Injectable temperature-sensitive hydrogel facilitating endoscopic submucosal dissection

Purpose: Early gastrointestinal tumors can be removed by endoscopic procedures. Endoscopic mucosal dissection (ESD) requires submucosal fluid injection to provide mucosal elevation and prevent intraoperative perforation. However, the clinically applied normal saline mucosal elevation height is low for a short time, which often requires multiple intraoperative injections that increase the inconvenience and procedure time. In addition, recently researched submucosal injection materials (SIM) suffer from complex preparation, poor economy, and poor biocompatibility. Therefore, there is an urgent need for a new type of SIM that can provide long, safe and effective mucosal elevation in support of the endoscopic procedures. Methods: The FS hydrogel is based on polyethylene-polypropylene glycol (F-127) mixed with sodium alginate (SA). The different physicochemical properties of FS hydrogels were characterized through various experiments. Afterward, various biosafety assessments were carried out. Finally, the performance of FS hydrogels was evaluated by in vitro submucosal injection and in vivo swine ESD. Results: The experimental results show that the FS hydrogel is liquid at room temperature, making it easy to inject, and when injected under the mucosa, it undergoes temperature-induced cross-linking, transforming from a liquid to a solid state to provide long-lasting mucosal augmentation. At the same time, the FS hydrogel exhibits controllable gelation, stability, and biocompatibility. The results of in vitro submucosal injections and in vivo ESD procedures showed that FS achieves high mucosal augmentation and provides good submucosal cushioning in the long term. Conclusion: In summary, the F-127/SA hydrogel is simple to synthesize, cost-effective, safe, easy to store, and able to assist ESD well from the perspective of practical clinical problems, indicating that the FS hydrogel can be an ideal potent submucosal injection substitution.

Development and external validation of a machine learning model for prediction of survival in undifferentiated pleomorphic sarcoma

PURPOSE

Machine learning (ML) algorithms to predict cancer survival have recently been reported for a number of sarcoma subtypes, but none have investigated undifferentiated pleomorphic sarcoma (UPS). ML is a powerful tool that has the potential to better prognosticate UPS.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was queried for cases of histologically confirmed undifferentiated pleomorphic sarcoma (UPS) (n = 665). Patient, tumor, and treatment characteristics were recorded, and ML models were developed to predict 1-, 3-, and 5-year survival. The best performing ML model was externally validated using an institutional cohort of UPS patients (n = 151).

RESULTS

All ML models performed best at the 1-year time point and worst at the 5-year time point. On internal validation within the SEER cohort, the best models had c-statistics of 0.67-0.69 at the 5-year time point. The Multi-Layer Perceptron Neural Network (MLP) model was the best performing model and used for external validation. Similarly, the MLP model performed best at 1-year and worst at 5-year on external validation with c-statistics of 0.85 and 0.81, respectively. The MLP model was well calibrated on external validation. The MLP model has been made publicly available at https://rachar.shinyapps.io/ups_app/ .

CONCLUSION

Machine learning models perform well for survival prediction in UPS, though this sarcoma subtype may be more difficult to prognosticate than other subtypes. Future studies are needed to further validate the machine learning approach for UPS prognostication.

The efficacy of peritoneal flap fixation on symptomatic lymphocele formation following robotic-assisted laparoscopic radical prostatectomy with pelvic lymph node dissection: a systematic review and meta-analysis

BACKGROUND

Pelvic lymphocele is the most common complication after robot-assisted radical prostatectomy (RARP) with pelvic lymph node dissection (PLND), of which symptomatic lymphocele (sLC) ranges up to 10% and is associated with poorer perioperative outcomes. Peritoneal flap fixation (PFF) is a promising intraoperative modification to reduce sLC formation but the clinical evidence failed to reach consistency.

MATERIALS AND METHODS

Randomized and nonrandomized comparative studies comparing postoperative sLC occurrence with or without PFF after RARP with PLND were identified through a systematic literature search via MEDLINE/PubMed, Embase, Web of Science, and CENTRAL up to July 2023. Outcome data of sLC occurrence (primary) and major perioperative events (secondary) were extracted. Mean difference and risk ratio with 95% CI were synthesized as appropriate for each outcome to determine the cumulative effect size.

RESULTS

Five RCTs and five observatory studies involving 3177 patients were finally included in the qualitative and quantitative analysis. PFF implementation significantly reduced the occurrence of sLC (RR 0.35, 95% CI: 0.24-0.50), and the specific lymphocele-related symptoms, without compromised perioperative outcomes including blood loss, operative time, and major nonlymphocele complications. The strength of the evidence was enhanced by the low risk of bias and low inter-study heterogeneity of the eligible RCTs.

CONCLUSION

PFF warrants routine implementation after RARP with PLND to prevent or reduce postoperative sLC formation.

Robotic Frameless Stereotactic Aspiration with Thrombolysis for Primary Pontine Hemorrhage: A Therapeutic Evaluation of a Retrospective Cohort Study

INTRODUCTION

It remains controversial whether primary pontine hemorrhage (PPH) should be managed conservatively or treated promptly via surgical evacuation of the hematoma. The purpose of this study was to assess the therapeutic effect of robotic frameless stereotactic aspiration with thrombolysis in the treatment of PPH.

METHODS

A total of 39 patients with PPH between January 2012 and November 2016 were included in the study. Sixteen patients with frameless stereotactic surgical treatment (ST group) and twenty-three patients with conservative treatment (CT group). Clinical and radiological parameters were assessed, and patient outcomes were analyzed over a 6-month follow-up period.

RESULTS

Surgical treatment did not result in any intracranial infections, or complications. Baseline characteristics did not significantly differ between the two groups. At discharge, the average Glasgow Coma Scale (GCS) score and the overall Glasgow Outcome Scale (GOS) score were significantly higher in the ST group compared to the CT group (P < 0.05). The mortality rate (GOS score 1) was significantly lower in the ST group (18.75%, 3/16) than in the CT group (52.17%, 12/23). For patients with hematoma volumes of 5-10 ml or GCS scores of 6-8, following treatment, the ST group exhibited markedly higher Glasgow Outcome Scale (GOS) scores in comparison to the CT group.

CONCLUSION

In conclusion, our study suggests that robotic frameless stereotactic aspiration with thrombolysis is a safe and efficient method for the treatment of PPH. Patients with hematomas of 5-10 ml or GCS scores of 6-8 could benefit from surgery.

Expedient and divergent synthesis of unnatural peptides through cobalt-catalyzed diastereoselective umpolung hydrogenation

The development of a reliable method for asymmetric synthesis of unnatural peptides is highly desirable and particularly challenging. In this study, we present a versatile and efficient approach that uses cobalt-catalyzed diastereoselective umpolung hydrogenation to access noncanonical aryl alanine peptides. This protocol demonstrates good tolerance toward various functional groups, amino acid sequences, and peptide lengths. Moreover, the versatility of this reaction is illustrated by its successful application in the late-stage functionalization and formal synthesis of various representative chiral natural products and pharmaceutical scaffolds. This strategy eliminates the need for synthesizing chiral noncanonical aryl alanines before peptide formation, and the hydrogenation reaction does not result in racemization or epimerization. The underlying mechanism was extensively explored through deuterium labeling, control experiments, HRMS identification, and UV-Vis spectroscopy, which supported a reasonable CoI/CoIII catalytic cycle. Notably, acetic acid and methanol serve as safe and cost-effective hydrogen sources, while indium powder acts as the terminal electron source.

The protective effect of 999 XiaoErGanMao granules on the lungs and intestines of influenza A virus-infected mice

CONTEXT

Gastrointestinal symptoms are a common complication of influenza virus infection in children, which the gut-lung axis become involved in its biological progress. The protective effect of 999 XiaoErGanMao granules (XEGMG) on multi-organ injury in viral pneumonia remains unclear.

OBJECTIVE

To investigate the therapeutic effect of XEGMG on lungs and intestines injury in A/FM/1/47 (H1N1) influenza virus-infected mice.

MATERIALS AND METHODS

Male BALB/c mice were infected with the 2LD₅₀ H1N1 influenza virus and then treated with XEGMG (6 or 12 g/kg) intragastrically once a day for 4 days. The lung and colon samples were then collected for pathological observation, and assays for inflammatory cytokines and intestinal barrier. Mouse feces were collected to evaluate the intestinal microbiota.

RESULTS

Treating with XEGMG (12 g/kg) can mitigate body weight loss caused by 2LD₅₀ H1N1 infection. It can also reduce lung index and pathological damage with the decreased inflammatory cytokines such as IL-6 and IL-1β. Furthermore, XEGMG (12 g/kg) can maintain the goblet cell number in the colons to protect the intestinal barrier and regulate the major flora such as Firmicutes, Bacteroidetes, and Muribaculaceae back to normal. Meanwhile, the expression of IL-17A in the colon tissues was significantly lower in the group of XEGMG (6, 12 g/kg) compared to H1N1 group.

DISCUSSION AND CONCLUSIONS

XEGMG can protect against H1N1 invasion involved in gut-lung axis regulation. The results provide new evidence for the protective effect of XEGMG, which is beneficial to vulnerable children.

Neutrophil-to-lymphocyte ratio is associated with stroke progression and functional outcome in patients with ischemic stroke

OBJECTIVE

The objective of the present research was to examine the correlation between the neutrophil-to-lymphocyte ratio (NLR) and stroke progression (SP) as well as the functional outcome following an ischemic stroke (IS).

METHODS

The current study was conducted as prospective observational research. A cohort of 341 participants diagnosed with IS was included in the study from March 2019 to August 2021. This study's primary measure of interest was the occurrence of SP within the initial week following hospital admission. The secondary outcome was functional status 3 months after IS as measured by a modified Rankin scale score. The association between NLR with SP, and poor functional outcomes was examined using multivariate logistic regression. The predictive value of NLR for SP and poor functional outcomes was evaluated using the receiver operating characteristic (ROC) curve.

RESULTS

Among the 341 enrolled patients, 56 (16.4%) had SP, and 285 (83.6%) had no SP. The results of the multivariate logistic regression analysis demonstrated that the existence of diabetes mellitus and the NLR were independently associated with SP and poor functional outcomes. The area under the ROC curve of NLR in predicting poor functional outcome was 0.6117 (95% confidence interval, .5341-.6893, p = .0032), and the optimal cut-off point was 4.2139. The sensitivity and specificity of NLR in predicting poor functional outcomes were 52.7% and 72.0%, respectively.

CONCLUSION

Patients with acute IS exhibited a very high incidence of SP. NLR may be a valuable prognostic indicator in clinical practice because it was independently associated with SP and a poor functional outcome.

[Advance of research on endoplasmic reticulum stress and genetic epilepsy]

Epilepsies are a group of chronic neurological disorders characterized by spontaneous recurrent seizures caused by abnormal synchronous firing of neurons and transient brain dysfunction. The underlying mechanisms are complex and not yet fully understood. Endoplasmic reticulum (ER) stress, as a condition of excessive accumulation of unfolded and/or misfolded proteins in the ER lumen, has been considered as a pathophysiological mechanism of epilepsy in recent years. ER stress can enhance the protein processing capacity of the ER to restore protein homeostasis through unfolded protein response, which may inhibit protein translation and promote misfolded protein degradation through the ubiquitin-proteasome system. However, persistent ER stress can also cause neuronal apoptosis and loss, which may aggravate the brain damage and epilepsy. This review has summarized the role of ER stress in the pathogenesis of genetic epilepsy.

Association of Oral or Intravenous Vitamin C Supplementation with Mortality: A Systematic Review and Meta-Analysis

Mortality is the most clinically serious outcome, and its prevention remains a constant struggle. This study was to assess whether intravenous or oral vitamin C (Vit-C) therapy is related to reduced mortality in adults. Data from Medline, Embase, and the Cochrane Central Register databases were acquired from their inception to 26 October 2022. All randomized controlled trials (RCTs) involving intravenous or oral Vit-C against a placebo or no therapy for mortality were selected. The primary outcome was all-cause mortality. Secondary outcomes were sepsis, COVID-19, cardiac surgery, noncardiac surgery, cancer, and other mortalities. Forty-four trials with 26540 participants were selected. Although a substantial statistical difference was observed in all-cause mortality between the control and the Vit-C-supplemented groups (p = 0.009, RR 0.87, 95% CI 0.78 to 0.97, I² = 36%), the result was not validated by sequential trial analysis. In the subgroup analysis, mortality was markedly reduced in Vit-C trials with the sepsis patients (p = 0.005, RR 0.74, 95% CI 0.59 to 0.91, I² = 47%), and this result was confirmed by trial sequential analysis. In addition, a substantial statistical difference was revealed in COVID-19 patient mortality between the Vit-C monotherapy and the control groups (p = 0.03, RR 0.84, 95% CI 0.72 to 0.98, I² = 0%). However, the trial sequential analysis suggested the need for more trials to confirm its efficacy. Overall, Vit-C monotherapy does decrease the risk of death by sepsis by 26%. To confirm Vit-C is associated with reduced COVID-19 mortality, additional clinical random control trials are required.

Generation of a TIMP3 knockout stem cell line via CRISPR/Cas9 system

The tissue inhibitors of metalloproteinases 3 (TIMP3) play an essential role in the tumorigenesis of human pancreatic endocrine tumors and Sorsby fundus dystrophy. To further investigate the significance of TIMP3 in disease, we used CRISPR/Cas9 to create a TIMP3 knock out human embryonic stem cell line (WAe009-A-89) that can differentiate into any desired cell type. Our results show that the WAe009-A-89 cell line retains the typical colony form and normal karyotype of stem cells. The cells strongly expressed pluripotency markers and could differentiate into tissues of all three germ layers in vivo. This cell line allowed exploring the role of the TIMP3 gene in related diseases.

Genetic aetiology distribution of 398 foetuses with congenital heart disease in the prenatal setting

AIMS

Copy number variant-sequencing (CNV-seq) and exome sequencing (ES) have been used as powerful tools in understanding the role of genetic variants in congenital heart diseases (CHDs). A few previous large cohort studies have utilized CNV-seq and ES to investigate prenatally diagnosed CHD. Here, we sought to determine the value of CNV-seq and ES for genetic evaluation of foetal CHDs.

METHODS AND RESULTS

We recruited 398 pregnant women diagnosed with CHDs between 8 January 2017 and 30 November 2020. CNV-seq and ES were performed on foetal and parent samples. CHD cases were classified following the guidelines of the International Paediatric and Congenital Cardiac Code and the Tenth and Eleventh Revisions of the International Classification of Diseases. Data on aneuploids (AUP), pathogenic CNVs (pCNVs), and single nucleotide variants (SNVs) were collected and compared, following appropriate procedures. We identified genetic abnormalities in 129 (32.41%) foetuses. These abnormalities included AUP (10.80%), pCNVs (13.32%), and SNVs (8.04%). ES analysis yielded higher SNVs in cases without AUP or pCNVs. Non-isolated CHDs were associated with higher genetic abnormalities than isolated CHDs, mainly due to AUP differences between the two groups. The prevalence of genetic defects was the highest in foetuses with atrioventricular septal defects (AVSD), left ventricular outflow tract obstruction (LVOTO), and conotruncal defects (CTD). AVSD and anomalies of atrioventricular junctions and valves were associated with AUP abnormalities. CTD, anomalies of extrapericardial arterial trunks, and anomalies of the ventricular outflow tracts were the most common CHD categories diagnosed using CNVs. The most common CHDs associated with single ventricle (SV) abnormalities were heterotaxy (Hex) (14.89%), LVOTO (14.58%), and ventricular septal defect (VSD) (26.67%, 4/15). Although the ES yields were higher than CNV-seq for VSD (44.4%, 4/9), LVOTO (20%, 7/35), Hex (14.89%, 7/47), and CTD (9.1%, 11/121), its diagnostic yield did not increase for SV (6.7%, 1/15), AVSD (3.8%, 1/26), or right ventricular obstruction defects (2.6%, 1/38). The most common mutations were observed in KMT2D, CHD7, and NOTCH1.

CONCLUSIONS

To our knowledge, this is the largest cohort study to investigate the incidence of SNVs using ES in foetal CHD. CNV-seq and ES identified genetic abnormalities in nearly 1/3 of foetal CHD cases. Thus, CNV-seq and ES can provide clinically relevant information for pregnancy management.

Houttuynia cordata polysaccharides alleviate ulcerative colitis by restoring intestinal homeostasis

Houttuynia cordata is traditionally used as phytoantibiotics for treating lung disease in China. Houttuynia cordata polysaccharides (HCPs) have been reported to alleviate influenza virus-induced intestinal and lung immune injury by regulating the gut-lung axis. The present study aims to investigate the effects and mechanisms of HCPs on ulcerative colitis (UC). Male C57BL/6 mice were induced by dextran sodium sulfate (DSS) to establish the UC animal model. Our results showed that HCPs significantly reduced the weight loss and the shortening of colon length in colitis mice, and relieved the pathological damage of colon mucosa and inhibited the expression of pro-inflammatory cytokines such as TNF-α, IL-1β, IL-6, etc. It was suggested that HCPs could significantly improve DSS-induced colitis in mice. HCPs directly protected intestinal epithelial cells, ameliorated epithelial barrier dysfunction and cell apoptosis, which was also proved in H₂O₂ stimulated cell apoptosis model. HCPs inhibited inflammation in the colon, which was related to suppressing the infiltration of macrophages, inhibiting the expression of pro-inflammatory cytokines and proteins (TLR4, NF-κB), and restoring the dysfunction of Th17 and Treg cells. HCPs also restored the alteration of intestinal flora induced by DSS, increased the abundance ofFirmicutes and Bacteroides, and reduced the abundance of Proteobacteria. This study confirmed the protective effect of Houttuynia cordata polysaccharide extracted from traditional Chinese medicine on ulcerative colitis, of which the mechanism was closely related to the maintenance of intestinal homeostasis (intestinal barrier, immune cells, and intestinal bacteria).

Genetic abnormalities in fetal congenital heart disease with aberrant right subclavian artery

Fetal aberrant right subclavian artery (ARSA) is a relatively common sonographic finding. Congenital heart disease (CHD) is the most common structural abnormality in patients with ARSA. We aimed to assess the prevalence of genetic abnormalities, particularly sequence variants, in fetuses with CHD and ARSA. By clinical phenotyping and genomic sequencing, we retrospectively reviewed all fetuses with a prenatal diagnosis of CHD combined with ARSA at a single center. As a result, we identified 30 fetuses with ARSA combined with CHD, with conotruncal anomalies being the most common (n = 12, 40%), followed by left ventricular outflow tract obstruction (n = 6, 20%) and atrioventricular septal defects (n = 6, 20%). Overall, 18 (60%) cases had a genetic diagnosis. Copy number variation sequencing analysis identified six (20%) fetuses with aneuploidy and seven (23%) with pathogenic copy-number variants. Whole-exome sequencing (WES) analysis of the remaining 17 cases revealed diagnostic genetic variants in five (29%) cases, indicating that the diagnostic yield of WES for the entire cohort was 17% (5/30). Our findings reveal the high burden of genetic abnormalities in fetal CHD with ARSA. Single-gene disorders contribute substantially to the genetic etiology of fetal CHD with ARSA.

Precisely controlled polydopamine-mediated antibacterial system: mathematical model of polymerization, prediction of antibacterial capacity, and promotion of wound healing

In this work, the polydopamine (PDA)-mediated antibacterial system is synthesized to carry out antimicrobial activities in vitro and in vivo. First, to precisely control the surface modification of nanodiamonds (NDs), a mathematical kinetics model of PDA deposition is established, and the conditions of synthesis reaction are discussed including influencing factors such as the concentrations of dopamine, reaction time, and the kinetic constant k1, which is a function of several variables associated with the reaction temperature, light irradiance (especially at ultraviolet wavelengths), pH value and concentration of dissolved O2 in the solution. A simulated visualization demonstrates that the deposition thickness of PDA is positively correlated with temperature and light irradiance, and PDA is easier to deposit in an alkaline solution and will be terminated if the dissolved O2 is insufficient. Then, the precisely controlled thickness of PDA can control the growth of AgNPs, rendering the intensity of Raman peaks increased and providing a predictable antibacterial effect against E. coli in vitro. An optimized antibacterial hydrogel containing NDs-PDA/Ag is prepared and characterized by the Fourier transform infrared spectroscopy and field emission scanning electron microscopy. Finally, the antibacterial experiments to promote wound healing in vivo are performed, which are verified by pathological and immunohistochemical-stained sections. This work provides a theoretical basis of predicting the PDA-assisted surface modification of NDs, giving a divinable antibacterial effect, and promoting wounds healing in vivo.

Tumor microenvironment responsive Mn3O4 nanoplatform for in vivo real-time monitoring of drug resistance and photothermal/chemodynamic synergistic therapy of gastric cancer

Background

Postoperative chemotherapy for gastric cancer often causes multidrug resistance (MDR), which has serious consequences for therapeutic effects. Individualized treatment based on accurate monitoring of MDR will greatly improve patient survival.

Results

In this article, a self-enhanced Mn₃O₄ nanoplatform (MPG NPs) was established, which can react with glutathione to produce Mn²⁺ to enhance T1-weighted magnetic resonance imaging (MRI) and mediate in vivo real-time MDR monitoring. In vitro MRI results showed that MRI signals could be enhanced in the presence of hydrogen peroxide and glutathione and at acidic pH. In vivo MRI results indicated that MPG NPs could specifically target MDR cells, thereby realizing real-time monitoring of MDR in gastric cancer. Furthermore, MPG NPs have good chemodynamic activity, which can convert the endogenous hydrogen peroxide of tumor cells into highly toxic hydroxyl radical through Fenton-like reaction at acidic pH to play the role of chemodynamic therapy. In addition, Mn₃O₄ can significantly enhance the chemodynamic therapy effect because of its good photothermal conversion effect. Furthermore, in situ photothermal/chemodynamic synergistic therapy obtained remarkable results, the tumors of the mice in the synergistic therapy group gradually became smaller or even disappeared.

Conclusions

MPG NPs have good biocompatibility, providing a good nanoplatform for real-time monitoring and precise diagnosis and treatment of MDR in gastric cancer.

Graphical Abstract

Supplementary information

The online version contains supplementary material available at 10.1186/s12951-022-01441-6.

Genetic and Clinical Features of Heterotaxy in a Prenatal Cohort

Objectives: Some genetic causes of heterotaxy have been identified in a small number of heterotaxy familial cases or animal models. However, knowledge on the genetic causes of heterotaxy in the fetal population remains scarce. Here, we aimed to investigate the clinical characteristics and genetic spectrum of a fetal cohort with heterotaxy.

Methods: We retrospectively investigated all fetuses with a prenatal diagnosis of heterotaxy at a single center between October 2015 and November 2020. These cases were studied using the genetic testing data acquired from a combination of copy number variation sequencing (CNV-seq) and whole-exome sequencing (WES), and their clinical phenotypes were also reviewed.

Result: A total of 72 fetuses diagnosed with heterotaxy and complete clinical and genetic results were enrolled in our research. Of the 72 fetuses, 18 (25%) and 54 (75%) had left and right isomerism, respectively. Consistent with the results of a previous study, intracardiac anomalies were more severe in patients with right atrial isomerism than in those with left atrial isomerism (LAI) and mainly manifested as atrial situs inversus, bilateral right atrial appendages, abnormal pulmonary venous connection, single ventricles or single atria, and pulmonary stenosis or atresia. In 18 fetuses diagnosed with LAI, the main intracardiac anomalies were bilateral left atrial appendages. Of the 72 fetuses that underwent CNV-seq and WES, 11 (15.3%) had positive genetic results, eight had definitive pathogenic variants, and three had likely pathogenic variants. The diagnostic genetic variant rate identified using WES was 11.1% (8/72), in which primary ciliary dyskinesia (PCD)-associated gene mutations (CCDC40, CCDC114, DNAH5, DNAH11, and ARMC4) accounted for the vast majority (n = 5). Other diagnostic genetic variants, such as KMT2D and FOXC1, have been rarely reported in heterotaxy cases, although they have been verified to play roles in congenital heart disease.

Conclusion: Thus, diagnostic genetic variants contributed to a substantial fraction in the etiology of fetal heterotaxy. PCD mutations accounted for approximately 6.9% of heterotaxy cases in our fetal cohort. WES was identified as an effective tool to detect genetic causes prenatally in heterotaxy patients.

Active Extrinsic Calibration of Encoder and LIDAR for Robot

Robotic extrinsic calibration is a prerequisite for multi-sensor data fusion, which provides a transformation between coordinate systems of different sensors. For wheeled robots equipped with encoder and other sensors, the existing usual calibration process is completed by professional calibration engineers, or just randomly, which is not efficient and may cause motion degradation or unknown uncertainty. In this paper, we propose an active extrinsic calibration algorithm for encoder and 2D LIDAR. The trajectory in the calibration process is planned in belief space, which is optimized to get the calibration value with the minimized uncertainty. Our method doesn’t rely on maximum-likelihood observations assumption, and can also work in discontinuous sensing domain. The simulation is conducted to validate the method.

Circular Ribonucleic Acid Expression Alteration in the Spinal Cord Tissue after Spinal Cord Injury in Rats

BACKGROUND AND PURPOSE

Increased researches focus into pathophysiological mechanisms of spinal cord injury (SCI), particularly toward the relationship between relevant biomarkers and the degree of SCI and prognosis. Circular ribonucleic acids (circRNAs) possess microRNA (miRNA) binding sites that can play the role of miRNA sponges and thus participate in the expression of parental gene modification. This study focused on rat SCI models and explore the relationship between circRNAs and SCI at a genomic level.

METHODS

We first established a rat SCI model and extracted the target spinal cord tissue according to 4 time points. Then investigated the alterations in the circRNA expression by high-throughput whole transcriptome sequencing, analyzed data by gene ontology and the Kyoto Encyclopedia of Genes and Genomes, and constructed the circRNA-miRNA network.

RESULTS

A total of 178 circRNAs were dysregulated (89 upregulated/89 downregulated). Differential circRNAs were found to be mainly involved in the composition of specific organelles in the cytoplasm and are mainly involved in the energy transfer process associated with electron transfer (and similar activities). In all the signaling pathways identified in this study, the MAPK, Wnt, and mTOR signaling pathways are intimately associated with the pathophysiological process of rats post-SCI. In this study, 10 circRNAs with obvious dysregulation were selected for prediction, 26 miRNAs with additional interactions were obtained, and a network diagram of circRNAs-miRNAs was constructed. In this manner, one can understand in further detail the pathogenesis of SCI and to provide new strategies for the prevention, diagnosis, and treatment of SCI-related injuries at the genetic level.

Cerebral Microbleed Burden in Ischemic Stroke Patients on Aspirin: Prospective Cohort of Intracranial Hemorrhage

Objective: This investigation aimed at studying the prevalence of cerebral microbleeds (CMBs), including risk factors and the correlation of CMBs to ischemic stroke (IS) patient end results.

Methods: Four hundred and fifty-nine acute IS cases were recruited between April 2014 and December 2016. Cerebral microbleeds were analyzed using susceptibility-weighted imaging (SWI) brain MRI scan. The enrolled patients with acute IS were followed up for 12–24 months, with a median follow-up time of 19 months. The follow-up endpoint events including recurrent ischemic stroke (RIS), intracranial hemorrhage (ICH), transient ischemic attack (TIA), mortality, and cardiovascular events. The associations between vascular risk factors and CMBs in IS patients were analyzed using univariate and multivariate logistic regression analysis. Cox regression model was employed for evaluating CMB impact on clinical outcome.

Results: Among 459 enrolled patients, 187 (40.7%) had CMBs and 272 (59.2%) had no CMB. In comparison with patients with no CMBs, age was higher and hypertension was more frequent in patients with CMBs. Multivariate logistic regression analyses revealed age and hypertension were independently associated with the presence of CMBs. Among the patient cohort, 450 cases completed the follow-up. During the follow-up period, 22 (4.9%) of patients developed ICH, 12 (2.7%) developed TIA, 68 (15.1%) developed RIS, cardiovascular events occurred in 20 (4.44%), and 13 (2.89%) cases were mortalities. Compared with patients without CMBs, IS patients with CMBs have an increased prevalence of ICH (p < 0.05). However, no statistically valid variations regarding other outcome incidences between both groups was identified (p > 0.05). The incidence of ICH was elevated in tandem with elevations in number of CMBs. Following adjusting for age, multivariate Cox proportional-hazards regression analysis revealed that CMBs ≥10 were independent predictors of ICH in acute IS patients.

Conclusion: Age and hypertension are independently associated with the presence of CMBs. Intracranial hemorrhage incidence rate was increased with the number of CMBs, and the number of CMBs ≥10 were independent predictors of ICH in acute stroke patients.

1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) Urea Exerts Neuro-Protective Effects Against Ischemic Injury via Suppressing JNK/p38 MAPK-Mediated Mitochondrial Apoptosis Pathway

BACKGROUND

1-trifluoromethoxyphenyl-3-(1- propionylpiperidin-4-yl) urea (TPPU) is a novel soluble epoxide hydrolase inhibitor which can protect against cerebral ischemic injury in middle cerebral artery occlusion rat model. However, the effects and potential mechanisms of TPPU on mitochondrial dysfunction are poorly understood.

MATERIALS AND METHODS

In oxygen-glucose deprivation/reperfusion (OGD/R)-induced cortical neurons, the effect of TPPU on cell viability was measured by MTT assay and apoptosis was evaluated using TUNEL assay. Mitochondria were observed by transmission electron microscopy and Mitotracker green staining assay, mitochondrial membrane potential was determined by JC-1 staining assay, activities of mitochondrial respiratory chain complexes (MRCC) I-IV and ATPase were measured by MRCC Activity Assay Kits and spectrophotometer. Western blot was used to investigate the effects of TPPU on apoptosis-related proteins.

RESULTS

TPPU treatment demonstrated significant protective effect on the OGD/R-induced cortical neurons by reducing cell death and number of apoptotic cells, stabilizing mitochondrial ultrastructure and morphology, increasing mitochondrial membrane potential and activities of MRCC I-IV and ATPase. Furthermore, TPPU treatment might effectively reverse the upregulation of caspase-3, Bax, p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal protein kinase (JNK), alleviate the inhibition of Bcl-2 in OGD/R-induced cortical neurons.

CONCLUSIONS

TPPU exerts a marked neuroprotective effect against mitochondrial dysfunction after cerebral ischemia potentially via suppressing JNK/p38 MAPK-mediated mitochondrial apoptosis signal pathway, it may be a promising neuroprotective agent for cerebral ischemia.

Selective optogenetic stimulation of glutamatergic, but not GABAergic, vestibular nuclei neurons induces immediate and reversible postural imbalance in mice

Glutamatergic and GABAergic neurons represent the neural components of the medial vestibular nuclei. We assessed the functional role of glutamatergic and GABAergic neuronal pathways arising from the vestibular nuclei (VN) in the maintenance of gait and balance by optogenetically stimulating the VN in VGluT2-cre and GAD2-cre mice. We demonstrate that glutamatergic, but not GABAergic VN neuronal subpopulation is responsible for immediate and strong posturo-locomotor deficits, comparable to unilateral vestibular deafferentation models. During optogenetic stimulation, the support surface dramatically increased in VN^VGluT2+ mice, and rapidly fell back to baseline after stimulation, whilst it remained unchanged during similar stimulation of VN^GAD2+ mice. This effect persisted when vestibular tactilo kinesthesic plantar inputs were removed. Posturo-locomotor alterations evoked in VN^VGluT2+ animals were still present immediately after stimulation, while they disappeared 1 h later. Overall, these results indicate a fundamental role for VN^VGluT2+ neurons in balance and posturo-locomotor functions, but not for VN^GAD2+ neurons, in this specific context. This new optogenetic approach will be useful to characterize the role of the different VN neuronal populations involved in vestibular physiology and pathophysiology.

Improved privacy preserving method for periodical SRS publishing

Spontaneous reporting systems (SRSs) are used to collect adverse drug events (ADEs) for their evaluation and analysis. Periodical SRS data publication gives rise to a problem where sensitive, private data can be discovered through various attacks. The existing SRS data publishing methods are vulnerable to Medicine Discontinuation Attack(MD-attack) and Substantial symptoms-attack(SS-attack). To remedy this problem, an improved periodical SRS data publishing-PPMS(k, θ, ɑ)-bounding is proposed. This new method can recognize MD-attack by ensuring that each equivalence group contains at least k new medicine discontinuation records. The SS-attack can be thwarted using a heuristic algorithm. Theoretical analysis indicates that PPMS(k, θ, ɑ)-bounding can thwart the above-mentioned attacks. The experimental results also demonstrate that PPMS(k, θ, ɑ)-bounding can provide much better protection for privacy than the existing method and the new method dose not increase the information loss. PPMS(k, θ, ɑ)-bounding can improve the privacy, guaranteeing the information usability of the released tables.

Genetics and Clinical Features of Noncompaction Cardiomyopathy in the Fetal Population

Objectives: Noncompaction Cardiomyopathy (NCCM) has been classified as primary genetic cardiomyopathy and has gained increasing clinical awareness; however, little is known about NCCM in the fetal population. We aimed to investigate the clinical characteristics and genetic spectrum of a fetal population with NCCM. Methods: We retrospectively reviewed all fetuses with a prenatal diagnosis of NCCM at a single center between October 2010 and December 2019. These cases were investigated for gestational age at diagnosis, gender, left or biventricular involvement, associated cardiac phenotypes, outcomes, and genetic testing data. Results: We identified 37 fetuses with NCCM out of 49,898 fetuses, indicating that the incidence of NCCM in the fetal population was 0.07%. Of the 37 fetuses, 26 were male, ten were female and one was of unknown gender. NCCM involvement biventricle is the most common (n = 16, 43%), followed by confined to the left ventricle (n = 14, 38%). Nineteen (51%) had additional congenital heart defects, with right-sided lesions being the most common (n = 14, 74%), followed by ventricular septal defects (n = 10, 53%). Hydrops fetalis was present in 12 cases (32%), of which four were atypical (pericardial effusion only). Sequencing analysis was performed at autopsy (n = 19) or postnatally (n = 1) on 20 fetuses. Of the 20 fetuses undergoing copy number variation sequencing and whole-exome sequencing, nine (47%) had positive genetic results, including one with a pathogenic copy number variant and eight with pathogenic/likely pathogenic variants. Non-sarcomere gene mutations accounted for the vast majority (n = 7). In contrast, sarcomere gene mutations occurred in only one case (TPM1), and no mutations were identified in the three most common sarcomere genes (MYH7, TTN, and MYBPC3) of pediatric and adult patients. Pathogenic/likely pathogenic variants were significantly more frequent in fetuses with congenital heart defects than those without congenital heart defects. Conclusions: Our data demonstrate that fetal NCCM is a unique entity. Compared with pediatric and adult NCCM, fetal NCCM is more prone to biventricle involvement, more likely to be complicated with congenital heart defects, and has a distinct genetic spectrum.

Mobilization of recalcitrant phosphorous and enhancement of pepper P uptake and yield by a new biocontrol and bioremediation bacterium Burkholderia cepacia CQ18

AIMS

Phosphorus (P) is a finite resource and inoculation of phosphorus-mobilizing bacteria (PMB) is a promising approach for the enhancement of soil P availability and plant P uptake. This drives scientists to search for the microbes effective in mobilizing legacy P in soils.

METHODS AND RESULTS

The current incubation and greenhouse pot experiments were conducted to investigate P mobilization and pepper P uptake as affected by a new biocontrol and bioremediation bacterium Burkholderia cepacia CQ18. This bacterium converted Ca₃ (PO₄ )₂ , FePO₄ , AlPO₄ , and lecithin into soluble inorganic P in the culture solutions and increased available P (including water-soluble P and Olsen P) in the soil. There were positive correlations between the soluble inorganic phosphorus and the exudates (protons, organic acids (oxalate and gluconate), siderophores and phosphatases) in culture solutions. Pepper plant biomass, fruit yield and P uptake changed in the sequence: chemical fertilizers plus bacterial inoculant >only chemical fertilizers >only bacterial inoculant >blank control.

CONCLUSIONS

Taking into account the wide spectrums of P mobilization and simultaneous production of acid, neutral and alkaline phosphatases at a given pH, B.cepacia CQ18 may be a potential PMB used in soils with wide pH ranges. The mechanisms employed by this bacterium in the solubilization of recalcitrant inorganic P could be the efflux of protons, organic acids (oxalate and gluconate) and siderophores. Phosphatases could be of utmost importance in the mineralization of the organic P. The production of siderophores and phosphatases by of B.cepacia CQ18 could thus be crucial for not only the antagonism against plant pathogens but also the mobilization of soil sparingly available P.

SIGNIFICANCE AND IMPACT OF THE STUDY

Burkholderia cepacia CQ18 could be potentially developed into a biofertilizer.

Contribution of single-gene defects to congenital cardiac left-sided lesions in the prenatal setting

OBJECTIVES

To explore the contribution of single-gene defects to the genetic cause of cardiac left-sided lesions (LSLs), and to evaluate the incremental diagnostic yield of whole-exome sequencing (WES) for single-gene defects in fetuses with LSLs without aneuploidy or a pathogenic copy-number variant (pCNV).

METHODS

Between 10 April 2015 and 30 October 2018, we recruited 80 pregnant women diagnosed with a LSL who had termination of pregnancy and genetic testing. Eligible LSLs were aortic valve atresia or stenosis, coarctation of the aorta, mitral atresia or stenosis and hypoplastic left heart syndrome (HLHS). CNV sequencing (CNV-seq) and WES were performed sequentially on specimens from these fetuses and their parents. CNV-seq was used to identify aneuploidies and pCNVs, while WES was used to identify diagnostic genetic variants in cases without aneuploidy or pCNV.

RESULTS

Of 80 pregnancies included in the study, 27 (33.8%) had a genetic diagnosis. CNV-seq analysis identified six (7.5%) fetuses with aneuploidy and eight (10.0%) with pCNVs. WES analysis of the remaining 66 cases revealed diagnostic genetic variants in 13 (19.7%) cases, indicating that the diagnostic yield of WES for the entire cohort was 16.3% (13/80). KMT2D was the most frequently mutated gene (7/66 (10.6%)) in fetuses with LSL without aneuploidy or pCNVs, followed by NOTCH1 (4/66 (6.1%)). HLHS was the most prevalent cardiac phenotype (4/7) in cases with a KMT2D mutation in this cohort. An additional six (9.1%) cases were found to have potentially deleterious variants in candidate genes.

CONCLUSIONS

Single-gene defects contribute substantially to the genetic etiology of fetal LSLs. KMT2D mutations accounted for approximately 10% of LSLs in our fetal cohort. WES has the potential to provide genetic diagnoses in fetuses with LSLs without aneuploidy or pCNVs. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Generation of a NONO homozygous knockout human induced pluripotent stem cell line by CRISPR/Cas9 editing

The non-POU domain containing octamer-binding gene (NONO) encodes a member of a small family of RNA-binding and DNA-binding proteins, whose variants can cause intellectual disability and congenital heart defects. In this study, we generated a homozygous NONO knockout (NONO-KO) induced pluripotent stem cell (iPSC) line (CMUi002-A-1) using the CRISPR/Cas9-based genome editing system. The gene-edited line had a normal karyotype, expressed pluripotency markers, and was able to differentiate into all three germ layers in vivo. This cell line will provide a platform to study the pathogenic mechanisms of noncompaction cardiomyopathy and neurocyte dysfunction related to NONO mutations.

[Risk factors of anastomotic leakage after robotic surgery for low and mid rectal cancer]

Objective: To investigate the risk factors associated with anastomotic leakage after robotic surgery in mid-low rectal cancer. Methods: A retrospective case-control study method was conducted. Inclusion criteria: (1) 18 to 80 years old; (2) pathologically confirmed rectal cancer; (3) distance <10 cm from tumor to anal margin; (4) robotic anterior rectal resection. Patients with previous history of colorectal cancer surgery, distant metastases or other malignant tumors, undergoing emergency surgery, with severe abdominal adhesions or those receiving combined organ resection were excluded. Based on the above criteria, 636 patients undergoing robotic radical sphincter-preserving surgery for mid-low rectal cancer in Zhongshan Hospital from January 2015 to December 2018 were included in this study, including 398 males (62.6%) and 238 females (37.4%) with a mean age of (61.9±11.3) years. Sixty-eight cases (10.7%) received neoadjuvant chemoradiotherapy. Amony the 636 included patients, 123(19.3%) underwent natural orifice specimen extraction surgery (NOSES) and 15 (2.3%) underwent preventive stoma. According to the cirteria developed by the International Rectal Cancer Research Group in 2010, the anastomotic leakage was classified as grade A (no requirement of intervention), B (requirement of intervention), and C (requirement of operation). Logistic regression was used to analyze the relationship between anastomotic leakage and clinicopathological factors. Factors in univariate analysis with P<0.05 were included in the multivariate analysis. Results: Anastomotic leakage occurred in 38 cases (6.0%). The grading of anastomotic leakage was grade A in 13 cases (2.0%), grade B in 19 cases (3.0%), and grade C in 6 cases (0.9%). The 3-year disease-free survival rate of patients with anastomotic leakage and without anastomotic leakage was 83.5% and 83.6% respectively (P=0.862); the 3-year overall survival rate of the two group was 85.1% and 87.5% respectively (P=0.296). The results of univariate logistic regression analysis showed that male (P=0.011), longer operation time (P=0.042), distance ≤5 cm from tumor to anal margin (P=0.012), more intraoperative blood loss (P=0.048) were associated with anastomotic leakage (all P<0.05). NOSES was not associated with anastomotic leakage (P=0.704). Multivariate analysis confirmed that male (OR=3.03, 95%CI: 1.37 to 7.14, P=0.010), operation time ≥180 minutes (OR=2.04, 95%CI: 1.03 to 3.99, P=0.040), distance ≤5 cm from tumor to anal margin (OR=2.56, 95%CI:1.28 to 5.26, P=0.008) were independent risk factors for anastomotic leakage. Conclusion: Male, short distance from tumor to anal margin, and long operation time are independent risk factors for anastomotic leakage in patients undergoing robotic mid-low rectal cancer radical surgeries. These patients need to be cautiously treated during surgery.

Effects of quorum quenching on temporal succession of activated sludge microbial community in a membrane bioreactor

AIMS

Quorum quenching (QQ) is an attractive strategy for mitigating biofouling in membrane bioreactors (MBRs). However, the effects of QQ on the activated sludge (AS) process have not been adequately evaluated. This study investigated the long-term effects of QQ on a laboratory-scale anoxic-oxic MBR, focusing on AS performance and microbial community.

METHODS AND RESULTS

Anoxic-oxic MBRs with and without QQ were operated for 91 days. QQ did not affect COD and TN removal efficiencies over the experimental period, during which its activity remained >90%. QQ reduced floc size by approximately 8% but had no effect on biomass concentration. AS microbial communities were regularly analysed using massively parallel sequencing. AS bacterial communities were temporally dynamic irrespective of QQ presence, for example, a temporal increase in bacterial diversity and a temporal decay of community similarity. QQ counteracted the temporal change in diversity and the temporal distance-community decay. Community comparison revealed that QQ changed the successional trajectory of the AS community at a late period, because it decelerated temporal changes of specific members, such as Thiothrix and Sphingomonadaceae*. Correlation networks revealed that QQ increased network clustering, complexity and density. The combined results suggest that the tighter microbial association by QQ increased the community resistance.

CONCLUSIONS

QQ can enhance the diversity and stability of the AS community in MBR by counteracting the innate temporal change in community structure.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our findings are useful for the further advancement of QQ-based strategies in engineered microbial environments.

P4649Whole exome sequencing and whole genome sequencing improves genetic diagnosis of fetals with heterotaxy syndrome revealed by prenatal ultrasound

Background

Heterotaxy (Htx) syndrome is an congenital disorders resulting from incorrectly establishment of left-right patterning during embryogenesis. Over 96% of patients with Htx exhibit some form of congenital heart disease (CHD),and has relatively poor survival. Multiple lines of evidence support genetic contributions to the etiology of Htx. As a specific genetic etiology is currently identifiable in only a minority of patients, there remains enormous potential for novel gene and pathway discovery.

Purpose

The aim of this study was to investigate the diagnostic yield of whole-exome sequencing (WES) and whole-genome sequencing (WGS) in fetuses with the pathogenesis of Htx, to explore candidate genes for Htx and to expand the clinical phenotype of known genetic conditions.

Method

WES and WGS were performed on specimens from 46 fetuses diagnosed with Htx and their parents. The single-nucleotide variants (SNVs) and copy-number variants (CNVs) were filtered and annotated by standard analysis process. All reported variants were classified according to he American College of Medical Genetics and Genomics guidelines.

Results

In the 46 fetuses, the detection rates of pathogenic and likely pathogenic variations were21.7% (10/46) and 10.9% (5/46) respectively. Ten pathogenic variations were identified on genes of CCDC114, DNAH11, ARMC4, STRA6, PQBP1 (hemizygote), HYDIN, RAI1 (Alagille Syndrome), ZFMP2 and Del(22q11.2) Syndrome. Five likely pathogenic variation were on DNAAF1 (Holshner syndrome), NF1, NEXN, NOTCH3 and FOXC1. Of 30 fetuses with prenatally diagnosed right atrial isomerism (RAI), the main intracardiac anomalies were atrioventricular canal (AV canal), isomerism of right atrial appendages, pulmonary stenosis or atresia (PS & PA) and right aortic arch. In 16 fetuses diagnosed left atrial isomerism (LAI) the main intracardiac anomalies were isomerism of left atrial appendages, interrupted IVC and azygos vein continuation. Of the 10 positive cases, 8 fetus were diagnosed of RAI and 2 were diagnosed of LAI by prenatal ultrasonic examination or fetal autopsy. The detection rate was 8/30 (26.7%) for RAI and 2/16 (12.5%) for LAI.

Conclusion

This study outlines the way for a substantial improvement in the diagnostic yield of prenatal genetic disorders in Htx through WES and WGS. Our experience also expanded the knowledge of the clinical phenotype of known genetic conditions. Our results indicate that the proportion of SNV in Htx of prenatal cases was significantly higher than that in patients with other congenital heart abnormalities, and the recessive inheritance occurred in a higher proportion in Htx. Our results have important implications for clinical management and genetic counseling of Htx.

Acknowledgement/Funding

Ministry of Science and Technology of the People's Republic of China

P4647Next generation sequencing in 83 fetal left-sided CHDs reveals the entire genetic architecture of left-sided CHDs in fetal population

Background

No data is available for the contribution of single gene disorders (SGDs) to left-sided congenital heart defects (LSCHDs) in the fetal population.

Purpose

The aim of this study was to explore the entire genetic architecture of LSCHDs, especially the contribution of SGDs in a cohort of fetal LSCHDs.

Methods

Low-pass whole genome sequencing (WGS) and whole exome sequencing (WES) were performed on specimens from 83 deceased fetuses with lSCHDs, including 48 HLHS, 22 CoA, 5 AS, 3 AAH, 2 AS+CoA and 1 case of AA, AS+MS, MA. Sequencing was predominantly performed in fetus-parent trios (n=63, 75.9%), or in fetus only (n=20, 24.1%).

Results

34.9% (n=29) of the 83 fetal left-sided CHDs were identified with related genetic abnormalities. WGS analysis identified 14 (16.9%) with chromosomal abnormalities, including 6 (7.2%) aneuploidies and 8 (9.6%) pathogenic copy number variants (CNVs). WES analysis of the remaining 69 cases without chromosomal abnormalities identified 15 (15/69, 21.7%) with pathogenic/likely pathogenic variants. Of these 15 cases, KMT2D was the most frequently mutated gene (7/69, 10.1%), followed by NOTCH1 (4/69, 2.5%). Compound heterozygosity was identified in 3 genes (DNAH11, POFUT1, CRB2) that are not yet well established as CHD genes. Finally, we also observed a LOF variant in NONO (X-linked) that was maternally transmitted to an affected male case.

The genetic results of this cohort Aneuploidies Trisomy 18 4 Turner syndrome 2 CNVs 11q terminal deletion 3 1p36 deletion 1 15q terminal deletion 1 7q11.23 deletion 1 4p terminal deletion 1 12q complex internal duplication 1 SGDs AD (KMT2D = 7; NOTCH1 = 4) 11 AR (DNAH11, POFUT1, CRB2) 3 X-recessive (NONO) 1 AD: autosomal dominant; AR: autosomal recessive.

Conclusions

Our experience supports that SGDs contribute a significant part to the pathogenesis of fetal CHDs, WES has the potential to provide molecular diagnoses in fetal left-sided CHDs without chromosomal abnormalities. KMT2D mutations accounted for a large fraction of left-sided CHDs in fetal population. If the KMT2D mutation is detected, further diagnosis of Kabuki syndrome should be considered.

Known-component metal artifact reduction (KC-MAR) for cone-beam CT

Intraoperative cone-beam CT (CBCT) is increasingly used for surgical navigation and validation of device placement. In spinal deformity correction, CBCT provides visualization of pedicle screws and fixation rods in relation to adjacent anatomy. This work reports and evaluates a method that uses prior information regarding such surgical instrumentation for improved metal artifact reduction (MAR). The known-component MAR (KC-MAR) approach achieves precise localization of instrumentation in projection images using rigid or deformable 3D-2D registration of component models, thereby overcoming residual errors associated with segmentation-based methods. Projection data containing metal components are processed via 2D inpainting of the detector signal, followed by 3D filtered back-projection (FBP). Phantom studies were performed to identify nominal algorithm parameters and quantitatively investigate performance over a range of component material composition and size. A cadaver study emulating screw and rod placement in spinal deformity correction was conducted to evaluate performance under realistic clinical imaging conditions. KC-MAR demonstrated reduction in artifacts (standard deviation in voxel values) across a range of component types and dose levels, reducing the artifact to 5-10 HU. Accurate component delineation was demonstrated for rigid (screw) and deformable (rod) models with sub-mm registration errors, and a single-pixel dilation of the projected components was found to compensate for partial-volume effects. Artifacts associated with spine screws and rods were reduced by 40%-80% in cadaver studies, and the resulting images demonstrated markedly improved visualization of instrumentation (e.g. screw threads) within cortical margins. The KC-MAR algorithm combines knowledge of surgical instrumentation with 3D image reconstruction in a manner that overcomes potential pitfalls of segmentation. The approach is compatible with FBP-thereby maintaining simplicity in a manner that is consistent with surgical workflow-or more sophisticated model-based reconstruction methods that could further improve image quality and/or help reduce radiation dose.

Impact of Time Interval Between Glenn and Fontan Procedures on Fontan Operative and Long-Term Follow-up Results

OBJECTIVE

The bidirectional cavopulmonary shunt (BCPS) is an effective palliative procedure which has been widely used to boost outcome of the Fontan procedure. However, there is no standard duration time between these two procedures. Therefore, we investigated whether different time intervals between BCPS and Fontan procedure affects morbidity and mortality of Fontan patients.

METHODS

Between 2004 and 2016, 210 post-BCPS patients underwent Fontan operation at Fuwai Hospital. The median interval between BCPS and Fontan procedure was 3.7 years (range 0.55-11.86 years) and this was used to divide study cohort into Group 1 (< 3.7 years; n = 124) and Group 2 (> 3.7 years; n = 86). We analyzed these patients retrospectively in terms of their preoperative characteristics and post-operative and follow-up results.

RESULTS

Weight z-scores for age at BCPS (- 0.73 ± 1.39 vs - 1.17 ± 1.60, p < 0.05) was significantly higher in Group 2. However, saturation at room air before Fontan (76.42 ± 20.01 vs 82.85 ± 9.69, p < 0.001) was significantly higher in Group 1. The morbidity and mortality were similar between two groups. There were twelve hospital deaths (5.7%): eight (8/124, 6.5%) presented in Group 1 and four (4/86, 4.7%) in Group 2. On multi-variable analysis, risk factors for death were prolonged mechanical ventilation [hazard ratio (HR) 1.02, p = 0.004] and single right ventricle (HR 7.17, p = 0.03). After a mean follow-up of 4.95 years (range 0.74-13.62 years), one patient in Group 1 died of heart failure 13 months after Fontan procedure. The overall Fontan failure in Group 1 was similar to that in Group 2 (2.7% vs 2.6%, p = 0.985). The incidence of arrhythmias and re-intervention were not different between the two groups.

CONCLUSIONS

Fontan procedure could be performed safely in patient who stayed in long duration between Fontan procedure and BCPS without affecting the operative and long-term follow-up results. However, for post-BCPS patients with severe hypoxemia, earlier age at Fontan might be a good choice.

Image quality and dose characteristics for an O-arm intraoperative imaging system with model-based image reconstruction

PURPOSE

To assess the imaging performance and radiation dose characteristics of the O-arm CBCT imaging system (Medtronic Inc., Littleton MA) and demonstrate the potential for improved image quality and reduced dose via model-based image reconstruction (MBIR).

METHODS

Two main studies were performed to investigate previously unreported characteristics of the O-arm system. First is an investigation of dose and 3D image quality achieved with filtered back-projection (FBP) - including enhancements in geometric calibration, handling of lateral truncation and detector saturation, and incorporation of an isotropic apodization filter. Second is implementation of an MBIR algorithm based on Huber-penalized likelihood estimation (PLH) and investigation of image quality improvement at reduced dose. Each study involved measurements in quantitative phantoms as a basis for analysis of contrast-to-noise ratio and spatial resolution as well as imaging of a human cadaver to test the findings under realistic imaging conditions.

RESULTS

View-dependent calibration of system geometry improved the accuracy of reconstruction as quantified by the full-width at half maximum of the point-spread function - from 0.80 to 0.65 mm - and yielded subtle but perceptible improvement in high-contrast detail of bone (e.g., temporal bone). Standard technique protocols for the head and body imparted absorbed dose of 16 and 18 mGy, respectively. For low-to-medium contrast (<100 HU) imaging at fixed spatial resolution (1.3 mm edge-spread function) and fixed dose (6.7 mGy), PLH improved CNR over FBP by +48% in the head and +35% in the body. Evaluation at different dose levels demonstrated 30% increase in CNR at 62% of the dose in the head and 90% increase in CNR at 50% dose in the body.

CONCLUSIONS

A variety of improvements in FBP implementation (geometric calibration, truncation and saturation effects, and isotropic apodization) offer the potential for improved image quality and reduced radiation dose on the O-arm system. Further gains are possible with MBIR, including improved soft-tissue visualization, low-dose imaging protocols, and extension to methods that naturally incorporate prior information of patient anatomy and/or surgical instrumentation.

Long-term efficacy and safety of sonidegib in patients with locally advanced and metastatic basal cell carcinoma: 30-month analysis of the randomized phase 2 BOLT study

BACKGROUND

Patients with locally advanced basal cell carcinoma (laBCC) or metastatic BCC (mBCC), two difficult-to-treat populations, have had limited treatment options. Sonidegib, a hedgehog pathway inhibitor (HPI), was approved in laBCC based on results from the BOLT trial.

OBJECTIVE

To evaluate long-term efficacy and safety of sonidegib in laBCC and mBCC in the BOLT 18- and 30-month analyses.

METHODS

BOLT (NCT01327053, ClinicalTrials.gov), a double-blind phase 2 study, enrolled patients from July 2011 until January 2013. Eligible HPI-treatment-naïve patients with laBCC not amenable to curative surgery/radiotherapy or mBCC were randomized 1 : 2 to sonidegib 200 mg (laBCC, n = 66; mBCC, n = 13) or 800 mg (laBCC, n = 128; mBCC, n = 23). Tumour response was assessed per central and investigator review.

RESULTS

With 30 months of follow-up, among patients treated with sonidegib 200 mg (approved dose), objective response rates were 56.1% (central) and 71.2% (investigator) in laBCC and 7.7% (central) and 23.1% (investigator) in mBCC. Tumour responses were durable as follows: median duration of response was 26.1 months (central) and 15.7 months (investigator) in laBCC and 24.0 months (central) and 18.1 months (investigator) in mBCC. Five patients with laBCC and three with mBCC in the 200-mg arm died. Median overall survival was not reached in either population; 2-year overall survival rates were 93.2% (laBCC) and 69.3% (mBCC). In laBCC, efficacy was similar regardless of aggressive or non-aggressive histology. Sonidegib 200 mg continued to have a better safety profile than 800 mg, with lower rates of grade 3/4 adverse events (43.0% vs. 64.0%) and adverse events leading to discontinuation (30.4% vs. 40.0%).

CONCLUSION

Sonidegib continued to demonstrate long-term efficacy and safety in these populations. These data support the use of sonidegib 200 mg per local treatment guidelines.

Technical Note: Known-Component Registration for Robotic Drill Guide Positioning

A method for x-ray-guided robotic positioning of surgical instruments is reported and evaluated in preclinical studies of spine pedicle screw placement with the aim of improving delivery of transpedicle drills and screws. The known-component registration (KC-Reg) algorithm was used to register the 3D patient CT and the surface model of a drill guide to intraoperatively acquired 2D radiographs. Resulting transformations, combined with offline hand-eye calibration, drive a robotically-held drill guide to target trajectories established in the preoperative patient CT. The proposed method was assessed against more conventional surgical tracker guidance, and robustness to clinically realistic errors was tested in phantom and cadaver studies. Target registration error (TRE) was computed as drill guide deviation from the planned trajectory. The KC-Reg approach resulted in 1.51 ± 0.51 mm error at tooltip and 1.01 ± 0.92° in approach angle, showing comparable performance to the tracker-guided approach. In cadaver studies with anatomical deformation, TRE of 2.31 ± 1.05 mm and 0.66 ± 0.62° were observed, with statistically improved performance over a surgical tracker through registration of locally rigid bony anatomy. X-ray guidance offers an accurate means of driving robotic systems that is compatible with conventional fluoroscopic workflow. Specifically, such procedures involve multi-planar fluoroscopic views that are qualitatively interpreted by the surgeon; the KC-Reg approach accomplishes this using the same multi-planar views to provide greater quantitative accuracy and valuable guidance and QA. The method was robust against anatomical deformation due to the radiographic scene's local nature used in registration, presenting a potentially major surgical benefit.

The Mid-term Results of Mitral Valve Repair for Isolated Mitral Regurgitation in Infancy and Childhood

The objective of this study was to assess the mid-term results of mitral valve (MV) repair in infancy and childhood with isolated mitral regurgitation (MR). From January 2005 to January 2016, 40 consecutive patients with isolated MR underwent MV repair in Fuwai Hospital, Beijing, China. Patients' clinical data were analyzed retrospectively. Mean age at operation was 13 ± 5 (6-24) months and 22 patients (55%) were younger than 1 year. Mean weight at operation was 8.5 ± 1.9 (4.2-13) kg and 34 patients (85%) were lighter than 10 kg. All patients presented moderate or greater MR. After MV repair, all patients had mild MR or none, while two patients underwent re-repair immediately when TEE showed moderate MR. Mean left atrial diameter decreased from 28.0 ± 6.5 to 20.7 ± 4.8 mm and mean left ventricular end-diastolic diameter decreased from 38.6 ± 7.0 to 30.2 ± 4.9 mm (p < 0.001 for both). There was no early death. Clinical follow-up was conducted in 37 patients over an average period of 49 ± 31 (20-134) months. Follow-up echocardiography showed that one patient had severe MR who underwent redo repair 14 months after operation, one patient had moderate to severe MR, and three patients had moderate MR. Overall freedom from moderate or greater MR was 96.3 ± 3.6%, 91.9 ± 5.5%, and 83.6 ± 9.4% at 2, 5, and 10 years, respectively. The early and mid-term results of MV repair in pediatric patients with isolated MR were satisfactory. In majority of patients, less complex surgical repair techniques were utilized, namely annuloplasty or commissuroplasty. The combination of various repair methods in complex patients could achieve excellent outcome.