141 research outputs found

    Lox-dependent gene expression in transgenic plants obtained via Agrobacterium-mediated transformation

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    Lox sites of the Cre/lox recombination system from bacteriophage P1 were analyzed for their ability to affect on transgene expression when inserted upstream from a gene coding sequence adjacent to the right border (RB) of T-DNA. Wild and mutated types of lox sites were tested for their effect upon bar gene expression in plants obtained via Agrobacterium-mediated and biolistic transformation methods. Lox-mediated expression of bar gene, recognized by resistance of transgenic plants to PPT, occurred only in plants obtained via Agrobacterium-mediated transformation. RT-PCR analysis confirms that PPT-resistant phenotype of transgenic plants obtained via Agrobacterium-mediated transformation was caused by activation of bar gene. The plasmid with promoterless gus gene together with the lox site adjacent to the RB was constructed and transferred to Nicotiana tabacum as well. Transgenic plants exhibited GUS activity and expression of gus gene was detected in plant leaves. Expression of bar gene from the vectors containing lox site near RB allowed recovery of numerous PPT-resistant transformants of such important crops as Beta vulgaris, Brassica napus, Lactuca sativa and Solanum tuberosum. Our results demonstrate that the lox site sequence adjacent to the RB can be used to control bar gene expression in transgenic plants.Проанализирована способность lox-сайтов Cre/lox системы рекомбинации бактериофага Р1 влиять на экспрессию трансгенов при расположении этой последовательности непосредственно возле правого бордера (RB) перед кодирующей последовательностью гена. Нативная и мутированная последовательность lox-сайта были размещены в векторах для трансформации возле гена bar и проведена генетическая трансформация растений с помощью агробактерии и биолистическим методом. Lox-опосредованная экспрессия гена bar, обусловливающая устойчивость растений к фосфинотрицину, наблюдалась только у растений, которые получены с помощью агробактериальной трансформации. Методом РТ-ПЦР анализа подтверждено, что в трансгенных растениях, устойчивых к фосфинотрицину, происходит транскрипция гена bar. Сконструирован вектор, в котором ген gus и предшествующий ему lox-сайт размещены вблизи правого бордера, и проведена трансформация табака этим вектором. Экспрессия гена gus задетектирована в листьях трансгенных растений. Векторы, у которых последовательность lox-сайта предшествует гену bar возле правого бордера (RB-lox-bar), успешно использованы для получения устойчивых к фосфинотрицину трансгенных растений таких видов, как Beta vulgaris, Brassica napus, Lactuca sativa и Solanum tuberosum. Наши результаты подтверждают возможность использования последовательности lox-сайта возле правого бордера для контроля экспрессии гена bar в трансгенных растениях

    ТЕОРЕТИЧНІ ОСНОВИ ЗБЕРЕЖЕННЯ ЕКОЛОГІЧНОЇ РІВНОВАГИ

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    Much of the territory of Ukraine is in poor condition due to saturation of the environment by various toxic compounds. Human impacts that affect the level of environmental safety have been increasing constantly. The accumulation of waste has become one of the most important factors of environmental pollution, negative influence on all of its components. The generalized mathematical model of the process of ensuring ecological balance at the macro level – the state level has been devised. Objective function and resource constraints problem of minimizing the deviation from the ecological balance at a fixed time interval has been formulated.Значна частина території України перебуває у екологічно незадовільному стані через перенасичення навколишнього середовища різними токсичними сполуками. Постійно зростає техногенне навантаження, що впливає на рівень екологічної безпеки. Головним завданням на ближчий час має стати мінімізація підвищення рівня антропогенного впливу на довкілля Розроблена узагальнена математична модель процесу забезпечення екологічної рівноваги на макрорівні – рівні держави. Сформульована цільова функція та ресурсні обмеження задачі мінімізації відхилення від екологічної рівноваги на фіксованому часовому інтервалі

    Study of nerve fibers nature reinforcing duodenal contractions by electrical stimulation of sympathetic nerve

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    The subject of the article is to investigate the mechanism of increased reactions by electrical stimulation of the sympathetic nerve. Materials and methods: Experiments on dogs have shown that stimulant reactions during blockade of a-adrenergic by phentolamine and (3-adrenergic receptors with propranolol were completely eliminated by lizer-gol —the blocker of 5-HT12-receptors. Results: Infusion of lizergol did not influence on duodenal motor activity and the function of the vagus nerve. Conclusion: Effector neuron is found out to be serotonergic and its action is provided by 5-HT1 2 receptor

    Increase in the Synthesis of Polyfructan in the Cultures of Chicory “Hairy Roots” with Plant Natural Growth Regulators

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    Experiments were conducted to study the benefit of using the new plant growth regulators (PGRs) Ivin, Emistim, Biolan and Charkor in nutrient medium ½ MS for intensification of biomass growth and the increased synthesis of polyfructan (PF) in the cultures of chicory “hairy roots” (Cichorium intybus L.), obtained by Аgrobacterium rhizogenes-mediated transformation,. The best indexes of increased specific quantities of PF are observed after using Biolan at a concentration of 5.0 μL/L (up to 130 mg/g dry mass of roots) and Emistim at a concentration 2.5 µL/L (up to 220 mg/g dry mass of roots). The greatest stimulation of root growth activity was expressed on using the growth regulators Emistim, Ivin and Charkor, in concentrations between 2.5 and 10.0 µL/L, considerably raising the total quantity of PF: compared with the control the use of regulator Emistim showed a rise of up to 35 times, regulator Ivin showed an increase of up to 28 times and regulator Charkor showed an increase up to 7.0-7.5 times. The results thus obtained definitely prove the benefit of applying these regulators to increase the biomass growth and PF synthesis in the culture of chicory «hairy roots»

    Magnetic field penetration in MgB₂ single crystals: pinning and Meissner holes

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    The evolution of flux distribution in MgB₂ single crystals during their remagnetization was imaged with magneto-optical technique. Meissner holes, formed as the areas where the annihilation of vortices and antivortices takes place, were found at the boundary between oppositely magnetized parts of the crystal. Gradient of magnetic induction in the vicinity of Meissner holes was found to be enhanced. Finger-like structures of convex shape, formed during the penetration of magnetic flux inside the crystal, were observed and explained as an effect of inhomogeneous pinning and demagnetizing field redistribution in the sample

    Serum 25-hydroxyvitamin D, parathyroid hormone, calcium intake, and bone mineral density in Spanish adults

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    Summary Vitamin D insufficiency is very common among Spanish community-dwelling adult subjects. A threshold of serum 25(OH)D around 30 ng/ml would be necessary for the prevention of secondary hyperparathyroidism and hip bone loss in our population, regardless of the dairy calcium ingestion. Introduction This study aims to assess 25-hydroxyvitamin D?25(OH)D?status in Spanish adult subjects and to analyze its relationships with serum PTH levels, calcium intake, and bone mineral density (BMD). Methods A total of 1811 individuals (1154 postmenopausal women and 657 men) aged 44?93 years participated in the study. Serum 25(OH)D, intact parathyroid hormone (PTH), aminoterminal propeptide of type I collagen (P1NP), and Cterminal telopeptide of type I collagen (?-CTX) levels were measured by electrochemiluminescence. BMD was determined by dual x-ray absorptiometry (DXA) at lumbar spine, femoral neck, and total hip. Results Serum 25(OH)D levels were below 10, 20, and 30 ng/ml in 5, 40, and 83%of participants, respectively. There was a significant seasonal difference in mean serum 25(OH)D, with higher levels in summer?autumn. In multivariate analysis, 25(OH)D levels were negatively correlated with age, serum PTH and creatinine, body mass index, smoking, alcohol intake, and a number of chronic diseases, but positively with dairy calcium intake. The magnitude of the difference in serum PTH according to 25(OH)D quartiles was not influenced by calcium intake. A threshold of serum 25(OH)D around 30 ng/ml was observed for serum PTH and hip BMD. Conclusions Vitamin D insufficiency is very common among Spanish community-dwelling adult subjects. A threshold of serum 25(OH)D around 30 ng/ml would be necessary for the prevention of secondary hyperparathyroidism and hip bone loss in our population, regardless of the dairy calcium ingestion. Programs to improve vitamin D status may be required in our country

    Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

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    Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

    Improved risk stratification of patients with atrial fibrillation: an integrated GARFIELD-AF tool for the prediction of mortality, stroke and bleed in patients with and without anticoagulation.

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    OBJECTIVES: To provide an accurate, web-based tool for stratifying patients with atrial fibrillation to facilitate decisions on the potential benefits/risks of anticoagulation, based on mortality, stroke and bleeding risks. DESIGN: The new tool was developed, using stepwise regression, for all and then applied to lower risk patients. C-statistics were compared with CHA2DS2-VASc using 30-fold cross-validation to control for overfitting. External validation was undertaken in an independent dataset, Outcome Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF). PARTICIPANTS: Data from 39 898 patients enrolled in the prospective GARFIELD-AF registry provided the basis for deriving and validating an integrated risk tool to predict stroke risk, mortality and bleeding risk. RESULTS: The discriminatory value of the GARFIELD-AF risk model was superior to CHA2DS2-VASc for patients with or without anticoagulation. C-statistics (95% CI) for all-cause mortality, ischaemic stroke/systemic embolism and haemorrhagic stroke/major bleeding (treated patients) were: 0.77 (0.76 to 0.78), 0.69 (0.67 to 0.71) and 0.66 (0.62 to 0.69), respectively, for the GARFIELD-AF risk models, and 0.66 (0.64-0.67), 0.64 (0.61-0.66) and 0.64 (0.61-0.68), respectively, for CHA2DS2-VASc (or HAS-BLED for bleeding). In very low to low risk patients (CHA2DS2-VASc 0 or 1 (men) and 1 or 2 (women)), the CHA2DS2-VASc and HAS-BLED (for bleeding) scores offered weak discriminatory value for mortality, stroke/systemic embolism and major bleeding. C-statistics for the GARFIELD-AF risk tool were 0.69 (0.64 to 0.75), 0.65 (0.56 to 0.73) and 0.60 (0.47 to 0.73) for each end point, respectively, versus 0.50 (0.45 to 0.55), 0.59 (0.50 to 0.67) and 0.55 (0.53 to 0.56) for CHA2DS2-VASc (or HAS-BLED for bleeding). Upon validation in the ORBIT-AF population, C-statistics showed that the GARFIELD-AF risk tool was effective for predicting 1-year all-cause mortality using the full and simplified model for all-cause mortality: C-statistics 0.75 (0.73 to 0.77) and 0.75 (0.73 to 0.77), respectively, and for predicting for any stroke or systemic embolism over 1 year, C-statistics 0.68 (0.62 to 0.74). CONCLUSIONS: Performance of the GARFIELD-AF risk tool was superior to CHA2DS2-VASc in predicting stroke and mortality and superior to HAS-BLED for bleeding, overall and in lower risk patients. The GARFIELD-AF tool has the potential for incorporation in routine electronic systems, and for the first time, permits simultaneous evaluation of ischaemic stroke, mortality and bleeding risks. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier for GARFIELD-AF (NCT01090362) and for ORBIT-AF (NCT01165710)
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