PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “bone marrow cellularity”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 793 records · Page 44Linked to original sources

Modulation of lymphohematopoiesis in long-term cultures by gamma interferon: direct and indirect action on lymphoid and stromal cells.

Gamma interferon (IFN-gamma) is the product of multiple cell types within the bone marrow microenvironment and has been demonstrated to act as a potent inhibitor of myelopoiesis in vitro and in vivo. The action of this cytokine on lymphohematopoiesis has now been examined on both long-term bone marrow cultures and representative cloned cellular components of the bone marrow microenvironment. In myelopoietic (Dexter) cultures, the half maximal inhibitory concentration of IFN-gamma was between 1 and 10 U/mL. In comparable lymphopoietic (Whitlock/Witte) cultures, IFN-gamma inhibited the production of B-lineage lymphoid cells with a half maximal effective concentration of less than 1 U/mL. In a clonal assay for pre-B cells, IFN-gamma inhibited colony formation with a half maximal concentration of 1 to 5 U/mL. Not all B-lineage lymphoid cells displayed the same sensitivity, however. Growth of the IL-7-dependent B cell line (2E8) in methylcellulose assays was unaffected by IFN-gamma while the replication of other lymphoid lines was partially or completely inhibited. IFN-gamma induced the expression of cell surface proteins (MHC Class I and II) on both B-lineage cells and stromal cells. In cloned stromal cell lines, IFN-gamma increased the steady state mRNA levels for the cytokines interleukin-6 (IL-6) and JE, a member of the IL-8 family. These data indicate that IFN-gamma acts within the lymphohematopoietic microenvironment through both direct and indirect actions on the hemopoietic and stromal cell populations.

Animals↗

The nature of an accessory cell in bone marrow stimulating murine megakaryocytopoiesis.

The nature of accessory cells in unstimulated mouse bone marrow that modulates in vitro megakaryocytopoiesis by releasing megakaryocyte potentiator (Mk-potentiator) activity was investigated. An active cell class was identified by the 7/4 and Ia cellular antigens. Bone marrow macrophages were obtained by their defined outgrowth in the presence of growth factors. Bone marrow macrophages grown in the presence of interleukin 3 (IL-3) were more active in producing Mk-potentiator than were macrophages grown in the presence of colony-stimulating factor 1 (CSF-1). The data indicate that the accessory cells producing Mk-potentiator are a select population of bone marrow macrophages that may be responsible for inducing megakaryocyte maturation under steady-state conditions.

Animals↗

Varicella zoster infection after bone marrow transplantation: incidence, risk factors and complications.

The cellular immunoincompetence which follows bone marrow transplantation (BMT) allows both primary and reactivation infection with herpes viruses. We report the overall incidence and timing of varicella zoster virus (VZV) infections after BMT, including the clinical course, complications and associated clinical risk features. Of 1186 patients undergoing BMT through 1989, 216 patients developed VZV infection between 4 days and 10.8 years after BMT; 86% of them within the first 18 months. Of all patients transplanted, 15 +/- 3% by 6 months and 52 +/- 14% by 5 years had developed VZV infection. Dermatomal zoster represented 62% of the infections, while 32% had complicated VZV infection--CNS, disseminated or visceral zoster. All serious infections occurred within 7 months of BMT but only two patients died, both from VZV pneumonitis. Allogeneic and autologous recipients had a similar incidence of VZV infection. VZV seropositive patients had more frequent, earlier and often more complicated or disseminated infections. Age > or = 10 years and radiation in the pre-transplant conditioning were significantly and independently associated with higher rates of VZV infection within a multivariate regression model. Using this model, we could define clinical risk groups with distinctly different hazards of VZV infection: age > 10 years, radiation pre-BMT and VZV seropositive patients had a 44% incidence by 3 years versus age < 10 years, no radiation and VZV seronegative had a 0% incidence by 3 years. Acyclovir assigned for prophylaxis of CMV or HSV infection had no effect on the timing or incidence of VZV infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Acyclovir↗

Hematopoietic reconstitution after bone marrow transplantation: assessment with MR imaging and H-1 localized spectroscopy.

Magnetic resonance (MR) studies were performed in 14 patients as early as possible (21-110 days) after bone marrow transplantation (BMT). MR characteristics of lumbar vertebral bone marrow were studied with T1-weighted spin-echo imaging, water- and fat-selective imaging with a frequency-selective excitation technique, and point-resolved spatially localized proton spectroscopy. Signals from water and fat protons and their T1 and T2 values were analyzed. Water proton signal intensity correlated well with cellularity within bone marrow, as determined with parallel iliac crest biopsies. The fraction of signal from water in red bone marrow of patients with allogeneic transplants from siblings (four cases) was significantly higher than in four patients with autologous transplants. The latter showed very low cellularity in the period of about 4 weeks after BMT because of the cytotoxic pretreatment of the bone marrow. The MR results in six patients with allogeneic transplants from unrelated donors ranged widely, depending on the complications after BMT. Analysis of data obtained with the different techniques showed that water- and fat-selective MR imaging and spectroscopic methods are useful for noninvasive monitoring of hematopoietic reconstitution after BMT.

Adolescent↗

[Myelodysplastic syndromes in the aged].

Seventy-five cases of myelodysplastic syndromes (MDS) in the aged (over 60 years) were analysed for hematological findings, immunological parameters and response to treatment in respect to prognostic significance. They were diagnosed according to the FAB classification, but patients with hypoplastic marrow were included if myelodysplasia was evident. Thirty-four percent of patients with primary acquired refractory anemia (PARA) or primary acquired sideroblastic anemia (PASA), and 36% of patients with RA with excess of blasts (RAEB) had hypoplastic bone marrow. The positive rates of antinuclear antibody in PARA or PASA, and of rheumatoid factor in PARA or PASA and in RAEB were higher than those in normal aged controls. Cellularity of bone marrow was inversely related to the length of survival. Among the patients with PARA or PASA, survival time was significantly longer in the group of hypoplastic bone marrow than in the group of hyper- or normo-plastic bone marrow, and in the group of good responder to treatment than in the group of poor responder and nontreated patients.

Aged↗

The morphological studies on M2/t(8; 21) acute nonlymphocytic leukemia.

Bone marrow studies including morphological, morphometrical and ultrastructural aspects were performed in 35 patients with M2/t(8; 21) and 23 patients with M2/NN. It was found that M2/t(8; 21) patients had higher cellularity in bone marrow. Type (II) myeloblast cells were predominant among myeloblasts. Deformation of nuclei, nucleocytoplasmic asynchronism and dysmegakaryocytopoiesis were more evident in M2/t(8; 21) than in M2/NN patients.

Bone Marrow↗

Hypocellular myelodysplastic syndromes (MDS): new proposals.

To determine whether hypocellular MDS differs from normo/hypercellular MDS, we attempted to identify hypocellular MDS cases either by correcting the bone marrow (BM) cellularity by age (28 patients) or by using a single arbitrary value of BM cellularity (25 patients) and compared these two groups of hypocellular cases to the normo/hypercellular MDS cases (72 patients). 18 patients were common to both hypocellular groups. Patients with hypocellular MDS in both of these selected groups have similar features with regard to age and sex distribution, peripheral blood and bone marrow parameters, FAB subtypes, karyotypes, leukaemic transformation, and survival. However, the median age of patients in < 30% BM cellularity group was higher than those patients in the age-corrected group (69 years v 62 years). The selection of < 30% cellularity excluded 10 cases in the age group < 70 years but included another seven patients in the age group of > 70 years. However, correction of BM cellularity by age revealed that those included patients (selected for < 30% cellularity) who had normocellular BM by their age. Therefore we recommend the age-correcting grouping to ensure comparable series for comparison, for response to treatment, and survival. Finally, BM cellularity does not appear to be an important factor on prognosis in MDS, because patients with hypocellular MDS in both selected groups have similar prognosis to those with normo/hypercellular MDS patients.

Adult↗

Coexistence of donor and host T lymphocytes following HLA-different bone marrow transplantation into a patient with cellular immunodeficiency and nonfunctional CD4+ T cells.

We report the outcome of a non-T-cell-depleted bone marrow transplant from an HLA partially incompatible, MLR-positive, parental donor in a patient with an unusual form of immunodeficiency characterized by a lack of CD8 T cells and a failure of the CD4 cells to display functional activity in vitro. Without conditioning, and following a mild and transient GVHD, donor T cells persist in trace amounts in the host, where they coexist with the nonfunctional host T cells and cooperate with host APC in antigen recognition, thereby leading to a reconstitution of T cell functions in vitro and in vivo and development of a stable, so far unprecedented, human T-T split chimera across MHC barriers.

Antigens, Differentiation, T-Lymphocyte↗

Preclinical protocol for in vivo selection of hematopoietic stem cells corrected by gene therapy in Fanconi anemia group C.

Fanconi anemia (FA) is an autosomal recessive disorder characterized by birth defects, increased incidence of malignancy, progressive bone marrow failure, and cellular hypersensitivity to DNA cross-linking agents. Bone marrow transplantation is therapeutic and therefore FA is a candidate disease for hematopoietic gene therapy. We have previously used mitomycin C (MMC) to achieve in vivo selection of wild-type hematopoietic stem cells (HSC) transplanted into FANCC knockout mice. However, clinical application of MMC in human FA gene therapy is unlikely because of its unknown toxicity profile in human FA patients. In contrast, cyclophosphamide (CPA) and gamma-irradiation (IR) are already in use with human FA patients and we therefore tested these regimens for their ability to achieve selection of genetically corrected HSCs in vivo. We found that nonmyeloablative doses of CPA or IR or combinations of CPA + IR were highly efficient at achieving in vivo selection of transplanted wild-type HSC. Furthermore, this nontoxic regimen also selected FANCC-mutant HSC corrected by ex vivo retroviral gene therapy. We suggest those nontoxic doses of CPA and/or IR could also be used to enhance gene therapy in human FA patients.

3T3 Cells↗

Effect of lithium carbonate on the bone marrow of patients treated for haematological malignancies.

Patients suffering from haematological malignancies were treated with Li2CO3 in order to investigate its effect on the bone marrow depleted by cytotoxic therapy. The results revealed that lithium induced a great number of cells, especially myeloids, in the previously hypoplastic bone marrow. There was a close relationship between the cellularity of the bone marrow and the changes in peripheral WBC and granulocyte counts during lithium carbonate treatment.

Antineoplastic Agents↗

[Changes in mouse erythropoiesis during continuous irradiation with a daily dose of 957 mGy].

Quantitative and qualitative changes in the blood producing organs and in the peripheral blood of mice are evaluated in this paper. The animals were irradiated for 42 days continually with a daily dosage of 957 mGy. Until the 7th day of irradiation a significant diminution of the cellularity of the bone-marrow and of the cellularity as well as the mass of the spleen could be observed. After the 14th day or irradiation a temporary stabilization of the cell number in the bone-marrow could be found until the 28th day, after that time there was a moderately strong decrease. The cellularity and the mass of the spleen increased temporarily until the 28th day of irradiation because of erythropoiesis and myelopoiesis increasing from 20% to 50%. The most significant changes in the peripheral blood could be observed in not granulated cells as a kind of sudden and permanent decrease. The diminution of the granulocyte and reticulocyte number proceeded somewhat more slowly, temporarily revealing an increasing tendency on the 28th day of irradiation. The erythrocyte numbers as well as the haematocrit and haemoglobin values decreased continually beginning from the 7th day of irradiation until the death of the test animals.

Animals↗

Isolation of hemopoietic stem cell subsets from murine bone marrow: II. Evidence for an early precursor of day-12 CFU-S and cells associated with radioprotective ability.

Counterflow centrifugal elutriation (CCE) in combination with plastic adherence and fluorescence-activated cell sorting were used consecutively to enrich functionally different subpopulations of pluripotent hemopoietic stem cells (HSC) from mouse bone marrow. The nonadherent CCE fractions were labeled with wheat germ agglutinin (WGA)-fluorescein isothiocyanate (FITC) and sorted according to differences in fluorescence within various windows on the basis of forward (FLS) and perpendicular (PLS) light scatter. The sorted cells were then assayed for their (1) in vivo colony-forming ability (day-7 and day-12 spleen colony-forming units [CFU-S]), (2) radioprotective ability (RPA; 30-day survival), and (3) their ability to repopulate the bone marrow or spleen over a 13-day period with day-12 CFU-S, granulocyte-macrophage colony-forming units (CFU-GM), nucleated cells, or cells associated with RPA. The highest incidence of day-12 CFU-S and cells with RPA was obtained by sorting the most WGA-positive cells with relatively high PLS (enrichment, 50- to 200-fold), lowering the effective dose (ED 50/30) to an average of 80 cells. The separative procedure enabled hemopoietic stem cells that repopulate both bone marrow and spleen with secondary RPA cells, CFU-S-12, and CFU-GM to be enriched and separated from part of the RPA cells, CFU-S-12, and cells that reconstitute the cellularity of bone marrow and spleen. These data suggest that cells generating both day-12 CFU-S and RPA cells differ from day-12 CFU-S and RPA cells themselves on the basis of PLS characteristics and affinity for WGA. Such early stem cells have also been detected in sorted fractions meeting the FLS/PLS characteristics of lymphocytes.

Animals↗

Mesoangioblasts, vessel-associated multipotent stem cells, repair the infarcted heart by multiple cellular mechanisms: a comparison with bone marrow progenitors, fibroblasts, and endothelial cells.

OBJECTIVE: To test the potential of mesoangioblasts (Mabs) in reducing postischemic injury in comparison with bone marrow progenitor cells (BMPCs), fibroblasts (Fbs), and embryonic stem cell-derived endothelial cells (ECs), and to identify putative cellular protective mechanisms. METHODS AND RESULTS: Cells were injected percutaneously in the left ventricular (LV) chamber of C57BL/6 mice, 3 to 6 hours after coronary ligation, and detected in the hearts 2 days and 6 weeks later. Echocardiographic examinations were performed at 6 weeks. LV dilation was reduced and LV shortening fraction was improved with Mabs and BMPCs but not with ECs and Fbs. Donor cell colonization of the host myocardium was modest and predominantly in the smooth muscle layer of vessels. Capillary density was higher in the peripheral infarct area and apoptotic cardiomyocytes were fewer with Mabs and BMPCs. Mabs and BMPCs, but not Fbs or ECs, promoted survival of cultured cardiocytes under low-oxygen in culture. This activity was present in Mab-conditioned medium and could be replaced by a combination of basic fibroblast growth factor (bFGF), insulin-like growth factor (IGF)-1, and hepatocyte growth factor (HGF), all of which are produced by these cells. Conditioned medium from Mabs, but not from Fbs, stimulated proliferation of smooth muscle cells in vitro. CONCLUSIONS: Mabs appear as effective as BMPCs in reducing postinfarction LV dysfunction, likely through production of antiapoptotic and angiogenic factors.

Animals↗

An enhanced immunocytochemical method for staining bone marrow trephine sections.

AIMS: The detection of cellular antigens in fixed decalcified bone marrow trephine (BMT) sections depends on the method of processing, the nature of the antigen and antibody, antigen retrieval techniques, and the sensitivity of the immunocytochemical method. This study evaluated a tyramide enhanced avidin-biotin immunostaining method on formalin fixed decalcified BMT sections to determine whether the method could detect previously undetectable antigens. METHODS: Nineteen BMT biopsies from a range of haematological disorders were evaluated with 43 antibodies to haemopoietic antigens using horseradish peroxidase and alkaline phosphatase detection methods, using the tyramide enhanced avidin-biotin immunostaining method. RESULTS: Compared with standard avidin-biotin immunostaining methods the tyramide enhanced immunostaining method showed enhanced signal intensity, gave positive labelling for antigens that require pretreatment by other methods, and previously unreactive antigens were detected. Primary antibodies could be used at up to 200 times higher dilutions. CONCLUSION: The tyramide enhanced immunostaining method, while retaining specificity, is highly sensitive and enables an increased number and range of antigens to be detected than previously possible. The method could be applied to BMT sections for the routine diagnosis and classification of haematological disorders.

Antibodies, Monoclonal↗

Bone-marrow imaging in pure red blood cell aplasia.

Bone-marrow scintigraphy with indium chloride in 111 was performed on a patient with pure red blood cell aplasia before and after successful treatment with immunosuppressive drugs. The return of erythroid precursors to the bone marrow was accompanied by a substantial increase in the marrow uptake of 111In. The distribution of 111In in the posttreatment scan was indistinguishable from that of 52Fe. These results indicate that indium chloride in 111 is a useful agent for the delineation of erythroid cellularity within bone marrow.

Adult↗

Bone structure and turnover in the distal radius and iliac crest: a histomorphometric study.

In bone grafting procedures of the wrist, the distal radius would be a more convenient graft donor site than the conventionally used iliac crest. We compared tetracycline-labeled bone biopsies from these two sites in 18 white patients (12 males, 6 females, aged 26-66 years) undergoing bone grafting procedures of the wrist. Fourteen had had previous trauma, 1 osteonecrosis of the lunate, 2 mild rheumatoid arthritis, and 1 a brachial plexus palsy. The specimens were processed undecalcified and examined by routine histomorphometry for bone structure, static and dynamic bone turnover variables, and marrow cellularity. We found that bone from the distal radius had thinner cortices (p = 0.0001), lower bone volume (p = 0.01), thinner trabeculae (p = 0.029), greater trabecular separation (p = 0.015), and lower wall thickness (p = 0.0001), marrow cellularity (p = 0.0001), osteoid volume (p = 0.01), osteoid surface (p = 0.02), osteoid thickness (p = 0.0002), osteoblast surface (p = 0.001), eroded surface (p = 0.01), osteoclast surface (p = 0.012), mineral apposition rate (p = 0.0002), double-labeled surface (p = 0.0005), single-labeled surface (p = 0.006), bone formation rate (p = 0.0005), adjusted apposition rate (p = 0.0001), longer mineralization lag time (p = 0.012), and greater activation frequency (p = 0.003). Prolonged mineralization lag time in the radius was associated with thin osteoid seams and low adjusted apposition rates and was therefore attributable to a low level of osteoblast activity rather than to osteomalacia. We conclude that bone from the distal radius was structurally inferior to and had lower turnover than the iliac crest bone. We suggest that where a graft has to provide immediate structural integrity, the iliac crest is the preferred donor site. However, where bone graft is to be compacted into a small cavitary defect, distal radial bone may be an adequate alternative. A clinical study is needed to confirm this assumption.

Adult↗