Interleukin 10 prevents dendritic ceil accumulation and vaccination with granulocyte macrophage colony-stimulating factor gene modified tumor cells

A wide variety of human tumors express interleukin10 (IL-10) for reasons poorly understood. We haveanalysed the effect of spontaneous IL-10 expression by amouse tumor (J558L) on its immunparalysing effect.Because cross-priming" of T cells by host antigenpresenting cells for MHC class I restricted tumor antigensis a major pathway for induction of tumor immunity andthat is enhanced by granulocyte-macrophage colony-stimulating factor (GM-CSF), we expressed this cytokinein J558L cells. GM-CSF secreting cells were not

Preclinical evaluation of herpes simplex virus armed with granulocyte-macrophage colony-stimulating factor in pancreatic carcinoma

AIM: To investigate the therapeutic efficacy and mechanisms of action of oncolytic-herpes-simplex-virus encoding granulocyte-macrophage colony-stimulating factor(HSVGM-CSF) in pancreatic carcinoma.METHODS: Tumor blocks were homogenized in a sterile grinder in saline.The homogenate was injected into the right armpit of each mouse.After vaccination,the mice were randomly assigned into four groups: a control group,a high dose HSVGM-CSFgroup [1 × 107plaque forming units(pfu)/tumor],a medium dose HSVGM-CSF group(5 × 106pfu/tumor) and a low dose HSVGM-CSF group(5 × 105pfu/tumor).After initiation of drug administration,body weights and tumor diameters were measured every 3 d.Fifteen days later,after decapitation of the animal by cervical dislocation,each tumor was isolated,weighed and stored in 10% formaldehyde solution.The drug effectiveness was evaluated according to the weight,volume and relative volume change of each tumor.Furthermore,GM-CSF protein levels in serum were assayed by enzyme-linked immunosorbent assays at 1,2,3 and 4 d after injection of HSVGM-CSF.RESULTS: Injection of the recombinant mouse HSV encoding GM-CSF resulted in a significant reduction in tumor growth compared to the control group,and dosedependent effects were observed: the relative tumor proliferation rates of the low dose,medium dose and high dose groups on 15 d after injection were 45.5%,55.2% and 65.5%,respectively.The inhibition rates of the tumor weights of the low,middle,and high dose groups were 41.4%,46.7% and 50.5%,respectively.Furthermore,the production of GM-CSF was significantly increased in the mice infected with HSVGM-CSF.The increase in the GM-CSF level was more pronounced in the high dose group compared to the other two dose groups.CONCLUSION: Our study provides the first evidence that HSVGM-CSFcould inhibit the growth of pancreatic cancer.The enhanced GM-CSF expression might be responsible for the phenomenon.

CONSTRUCTION OF EUKARYOTIC EXPRESSION VECTOR WITH GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR GENE

Objective: To construct the eukaryotic expression vector that express human granulocyte-macrophage colony-stimulating factor (hGM-CSF) gene for making highly express in mammalian cells. Methods: Extract totally RNA from the induced human fetal lung (HFL) cell line. HGM-CSF cDNA was obtained by reverse transcription-polymerase chain reaction (RT-PCR), and then directionally subcloned into the HindIII and EcoRI site on the pcDNA3.1 plasmid, which was controlled by the CMV promoter, to form the recombinant expressing vector pcDNA3.1-GM-CSF. Results: The PCR amplification was identified and the sequence was analyzed, the results showed that hGM-CSF was properly inserted into the vector and the sequence was correct.

Granulocyte-macrophage colony-stimulating factor-transfected bone marrow stromal cells for the treatment of ischemic stroke

Adult, male, Sprague-Dawley rats were injected with granulocyte-macrophage colony-stimulating factor-transfected bone marrow stromal cells （GM-CSF-BMSCs） into the ischemic boundary zone at 24 hours after onset of middle cerebral artery occlusion. Results showed reduced infarct volume, decreased number of apoptotic cells, improved neurological functions, increased angiogenic factor expression, and increased vascular density in the ischemic boundary zone in rats that underwent GM-CSF-BMSCs transplantation compared with the BMSCs group. Experimental findings suggested that GM-CSF-BMSCs could serve as a potential therapeutic strategy for ischemic stroke and are superior to BMSCs alone.

Therapeutic effects of combined suicide gene and granulocyte-macrophage colony stimulating factor gene transfer on erythroleukemia in mice

Adenoviruses harboring E. coli. cytosine deaminase(CD) gene (Ad-CD) and murine granulocyte-macrophage colony stimulating factor (GM-CSF) gene(Ad-GM-CSF) were used for gene transfer in vivo.(C57BL/6 mice were inoculated subeutaneously with FBL-3 erythroleukemia cells and three days later treated withadenovirus injection at the site of tumor inoculation.

EFFECTS OF GRANULOCYTE-MACROPHAGE COLONY STIMULATING FACTOR GENE ENCODED VACCINIA VIRUS VECTOR ON MURINE PULMONARY METASTATIC MELANOMA

A recombinant vaccinia virus expressing murine granulocyte-macrophage colony-stimulating factor (VVGM-CSF) was tested for its antitumor activity.Murine pulmonary metastasis was established by injecting 20×10~5 B16F10 melanoma cells into the tail vein of C57BL/6 mice. Three days after B16F10 inoculation,WGM-CSF or VVTK, a thymidine kinase gene deficient control vaccinia virus, were injected intraperitoneally twice weekly for 2 weeks. Two weeks later, the mice were sacrificed and pulmonary metastasis fool counted.The results demonstrated that VVGM-CSF treatment significantly decreased the number of pulmonary metastasis and prolonged the survival time of tumorbearing mice. Cytotoxic and phagocytic activities of the peritoncal macrophages were found to be markedly elevated in mice treated with WGM-CSF. Nitric oxide released from the macrophages was also found to be increased. These data, together with our other results,strongly demonstrated that continuous secretion of GMCSF and activation of macrophages might pal-tially explain the therapeutic effects of VVGM-CSF on murine pulmonary metastasis.

Role of granulocyte macrophage colony stimulating factor in regeneration of the central nervous system

Traditionally,it has been thought that the mammalian central nervous system（CNS）does not regenerate.Possibly due to the inhibitory extracellular environment post-injury as well as the limited intrinsic characteristics of adult post-mitotic neurons（Smith et al.,2015）.

Granulocyte-colony stimulating factor therapy improves survival in patients with hepatitis B virus-associated acuteon-chronic liver failure

AIM:To evaluate the safety and efficacy of granulocyte-colony stimulating factor(G-CSF) therapy in patients with hepatitis B virus(HBV)-associated acuteon-chronic liver failure(ACLF).METHODS:Fifty-five patients with HBV-associated ACLF were randomized into two groups:the treatment group and the control group.Twenty-seven patients in the treatment group received G-CSF(5 μg/kg per day,six doses) treatment plus standard therapy,and 28 patients in the control group received standard therapy only.The peripheral CD34 + cell count was measured consecutively by flow cytometry.Circulating white blood cell count,biochemical parameters,and other clinical data of these patients were recorded and analyzed.All patients were followed up for a period of 3 mo to evaluate the changes in liver function and survival rate.RESULTS:The peripheral neutrophil and CD34 + cell counts in the G-CSF group increased on day 3 from the onset of therapy,continued to rise on day 7,and remained elevated on day 15 compared to those of the control group.Child-Turcotte-Pugh score of patients in the treatment group was improved on day 30 from the onset of G-CSF therapy,compared to that in the controls(P = 0.041).Model for End-Stage of Liver Disease score of patients in the treatment group was improved on day 7(P = 0.004) and remained high on day 30 from the onset of G-CSF therapy(P < 0.001) compared to that in controls.After 3 mo of follow-up observation,the survival rate in the treatment group(48.1%) was significantly higher than that in the control group(21.4%)(P = 0.0181).CONCLUSION:G-CSF therapy promoted CD34 + cell mobilization in patients with HBV-associated ACLF,and improved the liver function and the survival rate of these patients.

Granulocyte colony-stimulating factor-producing hepatocellular carcinoma with abrupt changes

Granulocyte colony-stimulating factor(G-CSF)-producing tumor is one of the rare types of cancer clinically characterized by an elevated fever and white blood cell(WBC) increment. Although G-CSF producing tumors have been reported in several types of cancer including those of the lungs, cervix and bladder, G-CSF producing hepatocellular carcinoma is extremely rare. Here, we report the case of a rapidly growing and poorly differentiated hepatocellular carcinoma producing G-CSF. The patient showed symptoms of continuous high fever, stomach pain and cough, and high serum WBC counts, C-reactive protein(CRP) and G-CSF levels were found in laboratory tests. After a radical hepatectomy, the patient completely recovered from the above symptoms and inflammatory state. The serum levels of G-CSF were reduced to normal levels after radical surgery. An immunohistochemical analysis revealed the overexpression of G-CSF in the cytoplasm of certain hepatocellular carcinoma(HCC) cell. The patient's serum WBC, CRP and G-CSF levels remained within normal levels in the six months after surgery without recurrence. This is the 9^(th) case report of G-CSF producing hepatocellular carcinoma in English literature. We review the clinical characteristics of the G-CSF producing HCC and discuss a possible treatment strategy.

ANTIGEN ASSOCIATION OF J6-1 CELL MEMBRANE ASSOCIATEDFACTOR RECEPTOR WITH MACROPHAGE COLONYSTIMULATING FACTOR RECEPTOR

Objective: To verify the antigen association of MAF-J6-1 receptor with M-CSFR and to further study the role of M-CSF and its receptor mediated juxtacrine in promoting leukemic cell proliferation. Methods: Monoclonal antibody (McAb) of MAF-J6-1R RE2 and polyclonal antibody (PolyAb) of rhM-CSFR were prepared. The specificity of McAb RE2 to M-CSFR was confirmed by indirect ELISA, cross-neutralizing assay with J6-1 cell colony formation and neutralization test by ELISA. Results: the reactive activity of purified RE2 to M-CSFR was over 1: 16000. The inhibitory activity of M-CSFR and MAF-J6-1R could be blocked by RE2 and anti-M-CSFR antibody. The reactivity of RE2 to M-CSFR could be reduced by M-CSFR. Conclusion: The specificity of RE2 to M-CSFR was confirmed and the antigen association of MAF-J6-1R with M-CSFR was proved. It suggests that M-CSF and its receptor mediated auto-juxtacrine stimulation could be an operative mechanism in either leukemia or nonhematological malignancies.

IMMUNOHISTOCHEMICAL OBSERVATION OF MACROPHAGE COLONY STIMULATING FACTOR AND ITS RECEPTOR IN BREAST CANCER AND HEPATOMA TISSUES

Objective: To study the potential role of cellular macrophage colony-stimulating factor (cM-CSF) and cellular macrophage colony-stimulating factor receptor (cM-CSF-R) with breast cancer and hepatoma and search the way for clinical application. Methods: Frozen surgical specimens from 48 breast cancer patients, including 29 cases of histological grade II and 19 eases of grade III, and 16 hepatoma patients were investigated by Avidin Biotin Complex (ABC) immunohistochemical assay with anti-M-CSF monoclonal antibody (Mab) and anti-M-CSF-R Mab. Pathohistological examination was performed as well. Results: cM-CSF and cM-CSF-R were detected in tested specimens. The expression levels of cM-CSF and cM-CSF-R in grade III group were higher than in grade II group and more higher than control group hyperplasia of breast. Hepatoma tissues also showed higher expression level of cM-CSF and cM-CSF-R than normal adult and fetal liver. Conclusion: Breast cancer and hepatoma tissues presented higher expression levels of cM-CSF and cM-CSF-R than control and expression level might be related with tumor’s process.

Neuroprotective Effect of Granulocyte Colony-stimulating Factor in a Focal Cerebral Ischemic Rat Model with Hyperlipidemia

Granulocyte colony-stimulating factor (G-CSF) has been demonstrated to have neuroprotective effects in rat model with focal cerebral ischemia through anti-apoptotic pathways and by promoting proliferation of neural stem cells. In the present study, we examined the neuroprotective effect of G-CSF in an acute focal cerebral ischemia rat model with lipid metabolism disorder. Eighty male SD rats were randomly divided into normal diet control group (NC group) and high-fat diet group (HFD group) (n = 40 in each). In HFD group, rats were fed on high fat diet to induce atherosclerosis. After 29 days, 4 rats from each group were sacrificed to evaluate the effects of different diets, and the middle cerebral artery occlusion (MCAO) was performed in the rest of the rats. MCAO rats received either G-CSF (50 μg·kg–1·mL–1) or phosphate buffered saline (PBS) injection through the external jugular vein for 5 days, which was followed by 5-bromo-deoxy uridine (BrdU, i.p., 50 mg/kg) injection for another 7 days. To evaluate the effects of G-CSF treatment on neurological function, the modified neurological severity score (mNSS) was calculated. The vascular distribution, ischemic cells proliferation, cell apoptosis and the expression of vascular endothelial growth factor (VEGF) were measured to determine the effects of G-CSF treatment. Our results showed that G-CSF-treated rats had a lower mNSS than PBS-treated rats in both NC group and HFD group. G-CSF injection promoted endothelial cell proliferation and vascular regeneration, and inhibited cell apoptosis. The serum and tissue levels of VEGF were significantly increased after G-CSF treatment. It is concluded that G-CSF exerts its neuroprotective effect in focal cerebral ischemia rats with hyperlipidemia by enhancing angiogenesis, promoting cells proliferation, decreasing cell apoptosis, and increasing local VEGF expression.

CO-EXPRESSION OF MACROPHAGE COLONY-STIMULATING FACTOR WITH ITS RECEPTOR IN HUMAN HEPATOMA CELLS AND ITS POTENTIAL ROLES

Objective: To investigate the potential role of macrophage colony-stimulating factor (M-CSF) and macrophage colony-stimulating factor receptor (M-CSF-R) on the growth of human hepatoma cells. Methods: Specimens of different origin, including tissues of human hepatocellular carcinoma (HCC), human fetal liver (FL) and normal liver (NL), the hepatoma cell lines, as well as the peripheral blood mononuclear cells (PBMC) from patients with HCC or liver metastatic tumor (LMT), were used to detect the expression levels of M-CSF and M-CSF-R by ABC immunohistochemistry staining and reverse transcription polymerase chain reaction methods the expression levels of M-CSF and M-CSF-R. Influence of monoclonal antibody against M-CSF (B5) or M-CSF-R (RE2) on proliferation ability of hepatoma cell linesin vitro was also studied. Results: The results showed that hepatoma tissues produced elevated levels of both M-CSF and M-CSF-R compared with those of fetal liver (P<0.001). The M-CSF/M-CSF-R expression levels of PBMC from hepatoma patients were higher than those of LMT patients (P<0.01,P<0.05) and the normal people (P<0.001). The hepatoma cell lines showed strong positive for M-CSF and M-CSF-R production. Both B5 and RE2 displayed a dose-dependent inhibitory effect on the growth and proliferation of hepatoma cells. Conclusion: The study indicates a co-expression model for M-CSF-R in hepatoma cells, suggesting an involvement of M-CSF/M-CSF-R in growth signaling of those malignant cells. The M-CSF/M-CSF-R seems to function through an autonomy mechanism in human hepatoma.

Mobilization of Peripheral Blood Stem Cells Using Regimen Combining Docetaxel with Granulocyte Colony-stimulating Factor in Breast Cancer Patients

Objective：To evaluate the effectiveness and safety of the mobilization of peripheral blood hematopoietic stem cells by combining docetaxel with granulocyte colony-stimulating factor（G-CSF） in breast cancer patients.Methods：A total of 57 breast cancer patients were treated with docetaxel 120 mg/m2.When the white blood cell（WBC） count decreased to 1.0×109/L,patients were given G-CSF 5-g/kg daily by subcutaneous injection until the end of apheresis.Peripheral blood mononuclear cells（MNC） were isolated by Cobe Spectra Apheresis System.The percentage of CD34＋ cell was assayed by flow cytometry.Results：At a median 6 of days（range 3-8） after the administration of docetaxel,the median WBC count decreased to 1.08×109/L（range 0.20-2.31）.The median duration of G-CSF mobilization was 3 days（range 2-7）.The MNC collection was conducted 8-12 days（median 10 days） after docetaxel treatment.The median MNC was 5.35×108/kg（range 0.59-14.07）,the median CD34＋ cell count was 2.43×106/kg（range 0.16-16.69）.The CD34＋ cell count was higher than 1.00×106/kg in 47 of 57 cases（82.46%） and higher than 2.00×106/kg in 36 cases（63.16%）.The CD34＋ cell count was higher than 2.00×106/kg in 27 collections（23.68%）.The MNC count and the CD34＋ cell count were correlated with the bottom of WBC after docetaxel chemotherapy（r=0.364,0.502,P=0.005,0.000）.The CD34＋ cell count was correlated with the MNC count（r=0.597,P=0.000）.The mobilization and apheresis were well tolerated in all patients.Mild perioral numbness and numbness of hand or feet were observed in 3 cases.No serious adverse events were reported.Conclusion：Mobilization of peripheral blood hematopoietic stem cell by combining docetaxel with G-CSF was effective and safety in breast cancer patients.

Application of pegylated recombinant human granulocyte colony-stimulating factor(PEG-rhG-CSF) for the prevention of neutropenia in triple negative breast cancer patients older than 65 years during adjuvant chemotherapy

Objective The aim of this study was to compare the efficacy and safety of pegylated recombinant human granulocyte colony-stimulating factor(PEG-rhG-CSF)and recombinant human granulocyte colonystimulating factor(rhG-CSF)for the prevention of neutropenia in elderly breast cancer patients during adjuvant chemotherapy.Methods A total of 45 oncology inpatients with breast cancer,who received adjuvant chemotherapy and were older than 65 years from May 2017 to October 2018 in the General Hospital of the Northern Theater of the Chinese people’s Liberation Army,were included.Epirubivin Cyclophoshamide-Docetaxel(EC-T)sequential adjuvant chemotherapy was chosen.Forty-five patients were randomly divided into two groups;25 patients in the treatment group were treated with PEG-rhG-CSF and 20 patients in the control group were not treated with PEG-rhG-CSF,but only rhG-CSF.The experimental group was treated with the PEG-rhG-CSF at the end of chemotherapy for 24–48 h,with a 6 mg subcutaneous injection once per chemotherapy cycle.In the control group,rhG-CSF was administered after 48 h of chemotherapy,with a 100μg subcutaneous injection,1/d,d 1–7.The dosage could be increased step by step with the exacerbation of neutropenia.The primary aims of this study was to discover the incidence of leukopenia,neutropenia,neutrophilic fever,and adverse reactions in the two groups.Results The incidence of neutropenia,neutrophilic fever and adverse reactions decreased in the treatment group compared to the control group,but no significant difference existed between two groups(P>0.05).Patients in treatment group had a lower,but not statistically significant,incidence of adverse reactions(P>0.05).Conclusion Applying PEG-rhG-CSF could be effective in preventing neutropenia in elderly patients with postoperative adjuvant chemotherapy to treat breast cancer.It may effectively control the occurrence of neutropenia after chemotherapy and reduce the chance of infection.The incidence of side effects,such as fever and bone pain,was low.The adverse drug reactions were well tolerated by patients,which could ensure the smooth progress of chemotherapy.

Granulocyte colony-stimulating factor increases extracellular glutamic acid uptake and suppresses free radicals in an experimental model of amyotrophic lateral sclerosis

Excitatory amino acid toxicity and free radical damage play important roles in amyotrophic lateral sclerosis. Granulocyte colony-stimulating factor （G-CSF） protects nerve cells exposed to high-concentrations of glutamic acid, suggesting positive effects in the treatment of amyotrophic lateral sclerosis. The present study induced in vitro motor neuron injury using glutamic acid excitotoxicity, and the biochemical effects of G-CSF on glutamic acid concentration were determined. In addition, the effects of G-CSF on superoxide dismutase, glutathione peroxidase activity in motor neurons, and malondialdehyde and nitric oxide contents were analyzed. Immunohistochemistry was performed to measure neuronal survival. Results revealed that G-CSF significantly suppressed free radical activity, inhibited excitotoxicity, and reduced apoptosis and loss of motor neurons in the anterior horn of the spinal cord.

Capillary Zone Electrophoresis Investigation of Interactions between Granulocyte-colony Stimulating Factor and Dextran Sulfate/Carrageenan Oligosaccharide

The interactions between granulocyte-colony stimulating factor (G-CSF) and dextran sulfate / κ-carrageenan oligosaccharide were studied by capillary zone electrophoresis. Dextran sulfate could strongly interact with G-CSF and the complex was detected. The binding constant and stoichiometry were determined to be 1.2×106 (mol/L)-1 and 3:1, respectively. However, the interaction between κ-carrageenan oligosaccharide and G-CSF was not found.

DETERMINATION OF SERUM SOLUBLE MACROPHAGE COLONY-STIMULATING FACTOR RECEPTOR LEVELS IN PATIENTS WITH HEMATOLOGICAL DISEASES

Objective: To investigate the serum levels of soluble macrophage colony-stimulating factor receptor (M-CSFsR) in normal subjects and patients with hematological diseases and its clinical implications in hematological diseases. Methods: The concentration of M-CSFsR was determined by ELISA. The serum M-CSFsR was identified and characterized by immunoprecipitation and Western blotting. Results: The mean serum level of M-CSFsR of 123 normal individuals was 0.48 ng/ml ± 0.41 ng/ml. Immunoprecipitation and Western blotting assay revealed a ～ 90kD band of serum M-CSFsR. The mean serum M-CSFsR level of 60 patients with acute lymphoblastic leukemia (ALL), 36 patients with acute myeloblastic leukemia (AML), 13 patients with myelodysplastic syndrome (MDS) and 42 patients with aplastic anemia (AA) .were 0.22 ng/ml±0.23 ng/ml, 0.17 ng/ml±0.16 ng/ml, 0.19 ng/ml±0.16 ng/ml and 0.23 ng/ml±0.21 ng/ml, respectively, which were significantly lower than that of normal subjects (P=0.002 ,P<0.0001,P<0.0001 andP<0.0001). The mean serum M-CSFsR level of 51 idiopathic thrombocytopenic purpura (ITP) patients was significantly higher than that of normal subjects (2.05 ng/ml±2.75 ng/ml,P<0.0001). Conclusion: The serum M-CSFsR levels of patients with ALL, AML, MDS and AA were significantly lower, while the level of patients with ITP was significantly higher than that of normal individuals. Patients with severe ITP (platelet count<30×l09/L) had the highest M-CSFsR level. It suggested that the abnormal levels of serum M-CSFsR may associate with some hematological diseases and may contribute to the pathological process.

ENHANCEMENT OF NIH3T3 CELL PROLIFERATION BY EXPRESSING MACROPHAGE COLONY STIMULATING FACTOR IN NUCLEI

Objective: To explore the effects of nuclear M-CSF on the process of tumorigenesis. Methods: Functional part of M-CSF cDNA was inserted into an eukaryotic expression plasmid pCMV/myc/nuc, which can add three NLS to the C-terminal of the expressed protein and direct the protein into the cell nuclei. The constructed plasmid was transferred into NIH3T3 cells and the cell clones were selected by G-418 selection. Cell clones stable expressing target protein were identified by RT-PCR, ABC immunohistochemistry assayand Western blot. Cell growth kinetics analyses throughgrowth curves, cell doubling time, MTT test and anti-sense oligodeoxynucleotide (ASODN) inhibiting cell growth testwere performed to identify cells proliferation potential.Results: The transfected cells showed elevated proliferation potential over the control cells. Conclusion: Abnormalappearance of M-CSF in nucleus could enhance cellproliferation, which suggests that cytokine isoforms within cell nucleus might play transcription factor-like role.

Administration of granulocyte colony stimulating factor after liver transplantation leads to an increased incidence and severity of ischemic biliary lesions in the rat model

AIM： Recently it has been reported that granulocyte colony stimulating factor （G-CSF） can induce hypercoagulability in healthy bone marrow donors. It is conceivable that the induction of a prothrombotic state in a recipient of an organ graft with already impaired perfusion might cause further deterioration in the transplanted organ. This study evaluated whether G-CSF treatment worsens liver perfusion following liver transplantation in the rat model. METHODS： A non-arterialized rat liver transplantation model was employed to evaluate the effect of G-CSF treatment on the liver in a syngeneic and allogeneic strain combination. Study outcomes included survival time and liver damage as investigated by liver enzymes and liver histology. Observation times were 1 d, 1 wk and 12 wk. RESULTS： Rats treated with G-CSF had increased incidence and severity of biliary damage following liver transplantation. In these animals, hepatocellular necrosis was accentuated in the centrilobular region. These lesions are indicative of impaired perfusion in G-CSF treated animals. CONCLUSION： G-CSF should be used with caution in recipients of liver transplantation, as treatment might enhance preexisting, undetected perfusion problems and ultimately lead to ischemia induced biliary complications .