SERS detection platform based on a nucleic acid aptamer-functionalized Au nano-dodecahedron array for efficient simultaneous testing of colorectal cancer-associated microRNAs.

A surface-enhanced Raman scattering (SERS) detection platform was constructed based on Au nano-dodecahedrons (AuNDs) functionalized with nucleic acid aptamer-specific binding and self-assembly techniques. SERS labels were prepared by modifying Raman signaling molecules and complementary aptamer chains and were bound on the aptamer-functionalized AuNDs array. Using this protocol, the limits of detection (LODs) of miR-21 and miR-18a in the serum were 6.8 pM and 7.6 pM, respectively, and the detection time was 5 min. Additionally, miR-21 and miR-18a were detected in the serum of a mouse model of colorectal cancer. The results of this protocol were consistent with quantitative real-time polymerase chain reaction (qRT-PCR). This method provides an efficient and rapid method for the simultaneous testing of miRNAs, which has great potential clinical value for the early detection of colorectal cancer (CRC).

Self-Assembled Virus-Like Particle Vaccines via Fluorophilic Interactions Enable Infection Mimicry and Immune Protection.

Influenza epidemics persistently threaten global health. Vaccines based on virus-like particles (VLPs), which resemble the native conformation of viruses, have emerged as vaccine candidates. However, the production of VLPs via genetic engineering remains constrained by challenges such as low yields, high costs, and being time consuming. In this study, a novel VLP platform is developed that could mimic infection and confer influenza protection through fluorination-driven self-assembly. The VLPs closely mimick the key steps in viral infection including dendritic cell (DC) attachment and pH-responsive endo-lysosomal escape, which enhances DC maturation and antigen cross-presentation. It is also observed that the VLPs migrate from the injection site to the draining lymph nodes efficiently. Immunization with VLPs triggers both Th1 and Th2 cellular responses, thereby inducing an improved CD8+ T cell response along with strong antigen-specific antibody responses. In several infected mouse models, VLP vaccines ameliorate weight loss, lung virus titers, pulmonary pathologies, and confer full protection against H1N1, H6N2, H9N2, and mixed influenza viruses. Therefore, the results support the potential of VLPs as an effective influenza vaccine with improved immune potency against infection. A methodology to generate VLPs based on fluorophilic interactions, which can be a general approach for development of pathogenic VLPs, is reported.

Image acquisition as novel colonoscopic quality indicator: a single-center retrospective study.

Purpose: In order to reduce the incidence and mortality of colorectal cancer, improving the quality of colonoscopy is the top priority. At present, the adenoma detection rate is the most used index to evaluate the quality of colonoscopy. So, we further verified the relevant factors influencing the quality of colonoscopy and found out the novel quality indicators by studying the relationship between the influencing factors and the adenoma detection rate. Materials/methods: The study included 3824 cases of colonoscopy from January to December 2020. We retrospectively recorded the age and sex of the subjects; the number, size, and histological features of lesions; withdrawal time and the number of images acquired during colonoscopy. We analyzed the associated factors affecting adenoma and polyp detection, and verified their effectiveness with both univariate and multivariate logistic regression analyses. Results: Logistic regression analyses showed that gender, age, withdrawal time and the number of images acquired during colonoscopy could serve as independent predictors of adenoma/polyp detection rate. In addition, adenoma detection rate (25.36% vs. 14.29%) and polyp detection rate (53.99% vs. 34.42%) showed a marked increase when the number of images taken during colonoscopy was ≥29 (P<0.001). Conclusions: Gender, age, withdrawal time and the number of images acquired during colonoscopy are influencing factors for the detection of colorectal adenomas and polyps. And we can gain higher adenoma/polyp detection rate when endoscopists capture more colonoscopic images.

Antibiotic Resistance of Helicobacter pylori and Related Risk Factors in Yangzhou, China: A Cross-Sectional Study.

BACKGROUND: The antibiotic resistance of Helicobacter pylori (H. pylori) is a common cause of treatment failure. Previous studies showed that H. pylori resistance may be related to some characteristics of patients. This study intended to investigate the resistance of H. pylori to five commonly used antibiotics and risk factors in Yangzhou, China. METHODS: We recruited the subjects who joined the endoscopic screening program organized by the Affiliated Hospital of Yangzhou University between April 2018 and September 2019 and endoscopists would take biopsy samples from the antrum and the corpus of the stomach. The antrum biopsy specimens were used to culture H. pylori. Next, we extracted DNA from H. pylori strains and performed the specific DNA amplification. Finally, we use gene chip technology to test the susceptibility to clarithromycin, levofloxacin, metronidazole, amoxicillin and tetracycline. Multivariate logistic analyses were also performed to determine the risk factors for antibiotic resistance of H. pylori. RESULTS: A total of 461 H. pylori strains were finally collected. The resistance rate of H. pylori to clarithromycin, levofloxacin, metronidazole, amoxicillin and tetracycline was 41.0%, 44.9%, 38.8%, 6.3% and 1.1%, respectively. In addition, 16 multi-resistance patterns were detected, and strains resistant to all five antibiotics were not found. Multivariate analysis showed that past medical history and clinical outcomes were significantly associated with the resistance to clarithromycin. Drinking, gastrointestinal symptoms and a family history of gastric cancer were significantly associated with the resistance of H. pylori to levofloxacin. Especially gastrointestinal symptoms were significantly associated with the resistance of H. pylori to any antibiotic. CONCLUSION: The resistance rates of H. pylori to clarithromycin, levofloxacin and metronidazole were very high in Yangzhou, China, various factors were related to bacterial resistance, and grasping these influencing factors can guide treatment.

The predictive value of routine laboratory tests for colorectal polyps: a retrospective study.

Background: Colorectal cancer (CRC) has become the malignant tumor of the digestive tract with the highest incidence in our country, posing a serious threat to the health of our people. Early colon cancer is mostly due to the malignant transformation of colon polyps, so that early detection and resection have been shown to be effective in reducing the incidence and mortality of CRC. This study tried to investigate the related risk factors of and construct a predictive nomogram for colorectal polyps, providing meaningful guidance basis for risk stratification and screening. Methods: A total of 1,799 patients who underwent colonoscopies in the Health Management Centre of the Affiliated Hospital of Yangzhou University were recruited to this study. Univariate and multivariate logistic analyses were performed to determine the risk factors for colorectal polyps, and a predictive nomogram was constructed based on the multivariable model. We determined the predictive value of the nomogram by receiver operating characteristic (ROC) curve, calibration curve, and decision curve analyses (DCAs). Results: The logistic regression analysis showed that age (P<0.001), gender (P<0.001), eosinophil count (P=0.005), hemoglobin level (P=0.039), and LDL-C/HDL-C ratio (LHR; P<0.001) were independent predictors of the development of colorectal polyps. The above independent risk factors were incorporated, and an individualized nomogram model was successfully established. The C-index of the nomogram was 0.679 in our model, and with the bootstrap method, the prediction curve fit well with the ideal curve, suggesting that the prediction curve constructed in this study has good predictive ability. Conclusions: Age, gender, eosinophil count, hemoglobin level, and LHR are risk factors for the development of colorectal polyps. Establishing a nomogram prediction model for colorectal polyps is helpful for the early clinical screening of high-risk patients with colorectal polyps, improving the detection rate of polyps and reducing the incidence of colorectal cancer (CRC).

Astilbin combined with lipopolysaccharide induces IL-10-producing regulatory B cells via the STAT3 signalling pathway.

OBJECTIVES: Astilbin exerts immunoregulatory activities and plays anti-inflammatory effects in inflammation-associated diseases. IL-10-producing B cells are the major subset of regulatory B cells (Bregs) and inhibit inflammation and autoimmune diseases. This study aimed to analyse the inducing effect of astilbin on Bregs and investigate the involved molecular mechanisms. METHODS: The frequencies and activities of IL-10-producing Bregs were observed using the co-treatment of astilbin and lipopolysaccharide (LPS) ex vivo. The protective effect of astilbin/LPS-induced Bregs on dextran sulphate sodium (DSS)-induced colitis was confirmed in vivo. The molecular signalling events of Breg induction were checked via Western blot. CD40-/- and toll-like receptor (TLR) 4-/- B cells were treated with astilbin/LPS to determine the modulatory role of CD40 or TLR4 on astilbin/LPS-induced Bregs. RESULTS: Although astilbin alone could not affect Bregs, the co-treatment of astilbin and LPS remarkably induced CD19+ CD1dhi and CD19+ TIM-1+ cells which produced IL-10 ex vivo. Colonic CD19+ CD1dhi and CD19+ TIM-1+ cells were also increased in astilbin-treated mice with DSS-induced colitis. The adoptive transfer of CD19+ TIM-1+ cells pre-induced by astilbin/LPS directly suppressed the progression of DSS-induced colitis. Combined astilbin and LPS stimulated the STAT3 activation of CD19+ TIM-1+ cells but had no effects on SOCS3, AKT, NF-κB, Erk, JNK nor P38. Inhibiting the STAT3 phosphorylation of CD19+ TIM-1+ cells abolished Breg induction by astilbin/LPS. Furthermore, Breg induction was weakened in CD40-/- B cells with the decrease in STAT3 activation, but had disappeared in TLR4-/- B cells with no STAT3 activation, thereby confirming the indispensable role of TLR4 signalling in the induction of IL-10-producing Bregs. CONCLUSIONS: This study reports the new immunoregulatory role of astilbin for promoting IL-10-producing B cells and suggests the possible use of astilbin in the therapy of inflammatory diseases.

Astilbin promotes the induction of regulatory NK1.1- CD4+ NKG2D+ T cells through the PI3K, STAT3, and MAPK signaling pathways.

Astilbin is a potential agent for autoimmune and inflammatory diseases and has a protective effect in mice with DSS-induced colitis. NK1.1- CD4+ NKG2D+ T cells are a subpopulation of regulatory T cells that produce TGF-ß1 and IL-10. Whether astilbin directly promotes the induction of NK1.1- CD4+ NKG2D+ T cells and whether these astilbin-stimulated T cells exert an immune-regulatory role remain unclear. Here, we show that astilbin efficiently induces the production of NK1.1- CD4+ NKG2D+ T cells with high expressions of TGF-ß1, IL-10, CCR6, and CCR9 in a dose-dependent manner ex vivo. These regulatory T cells also substantially inhibit the activities of CD8+ T cells and macrophages. Intraperitoneal injection of astilbin ameliorates the severity of colitis with an increase in the frequency of NK1.1- CD4+ NKG2D+ T cells in the colon tissue of DSS-treated mice. Moreover, adoptive transfer of NK1.1- CD4+ NKG2D+ T cells induced by astilbin remarkably protects against the onset of DSS-induced colitis. Finally, the PI3K, STAT3, and MAPK signaling pathways are involved in the induction of NK1.1- CD4+ NKG2D+ T cells by astilbin. Taken together, our study elucidates a new immune-regulatory mechanism of astilbin by inducing the regulatory NK1.1- CD4+ NKG2D+ T cells and indicates a potential clinical use of astilbin for patients with inflammatory bowel diseases.

Long-term storage of lyophilized liposomal formulations.

Because aqueous liposomal formulations containing multiply unsaturated lipids are susceptible to chemical degradation, these formulations are often lyophilized. Despite their limited chemical stability, interest in the use of multiply unsaturated lipids to promote intracellular delivery has increased considerably in recent years. The goal of the current study was to examine the long-term storage stability of lyophilized formulations containing lipids with increasing levels of unsaturation, and various strategies that can be employed to improve stability. Aqueous lipid-trehalose formulations containing 1,2-dilinolenoyl-sn-glycero-3-phosphocholine (DLPC), 1,2-dilinoleoyl-sn-glycero-3-phosphocholine (DLinPC), or 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) were lyophilized and stored at temperatures ranging from 4°C to 60°C. We observed that the lipid degradation rate increased as the storage temperature and unsaturation level were increased. Even the cleanest sugars, which are available commercially, contain iron contaminants, and it was observed that the chelation of these iron contaminants significantly improved the stability of DLPC during storage. However, the glass transition temperature of the sugar that was included in the formulation, the reduction of the oxygen in the aqueous sample prior to lyophilization, the inclusion of helper lipids (i.e., cholesterol), and the rate of freezing did not significantly improve stability.

Storage stability of keratinocyte growth factor-2 in lyophilized formulations: effects of formulation physical properties and protein fraction at the solid-air interface.

Lyophilized formulations of keratinocyte growth factor-2 (KGF-2) were prepared with a range of disaccharide (sucrose or trehalose) and hydroxyethyl starch (HES) mass ratios. Protein degradation was assessed as a function of time of storage of the dried formulations at 40, 50 and 60°C. Lyophilized and stored samples were rehydrated, and protein degradation was quantified by measuring loss of monomeric protein with size exclusion chromatography and by determining chemical degradation in the soluble fraction with reverse-phase chromatography. The secondary structure of the protein in the lyophilized formulations was studied with infrared spectroscopy. The magnitudes of degradation were compared the key physical properties of the formulations including retention of protein native secondary structure, glass transition temperature (Tg), inverse mean square displacements 〈u(2)〉(-1) for hydrogen atoms (fast ß relaxation), and the relaxation time τ(ß), which correlates with relaxation due to fast Johari-Goldstein motions in the glass (Xu et al., 2013) [1]. In addition, specific surface areas of the lyophilized formulations were determined by Brunauer-Emmet-Teller analysis of krypton adsorption isotherms and used to estimate the fraction of the KGF-2 molecules residing at the solid-air interface. KGF-2 degradation rates were highest in formulations wherein the protein's structure was most perturbed, and wherein ß relaxations were fastest, but the dominant factor governing KGF-2 degradation in freeze-dried formulations was the fraction of the protein found at the glass solid-air interface.

Protein quantity on the air-solid interface determines degradation rates of human growth hormone in lyophilized samples.

Recombinant human growth hormone (rhGH) was lyophilized with various glass-forming stabilizers, employing cycles that incorporated various freezing and annealing procedures to manipulate glass formation kinetics, associated relaxation processes, and glass-specific surface areas (SSAs). The secondary structure in the cake was monitored by infrared and in reconstituted samples by circular dichroism. The rhGH concentrations on the surface of lyophilized powders were determined from electron spectroscopy for chemical analysis. Glass transition temperature (Tg ), SSAs, and water contents were determined immediately after lyophilization. Lyophilized samples were incubated at 323 K for 16 weeks, and the resulting extents of rhGH aggregation, oxidation, and deamidation were determined after rehydration. Water contents and Tg were independent of lyophilization process parameters. Compared with samples lyophilized after rapid freezing, rhGH in samples that had been annealed in frozen solids prior to drying, or annealed in glassy solids after secondary drying retained more native-like protein secondary structure, had a smaller fraction of the protein on the surface of the cake, and exhibited lower levels of degradation during incubation. A simple kinetic model suggested that the differences in the extent of rhGH degradation during storage in the dried state between different formulations and processing methods could largely be ascribed to the associated levels of rhGH at the solid-air interface after lyophilization.

[Application of X ray cephalogram in the measurement of adenoids in children].

PURPOSE: To evaluate the clinical value of X ray lateral cephalogram in the measurement of adenoids in children. METHODS: 45 cases (aged from 3 to 13 year old) with adenoid hypertrophy suspected clinically were examined with lateral cephalometric projections, of which 40 cases were examined with lateral nasopharyngeal projections at one time. Then the quality of films were appraisal and the adenoids were measured on the film. Student's X(2) test was used for statistics analysis. RESULTS: X ray lateral cephalogram can distinctly reveal the structure of nasopharynx. The method was simply and reproducible. The quality of the films were determined based on the conjunction between the base of the pterygoid plate and extracranial aspect of the occipital slope, with consideration of the mandibular margin and sphenoid saddle. The conjunction should be clearly demonstrated and the edges of the mandibular margin and sphenoid saddle should be sharp and well demarcated in qualified films. 45 cases were examined with lateral cephalometric projections, 34 cases had standard films, accounting for 76%. 40 cases were examined with lateral nasopharyngeal projections, 21 had standard films, accounting for 53%. The quality of X ray lateral cephalogram was significantly better than lateral nasopharyngeal projections (P<0.05). CONCLUSION: Compared with the routine lateral nasopharyngeal projection, lateral nasopharyngeal cephalogram has images of high quality, is better for showing the nasopharyngeal structures as well as measurement of the adenoids with parenchyma. It is the imaging method of choice for children with OSAHS.