Novel antibacterial drug target against Gram-negative bacteria: lipopolysaccharide transport protein LptDE and its inhibitors / 药学学报

The outer membrane composed predominantly of lipopolysaccharide (LPS) is an essential biological barrier for most Gram-negative (G-) bacteria. Lipopolysaccharide transport protein (Lpt) complex LptDE is responsible for the critical final stage of LPS transport and outer membrane assembly. The structure and function of LptDE are highly conserved in most G- bacteria but absent in mammalian cells, and thus LptDE complex is regarded as an attractive antibacterial target. In recent 10 years, the deciphering of the three-dimensional structure of LptDE protein facilities the drug discovery based on such "non-enzyme" proteins. Murepavadin, a peptidomimetic compound, was reported to be the first compound able to target LptD, enlightening a new class of antibacterial molecules with novel mechanisms of action. This article is devoted to summarize the molecular characteristics, structure-function of LptDE protein complex and review the development of murepavadin and related peptidomimetic compounds, in order to provide references for relevant researches.

Progress in molecular signal pathway of dental fluorosis / 中华地方病学杂志

Dental fluorosis is a manifestation of chronic oral fluorosis caused by excessive fluoride intake in childhood. At present, the molecular mechanism of dental fluorosis is still unclear. Ameloblasts are the most sensitive cells to fluoride in tooth tissue. Fluoride affects the proliferation and secretion of ameloblasts through the role of key molecules in the molecular signal pathways, leading to the formation of dental fluorosis. This paper reviews the relationship between the molecular signal pathways [mitogen-activated protein kinase (MAPK), transforming growth factor-β (TGF-β)/Smad, Wnt, Foxo1/Runx2], stress pathways (endoplasmic reticulum stress and oxidative stress) and the occurrence of dental fluorosis in recent years, in order to deeply understand the pathogenesis of dental fluorosis at the molecular level, and provide new ideas for the prevention and treatment of dental fluorosis.

Establishment of prediction model for severe acute pancreatitis complicated with abdominal hypertension / 中华胰腺病杂志

Objective:To construct the prediction model of SAP complicated with intra-abdominal hypertension (IAH), and evaluate the prediction efficiency of the model.Methods:The clinical data of 322 SAP patients admitted to the emergency department of Cangzhou Hospital of Integrated Chinese and Western Medicine in Hebei Province from January 2017 to December 2021 were retrospectively analyzed. They were divided into IAH group ( n=153) and control group ( n=169) according to whether they had IAH complications or not. The clinical characteristics and laboratory test results of the two groups were compared. Multifactor logistic step-up regression was used to analyze the risk factors of SAP patients complicated with IAH. A nomogram model for predicting SAP complicated with IAH was established by using R software. The receiver operating characteristic curve (ROC) of the model was plotted, and the area under the curve (AUC) was calculated to evaluate its prediction efficiency. Calibration chart, Hosmer-Lemesshow test and decision curve analysis were used to evaluate the prediction accuracy and clinical application value of the model. The Bootstrap method was applied to verify the model internally. Results:In IAH group, cases with body mass index, CRP, procalcitonin (PCT), WBC, acute physiological and chronic health assessmentⅡ (APACHEⅡ) score, modified CT Severity Index score (MCTSI), incidence of complications (abdominal effusion, abdominal infection, gastrointestinal dysfunction, shock, multiple organ dysfunction syndrome), mechanical ventilation, the number of high-volume fluid reactivation (24 h≥4 L) were more than those in control group; serum albumin and serum calcium in IAH group were lower than those in control group, and the differences were statistically significant (all P value <0.05). Multivariate logistic regression analysis showed that serum albumin ( OR=0.815, 95% CI 0.710-0.937), CRP ( OR=1.005, 95% CI 1.002-1.008), MCTSI ( OR=2.043, 95% CI 1.695-2.463), complication of gastrointestinal dysfunction ( OR=4.179, 95% CI 2.170-8.049), and high-volume fluid resuscitation ( OR=4.265, 95% CI 2.269-8.015) were independent risk factors for IAH in SAP.The Nomogram prediction model was established using the five factors above as parameters, and the AUC value for predicting IAH complication was 0.886. The Hosmer-Lemesshow test showed a high consistency between the prediction results and the actual clinical observation results ( P=0.189). The results of decision curve analysis showed that the prediction probability of the model was between 10% and 85%, which could bring more benefits to patients. Conclusions:The early prediction model of SAP with concurrent IAH is successfully established, which can better predict the risk of SAP with concurrent IAH.

Application of a novel modified Blumgart anastomosis in laparoscopic pancreaticoduodenectomy / 中国医师进修杂志

Objective:To investigate the efficacy and safety of a novel modified Blumgart pancreaticojejunostomy in laparoscopic pancreaticoduodenectomy (LPD).Methods:Between May 2021 and January 2022, 13 successive cases from Lihuili Hospital Affiliated to Ningbo University who underwent LPD were enrolled in this retrospective study. The study retrospectively analyzed the demographic characteristics, perioperative outcomes, and pathological results of these cases.Results:Twenty patients underwent LPD success-fully and one required conversion to open surgery. The operative time was (308.6 ± 61.7) min. The duration for PJ was (26.7 ± 4.3) min. The estimated blood loss was (188.1 ± 94.2) ml. The postoperative hospital stay was (14.2 ± 3.5) d. There was one case of biochemical leakage and no case of grade B or grade C pancreatic fistula.Conclusions:The new method is safe, simple and feasible. The novel method could reduce the incidence of pancreatic fistula and other complications after LPD.

Study the change of serum osteosclerotin and Dickkopf-3 expression in elderly patients with intertrochanteric fracture / 中国医师进修杂志

Objective:To investigate the changes of perioperative serum osteosclerosis protein (SOST) and Dickkopf-3 (Dkk-3) in elderly patients with femoral intertrochanteric fracture.Methods:Thirty elderly patients who underwent reduction and fixation of femoral intertrochanteric fracture in Baoding Second Hospital from May 2017 to December 2017 were prospectively selected as the observation group; 30 healthy subjects in the same period were selected as the healthy control group. Enzyme linked immunosorbent assay (ELISA) was used to detect the expression of serum SOST and Dkk-3 at 1 d before operation and at 1, 3, 5 d after operation and compared with the same period of healthy physical examination(normal control group). Spearman rank correlation analysis was used to analyze the correlation between SOST and Dkk-3 and disease activity score (ASDAS) and spinal imaging evaluation score (mSASSS).Results:There was a positive correlation between Dkk-3 level and ASDAS score in the observation group ( r = 0.331, P = 0.012); the level of SOST was negatively correlated with the scores of ASDAS ( r = - 0.162, P = 0.017). The levels of serum SOST and Dkk-3 in the observation group were lower than those in the healthy control group: 1.29(1.00, 2.40) μg/L vs. 1.96(1.63, 2.65) μg/L, (6.11 ± 1.15) μg/L vs. (9.81 ± 1.76) μg/L, P<0.05. The levels of serum SOST and Dkk-3 in the observation group increased first and then decreased on the 1st, 3rd and 5th day after operation. The level of serum Dkk-3 increased to the highest level on the 3rd day after operation, and then decreased gradually, but it was still slightly higher than that before operation. The level of serum SOST in the observation group increased to the highest level 1st day after operation, and decreased at 3rd and 5th day after operation. The perioperative serum levels of SOST and Dkk-3 in the observation group were positively correlated, the correlation coefficient was the largest at 1 day after operation ( r = 0.571) and the lowest before operation ( r = 0.119). Conclusions:The perioperative serum levels of SOST and Dkk-3 in elderly patients with femoral intertrochanteric fracture increased first and then decreased. The change of serum SOST level is more sensitive and can be used as a sensitive index to reflect the change of osteogenic ability.

Effect of Plasmacytoid Dendritic Cell Dose in Grafts on CMV Infection after Allogeneic Hematopoietic Stem Cell Transplantation / 中国实验血液学杂志

OBJECTIVE@#To investigate the correlation between plasmacytoid dendritic cell (pDC) dose in grafts and the occurrence of cytomegalovirus (CMV) infection after allogeneic hematopoietic stem cell transplantation (allo-HSCT).@*METHODS@#The clinical data of 80 children who received allo-HSCT in Children's Hospital of Soochow University from August 20, 2020 to June 11, 2021 were retrospectively analyzed. Proportions of DC subsets and T-cell subsets in grafts were detected by flow cytometry in order to calculate infused cell dose of each cell. Weekly monitoring of CMV-DNA copies in peripheral blood for each child were performed after transplantation. The last follow-up date was December 31, 2021.@*RESULTS@#All the children gained hematopoietic reconstitution. CMV infection was observed in 51 children (63.8%±5.4%) within the first 100 days after transplantation, including 2 cases developing CMV disease. Univariate analysis indicated that infused doses of DC and pDC were significantly associated with CMV infection within 100 days after allo-HSCT (P <0.05). Multivariate analysis indicated that a high dose infusion of pDC was an independent protective factor for CMV infection within 100 days after allo-HSCT (P <0.05). By the end of follow-up, 7 children died of transplantation-related complications, including 2 deaths from CMV disease, 2 deaths from extensive chronic graft-versus-host disease, and 3 deaths from capillary leak syndrome. The overall survival rate was 91.2%.@*CONCLUSION@#The pDC in grafts may be associated with early infection of CMV after allo-HSCT, while a high infused pDC dose may serve as a protective factor for CMV infection after transplantation.

Analysis of ARX gene variant in a child with X-linked lissencephaly with abnormal genitalia / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical characteristics and genetic basis for a child with X-linked lissencephaly with abnormal genitalia (XLAG).@*METHODS@#A child with XLAG who had presented at the Third Affiliated Hospital of Zhengzhou University in May 2021 was selected as the study subject. Peripheral blood samples of the child and his parents were collected and subjected to high-throughput sequencing. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the result was analyzed by using bioinformatic software.@*RESULTS@#The child was found to have harbored a hemizygous c.945_948del variant in exon 2 of the ARX gene, which as a frameshifting variant has resulted in a truncated protein. His mother was found to be heterozygous for the variant, whilst his father was of wild type. The variant was unreported previously.@*CONCLUSION@#The hemizygous c.945_948del variant of the ARX gene probably underlay the XLAG in this patient. Above finding has provided a basis for the diagnosis and genetic counseling for this family.

Mechanism of Zhenwu Decoction in improving renal inflammatory injury in mice with DN of spleen-kidney Yang deficiency syndrome by regulating ROCK/IKK/NF-κB pathway / 中国中药杂志

To investigate the intervention effect and mechanism of Zhenwu Decoction on diabetic nephropathy(DN) mice of spleen-kidney Yang deficiency syndrome based on the Rho-associated coiled-coil kinase(ROCK)/IκB kinase(IKK)/nuclear factor-κB(NF-κB) pathway. Ninety-five 7-week-old db/db male mice and 25 7-week-old db/m male mice were fed adaptively for one week. The DN model of spleen-kidney Yang deficiency syndrome was induced by Dahuang Decoction combined with hydrocortisone by gavage, and then the model was evaluated. After modeling, they were randomly divided into a model group, high-dose, medium-dose, and low-dose Zhenwu Decoction groups(33.8, 16.9, and 8.45 g·kg~(-1)·d~(-1)), and an irbesartan group(25 mg·kg~(-1)·d~(-1)), with at least 15 animals in each group. The intervention lasted for eight weeks. After the intervention, body weight and food intake were measured. Serum crea-tinine(Scr), blood urea nitrogen(BUN), fasting blood glucose(FBG), urinary albumin(uALb), and urine creatinine(Ucr) were determined. The uALb/Ucr ratio(ACR) and 24 h urinary protein(UTP) were calculated. Renal pathological morphology was evaluated by HE staining and Masson staining. The levels of key molecular proteins in the ROCK/IKK/NF-κB pathway were detected by Western blot. Enzyme-linked immunosorbent assay(ELISA) was used to detect interleukin-1β(IL-1β), interleukin-6(IL-6), interleukin-8(IL-8), interleukin-10(IL-10), and tumor necrosis factor-α(TNF-α). Compared with the blank group, the model group showed increased content of BUN, uALb, and SCr, increased values of 24 h UTP and ACR, decreased content of Ucr(P<0.05), enlarged glomeruli, thickened basement membrane, mesangial matrix proliferation, inflammatory cell infiltration, and collagen fiber deposition. The protein expression of ROCK1, ROCK2, IKK, NF-κB, phosphorylated IKK(p-IKK), phosphorylated NF-κB(p-NF-κB), and phosphorylated inhibitor of NF-κB(p-IκB) increased(P<0.05), while the protein expression of inhibitor of NF-κB(IκB) decreased(P<0.05). The levels of inflammatory factors IL-1β, IL-6, IL-8, and TNF-α increased(P<0.05), while the level of IL-10 decreased(P<0.05). Compared with the model group, the groups with drug treatment showed decreased levels of BUN, uALb, SCr, 24 h UTP, and ACR, increased level of Ucr(P<0.05), and improved renal pathological status to varying degrees. The high-and medium-dose Zhenwu Decoction groups and the irbesartan group showed reduced protein expression of ROCK1, ROCK2, IKK, NF-κB, p-IKK, p-NF-κB, and p-IκB in the kidneys(P<0.05), increased protein expression of IκB(P<0.05), decreased levels of serum inflammatory factors IL-1β, IL-6, IL-8, and TNF-α(P<0.05), and increased level of IL-10(P<0.05). Zhenwu Decoction can significantly improve renal function and renal pathological damage in DN mice of spleen-kidney Yang deficiency syndrome, and its specific mechanism may be related to the inhibition of inflammatory response by down-regulating the expression of key molecules in the ROCK/IKK/NF-κB pathway in the kidney.

N6-Methyladenosine Methyltransferase METTL3 Alleviates Diabetes-Induced Testicular Damage through Modulating TUG1/Clusterin Axis

Background@#The present study investigated the regulatory effects of N6-methyladenosine (m6A) methyltransferase like-3 (METTL3) in diabetes-induced testicular damage. @*Methods@#In vivo diabetic mice and high glucose (HG) treated GC-1 spg cells were established. The mRNA and protein expressions were determined by real-time quantitative polymerase chain reaction, Western blot, immunofluorescence and immunohistochemistry staining. Levels of testosterone, blood glucose, cell viability, and apoptosis were detected by enzyme-linked immunosorbent assay, MTT, and flow cytometry, respectively. Molecular interactions were verified by RNA immunoprecipitation and RNA pull-down assay. Histopathological staining was performed to evaluate testicular injury. @*Results@#METTL3 and long non-coding RNA taurine up-regulated 1 (lncRNA TUG1) were downregulated in testicular tissues of diabetic mice and HG-treated GC-1 spg cells. METTL3 overexpression could reduce the blood glucose level, oxidative stress and testicular damage but enhance testosterone secretion in diabetic mouse model and HG-stimulated GC-1 spg cells. Mechanically, METTL3-mediated m6A methylation enhanced the stability of TUG1, then stabilizing the clusterin mRNA via recruiting serine and arginine rich splicing factor 1. Moreover, inhibition of TUG1/clusterin signaling markedly reversed the protective impacts of METTL3 overexpression on HG-stimulated GC-1 spg cells. @*Conclusion@#This study demonstrated that METTL3 ameliorated diabetes-induced testicular damage by upregulating the TUG1/clusterin signaling. These data further elucidate the potential regulatory mechanisms of m6A modification on diabetes-induced testicular injury.

Elevated Levels of Naturally-Occurring Autoantibodies Against the Extracellular Domain of p75NTR Aggravate the Pathology of Alzheimer's Disease / 神经科学通报·英文版

The extracellular domain (p75ECD) of p75 neurotrophin receptor (p75NTR) antagonizes Aβ neurotoxicity and promotes Aβ clearance in Alzheimer's disease (AD). The impaired shedding of p75ECD is a key pathological process in AD, but its regulatory mechanism is largely unknown. This study was designed to investigate the presence and alterations of naturally-occurring autoantibodies against p75ECD (p75ECD-NAbs) in AD patients and their effects on AD pathology. We found that the cerebrospinal fluid (CSF) level of p75ECD-NAbs was increased in AD, and negatively associated with the CSF levels of p75ECD. Transgenic AD mice actively immunized with p75ECD showed a lower level of p75ECD and more severe AD pathology in the brain, as well as worse cognitive functions than the control groups, which were immunized with Re-p75ECD (the reverse sequence of p75ECD) and phosphate-buffered saline, respectively. These findings demonstrate the impact of p75ECD-NAbs on p75NTR/p75ECD imbalance, providing a novel insight into the role of autoimmunity and p75NTR in AD.

Mechanisms of cholesterol metabolism imbalance in a PA-induced non-alcoholic fatty liver disease cell model / 中国药科大学学报

@#Liver cholesterol metabolism disorder plays an important role in the development of non-alcoholic fatty liver disease (NAFLD).In order to reveal the molecular mechanism of cholesterol homeostasis imbalance induced by saturated fatty acids, HepG2 cells were stimulated with palmitic acid (PA).Lipids accumulation was analyzed by Oil Red O staining, intracellular triglyceride and cholesterol quantification.The level of genes and proteins related to cholesterol homeostasis was measured by RT-qPCR and western blotting.Additionally, intracellular bile acids and mitochondrial oxysterols were detected by LC-MS/MS.The results demonstrated that intracellular lipids such as TG and TC were significantly increased in the model with PA stimulation.Although no significant difference was detected in genes related to cholesterol synthesis and uptake, the protein expression of ABCG5 and LXRα were significantly down-regulated, indicating a decrease in cholesterol efflux.Meanwhile, the gene expression of STARD1 and CYP7B1, which are responsible for bile acid alternative synthesis, were markedly enhanced, along with a significant increase of cholesterol and 27-OHC in mitochondria and CDCA in cells.These results suggested that PA overload may disrupt cholesterol homeostasis by inhibiting cholesterol efflux and promoting bile acids synthesis.

Anti-tumor activity and mechanisms of IDO1 inhibitor in combined treatment with temozolomide on human glioma cell lines / 药学学报

We analyzed the anticancer effect and mechanism of the novel indoleamine 2,‍3-dioxygenase 1 (IDO1) inhibitor NLG-919 combined with temozolomide (TMZ) on human glioma cell lines. The anti-tumor activity of NLG-919 and temozolomide after single and combined treatments was detected by MTT assay. Colony formation assay, invasion assay and migration assays were used to detect the effects of NLG-919 and temozolomide alone or in combination on proliferation, invasion and migration of human glioma cells. A flow cytometry assay was used to detect cell apoptosis, cell cycle arrest, reactive oxygen species (ROS) production and mitochondrial membrane potential damage (JC-1). An immunofluorescence assay was used to detect the expression level of IDO1 and HPLC was used to detect the expression level of L-kynurenine (Kyn) to explore the anti-tumor mechanism of NLG-919 and temozolomide. The results show that NLG-919 had a weak in vitro inhibitory effect compared to that of temozolomide. The IC50 of NLG-919 on U251 cells and U87 after 72 h was 26.9 and 30.7 μmol·L-1, respectively. However, when NLG-919 was used in combination with temozolomide, its anti-glioma activity was significantly increased. Compared with the single treatment, the combination treatment had a potent ability to inhibit proliferation, invasion and migration of glioma cells. Combination treatment improved the capacity of temozolomide to induce cell cycle arrest and inhibit the growth of glioma cells. NLG-919 significantly down-regulated the expression and activity of IDO1 in glioma cells, and the inhibitory effect was improved after combination with temozolomide, and effectively blocked the production of Kyn through the metabolism of L-tryptophan (Trp). In conclusion, the IDO1 inhibitor NLG-919 and temozolomide showed synergistic effects in the anticancer therapy of human glioma cell lines.

Practical value and thought on "co-regulation of body and mind" in treatment of post-stroke spasticity with acupuncture / 中国针灸

This paper reviews the application of "co-regulation of body and mind" of acupuncture for post-stroke spasticity. It is found that acupoints on the head and the back of the governor vessel, as well as Jiaji (Ex-B 2) points are mainly used for regulating the mind, and the local sites of spastic muscles and the points on the antagonistic muscles are for regulating the body specially. It is believed that regulating the mind should be integrated with regulating the body, while, the acupoint selection be associated with needling methods so as to fully achieve the "co-regulation of body and mind" and enhance the practical value of acupuncture for post-stroke spasticity. It is proposed that the classical anti-spastic needling techniques, such as huici (relaxing needling) and guanci (joint needling), should be more considered.

Ultrasound-guided Radial Artery Cannulation / 中国医学科学院学报

Arterial cannulation can be used to monitor blood pressure in real time and facilitate frequent arterial blood gas analysis.It is one of the commonly used clinical techniques in anesthesia,emergency,and intensive care units.Studies have demonstrated that ultrasound guidance can increase the success rate of arterial cannulation and reduce the incidence of related complications.In recent years,ultrasound guidance technology has developed rapidly and is increasingly used in clinical practice.This article reviews the latest advances in the application of ultrasound guidance in radial artery cannulation.

Laparoscopic or robotic serosa muscular layer circumferential incision combined with mucosal layer cutting and closure for gastrointestinal mesenchymal tumors at difficult sites of the stomach / 中华普通外科杂志

Objective:To evaluate the use of serosa muscular layers circumferential incision combined with mucosal layer cutting and closure by laparoscopic or robotic surgery for gastrointestinal mesenchymal tumors at difficult sites of the stomach.Methods:From Jul 2019 to Apr 2021, 18 gastric mesenchymal tumor patients undergoing serosa muscular layers circumferential incision combined with mucosal layer cutting and closure by laparoscopic or robotic surgery at the Department of Surgery, the Fourth Hospital of Hebei Medical University were retrospectively analyzed.Results:All 18 patients had successful surgery, including 7 cases of robotic surgery, 11 cases of laparoscopic surgery, and there was no conversion to open surgery. Tumors were at the gastric in cardia, 8 cases at the gastric body and lesser curvature in 4 cases, and at the gastric antrum in 6 cases, respectively. Eleven cases were of endogenous and 7 cases were of dumbbell type. The average operation time was (99±29) min, the intraoperative blood loss was (10±5) ml, the first time taking food per mouth was (2.0±1.0) d, and the postoperative hospital stay was (4.9 ± 1.2) d. Pathology showed gastrointestinal stromal tumor in 11 cases, leiomyoma in 5 cases and schwannoma in 2 cases. All were with negative margins. The average tumor diameter was (4.7±1.4) cm. The median follow-up time was 16.5 months, and there was no sign of tumor recurrence or metastasis.Conclusion:The serosa muscular layers circumferential incision combined with mucosal layer cutting and closure technique in laparoscopic or robotic surgery is a safe and feasible procedure for treating gastrointestinal mesenchymal tumor at difficult sites of the stomach.

Application of project-based learning in clinical teaching of radiation physics for radiotherapy residents / 中华放射肿瘤学杂志

Objective:To observe the effect of project-based learning (PBL) in the clinical teaching of radiation physics.Methods:Thirty-two residents specializing in radiotherapy were included in the study. In the experimental group ( n=16), PBL was adopted, while traditional clinical teaching method was employed in the control group ( n=16). After the rotation, the assessment was conducted, as well as a questionnaire survey was performed, including five aspects: overall satisfaction, understanding of radiation physics knowledge, learning motivation, learning burden, and learning efficiency. Results:The assessment score in the experimental group was 86.31±5.41, which was higher than 75.28±5.91 in the control group, and the difference was statistically significant. Residents in the experimental group were satisfied with the effect of PBL.Conclusion:Compared with the traditional teaching method, PBL can improve the learning motivation, efficiency, and performance of radiotherapy residents, which is highly recognized by the residents.

Radiation shielding for the intraoperative radiotherapy using low energy X-rays / 中华放射医学与防护杂志

Objective:To assess the shielding requirements of low energy X-ray intraoperative radiotherapy room under the domestic and foreign standards and guidelines, to measure the sured transmission factors for a range of shielding materials, the ambient dose equivalent rate around concerned positions and the shielding effect of protective devices, so as to provide references for shielding design of such radiotherapy units and applications of radiological protection devices.Methods:The required shielding thicknesses for a treatment room with INTRABEAM intraoperative radiotherapy system were calculated under the Chinese national standard GBZ 121, IPEM report No. 75 and NCRP report No. 151, respectively. The transmission factors for a range of shielding materials including solid water slab, shielding sheet and shielding apron were measured. Moreover, the ambient dose equivalent rates were measured under the simulated working conditions and the shielding effectiveness of a lead screen was evaluated.Results:The required lead thicknesses calculated under different standards and guidelines were less than 0.6 mm for all the concerned points, with the differences at sub-millimeter level. The low energy X-rays generated by this equipment attenuated rapidly in the shielding materials. The measured transmission factors of 0.05 mm lead equivalent shielding sheet and 0.25 mm lead equivalent shielding apron were 0.068 and 0.003 8, respectively. When the radiation was delivered using spherical applicator without any attenuation, the ambient dose equivalent rates at 1 m and 2 m from the X-ray source were 10.7 and 2.6 mSv/h, respectively. The corresponding measurement values decreased to 3.8 and 0.9 μSv/h, respectively, when the spherical applicator was inserted into a small water tank. Meanwhile, the ambient dose equivalent rate at 2 m was reduced to the background level when using protective screen.Conclusions:The shielding requirements for a low energy X-ray intraoperative radiotherapy facility are minimal, with low effective energy of X-rays generated by this equipment, but the dose rate close to the unshielded radiation source is high. The shielding scheme of treatment room should be optimized in design and the protective device should be used in a reasonable way.

Preoperative prediction of Ki-67 expression status in breast cancer based on dynamic contrast enhanced MRI radiomics combined with clinical imaging features model / 中华放射学杂志

Objective:To investigate the value of preoperative prediction of Ki-67 expression status in breast cancer based on multi-phase enhanced MRI combined with clinical imaging characteristics prediction model.Methods:This study was retrospective. A total of 213 breast cancer patients who underwent surgical treatment at Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College between June 2016 and May 2017 were enrolled. All patients were female, aged 24-78 (51±10) years, and underwent routine breast MRI within 2 weeks prior to surgery. According to the different Ki-67 expression of postoperative pathological results, patients were divided into high expression group (Ki-67≥20%, 153 cases) and low expression group (Ki-67<20%, 60 cases). The radiomic features of breast cancer lesions were extracted from phase 2 (CE-2) and phase 7 (CE-7) images of dynamic contrast enhanced (DCE)-MRI, and all cases were divided into training and test sets according to the ratio of 7∶3. The radiomic features were first selected using ANOVA and Wilcoxon signed-rank test, followed by the least absolute shrinkage and selection operator method regression model. The same method of parameters selection was applied to clinical information and conventional imaging features [including gland classification, degree of background parenchymal enhancement, multifocal/multicentric, lesion location, lesion morphology, lesion long diameter, lesion short diameter, T 2WI signal characteristics, diffusion-weighted imaging (DWI) signal characteristics, apparent diffusion coefficient (ADC) values, time-signal intensity curve type, and axillary lymph nodes larger than 1 cm in short axis]. Support vector machine (SVM) was then used to construct prediction models for Ki-67 high and low expression states. The predictive performance of the models were evaluated using receiver operating characteristic (ROC) curves and area under cueve(AUC). Results:Totally 1 029 radiomic features were extracted from CE-2 and CE-7 images, respectively, and 9 and 7 best features were obtained after selection, respectively. And combining the two sets of features for a total of 16 features constituted the CE-2+CE-7 image best features. Five valuable parameters including lesion location, lesion short diameter, DWI signal characteristics, ADC values, and axillary lymph nodes larger than 1 cm in short axis, were selected from all clinical image features. The SVM prediction models obtained from the radiomic features of CE-2 and CE-7 images had a high AUC in predicting Ki-67 expression status (>0.70) in both the training set and the test set. The models were constructed by combining the CE-2, CE-7, and CE-2+CE-7 radiomic features with clinical imaging features, respectively, and the corresponding model performance in predicting Ki-67 expression status was improved compared with the models obtained by using the CE-2, CE-7, and CE-2+CE-7 radiomic features alone. The SVM prediction model obtained from CE-2+CE-7 radiomic features combined with clinical imaging features had the best prediction performance, with AUC of 0.895, accuracy of 84.6%, sensitivity of 87.9%, and specificity of 76.2% for predicting Ki-67 expression status in the training set and AUC of 0.822, accuracy of 70.3%, sensitivity of 76.1%, and specificity of 55.6% in test sets.Conclusion:The SVM prediction model based on DCE-MRI radiomic features can effectively predict Ki-67 expression status, and the combination of radiomic features and clinical imaging features can further improve the model prediction performance.

Molecular mechanism of fluoride toxicity to ameloblasts based on bioinformatics method / 中华地方病学杂志

Objective:To explore the molecular mechanism of fluoride toxicity to ameloblasts.Methods:Mouse ameloblast cell line (LS8 cells) was taken and divided into control group [0.0 mmol/L sodium fluoride (NaF)] and fluoride exposed group (1.6 mmol/L NaF) according to the final concentration of NaF. Transcriptome sequencing was performed to screen differentially expressed genes (DEGs), and gene ontology (GO) analysis and gene set enrichment analysis (GSEA) were performed on DEGs. The STRING database was used to construct the protein-protein interaction (PPI) network of DEGs, and Cytoscape 3.8.0 software was used to visualize the PPI network to screen key modules and key genes. At the same time, real-time fluorescence quantitative PCR was used to detect the mRNA expression level of key genes, and the key genes were verified by gene expression database (GEO database).Results:Compared with the control group, there were 709 DEGs in the fluoride exposed group, including 223 up-regulated genes and 486 down-regulated genes. The GO analysis of DEGs mainly involved molecular functions such as receptor-ligand activity, cell adhesion molecule binding, structural components of extracellular matrix, cellular components such as collagen of extracellular matrix, receptor complex, membrane raft, biological processes such as external packaging structure organization, extracellular structure organization, and extracellular matrix organization. The GSEA of the whole gene set found that the interleukin-17 (IL-17) signaling pathway, ribosome biogenesis in eukaryotes, and the nuclear factor kappa-B (NF-κB) signaling pathway were activated, while fatty acid degradation, pyruvate metabolism and fatty acid metabolism were inhibited. After constructing PPI network, three key modules and four key genes [typeⅠcollagen α1 (Col1a1), typeⅠcollagen α2 (Col1a2), typeⅤcollagen α1 (Col5a1) and fibrinogen 1 (Fbn1)] were obtained. Compared with the control group, the mRNA expression levels of Col1a1, Col1a2, Col5a1 and Fbn1 in LS8 cells of the fluoride exposed group were significantly decreased ( P < 0.05), which was consistent with the change trend of gene expression in the GEO database. Conclusion:Key genes such as Col1a1, Col1a2, Col5a1, Fbn1, and signaling pathways such as IL-17 and NF-κB, which are screened by bioinformatics method, may be closely related to the toxic effects of fluoride on ameloblasts.

Research progress on the prognostic value of the ratio of lymphocytes to C-reactive protein in digestive system neoplasms / 国际肿瘤学杂志

Tumor-associated inflammation is closely related to the development of tumors. The ratio of lymphocytes to C-reactive protein (LCR) is a new marker reflecting the inflammatory state of the body, which plays an important role in predicting the prognosis of digestive system neoplasms. Compared with the detection of lymphocytes or C-reactive protein alone, this marker has higher sensitivity and accuracy, and can provide a new direction for clinical diagnosis and treatment of digestive system neoplasms.