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M C Yoder

Publications and source records attributed to M C Yoder.

At least 37 records · Page 2Linked to original sources
PubMed1996

Isolation of primitive human bone marrow hematopoietic progenitor cells using Hoechst 33342 and Rhodamine 123.

In addition to possessing multilineage differentiation and self-renewal capabilities, pluripotent hematopoietic stem cells are believed to be mitotically quiescent and metabolically inactive. Fractions of human bone marrow (BM) CD34+ cells can be further enriched for primitive hematopoietic progenitor cells (HPC) by using a number of cell-surface markers. All of these fractions, however, contain cells that are still heterogeneous as far as their metabolic and mitotic activities are concerned. We therefore used Hoechst 33342 (Hst) to identify quiescent cells and Rhodamine 123 (Rh123) to identify metabolically inactive cells. CD34+HstdimRh123dim (CD34+d/d) and CD34+HstbrightRh123bright (CD34+b/b) cells were isolated by flow cytometry to examine the hematopoietic functions of mitotically and metabolically homogeneous progenitors. Cell-cycle status, progenitor cell content, maintenance of in vitro hematopoiesis, and long-term hematopoietic culture-initiating cell (LTHC-IC) content of CD34+d/d and CD34+b/b cells were compared with CD34+HLA-DR- cells, a well-defined phenotype of primitive HPC. Whereas 99.2 +/- 0.5% of freshly isolated CD34+d/d cells were in G0/G1 phase of the cell cycle, only 74.4 +/- 11.5% of CD34+b/b and 75.6 +/- 1.1% of CD34+HLA-DR- cells were in G0/G1. The number of multipotential progenitors (colony-forming units-granulocyte/erythroid/ macrophage/megakaryocyte [CFU-GEMM]) detected in CD34+d/d cells was twice that observed in CD34+HLA-DR- cells and eight times that in CD34+b/b cells. In stromal cell-free long-term cultures maintained for 10 weeks, production of assayable progenitors in cultures initiated with CD34+d/d cells exceeded that detected in CD34+HLA-DR- cultures by more than three-fold. Only in CD34+d/d cultures were high proliferative potential colony-forming cell (HPP-CFC)-derived colonies detected over a period of 6 weeks. Limiting dilution analysis revealed that the frequency of LTHC-IC was highest among CD34+d/d cells (7.2 +/- 3.3%), followed by a frequency of 4.5 +/- 4.8% for CD34+HLA-DR- cells and 2.2 +/- 3.5% for CD34+b/b cells. The primitive nature of HPC identified by CD34, Hst, and Rh123 was confirmed by the ability of as few as 200 murine marrow cells isolated by this technique to radioprotect and fully reconstitute lethally irradiated recipients. These results indicate that Hst and Rh123 staining can be used in combination with CD34 immunofluorescence to isolate a quiescent subpopulation of human primitive hematopoietic progenitor cells. Cells isolated by this technique appear to have functional properties associated with stem cells, suggesting that they may be ideal candidates for studies requiring primitive HPC, such as ex vivo expansion and somatic gene therapy.

Adult↗
PubMed1996

A novel method of myeloablation to enhance engraftment of adult bone marrow cells in newborn mice.

This report describes the successful development of a transplantation model in which we engrafted adult murine bone marrow hematopoietic cells in congenic day-old murine pups. Newborn animals conditioned with high doses (> or = 7.0 Gy) of total-body irradiation (TBI) demonstrated severe growth retardation and untoward effects on the developing central nervous system. Newborn pups conditioned with a sublethal dose (5.0 Gy) of TBI, however, achieved normal growth and development up to 6 months posttransplantation, and donor type hematopoietic cell reconstitution exceeded 50% in these animals. A second conditioning regimen, comprising one or two doses of busulfan (15 mg/kg) administered intrapartum, resulted in significant myelosuppression in untransplanted newborn pups. This second regimen was associated, however, with engraftment and full multilineage reconstitution of the conditioned newborn recipient animals with adult bone marrow cells, and the engrafted pups grew and developed without apparent defect. A third conditioning regimen combining a single dose of busulfan with sublethal TBI also permitted engraftment and full multilineage reconstitution of the recipient animals. Thus, successful transplantation of hematopoietic cells into newborn recipient mice may be achieved without significant morbidity if a specific conditioning regimen is employed.

Animals↗
PubMed1995

Parvovirus B19 promoter at map unit 6 confers autonomous replication competence and erythroid specificity to adeno-associated virus 2 in primary human hematopoietic progenitor cells.

The pathogenic human parvovirus B19 is an autonomously replicating virus with a remarkable tropism for human erythroid progenitor cells. Although the target cell specificity for B19 infection has been suggested to be mediated by the erythrocyte P-antigen receptor (globoside), a number of nonerythroid cells that express this receptor are nonpermissive for B19 replication. To directly test the role of expression from the B19 promoter at map unit 6 (B19p6) in the erythroid cell specificity of B19, we constructed a recombinant adeno-associated virus 2 (AAV), in which the authentic AAV promoter at map unit 5 (AAVp5) was replaced by the B19p6 promoter. Although the wild-type (wt) AAV requires a helper virus for its optimal replication, we hypothesized that inserting the B19p6 promoter in a recombinant AAV would permit autonomous viral replication, but only in erythroid progenitor cells. In this report, we provide evidence that the B19p6 promoter is necessary and sufficient to impart autonomous replication competence and erythroid specificity to AAV in primary human hematopoietic progenitor cells. Thus, expression from the B19p6 promoter plays an important role in post-P-antigen receptor erythroid-cell specificity of parvovirus B19. The AAV-B19 hybrid vector system may also prove to be useful in potential gene therapy of human hemoglobinopathies.

Dependovirus↗
PubMed1995

Murine embryonic yolk sac cells promote in vitro proliferation of bone marrow high proliferative potential colony-forming cells.

To examine the influence of the hematopoietic microenvironment on hematopoietic cell proliferation and differentiation during the yolk sac phase of hematopoiesis, we have recently established cell lines from embryonic yolk sac visceral endoderm (YSE) and mesoderm (YSM). In the present experiments, we compared in vitro growth of adult murine bone marrow high proliferative potential colony-forming cells (HPP-CFC) in coculture with YSE- and YSM-derived or adult bone marrow stromal cell lines. Whereas both yolk sac-derived and adult stromal cell lines supported the proliferation of HPP-CFC during coculture, YSE- and YSM-derived cells stimulated a significant increase in total HPP-CFC compared with adult bone marrow stromal cell lines. Conditioned media from both YSE- and YSM-derived cell lines also stimulated the growth of HPP-CFC in vitro, but only in combination with exogenous recombinant hematopoietic growth factors. Although multiple hematopoietic growth factor mRNAs were detected in the yolk sac-derived cells by polymerase chain reaction, only macrophage colony-stimulating factor (M-CSF) activity was detected in conditioned media using an enzyme-linked immunosorbent assay. A neutralizing polyclonal antibody against M-CSF did not diminish the YSE- or YSM-derived cell line conditioned media promotion of HPP-CFC colony formation. These results suggest that murine yolk sac-derived cell lines produce a novel soluble factor(s) that recruits primitive bone marrow hematopoietic cells to grow in vitro in response to a combination of hematopoietic growth factors.

Animals↗
PubMed1995

Myeloproliferative sarcoma virus directed expression of beta-galactosidase following retroviral transduction of murine hematopoietic cells.

The introduction of genetic sequences into hematopoietic stem cells (HSC) has allowed study of HSC proliferation in vivo by proviral-sequence molecular analysis in the DNA of progeny. Analysis of HSC proliferation could be enhanced by development of a retroviral vector that encodes a reporter gene that allows sensitive detection of transduced cells. We developed a recombinant retrovirus vector encoding the reporter gene lacZ under the transcriptional control of the myeloproliferative sarcoma virus long-terminal repeat (LTR). Bone marrow cells from C3H mice were co-cultured on retrovirus producer cell lines and cultured for growth of colony-forming unit granulocyte/macrophage (CFU-GM) and high proliferative potential colony-forming cells (HPP-CFC) in semisolid media or were transplanted into irradiated recipients. In other experiments, recombinant retrovirus was injected in vivo into the liver of developing fetal rat pups, and circulating hematopoietic cells of the postnatal rats were analyzed for evidence of proviral integration and expression of beta-galactosidase. Expression of lacZ was detected in both CFU-GM and HPP-CFC that were cultured immediately following in vitro infection of mouse bone marrow. Beta-galactosidase activity from the retrovirus was also detected in both marrow cells isolated from reconstituted mice 22 weeks following transplantation as well as in blood cells of postnatal rats transduced in utero with the recombinant retrovirus. This strategy may be especially useful for characterizing proliferation of transduced populations of hematopoietic cells and in the development of protocols for somatic gene therapy.

Animals↗
PubMed1995

Matrix molecule interactions with hematopoietic stem cells.

We have reviewed some aspects of the production, distribution, and organization of fibronectin in the bone marrow ECM and discussed HSC-fibronectin interactions. Many questions remain. Which isoforms of fibronectin are produced in the bone marrow during ontogeny, normal hematopoiesis, and pathophysiologic challenges to the marrow microenvironment? Do HSCs interact with ED-A- and ED-B-containing fibronectin isoforms the same way they interact with plasma fibronectin? Are different fibronectin isoforms selectively expressed in different regions of the bone marrow, in keeping with the spatial organization of HSC and hematopoietic progenitor cell compartments? Addressing these questions may give us a better understanding of the role of fibronectin in HSC localization, proliferation, and differentiation. Considerable information regarding the synthesis and secretion of other ECM molecules by adherent stromal cells has been derived from in vitro analysis of LTBMCs [3]. As with fibronectin, much remains to be learned of the precise distribution and composition of bone marrow ECM molecules during in vivo development; how in vivo bone marrow ECM secretion, turnover, and remodeling are regulated during normal and pathologic hematopoietic states; and the nature and importance of in vivo cellular interactions that occur between PHSC and individual constituents of the bone marrow ECM.

Animals↗
PubMed1994

Murine yolk sac endoderm- and mesoderm-derived cell lines support in vitro growth and differentiation of hematopoietic cells.

The mechanisms involved in the induction of yolk sac mesoderm into blood islands and the role of visceral endoderm and mesoderm cells in regulating the restricted differentiation and proliferation of hematopoietic cells in the yolk sac remain largely unexplored. To better define the role of murine yolk sac microenvironment cells in supporting hematopoiesis, we established cell lines from day-9.5 gestation murine yolk sac visceral endoderm and mesoderm layers using a recombinant retrovirus vector containing Simian virus 40 large T-antigen cDNA. Obtained immortalized cell lines expressed morphologic and biosynthetic features characteristic of endoderm and mesoderm cells from freshly isolated yolk sacs. Similar to the differentiation of blood island hematopoietic cells in situ, differentiation of hematopoietic progenitor cells in vitro into neutrophils was restricted and macrophage production increased when bone marrow (BM) progenitor cells were cultured in direct contact with immortalized yolk sac cell lines as compared with culture on adult BM stromal cell lines. Yolk sac-derived cell lines also significantly stimulated the proliferation of hematopoietic progenitor cells compared with the adult BM stromal cell lines. Thus, yolk sac endoderm- and mesoderm-derived cells, expressing many features of normal yolk sac cells, alter the growth and differentiation of hematopoietic progenitor cells. These cells will prove useful in examining the cellular interactions between yolk sac endoderm and mesoderm involved in early hematopoietic stem cell proliferation and differentiation.

Animals↗
PubMed1993

High proliferative potential colony-forming cell heterogeneity identified using counterflow centrifugal elutriation.

Murine high proliferative potential colony-forming cells (HPP-CFC) are known to be heterogenous with respect to proliferative capacity and in vitro responsiveness to hematopoietic growth factors. We have separated HPP-CFC into several subpopulations using counterflow centrifugal elutriation. Although HPP-CFC were identified in all of the elutriated fractions of both C3H/HeJ and C57BI/6J bone marrow cells, the distribution of HPP-CFC as well as of colony-forming units-granulocyte-macrophage (CFU-GM) in each fraction differed between these two strains of inbred mice. Six subsets of HPP-CFC were resolved that differed in growth factor responsiveness. A low-density HPP-CFC subpopulation was isolated that was distinct from day-12 spleen colony-forming units (CFU-S12), CFU-GM, and bone marrow stromal cells. This unique subpopulation of HPP-CFC is rate (3% to 9% of total HPP-CFC), appears to be lymphocyte-like in morphology, and behaves the most primitive of the HPP-CFC subsets by requiring multiple hematopoietic growth factors for optimal in vitro cloning. Further characterization of this subpopulation of HPP-CFC will determine the position of these cells in the HPP-CFC heirarchy.

Animals↗
PubMed1993

In vitro comparison of multinucleated giant cell formation from human umbilical cord and adult peripheral blood mononuclear phagocytes.

The fetus and newborn infant are highly susceptible to infection by pathogens that are capable of intracellular survival. The invasion of these microbes usually stimulates a granulomatous host defense response in the fetus or neonate. Multinucleated giant cells (MGC) are the predominant cells composing the granuloma and represent the terminally differentiated state of activated macrophages. Because macrophages derived from human umbilical cord blood monocytes demonstrate some deficiencies in activated functions, we tested the ability of these cells to form MGC in vitro. Mononuclear cells from umbilical cord blood and adult peripheral blood were isolated and cultured for 7, 14, or 21 d before stimulation with phorbol myristate acetate (PMA), an agent known to stimulate MGC from mononuclear phagocytes in vitro. Spontaneous MGC formation occurred in both cord and adult blood mononuclear cell cultures by d 7 of incubation, although significantly fewer MGC formed in the cord blood cultures. PMA treatment of adult blood mononuclear cells resulted in a significant increase in MGC formation after 7, 14, or 21 d of culture, but PMA did not significantly increase MGC formation in cord blood cultures until 14 or 21 d of culture. Pretreatment of cord and adult blood mononuclear cells with 1,25-dihydroxyvitamin D3 inhibited PMA-induced MGC formation. However, when a purified population of cord blood, monocyte-derived macrophages were pretreated with 1,25-dihydroxyvitamin D3, PMA significantly increased MGC formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

The use of bronchotomy and retrograde dilatation to repair acquired obliterative bronchial obstruction.

A case is presented of acquired obliterative mainstem bronchial obstruction with total ipsilateral lung atelectasis and contralateral lung hyperexpansion. The condition failed to improve after a suitable trial of positive airway pressure and medical management. Penetration of the obstructing lesion bia bronchotomy and a distal retrograde approach successfully opened the airway and the patient has been symptom-free for more than 9 months. This unique approach may be useful in other selected patients with similar acquired lesions.

Airway Obstruction↗
PubMed1992

Pulmonary hypoplasia and persistent pulmonary hypertension: favorable clinical response to high-frequency jet ventilation.

Pulmonary hypoplasia in the neonate is frequently fatal. This article reports two neonates with a clinical diagnosis of pulmonary hypoplasia complicated by persistent pulmonary hypertension (PPHN). Though both infants were progressively worsening while receiving conventional mechanical ventilatory support, they survived when treated with high-frequency jet ventilation.

High-Frequency Jet Ventilation↗
PubMed1991

Effect of dexamethasone on pulmonary inflammation and pulmonary function of ventilator-dependent infants with bronchopulmonary dysplasia.

Seventeen ventilator-dependent premature infants with bronchopulmonary dysplasia (BPD) were enrolled in a double-blind, placebo-controlled study to determine the effects of 3 days of intravenously administered dexamethasone (0.5 mg/kg/day) on pulmonary function, pulmonary inflammation, and the requirement for respiratory support (FIO2, ventilator peak pressure [PP], and respiratory rate [RR]). Assessment of pulmonary function included measurement of FVC, flow at 25% vital capacity (V25), and static compliance of the respiratory system (Crs), whereas pulmonary inflammation was assessed by the neutrophil count, ratio of elastase/2 x alpha-1-antitrypsin, and the concentrations of albumin and fibronectin in the tracheobronchial lavage (TBL) fluid. After 3 days of placebo treatment there were no significant changes in any of the measured parameters. In contrast, the dexamethasone-treated group demonstrated a significant decrease in respiratory support (FIO2: 50 versus 36%; PP: 21 versus 16 cm H2O; RR: 22 versus 14 breaths/min) and improved pulmonary function (Crs: 0.63 versus 0.85 ml/cm H2O/kg; V25: 23 versus 68 ml/s/kg). In addition, pulmonary inflammation was suppressed in the dexamethasone-treated group (neutrophils: 23 versus 11 x 10(4)/mg albumin: elastase/2 x alpha-1-antitrypsin: 0.24 versus 0.10; albumin: 7.1 versus 3.5 mg/dl; fibronectin: 33 versus 17 micrograms/mg albumin). We conclude that short-term treatment with dexamethasone improves pulmonary function and suppresses pulmonary inflammation as well as decreasing the respiratory support required by ventilator-dependent premature infants with BPD.

Albumins↗
PubMed1991

Therapeutic administration of fibronectin: current uses and potential applications.

Fibronectins are a class of multifunctional glycoproteins that exist in soluble and insoluble forms. These glycoproteins are found in nearly all body fluids and in tissue extracellular matrices. Alterations in the normal synthesis, release, and distribution of fibronectins are characteristic features of certain human pathophysiologic conditions. The therapeutic administration of plasma fibronectin to human patients with defects in corneal wound healing and critically ill adult patients with multisystem organ failure appears clinically beneficial, although confirmation is needed from additional trials in progress. In vitro data suggest a role for fibronectin in enhancing (directly and indirectly) the function of phagocytes isolated from the blood of newborn infants. Although as yet untested, it is possible that fibronectin administration to the immunologically immature human neonate may improve host defenses and reduce the risk of nosocomial infection. Additional research is needed to define the factors that regulate the synthesis, isoform expression, and clearance of endogenous fibronectins during normal fetal and neonatal development. Continued research to define the role of endogenous fibronectins in augmenting the inflammatory response of the neonatal host is also required before rational immunotherapeutic interventions can be initiated.

Bacterial Infections↗
PubMed1990

Rapid analysis of lymphocyte subsets in cord blood.

Several investigators have enumerated cellular populations in neonatal cord blood with variable results. In this study, the authors established reference ranges for lymphocyte subsets in cord blood from healthy newborns using a whole blood lysis technique on the Coulter Immunoprep Epics Leukocyte Preparation System (Coulter Immunology, Hialeah, FL). All analyses were performed on a flow cytometer by gating on forward angle versus 90 degrees light scatter. Lymphocytes demonstrated all surface markers examined, including T4, T8, T3, T11, B1, NKH-1, I3, and 4B4; 2H4 suppressor inducer lymphocytes were prominent in neonatal blood. The authors think this standardized system may be suitable for use in neonatal and pediatric patients because it quickly processes small aliquots of whole blood with minimal sample manipulation.

Fetal Blood↗
PubMed1990

Pulmonary microcirculatory kinetics of neutrophils deficient in leukocyte adhesion-promoting glycoproteins.

The mechanism that causes neutrophils to sequester in the pulmonary circulation is unknown. Because the CD11/CD18 glycoprotein family on the surface membrane of neutrophils participates in many adhesive interactions with the endothelium, we investigated the role of these proteins in the intravascular sequestration of pulmonary neutrophils. Neutrophils were isolated from normal dogs and from the only living dog known to have leukocyte adhesion deficiency disease, an inherited deficiency of the CD11/CD18 adhesion family. The neutrophils were labeled with fluorescein dye, injected into normal recipient dogs, and their passage through the pulmonary microcirculation was recorded by in vivo videofluorescence microscopy through a transparent thoracic window. Transit times for normal and deficient neutrophils were similar over a wide range of hemo-dynamic conditions. Activation by zymosan-activated plasma, which increases the surface membrane expression of CD11/CD18, prolonged the transit of normal neutrophils but did not alter the transit time of the deficient neutrophils. These results indicate that neutrophil CD11/CD18 adhesion-promoting glycoproteins are not involved in the normal pulmonary sequestration of neutrophils but have a significant role in the arrest of activated neutrophils in the pulmonary capillaries.

Animals↗
PubMed1989

Delayed presentation of a right-sided diaphragmatic hernia and group B streptococcal sepsis. Two case reports and a review of the literature.

Group B streptococcal sepsis was associated with delayed presentation of an unsuspected right-sided diaphragmatic hernia in two neonates. These unusual clinical observations and a review of 24 similar cases from the literature form the basis of this report. Infants present with respiratory distress during the first few hours of life and have group B streptococcal sepsis confirmed by results of blood cultures. The right side of the diaphragm appears normal on the initial chest roentgenogram in the majority of cases. After initial improvement with antibiotic therapy and ventilatory support, sudden deterioration of respiratory status may occur. Subsequent chest roentgenograms often demonstrate herniated viscera in half of the cases, while ultrasound examination, isotopic liver scan, and peritoneography are useful in achieving a diagnosis in the other cases. If recognized, survival is 100% following hernia repair. Persistent respiratory symptoms in a neonate who is recovering from group B streptococcal sepsis should prompt a careful evaluation of the right side of the diaphragm for the presence of an unsuspected posterolateral hernia.

Hernia, Diaphragmatic↗