Cell wall thickness and the molecular mechanism of heterogeneous vancomycin-intermediate Staphylococcus aureus

Methicillin‐resistant Staphylococcus aureus (MRSA) with reduced sensitivity to vancomycin (VAN) has caused many clinical cases of VAN treatment failure, but the molecular mechanism underlying the reduced sensitivity to VAN is still unclear. We isolated a heterogeneous VAN‐intermediate Staphylococcus aureus (hVISA), which was also a MRSA strain with reduced sensitivity to VAN. To investigate the molecular mechanism underlying the reduced sensitivity to VAN exhibited by the hVISA strain, we compared the hVISA strain with a VAN‐sensitive MRSA strain, known as the N315 strain. The images captured by transmission electron microscopy showed that the cell wall of the hVISA strain was significantly thicker than that of the N315 strain (36·72 ± 1·04 nm vs 28·15 ± 1·25 nm, P < 0·05), and the results of real‐time quantitative PCR analysis suggested that the expression levels of the cell wall thickness related genes (glmS, vraR/S, sgtB, murZ and PBP4) of the hVISA strain were significantly higher than those of the N315 strain (P < 0·05). In conclusion, this study indicated that the upregulation of the expression of the genes related to cell wall synthesis might be the molecular mechanism underlying the cell wall thickening of the hVISA strain and might be related to its resistance to VAN.

[Clinical characteristics and related factors of acute tubular necrosis in patients with minimal change disease]

Objective: To investigate the clinical characteristics and related factors of acute tubular necrosis (ATN) in patients with minimal change disease (MCD). Methods: Patients from Chinese PLA General Hospital who were pathologically diagnosed with MCD and had clinical manifestations of nephrotic syndrome from January 1, 2013 to December 31, 2019 were included. The clinical and pathological data of patients were retrospectively analyzed. Meanwhile, the incidence and clinical characteristics of ATN in different age groups were compared. The risk factors for ATN were assessed using binary logistic regression. Results: A total of 525 patients were included, with a gender ratio of 1.56∶1 (male: female), aged 33 (21, 48) years old. ATN occurred in 49 (9.3%) of 525 patients, of which 34 were male and 15 were female. The incidence of ATN increased with age in MCD patients of different age groups (χ(2)=31.442, P<0.001). The incidence of ATN in groups of age≤20 years, 21-40 years, 41-60 years, and >60 years was 2.4% (3/123), 5.2% (10/192), 13.2% (20/152) and 27.6% (16/58), respectively. Elevations of alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyl transpeptidase (GGT) and serum IgE occurred in 92 patients (17.5%), 53 patients (10.1%), 99 patients (18.9%), and 303 patients (57.7%), respectively. There were significant differences in age, ALT, serum creatinine, serum urea nitrogen, history of diabetes and history of hypertension between non-ATN group and ATN group (all P<0.05). The results of logistic regression analysis showed that>40 years old (OR=6.283, 95% CI: 2.695-14.649, P<0.001) and serum albumin (OR=0.924, 95% CI: 0.857-0.997, P=0.040) was independently associated with ATN in MCD patients. Conclusion: Age>40 years is an independent risk factor and serum albumin is a protective factor for ATN in MCD patients.

[Intraobserver reproducibility of Ki-67 assessment of breast cancers based on digital slide]

Objective: To investigate the intra-observer reproducibility of Ki-67　　　assessment in breast cancers using three methods based on digital slide. Methods: Thirty cases of invasive breast cancer tissues were immunostained for Ki-67 by automatic stainer, and then scanned into digital pathological slides. Ki-67 positive index was measured individually by three pathologists using size-set visual assessment of hot spot (SSVAHS), size-set semi-automatic counting of hot spot(SSSACHS), and size-set automatic counting of hot spot (SSACHS), respectively, and repeated for 10 times. Intraclass correlation coefficient (ICC) of each assessment method was calculated, and the intraobserver reliability was classified as excellent, good, fair and poor according to ICC. Results: The ICC by 3 pathologists using SSVAHS was 0.832, 0.843 and 0.826, respectively, The ICC using SSSACHS was 0.926,0.938,0.929, and the ICC using SSACHS was 0.964, 0.971 and 0.968.The intraobserver reliability level of all three methods was excellent. Conclusion: The three methods of Ki-67 assessment achieve satisfactory intraobserver reproducibility, and the order of reproducibility from high to low is SSACHS, SSSACHS, and SSVAHS.

[Transthoracic implantation of dual-chamber pacemaker for synchronous treatment of cardiac dysfunction due to idiopathic complete left bundle branch block in children]

Objective: To investigate the efficacy and feasibility of transthoracic implantation of permanent left atrial and left ventricular dual-chamber pacemaker for synchronous treatment of cardiac dysfunction due to idiopathic complete left bundle branch block (CLBBB) in children. Methods: The clinical data of five children with cardiac dysfunction due to idiopathic CLBBB and accepting implantation of permanent left atrial and left ventricular epicardial dual chamber pacemaker from January 2015 to July 2019 at the Pediatric Cardiologic Department of the First Hospital of Tsinghua University were analyzed retrospectively. The effects of pacemaker implantation on patients' cardiac function and cardiac synchrony were evaluated by echocardiogram. Results: Among 5 patients, 2 were males and 3 females. At the time of pacemaker implantation, the age of these patients was 0.5-5.7 years, the left ventricle ejection fraction (LVEF) was 29%-46%, the left ventricle end stage of diastolic diameter was 30-53 mm and the mean Z score was 4.0-34.0. Pacemaker was successfully implanted for all the patients. After the implantation, medications that can suppress atrioventricular node conduction were used and sensed atrioventricular delay (SAV) parameters were modulated until patients' QRS duration became shortest and the percentage of left ventricular pacing increased to and maintained at 97% to 100%. Patients' QRS duration was 120-160 ms before implantation and 90-120 ms after implantation. Patients' cardiac function began to improve 1 day to 1 month after implantation. Patients' cardiac function normalized after a mean of 1-12 months. LVEF increased from 29%-46% to 55%-67%. During the follow-up, interventricular mechanical delay, septal-to-posterior wall motion delay, and left ventricular systolic dyssynchrony index decreased significantly: IVMD decreased from 31-62 ms to 26-50 ms; SPWMD decreased from 40-63 ms to 10-50 ms and Ts-SD decreased from 34.3-50.3 ms to 16.3-31.4 ms. The global longitudinal strain of left ventricle decreased from -7.7%--13.8% to -13.5%--20.3%. Conclusion: Cardiac dysfunction due to CLBBB in children can be treated with transthoracic implantation of permanent epicardial left atrial and left ventricular dual chamber pacemaker which can substitute three chamber pacemaker to achieve the effects of synchronous therapy that lead to reversion and normalization of cardiac function.

CT and MRI features of giant cell tumours with prominent aneurysmal bone cysts in the extremities: a comparison with primary aneurysmal bone cysts

AIM

To test the hypothesis that computed tomography (CT) and magnetic resonance imaging (MRI) could help distinguish between giant cell tumours with prominent aneurysmal bone cysts (GABCs) and primary aneurysmal bone cysts (PABCs) of the extremities.

MATERIALS AND METHODS

CT and MRI features of 13 patients with GABCs and 13 patients with PABCs in the extremities were analysed retrospectively. The ages and sex of the patients were also recorded. Independent-samples t-tests were used for continuous variables and Fisher's exact tests were used for categorical variables to compare the differences between the two groups. Diagnostic accuracy, sensitivity, and interobserver agreement were calculated.

RESULTS

The average age of patients with GABCs (38.2±15.8 years) was higher than that of patients with PABCs (19.3±12.7 years; p=0.003). The transverse/longitudinal diameter ratio was different between GABCs (0.8±0.3) and PABCs (0.6±0.2; p=0.007). Subchondral bone involvement (92.3% versus 30.8%, p=0.004) and deep lobulation (38.5% versus 0%, p=0.039) were more likely to be noted in patients with GABCs. Surrounding blood vessels were identified in six cases of PABCs (6/13), but not in GABCs (p=0.015). The following characteristics were suggestive of GABCs, older patient age, higher transverse/longitudinal diameter ratio, subchondral bone involvement, and deep lobulation indicated a sensitivity of 84.6%, 76.9%, 75%, and 100%, and a specificity of 84.6%, 69.2%, 90%, and 61.9%, respectively. Conversely, surrounding blood vessels were suggestive of PABCs, with a sensitivity of 46.2% and specificity of 100%. The concordance between the two readers was moderate to nearly perfect.

CONCLUSION

Age, subchondral bone involvement, lobulation, transverse/longitudinal diameter ratio, and surrounding blood vessels can be used to distinguish GABCs from PABCs.

Oncogene miR-934 promotes ovarian cancer cell proliferation and inhibits cell apoptosis through targeting BRMS1L

OBJECTIVE

Ovarian cancer is a common malignant cancer among women. Increasing studies have demonstrated that microRNAs function as important regulation factors in the progression of ovarian cancer.

MATERIALS AND METHODS

Human ovarian cancer cell lines HO8910 and OVCAR-3 were transfected with miR-934 inhibitor and corresponding negative control (inhibitor control). Cell proliferation and apoptosis were detected by cell counting kit-8 (CCK-8) and TUNEL assay, respectively. The expression levels of proliferation/apoptosis-related genes and BRMS1L were measured by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) and Western blotting. Furthermore, the association between miR-934 and BRMS1L was investigated through luciferase reporter assays.

RESULTS

MiR-934 was significantly increased in ovarian cancer cell lines, whereas BRMS1L was significantly decreased. Downregulated miR-934 remarkably inhibited cell proliferation and induced cell apoptosis. Meanwhile, miR-934 could influence the expression levels of Ki67, Cyclin D1, Caspase3, and Bcl-2. In addition, BRMS1L was identified as a target gene of miR-934.

CONCLUSIONS

Oncogene miR-934 promotes ovarian cancer cell proliferation and inhibits cell apoptosis through targeting BRMS1L. MiR-934 and BRMS1L may be novel biomarkers or therapeutic targets for ovarian cancer in the future.

MiR-99a suppressed cell proliferation and invasion by directly targeting HOXA1 through regulation of the AKT/mTOR signaling pathway and EMT in ovarian cancer

OBJECTIVE

Ovarian cancer (OC) is the third frequently tumor worldwide. MicroRNA-99a (miR-99a), acting as a tumor suppressor, has been reported to be downregulated in multiple tumors. We aimed at exploring the significant roles of miR-99a in ovarian cancer.

PATIENTS AND METHODS

Quantitative Real-time polymerase chain reaction (qRT-PCR) and Western blotting were applied to calculate the mRNA and protein levels of miR-99a and its target genes. Kaplan-Meier method was conducted to evaluate the overall survival of ovarian cancer patients. CCK8 and transwell assays were performed to measure the proliferative and invasive abilities.

RESULTS

miR-99a, acting as a prognosis predictor, was downregulated in ovarian cancer tissues and cell lines. miR-99a mediated the expression of homeobox A1 (HOXA1) through directly targeting to the 3'-untranslated region (3'-UTR) of its mRNA in ovarian cancer cell lines. miR-99a inhibited the proliferation of ovarian cancer by AKT/mTOR pathway in vitro and in vivo, and it suppressed the invasion-mediated epithelial-mesenchymal transition (EMT) through direct targeting to the 3'-UTR of HOXA1 mRNA.

CONCLUSIONS

miR-99a suppressed the proliferation through AKT/mTOR signaling pathway and the invasion-mediated EMT in ovarian cancer. The newly identified miR-99a/HOXA1/AKT/mTOR axis provides novel insight into the pathogenesis of ovarian cancer.

Long non-coding RNA LINC01287 promotes breast cancer cells proliferation and metastasis by activating Wnt/ß-catenin signaling

OBJECTIVE

Long noncoding RNA (lncRNAs) frequently exhibited abnormal levels in numerous tumors and other diseases in current biological researches. LINC01287, a newly discovered lncRNA, has been found to act as an oncogene in hepatocellular carcinoma. The aim of this research was to explore the expressions and functions of LINC01287 in breast cancer (BC).

PATIENTS AND METHODS

The relative expressions of LINC01287 in BC tissues and cells were determined using RT-PCR. The associations between the LINC01287 expression, the clinicopathological factors, and the overall survival of BC patients were statistically examined. The apoptosis and proliferation abilities of MCF-7 and MDA-MB-468 cells were analyzed by MTT and flow cytometry assay after LINC01287 knockdown. The effects of LINC01287 in migration and invasion were determined using wound-healing and transwell assays. The protein expressions of the Wnt/β-catenin pathway were determined using Western blot.

RESULTS

We showed that the levels of LINC01287 were significantly upregulated in BC tissues and BC cell lines, and the abnormal expressions of LINC01287 were correlated with TNM stage and lymph node metastasis. A distinct difference was observed and indicated that BC patients with higher LINC01287 expressions had significantly shorter overall survival than patients with lower LINC01287 expressions. The multivariate analysis demonstrated that LINC01287 expression was independently correlated with the overall survival. Si-LINC01287 transfection significantly inhibited the proliferation and metastasis of BC cells, and further promoted apoptosis. Besides, the knockdown of LINC01287 suppressed Wnt/β-catenin activation and affected the expressions of β-catenin, cyclin D1, and c-myc.

CONCLUSIONS

Our findings indicated that the new lncRNA LINC01287 was correlated with poor clinical outcome and may function as a novel prognostic biomarker and therapeutic target in the development of antineoplastic therapies for BC.