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Biomedical subjects

M A Bianchi

Publications and source records attributed to M A Bianchi.

At least 19 recordsLinked to original sources

A fluorescence-based method for the detection of adhesive properties of lactic acid bacteria to Caco-2 cells.

AIMS: The ability of probiotic micro-organisms to adhere to the intestinal surface is regarded as a substantial advantage in terms of bacteria persistence in the gastrointestinal tract. The aim of the present study was the development of a method based on fluorescent staining of bacteria and subsequent spectrofluorimetric detection to quantify the adhesion of several strains of Lactobacillus and Bifidobacterium to Caco-2 cells. METHODS AND RESULTS: Lactic acid bacteria strains were subjected to fluorescent staining using the viable probe carboxyfluorescein diacetate and subsequently incubated on Caco-2 monolayers. The adhesion of the micro-organisms was determined by spectrofluorimetry following the lysis of the attached bacterial cells and expressed as adhesion percentage. The values obtained for the micro-organisms tested ranged from 4% for Bifidobacterium infantis Bi1 to 10% for a Bifidobacterium mixture containing three different strains. CONCLUSIONS: In the present study we successfully applied fluorescent labelling and fluorimetric detection to investigate the adhesive properties of some Lactobacillus and Bifidobacterium strains and a Bifidobacterium mixture to Caco-2 cells. SIGNIFICANCE AND IMPACT OF THE STUDY: The results proved that fluorescent labelling is suitable for adhesion studies and provides a reliable and safer alternative to radioactive labelling.

Bacterial Adhesion↗

Treatment of toxic epidermal necrolysis and Stevens-Johnson syndrome in children.

A retrospective study was carried out on eight consecutively treated children, 2 to 14 years of age, seven with toxic epidermal necrolysis and one with transitional-type Stevens-Johnson syndrome. The body surfaces affected ranged from 40% to 100%. Seven of the patients were taking a sulfonamide or anticonvulsant before the onset of their disease. Complete reepithelialization took an average of 15 days, but newly evolving lesions of the lips and oropharynx continued for approximately 4 more weeks. These lesions took an additional 2 to 4 weeks to heal. Only one of the children died.

Adolescent↗

Spin-lattice relaxation rates in Fe(III)-doped human serum measured by magnetic resonance imaging.

The proton spin-lattice relaxation time T1 in iron-doped serum was measured with a magnetic resonance imager operating at 0.5 T. The T1 in aqueous solutions of iron and iron-doped solutions of albumin and gamma globulin was also measured in order to analyse the paramagnetic contribution in iron-doped serum. The enhancement in serum is not linearly dependent on concentration of iron added. It is known that Fe(III) added to serum is mainly complexed with transferrin, albumin, gamma globulin and water. With serum pH (7.9) Fe(III) in the protein solution results in enhancement. Fe(III) in water does not cause any enhancement. As a result, the 1/T1 enhancement in serum should be caused solely by iron-binding serum proteins.

Blood↗

[Comparison between serum ferritin and induced sideruria in the diagnosis of disorders of iron metabolism].

The A. compare the values of serum ferritin and Desferrioxamine (DFO)-induced sideruria on 73 patients affected by different diseases. The results may be divided into three groups: a first one concerning patients with low serum ferritin and low DFO-induced sideruria, a second one of patients with normal serum ferritin and normal DFO-induced sideruria; in the third group of patients the A. found high values of serum ferritin and high or normal values of DFO-induced sideruria. The different behaviour observed in this III group of patients mostly affected by malignancy may be ascribed, in all those cases with high ferritin and normal sideruria, to a direct production of isoferritins by cancer cells.

Adult↗

[Planktonic and bacterial population dynamics during experimental production of natural marine phytoplankton. II. Structure and physiology of populations and their interactions].

During the spring, an experiment was conducted on the production of natural phytoplankton in a continuous flow layout of large capacity, and an analysis was made of the simultaneous evolution of microplanktonic populations (taxonomic composition, diversity, class ranges, and energetic charge) and of bacterial populations (structure, diversity, dominances, and cetabolic potentialities). Oligotrophic initial conditions were charcterized by a poor (0.22 umg of chlorphyll a/L) and diversified (pigment diversity = 4.5) phytoplankton with nanoplanktonic dominance associated with several benthic type diatoms. Bacterial flora, in which pseudomonads were dominant (54.5%), were also diversified (Shannon index H = 3.57). Metabolic potentialities of these bacterial communities were several. Enrichment of the milieu caused the selection and development of a small number of algal species dominated by the diatoms skeletonema costatum (64 x 106/L) and Chaetoceros (3.2 x 106/L) leading to a paucispecific population with a large biomass, a pigment diversity of 1.97, and a chlorophyll a concentration of 25.08 mu/L. The bacterial community then because diversified (H = 4.12) and, although pseudomonads remained dominant (62%), a larger use of organic micromolecules was noted. The establishment of this phytoplanktonic community was followed by a zooplanktonic development in which larger species succeeded smaller ones (ciliates, tintinnides, rotifers, and copepods) corresponding to the global increase of the phytobiomass. Although this system appeared to be in a phase of relative stability, a decease in the energetic charge showed a disturbance in the physiological state of the planktonic populations. These phenomena led to the vanishing of the diatom's dominance (Chaetoceros, and then S. costatum) and its replacement by nanoplankton (123 x 106 cells/L) and dinoflagellates (300000 cells/L). A modification in the organic wealth of the milieu with the addition of particular complex material that was not or little degraded caused deep disturbances in the bacterial populations. Their diversity reached a very low level (H = 1.56 to 2.25) with a proliferation of vibrions (up to 74%) well equipped with exoenzymes, but more restricted in their nutritional versatility (marked preference for organic macromolecules). During the final phase of experimentation, despite a change in qualitative composition and a more important biomass, microplanktonic and bacterial populations returned to a diversified state nearing that of the initial conditions (pigment diversity = 3.2; H = 3.37).

Adenosine Triphosphate↗

[Deoxyribonucleic acid hybridizations among some vibrio-like marine bacteria (author's transl)].

The genotypic relationships established by DNA/DNA hybridization in vitro confirm the results obtained by earlier phenotypic analyses of certain vibrio-like marine bacteria. These strains are closely related to the species Photobacterium fischeri, and do not belong to the genus Vibrio. The group of marine, vibrio-like bacteria that require Na+ for growth is genotypically very heterogeneous.

DNA, Bacterial↗