This article expounds the method of quality control and quality assurance for the isocenter of the medical linear accelerator and explains the content and standards of its regular examinations, in order to ensure the safety and efficiency in use.
Particle Accelerators ; standards ; Quality Control ; Radiation Oncology ; instrumentation ; standards

This article expounds the quality assurance for the radiotherapy simulator. Emphasis is given to its necessities and the methods, and standards of regular examinations are illustrated for the aim of meeting the requirements of the quality assurance in radiotherapy by the WHO.
Quality Assurance, Health Care ; Quality Control ; Radiotherapy ; instrumentation

Reduced radiosensitivity of lung cancer cells represents a pivotal obstacle in clinical oncology. The hypoxia-inducible factor (HIF)-1α plays a crucial role in radiosensitivity, but the detailed mechanisms remain elusive. A relationship has been suggested to exist between hypoxia and autophagy recently. In the current study, we studied the effect of hypoxia-induced autophagy on radioresistance in lung cancer cell lines. A549 and H1299 cells were cultured under normoxia or hypoxia, followed by irradiation at dosage ranging from 0 to 8 Gy. Clonogenic assay was performed to calculate surviving fraction. EGFP-LC3 plasmid was stably transfected into cells to monitor autophagic processes. Western blotting was used to evaluate the protein expression levels of HIF-1α, c-Jun, phosphorylated c-Jun, Beclin 1, LC3 and p62. The mRNA levels of Beclin 1 were detected by qRT-PCR. We found that under hypoxia, both A549 and H1299 cells were radio-resistant compared with normoxia. Hypoxia-induced elevated HIF-1α protein expression preferentially triggered autophagy, accompanied by LC3 induction, EGFP-LC3 puncta and p62 degradation. In the meantime, HIF-1α increased downstream c-Jun phosphorylation, which in turn upregulated Beclin 1 mRNA and protein expression. The upregulation of Beclin 1 expression, instead of HIF-1α, could be blocked by SP600125 (a specific inhibitor of c-Jun NH2-terminal kinase), followed by suppression of autophagy. Under hypoxia, combined treatment of irradiation and chloroquine (a potent autophagy inhibitor) significantly decreased the survival potential of lung cancer cells in vitro and in vivo. In conclusion, hypoxia-induced autophagy through evaluating Beclin1 expression may be considered as a target to reverse the radioresistance in cancer cells.

[Objective]To investigate the expression changes of miR-133b in methamphetamine(MA)-induced neuro-nal injury in PC12 cells and its regulative effects on cellular apoptosis.[Methods]PC12 cells were cultured and divided into control group and MA treated group.In MA treated group,PC12 cells were insulted with 800μmol/L MA in culture medium. The cellular injury of PC12 cells was observed under microscope. The cellular apoptosis was detected by Hoechst33342/PI double staining,and the expression level of miR-133b was examined by real-time quantitative PCR(RT-PCR). Further-more,miR-133b mimic and inhibitors were transfected into PC12 cells to analyze miR-133b's function in MA-induced cell apoptosis.[Results]The data showed that 800 μmol/L MA could induce obvious cellular injury,cause neurite shortened and increase the cell apoptosis. The RT-PCR data showed that the expression of miR-133b of PC12 cells treated with MA de-creased significantly.The apoptosis rate of PC12 cells decreased after transfection of miR-133b mimic,while increased after transfection of miR-133b inhibitors.[Conclusions]High concentration of MA causes neuron damage and induces neuronal apoptosis,and also decreases the levels of miR-133b expression. Whereas,overexpression of miR-133b can reduce the apoptosis of cultured PC12 cells.Thus,miR-133b plays a crucial role in MA mediated neurotoxicity.This study provides a theoretical basis for elucidating the mechanism of MA-induced neurotoxicity and may provide a new strategy for treating MA addiction.

The clinical data of one case of infantile myofibromatosis of left mandibular angle were analyzed, and the clinicopathological characteristics, imaging diagnosis, treatment and prognosis of infantile myofibromatosis were discussed.
Humans ; Myofibromatosis ; congenital

This case report describes the diagnosis and endodontic therapy of maxillary fused second and third molars, using cone-beam computed tomography (CBCT). A 31-year-old Chinese male, with no contributory medical or family/social history, presented with throbbing pain in the maxillary right molar area following an unsuccessful attempted tooth extraction. Clinical examination revealed what appeared initially to be a damaged large extra cusp on the buccal aspect of the distobuccal cusp of the second molar. However, CBCT revealed that a third molar was fused to the second molar. Unexpectedly, the maxillary left third molar also was fused to the second molar, and the crown of an unerupted supernumerary fourth molar was possibly also fused to the apical root region of the second molar. Operative procedures should not be attempted without adequate radiographic investigation. CBCT allowed the precise location of the root canals of the right maxillary fused molar teeth to permit successful endodontic therapy, confirmed after 6 months.
Adult ; Cone-Beam Computed Tomography ; methods ; Follow-Up Studies ; Fused Teeth ; diagnostic imaging ; Humans ; Image Processing, Computer-Assisted ; methods ; Imaging, Three-Dimensional ; methods ; Male ; Maxilla ; Molar ; abnormalities ; Molar, Third ; abnormalities ; Pulpitis ; diagnostic imaging ; Root Canal Therapy ; Tooth Root ; abnormalities ; Tooth, Supernumerary ; diagnostic imaging ; Tooth, Unerupted ; diagnostic imaging

OBJECTIVETo evaluate the value of the detection of a 4-marker (ER, VIM, CEA and p16) panel in the differential diagnosis of primary endocervical and endometrial adenocarcinomas.

METHODSImmunohistochemical EnVison method was used to detect the expressions of ER, VIM, CEA and p16 in paraffin-embedded tissues from 31 cases of primary endocervical adenocarcinomas and 30 cases of endometrial adenocarcinomas. The specificity, sensitivity, predictive value and accuracy were compared between the 4-marker and 3-marker (ER, VIM and CEA) panels.

RESULTSThe positivity rates of ER, VIM, CEA and p16 in endocervical adenocarcinomas were 35.5%, 19.4%, 77.4% and 67.7%, respectively; those in endometrial adenocarcinomas were 70%, 73.3%, 40% and 13.3%, respectively, showing significant frequency differences (P<0.05) between primary endocervical and endometrial adenocarcinomas. The specificity, sensitivity, positive predictive value and accuracy of the 4-marker panel in endocervical adenocarcinomas were significantly higher than those of the 3-marker panel (96.3% vs 90.2%, 65.1% vs 57.6%, 94.9% vs 89.4%, and 85.8% vs 80.6%, respectively). These values were almost similar for both panels in endometrial carcinoma except for better negative predictive value and accuracy value with the 4-marker panel (58.7% vs 51.9% and 75.4% vs 68.6%, respectively).

CONCLUSIONAdding the p16 marker to the traditional 3-marker panel may have significant clinical importance in the differential diagnosis of primary endocervical and endometrial adenocarcinomas to improve the diagnostic accuracy, although there is only a slight increase in the diagnostic sensitivity.

Adenocarcinoma ; diagnosis ; metabolism ; Adult ; Aged ; Biomarkers, Tumor ; analysis ; Carcinoembryonic Antigen ; analysis ; Cyclin-Dependent Kinase Inhibitor p16 ; Diagnosis, Differential ; Endometrial Neoplasms ; diagnosis ; metabolism ; Female ; Humans ; Middle Aged ; Neoplasm Proteins ; analysis ; Predictive Value of Tests ; Receptors, Estrogen ; analysis ; Sensitivity and Specificity ; Uterine Cervical Neoplasms ; diagnosis ; metabolism ; Vimentin ; analysis

OBJECTIVETo investigate the improvement of taurine (Tau) in learning and memory ability of rats exposed to lead.

METHODSForty Wistar rats were randomly divided into control group: treated with distilled water; lead group: treated with lead acetate (40 mg.kg(-1).d(-1)); lead-taurine group 1, 2, 3: lead acetate (40 mg.kg(-1).d(-1)) + different concentrations of taurine (100, 400, 800 mg.kg(-1).d(-1)). The ability of learning and memory of rats were measured weekly by spatial water maze test from the 5th to 8th week. At the end of the experiment, the rats were killed, the samples of blood and brain were taken for test.

RESULTS(1) The time of seeking anchorage of lead-Tau 800 mg group in the 6th, 7th, 8th week and that of lead-Tau 400 mg group in the 6th week were significantly lower than that of lead group (P<0.05). (2) Blood lead contents in lead-Tau 100 mg and lead-Tau 400 mg group [(510.9 +/- 57.56) microg/L, (485.40 +/- 98.85) microg/L] were different from those in lead group (P<0.05). (3) The content of malondialdehyde (MDA) and the activities of superoxide dismutase (SOD), nitric oxide synthase (NOS), acetylcholinesterase (AChE) in brain of lead-Tau 800 mg group and lead-Tau 400 mg group were also different from those in lead group (P<0.05 or P<0.01). The content of GSH and the activity of GSH-Px in lead-Tau 800 mg group were different from those in lead group (P<0.05) as well.

CONCLUSIONTaurine could improve learning and memory ability of rats exposed to lead and may play a protective role in brain.

Animals ; Brain Chemistry ; drug effects ; Female ; Glutathione ; analysis ; Learning ; drug effects ; Long-Term Potentiation ; drug effects ; Malondialdehyde ; analysis ; Memory ; drug effects ; Neuroprotective Agents ; pharmacology ; Organometallic Compounds ; toxicity ; Rats ; Rats, Wistar ; Taurine ; pharmacology

Background & Objective: Radiotherapy and temozolomide are the standard therapy for newly diagnosed glioblastoma multiforme (GBM). However, it is unclear whether adding another agent to the commonly used radiotherapy-temozolomide (RT + TMZ) benefits newly diagnosed GBM patients. The present network meta-analysis aimed to assess the efficacy of combining other agents with RT + TMZ for GBM treatment. Methods: A comprehensive literature search was conducted on PubMed, EMBASE.com, Web of Science, and the Cochrane Central Register of Controlled Trials from inception to September 23, 2014, to include all randomized controlled trials of RT + TMZ-based therapy in GBM patients. Pairwise and network meta-analyses were performed to compare the therapeutic regimens. Results: Seventeen studies involving 4,148 patients were identified. The results of pairwise meta-analysis indicated no significant differences among most comparison groups, except for bevacizumab + RT + TMZ versus RT + TMZ for progression-free survival (hazard ratio [HR] = 0.71, 95% confidence interval [CI]: 0.59–0.86; P = 0.000) and RT + TMZ versus RT alone for overall survival (HR = 0.71, 95% CI: 0.58–0.88; P = 0.001). The results of network meta-analysis also showed no significant differences in most comparisons; however, adverse events were more common among patients receiving additional therapeutic agents other than RT + TMZ. The ranking probability analysis indicated that bevacizumab + RT + TMZ and nimustine + cisplatin + RT + TMZ were associated with the best progression-free and overall survival, but they also caused the most adverse events in GBM patients. RT + bevacizumab + irinotecan had the highest probability of being the best regimen for minimizing adverse events. Conclusions: The addition of other targeted agents, particularly bevacizumab and nimustine, to RT + TMZ could be slightly effective for the treatment of newly diagnosed GBM patients; however, adverse events remained common.
Glioblastoma

Objective To analyze the death trend of children under 5 years old in Lanzhou and establish the time series model to predict the mortality and incidence of children under 5 years old in Lanzhou in 2019. Methods Descriptive epidemiological method was used to analyze the mortality of children under 5 years old in Lanzhou from January 2010 to December 2018. SPSS 21.0 software was used to construct time series analysis model, selecting the best model and predict the mortality of children under 5 years old in Lanzhou in 2019. Results A total of 1 650 deaths of children under 5 years old were reported in Lanzhou from 2010 to 2018. The number of deaths reported by boys and girls was 871 and 774 respectively, with an average annual mortality rate of 6.23‰. In recent years, the overall mortality rate of children under 5 years old in Lanzhou had declined. The majority of deaths among children under 5 years old were neonates, accounting for 65.27%. Simple seasonal model was the best model by comparing different models. The model could well fit the monthly death cases of children under 5 years old in Lanzhou from 2010 to 2018. It is predicted that the total number of deaths of children under 5 years old in Lanzhou will be 140 in 2019, which is similar to the number of deaths in 2018. Conclusions The mortality rate of children under 5 years old in Lanzhou is decreasing year by year. Simple seasonal model can better reflect the mortality trend of children under 5 years old in Lanzhou and make short-term prediction.