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OBJECTIVE@#To investigate the effects of SINC, a secreted protein of Chlamydia psittaci, on autophagy of host cells and the role of MAPK/ERK signaling pathway in mediating SINC-induced autophagy.@*METHODS@#RAW 264.7 cells treated with recombinant SINC were examined for changes in expression levels of LC3-II, Beclin-1, phosphorylated and total ERK1/2 using Western blotting. The expression level of LC3 in the treated cells was detected using immunofluorescence analysis, and the formation of autophagosomes and autolysosomes was observed with transmission electron microscopy (TEM). The effect of pretreatment with U0126 (a specific ERK inhibitor) on the expression levels of LC3-II and Beclin-1 in RAW 264.7 cells exposed to different concentrations of SINC was examined using Western blotting, and LC3 puncta in the cells was detected with immunofluorescence analysis.@*RESULTS@#The expression levels of LC3-II and Beclin-1 were the highest in RAW 264.7 cells treated with 2 μg/mL SINC for 12h. Immunofluorescence analysis showed exposure to SINC significantly increased the number of cells containing LC3 puncta, where the presence of autophagosomes and autolysosomes was detected. Exposure to 2 μg/mL SINC for 15 min resulted in the most significant increase of the ratios of p-ERK1/2/ERK1/2 in RAW 264.7 cells. Pretreatment of the cells with U0126 prior to SINC exposure significantly decreased the ratio of p-ERK1/2/ERK1/2, lowered the expression levels of LC3-II and Beclin-1, and decreased LC3 aggregation in the cells.@*CONCLUSIONS@#SINC exposure can induce autophagy in RAW 264.7 cells by activating the MAPK/ERK signaling pathway.
Subject(s)
MAP Kinase Signaling System , Chlamydophila psittaci , Beclin-1 , Signal Transduction , AutophagyABSTRACT
Drug-induced liver injury (DILI) risk prediction, diagnosis establishment, clinical management, and all other aspects are facing great challenges. Although the current understanding of its pathogenesis is still incomplete, research over the past 20 years has shown that genetic susceptibility may play an important role in the occurrence and development of DILI. In recent years, pharmacogenomics studies have further revealed the association between human leukocyte antigen (HLA) genes, some non-HLA genes, and hepatotoxicity from certain drugs. However, due to the lack of well-designed, prospective, large-sample cohort validation and low positive predictive values, there may still be some way to go before the current results can be truly translated into clinical practice for precise prediction and prevention of DILI risk.
Subject(s)
Humans , Genetic Predisposition to Disease , Prospective Studies , Risk Factors , Chemical and Drug Induced Liver Injury/genetics , Drug-Related Side Effects and Adverse Reactions , LiverABSTRACT
BACKGROUND@#Venous thromboembolism (VTE) as the most common cancer-associated complication has become the second death-causing reason among cancer patients. The management of VTE in patients with lung adenocarcinoma should focus on early and timely detection of risk factors. The aim of the study is to investigate the current situation of VTE in patients with lung adenocarcinoma treated with anti-tumor therapy and then explore the risk factors associated with the occurrence of VTE during anti-tumor therapy for early detection and screening of VTE.@*METHODS@#The present study included patients diagnosed as lung adenocarcinoma undergoing anti-tumor therapy in First Affiliated Hospital of Nanjing Medical University between December 2019 and May 2021. The risk factors were identified via univariate and multivariate Cox analysis. The incidence of independent risk factors were investigated through Kaplan-Meier curves combined with Log-rank test.@*RESULTS@#The results of univariate and multivariate Cox regression showed that history of VTE, targeted therapy and radiotherapy were risk factors for VTE in patients with lung adenocarcinoma treated with anti-tumor therapy (P<0.05). Furthermore, the results of Kaplan-Meier curves and Log-rank tests indicated the incidences of VTE in patients with history of VTE, targeted therapy and radiotherapy were higher (P<0.05).@*CONCLUSIONS@#History of VTE, radiotherapy and targeted therapy are found as independent risk factors for the occurrence of VTE, which should be identified and monitored for reduction of VTE incidence. .
Subject(s)
Humans , Venous Thromboembolism , Incidence , Lung Neoplasms , Adenocarcinoma of Lung , Risk FactorsABSTRACT
AIM: To compare the accuracy of different intraocular lens(IOL)calculation formulas in cataract patients with axial length longer than 28mm and a history of radial keratotomy(RK).METHODS: Retrospective study. The medical records of 19 cataract patients(29 eyes)after RK and with axial length longer than 28mm who underwent cataract surgery from January 2011 to July 2020 in Beijing Tongren Hospital were analyzed. The absolute error(AE)of the difference among three different formulas was calculated. AE refers to the absolute value between the actual spherical equivalent after cataract surgery and the spherical equivalent predicted by the IOL formula. The AE values of the three formulas and the percentages of eyes with AE≤0.5, 0.75, 1.0, and 2.0D were calculated and compared.RESULTS: The AE values of the three formulas were significantly different(χ2=8.759, P=0.013). The Barrett True-K formula had the smallest median AE, which was only 0.62(0.20, 1.15)D, followed by the Haigis formula 0.76(0.34, 1.26)D, and the Holladay 1(D-K)formula had the largest 1.01(0.49, 1.62)D. The percentages of affected eyes with AE ≤0.5, 0.75, 1.0, and 2.0D for the Barrett True-K formula were 48%, 59%, 69%, and 93%, which were equal to or higher than the other two formulas.CONCLUSION: The Barrett True-K formula is more recommended among the three formulas for cataract patients after RK and with axial length longer than 28 mm.
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Objective: To investigate the prevalence of work-related musculoskeletal disorders(WMSDs) among intensive care unit (ICU) nurses, assess its relationship with ergonomic load and overall exposure levels. Methods: A total of 272 ICU nurses from two tertiary hospitals in a city were selected as the research subjects using convenient sampling method. The Chinese Musculoskeletal Disorder Questionnaire was used to investigate the prevalence of WMSDs among the ICU nurses. The Quick Exposure Check (QEC) was used to assess the ergonomic load on the back, shoulder/arm, hand/wrist, and neck during different clinical nursing operations. Results: The annual prevalence of WMSDs was 75.7% among ICU nurses. The annual prevalence of WMSDs in different body parts, from high to low, was as follows： lower back, neck, shoulder/arm, back, knee, hip/leg, hand/wrist, ankle/foot, and elbow (54.8% vs 43.4% vs 40.8% vs 36.0% vs 21.3% vs 19.9% vs 18.8% vs 18.4% vs 8.1%, P<0.01). ICU nurses had the highest QEC scores on the back (dynamic), shoulder/arm, hand/wrist, and neck with assisting patient turning (all P<0.05) among the six clinical nursing items. During the operation of patient turning, patient lifting, patient bathing, and bed sheet changing for bedridden patients, the back (dynamic) and shoulder/arm were at a high load level, while the hand/wrist and neck were at a mild load level. When nurses were providing tracheostomy care and oral care for intubated patients, their back (static), shoulder/arm, hand/wrist, and neck were at a mild load level. The overall exposure rate for assisting patient turning, patient lifting, oral care for intubated patients, bed sheet changing for bedridden patients, patient bathing, and tracheostomy care were 77.8%, 66.5%, 63.6%, 60.2%, 58.5%, and 57.4%, respectively. The risk for assisting patient turning was classified as level four, while the risk for other clinical nursing items was level three. Conclusion: The prevalence of WMSDs in ICU nurses is high. Both ergonomic load level and total exposure rate of back, shoulder/arm, hand/wrist and neck were high during clinical nursing operations.
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@#AIM: To observe the epidemiological characteristics of myopia among primary school students in Xindu District of Chengdu before and after COVID-19 home isolation period(from Jan.-May 2020).<p>METHODS:Cross-sectional study. A total of 10 153 primary school students from grade 1-6(age 6-13, three classes per grade)were selected from four primary schools in Xindu District of Chengdu for three consecutive years(2018-2020), by using a random stratified cluster sampling method. All students' visual acuity and spherical equivalent refraction(SE)were measured, a further cycloplegia optometry was conducted for those whose visual acuity was less than 5.0. The SE was recorded and the prevalence of myopia was calculated. Chi-square test was used to compare the difference of prevalence of myopia between different years. One-way Anova was used to compare the difference of SE among different years.<p>RESULTS: There was statistical difference in prevalence of myopia between the three years(2018: 35.98%, 2019: 36.29%, 2020: 42.52%; χ<sup>2</sup>=39.374, <i>P</i><0.001). The prevalence of myopia among 6-9 years old students increased significantly in 2020(<i>P</i><0.01). They were 2.20 times(6 years old), 2.08 times(7 years old), 1.36 times(8 years old)and 1.24 times(9 years old)of the previous year. Students aged 6-9 years showed an obvious myopic shift in SE in 2020(<i>P</i><0.05). The increases were -0.34±0.76D(6 years old), -0.28±0.84D(7 years old), -0.29±1.41D(8 years old)and -0.18±1.35D(9 years old)than the previous year. The prevalence of myopia and SE remained stable among 10-13 years old students in 2018-2020(<i>P</i>>0.05).<p>CONCLUSION: After the COVID-19 home isolation period, there was a significant myopic shift among students aged 6-9 years old. We should pay more attention to the window period for myopia prevention and control of 6-9 years old.
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Objective:To explore the relationship among illness perception, patient activation and self-management in patients with lung cancer, and to investigate the mediating effect of patient activation between illness perception and self-management.Methods:A total of 270 inpatients with lung cancer were selected by convenience sampling method.They were investigated by self-made social demographic questionnaire, brief illness perception questionnaire(BIPQ), patient activation measure(PAM13)and cancer patient self-management scale.SPSS 26.0 software was used for data analysis.T-test, analysis of variance, Pearson correlation analysis and mediating effect test were used for statistical analysis.Results:A total of 255 questionnaires were collected effectively.The total score of illness perception, patient activation and self-management in patients with lung cancer were (41.91±7.94), (62.31±16.39)and (142.20±20.59) .The total score of illness perception of lung cancer patients was significantly negatively correlated with the total score of patient activation and patient self-management( r=-0.652, P<0.01; r=-0.762, P<0.01), and the total score of patient activation was significantly positively correlated with the total score of self-management in patients with lung cancer( r=0.746, P<0.01). Patient activation had a partial mediating effect between illness perception and self-management in patients with lung cancer, and the mediating effect accounted for 37.10% of the total effect. Conclusion:Patient activation plays a partial mediating role between illness perception and self-management in lung cancer patients, and it is an important protective factor for patients to actively participate in self-management of disease.On the basis of assessing the illness perception and patient activation of lung cancer patients, medical staff can timely correct the negative illness perception and help them establish and maintain a high positivity level to improve their self-management.
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OBJECTIVES@#To investigate the influencing factors for the quality of bowel preparation before colonoscopy in children and the association of the interval from the last administration of laxative to the start of colonoscopy (shortly referred to as waiting time) with the quality of bowel preparation.@*METHODS@#A retrospective analysis was performed for the children who were admitted to the Department of Gastroenterology, Children's Hospital of Nanjing Medical University, from January to November 2020, and received bowel preparation with polyethylene glycol electrolyte powder combined with diet control before colonoscopy. According to the score of Boston bowel preparation scale, they were divided into two groups: adequate bowel preparation group (n=337) and inadequate bowel preparation group (n=30). Related data were collected from the children in both groups, including general information, possible influencing factors for the quality of bowel preparation, adverse reactions associated with bowel preparation, duration of colonoscopy, and postoperative diagnosis. Univariate and multivariate analyses were used to explore the influencing factors for the quality of bowel preparation.@*RESULTS@#The univariate analysis showed that age, body weight, and waiting time were associated with inadequate bowel preparation (P<0.05). The multivariate analysis showed that older age (OR=2.155, 95%CI: 1.087-4.273, P=0.028) and longer waiting time (OR=1.559, 95% CI: 1.191-2.041, P=0.001) were independent risk factors for inadequate bowel preparation. The receiver operating characteristic (ROC) curve analysis showed that the cut-off value of waiting time was 5.5 hours in determining whether bowel preparation was adequate or not, with a sensitivity of 90.0%, a specificity of 50.7%, and an area under the ROC curve of 0.708. After grouping based on waiting time, it was found that the incidence rate of inadequate bowel preparation in the ≥5.5 hours group was significantly higher than that in the <5.5 hours group [14.0% (27/193) vs 1.7% (3/174), P<0.001].@*CONCLUSIONS@#For children who use polyethylene glycol electrolyte powder combined with diet control for bowel preparation, older age is an independent risk factor for inadequate bowel preparation before colonoscopy, which may be associated with an insufficient dose of polyethylene glycol in older children. Longer waiting time is also an independent risk factor for inadequate bowel preparation, and it is recommended that the waiting time should not exceed 5.5 hours.
Subject(s)
Child , Humans , Cathartics , Colonoscopy , Diet , Electrolytes , Polyethylene Glycols/adverse effects , Powders , Retrospective StudiesABSTRACT
OBJECTIVE@#To investigate the effects of melatonin on the growth and metastasis of MDA-MB-231 breast cancer cells and explore the mechanism.@*METHODS@#MDA-MB-231 cells were treated with 1, 3 or 5 mmol/L melatonin, and the changes in cell proliferation were examined using CCK-8 assay. Colony-forming assay and wound healing assay were used to assess the effects of melatonin treatmnent on colony-forming ability and migration of the cells. Flow cytometry and immunofluoresnce assay were employed to examine apoptosis and positive staining for autophagy-related proteins in the cells treated with 3 mmol/L melatonin. The effects of melatonin treatment alone or in combination with 3-methyladenine (3-MA) on the expressions of the proteins associated with autophagy (LC3, P62 and Beclin1), apoptosis (Bcl2 and Bax) and epithelial-mesenchymal transition (E-cadherin and Snail) were examined with Western blotting.@*RESULTS@#Melatonin treatment significantly inhibited the proliferation of breast cancer cells in a concentration- and time-dependent manner (P < 0.05), suppressed colony-forming ability and migration (P < 0.01), and promoted apoptosis of the cells (P < 0.01). Melatonin treatment alone significantly increased the expressions of Bax (P < 0.05), E-cadherin, LC3-II/LC3-I, and Beclin1 and lowered the expressions of Bcl2 (P < 0.05), Snail, P62 (P < 0.05), and Bcl2/Bax ratio (P < 0.01) in the cells, and caused enhanced positive staining of Beclin1 protein and attenuated staining of P62 protein. Compared with melatonin treatment alone, melatonin treatment combined with 3-MA significantly decreased the expressions of Beclin1 (P < 0.001), LC3-II/LC3-I (P < 0.05), Bax (P < 0.01), and E-cadherin (P < 0.001) and increased the expressions of Bcl2 (P < 0.05), Snail, and Bcl2/Bax ratio (P < 0.01).@*CONCLUSION@#Melatonin can induce autophagy of MDA-MB-231 breast cancer cells to inhibit cell proliferation and metastasis and promote cell apoptosis, and suppressing autophagy can weaken the inhibitory effect of melatonin on the growth and metastasis of breast cancer cells.
Subject(s)
Female , Humans , Autophagy , Autophagy-Related Proteins/metabolism , Breast Neoplasms , Cell Line, Tumor , Melatonin/pharmacologyABSTRACT
AIM:To discuss the efficacy and safety of orthokeratology with reducing back optic zone diameter(5mm-BOZD)compared with conventional back optic zone diameter(6mm-BOZD)in the treatment of adolescent myopia.METHODS: A prospective randomized controlled trial was performed. There were 100 cases with 100 eyes of adolescent myopia(all right eye data were taken)selected from April 2016 to January 2019, the spherical degree was -1.00--5.00D. Then they were randomly divided into the two groups. The experimental group wore 5mm-BOZD orthokeratology, and the control group wore 6mm-BOZD orthokeratology. Their axis length(AL), spherical equivalent(SE), relative peripheral refraction(RPR), best corrected visual acuity(BCVA), uncorrected near visual acuity(NVA), Efron grading was applied to record the anterior segment of the eyes, corneal hysteresis(CH), corneal resistance factor(CRF), corneal-compensated intraocular pressure(IOPcc), average noninvasive Keratograph tear breakup time(NIKBUTav)and higher order aberration(RMSh) were compared between the two groups during the 1a treatment period.RESULTS: After 1a of treatment, the AL in experimental group increased 0.05±0.05mm,while it increased 0.15±0.05mm(t=-8.949, P<0.001)in control group. The SE in experimental group increased -0.18±0.27D,while it increased-0.42±0.35D(t=3.609, P=0.001)in control group. There were statistical differences in RPR changes at N30°, N20° and T30°sites between the two groups(P<0.05). There were no statistical differences in BCVA,NVA,Efron grade,CH,CRF,IOPcc,NIKBUTav and RMSh between the two groups(P>0.05).CONCLUSION:Reducing back optic zone diameter orthokeratology can correct adolescent myopia safely and more effectively during the observation period.
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Objective:To evaluate the application value of robost optimization of brachytherapy for cervical cancer.Methods:Twenty patients who completed radical treatment were recruited in this study. The dose volume histogram (DVH) parameters were statistically compared between the conventional and robust optimization plans, and the robustness between the conventional and robust optimization plans was evaluated using DVH and DVH bands. The robust optimization method utilized the worst dose distribution to consider the dose in the presence of uncertainties. In each optimization iteration, the dose distributin when the radioactive source shifted along the X, Y, and Z directions (±2 mm), and the dose distribution when the radioactive source was not shifted were calculated. The worst dose distribution for each voxel was the lowest dose in the target and the highest dose outside the target under all circumstances. The iterative objective function was calculated by the worst dose distribution.Results:In the scenario of no shifting of radioactive source position, the mean value of robust optimization was significantly lower and that of V 150% was significantly higher than those of conventional optimization (both P<0.05). When considering the shifting of radioactive source position, the worst dosimetric parameters of multiple dose distributions were statistically compared. The mean HR-CTV D 100% values did not significantly differ between the robust and conventional optimization plans, whereas the mean D 90% value (range: 0.02-0.03 Gy) of robust optimization was significantly higher than that of conventional optimization ( P<0.05). Robust optimization increased the D 2cm 3 of the bladder and small intestine, and the rectum dose was increased with the shifting of the radioactive source position in the robust optimization. The DVH bands did not significantly differ between the conventional and robust optimization plans for all patients. Conclusions:Robust optimization based on the worst dose distribution fails to significantly improve the robustness of brachytherapy for cervical cancer. Alternative methods are required to minimize the dosimetric effect of uncertainties in brachytherapy.
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Objective:To compare the short-term effects of hip muscles strengthening and quadriceps strengthening on knee osteoarthritis (KOA), and discuss the advantages of hip muscles strengthening. Methods:From October, 2015 to May, 2016, 42 old females with KOA were divided into two groups equally. They received hip strengthening (HS group) and quadriceps strengthening (QS group) for two weeks, respectively. The pain, stiffness and physical function scores of Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were measured. Isokinetic strength peak torque (PT) was assessed for knee extensors and flexors, and 6-minute Walk Test was also evaluated. They were followed up two months later. Results:Before exercise, there was no significant difference in all the indexes between two groups (P > 0.05). Two weeks after exercise, the knee flexor PT (t = -4.038, P = 0.001) and 6-minute walk distance (t = -2.474, P = 0.022) increased in QS group; the pain, stiffness and physical function scores of WOMAC (t > 2.487, P < 0.05), the knee extensor and flexor PT (|t| > 6.370, P < 0.001), and 6-minute walk distance (t = -2.241, P = 0.037) improved in HS group; the scores of WOMAC were lower (t > 2.087, P < 0.05) and the knee extensor PT was higher (t = -5.028, P < 0.001) in HS group than in QS group. At two-months' follow-up, the drop-out rate was significantly lower in HS group than in QS group (χ2 = 13.480, P < 0.001). Conclusion:Hip muscles strengthening is a good choice for KOA in the early stage of treatment, which could avoid the pain in quadriceps training, increase quadriceps strength and improve physical function.
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Isomers are widely distributed in Chinese herbal medicines,and can be discriminated by energy-resolved mass spectrometry( ER-MS). However,ER-MS was performed through direct injection of reference compounds with syringe pump,which encountered a significant technical barrier for high-throughput and automated measurements. Herein,online ER-MS was conducted using LC-MS platform,and a pair of isomers,kaempferol vs luteolin,were employed as a case study to illustrate and assess the utility of online ER-MS for isomeric discrimination. High-resolution tandem mass spectrometry data of both flavonoids were acquired on LC-QE-Orbitrap-MS,and the fragmentation pathways responsible for the primary fragment ions were proposed. The primary signal in MS1 occurred at m/z 285( [M-H]-),and the primary signals of either compound generated by retro-Diels-Alder fragmentation were observed at m/z 151 and 133. The spectral information was subsequently transferred onto LC-Qtrap-MS platform to carry out online ER-MS. Two precursor-to-product ion transition candidates were constructed as m/z 285>151 and 285>133,and either afterward derived a set of pseudo-ion transitions( PITs) and so forth,exactly corresponding to a series of progressive collision energies( eg-5,-8,-11 e V,and so on). All PITs were typed into the monitoring list of multiple reaction monitoring program to generate the peak area datasets. Either dataset was normalized using the highest values in the set and imported into Graph Pad Prism software to plot the Gaus-sian-shaped curve that was termed as the break-down graph. The apex of the regressive curve was termed as optimal collision energy( OCE). The OCE values corresponding to m/z 285>151 were calculated as-29. 06 e V and-35. 71 e V for kaempferol and luteolin,respectively. In the case of m/z 285>133,the OCEs were yielded as-44. 15 e V for kaempferol and-49. 01 e V for luteolin. With re-ference to their chemical structures,the location of hydroxyl group was regarded to be responsible for the differences of either m/z 285>151 or 285>133 between the isomers,attributing to their different bond properties. Above all,online ER-MS offers an eligible tool for isomeric discrimination,and provides meaningful information for the accurate chemical composition characterization based on LC-MS,which is not limited to Chinese herbal medicines.
Subject(s)
Chromatography, Liquid , Flavonoids , Kaempferols , Luteolin , Tandem Mass SpectrometryABSTRACT
@#AIM: To observe the changes of relative peripheral refraction(RPR)after wearing orthokeratology(OK)lens, and to explore the relationship between the changes of RPR and the axial length(AL).<p>METHODS: Totally 104 cases of adolescent myopia(-1.00D to -6.00D)were selected from May 2016 to Nov. 2018. Then they were randomly divided into the experimental group and the control group. The experimental group wore OK lens, and the control group wore frame glasses. Their AL, RPR(N30°-T30°)were observed for 1a.<p>RESULTS:The RPR of the experimental group showed myopic drift at each time point after wearing OK lens(<i>P</i><0.05), and the change was most obvious in 1mo(<i>P</i><0.05). After 1mo, the RPR basically tended to be stable(<i>P</i>>0.05). The RPR of the control group showed an increase in hyperopia. One year later, there were statistical differences in the changes of AL and RPR between the two groups(<i>P</i><0.001). There was a positive correlation between the changes of AL and RPR in the experimental group(<i>P</i><0.001).<p>CONCLUSION: After wearing OK lens, the AL growth slowed down, while the RPR showed myopic drift and it was most obvious in 1mo. There was a correlation between the changes of AL and RPR.
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Intestinal microecology is an important defense system in the human body. The intestinal flora is the core micro-ecosystem in the human intestine. It has a symbiotic relationship with the overall functions of the body. It has strong metabolic activity to maintain the normal functioning of the body and resist the invasion of various viral antigens in the body. Playing a protective function,the imbalanced intestinal microecology can cause various diseases. Polysaccharides can be extracted from a wide range of sources and have low toxicity and side effects. They have attracted wide attention because of their anti-tumor, anti-oxidant, anti-inflammatory and other biological activities. Studies have demonstrated that polysaccharides can regulate intestinal microecological disorders. According to the studies in recent years, this review summarizes that polysaccharides mainly modulate intestinal microecological disorders through regulating the composition of intestinal flora, improving the metabolism of the flora, and repairing the intestinal tract barrier. On the basis of these mechanisms of action, this paper elaborates the anti-tumor, immunomodulatory, and anti-inflammatory activities of polysaccharides. This paper can provide reference for the future research on the intestinal microecology-regulating mechanism and biological activities of polysaccharides.
Subject(s)
Humans , Anti-Inflammatory Agents , Ecosystem , Gastrointestinal Microbiome , Intestines , Polysaccharides/pharmacologyABSTRACT
Knee osteoarthritis is a common chronic degenerative disease in the elderly. Its occurrence and development are closely related to biomechanical factors. The force of knee joint is affected by different factors, such as joint morphology, lower limb alignment, muscle contractions, external load, soft tissue traction and so on. Due to the limitation of in vivo measurement, biomechanical parameters based on motion analysis techniques have been widely used in clinical research. At present, biomechanical parameters which are widely studied and applied in clinical research include knee adduction moment, knee adduction impulse, knee flexion moment, and knee varus thrust. It is important to observe the changes of knee joint biomechanical parameters during the occurrence and development of knee osteoarthritis for researching etiology, diagnosis, intervention and treatment.
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Objective@#To report an implementation method and results of an independent brachytherapy dose verification software (DVS).@*Methods@#The DVS was developed based on Visual C+ + and the modular structure design was adopted. The DICOM RT files exported from the treatment planning system (TPS) were automatically loaded into the DVS. The TG-43 formalism was employed for dose calculation. Six cervical cancer patients who underwent brachytherapy were retrospectively selected to test the DVS. Different applicators were utilized for each patient. Dosimetric parameters and γ analysis (0.1cm, 5%) were used to evaluate the dose difference between the DVS and the TPS.@*Results@#Compared with the TPS dose, the γ pass rates of the doses calculated by the DVS were higher than 98%. For CTV, the dosimetric differences were less than 0.29% and 0.53% for D100% and D90%. For bladder, rectum and sigmoid, the agreement of D0.1cm3, D1cm3 and D2cm3 within a 0.5% level.@*Conclusion@#With minimal human-computer interactions, the DVS can verify the accuracy of dose calculated by TPS for brachytherapy.
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Objective:To explore an implementation method and results of an inverse dose optimization algorithm (gradient-based planning optimization, GBPO) in three-dimensional brachytherapy.Methods:A standard quadratic objective function was used in the GBPO. The optimization code of GBPO was performed based on LBFGS (Limited memory Broyden Fletcher Goldberg Shanno). Seven cervical cancer patients using different applicators and 15 cervical cancer patients using the Fletcher applicator (Nucletron part#189.730) were retrospectively analyzed. The plan quality of GBPO was firstly assessed by isodose lines, then dose-volume histogram (DVH) parameters of CTV(D 100%, V 150%) and organs at risk(D 0.1cm 3, D 1.0cm 3, D 2.0cm 3) were used to evaluate the difference among the GBPO, IPSA and Graphic plans. Results:For the 7 patients using different applicators, GBPO could optimize the conformal dose distribution, and the DVH parameters of the target and organs at risk were basically the same among the GBPO, IPSA and Graphic plans. For 15 patients using the Fletcher applicator, the difference in DVH parameters between the GBPO and IPSA plans was not statistically significant. There was no remarkable difference in the DVH parameters between the GBPO and Graphic plans, but the D 100% of the GBPO plan was significantly higher ( P<0.01), and the V 150% was significantly lower ( P<0.01) than that of the Graphic plan. Conclusions:The quality of the GBPO plan is similar to that of the IPSA plan in terms of target coverage and organ protection. The inverse dose optimization algorithm GBPO can be integrated into a three-dimensional brachytherapy treatment planning system.
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Objective To report an implementation method and results of an independent brachytherapy dose verification software (DVS).Methods The DVS was developed based on Visual C++ and the modular structure design was adopted.The DICOM RT files exported from the treatment planning system (TPS) were automatically loaded into the DVS.The TG-43 formalism was employed for dose calculation.Six cervical cancer patients who underwent brachytherapy were retrospectively selected to test the DVS.Different applicators were utilized for each patient.Dosimetric parameters and γ analysis (0.1 cm,5％) were used to evaluate the dose difference between the DVS and the TPS.Results Compared with the TPS dose,the γ pass rates of the doses calculated by the DVS were higher than 98％.For CTV,the dosimetric differences were less than 0.29％ and 0.53％ for D100％ and D90％.For bladder,rectum and sigmoid,the agreement of D0.1cm3,D1cm3 and D2cm3 within a 0.5％ level.Conclusion With minimal human-computer interactions,the DVS can verify the accuracy of dose calculated by TPS for brachytherapy.
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Objective:To report an implementation method and result of an inverse dose optimization algorithm (GBPO) that can control the dwell time variation in three-dimensional brachytherapy.Methods:The GBPO used a quadratic objective function. A dwell time modulation item was added to the objective function to restrict the dwell time variation, and a DTMF (dwell time modulation factor) was used to adjust the dwell time variation. A retrospective study was made of 15 cervical cancer patients treated using the Fletcher applicator. The relationship between the DTMF and dwell time deviation was analyzed. Dose-volume histogram (DVH) parameters of HR-CTV ( D100%, V150%) and organs at risk (OARs) ( D0.1 cm 3, D1 cm 3, D2 cm 3) were used to evaluate the difference between the GBPO plans and the commercial treatment plan system (using the IPSA algorithm) plans. Results:When the DTMF was less than 20, the dwell time deviation decreased quickly. However, after the DTMF increased to 100, and the dwell time deviation had no remarkable change. The D100% of GBPO plan was higher than that of IPSA plan (3.63±0.36 vs. 3.53±0.34, t=2.45, P<0.05), and the difference in other dosimetric parameters between the GBPO plans and the IPSA plans was not statistically significant ( P>0.05). Conclusions:The method reported in this study to control the dwell time variation was feasible. The GBPO plans have a comparable quality as the IPSA plans for the studied cervical cancer cases. The GBPO algorithm could be integrated into a three-dimensional brachytherapy treatment planning system.