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CytoJournal 2022Liquid-based cytology (LBC) is a monolayer slide preparation technology that has outperformed conventional Pap smears because of improved fixation, decreased obscuring... (Review)
Review
Liquid-based cytology (LBC) is a monolayer slide preparation technology that has outperformed conventional Pap smears because of improved fixation, decreased obscuring factors, and standardized cell transfer. In LBC, samples are collected by completely immersing the sampling device into the company vial containing preservative fluid, whereby the cells are preserved and fixed simultaneously unlike conventional smears where the sample is smeared onto the glass slide and fixed separately. To date, two major liquid-based preparation methods are known - ThinPrep and SurePath. These two methods are different in their principles of cell harvesting but produce similar preparations. SurePath works on the principle of density gradient sedimentation. In this, a sample is vortexed and strained to break the mucus and large cell groups and then is treated through a density gradient centrifugation process to remove blood and debris. The cell pellet is resuspended and is allowed to sediment onto a glass slide. This is followed by staining on the PrepStain instrument. Government Medical College and Hospital, Nagpur, India, uses the SurePath method which was approved by FDA in the USA in 1999. Our institution uses Rovers Cervex-Brush to collect the cells from the transformation zone. This chapter describes the principle of SurePath and the processing of cervicovaginal specimen using the fully automated system in the laboratory.
PubMed: 35928530
DOI: 10.25259/CMAS_03_16_2021 -
Sensors (Basel, Switzerland) Nov 2022Eye tracking is a technology aimed at understanding the direction of the human gaze. Event detection is a process of detecting and classifying eye movements that are... (Review)
Review
Eye tracking is a technology aimed at understanding the direction of the human gaze. Event detection is a process of detecting and classifying eye movements that are divided into several types. Nowadays, event detection is almost exclusively done by applying a detection algorithm to the raw recorded eye-tracking data. However, due to the lack of a standard procedure for how to perform evaluations, evaluating and comparing various detection algorithms in eye-tracking signals is very challenging. In this paper, we used data from a high-speed eye-tracker SMI HiSpeed 1250 system and compared event detection performance. The evaluation focused on fixations, saccades and post-saccadic oscillation classification. It used sample-by-sample comparisons to compare the algorithms and inter-agreement between algorithms and human coders. The impact of varying threshold values on threshold-based algorithms was examined and the optimum threshold values were determined. This evaluation differed from previous evaluations by using the same dataset to evaluate the event detection algorithms and human coders. We evaluated and compared the different algorithms from threshold-based, machine learning-based and deep learning event detection algorithms. The evaluation results show that all methods perform well for fixation and saccade detection; however, there are substantial differences in classification results. Generally, CNN (Convolutional Neural Network) and RF (Random Forest) algorithms outperform threshold-based methods.
Topics: Humans; Eye Movements; Algorithms; Saccades; Neural Networks, Computer; Machine Learning
PubMed: 36433407
DOI: 10.3390/s22228810 -
Biopreservation and Biobanking Apr 2023This work investigates whether changes in a biospecimen's molecular composition from formaldehyde fixation drive changes in the mid infrared (MID-IR) spectrum. Our...
This work investigates whether changes in a biospecimen's molecular composition from formaldehyde fixation drive changes in the mid infrared (MID-IR) spectrum. Our ultimate goal was to develop an analytical metrology that could be used to accurately determine the fixation time of a tissue sample as a surrogate to overall tissue quality. Multiple unstained formalin-fixed paraffin-embedded tissue samples were scanned with an MID-IR microscope to identify a molecular fingerprint of formaldehyde fixation. The fixation specific patterns were then mined to develop a predictive model. A multiple tissue experiment using greater than 100 samples was designed to train the algorithm and validate the accuracy of predicting fixation status. We present data that formaldehyde crosslinking results in alterations to multiple bands of the MID-IR spectra. The impact was most dramatic in the Amide I band, which is sensitive to the conformational state of proteins. The spectroscopic fixation signature was used to train a machine-learning model that could predict fixation time of unknown tissues with an average accuracy of 1.4 hours. Results were validated by histological stain quality for bcl-2, FOXP3, and ki-67. Further, two-dimensional imaging was used to visualize the spatial dependence of fixation, as demonstrated by multiple features in the tissue's vibrational spectra. This work demonstrates that it is possible to predict the fixation status of tissues for which the preanalytics are unknown. This novel capability could help standardize clinical tissue diagnostics and ensure every patient gets the absolutely best treatment based on the highest quality tissue sample.
Topics: Humans; Tissue Fixation; Spectrophotometry, Infrared; Formaldehyde; Proteins; Machine Learning; Paraffin Embedding
PubMed: 36516138
DOI: 10.1089/bio.2022.0108 -
Veterinary Sciences Jan 2022Cetacean brain sampling may be an arduous task due to the difficulty of collecting and histologically preparing such rare and large specimens. Thus, one of the main...
Cetacean brain sampling may be an arduous task due to the difficulty of collecting and histologically preparing such rare and large specimens. Thus, one of the main challenges of working with cetaceans' brains is to establish a valid methodology for an optimal manipulation and fixation of the brain tissue, which allows the samples to be viable for neuroanatomical and neuropathological studies. With this in view, we validated a methodology in order to preserve the quality of such large brains (neuroanatomy/neuropathology) and at the same time to obtain fresh brain samples for toxicological, virological, and microbiological analysis (neuropathology). A fixation protocol adapted to brains, of equal or even three times the size of human brains, was studied and tested. Finally, we investigated the usefulness of a panel of 20 antibodies (neuromarkers) associated with the normal structure and function of the brain, pathogens, age-related, and/or functional variations. The sampling protocol and some of the 20 neuromarkers have been thought to explore neurodegenerative diseases in these long-lived animals. To conclude, many of the typical measures used to evaluate neuropathological changes do not tell us if meaningful cellular changes have occurred. Having a wide panel of antibodies and histochemical techniques available allows for delving into the specific behavior of the neuronal population of the brain nuclei and to get a "fingerprint" of their real status.
PubMed: 35202291
DOI: 10.3390/vetsci9020038 -
Cureus Feb 2023Silicone implants are one of the most widely used implants for facial augmentation, especially in the chin, mandibular angle, and malar area, utilizing different... (Review)
Review
Silicone implants are one of the most widely used implants for facial augmentation, especially in the chin, mandibular angle, and malar area, utilizing different surgical approaches. Despite their various advantages, many complications have also been reported, including hematoma, infection, bone resorption, numbness, displacement, and asymmetry. This study aims to evaluate the need for facial-implant fixation and compare and contrast fixated and nonfixated facial silicone implants in different facial sites. A narrative review of the topic of facial-implant stabilization using the PubMed database inclusion criteria included articles that discussed the topic of facial implants, were published in English, and included critical information such as the location of the implant, type of stabilization, follow-up periods, and complications. A total of 11 studies were included. Of these, two were prospective clinical studies, three were case series, and the remaining six were retrospective clinical studies. The studies were published between 1995 and 2018. The sample size varied from 2 to 601 cases. Stabilization includes suturing, monocortical screws, or no stabilization. Complications were reported in most of these studies, including asymmetry, bone resorption or erosion, displacement, dissatisfaction, edema, hematoma, infection, mucosal irritation, pain, and paresthesia. The follow-up period ranged from one month to 17 years. Despite the varied settings of these studies, silicone facial implant complications were reported in both fixated and nonfixated implants, with a lack of significant differences between fixated and nonfixated facial silicone implants regarding the method of fixation.
PubMed: 36874350
DOI: 10.7759/cureus.34524 -
Neuro-oncology Advances 2022There have been limited improvements in diagnosis, treatment, and outcomes of primary brain cancers, including glioblastoma, over the past 10 years. This is largely... (Review)
Review
There have been limited improvements in diagnosis, treatment, and outcomes of primary brain cancers, including glioblastoma, over the past 10 years. This is largely attributable to persistent deficits in understanding brain tumor biology and pathogenesis due to a lack of high-quality biological research specimens. Traditional, premortem, surgical biopsy samples do not allow full characterization of the spatial and temporal heterogeneity of glioblastoma, nor capture end-stage disease to allow full evaluation of the evolutionary and mutational processes that lead to treatment resistance and recurrence. Furthermore, the necessity of ensuring sufficient viable tissue is available for histopathological diagnosis, while minimizing surgically induced functional deficit, leaves minimal tissue for research purposes and results in formalin fixation of most surgical specimens. Postmortem brain donation programs are rapidly gaining support due to their unique ability to address the limitations associated with surgical tissue sampling. Collecting, processing, and preserving tissue samples intended solely for research provides both a spatial and temporal view of tumor heterogeneity as well as the opportunity to fully characterize end-stage disease from histological and molecular standpoints. This review explores the limitations of traditional sample collection and the opportunities afforded by postmortem brain donations for future neurobiological cancer research.
PubMed: 35047819
DOI: 10.1093/noajnl/vdab168 -
Current Pathobiology Reports 2018Studying and developing preanalytical tools and technologies for the purpose of obtaining high-quality samples for histological assays is a growing field. Currently,... (Review)
Review
PURPOSE OF REVIEW
Studying and developing preanalytical tools and technologies for the purpose of obtaining high-quality samples for histological assays is a growing field. Currently, there does not exist a standard practice for collecting, fixing, and monitoring these precious samples. There has been some advancement in standardizing collection for the highest profile tumor types, such as breast, where HER2 testing drives therapeutic decisions. This review examines the area of tissue collection, transport, and monitoring of formalin diffusion and details a prototype system that could be used to help standardize tissue collection efforts.
RECENT FINDINGS
We have surveyed recent primary literature sources and conducted several site visits to understand the most error-prone processes in histology laboratories. This effort identified errors that resulted from sample collection techniques and subsequent transport delays from the operating room (OR) to the histology laboratories. We have therefore devised a prototype sample collection and transport concept. The system consists of a custom data logger and cold transport box and takes advantage of a novel cold + warm (named 2 + 2) fixation method.
SUMMARY
This review highlights the beneficial aspects of standardizing tissue collection, fixation, and monitoring. In addition, a prototype system is introduced that could help standardize these processes and is compatible with use directly in the OR and from remote sites.
PubMed: 29780664
DOI: 10.1007/s40139-018-0170-1 -
Journal of the Experimental Analysis of... Nov 2022Eye-tracking has been used to investigate observing responses in matching-to-sample procedures. However, in visual search, peripheral vision plays an important role....
Eye-tracking has been used to investigate observing responses in matching-to-sample procedures. However, in visual search, peripheral vision plays an important role. Therefore, three experiments were conducted to investigate the extent to which adult participants can discriminate stimuli that vary in size and position in the periphery. Experiment 1 used arbitrary matching with abstract stimuli, Experiment 2 used identity matching with abstract stimuli, and Experiment 3 used identity matching with simple (familiar) shapes. In all three experiments, participants were taught eight conditional discriminations establishing four 3-member classes of stimuli. Four different stimulus sizes and three different stimulus positions were manipulated in the 12 peripheral test phases. In these test trials, participants had to fixate their gaze on the sample stimulus in the middle of the screen while selecting a comparison stimulus. Eye movements were measured with a head-mounted eye-tracker during both training and testing. Experiment 1 shows that participants can discriminate small abstract stimuli that are arbitrarily related in the periphery. Experiment 2 shows that matching identical stimuli does not affect discrimination in the periphery compared to arbitrarily related stimuli. However, Experiment 3 shows that discrimination increases when stimuli are well-known simple shapes.
Topics: Adult; Humans; Discrimination Learning; Visual Perception; Eye Movements
PubMed: 36053794
DOI: 10.1002/jeab.795 -
Medicina (Kaunas, Lithuania) Jul 2023: Stroke survivors commonly experience cognitive deficits, which significantly impact their quality of life. Integrating modern technologies like eye tracking into...
: Stroke survivors commonly experience cognitive deficits, which significantly impact their quality of life. Integrating modern technologies like eye tracking into cognitive assessments can provide objective and non-intrusive measurements. : This study aimed to evaluate the cognitive and visual processing capabilities of stroke patients using eye-tracking metrics and psychological evaluations. A cohort of 84 ischemic stroke patients from the N-PEP-12 clinical study was selected for secondary analysis, based on the availability of eye-tracking data collected during a visual search task using an adapted Trail Making Test. Standardized cognitive assessments, including the Montreal Cognitive Assessment (MoCA) and digit span tasks, were also conducted. : Correlation analyses revealed some notable relationships between eye-tracking metrics and cognitive measures, such as a positive correlation between Symbol Search performance and the number of fixations. Anxiety levels were found to be positively correlated with first fixation duration, while longer first fixation durations were associated with poorer cognitive performance. However, most correlations were not statistically significant. Nonparametric ANOVA showed no significant differences in fixation metrics across the visits. : These findings suggest a complex relationship between cognitive status, gaze fixation behavior, and psychological well-being in stroke patients. Further research with larger sample sizes and analysis of saccadic eye movements is needed to better understand these relationships and inform effective interventions for stroke rehabilitation.
Topics: Humans; Ischemic Stroke; Eye-Tracking Technology; Benchmarking; Quality of Life; Stroke
PubMed: 37629651
DOI: 10.3390/medicina59081361 -
Craniomaxillofacial Trauma &... Sep 2021Systematic review and meta-analysis. (Review)
Review
Is the Use of Intermaxillary Fixation Screws an Alternative to Erich Arch Bars for Maxillomandibular Fixation During Management of Maxillofacial Fractures? A Systematic Review and Meta-Analysis.
STUDY DESIGN
Systematic review and meta-analysis.
OBJECTIVE
Maxillomandibular fixation (MMF) is a step of paramount importance during the management of maxillofacial trauma. Erich arch bars are being used for this purpose for decades but with advances in maxillofacial trauma management, intermaxillary fixation screws came into existence and are being used routinely. The present study was designed to identify if the intermaxillary fixation screws are really an alternative to Erich arch bars for management of maxillofacial trauma.
METHODOLOGY
An exhaustive literature search was conducted in May 2020 on various electronic databases and studies comparing Erich arch bars and intermaxillary fixation screws were recruited for the analysis. Random-effects model with Mantel Haenszel statistics was used to analyze oral hygiene and duration of achieving MMF.
RESULTS
A total of 96 studies were identified, out of which 8 studies were included in the meta-analysis. There was no statistically significant difference in oral hygiene status of the patients in both the groups. Intermaxillary fixations screws required statistically significantly less time in achieving MMF. Needle stick injury was prominently seen with the use of Erich arch bar whereas other complications like mucosal coverage, root injury, screw loosening and screw fracture makes the use of intermaxillary fixation screws questionable.
CONCLUSION
The present meta-analysis suggests that there is not enough evidence to recommend the use of intermaxillary fixation screws as an alternative to Erich arch bars. Further research with large sample size, high quality evidence and better methodology is recommended in this direction.
PubMed: 34471480
DOI: 10.1177/1943387520971410