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P Quesenberry

Publications and source records attributed to P Quesenberry.

At least 19 recordsLinked to original sources
PubMed2005

In vivo haematopoietic potential of human neural stem cells.

The fetal sheep model was used to compare the in vivo haematopoietic potential of human neural stem cells (NSC) versus bone marrow (BM)-derived haematopoietic stem cells (HSC). To this end, sheep were transplanted with either 8 x 10(5) NSC (n = 11) or HSC, CD34(+)Lin(-) (n = 5), and subsequently analysed for haematopoietic chimaerism. While HSC-transplanted sheep displayed robust donor-derived haematopoiesis starting at less than 2 months post-transplant, NSC recipients exhibited haematopoietic engraftment at much later time points. Nevertheless, chimaerism persisted in both groups throughout the course of this study. Transplantation of secondary recipients with human CD45(+)/HLA-DR(+) cells from the BM of NSC primary recipients at 14 and 16 months post-transplant demonstrated that long-term engrafting HSC were present in these animals. At 6 months post-transplant, both NSC- and HSC-transplanted sheep were mobilised with granulocyte colony-stimulating factor. In contrast to HSC-transplanted animals, levels of human blood cells in peripheral blood of NSC-transplanted sheep remained low throughout mobilisation. Our results show that, although human NSC were able to give rise to multilineage haematopoiesis in our model, the levels, timing of blood cell production and the ability to respond to cytokine mobilisation were different, suggesting that human NSCs latent haematopoietic potential is inherently different from that of true HSC.

Animals↗
PubMed2005

The marrow cell continuum: stochastic determinism.

Traditional models of hematopoiesis have been hierarchical in nature. Over the past 10 years, we have developed data indicating that hematopoiesis is regulated in a continuum with deterministic and stochastic components. We have shown that the most primitive stem cells, as represented by lineage negative rhodamine(low) Hoechst(low) murine marrow cells are continuously or intermittently cycling as determined by in vivo BrdU labeling. When marrow stem cells are induced to transit cell cycle by in vitro exposure to cytokines, either IL-3, IL-6, IL-11, and steel factor or thrombopoietin, FLT3 ligand, and steel factor, they progress through cycle in a highly synchronized fashion. We have determined that when the stem cells progress through a cytokine stimulated cell cycle the homing, engraftment, adhesion protein, global gene expression, and hematopoietic differentiation phenotypes all change in a reversible fashion. This has led to the continuum model, in which, with cycle transit, chromatin is continually changing altering open transcription areas and providing a continually changing landscape of transcriptional opportunity. More recently, we have extended the changing differentiation profiles to differentiation into lung cells and found that non-hematopoietic differentiation also shows cycle related reversibly modulation. These observations all together support a continuum model of stem cell regulation in which the phenotype of the marrow stem cells is continually and reversibly changing over time.

Animals↗
PubMed2003

Marrow stem cell potential within a continuum.

On the basis of our studies of the fluctuation of the hematopoietic stem cell phenotype with cell cycle trnsit, we hypothesize that the ability of marrow stem cells to convert to nonhematopoietic cells will also vary at different points in the cell cycle. The new biology of stem cells has an impact on many fields including developmental biology and stem cell biology and the clinical potential is enormous.

Animals↗
PubMed2000

Effect of ex vivo cytokine treatment on human cord blood engraftment in NOD-scid mice.

Umbilical cord blood transplantation is considered an alternative to traditional bone marrow transplantation for patients who do not have matched sibling donors. In this study, we examined the effects of ex vivo treatment of human cord blood cells with cytokine mixtures and assessed the ability of treated cells to engraft in NOD-scid mice. We incubated the cord blood with a four-factor cytokine mixture of interleukin (IL)-3, IL-6, IL-11 and stem cell factor, or with a two-factor cytokine mixture of thrombopoietin and flt-3. Incubation of cord blood for 48 h with either cytokine mixture did not affect progenitor cell number or proliferative potential as measured by the high proliferative potential (HPP) assay. Cytokine-treated cord blood injected into irradiated NOD-scid mice resulted in multilineage human engraftment. Overall, incubation with cytokines resulted in variable levels of engraftment with different cord blood samples. Incubation of cord blood with the four-factor cytokine mixture resulted in increased survival of irradiated NOD-scid recipients. These results demonstrate that short-term ex vivo treatment of human progenitor cells gives variable results on in vivo multipotential capabilities.

Animals↗
PubMed1999

Osteoblast-specific gene expression after transplantation of marrow cells: implications for skeletal gene therapy.

Somatic gene therapies require targeted transfer of the therapeutic gene(s) into stem cells that proliferate and then differentiate and express the gene in a tissue-restricted manner. We have developed an approach for gene therapy using marrow cells that takes advantage of the osteoblast specificity of the osteocalcin promoter to confine expression of chimeric genes to bone. Adherent marrow cells, carrying a reporter gene [chloramphenicol acetyltransferase (CAT)] under the control of a 1.7-kilobase rat osteocalcin gene promoter, were expanded ex vivo. After transplantation by intravenous infusion, engrafted donor cells in recipient mice were detected by the presence of the transgene in a broad spectrum of tissues. However, expression of the transgene was restricted to osteoblasts and osteocytes, as established by biochemical analysis of CAT activity and immunohistochemical analysis of CAT expression at the single cell level. Our data indicate that donor cells achieved long-term engraftment in various tissues of the recipients and that the CAT gene under control of the osteocalcin promoter is expressed specifically in bone. Thus, transplantation of multipotential marrow cells containing the osteocalcin promoter-controlled transgene provides an efficacious approach to deliver therapeutic gene expression to osteoblasts for treatment of bone disorders or tumor metastasis to the skeleton.

Animals↗
PubMed1999

Safety and cost of hyperhydration for the prevention of hemorrhagic cystitis in bone marrow transplant recipients.

Hemorrhagic cystitis is a major cause of morbidity after bone marrow transplantation. Traditional methods of prevention have included mesna (2-mercaptoethane sodium sulfonate) and bladder irrigation. We report the use of hyperhydration as an alternative to these prophylactic measures. One hundred consecutive patients who underwent autologous or allogeneic bone marrow transplantation received high dose cyclophosphamide with hyperhydration using 5% dextrose normal saline at the rate of 250 ml/h and furosemide to maintain a urine output of >150 ml/h. Seventy-one of these patients also received high dose cyclophosphamide as mobilization chemotherapy. There were no episodes of hemorrhagic cystitis following mobilization chemotherapy. The incidence of hemorrhagic cystitis after transplant conditioning was 7% with 2 patients developing clinically significant hemorrhagic cystitis; one was a severe episode. The cost of hyperhydration was US$ 20 per course as opposed to US$ 1,500 per course for mesna, based on acquisition costs at our institution. We conclude that hyperhydration is a safe, inexpensive means of preventing hemorrhagic cystitis associated with high dose cyclophosphamide in bone marrow transplant recipients.

Adult↗
PubMed1998

Centrosome defects and genetic instability in malignant tumors.

Genetic instability is a common feature of many human cancers. This condition is frequently characterized by an abnormal number of chromosomes, although little is known about the mechanism that generates this altered genetic state. One possibility is that chromosomes are missegregated during mitosis due to the assembly of dysfunctional mitotic spindles. Because centrosomes are involved in spindle assembly, they could contribute to chromosome missegregation through the organization of aberrant spindles. As an initial test of this idea, we examined malignant tumors for centrosome abnormalities using antibodies to the centrosome protein pericentrin. We found that centrosomes in nearly all tumors and tumor-derived cell lines were atypical in shape, size, and composition and were often present in multiple copies. In addition, virtually all pericentrin-staining structures in tumor cells nucleated microtubules, and they participated in formation of disorganized mitotic spindles, upon which chromosomes were missegregated. All tumor cell lines had both centrosome defects and abnormal chromosome numbers, whereas neither was observed in nontumor cells. These results indicate that centrosome defects are a common feature of malignant tumors and suggest that they may contribute to genetic instability in cancer.

Antigens↗
PubMed1998

Expression and function of colony-stimulating factors and their receptors in human prostate carcinoma cell lines.

BACKGROUND: The predeliction for prostate carcinoma cells to metastasize to bone suggests the hypothesis that bone and/or bone marrow-derived factors may promote prostate carcinoma cell growth or survival, or serve as chemoattractants for these cells. METHODS: We screened three prostate carcinoma cell lines, DU-145, PC-3, and LNCaP, for the expression of several hematopoiesis-associated colony-stimulating factors (CSFs) and their receptors using RT-PCR (reverse transcriptase-polymerase chain reaction) and immunohistochemical methods, and examined their functional effects. RESULTS: All of these cell lines express granulocyte-macrophage colony-stimulating factor (GM-CSF) and macrophage colony-stimulating factor (M-CSF), and the DU-145 and PC-3 lines express stem-cell factor (SCF), as determined by RT-PCR and ELISA. Each of these cell lines expresses the receptors for SCF, GM-CSF, M-CSF, and granulocyte colony-stimulating factor (G-CSF). M-CSF enhanced the soft-agar clonogenicity of PC-3 and DU-145 cells, and GM-CSF stimulated all three cell lines. SCF stimulated the clonogenic growth of DU-145 cells. G-CSF marginally abrogated the induction of cell death in the PC-3 and LNCaP cell lines under serum-free conditions. GM-CSF and M-CSF stimulated modest chemotaxis of PC-3, DU-145, and LNCaP cells (most prominently in PC-3 cells). CONCLUSIONS: These data suggest that 1) CSFs may be part of a network of paracrine and autocrine loops that modulate prostate carcinoma cell activity, and 2) the growth-stimulatory, survival-enhancing, and/or chemotactic actions of bone marrow-derived CSFs on prostate carcinoma cells may explain in part why bone is a preferential site of prostatic carcinoma metastases.

Base Sequence↗
PubMed1998

Coverage of bone marrow transplant patients: a survey of American and Canadian institutions.

Personnel involved in supportive care of bone marrow transplant (BMT) patients include fellows (F), medical house-staff (HS), nurse practitioners (NP), physician assistants (PA), and moonlighting physicians (MP). We have obtained surveys from 108 American and Canadian transplant centers on the composition of inpatient support teams. Eighty-seven percent of institutions responding to the survey were university-based programs. Eighty-eight percent of the centers performed both allogeneic and autologous transplants, and 60% performed unrelated donor grafts. The mean number of transplants performed annually at each center was 101 (range 4-515). For daytime coverage, the percent of programs involving F, HS, NP, PA, or MP was 57, 50, 35, 25, and 0%, respectively, and for nighttime coverage, the composition was 50, 56, 7, 6, and 13%, respectively. Medical HS were incorporated into the care of BMT patients at some level in 93% of the programs. Involvement by HS included full 24-hour coverage (44%), full nighttime coverage (8%), stat coverage (18%), and code blue only coverage (21%). HS involvement was similar in small and large transplant programs. HS were more involved in university-based programs. Programs on the East Coast had more HS involvement, with 54% of the programs reporting full 24-hour coverage by HS compared with 32% of the programs in the Pacific region. Coverage of transplant patients varies throughout the country, and nonphysician providers are often used. HS are more active in university-based programs, and their role is similar in both large and small programs.

Bone Marrow Transplantation↗
PubMed1998

Repetitive bone marrow transplantation in nonmyeloablated recipients.

Transplantation of 200 million male BALB/c marrow cells into normal nonmyeloablated female BALB/c hosts results in relatively high levels of engraftment, whether the cells are infused repetitively over time or in a single infusion. These high engraftment rates suggested that repetitive injections of high levels of male BALB/c cells might be able to totally replace host marrow. Accordingly, we transplanted 40x10(6) male BALB/c bone marrow cells into female BALB/c recipients over a 7-week period for a total of 20 injections (800x10[6] marrow cells). Engraftment in this experimental group was compared to that seen when female recipients received 2x10(6) male marrow cells or phosphate-buffered saline (PBS) over the same injection schedule. Engraftment was quantitated at 5 and 7 weeks after the final infusion by detection of male-specific sequences in female host marrow, spleen, and thymus by Southern blot analysis using a Y-specific cDNA probe. Male DNA levels were quantitated with a Molecular Dynamics phosphorimager. Engraftment of male cells into female marrow at 5 and 7 weeks posttransplantation ranged from 19 to 88%, whereas that in spleen and thymus ranged between 30 and 100% and 28 and 50%, respectively. The mean percent engraftments for marrow, spleen, and thymus were 41, 69, and 39%, respectively. Mean percent engraftments for 2x10(6) cell infusions at 5 and 7 weeks for marrow, spleen, and thymus were 4, 6, and 4%, respectively. Marrow and spleen cellularity and total high proliferative potential colony-forming cell numbers were determined in PBS- and cell-injected mice. No significant differences between these groups were observed. For marrow engraftment, 20 injections of 40x10(6) cells was not more effective than five, but donor DNA in thymus and spleen was increased with 20 injections. Primitive progenitor cell levels and marrow cellularity do not increase in mice injected with large numbers of marrow cells, suggesting that host marrow cells are replaced rather than augmented by infused donor cells.

Animals↗
PubMed1998

Chiaroscuro hematopoietic stem cell.

These observations suggest several immediate clinical strategies. In gene therapy, approaches could be targeted to obtain cycling of hematopoietic stem cells and gene-carrying retrovirus vector integration followed by engraftment at an appropriate time interval which favors engraftment. The same type of approach can be utilized for stem cell expansion approaches. Alternatively marrow or peripheral stem cell engraftment can be obtained with minimal to no toxicity in allochimeric strategies in such diseases as sickle cell anemia or thalassemia. A similar approach could be useful in obtaining cell engraftment with minimal toxicity in therapies employing cellular immune (T-cell and NK-cell) attack against cancer. These areas of clinical application are outline in Table 3.

Animals↗
PubMed1998

Guidelines.

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Clinical Competence↗
PubMed1993

Leukocytes synthesize angiotensinogen.

To determine whether leukocytes express the angiotensinogen gene, we subjected circulating rat leukocytes and murine bone marrow cells to Northern blot analysis and hybridization with homologous angiotensinogen complementary DNA. Angiotensinogen messenger RNA sequences were detected in circulating adult rat leukocytes, in murine-irradiated and nonirradiated bone marrow stromal cells, and in an adherent stromal cell line (preadipocyte). Western blot analysis of rat leukocyte homogenate showed that rat leukocytes contain two main angiotensinogen isoforms with approximate molecular weights of 46.5 and 53.9 kd. Synthesis and release of angiotensinogen protein by rat leukocytes was confirmed by immunoprecipitation of radiolabeled angiotensinogen from cell lysate and media of rat leukocytes that were metabolically labeled with 35S-L-methionine. In addition, the angiotensinogen protein present in media of rat leukocytes was enzymatically cleaved by hog renin, resulting in generation of angiotensin I (305 +/- 47 pg angiotensin I per milliliter of media per hour). We conclude that circulating rat leukocytes express the angiotensinogen gene and synthesize and release angiotensinogen with the capability to generate angiotensin. Expression of angiotensinogen by leukocytes may provide a mobile angiotensin-generating system of potential importance in the regulation of local inflammatory responses, tissue injury (i.e., myocardial infarction), and arterial hypertension.

Angiotensin I↗
PubMed1991

Long-term marrow cultures: human and murine systems.

The intramedullary control of marrow cell production has been a difficult area to approach experimentally. The introduction by Dr. Dexter and colleagues of long-term stromal dependent culture systems for murine marrow and the adaptation of these systems to human marrow growth have allowed for in-vitro studies of stromal dependent hemopoiesis. Despite some controversy in this area, most studies appear to show that adherent murine or human stromal cells are capable of producing a relatively large number of hemopoietic growth factors including G-CSF, GM-CSF, CSF-1, IL-6 and, at least by PCR analysis, IL-3. Other work indicates that the most primitive hemopoietic cells which appear to be multifactor responsive adhere directly to these stromal cells presumably through mediation of various adherence proteins. An early acting, multilineage factor termed hemolymphopoietic growth factor-1 (HLGF-1) has been isolated from a murine stromal cell line and may be identical to the recently described ligand for the c-kit receptor. This may represent an important early survival/maintenance factor for stem cells in this system. Studies on primitive stem cells, especially the high proliferative potential colony forming cell (HPP-CFC), indicate that they are responsive to varying combinations of growth factors and that with increasing numbers of growth factors, as studied in serum-free systems, decreasing concentrations of the factors may be biologically active. These observations altogether suggest that intramedullary hemopoiesis may be regulated by the positioning of early multifactor responsive stem cells via adherent proteins in juxtaposition to synergistically acting combinations of growth factors attached to stromal cell surfaces or the extracellular matrix.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Detection and characterization of a B cell stimulatory factor (BSF-TC) derived from a bone marrow stromal cell line.

Stromal cell lines derived from murine bone marrow support the growth of immature pre-B cells and produce cytokines that affect the growth and differentiation of other hematopoietic precursors. Conditioned medium (CM) from one such line (TC-1) stimulated marked proliferation of B cells previously activated by anti-Ig (anti-Ig blasts). Proliferation of anti-Ig blasts was not induced by purified cytokines known to be produced by TC-1 (CSF-1, GM-CSF, or G-CSF) or by IL-1, IL-2, IL-3, IL-4, IL-5, or IL-6. Furthermore, IL-2, IL-4, and IL-5, alone or in combination, failed to support proliferation or differentiation of anti-Ig blasts. TC-1 CM enhanced proliferation of B cells that were co-cultured with LPS, anti-Ig, or dextran sulfate; co-stimulation with anti-Ig was unaffected by the presence of monoclonal anti-IL-4. Proliferation of low, but not high, density B cells isolated from spleen was directly stimulated by TC-1 CM. These results suggest that bone marrow stromal cells produce a novel B cell stimulatory factor (BSF-TC) that induces proliferation of activated B cells.

Animals↗