799 research outputs found
DNA binding shifts the redox potential of the transcription factor SoxR
Electrochemistry measurements on DNA-modified electrodes are used to probe the effects of binding to DNA on the redox potential of SoxR, a transcription factor that contains a [2Fe-2S] cluster and is activated through oxidation. A DNA-bound potential of +200 mV versus NHE (normal hydrogen electrode) is found for SoxR isolated from Escherichia coli and Pseudomonas aeruginosa. This potential value corresponds to a dramatic shift of +490 mV versus values found in the absence of DNA. Using Redmond red as a covalently bound redox reporter affixed above the SoxR binding site, we also see, associated with SoxR binding, an attenuation in the Redmond red signal compared with that for Redmond red attached below the SoxR binding site. This observation is consistent with a SoxR-binding-induced structural distortion in the DNA base stack that inhibits DNA-mediated charge transport to the Redmond red probe. The dramatic shift in potential for DNA-bound SoxR compared with the free form is thus reconciled based on a high-energy conformational change in the SoxR–DNA complex. The substantial positive shift in potential for DNA-bound SoxR furthermore indicates that, in the reducing intracellular environment, DNA-bound SoxR is primarily in the reduced form; the activation of DNA-bound SoxR would then be limited to strong oxidants, making SoxR an effective sensor for oxidative stress. These results more generally underscore the importance of using DNA electrochemistry to determine DNA-bound potentials for redox-sensitive transcription factors because such binding can dramatically affect this key protein property
Clinical-pathological study on β-APP, IL-1β, GFAP, NFL, Spectrin II, 8OHdG, TUNEL, miR-21, miR-16, miR-92 expressions to verify DAI-diagnosis, grade and prognosis
Traumatic brain injury (TBI) is one of the most important death and disability cause, involving substantial costs, also in economic terms, when considering the young age of the involved subject. Aim of this paper is to report a series of patients treated at our institutions, to verify neurological results at six months or survival; in fatal cases we searched for βAPP, GFAP, IL-1β, NFL, Spectrin II, TUNEL and miR-21, miR-16, and miR-92 expressions in brain samples, to verify DAI diagnosis and grade as strong predictor of survival and inflammatory response. Concentrations of 8OHdG as measurement of oxidative stress was performed. Immunoreaction of β-APP, IL-1β, GFAP, NFL, Spectrin II and 8OHdG were significantly increased in the TBI group with respect to control group subjects. Cell apoptosis, measured by TUNEL assay, were significantly higher in the study group than control cases. Results indicated that miR-21, miR-92 and miR-16 have a high predictive power in discriminating trauma brain cases from controls and could represent promising biomarkers as strong predictor of survival, and for the diagnosis of postmortem traumatic brain injury
Systemic Lupus Erythematosus and Lupus Nephritis Presenting as Severe Constitutional Symptoms
Systemic lupus erythematosus (SLE) is a remitting-relapsing systemic autoantibody and immune complex disease with a similar clinical presentation to that of malignancy and infection. The authors report a case of newly diagnosed SLE and lupus nephritis in a 48-year-old woman with constitutional symptoms and unintentional weight loss. Her presentation was further complicated by pericardial effusion and methicillin-resistant Staphylococcus aureus (MRSA) facial cellulitis and bacteremia. In the context of nonspecific symptoms and a wide initial differential diagnosis, the early consideration of rheumatologic etiologies and the involvement of consultant services led to appropriate diagnostic testing and a timely diagnosis
The effect of cataract on early stage glaucoma detection using spatial and temporal contrast sensitivity tests
Background:
To investigate the effect of cataract on the ability of spatial and temporal contrast sensitivity tests used to detect early glaucoma.
Methods:
Twenty-seven glaucoma subjects with early cataract (mean age 60 ±10.2 years) which constituted the test group were recruited together with twenty-seven controls (cataract only) matched for age and cataract type from a primary eye care setting. Contrast sensitivity to flickering gratings at 20 Hz and stationary gratings with and without glare, were measured for 0.5, 1.5 and 3 cycles per degree (cpd) in central vision. Perimetry and structural measurements with the Heidelberg Retinal Tomograph (HRT) were also performed.
Results:
After considering the effect of cataract, contrast sensitivity to stationary gratings was reduced in the test group compared with controls with a statistically significant mean difference of 0.2 log units independent of spatial frequency. The flicker test showed a significant difference between test and control group at 1.5 and 3 cpd (p = 0.019 and p = 0.011 respectively). The percentage of glaucoma patients who could not see the temporal modulation was much higher compared with their cataract only counterparts. A significant correlation was found between the reduction of contrast sensitivity caused by glare and the Glaucoma Probability Score (GPS) as measured with the HRT (p<0.005).
Conclusions:
These findings indicate that both spatial and temporal contrast sensitivity tests are suitable for distinguishing between vision loss as a consequence of glaucoma and vision loss caused by cataract only. The correlation between glare factor and GPS suggests that there may be an increase in intraocular stray light in glaucoma
Development of sentinel node localization and ROLL in breast cancer in Europe
The concept of a precise region in which to find the lymph nodes that drain the lymph directly from the primary tumor site can be traced back to a century ago to the observations of Jamieson and Dobson who described how cancer cells spread from cancer of the stomach in a single lymph node, which they called the â\u80\u9cprimary glandâ\u80\u9d. However, Cabanas was the first in 1977 to realize the importance of this concept in clinical studies following lymphography performed in patients with penile cancer. Thanks to Mortonâ\u80\u99s studies on melanoma in 1992, we began to understand the potential impact of the sentinel lymph node (SN) on the surgical treatment of this type of cancer. The use of a vital dye (blue dye) administered subdermally in the region surrounding the melanoma lesion led to the identification of the sentinel node, and the vital dye technique was subsequently applied to other types of solid tumors, e.g. breast, vulva. However, difficulties in using this technique in anatomical regions with deep lymphatic vessels, e.g. axilla, led to the development of lymphoscintigraphy, started by Alex and Krag in 1993 on melanoma and breast cancer and optimized by our group at European Institute of Oncology (IEO) in Milan in 1996. Today, lymphoscintigraphy is still considered as the most reliable method for the detection of the SN. In 1996, a new method for the localization of non-palpable breast lesion called radioguided occult lesion localization (ROLL) was also developed at IEO. Retrospective and prospective studies have since shown that the ROLL procedure permits the easy and accurate surgical removal of non-palpable breast lesions, overcoming the limitations of previous techniques such as the wire-guided localization. The purpose of this paper is to describe the evolution of SN biopsy and radioguided surgery in the management of breast cancer. We also include a review of the literature on the clinical scenarios in which SN biopsy in breast cancer is currently used, with particular reference to controversies and future prospects
The global burden of tuberculosis: results from the Global Burden of Disease Study 2015
Background:
An understanding of the trends in tuberculosis incidence, prevalence, and mortality is crucial to tracking
of the success of tuberculosis control programmes and identification of remaining challenges. We assessed trends in the fatal and non-fatal burden of tuberculosis over the past 25 years for 195 countries and territories.
Methods:
We analysed 10 691 site-years of vital registration data, 768 site-years of verbal autopsy data, and 361 site-years of mortality surveillance data using the Cause of Death Ensemble model to estimate tuberculosis mortality rates. We analysed all available age-specific and sex-specific data sources, including annual case notifications, prevalence surveys, and estimated cause-specific mortality, to generate internally consistent estimates of incidence, prevalence, and mortality using DisMod-MR 2.1, a Bayesian meta-regression tool. We assessed how observed tuberculosis incidence, prevalence, and mortality differed from expected trends as predicted by the Socio-demographic Index (SDI), a composite indicator based on income per capita, average years of schooling, and total fertility rate. We also estimated tuberculosis mortality and disability-adjusted life-years attributable to the independent effects of risk factors including smoking, alcohol use, and diabetes.
Findings:
Globally, in 2015, the number of tuberculosis incident cases (including new and relapse cases) was
10·2 million (95% uncertainty interval 9·2 million to 11·5 million), the number of prevalent cases was 10·1 million
(9·2 million to 11·1 million), and the number of deaths was 1·3 million (1·1 million to 1·6 million). Among individuals
who were HIV negative, the number of incident cases was 8·8 million (8·0 million to 9·9 million), the number of
prevalent cases was 8·9 million (8·1 million to 9·7 million), and the number of deaths was 1·1 million (0·9 million to 1·4 million). Annualised rates of change from 2005 to 2015 showed a faster decline in mortality (–4·1%
[–5·0 to –3·4]) than in incidence (–1·6% [–1·9 to –1·2]) and prevalence (–0·7% [–1·0 to –0·5]) among HIV-negative
individuals. The SDI was inversely associated with HIV-negative mortality rates but did not show a clear gradient for incidence and prevalence. Most of Asia, eastern Europe, and sub-Saharan Africa had higher rates of HIV-negative tuberculosis burden than expected given their SDI. Alcohol use accounted for 11·4% (9·3–13·0) of global tuberculosis deaths among HIV-negative individuals in 2015, diabetes accounted for 10·6% (6·8–14·8), and smoking accounted for 7·8% (3·8–12·0).
Interpretation:
Despite a concerted global effort to reduce the burden of tuberculosis, it still causes a large disease
burden globally. Strengthening of health systems for early detection of tuberculosis and improvement of the quality
of tuberculosis care, including prompt and accurate diagnosis, early initiation of treatment, and regular follow-up, are priorities. Countries with higher than expected tuberculosis rates for their level of sociodemographic development should investigate the reasons for lagging behind and take remedial action. Efforts to prevent smoking, alcohol use, and diabetes could also substantially reduce the burden of tuberculosis
Comparative Analysis of Interactive Modalities for Intuitive Endovascular Interventions
: Endovascular intervention is a minimally invasive method for treating cardiovascular diseases. Although fluoroscopy, known for real-time catheter visualization, is commonly used, it exposes patients and physicians to ionizing radiation and lacks depth perception due to its 2D nature. To address these limitations, a study was conducted using teleoperation and 3D visualization techniques. This in-vitro study involved the use of a robotic catheter system and aimed to evaluate user performance through both subjective and objective measures. The focus was on determining the most effective modes of interaction. Three interactive modes for guiding robotic catheters were compared in the study: 1) Mode GM, using a gamepad for control and a standard 2D monitor for visual feedback; 2) Mode GH, with a gamepad for control and HoloLens providing 3D visualization; and 3) Mode HH, where HoloLens serves as both control input and visualization device. Mode GH outperformed other modalities in subjective metrics, except for mental demand. It exhibited a median tracking error of 4.72 mm, a median targeting error of 1.01 mm, a median duration of 82.34 s, and a median natural logarithm of dimensionless squared jerk of 40.38 in the in-vitro study. Mode GH showed 8.5%, 4.7%, 6.5%, and 3.9% improvements over Mode GM and 1.5%, 33.6%, 34.9%, and 8.1% over Mode HH for tracking error, targeting error, duration, and dimensionless squared jerk, respectively. To sum up, the user study emphasizes the potential benefits of employing HoloLens for enhanced 3D visualization in catheterization. The user study also illustrates the advantages of using a gamepad for catheter teleoperation, including user-friendliness and passive haptic feedback, compared to HoloLens. To further gauge the potential of using a more traditional joystick as a control input device, an additional study utilizing the Haption VirtuoseTM robot was conducted. It reveals the potential for achieving smoother trajectories, with a 38.9% reduction in total path length compared to a gamepad, potentially due to its larger range of motion and single-handed control
Machine Learning based Energy Management Model for Smart Grid and Renewable Energy Districts
The combination of renewable energy sources and prosumer-based smart grid is a sustainable solution to cater to the problem of energy demand management. A pressing need is to develop an efficient Energy Management Model (EMM) that integrates renewable energy sources with smart grids. However, the variable scenarios and constraints make this a complex problem. Machine Learning (ML) methods can often model complex and non-linear data better than the statistical models. Therefore, developing an ML algorithm for the EMM is a suitable option as it reduces the complexity of the EMM by developing a single trained model to predict the performance parameters of EMM for multiple scenarios. However, understanding latent correlations and developing trust in highly complex ML models for designing EMM within the stochastic prosumer-based smart grid is still a challenging task. Therefore, this paper integrates ML and Gaussian Process Regression (GPR) in the EMM. At the first stage, an optimization model for Prosumer Energy Surplus (PES), Prosumer Energy Cost (PEC), and Grid Revenue (GR) is formulated to calculate base performance parameters (PES, PEC, and GR) for the training of the ML-based GPR model. In the second stage, stochasticity of renewable energy sources, load, and energy price, same as provided by the Genetic Algorithm (GA) based optimization model for PES, PEC, and GR, and base performance parameters act as input covariates to produce a GPR model that predicts PES, PEC, and GR. Seasonal variations of PES, PEC, and GR are incorporated to remove hitches from seasonal dynamics of prosumers energy generation and prosumers energy consumption. The proposed adaptive Service Level Agreement (SLA) between energy prosumers and the grid benefits both these entities. The results of the proposed model are rigorously compared with conventional optimization (GA and PSO) based EMM to prove the validity of the proposed model
BRYOSTATIN-1 LIMITS NEUTROPHIL TRANSENDOTHELIAL MIGRATION FOLLOWING ISCHEMIA-REPERFUSION INJURY: IMPACT FOR THERAPY
Poster presentation to the 25th Annual Meeting of the German Transplantation Society, Essen, Germany, 5–8 October 2016.Introduction and Background: Ischemia-reperfusion injury (IRI) is an inherent component of solid organ transplantation and axiomatically linked to graft damage. In the kidney, vascular endothelial cells (EC) are highly vulnerable to IRI. These cells are the first site of graft injury, while neutrophils are the first line of host defense after reperfusion. The degree of renal EC damage predicts the severity of neutrophil transendothelial migration (TEM), with neutrophils in turn orchestrating the influx of subsequent leukocytes waves into the graft. Therefore, EC integrity and neutrophil TEM represent promising targets to attenuate IRI. One drug known to stabilize EC integrity and to limit neutrophil TEM is Bryostatin-1, an activator of the EC second messenger protein kinase C delta. Therefore, we examined the role of Bryostatin-1 on neutrophil TEM in an in vitro IRI model.
Methods: We used an in vitro IRI model with human umbilical vein ECs (HUVECs) and human neutrophils (approved by the ethic committee (STUDY00000261) to study the role of Bryostatin-1 in IRI-induced neutrophil TEM. HUVECs were exposed to either normoxic (21% O2) or hypoxic (1.5% O2) conditions for 20 hours (h) with and without Bryostatin-1 (1-100 nM) followed by 2 h exposure to Calcein-AM dye labeled neutrophils. TEM to saline or the chemoattractant leukotriene B4 (LTB4) was determined by measuring fluorescence intensity and myeloperoxidase (MPO) production.
Results and Conclusions: Bryostatin-1 dose-dependently inhibited human neutrophil TEM under normoxic and hypoxic conditions. Bryostatin-1 (100 nM) blocked 75% (P < 0.05) of TEM toward LTB4 in normoxic conditions; this was intensified when HUVECs were placed in hypoxic conditions (83%, P < 0.001). These data were further supported by a mirrored effect when MPO production (a marker of neutrophil activation) was measured. In summary, these promising in vitro results demonstrate that our model recapitulates IRI-induced EC damage, and most importantly that Bryostatin-1 alters neutrophil TEM in an in vitro IRI model
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