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N G Testa

Publications and source records attributed to N G Testa.

At least 37 records · Page 2Linked to original sources
PubMed1998

CD34+AC133+ cells isolated from cord blood are highly enriched in long-term culture-initiating cells, NOD/SCID-repopulating cells and dendritic cell progenitors.

The AC133 antigen is a novel antigen selectively expressed on a subset of CD34+ cells in human fetal liver, bone marrow, and blood as demonstrated by flow cytometric analyses. In this study, we have further assessed the expression of AC133 on CD34+ cells in hemopoietic samples and found that there was a highly significant difference between normal bone marrow and cord blood versus aphereses (p <0.0001) but not between bone marrow and cord blood. Most of the clonogenic cells (67%) were contained in the CD34+AC133+ fraction. Compared with cultures of the CD34+AC133- cells, generation of progenitor cells in long-term culture on bone marrow stroma was consistently 10- to 100-fold higher in cultures initiated with CD34+AC133+ cells and was maintained for the 8-10 weeks of culture. Only the CD34+AC133+ cells were capable of repopulating NOD/SCID mice. Human cells were detectable as early as day 20, with increased levels (67%) apparent 40 days post-transplantation. Five thousand CD34+AC133+ cells engrafted about 20% of the mice, while no engraftment was observed in animals transplanted with up to 1.2 x 10(5) CD34+AC133- cells. The CD34+AC133+ population was also enriched (seven-fold) in dendritic cell precursors, and the dendritic cells generated were functionally active in a mixed lymphocyte reaction assay. AC133+ cells should be useful in the study of cellular and molecular mechanisms regulating primitive hemopoietic cells.

AC133 Antigen↗
PubMed1998

Stem cell factor leads to reduced blood processing during apheresis or the use of whole blood aliquots to support dose-intensive chemotherapy.

The addition of stem cell factor (SCF) to G-CSF and chemotherapy results in a dose-dependent, significantly increased mobilisation of peripheral blood progenitor cells compared with the use of chemotherapy and G-CSF alone. The enhanced mobilisation may benefit patients in several ways. Firstly, in clinical settings where currently multiple aphereses are having to be performed to obtain a specified target number of cells, the addition of SCF may lead to a reduction in this number. Alternatively, when only a single apheresis is currently being performed to obtain sufficient cells then the addition of SCF to the mobilisation regimen would allow between 5- and 8-fold reduction in the volume of blood required to be processed during the apheresis procedure to obtain a specified target of GM-CFC, CD34+ cells and LTC-IC for those receiving the highest dose of SCF (20 microg/kg) plus G-CSF following chemotherapy compared with those patients receiving G-CSF alone following chemotherapy. The increased mobilisation resulting from the addition of SCF to the regimen makes feasible the use of whole blood aliquots to support dose-intensive therapy. We have calculated that in patients mobilised using cyclophosphamide 3 g/m2, SCF 20 microg/kg and G-CSF 5 microg/kg a median 512 ml aliquot of whole blood would contain 2 x 10(6)/kg CD34+ cells and over 3.7 x 10(5)/kg GM-CFC. This aliquot would be sufficient to rescue the patient following a myeloablative therapy. Significantly, because less individual variation was seen after the administration of SCF the patient who showed the worst mobilisation in that group would have the usually required content of 2 x 10(6) CD34+ cells/kg and 1 x 10(5) GM-CFC/kg in only 731 ml of blood.

Adolescent↗
PubMed1998

Recombinant human megakaryocyte growth and development factor (MGDF) increases the numbers of megakaryocyte progenitor cells to normal values in long-term bone marrow cultures of patients with AML in first remission.

The megakaryopoietic potential in the bone marrow (BM) of patients in first remission after treatment for acute myelogenous leukaemia (AML) was investigated using long-term bone marrow cultures (LTC) stimulated with megakaryocyte growth and development factor (MGDF). The baseline number of megakaryocyte colony-forming cells (Meg-CFC) was very low. However, there was a 10 to 100-fold increase of Meg-CFC in cultures treated with 10 ng/ml MGDF with mean numbers within the normal range for the first 4 weeks of culture with a 24-fold increase in their cumulative numbers. Similarly, a 12-fold increase in the numbers of megakaryocytes (MKs) was found by CD61 immunostaining. These effects were lost at the dose of 100 ng/ml. In contrast, the cumulative mean numbers of Meg-CFC in the control cultures from normal bone marrow (NBM) were not significantly different from those in cultures treated with 10 or 100 ng/ml MGDF. These results demonstrate that MGDF stimulates megakaryocytopoiesis in patients with AML in first remission, restoring the Meg-CFC compartment to normal values, a result with potential clinical implications for their treatment with autologous transplantation.

Adult↗
PubMed1998

Factors which affect the CFU-GM content of the peripheral blood haemopoietic progenitor cell harvests in patients with acute myeloid leukaemia.

Autologous peripheral blood haemopoietic stem cells (PBSC) were harvested from 30 patients with de novo acute leukaemia, 29 of whom had entered remission following standard chemotherapy. Correlation of CD34+ cells/kg to CFU-GM/kg in the harvests was good (correlation coefficient = 0.72, P < 0.001). We demonstrated significant associations between the CFU-GM content of the harvest and the following: time to platelets >50 x 10(9)/l post final induction course (P < 0.001), days to harvest from day 1 of intensification/mobilization (correlation coefficient = -0.73, P < 0.001), platelets >20 x 10(9)/l at time of harvest (P = 0.02), time to WBC >1.0 x 10(9)/l post intensification/mobilization (correlation coefficient = -0.70, P < 0.001), and WBC on day of harvest (correlation coefficient = 0.60, P < 0.001). In contrast, we found no relationship between the CFU-GM content of the harvest and patient age up to 65 years, presence of absence of coexistent features of trilineage myelodysplasia at diagnosis, number of induction courses to remission or total number of courses of chemotherapy prior to intensification/mobilization. Haemopoietic recovery after reinfusion of PBSC was highly correlated to the number of CFU-GM infused (neutrophils >0.5 x 10(9)/l rs = -0.72, P = 0.001; platelets >20 x 10(9)/l unsupported rs = -0.71, P = 0.001). Our results show that the number of induction courses received, and thus exposure to cytotoxic agents received, made no significant difference to subsequent CFU-GM harvest content. We collected superior harvests from those patients with faster platelet recovery following mobilization therapy. We also found that faster platelet recovery following the final induction therapy was a better predictor of the CFU-GM harvest following mobilization than was the neutrophil recovery following final induction.

Acute Disease↗
PubMed1998

Randomized comparison of progenitor-cell mobilization using chemotherapy, stem-cell factor, and filgrastim or chemotherapy plus filgrastim alone in patients with ovarian cancer.

PURPOSE: This was the first randomized study to investigate the efficacy of peripheral-blood progenitor cell (PBPC) mobilization using stem-cell factor (SCF) in combination with filgrastim (G-CSF) following chemotherapy compared with filgrastim alone following chemotherapy. PATIENTS AND METHODS: Forty-eight patients with ovarian cancer were treated with cyclophosphamide and randomized to receive filgrastim 5 microg/kg alone or filgrastim 5 microg/kg plus SCF. The dose of SCF was cohort-dependent (5, 10, 15, and 20 microg/kg), with 12 patients in each cohort, nine of whom received SCF plus filgrastim and the remaining three patients who received filgrastim alone. On recovery from the WBC nadir, patients underwent a single apheresis. RESULTS: SCF in combination with filgrastim following chemotherapy enhanced the mobilization of progenitor cells compared with that produced by filgrastim alone following chemotherapy. This enhancement was dose-dependent for colony-forming unit-granulocyte-macrophage (CFU-GM), burst-forming unit-erythrocyte (BFU-E), and CD34+ cells in both the peripheral blood and apheresis product. In the apheresis product, threefold to fivefold increases in median CD34+ and progenitor cell yields were obtained in patients treated with SCF 20 microg/kg plus filgrastim compared with yields obtained in patients treated with filgrastim alone. Peripheral blood values of CFU-GM, BFU-E, and CD34+ cells per milliliter remained above defined threshold levels longer with higher doses of SCF. The higher doses of SCF offer a greater window of opportunity in which to perform the apheresis to achieve high yields. CONCLUSION: SCF (15 or 20 microg/kg) in combination with filgrastim following chemotherapy is an effective way of increasing progenitor cell yields compared with filgrastim alone following chemotherapy.

Adult↗
PubMed1998

Regulation of the proliferative potential of cord blood long-term culture-initiating cells (LTC-IC) by different stromal cell lines: implications for LTC-IC measurement.

BACKGROUND AND OBJECTIVE: Long-term culture-initiating cells (LTC-IC) are the best available approximation to an in vitro assay of stem cells in humans although they still represent a heterogeneous population in terms of proliferative capacity and sensitivity to different growth factors. Human umbilical cord blood (CB) is rich in hemopoietic progenitor cells, as measured by clonogenic assays and contains stem cells capable of reconstituting the marrow after ablation in clinical transplantation. We evaluated the influence of culture conditions on the in vitro behavior of LTC-IC from CB. DESIGN AND METHODS: LTC-IC were evaluated in long-term cultures, comparing two types of murine stromal cell lines: M2-10B4 and M2-10B4 transfected with cDNAs for human G-CSF and IL-3. RESULTS: Two and five fold higher numbers of terminally differentiated cells were produced during nine weeks of culture of CB mononuclear or CD34+ cells respectively, in cultures containing a M2-10B4 IL-3 G-CSF cell line compared to cultures containing the parental cell line. Likewise, a higher number of colony-forming cells (CFC) were detected in the supernatant of cultures with the transfected cell line. In contrast, the number of CFC generated within the stromal layer, after 5 or 9 weeks of culture, was significantly higher in cultures on M2-10B4 cells than those on M2-10B4 IL-3 G-CSF. INTERPRETATION AND CONCLUSIONS: Our results show that the proliferative capacity of CB LTC-IC can be strongly influenced by culture conditions and that the frequency of LTC-IC estimated using these cell lines as stromal support is not identical.

Cell Communication↗
PubMed1997

Investigation of mammary epithelial cell-bone marrow stroma interactions using primary human cell culture as a model of metastasis.

A model has been established using primary human cell culture to study the cell biology of breast cancer metastasis to bone marrow. Mammary epithelia were obtained in single cell suspension from tumour (macroscopically involved), benign (macroscopically uninvolved) and normal (reduction mammoplasty) breast tissue as well as from locally involved lymph nodes. Stromal layers were generated from long-term cultures of human bone marrow or from mammary fibroblasts derived from normal or malignant tissue. The interaction between epithelia and stroma has been studied in terms of adhesion of the epithelia to the stroma and their subsequent growth in co-culture. Our results show that when assayed up to 9 hr after plating, epithelial cells from malignant tissue (14 primary tumours and 9 metastases in lymph nodes) displayed a significant preference for adhesion to bone marrow stroma compared with mammary fibroblasts. In contrast, epithelial cells from 4 normal and 2 of 4 benign samples showed no significant preferential adherence. Subsequent co-culture of mammary epithelia with each of the 3 stromal layers revealed that under serum-free, in vitro conditions, bone marrow stromal layers did not provide an advantageous environment for colony growth, in contrast to their ability to provide a preferential substratum for adhesion.

Animals↗
PubMed1997

Primary prostatic epithelial cell binding to human bone marrow stroma and the role of alpha2beta1 integrin.

Prostate cancer selectively metastasises to the bone. To investigate the importance of prostate epithelial cell adhesion to bone marrow cells in this process we examined the binding of human primary prostatic epithelial cells (PEC) to human bone marrow stromal cultures (BMS). We found that PEC derived from both malignant and benign tissue showed greater adhesion to BMS than to benign prostatic fibroblasts (median difference was 340% and 200% respectively), skin fibroblasts or plastic tissue culture plates. Adhesion to BMS grown from the bone marrow of patients with prostatic skeletal metastases was no different from those grown from normal bone marrow. The role of integrin molecules in these cell interactions was determined. Collagen type I and fibronectin were found to increase PEC adhesion whereas vitronectin and laminin did not. Inhibition studies demonstrated that although there was heterogeneity between samples, antibodies against the integrins alpha2 and beta1 consistently inhibited PEC binding to BMS. This result was more marked for PEC derived from malignant tissue. However studies investigating the effects of disintegrins and anti-alpha3 and anti-alpha5 integrins indicated that for a percentage of patients these integrins and RGD (arginine, glycine, aspartamine)-dependent binding pathways were also involved. In summary, the results indicate that BMS are adherent to primary PEC derived from both malignant and benign tissue. The integrin alpha2beta1 is a major contributor to this interaction.

Animals↗
PubMed1997

Autografting in Philadelphia (Ph)+ chronic myeloid leukaemia using cultured marrow: an update of a pilot study.

Incubation of CML marrow in long-term culture (LTC) conditions may result in selection of normal (Ph-) LTC-initiating cells (LTC-IC) as early as 10 days, and in production of Ph- clonogenic cells and mature end cells within 5 weeks. This was the rationale for using marrow cells from 10-day-old LTC to autograft nine chronic phase CML patients, ineligible for HLA-matched sibling donor transplant, and who were selected on the basis of a pre-transplant screening LTC test. Of the transplanted patients three died; two of graft failure and one of therapy-related toxicity with 97% Ph- cells 16 months following the autograft. The reconstituting haemopoietic cells in the seven engrafted patients were 100% Ph- in four, > or = 90% Ph- in two and 71% Ph- in the seventh, with a duration of complete cytogenetic response of 6-12 months. Three patients reverted to chronic phase and 100% Ph+ haemopoiesis 27-36 months post-autograft. The other three patients remain in continuous haematological remission with 22% Ph- cells in one and complete cytogenetic remission in the other two 3-4 years post-autograft. IFN therapy was generally introduced on the first evidence of recurrence of Ph+ cells or of cytogenetic deterioration. Further strategies to modulate immune surveillance in vivo may improve the outcome of cultured marrow autografts which give an initial and rather prolonged bias towards Ph- haemopoiesis.

Adult↗
PubMed1997

High-dose granulocyte-colony stimulating factor (G-CSF) in vitro induces the growth of high proliferative potential colony forming cells (HPP-CFC) in patients undergoing blood stem cell mobilization.

We evaluated the role of high-dose granulocyte colony stimulating factor (G-CSF) in vitro, in inducing the generation of high-proliferative potential colony forming cells (HPP-CFC), from either mononuclear cells or purified CD34+ cells. Both normal controls and patients undergoing peripheral blood stem cell (PBSC) mobilization and transplantation were studied. In serum-driven agar cultures, G-CSF stimulated the proliferation of HPP-CFC in a dose dependent manner (r = 0.92). The number of HPP-CFC was four-fold greater in mobilized patients than in normal controls. Purified CD34+ cells yielded 11-fold more colonies than mononuclear cells. HPP-CFC from mobilized patients showed replating capacity, giving rise to secondary colonies of more mature appearance. In serum-free cultures, the effect of G-CSF appeared to be mediated by synergistic interaction with stem cell factor. Our results suggest that G-CSF stimulates primitive hematopoietic cells that are detectable in increased amounts in patients receiving mobilization therapy. Therefore, determination of G-CSF induced HPP-CFC could be a useful tool in the evaluation of mobilization strategies.

Antigens, CD34↗
PubMed1997

Measurement of long-term culture initiating cells (LTC-ICs) using limiting dilution: comparison of endpoints and stromal support.

Although much progress has been made in defining primitive cell phenotypes using flow cytometry and clonogenic assays, the direct study of marrow repopulating cells remains elusive. Long-term culture initiating cells (LTC-ICs) are arguably the most primitive human hematopoietic cells detectable by in vitro functional assays. Two endpoints have been reported for scoring LTC-ICs in limiting dilution assays. The first endpoint described was the generation of colony forming cells (CFCs) after 5 to 8 weeks of culture. An alternative method for scoring the LTC-IC assay is to identify cobblestone area forming cells. In the present study, estimations of LTC-IC frequency were made by measuring both endpoints and by comparing LTC-IC frequencies measured using limiting dilution assays of normal human bone marrow stroma with the measurements for murine bone marrow stromal cell line M2-10B4. For assays established on normal human bone marrow stroma, there was an equivalence between the two endpoint measures. Likewise, there was an equivalence between the two types of stroma when scoring CFC generation after 5 weeks. However, a consistently higher frequency of LTC-ICs was estimated when scoring cobblestone areas compared with that found when scoring CFC generation on the M2-10B4 stroma (p < 0.0001). Although the murine bone marrow stromal cell line M2-10B4 remains a very useful and consistently reliable alternative to normal human bone marrow stroma, these data indicate that the LTC-IC populations defined by scoring cobblestone areas or by measuring the generation of CFCs on this cell line are, in contrast to those measured using bone marrow stroma, not identical.

Animals↗
PubMed1996

Increased numbers of long-term culture-initiating cells in the apheresis product of patients randomized to receive increasing doses of stem cell factor administered in combination with chemotherapy and a standard dose of granulocyte colony-stimulating factor.

Long-term culture-initiating cells (LTC-IC) are arguably the most primitive human hematopoietic cells detectable by in vitro functional assays. We have investigated the mobilization of these cells into the blood of patients with ovarian carcinoma randomized to receive granulocyte colony-stimulating factor (G-CSF; 5 micrograms/kg) plus different doses of stem cell factor (SCF; c-kit ligand) after chemotherapy or G-CSF alone after chemotherapy. We have shown a significant SCF dose response for the mobilization of LTC-IC, with a 5.8-fold increase in LTC-IC mobilization in those patients receiving chemotherapy, G-CSF, and 20 micrograms/kg of SCF, the highest dose used, compared with the patients receiving chemotherapy and G-CSF alone. We have shown a threefold increase in CD34+ cells and up to a 64-fold increase in CD34+/33- cells was seen in patients treated with chemotherapy, G-CSF, and 20 micrograms/kg of SCF compared with those patients treated with chemotherapy and G-CSF alone. However, significant numbers of CD34+/38- cells were only found in the patients receiving 20 micrograms/kg of SCF as part of their mobilization regimen. Patients receiving chemotherapy plus G-CSF and SCF have enhanced mobilization of primitive cells and of the more committed progenitor cells compared with those patients receiving chemotherapy followed by G-CSF alone.

Adolescent↗
PubMed1996

Extensive amplification of single cells from CD34+ subpopulations in umbilical cord blood and identification of long-term culture-initiating cells present in two subsets.

CD34+ cord blood cells were isolated with immunomagnetic beads and fractionated by fluorescence-activated cell sorting (FACS) into three subpopulations: CD34+38+DR+, CD34+38-DR+ and CD34+38-DR-, using antibodies specific for these cell surface markers. Cells from each of the three subsets were plated as single cells in serum-free medium supplemented with a combination of growth factor and individual cells were monitored for proliferation and the capacity to form colony-forming cells. Single cells from the CD34+38+DR+ subset showed the lowest expansion capacity, generating up to 1.1 x 10(6) cells at five weeks, while individual cells from both the CD34+38-DR+ and CD34+38-DR- subsets could be expanded up to 1.8 x 10(6) and 9.2 x 10(6) cells, respectively, over a period of six weeks. The different subpopulations also generated colony-forming cells which gave rise to erythroid, myeloid and erythroid/myeloid colonies. CD34+38-DR+ cells generated large numbers of colonies within two weeks in liquid culture, but this rapidly declined. Generation of lineage-committed colony-forming cells was better sustained in the CD34+38-DR- population and continued for up to six weeks in culture. Overall, the generation of colony-forming cells declined with time in culture, although the cell numbers continued to expand. However, when the same populations were plated on irradiated bone marrow stroma, both the CD34+38-DR+ and the CD34+38-DR- cells were capable of producing granulocytemacrophage colony-forming cells (GM-CFCs) for 10 to 12 weeks. As hemopoiesis was sustained for almost three months, it appears that these populations were significantly enriched in long-term culture-initiating cells (LTC-ICs). Although both populations generated GM-CFCs, the CD34+38-DR- cells sustained production of higher numbers of colony-forming cells than the CD34+38-DR+ population. These results demonstrate that cells from cord blood can be efficiently monitored at the single-cell level for proliferation, expansion and colony-forming capacity. Furthermore, at least two populations of LTC-ICs can be distinguished in cord blood CD34+38- cells by the differential expression of the HLA-DR antigen.

ADP-ribosyl Cyclase↗
PubMed1996

A study of ovarian cancer patients treated with dose-intensive chemotherapy supported with peripheral blood progenitor cells mobilised by filgrastim and cyclophosphamide.

We have shown that large numbers of haemopoietic progenitor cells are mobilised into the blood after filgrastim [granulocyte colony-stimulating factor (G-CSF)] alone and filgrastim following cyclophosphamide chemotherapy in previously untreated patients with ovarian cancer. These cells may be used to provide safe and effective haemopoietic rescue following dose-intensive chemotherapy. Using filgrastim alone (10 micrograms kg-1), the apheresis harvest contained a median CFU-GM count of 45 x 10(4) kg-1 and 2 x 10(6) kg-1 CD34+ cells. Treatment with filgrastim (5 micrograms kg-1) following cyclophosphamide (3 g m-2) resulted in a harvest containing 66 x 10(4) kg-1 CFU-GM and 2.4 x 10(6) kg-1 CD34+ cells. There was no statistically significant difference between these two mobilising regimens. We have also demonstrated that dose-intensive carboplatin and cyclophosphamide chemotherapy can be delivered safely to patients with ovarian cancer when supported by peripheral blood progenitor cells and filgrastim. Carboplatin (AUC 7.5) and cyclophosphamide (900 mg m-2) given at 3 weekly intervals with progenitor cell and growth factor support was well tolerated in terms of haematological and systemic side-effects. Double the dose intensity of chemotherapy was delivered compared with our standard dose regimen when the treatment was given at 3 weekly intervals. Median dose intensity could be further escalated to 2.33 compared with our standard regimen by decreasing the interval between treatment cycles to 2 weeks. However, at this dose intensity less than a third of patients received their planned treatment on time. All the delays were due to thrombocytopenia.

Adult↗
PubMed1996

Evaluation of cytogenetic conversion to Ph- haemopoiesis in long-term bone marrow culture for patients with chronic myeloid leukaemia on conventional hydroxyurea therapy, on pulse high-dose hydroxyurea and on interferon-alpha.

Long-term bone marrow culture (LTBMC) has been used successfully in autologous transplantation in chronic myeloid leukaemia (CML). However, variation between patients in the recovery of Ph- cells in culture limits the application of this procedure to a minority. Treatment that effectively reduces in vivo tumour burden prior to initiation of LTBMC may improve the selection of Ph- cells in culture. To test this hypothesis we evaluated the frequency and degree of cytogenetic conversion to Ph- haemopoiesis in LTBMC from four independent groups of CML patients: Untreated (n = 19); conventional dosage of hydroxyurea (HU) (n = 10); pulse high-dose HU (P-HU) (n = 22) and interferon (IFN)-alpha (n = 12). In this study IFN-alpha therapy resulted in a significantly higher incidence of patients with detectable Ph- clonogenic cells in the marrow (P = 0.01) and with > or = 50% Ph- haemopoiesis in LTBMC as compared to newly diagnosed patients (P = 0.05). Also, sequential culture studies undertaken in 14 CML patients at diagnosis and following the start of pulse highdose HU therapy showed that in eight patients the average proportion of Ph- metaphases detected in LTBMC substantially increased from 1.7% (range 0-7) at diagnosis to levels of 71% (range 14-100) after treatment. Therefore we conclude that the use of IFN or pulse high-dose HU in early stage disease appears to create an opportunity to harvest the marrow for long-term culture (LTC) purging with reduced leukaaemic burden.

Adult↗
PubMed1996

The relative spatial distribution of in vitro-CFCs in the bone marrow, responding to specific growth factors.

Haemopoietic progenitor cells are stimulated by a range of growth factors which promote colony growth in culture. The progenitors are a part of an age-structured developmental hierarchy in the tissue. The growth factors, although overlapping in their effects, stimulate cells preferentially at different stages in this programme. Femoral bone marrow was fractionated into axial (close to the central venous sinus) and marginal (close to the bone surface) cells. Progenitors which responded to IL-3, GM-CSF, G-CSF, M-CSF and SCF were then assayed in soft agar cultures. Consequent plots of their spatial distributions showed that the more primitive cells in vitro (responding to IL-3) were concentrated close to the bone surface. The peak concentrations of cells responding primarily to growth factors with progressively more affinity to more mature progenitor cells correspondingly appeared progressively further from the bone surface and closer to the point of release at the central venous sinus. This suggests that the developmental/maturational process in haemopoiesis is accompanied by a progressive movement of cells from the bone surface towards the central axial regions of the bone cavities. The most primitive cells are however exposed, close to the centre of the cavity, by a combination of SCF and G-CSF (or by a 50-fold increase in G-CSF concentration alone). These results corroborate earlier data which indicate a developmental movement of cells from the centre of the marrow tissue towards the bone surface and back again, sequentially encountering a series of growth factors which promote their differentiation into mature cells, for release at the central venous sinus.

Animals↗