frequency of ozone-favorable SWPs plays an important role in the observed 2015-2022 ozone increase in Guangzhou.

A novel antimicrobial peptide WBp-1 from wheat bran: Purification, characterization and antibacterial potential against Listeria monocytogenes

This study introduces a novel antimicrobial peptide (AMP), WBp-1, isolated from wheat bran and purified via reversed-phase high-performance liquid chromatography. The amino acid sequence, determined as IITGASSGIGKAIAKHFI by LC-MS/MS, was composed predominantly of alkaline and hydrophobic residues. WBp-1 was predicted to be a stable, hydrophobic, cationic peptide with an α-helical structure. Moreover, it displayed significant antibacterial efficacy against Listeria monocytogenes, with a minimum inhibitory concentration of 150 μg/mL. Further mechanistic studies suggest that WBp-1 exerts its bactericidal activity by disrupting cell membrane integrity, impeding peptidoglycan synthesis by binding to penicillin-binding protein 4 via hydrogen bonding, increasing cell permeability, altering membrane potential and fluidity, and altering surface hydrophobicity. Interestingly, WBp-1 showed minimal hemolytic activity and cytotoxicity against LO2 cells, even at 16× MIC. These findings highlight the strong potential of WBp-1 as a novel antibacterial agent and food preservative against Listeria monocytogenes.

Development and validation of machine learning models for predicting cancer-related fatigue in lymphoma survivors

BACKGROUND

New cases of lymphoma are rising, and the symptom burden, like cancer-related fatigue (CRF), severely impacts the quality of life of lymphoma survivors. However, clinical diagnosis and treatment of CRF are inadequate and require enhancement.

OBJECTIVE

The main objective of this study is to construct machine learning-based CRF prediction models for lymphoma survivors to help healthcare professionals accurately identify the CRF population and better personalize treatment and care for patients.

METHODS

A cross-sectional study in China recruited lymphoma patients from June 2023 to March 2024, dividing them into two datasets for model construction and external validation. Six machine learning algorithms were used in this study: Logistic Regression (LR), Random Forest, Single Hidden Layer Neural Network, Support Vector Machine, eXtreme Gradient Boosting, and Light Gradient Boosting Machine (LightGBM). Performance metrics like the area under the receiver operating characteristic (AUROC) and calibration curves were compared. The clinical applicability was assessed by decision curve, and Shapley additive explanations was employed to explain variable significance.

RESULTS

CRF incidence was 40.7 % (dataset I) and 44.8 % (dataset II). LightGBM showed strong performance in training and internal validation. LR excelled in external validation with the highest AUROC and best calibration. Pain, total protein, physical function, and sleep disturbance were important predictors of CRF.

CONCLUSION

The study presents a machine learning-based CRF prediction model for lymphoma patients, offering dynamic, data-driven assessments that could enhance the development of automated CRF screening tools for personalized management in clinical practice.

Mesenchymal Stem Cells Engineered by Multicomponent Coassembled DNA Nanofibers for Enhanced Wound Healing

A major challenge for stem cell therapies, such as using mesenchymal stem cells to treat skin injuries, is the stable engraftment of exogenous cells and the maintenance of their regenerative capacities in the wound areas. DNA-based self-assembly strategies can be used for artificial and multifunctional cell surface engineering to stabilize and enhance their functions for therapeutic applications. Here, we developed DNA nanofiber-decorated stem cells, in which DNA-based, multivalent fiber-like structures were self-assembled in situ on the cell surfaces. These engineered stem cells have demonstrated robust reactive oxygen species (ROS) scavenging effects, specific adhesion to damaged vascular endothelial cells, and the ability to enhance angiogenesis, which were effective and safe for acute or chronic wound healing in a mouse model with excisional skin injury. This DNA nanostructure-engineered stem cell provides a novel therapeutic platform for the treatment of tissue damage.

Clinical manifestations and treatment of candidemia caused by different Candida species: a retrospective study

OBJECTIVE

Candidemia leads to higher mortality and longer hospital-stay. While the studies about the clinical manifestations of candidemia caused by different Candida species and the relationship between the antifungal drugs and prognosis were rarely performed.

METHODS

This retrospective study enrolled all 94 patients diagnosed as candidemia from January 2020 to July 2023 in BTCH. Demographic information, comorbidities, laboratory parameters, medications and prognosis were collected and analyzed.

RESULTS

C. albicans was the most common specie of candidemia. There was no significant difference in age, gender and hospital-mortality in different species groups. Higher-level and longer duration of broad-spectrum antibiotic use, lower BMI, hypoalbuminemia, longer duration of PN and history of G+ coccemia were conclusive about mortality. The C.tropicalis group had higher SCRE levels (F = 8.40, P = 0.03) and shorter TTP (F = 5.03, P < 0.01) than other species. No distinction was found in different antifungal drugs groups including triazoles and echinocandins after 7 days treatment (χ2 = 0.05, P = 0.81). The efficacy was no difference between triazoles and echinocandins in the different species groups. (χ12 = 1.20, P1 = 0.75; χ22 = 0.05, P2 = 0.81).

CONCLUSION

C. albicans accounts the most among candida induecd candidemia.The C.tropicalis group had higher SCRE levels and shorter TTP than other groups. Elder, hypoproteinemia, lower BMI, longer duration and higher-level of broad-spectrum antibiotic use, longer PN support and G+ coccemia increase risks for candidemia. The efficacy of triazoles and echinocandins are the same when blood culture turned negative in 7 days.

Integrative Proteomic and Phosphoproteomic Profiling Reveals the Salt-Responsive Mechanisms in Two Rice Varieties (Oryza Sativa subsp. Japonica and Indica)

Salinity stress induces ionic and osmotic imbalances in rice plants that in turn negatively affect the photosynthesis rate, resulting in growth retardation and yield penalty. Efforts have, therefore, been carried out to understand the mechanism of salt tolerance, however, the complexity of biological processes at proteome levels remains a major challenge. Here, we performed a comparative proteome and phosphoproteome profiling of microsome enriched fractions of salt-tolerant (cv. IR73; indica) and salt-susceptible (cv. Dongjin/DJ; japonica) rice varieties. This approach led to the identification of 5856 proteins, of which 473 and 484 proteins showed differential modulation between DJ and IR73 sample sets, respectively. The phosphoproteome analysis led to the identification of a total of 10,873 phosphopeptides of which 2929 and 3049 phosphopeptides showed significant differences in DJ and IR73 sample sets, respectively. The integration of proteome and phosphoproteome data showed activation of ABA and Ca2+ signaling components exclusively in the salt-tolerant variety IR73 in response to salinity stress. Taken together, our results highlight the changes at proteome and phosphoproteome levels and provide a mechanistic understanding of salinity stress tolerance in rice.

HYPOXIA induces lncRNA HOTAIR for recruiting RELA in papillary thyroid cancer cells to upregulate miR-181a and promote angiogenesis

BACKGROUND

Papillary thyroid carcinoma (PTC) is one of the most common subtypes of thyroid carcinoma. Exosomal miR-181a plays an important role in the development of PTC. This study examined the regulatory mechanism of miR-181a under conditions of hypoxia and its impact on angiogenesis.

METHODS

A ribonucleoprotein immunoprecipitation (RIP) experiment was conducted to verify the interaction between HOTAIR and RELA. The relationship between RELA and the miR-181a promoter was detected by ChIP-qPCR. Short hairpin (sh) RNA was designed to knock down HOTAIR in TPC cells. The underlying mechanism of miR-181a was verified by use of dual-luciferase assays and rescue experiments. The regulatory effect of GATA6 on angiogenesis was studied using CCK8, EdU, Transwell, and western blot assays.

RESULTS

A RIP assay showed that HOTAIR could bind to RELA under hypoxic conditions. ChIP-qPCR and dual luciferase assays showed RELA could interact with the miR181a promoter and upregulate miR-181a. Knockdown of HOTAIR downregulated miR-181a in TPC-1 cells, and the downregulation could be rescued by RELA overexpression. MiR-181a downregulated GATA6 in HUVEC cells. Overexpression of GATA6 inhibited HUVEC proliferation, migration, tube formation, and EGFR expression. Exosomal miR-181a promoted angiogenesis by downregulating GATA6 expression.

CONCLUSION

HOTAIR activated RELA to upregulate miR-181a during hypoxia. Exosomal miR-181a promotes tumor angiogenesis by downregulating GATA6.

Correlation of serum DKK1 level with skeletal phenotype in children with osteogenesis imperfecta

PURPOSE

We aim to detect serum DKK1 level of pediatric patients with OI and to analyze its relationship with the genotype and phenotype of OI patients.

METHODS

A cohort of pediatric OI patients and age-matched healthy children were enrolled. Serum levels of DKK1 and bone turnover biomarkers were measured by enzyme-linked immunosorbent assay. Bone mineral density (BMD) was measured by Dual-energy X-ray absorptiometry. Pathogenic mutations of OI were detected by next-generation sequencing and confirmed by Sanger sequencing.

RESULTS

A total of 62 OI children with mean age of 9.50 (4.86, 12.00) years and 29 healthy children were included in this study. The serum DKK1 concentration in OI children was significantly higher than that in healthy children [5.20 (4.54, 6.32) and 4.08 (3.59, 4.92) ng/mL, P < 0.001]. The serum DKK1 concentration in OI children was negatively correlated with height (r = - 0.282), height Z score (r = - 0.292), ALP concentration (r = - 0.304), lumbar BMD (r = - 0.276), BMD Z score of the lumbar spine and femoral neck (r = - 0.32; r = - 0.27) (all P < 0.05). No significant difference in serum DKK1 concentration was found between OI patients with and without vertebral compression fractures. In patients with spinal deformity (22/62), serum DKK1 concentration was positively correlated with SDI (r = 0.480, P < 0.05). No significant correlation was observed between serum DKK1 concentration and the annual incidence of peripheral fractures, genotype and types of collagen changes in OI children.

CONCLUSION

The serum DKK1 level was not only significantly elevated in OI children, but also closely correlated to their skeletal phenotype, suggesting that DKK1 may become a new biomarker and a potential therapeutic target of OI.

Extracorporeal photopheresis vs. systemic immunosuppression for immune-related adverse events: Interim analysis of a prospective two-arm study

BACKGROUND

Checkpoint inhibitor-induced steroid-refractory (sr) and steroid-dependent (sd) immune-related adverse events (irAE) account for about 11 % of irAE. Although these patients face worse outcomes due to irAE mortality and/or sustained immunosuppression, which impairs anti-tumor response, there is no established second-line treatment based on prospective trial data.

METHODS

This prospective comparative study investigates outcomes of extracorporeal photopheresis (ECP), an immunomodulating therapy, versus second-line immunosuppressants (SLI) in sr/sd-irAE. The primary endpoint was longitudinal change in immunophenotype; secondary endpoints were outcome of irAE and tumor response. Patient demographics, quality of life (EORTC QLQ-C30; global health status (GHS/QoL)) and longitudinal blood samples were analyzed at baseline; in weeks 1, 4, 8, and 12.

RESULTS

At interim analysis, 21 patients (11 ECP, 10 SLI) with 7 different sr/sd-irAE were included. Compared with the SLI group, the ECP group demonstrated a higher clinical response rate of irAE (93 % vs. 80 %; 95 % CI 0.83-1.92; P = 0.54) and a better GHS/QoL score throughout all follow-up visits. ECP patients showed a numerically higher overall survival (23 vs. 12 months; 95 % CI 0.02-3.02; P = 0.27) and lower cancer progression rates (33 % vs. 67 %; 95 % CI 0.09-1.60; P = 0.52). Immunophenotyping revealed changes in immune cell populations and the regulation of immune checkpoints. There were no significant safety issues in either treatment group.

CONCLUSION

This prospective comparative study supports the clinical efficacy of ECP in the treatment of sr/sd-irAE in comparison to the SLI cohort. Thus, ECP represents a potential treatment option for this indication, given its good safety profile while maintaining anti-tumor response.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05700565, https://classic.

CLINICALTRIALS

gov/ct2/show/NCT05700565.

Safety-critical event-triggered control of nonlinear systems with tunable input-to-state safe barrier functions

This paper investigates safety-critical event-triggered control (ETC) for nonlinear systems. It proposes a new ETC strategy that ensures event-triggered safety by using a tunable input-to-state safe barrier function. Then, a method is devised to effectively save communication resources and reduce computational load through the construction of a suitable dynamic event-triggered mechanism. Furthermore, the exclusion of Zeno behavior is guaranteed for the closed-loop system. Finally, this paper culminates by presenting two illustrative examples that showcase the effectiveness of proposed control strategies.

Alterations in the axon initial segment plasticity is involved in early pathogenesis in Alzheimer's disease

Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder, characterized by the early presence of amyloid-β (Aβ) and hyperphosphorylated tau. Identifying the neuropathological changes preceding cognitive decline is crucial for early intervention. Axon initial segment (AIS) maintains the orderly structure of the axon and is responsible for initiating action potentials (APs). To investigate the role of AIS in early stages of AD pathogenesis, we focused on alterations in the AIS of neurons from APP/PS1 mouse models harboring familial AD mutations. AIS length and electrophysiological properties were assessed in neurons using immunostaining and patch-clamp techniques. The expression and function of ankyrin G (AnkG) isoforms were evaluated by western blot and rescue experiments. We observed a significant shortening of AIS in APP/PS1 mice, which correlated with impaired action potential propagation. Furthermore, a decrease in the 480 kDa isoform of AnkG was observed. Rescue of this isoform restored AIS plasticity and improved long-term potentiation in APP/PS1 neurons. Our study implicates AIS plasticity alterations and AnkG dysregulation as early events in AD. The restoration of AIS integrity by the 480 kDa AnkG isoform presents a potential therapeutic strategy for AD, underscoring the importance of targeting AIS stability in neurodegenerative diseases.

[Severe cardiotoxic characteristics associated with allogeneic hematopoietic stem cell transplantation preconditioning in patients with aplastic anemia]

Objective: To delineate the clinical characteristics and outcomes associated with severe cardiac toxicity during the preconditioning phase of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with aplastic anemia (AA). Methods: This retrospective case series study included 31 patients with severe AA who underwent allo-HSCT and were diagnosed with severe cardiac toxicity at the Hematology Department of Peking University People's Hospital from August 2012 to June 2022. The clinical manifestations of severe cardiac toxicity observed during the preconditioning process were assessed. Patient survival was assessed using the Kaplan-Meier method. Results: In this cohort of 31 patients, the median follow-up period was 9 days (range: 4-365 days). Severe cardiac toxicity manifested within 6 days after the initial cyclophosphamide (Cy) administration. Twenty patients died within 30 days of initiating Cy preconditioning, of which 16 patients died due to severe cardiac toxicity within 25 days. Patients whose cardiac function improved within 30 days post-preconditioning showed a median survival duration of 222 days (n=11). Troponin I (TNI) levels in patients who died within 30 days of initiating Cy preconditioning began increasing on day 5 post-Cy, peaking sharply by day 9 after a notable rise on day 8. B-type natriuretic peptide (BNP) levels in patients who died within 30 days of initiating Cy preconditioning started to rise from day 1, stabilized between days 2 and 5, and then doubled daily from days 6 to 8, remaining elevated thereafter. Notably, the initial increases in BNP and TNI correlated with electrocardiogram (ECG) signs of low voltage and T-wave inversion in 83.87% of cases (n=26). Most patients (n=28, 90.32%) were administered corticosteroid therapy. In those with restored cardiac function, the ejection fraction returned to >50% within 30 days of initiating Cy preconditioning. Conclusions: Patients with severe cardiac toxicity during the preconditioning phase of allo-HSCT typically exhibit early, sustained, and marked elevations in myocardial damage markers, including BNP and TNI, accompanied by ECG abnormalities following Cy administration, with BNP often increasing first. These indicators are associated with rapid disease progression and high mortality. Prompt initiation of treatment upon clinical diagnosis is critical for improving survival outcomes.

Synergistic water quality and soil organic carbon sequestration benefits of winter cover crops

Winter cover crops (WCCs) are promising best management practices for reducing nitrogen and sediment pollution and increasing soil organic carbon (SOC) sequestration in agricultural fields. Although previous watershed studies assessed water quality benefits of growing WCCs in the Chesapeake Bay watershed, the SOC sequestration impacts remain largely unknown. Here, we designed six WCC scenarios in the Tuckahoe Watershed (TW) to understand potential synergies or tradeoffs between multiple impacts of WCCs. Besides corroborating the nitrate reduction benefits of WCCs that have been reported in previous studies, our results also demonstrated comparable reduction in sediment. We also found that the six WCC scenarios can sequester 0.45-0.92 MgC ha-1 yr-1, with early-planted WCCs having more than 70% SOC sequestration benefits compared with their late-planted counterparts. With a linear extrapolation to all the cropland in Maryland, WCCs hold potential to contribute 2.1-4.4% toward Maryland's 2030 Greenhouse Gases reduction goal. Additionally, we showed that WCCs can noticeably increase evapotranspiration and decrease water yield and streamflow, potentially impacting aquatic ecosystem health and water supply. Overall, this study highlights the synergistic water quality and SOC sequestration benefits of WCCs in the Chesapeake Bay watershed. Meanwhile, sustainable adoption of WCCs into existing crop rotations will also require careful assessment of their impact on water availability.

Enhanced UV Light Responsivity in <110>-Oriented 2D Perovskites Realized by Pressure-induced Ultrafast Exciton Transport

Two-dimensional (2D) <100>-oriented perovskites exhibit superior optoelectronic properties, offering significant potential in photovoltaic, light-emitting, and photodetection applications. Nevertheless, their enlarged interlayer spacing restricts longitudinal carrier transport, thereby limiting its potential applications. While <110>-oriented 2D perovskites provide a prospective solution with their compact interlayer spacing, their inherent structure, characterized by octahedra tilting, indirectly hinders carrier transport due to the generation of self-trapped excitons (STEs) caused by strong electron-phonon coupling. Here, we adeptly regulate the photoluminescence (PL) from STEs to free excitons (FEs) emission within the 2D <110>-oriented (API)PbBr4 single crystal through structure optimization under pressure treatment. Besides, we observed anisotropic FE transport with an anisotropy ratio of 4.97. The exciton mobility reaches a peak of 93.6 cm2 V-1s-1 at 2.7 GPa, a value comparable to those of their three-dimensional (3D) counterparts, which is attributed to a reduction in electron-phonon coupling and exciton reduced mass. Additionally, this ultrafast exciton transport significantly enhances UV light responsivity, exhibiting an increase of approximately 5000 times at 2.7 GPa in comparison to ambient conditions. These findings highlight the prospective application of 2D <110>-oriented perovskites in high-performance optoelectronic devices through intrinsic structural modulation.

An Organometallic Umpolung Approach for Iron-Mediated Propargylic C-H Etherification

The synthesis of propargyl ethers is an efficient way to access a variety of pharmaceuticals and natural products. However, direct etherification of simple alkynes via propargylic C-H activation remains largely underreported, while propargylic substitution of prefunctionalized alkyne starting materials remains the dominant method for the synthesis of propargyl ethers. Herein, we report an organometallic umpolung approach for iron-mediated C-H propargylic etherification. The stepwise iron-mediated C-H activation followed by mild oxidative functionalization enables the first use of unadorned alkynes to preferentially couple with alcohols for the efficient synthesis of synthetically important propargylic ethers with excellent functional group compatibility, chemoselectivity and regioselectivity.

Protective Effect of Protocatechuic Aldehyde on Cerebral Ischemia/Reperfusion Injury in Rats through Blood-Brain Barrier Protection

Cerebral ischemia can lead to destruction of the blood-brain barrier (BBB), the main cause of cerebral edema and cerebral infarction. BBB damage is also one of the key factors affecting the result of drug therapy. We studied the protective effect of 5-day pretreatment with protocatechuic aldehyde (PAL) at doses of 10 and 20 mg/kg on BBB function and structure after middle cerebral artery occlusion/reperfusion (MCAO/R) in rats. The infarct volume, behavioral neurological deficit score, and Evans blue content in the brain were estimated. We also evaluated the content of nitric oxide (NO) and activities of inducible and neuronal NO synthases. Expression of aquaporin-4 (AQP-4), occludin, claudin-5, and MMP-3 in the brain tissues was estimated by Western blotting. The BBB ultrastructure was analyzed under an electron microscope. We revealed that PAL at both used doses significantly reduced the neurological deficit score, brain infarct volume, and Evans blue extravasation. Electron microscopy showed that PAL significantly improved the ultrastructure of BBB and alleviated its injury. Pretreatment with PAL increased expression of occludin and claudin-5 and reduced expression of AQP-4 and MMP-3. At the same time, the release of NO and activities of NO synthases were notably inhibited. Our results suggest that PAL can be a promising compound to attenuate cerebral ischemia resulting from occlusion/reperfusion injury via BBB protection.

TREM2 signaling in Parkinson's disease: Regulation of microglial function and α-synuclein pathology

BACKGROUND

Parkinson's disease (PD) is characterized by the loss of dopaminergic neurons, abnormal accumulation of α-synuclein (α-syn), and microglial activation. Triggering receptor expressed on myeloid cells 2 (TREM2) regulates multiple functions of microglia in the brain, and several studies have shown that TREM2 variant R47H is a risk factor for PD. However, the regulation of microglia by TREM2 in PD remains poorly understood.

METHODS

We constructed PD cell and animal models using α-syn preformed fibrils. siRNA knockdown and lentiviral overexpression were used to perturb TREM2 levels in cells, and TREM2 knockout mice and lentiviral overexpression was used in animal models to investigate the effects of TREM2 on microglial function, α-syn-related pathology, and dopaminergic neuron degeneration.

RESULTS

Microglia phagocytosed α-syn preformed fibrils in a concentration- and time-dependent manner, with some capacity to degrade α-syn aggregates. TREM2 expression increased in PD. In the context of PD, TREM2 knockout mice exhibited worsened pathological α-syn spread, decreased microglial reactivity, and increased loss of TH-positive neurons in the substantia nigra compared to wild-type mice. TREM2 overexpression enhanced reactive microglial aggregation towards the pathological site. Cellular experiments revealed that reduced TREM2 impaired microglial phagocytosis and proliferation, but enhanced autophagy via the PI3K/AKT/mTOR pathway.

CONCLUSION

TREM2 signaling in PD maintains microglial phagocytosis, proliferation, and reactivity, stabilizing autophagy and proliferation via the PI3K/AKT/mTOR pathway. Regulating TREM2 levels may be beneficial in PD treatment.

[Treatment of chronic sinus tract leakage at rectal anastomosis with anal fistula endoscopy]

Objective: To introduce the method of using anal fistula endoscope to treat chronic sinus tract leakage at rectal anastomosis site. Methods: We used anal fistula endoscopy to treat a patient with chronic sinus tract leakage after radical resection of rectal cancer, mainly including the following 5 steps: (1) establishing a water injection circulation system through the anus; (2) scraping off purulent coating and mucosa on the surface of the sinus tract with the brush; (3) hemostasis and removal of necrotic tissue with electrocoagulation rods; (4) filling the sinus tract with bioprotein gel; (5) compressing the sinus tract with transanal drainage tube. Results: The patient is a 70 year old male with rectal cancer. After undergoing 3D laparoscopic assisted radical resection of rectal cancer via abdominal anterior resection (Dixon's procedure) and diverting ileostomy surgery for more than 3 months, leakage of the rectal anastomosis was found through colonoscopy and anal iodine water contrast imaging .The patient started eating and flowing juice 6 hours after surgery, got out of bed 24 hours after surgery, and was discharged 48 hours after the removal of the anal canal. Three months after surgery, colonoscopy and transanal iodine hydrography showed that the sinus repair was intact. The diverting ileostomy was reduced 4 months after surgery. Conclusion: Anal fistula endoscope is safe and feasible for the treatment of chronic sinus tract anastomotic leakage in selected patients.

[Analysis of perinatal outcomes in pregnant women with the resolution of placenta previa in the second trimester]

Objective: To investigate perinatal outcomes of pregnant women with the resolution of placenta previa in the second trimester. Methods: This study was a retrospective cohort study, which included singleton pregnant women who received prenatal care and delivered at Peking University Third Hospital from January 1st 2019 to December 31st 2020. A total of 403 pregnant women diagnosed with placenta previa by ultrasound at 20-24 weeks of gestation and the placental position returned to normal before delivery were included in the study group, and 403 pregnant women with normal placental position matched 1∶1 were the control group. The primary outcome was postpartum hemorrhage rate, and secondary outcomes included postpartum bleeding volume, severe hemorrhage complications, blood transfusion, drug application, the application of instrument or surgical hemostasis measures, gestational week of delivery, and neonatal outcomes. The perinatal outcomes were analyzed by univariate and multivariate logistic regression methods. Results: (1) Compared with the control group, the incidence of postpartum hemorrhage [10.4% (42/403) vs 17.6% (71/403)], postpartum hemorrhage volume (median: 375 vs 400 ml), the proportion of postpartum hemorrhage≥500 ml [18.6% (75/403) vs 30.5% (123/403)], and the proportion of application of instrument or surgical hemostasis measures [1.7% (7/403) vs 4.5% (18/403)] in the study group were increased, and the differences were statistically significant (all P<0.05). Neonatal outcomes, including birth weight, small for gestational age, hospitalization in neonatal intensive care unit and incidence of neonatal asphyxia, were compared between the two groups, and there were no statistically significant differences (all P>0.05). (2) In pregnant women with vaginal delivery, the postpartum hemorrhage rate [31.7% (66/208) vs 17.5% (39/223)], postpartum hemorrhage volume (median: 390 vs 380 ml), the proportion of instrument or surgical hemostasis measures [3.8% (8/208) vs 0.4% (1/223)] of the study group were higher than those of the control group, and the differences were statistically significant (all P<0.05). There was no significant difference in the rate of postpartum hemorrhage between the study group and the control group who gave birth by cesarean setion (P=0.545), but the proportion of postpartum hemorrhage≥500 ml in the study group and the control group were 29.2% (57/195) and 20.0% (36/180), and the difference was statistically significant (P=0.039). (3) The results of multivariate analysis showed that compared with the control group, the risk of postpartum hemorrhage (aOR=2.042, 95%CI: 1.313-3.175), the application of drugs (aOR=1.684, 95%CI: 1.142-2.484) and the application of instruments or surgical hemostasis measures (aOR=2.696, 95%CI: 1.089-6.675) were significantly increased in the study group (all P<0.05). Among women who delivered vaginally, the risk of postpartum hemorrhage in the study group was 2.021 times greater than that in the control group (95%CI: 1.269-3.220; P=0.003). Conclusion: In women with placental previa in the second trimester of pregnancy, even if the placental position returns to normal before delivery, it is still a high risk factor for postpartum hemorrhage, especially in vaginal delivery.