Rapid intra‐operative diagnosis of kidney cancer by attenuated total reflection infrared spectroscopy of tissue smears

Herein, a technique to analyze air‐dried kidney tissue impression smears by means of attenuated total reflection infrared (ATR‐IR) spectroscopy is presented. Spectral tumor markers—absorption bands of glycogen—are identified in the ATR‐IR spectra of the kidney tissue smear samples. Thin kidney tissue cryo‐sections currently used for IR spectroscopic analysis lack such spectral markers as the sample preparation causes irreversible molecular changes in the tissue. In particular, freeze‐thaw cycle results in degradation of the glycogen and reduction or complete dissolution of its content. Supervised spectral classification was applied to the recorded spectra of the smears and the test spectra were classified with a high accuracy of 92% for normal tissue and 94% for tumor tissue, respectively. For further development, we propose that combination of the method with optical fiber ATR probes could potentially be used for rapid real‐time intra‐operative tissue analysis without interfering with either the established protocols of pathological examination or the ordinary workflow of operating surgeon. Such approach could ensure easier transition of the method to clinical applications where it may complement the results of gold standard histopathology examination and aid in more precise resection of kidney tumors.      

Evaluation of a new semi-automated Hydragel 11 von Willebrand factor multimers assay kit for routine use

BackgroundAccurate diagnosis and classification of von Willebrand disease (VWD) are essential for optimal management. The von Willebrand factor multimers analysis (VWF:MM) is an integral part of the diagnostic process in the phenotypic classification, especially in discrepant cases. The aim of this study was to evaluate the performance of a new Hydragel 11VWF multimer assay (H11VW).MethodsAnalytical performance characteristics such as repeatability (intra-assay variability, in gel between track variation), reproducibility (inter-assay variability, between gel variation), sensitivity, EQA performance and differences between two commercially available VWF:MM kits (H5VW and H11VW) were analysed in healthy volunteers'' plasmas using in-house prepared reference plasma.ResultsRepeatability and reproducibility results of H11VW demonstrated acceptable and equivalent performance with previously verified H5VW. Participation in EQA was successful. No statistically significant difference was detected between H5VW and H11VW kits for different fractions of multimers: LMWM p=0.807; IMWM p=0.183; HMWM p=0.774.ConclusionsH11VW demonstrated acceptable analytical performance characteristics. H11VW kit conveniently offers a more significant number of samples on a single gel. H5VW and H11VW kits can be used in daily practice interchangeably.     

Fiber attenuated total reflection infrared spectroscopy of kidney tissue during live surgery

More than 90% of solid kidney tumors are cancerous and have to be treated by surgical resection where surgical outcomes and patient prognosis are dependent on the tumor discrimination. The development of alternative approaches based on a new generation of fiber attenuated total reflection (ATR) probes could aid tumor identification even under intrasurgical conditions. Herein, fiber ATR IR spectroscopy is employed to distinguish normal and cancerous kidney tissues. Freshly resected tissue samples from 34 patients are investigated under nearly native conditions. Spectral marker bands that allow a reliable discrimination between tumor and normal tissue are identified by a supervised classification algorithm. The absorbance values of the bands at 1025, 1155 and 1240 cm^?1 assigned to glycogen and fructose 1,6‐bisphosphatase are used as the clearest markers for the tissue discrimination. Absorbance threshold values for tumor and normal tissue are determined by discriminant analysis. This new approach allows the surgeon to make a clinical diagnosis.