ML162 derivatives incorporating a naphthoquinone unit as ferroptosis/apoptosis inducers: Design, synthesis, anti-cancer activity, and drug-resistance reversal evaluation

Activating apoptosis has long been viewed as an anti-cancer process, but recently increasing evidence has accumulated that induction of ferroptosis has emerged as a promising strategy for cancer therapeutics. Glutathione peroxidase 4 (GPX4) is one of the pivotal factors regulating ferroptosis that targeted inhibition or degradation of GPX4 could effectively trigger ferroptosis. In this study, a series of ML162-quinone conjugates were constructed by using pharmacophore hybridization and bioisosterism strategies, with the aim of obtaining more active anticancer agents via the ferroptosis and apoptosis dual cell death processes. Of these compounds, GIC-20 was identified as the most active one that exhibited promising anticancer activity both in vitro and in vivo via ferroptosis and apoptosis dual-targeting processes, without obvious toxicity compared with ML162. On one hand, GIC-20 could trigger ferroptosis in cells by inducing intracellular lipid peroxide and ROS accumulation, and destroying mitochondrial structure. In addition to GPX4 inhibition, GIC-20 can also trigger ferroptosis via proteasomal-mediated degradation of GPX4, suggesting GIC-20 may function as a molecule glue degrader. On the other hand, GIC-20 can also induce apoptosis via upregulating the level of apoptotic protein Bax and downregulating the level of anti-apoptotic protein Bcl-2 in HT1080 cells. Furthermore, GIC-20 also enhanced the sensitivity of resistant MIA-PaCa-2-AMG510R cells to AMG510, suggesting the great potential of GIC-20 in overcoming the acquired resistance of KRASG12C inhibitors. Overall, GIC-20 represents a novel dual ferroptosis/apoptosis inducer warranting further development for cancer therapeutics and overcoming drug resistance.

Neuroprotection Role of Vitamin C by Upregulating Glutamate Transporter-1 in Auditory Cortex of Noise-Induced Tinnitus Animal Model

Vitamin C (Vc) plays a pivotal role in a series of pathological processes, such as tumors, immune diseases, and neurological disorders. However, its therapeutic potential for tinnitus management remains unclear. In this study, we find that Vc relieves tinnitus in noise-exposed rats. In the 7-day therapy groups, spontaneous firing rate (SFR) increases from 1.17 ± 0.10 Hz to 1.77 ± 0.15 Hz after noise exposure. Vc effectively reduces the elevated SFR to 0.99 ± 0.07 and 0.55 ± 0.05 Hz at different doses. The glutamate level in auditory cortex of noise-exposed rats (3.78 ± 0.42 μM) increases relative to that in the control group (1.34 ± 0.22 μM). High doses of Vc (500 mg/kg/day) effectively reduce the elevated glutamate levels (1.49 ± 0.28 μM). Mechanistic studies show that the expression of glutamate transporter 1 (GLT-1) is impaired following noise exposure and that Vc treatment effectively restores GLT-1 expression in the auditory cortex. Meanwhile, the GLT-1 inhibitor, dl-threo-beta-benzyloxyaspartic acid (dl-TBOA), invalidates the protection role of Vc. Our finding shows that Vc substantially enhances glutamate clearance by upregulating GLT-1 and consequently alleviates noise-induced tinnitus. This study provides valuable insight into a novel biological target for the development of therapeutic interventions that may prevent the onset of tinnitus.

Synthesis and evaluation of WK-X-34 derivatives as P-glycoprotein (P-gp/ABCB1) inhibitors for reversing multidrug resistance

The emergence of multidrug resistance (MDR) in malignant tumors is one of the leading threats encountered currently by many chemotherapeutic agents. A proposed strategy to overcome MDR is to disable the efflux function of P-glycoprotein (P-gp/ABCB1), a critical member of the ABC transporter family that significantly increases the efflux of various anticancer drugs from tumor cells. In this study, structural modification of a third-generation P-gp inhibitor WK-X-34 based on bioisosteric and fragment-growing strategies led to the discovery of the adamantane derivative PID-9, which exhibited the best MDR reversal activity (IC50 = 0.1338 μM, RF = 78.6) in this series, exceeding those of the reported P-gp inhibitors verapamil and WK-X-34. In addition, compared with WK-X-34, PID-9 showed decreased toxicity to cells. Furthermore, the mechanism studies revealed that the reversal activity of adamantane derivatives PID-5, PID-7, and PID-9 stemmed from the inhibition of P-gp efflux. These results indicated that compound PID-9 is the most effective P-gp inhibitor among them with low toxicity and high MDR reversal activity, which provided a fundamental structural reference for further discovery of novel, effective, and non-toxic P-gp inhibitors.

MSC-derived exosomes protect auditory hair cells from neomycin-induced damage via autophagy regulation

BACKGROUND

Sensorineural hearing loss (SNHL) poses a major threat to both physical and mental health; however, there is still a lack of effective drugs to treat the disease. Recently, novel biological therapies, such as mesenchymal stem cells (MSCs) and their products, namely, exosomes, are showing promising therapeutic potential due to their low immunogenicity, few ethical concerns, and easy accessibility. Nevertheless, the precise mechanisms underlying the therapeutic effects of MSC-derived exosomes remain unclear.

RESULTS

Exosomes derived from MSCs reduced hearing and hair cell loss caused by neomycin-induced damage in models in vivo and in vitro. In addition, MSC-derived exosomes modulated autophagy in hair cells to exert a protective effect. Mechanistically, exogenously administered exosomes were internalized by hair cells and subsequently upregulated endocytic gene expression and endosome formation, ultimately leading to autophagy activation. This increased autophagic activity promoted cell survival, decreased the mitochondrial oxidative stress level and the apoptosis rate in hair cells, and ameliorated neomycin-induced ototoxicity.

CONCLUSIONS

In summary, our findings reveal the otoprotective capacity of exogenous exosome-mediated autophagy activation in hair cells in an endocytosis-dependent manner, suggesting possibilities for deafness treatment.

[Comprehensive and full-cycle cancer health management]

In order to realize the "Healthy China 2030" strategic plan, it is necessary to create a new model of all-round and full-cycle cancer health management in line with China's national conditions and the characteristics of the times. Comprehensively strengthen the construction of the whole-chain tumor prevention and control system, shift the front of cancer prevention and treatment to the precancerous cycle, and realize the full-cycle management of accurate screening, regular follow-up, early diagnosis, early treatment and rehabilitation follow-up of cancer patients; all-round interdisciplinary cooperation, strengthen the management of patients with accompanying diseases, and encourage patients to return to society and families in the best condition; comprehensively deploy tumor big data and smart medical care, promote the construction of Internet outpatient clinics and regional medical centers, and develop a three-level linkage palliative care model, Solve a series of problems such as shortage of medical resources and poor homogeneity of medical care.

Critical Values of Daily Sedentary Time and Its Longitudinal Association with Mild Cognitive Impairment Considering APOE ε4: A Prospective Cohort Study

BACKGROUND

Long sedentary time and physical inactivity are negatively related to cognition, but the cut-off value remains unclear, and apolipoprotein E polymorphism ε4 (APOE ε4) is a known genetic risk factor of mild cognitive impairment (MCI).

OBJECTIVES

To explore longitudinal association of sedentary time and MCI, and to identify a cutoff value that increases the risk of developing MCI, taking into account APOE ε4 stratification and its interactions.

DESIGN

A prospective cohort study.

SETTING

Population-based study.

PARTICIPANTS

We included 4932 older adults from Tianjin Elderly Nutrition and Cognition (TENC) cohort study recruited from March 2018 to June 2021 with 3.11 years of median follow-up time.

MEASUREMENTS

The primary outcome was newly diagnosed MCI, which was diagnosed by a modified version of the Petersen's criteria. The information of sedentary time (hours/day) and physical activity (MET-h/week) were obtained by questionnaire. Cox proportional hazard regression models and restricted spline curve were conducted.

RESULTS

A total of 4932 participants were included (mean [SD] age, 67.85 [4.96] years; 2627 female [53.3%] and 2305 male [46.7%]), 740 newly onset MCI patients were identified. Longer sedentary time was associated with higher risk of MCI for all participants (HR:1.069, 95%CI: 1.034, 1.105), especially in APOE ε4 non-carriers (HR:1.083, 95%CI: 1.045, 1.123) whether adjusted potential confounders. Sedentary time had synergistic interactions with APOE ε4 (β:1.503, 95%CI: 1.163, 1.942) and physical activities (β: 1.495, 95%CI: 1.210, 1.846). Restricted spline curve showed a cut-off value of 3.03 hours/day.

CONCLUSIONS

Long sedentary time (≥3.03 hours/day) could increase MCI risk, especially in APOE ε4 non-carriers, people with higher PA, aged 65 and above.

[Dose-dense paclitaxel plus carboplatin in combination with trastuzumab neoadjuvant versus standard adjuvant therapy in human epidermal growth factor receptor-2 positive and hormone receptor negative breast cancer: a prospective cohort study]

Objective: To provide survival evidence of anthracycline-free neoadjuvant chemotherapy for patients with stages Ⅱ-Ⅲ human epidermal growth factor receptor-2 (HER-2) positive and hormone receptor (HR) negative breast cancer. Methods: The prospective cohort study was conducted at the Department of Medical Oncology of Cancer Hospital, Chinese Academy of Medical Sciences. Patients with HER-2 positive and HR negative breast cancer in stages Ⅱ-Ⅲ were enrolled to receive neoadjuvant therapy (NAT) of dose-dense paclitaxel (175 mg/m(2)) plus carboplatin (AUC=4.0) biweekly for 6 cycles in combination with trastuzumab (PCbH), and matched patients who received standard adjuvant therapy of physicians' choice were recruited for survival and safety comparison. Results: From July 2013 to November 2019, 166 patients were included (neoadjuvant 51, adjuvant 115). Compared with those who received adjuvant therapy, patients receiving NAT were younger (<35 years: 19.6% vs 5.2%, P=0.014), had larger tumors (T3: 62.7% vs 7.8%, P<0.001) and more advanced diseases (stage ⅡA: 2.0% vs 41.7%, P<0.001). Patients in the neoadjuvant group all received surgery, and 96 (83.5%) in the adjuvant group received anthracycline-and-taxane-containing regimens. A total of 98 patients (49 pairs) were matched, and the covariates between the two groups were acceptably balanced. Within a median follow-up of 46.5 (range, 14-87) months, the 4-year recurrence-free survival (RFS) rate among patients who received NAT was 73.3% (95% CI: 59.0%-87.6%), versus 80.6% (95% CI: 67.9%-93.3%) among those in the adjuvant group without statistical difference (P=0.418). A similar result was observed for the 4-year overall survival (OS) [neoadjuvant versus adjuvant: 91.5% (95% CI: 81.7%-100.0%) vs 97.8% (95% CI: 93.5%-100.0%), P=0.314]. Compared with standard adjuvant therapy, PCbH was related to less neutropenia and better cardiac safety. Conclusions: These results support the consideration of anthracycline-free neoadjuvant chemotherapy combined with anti-HER-2 therapy for patients with stages Ⅱ-Ⅲ HER-2-positive and HR-negative breast cancer. Optimized regimens with both efficacy and safety are needed and to be further investigated.

B-Cell-Activating Factor Contributes to Elevation of the Content of Regulatory B Cells in Neonatal Sepsis

We studied the role of B cell-activating factor (BAFF) in PI3K/AKT/mTOR signaling pathway in promoting proliferation and maintaining survival of regulatory B lymphocytes (Breg) in newborns with sepsis. The peripheral blood samples were collected from preterm neonates (n=40) diagnosed with sepsis on the day of diagnosis and on days 7, 14, and 21 after diagnosis, as well as from the matched preterm neonates without sepsis (n=40; control group). The peripheral blood mononuclear cells and B cells were isolated, cultured, and stimulated with LPS and immunostimulant CpG-oligodeoxynucleotide (CpG-ODN). Proliferation and differentiation of B-cells into CD19⁺CD24^hiCD38^hi Breg cells and the role of the PI3K/AKT/mTOR signaling pathway in these processes were studied by flow cytometry, real-time quantitative reverse transcription PCR (qRT-PCR), and Western blotting. BAFF levels in the peripheral blood of neonates with sepsis were significantly increased at one week after diagnosis in parallel with increasing trend of expression of BAFF receptor. When applied with LPS and CpG-ODN, BAFF promoted differentiation of B cells into CD19⁺CD24^hiCD38^hi Breg cells. Phosphorylation of 4E-BP1 factor and 70S6K kinase located downstream in PI3K/AKT/mTOR signaling pathway was significantly up-regulated when stimulated with BAFF in combination with LPS and CpG-ODN. Thus, increased level of BAFF activates PI3K/AKT/mTOR signaling pathway and induces in vitro differentiation of peripheral blood B cells into CD19⁺CD24^hiCD38^hi Breg cells.

Design and synthesis of proteolysis-targeting chimeras (PROTACs) as degraders of glutathione peroxidase 4

Ferroptosis is a new type of regulated, non-apoptotic cell death driven by iron-dependent phospholipid peroxidation. Inducing cell ferroptosis by inactivating glutathione peroxidase 4 (GPX4) has been considered as an effective cancer treatment strategy, but only few GPX4 inhibitors have been reported to date. Targeted protein degradation is receiving increasing attention in the discovery and development of therapeutic modality, particularly proteolysis targeting chimeras (PROTACs). Herein, we reported the design, synthesis, and evaluation of different types of GPX4-targeting PROTACs using ML162 derivatives and ligands for CRBN/VHL E3 ligases. Among them, CRBN-based PROTAC GDC-11 showed a relatively balanced biological profile in GPX4 degradation (degradation rate of 33% at 10 μM), cytotoxicity (IC₅₀ = 11.69 μM), and lipid peroxides accumulation (2-foldincreaserelatedtoDMSO), suggesting a typical characteristic of ferroptosis. In silico docking and quantum chemistry theoretical calculations provided a plausible explanation for the moderate degrading effect of these synthesized PROTACs. Overall, this work lays the foundation for subsequent studies of GPX4-targeting PROTACs, and further design and synthesis of GPX4-targeting degrader are currently in progress in our group, which will be reported in due course.

Pose-Driven Realistic 2-D Motion Synthesis

A realistic 2-D motion can be treated as a deforming process of an individual appearance texture driven by a sequence of human poses. In this article, we thereby propose to transform the 2-D motion synthesis into a pose conditioned realistic motion image generation task considering the promising performance of pose estimation technology and generative adversarial nets (GANs). However, the problem is that GAN is only suitable to do the region-aligned image translation task while motion synthesis involves a large number of spatial deformations. To avoid this drawback, we design a two-step and multistream network architecture. First, we train a special GAN to generate the body segment images with given poses in step-I. Then in step-II, we input the body segment images as well as the poses into the multistream network so that it only needs to generate the textures in each aligned body region. Besides, we provide a real face as another input of the network to improve the face details of the generated motion image. The synthesized results with realism and sharp details on four training sets demonstrate the effectiveness of the proposed model.

Deep learning-based approach for the automatic segmentation of adult and pediatric temporal bone computed tomography images

Background

Automatic segmentation of temporal bone computed tomography (CT) images is fundamental to image-guided otologic surgery and the intelligent analysis of CT images in the field of otology. This study was conducted to test a convolutional neural network (CNN) model that can automatically segment almost all temporal bone anatomy structures in adult and pediatric CT images.

Methods

A dataset comprising 80 annotated CT volumes was collected, of which 40 samples were obtained from adults and 40 from children. A further 60 annotated CT volumes (30 from adults and 30 from children) were used to train the model. The remaining 20 annotated CT volumes were employed to determine the model's generalizability for automatic segmentation. Finally, the Dice coefficient (DC) and average symmetric surface distance (ASSD) were utilized as metrics to evaluate the performance of the CNN model. Two independent-sample t-tests were used to compare the test set results of adults and children.

Results

In the adult test set, the mean DC values of all the structures ranged from 0.714 to 0.912, and the ASSD values were less than 0.24 mm for 11 structures. In the pediatric test set, the mean DC values of all the structures ranged from 0.658 to 0.915, and the ASSD values were less than 0.18 mm for 11 structures. There was no statistically significant difference between the adult and child test sets in most temporal bone structures.

Conclusions

Our CNN model shows excellent automatic segmentation performance and good generalizability for both adult and pediatric temporal bone CT images, which can help to advance otologist education, intelligent imaging diagnosis, surgery simulation, application of augmented reality, and preoperative planning for image-guided otology surgery.

[Genetic variations in four geographical isolates of Gohieria fusca based on cytochrome b and internal transcribed spacer genes]

OBJECTIVE

To investigate the genetic diversity and genetic differentiation of different geographical isolates of Gohieria fusca.

METHODS

G. fusca isolates were sampled from Wuhu (WH), Bengbu (BB) and Bozhou cities (BZ) of Anhui Province and Jiaxing City of Zhejiang Province (JX). Mitochondrial cytochrome b (Cytb) and ribosomal internal transcribed spacer (ITS) genes were amplified in WH, BB, BZ and JX isolates of G. fusca using PCR assay. The gene sequences were edited and aligned using the software Chromas 2 and DNASTAR 1.00, and the haplotype, haplotype diversity (Hd) and nucleotide polymorphism (Pi) of each isolate were calculated using the software DnaSP 5.10.00. The genetic differentiation among isolates (F_st) and gene flow value (N_m) were estimated using the software MEGA 10.2, and a phylogenetic tree was built. Tests of neutrality and analysis of molecular variance (AMOVA) were performed using the software Arlequin 3.1 and a haplotype network was built based on the Median-Joining network using the software Network 10.2.

RESULTS

PCR assay showed that the sizes of the Cytb and ITS genes were 372 bp and 1 301 to 1 320 bp, respectively. All four isolates of G. fusca presented high genetic diversity based on mitochondrial Cytb and ITS genes (Hd = 0.804, Pi = 0.006 91). AMOVA showed genetic differentiation among geographical isolates of G. fusca (F_st = 0.202 40, P < 0.05), and the genetic variation was mainly caused by intra-population variations (79.76%). Gene flow analysis showed a high level of gene flow among G. fusca isolates (N_m > 1). Tests of neutrality based on Cytb gene measured a Tajima's D value of -1.796 31 (P < 0.05) and a Fu's FS value of -3.293 98 (P < 0.05) in WH isolate of G. fusca, indicating population expansion in WH isolate of G. fusca. Haplotype network analysis and phylogenetic analysis revealed no remarkable geographical distribution pattern among different geographical isolates of G. fusca. All four isolates of G. fusca presented high genetic diversity (Hd = 0.985, Pi = 0.011 97). AMOVA showed moderate level of genetic differentiation between four isolates (F_st = 0.104 62, P < 0.05). The tests of neutrality based on ITS genes measured a Tajima's D value of -6.088 20 and a Fu's FS value of -1.935 99 (both P > 0.05) in the whole isolate of G. fusca, indicating no obviously population expansion.

CONCLUSIONS

The four geographical isolates of G. fusca have high genetic diversity and remarkable genetic differentiation. Since a high level of gene flow is detected among different geographical isolates of G. fusca, no obvious geographical distribution pattern of G. fusca is found.

[New strategies for the treatment of carcinoma of unknown primary]

Carcinoma of unknown primary (CUP) is a kind of metastatic tumor whose primary origin cannot be identified after adequate examination and evaluation. The main treatment modality of CUP is empiric chemotherapy, and the median overall survival time is less than 1 year. Compared with immunohistochemistry, novel method based on gene expression profiling have improved the sensitivity and specificity of CUP detection, but its guiding value for treatment is still controversial. The approval of immune checkpoint inhibitors and pan-cancer antitumor agents has improved the prognosis of patients with CUP, and targeted therapy and immunotherapy based on specific molecular characteristics are the main directions of future research. Given the high heterogeneity and unique clinicopathological characteristics of CUP, "basket trial" is more suitable for clinical trial design in CUP.

Association between acrylamide exposure and sex hormones among premenopausal and postmenopausal women: NHANES, 2013-2016

PURPOSE

Acrylamide (AA) is a potential carcinogen that mainly comes from fried, baked and roasted foods, and Hb adducts of AA (HbAA) and its metabolite glycidamide (HbGA) are the biomarkers of its exposure. Increasing evidence suggests that AA is associated with various hormone-related cancers. This study aims to explore the association of HbAA and HbGA with female serum sex hormone concentrations.

METHODS

942 women from the National Health and Nutrition Examination Survey cycles (2013-2016) were included in this cross-sectional study. The associations between HbAA or HbGA or HbGA/HbAA and sex hormones were assessed by the multiple linear regression. Further stratified analyses were conducted to figure out the effects of menopausal status, BMI and smoking status on sex hormone levels.

RESULTS

Among all participants, 597 were premenopausal and 345 were postmenopausal. HbAA was positively associated with both two androgen indicators. Specifically, a ln-unit increase in HbAA was associated with 0.41 ng/dL higher ln(total testosterone, TT) (95% CI 0.00, 0.27) and 0.14 ng/dL higher ln(free testosterone) (95%CI 0.00, 0.28), respectively. However, HbGA concentrations had no association with sex hormones in the overall population. Additionally, HbGA/HbAA was negatively associated with TT and SHBG in the overall population as well as postmenopausal women. In stratified analysis, higher HbAA was associated with rising TT in postmenopausal women (β = 0.29, 95%CI 0.04, 0.53) and underweight/normal-weight women (β = 0.18, 95%CI 0.03, 0.33). Other indicators had no significant association detected in estradiol and sex hormone-binding globulin.

CONCLUSION

Our results revealed that HbAA was positively associated with androgen concentrations, especially in postmenopausal and BMI < 25 women.

Hydrogen sulfide protects against ischemic heart failure by inhibiting RIP1/RIP3/MLKL-mediated necroptosis

The aim of the present study was to explore whether hydrogen sulfide (H2S) protects against ischemic heart failure (HF) by inhibiting the necroptosis pathway. Mice were randomized into Sham, myocardial infarction (MI), MI + propargylglycine (PAG) and MI + sodium hydrosulfide (NaHS) group, respectively. The MI model was induced by ligating the left anterior descending coronary artery. PAG was intraperitoneally administered at a dose of 50 mg/kg/day for 4 weeks, and NaHS at a dose of 4mg/kg/day for the same period. At 4 weeks after MI, the following were observed: A significant decrease in the cardiac function, as evidenced by a decline in ejection fraction (EF) and fractional shortening (FS); an increase in plasma myocardial injury markers, such as creatine kinase-MB (CK-MB) and cardiac troponin I (cTNI); an increase in myocardial collagen content in the heart tissues; and a decrease of H2S level in plasma and heart tissues. Furthermore, the expression levels of necroptosis-related markers such as receptor interacting protein kinase 1 (RIP1), RIP3 and mixed lineage kinase domain-like protein (MLKL) were upregulated after MI. NaHS treatment increased H2S levels in plasma and heart tissues, preserving the cardiac function by increasing EF and FS, decreasing plasma CK-MB and cTNI and reducing collagen content. Additionally, NaHS treatment significantly downregulated the RIP1/RIP3/MLKL pathway. While, PAG treatment aggravated cardiac function by activated the RIP1/RIP3/MLKL pathway. Overall, the present study concluded that H2S protected against ischemic HF by inhibiting RIP1/RIP3/MLKL-mediated necroptosis which could be a potential target treatment for ischemic HF.

[Relationship between dynamic changes of psychological distress and quality of life in Chinese early breast cancer patients]

Objective: To explore the dynamic changes of Distress Thermometer scores and the relationship between psychological distress and quality of life in Chinese early breast cancer patients during chemotherapy. Methods: This prospective study enrolled 110 Chinese postoperative early breast cancer patients between March 2019 and December 2019. The psychological distress and quality of life (QOL) of patients were assessed by using the psychological distress management screening tool and the patient quality of life scale. Logistic regression model was used to analyze the influencing factors of psychological distress degree. The correlation between distress thermometer (DT) score changes and quality of life was analyzed by Pearson correlation analysis. Results: In total, 96 valid cases were analyzed. Before chemotherapy, 47 cases (49.0%) had DT score ≥4 points. After 2 cycles of chemotherapy, 40 cases (41.7%) had DT score ≥4 points. Thirty-four patients (35.4%) had DT score ≥4 points after chemotherapy. The DT score after chemotherapy was lower than that before chemotherapy and after 2 cycles of chemotherapy. Univariate analysis showed that income level and pathological stage were still significant related to the detection of DT score ≥4 points after chemotherapy (P<0.05). The changes of DT scores before and after chemotherapy were negatively correlated with the changes of quality of life ( r=-0.298, P=0.003). Conclusions: The detection rate of psychological distress in patients with early breast cancer during chemotherapy showed a decreasing trend. Income level and tumor stage are significant factors affecting the psychological distress of patients. There is a significant correlation between the psychological distress and the quality of life during chemotherapy. We should pay attention to the evaluation and monitoring state of psychological distress of patients during chemotherapy.

[Safety and feasibility of stereotactic radiation therapy on porcine ventricular septum: a preliminary study]

Objective: To explore the safety and feasibility of stereotactic radiation therapy (SBRT) strategy for irradiating porcine ventricular septum, see if can provide a preliminary experimental evidence for clinical SBRT in patients with hypertrophic obstructive cardiomyopathy (HOCM). Methods: Five male pigs (39-49 kg, 6 months old) were used in this study. Pigs were irradiated at doses of 25 Gy (n=2) or 40 Gy (n=3). Delineation of the target volume was achieved under the guidance of 3-dimensional CT image reconstruction, and SBRT was then performed on defined target volume of porcine ventricular septum. Blood biomarkers, electrocardiogram and echocardiography parameters were monitored before and after SBRT. Pathological examination (HE staining, Masson staining) was performed on the target and non-target myocardium at 6 months post SBRT. Results: SBRT was successful and all animals survived to the designed study endpoint (6 months) after SBRT. Serum cardiac troponin T (cTnT) level was significantly higher than the baseline level at 1 day post SBRT, and reduced at 1 week after SBRT, but was still higher than the baseline level(P<0.05). Serum N-terminal pro-B type natriuretic peptide (NT-proBNP) was also significantly increased at 1 day post SBRT (P<0.05) and returned to baseline level at 1 week post SBRT. The serum NT-proBNP level was (249±78), (594±37) and (234±46) pg/ml, respectively, and the cTnT was (14±7), (240±40) and (46±34) pg/ml, respectively at baseline, 1 day and 1 week after SBRT in the 40 Gy dose group. The serum NT-proBNP level was (184±20), (451±49) and (209±36) pg/ml, respectively, the cTnT values ​​were (9±1), (176±29) and (89±27) pg/ml, respectively at baseline, 1 day and 1 week after SBRT in the 25 Gy dose group. Both NT-proBNP and cTnT values tended to be higher post SBRT in the 40 Gy dose group as compared with the 25 Gy dose group, but the difference was not statistically significant (P>0.05). The left ventricular ejection fraction and the left ventricular end-diastolic diameter remained unchanged before and after SBRT (P>0.05). The interventricular septum thickness showed a decreasing trend at 6 months after SBRT, but the difference was not statistically significant ((9.54±0.24) mm vs. (9.82±8.00) mm, P>0.05). The flow velocity of the left ventricular outflow tract, and the valve function and morphology were not affected by SBRT. At 6 months after SBRT, HE staining revealed necrosis in the irradiated target area of ​​the myocardium in the 40 Gy dose group and the 25 Gy dose group, and the degree of necrosis in the irradiated interventricular septum was more obvious in the 40 Gy dose group as compared with the 25 Gy group. The combined histological analysis of the two groups showed that the necrotic area of ​​the irradiated target area accounted for (26±9)% of the entire interventricular septum area, which was higher than that of the non-irradiated area (0) (P<0.05). There was no damage or necrosis of myocardial tissue outside the target irradiation area in both groups. The results of Masson staining showed that the percentage area of myocardial fibrosis was significantly higher in the irradiated target area than non-irradiated area ((12.6±5.3)% vs. (2.5±0.8)%, P<0.05). Conclusion: SBRT is safe and feasible for irradiating porcine ventricular septum.

[A real world study on the relationship between drug resistance of targeted therapy and prognosis of HER-2-positive advanced breast cancer]

Objective: To explore the effect of primary and acquired resistance to anti-human epidermal growth factor receptor 2 (HER-2) on the overall survival of patients with HER-2 positive advanced breast cancer. Methods: The clinical characteristics of HER-2 positive patients with advanced breast cancer admitted to Cancer Hospital of Chinese Academy of Medical Sciences from January 1998 to December 2018 were collected, and their neoadjuvant/adjuvant and advanced three-line chemotherapy were summarized. Among them, targeted drugs for HER-2 included trastuzumab, pertuzumab, T-DM1, RC48-ADC, lapatinib, pyrotinib, allitinib, sipatinib, seratinib. Based on the duration of benefit from anti HER-2 treatment, the patients were divided into two groups: primary anti HER-2 resistance group and acquired anti HER-2 resistance group. In this study, the overall survival (OS) was used as the main end point. Kaplan-Meier analysis and Cox proportional risk regression model were used to analyze the effects of different drug resistance mechanisms on the overall survival. Results: The whole group of 284 patients were included. The median age of recurrence and metastasis was 48 years old, 155 (54.6%) were hormone receptor (HR) positive and 129 (45.4%) were HR negative, 128 cases (45.1%) were premenopausal and 156 cases (54.9%) were postmenopausal, 277 cases (97.5%) had a score of 0-1 in ECoG PS and 7 cases (2.5%) had a score of more than 2 in the first diagnosis of relapse and metastasis. There were 103 cases (36.3%) in the primary drug resistance group and 181 cases (63.7%) in the secondary drug resistance group. The median overall survival time of the two groups was 24.9 months and 40.4 months, respectively, with statistical significance (P<0.001). Conclusion: Primary resistance to HER-2 is one of the factors of poor prognosis in HER-2 positive breast cancer, and its mechanism needs to be further explored.

Radiofrequency Ablation of the Superior Cluneal Nerve: A Novel Minimally Invasive Approach Adopting Recent Anatomic and Neurosurgical Data

Objectives/Introduction

Superior cluneal neuralgia (SCN) is a distinct cause of lower back and/or leg pain related to pathology of the superior cluneal nerve (SCn). SCN has been termed pseudo-sciatica and is an overlooked differential diagnosis when patients are otherwise presenting with low back and/or radicular pain. Radiofrequency ablation (RFA) is commonly used for denervation of the medial branches of the dorsal root for facet joint syndrome for sacroiliac joint; however, RFA has not been described to ablate the SCn for SCN. Herein, we present a novel interventional minimally invasive approach using RFA of the SCn for SCN in a series of 46 patients.

Methods

Institutional review board approved retrospective chart review was used to collect data for all SCn RFA cases from January 1, 2018, to February 8, 2021. Fluoroscopically guided SCn ablations were performed for patients with a positive “iliac crest point sign,” reproductive of their back and leg pain during physical examination. Sensory stimulation was utilized to confirm RF cannula-probe placement adjacent to the SCn, and motor testing was used to confirm no distal motor response prior to monopolar RF ablation with a Halyard RF Generator (100 mm curved 22G 10 mm active tip RF cannulae). Charts were reviewed for time of analgesia follow-up, duration and degree of analgesia, improvements in patients’ functional capacity, and changes in medication.

Results

Data were reviewed for 51 patients who underwent Scn RFA, 5 of which were lost to follow-up. The remaining 46 patients consisted of 29 women and 17 men with a mean age of 59.4 years; 78.3% (n = 36) had ongoing relief at a mean of 92.1 days follow-up, ranging from 13 to 308 days, with a mean of 92.3% analgesia (SD 15.0%). At a mean of 111.2 days of follow-up, ranging from 42–201 days, 21.7% (n = 10) of patients reported that their pain had returned and had 95% analgesia during that time period (SD 6.7%); 41.3% (n = 19) reported improved activity/gait, 17.4% reported improved mood (n = 8), and 8.7% reported decreased medication use (n = 4). Five patients had minor complications including bruising (1), 2–3 days of soreness on site (2), myofascial pain (1), and quadratus lumborus muscle spasm relieved with trigger point injection (1).

Conclusions

This is the first report of both technique and outcomes for radiofrequency ablation of superior cluneal neuralgia. This series suggests that RFA of the SCn is a suitable intervention for the treatment of SCN; 21.7% of patients reported a mean of 95% analgesia for a mean duration of 111.2 days, and the remaining 78.3% of patients reported ongoing relief with a mean of 92.3% analgesia at last follow-up (mean 92.1 days). There were no serious adverse events.

[Efficacy and survival outcomes of dose-dense carboplatin plus paclitaxel as neoadjuvant chemotherapy for triple-negative breast cancer]

Objective: To evaluate the efficacy and survival outcomes of dose-dense (biweekly) carboplatin plus paclitaxel (PC) as neoadjuvant chemotherapy (NAC) in triple-negative breast cancer (TNBC), and to explore an optimal neoadjuvant chemotherapy regimen for TNBC. Methods: Patients diagnosed as TNBC(cT1-4N0-3M0) in Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College Between January 2008 and September 2018 who received dose-dense PC and standard 3-weekly PC as NAC were 1∶1 matched using propensity score matching (PSM) to compare the efficacy, safety and survival outcomes. Results: One hundred of TNBC patients were enrolled (50 patients were divided in dose-dense group, 50 patients in standard group). The objective response rate (ORR) of dose-dense group and standard group were both 90.0% (45/50). The grade 3-4 neutropenia in dose-dense group was less than that of standard group (32.7% vs. 68.0%, P=0.001), while the rate of ALT/AST elevation in dose-dense group was higher than that of standard group (57.1% vs. 32.0%, P=0.012). The pathological complete response (pCR) rates were 34.0% (17/50) in dose-dense group and 38.0% (19/50) in standard group, without statistically significance (P=0.677). The median follow-up time was 55 months (3-150 months). The 5-year recurrence-free survival (RFS) in dose-dense group and standard group were 83.5% and 75.2%, respectively the 5-year overall survival (OS) in dose-dense and standard group were 87.9% and 84.5% the difference were not statistically significant (P=0.322 and 0.647, respectively). Patients with residual disease (tumor size≥1 cm or lymph node positive) had poor prognosis, the 5-year RFS and OS were 59.3% and 68.5%, respectively. Conclusions: Dose-dense PC has similar efficacy with standard 3-weekly PC and has a good safety profile. Since dose-dense regimen can shorten the duration of therapy, it can be an alternative in TNBC.

Extensive hearing loss induced by low‐frequency noise exposure

Background

With little attention given to low‐frequency traffic noise and our understanding that cochlear function may be highly susceptible to low‐frequency noise, there is an urgent need to determine traffic noise‐induced hearing loss (NIHL), not only the hearing loss at low frequency but also the possible high‐frequency hearing loss.

Methods

The current study aims to investigate the potential for extensive hearing loss induced by exposure to 0.063 kHz octave band noise (OBN), which is an important component of low‐frequency traffic noise. The threshold of auditory brainstem response (ABR) was used to evaluate hearing function before and after noise exposure. Chinchillas were randomly assigned into seven different groups. Group 63‐3 h/6 h, Group 2 k‐3 h/6 h, and group 4 k‐3 h/6 h were exposed for either 3 or 6 h to 0.063, 2, and 4 kHz OBN at 90 dB SPL, respectively. The control group was not exposed to noise.

Results

Significant ABR threshold‐shifts (TS) were observed at 0.88, 2, 4, and 5.7 kHz in Group 63‐6 h, and at 2.8 and 4 kHz in Group 2 k‐6 h, and at 5.7 kHz in Group 4 k‐6 h. ABR‐TS were consistent with outer hair cell (OHC) losses, exposure to 0.063 kHz OBN at 90 dB SPL for 6 h induced large‐scale losses of OHC both in low‐ and high‐frequency region.

Conclusions

Exposure to 0.063 kHz low‐frequency OBN at 90 dB SPL for 6 h leads to significant hearing loss over an extensive range from low to high frequencies.

Fully automated segmentation in temporal bone CT with neural network: a preliminary assessment study

BACKGROUND

Segmentation of important structures in temporal bone CT is the basis of image-guided otologic surgery. Manual segmentation of temporal bone CT is time- consuming and laborious. We assessed the feasibility and generalization ability of a proposed deep learning model for automated segmentation of critical structures in temporal bone CT scans.

METHODS

Thirty-nine temporal bone CT volumes including 58 ears were divided into normal (n = 20) and abnormal groups (n = 38). Ossicular chain disruption (n = 10), facial nerve covering vestibular window (n = 10), and Mondini dysplasia (n = 18) were included in abnormal group. All facial nerves, auditory ossicles, and labyrinths of the normal group were manually segmented. For the abnormal group, aberrant structures were manually segmented. Temporal bone CT data were imported into the network in unmarked form. The Dice coefficient (DC) and average symmetric surface distance (ASSD) were used to evaluate the accuracy of automatic segmentation.

RESULTS

In the normal group, the mean values of DC and ASSD were respectively 0.703, and 0.250 mm for the facial nerve; 0.910, and 0.081 mm for the labyrinth; and 0.855, and 0.107 mm for the ossicles. In the abnormal group, the mean values of DC and ASSD were respectively 0.506, and 1.049 mm for the malformed facial nerve; 0.775, and 0.298 mm for the deformed labyrinth; and 0.698, and 1.385 mm for the aberrant ossicles.

CONCLUSIONS

The proposed model has good generalization ability, which highlights the promise of this approach for otologist education, disease diagnosis, and preoperative planning for image-guided otology surgery.

[Analysis of the effect of ipsilateral supraclavicular lymph node metastasis on the prognosis of N3 breast cancer]

Objective: The 6th edition American Joint Committee on Cancer (AJCC) staging system for breast cancer classifies ipsilateral supraclavicular lymph node metastasis (ISLM) downing stage from M1 to N3, suggesting more patients might receive radical treatment. The aim of this study was to analyze the effect of ISLM on the prognosis of N3 breast cancer and verify the rationality of modified staging. Methods: A total of 321 breast cancer patients with N3 according to the 6th edition AJCC staging system were retrospectively analyzed. Propensity Score Matching (PSM) was used to pair the different subgroups of N3. The primary end point was disease-free survival (DFS), the secondary end point was overall survival (OS). Kaplan-Meier method was used to calculate the DFS and OS. The differences between two groups were analyzed by the Log-rank test. Results: After PSM pairing twice, 78 patients with none-ISLM and 78 patients with ISLM were enrolled in the first group; 51 patients with none-ISLM was compared patients with isolated ISLM in the second group. The results of the two groups showed that patients with none-ISLM have a prolonged DFS (the first group: 58.9 months vs 32.1 months, P=0.101; the second group: 59.0 months vs 44.0 months, P=0.533), while the OS was opposite (the first group: 87.4 months vs 140.4 months, P=0.289; the second group: 87.4 months vs 137.1 months, P=0.289). Conclusions: The prognosis of breast cancer patients with ISLM is similar to that of patients with none-ISLM in stage N3. It is reasonable to include ISLM in N3 in the 6th edition AJCC staging system. Yet, prospective studies with larger sample size are needed to further confirmation.

[Peripheral blood EMR3 gene methylation level is correlated with breast cancer in Chinese women]

OBJECTIVE

To explore the association of methylation levels of C19orf57, MAP9, EMR3, NEK6 and PCOLCE2 genes in peripheral blood with breast cancer (BC) in Chinese women.

METHODS

We collected peripheral blood samples from 258 early-stage BC patients and 272 healthy women. Agena matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was utilized to quantitatively measure the methylation levels of CpG sites in the genes. The association between DNA methylation and BC was analyzed using a logistic regression model adjusted for covariants. Spearman's correlation analysis was performed to analyze the association between the gene methylation levels and age. The methylation levels of the genes in the BC patients with different clinical characteristics were investigated using non-parametric tests.

RESULTS

In stead of EMR3 gene hypermethylation as found in BC patients as found in the Caucasian population, EMR3 gene hypomethylation was found to correlate with BC in Chinese women, but this correlation was significant only in women beyond the age of 50 years (for every 10% reduction of the methylation level, EMR3_CpG_1: OR=1.40; EMR3_CpG_2: OR=2.31; EMR3_CpG_3: OR=2.76, P < 0.05). EMR3 methylation was not or was only weakly correlated with tumor stage, size, lymphatic metastasis, ER, PR, HER2, or Ki67. Our data did not show a correlation between C19orf57 methylation and BC.

CONCLUSION

Peripheral blood EMR3 gene hypomethylation is associated with BC in Chinese women, especially in those at an old age and in postmenopausal women.

A Bayesian network meta-analysis of comparison of cancer therapeutic vaccines for melanoma

Several approaches to active immunotherapy for melanoma, including peptide-based vaccines (PVs), autologous tumour cell vaccines (TCVs), allogeneic TCVs and autologous dendritic cell vaccines (DCVs), have been investigated in clinical trials. However, comprehensive evidence comparing these interventions remains unavailable. The objective of this study was to expand previous work to compare and rank the immunotherapeutic strategies for melanoma in terms of overall survival and toxic effects with a Bayesian network meta-analysis. Methodologically, we performed a network meta-analysis of head-to-head randomized controlled trials comparing and ranking cancer vaccine approaches for patients with melanoma. PubMed, MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, the WHO International Clinical Trials Registry Platform and ClinicalTrials.gov were searched up to 31 July 2020. We estimated summary hazard ratios for death and risk ratios for toxicity. The effects of the underlying prognostic variable on survival benefits were examined by meta-regression. We performed subgroup analysis for the outcomes based on metastatic categories. Overall, we identified 4776 citations, of which 15 head-to-head randomized controlled trials (3162 participants) were included in the analysis. In terms of efficacy, allogeneic tumour cell vaccines plus immunotherapy adjuvants, peptide-based vaccines plus immunotherapy adjuvants and standard therapy were more effective than peptide vaccines. The proportion of women was inversely associated with mortality risk. For safety, all treatments were inferior to allogeneic tumour cell vaccines except for allogeneic tumour cell vaccines plus chemotherapy. Peptide vaccines plus immunotherapy adjuvants led to an increased risk of adverse events compared to allogeneic tumour cell vaccines plus immunotherapy adjuvants. These results suggest that allogeneic TCV and autologous DCV are better than standard therapy. PV plus immune modulators are the most effective strategy among all comparable strategies but is associated with increased toxicity. Any combination regimens for cancer therapeutic vaccines need to be balanced between risk and benefit profiles.

Prevalence of mcr-1 in Colonized Inpatients, China, 2011-2019

In response to the spread of colistin resistance gene mcr-1, China banned the use of colistin in livestock fodders. We used a time-series analysis of inpatient colonization data from 2011-2019 to accurately reveal the associated fluctuations of mcr-1 that occurred in inpatients in response to the ban.

[Exploration of the high-risk factors of catheter-related thrombosis in breast cancer]

Objective: To explore the high risk factors of catheter-related thrombosis (CRT) in breast cancer patients, and provide the basis for the development of appropriate prevention and treatment strategies. Methods: A total of 1 432 breast cancer patients scheduled to receive central venous catheterization in National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College from January 1, 2015 to August 31, 2019 were selected. Baseline information and catheterization information of patients were collected. The occurrence of CRT was confirmed by vascular ultrasound examination, and the influencing factors of CRT were analyzed. Results: The total number of catheter days were 121, 980 days in 1 432 patients with breast cancer, and the average number of catheter days in each patient was 85.2 days. The incidence of CRT was 6.8% (97/1 432), which was 0.79 cases/1 000 catheter days. Among 815 patients with centrally inserted central venous catheters (CICC), 43 (5.3%) had CRT, which was 0.70 cases/1 000 catheter days. Among 617 patients with peripherally inserted central venous catheters (PICC), 54 (8.8%) developed CRT, which was 0.90 cases/1 000 catheter days. CRT was most common in subclavian vein (63.9%). Multivariate regression analysis showed that age ≥ 60 years old (OR=1.712, 95% CI: 1.056-2.775, P=0.029), PICC (OR=1.732, 95% CI: 1.130-2.656, P=0.012), the catheter position except subclavian vein (OR=10.420, 95% CI: 1.207-89.991), secondary adjustment of catheter position (OR=3.985, 95% CI: 1.510-10.521, P=0.005) and high D-Dimer level (OR=1.129, 95% CI: 1.026-1.241, P=0.012)were independent risk factors for CRT. Conclusions: The CRT problem can't be ignored in the clinical treatment of breast cancer patients with central venous catheterization. Screening the appropriate age of patients and the type of central venous catheters, reducing the secondary adjustment of catheter position, and timely monitoring the level of D-dimer are helpful to the prevention and treatment of CRT.

Time resolved absolute extreme ultraviolet radiation measurement on the ENN XuanLong-50 spherical tokamak

A plasma radiation measurement system for a wide spectral range, based on compact Absolute eXtreme UltraViolet (AXUV) silicon photodiodes, has been implemented on the newly constructed ENN XuanLong-50 (EXL-50) spherical tokamak. The system consists of two 16-channel AXUV16ELG arrays and one AXUV63HS1 single-cell detector mounted on ceramic sockets. The two arrays, facing toward the EXL-50 slim central post from two locations inside a top and a side ConFlat 400 port, have 32 view chords covering the interested plasma region in a poloidal cross section at toroidal 330°. The single-cell detector, seated on a retractable feedthrough, could be arranged flexibly with the help of an ultra-high vacuum compatible gate valve. The design details together with considerations on the EXL-50 specific engineering realities and physics requirements are described. Preliminary results from the EXL-50 2020 experimental campaign are presented.

[Causes analysis of mastoid cavity infection after mastoidectomy and key techniques of revision mastoidectomy]

Objective:To analyze the causes of infected mastoid cavity after mastoidectomy and explore the key techniques of revision mastoidectomy. Methods:Ninety-two patients, who underwent revision mastoidectomy due to mastoid cavity infection after mastoidectomy were retrospectively analyzed. There were 56 cases of canal wall up mastoidectomy plus tympanoplasty and 36 cases of canal wall down mastoidectomy plus tympanoplasty in previous surgery. The interval between the previous operation and this revision ranged from 7 months to 50 years, with a median of 9 years. By reviewing the general clinical data, preoperative HRCT scan of temporal bone and intraoperative findings, the defects of the previous operation and the region of the lesion were analyzed and counted. Results:Out of the 92 cases, 7 cases（7.6%） had sigmoid sinus antedisplacement and low-lying middle cranial fossa, and 45 cases（48.9%） with facial nerve canal loss. Among the 36 patients who underwent canal wall down mastoidectomy and tympanoplasty, mastoid cells were removed in completely; 26 patients had high facial ridge, accounting for 72.2%（26/36）. The defects of the previous operation included: stenosis of external auditory meatus（65/92, 70.7%）, obstruction of Eustachian tube（11/92, 12.0%）, and tympanitis（2/92, 2.2%）. Residual or recurrent lesions were most common in mastoid process and tympanic sinus（50/92, 54.3%）, followed by attic cell and anterior cavity（44/92, 47.8%）, posterior tympanic cavity（29/92, 31.5%）, perilabyrinthine cells（13/92, 14.1%）, sinus meningeal angle（13/92, 14.1%）, cells behind the facial nerve（12/92, 13.0%）, Eustachian tube（10/92, 10.9%）, and hypotympanum（9/92, 9.8%）. Conclusion:The main causes of mastoid cavity infecion after mastoidectomy include incomplete removal of the lesion and inadequate drainage conditions. The key techniques of revisional mastoidectomy include disc-shaped operative cavity, skeletonization of mastoid process, reduction of facial nerve ridge, management of Eustachian tube and conchaplasty. The above techniques are also key in the first operation in order to improve the success rate of operation and avoid revision operation.

Lactobacillus strains derived from human gut ameliorate metabolic disorders via modulation of gut microbiota composition and short-chain fatty acids metabolism

Regulation on gut microbiota and short-chain fatty acids (SCFAs) are believed to be a pathway to suppress the development of metabolic syndrome. In this study, three Lactobacillus strains derived from the human gut were investigated for their effects on alleviation of metabolic disorders. These strains were individually administered to metabolic disorder rats induced by high-fat-high-sucrose (HFHS) diet. Each strain exhibited its own characteristics in attenuating the impaired glucose-insulin homeostasis, hepatic oxidative damage and steatosis. Correlation analysis between SCFAs and host metabolic parameters suggested that Lactobacillus protective effects on metabolic disorders are partly mediated by recovery of SCFAs production, especially the faecal acetic acid. Correspondingly, it indicated that probiotics restore the gut microbiota dysbiosis in different extent, thereby protect against metabolic disorders in a manner that is associated with microbiota, but not totally reverse the changed composition of microbiota to the normal state. Thus, Lactobacillus strains partly protect against diet-induced metabolic syndrome by microbiota modulation and acetate elevation.

[Quality of life assessment after endoscopic and microscopic myringoplasty using Chinese version of the Zurich chronic middle ear inventory]

Objective:To assess and compare therapeutic effects and quality of life after endoscopic and microscopic myringoplasty using Chinese version of the Zurich chronic middle ear inventory（ZCMEI）. Methods:Patients with chronic suppurative otitis media underwent myringoplasty at the Third Hospital of Peking University from October 2018 to September 2019 were included in this study and divided into two groups: endoscopic tympanoplasty group（n=40） and microscopic tympanoplasty group（n=57）. ZCMEI survey and pure tone audiometry were conducted preoperatively and 3-9 months postoperatively. The operation time, intraoperative blood loss, length of hospital, graft success rate, complication rate, hearing improvement and quality of life improvement were compared. Results:①The operation time, length of hospital and intraoperative blood loss of endoscopic group were significantly lower（P<0.05）. ②The graft success rate was 92.5% and 98.2%, respectively（P>0.05）. The difference between the complication rate in two groups was not significant, but patients in endoscopic group had no symptoms of wound numbness or pain. ③Air conduction threshold（AC） and air-bone gap（ABG） were significantly lower after surgery in endoscopic group（n=33） and microscopic group（n=43）. The analyzed result of generalized linear model indicated surgical approach had no influence on postoperative AC and ABG（P>0.05）. ④The total scores of ZCMEI were significantly improved in endoscopic group（n=32） and microscopic group（n=48） postoperatively, as well as the scores of ear symptoms, hearing and psychosocial impact（P<0.05）. Preoperative and postoperative scores of medical resources were not significantly different in either groups（P>0.05）. Controlling the course of disease, the total ZCMEI results and scores of each subscale in patients with single ear involved（n=71） had no significant difference between two groups. Conclusion:Endoscopic myringoplasty has the advantages of minimal invasiveness, short operation time, and quick recovery evaluated from subjective and objective aspects. Audiometry improvement, graft success rate, complication rate and quality of life improvements are comparable between endoscopic tympanoplasty and conventional microscopic tympanoplasty. The assessment of the quality of life is of great significance in efficacy evaluation of otitis media. Doctors should comprehensively consider patient's subjective experience and the objective improvement to obtain the best clinical efficacy.

Prevalence, genomic characteristics, and transmission dynamics of mcr-1-positive Salmonella enterica Typhimurium from patients with infectious diarrhea

BACKGROUND

Previous studies reported the prevalence of mcr-1 among clinical infected Salmonella isolates in China. However, the transmission dynamics of mcr-1 in different ecological niches were not well investigated. Our objective is to exhibit the transmission dynamics of mcr-1 in Salmonella.

METHODS

598 Salmonella isolates were recovered from ten hospitals; besides 936 pig faces and 167 pork samples were collected from January 2015 to December 2017 in Guangzhou, China. PCR and sequencing were used to identify mcr-1-positive Salmonella. Antimicrobial susceptibility testing was performed with 16 antimicrobials. Conjugation, S1-PFGE, and Southern blot were used to determine the transferability and location of mcr-1. Whole-genome sequencing was used to investigate pangenome, phylogeny, plasmid, and transposon.

RESULTS

Eleven mcr-1-positive Salmonella isolates were identified from patients with infectious diarrhea. Five pig fecal samples and three pork samples contained mcr-1-positive Salmonella isolates. All isolates were multi-drug resistant. The mcr-1 genes were located on ∼210-250 kb IncHI2-pST3 plasmids, and 12 mcr-1 genes were transferable. All isolates were assigned to ST34 or its genetically closed STs. The distribution of the core-genome network was significantly correlated with source distributions. The accessory genes-based network demonstrated that the diverse clonal complexes could share highly similar accessory genomes.

CONCLUSIONS

The prevalence of mcr-1-positive Salmonella among different sources was low. Clonal transmission could not be the main reason for the expansion of mcr-1-positive Salmonella, but be attributed to the horizontal transfer of IncHI2-pST3 plasmid. Continuous surveillance on Salmonella should be performed to investigate the response of colistin banning in food-producing animals by mcr-1-positive Salmonella populations.

Responses of Phragmites australis to copper stress: A combined analysis of plant morphology, physiology and proteomics

Few relevant research attempts have been made to determine heavy metal resistance mechanisms of rhizomatous perennial plants. Thus, it is pertinent to investigate the physiological and biochemical changes in Phragmites australis under metal-stressed conditions to facilitate the development of strategies to enhance copper (Cu) tolerance. We measured parameters related to plant growth and development, metal translocation and physiological responses of P. australis subjected to Cu stress. In addition, the differentially expressed proteins (DEP) were evaluated using the isobaric tag for relative and absolute quantification (iTRAQ) system. A large amount of copper accumulates in the roots of P.australis, but the growth parameters were not sensitive to Cu. However, the high concentration of Cu reduced the content of chlorophyll a and chlorophyll b, and the expression of important photosynthesis proteins PsbD, PsbO and PsaA were all down-regulated, so photosynthesis was inhibited. In contrast, the content of ascorbic acid and proline both increased with the increase of copper stress. P.australis fixed a large amount of Cu in its roots, limiting the migration of Cu to other parts of the plant. Moreover, Cu stress can affect photosynthesis by inhibiting the activity of PSI, PSII and LHCII. In addition, P.australis synthesizes ascorbic acid through the D-mannose/L-galactose pathway, and synthesizes proline through the ornithine pathway. Ascorbic acid and proline can increase Cu tolerance and protect photosynthesis. These results provide a theoretical basis for understanding the tolerance and repair mechanisms of plants in response to heavy metal pollution.

[Clinical analysis of 21 cases of cholesteatoma recidivism after canal-wall-up mastoidectomy with tympanoplasty]

Objective:To discuss the possible reasons for cholesteatoma recidivism after canal-wall-up mastoidectomy with tympanoplasty by analyzing clinical characteristics of patients. Methods:Data of 21 cases who suffered from cholesteatoma recidivism after canal-wall-up surgery were retrospectively reviewed, including preoperative examination, high resolution temporal bone CT, and intraoperative findings. Results:90.5%（19/21） cases had recurrent cholesteatoma with retraction pockets. Among 12 cases with previous operative notes, 66.7%（8/12） had extensive cholesteatoma which was not limited to attic in the original surgery. The intraoperative features of revision surgery in 21 patients including the destruction of reconstructive lateral attic wall and scutumwere found in 19.0%（4/21） cases, the head of malleus left in 19.0%（4/21） cases, the cholesteatoma found in hidden part in 14.3%（3/21） cases, the hadeustachian tube dysfunction in 38.1%（8/21）cases. the sclerotic mastoid in 42.9%（9/21） cases. hadanatomic variations of the temporal bone in 14.3%（3/21） cases and atresia of external auditory canal in 4.8%（1/21） cases. Conclusion:In this group of recidivism cases, most patients had extensive cholesteatoma, which may lead to excessive mucosa loss during lesion clearance, poor ventilation of tympanic isthmus after surgery, and promote the formation of retraction pocket. In addition, some cases had eustachian tube dysfunction, unstable reconstruction of attic lateral wall, and improper selection of the indications, which may also increase the risk of recurrence. Therefore, in order to reduce cholesteatoma recidivism after canal-wall-up surgery, attention should be paid to the striction of surgical indications, comprehensive preoperative evaluation, thorough clearance of lesions and firm reconstruction.

Label-Free Resistance Cytometry at the Orifice of a Nanopipette

Development of new principles and techniques at the single-cell level is significantly important since cells as basic units of living organisms always bear large heterogeneity. Herein, we demonstrate a new electrochemical principle for single-cell analysis based on an ion current blockage at the orifice of a nanopipette, defined as resistance cytometry. The amplitude and the frequency of ion current transients show strong dependence on the size and the concentration of cells, which could be used for in situ cell sizing and counting. This technique shows good ability to detect the size change of RBCs under stimulations of different pH and osmotic pressure values. More importantly, the as-presented resistance cytometry can distinguish lymphoma blood cells from normal blood cells for patient blood samples. The as-presented resistance cytometry is label-free, non-invasive, and non-destructive, which not only opens new opportunities for single-cell analysis but also provides a new platform for cell-related medical diagnostic technologies.

[Clinical research progress of T-DM1 in breast cancer]

Ado-trastuzumab emtansine (T-DM1) is an antibody-drug conjugate (ADC) composed of trastuzumab, a linker, and a microtubule inhibitor. T-DM1 combines the highly effective targeting of antibody with the high anti-tumor activity of cytotoxic drugs, while reduces the off-target toxic side effects of cytotoxic drugs. T-DM1 has been applied in neoadjuvant therapy of HER2-positive breast cancer and rescue treatment of advanced breast cancer, greatly improves the prognosis of breast cancer patients. More and more clinical trials of T-DM1 for HER2 breast cancer and other solid tumors are ongoing, and more positive results are expected.

[Efficacy and safety of neoadjuvant apatinib in combination with dose-dense paclitaxel and carboplatin in locally advanced triple negative breast cancer patients]

Objective: To observe the short-term efficacy and safety of apatinib in combination with dose-dense paclitaxel and carboplatin in locally advanced triple-negative breast cancer (TNBC) patients. Methods: From September 2018 to September 2019, 17 stage Ⅱ/Ⅲ TNBC patients were enrolled in this single arm, single center prospective phase Ⅱ study. They received neoadjuvant treatment of apatinib 250 mg per day, paclitaxel 175 mg/m(2) on 1(st) day and a dose of carboplatin according to the area under curve (AUC)=4 on 2(nd) day, every 14 days as a cycle. Results: By January 2020, 16 cases completed 4-7 cycles of apatinib treatment and 4-8 cycles of chemotherapy. The median cycles of apatinib treatment and chemotherapy were 5 cycles and 6 cycles, respectively. Two cases achieved complete responses (CR), 12 achieved partial responses (PR), 2 achieved stable diseases (SD) and no progressive disease was observed. The objective response rate (ORR) was 87.5%, disease control rate (DCR) was 100%. By January 2020, among 12 patients who received surgery, 8 achieved pathologic complete response (pCR, 66.7%). The grade Ⅲ/Ⅳ adverse events included: neutropenia, thrombocytopenia in 3 cases (18.8%) each, anemia, fatigue, arrhythmia and alanine aminotransferase (ALT) elevation in 1 case each. Apatinib was interrupted in 5 cases, and was discontinued in 3 cases; chemotherapy dosage was reduced in 1 case. Conclusion: Apatinib in combination with dose-dense paclitaxel and carboplatin neoadjuvant therapy are effective and well tolerated in locally advanced TNBC patients.

Effects of Folic Acid and Vitamin B12 Supplementation on Cognitive Impairment and Inflammation in Patients with Alzheimer's Disease: A Randomized, Single-Blinded, Placebo-Controlled Trial

OBJECTIVES

To evaluate the combined action of folic acid and vitamin B12 supplementation on cognitive performance and inflammation in patients with Alzheimer's disease (AD).

DESIGN

This was a randomized, single-blind, placebo-controlled trial.

PARTICIPANTS

Patients (n=120) diagnosed clinically as probable AD and in stable condition from Tianjin Key Laboratory of Cerebrovascular and Neurodegenerative Diseases.

MEASUREMENTS

Individuals were randomly divided into the intervention group (n=60, folic acid 1.2 mg/d + vitamin B12 50 μg/d) and the placebo group (n=60). Cognitive performance, blood folate, vitamin B12, one carbon cycle metabolite, and inflammatory cytokine levels were measured at baseline and after 6 months. The data were analyzed using linear mixed models for repeated measures.

RESULTS

A total of 101 participants (51 in the intervention group and 50 in the placebo group) completed the trial. Folic acid plus vitamin B12 supplementation had a beneficial effect on the MoCA total scores (P=0.029), naming scores (P=0.013), orientation scores (P=0.004), and ADAS-Cog domain score of attention (P=0.008), as compared to those of the control subjects. Moreover, supplementation significantly increased plasma SAM (P<0.001) and SAM/SAH (P<0.001), and significantly decreased the levels of serum Hcy (P<0.001), plasma SAH (P<0.001), and serum TNFα (P<0.001) compared to in the control subjects.

CONCLUSIONS

Folic acid and vitamin B12 supplementation showed a positive therapeutic effect in AD patients who were not on a folic acid-fortified diet. The findings of this study help to delineate nutrient intervention as far as public health management for the prevention of dementia is concerned.