Objective To measure radiation filed distribution in the treatment room of the Varian Halcyon medical linear accelerator, and to provide a basis for shielding design and potential exposure analysis of treatment rooms for this type of accelerator. Methods Under the 6 MV X-ray (FFF) mode at a maximum dose rate of 800 MU/min and a maximum irradiation field of 28.00 cm × 28.00 cm, a total of 540 MU was delivered during gantry rotation. Radiation field distribution was measured using thermoluminescence dosimeters located at multiple points in the room. The measured data were then applied to shielding calculations, and the results were compared with those obtained using empirical formulas. Results The overall radiation levels in the treatment room were in the range of 12.2 µGy/540 MU to 5.520 Gy/540 MU, with the highest dose (5.520 Gy/540 MU) observed at the isocenter, and the lowest dose (12.2 µGy/540 MU) recorded at approximately 6.5 m from the gantry head. The radiation levels at most points were within the range of 100-1000 µGy/540 MU. At heights of 0.5, 1.1, and 1.7 m, the radiation field exhibited a rapid attenuation from the beam center outward, with a faster decay along the treatment couch direction (Y-axis) than along the perpendicular direction (X-axis). Shielding calculations based on the measured radiation field yielded required wall thicknesses of 1219 mm (east wall), 949 mm (south wall), 1235 mm (west wall), and 1252 mm (north wall), all of which were smaller than those calculated using empirical formulas. Conclusion Thermoluminescence dosimeter is suitable for multi-point in situ measurement of radiation field distribution in Halcyon accelerator treatment rooms. The measurement results can be used to optimize the shielding design of Halcyon accelerator treatment rooms.

Ferroptosis is a new programmed cell death dependent on iron ions.Ferroptosis can be induced by endogenous or exogenous pathways,and cells exhibit specific cell morphological signs and are regulated by a variety of molecular mechanisms.In recent years,more and more studies have shown that ferroptosis plays an important role in the treatment of cancer.This article summarizes the mechanism of ferroptosis in bladder cancer and the regulation of cancer cells,as well as the role of ferroptosis-related factors,non-coding RNA regulation,N6-methyladenosine(m6A),amino acid metabolism and autophagy dependent ferroptosis in the growth and proliferation of bladder cancer,with a view to provide new strategies for the treatment of bladder cancer.

Endodontic diseases are a kind of chronic infectious oral disease.Common endodontic treatment concepts are based on the removal of inflamed or necrotic pulp tissue and the replacement by gutta-percha.However,it is very essential for endodontic treatment to debride the root canal system and prevent the root canal system from bacterial reinfection after root canal therapy(RCT).Recent research,encompassing bacterial etiology and advanced imaging techniques,contributes to our understanding of the root canal system's anatomy intricacies and the technique sensitivity of RCT.Success in RCT hinges on factors like patients,infection severity,root canal anatomy,and treatment techniques.Therefore,improving disease management is a key issue to combat endodontic diseases and cure periapical lesions.The clinical difficulty assessment system of RCT is established based on patient conditions,tooth conditions,root canal configuration,and root canal needing retreatment,and emphasizes pre-treatment risk assessment for optimal outcomes.The findings suggest that the presence of risk factors may correlate with the challenge of achieving the high standard required for RCT.These insights contribute not only to improve education but also aid practitioners in treatment planning and referral decision-making within the field of endodontics.

Chemical cleaning and disinfection are crucial steps for eliminating infection in root canal treatment.However,irrigant selection or irrigation procedures are far from clear.The vapor lock effect in the apical region has yet to be solved,impeding irrigation efficacy and resulting in residual infections and compromised treatment outcomes.Additionally,ambiguous clinical indications for root canal medication and non-standardized dressing protocols must be clarified.Inappropriate intracanal medication may present side effects and jeopardize the therapeutic outcomes.Indeed,clinicians have been aware of these concerns for years.Based on the current evidence of studies,this article reviews the properties of various irrigants and intracanal medicaments and elucidates their effectiveness and interactions.The evolution of different kinetic irrigation methods,their effects,limitations,the paradigm shift,current indications,and effective operational procedures regarding intracanal medication are also discussed.This expert consensus aims to establish the clinical operation guidelines for root canal irrigation and a position statement on intracanal medication,thus facilitating a better understanding of infection control,standardizing clinical practice,and ultimately improving the success of endodontic therapy.

Objective:To evaluate the effect of niraparib, the poly (ADP-ribose) polymerase (PARP) inhibitor, on the radiosensitivity of esophageal squamous cell carcinoma (ESCC) and to preliminarily investigate its mechanism.Methods:Human esophageal squamous cell carcinoma cells ECA-109 and KYSE-150 were divided into the control, niraparib, single irradiation, combined (niraparib+irradiation) groups. Cell proliferation was measured by CCK-8 assay. The changes of cell survival rate were detected by colony formation assay. The changes of cell cycle and apoptosis were analyzed by flow cytometry. The number of γH2AX foci was detected by immunofluorescence, and the expression levels of PARP-1, cleaved-PARP, RAD51, mitogen-activated protein kinase (MAPK) [extracellular signal-regulated kinase 1 and 2 (ERK1/2) ] and p-MAPK (ERK1/2) proteins were determined by Western blot. All data were expressed as Mean±SD. Data between two groups conforming to normal distribution through the normality test were subject to independent sample t-test and multiple groups were analyzed using one-way ANOVA. Results:In human ESCC cells ECA-109 and KYSE-150, the proliferation of ESCC cells was significantly inhibited by niraparib combined with irradiation, and the values of average lethal dose (D 0), quasi-threshould dose(D q), survival fraction after 2 Gy irradiation (SF 2) in the combined group were decreased compared with those in the single irradiation group. The effect of irradiation alone on apoptosis of ECA-109 and KYSE-150 cells was limited. Compared to single irradiation group, irradiation combined with niraparib further increased the apoptosis rate in ESCC cells ( P=0.015, P=0.006). In ECA-109 cells, G 2/M phase arrest was significantly increased in combined group compared with irradiation alone group ( P<0.001). In ECA-109 cells, the number of γH2AX foci in combined group was higher than that in the single irradiation group after 2 h, and showed a significantly slower decay of γH2AX foci ( P<0.001). Moreover, niraparib combined with irradiation enhanced the radiation-induced cleavage of PARP-1 and down-regulated the expression of Rad51 and p-MAPK(ERK1/2). Conclusion:Niraparib can increase the radiosensitivity of esophageal cancer cells by inhibiting cell proliferation, promoting cell apoptosis, inhibiting the repair of DNA damage and regulating the MARK-ERK signaling pathway.

The dental operative microscope has been widely employed in the field of dentistry, particularly in endodontics and operative dentistry, resulting in significant advancements in the effectiveness of root canal therapy, endodontic surgery, and dental restoration. However, the improper use of this microscope continues to be common in clinical settings, primarily due to operators' insufficient understanding and proficiency in both the features and established operating procedures of this equipment. In October 2019, Professor Jingping Liang, Vice Chairman of the Society of Cariology and Endodontology, Chinese Stomatological Association, organized a consensus meeting with Chinese experts in endodontics and operative dentistry. The objective of this meeting was to establish a standard operation procedure for the dental operative microscope. Subsequently, a consensus was reached and officially issued. Over the span of about four years, the content of this consensus has been further developed and improved through practical experience.
Humans ; Dentistry, Operative ; Consensus ; Endodontics ; Root Canal Therapy ; Dental Care

Digital guided therapy (DGT) has been advocated as a contemporary computer-aided technique for treating endodontic diseases in recent decades. The concept of DGT for endodontic diseases is categorized into static guided endodontics (SGE), necessitating a meticulously designed template, and dynamic guided endodontics (DGE), which utilizes an optical triangulation tracking system. Based on cone-beam computed tomography (CBCT) images superimposed with or without oral scan (OS) data, a virtual template is crafted through software and subsequently translated into a 3-dimensional (3D) printing for SGE, while the system guides the drilling path with a real-time navigation in DGE. DGT was reported to resolve a series of challenging endodontic cases, including teeth with pulp obliteration, teeth with anatomical abnormalities, teeth requiring retreatment, posterior teeth needing endodontic microsurgery, and tooth autotransplantation. Case reports and basic researches all demonstrate that DGT stand as a precise, time-saving, and minimally invasive approach in contrast to conventional freehand method. This expert consensus mainly introduces the case selection, general workflow, evaluation, and impact factor of DGT, which could provide an alternative working strategy in endodontic treatment.
Humans ; Consensus ; Endodontics/methods* ; Tooth ; Printing, Three-Dimensional ; Dental Care ; Cone-Beam Computed Tomography ; Root Canal Therapy

Objective:To explore the clinical and histopathologic features of lupus nephritis (LN) patients with positive antineutrophil cytoplasmic antibody (ANCA), so as to provide more theoretical basis to recognize and treat this disease.Methods:Clinical data of biopsy-proven LN patients with ANCA test in the First Affiliated Hospital of Sun Yat-sen University from November 1, 2002 to September 11, 2020 were collected and analyzed retrospectively. The difference of clinical data, laboratory examination, and pathological examination of renal biopsy between ANCA-positive group and ANCA-negative group. The clinicopathological characteristics between different ANCA serotypes were compared.Results:A total of 1 304 patients with LN confirmed by renal biopsy and ANCA test results were enrolled. Eighty ANCA-positive patients from 1 304 LN patients were screened. There are 55(68.8%) ANCA-positive LN patients with positive anti-myeloperoxidase antibodies (MPO). There were 14(17.5%) ANCA-positive LN patients with positive anti-proteinase 3 antibodies (PR3), and 11(13.8%) ANCA-positive patients with double positive antibodies of MPO and PR3. ANCA-positive LN patients had significantly higher serum creatinine [135.5(68.0, 361.8) μmol/L vs 88.0(64.0, 165.0) μmol/L, P=0.004] and blood urea nitrogen [12.35(6.35, 21.18) mmol/L vs 8.60 (5.50, 15.70) mmol/L, P=0.026] as well as lower estimated glomerular filtration rate [45.70(13.83, 84.10) ml·min -1·(1.73 m 2) -1 vs 66.75(38.43, 96.22) ml·min -1·(1.73 m 2) -1, P=0.001] than ANCA-negative patients (stratified sampling of 160 patients). ANCA-positive LN patients had higher chronicity index than ANCA-negative LN patients [3(2, 7) vs 2(0, 5), P=0.006]. There were statistically significant difference in hemoglobin, serum creatinine and estimated glomerular filtration rate among ANCA-positive group, ANCA-negative group, and MPO-ANCA and PR3-ANCA double positive group. MPO-ANCA and PR3-ANCA double positive LN patients had the lowest hemoglobin and estimated glomerular filtration rate, and highest serum creatinine among the three groups (all P<0.05). Conclusions:ANCA-positive LN patients have worse renal function and higher renal histological chronicity index than ANCA-negative LN patients, especially for patients with double positive MPO-ANCA and PR3-ANCA. More stringent monitoring and therapy may be needed in this subgroup of LN patients.

The poly ADP-ribose polymerase (PARP) is a class of nuclear enzymes highly expressed in eukaryotic cells and plays a key role in DNA damage repair. In recent years, PARP inhibitors have shown great potential in tumor therapy, and several PARP inhibitors have been approved by the FDA for maintenance therapy of a variety of cancers. PARP inhibitors mainly inhibit PARP enzymes and PARP trapping, resulting in the persistence of DNA single strand breaks, which are converted to double strand breaks during DNA replication. Studies have shown that PARP inhibitors not only have a significant anti-tumor effect, but also have a synergistic effect with radiotherapy. This paper reviewed the potential theoretical basis of PARP inhibitor combined with radiotherapy, summarized the recent progress of preclinical and clinical research on PARP inhibitors in tumor radiotherapy, sorted out the urgent problems in this field, and looked into the application prospect of PARP inhibitors in anti-tumor therapy.

Objective:To explore the surgical technique and efficacy of pure retroperitoneoscopic extravesical standardized seeable (P.R.E.S.S.) technique for bladder cuff excision (BCE).Methods:Ninety five patients with UTUC from five domestic centers (30 cases from Changzheng Hospital, 21 cases from Peking University First Hospital, 20 cases from Yuhuangding Hospital, 21 cases from Dalian Medical University affiliated No.2 Hospital and 3 cases from General Hospital of Eastern Theater Command)between August 2017 and December 2020 were retrospectively analyzed. There were 57 males and 38 females with a mean age of (67.7±10.0) years and median tumor size of 3.0 cm. All patients underwent pure retroperitoneoscopic radical nephroureterectomy with a single surgical position and four (36 cases) or five (59 cases) trocar layout according to the surgeon’s prefer habit and experience. The demographics of the two groups were the age of [(66.3±11.2)years vs. (68.6±9.1)years], male/female ratio of (25/11 cases vs. 32/27 cases), body mass index of [(25.0± 3.0)kg/m 2 vs. (24.8±3.4)kg/m 2], tumor maximum diameter of [2.8(1.6, 3.5)cm vs. 3.0(2.0, 4.0)cm], left/right side tumor of(19/17 cases vs. 34/25 cases), T 1-2/T 3-4/Tis stage of(25/10/4 cases vs. 49/10/0 cases), and multifocal tumors of(3 cases vs. 2 cases), and the difference was not statistically significant( P>0.05). On the other hand, the differences of hydronephrosis of the operated kidney(13 cases vs. 39 cases, P=0.004), and tumor location (in renal pelvis or calyx or upper/middle/lower ureter being 23/9/4 cases vs. 35/4/20 cases, P=0.005), were statistically significant. The umbilical artery cord was used as anatomical landmark in the process of P. R.E.S.S. bladder cuff excision. The pelvic floor and extraperitoneal space around the ureter were expanded, the bladder wall was opened to form pneumovesicum, and a sufficient bladder cuff resection and exact bladder cuff closure was performed. Perioperative outcomes and follow-up data were analyzed, and the clinical outcomes between the four and five trocars were compared to evaluate the impact of trocar layout on the surgical outcomes. Results:There were 91(95.8%) cases successfully undergoing P. R.E.S.S. BCE technique, with one case converted to open BCE due to bleeding and three cases converted to distal ureter Hem-o-lok clipping because of poor exposure. Median operative time was 180(125, 230)min, and estimated blood loss was 100(50, 100)ml. The overall complication rate was 10.5%(10/95), including 2 cases(2.1%) of intraoperative bleeding, with 1 case treated by transfusion (400 ml), the other case converted to open surgery without transfusion. There were 8 cases of postoperative complications(8.4%), including 7 cases of Clavien-Dindo grade Ⅱ(3 cases of secondary hemorrhage, one case for each of drug allergy, acute renal insufficiency, blood creatinine increased to 490 μmol/L, or lung infection with lymphatic leakage), 1 case of grade Ⅲa(intestinal obstruction treated with insertion of the intestinal obstruction catheter under local anesthesia), and all these patients were discharged smoothly. The difference between the four and five trocars was not statistically significant in the following variables, including the rate of surgical conversion(8.3% vs. 1.7%), estimated intraoperative blood loss(100 ml vs. 60 ml), ratio of intraoperative lymph node dissection (25.0% vs.20.3%), P. R.E.S.S. bladder cuff excision success rate(91.7% vs.98.3%), the incidence of intraoperative and postoperative complications (13.8% vs.8.5%), pT 1-2/pT 3-4/pTis stage(22/11/3 cases vs.37/19/3 cases) and the proportion of recurrence or metastasis(8.3% vs.3.4%)(all P>0.05). However, the differences in the operation time(190 min vs.170 min, P=0.011)and postoperative hospital stay(5 d vs.6 d, P=0.005) were statistically significant. Conclusions:P. R.E.S.S. bladder cuff resection technique is safe and feasible during the procedure of pure retroperitoneoscopic radical nephroureterectomy by a single surgical position and facilitates seeable adequate bladder cuff excision by establishing an enlarged pelvic lateral extraperitoneal space and pneumovesicum. Five-trocar technique is more suitable for patients with lower ureteral tumors but may be associated with a longer postoperative hospital stay compared with the four-trocar technique.