An automated cell viability quantification method for low-resolution confocal images of closely packed cells based on a modified gradient flow tracking algorithm.

Fluorescent-based live/dead labelling combined with fluorescent microscopy is one of the widely used and reliable methods for assessment of cell viability. This method is, however, not quantitative. Many image-processing methods have been proposed for cell quantification in an image. Among all these methods, several of them are capable of quantifying the number of cells in high-resolution images with closely packed cells. However, no method has addressed the quantification of the number of cells in low-resolution images containing closely packed cells with variable sizes. This paper presents a novel method for automatic quantification of live/dead cells in 2D fluorescent low-resolution images containing closely packed cells with variable sizes using a mean shift-based gradient flow tracking. Accuracy and performance of the method was tested on growth plate confocal images. Experimental results show that our algorithm has a better performance in comparison to other methods used in similar detection conditions.

[Perioperative patient management. Evaluation of subjective stress and demands of patients undergoing elective gynaecological surgery]. / Perioperatives Patientenmanagement. Evaluation von subjektiver Beanspruchung bei Patientinnen mit elektiven gynäkologischen Operationen.

BACKGROUND: The aim of this investigation was to assess the extent of stress and demands in patients during preparation for general anesthesia for elective surgical procedures. PATIENTS AND METHODS: A total of 52 female patients scheduled for elective gynecological surgery under general anesthesia were included in this prospective study. The extent and time course of actual demands describing perceived emotional stress was assessed at close intervals using the German version of the Questionnaire for Actual Demands (KAB). Pre-operative and postoperative anxiety was assessed using part one of Spielberger's state-trait-anxiety inventory (STAI-X1). This was compared to hemodynamic (heart rate und blood pressure) and endocrinal stress parameters [cortisol concentration in serum and saliva, prolactin and dehydroepiandrosteronesulfate (DHEA-S) in serum]. Postoperatively, all patients were asked to rate the quality of care during preparation for general anesthesia. RESULTS: The extent of patients' demands and stress during preparation for general anesthesia could be quantified by the short questionnaire for the actual demands (KAB). So-called objective stress parameters like hemodynamic and endocrinal data alone did not correlate with perceived stress. However, the subjective information correlated with the nature of the underlying diagnosis. The postoperative assessment of quality of care during preparation for general anesthesia did not correlate with the course of actual demands and stress. CONCLUSION: In future studies assessing the perioperative management of patients and quality of care, standardized testing questionnaires should be preferred, instead of vegetative parameters alone, to reliably evaluate perioperative demands and stress in surgical patients.