Successful and safe use of 2 min cold atmospheric argon plasma in chronic wounds: results of a randomized controlled trial.

BACKGROUND: The development of antibiotic resistance by microorganisms is an increasing problem in medicine. In chronic wounds, bacterial colonization is associated with impaired healing. Cold atmospheric plasma is an innovative promising tool to deal with these problems. OBJECTIVES: The 5-min argon plasma treatment has already demonstrated efficacy in reducing bacterial numbers in chronic infected wounds in vivo. In this study we investigated a 2-min plasma treatment with the same device and the next-generation device, to assess safety and reduction in bacterial load, regardless of the kind of bacteria and their resistance level in chronic wounds. METHODS: Twenty-four patients with chronic infected wounds were treated in a prospective randomized controlled phase II study with 2 min of cold atmospheric argon plasma every day: 14 with MicroPlaSter alpha device, 10 with MicroPlaSter beta device (next-generation device) in addition to standard wound care. The patient acted as his/her own control. Bacterial species were detected by standard bacterial swabs and bacterial load by semiquantitative count on nitrocellulose filters. The plasma settings were the same as in the previous phase II study in which wounds were exposed for 5 min to argon plasma. RESULTS: Analysis of 70 treatments in 14 patients with the MicroPlaSter alpha device revealed a significant (40%, P<0.016) reduction in bacterial load in plasma-treated wounds, regardless of the species of bacteria. Analysis of 137 treatments in 10 patients with the MicroPlaSter beta device showed a highly significant reduction (23.5%, P<0.008) in bacterial load. No side-effects occurred and the treatment was well tolerated. CONCLUSIONS: A 2-min treatment with either of two cold atmospheric argon plasma devices is a safe, painless and effective technique to decrease the bacterial load in chronic wounds.

A first prospective randomized controlled trial to decrease bacterial load using cold atmospheric argon plasma on chronic wounds in patients.

BACKGROUND: Bacterial colonization of chronic wounds slows healing. Cold atmospheric plasma has been shown in vitro to kill a wide range of pathogenic bacteria. Objectives To examine the safety and efficiency of cold atmospheric argon plasma to decrease bacterial load as a new medical treatment for chronic wounds. PATIENTS AND METHODS: Thirty-eight chronic infected wounds in 36 patients were treated in a prospective randomized controlled phase II study with 5 min daily cold atmospheric argon plasma in addition to standard wound care. The patient acted as his or her own control. Bacterial species were detected by standard bacterial swabs and semiquantitative changes by nitrocellulose filters. Plasma setting and safety had been determined in a preceding phase I study. RESULTS: Analysis of 291 treatments in 38 wounds found a highly significant (34%, P < 10(-6)) reduction of bacterial load in treated wounds, regardless of the type of bacteria. No side-effects occurred and the treatment was well tolerated. CONCLUSIONS: Cold atmospheric argon plasma treatment is potentially a safe and painless new technique to decrease bacterial load of chronic wounds and promote healing.

Chaos in dynamic atomic force microscopy.

In tapping mode atomic force microscopy (AFM) the highly nonlinear tip-sample interaction gives rise to a complicated dynamics of the microcantilever. Apart from the well-known bistability under typical imaging conditions the system exhibits a complex dynamics at small average tip-sample distances, which are typical operation conditions for mechanical dynamic nanomanipulation. In order to investigate the dynamics at small average tip sample gaps experimental time series data are analysed employing nonlinear analysis tools and spectral analysis. The correlation dimension is computed together with a bifurcation diagram. By using statistical correlation measures such as the Kullback-Leibler distance, cross-correlation and mutual information the dataset can be segmented into different regimes. The analysis reveals period-3, period-2 and period-4 behaviour, as well as a weakly chaotic regime.

Scaling-index method as an image processing tool in scanning-probe microscopy.

The scaling-index method (SIM) is a novel tool for image processing in scanning-probe microscopy. Originating from the theory of complex systems, the SIM can be used in order to extract structural information from arbitrary data sets. This method can readily be applied to the analysis of digital atomic-force microscopy (AFM) images. Especially for biomedical diagnostics, where genetic material is investigated by various microscopic methods, a reliable image segmentation based on the SIM algorithm is helpful. As a first application, AFM-images of GTG-banded human metaphase chromosomes (with G bands obtained by Trypsin using Giemsa) are compared with micrographs from conventional light microscopy by means of a scaling-index analysis. While the grey-level distributions of the optical and the AFM-images are largely different from each other, the scaling-index images are remarkably similar. Using this method, a fingerprint of an image can be produced which helps in the classification and interpretation of the measured data.

Improving early recognition of malignant melanomas by digital image analysis in dermatoscopy.

The malignant melanoma (MM) is the most dangerous human skin disease. The incidence increased dramatically during the last years. The only chance for the patient is an early recognition and excision of the MM. The best diagnostic method for this is skin surface microscopy or dermatoscopy. Its use, however, requires much expertise. In order to support learning and using the method, a computer-based dermatoscopy workstation is being developed. Among others, new complexity measures are used for the image analysis.

[Complexity analysis and intrapartum CTG]. / Komplexitätsanalyse und intrapartuales CTG.

OBJECTIVES: This study was performed to prove, if the use of methods, that are based on procedures for analysis of chaotic systems ("complexity analysis"), can give information on the fetal condition during birth and predict both the course of delivery and fetal outcome. PATIENTS AND METHODS: Fetal ECG was derived in 37 pregnancies (36-42 weeks of gestation) during birth for two to seven hours. In 12 cases delivery was uncomplicated, in 24 cases FHR tracings had been pathological. RESULTS: Complexity analysis of fetal ECG signals showed within short observation intervals criteria that may be a hint for imminent fetal distress and acidosis. CONCLUSIONS: Application of complexity analysis in the future may give additional information for evaluation of intrapartum CTG in cases of suspicious FHR patterns.