541 research outputs found

    Volcanic eruption forecasts from accelerating rates of drumbeat long-period earthquakes

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    Abstract Accelerating rates of quasiperiodic “drumbeat” long‐period earthquakes (LPs) are commonly reported before eruptions at andesite and dacite volcanoes, and promise insights into the nature of fundamental preeruptive processes and improved eruption forecasts. Here we apply a new Bayesian Markov chain Monte Carlo gamma point process methodology to investigate an exceptionally well‐developed sequence of drumbeat LPs preceding a recent large vulcanian explosion at Tungurahua volcano, Ecuador. For more than 24 hr, LP rates increased according to the inverse power law trend predicted by material failure theory, and with a retrospectively forecast failure time that agrees with the eruption onset within error. LPs resulted from repeated activation of a single characteristic source driven by accelerating loading, rather than a distributed failure process, showing that similar precursory trends can emerge from quite different underlying physics. Nevertheless, such sequences have clear potential for improving forecasts of eruptions at Tungurahua and analogous volcanoes

    Sources of dynamic variability in NF-κB signal transduction: a mechanistic model

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    The transcription factor NF-{kappa}B (p65/p50) plays a central role in the coordination of cellular responses by activating the transcription of numerous target genes. The precise role of the dynamics of NF-{kappa}B signalling in regulating gene expression is still an open question. Here, we show that besides external stimulation intracellular parameters can influence the dynamics of NF-{kappa}B. By applying mathematical modelling and bifurcation analyses, we show that NF-{kappa}B is capable of exhibiting different types of dynamics in response to the same stimulus. We identified the total NF-{kappa}B concentration and the I{kappa}B{alpha} transcription rate constant as two critical parameters that modulate the dynamics and the fold change of NF-{kappa}B. Both parameters might vary as a result of cell-to-cell variability. The regulation of the IκBα transcription rate constant, e.g. by co-factors, provides the possibility of regulating the NF-{kappa}B dynamics by crosstalk

    Removal of GIT lesions and the role of impedance of the injection solution—an innovative approach to known methods

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    In this work, for the first time, the specific impedances of various injection solutions as well as the surface and tissue impedance after injection of these solutions were analyzed and compared regarding the radio-frequency surgical cutting process. The impedances of 0.9% NaCl, 4% gelatine, 6% hydroxyethyl starch, 10% glycerol/5% fructose, 10% glucose, 5% and 20% albumin, blood, and blood plasma as well as aqua destillata have been tested in vitro. Even if EMR and ESD are routinely used in clinical practice, there is so far no easy, fast, and safe method to remove larger lesions en bloc. We show that the impedance of the injected solution shows to be a crucial factor for safe removal, especially of larger lesions (Ø > 20 mm) and more importantly in accordance with the requirements of oncology and pathology. KEY MESSAGES: Impedance is playing a crucial factor in the radio-frequency (RF)-surgery. With a higher Impedance there will be less current necessary to reach the aimed voltage. Injection solution Aqua destillata and 10% Glucose, show significantly higher Impedances. Higher impedances lead to less surgical related complications. Minor changes in existing method to improve patent safety

    Investigation of the key chemical structures involved in the anticancer activity of disulfiram in A549 non-small cell lung cancer cell line

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    © 2018 The Author(s). Background: Disulfiram (DS), an antialcoholism medicine, demonstrated strong anticancer activity in the laboratory but did not show promising results in clinical trials. The anticancer activity of DS is copper dependent. The reaction of DS and copper generates reactive oxygen species (ROS). After oral administration in the clinic, DS is enriched and quickly metabolised in the liver. The associated change of chemical structure may make the metabolites of DS lose its copper-chelating ability and disable their anticancer activity. The anticancer chemical structure of DS is still largely unknown. Elucidation of the relationship between the key chemical structure of DS and its anticancer activity will enable us to modify DS and speed its translation into cancer therapeutics. Methods: The cytotoxicity, extracellular ROS activity, apoptotic effect of DS, DDC and their analogues on cancer cells and cancer stem cells were examined in vitro by MTT assay, western blot, extracellular ROS assay and sphere-reforming assay. Results: Intact thiol groups are essential for the in vitro cytotoxicity of DS. S-methylated diethyldithiocarbamate (S-Me-DDC), one of the major metabolites of DS in liver, completely lost its in vitro anticancer activity. In vitro cytotoxicity of DS was also abolished when its thiuram structure was destroyed. In contrast, modification of the ethyl groups in DS had no significant influence on its anticancer activity. Conclusions: The thiol groups and thiuram structure are indispensable for the anticancer activity of DS. The liver enrichment and metabolism may be the major obstruction for application of DS in cancer treatment. A delivery system to protect the thiol groups and development of novel soluble copper-DDC compound may pave the path for translation of DS into cancer therapeutics.This work was supported by grant from British Lung Foundation (RG14–8) and Innovate UK (104022).Published versio

    Inverse correlation between urethral length and continence before and after native tissue pelvic floor reconstruction

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    Urethral length was evaluated retrospectively in patients with prolapse undergoing anterior native-tissue repair. Effects of age, prolapse stage, defect pattern, urodynamic and clinical stress test findings, and tension-free vaginal tape (TVT) surgery indication were analyzed using Mann–Whitney and Wilcoxon tests and linear and logistic regression. Of 394 patients, 61% had stage II/III and 39% had stage IV prolapse; 90% of defects were central (10% were lateral). Median pre- and postoperative urethral lengths were 14 and 22 mm ( p  < 0.01). Preoperative urethral length was greater with lateral defects [ p  < 0.01, B 6.38, 95% confidence interval (CI) 4.67–8.08] and increased stress incontinence risk ( p  < 0.01, odds ratio 1.07, 95% CI 1.03–1.12). Postoperative urethral length depended on prolapse stage ( p  < 0.01, B 1.61, 95% CI 0.85–2.38) and defect type ( p  = 0.02, B – 1.42, 95% CI – 2.65 to – 0.2). Postoperatively, TVT surgery was indicated in 5.1% of patients (median 9 months), who had longer urethras than those without this indication ( p  = 0.043). Native-tissue prolapse repair including Kelly plication increased urethral length, reflecting re-urethralization, particularly with central defects. The functional impact of urethral length in the context of connective tissue aging should be examined further

    Acute postoperative pain in 23 procedures of gynaecological surgery analysed in a prospective open registry study on risk factors and consequences for the patient

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    Effective perioperative pain management is essential for optimal patient recovery after surgery and reduces the risk of chronification. However, in clinical practice, perioperative analgesic treatment still needs to be improved and data availability for evidence-based procedure specific analgesic recommendations is insufficient. We aimed to identify procedures related with high pain scores, to evaluate the effect of higher pain intensity on patients and to define patient and intervention related risk factors for increased pain after standard gynaecological and obstetrical surgery. Therefore, we performed a prospective cross-sectional study based on the German registry for quality in postoperative pain (QUIPS). A cohort of 2508 patients receiving surgery between January 2011 and February 2016 in our tertiary referral centre (university departments of gynaecology and obstetrics, respectively) answered a validated pain questionnaire on the first postoperative day. Maximal pain intensity was measured by means of a 11-point numeric rating scale (NRS) and related to procedure, perioperative care as well as patient characteristics. The interventions with the highest reported pain scores were laparoscopic removal of ovarian cysts (NRS of 6.41 ± 2.12) and caesarean section (NRS of 6.98 ± 2.08). Factors associated with higher pain intensity were younger age (OR 1.75, 95% CI 1.65–1.99), chronic pain (OR 2.08, 95% CI 1.65–2.64) and surgery performed outside the regular day shift (OR 1.67, 95% CI 1.09–2.36). Shorter duration of surgery, peridural or local analgesic and preoperative sedation reduced postoperative pain. Patients reporting high pain scores (NRS ≥ 5) showed relevant impairment of daily activities and reduced satisfaction. Caesarean section and minimal invasive procedures were associated with the highest pain scores in the present ranking. Pain management of these procedures has to be reconsidered. Younger age, receiving surgery outside of the regular shifts, chronic pain and the surgical approach itself have a relevant influence on postoperative pain intensity. When reporting pain scores of 5 or more, patients were more likely to have perioperative complications like nausea or vomiting and to be impaired in mobilisation. Registry-based data are useful to identify patients, procedures and critical situations in daily clinical routine, which increase the risk for elevated post-intervention pain. Furthermore, it provides a database for evaluation of new pain management strategies

    Ovarian cancer prevention by opportunistic salpingectomy is a new de facto standard in Germany

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    Abstract Purpose The most prevalent and aggressive subtype of epithelial ovarian carcinoma (EOC), high-grade serous carcinoma (HGSC), originates in many cases from the fallopian tubes. Because of poor prognosis and lack of effective screening for early detection, opportunistic salpingectomy (OS) for prevention of EOC is being implemented into clinical routine in several countries worldwide. Taking the opportunity of a gynecological surgery in women at average cancer risk, extramural fallopian tubes are completely resected preserving the ovaries with their infundibulopelvic blood supply. Until recently, only 13 of the 130 national partner societies of the International Federation of Obstetrics and Gynecology (FIGO) have published a statement on OS. This study aimed to analyze the acceptance of OS in Germany. Methods (1) Survey of German gynecologists in 2015 and 2022 by the Department of Gynecology of the Jena University Hospital in co-operation with the Department of Gynecology at Charité-University Medicine Berlin with support of NOGGO e. V. and AGO e. V. (2) Salpingectomy numbers in Germany for years 2005–2020 as retrieved from the Federal Statistical Office of Germany (Destatis). Results (1) Survey: Number of participants was 203 in 2015 and 166 in 2022, respectively. Nearly all respondents (2015: 92%, 2022: 98%) have already performed bilateral salpingectomy without oophorectomy in combination with benign hysterectomy with the intention to reduce the risk for malignant (2015: 96%, 2022: 97%) and benign (2015: 47%, 2022: 38%) disorders. Compared to 2015 (56.6%), considerably more survey participants performed OS in > 50% or in all cases in 2022 (89.0%). Recommendation of OS for all women with completed family planning at benign pelvic surgery was approved by 68% in 2015 and 74% in 2022. (2) Case number analysis: In 2020, four times more cases of salpingectomy were reported by German public hospitals compared to 2005 ( n  = 50,398 vs. n  = 12,286). Of all inpatient hysterectomies in German hospitals in 2020, 45% were combined with salpingectomy, and more than 65% in women at the age of 35 to 49 years. Conclusion Mounting scientific plausibility regarding involvement of fallopian tubes in the pathogenesis of EOC led to change of clinical acceptance of OS in many countries including in Germany. Case number data and widespread expert judgment demonstrate that OS has become a routine procedure in Germany and a de facto standard for primary prevention of EOC

    Release of gp120 Restraints Leads to an Entry-Competent Intermediate State of the HIV-1 Envelope Glycoproteins

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    ABSTRACT Primary human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) trimers [(gp120/gp41) 3 ] typically exist in a metastable closed conformation (state 1). Binding the CD4 receptor triggers Env to undergo extensive conformational changes to mediate virus entry. We identified specific gp120 residues that restrain Env in state 1. Alteration of these restraining residues destabilized state 1, allowing Env to populate a functional conformation (state 2) intermediate between state 1 and the full CD4-bound state (state 3). Increased state 2 occupancy was associated with lower energy barriers between the states. State 2 was an obligate intermediate for all transitions between state 1 and state 3. State 2-enriched Envs required lower CD4 concentrations to trigger virus entry and more efficiently infected cells expressing low levels of CD4. These Envs were resistant to several broadly neutralizing antibodies and small-molecule inhibitors. Thus, state 2 is an Env conformation on the virus entry pathway; sampling state 2 increases the adaptability of HIV-1 to different host cell receptor levels and immune environments. Our results provide new insights into the conformational regulation of HIV-1 entry. IMPORTANCE The envelope glycoproteins (Env) of HIV-1 mediate virus entry and are the sole targets of neutralizing antibodies. Understanding the way that Env promotes HIV-1 entry can expedite drug and vaccine development. By destabilizing Env, we found that it assumes an intermediate state that is functional and obligate for transitions to entry-competent conformations. Increased sampling of this state enhances the ability of HIV-1 to infect cells that express low levels of the CD4 receptor and allows the virus to evade neutralizing antibodies and small-molecule inhibitors. These findings provide new mechanistic insights into the function and inhibition of HIV-1 Env and will contribute to ongoing therapeutic and prevention efforts to combat HIV-1. </jats:p
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