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Biomedical subjects

E Galdiero

Publications and source records attributed to E Galdiero.

26 records · Page 2Linked to original sources
PubMed1988

The action of LPS porins and peptidoglycan fragments on human spermatozoa.

This study examines the action of the cell wall components of enterobacteria on the vitality of human spermatozoa. Lipopolysaccharides extracted from Escherichia coli K12 killed about 80% of the spermatozoa at a concentration of 50 micrograms/ml. Porins extracted from E. coli, Proteus mirabilis and Salmonella typhimurium killed between 80% and 100% of the spermatozoa at a concentration of 50 micrograms/ml. Muramic acid and N-acetylmuramic acid caused about 60% mortality at a concentration of 50 micrograms/ml. The possibility that the products of cellular lysis in the course of gram-negative infections cause temporary sterility is discussed.

Bacterial Outer Membrane Proteins↗
PubMed1987

Adherence of bacteria to cardiac valve prostheses.

The adherence of bacterial cells to valvular prostheses has been studied. Bacteria were selected on the basis of their surface features (fimbriae, hydrophobicity and specific receptors). It was found that only strains having fimbriae and high cell surface hydrophobicity adhered to bioprostheses, while they did not adhere to metallic prostheses to any significant extent. Adherence to bioprostheses depended on the exposure time and it was affected by the saline concentration of the suspension medium. Furthermore, different bacterial binding capacity was observed for bioprostheses from different companies.

Bacterial Adhesion↗
PubMed1986

Comparative study of some biological activities of porins extracted from various microorganisms.

The outer membrane of Gram-negative bacteria contains some major proteins, called porins, with particular chemical and physical characteristics which reflect some specialized functions peculiar to the outer membrane. In recent years the biological properties of Salmonella typhimurium SH5014 porins have been the focus of our experimental studies. The aim of the present research was to make a comparative investigation of the biological activities of porins extracted from other microorganisms classified in the Enterobacteriaceae, together with a taxonomically different one, Eikenella corrodens frequently isolated from gum pockets of patients with periodontal disease. Porins from E. coli K12, Proteus mirabilis and Eikenella corrodens were extracted, purified and separated from LPS by means of phenol extraction. The purity of preparation was checked by sodium dodecyl sulphate polyacrylamide gel electrophoresis in slabs. We studied the interactions of these proteins with some cellular and humoral systems within the host. Mouse peritoneal macrophages in the presence of these proteins show morphological and functional modifications, depending upon the type of porins and the concentrations used. The ability of porins to interact with the complement system was investigated in vitro. A pool of sera from 20 blood donors served as a source of human complement. The results obtained with porins of various sources were shown comparatively.

Animals↗
PubMedDate not supplied

Interactions between bovine endothelial cells and Pasteurella multocida: association and invasion.

We investigated the association and the invasion of a bovine aortic endothelial cell (BAEC) line by Pasteurella multocida to study the potential role of internalized bacteria and possible intracellular survival during Pasteurella infections. Our data indicate that P. multocida is able to adhere to and to invade BAECs. The density of the bacterial population plays a defined role for an optimal mechanism of interaction between bacteria and cells, as does the incubation period of association and invasion. The optimal bacteria/cells ratio was found to be 100/1, while the optimal infection time was approximately 4 h of incubation. Bacterial internalization was dependent on microfilament and microtubule stability. The invasion ability of P. multocida in the presence of cytochalasin D was reduced by 60%; in the presence of colchicine it was reduced by 97% and in the presence of nocodazole it was reduced by 95%. Our data show that internalized P. multocida did not induce mortality of invaded endothelial cells. Some Pasteurella cells were able to survive and undergo exocytosis.

Animals↗
PubMedDate not supplied

Modulation of costimulatory molecules CD80/CD86 on B cells and macrophages by stress proteins GroEL, GroES and DnaK.

The aim of this study was to evaluate the effect of the Heat Shock Proteins GroES, GroEL and DnaK on the expression of the costimulatory molecules CD80/CD86 in B cells and macrophages. The interactions among these molecules are able to highly influence the immune response through the regulation of cytokine liberation which, on their own, are able to regulate the immunological response by a feedback mechanism. Our results showed that, on B cells, GroES and GroEL stimulated the expression of CD86 but did not induce the increase of the CD80 expression. CD86 peak expression showed a peak after 24-48 h of culture and decreased 60h after the stimulation. GroES and GroEL also stimulated the expression of CD80 and CD86 on macrophages. The same HSPs did not modify the expression of CD80 and CD86 on cells having characteristics of activated macrophages, the A-THP-1 cell line. DnaK did not induce any increase in the expression of CD80 and CD86 on lymphocytes or macrophages.

Adult↗
PubMedDate not supplied

Th1-Th2 response in hyperprolactinemic mice infected with Salmonella enterica serovar Typhimurium.

Prolactin (PRL) is a pituitary hormone and a cytokine known to regulate several physiological functions. It plays a role in modulating the immune system of rodents and humans. A hormonal protection against listeria and salmonella infections has been previously ascribed to effects of PRL on immunocompetent cells. Here, the role of PRL in the Th1-Th2 response was evaluated based on the pattern of cytokines release by splenocytes from hyperprolactinemic mice infected with Salmonella enterica serovar Typhimurium. Hyperprolactinemia by pituitary graft reduced the number of bacteria in spleens of in vivo infected mice. Modulation of Th1 (IFN-gamma, IL-12) and Th2 (IL-4, IL-10) cytokine production by splenic cells was found. Our results indicate that PRL can up-regulate IFN-c and IL-12 secretion in response to salmonella infection, confirming its in vivo immunostimulatory effect and suggesting hormonal participation in the genesis and sustenance of the Th1 response.

Animals↗
PubMedDate not supplied

Clearance studies on the renal action of porins extracted from Salmonella typhimurium.

The effects of porins on renal hemodynamics and on the renal handling of salt and water were studied in rats. The animals injected with 100 micrograms/kg of porins showed an important change in renal potassium handling. In fact the total potassium excretion decreased significantly (p less than 0.02) from 1.11 +/- 0.13 to 0.495 +/- 0.069 muEq/min/100 g and was significantly associated to a reduction of fractional potassium excretion from 21.6 +/- 4.1% to 12.53 +/- 0.95% (p less than 0.001). It is speculated that porins have the capability to close the potassium channels.

Animals↗