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Cellular composition of rat bone marrow stroma. Antigen-defined subpopulations.

Although stromal cells establish the architecture of mammalian bone marrow and organize hemopoiesis, the interrelationships among their macrophage, fibroblastic, endothelial, and adipocyte-like components are not wholly understood. Using murine monoclonal antibodies to cultured adherent cells of rat bone marrow, we observed that the predominant fibroblastoid cells grown from marrow differed from those of non-hemopoietic organs. The marrow type bore a detectable quantity of the ST3 but not ST4 antigen, whereas those from lung, diaphragm, and epididymal fat pad, bore more ST4 than ST3. Those from spleen were an equal mix of both types. Although the tissue distribution of the ST3 antigen was similar to that of Thy-1, it was not identical, and in the brain, the two structures were localized in different areas. While none of the ST3, ST4 (fibroblast directed), or BN(MB)35 (myeloid directed) antibodies recognized fat cells cultured from marrow, the ST10 antibody, selected for binding to marrow derived fat cells, stained peripheral adipose cells, unidentified aglobular cells in areas of fat cell formation, and macrophages, but not fibroblasts. On the basis of these observations, we suggest that the fibroblastoid cells of the marrow are different from those of non-hemopoietic tissues.

Adipose Tissue↗

[Flow fluorimetry of the cellular DNA of the bone marrow in normal mice and after exposure to extreme factors].

The distribution of murine bone marrow cells in regard to cell cycle was examined using flow cytometry technique. In normal NIH mice the percentage of cells being into phases G1/0, S and G2 + M constitutes 78, 15 and 7%, respectively. In mice subjected to X-irradiation (2, 12 Gy), the thermal burn, and X-irradiation plus the burn the proportion of G2 + M-cells increased, which may be presumably due to their delay on stage G2 of the cell cycle. The start and duration of the delay in the G2 phase depend upon the kind of damage applied.

Animals↗

Separation of normal human bone marrow cells by counterflow centrifugal elutriation. I. Morphological analysis and subfractionation of neutrophilic granulocytes.

We have used counterflow centrifugal elutriation to separate the nucleated cells of normal human bone marrow into their major morphologically identifiable cellular components. Human bone marrow cells were separated simultaneously into the major cell types--lymphocytes, monocytes, granulocytes, and erythroid precursors. Significant concentration of bone marrow cell types could be achieved, including myeloblasts (x 25), promyelocytes (x 43), early myelocytes ( x 22), late myelocytes (x 17), metamyelocytes (x 6), eosinophils (x 40), basophils (x 55), erythroblasts (x 35), monocytes (x 40), and plasma cells (x 35). Cell loss is minimal (85% recovery of input) and random, and cell viability, as measured by trypan blue staining, is high (greater than 95%). Factors interfering with separation are also described: a low loading flow rate, the presence of an excess of mature red cells, and the absence of fetal calf serum resulted in poor cell recovery and viability. The use of heparin as the anticoagulant resulted in cell loss, decrease in cell viability, and an ineffective separation. Separation of cells from normal bone marrow by centrifugal elutriation should facilitate the study of bone marrow cell interactions and the purification of individual types of bone marrow cells.

Bone Marrow↗

[Mechanism of changing the cellular composition of the bone marrow during experimental toxic diphtheria].

Hemopoietic shifts in the bone marrow under experimental diphtheria intoxication have been studied. The number of immature elements of the erythroid series was shown to be lowered in the presence of an increase in the granulocyte pool. Under these conditions the erythroid sprout did not respond to bloodletting and the number of reticulocytes in the peripheral blood significantly dropped. However, there was an increase in the inclusion of 59Fe in red cells. The adrenomimetic ephedrine raised the content of reticulocytes in blood and 59Fe inclusion in red cells in the experimental animals and stimulated the reproduction of the erythroid series cells.

Animals↗

[Cellular structures formed during bone marrow cultivation in agar].

The growth-enhancing effect and the differentiation of colonies formed by native and frozen-thawed myelokaryocytes in semiliquid agar were observed over a period from the 2nd to the 28th day. The cultivation of bone marrow in agar was shown to form colonies consisting of haemopoietic cells as well as of stromal elements. Under the cultivation of frozen-thawed bone marrow, the retardation of proliferative activity of growing cells was observed within up to 4 days. Later on the proliferative character and the rate of the myelokaryocytes of both the types were seen identical. The question of a possible existence of haemopoietic tissue and stromal elements in the progenitor cells of normal bone marrow is being discussed.

Agar↗

Mediatory role of stem cell derived cells in LPS-induced splenic CFUs accumulation.

Injection of bacterial lipopolysaccharides (LPS) in LPS-responsive mice produces a transient increase of CFUs in spleen and blood but not in bone marrow. The cellular aspects of the mechanism underlying this response of the hemopoietic system to LPS were investigated. Bone marrow cells from LPS-high responder mice (BMC-H) of the C3Heb/FeJ and C57BL/ScSn strains were transferred to lethally irradiated histocompatible LPS-low responder C3H/HeJ and C57BL/10/ScCr mice and vice versa. Six to ten weeks after reconstitution recipient mice were tested with LPS. Six days after injection of LPS, CFUs numbers in blood and spleen of low-responders reconstituted with BMC-H showed a 10-17 fold increase compared with PBS-injected controls. Lethally irradiated LPS high-responders reconstituted with low-responder bone marrow cells (BMC-L) still produced a small but significant increase of splenic and blood CFUs numbers. These results suggest that relatively radioresistant stem cell-derived cells play an important role in the generation of a stimulus inducing the splenic CFUs accumulation following LPS injection. The decrease of femoral CFUs numbers was less prominent in mice reconstituted with BMC-L than in those reconstituted with BMC-H. Thus expression of the LPS locus is evident in both medullary and extra-medullary sites.

Animals↗

Contribution to some radiobiological aspects of the investigation of chemical radiosensitizers of hypoxic cells. Part V: Metronidazole--dependence of its radiosensitizing effect on the dose, time interval of administration and hypoxia degree of the bone marrow evaluated according to the changes of its cellularity in rats.

In the experiments on female rats of Wistar strain the effect of metronidazole (Entizol - Polfa) was studied administrated in aqueous solution with a gastric pipette into the stomach. Dependence was analyzed on the dose of metronidazole, on the time interval of administration before irradiation and on the degree of hypoxia of bone marrow during irradiation induced in the lower part of the body and graded by the abdomen compression with an inflatable rubber cuff with overpressure 4, 6.7, 13.3 and 20 kPa. The effect of whole body irradiation (60Co source) was evaluated according to the changes of bone marrow cellularity (BMC) the third day after irradiation. The sensitizing effect of metronidazole increases rapidly up to dose of 30 mg/kg with rising dose of the drug, then at higher doses only slowly. With prolonging interval of the application of 600 mg/kg body weight the sensibilization increases and reaches the peak after 1-2 hours, then it gradually decreases till the complete disappearance after 10-15 hours. In both cases irradiation was carried out at abdomen compression corresponding to 20 kPa of overpressure in the rubber cuff. The induced hypoxia of bone marrow demonstrated a significant, protective effect, corresponding to the degree of abdomen compression which was reduced by metronidazole administration in the dose of 600 mg/kg. The reduction represents one half to one third of the protective value and is proportional to the degree of induced bone marrow hypoxia during irradiation.

Animals↗

[Apoptosis and proliferative activity of bone marrow cells in patients with aplastic syndromes as evidenced by trephine biopsy].

AIM: To clarify the effect of cyclosporin A (CSA) on the apoptosis and proliferative activity of bone marrow cells in patients with aplastic syndromes by trepanobiopsy evidence. MATERIALS AND METHODS: The TUNEL immunohistochemical assay was used to study apoptosis of bone marrow cells in the histological specimens from 24 patients: 8 with refractory anemia (RA), 8 with acute small-proportion leukemias [RA with excessive blasts (RAEB) + RAEB in transformation (RAEBt)], 3 with acute non-lymphoblastic leukemia (ANLL), 5 with lymphogranulomatosis (LGM). Control apoptosis examination was made in 10 patients treated with CSA. The proliferative activity of bone marrow cell was evaluated by bone marrow histological specimens from 10 patients (8 patients with RA and 2 with RAEB + RAEBt) at the onset of disease and during CSA therapy in the immunohistochemical test with primary nuclear antigen Ki-67 antigen antibodies. Changes in the proliferative activity and degree of apoptosis of bone marrow cells were assessed in relation to the cellularity detectable by the histological specimens. RESULTS: Patients with RA showed an increase in bone marrow cell apoptosis to 25.375 +/- 6.874 (-10.8 +/- 5.122 and 8.333 +/- 5.84 in controls and ANLL patients, respectively). The cells of hemopoiesis and stromal microenvironment are in the process of cell death. Higher bone marrow cellularity is observed in CSA-treated patients at clinical and hematological remission, which is followed by rises in the index of proliferation and the degree of apoptosis. CONCLUSION: The clinical effect of CSA in patients with aplastic syndromes is induced by its direct or mediated stimulating effect on pluripotent stem cells of hemopoiesis, by increasing bone marrow cellularity at the expense of clonal and/or normal hemopoiesis.

Acute Disease↗

Bone induction by implants coated with cultured osteogenic bone marrow cells.

The availability of osteoinductive coatings on dental and orthopedic implants will result in an improved fixation of these devices. Those cases where implants are placed in poor-quality bone or where high failure rates are obtained are especially expected to gain from such coatings. This paper presents a novel, biological approach to obtain bioactive and osteoinductive coatings on bone-replacement implant materials. This so-called tissue engineering approach utilizes osteogenic bone marrow cells that are cultured on an implant material to form a bone-like tissue. The implant materials used herein included porous calcium phosphate scaffolds and metallic plates, the latter of which were coated with a biomimetic calcium phosphate coating to facilitate cellular attachment. Bone marrow cells were obtained from a variety of species, including humans, and were grown to facilitate cellular proliferation. The cells were subsequently seeded onto the implants and cultured for an additional week to facilitate osteogenic differentiation and extracellular matrix production. The resulting hybrid implants, encompassing the biomaterial carrier and cultured bone-like tissue, were subsequently implanted subcutaneously in nude mice for 4 weeks, followed by histological examination for de novo bone formation. The results revealed that newly formed bone was seen both in porous implants and on flat metallic surfaces. This bone tissue engineering approach, therefore, offers great potential to enhance bony healing around implants in a compromised bone bed.

Aged↗

The accuracy of 111InCl3 as a bone marrow scanning agent.

The number of normal cellular elements present in bone marrow biopsies was compared to the extent of uptake at corresponding sites on 111InCl3 bone marrow scans in 87 patients with malignant lymphoma. Of the biopsies free of tumor, 49/54 interpreted as normocellular and 16/17 hypocellular or aplastic confirmed the scan interpretation. Of the biopsies demonstrating tumor, 10/11 of those interpreted as normocellular and 14/15 hypocellular or aplastic confirmed the scan interpretation. The 111InCl3 bone marrow scan is accurate in depicting the presence or absence of normal marrow elements, but is of value in detecting tumor only when the normal elements are extensively replaced.

Biopsy↗