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N Nicola

Publications and source records attributed to N Nicola.

At least 19 recordsLinked to original sources
PubMed1997

Recombinant soluble interleukin-11 (IL-11) receptor alpha-chain can act as an IL-11 antagonist.

We have expressed a soluble N-glycosylated form of the murine interleukin-11 (IL-11) receptor alpha-chain (sIL-11R) and examined signaling in cells expressing the gp130 molecule. In the presence of gp130 but not the transmembrane IL-11R, the sIL-11R mediated IL-11-dependent differentiation of M1 leukemic cells and proliferation in Ba/F3 cells. Early intracellular events stimulated by the sIL-11R including phosphorylation of gp130, STAT 3, and SHP-2 were similar to signaling through the transmembrane IL-11R. IL-11 bound to sIL-11R with low affinity (kd 10 to 50 nmol/L). Binding of sIL-11R to gp130 was IL-11 dependent with intermediate affinity (kd 1.5 to 3.0 nmol/L). However, the concentration of IL-11 required for signaling through the sIL-11R was 10- to 20-fold greater than that required for cells expressing the transmembrane IL-11R and gp130 in the absence of sIL-11R. Furthermore, the sIL-11R was capable of antagonizing the activity of IL-11 when tested on cells expressing the transmembrane IL-11R and gp130. We propose that the observed IL-11 antagonism by the sIL-11R may depend on limiting numbers of gp130 molecules on cells already expressing the transmembrane IL-11R.

Amino Acid Sequence↗
PubMed1996

The human IL-11 receptor requires gp130 for signalling: demonstration by molecular cloning of the receptor.

We describe the molecular cloning of a cDNA for the alpha chain of the human IL-11 receptor (IL-11R alpha) and demonstrate the requirement of either the human or mouse gp130 molecule for signalling. cDNA clones encoding IL-11R alpha were isolated from a bone marrow cDNA library using a fragment from the murine IL-11R alpha as a probe. The human receptor was predicted to consist of 422 amino acids and was found to share 84% identity with the murine protein. In the extra-cellular region it exhibited a single hemopoietin domain with conserved cysteine residues and WSTWS motif. The transmembrane region was followed by a short cytoplasmic tail which did not contain a tyrosine kinase domain. Interaction of the human IL-11R alpha with murine gp130 was demonstrated: expression of the human IL-11R alpha in murine M1 cells which constitutively express murine gp130 (and murine LIF receptor), resulted in the generation of specific high-affinity binding sites for IL-11 (Kd = 250 pM). In addition, expression of the human IL-11R alpha in these cells permitted the induction of macrophage differentiation in response to IL-11. These results suggested that the human IL-11R alpha chain was able to form a functional receptor complex in association with murine gp130. The requirement of gp130 for signalling was confirmed by expression of the human IL-11R alpha in Ba/F3 cells. BaF3 cells that expressed the human IL-11R alpha alone showed binding of radiolabelled IL-11 but no proliferative response. Introduction of human gp130 into these cells resulted in high-affinity IL-11 binding sites and IL-11 dependent cellular proliferation. Thus these results demonstrated the absolute requirement of gp130 for signalling.

Amino Acid Sequence↗
PubMed1995

Differential regulation of macrophage differentiation in response to leukemia inhibitory factor/oncostatin-M/interleukin-6: the effect of enforced expression of the SCL transcription factor.

The physiologic program of macrophage differentiation normally proceeds in a coordinated manner in response to several different growth factors. Although the utilization of common receptor subunits may explain in part overlapping biologic functions, mechanisms by which unique actions are mediated remain obscure. We examined growth factor-induced macrophage differentiation in M1 leukemia cells that simultaneously display receptors for interleukin-6 (IL-6), leukemia inhibitory factor (LIF) and Oncostatin-M (OSM). Differentiation induced by all three factors was associated with decreased expression of transcription factors myb and SCL, increased expression of macrophage markers, and suppression of proliferation. Cell lines were established in which SCL expression was enforced. In the absence of growth factors, cells were indistinguishable from parental cells. However, LIF (or OSM)-induced macrophage differentiation was perturbed; there was failure to undergo morphologic differentiation, disturbed expression of lysozyme and Mac1 alpha, and failure to suppress proliferation. Surprisingly the perturbation of macrophage differentiation did not apply to induced expression of macrophage colony-stimulating factor (M-CSF) or granulocyte colony stimulating factor (G-CSF) receptors. This dissociation of elements normally coordinated in a macrophage differentiation program applied at a clonal level. There was no disturbance of IL-6-induced macrophage differentiation. These data directly implicate SCL in components of the macrophage differentiation program (suggesting that LIF receptor/gp130 heterodimers utilize an SCL-inhibitable pathway while gp130 homodimers do not) and demonstrate differential-regulation of components of the mature macrophage phenotype.

Animals↗
PubMed1994

The SCL protein displays cell-specific heterogeneity in size.

SCL protein production was examined in a variety of hemopoietic cell lines by immunoblotting using specific polyclonal antisera. SCL protein was detected in erythroid, megakaryocyte, mast and early myeloid cell lines, as well as in several lymphoid leukemia cell lines which are known to harbor SCL gene rearrangements. In most cell lines, proteins of molecular weight 49 and 44 kDa were found, however two myeloid cell lines expressed only lower molecular weight species of 24 and 22 kDa. This size discrepancy appeared to be due to cell-specific translational regulation, since overexpression of a retrovirally transfected SCL gene yielded the higher molecular weight forms in most cell lines (GP+E-86, AT2.5, M1) but only the 22 kDa form in the myeloid cell line, WEHI-3B/D+. Overexpression of full-length SCL protein in the lymphoid cell lines, SupT1 and Raji, did not alter cell phenotype and there was no evidence for autoregulation of SCL transcription. The restricted pattern of SCL protein synthesis is consistent with the restricted expression of SCL mRNA documented previously. In addition, the present results indicate that SCL protein size was determined by regulation of translation in a cell-specific manner.

Amino Acid Sequence↗
PubMed1992

Bone marrow cells from A/J mice do not proliferate in interleukin-3 but express normal numbers of interleukin-3 receptors.

Haemopoietic cells from A/J mice do not form colonies (proliferate) in response to interleukin-3 (multi-CSF, IL-3). We have examined different populations of cells from A/J mice and shown that, despite their failure to proliferate in response to IL-3, cells from bone marrow, spleen and the peritoneum all bound 125I-labelled IL-3. A wide variety of cell types bound IL-3 as determined by autoradiography, including promyelocytes, myelocytes, metamyelocytes, polymorphs, promonocytes, monocytes, eosinophils and lymphocytes, but not nucleated erythroid cells, and the proportion of each cell type binding label was similar when cells from A/J mice were compared with those of C57B1/6 and Balb/c mice. Bone marrow cells from A/J mice internalized interleukin-3 with normal kinetics and mRNA extracted from these cells contains the same species of IL-3 receptor and IL-3 receptor-like mRNAs as are found in the other strains. Collectively the data suggest that the failure of haemopoietic cells from A/J mice to proliferate in response to IL-3 is related to a selective defect in signalling to proliferation specific genes. This defect is apparently not related to internalization or processing of the IL-3/IL-3-receptor complex, but may be due to failure to activate appropriate accessory molecules in the cell.

Animals↗
PubMed1992

Leukemia inhibitory factor levels are elevated in septic shock and various inflammatory body fluids.

Leukemia inhibitory factor (LIF) has many biological actions which parallel those of IL-1, IL-6 and tumor necrosis factor-alpha, but its role in the pathogenesis of human disease is unknown. A specific radioreceptor competition assay capable of detecting LIF at concentrations above 1 ng/ml (45 pM) was developed. To identify disease states in which LIF might be involved, a cross-sectional survey of serum and body fluids from approximately 1,500 subjects with a variety of diseases was performed using the LIF radioreceptor competition assay. Serum LIF concentrations were transiently elevated (2-200 ng/ml) in six subjects with meningococcal or Gram-negative septic shock, and in a subject with idiopathic fulminant hepatic failure. Moderately elevated LIF concentrations (> 10 ng/ml) were detected in cerebrospinal fluid from subjects with bacterial meningitis, in effusions associated with pneumonia and peritonitis, and in amniotic fluid from a woman with chorioamnionitis. Low LIF concentrations (1-10 ng/ml) were present in synovial fluid from subjects with inflammatory arthritis, amniotic fluid from women in labor, and some reactive, chronic inflammatory and malignant effusions and cyst fluids, but rarely in transudates. These initial findings suggest that LIF might be involved in the pathogenesis of inflammation and septic shock.

Amniotic Fluid↗
PubMed1990

Granulocyte-macrophage colony stimulating factor from human lymphocytes. The effect of glycosylation on receptor binding and biological activity.

Native human granulocyte-macrophage colony stimulating factor (hGM-CSF) has previously been purified using methods which typically required several sequential chromatographic steps and only yielded small amounts of hGM-CSF. We have purified and characterized hGM-CSF using monoclonal antibodies raised against bacterially synthesized hGM-CSF. Activated donor T-lymphocytes grown in interleukin-2 and then reactivated with phytohemagglutinin produce several forms of hGM-CSF which can be purified using immunoaffinity absorption followed by reversed phase high performance liquid chromatography. The purified hGM-CSF consisted of at least nine species ranging in molecular weight (Mr) from 14,500 to 32,000. The higher Mr forms contained one or two N-linked carbohydrate moieties and were more acidic by two-dimensional Western blot analysis, consistent with increasing sialation. N-terminal sequence analysis of high and low molecular weight hGM-CSF fractions corresponded to that predicted by the cDNA sequence. Using the AML 193 [3H]thymidine incorporation assay the specific activity of the heavily glycosylated hGM-CSF was 1 x 10(8) units/mg compared with 6 x 10(8) units/mg for the non-glycosylated hGM-CSF produced by Escherichia coli. The different hGM-CSF forms induced neutrophil superoxide anion production by a variable amount depending on the extent of N-linked glycosylation. Receptor binding studies demonstrated lower receptor affinity for the heavily glycosylated form (KD = 820 pM) compared to less heavily glycosylated (KD = 78 pM) and non-glycosylated hGM-CSF produced by E. coli (KD = 30 pM). These differences are due to differences in the kinetic association rate.

Binding, Competitive↗
PubMed1988

A nondenaturing vertical isoelectric focusing polyacrylamide slab gel system suitable for silver staining and electrophoretic blotting.

We have devised a nondenaturing vertical isoelectric focusing (IEF)-polyacrylamide gel electrophoresis (PAGE) system which is amenable to silver staining and electroblotting. Apart from being accessible, inexpensive, and simple to use, this new methodology overcomes problems inherent in current IEF methods, for example, pH gradient drift, nonuniform cooling, restricted sample volume, and inability to perform electroblotting. Two photopolymerization gel formulas were derived: a 5% acrylamide formula using bisacrylamide (Bis) as the crosslinker and a 6% acrylamide formula using diallyltartdiamide (DATD) as the crosslinker. The 5% acrylamide Bis gel gave excellent resolution and separation of proteins whereas the 6% acrylamide DATD gel expanded slightly during silver staining, resulting in mild band distortions. At least 80 ng of protein per band could be detected by the silver staining protocol devised. Both the DATD and the Bis gels were suitable for electroblot transfer. Parameters to ensure the optimum conditions for reproducible, high resolution vertical IEF-PAGE are described. IEF-PAGE silver staining and electroblotting procedures and silver staining of the nitrocellulose electroblot procedures are also described. The advantages of this methodology over previously published methods are discussed.

Animals↗
PubMed1988

Congenital anaplastic astrocytoma with favorable prognosis. Case report.

A large intracranial tumor that caused macrocrania leading to dystocia was demonstrated by prenatal ultrasound examination. After birth, computerized tomography (CT) confirmed the presence of a giant supratentorial tumor with a large cyst. When the infant was 20 days old, the tumor was radically extirpated. Neuropathological examination revealed an astrocytoma with focal signs of anaplasia showing a macrocyst as well as multiple microcysts resulting from hemorrhages into the tumor. Although no adjuvant radio- or chemotherapy was administered, the child had nearly normal psychomotor development without clinical or CT evidence of tumor recurrence, and is now 3 years old.

Astrocytoma↗
PubMed1987

The influence of magnetic resonance tomography on diagnosis and therapy in patients with intracranial manifestation of neurofibromatosis (Recklinghausen disease).

Recent research into the natural course of neurofibromatosis has revealed an outstandingly high proportion of central nervous system malignancies as well as cancers of various other organs. Due to the lack of ionizing radiation, the extraordinary reconstruction in the frontal and parasaggital planes as well as the diagnosis of intracanalicular acoustic neurinomas and intraorbital tumors, magnetic resonance tomography (MRT) is indicated for control of patients with neurofibromatosis.

Adolescent↗
PubMed1987

Vertebral hemangioma: retrograde embolization-stabilization with methyl methacrylate.

A new method, intraoperative retrograde embolization with a methyl methacrylate polymer injected into a vertebral hemangioma, is described. This method achieves complete intraoperative hemostasis and postoperative stabilization. No further stabilization procedures and radiation therapy are necessary. Preoperative selective angiography with embolization and consecutive laminectomy are required for this method.

Adult↗
PubMed1986

Osteoclastomas of the petrous bone.

Two cases of osteoclastoma of the petrous bone are presented that were clinically taken for tumors of the glomus jugulare. The petrous bone is a very uncommon location for such tumors, and only six cases have been reported in the English literature. The histopathological features as well as the clinical course are described, and the literature is critically reviewed.

Female↗
PubMed1986

[Computerized tomography of intracranial tuberculous lesions. 2 case reports].

In contrast to the numerous publications on supratentorially located tuberculomas, reports on infratentorial tuberculomas, demonstrated by computed tomography, are relatively few in number. Although nowadays precise localization has become possible via computed tomography, a tuberculoma cannot be identified unequivocally by computed tomography. The appearance of tuberculous lesions in CT depends on the extent the lesion has advanced at the time of the investigation and whether or not tuberculostatics have already been administered. In the posterior cranial fossa, brain stem tuberculomas must additionally be distinguished from cerebellar tuberculomas and tuberculous brain abscess from solid tuberculomas. The problem of tuberculous lesions in computed tomography is discussed with reference to a left frontotemporal tuberculoma and a vermis tuberculoma demonstrated by computed tomography and removed surgically.

Adult↗
PubMed1984

Mononuclear cell-mediated enhancement of granulocyte function in man.

Human monocyte-enriched mononuclear cells (MNC) (greater than 95% monocytes) powerfully stimulated the antibody-dependent killing of tumor cells by purified human neutrophils (NE) or eosinophils (EO). The enhancement was observed when the mononuclear cell to granulocyte ratio was as low as 1:100. Media conditioned by MNC also stimulated antibody-dependent killing by NE and EO as well as the uptake and killing of Candida albicans by NE. There was a heterogeneity amongst individuals in the capacity of their MNC to elaborate this factor, and approximately 15% of individuals did not produce detectable factor. Different factors in the MNC supernatant were involved in NE and EO activation. The EO-activating factor (AF) had a m.w. of approximately 27,000 and migrated as a single band on phenyl-Sepharose chromatography. The NE-AF had a m.w. of 22,000 and migrated as two distinct bands on phenyl-Sepharose chromatography. EO-colony-stimulating factor (CSF) co-purified with EO-AF, and granulocyte-macrophage-CSF co-purified with both bands of NE-AF. It is concluded that MNC elaborate CSF-like molecules that powerfully stimulate human granulocyte function.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1983

[Multiple meningiomas at various levels of the cerebromedullary axis].

Two cases, each with two meningiomas are reported. Their peculiarity consists in the fact that the different tumours developed at different times and in widely separated locations in the supratentorial and spinal regions. The possibility of dissemination via the cerebrospinal fluid and of a multifocal origin is discussed, as well as the grade of malignancy.

Aged↗
PubMed1983

Eosinophil activation by colony-stimulating factor in man: metabolic effects and analysis by flow cytometry.

Substantial increases in the killing capacity of human eosinophils after in vitro incubation with human placental conditioned medium (HPCM), a standard source of colony-stimulating factor (CSF), have recently been described. In this article, the interaction between HPCM and purified human eosinophils is analyzed by flow cytometry and by effects on iodination, superoxide production, and protein synthesis. HPCM increased the intensity of natural eosinophil autofluorescence (aFlu) (460 nm) after the absorption of ultraviolet light (360 nm) in a manner that was both time and dose dependent. Measured in arbitrary units, eosinophil aFlu was 72 +/- 7.3 (arithmetic mean +/- SEM) and 121 +/- 3.2 after 18-hr incubations in the absence or presence of HPCM, respectively. The activity in HPCM responsible for these changes cochromatographed on Ultrogel AcA44 columns with CSF and with the less hydrophobic variant of CSF (CSF-alpha) on phenyl Sepharose. Mouse spleen, but not mouse lung, conditioned medium was also active on human eosinophils in this assay. Both CSF-alpha and mouse spleen conditioned medium also contain eosinophil colony-stimulating activity (CSA), whereas inactive CSFs with no effect on mature eosinophils, CSF-beta, and mouse lung conditioned medium also lack eosinophil CSA. CSF-alpha stimulated superoxide production of resting eosinophils (from 0.03 +/- 0.03 to 0.47 +/- 0.08 nmole cytochrome-c reduced/10(5) eosinophils) and of eosinophils incubated with preopsonized zymosan (from 0.15 +/- 0.06 to 0.73 +/- 0.07). It also stimulated iodination by resting eosinophils (from 0.76 +/- 0.16 to 2.60 +/- 0.72 nmoles l/10(7) eosinophils/hr) and of eosinophils incubated with preopsonized zymosan (from 7.52 +/- 2.08 to 29.8 +/- 1.32). In contrast, CSF-beta was inactive in these assays. CSF-alpha also stimulated, between 2- and 15-fold, the new protein synthesis of eosinophils. Thus, substances that stimulate the differentiation of progenitor cells into eosinophils also interact with peripheral mature eosinophils, and the activation of postmitotic cells may be a physiologic role of CSF-like molecules.

Cell Separation↗