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Medical physicists play an important role in the delivery of radiotherapy. Compared with China′s mainland, Hong Kong has established a more mature training mode and a more complete management system for medical physics talents. In this article, the authors introduced the current state of medical physics talent training, as well as the recruitment, certification and promotion of medical physicist in Hong Kong by querying the official websites of medical physics organizations, reviewing related literature and interviewing senior medical physicists in Hong Kong. The authors also analyzed the shortcomings in the construction of medical physics talent system in China′s mainland and made valuable suggestions.
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From February 1 to April 30, 2021, 48 general practice resident physicians in the First Affiliated Hospital of Naval Medical University were randomly divided into study group and control group with 24 in each group. The common comorbidities of the community-dwelling elderly, namely diabetes, diabetic retinopathy and osteoporosis were selected as teaching cases. The residents in control group received conventional teaching, while the scenario simulation teaching model of multicomorbity co-treatment was applied for the study group. The teaching effect, satisfaction and self-efficacy scores were compared between two groups. After training, the knowledge levels, the mastery of referral indicators and the performance of fundus ophthalmoscopy in the study group were significantly better than those in the control group ( t=2.27, 6.34, 4.09; P<0.05). They were (80.96±11.27) vs. (73.96±10.09), (10.33±2.41) vs. (6.38±1.88), (70.27±10.44) vs. (63.50±7.98), and students′ satisfaction and self-efficacy evaluation were higher than those of the observation group (all P<0.05). It is suggested that the simulation teaching of multi-disease co-treatment scenario is more beneficial than the traditional teaching to improve the comprehensive care ability of standardized training physicians in general practice for patients with chronic disease.
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Hepatocellular carcinoma is one of the common causes of tumor-related death, and it has high morbidity and mortality rates in China. Recent studies have shown that platelets are closely associated with the development of hepatocellular carcinoma. Literature review shows that platelets not only participate in hemostasis, but also act on liver cells and tumor microenvironment, promote the formation of new blood vessels, and participate in the development and progression of hepatocellular carcinoma as a cell mediator through immune response and other pathways. In addition, platelets and their derivatives can be used as potential therapeutic targets for hepatocellular carcinoma. Therefore, antiplatelet therapy is expected to become a new adjuvant strategy for the treatment of hepatocellular carcinoma, which has important clinical significance.
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Objective:To compare the positioning errors of individual head-rest combined with thermoplastic fixation mask versus thermoplastic fixation mask alone in patients with head and neck tumors. Methods:Twenty-eight patients who received irradiation with helical tomotherapy in Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital) between October 2019 and April 2020 were included in this study. They were randomly assigned to receive position fixation with either individual head-rest combined with thermoplastic fixation mask (N1 group, n = 14) or thermoplastic fixation mask alone (N2 group, n = 14). Megavoltage computed tomography (MVCT) scanning registration was used to obtain the positioning errors in translation and rotation (ROLL) in the left-right (X), head-food (Y), and belly-back (Z) directions. There were a total of 841 CT scans, consisting of 425 scans in group N1 and 416 scans in group N2. Results:The positioning errors in X, Y, Z and ROLL directions in the N1 group were (1.37 ± 1.04) mm, (1.38 ± 1.12) mm, (1.47 ± 1.62) mm and (1.47 ± 1.62) ° respectively, and they were (1.57 ± 1.21) mm, (2.10 ± 1.51) mm, (1.61 ± 1.50) mm and (1.40 ± 1.30) ° respectively in the N2 group. There was significant difference in positioning errors in the Y direction between N1 and N2 groups ( P = 0.013). In the N1 group, the outward expansion boundaries in X, Y and Z directions was 4.15 mm, 4.23 mm and 4.81 mm respectively, and it was 4.77, 6.31 and 5.08 mm, respectively in the N2 group. In the X direction, there was significant difference in positioning errors taking 3 mm as the dividing point between N1 and N2 groups ( χ2 = 10.516, P < 0.001). In the Y direction, there was significant difference in positioning errors taking 1, 2 and 3 mm as the dividing points between N1 and N2 groups ( χ2 = 24.889, P < 0.001; χ2 = 42.202, P < 0.001; χ2 = 46.204, P < 0.001). In the Z direction, there was significant difference in positioning errors taking 2 mm as the dividing point between N1 and N2 groups ( χ2 = 7.335, P = 0.007). In the N1 group, the percentage of positioning errors < 3 mm in the X, Y and Z directions was 92%, 90% and 92%, respectively. Conclusion:Compared with thermoplastic fixation mask alone, individual head-rest combined with thermoplastic fixation mask can better effectively improve the positioning stability and reduce positioning errors in patients receiving irradiation with helical tomotherapy for head and neck tumors. The combined method is of certain innovation.
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Aim To research the effects of total flavones of rhododendra(TFR)on transient receptor potential vanilloid receptor 4(TRPV4)in cerebral basilar arteries(CBA)of rats subjected to ischemia/reperfusion(IR)injury.Methods The model of total brain IR was established by four-artery occlusion(4-VO)method in rats.Arterial pressure perfusion and cell membrane potential recording methods were used for surveying the dilatation and hyperpolarization of TFR and ruthenium red(RR,an inhibitor of TRPV4)in the KCl-preconstricted CBA ex vivo in rats subjected to IR.Quantitative real-time polymerase chain reaction(qRT-PCR)and Western blot were utilized to investigate the TRPV4 mRNA and protein expressions of TFR and RR in cerebrovascular endothelial cells of CBA in vivo in rats subjected to IR.Results 11～2 700 mg·L-1 TFR significantly induced concentration-dependent hyperpolarization and dilatation in the KCl-preconstricted CBA in rats subjected to IR.TFR still produced degenerative hyperpolarization and dilatation by removal of endothelium in CBA,which was remarkably attenuated as compared with endothelium-intact group(P<0.01).After removal of NO and PGI2 vasodilatation,TFR obviously elicited the hyperpolarization and dilatation that were further decreased by RR(an inhibitor of TRPV4)in IR CBAs.TFR pretreatment apparently increased the level of TRPV4 mRNA and protein expressions in IR CBAs.These effects were restrained by RR,an inhibitor of TRPV4.Conclusions TFR could mediate endothelium-dependent and endothelium-independent effects.The endothelium-derived dilatation may be related to the increase of endothelium activity and endothelium-derived hyperpolarizing factor(EDHF)generation and release that have been promoted by TFR,and secondarily activating TRPV4,which results in Ca2+ inflow and subsequent hyperpolarization of vascular smooth muscle cell membrane and vasorelaxation.
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At present,reports at home and abroad suggest a low probability of successful preservation of ovarian endocrine function after ovarian shift radiotherapy.After radiotherapy for cervical carcinoma,the ovarian function is associated with various factors,such as radiotherapy dose and method,patient's age,shift position,and concurrent chemotherapy drugs.Therefore,as for each patient,the dose to the ovarian tissue should be controlled within the individual dose limit to effectively preserve the ovarian function.
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Objective To assess the variation in patient setup corrections for three different anatomic treat-ment sites using daily pretreatment megavoltage CT(MVCT)in helical tomotherapy,and to analyze alternative refer-ence margins for specific tumor site.Methods Sixty patients treated for three anatomical sites on helical tomotherapy were analyzed.Daily MVCT was carried out for registration and setup corrections before each treatment fraction.Setup errors and rotational setup corrections from 587 head and neck,500 thoracic,371 abdomen and gynecology MCVT imaging were input to statistical analysis.Incidences of three dimensional vector error lengths were calculated for each anatomic site.Overall distribution histograms of the three -dimensionally error was presented using GraphPad Prism 5.The distributions of systematic and random setup errors were quantitative analyzed and the additional margins required were also taken into account.Results 1 458 MVCT scans were implemented for sixty patients.Head and neck had lower frequencies of translational setup errors than others.Frequency of at least 3mm three -dimensional setup errors for head and neck,thoracic,abdomen and gynecology was 55.3%,70.8%,79.8%,respectively.This fre-quency decreased to 17.5%,40.6%,47.2% if 3D vector distance ≥5mm was scored.Overall systematic errors ranged from -1.4mm to 2.7mm,abdomen and gynecology had the largest setup errors in the vertical direction which was statistically significant(χ2 =19.3,P <0.05).The suggested margins should be increased by 4 -7 mm in three -dimensional direction for head and neck,9 -14mm for thoracic,10 -17mm for abdomen and gynecology.Conclusion Differences in setup corrections are perceived between head and neck,thoracic,abdomen and gynecology.The accura-cy of patient positioning can be improved if pre -treatment daily MVCT scans are put into use.Results from setup cor-rection can provide evidence for tumor treatment margin and improve the accuracy of regular radiotherapy.
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Objective To explore the molecular mechanism of BRAFV600E inducing chromosome instability in Sbcl2 and SK-MEL31 melanoma cells.Methods The endogenous Mps1 in stable Sbcl2-and SK-MEL31-B-RafV600E expression cells were depleted by siRNA approach.To test the effect of B-RafV600E on the centrosome amplification and the formation of multipolar spindles,cells at S-phase with HU-treatment were arrested and then the centrosomes and mitotic spindles structure were detected through immunofluoresence.Results The percentage of B-RafV600E expressing Sbcl2 and SK-MEL31 cells (Sbcl2-B-RafV600E and SKMEL31-B-RafV600E) with centrosome amplification and multipolar spindle was reduced from 36 ％ to 6 ％ when Mps1 was absent.Conclusion B-RafV600E leads to centrosome amplification and multipolar spindle through Mps1,thus results in chromosome instability in Sbcl2 and SK-MEL31 melanoma cells.
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Objective To investigate the role of ECRG2 gene in migration and invasion of human fibrosarcoma HT1080 cells. Methods Tet-on system was used to set up ECRG2-inducible cell clones.Knockdown of ECRG2 gene was done by stably expressing short hairpin RNA (shRNA) specific for ECRG2 mRNA in a highly invasive fibrosarcoma cell line HT1080. The expressions of ECRG2 proteins were detected by Western blotting assay. Wound-healing scrape assay and transwell invasion assay were performed to assess the effect of ECRG2 gene on the invasive properties of HT1080 in vitro. Results The most effective ECRG2siRNA interference and inducible was selected by Western blotting assay. Knockdown of ECRG2 gene significantly promoted the migration and invasion of HT1080 cells while expression of ECRG2 impaired the migration and invasion of HT1080 cells in vitro. Conclusion ECRG2 gene is correlated with the invasive and metastatic potential of fibrosarcoma carcinoma, and expression of ECRG2 induces the inhibition of migration and invasion of HT1080 cell line.
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Objective To investigate the role of ECRG2,a novel tumor suppressor gene,in spindle assembly checkpoint. Methods Using siRNA approach to deplete the expression of ECRG2, using immunofluorescence to test the distribution of ECRG2,using Western blotting to examine the expression cell cycle proteins.Results ECRG2 localized to centrosomes during interphase and kinetochores during mitosis.Further analysis revealed that ECRG2 participates in the spindle assembly checkpoint.Depletion of ECRG2 abolished the spindle assembly checkpoint.Conclusion Our results indicated that ECRG2 is important for ensuring spindle assembly checkpoint,accurate chromosome segregation,and its depletion may contribute to chmmosome instability and aneuploidy in human cancers.
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Objective: To examine the effects of ? carotene and ? tocopherol on LDL oxidation by monocyte derived macrophages from SD rats (in DMEM medium). [WT5FZ]Methods: Macrophages were incubated with LDL in DMEM in which freshly dissoved VE (40,100,200 ?mol/L) and ?C (0.5,1.0,2.0 ?mol/L) had been added. After incubating for 24 h, the mediums were centrifuged to determine TBARS and lipofusin and dienes. [WT5FZ]Results: Supplementation of ? tocopherol significantly decreased TBARS, lipofusin and conjugated dienes production and electrophoretic mobility. Supplementation of ? carotene at 0.5 ?mol/L significantly decreased TBARS, lipofusin and conjugated dienes production and electrophoretic mobility, but other levels showed no effect. Increasing ? carotene concentration to 2.0 ?mol/L in the system increased the lipofusin production compared with control group. ? tocopherol at 200 ?mol/L and ? carotene at 0.5 ?mol/L were the most effective in all dose groups. [WT5FZ]Conclusion: Cell mediated oxidation of LDL can be regulated by antioxidants such as ? tocopherol and ? carotene.