OBJECTIVE: To investigate the distribution characteristics of polymorphonuclear neutrophil (PMN) in the lungs during the early stage of severe burns and the mechanism of neutrophil elastase (NE) promoting lung injury. METHODS: 6-8-week-old male C57BL/6J mice were selected for the experiments. A 30% total body surface area (TBSA) III degree burn mouse model was established (severe burn group); the Sham-injury group was treated with 37 centigrade water. In the sodium sivelestat intervention group (SV intervention group), NE competitive inhibitor, sivelestat, 100 mg/kg, was injected via tail vein immediately after injury, while other groups received an equal volume of saline. Ten mice were harvested from each group to observe survival for 72 hours. Respiratory function tests were tested at 0 (immediate), 3, 6, 12, and 24 hours after molding. hematoxylin-eosin (HE) and immunohistochemical staining were used to observe lung tissue structure, inflammatory changes and PMN infiltration. The PMN absolute count in mice lung tissue was detected buy flow cytometry. At 6, 12, and 24 hours after molding, PMN counts and the concentration of NE [enzyme linked immunosorbent assay (ELISA)] in peripheral blood plasma, lung tissue, and bronchoalveolar lavage fluid (BALF) were detected. RESULTS: (1) HE staining results showed that compared with the Sham-injury group, the lungs of mice in the severe burn group showed inflammatory changes and PMN infiltration, with more significant changes at 6 hours. Immunohistochemistry results also confirmed that the expression of NE protein released from PMN significantly increased after 6 hours of severe burn injury [(3.79±0.62)% vs. (0.18±0.05)%, t = 11.56, P < 0.01]. (2) Compared with the Sham-injury group, the number of PMN and the concentration of NE in the peripheral blood and lung tissues in the severe burn group were significantly increased (F values were 13.709, 55.350 and 29.890, 13.286, respectively, all P < 0.01), peaking at 6 hours [plasma PMN count (×10⁹/L): 2.92±1.01 vs. 0.92±0.29, lung tissue PMN absolute count (cells): 48 788.03±11 833.91 vs. 1 516.72±415.35, plasma NE (ng/L): 24 522.71±3 842.92 vs. 7 009.34±4 067.86, lung tissue NE (ng/L): 262 189.04±9 695.13 vs. 65 026.03± 16 016.31, all P < 0.01]. The number of PMN in the lung of severely burned mice was highly correlated with NE concentration (r = 0.892, P < 0.001). There was no significantly difference in the PMN absolute count in the BALF of mice between the Sham-injury group and severe burn group (F = 1.403, P > 0.05). The Sham-injury group and severe burn group contained a small amount of NE in the BALF, and the concentration of NE in the BALF of the severely burned 6 hours and 12 hours groups were significantly higher than those of the Sham-injury group (ng/L: 328.58±158.10, 415.30±240.89 vs. 61.95±15.80, both P < 0.05). (3) Kaplan-Meier survival curve showed that the 72-hour survival rate of mice in the SV intervention group was significantly higher than that in the severe burn group (100% vs. 10%, Log-Rank test: χ² = 19.12, P < 0.001). (4) Compared with the Sham-injury group, all lung function indices of the severe burn group decreased significantly. All lung function indices of SV intervention group improved gradually over time, which were significantly better than those of the severe burn group. (5) Compared with the Sham-injury group, the PMN absolute count in lung tissue and the concentration of NE in plasma and lung tissue were significantly higher in the SV intervention group (F values were 46.709, 3.535, 32.701, respectively, all P < 0.05), with a peak at 6 hours. Compared with the severe burn group, the SV intervention group had a higher PMN absolute count in lung tissue (cells: 8 870.80±7 013.89 vs. 25 974.92±22 240.8, P < 0.05), and higher plasma and lung tissue NE concentrations (ng/L: 14 955.94±3 944.41 vs. 21 972.75±4 573.05, 81 956.87±38 658.35 vs. 168 182.30±83 513.91, both P < 0.01) were significantly decreased. CONCLUSIONS In the early stage of severe burns, there is a significant infiltration of PMN into the lungs. The NE promotes lung injury in the early stage of severe burn, and improve lung injury by inhibiting the action of NE.
Animals ; Burns/metabolism* ; Leukocyte Elastase/metabolism* ; Male ; Mice, Inbred C57BL ; Mice ; Neutrophils/metabolism* ; Lung/metabolism* ; Disease Models, Animal ; Neutrophil Infiltration ; Lung Injury/metabolism* ; Glycine/analogs & derivatives* ; Sulfonamides

Objective:To clarify the safety, repair rate, durability, and risk factors for recurrent mitral regurgitation(MR) in patients with Barlow disease(BD) who total thoracoscopic minimally invasive mitral valvuloplasty(TMVP).Methods:Clinical data, mid-term and long-term outcomes of BD patients who underwent TMVP at Guangdong Provincial People's Hospital from January 2009 to June 2022 were retrospectively analyzed. Patients were divided into a group with no MR recurrence(group A) and a group with MR recurrence(group B) according to whether recurrent MR appeared in the postoperative period, and the data of the two groups of patients were compared with each other for the risk factor analysis.Results:The repair rate of TMVP was 98.4%, and no patient died perioperatively. The median follow-up time was 3.1(1.7, 5.2) years, the follow-up rate was 95.8%, and there was no patient died. As of March 2023, 112 patients developed no recurrent MR(group A), 11 patients developed recurrent MR(group B), and 2 patients in group B underwent repeated mitral valve surgery. The left atrial diameter(LAD) and left ventricular end-systolic diameter(LVESD) were higher in group B than in group A patients[LAD: (50.9±7.7)mm vs.(43.7±8.7)mm, P=0.009; LVESD: (37.1±5.5)mm vs.(33.2±4.7)mm, P=0.011], and the percentage of tendon cord rupture was higher in group B than in group A( P=0.022), while the rest of the baseline data were not statistically significant. There was no statistically significant difference between two groups in terms of the use of different surgical techniques, aortic cross-clamp time, cardiopulmonary bypass time, and operative time. Postoperative LAD, postoperative LVESD, and postoperative left ventricular end-diastolic diameter of group B patients were higher than those of group A( P<0.05). There was no statistically significant difference in perioperative and long-term complication rates between the two groups. Multifactorial Cox regression analysis revealed that advanced age( HR=1.049, 95% CI: 0.997-1.103, P=0.066) and large preoperative LVESD( HR=1.168, 95% CI: 1.053-1.295, P=0.003) were the risk factors for postoperative recurrence MR. Conclusion:Total thoracoscopic minimally invasive BD repair is safe, which has a high success rate and good long-term results. Advanced age and large preoperative LVESD are risk factors for recurrent MR in the long term.

Objective:To clarify the safety, repair rate, durability, and risk factors for recurrent mitral regurgitation(MR) in patients with Barlow disease(BD) who total thoracoscopic minimally invasive mitral valvuloplasty(TMVP).Methods:Clinical data, mid-term and long-term outcomes of BD patients who underwent TMVP at Guangdong Provincial People's Hospital from January 2009 to June 2022 were retrospectively analyzed. Patients were divided into a group with no MR recurrence(group A) and a group with MR recurrence(group B) according to whether recurrent MR appeared in the postoperative period, and the data of the two groups of patients were compared with each other for the risk factor analysis.Results:The repair rate of TMVP was 98.4%, and no patient died perioperatively. The median follow-up time was 3.1(1.7, 5.2) years, the follow-up rate was 95.8%, and there was no patient died. As of March 2023, 112 patients developed no recurrent MR(group A), 11 patients developed recurrent MR(group B), and 2 patients in group B underwent repeated mitral valve surgery. The left atrial diameter(LAD) and left ventricular end-systolic diameter(LVESD) were higher in group B than in group A patients[LAD: (50.9±7.7)mm vs.(43.7±8.7)mm, P=0.009; LVESD: (37.1±5.5)mm vs.(33.2±4.7)mm, P=0.011], and the percentage of tendon cord rupture was higher in group B than in group A( P=0.022), while the rest of the baseline data were not statistically significant. There was no statistically significant difference between two groups in terms of the use of different surgical techniques, aortic cross-clamp time, cardiopulmonary bypass time, and operative time. Postoperative LAD, postoperative LVESD, and postoperative left ventricular end-diastolic diameter of group B patients were higher than those of group A( P<0.05). There was no statistically significant difference in perioperative and long-term complication rates between the two groups. Multifactorial Cox regression analysis revealed that advanced age( HR=1.049, 95% CI: 0.997-1.103, P=0.066) and large preoperative LVESD( HR=1.168, 95% CI: 1.053-1.295, P=0.003) were the risk factors for postoperative recurrence MR. Conclusion:Total thoracoscopic minimally invasive BD repair is safe, which has a high success rate and good long-term results. Advanced age and large preoperative LVESD are risk factors for recurrent MR in the long term.

Objective To retrospectively analyze the blood use of transfusion-dependent thalassemia(TDT)patients in 9 designated transfusion medical institutions from 2018 to 2023 in Nanning,and to evaluate the effect of"three designated"blood transfusion mode(hereby means TDT patients undergoing blood transfusion in designated transfusion medical institu-tions regularly)and"collection-based-supply"blood management mode on blood security of TDT patients.Methods The"three designated"blood transfusion mode was implemented to ensure that TDT patients registered in the local household registration(referred to as the"register")obtain the rights and interests of outpatient transfusion and blood security of des-ignated medical institutions.The"collection-based-supply"blood management mode was implemented to assess the blood needs of"register"TDT patients and meet their needs to the maximum extent according to the blood inventory(collection).Results From 2018 to 2023,the total blood supply of"register"TDT patients was 10.37%of the total red blood supply of all medical institutions(138 509.5 U/1 335 788.0 U),with the highest proportion of type O blood as 46.34%(64 181.0 U/138 509.5 U)and the lowest proportion of type AB blood as 3.85%(5 331.0 U/138 509.5 U).In 2018,9 transfusion medical institutions were designated for TDT patients.There were a total of 766 TDT patients in the register,with the per ca-pita annual blood transfusion volume increased from20.28 U(15 531.0 U/766 patients)in2018 to36.01 U(27 586.0 U/766 patients)in 2023,maintaining a positive growth every year(30.26%,4.94%,11.71%,8.61%,4.94%and 7.10%).Conclusion The"three designated"blood transfusion mode and the"collection-based-supply"blood management mode can effectively guarantee the blood supply of TDT patients.

Objectives:To investigate the screening status of warning signs for mental and behavioral development (WS) and influencing factors of infants and young children (IYC) in poverty eliminated regions of Henan Province.Methods:This study was a cross-sectional study. A total of 15 680 IYC aged 6-23 months from 51 poverty eliminated counties in Henan province from June to September of 2023 were selected through a multi-stage random sampling method. IYC′s early warning signs were screened using the WS checklist (WSC). Children′s socio-demographic characteristics, maternal information, birth status, and illness conditions such as fever and diarrhea within 2 weeks were measured through a uniformly designed questionnaire. All participants also received the measurement of height, weight, and hemoglobin concentration level. Logistic regression model was used to explore the influencing factors of positive WSC and conducted sensitivity analyses.Results:Among the sample of 15 680 IYC, there were 8 462 boys (53.97%) and 7 218 girls (49.03%), with their age of (15±5) months. A total of 291 (1.86%) IYC were positive in WSC. Parenting risk ( OR=5.07, 95% CI 3.93-6.52, P<0.001) and preterm birth ( OR=1.63, 95% CI 1.06-2.52, P=0.027) were both positively associated with the odds of WSC′s positivity. Being girls ( OR=0.66, 95% CI 0.52-0.85, P=0.001), age (12-17 months, OR=0.47, 95% CI 0.35-0.62, P<0.001; 18-23 months, OR=0.40, 95% CI 0.30-0.54, P<0.001), and maternal educational level (junior high school, OR=0.46, 95% CI 0.32-0.66, P<0.001; senior high school or vocational high school, OR=0.35, 95% CI 0.23-0.56, P<0.001; college and above, OR=0.36, 95% CI 0.23-0.57, P<0.001) were all negatively associated with the risk of WSC′s positivity. Sensitivity analyses demonstrated that, after excluding anemic children, the association between preterm birth and WSC′s positivity was not significant ( OR=1.54, 95% CI 0.95-2.49, P=0.081). Despite this situation, being girls, age and maternal educational level were still negatively associated with the odds of WSC′s positivity (all P<0.05); preterm birth, parenting risk were remained positive associated with the risk of WSC′s positivity (all P<0.05) either by excluding children with protein-energy malnutrition or 2-week morbidity, or using prevalence ratio instead of OR. Conclusions:Among the IYC in poverty eliminated regions of Henan Province, the risk of positivity of WSC was higher for those IYC with parenting risk, preterm birth, boys, younger age, and lower maternal education level. These influencing factors, such as gender, age, preterm birth, parenting risk and maternal educational level, were in certain stability across different IYC characteristics and estimation models.

Objective To develop a self-assessment scale for medication literacy in patients with coronary heart disease comorbidity diabetes and to test its reliability and validity.Methods According to medication literacy theory model,the initial scale was formed through literature review,the qualitative interview and expert inquiry.Cognitive interview was used to optimize the expression of item text.421 patients with coronary heart disease comorbidity diabetes in a tertiary hospital in Zhejiang province from November 2022 to April 2023 were selected to investigate the reliability and validity of the scale by convenience sampling.Results The self-assessment scale of drug literacy for coronary heart disease comorbidity diabetes mellitus included 23 items in 5 dimensions including acquisition,understanding,communication,evaluation and calculation.The total Cronbach's α coefficient of the scale was 0.911;the retest reliability was 0.948;the average content validity index was 0.997;the correlation coefficients between each dimension and total score of the scale and the calibration scale ranged from 0.485 to 0.926.The exploratory factor analysis was employed to extract 5 common factors,and the cumulative variance contribution rate was 73.753％.Confirmatory factor analysis showed that the scale factor structure was stable.Conclusion The scale has good reliability and validity,and it can be used as an effective tool to evaluate the self-rated medication literacy level of patients with coronary heart disease comorbidity diabetes.

Objective To develop a self-assessment scale of home volume management for patients with chronic heart failure(CHF),and to test its reliability and validity.Methods With the self-care theory as the theoretical framework,the initial scale was developed through literature analysis,qualitative interview and expert consultation.A questionnaire survey was conducted on 598 patients with CHF who were treated or reviewed in a tertiary hospital in Hangzhou from September 2022 to January 2023 to test the reliability and validity of the scale.Results The exploratory factor analysis extracted 4 common factors with the cumulative variance contribution rate of 61.268％.The results of confirmatory factor analysis showed that the main evaluation indicators were all within the acceptable range of the judgment standard.The item-level content validity index ranged from 0.853 to 1.000;the scale-level content validity index/average was 0.951.The Cronbach's a coefficient,half reliability and retest reliability of the overall scale were 0.930,0.723 and 0.867,respectively.Conclusion The self-rating scale of home volume management for CHF patients has good reliability and validity,and it can effectively assess the level of home volume management for CHF patients.

Objective:To investigate the regulatory effects and mechanism of Nocardia rubra cell wall skeleton (Nr-CWS) on the biological function of human neutrophils. Methods:The experimental research method was used. Fifteen healthy adult volunteers (7 males and 8 females, aged 24 to 45 years) were recruited from Suzhou Physical Examination Center for physical examination from May to October 2022, the peripheral venous blood was collected, and neutrophils were extracted by immunomagnetic bead sorting. The cells were divided into normal control group without any treatment, Nr-CWS alone group treated with Nr-CWS of final mass concentration 60 ng/mL alone, endotoxin/lipopolysaccharide (LPS) alone group stimulated with LPS of final mass concentration 1 μg/mL alone, and LPS+Nr-CWS group stimulated with LPS first and then treated with Nr-CWS as before. After 1 h of culture, the chemotaxis distance, chemotactic cell percentage, chemotactic index, maximum chemotactic speed, and chemotactic function score of neutrophils were detected using the modified agarose chemotactic model; the proportion and fluorescence intensity of phagocytosis cells, the level of reactive oxygen species (ROS), the protein expression levels of granular protein CD35, CD66b, and CD63, and the concentrations of inflammatory cytokines of interleukin 2 (IL-2), IL-4, IL-6, IL-10, IL-17A, tumor necrosis factor alpha (TNF-α), and interferon-γ in cell culture supernatant were detected by flow cytometry. The number of samples in each group in the above experiments was 15. Data were statistically analyzed with analysis of variance for factorial design and independent sample t test. Results:After 1 h of culture, the chemotactic function score of cells in normal control group, Nr-CWS alone group, LPS alone group, and LPS+Nr-CWS group were 15.0, 14.5±0.5, 1.5±0.5, 12.0±1.5, respectively. Compared with those in normal control group, the chemotaxis distance, chemotactic cell percentage, chemotactic index, maximum chemotactic speed, and chemotactic function score of cells were significantly decreased in LPS alone group and LPS+Nr-CWS group (with t values of 18.36, 18.88, 54.28, 18.36, 46.77, 10.58, 14.74, 6.84, 10.58, and 4.24, respectively, P<0.05); compared with those in LPS alone group, the five chemotactic function indexes as above in LPS+Nr-CWS group were significantly increased (with t values of 11.47, 14.65, 11.62, 11.47, and 13.75, respectively, P<0.05). After 1 h of culture, compared with those in normal control group, the proportion and fluorescence intensity of phagocytosis cells were significantly increased in Nr-CWS alone group (with t values of 6.86 and 6.73, respectively, P<0.05), and the above two indexes were significantly decreased in LPS alone group (with t values of 7.35 and 22.72, respectively, P<0.05) and LPS+Nr-CWS group (with t values of 21.37 and 13.10, respectively, P<0.05). After 1 h of culture, compared with that in normal control group, the level of ROS of cells in LPS alone group was significantly increased ( t=6.64, P<0.05); compared with that in LPS alone group, the level of ROS of cells in LPS+Nr-CWS group was significantly decreased ( t=5.46, P<0.05). After 1 h of culture, compared with those in normal control group, the protein expressions of CD35, CD66b, and CD63 of cells were significantly increased in LPS alone group and LPS+Nr-CWS group (with t values of 16.75, 17.45, 10.82, 5.70, 19.35, and 15.37, respectively, P<0.05); compared with those in LPS alone group, the protein expressions of CD35, CD66b, and CD63 of cells were significantly decreased in LPS+Nr-CWS group (with t values of 4.92, 5.72, and 3.18, respectively, P<0.05). After 1 h of culture, compared with those in normal control group, the concentrations of IL-2, IL-4, IL-6, IL-10, IL-17A, TNF-α, and interferon-γ in cell culture supernatant were significantly increased in LPS alone group (with t values of 22.10, 9.50, 7.21, 10.22, 24.88, 8.43, and 47.48, respectively, P<0.05), and the concentrations of IL-6, IL-10, IL-17A, TNF-α, and interferon-γ in cell culture supernatant were significantly increased in LPS+Nr-CWS group (with t values of 4.68, 5.12, 8.02, 5.58, and 7.13, respectively, P<0.05); compared with those in LPS alone group, the concentrations of IL-2, IL-4, IL-6, IL-10, IL-17A, TNF-α, and interferon-γ in cell culture supernatant were significantly decreased in LPS+Nr-CWS group (with t values of 5.39, 2.83, 5.79, 2.90, 5.87, 4.88, and 39.64, respectively, P<0.05). Conclusions:Nr-CWS can enhance the phagocytosis ability of neutrophils in normal condition and improve the chemotactic function, ROS level, degranulation protein level, and inflammatory factor level of human neutrophils in infectious condition. Nr-CWS can enhance the anti-infection ability of human neutrophils by regulating its biological behavior in innate immunity.

Objective:To investigate the effect of neutrophils on T lymphocyte function in septic mice and the role of CD80/cytotoxic T lymphocyte antigen-4 (CTLA-4) signaling pathway in this modulated effects.Methods:① In vivo experiment: 6-8 weeks old male C57BL/6 mice were divided into sham operation group (Sham group, n = 20), Sham+CTLA-4 antibody treatment group (Sham+aCTLA-4 group, n = 20), cecal ligation and perforation (CLP) induced sepsis model group (CLP group, n = 30) and CLP+CTLA-4 antibody treatment group (CLP+aCTLA-4 group, n = 30) according to the random number table. CLP was used to reproduce mouse sepsis model. The mice in the Sham group were treated identically but their cecums were neither punctured nor ligated. In CTLA-4 antibody treatment groups, 50 μg CTLA-4 antibody was injected intraperitoneally 6 hours and 24 hours after the operation. Forty-eight hours after operation, 6 mice in Sham group and Sham+aCTLA-4 group, 14 mice in CLP group and CLP+aCTLA-4 group were randomly selected to detect the expression of CD69 in spleen. At the same time, spleen, bone marrow and peripheral blood were collected, and the expression of CD80 on neutrophils was detected by flow cytometry. The expression of CTLA-4 on the surface of T lymphocytes in spleen was detected by immunofluorescence and flow cytometry. The remaining mice in each group were used to observe the 96-hour survival after operation.② In vitro experiment 1: neutrophils were extracted from bone marrow of healthy mice and stimulated with LPS (1 mg/L) for 4, 8 and 12 hours respectively. The control group was added with the same amount of phosphate buffered saline (PBS) at each time point, and the expression of CD80 was detected at each time point.③ In vitro experiment 2: splenic T lymphocytes of healthy mice were extracted and divided into PBS control group, LPS group (final concentration of LPS 1 mg/L), neutrophil group and neutrophil+LPS group. In the latter two groups, the co-culture model of neutrophils and T lymphocytes was established, and then the corresponding treatment was given to detect the expression of CTLA-4 on the surface of T lymphocytes. With the above four groups as controls, CTLA-4 antibody treatment groups (final concentration of CTLA-4 antibody 50 mg/L) were set up respectively. After 48 hours, the level of interleukin-2 (IL-2) in the cell supernatant was detected by enzyme linked immunosorbent assay (ELISA). Results:① Results of in vivo experiment: compared with Sham group, the expression of CD80 on neutrophils in spleen, bone marrow and peripheral blood was significantly up-regulated, while the expression of CTLA-4 on the surface of T lymphocytes was significantly increased [(9.98±0.84)% vs. (3.48±0.64)%, P < 0.05]. It suggested that neutrophils may affect T lymphocytes function through CD80/CTLA-4 pathway in sepsis. Compared with CLP group, CTLA-4 antibody could significantly improve the 96-hour cumulative survival rate of CLP mice (56.25% vs. 18.75%, P < 0.05), and increase the expression of CD69 on the surface of T lymphocytes. It suggested that CTLA-4 antibodies might increase T lymphocytes activation in sepsis and improve survival. ② Results of in vitro experiment: with the prolongation of LPS stimulation, the expression of CD80 on neutrophils gradually increased in time-dependent manner as compared with PBS control group [4 hours: (6.35±0.40)% vs. (3.41±0.40)%, 8 hours: (8.57±0.64)% vs. (3.09±0.27)%, 12 hours: (19.83±1.06)% vs. (5.16±0.36)%, all P < 0.05]. Compared with PBS control group, the expression of CTLA-4 on CD4 +/CD8 + T lymphocytes was not significantly affected by LPS stimulation alone, but CTLA-4 was increased after co-culture with neutrophils [CD4 +: (4.92±0.30)% vs. (3.33±0.25)%, CD8 +: (4.26±0.21)% vs. (2.53±0.66)%, both P < 0.05], and the increased trend of CTLA-4 was more obvious after co-culture with LPS-stimulated neutrophils [CD4 +: (6.34±0.50)% vs. (3.33±0.25)%, CD8 +: (6.21±0.41)% vs. (2.53±0.66)%, both P < 0.05]. In the PBS control group and LPS group, CTLA-4 antibody had no significant effect on IL-2 secretion of T lymphocytes. Compared with PBS control group, co-culture with neutrophils could inhibit the secretion of IL-2 by T lymphocytes (ng/L: 1 938.00±68.45 vs. 2 547.00±218.00, P < 0.05), and the inhibitory effect of neutrophils stimulated by LPS was more obvious (ng/L: 1 073.00±34.39 vs. 2 547.00±218.00, P < 0.05). CTLA-4 antibodies could partially restore IL-2 secretion. In conclusion, after promoting the expression of CTLA-4 on the surface of T lymphocytes, neutrophils might mediate the inhibition of T lymphocytes function by reducing the production of IL-2. Conclusions:Neutrophils mediate T lymphocytes dysfunction in sepsis, and the CD80/CTLA-4 pathway plays an important role. The CTLA-4 antibody improves survival and T lymphocytes function in sepsis mice, which may be a new method of immunotherapy for sepsis.

Objective:To study the radiation dose rate and effective dose in ambient environment due to 125I seed implantation in the treatment of the patients suffering abdominal and pelvic tumors, so as to provide reference for occupational protection of different groups. Methods:Within 24 hours after operation, the radiation dose rate to 42 patients with abdominal and pelvic tumor with 125I seed implantation was monitored by using pocket dosimeter. The relationships between the total activity in the implanted particles and the measured dose rate, as well as between the implanted depth and the dose rate under the standard activity, were obtained by curve fitting. According to the formula, the relationship between the dose rate and the warning time was calculated. Results:The dose rates at 30 cm, 50 cm and 100 cm of vertical particle implantation site were (6.92±2.87), (4.10±1.62) and (1.30±0.48) μSv/h, respectively ( χ2=73.71, P<0.05). The dose rates on the left and right sides were (0.378±0.156) and (0.384±0.153) μSv/h at 30 cm, (0.170±0.089) and (0.17±0.086) μSv/h at 50 cm, (0.039 ±0.014) and (0.043±0.017) μSv/h at 100 cm, respectively ( χ2=76.19, 76.33, P<0.05). There was a linear relationship between the dose rate at the vertical particle implantation site and the total activity in the implanted particles, and between the dose rate and the implantation depth under the standard activity. The relationship between the warning time and the dose rate to adults in the same bed, co-workers, minors in the same bed and pregnant women were as follows: t ( d)=-106.616+ 83.779ln D( t), t ( d)=26.556+ 85.933ln D ( t), t( d)=3.088+ 85.017ln D( t). Conclusions:After 125I seed implantation, the radiation dose in the ambient environment is low, ensuring the radiation safety; and the measured dose rate decreases with the decrease in the total activity in the implanted particle and the increase in the implantation depth; at the same time, the warning time for different groups is calculated according to the measured dose rate or the total activity in the implanted particle and the depth of the implanted particle, so as to carry out individualized protection.