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F Galdiero

Publications and source records attributed to F Galdiero.

At least 73 records · Page 4Linked to original sources
PubMed1969

Cation-binding capacity of membranes isolated from Micrococcus lysodeikticus.

A study was made of H(+), Na(+), K(+), Ca(++), and Mg(++) binding and ion-exchange properties of the plasma-mesosome membrane system isolated from Micrococcus lysodeikticus strain NCTC 2665. Titration curves were obtained on membranes prepared according to the method of M. R. J. Salton and further exposed to pH 4 for 4 hr (membranes-H). The dissociation coefficients and binding capacities were obtained by applying the mass law equation and the plot of G. Schatchard to the data. The membranes-H possess four kinds of dissociable groups with pK 4.96, 4.18, 3.60, and 3.09, respectively, and a total binding capacity of 0.65 meq/g (dry weight). Potentiometric titrations of cations in the presence and in the absence of membranes-H show that cations (Na(+), K(+), Ca(++), and Mg(++)) are bound by the dissociated groups of the membrane. The fall in pH value for bivalent cations is greater than that for monovalent cations. Cations of the same valency produce equal diminutions on pH. Furthermore, ion-exchange tests carried out on membranes saturated with Mg(++) or Na(+) and suspended in a medium containing (45)Ca show that the cations are reversibly bound.

Calcium↗
PubMedDate not supplied

Effect of modification of HEp 2 cell membrane lipidic phase on susceptibility to infection from herpes simplex virus.

We have verified the consequences of alterations of the lipidic phase of HEp 2 cell membranes on susceptibility to infection from Herpes simplex virus, and have related these results to modification in membrane fluidity. This was carried out by treating HEp 2 cells with saturated and unsaturated fatty acids with chain lengths from eight to 18 carbon atoms. The results show that HEp 2 cells treated with saturated fatty acids with eight and ten carbon atoms have both increased membrane fluidity and increased susceptibility to Herpes simplex virus infection while both parameters were reduced when HEp 2 cells were treated with saturated fatty acids having 14 and 18 carbon atoms. Fatty acids with 16 carbon atoms, however, show an increase in membrane fluidity which has no significant correlation to infection susceptibility. As to unsaturated acids, those with eight carbon atoms, 2-octenoic acid (trans-8: 1[2]) and 2-octynoic acid (8:::1[2]), increase the susceptibility to infection and fluidity while low concentrations of monounsaturated acids with 14 and 18 carbon atoms, myristoleic acid (cis-14:1[9]) and oleic acid (cis-18:1[9]), reduce both the susceptibility to infection and the fluidity of the membrane.

Cell Line↗
PubMedDate not supplied

Multicentric study of seroprevalence of Borrelia burgdorferi and Anaplasma phagocytophila in high-risk groups in regions of central and southern Italy.

The aim of this study was to evaluate the seroprevalence of B. burgdorferi and A. phagocytophila in populations of workers from 4 Italian regions, known to be exposed to tick bites. A total of 712 serum samples collected were divided as follows: 387 samples were obtained from workers at risk for tick bites and 325 from individuals that were not considered to be at risk of ticks bites and served as the control group. Antibodies against B. burgdorferi were found in 29 (7.5%) of the 387 risk workers and in 4 (1.2%) of the 325 control group. Antibodies reactive with the HGE agent were found in 22 (5.7%) of the 387 risk workers and in 3 (0.9%) of the 325 control group. Antibodies to both B. burgdorferi and A. phagocytophila were found in 1.6% of the forestry workers confirming the possibility of coinfection or concurrent infection. The present finding show significant differences between seroprevalence of the risk workers and that of the people with no risk for tick exposure.

Anaplasma phagocytophilum↗
PubMedDate not supplied

Effects of cytokines and prolactin on the replication of Toxoplasma gondii in murine microglia.

In the central nervous system, cytokine-activated microglia play a crucial role in host defence against Toxoplasma gondii infections. In this study, the effect of recombinant tumor necrosis factor (rTNF)-alpha and prolactin (PRL) on T. gondii infection in microglia was examined. Pretreatment of microglia with rTNF-alpha and PRL induced toxoplasmastatic activity, the intracellular killing of T. gondii and the release of interleukin (IL)-1 beta IL-3 and IL-6: 50% of the intracellular killing was abrogated by anti-ICAM-1 monoclonal antibodies, whereas more than 54 or 87% of toxoplasmastatic activity was reversed by anti-IL-3 or IL-6 monoclonal antibodies. In addition, the treatment of microglia with either rIL-3 or rIL-6, in the absence or presence of rTNF-alpha significantly limited T. gondii replication. Inasmuch as either NMA or S-M-ITU affected cytokine-activated toxoplasmastatic activity during the infection phase, the NO-dependent pathway itself appears not to be directly involved in the parasitostatic activity. These findings suggest that TNF-alpha and PRL up-regulate the expression of ICAM-1 and the production of endogenous IL-6 and IL-3 by microglia, which could induce anti-parasitic functions against T. gondii infection in the brain.

Animals↗
PubMedDate not supplied

Protein A and other surface components of Staphylococcus aureus stimulate production of IL-1 alpha, IL-4, IL-6, TNF and IFN-gamma.

Studies were carried out on the ability of protein A (PA) and of muramic acid (MA) from S. aureus to induce the release of cytokines both from monocytes and lymphocytes in vitro. Results show that protein A induces the greatest activity, compared to the activity already known for the theicoic acid (TA) and for muramyl dipeptide (MDP). At concentration of 10 micrograms/ml; PA induces roughly +180% release of TNF with respect to controls, while release of IL-1 alpha is about 500% control values, and is higher than those obtained when cells are treated with TA and MDP; IL-6 release is higher than that stimulated by Con A, used as standard challenge. At PA concentrations of 5 micrograms/ml, IL-4 release is about five times higher than that induced by Con A. Release of IFN-gamma showed similar dose-dependent stimulations. Muramic acid (MA) is particularly active in inducing the release of cytokines from target cells, inducing TNF release of about +75% with respect to the controls. This increase is less than that obtained with PA. Also IL-4 and IFN-gamma are released by PA in quantities higher than those induced by TA and MDP. Our results lead us to believe that during infections by Gram-positive bacteria, their surface components are able to induce a series of chain reactions ranging from the inflammatory to the immunologic responses which are also conditioned by release of cytokines.

Humans↗