Objective:To investigate the influence of contrast-enhanced computed tomography(CECT)on dose calculation in magnetic resonance imaging(MRI)-guided online adaptive radiotherapy(oART)based on the electron density(ED)assignment method for rectal cancer.Methods:A retrospective analysis was conducted on the medical data of 15 patients with locally advanced rectal cancer at middle-low segments,who admitted to the Chinese PLA General Hospital between December 2023 and April 2025.All patients underwent both plain computed tomography(PCT)and CECT scans during location.The average HU and ED value of all organs that were extracted from PCT and CECT images in the treatment plan system were obtained,and the influences of contrast agent of intake on image characteristics of the structure of each organ(small intestine,femoral head,bladder)were analyzed.PCT was used as referred image to design reference plan(Pref).The synthetic CT(sCT)was simulated and generated on the basis of PCT and CECT,respectively.The beam flow field that was same with Pref was used to recalculate dose on sCT,and then,the online plan(PPCT)based on PCT,and the online plan(PCECT)based on CECT were obtained,respectively,which can simulate the online dose calculation of MRI-guided online adaptive radiotherapy(oART).The Pref was used as reference to compare dosimetric parameters for target region and organ at risk(OAR)through dose volume histogram(DVH)and planed evaluation indicators.Additionally,three dimension(3D)slicer software was used to perform γ analysis for the results of dose distribution,and explore the differences among PPCT,PCECT and Pref on dose distribution.Results:In terms of image characteristics,the HU values of soft-tissue organs(intestine,bladder,spinal cord,soft tissue)and planning target volume(PTV)in CECT were higher than those in PCT,and the differences of them were statistically significant(Zintestines=-2.188,Zbladder=-3.196,tspinal cord=-3.767,tsoft tissue=-10.083,tPTV=-4.693,P<0.05),while its influence was less on bone tissue.The statistical results of ED were consistent with those of HU.Regarding to dosimetric parameters,there was no statistically significant difference in target coverage rate between PPCT and Pref(P>0.05),and the D50%of the PPCT[(2724.25±19.91)cGy]was higher than that of the Pref[(2718.99±21.13)cGy],and the difference was statistically significant(t=-3.679,P=0.002).However,the target coverage rate of PCECT was 94.65(94.04,95.27)%,and the difference of that between PCECT and Pref was statistically significant(Z=-2.158,P=0.031).For OAR,the differences of Dmax value of the small intestine,and the V20 of the left femoral head between PPCT and Pref were significant(Z=-2.556,-2.529,P<0.05).The differences of the Dmax of small intestine,and the D50%of bladder between PCECT and Pref were significant(t=-4.821,2.171,P<0.05).The comparative γ passed rates of PPCT,PCECT and Pref under the standards of 3 mm/3%and 2 mm/2%were all above 95%,and the differences were not significant(P>0.05).Conclusions:The influence of CECT on dose calculation in MRI-guided oART based on ED assignment method for rectal cancer is relatively small,which can be directly used in the design of reference plan,but the maximum dose of radiation-sensitive organs such as the small intestine should be paid attention.

Objective:To investigate the influence of contrast-enhanced computed tomography(CECT)on dose calculation in magnetic resonance imaging(MRI)-guided online adaptive radiotherapy(oART)based on the electron density(ED)assignment method for rectal cancer.Methods:A retrospective analysis was conducted on the medical data of 15 patients with locally advanced rectal cancer at middle-low segments,who admitted to the Chinese PLA General Hospital between December 2023 and April 2025.All patients underwent both plain computed tomography(PCT)and CECT scans during location.The average HU and ED value of all organs that were extracted from PCT and CECT images in the treatment plan system were obtained,and the influences of contrast agent of intake on image characteristics of the structure of each organ(small intestine,femoral head,bladder)were analyzed.PCT was used as referred image to design reference plan(Pref).The synthetic CT(sCT)was simulated and generated on the basis of PCT and CECT,respectively.The beam flow field that was same with Pref was used to recalculate dose on sCT,and then,the online plan(PPCT)based on PCT,and the online plan(PCECT)based on CECT were obtained,respectively,which can simulate the online dose calculation of MRI-guided online adaptive radiotherapy(oART).The Pref was used as reference to compare dosimetric parameters for target region and organ at risk(OAR)through dose volume histogram(DVH)and planed evaluation indicators.Additionally,three dimension(3D)slicer software was used to perform γ analysis for the results of dose distribution,and explore the differences among PPCT,PCECT and Pref on dose distribution.Results:In terms of image characteristics,the HU values of soft-tissue organs(intestine,bladder,spinal cord,soft tissue)and planning target volume(PTV)in CECT were higher than those in PCT,and the differences of them were statistically significant(Zintestines=-2.188,Zbladder=-3.196,tspinal cord=-3.767,tsoft tissue=-10.083,tPTV=-4.693,P<0.05),while its influence was less on bone tissue.The statistical results of ED were consistent with those of HU.Regarding to dosimetric parameters,there was no statistically significant difference in target coverage rate between PPCT and Pref(P>0.05),and the D50%of the PPCT[(2724.25±19.91)cGy]was higher than that of the Pref[(2718.99±21.13)cGy],and the difference was statistically significant(t=-3.679,P=0.002).However,the target coverage rate of PCECT was 94.65(94.04,95.27)%,and the difference of that between PCECT and Pref was statistically significant(Z=-2.158,P=0.031).For OAR,the differences of Dmax value of the small intestine,and the V20 of the left femoral head between PPCT and Pref were significant(Z=-2.556,-2.529,P<0.05).The differences of the Dmax of small intestine,and the D50%of bladder between PCECT and Pref were significant(t=-4.821,2.171,P<0.05).The comparative γ passed rates of PPCT,PCECT and Pref under the standards of 3 mm/3%and 2 mm/2%were all above 95%,and the differences were not significant(P>0.05).Conclusions:The influence of CECT on dose calculation in MRI-guided oART based on ED assignment method for rectal cancer is relatively small,which can be directly used in the design of reference plan,but the maximum dose of radiation-sensitive organs such as the small intestine should be paid attention.

Background::The correlation between metals and hypertension, such as sodium, zinc, potassium, and magnesium, has been confirmed, while the relationship between aluminum and hypertension is not very clear. This study aimed to evaluate the correlation between plasma aluminum and hypertension in electrolytic aluminum workers by the Bayesian networks (BN).Methods::In 2019, 476 male workers in an aluminum factory were investigated. The plasma aluminum concentration of workers was measured by inductively coupled plasma mass spectrometry. The influencing factors on the prevalence of hypertension were analyzed by the BN.Results::The prevalence of hypertension was 23.9% in 476 male workers. The risk of hypertension from plasma aluminum in the Q2, Q3, and Q4 groups was 5.20 (1.90-14.25), 6.92 (2.51-19.08), and 7.33 (2.69-20.01), respectively, compared with that in the Q1 group. The risk of hypertension from the duration of exposure to aluminum of >10 years was 2.23 (1.09-4.57), compared without aluminum exposure. Area under the curve was 0.80 of plasma aluminum and the duration of exposure to aluminum was based on covariates, indicating that aluminum exposure had important predictive value in the prevalence of hypertension in the occupational population. The results of the study using the BN model showed that if the plasma aluminum of all participants was higher than Q4 (≥47.86 μg/L) and the participants were drinking, smoking, diabetes, central obesity, dyslipidemia, and aged >50 years, the proportion of hypertension was 71.2%.Conclusions::The prevalence of hypertension increased significantly with the increase of plasma aluminum level.

Objective:Based on multi-parametric prostate magnetic resonance imaging (mpMRI) and related clinical indicators, a nomogram model for patients with PI-RADS ≥3 and PSA 4-20ng/ml was developed and validated, and the predictive value of the model in diagnosing clinically significant prostate cancer was evaluated.Methods:The clinical and pathological data of 865 patients who underwent ultrasound-guided transperineal prostate biopsy for the first time at the Department of Urology, Second Hospital of Tianjin Medical University from January 2020 to August 2023, with PI-RADS scores ≥3 and PSA levels between 4-20 ng/ml were retrospectively analyzed. These 865 patients were included in Cohort A, and from them, 437 patients with PHI were selected in Cohort B. In Cohort A, the median age was 68(64, 73); the median f/tPSA was 14.36 (10.63, 19.74); the median PSAD was 0.17(0.11, 0.25); 375 cases (43.35%) with PV≤50 ml and 490 cases (56.65%) with PV>50 ml; PSA fluctuation <-50% 84 cases (9.71%), -50%--20% in 206 cases (23.82%), and >-20% in 575 cases (66.47%); PI-RADS v2.1 3 scores 546 cases (63.12%), 4 in 230 cases (23.59%), and 5 in 89 cases (10.29%); localization of suspicious lesions on mpMRI in the peripheral zone in 619 cases (71.56%), transitional zone in 181 cases (20.92%), others in 42 cases (4.86%), and both peripheral and transitional zones in 23 cases (2.66%). In Cohort B, the median PSAD was 0.17 (0.12, 0.25); the median D-dimer was 310.00 (230.00, 411.48); the median PHI was 49.75 (35.90, 73.27); with 198 cases (45.31%) with PV≤50 ml and 239 cases (54.69%) with PV>50 ml; PSA fluctuation<-50% was in 40 cases (9.15%), -50%--20% in 107 cases (24.49%), and>-20% in 290 cases (66.39%); PI-RADS v2.1 scores 3 was in 289 cases (66.13%), 4 in 103 cases (23.57%), and 5 in 45 cases (10.30%).Patients in cohorts A and B were randomly assigned to the training set and validation set using R language with " 123" as the random number seed, at a ratio of 7∶3.There was no statistically significant difference between the clinical data of the training and validation sets for both groups ( P>0.05).Univariate and multivariate logistic regression analyses were used to identify independent risk factors for CsPCa, and a nomogram model was constructed using R. The diagnostic performance of the prediction model was evaluated using receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis(DCA).External validation of the model was conducted in the validation set. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and missed diagnosis rate analyses were performed on nomogram models A and B, as well as PSAD and PHI, under different thresholds. Results:Cohort A training set has 608 cases, and the validation set has 257 cases.The results of multivariate backward regression analysis in the training set show that age( OR=1.06, P=0.001), f/tPSA( OR=0.96, P=0.008), prostate volume (PV)>50ml( OR=0.36, P<0.01), prostate-specific antigen density(PSAD)( OR=145.19, P<0.01), PSA fluctuation(-50%--20%: OR=1.97, P=0.234; >-20%: OR=6.81, P<0.01), PI-RADS v2.1 score(4: OR=10.65, P<0.01; 5: OR=21.20, P<0.01), and localization of suspicious lesions on mpMRI(TZ: OR=0.57, P=0.074; Others: OR=0.26, P=0.022) were all risk factors for CsPCa. Nomogram A was developed based on these risk factors and had an area under the ROC curve (AUC) of 0.905 (95% CI 0.881-0.928) for the training set and 0.893 (95% CI 0.854-0.931) for the validation set. Cohort B training set developed based on age( OR=1.05, P=0.053), PV>50ml( OR=0.18, P<0.01), PSAD( OR=54.14, P=0.021), PSA fluctuation(-50%--20%: OR=4.78, P=0.100; >-20%: OR=20.37, P=0.001), PHI( OR=1.02, P=0.002), D-Dimer( OR=1.00, P=0.031), and PI-RADS scores(4: OR=11.35, P<0.01; 5: OR=57.61, P<0.01) as risk factors for CsPCa. Nomogram B had an AUC of 0.933(95% CI 0.906-0.959) for the training set and 0.908 (95% CI 0.859-0.958) for the validation set.The two nomogram models mentioned above both have excellent discrimination, and the calibration curves also indicated that the calibration of the two models were good.Moreover, both nomogram A and nomogram B demonstrate good clinical net benefits in the DCA curves of the training and validation sets, especially when applying nomogram B to predict CsPCa, with an accuracy rate of up to 85.82%. Conclusions:The two nomogram models developed in study, based on mpMRI and related clinical indicators, both have excellent predictive value for the diagnosis of clinically significant prostate cancer prior to prostate biopsy in patients with PI-RADS≥3 and PSA 4-20ng/ml.

Background::The correlation between metals and hypertension, such as sodium, zinc, potassium, and magnesium, has been confirmed, while the relationship between aluminum and hypertension is not very clear. This study aimed to evaluate the correlation between plasma aluminum and hypertension in electrolytic aluminum workers by the Bayesian networks (BN).Methods::In 2019, 476 male workers in an aluminum factory were investigated. The plasma aluminum concentration of workers was measured by inductively coupled plasma mass spectrometry. The influencing factors on the prevalence of hypertension were analyzed by the BN.Results::The prevalence of hypertension was 23.9% in 476 male workers. The risk of hypertension from plasma aluminum in the Q2, Q3, and Q4 groups was 5.20 (1.90-14.25), 6.92 (2.51-19.08), and 7.33 (2.69-20.01), respectively, compared with that in the Q1 group. The risk of hypertension from the duration of exposure to aluminum of >10 years was 2.23 (1.09-4.57), compared without aluminum exposure. Area under the curve was 0.80 of plasma aluminum and the duration of exposure to aluminum was based on covariates, indicating that aluminum exposure had important predictive value in the prevalence of hypertension in the occupational population. The results of the study using the BN model showed that if the plasma aluminum of all participants was higher than Q4 (≥47.86 μg/L) and the participants were drinking, smoking, diabetes, central obesity, dyslipidemia, and aged >50 years, the proportion of hypertension was 71.2%.Conclusions::The prevalence of hypertension increased significantly with the increase of plasma aluminum level.

OBJECTIVE: To observe the effect of maltolate aluminum on synaptic plasticity in the hippocampus of rats and to explore the regulatory effect and mechanism of metabotropic glutamate receptor 1(mGluR1). METHODS: Specific pathogen free healthy adult male SD rats were randomly divided into control group, aluminum group, aluminum agonist group and aluminum antagonist group, 8 rats in each group. The rats in the control group received no treatment; the rats in aluminum group were injected with 5 μL 10 mmol/L maltolate aluminum solution into the lateral ventricle; the rats in aluminum agonists and aluminum antagonist group were injected with 3 μL 10 mmol/L maltolate aluminum solution plus 2 μL 0.1 μmol/L mGluR1 agonist or 2 μL 0.2 μmol/L mGluR1 antagonists into the lateral ventricle, respectively.Maltolate aluminum solution was injected every 2 days and continued for 10 days. After maltolate aluminum exposure, the amplitudes of long-term potentiation(LTP) in hippocampal CA1 region of rats were measured, and the relative expression levels of mRNA and protein of mGluR1, N-methyl-D-aspartate receptor(NMDAR1) and protein kinase C(PKC) in hippocampus tissue of rats were detected by real-time fluorescence quantitative polymerase chain reaction and Western blotting. RESULTS: The amplitude of LTP in hippocampal CA1 region in aluminum group and aluminum agonist group was lower than that in the control group and the aluminum antagonist group(P<0.05). Compared with the control group, the relative expression of mGluR1 mRNA and protein in the aluminum group increased, the relative expression of PKC and NMDAR1 mRNA and protein in the aluminum group decreased(P<0.05). Compared with the aluminum group, the relative expression of mGluR1 mRNA and protein in the aluminum agonist group increased, while the NMDAR1 mRNA decreased(P<0.05); the relative expression of mGluR1 mRNA and protein in the aluminum antagonist group decreased, while the NMDAR1 mRNA and protein increased(P<0.05). Compared with the aluminum agonist group, the relative expression of mGluR1 mRNA and protein decreased, while the NMDAR1 mRNA and protein increased in the aluminum antagonist group(P<0.05). The relative expression level of PKC mRNA and protein in aluminum agonist group and aluminum antagonist group was not statistically significant(P>0.05), and there was no statistical significance in these two groups compared with control group and aluminum group(P>0.05). CONCLUSION: Maltolate aluminum exposure can inhibit synaptic plasticity by inhibiting LTP in hippocampus of rats, and the mechanism may be related to the regulation of NMDAR1 expression by mGluR1.

OBJECTIVE: To study the effect of sub-chronic aluminum exposure on synaptic plasticity in the hippocampus of rats and to explore the mechanism of phosphatidylinositol 3 kinase(PI3 K)/protein kinase B(AKT)/rapamycin target protein(mTOR) signaling pathway. METHODS: Specific pathogen free adult healthy male SD rats were randomly divided into control group and low-, medium-and high-dose groups based on body weight, with 10 rats in each group. Rats were treated with maltol aluminum solution at the concentrations of 0, 10, 20 and 40 μmol/kg body weight by intraperitoneal injection, 5 days per week for 3 months. After the exposure, rats were weighed. Morris water maze was used to test the learning and memory ability, and the two-electrode binding technique was used to record the long-term potentiation(LTP) amplitude in the hippocampus CA1 area of rats. The protein expression of PI3 K, AKT and mTOR in rat hippocampus tissues was detected by Western blot. RESULTS: After the exposure, the body weights of rats in the medium-and high-dose groups were lower than that of the control group(P<0.05). The results of the positioning navigation experiment showed that the escape latencies of the rats in the medium-and high-dose groups were shorter than that in the control group during the 2 nd to 4 th days of the experiment(P<0.05). The results of space exploration experiments showed that there was no statistical difference on the target quadrant retention time and the number of crossing the platform among the 4 groups(P>0.05). At 1, 30, and 60 min after high-frequency stimulation, the LTP amplitudes in the hippocampus CA1 area of the aluminum-treated groups were lower than that of the control group at the same time point(P<0.05), and the LTP amplitudes of hippocampus CA1 area of rats decreased with the increase of maltol aluminum exposure dose(P<0.01). The relative expression of PI3 K, AKT and mTOR protein in the hippocampus tissues of the aluminum-treated groups was lower than that of the control group(P<0.05), and the relative expression of the above three proteins decreased with the increase of the maltol aluminum exposure dose(P <0.01). CONCLUSION: Sub-chronic aluminum exposure could lead to dose-dependent inhibition of hippocampus synaptic plasticity in rats, thereby impairing the spatial learning ability of rats. This process may be related to inhibition of PI3 K/AKT/mTOR signaling pathway by aluminum.

OBJECTIVE: To investigate the relationship of polycyclic aromatic hydrocarbons( PAH) metabolites,DNA oxidative damage and ring finger protein 2( RING2) expression in coke oven workers. METHODS: A judgment sampling method was used to select 497 coke oven workers in a steel plant as exposure group and 175 water treatment workers in the same plant as control group. The levels of urinary 1-hydroxypyrene, 2-hydroxynathalene, 2-hydroxyfluorene,9-hydroxyphenanthrene and 8-hydroxy deoxyguanosine(8-OHd G) were detected by high performance liquid chromatography.The RING2 expression in whole blood was measured by reverse transcription-polymerase chain reaction. RESULTS: The relative expression of urinary 1-hydroxypyrene,2-hydroxynathalene,2-hydroxyfluorene,9-hydroxyphenanthrene and RING2 in exposure group were higher than that in control group( P < 0. 01). The logistic regression analysis indicated that the higher the level of 1-hydroxypyrene,the higher the risk of high-RING2 expression( P < 0. 05) after adjusting for factors such as sex,age,smoking status,alcohol drinking,2-hydroxynathalene,2-hydroxyfluorene and 9-hydroxyphenanthrene.In 1-hydroxypyrene middle and high level groups,the 8-OHd G concentration of high-RING2 expression workers was significantly higher than those of low-RING2 expression workers( P < 0. 05). CONCLUSION: With the increase of urinary1-hydroxypyrene,the risk of high-RING2 expression was elevated,the degree of DNA oxidative damage was gradually increased.

OBJECTIVETo explore the role of P53 phosphorylation in neuron apoptosis of rats by chronic aluminum exposure.

METHODSA total of male 40 SD rats were divided randomly into 4 groups (n = 10/dose), the exposed groups were fed with normal diet with different concentration of AlCl3 · 6H2O for 6 months respectively. The dosage of low, middle and high groups were 10.73, 107.33, 1073.33 mg/kg in sequence. The control group received normal diet. The neuron apoptosis was measured by method of Tunel. The expressions of P53 and pP53-ser15 protein in the cortex were detected by Western-blot.

RESULTSTunel staining showed that the low, middle and high group rats had increased apoptosis rate than control group (P < 0.01). Western-blot test demonstrated that the expression of P53 protein in the cortex of high group rats were significantly higher than the control and low groups (P < 0.05). The expression of pP53-ser15 protein in the cortex of middle and high group rats were also higher than the control and low groups (P < 0.05).

CONCLUSIONChronic aluminum exposure can lead to over expression of P53 and pP53-ser15 protein in cerebral cortex, which maybe one of the most important mechanisms of neuron apoptosis induced by AlCl3.

Aluminum ; toxicity ; Aluminum Compounds ; toxicity ; Animals ; Apoptosis ; Cerebral Cortex ; metabolism ; Chlorides ; toxicity ; Male ; Neurons ; cytology ; drug effects ; Phosphorylation ; Rats ; Rats, Sprague-Dawley ; Tumor Suppressor Protein p53 ; metabolism

Chinese peacekeeping medical team established a Level II Hospital on Liberia in 2004. Peacekeeping medical teams abide by varieties rules on medical service support and establish management and maintenance system of medical instrument. More than 95% medical equipment is still kept in good condition after four years and the routine rate of self-maintenance of small medical equipments can be reached 95%. All the medical equipment have passed the half-yearly verification of ORI by UN, the experience have great value for future similar missions.