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L Fumagalli

Publications and source records attributed to L Fumagalli.

At least 73 records · Page 4Linked to original sources
PubMed1994

Serum levels of insulin-like growth factor-I in operable breast cancer in relation to the main prognostic variables and their perioperative changes in relation to those of prolactin.

AIMS AND BACKGROUND: In addition to estrogens, prolactin (PRL) and IGF-I have also appeared to stimulate breast cancer growth. The present study was performed to evaluate IGF-I blood levels in operable breast cancer in relation to PRL values and the main prognostic variables. METHODS: The study included 40 patients, clinical stage T1-3NO-2MO. Venous blood samples were collected before and 7 days after surgery. PRL and IGF-I were measured by radioimmunoassay. The control group consisted of 50 healthy women. RESULTS: Mean serum levels of IGF-I were significantly higher in patients than in controls, without any apparent relation to the main prognostic variables, including estrogen receptor and node status. Surgery-induced hyperprolactinemia occurred in 22/40 patients. IGF-I mean concentrations observed in the postoperative period in patients with surgery-induced hyperprolactinemia were significantly lower than those seen in patients showing no postoperative PRL rise. CONCLUSIONS: The study showed that operable breast cancer may be associated with abnormally high levels of tumor growth factor IGF-I, and that surgery was followed by an IGF-I decline only in patients who showed surgery-induced hyperprolactinemia. Our previous studies have shown that postoperative hyperprolactinemia is a favorable prognostic factors for operable breast cancer. The present study, by showing that a postoperative PRL rise is associated with a fall in IGF-I, would suggest that surgery-induced hyperprolactinemia may determine a lower tumor relapse rate by determining a diminished secretion of breast tumor growth factor IGF-I.

Adult↗
PubMed1994

Immunohistochemical localization of serine-protease inhibitors in the human placenta.

Proteases and their inhibitors play a pivotal role in developmental and differentiative processes. In the present report we investigated the immunohistochemical localization of alpha 1-antitrypsin, alpha 1-antichymotrypsin and inter-alpha-trypsin inhibitor in first trimester as well as in term human placentas. For this purpose polyclonal antibodies against these serine-protease inhibitors were used. All inhibitors were expressed in the villous syncytiotrophoblast of first and last trimester placentas. Placental fibrinoid was positively stained for alpha 1-antitrypsin and inter-alpha-trypsin inhibitor throughout gestation. alpha 1-Antitrypsin and alpha 1-antichymotrypsin showed a strong immunostaining in the Hofbauer cells (first trimester and full term placentas). Extravillous cytotrophoblast was negative for the three protease inhibitors throughout gestation. The presence of the three inhibitors in the syncytiotrophoblast suggests a role in coagulative, invasive and immunomodulatory processes. Fibrinoid, staining for alpha 1-antitrypsin and inter-alpha-trypsin inhibitor, could also have an important immunoprotective function. The presence of protease inhibitors in the Hofbauer cells suggests an involvement of these cells in villous remodelling and differentiative processes.

Alpha-Globulins↗
PubMed1994

Beta 2 integrin-dependent protein tyrosine phosphorylation and activation of the FGR protein tyrosine kinase in human neutrophils.

Stimulation of adherent human neutrophils (PMN) with tumor necrosis factor (TNF) triggers protein tyrosine phosphorylation (Fuortes, M., W. W. Jin, and C. Nathan. 1993. J. Cell Biol. 120:777-784). We investigated the dependence of this response on beta 2 integrins by using PMN isolated from a leukocyte adhesion deficiency (LAD) patient, which do not express beta 2 integrins, and by plating PMN on surface bound anti-beta 2 (CD18) antibodies. Protein tyrosine phosphorylation increased in PMN plated on fibrinogen and this phosphorylation was enhanced by TNF. Triggering of protein tyrosine phosphorylation did not occur in LAD PMN plated on fibrinogen either in the absence or the presence of TNF. Surface bound anti-CD18, but not isotype-matched anti-Class I major histocompatibility complex (MHC) antigens, antibodies triggered tyrosine phosphorylation in normal, but not in LAD PMN. As the major tyrosine phosphorylated proteins we found in our assay conditions migrated with an apparent molecular mass of 56-60 kD, we investigated whether beta 2 integrins are implicated in activation of members of the src family of intracellular protein-tyrosine kinases. We found that the fgr protein-tyrosine kinase (p58fgr) activity, and its extent of phosphorylation in tyrosine, in PMN adherent to fibrinogen, was enhanced by TNF. Activation of p58fgr in response to TNF was evident within 10 min of treatment and increased with times up to 30 min. Also other activators of beta 2 integrins such as phorbol-12-myristate 13-acetate (PMA), and formyl methionyl-leucyl-phenylalanine (FMLP), induced activation of p58fgr kinase activity. Activation of p58fgr kinase activity, and phosphorylation in tyrosine, did not occur in PMN of a LAD patient in response to TNF. Soluble anti-CD18, but not anti-Class I MHC antigens, antibodies inhibited activation of p58fgr kinase activity in PMN adherent to fibrinogen in response to TNF, PMA, and FMLP. These findings demonstrate that, in PMN, beta 2 integrins are implicated in triggering of protein tyrosine phosphorylation, and establish a link between beta 2 integrin-dependent adhesion and the protein tyrosine kinase fgr in cell signaling.

Amino Acid Sequence↗
PubMed1993

Receptor-mediated endocytosis of alpha 2 macroglobulin by a glioma cell line.

Previous experiments have shown that human neoplastic and embryonic glial cell lines synthesize and secrete in culture, alpha 2 macroglobulin (alpha 2M), a broad spectrum proteinase inhibitor present in serum and extracellular fluids. The present study was aimed to investigate the presence of alpha 2M receptors on glial cell membrane, since several non-neural cell types producing alpha 2M also express alpha 2M receptors. By flow cytometric analysis, immunofluorescence and immunoelectronmicroscopy techniques we demonstrate an alpha 2M receptor-related immunoreactivity on the plasma membrane of a human glioma cell line. Ultrastructural experiments reveal a close colocalization of immunoreactivities for alpha 2M and its receptor in clathrin-coated pits and vesicles, structures typically involved in receptor-mediated endocytic pathways.

Endocytosis↗
PubMed1993

Immunogold ultrastructural localization of calpastatin, the calpain inhibitor, in rabbit skeletal muscle.

The ultrastructural localization of calpastatin, the endogenous inhibitor of the neutral calcium-dependent proteases (calpains), was investigated in rabbit skeletal muscle fibers using a polyclonal antibody against the 34 kDa form of the inhibitor isolated from rabbit. Quantitative studies by pre- and postembedding immunogold techniques revealed that the distribution pattern of the specific immunoreactivity included: 1) the sarcolemma with the adjacent cytoplasm (about 1 micron wide); 2) the myofibrils; 3) the mitochondria and 4) the nuclei (condensed as well as extended chromatin). Other cell substructures, such as lysosomes and the intermyofibrillar cytoplasm, were substantially devoid of immunoreactivity. Furthermore, in accordance to previous light microscope immunohistochemical experiments, an extracellular (endomysial) localization of specific immunoreactivity was confirmed. These results favour the view, which is also supported by a series of biochemical evidences, that calpastatin in rabbit skeletal muscle is present in cell structures also containing calpains and/or their putative substrates. The above multiple patterns of distribution also suggest that the muscular calpain-calpastatin system in skeletal muscle fibers may play different physiological roles in the various subcellular compartments.

Animals↗
PubMed1992

Calpain inhibitor in rabbit skeletal muscle: an immunochemical and histochemical study.

Calpastatin, the endogenous inhibitor of calcium-activated neutral proteases (calpains; EC 3.4.22.17), was studied in the rabbit vastus lateralis muscle by means of immunochemical and immunohistochemical techniques. Immunoaffinity chromatography using an antibody raised against the 34-kDa monomer of the 68-kDa dimeric inhibitor allowed us to isolate three main proteins (130-, 100- and 80-kDa). These proteins strongly inhibited calpain activity in muscle homogenate (I50 at about 50 micrograms/ml). Immunohistochemical experiments showed that calpastatin-related immunoreactivity was present in all fibre types (oxidative, glycolytic, oxidative-glycolytic) at both surface and cytoplasmic level. However, a few (20%) of the slow-twitch, oxidative fibres (5% of the total fibres), did not contain the cytoplasmic inhibitor. Specific immunoreactivity for calpastatin was also associated with the interstitial connective tissue. These results suggest that (i) calpastatin in skeletal muscle, as in other tissues, is present as a mixture of proteins of various molecular weights and (ii) the inhibitor may act not only in the cytoplasm but also at the surface or extracellular level.

Animals↗
PubMed1992

Synthesis and secretion of alpha 2-macroglobulin by human glioma established cell lines.

Human alpha 2-macroglobulin (alpha 2M) is a high molecular weight plasma proteinase inhibitor exhibiting a broad specificity; in fact it is capable of binding endopeptidases from all known classes of proteases (Barret 1981). Two human glioma cell lines, namely an astrocytoma and a glioblastoma, were found to synthesize and secrete in the culture medium a protein which resembles the serum alpha 2M for immunological, biochemical and biological features. Using polyclonal antibodies to serum alpha 2M, an alpha 2M-like factor could be detected in the cytoplasm and in the culture medium of the tumor cells. Furthermore this factor accumulated in cytoplasmic granules if cells were incubated with monensin and its production was dramatically reduced following a treatment with cycloheximide. This protein behaved like the serum alpha 2M in immunoblotting analysis and exhibited the same antiproteolytic activity. Its role in human brain is unknown at present. Since interactions of proteinases and proteinase-inhibitors appear to influence the host-tumor immune response and to play a crucial role during the migration of metastasizing tumor cells, alpha 2M expression observed in these glioma cells could be involved in tumor cell proliferation and invasion.

Astrocytoma↗
PubMed1992

Human astroglial but not microglial cells synthesize alpha 2-macroglobulin in vitro.

Alpha 2-macroglobulin (alpha 2M) is a serum proteinase inhibitor with a broad specificity. At present its role in human brain is unknown, but recent data report its presence in the CNS, particularly at glial level. Previous studies from our group demonstrated the synthesis and secretion of alpha 2M in different glial cultures derived from an astrocytoma and a glioblastoma. In the present study a human fetal astroglial cell line and two microglial established cell lines are examined for the presence of alpha 2M by using polyclonal antibodies in ELISA and immunofluorescence assays. While we observed a strong specific positivity in the cytoplasm and in the culture medium of the GFAP, vimentine positive cells, no positivity was detected in FcR, lysozyme positive microglial cells. Since interaction of proteinases and proteinase inhibitors appear to play a crucial role in the development of neuroimmunological competence, these data suggest a dissociation of macro and micro-glia immune functions.

Astrocytes↗
PubMed1992

Inter-alpha-trypsin inhibitor-related immunoreactivity in human tissues and body fluids.

The distribution of inter-alpha-trypsin inhibitor (ITI) and related inhibitors was investigated in normal human tissues and body fluids by using an enzyme-linked immunosorbent assay (ELISA) and a streptavidin-biotin-peroxidase immunohistochemical technique. ITI-related immunoreactivity was localized in different cell types of various organs, such as liver, kidney, testis, gross intestine, cutis and brain. Specific immunoreactivity was also detected in serum, urine and bronchial mucus. This widespread, but not ubiquitous pattern of localization suggests that, in addition to the well known plasmatic role, ITI and/or ITI-related inhibitors may play a number of different physiological roles in various human tissues.

Adult↗
PubMed1992

On the fine structure and complex carbohydrate cytochemistry of the rabbit parotid gland.

The parotid gland of the rabbit, a lagomorph species, was studied by ultrastructural techniques and carbohydrate ultracytochemical stainings. The rabbit parotid gland is a peculiar mixed gland consisting of serous and mucous secretory cells due to their histochemical properties supported by biochemical findings. Acinar cells exhibit heterogeneous features of secretory granules with different electrondensity and occasional presence of subunits. Intercalated duct cells show nuclei with deep indentation and apical granules partly similar to acinar secretory products. Striated ducts are characterized by three different cell populations, namely "light cells" with small secretory granules, "dark cells" rich of scattered mitochondria and typical striated cells. The presence of differentiated cell types within striated duct segments lends credence to the idea that, in addition to the role in electrolyte transport, some ductal cells may be involved in secretion and/or absorption of glycosylated products.

Animals↗
PubMed1991

Characterization of the in vitro sensitivity of human lymphoid and hematopoietic progenitors to L-leucyl-L-leucine methyl ester.

L-leucyl-L-leucine methyl ester (LLME) is a lysosomotropic agent that in microMolar concentrations has been found to be selectively toxic to human and murine precursor and effector cytotoxic cells, irrespective of their surface membrane phenotype. We describe a new method of synthesis of LLME and evaluate the effects of this preparation on human lymphoid and hematopoietic progenitor cells. The new method of synthesis did not change the previously characterized activities of LLME. Consistent with previous observations, NK effectors, LAK precursors and effectors, and allospecific CTL (aCTL) effectors were completely ablated by treatment with 50-250 microM LLME, while the activities of helper T cells and B cells were preserved after treatments of up to 1000 microM LLME. The effects of LLME treatment on human marrow-derived erythroid, myeloid, and monocyte progenitors have not been previously described. We found that the growth of each of these committed precursors was reduced or eliminated following treatment with 100-250 microM LLME. Admixture of LLME-treated marrow with marrow depleted of T cells and other mature cellular elements resulted in increased growth of myeloid and erythroid colonies suggesting that cells that could provide colony-enhancing activities were preserved. In contrast to previous studies in humans, we found a minority of individuals to have aCTL precursors that were partially resistant to LLME. PBL from 10 of 15 individuals tested showed nearly complete ablation of aCTL precursors following treatment with 375 microM LLME. The remaining 5 individuals demonstrated significant aCTL precursor activity after identical treatment. The resistance to LLME was restricted to aCTL precursors, and neither increasing the dose of LLME nor prolonging the time of treatment completely overcame the resistance. The pattern of susceptibility (sensitive versus resistant) was found to be independent of the degree or type of HLA disparity between responder and stimulator. LLME-treated cultures with and without CTL activity contained a predominance of CD4+ T cells. However, in the subjects tested LLME-resistant aCTL was shown to be CD8+. In vitro priming of aCTL precursors from sensitive individuals did not consistently result in the development of resistance to LLME. These data indicate that further studies are needed to evaluate the effects of LLME on human stem cells and to determine the potential role of resistant aCTL precursors in GvHD prior to application of this technique as a form of selective T cell depletion in humans.

Antibody Formation↗
PubMed1991

Structural and cytochemical observations in the submandibular gland of unweaned cats.

An investigation by electron microscope was performed on the submandibular gland of unweaned cats for studying its morphology and carbohydrate histochemistry. The cytoarchitecture was comparable with that of adult animals with the exception of the degree of membrane merging in both demilunar and acinar cell secretory granules. Conversely, the submandibular gland of unweaned cats showed a peculiar HID-TCH-SP reactivity at acinar cell level.

Animals↗
PubMed1989

Effects of recombinant human granulocyte colony-stimulating factor on neutropenia in patients with congenital agranulocytosis.

Congenital agranulocytosis is a disorder characterized by severe neutropenia and a profound deficiency of identifiable neutrophil progenitors in bone marrow. In an attempt to stimulate neutrophil production and thereby reduce the morbidity and mortality associated with this disease, we administered recombinant human granulocyte colony-stimulating factor (rhG-CSF) in doses of 3 to 60 micrograms per kilogram of body weight per day to five patients with congenital agranulocytosis. In all five patients, an increase in the number of neutrophils was noted eight to nine days after the initiation of the effective dosage (the dose at which the neutrophil count reached 1000 cells per microliter or more and the bone marrow showed granulocyte maturation beyond the myelocyte stage). The absolute neutrophil counts rose from less than 100 to between 1300 and 9500 cells per microliter. Marrow aspirates obtained after 14 days at the effective dosage showed maturation to the mature neutrophil stage. The side effects that were observed were medullary pain, splenomegaly, and an elevation of levels of leukocyte alkaline phosphatase. All five patients have had sustained neutrophil counts of 1000 cells per microliter or more for 9 to 13 months while receiving subcutaneous maintenance therapy. Preexisting chronic infections have resolved clinically, and the number of new infectious episodes and the requirement for intravenous antibiotics have decreased. We conclude that treatment with rhG-CSF can lead to a large increase in the numbers of functional neutrophils in patients with congenital agranulocytosis.

Adult↗
PubMed1989

Bovine pancreatic trypsin inhibitor and related isoinhibitors in bovine liver. A biochemical and histochemical study.

A Kunitz-type inhibitor family has been biochemically and histochemically characterized in bovine liver. This family includes the well-known pancreatic trypsin inhibitor (BPTI) and three BPTI-related molecular forms (isoinhibitors I, II and III). The purification of the inhibitors was performed by affinity chromatography on immobilized trypsin followed by fast protein liquid chromatography. The inhibitors were identical to those identified previously in bovine spleen and lung. Light immunohistochemical experiments were done by a streptavidin-biotin-peroxidase method using two different immunoglobulin preparations, which selectively discriminated between BPTI and the other isoinhibitors. BPTI-related immunoreactivity was found exclusively at the level of isolated cells, of which many were identified as mast cells by toluidine blue staining. By contrast, isoinhibitor-related immunoreactivity showed a more widespread distribution, including hepatocytes, mast cells and biliary duct epithelial cells. Finally, specific immunoreactivity was also present in plasma. These results suggest that: i) BPTI and related isoinhibitors may be involved in the regulation of the activity of some mast cell proteases, as it happens in other bovine organs (Businaro et al. 1987, 1988); ii) BPTI isoinhibitors, but not BPTI itself, may also control proteolytic activities in hepatic specific structures (hepatocytes and biliary duct epithelial cells).

Animals↗
PubMed1989

Identification and immunohistochemical localization of various bovine pancreatic trypsin inhibitor-isoforms in bovine pituitary gland.

Three isoinhibitors of bovine pancreatic trypsin inhibitor (BPTI) have been identified and isolated from bovine pituitary gland. The results of the purification process by affinity chromatography on immobilized trypsin, the electrophoretic mobility in non-denaturing conditions, the antiproteolytic activity and the immunochemical reactions indicate that these inhibitors correspond to those previously isolated from bovine spleen and lung. In addition, immunohistochemical experiments show that the isoinhibitors and BPTI are exclusively localized in the mast cells, and not in the endocrine cells, of the pars intermedia and posterior lobe (neurohypophysis) of the pituitary gland. The physiological implications of these findings are discussed.

Animals↗
PubMed1989

Ultrastructure and complex carbohydrate ultracytochemistry of the cat parotid gland.

The structure and glycoconjugate content of the cat parotid gland were analyzed at electron microscopic level by applying morphological techniques and three ultrastructural histochemical methods - HID-TCH-SP, LID-TCH-SP and PA-TCH-SP. This gland appeared as a typical salivary gland composed of acinar secretory cells, intercalated ducts, striated ducts and excretory ducts. The most common configuration of secretory granules consisted of a dense core surrounded by a variable electron-lucent halo. All ductal segments were characterized by the presence of different cell populations and small apical granules greatly different from those localized in the acinar cells. By using HID-TCH-SP we were able to demonstrate that in a few acinar cells there are sulphated sites, whereas PA-TCH-SP staining revealed the presence of vic-glycol radicals in all acinar cells preferentially located on the halo of secretory granules.

Animals↗
PubMed1988

Cellular localization of bovine pancreatic trypsin inhibitor and related molecular forms in bovine lung.

In addition to bovine pancreatic trypsin inhibitor (BPTI), three BPTI-related molecular forms (isoinhibitors I, II and III) were isolated from bovine lung by affinity chromatography on immobilized trypsin and subsequently purified by Fast Protein Liquid Chromatography. These inhibitors are identical to the isoinhibitors previously isolated from bovine spleen. Their localization in bovine lung was studied by immunohistochemical techniques, using two different immunoglobulin preparations, selectively recognizing BPTI or the other molecular forms. BPTI-related immunoreactivity was found to be restricted to isolated cells, often identified as mast cells by Toluidine Blue staining. In contrast, isoinhibitor-related immunoreactivity, which also occurs in the mast cells, is present in a number of other cell types. These types include: (i) the smooth muscle cells of different calibre vessels, (ii) the ciliated cells of the bronchial epithelium and the related mucus, and (iii) many cells at alveolar level. Comparison of these data with previous results obtained for bovine spleen suggest multiple physiological roles for these inhibitors.

Animals↗