PubMed Health⌕ Search

Biomedical subjects

D Fumarola

Publications and source records attributed to D Fumarola.

At least 145 records · Page 8Linked to original sources
PubMed1977

Demonstration of platelet electrophoretic mobility slowing factor (PSF) in supernatants of human lymphocyte cultures stimulated by phytohaemagglutinin (PHA).

It has been demonstrated that human peripheral lymphocytes, stimulated with PHA, form or release a factor that slows platelet electrophoretic mobility (PEM). The factor is chromatographed on Ultrogel AC a 44, has a molecular weight of approximately 45,000, is stable on heating at 56 degrees C for 30 min, but is inactivated by heating at 80 degrees C for 10 min. In addition, it is distinct from leukocyte inhibiting factor, which elutes in the range of BSA (mol. wt. 69,000). The authors conclude, in accordance with previous investigations, that cellular immunity is involved in thrombotic processes.

Blood Platelets↗
PubMed1977

[About employing platelets to determine enterotoxigenic activity of E. coli and others enterobacteria. Preliminary approach (author's transl)].

After an introduction concerning to the assays employed in vitro and in vivo to determine enterotoxigenic activity of E. coli the A. suggest a new in vitro model as a preliminary approach based upon the influence of LT enterotoxin of E. coli on platelet aggregation (inhibitory effect) as expression of stimulation of adenylatecyclase activity evoked by this fraction and eventually by other choleralyke fractions released from enterobacteria.

Animals↗
PubMed1977

Effects of tilorone hydrochloride on cellular immunity (leukocyte inhibiting factor production from human lymphocyte stimulated by E. coli lipopolysaccharide).

Tilorone hydrochloride, a drug able selectively to affect T-lymphocyte fuction, when incorporated (at three different concentrations 0.1, 0.04, 0.02 microgram/ml) in lymphocyte culture, stimulated by 50 microgram/ml of E. coli LPS (026:B6 W), is able to abolish LIF production, due to endotoxin stimulation. Such effect is, may be, due to an impairment of T-cell activity, since tilorone at the same concentration decreases the number of ARFC and TRFC, which are specific markers for T-cells.

Escherichia coli↗
PubMed1977

Effect of some bacterial products on platelet electrophoretic mobility (PEM).

Bacterial LPS, used in our experiments, are able to decrease PEM at concentration of 100 microgram/ml after incubation with 1 X 10(7) platelets/ml for 30 min at 37 degrees C. Such effect is statistically significant for Bacteroides fragilis LPS, S. enteritidis and S. typhi. E. coli LPS 026:B6 W and E. coli 055:B5 W are not effective at all, S. minnesota (incomplete) LPS 595 and 345 free of 0-polysaccharide and partially lacking core in their molecule did not influence PEM, while S. minnesota LPS (S form) (a complete LPS) strongly decreased PEM. This fact could suggest that 0-polysaccharide is involved in this inhibitory effect on PEM. Klebsiella enterotoxin and B. cereus enterotoxin are able to decrease PEM at concentration of 100 microgram/ml, after incubation with 1 X 10(7) platelets for 30 min at 37 degrees C, while no inhibition of PEM was seen when Shighella enterotoxin and V. parahaemoliticus enterotoxin was used in similar way. The AA. conclude that endotoxin and enterotoxin are able to change the electrokinetic charge (negative) of platelets, thereby, causing a decrease of PEM.

Bacillus cereus↗
PubMed1977

Limulus test, parenteral drugs and biological products: an approach.

The authors report their experience with the LAL test for endotoxin assay. They have examined parenteral drugs, blood products and biological substances employed in immunology. The results were compared with rabbit pyrogen tests. All the data suggest that if correctly performed, the LAL test is a simple, rapid and sensitive test. This assay appears to be very useful for materials employed in immunology in order to test the possible contamination with bacterial endotoxin, since the interference between endotoxin and immunologic response is well known.

Animals↗
PubMed1976

Clinical experience in detecting endotoxemia with the limulus test in typhoid fever and other Salmonella infections.

Semiquantitative estimates of circulating endotoxin were performed by the limulus test in patients suffering from typhoid fever and other salmonelloses. The test was positive in a large number of cases. However, no clearcut correlation was found between existence of endotoxemia, as such, and pyrexia. A correlation with recent bacteremia was found for highest levels of endotoxin activity. In minor salmonelloses a striking prevalence of positive cases was observed in the age group under one year. These findings were discussed in relation to the diagnostic and pathogenetic facets of the problem.

Adolescent↗
PubMed1976

Limulus test, parenteral drugs and biological products: an approach.

The Authors report the results concerning the control of the presence of bacterial endotoxins in parenteral drugs, blood products and immunological reagents and drugs, by means of Limulus amebocyte lysate test. All the data suggest that Limulus assay is a simple, rapid, sensitive test, mostly when it is correctly performed.

Antibody Formation↗
PubMed1976

[Possible use of the platelet as the cell system for the control of enteropathogenicity of E. coli and of other enterobacteria. Preliminary approach].

After an introduction concerning the assays employed in vitro and in vivo to determine enterotoxigenic activity of E. coli, the A. suggests a new in vitro model as a preliminary approach based upon the influence of LT enterotoxin of Escherichia coli on platelet aggregation (inhibitory effect) as expression of stimulation of adenylatecyclase activity evoked by this fraction and eventually other cholera-like fractions released from enterobacteria.

Animals↗
PubMed1976

Leukocyte inhibiting factor (LIF) production from human lymphocytes stimulated by bacterial lipopolysaccharides.

Leukocyte inhibiting factor (LIF) release from lymphocytes cultures stimulated by bacterial lipopolysaccharides (LPS) has been investigated. Human lymphocytes cultured in the presence of E, coli or S. enteritidis LPS were able to release in the supernatants a substance with the following properties: a) same elution pattern of Bovine Serum Albumin (MW 69000) when filtered on Sephadex G-100; b) it migrates on disc electrophoresis a an albumin; c) not dialyzable; d) not cytotoxic; e) inhibition of polymorphonuclear cells migration in agarose plates; f) heat stability at 56 degrees C for 30'. This substance could be likely identified as LIF.

Antibody Formation↗
PubMed1976

Platelet-endotoxin interaction: a review.

The studies reviewed in the present manuscript outline the effects of bacterial endotoxins on human and animal platelets. In animals the endotoxin administration is followed by thrombocytopenia, presence of platelet aggregates in the blood vessels of several organs, appearance of appreciable quantities of serotonin in plasma and increased platelet factor 3 availability. These in vivo effects can readily be explained by the in vitro demonstration that endotoxin aggregates platelets, induces release of vasoactive amines and adenine nucleotides and activates platelet factor 3. There is substantial evidence suggesting that the mechanism of this animal platelet-endotoxin interaction is immunological and complement dependent. In humans thrombocytopenia is frequently observed in endotoxemia as encountered during Gram-negative sepsis indicating that platelets are involved in some of the biological effects endotoxin. In vitro experiments demonstrate that several endotoxin preparations significantly enhance a weak procoagulant activity of human platelets different from platelet factor 3.

Animals↗