ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 0173-0835
    Keywords: Carbohydrate-deficient transferrin ; Glycosylation ; Sialic acid ; Physical gel ; Sieving matrix ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: The heterogeneity associated with protein glycoforms has been a challenge to analytical chemists and the subject of structure-function studies for biochemists since their presence in biological systems had been confirmed some three decades ago. Initial investigations led to discoveries of synthetic and degradative pathways, and brief forays into functional determination of the “glyco” portion on the protein activity in glycoproteins. Only recently has it come to our understanding that variations from the “normal” glycosylation patterns might be indicative of pathological states. The presence of certain transferrin (Tf) glycoforms in human serum has been shown to correlate with certain clinical syndromes. Hence, the ability to separate and quantitatively measure the various forms of human Tf has become increasingly important. It this study, we demonstrate that a simple method utilizing a DB-17-coated capillary to slow endoosmotic flow and a sieving buffer containing hydroxyethyl cellulose allows for the resolution of sialoforms of transferrin. An analysis time of less than eight minutes allows for baseline resolution of the lower sialoforms of Tf, presenting a simple, rapid test for carbohydrate-deficient transferrin (CDT). We demonstrate the utility of this methodology for the facile diagnosis of carbohydrate-deficient glycoprotein syndrome, and postulate that it may allow for the detection of other carbohydrate-deficient protein-related disease states.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2007-11-16
    Description: Hematopoietic stem cells (HSCs) are used therapeutically in bone marrow/hematopoietic stem cell transplantation (BMT/HSCT) to correct hematolymphoid abnormalities. Upon intravenous transplantation, HSCs can home to specialized bone marrow niches, self-renew and differentiate and thus generate a new, complete hematolymphoid system. Unfortunately BMT has had limited applications, due to the risks associated with the toxic conditioning regimens, such as irradiation and chemotherapy, that are deemed necessary for HSC engraftment. Elimination of these toxic conditioning regimens could expand the potential applications of BMT to include many non-malignant hematologic disorders, a wide variety of autoimmune disorders such as diabetes and multiple sclerosis, as well as in the facilitation of organ transplantation. The exact function of these traditional myeloablative conditioning regimens is not clear. To elucidate the barriers of HSC engraftment, we transplanted 50–1000 purified HSCs (Ckit+Lin−Sca1+CD34+CD150−) into immunodeficient, Rag2−/− or Rag2−/−gc−/− recipient mice and show that HSC engraftment levels rarely exceed 0.5% following transplantation without toxic conditioning, indicating that the immune system is not the only barrier to engraftment. Additionally, we did not observe a significant increase in HSC engraftment when HSC doses of 〉250 cells were transplanted. Even when up to 18000 HSC were transplanted, we did not see a linear increase in HSC engraftment, indicating that the increased doses of HSCs transplant inefficiently. We believe this is due to the naturally low frequency of available HSC niches, which we postulate may result from the physiologic migration of HSCs into circulation. Conversely, separation of the graft into small fractions and the subsequent time-delayed transplantation of these doses did result in increased engraftment due to the natural physiologic creation of new available HSC niches. When 1800 HSC were transplanted daily for seven days, the engraftment was 6.1-fold higher than transplantation of 12800 HSC in a single bolus. Here, we provide evidence that, aside from immune barriers, donor HSC engraftment is restricted by occupancy of appropriate niches by host HSCs. Through elimination of host HSCs we are able to increase available HSC niches for engraftment. We have developed a novel system where HSCs can be eliminated by targeting C-kit, a cell surface antigen that is highly expressed on the surface of HSCs. Cultivation of HSCs with ACK2, a depleting antibody specific for c-kit, prevented stem-cell factor (SCF) dependent HSC proliferation in vitro and resulted in cell death. Administration of ACK2 to mice led to the rapid and transient removal of 〉98% of endogenous HSCs in vivo thus resulting in equal numbers of available niches for engraftment. Following ACK2 clearance from serum, transplantation of these animals with donor HSCs led to chimerism levels of up to 90%, representing a 180-fold increase as compared to unconditioned animals. This non-myeloablative conditioning regimen had few side effects, other than temporary loss of coat color. The HSCs in even untransplanted animals rapidly recovered and animals remained healthy and fertile. This work redefines the way we approach BMT/HSCT, and places great emphasis on the necessity to create available HSC niches prior to transplantation. Extrapolation of these methods to humans may enable efficient yet mild conditioning regimens for transplantation, thus expanding the potential applications of BMT/HSCT.
    Print ISSN: 0006-4971
    Electronic ISSN: 1528-0020
    Topics: Biology , Medicine
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2004-11-16
    Description: c-kit is expressed on hematopoetic stem and progenitor cell populations. ACK-2 is an anti-mouse c-Kit monoclonal antibody which has been shown (by Nishikawa et al) to antagonize the function of c-kit and deplete the bone marrow of treated mice. We wished to characterize the effect of the anti c-kit mAb ACK-2 on the peripheral blood cell counts and marrow hematopoetic stem cell and progenitor populations. We also tested the hypothesis that treatment with ACK-2 may serve as a novel means of non-myeloablative conditioning for hematopoeitic stem cell transplantation. METHODS: Adult C57 black mice were injected either intravenouslyl or intraperitonealy with 1mg of ACK2 mAb every other day on Day 0, Day 2 and Day 4. Peripheral blood cell counts, including white cell differentials were followed over time in recipient mice. Peripheral blood and bone marrow was analyzed at Day 7, and marrow was analyzed for fraction and proportions of hematopoetic stem cells (HSC), common myeloid progenitors (CMP), granulocyte macrophage progenitors (GMP) and macrophage erythrocyte progenitors (MEP). A subset of Ly5.1 mice which had received ACK2 mAb on Days 0,2 and 4 received a bone marrow transplant on Day 7 with 1 Million bone marrow cells from a Ly5.2 donor. Peripheral blood from transplanted recipient mice was analyzed three weeks post transplant for presence of Ly5.2 donor derived cell engraftment. RESULTS: Both intravenous and intraperitoneal administration of ACK-2 resulted in rapid development of anemia, neutropenia and thrombocytopenia. In mice treated with intravenous ACK-2 on Days 0,2,4, the WBC dropped from a mean (3 mice) of 12.12 at Day 0 in untreated controls, to 6.6 at Day 2 to 4.2 at Day 4, and to 2.56 at day 7, recovering to a WBC of 9.5 by Day 11. The mean neutrophil dropped rapidly from a control mean of 796 prior to treatment, to 180 at Day 2, to 32 on Day 4, 26 on Day 7, recovering to a mean of 320 by Day 11. Hemoglobin dropped from a pretreatment mean of 15.1 to 14.5, 13.2, 6.2 and 5.3 on Days 2,4,7,11 respectively. Platelet counts fell from 1107 pre ACK-2 to 763 at Day 7 and 220 and Day 11, recovering to 1226 by Day 16. Analysis of Day 7 peripheral blood revealed an decrease in Mac-1+ cells from 12.2 of circulating white cells in untreated controls to 3.1%, while the proportion of B220+ B cells increased from 49.7 to 72.7%. The fraction of circulating T cells decreased from 24.5% to 11.1% at Day 7. The bone marrow fraction of KTLS HSC decreased from.07% in controls to.003% in Day 7 treated mice. Marrow fraction CMP decreased from 12% in untreated to 4.7% in treated, wheras the GMP population dropped from 66 to 53%. In ACK-2 treated mice which received 1 Million Ly5.2 syngeneic bone marrow cells analyzed at Day 21 post transplant, there was no evidence of Ly5.2+ donor derived peripheral blood white cells, as compared to 80% Ly5.2 donor derived cells in control mice which had received 9 Gray of radiation for conditioning. CONCLUSIONS: The anti-kit Monocolonal antibody rapidly induces anemia, neutropenia and thrombocytopenia with decreases in the marrow HSC and other progenitor populations. ACK-2 does not appear to facilitate non-myelablative conditioning for a syngeneic graft when given alone.
    Print ISSN: 0006-4971
    Electronic ISSN: 1528-0020
    Topics: Biology , Medicine
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2008-11-16
    Description: Introduction: Identification and understanding of the cells and processes that can generate, sustain and influence the HSC niche and hematopoiesis are critical for the development of a more comprehensive knowledge of normal hematopoiesis, stem cell homing, trafficking, differentiation and hematopoietic pathology. Growth and renewal in many tissues are initiated by stem cells, supported by the microenvironment (niche) in which they reside. While recent work has begun to describe functional interactions between stem cells and their niches, little is known about the formation of stem cell niches. Methods & Results: We established a functional, in vivo assay (via implantation of cells under the renal capsule) to isolate the determinants of hematopoietic stem cell (HSC) niche formation and activity. Using this novel assay, we show that a population of progenitor cells (CD45−Tie2-aV+CD105+Thy1.1−; CD105+Thy1−) sorted from 15.5 dpc fetal limbs and transplanted under the adult mouse renal capsule recruit host-derived vasculatures in a VEGF dependent manner, produce donor-derived ectopic bones through endochondral ossification, and generate a marrow cavity populated by host-derived long term reconstituting HSC (LT-HSC). In contrast, CD45−Tie2-aV+CD105+Thy1a+ (CD105+Thy1+) progenitors form bone that does not contain a marrow cavity. While analyzing these and other sorted populations, we did not observe any instances where niche was present without bone, suggesting that skeletal progenitors are necessary for initiating an HSC niche but osteoblasts alone cannot initiate and support niche activity. Suppression of factors important for HSC maintenance, such as steel factor (SLF), in progenitor populations prior to transplant did not alter their ability to initiate and support an HSC niche. On the other hand, suppression of factors involved in endochondral ossification, such as osterix and VEGF, inhibited niche generation. Furthermore, CD105+Thy1− progenitor populations derived from regions of the fetal mandible or calvaria that do not undergo endochondral ossification form only bone without marrow in our assay. Conclusions: In addition to identifying the limb-derived skeletal progenitor capable of endochondral ossification involved and the basic mechanisms of HSC niche initiation, our study provides a functional framework by which future studies on HSC-niche interactions at the cellular level can be carried out.
    Print ISSN: 0006-4971
    Electronic ISSN: 1528-0020
    Topics: Biology , Medicine
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2005-11-16
    Description: Normal human T lymphocyte differentiation occurs within the thymus. We previously determined that human thymocyte precursors develop via a novel CD3-4+8- intermediate population, utilizing SCID-hu thymic grafts (Kraft, Weissman &Waller, JEM). We have recently worked to develop a more convenient and robust model of human hematopoiesis utilizing RAG2/Common gamma chain double knock out mice (RAG2 DKO) transplanted with hematopoietic stem and progenitor cells from adult human donors. Methods: Human peripheral blood derived CD34+ cells were obtained to 〉90% purity by magnetic bead positive selection following apheresis from healthy GCSF mobilized donors. 200,000-800,000 human CD34+ cells were injected intrahepatically into 0–2 day old RAG2/CG DKO pups following 2Gy x 2 of irradiation. At serial time points following intrahepatic transplantation, human CD45+ chimerism and donor derived phenotype was measured within the bone marrow, peripheral blood, spleen, liver, lymph node and thymus by flow cytometry. Thymuses were further analyzed utilizing antibodies to human CD3, CD4 and CD8. Results: Robust human thymopoeisis was observed in CD34+ transplanted mice. The degree of human engraftment increased with the number of CD34+ cells transplanted. Overall 〉70% of recipient mice successfully engrafted with 〉10% human CD45+ expression in analyzed tissues, with a mean of 63% of cells within the thymus being human derived. At earlier time points (4–6 weeks post transplant) the thymus of recipient mice were found to contain high fractions of immature CD45+ CD3-4-8- cells (making up 31–43% of human cells within the thymus) and the CD3-4+8- intermediate (22–30%) and CD4+8+ double positive (34–71%) populations with very rare mature CD3+4+8- or CD3+4-8+ T-cells (figure A). At later time points the fraction of immature CD3-4-8- and CD3-4+8- populations declined and increasing fractions of mature CD3+4+8- and CD3+4-8+ populations were identified (Figure B), in distributions similar to those found in normal human thymus. Conclusions: Human T-cells can differentiate within the mouse thymus derived from adult human CD34+ cells, and development appears to progress normally within a murine thymic microenvironment. The early developement of a CD3-4+8- intermediate suggests that T-cell development occurs via this population, unlike the CD3-4-8+ intermediate found in murine thymopoesis, suggesting that the pathway of human T-cell differentiation is intrinisic to the human thymocytes, and is independant of whether the thymic stroma is human (as found in SCID-hu) or murine (in Rag2 DKO). This robust model system enabling study of human thymopoesis utilizing hematopoietic stem cells from normal and diseased adults human donors may provide significant advantages for the study of human intrathymic T-cell differentiation and function in-vivo. Human thymocyte profile in the RAG2 DKO thymus A) 4 and B) 8 weeks following intrahepatic transplantation of human CD34+ cells. Right panels: CD3 profile of CD4+8− population reveals a CD3−4+8− population Human thymocyte profile in the RAG2 DKO thymus A) 4 and B) 8 weeks following intrahepatic transplantation of human CD34+ cells. Right panels: CD3 profile of CD4+8− population reveals a CD3−4+8− population
    Print ISSN: 0006-4971
    Electronic ISSN: 1528-0020
    Topics: Biology , Medicine
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2008-11-16
    Description: INTRODUCTION: Bone marrow (BM) contains a rich supply of adult stem and progenitor cells, including hematopoieitic and mesenchymal stem cells which are used in Bone Marrow Transplantation (BMT) and an increasing array of regenerative therapies. Traditional marrow harvest methods utilize percutaneous large bore needle aspiration, result in marrow highly diluted by peripheral blood, and are crude, tedious, labor intensive and expensive, usually requiring general anesthesia, and 〉100 serial small volume aspirates to obtain adequate cell numbers for BMT. BM is showing increasing long-term advantages over mobilized PBSC for many alloegeneic BMTs, in terms of less cGVHD and in some cases improved survival. Improved BM harvest methods are needed. A novel device, the “MarrowMiner” (MM), was developed for the minimally invasive harvest of BM to enable the rapid, convenient, outpatient harvest of large quantities of BM under local anesthesia for use in allogeneic and autologous BMT and cell therapies utilizing autologous marrow derived cells. The MarrowMiner utilizes a single marrow entry site into the anterior or posterior iliac, through which the flexible, powered, guidable FlexShaft catheter can access the majority of the marrow space and aspirate rich marrow. Extensive testing in human cadavers and porcine models demonstrated a 10X increase in stem cells activity/ml (by CFU) compared to that of traditional needle harvests. The MM recently received both FDA and CE Mark regulatory approved, and ‘First In Human’ trials were successfully completed under local anesthesia, demonstrating safety, efficacy and higher stem cell yields compared to traditional methods. METHODS: In an ongoing prospective study, 10 patients undergoing autologous marrow derived therapy for use in regenerative medicine, had marrow harvested from their anterior or posterior ileac by the MM under local anesthesia on one hip, with direct comparison to standard needle serial marrow aspirates on the patients opposite hip (up to 350 ml per side). Cell viability, counts, CD34+, T cell, and MSC populations were assessed by flow cytometry. RESULTS: The MM successfully harvested marrow from a single entry sites and 2–3 paths under local anesthesia, without complications. Compared to standard harvest in the same patients, MM harvests had significantly number of Total Nucleated Cells ml compared to marrow harvested from the same patient by standard needle ( mean 1.98 fold greater TNC (range 0.87–3.36, p99). In addition to higher TNC/ml, significantly higher levels (mean 3.56 fold) of Aldeflour/ALDH+ cells/ml, CD34+, and phenotypic MSC (CD45−,34−,90+,105+) and endothelial progenitor cells were obtained, as measured by flow cytometry. Mean CD3+ T-cell counts per ml were lower with MM harvests. CONCLUSIONS: The novel FDA approved MarrowMiner system demonstrated safety and efficacy in clinical use, harvesting more stem cells per unit volume in a single entry compared to standard harvest methods. These results suggests the MM may enable improved clinical stem cell harvests in a more rapid and minimally invasive manner in the outpatient setting, while harvesting a richer marrow product with less peripheral blood contamination. Such a system, facilitating convenient, on demand stem cell collection may have significant application for BMT and other marrow based cellular therapies.
    Print ISSN: 0006-4971
    Electronic ISSN: 1528-0020
    Topics: Biology , Medicine
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2008-12-10
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Published by Springer Nature
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2003-12-22
    Print ISSN: 1544-9173
    Electronic ISSN: 1545-7885
    Topics: Biology
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...