Retinal microcirculatory disorder is a key factor in the occurrence and development of diabetic retinopathy （DR）， and also an important link in the prevention and treatment of DR. The theory of "Gaozhuo" holds that the microcirculatory disorder in DR is based on the deficiency of spleen Qi and is characterized by the obstruction caused by "Gaozhuo" and blood stasis. The deficiency of spleen Qi is an essential precondition for the endogenous formation and accumulation of Gaozhuo， while Gaozhuo invasion is the direct cause of microcirculatory disorders in DR. The deficiency of spleen Qi and the endogenous formation of Gaozhuo mean the process in which glucose metabolism dysfunction induces an excessive production of inflammatory factors and lipid metabolites. The obstruction caused by "Gaozhuo" and blood stasis is the direct pathogenesis of microcirculatory disorders in DR， encompassing two stages： Gaozhuo obstruction and turbidity and stasis stagnation. Gaozhuo obstruction and turbidity and stasis stagnation represent the process in which inflammatory factors and lipid metabolites damage the retinal microcirculation and induce thrombosis， thus mediating microcirculatory disorders. Turbidity and stasis stagnation and blood extravasation outside the vessels reveal the progression to microvascular rupture and hemorrhage resulting from the microcirculatory disorders. According to the pathogenesis evolution of the theory of "Gaozhuo"， microcirculatory disorders in DR can be divided into deficiency of spleen Qi with Gaozhuo obstruction， deficiency of spleen Qi with turbidity and stasis stagnation， and turbidity and stasis stagnation with blood extravasation outside the vessels. Clinically， treatment principles should focus on strengthening the spleen and benefiting Qi， resolving turbidity， and dispersing stasis. Different syndrome patterns should be addressed with tailored therapies， such as enhancing the spleen and benefiting Qi while regulating Qi and reducing turbidity， strengthening the spleen and benefiting Qi while resolving turbidity and dispelling stasis， and strengthening the spleen and resolving turbidity while removing stasis and stopping bleeding. Representative prescriptions include modified Wendantang， modified Buyang Huanwutang， modified Danggui Buxuetang， Zhuixue Mingmu decoction， Tangmuqing， Shengqing Jiangzhuo Tongluo Mingmu prescription， Danhong Huayu decoction， and Yiqi Yangyin Huoxue Lishui formula.

ObjectiveTo investigate the therapeutic effects of the Anemarrhenae Rhizoma water extract （AR） on Alzheimer's disease （AD） model rats and to explore its potential underlying mechanisms. MethodsMale rats were intraperitoneally injected with D-galactose （100 mg·kg^-1） for 42 days， and on day 14， 1 μL of β-amyloid （Aβ_25-35， 2 g·L^-1） solution was injected into the hippocampus. Rats were randomly divided into a model group， low-dose AR （0.6 g·kg^-1）， medium-dose AR （1.2 g·kg^-1）， high-dose AR （2.4 g·kg^-1）， and a positive control group （donepezil， 5 mg·kg^-1）. Healthy rats receiving only a hippocampal injection of 1 μL of sterile saline served as the sham-operated group. From day 21， rats in the treatment groups were administered the corresponding drugs by gavage once daily for 21 consecutive days， while the blank control and model groups received an equal volume of saline. Learning and memory abilities were assessed using the Morris water maze. Brain tissue damage was observed by hematoxylin and eosin （HE） staining， and neuronal apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick-end labeling （TUNEL） staining. Levels of interleukin-1β （IL-1β）， tumor necrosis factor-α （TNF-α）， and interleukin-10 （IL-10） in brain tissues were measured by enzyme-linked immunosorbent assay （ELISA）. BV2 microglial cells were co-cultured with Aβ_25-35 （40 μmol·L^-1） for 2 h， and cell viability was determined by the CCK-8 assay to screen the optimal concentration of AR-containing serum （S-AR）. Cells were divided into blank control， Aβ_25-35， S-AR， EX527 ［silent information regulator 1 （SIRT1） inhibitor］， and S-AR+EX527 groups. Immunofluorescence staining was used to detect the expression of CD16， CD206， and high-mobility group box 1 （HMGB1）. Western blot analysis was performed to measure the protein expression of CD16， inducible nitric oxide synthase （iNOS）， CD206， arginase （Arg）， and proteins related to the SIRT1/HMGB1/nuclear factor-κB （NF-κB） signaling pathway. ResultsIn vivo experiments showed that， compared with the sham-operated group， the model group exhibited reduced platform crossings and time spent in the target quadrant （P<0.01）， prolonged escape latency， increased hippocampal neuronal apoptosis （P<0.01）， and obvious hippocampal damage. The expression levels of IL-6， TNF-α， IL-10， CD16， and iNOS in brain tissues were significantly elevated （P<0.01）， while CD206 and Arg protein expression showed an increasing trend without statistical significance. Compared with the model group， all AR-treated groups significantly increased platform crossings and target quadrant time （P<0.05， P<0.01）， alleviated hippocampal damage， reduced escape latency and neuronal apoptosis， downregulated the expression of TNF-α， IL-6， CD16， and iNOS （P<0.05， P<0.01）， and upregulated the expression of IL-10， CD206 and Arg （P<0.05， P<0.01）. In vitro experiments demonstrated that， compared with the blank control group， the Aβ_25-35 group showed increased fluorescence intensity of CD206， CD16， and HMGB1， as well as elevated protein expression of iNOS and CD16 （P<0.01）， while CD206 and Arg protein expression exhibited an increasing trend without statistical significance. After S-AR intervention， CD206 fluorescence intensity and the protein expression of Arg and CD206 were significantly increased （P<0.01）， whereas the fluorescence intensity of CD16 and HMGB1 and the protein expression of iNOS and CD16 were significantly decreased （P<0.01）. These effects were reversed by EX527 （P<0.05， P<0.01）. Furthermore， compared with the blank control group， the Aβ_25-35 group showed significantly increased cytoplasmic HMGB1 expression and p-p65/p65 ratio （P<0.01）， along with significantly decreased SIRT1 and nuclear HMGB1 expression （P<0.01）. In contrast， the S-AR group exhibited opposite trends compared with the Aβ_25-35 group， and the regulatory effects of S-AR on these proteins were reversed by EX527 （P<0.01）. ConclusionAR exerts neuroprotective effects in AD model rats by regulating microglial polarization and alleviating neuroinflammation， potentially through modulation of the SIRT1/HMGB1/NF-κB signaling pathway.

Background In 2021, chronic obstructive pulmonary disease (COPD) emerged as the forth leading cause of death in the world. However, the impact of air pollutants on COPD is still inconsistent across current studies. Objective To analyze the relationship between ambient sulfur dioxide (SO₂) exposure and hospital admissions for COPD in Lanzhou, and to examine the modified effects of SO₂ across different genders, age groups, and seasons. Methods A total of 20718 hospital admission records for COPD were collected from Lanzhou between 2016 and 2020, alongside synchronized data on SO₂ concentration and meteorological variables. A generalized additive model integrated with a distributed lag nonlinear model was used to assess the relationship and the lag effects between SO₂ exposure and COPD admissions. Potential confounders, including meteorological factors, day-of-the-week effect, and holidays, were controlled for, with a maximum lag period set at 7 d. Two-pollutant models and sensitivity analyses were conducted to ensure robustness. Results are expressed as relative risks (RR) with 95% confidence intervals (95%CI). Results During the study period, the average daily number of COPD admissions was 11.34±7.03. The average mass concentration of SO₂ was (23.72±12.35) μg·m⁻³. SO₂ exposure was positively correlated with COPD admissions; specifically, each 10 μg·m⁻³ increase in SO₂ concentration was associated with an RR of 1.440 (95%CI: 1.317, 1.573). Stratified analyses found that at a cumulative lag of 7 d, the RRs were higher among females, individuals aged ≥65 years, and during the cold season. Conversely, no significant increase in COPD admission risk related to SO₂ was observed during the warm season. For every 10 μg·m⁻³ increase in SO₂ concentration, the RR was 1.483 (95%CI: 1.311, 1.678) for females, 1.441 (95%CI: 1.311, 1.583) for those aged > 65 years， and 1.595 (95%CI: 1.313, 1.937) during the cold season. Conclusion Short-term exposure to ambient SO₂ exposure in Lanzhou is associated with an increased risk of COPD admission. The association is more pronounced among females, the elderly (aged> 65 years) and during the cold season.

Purpose: Metastatic rectal cancer (mRC) is a highly lethal and complex disease that demands a multidisciplinary treatment approach. However, the clinical effectiveness of radiotherapy (RT) for de novo mRC remains controversial and uncertain. Methods: This retrospective cohort study examined medical records from Kaohsiung Chang Gung Memorial Hospital for patients with histologically confirmed de novo mRC diagnosed between January 2015 and December 2020. All patients received standard systemic therapy and radical surgery when feasible. The primary outcome, overall survival (OS), was assessed using the Kaplan-Meier method. Multivariable analysis was performed using a Cox regression model. Results: Among 271 patients included in the analysis, 117 received RT and 154 did not. The median OS was significantly longer in the RT group compared with the non-RT group (27.8 months vs. 21.9 months; P=0.046). Multivariate analysis identified several independent predictors of OS: age ≥65 years (hazard ratio [HR], 1.69; 95% confidence interval [CI], 1.26–2.27; P=0.001), primary tumor resection (HR, 2.62; 95% CI, 1.90–3.61; P<0.001), M1b or M1c disease (HR, 1.97; 95% CI, 1.44–2.69; P<0.001), and receipt of RT (HR, 1.41; 95% CI, 1.02–1.94; P=0.036). Conclusion RT significantly improves OS in patients with mRC, underscoring its role in treatment strategies. These findings support its inclusion in therapeutic protocols and highlight the need for larger, multicenter trials to confirm and extend these results.

Objective: To analyze the etiologic distribution of difficult crossmatching and the characteristics of red blood cell antibodies, to summarize compatible transfusion strategies based on serological abnormalities, and to evaluate red blood cell transfusion efficacy and changes in bilirubin levels before and after transfusion. Methods: A retrospective analysis was conducted on difficult crossmatching cases handled by the Department of Blood Transfusion of our hospital from January 2024 to December 2025. Cases that met the criteria for difficult crossmatching determination and had complete data were included in the analysis of the causes and antibody distribution. Patients who completed red blood cell transfusion and had complete hemoglobin (Hb) data before and within 24 hours after transfusion were included in the exploratory subgroup analysis of transfusion efficacy; among them, those who also had total bilirubin and indirect bilirubin data before and after the corresponding transfusion event were included in the bilirubin analysis. According to the main serological abnormal manifestations before transfusion and the actual compatible transfusion management pathways, the cases included in the exploratory subgroup analysis were divided into three groups: the alloantibody-related difficult crossmatching group, the autoantibody-related or autoantibody combined with alloantibody-related difficult crossmatching group, and the ABO blood group identification abnormality-related difficult crossmatching group. The Hb levels before and after transfusion, the Hb increase after transfusion of each unit of red blood cells, and the changes in bilirubin levels before and after transfusion were compared among the groups. Results: A total of 322 difficult crossmatching cases met the predefined criteria, of which 287 were included in the analysis of causes and antibody distribution. There were 183 cases of alloantibody-related difficult crossmatching (63.76%), 54 cases related to inconsistency between ABO forward and reverse typing (18.82%), 44 cases related to autoantibodies (15.33%), and 6 cases related to interference from anti-CD38 monoclonal antibody drugs (2.09%). Among the 183 alloantibody-related cases, 79 cases had only a single alloantibody detected, among which antibodies of the Rh blood group system accounted for 49.37% (39/79). Among single alloantibodies, anti-E was detected most frequently, with 35 cases (44.30%), followed by anti-M with 19 cases (24.05%) and anti-Le with 13 cases (16.46%). A total of 109 cases were included in the exploratory subgroup analysis of transfusion efficacy, including 76 cases in the alloantibodyrelated difficult crossmatching group, 17 cases in the autoantibody-related or autoantibody combined with alloantibody-related difficult crossmatching group, and 16 cases in the ABO blood group identification abnormality-related difficult crossmatching group. The sex distribution and history of previous transfusion differed between cases included in and not included in this analysis. The Hb levels after transfusion in all three groups were higher than those before transfusion, and the differences were statistically significant (P<0.05). The Hb increase per unit of red blood cells did not differ significantly among the three groups (P=0.086). Among 73 cases with paired total and indirect bilirubin data corresponding to the transfusion events, the comparison of changes in total bilirubin among the three groups showed no statistically significant difference (P=0.864), and the comparison of changes in indirect bilirubin among the three groups also showed no statistically significant difference (P=0.914). Conclusion: Alloantibody-related factors were the main causes of difficult crossmatching in this study. Among single alloantibodies, Rh blood group system antibodies, especially anti-E, were relatively common. In the included exploratory subgroup, after individualized compatible transfusion based on the causes of difficult crossmatching, antibody specificities, and crossmatching results, Hb levels were higher after transfusion than before transfusion in all three groups. Within the scope of this study, the magnitude of bilirubin changes did not differ significantly among the different types of difficult crossmatching.

In 1929, George Soulié de Morant and Paul Ferreyrolles co-authored their first acupuncture-moxibustion paper titled "L' Acuponcture en Chine vingt siècles avant J.-C. et la réflexothérapie moderne", greatly advancing the development of acupuncture-moxibustion in Europe. Their paper systematically explains the holistic view and the concept of yin-yang balance in traditional Chinese medicine, describes the techniques of acupuncture and moxibustion, innovatively classifies acupuncture-moxibustion as "reflexotherapy", organizes the effects of certain acupuncture points illustrated on human acupoint atlas; and for the first time, it summarizes the correspondence between acupuncture points and Weihe trigger points. In the historical background of the neo-Hippocratic movement, they used the existing theories at that time to explain acupuncture, and adopted the analogical medicine to explore the mechanisms of acupuncture-moxibustion, which gradually initiated the modern era of acupuncture-moxibustion in France. Such research method is conducive to reducing the unfamiliarity of acupuncture-moxibustion among westerners, deepening their understanding of its theories and therapeutic effect, and also integrating it with other medical research. It breaks through the limitations of traditional theories and obtains the self-improvement and progress.
Humans ; Moxibustion/history* ; Acupuncture Therapy/history* ; China ; History, Ancient ; History, 20th Century ; Acupuncture/history* ; Reflexotherapy/history* ; Acupuncture Points ; History, 19th Century ; Medicine, Chinese Traditional/history*

Process analytical technology(PAT) is a key means for digital transformation and upgrading of the traditional Chinese medicine(TCM) manufacturing process, serving as an important guarantee for consistent and controllable TCM product quality. Near-infrared(NIR) spectroscopy has become the core technology for measuring the TCM manufacturing process. By incorporating NIR spectroscopy into PAT and starting from the construction of a smart platform for the TCM manufacturing process, this paper systematically described the development history and innovative application of the combination of NIR spectroscopy with chemometrics in measuring the TCM manufacturing process by the research team over the past two decades. Additionally, it explored the application of a validation method based on accuracy profile(AP) in the practice of NIR spectroscopy. Furthermore, the software development progress driven by NIR spectroscopy supported by modeling technology was analyzed, and the prospect of integrating NIR spectroscopy in smart factory control platforms was exemplified with the construction practices of related platforms. By integrating with the smart platform, NIR spectroscopy could improve production efficiency and guarantee product quality. Finally, the prospect of the smart platform application in measuring the TCM manufacturing process was projected. It is believed that the software development for NIR spectroscopy and the smart manufacturing platform will provide strong technical support for TCM digitalization and industrialization.
Spectroscopy, Near-Infrared/methods* ; Drugs, Chinese Herbal/analysis* ; Software ; Medicine, Chinese Traditional ; Quality Control

This study aims to investigate the molecular mechanism by which naringin alleviates cerebral ischemia/reperfusion(CI/R) injury through DRP1/LRRK2/MCU signaling axis. A total of 60 SD rats were randomly divided into the sham group, the model group, the sodium Danshensu group, and low-, medium-, and high-dose(50, 100, and 200 mg·kg~(-1)) naringin groups, with 10 rats in each group. Except for the sham group, a transient middle cerebral artery occlusion/reperfusion(tMCAO/R) model was established in SD rats using the suture method. Longa 5-point scale was used to assess neurological deficits. 2,3,5-Triphenyl tetrazolium chloride(TTC) staining was used to detect the volume percentage of cerebral infarction in rats. Hematoxylin-eosin(HE) staining and Nissl staining were employed to assess neuronal structural alterations and the number of Nissl bodies in cortex, respectively. Western blot was used to determine the protein expression levels of B-cell lymphoma-2 gene(Bcl-2), Bcl-2-associated X protein(Bax), cleaved cysteine-aspartate protease-3(cleaved caspase-3), mitochondrial calcium uniporter(MCU), microtubule-associated protein 1 light chain 3(LC3), and P62. Mitochondrial structure and autophagy in cortical neurons were observed by transmission electron microscopy. Immunofluorescence assay was used to quantify the fluorescence intensities of MCU and mitochondrial calcium ion, as well as the co-localization of dynamin-related protein 1(DRP1) with leucine-rich repeat kinase 2(LRRK2) and translocase of outer mitochondrial membrane 20(TOMM20) with LC3 in cortical mitochondria. The results showed that compared with the model group, naringin significantly decreased the volume percentage of cerebral infarction and neurological deficit score in tMCAO/R rats, alleviated the structural damage and Nissl body loss of cortical neurons in tMCAO/R rats, inhibited autophagosomes in cortical neurons, and increased the average diameter of cortical mitochondria. The Western blot results showed that compared to the sham group, the model group exhibited increased levels of cleaved caspase-3, Bax, MCU, and the LC3Ⅱ/LC3Ⅰ ratio in the cortex and reduced protein levels of Bcl-2 and P62. However, naringin down-regulated the protein expression of cleaved caspase-3, Bax, MCU and the ratio of LC3Ⅱ/LC3Ⅰ ratio and up-regulated the expression of Bcl-2 and P62 proteins in cortical area. In addition, immunofluorescence analysis showed that compared with the model group, naringin and positive drug treatments significantly decreased the fluorescence intensities of MCU and mitochondrial calcium ion. Meanwhile, the co-localization of DRP1 with LRRK2 and TOMM20 with LC3 in cortical mitochondria was also decreased significantly after the intervention. These findings suggest that naringin can alleviate cortical neuronal damage in tMCAO/R rats by inhibiting DRP1/LRRK2/MCU-mediated mitochondrial fragmentation and the resultant excessive mitophagy.
Animals ; Rats, Sprague-Dawley ; Reperfusion Injury/genetics* ; Flavanones/administration & dosage* ; Rats ; Dynamins/genetics* ; Male ; Brain Ischemia/genetics* ; Protein Serine-Threonine Kinases/genetics* ; Signal Transduction/drug effects* ; Humans ; Drugs, Chinese Herbal/administration & dosage*

OBJECTIVE: To assess health equity in the Yangtze River region to improve understanding of the correlation between hand, foot, and mouth disease (HFMD) and socioeconomic factors. METHODS: From 2014-2016, data on HFMD incidence, population statistics, economic indicators, and meteorology from 26 cities along the Yangtze River were analyzed. A multi-city random-effects meta-analysis was performed to study the relationship between temperature and HFMD transmission, and health equity was assessed with respect to socio-economic impact. RESULTS: Over the study period, 919,458 HFMD cases were reported, with Shanghai (162,303) having the highest incidence and Tongling (5,513) having the lowest. Males were more commonly affected (male-to-female ratio, 1.49:1). The exposure-response relationship had an M-shaped curve, with two HFMD peaks occurring at 4 °C and 26 °C. The relative risk had two peaks at 1.30 °C (1.834, 95% CI: 1.204-2.794) and 31.4 °C (1.143, 95% CI: 0.901-1.451), forming an M shape, with the first peak higher than the second. The most significant impact of temperature on HFMD was observed between -2 °C and 18.1 °C. The concentration index (0.2463) indicated moderate concentration differences, whereas the Theil index (0.0418) showed low inequality in distribution. CONCLUSION The incidence of HFMD varied across cities, particularly with changes in temperature. Economically prosperous areas showed higher risks, indicating disparities. Targeted interventions in these areas are crucial for mitigating the risk of HFMD.
Female ; Humans ; Male ; China/epidemiology* ; Cities/epidemiology* ; Hand, Foot and Mouth Disease/transmission* ; Incidence ; Risk Factors ; Temperature

Objective:To investigate the effect of abdominal circumference on intestinal radiation dose volume and acute intestinal toxicity in pelvic intensity modulated radiation therapy for rectal cancer.Methods:A total of 150 patients with locally advanced rectal cancer (LARC) who received adjuvant and neoadjuvant concurrent chemoradiotherapy at the Affiliated Cancer Hospital of Guizhou Medical University from March 2023 to January 2025 were enrolled, including 82 cases of adjuvant radiotherapy and 68 cases of neoadjuvant radiotherapy. All patients underwent radiotherapy CT simulation positioning in the standard mode of prone position with abdominal board padding and bladder filling. Intestinal toxicity was categorized as a binary variable based on the occurrence of ≥2 grade acute intestinal toxicity. Linear and logistic regression models were used to analyze the factors influencing intestinal radiation dose volumes (V 10, V 20, V 30, V 40) and acute intestinal toxicity in LARC patients. Generalized additive models and piecewise linear and logistic regression analyses were employed to examine the threshold effects of abdominal circumference on intestinal radiation dose volumes and acute intestinal toxicity. The threshold value for abdominal circumference was determined based on the upper limit of the 95% CI for the threshold. A difference test was used to validate the differences in intestinal radiation dose volume and acute intestinal toxicity between small and medium-to-large abdominal circumferences. Results:Univariate analysis showed that, gender, body mass, abdominal circumference, planning target volume (PTV), intestinal volume were all influencing factors for the radiation dose volumes (V 10, V 20, V 30, V 40) of each intestinal segment of patients with LARC undergoing adjuvant radiotherapy (all P<0.05). Body mass, abdominal circumference, intestinal volume were all influencing factors for the radiation dose volumes (V 10, V 20, V 30, V 40) of each intestinal segment of patients with LARC undergoing neoadjuvant radiotherapy (all P<0.05). Body mass index (BMI), abdominal circumference, intestinal volume and individual intestinal radiation volumes (V 10, V 20, V 30, V 40) were all influencing factors for the acute intestinal toxicity of patients with LARC undergoing adjuvant radiotherapy (all P<0.05). Body mass, BMI, abdominal circumference, multiple intestinal radiation dose volumes (V 20, V 30, V 40) were all influencing factors for the acute intestinal toxicity of patients with LARC undergoing neoadjuvant radiotherapy (all P<0.05). Multivariate analysis showed that, abdominal circumference (V 10: β=-1.01, 95% CI: -1.68--0.33, P=0.004; V 20: β=-0.94, 95% CI: -1.28--0.60, P<0.001; V 30: β=-0.58, 95% CI: -0.82--0.34, P<0.001; V 40: β=-0.41, 95% CI: -0.60--0.23, P<0.001) was an independent influencing factor for the radiation dose volume of each intestinal segment of patients with LARC undergoing adjuvant radiotherapy. Abdominal circumference (V 10: β=-0.92, 95% CI: -1.62--0.22, P=0.010; V 20: β=-0.84, 95% CI: -1.11--0.57, P<0.001; V 30: β=-0.42, 95% CI: -0.57--0.28, P<0.001; V 40: β=-0.30, 95% CI: -0.41--0.19, P<0.001) was an independent influencing factor for the radiation dose volume of each intestinal segment of patients with LARC undergoing neoadjuvant radiotherapy. Abdominal circumference ( OR=0.86, 95% CI: 0.78-0.95, P=0.002) was an independent influencing factor for the acute intestinal toxicity of patients with LARC undergoing adjuvant radiotherapy. Abdominal circumference ( OR=0.87, 95% CI: 0.79-0.96, P=0.004) was an independent influencing factor for the acute intestinal toxicity of patients with LARC undergoing neoadjuvant radiotherapy. The generalized additive model revealed a nonlinear relationship between abdominal circumference and intestinal radiation dose volume and acute intestinal toxicity of adjuvant radiotherapy patients. Further segmented regression analysis results showed that there was a threshold effect between abdominal circumference and intestinal radiation dose volume (V 10, V 20, V 30, V 40) and acute intestinal toxicity. The inflection point values between abdominal circumference and intestinal radiation dose volume V 10, V 20, V 30, V 40 in LARC patients undergoing adjuvant radiotherapy were all 71.9 cm; the inflection point values between abdominal circumference and the intestinal radiation dose volume V 10, V 20, V 30, V 40 in LARC patients undergoing neoadjuvant radiotherapy were 69.0, 69.0, 69.0, 68.6 cm, respectively; The inflection point values between abdominal circumference and acute intestinal toxicity in LARC patients undergoing adjuvant radiotherapy and neoadjuvant radiotherapy were 71.9, 69.0 cm, respectively. Based on the upper limit of the 95% CI threshold, the cutoff values for small and medium-to-large abdominal circumferences for patients undergoing adjuvant and neoadjuvant radiotherapy were set at 76.1, 71.9 cm, respectively. In patients undergoing adjuvant radiotherapy, the levels of intestinal radiation dose volume V 10 [ (7.65±2.29) cm 3vs. (5.88±2.68) cm 3, t=2.76, P=0.007], V 20 [ (4.28±1.27) cm 3vs. (2.72±1.31) cm 3, t=4.81, P<0.001], V 30 [ (2.42±1.07) cm 3vs. (1.37±0.76) cm 3, t=4.95, P<0.001], V 40 [ (1.69±0.74) cm 3vs. (0.92±0.58) cm 3, t=4.93, P<0.001] in the small abdominal circumference group ( n=22) were significantly higher than those in patients with medium-to-large abdominal circumferences ( n=60) ; In patients undergoing neoadjuvant radiotherapy, patients with small abdominal circumferences ( n=11) had significantly higher V 20 [ (3.09±0.84) cm 3vs. (2.28±1.17) cm 3, t=2.17, P=0.033], V 30 [1.44 (1.22, 1.53) cm 3vs. 0.91 (0.56, 1.22) cm 3, Z=-3.04, P=0.002], V 40 [0.93 (0.84, 1.09) cm 3vs. 0.44 (0.30, 0.81) cm 3, Z=-3.19, P=0.001] than patients with medium-to-large abdominal circumferences ( n=57). In patients receiving adjuvant radiotherapy and neoadjuvant radiotherapy, there were statistically significant differences in acute intestinal toxicity between patients with small abdominal circumferences and with medium-to-large abdominal circumferences ( χ2=10.46, P=0.001; χ2=8.13, P=0.004) . Conclusions:In the standard mode (prone position with abdominal board padding and bladder filling), abdominal circumference is an independent factor influencing the intestinal radiation dose volume and acute intestinal toxicity in rectal cancer radiotherapy patients. There is a significant non-linear threshold effect between abdominal circumference and different levels of intestinal radiation dose volume and acute intestinal toxicity. The impact of abdominal circumference on intestinal radiation dose volume and toxicity differs significantly before and after the inflection point value. Patients with smaller abdominal circumferences not only fail to achieve the expected benefits under the current standard radiotherapy regimen but also face higher risks of intestinal radiation dose volume and toxicity.