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排序方式: 共有509条查询结果,搜索用时 109 毫秒
1.
Tetracycline-regulated gene expression following direct gene transfer into mouse skeletal muscle 总被引:7,自引:0,他引:7
Jyotsna Dhawan Thomas A. Rando Sarah L. Elson Hermann Bujard Helen M. Blau 《Somatic Cell and Molecular Genetics》1995,21(4):233-240
For most experimental and therapeutic applications of gene transfer, regulation of the timing and level of gene expression is preferable to constitutive gene expression. Among the systems that have been developed for pharmacologically controlled gene expression in mammalian cells, the bacterial tetracycline (tet)-responsive system has the advantage that it is dependent on a drug (tet) that is both highly specific and non-toxic. The tet-responsive system has been previously used to modulate expression of cell cycle regulatory proteins in cultured cells, reporter genes in plants and transgenic mice and reporter genes directly injected into the heart. Here we show that orally or parenterally administered tet regulates expression of tet-responsive plasmids injected directly into mouse skeletal muscle. Reporter gene expression was suppressed by two orders of magnitude in the presence of tet, and that suppression was reversed when tet was withdrawn. These data show that skeletal muscle offers an accessible and well characterized target tissue for tet-controlled expression of genesin vivo, suggesting applications to developmental studies and gene therapy. 相似文献
2.
Mathers ME Shrimankar J Scott DJ Charlton FG Griffith CD Angus B 《Journal of clinical pathology》2001,54(10):809-811
AIM: To determine whether the introduction of a standard reporting proforma has led to an improvement in the completeness of histopathology reports for breast cancer excision specimens. METHODS: A standard reporting proforma was designed using the Royal College of Pathologists' minimum dataset for breast cancer histopathology reports and the national histopathology reporting form of the National Health Service (NHS) breast screening programme. This was introduced into our department in June 1999, with reports generated from the proforma replacing the standard text reports. The pathological information contained in 50 text reports issued before the introduction of the proforma and 50 reports generated using the proforma was compared with the minimum dataset and NHS breast screening programme guidelines. RESULTS: A general improvement in documentation of individual pathological features was noted after introduction of the proforma. This was most significant in relation to documentation of features, such as microcalcification and ductal carcinoma in situ. In addition, important features such as tumour grade, tumour size, and hormone receptor status were documented more frequently in the proforma group. There was an overall increase in the number of reports regarded as complete after introduction of the proforma. CONCLUSIONS: The introduction of a standard proforma led to a significant improvement in the completeness of breast cancer histopathology reports in this centre, but continued vigilance is needed to ensure that standards continue to improve. 相似文献
3.
Mechanism of fluconazole resistance in Candida albicans biofilms: phase-specific role of efflux pumps and membrane sterols 总被引:15,自引:0,他引:15 下载免费PDF全文
Candida albicans biofilms are formed through three distinct developmental phases and are associated with high fluconazole (FLU) resistance. In the present study, we used a set of isogenic Candida strains lacking one or more of the drug efflux pumps Cdr1p, Cdr2p, and Mdr1p to determine their role in FLU resistance of biofilms. Additionally, variation in sterol profile as a possible mechanism of drug resistance was investigated. Our results indicate that parent and mutant strains formed similar biofilms. However, biofilms formed by double and triple mutants were more susceptible to FLU at 6 h (MIC = 64 and 16 microg/ml, respectively) than the wild-type strain (MIC > 256 microg/ml). At later time points (12 and 48 h), all the strains became resistant to this azole (MIC > or = 256 microg/ml), indicating lack of involvement of efflux pumps in resistance at late stages of biofilm formation. Northern blot analyses revealed that Candida biofilms expressed CDR and MDR1 genes in all the developmental phases, while planktonic cells expressed these genes only at the 12- and 48-h time points. Functionality of efflux pumps was assayed by rhodamine (Rh123) efflux assays, which revealed significant differences in Rh123 retention between biofilm and planktonic cells at the early phase (P = 0.0006) but not at later stages (12 and 48 h). Sterol analyses showed that ergosterol levels were significantly decreased (P < 0.001) at intermediate and mature phases, compared to those in early-phase biofilms. These studies suggest that multicomponent, phase-specific mechanisms are operative in antifungal resistance of fungal biofilms. 相似文献
4.
Kaushal Jyotsna Mahajan Pooja 《Bulletin of environmental contamination and toxicology》2022,108(3):437-442
Bulletin of Environmental Contamination and Toxicology - The dye removal using phytoremediation has demonstrated its potential to degrade many recalcitrant dyes. The kinetic investigations for... 相似文献
5.
6.
Candida biofilm resistance. 总被引:2,自引:0,他引:2
Device-related infections in most nosocomial diseases can be traced to the formation of biofilms (microbial communities encased within polysaccharide-rich extracellular matrix) by pathogens on surfaces of these devices. Candida species are the most common fungi isolated from these infections, and biofilms formed by these fungal organisms are associated with drastically enhanced resistance against most antimicrobial agents. This enhanced resistance contributes to the persistence of this fungus despite antifungal therapy. Candida biofilms exhibit enhanced resistance against most antifungal agents, except echinocandins and lipid formulations of AmB. The expression of drug efflux pumps during the early phase of biofilm formation and alterations in membrane sterol composition contribute to resistance of these biofilms against azoles. Metabolic dormancy and ECM do not appear to contribute to resistance, although in a mixed-species biofilm, ECM does retard the diffusion of drugs across biofilm. These multifactorial mechanisms of resistance in fungal biofilms constitute a broad-spectrum defense that is effective against many types of antifungal agents, and represent a common theme present across microbial biofilms. 相似文献
7.
8.
Priyadarshi Soumyaranjan Sahu Jyotsna Seepana Sudarsini Padela Abani Kanta Sahu Swarna Subbarayudu Ankur Barua 《Revista do Instituto de Medicina Tropical de S?o Paulo》2014,56(3):253-258
Neurocysticercosis (NCC) is one of the major causes of childhood seizures
in developing countries including India and Latin America. In this study neurological
pediatric cases presenting with afebrile seizures were screened for anti-Cysticercus
antibodies (IgG) in their sera in order to estimate the possible burden of
cysticercal etiology. The study included a total of 61 pediatric afebrile seizure
subjects (aged one to 15 years old); there was a male predominance. All the sera were
tested using a pre-evaluated commercially procured IgG-ELISA kit (UB-Magiwell
Cysticercosis Kit ™). Anti-Cysticercus antibody in serum was positive in 23 of 61 (37.7%)
cases. The majority of cases with a positive ELISA test presented with generalized
seizure (52.17%), followed by complex partial seizure (26.08%), and simple partial
seizure (21.73%). Headaches were the major complaint (73.91%). Other presentations
were vomiting (47.82%), pallor (34.78%), altered sensorium (26.08%), and muscle
weakness (13.04%). There was one hemiparesis case diagnosed to be NCC. In this study
one child without any significant findings on imaging was also found to be positive
by serology. There was a statistically significant association found between the
cases with multiple lesions on the brain and the ELISA-positivity (p
= 0.017). Overall positivity of the ELISA showed a potential cysticercal etiology.
Hence, neurocysticercosis should be suspected in every child presenting with afebrile
seizure especially with a radio-imaging supportive diagnosis in tropical developing
countries or areas endemic for taeniasis/cysticercosis. 相似文献
9.
10.
Colorectal cancer (CRC) is a frequently diagnosed cancer and causing significant mortality in the patients. Metastasis caused by CRC is mainly responsible for this cancer-related deaths. Despite recent advancements in the treatment methods, prognosis remains poor. Therefore, effective treatment strategies need to be designed for successful management of this disease. Dehydroepiandrostenedione (DHEA), a 17-ketosteroid hormone produced by adrenal glands, gonads and including gastrointestinal tract is required for several physiological processes. Deregulation of DHEA levels leads to various disease conditions including cancer. In fact, several experimental studies strongly suggest that DHEA could be used as a chemopreventive agent against colon cancer. Prenlyation of certain membrane proteins such as phosphatase of regenerating liver-3 (PRL-3) is crucial for metastatic progression of colon cancer cells. The ability of DHEA to target prenylation pathway could be utilized to inhibit PRL-3 prenylation for successful prevention of CRC metastases. As DHEA is a widely consumed drug for various ailments, incorporation of DHEA in the treatment regimen may be beneficial to prevent or delay the occurrence of metastasis resulting from CRC. 相似文献