Lessons learned during implementation of MR-guided High-Intensity Focused Ultrasound treatment of uterine fibroids.

BACKGROUND: Although promising results have been reported for Magnetic Resonance image-guided High-Intensity Focused Ultrasound (MR-HIFU) treatment of uterine fibroids, this treatment is not yet widely implemented in clinical practice. During the implementation of a new technology, lessons are learned and an institutional learning-curve often has to be completed. The primary aim of our prospective cohort study was to characterize our learning-curve based on our clinical outcomes. Secondary aims included identifying our lessons learned during implementation of MR-HIFU on a technical, patient selection, patient counseling, medical specialists and organizational level. RESULTS: Our first seventy patients showed significant symptom reduction and improvement of quality of life at 3, 6 and 12 months after MR-HIFU treatment compared to baseline. After the first 25 cases, a clear plateau phase was reached in terms of failed treatments. The median non-perfused volume percentage of these first 25 treatments was 44.6% (range: 0-99.7), compared to a median of 74.7% (range: 0-120.6) for the subsequent treatments. CONCLUSIONS: Our findings describe the learning-curve during the implementation of MR-HIFU and include straightforward suggestions to shorten learning-curves for future users. Moreover, the lessons we learned on technique, patient selection, patient counseling, medical specialists and organization, together with the provided supplements, may be of benefit to other institutions aiming to implement MR-HIFU treatment of uterine fibroids. Trial registration ISRCTN14634593. Registered January 12, 2021-Retrospectively registered, https://www.isrctn.com/ISRCTN14634593 .

Critical appraisal of quantitative PCR results in colorectal cancer research: can we rely on published qPCR results?

The use of real-time quantitative polymerase chain reaction (qPCR) in cancer research has become ubiquitous. The relative simplicity of qPCR experiments, which deliver fast and cost-effective results, means that each year an increasing number of papers utilizing this technique are being published. But how reliable are the published results? Since the validity of gene expression data is greatly dependent on appropriate normalisation to compensate for sample-to-sample and run-to-run variation, we have evaluated the adequacy of normalisation procedures in qPCR-based experiments. Consequently, we assessed all colorectal cancer publications that made use of qPCR from 2006 until August 2013 for the number of reference genes used and whether they had been validated. Using even these minimal evaluation criteria, the validity of only three percent (6/179) of the publications can be adequately assessed. We describe common errors, and conclude that the current state of reporting on qPCR in colorectal cancer research is disquieting. Extrapolated to the study of cancer in general, it is clear that the majority of studies using qPCR cannot be reliably assessed and that at best, the results of these studies may or may not be valid and at worst, pervasive incorrect normalisation is resulting in the wholesale publication of incorrect conclusions. This survey demonstrates that the existence of guidelines, such as MIQE, is necessary but not sufficient to address this problem and suggests that the scientific community should examine its responsibility and be aware of the implications of these findings for current and future research.

KRAS mutation analysis on low percentage of colon cancer cells: the importance of quality assurance.

KRAS mutation testing is mandatory for patients with metastatic colorectal cancer who are eligible for treatment with an epidermal growth factor receptor targeting agent, since tumors with a mutation are not sensitive to the drug. Several methods for mutation testing are in use and the need for external quality assurance has been demonstrated. An often little addressed but important issue in external quality assurance schemes is a low percentage of tumor cells in the test samples, where the analytical sensitivity of most tests becomes critical. Using artificial samples based on a mixture of cell lines with known mutation status of the KRAS gene, we assessed the reliability of a series of commonly used methods (Sanger sequencing, high resolution melting, pyrosequencing, and amplification refractory mutation system-polymerase chain reaction) on samples with 0, 2.5, 5, 10, and 15 % mutated cells. Nine laboratories throughout Europe participated and submitted a total of ten data sets. The limit of detection of each method differed, ranging from >15-5 % tumor cells. All methods showed a decreasing correct mutation call rate proportionally with decreasing percentage of tumor cells. Our findings indicate that laboratories and clinicians need to be aware of the decrease in correct mutation call rate proportionally with decreasing percentage of tumor cells and that external quality assurance schemes need to address the issue of low tumor cell percentage in the test samples.

MicroRNA expression in formalin-fixed paraffin embedded tissue using real time quantitative PCR: the strengths and pitfalls.

MicroRNAs (miRNAs) are a group of small non-coding RNAs with a huge impact in a wide range of biological processes, including cancer. The evidence collected to date demonstrates that miRNAs represent valid diagnostic, prognostic and predictive markers in cancer. The identification of these miRNA biomarkers in archived tissues has been facilitated by novel development and refinement of detection methodologies. Quantitative real-time reverse-transcription PCR (qRT-PCR) is one of the most common methods used to detect low levels of miRNAs with high sensitivity and specificity. However, several technical parameters should be identified and optimized in order to obtain meaningful and reproducible results. The purpose of this review is to describe some of these technical parameters and improve the validity and reliability of miRNA expression studies.

Simultaneous presence of multiple Campylobacter species in dogs.

The prevalence of coinfection of Campylobacter species in dogs was determined using four isolation methods. In 26% of the positive-testing stools, multiple Campylobacter species were identified. The use of multiple isolation methods as well as the time lapse between sampling and processing are important for detection of coinfection.

Methods to evaluate functional nerve recovery in adult rats: walking track analysis, video analysis and the withdrawal reflex.

The aim of this study was to compare different methods for the evaluation of functional nerve recovery. Three groups of adult male Wistar rats were studied. In group A, a 12-mm gap between nerve ends was bridged by an autologous nerve graft; in rats of group B we performed a crush lesion of the sciatic nerve and group C consisted of non-operated control rats. The withdrawal reflex, elicited by an electric stimulus, was used to evaluate the recovery of sensory nerve function. To investigate motor nerve recovery we analyzed the walking pattern. Three different methods were used to obtain data for footprint analysis: photographic paper with thickened film developer on the paws, normal white paper with finger paint, and video recordings. The footprints were used to calculate the sciatic function index (SFI). From the video recordings, we also analyzed stepcycles. The withdrawal reflex is a convenient and reproducible test for the evaluation of global sensory nerve recovery. Recording walking movements on video and the analysis of footplacing is a perfect although time-consuming method for the evaluation of functional aspects of motor nerve recovery.

Functional assessment of sciatic nerve reconstruction: biodegradable poly (DLLA-epsilon-CL) nerve guides versus autologous nerve grafts.

The aim of this study was to compare functional nerve recovery after reconstruction with a biodegradable p(DLLA-epsilon-CL) nerve guide filled with modified denatured muscle tissue (MDMT), or an autologous nerve graft. We evaluated nerve recovery using walking track analysis (measurement of the sciatic function index [SFI]) and electrostimulation tests. Functional nerve recovery after reconstruction with a biodegradable p(DLLA-epsilon-CL) nerve guide filled with MDMT was faster when compared with nerve reconstruction using an autologous nerve graft. We conclude that in case of a short nerve gap in the rat, reconstruction can best be carried out using a p(DLLA-epsilon-CL) biodegradable nerve guide filled with MDMT.

Mortality in the long-stay population of all Dutch mental hospitals.

A study of 1,506 deaths reported over a period of 2 years to the National Psychiatric Case Register of the Netherlands, on the total cohort of 17,211 long-stay patients counted on prevalence day (31 December 1969), showed very much higher death-rates than in the general population. Malignancy and cardiac disease were not so common, while respiratory disease was still common in inpatients.