Histology Technicians Research Articles

Optimization of Tissue Handling and Processing in the Era of Precision Medicine: A Practical Recommendation from a Multidisciplinary Panel of Indian Experts

AbstractMolecular analysis of biospecimens is the key to diagnostic and therapeutic decisions in clinical practice. However, there is a lack of consolidated guidelines for biospecimen collection, tissue handling, and storage in India. Therefore, this study aims to generate expert recommendations for the optimization of tissue handling and processing practices in India in the era of precision medicine. This study aimed to evaluate the clinical gaps related to tissue handling for molecular analysis and develop expert recommendations to mitigate preanalytical issues associated with biospecimen processing. These expert recommendations will help in increasing the diagnostic yield and accuracy of biomarker testing in clinical practice. A virtual advisory board meeting was convened with 19 experts, including pathologists, molecular biologists, medical oncologists, surgical oncologists, interventional radiologists, and a senior histology technician from 10 hospitals in India, along with an accreditation officer for testing and calibration of laboratory procedures. The scientific coordinators developed specific questions to address the salient issues associated with the preanalytic phase of tissue specimen preparation. The experts discussed each question until a complete set of recommendations was obtained. The expert panel provided recommendations for tissue collection, processing, fixation, and block preparation to ensure high-quality biospecimens. As per the expert panel recommendations, tissue sampling can be performed from any easily accessible site, regardless of the primary or metastatic locations. In addition, the cold ischemia time should be <1 hour, 10% neutral-buffered formalin should be used as the fixative, isopropyl alcohol should be used as the dehydrating agent, the volume of tissue to fixative ratio should be 1:10, and all the paraffin blocks should be archived in dry, pest-free conditions at room temperature. The experts suggested that the formalin used for fixation should be freshly prepared and its pH should be checked daily; moreover, the pH and date of formalin preparation should be mentioned on the containers. The experts highlighted the need to educate multidisciplinary teams on the optimization of tissue handling practices and emphasized that a pathologist should always check the tissue for adequate quality and quantity for biomarker testing. The existing routine clinical procedures for collecting and handling biospecimens adversely affect their quality. The expert recommendations for preanalytical quality control would ensure high-quality biospecimens for molecular analysis and precision medicine.

Effect of Formaldehyde on The Structure of The Lung and Heart and The Possible Protective Effect of Omega- 3 (Histological and immune-histochemical study)

Background: Formaldehyde (FA) is a common indoor and outdoor pollutant found in many products. The toxicity of formaldehyde is of concern to all who work closely with it such as embalmers, anatomists, histology technicians, and medical students. Omega-3 in fish oil is one of the most important polyunsaturated fatty acids (PUFA) that have anti-inflammatory and antioxidant activity. Materials and methods: Thirty adult male albino rats were divided into three equal groups. Group, I was a control group, Group II rats were exposed to formaldehyde inhalation for 4 weeks. Group III were exposed to formaldehyde inhalation and were administered orally with a 300mg/kg/day Omega-3 for 4 weeks. After 24 hr of the last dose, the animals were dissected. Hearts and lungs were processed for examination after Haematoxylin and eosin, Masson trichome and immunohistochemical stains. Results: The rats treated with formaldehyde inhalation showed significant changes in the normal architecture of both lung and heart. The lung showed congestion and mass appeared on one lobe and increase in the area percent of collagen fibers. Immune-expression of tumor necrosis factor-alpha (TNF-α), and caspase- 3 were increased in the lung and heart compared to the control. Omega-3 fatty acids can ameliorate the pathological changes, decrease the fibrosis and the immune-expression in both lung and heart. Conclusion: Formaldehyde was associated with many histopathological changes in both lung and heart and the Omega-3 can ameliorate these changes.

Polarized light and the magic angle: Scientists making artPolarized light and the magic angle: Scientists making art

Masterpiece microscopy Chris King is a histology technician at the National Institutes of Health, near Washington, D.C. He enjoys his work, which features heavy use of microscopy, but used to find it hard to explain what he does to friends and family. “So I started taking pictures of some of the tissue stains and other things at work, and they seemed to get it better,” he says. Soon he was doing experiments to see how he could manipulate various substances to produce interesting colors and shapes. His family was interested in what he was doing, so they helped him get his own microscope at home. He picked up other used lab equipment on eBay. Now his lab-studio dominates his apartment. “It’s in part of my bedroom, and then most of the kitchen, and the dining room is pretty much dedicated to it.” King tells Newscripts that most of his time

Opening a histopathology laboratory in Kampala Uganda – from the ground up

Cancer is an increasing threat to the health of individuals in low- and middle-income countries (LMIC), with two-thirds of cancer cases projected to occur in these regions by 2020. With growing options for cancer treatment in LMIC, establishing an accurate pathologic diagnosis of cancer is an urgent global health priority but is not possible in many LMIC. The Fred Hutchinson Cancer Research Center has a longstanding collaboration with the Uganda Cancer Institute (UCI) located in Kampala, Uganda. In May 2015, state-of-the-art cancer treatment, research, and education center was opened on the UCI campus that includes outpatient adult and pediatric clinics, research clinic, training facilities, chemotherapy infusion rooms, and diagnostic laboratories including a histopathology lab. Extensive efforts were made to build the capacity to provide accurate histologic diagnoses for cancer at the new facility. These efforts included extensive planning during the construction of the new facility to accommodate a histopathology laboratory, training of histology technicians, developing resource-appropriate laboratory protocols, identifying sources for high-quality reagents, consumables and equipment support, and rigorous quality control. These activities have resulted in a functional laboratory capable of grossing, fixation, paraffin processing, embedding, sectioning, and basic staining (hematoxylin and eosin) of clinical specimens to render cancer diagnoses in Uganda. Future capabilities of the laboratory will seek to expand staining to include immunohistochemistry, and to build the infrastructure for robust telepathology with international colleagues.

First ladies in laying the foundation of neuroendocrinology

Although women were welcomed into medical practice in increasing numbers by the close of the nineteenth century, it was not until the second quarter of the twentieth century that they were recognised as valuable collaborators and contributors in the nascent field of neuroendocrinology, wherein they soon made advances that have stood the test of time. Mary Pickford at Edinburgh measured the action of acetyl choline in the supraoptic nucleus of the hypothalamus and helped to establish that vasopressin and oxytocin are formed in separate and distinct neurons. Berta Scharrer, like her future husband Ernest Scharrer, was born in Munich. Their great contribution was the proof that the posterior pituitary is not a gland, but the location of the release into the circulation of vasopressin and oxytocin from fibres in the hypothalamico-hypophysial tract. Their work succeeded in establishing against high-powered, vehement opposition the value of histological evidence in elucidating synthesis, storage and release of secretion from neuro-endocrine cells. A Rockefeller travelling fellowship allowed Marthe Vogt to move from Berlin in 1932 to London and then to Cambridge. The relations between the cortex and medulla of the suprarenal gland and the control of adrenocorticotropin were her main concerns. Dora Jacobsohn emigrated to Sweden after graduating in Berlin in 1934. She investigated control of the anterior pituitary gland by the hypothalamus, and co-operated with Geoffrey Harris in establishing the role of the hypothalamico-hypophysial portal venous system that conveys the releasing factors that preside over anterior pituitary cells. Laboratory discoveries do not constitute the whole of science, for the interpretation of evidence and recognition of general principles deserve attention. Dorothy Price, from Aurora, Illinois, received her BS in 1922 at the University of Chicago, and was glad to find employment as a histology technician in the zoology laboratory, where she was quietly appropriated by Carl Moore (1892-1955), an investigator seeking the key to hormonal control of gonadal function. The burning question was the part played by what was (then) called hormone antagonism in the biology of the testis. Price recognised that the common factor in explaining the deleterious effects of oestrin and testosterone on the testes could be traced to the anterior pituitary: the pituitary controlled testicular secretion, and the male hormone in turn controlled gonadotropin release in the pituitary. This seesaw balance explained the problem, and was the first of many regulatory systems to be recognised as ensuring stability--and later became known as negative feedback. The contributions of these five women helped place neuro-endocrinology on a firm foundation for its later expansion.

Evaluation of a completely automated tissue-sectioning machine for paraffin blocks

Tissue-sectioning automation can be a resourceful tool in processing anatomical pathology specimens. The advantages of an automated system compared with traditional manual sectioning are the invariable thickness, uniform orientation and...

Standardizing Rodent Trimming and Embedding Guidelines for Histology: Improving Efficiency in the Laboratory

This poster will outline a process created in the histology laboratory to standardize trimming and embedding guidelines to maintain consistency throughout all studies. Pathologists requested that each tissue be assigned a fixed number for more-efficient slide evaluations. For example, all brains are numbered as cassette one and all pituitary glands are numbered cassette two, etc. To achieve this, a template was created for both the rat and mouse for the histology technicians to use. The template consists of photographs demonstrating tissue trimming and grouping in the order of how the pathologists evaluate the hematoxylin and eosin (H&E) slides. A trim form is created in the web-based client application system, listing the tissues requested for each individual animal. Once this has been completed, the system sorts the original trim form to group all cassettes according to tissue. For example, all cassettes numbered one are grouped together (brains) and all cassettes numbered two are grouped together (pituitary glands), etc. By following this process, improved consistency and efficiency has been noticed by the pathologists. In the future, this template system has the potential to facilitate histopathology digital image database archive and search processes.

Medical education in the digital age: Digital whole slide imaging as an e-learning tool: From the 1st Digital Pathology Summit, New Frontiers in Digital Pathology, University of Nebraska Medical Center, Omaha, Nebraska 14-15 May 2010

The visual aids used in teaching and lecturing to students have clearly evolved over the last several decades. Illustrations on paper were replaced by carousels full of photographic slides, which in turn have been supplanted by Powerpoint™ presentations. At an arguably much slower pace, the method of teaching microscopic anatomy to students of the healthcare professions is also changing. For the majority of medical students graduating before 2000, the microscope and accompanying boxes of glass slides were the standard tools for learning both histology and pathology. Studying for exams also included reviewing kodachromes showing static fields-of-view at predetermined magnifications. Both of these methods of learning required the student to be physically present on campus. Pathology residents, when not learning at the microscope with the attending pathologist, must rely on teaching sets of glass slides that cannot leave the department. Group learning must either be done at a multiheaded microscope (which many times has fewer heads than people present) or by use of video technology attached to the microscope. With the advent of digital whole slide imaging (WSI) over the past several years, there is an opportunity to revolutionize the way teaching and learning are done for all students of medicine including doctors, nurses, medical technicians, histology technicians, cytology technicians, and others. Comparison of Digital Whole Slide Images with Glass Slides There are many advantages to using WSI when compared with traditional glass slides [Table 1]. Digital images can be standardized; all students will study the exact same tissue section. Sections on glass slides are inherently variable in quality and content.[1] Although admittedly subtle in some cases, these variabilities can be eliminated with digital imaging. The quality of the image can also be indefinitely maintained compared to glass slides that are vulnerable to fading, breaking, and vanishing.[2] One very helpful aspect of digital images is the use of a thumbnail image. As students are examining the image at higher magnification, they can always refer to the thumbnail for orientation.[3] This obviously is impossible with glass slides. Glass slides cannot be easily annotated with any precision, relying on relatively crude “dotting” for the purposes of highlighting a certain area of the slide. Digital images can have multiple annotations including arrows, circles, text, etc. placed exactly where needed. Portability is another benefit of using digital images. The use of microscopes obligates a student to remain on campus in order to study, review, etc. With WSI loaded onto a web-based server, study can occur wherever and whenever the student wishes.[2] WSI also makes simultaneous viewing of a particular field-of-view possible; a major advantage over glass slides. Viewing the image on a common computer monitor encourages discussion and collaboration between classmates.[1] Finally, storage of WSI becomes a matter of having enough server memory. As server space becomes less and less expensive, the cost and effort of storing and maintaining both the microscopes and glass slide sets will become comparatively more burdensome.[3] Some disadvantages that have become apparent with WSI include the dependence of the image quality on monitor resolution and the challenge of scanning tissue sections that have artifacts such as folds, etc.[3] Judicious choice of an acceptable non-cost prohibitive monitor is essential for an accurate image. As digital scanners become “smarter”, the flaws in a slide will likely become less of an issue. Table 1 Benefits of digital slide imaging

Contact Dermatitis from Acrylics in a Histology Laboratory Assistant

The use of acrylics has expanded enormously, resulting in a vast range of products for both occupational and non-occupational purposes. Acrylics reported to cause allergic contact dermatitis in histology technicians are 2-hydroxyethyl methacrylate and 2-hydroxyethel acrylate.

Immunohistochemistry and Hematoxylin and Eosin on the Same Slide

Abstract Small tissues are always difficult to work with. The limited size often leads to many technical problems. In spite of the care normally given to a specimen, the unthinkable can happen. A block may be cut through, slides may be broken, and sections may fall off. When this type of tragedy occurs, the creativity and technical abilities of a histology technician are often tested. An example of this occurred when a technician was cutting a prostate biopsy. Two slides were taken, with two sections on each. The slides were taken, with two sections on each. The slides were stained with hematoxylin and eosin (H&E), and coverslipped with a Tissue Tek automatic coverslipper. This coverslipper uses a plastic film, which causes the film to adhere to the slide with xylene. The slides were then given to the pathologist who then requested an immunohistochemical (IHC) test to be performed. In the process, the specimen was exhausted.

Possible preferential metabolism of xylene isomers following occupational exposure to mixed xylenes.

Solvent exposures commonly involve mixtures of substances or mixtures of isomers of a single solvent. These may be metabolised through common pathways, resulting in the potential for metabolic interactions. These may then lead to accumulation of solvent or metabolic intermediates, some of which may be toxic. This paper describes a pilot study conducted to determine the correlation between airborne xylene isomers and the appearance of methylhippuric acid (MHA) isomers in urine of workers exposed mainly to xylene. The project also aimed to determine whether there is preferential metabolism of any isomer by comparison of the ratios of airborne isomers with the ratios of metabolite isomers appearing in urine. A total of 12 workers (11 male, 1 female) were recruited into this study, with 2 of the participants providing samples on more than one occasion. Workers included flooring contractors (5), printers (2), chemical manufacturers (2), histology technicians (2) and one householder using a xylene-based varnish. Subjects were aged between 24 and 48 years (37.6+/-2.0 years; mean +/- SEM). After giving informed consent, workers provided a prework and postwork urine sample on a midweek work day. Samples were stored frozen prior to analysis. Breathing-zone air samples were collected using personal air samplers at 50 ml/min. Solvents were trapped on activated-charcoal sampling tubes. Subjects wore pumps for 18-304 (178+/-24) min on the same day on which urine samples were collected. Xylene exposures ranged from 1.6 to over 7000 ppm. In all, 7 of 16 measurements exceeded the Australian TWA standard of 80 ppm. Two of the flooring contractors wore respiratory protective equipment (RPE) and the two histopathology technicians used workplace ventilation systems. Total urinary MHA output ranged from 10 to 8000 mmol/mol creatinine, with 6 of 16 samples exceeding the modified biological exposure index of 702 mmol/mol. Correlations between airborne concentrations of individual xylene isomers and their corresponding MHA isomers were poor but improved when workers using RPE were excluded from the analysis. Gradients of the regression lines (millimoles of MHA per mole of creatinine per parts per million of xylene) were 3.2 for o-isomers, 7.0 for p-isomers, and 14.4 for m-isomers. Comparisons of isomer ratios of xylene in air were made with the corresponding ratio of MHA isomers in urine. These revealed higher ratios of m-MHA to other MHA isomers than those of m-xylene to the other xylene isomers. The MHA isomer ratios were expected to be the same as the airborne xylene isomer ratios if there were no preferential elimination of any isomer. m-MHA appeared in urine in a greater proportion than would be predicted from the proportion of m-xylene detected in air. The time course of the appearance of MHA isomers in urine also suggests that interactions were taking place, with m-MHA appearing in high proportion in urine following several days of repeated heavy xylene exposure. On a single moderate exposure, m-MHA appeared initially in high proportion in the first few hours but was undetectable in urine after 18 h. p-MHA was detectable for up to 6 h after exposure, and o-MHA remained detectable after 18 h. This study suggests that excretion of m-MHA in urine is favoured over that of the other isomers following exposure to mixed xylenes. This is independent of airborne xylene isomer composition and suggests that the metabolism of m-xylene occurs preferentially to that of the other isomers. It is not clear at which step in the metabolism of xylene this preference occurs, although other work indicates that the initial oxidation of xylene to methylbenzyl alcohol by cytochrome P450 2E1 occurs at the same rate for each isomer. These findings suggest that there is potential for metabolic interactions between xylene isomers and that these may be the basis for xylene toxicity.

Post-exposure prophylaxis after accidental prion inoculation

Although human prion diseases, such as Creutzfeldt-Jakob disease (CJD), are undoubtedly infectious, human-to-human transmission has been observed only under exceptional circumstances. However, the recognition of new variant CJD, raises the possibility that these diseases may become more prevalent, and lead to an increased risk of iatrogenic transmission and infection due to occupational exposure. Risk groups include neurosurgeons and other operating theatre staff, pathologists and morticians, histology technicians, and laboratory workers. Although there have been only occasional reports of CJD in individuals occupationally exposed to human prions to date, the above considerations prompt us to consider the possibility of postinoculation prophylaxis. THE LANCET

Effects on neurobehavioral performance of chronic exposure to chemically contaminated well water.

Occupational exposure to trichloroethylene (TCE) and other solvents impairs neurobehavioral performance. Use of well water contaminated with TCE and solvents has been associated with excessive symptoms, cancers, birth defects and impaired blink reflex. We extended these observations by measuring the neurophysiological (NPH) and neuropsychological (NPS) status of subjects who used water contaminated with 6 to 500 ppb of TCE for 1 to 25 years. The 170 well-water exposed subjects who resided in southwest Tucson, Arizona overlying the Santa Cruz River aquifer, were compared to 68 referent subjects for NPH and NPS tests. Also, 113 histology technicians (HT) were referents for blink reflex latency only. Affective status was assayed by a Profile of Mood States (POMS). Exposed subjects were statistically significantly impaired when compared to referents for NPH tests. These impairments included sway speed with eyes open and closed, blink reflex latency (R-1), eye closure speed, and two choice visual reaction time. NPS status was statistically significant impaired for Culture Fair (intelligence) scores, recall of stories, visual recall, digit span, block design, recognition of fingertip numbers, grooved pegboard and Trail making A and B. POMS scores were elevated. Prolonged residential exposure to well-water containing TCE at lower levels than occupational exposures, but without time away from exposure for metabolism and excretion of toxins, was associated with neurobehavioral impairment.

Neurobehavioral effects of formaldehyde and solvents on histology technicians: Repeated testing across time

Neurobehavioral functions were studied by periodic testing of 318 histology technicians and by a single session testing 494 of such technicians from 1982 through 1986. Tests included immediate recall of stories, of drawings, and of number series from the Wechsler Memory Scale, block designs from the Wechsler Adult Intelligence Scale (WAIS), slotted pegboard, trail making A and B, embedded figures, number writing on the fingers, visual simple and two-choice reaction times, balance (speed of body sway), and the profile of mood state (POMS) score. Mean test scores of four initial "first test" groups were not different from 1982 to 1986. Immediate recall of stories and drawings improved on the first retest as did the block design score. Other test scores showed insignificant variation over the 4 years, including memory for numbers forward and backward, trails A and B, number writing on fingers, radius of body sway, and choice reaction time. Only placing of pegs in the pegboard took longer. POMS score was lower in the second year in naive subjects and decreased from 39 to 13 in those retested. Variations in results of neurobehavioral tests given at intervals across 4 years were small. No cumulative effects of occupational exposures or of aging were found. However, small decreases may have been offset by increases due to test familiarity or learning.

Pulmonary function in histology technicians compared with women from Michigan: effects of chronic low dose formaldehyde exposure on a national sample of women.

Pulmonary function in histology technicians compared with women from Michigan: effects of chronic low dose formaldehyde exposure on a national sample of women.

Pulmonary function in histology technicians compared with women from Michigan: effects of chronic low dose formaldehyde on a national sample of women.

Chronic workplace exposure to formaldehyde and solvents at low doses reduced pulmonary function in 280 non-smoker white women working as histology technicians. They were studied during national workshops at four United States cities for four years. Height and age adjusted comparisons of pulmonary function were made with women in a stratified random population sample of Michigan and with a selected subset of the population that was used to model predictive pulmonary equations for function. The major functional change in histology technicians was a steeper decrement in vital capacity and flows from age 20 to 60 by regression analysis than occurred in the modelled Michigan population. Furthermore non-smoking and currently smoking women studied at two sites had significantly lower flows than were found in the sample of Michigan women. There was no consistent effect of an aerosol bronchodilator on flows of women at the four sites. Diffusing capacity for carbon monoxide single breath and alveolar volume were below the comparison group of Michigan women only when tested at Washington DC.

An examination of factors that could affect choice reaction time in histology technicians.

Histology technicians exposed to formaldehyde and solvents have symptoms and objective evidence of neurobehavioral impairment of memory, judgment, and equilibrium. Because reaction time has been prolonged in many groups of workers exposed to toxicants, choice reaction time was measured in 385 female formaldehyde and solvent-exposed histology technicians, and 79 unexposed female laboratory workers. Choice reaction time to a visual stimulus (CRT) is defined, for the purpose of this study, as the time required for discriminated cancellation of two different letters on a microcomputer screen by pressing the matching keys. Initial analysis showed that increases in age, years of cigarette smoking, and hours per day of formaldehyde exposure significantly lengthened CRT, but xylene-toluene exposure had no effect. Since duration of smoking and length of daily formaldehyde exposure were age related, multiple linear regression analysis of CRT was performed using them as independent variables. Increasing age was the only significant factor in lengthening CRT. However, in these female histology technicians, the second measurement one year later was 44 msec faster (p less than .04). The reason for improved performance is unclear, but it may be an effect of training encompassing familiarity, improved attention, or learning.

Formaldehyde impairs memory, equilibrium, and dexterity in histology technicians: effects which persist for days after exposure.

Results of neurobehavioral testing in 305 histology technicians were studied by regression analysis with age, years of cigarette smoking, and hours per day of exposure to formaldehyde and to solvents as major independent variables. Increasing age was associated with poorer performance on visual memory, block design, trails, dexterity by pegboard, sharpened-Romberg, finger writing, as well as with longer choice reaction time. Increased daily hours of exposure to formaldehyde were correlated with reduced performance on story memory, visual memory, digit span, pegboard and sharpened-Romberg, as well as with errors on trails. Exposure to solvents was associated only with diminished recall of story.

Pulmonary and neurobehavioral effects of formaldehyde exposure.

Two groups of male workers who were exposed to formaldehyde, the first group in phenol-formaldehyde-plastic foam matrix embedding of fiberglass (batt making), and the second in the fixation of tissues for histology, were studied for work-related neuro-behavioral, respiratory, and dermatological symptoms; and for pulmonary functional impairment. Forty-five male fiberglass batt makers who were studied across the initial work-shift after a holiday had average frequencies of combined neurobehavioral, respiratory, and dermatological symptoms of 17.3 for the hot areas and 14.7 for the cold areas of the process. Their symptom counts were significantly greater than those for 18 male histology technicians who averaged 7.3, and for 26 unexposed male hospital workers who averaged 4.8. During their first workshift after holidays, 58% of the batt makers had a decrease in one or more tests of pulmonary function. Nine nonsmokers had decreases more frequently than did 35 smokers; forced expiratory volume in one second FEV1.0 decreased in 16%, diffusing capacity for carbon monoxide (sb) decreased in 30%, forced expiratory flow 25-75 decreased in 16%, and forced expiratory flow) 75-85 decreased in 36%. Thirty-five percent of all 44 men had drops in FEV1.0, forced vital capacity, or in diffusing capacity (sb).

Neurobehavioral and respiratory symptoms of formaldehyde and xylene exposure in histology technicians.

Disturbances of memory, mood, equilibrium, and sleep that occurred simultaneously with headache and indigestion, were experienced more frequently among women working in histology who had daily exposure to formaldehyde, xylene, and toluene than in unexposed female clerical workers working in the same hospitals. Neurobehavioral symptoms were accompanied by irritation of eyes, upper airways, and trachea. Formaldehyde exposure correlated better with neurobehavioral symptoms and with respiratory and mucous membrane symptoms than did exposure to xylene/toluene or to other agents.