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Biomedical subjects

F Paradisi

Publications and source records attributed to F Paradisi.

At least 109 records · Page 6Linked to original sources
PubMedDate not supplied

Effect of a new fluorinated quinolone (ofloxacin) on the chemiluminescence of phagocytosing human neutrophils.

We measured the chemiluminescence (CL) of human neutrophils (PMNLs) exposed to different concentrations of ofloxacin (2, 4, and 6 micrograms/ml) readily achievable in therapy. CL reaction during zymosan phagocytosis by PMNLs obtained from human healthy volunteers was registered in a computer-linked LKB 1251 luminometer. Ofloxacin did not induce significant variations on the respiratory burst of PMNLs.

Humans↗
PubMedDate not supplied

The influence of bacterial exotoxins and endotoxins on the phagocytic activity of human macrophages in culture.

The effect of bacterial exotoxins and endotoxins on phagocytosis was tested on human macrophages in monolayer cultures by determining the rate of zymosan particle ingestion at different toxin concentrations and incubation times. The exotoxins tested were staphylococcal alpha-toxin and diphtheria-toxin. The endotoxins used were lipopolysaccharides from Salmonella typhi, Salmonella typhimurium, Shigella flexneri and Serratia marcescens. Phagocytosis was significantly impaired after prolonged incubation with diphtheria toxin whereas alpha-toxin was ineffective. Endotoxin-treated macrophages showed a wide range of phagocytic activity. Enhancement of phagocytosis was observed with a low concentration of endotoxin (1 microgram/ml) from S. typhi, S. typhimurium and S. flexneri. Higher concentrations (2.5 and 5 micrograms/ml) depressed phagocytosis to varying extents, except for S. typhi lipopolysaccharide, which did not induce a significant decrease in phagocytosis in comparison to the controls.

Cells, Cultured↗
PubMedDate not supplied

The influence of in vivo pretreatment of cyclophosphamide on phagocytic activity of mouse macrophages in vitro.

The action of cyclophosphamide on phagocytosis by macrophages from mouse peritoneal exudate cultured in vitro was studied. The mice were pretreated with cyclophosphamide administered for seven days. The experiments were carried out in the presence of serum (with or without complement) from untreated animals or without serum. A significantly increased phagocytic activity was shown in experiments without serum and when decomplemented serum was used. No significant variation was found when macrophages from treated mice were tested with serum with complement from untreated animals. It is tentatively assumed that low dosage administration in vivo of cyclophosphamide does not affect macrophage phagocytic activity while several findings suggest an inhibitory effect of cyclophosphamide on T and B lymphocytes.

Animals↗
PubMedDate not supplied

Uptake of fluorochrome-labelled exotoxins by different cell types in culture.

The uptake of diphtheria toxin and of Staphylococcus alpha-toxin by two different human cell types cultured in vitro (the HEp-2 continuous cell line and human adult hepatocytes) was studied by fluorescence microscopy and phase-contrast microscopy. The behavior of these two bacterial exotoxins was quite different. Diphtheria toxin was incorporated into cells by pinocytosis, whereas alpha-hemolysin penetrated into the cytoplasm probably through lesions in the cell membrane. In addition, the penetration of diphtheria toxin into the cells was not inhibited by specific antiserum, whereas anti-alpha-haemolysin inhibited the penetration of alpha-tpxin through the cell membrane. The significance of these findings is discussed.

Animals↗
PubMedDate not supplied

Ultrastructural changes in HEp-2 cells treated with staphylococcal alpha-toxin.

The effect of highly purified staphylococcal alpha-toxin on HEp-2 neoplastic cells growing in culture was studied by electron microscopy. In addition to some nuclear modifications, the most significant morphological changes were in mitochondrial structure, alpha-toxin seems to induce a defined sequence of changes in mitochondrial configuration which can be summarized as an earlier phase of 'condensation' of mitochondrial structure and a later phase of mitochondrial swelling with an intermediate 'transitional' configuration. The significance of these findings is discussed in the light of the present state of knowledge of the biological characteristics of staphylococcal alpha-toxin.

Bacterial Toxins↗
PubMedDate not supplied

Lumbar pain in a married couple who likes cheese: brucella strikes again!

A 69-year-old man living in Florence reported fever and acute lumbar pain one month after transurethral resection of a superficial transitional cell carcinoma of the bladder. The radionuclide bone scan suggested metastatic lesions of the L3-L4 vertebrae. However cobalt treatment was ineffective. A bone biopsy of L4 showed an inflammatory pattern and antibiotic therapy was started which did not produce any clinical improvement. Six months after the onset of the back pain brucellar spondylitis was serologically diagnosed and treatment with doxycycline and streptomycin produced a significant clinical and radiological improvement. After 2 months the patient's wife presented with fever and lumbar pain, and brucellar spondylitis was diagnosed as well. An extensive epidemiological examination revealed that 8 months earlier the family had eaten unpasteurized goat cheese and serological examination of the entire family showed that 3 out of 4 members had significant titres of brucellar antibodies. Finally it was discovered that 4 months after consuming the cheese the third infected subject experienced an episode of epidydimoorchitis for which no diagnosis and effective treatment was found. This family cluster of brucellar infection indicates that a high degree of suspicion in the diagnosis of brucellosis is necessary even in non-endemic areas, to reduce the delay in the diagnosis and treatment of the disease and to prevent the occurrence of complications that may prove difficult to treat.

Aged↗