Variable fidelity of tissue-marking dyes in surgical pathology.

AIMS: Pathology specimens often contain important margins that must be identified from gross examination of specimens through to microscopic examination. Commonly, unique colours of tissue-marking dye (TMD) are applied to each margin, which facilitates both macroscopic and microscopic identification. Various techniques have been described, but the colour endurance and fidelity of TMDs following special tissue processing have not been addressed. The aim of this study was to evaluate the performance of various TMDs through decalcification and immunohistochemistry (IHC) protocols. METHODS AND RESULTS: Samples of TMDs from two manufacturers and acrylic artists' inks were obtained in seven colours and applied to excess non-diagnostic surgical pathology tissue. Tissues were subjected to a decalcification protocol or directly processed in a routine fashion. The presence and colour of TMD or ink were assessed on routine H&E sections and following IHC. Of the colours that reliably survived routine processing, loss of colour and colour change following decalcification and IHC protocols were seen with one manufacturer's product. CONCLUSIONS: TMD may lose or change its colour during special tissue processing. This previously unreported artefact may lead to potentially serious errors in margin assessment and reporting. Laboratories should evaluate TMDs and inks through routine processing, decalcification, and IHC protocols, to ensure colour endurance and fidelity.

Brainstem anatomy with 7-T MRI: in vivo assessment and ex vivo comparison.

BACKGROUND: The brainstem contains grey matter nuclei and white matter tracts to be identified in clinical practice. The small size and the low contrast among them make their in vivo visualisation challenging using conventional magnetic resonance imaging (MRI) sequences at high magnetic field strengths. Combining higher spatial resolution, signal- and contrast-to-noise ratio and sensitivity to magnetic susceptibility (χ), susceptibility-weighted 7-T imaging could improve the assessment of brainstem anatomy. METHODS: We acquired high-resolution 7-T MRI of the brainstem in a 46-year-old female healthy volunteer (using a three-dimensional multi-echo gradient-recalled-echo sequence; spatial resolution 0.3 × 0.3 × 1.2 mm3) and in a brainstem sample from a 48-year-old female body donor that was sectioned and stained. Images were visually assessed; nuclei and tracts were labelled and named according to the official nomenclature. RESULTS: This in vivo imaging revealed structures usually evaluated through light microscopy, such as the accessory olivary nuclei, oculomotor nucleus and the medial longitudinal fasciculus. Some fibre tracts, such as the medial lemniscus, were visible for most of their course. Overall, in in vivo acquisitions, χ and frequency maps performed better than T2*-weighted imaging and allowed for the evaluation of a greater number of anatomical structures. All the structures identified in vivo were confirmed by the ex vivo imaging and histology. CONCLUSIONS: The use of multi-echo GRE sequences at 7 T allowed the visualisation of brainstem structures that are not visible in detail at conventional magnetic field and opens new perspectives in the diagnostic and therapeutical approach to brain disorders. RELEVANCE STATEMENT: In vivo MR imaging at UHF provides detailed anatomy of CNS substructures comparable to that obtained with histology. Anatomical details are fundamentals for diagnostic purposes but also to plan a direct targeting for a minimally invasive brain stimulation or ablation. KEY POINTS: • The in vivo brainstem anatomy was explored with ultrahigh field MRI (7 T). • In vivo T2*-weighted magnitude, χ, and frequency images revealed many brainstem structures. • Ex vivo imaging and histology confirmed all the structures identified in vivo. • χ and frequency imaging revealed more brainstem structures than magnitude imaging.

Intratumoural immune signature to identify patients with primary colorectal cancer who do not require follow-up after resection: an observational study.

BACKGROUND: Following surgical and adjuvant treatment of primary colorectal cancer, many patients are routinely followed up with axial imaging (most commonly computerised tomography imaging) and blood carcinoembryonic antigen (a tumour marker) testing. Because fewer than one-fifth of patients will relapse, a large number of patients are followed up unnecessarily. OBJECTIVES: To determine whether or not the intratumoural immune signature could identify a cohort of patients with a relapse rate so low that follow-up is unnecessary. DESIGN: An observational study based on a secondary tissue collection of the tumours from participants in the FACS (Follow-up After Colorectal Cancer Surgery) trial. SETTING AND PARTICIPANTS: Formalin-fixed paraffin-embedded tumour tissue was obtained from 550 out of 1202 participants in the FACS trial. Tissue microarrays were constructed and stained for cluster of differentiation (CD)3+ and CD45RO+ T lymphocytes as well as standard haematoxylin and eosin staining, with a view to manual and, subsequently, automated cell counting. RESULTS: The tissue microarrays were satisfactorily stained for the two immune markers. Manual cell counting proved possible on the arrays, but manually counting the number of cores for the entire study was found to not be feasible; therefore, an attempt was made to use automatic cell counting. Although it is clear that this approach is workable, there were both hardware and software problems; therefore, reliable data could not be obtained within the time frame of the study. LIMITATIONS: The main limitations were the inability to use machine counting because of problems with both hardware and software, and the loss of critical scientific staff. Findings from this research indicate that this approach will be able to count intratumoural immune cells in the long term, but whether or not the original aim of the project proved possible is not known. CONCLUSIONS: The project was not successful in its aim because of the failure to achieve a reliable counting system. FUTURE WORK: Further work is needed to perfect immune cell machine counting and then complete the objectives of this study that are still relevant. TRIAL REGISTRATION: Current Controlled Trials ISRCTN41458548. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 2. See the NIHR Journals Library website for further project information.

Bowel cancer (also known as colorectal cancer) is the fourth commonest cancer in the UK. When the cancer is confined to the bowel and/or the surrounding lymph nodes (early bowel cancer), it is typically treated with an operation to remove the cancer with or without the addition of chemotherapy. Following this treatment, many patients will be cured, but in approximately one in five patients the cancer may come back (recur) either in the bowel or in another organ (e.g. the liver). Consequently, after treatment of early bowel cancer, clinicians often follow up patients in the hope of detecting any recurrent cancer at an early and treatable stage. For the four out of five patients whose cancer will never recur, this follow-up is unnecessary and burdensome on both the NHS and the patients. Better markers are needed to inform which patients do and do not need to undergo this surveillance. Over the last decade, evidence has accumulated to show that the way that a patient's immune system responds to a cancer influences the likelihood of the cancer recurring. It is plausible that those with the most immune cells in their cancer have such a small chance of recurrence that follow-up is not necessary. To validate this in an accurately followed-up population of patients with bowel cancer, we collected cancer tissue specimens from 701 patients in the Follow-up After Colorectal Surgery (FACS) trial and developed methods to count the number of immune cells in their cancers. At present, methods are still under development to automate the process. Indeed, if this were ever to become part of routine practice in NHS laboratories, then automation would be essential.

An assessment of chlorine stain and collegiate swimmers.

Background: Swimming is known worldwide as one of the healthiest, low-impact forms of exercise that promotes a strong body, heart, and mind. However, several studies have suggested that swimming pool chlorination is responsible for dental erosion, calculus formation, and stain in competitive and recreational swimmers, a phenomenon known as swimmer's mouth. The purpose of this observational study was to assess chlorine stain on the dentition of competitive female swimmers and divers from a university team and to determine if dental preventive practices affected chlorine stains. Methods: Swimmers were recruited from the University of New Mexico Swimming and Diving Team for this IRB-approved study (#17-481). Participants completed a questionnaire regarding individual oral habits and frequency of preventive visits. Following the questionnaire, an oral screening was completed to evaluate for stain. Fisher exact tests, nonparametric Wilcoxon tests, and descriptive statistics were used to analyse the data. Additionally, a cross-sectional analysis was used to compare the chlorine stain between divers and swimmers. Results: Twenty-one females, with a mean age of 20.5 years, participated in the study. One hundred percent of these subjects had staining of the teeth, despite the fact that 85% of them reported brushing their teeth 2 to 3 times per day, and 81% reported receiving regular dental prophylaxis. All participants swam 5 or more times every week, with practice length ranging from 1 to 2 hours. There were no differences in stain between collegiate swimmers and divers. Conclusion: Within this study sample, extrinsic staining of the teeth was identified on all swimmers and divers and the presence of stain was not prevented by the frequency of tooth brushing or professional stain removal. Additional oral hygiene regimens should be explored to facilitate the prevention or complete removal of swimmer stain.

Contexte: La natation est reconnue partout dans le monde comme l'une des formes d'exercice physique les plus saines et ayant le moins d'impact, qui renforce le corps, le coeur et l'esprit. Cependant, plusieurs études ont suggéré que la chloration des piscines cause l'érosion dentaire et la formation de tartre et de taches chez les nageurs compétitifs et récréatifs; un phénomène appelé la bouche de nageur. L'objectif de cette étude d'observation était d'évaluer les taches de chlore sur la dentition de nageuses et de plongeuses de compétition d'une équipe universitaire et de déterminer si les habitudes dentaires en matière de prévention influençaient les taches de chlore. Méthodologie: Les nageuses ont été recrutées de l'équipe de natation et de plongeon de l'Université du Nouveau-Mexique pour effectuer cette étude approuvée par le comité d'éthique médicale (#17-481). Les participantes ont répondu à un questionnaire à l'égard des habitudes buccodentaires personnelles et de la fréquence de leurs visites dentaires préventives. À la suite du questionnaire, un dépistage buccal a été effectué pour évaluer les taches. Les tests exacts de probabilité de Fisher, les tests non paramétriques de Wilcoxon et les statistiques descriptives ont été employées pour analyser les données. De plus, une analyse en coupe a servi à comparer les taches de chlore chez les plongeuses et les nageuses. Résultats: Vingt-et-une femmes âgées en moyenne de 20,5 ans ont participé à l'étude. La totalité des sujets avait des taches sur les dents, malgré le fait que 85 % d'entre elles ont signalé avoir brossé leurs dents 2 à 3 fois par jour et 81 % d'entre elles ont rapporté recevoir régulièrement des prophylaxies dentaires. Toutes les participantes ont nagé 5 fois ou plus par semaine et la durée de leur entraînement variait d'une à deux heures. Les nageuses et les plongeuses universitaires n'ont démontré aucune différence dans leur taux de taches. Conclusion: Parmi cet échantillon de l'étude, des taches extrinsèques ont été décelées sur les dents de toutes les nageuses et plongeuses, et la fréquence du brossage de dents ou l'élimination professionnelle des taches n'a pas empêché la présence de taches. Des mesures supplémentaires d'hygiène buccodentaire devraient être explorées afin de faciliter la prévention ou l'élimination complète des taches chez les nageurs.