Download the Free Unbound MEDLINE PubMed App to your smartphone or tablet.
Available for iPhone, iPad, iPod touch, and Android.
naked DNA [keywords]
- Loop mediated isothermal amplification (LAMP) test for specific and rapid detection of Brucella abortus in cattle. [JOURNAL ARTICLE]
- Vet Q 2014 Sep 15.:1-20.
Abstract Background: Brucella abortus, the major causative agent of abortion in cattle and a zoonotic pathogen needs to be diagnosed at an early stage. Loop mediated isothermal amplification (LAMP) test is easy to perform and also promising to be adapted at field level. Objective: To develop a LAMP assay for specific and rapid detection of B. abortus from clinical samples of cattle. Methods: LAMP primers were designed targeting BruAb2_0168 region using specific software tool and LAMP was optimized. The developed LAMP was tested for its specificity with 3 Brucella spp. and 11 other non Brucella spp. Sensitivity of the developed LAMP was also carried out with known quantity of DNA. Cattle whole blood samples and aborted fetal stomach contents were collected and used for testing with developed LAMP assay and results were compared with PCR. Results: The developed LAMP assay works at 61°C for 60 min and the detection limit was observed to be 100 fold more than the conventional polymerase chain reaction (PCR) that is commonly used for diagnosis of B. abortus. Clinical sensitivity and specificity of the developed LAMP assay was 100% when compared with RBPT and STAT. SYBR green dye I was used to visualize the result with naked eye. Conclusion: The novelty of the developed LAMP assay for specifically detecting B. abortus infection in cattle along with its inherent rapidness and high sensitivity can be employed for detecting this economically important pathogen of cattle at field level as well be exploited for screening of human infections.
- Efficient MDV & HVT Infection of QM7 cell line that does not contain latent MDV genome. [JOURNAL ARTICLE]
- Avian Pathol 2014 Sep 10.:1-26.
Marek's Disease virus (MDV, also known as Gallid herpesvirus 2, GaHV-2, MDV-1) causes oncogenic disease in chickens producing clinical symptoms that include lymphomas, visceral tumors, nerve lesions, and immunosuppression. MDV vaccines are widely used and mostly produced using primary cells: CEF (chicken embryo fibroblast), DEF (duck embryo fibroblast), CEK (chicken embryo kidney) or CKC (chicken kidney cells). An immortalized cell line that can be used to manufacture the virus has long been desired. In this report, we demonstrated that QM7 cells were susceptible to infection with either MDV or HVT (Herpesvirus of turkey, also known as Meleagrid herpesvirus 1, MeHV-1, MDV- 3). PCR analysis with primers amplifying selected MDV genes revealed that QM7 cells did not contain these sequences. However, MDV genes were detected in QT35 cells, which have been reported to harbor latent MDV virus. Transfection of naked MDV DNA initiated efficient infection of QM7 cells. In addition, QM7 cell lysate, clarified supernatant, and QM7 cell pellet infected with MDV were negative for reverse transcriptase activity, indicating absence of endogenous retrovirus. QM7 cells were also found to be free of other avian pathogens in chick embryo inoculation test. In vivo studies of MDV growing in QM7 cells showed the virus retained its pathogenicity and virulence. In ovo experiments demonstrated that both HVT and MDV propagated in QM7 cells did not interfere with hatchability of injected eggs, and viruses could be re-isolated from hatched chicks. The results suggest that QM7 could be a good host cell line for growing both MDV and HVT viruses.
- Nanocarrier mediated delivery of siRNA/miRNA in combination with chemotherapeutic agents for cancer therapy: Current progress and advances. [REVIEW]
- J Control Release 2014 Sep 7.
Chemotherapeutic agents have certain limitations when it comes to treating cancer, the most important being severe side effects along with multidrug resistance developed against them. Tumor cells exhibit drug resistance due to activation of various cellular level processes viz. activation of drug efflux pumps, anti-apoptotic defense mechanisms, etc. Currently, RNA interference (RNAi) based therapeutic approaches are under vibrant scrutinization to seek cancer cure. Especially small interfering RNA (siRNA) and micro RNA (miRNA), are able to knock down the carcinogenic genes by targeting the mRNA expression, which underlies the uniqueness of this therapeutic approach. Recent research focus in the regime of cancer therapy involves the engagement of targeted delivery of siRNA/miRNA in combinations with other therapeutic agents (such as gene, DNA or chemotherapeutic drug) for targeting permeability glycoprotein (P-gp), multidrug resistant protein 1 (MRP-1), B-cell lymphoma (BCL-2) and other targets that are mainly responsible for resistance in cancer therapy. RNAi-chemotherapeutic drug combinations have also been found to be effective against different molecular targets as well and can increase the sensitization of cancer cells to therapy several folds. However, due to stability issues associated with siRNA/miRNA suitable protective carrier is needed and nanotechnology based approaches have been widely explored to overcome these drawbacks. Furthermore, it has been univocally advocated that the co-delivery of siRNA/miRNA with other chemodrugs significantly enhances their capability to overcome cancer resistance compared to naked counterparts. The objective of this article is to review recent nanocarrier based approaches adopted for the delivery of siRNA/miRNA combinations with other anticancer agents (siRNA/miRNA/pDNA/chemodrugs) to treat cancer.
- Dew inspired breathing-based detection of genetic point mutation visualized by naked eye. [Journal Article]
- Sci Rep 2014.:6300.
A novel label-free method based on breathing-induced vapor condensation was developed for detection of genetic point mutation. The dew-inspired detection was realized by integration of target-induced DNA ligation with rolling circle amplification (RCA). The vapor condensation induced by breathing transduced the RCA-amplified variances in DNA contents into visible contrast. The image could be recorded by a cell phone for further or even remote analysis. This green assay offers a naked-eye-reading method potentially applied for point-of-care liver cancer diagnosis in resource-limited regions.
- Condensation of plasmid DNA enhances mitochondrial association in skeletal muscle following hydrodynamic limb vein injection. [Journal Article]
- Pharmaceuticals (Basel) 2014; 7(8):881-93.
Mitochondrial gene therapy and diagnosis have the potential to provide substantial medical benefits. However, the utility of this approach has not yet been realized because the technology available for mitochondrial gene delivery continues to be a bottleneck. We previously reported on mitochondrial gene delivery in skeletal muscle using hydrodynamic limb vein (HLV) injection. HLV injection, a useful method for nuclear transgene expression, involves the rapid injection of a large volume of naked plasmid DNA (pDNA). Moreover, the use of a condensed form of pDNA enhances the nuclear transgene expression by the HLV injection. The purpose of this study was to compare naked pDNA and condensed pDNA for mitochondrial association in skeletal muscle, when used in conjunction with HLV injection. PCR analysis showed that the use of condensed pDNA rather than naked pDNA resulted in a more effective mitochondrial association with pDNA, suggesting that the physicochemical state of pDNA plays a key role. Moreover, no mitochondrial toxicities in skeletal muscle following the HLV injection of condensed pDNA were confirmed, as evidenced by cytochrome c oxidase activity and mitochondrial membrane potential. These findings have the potential to contribute to the development for in vivo mitochondrial gene delivery system.
- Delivery of antisense oligonucleotides using poly(alkylene oxide)-poly(propylacrylic acid) graft copolymers in conjunction with cationic liposomes. [JOURNAL ARTICLE]
- J Control Release 2014 Sep 1.:103-112.
The clinical application of gene silencing is hindered by poor stability and low delivery efficiency of naked oligonucleotides. Here, we present the in vitro and in vivo behaviors of a rationally designed, ternary, self-assembled nanoparticle complex, consisting of an anionic copolymer, cationic DOTAP liposome, and antisense oligonucleotide (AON). The multifunctional copolymers are based on backbone poly(propylacrylic acid) (PPAA), a pH-sensitive hydrophobic polymer, with grafted poly(alkylene oxides) (PAOs) varying in extent of grafting and PAO chemistry. The nanoparticle complexes with PPAA-g-PAO copolymers enhance antisense gene silencing effects in A2780 human ovarian cancer cells. A greater amount of AON is delivered to ovarian tumor xenografts using the ternary copolymer-stabilized delivery system, compared to a binary DOTAP/AON complex, following intraperitoneal injection in mice. Further, intratumoral injection of the nanoparticle complexes containing 1mol% grafted PAO reduced tumoral bcl-2 expression by up to 60%. The data for complexes across the set of PAO polymers support a strong role for the hydrophilic-lipophilic balance of the graft copolymer in achieving serum stability and cellular uptake. Based upon these results, we anticipate that this novel nanoparticle delivery system can be extended to the delivery of plasmid DNA, siRNA, or aptamers for preclinical and clinical development.
- Beperminogene perplasmid for the treatment of critical limb ischemia. [JOURNAL ARTICLE]
- Expert Rev Cardiovasc Ther 2014 Sep 5.:1-12.
Therapeutic angiogenesis for the treatment of ischemic disease can be attained through the delivery of recombinant growth factor proteins, through gene transfer or cell transplantation. Gene transfer associated with adenovirus or naked plasmid DNAs has been extensively studied in clinical trials. An investigational product, beperminogene perplasmid, is the naked plasmid DNA encoding the cDNA of human HGF, which has potent angiogenic activity. In several clinical trials, beperminogene perplasmid showed favorable safety and efficacy profile in the treatment of critical limb ischemia. This article reviews the results of pre-clinical and clinical studies of beperminogene perplasmid in the treatment of critical limb ischemia caused by peripheral arterial disease and Buerger's disease.
- A Loop-Mediated Isothermal Amplification (LAMP) Assay for Early Detection of Schistosoma mansoni in Stool Samples: A Diagnostic Approach in a Murine Model. [Journal Article]
- PLoS Negl Trop Dis 2014 Sep; 8(9):e3126.
Human schistosomiasis, mainly due to Schistosoma mansoni species, is one of the most prevalent parasitic diseases worldwide. To overcome the drawbacks of classical parasitological and serological methods in detecting S. mansoni infections, especially in acute stage of the disease, development of cost-effective, simple and rapid molecular methods is still needed for the diagnosis of schistosomiasis. A promising approach is the loop-mediated isothermal amplification (LAMP) technology. Compared to PCR-based assays, LAMP has the advantages of reaction simplicity, rapidity, specificity, cost-effectiveness and higher amplification efficiency. Additionally, as results can be inspected by the naked eye, the technique has great potential for use in low-income countries.A sequence corresponding to a mitochondrial S. mansoni minisatellite DNA region was selected as a target for designing a LAMP-based method to detect S. mansoni DNA in stool samples. We used a S. mansoni murine model to obtain well defined stool and sera samples from infected mice with S. mansoni cercariae. Samples were taken weekly from week 0 to 8 post-infection and the Kato-Katz and ELISA techniques were used for monitoring the infection. Primer set designed were tested using a commercial reaction mixture for LAMP assay and an in house mixture to compare results. Specificity of LAMP was tested using 16 DNA samples from different parasites, including several Schistosoma species, and no cross-reactions were found. The detection limit of our LAMP assay (SmMIT-LAMP) was 1 fg of S. mansoni DNA. When testing stool samples from infected mice the SmMIT-LAMP detected S. mansoni DNA as soon as 1 week post-infection.We have developed, for the first time, a cost-effective, easy to perform, specific and sensitive LAMP assay for early detection of S. mansoni in stool samples. The method is potentially and readily adaptable for field diagnosis and disease surveillance in schistosomiasis-endemic areas.
- Development and Application of Loop-Mediated Isothermal Amplification Assays for Rapid Visual Detection of cry2Ab and cry3A Genes in Genetically-Modified Crops. [JOURNAL ARTICLE]
- Int J Mol Sci 2014; 15(9):15109-15121.
The cry2Ab and cry3A genes are two of the most important insect-resistant exogenous genes and had been widely used in genetically-modified crops. To develop more effective alternatives for the quick identification of genetically-modified organisms (GMOs) containing these genes, a rapid and visual loop-mediated isothermal amplification (LAMP) method to detect the cry2Ab and cry3A genes is described in this study. The LAMP assay can be finished within 60 min at an isothermal condition of 63 °C. The derived LAMP products can be obtained by a real-time turbidimeter via monitoring the white turbidity or directly observed by the naked eye through adding SYBR Green I dye. The specificity of the LAMP assay was determined by analyzing thirteen insect-resistant genetically-modified (GM) crop events with different Bt genes. Furthermore, the sensitivity of the LAMP assay was evaluated by diluting the template genomic DNA. Results showed that the limit of detection of the established LAMP assays was approximately five copies of haploid genomic DNA, about five-fold greater than that of conventional PCR assays. All of the results indicated that this established rapid and visual LAMP assay was quick, accurate and cost effective, with high specificity and sensitivity. In addition, this method does not need specific expensive instruments or facilities, which can provide a simpler and quicker approach to detecting the cry2Ab and cry3A genes in GM crops, especially for on-site, large-scale test purposes in the field.
- Kinetic and phenotypic analysis of CD8+ T cell responses after priming with alphavirus replicons and homologous or heterologous booster immunizations. [JOURNAL ARTICLE]
- J Virol 2014 Aug 13.
Alphavirus replicons are potent inducers of CD8(+) T cell responses and thus constitute an attractive vaccine vector platform for developing novel vaccines. However, the kinetics and memory phenotype of CD8(+) T cell responses induced by alphavirus replicons are not well characterized. Furthermore, little is known how priming with alphavirus replicons affects booster immune responses induced by other vaccine modalities. We demonstrate that a single immunization with an alphavirus replicon, administered as viral particles or naked DNA, induced an antigen-specific CD8(+) T cell response that had a sharp peak, followed by a rapid contraction. Administering a homologous boost before contraction had occurred did not further increase the response. In contrast, boosting after contraction when CD8(+) T cells had obtained a memory phenotype (based on CD127/CD62L expression), resulted in maintenance of CD8(+) T cells with a high recall capacity (based on CD27/CD43 expression). Increasing the dose of replicon particles promoted T effector memory (Tem) and inhibited T central memory (Tcm) development. Moreover, infection with a replicating alphavirus induced a similar distribution of CD8(+) T cells as the replicon vector. Lastly, the distribution of T cell subpopulations induced by a DNA-launched alphavirus replicon could be altered by heterologous boosts. For instance, boosting with a poxvirus vector (MVA) favored expansion of the Tem compartment. In summary, we have characterized the antigen-specific CD8(+) T cell response induced by alphavirus replicon vectors and demonstrated how it can be altered by homologous and heterologous boost immunizations.Alphavirus replicons are promising vaccine candidates against a number of diseases and are by themselves developed as vaccines against for example chikungunya virus infection. Replicons are also considered to be used for priming followed by booster immunization using different vaccine modalities. In order to rationally design prime-boost immunization schedules with these vectors, characterization of the magnitude and phenotype of CD8(+) T cell responses induced by alphavirus replicons is needed. Here, we demonstrate how factors such as timing and dose affect the phenotype of the memory T cell populations induced by immunization with alphavirus replicons. These findings are important for designing future clinical trials with alphaviruses, as they can be used to tailor vaccination regimens in order to induce a CD8(+) T cell response that is optimal for control and/or clearance of a specific pathogen.