Preparation and evaluation of nanoparticles loading plasmid DNAs inserted with siRNA fragments targeting c-Myc gene.

CONTEXT: c-Myc plays a key role in glioma cancer stem cell maintenance. A drug delivery system, nanoparticles loading plasmid DNAs inserted with siRNA fragments targeting c-Myc gene (NPs-c-Myc-siRNA-pDNAs), for the treatment of glioma, has not previously been reported. OBJECTIVE: NPs-c-Myc-siRNA-pDNAs were prepared and evaluated in vitro. MATERIALS AND METHODS: Three kinds of c-Myc-siRNA fragments were separately synthesized and linked with empty siRNA expression vectors in the mole ratio of 3:1 by T4 DNA ligase. The linked products were then separately transfected into Escherichia coli. DH5α followed by extraction with Endofree plasmid Mega kit (Qiagen, Hilden, Germany) obtained c-Myc-siRNA-pDNAs. Finally, the recombinant c-Myc-siRNA3-pDNAs, generating the highest transfection efficiency and the greatest apoptotic ability, were chosen for encapsulation into NPs by the double-emulsion solvent-evaporation procedure, followed by stability, transfection efficiency, as well as qualitative and quantitative apoptosis evaluation. RESULTS: NPs-c-Myc-siRNA3-pDNAs were obtained with spherical shape in uniform size below 150 nm, with the zeta potential about -18 mV, the encapsulation efficiency and loading capacity as 76.3 ± 5.4% and 1.91 ± 0.06%, respectively. The stability results showed that c-Myc-siRNA3-pDNAs remained structurally and functionally stable after encapsulated into NPs, and NPs could prevent the loaded c-Myc-siRNA3-pDNAs from DNase degradation. The transfection efficiency of NPs-c-Myc-siRNA3-pDNAs was proven to be positive. Furthermore, NPs-c-Myc-siRNA3-pDNAs produced significant apoptosis with the apoptotic rate at 24.77 ± 5.39% and early apoptosis cells observed. DISCUSSION AND CONCLUSION: Methoxy-poly-(ethylene-glycol)-poly-(lactide-co-glycolide) nanoparticles (MPEG-PLGA-NPs) are potential delivery carriers for c-Myc-siRNA3-pDNAs.

The Outcome-Present State Test Model of Clinical Reasoning to Promote Critical Thinking in Psychiatric Nursing Practice among Nursing Students: A Mixed Research Study.

This study determined whether teaching intervention using the outcome-present state test (OPT) clinical reasoning model can effectively improve critical thinking in nursing students during a psychiatry internship. In addition, it evaluates the experiences of the students using this model in clinical practice. METHODS: In this interventional study, 19 students were taught critical thinking skills using the OPT clinical reasoning model during a psychiatry clinical practice. Work-learning forms were used in daily 1 h individual and group discussions with students. The critical thinking disposition scale was completed by every student before and after the intervention. Moreover, the students were asked to the complete reflection experience forms. RESULTS: The average critical thinking disposition pre-intervention score was 95.21, whereas the average post-intervention score was 97.05, indicating an increase of 1.84. There was a significant increase in the fourth dimension of open-mindedness (z = -2.80, p < 0.01). The learning experience has been likened to a process of clearing the fog, and it involves the use of limited known conditions, thinking outside the box, and adaptation to complex care issues. CONCLUSION: Using the OPT clinical reasoning model as a teaching strategy during a psychiatric nursing internship significantly improved the open-mindedness dimension among the students. The student reflective experience of talking to teachers as peers helped students identify clues and reframe problems related to clinical care. Additionally, the students reported that this led to more harmonious interactions with their teachers.

A Novel Delivery System of RGD-HSA Loaded GEM/CUR Nanoparticles for the Treatment of Pancreatic Cancer Therapy.

Introduction: Pancreatic cancer is one of the most common malignant tumors and is characterized by high malignancy, occult incidence and poor prognosis. Traditional chemotherapy drugs have limited efficacy and strong side effects. Therefore, there is an urgent need for a better treatment of the malignancy. Methods: The prepared arginine glycine peptide (RGD)-human serum albumin (HSA)-Gemcitabine (GEM)/Curcumin (CUR) nanoparticles (NPs) were characterized for physicochemical properties, stability and in vitro release. Comparisons of HSA-GEM/CUR NPs and RGD-HSA-GEM/CUR NPs regarding tissue distributions and pharmacodynamics were also carried out using mice as the animal models. Results: Transmission electron micrographs showed that RGD peptide-conjugated HSA-NPs had an irregular surface, good dispersion (PDI=0.139±0.03) and a uniform size distribution (Mean PS=115.6±5.7 nm). The ζ-potential was -17.3 mV. As regards in vitro release, non RGD modified NPs showed a faster release rate in 24 hours, yielding a release amount of 75% for GEM and 72% for CUR. RGD-HSA-GEM/CUR NPs exhibited 67% of accumulated release of GEM (63% for CUR) in 24 hours. This may be due to the HSA chain covering the surface of NPs, which hindered the drug release. The cytotoxicity of GEM/CUR co-loaded NPs was significantly higher than that of single-drug NPs (P < 0.05). In vivo study results indicated that RGD-HSA-GEM/CUR NPs had notable targeting effect on subcutaneous tumors, with a potential to actively deliver drugs to tumor tissues. Conclusion: In this study, we prepared RGD-HSA-GEM/CUR NPs that had both good water solubility and tumor-targeting property. The results also showed that the RGD modified NPs had advantages in increasing GEM/CUR concentration at tumor sites and reducing its distribution in peripheral organs.

The Relationship between Depressive Symptoms, Rumination, and Suicide Ideation in Patients with Depression.

The relationship between suicide and rumination in depression is a recent topic of attention in mental health. The purpose of this study was to investigate the relationship between demographic variables, depressive symptoms, rumination, and suicide ideation in patients with depression, as well as the predictors of suicide ideation. RESEARCH DESIGN: A cross-sectional study of 95 subjects with depression recruited intentionally from the psychiatric ward of Tzu Chi Hospital. The questionnaire included demographic data, the Beck Depression Inventory-II, the Ruminative Response Scale, and the Beck Scale for Suicide Ideation. Independent sample t-test, Pearson product difference correlation, and the stepwise regression test were adopted for data analysis. RESULTS: Age (r = -0.41, p < 0.01), age at diagnosis (r = -0.34, p < 0.01), and sleep duration (r = -0.25, p < 0.05) were negatively correlated with rumination-reflection. The depressive symptoms (r = 0.72, p < 0.01) were positively correlated with rumination, whereas rumination (r = 0.57, p < 0.01) and suicide ideation were positively correlated. Depressive symptoms and rumination could predict suicide ideation, and the effective explanatory power reached 60%. CONCLUSIONS: If the patient with depression was younger or the patient was diagnosed at a younger age, the depressive symptoms of the reflection subscale of rumination thinking and suicide ideation were more serious. Our results indicate that clinicians who care for patients with depression should be aware of rumination and its impact on suicide ideation, specifically in younger patients.

Helicobacter pylori induces promoter hypermethylation and downregulates gene expression of IRX1 transcription factor on human gastric mucosa.

BACKGROUND AND AIM: Gene silence of IRX1 tumor suppressor by promoter CpG methylation combined with loss of heterozygosity (LOH) has been identified in human gastric cancer. This study investigated the association between methylation of IRX1 and Helicobacter pylori infection in gastric mucosa tissues and cell line. METHODS: IRX1 methylation was studied by methylation specific polymerase chain reaction (MSP) and bisulfate sequencing polymerase chain reaction (BSP) methods in gastric mucosa tissues from H. pylori-positive chronic gastritis patients or H. pylori-negative chronic gastritis patients. Promoter activity, methylation status and gene expressing level of IRX1 were evaluated by persistent infecting H. pylori on human gastric cells GES-1 in vitro. Electron microscopy was used to observe the effect of H. pylori infection on GES-1 gastric mucosa cells. RESULTS: The methylation level of IRX1 promoter in H. pylori positive chronic gastritis and H. pylori negative chronic gastritis was 55.30%±13.17 versus 5.20%±6.31, respectively (P<0.01). H. pylori infection stimulated increased microvillus, and mucous secretion on GES-1 cells. Infection of H. pylori induced IRX1 promoter methylation and downregulation of the promoter activity as well as gene expression significantly. CONCLUSIONS: This study firstly demonstrated that H. pylori infection contributes to IRX1 promoter methylation on gastric mucosa.

[Establishment of experimental angiogenic models with applications of quantitative digital image analysis].

OBJECTIVE: To establish experimental models for tumor neovascularization and to apply quantitative digital imaging analysis in the study. METHODS: An endothelial tube formation model was established by human umbilical vein endothelial cells (HUVECs). A vasculogenic mimicry model was established by SGC-7901 gastric cancer cell line. Fertilized eggs were used to establish a chorioallantoic membrane angiogenesis model. Using gene transfection experiment, IRX1 tumor suppressor gene was chosen as a therapeutic target. Image Pro Plus (IPP) analysis software was used for digital vascular images analysis with parameters including points, lines, angles and integral absorbance (IA) for the tubular formation or vasculogenic mimicry. RESULTS: Digital image analysis by IPP showed that HUVEC tubular formation was significantly inhibited in IRX1 transfectant, compared with controls. The tubular numbers in three groups were 12.80 +/- 3.83, 29.00 +/- 5.34 and 28.20 +/- 4.32 (P<0.01). The connection points of tubules in three groups were 13.20 +/- 2.59, 25.00 +/- 2.24 and 24.60 +/- 3.21 (P<0.01). The tubular lengths of three groups were (821.5 +/- 12.5), (930.9 +/- 13.5) and (948.4 +/- 18.1) microm (P=0.022). The IA values of PAS stain in three groups were 3606 +/- 363, 14 200 +/- 1251 and 15 043 +/- 1220 (P<0.01). In chick chorioallantoic membrane model, the angular numbers of tubules in three groups were 6.41 +/- 2.60, 10.27 +/- 2.65 and 9.18 +/- 1.99 (P<0.01). CONCLUSIONS: The endothelial tube formation model, vasculogenic mimicry model and chorioallantoic membrane angiogenesis model are useful for gene therapy and drug screening with targeting neoplastic vascularization. Professional image analysis software may greatly facilitate the quantitative analysis of tumor neovascularization.

[Discovery and verification of matrix gla protein, a TNM staging and prognosis-related biomarker for gastric cancer].

OBJECTIVE: To analyze microarray datasets deposited in the public database and to identify TNM associated genes in gastric cancers. METHODS: Microarray datasets of gastric cancer were selected from GEO database. Differentially expressed genes related to TNM staging were evaluated by significant analysis of the microarray using MultiExperiment Viewer (MEV) platform. Candidate gene expressions in gastric cancer tissues and cell lines were verified by reverse transcriptase polymerase chain reaction (RT-PCR), quantitative RT-PCR, Western blot and immunohistochemistry. RESULTS: GES4007 dataset was re-analyzed leading to the identification of 14 genes associated with TNM staging. Over-expression of matrix gla protein (MGP) was confirmed in gastric cancer cell lines and tumor tissues by quantitative RT-PCR, Western blot and immunohistochemistry. Increased MGP expression was found in 22 of 54 cases of (40.7%) gastric cancer specimens compared to the normal gastric tissues. The up-regulation of MGP mRNA expression closely correlated with TNM stage (P = 0.001) and prognosis (P = 0.006). CONCLUSIONS: Public databases of microarray studies are the valuable resources for data mining. MGP has been identified and confirmed as a novel biomarker for the TNM stage and prognosis of gastric cancer.

Relationship between UGT1A1*6/*28 polymorphisms and severe toxicities in Chinese patients with pancreatic or biliary tract cancer treated with irinotecan-containing regimens.

PURPOSE: The aim of this retrospective study was to investigate the relationship between UGT1A1 polymorphisms and toxicities in Chinese patients with pancreatic or biliary tract cancer receiving irinotecan-containing regimens as the second- or third-line chemotherapy. PATIENTS AND METHODS: A total of 36 patients with unresectable pancreatic cancer and 12 patients with unresectable biliary tract cancer were included. Approximately 33 patients were treated with FOLFIRI regimen, a chemotherapy regimen, where FOL stands for folinic acid, F for fluorouracil, and IRI for irinotecan (irinotecan 180 mg/m(2) at day 1, CF 200 mg/m(2) at day 1-2, 5-FU 400 mg/m(2) at day 1-2, followed by continuous infusion of 5-FU 600 mg/m(2) for 22 hours at day 1-2, every 2 weeks). The other 15 patients were treated with irinotecan monotherapy (180 mg/m(2), every 2 weeks). UGT1A1*6/*28 polymorphisms were detected by direct sequencing. RESULTS: The frequencies of GG, GA, AA genotypes for UGT1A1*6 were 70.8% (n=34), 25.0% (n=12), and 4.2% (n=2), respectively. And those of TA6/TA6, TA6/TA7, TA7/TA7 for UGT1A1*28 were 79.2% (n=38), 18.8% (n=9), and 2.0% (n=1), respectively. A total of 22 patients (45.8%) had grade III-IV neutropenia, and six patients (12.5%) experienced grade III-IV diarrhea. The incidence of grade III-IV neutropenia in patients with UGT1A1*6 GA or AA genotype was 71.4%, which was significantly higher than that with GG genotype (35.3%, P=0.022). No relationship was found between grade III-IV neutropenia and UGT1A1*28 polymorphism. The statistical analysis between grade III-IV diarrhea and UGT1A1*6/*28 polymorphisms was not conducted in view of the limited number of patients. CONCLUSION: In Chinese patients with pancreatic or biliary tract cancer administered irinotecan-containing regimens, those with UGT1A1*6 variant may have a high risk of severe neutropenia.