124 research outputs found

    Mechanism of Transcription Activation at the comG Promoter by the Competence Transcription Factor ComK of Bacillus subtilis

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    The development of genetic competence in Bacillus subtilis is regulated by a complex signal transduction cascade, which results in the synthesis of the competence transcription factor, encoded by comK. ComK is required for the transcription of the late competence genes that encode the DNA binding and uptake machinery and of genes required for homologous recombination. In vivo and in vitro experiments have shown that ComK is responsible for transcription activation at the comG promoter. In this study, we investigated the mechanism of this transcription activation. The intrinsic binding characteristics of RNA polymerase with and without ComK at the comG promoter were determined, demonstrating that ComK stabilizes the binding of RNA polymerase to the comG promoter. This stabilization probably occurs through interactions with the upstream DNA, since a deletion of the upstream DNA resulted in an almost complete abolishment of stabilization of RNA polymerase binding. Furthermore, a strong requirement for the presence of an extra AT box in addition to the common ComK-binding site was shown. In vitro transcription with B. subtilis RNA polymerase reconstituted with wild-type -subunits and with C-terminal deletion mutants of the -subunits was performed, demonstrating that these deletions do not abolish transcription activation by ComK. This indicates that ComK is not a type I activator. We also show that ComK is not required for open complex formation. A possible mechanism for transcription activation is proposed, implying that the major stimulatory effect of ComK is on binding of RNA polymerase.Peer reviewe

    Aerobic exercise in adolescents with obesity: preliminary evaluation of a modular training program and the modified shuttle test

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    BACKGROUND: Increasing activity levels in adolescents with obesity requires the development of exercise programs that are both attractive to adolescents and easily reproducible. The aim of this study was to develop a modular aerobic training program for adolescents with severe obesity, with a focus on variety, individual targets and acquiring physical skills. We report here the effects on aerobic fitness from a pilot study. Furthermore, we examined the feasibility of the modified shuttle test (MST) as an outcome parameter for aerobic fitness in adolescents with severe obesity. METHODS: Fifteen adolescents from an inpatient body weight management program participated in the aerobic training study (age 14.7 ± 2.1 yrs, body mass index 37.4 ± 3.5). The subjects trained three days per week for 12 weeks, with each session lasting 30–60 minutes. The modular training program consisted of indoor, outdoor and swimming activities. Feasibility of the MST was studied by assessing construct validity, test-retest reliability and sensitivity to change. RESULTS: Comparing pretraining and end of training period showed large clinically relevant and significant improvements for all aerobic indices: e.g. VO(2 peak )17.5%, effect size (ES) 2.4; W(max )8%, ES 0.8. In addition, a significant improvement was found for the efficiency of the cardiovascular system as assessed by the oxygen pulse (15.8%, ES 1.6). Construct validity, test-retest reliability and sensitivity to change of the MST were very good. MST was significantly correlated with VO(2 peak )(r = 0.79) and W(max )(r = 0.84) but not with anthropometric measures. The MST walking distance improved significantly by 32.5%, ES 2.5. The attendance rate at the exercise sessions was excellent. CONCLUSION: This modular, varied aerobic training program has clinically relevant effects on aerobic performance in adolescents with severe obesity. The added value of our aerobic training program for body weight management programs for adolescents with severe obesity should be studied with a randomized trial. This study further demonstrated that the MST is a reliable, sensitive and easy to administer outcome measure for aerobic fitness in adolescent body weight management trials

    An International Comparison of Presentation, Outcomes and CORONET Predictive Score Performance in Patients with Cancer Presenting with COVID-19 across Different Pandemic Waves.

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    Patients with cancer have been shown to have increased risk of COVID-19 severity. We previously built and validated the COVID-19 Risk in Oncology Evaluation Tool (CORONET) to predict the likely severity of COVID-19 in patients with active cancer who present to hospital. We assessed the differences in presentation and outcomes of patients with cancer and COVID-19, depending on the wave of the pandemic. We examined differences in features at presentation and outcomes in patients worldwide, depending on the waves of the pandemic: wave 1 D614G (n = 1430), wave 2 Alpha (n = 475), and wave 4 Omicron variant (n = 63, UK and Spain only). The performance of CORONET was evaluated on 258, 48, and 54 patients for each wave, respectively. We found that mortality rates were reduced in subsequent waves. The majority of patients were vaccinated in wave 4, and 94% were treated with steroids if they required oxygen. The stages of cancer and the median ages of patients significantly differed, but features associated with worse COVID-19 outcomes remained predictive and did not differ between waves. The CORONET tool performed well in all waves, with scores in an area under the curve (AUC) of >0.72. We concluded that patients with cancer who present to hospital with COVID-19 have similar features of severity, which remain discriminatory despite differences in variants and vaccination status. Survival improved following the first wave of the pandemic, which may be associated with vaccination and the increased steroid use in those patients requiring oxygen. The CORONET model demonstrated good performance, independent of the SARS-CoV-2 variants

    Recommendations for vaccination in patients with multiple sclerosis who are eligible for immunosuppressive therapies: Spanish consensus statement

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    Background: The recent development of highly effective treatments for multiple sclerosis (MS) and the potential risk of infectious complications require the development of prevention and risk minimisation strategies. Vaccination is an essential element of the management of these patients. This consensus statement includes a series of recommendations and practical scenarios for the vaccination of adult patients with MS who are eligible for highly effective immunosuppressive treatments. Methodology: A formal consensus procedure was followed. Having defined the scope of the statement, we conducted a literature search on recommendations for the vaccination of patients with MS and specific vaccination guidelines for immunosuppressed patients receiving biological therapy for other conditions. The modified nominal group technique methodology was used to formulate the recommendations. Development: Vaccination in patients who are candidates for immunosuppressive therapy should be considered before starting immunosuppressive treatment providing the patient's clinical situation allows. Vaccines included in the routine adult vaccination schedule, as well as some specific ones, are recommended depending on the pre-existing immunity status. If immunosuppressive treatment is already established, live attenuated vaccines are contraindicated. For vaccines with a correlate of protection, it is recommended to monitor the serological response in an optimal interval of 1-2 months from the last dose.Antecedentes: La reciente aparición de terapias de alta efectividad para el tratamiento de la esclerosis múltiple (EM), con potencial riesgo de complicaciones infecciosas, obliga plantear estrategias de prevención y minimización de riesgos. La vacunación constituye una parte esencial del manejo de estos pacientes. Este consenso recoge una serie de pautasy escenarios prácticos de vacunación en pacientes adultos con EM candidatos a tratamiento inmunosupresor. Metodología: Se llevó a cabo un consenso de tipo formal. Tras definir el alcance del documento, se realizó una búsqueda bibliográfica de vacunación en pacientes con EM, así como guías de vacunación específicas de pacientes inmunosuprimidosy en tratamiento biológico con otras enfermedades.Para la formulación de las recomendaciones se empleó la metodología de Modified Nominal Group Technique. Desarrollo: La vacunación en pacientes candidatos a tratamiento inmunosupresor se debe plantear antes de iniciar un tratamiento inmunosupresor siempre que la situación clínica del paciente lo permita. Se recomendarán tanto aquellas indicadas en el calendario vacunal del adulto, como algunas específicas, en función de la inmunidad previa. Si ya está instaurado el tratamiento inmunosupresor las vacunas vivas atenuadas estarán contraindicadas.Para aquellas vacunas que dispongan de un correlato de protección se recomienda monitorizar la respuesta serológica transcurridos de uno a2 meses de la última dosi

    Principles of genetic circuit design

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    Cells navigate environments, communicate and build complex patterns by initiating gene expression in response to specific signals. Engineers seek to harness this capability to program cells to perform tasks or create chemicals and materials that match the complexity seen in nature. This Review describes new tools that aid the construction of genetic circuits. Circuit dynamics can be influenced by the choice of regulators and changed with expression 'tuning knobs'. We collate the failure modes encountered when assembling circuits, quantify their impact on performance and review mitigation efforts. Finally, we discuss the constraints that arise from circuits having to operate within a living cell. Collectively, better tools, well-characterized parts and a comprehensive understanding of how to compose circuits are leading to a breakthrough in the ability to program living cells for advanced applications, from living therapeutics to the atomic manufacturing of functional materials.National Institute of General Medical Sciences (U.S.) (Grant P50 GM098792)National Institute of General Medical Sciences (U.S.) (Grant R01 GM095765)National Science Foundation (U.S.). Synthetic Biology Engineering Research Center (EEC0540879)Life Technologies, Inc. (A114510)National Science Foundation (U.S.). Graduate Research FellowshipUnited States. Office of Naval Research. Multidisciplinary University Research Initiative (Grant 4500000552

    Islet Endothelial Activation and Oxidative Stress Gene Expression Is Reduced by IL-1Ra Treatment in the Type 2 Diabetic GK Rat

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    Inflammation followed by fibrosis is a component of islet dysfunction in both rodent and human type 2 diabetes. Because islet inflammation may originate from endothelial cells, we assessed the expression of selected genes involved in endothelial cell activation in islets from a spontaneous model of type 2 diabetes, the Goto-Kakizaki (GK) rat. We also examined islet endotheliuml/oxidative stress (OS)/inflammation-related gene expression, islet vascularization and fibrosis after treatment with the interleukin-1 (IL-1) receptor antagonist (IL-1Ra)
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