Objective To explore the clinical factors influencing complete response in patients with locally advanced rectal cancer (LARC) after neoadjuvant chemoradiotherapy (nCRT). Methods Clinical data of LARC patients treated in the Department of Radiation Oncology at Beijing Shijitan Hospital between January 2013 and December 2024 were retrospectively collected. All patients received nCRT, after which surgery or a watch-and-wait approach was adopted based on treatment response. Univariable and multivariable logistic regression analyses were performed to identify prognostic factors influencing complete response. A clinical prediction model was constructed based on the multivariable analysis results, and its predictive performance was evaluated using the receiver operating characteristic curve. Results A total of 113 eligible patients were included. After nCRT, 19 patients (16.8%) achieved complete response, including 3 with clinical complete response and 16 with pathological complete response. Univariable analysis indicated that pretreatment clinical N stage, extramural venous invasion, carcinoembryonic antigen level, and neoadjuvant treatment regimen were associated with complete response after nCRT (P<0.05). Multivariable logistic regression analysis identified pretreatment extramural venous invasion, carcinoembryonic antigen level, and neoadjuvant treatment regimen as independent influencing factors for complete response (P<0.05). A prediction model incorporating these independent factors yielded an area under the receiver operating characteristic curve of 0.813 (95% confidence interval: 0.713-0.913), with a sensitivity of 89.5% and a specificity of 60.6%, demonstrating good predictive performance. Conclusion Pretreatment extramural venous invasion, carcinoembryonic antigen level, and neoadjuvant treatment regimen are independent factors influencing complete response after nCRT in LARC patients. The prediction model combining these factors may assist in evaluating treatment efficacy following nCRT in LARC patients.

Objective:To analyze the survival and prognostic factors of male patients with breast cancer after mastectomy.Methods:Male patients with invasive breast ductal cancer who underwent mastectomy from January 1, 2000 to December 31, 2018 were selected from the Surveillance, Epidemiology, and End Results (SEER) database. Survival analysis was performed by Kaplan-Meier method, and compared by log-rank test. Prognostic factors were identified by Cox proportional hazards regression analysis.Results:A total of 1231 cases were included, with an onset age of (67 ± 12) years. The proportion of stage I-II was 81.1%. The 10-year cancer-specific survival (CSS) rates for stage IA, IIA, IIB, IIIA, IIIB, and IIIC patients were 85.4%, 84.9%, 69.0%, 68.1%, 51.9%, and 48.3%, respectively (all P<0.001). For stage IA-IIB patients, the 10-year CSS rate was 79.2% in the postoperative radiotherapy group, compared to 83.0% in the non-radiotherapy group ( P=0.019). For stage IIIA-IIIC patients, the 10-year CSS rate was 61.7% in the postoperative radiotherapy group, compared to 52.9% in the non-radiotherapy group ( P=0.021). For stage IA-IIB patients, the 10-year CSS rate was 83.8% in the postoperative chemotherapy group, compared to 79.8% in the non-chemotherapy group ( P=0.342). For stage IIIA-IIIC patients, the 10-year CSS rate was 59.7% in the postoperative chemotherapy group, compared to 54.1% in the non-chemotherapy group ( P=0.052). Multivariate analysis showed that younger age, married and grade I-II differentiation were favorable prognostic factors. The earlier the tumor staging, the better the prognosis. Conclusions:Postoperative radiotherapy can improve the CSS of stage III male patients with breast cancer. Younger age, married, grade I-II differentiation are favorable prognostic factors. The earlier the tumor staging, the better the prognosis.

Objective To establish an allogeneic rat model of endometriosis and to evaluate the effects of gonadotropin-releasing hormone (GnRH) agonist GenSci006 on experimental rat endometriosis. Methods Endometrium from SPF grade donor female SD rats were transplanted onto the abdominal wall of recipient female rats to construct an allogeneic endometriosis model. The rats undergoing sham surgery were divided into the sham group. Three weeks later, the length, width and height of the ectopic endometrium were measured, and the volume of the endometrium (V₁) was calculated before drug administration. The modeling rats were randomly divided into four groups: model group, triptorelin group (0.25 mg/kg), GenSci006-1 group (0.125 mg/kg) and GenSci006-2 group (0.25 mg/kg). Each group had 16 rats and received a single dose of the corresponding drug. The sham group and model group were administered an equal volume of solvent. Three weeks after administration, ectopic endometrium was measured to calculate the volume V₂ and inhibition rate. The effect of GenSci006 on rat uterus and ovarian tissues was assessed by comparing organ coefficients and changes in pathological sections. Enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of serum estradiol (E₂), progesterone (P₄), follicle stimulating hormone (FSH), and luteinizing hormone (LH). Real-time fluorescent quantitative PCR was used to detect the expression of GnRH receptor (GnRHR) mRNA in the hypothalamus and pituitary. Western blot was used to detect the expression of estradiol receptor alpha (ERα), beta (ERβ) and progesterone receptor (PR) in ectopic endometrium. Results Three weeks after administration, compared with the model group, the body weight of rats in the triptorelin and GenSci006-2 groups significantly increased (P < 0.05), while the volume of ectopic endometrium significantly decreased (P < 0.05). Compared with the sham group, the model group showed no significant changes in uterine and ovarian organ coefficients or endometrial thickness (P > 0.05). Compared with the model group, the uterine organ coefficients and endometrial thickness were significantly reduced in the triptorelin and GenSci006-2 groups (P < 0.05). Compared with the sham group, the serum levels of E₂, P₄, FSH and LH in the model group showed no significant changes (P > 0.05). Compared with the model group, the ovarian organ coefficient and serum P₄ levels of rats in the Triptorelin, GenSci006-1, and GenSci006-2 groups were significantly reduced (P < 0.05), while the serum LH levels of rats in the GenSci006-1 group were significantly increased (P < 0.05). However, there were no significant changes in serum E₂ and FSH levels in each group (P > 0.05). Compared with the model group, the expression levels of GnRHR mRNA in the pituitary tissue of rats in the triptorelin and GenSci006-2 groups were significantly downregulated (P < 0.05), with no significantly changes in the hypothalamus (P > 0.05). There were no significant changes in the expression level of GnRHR mRNA in the hypothalamus or the protein levels of ERα, ERβ and PR in the ectopic endometrial tissue in any group (P > 0.05). Conclusion The allogeneic endometriosis rat model is a suitable animal model for screening and evaluating drugs for treating endometriosis. The volume of ectopic endometrium, inhibition rate, uterine and ovarian organ coefficients, and serum E₂ levels may serve as indicators for detecting drug efficacy.

Based on the education and work experience in the radiotherapy and radiation protection industries in China and the United States, combined with comprehensive surveys into relevant websites and public materials of American health physics, this review introduces the education system of health physics and the certification system for health physicists in the United States. Furthermore, this paper provides a summary of the current status of academic education in radiation protection, the practical operations of radiation protection in medical institutions, and the staffing related to radiation safety in China. Accordingly, this study offers opinions and suggestions for further improving the disciplinary system of radiation protection in China.

Objective:To explore the effects of consecutively repeated application of emergency contraception pills (ECPs) containing levonorgestrel (LNG) on the female fertility and the health outcomes of F1 generation rats.Methods:Female SPF rats were intragastric administered with LNG-ECPs consecutively for 3 (P-3), 6 (P-6) and 12 (P-12) estrous cycles (three times in each estrous cycle), respectively. Under each administration schedule, rats were randomly divided into 2 groups according to body weight stratification using random numbers generated in Excel, i.e. LNG-ECPs group and solvent control group, administered with 0.12 mg/kg LNG-ECPs and corresponding volumes of 0.5% CMC-Na, respectively. Four hours after the last dosing, half of the animals (12-18) in each group were allotted randomly for dissection (6-9) and mating (6-9), respectively. The remaining half (12-18) were recovered for 3 estrous cycles, and then were randomly allocated for dissection (6-9) and mating (6-9). Organ coefficients were calculated. Serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol, progesterone, testosterone, anti-Müllerian hormone (AMH) and free thyroid hormone 3 (fT3) were examined by enzyme linked immunosorbent assay (ELISA). Ovarian tissues were sectioned and stained with hematoxylin and eosin (HE) for follicle counting. In addition, the pregnancy rate and litter size of the female rats were recorded, and the growth indexes and behavioral parameters of the cubs were measured. Moreover, RNA sequencing (RNA-seq) of the ovarian tissues was performed to establish the differential expression gene profile of ovarian injury induced by LNG-ECPs. Then gene ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment were analyzed.Results:1) After consecutive administration for 3 and 6 estrous cycles, LNG-ECPs showed no significant impact on the serum hormone levels and female fertility (all P>0.05), and the growth indexes and behavioral parameters of the F1 generation (all P>0.05). 2) After consecutive administration for 12 estrous cycles, the serum levels of FSH [(0.21±0.17) U/L], LH [(0.27±0.08) U/L] and progesterone [(0.68±0.23) μg/L] in LNG-ECPs group decreased significantly compared with those in solvent control group [(1.00±0.82) U/L, P=0.043; (1.00±0.50) U/L, P=0.006; (1.00±0.20) μg/L, P=0.027], while the level of estradiol [(2.24±1.03) μg/L] and testosterone [(1.25±0.25) μg/L] increased noticeably compared with those in solvent control group [(1.00±0.35) μg/L, P=0.019; (1.00±0.07) μg/L, P=0.044]. The number of primordial follicles (4.88±2.36) lost distinctly, while the number of atretic follicles (24.38±5.01) increased markedly in LNG-ECPs group compared with those in solvent control group (16.13±9.36, P=0.005; 19.13±2.30, P=0.018). In addition, the weight-loaded swimming (WLS) time of the F1 generation rats from the LNG-ECPs group [(157.13±32.29) s] reduced obviously compared with those from the solvent control group [(198.06±40.01) s, P=0.003]. Moreover, after recovering for 3 estrous cycles, LNG-ECPs significantly increased the levels of FSH [(2.48±1.18) U/L], LH [(1.60±0.41) U/L], testosterone [(1.37±0.23) μg/L] and the ratio of FSH/LH (1.61±0.41) compared with those in solvent control group [(1.00±0.67) U/L, P=0.024; (1.00±0.27) U/L, P=0.014; (1.00±0.18) μg/L, P=0.011; 1.00±0.49, P=0.042], respectively. Additionally, the serum levels of estradiol [(0.49±0.15) μg/L] and AMH [(0.79±0.15) μg/L] were significantly lower than those in solvent control group [(1.00±0.37) μg/L, P=0.011; (1.00±0.10) μg/L, P=0.016]. In addition, the number of primordial follicles in rats of LNG-ECPs group (6.25±5.06) were obviously less than that in solvent control group (12.00±5.56, P=0.048). Furthermore, the total distance in open field [(89.85±36.98) m] and the swimming time in WLS [(112.00±29.52) s] in rats treated with LNG-ECPs both decreased distinctly compared with those in solvent control group [(147.55±23.13) m, P<0.001; (137.69±25.85) s, P=0.014]. 3) According to transcriptomic analysis, Cd5, Cxcr1, Lexm, Fga, Mybphl and Gstm5 were the significant differential expressed genes (DEGs) in the ovarian tissues of rats. These DEGs were involved in pathways related to steroid hormone biosynthesis, including terpenoid backbone biosynthesis, ovarian steroidogenesis, cortisol synthesis and secretion. Additionally, these genes were involved in metabolic processes, such as carbon metabolism, butanoate metabolism, cysteine and methionine metabolism. And the genes were also involved in immunoregulatory processes including cytokine-cytokine receptor interaction, viral protein interaction with cytokine and cytokine receptors. Conclusion:Consecutively repeated administering LNG-ECPs to the female rats in a short-term period (<12 cycles) did not demonstrate significant adverse effects on female fertility and the growth and development and the behaviors of their F1 generation cubs. However, long-term repeated treatment with LNG-ECPs (12 cycles) caused ovarian injury on female rats and showed negative impacts on the health of the F1 generation cubs, and no significant improvement was observed after recovering for 3 estrous cycles.

Objective:To explore the effects of consecutively repeated application of emergency contraception pills (ECPs) containing levonorgestrel (LNG) on the female fertility and the health outcomes of F1 generation rats.Methods:Female SPF rats were intragastric administered with LNG-ECPs consecutively for 3 (P-3), 6 (P-6) and 12 (P-12) estrous cycles (three times in each estrous cycle), respectively. Under each administration schedule, rats were randomly divided into 2 groups according to body weight stratification using random numbers generated in Excel, i.e. LNG-ECPs group and solvent control group, administered with 0.12 mg/kg LNG-ECPs and corresponding volumes of 0.5% CMC-Na, respectively. Four hours after the last dosing, half of the animals (12-18) in each group were allotted randomly for dissection (6-9) and mating (6-9), respectively. The remaining half (12-18) were recovered for 3 estrous cycles, and then were randomly allocated for dissection (6-9) and mating (6-9). Organ coefficients were calculated. Serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol, progesterone, testosterone, anti-Müllerian hormone (AMH) and free thyroid hormone 3 (fT3) were examined by enzyme linked immunosorbent assay (ELISA). Ovarian tissues were sectioned and stained with hematoxylin and eosin (HE) for follicle counting. In addition, the pregnancy rate and litter size of the female rats were recorded, and the growth indexes and behavioral parameters of the cubs were measured. Moreover, RNA sequencing (RNA-seq) of the ovarian tissues was performed to establish the differential expression gene profile of ovarian injury induced by LNG-ECPs. Then gene ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment were analyzed.Results:1) After consecutive administration for 3 and 6 estrous cycles, LNG-ECPs showed no significant impact on the serum hormone levels and female fertility (all P>0.05), and the growth indexes and behavioral parameters of the F1 generation (all P>0.05). 2) After consecutive administration for 12 estrous cycles, the serum levels of FSH [(0.21±0.17) U/L], LH [(0.27±0.08) U/L] and progesterone [(0.68±0.23) μg/L] in LNG-ECPs group decreased significantly compared with those in solvent control group [(1.00±0.82) U/L, P=0.043; (1.00±0.50) U/L, P=0.006; (1.00±0.20) μg/L, P=0.027], while the level of estradiol [(2.24±1.03) μg/L] and testosterone [(1.25±0.25) μg/L] increased noticeably compared with those in solvent control group [(1.00±0.35) μg/L, P=0.019; (1.00±0.07) μg/L, P=0.044]. The number of primordial follicles (4.88±2.36) lost distinctly, while the number of atretic follicles (24.38±5.01) increased markedly in LNG-ECPs group compared with those in solvent control group (16.13±9.36, P=0.005; 19.13±2.30, P=0.018). In addition, the weight-loaded swimming (WLS) time of the F1 generation rats from the LNG-ECPs group [(157.13±32.29) s] reduced obviously compared with those from the solvent control group [(198.06±40.01) s, P=0.003]. Moreover, after recovering for 3 estrous cycles, LNG-ECPs significantly increased the levels of FSH [(2.48±1.18) U/L], LH [(1.60±0.41) U/L], testosterone [(1.37±0.23) μg/L] and the ratio of FSH/LH (1.61±0.41) compared with those in solvent control group [(1.00±0.67) U/L, P=0.024; (1.00±0.27) U/L, P=0.014; (1.00±0.18) μg/L, P=0.011; 1.00±0.49, P=0.042], respectively. Additionally, the serum levels of estradiol [(0.49±0.15) μg/L] and AMH [(0.79±0.15) μg/L] were significantly lower than those in solvent control group [(1.00±0.37) μg/L, P=0.011; (1.00±0.10) μg/L, P=0.016]. In addition, the number of primordial follicles in rats of LNG-ECPs group (6.25±5.06) were obviously less than that in solvent control group (12.00±5.56, P=0.048). Furthermore, the total distance in open field [(89.85±36.98) m] and the swimming time in WLS [(112.00±29.52) s] in rats treated with LNG-ECPs both decreased distinctly compared with those in solvent control group [(147.55±23.13) m, P<0.001; (137.69±25.85) s, P=0.014]. 3) According to transcriptomic analysis, Cd5, Cxcr1, Lexm, Fga, Mybphl and Gstm5 were the significant differential expressed genes (DEGs) in the ovarian tissues of rats. These DEGs were involved in pathways related to steroid hormone biosynthesis, including terpenoid backbone biosynthesis, ovarian steroidogenesis, cortisol synthesis and secretion. Additionally, these genes were involved in metabolic processes, such as carbon metabolism, butanoate metabolism, cysteine and methionine metabolism. And the genes were also involved in immunoregulatory processes including cytokine-cytokine receptor interaction, viral protein interaction with cytokine and cytokine receptors. Conclusion:Consecutively repeated administering LNG-ECPs to the female rats in a short-term period (<12 cycles) did not demonstrate significant adverse effects on female fertility and the growth and development and the behaviors of their F1 generation cubs. However, long-term repeated treatment with LNG-ECPs (12 cycles) caused ovarian injury on female rats and showed negative impacts on the health of the F1 generation cubs, and no significant improvement was observed after recovering for 3 estrous cycles.

Based on the education and work experience in the radiotherapy and radiation protection industries in China and the United States, combined with comprehensive surveys into relevant websites and public materials of American health physics, this review introduces the education system of health physics and the certification system for health physicists in the United States. Furthermore, this paper provides a summary of the current status of academic education in radiation protection, the practical operations of radiation protection in medical institutions, and the staffing related to radiation safety in China. Accordingly, this study offers opinions and suggestions for further improving the disciplinary system of radiation protection in China.

Objective:To investigate the differences between the mental clips placed intraoperatively and the tumor bed's target volume delineation of seroma based on CT scanning during radiotherapy for breast cancer patients who received breast-conserving surgery in the persuit of a better solution to determine the tumor bed position.Methods:The clinical data of 13 patients with early breast cancer who received postoperative radiotherapy after breast-conserving surgery at Beijing Shijingshan Hospital and Beijing Shijitan Hospital of Capital Medical University from December 2020 to January 2022 were retrospectively analyzed. They all had surgical clips implanted during the surgery. The following methods were used to delineate the target volume of tumor bed, including gross target volume delineation of tumor bed based on the mental clips (GTVtb-Clip), the tumor bed's gross target volume delineation of seroma based on CT scanning (GTVtb-Seroma), and the combination of both (GTVtb-C+S). The volume, diameter on three coordinate axis, neutral point displacement and conformability of these delineation methods were compared.Results:The volume of GTVtb-Clip, GTVtb-Seroma and GTVtb-C+S was (25±10) cm 3, (38±17) cm 3, (49±20) cm 3, and the differences were statistically significant (all P<0.05). The diameter on X axis was (4.7±1.2) cm, (5.3±1.4) cm, (5.7±1.6) cm, respectively in GTVtb-Clip, GTVtb-Seroma and GTVtb-C+S; the diameter on Y axis was (4.6±1.7) cm, (5.0±1.6) cm, (5.7±1.7) cm, respectively in GTVtb-Clip, GTVtb-Seroma and GTVtb-C+S; the diameter on Z axis was (4.4±1.5) cm, (5.2±1.4) cm, (5.6±1.4) cm in GTVtb-Clip, GTVtb-Seroma and GTVtb-C+S. The differences in the diameter of GTVtb-Clip and GTVtb-C+S on X,Y, Z axis were statistically significant (all P<0.05); the differences in the diameter of GTVtb-Seroma and GTVtb-C+S on X, Z axis were statistically significant (all P<0.05); the difference in the diameter of GTVtb-Clip and GTVtb-Seroma on X axis was statistically significant ( P<0.05) .Neutral point displacement was (5.8±1.6) cm, (5.5±1.9) cm, (6.0±1.7) cm, respectively of GTVtb-Clip, GTVtb-Seroma, GTVtb-C+S, and the difference was not statistically significant ( P>0.05). Conformability of GTVtb-Clip and GTVtb-Seroma, GTVtb-Clip and GTVtb-C+S, GTVtb-Seroma and GTVtb-C+S was 0.412±0.112, 0.525±0.095, 0.774±0.112,respectively, and the differences were statistically significant (all P<0.05). Conclusions:During radiotherapy after breast-conserving surgery for breast cancer, compared with the single method, the combination of GTVtb-Clip and GTVtb-Seroma can better cover the real tumor bed, thus reducing the omission of tumor bed and recurrence rate. CT position should better take place at 4 to 8 weeks for patients receiving radiotherapy after breast-conserving surgery, and target volume of tumor bed will be delineated based on the postoperative changes of both mental clips and seroma.

Objective:To establish and evaluate a rapid nucleic acid detection method for SARS-CoV-2 based on COYOTE ? Flash20 real-time fluorescent quantitative PCR instrument. Methods:A rapid reaction system was constructed by using specific primer and probe sets targeting ORF1ab and N gene of SARS-CoV-2, and the sensitivity and specificity of the system were verified. At the same time, 108 clinical samples of COVID-19 were used to evaluate the application of this method.Results:The detection method did not require nucleic acid extraction, and the manual operation time was only one minute. After the sample was sent to the system, the test could be completed in 30 minutes. The detection limit of this method was 4×10 2 copies/ml. It had no cross-reactivity with other human coronaviruses (including HCoV-229E, HCoV-NL63, HCoV-OC43, HCoV-HKU1, SARS-CoV and MERS-CoV) and other respiratory viruses. The evaluation of clinical sample application showed that the total coincidence rate with the conventional RT-qPCR which required nucleic acid extraction was 98.15%. Conclusions:Through the application evaluation of the rapid fluorescent quantitative PCR method of SARS-CoV-2, it was found that the method was simple, fast, specific and sensitive, and it was suitable for real-time and rapid detection needs in varieties of situations.

Objective To explore the mechanism of human umbilical cord mesenchymal stem cell (HUC-MSC) alleviating ischemia-reperfusion injury (IRI) of liver cells through mitochondrial transfer. Methods Normal human liver cell line L02 was divided into the blank control group, oxygen-glucose deprivation (OGD) group, experimental control group, and L02 and HUC-MSC co-culture group (L02+HUC-MSC group). L02+HUC-MSC group was further divided into 10:1 co-culture subgroup (group A), 4:1 co-culture subgroup (group B), 2:1 co-culture subgroup (group C), 1:1co-culture subgroup (group D) and 1:2 co-culture subgroup (group E) according to different co-culture ratio of L02 and HUC-MSC. The apoptosis rate and relative reactive oxygen species (ROS) level of L02 cells were detected by flow cytometry. The MitoTracker positive rate of L02 cells was detected by flow cytometry. The mitochondrial transfer from HUC-MSC to L02 cells was observed by laser confocal microscope. Results The apoptosis rate and relative ROS level of L02 cells in the OGD group were significantly higher than those in the blank control group (both P < 0.05). Compared with the OGD group, the apoptosis rates of L02 cells in group B, C, D and E were significantly decreased (all P < 0.05), and the relative ROS level of L02 cells in group E was significantly declined (P < 0.05). The MitoTracker positive rate of L02 cells did not significantly differ between group A and experimental control group (P>0.05), whereas the MitoTracker positive rates of L02 cells in group B, C, D and E were significantly higher than that in the experimental control group in a concentration-dependent manner (all P < 0.05). Under the laser confocal microscope, mitochondrial transfer fromHUC-MSC to L02 cells could be observed through tunneling nanotube (TNT). Conclusions HUC-MSC may alleviate cell apoptosis and reduce ROS level of liver cells after IRI via direct mitochondrial transfer between cells.