Liposome encapsulated polydopamine nanoparticles: Enhancing ferroptosis and activating hypoxia prodrug activity.

The short lifespan of active oxygen species and depressed O2 level during ferroptosis treatment in tumor cells weaken ferroptosis therapy. How to improve the utilization efficiency of active oxygen species generated in real time is pivotal for anticancer treatment. Herein, the tirapazamine (TPZ) loaded polydopamine-Fe nanoparticles (PDA-Fe-TPZ) was modified with unsaturated liposome (Lip), which was constructed to overcome the drawbacks of traditional ferroptosis therapy. The Lip@PDA-Fe-TPZ nanoliposomes can react with H2O2 to produce •OH by Fenton reaction, which then attacks Lip and transforms into radical intermediate (L•) and phospholipid peroxide radical (LOO•) to avoid the annihilation of •OH. The introduced Lip enhances lipid peroxidation and promotes oxygen consumption, resulting in increased hypoxia at tumor site. The introduced TPZ can be triggered by reductase in tumor cells under hypoxia, which can reduce to transient oxidative free radicals by reductase enzymes and destroy the structure of the surrounding biomacromolecules, thus achieving the synergistic treatment of ferroptosis and chemotherapy. In this work, we organically combined enhanced ferrroptosis with hypoxic activated chemotherapy to achieve efficient and specific tumor killing effect, which can sever as a promising treatment of cancer in the future.

Arabidopsis Protein Phosphatase PIA1 Impairs Plant Drought Tolerance by Serving as a Common Negative Regulator in ABA Signaling Pathway.

Reversible phosphorylation of proteins is a ubiquitous regulatory mechanism in vivo that can respond to external changes, and plays an extremely important role in cell signal transduction. Protein phosphatase 2C is the largest protein phosphatase family in higher plants. Recently, it has been found that some clade A members can negatively regulate ABA signaling pathways. However, the functions of several subgroups of Arabidopsis PP2C other than clade A have not been reported, and whether other members of the PP2C family also participate in the regulation of ABA signaling pathways remains to be studied. In this study, based on the previous screening and identification work of PP2C involved in the ABA pathway, the clade F member PIA1 encoding a gene of the PP2C family, which was down-regulated after ABA treatment during the screening, was selected as the target. Overexpression of PIA1 significantly down-regulated the expression of ABA marker gene RD29A in Arabidopsis protoplasts, and ABA-responsive elements have been found in the cis-regulatory elements of PIA1 by promoter analysis. When compared to Col-0, transgenic plants overexpressing PIA1 were less sensitive to ABA, whereas pia1 showed the opposite trait in seed germination, root growth, and stomatal opening experiments. Under drought stress, SOD, POD, CAT, and APX activities of PIA1 overexpression lines were lower than Col-0 and pia1, while the content of H2O2 was higher, leading to its lowest survival rate in test plants, which were consistent with the significant inhibition of the expression of ABA-dependent stress-responsive genes RD29B, ABI5, ABF3, and ABF4 in the PIA1 transgenic background after ABA treatment. Using yeast two-hybrid and luciferase complementation assays, PIA1 was found to interact with multiple ABA key signaling elements, including 2 RCARs and 6 SnRK2s. Our results indicate that PIA1 may reduce plant drought tolerance by functioning as a common negative regulator involved in ABA signaling pathway.

The therapeutic window of intravenous immunoglobulin (IVIG) and its correlation with clinical outcomes in Kawasaki disease: a systematic review and meta-analysis.

BACKGROUND: The optimal therapeutic window to start intravenous immunoglobulin (IVIG) for Kawasaki disease (KD) is highly debatable. We aimed to summarize the existing literature to evaluate the therapeutic window of IVIG treatment and its correlation with clinical outcomes in KD patients. METHODS: We searched the databases from inception to August 26, 2022, without language restrictions. The primary outcomes were initial IVIG resistance and coronary artery lesions (CALs) in acute phase. Secondary outcome was CALs during 1-2 months of follow-up. RESULTS: 27 studies involving 41,139 patients were included in this study. Very low-quality evidence showed that the earlier IVIG treatment within 4 days had a higher IVIG-resistance rate (RR, 1.80; 95% CI, 1.50-2.15; P < .00001; I2 = 75%) than the late treatment. Very low-quality evidence showed that IVIG treatment for more than 7 days was associated with a higher risk of CALs in acute phase(RR, 0.57; 95% CI, 0.40-0.80; P = .001; I2 = 76%). There was a lower risk of CALs during 1-2 months follow-up for those who started IVIG administration within 10 days from the onset. CONCLUSIONS: Overall, IVIG treatment within 7 days of illness seems to be the optimal therapeutic window of IVIG. IVIG treatment within 7 days is found to be effective for reducing the risk of coronary artery lesions and cardiac sequelae in KD patients. The early IVIG treatment within 4 days should be vigilant for the IVIG resistance although large multi-center randomized trials with well design are needed.

SMPD1 expression profile and mutation landscape help decipher genotype-phenotype association and precision diagnosis for acid sphingomyelinase deficiency.

BACKGROUND: Acid sphingomyelinase deficiency (ASMD) disorder, also known as Niemann-Pick disease (NPD) is a rare genetic disease caused by mutations in SMPD1 gene, which encodes sphingomyelin phosphodiesterase (ASM). Except for liver and spleen enlargement and lung disease, two subtypes (Type A and B) of NDP have different onset times, survival times, ASM activities, and neurological abnormalities. To comprehensively explore NPD's genotype-phenotype association and pathophysiological characteristics, we collected 144 NPD cases with strict quality control through literature mining. RESULTS: The difference in ASM activity can differentiate NPD type A from other subtypes, with the ratio of ASM activity to the reference values being lower in type A (threshold 0.045 (4.45%)). Severe variations, such as deletion and insertion, can cause complete loss of ASM function, leading to type A, whereas relatively mild missense mutations generally result in type B. Among reported mutations, the p.Arg3AlafsX76 mutation is highly prevalent in the Chinese population, and the p.R608del mutation is common in Mediterranean countries. The expression profiles of SMPD1 from GTEx and single-cell RNA sequencing data of multiple fetal tissues showed that high expressions of SMPD1 can be observed in the liver, spleen, and brain tissues of adults and hepatoblasts, hematopoietic stem cells, STC2_TLX1-positive cells, mesothelial cells of the spleen, vascular endothelial cells of the cerebellum and the cerebrum of fetuses, indicating that SMPD1 dysfunction is highly likely to have a significant effect on the function of those cell types during development and the clinicians need pay attention to these organs or tissues as well during diagnosis. In addition, we also predicted 21 new pathogenic mutations in the SMPD1 gene that potentially cause the NPD, signifying that more rare cases will be detected with those mutations in SMPD1. Finally, we also analysed the function of the NPD type A cells following the extracellular milieu. CONCLUSIONS: Our study is the first to elucidate the effects of SMPD1 mutation on cell types and at the tissue level, which provides new insights into the genotype-phenotype association and can help in the precise diagnosis of NPD.

Unsaturated phospholipid modified FeOCl nanosheets for enhancing tumor ferroptosis.

Iron-dependent accumulation of reactive oxygen species (ROS) and lipid peroxidation play key roles in ferroptosis, which has been an attractive strategy to kill tumor cells. However, the rapid annihilation of hydroxyl radicals (˙OH) produced from the Fenton reaction has become a major obstacle in inducing lipid peroxidation in cells. In this study, we develop a nano-delivery system of unsaturated phospholipid (Lip) and polyacrylic acid (PAA) functionalized FeOCl nanosheets (FeOCl@PAA-Lip). In this system, the ˙OH radicals produced from the Fenton reaction between FeOCl nanosheets and endogenous H2O2 of tumor cells attack Lip on the nanosheets in situ to initiate the lipid peroxidation chain reaction, which not only realizes free radical conversion but also leads to the amplification of ROS and lipid peroxides, thus enhancing tumor ferroptosis. The in vitro and in vivo results confirmed that FeOCl@PAA-Lip nanosheets exhibited specific tumor cell-killing effects, good biocompatibility, long circulation time, low side effects, high tumor targeting and an excellent tumor inhibition rate (73%). The Lip functionalization strategy offers a paradigm of enhancing ferroptosis treatment by conversion of ˙OH/phospholipid radicals/lipid peroxyl radicals and strengthening lipid peroxidation.

Ferrocene-liposome-PEG: a robust ˙OH/lipid peroxide nano-converter for inducing tumor ferroptosis.

Ferroptosis induced by iron-dependent accumulation of lipid peroxides (LPOs) has received increasing attention in cancer therapy, especially chemodynamic therapy (CDT). However, the quick annihilation of hydroxyl radicals (˙OH) severely restricts the ˙OH/LPO conversion efficiency, which has become one of the key factors that influences the therapeutic efficacy of ferroptosis-based CDT. Herein, we designed a ˙OH/LPO nano-converter with a high LPO generation efficiency via loading ferrocene (Fc), a green Fenton catalyst, in the phospholipid bilayer of liposome-PEG (Fc-Lp-PEG). Under catalysis with Fc, the over-expressed H2O2 in tumors can be decomposed to ˙OH. The generated ˙OH in situ reacts with unsaturated lipids on the liposome, and is converted into LPOs, which spread the lipid peroxidation chain reaction to the remote membranes of cells and organelles, triggering efficient cancer cell ferroptosis. Systematic in vitro and in vivo therapeutic outcomes showed the high tumor inhibition ratio (74.0%) and the low side effects of Fc-Lp-PEG on 4T1 tumor-bearing mice. This novel strategy for improving the ˙OH/LPO conversion efficiency might provide new insights for the clinical development of ferroptosis-based CDT.

Prognostic value of PNN in prostate cancer and its correlation with therapeutic significance.

Prostate cancer (PCa) is the most common malignancy. New biomarkers are in demand to facilitate the management. The role of the pinin protein (encoded by PNN gene) in PCa has not been thoroughly explored yet. Using The Cancer Genome Atlas (TCGA-PCa) dataset validated with Gene Expression Omnibus (GEO) and protein expression data retrieved from the Human Protein Atlas, the prognostic and diagnostic values of PNN were studied. Highly co-expressed genes with PNN (HCEG) were constructed for pathway enrichment analysis and drug prediction. A prognostic signature based on methylation status using HCEG was constructed. Gene set enrichment analysis (GSEA) and the TISIDB database were utilised to analyse the associations between PNN and tumour-infiltrating immune cells. The upregulated PNN expression in PCa at both transcription and protein levels suggests its potential as an independent prognostic factor of PCa. Analyses of the PNN's co-expression network indicated that PNN plays a role in RNA splicing and spliceosomes. The prognostic methylation signature demonstrated good performance for progression-free survival. Finally, our results showed that the PNN gene was involved in splicing-related pathways in PCa and identified as a potential biomarker for PCa.

Circularly Polarized Antenna Array with Decoupled Quad Vortex Beams.

Achieving multiple vortex beams with different modes in a planar microstrip array is pivotal, yet still extremely challenging. Here, a hybrid method combining both Pancharatnam−Berry (PB) phase that is induced by the rotation phase and excitation phase of a feeding line has been proposed for decoupling two orthogonal circularly polarized vortex beams. Theoretical analysis is derived for array design to generate quad vortex beams with different directions and an arbitrary number of topological charges. On this basis, two 8 × 8 planar arrays were theoretically designed in an X band, which are with topological charges of l1 = −1, l2 = 1, l3 = −1, and l4 = 1 in Case I and topological charges of l1 = −1, l2 = 1, l3 = −1, and l4 = 1 in Case II. To further verify the above theory, the planar array in Case I is fabricated and analyzed experimentally. Dual-LP beams are realized by using rectangular patch elements with two orthogonally distributed feeding networks on different layers based on two types of feeding: proximity coupling and aperture coupling. Both the numerical simulation and experimental measurement results are in good agreement and showcase the corresponding quad-vortex-beam characteristics within 8~12 GHz. The array achieves a measured S11 < −10 dB and S22 < −10 dB bandwidth of more than 33.4% and 29.2%, respectively. In addition, the isolation between two ports is better than −28 dB. Our strategy provides a promising way to achieve large capacity and high integration, which is of great benefit to wireless and radar communication systems.

Pearson's patterns correlational of clinical risks at admissions with hospitalization outcomes during initial COVID-19 outbreak.

COVID-19 outbreaks have crushed our healthcare systems, which requires clinical guidance for the healthcare following the outbreaks. We conducted retrospective cohort studies with Pearson's pattern-based analysis of clinical parameters of 248 hospitalized patients with COVID-19. We found that dysregulated neutrophil densities were correlated with hospitalization duration before death (p = 0.000066, r = -0.45 for % neutrophil; p = 0.0001, r = -0.47 for neutrophil count). As such, high neutrophil densities were associated with mortality (p = 4.23 × 10-31 for % neutrophil; p = 4.14 × 10-27 for neutrophil count). These findings were further illustrated by a representative "second week crash" pattern and validated by an independent cohort (p = 5.98 × 10-11 for % neutrophil; p = 1.65 × 10-7 for neutrophil count). By contrast, low aspartate aminotransferase (AST) or lactate dehydrogenase (LDH) levels were correlated with quick recovery (p ≤ 0.00005). Collectively, these correlational at-admission findings may provide healthcare guidance for patients with COVID-19 in the absence of targeted therapy.

Evaluating the Quality of Reports About Randomized Controlled Trials of Acupuncture for Low Back Pain.

OBJECTIVE: This study aims to improve the reporting quality of randomized controlled trials (RCTs) by evaluating RCTs of acupuncture for low back pain (LBP) based on the CONSORT and STRICTA statements. METHODS: Literature from the Cochrane Library, Medline, Embase, Ovid, China National Knowledge Infrastructure (CNKI), WanFang database, and Chongqing Weipu (VIP) was systematically searched from 2010 to 2020. The general characteristics and the overall quality score (OQS) of the literature were evaluated by two investigators. The agreement between investigators was calculated using Cohen's kappa statistics. RESULTS: A total of 31 RCTs were extracted in the final analysis. Based on the CONSORT statement, the items "title and abstract", "background and objectives", "intervention", "outcomes", "statistical methods", "baseline data", "outcomes and estimation" and "interpretation" have a positive rate of greater than 80%. The items "implementation", "generalizability" and "protocol" have a positive rate of less than 30%. Based on the STRICTA statement, the items "style of acupuncture", "needle retention time", "number of treatment sessions", "frequency and duration of treatment" and "precise description of the control or comparator" have a positive rate of greater than 80%. The item "extent to which the treatment was varied" has a positive rate of less than 30%. The agreements among most items are determined to be moderate or good. CONCLUSION: The reporting quality of RCTs of acupuncture for LBP is moderate. Researchers should rigidly follow the CONSORT and STRICTA statements to enhance the quality of their studies.

Efficacy and safety of montelukast sodium combined with fluticasone in the treatment of adult bronchial asthma: A protocol for systematic review and meta-analysis.

BACKGROUND: Bronchial asthma (BA) is a chronic airway inflammatory disease with reversible airflow limitation as the main clinical manifestations, such as wheezing, cough, shortness of breath, chest tightness, etc, mediated by a variety of inflammatory cells, which can be recurrent. Clinical can improve symptoms, but cannot be cured; glucocorticoid is the most important first-line medication. Clinical practice has shown that montelukast sodium combined with fluticasone in the treatment of adult BA can improve clinical efficacy and reduce adverse reactions. The purpose of this study is to systematically study the efficacy and safety of montelukast sodium combined with fluticasone in the treatment of adult BA. METHODS: The Chinese databases (CNKI, VIP, Wanfang, Chinese Biomedical Database) and English databases (PubMed, the Cochrane Library, Embase, Web of Science) were searched by computer, for the randomized controlled clinical studies of montelukast sodium combined with fluticasone in the treatment of adult BA from establishment of database to October 2020. Two researchers independently extracted the relevant data and evaluated the quality of the literatures, and used RevMan5.3 software to conduct meta-analyze of the included literatures. RESULTS: This study assessed the efficacy and safety of montelukast sodium combined with fluticasone in the treatment of adult BA through total effective rate, pulmonary function (FEV1, FVC, PEF, FEV1/FVC), and adverse reactions. CONCLUSION: This study will provide reliable evidence-based evidence for the clinical application of montelukast sodium combined with fluticasone in the treatment of adult BA. OSF REGISTRATION NUMBER: DOI 10.17605/OSF.IO/CKQFM.

Vortex generation in the spin-orbit interaction of a light beam propagating inside a uniaxial medium: origin and efficiency.

It has been known that an optical vortex with a topological charge ±2 can be generated as a circularly polarized (CP) light beam propagates in a bulk uniaxial crystal, but its physical origin remains obscure which also hinders its practical applications. Here, through a rigorous full-wave analyses on the problem, we show that, as a CP beam possessing a particular spin (handedness) propagates inside a uniaxial crystal, two beams with opposite spins can be generated caused by the unique spin-sensitive light-matter interactions in the anisotropic medium. Flipping the spin can offer the light beam an vortex phase with a topological charge of ±2 owing to the Pancharatnam-Berry mechanism, with efficiency dictated by the material properties of the uniaxial medium and the topological structure of the beam itself. With its physical origin fully uncovered, we finally discuss how to improve the efficiency of such effect, and compare the mechanisms of vortex generations in different systems. Our findings not only provide deeper understandings on such an intriguing effect, but also shed light on other spin-orbit-interaction-induced effects.

MiR-218 Inhibits CSE-Induced Apoptosis and Inflammation in BEAS-2B by Targeting BRD4.

Background: Chronic obstructive pulmonary disease (COPD) is an age-related disease, and its incidence rate is increasing every year. MicroRNAs (miRNAs) play critical roles in the COPD process and function as key biomarkers or potential therapeutic targets for patients with COPD. However, the potential roles and functional effects of miR-218 in COPD remain undefined. Methods: The expression levels of miR-218 and bromodomain protein 4 (BRD4) were assessed by real-time quantitative polymerase chain reaction (RT-qPCR) or Western blot, respectively. In addition, a COPD cell model was established using cigarette smoke extract (CSE) in bronchial epithelial cell line (BEAS-2B). Enzyme-linked immunosorbent assay (ELISA) kit was applied to measure the concentrations of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-8 (IL-8) in cell supernatants of BEAS-2B cells. Moreover, cell apoptosis was examined by flow cytometry assay. The association relationship between miR-218 and BRD4 was confirmed by dual-luciferase reporter and RNA immunoprecipitation assay. Results: MiR-218 was downregulated in COPD and CSE-induced BEAS-2B cells, and it was positively correlated with forced expiratory volume in 1 second (FEV1) % in COPD patients. Mechanically, overexpression of miR-218 or knockdown of BRD4 mitigated apoptosis and inflammation in BEAS-2B cells induced by CSE. Additionally, overexpression of BRD4 weakened the miR-218-mediated effects on CSE-induced BEAS-2B cells. Conclusion: Overexpression of miR-218 inhibited CSE-induced apoptosis and inflammation in BEAS-2B cells by targeting BRD4 expression.

Rapamycin regulates the balance between cardiomyocyte apoptosis and autophagy in chronic heart failure by inhibiting mTOR signaling.

The progressive loss of cardiomyocytes caused by cell death leads to cardiac dysfunction and heart failure (HF). Rapamycin has been shown to be cardioprotective in pressure­overloaded and ischemic heart diseases by regulating the mechanistic target of rapamycin (mTOR) signaling network. However, the impact of rapamycin on cardiomyocyte death in chronic HF remains undetermined. Therefore, in the current study we addressed this issue using a rat myocardial infarction (MI)­induced chronic HF model induced by ligating the coronary artery. Following surgery, rats were randomly divided into six groups, including the sham­, vehicle­ and rapamycin­operated groups, at 8 or 12 weeks post­MI. A period of 4 weeks after MI induction, the rats were treated with rapamycin (1.4 mg­kg­day) or vehicle for 4 weeks. Cardiac function was determined using echocardiography, the rats were subsequently euthanized and myocardial tissues were harvested for histological and biochemical analyses. In the cell culture experiments with H9c2 rat cardiomyocytes, apoptosis was induced using angiotensin II (100 nM; 24 h). Cardiomyocyte apoptosis and autophagy were assessed via measuring apoptosis­ and autophagy­associated proteins. The activities of mTOR complex 1 (mTORC1) and mTORC2 were evaluated using the phosphorylation states of ribosomal S6 protein and Akt, respectively. The activity of the endoplasmic reticulum (ER) stress pathway was determined using the levels of GRP78, caspase­12, phospho­JNK and DDIT3. Echocardiographic and histological measurements indicated that rapamycin treatment improved cardiac function and inhibited cardiac remodeling at 8 weeks post­MI. Additionally, rapamycin prevented cardiomyocyte apoptosis and promoted autophagy at 8 weeks post­MI. Rapamycin treatment for 4 weeks inhibited the mTOR and ER stress pathways. Furthermore, rapamycin prevented angiotensin II­induced H9c2 cell apoptosis and promoted autophagy by inhibiting the mTORC1 and ER stress pathways. These results demonstrated that rapamycin reduced cardiomyocyte apoptosis and promoted cardiomyocyte autophagy, by regulating the crosstalk between the mTOR and ER stress pathways in chronic HF.

Daily 10 mg rivaroxaban as a therapy for ventricular thrombus related to left ventricular non-compaction cardiomyopathy: A case report.

RATIONALE: Left ventricular non-compaction cardiomyopathy (LVNC) is a rare heart disorder related to thrombosis. Anticoagulant therapy is suggested for the treatment of this disease. The success of the novel oral anticoagulant rivaroxaban as a treatment option for this disorder is unclear. PATIENT CONCERNS: A 43-year-old man who felt dizzy at rest was found to have an intraventricular thrombus. DIAGNOSES: The thrombus was confirmed by echocardiography. And LVNC was diagnosed by cardiac magnetic resonance (CMR) and echocardiography. INTERVENTIONS: He was prescribed a low dose (10 mg daily) of rivaroxaban as treatment. OUTCOMES: After 3 months, the thrombus diminished, and the manifestation disappeared. LESSONS: Low dose of rivaroxaban may serve as a viable option for anticoagulation therapy in LVNC patients, with large clinical trials needed to determine the best course of treatment.

Tumor-specific cytolysis caused by an E1B55K-attenuated adenovirus in nasopharyngeal carcinoma is augmented by cisplatin.

An E1B55K-attenuated adenovirus, dl1520, has been shown to replicate selectively in and lyse tumor cells. In this study, the antitumor activities of dl1520, alone or in combination with the chemotherapeutic agent cisplatin, were investigated in nasopharyngeal carcinoma (NPC) cells. The results demonstrated that dl1520 replicated in and destroyed NPC cells, and induced apoptosis in vitro. In a nude mouse xenograft model, dl1520 significantly inhibited the growth of NPC cell xenografts, and the viral replication was associated with tumor regression. Importantly, the antitumor activity of dl1520 was augmented by the addition of cisplatin both in vitro and in vivo, showing that dl1520 and cisplatin have a synergistic anti-NPC effect. These data suggest that dl1520 exerts an efficient anti-NPC activity through oncolysis and the induction of apoptosis, which is enhanced synergistically by cisplatin. These findings indicate that oncolytic viral therapeutics using the E1B55K-attenuated adenovirus dl1520 could be promising in the comprehensive treatment of NPC, especially in combination with platinum-based chemotherapy.

[Influence of selenium-rich rice on transformation of umbilical blood B lymphocytes by Epstein-Barr virus and Epstein-Barr virus early antigen expression].

BACKGROUND & OBJECTIVE: Selenium (Se), an antioxidant, is an essential trace element to human body. It can be used as an anti-aging agent and a tumor cell proliferation inhibitor. To further investigate the effect of selenium in cancer prevention, the authors observed the influence of Se-rich rice extract on the transformation of umbilical blood B lymphocytes stimulated by Epstein-Barr virus (EBV) and expression of EBV early antigen(EBV-EA) in Raji cells. METHODS: (1) Se-rich rice and general rice extract (dilution of 1:4 or 1:8) were added to mixture of EBV, and then umbilical blood mononuclear cells were added. Lymphoblasts transformation test was then performed. The inhibition rate of B lymphocytes transformation was calculated. (2) Raji cells stimulated by butyrate and croton oil were incubated with Se-rich rice extract. The EBV-EA positive expression rate and the inhibition rate were counted using indirect immunological flurescence method. RESULTS: The transformation of umbilical blood B lymphocytes stimulated by EBV was significantly inhibited by Se-rich rice extract at a concentration of 0.11 g/ml (1:8 diluted). The inhibition rate was 83.4% (P < 0.01), which was significantly higher than that of the control rice (63.1%) (P < 0.05). Se-rich rice extract showed significant inhibition on EBV-EA in Raji cells. As the extract concentration was at 0.016 microgram/ml, 0.078 g/ml, and 0.388 microgram/ml, the inhibition rates of EA were 2.85%, 12.88%, and 20.75%, respectively. CONCLUSION: The transformation of umbilical blood B lymphocytes stimulated by EB virus and expression of EBV-EA in Raji cells may be significantly inhibited by Se-rich rice extract, suggesting that Se-rich rice can be used for preventing nasopharyngeal carcinoma.

[A method to detect gene transfection efficacy by flow cytometry].

BACKGROUND & OBJECTIVE: Analysis of gene transfer and expression is conventionally inferred from the percentage of positive cells expressing reporter gene in total cells, referred as transfection rate, by investigators counting under a microscope or fluoroscope, which was called as manual counting. But in many cases, it is not accurate and easily influenced by the subjectivity of observer. This study was designed to seek a convenient method to assess objectively and accurately the efficacy of gene transfer and expression. METHODS: Hepatocellular carcinoma(HCC) HepG2 cells were infected with a recombinant adenovirus expressing green fluorescent protein(AdCMV/GFP) at a series of multiplicities of infection(MOIs). 24 h later, the transfection rates were assessed by manual counting under fluorescent microscope. Meanwhile, besides transfection rates, fluorescent indices(FIs) which indicated the efficiency of gene transfer and expression were analyzed by flow cytometry (FCM). Transfection efficiencies of AdCMV/GFP to HCC Hep3B, Bel7402, SMMC7721 cells and nasopharyngeal carcinoma CNE-2 cells were also tested by FCM. RESULTS: Although transfection rates by FCM were slightly higher than that by manual counting, both were logarithmic correlative with vector doses. The stirring was that FIs by FCM showed compellent linear correlation with vector doses (r = 0.9984, P < 0.001). The efficiency of gene transfer in other cells by FCM were similar to that in HepG2. CONCLUSION: The efficiency of gene transfer and expression in mammalian cells can be easily analyzed by flow cytometry, which is more sensitive, objective, and accurate than manual counting, especially in assessing the efficiency of multiple gene transfer (multi-copies per cell) and expression.