Structural insights into an MsmUdgX mutant capable of both crosslinking and uracil excision capability

UdgX from Mycobacterium smegmatis (MsmUdgX) is a prototypical enzyme representing a new class of uracil-DNA glycosylases (UDG) closely related to the family 4 enzymes. It possesses a unique R-loop rich in positive residues and forms a covalent bond with single-stranded uracil-containing DNAs (ssDNA-Us) that is resistant to denaturants after the removal of the target uracil. We previously identified the H109E mutant of MsmUdgX that forms a weak covalent complex with ssDNA-U and yet possesses moderate uracil excision activity, but the mechanism of its action is not fully understood. To further study the catalytic process of MsmUdgX, we solved the high-resolution crystal structures of H109E in the free and DNA-bound forms, respectively. We found that the key residue Glu109 adopts a similar conformation to that of WT to form the covalent bond, suggesting that it still employs the same "excision-inhibition" mechanism to that of the WT enzyme. The enzyme remains nearly intact before and after the crosslinking reaction, but the first half of the R-loop exhibits large structural differences while the rest of the loop barely moves, owing to the salt-bridge interaction formed via Arg107. Additionally, Arg107, along with Gln53 was found to play important roles in the biochemical properties of MsmUdgX. Our studies provide new insights into the MsmUdgX catalysis and improve our understanding on this unique enzyme.

Microvesicle-containing miRNA-153-3p induces the apoptosis of proximal tubular epithelial cells and participates in renal interstitial fibrosis

OBJECTIVE

To uncover the role of microvesicle-containing (MV-containing) miRNA-153-3p in inducing the apoptosis of proximal tubular epithelial cells and RIF (renal interstitial fibrosis), and its potential mechanism.

MATERIALS AND METHODS

Mice were subjected to unilateral ureteral obstruction (UUO) to establish the in vivo RIF model. MVs were extracted from the obstructed kidney tissues of mice, to further isolate the RNAs. MiRNA-153-3p levels in RIF mice and MVs were determined. In vitro RIF model was constructed by TGF-β1 induction in NRK-52E and NRK-49F cells. The regulatory effect of miRNA-153-3p on the apoptosis of tubular epithelial cells was examined. Subsequently, potential target gene of miRNA-153-3p was predicted and identified. Rescue experiments were finally carried out to uncover the role of miRNA-153-3p/Bcl-2 in influencing RIF.

RESULTS

MiRNA-153-3p was upregulated in mice undergoing UUO, MVs extracted from obstructed kidney tissues of mice and TGF-β1-induced NRK-52E and NRK-49F cells. The overexpression of miRNA-153-3p remarkably induced apoptosis in tubular epithelial cells. Bcl-2 was verified to be the target gene of miRNA-153-3p, and the Bcl-2 level was negatively regulated by miRNA-153-3p. Overexpression of Bcl-2 reversed the effect of miRNA-153-3p on inducing cell apoptosis.

CONCLUSIONS

MV-containing miRNA-153-3p released by tubulointerstitial fibroblasts transmits to the proximal tubular epithelial cells via the damaged tubule basement membrane. It induces the apoptosis of proximal tubular epithelial cells by inhibiting Bcl-2 level and further aggravates RIF.

MiR-875 can regulate the proliferation and apoptosis of non-small cell lung cancer cells via targeting SOCS2

OBJECTIVE

To investigate the effect of miR-875 on the proliferation and apoptosis of non-small cell lung cancer (NSCLC) cancer cell line A549 and the related mechanism.

PATIENTS AND METHODS

30 paired tumor tissue and the adjacent tissue were collected. Real Time-quantitative Polymerase Chain Reaction (RT-qPCR) has been performed to detect the expression of miR-875 in NSCLC tissues and adjacent normal tissues. Moreover, suppressor of cytokine signaling 2 (SOCS2) has been predicted as a target of miR-875, and Dual-Luciferase reporter assay has been performed to confirm the targeting relationship; furthermore, the expression of SOCS2 in tumor tissue and the adjacent tissue were compared. Next, human NSCLC cell line A549 cells were cultured and transfected with miR-875 inhibitor with or without SOCS2 siRNA, and the proliferation and apoptosis of the cells were evaluated by Cell Counting Kit (CCK-8) and flow cytometry methods. Finally, the relative protein expression of Wnt and β-catenin were analyzed by Western blot analysis.

RESULTS

MiR-875 was significantly up-regulated in NSCLC tissues compared with the adjacent tissues. SOCS2 was confirmed as a target of miR-875, and the expression of SOCS2 was markedly decreased in NSCLC tissues. Moreover, the knockdown of miR-875 inhibited the proliferation and promoted the apoptosis of A549 cells, while transfection of SOCS2 siRNA can block miR-875 inhibitor-induced anti-proliferative effects. Finally, the transfection of miR-875 inhibitor decreased the expression of Wnt and β-catenin, and SOCS2 siRNA can reverse the effect.

CONCLUSIONS

MiR-875 may regulate the proliferation and apoptosis of NSCLC cells via targeting SOCS2, suggesting that miR-875 has the potential to become a therapeutic target for the treatment in NSCLC.

Knockdown of long noncoding RNA SNHG7 inhibits the proliferation and promotes apoptosis of thyroid cancer cells by downregulating BDNF

OBJECTIVE

Recently, long noncoding RNAs (lncRNAs) have got much attention for their role in tumor progression. LncRNA small nucleolar RNA host gene 7 (SNHG7) was studied in this research to identify how it affects the development of thyroid cancer (TC).

PATIENTS AND METHODS

SNHG7 expression was detected by quantitative Real-time polymerase chain reaction (qRT-PCR) in both TC cells and tissue samples. Pearson's Chi-square test was used to determine the association of SNHG7 expression with several clinicopathological factors. Moreover, colony formation assay, cell proliferation and cell apoptosis assay were conducted. In addition, by performing qRT-PCR and Western blot assay, the underlying mechanism was explored.

RESULTS

SNHG7 expression level was higher in TC samples than that in corresponding ones. The SNHG7 expression was associated with tumor size and TNM stage. Moreover, TC cell proliferation was inhibited, and TC cell apoptosis was induced after SNHG7 was knocked down in vitro. Moreover, the mRNA and protein expressions of brain-derived neurotrophic factor (BDNF) were downregulated after knockdown of SNHG7. Furthermore, the expression level of BDNF was positively related to the expression of SNHG7 in TC tissues.

CONCLUSIONS

These results suggested that knockdown of SNHG7 could inhibit TC cell proliferation and induce cell apoptosis via downregulating BDNF, which might be a potential therapeutic target in TC.

Survival impact of delaying postoperative chemoradiotherapy in newly-diagnosed glioblastoma patients

Background

Maximal safe resection followed by adjuvant chemoradiotherapy (CRT) with temozolomide (TMZ) is the standard treatment for newly diagnosed glioblastoma multiforme (GBM) patients. Time of initiation of postoperative adjuvant therapy has been demonstrated to impact on prognosis. For GBM patients, the optimal interval between definitive surgery and CRT is still uncertain. Current study aims to find whether the delayed initiation of CRT after surgery has a negative impact on patients’ outcome.

Methods

Sixty-six consecutively patients with newly-diagnosed GBM treated with surgery and adjuvant CRT from April 2014 to September 2019 at Ruijin Hospital School of Medicine Shanghai Jiaotong University were retrospectively reviewed. The impact of postoperative time from surgery to adjuvant treatment on patient’s overall survival (OS) and progression-free survival (PFS) were evaluated by univariate Log-rank test and multivariate Cox regression analysis. Factors including age, Karnofsky performance status (KPS), maximum diameter of primary tumor, extent of resection, isocitrate dehydrogenase (IDH) mutation status and O6-methylguanine-DNA-methyltransferase (MGMT) promoter methylation status were also analyzed in Cox regression model.

Results

The median OS for patients who started CRT less than 6 weeks (n=48) and more than 6 weeks (n=18) were 26.6 months (95% CI: 18.3–34.9) and 15.7 months (95% CI: 9.2–22.3) (P=0.001). The median PFS for the short interval group was 16.3 months (95% CI: 14.7–18.0) and for the long interval group was 9.1 months (95% CI: 4.7–13.4) (P=0.006). On multivariate Cox regression analysis, high KPS and initiation of CRT less than 6 weeks were two independent prognostic factors for better OS and PFS (all P<0.05).

Conclusions

Initiation of adjuvant CRT beyond 6 weeks contributed to worse survival in GBM patients, therefore CRT should be initiated within 6 weeks after surgery.

Assessment of Ischemic Volumes by Using Relative Filling Time Delay on CTP Source Image in Patients with Acute Stroke with Anterior Circulation Large Vessel Occlusions

BACKGROUND AND PURPOSE

Thrombectomy up to 24 hours after stroke onset in patients with specific ischemic brain volumes remains a challenge, because many stroke centers do not apply specialized software to calculate ischemic volumes at advanced imaging. We aimed to establish the association between relative filling time delay on CTP source imaging and ischemic volume parameters and the infarct penumbra to core volume mismatch in patients with acute ischemic stroke.

MATERIALS AND METHODS

Consecutive patients with acute ischemic stroke and with M1 segment MCA with or without terminal ICA occlusions on baseline CTA and CTP within 24 hours of stroke symptom onset were included. Ischemic volumes were analyzed with software based on CTP maps. Relative filling time delay was classified into 4 grades-grade 0: relative filling time delay = 0 seconds; grade 1: relative filling time delay >0 to ≤4 seconds; grade 2: relative filling time delay >4 to ≤8 seconds; and grade 3: relative filling time delay > 8 seconds. Differences in ischemic volume parameters among relative filling time delay grades were tested.

RESULTS

We recruited 138 patients (median age, 69 years; 62.3% male). Different median volumes of the infarct core (grade 0, 7.3 mL; grade 1, 23.3 mL; grade 2, 45.7 mL; grade 3, 135 mL [P < .001]) and the penumbra (grade 0, 47.6 mL; grade 1, 90 mL; grade 2, 110 mL; grade 3, 92 mL [P = .043]) were observed among relative filling time delay grades. Target mismatch (defined by the criteria of the DEFUSE 3 trial) was identified in 71.7% of the patients (99/138). A relative filling time delay grade ≤ 1 independently predicted target mismatch, with a sensitivity of 0.79 (95% CI, 0.7-0.87) and a specificity of 0.66 (95% CI, 0.49-0.8).

CONCLUSIONS

Relative filling time delay grade based on CTP source imaging is a simple and effective parameter for evaluating ischemic volumes and target mismatch in patients with acute ischemic stroke. Further studies that compare relative filling time delay grade with clinical functional outcomes are necessary.

Long non-coding RNA GHET1 promotes viability, migration and invasion of glioma cell line U251 by down-regulation of miR-216a

OBJECTIVE

Glioma is among the most aggressive of all human malignancies. Long non-coding RNA (lncRNA) gastric carcinoma highly expressed transcript 1 (GHET1) was considered an important oncogene in tumors. However, the role of GHET1 in glioma was rarely studied. The present work aimed to explore the effect of GHET1 on glioma cell line U251.

MATERIALS AND METHODS

The viability, migration and invasion of U251 cells were analyzed by Cell Counting Kit-8 (CCK-8) assay, and transwell migration/invasion assay, respectively. The relative expression of GHET1 and miR-216a were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The expression of cell cycle-related proteins, cell metastasis-associated proteins and main factors in the JAK2/STAT3 and p53/survivin pathways was analyzed by Western blot. Cell transfection assay was conducted to alter expression of GHET1 and miR-216a in U251 cells.

RESULTS

The viability, migration and invasion of U251 cells were promoted by GHET1 overexpression. The pro-cell cycle genes including Cyclin D1, CDK4 and CDK6, and the pro-metastasis genes including MMP-9 and Vimentin were up-regulated after GHET1 was overexpressed. MiR-216a was found to be down-regulated by GHET1 overexpression, and it was involved in the effects of GHET1 on U251 cells. GHET1 might promote U251 cells by down-regulating miR-216a. Finally, we found that GHET1 overexpression activated the JAK2/STAT3 and p53/survivin signaling pathways by down-regulating miR-216a.

CONCLUSIONS

GHET1 overexpression increased viability, migration and invasion of U251 cells by down-regulating miR-216a. Mechanically, GHET1-miR-216a axis activated the JAK2/STAT3 and p53/survivin signaling pathways.

[The balance of proinflammatory cytokines and Treg cells in chronic glomerulonephritis]

Chronic glomerulonephritis (CGN) is a disease with a steadily progressing course, which is based on inflammation with the activation of immune cells. The severity of the inflammatory reaction in the kidney tissue is determined by the balance of locally pro-inflammatory factors and protective mechanisms, which include anti-inflammatory cytokines and T-regulatory lymphocytes (Treg). The study of processes that can modulate the severity of inflammation in the kidney is of particular interest for understanding the basic patterns of CGN progression.

AIM

To determine the clinical significance of the Th17, Th1, and Treg cytokines in urine to assess the activity and progression of chronic glomerulonephritis with nephrotic syndrome (NS).

MATERIALS AND METHODS

The study included 98 patients with CGN 37 women and 61 men. Patients were divided into two groups according to the degree of CGN activity. Group I consisted of 51 patients with NS. In 21 subjects, a decrease in GFR60 ml/min was revealed. Group II included 47 patients with proteinuria from 1 to 3 g/day without NS. GFR60 ml/min/1.73 m2 was observed in 26 patients. A kidney biopsy was performed in 65 patients and the hystological diagnosis was verified: 20 had mesangioproliferative GN, 16 had membranous nephropathy, 18 had focal segmental glomerulosclerosis, and 11 had membranoproliferative GN. The control group consisted of 15 healthy people. The levels of IL-6, IL-10, IL-17, tumor necrosis factor a (TNF-a) in the urine were determined using enzyme-linked immunosorbent assay. The number of FoxP3-positive cells in the inflammatory interstitial infiltrate of the cortical layer was determined in 39 patients (in a biopsy sample in a 1.5 mm2 area).

RESULTS

In group of patients with CGN, there was an increase in the levels of Th17, Th1, and Treg cytokines in urine TNF-a and IL-10 compared with healthy individuals. An increase in the levels of IL-6 in the urine of patients with high clinical activity of CGN (with NS and renal dysfunction) was more pronounced than in patients with NS and normal renal function. There was a decrease in the number of Treg cells in the interstitium of the kidney and a decrease in the production of anti-inflammatory IL-10 in CGN patients with NS, compared with patients without NS. The most pronounced changes in the cytokine profile were observed in patients with FSGS with an increase in pro-inflammatory cytokines and a decrease in Treg in the kidney tissue/anti-inflammatory IL-10 in the urine.

CONCLUSION

An imbalance of cytokines characterized by an increased levels of pro-inflammatory IL-17, IL-6, TNF-a, and a reduced levels of anti-inflammatory IL-10 and T-regulatory cells in the kidney tissue is noted in patients with NS, especially with FSGS. Imbalance of cytokines reflects the high activity of CGN and the risk of the progression of the disease.

3D-GLCM CNN: A 3-Dimensional Gray-Level Co-Occurrence Matrix-Based CNN Model for Polyp Classification via CT Colonography

Accurately classifying colorectal polyps, or differentiating malignant from benign ones, has a significant clinical impact on early detection and identifying optimal treatment of colorectal cancer. Convolution neural network (CNN) has shown great potential in recognizing different objects (e.g. human faces) from multiple slice (or color) images, a task similar to the polyp differentiation, given a large learning database. This study explores the potential of CNN learning from multiple slice (or feature) images to differentiate malignant from benign polyps from a relatively small database with pathological ground truth, including 32 malignant and 31 benign polyps represented by volumetric computed tomographic (CT) images. The feature image in this investigation is the gray-level co-occurrence matrix (GLCM). For each volumetric polyp, there are 13 GLCMs, computed from each of the 13 directions through the polyp volume. For comparison purpose, the CNN learning is also applied to the multi-slice CT images of the volumetric polyps. The comparison study is further extended to include Random Forest (RF) classification of the Haralick texture features (derived from the GLCMs). From the relatively small database, this study achieved scores of 0.91/0.93 (two-fold/leave-one-out evaluations) AUC (area under curve of the receiver operating characteristics) by using the CNN on the GLCMs, while the RF reached 0.84/0.86 AUC on the Haralick features and the CNN rendered 0.79/0.80 AUC on the multiple-slice CT images. The presented CNN learning from the GLCMs can relieve the challenge associated with relatively small database, improve the classification performance over the CNN on the raw CT images and the RF on the Haralick features, and have the potential to perform the clinical task of differentiating malignant from benign polyps with pathological ground truth.

[Clinical and coagulation characteristics in 7 patients with critical COVID-2019 pneumonia and acro-ischemia]

Objective: To investigate the clinical and coagulation characteristics in patients with critical Coronavirus disease 2019 (COVID-19) and acro-ischemia. Methods: The retrospective study included 7 critical COVID-19 patients with acro-ischemia in an intensive care unit (ICU) in Wuhan, from Feb 4 to Feb 15, 2020. The clinical and laboratory data before and during the ICU stay were analyzed. Results: The median age of 7 patients was 59 years and 4 of them were men. Three patients were associated with underlying comorbidities. Fever, cough, dyspnea and diarrhea were common clinical symptoms. All patients had acro-ischemia presentations including finger/toe cyanosis, skin bulla and dry gangrene. D-dimer, fibrinogen and fibrinogen degradation product (FDP) were significantly elevated in most patients. Prothrombin time was prolonged in 4 patients. D-dimer and FDP levels progressively elevated consistent with COVID-2019 exacerbation. Four patients were diagnosed with disseminated intravascular coagulation (DIC) . Low molecular weight heparin (LMWH) was administrated in 6 patients, which reduced D-dimer and FDP rather than improved clinical symptoms. Five patients died finally and the median time from acro-ischemia to death was 12 days. Conclusions: Coagulation parameters should be monitored closely in critical COVID-2019 patients. The timing and protocol of anticoagulation therapy are still under investigation based on more clinical data.

Utility of circulating tumor DNA in genomic profiling of colorectal cancer with peritoneal metastasis

e16057

Background: Patients (pts) with peritoneal metastatic (PM) colorectal cancer (CRC) have significantly poorer prognosis than those with other metastases. In this study, we aim to investigate genomic profiles of PM-CRC and metastatic CRC without peritoneal involvement (non-PM-CRC) and PM-CRC with other organ involvement (PM-CRC+) using circulating tumor DNA (ctDNA)-based sequencing. Methods: A total of 169 pts with metastatic CRC were enrolled irrespective of treatment history, including 53 pts with non-PM-CRC, 47 pts with PM-CRC, and 69 pts with PM-CRC+. Matched tumor-normal next-generation sequencing of 1021 cancer-related genes was performed on ctDNA and white blood cells derived from plasma samples. The differences of mutation number were examined with student t test, and the differences of mutation detection rate were examined with two tailed Fisher’s exact test. p≤0.05 was considered statistically significant. Results: Somatic mutations were identified in 96% of pts with non-PM-CRC, 77% of pts with PM-CRC, and 97% of pts with PM-CRC+. The number of somatic mutations observed in the PM-CRC cohort was significantly lower than that in the other cohorts with the median value of 2 in the PM-CRC cohort, 9 in the non-PM-CRC cohort, and 7 in the PM-CRC+ cohort (p = 0.0002 and p < 0.0001, respectively). The most frequently mutated genes in these cohorts was listed in Table. The detection rate of APC and TP53 mutations in the PM-CRC cohort was significantly lower than the other cohorts. Significant differences were also observed when comparing TCF7L2 mutations in the non-PM-CRC and the other cohorts, LRP1B mutations in the PM-CRC cohort and PM-CRC+ cohort, and NOTCH4 and PCK1 mutations in the non-PM-CRC and PM-CRC+ cohorts. In addition, BRAF mutations were more commonly observed in the PM-CRC cohort (13%) than the other cohorts (8% for non-PM-CRC cohort, 4% for PM-CRC+ cohort) (p = 0.51 and 0.16, respectively). Conclusions: Pts with PM-CRC exhibit a distinct molecular profile compared with non-PM-CRC and PM-CRC+, which may be helpful to explain their relatively poor prognosis and potentially be used in the early diagnosis of PM. [Table: see text]

[Analysis on the trend of physical development of children aged 7-17 years old in China from 1982 to 2012]

Data of physical measurement of children aged 7-17 years old in China was from National Nutrition and Health Survey in 1982, 1992, 2002 and 2010-2012. From 1982 to 2012, the height and weight of children aged 7-17 years old continued to increase. The height of urban boys, urban girls, rural boys and rural girls ranged from 118.8 to 171.1, 117.8 to 159.9, 113.3 to 168.2 and 111.7 to 158.1 cm, and weight ranged from 21.3 to 61.4, 20.2 to 53.1, 19.4 to 57.9, and 19.0 to 51.5 kg, respectively. The height and weight of urban children were larger than those of rural children. The height and weight of boys were larger than those of girls, except for adolescents. From 1982 to 2012, the height increment of urban boys, urban girls, rural boys and rural girls was 8.8, 6.2, 12.9 and 10.8 cm, and weight increment was 9.9, 6.2, 9.8 and 7.6 kg, respectively. The increment of urban children was smaller than that of rural children, which implied that the disparity between urban and rural was shrinking. The increment of boys was larger than that of girls, which implied that the gender disparity was increasing.

Multilayer feature selection method for polyp classification via computed tomographic colonography

Polyp classification is a feature selection and clustering process. Picking the most effective features from multiple polyp descriptors without redundant information is a great challenge in this procedure. We propose a multilayer feature selection method to construct an optimized descriptor for polyp classification with a feature-grouping strategy in a hierarchical framework. First, the proposed method makes good use of image metrics, such as intensity, gradient, and curvature, to divide their corresponding polyp descriptors into several feature groups, which are the preliminary units of this method. Then each preliminary unit generates two ranked descriptors, i.e., their optimized variable groups (OVGs) and preliminary classification measurements. Next, a feature dividing-merging (FDM) algorithm is designed to perform feature merging operation hierarchically and iteratively. Unlike traditional feature selection methods, the proposed FDM algorithm includes two steps for feature dividing and feature merging. At each layer, feature dividing selects the OVG with the highest area under the receiver operating characteristic curve (AUC) as the baseline while other descriptors are treated as its complements. In the fusion step, the FDM merges some variables with gains into the baseline from the complementary descriptors iteratively on every layer until the final descriptor is obtained. This proposed model (including the forward step algorithm and the FDM algorithm) is a greedy method that guarantees clustering monotonicity of all OVGs from the bottom to the top layer. In our experiments, all the selected results from each layer are reported by both graphical illustration and data analysis. Performance of the proposed method is compared to five existing classification methods by a polyp database of 63 samples with pathological reports. The experimental results show that our proposed method outperforms other methods by 4% to 23% gains in terms of AUC scores.

[Clinical and coagulation characteristics of 7 patients with critical COVID-2019 pneumonia and acro-ischemia]

Objective: To investigate the clinical and coagulation characteristics of the critical Coronavirus disease 2019 (COVID-19) patients with acro-ischemia in the intensive care unit (ICU). Methods: The retrospective study included 7 critical COVID-19 patients with acro-ischemia in a single center in Wuhan, from Feb 4 to Feb 15, 2020. The clinical and laboratory data before and during the ICU stay were analyzed. Results: The median age of 7 patients was 59 years and 4 of them were men. 3 of them were associated with underlying comorbidities. Fever, cough, dyspnea and diarrhea were common clinical symptoms. All patients had acro-ischemia presentations including finger/toe cyanosis, skin bulla and dry gangrene. D-dimer, fibrinogen and fibrinogen degradation product (FDP) were significantly elevated in most patients. Prothrombin time (PT) were prolonged in 4 patients. D-dimer and FDP levels increased progressively when COVID-2019 exacerbated, and 4 patients were diagnosed with definite disseminated intravascular coagulation (DIC). 6 patients received low molecular weight heparin (LMWH) treatment, after which their D-dimer and FDP decreased, but there was no significant improvement in clinical symptoms. 5 patients died finally and the median time from acro-ischemia to death was 12 days. Conclusions: The existence of hypercoagulation status in critical COVID-2019 patients should be monitored closely, and anticoagulation therapy can be considered in selected patients. More clinical data is needed to investigate the role of anticoagulation in COVID-2019 treatment.

Prognostic value of nasopharynx tumour volume in local-regional advanced nasopharyngeal carcinoma

Background

To investigate the prognostic value of pretreatment primary gross tumor with (GTVp) and without retropharyngeal lymph nodes (GTVnx) for predicting survival outcomes in patients with local-regional advanced nasopharyngeal carcinoma (NPC) after intensity-modulated radiation therapy (IMRT).

Methods

From Jan 2012 to Dec 2017, 148 patients with local-regional advanced NPC who had undergone definitive radiotherapy were identified. GTVnx volume and retropharyngeal lymph nodes (GTVrLNs) volume were measured based on registration of MRI with contrast-enhanced CT images. The Kaplan-Meier method was used for survival analysis. Univariate and multivariate prognostic analyses was performed by using the Cox proportional hazard model. Receiver operating characteristic (ROC) curves were used to identify the cut-off point and assess the prognostic value for GTVnx, GTVp and GTVrLNs.

Results

The median follow-up time for the entire group was 27 months (ranging 7 to 80 months). The 3-year overall survival (OS) rate was 85%, and the 3-year local failure-free rate (LFFR), distant failure-free rate (DFFR) and disease-free survival (DFS) rates were 93%, 81%, and 73%, respectively. A positive correlation between GTVnx or GTVp volume and T stage was observed (both P<0.001). The 3-year LFFR, OS, and DFS rate, but not for DMFS, in NPC patients with GTVnx ≤42.7 cm³ was significantly better than those with >42.7 cm³ (all P<0.05). Multivariate analysis indicated that GTVnx volume (P=0.041) was the only independent prognostic factor for LFFR, while age and AJCC stage were two independent prognostic factors for OS.

Conclusions

The GTVnx is an independent prognostic factor for local control, while the prognostic value of GTVrLNs is limited. Physicians are recommended to distinguish between GTVnx and retropharyngeal lymph nodes (RLN) involvement when assessing the risk for local recurrence in advanced NPC.

[Voxel-based morphometry study of the brain structures in patients with congenital hereditary hearing loss]

Objective: To analyze the physiological basics for changes of cerebral functions in patients with congenital hereditary hearing loss (CHHL), by using voxel-based morphometry (VBM). Methods: From June 2016 to June 2017, we recruited volunteers from Yangzhou Special Education School and CHHL patients from the Department of Otorhinolaryngology, Subei People's Hospital as a case group with a total of 14 cases (8 males and 6 females), with an average age from 10 to 18 (13.13 ± 0.39). At the same time,patients with no ear diseases were recruited as a control group, a total of 23 cases (10 males and 13 females), with an average age from 10 to18 (13.50 ± 0.49). Brain scanning with resting state functional magnetic resonance imaging was performed on all subjects, and 3D T1WI was collected and processed by the analyzing software. Two sample t-tests were conducted with alphasim correction at the threshold level of P<0.001. Different morphologies of cerebral cortex were identified between patients with CHHL and their normal controls retrospectively. Results: Compared to their normal controls, patients with CHHL had no significant difference in terms of brain volume, gray matter volume, white matter volume, and cerebrospinal fluid volume ((1 397.53±103.98)cm(3) vs. (1 439.45±128.84)cm(3), (765.19±60.27)cm(3) vs. (800.139±77.64)cm(3), (392.89±40.38)cm(3) vs. (414.54±49.22)cm(3), (314.17±25.81)cm(3) vs. (296.47±51.42)cm(3), all P>0.05). However, compared to their normal controls, patients with CHHL had significantly increased (P<0.001) gray matter in the following cerebral gyri: right temporal pole: middle temporal gyrus, right inferior temporal gyrus, left middle occipital gyrus, right inferior parietal gyrus, and left middle frontal gyrus, left superior occipital gyrus, right superior frontal gyrus, and left superior frontal gyrus. Furthermore, compared to their normal controls, patients with CHHL had significantly decreased (P<0.001) gray matter in the following cerebral gyri: left parahippocampal gyrus, right fusiform gyrus, right middle frontal gyrus, left inferior temporal gyrus, right middle occipital gyrus, left insula, right inferior frontal gyrus, left precentral gyrus, and right superior parietal gyrus. Conclusions: Patients with CHHL show global changes in cerebral cortex not limited to auditory associated cerebral areas. This suggests that adaptable reshaping of global brain structures and functions has occurred in patients with CHHL.