Journal of Histotechnology最新文献

Cytology specimens and biopsy tissues are frequently small and pale, making them difficult to visualize grossly in paraffin. Ten dyes were assayed on small tissues to determine if specimen discernibility could be increased during the embedding and microtomy steps in the histological process. The ideal dye should not remain visible in a tissue section microscopically after subsequent staining and must not interfere with immunohistochemistry (IHC) assays. This study found that Harris hematoxylin and 1% aq. toluidine blue solution were the best labelers for gross tissue visualization and did not adversely affect post-processing staining and IHC assays.

Bladder urothelial carcinomas are diverse in terms of biological behavior and this reflects the underlying complex metabolic and molecular pathways. Novel biomarkers that could assist in the management and outcome prediction of bladder urothelial carcinomas are eagerly needed. Recently, overexpression of lysophosphatidylcholine acyltransferase 1 (LPCAT1), a key enzyme in lipid metabolism, has been implicated in the evolvement of several tumors. In this study, LPCAT1 immunohistochemical expression was evaluated and statistically analyzed in 60 bladder urothelial carcinomas in relation to other clinicopathological parameters including the patient outcome. Twenty non-neoplastic bladder tissues served as a control group. Cases were followed up for a mean period of 9 months. LPCAT1 was expressed in all bladder urothelial carcinoma cases with two distinct patterns designated as high and low nuclear expression. Low LPCAT1 nuclear expression was detected in urothelial carcinoma cases as compared to the control group. Similarly, low nuclear expression of LPCAT1 was associated with high grade and invasive tumors and could independently predict tumor recurrence and short survival. In conclusion, LPCAT1 downregulation might be involved in bladder urothelial carcinoma tumorigenesis and could contribute to tumor aggressive phenotype. Retained LPCAT1 expression is an independent predictor of tumor recurrence and it represents a promising prognostic marker for patients' risk stratification.

Tissue clearing technologies can greatly improve the depth and accuracy with which the three-dimensional structure of tissues, especially those of th*-e nervous system, can be visualized. A review of the present literature suggests that the growing diversity and sophistication of various approaches have contributed to the expansion of this method to a greater variety of tissue types, experimental conditions, and imaging modalities. In the proof-of-concept study presented in this paper, a simplified and modified version of the tissue clearing method CUBIC (clear, unobstructed brain imaging cocktails and computational analysis) was used in conjunction with fluorescent staining and immunohistochemistry to illustrate the three-dimensional structure and molecular characteristics of inflammatory and degenerative activity in the mouse optic nerve. Based on the studies summarized in this mini-review, and our impression from using the mCUBIC method, it appears that tissue clearing could be a viable approach revealing three-dimensional histological features of myelin-rich tissues under normal conditions and after injury.

Ergot alkaloids, a class of mycotoxins associated with ergotism, act as agonists on serotonin (5HT) receptors, specifically 5HT2a, which mediate smooth muscle contraction and vasoconstriction. The objective of this study was to examine the impact of ergot alkaloid exposure during mid and late gestation on microscopic placental structure and vascular development. Ewes were fed endophyte-infected tall fescue seed containing ergot alkaloids (E+/E+, 1.77 mg ewe^-1 d^-1) or endophyte-free tall fescue seed (E-/E-, 0 mg ergot alkaloids) during both mid (d 35 to d 85) and late gestation (d 86 to d 133). On d 133 of gestation, a terminal surgery was performed and two placentomes of the type B morphology were collected for microscopic analyses. Amorphous connective tissue regions were larger (p < 0.0001) and more numerous (p = 0.025) in the placentome of ergot alkaloid exposed ewes. Staining showed no difference (p = 0.83) in the number of vessels present, but luminal area of maternal vasculature was 117% greater (p < 0.0001) in ergot alkaloid exposed ewes. Results showed that exposure to ergot alkaloids during gestation slowed maturation of the fetal villi as indicated by greater amorphous connective tissue regions, and altered size and shape of blood vessels to counteract reductions in blood flow caused by vasoconstriction.

This review article traces the immunohistochemistry ancestry of cytotoxins as antibodies. The immunohistochemistry success, as a diagnostic and research test, stood on the shoulders of negative and positive experimentation results with cytotoxins from the first half of the twentieth century. This is when experimental immunologists came with the understanding of the need for both antigen and antibody purification to achieve specificity of the immunological reaction. Simultaneously, protocols were developed, which involved injecting antigenic material into experimental animals. During this time, reliable methods for evaluation of antiserum strength or titer were established. The evolution of antigen preparation for immunofluorescence is presented here as one of the transitional steps to modern immunohistochemistry. This work paved the way for the development of the monoclonal and polyclonal antibodies methodology. The article is written from the author's perspective as an experimental immunologist and a hands-on participant during many steps of development in modern morphological laboratory diagnostics. Knowledge of the roots of immunohistochemistry is useful for laboratory professionals in appreciation of predecessors' contributions. Familiarity with history of experimental immunology would be beneficial for understanding the methodological principles of their current work as well as future development prospects.

Mesenchymal cells (MSCs) are considered to be cellular populations of common embryological origin. For clinical research applications, MSCs are expanded and increased with cells obtained from a primary culture. By extracting cells from tissue and encouraging them to reproduce, the stem cell population ends up dominating the culture due to a high proliferation rate and self-renewal. The first subcultures between the third and sixth are chosen in order to obtain the maximum number of cells with optimal differentiation capacity. However, few studies have reported long-term cultivation of MSCs. The objective of this study was to advance the knowledge on the characteristics of MSCs by assessing their capacity for self-renewal and phenotypic maintenance beyond 50 cell subcultures, which is defined as the normal limit for cellular survival. Rat subcutaneous adipose tissue was the source of mesenchymal adipose stem cells (MASCs) cultured over 175 subcultures. Early 1 to 5 and late 25 to 30 subcultures were used to induce cellular differentiation to become adipogenic, chondrogenic and osteogenic connective tissue cells. MASCs characteristics were studied using flow cytometry, transmission electron microscopy (TEM), and immunohistochemical and reverse transcription polymerase chain reaction (RT-qPCR) assays. The MASCs maintained cell differentiation capacity for more than 30 subcultures but lost potentiality starting at 60 up to 175 subcultures. MASCs showed the embryonic phenotypes OCT3/4 and Nanog indefinitely, and developed compensatory mechanisms, such as autophagy, to achieve cell survival over a long time period. Therefore, long-term subcultures showed that MASCs could maintain their potential for clinical research use.