Magnesium-Engineered Silica Framework for pH-Accelerated Biodegradation and DNAzyme-Triggered Chemotherapy

Inorganic nanocarriers have shown their high performance in disease theranostics in preclinical animal models and further great prospects for clinical translation. However, their dissatisfactory biodegradability and pre-drug leakage with nonspecificity to lesion sites significantly hinders the possible clinical translation. To solve these two critical issues, a framework-engineering strategy is introduced to simultaneously achieve enhanced biodegradability and controllable drug releasing, based on the mostly explored mesoporous silica-based nanosystems. The framework of mesoporous silica is engineered by direct Mg doping via a generic dissolution and regrowth approach, and it can transform into the easy biodegradation of magnesium silicate nanocarriers with simultaneous on-demand drug release. Such magnesium silicate nanocarriers can respond to the mild acidic environment of tumor tissue, causing the fast breaking up and biodegradation of the silica framework. More interesting, the released Mg²⁺ can further activate Mg²⁺ -dependent DNAzyme on the surface of hollow mesoporous magnesium silicate nanoparticles (HMMSNs) to cleave the RNA-based gatekeeper, which further accelerates the release of loaded anticancer drugs. Therefore, enhanced anticancer efficiency of chemotherapeutic drugs assisted by the biodegradable intelligent HMMSNs is achieved. The high biocompatibility of nanocarriers and biodegradation products is demonstrated and can be easily excreted via feces and urine guaranteeing their further clinical translation.

Towards enhanced tribological performance as water-based lubricant additive: Selective fluorination of graphene oxide at mild temperature

HYPOTHESIS

It is still difficult to prepare hydrophilic fluorinated graphene with abundant oxygen functional groups and high F/C ratio.

EXPERIMENTS

Herein, selective fluorination for graphene oxide (GO) was realized to prepare highly oxygen/fluorine dual functionalized graphene (OFG) under a mild temperature without damaging the sheet structure. Its O/C and F/C ratios came up to 0.58 and 0.19 respectively, which contained the intactly reserved oxygen functional groups from GO during fluorination and C-F bonds from addition reaction between aromatic region and F₂, as demonstrated via X-ray photoelectron spectroscopy (XPS), thermo gravimetric analysis (TGA), Raman measurements and so on.

FINDINGS

Experiments and density functional theory (DFT) calculations revealed that oxygen functional groups in-situ promoted addition reaction between aromatic region and F₂, and the critical point was confirmed that oxygen functional groups began to react with F₂ by substitution reaction. As-prepared OFG presented a 47% and 31% decrease of wear rate compared with that of pure water and GO, respectively. During friction process, the abundant oxygen functional groups of OFG contributed to hydrophilic property and introduced fluorine played an important role in enhancing the tribological performance by self-lubricating behavior. Such mild and simple method is achieved to expand the application of fluorinated graphene in aqueous environment.

The Tooth: Its Structure and Properties

This article provides a brief review of recent investigations concerning the structure and properties of the tooth. The last decade has brought a greater emphasis on the durability of the tooth, an improved understanding of the fatigue and fracture behavior of the principal tissues, and their importance to tooth failures. The primary contributions to tooth durability are discussed, including the process of placing a restoration, the impact of aging, and challenges posed by the oral environment. The significance of these findings to the dental community and their importance to the pursuit of lifelong oral health are highlighted.

Clinical value of the VTIQ technology in the differential diagnosis of superficially enlarged lymph nodes

Background Lymph node enlargement is a common clinical finding in clinical practice with different treatment strategies. Purpose To investigate the application of Virtual Touch Image Quantification (VTIQ) to diagnose benign and malignant superficial enlarged lymph nodes. Material and Methods Between December 2015 and August 2016, 116 superficial enlarged lymph nodes were examined by VTIQ. Maximum (V_max), minimum (V_min), and average (V_mean) shear wave velocities (SWV) were obtained from the lymph nodes and from normal muscular tissues (V_n) located at the same level and within 5 mm from the target lymph node. The pathological results were used as the gold standard to evaluate VTIQ. Results All 116 patients underwent fine-needle aspiration biopsy for pathological examination. Forty patients had malignant lymph nodes and 76 patients had benign lymph nodes. Lymph node characteristics on B-mode ultrasound showed no differences between malignant and benign lymph nodes, but there were differences in VTIQ parameters (all P < 0.001). Compared with pathological diagnosis as the gold standard, the area under the ROC curves of V_max, V_min, and V_mean were 0.815, 0.746, and 0.795. The V_max cutoff value to diagnose benign from malignant lymph nodes was 3.045 m/s. The sensitivity, specificity, and positive and negative predictive values were 70%, 78.9%, 63.6%, and 83.3%. Conclusion VTIQ has a clinical application in the differential diagnosis of superficial enlarged lymph nodes.

Human umbilical cord Wharton's jelly mesenchymal stem cells combined with an acellular cartilage extracellular matrix scaffold improve cartilage repair compared with microfracture in a caprine model

OBJECTIVE

As a novel and promising seed cell, human umbilical cord Wharton's jelly mesenchymal stem cells (hWJMSCs) are widely applied in tissue engineering. However, whether hWJMSCs can better repair and regenerate the articular cartilage in big animals than microfracture (MF, a predominant clinical treatment strategy for damaged cartilage) is unclear. Evaluation of the validity, and safety of hWJMSCs in a caprine model with a full-thickness femoral condyle articular cartilage defect, compared with MF is required.

METHODS

After cultivation and identification, hWJMSCs were seeded in an acellular cartilage extracellular matrix (ACECM)-oriented scaffold to construct cell-scaffold complex. Six goats with full-thickness femoral condyle articular cartilage defects were randomized to MF (microfracture group, MFG) and cell-scaffold complexes (experimental group, EG). At 2 and 4 weeks, joint fluid was used to assess immuno-inflammatory responses. At 6 and 9 months, all goats were euthanized for assessment of morphology, and magnetic resonance imaging (MRI), histology staining, and evaluation of the elasticity modulus and glycosaminoglycan (GAG) contents of the repaired regions.

RESULTS

There were no significant differences between the two groups in immuno-inflammatory parameters. MRI demonstrated higher-quality cartilage and complete subchondral bone at defect sites in the EG at 9 months. Histological staining showed that extracellular cartilage, cartilage lacuna and collagen type II levels were higher in the EG compared to the MFG, while the EG exhibited a higher elasticity modulus.

CONCLUSIONS

The hWJMSCs-ACECM scaffold complex achieved better quality repair and regeneration of hyaline cartilage without cartilage-inducing factor, while retaining the structure and functional integrity of the subchondral bone, compared with MF.

Complete mitochondrial genome of bamboo grasshopper, Ceracris fasciata, and the phylogenetic analyses and divergence time estimation of Caelifera (Orthoptera)

The bamboo grasshopper Ceracris fasciata is regarded as a major pest species because of the damage it causes to bamboo, and its classification within the families and subfamilies of the suborder Caelifera remains unclear. Thus, we attempted to resolve these questions using molecular biology methods and analyses. Our results are as follows: (1) the complete mitochondrial genome of C. fasciata is 15,569 bp in length. The mitochondrial genome contains a standard set of 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and an A + T-rich region in the same order as those of the other analysed Caeliferan species. The putative start codon for the COX1 gene in C. fasciata is ACC, although it is not defined in other genes. The presence of tandem repeats of different sizes in the A + T-rich region may lead to size differences in other mitochondrial genomes. The mitochondrial genome of C. fasciata harbours the typical 37 genes and an A + T-rich region, and it shows similar characteristics to those of other grasshopper species. Characterization of the mitochondrial genome has enriched our knowledge of the mitochondrial genomes of Orthoptera around the world. Therefore, the phylogenetic relationships in Orthoptera can be re-examined. (2) In phylogenetic analyses, the monophyly of Orthoptera and its two suborders (Caelifera and Ensifera) has been consistently recovered based on most of the datasets selected, regardless of the optimal criteria. Our results do not support the monophyly of the subfamily Oedipodinae of Caelifera. We found that Phlaeoba albonema of the Acridinae is sorted into a clade with Ceracris in all our phylogenetic trees, and field experiments show that Phlaeoba always lives with Ceracris in the same ecotopes. Therefore, we suggest that Phlaeoba should be classified as a member of the Oedipodinae. We found that C. fasciata always clustered with Ceracris kiangsu, and both were sisters to Ceracris versicolor. Therefore, the genetic relationship between C. fasciata and C. kiangsu is closer than that between C. fasciata and C. versicolor. (3) The oldest estimated time of divergence of Ensifera in this context was determined to be 146.16 million years ago (Mya), or around the late Jurassic or early Cretaceous. We estimated that katydids (Grylloidea) likely diverged from other groups in the early Cretaceous. According to our divergence time analyses, we concluded that the ancestral Acrididae probably originated in the early Paleogene, and it is likely that the major diversification events happened at the middle Paleogene, well into the next geologic time. We estimated that crickets (Tettigoniidae) likely diverged from other groups in the early Cretaceous. Acrididae and Romaleinae group, Pyrgacrididae and Ommexechidae group, the youngest two clades we observed, were estimated to have diverged 58.79 Mya, between the middle and early Paleogene. C. versicolor is a sister to the group containing C. kiangsu and C. fasciata. First, C. versicolor diverged from the sister group (C. kiangsu + C. fasciata) around 44.81 Mya, and then the C. kiangsu and C. fasciata group separated at 43.04 Mya.

Patch-Based Image Inpainting via Two-Stage Low Rank Approximation

To recover the corrupted pixels, traditional inpainting methods based on low-rank priors generally need to solve a convex optimization problem by an iterative singular value shrinkage algorithm. In this paper, we propose a simple method for image inpainting using low rank approximation, which avoids the time-consuming iterative shrinkage. Specifically, if similar patches of a corrupted image are identified and reshaped as vectors, then a patch matrix can be constructed by collecting these similar patch-vectors. Due to its columns being highly linearly correlated, this patch matrix is low-rank. Instead of using an iterative singular value shrinkage scheme, the proposed method utilizes low rank approximation with truncated singular values to derive a closed-form estimate for each patch matrix. Depending upon an observation that there exists a distinct gap in the singular spectrum of patch matrix, the rank of each patch matrix is empirically determined by a heuristic procedure. Inspired by the inpainting algorithms with component decomposition, a two-stage low rank approximation (TSLRA) scheme is designed to recover image structures and refine texture details of corrupted images. Experimental results on various inpainting tasks demonstrate that the proposed method is comparable and even superior to some state-of-the-art inpainting algorithms.

Effect of early fasting and total parenteral nutrition support on the healing of incision and nutritional status in patients after sacrectomy

INTRODUCTION

Surgical site infection is one of the most common complications for patients after sacrectomy, which often accompanied by poor wound healing, sinus formation and serious metabolic disturbance.

HYPOTHESIS

We tried to avoid the surgical site infection caused by feces during early period after surgery through early fasting and total parenteral nutrition (TPN) support, then compared the clinical results of these patients with other patients that received enteral nutrition (EN) early after sacrectomy.

METHODS

Forty-eight patients after sacrectomy (the level of sacrectomy above S₂) were randomly divided into two groups: TPN group and EN group. The patients of two groups received different nutrition support from the first day to the seventh day after surgery, then the factors such as nutritional and metabolic status after surgery, incidence of complications as well as the time of incision healing and hospitalization were observed.

RESULTS

The p-value of total serum protein, albumin, serum alanine aminotransferase, total bilirubin at seventh day after sacrectomy between TPN group and EN group is <0.0005. The p-value of hemoglobin at seventh day after sacrectomy between TPN group and EN group is 0.001. The p-value of total serum protein at fourteenth day after sacrectomy between TPN group and EN group is 0.003. The p-value of albumin and total bilirubin at fourteenth day after sacrectomy between TPN group and EN group is 0.001. The p-value of hemoglobin, serum alanine aminotransferase at fourteenth day after sacrectomy between TPN group and EN group is <0.0005. The incidence of gastrointestinal complication and delay of apparition of feces in EN group were lower than that in TPN group (p=0.041, p<0.0005). The incidence of surgical site infection, the time of incision healing and hospitalization in TPN group were lower than that in EN group (p=0.048, p=0.008, p<0.0005).

CONCLUSIONS

The method of fasting and supported by TPN during the early period after sacrectomy contribute to the incision healing, meanwhile, it shortens the hospitalization time and abates the incidence of complications in patients after sacrectomy.

TYPE OF STUDY

It is a comparative randomized study.

LEVEL OF PROOF

High-powered prospective randomized trial.

Lactic dehydrogenase to albumin ratio in prediction of unresectable pancreatic cancer with intervention chemotherapy

AIM

To validate the prognostic value of lactic dehydrogenase to albumin ratio (LAR) in patients with unresectable pancreatic cancer treated by intervention chemotherapy.

MATERIALS & METHODS

There were 139 patients retrospectively analyzed in this study. The survival was depicted with Kaplan-Meier curves and calculated by log-rank test. We used Cox proportional hazards regression model with univariate and multivariate analyses, and integrated all independent risk factors to establish the nomogram.

RESULTS

Patient with higher LAR group had poorer overall survival (OS). The Tumor, Node, Metastasis stage, carcinoembryonic antigen and LAR have been shown to be independent prognostic indicators for OS. The nomogram indicated superior predictive accuracy for OS.

CONCLUSION

The preoperative LAR can be a prognostic indicator for unresectable pancreatic cancer patients with interventional therapy.

miR-202 acts as a potential tumor suppressor in breast cancer

Breast cancer affects ~10% of women worldwide and is responsible for ~12% of all cancer-associated mortalities. Breast cancer is more prone to metastasis compared with other types of cancer. Up to 5% of patients with breast cancer present with incurable metastasis and an additional 10-15% of patients develop metastases within 3 years of their initial diagnosis. MicroRNAs (miRNAs) are short RNAs, 21-25 nucleotides in length, that have been shown to significantly affect gene expression. In total >2,000 miRNAs have been identified and specific miRNAs have been revealed to be associated with cancer. In the present study, we observed that the majority of breast cancer specimens collected expressed low levels of miR-202 compared with adjacent tissues and normal cell lines. Mechanistic investigations identified KRAS as a potential target gene of miR-202 and it was demonstrated that miR-202 exerted its tumor-suppressive effects by regulating the expression of KRAS in breast cancer cells. Functional assays revealed that miR-202 significantly reduced cell proliferation, migration and invasion in vitro. In summary, these results indicate the function of miR-202 in breast cancer progression and suggest that its use within breast cancer therapy is promising.

A novel HLA-B allele, HLA-B*40:245 was identified in a patient with hepatitis B virus infection

A novel allele HLA-B*40:245 was discovered in a hepatitis B virus (HBV) infected patient.

The latest exploration of staging and prognostic classification for pancreatic neuroendocrine tumors: a large population-based study

Background: A modified European Neuroendocrine Tumor Society (mENETS) staging system has been confirmed to be more suitable for pancreatic neuroendocrine tumors (pNETs) when compared to the American Joint Committee on Cancer (AJCC) or the European Neuroendocrine Tumor Society (ENETS) systems in the last few years. However, the importance of N stage has been recently published with several significant updates. Methods: SEER registry (n = 2,209) was used to evaluate the application of the AJCC 7th staging system, ENETS staging system, mENETS staging system and reformed ENETS (rENETS) staging system in this study. Results: For the ENETS staging system, patients with stage I disease had a similar prognosis to patients with stage II disease (P=0.154), and patients with stage IIIA and stage IIIB diseases showed adverse prognostic potential. The proportion of patients with stage III diseases using AJCC 7th staging system was extremely lower than those with mENETS staging system or rENETS staging system (3.6%, 23.0% and 23.7%, respectively). Furthermore, the hazard ratio of death for patients with stage II or III disease using rENETS staging system was slightly higher than that of mENETS staging system. Besides, survival curves were better separated by rENETS staging system. A prognostic nomogram for overall survival (OS) was formulated to obtain superior discriminatory abilities. Conclusions: The rENETS staging system has superior distribution in proportion than the AJCC 7th, ENETS or mENETS staging system, and one more accurate and advanced predictive model will be achieved via the incorporation to be adopted in clinical practice.

Applying ultraviolet/persulfate (UV/PS) pre-oxidation for controlling ultrafiltration membrane fouling by natural organic matter (NOM) in surface water

Membrane fouling is a recognized obstacle for the application of ultrafiltration (UF) for drinking water treatment. In this study, ultraviolet/persulfate (UV/PS) oxidation was employed as a pretreatment to control membrane fouling caused by natural organic matter (NOM) in surface water. The effects of UV/PS pretreatment on amounts and characteristics of NOM were investigated in terms of dissolved organic carbon, fluorescent spectrum, molecular weight distribution and hydrophobicity. UF membrane fouling during filtration of raw and pre-oxidized water was compared with transmembrane pressure development, and the fouled membranes were further characterized using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The results indicate that NOM was considerably degraded and partially mineralized (∼58%) by UV/PS pretreatment at a PS dose not exceeding 0.6 mM and a UV irradiation time within 120 min, which was attributed to the generation of sulfate and hydroxyl radicals. The fluorescent compounds in NOM were almost completely degraded (>98%) by the UV/PS pretreatment at a PS dose of 0.4 mM, except for tyrosine-like proteins (∼80%). Moreover, UV/PS pretreatment decreased the ratio of macromolecular compounds and increased the hydrophilic fractions, resulting in reduced NOM adhesion to the membrane. Hence, irreversible fouling by NOM was significantly retarded (∼75%) by the UV/PS pretreatment due to reduction in NOM, and more importantly by preferential degradation of fluorescent, macromolecular and hydrophobic compounds. Fouling control performance was considerably improved at increased PS doses and extended UV irradiation time.

[Trends in 30-day case fatality rate in patients hospitalized due to acute myocardial infarction in Beijing, 2007-2012]

Objective: To understand the distribution and trends in 30-day coronary heart disease (CHD) case fatality rate in patients hospitalized due to acute myocardial infarction (AMI) in Beijing during 2007-2012. Methods: The clinical data of patients hospitalized due to AMI in Beijing from 1 January 2007 to 31 December 2012 were collected from "The Cardiovascular Disease Surveillance System in Beijing" . A total of 77 943 local patients aged ≥25 years were hospitalized due to AMI in Beijing during the this period. After excluding duplicate records and validation for the completeness and accuracy of the records, the clinical characteristics of the patients and 30-day CHD case fatality rate in the patients were analyzed. Trends in 30-day CHD case fatality rate in the patients were analyzed with Poisson regression models. Results: The age-standardized average 30-day CHD case fatality rate was 9.7% in the 77 943 patients. During this period, a decreasing trend was observed in 30-day CHD case fatality rate after adjusting for age and gender (P<0.001). The age-standardized 30-day CHD case fatality rate decreased by 16.0%, from 10.8% in 2007 to 9.0% in 2012. The decreases of 30-day CHD case fatality rates were noted in both men and women, whereas 30-day CHD case fatality rate was higher in women (14.1%) than in men (7.6%) after adjusting for age. During this period, the proportion of ST-segment elevation myocardial infarction (STEMI) decreased, while the proportion of non-ST-segment elevation myocardial infarction (NSTEMI) increased with year. A significant decline (20.1%) in 30-day case fatality rate of STEMI was found, but no decline was found for 30-day mortality rate of NSTEMI. Conclusion: A decreasing trend in 30-day CHD case fatality rate was observed in the patients aged ≥25 years and hospitalized due to AMI in Beijing during 2007-2012, indicating the improvement in short-term prognosis of patients hospitalized due to AMI. Our findings highlight the urgent need to improve the treatment for woman and NSTEMI patients.

[Effects of ammonium pyrrolidine dithiocarbamate (PDTC) on osteopontin expression and autophagy in tubular cells in streptozotocin-induced diabetic nephropathy rat]

Objective: To investigate the effects of ammonium pyrrolidine dithiocarbamate (PDTC) on tubulointerstitial inflammatory molecules and autophagy in diabetic nephropathy (DN) rats. Methods: Twenty-four male Sprague-Dawley rats were assigned to DN group (n=6) and DN+ PDTC group (n=6, PDTC, ip, 100 mg·kg^-1·d^-1), all received streptozotocin (STZ) 60 mg/kg intraperitoneally, and the other 12 rats were randomly divided into control group (n=6) and PDTC group (n=6). At the end of 12 weeks, after serum creatine (Scr) and 24-hour urinary protein were determined, rats were sacrificed to determined the renal pathological damages and the changes of nuclear factor (NF)-κB p65, p62, osteopontin (OPN), microtubule associated protein 1 light chain 3 (LC3)-Ⅱ/LC3-Ⅰ, nuclear p-NF-κB p65 by immunohistological stainning and Western blot, and ultrastructural changes of autophagic process was observed by electron microscopy (EM). Results: Scr was similar among the four groups (P>0.05). The levels of urinary protein in DN group and DN + PDTC group were significantly higher than the other two groups (all P<0.01), but the level of urinary protein in DN + PDTC group was lower than that of DN group (P<0.05). DN + PDTC group had less tubulointerstitial damage compared with DN group (P<0.05). Among the four groups, expressions of p62, p65, OPN of tubulointerstitial area in DN group were significantly higher than that of the other groups (all P<0.05), and Western blot showed that DN+ PDTC group had less expressions of NF-κB p65, nuclear p-p65, OPN and more expresssion of LC3-Ⅱ/LC3-Ⅰ compared with DN group (all P<0.05), which were consistent with the decreased autophagic vacuoles and increased mitochondria dysfunction revealed by EM. Correlation analysis showed that renal LC3-Ⅱ/LC3-Ⅰ was negatively correlated the expressions of nuclear p-p65 and OPN (r=-0.45, P=0.02; r=-0.50, P=0.01), and p62 was positively correlated the expressions of nuclear p-p65 and OPN (r=0.33, P=0.01; r=0.41, P=0.01). Conclusion: Tubular NF-κB activation is closely related to autophagy dysfunction in DN rats, and PDTC may enhance autophagy activity in tubule cells by blocking NF-κB activity.

Abstract P6-08-15: Not presented

This abstract was not presented at the symposium.