Tissue microarray technique is applicable to bone marrow biopsies of myeloproliferative neoplasms

The Expression and Clinicopathological Significance of BRAF V600E and Mucin 6 in Intrahepatic Cholangiocarcinoma: A Retrospective Study

Aim. The study aims to explore the expression levels and clinicopathological significance of BRAF V600E and mucin 6 in intrahepatic cholangiocarcinoma. Method. Immunohistochemistry for BRAF V600E and mucin 6 was performed in 110 patients with intrahepatic cholangiocarcinoma. Subsequently, a comprehensive review of medical records and clinicopathological analysis was undertaken. Results. BRAF V600E expression was detected in 11 patients (10%); mucin 6 expression was observed in 19 intrahepatic cholangiocarcinoma specimens (17%). Thereafter, Cox regression models indicated that positive expression of either MUC6 positive (hazard ratio = 0.091, 95% confidence interval = 0.034-0.247, P < .001) and BRAF V600E positive (hazard ratio =0.150, 95% confidence interval = 0.058-0.388, P < .001) was significantly linked with longer overall survival for intrahepatic cholangiocarcinoma patients. Conclusion. The study concludes that positive expression of BRAF V600E and mucin 6 could potentially implied significant survival benefits for patients diagnosed with intrahepatic cholangiocarcinoma.

Tissue microarrays of bone marrow aspirate clot allow assessment of multiple samples

Time optimization and cost reduction without quality loss is fundamental for scientific production. The TMA technique allows large-scale analysis of paraffin-embedded and fixed tissues using non-decalcified bone marrow specimens. Cytoinclusion samples (n = 264) were selected from patients diagnosed with monoclonal gammopathy (n = 189) at Botucatu Medical School, São Paulo State University. Slides were cut from the TMA block and stained with H&E and immunohistochemical markers. Of the 276 fragments included in the receptor block, 45 core detachments were observed, thus 84% of the samples remained viable. The representative material allowed for adequate analysis of isolated cells, which showed nuclear, cytoplasmic and membrane staining. Thus, we verified that inclusion of bone marrow aspirate clot is a valid alternative for TMA histological and immunohistochemical analyses.

Imaging methods used to study mouse and human HSC niches: Current and emerging technologies

Bone marrow contains numerous different cell types arising from hematopoietic stem cells (HSCs) and non-hematopoietic mesenchymal/skeletal stem cells, in addition to other cell types such as endothelial cells- these non-hematopoietic cells are commonly referred to as stromal cells or microenvironment cells. HSC function is intimately linked to complex signals integrated by their niches, formed by combinations of hematopoietic and stromal cells. Studies of hematopoietic cells have been significantly advanced by flow cytometry methods, enabling the quantitation of each cell type in normal and perturbed situations, in addition to the isolation of these cells for molecular and functional studies. Less is known, however, about the specific niches for distinct developing hematopoietic lineages, or the changes occurring in the niche size and function in these distinct anatomical sites in the bone marrow under stress situations and ageing. Significant advances in imaging technology during the last decade have permitted studies of HSC niches in mice. Additional imaging technologies are emerging that will facilitate the study of human HSC niches in trephine BM biopsies. Here we provide an overview of imaging technologies used to study HSC niches, in addition to highlighting emerging technology that will help us to more precisely identify and characterize HSC niches in normal and diseased states.

A simple technique to construct tissue macroarrays

AIMS

In the diagnostic or research field, there is a need that the histopathological evaluation provides as much information as possible, with the shortest time and lowest cost. The development of the tissue microarray (TMA) technology has significantly facilitated and accelerated studies with tissue analyses using in situ technologies. Nevertheless, one of the most recognised limitations of TMA is that the small cores used to construct a TMA may not accurately represent characteristics of the whole tissue specimen. The aim is to present the technical aspects of a simple system to construct tissue macroarrays (TMaAs), its advantages and limitations, and some results of its use in for research purposes.

METHODS

The study presents three possibilities of preparing the specimens with up to 6 mm diameter to be included into the TMaA paraffin block using our method.

RESULTS

With this technique, it was possible to obtain glass slides with multiple whole fragments, which were used in five different studies.

CONCLUSIONS

We presented a method for construction of multi-TMaA paraffin blocks, which is very simple for optimising laboratory techniques requiring paraffin-embedded tissue sections and can be easily implemented in any institution with a histology laboratory.