11 research outputs found
Synergistic effects of neurons and astrocytes on the differentiation of brain capillary endothelial cells in culture
Brain capillary endothelial cells form a functional barrier between blood and brain, based on the existence of tight junctions that limit paracellular permeability. Occludin is one of the major transmembrane proteins of tight junctions and its peripheral localization gives indication of tight junction formation. We previously reported that RBE4.B cells (brain capillary endothelial cells), cultured on collagen IV, synthesize occludin and correctly localize it at the cell periphery only when cocultured with neurons. In the present study, we describe a three-cell type-culture system that allowed us to analyze the combined effects of neurons and astrocytes on differentiation of brain capillary endothelial cells in culture. In particular, we found that, in the presence of astrocytes, the neuron-induced synthesis and localization of occludin is precocious as compared to cells cocultured with neurons only
Synthesis and characterisation of novel chemical conjugates based on alpha, beta-polyaspartylhydrazide and beta-cyclodextrins
A new family of supramolecular systems based on a synthetic polyaminoacid and cyclic oligosaccharides such as beta-cyclodextrins (beta-CDs) was synthesised. The pharmaceutical potential of these systems arises from the proper combination between the complexing properties of cyclodextrins and the particular pharmacokinetic profile that can be obtained by using macromolecular conjugates with a biocompatible backbone. Five supramolecular conjugates were synthesised by using alpha,beta-polyaspartylhydrazide (PAHy) as a polymeric component and various amounts of two P-CD derivatives. In particular, by reaction of PAHy with beta-CD monoaldehyde, samples named as A(1), A(2) and A(3), bearing, respectively, 4.0, 7.5 and 10.7 mol% of beta-CDs were obtained. The reaction of PAHy with 6-[aminoethyl(4'-carboxybutanamide)]-beta-CD afforded samples named as B-1 and B-2, bearing, respectively, 1.8 and 2.6 mol% of beta-CDs linked to the polymer. The occurrence of the conjugation reactions as well as the evaluation of the amount of oligosaccharides conjugated to the polymeric backbone were confirmed by FT-IR, H-1 NMR, DSC, SEC analyses and viscosimetric measurements. Molecular weight values obtained by SEC analysis were in good agreement with the theoretical increase of molecular weight of PAHy due to the beta-CD moieties linked to the polymeric backbone. Fluorescence studies on the conjugate A(3) evidenced an interaction of a probe molecule with beta-CDs linked to PAHy greater than that found with beta-CDs alone and even in both cases the formation of a 1:1 host-guest complex occurs
Coinfection of Helicobacter pylori and Epstein-Barr virus in patients with gastric disease in Southern Italy
Helicobacter pylor
MOLECULAR EPIDEMIOLOGY OF MYCOBACTERIUM TUBERCULOSIS COMPLEX IN PALERMO, ITALY
Background: We aimed to investigate the molecular
epidemiology of Mycobacterium tuberculosis
complex (MTBC) in the province of
Palermo, Italy, by characterizing 183 isolates
identified in the years 2004-2012. A comparison
with 104 MTBC strains identified in the
same geographic area in the years 1994-2000
was also carried out.
Methods: MTBC isolates were analyzed by
spoligotyping and the 24 mycobacterial interspersed
repetitive unit (MIRU)-variablenumber
tandem-repeat (VNTR) method typing.
Susceptibility testing to streptomycin,
isoniazid, rifampin and ethambutol was also
carried out. Furthermore, the spoligotyping
dataset obtained from 104 MTBC isolates identified
in the years 1994-2000 in the same geographic
area was reanalyzed. Distribution into
lineages and clustering of isolates in the two
periods was compared.
Results: Out of the 177 isolates of MTBC submitted
to molecular typing, 108 were from
Italian-born and 69 from foreign-born individuals.
Eleven different lineages were identified
with the most represented being Haarlem,
T, LAM and S. Except for the Haarlem lineage,
where isolates from foreign-born patients were
overrepresented, the distribution of isolates in
the families belonging to the Euro-American
phylogeographical clone reflected the proportions
of the two subpopulations. A total of 27
strains (15.2%) were clustered and three cluster
were mixed. 25% of the isolates proved to be
resistant to at least one anti-TB drug, with only three isolates being categorized as multidrug
resistant (MDR). When MTBC isolates identified
in the years 1994-2000 were reanalyzed,
lineages T, LAM, Haarlem and S proved also
to be predominant. No MTBC isolates belonging
to CAM, U, CAS, Turkish and Ural lineages
were identified in this set of isolates. Moreover,
the proportion of clustered isolates was similar,
but all the clustered isolates were from Italian
patients.
Conclusions: A wide heterogeneity (11 lineages
and 35 families-subfamilies) was detected
among the MTBC strains isolated in
the years 2004-2012. Ten clusters were identified,
of which three mixed and four involving
newly identified lineages. Compared with isolates
from 1994-2000, six new lineages were
detected. Comparison between distribution of
lineages and the characteristics of isolates in
the two consecutive periods depicts rapid and
deep changes in the tuberculosis epidemiology
in Palermo, Italy
Draft Genome Sequence and Biofilm Production of a Carbapenemase-Producing Klebsiella pneumoniae (KpR405) Sequence Type 405 Strain Isolated in Italy
Rapid identification and characterization of multidrug-resistant Klebsiella pneumoniae strains is essential to diagnose severe infections in patients. In clinical routine practice, K. pneumoniae is frequently identified and characterized for outbreak investigation. Pulsed-field gel electrophoresis or multilocus sequence typing could be used, but, unfortunately, these methods are time-consuming, laborious, expensive, and do not provide any information about the presence of resistance and virulence genes. In recent years, the decreasing cost of next-generation sequencing and its easy use have led to it being considered a useful method, not only for outbreak surveillance but also for rapid identification and evaluation, in a single step, of virulence factors and resistance genes. Carbapenem-resistant strains of K. pneumoniae have become endemic in Italy, and in these strains the ability to form biofilms, communities of bacteria fixed in an extracellular matrix, can defend the pathogen from the host immune response as well as from antibiotics, improving its persistence in epithelial tissues and on medical device surfaces