Comparative characteristics of bone marrow cell composition, stroma, and trabecular bone in allogenic hematopoietic stem cell transplantation in patients with primary myelofibrosis

Introduction. Primary myelofibrosis (PMF) is a clonal disease violating the cell composition, histological topography and stroma in bone marrow (BM). Allogeneic haematopoietic stem cell transplantation (allo-HSCT) is a curative therapy in PMF.Aim — description of change in the haematopoietic tissue cell composition and stroma, as well as in trabecular bone in allo-HSCT patients with fibrotic PMF.Materials and methods. We studies 24 trephine biopsy samples from nine PMF patients with allo-HSCT at the intervals: I — 1 month prior to, II — past 1–3 months and III — past 4–6 months from allo-HSCT. BM trephine biopsy slides were prepared in a standard histological assay with haematoxylin—eosin and additional staining with Gomori’s silver and Masson’s trichrome. Morphological change was evaluated in reticulin and collagen stroma, bone trabeculae, cellularity and topography of haematopoietic tissue.Results. The BM trephine biopsies of interval I were morphologically distinguished in three types by haematopoietic cellularity, stromal and trabecular sclerotic change. Post-transplant intervals II and III (3–6 months after allo-HSCT) did not reveal these types but showed an evident myelofibrosis and osteosclerosis reduction and signs of a restoring bone remodelling cycle. Myelopoietic lineages recovered in stages: the erythroid germ restored in three, granulocytic — in six months, and megakaryocytic cellularity did not fully recover in six months. Myelopoietic cellularity recovery outpaced blood recovery, which may be due to induced myelodysplasia or disruption of stromal niches.Conclusion. Allo-HSCT leads to the disappearance of PMF-pathognomonic BM morphology reflecting a histological remission. The reduction of myelofibrosis and osteosclerosis and normalisation of the trabecular bone remodelling cycle in post-transplant periods indicates an impact of cell microenvironment on PMF pathogenesis and warrants research into the composition and histological topography of cell microenvironment in PMF.

Rate and Structure of Mortality from Malignant Neopasms of Lymphatic and Haematopoietic Tissue in the Regions of the Republic of Bashkortostan (2006–2015)

Introduction. An urgent issue facing contemporary medicine is the problem of cancer. According to official Russian Federation statistical data, of the 2,132,050 deaths recorded in 2015, 286,900 of them resulted from cancer. In this connection, an analysis of mortality due to malignant neoplasms of lymphatic and hematopoietic tissues is a relevant activity.Materials and methods. We analysed data showing the dynamic rate and structure of mortality from malignant neoplasms of lymphatic and haematopoietic tissues in the Republic of Bashkortostan both of the population as a whole and persons of working age. Data covering the period 2006–2015 was derived from the Federal State Statistics Service for the Republic of Bashkortostan.Results and discussion. As a result of the research, an increase in the overall intensive mortality rates from malignant neoplasms of lymphatic and haematopoietic tissues was noted along with an absence of significant differences between the indicators in the Republic of Bashkortostan and those for the Russian Federation as a whole. Our work has shown that malignant neoplasms of haematopoietic and lymphoid tissues are the leading medical and social problem of contemporary oncology.Conclusion. This work was carried out in order to identify the most common clinical cases of malignant tumours of haematopoietic and lymphoid tissue, as well as to predict the incidence and further planning of specialised haematological care to the population.

MECHANISMS IN ENDOCRINOLOGY: Bone marrow adiposity and bone, a bad romance?

Bone marrow adipocytes (BMA-) constitute an original and heterogeneous fat depot whose development appears interlinked with bone status throughout life. The gradual replacement of the haematopoietic tissue by BMA arises in a well-ordered way during childhood and adolescence concomitantly to bone growth and continues at a slower rate throughout the adult life. Importantly, BM adiposity quantity is found well associated with bone mineral density (BMD) loss at different skeletal sites in primary osteoporosis such as in ageing or menopause but also in secondary osteoporosis consecutive to anorexia nervosa. Since BMA and osteoblasts originate from a common mesenchymal stem cell, adipogenesis is considered as a competitive process that disrupts osteoblastogenesis. Besides, most factors secreted by bone and bone marrow cells (ligands and antagonists of the WNT/β-catenin pathway, BMP and others) reciprocally regulate the two processes. Hormones such as oestrogens, glucocorticoids, parathyroid and growth hormones that control bone remodelling also modulate the differentiation and the activity of BMA. Actually, BMA could also contribute to bone loss through the release of paracrine factors altering osteoblast and/or osteoclast formation and function. Based on clinical and fundamental studies, this review aims at presenting and discussing these current arguments that support but also challenge the involvement of BMA in the bone mass integrity.

Whole-mount in situ hybridization: minimizing the folding problem of thin-sheet tissue-like crayfish haematopoietic tissue

Crayfish haematopoietic tissue (HPT) has a thin-sheet-like structure with a thickness of 100-160 μm and a width of approximately 1-2 cm. This structure makes HPT extremely easy to fold after removal from the animal. Therefore, it is difficult to handle the tissue without folding when processing for sectioning and histological study. The degree of tissue folding reflects the size of the tissue sections obtained, how complicated it is to interpret the location of each tissue section, and the accuracy of the interpretation of the location of a specific transcript. To facilitate the interpretation of a specific transcript location in the HPT, we optimized a whole-mount in situ hybridization technique to minimize tissue folding. This optimized protocol effectively reduced the tissue folding. Therefore, the location of a specific transcript in the HPT was easily and accurately defined. This protocol will be useful for whole-mount staining of other tissues with similar structure.

Excretion

Excretion is the removal of metabolic wastes such as ammonia, carbon dioxide, ions and water as well as toxic xenobiotics and metals. The process involves the gills, kidney, liver and rectal gland (elasmobranchs and coelacanth). In the liver, amino acids, haemoglobin, steroids and molecules resulting from human activities are transformed to excretable products. The rectal gland excretes ions, notably Na+ and Cl−. The kidney in teleosts has a distinction between an anterior head-kidney containing haematopoietic tissue and endocrine tissue and the posterior region with nephrons (kidney tubules). Fish nephrons generally have a Malphigian corpuscle with a glomerulus but the structure varies between fish taxa and some marine teleosts lack a glomerulus. Control systems for fish excretion are unclear but it is expected that various hormones influence excretory homeostasis.

334 FACTORS AFFECTING HEMATOPOIETIC ENGRAFTMENT OF MONKEY EMBRYONIC STEM CELLS IN SHEEP FETUSES

Previously, we generated monkey/sheep haematopoietic chimeras by in utero transplantation (IUT) of monkey embryonic stem (ES); however, the factors that control how the ES cells successfully engraft and differentiate into haematopoietic tissue in sheep fetuses remain uncertain. Here, we examined factors that might influence donor cells and recipient sheep and affect successful ES cell engraftment. We transplanted either undifferentiated monkey ES cells or ES-derived cells at an early haematopoietic differentiation stage into sheep fetuses. The latter cells were allowed to differentiate by culturing on OP9 cell layers for 6 days. Cells were transplanted into the liver or subcutaneous tissue of recipient sheep fetuses at 43 to 50 or 51 to 67 days of gestation (full term = 147 days) using ultrasound to identify the site for transplantation. After birth, monkey haematopoietic engraftment in the bone marrow was analysed in 40 lambs using colony-PCR with cells grown in methylcellulose in the presence of defined cytokines; teratoma formation was analysed by biopsy and immunohistochemistry. We found that haematopoietic engraftment was only observed when ES-derived cells at the early differentiation stage were transplanted into fetal livers at 51 to 67 days of gestation (6/9). However, teratoma formation with mature monkey tissue structures was only observed following transplantation of undifferentiated ES cells into fetal subcutaneous tissues at 43 to 50 days of gestation (4/6), but that was not observed when both types of cells were transplanted into the liver (0/18) or at 51 to 67 days of gestation (0/24). These results demonstrate that the differentiation status of the donor cells, the transplantation site, and the age of the fetus at transplantation are important factors in engraftment and differentiation into haematopoietic tissue or teratoma formation in sheep fetuses.