Improved camptothecin encapsulation and efficacy by environmentally sensitive block copolymer/chitosan/fucoidan nanoparticles for targeting lung cancer cells.

In this study, thermo-sensitive poly(N-isopropyl acrylamide) (PNP) was polymerized with pH-sensitive poly(acrylic acid) (PAA) to prepare a PAA-b-PNP block copolymer. Above its cloud point, the block copolymer self-assembled into nanoparticles (NPs), encapsulating the anticancer drug camptothecin (CPT) in situ. Chitosan (CS) and fucoidan (Fu) further modified these NPs, forming Fu-CPT-NPs to enhance biocompatibility, drug encapsulation efficiency (EE), and loading content (LC), crucially facilitating P-selectin targeting of lung cancer cells through a drug delivery system. The EE and LC reached 82 % and 3.5 %, respectively. According to transmission electron microscope observation, these Fu-CPT-NPs had uniform spherical shapes with an average diameter of ca. 250 nm. They could maintain their stability in a pH range of 5.0-6.8. In vitro experimental results revealed that the Fu-CPT-NPs exhibited good biocompatibility and had anticancer activity after encapsulating CPT. It could deliver CPT to cancer cells by targeting P-selectin, effectively increasing cell uptake and inducing cell apoptosis. Animal study results showed that the Fu-CPT-NPs inhibited lung tumor growth by increasing tumor cell apoptosis without causing significant tissue damage related to generating reactive oxygen species in lung cancer cells. This system can effectively improve drug-delivery efficiency and treatment effects and has great potential for treating lung cancer.

Enhancing UAV Visual Landing Recognition with YOLO's Object Detection by Onboard Edge Computing.

A visual camera system combined with the unmanned aerial vehicle (UAV) onboard edge computer should deploy an efficient object detection ability, increase the frame per second rate of the object of interest, and the wide searching ability of the gimbal camera for finding the emergent landing platform and for future reconnaissance area missions. This paper proposes an approach to enhance the visual capabilities of this system by using the You Only Look Once (YOLO)-based object detection (OD) with Tensor RTTM acceleration technique, an automated visual tracking gimbal camera control system, and multithread programing for image transmission to the ground station. With lightweight edge computing (EC), the mean average precision (mAP) was satisfied and we achieved a higher frame per second (FPS) rate via YOLO accelerated with TensorRT for an onboard UAV. The OD compares four YOLO models to recognize objects of interest for landing spots at the home university first. Then, the trained dataset with YOLOv4-tiny was successfully applied to another field with a distance of more than 100 km. The system's capability to accurately recognize a different landing point in new and unknown environments is demonstrated successfully. The proposed approach substantially reduces the data transmission and processing time to ground stations with automated visual tracking gimbal control, and results in rapid OD and the feasibility of using NVIDIA JetsonTM Xavier NX by deploying YOLOs with more than 35 FPS for the UAV. The enhanced visual landing and future reconnaissance mission capabilities of real-time UAVs were demonstrated.

Dopamine-dependent functions of hyaluronic acid/dopamine/silk fibroin hydrogels that highly enhance N-acetyl-L-cysteine (NAC) delivered from nasal cavity to brain tissue through a near-infrared photothermal effect on the NAC-loaded hydrogels.

Hyaluronic acid/silk fibroin (HA/SF or HS) hydrogels with remarkable mechanical characteristics have been reported as tissue engineering biomaterials. Herein, the addition of dopamine/polydopamine (DA/PDA) to HS hydrogels to develop multifunctional HA/PDA/SF (or HDS) hydrogels for the delivery of drugs such as N-acetyl-L-cysteine (NAC) from nasal to brain tissue is examined. Herein, DA-dependent functions of HDS hydrogels with highly adhesive forces, photothermal response (PTR) effects generated by near infrared (NIR) irradiation, and anti-oxidative effects were demonstrated. An in-vitro study shows that the HDS/NAC hydrogels could open tight junctions in the RPMI 2650 cell line, a model cell of the nasal mucosa, as demonstrated by the decreased values of transepithelial electrical resistance (TEER) and more discrete ZO-1 staining than those for the control group. This effect was markedly enhanced by NIR irradiation of the HDS/NAC-NIR hydrogels. Compared to the results obtained using NAC solution, an in-vivo imaging study (IVIS) in rats showed an approximately nine-fold increase in the quantity of NAC delivered from the nasal cavity to the brain tissue in the span of 2 h through the PTR effect generated by the NIR irradiation of the nasal tissue and administration of the HDS/NAC hydrogels. Herein, dopamine-dependent multifunctional HDS hydrogels were studied, and the nasal administration of HDS/NAC-NIR hydrogels with PTR effects generated by NIR irradiation was found to have significantly enhanced NAC delivery to brain tissues.

Identification of tumor immunophenotypes associated with immunotherapy response in bladder cancer.

OBJECTIVES: This study aims to reveal immunophenotypes associated with immunotherapy response in bladder cancer, identify the signature genes of immune subtypes, and provide new molecular targets for improving immunotherapy response. METHODS: Bladder cancer immunophenotypes were characterized in the bulk RNA sequencing dataset GSE32894 and Imvigor210, and gene expression signatures were established to identify the immunophenotypes. Expression of gene signatures were validated in single-cell RNA sequencing dataset GSE145140 and human proteins expression data source. Investigation of Immunotherapy Response was performed in IMvigor210 dataset. Prognosis of tumor immunophenotypes was further analyzed. RESULTS: Inflamed and immune-excluded immunophenotypes were characterized based on the tumor immune cell scores. Risk score models that were established rely on RNA sequencing profiles and overall survival of bladder cancer cohorts. The inflamed tumors had lower risk scores, and the low-risk tumors were more likely to respond to atezolizumab, receiving complete response/partial response (CR/PR). Patients who responded to atezolizumab had higher SRRM4 and lower NPHS1 and TMEM72 expression than the non-responders. SRRM4 expression was a protective factor for bladder cancer prognosis, while the NPHS1 and TMEM72 showed the opposite pattern. CONCLUSION: This study provided a novel classification method for tumor immunophenotypes. Bladder cancer immunophenotypes can predict the response to immune checkpoint blockade. The immunophenotypes can be identified by the expression of signature genes.

In Situ Encapsulation of Camptothecin by Self-Assembly of Poly(acrylic acid)-b-Poly(N-Isopropylacrylamide) and Chitosan for Controlled Drug Delivery.

Camptothecin (CPT) has been shown to exhibit anticancer activity against several cancers. Nevertheless, CPT is very hydrophobic with poor stability, and thus its medical application is limited. Therefore, various drug carriers have been exploited for effectively delivering CPT to the targeted cancer site. In this study, a dual pH/thermo-responsive block copolymer of poly(acrylic acid-b-N-isopropylacrylamide) (PAA-b-PNP) was synthesized and applied to encapsulate CPT. At temperatures above its cloud point, the block copolymer self-assembled to form nanoparticles (NPs) and in situ encapsulate CPT, owing to their hydrophobic interaction as evidenced by fluorescence spectrometry. Chitosan (CS) was further applied on the surface through the formation of a polyelectrolyte complex with PAA for improving biocompatibility. The average particle size and zeta potential of the developed PAA-b-PNP/CPT/CS NPs in a buffer solution were 168 nm and -30.6 mV, respectively. These NPs were still stable at least for 1 month. The PAA-b-PNP/CS NPs exhibited good biocompatibility toward NIH 3T3 cells. Moreover, they could protect the CPT at pH 2.0 with a very slow-release rate. At pH 6.0, these NPs could be internalized by Caco-2 cells, followed by intracellular release of the CPT. They became highly swollen at pH 7.4, and the released CPT was able to diffuse into the cells at higher intensity. Among several cancer cell lines, the highest cytotoxicity was observed for H460 cells. As a result, these environmentally-responsive NPs have the potential to be applied in oral administration.

Multicenter analysis and a rapid screening model to predict early novel coronavirus pneumonia using a random forest algorithm.

ABSTRACT: Early determination of coronavirus disease 2019 (COVID-19) pneumonia from numerous suspected cases is critical for the early isolation and treatment of patients.The purpose of the study was to develop and validate a rapid screening model to predict early COVID-19 pneumonia from suspected cases using a random forest algorithm in China.A total of 914 initially suspected COVID-19 pneumonia in multiple centers were prospectively included. The computer-assisted embedding method was used to screen the variables. The random forest algorithm was adopted to build a rapid screening model based on the training set. The screening model was evaluated by the confusion matrix and receiver operating characteristic (ROC) analysis in the validation.The rapid screening model was set up based on 4 epidemiological features, 3 clinical manifestations, decreased white blood cell count and lymphocytes, and imaging changes on chest X-ray or computed tomography. The area under the ROC curve was 0.956, and the model had a sensitivity of 83.82% and a specificity of 89.57%. The confusion matrix revealed that the prospective screening model had an accuracy of 87.0% for predicting early COVID-19 pneumonia.Here, we developed and validated a rapid screening model that could predict early COVID-19 pneumonia with high sensitivity and specificity. The use of this model to screen for COVID-19 pneumonia have epidemiological and clinical significance.

Hepatocellular carcinoma progression in hepatitis B virus-related cirrhosis patients receiving nucleoside (acid) analogs therapy: A retrospective cross-sectional study.

BACKGROUND: Antiviral therapy cannot completely block the progression of hepatitis B to hepatocellular carcinoma (HCC). Furthermore, there are few predictors of early HCC progression and limited strategies to prevent progression in patients with HBV-related cirrhosis who receive nucleos(t)ide analog (NA) therapy. AIM: The study aim was to clarify risk factors and the diagnostic value of alpha-fetoprotein (AFP) for HCC progression in NA-treated hepatitis B virus (HBV)-related cirrhosis patients. METHODS: In this retrospective cross-sectional study, we analyzed the clinical data of 266 patients with HBV-related cirrhosis who received NA treatment between February 2014 and April 2020 at Zhejiang Provincial People's Hospital. The patients were divided into two groups, 145 who did not progress to HCC (No-HCC group), and 121 who progressed to HCC during NA treatment (HCC group). The logistic regression analysis was used to analyze the risk factors of HCC progression. The diagnostic value of AFP for HCC was evaluated by receiver operating characteristic (ROC) curve analysis. RESULTS: Univariate analysis showed that age ≥ 60 years (P = 0.001), hepatitis B and alcoholic etiology (P = 0.007), smoking history (P < 0.001), family history of HBV-related HCC (P = 0.002), lamivudine resistance (P = 0.011), HBV DNA negative (P = 0.023), aspartate aminotransferase > 80 U/L (P = 0.002), gamma-glutamyl transpeptidase > 120 U/L (P = 0.001), alkaline phosphatase > 250 U/L (P = 0.001), fasting blood glucose (FBG) ≥ 6.16 (mmol/L) (P = 0.001) and Child-Pugh class C (P = 0.005) were correlated with HCC progression. In multivariate analysis, age ≥ 60 years [hazard ratio (HR) = 3.089, 95% confidence interval (CI): 1.437-6.631, P = 0.004], smoking history (HR = 4.001, 95%CI: 1.836-8.716, P < 0.01), family history of HBV-related HCC (HR = 6.763, 95%CI: 1.253-36.499, P < 0.05), lamivudine resistance (HR = 2.949, 95%CI: 1.207-7.208, P = 0.018), HBV DNA negative (HR = 0.026, 95%CI: 0.007-0.139, P < 0.01), FBG ≥ 6.16 mmol/L (HR = 7.219, 95%CI: 3.716-14.024, P < 0.01) were independent risk factors of HCC progression. ROC of AFP for diagnosis of HCC was 0.746 (95%CI: 0.674-0.818). A cutoff value of AFP of 9.00 ug/L had a sensitivity of 0.609, and specificity of 0.818 for diagnosing HCC. CONCLUSION: Age ≥ 60 years, smoking history, family history of HCC, lamivudine resistance, HBV DNA negative, FBG ≥ 6.16 mmol/L were risk factors of HCC progression. Serum AFP had limited diagnostic value for HCC.

Primary bone anaplastic lymphoma kinase positive anaplastic large-cell lymphoma: A case report and review of the literature.

BACKGROUND: Primary bone lymphoma (PBL) is an uncommon extranodal disease that represents approximately 1%-3% of lymphomas. Anaplastic lymphoma kinase (ALK) positive anaplastic large-cell lymphoma (ALCL) is an extremely rare type of PBL. The aim of this report is describe the symptoms, diagnosis, and treatment of primary bone ALK-positive ALCL. CASE SUMMARY: A 66-year-old man presented to our hospital with neck and shoulder pain and intermittent fever that lasted for 1 mo. After extensive evaluation, positron emission tomography-computed tomography (CT) examination showed multiple osteolytic bone lesions without other sites lesions. CT-guided biopsy of the T10 vertebral body was performed, and the pathology results showed that neoplastic cells were positive for ALK-1, CD30, and CD3. A diagnosis of primary bone ALK positive ALCL was ultimately made. The patient was in partial response after four cycle soft cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy, and we planned to repeat the biopsy and radiological examination after completion of the fifth cycle of therapy. CONCLUSION: Primary bone ALK positive ALCL is a rare disease and physicians should keep in mind that ALCL can present with isolated osseous involvement without nodal involvement, and lymphoma should be considered in the differential diagnosis of primary bone lesions.

A rapid screening model for early predicting novel coronavirus pneumonia in Zhejiang Province of China: a multicenter study.

Novel coronavirus pneumonia (NCP) has been widely spread in China and several other countries. Early finding of this pneumonia from huge numbers of suspects gives clinicians a big challenge. The aim of the study was to develop a rapid screening model for early predicting NCP in a Zhejiang population, as well as its utility in other areas. A total of 880 participants who were initially suspected of NCP from January 17 to February 19 were included. Potential predictors were selected via stepwise logistic regression analysis. The model was established based on epidemiological features, clinical manifestations, white blood cell count, and pulmonary imaging changes, with the area under receiver operating characteristic (AUROC) curve of 0.920. At a cut-off value of 1.0, the model could determine NCP with a sensitivity of 85% and a specificity of 82.3%. We further developed a simplified model by combining the geographical regions and rounding the coefficients, with the AUROC of 0.909, as well as a model without epidemiological factors with the AUROC of 0.859. The study demonstrated that the screening model was a helpful and cost-effective tool for early predicting NCP and had great clinical significance given the high activity of NCP.

Soluble eggshell membrane protein-loaded chitosan/fucoidan nanoparticles for treatment of defective intestinal epithelial cells.

Soluble eggshell membrane protein (SEP) and polysaccharides extracted from algae exhibited immunomodulatory, presenting a potential for inflammatory bowel disease (IBD) treatment. However, the bioavailability of proteins is limited because of harsh gastrointestinal pH environment, enzymatic degradation and limitation of intestinal epithelial transport. This study investigates the release of SEP from chitosan/fucoidan nanoparticles (CS/F NPs) and evaluates the protective effect of released SEP on intestinal epithelial cells (IECs) damage. The SEP was successfully extracted and encapsulated by CS/F NPs. When the SEP/CS/F weight ratio was 0.2/3/1, the NPs were spherical with 100 nm in diameter and 10 mV in zeta potential. The NPs were stable in simulated gastric acid (pH = 1.2), and released 50% of SEP when disintegrated in imitating intestinal environment (pH = 7.4). The SEP-CS/F NPs had good biocompatibility and presented high antioxidant activities. Using co-culture Caco-2 and RAW264.7 cells for immunomodulatory assessment, the SEP-CS/F NPs effectively reduced the amount of NO and inhibited the TNF-α and IL-6 production. Moreover, the SEP-CS/F NPs could protect the IECs from disruption caused by lipopolysaccharide (LPS) evidenced by measuring the transepithelial electrical resistance and paracellular permeability of fluorescein isothiocyanate-dextran. Briefly, the CS/F NPs are potential carriers for SEP delivery to ameliorate LPS-induced intestinal epithelial inflammation.

EGFR-targeted photodynamic therapy by curcumin-encapsulated chitosan/TPP nanoparticles.

BACKGROUND: Photodynamic therapy (PDT) is an effective therapy for cancers and is a minimally invasive therapy with low dark toxicity and limited side effects. PDT employs the combination of photosensitizers with a specific light source to produce reactive oxygen species (ROS) to damage tumor cells. METHODS: We fabricated nanoparticles encapsulating curcumin through crosslinking chitosan and tripolyphosphate (TPP). Additionally, the chitosan was conjugated to epidermal growth factor in order to target the epidermal growth factor receptor (EGFR), overexpressed on cancer cells. To investigate PDT using fabricated nanoparticles, we measured cell viabilities and ROS production in relation to EGFR-overexpressing gastric cancer cells and non-cancer gastric cells. RESULTS: The targeting nanoparticles displayed a superior PDT effect in the cancer cell, with a resultant approximately fourfold decrease in the IC50. The PDT mechanism of curcumin-encapsulated nanoparticles is further identified as the generation of 1O2, the major pathway in PDT. CONCLUSION: These curcumin-encapsulated chitosan/TPP nanoparticles are a promising targeted-PDT against EGFR-overexpressing cancers.

Peliosis hepatis: 2 case reports of a rare liver disorder and its differential diagnosis.

RATIONALE: Peliosis hepatis (PH) is a rare tumor-like liver lesion composed of multiple blood-filled cavities within the liver parenchyma. It is hard to differentiate PH from other liver lesions by imaging, such as carcinoma, metastases, or abscess. PATIENT CONCERNS: Here, we reported 2 cases that presented with liver lesions under ultrasound and computed tomography (CT) scanning, without any history of liver diseases or drug usage traced back. DIAGNOSES: Liver biopsy and laparoscopy were processed, and the lesions were eventually diagnosed as PH by histopathology, which microscopically presented with multiple sinusoidal dilatations with blood-filled cystic spaces. INTERVENTIONS: After the liver biopsy or laparoscopy, the patients were discharged and followed up in the clinic. OUTCOMES: Both patients were followed up for at least 1 year with good recovery. LESSONS: PH should always be recognized in the differentiation of liver lesions, particularly indistinctive lesion(s) without any history of liver-related diseases.

Tumor Necrosis Factor α-Dependent Neutrophil Priming Prevents Intestinal Ischemia/Reperfusion-Induced Bacterial Translocation.

BACKGROUND: Intestinal ischemia/reperfusion (I/R) causes barrier impairment and bacterial influx. Protection against I/R injury in sterile organs by hypoxic preconditioning (HPC) had been attributed to erythropoietic and angiogenic responses. Our previous study showed attenuation of intestinal I/R injury by HPC for 21 days in a neutrophil-dependent manner. AIM: To investigate the underlying mechanisms of neutrophil priming by HPC, and explore whether adoptive transfer of primed neutrophils is sufficient to ameliorate intestinal I/R injury. METHODS: Rats raised in normoxia (NM) and HPC for 3 or 7 days were subjected to sham operation or superior mesenteric artery occlusion for I/R challenge. Neutrophils isolated from rats raised in NM or HPC for 21 days were intravenously injected into naïve controls prior to I/R. RESULTS: Similar to the protective effect of HPC-21d, I/R-induced mucosal damage was attenuated by HPC-7d but not by HPC-3d. Naïve rats reconstituted with neutrophils of HPC-21d rats showed increase in intestinal phagocytic infiltration and myeloperoxidase activity, and barrier protection against I/R insult. Elevated free radical production, and higher bactericidal and phagocytic activity were observed in HPC neutrophils compared to NM controls. Moreover, increased serum levels of tumor necrosis factor α (TNFα) and cytokine-induced neutrophil chemoattractant-1 (CINC-1) were seen in HPC rats. Naïve neutrophils incubated with HPC serum or recombinant TNFα, but not CINC-1, exhibited heightened respiratory burst and bactericidal activity. Lastly, neutrophil priming effect was abolished by neutralization of TNFα in HPC serum. CONCLUSIONS: TNFα-primed neutrophils by HPC act as effectors cells for enhancing barrier integrity under gut ischemia.

Effect of basic fibroblast growth factor released from chitosan-fucoidan nanoparticles on neurite extension.

Exogenous growth factors are an integral part of an effective nerve tissue-engineering strategy. Basic fibroblast growth factor (bFGF) has a marked positive effect on angiogenesis and neuronal cell survival. However, bFGF is limited by its short half-life and easy degradation by enzymes. Therefore, in this study novel biodegradable chitosan-fucoidan nanoparticles (CS-F NPs) were designed to carry bFGFs and maintain their activities. The experimental results indicated that chitosan and fucoidan form stable nanoparticles approximately 200 nm in size via electrostatic interactions. Additionally, the effectiveness of nanoparticles is related to their chitosan:fucoidan weight ratio. The CS-F NPs control the release of bFGFs and protect bFGF from deactivation by heat and enzymes. In vitro cell studies demonstrate that CS-F NPs have no cytotoxicity to PC12 cells, as the concentration of NPs is 125 ng/ml. Moreover, the CS-F NPs significantly decrease the amount of bFGF needed for neurite extension. The cumulative release of bFGF from CS-F NPs at 24 h is 0.168 ng/ml, markedly lower than that in solution (4.2 ng/ml). Importantly, CS-F NPs are potential carriers for delivering bFGFs for nerve tissue engineering. Copyright © 2013 John Wiley & Sons, Ltd.

Preparation and characterization of antioxidant nanoparticles composed of chitosan and fucoidan for antibiotics delivery.

In this study, we developed novel chitosan/fucoidan nanoparticles (CS/F NPs) using a simple polyelectrolyte self-assembly method and evaluated their potential to be antioxidant carriers. As the CS/F weight ratio was 5/1, the CS/F NPs were spherical and exhibited diameters of approximately 230-250 nm, as demonstrated by TEM. These CS/F NPs maintained compactness and stability for 25 day in phosphate-buffered saline (pH 6.0-7.4). The CS/F NPs exhibited highly potent antioxidant effects by scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH), reducing the concentration of intracellular reactive oxygen species (ROS) and superoxide anion (O2-) in stimulated macrophages. The DPPH scavenging effect of CS/F NPs primarily derives from fucoidan. Furthermore, these CS/F NPs activated no host immune cells into inflammation-mediated cytotoxic conditions induced by IL-6 production and NO generation. The MTT cell viability assay revealed an absence of toxicity in A549 cells after exposure to the formulations containing 0.375 mg NPs/mL to 3 mg NPs/mL. Gentamicin (GM), an antibiotic, was used as a model drug for an in vitro releasing test. The CS/F NPs controlled the release of GM for up to 72 h, with 99% of release. The antioxidant CS/F NPs prepared in this study could thus be effective in delivering antibiotics to the lungs, particularly for airway inflammatory diseases.

FBXO7 Y52C polymorphism as a potential protective factor in Parkinson's disease.

Mutations in the F-box only protein 7 gene (FBXO7), the substrate-specifying subunit of SCF E3 ubiquitin ligase complex, cause Parkinson's disease (PD)-15 (PARK15). To identify new variants, we sequenced FBXO7 cDNA in 80 Taiwanese early onset PD patients (age at onset ≤ 50) and only two known variants, Y52C (c.155A>G) and M115I (c.345G>A), were found. To assess the association of Y52C and M115I with the risk of PD, we conducted a case-control study in a cohort of PD and ethnically matched controls. There was a nominal difference in the Y52C G allele frequency between PD and controls (p = 0.045). After combining data from China [1], significant difference in the Y52C G allele frequency between PD and controls (p = 0.012) and significant association of G allele with decreased PD risk (p = 0.017) can be demonstrated. Upon expressing EGFP-tagged Cys52 FBXO7 in cells, a significantly reduced rate of FBXO7 protein decay was observed when compared with cells expressing Tyr52 FBXO7. In silico modeling of Cys52 exhibited a more stable feature than Tyr52. In cells expressing Cys52 FBXO7, the level of TNF receptor-associated factor 2 (TRAF2) was significantly reduced. Moreover, Cys52 FBXO7 showed stronger interaction with TRAF2 and promoted TRAF2 ubiquitination, which may be responsible for the reduced TRAF2 expression in Cys52 cells. After induced differentiation, SH-SY5Y cells expressing Cys52 FBXO7 displayed increased neuronal outgrowth. We therefore hypothesize that Cys52 variant of FBXO7 may contribute to reduced PD susceptibility in Chinese.

Diagnostic feature of tuberculous peritonitis in patients with cirrhosis: A matched case-control study.

The aim of the present study was to compare the clinical characteristics of tuberculous peritonitis (TBP) and spontaneous bacterial peritonitis (SBP) in patients with cirrhosis. A retrospective, matched case-control study was conducted consisting of 12 patients with cirrhosis diagnosed with TBP between 2008 and 2011. Control subjects were patients with SBP. Clinical features and laboratory data were analyzed. Compared with SBP, TBP in patients with cirrhosis was frequently associated with extraperitoneal tuberculosis (25 vs. 0%), a more insidious onset (39.67±30.00 vs. 21.60±21.50 days; P<0.05), Child-Pugh classification B at onset (67 vs. 32%; P<0.05) and lymphopenia (0.67±0.22 vs. 1.19±0.41×109/l; P<0.01). Patients with TBP tended to have lymphocytic predominance in the peritoneal fluid (92%), while patients with SBP tended to have neutrophil predominance (68%). Compared with the SBP group, the TBP group had significantly higher ascitic protein, adenosine deaminase (ADA) and lactate dehydrogenase (LDH) levels. Ascitic protein levels were >25 g/l in 9 patients (75%) in the TBP group and in 2 patients (8%) in the SBP group; ascitic ADA activity levels were >27 U/l in 8 patients (67%) in the TBP group, but were not >27 U/l in any of the patients in the SBP group; ascitic LDH levels were >90 U/l in 10 patients (83%) in the TBP group and 5 patients (20%) in the SBP group. Therefore, the results of the present study indicate that TBP should be considered in cirrhotic patients with relevant clinical manifestations and characteristics of laboratory observations.

Mobilization of mesenchymal stem cells by stromal cell-derived factor-1 released from chitosan/tripolyphosphate/fucoidan nanoparticles.

Stromal cell-derived factor 1 (SDF-1) is an important chemokine in stem cell mobilization, and plays a critical role in the biological and physiological functions of mesenchymal stem cells (MSC). However, the use of SDF-1 in tissue regeneration is limited by two drawbacks, which are its short half-life and ready degradation by enzymes. This study investigates the release of SDF-1 from chitosan-based nanoparticles (NP) and evaluates the effect of released SDF-1 on the migration of MSC. Among the prepared chitosan-based NP a chitosan/tripolyphosphate/fucoidan (CS/TPP/F) NP is the most effective carrier for SDF-1 release. CS/TPP/F NP are spherical and effectively encapsulate SDF-1. The CS/TPP/F NP protected SDF-1 against proteolysis and heat treatment and controlled its release for up to 7 days. The concentration of released SDF-1 reached 23 ng ml(-1). According to in vitro experiments on cells the released SDF-1 retained its mitogenic activity, promoted the migration of MSC and enhanced PI3K expression. Biocompatible CS/TPP/F NP may be effective as carriers for the delivery and controlled release of SDF-1 to mobilize stem cells in tissue engineering applications.

Effects of laminin-coated carbon nanotube/chitosan fibers on guided neurite growth.

This study assesses the ability and potential of carbon nanotube (CNT)/chitosan to guide axon re-growth after nerve injuries. The CNT/chitosan fibers were produced via the coagulation and hydrodynamic focusing method. Fiber width and morphology were adjusted using such parameters as syringe pumping rate and the coagulant used. The CNT/chitosan fiber diameters were 50-300 µm for syringe pumping rates of 6-48 mL/h. Polyethylene glycol/NaOH (25%, w/w) solution was a suitable coagulant for forming fibers with small diameters. Physical property tests demonstrate that the CNT/chitosan composites had superior tensile strength and electrical conductivity compared with those of chitosan alone. The MTT and LDH tests reveal that CNT/chitosan composites were not cytotoxic. To improve the neural cell affinity of CNT/chitosan fibers, laminin was incorporated onto fiber surfaces via the oxygen plasma technique; cell adhesion ratio increased significantly from 3.5% to 72.2% with this surface modification. Immunofluorescence staining and SEM imaging indicate that PC12 cells adhered successfully and grew on the laminin (LN)-coated CNT/chitosan films and fibers. Experimental results show that PC12 grown on LN-coated CNT/chitosan fibers in vitro extend longitudinally oriented neurites in a manner similar to that of native peripheral nerves. With the inherent electrical properties of CNTs, oriented CNT/chitosan fibers have a potential for use as nerve conduits in nerve tissue engineering.

Simultaneous overexpression of Oct4 and Nanog abrogates terminal myogenesis.

Oct4 and Nanog are two embryonic stem (ES) cell-specific transcription factors that play critical roles in the maintenance of ES cell pluripotency. In this study, we investigated the effects of Oct4 and Nanog expression on the differentiation state of myogenic cells, which is sustained by a strong positive feedback loop. Oct4 and Nanog, either independently or simultaneously, were overexpressed in C2C12 myoblasts, and the expression of myogenic lineage-specific genes and terminal differentiation was observed by RT-PCR. Overexpression of Oct4 in C2C12 cultures repressed, while exogenous Nanog did not significantly alter C2C12 terminal differentiation. The expression of Pax7 was reduced in all Oct4-overexpressing myoblasts, and we identified a major Oct4-binding site in the Pax7 promoter. Simultaneous expression of Oct4 and Nanog in myoblasts inhibited the formation of myotubes, concomitant with a reduction in the endogenous levels of hallmark myogenic markers. Furthermore, overexpression of Oct4 and Nanog induced the expression of their endogenous counterparts along with the expression of Sox2. Using mammalian two-hybrid assays, we confirmed that Oct4 functions as a transcriptional repressor whereas Nanog functions as a transcriptional activator during muscle terminal differentiation. Importantly, in nonobese diabetic (NOD) severe combined immunodeficiency (SCID) mice, the pluripotency of C2C12 cells was conferred by overexpression of Oct4 and Nanog. These results suggest that Oct4 in cooperation with Nanog strongly suppresses the myogenic differentiation program and promotes pluripotency in myoblasts.