Combination Of Granulocyte Colony-stimulating Factor Research Articles

Protection of taurine and granulocyte colony-stimulating factor against excitotoxicity induced by glutamate in primary cortical neurons

sBackgroundBoth taurine, an inhibitory neurotransmitter and granulocyte colony-stimulating factor (G-CSF), a growth factor, possess neuroprotective and neurotrophic properties in vitro. However, the mechanisms of their underlying neuroprotective effects are not fully understood.MethodsIn the present study, we investigated the potential protective benefits of taurine, G-CSF and the combination of taurine and G-CSF against excitotoxicity induced by glutamate in primary cortical neuronal cultures.Results25 mM taurine, 25 ng/ml G-CSF and the combination of 25 mM taurine and 25 ng/ml G-CSF showed a protective effect reaching 75%, 75% and 88%, respectively. Furthermore, taurine exerted its protective effect through down-regulation of expression of GRP 78, CHOP, Bim and caspase 12.ConclusionThe results showed that all of these treatments, taurine, G-CSF and the combination of taurine and G-CSF, protected primary cortical neurons against excitotoxicity induced by glutamate. ER stress is suppressed by taurine after glutamate toxicity.

Cell Cycle-Dependent Priming Action of Granulocyte Colony-Stimulating Factor (G-CSF) Enhances in vitro Apoptosis Induction by Cytarabine and Etoposide in Leukemia Cell Lines

We investigated the priming effect and mechanism of granulocyte colony-stimulating factor (G-CSF) in chemotherapy with low-dose Ara-C and VP-16 for acute myeloid leukemia. We analyzed cell proliferation, apoptosis, and cell cycle in vitro using leukemia cell lines 32Dcl3, U937, HL-60, and Ba/F3. Cell proliferation assays were performed using the Trypan Blue dye exclusion method. For detection of apoptosis, the Annexin V-binding capacity of treated cells was examined by flow cytometry. To evaluate the cell cycle, we used an FITC BrdU Flow kit and conducted analysis by flow cytometry. The combination of Ara-C and VP-16 significantly enhanced the observed effects compared with those of Ara-C or VP-16 alone. Concurrent administration of G-CSF further reduced the cell number and viability of 32Dcl3 and U937 cells, but not of HL-60 and Ba/F3 cells. Apoptotic cells were significantly increased in number by the addition of G-CSF to 32Dcl3 and U937 cells, while G-CSF had no significant effect on HL-60 and Ba/F3 cell lines. The addition of G-CSF significantly decreased the percentage of G0/G1-phase cells and significantly increased that of S-phase cells among 32Dcl3 and U937 cells. No significant effect was observed for HL-60 and Ba/F3 cells. An enhancement was confirmed for the combination of Ara-C, VP-16, and G-CSF for 32Dcl3 and U937 cells but not for HL-60 and Ba/F3 cells. It was thought that this difference was a result of different responses to G-CSF. G-CSF potentiates Ara-C- and VP-16-induced cytotoxicities through apoptosis induction by mobilizing resting G0-G1-phase cells into S phase.

Mobilization of PML/RAR negative peripheral blood stem cells with a combination of G-CSF and CXCR4 blockade in relapsed acute promyelocytic leukemia pre-treated with arsenic trioxide

Mobilization of PML/RAR negative peripheral blood stem cells with a combination of G-CSF and CXCR4 blockade in relapsed acute promyelocytic leukemia pre-treated with arsenic trioxide

BIO5192, a small molecule inhibitor of VLA-4, mobilizes hematopoietic stem and progenitor cells

AbstractHere we show that interruption of the VCAM-1/VLA-4 axis with a small molecule inhibitor of VLA-4, BIO5192, results in a 30-fold increase in mobilization of murine hematopoietic stem and progenitors (HSPCs) over basal levels. An additive affect on HSPC mobilization (3-fold) was observed when plerixafor (AMD3100), a small molecule inhibitor of the CXCR-4/SDF-1 axis, was combined with BIO5192. Furthermore, the combination of granulocyte colony-stimulating factor (G-CSF), BIO5192, and plerixafor enhanced mobilization by 17-fold compared with G-CSF alone. HSPCs mobilized by BIO5192 or the combination of BIO5192 and plerixafor mobilized long-term repopulating cells, which successfully engraft and expand in a multilineage fashion in secondary transplantation recipients. Splenectomy resulted in a dramatic enhancement of G-CSF–induced mobilization while decreasing both plerixafor- and BIO5192-induced mobilization of HSPCs. These data provide evidence for the utility of small molecule inhibitors of VLA-4 either alone or in combination with G-CSF or AMD3100 for mobilization of hematopoietic stem and progenitor cells.

Phase II study of rabbit anti-thymocyte globulin, cyclosporine and granulocyte colony-stimulating factor in patients with aplastic anemia and myelodysplastic syndrome

We investigated efficacy and safety of rabbit anti-thymocyte globulin (rATG), cyclosporine and granulocyte colony-stimulating factor (G-CSF) as first-line therapy for patients with aplastic anemia (AA) and low or intermediate-1 or hypoplastic myelodysplastic syndrome (MDS). rATG 3.5 mg/kg (or 2.5 mg/kg per day for patients >or=55 years with MDS) was given for 5 days. Cyclosporine (5 mg/kg) and G-CSF (5 microg/kg) were given daily and continued for up to 6 months or longer. Responses were assessed about 3 and 6 months after therapy. Thirty-six patients have been enrolled on study and 32 patients treated; 25 were evaluable for a response (13 with AA, 12 with MDS); the rest are too early. The median age was 62 years (range, 20-83) for patients with AA and 63 (range, 42-80) for patients with MDS. Of 13 patients, 12 (92%) patients with AA responded (5 complete response (CR), 7 partial response (PR)), whereas of 12 patients, 4 (33%) patients with MDS responded (1 CR, 3 PR). For patients with AA, the median time to response (TTR) was 93 days (range, 79-623), whereas in the MDS group the median TTR was 111 days (range, 77-139). Grade III/IV toxicities were mainly cytopenias and neutropenic fever. Combination of rATG, cyclosporine and G-CSF is safe and effective as first-line treatment of AA and has significant activity in low-risk MDS.

Cellular preservation therapy in acute myocardial infarction

the past decade has been characterized by unprecedented progress in cardiac cell biology and pathophysiology. The dogma of the heart being a terminally differentiated organ has been challenged by compelling evidence generated in several different laboratories around the world ([6][1]). These

Effects of granulocyte colony-stimulating factor and stem cell factor, alone and in combination, on the biological behaviours of bone marrow mesenchymal stem cells

Aim: The effects of granulocyte colony- stimu-lating factor (G-CSF) and stem cell factor (SCF) on the proliferation and osteogenic differentia-tion capacity of bone marrow mesenchymal stem cells (MSCs) were studied in the experi-ment. Methods: Bone marrow MSCs were col-lected from rabbits successfully, and treated with various concentrations of G-CSF, SCF or a combination of the two. Flow cytometric ana-lyse, MTT test, CFU-F assay, and alkaline phosphatase (ALP) activity measurement were employed. Results: The results of flow cytome-try showed that immunophenotype of the cells were CD29+/CD45-, CD105+/ CD34–, CD90+/ HLADR–. MSCs were shown to constitutively express low levels of c-kit which could be en-hanced by SCF. G-CSF and SCF had an obvious facilitative effect on the proliferation of MSCs in a dose-dependent fashion. In addition, G-CSF and SCF would be effective in reversibly pre-venting their differentiation, as showed by the decrease of ALP activity, leading to self-renewal rather than differentiative cell divisions. The effects of G-CSF were superior to SCF. And cells in the group treated with combination of G-CSF and SCF showed more powerful effects than the groups treated with G-CS, SCF, or none of the two. Conclusion: On the whole, these studies demonstrated that MSCs responsed to G-CSF, SCF, and to G-CSF plus SCF in a manner that suppressed differentiation, and promotes proliferation and self-renewal, and support the view that these factors could act synergistically.

T.8. Amelioration of Insulitis and Reversal of Diabetes in NOD Mice by Murine Anti-Thymocyte Globulin and Granulocyte-Colony Stimulating Factor Combination Therapy

T.8. Amelioration of Insulitis and Reversal of Diabetes in NOD Mice by Murine Anti-Thymocyte Globulin and Granulocyte-Colony Stimulating Factor Combination Therapy

A Combination of Granulocyte Colony-Stimulating Factor and Stem Cell Factor Ameliorates Steroid- Associated Osteonecrosis in Rabbits

Bone marrow-derived stem cells (BMSC) have been highlighted for the treatment of osteonecrosis (ON) before collapse of the femoral head. In our study, the potential of granulocyte colony-stimulating factor/stem cell factor (G-CSF/SCF)-mobilized BMSC to repair steroid-associated ON was assessed in rabbits. ON was induced by low-dose lipopolysaccharide and subsequent pulsed high-dose methylprednisolone. Rabbits in the treated group were subjected to subcutaneous injections of G-CSF at a dose of 100 microg/kg and SCF 25 microg/kg per day for 5 days; rabbits in the control group were given saline. Blood samples were collected and serum osteocalcin was detected by ELISA. Radiological analysis was performed by magnetic resonance imaging (MRI). Then bilateral femora and humeri were harvested and processed to paraffin sections and hard-tissue sections for immunohistochemical, histologic, and histomorphometric analysis. . The mean number of leukocytes and relative numbers of mononuclear cells increased significantly after mobilization. All rabbits displayed a marked increase in osteocalcin protein expression in response to G-CSF/SCF. MRI scans showed a reactive interface between the necrotic and reparative zones after G-CSF/SCF administration. Quantitative analysis showed that new vessel formation was 3.3-fold greater and vessel density was 2.6-fold greater in the treatment group than the control group. The histologic and histomorphometric analysis revealed that the new bone volume was significantly higher in the G-SCF/SCF group than in the control group at 4 weeks. G-CSF/SCF-induced mobilization of BMSC in the necrotic foci may represent a promising strategy for promoting functional bone repair of early-stage ON.

Improved Granulocyte Colony-Stimulating Factor Mobilization of Hemopoietic Progenitors Using Cytokine Combinations in Primates

Peripheral blood stem cells (PBSCs), usually mobilized with granulocyte colony-stimulating factor (G-CSF) alone or in combination with chemotherapy, are the preferred source of cells for hemopoietic stem cell transplantation. Up to 25% of otherwise eligible transplant recipients fail to harvest adequate PBSCs. Therefore it is important to investigate existing and novel reagents to improve PBSC mobilization. Because of marked interindividual variation in humans, we developed a robust nonhuman primate model that allows the direct comparison of the efficacy of two PBSC mobilization regimens within the same animal. Using this model, we compared pegylated G-CSF (pegG-CSF) with standard G-CSF and compared the combination of G-CSF and pegylated megakaryocyte growth and development factor (pegMGDF) with G-CSF plus stem cell factor (SCF) by measuring the levels of CD34(+) cells, colony-forming cells (CFCs), and SCID repopulating cells (SRCs) before and after cytokine administration. Mobilization of CD34(+) cells, CFCs and SRCs using pegG-CSF achieved similar levels to those resulting from 5 days of standard G-CSF. The combination of G-CSF+pegMGDF mobilized progenitors to levels similar to G-CSF+SCF but greater than standard G-CSF for CD34(+) cells and CFC. This first direct comparison of PBSC mobilization in individual primates demonstrates that peg-G-CSF is equivalent to daily G-CSF and that the addition of pegMGDF to G-CSF improves mobilization. In light of the development of new thrombopoietin agonists, these data offer the potential for improved stem cell mobilization strategies. Disclosure of potential conflicts of interest is found at the end of this article.

Granulocyte-colony stimulating factor upregulates ErbB2 expression on breast cancer cell lines and converts primary resistance to trastuzumab

The recombinant monoclonal antibody trastuzumab has antiproliferative effect on breast cancer (BC) cells with ErbB2 overexpression. We postulated that a mechanism able to modify ErbB2 expression enhances the antitumor effect of trastuzumab. We analyzed whether granulocyte-colony stimulating factor (G-CSF), widely used in adjuvant cancer therapy to alleviate chemotherapy-induced myelotoxicity, could influence ErbB2 expression in BC cells and patients. The expression of ErbB2 (Herceptest) was analyzed in four BC cell lines (BT474, SKBR3, ZR75.1, and T47D) treated with G-CSF and in five samples biopsies from BC patients subjected to G-CSF rescue after chemotherapy. The effects of G-CSF and trastuzumab alone or their combination on cell growth and apoptosis were investigated. G-CSF receptor was detected on all cell lines and BC patients. G-CSF induced upregulation of ErbB2 in SKBR3, ZR75, and T47D cells. This modulation was not associated with an increase in tumor cell growth in vitro. Trastuzumab alone inhibited colony formation in soft agar but did not induce apoptosis on BC cells with no or low ErbB2 genomic amplification. The combination of trastuzumab and G-CSF enhanced the inhibition of tumor colony formation and induced apoptosis on these cells. This effect was further increased by G-CSF pretreatment. Five of nine BC patients showed an increase of Herceptest score after G-CSF administration. G-CSF treatment increases ErbB2 expression in vitro and in vivo enhancing the activity of trastuzumab on BC cell lines inducing apoptosis of BC cells with low or no ErbB2 genomic amplification.

The combination of granulocyte colony-stimulating factor and stem cell factor significantly increases the number of bone marrow–derived endothelial cells in brains of mice following cerebral ischemia

AbstractGranulocyte colony-stimulating factor (G-CSF) induces proliferation of bone marrow–derived cells. G-CSF is neuroprotective after experimental brain injury, but the mechanisms involved remain unclear. Stem cell factor (SCF) is a cytokine important for the survival and differentiation of hematopoietic stem cells. Its receptor (c-kit or CD117) is present in some endothelial cells. We aimed to determine whether the combination of G-CSF/SCF induces angiogenesis in the central nervous system by promoting entry of endothelial precursors into the injured brain and causing them to proliferate there. We induced permanent middle cerebral artery occlusion in female mice that previously underwent sex-mismatched bone marrow transplantation from enhanced green fluorescent protein (EGFP)–expressing mice. G-CSF/SCF treatment reduced infarct volumes by more than 50% and resulted in a 1.5-fold increase in vessel formation in mice with stroke, a large percentage of which contain endothelial cells of bone marrow origin. Most cells entering the brain maintained their bone marrow identity and did not transdifferentiate into neural cells. G-CSF/SCF treatment also led to a 2-fold increase in the number of newborn cells in the ischemic hemisphere. These findings suggest that G-CSF/SCF treatment might help recovery through induction of bone marrow–derived angiogenesis, thus improving neuronal survival and functional outcome.

Parathyroid hormone effectively induces mobilization of progenitor cells without depletion of bone marrow

Cytokine-mediated mobilization of hematopoietic stem cells has become an established method in the field of autologous and allogenic stem cell transplantation. Furthermore, it presents a new concept in tissue repair and regenerative medicine. In the present study, we explored the potency of parathyroid hormone (PTH) compared to granulocyte colony-stimulating factor (G-CSF) for mobilization of stem cells and its regenerative capacity on bone marrow. Healthy mice were either treated with PTH, G-CSF, or saline. Laboratory parameters were analyzed using a hematological cell analyzer. Hematopoietic stem cells characterized by lin(-)/Sca-1(+)/c-kit(+), as well as subpopulations (CD31(+), c-kit(+), Sca-1(+), CXCR4(+)) of CD45(+)/CD34(+) and CD45(+)/CD34(-) cells were measured by flow cytometry. Immunohistology as well as fluorescein-activated cell sorting analyses were utilized to determine the composition and cell-cycle status of bone marrow cells. Serum levels of distinct cytokines (G-CSF, vascular endothelial growth factor [VEGF]) were determined by enzyme-linked immunosorbent assay. Further, circulating cells were measured after PTH treatment in combination with G-CSF or a G-CSF antibody. Stimulation with PTH showed a significant increase of all characterized subpopulations of bone marrow-derived progenitor cells (BMCs) in peripheral blood (1.5- to 9.8-fold) similar to G-CSF. In contrast to G-CSF, PTH treatment resulted in an enhanced cell proliferation with a constant level of lin(-)/Sca-1(+)/c-kit(+) cells and CD45(+)/CD34(+) subpopulations in bone marrow. Interestingly, PTH application was associated with increased serum levels of G-CSF (2.8-fold), whereas VEGF showed no significant changes. Blocking endogenous G-CSF with an antibody significantly reduced the number of circulating cells after PTH treatment. A combination of PTH and G-CSF showed slight additional effects compared to PTH or G-CSF alone. PTH induces mobilization of progenitor cells effectively, which can be related to an endogenous release of G-CSF. In contrast to G-CSF treatment, PTH does not result in a depletion of bone marrow, which may be mediated by an activation of PTH receptor on osteoblasts. The novel function of PTH on mobilization and regeneration of BMCs may pave the way for new therapeutic options in bone marrow and stem cell transplantation as well as in the field of ischemic disorders.

Management strategies for poor peripheral blood stem cell mobilization

Peripheral blood stem cells (PBSC) have nearly replaced bone marrow (BM) as the preferred source of hematopoietic rescue for patients undergoing high-dose chemotherapy. However, some patients fail to mobilize sufficient numbers of PBSC into the peripheral blood thereby putting high-dose chemotherapy at risk. The present article reviews mobilization of PBSC with a special focus on poor mobilizers. Under steady-state conditions less than 0.05% of the white blood cells (WBC) are CD34+ cells. Chemotherapy results in a 5–15-fold increase of PBSC. Combining chemotherapy and growth factors increases CD34+ cells up to 6% of WBC. Several factors affect the mobilization of PBSC: age, gender, type of growth factor, dose of the growth factor and in the autologous setting patient’s diagnosis, chemotherapy regimen and number of previous chemotherapy cycles or radiation. Poor mobilizers are defined as patients with less than 10 CD34+ cells/μl in the peripheral blood during mobilization. Promising approaches for those patients rely on remobilization, use of high doses of granulocyte-colony stimulating factor (G-CSF), or the combination of G-CSF and granulocyte macrophage (GM)-CSF, which successfully mobilized the majority of poor mobilizing patients. New agents such as long lasting variants of G-CSF and CXCR4 antagonists are at the horizon and studied in clinical trials as mobilizing agents. Muscle and bone pain are frequent adverse events in stem cell mobilization but are usually tolerated under the use of analgesics. Large volume apheresis (LVL) with a processed volume of more than 4-fold patient’s blood volume is an approach to increase the CD34+ yield in patients with low CD34+ pre-counts resulting in higher yields of CD34+ cells for transplantation. Processing of more blood in LVL is achieved by an increase of the blood flow rate and an altered anticoagulation regimen with the occurrence of more citrate reactions.

Differential effects of antibiotics in combination with G-CSF on survival and polymorphonuclear granulocyte cell functions in septic rats

BackgroundIn addition to their antimicrobial activity, antibiotics modulate cellular host defence. Granulocyte-colony stimulating factor (G-CSF) is also a well known immunomodulator; however little is known about the interactions of G-CSF with antibiotics. We investigated in septic rats the effects of two antibiotic combinations with G-CSF.MethodsIn two clinic modelling randomised trials (CMRTs), male Wistar rats were anesthetized, given antibiotic prophylaxis, had a laparotomy with peritoneal contamination and infection (PCI), and were randomly assigned (n = 18 rats/group) to: 1) PCI only; 2) PCI+antibiotic; and, 3) PCI+antibiotic+G-CSF prophylaxis (20 μg/kg, three times). This sequence was conducted first with 10 mg/kg coamoxiclav, and then with ceftriaxone/metronidazole (Cef/met, 10/3 mg/kg). In additional animals, the blood cell count, migration and superoxide production of PMNs, systemic TNF-α and liver cytokine mRNA expression levels were determined.ResultsOnly the combination coamoxiclav plus G-CSF improved the survival rate (82 vs. 44%, p < 0.001). Improved survival with this combination was accompanied by normalised antimicrobial PMN migratory activity and superoxide production, along with normalised systemic TNF-α levels and a reduced expression of TNF-α and IL-1 in the liver.ConclusionThere are substantial differences in the interaction of antibiotics with G-CSF. Therefore, the selection of the antibiotic for combination with G-CSF in sepsis treatment should be guided not only by the bacteria to be eliminated, but also by the effects on antimicrobial functions of PMNs and the cytokine response.

G-CSF treatment after myocardial infarction: Impact on bone marrow—derived vs cardiac progenitor cells

Besides its classical function in the field of autologous and allogenic stem cell transplantation, granulocyte colony-stimulating factor (G-CSF) was shown to have protective effects after myocardial infarction (MI) by mobilization of bone marrow-derived progenitor cells (BMCs) and in addition by activation of multiple signaling pathways. In the present study, we focused on the impact of G-CSF on migration of BMCs and the impact on resident cardiac cells after MI. Mice (C57BL/6J) were sublethally irradiated, and BM from green fluorescent protein (GFP)-transgenic mice was transplanted. Coronary artery ligation was performed 10 weeks later. G-CSF (100 microg/kg) was daily injected for 6 days. Subpopulations of enhanced GFP(+) cells in peripheral blood, bone marrow, and heart were characterized by flow cytometry. Growth factor expression in the heart was analyzed by quantitative real-time polymerase chain reaction. Perfusion was investigated in vivo by gated single photon emission computed tomography (SPECT). G-CSF-treated animals revealed a reduced migration of c-kit(+) and CXCR-4(+) BMCs associated with decreased expression levels of the corresponding growth factors, namely stem cell factor and stromal-derived factor-1 alpha in ischemic myocardium. In contrast, the number of resident cardiac Sca-1(+) cells was significantly increased. However, SPECT-perfusion showed no differences in infarct size between G-CSF-treated and control animals 6 days after MI. Our study shows that G-CSF treatment after MI reduces migration capacity of BMCs into ischemic tissue, but increases the number of resident cardiac cells. To optimize homing capacity a combination of G-CSF with other agents may optimize cytokine therapy after MI.

Synergistic effect of erythropoietin but not G-CSF in combination with curcumin on impaired liver regeneration in rats

The effect of erythropoietin (Epo) and granulocyte colony-stimulating factor (G-CSF) alone or in combination with the hepatoprotective antioxidant curcumin (Cur) was evaluated in a model of delayed liver regeneration. Sprague Dawley rats underwent 70% liver resection with simultaneous cecal ligation and puncture and were randomised to five groups: no treatment, G-CSF (100 microg/kg), Epo (1,000 IU/kg), each alone or in combination with Cur (100mg/kg). Twenty-four hours after surgery, blood and tissue samples were collected. Markers of liver regeneration (liver weight, mitotic index, Ki-67 index), function (bilirubin, bile flow) and hepatocellular damage (liver enzymes, histomorphology) were determined. In addition, cytokine expression and hepatic glutathione concentrations were measured. Liver regeneration was not improved by G-CSF or Epo monotherapy. Epo more effectively increased liver weight and regeneration markers, but the difference was not significant. Whereas liver regeneration was slightly inhibited in the G-CSF plus Cur group, Epo plus Cur significantly improved liver regeneration. This was accompanied by reduced oxidative stress. Liver function and the expression of pro-inflammatory cytokines were comparable in all treatment groups. In the present model, Epo, at a relatively low dosage, did not improve liver regeneration. However, the combination of Epo and Cur showed a synergistic effect with highly significant stimulation of liver regeneration.

Hepatocyte growth factor and granulocyte colony-stimulating factor form a combined neovasculogenic therapy for ischemic cardiomyopathy

Myocardial infarction (MI) is a significant cause of heart failure. Current therapies are limited and, therefore, the development of novel revascularization methods is potentially important. We investigated whether hepatocyte growth factor (HGF), expressed by genetically modified mesenchymal stromal cells (MSC), in combination with granulocyte colony-stimulating factor (G-CSF), exhibited a synergistic therapeutic benefit, as measured 8 weeks after MI induction in a rat model. Four weeks after MI, rats were randomly divided into a control group (n=11), HGF group (Adenovirus vector carrying human HGF (Ad-HGF)-transfected MSC transplanted into the infarct zone; n=11), G-CSF group (intraperitoneal injection with G-CSF; n=11), and HGF + G-CSF group (Ad-HGF-transfected MSC transplanted into the infarct zone and intraperitoneal injection with G-CSF; n=11). Four weeks later, hearts were analyzed for endothelial cell density and angiogenesis, ventricular geometry, myocardial function and levels of VCAM-1 and MMP-9 protein. The HGF + G-CSF group exhibited improved left ventricular systolic and diastolic function and experienced less adverse ventricular remodeling, as manifested by decreased left ventricular dilatation and increased border zone wall thickness. Angiogenesis was significantly enhanced in HGF + G-CSF rats by inducing the proliferation of endothelial cells. Furthermore, HGF induced expression of VCAM-1, and HGF treatment together with G-CSF synergistically stimulated MMP-9 expression in ischemic hearts. The combination of G-CSF and HGF exhibited a significant synergistic effect and enhanced myocardial endothelial density, angiogenesis, geometric preservation and heart function in an ischemic cardiomyopathy model.

Angiogenesis Achieved by Granulocyte Colony-Stimulating Factor in Combination With Bypass Surgery in 2 Cases of Critical Limb Ischemia

Patients demonstrating critical limb ischemia with a long-distance occlusion of the major arteries are sometimes poor candidates for bypass surgery, because tandem occlusion complicates distal anastomoses and poor run-off causes early occlusion of bypass grafts. In order to resolve these problems, angiogenesis therapy was attempted by subcutaneous injection of granulocyte colony-stimulating factor either before or after peripheral bypass surgery in 2 cases.

Intensive Supportive Care and Cytokines Promote Recovery of Hematopoiesis after Total Body Irradiation (TBI) without Hematopoietic Stem Cell Support.

Hematopoietic cells are highly sensitive to radiation damage and their loss after radiation exposure results in lethal infections. We asked if intensive supportive care and hematopoietic-specific cytokine treatment after doses of TBI that were previously identified as lethal would permit survival and promote recovery of endogenous hematopoiesis without requiring hematopoietic stem cell support in the well-established dog model. Historical results showed that after 4 Gy TBI and standard supportive care, only 1 of 28 dogs survived with recovery of endogenous hematopoiesis. The intensive supportive care regimen for dogs after irradiation included an antibiotic use algorithm for empiric treatment of prolonged neutropenia and fever. After TBI exposure, dogs were treated with an oral fluoroquinolone. If fever developed or when absolute neutrophil count (ANC) fell below 100/μL, dogs were empirically treated with the combination of intravenous ceftazidime and amikacin. Blood cultures were obtained with fevers, and antibiotics were adjusted based on culture results. If neutropenic fever persisted for 48 hours, additional empiric antibiotic treatment was added. Blood transfusion support included increased volume and frequency of irradiated blood products. Intravenous fluid support (10–30 mL/kg/day Lactated Ringer's solution) was given until full clinical recovery. Intensive supportive care given to 60 dogs resulted in significantly improved survival after TBI compared to limited supportive care. With intensive supportive care, we observed high rates of survival in dogs following exposure of up to 7 Gy TBI with complete endogenous hematopoietic recovery (Table). Cytokine treatment consisting of either granulocyte colony stimulating factor (G-CSF) alone or combined G-CSF and fms-like tyrosine kinase 3 (flt-3) ligand (FL), given after TBI did not significantly improve long term survival compared to recipients of intensive supportive care alone, but it significantly decreased the duration of intensive and expensive supportive care. For all cohorts receiving cytokines after TBI, the recovery of ANC was more rapid compared with supportive care alone (p<0.002). Treatment with the combination of G-CSF (10 μg/kg/day) and FL (100 μg/kg/day), starting 2 hours after TBI and continuing until recovery of ANC>1000/μL resulted in more rapid recovery of ANC and platelets compared to G-CSF alone. Follow-up of all surviving dogs >6 months after irradiation showed sustained hematopoiesis and immune reconstitution. These studies show that in this model, hematopoietic stem cells survive doses of TBI up to 7 and 8 Gy without requiring infusion of either autologous or allogeneic hematopoietic stem cells, that intensive supportive care is sufficient to permit reliable survival after 7 Gy TBI, and that the cytokine combination of G-CSF and FL is more effective than G-CSF in promoting rapid recovery of neutrophils and platelets after moderately high dose TBI. The results are relevant for the treatment of victims of terrorist or accidental radiation exposure.TBI dose (Gy)Cytokine after TBIANC RecoveryPlatelet RecoverySurvival / total # of dogs studiedMedian Days after TBI4no26434/45no27523/65G-CSF20446/66no33845/66G-CSF27645/66G-CSF + FL18535/57no55775/67G-CSF24645/57G-CSF + FL18576/68no*n/an/a0/48G-CSF + FL37991/6survival at > day +120