86 research outputs found

    PF1: an A-T hook-containing DNA binding protein from rice that interacts with a functionally defined d(AT)-rich element in the oat phytochrome A3 gene promoter.

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    Phytochrome-imposed down-regulation of the expression of its own phytochrome A gene (PHYA) is one of the fastest light-induced effects on transcription reported in plants to date. Functional analysis of the oat PHYA3 promoter in a transfection assay has revealed two positive elements, PE1 and PE3, that function synergistically to support high levels of transcription in the absence of light. We have isolated a rice cDNA clone (pR4) encoding a DNA binding protein that binds to the AT-rich PE1 element. We tested the selectivity of the pR4-encoded DNA binding activity using linker substitution mutations of PE1 that are known to disrupt positive expression supported by the PHYA3 promoter in vivo. Binding to these linker substitution mutants was one to two orders of magnitude less than to the native PE1 element. Because this is the behavior expected of positive factor 1 (PF1), the presumptive nuclear transcription factor that acts in trans at the PE1 element in vivo, the data support the conclusion that the protein encoded by pR4 is in fact rice PF1. The PF1 polypeptide encoded by pR4 is 213 amino acids long and contains four repeats of the A-T hook DNA binding motif found in high-mobility group I-Y (HMGI-Y) proteins. In addition, PF1 contains an 11-amino acid-long hydrophobic region characteristic of HMG I proteins, its N-terminal region shows strong similarities to a pea H1 histone sequence and a short peptide sequence from wheat HMGa, and it shows a high degree of similarity along its entire length to the HMG Y-like protein encoded by a soybean cDNA, SB16. In vitro footprinting and quantitative gel shift analyses showed that PF1 binds preferentially to the PE1 element but also at lower affinity to two other AT-rich regions upstream of PE1. This feature is consistent with the binding characteristics of HMG I-Y proteins that are known to bind to most runs of six or more AT base pairs. Taken together, the properties of PF1 suggest that it belongs to a newly described family of nuclear proteins containing both histone H1 domains and A-T hook DNA binding domains

    Prognosis of venous thromboembolism in orthopaedic surgery or trauma patients and use of thromboprophylaxis.

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    BACKGROUND: There is scarce evidence about the prognosis of venous thromboembolism in patients undergoing orthopedic surgery and in patients suffering non-surgical trauma. METHODS: We used the RIETE database (Registro Informatizado de pacientes con Enfermedad Trombo Embólica) to compare the prognosis of venous thromboembolism and the use of thromboprophylaxis in patients undergoing different orthopedic procedures and in trauma patients not requiring surgery. RESULTS: From March 2001 to March 2015, a total of 61,789 patients were enrolled in RIETE database. Of these, 943 (1.52%) developed venous thromboembolism after elective arthroplasty, 445 (0.72%) after hip fracture, 1,045 (1.69%) after non-major orthopedic surgery and 2,136 (3.46%) after non-surgical trauma. Overall, 2,283 patients (50%) initially presented with pulmonary embolism. Within the first 90 days of therapy, 30 patients (0.66%; 95% CI 0.45-0.93) died from pulmonary embolism. The rate of fatal pulmonary embolism was significantly higher after hip fracture surgery (n = 9 [2.02%]) than after elective arthroplasty (n = 5 [0.53%]), non-major orthopedic surgery (n = 5 [0.48%]) or non surgical trauma (n = 11 [0.48%]). Thromboprophylaxis was more commonly used for hip fracture (93%) or elective arthroplasty (94%) than for non-major orthopedic surgery (71%) or non-surgical trauma (32%). Major bleeding was significantly higher after hip fracture surgery (4%) than that observed after elective arthroplasty (1.6%), non-major orthopedic surgery (1.5%) or non-surgical trauma (1.4%). CONCLUSIONS: Thromboprophylaxis was less frequently used in lower risk procedures despite the absolute number of fatal pulmonary embolism after non-major orthopedic surgery or non-surgical trauma, exceeded that observed after high risk procedures.pre-print441 K
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