IntroductionPostoperative myocardial revascularization atrial fibrillation (POAF) is a clinical complication that affects about 30% of patients and its mechanisms of origin are still poorly ...understood. This fact makes it difficult to identify the patient at greatest risk for this arrhythmia. This mission seems evident due to the complications it entails, including longer hospital stays, risk of stroke, heart failure, and death. There are reports of preoperative clinical aspects inherent to the patient's condition, such as gender and age, and discontinuation of beta-blockers as risk factors. In addition, additional information obtained by electrocardiogram, echocardiogram, and blood count data, for example, present only modest predictive results. The analysis of heart rate and heart rate variability obtained by the Stroke Risk Analysis System (SRA) is a technique used to predict ambulatory atrial fibrillation (AF), using recordings of only one hour showing good accuracy. This system, however, has not yet been used to predict the emergence of POAF. The rationale for its use is based on the suspicion that the emergence of POAF is strongly related to sympatho-vagal imbalance and the increase in atrial ectopia, that is, changes in heart rhythm, the main variables analyzed by the SRA algorithm.ObjectiveTo assess the accuracy of the SRA to identify patients at risk of having POAF after coronary artery bypass graft surgery (CABG).Method114 consecutive patients with coronary artery disease underwent coronary artery bypass grafting between the years 2015 and 2018. Between the first and fifth postoperative days, they underwent continuous electrocardiographic monitoring using the Holter system for cardiac rhythm analysis. Patients were divided into two groups: Group I was formed of those with POAF and Group II included patients without POAF. The tracings obtained by Holter were reanalyzed using the CardioManager®/Cardios program, converted and divided into one-hour sections using the SRA®/Cardios and Geratherm Converter program and submitted to the SRA-Apoplex medical/Geratherm® analysis algorithm. The SRA identifies three possibilities for classifying patient risk: a) Risk 0: patient in sinus rhythm; b) Risk 1: patient at increased risk for paroxysmal AF; c) Risk 2: patient with AF already present. For Group I, SRA were considered positive when Risks 1 and 2 were identified. For Group II, those identified as Risk 0 were considered negative SRA.ResultsPOAF occurred in 33/114 patients (28%). The sensitivity, specificity, positive predictive value, and negative predictive value of the SRA to identify patients with POAF were 69%, 84%, 69%, and 82%, respectively; the positive and negative likelihood ratios, in addition to the accuracy of the SRA were, respectively, 4.3%, 0.36%, and 79%. A subanalysis of the results of the day on which AF occurred was performed on the records obtained in the first three hours of recording and up to three hours before the appearance of POAF. In the first period, the SRA was able to predict POAF in 57% of cases, while in the second period, the system identified the arrhythmia in 83% of cases.Conclusionsa) The SRA presents good accuracy to predict POAF; b) its accuracy is moderate in the first three hours of recording; c) the accuracy increases significantly near the beginning of POAF; d) these findings indicate that electrophysiological changes that precede POAF are acute, occurring a few hours before the event and are identified by the SRA algorithm.
Recently, a novel antimicrobial peptide DCD-1, derived from the
Dermcidin (DCD) gene and secreted by sweat glands, has been described by Schittek et al.
Nat. Immunol. 2 (2001) 1133.. Here we ...describe the application of the surface-enhanced laser desorption/ionisation (SELDI) technology for the detection of DCD-1 and other dermcidin-derived peptides directly from microlitre amounts of human sweat. The advantages of the technique are as follows: (a) it can be carried out with ease and rapidity; (b) multiple samples can be processed simultaneously; (c) prior purification is not required; and (d) only a limited sample volume is necessary for both protein profiling and semiquantitation. Profiling of human sweat from various donors revealed that in addition to DCD-1, other DCD-derived peptide species were also present in significant quantities. Four of five identified peptides were DCD-1 related, while the fifth corresponded to a portion of the DCD protein outside the DCD-1 core. This provides clues as to how the novel protein is processed to its active form, though further work remains to elucidate this fully. Thus, we have demonstrated the applicability of such technology to the detection of DCD-1 and for the protein profiling of sweat in general. Such studies could reveal valuable new biomarkers for diagnosis and treatment of skin and sweat gland disorders.
To evaluate the efficacy and safety of vindesine in patients with metastatic melanoma after complete metastasectomy. One hundred and forty-two patients with metastatic spread to regional sites, lymph ...nodes, and distant sites after complete metastasectomy were randomized to receive either treatment with vindesine for 2 years or observation alone. Vindesine 3 mg/m intravenously was administered biweekly for the first 26 weeks following 3-week intervals for an additional 26 weeks and thereafter every 4 weeks for 52 weeks. One hundred and thirty-nine patients were eligible for intent-to-treat analysis. Median follow-up time was 46 months. Median recurrence free survival was 7.9 months in the vindesine group and 7.6 months in the observational group (P=0.40). Three-year overall survival rate was 54.9% (37 patients) for patients receiving vindesine in comparison to 43.6% (31 patients) in the observation arm (P=0.07). No grade IV toxicity was observed. The two major side effects in the vindesine group were alopecia and peripheral neuropathy. Ten patients went off treatment because of grade III toxicity. Adjuvant treatment with vindesine did not significantly prolong disease free or overall survival in high-risk melanoma patients. Thus, this randomized trial did not confirm earlier reports of beneficial effects of adjuvant vindesine and can therefore not be recommended.
A silver containing coating used in the human body, e.g., on an implant should be both effectively antimicrobial and non-cytotoxic to human cells. It is generally believed that the biologic effect ...originates from silver ions released from the coating. Nanocomposites with well controlled Ag filling factor were prepared by co-sputtering, and the silver surface concentration and the silver release were determined by XPS and ICP-MS, respectively. Here we show that only a small therapeutic window exists for dissolved silver but the therapeutic window is largely increased at the surface. While the toxicity observed for mammalian cells in contact with the bioactive Ag/TiO2 nanocomposite surface and for silver ions in solution is rather similar the antimicrobial activity is drastically enhanced at the surface. A model is proposed to explain the strong increase of the antimicrobial activity at the surface. The present results not only question well-established tests for antimicrobial activity but they are also important for the design of antimicrobial coatings, e.g., for biomedical devices.
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► Controlled preparation of Ag/TiO2 nanocomposite coating by co-sputtering method ► Comparable in vitro model for dissolved silver and silver nanocomposite coatings ► Comparable in vitro model for bacterial and mammalian cell effects of silver ► Therapeutic window for silver strongly enhanced at the surface
Ex vivo culture and expansion of autologous haemopoietic transplants has been developed to improve tumour cell purging and accelerate haemopoietic reconstitution by transplantation of increased ...progenitor cell numbers. We studied the effect of the negative haemopoietic regulator, transforming growth factor beta‐1 (TGF‐beta 1) on primitive precursors during ex vivo expansion of CD34+ cells. When added directly to methylcellulose colony‐forming assays, TGF‐beta 1 potently suppressed the development of granulocyte‐macrophage colonies from CD34+ enriched peripheral blood progenitor cells (80–90% inhibition). In contrast, expansion of total nucleated cells and granulocyte‐macrophage colony‐forming cells (GM‐CFC) from CD34+ progenitors in liquid culture in the presence of stem cell factor (SCF), interleukin (IL)‐1 beta, IL‐3, IL‐6 and erythropoietin (EPO) was inhibited to 32–65% of control culture levels within 14 d when TGF‐beta 1 was added, and still produced an average 3.3‐fold absolute amplification of GM‐CFC. The inhibitory effect of TGF‐beta 1 on GM‐CFC generation was reversed when it was washed out on day 6 of ex vivo expansion cultures, and total numbers of GM‐CFC generated from expansion cultures then reached levels of untreated controls by day 16. Long‐term bone marrow culture‐initiating cell (LTCIC) numbers were preserved, at least at input levels, over a culture period of 14 d both in control and TGF‐beta‐1‐treated expansion cultures. These findings suggest that TGF‐beta 1, a cytokine which induces apoptosis or terminal differentiation in a number of malignant cell types, may be added to ex vivo expansion cultures without loss of primitive cells from autologous haemopoietic transplants.
Linear inverse problems in computer vision, including motion estimation, shape fitting and image reconstruction, give rise to parameter estimation problems with highly correlated errors in variables. ...Established total least squares methods estimate the most likely corrections Acirc and bcirc to a given data matrix A, b perturbed by additive Gaussian noise, such that there exists a solution y with A + Acirc, b +bcircy = 0. In practice, regression imposes a more restrictive constraint namely the existence of a solution x with A + Acircx = b + bcirc. In addition, more complicated correlations arise canonically from the use of linear filters. We, therefore, propose a maximum likelihood estimator for regression in the general case of arbitrary positive definite covariance matrices. We show that Acirc, bcirc and x can be found simultaneously by the unconstrained minimization of a multivariate polynomial which can, in principle, be carried out by means of a Grobner basis. Results for plane fitting and optical flow computation indicate the superiority of the proposed method.
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