Search PubMed⌕ Search

Biomedical subjects

A Caprioli

Publications and source records attributed to A Caprioli.

At least 91 records · Page 5Linked to original sources
PubMed1990

Isolation in Italy of a verotoxin-producing strain of Escherichia coli O157:H7 from a child with hemolytic-uraemic syndrome.

Verotoxin-producing Escherichia coli O157:H7 was isolated for the first time in Italy from a child with hemolytic-uremic syndrome and his asymptomatic sister. Both parents remained asymptomatic, and neither had evidence of this infection. The source of the infection was not identified, but the children had eaten ground beef during the 15 days prior to the onset of symptoms.

Bacterial Toxins↗
PubMed1990

Age-dependent deficits in radial maze performance in the rat: effect of chronic treatment with acetyl-L-carnitine.

1. An eight-arm radial maze was the experimental model used to investigate spatial learning in rats of different ages and in old rats treated with Acetyl-L-Carnitine. 2. Extramaze visual cues were minimized in order to study the rat's ability to perform using a strategy. 3. The experimental findings indicated a deterioration of the old rat's ability to learn and solve the radial maze. 4. Long-term treatment (8 months) with Acetyl-L-Carnitine was found to antagonize such a deterioration.

Acetylcarnitine↗
PubMed1989

Haemagglutination and surface structures in strains of Clostridium spiroforme.

Five strains of Clostridium spiroforme were examined for their surface properties. All strains were able to agglutinate human erythrocytes. Electron microscopy showed a ruthenium red-positive capsule mediating the attachment of bacteria to erythrocytes. Two strains, showing the lowest degree of haemagglutination, exhibited an additional external layer of filamentous structures, possibly interfering with the agglutinating activity. In spite of their agglutinating ability, the C. spiroforme strains did not show surface hydrophobicity, thus suggesting the possible existence of a new type of clostridial adhesin.

Animals↗
PubMed1989

Cryptosporidium as a common cause of childhood diarrhoea in Italy.

Cryptosporidium oocysts were observed in the stools of 9 (7.2%) of 124 Italian children with diarrhoea, examined during the period 1 January-31 December 1984. In two children, the parasite was associated with other enteric pathogens. The duration of diarrhoea was 2-30 days, with a median of 6 days. In all cases the infection was self limiting. The mean age of the Cryptosporidium-positive children was 34 months, and all cases occurred in the warm season. Cryptosporidium was found to be the third most common enteric pathogen after rotavirus and Salmonella spp.

Animals↗
PubMed1989

Litter gender composition affects maternal behavior of the primiparous mouse dam (Mus musculus).

Thirty-nine litters of the outbred Swiss CD-1 mouse strain were reduced at birth to 6 pups, according to three conditions: MM (all males), MF (3 males and 3 females), or FF (all females). The maternal behavior of their respective dams (frequency and duration of nursing, licking, nest-building, and other activities such as eating, drinking, sniffing, grooming, and undirected locomotor activity) were scored during a single 10-min session on Days 2, 3, 5, 7, 10, 14, and 18. Dams rearing MM litters showed higher scores of maternal care on Days 2 and 18 in the case of nursing, on Days 2, 7, and 10 in the case of nest-building, and on Day 18 in the case of licking. These results confirm previous rat data, which indicated that male and female pups are exposed early in infancy to a different pattern of maternal behavior. Concomitant measurements of pup development (body-weight gain and achievement of a number of physiological and neurobehavioral landmarks) indicated that these effects of litter gender composition are not mediated by gross changes in the maturational trends of the pups.

Animals↗
PubMed1989

Relationship between cytotoxic necrotizing factor production and serotype in hemolytic Escherichia coli.

We examined the relationship between serotype and cytotoxic necrotizing factor (CNF) production in 123 hemolytic strains of Escherichia coli isolated from both stools and extraintestinal infections. Of 76 strains producing both hemolysin (Hly) and CNF, 66 (87%) belonged to one of six serogroups (O2, O4, O6, O22, O75, and O83). In contrast, 47 E. coli strains producing Hly only belonged to 21 different O serogroups, and only 2 of these (O6 and O18ac) were widely represented. Generally, CNF-positive and CNF-negative hemolytic isolates were assigned to different O serogroups, with the exception of O6, often present in both categories of isolates. Serogroups O4 and O18ac were significantly more prevalent among strains from extraintestinal infections than among those from stools. In contrast, the Hly-positive, CNF-negative isolates, belonging to numerous less common serogroups, were hardly ever isolated from extraintestinal infections. Serological typing further confirmed that hemolytic isolates of E. coli may grossly be divided into two main populations on the basis of the ability to produce CNF. Examination of hemolytic E. coli for this property may also be useful in achieving a more detailed characterization of pathogenic clones.

Bacterial Outer Membrane Proteins↗
PubMed1988

Comparison among enterotoxigenic strains of Escherichia coli isolated in Italy and Somalia.

Nine strains of ETEC isolated in Italy have been compared with 13 isolates from Somalia with respect to toxin production, serotype and antimicrobial resistance pattern. None of the strains isolated from Italy belonged to any serotype or serogroups found among the strains from Somalia. Remarkable differences between the two groups of isolates were also observed with regard to the susceptibility to antimicrobials and the presence of R-plasmids. These findings suggest that ETEC strains isolated in Italy are not related to the strains widespread in Somalia and, generally, in developing countries.

Antigens, Bacterial↗
PubMed1988

Cytoskeletal changes induced in HEp-2 cells by the cytotoxic necrotizing factor of Escherichia coli.

The effect of the cytotoxic necrotizing factor of Escherichia coli on HEp-2 cells was studied by fluorescence and scanning electron microscopy. This cytotoxin, known for inducing the formation of giant multinucleated cells in several cell lines, caused changes in actin and tubulin organization. The presence of membrane ruffles at the cell border and of numerous thick bundles of actin crossing the cell body, suggests that the factor promotes cell spreading; this probably interferes with cytokinesis, ultimately leading to the formation of very large flattened multinucleated cells. Moreover, the nuclear segmentation observed in treated cells seems to be associated with a rearrangement of actin in the perinuclear region and with the presence of tubulin bundles in proximity to nuclear clefts. Although the primary target is still unknown, these findings suggest that the cytoskeleton is affected accounting for the multinucleation process induced by the factor.

Bacterial Toxins↗
PubMed1987

Cytotoxic necrotizing factor production by hemolytic strains of Escherichia coli causing extraintestinal infections.

Two hundred and nineteen strains of Escherichia coli from extraintestinal infections and feces of healthy subjects were examined for hemolysin (Hly) and cytotoxic necrotizing factor (CNF) production and for mannose-resistant hemagglutination. Of 105 strains from extraintestinal infections, 42 (40.0%) were positive for production of both Hly and CNF, and 21 (20.0%) were positive for Hly alone; on the contrary, only 1 Hly- and CNF-positive strain and 2 Hly-positive strains were found among 114 strains from normal stools. CNF production was not found to occur among the nonhemolytic strains, confirming the close association existing between these toxic factors. Hemolytic strains positive for CNF showed mannose-resistant hemagglutination less frequently than did Hly-positive, CNF-negative strains (25.6 versus 82.6%), suggesting the existence of two distinct classes among hemolytic strains of E. coli.

Cytotoxins↗
PubMed1987

Adherence to and penetration of cultured cells by an invasive strain of Escherichia coli: an ultrastructural study.

The penetration process of an enteroinvasive strain of Escherichia coli 0124 into HEp-2 cells has been studied by electron microscopy. Bacteria penetrated into cultured cells by a phagocytosis-like mechanism, and multiplied within the vacuoles as well as in the cytoplasmic matrix. On the whole, the infection cycle of EIEC appeared to be similar to that described for Shigella. The stain examined has also been found to elaborate a 40 nm-thick glyocalix, which is probably involved in the recognition of host surface receptors and therefore in the attachment of microorganisms to the cell membrane.

Bacterial Adhesion↗
PubMed1986

Postnatal social environment affects morphine analgesia in male mice.

Seventy-eight male mice of the Swiss CD-1 strain were maintained from birth to weaning either in litters containing only male pups (MM), or in litters containing both male and female pups (MF). Body weight gain and neurobehavioral development were assessed, and no differences between MM and MF males were found. On postnatal day 40 one male from each litter (N = 13 per group) was injected either with vehicle (saline solution, 8%) or with morphine (5 or 10 mg/kg). Fifteen min after the injection, forepaw licking latencies were measured in a hot plate test (55 +/- 1 degree C). MF males showed longer latencies than MM males, and this difference was statistically significant after both morphine doses. These results indicate that the function of systems mediating response to painful stimulation and opiate analgesia can be affected by variations in early social conditions.

Aging↗
PubMed1986

Detection of clostridial toxins in stools from children with diarrhoea.

A cell-culture assay was used to detect toxins directly in stools from sporadic cases of infantile diarrhoea. Cytotoxins were revealed in 11 out of 58 samples from children with diarrhoea, nine of whom had no common enteric pathogens in their stools. A preliminary characterisation of the cytotoxins was obtained by neutralisation tests with clostridial antitoxins.

Bacterial Proteins↗
PubMed1986

Plasmid mediated gentamicin resistance in strains of Klebsiella from hospital acquired infections.

Two gentamicin resistant strains of Klebsiella were isolated at different times from patients with hospital acquired urinary tract infections. Both strains contained a conjugative 81-megadalton plasmid that encoded resistance to gentamicin, ampicillin, cephalothin and mercuric chloride. The plasmid conferred to Escherichia coli CSH26 the same pattern of resistance to eight aminoglycoside antibiotics and gave similar DNA fragments after restriction endonuclease digestion.

Conjugation, Genetic↗
PubMed1986

Dissemination of a gentamicin resistance plasmid in the microbial population of hospital patients.

The dissemination of a gentamicin resistant plasmid, originally found in strains of Klebsiella and termed pk181, into the microbial population of patients of the Orvieto Hospital was studied during 1982. Five hundred and seventy-four strains of Gram-negative bacilli were examined, transferable gentamicin resistance being revealed in five different bacterial species. The resistance was shown to be encoded by 81-megadalton plasmids in Escherichia coli and Enterobacter cloacae, and by 93-megadalton plasmids in Serratia marcescens and Pseudomonas spp. Restriction endonuclease digestion of plasmid DNA showed that the fragment patterns of the 81-megadalton plasmids from E. coli and enterobacter cloacae were identical to one another and to the pattern of plasmid pk181. The fragment patterns of the 93-megadalton plasmids from Serratia and Pseudomonas, on the contrary, differed substantially from those of the 81-megadalton plasmids.

DNA Restriction Enzymes↗